Dysregulation of synaptic plasticity precedes appearance of morphological defects in a Pten conditional knockout mouse model of autism.

PubMed

Takeuchi, Koichi; Gertner, Michael J; Zhou, Jing; Parada, Luis F; Bennett, Michael V L; Zukin, R Suzanne

2013-03-19

The phosphoinositide signaling system is a crucial regulator of neural development, cell survival, and plasticity. Phosphatase and tensin homolog deleted on chromosome 10 (PTEN) negatively regulates phosphatidylinositol 3-kinase signaling and downstream targets. Nse-Cre Pten conditional knockout mice, in which Pten is ablated in granule cells of the dentate gyrus and pyramidal neurons of the hippocampal CA3, but not CA1, recapitulate many of the symptoms of humans with inactivating PTEN mutations, including progressive hypertrophy of the dentate gyrus and deficits in hippocampus-based social and cognitive behaviors. However, the impact of Pten loss on activity-dependent synaptic plasticity in this clinically relevant mouse model of Pten inactivation remains unclear. Here, we show that two phosphatidylinositol 3-kinase- and protein synthesis-dependent forms of synaptic plasticity, theta burst-induced long-term potentiation and metabotropic glutamate receptor (mGluR)-dependent long-term depression, are dysregulated at medial perforant path-to-dentate gyrus synapses of young Nse-Cre Pten conditional knockout mice before the onset of visible morphological abnormalities. In contrast, long-term potentiation and mGluR-dependent long-term depression are normal at CA3-CA1 pyramidal cell synapses at this age. Our results reveal that deletion of Pten in dentate granule cells dysregulates synaptic plasticity, a defect that may underlie abnormal social and cognitive behaviors observed in humans with Pten inactivating mutations and potentially other autism spectrum disorders.

Effects of inhaled anesthetic isoflurane on long-term potentiation of CA3 pyramidal cell afferents in vivo

PubMed Central

Ballesteros, Kristen A; Sikorski, Angela; Orfila, James E; Martinez, Joe L

2012-01-01

Isoflurane is a preferred anesthetic, due to its properties that allow a precise concentration to be delivered continually during in vivo experimentation. The major mechanism of action of isoflurane is modulation of the γ-amino butyric acid (GABAA) receptor-chloride channel, mediating inhibitory synaptic transmission. Animal studies have shown that isoflurane does not cause cell death, but it does inhibit cell growth and causes long-term hippocampal learning deficits. As there are no studies characterizing the effects of isoflurane on electrophysiological aspects of long-term potentiation (LTP) in the hippocampus, it is important to determine whether isoflurane alters the characteristic responses of hippocampal afferents to cornu ammonis region 3 (CA3). We investigated the effects of isoflurane on adult male rats during in vivo induction of LTP, using the mossy fiber pathway, the lateral perforant pathway, the medial perforant pathway, and the commissural CA3 (cCA3) to CA3, with intracranial administration of Ringer’s solution, naloxone, RS-aminoindan-1, 5-dicarboxylic acid (AIDA), or 3-[(R)-2-carboxypiperazin-4-yl]-propo-2-enyl-1-phosphonic acid (CPP). Then, we compared these responses to published electrophysiological data, using sodium pentobarbital as an anesthetic, under similar experimental conditions. Our results showed that LTP was exhibited in animals anesthetized with isoflurane under vehicle conditions. With the exception of AIDA in the lateral perforant pathway, the defining characteristics of the four pathways appeared to remain intact, except for the observation that LTP was markedly reduced in animals anesthetized with isoflurane compared to those anesthetized with sodium pentobarbital. The results suggest that isoflurane may affect amplitude through activation of GABAA receptors or mechanisms important to LTP in CA3 afferent fibers. PMID:23204857

Facilitation of granule cell epileptiform activity by mossy fiber-released zinc in the pilocarpine model of temporal lobe epilepsy.

PubMed

Timofeeva, Olga; Nadler, J Victor

2006-03-17

Recurrent mossy fiber synapses in the dentate gyrus of epileptic brain facilitate the synchronous firing of granule cells and may promote seizure propagation. Mossy fiber terminals contain and release zinc. Released zinc inhibits the activation of NMDA receptors and may therefore oppose the development of granule cell epileptiform activity. Hippocampal slices from rats that had experienced pilocarpine-induced status epilepticus and developed a recurrent mossy fiber pathway were used to investigate this possibility. Actions of released zinc were inferred from the effects of chelation with 1 mM calcium disodium EDTA (CaEDTA). When granule cell population bursts were evoked by mossy fiber stimulation in the presence of 6 mM K(+) and 30 microM bicuculline, CaEDTA slowed the rate at which evoked bursting developed, but did not change the magnitude of the bursts once they had developed fully. The effects of CaEDTA were then studied on the pharmacologically isolated NMDA receptor- and AMPA/kainate receptor-mediated components of the fully developed bursts. CaEDTA increased the magnitude of NMDA receptor-mediated bursts and reduced the magnitude of AMPA/kainate receptor-mediated bursts. CaEDTA did not affect the granule cell bursts evoked in slices from untreated rats by stimulating the perforant path in the presence of bicuculline and 6 mM K(+). These results suggest that zinc released from the recurrent mossy fibers serves mainly to facilitate the recruitment of dentate granule cells into population bursts.

Long-term potentiation expands information content of hippocampal dentate gyrus synapses.

PubMed

Bromer, Cailey; Bartol, Thomas M; Bowden, Jared B; Hubbard, Dusten D; Hanka, Dakota C; Gonzalez, Paola V; Kuwajima, Masaaki; Mendenhall, John M; Parker, Patrick H; Abraham, Wickliffe C; Sejnowski, Terrence J; Harris, Kristen M

2018-03-06

An approach combining signal detection theory and precise 3D reconstructions from serial section electron microscopy (3DEM) was used to investigate synaptic plasticity and information storage capacity at medial perforant path synapses in adult hippocampal dentate gyrus in vivo. Induction of long-term potentiation (LTP) markedly increased the frequencies of both small and large spines measured 30 minutes later. This bidirectional expansion resulted in heterosynaptic counterbalancing of total synaptic area per unit length of granule cell dendrite. Control hemispheres exhibited 6.5 distinct spine sizes for 2.7 bits of storage capacity while LTP resulted in 12.9 distinct spine sizes (3.7 bits). In contrast, control hippocampal CA1 synapses exhibited 4.7 bits with much greater synaptic precision than either control or potentiated dentate gyrus synapses. Thus, synaptic plasticity altered total capacity, yet hippocampal subregions differed dramatically in their synaptic information storage capacity, reflecting their diverse functions and activation histories.

Fluxes of Ca2+ and K+ are required for the listeriolysin O-dependent internalization pathway of Listeria monocytogenes.

PubMed

Vadia, Stephen; Seveau, Stephanie

2014-03-01

Listeria monocytogenes is responsible for the life-threatening food-borne disease listeriosis. This disease mainly affects elderly and immunocompromised individuals, causing bacteremia and meningoencephalitis. In pregnant women, L. monocytogenes infection leads to abortion and severe infection of the fetus or newborn. The L. monocytogenes intracellular life cycle is critical for pathogenesis. Previous studies have established that the major virulence factor of L. monocytogenes, the pore-forming toxin listeriolysin O (LLO), is sufficient to induce L. monocytogenes internalization into human epithelial cell lines. This internalization pathway strictly requires the formation of LLO pores in the plasma membrane and can be stimulated by the heterologous pore-forming toxin pneumolysin, suggesting that LLO acts nonspecifically by forming transmembrane pores. The present work tested the hypothesis that Ca2+ and K+ fluxes subsequent to perforation by LLO control L. monocytogenes internalization. We report that L. monocytogenes perforates the host cell plasma membrane in an LLO-dependent fashion at the early stage of invasion. In response to perforation, host cells undergo Ca2+ -dependent but K+ -independent resealing of their plasma membrane. In contrast to the plasma membrane resealing process, LLO-induced L. monocytogenes internalization requires both Ca2+ and K+ fluxes. Further linking ion fluxes to bacterial internalization, treating cells with a combination of Ca2+ and K+ ionophores but not with individual ionophores is sufficient to induce efficient internalization of large cargoes, such as 1-μm polystyrene beads and bacteria. We propose that LLO-induced L. monocytogenes internalization requires a Ca2+ - and K+ -dependent internalization pathway that is mechanistically distinct from the process of plasma membrane resealing.

Effects of intrahippocampal aniracetam treatment on Y-maze avoidance learning performance and behavioral long-term potentiation in dentate gyrus in rat.

PubMed

Rao, Y; Xiao, P; Xu, S

2001-02-09

Effects of intrahippocampal treatment of aniracetam, a selective agonist for DL-alpha-amino-3-hydroxy-5-methyl-4-isoxazoleproionic acid (AMPA) receptors, on Y-maze avoidance learning task and behavioral long-term potentiation (LTP) in perforant path-dentate gyrus were studied in freely moving rats by using in vivo electrophysiology combined with behavioral tests. The results were as follows: (1) intrahippocampal treatment of aniracetam reversibly enhanced basal synaptic transmission in perforant path to dentate gyrus in a dosage dependent manner; (2) aniracetam produced improvement in Y-maze learning performance when administration occurred 5 min prior to maze learning; (3) aniracetam administration significantly facilitated behavioral LTP in dentate gyrus, while the maximal amplitude of LTP has no significant difference when compared to saline group. The present results indicate that hippocampal AMPA receptors are involved in learning and memory.

Lesion-induced plasticity of high affinity choline uptake in the developing rat fascia dentata.

PubMed

Nadler, J V; Shelton, D L; Cotman, C W

1979-03-23

After removal of the perforant path input to the rat fascia dentata at the age of 11 days, cholinergic septohippocampal fibers invade the denervated area. We have examined the effect of this lesion on hemicholinium-sensitive, high affinity choline uptake and its coupling to acetylcholine synthesis, specific properties of the septohippocampal input. Removal of the ipsilateral perforant path fibers increased the velocity of high affinity choline uptake by dentate particulate preparations, usually within 1 day. Studies conducted 5--104 days after operation showed a consistent 50--65% elevation in the molecular (denervated) layer. In contrast, the choline uptake rate in the granular layer eventually decreased slightly. Calculation of choline uptake rates independently of protein (per whole region) revealed that fasciae dentatae from operated and control sides accumulated choline at approximately equal rates, but on the operated side a greater percentage was transported by structures from the molecular layer and a lesser percentage by those from the granular layer. The rate of acetylcholine synthesis from exogenous choline increased to the same extent as high affinity choline uptake from 3 days after operation onwards. The changes in high affinity choline uptake and acetylcholine synthesis coincided spatially and temporally with the reactive growth of septohippocampal fibers. Our results support the view that a perforant path lesion during development permanently alters the distribution of functional septohippocampal boutons in the fascia dentata. Acetylcholine synthesis is regulated to the same extent by high affinity choline uptake in the anomalous boutons as in normally located boutons.

Preserved number of entorhinal cortex layer II neurons in aged macaque monkeys

NASA Technical Reports Server (NTRS)

Gazzaley, A. H.; Thakker, M. M.; Hof, P. R.; Morrison, J. H.; Bloom, F. E. (Principal Investigator)

1997-01-01

The perforant path, which consists of the projection from the layer II neurons of the entorhinal cortex to the outer molecular layer of the dentate gyrus, is a critical circuit involved in learning and memory formation. Accordingly, disturbances in this circuit may contribute to age-related cognitive deficits. In a previous study, we demonstrated a decrease in N-methyl-D-aspartate receptor subunit 1 immunofluorescence intensity in the outer molecular layer of aged macaque monkeys. In this study, we used the optical fractionator, a stereological method, to determine if a loss of layer II neurons occurred in the same animals in which the N-methyl-D-aspartate receptor subunit 1 alteration was observed. Our results revealed no significant differences in the number of layer II neurons between juvenile, young adult, and aged macaque monkeys. These results suggest that the circuit-specific decrease in N-methyl-D-aspartate receptor subunit 1 reported previously occurs in the absence of structural compromise of the perforant path, and thus may be linked to an age-related change in the physiological properties of this circuit.

A quantitative theory of the functions of the hippocampal CA3 network in memory

PubMed Central

Rolls, Edmund T.

2013-01-01

A quantitative computational theory of the operation of the hippocampal CA3 system as an autoassociation or attractor network used in episodic memory system is described. In this theory, the CA3 system operates as a single attractor or autoassociation network to enable rapid, one-trial, associations between any spatial location (place in rodents, or spatial view in primates) and an object or reward, and to provide for completion of the whole memory during recall from any part. The theory is extended to associations between time and object or reward to implement temporal order memory, also important in episodic memory. The dentate gyrus (DG) performs pattern separation by competitive learning to produce sparse representations suitable for setting up new representations in CA3 during learning, producing for example neurons with place-like fields from entorhinal cortex grid cells. The dentate granule cells produce by the very small number of mossy fiber (MF) connections to CA3 a randomizing pattern separation effect important during learning but not recall that separates out the patterns represented by CA3 firing to be very different from each other, which is optimal for an unstructured episodic memory system in which each memory must be kept distinct from other memories. The direct perforant path (pp) input to CA3 is quantitatively appropriate to provide the cue for recall in CA3, but not for learning. Tests of the theory including hippocampal subregion analyses and hippocampal NMDA receptor knockouts are described, and support the theory. PMID:23805074

A role for N-methyl-D-aspartate receptors in norepinephrine-induced long-lasting potentiation in the dentate gyrus.

PubMed

Stanton, P K; Mody, I; Heinemann, U

1989-01-01

Mechanisms of action of norepinephrine (NE) on dentate gyrus granule cells were studied in rat hippocampal slices using extra- and intracellular recordings and measurements of stimulus and amino acid-induced changes in extracellular Ca2+ and K+ concentration. Bath application of NE (10-50 microM) induced long-lasting potentiation of perforant path evoked potentials, and markedly enhanced high-frequency stimulus-induced Ca2+ influx and K+ efflux, actions blocked by beta-receptor antagonists and mimicked by beta agonists. Enhanced Ca2+ influx was primarily postsynaptic, since presynaptic delta [Ca2+]o in the stratum moleculare synaptic field was not altered by NE. Interestingly, the potentiation of both ionic fluxes and evoked population potentials were antagonized by the N-methyl-D-aspartate (NMDA) receptor antagonist 2-amino-5-phosphonovalerate (APV). Furthermore, NE selectively enhanced the delta [Ca2+]o delta [K+]o and extracellular slow negative field potentials elicited by iontophoretically applied NMDA, but not those induced by the excitatory amino acid quisqualate. These results suggest that granule cell influx of Ca2+ through NMDA ionophores is enhanced by NE via beta-receptor activation. In intracellular recordings, NE depolarized granule cells (4.8 +/- 1.1 mV), and increased input resistance (RN) by 34 +/- 6.5%. These actions were also blocked by either the beta-antagonist propranolol or specific beta 1-blocker metoprolol. Moreover, the depolarization and RN increase persisted for long periods (93 +/- 12 min) after NE washout. In contrast, while NE, in the presence of APV, still depolarized granule cells and increased RN, APV made these actions quickly reversible upon NE washout (16 +/- 9 min). This suggested that NE induction of long-term, but not short-term, plasticity in the dentate gyrus requires NMDA receptor activation. NE may be enhancing granule cell firing by some combination of blockade on the late Ca2+-activated K+ conductance and depolarization of granule cells, both actions that can bring granule cells into a voltage range where NMDA receptors are more easily activated. Furthermore, NE also elicited activity-independent long-lasting depolarization and RN increases, which required functional NMDA receptors to persist.

ANTICONVULSANT AND ANTIEPILEPTIC ACTIONS OF 2-DEOXY-DGLUCOSE IN EPILEPSY MODELS

PubMed Central

Stafstrom, Carl E.; Ockuly, Jeffrey C.; Murphree, Lauren; Valley, Matthew T.; Roopra, Avtar; Sutula, Thomas P.

2009-01-01

Objective Conventional anticonvulsants reduce neuronal excitability through effects on ion channels and synaptic function. Anticonvulsant mechanisms of the ketogenic diet remain incompletely understood. Since carbohydrates are restricted in patients on the ketogenic diet, we evaluated the effects of limiting carbohydrate availability by reducing glycolysis using the glycolytic inhibitor 2-deoxy-D-glucose (2DG) in experimental models of seizures and epilepsy. Methods Acute anticonvulsant actions of 2DG were assessed in vitro in rat hippocampal slices perfused with 7.5mM [K+]o, 4-aminopyridine (4-AP), or bicuculline and in vivo against seizures evoked by 6 Hz stimulation in mice, audiogenic stimulation in Fring’s mice, and maximal electroshock and subcutaneous Metrazol in rats. Chronic antiepileptic effects of 2DG were evaluated in rats kindled from olfactory bulb or perforant path. Results 2DG (10mM) reduced interictal epileptiform bursts induced by high [K+]o, 4-AP and bicuculline, and electrographic seizures induced by high [K+]o in CA3 of hippocampus. 2DG reduced seizures evoked by 6 Hz stimulation in mice (ED50 = 79.7 mg/kg) and audiogenic stimulation in Fring’s mice (ED50 = 206.4 mg/kg). 2DG exerted chronic antiepileptic action by increasing afterdischarge thresholds in perforant path (but not olfactory bulb) kindling and caused a 2-fold slowing in progression of kindled seizures at both stimulation sites. 2DG did not protect against maximal electroshock or Metrazol seizures. Interpretation The glycolytic inhibitor 2DG exerts acute anticonvulsant and chronic antiepileptic actions and has a novel pattern of effectiveness in preclinical screening models. These results identify metabolic regulation as a potential therapeutic target for seizure suppression and modification of epileptogenesis. PMID:19399874

A distinct entorhinal cortex to hippocampal CA1 direct circuit for olfactory associative learning.

PubMed

Li, Yiding; Xu, Jiamin; Liu, Yafeng; Zhu, Jia; Liu, Nan; Zeng, Wenbo; Huang, Ning; Rasch, Malte J; Jiang, Haifei; Gu, Xiang; Li, Xiang; Luo, Minhua; Li, Chengyu; Teng, Junlin; Chen, Jianguo; Zeng, Shaoqun; Lin, Longnian; Zhang, Xiaohui

2017-04-01

Lateral and medial parts of entorhinal cortex (EC) convey nonspatial 'what' and spatial 'where' information, respectively, into hippocampal CA1, via both the indirect EC layer 2→ hippocampal dentate gyrus→CA3→CA1 and the direct EC layer 3→CA1 paths. However, it remains elusive how the direct path transfers distinct information and contributes to hippocampal learning functions. Here we report that lateral EC projection neurons selectively form direct excitatory synapses onto a subpopulation of morphologically complex, calbindin-expressing pyramidal cells (PCs) in the dorsal CA1 (dCA1), while medial EC neurons uniformly innervate all dCA1 PCs. Optogenetically inactivating the distinct lateral EC-dCA1 connections or the postsynaptic dCA1 calbindin-expressing PC activity slows olfactory associative learning. Moreover, optetrode recordings reveal that dCA1 calbindin-expressing PCs develop more selective spiking responses to odor cues during learning. Thus, our results identify a direct lateral EC→dCA1 circuit that is required for olfactory associative learning.

Identification of the kainate receptor subunits underlying modulation of excitatory synaptic transmission in the CA3 region of the hippocampus.

PubMed

Contractor, A; Swanson, G T; Sailer, A; O'Gorman, S; Heinemann, S F

2000-11-15

To understand the physiological role of kainate receptors and their participation in seizure induction in animal models of epilepsy, it will be necessary to develop a comprehensive description of their action in the CA3 region of the hippocampus. Activation of presynaptic kainate receptors depresses excitatory synaptic transmission at mossy fiber and associational-commissural inputs to CA3 pyramidal neurons (Vignes et al., 1998; Bortolotto et al., 1999; Kamiya and Ozawa, 2000). In this study, we use gene-targeted mice lacking glutamate receptor 5 (GluR5) or GluR6 kainate receptor subunits to identify the receptor subunits that comprise the kainate receptors responsible for presynaptic modulation of CA3 transmission. We found that bath application of kainate (3 microm) profoundly reduced EPSCs at mossy fiber and collateral synapses in neurons from wild-type and GluR5(-/-) mice but had no effect on EPSCs in neurons from GluR6(-/-) mice. These results therefore contrast with previous studies that supported a role for GluR5-containing receptors at mossy fiber and associational-commissural synapses (Vignes et al., 1998; Bortolotto et al., 1999). Surprisingly, at perforant path synapses kainate receptor activation enhanced transmission; this potentiation was abolished in both GluR5 and GluR6 knock-out mice. Kainate receptors thus play multiple and complex roles to modulate excitatory synaptic transmission in the CA3 region of the hippocampus.

THE 4-AMINOPYRIDINE IN VITRO EPILEPSY MODEL ANALYZED WITH A PERFORATED MULTI-ELECTRODE ARRAY

PubMed Central

Gonzalez-Sulser, Alfredo; Wang, Jing; Motamedi, Gholam K.; Avoli, Massimo; Vicini, Stefano; Dzakpasu, Rhonda

2010-01-01

Epileptiform discharges recorded in the 4-aminopyridine (4-AP) in vitro epilepsy model are mediated by glutamatergic and GABAergic signaling. Using a 60-channel perforated multi-electrode array (pMEA) on corticohippocampal slices from 2 to 3 week old mice we recorded interictal- and ictal-like events. When glutamatergic transmission was blocked, interictal-like events events no longer initiated in the hilus or CA3/CA1 pyramidal layers but originated from the dentate gyrus granule and molecular layers. Furthermore, frequencies of interictal-like events were reduced and durations were increased in these regions while cortical discharges were completely blocked. Following GABAA receptor blockade interictal-like events no longer propagated to the dentate gyrus while their frequency in CA3 increased; in addition, ictal-like cortical events became shorter while increasing in frequency. Lastly, drugs that affect tonic and synaptic GABAergic conductance modulate the frequency, duration, initiation and propagation of interictal-like events. These findings confirm and expand on previous studies indicating that multiple synaptic mechanisms contribute to synchronize neuronal network activity in forebrain structures. PMID:20955719

Pseudo-random tool paths for CNC sub-aperture polishing and other applications.

PubMed

Dunn, Christina R; Walker, David D

2008-11-10

In this paper we first contrast classical and CNC polishing techniques in regard to the repetitiveness of the machine motions. We then present a pseudo-random tool path for use with CNC sub-aperture polishing techniques and report polishing results from equivalent random and raster tool-paths. The random tool-path used - the unicursal random tool-path - employs a random seed to generate a pattern which never crosses itself. Because of this property, this tool-path is directly compatible with dwell time maps for corrective polishing. The tool-path can be used to polish any continuous area of any boundary shape, including surfaces with interior perforations.

Complex role of STIM1 in the activation of store-independent Orai1/3 channels

PubMed Central

Zhang, Wei; González-Cobos, José C.; Jardin, Isaac; Romanin, Christoph; Matrougui, Khalid

2014-01-01

Orai proteins contribute to Ca2+ entry into cells through both store-dependent, Ca2+ release–activated Ca2+ (CRAC) channels (Orai1) and store-independent, arachidonic acid (AA)-regulated Ca2+ (ARC) and leukotriene C4 (LTC4)-regulated Ca2+ (LRC) channels (Orai1/3 heteromultimers). Although activated by fundamentally different mechanisms, CRAC channels, like ARC and LRC channels, require stromal interacting molecule 1 (STIM1). The role of endoplasmic reticulum–resident STIM1 (ER-STIM1) in CRAC channel activation is widely accepted. Although ER-STIM1 is necessary and sufficient for LRC channel activation in vascular smooth muscle cells (VSMCs), the minor pool of STIM1 located at the plasma membrane (PM-STIM1) is necessary for ARC channel activation in HEK293 cells. To determine whether ARC and LRC conductances are mediated by the same or different populations of STIM1, Orai1, and Orai3 proteins, we used whole-cell and perforated patch-clamp recording to compare AA- and LTC4-activated currents in VSMCs and HEK293 cells. We found that both cell types show indistinguishable nonadditive LTC4- and AA-activated currents that require both Orai1 and Orai3, suggesting that both conductances are mediated by the same channel. Experiments using a nonmetabolizable form of AA or an inhibitor of 5-lipooxygenase suggested that ARC and LRC currents in both cell types could be activated by either LTC4 or AA, with LTC4 being more potent. Although PM-STIM1 was required for current activation by LTC4 and AA under whole-cell patch-clamp recordings in both cell types, ER-STIM1 was sufficient with perforated patch recordings. These results demonstrate that ARC and LRC currents are mediated by the same cellular populations of STIM1, Orai1, and Orai3, and suggest a complex role for both ER-STIM1 and PM-STIM1 in regulating these store-independent Orai1/3 channels. PMID:24567509

The antiepileptogenic effect of low-frequency stimulation on perforant path kindling involves changes in regulators of G-protein signaling in rat.

PubMed

Namvar, Simin; Fathollahi, Yaghoub; Javan, Mohammad; Zeraati, Maryam; Mohammad-Zadeh, Mohammad; Shojaei, Amir; Mirnajafi-Zadeh, Javad

2017-04-15

G-protein coupled receptors may have a role in mediating the antiepileptogenic effect of low-frequency stimulation (LFS) on kindling acquisition. This effect is accompanied by changes at the intracellular level of cAMP. In the present study, the effect of rolipram as a phosphodiesterase inhibitor on the antiepileptogenic effect of LFS was investigated. Meanwhile, the expression of α s - and α i -subunit of G proteins and regulators of G-protein signaling (RGS) proteins following LFS application was measured. Male Wistar rats were kindled by perforant path stimulation in a semi-rapid kindling manner (12 stimulations per day) during a period of 6days. Application of LFS (0.1ms pulse duration at 1Hz, 200 pulses, 50-150μA, 5min after termination of daily kindling stimulations) to the perforant path retarded the kindling development and prevented the kindling-induced potentiation and kindling-induced changes in paired pulse indices in the dentate gyrus. Intra-cerebroventricular microinjection of rolipram (0.25μM) partially prevented these LFS effects. Twenty-four hours after the last kindling stimulation, the dentate gyrus was removed and changes in protein expression were measured by Western blotting. There was no significant difference in the expression of α-subunit of G s and G i/o proteins in different experimental groups. However, application of LFS during the kindling procedure decreased the expression RGS4 and RGS10 proteins (that reduce the activity of G i/o ) and prevented the kindling-induced decrease of RGS2 protein (which reduces the G s activity). Therefore, it can be postulated that the G i/o protein signaling pathways may be involved in antiepileptogenetic effect of LFS, and this is why decreasing the cAMP metabolism by rolipram attenuates this effect of LFS. Copyright © 2017 Elsevier B.V. All rights reserved.

Heterosynaptic metaplasticity in the hippocampus in vivo: A BCM-like modifiable threshold for LTP

PubMed Central

Abraham, Wickliffe C.; Mason-Parker, Sara E.; Bear, Mark F.; Webb, Sarah; Tate, Warren P.

2001-01-01

The homeostatic maintenance of the “modification threshold” for inducing long-term potentiation (LTP) is a fundamental feature of the Bienenstock, Cooper, and Munro (BCM) model of synaptic plasticity. In the present study, two key features of the modification threshold, its heterosynaptic expression and its regulation by postsynaptic neural activity, were tested experimentally in the dentate gyrus of awake, freely moving rats. Conditioning stimulation ranging from 10 to 1,440 brief 400-Hz trains, when applied to medial perforant path afferents, raised the threshold for LTP induction heterosynaptically in the neighboring lateral perforant path synapses. This effect recovered slowly over a 7- to 35-day period. The same conditioning paradigms, however, did not affect the reversal of long-term depression. The inhibition of LTP by medial-path conditioning stimulation was N-methyl-D-aspartate (NMDA) receptor-dependent, but antidromic stimulation of the granule cells could also inhibit lateral path LTP induction, independently of NMDA receptor activation. Increased calcium buffering is a potential mechanism underlying the altered LTP threshold, but the levels of two important calcium-binding proteins did not increase after conditioning stimulation, nor was de novo protein synthesis required for generating the threshold shift. These data confirm, in an in vivo model, two key postulates of the BCM model regarding the LTP threshold. They also provide further evidence for the broad sensitivity of synaptic plasticity mechanisms to the history of prior activity, i.e., metaplasticity. PMID:11517323

The actions of volatile anaesthetics on synaptic transmission in the dentate gyrus.

PubMed Central

Richards, C D; White, A E

1975-01-01

1. The action of four volatile anaesthetics on the evoked synaptic potentials of in vitro preparations of the hippocampus were examined. 2. All four anaesthetics (ether, halothane, methoxyflurane and trichloroethylene) depressed the synaptic transmission between the perforant path and the granule cells at concentrations lower than those required to maintain anaesthesia in intact animals. 3. The population excitatory post-synaptic potential (e.p.s.p.) and massed discharge of the cortical cells (population spike) were depressed at concentrations of the anaesthetics lower than those required to depress the compound action potential of the perforant path nerve fibres. None of the anaesthetics studied increased the threshold depolarization required for granule cell discharge. Furthermore, frequency potentiation of the evoked cortical e.p.s.p.s was not impaired by any of the anaesthetics studied. 4. It is concluded that all four anaesthetics depress synaptic transmission in the dentate gyrus either by reducing the amount of transmitter released from each nerve terminal in response to an afferent volley, or by decreasing the sensitivity of the post-synaptic membrane to released transmitted or by both effects together. PMID:1202196

Lysosomes shape Ins(1,4,5)P3-evoked Ca2+ signals by selectively sequestering Ca2+ released from the endoplasmic reticulum

PubMed Central

López-Sanjurjo, Cristina I.; Tovey, Stephen C.; Prole, David L.; Taylor, Colin W.

2013-01-01

Summary Most intracellular Ca2+ signals result from opening of Ca2+ channels in the plasma membrane or endoplasmic reticulum (ER), and they are reversed by active transport across these membranes or by shuttling Ca2+ into mitochondria. Ca2+ channels in lysosomes contribute to endo-lysosomal trafficking and Ca2+ signalling, but the role of lysosomal Ca2+ uptake in Ca2+ signalling is unexplored. Inhibition of lysosomal Ca2+ uptake by dissipating the H+ gradient (using bafilomycin A1), perforating lysosomal membranes (using glycyl-L-phenylalanine 2-naphthylamide) or lysosome fusion (using vacuolin) increased the Ca2+ signals evoked by receptors that stimulate inositol 1,4,5-trisphosphate [Ins(1,4,5)P3] formation. Bafilomycin A1 amplified the Ca2+ signals evoked by photolysis of caged Ins(1,4,5)P3 or by inhibition of ER Ca2+ pumps, and it slowed recovery from them. Ca2+ signals evoked by store-operated Ca2+ entry were unaffected by bafilomycin A1. Video-imaging with total internal reflection fluorescence microscopy revealed that lysosomes were motile and remained intimately associated with the ER. Close association of lysosomes with the ER allows them selectively to accumulate Ca2+ released by Ins(1,4,5)P3 receptors. PMID:23097044

Unitary IPSPs evoked by interneurons at the stratum radiatum-stratum lacunosum-moleculare border in the CA1 area of the rat hippocampus in vitro

PubMed Central

Vida, Imre; Halasy, Katalin; Szinyei, Csaba; Somogyi, Peter; Buhl, Eberhard H

1998-01-01

Hippocampal non-principal neurons at the stratum radiatum-stratum lacunosum-moleculare border (R-LM interneurons) of the CA1 area may constitute several cell classes and have been implicated in the generation of GABAergic unitary IPSPs. Using biocytin-filled electrodes we recorded R-LM interneurons intracellularly in vitro and determined their postsynaptic effects in concomitantly recorded pyramidal cells. Light microscopic analysis revealed four populations of R-LM interneurons with distinct axons: (1) basket cells (n= 4) with axons predominantly ramifying in the pyramidal cell layer; (2) Schaffer collateral/commissural pathway-associated interneurons (n= 10) stratifying in stratum radiatum and, to a lesser extent, stratum oriens; (3) perforant pathway-associated interneurons (n= 6) innervating the perforant path termination zone in stratum lacunosum-moleculare of the CA1 area as well as equivalent portions of the dentate gyrus and subiculum; and (4) neurogliaform interneurons (n= 2) characterized by their dense, compact axonal and dendritic arbour. Random electron microscopic sampling of synaptic targets revealed a preponderance of pyramidal neurons as postsynaptic elements. Basket cells had a synaptic target preference for somata and proximal dendrites, whereas the remainder of R-LM interneurons innervated dendritic shafts and spines. The axon of dendrite-targeting cells formed up to six putative contacts with individual postsynaptic pyramidal cells. Anatomically recovered R-LM interneurons (n= 22) had a mean resting membrane potential of -56.7 ± 3.6 mV, a membrane time constant of 12.9 ± 7.7 ms and an input resistance of 86.4 ± 29.2 MΩ. Depolarizing current pulses generally elicited overshooting action potentials (70.8 ± 6.9 mV) which had a mean duration, when measured at half-amplitude, of 0.7 ± 0.1 ms. In response to prolonged (> 200 ms) depolarizing current pulses all R-LM interneurons displayed (a varying degree of) spike frequency adaptation. Basket cells, Schaffer-associated and neurogliaform interneurons elicited small-amplitude (< 2 mV), short-latency IPSPs in postsynaptic pyramids (n= 5, 13 and 1, respectively). Those interactions in which an effect was elicited with the repetitive activation of the presynaptic neuron (n= 13) showed a substantial degree of postsynaptic response summation. Unitary IPSPs had fast kinetics and, whenever tested (n= 5; 1 basket cell and 4 Schaffer-associated interneurons), were abolished by the GABAA receptor antagonist bicuculline. Thus, R-LM interneurons comprise several distinct populations which evoke fast GABAA receptor-mediated IPSPs. The domain-specific innervation of postsynaptic pyramidal cells suggests functionally diverse effects on the integration of afferent information in functionally non-equivalent compartments of pyramidal cells. PMID:9503336

The 4-aminopyridine in vitro epilepsy model analyzed with a perforated multi-electrode array.

PubMed

Gonzalez-Sulser, Alfredo; Wang, Jing; Motamedi, Gholam K; Avoli, Massimo; Vicini, Stefano; Dzakpasu, Rhonda

2011-06-01

Epileptiform discharges recorded in the 4-aminopyridine (4-AP) in vitro epilepsy model are mediated by glutamatergic and GABAergic signaling. Using a 60-channel perforated multi-electrode array (pMEA) on corticohippocampal slices from 2 to 3 week old mice we recorded interictal- and ictal-like events. When glutamatergic transmission was blocked, interictal-like events no longer initiated in the hilus or CA3/CA1 pyramidal layers but originated from the dentate gyrus granule and molecular layers. Furthermore, frequencies of interictal-like events were reduced and durations were increased in these regions while cortical discharges were completely blocked. Following GABA(A) receptor blockade interictal-like events no longer propagated to the dentate gyrus while their frequency in CA3 increased; in addition, ictal-like cortical events became shorter while increasing in frequency. Lastly, drugs that affect tonic and synaptic GABAergic conductance modulated the frequency, duration, initiation and propagation of interictal-like events. These findings confirm and expand on previous studies indicating that multiple synaptic mechanisms contribute to synchronize neuronal network activity in forebrain structures. This article is part of a Special Issue entitled 'Trends in neuropharmacology: in memory of Erminio Costa'. Copyright © 2010 Elsevier Ltd. All rights reserved.

Method of manufacturing a heat pipe wick with structural enhancement

DOEpatents

Andraka, Charles E [Albuquerque, NM; Adkins, Douglas R [Albuquerque, NM; Moreno, James B [Albuquerque, NM; Rawlinson, K Scott [Albuquerque, NM; Showalter, Steven K [Albuquerque, NM; Moss, Timothy A [Albuquerque, NM

2006-10-24

Heat pipe wick structure wherein a stout sheet of perforated material overlays a high performance wick material such as stainless steel felt affixed to a substrate. The inventive structure provides a good flow path for working fluid while maintaining durability and structural stability independent of the structure (or lack of structure) associated with the wick material. In one described embodiment, a wick of randomly laid .about.8 micron thickness stainless steel fibers is sintered to a metal substrate and a perforated metal overlay.

Heat pipe wick with structural enhancement

DOEpatents

Andraka, Charles E.; Adkins, Douglas R.; Moreno, James B.; Rawlinson, K. Scott; Showalter, Steven K.; Moss, Timothy A.

2003-11-18

Heat pipe wick structure wherein a stout sheet of perforated material overlays a high performance wick material such as stainless steel felt affixed to a substrate. The inventive structure provides a good flow path for working fluid while maintaining durability and structural stability independent of the structure (or lack of structure) associated with the wick material. In one described embodiment, a wick of randomly laid .about.8 micron thickness stainless steel fibers is sintered to a metal substrate and a perforated metal overlay.

The discovery of long-term potentiation.

PubMed

Lømo, Terje

2003-04-29

This paper describes circumstances around the discovery of long-term potentiation (LTP). In 1966, I had just begun independent work for the degree of Dr medicinae (PhD) in Per Andersen's laboratory in Oslo after an eighteen-month apprenticeship with him. Studying the effects of activating the perforant path to dentate granule cells in the hippocampus of anaesthetized rabbits, I observed that brief trains of stimuli resulted in increased efficiency of transmission at the perforant path-granule cell synapses that could last for hours. In 1968, Tim Bliss came to Per Andersen's laboratory to learn about the hippocampus and field potential recording for studies of possible memory mechanisms. The two of us then followed up my preliminary results from 1966 and did the experiments that resulted in a paper that is now properly considered to be the basic reference for the discovery of LTP.

Harvest maturity and post-processing dip to improve quality of fresh-cut carambola fruit

USDA-ARS?s Scientific Manuscript database

'Arkin' carambola (Averrhoa carambola L.) fruit harvested at color break or full yellow stage were washed with or without an alkaline solution (pH 13.5), cut to 1 cm thick slices, dipped in calcium ascorbate (Ca ASA), ascorbic acid (ASA) or water, and packaged in perforated clamshells for up to 14 d...

The discovery of long-term potentiation.

PubMed Central

Lømo, Terje

2003-01-01

This paper describes circumstances around the discovery of long-term potentiation (LTP). In 1966, I had just begun independent work for the degree of Dr medicinae (PhD) in Per Andersen's laboratory in Oslo after an eighteen-month apprenticeship with him. Studying the effects of activating the perforant path to dentate granule cells in the hippocampus of anaesthetized rabbits, I observed that brief trains of stimuli resulted in increased efficiency of transmission at the perforant path-granule cell synapses that could last for hours. In 1968, Tim Bliss came to Per Andersen's laboratory to learn about the hippocampus and field potential recording for studies of possible memory mechanisms. The two of us then followed up my preliminary results from 1966 and did the experiments that resulted in a paper that is now properly considered to be the basic reference for the discovery of LTP. PMID:12740104

Functional states of rat cortical circuits during the unpredictable availability of a reward-related cue

PubMed Central

Fernández-Lamo, Iván; Sánchez-Campusano, Raudel; Gruart, Agnès; Delgado-García M, José M.

2016-01-01

Proper performance of acquired abilities can be disturbed by the unexpected occurrence of external changes. Rats trained with an operant conditioning task (to press a lever in order to obtain a food pellet) using a fixed-ratio (1:1) schedule were subsequently placed in a Skinner box in which the lever could be removed randomly. Field postsynaptic potentials (fPSPs) were chronically evoked in perforant pathway-hippocampal CA1 (PP-CA1), CA1-subiculum (CA1-SUB), CA1-medial prefrontal cortex (CA1-mPFC), mPFC-nucleus accumbens (mPFC-NAc), and mPFC-basolateral amygdala (mPFC-BLA) synapses during lever IN and lever OUT situations. While lever presses were accompanied by a significant increase in fPSP slopes at the five synapses, the unpredictable absence of the lever were accompanied by decreased fPSP slopes in all, except PP-CA1 synapses. Spectral analysis of local field potentials (LFPs) recorded when the animal approached the corresponding area in the lever OUT situation presented lower spectral powers than during lever IN occasions for all recording sites, apart from CA1. Thus, the unpredictable availability of a reward-related cue modified the activity of cortical and subcortical areas related with the acquisition of operant learning tasks, suggesting an immediate functional reorganization of these neural circuits to address the changed situation and to modify ongoing behaviors accordingly. PMID:27869181

A rabbit ventricular action potential model replicating cardiac dynamics at rapid heart rates.

PubMed

Mahajan, Aman; Shiferaw, Yohannes; Sato, Daisuke; Baher, Ali; Olcese, Riccardo; Xie, Lai-Hua; Yang, Ming-Jim; Chen, Peng-Sheng; Restrepo, Juan G; Karma, Alain; Garfinkel, Alan; Qu, Zhilin; Weiss, James N

2008-01-15

Mathematical modeling of the cardiac action potential has proven to be a powerful tool for illuminating various aspects of cardiac function, including cardiac arrhythmias. However, no currently available detailed action potential model accurately reproduces the dynamics of the cardiac action potential and intracellular calcium (Ca(i)) cycling at rapid heart rates relevant to ventricular tachycardia and fibrillation. The aim of this study was to develop such a model. Using an existing rabbit ventricular action potential model, we modified the L-type calcium (Ca) current (I(Ca,L)) and Ca(i) cycling formulations based on new experimental patch-clamp data obtained in isolated rabbit ventricular myocytes, using the perforated patch configuration at 35-37 degrees C. Incorporating a minimal seven-state Markovian model of I(Ca,L) that reproduced Ca- and voltage-dependent kinetics in combination with our previously published dynamic Ca(i) cycling model, the new model replicates experimentally observed action potential duration and Ca(i) transient alternans at rapid heart rates, and accurately reproduces experimental action potential duration restitution curves obtained by either dynamic or S1S2 pacing.

Nuclear Membranes ETB Receptors Mediate ET-1-induced Increase of Nuclear Calcium in Human Left Ventricular Endocardial Endothelial Cells.

PubMed

Jules, Farah; Avedanian, Levon; Al-Khoury, Johny; Keita, Ramatoulaye; Normand, Alexandre; Bkaily, Ghassan; Jacques, Danielle

2015-07-01

In fetal human left ventricular endocardial endothelial cells (EECLs), both plasma membrane (PM) ET(A)R and ET(B)R were reported to mediate ET-1-induced increase of intracellular calcium [Ca](i); however, this effect was mediated by ET(A)R in right EECs (EECRs). In this study, we verified whether, as for the PM, nuclear membranes (NMs) ET-1 receptors activation in EECLs and EECRs induce an increase of nuclear calcium ([Ca](n)) and if this effect is mediated through the same receptor type as in PM. Using a plasmalemma-perforated technique and 3D confocal microscopy, our results showed that, as in PM intact cells, superfusion of nuclei of both cell types with cytosolic ET-1 induced a concentration-dependent sustained increase of [Ca](n). In EECRs, the ET(A)R antagonist prevented the effect of ET-1 on [Ca](n) without affecting EECLs. However, in both cell types, the effect of cytosolic ET-1 on [Ca](n) was prevented by the ETBR antagonist. In conclusion, both NMs' ET(A)R and ET(B)R mediated the effect of cytosolic ET-1 on [Ca](n) in EECRs. In contrast, only NMs' ET(B)R activation mediated the effect of cytosolic ET-1 in EECLs. Hence, the type of NMs' receptors mediating the effect of ET-1 on [Ca](n) are different from those of PM mediating the increase in [Ca](i).

Cytoreductive surgery and hyperthermic intraperitoneal chemotherapy in 1000 patients with perforated appendiceal epithelial tumours.

PubMed

Ansari, N; Chandrakumaran, K; Dayal, S; Mohamed, F; Cecil, T D; Moran, B J

2016-07-01

To report early and long term outcomes following cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) in 1000 patients with perforated appendiceal epithelial tumours, predominantly with pseudomyxoma peritonei (PMP). Retrospective analysis of a prospective database of 1000 consecutive patients undergoing CRS and HIPEC for perforated appendiceal tumours between 1994 and 2014 in a UK National Peritoneal Malignancy unit. Overall 1000/1444 (69.2%) patients treated for peritoneal malignancy had appendiceal primary tumours. Of these 738/1000 (73.8%) underwent complete cytoreductive surgery (CCRS), 242 (24.2%) had maximal tumour debulking (MTD) and 20 (2%) had laparotomy and biopsies only. Treatment related 30-day mortality was 0.8% in CCRS and 1.7% in MTD group with major postoperative morbidity rates of 15.2% (CCRS) and 14.5% (MTD). Five- and 10-year overall survival was 87.4% and 70.3% in the 738 patients who had CCRS compared with 39.2% and 8.1% respectively in the MTD group. On multivariate analysis, significant predictors of reduced overall survival were male gender (p = 0.022), elevated CEA (p = 0.001), elevated CA125 (p = 0.001) and high tumour grade or adenocarcinoma (p = 0.001). Perforated epithelial appendiceal tumours are rare, though may be increasing in incidence and can present unexpectedly at elective or emergency abdominal surgery, often with PMP. CRS and HIPEC results in good long term outcomes in most patients. Copyright © 2016 Elsevier Ltd. All rights reserved.

Impaired synaptic clustering of postsynaptic density proteins and altered signal transmission in hippocampal neurons, and disrupted learning behavior in PDZ1 and PDZ2 ligand binding-deficient PSD-95 knockin mice

PubMed Central

2012-01-01

Background Postsynaptic density (PSD)-95-like membrane-associated guanylate kinases (PSD-MAGUKs) are scaffold proteins in PSDs that cluster signaling molecules near NMDA receptors. PSD-MAGUKs share a common domain structure, including three PDZ (PDZ1/2/3) domains in their N-terminus. While multiple domains enable the PSD-MAGUKs to bind various ligands, the contribution of each PDZ domain to synaptic organization and function is not fully understood. Here, we focused on the PDZ1/2 domains of PSD-95 that bind NMDA-type receptors, and studied the specific roles of the ligand binding of these domains in the assembly of PSD proteins, synaptic properties of hippocampal neurons, and behavior, using ligand binding-deficient PSD-95 cDNA knockin (KI) mice. Results The KI mice showed decreased accumulation of mutant PSD-95, PSD-93 and AMPA receptor subunits in the PSD fraction of the hippocampus. In the hippocampal CA1 region of young KI mice, basal synaptic efficacy was reduced and long-term potentiation (LTP) was enhanced with intact long-term depression. In adult KI mice, there was no significant change in the magnitude of LTP in CA1, but robustly enhanced LTP was induced at the medial perforant path-dentate gyrus synapses, suggesting that PSD-95 has an age- and subregion-dependent role. In a battery of behavioral tests, KI mice showed markedly abnormal anxiety-like behavior, impaired spatial reference and working memory, and impaired remote memory and pattern separation in fear conditioning test. Conclusions These findings reveal that PSD-95 including its ligand binding of the PDZ1/2 domains controls the synaptic clustering of PSD-MAGUKs and AMPA receptors, which may have an essential role in regulating hippocampal synaptic transmission, plasticity, and hippocampus-dependent behavior. PMID:23268962

Impaired synaptic clustering of postsynaptic density proteins and altered signal transmission in hippocampal neurons, and disrupted learning behavior in PDZ1 and PDZ2 ligand binding-deficient PSD-95 knockin mice.

PubMed

Nagura, Hitoshi; Ishikawa, Yasuyuki; Kobayashi, Katsunori; Takao, Keizo; Tanaka, Tomo; Nishikawa, Kouki; Tamura, Hideki; Shiosaka, Sadao; Suzuki, Hidenori; Miyakawa, Tsuyoshi; Fujiyoshi, Yoshinori; Doi, Tomoko

2012-12-26

Postsynaptic density (PSD)-95-like membrane-associated guanylate kinases (PSD-MAGUKs) are scaffold proteins in PSDs that cluster signaling molecules near NMDA receptors. PSD-MAGUKs share a common domain structure, including three PDZ (PDZ1/2/3) domains in their N-terminus. While multiple domains enable the PSD-MAGUKs to bind various ligands, the contribution of each PDZ domain to synaptic organization and function is not fully understood. Here, we focused on the PDZ1/2 domains of PSD-95 that bind NMDA-type receptors, and studied the specific roles of the ligand binding of these domains in the assembly of PSD proteins, synaptic properties of hippocampal neurons, and behavior, using ligand binding-deficient PSD-95 cDNA knockin (KI) mice. The KI mice showed decreased accumulation of mutant PSD-95, PSD-93 and AMPA receptor subunits in the PSD fraction of the hippocampus. In the hippocampal CA1 region of young KI mice, basal synaptic efficacy was reduced and long-term potentiation (LTP) was enhanced with intact long-term depression. In adult KI mice, there was no significant change in the magnitude of LTP in CA1, but robustly enhanced LTP was induced at the medial perforant path-dentate gyrus synapses, suggesting that PSD-95 has an age- and subregion-dependent role. In a battery of behavioral tests, KI mice showed markedly abnormal anxiety-like behavior, impaired spatial reference and working memory, and impaired remote memory and pattern separation in fear conditioning test. These findings reveal that PSD-95 including its ligand binding of the PDZ1/2 domains controls the synaptic clustering of PSD-MAGUKs and AMPA receptors, which may have an essential role in regulating hippocampal synaptic transmission, plasticity, and hippocampus-dependent behavior.

A Comparison of Different Slicing Planes in Preservation of Major Hippocampal Pathway Fibers in the Mouse

PubMed Central

Xiong, Guoxiang; Metheny, Hannah; Johnson, Brian N.; Cohen, Akiva S.

2017-01-01

The hippocampus plays a critical role in learning and memory and higher cognitive functions, and its dysfunction has been implicated in various neuropathological disorders. Electrophysiological recording undertaken in live brain slices is one of the most powerful tools for investigating hippocampal cellular and network activities. The plane for cutting the slices determines which afferent and/or efferent connections are best preserved, and there are three commonly used slices: hippocampal-entorhinal cortex (HEC), coronal and transverse. All three slices have been widely used for studying the major afferent hippocampal pathways including the perforant path (PP), the mossy fibers (MFs) and the Schaffer collaterals (SCs). Surprisingly, there has never been a systematic investigation of the anatomical and functional consequences of slicing at a particular angle. In the present study, we focused on how well fiber pathways are preserved from the entorhinal cortex (EC) to the hippocampus, and within the hippocampus, in slices generated by sectioning at different angles. The postmortem neural tract tracer 1,1′-dioctadecyl-3,3,3′3′-tetramethylindocarbocyanine perchlorate (DiI) was used to label afferent fibers to hippocampal principal neurons in fixed slices or whole brains. Laser scanning confocal microscopy was adopted for imaging DiI-labeled axons and terminals. We demonstrated that PP fibers were well preserved in HEC slices, MFs in both HEC and transverse slices and SCs in all three types of slices. Correspondingly, field excitatory postsynaptic potentials (fEPSPs) could be consistently evoked in HEC slices when stimulating PP fibers and recorded in stratum lacunosum-moleculare (sl-m) of area CA1, and when stimulating the dentate granule cell layer (gcl) and recording in stratum lucidum (sl) of area CA3. The MF evoked fEPSPs could not be recorded in CA3 from coronal slices. In contrast to our DiI-tracing data demonstrating severely truncated PP fibers in coronal slices, fEPSPs could still be recorded in CA1 sl-m in this plane, suggesting that an additional afferent fiber pathway other than PP might be involved. The present study increases our understanding of which hippocampal pathways are best preserved in the three most common brain slice preparations, and will help investigators determine the appropriate slices to use for physiological studies depending on the subregion of interest. PMID:29201002

Flue Gas Desulfurization at Navy Bases, Navy Energy Guidance Study. Phase IV.

DTIC Science & Technology

1980-08-01

WA08O9 146 BECHTEL NATIONAL INC SAN FRANCISCO CA FLUE GAS DESULFURIZATION AT NAVY BASES, NAVY ENERGY GUIDANCE ST-ETC(U) AUG 80 A I MCCONE N68305-77C... Flue gas desulfurization 10. ABSTRACT (C lno d. It -.4..,.d id-1, by 61-hb n-.1..) A study o e availability, costs, and operating perfor- nce of...industral-sized flue gas desulfurization (FGD) systems or coal-fired boilers 4...- mrfmmed for-the Civil Englneering- , - boratory at the Naval Construction

The Cognition and Neuroergonomics (CaN) Collaborative Technology Alliance (CTA): Scientific Vision, Approach, and Translational Paths

DTIC Science & Technology

2012-09-01

The Cognition and Neuroergonomics (CaN) Collaborative Technology Alliance (CTA): Scientific Vision, Approach, and Translational Paths by...The Cognition and Neuroergonomics (CaN) Collaborative Technology Alliance (CTA): Scientific Vision, Approach, and Translational Paths Kelvin S. Oie...REPORT DATE (DD-MM-YYYY) September 2012 2. REPORT TYPE Final 3. DATES COVERED (From - To) 4. TITLE AND SUBTITLE The Cognition and Neuroergonomics

Age-related Changes in Lateral Entorhinal and CA3 Neuron Allocation Predict Poor Performance on Object Discrimination

PubMed Central

Maurer, Andrew P.; Johnson, Sarah A.; Hernandez, Abbi R.; Reasor, Jordan; Cossio, Daniela M.; Fertal, Kaeli E.; Mizell, Jack M.; Lubke, Katelyn N.; Clark, Benjamin J.; Burke, Sara N.

2017-01-01

Age-related memory deficits correlate with dysfunction in the CA3 subregion of the hippocampus, which includes both hyperactivity and overly rigid activity patterns. While changes in intrinsic membrane currents and interneuron alterations are involved in this process, it is not known whether alterations in afferent input to CA3 also contribute. Neurons in layer II of the lateral entorhinal cortex (LEC) project directly to CA3 through the perforant path, but no data are available regarding the effects of advanced age on LEC activity and whether these activity patterns update in response to environmental change. Furthermore, it is not known the extent to which age-related deficits in sensory discrimination relate to the inability of aged CA3 neurons to update in response to new environments. Young and aged rats were pre-characterized on a LEGO© object discrimination task, comparable to behavioral tests in humans in which CA3 hyperactivity has been linked to impairments. The cellular compartment analysis of temporal activity with fluorescence in situ hybridization for the immediate-early gene Arc was then used to identify the principal cell populations that were active during two distinct epochs of random foraging in different environments. This approach enabled the extent to which rats could discriminate two similar objects to be related to the ability of CA3 neurons to update across different environments. In both young and aged rats, there were animals that performed poorly on the LEGO object discrimination task. In the aged rats only, however, the poor performers had a higher percent of CA3 neurons that were active during random foraging in a novel environment, but this is not related to the ability of CA3 neurons to remap when the environment changed. Afferent neurons to CA3 in LEC, as identified with the retrograde tracer choleratoxin B (CTB), also showed a higher percentage of cells that were positive for Arc mRNA in aged poor performing rats. This suggests that LEC contributes to the hyperactivity seen in CA3 of aged animals with object discrimination deficits and age-related cognitive decline may be the consequence of dysfunction endemic to the larger network. PMID:28713251

Antarctica and global paleogeography: from Rodinia, rhrough Gondwanaland and Pangea, to the birth of the Southern Ocean and the opening of gateways

USGS Publications Warehouse

Torsvik, T.H.; Gaina, C.; Redfield, T.F.

2007-01-01

Neoproterozoic Rodinia reconstructions associate East Antarctica (EANT) with cratonic Western Australia. By further linking EANT to both Gondwana and Pangea with relative plate circuits, a Synthetic Apparent Polar Wander (SAPW) path for EANT is calculated. This path predicts that EANT was located at tropical to subtropical southerly latitudes from ca. 1 Ga to 420 Ma. Around 400 Ma and again at 320 Ma, EANT underwent southward drift. Ca. 250 Ma Antarctica voyaged briefly north but headed south again ca. 200 Ma. Since 75 Ma EANT became surrounded by spreading centers and has remained extremely stable. Although paleomagnetic data of the blocks that embrace West Antarctica are sparse, we attempt to model their complex kinematics since the Mesozoic. Together with the SAPW path and a revised circum-Antarctic seafloor spreading history we construct a series of new paleogeographic maps.

Block of Na(+)/Ca(2+) exchanger by SEA0400 in human right atrial preparations from patients in sinus rhythm and in atrial fibrillation.

PubMed

Christ, Torsten; Kovács, Peter P; Acsai, Karoly; Knaut, Michael; Eschenhagen, Thomas; Jost, Norbert; Varró, András; Wettwer, Erich; Ravens, Ursula

2016-10-05

The Na(+)/Ca(2+) exchanger (NCX) plays a major role in myocardial Ca(2+) homoeostasis, but is also considered to contribute to the electrical instability and contractile dysfunction in chronic atrial fibrillation (AF). Here we have investigated the effects of the selective NCX blocker SEA0400 in human right atrial cardiomyocytes from patients in sinus rhythm (SR) and AF in order to obtain electrophysiological evidence for putative antiarrhythmic activity of this new class of drugs. Action potentials were measured in right atrial trabeculae using conventional microelectrodes. Human myocytes were enzymatically isolated. Rat atrial and ventricular cardiomyocytes were used for comparison. Using perforated-patch, NCX was measured as Ni(2+)-sensitive current during ramp pulses. In ruptured-patch experiments, NCX current was activated by changing the extracellular Ca(2+) concentration from 0 to 1mM in Na(+)-free bath solution (100mM Na(+) intracellular, "Hilgemann protocol"). Although SEA0400 was effective in rat cardiomyocytes, 10µM did not influence action potentials and contractility, neither in SR nor AF. SEA0400 (10μM) also failed to affect human atrial NCX current measured with perforated patch. With the "Hilgemann protocol" SEA0400 concentration-dependently suppressed human atrial NCX current, and its amplitude was larger in AF than in SR cardiomyocytes. Our results confirm higher NCX activity in AF than SR. SEA0400 fails to block Ni(2+)-sensitive current in human atrial cells unless unphysiological conditions are used. We speculate that block of NCX with SEA0400 depends on intracellular Na(+) concentration. Copyright © 2016 Elsevier B.V. All rights reserved.

Effects of ocean acidification on the dissolution rates of reef-coral skeletons.

PubMed

van Woesik, Robert; van Woesik, Kelly; van Woesik, Liana; van Woesik, Sandra

2013-01-01

Ocean acidification threatens the foundation of tropical coral reefs. This study investigated three aspects of ocean acidification: (i) the rates at which perforate and imperforate coral-colony skeletons passively dissolve when pH is 7.8, which is predicted to occur globally by 2100, (ii) the rates of passive dissolution of corals with respect to coral-colony surface areas, and (iii) the comparative rates of a vertical reef-growth model, incorporating passive dissolution rates, and predicted sea-level rise. By 2100, when the ocean pH is expected to be 7.8, perforate Montipora coral skeletons will lose on average 15 kg CaCO3 m(-2) y(-1), which is approximately -10.5 mm of vertical reduction of reef framework per year. This rate of passive dissolution is higher than the average rate of reef growth over the last several millennia and suggests that reefs composed of perforate Montipora coral skeletons will have trouble keeping up with sea-level rise under ocean acidification. Reefs composed of primarily imperforate coral skeletons will not likely dissolve as rapidly, but our model shows they will also have trouble keeping up with sea-level rise by 2050.

Development of the Circulation Control Flow Scheme Used in the NTF Semi-Span FAST-MAC Model

NASA Technical Reports Server (NTRS)

Jones, Gregory S.; Milholen, William E., II; Chan, David T.; Allan, Brian G.; Goodliff, Scott L.; Melton, Latunia P.; Anders, Scott G.; Carter, Melissa B.; Capone, Francis J.

2013-01-01

The application of a circulation control system for high Reynolds numbers was experimentally validated with the Fundamental Aerodynamic Subsonic Transonic Modular Active Control semi-span model in the NASA Langley National Transonic Facility. This model utilized four independent flow paths to modify the lift and thrust performance of a representative advanced transport type of wing. The design of the internal flow paths highlights the challenges associated with high Reynolds number testing in a cryogenic pressurized wind tunnel. Weight flow boundaries for the air delivery system were identified at mildly cryogenic conditions ranging from 0.1 to 10 lbm/sec. Results from the test verified system performance and identified solutions associated with the weight-flow metering system that are linked to internal perforated plates used to achieve flow uniformity at the jet exit.

Limiting factors and landscape connectivity: the American marten in the Rocky Mountains

Treesearch

S. A. Cushman; M. G. Raphael; L. F. Ruggiero; A. S. Shirk; T. N. Wasserman; E. C. O' Doherty

2011-01-01

In mobile animals, movement behavior can maximize fitness by optimizing access to critical resources and minimizing risk of predation. We sought to evaluate several hypotheses regarding the effects of landscape structure on American marten foraging path selection in a landscape experiencing forest perforation by patchcut logging. We hypothesized that in the uncut pre-...

Correlation of Soot Formation in Turbojet Engines and in Laboratory Flames.

DTIC Science & Technology

1981-02-01

measured dependent variables were the flame radiation in the primary combustion zone and tile combus- tor liner temperature. Naegeli and Moses...Can-Type Turbine Combustion Systems," AFAPL- TR-79-2072, General Motors Corporation, April 1980. 9. Moses, C.A. and Naegeli , D.W., "Fuel Property...Effects on Combustor Perfor- mance," MED 114, Southwest Research Institute, March 1980. 10. Moses, C.A. and Naegeli , D.W., "Fuel Property Effects on

Experimental observation of charge-shift bond in fluorite CaF2.

PubMed

Stachowicz, Marcin; Malinska, Maura; Parafiniuk, Jan; Woźniak, Krzysztof

2017-08-01

On the basis of a multipole refinement of single-crystal X-ray diffraction data collected using an Ag source at 90 K to a resolution of 1.63 Å -1 , a quantitative experimental charge density distribution has been obtained for fluorite (CaF 2 ). The atoms-in-molecules integrated experimental charges for Ca 2+ and F - ions are +1.40 e and -0.70 e, respectively. The derived electron-density distribution, maximum electron-density paths, interaction lines and bond critical points along Ca 2+ ...F - and F - ...F - contacts revealed the character of these interactions. The Ca 2+ ...F - interaction is clearly a closed shell and ionic in character. However, the F - ...F - interaction has properties associated with the recently recognized type of interaction referred to as `charge-shift' bonding. This conclusion is supported by the topology of the electron localization function and analysis of the quantum theory of atoms in molecules and crystals topological parameters. The Ca 2+ ...F - bonded radii - measured as distances from the centre of the ion to the critical point - are 1.21 Å for the Ca 2+ cation and 1.15 Å for the F - anion. These values are in a good agreement with the corresponding Shannon ionic radii. The F - ...F - bond path and bond critical point is also found in the CaF 2 crystal structure. According to the quantum theory of atoms in molecules and crystals, this interaction is attractive in character. This is additionally supported by the topology of non-covalent interactions based on the reduced density gradient.

Selective alterations of neurons and circuits related to early memory loss in Alzheimer’s disease

PubMed Central

Llorens-Martín, Maria; Blazquez-Llorca, Lidia; Benavides-Piccione, Ruth; Rabano, Alberto; Hernandez, Felix; Avila, Jesus; DeFelipe, Javier

2014-01-01

A progressive loss of episodic memory is a well-known clinical symptom that characterizes Alzheimer’s disease (AD). The beginning of this loss of memory has been associated with the very early, pathological accumulation of tau and neuronal degeneration observed in the entorhinal cortex (EC). Tau-related pathology is thought to then spread progressively to the hippocampal formation and other brain areas as the disease progresses. The major cortical afferent source of the hippocampus and dentate gyrus is the EC through the perforant pathway. At least two main circuits participate in the connection between EC and the hippocampus; one originating in layer II and the other in layer III of the EC giving rise to the classical trisynaptic (ECII → dentate gyrus → CA3 → CA1) and monosynaptic (ECIII → CA1) circuits. Thus, the study of the early pathological changes in these circuits is of great interest. In this review, we will discuss mainly the alterations of the granule cell neurons of the dentate gyrus and the atrophy of CA1 pyramidal neurons that occur in AD in relation to the possible differential alterations of these two main circuits. PMID:24904307

Selective alterations of neurons and circuits related to early memory loss in Alzheimer's disease.

PubMed

Llorens-Martín, Maria; Blazquez-Llorca, Lidia; Benavides-Piccione, Ruth; Rabano, Alberto; Hernandez, Felix; Avila, Jesus; DeFelipe, Javier

2014-01-01

A progressive loss of episodic memory is a well-known clinical symptom that characterizes Alzheimer's disease (AD). The beginning of this loss of memory has been associated with the very early, pathological accumulation of tau and neuronal degeneration observed in the entorhinal cortex (EC). Tau-related pathology is thought to then spread progressively to the hippocampal formation and other brain areas as the disease progresses. The major cortical afferent source of the hippocampus and dentate gyrus is the EC through the perforant pathway. At least two main circuits participate in the connection between EC and the hippocampus; one originating in layer II and the other in layer III of the EC giving rise to the classical trisynaptic (ECII → dentate gyrus → CA3 → CA1) and monosynaptic (ECIII → CA1) circuits. Thus, the study of the early pathological changes in these circuits is of great interest. In this review, we will discuss mainly the alterations of the granule cell neurons of the dentate gyrus and the atrophy of CA1 pyramidal neurons that occur in AD in relation to the possible differential alterations of these two main circuits.

Rotary plant growth accelerating apparatus. [weightlessness

NASA Technical Reports Server (NTRS)

Dedolph, R. D. (Inventor)

1975-01-01

Rotary plant growth accelerating apparatus for increasing plant yields by effectively removing the growing plants from the constraints of gravity and increasing the plant yield per unit of space is described. The apparatus is comprised of cylindrical plant beds supported radially removed from a primary axis of rotation, with each plant bed being driven about its own secondary axis of rotation and simultaneously moved in a planetary path about the primary axis of rotation. Each plant bed is formed by an apertured outer cylinder, a perforated inner cylinder positioned coaxially, and rooting media disposed in the space between. A rotatable manifold distributes liquid nutrients and water to the rooting media through the perforations in the inner cylinders as the plant beds are continuously rotated by suitable drive means.

Mechanisms to Explain the Elemental Composition of the Initial Aragonite Shell of Larval Oysters

NASA Astrophysics Data System (ADS)

Haley, Brian A.; Hales, Burke; Brunner, Elizabeth L.; Kovalchik, Kevin; Waldbusser, George G.

2018-04-01

Calcifying organisms face increasing stress from the changing carbonate chemistry of an acidifying ocean, particularly bivalve larvae that live in upwelling regions of the world, such as the coastal and estuarine waters of Oregon (USA). Arguably the first and most significant developmental hurdle faced by larval oysters is formation of their initial prodissoconch I (PDI) shell, upon which further ontological development depends. We measured the minor metal compositions (Sr/Ca, Mg/Ca) of this aragonitic PDI shell and of post-PDI larval Crassostrea gigas shell, as well as the water they were reared in, over ˜20 days for a May and an August cohort in 2011, during which time there was no period of carbonate under-saturation. After testing various methods, we successfully isolated the shell from organic tissue using a 5% active chlorine bleach solution. Elemental compositions (Sr, Mg, C, N) of the shells post-treatment showed that shell Sr/Ca ranged from 1.55 to 1.82 mmol/mol; Mg/Ca from 0.60 to 1.11 mmol/mol, similar to the few comparable published data for larval oyster aragonite compositions. We compare these data in light of possible biomineralization mechanisms: an amorphous calcium carbonate (ACC) path, an intercellular path, and a direct-from-seawater path to shell formation via biologically induced inorganic precipitation of aragonite. The last option provides a mechanistic explanation for: (1) the accelerated precipitation rates of biogenic calcification in the absence of a calcifying fluid; (2) consistently elevated precipitation rates at varying ambient-water saturation states; and (3) the high Ca-selectivity of the early larval calcification despite rapid precipitation rates.

Cav 1.3 channels play a crucial role in the formation of paroxysmal depolarization shifts in cultured hippocampal neurons.

PubMed

Stiglbauer, Victoria; Hotka, Matej; Ruiß, Manuel; Hilber, Karlheinz; Boehm, Stefan; Kubista, Helmut

2017-05-01

An increase of neuronal Ca v 1.3 L-type calcium channels (LTCCs) has been observed in various animal models of epilepsy. However, LTCC inhibitors failed in clinical trials of epileptic treatment. There is compelling evidence that paroxysmal depolarization shifts (PDSs) involve Ca 2+ influx through LTCCs. PDSs represent a hallmark of epileptiform activity. In recent years, a probable epileptogenic role for PDSs has been proposed. However, the implication of the two neuronal LTCC isoforms, Ca v 1.2 and Ca v 1.3, in PDSs remained unknown. Moreover, Ca 2+ -dependent nonspecific cation (CAN) channels have also been suspected to contribute to PDSs. Nevertheless, direct experimental support of an important role of CAN channel activation in PDS formation is still lacking. Primary neuronal networks derived from dissociated hippocampal neurons were generated from mice expressing a dihydropyridine-insensitive Ca v 1.2 mutant (Ca v 1.2DHP -/- mice) or from Ca v 1.3 -/- knockout mice. To investigate the role of Ca v 1.2 and Ca v 1.3, perforated patch-clamp recordings were made of epileptiform activity, which was elicited using either bicuculline or caffeine. LTCC activity was modulated using the dihydropyridines Bay K 8644 (agonist) and isradipine (antagonist). Distinct PDS could be elicited upon LTCC potentiation in Ca v 1.2DHP -/- neurons but not in Ca v 1.3 -/- neurons. In contrast, when bicuculline led to long-lasting, seizure-like discharge events rather than PDS, these were prolonged in Ca v 1.3 -/- neurons but not in Ca v 1.2DHP -/- neurons. Because only the Ca v 1.2 isoform is functionally coupled to CAN channels in primary hippocampal networks, PDS formation does not require CAN channel activity. Our data suggest that the LTCC requirement of PDS relates primarily to Ca v 1.3 channels rather than to Ca v 1.2 channels and CAN channels in hippocampal neurons. Hence, Ca v 1.3 may represent a new therapeutic target for suppression of PDS development. The proposed epileptogenic role of PDSs may allow for a prophylactic rather than the unsuccessful seizure suppressing application of LTCC inhibitors. Wiley Periodicals, Inc. © 2017 International League Against Epilepsy.

Spectrum of perforation peritonitis in delhi: 77 cases experience.

PubMed

Yadav, Dinesh; Garg, Puneet K

2013-04-01

Perforation peritonitis is the most common surgical emergency encountered by surgeons all over the world as well in India. The spectrum of etiology of perforation peritonitis in tropical countries continues to differ from its western counterpart. This study was conducted at Hindu Rao Hospital, Municipal Corporation of Delhi, New Delhi, India, designed to highlight the spectrum of perforation peritonitis in the eastern countries and to improve its outcome. This prospective study included 77 consecutive patients of perforation peritonitis studied in terms of clinical presentations, causes, site of perforation, surgical treatment, postoperative complications, and mortality at Hindu Rao Hospital, Delhi, from March 1, 2011 to December 1, 2011, over a period of 8 months. All patients were resuscitated and underwent emergency exploratory laparotomy. On laparotomy cause of perforation peritonitis was found and controlled. The most common cause of perforation peritonitis noticed in our series was perforated duodenal ulcer (26.4 %) and ileal typhoid perforation (26.4 %), each followed by small bowel tuberculosis (10.3 %) and stomach perforation (9.2 %), perforation due to acute appendicitis (5 %). The highest number of perforations was seen in ileum (39.1 %), duodenum (26.4 %), stomach (11.5 %), appendix (3.5 %), jejunum (4.6 %), and colon (3.5 %). Overall mortality was 13 %. The spectrum of perforation peritonitis in India continuously differs from western countries. The highest number of perforations was noticed in the upper part of the gastrointestinal tract as compared to the western countries where the perforations seen mostly in the distal part. The most common cause of perforation peritonitis was perforated duodenal ulcer and small bowel typhoid perforation followed by typhoid perforation. Large bowel perforations and malignant perforations were least common in our setup.

Theoretical study on the potential energy surfaces of CaNC and CaCN

NASA Astrophysics Data System (ADS)

Ishii, Keisaku; Taketsugu, Tetsuya; Hirano, Tsuneo

2003-06-01

The potential energy surfaces of CaNC ( overlineX2Σ+) and CaCN ( overlineX2Σ+) have been investigated by the highly correlated ab initio molecular orbital methods. The bending potential for CaNC is shallow, and shows quite anharmonic and anomalous character, which can explain why the centrifugal distortion constants up to the tenth order were required for the analysis of its rotational spectrum. The reaction path for the isomerization reaction of CaNC and CaCN was also determined: The activation barrier is 2111 cm -1 from the CaNC side, and 602 cm -1 from the CaCN side. Core-core and core-valence correlation contributions of Ca M-shell electrons make the Ca-N (for CaNC) and Ca-C (for CaCN) bond lengths shorter by 0.05 and 0.04 Å, respectively, which indicates the significance of these core-correlation effects.

Structural plasticity: how intermetallics deform themselves in response to chemical pressure, and the complex structures that result.

PubMed

Berns, Veronica M; Fredrickson, Daniel C

2014-10-06

Interfaces between periodic domains play a crucial role in the properties of metallic materials, as is vividly illustrated by the way in which the familiar malleability of many metals arises from the formation and migration of dislocations. In complex intermetallics, such interfaces can occur as an integral part of the ground-state crystal structure, rather than as defects, resulting in such marvels as the NaCd2 structure (whose giant cubic unit cell contains more than 1000 atoms). However, the sources of the periodic interfaces in intermetallics remain mysterious, unlike the dislocations in simple metals, which can be associated with the exertion of physical stresses. In this Article, we propose and explore the concept of structural plasticity, the hypothesis that interfaces in complex intermetallic structures similarly result from stresses, but ones that are inherent in a defect-free parent structure, rather than being externally applied. Using DFT-chemical pressure analysis, we show how the complex structures of Ca2Ag7 (Yb2Ag7 type), Ca14Cd51 (Gd14Ag51 type), and the 1/1 Tsai-type quasicrystal approximant CaCd6 (YCd6 type) can all be traced to large negative pressures around the Ca atoms of a common progenitor structure, the CaCu5 type with its simple hexagonal 6-atom unit cell. Two structural paths are found by which the compounds provide relief to the Ca atoms' negative pressures: a Ca-rich pathway, where lower coordination numbers are achieved through defects eliminating transition metal (TM) atoms from the structure; and a TM-rich path, along which the addition of spacer Cd atoms provides the Ca coordination environments greater independence from each other as they contract. The common origins of these structures in the presence of stresses within a single parent structure highlights the diverse paths by which intermetallics can cope with competing interactions, and the role that structural plasticity may play in navigating this diversity.

Spectrum of perforation peritonitis in Pakistan: 300 cases Eastern experience.

PubMed

Afridi, Shahida Parveen; Malik, Faiza; Ur-Rahman, Shafiq; Shamim, Shahid; Samo, Khursheed A

2008-11-08

Perforation peritonitis is the most common surgical emergency encountered by the surgeons all over the world as well in Pakistan. The spectrum of etiology of perforation peritonitis in tropical countries continues to differ from its western counter part. This study was conducted at Dow University of health sciences and Civil Hospital Karachi (DUHS & CHK) Pakistan, designed to highlight the spectrum of perforation peritonitis in the East and to improve its outcome. A prospective study includes three hundred consecutive patients of perforation peritonitis studied in terms of clinical presentations, Causes, site of perforation, surgical treatment, post operative complications and mortality, at (DUHS&CHK) Pakistan, from 1st September 2005 - 1st March 2008, over a period of two and half years. All patients were resuscitated underwent emergency exploratory laparotomy. On laparotomy cause of perforation peritonitis was found and controlled. The most common cause of perforation peritonitis noticed in our series was acid peptic disease 45%, perforated duodenal ulcer (43.6%) and gastric ulcer 1.3%. followed by small bowel tuberculosis (21%) and typhoid (17%). large bowel perforation due to tuberculosis 5%, malignancy 2.6% and volvulus 0.3%. Perforation due to acute appendicitis (5%). Highest number of perforations has seen in the duodenum 43.6%, ileum37.6%, and colon 8%, appendix 5%, jejunum 3.3%, and stomach 2.3%. Overall mortality was (10.6%). The spectrum of perforation peritonitis in Pakistan continuously differs from western country. Highest number of perforations noticed in the upper part of the gastrointestinal tract as compared to the western countries where the perforations seen mostly in the distal part. Most common cause of perforation peritonitis is perforated duodenal ulcer, followed by small bowel tuberculosis and typhoid perforation. Majority of the large bowel perforations are also tubercular. Malignant perforations are least common in our setup.

Endogenous neurotrophin-3 regulates short-term plasticity at lateral perforant path-granule cell synapses.

PubMed

Kokaia, M; Asztely, F; Olofsdotter, K; Sindreu, C B; Kullmann, D M; Lindvall, O

1998-11-01

In the adult brain, neurotrophin-3 (NT-3) is mainly localized in dentate granule cells, and its expression is decreased by various stimuli, e.g., seizure activity. We have examined the role of endogenous NT-3 for excitatory synaptic transmission at lateral perforant path-dentate granule cell synapses using hippocampal slices from NT-3 knock-out (+/-) and wild-type (+/+) mice. Paired-pulse facilitation (PPF) and also short-term synaptic plasticity induced by a brief, high-frequency train of afferent stimulation were reduced, but the expression of long-term potentiation was not affected in the NT-3+/- mice. Incubation of the slices with recombinant NT-3 reversed the deficit in PPF through a mechanism requiring de novo protein synthesis, implying that the impaired short-term plasticity does not result from a developmental alteration. No changes of overall presynaptic release probability, measured by the progressive block of NMDA receptor-mediated synaptic currents by MK-801, or desensitization of AMPA receptors were detected. Because NT-3 expression is reduced after focal seizures, impaired short-term facilitation may represent a protective response that limits the propagation of epileptiform activity from the entorhinal cortex to the hippocampus.

The application of computed tomography in wound ballistics research

NASA Astrophysics Data System (ADS)

Tsiatis, Nick; Moraitis, Konstantinos; Papadodima, Stavroula; Spiliopoulou, Chara; Kelekis, Alexis; Kelesis, Christos; Efstathopoulos, Efstathios; Kordolaimi, Sofia; Ploussi, Agapi

2015-09-01

In wound ballistics research there is a relationship between the data that characterize a bullet and the injury resulted after shooting when it perforates the human body. The bullet path in the human body following skin perforation as well as the damaging effect cannot always be predictable as they depend on various factors such as the bullet's characteristics (velocity, distance, type of firearm and so on) and the tissue types that the bullet passes through. The purpose of this presentation is to highlight the contribution of Computed Tomography (CT) in wound ballistics research. Using CT technology and studying virtual “slices” of specific areas on scanned human bodies, allows the evaluation of density and thickness of the skin, the subcutaneous tissue, the muscles, the vital organs and the bones. Density data taken from Hounsfield units can be converted in g/ml by using the appropriate software. By evaluating the results of this study, the anatomy of the human body utilizing ballistic gel will be reproduced in order to simulate the path that a bullet follows. The biophysical analysis in wound ballistics provides another application of CT technology, which is commonly used for diagnostic and therapeutic purposes in various medical disciplines.

The accuracy and safety of fluoroscopic-guided percutaneous pedicle screws in the thoracic and lumbosacral spine in the Asian population: A CT scan analysis of 1002 screws.

PubMed

Chiu, Chee Kidd; Chan, Chris Yin Wei; Kwan, Mun Keong

2017-01-01

This study investigates the safety and accuracy of percutaneous pedicle screws placed using fluoroscopic guidance in the thoracolumbosacral spine among Asian patients. Computerized tomography scans of 128 patients who had surgery using fluoroscopic-guided percutaneous pedicle screws were selected. Medial, lateral, superior, and inferior screw perforations were classified into grade 0 (no violation), grade 1 (<2 mm perforation), grade 2 (2-4 mm perforation), and grade 3(>4 mm perforation). Anterior perforations were classified into grade 0 (no violation), grade 1 (<4 mm perforation), grade 2 (4-6 mm perforation), and grade 3(>6 mm perforation). Grade 2 and grade 3 perforation were considered as "critical" perforation. In total, 1002 percutaneous pedicle screws from 128 patients were analyzed. The mean age was 52.7 ± 16.6. There were 70 male patients and 58 female patients. The total perforation rate was 11.3% (113) with 8.4% (84) grade 1, 2.6% (26) grade 2, and 0.3% (3) grade 3 perforations. The overall "critical" perforation rate was 2.9% (29 screws) and no complications were noted. The highest perforation rates were at T4 (21.6%), T2 (19.4%), and T6 (19.2%). The total perforation rate of 11.3% with the total "critical" perforation rate of 2.9% (2.6% grade 2 and 0.3% grade 3 perforations). The highest perforation rates were found over the upper to mid-thoracic region. Fluoroscopic-guided percutaneous pedicle screws insertion among Asians has the safety and accuracy comparable to the current reported percutaneous pedicle screws and open pedicle screws techniques.

A High-Resolution Study of Hippocampal and Medial Temporal Lobe Correlates of Spatial Context and Prospective Overlapping Route Memory

PubMed Central

Brown, Thackery I.; Hasselmo, Michael E.; Stern, Chantal E.

2015-01-01

When navigating our world we often first plan or retrieve an ideal route to our goal, avoiding alternative paths that lead to other destinations. The medial temporal lobe (MTL) has been implicated in processing contextual information, sequence memory, and uniquely retrieving routes that overlap or “cross paths.” However, the identity of subregions of the hippocampus and neighboring cortex that support these functions in humans remains unclear. The present study used high-resolution functional magnetic resonance imaging (hr-fMRI) in humans to test whether the CA3/DG hippocampal subfield and para-hippocampal cortex are important for processing spatial context and route retrieval, and whether the CA1 subfield facilitates prospective planning of mazes that must be distinguished from alternative overlapping routes. During hr-fMRI scanning, participants navigated virtual mazes that were well-learned from prior training while also learning new mazes. Some routes learned during scanning shared hallways with those learned during pre-scan training, requiring participants to select between alternative paths. Critically, each maze began with a distinct spatial contextual Cue period. Our analysis targeted activity from the Cue period, during which participants identified the current navigational episode, facilitating retrieval of upcoming route components and distinguishing mazes that overlap. Results demonstrated that multiple MTL regions were predominantly active for the contextual Cue period of the task, with specific regions of CA3/DG, parahippocampal cortex, and perirhinal cortex being consistently recruited across trials for Cue periods of both novel and familiar mazes. During early trials of the task, both CA3/DG and CA1 were more active for overlapping than non-overlapping Cue periods. Trial-by-trial Cue period responses in CA1 tracked subsequent overlapping maze performance across runs. Together, our findings provide novel insight into the contributions of MTL subfields to processing spatial context and route retrieval, and support a prominent role for CA1 in distinguishing overlapping episodes during navigational “look-ahead” periods. PMID:24659134

Confinement of a β-barrel protein in nanoperforated free-standing nanomembranes for ion transport.

PubMed

Puiggalí-Jou, Anna; Pérez-Madrigal, Maria M; Del Valle, Luis J; Armelin, Elaine; Casas, María T; Michaux, Catherine; Perpète, Eric A; Estrany, Francesc; Alemán, Carlos

2016-09-29

Bioinspired free-standing nanomembranes (FSNMs) for selective ion transport have been tailored by immobilizing the Omp2a β-barrel membrane protein inside nanoperforations created in flexible poly(lactic acid) (PLA) nanomembranes. Perforated PLA FSNMs have been prepared by spin-coating a 99 : 1 PLA : poly(vinyl alcohol) mixture, and through a phase segregation process nanofeatures with dimensions similar to the entire nanomembrane thickness (∼110 nm) were induced. These nanofeatures have subsequently been transformed into nanoperforations (diameter: ∼51 nm) by selective solvent etching. The protein confined inside the nanopores of PLA FSNMs preserves the β-barrel structure and organizes in ovoid aggregates. The transport properties of Na + , K + , and Ca 2+ across non-perforated PLA, nanoperforated PLA, and Omp2a-filled nanoperforated PLA have been monitored by measuring the nanomembrane resistance with electrochemical impedance spectroscopy (EIS). The incorporation of nanoperforations enhances the transport of ions across PLA nanomembranes, whereas the functionality of immobilized Omp2a is essential to exhibit effects similar to those observed in biological nanomembranes. Indeed, Omp2a-filled nanoperforated PLA nanomembranes exhibit stronger affinity towards Na + and Ca 2+ ions than towards K + . In summary, this work provides a novel bioinspired strategy to develop mechanically stable and flexible FSNMs with channels for ion transport, which are precisely located inside artificial nanoperforations, thus holding great potential for applications in biofiltration and biosensing.

Synaptic Activation of Ribosomal Protein S6 Phosphorylation Occurs Locally in Activated Dendritic Domains

ERIC Educational Resources Information Center

Pirbhoy, Patricia Salgado; Farris, Shannon; Steward, Oswald

2016-01-01

Previous studies have shown that induction of long-term potentiation (LTP) induces phosphorylation of ribosomal protein S6 (rpS6) in postsynaptic neurons, but the functional significance of rpS6 phosphorylation is poorly understood. Here, we show that synaptic stimulation that induces perforant path LTP triggers phosphorylation of rpS6 (p-rpS6)…

A Million-Plus Neuron Model of the Hippocampal Dentate Gyrus: Critical Role for Topography in Determining Spatiotemporal Network Dynamics.

PubMed

Hendrickson, Phillip J; Yu, Gene J; Song, Dong; Berger, Theodore W

2016-01-01

This paper describes a million-plus granule cell compartmental model of the rat hippocampal dentate gyrus, including excitatory, perforant path input from the entorhinal cortex, and feedforward and feedback inhibitory input from dentate interneurons. The model includes experimentally determined morphological and biophysical properties of granule cells, together with glutamatergic AMPA-like EPSP and GABAergic GABAA-like IPSP synaptic excitatory and inhibitory inputs, respectively. Each granule cell was composed of approximately 200 compartments having passive and active conductances distributed throughout the somatic and dendritic regions. Modeling excitatory input from the entorhinal cortex was guided by axonal transport studies documenting the topographical organization of projections from subregions of the medial and lateral entorhinal cortex, plus other important details of the distribution of glutamatergic inputs to the dentate gyrus. Information contained within previously published maps of this major hippocampal afferent were systematically converted to scales that allowed the topographical distribution and relative synaptic densities of perforant path inputs to be quantitatively estimated for inclusion in the current model. Results showed that when medial and lateral entorhinal cortical neurons maintained Poisson random firing, dentate granule cells expressed, throughout the million-cell network, a robust nonrandom pattern of spiking best described as a spatiotemporal "clustering." To identify the network property or properties responsible for generating such firing "clusters," we progressively eliminated from the model key mechanisms, such as feedforward and feedback inhibition, intrinsic membrane properties underlying rhythmic burst firing, and/or topographical organization of entorhinal afferents. Findings conclusively identified topographical organization of inputs as the key element responsible for generating a spatiotemporal distribution of clustered firing. These results uncover a functional organization of perforant path afferents to the dentate gyrus not previously recognized: topography-dependent clusters of granule cell activity as "functional units" or "channels" that organize the processing of entorhinal signals. This modeling study also reveals for the first time how a global signal processing feature of a neural network can evolve from one of its underlying structural characteristics.

A Million-Plus Neuron Model of the Hippocampal Dentate Gyrus: Critical Role for Topography in Determining Spatio-Temporal Network Dynamics

PubMed Central

Hendrickson, Phillip J.; Yu, Gene J.; Song, Dong; Berger, Theodore W.

2016-01-01

Goal This manuscript describes a million-plus granule cell compartmental model of the rat hippocampal dentate gyrus, including excitatory, perforant path input from the entorhinal cortex, and feedforward and feedback inhibitory input from dentate interneurons. Methods The model includes experimentally determined morphological and biophysical properties of granule cells, together with glutamatergic AMPA-like EPSP and GABAergic GABAA-like IPSP synaptic excitatory and inhibitory inputs, respectively. Each granule cell was composed of approximately 200 compartments having passive and active conductances distributed throughout the somatic and dendritic regions. Modeling excitatory input from the entorhinal cortex was guided by axonal transport studies documenting the topographical organization of projections from subregions of the medial and lateral entorhinal cortex, plus other important details of the distribution of glutamatergic inputs to the dentate gyrus. Information contained within previously published maps of this major hippocampal afferent were systematically converted to scales that allowed the topographical distribution and relative synaptic densities of perforant path inputs to be quantitatively estimated for inclusion in the current model. Results Results showed that when medial and lateral entorhinal cortical neurons maintained Poisson random firing, dentate granule cells expressed, throughout the million-cell network, a robust, non-random pattern of spiking best described as spatio-temporal “clustering”. To identify the network property or properties responsible for generating such firing “clusters”, we progressively eliminated from the model key mechanisms such as feedforward and feedback inhibition, intrinsic membrane properties underlying rhythmic burst firing, and/or topographical organization of entorhinal afferents. Conclusion Findings conclusively identified topographical organization of inputs as the key element responsible for generating a spatio-temporal distribution of clustered firing. These results uncover a functional organization of perforant path afferents to the dentate gyrus not previously recognized: topography-dependent clusters of granule cell activity as “functional units” or “channels” that organize the processing of entorhinal signals. This modeling study also reveals for the first time how a global signal processing feature of a neural network can evolve from one of its underlying structural characteristics. PMID:26087482

Insufficient Lymph Node Sampling in Patients with Colorectal Cancer Perforation is Associated with an Adverse Oncological Outcome.

