Mapping a region within the 1RS.1BL translocation in common wheat affecting grain yield and canopy water status.

PubMed

Howell, Tyson; Hale, Iago; Jankuloski, Ljupcho; Bonafede, Marcos; Gilbert, Matthew; Dubcovsky, Jorge

2014-12-01

This study identifies a small distal region of the 1RS chromosome from rye that has a positive impact on wheat yield. The translocation of the short arm of rye (Secale cereale L.) chromosome one (1RS) onto wheat (Triticum aestivum L.) chromosome 1B (1RS.1BL) is used in wheat breeding programs worldwide due to its positive effect on yield, particularly under abiotic stress. Unfortunately, this translocation is associated with poor bread-making quality. To mitigate this problem, the 1RS arm was engineered by the removal and replacement of two interstitial rye segments with wheat chromatin: a distal segment to introduce the Glu-B3/Gli-B1 loci from wheat, and a proximal segment to remove the rye Sec-1 locus. We used this engineered 1RS chromosome (henceforth 1RS(WW)) to develop and evaluate two sets of 1RS/1RS(WW) near isogenic lines (NILs). Field trials showed that standard 1RS lines had significantly higher yield and better canopy water status than the 1RS(WW) NILs in both well-watered and water-stressed environments. We intercrossed the 1RS and 1RS(WW) lines and generated two additional NILs, one carrying the distal (1RS(RW)) and the other carrying the proximal (1RS(WR)) wheat segment. Lines not carrying the distal wheat region (1RS and 1RS(WR)) showed significant improvements in grain yield and canopy water status compared to NILs carrying the distal wheat segment (1RS(WW) and 1RS(RW)), indicating that the 1RS region replaced by the distal wheat segment carries the beneficial allele(s). NILs without the distal wheat segment also showed higher carbon isotope discrimination and increased stomatal conductance, suggesting that these plants had improved access to water. The 1RS(WW), 1RS(WR) and 1RS(RW) NILs have been deposited in the National Small Grains Collection.

In vivo and in vitro heterogeneity of segment length changes in the semimembranosus muscle of the toad

PubMed Central

Ahn, A N; Monti, R J; Biewener, A A

2003-01-01

Many studies examine sarcomere dynamics in single fibres or length–tension dynamics in whole muscles in vivo or in vitro, but few studies link the various levels of organisation. To relate data addressing in vitro muscle segment behaviour with in vivo whole muscle behaviour during locomotion, we measured in vivo strain patterns of muscle segments using three sonomicrometry crystals implanted along a fascicle of the semimembranosus muscle in the American toad (Bufo americanus; n = 6) during hopping. The centre crystal emitted an ultrasonic signal, while the outer crystals received the signal allowing the instantaneous measurement of lengths from two adjacent muscle segments. On the first day, we recorded from the central and distal segments. On the second day of recordings, the most distal crystal was moved to a proximal position to record from a proximal segment and the same central segment. When the toads hopped a distance of two body lengths, the proximal and central segments strained −15.1 ± 6.1 and −14.0 ± 4.9 % (i.e. shortening), respectively. Strain of the distal segment, however, was significantly lower and more variable in pattern, often lengthening before shortening during a hop. From rest length, the distal segment initially lengthened by 2.6 ± 2.0 % before shortening by 6.5 ± 3.2 % at the same hop distance. Under in vitro conditions, the central segment always shortened more than the distal segment, except when passively cycled, during which the segments strained similarly. When the whole muscle was cycled sinusoidally and stimulated phasically in vitro, the two adjacent segments strained in opposite directions over much (up to 34 %) of the cycle. These differences in strain amplitude and direction imply that two adjacent segments can not only produce and/or absorb varying amounts of mechanical energy, but can also operate on different regions of their force–length and force–velocity relationships when activated by the same neural signal. Understanding regional differences in contractile dynamics within muscles is therefore important to linking our understanding of sarcomere behaviour with whole muscle behaviour during locomotion. PMID:12717006

Protection of Distal Embolization in High-Risk Patients with Acute ST-Segment Elevation Myocardial Infarction (PREMIAR).

PubMed

Cura, Fernando A; Escudero, Alejandro Garcia; Berrocal, Daniel; Mendiz, Oscar; Trivi, Marcelo S; Fernandez, Juan; Palacios, Alejandro; Albertal, Mariano; Piraino, Ruben; Riccitelli, Miguel Angel; Gruberg, Luis; Ballarino, Miguel; Milei, Jose; Baeza, Ricardo; Thierer, Jorge; Grinfeld, Liliana; Krucoff, Mitchell; O'Neill, William; Belardi, Jorge

2007-02-01

Distal embolization may decrease myocardial reperfusion after primary percutaneous coronary intervention (PCI). Nonetheless, results of previous trials assessing the role of distal protection during primary PCI have been controversial. The Protection of Distal Embolization in High-Risk Patients with Acute ST-Segment Elevation Myocardial Infarction Trial (PREMIAR) was a prospective, randomized, controlled study designed to evaluate the role of filter-based distal protection during PCI in patients with acute ST-segment elevation myocardial infarction at high risk of embolic events (including only baseline Thrombolysis In Myocardial Infarction grade 0 to 2 flow). The primary end point was continuous monitoring of ST-segment resolution. Secondary end points included core laboratory analysis of angiographic myocardial blush, ejection fraction measured by cardiac ultrasound, and adverse cardiac events at 6 months. From a total of 194 enrolled patients, 140 subjects were randomized to PCI with or without embolic protection, and 54 were included in a registry arm due to the presence of angiographic exclusion criteria. Baseline characteristics were comparable between arms. The rate of complete ST-segment resolution (>or=70%) at 60 minutes was similar in patients treated with or without distal protection (61.2% vs 60.3%, respectively, p = 0.85). Angiographic myocardial blush (67% vs 70.7%, p = 0.73), in-hospital ejection fraction (47.4 +/- 9.9% vs 45.3 +/- 7.3%, p = 0.29), and combined end point of death, heart failure, or reinfarction at 6 months (14.3% vs 15.7%, p = 0.81) were consistently achieved in a similar proportion in the 2 groups. In conclusion, the use of filter-based distal protection is safe and effectively retrieves debris; however, such use does not translate into an improvement of myocardial reperfusion, left ventricular performance, or clinical outcomes.

Segmental analysis of renal glucose transport in young female rats.

PubMed Central

McSherry, N R; Wen, S F

1984-01-01

Free-flow micropuncture studies were performed on twenty-seven young female Sprague-Dawley rats before and after 10% extracellular volume expansion to evaluate glucose reabsorption at the accessible sites of both surface and papillary nephrons. In the distal nephron segments no significant glucose reabsorption was observed for the distal tubule and papillary collecting duct but significant difference in fractional glucose delivery was demonstrated between the bend of the Henle's loop and early distal tubule and between the late distal tubule and the base of the collecting duct. Comparison of the fractional glucose delivery within the same nephron group for both superficial and juxtamedullary nephrons indicated that glucose reabsorption occurred at some sites beyond the bend of the Henle's loop. Volume expansion inhibited glucose reabsorption in the proximal convoluted tubule, enhanced it in the segment between the late proximal and early distal tubules, but had no effect on glucose transport at further distal sites. It is concluded that, in addition to the proximal tubule, the ascending loop of Henle or cortical collecting tubule may play a role in maintaining glucose-free urine under physiological conditions. PMID:6394745

Occipital Artery Function during the Development of 2-Kidney, 1-Clip Hypertension in Rats.