PubMed

Sugawara, Kotaro; Kawaguchi, Yoshikuni; Nomura, Yukihiro; Koike, Daisuke; Nagai, Motoki; Tanaka, Nobutaka

2017-01-01

The impact of lymph node (LN) dissection on long-term outcomes for patients with colorectal cancer (CRC) perforation remains unclear. We aim to investigate factors associated with poor prognosis and recurrence in patients with CRC, with special reference to cancer perforation and LN dissection. The subjects comprised 550 patients who underwent colorectal surgery for CRC at Stage II or III (TNM classification) between February 2006 and November 2013. Short- and long-term outcomes of patients with or without CRC perforation were evaluated. We also sought risk factors on poor prognosis, focusing on LN dissection in patients with CRC perforation. A total of 508 underwent surgery for CRC without perforation (the non-perforation group) and 39 for CRC with perforation (the perforation group). Both overall survival and recurrence-free survival rates were significantly lower in the perforation group than in the non-perforation group (overall survival, P = 0.009; recurrence-free survival, P < 0.001). The relapse rates at the peritoneum (P = 0.002), lung (P = 0.007) and LNs (P = 0.021) were significantly higher in the perforation group than in the non-perforation group. Multivariable Cox proportional hazards model revealed that CRC perforation (hazard ratio [HR] 2.55, 95 % confidential interval [CI] 1.16-4.98, P = 0.022), LN dissection <12 (HR 1.83, 95 % CI 1.07-3.13, P = 0.027), and Stage III (HR 1.79, 95 % CI 1.06-3.08, P = 0.031) were significant and independent risk factors for poor prognosis. Conducting <12 LN dissections independently increased the risk of reduction in overall survival for patients with CRC perforation. Thus, radical LN dissections should be performed to improve patients' survival rates, when patients' general and surgical conditions allow.

Virtual animation of victim-specific 3D models obtained from CT scans for forensic reconstructions: Living and dead subjects.

PubMed

Villa, C; Olsen, K B; Hansen, S H

2017-09-01

Post-mortem CT scanning (PMCT) has been introduced at several forensic medical institutions many years ago and has proved to be a useful tool. 3D models of bones, skin, internal organs and bullet paths can rapidly be generated using post-processing software. These 3D models reflect the individual physiognomics and can be used to create whole-body 3D virtual animations. In such way, virtual reconstructions of the probable ante-mortem postures of victims can be constructed and contribute to understand the sequence of events. This procedure is demonstrated in two victims of gunshot injuries. Case #1 was a man showing three perforating gunshot wounds, who died due to the injuries of the incident. Whole-body PMCT was performed and 3D reconstructions of bones, relevant internal organs and bullet paths were generated. Using 3ds Max software and a human anatomy 3D model, a virtual animated body was built and probable ante-mortem postures visualized. Case #2 was a man presenting three perforating gunshot wounds, who survived the incident: one in the left arm and two in the thorax. Only CT scans of the thorax, abdomen and the injured arm were provided by the hospital. Therefore, a whole-body 3D model reflecting the anatomical proportions of the patient was made combining the actual bones of the victim with those obtained from the human anatomy 3D model. The resulted 3D model was used for the animation process. Several probable postures were also visualized in this case. It has be shown that in Case #1 the lesions and the bullet path were not consistent with an upright standing position; instead, the victim was slightly bent forward, i.e. he was sitting or running when he was shot. In Case #2, one of the bullets could have passed through the arm and continued into the thorax. In conclusion, specialized 3D modelling and animation techniques allow for the reconstruction of ante-mortem postures based on both PMCT and clinical CT. Copyright © 2017 Elsevier B.V. All rights reserved.

[Clinical and microbiological characteristics of complicated intra-abdominal infection in Colombia: a multicenter study].

PubMed

Vallejo, Marta; Cuesta, Diana P; Flórez, Luz E; Correa, Adriana; Llanos, Carmen E; Isaza, Berenice; Vanegas, Stella; Osorio, Johanna; Casanova, Lucía; Villegas, María V

2016-06-01

Complicated community-acquired intra-abdominal infections (CA-cIAI) are a common cause of acute abdomen. To identify the clinical and microbiology profile of CA-cIAI in four Colombian hospitals. This is a prospective, descriptive study, between 08-2012 and 09-2014, including patients with CA-cIAI > 15 years. Data collected included: socio-demographic, clinical, diagnosis, and isolates of the first culture obtained aseptically during surgery with antimicrobial susceptibility. 192 patients were included, 62% men, median age 47.3 years. Co-morbidities were present in 38.4%, 13% had been hospitalized in the previous year 13%, and 9.4% had received antibiotics in the last 6 months; 44.3% were admitted for appendicitis, 17.7% for peritonitis and 16.7% for bowel perforation. CA-cIAI were assessed as moderate in 64.1% of the cases and were treated with ampicillin/sulbactam (SAM) and ertapenem. In 70.8% of cases a bacteria was isolated: 65.1% were gramnegative rods (80.0% Escherichia coli, 44.8% of them susceptible to pipercillin/tazobactam, 65.7% to SAM; 11.2 % were K.pneumoniae, 85% was susceptible for SAM; 16.7% were grampositive cocci (28.1% Streptococci viridans group). The median hospital stay was 7 days and 15.1% died. E. coli, K. pneumoniae and S. viridans were the main organisms to consider in an empiric therapy for CA-cIAI and it is important to know the local epidemiology in order to choose the right antibiotic.

[Microsurgical anatomy of the perforating arteries in the superior space of the internal carotid artery through a pterional approach].

PubMed

Qi, Song-tao; Huang, Chuan-ping; Lu, Yun-tao; Pan, Jun; Fan, Jun

2007-05-01

To study the microanatomy of the perforating arteries in the superior space of the internal carotid artery visualized through a pterional approach. Twelve (24 sides) perfused cadaver heads were dissected via the pterional approach, and the perforating arteries in the superior space of the internal carotid artery were studied under microscope. The diameter, course and distribution in the anterior perforated substance of the perforating arteries were recorded. All the perforating arteries exposed lied on the side of the brain tissue. The carotid bifurcation on 8 sides had perforating arteries, and 11 sides showed medial lenticulostriate artery of the middle cerebral arteries, with short course and overlapped with another perforating arteries upon entry into the anterior perforated substance. On 4 sides, the medial lenticulostriate artery coincided with the perforating arteries in A1. All 24 sides showed middle lenticulostriate artery and lateral lenticulostriate artery of the middle cerebral arteries. Most of the lenticulostriate arteries originated from the anterior segment of the bifurcation of the middle cerebral arteries. The earlier bifurcation occurred in M1 of the middle cerebral arteries, the more perforating arteries originated. On 22 sides, the anterior cerebral arteries had perforating arteries with many branches, and fewer perforating arteries in a main artery were associated with greater diameter of them. The superior space of the internal carotid artery allows a space for operation, and in some cases, part of the medial leticulostriate arteries and A1 perforating arteries can be severed to obtain larger space for the operation.

A Five-Year Review of Perforated Peptic Ulcer Disease in Irrua, Nigeria.

PubMed

Dongo, A E; Uhunmwagho, O; Kesieme, E B; Eluehike, S U; Alufohai, E F

2017-01-01

Peptic ulcer perforation is a common cause of emergency admission and surgery. This is the first study that documents the presentation and outcome of management in Irrua, Nigeria. This is a prospective study of all patients operated on for perforated peptic ulcer between April 1, 2010, and March 31, 2015. A structured questionnaire containing patients' demographics, operation findings, and outcome was filled upon discharge or death. There were 104 patients. 81 males and 23 females (M : F = 3.5 : 1). The age range was between 17 years and 95 years. The mean age was 48.99 years ± SD 16.1 years. The ratio of gastric to duodenal perforation was 1.88 : 1. Perforation was the first sign of peptic ulcer disease in 62 (59.6%). Pneumoperitoneum was detectable with plain radiographs in 95 (91%) patients. 72 (69.2%) had Graham's Omentopexy. Death rate was 17.3%. We note that gastric perforation is a far commoner disease in our environment. Perforation is often the first sign of peptic ulcer disease. We identify fasting amongst Christians as a risk factor for perforation.

KV7 Channel Pharmacological Activation by the Novel Activator ML213: Role for Heteromeric KV7.4/KV7.5 Channels in Guinea Pig Detrusor Smooth Muscle Function.

PubMed

Provence, Aaron; Angoli, Damiano; Petkov, Georgi V

2018-01-01

Voltage-gated K V 7 channels (K V 7.1 to K V 7.5) are important regulators of the cell membrane potential in detrusor smooth muscle (DSM) of the urinary bladder. This study sought to further the current knowledge of K V 7 channel function at the molecular, cellular, and tissue levels in combination with pharmacological tools. We used isometric DSM tension recordings, ratiometric fluorescence Ca 2+ imaging, amphotericin-B perforated patch-clamp electrophysiology, and in situ proximity ligation assay (PLA) in combination with the novel compound N -(2,4,6-trimethylphenyl)-bicyclo[2.2.1]heptane-2-carboxamide (ML213), an activator of K V 7.2, K V 7.4, and K V 7.5 channels, to examine their physiologic roles in guinea pig DSM function. ML213 caused a concentration-dependent (0.1-30 µ M) inhibition of spontaneous phasic contractions in DSM isolated strips; effects blocked by the K V 7 channel inhibitor XE991 (10 µ M). ML213 (0.1-30 µ M) also reduced pharmacologically induced and nerve-evoked contractions in DSM strips. Consistently, ML213 (10 µ M) decreased global intracellular Ca 2+ concentrations in Fura-2-loaded DSM isolated strips. Perforated patch-clamp electrophysiology revealed that ML213 (10 µ M) caused an increase in the amplitude of whole-cell K V 7 currents. Further, in current-clamp mode of the perforated patch clamp, ML213 hyperpolarized DSM cell membrane potential in a manner reversible by washout or XE991 (10 µ M), consistent with ML213 activation of K V 7 channel currents. Preapplication of XE991 (10 µ M) not only depolarized the DSM cells, but also blocked ML213-induced hyperpolarization, confirming ML213 selectivity for K V 7 channel subtypes. In situ PLA revealed colocalization and expression of heteromeric K V 7.4/K V 7.5 channels in DSM isolated cells. These combined results suggest that ML213-sensitive K V 7.4- and K V 7.5-containing channels are essential regulators of DSM excitability and contractility. Copyright © 2017 by The American Society for Pharmacology and Experimental Therapeutics.

Hormonal Regulation of Extinction: Implication for Mechanisms of Gender Difference in PTSD

DTIC Science & Technology

2009-09-01

role of gonadal hormones in the regulation of Pavlovian fear conditioning and its extinction. Pavlovian fear conditioning and its extinction serve...learning in Pavlovian fear conditioning involves training with the presentation of an innocuous stimulus (the conditioned stimulus – CS) that is associated...GD, Schlinger BA, Fanselow MS (1998) Testicular hormones do not regulate sexually dimorphic Pavlovian fear conditioning or perforant- path long-term

Glove perforation rate in open lung surgery.

PubMed

Hollaus, P H; Lax, F; Janakiev, D; Wurnig, P N; Pridun, N S

1999-04-01

In open lung surgery the surgical access is encircled by the ribs, which should result in a high glove perforation rate compared with other surgical specialities. Prospectively the surgeon, first and second assistant and the scrub nurse wore double standard latex gloves during 100 thoracotomies. Parameters recorded were: procedure performed, number of perforations, localization of perforation, the seniority of the surgeon, manoeuvre performed at the moment of perforation, immediate cause of perforation, operation time, performance of rib resection during thoracotomy and time of occurrence of the first three perforations. One thousand, six hundred and seventy-three gloves (902 outer, 771 inner) were tested. In 78 operations perforations occurred. There were 150 outer glove perforations (8.9%, 0-8, mean 1.23), 19 inner glove perforations (1.13%, 0-2, mean 0.19). Cutaneous blood exposure was prevented in 78% of all operations and in 87% of all perforations. The perforation rate for the surgeon, the scrub nurse, the first and the second assistant were 61.2, 40.4, 9.7 and 3.1% of all operations, respectively. Rib resection and a duration of more than 2 h resulted in a significant rise of glove perforation rate (P<0.05). The personal experience of the surgeon and the type of operation did not correlate with glove perforation. The immediate cause leading to perforation was named in only 17 cases (13.7%) and comprised contact with bone (seven), a needle stitch (seven) and a production flaw (three). Leaks were localized mostly on the first finger (18%),second finger, (39%) palm and dorsum of the hand (16%). The average occurrence of all first perforations was 38.7 min (range 3-190) after the beginning of surgery, the second after 63.2 min (range 10-195). Fifty-four first perforations (50.5%) were found during the first 30 min of the operation. The reported perforation rate of 78% lies in the highest range of reported perforation rates in different surgical specialities. Double gloving effectively prevented cutaneous blood exposure and thus should become a routine for the thoracic surgeon to prevent transmission of infectious diseases from the patient to the surgeon.

Changes in Search Path Complexity and Length During Learning of a Virtual Water Maze: Age Differences and Differential Associations with Hippocampal Subfield Volumes

PubMed Central

Daugherty, Ana M.; Bender, Andrew R.; Yuan, Peng; Raz, Naftali

2016-01-01

Impairment of hippocampus-dependent cognitive processes has been proposed to underlie age-related deficits in navigation. Animal studies suggest a differential role of hippocampal subfields in various aspects of navigation, but that hypothesis has not been tested in humans. In this study, we examined the association between volume of hippocampal subfields and age differences in virtual spatial navigation. In a sample of 65 healthy adults (age 19–75 years), advanced age was associated with a slower rate of improvement operationalized as shortening of the search path over 25 learning trials on a virtual Morris water maze task. The deficits were partially explained by greater complexity of older adults' search paths. Larger subiculum and entorhinal cortex volumes were associated with a faster decrease in search path complexity, which in turn explained faster shortening of search distance. Larger Cornu Ammonis (CA)1–2 volume was associated with faster distance shortening, but not in path complexity reduction. Age differences in regional volumes collectively accounted for 23% of the age-related variance in navigation learning. Independent of subfield volumes, advanced age was associated with poorer performance across all trials, even after reaching the asymptote. Thus, subiculum and CA1–2 volumes were associated with speed of acquisition, but not magnitude of gains in virtual maze navigation. PMID:25838036

Getting off the Bain path: Are there any metastable states of cubic elements?

NASA Astrophysics Data System (ADS)

Mehl, Michael J.; Boyer, Larry L.

2003-03-01

Body-centered and face-centered cubic crystals can be considered as special cases of a body-centered tetragonal crystal with c/a = 1 and 2, respectively. First-principles calculations along this Bain path show that elements with an fcc (bcc) ground state are elastically unstable with respect to a tetragonal distortion in the bcc (fcc) phase. Starting with a normally fcc element and calculating E(c/a) for c/a < 1 we find a local minimum near c/a = 2/3, while for a bcc element we find a local minimum at some c/a > 2. It is tempting to conclude that these bct minima, which are required by continuity, are metastable, but calculations by several authors show that, at least for Al, Cu, and Pd, the bct structures are unstable with respect to an orthorhombic distortion. We use a simple "magic strain" construction(L. L. Boyer, Acta Cryst. A) 45, FC29 (1989).(M. J. Mehl and L. L. Boyer, Phys. Rev. B) 43, 9498 (1991). to study the stability of these bct states, and present examples which suggest that no fcc or bcc element has a metastable bct state.

Dopamine receptor activity participates in hippocampal synaptic plasticity associated with novel object recognition.

PubMed

Yang, Kechun; Broussard, John I; Levine, Amber T; Jenson, Daniel; Arenkiel, Benjamin R; Dani, John A

2017-01-01

Physiological and behavioral evidence supports that dopamine (DA) receptor signaling influences hippocampal function. While several recent studies examined how DA influences CA1 plasticity and learning, there are fewer studies investigating the influence of DA signaling to the dentate gyrus. The dentate gyrus receives convergent cortical input through the perforant path fiber tracts and has been conceptualized to detect novelty in spatial memory tasks. To test whether DA-receptor activity influences novelty-detection, we used a novel object recognition (NOR) task where mice remember previously presented objects as an indication of learning. Although DA innervation arises from other sources and the main DA signaling may be from those sources, our molecular approaches verified that midbrain dopaminergic fibers also sparsely innervate the dentate gyrus. During the NOR task, wild-type mice spent significantly more time investigating novel objects rather than previously observed objects. Dentate granule cells in slices cut from those mice showed an increased AMPA/NMDA-receptor current ratio indicative of potentiated synaptic transmission. Post-training injection of a D1-like receptor antagonist not only effectively blocked the preference for the novel objects, but also prevented the increased AMPA/NMDA ratio. Consistent with that finding, neither NOR learning nor the increase in the AMPA/NMDA ratio were observed in DA-receptor KO mice under the same experimental conditions. The results indicate that DA-receptor signaling contributes to the successful completion of the NOR task and to the associated synaptic plasticity of the dentate gyrus that likely contributes to the learning. © 2016 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

Perforating arteries originating from the posterior communicating artery: a 7.0-Tesla MRI study.

PubMed

Conijn, Mandy M A; Hendrikse, Jeroen; Zwanenburg, Jaco J M; Takahara, Taro; Geerlings, Mirjam I; Mali, Willem P Th M; Luijten, Peter R

2009-12-01

The aim of this study was to investigate the ability of time-of-flight (TOF) magnetic resonance (MR) angiography at 7.0 Tesla to show the perforating branches of the posterior communicating artery (PCoA), and to investigate the presence of such visible perforating branches in relation to the size of the feeding PCoA. The secondary aim was to visualise and describe the anterior choroidal artery and the perforating branches of the P1-segment of posterior cerebral artery (P1). Forty-six healthy volunteers underwent TOF MR angiography at 7.0 Tesla. With 7.0-Tesla imaging, we visualised for the first time perforating arteries originating from the PCoA in vivo without the use of contrast agents. A perforating artery from the PCoA was found in a large proportion of the PCoAs (64%). The presence was associated with a larger diameter of the underlying PCoA (1.23 versus 1.06 mm, P = 0.03). The anterior choroidal artery was visible bilaterally in all participants. In 83% of all P1s, one or two perforating branches were visible. Non-invasive assessment of the perforating arteries of the PCoA together with the anterior choroidal artery and the perforating arteries of the P1 may increase our understanding of infarcts in the deep brain structures supplied by these arteries.

A Five-Year Review of Perforated Peptic Ulcer Disease in Irrua, Nigeria

PubMed Central

Uhunmwagho, O.; Eluehike, S. U.; Alufohai, E. F.

2017-01-01

Background Peptic ulcer perforation is a common cause of emergency admission and surgery. This is the first study that documents the presentation and outcome of management in Irrua, Nigeria. Patients and Method This is a prospective study of all patients operated on for perforated peptic ulcer between April 1, 2010, and March 31, 2015. A structured questionnaire containing patients' demographics, operation findings, and outcome was filled upon discharge or death. Results There were 104 patients. 81 males and 23 females (M : F = 3.5 : 1). The age range was between 17 years and 95 years. The mean age was 48.99 years ± SD 16.1 years. The ratio of gastric to duodenal perforation was 1.88 : 1. Perforation was the first sign of peptic ulcer disease in 62 (59.6%). Pneumoperitoneum was detectable with plain radiographs in 95 (91%) patients. 72 (69.2%) had Graham's Omentopexy. Death rate was 17.3%. Conclusion We note that gastric perforation is a far commoner disease in our environment. Perforation is often the first sign of peptic ulcer disease. We identify fasting amongst Christians as a risk factor for perforation. PMID:28656171

Delta neutrophil index: A reliable marker to differentiate perforated appendicitis from non-perforated appendicitis in the elderly.

PubMed

Shin, Dong Hyuk; Cho, Young Suk; Kim, Yoon Sung; Ahn, Hee Cheol; Oh, Young Taeck; Park, Sang O; Won, Moo-Ho; Cho, Jun Hwi; Kim, Young Myeong; Seo, Jeong Yeol; Lee, Young Hwan

2018-01-01

Delta neutrophil index (DNI) is a new inflammatory marker and the present study aimed to evaluate the predictive value of the DNI for the presence of a perforation in elderly with acute appendicitis. This retrospective observational study was conducted on 108 consecutive elderly patients (≥65 years old) with acute appendicitis treated over a 24-month period. Sixty-nine of the 108 patients (median, IQR: 72, 67-77 years) were allocated to the perforated appendicitis group (63.9%) and 39 to the non-perforated appendicitis group (36.1%). WBC, neutrophil-to-lymphocyte ratio, platelet-to-lymphocyte ratio and DNI were significantly higher in the perforated group. In multiple logistic regression analyses, initial DNI was the only independent marker that can significantly predict the presence of perforation in multiple regression [odds ratio 9.38, 95% confidence interval (2.51-35.00), P=.001]. Receiver operator characteristic curve analysis showed that DNI is a good predictor for the presence of appendiceal perforation at an optimal cut-off for DNI being 1.4% (sensitivity 67.7%, specificity 90.0%, AUC 0.807). Clinicians can reliably differentiate acute perforated appendicitis from non-perforated appendicitis by DNI level of 1.4 or more in elderly patients. © 2017 Wiley Periodicals, Inc.

[Morphological reasoning of the resected tissue volume by the perforated ulcer of the duodenum].

PubMed

Vachev, A N; Kozlov, A A; Sukhachev, P A; Dergal', S V; Larina, T V

2011-01-01

102 tissue samples, resected during treatment of the perforated duodenal ulcers. The most pronounced fibroplastic and acute inflammatory tissue changes were registered in the immediate perforation zone and 0,5 sm above. At a distance of 1,0 sm these changes become less evident. Therefore, in patients with the perforated duodenal ulcer and palpable surrounding infiltrate less than 3,0 sm in diameter, the resection line should be no shorter than 1,0 sm away from the perforation.

Brief Report: Risk of Gastrointestinal Perforation Among Rheumatoid Arthritis Patients Receiving Tofacitinib, Tocilizumab, or Other Biologic Treatments.

PubMed

Xie, Fenglong; Yun, Huifeng; Bernatsky, Sasha; Curtis, Jeffrey R

2016-11-01

To evaluate gastrointestinal (GI) perforation in rheumatoid arthritis (RA) patients receiving tofacitinib, tocilizumab, or other biologic agents. Using health plan data from 2006 through 2014, RA patients without prior GI perforation were identified. Those in whom treatment with tofacitinib or a biologic agent was being initiated were followed up for incident GI perforation with hospitalization. Crude incidence rates were calculated by exposure. Adjusted Cox proportional hazards models were used to evaluate the association between GI perforation and exposures. Hazard ratios (HRs) with 95% confidence intervals (95% CIs) were calculated. A cohort of 167,113 RA patients was analyzed. Among them, 4,755 began treatment with tofacitinib, 11,705 with tocilizumab, 115,047 with a tumor necrosis factor inhibitor (TNFi), 31,214 with abatacept, and 4,392 with rituximab. Compared to TNFi recipients, abatacept recipients were older, tofacitinib and rituximab recipients were younger, and tocilizumab recipients were similar in age. Patients beginning treatment with a non-TNFi agent were more likely to have previously received biologic agents than patients beginning treatment with a TNFi. The incidence of GI perforation per 1,000 patient-years was 0.86 (tofacitinib), 1.55 (tocilizumab), 1.07 (abatacept), 0.73 (rituximab), and 0.83 (TNFi). Most perforations occurred in the lower GI tract: the incidence of lower GI tract perforation per 1,000 patient-years was 0.86 (tofacitinib), 1.26 (tocilizumab), 0.76 (abatacept), 0.48 (rituximab), and 0.46 (TNFi). Lower GI tract perforation risk was significantly elevated with tocilizumab treatment, and numerically elevated with tofacitinib treatment, versus treatment with TNFi. Adjusted HRs were 2.51 (95% CI 1.31-4.80) for tocilizumab and 1.94 (95% CI 0.49-7.65) for tofacitinib. Older age (HR 1.16 per 5 years [95% CI 1.10-1.22]), diverticulitis/other GI conditions (HR 3.25 [95% CI 1.62-6.50]), and prednisone use at >7.5 mg/day (HR 2.29 [95% CI 1.39-3.78]) were associated with lower GI tract perforation. The incidence of upper GI tract perforation was similar among all drug exposures. The risk of lower GI tract perforation associated with tocilizumab treatment, and possibly tofacitinib treatment, is elevated compared to that associated with TNF blockade. © 2016, American College of Rheumatology.

Causes and Outcomes of Esophageal Perforation in Eosinophilic Esophagitis.

PubMed

Runge, Thomas M; Eluri, Swathi; Cotton, Cary C; Burk, Caitlin M; Woosley, John T; Shaheen, Nicholas J; Dellon, Evan S

2017-10-01

To characterize patients who suffer perforation in the context of eosinophilic esophagitis (EoE) and to identify predictors of perforation. Esophageal perforation is a serious complication of EoE. We conducted a retrospective cohort study of the University of North Carolina EoE clinicopathologic database from 2001 to 2014. Subjects were included if they had an incident diagnosis of EoE and met consensus guidelines, including nonresponse to a PPI trial. Patients with EoE who had suffered perforation at any point during their course were identified, and compared with EoE cases without perforation. Multiple logistic regression was performed to determine predictors of perforation. Out of 511 subjects with EoE, 10 (2.0%) had experienced an esophageal perforation. Although those who perforated tended to have a longer duration of symptoms before diagnosis (11.4 vs. 7.0 y, P=0.13), a history of food impaction (odds ratio, 14.9; 95% confidence interval, 1.7-129.2) and the presence of a focal stricture (odds ratio, 4.6; 95% confidence interval, 1.1-19.7) were the only factors independently associated with perforation. Most perforations (80%) occurred after a prolonged food bolus impaction, and only half of individuals (5/10) carried a diagnosis of EoE at the time of perforation; none occurred after dilation. Six patients (60%) were treated with nonoperative management, and 4 (40%) required surgical repair. Esophageal perforation is a rare but serious complication of eosinophilic esophagitis, occurring in ∼2% of cases. Most episodes are due to food bolus impaction or strictures, suggesting that patients with fibrostenotic disease due to longer duration of symptoms are at increased risk.

Reaction of the lateral periodontium of dogs' teeth to contaminated and noncontaminated perforations filled with mineral trioxide aggregate.

PubMed

Holland, Roberto; Bisco Ferreira, Luciana; de Souza, Valdir; Otoboni Filho, José Arlindo; Murata, Sueli Satomi; Dezan, Eloi

2007-10-01

It has been shown that the mineral trioxide aggregate (MTA) used to seal lateral/furcal perforations stimulates the deposition of newly formed cementum. Nevertheless, when the site of the perforation is contaminated, the healing process might occur under less favorable conditions. This study evaluated the repair healing process of noncontaminated and contaminated lateral perforations filled with MTA and the effect of previously filling the contaminated perforations with a bactericidal agent. Thirty lateral root perforations were prepared in endodontically treated dog's teeth, thus forming 3 groups with 10 specimens each. In group 1 the perforations were immediately sealed with MTA. In group 2 the perforations were left open for 7 days and thereafter sealed with MTA. In group 3 the perforations were left open for 7 days, filled temporarily with a calcium hydroxide-based paste for 14 days, and then sealed with MTA. The animals were killed after 90 days, and the pieces were prepared for histomorphologic and histomicrobiologic evaluations. The statistical analysis showed that group 1 had significantly better repair than groups 2 (P < .05) and 3 (P < .05), which validates the superior results obtained when MTA was immediately used to seal root perforations. Groups 2 and 3 had statistically similar repair to each other (P > .05). There were a larger number of cases of complete or partial biologic seal in group 1 compared with the contaminated groups. It might be concluded that the lateral root perforations sealed with MTA after contamination presented worse repair than the noncontaminated, immediately sealed perforations. The temporary filling with a bactericidal agent (calcium hydroxide-based paste) did not improve the repair of perforations exposed to contamination, and the contaminated groups presented similar results to each other.

Pathological changes in hippocampal neuronal circuits underlie age-associated neurodegeneration and memory loss: positive clue toward SAD.

PubMed

Moorthi, P; Premkumar, P; Priyanka, R; Jayachandran, K S; Anusuyadevi, M

2015-08-20

Among vertebrates hippocampus forms the major component of the brain in consolidating information from short-term memory to long-term memory. Aging is considered as the major risk factor for memory impairment in sporadic Alzheimer's disease (SAD) like pathology. Present study thus aims at investigating whether age-specific degeneration of neuronal-circuits in hippocampal formation (neural-layout of Subiculum-hippocampus proper-dentate gyrus (DG)-entorhinal cortex (EC)) results in cognitive impairment. Furthermore, the neuroprotective effect of Resveratrol (RSV) was attempted to study in the formation of hippocampal neuronal-circuits. Radial-Arm-Maze was conducted to evaluate hippocampal-dependent spatial and learning memory in control and experimental rats. Nissl staining of frontal cortex (FC), subiculum, hippocampal-proper (CA1→CA2→CA3→CA4), DG, amygdala, cerebellum, thalamus, hypothalamus, layers of temporal and parietal lobe of the neocortex were examined for pathological changes in young and aged wistar rats, with and without RSV. Hippocampal trisynaptic circuit (EC layerII→DG→CA3→CA1) forming new memory and monosynaptic circuit (EC→CA1) that strengthen old memories were found disturbed in aged rats. Loss of Granular neuron observed in DG and polymorphic cells of CA4 can lead to decreased mossy fibers disturbing neural-transmission (CA4→CA3) in perforant pathway. Further, intensity of nissl granules (stratum lacunosum moleculare (SLM)-SR-SO) of CA3 pyramidal neurons was decreased, disturbing the communication in schaffer collaterals (CA3-CA1) during aging. We also noticed disarranged neuronal cell layer in Subiculum (presubiculum (PrS)-parasubiculum (PaS)), interfering output from hippocampus to prefrontal cortex (PFC), EC, hypothalamus, and amygdala that may result in interruption of thought processes. We conclude from our observations that poor memory performance of aged rats as evidenced through radial arm maze (RAM) analysis was due to the defect in neuronal-circuits of hippocampus (DG-CA4-CA1-Sub) that were significantly damaged leading to memory impairment. Interestingly, RSV was observed to culminate pathological events in the hippocampal neuronal circuit during aging, proving them as potent therapeutic drug against age-associated neurodegeneration and memory loss. Copyright © 2015 IBRO. Published by Elsevier Ltd. All rights reserved.

Harvest maturity, pre-cutting wash and post-processing dip to improve quality of fresh-cut carambola fruit

USDA-ARS?s Scientific Manuscript database

‘Arkin’ carambola (Averrhoa carambola L.) fruit harvested at color break or full yellow stage were washed with or without an alkaline solution (pH 12), cut to 10 mm slices, dipped in calcium ascorbate (Ca ASA), ascorbic acid (ASA) or water, and packaged in perforated clamshells for up to 14 days sto...

Thermal properties and cycling performance of Ca(BH4)2/MgH2 composite for energy storage

NASA Astrophysics Data System (ADS)

Li, Yang; Li, Ping; Tan, Qiwei; Zhang, Zongliang; Wan, Qi; Liu, Zhiwei; Subramanian, Arunprabaharan; Qu, Xuanhui

2018-05-01

Here we report the thermal properties and cycling performance of Ca(BH4)2/MgH2. The reaction enthalpy is 48 kJ mol-1 H2 and equilibrium pressure at 350 °C is 0.4981 MPa. We add NbF5 into Ca(BH4)2/MgH2to figure out the degradation mechanism because of its catalytic ability. Ca(BH4)2/MgH2 follows the dehydrogenation path to form CaH2, CaB6 and Mg. The degradation of Ca(BH4)2/MgH2 composite during cycling is due to the particle aggregation and the reduction of CaB6 product. NbF5 can promote the forming of CaB6 and prevent microstructural coarsening in Ca(BH4)2/MgH2 during cycling, which leads to better reversibility.

Neurogenesis and pattern separation: time for a divorce.

PubMed

Becker, Suzanna

2017-05-01

The generation of new neurons in the adult mammalian brain has led to numerous theories as to their functional significance. One of the most widely held views is that adult neurogenesis promotes pattern separation, a process by which overlapping patterns of neural activation are mapped to less overlapping representations. While a large body of evidence supports a role for neurogenesis in high interference memory tasks, it does not support the proposed function of neurogenesis in mediating pattern separation. Instead, the adult-generated neurons seem to generate highly overlapping and yet distinct distributed representations for similar events. One way in which these immature, highly plastic, hyperactive neurons may contribute to novel memory formation while avoiding interference is by virtue of their extremely sparse connectivity with incoming perforant path fibers. Another intriguing proposal, awaiting empirical confirmation, is that the young neurons' recruitment into memory formation is gated by a novelty/mismatch mechanism mediated by CA3 or hilar back-projections. Ongoing research into the intriguing link between neurogenesis, stress-related mood disorders, and age-related neurodegeneration may lead to promising neurogenesis-based treatments for this wide range of clinical disorders. WIREs Cogn Sci 2017, 8:e1427. doi: 10.1002/wcs.1427 For further resources related to this article, please visit the WIREs website. © 2016 Wiley Periodicals, Inc.

Changes in Search Path Complexity and Length During Learning of a Virtual Water Maze: Age Differences and Differential Associations with Hippocampal Subfield Volumes.

PubMed

Daugherty, Ana M; Bender, Andrew R; Yuan, Peng; Raz, Naftali

2016-06-01

Impairment of hippocampus-dependent cognitive processes has been proposed to underlie age-related deficits in navigation. Animal studies suggest a differential role of hippocampal subfields in various aspects of navigation, but that hypothesis has not been tested in humans. In this study, we examined the association between volume of hippocampal subfields and age differences in virtual spatial navigation. In a sample of 65 healthy adults (age 19-75 years), advanced age was associated with a slower rate of improvement operationalized as shortening of the search path over 25 learning trials on a virtual Morris water maze task. The deficits were partially explained by greater complexity of older adults' search paths. Larger subiculum and entorhinal cortex volumes were associated with a faster decrease in search path complexity, which in turn explained faster shortening of search distance. Larger Cornu Ammonis (CA)1-2 volume was associated with faster distance shortening, but not in path complexity reduction. Age differences in regional volumes collectively accounted for 23% of the age-related variance in navigation learning. Independent of subfield volumes, advanced age was associated with poorer performance across all trials, even after reaching the asymptote. Thus, subiculum and CA1-2 volumes were associated with speed of acquisition, but not magnitude of gains in virtual maze navigation. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Intrauterine devices and risk of uterine perforation: current perspectives

PubMed Central

Rowlands, Sam; Oloto, Emeka; Horwell, David H

2016-01-01

Uterine perforation is an uncommon complication of intrauterine device insertion, with an incidence of one in 1,000 insertions. Perforation may be complete, with the device totally in the abdominal cavity, or partial, with the device to varying degrees within the uterine wall. Some studies show a positive association between lactation and perforation, but a causal relationship has not been established. Very rarely, a device may perforate into bowel or the urinary tract. Perforated intrauterine devices can generally be removed successfully at laparoscopy. PMID:29386934

The effect of perforations on the ballistics of a flare-stabilized projectile

NASA Astrophysics Data System (ADS)

Mermagen, W. H.; Yalamanchili, R. J.

Flight tests of two 35/105 mm flare stabilized projectile configurations were conducted. The projectiles were fired from the M68 tank cannon at Mach 4.0 using a standard M735 sabot. Flight data were obtained with a doppler velocimeter. The perforated flare projectiles showed a reduced drag for M greater than 1.7, which increased significantly at velocities below M 1.7, while the solid flare rounds had a slightly higher drag above Mach 1.7. Below Mach 1.7, the solid flare rounds had less drag than the perforated flare round. Both solid and perforated flare projectiles had a maximum range of less than 8.0 kilometers. The effects of the perforations on the flight performance were small. The flight data are compared to previous tests of the German-made 'LKL' projectile. The differences in flight performance between solid flares, flares with perforations, and the LKL-perforated flare rounds were small and of no practical consequence. Dispersion tests of the solid-flare stabilized projectiles were conducted at one, two, and three kilometers with excellent results. Very low dispersions were observed at all ranges.

Synaptically Driven Phosphorylation of Ribosomal Protein S6 Is Differentially Regulated at Active Synapses versus Dendrites and Cell Bodies by MAPK and PI3K/mTOR Signaling Pathways

ERIC Educational Resources Information Center

Pirbhoy, Patricia Salgado; Farris, Shannon; Steward, Oswald

2017-01-01

High-frequency stimulation of the medial perforant path triggers robust phosphorylation of ribosomal protein S6 (rpS6) in activated dendritic domains and granule cell bodies. Here we dissect the signaling pathways responsible for synaptically driven rpS6 phosphorylation in the dentate gyrus using pharmacological agents to inhibit PI3-kinase/mTOR…

The Lumbar Artery Perforator Flap: 3-Dimensional Anatomical Study and Clinical Applications.

PubMed

Bissell, Mary Beth; Greenspun, David T; Levine, Josh; Rahal, William; Al-Dhamin, Ammar; AlKhawaji, Ali; Morris, Steven F

2016-10-01

The lumbar region is a potential donor site for perforator-based rotational or free flaps or as a recipient site for free flaps to obtain coverage for deficits in the sacral region. Because of the lack of consensus regarding the microvascular anatomy of this potential flap site, a robust investigation of the anatomy of this region is required. Three-dimensional reconstructions (n = 6) of the microvasculature of the lumbar region were generated using MIMICS software (Materialise, Belgium) for each of the four paired lumbar vessels. Diameter, course, and pedicle length were recorded for all lumbar artery (LA) perforators. Statistical analysis was performed using SigmaStat 4.0 and graphs were generated using GraphPad Prism 6 Software. Perforators arising from the first pair of LAs are reliably detected along the inferior margin of the 12th rib, extending inferiorly and laterally from the midline while perforators arising from the fourth pair of LA perforate the fascia along a horizontal plane connecting the posterior iliac crests. There are significantly more cutaneous perforators arising from the first (L1) and fourth (L4) pairs of LA than from the second (L2) and third (L3) (mean ± SD: L1, 5.5 ± 1.2; L2, 1.4 ± 0.7; L3, 1.3 ± 0.7; L4, 4.8 ± 1.0; P < 0.05). The average perforator diameter arising from L1 is greater than those arising from L4 (diameter ± SD: L1, 1.2 mm ± 0.2 >L4, 0.8 mm ± 0.2; P < 0.0001). L1 and L4 perforators have longer pedicle lengths than those arising from L2 and L3 (length ± SD: L1, 98.2 mm ± 57.8; L4, 106.1 mm ± 23.3 >L2, 67.5 mm ± 27.4; L3, 78.5 mm ± 30.3; P < 0.05). Perforators arising from the first and fourth LAs arise in a predictable fashion, have adequate pedicle lengths, and are of suitable diameter to support a perforator flap. We present a case to support the potential use of this flap for microvascular breast reconstruction.

Differentiating perforated from non-perforated appendicitis on contrast-enhanced magnetic resonance imaging.

PubMed

Rosenbaum, Daniel G; Askin, Gulce; Beneck, Debra M; Kovanlikaya, Arzu

2017-10-01

The role of magnetic resonance imaging (MRI) in pediatric appendicitis is increasing; MRI findings predictive of appendiceal perforation have not been specifically evaluated. To assess the performance of MRI in differentiating perforated from non-perforated appendicitis. A retrospective review of pediatric patients undergoing contrast-enhanced MRI and subsequent appendectomy was performed, with surgicopathological confirmation of perforation. Appendiceal diameter and the following 10 MRI findings were assessed: appendiceal restricted diffusion, wall defect, appendicolith, periappendiceal free fluid, remote free fluid, restricted diffusion within free fluid, abscess, peritoneal enhancement, ileocecal wall thickening and ileus. Two-sample t-test and chi-square tests were used to analyze continuous and discrete data, respectively. Sensitivity and specificity for individual MRI findings were calculated and optimal thresholds for measures of accuracy were selected. Seventy-seven patients (mean age: 12.2 years) with appendicitis were included, of whom 22 had perforation. The perforated group had a larger mean appendiceal diameter and mean number of MRI findings than the non-perforated group (12.3 mm vs. 8.6 mm; 5.0 vs. 2.0, respectively). Abscess, wall defect and restricted diffusion within free fluid had the greatest specificity for perforation (1.00, 1.00 and 0.96, respectively) but low sensitivity (0.36, 0.25 and 0.32, respectively). The receiver operator characteristic curve for total number of MRI findings had an area under the curve of 0.92, with an optimal threshold of 3.5. A threshold of any 4 findings had the best ability to accurately discriminate between perforated and non-perforated cases, with a sensitivity of 82% and specificity of 85%. Contrast-enhanced MRI can differentiate perforated from non-perforated appendicitis. The presence of multiple findings increases diagnostic accuracy, with a threshold of any four findings optimally discriminating between perforated and non-perforated cases. These results may help guide management decisions as MRI assumes a greater role in the work-up of pediatric appendicitis.

Functional link between muscarinic receptors and large-conductance Ca2+-activated K+ channels in freshly-isolated human detrusor smooth muscle cells

PubMed Central

Parajuli, Shankar P.; Hristov, Kiril L.; Cheng, Qiuping; Malysz, John; Rovner, Eric S.; Petkov, Georgi V.

2014-01-01

Activation of muscarinic acetylcholine receptors (mAChRs) constitutes the primary mechanism for enhancing excitability and contractility of human detrusor smooth muscle (DSM). Since the large conductance Ca2+-activated K+ (KCa1.1) channels are key regulators of human DSM function, we investigated whether mAChR activation increases human DSM excitability by inhibiting KCa1.1 channels. We used the mAChR agonist, carbachol, to determine the changes in KCa1.1 channel activity upon mAChR activation in freshly-isolated human DSM cells obtained from open bladder surgeries using the perforated whole cell and single KCa1.1 channel patch-clamp recordings. Human DSM cells were collected from 29 patients (23 males and 6 females, average age of 65.9±1.5 years). Carbachol inhibited the amplitude and frequency of KCa1.1 channel-mediated spontaneous transient outward currents and spontaneous transient hyperpolarizations, which are triggered by the release of Ca2+ from ryanodine receptors. Carbachol also caused membrane potential depolarization, which was not observed in the presence of iberiotoxin, a KCa1.1 channel inhibitor, indicating the critical role of the KCa1.1 channels. The potential direct carbachol effects on KCa1.1channels were examined under conditions of removing the major cellular Ca2+ sources for KCa1.1 channel activation with pharmacological inhibitors (thapsigargin, ryanodine, and nifedipine). In the presence of these inhibitors, carbachol did not affect the single KCa1.1 channel open probability and mean KCa1.1 channel conductance (cell-attached configuration) or depolarization-induced whole cell steady-state KCa1.1 currents. The data support the concept that mAChR activation triggers indirect functional KCa1.1 channel inhibition mediated by intracellular Ca2+, thus increasing the excitability in human DSM cells. PMID:24867682

Colonic perforation with peritonitis in amoebiasis: a tropical disease with high mortality.

PubMed

Jain, Bhupendra Kumar; Garg, Pankaj Kumar; Kumar, Anjay; Mishra, Kiran; Mohanty, Debajyoti; Agrawal, Vivek

2013-01-01

Invasive colonic amoebiasis presents primarily with dysentery; colonic perforation occurs rarely. Cases of amoebic colonic perforations have been reported sporadically over the past 20 years. A retrospective study was done in the surgical unit of a tertiary care hospital in North India. The case records of those patients were reviewed who underwent exploratory laparotomy from January 2011 to September 2012 and were diagnosed with amoebic colonic perforation on histopathological examination. Details concerning the clinical presentation, investigations, intraoperative findings, operative procedures, and postoperative outcomes were retrieved. Amongst, a total of 186 emergency exploratory laparotomies carried out during the study, 15 patients of amoebic colonic perforation were identified. The median age of the patients was 42 years (IQR 32.0-58.0) and the male to female ratio was 13:2. Previous history of colitis was present in only 1 patient. The preoperative diagnosis was perforation peritonitis in 12 patients; and intussusception, intestinal obstruction and ruptured liver abscess in 1 patient each. Ten patients had single perforation while 5 had multiple colonic perforations. All the patients except one had perforations in the right colon. Bowel resection was performed depending upon the site and extent of the colon involved-right hemicolectomy (8), limited ileocolic resection (6) and sigmoidectomy (1). Bowel continuity could be restored only in 2 of the 15 patients and a stoma was constructed in the remaining 13 patients. The overall mortality rate was found to be 40% (6/15). Amoebic colonic perforation is associated with unusually high mortality.

Grain boundary misorientations and percolative current paths in high-{ital J}{sub {ital c}} powder-in-tube (Bi,Pb){sub 2}Sr{sub 3}Ca{sub 3}Cu{sub 3}O{sub {ital x}}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Goyal, A.; Specht, E.D.; Kroeger, D.M.

1995-05-22

Grain orientations and grain boundary misorientations in high-{ital J}{sub {ital c}}, powder-in-tube (PIT) (Bi,Pb){sub 2}Sr{sub 2}Ca{sub 2}Cu{sub 3}O{sub {ital x}} (Bi-2223) were determined using electron backscatter Kikuchi diffraction and x-ray microdiffraction. Data collected from over 113 spatially correlated grains, resulting in 227 grain boundaries, show that over 40% of the boundaries are {Sigma}1 or small angle (less than 15{degree}). In addition, 8% of the boundaries are within the Brandon criterion for CSLs (sigma larger than 1 and less than 50). Grain boundary ``texture maps`` derived from the electron microscope image and orientation data reveal the presence of percolative paths betweenmore » low energy boundaries.« less

Analysis of colonoscopic perforations at a local clinic and a tertiary hospital.

PubMed

Sagawa, Toshihiko; Kakizaki, Satoru; Iizuka, Haruhisa; Onozato, Yasuhiro; Sohara, Naondo; Okamura, Shinichi; Mori, Masatomo

2012-09-21

To define the clinical characteristics, and to assess the management of colonoscopic complications at a local clinic. A retrospective review of the medical records was performed for the patients with iatrogenic colon perforations after endoscopy at a local clinic between April 2006 and December 2010. Data obtained from a tertiary hospital in the same region were also analyzed. The underlying conditions, clinical presentations, perforation locations, treatment types (operative or conservative) and outcome data for patients at the local clinic and the tertiary hospital were compared. A total of 10  826 colonoscopies, and 2625 therapeutic procedures were performed at a local clinic and 32  148 colonoscopies, and 7787 therapeutic procedures were performed at the tertiary hospital. The clinic had no perforations during diagnostic colonoscopy and 8 (0.3%) perforations were determined to be related to therapeutic procedures. The perforation rates in each therapeutic procedure were 0.06% (1/1609) in polypectomy, 0.2% (2/885) in endoscopic mucosal resection (EMR), and 3.8% (5/131) in endoscopic submucosal dissection (ESD). Perforation rates for ESD were significantly higher than those for polypectomy or EMR (P < 0.01). All of these patients were treated conservatively. On the other hand, three (0.01%) perforation cases were observed among the 24  361 diagnostic procedures performed, and these cases were treated with surgery in a tertiary hospital. Six perforations occurred with therapeutic endoscopy (perforation rate, 0.08%; 1 per 1298 procedures). Perforation rates for specific procedure types were 0.02% (1 per 5500) for polypectomy, 0.17% (1 per 561) for EMR, 2.3% (1 per 43) for ESD in the tertiary hospital. There were no differences in the perforation rates for each therapeutic procedure between the clinic and the tertiary hospital. The incidence of iatrogenic perforation requiring surgical treatment was quite low in both the clinic and the tertiary hospital. No procedure-related mortalities occurred. Performing closure with endoscopic clipping reduced the C-reactive protein (CRP) titers. The mean maximum CRP titer was 2.9 ± 1.6 mg/dL with clipping and 9.7 ± 6.2 mg/dL without clipping, respectively (P < 0.05). An operation is indicated in the presence of a large perforation, and in the setting of generalized peritonitis or ongoing sepsis. Although we did not experience such case in the clinic, patients with large perforations should be immediately transferred to a tertiary hospital. Good relationships between local clinics and nearby tertiary hospitals should therefore be maintained. It was therefore found to be possible to perform endoscopic treatment at a local clinic when sufficient back up was available at a nearby tertiary hospital.

Nearly metastable rhombohedral phases of bcc metals

NASA Astrophysics Data System (ADS)

Mehl, Michael J.; Finkenstadt, Daniel

2008-02-01

The energy E(c/a) for a bcc element stretched along its [001] axis (the Bain path) has a minimum at c/a=1 , a maximum at c/a=2 , and an elastically unstable local minimum at c/a>2 . An alternative path connecting the bcc and fcc structures is the rhombohedral lattice. The primitive lattice has R3¯m symmetry, with the angle α changing from 109.4° (bcc), to 90° (simple cubic), to 60 ° (fcc). We study this path for the non-magnetic bcc transition metals (V, Nb, Mo, Ta, and W) using both all-electron linearized augmented plane wave and projector augmented wave VASP codes. Except for Ta, the energy E(α) has a local maximum at α=60° , with local minima near 55° and 70° , the latter having lower energy, suggesting the possibility of a metastable rhombohedral state for these materials. We first examine the elastic stability of the 70° minimum structure, and determine that only W is elastically stable in this structure, with the smallest eigenvalue of the elastic tensor at 4GPa . We then consider the possibility that tungsten is actually metastable in this structure by looking at its vibrational and third-order elastic stability.

Inward current activated by carbachol in rat intestinal smooth muscle cells.

PubMed Central

Ito, S; Ohta, T; Nakazato, Y

1993-01-01

1. Carbachol (0.1 mM or 10 microM)-evoked inward currents were studied with standard and perforated whole-cell patch clamp techniques in smooth muscle cells isolated from rat small intestine. The intracellular free Ca2+ concentration was monitored simultaneously with the fura-2 method. 2. With a K(+)-containing pipette solution, carbachol produced an inward current at -60 mV and a large outward current at -20 mV. 3. When NaCl was substituted for KCl in the external and pipette solutions, carbachol elicited inward currents at holding potentials more inside-negative than 0 mV. The reversal potential of the carbachol-induced current altered when external chloride (-0.9 mV) was replaced by iodide (-21.2 mV), thiocyanate (-27.0 mV) and glutamate (18.2 mV). The carbachol-induced current at -60 mV was slightly decreased by the replacement of external NaCl with Tris-Cl. 4. The carbachol-induced inward current at -60 mV was accompanied by an increase in the intracellular concentration of free Ca2+. Both responses to carbachol were observed 2 min after exposure of the cells to a Ca(2+)-free solution containing 2 mM EGTA. 5. Intracellular application of heparin inhibited the inward current and Ca2+ transient responses to carbachol but not those to caffeine (10 mM). An inward current and Ca2+ transient were elicited after the patch membrane was ruptured at -60 mV, using a patch pipette containing inositol 1,4,5-trisphosphate (InsP3). 6. It is concluded that the carbachol-induced inward current is due to increases in membrane Cl- and Na+ conductances. Ca2+ released from InsP3-sensitive stores may play a role in increasing both conductances. PMID:7508506

[An Analysis of Perforated Gastric Cancer with Acute Peritonitis in Our Hospital].

PubMed

Adachi, Shinichi; Endo, Shunji; Chinen, Yoshinao; Itakura, Hiroaki; Takayama, Hirotoshi; Tsuda, Yujiro; Ueda, Masami; Nakashima, Shinsuke; Ohta, Katsuya; Ikenaga, Masakazu; Yamada, Terumasa

2018-01-01

Perforated gastric cancer is relatively rare and the incidence is reported about 1% of all the cases of gastric cancer. We retrospectively analyzed the clinical data of the consecutive 12 patients with perforated gastric cancer who underwent operation in our hospital between January 2005 and December 2016. There were 5 men and 7 women, with an average age of 65.8 years old(34-87). Perforated gastric cancer occurred in the region U(1 cases), M(6 cases), L(5 cases). There were 11 cases with distant metastasis. We could successfully diagnosed as perforated gastric cancer in 8 cases before emergency operation. Gastrectomy was performed in 5 cases. However, the curative resection was performed only 1 case. Prognosis of perforated gastric cancer is poor. We considered as an appropriate two-step surgical strategy that the first step of surgery is an acute peritonitis treatment followed by radical gastrectomy with lymphadenectomy.

Estradiol-modified prolactin secretion independently of action potentials and Ca2+ and blockade of outward potassium currents in GH3 cells.

PubMed

Sánchez, Manuel; Suárez, Lorena; Cantabrana, Begoña; Bordallo, Javier

2017-01-01

Estrogens facilitate prolactin (PRL) secretion acting on pituitary cells. In GH 3 cells, estradiol induces acute action potentials and oscillations of intracellular Ca 2+ associated with the secretagogue function. Estradiol modulates several ion channels which may affect the action potential rate and the release of PRL in lactotroph cells, which might depend on its concentration. The aims were to characterize the acute effect of supraphysiological concentrations of estradiol on Ca 2+ and noninactivating K + currents and measure the effect on the spontaneous action potentials and PRL release in the somatolactotroph cell line, GH 3 . Electrophysiological studies were carried out by voltage- and current-clamp techniques and ELISA determination of PRL secretion. Pharmacological concentrations of estradiol (above 1 μM), without a latency period, blocked Ca 2+ channels and noninactivating K + currents, including the large-conductance voltage- and Ca 2+ -activated K + channels (BK), studied in whole-cell nystatin perforated and in excided inside-out patches of GH 3 and CHO cells, transiently transfected with the human α-pore forming subunit of BK. The effect on BK was contrary to the agonist effect associated with the regulatory β 1 -subunits of the BK, which GH 3 cells lack, but its transient transfection did not modify the noninactivating current blockade, suggesting a different mechanism of regulation. Estradiol, at the same concentration range, acutely decreased the frequency of action potentials, an expected effect as consequence of the Ca 2+ channel blockade. Despite this, PRL secretion initially increased, followed by a decrease in long-term incubations. This suggests that, in GH 3 cells, supraphysiological concentrations of estradiol modulating PRL secretion are partially independent of extracellular Ca 2+ influx.

Anti-inflammatory and carbonic anhydrase restoring actions of yam powder (Dioscorea spp) contribute to the prevention of cysteamine-induced duodenal ulcer in a rat model.

PubMed

Park, Jong-Min; Kim, Yoon-Jae; Kim, Ju-Seung; Han, Young-Min; Kangwan, Napapan; Hahm, Ki Baik; Kim, Tae-Sok; Kwon, Oran; Kim, Eun-Hee

2013-08-01

Increased acid output, accompanied with a defective defense system, is considered a fundamental pathogenesis of duodenal ulcer (DU). However, relapse of DU occurs despite proton pump inhibitors and H2 receptor antagonists, hence imposing the enforcement of the defense system. Dried powder of the yam tuber (Dioscorea spp) has been used in traditional folk medicine as a nutritional fortification. We hypothesized that dried-yam powder would prevent DU through improvement of anti-inflammatory actions and carbonic anhydrase (CA) activity. Therefore, we investigated the preventive effects of dried-yam powder against the cysteamine-induced DU and elucidated the underlying mechanisms. Duodenal ulcers were induced in Sprague-Dawley rats by intragastric administration of 500 mg/kg cysteamine-HCl. The dried-yam powder was used as a pretreatment before the cysteamine-HCl. The number and size of DU were measured. The expressions of inflammation mediators were checked in duodenal tissues, and the expressions of CAs and malondialdehyde levels were also examined. Cysteamine provoked perforated DU, whereas dried-yam powder significantly prevented DU as much as pantoprazole and significantly reduced the incidence of perforation. The messenger RNA expressions of cyclooxygenase-2 and inducible nitric oxide synthase were remarkably decreased in the yam group compared with the cysteamine group, and the serum levels of proinflammatory cytokines including interleukin-1β, interleukin-6, and tumor necrosis factor were significantly attenuated in the yam group. Cysteamine significantly decreased the expression of CAs, whereas yam treatment significantly preserved the expressions of CA IX, XII, and XIV. In conclusion, dried-yam powder exerts a significant protective effect against cysteamine-induced DU by lowering the activity of inflammatory cytokines and free radicals and restoring the activity of CAs, except in CA IV. Copyright © 2013 Elsevier Inc. All rights reserved.

Incidence of Cardiac Perforation With Conventional and With Leadless Pacemaker Systems: A Systematic Review and Meta-Analysis.

PubMed

Vamos, Mate; Erath, Julia W; Benz, Alexander P; Bari, Zsolt; Duray, Gabor Z; Hohnloser, Stefan H

2017-03-01

Two leadless pacemaker (PM) systems were recently developed to avoid pocket- and lead-related complications. As leadless PMs are implanted with a large delivery catheter, cardiac perforation remains a major safety concern. We aimed to provide a literature review on incidence of cardiac perforation with conventional and with leadless PM systems. A systematic review over the last 25 years for studies reporting data on PM lead perforation was performed. Findings were synthesized descriptively. Where control groups were available, data were meta-analyzed to identify important clinical risk factors. A total of 28 studies comprising 60,744 patients undergoing conventional PM implantation were analyzed. The incidence of lead perforation ranged from 0% to 6.37% (mean 0.82%, weighted mean 0.31%, median of 0.40%). There was no significant difference in perforation risk between atrial and ventricular electrodes (POR 0.72, 95% confidence interval [CI], 0.28-1.87, P = 0.50) and between MRI conditional and conventional leads (POR 5.93, 95% CI, 0.72-48.76, P = 0.10). The use of active fixation leads (POR 4.25, 95% CI, 1.00-17.95, P = 0.05) and utilization of DDD versus VVI PM systems (POR 3.50, 95% CI, 1.48-8.28, P < 0.01) were associated with higher rates of perforation. In the 2 leadless PM studies, the incidence of cardiac perforation was 1.52% for each. PM lead perforation rates vary in individual studies with an overall low incidence. Leadless PMs seem to be associated with a slightly higher perforation risk, most likely reflecting a learning curve effect of this novel technology. © 2016 Wiley Periodicals, Inc.

Cellular mechanisms of desynchronizing effects of hypothermia in an in vitro epilepsy model.

PubMed

Motamedi, Gholam K; Gonzalez-Sulser, Alfredo; Dzakpasu, Rhonda; Vicini, Stefano

2012-01-01

Hypothermia can terminate epileptiform discharges in vitro and in vivo epilepsy models. Hypothermia is becoming a standard treatment for brain injury in infants with perinatal hypoxic ischemic encephalopathy, and it is gaining ground as a potential treatment in patients with drug resistant epilepsy. However, the exact mechanism of action of cooling the brain tissue is unclear. We have studied the 4-aminopyridine model of epilepsy in mice using single- and dual-patch clamp and perforated multi-electrode array recordings from the hippocampus and cortex. Cooling consistently terminated 4-aminopyridine induced epileptiform-like discharges in hippocampal neurons and increased input resistance that was not mimicked by transient receptor potential channel antagonists. Dual-patch clamp recordings showed significant synchrony between distant CA1 and CA3 pyramidal neurons, but less so between the pyramidal neurons and interneurons. In CA1 and CA3 neurons, hypothermia blocked rhythmic action potential discharges and disrupted their synchrony; however, in interneurons, hypothermia blocked rhythmic discharges without abolishing action potentials. In parallel, multi-electrode array recordings showed that synchronized discharges were disrupted by hypothermia, whereas multi-unit activity was unaffected. The differential effect of cooling on transmitting or secreting γ-aminobutyric acid interneurons might disrupt normal network synchrony, aborting the epileptiform discharges. Moreover, the persistence of action potential firing in interneurons would have additional antiepileptic effects through tonic γ-aminobutyric acid release.

The first perforating branch of the deep femoral artery: A reliable recipient vessel for vascularized fibular grafts: An anatomical study.

PubMed

Sur, Yoo Joon; Morsy, Mohamed; Mohan, Anita T; Zhu, Lin; Lachman, Nirusha; Saint-Cyr, Michel

2016-03-01

Although the perforating branches of the deep femoral artery have been introduced as recipient vessels for vascularized fibular grafts in the treatment of osteonecrosis of the femoral head, comprehensive knowledge of the related anatomy is deficient. The aims of this study were to provide detailed anatomical data for the perforating branches of the deep femoral artery and validate their usefulness as recipient vessels for vascularized fibular grafts. Anatomical dissection was performed on 11 fresh human cadaveric lower extremities. The number, locations, and diameters of the perforating branches were documented. The topographic relationships with the vastus ridge and the tendinous insertion of the gluteus maximus were clarified. The diameters of the perforating branches were compared with those of the ascending branch of the lateral circumflex femoral and the peroneal arteries. The mean number of perforating branches was 3.5. The mean distances from the vastus ridge to the first, second, and third perforating branches were 8.1, 13.7, and 20.4 cm, respectively. The first perforating branch was always located medial to the tendinous insertion of the gluteus maximus, whereas the second perforating branch was always located distal to the gluteus maximus. The mean diameters of the first, second, third, and fourth perforating branches were 3.1, 2.3, 1.6, and 1.2 mm, respectively. The mean diameters of the ascending branch of the lateral circumflex femoral and the peroneal arteries were 2.0 and 3.6 mm, respectively. The first perforating branch of the deep femoral artery is an appropriate alternative recipient vessel for vascularized fibular grafts in the treatment of osteonecrosis of the femoral head. It has a very consistent anatomy with a suitable location and diameter for anastomosis of the peroneal artery. Copyright © 2015 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

Comparison of the Multidetector-row Computed Tomographic Angiography Axial and Coronal Planes' Usefulness for Detecting Thoracodorsal Artery Perforators

PubMed Central

Kim, Jong Gyu

2012-01-01

Background During the planning of a thoracodorsal artery perforator (TDAP) free flap, preoperative multidetector-row computed tomographic (MDCT) angiography is valuable for predicting the locations of perforators. However, CT-based perforator mapping of the thoracodorsal artery is not easy because of its small diameter. Thus, we evaluated 1-mm-thick MDCT images in multiple planes to search for reliable perforators accurately. Methods Between July 2010 and October 2011, 19 consecutive patients (13 males, 6 females) who underwent MDCT prior to TDAP free flap operations were enrolled in this study. Patients ranged in age from 10 to 75 years (mean, 39.3 years). MDCT images were acquired at a thickness of 1 mm in the axial, coronal, and sagittal planes. Results The thoracodorsal artery perforators were detected in all 19 cases. The reliable perforators originating from the descending branch were found in 14 cases, of which 6 had transverse branches. The former were well identified in the coronal view, and the latter in the axial view. The location of the most reliable perforators on MDCT images corresponded well with the surgical findings. Conclusions Though MDCT has been widely used in performing the abdominal perforator free flap for detecting reliable perforating vessels, it is not popular in the TDAP free flap. The results of this study suggest that multiple planes of MDCT may increase the probability of detecting the most reliable perforators, along with decreasing the probability of missing available vessels. PMID:22872839

Penetration and perforation of skin by bullets and missiles. A review of the literature.

PubMed

DiMaio, V J

1981-06-01

A review of the literature on perforation of skin by bullets and missiles indicates that there is a range of velocity below which a missile cannot perforate the skin. Velocities of between 38.1 and 61.6 meters/second (125 and 202 ft./second) will produce at least minimal damage to the surface of the skin, though without perforation. In order for a missile to perforate the skin and enter the underlying subcutaneous tissue and muscle, a minimum velocity in the order of 70 meters/second (230 ft./second) is necessary with an energy/area of presentation of approximately 2.1 m-kg/cm2.

Expression and function of K(V)2-containing channels in human urinary bladder smooth muscle.

PubMed

Hristov, Kiril L; Chen, Muyan; Afeli, Serge A Y; Cheng, Qiuping; Rovner, Eric S; Petkov, Georgi V

2012-06-01

The functional role of the voltage-gated K(+) (K(V)) channels in human detrusor smooth muscle (DSM) is largely unexplored. Here, we provide molecular, electrophysiological, and functional evidence for the expression of K(V)2.1, K(V)2.2, and the electrically silent K(V)9.3 subunits in human DSM. Stromatoxin-1 (ScTx1), a selective inhibitor of K(V)2.1, K(V)2.2, and K(V)4.2 homotetrameric channels and of K(V)2.1/9.3 heterotetrameric channels, was used to examine the role of these channels in human DSM function. Human DSM tissues were obtained during open bladder surgeries from patients without a history of overactive bladder. Freshly isolated human DSM cells were studied using RT-PCR, immunocytochemistry, live-cell Ca(2+) imaging, and the perforated whole cell patch-clamp technique. Isometric DSM tension recordings of human DSM isolated strips were conducted using tissue baths. RT-PCR experiments showed mRNA expression of K(V)2.1, K(V)2.2, and K(V)9.3 (but not K(V)4.2) channel subunits in human isolated DSM cells. K(V)2.1 and K(V)2.2 protein expression was confirmed by Western blot analysis and immunocytochemistry. Perforated whole cell patch-clamp experiments revealed that ScTx1 (100 nM) inhibited the amplitude of the voltage step-induced K(V) current in freshly isolated human DSM cells. ScTx1 (100 nM) significantly increased the intracellular Ca(2+) level in DSM cells. In human DSM isolated strips, ScTx1 (100 nM) increased the spontaneous phasic contraction amplitude and muscle force, and enhanced the amplitude of the electrical field stimulation-induced contractions within the range of 3.5-30 Hz stimulation frequencies. These findings reveal that ScTx1-sensitive K(V)2-containing channels are key regulators of human DSM excitability and contractility and may represent new targets for pharmacological or genetic intervention for bladder dysfunction.

Neurodevelopmental Outcomes of Extremely Low Birth Weight Infants with Spontaneous Intestinal Perforation or Surgical Necrotizing Enterocolitis

PubMed Central

Wadhawan, Rajan; Oh, William; Hintz, Susan R; Blakely, Martin L; Das, Abhik; Bell, Edward F.; Saha, Shampa; Laptook, Abbot R.; Shankaran, Seetha; Stoll, Barbara J.; Walsh, Michele C.; Higgins, Rosemary D.

2013-01-01

Objective To determine if extremely low birth weight infants with surgical necrotizing enterocolitis have a higher risk of death or neurodevelopmental impairment and neurodevelopmental impairment among survivors (secondary outcome) at 18–22 months corrected age compared to infants with spontaneous intestinal perforation and infants without necrotizing enterocolitis or spontaneous intestinal perforation. Study Design Retrospective analysis of the Neonatal Research Network very low birth weight registry, evaluating extremely low birth weight infants born between 2000–2005. The study infants were designated into 3 groups: 1) Spontaneous intestinal perforation without necrotizing enterocolitis; 2) Surgical necrotizing enterocolitis (Bell's stage III); and 3) Neither spontaneous intestinal perforation nor necrotizing enterocolitis. Multivariate logistic regression analysis was performed to evaluate the association between the clinical group and death or neurodevelopmental impairment, controlling for multiple confounding factors including center. Results Infants with surgical necrotizing enterocolitis had the highest rate of death prior to hospital discharge (53.5%) and death or neurodevelopmental impairment (82.3%) compared to infants in the spontaneous intestinal perforation group (39.1% and 79.3%) and no necrotizing enterocolitis/no spontaneous intestinal perforation group (22.1% and 53.3%; p<0.001). Similar results were observed for neurodevelopmental impairment among survivors. On logistic regression analysis, both spontaneous intestinal perforation and surgical necrotizing enterocolitis were associated with increased risk of death or neurodevelopmental impairment (adjusted OR 2.21, 95% CI: 1.5, 3.2 and adjusted OR 2.11, 95% CI: 1.5, 2.9 respectively) and neurodevelopmental impairment among survivors (adjusted OR 2.17, 95% CI: 1.4, 3.2 and adjusted OR 1.70, 95% CI: 1.2, 2.4 respectively). Conclusions Spontaneous intestinal perforation and surgical necrotizing enterocolitis are associated with a similar increase in the risk of death or neurodevelopmental impairment and neurodevelopmental impairment among extremely low birth weight survivors at 18–22 months corrected age. PMID:24135709

Glove perforations during open surgery for gynaecological malignancies.

PubMed

Manjunath, A P; Shepherd, J H; Barton, D P J; Bridges, J E; Ind, T E J

2008-07-01

To audit glove perforations at laparotomies for gynaecological cancers. Gynaecological oncology unit, cancer centre, London. Prospective audit. Twenty-nine laparotomies for gynaecological cancers over 3 months. Gloves used during laparotomies for gynaecological cancer were tested for perforations by the air inflation and water immersion technique. Parameters recorded were: type of procedure, localisation of perforation, type of gloves, seniority of surgeon, operation time and awareness of perforations. Glove perforation rate. Perforations were found in gloves from 27/29 (93%) laparotomies. The perforation rate was 61/462 (13%) per glove. The perforation rate was three times higher when the duration of surgery was more than 5 hours. The perforation rate was 63% for primary surgeons, 54.5% for first assistant, 4.7% for second assistant and 40.5% for scrub nurses. Clinical fellows were at highest risk of injury (94%). Two-thirds of perforations were on the index finger or thumb. The glove on the nondominant hand had perforations in 54% of cases. In 50% of cases, the participants were not aware of the perforations. There were less inner glove perforations in double gloves compared with single gloves (5/139 versus 26/154; P = 0.0004, OR = 5.4, 95% CI 1.9-16.7). The indicator glove system failed to identify holes in 44% of cases. Glove perforations were found in most (93%) laparotomies for gynaecological malignancies. They are most common among clinical fellows, are often unnoticed and often not detected by the indicator glove system.

[Iatrogen perforation of the rectum after colon radiography].

PubMed

Eggum, R; Kressner, U; Haffner, J

1998-05-10

Perforation of the rectum following barium enema is relatively rare, occurring in 1 of 3,000 procedures. Colorectal perforation is a serious condition and early diagnosis is of paramount importance in order to avoid any delay in treating the patient. Direct suture of the perforation, lavage, presacral drainage and stomia are the preferred methods of primary surgical treatment.

Intestinal perforation secondary to ingested foreign bodies: a single-center experience with 38 cases.

PubMed

Lin, Xiao-Kun; Wu, Da-Zhou; Lin, Xiao-Fang; Zheng, Na

2017-05-01

The aim of this study is to report our experience with patients with intestinal perforation secondary to ingested foreign bodies (FBs) who were treated surgically at our institution. Between 2001 and 2015, a total of 38 pediatric patients with the diagnosis of intestinal perforation secondary to FBs were retrospectively reviewed. The series comprised 22 males and 16 females. The average age of the patients was 1.9 years. A definitive preoperative history of the ingestion of FBs was obtained for only eight patients. Crying and abdominal pain were the main clinical manifestations. Perforation repair was performed in 29 patients (76.3%), while enterostomy was utilized in five patients (13.2%) and enterectomy in four patients (10.5%). Five perforations occurred in the large intestine, and 33 perforations occurred in the small intestine with the most common site being the distal ileum. Of the 38 FBs recovered, 26 were food objects, while non-food objects were found in 12 patients. All patients recovered well, except one patient with an intestinal obstruction from adhesions that occurred approximately 1 month after discharge. Clinical performance of intestinal perforation secondary to FBs in children is atypical. Most perforations occur in the small intestine. Primary perforation repair is safe and effective, and better outcomes can be achieved.

Spatial variation of vessel grouping in the xylem of Betula platyphylla Roth.

PubMed

Zhao, Xiping

2016-01-01

Vessel grouping in angiosperms may improve hydraulic integration and increase the spread of cavitations through redundancy pathways. Although disputed, it is increasingly attracting research interest as a potentially significant hydraulic trait. However, the variation of vessel grouping in a tree is poorly understood. I measured the number of solitary and grouped vessels in the xylem of Betula platyphylla Roth. from the pith to the bark along the water flow path. The vessel grouping parameters included the mean number of vessels per vessel group (VG), percentage of solitary vessels (SVP), percentage of radial multiple vessels (MVP), and percentage of cluster vessels (CVP). The effects of cambial age (CA) and flow path-length (PL) on the vessel grouping were analyzed using a linear mixed model.VG and CVP increased nonlinearly, SVP decreased nonlinearly with PL. In trunks and branches, VG and CVP decreased nonlinearly, and SVP increased nonlinearly with CA. In roots, the parameters had no change with CA. MVP was almost constant with PL or CA. The results suggest that vessel grouping has a nonrandom variation pattern, which is affected deeply by cambial age and water flow path.

Command Flight Path Display. Phase I and II. Appendix F.

DTIC Science & Technology

1983-09-01

AD -R145 858 COMMAND FLIGHT PATH DISPLAY PHASE I AND 11 APPENDIX F / (U) SYSTEMS ASSOCIATES INC LONG BEACH CA RESOURCE MANAGEMENT SYSTEMS DIY SEP...34- (Appendix F) .ś. SYSTEMS ASSOCIATES INC* of CALIFORNIA t. Resource Management Systems Division DTICL it~~~ll ELECTE 1 o..-- , ~SEP 2 4 1984...Availability Codos Avail and/or Dist Special "i j L i 7 7 .... Contained in this appendix are the various plots generated dur- ing data reduction. Parameters

Computed tomography assessment of lateral pedicle wall perforation by free-hand subaxial cervical pedicle screw placement.

PubMed

Wang, Yingsong; Xie, Jingming; Yang, Zhendong; Zhao, Zhi; Zhang, Ying; Li, Tao; Liu, Luping

2013-07-01

To present the technique of free-hand subaxial cervical pedicle screw (CPS) placement without using intra-operative navigating devices, and to investigate the crucial factors for safe placement and avoidance of lateral pedicle wall perforation, by measuring and classifying perforations with postoperative computed tomography (CT) scan. The placement of CPS has generally been considered as technically demanding and associated with considerable lateral wall perforation rate. For surgeons without access to navigation systems, experience of safe free-hand technique for subaxial CPS placement is especially valuable. A total of 214 consecutive traumatic or degenerative patients with 1,024 CPS placement using the free-hand technique were enrolled. In the operative process, the lateral mass surface was decorticated. Then a small curette was used to identify the pedicle entrance by touching the cortical bone of the medial pedicle wall. It was crucial to keep the transverse angle and make appropriate adjustment with guidance of the resistance of the thick medial cortical bone. The hand drill should be redirected once soft tissue breach was palpated by a slim ball-tip prober. With proper trajectory, tapping, repeated palpation, the 26-30 mm screw could be placed. After the procedure, the transverse angle of CPS trajectory was measured, and perforation of the lateral wall was classified by CT scan: grade 1, perforation of pedicle wall by screw placement, with the external edge of screw deviating out of the lateral pedicle wall equal to or less than 2 mm and grade 2, critical perforation of pedicle wall by screw placement, large than 2 mm. A total of 129 screws (12.64 %) were demonstrated as lateral pedicle wall perforation, of which 101 screws (9.86 %) were classified as grade 1, whereas 28 screws (2.73 %) as grade 2. Among the segments involved, C3 showed an obviously higher perforating rate than other (P < 0.05). The difference between the anatomical pedicle transverse angle and the screw trajectory angle was higher in patients of grade 2 perforation than the others. In the 28 screws of grade 2 perforation verified by axial CT, 26 screws had been palpated as abnormal during operation. However, only 19 out of the 101 screws of grade 1 perforation had shown palpation alarming signs during operation. The average follow-up was 36.8 months (range 5-65 months). There was no symptom and sign of neurovascular injuries. Two screws (0.20 %) were broken, and one screw (0.10 %) loosen. Placement of screw through a correct trajectory may lead to grade 1 perforation, which suggests transversal expansion and breakage of the thinner lateral cortex, probably caused by mismatching of the diameter of 3.5 mm screws and the tiny cancellous bone cavity of pedicle. Grade 1 perforation is deemed as relatively safe to the vertebral artery. Grade 2 perforation means obvious deviation of the trajectory angle of hand drill, which directly penetrates into the transverse foramen, and the risk of vertebral artery injury (VAI) or development of thrombi caused by the irregular blood flow would be much greater compared to grade 1 perforation. Moreover, there are two crucial maneuvers for increasing accuracy of screw placement: identifying the precise entry point using a curette or hand drill to touch the true entrance of the canal after decortication, and guiding CPS trajectory on axial plane by the resistant of thick medial wall.

Lack of utility of measuring serum bilirubin concentration in distinguishing perforation status of pediatric appendicitis.

PubMed

Bonadio, William; Bruno, Santina; Attaway, David; Dharmar, Logesh; Tam, Derek; Homel, Peter

2017-06-01

Pediatric appendicitis is a common, potentially serious condition. Determining perforation status is crucial to planning effective management. Determine the efficacy of serum total bilirubin concentration [STBC] in distinguishing perforation status in children with appendicitis. Retrospective review of 257 cases of appendicitis who received abdominal CT scan and measurement of STBC. There were 109 with perforation vs 148 without perforation. Although elevated STBC was significantly more common in those with [36%] vs without perforation [22%], the mean difference in elevated values between groups [0.1mg/dL] was clinically insignificant. Higher degrees of hyperbilirubinemia [>2mg/dL] were rarely encountered [5%]. Predictive values for elevated STBC in distinguishing perforation outcome were imprecise [sensitivity 38.5%, specificity 78.4%, PPV 56.8%, NPV 63.4%]. ROC curve analysis of multiple clinical and other laboratory factors for predicting perforation status was unenhanced by adding the STBC variable. Specific analysis of those with perforated appendicitis and percutaneously-drained intra-abdominal abscess which was culture-positive for Escherichia coli showed an identical rate of STBC elevation compared to all with perforation. The routine measurement of STBC does not accurately distinguish perforation status in children with appendicitis, nor discern infecting organism in those with perforation and intra-abdominal abscess. Copyright © 2017 Elsevier Inc. All rights reserved.

Ethanol-mediated relaxation of guinea pig urinary bladder smooth muscle: involvement of BK and L-type Ca2+ channels

PubMed Central

Malysz, John; Afeli, Serge A. Y.; Provence, Aaron

2013-01-01

Mechanisms underlying ethanol (EtOH)-induced detrusor smooth muscle (DSM) relaxation and increased urinary bladder capacity remain unknown. We investigated whether the large conductance Ca2+-activated K+ (BK) channels or L-type voltage-dependent Ca2+ channels (VDCCs), major regulators of DSM excitability and contractility, are targets for EtOH by patch-clamp electrophysiology (conventional and perforated whole cell and excised patch single channel) and isometric tension recordings using guinea pig DSM cells and isolated tissue strips, respectively. EtOH at 0.3% vol/vol (∼50 mM) enhanced whole cell BK currents at +30 mV and above, determined by the selective BK channel blocker paxilline. In excised patches recorded at +40 mV and ∼300 nM intracellular Ca2+ concentration ([Ca2+]), EtOH (0.1–0.3%) affected single BK channels (mean conductance ∼210 pS and blocked by paxilline) by increasing the open channel probability, number of open channel events, and open dwell-time constants. The amplitude of single BK channel currents and unitary conductance were not altered by EtOH. Conversely, at ∼10 μM but not ∼2 μM intracellular [Ca2+], EtOH (0.3%) decreased the single BK channel activity. EtOH (0.3%) affected transient BK currents (TBKCs) by either increasing frequency or decreasing amplitude, depending on the basal level of TBKC frequency. In isolated DSM strips, EtOH (0.1–1%) reduced the amplitude and muscle force of spontaneous phasic contractions. The EtOH-induced DSM relaxation, except at 1%, was attenuated by paxilline. EtOH (1%) inhibited L-type VDCC currents in DSM cells. In summary, we reveal the involvement of BK channels and L-type VDCCs in mediating EtOH-induced urinary bladder relaxation accommodating alcohol-induced diuresis. PMID:24153429

Profound blockage of CXCR4 signaling at multiple points using the synergy between plerixafor, mirtazapine, and clotrimazole as a new glioblastoma treatment adjunct.

PubMed

Kast, Richard E

2010-10-01

CXCL12 signaling at CXCR4 is important in glioblastoma growth promotion as a migration-directing chemokine and as a mitosis-stimulating cytokine system. Recent developments in other areas of medicine may have made it now possible to comprehensively block glioblastoma's use of CXCL12 signaling. CXCL12 signaling at CXCR4 requires an active intermediate conductance Ca2+-activated K+ channel to function. Plerixafor (AMD3100) is a new small molecular weight inhibitor of CXCR4, FDA approved to aid in stem cell mobilization. Inhibition of CXCR4 by plerixafor is expected to inhibit particularly the glioblastoma stem cell population by inhibiting that sub-population's homing to the protective hypoxic niche. Histamine signals through the H1 receptor in glioblastoma cells to activate the intermediate conductance Ca2+-activated K+ channel also, thereby forming a potential bypass for inhibition of CXCR4-initiated signaling. The antidepressant mirtazapine is perhaps the most potent H1 antagonist in common clinical use. By inhibiting H1 stimulation of intermediate conductance Ca2+-activated K+ channels, it could prevent circumvention of CXCR4 inhibition by that path. The anti-fungal clotrimazole directly inhibits the intermediate conductance Ca2+- activated K+ channel at clinically achievable and well-tolerated doses. These three drugs used simultaneously are potential low morbidity paths to deeply inhibit CXCR4/CXCL12 signaling during cytotoxic glioblastoma treatment.

Electrogenic Na+/Ca2+ Exchange

PubMed Central

Danaceau, Jonathan P.; Lucero, Mary T.

2000-01-01

Olfactory receptor neurons (ORNs) from the squid, Lolliguncula brevis, respond to the odors l-glutamate or dopamine with increases in internal Ca2+ concentrations ([Ca2+]i). To directly asses the effects of increasing [Ca2+]i in perforated-patched squid ORNs, we applied 10 mM caffeine to release Ca2+ from internal stores. We observed an inward current response to caffeine. Monovalent cation replacement of Na+ from the external bath solution completely and selectively inhibited the caffeine-induced response, and ruled out the possibility of a Ca2+-dependent nonselective cation current. The strict dependence on internal Ca2+ and external Na+ indicated that the inward current was due to an electrogenic Na+/Ca2+ exchanger. Block of the caffeine-induced current by an inhibitor of Na+/Ca2+ exchange (50–100 μM 2′,4′-dichlorobenzamil) and reversibility of the exchanger current, further confirmed its presence. We tested whether Na+/Ca2+ exchange contributed to odor responses by applying the aquatic odor l-glutamate in the presence and absence of 2′,4′-dichlorobenzamil. We found that electrogenic Na+/Ca2+ exchange was responsible for ∼26% of the total current associated with glutamate-induced odor responses. Although Na+/Ca2+ exchangers are known to be present in ORNs from numerous species, this is the first work to demonstrate amplifying contributions of the exchanger current to odor transduction. PMID:10828249

A novel lateral IGBT with a controlled anode for on-off-state loss trade-off improvement

NASA Astrophysics Data System (ADS)

Wensuo, Chen; Bo, Zhang; Jian, Fang; Zhaoji, Li

2011-07-01

A new lateral insulated-gate bipolar transistor with a controlled anode (CA-LIGBT) on silicon-on-insulator (SOI) substrate is reported. Benefiting from both the enhanced conductivity modulation effect and the high resistance controlled electron extracting path, CA-LIGBT has a faster turn-off speed and lower forward drop, and the trade-off between off-state and on-state losses is better than that of state-of-the-art 3-D NCA-LIGBT, which we presented earlier. As the simulation results show, the ratios of figure of merit (FOM) for CA-LIGBT compared to that of 3-D NCA-LIGBT and conventional LIGBT are 1.45: 1 and 59.53: 1, respectively. And, the new devices can be created by using additional silicon direct bonding (SDB). So, from the power efficiency point of view, the proposed CA-LIGBT is a promising device for use in power ICs.

Type-3 ryanodine receptors mediate hypoxia-, but not neurotransmitter-induced calcium release and contraction in pulmonary artery smooth muscle cells.

PubMed

Zheng, Yun-Min; Wang, Qing-Song; Rathore, Rakesh; Zhang, Wan-Hui; Mazurkiewicz, Joseph E; Sorrentino, Vincenzo; Singer, Harold A; Kotlikoff, Michael I; Wang, Yong-Xiao

2005-04-01

In this study we examined the expression of RyR subtypes and the role of RyRs in neurotransmitter- and hypoxia-induced Ca2+ release and contraction in pulmonary artery smooth muscle cells (PASMCs). Under perforated patch clamp conditions, maximal activation of RyRs with caffeine or inositol triphosphate receptors (IP3Rs) with noradrenaline induced equivalent increases in [Ca2+]i and Ca2+-activated Cl- currents in freshly isolated rat PASMCs. Following maximal IP3-induced Ca2+ release, neither caffeine nor chloro-m-cresol induced a response, whereas prior application of caffeine or chloro-m-cresol blocked IP3-induced Ca2+ release. In cultured human PASMCs, which lack functional expression of RyRs, caffeine failed to affect ATP-induced increases in [Ca2+]i in the presence and absence of extracellular Ca2+. The RyR antagonists ruthenium red, ryanodine, tetracaine, and dantrolene greatly inhibited submaximal noradrenaline- and hypoxia-induced Ca2+ release and contraction in freshly isolated rat PASMCs, but did not affect ATP-induced Ca2+ release in cultured human PASMCs. Real-time quantitative RT-PCR and immunofluorescence staining indicated similar expression of all three RyR subtypes (RyR1, RyR2, and RyR3) in freshly isolated rat PASMCs. In freshly isolated PASMCs from RyR3 knockout (RyR3-/-) mice, hypoxia-induced, but not submaximal noradrenaline-induced, Ca2+ release and contraction were significantly reduced. Ruthenium red and tetracaine can further inhibit hypoxic increase in [Ca2+]i in RyR3-/- mouse PASMCs. Collectively, our data suggest that (a) RyRs play an important role in submaximal noradrenaline- and hypoxia-induced Ca2+ release and contraction; (b) all three subtype RyRs are expressed; and (c) RyR3 gene knockout significantly inhibits hypoxia-, but not submaximal noradrenaline-induced Ca2+ and contractile responses in PASMCs.

Predictors of appendiceal perforation in an equal access system.

PubMed

Walker, Avery; Hatch, Quinton; Drake, Thurston; Nelson, Daniel W; Fitzpatrick, Emilie; Bingham, Jason; Black, George; Maykel, Justin A; Steele, Scott R

2014-07-01

Discrepancies in socioeconomic factors have been associated with higher rates of perforated appendicitis. As an equal-access health care system theoretically removes these barriers, we aimed to determine if remaining differences in demographics, education, and pay result in disparate outcomes in the rate of perforated appendicitis. All patients undergoing appendectomy for acute appendicitis (November 2004-October 2009) at a tertiary care equal access institution were categorized by demographics and perioperative data. Rank of the sponsor was used as a surrogate for economic status. A multivariate logistic regression model was performed to determine patient and clinical characteristics associated with perforated appendicitis. A total of 680 patients (mean age 30±16 y; 37% female) were included. The majority were Caucasian (56.4% [n=384]; African Americans 5.6% [n=38]; Asians 1.9% [n=13]; and other 48.9% [n=245]) and enlisted (87.2%). Overall, 6.4% presented with perforation, with rates of 6.6%, 5.8%, and 6.7% (P=0.96) for officers, enlisted soldiers, and contractors, respectively. There was no difference in perforation when stratified by junior or senior status for either officers or enlisted (9.3% junior versus 4.40% senior officers, P=0.273; 6.60% junior versus 5.50% senior enlisted, P=0.369). On multivariate analysis, parameters such as leukocytosis and temperature, as well as race and rank were not associated with perforation (P=0.7). Only age had a correlation, with individuals aged 66-75 y having higher perforation rates (odds ratio, 1.04; 95% confidence interval, 1.02-1.05; P<0.001). In an equal-access health care system, older age, not socioeconomic factors, correlated with increased appendiceal perforation rates. Published by Elsevier Inc.

Fouling resilient perforated feed spacers for membrane filtration.

PubMed

Kerdi, Sarah; Qamar, Adnan; Vrouwenvelder, Johannes S; Ghaffour, Noreddine

2018-04-24

The improvement of feed spacers with optimal geometry remains a key challenge for spiral-wound membrane systems in water treatment due to their impact on the hydrodynamic performance and fouling development. In this work, novel spacer designs are proposed by intrinsically modifying cylindrical filaments through perforations. Three symmetric perforated spacers (1-Hole, 2-Hole, and 3-Hole) were in-house 3D-printed and experimentally evaluated in terms of permeate flux, feed channel pressure drop and membrane fouling. Spacer performance is characterized and compared with standard no perforated (0-Hole) design under constant feed pressure and constant feed flow rate. Perforations in the spacer filaments resulted in significantly lowering the net pressure drop across the spacer filled channel. The 3-Hole spacer was found to have the lowest pressure drop (50%-61%) compared to 0-Hole spacer for various average flow velocities. Regarding permeate flux production, the 0-Hole spacer produced 5.7 L m -2 .h -1 and 6.6 L m -2 .h -1 steady state flux for constant pressure and constant feed flow rate, respectively. The 1-Hole spacer was found to be the most efficient among the perforated spacers with 75% and 23% increase in permeate production at constant pressure and constant feed flow, respectively. Furthermore, membrane surface of 1-Hole spacer was found to be cleanest in terms of fouling, contributing to maintain higher permeate flux production. Hydrodynamic understanding of these perforated spacers is also quantified by performing Direct Numerical Simulation (DNS). The performance enhancement of these perforated spacers is attributed to the formation of micro-jets in the spacer cell that aided in producing enough unsteadiness/turbulence to clean the membrane surface and mitigate fouling phenomena. In the case of 1-Hole spacer, the unsteadiness intensity at the outlet of micro-jets and the shear stress fluctuations created inside the cells are higher than those observed with other perforated spacers, resulting in the cleanest membrane surface. Copyright © 2018 Elsevier Ltd. All rights reserved.

Risk of surgical glove perforation in oral and maxillofacial surgery.

PubMed

Kuroyanagi, N; Nagao, T; Sakuma, H; Miyachi, H; Ochiai, S; Kimura, Y; Fukano, H; Shimozato, K

2012-08-01

Oral and maxillofacial surgery, which involves several sharp instruments and fixation materials, is consistently at a high risk for cross-contamination due to perforated gloves, but it is unclear how often such perforations occur. This study aimed to address this issue. The frequency of the perforation of surgical gloves (n=1436) in 150 oral and maxillofacial surgeries including orthognathic surgery (n=45) was assessed by the hydroinsufflation technique. Orthognathic surgery had the highest perforation rate in at least 1 glove in 1 operation (91.1%), followed by cleft lip and palate surgery (55.0%), excision of oral soft tumour (54.5%) and dental implantation (50.0%). The perforation rate in scrub nurses was 63.4%, followed by 44.4% in surgeons and first assistants, and 16.3% in second assistants. The odds ratio for the perforation rate in orthognathic surgery versus other surgeries was 16.0 (95% confidence interval: 5.3-48.0). The protection rate offered by double gloving in orthognathic surgery was 95.2%. These results suggest that, regardless of the surgical duration and blood loss in all fields of surgery, orthognathic surgery must be categorized in the highest risk group for glove perforation, following gynaecological and open lung surgery, due to the involvement of sharp objects. Copyright © 2012 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

Gallbladder perforation: case series and systematic review.