PubMed

Chelko, Stephen P; Schmiedt, Chad W; Lewis, Tristan H; Robertson, Tom P; Lewis, Stephen J

2014-01-01

This study compared the contractile responses elicited by angiotensin II (AII), arginine vasopressin (AVP), and 5-hydroxytryptamine (5-HT) in isolated occipital arteries (OAs) from sham-operated (SHAM) and 2-kidney, 1-clip (2K-1C) hypertensive rats. OAs were isolated and bisected into proximal segments (closer to the common carotid artery) and distal segments (closer to the nodose ganglion) and mounted separately on myographs. On day 9, 2K-1C rats had higher mean arterial blood pressures, heart rates, and plasma renin concentrations than SHAM rats. The contractile responses to AII were markedly diminished in both proximal and distal segments of OAs from 2K-1C rats as compared to those from SHAM rats. The responses elicited by AVP were substantially greater in distal than in proximal segments of OAs from SHAM rats and that AVP elicited similar responses in OA segments from 2K-1C rats. The responses elicited by 5-HT were similar in proximal and distal segments from SHAM and 2K-1C rats. These results demonstrate that continued exposure to circulating AII and AVP in 2K-1C rats reduces the contractile efficacy of AII but not AVP or 5-HT. The diminished responsiveness to AII may alter the physiological status of OAs in vivo.

Peripheral neuropathy in Tangier disease: A literature review and assessment.

PubMed

Mercan, Metin; Yayla, Vildan; Altinay, Serdar; Seyhan, Serhat

2018-06-01

Tangier disease (TD) (OMIM#205400) is a rare cause of inherited metabolic neuropathies characterized by marked deficiency of high-density lipoproteins and accumulation of cholesterol esters in various tissue resulting from reverse cholesterol transport deficiency. We report a case of a patient with TD with multifocal demyelinating neuropathy with conduction block who presents with winging scapula, tongue, and asymmetric extremity weakness. We also present a review of all studies published from 1960 to 2017 regarding peripheral neuropathy in TD. Our search identified 54 patients with TD with peripheral neuropathy. Syringomyelia-like neuropathy subtype (52.4%) was more frequent than multifocal sensorial and motor neuropathy subtype (26.2%), focal neuropathy subtype (19.1%), and distal symmetric polyneuropathy subtype (2.4%). Splenomegaly was the most common (40.7%) clinical manifestation in these patients. The pattern of electrodiagnostic abnormalities are: (1) demyelinating abnormalities were more predominant in the upper extremities than in the lower extremities and (2) slowing of motor nerve conduction was more prominent in the intermediate segment than in distal nerve segments. The sural-sparing pattern was present in 34.6% and conduction block was present in 11.5% of the patients. Our literature review and our case showed the clinical spectrum of TD neuropathy is quite wide and that it should be considered in the differential diagnosis of non-uniform demyelinating neuropathies. © 2018 Peripheral Nerve Society.

Electric machine

DOEpatents

El-Refaie, Ayman Mohamed Fawzi [Niskayuna, NY; Reddy, Patel Bhageerath [Madison, WI

2012-07-17

An interior permanent magnet electric machine is disclosed. The interior permanent magnet electric machine comprises a rotor comprising a plurality of radially placed magnets each having a proximal end and a distal end, wherein each magnet comprises a plurality of magnetic segments and at least one magnetic segment towards the distal end comprises a high resistivity magnetic material.

HNF1β Is Essential for Nephron Segmentation during Nephrogenesis

PubMed Central

Naylor, Richard W.; Przepiorski, Aneta; Ren, Qun; Yu, Jing

2012-01-01

Nephrons comprise a blood filter and an epithelial tubule that is subdivided into proximal and distal segments, but what directs this patterning during kidney organogenesis is not well understood. Using zebrafish, we found that the HNF1β paralogues hnf1ba and hnf1bb, which encode homeodomain transcription factors, are essential for normal segmentation of nephrons. Embryos deficient in hnf1ba and hnf1bb did not express proximal and distal segment markers, yet still developed an epithelial tubule. Initiating hnf1ba/b expression required Pax2a and Pax8, but hnf1ba/b-deficient embryos did not exhibit the expected downregulation of pax2a and pax8 at later stages of development, suggesting complex regulatory loops involving these molecules. Embryos deficient in hnf1ba/b also did not express the irx3b transcription factor, which is responsible for differentiation of the first distal tubule segment. Reciprocally, embryos deficient in irx3b exhibited downregulation of hnf1ba/b transcripts in the distal early segment, suggesting a segment-specific regulatory circuit. Deficiency of hnf1ba/b also led to ectopic expansion of podocytes into the proximal tubule domain. Epistasis experiments showed that the formation of podocytes required wt1a, which encodes the Wilms’ tumor suppressor-1 transcription factor, and rbpj, which encodes a mediator of canonical Notch signaling, downstream or parallel to hnf1ba/b. Taken together, these results suggest that Hnf1β factors are essential for normal segmentation of nephrons during kidney organogenesis. PMID:23160512

HNF1β is essential for nephron segmentation during nephrogenesis.