PubMed

Date, Ravindra S; Thrumurthy, Sri G; Whiteside, Sigrid; Umer, Mohammed A; Pursnani, Kishore G; Ward, Jeremy B; Mughal, M Muntzer

2012-01-01

Gallbladder perforation is a serious complication of acute cholecystitis. Its management has evolved considerably since its classification by Niemeier in 1934. This review summarises the evidence surrounding the natural progression of this condition and potential problems with Niemeier's classification, and proposes a management algorithm for the more complex type II perforation. Data from a retrospective case series and a systematic review were combined. The case series included all patients with gallbladder perforations from 2004 to 2008 at a British teaching hospital. The systematic review searched for gallbladder perforation using the MEDLINE, Embase, Web of Science and Cochrane Library (2011 Issue 4) databases, as well as recent conference abstracts. The outcome data were analysed using SPSS version 15. No adjustments were made for multiple testing. 198 patients (including 19 patients from the present series) with a mean age of 62.1+/-9.7 years and male gender proportion of 55.4% (range 33.3-76.7%) were included. The most common gallbladder perforations were type II (median 46.2%, range 7.4-83.3%), followed by type I (median 40.6%, range 16.7-70.0%) and type III (median 10.1%, range 0-48.1%). Perforation was associated with cholelithiasis in 86.6% (range 78.9-90.6%) of patients, and the overall median mortality rate was 10.8% (range 0-12.5%). Male gender was weakly associated with mortality (p = 0.089) but age (p = 0.877) and cholelithiasis (p = 0.425) were not. Mortality did not vary significantly with perforation type. Gallbladder perforation should be reported according to the original Neimeier's classification to avoid heterogeneity in data (e.g. varying rates of perforation types). The algorithm proposed in this study aims to guide the management of complex type II gallbladder perforations to minimise subsequent morbidity and mortality. Copyright © 2012 Surgical Associates Ltd. Published by Elsevier Ltd. All rights reserved.

Pedicle Perforation While Inserting Screws Using O-Arm Navigation During Surgery for Adolescent Idiopathic Scoliosis: Risk Factors and Effect of Insertion Order.

PubMed

Oba, Hiroki; Ebata, Shigeto; Takahashi, Jun; Koyama, Kensuke; Uehara, Masashi; Kato, Hiroyuki; Haro, Hirotaka; Ohba, Tetsuro

2018-06-11

Observational cohort study. To compare the rate of pedicle perforation while inserting screws (PS) using O-arm navigation during surgery for scoliosis with that reported previously, and to determine risk factors specific to O-arm navigation. O-arm navigation provides intraoperative three-dimensional fluoroscopic imaging with an image quality similar to that of computed tomography. Surgeons have started using O-arm navigation in treatment of adolescent idiopathic sclerosis (AIS). However, there are few reports of the perforation rate when using O-arm navigation to insert pedicle screws for AIS. To our knowledge, no information has been published regarding risk factors for pedicle perforation by PS when using O-arm navigation during surgery for AIS. We retrospectively reviewed the cases of 23 consecutive patients with AIS (all female; mean age 15.4 years, range 12-19 years) who had all undergone PS fixation under O-arm navigation. There were 11 major pedicle perforations (Grade 2 or 3) by the 404 screws (2.7%). For both Grade 1-3 and Grade 2 or 3 perforations, the pedicle perforation rate by the ninth or subsequent screws was significantly higher than that for the other two groups (screws 1-4, 5-8) (P < 0.01). Grade 1-3, Grades 2 or 3, and Grade 3 perforation rates after a previous perforation were significantly higher than those in patients without a previous perforation (P < 0.01). The rate of screw deviation can increase significantly to 12.2% after insertion of 8. The rate of major perforation of pedicles after inserting PS using O-arm navigation during surgery for AIS is relatively low. However, we recommend caution using intraoperative navigation after inserting 8 pedicle screws because after this, the trajectory deviation rate can increase significantly. 3.

Perforated peptic ulcer (PPU) in pregnancy during Ramadan fasting.

PubMed

Gali, B M; Ibrahim, A G; Chama, C M; Mshelia, H B; Abubakar, A; Takai, I U; Takie, U; Bwala, S

2011-01-01

Perforated Peptic Ulcer (PPU) is extremely rare in pregnancy. We report a case of perforated peptic ulcer in pregnancy during Ramadan fasting. The patient is a 16 years old primigravida who presented with features of peritonitis at 28weeks of gestation while fasting during Ramadan. Ultrasound scan reported a singleton live fetus at 28 weeks gestation. At laparotomy via upper midline incision; a 1 cm roundish perforation located on the duodenum anteriorly was found with about a litre of gastric juice mixed with blood and food particles in the peritoneal cavity. The perforation was close transversely with omental patch (Modified Graham's patch) and peritoneal lavage done with warm saline. She had a preterm delivery of a 1 kg baby 3 days post-operatively by a spontaneous vaginal delivery, but the baby died 3 days later. Perforated Peptic Ulcer(PPU) though rare in pregnancy can occur and fasting can be a risk factor.

Activation of muscarinic M3 receptors inhibits large-conductance voltage- and Ca2+-activated K+ channels in rat urinary bladder smooth muscle cells

PubMed Central

Parajuli, Shankar P.

2013-01-01

Large conductance voltage- and Ca2+-activated K+ (BK) channels are key regulators of detrusor smooth muscle (DSM) contraction and relaxation during urine voiding and storage. Here, we explored whether BK channels are regulated by muscarinic receptors (M-Rs) in native freshly isolated rat DSM cells under physiological conditions using the perforated whole cell patch-clamp technique and pharmacological inhibitors. M-R activation with carbachol (1 μM) initially evoked large transient outward BK currents, followed by inhibition of the spontaneous transient outward BK currents (STBKCs) in DSM cells. Carbachol (1 μM) also inhibited the amplitude and frequency of spontaneous transient hyperpolarizations (STHs) and depolarized the DSM cell membrane potential. Selective inhibition of the muscarinic M3 receptors (M3-Rs) with 4-diphenylacetoxy-N-methylpiperidine (4-DAMP; 0.1 μM), but not muscarinic M2 receptors with methoctramine (1 μM), blocked the carbachol inhibitory effects on STBKCs. Furthermore, blocking the inositol 1,4,5-triphosphate (IP3) receptors with xestospongin-C (1 μM) inhibited the carbachol-induced large transient outward BK currents without affecting carbachol inhibitory effects on STBKCs. Upon pharmacological inhibition of all known cellular sources of Ca2+ for BK channel activation, carbachol (1 μM) did not affect the voltage-step-induced steady-state BK currents, suggesting that the muscarinic effects in DSM cells are mediated by mobilization of intracellular Ca2+. In conclusion, our findings provide strong evidence that activation of M3-Rs leads to inhibition of the STBKCs, STHs, and depolarization of DSM cells. Collectively, the data suggest the existence of functional interactions between BK channels and M3-Rs at a cellular level in DSM. PMID:23703523

On the role of endogenous G-protein βγ subunits in N-type Ca2+ current inhibition by neurotransmitters in rat sympathetic neurones

PubMed Central

Delmas, Patrick; Brown, David A; Dayrell, Mariza; Abogadie, Fe C; Caulfield, Malcolm P; Buckley, Noel J

1998-01-01

Using whole-cell and perforated-patch recordings, we have examined the part played by endogenous G-protein βγ subunits in neurotransmitter-mediated inhibition of N-type Ca2+ channel current ICa) in dissociated rat superior cervical sympathetic neurones. Expression of the C-terminus domain of β-adrenergic receptor kinase 1 (βARK1), which contains the consensus motif (QXXER) for binding Gβγ, reduced the fast (pertussis toxin (PTX)-sensitive) and voltage-dependent inhibition of ICa by noradrenaline and somatostatin, but not the slow (PTX-insensitive) and voltage-independent inhibition induced by angiotensin II. βARK1 peptide reduced GTP-γ-S-induced voltage-dependent and PTX-sensitive inhibition of ICa but not GTP-γ-S-mediated voltage-independent inhibition. Overexpression of Gβ1γ2, which mimicked the voltage-dependent inhibition by reducing ICa density and enhancing basal facilitation, occluded the voltage-dependent noradrenaline- and somatostatin-mediated inhibitions but not the inhibition mediated by angiotensin II. Co-expression of the C-terminus of βARK1 with β1 and γ2 subunits prevented the effects of Gβγ dimers on basal Ca2+ channel behaviour in a manner consistent with the sequestering of Gβγ. The expression of the C-terminus of βARK1 slowed down reinhibition kinetics of ICa following conditioning depolarizations and induced long-lasting facilitation by cumulatively sequestering βγ subunits. Our findings identify endogenous Gβγ as the mediator of the voltage-dependent, PTX-sensitive inhibition of ICa induced by both noradrenaline and somatostatin but not the voltage-independent, PTX-insensitive inhibition by angiotensin II. They also support the view that voltage-dependent inhibition results from a direct Gβγ-Ca2+ channel interaction. PMID:9490860

From childhood adversity to problem behaviors: Role of psychological and structural social integration.

PubMed

Chao, Lo-Hsin; Tsai, Meng-Che; Liang, Ya-Lun; Strong, Carol; Lin, Chung-Ying

2018-01-01

Childhood adversity (CA) is associated with problem behaviors in adolescence, but the mediators, that is, those factors that help build resilience and prevent some children who experience CA from engaging in problem behaviors, await more exploration, including social integration. The aim of this study was to identify the association between CA and adolescent problem behaviors, and to further examine the mediating role of social integration distinctly as psychological and structural integration. Data used were from the Taiwan Education Panel Survey, a core panel of 4,261 students (age 13) surveyed in 2001 and followed for three more waves until age 18. For psychological integration, an average score was calculated to represent adolescents' feelings about their school. Structural integration was constructed using several items about adolescents' school and extracurricular activities. We used structural equation modeling with the diagonally weighted least squares method to examine the effect of CA on the primary outcome: adolescent problem behaviors via social integration. The hypothesized structural equation model specifying the path from CA to adolescent problem behavior had good fit. Respondents with one CA were indirectly linked to problem behaviors via psychological but not structural integration (e.g. the level of participation in school and non-school activities). On mediation analysis, psychological integration significantly mediated the paths from one CA to all six problem behaviors (all P < 0.05). The presence of only one CA was indirectly associated with problem behavior via psychological integration; two or more CA were not associated with significant paths to problem behaviors. The contribution of social integration is crucial to an adolescent's development from CA to problem behaviors. To form supportive social relationships to achieve better health, we suggest that those adolescents who have been exposed to CA should be helped to join more teams and take part in more activities, thereby increasing their opportunities for social interaction, and improving their communication skills. © 2017 Japan Pediatric Society.

Malignant gastric lymphoma with spontaneous perforation.

PubMed

Shimada, Satoko; Gen, Tokichi; Okamoto, Hiroyuki

2013-01-17

Malignant gastric lymphoma, accounting only for 1% of primary gastric carcinoma, is usually a diffuse large B-cell lymphoma. Toyota et al reported that 37% of gastric perforations involved malignancy, generally gastric carcinoma. Fukuda et al found that less than 5% of malignant gastric lymphomas perforate. While it is relatively well known that perforations often take place during chemotherapy, they are rare in patients not receiving chemotherapy. To our knowledge, spontaneous perforation is rare in gastric malignant lymphoma, having been reported in the Japanese literature only 26 times, including this case, in the last 25 years.

[Reconstruction of ankle and foot with combination of free perforator flaps and skin graft].

PubMed

Yin, Lu; Gong, Ketong; Yin, Zhonggang; Zhang, Bo; Xu, Jianhua

2017-03-01

To evaluate the clinical outcomes of free perforator flaps combined with skin graft for reconstruction of ankle and foot soft tissue defects. Between June 2014 and October 2015, 20 cases of ankle and foot soft tissue defects were treated. There were 16 males and 4 females, aged from 19 to 61 years (mean, 43.3 years). Injury was caused by traffic accident in 7 cases, by crashing in 9 cases, and machine twist in 4 cases. The locations were the ankle in 6 cases, the heel in 3 cases, the dorsum pedis in 4 cases, and the plantar forefoot in 7 cases of avulsion injury after toes amputation. The size of wound ranged from 15 cm×10 cm to 27 cm×18 cm. The time from injury to treatment was from 11 to 52 days (mean, 27 days). The anterolateral thigh perforator flap was used in 11 cases, thoracodorsal antery perforator flap in 3 cases, medial sural artery perforator flap in 4 cases, deep inferior epigastric perforator flap in 1 case, and anteromedial thigh perforator flap in 1 case, including 5 chimeric perforator flaps, 5 polyfoliate perforator flaps, 3 flow-through perforator flaps, and 3 conjoined perforator flaps. The size of the perforator flap ranged from 10.0 cm×6.5 cm to 36.0 cm×8.0 cm, the size of skin graft from 5 cm×3 cm to 18 cm×12 cm. Venous crisis occurred in 2 flaps which survived after symptomatic treatment; 18 flaps survived successfully and skin grafting healed well. The follow-up time ranged 4-18 months (mean, 8.3 months). The flaps had good appearance, texture and color, without infection. The patients could walk normally and do daily activities. Only linear scars were observed at the donor sites. Free perforator flap can be used to reconstruct defects in the ankle and foot, especially in the weight-bearing area of the plantar forefoot. A combination of free perforator flap and skin graft is ideal in reconstruction of great soft tissue defects in the ankle and foot.

Paramuscular perforators in DIEAP flap for breast reconstruction.

PubMed

Pons, Gemma; Masia, Jaume; Sanchez-Porro, Lídia; Larrañaga, Jose; Clavero, Juan Angel

2014-12-01

One of the main steps in perforator flap surgery is to identify the dominant perforator. Using multidetector row computed tomography (MDCT) for the preoperative planning of deep inferior epigastric artery perforator (DIEAP) flap surgery, we identified a perforator with a large caliber, an excellent location in the middle abdominal region, and a totally extramuscular trajectory in a significant number of patients. We describe the frequency of this perforator and determine its characteristics. We conducted a retrospective study of 482 patients who underwent 526 DIEAP flaps for breast reconstruction from October 2003 to October 2011. Mean age at surgery was 51.3 years old. A preoperative MDCT of abdominal vascularization was performed in all patients. MDCT identified a dominant perforator with a paramuscular course in 12.4% of abdominal walls. In all cases, it was located in the midline and emerged directly from the deep inferior epigastric system. Its mean caliber was 1.9 mm. The flap was harvested based on this perforator in all these patients, and mean harvest time was 51 minutes. The characteristics of this perforator made dissection easier and reduced morbidity at the donor site. There were no flap losses and the only complications were minor. We located a paramuscular perforator in 12.4% of patients undergoing breast reconstruction with abdominal perforator flaps. Its morphological features and extramuscular course make it the perforator of choice in DIEAP flap surgery.

Dependence of electrical transport properties of CaO(CaMnO3)m (m = 1, 2, 3, ∞) thermoelectric oxides on lattice periodicity

NASA Astrophysics Data System (ADS)

Baranovskiy, Andrei; Amouyal, Yaron

2017-02-01

The electrical transport properties of CaO(CaMnO3)m (m = 1, 2, 3, ∞) compounds are studied applying the density functional theory (DFT) in terms of band structure at the vicinity of the Fermi level (EF). It is shown that the total density of states (DOS) values at EF increase with increase in the m-values, which implies an increase in the electrical conductivity, σ, with increasing m-values, in full accordance with experimental results. Additionally, the calculated values of the relative slopes of the DOS at EF correlate with the experimentally measured Seebeck coefficients. The electrical conductivity and Seebeck coefficients were calculated in the framework of the Boltzmann transport theory applying the constant relaxation time approximation. By the analysis of experimental and calculated σ(Τ) dependences, the electronic relaxation time and mean free path values were estimated. It is shown that the electrical transport is dominated by electron scattering on the boundaries between perovskite (CaMnO3) and Ca oxide (CaO) layers inside the crystal lattice.

Overview in two parts: Right view showing orchard path on ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Overview in two parts: Right view showing orchard path on left eucalyptus windbreak bordering knoll on right. Camera facing 278" west. - Goerlitz House, 9893 Highland Avenue, Rancho Cucamonga, San Bernardino County, CA

7. ORIGINAL SOUTH SIDE, EAST PART, ALSO SHOWING PATH FROM ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

7. ORIGINAL SOUTH SIDE, EAST PART, ALSO SHOWING PATH FROM EAST FRONT LEADING TO CENTRAL CAMPUS. - U.S. Geological Survey, Rock Magnetics Laboratory, 345 Middlefield Road, Menlo Park, San Mateo County, CA

Surgical therapies for corneal perforations: 10 years of cases in a tertiary referral hospital

PubMed Central

Yokogawa, Hideaki; Kobayashi, Akira; Yamazaki, Natsuko; Masaki, Toshinori; Sugiyama, Kazuhisa

2014-01-01

Purpose To report surgical therapies for corneal perforations in a tertiary referral hospital. Methods Thirty-one eyes of 31 patients (aged 62.4±18.3 years) with surgically treated corneal perforations from January 2002 to July 2013 were included in this study. Demographic data such as cause of corneal perforation, surgical procedures, and visual outcomes were retrospectively analyzed. Results The causes of corneal perforation (n=31) were divided into infectious (n=8, 26%) and noninfectious (n=23, 74%) categories. Infectious causes included fungal ulcer, herpetic stromal necrotizing keratitis, and bacterial ulcer. The causes of noninfectious keratopathy included corneal melting after removal of a metal foreign body, severe dry eye, lagophthalmos, canaliculitis, the oral anticancer drug S-1, keratoconus, rheumatoid arthritis, neurotrophic ulcer, atopic keratoconjunctivitis, and unknown causes. Initial surgical procedures included central large corneal graft (n=17), small corneal graft (n=7), and amniotic membrane transplantation (n=7). In two cases the perforation could not be sealed during the first surgical treatment and required subsequent procedures. All infectious keratitis required central large penetrating keratoplasty to obtain anatomical cure. In contrast, several surgical options were used for the treatment of noninfectious keratitis. After surgical treatment, anatomical cure was obtained in all cases. Mean postoperative best corrected visual acuity was better at 6 months (logMAR 1.3) than preoperatively (logMAR 1.8). Conclusion Surgical therapies for corneal perforations in our hospital included central large lamellar/penetrating keratoplasty, small peripheral patch graft, and amniotic membrane transplantation. All treatments were effective. Corneal perforation due to the oral anticancer drug S-1 is newly reported. PMID:25378903

[The sural medial perforator flap: Anatomical bases, surgical technique and indications in head and neck reconstruction].

PubMed

Struk, S; Schaff, J-B; Qassemyar, Q

2018-04-01

The medial sural artery perforator (MSAP) flap is defined as a thin cutaneo-adipose perforator flap harvested on the medial aspect of the leg. The aims of this study were to describe the anatomical basis as well as the surgical technique and discuss the indications in head and neck reconstructive surgery. We harvested 10 MSAP flap on 5 fresh cadavers. For each case, the number and the location of the perforators were recorded. For each flap, the length of pedicle, the diameter of source vessels and the thickness of the flap were studied. Finally, we performed a clinical application of a MSAP flap. A total of 23 perforators with a diameter superior than 1mm were dissected on 10 legs. The medial sural artery provided between 1 and 4 musculocutaneous perforators. Perforators were located in average at 10.3cm±2cm from the popliteal fossa and at 3.6cm±1cm from the median line of the calf. The mean pedicle length was 12.1cm±2.5cm. At its origin, the source artery diameter was 1.8mm±0.25mm and source veins diameters were 2.45mm±0.9mm in average. There was no complication in our clinical application. This study confirms the reliability of previous anatomical descriptions of the medial sural artery perforator flap. This flap was reported as thin and particularly adapted for oral cavity reconstruction and for facial or limb resurfacing. Sequelae might be reduced as compared to those of the radial forearm flap with comparable results. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Validation of Boey's score in predicting morbidity and mortality in peptic perforation peritonitis in Northwestern India.

PubMed

Agarwal, Abhishek; Jain, Sanchit; Meena, L N; Jain, Sumita A; Agarwal, Lakshman

2015-01-01

The major complications of peptic ulcer are hemorrhage, perforation and gastric outlet obstruction with perforation occurring in about 2-10% of patients. Patients with perforated peptic ulcer still have a high rate of morbidity and mortality and to improve the outcomes it is important to stratify the patients into different categories. To evaluate the accuracy of Boey scoring system in predicting postoperative morbidity and mortality in patients operated for peptic perforation. It was a prospective observational single centre study conducted at SMS Medical College and Hospital, Jaipur, from October 2011 to October 2012 on 180 patients undergoing open surgery for peptic ulcer perforation. Postoperative outcomes in terms of recovery and complications were studied. For prediction of morbidity and mortality by Boey risk stratification, the odds ratio (OR) and 95% confidence interval (95% CI) of each risk score were compared with the outcomes of "0" risk score. The mortality rate increased progressively with increasing numbers of the Boey score: 1.9%, 7.1%, 31.7% and 40% for 0, 1, 2, and 3 scores, respectively (p < 0.001). The morbidity rates for 0, 1, 2, and 3 Boey scores were 13%, 45.7%, 70.7% and 73.3% respectively (p < 0.001). Boey score is a useful tool for assessing the prognosis of operated cases of peptic perforation and helps in the assessment of mortality and morbidity of these patients.

A Study of Seismic Wave Propagation at Regional Distances in Five Areas of the World

DTIC Science & Technology

1982-02-08

5.60 CA18 740425 08 56 42.8 17.195S 70.683W 29 5.20 CA20 740706 07 04 25.1 22.128S 64.294W 15 4.30 CA27 741031 08 58 20.9 15.438S 71.050W 50 5.00...earthquake with mb - 5. Natural earthquakes are denoted as circles and rock bursts as triangles, 7 Logarithmic plots of A/T (amplitudes divided by 29 periods...propagation paths are denoted by symbols shown in the legend. 29 Trace amplitudes of S in South America, plotted 61 n against epicentral distance

Safety of thoracic pedicle screw application using the funnel technique in Asians: a cadaveric evaluation.

PubMed

Chan, Chris Yin Wei; Kwan, Mun Keong; Saw, Lim Beng

2010-01-01

The objective of this cadaveric study is to determine the safety and outcome of thoracic pedicle screw placement in Asians using the funnel technique. Pedicle screws have superior biomechanical as well as clinical data when compared to other methods of instrumentation. However, misplacement in the thoracic spine can result in major neurological implications. There is great variability of the thoracic pedicle morphometry between the Western and the Asian population. The feasibility of thoracic pedicle screw insertion in Asians has not been fully elucidated yet. A pre-insertion radiograph was performed and surgeons were blinded to the morphometry of the thoracic pedicles. 240 pedicle screws were inserted in ten Asian cadavers from T1 to T12 using the funnel technique. 5.0 mm screws were used from T1 to T6 while 6.0 mm screws were used from T7 to T12. Perforations were detected by direct visualization via a wide laminectomy. The narrowest pedicles are found between T3 and T6. T5 pedicle width is smallest measuring 4.1 +/- 1.3 mm. There were 24 (10.0%) Grade 1 perforations and only 1 (0.4%) Grade 2 perforation. Grade 2 or worse perforation is considered significant perforation which would threaten the neural structures. There were twice as many lateral and inferior perforations compared to medial perforations. 48.0% of the perforations occurred at T1, T2 and T3 pedicles. Pedicle fracture occurred in 10.4% of pedicles. Intra-operatively, the absence of funnel was found in 24.5% of pedicles. In conclusion, thoracic pedicle screws using 5.0 mm at T1-T6 and 6.0 mm at T7-T12 can be inserted safely in Asian cadavers using the funnel technique despite having smaller thoracic pedicle morphometry.

77 FR 63725 - Drawbridge Operation Regulations; Old River, Orwood, CA

Federal Register 2010, 2011, 2012, 2013, 2014

2012-10-17

... BNSF Middle River drawbridge as an alternative path for navigation. DATES: The temporary deviation... Operation Regulation; Old River, Orwood CA'' in the Federal Register (77 FR 58491). The temporary deviation... Operation Regulations; Old River, Orwood, CA AGENCY: Coast Guard, DHS. ACTION: Notice of cancellation of a...

Mechanisms underlying activation of transient BK current in rabbit urethral smooth muscle cells and its modulation by IP3-generating agonists

PubMed Central

Kyle, Barry D.; Bradley, Eamonn; Large, Roddy; Sergeant, Gerard P.; McHale, Noel G.; Thornbury, Keith D.

2013-01-01

We used the perforated patch-clamp technique at 37°C to investigate the mechanisms underlying the activation of a transient large-conductance K+ (tBK) current in rabbit urethral smooth muscle cells. The tBK current required an elevation of intracellular Ca2+, resulting from ryanodine receptor (RyR) activation via Ca2+-induced Ca2+ release, triggered by Ca2+ influx through L-type Ca2+ (CaV) channels. Carbachol inhibited tBK current by reducing Ca2+ influx and Ca2+ release and altered the shape of spike complexes recorded under current-clamp conditions. The tBK currents were blocked by iberiotoxin and penitrem A (300 and 100 nM, respectively) and were also inhibited when external Ca2+ was removed or the CaV channel inhibitors nifedipine (10 μM) and Cd2+ (100 μM) were applied. The tBK current was inhibited by caffeine (10 mM), ryanodine (30 μM), and tetracaine (100 μM), suggesting that RyR-mediated Ca2+ release contributed to the activation of the tBK current. When IP3 receptors (IP3Rs) were blocked with 2-aminoethoxydiphenyl borate (2-APB, 100 μM), the amplitude of the tBK current was not reduced. However, when Ca2+ release via IP3Rs was evoked with phenylephrine (1 μM) or carbachol (1 μM), the tBK current was inhibited. The effect of carbachol was abolished when IP3Rs were blocked with 2-APB or by inhibition of muscarinic receptors with the M3 receptor antagonist 4-diphenylacetoxy-N-methylpiperidine methiodide (1 μM). Under current-clamp conditions, bursts of action potentials could be evoked with depolarizing current injection. Carbachol reduced the number and amplitude of spikes in each burst, and these effects were reduced in the presence of 2-APB. In the presence of ryanodine, the number and amplitude of spikes were also reduced, and carbachol was without further effect. These data suggest that IP3-generating agonists can modulate the electrical activity of rabbit urethral smooth muscle cells and may contribute to the effects of neurotransmitters on urethral tone. PMID:23804200

Fast track pathway for perforated appendicitis.

PubMed

Frazee, Richard; Abernathy, Stephen; Davis, Matthew; Isbell, Travis; Regner, Justin; Smith, Randall

2017-04-01

Perforated appendicitis is associated with an increased morbidity and length of stay. "Fast track" protocols have demonstrated success in shortening hospitalization without increasing morbidity for a variety of surgical processes. This study evaluates a fast track pathway for perforated appendicitis. In 2013, a treatment pathway for perforated appendicitis was adopted by the Acute Care Surgery Service for patients having surgical management of perforated appendicitis. Interval appendectomy was excluded. Patients were treated initially with intravenous antibiotics and transitioned to oral antibiotics and dismissed when medically stable and tolerating oral intake. A retrospective review of patients managed on the fast track pathway was undertaken to analyze length of stay, morbidity, and readmissions. Thirty-four males and twenty-one females with an average age of 46.8 years underwent laparoscopic appendectomy for perforated appendicitis between January 2013 and December 2014. Pre-existing comorbidities included hypertension 42%, diabetes mellitus 11%, COPD 5% and heart disease 2%. No patient had conversion to open appendectomy. Average length of stay was 2.67 days and ranged from 1 to 12 days (median 2 days). Postoperative morbidity was 20% and included abscess (6 patients), prolonged ileus (3 patients), pneumonia (1 patient), and congestive heart failure (1 patient). Five patients were readmitted for abscess (3 patients), congestive heart failure (1 patient), and pneumonia (1 patient). A fast track pathway for perforated appendicitis produced shorter length of stay and acceptable postoperative morbidity and readmission. This offers the potential for significant cost savings over current national practice patterns. Copyright © 2016 Elsevier Inc. All rights reserved.

Increased risk of cardiovascular perforation during ECMO with a bicaval, wire-reinforced cannula.

PubMed

Johnson, Sidney M; Itoga, Nathan; Garnett, Gwendolyn M; Kilcommons, Melody; Puapong, Devin P; Woo, Russell K

2014-01-01

Cardiac or major vascular perforation is a rare but serious risk of ECMO. We sought to determine if perforation rates are related to cannula design. We utilized three methods to evaluate perforation on ECMO. 1. The ELSO registry was queried to establish the historical rate of hemorrhagic pericardial tamponade. 2. ELSO centers were surveyed regarding cannula related perforation events and brands of cannulas used over a four year time period (January 2008-March 2012). 3. The FDA's MAUDE database was reviewed looking for adverse events related to ECMO cannulas. The historical rate of hemorrhagic pericardial tamponade in the ELSO registry was 0.53% (~1985-2010, ELSO registry). In the survey there were eleven reports of cannula-related perforation, 0.74% (11/1482 p-value=0.29) at 7 different ELSO centers with 23 ELSO centers responding (17% response rate). The incidence of perforation was much higher for the wire-reinforced bicaval design 3.6% (10/279) as compared to catheters designed for the atrial position, 0.1% (1/1203, p-value<0.0001). Review of the FDA's MAUDE database revealed 19 adverse events related to the bicaval cannula design, 16 of which were hemorrhagic pericardial effusions or tamponade. These findings suggest a relatively high rate of cardiac perforation associated with the dual lumen bicaval cannula. This may be related to inherent differences in cannula design or the IVC positioning required by the design. © 2014.

Risk factors for reintervention after surgery for perforated gastroduodenal ulcer.

PubMed

Hasselager, R B; Lohse, N; Duch, P; Møller, M H

2016-11-01

Perforated gastroduodenal ulcer carries a high mortality rate. Need for reintervention after surgical repair is associated with worse outcome, but knowledge on risk factors for reintervention is limited. The aim was to identify prognostic risk factors for reintervention after perforated gastroduodenal ulcer in a nationwide cohort. All patients treated surgically for perforated gastroduodenal ulcer in Denmark between 2003 and 2014 were included using data from the Danish Clinical Register of Emergency Surgery. Potential risk factors for reintervention were assessed, and their crude and adjusted associations calculated by the competing risks subdistribution hazards approach. A total of 4086 patients underwent surgery for perforated gastroduodenal ulcer during the study interval. Median age was 71·1 (i.q.r. 59·6-81·0) years and the overall 90-day mortality rate was 30·8 per cent (1258 of 4086). Independent risk factors for reintervention were: male sex (adjusted hazard ratio (HR) 1·46, 95 per cent c.i. 1·20 to 1·78), in-hospital perforation (adjusted HR 1·36, 1·11 to 1·68), high BMI (adjusted HR 1·49, 1·10 to 2·01), high ASA physical status grade (adjusted HR 1·54, 1·23 to 1·94), shock on admission (adjusted HR 1·40, 1·13 to 1·74), surgical delay (adjusted HR 1·07, 1·02 to 1·14) and other co-morbidity (adjusted HR 1·24, 1·02 to 1·51). Preadmission use of steroids (adjusted HR 0·59, 0·41 to 0·84) and age above 70 years (adjusted HR 0·72, 0·59 to 0·89) were associated with a reduced risk of reoperation. Obese men with coexisting diseases and high disease severity who have surgery for gastroduodenal perforation are at increased risk of reoperation. © 2016 BJS Society Ltd Published by John Wiley & Sons Ltd.

Non-ossicular signal transmission in human middle ears: Experimental assessment of the “acoustic route” with perforated tympanic membranes

PubMed Central

Voss, Susan E.; Rosowski, John J.; Merchant, Saumil N.; Peake, William T.

2008-01-01

Direct acoustic stimulation of the cochlea by the sound-pressure difference between the oval and round windows (called the “acoustic route”) has been thought to contribute to hearing in some pathological conditions, along with the normally dominant “ossicular route.” To determine the efficacy of this acoustic route and its constituent mechanisms in human ears, sound pressures were measured at three locations in cadaveric temporal bones [with intact and perforated tympanic membranes (TMs)]: (1) in the external ear canal lateral to the TM, PTM; (2) in the tympanic cavity lateral to the oval window, POW; and (3) near the round window, PRW. Sound transmission via the acoustic route is described by two concatenated processes: (1) coupling of sound pressure from ear canal to middle-ear cavity, HPCAV≡PCAV/PTM, where PCAV represents the middle-ear cavity pressure, and (2) sound-pressure difference between the windows, HWPD≡(POW−PRW)/PCAV. Results show that: HPCAV depends on perforation size but not perforation location; HWPD depends on neither perforation size nor location. The results (1) provide a description of the window pressures based on measurements, (2) refute the common otological view that TM perforation location affects the “relative phase of the pressures at the oval and round windows,” and (3) show with an intact ossicular chain that acoustic-route transmission is substantially below ossicular-route transmission except for low frequencies with large perforations. Thus, hearing loss from TM perforations results primarily from reduction in sound coupling via the ossicular route. Some features of the frequency dependence of HPCAV and HWPD can be interpreted in terms of a structure-based lumped-element acoustic model of the perforation and middle-ear cavities. PMID:17902851

Phase transformation upon cooling path in Ca2SiO4: Possible geological implication

NASA Astrophysics Data System (ADS)

Chang, Yun-Ting; Kung, Jennifer; Hsu, Han

2016-04-01

At the contact metamorphism zone two different Ca2SiO4 phases can be found; calcio-olivine (γ phase) and larnite (β phase). In-situ experiments illustrated the existence of five various polymorphs in Ca2SiO4, i.e., α, α'H, α'L, β and γ. The path of phase transformation and the transformation temperatures are shown as follows. γ → α'L(700° C) → α'H(1100° C) → α (1450° C) α'L → β (680° C) → γ (500° C) Experiments showed that the phase transitions at lower temperature is not reversible and seemed to be complicated; β phase is only stable from 500° C to 680° C upon cooling. To understand the possible mechanism of the β phase being metastable at room temperature, atmosphere condition, we were motivated to investigate the route of phase transition in Ca2SiO4 in different thermal process. Powder samples were synthesized by the solid-state reaction. Pure reagent oxides CaCO3 and SiO2 were mixed in 2:1 stoichiometric mole. Two control factors were designated in the experiments; the sintering temperature of starting materials and the cooling path. The sintering temperature was set within the range of stable phase field of α'L phase (˜900° C) and α'H phase (1300° C). The cooling process was designed in three different routes: 1) the quenched procedure from sintering temperature with rate of 900° C/min and 1300° C/min, 2) the furnace cooling procedure, 3) set a slow cooling rate (0.265 ° C/min). The products were examined for the crystal structure by X-ray powder diffraction. First-principle calculation was also applied to investigate the thermodynamic properties of α'H, β and γ phases. A major finding in this study showed that the γ phase presented in the final product when the sintering temperature was set at the stable field of α'H phase; on the other hand, the β phase would present when the sintering temperature was set within the field of α'L phase. It was noted that the existing phase in the product would be modified by the cooling procedures. Our calculation indicates the enthalpy of beta phase was slightly higher than that of the gamma phase at zero pressure, verifying the metastable β phase observed in the natural. In this meeting we present the detailed experimental results and discuss the potential implication for the thermal history of geological setting using the phase transition path upon cooling of Ca2SiO4.

Study of the Q branch structure of the 14N and 15N isotopologues of the ν4 band of ammonia using frequency chirped quantum cascade lasers.

PubMed

Duxbury, Geoffrey; Wilson, David; Hay, Kenneth; Langford, Nigel

2013-10-03

Intrapulse quantum cascade (QC) laser spectrometers are able to produce both saturation and molecular alignment of a gas sample owing to the rapid sweep of the radiation through the absorption features. In the QC lasers used to study the (14)N and (15)N isotopologues of the ν4 band of ammonia centered near 1625 cm(-1), the variation of the chirp rate during the scan is very large, from ca. 85 to ca. 15 MHz ns(-1). In the rapid chirp zone the collisional interaction time of the laser radiation with the gas molecules is short, and large rapid passage effects are seen, whereas at the slow chirp end the line shape resembles that of a Doppler broadened line. The total scan range of the QC laser of ca. 10 cm(-1) is sufficient to allow the spectra of both isotopologues to be recorded and the rapid and slow interactions with the laser radiation to be seen. The rapid passage effects are enhanced by the use of an off axis Herriott cell with an effective path length of 62 m, which allows a buildup of polarization to occur. The effective resolution of the chirped QC laser is ca. 0.012 cm(-1) full width at half-maximum in the 1625 cm(-1) region. The results of these experiments are compared with those of other studies of the ν4 band of ammonia carried out using Fourier transform and Laser Stark spectroscopy. They also demonstrate the versatility of the down chirped QC laser for investigating collisional effects in low pressure gases using long absorbing path lengths.

Changes in the localization of perforated peptic ulcer and its relation to gender and age of the patients throughout the last 45 years.

PubMed

Wysocki, Andrzej; Budzyński, Piotr; Kulawik, Jan; Drożdż, Włodzimierz

2011-04-01

Throughout recent decades there has been noticeable change in the incidence of peptic ulcer disease and its complications. The aim of the present study was to determine the character of changes over the last 45 years in the localization of perforation, in patient age, and in patient gender. A group of 881 patients admitted to the Second Department of General Surgery in Krakow, Poland, from 1962 to 2006 were included in the study and constituted the material for the analysis. The study was divided into three time periods (1962-1976, 1977-1991, and 1992-2006) to allow statistical analysis of trends. The general incidence of perforations of peptic ulcer did not show changes; however, the percentage of women with perforated duodenal ulcer markedly increased. Patients with perforated stomach ulcer--regardless of gender--and females suffering from perforated duodenal ulcer were, on the average, about 10 years older than males with perforated duodenal ulcers. The mean age of male and female patients with perforated duodenal ulcer over the last 45 years showed an insignificant upward trend. (1) The percentage of women with perforated duodenal ulcer continuously and statistically significantly rose. (2) Men with perforated duodenal ulcer were significantly younger than other patients. (3) The mean ages of male and female patients with perforated duodenal ulcer over the last 45 years showed an insignificant upward trend.

PRESENTATION AND MANAGEMENT OF PERFORATED PEPTIC ULCER DISEASE IN A TERTIARY CENTRE IN SOUTH SOUTH NIGERIA.

PubMed

Dodiyi-Manuel, A; Wichendu, P N; Enebeli, V C

2015-01-01

Perforations of the stomach and duodenum are common complications of peptic ulcer disease (PUD), abuse of non steroidal anti inflammatory drugs (NSAIDS) and gastric cancer. Being a life threatening complication of PUD, it needs special attention with prompt resuscitation and appropriate surgical management if morbidity and mortality are to be avoided. To determine the pattern and management outcome of perforated peptic ulcer disease PUD as seen in University of Port Harcourt Teaching Hospital (UPTH), Port Harcourt, Rivers State, Nigeria). All the patients with perforated PUD that were managed at UPTH between January 2006 and December 2014 were studied. Relevant data were extracted from the case notes and analysed using the Statistical Package for Social Sciences (SPSS) version 17. Thirty six patients with perforated PUD were evaluated consisting of 28 males and 8 females with a male to female ratio of 3.5:1. Their ages ranged from 24 to 65 years with a mean of 42.1± 12.3 years and the peak age was at the third decade. After adequate resuscitation, all the patients had exploratory laparotomy. In 26 (72.2%) patients, the perforation was in the duodenum while in 10 (27.8%), it was in the stomach. Thirty two (88.9%) patients had Graham's omental patch repair of the perforation while simple closure only was done in 4 (11.1%) patients. Surgical site infection was the commonest post operative complication which was seen in 7 (19.4%) patients while 4 patients died giving a mortality rate of 11.1%. Perforated peptic ulcer predominantly affected young males and Graham's omental patch followed by Helicobacter pylori eradication was an effective treatment modality.

Evaluation of three-dimensional computed tomography processing for deep inferior epigastric perforator flap breast reconstruction.

PubMed

Teoh, Raymond; Johnson, Raleigh F; Nishino, Thomas K; Ethridge, Richard T

2007-01-01

The deep inferior epigastric perforator flap procedure has become a popular alternative for women who require breast reconstruction. One of the difficulties with this procedure is identifying perforator arteries large enough to ensure that the harvested tissue is well vascularized. Current techniques involve imaging the perforator arteries with computed tomography (CT) to produce a grid mapping the locations of the perforator arteries relative to the umbilicus. To compare the time it takes to produce a map of the perforators using either two-dimensional (2D) or three-dimensional (3D) CT, and to see whether there is a benefit in using a 3D model. Patient CT abdomen and pelvis scans were acquired from a GE 64-slice scanner. CT image processing was performed with the GE 3D Advantage Workstation v4.2 software. Maps of the perforators were generated both as 2D and 3D representations. Perforators within a region 5 cm rostral and 7 cm caudal to the umbilicus were measured and the times to perform these measurements using both 2D and 3D images were recorded by a stopwatch. Although the 3D method took longer than the 2D method (mean [+/- SD] time 1:51+/-0:35 min versus 1:08+/-0:16 min per perforator artery, respectively), producing a 3D image provides much more information than the 2D images alone. Additionally, an actual-sized 3D image can be printed out, removing the need to make measurements and producing a grid. Although it took less time to create a grid of the perforators using 2D axial CT scans, the 3D reconstruction of the abdomen allows the plastic surgeons to better visualize the patient's anatomy and has definite clinical utility.

Impact of COPD on outcome among patients with complicated peptic ulcer.

PubMed

Christensen, Steffen; Thomsen, Reimar W; Tørring, Marie Louise; Riis, Anders; Nørgaard, Mette; Sørensen, Henrik T

2008-06-01

COPD is associated with an increased risk of peptic ulcer disease, but limited data exist on whether COPD influences short-term mortality among patients with bleeding and a perforated peptic ulcer. We examined the association between COPD and 30-day mortality following bleeding and perforation of a peptic ulcer. We identified all patients who had been hospitalized with a first-time diagnosis of peptic ulcer perforation (n = 2,033) or bleeding (n = 7,486) in northern Denmark between 1991 and 2004. Information on COPD, comorbidities, and filled prescriptions was obtained from medical databases. Mortality was ascertained using the Danish Civil Registration System. We computed the cumulative 30-day mortality rates for ulcer patients with COPD and for other ulcer patients, and used regression analysis to obtain the 30-day mortality rate ratios (MRRs), controlling for potential confounding factors. Among patients who were hospitalized with perforated peptic ulcers, 218 (10.7%) had previously been hospitalized with COPD. The 30-day mortality rate was 44.0% among perforated ulcer patients with COPD vs 25.5% among other ulcer patients (adjusted MRR, 1.48; 95% confidence interval [CI], 1.18 to 1.85). Among patients hospitalized with a bleeding peptic ulcer, 759 (10.1%) had previously been hospitalized with COPD. The 30-day mortality rate was 16.5% among bleeding peptic ulcer patients with COPD vs 10.8% among other ulcer patients (adjusted MRR, 1.38; 95% CI, 1.14 to 1.68). The use of oral glucocorticoids among COPD patients was associated with higher MRRs for both perforated and bleeding peptic ulcers. COPD substantially increased 30-day mortality among patients with bleeding and perforated peptic ulcers.

Small Tympanic Membrane Perforations in the Inferior Quadrants Do Not Impact the Manubrium Vibration in Guinea Pigs

PubMed Central

Zhang, Xiuling; Dai, Yanhong; Zhang, Shuyi; She, Wandong; Du, Xiaoping; Shui, Xiuji

2012-01-01

Background It has been believed that location of the perforation has a significant impact on hearing loss. However, recent studies have demonstrated that the perforation sites had no impact on hearing loss. We measured the velocity and pattern of the manubrium vibration in guinea pigs with intact and perforated eardrum using a laser Doppler vibrometer in order to determine the effects of different location perforations on the middle ear transfer functions. Methods Two bullas from 2 guinea pigs were used to determine stability of the umbo velocities, and 12 bullas from six guinea pigs to determine the effects of different location perforations on sound transmission. The manubrium velocity was measured at three points on the manubrium in the frequencies of 0.5–8 kHz before and after a perforation was made. The sites of perforations were in anterior-inferior (AI) quadrants of left ears and posterior-inferior (PI) quadrants of right ears. Results The manubrium vibration velocity losses were noticed in the perforated ears only below 1.5 kHz. The maximum velocity loss was about 7 dB at 500 Hz with the PI perforation. No significant difference in the velocity loss was found between AI and PI perforations. The average ratio of short process velocity to the umbo velocity was approximately 0.5 at all frequencies. No significant differences were found before and after perforation at all frequencies (p>0.05) except 7 kHz (p = 0.004) for both AI and PI perforations. Conclusions The manubrium vibration velocity losses from eardrum perforation were frequency-dependent and the largest losses occur at low frequencies. Manubrium velocity losses caused by small acute inferior perforations in guinea pigs have no significant impact on middle ear sound transmission at any frequency tested. The manubrium vibration axis may be perpendicular to the manubrium below 8 kHz in guinea pigs. PMID:22238584

Effect of packaging conditions on the growth of micro-organisms and the quality characteristics of fresh mushrooms (Agaricus bisporus) stored at inadequate temperatures.

PubMed

González-Fandos, E; Giménez, M; Olarte, C; Sanz, S; Simón, A

2000-10-01

Mushrooms were packed in two polymeric films (perforated and non-perforated PVC) and stored at 17 degrees C and 25 degrees C. The carbon dioxide and oxygen content inside the packages, aerobic mesophiles, Pseudomonas spp., faecal coliforms, Escherichia coli, anaerobic spores and major sensory factors (colour, texture, development stage and presence of moulds) were determined. The non-perforated packages had the highest contents of CO2 (6-7%), the lowest contents of O2 (0.013-0.17%) and the most desirable quality parameters (texture, development stage and absence of moulds). Pseudomonas spp. counts were around 1 logarithmic unit lower in mushrooms packaged in non-perforated film as the O2 concentrations were lower than in perforated film. The mushrooms themselves were inoculated with an enterotoxin A-producing strain of Staphylococcus aureus, packaged in overwrapped trays and stored at 17 and 25 degrees C. Staphylococcus aureus did not grow in the samples stored at 17 degrees C. Only slight growth was observed in mushrooms packaged with non-perforated film after 1 day at 25 degrees C. No enterotoxin was detected in any package. Faecal coliform counts were <2 log cfu g(-1). Escherichia coli was not isolated in any of the samples. At 25 degrees C, counts of anaerobic spores of around 2 log cfu g(-1) were detected in those mushrooms packaged in non-perforated film.

Tumor-Cut: segmentation of brain tumors on contrast enhanced MR images for radiosurgery applications.

PubMed

Hamamci, Andac; Kucuk, Nadir; Karaman, Kutlay; Engin, Kayihan; Unal, Gozde

2012-03-01

In this paper, we present a fast and robust practical tool for segmentation of solid tumors with minimal user interaction to assist clinicians and researchers in radiosurgery planning and assessment of the response to the therapy. Particularly, a cellular automata (CA) based seeded tumor segmentation method on contrast enhanced T1 weighted magnetic resonance (MR) images, which standardizes the volume of interest (VOI) and seed selection, is proposed. First, we establish the connection of the CA-based segmentation to the graph-theoretic methods to show that the iterative CA framework solves the shortest path problem. In that regard, we modify the state transition function of the CA to calculate the exact shortest path solution. Furthermore, a sensitivity parameter is introduced to adapt to the heterogeneous tumor segmentation problem, and an implicit level set surface is evolved on a tumor probability map constructed from CA states to impose spatial smoothness. Sufficient information to initialize the algorithm is gathered from the user simply by a line drawn on the maximum diameter of the tumor, in line with the clinical practice. Furthermore, an algorithm based on CA is presented to differentiate necrotic and enhancing tumor tissue content, which gains importance for a detailed assessment of radiation therapy response. Validation studies on both clinical and synthetic brain tumor datasets demonstrate 80%-90% overlap performance of the proposed algorithm with an emphasis on less sensitivity to seed initialization, robustness with respect to different and heterogeneous tumor types, and its efficiency in terms of computation time.

Thrust exhumation of the Southern Marginal Zone of the Limpopo Complex in the Neoarchaean: link of distinct high-grade shear zones with DC and IC P-T-t paths

NASA Astrophysics Data System (ADS)

Smit, C. Andre; van Reenen, Dirk D.

2010-05-01

The Limpopo Complex is a ~750km long E-W trending zone of predominantly granulite facies rocks situated between the Archaean Kaapvaal and Zimbabwe cratons of southern Africa. Large ductile shear zones are an integral part of the Limpopo architecture, defining the boundaries between the belt and the adjacent cratons and are interpreted to have been responsible for uplift (exhumation) of over thickened crust during the Neoarchaean [10 and references therein; 1]. The Hout River Shear Zone forms the terrane boundary between the granite-greenstone terrane of the Kaapvaal craton in the south and the high-grade Southern Marginal Zone (SMZ) of the Limpopo Complex in the north. Integrated structural, metamorphic, magmatic and age data collected over a period of more than 30 years provide convincing evidence for a Neoarchean high-grade tectono-metamorphic event that affected the SMZ in the interval ~2.72 - 2.60 Ga [4; 5, 6; 7; 2; 8; 9; 11]. The thrust-controlled exhumation of the SMZ is demonstrated by the convergence of a retrograde P-T path in the hanging wall (SMZ) and a prograde P-T loop in the footwall (Kaapvaal Craton) of the steeply SW-verging Hout River Shear Zone [4; 5]. The coeval ages (~2.69 Ga) of the two contrasting metamorphic histories are indicated by geochronological data [2; 3]. In addition, the establishment of a retrograde isograd and zone of rehydrated granulites in the hanging wall by hydrous CO2-rich fluids derived by dehydration of the low-grade rocks in the footwall provides another convincing link between the two contrasting metamorphic environments [10]. Distinct retrograde P-T paths [4; 6; 8] linked to distinct shear deformational events document evidence for a two-stage post-peak exhumation history of the SMZ: (i) granulites sampled far from the contact with the cool rocks of the Kaapvaal Craton are characterized by P-T paths with two distinct decompression-cooling (DC) stages (DC=>DC paths), (ii) granulites sampled close to this contact are characterized by P-T paths with an inflection that reflects near-isobaric cooling (IC) (DC=>IC paths). The early (2.69-2.664Ga) DC stage (P ~8 kbar, T ~825oC to P ~6.5 kbar, T ~750oC) of exhumation is linked to the transportation of the high-grade rocks up the steep ramp section of the Hout River Shear Zone that controlled their emplacement to upper crustal levels. The later (~2.62-2.6Ga) near-IC stage (P ~6.5kbar, T ~700oC to P ~ 5kbar, T ~500oC) of exhumation is linked to the flat section of SW-verging thrusts that reflect the emplacement of the high-grade rocks over the cool rocks of the adjacent craton. These low-angle thrusts also account for the presence of high-grade klippen [10] located on the craton far south of the Hout River Shear Zone. Peak UHT metamorphic conditions (T > 900oC at P > 10kbar) recently reported for the SMZ [9] might have been reached at ~2.72 Ga, as is suggested by shallow northerly verging ~2.72Ga thrusts on the Kaapvaal Craton [3]. These thrusts, which are truncated by the steeply SW-verging ~2.69Ga Hout River Shear Zone are probably linked to a crustal thickening event that controlled the initial burial of SMZ granulites to depths >30 km. Integrated D-P-T-t paths constructed for hanging wall granulites and footwall greenstones provide evidence in support of a tectonic model for the evolution of the SMZ (and of the Limpopo Complex as a whole) that is either linked to a crustal thickening event involving the collision in the Neoarchean of the Kaapvaal and Zimbabwe cratons [10] or to a gravitational redistribution model [1]. References: [1] Gerya, T.V., Perchuk, L.L., Van Reenen, D.D., and Smit, C.A. 2000. J. Geodynamics, 30, 17-35. [2] Kreissig, K., Holzer, L., Frei, R., Villa, I.M., Kramers, J.D., Smit, C.A., and Van Reenen, D.D. 2001. Precambrian Resarch, 109, 145-173. [3] Passeraub, M., Wuest, T., Kreissig, K., Smit, C.A., Kramers, J.D. 1999. S. Afr. J. Geology 102, n.4, 323-334. [4] Perchuk, L.L., Gerya., T.V., Van Reenen, D.D., Sefanov, O.G., and Smit, C.A. 1996. Petrology, 4, 571-599. [5] Perchuk, L.L., Gerya, T.V., Van Reenen, D.D., Smit, C.A., Krotov, A.V., and Safanov, O.G. 2000. Mineralogy and Petrology, 69, 69-108 [6] Perchuk, L.L., Gerya, T.V., Van Reenen, D.D., Smit, C.A., and Krotov, A.V. 2000. Min. Pet, 69, 109-141. [7] Perchuk, L.L., Gerya, T.V., Van Reenen, D.D., and Smit, C.A., 2001. Gondwana Research, 4, 729-732. [8] Smit, C.A., Van Reenen, D.D, Gerya, T.V., and Perchuk, L.L. 2001. J. Metamorphic Geololgy, 19, 249-268. [9] Tsunogae,T., Miyano, T., Van Reenen, D. D., and Smit, C.A., 2004. J. Mineralogy and Petrology, 99, 213-224. [10] Van Reenen, D.D., Roering, C., Ashwal, L.D., and de Wit, M.J. 1992 (Eds). Precambrian Research, 55, 1-587.

50 CFR 216.154 - Mitigation.

Code of Federal Regulations, 2010 CFR

2010-10-01

... Of Marine Mammals Incidental To Missile Launch Activities from San Nicolas Island, CA § 216.154... haul-out sites below the missile's predicted flight path for 2 hours prior to planned missile launches... must not launch missiles from the Alpha Complex at low elevation (less than 1,000 feet (305 m)) on...

50 CFR 216.154 - Mitigation.

Code of Federal Regulations, 2011 CFR

2011-10-01

... Of Marine Mammals Incidental To Missile Launch Activities from San Nicolas Island, CA § 216.154... haul-out sites below the missile's predicted flight path for 2 hours prior to planned missile launches... must not launch missiles from the Alpha Complex at low elevation (less than 1,000 feet (305 m)) on...

50 CFR 216.154 - Mitigation.

Code of Federal Regulations, 2012 CFR

2012-10-01

... Of Marine Mammals Incidental To Missile Launch Activities from San Nicolas Island, CA § 216.154... haul-out sites below the missile's predicted flight path for 2 hours prior to planned missile launches... must not launch missiles from the Alpha Complex at low elevation (less than 1,000 feet (305 m)) on...

50 CFR 216.154 - Mitigation.

Code of Federal Regulations, 2013 CFR

2013-10-01

... Of Marine Mammals Incidental To Missile Launch Activities from San Nicolas Island, CA § 216.154... haul-out sites below the missile's predicted flight path for 2 hours prior to planned missile launches... must not launch missiles from the Alpha Complex at low elevation (less than 1,000 feet (305 m)) on...

How do tympanic-membrane perforations affect human middle-ear sound transmission?

PubMed

Voss, S E; Rosowski, J J; Merchant, S N; Peake, W T

2001-01-01

Although tympanic-membrane (TM) perforations are common sequelae of middle-ear disease, the hearing losses they cause have not been accurately determined, largely because additional pathological conditions occur in these ears. Our measurements of acoustic transmission before and after making controlled perforations in cadaver ears show that perforations cause frequency-dependent loss that: (1) is largest at low frequencies; (2) increases as perforation size increases; and (3) does not depend on perforation location. The dominant loss mechanism is the reduction in sound-pressure difference across the TM. Measurements of middle-ear air-space sound pressures show that transmission via direct acoustic stimulation of the oval and round windows is generally negligible. A quantitative model predicts the influence of middle-ear air-space volume on loss; with larger volumes, loss is smaller.

A comparison of the surgical mortality due to colorectal perforation at different hospitals with data from 10,090 cases in the Japanese National Clinical Database.

PubMed

Ohki, Takeshi; Yamamoto, Masakazu; Miyata, Hiroaki; Sato, Yasuto; Saida, Yoshihisa; Morimoto, Tsuyoshi; Konno, Hiroyuki; Seto, Yasuyuki; Hirata, Koichi

2017-01-01

Colorectal perforation has a high rate of mortality. We compared the incidence and fatality rates of colorectal perforation among different hospitals in Japan using data from the nationwide surgical database.Patients were registered in the National Clinical Database (NCD) between January 1st, 2011 and December 31st, 2013. Patients with colorectal perforation were identified from surgery records by examining if acute diffuse peritonitis (ADP) and diseases associated with a high probability of colorectal perforation were noted. The primary outcome measures included the 30-day postsurgery mortality and surgical mortality of colorectal perforation. We analyzed differences in the observed-to-expected mortality (O/E) ratio between the two groups of hospitals, that is, specialized and non-specialized, using the logistic regression analysis forward selection method.There were 10,090 cases of disease-induced colorectal perforation during the study period. The annual average postoperative fatality rate was 11.36%. There were 3884 patients in the specialized hospital group and 6206 in the non-specialized hospital group. The O/E ratio (0.9106) was significantly lower in the specialized hospital group than in the non-specialized hospital group (1.0704). The experience level of hospitals in treating cases of colorectal perforation negatively correlated with the O/E ratio.We conducted the first study investigating differences among hospitals with respect to their fatality rate of colorectal perforation on the basis of data from a nationwide database. Our data suggest that patients with colorectal perforation should choose to be treated at a specialized hospital or a hospital that treats five or more cases of colorectal perforation per year. The results of this study indicate that specialized hospitals may provide higher quality medical care, which in turn proves that government policy on healthcare is effective at improving the medical system in Japan.

Perforated marginal ulcers after laparoscopic gastric bypass.

PubMed

Felix, Edward L; Kettelle, John; Mobley, Elijah; Swartz, Daniel

2008-10-01

Perforated marginal ulcer (PMU) after laparoscopic Roux-en-Y gastric bypass (LRYGB) is a serious complication, but its incidence and etiology have rarely been investigated. Therefore, a retrospective review of all patients undergoing LRYGB at the authors' center was conducted to determine the incidence of PMU and whether any causative factors were present. A prospectively kept database of all patients at the authors' bariatric center was retrospectively reviewed. The complete records of patients with a PMU were examined individually for accuracy and analyzed for treatment, outcome, and possible underlying causes of the marginal perforation. Between April 1999 and August 2007, 1% of the patients (35/3,430) undergoing laparoscopic gastric bypass experienced one or more perforated marginal ulcers 3 to 70 months (median, 18 months) after LRYGB. The patients with and without perforation were not significantly different in terms of mean age (37 vs 41 years), weight (286 vs 287 lb), body mass index (BMI) (46 vs 47), or female gender (89% vs 83%). Of the patients with perforations, 2 (6%) were taking steroids, 10 (29%) were receiving nonsteroidal antiinflammatory drugs (NSAIDs) at the time of the perforation, 18 (51%) were actively smoking, and 6 of the smokers also were taking NSAIDs. Eleven of the patients (31%) who perforated did not have at least one of these possible risk factors, but 4 (36%) of the 11 patients in this group had been treated after bypass for a marginal ulcer. Only 7 (20%) of the 35 patients who had laparoscopic bypass, or 7 (0.2%) in the entire group of 3,430 patients, perforated without any warning. There were no deaths, but three patients reperforated. The incidence of a marginal ulcer perforating after LRYGB was significant (>1%) and appeared to be related to smoking or the use of NSAIDs or steroids. Because only 0.2% of all patients acutely perforated without some risk factor or warning, long-term ulcer prophylaxis or treatment may be necessary for only a select group of high-risk patients.

Efficiency of depleted UO2 based semiconductor neutron detectors in direct and indirect configuration—A GEANT4 simulation study

NASA Astrophysics Data System (ADS)

Parida, M. K.; Prabakar, K.; Sundari, S. T.

2018-03-01

In the present work, Monte Carlo simulations using GEANT4 are carried out to estimate the efficiency of semiconductor neutron detectors with depleted UO2 (DUO2) as converter material, in both planar (direct and indirect) and 3D geometry (cylindrical perforation and trenches structure) configurations. The simulations were conducted for neutrons of variable energy viz., thermal (25 meV) and fast (1 to 10 MeV) that were incident on varying thicknesses (0.25 μm to 1000 μm), diameters (1 μm to 9 μm) and widths (1 μm to 9 μm) along with depths (50 μm to 275 μm) of DUO2 for planar, cylindrical perforated and trench structures, respectively. In the case of direct planar detectors, efficiency was found to increase with the thickness of DUO2 and the rate at which efficiency increased was found to follow the macroscopic fission cross section at the corresponding neutron energy. In the case of indirect planar detector, efficiency was lower as compared to direct configuration and was found to saturate beyond a thickness of ~3 μm. This saturation is explained on the basis of mean free path of neutrons in the DUO2 material. For the 3D perforated silicon detectors of cylindrical (trench) geometry, backfilled with DUO2, the efficiency for detection of thermal neutrons ~25 meV and fast neutrons ~ typical energy of 10 MeV was found to be ~0.0159% (~0.0177%) and ~0.0088% (0.0098%), respectively. These efficiency values were two (one) order values higher than planar indirect detector for thermal (fast) neutrons. Histogram plots were also obtained from the GEANT4 simulations to monitor the energy distribution of fission products in planar (direct and indirect) and 3D geometry (cylindrical and trench) configurations. These plots revealed that, for all the detector configurations, the energy deposited by the fission products are higher as compared to the typical gamma ray background. Thus, for detectors with DUO2 as converter material, higher values of low level discriminator (LLD) can be set, so as to achieve good background discrimination.

Delayed lead perforation: a disturbing trend.

PubMed

Khan, Mohammed N; Joseph, George; Khaykin, Yaariv; Ziada, Khaled M; Wilkoff, Bruce L

2005-03-01

Delayed lead perforation (occurring more than 1 month after implantation) is a rare complication. Its pathophysiology and optimal management are currently unclear. Three cases of delayed lead perforation (6-10 month) were identified in patients with low-profile active fixation leads. All cases presented in a subacute fashion with pleuritic chest pain with confirmatory chest x-ray and device interrogation. Given the potential complications of a perforated lead, all cases had the lead extracted under TEE observation with cardiac surgery backup in the operating room. All patients tolerated extraction without complication. Based on these cases, we recommend a management scheme for patients who present with delayed lead perforation.

Three-point bending of honeycomb sandwich beams with facesheet perforations

NASA Astrophysics Data System (ADS)

Su, Pengbo; Han, Bin; Zhao, Zhongnan; Zhang, Qiancheng; Lu, Tian Jian

2017-12-01

A novel square honeycomb-cored sandwich beam with perforated bottom facesheet is investigated under three-point bending, both analytically and numerically. Perforated square holes in the bottom facesheet are characterized by the area ratio of the hole to intact facesheet (perforation ratio). While for large-scale engineering applications like the decks of cargo vehicles and transportation ships, the perforations are needed to facilitate the fabrication process (e.g., laser welding) as well as service maintenance, it is demonstrated that these perforations, when properly designed, can also enhance the resistance of the sandwich to bending. For illustration, fair comparisons among competing sandwich designs having different perforation ratios but equal mass is achieved by systematically thickening the core webs. Further, the perforated sandwich beam is designed with a relatively thick facesheet to avoid local indention failure so that it mainly fails in two competing modes: (1) bending failure, i.e., yielding of beam cross-section and buckling of top facesheet caused by bending moment; (2) shear failure, i.e., yielding and buckling of core webs due to shear forcing. The sensitivity of the failure loads to the ratio of core height to beam span is also discussed for varying perforation ratios. As the perforation ratio is increased, the load of shear failure increases due to thickening core webs, while that of bending failure decreases due to the weakening bottom facesheet. Design of a sandwich beam with optimal perforation ratio is realized when the two failure loads are equal, leading to significantly enhanced failure load (up to 60% increase) relative to that of a non-perforated sandwich beam with equal mass.

Ca, Sr, O and D isotope approach to defining the chemical evolution of hydrothermal fluids: example from Long Valley, CA, USA

USGS Publications Warehouse

Brown, Shaun T.; Kennedy, B. Mack; DePaolo, Donald J.; Hurwitz, Shaul; Evans, William C.

2013-01-01

We present chemical and isotopic data for fluids, minerals and rocks from the Long Valley meteoric-hydrothermal system. The samples encompass the presumed hydrothermal upwelling zone in the west moat of the caldera, the Casa Diablo geothermal field, and a series of wells defining a nearly linear, ∼16 km long, west-to-east trend along the likely fluid flow path. Fluid samples were analyzed for the isotopes of water, Sr, and Ca, the concentrations of major cations and anions, alkalinity, and total CO2. Water isotope data conform to trends documented in earlier studies, interpreted as indicating a single hydrothermal fluid mixing with local groundwater. Sr isotopes show subtle changes along the flow path, which requires rapid fluid flow and minimal reaction between the channelized fluids and the wallrocks. Sr and O isotopes are used to calculate fracture spacing using a dual porosity model. Calculated fracture spacing and temperature data for hydrothermal fluids indicate the system is (approximately) at steady-state. Correlated variations among total CO2, and the concentration and isotopic composition of Ca suggest progressive fluid degassing (loss of CO2), which drives calcite precipitation as the fluid flows west-to-east and cools. The shifts in Ca isotopes require that calcite precipitated at temperatures of 150–180 °C is fractionated by ca. −0.3‰ to −0.5‰ relative to aqueous species. Our data are the first evidence that Ca isotopes undergo kinetic fractionation at high temperatures (>100 °C) and can be used to trace calcite precipitation along hydrothermal fluid flow paths.

Path integrals with higher order actions: Application to realistic chemical systems

NASA Astrophysics Data System (ADS)

Lindoy, Lachlan P.; Huang, Gavin S.; Jordan, Meredith J. T.

2018-02-01

Quantum thermodynamic parameters can be determined using path integral Monte Carlo (PIMC) simulations. These simulations, however, become computationally demanding as the quantum nature of the system increases, although their efficiency can be improved by using higher order approximations to the thermal density matrix, specifically the action. Here we compare the standard, primitive approximation to the action (PA) and three higher order approximations, the Takahashi-Imada action (TIA), the Suzuki-Chin action (SCA) and the Chin action (CA). The resulting PIMC methods are applied to two realistic potential energy surfaces, for H2O and HCN-HNC, both of which are spectroscopically accurate and contain three-body interactions. We further numerically optimise, for each potential, the SCA parameter and the two free parameters in the CA, obtaining more significant improvements in efficiency than seen previously in the literature. For both H2O and HCN-HNC, accounting for all required potential and force evaluations, the optimised CA formalism is approximately twice as efficient as the TIA formalism and approximately an order of magnitude more efficient than the PA. The optimised SCA formalism shows similar efficiency gains to the CA for HCN-HNC but has similar efficiency to the TIA for H2O at low temperature. In H2O and HCN-HNC systems, the optimal value of the a1 CA parameter is approximately 1/3 , corresponding to an equal weighting of all force terms in the thermal density matrix, and similar to previous studies, the optimal α parameter in the SCA was ˜0.31. Importantly, poor choice of parameter significantly degrades the performance of the SCA and CA methods. In particular, for the CA, setting a1 = 0 is not efficient: the reduction in convergence efficiency is not offset by the lower number of force evaluations. We also find that the harmonic approximation to the CA parameters, whilst providing a fourth order approximation to the action, is not optimal for these realistic potentials: numerical optimisation leads to better approximate cancellation of the fifth order terms, with deviation between the harmonic and numerically optimised parameters more marked in the more quantum H2O system. This suggests that numerically optimising the CA or SCA parameters, which can be done at high temperature, will be important in fully realising the efficiency gains of these formalisms for realistic potentials.

Muscarinic receptor-mediated excitation of rat intracardiac ganglion neurons.

PubMed

Hirayama, Michiko; Ogata, Masanori; Kawamata, Tomoyuki; Ishibashi, Hitoshi

2015-08-01

Modulation of the membrane excitability of rat parasympathetic intracardiac ganglion neurons by muscarinic receptors was studied using an amphotericin B-perforated patch-clamp recording configuration. Activation of muscarinic receptors by oxotremorine-M (OxoM) depolarized the membrane, accompanied by repetitive action potentials. OxoM evoked inward currents under voltage-clamp conditions at a holding potential of -60 mV. Removal of extracellular Ca(2+) markedly increased the OxoM-induced current (IOxoM). The inward IOxoM in the absence of extracellular Ca(2+) was fully inhibited by removal of extracellular Na(+), indicating the involvement of non-selective cation channels. The IOxoM was inhibited by organic cation channel antagonists including SKF-96365 and ML-204. The IOxoM was antagonized by muscarinic receptor antagonists with the following potency: 4-DAMP > pirenzepine = darifenacin > methoctramine. Muscarinic toxin 7 (MT-7), a highly selective inhibitor for M1 receptor, produced partial inhibition of the IOxoM. In the presence of MT-7, concentration-inhibition curve of the M3-preferring antagonist darifenacin was shifted to the left. These results suggest the contribution of M1 and M3 receptors to the OxoM response. The IOxoM was inhibited by U-73122, a phospholipase C inhibitor. The membrane-permeable IP3 receptor blocker xestospongin C also inhibited the IOxoM. Furthermore, pretreatment with thapsigargin and BAPTA-AM inhibited the IOxoM, while KN-62, a blocker of Ca(2+)/calmodulin-dependent protein kinase II, had no effect. These results suggest that the activation mechanism involves a PLC pathway, release of Ca(2+) from intracellular Ca(2+) stores and calmodulin. The cation channels activated by muscarinic receptors may play an important role in neuronal membrane depolarization in rat intracardiac ganglion neurons. Copyright © 2015 Elsevier Ltd. All rights reserved.

Soft tilt and rotational modes in the hybrid improper ferroelectric Ca3Mn2O7

NASA Astrophysics Data System (ADS)

Glamazda, A.; Wulferding, D.; Lemmens, P.; Gao, B.; Cheong, S.-W.; Choi, K.-Y.

2018-03-01

Raman spectroscopy is employed to probe directly the soft rotation and tilting modes, which are two primary order parameters predicted in the hybrid improper ferroelectric material Ca3Mn2O7 . We observe a giant softening of the 107 -cm-1 octahedron tilting mode by 26 cm-1 on heating through the structural transition from a ferroelectric to paraelectric orthorhombic phase. This is contrasted by a small softening of the 150 -cm-1 rotational mode by 6 cm-1. In the intermediate phase, the competing soft modes with different symmetries coexist, bringing about many-faceted anomalies in spin excitations and lattice vibrations. Our work demonstrates that the soft rotation and tilt patterns, relying on a phase-transition path, are a key factor in determining ferroelectric, magnetic, and lattice properties of Ca3Mn2O7 .

[Preoperative CT angiography for planning free perforator flaps in breast reconstruction].

PubMed

Kuekrek, H; Müller, D; Paepke, S; Dobritz, M; Machens, H-G; Giunta, R E

2011-04-01

Preoperative Doppler ultrasonography for planning free perforator flaps is widely established to identify preoperatively perforators. The method allows one to localise the penetrating point of the perforator through the abdominal fascia. By this means it is not possible to see the intramuscular course or the position of the perforator in relation to the inferior epigastric artery. Lately the technique of computed tomographic angiography provides an opportunity for visualising the course of perforator vessels in these tissues. This paper summarises our experience with the preoperative CT angiography in our breast centre. Since spring 2009 we have reconstructed the breasts of 44 female patients by using free flaps from the lower abdominal wall. 6 of these were bilateral. In a total number of 50 breast reconstructions we used 23 deep inferior epigastric perforator (DIEP) flaps and 27 muscle-sparing transverse rectus abdominis muscle (TRAM) flaps. In addition to the preoperative ultrasonography, a CT angiography of the lower abdomen was conducted in 29 patients. On average they showed at least 2 perforators on the left as well as right abdominal sides, which could be used as flap vessels based on their signal intensity. Based on their estimated microsurgical dissection complexity, the perforator vessels could be classified into 3 groups: 1) direct perforators of category A with short intramuscular course (39%), 2) perforators with long intramuscular course of category B (50%) and 3) "turn around" perforators of category C, which pass medially around the rectus abdominis (11%). The technique of CT angiography permits a reliable preoperative visualisation of perforators in their entire course and facilitates the selection of the supplying perforator as well as the intraoperative procedure for the surgeon. The suggested classification of perforators into 3 groups simplifies the preoperative assessment of the microsurgical dissection effort. Compared to the commonly used Doppler ultrasonography there are disadvantages like the additional cost factor and the radiation exposure. However, in our experience the more detailed planning increases the safety of flap raising and reduces surgery time, so that we consider CT angiography a positive tool to facilitate free perforator flaps. © Georg Thieme Verlag KG Stuttgart · New York.

Perforating Thin Metal Sheets

NASA Technical Reports Server (NTRS)

Davidson, M. E.

1985-01-01

Sheets only few mils thick bonded together, punched, then debonded. Three-step process yields perforated sheets of metal. (1): Individual sheets bonded together to form laminate. (2): laminate perforated in desired geometric pattern. (3): After baking, laminate separates into individual sheets. Developed for fabricating conductive layer on blankets that collect and remove ions; however, perforated foils have other applications - as conductive surfaces on insulating materials; stiffeners and conductors in plastic laminates; reflectors in antenna dishes; supports for thermal blankets; lightweight grille cover materials; and material for mockup of components.

Geopressured-geothermal test of the EDNA Delcambre No. 1 well, Vermilion Parish, Louisiana

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wieland, D.R.; Meriwether, J.

1977-11-16

Two sand intervals, Sand No. 3 and Sand No. 1, were independently tested during our program. Sand No. 3 was the deepeer zone and was tested first. A gamma ray--neutron log of these zones, and the intervals perforated, are shown. The gamma ray log run in 1968 showed Sand No. 1 to be a fairly uniform section with few shale breaks and our original plans were to perforate the entire interval. After obtaining the more recent GR log big shale breaks were shown to exist throughout the zone, so a smaller interval was selected. A net sand thickness of 48more » ft. was used for Sand No. 3 and 30 ft. for Sand No. 1. There was no data available to indicate whether these zones became thicker or thinner away from the wellbore; therefore, these values were used as net thickness in the reservoir calculations. The procedure used to perforate the two sands were different. Both were perforated with 0.33 inch jets at a density of 4 shots per foot; however, Sand No. 3 was perforated in two runs using a stand-off gun, whereas Sand No. 1 was perforated in one run using a centralized gun with the jet density being 4 shots per foot but oriented alternately at 180 degrees.« less

Perforation and bacterial contamination of microscope covers in lumbar spinal decompressive surgery.

PubMed

Osterhoff, Georg; Spirig, José; Klasen, Jürgen; Kuster, Stefan P; Zinkernagel, Annelies S; Sax, Hugo; Min, Kan

2014-01-01

To determine the integrity of microscope covers and bacterial contamination at the end of lumbar spinal decompressive surgery. A prospective study of 25 consecutive lumbar spinal decompressions with the use of a surgical microscope was performed. For detection of perforations, the microscope covers were filled with water at the end of surgery and the presence of water leakage in 3 zones (objective, ocular and control panel) was examined. For detection of bacterial contamination, swabs were taken from the covers at the same locations before and after surgery. Among the 25 covers, 1 (4%) perforation was observed and no association between perforation and bacterial contamination was seen; 3 (4%) of 75 smears from the 25 covers showed post-operative bacterial contamination, i.e. 2 in the ocular zone and 1 in the optical zone, without a cover perforation. The incidence of microscope cover perforation was very low and was not shown to be associated with bacterial contamination. External sources of bacterial contamination seem to outweigh the problem of contamination due to failure of cover integrity. © 2014 S. Karger AG, Basel.

Perforation and Bacterial Contamination of Microscope Covers in Lumbar Spinal Decompressive Surgery

PubMed Central

Osterhoff, Georg; Spirig, José; Klasen, Jürgen; Kuster, Stefan P.; Zinkernagel, Annelies S.; Sax, Hugo; Min, Kan

2014-01-01

Objective To determine the integrity of microscope covers and bacterial contamination at the end of lumbar spinal decompressive surgery. Materials and Methods A prospective study of 25 consecutive lumbar spinal decompressions with the use of a surgical microscope was performed. For detection of perforations, the microscope covers were filled with water at the end of surgery and the presence of water leakage in 3 zones (objective, ocular and control panel) was examined. For detection of bacterial contamination, swabs were taken from the covers at the same locations before and after surgery. Results Among the 25 covers, 1 (4%) perforation was observed and no association between perforation and bacterial contamination was seen; 3 (4%) of 75 smears from the 25 covers showed post-operative bacterial contamination, i.e. 2 in the ocular zone and 1 in the optical zone, without a cover perforation. Conclusions The incidence of microscope cover perforation was very low and was not shown to be associated with bacterial contamination. External sources of bacterial contamination seem to outweigh the problem of contamination due to failure of cover integrity. PMID:24903448

Management of nontraumatic corneal perforation with tectonic drape patch and cyanoacrylate glue.

PubMed

Khalifa, Yousuf M; Bailony, M Rami; Bloomer, Michele M; Killingsworth, Daniel; Jeng, Bennie H

2010-10-01

To report a case of nontraumatic corneal perforation managed with a tectonic drape patch. Interventional case report. A 60-year-old patient with a corneal scar in his left eye likely secondary to herpes simplex virus interstitial keratitis underwent laser peripheral iridotomy for narrow angles. He developed progressive thinning of the cornea overlying the scar that led to a descemetocele and then ultimately a 1.2- × 1.7-mm perforation. Intraoperatively, several attempts were made to seal the perforation with cyanoacrylate glue, but the wound continued to leak. Sterile plastic drape that was on the surgical field was fashioned into a 2-mm-diameter patch, and the peripheral edge of the tectonic drape patch was glued over the perforation, successfully sealing the cornea. One week later, the drape patch was intact without leak, and a penetrating keratoplasty was carried out without complication. Tectonic drape patch technique for nontraumatic corneal perforations in which there is tissue loss is a viable temporizing option when cyanoacrylate glue alone fails and when there is no corneal tissue or amniotic membrane available to close the wound.

Neonatal gastric perforation.

PubMed

Kuremu, R T; Hadley, G P; Wiersma, R

2004-01-01

Gastric perforation in neonates is a catastrophe associated with high morbidity. Most are due to underlying primary pathology. To review the management of gastric perforation in neonates in Kwa Zulu-Natal, South Africa. Retrospective study of consecutive complete data sets of neonates presenting with gastric perforation. Department of Paediatric Surgery, Nelson R. Mandela School of Medicine, University of Natal, Durban, South Africa. Eight neonates treated for gastric perforation between January 1998 and April 2003. Morbidity and mortality. There was an equal number of males and females. Median birth weight was 2.0 kg with a range of 1.4 to 3.2 kg. Five of the eight neonates were premature. Primary pathologies were associated with perforation in seven of the eight neonates. Prematurity, low birth weight and pneumonia were contributing factors to the poor outcome. Sepsis was a complication in seven of the eight neonates leading to their death (88% mortality). Active perinatal management, early treatment of primary pathologies, and protection of the stomach against distension in neonates at risk are essential in the management of neonatal gastric perforation.

Perforated peptic ulcer in Tikur Anbessa Hospital: a review of 74 cases.

PubMed

Ersumo, Tessema; W/Meskel, Yidnekachew; Kotisso, Berhanu

2005-01-01

Little is known on the pattern of perforated peptic ulcer in Ethiopia. To evaluate the early, outcome of management, a five-year retrospective analysis of 74 operated cases of perforated peptic ulcer was undertaken. Perforated peptic ulcer accounted for 3.4% of the adult emergency surgical procedures. The mean age was 32.6 years, with a male to female ratio of 7.2 to 1.0. Fifty-six percent of the cases were unmarried. In nearly 22.0% of the patients, no previous history of peptic ulcer disease was documented. Delay in diagnosis was noted in 95% of the cases. Most patients had duodenal ulcer perforation, and about 78% had purulent peritonitis at laparotomy. Fourteen died in hospital. Early presentation of patients to surgical care facilities may reduce morbidity and mortality in cases of peptic ulcer perforation.

[The risk of surgical glove perforations].

PubMed

Hagen, Gerd Ødegård; Arntzen, Halvard

2007-03-29

The increasing prevalence of blood-borne viral diseases has drawn attention to the barrier between the surgical personnel's hands and the patients body fluids during surgery. At present, the typical practice is to use double gloving in orthopaedic surgery, and single gloving in other types of surgery. The main purpose of our study was to estimate and compare the perforation risk in different categories of surgery. In a series of 655 surgical operations covering 5 main categories of surgery, all detected glove perforations were recorded and analysed. Perforations were found in 203 out of 655 operations (31%). The observed perforation frequency was 44.5% in gastrointestinal surgery, 34.7% in orthopaedic surgery, 31.1% in gynaecology, 18.6% in vascular surgery and 9.2% in general surgery. In some subcategories, the frequencies were even higher. In several categories of surgery, we found high perforation frequencies. Perforations in single gloves are often not detected during operations. This may increase the risk of transmission of blood-borne infections, particularly because the time of exposure may be long. Double indicator gloves make the intra-operative detection of perforations easier. Also double gloving is known to significantly reduce the perforation risk. The use of double indicator gloves is recommended in all categories of surgery.

Impact of Right-Sided Aneurysm, Rupture Status, and Size of Aneurysm on Perforator Infarction Following Microsurgical Clipping of Posterior Communicating Artery Aneurysms with a Distal Transsylvian Approach.

PubMed

Tanabe, Jun; Ishikawa, Tatsuya; Moroi, Junta; Sakata, Yoshinori; Hadeishi, Hiromu

2018-03-01

Posterior communicating artery (PCoA) aneurysms are among the most common aneurysms. Because blockage of the PCoA and perforators can cause adverse outcomes, occlusion of these arteries by surgical clipping should be avoided. The impact of factors on PCoA perforator infarction when using a distal transsylvian approach for PCoA aneurysms was examined. A total of 183 patients underwent PCoA aneurysm clipping, excluding application of fenestrated clips. Patients were divided into 2 groups: patients with PCoA perforator infarction (infarction group) and patients without infarction (noninfarction group). Multiple factors were analyzed in the 2 groups. Twenty-two of the 183 patients (12.0%) showed perforator infarction, mainly on magnetic resonance imaging evaluation, resulting in permanent deficits in 2 patients (1.1%). The proportion of right-sided operations (86.4% vs. 53.4%; P = 0.005) and surgery for rupture (90.9% vs. 55.9%; P = 0.002) were significantly higher in the infarction group than in the noninfarction group. Aneurysms were significantly larger in the infarction group (8.4 ± 3.8 mm) than in the noninfarction group (6.3 ± 3.0 mm; P = 0.02). Ruptured status (odds ratio [OR], 7.35; P = 0.01), right side (OR, 5.19; P = 0.01), and aneurysm size (OR, 1.18; P = 0.02) remained independent predictors of perforator infarction on multivariate logistic regression analysis. Ruptured status, right side, and large PCoA aneurysm were independent predictors of PCoA perforator infarction. Symptoms due to PCoA perforating infarction were mostly transient and rarely affected outcomes. Copyright © 2018 Elsevier Inc. All rights reserved.

Coronary Perforation Complicating Percutaneous Coronary Intervention in Patients With a History of Coronary Artery Bypass Surgery: An Analysis of 309 Perforation Cases From the British Cardiovascular Intervention Society Database.

PubMed

Kinnaird, Tim; Anderson, Richard; Ossei-Gerning, Nick; Cockburn, James; Sirker, Alex; Ludman, Peter; de Belder, Mark; Johnson, Thomas W; Copt, Samuel; Zaman, Azfar; Mamas, Mamas A

2017-09-01

The evidence base for coronary perforation (CP) occurring during percutaneous coronary intervention in patients with a history of coronary artery bypass surgery (PCI-CABG) is limited and the long-term effects unclear. Using a national PCI database, the incidence, predictors, and outcomes of CP during PCI-CABG were defined. Data were analyzed on all PCI-CABG procedures performed in England and Wales between 2005 and 2013. Multivariate logistic regressions and propensity scores were used to identify predictors of CP and its association with outcomes. During the study period, 309 CPs were recorded during 59 644 PCI-CABG procedures with the incidence rising from 0.32% in 2005 to 0.68% in 2013 ( P <0.001 for trend). Independent associates of perforation in native vessels included age, chronic occlusive disease intervention, rotational atherectomy use, number of stents, hypertension, and female sex. In graft PCI, predictors of perforation were history of stroke, New York Heart Association class, and number of stents used. In-hospital clinical complications including Q-wave myocardial infarction (2.9% versus 0.2%; P <0.001), major bleeding (14.0% versus 0.9%; P <0.001), blood transfusion (3.7% versus 0.2%; P <0.001), and death (10.0% versus 1.1%; P <0.001) were more frequent in patients with CP. A continued excess mortality occurred after perforation, with an odds ratio for 12-month mortality of 1.35 for perforation survivors compared with matched nonperforation survivors without a CP ( P <0.0001). CP is an infrequent event during PCI-CABG but is closely associated with adverse clinical outcomes. A legacy effect of perforation on 12-month mortality was observed. © 2017 American Heart Association, Inc.

Endovenous laser ablation of varicose perforating veins with the 1470-nm diode laser using the radial fibre slim.

PubMed

Zerweck, Christof; von Hodenberg, Eva; Knittel, Matthias; Zeller, Thomas; Schwarz, Thomas

2014-02-01

Endovenous Laser Ablation (EVLA) is one of the most accepted treatment options for varicose veins. The aim of this study was to investigate the efficacy and safety of the new radial fiber slim (ELVeS-radial-slim kit™) for the 1470 nm diode laser in perforator veins with a 1 month follow-up. Our prospective observational cohort study comprised 69 perforating veins in 55 patients. Ninety percent of all patients were in the CEAP-stage C3-C6. The radial fiber slim was used to occlude the perforating vein and the great or small saphenous vein in the same procedure. The primary efficacy endpoint of the study was ultrasonographically proven elimination of venous reflux in the perforating vein after at least one month. Secondary efficacy and further safety end points after one month were as follows: (1) sonographic exclusion of recanalization of the treated vein segments, (2) deep vein thrombosis (DVT), clinical pulmonary embolism (PE), or superficial vein thrombosis (SVT) as defined by objective testing, (3) death from any cause, (4) persistent clinical complaints such as pain and paresthesia. Follow-up could be completed in all patients. In all treated perforating varicose veins, occlusion with elimination of reflux could be demonstrated immediately after the procedure. After one month 95.6% of the treated veins were still occluded (67/69). During follow-up, we did not diagnose any DVT, PE or SVT in the area related to the treated perforating vein. No patient died. One patient reported paresthesia distally of the puncture site. Endovenous laser treatment of varicose perforating veins with 1470 nm diode laser using the radial fiber slim is effective and safe with low recanalization rates during 1-month follow-up.

Hyperpolarizing muscarinic responses of freshly dissociated rat hippocampal CA1 neurones.

PubMed Central

Wakamori, M; Hidaka, H; Akaike, N

1993-01-01

1. Intracellular mechanisms of the muscarinic acetylcholine (ACh) response were investigated in pyramidal neurones freshly dissociated from the rat hippocampal CA1 region. Current recordings were made in the whole-cell mode using the nystatin 'perforated'-patch technique, by which the muscarinic ACh response can be continuously recorded without so-called 'run-down' phenomenon. The amount of intracellular free Ca2+ ([Ca2+]i) was fluorometrically measured using fura-2. 2. In current clamp conditions, ACh induced a transient hyperpolarization accompanied by a decrease in membrane input resistance. 3. Under voltage clamp conditions at a holding potential (Vh) of -40 mV, ACh induced two types of muscarinic currents observed either alone or together: a transient outward current and a slowly activating sustained inward current. 4. The ACh-induced transient outward current reversed the direction at K+ equilibrium potential (EK), and the reversal potential (EACh) shifted 56.7 mV for a tenfold change of extracellular K+ concentration ([K+]o). 5. The ACh-induced transient outward current increased in a sigmoidal fashion with increase in ACh concentration, where the half-maximal concentration (EC50) and the Hill coefficient (n) were 8 x 10(-7) M and 1.9, respectively. Both muscarine and carbamylcholine mimicked the ACh response, but neither McN-A-343 (M1 agonist) nor oxotremorine (cardiac M2 agonist) induced any current. 6. Muscarinic antagonists reversibly blocked the ACh response in a concentration-dependent manner. The inhibitory potency was in the order of atropine > pirenzepine > AF-DX-116. 7. The ACh-induced transient outward current was never recorded when [Ca2+]i was chelated by the acetoxymethyl ester form of 1,2-bis(O-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid (BAPTA AM). On the other hand, in Ca(2+)-free external solution containing 2 mM EGTA and 10 mM Mg2+, the ACh response was elicited by the first application and successive ACh applications did not induce any response. Fura-2 imaging showed that [Ca2+]i was increased when ACh was added to the external medium with or without Ca2+, though in Ca(2+)-free medium only the first application of ACh increased the [Ca2+]i. 8. The ACh response was not affected by pretreatment with pertussis toxin (PTX) but the inhibitory effect of ACh on the high-threshold Ca2+ channel was abolished completely. 9. Pretreatment with Li+ enhanced the amplitude of the transient outward current and the increase in [Ca2+]i induced by ACh. 10. The calmodulin antagonists W-7, chlorpromazine and trifluoperazine reversibly inhibited the ACh response in a concentration-dependent manner.(ABSTRACT TRUNCATED AT 400 WORDS) PMID:7504109

Negative Inotropic Effects of High Mobility Box Group 1 Protein in Isolated Contracting Cardiac Myocytes

PubMed Central

Tzeng, Huei-Ping; Fan, Jinping; Vallejo, Jesus G.; Dong, Jian Wen; Chen, Xiongwen; Houser, Steven R.; Mann, Douglas L.