PubMed

Naylor, Richard W; Przepiorski, Aneta; Ren, Qun; Yu, Jing; Davidson, Alan J

2013-01-01

Nephrons comprise a blood filter and an epithelial tubule that is subdivided into proximal and distal segments, but what directs this patterning during kidney organogenesis is not well understood. Using zebrafish, we found that the HNF1β paralogues hnf1ba and hnf1bb, which encode homeodomain transcription factors, are essential for normal segmentation of nephrons. Embryos deficient in hnf1ba and hnf1bb did not express proximal and distal segment markers, yet still developed an epithelial tubule. Initiating hnf1ba/b expression required Pax2a and Pax8, but hnf1ba/b-deficient embryos did not exhibit the expected downregulation of pax2a and pax8 at later stages of development, suggesting complex regulatory loops involving these molecules. Embryos deficient in hnf1ba/b also did not express the irx3b transcription factor, which is responsible for differentiation of the first distal tubule segment. Reciprocally, embryos deficient in irx3b exhibited downregulation of hnf1ba/b transcripts in the distal early segment, suggesting a segment-specific regulatory circuit. Deficiency of hnf1ba/b also led to ectopic expansion of podocytes into the proximal tubule domain. Epistasis experiments showed that the formation of podocytes required wt1a, which encodes the Wilms' tumor suppressor-1 transcription factor, and rbpj, which encodes a mediator of canonical Notch signaling, downstream or parallel to hnf1ba/b. Taken together, these results suggest that Hnf1β factors are essential for normal segmentation of nephrons during kidney organogenesis.

Proliferative and morphologic changes in rat colon following bypass surgery.

PubMed

Barkla, D H; Tutton, P J

1985-06-01

In this study the proliferative and morphologic changes that occur in the colon of normal and dimethylhydrazine-treated rats following surgical bypass of the middle third of the colon are reported. Proliferative changes were measured by estimating accumulated mitotic indexes following vinblastine treatment and morphologic changes were observed with the use of light microscopy and scanning electron microscopy. Data were collected on Days 0, 7, 14, 30, and 72 after surgery. The results show that surgical bypass produces contrasting effects in the segments proximal to and distal to the suture line. In the proximal segment there was morphologic evidence of hyperplasia, although proliferative activity was unchanged except for an increase at 7 days in normal rats. In the distal segment there was a long-lived increase in the mitotic index, although morphologic changes were not seen. The results for DMH-treated rats were similar to those in normal rats. Groups of isolated dysplastic epithelial cells were often seen in the submucosa adjacent to sutures up to 72 days after surgery. Increased lymphoid infiltration was seen in segments proximal to but not distal to the suture line. It is hypothesized that the different responses of the proximal and distal segments may be related to the different embryologic origins of those segments. It is also hypothesized that the seeding of the submucosa with epithelial cells during suturing may be a factor in tumor recurrence.

Occipital Artery Function during the Development of 2-Kidney, 1-Clip Hypertension in Rats

PubMed Central

Chelko, Stephen P.; Schmiedt, Chad W.; Lewis, Tristan H.; Robertson, Tom P.; Lewis, Stephen J.

2014-01-01

This study compared the contractile responses elicited by angiotensin II (AII), arginine vasopressin (AVP), and 5-hydroxytryptamine (5-HT) in isolated occipital arteries (OAs) from sham-operated (SHAM) and 2-kidney, 1-clip (2K-1C) hypertensive rats. OAs were isolated and bisected into proximal segments (closer to the common carotid artery) and distal segments (closer to the nodose ganglion) and mounted separately on myographs. On day 9, 2K-1C rats had higher mean arterial blood pressures, heart rates, and plasma renin concentrations than SHAM rats. The contractile responses to AII were markedly diminished in both proximal and distal segments of OAs from 2K-1C rats as compared to those from SHAM rats. The responses elicited by AVP were substantially greater in distal than in proximal segments of OAs from SHAM rats and that AVP elicited similar responses in OA segments from 2K-1C rats. The responses elicited by 5-HT were similar in proximal and distal segments from SHAM and 2K-1C rats. These results demonstrate that continued exposure to circulating AII and AVP in 2K-1C rats reduces the contractile efficacy of AII but not AVP or 5-HT. The diminished responsiveness to AII may alter the physiological status of OAs in vivo. PMID:25140254

Closed retrograde retrieval of the distal broken segment of femoral cannulated intramedullary nail using a ball-tipped guide wire.

PubMed

Metikala, Sreenivasulu; Mohammed, Riazuddin

2011-07-01

Extracting broken segments of intramedullay nails from long bones can be an operative challenge, particularly from the distal end. We report a case series where a simple and reproducible technique of extracting broken femoral cannulated nails using a ball-tipped guide wire is described. This closed technique involves no additional equipment or instruments. Eight patients who underwent the described method were included in the study. The technique involves using a standard plain guide wire passed through the cannulated distal broken nail segment after extraction of the proximal nail fragment. The plain guide wire is then advanced distally into the knee joint carefully under fluoroscopy imaging. Over this wire, a 5-millimeter (mm) cannulated large drill bit is used to create a track up to the distal broken nail segment. Through the small knee wound, a ball-tipped guide wire is passed, smooth end first, till the ball engages the end of the nail. The guide wire is then extracted along with the broken nail through the proximal wound. The method was successfully used in all eight patients for removal of broken cannulated intramedullary nail from the femoral canal without any complications. All patients underwent exchange nailing with successful bone union in six months. None of the patients had any problems at the knee joint at the final follow-up. We report a technique for successful extraction of the distal fragment of broken femoral intramedullary nails without additional surgical approaches.

Vasopressin-induced constriction of the isolated rat occipital artery is segment-dependent

PubMed Central

Chelko, Stephen P.; Schmiedt, Chad W.; Lewis, Tristan H.; Lewis, Stephen J.; Robertson, Tom P.

2014-01-01

Background Circulating factors delivered to the nodose ganglion (NG) by the occipital artery (OA) have shown to affect vagal afferent activity, and thus the contractile state of the OA may influence blood flow to the NG. Methods OA were isolated and bisected into proximal and distal segments, relative to the external carotid artery. Results Bisection, highlighted stark differences between maximal contractile responses and OA sensitivity. Specifically, maximum responses to vasopressin and the V1 receptor agonist, were significantly higher in distal than proximal segments. Distal segments were significantly more sensitive to 5-HT and the 5-HT2 receptor agonist than proximal segments. AT2, V2 and 5-HT1B/1D receptor agonists did not elicit vascular responses. Additionally, AT1 receptor agonists elicited mild, yet not significantly different maximal responses between segments. Conclusion The results of this study are consistent with contractile properties of rat OA being mediated via AT1, V1 and 5-HT2 receptors, and are dependent upon the OA segment. Furthermore, vasopressin-induced constriction of the OA, regardless of a bolus dose or a first and second concentration response curve retained this unique segmental difference and therefore we hypothesize this may be a pathophysiological response in the regulation of blood flow through the OA. PMID:24192548

Vasopressin-induced constriction of the isolated rat occipital artery is segment dependent.