2013-01-01

HMGB1 released from necrotic cells or macrophages functions as a late inflammatory mediator, and has been shown to induce cardiovascular collapse during sepsis. Thus far, however, the effect(s) of HMGB1 in the heart are not known. We determined the effects of HMGB1 on isolated feline cardiac myocytes by measuring sarcomere shortening in contracting cardiac myocytes, intracellular Ca2+ transients using fluo-3, and L-type calcium currents using whole cell perforate configuration of the patch clamp technique. Treatment of isolated myocytes with HMGB1 (100 ng/ml) resulted in a 70% decrease in sarcomere shortening and a 50% decrease in the height of the peak Ca++ transient within 5 min (p <0.01). The immediate negative inotropic effects HMGB1 on cell contractility and calcium homeostasis were partially reversible upon washout of HMGB1. A significant inhibition of the inward L-type calcium currents also was documented by the patch clamp technique. HMGB1 induced the PKCε translocation and a PKC inhibitor significantly attenuated the negative inotropic effects of HMGB1. These studies show for the first time that HMGB1 impairs sarcomere shortening by decreasing calcium availability in cardiac myocytes through modulating membrane calcium influx, and suggest that HMGB1 maybe act as a novel myocardial depressant factor during cardiac injury. PMID:18223193

Endoscopic observation of different repair patterns in human traumatic tympanic membrane perforations.

PubMed

Huang, Peng; Zhang, Shujun; Gong, Xinhong; Wang, Xuesong; Lou, Zi-Han

2017-08-03

In the last decade, there has been an increasing use of biomaterial patches in the regeneration of traumatic tympanic membrane perforations. The major advantages of biomaterial patches are to provisionally restore the physiological function of the middle ear, thereby immediately improving ear symptoms, and act as a scaffold for epithelium migration. However, whether there are additional biological effects on eardrum regeneration is unclear for biological material patching in the clinic. This study evaluated the healing response for different repair patterns in human traumatic tympanic membrane perforations by endoscopic observation. In total, 114 patients with traumatic tympanic membrane perforations were allocated sequentially to two groups: the spontaneous healing group (n=57) and Gelfoam patch-treated group (n=57). The closure rate, closure time, and rate of otorrhea were compared between the groups at 3 months. Ultimately, 107 patients were analyzed in the two groups (52 patients in the spontaneous healing group vs. 55 patients in the Gelfoam patch-treated group). The overall closure rate at the end of the 3 month follow-up period was 90.4% in the spontaneous healing group and 94.5% in the Gelfoam patch-treated group; the difference was not statistically significant (p>0.05). However, the total average closure time was significantly different between the two groups (26.8±9.1 days in the spontaneous healing group vs. 14.7±9.1 days in the Gelfoam patch-treated group, p<0.01). In addition, the closure rate was not significantly different between the spontaneous healing group and Gelfoam patch-treated group regardless of the perforation size. The closure time in the Gelfoam patch-treated group was significantly shorter than that in the spontaneous healing group regardless of the perforation size (small perforations: 7.1±1.6 days vs. 12.6±3.9, medium-sized perforations: 13.3±2.2 days vs. 21.8±4.2 days, and large perforations: 21.2±4.7 days vs. 38.4±5.7 days; p<0.01). In the regeneration of traumatic tympanic membrane perforations, Gelfoam patching not only plays a scaffolding role for epithelial migration, it also promotes edema and hyperplasia of granulation tissue at the edges of the perforation and accelerates eardrum healing. Copyright © 2017 Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facial. Published by Elsevier Editora Ltda. All rights reserved.

Calcium isotope fractionation in a silicate dominated Cenozoic aquifer system

NASA Astrophysics Data System (ADS)

Li, Junxia; DePaolo, Donald J.; Wang, Yanxin; Xie, Xianjun

2018-04-01

To understand the characteristics of Ca isotope composition and fractionation in silicate-dominated Quaternary aquifer system, hydrochemical and isotope studies (87Sr/86Sr, 13CDIC and 44/40Ca) were conducted on groundwater, sediment and rock samples from the Datong basin, China. Along the groundwater flow path from the basin margin to the center, groundwater hydrochemical type evolves from Ca-HCO3 to Na-HCO3/Na-Cl type, which results from aluminosilicate hydrolysis, vertical mixing, cation exchange between CaX2 and NaX, and calcite/dolomite precipitation. These processes cause the decrease in groundwater Ca concentration and the associated modest fractionation of groundwater Ca isotopes along the flowpath. The groundwater δ44/40Ca value varies from -0.11 to 0.49‰. The elevated δ44/40Ca ratios in shallow groundwater are attributed to vertical mixing involving addition of irrigation water, which had the average δ44/40Ca ratio of 0.595‰. Chemical weathering of silicate minerals and carbonate generates depleted δ44/40Ca signatures in groundwater from Heng Mountain (east area) and Huanghua Uplift (west area), respectively. Along the groundwater flow path from Heng Mountain to central area of east area, cation exchange between CaX2 and NaX on clay mineral results in the enrichment of heavier Ca isotope in groundwater. All groundwater samples are oversaturated with respect to calcite and dolomite. The groundwater environment rich in organic matter promotes the precipitation of carbonate minerals via the biodegradation of organic carbon, thereby further promoting the elevation of groundwater δ44/40Ca ratios.

Action of aluminum, novel TPC1-type channel inhibitor, against salicylate-induced and cold-shock-induced calcium influx in tobacco BY-2 cells.

PubMed

Lin, Cun; Yu, Yawei; Kadono, Takashi; Iwata, Michiaki; Umemura, Kenji; Furuichi, Takuya; Kuse, Masaki; Isobe, Minoru; Yamamoto, Yoko; Matsumoto, Hideaki; Yoshizuka, Kazuharu; Kawano, Tomonori

2005-07-08

Previously, effect of Al ions on calcium signaling was assessed in tobacco cells expressing a Ca2+-monitoring luminescent protein, aequorin and a newly isolated putative plant Ca2+ channel protein from Arabidopsis thaliana, AtTPC1 (two-pore channel 1). TPC1 channels were shown to be the only channel known to be sensitive to Al and they are responsive to reactive oxygen species and cryptogein, a fungal elicitor protein. Thus, involvement of TPC1 channels in calcium signaling leading to development of plant defense mechanism has been suggested. Then, the use of Al as a specific inhibitor of TPC1-type plant calcium channels has been proposed. Here, using transgenic tobacco BY-2 cells expressing aequorin, we report on the evidence in support of the involvement of Al-sensitive signaling pathway requiring TPC1-type channel-dependent Ca2+ influx in response to salicylic acid, a key plant defense-inducing agent, but not to an elicitor prepared from the cell wall of rice blast disease fungus Magnaporthe grisea. In addition, involvement of Al-sensitive Ca2+ channels in response to cold shock was also tested. The data suggested that the elicitor used here induces the Ca2+ influx via Al-insensitive path, while salicylic acid and cold-shock-stimulate the influx of Ca2+ via Al-sensitive mechanism.

Addition of a 5/cm Spectral Resolution Band Model Option to LOWTRAN5.

DTIC Science & Technology

1980-10-01

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Incidence and patterns of surgical glove perforations: experience from Addis Ababa, Ethiopia.

PubMed

Bekele, Abebe; Makonnen, Nardos; Tesfaye, Lidya; Taye, Mulat

2017-03-20

Surgical glove perforation is a common event. The operating staff is not aware of the perforation until the procedure is complete, sometimes in as high as 70% of the incidences. Data from Ethiopia indicates that the surgical workforce suffers from a very surgery related accidents, however there is paucity of data regarding surgical glove perforation. The main objective is to describe the incidence and patterns of surgical glove perforation during surgical procedures and to compare the rates between emergency and elective surgeries at one of the main hospitals in Addis Ababa Ethiopia. This is a prospective study, performed at the Minilik II referral hospital, Addis Ababa. All surgical gloves worn during all major surgical procedures (Emergency and Elective) from June 1-July 20, 2016 were collected and used for the study. Standardised visual and hydro insufflation techniques were used to test the gloves for perforations. Parameters recorded included type of procedure performed, number of perforations, localisation of perforation and the roles of the surgical team. A total of 2634 gloves were tested, 1588 from elective and 1026 from emergency procedures. The total rate of perforation in emergency procedures was 41.4%, while perforation in elective surgeries was 30.0%. A statistically significant difference (P < 0.05) was found in between emergency and elective surgeries. There were a very high rate of perforations of gloves among first surgeons 40.6% and scrub nurses 38.8% during elective procedures and among first surgeons (60.14%), and second assistants (53.0%) during emergency surgeries. Only 0.4% of inner gloves were perforated. The left hand, the left index finger and thumb were the most commonly perforated parts of the glove. Glove perforation rate was low among consultant surgeons than residents. Our reported perforation rate is higher than most publications, and this shows that the surgical workforce in Ethiopia is under a clear and present threat. Measures such as double gloving seems to have effectively prevented cutaneous blood exposure and thus should become a routine for all surgical procedures. Manufacturing related defects and faults in glove quality may also be contributing factors.

Ambient Ozone Concentrations and the Risk of Perforated and Nonperforated Appendicitis: A Multicity Case-Crossover Study

PubMed Central

Tanyingoh, Divine; Dixon, Elijah; Johnson, Markey; Wheeler, Amanda J.; Myers, Robert P.; Bertazzon, Stefania; Saini, Vineet; Madsen, Karen; Ghosh, Subrata; Villeneuve, Paul J.

2013-01-01

Background: Environmental determinants of appendicitis are poorly understood. Past work suggests that air pollution may increase the risk of appendicitis. Objectives: We investigated whether ambient ground-level ozone (O3) concentrations were associated with appendicitis and whether these associations varied between perforated and nonperforated appendicitis. Methods: We based this time-stratified case-crossover study on 35,811 patients hospitalized with appendicitis from 2004 to 2008 in 12 Canadian cities. Data from a national network of fixed-site monitors were used to calculate daily maximum O3 concentrations for each city. Conditional logistic regression was used to estimate city-specific odds ratios (ORs) relative to an interquartile range (IQR) increase in O3 adjusted for temperature and relative humidity. A random-effects meta-analysis was used to derive a pooled risk estimate. Stratified analyses were used to estimate associations separately for perforated and nonperforated appendicitis. Results: Overall, a 16-ppb increase in the 7-day cumulative average daily maximum O3 concentration was associated with all appendicitis cases across the 12 cities (pooled OR = 1.07; 95% CI: 1.02, 1.13). The association was stronger among patients presenting with perforated appendicitis for the 7-day average (pooled OR = 1.22; 95% CI: 1.09, 1.36) when compared with the corresponding estimate for nonperforated appendicitis [7-day average (pooled OR = 1.02, 95% CI: 0.95, 1.09)]. Heterogeneity was not statistically significant across cities for either perforated or nonperforated appendicitis (p > 0.20). Conclusions: Higher levels of ambient O3 exposure may increase the risk of perforated appendicitis. PMID:23842601

Perforations and angulations of 324 cervical medial cortical pedicle screws: a possible guide to avoid lateral perforations with use of pedicle screws in lower cervical spine.

PubMed

Mahesh, Bijjawara; Upendra, Bidre; Vijay, Sekharappa; Arun, Kumar; Srinivasa, Reddy

2017-03-01

More than half of the perforations reported with usage of cervical pedicle screws (CPS) are lateral perforations, endangering the vertebral artery. The medial cortical pedicle screw (MCPS) technique with partial drilling of the medial cortex shifts the trajectory of pedicle screws medially, decreasing the lateral perforations. To evaluate the decrease in lateral perforations of CPS with use of MCPS technique, in relation to medial angulation. Retrospective analysis and technical report of the MCPS technique and its safety. A total of 58 patients operated on between December 2011 and May 2015 with insertion of pedicle screws from C3 to C7 were included in the study. Axial reconstructed computed tomography (CT) scan images of the inserted screws were evaluated for placement, perforations, and transverse plane angulations using the Surgimap software (Surgimap Spine 1.1.2.271 Intl. 2009 Nemaris LLC). The angulations of screws were analyzed by the type and level of placement through unpaired t test and analysis of variance test. A total of 58 patients operated on between December 2011 and May 2015 with insertion of pedicle screws from C3 to C7 were included in the study. There were 49 males and 9 females. Thirty-seven patients had cervical trauma, 17 had cervical spondylotic myelopathy, two had tumors, and two had ankylosing spondylitis. The average age was 49 years (range 18 to 80 years). The screws were inserted using the MCPS technique. All patients underwent postoperative CT scans with GE Optima CT540 16 slice CT scanner (GE Healthcare Chalfont St. Giles, Buckinghamshire, UK). Axial reconstructed images along the axis of the inserted screws were evaluated for placement and perforations. Further, all the screws were evaluated for transverse plane angulations using the Surgimap software. The angulations of screw were analyzed by the type and level of placement through unpaired t test and analysis of variance test. No funds were received by any of the authors for the purpose of the present study. A total of 324 screws were assessed with postoperative CT scans. Two hundred fifty-six were found to be placed within the pedicle and 68 (20.98%) screws were found to have perforations. Forty screws (12.34%) had grade I medial perforations, 14 screws (4.32%) had grade I lateral perforations, 10 screws (3.08%) had grade II medial perforations, and 4 screws (1.23%) had grade IIlateral perforations. The average angulation of the nonperforated screws (n=256) was 28.6° (43°-17°), that of laterally perforated screws was 20.33° (13°-24°), and that of the medially perforated screws was 34.94° (45°-20°). On statistical analysis with each series, the 99% CI range for the in-screw angles was 27.91° to 29.34°; for the laterally perforated screw series, it was 18.42° to 22.23°; and that for the medially perforated screw series was 32.97° to 36.9°. The MCPS technique represents a shift in the concept of placement of CPS from the cancellous core to the medial cortex, avoiding screw deflection laterally by the thick proximal medial cortex. The present study shows that the lateral perforations can be consistently avoided, with a medial angulation of more than 27.91°, which is the primary concern with the use of pedicle screws in lower cervical spine. Further, the MCPS technique reduces the lateral perforations at a lesser insertion angle, which is technically desirable. Copyright © 2016 Elsevier Inc. All rights reserved.

Eradication of Helicobacter pylori for prevention of ulcer recurrence after simple closure of perforated peptic ulcer: a meta-analysis of randomized controlled trials.

PubMed

Wong, Chung-Shun; Chia, Chee-Fah; Lee, Hung-Chia; Wei, Po-Li; Ma, Hon-Ping; Tsai, Shin-Han; Wu, Chih-Hsiung; Tam, Ka-Wai

2013-06-15

Eradication of Helicobacter pylori has become part of the standard therapy for peptic ulcer. However, the role of H pylori eradication in perforation of peptic ulcers remains controversial. It is unclear whether eradication of the bacterium confers prolonged ulcer remission after simple repair of perforated peptic ulcer. A systematic review and meta-analysis of randomized controlled trials was performed to evaluate the effects of H pylori eradication on prevention of ulcer recurrence after simple closure of perforated peptic ulcers. The primary outcome to evaluate these effects was the incidence of postoperative ulcers; the secondary outcome was the rate of H pylori elimination. The meta-analysis included five randomized controlled trials and 401 patients. A high prevalence of H pylori infection occurred in patients with perforated peptic ulcers. Eradication of H pylori significantly reduced the incidence of ulcer recurrence at 8 wk (risk ratio 2.97; 95% confidence interval: 1.06-8.29) and 1 y (risk ratio 1.49; 95% confidence interval: 1.10-2.03) postoperation. The rate of H pylori eradication was significantly higher in the treatment group than in the nontreatment group. Eradication therapy should be provided to patients with H pylori infection after simple closure of perforated gastroduodenal ulcers. Copyright © 2013 Elsevier Inc. All rights reserved.

The Allure of Quick Victory. Lessons from Peru’s Fight Against Sendero Luminoso

DTIC Science & Technology

2010-10-01

example of successful government consolidation following an internal conflict. 1. “Si no hacemos algo tendremos unas FARC,” El Comercio (19 April 2009...and Shining Path in Peru,” Shining Path of Peru, 3-4. 18. “Suman 15 los Soldados Asesinados,” El Comercio , 22 April 2009. 19. “Por lo menos 50...terroristas atacaron sede policial del poblado de San Jose de Secce,” El Comercio , 2 August 2009. 20. “Helicóptero Caído Cumplía Misión de Rescate de Heridos

Voltage-gated calcium channels of Paramecium cilia

PubMed Central

Lodh, Sukanya; Valentine, Megan S.; Van Houten, Judith L.

2016-01-01

ABSTRACT Paramecium cells swim by beating their cilia, and make turns by transiently reversing their power stroke. Reversal is caused by Ca2+ entering the cilium through voltage-gated Ca2+ (CaV) channels that are found exclusively in the cilia. As ciliary Ca2+ levels return to normal, the cell pivots and swims forward in a new direction. Thus, the activation of the CaV channels causes cells to make a turn in their swimming paths. For 45 years, the physiological characteristics of the Paramecium ciliary CaV channels have been known, but the proteins were not identified until recently, when the P. tetraurelia ciliary membrane proteome was determined. Three CaVα1 subunits that were identified among the proteins were cloned and confirmed to be expressed in the cilia. We demonstrate using RNA interference that these channels function as the ciliary CaV channels that are responsible for the reversal of ciliary beating. Furthermore, we show that Pawn (pw) mutants of Paramecium that cannot swim backward for lack of CaV channel activity do not express any of the three CaV1 channels in their ciliary membrane, until they are rescued from the mutant phenotype by expression of the wild-type PW gene. These results reinforce the correlation of the three CaV channels with backward swimming through ciliary reversal. The PwB protein, found in endoplasmic reticulum fractions, co-immunoprecipitates with the CaV1c channel and perhaps functions in trafficking. The PwA protein does not appear to have an interaction with the channel proteins but affects their appearance in the cilia. PMID:27707864

The Puzzlingly Large Ca II Triplet Absorption in Dwarf Elliptical Galaxies

NASA Astrophysics Data System (ADS)

Michielsen, D.; De Rijcke, S.; Dejonghe, H.; Zeilinger, W. W.; Hau, G. K. T.

2003-11-01

We present central CaT, PaT, and CaT* indices for a sample of 15 dwarf elliptical galaxies (dE's). Twelve of these have CaT*~7 Å and extend the negative correlation between the CaT* index and the central velocity dispersion σ, which was derived for bright elliptical galaxies (E's), down to 20 km s-1 < σ < 55 km s-1. For five dE's, we have independent age and metallicity estimates. Four of these have CaT*~7 Å, much higher than expected from their low metallicities (-1.5<[Z/H]<-0.5). The observed anticorrelation of CaT* as a function of σ or Z is in flagrant disagreement with theory. We discuss some of the amendments that have been proposed to bring the theoretical predictions into agreement with the observed CaT* values of bright E's and how they can be extended to incorporate the observed CaT* values of dE's as well. Moreover, three dE's in our sample have CaT*~5 Å, as would be expected for metal-poor stellar systems. Any theory for dE evolution will have to be able to explain the coexistence of low-CaT* and high-CaT* dE's at a given mean metallicity. This could be the first direct evidence that the dE population is not homogeneous and that different evolutionary paths led to morphologically and kinematically similar but chemically distinct objects. Based on observations collected at the European Southern Observatory, Paranal, Chile (ESO Large Program 165.N 0115).

Novel role for the transient potential receptor melastatin 4 channel in guinea pig detrusor smooth muscle physiology

PubMed Central

Smith, Amy C.; Hristov, Kiril L.; Cheng, Qiuping; Xin, Wenkuan; Parajuli, Shankar P.; Earley, Scott; Malysz, John

2013-01-01

Members of the transient receptor potential (TRP) channel superfamily, including the Ca2+-activated monovalent cation-selective TRP melastatin 4 (TRPM4) channel, have been recently identified in the urinary bladder. However, their expression and function at the level of detrusor smooth muscle (DSM) remain largely unexplored. In this study, for the first time we investigated the role of TRPM4 channels in guinea pig DSM excitation-contraction coupling using a multidisciplinary approach encompassing protein detection, electrophysiology, live-cell Ca2+ imaging, DSM contractility, and 9-phenanthrol, a recently characterized selective inhibitor of the TRPM4 channel. Western blot and immunocytochemistry experiments demonstrated the expression of the TRPM4 channel in whole DSM tissue and freshly isolated DSM cells with specific localization on the plasma membrane. Perforated whole cell patch-clamp recordings and real-time Ca2+ imaging experiments with fura 2-AM, both using freshly isolated DSM cells, revealed that 9-phenanthrol (30 μM) significantly reduced the cation current and decreased intracellular Ca2+ levels. 9-Phenanthrol (0.1–30 μM) significantly inhibited spontaneous, 0.1 μM carbachol-induced, 20 mM KCl-induced, and nerve-evoked contractions in guinea pig DSM-isolated strips with IC50 values of 1–7 μM and 70–80% maximum inhibition. 9-Phenanthrol also reduced nerve-evoked contraction amplitude induced by continuous repetitive electrical field stimulation of 10-Hz frequency and shifted the frequency-response curve (0.5–50 Hz) relative to the control. Collectively, our data demonstrate the novel finding that TRPM4 channels are expressed in guinea pig DSM and reveal their critical role in the regulation of guinea pig DSM excitation-contraction coupling. PMID:23302778

Accuracy analysis of pedicle screw placement in posterior scoliosis surgery: comparison between conventional fluoroscopic and computer-assisted technique.

PubMed

Kotani, Yoshihisa; Abumi, Kuniyoshi; Ito, Manabu; Takahata, Masahiko; Sudo, Hideki; Ohshima, Shigeki; Minami, Akio

2007-06-15

The accuracy of pedicle screw placement was evaluated in posterior scoliosis surgeries with or without the use of computer-assisted surgical techniques. In this retrospective cohort study, the pedicle screw placement accuracy in posterior scoliosis surgery was compared between conventional fluoroscopic and computer-assisted surgical techniques. There has been no study systemically analyzing the perforation pattern and comparative accuracy of pedicle screw placement in posterior scoliosis surgery. The 45 patients who received posterior correction surgeries were divided into 2 groups: Group C, manual control (25 patients); and Group N, navigation surgery (20 patients). The average Cobb angles were 73.7 degrees and 73.1 degrees before surgery in Group C and Group N, respectively. Using CT images, vertebral rotation, pedicle axes as measured to anteroposterior sacral axis and vertebral axis, and insertion angle error were measured. In perforation cases, the angular tendency, insertion point, and length abnormality were evaluated. The perforation was observed in 11% of Group C and 1.8% in Group N. In Group C, medial perforations of left screws were demonstrated in 8 of 9 perforated screws and 55% were distributed either in L1 or T12. The perforation consistently occurred in pedicles in which those axes approached anteroposterior sacral axis within 5 degrees . The average insertion errors were 8.4 degrees and 5.0 degrees in Group C and Group N, respectively, which were significantly different (P < 0.02). The medial perforation in Group C occurred around L1, especially when pedicle axis approached anteroposterior sacral axis. This consistent tendency was considered as the limitation of fluoroscopic screw insertion in which horizontal vertebral image was not visible. The use of surgical navigation system successfully reduced the perforation rate and insertion angle errors, demonstrating the clear advantage in safe and accurate pedicle screw placement of scoliosis surgery.

Complications of endoscopic dilation for esophageal stenosis after endoscopic submucosal dissection of superficial esophageal cancer.

PubMed

Kishida, Yoshihiro; Kakushima, Naomi; Kawata, Noboru; Tanaka, Masaki; Takizawa, Kohei; Imai, Kenichiro; Hotta, Kinichi; Matsubayashi, Hiroyuki; Ono, Hiroyuki

2015-10-01

Endoscopic dilation (ED) is used for the treatment of benign strictures caused by reflux esophagitis or anastomotic stenosis after esophagectomy. Esophageal stenosis is a major complication after endoscopic submucosal dissection (ESD) of large superficial esophageal cancer, but little is known regarding the incidence of complications of ED for stenosis caused by esophageal ESD. This was a retrospective study conducted at a single institution. From September 2002 to December 2012, a total of 1,337 ED procedures were performed for stenosis after esophageal ESD in 121 patients. The incidence of complications of ED and related clinical characteristics were analyzed. The incidence of bleeding was 0.8 % (1/121) per patient and 0.07 % (1/1,337) per procedure. The incidence of perforation was 4.1 % (5/121) per patient and 0.37 % (5/1,337) per procedure. Perforation occurred at a median of third time of ED procedures (range 2-9 procedures) and at a median of 18 days (range 8-29 days) after ESD. There were no significant characteristics correlated to perforation, such as location, circumferential extent, or diameter of mucosal defect after ESD. The total number of ED procedures was significantly larger among perforation cases (37, range 6-57) compared with those without perforation (7, range 1-70) (p = 0.01), and the treatment duration tended to be longer (190 vs. 69 days, respectively). The incidence of bleeding caused by ED for esophageal stenosis after ESD was very low. Relevant risk of perforation should be considered for patients requiring multiple ED procedures.

Lace plant ethylene receptors, AmERS1a and AmERS1c, regulate ethylene-induced programmed cell death during leaf morphogenesis.

PubMed

Rantong, Gaolathe; Evans, Rodger; Gunawardena, Arunika H L A N

2015-10-01

The lace plant, Aponogeton madagascariensis, is an aquatic monocot that forms perforations in its leaves as part of normal leaf development. Perforation formation occurs through developmentally regulated programmed cell death (PCD). The molecular basis of PCD regulation in the lace plant is unknown, however ethylene has been shown to play a significant role. In this study, we examined the role of ethylene receptors during perforation formation. We isolated three lace plant ethylene receptors AmERS1a, AmERS1b and AmERS1c. Using quantitative PCR, we examined their transcript levels at seven stages of leaf development. Through laser-capture microscopy, transcript levels were also determined in cells undergoing PCD and cells not undergoing PCD (NPCD cells). AmERS1a transcript levels were significantly lower in window stage leaves (in which perforation formation and PCD are occurring) as compared to all other leaf developmental stages. AmERS1a and AmERS1c (the most abundant among the three receptors) had the highest transcript levels in mature stage leaves, where PCD is not occurring. Their transcript levels decreased significantly during senescence-associated PCD. AmERS1c had significantly higher transcript levels in NPCD compared to PCD cells. Despite being significantly low in window stage leaves, AmERS1a transcripts were not differentially expressed between PCD and NPCD cells. The results suggested that ethylene receptors negatively regulate ethylene-controlled PCD in the lace plant. A combination of ethylene and receptor levels determines cell fate during perforation formation and leaf senescence. A new model for ethylene emission and receptor expression during lace plant perforation formation and senescence is proposed.

Prospective study of glove perforation in obstetrical and gynecological operations: are we safe enough?

PubMed

Malhotra, Monika; Sharma, Jai Bhagwan; Wadhwa, Leena; Arora, Raksha

2004-08-01

To assess the glove perforation rate, efficacy of double gloving, effect of duration of surgery, expertise of surgeon and operative urgency on the glove perforation rate in obstetrical and gynecologic operations. From February to September 2002, double glove protocol was made necessary for all major obstetrical and gynecologic procedures. The operating surgeon, first and second assistant were included in the study. Gloves damage was noted (overt by inspection, occult by hydroinsufflation technique). Of the 156 procedures included in study, 32 procedures were performed (all emergency operations) single-gloved because surgeons found double gloving clumsy (56%), made it difficult to tie knots due to lack of dexterity (24%), or were too tight (20%). One thousand one hundred and twenty single gloves were examined after each procedure by hydroinsufflation. The overall perforation rate was 13.6% (single versus double outer gloves, 13.8% versus l3.2%, P > 0.05). Matching perforations were found in six cases (4.6%). Thus, the protection offered by double gloves was 95.4% even if the outer gloves were perforated. Four inner gloves had preexisting perforations. Sixty unused gloves checked similarly revealed a perforation rate of 1.6%. Emergency cases had higher perforation rate compared to elective surgeries (16.6% versus 10.8%, P < 0.00 1). Surgeries lasting for more than 40 min had a higher perforation rate compared to those finished in less than or equal to 40 min (18.6% versus 7.6%, P < 0.001). The middle finger of the left hand was the most commonly involved. The surgeon, first assistant and second assistant were involved in 73.6, 23.3 and 3.2% cases, respectively. Double gloving offers considerable protection against exposure to contaminants in the blood and body fluids of the patient and should be made routine, especially in developing countries where HIV, hepatitis B and C are widely prevalent. Double gloving should be made mandatory in emergency procedures, which have a higher perforation rate due to operative urgency, and gloves should be changed in operations lasting for more than 40 min to ensure integrity of barrier.

Use of open-path FTIR and inverse dispersion technique to quantify gaseous nitrogen loss from an intensive vegetable production site

NASA Astrophysics Data System (ADS)

Bai, Mei; Suter, Helen; Lam, Shu Kee; Sun, Jianlei; Chen, Deli

2014-09-01

An open-path Fourier transform infrared (OP-FTIR) spectroscopic technique in combination with a backward Lagrangian stochastic (bLS) dispersion model (WindTrax) can be used to simultaneously measure gaseous emissions of N2O, NH3, CH4 and CO2. We assessed the capability of this technique for measuring NH3 and N2O emissions following the application of calcium nitrate (Ca(NO3)2), Nitrophoska (NPK) and chicken manure on a celery farm at Boneo, Victoria, during April and May 2013. We found that the OP-FTIR/WindTrax method was able to measure the diurnal variation in NH3 flux from the field site following application of chicken manure with measured emissions ranging from approximately 0.1-9.8 kg NH3-N ha-1 day-1. The OP-FTIR/WindTrax method also detected a diurnal variation in N2O flux of 1.5-6.2 kg N2O-N ha-1 day-1 and N2O flux increased in response to application of the Ca(NO3)2. We concluded that the OP-FTIR/WindTrax technique can quantify gaseous N loss from vegetable production systems.

GABA(B) receptor modulation of feedforward inhibition through hippocampal neurogliaform cells.

PubMed

Price, Christopher J; Scott, Ricardo; Rusakov, Dmitri A; Capogna, Marco

2008-07-02

Feedforward inhibition of neurons is a fundamental component of information flow control in the brain. We studied the roles played by neurogliaform cells (NGFCs) of stratum lacunosum moleculare of the hippocampus in providing feedforward inhibition to CA1 pyramidal cells. We recorded from synaptically coupled pairs of anatomically identified NGFCs and CA1 pyramidal cells and found that, strikingly, a single presynaptic action potential evoked a biphasic unitary IPSC (uIPSC), consisting of two distinct components mediated by GABA(A) and GABA(B) receptors. A GABA(B) receptor-mediated unitary response has not previously been observed in hippocampal excitatory neurons. The decay of the GABA(A) receptor-mediated response was slow (time constant = 50 ms), and was tightly regulated by presynaptic GABA(B) receptors. Surprisingly, the GABA(B) receptor ligands baclofen and (2S)-3-{[(1S)-1-(3,4-dichlorophenyl)ethyl]amino-2-hydroxypropyl}(phenylmethyl)phosphinic acid (CGP55845), while affecting the NGFC-mediated uIPSCs, had no effect on action potential-evoked presynaptic Ca2+ signals monitored in individual axonal boutons of NGFCs with two-photon microscopy. In contrast, baclofen clearly depressed presynaptic Ca2+ transients in non-NGF interneurons. Changes in extracellular Ca2+ concentration that mimicked the effects of baclofen or CGP55845 on uIPSCs significantly altered presynaptic Ca2+ transients. Electrophysiological data suggest that GABA(B) receptors expressed by NGFCs contribute to the dynamic control of the excitatory input to CA1 pyramidal neurons from the temporoammonic path. The NGFC-CA1 pyramidal cell connection therefore provides a unique and subtle mechanism to shape the integration time domain for signals arriving via a major excitatory input to CA1 pyramidal cells.

Raman spectroscopy and x-ray diffraction of sp 3 CaC O 3 at lower mantle pressures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lobanov, Sergey S.; Dong, Xiao; Martirosyan, Naira S.

The exceptional ability of carbon to form sp 2 and sp 3 bonding states leads to a great structural and chemical diversity of carbon-bearing phases at nonambient conditions. Here we use laser-heated diamond-anvil cells combined with synchrotron x-ray diffraction, Raman spectroscopy, and first-principles calculations to explore phase transitions in CaC O 3 at P > 40 GPa . We find that postaragonite CaC O 3 transforms to the previously predicted P 2 1 / c CaC O 3 with sp 3 -hybridized carbon at 105 GPa ( ~ 30 GPa higher than the theoretically predicted crossovermore » pressure). The lowest-enthalpy transition path to P2 1 / c CaC O 3 includes reoccurring sp 2 and sp 3 CaC O 3 intermediate phases and transition states, as revealed by our variable-cell nudged-elastic-band simulation. Raman spectra of P 2 1 / c CaC O 3 show an intense band at 1025 c m -1 , which we assign to the symmetric C-O stretching vibration based on empirical and first-principles calculations. This Raman band has a frequency that is ~ 20 % low-ymmetric C-O stretching in sp 2 CaC O 3 due to the C-O bond length increase across the sp 2 ~ sp 3 transition and can be used as a fingerprint of tetrahedrally coordinated carbon in other carbonates.« less

Definitive or conservative surgery for perforated gastric ulcer?--An unresolved problem.

PubMed

Sarath Chandra, Sistla; Kumar, S Siva

2009-04-01

Gastric ulcer perforation has not been the focus of many studies. In addition there is a need to analyze the results of gastric perforation separately and not along with duodenal perforations, to identify the factors influencing the outcome and to develop strategies for its management. Retrospective analysis of 54 patients presenting with gastric perforation. Mean age of the patients was 44.5 years with male preponderance. Morbidity following Closure of the perforation, acid reduction surgery and resection was not significantly different. Overall mortality was 16.6% with highest mortality 24.1% following simple closure. Mortality following simple closure and definitive surgery was not significantly different. Univariate analysis revealed preoperative shock, associated medical illness and surgical delay to be significant factors for mortality whereas on multivariate analysis, preoperative shock was the only independent predictor of mortality. Mortality increased with increasing Boey score but the association between the type of surgery and probability of survival was not statistically significant. Boey risk score is useful in predicting the outcome of surgical treatment for gastric perforation. Definitive surgery is not associated with greater morbidity or mortality compared to simple closure.

Factors related to persisting perforations after ventilation tube insertion.

PubMed

O'Connell Ferster, Ashley P; Tanner, April Michelle; Karikari, Kodjo; Roberts, Christopher; Wiltz, Derek; Carr, Michele M

2016-02-01

Over a million ventilation tubes are placed annually in the United States, making this one of the most commonly performed procedures in the field of medicine. Certain factors increase the risk of persistent tympanic membrane perforation following the extrusion of short term ventilation tubes. Persistent perforations may fail to heal on their own, necessitating surgical closure to avoid conductive hearing loss. It is important to detect factors that may predict children who are at increased risk for persistent perforations. This study was a retrospective chart review that involved 757 patients between 2003 and 2008. The patients studied were within the age of 2 months-17 years, and all had short term tubes placed. The chart data also included demographic information, comorbidities, and information related to tube insertion and follow-up care. Chi-square, t-test, and multivariate logistic regression were conducted to compare variables between patients with perforations and those without. Data from 757 patients was analyzed, showing that perforation rate is associated with rhinorrhea, operative tube removal, aural polyps, and otorrhea (OR 1.72, 8.16, 4.69, and 1.72 respectively). The absence of otorrhea decreased the likelihood of TM perforations and no significant differences were found in gender, total number of sets of tubes, type of tube, use of nasal steroids, adenoidectomy, or nasal congestion. Our findings suggest that children with rhinorrhea, otorrhea, aural polyps, or prolonged intubation requiring operative tube removal should be identified clinically as children at risk of persisting perforation. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

High power laser perforating tools and systems

DOEpatents

Zediker, Mark S; Rinzler, Charles C; Faircloth, Brian O; Koblick, Yeshaya; Moxley, Joel F

2014-04-22

ystems devices and methods for the transmission of 1 kW or more of laser energy deep into the earth and for the suppression of associated nonlinear phenomena. Systems, devices and methods for the laser perforation of a borehole in the earth. These systems can deliver high power laser energy down a deep borehole, while maintaining the high power to perforate such boreholes.

Use of a platelet-rich fibrin membrane to repair traumatic tympanic membrane perforations: a comparative study.

PubMed

Gür, Özer Erdem; Ensari, Nuray; Öztürk, Mehmet Türker; Boztepe, Osman Fatih; Gün, Taylan; Selçuk, Ömer Tarık; Renda, Levent

2016-10-01

(1) To evaluate the effects of a platelet-rich fibrin (PRF) membrane in the repair of traumatic tympanic membrane (TM) perforations; and (2) to compare the use of a PRF membrane with the paper patch technique with regard to recovery rates, healing time, and correction of the mean air-bone gap. A randomized, prospective analysis was performed for 60 patients who were treated for traumatic TM perforations using one of the two methods. Closure rate, speed of healing, and hearing gain were compared between the PRF (Group 1) and paper patch (Group 2) groups. Closure was obtained in 28 (93%) perforations in Group 1 and 25 (83%) perforations in Group 2 (p > 0.05). On day 10, full closure of the TM was observed in 24 (80%) patients in Group 1 and 16 (53%) patients in Group 2 (p < 0.05). The improvement in the mean air-bone gap was 14.1 dB in Group 1 and 12.4 dB in Group 2 on post-operative day 45 (p < 0.05). In comparison with the paper patch method, PRF, a new method, provided more rapid healing with more successful audiological results, and with no requirement for a second procedure.

Perforated peptic ulcer disease in Zewditu Hospital.

PubMed

Asefa, Zelalem; G/eyesus, Awetash

2012-04-01

Peptic ulcer perforation is a serious complication of peptic ulcer disease with a significant morbidity and mortality. To evaluate 76 patients operated for peptic ulcer perforation and analyse the associated factors in Zewditu Memorial Hospital, Addis Ababa from September 2006 to August 2008. A retrospective analysis of medical records of 76 patients who were operated up on for perforated peptic ulcer over a two year period (2006-2008). The male to female ratio was 6.6:1 with a mean age being 31.5 years. The most common presenting symptom was abdominal pain in 76 (100%) patients. History of smoking and khat chewing was documented in 53/64 (82.8%) and 48/64 (75%) of the patients respectively. Twenty five per cent of the patients gave no history of previous peptic ulcer disease. Seventy patients (92.1%) presented after 48 hours of their illness. The mean hospital stay was 14.5 days. Leucocytosis was found in 31.6% of the cases. Sixty five (85.5%) patients had duodenal ulcer perforation. Postoperative complications occurred in 24 (31.6%) patients. Twelve (15.8%) patients died in the hospital. Early presentation of patients and change in life style may reduce morbidity and mortality in patients with peptic ulcer perforation.

A generalized muon trajectory estimation algorithm with energy loss for application to muon tomography

NASA Astrophysics Data System (ADS)

Chatzidakis, Stylianos; Liu, Zhengzhi; Hayward, Jason P.; Scaglione, John M.

2018-03-01

This work presents a generalized muon trajectory estimation algorithm to estimate the path of a muon in either uniform or nonuniform media. The use of cosmic ray muons in nuclear nonproliferation and safeguard verification applications has recently gained attention due to the non-intrusive and passive nature of the inspection, penetrating capabilities, as well as recent advances in detectors that measure position and direction of the individual muons before and after traversing the imaged object. However, muon image reconstruction techniques are limited in resolution due to low muon flux and the effects of multiple Coulomb scattering (MCS). Current reconstruction algorithms, e.g., point of closest approach (PoCA) or straight-line path (SLP), rely on overly simple assumptions for muon path estimation through the imaged object. For robust muon tomography, efficient and flexible physics-based algorithms are needed to model the MCS process and accurately estimate the most probable trajectory of a muon as it traverses an object. In the present work, the use of a Bayesian framework and a Gaussian approximation of MCS is explored for estimation of the most likely path of a cosmic ray muon traversing uniform or nonuniform media and undergoing MCS. The algorithm's precision is compared to Monte Carlo simulated muon trajectories. It was found that the algorithm is expected to be able to predict muon tracks to less than 1.5 mm root mean square (RMS) for 0.5 GeV muons and 0.25 mm RMS for 3 GeV muons, a 50% improvement compared to SLP and 15% improvement when compared to PoCA. Further, a 30% increase in useful muon flux was observed relative to PoCA. Muon track prediction improved for higher muon energies or smaller penetration depth where energy loss is not significant. The effect of energy loss due to ionization is investigated, and a linear energy loss relation that is easy to use is proposed.

A generalized muon trajectory estimation algorithm with energy loss for application to muon tomography

DOE PAGES

Chatzidakis, Stylianos; Liu, Zhengzhi; Hayward, Jason P.; ...

2018-03-28

Here, this work presents a generalized muon trajectory estimation (GMTE) algorithm to estimate the path of a muon in either uniform or nonuniform media. The use of cosmic ray muons in nuclear nonproliferation and safeguards verification applications has recently gained attention due to the non-intrusive and passive nature of the inspection, penetrating capabilities, as well as recent advances in detectors that measure position and direction of the individual muons before and after traversing the imaged object. However, muon image reconstruction techniques are limited in resolution due to low muon flux and the effects of multiple Coulomb scattering (MCS). Current reconstructionmore » algorithms, e.g., point of closest approach (PoCA) or straight-line path (SLP), rely on overly simple assumptions for muon path estimation through the imaged object. For robust muon tomography, efficient and flexible physics-based algorithms are needed to model the MCS process and accurately estimate the most probable trajectory of a muon as it traverses an object. In the present work, the use of a Bayesian framework and a Gaussian approximation of MCS are explored for estimation of the most likely path of a cosmic ray muon traversing uniform or nonuniform media and undergoing MCS. The algorithm’s precision is compared to Monte Carlo simulated muon trajectories. It was found that the algorithm is expected to be able to predict muon tracks to less than 1.5 mm RMS for 0.5 GeV muons and 0.25 mm RMS for 3 GeV muons, a 50% improvement compared to SLP and 15% improvement when compared to PoCA. Further, a 30% increase in useful muon flux was observed relative to PoCA. Muon track prediction improved for higher muon energies or smaller penetration depth where energy loss is not significant. Finally, the effect of energy loss due to ionization is investigated, and a linear energy loss relation that is easy to use is proposed.« less

A generalized muon trajectory estimation algorithm with energy loss for application to muon tomography

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chatzidakis, Stylianos; Liu, Zhengzhi; Hayward, Jason P.

Here, this work presents a generalized muon trajectory estimation (GMTE) algorithm to estimate the path of a muon in either uniform or nonuniform media. The use of cosmic ray muons in nuclear nonproliferation and safeguards verification applications has recently gained attention due to the non-intrusive and passive nature of the inspection, penetrating capabilities, as well as recent advances in detectors that measure position and direction of the individual muons before and after traversing the imaged object. However, muon image reconstruction techniques are limited in resolution due to low muon flux and the effects of multiple Coulomb scattering (MCS). Current reconstructionmore » algorithms, e.g., point of closest approach (PoCA) or straight-line path (SLP), rely on overly simple assumptions for muon path estimation through the imaged object. For robust muon tomography, efficient and flexible physics-based algorithms are needed to model the MCS process and accurately estimate the most probable trajectory of a muon as it traverses an object. In the present work, the use of a Bayesian framework and a Gaussian approximation of MCS are explored for estimation of the most likely path of a cosmic ray muon traversing uniform or nonuniform media and undergoing MCS. The algorithm’s precision is compared to Monte Carlo simulated muon trajectories. It was found that the algorithm is expected to be able to predict muon tracks to less than 1.5 mm RMS for 0.5 GeV muons and 0.25 mm RMS for 3 GeV muons, a 50% improvement compared to SLP and 15% improvement when compared to PoCA. Further, a 30% increase in useful muon flux was observed relative to PoCA. Muon track prediction improved for higher muon energies or smaller penetration depth where energy loss is not significant. Finally, the effect of energy loss due to ionization is investigated, and a linear energy loss relation that is easy to use is proposed.« less

Hippocampal CA1 local field potential oscillations induced by olfactory cue of liked food.

PubMed

Samerphob, Nifareeda; Cheaha, Dania; Chatpun, Surapong; Kumarnsit, Ekkasit

2017-07-01

Eating motivation is induced not only by negative energy balance but also food related cues. However, neural processing for acquisition of learned food preference remains to be established. This study aimed to identify hippocampal neural signaling in response to olfactory cue (chocolate scent) after completion of repetitive chocolate sessions. Male Swiss albino mice implanted with intracranial electrode into the hippocampus were used for local field potential (LFP) recording. Animals were given chocolate sessions (a piece of 2g chocolate per each mouse to eat on day 1, 3, 5 and 7). Hippocampal CA1 LFP signals and exploratory behavior of animals receiving chocolate scent were analyzed before and after chocolate sessions. The experiment was performed in a place preference-like apparatus with the zones of normal food pellet and chocolate (both kept in a small perforated cup for smell dispersion) at the opposite ends. Following chocolate sessions, time spent in a chocolate zone and CA1 LFP patterns were analyzed in comparison to control levels. Two-way ANOVA revealed significant increase in time spent seeking for chocolate. Frequency analysis of LFP power spectra revealed significant increases in delta and theta powers. Phase-amplitude analysis showed significant increase in maximal modulation index and decrease in frequency for phase of theta-high gamma coupling. Taken together, neural signaling in the hippocampus was sensitive to chocolate olfactory cue that might underlie learning process in response to repeated chocolate consumptions that primed intense food approaching behavior. Ultimately, these LFP patterns might reflect motivation to eat and predict feeding probability. Copyright © 2017 Elsevier Inc. All rights reserved.

Oblique along path toward structures at rear of parcel. Original ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Oblique along path toward structures at rear of parcel. Original skinny mosaic path along edge of structures was altered (delineation can be seen in concrete) path was widened with a newer mosaic to make access to the site safer. Structures (from right) edge of Round House (with "Spring Garden"), Pencil house, Shell House, School House, wood lattice is attached to chain-link fence along north (rear) property line. These structures were all damaged by the 1994 Northridge earthquake. Camera facing northeast. - Grandma Prisbrey's Bottle Village, 4595 Cochran Street, Simi Valley, Ventura County, CA

Anatomical study of the popliteal artery perforator-based propeller flap and its clinical application.

PubMed

Onishi, Tadanobu; Shimizu, Takamasa; Omokawa, Shohei; Sananpanich, Kanit; Kido, Akira; Mahakkanukrauh, Pasuk; Tanaka, Yasuhito

2018-05-30

There is lack of anatomical information regarding cutaneous perforator of the popliteal artery and its connections with the descending branch of the inferior gluteal and profunda femoris arteries. We aimed to evaluate the anatomical basis of popliteal artery perforator-based propeller flap from the posterior thigh region and to demonstrate our experience utilizing this flap. Ten fresh cadaveric lower extremities were dissected following injection of a silicone compound into the femoral artery. We investigated the number, location, length, and diameter of cutaneous perforators of the popliteal artery. Based on the results, we treated three cases with a large soft tissue defect around the knee using popliteal artery perforator-based propeller flap. We found a mean of 1.9 cutaneous perforators arising from the popliteal artery with a mean pedicle length of 6 cm and a mean arterial internal diameter of 0.9 mm, which were located at an average of 4 cm proximal to the bicondylar line. The most distal perforator consistently arose along the small saphenous vein and connected proximally with concomitant artery of the posterior femoral cutaneous nerve, forming a connection with perforating arteries of the profunda femoris artery. A mean of 4.5 cutaneous perforators branched from the arterial connection sites. All clinical cases healed without any complications. The popliteal artery perforator-based propeller flap is reliable for reconstruction of soft tissue defects around the knee. The flap should include the deep fascia and concomitant artery along with the posterior femoral cutaneous nerve for maintaining the blood supply.

Parasacral Perforator Flaps for Reconstruction of Sacral Pressure Sores.

PubMed

Lin, Chin-Ta; Chen, Shih-Yi; Chen, Shyi-Gen; Tzeng, Yuan-Sheng; Chang, Shun-Cheng

2015-07-01

Despite advances in reconstruction techniques, pressure sores continue to present a challenge to the plastic surgeon. The parasacral perforator flap is a reliable flap that preserves the entire contralateral side as a future donor site. On the ipsilateral side, the gluteal muscle itself is preserved and all flaps based on the inferior gluteal artery are still possible. We present our experience of using parasacral perforator flaps in reconstructing sacral defects. Between August 2004 and January 2013, 19 patients with sacral defects were included in this study. All the patients had undergone surgical reconstruction of sacral defects with a parasacral perforator flap. The patients' sex, age, cause of sacral defect, flap size, flap type, numbers of perforators used, rotation angle, postoperative complications, and hospital stay were recorded. There were 19 parasacral perforator flaps in this series. All flaps survived uneventfully except for 1 parasacral perforator flap, which failed because of methicillin-resistant Staphylococcus aureus infection. The overall flap survival rate was 95% (18/19). The mean follow-up period was 17.3 months (range, 2-24 months). The average length of hospital stay was 20.7 days (range, 9-48 days). No flap surgery-related mortality was found. Also, there was no recurrence of sacral pressure sores or infected pilonidal cysts during the follow-up period. Perforator-based flaps have become popular in modern reconstructive surgery because of low donor-site morbidity and good preservation of muscle. Parasacral perforator flaps are durable and reliable in reconstructing sacral defects. We recommend the parasacral perforator flap as a good choice for reconstructing sacral defects.

Substrate-dependent changes in mitochondrial function, intracellular free calcium concentration and membrane channels in pancreatic beta-cells.

PubMed

Duchen, M R; Smith, P A; Ashcroft, F M

1993-08-15

Microfluorimetric and patch-clamp techniques have been combined to determine the relationship between changes in mitochondrial metabolism, the activity of KATP channels and changes in intracellular free calcium concentration ([Ca2+]i) in isolated pancreatic beta-cells in response to glucose, ketoisocaproic acid (KIC) and the electron donor couple tetramethyl p-phenylenediamine (TMPD) and ascorbate. Exposure of cells to 20 mM glucose raised NAD(P)H autofluorescence after a delay of 28 +/- 1 s (mean +/- S.E.M., n = 30). The mitochondrial inner membrane potential, delta psi m (monitored using rhodamine 123 fluorescence), hyperpolarized with a latency of 49 +/- 6 s (n = 17), and the [Ca2+]i rose after 129 +/- 13 s (n = 5). The amplitudes of the metabolic changes were graded appropriately with glucose concentration over the range 2.5-20 mM. All variables responded to KIC with shorter latencies: NAD(P)H autofluorescence rose after a delay of 20 +/- 3 s (n = 5) and rhodamine 123 changed after 21 +/- 3 s (n = 6). The electron donor couple, TMPD with ascorbate, rapidly hyperpolarized delta psi m and raised [Ca2+]i. When [Ca2+]i was raised by sustained exposure to 20 mM glucose, TMPD had no further effect. TMPD also decreased whole-cell KATP currents and depolarized the cell membrane, measured with the perforated patch configuration. These data are consistent with a central role for mitochondrial oxidative phosphorylation in coupling changes in glucose concentration with the secretion of insulin.

Repairing Fetal Membranes with a Self-adhesive Ultrathin Polymeric Film: Evaluation in Mid-gestational Rabbit Model.

PubMed

Pensabene, Virginia; Patel, Premal P; Williams, Phillip; Cooper, Trisha L; Kirkbride, Kellye C; Giorgio, Todd D; Tulipan, Noel B

2015-08-01

Preterm premature rupture of membranes causes 40% of all preterm births, affecting 150000 women each year in the United States. Prenatal diagnostic procedures and surgical interventions increase incidence of adverse events, leading to iatrogenic membrane rupture after a fetoscopic procedure in 45% of cases. We propose an ultrathin, self-adherent, poly-L-lactic acid patch ("nanofilm") as a reparative wound closure after endoscopic/fetoscopic procedures. These nanofilms are compatible with application in wet conditions and with minimally invasive instrumentation. Ex vivo studies to evaluate the nanofilm were conducted using human chorion-amnion (CA) membranes. A custom-built inflation device was used for mechanical characterization of CA membranes and for assessment of nanofilm adhesion and sealing of membrane defects up to 3 mm in size. These ex vivo tests demonstrated the ability of the nanofilm to seal human CA defects ranging in size from 1 to 3 mm in diameter. In vivo survival studies were conducted in 25 mid-gestational rabbits, defects were created by perforating the uterus and the CA membranes and subsequently using the nanofilm to seal these wounds. These in vivo studies confirmed the successful sealing of defects smaller than 3 mm observed ex vivo. Histological analysis of whole harvested uteri 7 days after surgery showed intact uterine walls in 59% of the nanofilm repaired fetuses, along with increased uterine size and intrauterine development in 63% of the cases. In summary, we have developed an ultrathin, self-adhesive nanofilm for repair of uterine membrane defects.

Clinical applications of perforator-based propeller flaps in upper limb soft tissue reconstruction.

PubMed

Ono, Shimpei; Sebastin, Sandeep J; Yazaki, Naoya; Hyakusoku, Hiko; Chung, Kevin C

2011-05-01

A propeller flap is an island flap that moves from one orientation to another by rotating around its vascular axis. The vascular axis is stationary, and flap movement is achieved by revolving on this axis. Early propeller flaps relied on a thick, subcutaneous pedicle to maintain vascularity, and this limited the flap rotation to 90°. With increasing awareness of the location and the vascular territory perfused by cutaneous perforators, it is now possible to design propeller flaps based on a single perforator, so-called "perforator-based propeller flaps." These flaps permit flap rotation up to 180°. We present the results of upper limb soft tissue reconstruction using perforator-based propeller flaps. We constructed a treatment strategy based on the location of the soft tissue defect and the perforator anatomy for expedient wound coverage in 1 stage. All perforator-based propeller flaps derived from 3 institutions that were used for upper limb soft tissue reconstruction were retrospectively analyzed. The parameters studied included the size and location of the defect, the perforator that was used, the size and shape of the flap, the direction (ie, clockwise or counter-clockwise) of flap rotation, the degree of twisting of the perforator, the management of the donor site (ie, linear closure or skin grafting), and flap survival (recorded as the percentage of the flap area that survived). Twelve perforator-based propeller flaps were used to reconstruct upper limb soft tissue defects in 12 patients. Six different perforators were used as vascular pedicles. The donor defects of 11 flaps could be closed primarily. One flap was partially lost in a patient with electrical burns. Perforator-based propeller flaps provide a reliable option for covering small- to medium-size upper limb soft tissue defects. Copyright © 2011 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

Influence of operating microscope in the sealing of cervical perforations.

PubMed

Schmidt, Bruna Schwingel; Zaccara, Ivana Maria; Reis Só, Marcus Vinícius; Kuga, Milton Carlos; Palma-Dibb, Regina Guenka; Kopper, Patrícia Maria Poli

2016-01-01

Accidental root canal perforations are among the main complications of endodontic treatment. This study evaluated the influence of operating microscope (OM) in the marginal adaptation of mineral trioxide aggregate (MTA) (Angelus(®)) and glass ionomer (Vitremer) inserted into cervical perforations. Perforations were made in the cervical third of the buccal wall of the root canal in mandibular incisors. Next, the teeth were divided into four groups (N = 10): MG - MTA without OM; VG - Vitremer without OM; MOMG - MTA with OM; VOMG - Vitremer with OM. The perforations were sealed according to the group and the teeth were prepared for analysis by confocal laser scanning microscope. Images of perforation region (1,024×) were made and the gap presented by the materials was measured using the Image J program. LEXT OLS4100 three dimensional (3D) measuring laser microscope measured the volumetric misfit. Data of gap were analyzed by Kruskal-Wallis and Dunn's tests. Analysis of variance (ANOVA) and Tukey's tests compared the volumetric misfits. The results showed lower volume and gap in the interface dentin/material in VOMG compared to the other groups (P < 0.05). The use of OM improved the quality of cervical perforations sealed with Vitremer, being indicated in clinical situations of iatrogenic cervical perforations.

Effects of perforation number of blade on aerodynamic performance of dual-rotor small axial flow fans

NASA Astrophysics Data System (ADS)

Hu, Yongjun; Wang, Yanping; Li, Guoqi; Jin, Yingzi; Setoguchi, Toshiaki; Kim, Heuy Dong

2015-04-01

Compared with single rotor small axial flow fans, dual-rotor small axial flow fans is better regarding the static characteristics. But the aerodynamic noise of dual-rotor small axial flow fans is worse than that of single rotor small axial flow fans. In order to improve aerodynamic noise of dual-rotor small axial flow fans, the pre-stage blades with different perforation numbers are designed in this research. The RANS equations and the standard k-ɛ turbulence model as well as the FW-H noise model are used to simulate the flow field within the fan. Then, the aerodynamic performance of the fans with different perforation number is compared and analyzed. The results show that: (1) Compared to the prototype fan, the noise of fans with perforation blades is reduced. Additionally, the noise of the fans decreases with the increase of the number of perforations. (2) The vorticity value in the trailing edge of the pre-stage blades of perforated fans is reduced. It is found that the vorticity value in the trailing edge of the pre-stage blades decreases with the increase of the number of perforations. (3) Compared to the prototype fan, the total pressure rising and efficiency of the fans with perforation blades drop slightly.

Electro-Optic Propagation

DTIC Science & Technology

2002-09-30

Electro - Optic Propagation Stephen Doss-Hammel SPAWARSYSCEN San Diego code 2858 49170 Propagation Path San Diego, CA 92152-7385 phone: (619...OBJECTIVES The electro - optical propagation objectives are: 1) The acquisition and analysis of mid-wave and long-wave infrared transmission and...elements to the electro - optical propagation model development. The first element is the design and execution of field experiments to generate useful

76 FR 42161 - Notice of Final Federal Agency Actions on Proposed Highway in California

Federal Register 2010, 2011, 2012, 2013, 2014

2011-07-18

... Gilman Drive; installation of new ramp meters; and, construction of a bicycle path along I-5. The project... at http://www.dot.ca.gov/dist11/envir.htm . Pending Federal actions include: 1. Section 401 Water Quality Certification from the San Diego Regional Water Quality Control Board (RWQCB), under Section 401...

Growth conditions, elemental accumulation and induced physiological changes in Chinese cabbage.

PubMed

Moreno, Diego A; Víllora, Gemma; Ruiz, Juan M; Romero, Luis

2003-08-01

Soils contaminated with low levels of heavy metals and other trace elements are now frequently used for vegetable growing. In this situation, heavy metals and trace elements from these polluted soils may accumulate in the agricultural plants being grown in them and thereby enter the human food chain. The objectives of this study are to elucidate the effects of growth conditions, manipulated by the crop covers, on the phytoaccumulation of elements, and to investigate the conceivable influences of these conditions on the plant biochemistry. In three consecutive years of field experiments, open air (T(0)), and floating rowcover treatments (T(1): perforated polyethylene 50 micrometers; T(2): polypropylene 17 gm(-2)) were used to produce different environmental conditions for the growth of Chinese cabbage [Brassica rapa L. (Pekinensis group) cv. 'Nagaoka 50']. Five samplings (whole tops) were carried out from transplanting to harvest and measurements of B, Al, Ag, Si and Ca concentration as well as phenolics (orto-diphenols, total phenols and anthocyanins), pectic fractions, amino acids (histidine, phenylalanine and tyrosine) and polyphenol oxidase activity, were carried out in samples. The T(1) (perforated polyethylene sheet) gave greater B, Al, Ag and Si concentration and phytoextraction (in weight units) than the open-air control. These findings can help to develop new cost-effective techniques for phytoremediation as the application of plastic covers in the field. The build-up of heavy metals in those crops would make the product less suitable for human consumption.

Deliverable 2.4.4 -- Evaluation and single-well models for the demonstration wells, Class 1

DOE Office of Scientific and Technical Information (OSTI.GOV)

Deo, Milind; Morgan Craig D.

2000-07-12

Two single-well models were developed for Michelle Ute and Malnar Pike wells. The perforated intervals span thousands of feet in both the wells. Geological properties were calculated for all the perforated beds. The information was used to develop models for these two wells. These were comprehensive models since they took into account all the perforated beds.

Kinetic, pharmacological and activity-dependent separation of two Ca2+ signalling pathways mediated by type 1 metabotropic glutamate receptors in rat Purkinje neurones

PubMed Central

Canepari, Marco; Ogden, David

2006-01-01

Type 1 metabotropic glutamate receptors (mGluR1) in Purkinje neurones (PNs) are important for motor learning and coordination. Here, two divergent mGluR1 Ca2+-signalling pathways and the associated membrane conductances were distinguished kinetically and pharmacologically after activation by 1-ms photorelease of l-glutamate or by bursts of parallel fibre (PF) stimulation. A new, mGluR1-mediated transient K+ conductance was seen prior to the slow EPSC (sEPSC). It was seen only in PNs previously allowed to fire spontaneously or held at depolarized potentials for several seconds and was slowly inhibited by agatoxin IVA, which blocks P/Q-type Ca2+ channels. It peaked in 148 ms, had well-defined kinetics and, unlike the sEPSC, was abolished by the phospholipase C (PLC) inhibitor U73122. It was blocked by the BK Ca2+-activated K+ channel blocker iberiotoxin and unaffected by apamin, indicating selective activation of BK channels by PLC-dependent store-released Ca2+. The K+ conductance and underlying transient Ca2+ release showed a highly reproducible delay of 99.5 ms following PF burst stimulation, with a precision of 1–2 ms in repeated responses of the same PN, and a subsequent fast rise and fall of Ca2+ concentration. Analysis of Ca2+ signals showed that activation of the K+ conductance by Ca2+ release occured in small dendrites and subresolution structures, most probably spines. The results show that PF burst stimulation activates two pathways of mGluR1 signalling in PNs. First, transient, PLC-dependent Ca2+ release from stores with precisely reproducible timing and second, slower Ca2+ influx in the cation-permeable sEPSC channel. The priming by prior Ca2+ influx in P/Q-type Ca2+ channels may determine the path of mGluR1 signalling. The precise timing of PLC-mediated store release may be important for interactions of PF mGluR1 signalling with other inputs to the PN. PMID:16497716

Voltage-gated calcium channels of Paramecium cilia.

PubMed

Lodh, Sukanya; Yano, Junji; Valentine, Megan S; Van Houten, Judith L

2016-10-01

Paramecium cells swim by beating their cilia, and make turns by transiently reversing their power stroke. Reversal is caused by Ca 2+ entering the cilium through voltage-gated Ca 2+ (Ca V ) channels that are found exclusively in the cilia. As ciliary Ca 2+ levels return to normal, the cell pivots and swims forward in a new direction. Thus, the activation of the Ca V channels causes cells to make a turn in their swimming paths. For 45 years, the physiological characteristics of the Paramecium ciliary Ca V channels have been known, but the proteins were not identified until recently, when the P. tetraurelia ciliary membrane proteome was determined. Three Ca V α1 subunits that were identified among the proteins were cloned and confirmed to be expressed in the cilia. We demonstrate using RNA interference that these channels function as the ciliary Ca V channels that are responsible for the reversal of ciliary beating. Furthermore, we show that Pawn (pw) mutants of Paramecium that cannot swim backward for lack of Ca V channel activity do not express any of the three Ca V 1 channels in their ciliary membrane, until they are rescued from the mutant phenotype by expression of the wild-type PW gene. These results reinforce the correlation of the three Ca V channels with backward swimming through ciliary reversal. The PwB protein, found in endoplasmic reticulum fractions, co-immunoprecipitates with the Ca V 1c channel and perhaps functions in trafficking. The PwA protein does not appear to have an interaction with the channel proteins but affects their appearance in the cilia. © 2016. Published by The Company of Biologists Ltd.

A systematic review of the management and outcome of ERCP related duodenal perforations using a standardized classification system.

PubMed

Cirocchi, Roberto; Kelly, Michael Denis; Griffiths, Ewen A; Tabola, Renata; Sartelli, Massimo; Carlini, Luigi; Ghersi, Stefania; Di Saverio, Salomone

2017-12-01

The incidence of duodenal perforation after ERCP ranges from 0.09% to 1.67% and mortality up to 8%. This systematic review was registered in Prospective Register of Systematic Reviews, PROSPERO. Stapfer classification of ERCP-related duodenal perforations was used. The systematic search yielded 259 articles. Most frequent post-ERCP perforation was Stapfer type II (58.4%), type I second most frequent perforation (17.8%) followed by Stapfer type III in 13.2% and type IV in 10.6%. Rate of NOM was lowest in Stapfer type I perforations (13%), moderate in type III lesions (58.1%) and high in other types of perforations (84.2% in type II and 84.6% in IV). In patients underwent early surgical treatment (<24 h from ERCP) the most frequent operation was simple duodenal suture with or without omentopexy (93.7%). In patients undergoing late surgical treatment (>24 h from ERCP) interventions performed were more complex. In type I lesions post-operative mortality rate was higher in patients underwent late operation (>24 h). In type I lesions, failure of NOM occurred in 42.8% of patients. In type II failure of NOM occurred in 28.9% of patients and in type III there was failure of NOM in only 11.1%, none in type IV. Postoperative mortality after NOM failure was 75% in type I, 22.5% in type II and none died after surgical treatment for failure of NOM in type III perforations. This systematic review showed that in patients with Stapfer type I lesions, early surgical treatment gives better results, however the opposite seems true in Stapfer III and IV lesions. Copyright © 2017 Royal College of Surgeons of Edinburgh (Scottish charity number SC005317) and Royal College of Surgeons in Ireland. Published by Elsevier Ltd. All rights reserved.

Omental patch repair effectively treats perforated marginal ulcer following Roux-en-Y gastric bypass.

PubMed

Wendling, Mark R; Linn, John G; Keplinger, Kara M; Mikami, Dean J; Perry, Kyle A; Melvin, W Scott; Needleman, Bradley J

2013-02-01

Marginal ulcer formation remains a significant complication of Roux-en-Y gastric bypass (RYGB). Up to 1 % of all RYGB patients will develop free perforation of a marginal ulcer. Classically, this complication has required anastomotic revision; however, this approach is associated with significant morbidity. Several small series have suggested that omental patch repair may be effective. The aim of this study was to examine the management of perforated marginal ulcers following RYGB. All patients who underwent operative intervention for perforated ulcers between 2003 and 2011 were reviewed. Those with a history of RYGB with perforation of a marginal ulcer were included in the analysis. Data collected included operative approach, operative time, blood loss, length of hospital stay, complications, smoking history, and steroid or NSAID use. From January 2003 to December 2011, a total of 1,760 patients underwent RYGB at our institution. Eighteen (0.85 %) developed perforation of a marginal ulcer. Three patients' original procedure was performed at another institution. Eight patients (44 %) had at least one risk factor for ulcer formation. Treatment included omental patch repair (laparoscopic, n = 7; open, n = 9) or anastomotic revision (n = 2). Compared to anastomotic revision, omental patch repair had shorter OR time (101 ± 57 vs. 138 ± 2 min), decreased estimated blood loss (70 ± 72 vs. 250 ± 71 mL), and shorter total length of stay (5.6 ± 1.4 vs. 11.0 ± 5.7 days). Perforated marginal ulcer represents a significant complication of RYGB. Patients should be educated to reduce risk factors for perforation, as prolonged proton pump inhibitor therapy may not prevent this complication in a patient with even just one risk factor. In our sample population we found laparoscopic or open omental patch repair to be a safe and effective treatment for this condition and it was associated with decreased operative time, blood loss, and length of stay.

Preoperative factors influencing mortality and morbidity in peptic ulcer perforation.

PubMed

Sivaram, P; Sreekumar, A

2018-04-01

Perforated peptic ulcer is one of the most common surgical emergencies worldwide. With the improvement in medical therapy for peptic ulcers, the number of elective surgical procedures has come down. However, the incidence of perforated peptic ulcer is still increasing and remains as a substantial health problem with significant postoperative morbidity and mortality. This study aimed to find out the association between various preoperative and intraoperative factors with the postoperative mortality and morbidity in patients operated for peptic ulcer perforation. This prospective observational study had a time based sample of 101 perforation peritonitis cases admitted to the surgical wards of a tertiary care center from February 2015 to January 2016 who underwent laparotomy, diagnosed to have peptic ulcer perforation and underwent simple closure with an omental patch. Data regarding age, gender, presenting complaints, time elapsed from the onset of symptoms to surgery, physical examination findings, comorbid diseases, laboratory and imaging findings, intraoperative findings, length of hospital stay, postoperative morbidity, and mortality were recorded and analyzed. Female gender, older age group, perforation surgery interval more than 36 h, and size of perforation more than 1 cm 2 were found to be significant factors influencing postoperative mortality and morbidity. Postoperative morbidity was also associated with comorbid diseases. Abnormal renal function on presentation was identified as an additional risk factor for postoperative morbidity and longer hospital stay. An understanding of these factors, identification of patients at risk and early intervention can help in reducing the postoperative morbidity and mortality in peptic ulcer perforation.

Comparison of Thermal Performances between Low Porosity Perforate Plate and Flat Plate Solar Air Collector

NASA Astrophysics Data System (ADS)

Chan, Hoy-Yen; Vinson, A. A.; Baljit, S. S. S.; Ruslan, M. H.

2018-04-01

Flat plate solar air collector is the most common collector design, which is relatively simpler to fabricate and lower cost. In the present study, perforated plate solar collector was developed to improve the system thermal performance. A glazed perforated plate of 6mm holes diameter with square geometry was designed and installed as the absorber of the collector. The influences of solar radiation intensity and mass flow rate on the thermal performance were investigated. The perforated collector was compared with the flat plate solar collector under the same operating conditions. The highest values of thermal efficiency in this study for the perforated plate (PP) and the flat plate (FP) solar collectors were 59% and 36% respectively, at solar radiation intensity of 846 Wm-2 and mass flow rate of 0.02 kgs-1. Furthermore, PP collector gave better thermal performance compared to FP collector; and compared to previous studies, the present perforated design was compatible with the flat plate with double pass designs.

Utility of Immature Granulocyte Percentage in Pediatric Appendicitis

PubMed Central

Mathews, Eleanor K.; Griffin, Russell L.; Mortellaro, Vincent; Beierle, Elizabeth A.; Harmon, Carroll M.; Chen, Mike K.; Russell, Robert T.

2014-01-01

Background Acute appendicitis is the most common cause of abdominal surgery in children. Adjuncts are utilized to help clinicians predict acute or perforated appendicitis, which may affect treatment decisions. Automated hematologic analyzers can perform more accurate automated differentials including immature granulocyte percentages (IG%). Elevated IG% has demonstrated improved accuracy for predicting sepsis in the neonatal population than traditional immature to total neutrophil count (I/T) ratios. We intended to assess the additional discriminatory ability of IG% to traditionally assessed parameters in the differentiation between acute and perforated appendicitis. Materials and Methods We identified all patients with appendicitis from July 2012 to June 2013 by ICD-9 code. Charts were reviewed for relevant demographic, clinical, and outcome data, which were compared between acute and perforated appendicitis groups using Fischer’s exact and t-test for categorical and continuous variables, respectively. We utilized an adjusted logistic regression model utilizing clinical lab values to predict the odds of perforated appendicitis. Results 251 patients were included in the analysis. Those with perforated appendicitis had a higher white blood cell (WBC) count (p=0.0063), C-reactive protein (CRP) (p<0.0001), and IG% (p=0.0299). In the adjusted model, only elevated CRP (OR 3.46, 95% CI 1.40-8.54) and presence of left shift (OR 2.66, 95% CI 1.09-6.46) were significant predictors of perforated appendicitis. The c-statistic of the final model was 0.70, suggesting fair discriminatory ability in predicting perforated appendicitis. Conclusions IG% did not provide any additional benefit to elevated CRP and presence of left shift in the differentiation between acute and perforated appendicitis. PMID:24793450

Characteristics of Perforated Diffusers at Free-stream Mach Number 1.90

NASA Technical Reports Server (NTRS)

Hunczak, Henry R; Kremzier, Emil J

1950-01-01

An investigation was conducted at Mach number 1.90 to determine pressure recovery and mass-flow characteristics of series of perforated convergent-divergent supersonic diffusers. Pressure recoveries as high as 96 percent were obtained, but at reduced mass flows through the diffuser. Theoretical considerations of effect of perforation distribution on shock stability in converging section of diffuser are presented and correlated with experimental data. A method of estimating relative importance of pressure recovery and mass flow on internal thrust coefficient basis is given and a comparison of various diffusers investigated is made.

Endothelial reaction to perforating and non-perforating excimer laser excisions in rabbits

DOE Office of Scientific and Technical Information (OSTI.GOV)

Koch, J.W.; Lang, G.K.; Naumann, G.O.

1991-05-01

With an ArF excimer laser (193 nm, 750 mJ/cm2, 20 Hz) and a special slit-mask system, perforating and non-perforating linear keratectomies were performed in 55 rabbit corneas with a follow-up from 1 hour to 6 months. Varying the pulse number according to ablation rate (0.8 micron/pulse) and corneal thickness, four linear radial excisions (3 mm length, 70 microns width) of increasing depth (70%, 80%, 90%, 100% perforation) were produced. The corneas were processed for light microscopy, scanning and transmission electron microscopy, and vital staining of the endothelium. Except for mild cell contact alterations and discrete single cell damage in themore » 90% deep excisions, no endothelial damage could be detected after non-perforating keratectomies. Minute (less than 20 microns) and small (20 to 100 microns maximal diameter) perforations induced cell enlargement, formation of pseudopodia, rosette-like figures, multi-nucleated giant cells, and ultimately uniform reformation of the cell pattern (1 hour to 7 days postoperatively). Larger excimer laser defects of Descemet's membrane (greater than 100 microns) were overgrown by dedifferentiated endothelial cells producing a new PAS-positive basement membrane. Vital staining revealed the complete and stable reorganization of the endothelium over these lesions within 6 months. The authors observations are similar to those reported on the endothelial repair process following other surgical manipulations (knife incisions, direct Nd:YAG-laser trauma) and support the applicability of excimer lasers for corneal trephination in patients.« less

Management of Pediatric Perforated Appendicitis: Comparing Outcomes Using Early Appendectomy Versus Solely Medical Management.

PubMed

Bonadio, William; Rebillot, Katie; Ukwuoma, Onyinyechi; Saracino, Christine; Iskhakov, Arthur

2017-10-01

There is controversy regarding whether children with perforated appendicitis should receive early appendectomy (EA) versus medical management (MM) with antibiotics and delayed interval appendectomy. The objective of this study was to compare outcomes of children with perforated appendicitis who receive EA versus MM. Case review of consecutive children <18 years of age with perforated appendicitis who received either EA or MM during an 8-year period. Criteria for hospital discharge included patient being afebrile for at least 24 hours, pain-free and able to tolerate oral intake. Of 203 patients diagnosed with perforated appendicitis, 122 received EA and 81 received MM. All received parenteral antibiotic therapy initiated in the emergency department and continued during hospitalization. There were no significant differences between groups in mean patient age, mean complete blood count total white blood cells count, gender distribution, rates of emergency department fever or rates of intra-abdominal infection (abscess or phlegmon) identified on admission. Compared with patients receiving MM, those receiving EA experienced significantly fewer (1) days of hospitalization, parenteral antibiotic therapy and in-hospital fever; (2) radiographic studies, percutaneous drainage procedures and placement of central venous catheters performed; (3) post admission intra-abdominal complications and (4) unscheduled repeat hospitalizations after hospital discharge. Only 1 EA-managed patient developed a postoperative wound infection. Children with perforated appendicitis who receive EA experience significantly less morbidity and complications versus those receiving MM. The theoretical concern for enhanced morbidity associated with EA management of perforated appendicitis is not supported by our analysis.

Shock-wave properties and high-pressure equations of state of geophysically important materials. Ph.D. Thesis

NASA Technical Reports Server (NTRS)

Boslough, M. B.

1983-01-01

Shock wave (Hugoniot), shock temperature, and release data are presented for several geophysically important, refractory materials. A sensitive multichannel optical pyrometer was developed to measure shock temperatures (2500 to 5600 K at pressures from 48 to 117 GPa) in anorthite (CaAl2Si2O8) glass. Shock temperatures of 3750 to 6000 K at pressures from 140 to 182 GPa were measured in calcium oxide (CaO). Temperature data were used to constrain the energetics of the B1-B2 phase transition at 70 GPa in CaO, and to construct a finite strain equation of state for CaO consistent with previous Hugoniot data. The CaO equation of state was used with equation of state parameters of other oxides to construct a theoretical mixed oxide Hugoniot of anorthite, which is in agreement with new Hugoniot data above about 50 GPa, determined using experimental techniques developed. The mixed oxide model, however, overestimates the shock temperatures, and does not accurately predict measured release paths.

A Controlled-Environment Chamber for Atmospheric Chemistry Studies Using FT-IR Spectroscopy

DTIC Science & Technology

1990-06-01

necessary and identify by block number) FELD GROUP SUB-GROUP i >Chamber, controlled environment; long-path cell ; 07 04 FT-IR; Hydrazine decay...modification doubles the useable path length of the original multipass cell described by White (Reference 8). The pattern of images formed on the nesting...system is shown in Figure 13. 24 z C C02, Ibm, El4 944 C3 ta) caC E-4- 252 14 $4 41) 41) 0. 0 04 04 4 41) ~0 to 0.0 V-4 (A q14 0~ 1% 4-r4 $4 0 u P416 4 4

Candida albicans aggravates duodenal ulcer perforation induced by administration of cysteamine in rats.

PubMed

Nakamura, Tetsuya; Yoshida, Masashi; Ishikawa, Hideki; Kameyama, Kaori; Wakabayashi, Go; Otani, Yoshihide; Shimazu, Motohide; Tanabe, Minoru; Kawachi, Shigeyuki; Kumai, Koichiro; Kubota, Tetsuro; Saikawa, Yoshiro; Sano, Katsuko; Kitajima, Masaki

2007-05-01

Candida sp are frequently isolated from the ascitic fluid of patients with perforated ulcers. The present study was performed to examine whether Candida infection may be involved in the process of ulcer perforation. Male Wistar rats were divided into a saline group (n = 15) and a Candida group (n = 17). Cysteamine-HCl (Sigma; 31 mg/100 g) was administered thrice on day 1 to both groups of animals. Candida albicans at a density of 10(8) in 0.5 mL of saline was administered 1 h before, and 12 h and 24 h after the first administration of cysteamine in the Candida group. Perforated duodenal ulcers were observed in 94.1% of the rats in the Candida group, but only 26.7% of the rats in the saline group (P < 0.01). The area of the duodenal ulcers in the Candida group was 40.89 +/- 33.07 mm2, whereas that in the saline group was 16.53 +/- 20.4 mm2 (P < 0.05). The mortality rate was significantly higher in the Candida group than in the saline group. In the Candida group, colonization by C. albicans was recognized at the ulcer base, surrounded by marked granulocytic infiltration. The number of eosinophils infiltrating the ulcer base was also significantly greater in the Candida group than in the saline group. Immunohistochemical analysis revealed the expression of secretory aspartyl protease (SAP) in the region of the ulcer showing colonization by C. albicans in the Candida group. Candida albicans aggravates duodenal ulcer perforation in the experimental model of cysteamine-induced duodenal ulcer perforation. The present findings suggest that SAP and host-parasite relationships, including granulocyte-dependent mechanisms, may be involved in the aggravation of ulcer perforation by C. albicans.

The management of perforated gastric ulcers.

PubMed

Leeman, Matthew Fraser; Skouras, Christos; Paterson-Brown, Simon

2013-01-01

Perforated gastric ulcers are potentially complicated surgical emergencies and appropriate early management is essential in order to avoid subsequent problems including unnecessary gastrectomy. The aim of this study was to examine the management and outcome of patients with gastric ulcer perforation undergoing emergency laparotomy for peritonitis. Patients undergoing laparotomy at the Royal Infirmary of Edinburgh for perforated gastric ulcers were identified from the prospectively maintained Lothian Surgical Audit (LSA) database over the five-year period 2007-2011. Additional data were obtained by review of electronic records and review of case notes. Forty-four patients (25 male, 19 female) were identified. Procedures performed were: 41 omental patch repairs (91%), 2 simple closures (4.5%) and 2 distal gastrectomies (4.5%; both for large perforations). Four perforated gastric tumours were identified (8.8%), 2 of which were suspected intra-operatively and confirmed histologically, 1 had unexpected positive histology and 1 had negative intra-operative histology, but follow-up endoscopy confirmed the presence of carcinoma (1 positive biopsy in 21 follow-up endoscopies); all 4 were managed without initial resection. Median length of stay was 10 days (range 4-68). Overall 7 patients died in hospital (15.9%) and there were 21 morbidities (54.5%). Registrars performed the majority of the procedures (16 alone, 21 supervised) with no significant difference in post-operative morbidity (P = 0.098) or mortality (P = 0.855), compared to consultants. Almost all perforated gastric ulcers can be effectively managed by laparotomy and omental patch repair. Initial biopsy and follow-up endoscopy with repeat biopsy is essential to avoid missing an underlying malignancy. Copyright © 2013 Surgical Associates Ltd. Published by Elsevier Ltd. All rights reserved.

A method of sealing perforated sinus membrane and histologic finding of bone substitutes: a case report.

PubMed

Shin, Hong-In; Sohn, Dong-Seok

2005-12-01

To augment the atrophic posterior maxilla, a sinus bone graft has been widely used for sinus floor augmentation. Various bone substitutes have been developed and grafted in the maxillary sinus with and without membranes perforation, although autogenous bone is recommended as a gold standard of grafting materials. Membrane perforation is the most common complication associated with sinus bone graft. To repair a perforation, various methods have been developed. This case report is focused on histologic findings of 1 bovine hydroxyapatite (Bio-Oss; Geistlich Pharma AG, Wolhusen, Switzerland) and 2 kinds of human mineral allograft- Tutoplast cancellous microchips (TutoGen Medical GmbH, Neunkirchen am. Brand Germany), and irradiated allogeniccancellous bone and marrow (ICB; Rocky Mountain Tissue Bank, Aurora, CO) used for sinus graft in the same patient with membrane perforation after various healing periods. Mineral allograft showed favorable new bone regeneration with the repair of membrane perforation. This case report also describes a technique regarding how to repair completely perforated sinus membrane after the removal of a mucocele using human collagen membrane (Tutoplast pericardium; TutoGen Medical GmbH) and fibrin adhesive (Greenplast; Green Cross Co., Youngin, Korea) to stabilize collagen membrane.

Methods for Solving Gas Damping Problems in Perforated Microstructures Using a 2D Finite-Element Solver

PubMed Central

Veijola, Timo; Råback, Peter

2007-01-01

We present a straightforward method to solve gas damping problems for perforated structures in two dimensions (2D) utilising a Perforation Profile Reynolds (PPR) solver. The PPR equation is an extended Reynolds equation that includes additional terms modelling the leakage flow through the perforations, and variable diffusivity and compressibility profiles. The solution method consists of two phases: 1) determination of the specific admittance profile and relative diffusivity (and relative compressibility) profiles due to the perforation, and 2) solution of the PPR equation with a FEM solver in 2D. Rarefied gas corrections in the slip-flow region are also included. Analytic profiles for circular and square holes with slip conditions are presented in the paper. To verify the method, square perforated dampers with 16–64 holes were simulated with a three-dimensional (3D) Navier-Stokes solver, a homogenised extended Reynolds solver, and a 2D PPR solver. Cases for both translational (in normal to the surfaces) and torsional motion were simulated. The presented method extends the region of accurate simulation of perforated structures to cases where the homogenisation method is inaccurate and the full 3D Navier-Stokes simulation is too time-consuming.

Fatigue response of perforated titanium for application in laminar flow control

NASA Technical Reports Server (NTRS)

Johnson, W. Steven; Miller, Jennifer L.; Newman, Jr., James

1996-01-01

The room temperature tensile and fatigue response of non-perforated and perforated titanium for laminar flow control application was investigated both experimentally and analytically. Results showed that multiple perforations did not affect the tensile response, but did reduce the fatigue life. A two dimensional finite element stress analysis was used to determine that the stress fields from adjacent perforations did not influence one another. The stress fields around the holes did not overlap one another, allowing the materials to be modeled as a plate with a center hole. Fatigue life was predicted using an equivalent MW flow size approach to relate the experimental results to microstructural features of the titanium. Predictions using flaw sizes ranging from 1 to 15 microns correlated within a factor of 2 with the experimental results by using a flow stress of 260 MPa. By using two different flow stresses in the crack closure model and correcting for plasticity, the experimental results were bounded by the predictions for high applied stresses. Further analysis of the complex geometry of the perforations and the local material chemistry is needed to further understand the fatigue behavior of the perforated titanium.

Hollow organ perforation in blunt abdominal trauma: the role of diagnostic peritoneal lavage.

PubMed

Wang, Yu-Chun; Hsieh, Chi-Hsun; Fu, Chih-Yuan; Yeh, Chun-Chieh; Wu, Shih-Chi; Chen, Ray-Jade

2012-05-01

With recent advances in radiologic diagnostic procedures, the use of diagnostic peritoneal lavage (DPL) has markedly declined. In this study, we reviewed data to reevaluate the role of DPL in the diagnosis of hollow organ perforation in patients with blunt abdominal trauma. Adult patients who had sustained blunt abdominal trauma and who were hemodynamically stable after initial resuscitation underwent an abdominal computed tomographic (CT) scan. Diagnostic peritoneal lavage was performed for patients who were indicated to receive nonoperative management and where hollow organ perforation could not be ruled out. During a 60-month period, 64 patients who had received abdominal CT scanning underwent DPL. Nineteen patients were diagnosed as having a positive DPL based on cell count ratio of 1 or higher. There were 4 patients who sustained small bowel perforation. The sensitivity and specificity of the cell count ratio for a hollow organ perforation in this study were 100% and 75%, respectively. No missed hollow organ perforations were detected. For patients with blunt abdominal trauma and hemoperitoneum who plan to receive nonoperative management, DPL is still a useful tool to exclude hollow organ perforation that is undetected by CT. Copyright © 2012 Elsevier Inc. All rights reserved.

Possible metastable rhombohedral states of the bcc transition metals

NASA Astrophysics Data System (ADS)

Mehl, Michael; Finkenstadt, Daniel

2007-03-01

The energy E(c/a) for a bcc element stretched along its [001] axis (the Bain path) has a minimum at c/a = 1, a maximum at c/a = √2, and an elastically unstable local minimum at c/a > √2. A rhombohedral strain is an alternative method of connecting the bcc and fcc structures. The primitive lattice keeps R3m symmetry, with the angle α changing from 109.4^o (bcc), to 90^o (simple cubic), to 60^o (fcc). We studied this path for the non-magnetic bcc transition metals (V, Nb, Mo, Ta, and W) using both a full-potential LAPW and PAW VASP. Except for Ta, the energy E(α) has a local maximum at α=60^o, with local minima near 55^o and 70^o, the later having lower energy. We studied the elastic stability of the 70^o minimum structure. Only W is elastically stable in this structure, with the smallest eigenvalue of the elastic tensor at 4 GPa, while the other three elements are unstable. We discuss the possibility that Tungsten is actually metastable in this structure. We also consider the possible epitaxial growth of this structure. M. J. Mehl, A. Aguayo, L. L. Boyer, and R. De Coss, Phys. Rev. B 70, 014105 (2004).

Microvascular anatomy of the cerebellar parafloccular perforating space.

PubMed

Sosa, Pablo; Dujovny, Manuel; Onyekachi, Ibe; Sockwell, Noressia; Cremaschi, Fabián; Savastano, Luis E

2016-02-01

The cerebellopontine angle is a common site for tumor growth and vascular pathologies requiring surgical manipulations that jeopardize cranial nerve integrity and cerebellar and brainstem perfusion. To date, a detailed study of vessels perforating the cisternal surface of the middle cerebellar peduncle-namely, the paraflocculus or parafloccular perforating space-has yet to be published. In this report, the perforating vessels of the anterior inferior cerebellar artery (AICA) in the parafloccular space, or on the cisternal surface of the middle cerebellar peduncle, are described to elucidate their relevance pertaining to microsurgery and the different pathologies that occur at the cerebellopontine angle. Fourteen cadaveric cerebellopontine cisterns (CPCs) were studied. Anatomical dissections and analysis of the perforating arteries of the AICA and posterior inferior cerebellar artery at the parafloccular space were recorded using direct visualization by surgical microscope, optical histology, and scanning electron microscope. A comprehensive review of the English-language and Spanish-language literature was also performed, and findings related to anatomy, histology, physiology, neurology, neuroradiology, microsurgery, and endovascular surgery pertaining to the cerebellar flocculus or parafloccular spaces are summarized. A total of 298 perforating arteries were found in the dissected specimens, with a minimum of 15 to a maximum of 26 vessels per parafloccular perforating space. The average outer diameter of the cisternal portion of the perforating arteries was 0.11 ± 0.042 mm (mean ± SD) and the average length was 2.84 ± 1.2 mm. Detailed schematics and the surgical anatomy of the perforating vessels at the CPC and their clinical relevance are reported. The parafloccular space is a key entry point for many perforating vessels toward the middle cerebellar peduncle and lateral brainstem, and it must be respected and protected during surgical approaches to the cerebellopontine angle.

Intracellular Zn(2+) signaling in the dentate gyrus is required for object recognition memory.