PubMed

Chelko, Stephen P; Schmiedt, Chad W; Lewis, Tristan H; Lewis, Stephen J; Robertson, Tom P

2013-01-01

Circulating factors delivered to the nodose ganglion (NG) by the occipital artery (OA) have been shown to affect vagal afferent activity, and thus the contractile state of the OA may influence blood flow to the NG. OA were isolated and bisected into proximal and distal segments relative to the external carotid artery. Bisection highlighted stark differences between maximal contractile responses and OA sensitivity. Specifically, maximum responses to vasopressin and the V1 receptor agonist were significantly higher in distal than proximal segments. Distal segments were significantly more sensitive to 5-hydroxytryptamine (5-HT) and the 5-HT2 receptor agonist than proximal segments. Angiotensin II (AT)2, V2 and 5-HT(1B/1D) receptor agonists did not elicit vascular responses. Additionally, AT1 receptor agonists elicited mild, yet not significantly different maximal responses between segments. The results of this study are consistent with contractile properties of rat OA being mediated via AT1, V1 and 5-HT2 receptors and dependent upon the OA segment. Furthermore, vasopressin-induced constriction of the OA, regardless of a bolus dose or a first and second concentration-response curve, retained this unique segmental difference. We hypothesize that these segmental differences may be important in the regulation of blood flow through the OA in health and disease. © 2013 S. Karger AG, Basel.

Electron microscopic observations of human sperm whole-mounts after extraction for nuclear matrix and intermediate filaments (NM-IF).

PubMed

Markova, Maya Dyankova

2004-10-01

The extraction for nuclear matrix and intermediate filaments (NM-IF) is used to reveal, isolate and study these highly resistant structures in different cell types. We applied for the first time this chemical dissection to human spermatozoa and observed them as whole-mounts by unembedded electron microscopy. The general appearance of NM-IF extracted sperm cells was preserved, showing the intermediate filament-like properties of their cytoskeletal components. In most heads, a network was observed in subacrosomal position, consisting of hubs interconnected by filaments. It seemed to be overlaid on another, finer network. The neck retained its integrity, allowing observations of the three-dimensional structure of the segmented columns. More distally, axoneme and outer dense fibres were covered by submitochondrial cytoskeleton in the middle piece and fibrous sheath in the principal piece, with the annulus usually detached from the fibrous sheath. End piece microtubules were retained in most cells and showed a tendency of cohesion, remaining in a parallel bundle or forming flat sheets. In conclusion, our results provided additional structural details of human sperm cytoskeleton and demonstrated the advantages of combining different methodological approaches in ultrastructural research.

Impact of fecal immunochemical test-based screening programs on proximal and distal colorectal cancer surgery rates: A natural multiple-baseline experiment.

PubMed

Fedeli, Ugo; Zorzi, Manuel; Urso, Emanuele D L; Gennaro, Nicola; Dei Tos, Angelo P; Saugo, Mario

2015-11-15

Colorectal cancer (CRC) screening programs based on the fecal immunochemical test (FIT) were found to reduce overall CRC surgery rates, but to the authors' knowledge data by subsite are lacking. The objective of the current study was to assess the impact of FIT-based screening on proximal and distal CRC surgical resection rates. The Veneto region in Italy can be subdivided into 3 areas with staggered introduction of FIT-based screening programs: early (2002-2004), intermediate (2005-2007), and late (2008-2009) areas. Time series of proximal and distal CRC surgery were investigated in the 3 populations between 2001 and 2012 by Joinpoint regression analysis and segmented Poisson regression models. The impact of screening was similar in the study populations. Rates of distal CRC surgical resection were stable before screening, increased at the time of screening implementation (rate ratio [RR], 1.25; 95% confidence interval [95% CI], 1.14-1.37), and thereafter declined by 10% annually (RR, 0.90; 95% CI, 0.88-0.92). Rates of proximal CRC surgical resection increased by 4% annually before screening (RR, 1.04; 95% CI, 1.03-1.05) but, after a peak at the time of screening initiation, the trend was reversed. The percentage represented by proximal CRC surgery rose from 28% in 2001 to 41% in 2012. In this natural multiple-baseline experiment, consistent findings across each time series demonstrated that FIT-based screening programs have an impact both on proximal and distal CRC surgery rates. However, underlying preexisting epidemiological trends are leading to a rapidly increasing percentage of proximal CRC. © 2015 American Cancer Society.

What is the real impairment on esophageal motility in patients with gastroesophageal reflux disease?