PubMed

Takeda, Atsushi; Tamano, Haruna; Ogawa, Taisuke; Takada, Shunsuke; Nakamura, Masatoshi; Fujii, Hiroaki; Ando, Masaki

2014-11-01

The role of perforant pathway-dentate granule cell synapses in cognitive behavior was examined focusing on synaptic Zn(2+) signaling in the dentate gyrus. Object recognition memory was transiently impaired when extracellular Zn(2+) levels were decreased by injection of clioquinol and N,N,N',N'-tetrakis-(2-pyridylmethyl) ethylendediamine. To pursue the effect of the loss and/or blockade of Zn(2+) signaling in dentate granule cells, ZnAF-2DA (100 pmol, 0.1 mM/1 µl), an intracellular Zn(2+) chelator, was locally injected into the dentate molecular layer of rats. ZnAF-2DA injection, which was estimated to chelate intracellular Zn(2+) signaling only in the dentate gyrus, affected object recognition memory 1 h after training without affecting intracellular Ca(2+) signaling in the dentate molecular layer. In vivo dentate gyrus long-term potentiation (LTP) was affected under the local perfusion of the recording region (the dentate granule cell layer) with 0.1 mM ZnAF-2DA, but not with 1-10 mM CaEDTA, an extracellular Zn(2+) chelator, suggesting that the blockade of intracellular Zn(2+) signaling in dentate granule cells affects dentate gyrus LTP. The present study demonstrates that intracellular Zn(2+) signaling in the dentate gyrus is required for object recognition memory, probably via dentate gyrus LTP expression. Copyright © 2014 Wiley Periodicals, Inc.

5. SOUTH SIDE DRIVE AT CHAPEL STRAIGHT. NOTE BIKE PATH ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

5. SOUTH SIDE DRIVE AT CHAPEL STRAIGHT. NOTE BIKE PATH AND BOULDER LANE EDGING. CHAPEL SPIRE AT CENTER. LOCATION OF OLD YOSEMITE VILLAGE AT CENTER DISTANCE. NORTH DOME AT REAR. LOOKING NNE. GIS: N-37 44 21.8 / W-119 35 39.3 - Yosemite National Park Roads & Bridges, Yosemite Village, Mariposa County, CA

Nonsurgical Treatment of Two Periapical Lesions with Calcium Hydroxide Using Two Different Vehicles

PubMed Central

Dixit, Seema; Dixit, Ashutosh; Kumar, Pravin

2014-01-01

Calcium hydroxide is used extensively as an intracanal medicament in endodontics for many years. It is used in various clinical situations such as to promote apexification, to repair perforation, to enhance healing of periapical lesions, to control root resorption, and to control exudation in teeth with persistent periapical inflammation. This paper presents a case report in which Ca(OH)2 was used as an intracanal medicament for treatment of periradicular lesions using two different vehicles in two different teeth of same patient. PMID:25133000

DA-6034-induced mucin secretion via Ca2+-dependent pathways through P2Y receptor stimulation.

PubMed

Lee, Hun; Kim, Eung Kweon; Kim, Ji Yeon; Yang, Yu-Mi; Shin, Dong Min; Kang, Kyung Koo; Kim, Tae-im

2014-09-11

We evaluated whether DA-6034 is involved in mucin secretion via P2Y receptor activation and/or intracellular Ca2+ concentration ([Ca2+]i) change. Also, we investigated the effect of P2Y receptor inhibitors or Ca2+ chelators on the DA-6034-induced mucin secretion and [Ca2+]i increases. Effects of DA-6034 on mucin expression in primary, cultured, conjunctival epithelial cells was studied using RT-PCR, Western blot analysis, and periodic acid-schiff (PAS) staining. To evaluate thin film layer thickness generated by mucin and fluid secretion, cells were incubated in DA-6034 with/without P2Y antagonists or extracellular/intracellular Ca2+ chelators, and were imaged with confocal microscope using Texas Red-dextran dye. In addition, DA-6034-induced Ca2+-dependent Cl- channels opening was evaluated using perforated patch clamp. Fluo-4/AM was used to measure changes in [Ca2+]i induced by DA-6034 in Ca2+-free or Ca2+-containing buffered condition, as well as P2Y antagonists. DA-6034 induced the expression of mucin genes, production of mucin protein, and increase of number of mucin-secreting cells. P2Y antagonists inhibited DA-6034-induced mucin and fluid secretion, which was also affected by extracellular/intracellular Ca2+ chelators. DA-6034 stimulated Cl- channel opening and [Ca2+]i elevation. Further, [Ca2+]i increases induced by DA-6034 were lacking in either P2Y antagonists or Ca2+-free buffered condition, and diminished when endoplasmic reticulum Ca2+ was depleted by cyclopiazonic acid in Ca2+-free buffered condition. This study demonstrated that DA-6034 has a potential to induce mucin secretion via Ca2+-dependent pathways through P2Y receptors in multilayer, cultured, human conjunctival epithelial cells. Copyright 2014 The Association for Research in Vision and Ophthalmology, Inc.

Perforator flap based on the third perforator of the profunda femoris artery (PFA)-assisted closure of the free vertical posteromedial thigh (vPMT) flap donor site.

PubMed

Scaglioni, Mario F; Barth, Andrè A; Chen, Yen-Chou

2018-06-19

The primary closure of the vertical posteromedial thigh (vPMT) free flap donor site is very important to minimize donor site morbidity and maximize cosmetic appearance. However, sometimes due to the dimension of the defect, a vPMT flap is wider than the 8-10 cm requirement. The authors report their experience with the third perforator of the profunda femoris artery (PFA) during the vPMT free flap donor-site closure. Between January 2016 and December 2017, 5 patients underwent reconstruction of lower extremity (2 pts.) and head and neck (3 pts.) area with the free vPMT flaps. Attempts to close the vPMT free flap donor site directly failed due to the flaps' width (average: 11 cm) and pedicled perforator flaps based on the third perforator of the PFA at the distal thigh were harvested to close the defect primary without the use of a skin graft. The size of perforator flap based on 3rd perforator of PFA was on average 6 cm × 4 cm (ranged: 4-8 cm × 3-6 cm). In all patients, the third perforator of the PFA was identified and the perforator diameter was on average 2.0 mm (range, 1.8-2.2 mm). All perforators were musculocutaneous and single. The dimensions of the flaps were on average 6 cm × 4 cm (range: 4 to 8 cm × 3 to 6 cm). All flaps healed uneventfully without complications and the patients were satisfied with cosmetic and functional results at 6 months follow-up. The third perforator of the PFA may be an option to ensure primary closure of the PMT flap donor site, when a larger flap for reconstruction is needed with subsequent impossibility to achieve primary closure of the donor site. © 2018 Wiley Periodicals, Inc.

Beat-to-Beat Variation in Periodicity of Local Calcium Releases Contributes to Intrinsic Variations of Spontaneous Cycle Length in Isolated Single Sinoatrial Node Cells

PubMed Central

Monfredi, Oliver; Maltseva, Larissa A.; Spurgeon, Harold A.; Boyett, Mark R.; Lakatta, Edward G.; Maltsev, Victor A.

2013-01-01

Spontaneous, submembrane local Ca2+ releases (LCRs) generated by the sarcoplasmic reticulum in sinoatrial nodal cells, the cells of the primary cardiac pacemaker, activate inward Na+/Ca2+-exchange current to accelerate the diastolic depolarization rate, and therefore to impact on cycle length. Since LCRs are generated by Ca2+ release channel (i.e. ryanodine receptor) openings, they exhibit a degree of stochastic behavior, manifested as notable cycle-to-cycle variations in the time of their occurrence. Aim The present study tested whether variation in LCR periodicity contributes to intrinsic (beat-to-beat) cycle length variability in single sinoatrial nodal cells. Methods We imaged single rabbit sinoatrial nodal cells using a 2D-camera to capture LCRs over the entire cell, and, in selected cells, simultaneously measured action potentials by perforated patch clamp. Results LCRs begin to occur on the descending part of the action potential-induced whole-cell Ca2+ transient, at about the time of the maximum diastolic potential. Shortly after the maximum diastolic potential (mean 54±7.7 ms, n = 14), the ensemble of waxing LCR activity converts the decay of the global Ca2+ transient into a rise, resulting in a late, whole-cell diastolic Ca2+ elevation, accompanied by a notable acceleration in diastolic depolarization rate. On average, cells (n = 9) generate 13.2±3.7 LCRs per cycle (mean±SEM), varying in size (7.1±4.2 µm) and duration (44.2±27.1 ms), with both size and duration being greater for later-occurring LCRs. While the timing of each LCR occurrence also varies, the LCR period (i.e. the time from the preceding Ca2+ transient peak to an LCR’s subsequent occurrence) averaged for all LCRs in a given cycle closely predicts the time of occurrence of the next action potential, i.e. the cycle length. Conclusion Intrinsic cycle length variability in single sinoatrial nodal cells is linked to beat-to-beat variations in the average period of individual LCRs each cycle. PMID:23826247

Electrophysiological properties of myocytes isolated from the mouse atrioventricular node: L-type ICa, IKr, If, and Na-Ca exchange

PubMed Central

Choisy, Stéphanie C; Cheng, Hongwei; Orchard, Clive H; James, Andrew F; Hancox, Jules C

2015-01-01

The atrioventricular node (AVN) is a key component of the cardiac pacemaker-conduction system. This study investigated the electrophysiology of cells isolated from the AVN region of adult mouse hearts, and compared murine ionic current magnitude with that of cells from the more extensively studied rabbit AVN. Whole-cell patch-clamp recordings of ionic currents, and perforated-patch recordings of action potentials (APs), were made at 35–37°C. Hyperpolarizing voltage commands from −40 mV elicited a Ba2+-sensitive inward rectifier current that was small at diastolic potentials. Some cells (Type 1; 33.4 ± 2.2 pF; n = 19) lacked the pacemaker current, If, whilst others (Type 2; 34.2 ± 1.5 pF; n = 21) exhibited a clear If, which was larger than in rabbit AVN cells. On depolarization from −40 mV L-type Ca2+ current, ICa,L, was elicited with a half maximal activation voltage (V0.5) of −7.6 ± 1.2 mV (n = 24). ICa,L density was smaller than in rabbit AVN cells. Rapid delayed rectifier (IKr) tail currents sensitive to E-4031 (5 μmol/L) were observed on repolarization to −40 mV, with an activation V0.5 of −10.7 ± 4.7 mV (n = 8). The IKr magnitude was similar in mouse and rabbit AVN. Under Na-Ca exchange selective conditions, mouse AVN cells exhibited 5 mmol/L Ni-sensitive exchange current that was inwardly directed negative to the holding potential (−40 mV). Spontaneous APs (5.2 ± 0.5 sec−1; n = 6) exhibited an upstroke velocity of 37.7 ± 16.2 V/s and ceased following inhibition of sarcoplasmic reticulum Ca2+ release by 1 μmol/L ryanodine, implicating intracellular Ca2+ cycling in murine AVN cell electrogenesis. PMID:26607172

Does Navigation Improve Accuracy of Placement of Pedicle Screws in Single-level Lumbar Degenerative Spondylolisthesis?: A Comparison Between Free-hand and Three-dimensional O-Arm Navigation Techniques.

PubMed

Boon Tow, Benjamin Phak; Yue, Wai Mun; Srivastava, Abhishek; Lai, Jenn Ming; Guo, Chang Ming; Wearn Peng, Benedict Chan; Chen, John L T; Yew, Andy K S; Seng, Chusheng; Tan, Seang Beng

2015-10-01

This was a prospective, nonrandomized study. To assess the accuracy of O-arm navigation-based pedicle screw insertion in lumbar degenerative spondylolisthesis and to compare it with free-hand pedicle screw insertion technique in matched population. O-arm navigation is latest in navigation technology that can provide real-time intraoperative images in 3 dimensions while placing the pedicle screws to improve intraoperative pedicle screw accuracy. Degenerative lumbar spondylolisthesis is a locally unstable pathology and placement of pedicle screws can cause increased rotation and translation of the vertebral body. However, is this motion detected by the tracker placed across the unstable segment, is a matter of debate. Inability to detect these positional changes can lead to pedicle perforation while inserting screws using navigation. No study has evaluated the role of O-arm navigation in this patient population. The study population was divided into 2 groups with 19 patients each, one comprising patients who underwent O-arm navigation-based pedicle screw insertion (group 1) and the other comprising patients who underwent free-hand pedicle screw insertion technique (group 2). A total of 152 pedicle screws were implanted in 38 patients for 1-level instrumented fusion for degenerative lumbar spondylolisthesis. Intraoperative 3-dimensional computed tomography scans using the O-arm were obtained for all patients after insertion of pedicle screws. The images were reviewed intraoperatively and postoperatively for the analysis of pedicle breaches. Assessments in either of the group included (i) accuracy of placement of screws; (ii) the rate and direction of perforation; and (iii) the number of segments the perforated screw was away from the navigation tracker. Mean age of patients in group 1 (O-arm navigation-assisted) was 60 years (SD 11.25; range, 37-73 y), whereas in group 2 (free-hand pedicle screw) was 62 years (SD 18.07; range, 36-90 y). Overall anatomic perforation rate was 12.5% (19/152). Individually, group 1 had 14.47% (11/76) of perforations in comparison with 10.53% (8/76) observed in group 2. The difference was not statistically significant. The lateral margin was the most common site of perforation in both group 1 (64%, 7/11) and group 2 (62.5%, 5/8). Functional perforation rate for the series was 3.3% (5/152), with group 1 having 2.63% (2/76) and group 2 having 3.95% (3/76). The rate of perforation (PR) was significantly higher statistically when the tracker was placed 3 or more [PR 37.5% (6/16)] spinal segments away from instrumented segment compared with when it was placed 1 (0%) or 2 [PR 13.89% (5/36)] spinal segments away. Overall, 11 screws (11/152, 7.24%) had grade 2 perforations and had to be revised. No neurological complications were observed in the series. O-arm navigation does not provide any significant advantage over conventional free-hand pedicle screw insertion technique in patients with single-level degenerative spondylolisthesis. The accuracy is dependent on the distance of the tracker from the level of instrumentation. Lateral perforations are more common because of instability at the instrumented level leading to translation and rotation of the vertebral body while placing pedicle screws leading to preferential lateral trajectory. These lateral perforations could not be prevented by using navigation. However, no significant complications were noted in either technique.

The Characteristics of Thin Magnetic Flux Tubes in the Lower Solar Atmosphere Observed by Hinode/SOT in the G band and in Ca II H Bright Points

NASA Astrophysics Data System (ADS)

Xiong, Jianping; Yang, Yunfei; Jin, Chunlan; Ji, Kaifan; Feng, Song; Wang, Feng; Deng, Hui; Hu, Yu

2017-12-01

Photospheric bright points (PBPs) and chromospheric bright points (CBPs) reflect the cross sections of magnetic flux tubes at different heights of the lower solar atmosphere. We aim to study the fine 3D structures and transportation dynamics of the magnetic flux tubes using G-band and simultaneous Ca II H image-series from the Solar Optical Telescope (SOT) on board Hinode. A 3D track-while-detect method is proposed to detect and track PBPs and CBPs. The mean values of equivalent diameters, maximum intensity contrasts, transverse velocities, motion ranges, motion types, and diffusion indices of PBPs and CBPs are 180 ± 20 and 210 ± 30 km, 1.0+/- 0.1< {I}{QS\\_G}> and 1.2+/- 0.1< {I}{QS\\Ca}> , 1.6 ± 0.8 and 2.7 ± 1.4 km s‑1, 1.5 ± 0.6 and 1.7 ± 0.8, 0.8 ± 0.2 and 0.6 ± 0.2, and 1.7 ± 0.7 and 1.3 ± 0.7, respectively. Moreover, the ratios of each CBP characteristics to its corresponding PBP are derived to explore the change rates of the flux tubes. The corresponding ratios are 1.2 ± 0.2, 1.2 ± 0.1, 1.9 ± 0.1, 1.4 ± 0.3, 0.7 ± 0.2, and 0.9 ± 0.4, respectively. The statistical results imply that the majority magnetic flux tubes expand slightly with increasing solar height, look brighter than their surroundings, show a higher transverse velocity, a wider motion range, and a more erratic path, but the majority of the flux tubes diffuse slightly slower. The phenomenon might be explained by the conservation of momentum combined with a decrease in density. The more erratic path leads to a swing or twist of the flux tubes and therefore guides magnetohydrodynamic waves.

New insights to the formation of modern dolomite in a terrestrial low-temperature environment

NASA Astrophysics Data System (ADS)

Zünterl, Andrea; Baldermann, Andre; Boch, Ronny; Dietzel, Martin

2017-04-01

Although dolomite [CaMg(CO3)2] is a rock-forming mineral in ancient carbonate platforms, its occurrence in modern-marine carbonate-depositing settings and in particular in terrestrial, low-temperature environments is scarce - an enigma that is referred to as the "dolomite problem". At present, it is generally accepted that microbial activity, bacterially-mediated sulfate reduction, high aqueous Mg/Ca ratios and anoxic conditions favour the nucleation and crystal growth of dolomite; albeit the precise reaction paths causing the formation of dolomite at low temperatures remain questionable. Here, we present a novel study about the environmental controls and reaction mechanisms leading to the formation of authigenic Mg-Ca carbonates in (active) fault zones of the Erzberg (Styria, Austria) - Europe's largest iron ore opencast mine. Our petrographic and mineralogical results revealed the presence of ˜2-20 cm thick laminated successions of embedded needle-shaped, radiating aragonite and blocky low-Mg calcite (a repetitive sequence also-called "erzbergite") and subsequently deposited (Ca-rich) non-stoichiometric dolomite, which is clogging former voids and unconsolidated sediment in the heavily deteriorated fault zone. First U-Th age determinations of the respective aragonite layers indicate its formation at ˜19,000-13,000 years BP, also suggesting a "young" age of the sedimentary dolomite. Based on the combination of X-ray diffraction and electron microprobe analyses we identified two types of matrix-replacing dolomite: type 1 dolomite is nearly stoichiometric (˜51 mol% CaCO3) and shows a high degree of cation ordering (0.4-0.6), whereas type 2 dolomite is characterized by Ca-excess (˜55 mol% CaCO3) and a low degree of ordering (<0.3). Both types of dolomite grow on the extent of matrix minerals, such as detrital low-Mg calcite, ankerite, siderite, quartz, goethite, chlorite and illitic clay minerals, implying a low-temperature origin of the Ca-excess dolomite and its formation through replacement of CaCO3 precursor phases at high aqueous Mg/Ca ratios of the mineralizing (meteroric) fluids. Further analysis of the δ18O, δ13C, δ26Mg and clumped isotopic (Δ47) signatures of the authigenic Ca-Mg carbonates will give new insights to the physicochemical conditions and reaction paths causing dolomitization in such an exotic, terrestrial environment.

Development of a Multidisciplinary Program to Expedite Care of Esophageal Emergencies.

PubMed

Ceppa, DuyKhanh P; Rosati, Carlo Maria; Chabtini, Lola; Stokes, Samantha M; Cook, Holly C; Rieger, Karen M; Birdas, Thomas J; Lappas, John C; Kessler, William R; DeWitt, John M; Maglinte, Dean D; Kesler, Kenneth A

2017-09-01

Level 1 programs have improved outcomes by expediting the multidisciplinary care of critically ill patients. We established a novel level 1 program for the management of esophageal emergencies. After institutional review board approval, we performed a retrospective analysis of patients referred to our level 1 esophageal emergency program from April 2013 through November 2015. A historical comparison group of patients treated for the same diagnosis in the previous 2 years was used. Eighty patients were referred and transported an average distance of 56 miles (range, 1-163 miles). Median time from referral to arrival was 2.4 hours (range, 0.4-12.9 hours). Referrals included 6 (7%) patients with esophageal obstruction and 71 (89%) patients with suspected esophageal perforation. Of the patients with suspected esophageal perforation, causes included iatrogenic (n = 26), Boerhaave's syndrome (n = 32), and other (n = 13). Forty-six percent (n = 33) of patients were referred because of pneumomediastinum, but perforation could not be subsequently demonstrated. Initial management of patients with documented esophageal perforation included operative treatment (n = 25), endoscopic intervention (n = 8), and supportive care (n = 5). Retrospective analysis demonstrated a statistically significant difference in mean Pittsburgh severity index score (PSS) between esophageal perforation treatment groups (p < 0.01). In patients with confirmed perforations, there were 3 (8%) mortalities within 30 days. More patients in the esophageal level 1 program were transferred to our institution in less than 24 hours after diagnosis than in the historical comparison group (p < 0.01). Development of an esophageal emergency referral program has facilitated multidisciplinary care at a high-volume institution, and early outcomes appear favorable. Copyright © 2017 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

A shovel with a perforated blade reduces energy expenditure required for digging wet clay.

PubMed

Harivanam, Sridhar; Marklin, Richard W; Papanek, Paula E; Cariapa, Vikram

2010-08-01

A shovel with a blade perforated with small holes was tested to see whether a worker would use less whole-body energy to dig wet clay than with a shovel with an opaque blade. A perforated shovel is hypothesized to require less whole-body energy on the basis of adhesion theory; a smaller surface area would require less physical effort to dig and release soil from the blade. The study involved 13 workers from an electric utility who dug wet clay with two 1.5-m long-handled point shovels, which differed only in blade design (perforated and opaque). Oxygen consumption was measured with a portable system while each worker dug wet clay at a self-regulated pace for 10 min. There was no significant difference in number of scoops dug during the 10-min sessions, but workers dug 9.5% more weight of clay with the perforated shovel than with the conventional shovel (404 kg vs. 369 kg, respectively). Furthermore, stable oxygen uptake normalized to weight of participant and to the weight of clay dug revealed that participants expended 11.7% less relative energy per kilogram of clay dug with the perforated shovel. A point shovel with a perforated blade is recommended for digging and shoveling wet clay. However, the extra weight that workers chose to dig with the perforated shovel may increase the loading on the spine and may offset the metabolic advantages. Manual shoveling is a common task, and workers may experience less whole-body and muscle fatigue when using a perforated shovel.

Electro-Optic Propagation

DTIC Science & Technology

2003-09-30

Electro - Optic Propagation Stephen Doss-Hammel SPAWARSYSCEN San Diego code 2858 49170 Propagation Path San Diego, CA 92152-7385 phone: (619...scenarios to extend the capabilities of TAWS to surface and low altitude situations. OBJECTIVES The electro - optical propagation objectives are: 1...development of a new propagation assessment tool called EOSTAR ( Electro - Optical Signal Transmission and Ranging). The goal of the EOSTAR project is to

Rare Earth Element Concentrations and Fractionation Patterns Along Groundwater Flow Paths in Two Different Aquifer Types (i.e., Sand vs. Carbonate)

NASA Astrophysics Data System (ADS)

Johannesson, K. H.; Tang, J.

2003-12-01

Groundwater samples were collected in two different types of aquifer (i.e., Carrizo Sand Aquifer, Texas and Upper Floridan carbonate Aquifer, west-central Florida) to study the concentrations, fractionation, and speciation of rare earth elements (REE) along groundwater flow paths in each aquifer. Major solutes and dissolved organic carbon (DOC) were also measured in these groundwaters. The Carrizo Sand aquifer was sampled in October 2002 and June 2003, whereas, to date, we have only sampled the Floridan once (i.e., June 2003). The data reveal no significant seasonal differences in major solute and REE concentrations for the Carrizo. In Carrizo sand aquifer, groundwaters from relatively shallow wells (i.e., less than 167 m) in the recharge zone are chiefly Ca-Na-HCO3-Cl type waters. With flow down-gradient the groundwaters shift composition to the Na-HCO3 waters. pH and alkalinity initially decrease with flow away from the recharge zone before increasing again down-gradient. DOC is generally low (0.65 mg/L) along the flow path. REE concentrations are highest in groundwaters from the recharge zone (Nd 40.5 pmol/kg), and decrease substantially with flow down-gradient reaching relatively low and stable values (Nd 4.1-8.6 pmol/kg) roughly 10 km from the recharge zone. Generally, Carrizo groundwaters exhibit HREE-enriched shale-normalized patterns. The HREE enrichments are especially strong for waters from the recharge zone [(Yb/Nd)SN =1.7-5.6], whereas down-gradient (deep) groundwaters have flatter patterns [(Yb/Nd)SN =0.7-2.5]. All groundwaters have slightly positive Eu anomalies (Eu/Eu* 0.09-0.14) and negative Ce anomalies (Ce/Ce* -0.85 - -0.07). In the Upper Floridan Aquifer, Ca, Mg, SO4, and Cl concentrations generally increase along groundwater flow path, whereas pH and alkalinity generally decrease. DOC is higher (0.64 - 2.29 mg/L) than in the Carrizo and initially increases along the flow path and then decreases down-gradient. LREE (Nd) concentrations generally increase along groundwater flow path, however, MREE (Gd) exhibit little change and HREE (Yb) concentrations tend to decreases along the flow path. Floridan groundwaters have HREE enriched shale-normalized patterns, although (Yb/Nd)SN values decrease along groundwater flow path. Thus, REE patterns of Floridan groundwaters tend to flatten with flow down-gradient. All groundwaters show positive Eu anomalies (0.06 - 0.17) and negative Ce anomalies (-0.12 - -0.63).

Association of Health Care Utilization With Rates of Perforated Appendicitis in Children 18 Years or Younger.

PubMed

Baxter, Katherine J; Nguyen, Hannah T M H; Wulkan, Mark L; Raval, Mehul V

2018-06-01

The pediatric perforated appendix rate is a quality metric measured by the Agency for Healthcare Research and Quality (AHRQ) that reflects access to care. The association of health care utilization prior to presentation with appendicitis is unknown. To determine whether increased health care utilization prior to presentation with appendicitis is associated with lower perforated appendicitis rates in children. Retrospective cohort study of privately insured children drawn from large employer and insurance company administrative data found in the Truven MarketScan national insurance claims database. Cases of appendicitis were identified among 38 348 children 18 years or younger from January 1, 2010, through December 31, 2013, with corresponding primary health care encounters from January 1, 2009, through December 31, 2012. In all, 19 109 eligible children were identified using International Classification of Diseases, Ninth Revision (ICD-9) diagnosis codes for appendicitis after excluding those patients who did not have continuous insurance coverage during the study period. Statistical analysis was performed from September 1, 2016, to October 15, 2017. Health care utilization was determined by the number of outpatient clinic encounters for each patient in the 1 to 12 months before presentation with appendicitis. Perforated appendicitis was defined according to the AHRQ by using ICD-9 codes for perforation and hospital length of stay of 3 or more days. Logistic regression models were used for perforated appendicitis after adjustment for age, sex, income, gastrointestinal comorbidities, geographic region, and insurance type. We identified 38 348 children 18 years or younger with ICD-9 diagnosis codes for appendicitis, and 19 109 children remained for analysis after applying exclusion criteria. Of these, 11 422 were boys (59.8%); the mean (SD) age was 12.4 (3.9) years. Of the 19 109 children identified who underwent appendectomy, 5509 (28.8%) presented with perforated appendicitis. Children with perforation had lower outpatient health care utilization in the year before presentation compared with those diagnosed with acute appendicitis (4554 of 5509 children [82.7%] vs 11 937 of 13 600 [87.8%]; P < .001). In the adjusted model, outpatient health care utilization before presentation was associated with lower odds of perforated appendicitis (odds ratio [OR], 0.63; 95% CI, 0.58-0.69; P < .001). This association increased with visit frequency in the year before presentation (OR, 0.86; 95% CI, 0.77-0.95 for 1-2 visits, P = .003; OR, 0.61; 95% CI, 0.55-0.67 for 3-6 visits, P < .001; and OR, 0.43; 95% CI, 0.38-0.48 for ≥7 visits [5-18 years], P < .001). Covariates associated with perforation included younger age, geographic region, family income, and higher out-of-pocket insurance plans. Among insured children 18 years or younger, increased health care utilization was associated with lower rates of perforated appendicitis. Primary health care relationships may facilitate timely presentation or serve as a marker for health-related self-efficacy, thereby contributing to outcomes for acute surgical conditions.

Predictors of Corneal Perforation or Need for Therapeutic Keratoplasty in Severe Fungal Keratitis: A Secondary Analysis of the Mycotic Ulcer Treatment Trial II.

PubMed

Prajna, N Venkatesh; Krishnan, Tiruvengada; Rajaraman, Revathi; Patel, Sushila; Shah, Ranjeet; Srinivasan, Muthiah; Das, Manoranjan; Ray, Kathryn J; Oldenburg, Catherine E; McLeod, Stephen D; Zegans, Michael E; Acharya, Nisha R; Lietman, Thomas M; Rose-Nussbaumer, Jennifer

2017-09-01

Identifying patients with infectious keratitis who are at risk of experiencing a poor outcome may be useful to allocate resources toward high-risk patients, particularly in resource-poor settings. To determine baseline patient and ulcer characteristics that predict a high risk of developing corneal perforation and/or the need to undergo therapeutic penetrating keratoplasty (TPK). This is a secondary analysis of Mycotic Ulcer Treatment Trial II, a multicenter, double-masked, placebo-controlled randomized clinical trial that enrolled 240 patients with smear-positive filamentous fungal corneal ulcers who enrolled between May 2010 and August 2015. Participants had a baseline visual acuity of 20/400 or worse and were randomized to receive oral voriconazole or a placebo (all participants received topical voriconazole, 1%). After 39 participants (16.3%) were enrolled, topical natamycin, 5%, was also added. The primary outcome of this secondary analysis was the rate of corneal perforation or the need to undergo TPK. The mean (SD) age at enrollment was 49 (13) years, 104 participants (43.3%) were women, and all were of Southeast Asian descent. The presence of hypopyon at baseline indicated 2.28 times the odds of the patient developing corneal perforation and/or needing TPK (95% CI, 1.18-4.40; P = .01). Study participants whose infiltrate involved the posterior one-third had a 71.4% risk of developing corneal perforation and/or needing TPK. For each 1-mm increase in the geometric mean of the infiltrate, there was 1.37 (95% CI, 1.12-1.67; P = .002) increased odds of developing perforation and/or needing TPK. Other clinical features such as visual acuity, baseline culture positivity, type of filamentous fungal organism and duration of symptoms, and demographic characteristics, such as sex and occupation, were not significant predictors in the multivariable regression analysis. These results suggest that risk stratification from baseline ulcer characteristics can identify those at highest risk for developing corneal perforation and/or needing TPK. clinicaltrials.gov Identifier: NCT00996736.

Numerical investigation of the interaction of positive streamers with bubbles floating on a liquid surface

NASA Astrophysics Data System (ADS)

Babaeva, Natalia Yu.; Naidis, George V.; Kushner, Mark J.

2016-09-01

Streamer discharges in air intersecting with liquids are being investigated to produce reactivity in the liquid. In this talk, we discuss results from a 2-d computational investigation of streamers in air intersecting an isolated liquid, air filled bubble floating on a liquid surface. The 15 mm diameter bubble is conducting water (ɛ /ɛ0 = 80 , σ = 7 . 5 ×10-4Ω-1cm-1) or transformer oil (ɛ /ɛ0 = 2 . 2 , σ = 1 . 5 ×10-13Ω-1cm-1). A needle electrode is positioned d =0-10 mm from the bubble center. With a water bubble (d =0) the streamer slides along the external surface but does not penetrate the bubble due to electric field screening by the conducting shell. If the electrode is shifted (d =3-10 mm) the streamer deviates from the vertical and adheres to the bubble. If the electrode is inserted inside the bubble, the streamer path depends on how deep the electrode penetrates. For shallow penetration, the streamer propagates along the inner surface of the bubble. For deep penetration the streamer takes the shortest path down through the gas. Due to the low conductivity of the oil bubble shell the electric field penetrates into the interior of the bubble. The streamer can then be re-initiated inside the bubble. Charge accumulation on both sides of the bubble shell and perforation of the shell will be also discussed. NYB, GVN supported by Russian Sci. Found. (14-12-01295). MJK by US Natl. Sci. Found. and Dept. of Energy.

Impact of cartilage graft size on success of tympanoplasty.

PubMed

Abdelhameed, Waleed; Rezk, Ibrahim; Awad, Alhussein

In the last decade, there has been an increasing use of cartilage grafts in the primary repair of tympanic membrane perforations. The major advantages of cartilage are its stiffness and its very low metabolic requirements, which make it particularly suitable for difficult conditions, such as subtotal perforations, adhesive otitis and reoperation. To analyze the impact of different perforation sizes requiring different sizes of cartilage on the anatomical and functional outcome after tympanoplasty. Through this prospective non-controlled, non-randomized study, 50 patients underwent cartilage type 1 tympanoplasty (20 females and 30 males), with a mean age of 19.3±9.8 years. According to size of perforation, patients were subdivided into three groups, Group I had perforation >50% of tympanic membrane area, in Group II patients the perforations were 25-50% of tympanic membrane area, and in Group III the perforations were ≤25% of tympanic membrane. All patients had pre and postoperative Pure Tone Average and Air Bone Gap frequencies (0.5, 1, 2, 4kHz). All patients were followed up at least 12 months after operation. The anatomical success rate among all patients was 92%, all groups showed statistical significant improvement between pre and postoperative air bone gap, no significant correlation between size of cartilage graft and degree of air bone gap improvement was noticed among the three groups. Size of a cartilage graft has no impact on degree of hearing improvement or anatomical success rate after tympanoplasty. Copyright © 2016 Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facial. Published by Elsevier Editora Ltda. All rights reserved.

G9a/GLP histone lysine dimethyltransferase complex activity in the hippocampus and the entorhinal cortex is required for gene activation and silencing during memory consolidation.

PubMed

Gupta-Agarwal, Swati; Franklin, Aimee V; Deramus, Thomas; Wheelock, Muriah; Davis, Robin L; McMahon, Lori L; Lubin, Farah D

2012-04-18

Learning triggers alterations in gene transcription in brain regions such as the hippocampus and the entorhinal cortex (EC) that are necessary for long-term memory (LTM) formation. Here, we identify an essential role for the G9a/G9a-like protein (GLP) lysine dimethyltransferase complex and the histone H3 lysine 9 dimethylation (H3K9me2) marks it catalyzes, in the transcriptional regulation of genes in area CA1 of the rat hippocampus and the EC during memory consolidation. Contextual fear learning increased global levels of H3K9me2 in area CA1 and the EC, with observable changes at the Zif268, DNMT3a, BDNF exon IV, and cFOS gene promoters, which occurred in concert with mRNA expression. Inhibition of G9a/GLP in the EC, but not in the hippocampus, enhanced contextual fear conditioning relative to control animals. The inhibition of G9a/GLP in the EC induced several histone modifications that include not only methylation but also acetylation. Surprisingly, we found that downregulation of G9a/GLP activity in the EC enhanced H3K9me2 in area CA1, resulting in transcriptional silencing of the non-memory permissive gene COMT in the hippocampus. In addition, synaptic plasticity studies at two distinct EC-CA1 cellular pathways revealed that G9a/GLP activity is critical for hippocampus-dependent long-term potentiation initiated in the EC via the perforant pathway, but not the temporoammonic pathway. Together, these data demonstrate that G9a/GLP differentially regulates gene transcription in the hippocampus and the EC during memory consolidation. Furthermore, these findings support the possibility of a role for G9a/GLP in the regulation of cellular and molecular cross talk between these two brain regions during LTM formation.

Use of Computed Tomography to Determine Perforation in Patients With Acute Appendicitis.

PubMed

Gaskill, Cameron E; Simianu, Vlad V; Carnell, Jonathan; Hippe, Daniel S; Bhargava, Puneet; Flum, David R; Davidson, Giana H

Urgent appendectomy has long been the standard of care for acute appendicitis. Six randomized trials have demonstrated that antibiotics can safely treat appendicitis, but approximately 1 in 4 of these patients eventually requires appendectomy. Overall treatment success may be limited by complex disease including perforation. Patients׳ success on antibiotic therapy may depend on preoperative identification of complex disease on imaging. However, the effectiveness of computed tomography (CT) in differentiating complex disease including perforated from nonperforated appendicitis remains to be determined. The purpose of this study was to assess the preoperative diagnostic accuracy of CT in determining appendiceal perforation in patients operated for acute appendicitis. We performed a retrospective review of pathology and radiology reports from consecutive patients who presented to the emergency department with suspicion for acute appendicitis between January 2012 and May 2015. CT scans were re-reviewed by abdominal imaging fellowship-trained radiologists using standardized criteria, and the radiologists were blinded to pathology and surgical findings. Radiologists specifically noted presence or absence of periappendiceal gas, abscess, appendicolith, fat stranding, and bowel wall thickening. The overall radiologic impression as well as these specific imaging findings was compared to results of pathology and operative reports. Pathology reports were considered the standard for diagnostic accuracy. Eighty-nine patients (65% male, average age of 34 years) presenting with right lower quadrant pain underwent CT imaging and prompt appendectomy. Final pathology reported perforation in 48% (n = 43) of cases. Radiologic diagnosis of perforation was reported in 9% (n = 8), correctly identifying perforation in 37.5% (n = 3), and incorrectly reporting perforation in 62.5% of nonperforated cases per pathology. Radiology missed 93% (n = 40) of perforations postoperatively diagnosed by pathology. There was no secondary finding (fat stranding, diameter >13mm, abscess, cecal wall thickening, periappendiceal gas, simple fluid collection, appendicolith, and phlegmon) with a clinically reliable sensitivity or specificity to predict perforated appendicitis. Surgeon׳s report of perforation was consistent with the pathology report of perforation in only 28% of cases. The usefulness of a CT for determining perforation in acute appendicitis is limited, and methods to improve precision in identifying patients with complicated appendicitis should be explored as this may help for improving risk prediction for failure of treatment with antibiotic therapy and help guide patients and providers in shared decision-making for treatment options. Copyright © 2017 Elsevier Inc. All rights reserved.

Two cases of bowel perforation associated with sunitinib treatment for renal cell carcinoma.

PubMed

Hoshino, Yoshinori; Hasegawa, Hirotoshi; Ishii, Yoshiyuki; Endo, Takashi; Ochiai, Hiroki; Okabayashi, Koji; Kaneko, Gou; Mikami, Shuji; Mukai, Makio; Oya, Mototsugu; Kitagawa, Yuko

2012-08-01

Sunitinib, a multitargeted tyrosine kinase inhibitor, is widely used in the treatment of carcinoma. Adverse events associated with this treatment, including fatigue, diarrhea, and hematotoxicity, have been reported in clinical trials. Bowel perforation is a surgical emergency that requires immediate treatment depending on the location and progression of the tumor. We report 2 cases of bowel perforation during sunitinib treatment. The patients presented with diffuse peritonitis, and emergency exploratory laparotomy was performed. We speculate that the underlying mechanisms were decrease in capillary density of the normal mucosa in case 1 and tumor shrinkage because of sunitinib treatment in case 2. To the best of our knowledge, this is the first study to report the pathological findings implicating bowel perforation due to sunitinib treatment. Further investigations are needed to clarify the risk factors for intestinal perforations associated with sunitinib treatment.

Reconstruction of lower face defect or deformity with submental artery perforator flaps.

PubMed

Shi, Cheng-li; Wang, Xian-cheng

2012-07-01

Reconstruction of lower face defects or deformity often presents as a challenge for plastic surgeons. Many methods, including skin graft, tissue expander, or free flap are introduced. Submental artery perforator flaps have been used in the reconstruction of defects or deformities of the lower face. Between August 2006 and December 2008, 22 patients with lower face defects or deformity underwent reconstruction with pedicled submental artery perforator flaps. Their age ranged between 14 and 36 years. The perforator arteries were detected and labeled with a hand-held Doppler flowmeter. The size of flaps ranged from 4 × 6 to 6 × 7 cm, and the designed flaps included the perforator artery. All the flaps survived well, except 1 flap which resulted in partial necrosis in distal region and healed after conservative therapy. No other complication occurred with satisfactory aesthetic appearance of the donor site. The submental artery perforator flap is a thin and reliable flap with robust blood supply. This flap can reduce donor-site morbidity significantly and is a good choice for reconstructive surgery of lower face.

Finite element modeling of sound transmission with perforations of tympanic membrane

PubMed Central

Gan, Rong Z.; Cheng, Tao; Dai, Chenkai; Yang, Fan; Wood, Mark W.

2009-01-01

A three-dimensional finite element (FE) model of human ear with structures of the external ear canal, middle ear, and cochlea has been developed recently. In this paper, the FE model was used to predict the effect of tympanic membrane (TM) perforations on sound transmission through the middle ear. Two perforations were made in the posterior-inferior quadrant and inferior site of the TM in the model with areas of 1.33 and 0.82 mm2, respectively. These perforations were also created in human temporal bones with the same size and location. The vibrations of the TM (umbo) and stapes footplate were calculated from the model and measured from the temporal bones using laser Doppler vibrometers. The sound pressure in the middle ear cavity was derived from the model and measured from the bones. The results demonstrate that the TM perforations can be simulated in the FE model with geometrical visualization. The FE model provides reasonable predictions on effects of perforation size and location on middle ear transfer function. The middle ear structure-function relationship can be revealed with multi-field coupled FE analysis. PMID:19603881

Experimental and Theoretical Analysis of Sound Absorption Properties of Finely Perforated Wooden Panels.

PubMed

Song, Boqi; Peng, Limin; Fu, Feng; Liu, Meihong; Zhang, Houjiang

2016-11-22

Perforated wooden panels are typically utilized as a resonant sound absorbing material in indoor noise control. In this paper, the absorption properties of wooden panels perforated with tiny holes of 1-3 mm diameter were studied both experimentally and theoretically. The Maa-MPP (micro perforated panels) model and the Maa-Flex model were applied to predict the absorption regularities of finely perforated wooden panels. A relative impedance comparison and full-factorial experiments were carried out to verify the feasibility of the theoretical models. The results showed that the Maa-Flex model obtained good agreement with measured results. Control experiments and measurements of dynamic mechanical properties were carried out to investigate the influence of the wood characteristics. In this study, absorption properties were enhanced by sound-induced vibration. The relationship between the dynamic mechanical properties and the panel mass-spring vibration absorption was revealed. While the absorption effects of wood porous structure were not found, they were demonstrated theoretically by using acoustic wave propagation in a simplified circular pipe with a suddenly changed cross-section model. This work provides experimental and theoretical guidance for perforation parameter design.

Recurrent gastric perforation as a late complication of radiotherapy for mucosa-associated lymphoid tissue lymphoma of the stomach.

PubMed

Otsuka, Taiga; Noda, Takahiro; Yokoo, Masako; Ibaraki, Kazuo

2008-01-01

Radiation therapy can be used to treat Helicobacter pylori-negative or eradication-refractory extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT) of the stomach. We report a case of gastric perforation which occurred more than 1 year after the completion of radiotherapy for H. pylori eradication-refractory gastric MALT lymphoma, and then recurred shortly afterwards. This was considered to be a late complication of radiation toxicity. Although gastric perforation due to radiotherapy has been reported very rarely in the past, even in advanced disease, this case shows that perforation can develop in patients with superficial disease and can relapse.

[Conversion Therapy of Initially Unresectable Rectal Cancer with Perforation via FOLFOX4 Chemotherapy].

PubMed

Yamada, Chizu; Ishikawa, Fumihiko; Nitta, Hiroshi; Fujita, Yoshihisa; Omoto, Hideyuki; Kamata, Shigeyuki; Ito, Hiroshi

2015-11-01

We describe a case of perforated rectal cancer that became curatively resectable after FOLFOX4 chemotherapy. An 81- year-old woman was transferred to our hospital with a diagnosis of bowel perforation. She underwent emergency transverse colostomy, peritoneal lavage, and the insertion of indwelling drainage tubes, because the perforated rectal cancer was considered unresectable. After recuperation, she received chemotherapy consisting of FOLFOX4 and bevacizumab. Owing to a good response to the treatment after 4 months, rectal resection was achieved curatively. Wound dehiscence occurred as a postoperative complication. The patient chose not to receive adjuvant chemotherapy. Currently, she has been alive for more than 1 year 3 months after resection without recurrence.

Comparison of features and outcomes of perforated peptic ulcer between Malaysians and foreigners.

PubMed

Kugan, V; Mahadevan, D T; Kandasami, P

2016-02-01

Perforated peptic ulcers (PPU) present as serious surgical emergencies that carry high mortality and morbidity. Foreigners with PPU are also managed in our hospital setting. Their inclusion significantly alters the trend and pattern of PPU seen in Malaysia. To compare per-operative and post-operative features and outcomes of perforated peptic ulcers between Malaysians and foreigners. This was an analytical crosssectional study. All patients who underwent repair of perforated peptic ulcer disease during a 6-year period were included. 50 consecutive patients' records with perforated peptic ulcer were analysed. Data were collected from operation theatre database and hospital medical records. Chi square and t test were performed using SPSS statistical software. Total of 50 patients, of which 30 were Malaysians and 20 were foreigners. The mean age of Malaysian patients was 58.3 ± 15.2 years whereas the mean age for foreign patients was 30.3 ± 6.7 years, with foreign patients being significantly younger than local patients. Foreigners had significantly smaller ulcers with only 5% of them having ulcers more than 1cm while 36.7% of Malaysian patients had ulcers more than 1cm. Post-operative complications are significantly higher in Malaysian patients (p<0.05) with 40% of Malaysian patients and 10% of foreign patients developing post-operative complications. Foreign patients are younger with significantly smaller perforated ulcers and better post-operative outcomes.

Heterogeneous strain and composite P-T paths: the key for unravelling complex tectonic histories in polymetamorphic high-grade terrains

NASA Astrophysics Data System (ADS)

van Reenen, Dirk D.; Smit, C. Andre

2010-05-01

Leonid Perchuk calculated the first P-T paths for eclogites almost 40 years ago [1] and since then he has shown that P-T paths if correctly constructed, represent an accurate record of the thermal and dynamic evolution of high-grade metamorphic complexes [2]. This implies that P-T paths might serve as the basis for geodynamic models for the formation and exhumation of such complexes from the lower crustal levels [2]. His continued research in the Limpopo Complex of southern Africa also played an important role in the next direction in the study of complex high-grade polymetamorphic complexes. This new direction involves the link between composite (kinked) P-T paths [5; 6; 8] and the critical role of heterogeneous strain in the development and preservation of distinct granulite facies events at the regional, outcrop, hand specimen, and thin section scales [7; 9; 10]. Heterogeneous deformation that operated on the thin section scale allowed the construction of kinked P-T paths from single thin sections [5; 6; 9] and the integration of the P-T data with structural and isotopic geochronology [7; 9; 10]. D-P-T-t paths thus constructed not only allow the nature of polymetamorphism in the Limpopo Complex of southern Africa to be established, but also assisted in the construction of tectonic models for the evolution of this complex high-grade polymetamorphic complex. This complex evolution is demonstrated by the configuration of a kinked P-T path (5; 9) that reflects the following distinct stages of the multi-cycle D-P-T-t evolution of the Central Zone: (i) the earliest DC1 path reflects the emplacement before ~2.63Ga of the Limpopo Complex at the crustal level of ~20km. The DC1 stage of the D1/M1 exhumation event was accompanied by the formation of early D2A isoclinal folds; (ii) The DC2 stage of the D1/M1 exhumation event reflects the emplacement before ~2.61Ga of the rocks at the crustal level of ~15km. The DC2 stage was accompanied by the formation of major D2B sheath folds; (iii) the high-grade rocks resided and cooled at this crustal level in the Central Zone of the Limpopo Complex for more than 600Ma before the rocks were again reheated at ~2.02Ga during a superimposed D2/M2 high-grade event. This event is reflected by an isobaric-heating (IC) P-T path that resulted in the widespread formation of polymetamorphic granulites; (iv) the IC path was followed a DC3 P-T path that reflects the final exhumation of the rocks to the upper crustal level during the D2/M2 event. High-grade D3A shear zones controlled the final exhumation of the rocks. Isobaric heating (IC) thus links Pmin (D1/M1) to Pmax (D2/M2) that resulted in a kinked configuration of the DC1/2=>IC=>DC3 P-T path. The end of the high-grade tectono-metamorphic event is signified by the development at ~2.01Ga of completely undeformed melt patches that destroy the D2B and D3A gneissic fabric of the rocks in which they are developed. Reactivation of SW-NE-trending high-grade D3A shear zones at ~1.9Ga resulted in the formation of upper crustal mylonitic shear zones that define the present belt-like geometry of the SW-NE trending Limpopo Complex. The successful link of composite (kinked) P-T paths with structural (D) and geochronological (t) data t formed the basis for the construction of D-P-T-t diagrams that demonstrate the polymetamorphic evolution of the Limpopo Complex as the result of superimposed Neoarchaean and Paleoproterozoic high-grade events. References: [1] Perchuk L.L. Physics of the Earth and Planetary Interiors, 1976. 13, 232-239. [2] Perchuk L.L. (1989) Geol. Soc. London. Special Publication. 2(20). 275-291. [3] Roering, C., Van Reenen, D.D., Smit, C.A., Barton, J.M. jr., de Beer, J.H., de Wit, M.J., Stettler, E.H., van Schalkwyk., J.F., Stevens, G., and Pretorius, S. 1992. Precambrian Research, 55, 539-552. [4] Gerya, T.V., Perchuk, L.L., Van Reenen, D.D., and Smit, C.A. 2000. J. Geodynamics, 30, 17-35. [5] Perchuk L.L. (2005) Dokl. Earth Sciences. 401. 311-314. [6] Perchuk, L.L., Gerya, T.V., Van Reenen, D.D., and Smit, C.A. 2006. Petrology, v. 14, no. 2, 131-167. [7] Mahan, K. H., Goncalves, P., Flowers, R. M., Williams, M. L., and Hoffman-Setka, D., 2008. Journal of Metamorphic Geology, DOI:10.1111/j.1525-1314. [8] Perchuk, L. L., van Reenen, D. D., Varlamov, D. A., van Kal, S. M., Tabatabaeimanesh, S. M., and Boshoff, R., 2008. Lithos, v. 103, p. 70-105. [9] Perchuk, L.L. and Van Reenen, D.D., 2008. Lithos, 106, 403-410. [10]. Van Reenen, D. D., Boshoff, R., Smit, C. A., Perchuk, L.L., Kramers, J. D.,McCourt, S. M., and Armstrong, R. A., 2008. Gondwana Research, v.14, p. 644-662.

Conservative management of esophageal perforations during pneumatic dilation for idiopathic esophageal achalasia.

PubMed

Vanuytsel, Tim; Lerut, Toni; Coosemans, Willy; Vanbeckevoort, Dirk; Blondeau, Kathleen; Boeckxstaens, Guy; Tack, Jan

2012-02-01

Esophageal perforation is the most serious adverse event of pneumatic dilation (PD) for achalasia; it is usually managed by surgical repair. We investigated risk factors for esophageal perforation after PD and evaluated safety and long-term outcome of nonsurgical management strategies. We analyzed medical records of patients with achalasia who were treated with PD from 1992-2010 at the University Hospital Gasthuisberg in Leuven, Belgium; all patients with esophageal perforation were contacted to determine long-term outcomes. Achalasia outcomes were assessed by using the Vantrappen criteria. Of 830 PD procedures performed on 372 patients with manometry-confirmed achalasia (57 ± 1 years, 51% male), 16 were complicated by transmural esophageal perforation (4.3% of patients, 1.9% of dilations). Age >65 years was the only significant risk factor for complications (odds ratio, 3.5; 95% confidence interval, 1.2-10.2). All patients were treated conservatively with broad-spectrum antibiotics and nothing by mouth. In 6 patients (38%) the clinical course was further complicated by a pleural effusion, which required a drain in 4 patients. One patient (6%) died of mediastinal hemorrhage within 12 hours after PD. Patients with complications were discharged after 19 ± 2.3 days, compared with 4 ± 0.2 days for those without complications (P < .0001). Long-term outcomes (mean follow-up, 84 ± 14 months) were determined for 12 patients (75%); 11 had excellent or good outcomes (69%), and 1 had a moderate outcome (6%). Age >65 years is a significant risk factor for esophageal perforation after PD. Nonsurgical management of transmural esophageal tears is feasible, with favorable short-term and long-term outcomes, but is not devoid of complications. Copyright © 2012 AGA Institute. Published by Elsevier Inc. All rights reserved.

Association of mortality with out-of-hours admission in patients with perforated peptic ulcer.

PubMed

Knudsen, N V; Møller, M H

2015-02-01

Perforated peptic ulcer is a serious emergency surgical condition. The aim of the present nationwide cohort study was to evaluate the association between mortality and out-of-hours admission in patients surgically treated for perforated peptic ulcer. All Danish patients surgically treated for benign gastric or duodenal perforated peptic ulcer in Denmark between September 1, 2011 and August 31, 2013 were included. Patients were identified through The Danish Clinical Register of Emergency Surgery. The association between 90-day mortality and time and day of admission and surgery was assessed by crude and adjusted odds ratios (ORs) with 95% confidence intervals (CIs). A total of 726 patients were included. Median age was 69.5 years (range 18.2-101.7), and 569 of the 726 patients (78.4%) had at least one coexisting disease. Adjusted ORs and 95% CIs between 90-day mortality and admission in daytime vs. nighttime and weekday vs. weekend were 1.0 (0.7-1.5) and 1.2 (0.8-1.8), respectively. Adjusted ORs with 95% CI between surgery in daytime vs. nighttime and weekday vs. weekend were 0.9 (0.6-1.3) and 1.2 (0.8-1.8), respectively. Sensitivity analysis was consistent with the primary analysis. The overall 90-day mortality rate was 25.6% (186/726). No statistically significant adjusted association between 90-day mortality and out-of-hours admission was found in patients surgically treated for perforated peptic ulcer. © 2014 The Acta Anaesthesiologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

Coextrusion-Based 3D Plotting of Ceramic Pastes for Porous Calcium Phosphate Scaffolds Comprised of Hollow Filaments.

PubMed

Jo, In-Hwan; Koh, Young-Hag; Kim, Hyoun-Ee

2018-05-29

This paper demonstrates the utility of coextrusion-based 3D plotting of ceramic pastes (CoEx-3DP) as a new type of additive manufacturing (AM) technique, which can produce porous calcium phosphate (CaP) ceramic scaffolds comprised of hollow CaP filaments. In this technique, green filaments with a controlled core/shell structure can be produced by coextruding an initial feedrod, comprised of the carbon black (CB) core and CaP shell, through a fine nozzle in an acetone bath and then deposited in a controlled manner according to predetermined paths. In addition, channels in CaP filaments can be created through the removal of the CB cores during heat-treatment. Produced CaP scaffolds had two different types of pores with well-defined geometries: three-dimensionally interconnected pores (~360 × 230 μm² in sizes) and channels (>100 μm in diameter) in hollow CaP filaments. The porous scaffolds showed high compressive strengths of ~12.3 ± 2.2 MPa at a high porosity of ~73 vol % when compressed parallel to the direction of the hollow CaP filaments. In addition, the mechanical properties of porous CaP scaffolds could be tailored by adjusting their porosity, for example, compressive strengths of 4.8 ± 1.1 MPa at a porosity of ~82 vol %. The porous CaP scaffold showed good biocompatibility, which was assessed by in vitro cell tests, where several the cells adhered to and spread actively with the outer and inner surfaces of the hollow CaP filaments.

[Applied anatomy of the perforating branches artery and its distally-based flap of sural nerve nutrient vessels].

PubMed

Zhang, Fahui; Xie, Qiyang; Zheng, Heping

2005-07-01

To investigate the distribution of the perforating branches artery of distally-based flap of sural nerve nutrient vessels and its clinical application. The origins and distribution of perforating branches artery of distally-based flap were observed on specimens of 30 adult cadaveric low limbs by perfusing red gelatin to dissect the artery. Among the 36 cases, there were 21 males, 15 females. Their ages ranged from 6 to 66, 35. 2 in average. The defect area was 3.5 cm x 2.5 cm to 17.0 cm x 11.0 cm. The flap taken ranged from 4 cm x 3 cm to 18 cm x 12 cm. The perforating branches artery of distally-based flap had 2 to 5 branches and originated from the heel lateral artery, the terminal perforating branches of peroneal artery (diameters were 0.6+/-0.2 mm and 0.8+/-0.2 mm, 1.0 +/- 1.3 cm and 2.8 +/- 1.0 cm to the level of cusp lateral malleolus cusp). The intermuscular septum perforating branches of peroneal artery had 0 to 3 branches. Their rate of presence was 96.7%, 66.7% and 20.0% respectively (the diameters were 0.9 +/- 0.3, 1.0 +/- 0.2 and 0.8 +/- 0.4 mm, and their distances to the level of cusp of lateral malleolus were 5.3 +/- 2.1, 6.8 +/- 2.8 and 7.0 +/- 4.0 cm). Those perforating branches included fascia branches, cutaneous branches, nerve and vein nutrient branches. Those nutrient vessels formed longitudinal vessel chain of sural nerve shaft, vessel chain of vein side and vessel network of deep superficial fascia. The distally-based superficial sural artery island flap was used in 18 cases, all flaps survived. Distally-based sural nerve, small saphenous vein, and nutrient vessels of fascia skin have the same origin. Rotation point of flap is 3.0 cm to the cusp of lateral malleolus, when the distally-based flap is pedicled with the terminal branch of peroneal artery. Rotation point of flap is close to the cusp of lateral malleolus, when the distally-based flap is pedicled with the heel lateral artery.

Development, Fabrication, and Characterization of Hydrogel Based Piezoresistive Pressure Sensors with Perforated Diaphragms

PubMed Central

Orthner, M.P.; Buetefisch, Sebastian; Magda, J.; Rieth, L.W.; Solzbacher, F.

2010-01-01

Hydrogels have been demonstrated to swell in response to a number of external stimuli including pH, CO2, glucose, and ionic strength making them useful for detection of metabolic analytes. To measure hydrogel swelling pressure, we have fabricated and tested novel perforated diaphragm piezoresistive pressure sensor arrays that couple the pressure sensing diaphragm with a perforated semi-permeable membrane. The 2×2 arrays measure approximately 3 × 5 mm2 and consist of four square sensing diaphragms with widths of 1.0, 1.25, and 1.5 mm used to measure full scale pressures of 50, 25, and 5 kPa, respectively. An optimized geometry of micro pores was etched in silicon diaphragm to allow analyte diffusion into the sensor cavity where the hydrogel material is located. The 14-step front side wafer process was carried out by a commercial foundry service (MSF, Frankfurt (Oder), Germany) and diaphragm pores were created using combination of potassium hydroxide (KOH) etching and deep reactive ion etching (DRIE). Sensor characterization was performed (without the use of hydrogels) using a custom bulge testing apparatus that simultaneously measured deflection, pressure, and electrical output. Test results are used to quantify the sensor sensitivity and demonstrate proof-of-concept. Simulations showed that the sensitivity was slightly improved for the perforated diaphragm designs while empirical electrical characterization showed that the perforated diaphragm sensors were slightly less sensitive than solid diaphragm sensors. This discrepancy is believed to be due to the influence of compressive stress found within passivation layers and poor etching uniformity. The new perforated diaphragm sensors were fully functional with sensitivities ranging from 23 to 252 μV/V-kPa (FSO= 5 to 80mV), and show a higher nonlinearity at elevated pressures than identical sensors with solid diaphragms. Sensors (1.5×1.5 mm2) with perforated diaphragms (pores=40 μm) have a nonlinearity of approximately 10% while for the identical solid diaphragm sensor it was roughly 3 % over the entire 200 kPa range. This is the first time piezoresistive pressure sensors with integrated diffusion pores for detection of hydrogel swelling pressure have been fabricated and tested. PMID:20657810

The use of 137Cs to establish longer-term soil erosion rates on footpaths in the UK.

PubMed

Rodway-Dyer, S J; Walling, D E

2010-10-01

There is increasing awareness of the damage caused to valuable and often unique sensitive habitats by people pressure as degradation causes a loss of plant species, disturbance to wildlife, on-site and off-site impacts of soil movement and loss, and visual destruction of pristine environments. This research developed a new perspective on the problem of recreational induced environmental degradation by assessing the physical aspects of soil erosion using the fallout radionuclide caesium-137 ((137)Cs). Temporal sampling problems have not successfully been overcome by traditional research methods monitoring footpath erosion and, to date, the (137)Cs technique has not been used to estimate longer-term soil erosion in regard to sensitive recreational habitats. The research was based on-sites within Dartmoor National Park (DNP) and the South West Coast Path (SWCP) in south-west England. (137)Cs inventories were reduced on the paths relative to the reference inventory (control), indicating loss of soil from the path areas. The Profile Distribution Model estimated longer-term erosion rates (ca. 40 years) based on the (137)Cs data and showed that the combined mean soil loss for all the sites on 'paths' was 1.41 kg m(-2) yr(-1) whereas the combined 'off path' soil loss was 0.79 kg m(-2) yr(-1), where natural (non-recreational) soil redistribution processes occur. Recreational pressure was shown to increase erosion in the long-term, as greater soil erosion occurred on the paths, especially where there was higher visitor pressure. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

Imaging the Morphotectonic Setting of Seismic Events and Their Propagation Paths: Methodology and Comparative Studies.

DTIC Science & Technology

1991-03-20

Suite 1212 California Institute of Technology Resron, VA 22091 Pasadena, CA 91125 Mr. William J. Best Prof. F. A. Dahlen 907 Westwood Drive...P.O. Box 1620 La Jolla, CA 92038-1620 2 Prof. William Menke Prof. Charles G. Sammis Lamont-Doherty Geological Observatory Center for Earth Sciences...Cruz, CA 95064 3, Prof. Terry C. Wallace Department of Geosciences Building #77 University of Arizona Tucson, AZ 85721 Dr. William Wortman Mission

Developing a phenomenological model of the proton trajectory within a heterogeneous medium required for proton imaging.

PubMed

Fekete, Charles-Antoine Collins; Doolan, Paul; Dias, Marta F; Beaulieu, Luc; Seco, Joao

2015-07-07

To develop an accurate phenomenological model of the cubic spline path estimate of the proton path, accounting for the initial proton energy and water equivalent thickness (WET) traversed. Monte Carlo (MC) simulations were used to calculate the path of protons crossing various WET (10-30 cm) of different material (LN300, water and CB2-50% CaCO3) for a range of initial energies (180-330 MeV). For each MC trajectory, cubic spline trajectories (CST) were constructed based on the entrance and exit information of the protons and compared with the MC using the root mean square (RMS) metric. The CST path is dependent on the direction vector magnitudes (|P0,1|). First, |P0,1| is set to the proton path length (with factor Λ(Norm)(0,1) = 1.0). Then, two optimal factor Λ(0,1) are introduced in |P0,1|. The factors are varied to minimize the RMS difference with MC paths for every configuration. A set of Λ(opt)(0,1) factors, function of WET/water equivalent path length (WEPL), that minimizes the RMS are presented. MTF analysis is then performed on proton radiographs of a line-pair phantom reconstructed using the CST trajectories. Λ(opt)(0,1) was fitted to the WET/WEPL ratio using a quadratic function (Y = A + BX(2) where A = 1.01,0.99, B = 0.43,-  0.46 respectively for Λ(opt)(0), Λ(opt)(1)). The RMS deviation calculated along the path, between the CST and the MC, increases with the WET. The increase is larger when using Λ(Norm)(0,1) than Λ(opt)(0,1) (difference of 5.0% with WET/WEPL = 0.66). For 230/330 MeV protons, the MTF10% was found to increase by 40/16% respectively for a thin phantom (15 cm) when using the Λ(opt)(0,1) model compared to the Λ(Norm)(0,1) model. Calculation times for Λ(opt)(0,1) are scaled down compared to MLP and RMS deviation are similar within standard deviation.B ased on the results of this study, using CST with the Λ(opt)(0,1) factors reduces the RMS deviation and increases the spatial resolution when reconstructing proton trajectories.

Posterior repair with perforated porcine dermal graft.

PubMed

Taylor, G Bernard; Moore, Robert D; Miklos, John R; Mattox, T Fleming

2008-01-01

To compare postoperative vaginal incision separation and healing in patients undergoing posterior repair with perforated porcine dermal grafts with those that received grafts without perforations. Secondarily, the tensile properties of the perforated and non-perforated grafts were measured and compared. This was a non-randomized retrospective cohort analysis of women with stage II or greater rectoceles who underwent posterior repair with perforated and non-perforated porcine dermal grafts (Pelvicol(TM) CR Bard Covington, GA USA). The incidence of postoperative vaginal incision separation (dehiscence) was compared. A secondary analysis to assess graft tensile strength, suture pull out strength, and flexibility after perforation was performed using standard test method TM 0133 and ASTM bending and resistance protocols. Seventeen percent of patients (21/127) who received grafts without perforations developed vaginal incision dehiscence compared to 7% (5/71) of patients who received perforated grafts (p = 0.078). Four patients with vaginal incision dehiscence with non-perforated grafts required surgical revision to facilitate healing. Neither tensile strength or suture pull out strength were significantly different between perforated and non-perforated grafts (p = 0.81, p = 0.29, respectively). There was no difference in the flexibility of the two grafts (p = 0.20). Perforated porcine dermal grafts retain their tensile properties and are associated with fewer vaginal incision dehiscences.

[Repair of soft tissue defect in hand or foot with lobulated medial sural artery perforator flap].

PubMed

Fengjing, Zhao; Jianmin, Yao; Xingqun, Zhang; Liang, Ma; Longchun, Zhang; Yibo, Xu; Peng, Wang; Zhen, Zhu

2015-11-01

To explore the clinical effect of the lobulated medial sural artery perforator flap in repairing soft tissue defect in hand or foot. Since March 2012 to September 2014, 6 cases with soft tissue defects in hands or feet were treated by lobulated medial sural artery flaps pedicled with 1st musculo-cutaneous perforator and 2st musculo-cutaneous perforator of the medial sural artery. The size of the flaps ranged from 4.5 cm x 10.0 cm to 6.0 cm x 17.0 cm. 5 cases of lobulated flap survived smoothly, only 1 lobulated flap had venous articulo, but this flap also survived after the articulo was removed by vascular exploration. All flaps had desirable appearance and sensation and the two-point discrimination was 6 mm in mean with 4 to 12 months follow-up (average, 7 months). Linear scar was left in donor sites in 3 cases and skin scar in 3 cases. There was no malfunction in donor sites. Lobulated medial sural artery perforator flap is feasible and ideal method for the treatment of soft tissue defect in hand or foot with satisfactory effect.

Natural orifice transluminal endoscopic surgery for patients with perforated peptic ulcer.

PubMed

Bonin, Eduardo A; Moran, Erica; Gostout, Christopher J; McConico, Andrea L; Zielinski, Martin; Bingener, Juliane

2012-06-01

Perforation accounts for 70% of deaths attributed to peptic ulcers. Laparoscopic repair is effective but infrequently used. Our aim was to assess how many patients with perforated peptic ulcer could be candidates for a transluminal endoscopic omental patch closure. This retrospective study reviewed patients with perforated peptic ulcer from 2005 to 2010. Demographics, ulcer characteristics, operative procedure, and outcomes were recorded. Candidates for endoscopic transluminal repair were defined as those having undergone omental patch closure of an ulcer of appropriate size and no contraindications to laparoscopy or endoscopy. In the retrospective review, a total of 104 patients were identified; 62% female, mean age = 68 years, mean ASA of 3, and 63% medication-related ulcers. Fifty-nine (63%) had an omental patch (80% open), and 35 (37%) had other procedures. Ten patients had nonoperative management. Thirty-day mortality was 14% and 1 year mortality was 35%. Forty-nine patients (52%) were considered potential candidates for transluminal repair. Sixty-three percent of our patients sustained a medication-related perforation with 1 year mortality of 35%. The majority of patients were treated using open omental patch repair. Transluminal endoscopic repair may provide an additional situation for a minimally invasive approach for a number of these patients.

Incidence of Appendicitis over Time: A Comparative Analysis of an Administrative Healthcare Database and a Pathology-Proven Appendicitis Registry

PubMed Central

Clement, Fiona; Zimmer, Scott; Dixon, Elijah; Ball, Chad G.; Heitman, Steven J.; Swain, Mark; Ghosh, Subrata

2016-01-01

Importance At the turn of the 21st century, studies evaluating the change in incidence of appendicitis over time have reported inconsistent findings. Objectives We compared the differences in the incidence of appendicitis derived from a pathology registry versus an administrative database in order to validate coding in administrative databases and establish temporal trends in the incidence of appendicitis. Design We conducted a population-based comparative cohort study to identify all individuals with appendicitis from 2000 to2008. Setting & Participants Two population-based data sources were used to identify cases of appendicitis: 1) a pathology registry (n = 8,822); and 2) a hospital discharge abstract database (n = 10,453). Intervention & Main Outcome The administrative database was compared to the pathology registry for the following a priori analyses: 1) to calculate the positive predictive value (PPV) of administrative codes; 2) to compare the annual incidence of appendicitis; and 3) to assess differences in temporal trends. Temporal trends were assessed using a generalized linear model that assumed a Poisson distribution and reported as an annual percent change (APC) with 95% confidence intervals (CI). Analyses were stratified by perforated and non-perforated appendicitis. Results The administrative database (PPV = 83.0%) overestimated the incidence of appendicitis (100.3 per 100,000) when compared to the pathology registry (84.2 per 100,000). Codes for perforated appendicitis were not reliable (PPV = 52.4%) leading to overestimation in the incidence of perforated appendicitis in the administrative database (34.8 per 100,000) as compared to the pathology registry (19.4 per 100,000). The incidence of appendicitis significantly increased over time in both the administrative database (APC = 2.1%; 95% CI: 1.3, 2.8) and pathology registry (APC = 4.1; 95% CI: 3.1, 5.0). Conclusion & Relevance The administrative database overestimated the incidence of appendicitis, particularly among perforated appendicitis. Therefore, studies utilizing administrative data to analyze perforated appendicitis should be interpreted cautiously. PMID:27820826

Changing patterns in the surgical treatment of perforated duodenal ulcer - single centre experience.

PubMed

Budzyński, Piotr; Pędziwiatr, Michał; Grzesiak-Kuik, Agata; Natkaniec, Michał; Major, Piotr; Matłok, Maciej; Stanek, Maciej; Wierdak, Mateusz; Migaczewski, Marcin; Pisarska, Magdalena; Budzyński, Andrzej

2015-09-01

Although the surgical treatment of patients with perforated duodenal ulcer is the method of choice, the introduction of effective pharmacotherapy has changed the surgical strategy. Nowadays less extensive procedures are chosen more frequently. The introduction of laparoscopic procedures had a significant impact on treatment results. To present our experience in the treatment of perforated duodenal ulcer in two periods, by comparing open radical anti-ulcer procedures with laparoscopic ulcer repair. The analysis covered patients operated on for perforated duodenal ulcer. Two groups of patients were compared. Group 1 included 245 patients operated on in the period 1980-1994 with a traditional method (pyloroplasty + vagotomy) before introduction of proton pump inhibitors (PPI). Group 2 included 106 patients treated in the period 2000-2014 with the laparoscopic technique supplemented with PPI therapy. Groups were compared in terms of patients' demographic structure, operative time, complication rate and mortality. The mean operative time in group 1 was shorter than in group 2 (p < 0.0001). Complications were noted in 57 (23.3%) patients in group 1 and 14 (13.5%) patients in group 2 (p = 0.0312). Reoperation was necessary in 13 (5.3%) cases in group 1 and in 5 cases in group 2 (p = 0.8179). The mortality rate in group 1 was significantly higher than in group 2 (10.2% vs. 2.8%, p = 0.0192). In group 1, median length of hospital stay was 9 days and differed significantly from group 2 (6 days, p < 0.0001). Within the last 30 years, significant changes in treatment of perforated peptic ulcer (PPU) have occurred, mainly related to abandoning routine radical anti-ulcer procedures and replacing the open technique with minimally invasive surgery. Thus it was possible to improve treatment results by reducing complication and mortality rates, and shortening the length of hospital stay. Although the laparoscopic operation is longer, it improves outcomes. In the authors' opinion, in each patient with suspected peptic ulcer perforation, laparoscopy should be the method of choice.

Glove perforations and blood contact associated with manipulation of the fetal scalp electrode.

PubMed

Rhoton-Vlasak, A; Duff, P

1993-02-01

To assess prospectively the frequency of glove injury associated with insertion of the fetal scalp electrode and subsequent examination of the cervix with the electrode in place. Over a 7-month period, sterile gloves were collected after use for insertion of the fetal scalp electrode or cervical examination with the electrode in place. Attendants indicated their level of training, time, date and purpose of glove use, and cervical examination. They also noted whether they were aware of a glove perforation or observed blood, amniotic fluid, or genital tract secretions on their hand. Glove patency was assessed by filling the glove with water to 1.5-2.0 times its normal volume and observing for leaks. One hundred unused gloves were tested for patency and served as controls. Five hundred one gloves were evaluated, of which 13 (2.6%, 95% confidence interval [Cl] 1-4%) had perforations. Seven of 277 gloves (2.5%) used only for examinations had perforations, compared with six of 244 (2.5%) used only for insertion of the electrode. Two percent (95% CI 0-5%) of the unused control gloves had perforations. These observed differences were not statistically significant. Nineteen attendants (3.8%, 95% CI 2.1-5.5%) noted blood or genital tract secretions on their hand after insertion of the electrode (N = 4) or subsequent cervical examination (N = 15). Only one point of contract resulted from a glove perforation; the other 18 were on the wrist and apparently resulted from leakage of fluid around the open cuff of the glove. The risk of glove perforation during insertion of the fetal scalp electrode or subsequent cervical examination is low if proper technique is observed. Blood or fluid contact is more likely to result from leakage of fluid around the open cuff of the glove during a vaginal examination.

Role of laparoscopy in peritonitis.

PubMed

Sangrasi, Ahmed Khan; Talpu, K Altaf Hussain; Kella, Nandlal; Laghari, Abdul Aziz; Rehman Abbasi, Mujeeb; Naeem Qureshi, Jawaid

2013-07-01

Laparoscopy has gained clinical acceptance in many subspecialties in the last decade. The conventional open surgery for peritonitis carries significant morbidity and mortality. The present study was done to extend and evaluate benefits of minimally invasive surgery in this subset of patients. This was a prospective study spanning over a period of four years. All those patients diagnosed as having peritonitis on clinical assessment and preoperative investigations and those who were stable enough haemodynamically were included in this study. After initial resuscitation for few hours, they underwent diagnostic and therapeutic laparoscopy to identify the cause of peritonitis and to confirm the pathology. All cases were done under general anesthesia, using three standard ports at appropriate sites according to pathology. Patients were treated by different procedures either laparoscopically or with laparoscopic assistance after diagnosis. Operative and post operative data was collected and analyzed. Ninety two cases of peritonitis underwent diagnostic and therapeutic laparoscopy. Mean age of patient was 46.5 years. 24 patients were diagnosed as perforated duodenal, in 14 (58.3%) patients laparoscopic suture repair was done and in 8 (33.3%) small upper midline incision was given and perforation was repaired. Out of 32 patients having perforated appendix, 25 (78.1%) patients laparoscopic appendectomy was done while in 7 (21.8%) perforation was dealt by laparoscopic assistance. Out of 14 patients of ileal perforation 6 (42.8%) with minimal contamination laparoscopic suture was applied, while in 8 (57.1%), perforated loop was brought out by making small window and perforation was closed. All 22 patients with pelvic sepsis needed only aspiration of pus and peritoneal lavage. Only one patient died post operatively and 2 (2.1%) patients developed fistula. 6 (6.5%) patients developed port site infection. Laparoscopic management is feasible, safe and effective surgical option for patients with peritonitis due to different abdominal emergencies in properly selected cases with higher diagnostic yield and a faster postoperative recovery.

Comparison of pre-filter and post-filter ionised calcium monitoring in continuous veno-venous hemodiafiltration (CVVHD-F) with citrate anti-coagulation.

PubMed

Brain, Matthew J; Roodenburg, Owen S; McNeil, John

2017-01-01

It is widespread practice during citrate anticoagulated renal replacement therapy to monitor circuit ionised calcium (iCa2+) to evaluate the effectiveness of anticoagulation. Whether the optimal site to sample the blood path is before or after the haemofilter is a common question. Using a prospectively collected observational dataset from intensive care patients receiving pre-dilution continuous veno-venous haemodiafiltration (CVVHD-F) with integrated citrate anticoagulation we compared paired samples of pre and post filter iCa2+ where the target range was 0.3-0.5 mmol.L-1 as well as concurrently collected arterial iCa2+. Two nested mixed methods linear models were fitted to the data describing post vs pre filter iCa2+, and the relationship of pre, post and arterial samples. An 11 bed general intensive care unit. 450 grouped samples from 152 time periods in seven patients on CRRT with citrate anticoagulation. The relationship of post to pre-filter iCa2+ was not 1:1 with post = 0.082 + 0.751 x pre-filter iCa2+ (95% CI intercept: 0.015-0.152, slope 0.558-0.942). Variation was greatest between patients rather than between circuits within the same patient or citrate dose. Compared to arterial iCa2+ there was no significant difference between pre and post-filter sampling sites (F-value 0.047, p = 0.827). These results demonstrate that there is minimal difference between pre and post filter samples for iCa2+ monitoring of circuit anticoagulation in citrate patients relative to the arterial iCa2+ in CVVHD-F however compared to pre-filter sampling, post filter sampling has a flatter response and greater variation.

Comparison of pre-filter and post-filter ionised calcium monitoring in continuous veno-venous hemodiafiltration (CVVHD-F) with citrate anti-coagulation

PubMed Central

Roodenburg, Owen S.; McNeil, John

2017-01-01

Background It is widespread practice during citrate anticoagulated renal replacement therapy to monitor circuit ionised calcium (iCa2+) to evaluate the effectiveness of anticoagulation. Whether the optimal site to sample the blood path is before or after the haemofilter is a common question. Methods Using a prospectively collected observational dataset from intensive care patients receiving pre-dilution continuous veno-venous haemodiafiltration (CVVHD-F) with integrated citrate anticoagulation we compared paired samples of pre and post filter iCa2+ where the target range was 0.3–0.5 mmol.L-1 as well as concurrently collected arterial iCa2+. Two nested mixed methods linear models were fitted to the data describing post vs pre filter iCa2+, and the relationship of pre, post and arterial samples. Setting An 11 bed general intensive care unit. Participants 450 grouped samples from 152 time periods in seven patients on CRRT with citrate anticoagulation. Results The relationship of post to pre-filter iCa2+ was not 1:1 with post = 0.082 + 0.751 x pre-filter iCa2+ (95% CI intercept: 0.015–0.152, slope 0.558–0.942). Variation was greatest between patients rather than between circuits within the same patient or citrate dose. Compared to arterial iCa2+ there was no significant difference between pre and post-filter sampling sites (F-value 0.047, p = 0.827) Conclusion These results demonstrate that there is minimal difference between pre and post filter samples for iCa2+ monitoring of circuit anticoagulation in citrate patients relative to the arterial iCa2+ in CVVHD-F however compared to pre-filter sampling, post filter sampling has a flatter response and greater variation. PMID:29272278

Gastric perforation secondary to metastasis from breast cancer.

PubMed

Wong, Chee Siong; Gumber, Ashutosh; Kiruparan, Pasupathy; Blackmore, Alexander

2016-07-18

Gastric perforation secondary to metastasis from breast cancer occurs infrequently. We present the case of a 72-year-old postmenopausal female patient with a known history of lobular carcinoma of the breast who presented to a district general hospital with a clinical diagnosis of an acute abdomen. Further contrast-enhanced CT scan demonstrated free gas and fluid in the abdomen. She underwent emergency exploratory laparotomy and onlay Graham's omentopexy patch due to 1×1 cm prepyloric gastric perforation. Final histopathology proved the presence of metastatic malignant cells in the breast origin. We discuss the issues involved in postoperative investigation and management. 2016 BMJ Publishing Group Ltd.

Downregulation of IL-4-induced signalling in hippocampus contributes to deficits in LTP in the aged rat.

PubMed

Maher, F O; Nolan, Yvonne; Lynch, Marina A

2005-05-01

Ageing is characterized by deficits in learning and memory and by a deficit in long-term potentiation (LTP) in hippocampus. Several age-related changes, including dysfunction of calcium homeostatic mechanisms and upregulation of inflammatory processes are likely to contribute to these deficits. Here we exploited the fact that aged rats fall into a subgroup which fail to sustain LTP in perforant path granule cell synapses as a result of tetanic stimulation, and a subgroup which sustains LTP in a manner indistinguishable from young rats, in an effort to identify differential changes in the two subgroups. The age-related increase in IL-1beta concentration and IL-1beta-induced signalling was more profound in aged rats which failed to sustain LTP. We demonstrate that functional IL-4 receptors are expressed in rat hippocampus and that age is associated with a decrease in IL-4 concentration accompanied by a decrease in phosphorylation of JAK-1 and STAT-6. We propose that the imbalance between pro-inflammatory and anti-inflammatory cytokines in the aged brain significantly contributes to age-related deficits in synaptic function.

Cerebral Perforating Artery Disease : Characteristics on High-Resolution Magnetic Resonance Imaging.

PubMed

Liang, Jianye; Liu, Yiyong; Xu, Xiaoshuang; Shi, Changzheng; Luo, Liangping

2018-03-23

Our aims were to evaluate the feasibility of high-resolution magnetic resonance imaging (HR-MRI) for displaying the cerebral perforating arteries in normal subjects and to discuss the value of HR-MRI for detecting the causes of infarctions in the territory of the lenticulostriate artery (LSA). Included in this study were 31 healthy subjects and 28 patients who had infarctions in the territory supplied by the LSA. The T1-weighted imaging (T1WI), T2WI, diffusion-weighted imaging (DWI), and HR-MRI, including 3‑dimensional time-of-flight magnetic resonance angiography (3D-TOF-MRA) and 3D fast spin-echo T1WI (namely CUBE T1 in GE Healthcare), were applied on a 3-Tesla scanner. The numbers and route of the perforating arteries on both sides were independently confirmed on HR-MRI by two physicians. The Wilcoxon test was used to compare the differences. The numbers of perforating arteries in healthy subjects observed on 3D-TOF-MRA were as follows: numbers of the bilateral recurrent artery of Heubner (RAH) ranged from 0-3 (median 1), numbers of the left LSA ranged from 0-7 (median 3), numbers of the right LSA ranged from 0-5 (median 3), numbers of the bilateral anterior choroidal artery ranged from 1-2 (median 1) and the numbers of the bilateral thalamoperforating artery ranged from 1-2 (median 1). In the patients with lenticulostriate infarctions, the numbers of LSAs on the affected side were lower than on the opposite and ipsilateral sides in the healthy subjects. The results were statistically significant. An abnormality of the RAH may lead to a centrum semiovale infarct pattern, whereas an abnormality of the LSA is associated with a corona radiata infarct pattern. The use of HR 3D-TOF-MRA and CUBE T1 had unique advantages in displaying the tiny perforating arteries in vivo. Moreover, effective recognition of the associated cerebral perforating artery and infarct patterns may enhance our understanding of the mechanism of stroke in patients with lenticulostriate infarctions.

Petrography and zircon U-Pb isotopic study of the Bayanwulashan Complex: Constrains on the Paleoproterozoic evolution of the Alxa Block, westernmost North China Craton

NASA Astrophysics Data System (ADS)

Wu, Sujuan; Hu, Jianmin; Ren, Minghua; Gong, Wangbin; Liu, Yang; Yan, Jiyuan

2014-11-01

The Bayanwulashan Metamorphic Complex (BMC) exposes along the eastern margin of the Alxa Block, the westernmost part of the North China Craton (NCC). BMC is principally composed of metamorphic rocks with amphibole plagiogneiss, biotite plagioclase gneiss and granitic gneiss. Our research has been focused on the petrography and zircon U-Pb geochronology of the BMC to better understand the evolution of the Alxa Block and its relationship with the NCC. Evidences from field geology, petrography, and mineral chemistry indicate that two distinct metamorphic assemblages, the amphibolite and greenschist facies, had overprinted the preexisting granitic gneiss and suggest that the BMC experienced retrograde metamorphic episodes. The LA-ICP-MS zircon U-Pb ages reveal that the primary magmatic activities of BMC were at ca. 2.30-2.24 Ga and the two metamorphic events were at ca. 1.95-1.91 Ga and ca. 1.88-1.85 Ga respectively. These ages indicate that BMC initially intruded during Paleoproterozoic, not as previously suggested at Archean period. The Early Paleoproterozoic metamorphic records and the magmatic thermochronological data in BMC exhibit different evolution paths between the Alxa Block and the NCC. The Alxa Block was most likely an independent Early Paleoproterozoic terrain. Following different amalgamation processes, The Alxa Block combined with Western Block at ca. 1.95 Ga and then united with NCC at ca. 1.85 Ga.

Could an abdominal drainage be avoided in complicated acute appendicitis? Lessons learned after 1300 laparoscopic appendectomies.

PubMed

Schlottmann, Francisco; Reino, Romina; Sadava, Emmanuel E; Campos Arbulú, Ana; Rotholtz, Nicolás A

2016-12-01

Complicated appendicitis (CA) may be a risk factor for postoperative intra-abdominal abscess formation (IAA). In addition, several publications have shown an increased risk of postoperative collection after laparoscopic appendectomy. Most surgeons prefer to place a drain to collect contaminated abdominal fluid to prevent consequent abscess formation. We aimed to evaluate the utility of placing an intra-abdominal drain in laparoscopic appendectomy for complicated acute appendicitis. From January 2005 to June 2015 all charts of consecutive patients who underwent laparoscopic appendectomy for CA were revised. CA was defined as a perforated appendix with associated peritonitis. The sample was divided into two groups, G1: intra-abdominal drain and G2: no drain. Demographics, operative factors and 30-day postoperative complications were analyzed. In the study period 1300 laparoscopic appendectomies were performed. Laparoscopic findings showed that 17.3% of the surgeries were for complicated acute appendicitis (225 patients). Fifty-six patients (25%) were in G1 and 169 patients (75%) in G2. No significant differences in clinical presentation and demographics were found (p: NS). G1 had an increased conversion rate (G1: 19.6% vs. G2: 7.1%; p: 0.007). No differences were found in the overall morbidity (G1: 32.1% vs. G2: 21.3%, p: NS). The rate of postoperative IAA was 14.2% in G1 and 8.9% in G2 (p: NS). Length of stay was higher in G1 (G1: 5.2 days vs. G2 2.9 days, p: 0.001). There was no mortality in either group. The placement of intra-abdominal drain in complicated acute appendicitis may not present benefits and may even lengthen hospital stay. These observations suggest that there is no need of using a drain in laparoscopic appendectomy for complicated acute appendicitis. Copyright © 2016 IJS Publishing Group Ltd. Published by Elsevier Ltd. All rights reserved.

Colorectal cancer with intestinal perforation - a retrospective analysis of treatment outcomes.

PubMed

Banaszkiewicz, Zbigniew; Woda, Łukasz; Tojek, Krzysztof; Jarmocik, Paweł; Jawień, Arkadiusz

2014-01-01

Colorectal cancer (CRC) is one of the leading cause of death in European population. It progresses without any symptoms in the early stages or those clinical symptoms are very discrete. The aim of this study was a retrospective analysis of treatment outcomes in patients with colorectal cancer complicated with intestinal perforation. A retrospective analysis of patients urgently operated upon in our Division of General Surgery, because of large intestine perforation, from February 1993 to February 2013 has been made. Results were compared with a group of patients undergoing the elective surgery for colorectal cancer in the same time and Division. Intestinal perforation occurred more often in males (6.52% vs. 6.03%), patients with mucous component in histopathological examination (9.09% vs. 6.01%) and with clinicaly advanced CRC. Patients treated because of perforation had a five-fold higher 30 day mortality rate (9.09% vs. 1.83%), however long-term survival did not differ significantly in both groups. After resectional surgery in 874 patients an intestinal anastomosis was made. Anastomotic leakage was present in 23 (2.6%) patients. This complication occurred six-fold more frequently in a group of patients operated upon because of intestinal perforation (12.20% vs. 2.16%). In patients with CRC complicated with perforation of the colon in a 30-day observation significantly higher rate of complications and mortality was shown, whereas there was no difference in distant survival rates.

Experimental and Theoretical Analysis of Sound Absorption Properties of Finely Perforated Wooden Panels

PubMed Central

Song, Boqi; Peng, Limin; Fu, Feng; Liu, Meihong; Zhang, Houjiang

2016-01-01

Perforated wooden panels are typically utilized as a resonant sound absorbing material in indoor noise control. In this paper, the absorption properties of wooden panels perforated with tiny holes of 1–3 mm diameter were studied both experimentally and theoretically. The Maa-MPP (micro perforated panels) model and the Maa-Flex model were applied to predict the absorption regularities of finely perforated wooden panels. A relative impedance comparison and full-factorial experiments were carried out to verify the feasibility of the theoretical models. The results showed that the Maa-Flex model obtained good agreement with measured results. Control experiments and measurements of dynamic mechanical properties were carried out to investigate the influence of the wood characteristics. In this study, absorption properties were enhanced by sound-induced vibration. The relationship between the dynamic mechanical properties and the panel mass-spring vibration absorption was revealed. While the absorption effects of wood porous structure were not found, they were demonstrated theoretically by using acoustic wave propagation in a simplified circular pipe with a suddenly changed cross-section model. This work provides experimental and theoretical guidance for perforation parameter design. PMID:28774063

Coagulation syndrome: Delayed perforation after colorectal endoscopic treatments

PubMed Central

Hirasawa, Kingo; Sato, Chiko; Makazu, Makomo; Kaneko, Hiroaki; Kobayashi, Ryosuke; Kokawa, Atsushi; Maeda, Shin

2015-01-01

Various procedure-related adverse events related to colonoscopic treatment have been reported. Previous studies on the complications of colonoscopic treatment have focused primarily on perforation or bleeding. Coagulation syndrome (CS), which is synonymous with transmural burn syndrome following endoscopic treatment, is another typical adverse event. CS is the result of electrocoagulation injury to the bowel wall that induces a transmural burn and localized peritonitis resulting in serosal inflammation. CS occurs after polypectomy, endoscopic mucosal resection (EMR), and even endoscopic submucosal dissection (ESD). The occurrence of CS after polypectomy or EMR varies according previous reports; most report an occurrence rate around 1%. However, artificial ulcers after ESD are largely theoretical, and CS following ESD was reported in about 9% of cases, which is higher than that for CS after polypectomy or EMR. Most cases of post-polypectomy syndrome (PPS) have an excellent prognosis, and they are managed conservatively with medical therapy. PPS rarely develops into delayed perforation. Delayed perforation is a severe adverse event that often requires emergency surgery. Since few studies have reported on CS and delayed perforation associated with CS, we focused on CS after colonoscopic treatments in this review. Clinicians should consider delayed perforation in CS patients. PMID:26380051

Optimizing time management after perforation by colonoscopy results in better outcome for the patients.