PubMed

Falcão, Angela; Nasi, Ary; Brandão, Jeovana; Sallum, Rubens; Cecconello, Ivan

2013-04-01

Impairment of esophageal motility is a common finding in patients with gastroesophageal reflux disease (GERD) as reduced lower esophageal sphincter (LES) basal pressure. A very low LES pressure might facilitate the occurrence of more gastroesophageal reflux whereas abnormal esophageal peristalsis may contribute to impaired esophageal clearance after reflux. Evaluate the esophageal motor function of the lower esophageal sphincter and esophageal body in the various forms of gastroesophageal reflux disease. The manometrics records of 268 patients, who had evaluation of the esophageal motility as part of the diagnostic gastroesophageal reflux disease were split into four groups, as follows: 33 patients who had no esophagitis; 92 patients who had erosive esophagitis; 101 patients who had short Barrett's esophagus and 42 patients who had long Barrett's esophagus. The group who had long Barrett's esophagus showed smaller mean LES pressure and higher percentage of marked LES hypotonia; in the distal segment of the esophageal body the this group showed higher percentage of marked hypocontractility of the distal segment (<30 mm Hg); this same group showed higher percentage of esophageal motility disorders. The most intense esophageal motility disorders and lower pressure of lower esophageal sphincter were noted in the group with long Barrett's esophagus. Those with reflux esophagitis and short Barrett's esophagus had esophageal motility impairment, intermediate among patients with esophagitis and long Barrett's esophagus. Patients with typical symptoms of gastroesophageal reflux but without esophagitis by endoscopy study showed no impairment of esophageal motility.

Neuron Morphology Influences Axon Initial Segment Plasticity.

PubMed

Gulledge, Allan T; Bravo, Jaime J

2016-01-01

In most vertebrate neurons, action potentials are initiated in the axon initial segment (AIS), a specialized region of the axon containing a high density of voltage-gated sodium and potassium channels. It has recently been proposed that neurons use plasticity of AIS length and/or location to regulate their intrinsic excitability. Here we quantify the impact of neuron morphology on AIS plasticity using computational models of simplified and realistic somatodendritic morphologies. In small neurons (e.g., dentate granule neurons), excitability was highest when the AIS was of intermediate length and located adjacent to the soma. Conversely, neurons having larger dendritic trees (e.g., pyramidal neurons) were most excitable when the AIS was longer and/or located away from the soma. For any given somatodendritic morphology, increasing dendritic membrane capacitance and/or conductance favored a longer and more distally located AIS. Overall, changes to AIS length, with corresponding changes in total sodium conductance, were far more effective in regulating neuron excitability than were changes in AIS location, while dendritic capacitance had a larger impact on AIS performance than did dendritic conductance. The somatodendritic influence on AIS performance reflects modest soma-to-AIS voltage attenuation combined with neuron size-dependent changes in AIS input resistance, effective membrane time constant, and isolation from somatodendritic capacitance. We conclude that the impact of AIS plasticity on neuron excitability will depend largely on somatodendritic morphology, and that, in some neurons, a shorter or more distally located AIS may promote, rather than limit, action potential generation.

Neuron Morphology Influences Axon Initial Segment Plasticity123

PubMed Central

2016-01-01

In most vertebrate neurons, action potentials are initiated in the axon initial segment (AIS), a specialized region of the axon containing a high density of voltage-gated sodium and potassium channels. It has recently been proposed that neurons use plasticity of AIS length and/or location to regulate their intrinsic excitability. Here we quantify the impact of neuron morphology on AIS plasticity using computational models of simplified and realistic somatodendritic morphologies. In small neurons (e.g., dentate granule neurons), excitability was highest when the AIS was of intermediate length and located adjacent to the soma. Conversely, neurons having larger dendritic trees (e.g., pyramidal neurons) were most excitable when the AIS was longer and/or located away from the soma. For any given somatodendritic morphology, increasing dendritic membrane capacitance and/or conductance favored a longer and more distally located AIS. Overall, changes to AIS length, with corresponding changes in total sodium conductance, were far more effective in regulating neuron excitability than were changes in AIS location, while dendritic capacitance had a larger impact on AIS performance than did dendritic conductance. The somatodendritic influence on AIS performance reflects modest soma-to-AIS voltage attenuation combined with neuron size-dependent changes in AIS input resistance, effective membrane time constant, and isolation from somatodendritic capacitance. We conclude that the impact of AIS plasticity on neuron excitability will depend largely on somatodendritic morphology, and that, in some neurons, a shorter or more distally located AIS may promote, rather than limit, action potential generation. PMID:27022619