PubMed

Rumstadt, Bernhard; Schilling, Dieter

2008-01-01

Perforation during colonoscopy is a rare but severe complication. The aim of this study was to assess the time management and laparoscopic therapy of this complication and to evaluate patient outcomes. A retrospective analysis was done on 15 patients operated for a perforation from colonoscopy between January 2000 and December 2006. Three perforations occurred during diagnostic and 12 perforations during interventional colonoscopy. Two perforations occurred as transmural thermal injury to the colon wall. Peritonitis was found in 4 cases and significantly correlated with the mean time between perforation and operation. Twelve perforations were oversewn laparoscopically and 3 perforations were oversewn by laparotomy. After laparoscopic treatment, hospital stay was significantly shorter than after laparotomy. One patient had a postoperative wound infection, mortality was 0%. Laparoscopic oversewing is a safe and effective method in the treatment of perforation from colonoscopy. Optimizing the time range between perforation and laparoscopic therapy results in a better outcome for the patients.

Characterization of dopamine D1 and D2 receptor-expressing neurons in the mouse hippocampus.

PubMed

Gangarossa, Giuseppe; Longueville, Sophie; De Bundel, Dimitri; Perroy, Julie; Hervé, Denis; Girault, Jean-Antoine; Valjent, Emmanuel

2012-12-01

The hippocampal formation is part of an anatomical system critically involved in learning and memory. Increasing evidence suggests that dopamine plays an important role in learning and memory as well as in several forms of synaptic plasticity. However, the precise identification of neuronal populations expressing D1 or D2 dopamine receptors within the hippocampus is still lacking. To clarify this issue, we used BAC transgenic mice expressing enhanced green fluorescent protein (EGFP) under the control of the promoter of dopamine D1 or D2 receptors. In Drd1a-EGFP mice, sparse GFP-expressing neurons were detected among glutamatergic projecting neurons of the granular layer of the dentate gyrus and GABAergic interneurons located in the hilus. A dense immunofluorescence was observed in the outer and medial part of the molecular layer of the dentate gyrus as well as in the inner part of the molecular layer of CA1 corresponding to the terminals of pyramidal neurons of the entorhinal cortex defining the perforant and the temporo-ammonic pathway respectively. Finally, scattered D1 receptor-expressing neurons were also identified as GABAergic interneurons in the CA3/CA1 fields of the hippocampus. In Drd2-EGFP transgenic mice, GFP was exclusively detected in the glutamatergic mossy cells located in the polymorphic layer of the dentate gyrus. This pattern was confirmed in Drd2-Cre mice crossed with NLS-LacZ-Tau(mGFP) :LoxP and RCE:LoxP reporter lines. Our results demonstrate that D1 and D2 receptor-expressing neurons are strictly segregated in the mouse hippocampus. By clarifying the identity of D1 and D2 receptor-expressing neurons in the hippocampus, this study establishes a basis for future investigations aiming at elucidating their roles in the hippocampal network. Copyright © 2012 Wiley Periodicals, Inc.

Rapid reversal of stress induced loss of synapses in CA3 of rat hippocampus following water maze training.

PubMed

Sandi, Carmen; Davies, Heather A; Cordero, M Isabel; Rodriguez, Jose J; Popov, Victor I; Stewart, Michael G

2003-06-01

The impact was examined of exposing rats to two life experiences of a very different nature (stress and learning) on synaptic structures in hippocampal area CA3. Rats were subjected to either (i) chronic restraint stress for 21 days, and/or (ii) spatial training in a Morris water maze. At the behavioural level, restraint stress induced an impairment of acquisition of the spatial response. Moreover, restraint stress and water maze training had contrasting impacts on CA3 synaptic morphometry. Chronic stress induced a loss of simple asymmetric synapses [those with an unperforated postsynaptic density (PSD)], whilst water maze learning reversed this effect, promoting a rapid recovery of stress-induced synaptic loss within 2-3 days following stress. In addition, in unstressed animals a correlation was found between learning efficiency and the density of synapses with an unperforated PSD: the better the performance in the water maze, the lower the synaptic density. Water maze training increased the number of perforated synapses (those with a segmented PSD) in CA3, both in stressed and, more notably, in unstressed rats. The distinct effects of stress and learning on CA3 synapses reported here provide a neuroanatomical basis for the reported divergent effects of these experiences on hippocampal synaptic activity, i.e. stress as a suppressor and learning as a promoter of synaptic plasticity.

Health outcomes in US children with abdominal pain at major emergency departments associated with race and socioeconomic status.

PubMed

Wang, Louise; Haberland, Corinna; Thurm, Cary; Bhattacharya, Jay; Park, K T

2015-01-01

Over 9.6 million ED visits occur annually for abdominal pain in the US, but little is known about the medical outcomes of these patients based on demographics. We aimed to identify disparities in outcomes among children presenting to the ED with abdominal pain linked to race and SES. Data from 4.2 million pediatric encounters of abdominal pain were analyzed from 43 tertiary US children's hospitals, including 2.0 million encounters in the emergency department during 2004-2011. Abdominal pain was categorized as functional or organic abdominal pain. Appendicitis (with and without perforation) was used as a surrogate for abdominal pain requiring emergent care. Multivariate analysis estimated likelihood of hospitalizations, radiologic imaging, ICU admissions, appendicitis, appendicitis with perforation, and time to surgery and hospital discharge. Black and low income children had increased odds of perforated appendicitis (aOR, 1.42, 95% CI, 1.32- 1.53; aOR, 1.20, 95% CI 1.14 - 1.25). Blacks had increased odds of an ICU admission (aOR, 1.92, 95% CI 1.53 - 2.42) and longer lengths of stay (aHR, 0.91, 95% CI 0.86 - 0.96) than Whites. Minorities and low income also had lower rates of imaging for their appendicitis, including CT scans. The combined effect of race and income on perforated appendicitis, hospitalization, and time to surgery was greater than either separately. Based on race and SES, disparity of health outcomes exists in the acute ED setting among children presenting with abdominal pain, with differences in appendicitis with perforation, length of stay, and time until surgery.

Atrial septal defect closure with the new Cardia Ultrasept II™ device with interposed Goretex patch: Mexican experience - has the perforation of Ivalon's membrane been solved?

PubMed

Mijangos-Vázquez, Roberto; García-Montes, Antonio J; Soto-López, Elena M; Guarner-Lans, Verónica; Zabal, Carlos

2018-05-01

The objective of this study was to demonstrate the safety and feasibility of using the new Cardia Ultrasept II™ device with interposed Goretex patch referring to the perforation of polyvinyl alcohol membrane. Great advances have been made in the development of devices for closure of atrial septal defect. The Cardia Ultrasept II™ with interposed Goretex patch is the modified last generation of Cardia devices, having the advantage of a super-low profile within the atria and an integral locking delivery-retrieval mechanism that ensures safe deployment. In addition, with the interposition of the Goretex, it has been possible to abolish perforation of Ivalon's membrane as a complication.Methods and resultsPatients with ostium secundum atrial septal defect with surrounding rims with a minimum length of 5 mm and who underwent atrial septal defect closure with the new Ultrasept II™ with Goretex patch were included from two paediatric cardiac centres. Primary end point was to determine perforation of the Goretex membrane at follow-up; secondary end point included right ventricular diastolic diameter. In total, 30 patients underwent atrial septal defect closure at a median age of 6 (1-29) years. At follow-up for 6 (range, 1-15) months, freedom from perforations was 100%. A continuous decrease in right ventricular diastolic diameter was found with an initial median of 30 (25-49) mm and after catheterisation of 27.5 (18-33) mm, p=0.01, and Z-score of 2.6 (1.7-3.6) versus 1.9 (1-2.9) after procedure, p=0.01. The new modified generation of the Ultrasept II™ device with interposed Goretex patch is a good alternative to achieve atrial septal defect closure safely and feasibly with no membrane perforation at follow-up.

Clinical profile and outcome of surgical treatment of perforated peptic ulcers in Northwestern Tanzania: A tertiary hospital experience.

PubMed

Chalya, Phillipo L; Mabula, Joseph B; Koy, Mheta; Mchembe, Mabula D; Jaka, Hyasinta M; Kabangila, Rodrick; Chandika, Alphonce B; Gilyoma, Japhet M

2011-08-26

Perforated peptic ulcer is a serious complication of peptic ulcers with potential risk of grave complications. There is paucity of published reports on perforated peptic ulcer disease in our local environment. This study was conducted to evaluate the clinical presentation, management and outcome of patients with peptic ulcer perforation in our setting and to identify predictors of outcome of these patients. This was a combined retrospective and prospective study of patients who were operated for perforated peptic ulcers at Bugando Medical Centre between April 2006 and March 2011. Data were collected using a pre-tested and coded questionnaire and analyzed using SPSS computer software version 15.0. Ethical approval to conduct the study was obtained from relevant authority before the commencement of the study. A total of 84 patients were studied. Males outnumbered females by a ratio of 1.3: 1. Their median age was 28 years and the modal age group was 21-30 years. The median duration of illness was 5.8 days. The majority of patients (69.0%) had no previous history of treatment for peptic ulcer disease. The use of non-steroidal anti-inflammatory drugs, alcohol and smoking was reported in 10.7%, 85.7% and 64.3% respectively. Eight (9.5%) patients were HIV positive with a median CD4 count of 220 cells/μl. Most perforations were located on the duodenum {90.4%) with the duodenal to gastric ulcers ratio of 12.7: 1. Graham's omental patch (Graham's omentopexy) of the perforations was performed in 83.3% of cases. Complication and mortality rates were 29.8% and 10.7% respectively. The factors significantly related to complications were premorbid illness, HIV status, CD 4 count < 200 cells/μl, treatment delay and acute perforation (P < 0.001). Mortality rate was high in patients who had age ≥ 40 years, delayed presentation (>24 hrs), shock at admission (systolic BP < 90 mmHg), HIV positivity, low CD4 count (<200 cells/μl), gastric ulcers, concomitant diseases and presence of complications (P < 0.001). The median overall length of hospital stay was 14 days. Excellent results using Visick's grading system were obtained in 82.6% of surviving patients. Perforation of peptic ulcer remains a frequent clinical problem in our environment predominantly affecting young males not known to suffer from PUD. Simple closure with omental patch followed by Helicobacter pylori eradication was effective with excellent results in majority of survivors despite patients' late presentation in our center.

Clinical profile and outcome of surgical treatment of perforated peptic ulcers in Northwestern Tanzania: A tertiary hospital experience

PubMed Central

2011-01-01

Background Perforated peptic ulcer is a serious complication of peptic ulcers with potential risk of grave complications. There is paucity of published reports on perforated peptic ulcer disease in our local environment. This study was conducted to evaluate the clinical presentation, management and outcome of patients with peptic ulcer perforation in our setting and to identify predictors of outcome of these patients. Methods This was a combined retrospective and prospective study of patients who were operated for perforated peptic ulcers at Bugando Medical Centre between April 2006 and March 2011. Data were collected using a pre-tested and coded questionnaire and analyzed using SPSS computer software version 15.0. Ethical approval to conduct the study was obtained from relevant authority before the commencement of the study. Results A total of 84 patients were studied. Males outnumbered females by a ratio of 1.3: 1. Their median age was 28 years and the modal age group was 21-30 years. The median duration of illness was 5.8 days. The majority of patients (69.0%) had no previous history of treatment for peptic ulcer disease. The use of non-steroidal anti-inflammatory drugs, alcohol and smoking was reported in 10.7%, 85.7% and 64.3% respectively. Eight (9.5%) patients were HIV positive with a median CD4 count of 220 cells/μl. Most perforations were located on the duodenum {90.4%) with the duodenal to gastric ulcers ratio of 12.7: 1. Graham's omental patch (Graham's omentopexy) of the perforations was performed in 83.3% of cases. Complication and mortality rates were 29.8% and 10.7% respectively. The factors significantly related to complications were premorbid illness, HIV status, CD 4 count < 200 cells/μl, treatment delay and acute perforation (P < 0.001). Mortality rate was high in patients who had age ≥ 40 years, delayed presentation (>24 hrs), shock at admission (systolic BP < 90 mmHg), HIV positivity, low CD4 count (<200 cells/μl), gastric ulcers, concomitant diseases and presence of complications (P < 0.001). The median overall length of hospital stay was 14 days. Excellent results using Visick's grading system were obtained in 82.6% of surviving patients. Conclusion Perforation of peptic ulcer remains a frequent clinical problem in our environment predominantly affecting young males not known to suffer from PUD. Simple closure with omental patch followed by Helicobacter pylori eradication was effective with excellent results in majority of survivors despite patients' late presentation in our center. PMID:21871104

Application of Posterior Thigh Three-Dimensional Profunda Artery Perforator Perforasomes in Refining Next-Generation Flap Designs: Transverse, Vertical, and S-Shaped Profunda Artery Perforator Flaps.

PubMed

Mohan, Anita T; Zhu, Lin; Sur, Yoo Joon; Morsy, Mohamed; Michalak, Gregory J; Lachman, Nirusha; Rammos, Charalambos K; Saint-Cyr, Michel

2017-04-01

This study aimed to delineate and compare the hot spots and three-dimensional vascular territories of dominant profunda artery perforators in the posterior thigh region, and modifications in flap design are discussed. Twenty-nine posterior thigh flaps were raised in fresh cadaveric specimens, and profunda artery perforators were documented. Dominant perforators were injected with iodinated contrast to assess perforasomes using computed tomographic angiography. Analysis with three-dimensional rendering and volume calculations of perfusion patterns was performed. In total, 316 perforators were mapped and 33 perforators were injected for analysis. The hot spot for dominant perforators was the proximal medial quadrant, 5 to 10 cm from the inferior gluteal crease, with two smaller hot spots in the upper lateral and distal posterior midline. Although 69 percent were musculocutaneous, distal perforators were predominantly septocutaneous in the posterior midline, 5 to 8 cm from the popliteal crease. Proximal perforators were classified into first (most proximal) and second perforators, and their median perforasome was 233 and 286.4 cm, respectively (p = 0.86). There were no significant differences between proximal and distal perforators in perforasome surface areas, percentage areas perfused, and perforasome volumes. Large linking vessel networks were attributed to a broader perforasome and greater overlap between adjacent or distal perforators. Dominant linking vessels and recurrent flow through the subdermal plexus contribute to the robust vascular supply of profunda artery perforator flaps. Posterior thigh region perforator hot spots and their perfusion characteristics can inform the potential limits, orientation, and modifications of flap or skin paddle designs.

Bilobed perforator free flaps for combined hemitongue and floor-of-the-mouth defects.

PubMed

Longo, B; Ferri, G; Fiorillo, A; Rubino, C; Santanelli, F

2013-11-01

Combined hemiglossectomy and floor-of-the-mouth defects need accurate reconstructive planning to restore swallowing and speech function. The aim of this prospective study was to evaluate outcomes of the bilobed design applied to perforator free flaps for combined hemitongue and floor-of-the-mouth defects. Twelve patients with a mean age of 71 years (range, 60-84) addressed to combined hemiglossectomy and floor-of-the-mouth resection and bilobed-shaped perforator free-flap reconstruction were prospectively enrolled. Defects were classified as follows: type 1, including only the anterior mobile portion of the tongue (n = 3); type 2, involving both mobile tongue and tongue base (n = 6); and type 3, including segmental mandibulectomy combined with a type 1 or type 2 defect (n = 3). The Kruskal-Wallis and Bonferroni post hoc tests were used to compare outcomes. Type 1 defects were reconstructed by three anterolateral thigh (ALT) perforator flaps; type 2 defects were reconstructed by four ALT flaps and two vertical deep inferior epigastric perforator flaps; and type 3 defects were restored by three osteocutaneous fibula flaps. Eleven flaps (91.6%) healed uneventfully, while one (8.4%) suffered a small area of skin necrosis whose revision did not compromise functional results. Six patients achieved normal intelligible speech, five had acceptable intelligible speech and one had unintelligible speech (p = 0.356). Swallowing function was considered normal in eight patients and with mild impairment in four (p = 0.178). Cosmesis resulted excellent in seven patients and good in five (p = 0.855). The bilobed-shaped perforator free flaps were shown to be a safe and predictable solution for combined hemitongue and floor-of-the-mouth defects providing optimal aesthetic and functional outcomes. Copyright © 2013 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

Intraoperative use of indocyanine green angiography for selecting the more reliable perforator of the anterolateral thigh flap: A comparison study.

PubMed

La Padula, Simone; Hersant, Barbara; Meningaud, Jean Paul

2018-03-30

Anatomical variability of anterolateral thigh flap (ALT) perforators has been reported. The aim of this study is to assess if the use of intraoperative indocyanine green angiography (iICGA) can help surgeons to choose the ALT flap best perforator to be preserved. A retrospective study was conducted in 28 patients with open tibial fracture, following a road traffic crash, who had undergone ALT flap. Patients were classified into two groups: ICGA group (iICGA was used to select the more reliable perforator) and control group. The mean tissue loss size of the ICGA group (n = 13, 11 men and 2 women, mean age: 52 ± 6 years) was of 16.6 cm × 12.2 cm. The mean defect size of the control group (n = 15, 14 men and 1 women, mean age: 50 ± 5.52 years) was of 15.3 cm × 11.1 cm. Statistical analysis was performed to analyze and compare the results. ICGA allowed preserving only the most functional perforator, that provided the best ALT flap perfusion in 10 out of the 13 cases (77%). ICGA allowed a significant operative time reduction (160 ± 23 vs. 202 ± 48 minutes; P < .001). One case of distal necrosis was observed in the ICGA group (mean follow-up 12.3 months), while partial skin necrosis occurred in three cases of the control group (mean follow-up 13.1 months); P = .35. No additional coverage was required and a successful bone healing was observed in both groups. These findings suggest that iICGA is an effective method that allows to select the most reliable ALT flap perforators and to reduce operative time. © 2018 Wiley Periodicals, Inc.

Photoelastic investigations of stress concentration in perforated cylindrical shells with internal pressure

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dranchenko, B.N.; Portnov, B.B.; Seleznev, A.V.

1994-06-01

Cylindrical shells with regular perforation are widely used in power generating equipment and in particular in collectors 1 of the circuit of steam generators of power generating installations with water-water reactors (WWPR) The state of stress of collectors is determined by a broad spectrum of technological and operational loads, it is therefore difficult to analyze it theoretically. The aim of the present work is the experimental investigation of stresses in the cylindrical shells of collectors subjected to internal pressure, the generalization and systematization of empirical data in the form of engineering formulas and nomographs. The investigations were carried out withmore » photoelastic three-dimensional models with the use of {open_quotes}freezing{close_quotes}. The basic characteristics of the state of stress of perforated shells (in particular those used in calculations of the strength and life of collectors) are the values of the stress intensity factor K and of the stress intensification factor {gamma}{sub {bar {sigma}}}{sub me} of the mean integral stress level in the neck between neighboring holes. The presented data make it possible to establish quantitatively the regularities of change of K and {gamma}{sub {bar {sigma}}}{sub me} in dependence on the geometry of the perforated shells. These data were systematized according to a special program of multifactor regression analysis. It follows from the presented formulas and nomographs in particular that in the ranges of the geometry of the perforated shells K may change from 2.5 to 4.0, and {gamma}{sub {bar {sigma}}}{sub me} from 1.1 to 2.3. Therefore varied geometric parameters have a substantial effect on the load intensity of perforated shells, and that once again confirms how topical it is to obtain new experimental data, to generalize and systematize them.« less

The importance of immunohistochemical analyses in evaluating the phenotype of Kv channel knockout mice.

PubMed

Menegola, Milena; Clark, Eliana; Trimmer, James S

2012-06-01

To gain insights into the phenotype of voltage-gated potassium (Kv)1.1 and Kv4.2 knockout mice, we used immunohistochemistry to analyze the expression of component principal or α subunits and auxiliary subunits of neuronal Kv channels in knockout mouse brains. Genetic ablation of the Kv1.1 α subunit did not result in compensatory changes in the expression levels or subcellular distribution of related ion channel subunits in hippocampal medial perforant path and mossy fiber nerve terminals, where high levels of Kv1.1 are normally expressed. Genetic ablation of the Kv4.2 α subunit did not result in altered neuronal cytoarchitecture of the hippocampus. Although Kv4.2 knockout mice did not exhibit compensatory changes in the expression levels or subcellular distribution of the related Kv4.3 α subunit, we found dramatic decreases in the cellular and subcellular expression of specific Kv channel interacting proteins (KChIPs) that reflected their degree of association and colocalization with Kv4.2 in wild-type mouse and rat brains. These studies highlight the insights that can be gained by performing detailed immunohistochemical analyses of Kv channel knockout mouse brains. Wiley Periodicals, Inc. © 2012 International League Against Epilepsy.

Perforated peptic ulcer and short-term mortality among tramadol users.

PubMed

Tørring, Marie L; Riis, Anders; Christensen, Steffen; Thomsen, Reimar W; Jepsen, Peter; Søndergaard, Jens; Sørensen, Henrik T

2008-04-01

* Use of nonsteroidal anti-inflammatory drugs (NSAIDs) is a strong risk and prognostic factor for peptic ulcer perforation, and alternative analgesics are needed for high-risk patients. * Pain management guidelines propose tramadol as a treatment option for mild-to-moderate pain in patients at high risk of gastrointestinal side-effects, including peptic ulcer disease. * Tramadol may mask symptoms of peptic ulcer complications, yet tramadol's effect on peptic ulcer prognosis is unknown. * In this population-based study of 1271 patients hospitalized with peptic ulcer perforation, tramadol appeared to increase mortality at least as much as NSAIDs. * Among users of tramadol, alone or in combination with NSAIDs, adjusted 30-day mortality rate ratios were 2.02 [95% confidence interval (CI) 1.17, 3.48] and 1.32 (95% CI 0.89, 1.95), compared with patients who used neither tramadol nor NSAIDs. Use of nonsteroidal anti-inflammatory drugs (NSAIDs) increases risk and worsens prognosis for patients with complicated peptic ulcer disease. Therefore, patients who are at high risk of peptic ulcer often use tramadol instead of NSAIDs. Tramadol's effect on peptic ulcer prognosis is unknown. The aim was to examine mortality in the 30 days following hospitalization for perforated peptic ulcer among tramadol and NSAID users compared with non-users. The study was based on data on reimbursed prescriptions and hospital discharge diagnoses for the 1993-2004 period, extracted from population-based healthcare databases. All patients with a first-time diagnosis of perforated peptic ulcer were identified, excluding those with previous ulcer diagnoses or antiulcer drug use. Cox regression was used to estimate 30-day mortality rate ratios for tramadol and NSAID users compared with non-users, adjusting for use of other drugs and comorbidity. Of 1271 patients with perforated peptic ulcers included in the study, 2.4% used tramadol only, 38.9% used NSAIDs and 7.9% used both. Thirty-day mortality was 28.7% overall and 48.4% among users of tramadol alone. Compared with the 645 patients who used neither tramadol nor NSAIDs, the adjusted mortality rate in the 30 days following hospitalization was 2.02-fold [95% confidence interval (CI) 1.17, 3.48] higher for the 31 'tramadol only' users, 1.41-fold (95% CI 1.12, 1.78) higher for the 495 NSAID users and 1.32-fold (95% CI 0.89, 1.95) higher for the 100 patients who used both drugs. Among patients hospitalized for perforated peptic ulcer, tramadol appears to increase mortality at a level comparable to NSAIDs.

Policy Inputs to Honduran Government, Indigenous Federations, and NGOs

DTIC Science & Technology

2016-03-09

Meeting, June 8, 2015: met with representatives of Honduran Land Management Program (PATH II), indigenous Miskitu leaders from MASTA, and...Granados of Honduran Land Management Program (PATH II), Norvin Goff (President of MASTA indigenous federation), and Darío Cruz (Vice Rector at UPNFM). ...Government, Indigenous Federations, and NGOs Our cartographic research results on the CA Indígena website are used by Honduran government agencies

Investigation on the Acoustic Absorption of Flexible Micro-Perforated Panel with Ultra-Micro Perforations

NASA Astrophysics Data System (ADS)

Li, Guoxin; Tang, Xiaoning; Zhang, Xiaoxiao; Qian, Y. J.; Kong, Deyi

2017-11-01

Flexible micro-perforated panel has unique advantages in noise reduction due to its good flexibility compared with traditional rigid micro-perforated panel. In this paper, flexible micro-perforated panel was prepared by computer numerical control (CNC) milling machine. Three kinds of plastics including polyvinylchloride (PVC), polyethylene terephthalate (PET), and polyimide (PI) were taken as the matrix materials to prepare flexible micro-perforated panel. It has been found that flexible micro-perforated panel made of PET possessing good porosity and proper density, elastic modulus and poisson ratio exhibited the best acoustic absorption properties. The effects of various structural parameters including perforation diameter, perforation ratio, thickness and air gap have also been investigated, which would be helpful to the optimization of acoustic absorption properties.

The three-dimensional simulation analysis of dynamic response on perforated strings

NASA Astrophysics Data System (ADS)

Li, M. F.; Liu, H. F.; Dou, Y. H.; Cao, L. H.; Liu, Y. X.

2018-06-01

It analyzes the dynamic response and stresses of perforating tubular string to detonating impact load in oil-gas well in ANSYS, obtains the response of vibration displacement, velocity and acceleration of perforating tubularstring caused by detonating impact load, finds the influence of the length and wall thickness of perforating tubular string to working stresses. The result shows that:when the detonating impact load exerts the perforating tubular string with compressive and tensile axial force alternatively;the vibration displacement, velocity and acceleration of perfora-ting tubular string change periodically at same cycle;the closer to the perforating gun, the larger the amplitude of vi-bration velocity and acceleration;the closer to the packer the smaller the vibration displacement, the larger the work-ing equivalent stress of perforating tubular string;the longer or the thicker the perforating tubular string, the smaller the working equivalent stress and the higher the strength safety. Therefore, it uses the damping tube between packer and perforating gun as well as thick walled tubing to increase the strength safety of perforating tubular string.

Research on the Perforating Algorithm Based on STL Files

NASA Astrophysics Data System (ADS)

Yuchuan, Han; Xianfeng, Zhu; Yunrui, Bai; Zhiwen, Wu

2018-04-01

In the process of making medical personalized external fixation brace, the 3D data file should be perforated to increase the air permeability and reduce the weight. In this paper, a perforating algorithm for 3D STL file is proposed, which can perforate holes, hollow characters and engrave decorative patterns on STL files. The perforating process is composed of three steps. Firstly, make the imaginary space surface intersect with the STL model, and reconstruct triangles at the intersection. Secondly, delete the triangular facets inside the space surface and make a hole on the STL model. Thirdly, triangulate the inner surface of the hole, and thus realize the perforating. Choose the simple space equations such as cylindrical and rectangular prism equations as perforating equations can perforate round holes and rectangular holes. Through the combination of different holes, lettering, perforating decorative patterns and other perforated results can be accomplished. At last, an external fixation brace and an individual pen container were perforated holes using the algorithm, and the expected results were reached, which proved the algorithm is feasible.

Thulium fiber laser damage to the ureter

NASA Astrophysics Data System (ADS)

Wilson, Christopher R.; Hardy, Luke A.; Irby, Pierce B.; Fried, Nathaniel M.

2015-07-01

Our laboratory is studying experimental thulium fiber laser (TFL) as a potential alternative lithotripter to the clinical gold standard Holmium:YAG laser. Safety studies characterizing undesirable Holmium laser-induced damage to ureter tissue have been previously reported. Similarly, this study characterizes TFL induced ureter and stone basket damage. A TFL beam with pulse energy of 35 mJ, pulse duration of 500 μs, and pulse rates of 150-500 Hz was delivered through a 100-μm-core, low-OH, silica optical fiber to the porcine ureter wall, in vitro. Ureter perforation times were measured and gross, histological, and optical coherence tomography images of the ablation zone were acquired. TFL operation at 150, 300, and 500 Hz produced mean ureter perforation times of 7.9, 3.8, and 1.8 s, respectively. Collateral damage averaged 510, 370, and 310 μm. TFL mean perforation time exceeded 1 s at each setting, which is a greater safety margin than previously reported during Holmium laser ureter perforation studies.

Hepatobiliary and gallium imaging findings in gallbladder perforation: A case report and review of the literature

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yeo, E.; Chen, D.C.; Siegel, M.E.

1989-02-01

Gallbladder perforation is an unusual condition with a high mortality rate. Early detection with prompt surgical intervention can increase the survival rate. Hepatobiliary imaging using Technetium-99m-labeled iminodiacetic acid has been used for the diagnosis of gallbladder perforation. However, the results vary and are somewhat confusing. The authors report a case of gallbladder perforation with hepatobiliary imaging and an unusual gallium image; review the literature; and propose a classification of three different imaging patterns: (1) visualization of the gallbladder with bile leakage, (2) nonvisualization of the gallbladder with a photopenic fluid collection, and (3) nonvisualization of the gallbladder with bile leakage.more » These patterns may provide pathophysiologic information for the surgeon. 27 references.« less

A Precision Medicine Approach to the Rescue of Function on Malignant Calmodulinopathic Long-QT Syndrome.

PubMed

Limpitikul, Worawan B; Dick, Ivy E; Tester, David J; Boczek, Nicole J; Limphong, Pattraranee; Yang, Wanjun; Choi, Myoung Hyun; Babich, Jennifer; DiSilvestre, Deborah; Kanter, Ronald J; Tomaselli, Gordon F; Ackerman, Michael J; Yue, David T

2017-01-06

Calmodulinopathies comprise a new category of potentially life-threatening genetic arrhythmia syndromes capable of producing severe long-QT syndrome (LQTS) with mutations involving CALM1, CALM2, or CALM3. The underlying basis of this form of LQTS is a disruption of Ca 2+ /calmodulin (CaM)-dependent inactivation of L-type Ca 2+ channels. To gain insight into the mechanistic underpinnings of calmodulinopathies and devise new therapeutic strategies for the treatment of this form of LQTS. We generated and characterized the functional properties of induced pluripotent stem cell-derived cardiomyocytes from a patient with D130G-CALM2-mediated LQTS, thus creating a platform with which to devise and test novel therapeutic strategies. The patient-derived induced pluripotent stem cell-derived cardiomyocytes display (1) significantly prolonged action potentials, (2) disrupted Ca 2+ cycling properties, and (3) diminished Ca 2+ /CaM-dependent inactivation of L-type Ca 2+ channels. Next, taking advantage of the fact that calmodulinopathy patients harbor a mutation in only 1 of 6 redundant CaM-encoding alleles, we devised a strategy using CRISPR interference to selectively suppress the mutant gene while sparing the wild-type counterparts. Indeed, suppression of CALM2 expression produced a functional rescue in induced pluripotent stem cell-derived cardiomyocytes with D130G-CALM2, as shown by the normalization of action potential duration and Ca 2+ /CaM-dependent inactivation after treatment. Moreover, CRISPR interference can be designed to achieve selective knockdown of any of the 3 CALM genes, making it a generalizable therapeutic strategy for any calmodulinopathy. Overall, this therapeutic strategy holds great promise for calmodulinopathy patients as it represents a generalizable intervention capable of specifically altering CaM expression and potentially attenuating LQTS-triggered cardiac events, thus initiating a path toward precision medicine. © 2016 American Heart Association, Inc.

The role of calcium in the desensitization of capsaicin responses in rat dorsal root ganglion neurons.

PubMed

Koplas, P A; Rosenberg, R L; Oxford, G S

1997-05-15

Capsaicin (Cap) is a pungent extract of the Capsicum pepper family, which activates nociceptive primary sensory neurons. Inward current and membrane potential responses of cultured neonatal rat dorsal root ganglion neurons to capsaicin were examined using whole-cell and perforated patch recording methods. The responses exhibited strong desensitization operationally classified as acute (diminished response during constant Cap exposure) and tachyphylaxis (diminished response to successive applications of Cap). Both acute desensitization and tachyphylaxis were greatly diminished by reductions in external Ca2+ concentration. Furthermore, chelation of intracellular Ca2+ by addition of either EGTA or bis(2-aminophenoxy)ethane-N,N,N',N'-tetra-acetic acid to the patch pipette attenuated both forms of desensitization even in normal Ca2+. Release of intracellular Ca2+ by caffeine triggered acute desensitization in the absence of extracellular Ca2+, and barium was found to effectively substitute for calcium in supporting desensitization. Cap activated inward current at an ED50 of 728 nM, exhibiting cooperativity (Hill coefficient, 2.2); however, both forms of desensitization were only weakly dependent on [Cap], suggesting a dissociation between activation of Cap-sensitive channels and desensitization. Removal of ATP and GTP from the intracellular solutions resulted in nearly complete tachyphylaxis even with intracellular Ca2+ buffered to low levels, whereas changes in nucleotide levels did not significantly alter the acute form of desensitization. These data suggest a key role for intracellular Ca2+ in desensitization of Cap responses, perhaps through Ca2+-dependent dephosphorylation at a locus that normally sustains Cap responsiveness via ATP-dependent phosphorylation. It also seems that the signaling mechanisms underlying the two forms of desensitization are not identical in detail.

Role of ion channels and subcellular Ca2+ signaling in arachidonic acid-induced dilation of pressurized retinal arterioles.

PubMed

Kur, Joanna; McGahon, Mary K; Fernández, Jose A; Scholfield, C Norman; McGeown, J Graham; Curtis, Tim M

2014-05-02

To investigate the mechanisms responsible for the dilatation of rat retinal arterioles in response to arachidonic acid (AA). Changes in the diameter of isolated, pressurized rat retinal arterioles were measured in the presence of AA alone and following pre-incubation with pharmacologic agents inhibiting Ca(2+) sparks and oscillations and K(+) channels. Subcellular Ca(2+) signals were recorded in arteriolar myocytes using Fluo-4-based confocal imaging. The effects of AA on membrane currents of retinal arteriolar myocytes were studied using whole-cell perforated patch clamp recording. Arachidonic acid dilated pressurized retinal arterioles under conditions of myogenic tone. Eicosatetraynoic acid (ETYA) exerted a similar effect, but unlike AA, its effects were rapidly reversible. Arachidonic acid-induced dilation was associated with an inhibition of subcellular Ca(2+) signals. Interventions known to block Ca(2+) sparks and oscillations in retinal arterioles caused dilatation and inhibited AA-induced vasodilator responses. Arachidonic acid accelerated the rate of inactivation of the A-type Kv current and the voltage dependence of inactivation was shifted to more negative membrane potentials. It also enhanced voltage-activated and spontaneous large-conductance calcium-activated K(+) (BK) currents, but only at positive membrane potentials. Pharmacologic inhibition of A-type Kv and BK currents failed to block AA-induced vasodilator responses. Arachidonic acid suppressed L-type Ca(2+) currents. These results suggest that AA induces retinal arteriolar vasodilation by inhibiting subcellular Ca(2+)-signaling activity in retinal arteriolar myocytes, most likely through a mechanism involving the inhibition of L-type Ca(2+)-channel activity. Arachidonic acid actions on K(+) currents are inconsistent with a model in which K(+) channels contribute to the vasodilator effects of AA.

Mechanisms of the palmitoylcarnitine-induced response in vascular endothelial cells.

PubMed

Taki, H; Muraki, K; Imaizumi, Y; Watanabe, M

1999-09-01

The mechanisms of Ca2+ mobilization induced by palmitoylcarnitine (Palcar) in rabbit aortic endothelial cells (ETCs) were examined using electrophysiological techniques. The results obtained were compared with those induced by acetylcholine (ACh). When a rabbit aortic muscle preparation with an intact endothelium was treated with 10 microM Palcar, the ACh-induced relaxation was markedly attenuated, whereas endothelium-independent relaxation caused by sodium nitroprusside was not affected. Under perforated-patch whole-cell-clamp conditions, the application of Palcar over the concentration range 0.3 and 10 microM elicited a slowly activating outward current (IPalcar-out), whereas ACh induced a rapidly activating outward current (IACh). A potassium channel blocker, 4-aminopyridine, significantly inhibited both IPalcar-out and IACh. Removal of external Ca2+ almost abolished IPalcar-out. Under the same conditions, however, IACh remained transient. Addition of cation channel blockers SK&F96365 and La3+ inhibited IPalcar-out more effectively than IACh. Application of staurosporine, an inhibitor of protein kinase C, affected neither IACh nor IPalcar-out. In contrast, treatment of ETCs with pertussis toxin (PTX) reduced IACh and almost abolished IPalcar-out. These findings demonstrate that, in ETCs, Palcar induces Ca2+ influx via the activation of PTX-sensitive GTP-binding protein, leading to the activation of Ca(2+)-dependent K+ current and hyperpolarization of the cell.

Augmented PMMA distribution: improvement of mechanical property and reduction of leakage rate of a fenestrated pedicle screw with diameter-tapered perforations.

PubMed

Tan, Quan-Chang; Wu, Jian-Wei; Peng, Fei; Zang, Yuan; Li, Yang; Zhao, Xiong; Lei, Wei; Wu, Zi-Xiang

2016-06-01

OBJECTIVE This study investigated the optimum injection volume of polymethylmethacrylate (PMMA) to augment a novel fenestrated pedicle screw (FPS) with diameter-tapered perforations in the osteoporotic vertebral body, and how the distribution characteristics of PMMA affect the biomechanical performance of this screw. METHODS Two types of FPSs were designed (FPS-A, composed of 6 perforations with an equal diameter of 1.2 mm; and FPS-B, composed of 6 perforations each with a tapered diameter of 1.5 mm, 1.2 mm, and 0.9 mm from tip to head. Each of 28 human cadaveric osteoporotic vertebrae were randomly assigned to 1 of 7 groups: FPS-A1.0: FPS-A+1.0 ml PMMA; FPS-A1.5: FPS-A+1.5 ml PMMA; FPS-A2.0: FPS-A+2.0 ml PMMA; FPS-B1.0: FPS-B+1.0 ml PMMA; FPS-B1.5: FPS-B+1.5 ml PMMA; FPS-B2.0: FPS-B+2.0 ml PMMA; and conventional pedicle screws (CPSs) without PMMA. After the augmentation, 3D CT was performed to assess the cement distribution characteristics and the cement leakage rate. Axial pullout tests were performed to compare the maximum pullout force thereafter. RESULTS The CT construction images showed that PMMA bone cement formed a conical mass around FPS-A and a cylindrical mass around FPS-B. When the injection volume was increased from 1.0 ml to 2.0 ml, the distribution region of the PMMA cement was enlarged, the PMMA was distributed more posteriorly, and the risk of leakage was increased. When the injection volume reached 2.0 ml, the risk of cement leakage was lower for screws having diameter-tapered perforations. The pullout strengths of the augmented FPS-A groups and FPS-B groups were higher than that of the CPS group (p < 0.0001). All FPS-B groups had a higher pullout strength than the FPS-A groups. CONCLUSIONS The diameter of the perforations affects the distribution of PMMA cement. The diameter-tapered design enabled PMMA to form larger bone-PMMA interfaces and achieve a relatively higher pullout strength, although statistical significance was not reached. Study results indicated 1.5-ml of PMMA was a conservative volume for PMMA augmentation; more cement injection would significantly increase the risk of cement leakage.

Experience with acute perforated duodenal ulcer in a West African population.

PubMed

Nuhu, A; Kassama, Y

2008-01-01

The advent of proton pump inhibitors and helicobacter pylori eradication in the management of chronic peptic ulcer disease has reduced the operative treatment of this condition to its complications. Perforated duodenal ulcer remains a major life threatening complication of chronic peptic ulcer disease. This retrospective study reviews our experience at the Royal Victoria Teaching Hospital. All patients with clinical diagnosis of perforated duodenal ulcer seen in this hospital between June 2003 and October 2005 were included in this study. Data extracted from their hospital records were analyzed for age, sex, duration of symptoms, previous history of peptic ulcer disease, use of NSAIDS, main presenting features, investigations, resuscitative measures, time of surgery, operative findings, and type of surgery offered, complications and mortality. After resuscitation, laparotomy followed by simple closure or definitive ulcer surgery and helicobacter pylori eradication therapy was given to all the patients. Duration of follow up ranged 8 to 12 months with endoscopy in some patients. There were 41 patients with intraoperative diagnosis of acute perforated duodenal ulcer seen over the study period, comprising 34 males (82.9%) and 7 females (17.1%), a male female ratio of 4.8:1, age range of 18-77 years and a mean age of 45.49 +/- 14.46 years. Previous history of peptic ulcer disease was found in 32 (78.6%) of the patient and the main presenting features were sudden onset of severe abdominal pain in 95.1% of cases and fever in 65.8%. Features of frank peritonitis were demonstrable in all the patients and 11 (26.8%) presented in shock. Plain chest x-rays demonstrated gas under the diaphragm in 21(65.6%) of the patients. After adequate resuscitation, all the patients underwent laparotomy where the abdomen was explored, the diagnosis of perforated duodenal ulcer was confirmed and 29 (70.7%) had simple closure of the perforation with omentum (after Graham). The average time between presentation and surgery was 9 hours (range 6-11 hours). The mean size of perforation was 10.5 mm (range 5-15 mm). Definitive peptic ulcer surgery was done in 12 (29.3%) patients. 8 had truncal vagotomy and pyloroplasty. The major complications included wound infection in 14 (34.1%), postoperative fever in 16 (39.0%) and prolonged ileus in 15 (36.6%) There were 7 deaths, mortality rate of 17.1% and the causes of death included severe electrolyte imbalance in 1 and gram negative septicaemia and shock in 6. The average duration of hospital stay was 10 days (range 8-36). Perforated duodenal ulcer is a major complication of chronic peptic ulcer disease. Simple omental patch by open method and helicobacter pylori eradication therapy is sufficient to prevent reperforation.

Pathophysiological Factors Associated with Left Ventricular Perforation in Transcatheter Aortic Valve Implantation by Transfemoral Approach.

PubMed

Owais, Tamer; El Garhy, Mohammad; Fuchs, Jürgen; Disha, Kushtrim; Elkaffas, Sameh; Breuer, Martin; Lauer, Bernward; Kuntze, Thomas

2017-07-01

Left ventricular (LV) perforation is one of the rare and most serious complications of transcatheter aortic valve implantation (TAVI). The study aim was to determine the pathophysiological factors associated with this serious complication. A retrospective study was conducted of pathophysiological factors shown in echocardiograms and computed tomography angiograms performed preoperatively in patients who developed LV perforation during transfemoral TAVI (study group) with regards to anatomic and functional variables. Results were then compared with data acquired from a randomly selected sample of patients without perforation (control group). Among 963 TAVI cases, LV perforation occurred in 11 patients (three males, eight females; mean age 79 years). These patients showed complications of LV perforation that required emergency sternotomy and repair of injury to the left ventricle. Ten patients were rescued by the procedure, but one patient died during surgery. Focus on preoperative factors and intraoperative steps was established in favor to identify possible predictors of LV perforation. A LV cavity size <4.2 cm and a hypercontractile ventricle were identified in 10 patients (90%). Only one patient had a dilated cardiomyopathic left ventricle, with a cavity size of 6.1 cm and an ejection fraction of 10%. The present study results revealed other specific patient-related factors, namely a narrow aorto-mitral angle and a thin ventricular muscular wall despite long-standing aortic stenosis. All 11 patients had an average mid-LV muscular wall thickness of 5 mm. An inverse proportional relationship between the aorto-mitral angle and the incidence of perforation was noted, where in all 11 patients the wire had directed itself towards the anterior free wall of the left ventricle, where it induced injury. A small LV cavity, a hypercontractile state, a thin muscular wall, and a narrow aorto-mitral angle may be considered potential predictors of the occurrence of LV perforation during TAVI.

A simple concept for covering pressure sores: wound edge-based propeller perforator flap.

PubMed

Kelahmetoglu, Osman; Van Landuyt, Koenraad; Yagmur, Caglayan; Sommeling, Casper E; Keles, Musa K; Tayfur, Volkan; Simsek, Tekin; Demirtas, Yener; Guneren, Ethem

2017-12-01

We present a new surgical modification to allow propeller perforator flaps to cover pressure sores at various locations. We used a propeller perforator flap concept based on the detection of newly formed perforator vessels located 1 cm from the wound margin and stimulated by the chronic inflammation process. Between January 2009 and January 2017, 33 wound edge-based propeller perforator flaps were used to cover pressure sores at various locations in 28 patients. In four cases more than one flap was used on the same patient. The patients comprised 18 males and 10 females with a mean age of 41·25 (range, 16-70) years. All patients underwent follow-up for 0-12 months. The mean follow-up duration was 5·03 months. Venous congestion was observed in three flaps that were rotated by 180° (9·1%). However, there was a significant difference between flaps rotated by 90° and 180° according to the complication rate (P = 0·034). Out of 33 flaps, 29 flaps healed uneventfully. Patients were able to sit and lie on their flaps three weeks after surgery. In our study, we were able to obtain satisfying final results using these novel flaps. © 2017 Medicalhelplines.com Inc and John Wiley & Sons Ltd.

A comparative study of the incidence of Schneiderian membrane perforations during maxillary sinus augmentation with a sonic oscillating handpiece versus a conventional turbine handpiece.

PubMed

Geminiani, Alessandro; Weitz, Daniel S; Ercoli, Carlo; Feng, Changyong; Caton, Jack G; Papadimitriou, Dimitrios E V

2015-04-01

Sonic instruments may reduce perforation rates of the schneiderian membrane during lateral window sinus augmentation procedures. This study compares the incidence of membrane perforations using a sonic handpiece with an oscillating diamond insert versus a turbine handpiece with a conventional rotary diamond stone during lateral window sinus augmentation procedures. A retrospective chart analysis identified all lateral window sinus augmentation procedures done during a defined period. Among these procedures, those performed with a sonic handpiece and an oscillating diamond insert (experimental) and those performed with a conventional turbine and rotary diamond stone (conventional) were selected for this study. Reported occurrences of sinus membrane perforations during preparation of the osteotomy and elevation of the sinus membrane, as well as postoperative complications, were recorded and compared between treatment groups. Ninety-three consecutive patients were identified for a total of 130 sinus augmentation procedures (51 conventional, 79 experimental). Schneiderian membrane perforations were noted during preparation of the lateral window osteotomy in 27.5% of the sinuses in the conventional group and 12.7% of sinuses in the experimental group. During membrane elevation, perforations were noted in 43.1% of the sinuses in the conventional group and 25.3% of sinuses in the experimental group. Both differences in perforation rates were statistically significant (p < .05). There was no statistically significant difference in postoperative complications. In this study, the use of a sonic instrument to prepare the lateral window osteotomy during sinus elevation procedures resulted in a reduced perforation rate of the Schneiderian membrane compared with the conventional turbine instrument. © 2013 Wiley Periodicals, Inc.

Quantitative analysis of tympanic membrane perforation: a simple and reliable method.

PubMed

Ibekwe, T S; Adeosun, A A; Nwaorgu, O G

2009-01-01

Accurate assessment of the features of tympanic membrane perforation, especially size, site, duration and aetiology, is important, as it enables optimum management. To describe a simple, cheap and effective method of quantitatively analysing tympanic membrane perforations. The system described comprises a video-otoscope (capable of generating still and video images of the tympanic membrane), adapted via a universal serial bus box to a computer screen, with images analysed using the Image J geometrical analysis software package. The reproducibility of results and their correlation with conventional otoscopic methods of estimation were tested statistically with the paired t-test and correlational tests, using the Statistical Package for the Social Sciences version 11 software. The following equation was generated: P/T x 100 per cent = percentage perforation, where P is the area (in pixels2) of the tympanic membrane perforation and T is the total area (in pixels2) for the entire tympanic membrane (including the perforation). Illustrations are shown. Comparison of blinded data on tympanic membrane perforation area obtained independently from assessments by two trained otologists, of comparative years of experience, using the video-otoscopy system described, showed similar findings, with strong correlations devoid of inter-observer error (p = 0.000, r = 1). Comparison with conventional otoscopic assessment also indicated significant correlation, comparing results for two trained otologists, but some inter-observer variation was present (p = 0.000, r = 0.896). Correlation between the two methods for each of the otologists was also highly significant (p = 0.000). A computer-adapted video-otoscope, with images analysed by Image J software, represents a cheap, reliable, technology-driven, clinical method of quantitative analysis of tympanic membrane perforations and injuries.

Locus Coeruleus Stimulation Facilitates Long-Term Depression in the Dentate Gyrus That Requires Activation of β-Adrenergic Receptors

PubMed Central

Hansen, Niels; Manahan-Vaughan, Denise

2015-01-01

Synaptic plasticity comprises a cellular mechanism through which the hippocampus most likely enables memory formation. Neuromodulation, related to arousal, is a key aspect in information storage. The activation of locus coeruleus (LC) neurons by novel experience leads to noradrenaline release in the hippocampus at the level of the dentate gyrus (DG). We explored whether synaptic plasticity in the DG is influenced by activation of the LC via electrical stimulation. Coupling of test-pulses that evoked stable basal synaptic transmission in the DG with stimulation of the LC induced β-adrenoreceptor-dependent long-term depression (LTD) at perforant path–DG synapses in adult rats. Furthermore, persistent LTD (>24 h) induced by perforant path stimulation also required activation of β-adrenergic receptors: Whereas a β-adrenergic receptor antagonist (propranolol) prevented, an agonist (isoproterenol) strengthened the persistence of LTD for over 24 h. These findings support the hypothesis that persistent LTD in the DG is modulated by β-adrenergic receptors. Furthermore, LC activation potently facilitates DG LTD. This suggests in turn that synaptic plasticity in the DG is tightly regulated by activity in the noradrenergic system. This may reflect the role of the LC in selecting salient information for subsequent synaptic processing in the hippocampus. PMID:24464942

Imidacloprid toxicity impairs spatial memory of echolocation bats through neural apoptosis in hippocampal CA1 and medial entorhinal cortex areas.

PubMed

Hsiao, Chun-Jen; Lin, Ching-Lung; Lin, Tian-Yu; Wang, Sheue-Er; Wu, Chung-Hsin

2016-04-13

It has been reported that the decimation of honey bees was because of pesticides of imidacloprid. The imidacloprid is a wildly used neonicotinoid insecticide. However, whether imidacloprid toxicity interferes with the spatial memory of echolocation bats is still unclear. Thus, we compared the spatial memory of Formosan leaf-nosed bats, Hipposideros terasensis, before and after chronic treatment with a low dose of imidacloprid. We observed that stereotyped flight patterns of echolocation bats that received chronic imidacloprid treatment were quite different from their originally learned paths. We further found that neural apoptosis in hippocampal CA1 and medial entorhinal cortex areas of echolocation bats that received imidacloprid treatment was significantly enhanced in comparison with echolocation bats that received sham treatment. Thus, we suggest that imidacloprid toxicity may interfere with the spatial memory of echolocation bats through neural apoptosis in hippocampal CA1 and medial entorhinal cortex areas. The results provide direct evidence that pesticide toxicity causes a spatial memory disorder in echolocation bats. This implies that agricultural pesticides may pose severe threats to the survival of echolocation bats.

The rate of glove perforations in orthopaedic procedures: single versus double gloving. A prospective study.

PubMed

Chan, K Y; Singh, V A; Oun, B H; To, B H Se

2006-12-01

Glove perforation during surgery has always been a matter of concern as it increases the infection rate and the risk of transmission of blood borne diseases. To determine the common causes, the site and the awareness of glove perforations in orthopaedic surgery, a prospective study was conducted to assess the rate of glove perforation during 130 consecutive orthopaedic operations. All gloves worn by the surgical team were assessed after the surgery using the water-loading test. A total of 1452 gloves were tested, and the rate of perforation was 3.58%. Most of these perforations (61.5%) were unnoticed. The main surgeons had the most perforations (76.9%), followed by first assistants (13.5%) and second assistants (9.6%). Most perforations occurred at the non-dominant hand. The commonest site of perforation was the index finger followed by the thumb. Shearing force with instruments accounted for 45% of the noticed perforations. Majority of these occurred during nailing procedures (33%) and internal fixation without the use of wires (19%). Our rate of glove perforation is similar to other series. Most of them went unnoticed and were mainly due to shearing injuries rather than perforation by sharps. Therefore, there is an increased risk of contamination and break in asepsis during surgery.

Perforator and secondary branch origin in relation to the neck of saccular, cerebral bifurcation aneurysms.

PubMed

Pritz, Michael B

2014-11-01

Perforator and secondary branch origin in relation to the neck of cerebral, saccular bifurcation aneurysms were analyzed. These two features were considered important for treatment. From a series of microsurgically clipped saccular cerebral aneurysms, 142 bifurcation aneurysms had detailed imaging studies and operative records that could be analyzed. The incidence of perforator origin from the aneurysm neck was as follows: basilar, 1/15 (7%); internal carotid artery bifurcation, 4/23 (17%); main stem of the middle cerebral artery/secondary branch of the middle cerebral artery, 6/52 (12%); anterior communicating artery region, 5/46 (11%); and distal bifurcation vessels, 0/6 (0%). Aneurysms arising from the anterior communicating artery between the anterior cerebral arteries had a high incidence of perforator origin from the aneurysm neck. The location of secondary branch origin from the aneurysm neck varied depending on the aneurysm group. Perforator origin from the aneurysm neck was infrequent. A subgroup of anterior communicating artery region aneurysms had a high incidence of perforator origin from the aneurysm neck. Although protection of these neck perforators will be difficult, their identification may be even more challenging. Secondary branch origin from the aneurysm neck varied depending on the aneurysm group. Advanced endovascular techniques are needed to obliterate aneurysms in which the secondary branch(es) arise from the aneurysm neck. If this is not possible, craniotomy and clip ligation will be required if complete aneurysm obliteration is the goal. Copyright © 2014 Elsevier Inc. All rights reserved.

Colorectal cancer with intestinal perforation – a retrospective analysis of treatment outcomes

PubMed Central

Woda, Łukasz; Tojek, Krzysztof; Jarmocik, Paweł; Jawień, Arkadiusz

2014-01-01

Aim of the study Colorectal cancer (CRC) is one of the leading cause of death in European population. It progresses without any symptoms in the early stages or those clinical symptoms are very discrete. The aim of this study was a retrospective analysis of treatment outcomes in patients with colorectal cancer complicated with intestinal perforation. Material and methods A retrospective analysis of patients urgently operated upon in our Division of General Surgery, because of large intestine perforation, from February 1993 to February 2013 has been made. Results were compared with a group of patients undergoing the elective surgery for colorectal cancer in the same time and Division. Results Intestinal perforation occurred more often in males (6.52% vs. 6.03%), patients with mucous component in histopathological examination (9.09% vs. 6.01%) and with clinicaly advanced CRC. Patients treated because of perforation had a five-fold higher 30 day mortality rate (9.09% vs. 1.83%), however long-term survival did not differ significantly in both groups. After resectional surgery in 874 patients an intestinal anastomosis was made. Anastomotic leakage was present in 23 (2.6%) patients. This complication occurred six-fold more frequently in a group of patients operated upon because of intestinal perforation (12.20% vs. 2.16%). Conclusions In patients with CRC complicated with perforation of the colon in a 30-day observation significantly higher rate of complications and mortality was shown, whereas there was no difference in distant survival rates. PMID:25784840

Safely combining abdominoplasty with aggressive abdominal liposuction based on perforator vessels: technique and a review of 300 consecutive cases.

PubMed

Smith, Lane F; Smith, Lane F

2015-05-01

There continues to be controversy about performing abdominoplasty concurrently with abdominal liposuction. The concern is that liposuction on the already vascularly compromised abdominal flap will lead to increased complications and flap necrosis. The central abdomen is supplied by the epigastric system. If perforator vessels from this system are spared, the blood supply to the abdomen can be spared and liposuction should be able to be safely performed on the elevated abdominal flap. The purpose of this study was to evaluate the safety of abdominoplasty with concurrent abdominal liposuction when a perforator vessel is spared. A standard abdominoplasty was performed, sparing one or two perforator vessels from the deep superior epigastric artery system. A retrospective chart review of 300 consecutive patients who underwent abdominoplasty surgery combined with concurrent abdominal liposuction was performed. Complications, total volume of abdominal liposuction, and results were reviewed. The overall complication rate was 17.3 percent (52 patients). Sixteen percent (48 patients) suffered minor complications and 1.3 percent (four patients) suffered major complications. Abdominoplasty can be combined safely with concurrent abdominal liposuction when a perforator vessel is spared. The combination of concurrent liposuction with abdominoplasty showed no increase in complication rates when a perforator vessel was spared. The perforator vessels are located consistently in a 2-cm radius located 4 cm from the midline and 6 cm from the subcostal margin. The potential advantages of abdominoplasty with concurrent liposuction include a better postoperative cosmetic result. Therapeutic, IV.

Study of multipactor suppression of microwave components using perforated waveguide technology for space applications

NASA Astrophysics Data System (ADS)

Ye, Ming; Li, Yun; He, Yongning; Daneshmand, Mojgan

2017-05-01

With the development of space technology, microwave components with increased power handling capability and reduced weight have been urgently required. In this work, the perforated waveguide technology is proposed to suppress the multipactor effect of high power microwave components. Meanwhile, this novel method has the advantage of reducing components' weight, which makes it to have great potential in space applications. The perforated part of the waveguide components can be seen as an electron absorber (namely, its total electron emission yield is zero) since most of the electrons impacting on this part will go out of the components. Based on thoroughly benchmarked numerical simulation procedures, we simulated an S band and an X band waveguide transformer to conceptually verify this idea. Both electron dynamic simulations and electrical loss simulations demonstrate that the perforation technology can improve the multipactor threshold at least ˜8 dB while maintaining the acceptable insertion loss level compared with its un-perforated components. We also found that the component with larger minimum gap is easier to achieve multipactor suppression. This effect is interpreted by a parallel plate waveguide model. What's more, to improve the multipactor threshold of the X band waveguide transformer with a minimum gap of ˜0.1 mm, we proposed a perforation structure with the slope edge and explained its mechanism. Future study will focus on further optimization of the perforation structure, size, and distribution to maximize the comprehensive performances of microwave components.

Risk factors associated with oroantral perforation during surgical removal of maxillary third molar teeth.

PubMed

Hasegawa, Takumi; Tachibana, Akira; Takeda, Daisuke; Iwata, Eiji; Arimoto, Satomi; Sakakibara, Akiko; Akashi, Masaya; Komori, Takahide

2016-12-01

The relationship between radiographic findings and the occurrence of oroantral perforation is controversial. Few studies have quantitatively analyzed the risk factors contributing to oroantral perforation, and no study has reported multivariate analysis of the relationship(s) between these various factors. This retrospective study aims to fill this void. Various risk factors for oroantral perforation during maxillary third molar extraction were investigated by univariate and multivariate analysis. The proximity of the roots to the maxillary sinus floor (root-sinus [RS] classification) was assessed using panoramic radiography and classified as types 1-5. The relationship between the maxillary second and third molars was classified according to a modified version of the Archer classification. The relative depth of the maxillary third molar in the bone was classified as class A-C, and its angulation relative to the long axis of the second molar was also recorded. Performance of an incision (OR 5.16), mesioangular tooth angulation (OR 6.05), and type 3 RS classification (i.e., significant superimposition of the roots of all posterior maxillary teeth with the sinus floor; OR 10.18) were all identified as risk factors with significant association to an outcome of oroantral perforation. To our knowledge, this is the first multivariate analysis of the risk factors for oroantral perforation during surgical extraction of the maxillary third molar. This RS classification may offer a new predictive parameter for estimating the risk of oroantral perforation.

Therapeutic management of perforated gastro-duodenal ulcer: literature review.

PubMed

Mouly, C; Chati, R; Scotté, M; Regimbeau, J-M

2013-11-01

Management of perforated gastro-duodenal ulcer (GDU) is not consensual, from no operative treatment to surgery by simple closure, gastrectomy and vagotomy. The purpose of this study is to report results of the literature concerning management of perforated GDU. Two authors, identified in the databases Pubmed and Embase studies, related to the therapeutic management of perforated GDU. The data were extracted from articles published between 1940 and 2012. Non-operative treatment is feasible for patients in good general condition and in good local circumstances without evolved peritonitis with a success rate more than 50%. Simple closure is the standard method. Laparoscopy is a safe and feasible method for patient with delay of treatment less than 24 hours and without associated complications with a success (meaning non conversion) of 80% and a mortality less than 1%. Rate of conversion is 7.9%, and increases in case of ulcer size >6 mm, frail ulcer edges, bleeding associated, unusual location and septic shock. Helicobacter pylori eradication is essential. Gastric tube, abdominal irrigation and drainage are still debated. Two-stage treatment for perforated gastric carcinoma, which represents 10 to 16% of gastric perforation, is a good option for frail patients with resectable tumors. Management of perforated GDU is still a subject of debate without guidelines but with several possibilities of treatment depending of local circumstances of peritonitis and size of defect >20 mm, general conditions, surgeon patterns and experience. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

Malignant lymphoma incidentally diagnosed due to the perforation of the small intestine caused by a fish bone: A case report.

PubMed

Hiraki, Masatsugu; Miyoshi, Atsushi; Anegawa, Go; Kubo, Hiroshi; Ikeda, Osamu; Ohira, Keiichi; Azama, Shinya; Kido, Shinichi; Mori, Daisuke; Aibe, Hitoshi; Tanaka, Toshiya; Kitahara, Kenji; Sato, Seiji

2017-01-01

The ingestion of a foreign body is relatively common. However, it rarely results in the perforation of gastrointestinal tract. We herein report an unusual case of malignant lymphoma incidentally diagnosed after the perforation of the small intestine by a fish bone. A 90-year-old woman was admitted to our hospital because of abdominal pain and vomiting. Abdominal computed tomography demonstrated free air and ascites in the abdominal cavity. In the pelvic cavity, a radiopaque linear shadow about 35mm in diameter was shown in the small intestine, and the stricture was exposed to the abdominal cavity. Therefore, a diagnosis of perforation of the small intestine due to ingestion of a foreign body and panperitonitis was made. Emergent laparotomy was performed. The intraoperative findings revealed perforation of the small intestine with a fish bone in the jejunum. Local inflammation at the perforation site was seen, and circulated wall thickness was observed at the distal side of the jejunum. Partial resection of the jejunum and anastomosis of jejuno-jejunostomy was performed. A pathological examination and immunohistochemical study of the resected specimen resulted in a diagnosis of malignant lymphoma of follicular lymphoma Grade 1. It is very difficult to identify the existence malignancy accompanied with gastrointestinal perforation with ingestion of a foreign body. In cases suspected of involving malignancy, careful observation during surgery is needed in order to avoid missing the accompanying malignancy. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Interfacing carbon nanotubes (CNT) with plants: enhancement of growth, water and ionic nutrient uptake in maize ( Zea mays) and implications for nanoagriculture

NASA Astrophysics Data System (ADS)

Tiwari, D. K.; Dasgupta-Schubert, N.; Villaseñor Cendejas, L. M.; Villegas, J.; Carreto Montoya, L.; Borjas García, S. E.

2014-06-01

The application of nano-biotechnology to crop-science/agriculture (`nanoagriculture') is a recent development. While carbon nanotubes (CNTs) have been shown to dramatically improve germination of some comestible plants, deficiencies in consistency of behavior and reproducibility arise, partially from the variability of the CNTs used. In this work, factory-synthesized multi-walled-CNTs (MWCNTs) of quality-controlled specifications were seen to enhance the germinative growth of maize seedlings at low concentrations but depress it at higher concentrations. Growth enhancement principally arose through improved water delivery by the MWCNT. Polarized EDXRF spectrometry showed that MWCNTs affect mineral nutrient supply to the seedling through the action of the mutually opposing forces of inflow with water and retention in the medium by the ion-CNT transient-dipole interaction. The effect varied with ion type and MWCNT concentration. The differences of the Fe tissue concentrations when relatively high equimolar Fe2+ or Fe3+ was introduced, implied that the ion-CNT interaction might induce redox changes to the ion. The tissue Ca2+ concentration manifested as the antipode of the Fe2+ concentration indicating a possible cationic exchange in the cell wall matrix. SEM images showed that MWCNTs perforated the black-layer seed-coat that could explain the enhanced water delivery. The absence of perforations with the introduction of FeCl2/FeCl3 reinforces the idea of the modification of MWCNT functionality by the ion-CNT interaction. Overall, in normal media, low dose MWCNTs were seen to be beneficial, improving water absorption, plant biomass and the concentrations of the essential Ca, Fe nutrients, opening a potential for possible future commercial agricultural applications.

Analysis of factors controlling sediment phosphorus flux potential of wetlands in Hulun Buir grassland by principal component and path analysis method.

PubMed

He, Jing; Su, Derong; Lv, Shihai; Diao, Zhaoyan; Ye, Shengxing; Zheng, Zhirong

2017-11-08

Phosphorus (P) flux potential can predict the trend of phosphorus release from wetland sediments to water and provide scientific parameters for further monitoring and management for phosphorus flux from wetland sediments to overlying water. Many studies have focused on factors affecting sediment P flux potential in sediment-water interface, but rarely on the relationship among these factors. In the present study, experiment on sediment P flux potential in sediment-water interface was conducted in six wetlands in Hulun Buir grassland, China and the relationships among sediment P flux potential in sediment-water interface, sediment physical properties, and sediment chemical characteristics were examined. Principal component analysis and path analysis were used to discuss these data in correlation coefficient, direct, and indirect effects on sediment P flux potential in sediment-water interface. Results indicated that the major factors affecting sediment P flux potential in sediment-water interface were amount of organophosphate-degradation bacterium in sediment, Ca-P content, and total phosphorus concentrations. The factors of direct influence sediment P flux potential were sediment Ca-P content, Olsen-P content, SOC content, and sediment Al-P content. The indirect influence sediment P flux potential in sediment-water interface was sediment Olsen-P content, sediment SOC content, sediment Ca-P content, and sediment Al-P content. And the standard multiple regression describing the relationship between sediment P flux potential in sediment-water interface and its major effect factors was Y = 5.849 - 1.025X 1  - 1.995X 2  + 0.188X 3  - 0.282X 4 (r = 0.9298, p < 0.01, n = 96), where Y is sediment P flux potential in sediment-water interface, X 1 is sediment Ca-P content, X 2 is sediment Olsen-P content, X 3 is sediment SOC content, and X 4 is sediment Al-P content. Therefore, future research will focus on these sediment properties to analyze the interrelation among sediment properties factors, main vegetable factors, and environment factors which influence the sediment P flux potential in sediment-water interface.

[Precision of navigation-assisted surgery of the thoracic and lumbar spine].

PubMed

Arand, M; Schempf, M; Hebold, D; Teller, S; Kinzl, L; Gebhard, F

2003-11-01

The goal of these studies was to evaluate the accuracy of in vivo and in vitro application of CT- and C-arm-based navigation at the thoracic and lumbar spine. With CT based navigation, 82 pedicle screws were consecutively inserted, 53 into the thoracic and 29 into the lumbar spine. Seven (13%) perforations were detected at the thoracic spine and two (7%) at the lumbar spine. Additionally, minor perforations below the thread depth were seen in six (11%) thoracic and in two (7%) lumbar instrumentation. With C-arm-based navigation, 74 screws were consecutively placed into 38 thoracic and 36 lumbar pedicles. Perforations were noted in ten (26%) thoracic and four (11%) lumbar implants. Minor perforations were observed in another nine (24%) thoracic and ten (28%) lumbar pedicles. The observer-independent and standardized in vitro study based on a transpedicular 3.2-mm drill hole aiming a 4-mm steel ball in a plastic bone model showed pedicle perforations of the drill canal only in thoracic vertebrae, 1 of 15 in CT-based and 3 of 15 in C-arm navigation. The quantitative calculation of the smallest distance between the central line through the drill canal and the center of the steel ball resulted in 1.4 mm (0.5-4.8 mm) for the CT-based navigation at the thoracic spine and in 1.8 mm (0.5-3 mm) at the lumbar spine. For the C-arm based navigation the distance was 2.6 mm (0.9-4.8 mm) for the thoracic spine and 2 mm (1.2-3 mm) for the lumbar spine. In our opinion, the clinical results of the comparative accuracy of CT- and C-arm-based navigation in the present study showed moderate advantages of the CT-based technique in the thoracic spine, whereas CT- and C-arm based navigation had comparable perforation rates at the lumbar pedicle. The results of the experimental study correlated with the clinical data.

Vinorelbine induced perforation of a metastatic gastric lesion.

PubMed

Mullally, W J; O'Súilleabháin, C B; Brady, C; O'Reilly, S

2017-08-01

Breast carcinoma metastasis to the gastrointestinal tract is rare and more frequently associated with lobular than ductal carcinoma (Borst and Ingold, Surg 114(4):637-641 [1]). The purpose of this article is to present a case based review of a unique gastrointestinal metastasis and literature review. A 46 year old lady with metastatic invasive ductal breast cancer was admitted to A&E with sudden onset of epigastric and left shoulder pain. She completed the first cycle of capecitabine/vinorelbine 1 week previously. Clinical examination revealed a tender epigastrium with rigidity in the upper abdomen. Free air under the diaphragm and a positive Rigler's sign was radiologically identified. A laparoscopy demonstrated a fibrinous exudate in the left upper quadrant consistent with a walled off lesser curvature gastric perforation. A subsequent oesophagogastroduodenoscopy (OGD) demonstrated a healed gastric ulcer of benign appearance; however the pathology confirmed metastatic breast carcinoma. Literature review confirmed no previously reported cases of vinorelbine induced gastric perforation. Four cases of metastatic breast cancer with gastric metastasis presenting with perforation were identified; three of these cases (Fra et al., Presse Med 25(26):1215 (1996) [2], Solis-Caxaj et al., Gastroenterol Clin Biol 28(1):91-92 (2004) [3], Ghosn et al., Bull Cancer 78(11):1071-1073 (1991) [4]), were in the French medical literature, including one male patient (Fra et al., Presse Med 25(26):1215 (1996) [2]) and at least one ductal breast carcinoma (Solis-Caxaj et al., Gastroenterol Clin Biol 28(1):91-92 (2004) [3]). The fourth case (van Geel et al., Ned Tijdschr Geneeskd 144(37):1761-1763 (2000) [5]), was in the Dutch medical literature and a lobular breast carcinoma. This case represents a rare complication of breast cancer chemotherapy, the subsequent significant benefit the patient received from treatment is consistent with the chemosensitivity to therapy that also resulted in gastric perforation. Five years after gastric perforation she resumed palliative chemotherapy after progression on sequential hormonal therapies.

A review of the management of perforated duodenal ulcers at a tertiary hospital in south western Nigeria.

PubMed

Etonyeaku, A C; Agbakwuru, E A; Akinkuolie, A A; Omotola, C A; Talabi, A O; Onyia, C U; Kolawole, O A; Aladesuru, O A

2013-12-01

Gastro-duodenal perforations are common and may complicate peptic ulcer disease. Management is often by surgical closure. To determine the patterns of presentation and mode of management of duodenal ulcer perforations. Retrospective review of patients with duodenal ulcer perforations seen at the Obafemi Awolowo University Teaching Hospital between June 2001 and July 2011. Patients' records were reviewed for demography, duration of disease, probable risk factors, type of surgery and complications. Data obtained was analyzed using SPSS 15.0. Forty- five patients were reviewed. There were 37 males (82.2%). Mean age was 39.7years (range 15-78years). There were 10 (22.6%) students and 8(17.8%) farmers. NSAIDs abuse (11), previous peptic ulcer disease (2), and no prior dyspeptic symptoms (20) constituted 24.4%, 4.4% and 44.4% respectively of cases. Seven (16%) patients presented less than 24 hours of onset of illness. Forty one perforations (91.1%) involved the first part of duodenum. Twenty two (49%) patients had Graham's omental patch. We had one (2.2%) failed repair and six (13.3%) mortalities. Late presentation of duodenal ulcer perforation is common with high mortality. Pragmatic surgical intervention with Graham's omentopexy with broad spectrum antibiotics is still commonly practiced.

A Novel Perforator Flap Training Model Using a Chicken Leg.

PubMed

Cifuentes, Ignacio J; Yañez, Ricardo A; Salisbury, Maria C; Rodriguez, José R; Varas, Julian E; Dagnino, Bruno L

2016-04-01

Living animal models are frequently used for perforator flap dissection training, but no ex vivo models have been described. The aim of this study is to present a novel nonliving model for perforator flap training based on a constant perforator in the chicken leg. A total of 15 chicken legs were used in this study. Anatomical dissection of the perforator was performed after its identification using ink injection, and in four of these specimens a perforator-based flap was raised. The anatomical dissection revealed a constant intramuscular perforator with a median length of 5.7 cm. Median proximal and distal vessel diameters were 0.93 and 0.4 mm, respectively. The median dissection time was 77.5 minutes. This study introduces a novel, affordable, and reproducible model for the intramuscular dissection of a perforator-based flap using an ex vivo animal model. Its consistent perforator and appropriate-sized vessels make it useful for training.

Spontaneous Intrahepatic Type II Gallbladder Perforation: A Rare Cause of Liver Abscess – Case Report

PubMed Central

Singh, Kumkum; Singh, Amit; Vidyarthi, Shivaji H; Jindal, Satyaprakash; Thounaojam, Chandra Kumar

2013-01-01

A liver abscess formation is a rare complication of a gallbladder perforation, with a cholecystohepatic communication. Niemeier, in 1934, classified free gallbladder perforations and generalised biliary peritonitis as an acute or a Type I gallbladder perforation, a pericholecystic abscess and localised peritonitis as a subacute or a Type II gallbladder perforation, and cholecystoenteric fistulas as chronic or Type III gallbladder perforations. We are describing a 50–year–old male patient who presented with right upper quadrant pain and was found to have an intrahepatic perforation of the gallbladder. Our patient had a Type II perforation. We have discussed the diagnostic work-up and the management of this rare entity. Due to the high mortality that can be caused by a delay in making the correct diagnosis, a gallbladder perforation represents a special diagnostic and surgical challenge. PMID:24179927

Electrophysiological properties of myocytes isolated from the mouse atrioventricular node: L-type ICa, IKr, If, and Na-Ca exchange.

PubMed

Choisy, Stéphanie C; Cheng, Hongwei; Orchard, Clive H; James, Andrew F; Hancox, Jules C

2015-11-01

The atrioventricular node (AVN) is a key component of the cardiac pacemaker-conduction system. This study investigated the electrophysiology of cells isolated from the AVN region of adult mouse hearts, and compared murine ionic current magnitude with that of cells from the more extensively studied rabbit AVN. Whole-cell patch-clamp recordings of ionic currents, and perforated-patch recordings of action potentials (APs), were made at 35-37°C. Hyperpolarizing voltage commands from -40 mV elicited a Ba(2+)-sensitive inward rectifier current that was small at diastolic potentials. Some cells (Type 1; 33.4 ± 2.2 pF; n = 19) lacked the pacemaker current, If, whilst others (Type 2; 34.2 ± 1.5 pF; n = 21) exhibited a clear If, which was larger than in rabbit AVN cells. On depolarization from -40 mV L-type Ca(2+) current, IC a,L, was elicited with a half maximal activation voltage (V0.5) of -7.6 ± 1.2 mV (n = 24). IC a,L density was smaller than in rabbit AVN cells. Rapid delayed rectifier (IK r) tail currents sensitive to E-4031 (5 μmol/L) were observed on repolarization to -40 mV, with an activation V0.5 of -10.7 ± 4.7 mV (n = 8). The IK r magnitude was similar in mouse and rabbit AVN. Under Na-Ca exchange selective conditions, mouse AVN cells exhibited 5 mmol/L Ni-sensitive exchange current that was inwardly directed negative to the holding potential (-40 mV). Spontaneous APs (5.2 ± 0.5 sec(-1); n = 6) exhibited an upstroke velocity of 37.7 ± 16.2 V/s and ceased following inhibition of sarcoplasmic reticulum Ca(2+) release by 1 μmol/L ryanodine, implicating intracellular Ca(2+) cycling in murine AVN cell electrogenesis. © 2015 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of the American Physiological Society and The Physiological Society.

Electrical tuning and transduction in short hair cells of the chicken auditory papilla.

PubMed

Tan, Xiaodong; Beurg, Maryline; Hackney, Carole; Mahendrasingam, Shanthini; Fettiplace, Robert

2013-04-01

The avian auditory papilla contains two classes of sensory receptor, tall hair cells (THCs) and short hair cells (SHCs), the latter analogous to mammalian outer hair cells with large efferent but sparse afferent innervation. Little is known about the tuning, transduction, or electrical properties of SHCs. To address this problem, we made patch-clamp recordings from hair cells in an isolated chicken basilar papilla preparation at 33°C. We found that SHCs are electrically tuned by a Ca(2+)-activated K(+) current, their resonant frequency varying along the papilla in tandem with that of the THCs, which also exhibit electrical tuning. The tonotopic map for THCs was similar to maps previously described from auditory nerve fiber measurements. SHCs also possess an A-type K(+) current, but electrical tuning was observed only at resting potentials positive to -45 mV, where the A current is inactivated. We predict that the resting potential in vivo is approximately -40 mV, depolarized by a standing inward current through mechanotransducer (MT) channels having a resting open probability of ∼0.26. The resting open probability stems from a low endolymphatic Ca(2+) concentration (0.24 mM) and a high intracellular mobile Ca(2+) buffer concentration, estimated from perforated-patch recordings as equivalent to 0.5 mM BAPTA. The high buffer concentration was confirmed by quantifying parvalbumin-3 and calbindin D-28K with calibrated postembedding immunogold labeling, demonstrating >1 mM calcium-binding sites. Both proteins displayed an apex-to-base gradient matching that in the MT current amplitude, which increased exponentially along the papilla. Stereociliary bundles also labeled heavily with antibodies against the Ca(2+) pump isoform PMCA2a.

Target-Selectivity of Parvalbumin-Positive Interneurons in Layer II of Medial Entorhinal Cortex in Normal and Epileptic Animals

PubMed Central

Armstrong, Caren; Wang, Jessica; Lee, Soo Yeun; Broderick, John; Bezaire, Marianne J; Lee, Sang-Hun; Soltesz, Ivan

2015-01-01

The medial entorhinal cortex layer II (MEClayerII) is a brain region critical for spatial navigation and memory, and it also demonstrates a number of changes in patients with, and animal models of, temporal lobe epilepsy (TLE). Prior studies of GABAergic microcircuitry in MEClayerII revealed that cholecystokinin-containing basket cells (CCKBCs) select their targets on the basis of the long-range projection pattern of the postsynaptic principal cell. Specifically, CCKBCs largely avoid reelin-containing principal cells that form the perforant path to the ipsilateral dentate gyrus and preferentially innervate non-perforant path forming calbindin-containing principal cells. We investigated whether parvalbumin containing basket cells (PVBCs), the other major perisomatic targeting GABAergic cell population, demonstrate similar postsynaptic target selectivity as well. In addition, we tested the hypothesis that the functional or anatomic arrangement of circuit selectivity is disrupted in MEClayerII in chronic TLE, using the repeated low-dose kainate model in rats. In control animals, we found that PVBCs innervated both principal cell populations, but also had significant selectivity for calbindin-containing principal cells in MEClayerII. However, the magnitude of this preference was smaller than for CCKBCs. In addition, axonal tracing and paired recordings showed that individual PVBCs were capable of contacting both calbindin and reelin-containing principal cells. In chronically epileptic animals, we found that the intrinsic properties of the two principal cell populations, the GABAergic perisomatic bouton numbers, and selectivity of the CCKBCs and PVBCs remained remarkably constant in MEClayerII. However, miniature IPSC frequency was decreased in epilepsy, and paired recordings revealed the presence of direct excitatory connections between principal cells in the MEClayerII in epilepsy, which is unusual in normal adult MEClayerII. Taken together, these findings advance our knowledge about the organization of perisomatic inhibition both in control and in epileptic animals. PMID:26663222

Target-selectivity of parvalbumin-positive interneurons in layer II of medial entorhinal cortex in normal and epileptic animals.

PubMed

Armstrong, Caren; Wang, Jessica; Yeun Lee, Soo; Broderick, John; Bezaire, Marianne J; Lee, Sang-Hun; Soltesz, Ivan

2016-06-01

The medial entorhinal cortex layer II (MEClayerII ) is a brain region critical for spatial navigation and memory, and it also demonstrates a number of changes in patients with, and animal models of, temporal lobe epilepsy (TLE). Prior studies of GABAergic microcircuitry in MEClayerII revealed that cholecystokinin-containing basket cells (CCKBCs) select their targets on the basis of the long-range projection pattern of the postsynaptic principal cell. Specifically, CCKBCs largely avoid reelin-containing principal cells that form the perforant path to the ipsilateral dentate gyrus and preferentially innervate non-perforant path forming calbindin-containing principal cells. We investigated whether parvalbumin containing basket cells (PVBCs), the other major perisomatic targeting GABAergic cell population, demonstrate similar postsynaptic target selectivity as well. In addition, we tested the hypothesis that the functional or anatomic arrangement of circuit selectivity is disrupted in MEClayerII in chronic TLE, using the repeated low-dose kainate model in rats. In control animals, we found that PVBCs innervated both principal cell populations, but also had significant selectivity for calbindin-containing principal cells in MEClayerII . However, the magnitude of this preference was smaller than for CCKBCs. In addition, axonal tracing and paired recordings showed that individual PVBCs were capable of contacting both calbindin and reelin-containing principal cells. In chronically epileptic animals, we found that the intrinsic properties of the two principal cell populations, the GABAergic perisomatic bouton numbers, and selectivity of the CCKBCs and PVBCs remained remarkably constant in MEClayerII . However, miniature IPSC frequency was decreased in epilepsy, and paired recordings revealed the presence of direct excitatory connections between principal cells in the MEClayerII in epilepsy, which is unusual in normal adult MEClayerII . Taken together, these findings advance our knowledge about the organization of perisomatic inhibition both in control and in epileptic animals. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.

Decay of quadrupole-octupole 1- states in 40Ca and 140Ce

NASA Astrophysics Data System (ADS)

Derya, V.; Tsoneva, N.; Aumann, T.; Bhike, M.; Endres, J.; Gooden, M.; Hennig, A.; Isaak, J.; Lenske, H.; Löher, B.; Pietralla, N.; Savran, D.; Tornow, W.; Werner, V.; Zilges, A.

2016-03-01

Background: Two-phonon excitations originating from the coupling of two collective one-phonon states are of great interest in nuclear structure physics. One possibility to generate low-lying E 1 excitations is the coupling of quadrupole and octupole phonons. Purpose: In this work, the γ -decay behavior of candidates for the (21+⊗31-)1- state in the doubly magic nucleus 40Ca and in the heavier and semimagic nucleus 140Ce is investigated. Methods: (γ ⃗,γ') experiments have been carried out at the High Intensity γ -ray Source (HI γ S ) facility in combination with the high-efficiency γ -ray spectroscopy setup γ3 consisting of HPGe and LaBr3 detectors. The setup enables the acquisition of γ -γ coincidence data and, hence, the detection of direct decay paths. Results: In addition to the known ground-state decays, for 40Ca the decay into the 31- state was observed, while for 140Ce the direct decays into the 21+ and the 02+ state were detected. The experimentally deduced transition strengths and excitation energies are compared to theoretical calculations in the framework of EDF theory plus QPM approach and systematically analyzed for N =82 isotones. In addition, negative parities for two J =1 states in 44Ca were deduced simultaneously. Conclusions: The experimental findings together with the theoretical calculations support the two-phonon character of the 11- excitation in the light-to-medium-mass nucleus 40Ca as well as in the stable even-even N =82 nuclei.

Endoscope-assisted laparoscopic repair of perforated peptic ulcers.

PubMed

Lee, Kun-Hua; Chang, Hung-Chi; Lo, Chong-Jeh

2004-04-01

Laparoscopic repairs for perforated peptic ulcer (PPU) are likely to fail in patients with shock, gastric outlet obstruction, or large perforations. This prospective study was performed to evaluate a revised approach of laparoscopic repair with endoscopic assistance to treat these patients. Between April 2001 and February 2002, 30 consecutive patients with PPU were enrolled in this study. The mean age was 43.1 +/- 12.2 years. Male to female ratio was 27:2. One patient was excluded from laparoscopic repair due to a gastric outlet obstruction. The other 29 patients were managed according to a protocol of preoperative upper endoscopy and laparoscopic intracorporeal suture repair with an omental patch. The average operative time was 58.1 +/- 13.5 minutes (range, 36-96 min). The average diameter of perforation was 4.2 +/- 2.0 mm (range, 1-12 mm). The average time to resume oral fluids was 3.2 +/- 0.8 days (range, 2-8 days). The average hospital stay was 4.7 +/- 1.1 days (range, 3-10 days). There was no leakage or mortality. Most patients did not receive parenteral analgesics postoperatively. We conclude that endoscope-assisted laparoscopic repair for PPU is safe and effective. This revised technique allows surgeons to exclude patients who are likely to fail the laparoscopic repair.

Evaluation of a Perforated Drug Delivery System in Mice for Prolonged and Constant Release of a Hydrophilic Drug

DTIC Science & Technology

2012-02-17

A drug delivery system (DDS) consisting of a perforated microtube ( polyimide , inside diameter= 1.8 mm, tube length= 20 mm, hole size= 0.15 mm) was... biocompatible and capable of long-term constant release of hydrophilic drugs such as sodium fluorescein.

To Break or to Brake Neuronal Network Accelerated by Ammonium Ions?

PubMed Central

Dynnik, Vladimir V.; Kononov, Alexey V.; Sergeev, Alexander I.; Teplov, Iliya Y.; Tankanag, Arina V.; Zinchenko, Valery P.

2015-01-01

Purpose The aim of present study was to investigate the effects of ammonium ions on in vitro neuronal network activity and to search alternative methods of acute ammonia neurotoxicity prevention. Methods Rat hippocampal neuronal and astrocytes co-cultures in vitro, fluorescent microscopy and perforated patch clamp were used to monitor the changes in intracellular Ca2+- and membrane potential produced by ammonium ions and various modulators in the cells implicated in neural networks. Results Low concentrations of NH4Cl (0.1–4 mM) produce short temporal effects on network activity. Application of 5–8 mM NH4Cl: invariably transforms diverse network firing regimen to identical burst patterns, characterized by substantial neuronal membrane depolarization at plateau phase of potential and high-amplitude Ca2+-oscillations; raises frequency and average for period of oscillations Ca2+-level in all cells implicated in network; results in the appearance of group of «run out» cells with high intracellular Ca2+ and steadily diminished amplitudes of oscillations; increases astrocyte Ca2+-signalling, characterized by the appearance of groups of cells with increased intracellular Ca2+-level and/or chaotic Ca2+-oscillations. Accelerated network activity may be suppressed by the blockade of NMDA or AMPA/kainate-receptors or by overactivation of AMPA/kainite-receptors. Ammonia still activate neuronal firing in the presence of GABA(A) receptors antagonist bicuculline, indicating that «disinhibition phenomenon» is not implicated in the mechanisms of networks acceleration. Network activity may also be slowed down by glycine, agonists of metabotropic inhibitory receptors, betaine, L-carnitine, L-arginine, etc. Conclusions Obtained results demonstrate that ammonium ions accelerate neuronal networks firing, implicating ionotropic glutamate receptors, having preserved the activities of group of inhibitory ionotropic and metabotropic receptors. This may mean, that ammonia neurotoxicity might be prevented by the activation of various inhibitory receptors (i.e. by the reinforcement of negative feedback control), instead of application of various enzyme inhibitors and receptor antagonists (breaking of neural, metabolic and signaling systems). PMID:26217943

Effect of Gallic Acid on Dementia Type of Alzheimer Disease in Rats: Electrophysiological and Histological Studies.

PubMed

Hajipour, Somayeh; Sarkaki, Alireza; Farbood, Yaghoob; Eidi, Akram; Mortazavi, Pejman; Valizadeh, Zohreh

2016-04-01

To study the effect of gallic acid (GA) on hippocampal long-term potentiation (LTP) and histological changes in animal model of Alzheimer disease (AD) induced by beta-amyloid (Aβ). Sixty-four adult male Wistar rats (300±20 g) were divided into 8 groups: 1) Control (Cont); 2) AD; 3) Sham; 4-7) AD+GA (50, 100, and 200 mg/kg for 10 days, orally) or vehicle, 8) Cont+GA100, Aβ (1μg/μL in each site) was infused into hippocampus bilaterally. Changes of amplitude and slope of LTP induced in hippocampal dentate gyrus (DG) were evaluated by high frequency stimulation (HFS) of perforant path (PP). Data showed that LTP amplitude and area under curve significantly impaired in AD rats (P<0.001), while significantly improved in AD rats treated with GA (P<0.05, P<0.01). Current findings suggest that GA reduces neural damage and brain amyloid neuropathology and improves cognitive function via free radicals scavenging and inhibiting oligomerization of Aβ but with no effect on healthy rats.

Intercostal artery perforator propeller flap for reconstruction of trunk defects following sarcoma resection.

PubMed

Zang, Mengqing; Yu, Shengji; Xu, Libin; Zhao, Zhenguo; Zhu, Shan; Ding, Qiang; Liu, Yuanbo

2015-06-01

Trunk defects following soft tissue sarcoma resection are usually managed by myocutaneous flaps or free flaps. However, harvesting muscle will cause functional morbidities and some trunk regions lack reliable recipient vessels. The intercostal arteries give off multiple perforators, which distribute widely over the trunk and can supply various pedicle flaps. Our purpose is to use various intercostal artery perforator propeller flaps for trunk oncologic reconstruction. Between November 2013 and July 2014, nine intercostal artery perforator propeller flaps were performed in seven patients to reconstruct the defects following sarcoma resection in different regions of the trunk, including the back, lumbar, chest, and abdomen. Two perforators from intercostal arteries were identified for each flap using Doppler ultrasound probe adjacent to the defect. The perforator with visible pulsation was chosen as the pedicle vessel. An elliptical flap was raised and rotated in a propeller fashion to repair the defects. There were one dorsal intercostal artery perforator flap, four dorsolateral intercostal artery perforator flaps, three lateral intercostal artery perforator flaps, and one anterior intercostal artery perforator flap. The mean skin paddle dimension was 9.38 cm in width (range 6-14 cm) and 21.22 cm in length (range 13-28 cm). All intercostal artery perforator flaps survived completely, except for marginal necrosis in one flap harvested close to the previous flap donor site. The intercostal artery perforator propeller flap provides various and valuable options in our reconstructive armamentarium for trunk oncologic reconstruction. To our knowledge, this is the first case series of using intercostal artery perforator propeller flaps for trunk oncologic reconstruction and clinical application of dorsolateral intercostal artery perforator flaps. Copyright © 2015 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

The Use of Magnetic Resonance Imaging in Planning a Pedicled Perforator Flap for Pressure Sores in the Gluteal Region.

PubMed

Park, Sun-June; Lee, Kyeong-Tae; Jeon, Byung-Joon; Woo, Kyong-Je

2018-04-01

Pedicled perforator flaps (PPFs) have been widely used to treat pressure sores in the gluteal region. Selection of a reliable perforator is crucial for successful surgical treatment of pressure sores using PPFs. In this study, we evaluate the role of magnetic resonance imaging (MRI) in planning PPF reconstruction of pressure sores in the gluteal region. A retrospective chart review was performed in patients who had undergone these PPF reconstructions and who had received preoperative MRI. Preoperatively, the extent of infection and necrotic tissue was evaluated using MRI, and a reliable perforator was identified, considering the perforator location in relation to the defect, perforator size, and perforator courses. Intraoperatively, the targeted perforator was marked on the skin at the locations measured on the MRI images, and the marked location was confirmed using intraoperative handheld Doppler. Superior gluteal artery, inferior gluteal artery, or parasacral perforators were used for the PPFs. Surgical outcomes were evaluated. A total of 12 PPFs were performed in 12 patients. Superior gluteal artery perforator flaps were performed in 7 patients, inferior gluteal artery perforator flaps were performed in 3 patients, and parasacral perforator flaps were performed in 2 patients. We could identify a reliable perforator on MRI, and it was found at the predicted locations in all cases. There was only one case of partial flap necrosis. There was no recurrence of the pressure sores during the mean follow-up period of 6.7 months (range = 3-15 months). In selected patients with gluteal pressure sores, MRI is a suitable means for not only providing information about disease extent and comorbidities but also for evaluating perforators for PPF reconstructions.

30 CFR 203.1 - What is MMS's authority to grant royalty relief?

Code of Federal Regulations, 2010 CFR

2010-07-01

... (water less than 400 meters deep) and you produce from an ultra-deep well (top of the perforated interval... less than 400 meters deep and you produce from a deep well (top of the perforated interval is at least... from any lease if: (1) Your lease is in deep water (water at least 200 meters deep); (2) Your lease is...

Perforated Solitary Diverticulitis of the Ascending Colon

DTIC Science & Technology

2005-06-01

postoperative day 6. DISCUSSION Diverticuli of the right colon exist in approximately 1% to 5% of patients with diverticular disease .1-3 They are...ORIGINAL REPORTS Perforated Solitary Diverticulitis of the Ascending Colon CPT David S. Kauvar, MC, USA, MAJ, Jayson Aydelotte, MC, USA, and MAJ...Michael Harnisch, MC, USA Department of Surgery, Brooke Army Medical Center, Fort Sam Houston, Texas KEY WORDS: solitary colon diverticulum

Argon plasma coagulation in the right and left colon: safety-risk profile of the 60W-1.2 l/min setting.

PubMed

Panos, Marios Z; Koumi, Andriani

2014-05-01

The 40W-0.8 l/min setting is widely recommended for argon plasma coagulation (APC) in the right colon. Until March 2012, we used the 60W-1.2 l/min setting for all sites of the colon. By auditing our experience, we assessed the safety-risk profile of the 60W-1.2 l/min setting in the right and left colon. All cases treated with APC by a single endoscopist, using the 60W-1.2 l/min setting for all sites of the colon between October 2001 and December 2007 were identified retrospectively and site, type, number of lesions, and complications were recorded. Between January 2008 and March 2012, information was recorded prospectively. In the retrospective audit, 290 lesions (101 cecum/ascending, 120 sigmoid/descending, 69 transverse) were treated in 241 patient endoscopies. There were no perforations. In the prospective audit, 156 lesions (83 cecum/ascending, 47 sigmoid/descending, 26 transverse) were treated in 132 patient endoscopies. There was 1/83 (1.2%) perforation in the cecum/ascending colon and none in the transverse or sigmoid/descending (n.s.). Combined, the results yield a cecal/ascending perforation rate of 1/153 (0.6%) patient endoscopies, 1/184 (0.5%) lesions treated and overall perforation rate for all sites of the colon of 1/373 (0.3%) patient endoscopies and 1/446 (0.2%) lesions. Post-polypectomy syndrome and delayed bleeding each occurred in 3/373 (0.8%) patient endoscopies and 3/446 (0.7%) lesions. There were no deaths. In the cecum and ascending colon, the APC perforation rate at the 60W-1.2 l/min setting was no higher than in the left colon and is similar to that reported in previously published series. Therefore, it appears safe, provided the precautions we describe are strictly followed.

Inlay butterfly cartilage tympanoplasty in the treatment of dry central perforated chronic otitis media as an effective and time-saving procedure.

PubMed

Haksever, Mehmet; Akduman, Davut; Solmaz, Fevzi; Gündoğdu, Ercan

2015-04-01

The aim of this study is to compare the inlay butterfly transcanal cartilage tympanoplasty with the conventional underlay tympanoplasty. Operation time, pre- and postoperative hearing levels, successful closure rate of tympanic membrane (take rate) and long-term re-perforation in dry perforated chronic otitis media were evaluated. The study design consists of case series with a chart review. The study settings are tertiary referral center. Of the 72 patients (age range 14-57 years) with dry perforated chronic otitis media, 29 patients underwent inlay butterfly transcanal cartilage tympanoplasty (group 1) and 43 patients underwent conventional underlay tympanoplasty without mastoidectomy (group 2) between January 2010 and June 2012. The outcome measures were the duration of surgery, "take rate" at the 30th postoperative day and the audiometric results at the 45th postoperative day. Long-term re-perforation was evaluated at least postoperative 1 year. The graft take rate was 96.5 % in group 1 and 90.7 % in group 2 at the 30th postoperative day (p > 0.05). Mean air-bone gap was improved from 18.8 ± 8.09 to 11.9 ± 7.12 dB in group 1 and from 21.9 ± 7.32 to 11.6 ± 8.43 dB in group 2. The improvement of air-bone gap in both groups was statistically significant (p < 0.05) but the improvement between the groups was not statistically significant (p > 0.05). The average duration of the surgery was 29.9 ± 5.38 min for inlay tympanoplasty group and 58.9 ± 12.1 min for underlay tympanoplasty group (p < 0.05). Two patients in group 2 had re-perforations after an initial take of the graft in 1-year follow-up period. Inlay butterfly transcanal cartilage tympanoplasty is a good choice in selected cases. Although this technique has the similar take rate and audiological results with conventional underlay tympanoplasty, it is a time-saving procedure.

The accuracy and safety of fluoroscopically guided percutaneous pedicle screws in the lumbosacral junction and the lumbar spine: a review of 880 screws.

PubMed

Chiu, C K; Kwan, M K; Chan, C Y W; Schaefer, C; Hansen-Algenstaedt, N

2015-08-01

We undertook a retrospective study investigating the accuracy and safety of percutaneous pedicle screws placed under fluoroscopic guidance in the lumbosacral junction and lumbar spine. The CT scans of patients were chosen from two centres: European patients from University Medical Center Hamburg-Eppendorf, Germany, and Asian patients from the University of Malaya, Malaysia. Screw perforations were classified into grades 0, 1, 2 and 3. A total of 880 percutaneous pedicle screws from 203 patients were analysed: 614 screws from 144 European patients and 266 screws from 59 Asian patients. The mean age of the patients was 58.8 years (16 to 91) and there were 103 men and 100 women. The total rate of perforation was 9.9% (87 screws) with 7.4% grade 1, 2.0% grade 2 and 0.5% grade 3 perforations. The rate of perforation in Europeans was 10.4% and in Asians was 8.6%, with no significant difference between the two (p = 0.42). The rate of perforation was the highest in S1 (19.4%) followed by L5 (14.9%). The accuracy and safety of percutaneous pedicle screw placement are comparable to those cited in the literature for the open method of pedicle screw placement. Greater caution must be taken during the insertion of L5 and S1 percutaneous pedicle screws owing to their more angulated pedicles, the anatomical variations in their vertebral bodies and the morphology of the spinal canal at this location. ©2015 The British Editorial Society of Bone & Joint Surgery.

[Colonic perforation during colonoscopy. 100 cases].

PubMed

Hureau, J; Avtan, L; Germain, M; Blanc, D; Chaussade, G

1992-01-01

The analysis of 100 cases of colon perforation during colposcopic examinations highly demonstrates such a statement. The perforation risk during colposcopies is generally of the order of 0.2% for a diagnosis coloscopy. According to the statistic data used, it can reach 0.5 to 3% in therapy coloscopy. This is a risk inherent to the technique used. It is thus required to analyse the causes and take the appropriate measures to reduce it to a minimum. Mortality due to such a complication remains high (14%), i.e about 0.015 to 0.1% (#2/10000) of all colposcopies. In 11% of the patients, serious sequelae are to be observed. This demonstrates the significance of the medico-legal problem set by these perforations during colposcopies. The whole personnel responsibility can be involved: colposcopist, surgeon, anesthetist and hospital unit.

The effect of surgical subspecialization on outcomes in peptic ulcer disease complicated by perforation and bleeding.

PubMed

Robson, Andrew J; Richards, Jennifer M J; Ohly, Nicholas; Nixon, Stephen J; Paterson-Brown, Simon

2008-07-01

Emergency surgical services in Edinburgh were restructured in July 2002 to deliver subspecialist management of colorectal and upper-gastrointestinal emergencies on separate sites. The effect of emergency subspecialization on outcome from perforated and bleeding peptic ulceration was assessed. All patients admitted with complicated peptic ulceration (January 2000-February 2005) were identified from a prospectively compiled database. Perforation: 148 patients were admitted with perforation before the service reorganization (period A - 31 months) of whom 126 (85.1%) underwent surgery; 135 patients were admitted in period B (31 months) of whom 114 (84.4%) were managed operatively. The in-hospital mortality was lower in period B (14/135, 10.4%) than period A (30/148, 20.3%; P = 0.023; relative risk (RR), 0.51; 95% confidence interval (CI), 0.28-0.91). There was a significantly higher rate of gastric resection in the second half of the study (period A 1/126 vs. period B 8/114; P = 0.015; RR, 8.84; 95% CI, 1.48-54.34). Length of hospital stay was similar for both groups. Bleeding: 51 patients underwent operative management of bleeding peptic ulceration in period A and 51 in period B. There were no differences in length of stay or mortality between these two groups. Restructuring of surgical services with emergency subspecialization was associated with lower mortality for perforated peptic ulceration. Subspecialist experience, intraoperative decision-making, and improved postoperative care have all contributed to this improvement.

Pulsed infrared radiation excites cultured neonatal spiral and vestibular ganglion neurons by modulating mitochondrial calcium cycling

PubMed Central

Lumbreras, Vicente; Bas, Esperanza; Gupta, Chhavi

2014-01-01

Cochlear implants are currently the most effective solution for profound sensorineural hearing loss, and vestibular prostheses are under development to treat bilateral vestibulopathies. Electrical current spread in these neuroprostheses limits channel independence and, in some cases, may impair their performance. In comparison, optical stimuli that are spatially confined may result in a significant functional improvement. Pulsed infrared radiation (IR) has previously been shown to elicit responses in neurons. This study analyzes the response of neonatal rat spiral and vestibular ganglion neurons in vitro to IR (wavelength = 1,863 nm) using Ca2+ imaging. Both types of neurons responded consistently with robust intracellular Ca2+ ([Ca2+]i) transients that matched the low-frequency IR pulses applied (4 ms, 0.25–1 pps). Radiant exposures of ∼637 mJ/cm2 resulted in continual neuronal activation. Temperature or [Ca2+] variations in the media did not alter the IR-evoked transients, ruling out extracellular Ca2+ involvement or primary mediation by thermal effects on the plasma membrane. While blockage of Na+, K+, and Ca2+ plasma membrane channels did not alter the IR-evoked response, blocking of mitochondrial Ca2+ cycling with CGP-37157 or ruthenium red reversibly inhibited the IR-evoked [Ca2+]i transients. Additionally, the magnitude of the IR-evoked transients was dependent on ryanodine and cyclopiazonic acid-dependent Ca2+ release. These results suggest that IR modulation of intracellular calcium cycling contributes to stimulation of spiral and vestibular ganglion neurons. As a whole, the results suggest selective excitation of neurons in the IR beam path and the potential of IR stimulation in future auditory and vestibular prostheses. PMID:24920028

Pulsed infrared radiation excites cultured neonatal spiral and vestibular ganglion neurons by modulating mitochondrial calcium cycling.

PubMed

Lumbreras, Vicente; Bas, Esperanza; Gupta, Chhavi; Rajguru, Suhrud M

2014-09-15

Cochlear implants are currently the most effective solution for profound sensorineural hearing loss, and vestibular prostheses are under development to treat bilateral vestibulopathies. Electrical current spread in these neuroprostheses limits channel independence and, in some cases, may impair their performance. In comparison, optical stimuli that are spatially confined may result in a significant functional improvement. Pulsed infrared radiation (IR) has previously been shown to elicit responses in neurons. This study analyzes the response of neonatal rat spiral and vestibular ganglion neurons in vitro to IR (wavelength = 1,863 nm) using Ca(2+) imaging. Both types of neurons responded consistently with robust intracellular Ca(2+) ([Ca(2+)]i) transients that matched the low-frequency IR pulses applied (4 ms, 0.25-1 pps). Radiant exposures of ∼637 mJ/cm(2) resulted in continual neuronal activation. Temperature or [Ca(2+)] variations in the media did not alter the IR-evoked transients, ruling out extracellular Ca(2+) involvement or primary mediation by thermal effects on the plasma membrane. While blockage of Na(+), K(+), and Ca(2+) plasma membrane channels did not alter the IR-evoked response, blocking of mitochondrial Ca(2+) cycling with CGP-37157 or ruthenium red reversibly inhibited the IR-evoked [Ca(2+)]i transients. Additionally, the magnitude of the IR-evoked transients was dependent on ryanodine and cyclopiazonic acid-dependent Ca(2+) release. These results suggest that IR modulation of intracellular calcium cycling contributes to stimulation of spiral and vestibular ganglion neurons. As a whole, the results suggest selective excitation of neurons in the IR beam path and the potential of IR stimulation in future auditory and vestibular prostheses. Copyright © 2014 the American Physiological Society.

[Localization of perforators in the lower leg by digital antomy imaging methods].

PubMed

Wei, Peng; Ma, Liang-Liang; Fang, Ye-Dong; Xia, Wei-Zhi; Ding, Mao-Chao; Mei, Jin

2012-03-01

To offer both the accurate three-dimensional anatomical information and algorithmic morphology of perforators in the lower leg for perforator flaps design. The cadaver was injected with a modified lead oxide-gelatin mixture. Radiography was first performed and the images were analyzed using the software Photoshop and Scion Image. Then spiral CT scan was also performed and 3-dimensional images were reconstructed with MIMICS 10.01 software. There are (27 +/- 4) perforators whose outer diameter > or = 0.5 mm ( average, 0.8 +/- 0.2 mm). The average pedicle length within the superficial fascia is (37.3 +/- 18.6) mm. The average supplied area of each perforator is (49.5 +/- 25.5) cm2. The three-dimensional model displayed accurate morphology structure and three-dimensional distribution of the perforator-to- perforator and perforator-to-source artery. The 3D reconstruction model can clearly show the geometric, local details and three-dimensional distribution. It is a considerable method for the study of morphological characteristics of the individual perforators in human calf and preoperative planning of the perforator flap.

Multiple, Pan-Enteric Perforation Secondary to Intestinal Tuberculosis

PubMed Central

Masood, Irfan; Majid, Zain; Rafiq, Ali; Rind, Waqas; Zia, Aisha; Raza, Sajjad

2015-01-01

Free perforation is one of the most feared complications of the intestinal tuberculosis. The terminal ileum is the most common site of perforation, while the majority of (90%) perforations are solitary. Herein, we describe a case of a 25-year-old male who presented with generalized peritonitis requiring an emergency exploratory laparotomy, which revealed pan-enteric perforation characterized by multiple perforations of the small bowel extending 10–15 cm from the DJ flexure up to the terminal ileum. The perforations were primarily closed, while 6–8 cm of the diseased terminal ileum was resected and the two ends were brought out as double-barreled ostomy. To the best of our knowledge, such an extensive tuberculous perforation of the small bowel has not been previously reported in the literature before. PMID:26798540

Investigation of Perforated Convergent-divergent Diffusers with Initial Boundary Layer

NASA Technical Reports Server (NTRS)

Weinstein, Maynard I

1950-01-01

An experimental investigation was made at Mach number 1.90 of the performance of a series of perforated convergent-divergent supersonic diffusers operating with initial boundary layer, which was induced and controlled by lengths of cylindrical inlets affixed to the diffusers. Supercritical mass-flow and peak total-pressure recoveries were decreased slightly by use of the longest inlets (4 inlet diameters in length). Combinations of cylindrical inlets, perforated diffusers, and subsonic diffuser were evaluated as simulated wind tunnels having second throats. Comparisons with noncontracted configurations of similar scale indicated conservatively computed power reductions of 25 percent.

Temperature driven annealing of perforations in bicellar model membranes.

PubMed

Nieh, Mu-Ping; Raghunathan, V A; Pabst, Georg; Harroun, Thad; Nagashima, Kazuomi; Morales, Hannah; Katsaras, John; Macdonald, Peter

2011-04-19

Bicellar model membranes composed of 1,2-dimyristoylphosphatidylcholine (DMPC) and 1,2-dihexanoylphosphatidylcholine (DHPC), with a DMPC/DHPC molar ratio of 5, and doped with the negatively charged lipid 1,2-dimyristoylphosphatidylglycerol (DMPG), at DMPG/DMPC molar ratios of 0.02 or 0.1, were examined using small angle neutron scattering (SANS), (31)P NMR, and (1)H pulsed field gradient (PFG) diffusion NMR with the goal of understanding temperature effects on the DHPC-dependent perforations in these self-assembled membrane mimetics. Over the temperature range studied via SANS (300-330 K), these bicellar lipid mixtures exhibited a well-ordered lamellar phase. The interlamellar spacing d increased with increasing temperature, in direct contrast to the decrease in d observed upon increasing temperature with otherwise identical lipid mixtures lacking DHPC. (31)P NMR measurements on magnetically aligned bicellar mixtures of identical composition indicated a progressive migration of DHPC from regions of high curvature into planar regions with increasing temperature, and in accord with the "mixed bicelle model" (Triba, M. N.; Warschawski, D. E.; Devaux, P. E. Biophys. J.2005, 88, 1887-1901). Parallel PFG diffusion NMR measurements of transbilayer water diffusion, where the observed diffusion is dependent on the fractional surface area of lamellar perforations, showed that transbilayer water diffusion decreased with increasing temperature. A model is proposed consistent with the SANS, (31)P NMR, and PFG diffusion NMR data, wherein increasing temperature drives the progressive migration of DHPC out of high-curvature regions, consequently decreasing the fractional volume of lamellar perforations, so that water occupying these perforations redistributes into the interlamellar volume, thereby increasing the interlamellar spacing. © 2011 American Chemical Society

Glove perforation time and frequency in total hip arthroplasty procedures.

PubMed

Kaya, Ibrahim; Uğraş, Akin; Sungur, Ibrahim; Yilmaz, Murat; Korkmaz, Musa; Cetinus, Ercan

2012-01-01

The aim of the present study was to investigate glove perforation rate and time and evaluate the factors affecting glove perforation in total hip arthroplasty (THA). Nine hundred seventy-nine gloves used in 57 THA procedures were assessed according to the perforation. Forty-four (77.2%) procedures were primary THA and 13 (22.8%) were revision THA. Gloves were changed when perforated, become dirty with blood or blood products, and before bone cementing. All gloves were filled with water at the end of the operation and controlled for perforation. Two hundred and one surgical gloves used during scrubbing and removed after draping the patient were examined as the control group. The location (which finger), number and time of the perforation, surgery type and duration, and distribution of the perforation location according to the surgical team were assessed. Patients' mean age was 62.9 ± 14.6 (range: 33 to 97) years and the mean surgery duration was 162.9 ± 32.0 minutes. Thirty-two glove perforations were noted in 19 of the operations. Of these perforations, 28 belonged to the surgeons and first assistants. There was no significant difference between the dominant or non-dominant hand according to the location of perforations. Perforations in the first and second fingers of the gloves accounted for 81.3% of all perforations. There was no significant difference in terms of number of gloves used, perforation numbers and operation duration between the primary and revision THA procedures. Two perforated gloves (0.99%) were found in the control group and the difference between the number of perforations in the control and study groups was significant (p=0.048). We recommend the use of two pairs of gloves to avoid the risk of contamination and protect the surgical team from infectious disease in major surgeries like THA. Surgical gloves should be changed when they are excessively contaminated with surgical fluids and the surgeon and first assistant should also change their outer gloves at an average of every 90 minutes.

[Propeller facial artery perforator flap for repairing defect after resection of skin malignant tumor at upper lip].

PubMed

Yao, Yuanzhen; Tang, Xiujun; Wang, Dali; Wei, Zairong; Wang, Bo; Deng, Chengliang; Zhang, Ziyang; Jin, Wenhu

2018-02-01

To explore the effectiveness of propeller facial artery perforator flap to repair the defect after resection of skin malignant tumor at upper lip. Between July 2012 and January 2017, 17 cases with skin malignant tumor at upper lip underwent tumor resection and the remained defect was repaired with propeller facial artery perforator flap. Among the 17 patients, 3 were male and 14 were female, with an average age of 57 years (range, 35-82 years). There were 5 cases of squamous cell carcinoma and 12 cases of basal cell carcinoma. The disease duration ranged from 4 months to 11 years with an average of 20 months. The tumor size ranged from 1.4 cm×0.3 cm to 3.1 cm×1.4 cm. The extended resection of the tumor tissue was performed according to the characters of tumor. According to the location, size, and shape of the defect and the position of facial artery perforator explored with Doppler ultrasonography, the propeller facial artery perforator flap was designed to repair the defect and partial donor site. The flap size ranged from 5 cm×2 cm to 7 cm×3 cm. The length of the perforator pedicle was 0.5-1.0 cm with an average of 0.8 cm. The defect at donor site was directly closed. Cyanosis occurred in 3 cases of the distal flap after operation, then healing after symptomatic treatment. The remaining flaps survived successfully and the wound healed by first intention. Primary healing was obtained in the donor site. All the patients were followed up 6-36 months with an average of 18 months. The shape of the patient's upper lip was good and the scar on the donor site was unconspicuous. There was no lip deformity, ala nasi deflection, facial tension, entilation dysfunction, or recurrence of tumor during follow-up. At last follow-up, the results of self-evaluation were very satisfactory in 13 cases and satisfactory in 4 cases. Based on multiple advantages of good blood supply, large rotation range, aesthetic outcome, and slight injury of the donor site, propeller facial artery perforator flap is not only an optimal choice for repairing upper lip defect after resection of skin malignant tumors, but also can achieve good functional and cosmetic effectiveness.

A Novel Perforator Flap Training Model Using a Chicken Leg

PubMed Central

Cifuentes, Ignacio J.; Yañez, Ricardo A.; Salisbury, Maria C.; Rodriguez, José R.; Varas, Julian E.; Dagnino, Bruno L.

2016-01-01

Introduction  Living animal models are frequently used for perforator flap dissection training, but no ex vivo models have been described. The aim of this study is to present a novel nonliving model for perforator flap training based on a constant perforator in the chicken leg. Methods  A total of 15 chicken legs were used in this study. Anatomical dissection of the perforator was performed after its identification using ink injection, and in four of these specimens a perforator-based flap was raised. Results  The anatomical dissection revealed a constant intramuscular perforator with a median length of 5.7 cm. Median proximal and distal vessel diameters were 0.93 and 0.4 mm, respectively. The median dissection time was 77.5 minutes. Conclusion  This study introduces a novel, affordable, and reproducible model for the intramuscular dissection of a perforator-based flap using an ex vivo animal model. Its consistent perforator and appropriate-sized vessels make it useful for training. PMID:27616823

Perforated peptic ulcer and short-term mortality among tramadol users

PubMed Central

Tørring, Marie L; Riis, Anders; Christensen, Steffen; Thomsen, Reimar W; Jepsen, Peter; Søndergaard, Jens; Sørensen, Henrik T

2008-01-01

Aim Use of nonsteroidal anti-inflammatory drugs (NSAIDs) increases risk and worsens prognosis for patients with complicated peptic ulcer disease. Therefore, patients who are at high risk of peptic ulcer often use tramadol instead of NSAIDs. Tramadol's effect on peptic ulcer prognosis is unknown. The aim was to examine mortality in the 30 days following hospitalization for perforated peptic ulcer among tramadol and NSAID users compared with non-users. Methods The study was based on data on reimbursed prescriptions and hospital discharge diagnoses for the 1993–2004 period, extracted from population-based healthcare databases. All patients with a first-time diagnosis of perforated peptic ulcer were identified, excluding those with previous ulcer diagnoses or antiulcer drug use. Cox regression was used to estimate 30-day mortality rate ratios for tramadol and NSAID users compared with non-users, adjusting for use of other drugs and comorbidity. Results Of 1271 patients with perforated peptic ulcers included in the study, 2.4% used tramadol only, 38.9% used NSAIDs and 7.9% used both. Thirty-day mortality was 28.7% overall and 48.4% among users of tramadol alone. Compared with the 645 patients who used neither tramadol nor NSAIDs, the adjusted mortality rate in the 30 days following hospitalization was 2.02-fold [95% confidence interval (CI) 1.17, 3.48] higher for the 31 ‘tramadol only’ users, 1.41-fold (95% CI 1.12, 1.78) higher for the 495 NSAID users and 1.32-fold (95% CI 0.89, 1.95) higher for the 100 patients who used both drugs. Conclusion Among patients hospitalized for perforated peptic ulcer, tramadol appears to increase mortality at a level comparable to NSAIDs. What is already known about this subject Use of nonsteroidal anti-inflammatory drugs (NSAIDs) is a strong risk and prognostic factor for peptic ulcer perforation, and alternative analgesics are needed for high-risk patients.Pain management guidelines propose tramadol as a treatment option for mild-to-moderate pain in patients at high risk of gastrointestinal side-effects, including peptic ulcer disease.Tramadol may mask symptoms of peptic ulcer complications, yet tramadol's effect on peptic ulcer prognosis is unknown. What this study adds In this population-based study of 1271 patients hospitalized with peptic ulcer perforation, tramadol appeared to increase mortality at least as much as NSAIDs.Among users of tramadol, alone or in combination with NSAIDs, adjusted 30-day mortality rate ratios were 2.02 [95% confidence interval (CI) 1.17, 3.48] and 1.32 (95% CI 0.89, 1.95), compared with patients who used neither tramadol nor NSAIDs. PMID:17922882

Safely Combining Abdominoplasty with Aggressive Abdominal Liposuction Based on Perforator Vessels: Technique and a Review of 300 Consecutive Cases

PubMed Central

Smith, Lane F.

2015-01-01

Background: There continues to be controversy about performing abdominoplasty concurrently with abdominal liposuction. The concern is that liposuction on the already vascularly compromised abdominal flap will lead to increased complications and flap necrosis. The central abdomen is supplied by the epigastric system. If perforator vessels from this system are spared, the blood supply to the abdomen can be spared and liposuction should be able to be safely performed on the elevated abdominal flap. The purpose of this study was to evaluate the safety of abdominoplasty with concurrent abdominal liposuction when a perforator vessel is spared. Methods: A standard abdominoplasty was performed, sparing one or two perforator vessels from the deep superior epigastric artery system. A retrospective chart review of 300 consecutive patients who underwent abdominoplasty surgery combined with concurrent abdominal liposuction was performed. Complications, total volume of abdominal liposuction, and results were reviewed. Results: The overall complication rate was 17.3 percent (52 patients). Sixteen percent (48 patients) suffered minor complications and 1.3 percent (four patients) suffered major complications. Conclusions: Abdominoplasty can be combined safely with concurrent abdominal liposuction when a perforator vessel is spared. The combination of concurrent liposuction with abdominoplasty showed no increase in complication rates when a perforator vessel was spared. The perforator vessels are located consistently in a 2-cm radius located 4 cm from the midline and 6 cm from the subcostal margin. The potential advantages of abdominoplasty with concurrent liposuction include a better postoperative cosmetic result. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV. PMID:25919250

Secondary peritonitis - evaluation of 204 cases and literature review.

PubMed

Doklestić, S K; Bajec, D D; Djukić, R V; Bumbaširević, V; Detanac, A D; Detanac, S D; Bracanović, M; Karamarković, R A

2014-06-15

Even at the beginning of the new millennium, secondary peritonitis presents a common life-threatening condition associated with high mortality and morbidity. This article comments on epidemiology, diagnosis and general principles of surgical management in patients with secondary peritonitis. The demographic data, clinical findings and surgical outcome of 204 patients who had a confirmed generalized secondary peritonitis were analyzed retrospectively. Our approach was laparotomy, surgical control of contamination, antibiotic therapy and modern intensive care support. Acid peptic disease was the most common cause of perforation peritonitis 60 (29,41%), following by the perforated appendicitis 45 ( 22,06%). The faecal peritonitis and colon perforation were found in 42 patients (20,59%). The morbidity rate was 50%; 41 (40,2%) patients had more than one complication. The morbidity rate was significantly the highest in patients with colon perforation (n=38, 90%) (Hi-square=40,1; p<0,001). The overall mortality rate in our study was 8,82%. The mortality rate was significantly the highest among the patients with mesenteric ischemia in 4 patients (66,67%), followed by colon perforation in 10 cases (23,81%), and 4(6,6%) deaths due to gastro-duodenal perforation (Hi-square=45,7; p<0,001). This study has confirmed that the clinical presentation and outcome of the secondary peritonitis depend on duration of abdominal infection, the site of perforation and the general condition of the patient. Rapid surgical source control, modern intensive care and sepsis therapy may offer the chance of decreased morbidity and mortality of the intra-abdominal infections.

Perforation following colorectal endoscopy: what happens beyond the endoscopy suite?

PubMed

Tam, Michael S; Abbas, Maher A

2013-01-01

The risk factors for perforation from colorectal endoscopy have been well studied, but little is known about clinical outcomes beyond the immediate event. To evaluate short- and long-term outcomes of iatrogenic colorectal perforation following colorectal endoscopy. Retrospective review over 16 years at a single tertiary care institution. Treatment interventions, morbidity and mortality rates, hospital length of stay, stoma closure rate, and long-term complications. Of 132,259 colorectal endoscopies, 26 patients (0.02%) had a perforation (54% males; mean age, 67 years). The rectosigmoid colon was the most common site of perforation (65%). Thirty-eight percent of the perforations were recognized at the time of procedure, 31% presented within 24 hours, and 31% presented beyond 24 hours. Operative repair was undertaken in 85% of the patients, and 15% were managed with inpatient hospital observation. Primary repair was performed in 68% (defunctioning stoma in 18%). Mean hospital length of stay was 10.1 days. The overall postoperative complications rate was 55%, and wound complications were noted in 45%. The 30-day mortality rate was 19%. No death was observed beyond the first month. American Society of Anesthesiologists physical status Classes 3 and 4 were associated with mortality (p = 0.004). Of 7 patients who received a stoma, only 2 patients (29%) had stoma reversal. Long-term complications included incisional hernia (10%) and small-bowel obstruction (5%). Perforation following colorectal endoscopy was uncommon in this study but was associated with significant morbidity and mortality. An increased risk of death was noted with higher American Society of Anesthesiologists physical status class.

Metamorphic reprocessing of a serpentinized carbonate-bearing peridotite after detachment from the mantle wedge: A P-T path constrained from textures and phase diagrams in the system CaO-MgO-Al 2O 3-SiO 2-CO 2-H 2O

NASA Astrophysics Data System (ADS)

Mposkos, E.; Baziotis, I.; Proyer, A.

2010-08-01

In the central Rhodope mountains of Greece a carbonate-bearing metaperidotite lens ˜ 200 × 500 m in size crops out as part of the high- to ultrahigh-pressure metamorphic Upper Sidironero Complex ˜ 500 m SE of the Gorgona Village, north of Xanthi town. It is composed primarily of coarse grained (3-20 mm in size) olivine and orthopyroxene, medium grained clinohumite and medium to fine grained tremolite, chlorite, dolomite, magnesite, talc, antigorite and various spinel phases. Whole-rock chemistry, mineral textures and compositions, and phase diagram calculations show that the metaperidotite was subjected to a prograde HP metamorphism, isofacial with the surrounding migmatitic gneisses, metapelites and amphibolites. The prograde character of metamorphism is demonstrated by inclusions of talc, antigorite, chlorite, dolomite, magnesite and Ti-clinohumite in ferrit-chromite, olivine, and orthopyroxene, as well as of olivine in orthopyroxene, and by the typical change in composition of zoned spinel minerals from ferrit-chromite in the core to chromian spinel at the rim. The prograde path is characterized by successive growth of amphibole, Ti-clinohumite, olivine and orthopyroxene, followed by the breakdown of Ti-clinohumite to olivine + Mg-ilmenite and of chlorite to olivine + spinel, probably during exhumation. The construction of a partial petrogenetic P- T grid in the system CaO-MgO-Al 2O 3-SiO 2-CO 2-H 2O (CMASCH) for Ca-poor ultramafic bulk compositions has proven highly useful for the reconstruction of the metamorphic evolution and a P- T path, indicating that the use of univariant reactions in mixed volatile systems is highly warranted. The P- T path is clearly constrained to pressures below 1.5-1.7 GPa by the absence of clinopyroxene. These pressures are slightly lower than those recorded in the closely associated Jurassic eclogites and much lower than those recorded in the diamond-bearing gneisses 5 km to the south in the same tectonic unit. The carbonate-bearing metaperidotite from Gorgona probably represents a fragment of the hydrated mantle wedge. This is indicated by the REE compositions which differ from those of ophiolitic peridotites and resemble those of spinel or garnet peridotites of sub-continental origin. The ultramafic slice was incorporated tectonically into the subduction channel, most likely by tectonic erosion in the Early Jurassic, but did not experience ultrahigh-pressure metamorphism like the nearby metapelites that exhumed along the same subduction channel.

Sonographic templates of newborn perforator stroke.

PubMed

Abels, Lyanne; Lequin, Maarten; Govaert, Paul

2006-07-01

Many paediatric strokes occur in the perinatal period. Improvement in neuroimaging has increased detection in newborns with neurological symptoms. To define sonographic templates of neonatal stroke in the territory of perforators of the anterior choroidal artery (AChA) and the anterior (ACA), middle (MCA) and posterior (PCA) cerebral arteries. In 24 neonates with perforator stroke, we retrospectively studied antenatal and perinatal events. Brain sonography was performed with an 8.5-MHz probe. Only hyperechoic lesions in the thalamus and/or striatum and/or centrum semiovale were included. MRI was obtained using a 1.5-T machine. We detected 28 perforator strokes in 24 infants (6 preterm): 5 MCA medial striate, 8 MCA lateral striate, 3 MCA centrum semiovale, 4 ACA Heubner's, 5 PCA thalamic arteries, 1 AChA, and 2 hypothalamic perforators. We attributed clinical seizures to stroke in two infants only. Catheter-related embolism (certain in three, possible in six others) and birth trauma (two) were probable causes. Specific conditions were found in six others. Only one infant (in nine evaluated) had an increased prothrombotic risk (fII mutation). In describing the lesions, we focused on the templates of infarction as seen in a parasagittal US sweep. Infarcts were confirmed by MRI in 21 patients. Our study showed that infarct topography can be evaluated reliably with brain sonography. This is important given the asymptomatic character of most lesions.

Acquired perforating dermatosis in a patient with chronic renal failure.

PubMed

Fernandes, Karen de Almeida Pinto; Lima, Lourenço de Azevedo; Guedes, Juliana Chaves Ruiz; Lima, Ricardo Barbosa; D'Acri, Antônio Macedo; Martins, Carlos José

2016-01-01

Perforating dermatoses are a group of skin diseases characterized by transepidermal elimination of dermal material. The disease is divided into two groups: the primary group and the secondary group. The classical or primary perforating dermatoses are subdivided into four types according to the eliminated dermal materials: Kyrle disease, perforating reactive collagenosis, elastosis perforans serpiginosa, and perforating folliculitis. The secondary form is known as acquired perforating dermatosis. The term was proposed in 1989 by Rapini to designate the perforating dermatoses affecting adult patients with systemic disease, regardless of the dermal materials eliminated. This report describes a case of the disease with elimination of collagen and elastic fibers in a patient with chronic renal failure.

Lumbar artery perforators: an anatomical study based on computed tomographic angiography imaging.

PubMed

Sommeling, Casper Emile; Colebunders, Britt; Pardon, Heleen E; Stillaert, Filip B; Blondeel, Phillip N; van Landuyt, Koenraad

2017-08-01

The free lumbar artery perforator flap has recently been introduced as a potentially valuable option for autologous breast reconstruction in a subset of patients. Up to date, few anatomical studies, exploring the lumbar region as a donor site for perforator- based flaps, have been conducted. An anatomical study of the position of the dominant lumbar artery perforator was performed, using the preoperative computed tomographic angiography images of 24 autologous breast reconstruction patients. In total, 61 dominant perforators were determined, 28 on the left and 33 on the right side. A radiologist defined the position of the perforator as coordinates in an xy-grid. Dominant perforators were shown to originate from the lumbar arteries at the level of lumbar vertebrae three or four. Remarkably, approximately 85% of these lumbar artery perforators enter the skin at 7-10 cm lateral from the midline (mean left 8.6 cm, right 8.2 cm). This study concludes a rather constant position of the dominant perforator. Therefore, preoperative-computed tomographic angiography is not always essential to find this perforator and Doppler ultrasound could be considered as an alternative, thereby carefully assessing all advantages and disadvantages inherent to either of these imaging methods.

Spectrum of perforation peritonitis in India--review of 504 consecutive cases.

PubMed

Jhobta, Rajender Singh; Attri, Ashok Kumar; Kaushik, Robin; Sharma, Rajeev; Jhobta, Anupam

2006-09-05

Perforation peritonitis is the most common surgical emergency in India. The spectrum of etiology of perforation in Tropical countries continues to be different from its Western counterpart. The objective of the study was to highlight the spectrum of perforation peritonitis as encountered by us at Government Medical College and Hospital (GMCH), Chandigarh. Five hundred and four consecutive cases of perforation peritonitis over a period of five years were reviewed in terms of clinical presentation, operative findings and postoperative course retrospectively at GMCH, Chandigarh. The most common cause of perforation in our series was perforated duodenal ulcer (289 cases) followed by appendicitis (59 cases), gastrointestinal perforation due to blunt trauma abdomen (45 cases), typhoid fever (41 cases) and tuberculosis (20 cases). Despite delay in seeking medical treatment (53%), the overall mortality (10%) was favourably comparable with other published series though the overall morbidity (50%) was unusually high. In contrast to western literature, where lower gastrointestinal tract perforations predominate, upper gastrointestinal tract perforations constitute the majority of cases in India. The increasing incidence of post-traumatic gastro-enteric injuries may be due to an increase in high speed motor vehicle accidents which warrant early recognition and prompt treatment to avoid serious complications and death.

Bladder perforations in children.

PubMed

Bakal, U; Sarac, M; Tartar, T; Ersoz, F; Kazez, A

2015-01-01

Bladder perforations in children occur due to several different reasons. In this clinical series study, we focused on bladder perforations due to the pelvic injury, and our aim also was to create awareness for a rare type of bladder injuries. This was a retrospective study of the patients who were treated in our clinic for bladder perforation between 2006 and 2011. We reviewed the documents of childhood bladder perforations, and demographic and clinical characteristics of the patients were obtained. No statistical analyses were used because of the limited number of cases. There were ten patients who suffered from bladder perforation in 5-year period; 5 were male, and 5 were female. The mean age of the patients was 4.35 years. Four patients (40%) experienced iatrogenic perforation and six patients (60%) experienced perforation due to the accident. Common symptoms were hematuria, abdominal tenderness, and inability to urinate. Three patients were diagnosed via emergency laparotomy, without any radiological examinations performed before surgery. Four patients suffered from the intraperitoneal perforation, three patients suffered from extraperitoneal injury and three of them both of intraperitoneal and extraperitoneal injuries. Mean recovery time for patients was 15 days. One patient developed a urinary tract infection and one newborn died due to accompanying morbidities. Nine patients were discharged from the hospital. If the patients had a pelvic injury, surgeons must pay attention for the bladder perforation. Isolated bladder perforations are rare, and they are generally associated with iatrogenic injuries. Clinicians should pay attention to findings such as anuria, inability to insert a urinary catheter, and free fluid in the abdomen in order to diagnose the bladder perforation in newborns. Novice surgeons should pay more attention to avoid causing iatrogenic bladder perforation during inguinal hernia repair.

Optimal contact forces to minimize cardiac perforations before, during, and/or after radiofrequency or cryothermal ablations.

PubMed

Quallich, Stephen G; Van Heel, Michael; Iaizzo, Paul A

2015-02-01

Catheter perforations remain a major clinical concern during ablation procedures for treatment of atrial arrhythmias and may lead to life-threatening cardiac tamponade. Radiofrequency (RF) ablation alters the biomechanical properties of cardiac tissue, ultimately allowing for perforation to occur more readily. Studies on the effects of cryoablation on perforation force as well as studies defining the perforation force of human tissue are limited. The purpose of this study was to investigate the required force to elicit perforation of cardiac atrial tissue after or during ablation procedures. Effects of RF or cryothermal ablations on catheter perforation forces for both swine (n = 83 animals, 530 treatments) and human (n = 8 specimens, 136 treatments) cardiac tissue were investigated. Overall average forces resulting in perforation of healthy unablated tissue were 406g ± 170g for swine and 591g ± 240g for humans. Post-RF ablation applications considerably reduced these forces to 246g ± 118g for swine and 362 ± 185g for humans (P <.001). Treatments with cryoablation did not significantly alter forces required to induce perforations. Decreasing catheter sizes resulted in a reduction in forces required to perforate the atrial wall (P <.001). Catheter perforations occurred over an array of contact forces with a minimum of 38g being observed. The swine model likely underestimates the required perforation forces relative to those of human tissues. We provide novel insights related to the comparative effects of RF and cryothermal ablations on the potential for inducing undesired punctures, with RF ablation reducing perforation force significantly. These data are insightful for physicians performing ablation procedures as well as for medical device designers. Copyright © 2015 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Legacy Effect of Coronary Perforation Complicating Percutaneous Coronary Intervention for Chronic Total Occlusive Disease: An Analysis of 26 807 Cases From the British Cardiovascular Intervention Society Database.

PubMed

Kinnaird, Tim; Anderson, Richard; Ossei-Gerning, Nicholas; Cockburn, James; Sirker, Alex; Ludman, Peter; deBelder, Mark; Walsh, Simon; Smith, Elliot; Hanratty, Colm; Spratt, James; Strange, Julian; Hildick-Smith, David; Mamas, Mamas A

2017-05-01

Coronary perforation (CP) during chronic total occlusion percutaneous coronary intervention for stable angina (CTO-PCI) is a rare but serious event. The evidence base is limited, and the long-term effects are unclear. Using a national PCI database, the incidence, predictors, and outcomes of CP during CTO-PCI were defined. Data analyzed from the British Cardiovascular Intervention Society data set on all CTO-PCI procedures performed in England and Wales between 2006 and 2013. Multivariate logistic regressions and propensity scores were used to identify predictors of CP and its association with outcomes. A total of 376 CP were recorded from 26 807 CTO-PCI interventions (incidence of 1.40%) with an increase in frequency during the study period ( P =0.012). Patient-related factors associated with an increased risk of CP were age and female sex. Procedural factors indicative of complex CTO intervention strongly related to an increased risk of CP with a close relationship between the number of complex strategies used and CP evident ( P =0.008 for trend). Tamponade occurred in 16.6% and emergency surgery in 3.4% of cases. Adverse outcomes were frequent in those patients with perforation including bleeding, transfusion, myocardial infarction, and death. A legacy effect of perforation on mortality was evident, with an odds ratio for 12-month mortality of 1.60 for perforation survivors compared with matched nonperforation survivors without a CP ( P <0.0001). Many of the factors associated with an increased risk of CP were related to CTO complexity. Perforation was associated with adverse outcomes, with a legacy effect on later mortality after CP also observed. © 2017 American Heart Association, Inc.

Suprascarpal fat pad thickness may predict venous drainage patterns in abdominal wall flaps.

PubMed

Bast, John; Pitcher, Austin A; Small, Kevin; Otterburn, David M

2016-02-01

Abdominal wall flaps are routinely used in reconstructive procedures. In some patients inadequate venous drainage from the deep vein may cause fat necrosis or flap failure. Occasionally the superficial inferior epigastric vessels (SIEV) are of sufficient size to allow for microvascular revascularization. This study looked at the ratio of the sub- and suprascarpal fat layers, the number of deep system perforators, and SIEV diameter to determine any correlation of the fat topography and SIEV. 50 abdominal/pelvic CT angiograms (100 hemiabdomens) were examined in women aged 34-70 years for number of perforators, SIEV diameter, and fat pad thickness above and below Scarpa's fascia. Data was analyzed using multivariate model. The average suprascarpal and subscarpal layers were 18.6 ± 11.5 mm and 6.2 ± 7.2 mm thick, respectively. The average SIEV diameter was 2.06 ± 0.81 mm and the average number of perforators was 2.09 ± 1.03 per hemiabdomen. Hemiabdomens with suprascarpal thickness>23 mm had greater SIEV diameter [2.69 mm vs. 1.8 mm (P < 0.0001)] The fat layer thickness did not correlate with the number of perforators. Neither subscarpal fat thickness nor suprascarpal-to-subscarpal fat layer thickness correlated significantly with SIEV caliber or number of perforators in multivariate model. Suprascarpal fat pad thicker than 23 mm had larger SIEVs irrespective of the number of deep system perforators. This may indicate a cohort of patients at risk of venous congestion from poor venous drainage if only the deep system is revascularized. We recommend harvesting the SIEV in patients with suprascarpal fat pad >23 mm to aid in superficial drainage. © 2015 Wiley Periodicals, Inc.

Hard palate perforation: an unusual finding in paracoccidioidomycosis.

PubMed

Castro, L G; Müller, A P; Mimura, M A; Migliari, D A

2001-04-01

A 36-year-old black man presented to his dermatologist in May 1996 complaining of mucosal lesions in the mouth, as well as perforation of the hard palate. The lesions had started approximately 7 months before and had worsened gradually. Other complaints included odynophagia, dysphagia, mild dyspnea, and dry cough. The patient was in good general health, but reported a 3 kg weight loss over the previous semester. The hard and soft palate presented erythematous ulcers with a finely granulated base and irregular, but clearly defined margins. A perforation (diameter, 0.5 cm) of the hard palate was seen in the center of the ulcerated region (Fig. 1). Direct examination of 10% KOH cleared specimens showed typical double-walled, multiple budding yeast structures. Paracoccidioidomycosis (PCM) serologic reactions tested positive for double immunodiffusion (DI), complement fixation (CF) 1 : 256 and counterimmunoelectrophoresis (CIE) 1 : 128. Hematoxylin and eosin-stained sections of oral lesions showed an ulcer covered by a fibrous leukocytic crust, with a lymphoplasmacytic infiltrate, as well as multinuclear giant cells containing round bodies with a double membrane. Gomori-Grocott staining showed budding and blastoconidia suggestive of PCM. Lung computed tomography (CT) exhibited findings consistent with pulmonary PCM. Diagnosis of the chronic multifocal form of PCM with oral and pulmonary manifestations was established. Drug therapy was initiated with ketoconazole (KCZ) 200 mg twice daily, which led to clinical cure in approximately 2 months. Serum antibody values rose 30 days after institution of therapy (CIE 1 : 256; CF 1 : 512), peaking at day 60 (CIE 1 : 1024; CF 1 : 1024). Three months later the daily dose was reduced to 200 mg and titers declined slowly. The diameter of the perforation remained unchanged (Fig. 2). The hard palate perforation was corrected with a palatoplasty 27 months after initiation of drug therapy (Fig. 3). KCZ was discontinued when serologic cure was achieved after 34 months of treatment (DI weakly positive; CIE 1 : 8; CF not measurable). The patient was discharged 46 months after the first visit.

Pharyngoesophageal perforation 3 years after anterior cervical spine surgery: a rare case report and literature review.

PubMed

Yin, Dan-Hui; Yang, Xin-Ming; Huang, Qi; Yang, Mi; Tang, Qin-Lai; Wang, Shu-Hui; Wang, Shuang; Liu, Jia-Jia; Yang, Tao; Li, Shi-Sheng

2015-08-01

Pharyngoesophageal perforation after anterior cervical spine surgery is rare and the delayed cases were more rarely reported but potentially life-threatening. We report a case of pharyngoesophageal perforation 3 years after anterior cervical spine surgery. The patient presented with dysphagia, fever, left cervical mass and developing dyspnea 3 years after cervical spine surgery for trauma. After careful examinations, he underwent an emergency tracheostomy, neck exploration, hardware removal, abscess drainage and infected tissue debridement. 14 days after surgery, CT of the neck with oral contrast demonstrated no contrast extravasation from the esophagus. Upon review of literature, only 14 cases of pharyngoesophageal perforation more than 1 year after anterior cervical spine surgery were found. We discussed possible etiology, diagnosis and management and concluded that in cases of dysphagia, dyspnea, cervical pain, swelling and edema of the cervical area even long time after anterior cervical spine surgery, potential pharyngoesophageal damage should be considered.

Perforated peptic ulcer in an adolescent girl.

PubMed

Schwartz, Shepard; Edden, Yair; Orkin, Boris; Erlichman, Matityahu

2012-07-01

A perforated peptic ulcer in a child is a rare entity. Severe abdominal pain in an ill-appearing child with a rigid abdomen and possibly with signs of shock is the typical presenting feature of this life-threatening complication of peptic ulcer disease. We present a case of a 14.5-year-old adolescent girl who developed abdominal and shoulder pain that resolved after 1 day. She was then completely well for 2 days until the abdominal and shoulder pain recurred. On examination, she appeared well, but in pain. A chest radiograph revealed a large pneumoperitoneum. She underwent emergent laparoscopic omental patch repair of a perforated ulcer on the anterior wall of her stomach. Result of a urea breath test to detect Helicobacter pylori was negative. The differential diagnosis of pneumoperitoneum in children is discussed, as are childhood perforated peptic ulcer in general, and the unique clinical features present in this case in particular.

A Novel Augmented Reality-Based Navigation System in Perforator Flap Transplantation - A Feasibility Study.

PubMed

Jiang, Taoran; Zhu, Ming; Zan, Tao; Gu, Bin; Li, Qingfeng

2017-08-01

In perforator flap transplantation, dissection of the perforator is an important but difficult procedure because of the high variability in vascular anatomy. Preoperative imaging techniques could provide substantial information about vascular anatomy; however, it cannot provide direct guidance for surgeons during the operation. In this study, a navigation system (NS) was established to overlie a vascular map on surgical sites to further provide a direct guide for perforator flap transplantation. The NS was established based on computed tomographic angiography and augmented reality techniques. A virtual vascular map was reconstructed according to computed tomographic angiography data and projected onto real patient images using ARToolKit software. Additionally, a screw-fixation marker holder was created to facilitate registration. With the use of a tracking and display system, we conducted the NS on an animal model and measured the system error on a rapid prototyping model. The NS assistance allowed for correct identification, as well as a safe and precise dissection of the perforator. The mean value of the system error was determined to be 3.474 ± 1.546 mm. Augmented reality-based NS can provide precise navigation information by directly displaying a 3-dimensional individual anatomical virtual model onto the operative field in real time. It will allow rapid identification and safe dissection of a perforator in free flap transplantation surgery.

Non-operative management of diverticular perforation in a patient with suspected Ehlers–Danlos syndrome☆

PubMed Central

Casey, M.C.; Robertson, I.; Waters, P.S.; Hanaghan, J.; Khan, W.; Barry, K.

2014-01-01

INTRODUCTION No consensus exists regarding definitive management of colonic perforation in Ehlers–Danlos syndrome (EDS), with various authors advocating different operative techniques. Spontaneous colonic perforation is a recognised complication of vascular-type EDS (type IV), with many reported cases in the literature. No such cases have been reported concerning classical-type EDS (type I/II). PRESENTATION OF CASE A 55-year-old male with a family history of EDS presented with acute lower abdominal pain and signs of localised peritonitis. Following resuscitation, computerised tomography identified perforation of a sigmoid diverticulum with localised intraperitoneal air. Considering the potential complications associated with laparotomy in a patient with EDS, a trial of conservative management was undertaken including image-guided drainage of a mesenteric abscess. Intensive care monitoring, nutritional support and intravenous antibiotics also facilitated successful non-operative management. Following discharge, molecular studies confirmed COL5A1 mutation, and a diagnosis of classical Ehlers–Danlos syndrome was established. DISCUSSION This is the first reported case of successful conservative management of colonic diverticular perforation in a patient with classical Ehlers–Danlos syndrome. CONCLUSION EDS is highly significant in the surgical context, with the causative genetic factors serving to further complicate the course of surgical intervention. In the absence of consensus regarding best surgical management, due consideration should be given to non-operative management of benign colonic perforation. PMID:24534685

Incidence of glove failure during orthopedic operations and the protective effect of double gloves.

PubMed

Thanni, Lateef O A; Yinusa, W

2003-12-01

To determine the usefulness of double gloves in protecting against the exposure of surgical team members' hands to blood. Five-hundred-ninety-six gloves were studied during 71 orthopedic operations using the water-loading test (filling a glove with water and occluding its cuff tightly to identify leaking points). In all, 73 glove perforations occurred, but only nine resulted in exposure to blood (blood touching the skin). The incidence of glove perforation was 12% (73/596), and overall exposure (blood touching the skin) per operation was 13% (9/71). The latter would have been 87% (62/71) but for the use of double gloves. Sixteen percent of the perforations in double gloves were in the inner gloves, while 84% were in the outer gloves. Exposure of surgeons was reduced from 54% to 10%, first assistants from 27% to 3%, and second assistants from 7% to 0 (p < 0.02, df = 2) by double-gloving. Significantly more perforations occurred during operations on bone, compared with soft tissue operations, p < 0.0001, RR = 4 (95% CL 1.87-8.55). The most common sites of glove perforation were the index finger (47%), thumb, and the palm region: 14% each. More glove perforations occurred in nondominant hands. Double-gloving offers additional protection to surgeons and assistants by preventing hand exposure to blood intraoperatively.

Repeated Duodenal Stump Perforation Using a Stapling Device Following Subtotal Gastrectomy With Roux-en-Y Reconstruction for Advanced Gastric Cancer: Lessons From a Rare Case.

PubMed

Furihata, Tadashi; Furihata, Makoto; Satoh, Naoki; Kosaka, Masato; Ishikawa, Kunibumi; Kubota, Keiichi

2015-04-01

Closure of the duodenal stump using a stapling device is commonly applied in Roux-en-Y reconstruction after gastrectomy. However, serious and possibly fatal duodenal stump perforation can develop in extremely rare cases. We describe a case of subtotal gastrectomy with Roux-en-Y reconstruction followed by repeated duodenal stump perforations. A 79-year-old man with a long history of diabetes and hypertension was admitted to our institution with epigastralgia and right hypochondralgia. Computed tomography and an upper gastrointestinal imaging series revealed remarkable wall thickening of the gastric antrum and corpus. Upper endoscopy also showed a giant ulcerative lesion in the same area. The lesion was confirmed by histology to be poorly differentiated adenocarcinoma. The patient underwent open subtotal gastrectomy with Roux-en-Y reconstruction. However, duodenal stump perforation occurred repeatedly on postoperative days 1, 3, and 19, which caused peritonitis. The patient was kept alive through duodenal stump repair, an additional resection using a stapling device, and repeated drainage treatments; but he suffered considerable morbidity due to these complications. We report a case of a life-threatening duodenal stump perforation after subtotal gastrectomy, highlighting lessons learned from the profile and clinical course. Abdominal surgeons should be aware of the possibility of this serious complication of duodenal stump perforation, and be able to perform immediate interventions, including life-saving reoperation.

California Sun Glint

Atmospheric Science Data Center

2014-05-15

... path 41. MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Science Mission Directorate, ... Text acknowledgment: Clare Averill (Raytheon ITSS / Jet Propulsion Laboratory), Mike Garay (Jet Propulsion Laboratory) and Dominic ...

Complex Clouds

Atmospheric Science Data Center

2013-04-16

... article title:  Multi-layer Clouds Over the South Indian Ocean     View Larger Image ... System-2 path 155. MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Science Mission ...

Duodenal perforation: an unusual complication of sickle cell anemia.

PubMed

Acıpayam, Can; Aldıç, Güliz; Akçora, Bülent; Çelikkaya, Mehmet Emin; Aşkar, Hasan; Dorum, Bayram Ali

2014-01-01

Duodenal perforation in childhood is a rare condition with a high mortality rate if not treated surgically. Primary gastroduodenal perforation is frequently associated with peptic ulcer and exhibits a positive family history. Helicobacter pylorus is the most significant agent. Secondary gastroduodenal perforation may be a finding of specific diseases, such as Crohn disease, or more rarely may be associated with diseases such as cystic fibrosis or sickle cell anemia. A 14-year-old boy presented with abdominal and back pain. The patient was operated on for acute abdomen and diagnosed with duodenal perforation. Helicobacter pylorus was negative. There was no risk factor to account for duodenal perforation other than sickle cell anemia. Surgical intervention was successful and without significant sequelae. Duodenal perforation is a rare entity described in patients with sickle cell anemia. To our knowledge, this is the first report of duodenal perforation in a patient sickle cell anemia.

Duodenal perforation: an unusual complication of sickle cell anemia

PubMed Central

Acıpayam, Can; Aldıç, Güliz; Akçora, Bülent; Çelikkaya, Mehmet Emin; Aşkar, Hasan; Dorum, Bayram Ali

2014-01-01

Duodenal perforation in childhood is a rare condition with a high mortality rate if not treated surgically. Primary gastroduodenal perforation is frequently associated with peptic ulcer and exhibits a positive family history. Helicobacter pylorus is the most significant agent. Secondary gastroduodenal perforation may be a finding of specific diseases, such as Crohn disease, or more rarely may be associated with diseases such as cystic fibrosis or sickle cell anemia. A 14-year-old boy presented with abdominal and back pain. The patient was operated on for acute abdomen and diagnosed with duodenal perforation. Helicobacter pylorus was negative. There was no risk factor to account for duodenal perforation other than sickle cell anemia. Surgical intervention was successful and without significant sequelae. Duodenal perforation is a rare entity described in patients with sickle cell anemia. To our knowledge, this is the first report of duodenal perforation in a patient sickle cell anemia. PMID:25422692

Fidelity of the Sr/Ca proxy in recording ocean temperature in the western Atlantic coral Siderastrea siderea

USGS Publications Warehouse

Kuffner, Ilsa B.; Roberts, Kelsey E.; Flannery, Jennifer A.; Morrison, Jennifer M.; Richey, Julie

2017-01-01

Massive corals provide a useful archive of environmental variability, but careful testing of geochemical proxies in corals is necessary to validate the relationship between each proxy and environmental parameter throughout the full range of conditions experienced by the recording organisms. Here we use samples from a coral-growth study to test the hypothesis that Sr/Ca in the coral Siderastrea siderea accurately records sea-surface temperature (SST) in the subtropics (Florida, USA) along 350 km of reef tract. We test calcification rate, measured via buoyant weight, and linear extension (LE) rate, estimated with Alizarin Red-S staining, as predictors of variance in the Sr/Ca records of 39 individual S. siderea corals grown at four outer-reef locations next to in-situ temperature loggers during two, year-long periods. We found that corals with calcification rates < 1.7 mg cm−2 d−1 or < 1.7 mm yr−1 LE returned spuriously high Sr/Ca values, leading to a cold-bias in Sr/Ca-based SST estimates. The threshold-type response curves suggest that extension rate can be used as a quality-control indicator during sample and drill-path selection when using long cores for SST paleoreconstruction. For our corals that passed this quality control step, the Sr/Ca-SST proxy performed well in estimating mean annual temperature across three sites spanning 350 km of the Florida reef tract. However, there was some evidence that extreme temperature stress in 2010 (cold snap) and 2011 (SST above coral-bleaching threshold) may have caused the corals not to record the temperature extremes. Known stress events could be avoided during modern calibrations of paleoproxies.

Testing the fidelity of the Sr/Ca proxy in recording ocean temperature in a western Atlantic coral

NASA Astrophysics Data System (ADS)

Kuffner, I. B.; Roberts, K.; Flannery, J. A.; Richey, J. N.; Morrison, J. M.

2017-12-01

Massive corals provide a useful archive of environmental variability, but careful testing of geochemical proxies in corals is necessary to validate the relationship between each proxy and environmental parameter throughout the full range of conditions experienced by the recording organisms. Here we use samples from a field-based coral-growth study to test the hypothesis that Sr/Ca in the coral Siderastrea siderea accurately records sea-surface temperature (SST) in the subtropics (Florida, USA) along 350 km of reef tract. We test calcification rate, measured via buoyant weight, and linear extension (LE) rate, estimated with Alizarin Red-S staining, as predictors of variance in the Sr/Ca records of 39 individual S. siderea corals grown at four outer-reef locations next to in-situ temperature loggers during two, year-long periods. We found that corals with calcification rates less than 1.7 mg cm-2 d-1 or LE rates less than 1.7 mm yr-1 returned spuriously high Sr/Ca values, leading to a cold bias in Sr/Ca-based SST estimates. The threshold-type response curves suggest that LE rate can be used as a quality-control indicator during sample and microdrill-path selection when using long cores for SST paleoreconstruction. For our corals that passed this quality control step, the Sr/Ca-SST proxy performed well in estimating mean annual SST across three sites spanning 350 km of the Florida reef tract. However, there was some evidence that extreme temperature stress in 2010 (cold snap) and 2011 (SST above coral-bleaching threshold) may have caused the corals not to record the temperature extremes. Known stress events could be avoided during modern calibrations of paleoproxies.

Immediate detection of endoscopic retrograde cholangiopancreatography-related periampullary perforation: Fluoroscopy or endoscopy?

PubMed Central

Motomura, Yasuaki; Akahoshi, Kazuya; Gibo, Junya; Kanayama, Kenji; Fukuda, Shinichiro; Hamada, Shouhei; Otsuka, Yoshihiro; Kubokawa, Masaru; Kajiyama, Kiyoshi; Nakamura, Kazuhiko

2014-01-01

AIM: To investigate the causes and intraoperative detection of endoscopic retrograde cholangiopancreatography (ERCP)-related perforations to support immediate or early diagnosis. METHODS: Consecutive patients who underwent ERCP procedures at our hospital between January 2008 and June 2013 were retrospectively enrolled in the study (n = 2674). All procedures had been carried out using digital fluoroscopic assistance with the patient under conscious sedation. For patients showing alterations in the gastrointestinal anatomy, a short-type double balloon enteroscope had been applied. Cases of perforation had been identified by the presence of air in or leakage of contrast medium into the retroperitoneal space, or upon endoscopic detection of an abdominal cavity related to the perforated lumen. For patients with ERCP-related perforations, the data on medical history, endoscopic findings, radiologic findings, diagnostic methods, management, and clinical outcomes were used for descriptive analysis. RESULTS: Of the 2674 ERCP procedures performed during the 71-mo study period, only six (0.22%) resulted in perforations (male/female, 2/4; median age: 84 years; age range: 57-97 years). The cases included an endoscope-related duodenal perforation, two periampullary perforations related to endoscopic sphincterotomy, two periampullary perforations related to endoscopic papillary balloon dilation, and a periampullary or bile duct perforation secondary to endoscopic instrument trauma. No cases of guidewire-related perforation occurred. The video endoscope system employed in all procedures was only able to immediately detect the endoscope-related perforation; the other five perforation cases were all detected by subsequent digital fluoroscope applied intraoperatively (at a median post-ERCP intervention time of 15 min). Three out of the six total perforation cases, including the single case of endoscope-related duodenal injury, were surgically treated; the remaining three cases were treated with conservative management, including trans-arterial embolization to control the bleeding in one of the cases. All patients recovered without further incident. CONCLUSION: ERCP-related perforations may be difficult to diagnose by video endoscope and digital fluoroscope detection of retroperitoneal free air or contrast medium leakage can facilitate diagnosis. PMID:25400465

The Heidelberg Appendicitis Score Predicts Perforated Appendicitis in Children.

PubMed

Boettcher, Michael; Günther, Patrick; Breil, Thomas

2017-10-01

In the future, surgical management of pediatric appendicitis might become limited to nonperforating appendicitis. Thus, it becomes increasingly important to differentiate advanced from simple appendicitis and to predict perforated appendicitis among a group of children with right-sided abdominal pain, which was the aim of this study. An institutionally approved, single-center retrospective analysis of all patients with appendectomy from January 2009 to December 2010 was conducted. All diagnostic aspects were evaluated to identify predictors and differentiators of perforated appendicitis. In 2 years, 157 children suffered from appendicitis. Perforation occurred in 47 (29.9%) of the patients. C-reactive protein (CRP) levels higher than 20 mg/dL ( P = .037) and free abdominal fluid on ultrasonography ( P = .031) are the most important features to differentiate perforated from simple appendicitis. Moreover, all children with perforation had a positive Heidelberg Appendicitis Score (HAS). A negative HAS excludes perforation in all cases (negative predictive value = 100%). Perforated appendicitis can be ruled out by the HAS. In a cohort with right-sided abdominal pain, perforation should be considered in children with high CRP levels and free fluids or abscess formation on ultrasound.

Reliable harvest of a dorsal scapular artery perforator flap by augmenting its perfusion.

PubMed

Kim, So-Young; Lee, Kyeong-Tae; Mun, Goo-Hyun

2016-02-01

Despite confirmation of a reliable perforasome in the dorsal scapular artery in an anatomic study, a true perforator flap has not been recommended in previous clinical studies because of concerns regarding insufficient perfusion in the distal region. In this report, we present two cases of reconstruction for occipital defects caused by tumor extirpation using pedicled dorsal scapular artery perforator flaps without a muscle component. To secure the perfusion of the dorsal scapular artery perforator flap, inclusion of an additional perforator was attempted for perfusion augmentation. The second dorsal scapular artery perforator was harvested in one case. In an additional case, the sixth dorsal intercostal artery perforator with a branch that directly connected with the dorsal scapular artery within the trapezius muscle was additionally harvested. The flaps survived without any perfusion-related complications, including tip necrosis, and no donor site morbidities were observed. We suggest that a perfusion augmented dorsal scapular artery perforator flap by harvesting multiple perforators could be a safe and useful alternative for reconstructive surgery of head and neck defects. © 2014 Wiley Periodicals, Inc.

Tunneling barrier in nanoparticle junctions of La2/3(Ca,Sr)1/3MnO3: Nonlinear current-voltage characteristics

NASA Astrophysics Data System (ADS)

Niebieskikwiat, D.; Sánchez, R. D.; Lamas, D. G.; Caneiro, A.; Hueso, L. E.; Rivas, J.

2003-05-01

We study the nonlinear current-voltage (I-V) characteristics and analyze the voltage-dependent tunneling conductance in nanoparticles of La2/3A1/3MnO3 (A=Ca, Sr). The powders were prepared by different wet-chemical routes and low calcination temperatures were used to obtain an average particle size D≈30 nm. The data are comprehensively explained in terms of the tunneling picture, which allows one to estimate the height of the grain boundary insulating barrier (φ) for each sample. For constant D, our results show that the sample preparation route is mainly responsible for the value of φ in nanoparticles, while the Coulomb gap in the Coulomb blockade regime is ˜3 times higher for Sr- than for Ca-doping. We also show that a small fraction of the barriers contribute to the nonlinear transport, and the current is mainly carried through low-resistive percolated paths. In addition, despite the different barrier strengths, the low-field magnetoresistance (LFMR) is similar for all samples, implying that φ is not the fundamental parameter determining the LFMR.

Vascular anatomy of the medial sural artery perforator flap: a new classification system of intra-muscular branching patterns.

PubMed

Dusseldorp, Joseph R; Pham, Quy J; Ngo, Quan; Gianoutsos, Mark; Moradi, Pouria

2014-09-01

The medial sural artery perforator (MSAP) flap is a versatile fasciocutaneous flap. The main difficulty encountered when raising the MSAP flap is in obtaining adequate pedicle length during intra-muscular dissection. The objective of this study was to determine the pattern of intra-muscular course of the MSAP flap pedicle. 14 cadaveric specimens were dissected and CT angiograms of 84 legs were examined. The intra-muscular branching pattern and depths of the medial sural artery branches were analyzed. The number of perforators, position of the dominant perforator and both intra-muscular and total pedicle length were also recorded and compared to existing anatomical data. Three types of arterial branching pattern were identified within the medial gastrocnemius, demonstrating one (31%), two (59%) or three or more (10%) main branches. A dominant perforator from the medial sural artery was present in 92% of anatomical specimens (13/14). Vertically, the location of the perforator from the popliteal crease was on average 13 cm (±2 cm). Transversely, the perforator originated 2.5 cm (±1 cm) from the posterior midline. Using CT angiography it was possible in 10 consecutive patients to identify a more superficial intra-muscular branch and determine the leg with the optimal branching pattern type for flap harvest. This study is the first to describe the variability of the intra-muscular arterial anatomy of the medial head of gastrocnemius muscle. Surgeons utilizing the MSAP flap option should be aware of the possible branching pattern types and consequently the differing perforator distribution and depths of intra-muscular branches. Routine use of pre-operative CT angiogram may help determine which leg has the most favorable branching pattern type and intra-muscular course for flap harvest. Copyright © 2014 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

[Peritonitis following gastroduodenal ulcer perforation disease in children: report of 4 cases].

PubMed

Ndour, O; Bansouda, J; Fall, A F; Alumeti, D M; Diouf, C; Ngom, G; Ndoye, M

2012-10-01

Peritonitis due to gastroduodenal ulcer perforation disease is a rare entity in pediatric surgery. In Senegal, no study has been dedicated to ulcer complications in children. The aim of this study was to describe the epidemiology, diagnosis, and treatment of perforated peptic ulcer in patients less than 15 years old. This retrospective study was conducted in the Surgical Emergencies and Paediatric Surgery Department at Aristide Le Dantec University Hospital Center in Dakar, Senegal, during a period of 11 years (January 1999 to December 2010). We found 4 children who presented perforated gastroduodenal ulcer: 3 females and 1 male. The average age of these patients was 9 years (range, 7-14 years). No family history was found. We noted 3 cases of perforated duodenal ulcer and one perforated gastric ulcer. The clinical diagnosis was suspected based on a peritoneal irritation syndrome. A plain x-ray of the abdomen was taken in all patients, which objectified a pneumoperitoneum image in 3 cases. The leukocytosis was constant. Treatment in all patients consisted on pre-, intra-, and postoperative intensive care, supra- and infraumbilical midline laparotomy, which allowed us to perform a debridement-suture of the gap followed by epiploplasty and extensive washing with lukewarm physiologic serum. Adjuvant therapy based on anti-ulcer and antibiotic therapy was initiated. Bacteriological examination of peritoneal fluid isolated a polymicrobial flora. Helicobacter pylori was not isolated. Histological examination of the biopsied perforation edges showed a benign ulcer in all cases. The follow-up endoscopy was performed 4 weeks after surgery and showed cicatrization of the ulcer in all patients. After a mean of 2 years, no recurrence was noted. The gastric or duodenal ulcer in children is rare. It is often discovered at the stage of perforation, a complication for which the essential treatment is surgery. Routine screening would certainly help to reduce the risk of this complication. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

The Peptic Ulcer Perforation (PULP) score: a predictor of mortality following peptic ulcer perforation. A cohort study.

PubMed

Møller, M H; Engebjerg, M C; Adamsen, S; Bendix, J; Thomsen, R W

2012-05-01

Accurate and early identification of high-risk surgical patients with perforated peptic ulcer (PPU) is important for triage and risk stratification. The objective of the present study was to develop a new and improved clinical rule to predict mortality in patients following surgical treatment for PPU. nationwide cohort study based on prospectively collected data. thirty-five hospitals in Denmark. a total of 2668 patients surgically treated for gastric or duodenal PPU between 1 February 2003 and 31 August 2009. 30-day mortality. We derived a new clinical prediction rule for 30-day mortality and evaluated and compared its prognostic performance with the American Society of Anaesthesiologists (ASA) and Boey scores. A total of 708 patients (27%) died within 30 days of surgery. The Peptic Ulcer Perforation (PULP) score - comprised eight variables with an adjusted odds ratio of more than 1.28: 1) age > 65 years, 2) active malignant disease or AIDS, 3) liver cirrhosis, 4) steroid use, 5) time from perforation to admission > 24 h, 6) pre-operative shock, 7) serum creatinine > 130 μM, and 8) the four levels of the ASA score (from 2 to 5). The score predicted mortality well (area under receiver operating characteristics curve (AUC) 0.83). It performed considerably better than the Boey score (AUC 0.70) and better than the ASA score alone (AUC 0.78). The PULP score accurately predicts 30-day mortality in patients operated for PPU and can assist in risk stratification and triage. © 2011 The Authors Acta Anaesthesiologica Scandinavica © 2011 The Acta Anaesthesiologica Scandinavica Foundation.

[CLINICAL APPLICATION AND EXPERIENCE IN RECONSTRUCTION OF SOFT TISSUE DEFECTS FOLLOWING MALIGNANT TUMOR REMOVAL OF LIMBS USING PERFORATOR PROPELLER FLAPS].

PubMed

Zhu, Shan; Liu, Yuanbo; Yu, Shengji; Zang, Mengqing; Zhao, Zhenguo; Xu, Libin; Zhang, Xinxin; Chen, Bo; Ding, Qiang

2016-01-01

To explore the feasibility and technical essentials of soft tissue defect reconstruction following malignant tumor removal of limbs using perforator propeller flaps. Between July 2008 and July 2015, 19 patients with malignant limb tumor underwent defect reconstruction following tumor removal using the perforator propeller flaps. There were 13 males and 6 females with an average age of 53.4 years (range, 20-82 years). The disease duration ranged from 1 to 420 months (mean, 82 months). The tumors located at the thigh in 10 cases, at the leg in 2 cases, at the arm in 1 case, at the forearm in 1 case, around the knee in 2 cases, and around the elbow joint in 3 cases. Totally 23 flaps (from 8 cm x 3 cm to 30 cm x 13 cm in size) were used to reconstruct defects (from 4 cm x 4 cm to 24 cm x 16 cm in size). The potential source arteries included the femoral artery (n = 2), profunda femoral artery (n = 3), superficial circumflex iliac artery (n = 1), lateral circumflex femoral artery (n = 6), superior lateral genicular artery (n = 2), peroneal artery (n = 2), anterior tibial artery (n = 1), brachial artery (n = 4), and radial artery (n = 1). The remaining one was a free style perforator flap. Partial distal flap necrosis occurred in 3 cases after surgery with rotation angles of 180, 150, and 100 degrees respectively, which were reconstructed after debridement using a free-style perforator flap in 1 case and using free skin grafting in the other 2 cases. The other 20 flaps survived completely after surgery. Primary healing of incisions was obtained at the donor and recipient sites. There was no severe complication such as infection, hematoma, and total flap failure. All patients were followed up 3 months to 5 years (mean, 19 months). One patient with malignant melanoma around the elbow joint had tumor recurrence, and underwent secondary tumor resection. The appearance, texture, and color of the flaps were similar to those at the recipient site. For patients with malignant tumor of the limb, the perforator propeller flap can be an alternative option for soft tissue defect reconstruction after tumor resection, with the advantages of relatively simple operation and remaining the main vessels.

Soft J-tipped guide wire-induced cardiac perforation in a patient with right ventricular lipomatosis and wall thinning.

PubMed

Hiroshima, Yuki; Tajima, Katsushi; Shiono, Yousuke; Suzuki, Ikuko; Kohno, Kei; Kato, Yuichi; Shunji, Kawamura; Kato, Takeo

2012-01-01

Cardiac tamponade caused by perforation is a rare but potentially lethal complication of central venous catheter (CVC) insertion. We herein report a case of cardiac perforation associated with the use of a soft J-tipped guide wire. Twenty minutes after the insertion of a CVC, the patient developed unexpected cardiac arrest. An autopsy revealed 400 mL of pericardial blood. The right ventricular wall was 1 mm thick with about 10 myocyte layers, which is one-third that of the normal heart. A histological analysis revealed widespread fatty infiltration of the right ventricular wall (right ventricular lipomatosis).

Impingement thermal performance of perforated circular pin-fin heat sinks

NASA Astrophysics Data System (ADS)

Wen, Mao-Yu; Yeh, Cheng-Hsiung

2018-04-01

The study presents the experimental information on heat transfer performance of jet impingement cooling on circular pin- fin heat sinks with/without a hollow perforated base plate. Smoke flow visualization is also used to investigate the behavior of the complicated flow phenomena of the present heat sinks for this impingement cooling. The effects of flow Reynolds numbers (3458≤Re≤11,526), fin height, the geometry of the heat sinks (with/without a hollow perforated base plate), and jet-to-test heat sink placement (1 ≤ H/ d≤16) are examined. In addition, empirical correlation to estimate the heat transfer coefficient was also developed.

Water permeability is a measure of severity in acute appendicitis.

PubMed

Pini, Nicola; Pfeifle, Viktoria A; Kym, Urs; Keck, Simone; Galati, Virginie; Holland-Cunz, Stefan; Gros, Stephanie J

2017-12-01

Acute appendicitis is the most common indication for pediatric abdominal emergency surgery. Determination of the severity of appendicitis on clinical grounds is challenging. Complicated appendicitis presenting with perforation, abscess or diffuse peritonitis is not uncommon. The question remains why and when acute appendicitis progresses to perforation. The aim of this study was to assess the impact of water permeability on the severity of appendicitis. We show that AQP1 expression and water permeability in appendicitis correlate with the stage of inflammation and systemic infection parameters, leading eventually to perforation of the appendix. AQP1 is also expressed within the ganglia of the enteric nervous system and ganglia count increases with inflammation. Severity of appendicitis can be correlated with water permeability measured by AQP1 protein expression and increase of ganglia count in a progressive manner. This introduces the question if regulation of water permeability can present novel curative or ameliorating therapeutic options.

Use of piezosurgery during maxillary sinus elevation: clinical results of 40 consecutive cases.

PubMed

Cassetta, Michele; Ricci, Laura; Iezzi, Giovanna; Calasso, Sabrina; Piattelli, Adriano; Perrotti, Vittoria

2012-12-01

The aim of this study was to evaluate the performance of piezoelectric devices during sinus elevation to determine the percentage of sinus membrane perforation and the time required to perform the antrostomy and elevation of the membrane. A total of 35 patients and 40 grafted sinuses were included. The parameters recorded were bony window length and height, bone thickness, osteotomy area, operative time, and number of perforations. Seven (17.5%) membrane perforations were observed, which were repaired with resorbable membranes. The mean length, height, and thickness of the osteotomy were 13.8 ± 2.9 mm, 6.9 ± 1.4 mm, and 1.4 ± 0.4 mm, respectively. The mean osteotomy area was 96.8 ± 32.2 mm(2), and the mean operative time was 10.3 ± 2.1 minutes. This study demonstrated that a piezoelectric device could be an attractive alternative for successful sinus augmentation.

Regional variation in rates of pediatric perforated appendicitis.

PubMed

Sarda, Samir; Short, Heather L; Hockenberry, Jason M; McCarthy, Ian; Raval, Mehul V

2017-09-01

While trends in perforated appendicitis (PA) rates have been studied, regional variability in pediatric admissions for PA remains unknown. A retrospective, cross-sectional analysis of the 2006-2012 Kids' Inpatient Database was conducted to examine variation in PA admission rates by region of the United States and insurance status. PA rates were calculated and reported as per 1000 admissions in accordance with national quality measure specifications. National PA rates per 1000 admissions for 2006, 2009, and 2012 were 313.9, 279.2, and 309.1, respectively. Similarly, all regions demonstrated a statistically significant decrease in PA rates between 2006 and 2009 (p<0.001), where the increase in rates between 2009 and 2012 was only statistically significant in the Midwest [Odds Ratio (OR) 1.07; 95% Confidence Interval (95%CI) 1.03-1.12] and West (OR 1.10; 95% CI 1.07-1.14). The Northeast consistently experienced the lowest PA rates. The odds of PA were highest among uninsured patients (OR 1.35; 95% CI 1.31-1.29). The South had the highest proportion of uninsured children, and these patients had the highest odds of perforation (OR 1.57; 95% CI 1.21-2.02). For children with appendicitis, geographic region and insurance status appear to be associated with perforation upon presentation. Understanding regional variation in pediatric PA rates may inform health policymakers in the constantly evolving insurance coverage landscape. Level III Treatment Study - Retrospective comparative study of appendicitis presentation in children by region of the country. Copyright © 2017 Elsevier Inc. All rights reserved.

Postoperative Gastric Perforation in a Newborn with Duodenal Atresia.

PubMed

Antabak, Anko; Bogović, Marko; Vuković, Jurica; Grizelj, Ruža; Babić, Vinka Barbarić; Papeš, Dino; Luetić, Tomislav

2016-01-01

Gastric perforation (GP) in neonates is a rare entity with high mortality. Although the etiology is not completely understood, it mostly occurs in premature neonates on assisted ventilation. Combination of duodenal atresia and gastric perforation is very rare. We present a case duodenal atresia who developed gastric perforation after operetion for duodenal atresia. Analysis of the patient medical record and histology report did not reveal the etiology of the perforation.

Porcine experimental model for perforator flap raising in reconstructive microsurgery.

PubMed

González-García, José A; Chiesa-Estomba, Carlos M; Álvarez, Leire; Altuna, Xabier; García-Iza, Leire; Thomas, Izaskun; Sistiaga, Jon A; Larruscain, Ekhiñe

2018-07-01

Perforator free flap-based reconstruction of the head and neck is a challenging surgical procedure and needs a steep learning curve. A reproducible mammal large animal model with similarities to human anatomy is relevant for perforator flap raising and microanastomosis. The aim of this study was to assess the feasibility of a swine model for perforator-based free flaps in reconstructive microsurgery. Eleven procedures were performed under general anesthesia in a porcine model, elevating a skin flap vascularized by perforating musculocutaneous branches of the superior epigastric artery to evaluate the relevance of this model for head and neck reconstructive microsurgery. The anterior abdominal skin perforator-based free flap in a swine model irrigated by the superior epigastric artery was elevated in eleven procedures. In six of these procedures, we could perform an arterial and venous microanastomosis to the great vessels located in the base of the neck. The porcine experimental model of superior epigastric artery perforator-based free flap reconstruction offers relevant similarities to the human deep inferior epigastric artery perforator flap. We could demonstrate this model as acceptable for perforator free flap training due to the necessity of perforator and pedicle dissection and transfer to a distant area. Copyright © 2018 Elsevier Inc. All rights reserved.

Glove perforation in hip and knee arthroplasty.

PubMed

Demircay, Emre; Unay, Koray; Bilgili, Mustafa G; Alataca, Gulum

2010-11-01

The transmission of blood-borne pathogens during surgery is a major concern. Surgical gloves are the primary barrier between the surgeon and the patient. Surgical procedures that need manual handling of bony surfaces or sharp instruments have the highest risk of glove perforations. The frequencies and the sites of surgical glove perforations in arthroplasty procedures were assessed. We assessed the surgical glove perforations in total hip and knee arthroplasty procedures. Double standard latex gloves were used. A total of 983 outer and 511 inner gloves were tested. The gloves of all the surgical team members were tested for perforations during the first and second hours of surgery. There were 18.4% outer and 8.4% inner glove perforations. The most frequent site of perforation was the second digit of the nondominant hand (25.5%). We found that hip and knee arthroplasty had significantly more glove perforation risk for the surgeon in the first half of the operation rather than the second half, and 57.8% of the perforations were at the index finger and the thumb. Arthroplasty procedures still have high glove perforation rates despite the use of double gloving with frequent changes. Extra augmentation of the gloves in selected areas of the hand, in addition to double gloving, may be safer and more cost-effective than double gloving alone.

Postharvest storage quality of grapefruit placed in polyethylene bags with or without micro-perforation

USDA-ARS?s Scientific Manuscript database

Washed ‘Marsh’ white grapefruit were placed in polyethylene (PE) bags (1 mil) with or without micro-perforation holes (representing 0.002% of the bag surface) and evaluated for juice quality, firmness, and the development of decay and disorders during storage for 30, 60, or 90 days at 50oF. Each tre...

Improvement of Anisotropic Mechanical Behavior by Sulfide Control in Quenched and Tempered 4340 Steel

NASA Astrophysics Data System (ADS)

Jung, Jae-Hoon; Shin, Jung-Ho; Lee, Seok-Jae

2015-07-01

The anisotropic mechanical behavior of quenched and tempered 4340 steel with different Ca contents was investigated by means of a macro/micrograph analysis, Charpy impact test, and rotating bending fatigue test. The 4340 steel with Ca added formed small spherical (Ca,Mn)S inclusions and effectively decreased both the inclusion size and the aspect ratio (length to width) of the MnS inclusions as compared to the Ca-free 4340 steel. The anisotropic impact value and fatigue strength were effectively improved due to the Ca addition that prevented the growth of MnS inclusions, which provided increased resistance against deformation to maintain a spherical shape because the elongated MnS inclusions acted as a crack propagation path and promoted the crack propagation due to higher stress concentrations.

Permeation and gating properties of the L-type calcium channel in mouse pancreatic beta cells

PubMed Central

1993-01-01

Ba2+ currents through L-type Ca2+ channels were recorded from cell- attached patches on mouse pancreatic beta cells. In 10 mM Ba2+, single- channel currents were recorded at -70 mV, the beta cell resting membrane potential. This suggests that Ca2+ influx at negative membrane potentials may contribute to the resting intracellular Ca2+ concentration and thus to basal insulin release. Increasing external Ba2+ increased the single-channel current amplitude and shifted the current-voltage relation to more positive potentials. This voltage shift could be modeled by assuming that divalent cations both screen and bind to surface charges located at the channel mouth. The single- channel conductance was related to the bulk Ba2+ concentration by a Langmuir isotherm with a dissociation constant (Kd(gamma)) of 5.5 mM and a maximum single-channel conductance (gamma max) of 22 pS. A closer fit to the data was obtained when the barium concentration at the membrane surface was used (Kd(gamma) = 200 mM and gamma max = 47 pS), which suggests that saturation of the concentration-conductance curve may be due to saturation of the surface Ba2+ concentration. Increasing external Ba2+ also shifted the voltage dependence of ensemble currents to positive potentials, consistent with Ba2+ screening and binding to membrane surface charge associated with gating. Ensemble currents recorded with 10 mM Ca2+ activated at more positive potentials than in 10 mM Ba2+, suggesting that external Ca2+ binds more tightly to membrane surface charge associated with gating. The perforated-patch technique was used to record whole-cell currents flowing through L-type Ca2+ channels. Inward currents in 10 mM Ba2+ had a similar voltage dependence to those recorded at a physiological Ca2+ concentration (2.6 mM). BAY-K 8644 (1 microM) increased the amplitude of the ensemble and whole-cell currents but did not alter their voltage dependence. Our results suggest that the high divalent cation solutions usually used to record single L-type Ca2+ channel activity produce a positive shift in the voltage dependence of activation (approximately 32 mV in 100 mM Ba2+). PMID:7687645

Pediatric appendicitis in a developing country: what are the clinical predictors and outcome of perforation?

PubMed

Ngim, Chin Fang; Quek, Kia Fatt; Dhanoa, Amreeta; Khoo, Joon Joon; Vellusamy, Muthualhagi; Ng, Chen Siew

2014-12-01

This study explored the risk factors and outcomes associated with perforation in children who underwent emergency appendicectomies. A retrospective cross-sectional study was conducted on children <13 years old who underwent appendicectomies in a Malaysian hospital in 2007. One hundred thirty-four children underwent appendicectomies of which 118 were confirmed histologically. Sixty-one (52%) were perforated. Children with perforation had significantly longer duration of symptoms (p < 0.001), higher white cell count and absolute neutrophil counts (p = 0.013), with longer intra-operative period (p < 0.001) and post-operative recovery period (p < 0.001). Of the 52 samples of pus collected intra-operatively, 37 (71.1%) yielded positive cultures that were predominantly Escherichia coli (n = 27). Both the patients who had Staphylococcus aureus cultured from pus collected intra-operatively had significant pyogenic complications (scrotal pyocele and intra-abdominal abscess). Children whose appendicitis were perforated had longer duration of symptoms, higher white cell counts and absolute neutrophil counts. Those with S.aureus cultured from intra-operative pus appeared to suffer more complications. © The Author [2014]. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Intraabdominal contamination after gallbladder perforation during laparoscopic cholecystectomy and its complications.

PubMed

Kimura, T; Goto, H; Takeuchi, Y; Yoshida, M; Kobayashi, T; Sakuramachi, S; Harada, Y

1996-09-01

Gallbladder perforation often occurs during laparoscopic cholecystectomy. The frequency and causes of gallbladder perforation as well as the relevant clinical background factors were investigated in 110 patients undergoing laparoscopic cholecystectomy. We also evaluated intraperitoneal contamination by bacteria and gallstones at the time of gallbladder perforation and investigated whether perforation caused early or late postoperative complications. Intraoperative gallbladder perforation occurred in 29 of the 110 patients (26.3%). It was caused by injury with an electric knife during dissection of the gallbladder bed, injury during gallbladder retraction with grasping forceps, injury during gallbladder extraction from the abdomen, and slippage of cystic duct clips (potentially causing bile and stone spillage). Perforation was more frequent in patients with positive bile cultures and in those with pigment stones (p < 0.02), but not in patients with cholecystitis or cystic duct obstruction. The peritoneal cavity was contaminated by bacteria in 11/29 patients (37.9%) and by spilled stones in 3/29 patients (10.3%). There was no difference in the incidence of postoperative complications between the patients with and without perforation either in the early postoperative period or during follow-up for 24-42 months. Only one patient developed abdominal pain and fever in the early postoperative period, and they were probably related to perforation. Although gallbladder perforation is sometimes unavoidable during laparoscopic cholecystectomy, the risk of severe complications appears to be minimized by early closure of perforation, retrieval of as many of the spilled stones as possible, and intraperitoneal lavage.

Use of inferior gluteal artery and posterior thigh perforators in management of ischial pressure sores with limited donor sites for flap coverage.

PubMed

Unal, Cigdem; Ozdemir, Jale; Yirmibesoglu, Oktay; Yucel, Ergin; Agir, Hakan

2012-07-01

Reconstructive surgery for ischial pressure sore defects presents a challenge because of high rates of recurrence. The aim of this study was to describe the use of inferior gluteal artery (IGA) and posterior thigh perforators in management of ischial pressure sores with limited donor sites. Between September 2005 and 2009, 11 patients (9 male, 2 female) with ischial sores were operated by using IGA and posterior thigh perforator flaps. The data of patients included age, sex, cause of paraplegia, flap size, perforator of flap, previous surgeries, recurrences, complications, and postoperative follow-up. Nine IGA and 5 posterior thigh perforator flaps were used. Six patients presented with recurrent lesions, 5 patients were operated for sacral and contralateral ischial pressure sores previously. In 2 patients, IGA and posterior thigh perforator flaps were used in combination. Patients were followed for an average of 34.3 months. In 2 recurrent cases, readvancement of IGA perforator flap and gluteus maximus myocutaneous flap were treatment of choice. Treatment of patients with recurrent lesions or multiple pressure sores is challenging because of limited available flap donor sites. In this study, posterior thigh perforator flaps were preferred in patients in whom the previous donor site was the gluteal region. IGA perforator flaps were the treatment of choice in patients for whom posterior thigh region was previously used. Alternately, preserved perforators of previous conventional myocutaneous flaps enabled us to use these perforators in recurrences.

Risk factors associated with conversion of laparoscopic simple closure in perforated duodenal ulcer.

PubMed

Kim, Ji-Hyun; Chin, Hyung-Min; Bae, You-Jin; Jun, Kyong-Hwa

2015-03-01

Precise patient selection criteria are necessary to guide the surgeon in selecting laparoscopic repair for patients with perforated peptic ulcers. The aims of this study are to report surgical outcomes after surgery for perforated duodenal ulcers and identify risk factors for predicting failure of laparoscopic simple closure for perforated duodenal ulcer. In total, 77 patients who underwent laparoscopic simple closure for perforated duodenal ulcers from January 2007 to September 2013 were retrospectively analyzed. Patients were divided into totally laparoscopic and conversion groups. The characteristics of patients, intraoperative findings, postoperative complications, conversion rates and suture leakage rates of each group were investigated. Laparoscopic repair was completed in 69 (89.6%) of 77 patients, while 8 (10.4%) underwent conversion to open repair. Patients in the conversion group had longer perforation time, larger perforation size, more suture leakage, longer hospital stay, and higher 30-day mortality rate than those in the totally laparoscopic group. The size of perforation was the only risk factor for conversion in multivariable analysis. Patients with an ulcer perforation size of ≥9 mm or with perforation duration of ≥12.5 h had a significantly increased risk for conversion and suture leakage. Ulcer size of ≥9 mm is a significant risk factor for predicting conversion in laparoscopic simple closure. Suture leakage is associated with ulcer size (9 mm) and duration of perforation (12.5 h). Copyright © 2015 Surgical Associates Ltd. Published by Elsevier Ltd. All rights reserved.

Complications of Celect, Günther tulip, and Greenfield inferior vena cava filters on CT follow-up: a single-institution experience.

PubMed

McLoney, Eric D; Krishnasamy, Venkatesh P; Castle, Jordan C; Yang, Xiangyu; Guy, Gregory

2013-11-01

To evaluate and compare the rates of complications on follow-up computed tomography (CT) studies of patients with Celect, Günther Tulip, and Greenfield inferior vena cava (IVC) filters. Retrospective review of CT studies obtained 0-1,987 days after infrarenal placement of an IVC filter identified 255 Celect, 160 Tulip, and 50 Greenfield filters. Follow-up CT studies were independently evaluated by two observers for IVC perforation, contact with adjacent organs, and filter fracture. Multivariate analysis was performed to identify factors associated with higher rates of IVC perforation, including age, IVC diameter, sex, and history of malignancy. IVC perforation was observed in 126 of 255 Celect filters (49%) with a mean follow-up of 277 days, 69 of 160 Tulip filters (43%) with a mean follow-up of 437 days, and one of 50 Greenfield filters (2%) with a mean follow-up of 286 days. A significantly higher IVC perforation rate was observed in women (45.5%) compared with men (30.8%; P = .002) and in patients with a history of malignancy (43.7%) compared with patients with no history of malignancy (29.9%; P < .001). Filter fracture was rare, observed in two of 255 Celect filters (0.8%), one of 160 Tulip filters (0.6%), and none of 50 Greenfield filters. No significant difference was observed in IVC perforation rate between Celect and Tulip filters. Greenfield filters had a significantly lower rate of IVC perforation than Celect and Tulip filters. Higher IVC perforation rates were observed in women and patients with a history of malignancy. © SIR, 2013.

Perforation of the IVC: rule rather than exception after longer indwelling times for the Günther Tulip and Celect retrievable filters.

PubMed

Durack, Jeremy C; Westphalen, Antonio C; Kekulawela, Stephanie; Bhanu, Shiv B; Avrin, David E; Gordon, Roy L; Kerlan, Robert K

2012-04-01

This study was designed to assess the incidence, magnitude, and impact upon retrievability of vena caval perforation by Günther Tulip and Celect conical inferior vena cava (IVC) filters on computed tomographic (CT) imaging. Günther Tulip and Celect IVC filters placed between July 2007 and May 2009 were identified from medical records. Of 272 IVC filters placed, 50 (23 Günther Tulip, 46%; 27 Celect, 54%) were retrospectively assessed on follow-up abdominal CT scans performed for reasons unrelated to the filter. Computed tomography scans were examined for evidence of filter perforation through the vena caval wall, tilt, or pericaval tissue injury. Procedure records were reviewed to determine whether IVC filter retrieval was attempted and successful. Perforation of at least one filter component through the IVC was observed in 43 of 50 (86%) filters on CT scans obtained between 1 and 880 days after filter placement. All filters imaged after 71 days showed some degree of vena caval perforation, often as a progressive process. Filter tilt was seen in 20 of 50 (40%) filters, and all tilted filters also demonstrated vena caval perforation. Transjugular removal was attempted in 12 of 50 (24%) filters and was successful in 11 of 12 (92%). Longer indwelling times usually result in vena caval perforation by retrievable Günther Tulip and Celect IVC filters. Although infrequently reported in the literature, clinical sequelae from IVC filter components breaching the vena cava can be significant. We advocate filter retrieval as early as clinically indicated and increased attention to the appearance of IVC filters on all follow-up imaging studies.

Distally based sural neuro-fasciocutaneous perforator flap for foot and ankle reconstruction: Surgical modifications for flap pedicle and donor site closure without skin graft.

PubMed

Chi, Zhenglin; Chen, Yiheng; Chu, Tinggang; Gao, Weiyang; Li, Zhijie; Yan, Hede; Song, Yonghuan

2018-02-01

The conventional procedure of the sural neuro-fasciocutaneous flap enables the supply of blood and venous drainage by increasing the width of the adipofascial tissue and preserving tiny venous return routes. Moreover, skin graft is a common method for donor site closure, which may lead to some complications and influence the aesthetic appearance. We report modifications for a distally based sural neuro-fasciocutaneous perforator flap and a relaying flap for donor site closure without skin graft. Twelve patients undergoing the modified flap for foot and ankle reconstruction were included in this study between 2014 and 2016. A peroneal-based perforator, a superficial vein, and the vascular axis of the sural nerve were included in the pedicle. A Z-shape skin incision was performed to explore the perforator vessels and a relaying island perforator flap was used to close the donor site. All flaps survived completely without necrosis. The area of the flaps ranged from 16 × 8 cm to 30 × 15 cm. The diameter width of the pedicle ranged from 1.0 to 2.0 cm. A relaying perforator island flap was used in 10 cases for donor site closure and no skin graft was performed. There were no serious donor site complications. All patients were satisfied with the aesthetic outcome postoperatively at the final follow-up. The distally based sural neuro-fasciocutaneous perforator flap is considered a reliable method for foot and ankle reconstruction. The modification for flap pedicle and donor site closure method without skin graft should be recommended. Copyright © 2017. Published by Elsevier Ltd.

Evaluation of urgent esophagectomy in esophageal perforation

PubMed Central

de AQUINO, José Luis Braga; de CAMARGO, José Gonzaga Teixeira; CECCHINO, Gustavo Nardini; PEREIRA, Douglas Alexandre Rizzanti; BENTO, Caroline Agnelli; LEANDRO-MERHI, Vânia Aparecida

2014-01-01

Background Esophageal trauma is considered one of the most severe lesions of the digestive tract. There is still much controversy in choosing the best treatment for cases of esophageal perforation since that decision involves many variables. The readiness of medical care, the patient's clinical status, the local conditions of the perforated segment, and the severity of the associated injuries must be considered for the most adequate therapeutic choice. Aim To demonstrate and to analyze the results of urgent esophagectomy in a series of patients with esophageal perforation. Methods A retrospective study of 31 patients with confirmed esophageal perforation. Most injuries were due to endoscopic dilatation of benign esophageal disorders, which had evolved with stenosis. The diagnosis of perforation was based on clinical parameters, laboratory tests, and endoscopic images. ‪The main surgical technique used was transmediastinal esophagectomy followed by reconstruction of the digestive tract in a second surgical procedure. Patients were evaluated for the development of systemic and local complications, especially for the dehiscence or stricture of the anastomosis of the cervical esophagus with either the stomach or the transposed colon. Results Early postoperative evaluation showed a survival rate of 77.1% in relation to the proposed surgery, and 45% of these patients presented no further complications. The other patients had one or more complications, being pulmonary infection and anastomotic fistula the most frequent. The seven patients (22.9%) who underwent esophageal resection 48 hours after the diagnosis died of sepsis. At medium and long-term assessments, most patients reported a good quality of life and full satisfaction regarding the surgery outcomes. Conclusions Despite the morbidity, emergency esophagectomy has its validity, especially in well indicated cases of esophageal perforation subsequent to endoscopic dilation for benign strictures. PMID:25626932

Perforator Propeller Flap for Oncologic Reconstruction of Soft Tissue Defects in Trunk and Extremities.

PubMed

Yu, Shengji; Zang, Mengqing; Xu, Libin; Zhao, Zhenguo; Zhang, Xinxin; Zhu, Shan; Chen, Bo; Ding, Qiang; Liu, Yuanbo

2016-10-01

Defects after soft tissue sarcoma resection are usually managed by myocutaneous flaps or free flaps. However, harvesting muscle will cause functional morbidities, and some regions lack reliable recipient vessel. Our purpose is to use various perforator propeller flaps for oncologic reconstruction. Between 2008 and 2014, 33 perforator propeller flaps were performed in 24 patients to reconstruct the defects after tumor resection in trunk and extremities. Fifteen patients underwent tumor resection previously. Thirteen patients underwent adjuvant radiotherapy or chemotherapy. Flaps based on perforators adjacent to the lesions were raised and rotated in propeller fashion to repair the defects. Twenty-seven flaps were based on perforators of known source vessels, and 6 were harvested in freestyle fashion. The defects were repaired with 2 flaps in 4 patients and 3 flaps in 2 patients. The mean skin paddle dimension was 8.36 cm in width and 20.42 cm in length. The mean degree of flap rotation was 158.79°. Complications include partial necrosis of 6 flaps in 5 cases and venous congestion of 1 flap. In these 6 patients, 3 underwent adjuvant radiotherapy. The donor sites were primarily closed in 21 patients and skin grafted in 3 patients. No functional loss related to flap harvesting was recognized. The perforator propeller flaps can be used to manage the medium defects in extremities and large defects in torso after soft tissue sarcoma resection. They avoid the sacrifice of the underlying muscle and eliminate the concerns of the unavailability of recipient vessels. The perforator propeller flaps provide flexible options for versatile oncologic reconstruction in trunk and extremities. However, the impact of radiotherapy on the viability of the flaps for local reconstruction needs further investigation.

Perforation of the IVC: Rule Rather Than Exception After Longer Indwelling Times for the Guenther Tulip and Celect Retrievable Filters

DOE Office of Scientific and Technical Information (OSTI.GOV)

Durack, Jeremy C., E-mail: jeremy.durack@ucsf.edu; Westphalen, Antonio C.; Kekulawela, Stephanie

Purpose: This study was designed to assess the incidence, magnitude, and impact upon retrievability of vena caval perforation by Guenther Tulip and Celect conical inferior vena cava (IVC) filters on computed tomographic (CT) imaging. Methods: Guenther Tulip and Celect IVC filters placed between July 2007 and May 2009 were identified from medical records. Of 272 IVC filters placed, 50 (23 Guenther Tulip, 46%; 27 Celect, 54%) were retrospectively assessed on follow-up abdominal CT scans performed for reasons unrelated to the filter. Computed tomography scans were examined for evidence of filter perforation through the vena caval wall, tilt, or pericaval tissuemore » injury. Procedure records were reviewed to determine whether IVC filter retrieval was attempted and successful. Results: Perforation of at least one filter component through the IVC was observed in 43 of 50 (86%) filters on CT scans obtained between 1 and 880 days after filter placement. All filters imaged after 71 days showed some degree of vena caval perforation, often as a progressive process. Filter tilt was seen in 20 of 50 (40%) filters, and all tilted filters also demonstrated vena caval perforation. Transjugular removal was attempted in 12 of 50 (24%) filters and was successful in 11 of 12 (92%). Conclusions: Longer indwelling times usually result in vena caval perforation by retrievable Guenther Tulip and Celect IVC filters. Although infrequently reported in the literature, clinical sequelae from IVC filter components breaching the vena cava can be significant. We advocate filter retrieval as early as clinically indicated and increased attention to the appearance of IVC filters on all follow-up imaging studies.« less

Swedish Defence Research Abstracts 79/80-4 (Froe Foersvars Forsknings Referat 79/80-4).

DTIC Science & Technology

1980-12-05

wavelength. In order to verify and modify the model, measurements were made with a transmissometer over a horizontal measuring path . The equipment was...wavelength. In order to verify and modify the model, measurements were made with a transmissometer over a horizontal measuring path . The equipment was in... measurements taken from a number of meteoro loi ca I sensors. Aerosol .xtinc tion was obtained by subtracting the water vapour extinction , as calculated trom

Multivariate statistical analysis and hydrogeochemical modelling of seawater-freshwater mixing along selected flow paths: Case of Korba coastal aquifer Tunisia

NASA Astrophysics Data System (ADS)

Slama, Fairouz; Bouhlila, Rachida

2017-11-01

Groundwater sampling and piezometric measurements were carried out along two flow paths (corresponding to two transects) in Korba coastal plain (Northeast of Tunisia). The study aims to identify hydrochemical processes occurring when seawater and freshwater mix. Those processes can be used as indicators of seawater intrusion progression and freshwater flushing into seawater accompanying Submarine Groundwater Discharge (SGD). Seawater fractions in the groundwater were calculated using the chloride concentration. Hierarchical cluster analysis (HCA) was applied to isolate wells potentially affected by seawater. In addition, PHREEQC was used to simulate the theoretical mixing between two end members: seawater and a fresh-brackish groundwater sample. Geochemical conventional diagrams showed that the groundwater chemistry is explained by a mixing process between two end members. Results also revealed the presence of other geochemical processes, correlated to the hydrodynamic flow paths. Direct cation exchange was linked to seawater intrusion, and reverse cation exchange was associated to the freshwater flushing into seawater. The presence of these processes indicated that seawater intrusion was in progress. An excess of Ca, that could not be explained by only cation exchange processes, was observed in both transects. Dedolomitization combined to gypsum leaching is the possible explanation of the groundwater Ca enrichment. Finally, redox processes were also found to contribute to the groundwater composition along flow paths.

[Pedicle flap of nasal septum-basis nasi and temporal muscucofascial flap to repair nasoseptal perforation].

PubMed

Yin, Xinghong; Hu, Wei; Zhang, Xinhai; Sun, Min

2014-10-01

To explore curative effect with pedicle flap of nasal septum-basis nasi and temporal muscucofascial flap to repair nasal septal perforation. Dissecting mucoperichondrium and mucoperioseptum around the perforation and taking dowm and out xia-ward to the floor of nasal cavity to make a inferior extremity pedicle flap. Then,the flap was tumbled and sutured onto raw surface of contralateral side through perforation. Reapplicating autoallergic temporal musculofascial flap to repair another side perforation. Repairing perforation Sin twelve cases were sucessfully healed in endoscope. The pedicle flap of nasal septum-basis nasi and temporal muscucofascial flap is easy to acquire and no rejection. The flap has good blood supplying, high survival rate and provides adequate transplantating materail to repair comparatively large perforation.

Postoperative Gastric Perforation in a Newborn with Duodenal Atresia

PubMed Central

Antabak, Anko; Bogović, Marko; Vuković, Jurica; Grizelj, Ruža; Babić, Vinka Barbarić; Papeš, Dino; Luetić, Tomislav

2016-01-01

Gastric perforation (GP) in neonates is a rare entity with high mortality. Although the etiology is not completely understood, it mostly occurs in premature neonates on assisted ventilation. Combination of duodenal atresia and gastric perforation is very rare. We present a case duodenal atresia who developed gastric perforation after operetion for duodenal atresia. Analysis of the patient medical record and histology report did not reveal the etiology of the perforation. PMID:27896170

Using heterostructural alloying to tune the structure and properties of the thermoelectric Sn 1–xCa xSe

DOE Office of Scientific and Technical Information (OSTI.GOV)

Matthews, Bethany E.; Holder, Aaron M.; Schelhas, Laura T.

We grow and kinetically stabilize the isotropic rocksalt phase of SnSe thin films by alloying SnSe with CaSe. Thin polycrystalline films of the metastable heterostructural alloy Sn 1–xCa xSe are synthesized by pulsed laser deposition on amorphous SiO 2 over the entire composition range 0 < x < 1. We observe the theoretically-predicted, composition-driven change from a layered, orthorhombic structure to an isotropic, cubic structure near x = 0.18, in reasonable agreement with the theoretical value of x = 0.13 calculated from first principles. The optical band gap is highly non-linear in x and the trend agrees with theory predictions.more » Compared to the layered end-member SnSe, the isotropic alloy near the orthorhombic-to-rocksalt transition has a p-type electrical resistivity three orders of magnitude lower, and a thermoelectric power factor at least ten times larger. Furthermore manipulation of the structure of a functional material like SnSe via alloying may provide a new path to enhanced functionality, in this case, improved thermoelectric performance.« less

Using heterostructural alloying to tune the structure and properties of the thermoelectric Sn 1–xCa xSe

DOE PAGES

Matthews, Bethany E.; Holder, Aaron M.; Schelhas, Laura T.; ...

2017-07-21

We grow and kinetically stabilize the isotropic rocksalt phase of SnSe thin films by alloying SnSe with CaSe. Thin polycrystalline films of the metastable heterostructural alloy Sn 1–xCa xSe are synthesized by pulsed laser deposition on amorphous SiO 2 over the entire composition range 0 < x < 1. We observe the theoretically-predicted, composition-driven change from a layered, orthorhombic structure to an isotropic, cubic structure near x = 0.18, in reasonable agreement with the theoretical value of x = 0.13 calculated from first principles. The optical band gap is highly non-linear in x and the trend agrees with theory predictions.more » Compared to the layered end-member SnSe, the isotropic alloy near the orthorhombic-to-rocksalt transition has a p-type electrical resistivity three orders of magnitude lower, and a thermoelectric power factor at least ten times larger. Furthermore manipulation of the structure of a functional material like SnSe via alloying may provide a new path to enhanced functionality, in this case, improved thermoelectric performance.« less

Tensor fascia lata flap versus tensor fascia lata perforator-based island flap for the coverage of extensive trochanteric pressure sores.

PubMed

Kim, Youn Hwan; Kim, Sang Wha; Kim, Jeong Tae; Kim, Chang Yeon

2013-06-01

Tensor fascia lata (TFL) musculocutaneous flaps often require a donor site graft when harvesting a large flap. However, a major drawback is that it also sacrifices the muscle. To overcome this disadvantage, we designed a TFL perforator-based island flap that was harvested from a site near the defect and involved transposition within 90 degrees without full isolation of the pedicles. We performed procedures on 17 musculocutaneous flaps and 23 perforator-based island flaps, and compared the outcomes of these surgeries. The overall complication rate was 27.5% (11 regions). There were 7 complications related to the musculocutaneous flaps and 4 complications related to the perforator flaps. Although there were no statistical differences between those groups, lower complication rates were associated with procedures involving perforator flaps. The TFL perforator procedure is a simple and fast operation that avoids sacrificing muscle. This decreases complication rates compared to true perforator flap techniques that require dissection around the perforator or pedicle.

Risky Business: Risk Tolerance in U.S. Army Special Forces

DTIC Science & Technology

2014-06-01

24 Edgar H . Schein , Organizational Culture and Leadership (San Francisco, CA: Jossey-Bass, 1997), 144–146. 25 Steven Kerr, “On the Folly of Rewarding...Armies, 1888–1918. London: Frank Cass & Co, 1995. Schein , Edgar H . Organizational Culture and Leadership. San Francisco, CA: Jossey- Bass, 1997. 67...University of New Hampshire: South- Western Thomson Learning, 2003), 82. 12 development could result in a path-dependent pattern.23 Schein explores

The efficacy of combined therapy with metronidazole and broad-spectrum antibiotics on postoperative outcomes for pediatric patients with perforated appendicitis

PubMed Central

Shang, Qingjuan; Geng, Qiankun; Zhang, Xuebing; Guo, Chunbao

2017-01-01

Abstract The aim of this study was to evaluate the efficacy of combined therapy with metronidazole and broad-spectrum antibiotics for patients with perforated appendicitis who underwent surgical intervention. Broad-spectrum antibiotic therapy is warranted in the treatment of perforated appendicitis. Metronidazole has been used as anaerobic antimicrobial therapy. However, few studies about the use of metronidazole in perforated appendicitis have been reported. The medical records of 249 patients treated with metronidazole combined with broad-spectrum antibiotics following perforated appendicitis surgery were reviewed retrospectively and compared with the medical records of 149 patients treated only with broad-spectrum antibiotics. Propensity score matching was performed to adjust for selected baseline variables. Clinical outcomes, including postoperative complications and length of hospital stay, were compared between the 2 groups. No differences were found between the use of combined therapy with metronidazole and the use of solely broad-spectrum antibiotic agents with regard to postoperative duration of intravenous antibiotic treatment (6.8 ± 1.3 vs 7.9 ± 2.1 days, respectively, P = .18), inflammation variables at POD 5 (white blood cell [WBC] [risk ratio [RR], 1.06; 95% confidence interval [CI], 0.67–1.93, P = .15] and C-reactive protein [CRP] [RR, 1.18; 95% CI, 0.73–2.25, P = .36]) (Table 2), and the mean postoperative length of hospital stay (LOS) (RR, 0.68, 95% CI, 0.41–0.94, P = .41). There were also no differences in the incidence of postoperative complications, including the intra-abdominal or pelvic abscess rate (7[7.1%] vs 9[9.2%], respectively, P = .40), the incidence of wound infection (14[14.3%] vs 15[15.3%], respectively, P = .50), and the 30-day readmission rate (9[9.2%] vs 12[12.2%], respectively, P = .32). Regarding overall postoperative outcomes and complications, our study demonstrated no beneficial clinical effects of metronidazole administration in patients with perforated appendicitis who underwent surgical intervention. Therefore, metronidazole is not indicated when broad-spectrum antibiotics such as aminopenicillins with β-lactam inhibitors or carbapenems and select cephalosporins are used. PMID:29381994

The efficacy of combined therapy with metronidazole and broad-spectrum antibiotics on postoperative outcomes for pediatric patients with perforated appendicitis.

PubMed

Shang, Qingjuan; Geng, Qiankun; Zhang, Xuebing; Guo, Chunbao

2017-11-01

The aim of this study was to evaluate the efficacy of combined therapy with metronidazole and broad-spectrum antibiotics for patients with perforated appendicitis who underwent surgical intervention.Broad-spectrum antibiotic therapy is warranted in the treatment of perforated appendicitis. Metronidazole has been used as anaerobic antimicrobial therapy. However, few studies about the use of metronidazole in perforated appendicitis have been reported.The medical records of 249 patients treated with metronidazole combined with broad-spectrum antibiotics following perforated appendicitis surgery were reviewed retrospectively and compared with the medical records of 149 patients treated only with broad-spectrum antibiotics. Propensity score matching was performed to adjust for selected baseline variables. Clinical outcomes, including postoperative complications and length of hospital stay, were compared between the 2 groups.No differences were found between the use of combined therapy with metronidazole and the use of solely broad-spectrum antibiotic agents with regard to postoperative duration of intravenous antibiotic treatment (6.8 ± 1.3 vs 7.9 ± 2.1 days, respectively, P = .18), inflammation variables at POD 5 (white blood cell [WBC] [risk ratio [RR], 1.06; 95% confidence interval [CI], 0.67-1.93, P = .15] and C-reactive protein [CRP] [RR, 1.18; 95% CI, 0.73-2.25, P = .36]) (Table 2), and the mean postoperative length of hospital stay (LOS) (RR, 0.68, 95% CI, 0.41-0.94, P = .41). There were also no differences in the incidence of postoperative complications, including the intra-abdominal or pelvic abscess rate (7[7.1%] vs 9[9.2%], respectively, P = .40), the incidence of wound infection (14[14.3%] vs 15[15.3%], respectively, P = .50), and the 30-day readmission rate (9[9.2%] vs 12[12.2%], respectively, P = .32).Regarding overall postoperative outcomes and complications, our study demonstrated no beneficial clinical effects of metronidazole administration in patients with perforated appendicitis who underwent surgical intervention. Therefore, metronidazole is not indicated when broad-spectrum antibiotics such as aminopenicillins with β-lactam inhibitors or carbapenems and select cephalosporins are used. Copyright © 2017 The Authors. Published by Wolters Kluwer Health, Inc. All rights reserved.

Comparison between open and laparoscopic repair of perforated peptic ulcer disease.

PubMed

Bhogal, Ricky H; Athwal, Ruvinder; Durkin, Damien; Deakin, Mark; Cheruvu, Chandra N V

2008-11-01

The place of laparoscopic repair of perforated peptic ulcer followed by peritoneal toilet has been established, although it is not routinely practiced. This prospective study compared laparoscopic and open repair of perforated peptic ulcer disease. We evaluated whether the early results from laparoscopic repair resulted in improved patient outcome compared with conventional open repair. All patients who underwent repair of perforated peptic ulcer disease during a 12-month period in our unit were included in the study. The primary end points that were evaluated were total operative time, nasogastric tube utilisation, intravenous fluid requirement, total time of urinary catheter and abdominal drainage usage, time taken to return to normal diet, intravenous/intramuscular opiate use, time to full mobilization, and total in-patient hospital stay. Thirty-three patients underwent surgical repair of perforated peptic ulcer disease (19 laparoscopic repairs and 14 open repairs; mean age, 54.2 (range, 32-82) years). There was no increase in total operative time in patients who had undergone laparoscopic repair (mean: 61 minutes laparoscopic versus 57 minutes open). There was significantly less requirement for intravenous/intramuscular opiate analgesia in patients who had undergone laparoscopic repair (mean time to oral analgesia: 1.2 days laparoscopic versus 3.8 days open). In addition there was a significant decrease in the time that the nasogastric tube (mean: 2.1 days laparoscopic versus 3.1 days open), urinary catheter (mean: 2.3 days laparoscopic versus 3.7 days open) and abdominal drain (mean: 2.2 days laparoscopic versus 3.8 days open) were required during the postoperative period. Patients who had undergone laparoscopic repair required less intravenous fluids (mean: 1.4 days laparoscopic versus 3.1 days open) and returned to normal diet (mean: 2.3 days laparoscopic versus 4.8 days open) and full mobilization significantly earlier than those who had undergone open repair (mean: 2.3 days laparoscopic versus 3.3 days open). In addition, patients who had undergone laparoscopic repair required a shorter in-patient hospital stay (mean: 3.1 days laparoscopic versus 4.3 days open). Laparoscopic repair is a viable and safe surgical option for patients with perforated peptic ulcer disease and should be considered for all patients, providing that the necessary expertise is available.

[Ultrasonic monitoring foam sclerotherapy for serious varicosis of lower extremity].

PubMed

Yin, Heng-hui; Pan, Fu-shun; Huang, Xue-ling; Chang, Guang-qi; Wang, Shen-ming

2013-11-19

To evaluate the efficacy and safety of foam sclerotherapy for lower extremity varicosis in C4 to C6 patients. A total of 32 patients (32 limbs) with serious lower extremity varicosis classified as C4 to C6 were enrolled. Ultrasonic monitoring of foam sclerotherapy was performed after subfascial endoscopic perforator suture and saphenous vein ligation. They were followed up monthly at outpatient department. Duplex Doppler scan was performed during each interview. All patients were treated successfully. An average of 3.2 perforators were ligated per leg (1-5 perforators). The average volume of foam sclerosing agent was 27.5 ml per leg. Mild chest tightness was observed in one patient but computed tomography (CT) scan excluded pulmonary embolism. Obvious local inflammatory reaction was observed in 4 patients. Residual vein mass without blood signal was seen in 3 patients. No such serious complication as cerebral ischemia was observed. The average follow-up period was 4.8 (1-10) months. Obvious varicose veins and clinical symptoms disappeared at 1 month. And venous ulcers in patients classified as C5 healed within 3 months. Ultrasonic monitoring of foam sclerotherapy, incorporation with saphenous vein ligation and subfascial endoscopic perforator suture, is both safe and effective in the treatment of serious lower extremity varicosis classified as C4 to C6.

A Quantitative Evaluation of SCEC Community Velocity Model Version 3.0

NASA Astrophysics Data System (ADS)

Chen, P.; Zhao, L.; Jordan, T. H.

2003-12-01

We present a systematic methodology for evaluating and improving 3D seismic velocity models using broadband waveform data from regional earthquakes. The operator that maps a synthetic waveform into an observed waveform is expressed in the Rytov form D(ω ) = {exp}[{i} ω δ τ {p}(ω ) - ω δ τ {q}(ω )]. We measure the phase delay time δ τ p(ω ) and the amplitude reduction time δ τ q(ω ) as a function of frequency ω using Gee & Jordan's [1992] isolation-filter technique, and we correct the data for frequency-dependent interference and frequency-independent source statics. We have applied this procedure to a set of small events in Southern California. Synthetic seismograms were computed using three types of velocity models: the 1D Standard Southern California Crustal Model (SoCaL) [Dreger & Helmberger, 1993], the 3D SCEC Community Velocity Model, Version 3.0 (CVM3.0) [Magistrale et al., 2000], and a set of path-averaged 1D models (A1D) extracted from CVM3.0 by horizontally averaging wave slownesses along source-receiver paths. The 3D synthetics were computed using K. Olsen's finite difference code. More than 1000 measurements were made on both P and S waveforms at frequencies ranging from 0.2 to 1 Hz. Overall, the 3D model provided a substantially better fit to the waveform data than either laterally homogeneous or path-dependent 1D models. Relative to SoCaL, CVM3.0 provided a variance reduction of about 64% in δ τ p, and 41% in δ τ q. Relative to A1D, the variance reduction is about 46% and 20%, respectively. The same set of measurements can be employed to invert for both seismic source properties and seismic velocity structures. Fully numerical methods are being developed to compute the Fréchet kernels for these measurements [L. Zhao et. al., this meeting]. This methodology thus provides a unified framework for regional studies of seismic sources and Earth structure in Southern California and elsewhere.

Electrophysiological mechanisms of sophocarpine as a potential antiarrhythmic agent.

PubMed

Yang, Zhi-fang; Li, Ci-zhen; Wang, Wei; Chen, Ying-min; Zhang, Ying; Liu, Yuan-mou; Wang, Hong-wei

2011-03-01

To examine the electrophysiological effects of sophocarpine on action potentials (AP) and ionic currents of cardiac myocytes and to compare some of these effects with those of amiodarone. Langendorff perfusion set-up was used in isolated guinea pig heart, and responses to sophocarpine were monitored using electrocardiograph. Conventional microelectrode, voltage clamp technique and perforated patch were employed to record fast response AP (fAP), slow response AP (sAP) and ionic currents in guinea pig papillary muscle or rabbit sinus node cells. Tachyarrhythmia produced by isoprenaline (15 μmol/L) could be reversed by sophocarpine (300 μmol/L). Sophocarpine (10 μmol/L) decreased the amplitude by 4.0%, maximal depolarization velocity (V(max)) of the fAP by 24.4%, and Na(+) current (I(Na)) by 18.0%, while it prolonged the effective refractory period (ERP) by 21.1%. The same concentration of sophocarpine could also decrease the amplitude and V(max) of the sAP, by 26.8% and 25.7%, respectively, and attenuated the Ca(2+) current (I(CaL)) and the K(+) tail current substantially. Comparison of sophocarpine with amiodarone demonstrated that both prolonged the duration and the ERP of fAP and sAP, both decreased the amplitude and V(max) of the fAP and sAP, and both slowed the automatic heart rate. Sophocarpine could reverse isoprenaline-induced arrhythmia and inhibit I(Na), I(CaL), and I(Kr) currents. The electrophysiological effects of sophocarpine are similar to those of amiodarone, which might be regarded as a prospective antiarrhythmic agent.

Hyperbilirubinemia as a Diagnostic Tool for the Prediction of Appendicular Perforation: A Prospective Study.

PubMed

Saxena, Divish; Tandon, Mrinal; Shah, Yunus; Gedam, B S

2015-01-01

The certainty of diagnosing acute appendicitis in patients presenting with right iliac fossa pain still remains a mystery though acute appendicitis being the commonest surgical procedure done in emergency. In acute appendicitis, serum bilirubin levels are raised due to hepatocellular damage as a result of direct insult caused by Gram-negative bacterial endotoxemia. The need for the study is to conclude whether the serum bilirubin can be considered as a new laboratory marker to aid in the diagnosis of acute appendicitis and if so, does it have the predictive capacity to warn us about appendicular perforation. This is a prospective study carried out at rural tertiary healthcare center and includes 213 patients clinically diagnosed as acute appendicitis. Out of 213 patients, raised serum bilirubin ≥1.2 mg/dl was present in 195 (91.5%) patients, out of which 194 (99.4%) patients had histopathologically inflamed appendix and this difference was statistically highly significant with p-value < 0.0001. In this study, 32 patients had perforated appendix. Out of those, 30 patients had bilirubin ≥ 4 mg/dl and 2 patients had bilirubin level between 1.2 and < 4 mg/dl. Raised serum bilirubin (≥4 mg/dl) was present in 35 (17.9%) patients, out of which 30 (87.7%) patients had perforated appendix. Saxena D, Tandon M, Shah Y, Gedam BS. Hyperbilirubinemia as a Diagnostic Tool for the Prediction of Appendicular Perforation: A Prospective Study. Euroasian J Hepato-Gastroenterol 2015;5(2):87-89.

Covered Biodegradable Stent: New Therapeutic Option for the Management of Esophageal Perforation or Anastomotic Leak

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cerna, Marie; Koecher, Martin, E-mail: martin.kocher@seznam.cz; Valek, Vlastimil

2011-12-15

Purpose: This study was designed to evaluate our experience with the treatment of postoperative anastomotic leaks and benign esophageal perforations with covered biodegradable stents. Materials and Methods: From 2008 to 2010, we treated five men with either an anastomotic leak or benign esophageal perforation by implanting of covered biodegradable Ella-BD stents. The average age of the patients was 60 (range, 38-74) years. Postoperative anastomotic leaks were treated in four patients (1 after esophagectomy, 1 after resection of diverticulum, 2 after gastrectomy). In one patient, perforation occurred as a complication of the treatment of an esophageal rupture (which occurred during amore » balloon dilatation of benign stenosis) with a metallic stent. Results: Seven covered biodegradable stents were implanted in five patients. Primary technical success was 100%. Clinical success (leak sealing) was achieved in four of the five patients (80%). Stent migration occurred in three patients. In two of these patients, the leak had been sealed by the time of stent migration, therefore no reintervention was necessary. In one patient an additional stent had to be implanted. Conclusion: The use of biodegradable covered stents for the treatment of anastomotic leaks or esophageal perforations is technically feasible and safe. The initial results are promising; however, larger number of patients will be required to evaluate the capability of these biodegradable stents in the future. The use of biodegradable material for coverage of the stent is essential.« less

Perforated peptic ulcer in southeastern Taiwan.

PubMed

Li, Chin-Hsien; Chang, Wen-Hsiung; Shih, Shou-Chuan; Lin, Shee-Chan; Bair, Ming-Jong

2010-09-01

No studies focus on the population with perforated peptic ulcer in southeastern Taiwan. The present study aimed to assess the differences between the different races and the risk factors related to mortality and morbidity in postoperative patients in southeastern Taiwan. The medical records of 237 patients were reviewed retrospectively. The following factors were analyzed: patient profiles, coexisting illnesses, diagnostic method, fever, preoperative shock, clinical data at emergency room, delay operation, site of perforation, operative method, positive ascites culture, species of microbes in ascites culture, postoperative complications, death and the length of hospital stay. Aborigines were significantly different from non-aborigines in the ratio of female cases and in the habits of alcohol drinking and betel nut chewing. There were also four significantly different variables between them: fever, hemoglobin value, site of perforation and operative method. Total postoperative complication rate was 41.3% and 39 patients (16.6%) died. In multivariate analysis, age > or = 65 years, lipase > upper normal limit and preoperative shock were independent predictors of mortality. Significant risk factors associated with morbidity were NSAIDs use, creatinine > 1.5 mg/dL and preoperative shock. Aborigines were different from non-aborigines in several categories. In southeastern Taiwan, NSAIDs use, creatinine > 1.5 mg/dL and preoperative shock were independent risk factors of morbidity, and age > or = 65 years, lipase > upper normal limit and preoperative shock were independent risk factors of mortality in postoperative perforated peptic ulcer. Lipase > upper normal limit is needed for further research on the influence on mortality.

TRIDIMENSIONAL DOPPLER ASSESSMENT: A RELIABLE, NON-INVASIVE AND COST-EFFECTIVE METHOD FOR PREOPERATIVE PERFORATOR ASSESSMENT IN DIEP FLAP.

PubMed

Dražan, L; Lombardo, G A G

The preoperative perforator mapping is an important step in autologous breast reconstruction, making the flap raising safer, more predictable and time-saving. Although the Doppler exam has proven to be less accurate in locating perforators compared with colour duplex sonography and CTA, it will probably remain of importance in clinical practice. The aim of this paper is to share some advices on how to perform a Doppler exam in preoperative evaluation of a DIEAp flap, increasing its reliability in location of the perforators. The study was carried-out preoperatively on 26 consecutive patients. For the evaluation of the matching between Doppler Dot and operative finding was used a Cartesian coordinate systemResults: We have marked preoperatively 145 perforators in 26 patients for a total of 52 semi-abdomens. An average of 5.6 vessels per patient were marked. Of these, 80 (55.17%) were found between 0-1 cm, 36 (24.82%) between 1-2 cm and 5 (3.4%) of these more than 2 cm from each other. We had 24 (16.55%) false positives in which there was no correspondence between the signal and the intraoperative finding. Although the Doppler exam may not provide the same anatomic details as the other newer modalities, such as CTA and MRA, the HHD remains a very useful and important tool for autologous reconstruction. We recommend performing this exam in our standardized and reproducible method to improve the reliability..

Glove Perforations During Interventional Radiological Procedures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Leena, R. V., E-mail: leenarv_76@yahoo.co.uk; Shyamkumar, N. K.

2010-04-15

Intact surgical gloves are essential to avoid contact with blood and other body fluids. The objective of this study was to estimate the incidence of glove perforations during interventional radiological procedures. In this study, a total of 758 gloves used in 94 interventional radiological procedures were examined for perforations. Eleven perforations were encountered, only one of which was of occult type. No significant difference in the frequency of glove perforation was found between the categories with varying time duration.

Morphometric Study of the Anterior Thalamoperforating Arteries

PubMed Central

Kim, Sung-Ho; Yeo, Dong-Kyu; Shim, Jae-Joon; Yoon, Seok-Mann; Chang, Jae-Chil

2015-01-01

Objective To evaluate the morphometry of the anterior thalamoperforating arteries (ATPA). Methods A microanatomical study was performed in 79 specimens from 42 formalin-fixed adult cadaver brains. The origins of the ATPAs were divided into anterior, middle, and posterior segments according to the crowding pattern. The morphometry of the ATPAs, including the premammillary artery (PMA), were examined under a surgical microscope. Results The anterior and middle segments of the ATPAs arose at mean intervals of 1.75±1.62 mm and 5.86±2.05 mm from the internal carotid artery (ICA), and the interval between these segments was a mean of 3.17±1.64 mm. The posterior segment arose at a mean interval of 2.43±1.46 mm from the posterior cerebral artery (PCA), and the interval between the middle and posterior segments was a mean of 3.45±1.39 mm. The mean numbers of perforators were 2.66±1.19, 3.03±1.84, and 1.67±0.98 in the anterior, middle, and posterior segments, respectively. The PMA originated from the middle segment in 66% of cases. A perforator-free zone was located >2 mm from the ICA in 30.4% and >2 mm from the PCA in 67.1% of cases. Conclusion Most perforators arose from the anterior and middle segments, within the anterior two-thirds of the posterior communicating artery (PCoA). The safest perforator-free zone was located closest to the PCA. These anatomical findings may be helpful to verify safety when treating lesions around the PCoA and in the interpeduncular fossa. PMID:26113962

Reconstruction of Anterolateral Thigh Defects Using Perforator-Based Propeller Flaps.

PubMed

Iida, Takuya; Yoshimatsu, Hidehiko; Koshima, Isao

2017-10-01

Usually, anterolateral thigh (ALT) defects with width more than 8 cm cannot be closed directly. Although several methods of using local flaps exist, flap mobility of these methods is limited. We introduced a perforator-based propeller flap for such reconstruction. Their maximal mobility, which minimizes their size, is their greatest advantage. In addition, we present our technical refinements including double-axes propeller flap, the use of indocyanine green real-time angiography, and supercharged propeller flap for safer flap transfer. Seven patients underwent perforator-based propeller flap reconstruction of ALT defects. Flaps were designed cranial or caudal to the defect according to the perforator locations. To maximize mobility, flaps were designed so that the perforator was located at the periphery and closer to the defect. After rotating the flap to the defect, indocyanine green angiography was performed to determine the need for supercharge. In all cases, all flaps survived completely. Defect size ranged from 12 × 11 cm to 18 × 16 cm, and flap size ranged from 7 × 5 cm to 15 × 7 cm. The number of perforators in the flap was 1 in 3 cases and 2 in 4 cases. Supercharging was performed in 3 cases. Donor-site complications, including gait disturbance, were not observed. This method achieves ALT defect closure with minimal donor-site morbidity and can provide prompt and aesthetically acceptable results. Indocyanine green real-time angiography and supercharging technique are also useful for safer and reliable flap transfer.

The "chimeric" trapezius muscle and fasciocutaneous flap (dorsal scapular artery perforator flap): a new design for complex 3-dimensional defects.

PubMed

Rozen, Warren M; Fox, Carly M; Leong, James; Morsi, Adel

2013-11-01

Multiple variations of the musculocutaneous trapezius flap have been described, each of which use a single composite musculocutaneous unit in their designs. The limitation of such designs is the ability to use the components in a 3-dimensional manner, with only 1 vector existing in the geometry of the musculocutaneous unit. A review of the literature was undertaken with regard to designs of the musculocutaneous trapezius flap, and we present a new technique for flap design. With identification of individual perforators to each of the muscle and fasciocutaneous portions of the trapezius flap, the 2 components can act in a chimeric fashion, able to fill both a deep and complex 3-dimensional space while covering the wound with robust skin. A range of flap designs have been described, including transverse, oblique, and vertical skin paddles accompanying the trapezius muscle. We describe a technique with which a propeller-style skin paddle based on a cutaneous perforator can be raised in any orientation with respect to the underlying muscle. In a presented case, separation of the muscular and fasciocutaneous components of the trapezius flap was able to obliterate dead space around exposed cervicothoracic spinal metalwork and obtain robust wound closure in a patient with previous radiotherapy. This concomitant use of a muscle and fasciocutaneous perforator flap based on a single perforator, a so-called chimeric perforator flap, is a useful modification to trapezius musculocutaneous flap design.

Diagnosing perforated appendicitis in pediatric patients: a new model.

PubMed

van den Bogaard, Veerle A B; Euser, Sjoerd M; van der Ploeg, Tjeerd; de Korte, Niels; Sanders, Dave G M; de Winter, Derek; Vergroesen, Diederik; van Groningen, Krijn; de Winter, Peter

2016-03-01

Studies have investigated sensitivity and specificity of symptoms and tests for diagnosing appendicitis in children. Less is known with regard to the predictive value of these symptoms and tests with respect to the severity of appendicitis. The aim of this study was to determine the predictive value of patient's characteristics and tests for discriminating between perforated and nonperforated appendicitis in children. Pediatric patients who underwent an appendectomy at Spaarne Hospital Hoofddorp, the Netherlands, between January 1, 2009 and December 31, 2013, were included. Baseline patient's characteristics, history, physical examination, laboratory data and results of ultrasounds were collected. Univariate and multivariate logistic regressions were used to determine predictors of perforation. In total, 375 patients were included in this study of which 97 children (25.9%) had significant signs of perforation. Univariate analysis showed that age, duration of complaints, temperature, vomiting, CRP, WBC, different findings on ultrasound and the diameter of the appendix were good predictors of a perforated appendicitis. The final multivariate prediction model included temperature, CRP, clearly visible appendix and free fluids on ultrasound and diameter of the appendix and resulted in an area under the curve (AUC) of 0.91 showing sensitivity and specificity of respectively 85.2% and 81.2%. This prediction model can be used for identification of 'high-risk' children for a perforated appendicitis and might be helpful to prevent complications and longer hospitalization by bringing these children to theater earlier. Copyright © 2016 Elsevier Inc. All rights reserved.

Management of perforated peptic ulcer in patients at a teaching hospital.

PubMed

Bin-Taleb, Ali K; Razzaq, Riyadh A; Al-Kathiri, Zaki O

2008-02-01

To explore and analyze the current status in management of patients with perforated peptic ulcers (PPU). A retrospective study carried out at the Surgical Department, Al-Gamhouria Teaching Hospital, Aden, Yemen. Patients admitted with perforated benign peptic ulcers from January 1997 to December 2006 were included in the study. A total of 156 patients, 138 (88.5%) male and 18 (11.5%) female, with an overall mean age of 39.08 years (range 14-75 years) and a higher frequency of PPU was noted in patients 21-40 years (58.3%). The perforated duodenal ulcer and perforated gastric ulcer ratio was 4.38:1. The mean time of presentation was 16.5 hours, and operative intervention after admission was 5.25 hours. Simple perforation closure was used in 91.7% of the patients. Postoperative complication rate was 41% (statistically significant in cases admitted later than 12 hours), wound sepsis making the majority at 55.2%, 6 deaths (3.9%), the correlation with presentation time was not significant. The overall mean post-operative hospitalization period was 12.76 days; 14.7% of the patients stayed more than 3 weeks. Younger patients (21-40 years) were frequently affected. Emphasis should be placed on shortening the time to surgery. Simple closure remains the selected treatment in the majority of patients. Overall post-operative mortality was low (3.9%). Improving the surgical skills, wound care, administrative regulations, hospital environment, and equipment are needed to reduce the high rate of complications.

Post-polypectomy electrocoagulation syndrome: a rare cause of acute abdominal pain

PubMed Central

Jehangir, Asad; Bennett, Kyle M.; Rettew, Andrew C.; Fadahunsi, Opeyemi; Shaikh, Bilal; Donato, Anthony

2015-01-01

While generally safe, the most feared complication of colonoscopy is perforation of the colon, occurring in nearly 1 in 1,000 procedures, and is more common when polypectomy is performed and electrocautery is used. Less commonly known is the post-polypectomy electrocoagulation syndrome, a transmural burn of the colon which mimics the signs and symptoms of perforation as well as the time course, but follows a benign course and can be treated conservatively. PMID:26486121

Spontaneous acalculous gallbladder perforation in a man secondary to chemotherapy and radiation: A rare case report.

PubMed

Zhang, Jungang; Shen, Guoliang; Shi, Ying; Zhang, Chengwu; Hong, Defei; Jin, Li; Yang, Hongguo; Sun, Wei; Cai, Hanhui; Hu, Zhiming; Wu, Weiding

2018-05-01

Gallbladder perforation is a serious clinical condition and associated with high morbidity and mortality. A definitive diagnosis is contentious before surgery. We herein report a case of perforation of the gallbladder neck secondary to chemotherapy and radiation for nasopharyngeal carcinoma patient. Gallbladder perforation secondary to chemotherapy and radiation. To decrease the mortality associated with gallbladder perforation, Laparoscopic cholecystectomy and peritoneal lavage were performed followed for gallbladder perforation patient because of chemotherapy and radiation. The patient recovered fully without serious complication and discharged on the 10th postoperative day. A pathological examination of the resected gallbladder revealed cholecystitis in the thinning of the neck. Early diagnosis and surgical intervention of gallbladder perforation in relation to asopharyngeal carcinoma chemotherapy and radiation are of prime importance. The laparoscopic procedure is safe and feasible in the selected patients.

[Liver Abscess Secondary to Perforation after Duodenal Endoscopic Resection].

PubMed

Choi, Seung Ho; Kim, Su Jin; Kang, Dae Hwan; Kim, Hyung Wook; Choi, Cheol Woong; Kim, Tae Un; Lee, Jeong Seok; Ko, Ji Hwan

2018-05-25

Duodenal perforation is a complication of endoscopic mucosal resection. Liver abscess secondary to iatrogenic perforation is extremely rare. A 43-year-old female visited the hospital to remove a sub-epithelial tumor on the duodenal bulb. After endoscopic mucosal resection with band ligation, duodenal perforation occurred. Endoscopic closure was performed successfully using a clipping device to manage duodenal perforation. After 4 weeks, the patient visited our outpatient clinic due to abdominal pain and fever. Abdominal computed tomography showed liver abscess that involved segment three. Liver abscess was resolved with a 10-week antibiotic treatment. To the best of our knowledge, no case of liver abscess secondary to duodenal perforation by endoscopic resection was reported to date in Korea. Here, we report a case of liver abscess caused by a duodenal perforation after endoscopic mucosal resection.

Data resource profile: Pathways to Health and Social Equity for Children (PATHS Equity for Children).

PubMed

Nickel, Nathan C; Chateau, Dan G; Martens, Patricia J; Brownell, Marni D; Katz, Alan; Burland, Elaine M J; Walld, Randy; Hu, Mingming; Taylor, Carole R; Sarkar, Joykrishna; Goh, Chun Yan

2014-10-01

The PATHS Data Resource is a unique database comprising data that follow individuals from the prenatal period to adulthood. The PATHS Resource was developed for conducting longitudinal epidemiological research into child health and health equity. It contains individual-level data on health, socioeconomic status, social services and education. Individuals' data are linkable across these domains, allowing researchers to follow children through childhood and across a variety of sectors. PATHS includes nearly all individuals that were born between 1984 and 2012 and registered with Manitoba's universal health insurance programme at some point during childhood. All PATHS data are anonymized. Key concepts, definitions and algorithms necessary to work with the PATHS Resource are freely accessible online and an interactive forum is available to new researchers working with these data. The PATHS Resource is one of the richest and most complete databases assembled for conducting longitudinal epidemiological research, incorporating many variables that address the social determinants of health and health equity. Interested researchers are encouraged to contact [mchp_access@cpe.umanitoba.ca] to obtain access to PATHS to use in their own programmes of research. © The Author 2014. Published by Oxford University Press on behalf of the International Epidemiological Association.

The experimental determination of the coefficient of hydraulic resistance of a perforated plate with a layer of balls adjoining to it

NASA Astrophysics Data System (ADS)

Smorchkova, Yu V.; Varava, A. N.; Dedov, A. V.; Zakharenkov, A. V.; Komov, A. T.

2017-10-01

The results of an experimental study of the hydrodynamics of a perforated plate with a layer of balls adjoining to it are presented herein. The experiments were carried out in the fluid flow range from 0.1 to 0.6 kg/s, at a fluid temperature of 19 °C.

Type 1 free perforation of the gallbladder.

PubMed Central

Harland, C; Mayberry, J F; Toghill, P J

1985-01-01

A series of 4 cases of free perforation of the gallbladder into the peritoneal cavity associated with peritonitis are reported. Two were diagnosed at laparotomy and 2 at post-mortem. The 3 patients who died were men who were either elderly or had serous concomitant diseases, including diabetes, atherosclerosis or alcoholism. The sole survivor was a fit young woman. PMID:4045903

Retention strength of impression materials to a tray material using different adhesive methods: an in vitro study.

PubMed

Marafie, Yousef; Looney, Stephen; Nelson, Steven; Chan, Daniel; Browning, William; Rueggeberg, Frederick

2008-12-01

A new self-stick adhesive system has been purported to eliminate the need to use chemical adhesives with plastic impression trays; however, no testing has confirmed the claim. The purpose of this study was to compare the in vitro retentive strength of impression materials to plastic substrates having conventional adhesive (CA) or the self-stick adhesive system, with and without mechanical retention. Three types of impression materials (irreversible hydrocolloid (IH), vinyl polysiloxane (VPS), and polyether (PE)) were applied to polystyrene disc-shaped surfaces (33.68 cm(2)) that were held on the arms of a universal testing machine. The appropriate CA or the self-stick adhesive system (Self-Stick Dots) (SSD) was applied to the plates, which had either no mechanical retention, or equally spaced mechanical perforations (n=4). An in vivo pilot test determined the appropriate rate of plate separation. Plates with impression material were lowered to provide 4 mm of space, the material set, and plates were separated using the appropriate speed. Force at first separation was divided by plate area (peak stress). Five replications per test condition were made, and results were analyzed using ANOVA and Bonferroni-adjusted t tests (alpha=.05). Within each impression material/test combination, stress using SSD was significantly lower than CA (P<.05). Mechanical retention did not always provide significantly greater strength. The combination of mechanical retention and CA yielded the highest strength within each material type, except for PE, for which nonmechanical and CA strength did not differ from that of mechanical and CA. Use of the self-stick adhesive system provided significantly lower retentive strength to plastic tray material than chemical adhesives for irreversible hydrocolloid, vinyl polysiloxane, and polyether.

Iatrogenic Aortic Valve Perforation after Ventricular Septal Defect Repair

PubMed Central

Ren, Chonglei; Wang, Mingyan; Wang, Yao; Gao, Changqing

2017-01-01

Iatrogenic aortic valve (AV) perforation during non-aortic cardiac operations is a rare complication. The suture-related inadvertent injury to an AV leaflet can produce leaflet perforation with aortic regurgitation after ventricular septal defect repair (VSDR). We report three consecutive patients who had iatrogenic aortic leaflet perforation during VSDR in other hospitals and referred to our hospital for reoperation. In all three cases, the perforated AV leaflets were preserved and repaired by autologous pericardial patch or direct local closure. PMID:29057770

Treating a novel plasticity defect rescues episodic memory in Fragile X model mice

PubMed Central

Wang, Weisheng; Cox, Brittney M.; Jia, Yousheng; Le, Aliza A.; Cox, Conor D.; Jung, Kwang M.; Hou, Bowen; Piomelli, Daniele; Gall, Christine M.; Lynch, Gary

2017-01-01

Episodic memory, a fundamental component of human cognition, is significantly impaired in autism. We report the first evidence for this problem in the Fmr1-knockout (KO) mouse model of Fragile X syndrome and describe potentially treatable underlying causes. The hippocampus is critical for the formation and use of episodes, with semantic (cue identity) information relayed to the structure via the lateral perforant path (LPP). The unusual form of synaptic plasticity expressed by the LPP (lppLTP) was profoundly impaired in Fmr1-KOs relative to wild type mice. Two factors contributed to this defect: i) reduced GluN1 subunit levels in synaptic NMDA receptors and related currents, and ii) impaired retrograde synaptic signaling by the endocannabinoid 2-archadonolglycerol (2-AG). Studies using a novel serial cue paradigm showed that episodic encoding is dependent on both the LPP and the endocannabinoid receptor CB1, and is strikingly impaired in Fmr1-KOs. Enhancing 2-AG signaling rescued both lppLTP and learning in the mutants. Thus, two consequences of the Fragile-X mutation converge on plasticity at one site in hippocampus to prevent encoding of a basic element of cognitive memory. Collectively, the results suggest a clinically plausible approach to treatment. PMID:29133950

Peptic ulcer complications requiring surgery: what has changed in the last 50 years in Turkey.

PubMed

Güzel, Hakan; Kahramanca, Sahin; Şeker, Duray; Özgehan, Gülay; Tunç, Gündüz; Küçükpınar, Tevfik; Kargıcı, Hülagü

2014-04-01

The incidence and prevalence of peptic ulcer disease has decreased in recent years, but it is not so easy to make the same conclusion when complications of peptic ulcer are taken into consideration. The aim of this study is to determine the time trends in complicated peptic ulcer disease and to state the effects of H2 receptor blockers, proton pump inhibitors (PPI), and H. pylori eradication therapies on these complications. This study retrospectively evaluated the patients who were operated on for complications (perforation, bleeding, and obstruction) of peptic ulcer for the last 50 years. Patients were grouped into four groups (G1-G4) according to the dates in which H2 receptor blockers, PPIs, and eradication regimens for H. pylori were introduced The time periods that were studied were: (G1) 1962-1980, (G2) 1981-1990, (G3) 1991-1997, and (G4) 1998-2012. In total, 2953 patients were operated on for complications of peptic ulcer disease, of which 86% of the patients were male. In G1, perforation and obstruction were significantly the most frequent complications (p<0.001), followed by bleeding. In groups G2 and G3, obstruction was still the most frequent complication requiring surgery (p<0.001). In G2 and G3, obstruction was followed by perforation and bleeding, respectively. In G4, perforation was significantly the most frequent complication (p<0.001). From 1962 to 1990 obstruction was the most common complication requiring surgery. In the last decade, perforation became the most common complication. In contrast to reports in the literature, bleeding was the least common complication requiring surgery in Turkey.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mei Teh, Bing, E-mail: bing.teh@earscience.org.au; Ear Science Institute Australia, Subiaco, WA; Department of Otolaryngology, Head, Neck and Skull Base Surgery, Sir Charles Gairdner Hospital, Nedlands, WA

Tympanic membrane perforations are common and represent a management challenge to clinicians. Current treatments for chronic perforations involve a graft surgery and require general anaesthesia, including associated costs and morbidities. Bioactive molecules (e.g. growth factors, cytokines) play an important role in promoting TM wound healing following perforation and the use of growth factors as a topical treatment for tympanic membrane perforations has been suggested as an alternative to surgery. However, the choice of bioactive molecules best suited to promote wound healing has yet to be identified. We investigated the effects of hyaluronic acid, vitronectin, TGF-α, IL-24 and their combinations onmore » migration, proliferation and adhesion of cultured human tympanic membrane-derived keratinocytes (hTM), in addition to their possible mechanisms of action. We found that TGF-α, TGF-α/HA and TGF-α/IL-24 promoted wound healing by significantly increasing both migration and proliferation. TGF-α and/or HA treated cells showed comparable cell–cell adhesion whilst maintaining an epithelial cell phenotype. With the use of receptor binding inhibitors for ErbB1 (AG1478) and CD44 (BRIC235), we revealed that the activation of ErbB1 is required for TGF-α/HA-mediated migration and proliferation. These results suggest factors that may be incorporated into a tissue-engineered membrane or directly as topical treatment for tympanic membrane perforations and hence reduce the need for a surgery. - Highlights: ► TGF-α, TGF-α/HA and TGF-α/IL-24 improved hTM keratinocyte migration and proliferation. ► TGF-α and/or HA maintained epithelial cell phenotype. ► TGF-α/HA-mediated migration and proliferation requires activation of ErbB1 receptor.« less

Time-of-Day and Appendicitis: Impact on Management and Outcomes

PubMed Central

Drake, Frederick Thurston; Mottey, Neli E.; Castelli, Anthony A.; Florence, Michael G.; Johnson, Morris G.; Steele, Scott R.; Thirlby, Richard C.; Flum, David R.

2017-01-01

Background Observational research has shown that delayed presentation is associated with perforation in appendicitis. Many factors that impact the ability to present for evaluation are influenced by time-of-day; for example, child care, work, transportation, and primary care office hours. Our objective was to evaluate for an association between care processes or clinical outcomes and presentation time. Methods Prospective cohort of 7,548 adults undergoing appendectomy at 56 hospitals across Washington State. Relative to presentation time, patient characteristics, time to surgery, imaging use, negative appendectomy (NA), and perforation were compared using univariate and multivariate methodologies. Results Overall, 63% of patients presented between noon and midnight. More men presented in the morning; however, race, insurance status, co-morbid conditions, and WBC count did not differ by presentation time. Daytime presenters (6AM-6PM) were less likely to undergo imaging (94% vs. 98% p<0.05) and had a nearly 50% decrease in median pre-operative time (6.0h vs. 8.7h p<0.001). Perforation significantly differed by time-of-day. Patients who presented during the workday (9AM-3PM) had a 30% increase in odds of perforation compared to early morning/late night presenters (adjusted OR 1.29, 95%CI 1.05–1.59). NA did not vary by time-of-day. Conclusions Most patients with appendicitis presented in afternoon/evening. Socioeconomic characteristics did not vary with time-of-presentation. Patients who presented during the workday more often had perforated appendicitis compared to those who presented early morning or late night. Processes of care differed (both time-to-surgery and imaging use). Time-of-day is associated with patient outcomes, process of care, and decisions to present for evaluation; this has implications for surgical workforce planning and quality improvement efforts. PMID:27592212

Magnetic resonance angiography in perforator flap breast reconstruction

PubMed Central

Levine, Joshua L.

2016-01-01

Magnetic resonance angiography (MRA) is an extremely useful preoperative imaging test for evaluation of the vasculature of donor tissue to be used in autologous breast reconstruction. MRA has sufficient spacial resolution to reliably visualize 1 mm perforating vessels and to accurately locate vessels in reference to a patient’s anatomic landmarks without exposing patients to ionizing radiation or iodinated contrast. The use of a blood pool contrast agent and the lack of radiation exposure allow multiple studies of multiple anatomic regions in one examination. The following article is a detailed description of our MRA protocol developed with our radiologists with examples that illustrate the utility of MRA in perforator flap breast reconstruction. PMID:27047787

Low-energy plasma-cathode electron gun with a perforated emission electrode

NASA Astrophysics Data System (ADS)

Burdovitsin, Victor; Kazakov, Andrey; Medovnik, Alexander; Oks, Efim; Tyunkov, Andrey

2017-11-01

We describe research of influence of the geometric parameters of perforated electrode on emission parameters of a plasma cathode electron gun generating continuous electron beams at gas pressure 5-6 Pa. It is shown, that the emission current increases with increasing the hole diameters and decreasing the thickness of the perforated emission electrode. Plasma-cathode gun with perforated electron can provide electron extraction with an efficiency of up to 72 %. It is shown, that the current-voltage characteristic of the electron gun with a perforated emission electrode differs from that of similar guns with fine mesh grid electrode. The plasma-cathode electron gun with perforated emission electrode is used for electron beam welding and sintering.

Optimal conditions for tissue perforation using high intensity focused ultrasound

NASA Astrophysics Data System (ADS)

Mochizuki, Takashi; Kihara, Taizo; Ogawa, Kouji; Tanabe, Ryoko; Yosizawa, Shin; Umemura, Shin-ichiro; Kakimoto, Takashi; Yamashita, Hiromasa; Chiba, Toshio

2012-10-01

To perforate tissue lying deep part in body, a large size transducer was assembled by combining four spherical-shaped transducers, and the optimal conditions for tissue perforation have studied using ventricle muscle of chicken as a target. The ex vivo experiments showed that ventricle muscle was successfully perforated both when it was exposed to High Intensity Focused Ultrasound (HIFU) directly and when it was exposed to HIFU through atrial muscle layer. Moreover, it was shown that calculated acoustic power distributions are well similar to the perforation patterns, and that the acoustic energy distributes very complexly near the focus. Lastly, perforation on the living rabbit bladder wall was demonstrated as a preliminary in vivo experiment.

A case report of esophageal perforation: Complication of nasogastric tube placement

PubMed Central

Isik, Arda; Firat, Deniz; Peker, Kemal; Sayar, Ilyas; Idiz, Oguz; Soytürk, Mehmet

2014-01-01

Patient: Male, 70 Final Diagnosis: Esophageal perforation Symptoms: Abdominal pain • nausea • vomiting Medication: — Clinical Procedure: — Specialty: Surgery Objective: Unusual clinical course Background: Esophageal perforation is a well-defined and severe clinical condition. There are several etiologies of esophagus perforation. Case Report: We report the case of a 70-year-old Caucasian man who underwent an emergency cholecystectomy due to acute cholecystitis. Two days after surgery, his condition deteriorated. Thorax computerized tomography revealed an esophageal perforation. Conclusions: Esophageal perforation due to nasogastric application is relatively rare but the consequences are potentially serious. The anatomy of the upper gastrointestinal system should be understood by all healthcare professionals involved in the treatment. PMID:24803977

A novel sol-gel-derived calcium silicate cement with short setting time for application in endodontic repair of perforations

PubMed Central

Lee, Bor-Shiunn; Lin, Hong-Ping; Chan, Jerry Chun-Chung; Wang, Wei-Chuan; Hung, Ping-Hsuan; Tsai, Yu-Hsin; Lee, Yuan-Ling

2018-01-01

Mineral trioxide aggregate (MTA) is the most frequently used repair material in endodontics, but the long setting time and reduced mechanical strength in acidic environments are major shortcomings. In this study, a novel sol-gel-derived calcium silicate cement (sCSC) was developed using an initial Ca/Si molar ratio of 3, with the most effective mixing orders of reactants and optimal HNO3 catalyst volumes. A Fourier transform infrared spectrometer, scanning electron microscope with energy-dispersive X-ray spectroscopy, and X-ray powder diffractometer were used for material characterization. The setting time, compressive strength, and microhardness of sCSC after hydration in neutral and pH 5 environments were compared with that of MTA. Results showed that sCSC demonstrated porous microstructures with a setting time of ~30 min, and the major components of sCSC were tricalcium silicate, dicalcium silicate, and calcium oxide. The optimal formula of sCSC was sn200, which exhibited significantly higher compressive strength and microhardness than MTA, irrespective of neutral or pH 5 environments. In addition, both sn200 and MTA demonstrated good biocompatibility because cell viability was similar to that of the control. These findings suggest that sn200 merits further clinical study for potential application in endodontic repair of perforations. PMID:29386894

A novel sol-gel-derived calcium silicate cement with short setting time for application in endodontic repair of perforations.

PubMed

Lee, Bor-Shiunn; Lin, Hong-Ping; Chan, Jerry Chun-Chung; Wang, Wei-Chuan; Hung, Ping-Hsuan; Tsai, Yu-Hsin; Lee, Yuan-Ling

2018-01-01

Mineral trioxide aggregate (MTA) is the most frequently used repair material in endodontics, but the long setting time and reduced mechanical strength in acidic environments are major shortcomings. In this study, a novel sol-gel-derived calcium silicate cement (sCSC) was developed using an initial Ca/Si molar ratio of 3, with the most effective mixing orders of reactants and optimal HNO 3 catalyst volumes. A Fourier transform infrared spectrometer, scanning electron microscope with energy-dispersive X-ray spectroscopy, and X-ray powder diffractometer were used for material characterization. The setting time, compressive strength, and microhardness of sCSC after hydration in neutral and pH 5 environments were compared with that of MTA. Results showed that sCSC demonstrated porous microstructures with a setting time of ~30 min, and the major components of sCSC were tricalcium silicate, dicalcium silicate, and calcium oxide. The optimal formula of sCSC was sn200, which exhibited significantly higher compressive strength and microhardness than MTA, irrespective of neutral or pH 5 environments. In addition, both sn200 and MTA demonstrated good biocompatibility because cell viability was similar to that of the control. These findings suggest that sn200 merits further clinical study for potential application in endodontic repair of perforations.

Robotic-Assisted Inferior Vena Cava Filter Retrieval.

PubMed

Owji, Shahin; Lu, Tony; Loh, Thomas M; Schwein, Adeline; Lumsden, Alan B; Bismuth, Jean

2017-01-01

Although anticoagulation remains the mainstay of therapy for patients with venous thromboembolism, guidelines recommend the use of inferior vena cava (IVC) filters in those who fail anticoagulation or have contraindications to its use. Short-term use of filters has proven effective in reducing the rate of pulmonary embolism. However, their extended use is associated with a variety of complications such as thrombosis, filter migration, or caval perforation, thus making a case for timely filter retrieval. This is the case of a 68-year-old female with a history of chronic oral anticoagulation use for multiple deep venous thrombi (DVT) and pulmonary emboli (PE) who required cervical and thoracic spinal intervention for spondylosis and foramina stenosis. Given her increased risk of recurrent DVT and PE perioperatively, we elected to place a Cook Celect ™ IVC filter (Cook Medical, Bloomington, IN) after oral anticoagulation was stopped for the procedure. Her treatment course was prolonged due to wound-healing complications. We elected to use the Magellan Robotic Catheter System (Hansen Medical, Mountain View, CA) for filter retrieval when she presented 6 months later with caval perforation from the filter struts. With its ease of use, superior mechanical stability, and maneuverability, robot-assisted IVC filter retrieval may be a safer and more reliable substitute for traditional navigation techniques when presented with challenging filter retrievals.

Knitted outer gloves in primary hip and knee arthroplasty.

PubMed

Tanner, J; Wraighte, P; Howard, P

2006-01-01

A randomised trial was carried out to determine the rate of perforation to inner gloves when comparing latex with knitted gloves during hip and knee arthroplasty. Members of the surgical team were randomised to wear either two pairs of latex gloves (standard double gloving) or a knitted glove on top of a latex glove. In addition, participants completed a visual analogue assessment of their overall satisfaction with the gloves. A total of 406 inner gloves were tested for perforations over a four-month period: 23% of inner gloves were perforated when latex outer gloves were used and 6% of inner gloves were perforated when knitted outer gloves were used. In total, there were 64 perforations to the inner gloves; only one of these perforations was detected by the glove wearer. Wearing knitted outer gloves during hip and knee arthroplasty statistically significantly reduces the risk of perforation to inner latex gloves (p<0.0001).

Gallbladder perforation complicating typhoid fever: report of two cases.

PubMed

Gali, B M; Ali, N; Agbese, G O; Duna, V D; Dawha, S D; Ismai, G I; Mohammed, M

2011-01-01

Gallbladder perforation (GBP) is rare and as a complication of typhoid fever is extremely rare. We present two consecutive patients with GBP diagnosed incidentally at laparotomy. Information on the management of two patients with gallbladder perforation seen at Federal Medical Centre Azare in June and October 2008 was extracted from their case records. The two patients were both males aged 13 years and 16 years. They both presented with high fever of more than 2 weeks duration; and abdominal pain and distension. Both patients had features of generalised peritonitis. Pre-operative diagnoses of typhoid enteric perforation were made based on a positive Widal test. Intra-operative findings however, were that of bile peritonitis and gallbladder perforation. Both had cholecystectomy. Culture of the bile aspirate yielded Salmonella typhi. Gallbladder perforation secondary to typhoid fever should be considered as a differential diagnosis in patients with suspected typhoid enteric perforation in typhoid fever endemic region.

Inflow performance relationship for perforated wells producing from solution gas drive reservoir

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sukarno, P.; Tobing, E.L.

1995-10-01

The IPR curve equations, which are available today, are developed for open hole wells. In the application of Nodal System Analysis in perforated wells, an accurate calculation of pressure loss in the perforation is very important. Nowadays, the equation which is widely used is Blount, Jones and Glaze equation, to estimate pressure loss across perforation. This equation is derived for single phase flow, either oil or gas, therefore it is not suitable for two-phase production wells. In this paper, an IPR curve equation for perforated wells, producing from solution gas drive reservoir, is introduced. The equation has been developed usingmore » two phase single well simulator combine to two phase flow in perforation equation, derived by Perez and Kelkar. A wide range of reservoir rock and fluid properties and perforation geometry are used to develop the equation statistically.« less

The value of dynamic infrared thermography (DIRT) in perforatorselection and planning of free DIEP flaps.

PubMed

de Weerd, Louis; Weum, Sven; Mercer, James B

2009-09-01

The aim of this paper is to evaluate dynamic infrared thermography (DIRT) as a technique to assist in preoperative perforator selection and planning of free deep inferior epigastric perforator (DIEP) flaps. Twenty-seven patients, scheduled for secondary autologous breast reconstruction with either a free DIEP flap or superficial inferior epigastric artery flap, were included in this prospective clinical study. Preoperative mapping of perforators was performed with a hand-held Doppler and DIRT. A multidetector computer tomography scan was additionally carried out in the last 8 patients. In 23 patients a DIEP flap was used. The perforator as selected from DIRT was a suitable perforator in all DIEP flaps. The location and quality of the selected perforator from DIRT corresponded well with the multidetector computer tomography scan results. Preoperative perforator selection and planning of DIEP flaps is facilitated with the use of DIRT. The technique is noninvasive and easy to use.

Dimensions of stabident intraosseous perforators and needles.

PubMed

Ramlee, R A; Whitworth, J

2001-09-01

Problems can be encountered inserting intraosseous injection needles through perforation sites. This in vitro study examined the variability and size compatibility of Stabident intraosseous injection components. The diameters of 40 needles and perforators from a single Stabident kit were measured in triplicate with a toolmakers microscope. One-way ANOVA revealed that mean needle diameter (0.411 mm) was significantly narrower than mean perforator diameter (0.427 mm) (p < 0.001). A frequency distribution plot revealed that needle diameter followed a normal distribution, indicating tight quality control during manufacture. The diameter of perforators was haphazardly distributed, with a clustering of 15% at the lower limit of the size range. However on no occasion was the diameter of a perforator smaller than that of an injection needle. We conclude that components of the Stabident intraosseous anaesthetic system are size-compatible, but there is greater and more haphazard variability in the diameter of perforators than injection needles.

Free sural artery perforator flap: An occasional gift in oral cavity reconstruction.

PubMed

Pease, Natalie L; Davies, Andrew; Townley, William A

2016-07-01

The medial sural artery perforator (MSAP) flap is becoming a popular strategy for reconstructing intraoral defects. We present a case in which no MSAPs were present, however, a perforator-based calf flap was successfully raised on the sural artery and used for tongue reconstruction. A corresponding anatomic study was undertaken to establish if this finding was reproducible. A 58-year-old woman underwent left hemiglossectomy for a squamous cell carcinoma of the tongue. Subsequently, 6 fresh frozen cadaveric limbs were dissected examining the blood supply of the posterior calf skin. The sural artery perforator (SAP) flap successfully reconstructed the defect. Our cadaveric study similarly demonstrated a septocutaneous SAP supplying the posterior calf skin in 1 of 6 limbs. SAPs allow a favorable flap dissection, as opposed to the musculocutaneous course of MSAPs. Our findings provide further evidence of the versatility of the calf donor site. © 2016 Wiley Periodicals, Inc. Head Neck 38: E2454-E2456, 2016. © 2016 Wiley Periodicals, Inc.

Perforator Flaps after Excision of Large Epidermal Cysts in the Buttocks

PubMed Central

Kim, Sang Wha; Yang, Seong Hyeok; Kim, Jeong Tae

2014-01-01

Background Epidermal cysts are commonly occurring masses usually less than 5 cm in diameter, but in predisposed patients, epidermal cysts can grow relatively large due to chronic infection. Methods From June 2002 to July 2010, 17 patients received 19 regional perforator-based island flaps to cover defects due to the excision of large epidermal cysts (diameter >5 cm) in the buttocks. Eight patients had diabetes, and seven had rheumatoid arthritis. The pedicles were not fully isolated to prevent spasms or twisting. Results All the flaps survived completely, except for one case with partial necrosis of the flap, which necessitated another perforator-based island flap for coverage. There were two cases of wound dehiscence, which were re-closed after meticulous debridement. There were no recurrences of the masses during follow-up periods of 8.1 months (range, 6-12 months). Conclusions In patients with large epidermal cysts and underlying medical disorders, regional perforator-based island flaps can be the solution to coverage of the defects after excision. PMID:24665422

Application of Layered Perforation Profile Control Technique to Low Permeable Reservoir

NASA Astrophysics Data System (ADS)

Wei, Sun

2018-01-01

it is difficult to satisfy the demand of profile control of complex well section and multi-layer reservoir by adopting the conventional profile control technology, therefore, a research is conducted on adjusting the injection production profile with layered perforating parameters optimization. i.e. in the case of coproduction for multi-layer, water absorption of each layer is adjusted by adjusting the perforating parameters, thus to balance the injection production profile of the whole well section, and ultimately enhance the oil displacement efficiency of water flooding. By applying the relationship between oil-water phase percolation theory/perforating damage and capacity, a mathematic model of adjusting the injection production profile with layered perforating parameters optimization, besides, perforating parameters optimization software is programmed. Different types of optimization design work are carried out according to different geological conditions and construction purposes by using the perforating optimization design software; furthermore, an application test is done for low permeable reservoir, and the water injection profile tends to be balanced significantly after perforation with optimized parameters, thereby getting a good application effect on site.

Quality changes of 'Sanguinello' oranges wrapped with different plastic films under simulated marketing conditions.

PubMed

D'Aquino, S; Malinconico, M; Avella, M; Di Lorenzo, M L; Mura; Palma, A

2013-01-01

Chemical and eating quality of citrus fruit changes slowly after harvest, and quality alteration is mainly due to shrinkage, loss of firmness, excessive weight loss and decay rather than a reduction of nutritional value and taste features. Film wrapping may be a suitable means to reduce transpiration and preserve market quality provided film permeability to gases does not lead to: 1) a reduction of in-package O2 partial pressure at a point that would induce anaerobic respiration; 2) an increase of CO2 concentration to toxic levels. This experiment was carried out to study quality changes of 'Sanguinello' oranges treated or not treated with 500 mg/L imazalil (IMZ) and wrapped with continuous, macro- or micro-perforated polyolefinic films. Wrapped and no-wrapped fruit were stored at 20 degrees C and 60% RH for 20 or 30 days. In-package gas composition of the macro-perforated film showed no significant difference compared to air composition, while in-package partial pressure of CO2 and O2 ranged between 4 (continuous film) and 9.8 kPa (micro-perforated films), and 14.8 (continuous film) and 5 kPa (micro-perforated films), respectively. After 30 days of storage weight loss in fruit wrapped with the macro-perforated film was (4.3%) slightly lowerthan un-packed fruit (5%), while in all other packages weight loss never exceeded 0.7%.Quality changes were quite stable over storage in all treatments, although slight but significantly lower levels of total soluble solids and ascorbic acid were detected in micro-perforated films with the lowest degree of perforation. However, the sensory analysis denoted a remarkable decrease of firmness in un-wrapped or wrapped fruit with macro-perforated film, while a moderate build-up of off-flavour, which reduced the eating quality, developed in micro-perforated films. Decay ranged between 6 and 12% in not treated fruit, with the lowest incidence detected in un-wrapped fruit, whereas differences among the different films were not significant. No decay was detected in fruit treated with IMZ. 'Sanguinello' oranges can be stored under retail conditions for a month by the only means of film wrapping without important changes in chemical, eating and marketing quality provided fruit are treated with an effective fungicide to prevent decay and that in-package gas composition is not markedly changed with respect to air.

Acute perforated peptic ulcer: on clinical experience in an urban tertiary hospital in south east Nigeria.

PubMed

Ugochukwu, A I; Amu, O C; Nzegwu, M A; Dilibe, U C

2013-01-01

Acute perforated peptic ulcer is a leading cause of generalized peritonitis and its management has continued to be a challenging task in our environment. There is a paucity of published reports on acute perforated peptic ulcers in our environment. This study was conducted to evaluate the different pattern of risk factors clinical presentations, management and clinical outcome of patients with acute perforated peptic ulcer in our setting and to highlight the factors that continue to account for the high mortality and morbidity as seen here. A retrospective study where data of seventy-six (76) patients managed for generalized peritonitis due to acute peptic ulcer perforation over a five year period (January 2006-December 2010) were retrieved from medical records of Enugu State University of Science and Technology Hospital (ESUTH). The patients' biodata, clinical and operative findings and treatment outcome were extracted and analysed, after institutional ethical approval was secured. All other cases of generalized peritonitis not traceable to acute peptic ulcer perforation were excluded from the study. There were76 patients; 58 males and 18 females (M:F = 3.2:1) Their ages ranged from 20 to 80years with a mean of 39.5yr and SD ± 13.10years. Majority of the patients 49(64.4%) were 40years of age and below and only 24 (31.6%) had a previous history suggestive of chronic peptic ulcer disease. Twenty five (32.9%) patients presented within 24 h of onset of symptoms of perforation with a mortality of 8.0%. Slightly more than half of our patients 39(51.3%) presented between 24 and 48 h with mortality of 17.9%. Twelve patients (15.8%) presented between 48 and 72 h and the mortality in this group was 58.3%. The latter two groups accounted for most of the mortality in our series. All perforations were anterior perforations within the first 2.5 cm of the duodenum and all had simple closure with pedicled omental patch and peritoneal toilet with copious volumes of warm normal saline. Postoperatively all received Helicobacter pylori eradication therapy and proton pump inhibitors for at least two months. Patient groups who presented early had low mortality rates, but patient groups who presented late had higher mortality rates. Overall mortality was 21%. Copyright © 2013. Published by Elsevier Ltd.

Reconstruction of cubital fossa skin necrosis with radial collateral artery perforator-based propeller flap (RCAP).

PubMed

Chaput, B; Gandolfi, S; Ho Quoc, C; Chavoin, J-P; Garrido, I; Grolleau, J-L

2014-02-01

In recent years, perforator flaps have become an indispensable tool for the reconstruction process. Most recently, "propeller" perforator flaps allow each perforator vessels to become a flap donor site. Once the perforator of interest is identified by acoustic Doppler, the cutaneous or fascio-cutaneous island is designed and then customized according to the principle of "perforasome". So, the flap can be rotated such a propeller, up to 180°. Ideally the donor site is self-closing, otherwise it can be grafted at the same time. Through a skin necrosis secondary to a contrast medium extravasation of the cubital fossa in a 47-year-old man, we describe the use of propeller perforator flap based on a perforator of the radial collateral artery (RCAP). The perforator was identified preoperatively by acoustic Doppler then the flap was adapted bespoke to cover the loss of substance. Ultimately, the result was very satisfying. Well experienced for lower-extremity reconstruction, perforator-based propeller flap are still few reported for upper limb. It is likely that in the future, propeller flap supersede in many indication not only free flaps and locoregional flaps but also, leaving no room for uncertainties of the vascular network, the classic random flaps. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

Peritonitis: 10 years' experience in a single surgical unit.

PubMed

Agarwal, Nitin; Saha, Sudipta; Srivastava, Anurag; Chumber, Sunil; Dhar, Anita; Garg, Sanket

2007-01-01

Peritonitis secondary to gut perforation is still one of the commonest surgical emergencies in India and is associated with high morbidity and mortality. The present study examines the aetiology and outcome of peritonitis cases operated on in our surgical unit, and compares our findings with those of previous studies performed between 1981 and 1991. A retrospective study of 260 peritonitis patients operated on in a single surgical unit from 1995 to 2006 was done and data involving clinical presentation, operative findings and post-operative course were studied and analysed. Causes of peritonitis were small bowel perforation (96 ileal, 17 jejunal), peptic perforation (45 duodenal, 16 gastric), appendicular perforation (36), primary peritonitis (8), and others (42). The incidence of major complications was 25% (burst-11%, leak-5%, intraabdominal abscess-5%, multi-organ failure-6.5%). The overall mortality was 10%. High mortality was observed in jejunal, gall bladder and liver abscess perforation cases (> 20%). Histopathological evaluation (143 specimens) revealed tuberculosis in 42 (mostly small bowel), malignancy in 8, and inflammation in the rest. Comparisons with a similar study carried out in the same unit and published in 1995 revealed similar demographic features and mortality, but a change in the most common cause (peptic ulcer perforation to small bowel perforation), and an increased performance of enterostomy compared with primary repair in small bowel perforation and a decrease in the leak rate (13% to 4%). Small bowel perforation is the commonest form of perforation and the mortality rate associated with peritonitis remains unchanged.

Perforated hollow-core optical waveguides for on-chip atomic spectroscopy and gas sensing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Giraud-Carrier, M., E-mail: mgeecee@byu.edu; Hill, C.; Decker, T.

2016-03-28

A hollow-core waveguide structure for on-chip atomic spectroscopy is presented. The devices are based on Anti-Resonant Reflecting Optical Waveguides and may be used for a wide variety of applications which rely on the interaction of light with gases and vapors. The designs presented here feature short delivery paths of the atomic vapor into the hollow waveguide. They also have excellent environmental stability by incorporating buried solid-core waveguides to deliver light to the hollow cores. Completed chips were packaged with an Rb source and the F = 3 ≥ F′ = 2, 3, 4 transitions of the D2 line in {sup 85}Rb were monitored formore » optical absorption. Maximum absorption peak depths of 9% were measured.« less

Preoperative color Doppler assessment in planning of gluteal perforator flaps.

PubMed

Isken, Tonguc; Alagoz, M Sahin; Onyedi, Murat; Izmirli, Hakki; Isil, Eda; Yurtseven, Nagehan

2009-02-01

Gluteal artery perforator flaps have gained popularity due to reliability, preservation of the muscle, versatility in flap design without restricting other flap options, and low donor-site morbidity in ambulatory patients and possibility of enabling future reconstruction in paraplegic patients. But the inconstant anatomy of the vascular plexus around the gluteal muscle makes it hard to predict how many perforators are present, what their volume of blood flow and size are, where they exit the overlying fascia, and what their course through the muscle will be. Without any prior investigations, the reconstructive surgeon could be surprised intraoperatively by previous surgical damage, scar formation, or anatomic variants.For these reasons, to confirm the presence and the location of gluteal perforators preoperatively we have used color Doppler ultrasonography. With the help of the color Doppler ultrasonography 26 patients, 21 men and 5 women, were operated between the years 2002 and 2007. The mean age of patients was 47.7 (age range: 7-77 years). All perforator vessels were marked preoperatively around the defect locations. The perforator based flap that will allow primary closure of the donor site and the defect without tension was planned choosing the perforator that showed the largest flow in color Doppler ultrasonography proximally. Perforators were found in the sites identified with color Doppler ultrasonography in all other flaps. In our study, 94.4% flap viability was ensured in 36 perforator-based gluteal area flaps. Mean flap elevation time was 31.9 minutes. We found that locating the perforators preoperatively helps to shorten the operation time without compromising a reliable viability of the perforator flaps, thus enabling the surgeon easier treatment of pressure sores.

Cost effective management of duodenal ulcers in Uganda: interventions based on a series of seven cases.

PubMed

Nzarubara, Gabriel R

2005-03-01

Our understanding of the cause and treatment of peptic ulcer disease has changed dramatically over the last couple of decades. It was quite common some years ago to treat chronic ulcers surgically. These days, the operative treatment is restricted to the small proportion of ulcer patients who have complications such as perforation. The author reports seven cases of perforated duodenal ulcers seen in a surgical clinic between 1995 and 2001. Recommendations on the criteria for selecting the appropriate surgical intervention for patients with perforated duodenal ulcer are given. To decide on the appropriate surgical interventions for patients with perforated duodenal ulcer. These are case series of 7 patients who presented with perforated duodenal ulcers without a history of peptic ulcer disease. Seven patients presented with perforated duodenal ulcer 72 hours after perforation in a specialist surgical clinic in Kampala were analyzed. Appropriate management based on these patients is suggested. These patients were initially treated in upcountry clinics for acute gastritis from either alcohol consumption or suspected food poisoning. There was no duodenal ulcer history. As a result, they came to specialist surgical clinic more than 72 hours after perforation. Diagnosis of perforated duodenal ulcer was made and they were operated using the appropriate surgical intervention. Diagnosis of hangovers and acute gastritis from alcoholic consumption or suspected food poisoning should be treated with suspicion because the symptoms and signs may mimic perforated peptic ulcer in "silent" chronic ulcers. The final decision on the appropriate surgical intervention for patients with perforated duodenal ulcer stratifies them into two groups: The previously fit patients who have relatively mild physiological compromise imposed on previously healthy organ system by the perforation can withstand the operative stress of definitive procedure. The Second category includes patients who are critically ill, who poorly tolerate any operation and hence poor surgical risks. These require urgent, adequate resuscitation and simple suture with omental patch.