Comparative analysis of the pressure profilometry of vesicocutaneous continent catheterizable conduits between patients with and without rectus abdominis neosphincter (Yachia principle).

PubMed

Rondon, Atila; Leslie, Bruno; Arcuri, Leonardo Javier; Ortiz, Valdemar; Macedo, Antonio

2015-09-01

To assess whether crossing rectus abdominis muscle strips, as proposed by Yachia, would change urinary catheterizable conduit's pressure profilometry, in static and dynamic conditions. Non-randomized selection of 20 continent patients that underwent Macedo's ileum-based reservoir, 10 including Yachia's technique (Study Group) and 10 without this mechanism of continence (Control Group). Demographics and cystometric data were assessed. Conduit's pressure profilometry was obtained by infusing saline through a multichannel catheter, at rest and during Valsalva maneuver. We assessed the pressure: (a) in the bladder; (b) in conduit's proximal segment; and (c) in conduit's distal segment, which is presumably the abdominal wall and crossed muscle strips site. Mean age at surgery was 6.1 years in the Control Group and 7.7 years in the Study Group. There was no statistically significant difference between groups regarding maximum cystometric bladder capacity and leakage point pressure. At rest, the pressure profilometry showed similar results between groups in all segments analyzed. During Valsalva maneuver, pressure profilometry showed similar results between groups in bladder and conduit's proximal segment pressure. In this condition, conduit's distal segment pressure in the Study Group (Mean = 72.9 and Peak = 128.7 cmH2 O) was significantly greater (P < 0.05) than conduit's distal segment pressure in the Control Group (Mean = 48.3 and Peak = 65.1 cmH2 O). Crossing muscle strips over the conduit significantly increases the pressure in its distal segment during contraction of the rectus abdominis muscle, which can be important in moments of sudden increase in abdominal pressure in order to keep continence. © 2014 Wiley Periodicals, Inc.

Brominated flame retardant (BFRs) and Dechlorane Plus (DP) in paired human serum and segmented hair.

PubMed

Qiao, Lin; Zheng, Xiao-Bo; Yan, Xiao; Wang, Mei-Huang; Zheng, Jing; Chen, She-Jun; Yang, Zhong-Yi; Mai, Bi-Xian

2018-01-01

Brominated flame retardants (BFRs) and Dechlorane Plus (DP) were measured in both human hair and paired serum samples from a cohort of university students in South China. Segmental analysis was conducted to explore gender difference and the relationships between the hair and serum. The concentrations of total PBDEs in the hair and serum samples were in a range of 0.28-34.1ng/g dry weight (dw) and 0.16-156ng/g lipid weight (lw), respectively. Concentrations of ∑DPs (sum of the syn-DP and anti-DP isomers) in all hair samples ranged from nd-5.45ng/g dry weight. Concentrations of most PBDEs and decabromodiphenylethane (DBDPE) in distal segments (5-10cm from the scalp) were higher than those in the proximal segments (0-5cm from the scalp) (t-test, p < 0.05), which could be due to the longer exposure time of distal segments. The proximal segments exhibited a unique congener profile, more close to that in the serum rather than the distal segments of hair. An obvious gender difference was found in the levels of ∑PBDEs using integrated hair samples, while the difference disappeared when considering alone the proximal segments of hair (0-5cm from scalp) for both genders. This paper provides supplement to the current knowledge on sources of BFRs and DPs in hair and declares the importance of segmental analysis. Copyright © 2017 Elsevier Inc. All rights reserved.

Proliferative and morphologic changes in rat colon following bypass surgery.

PubMed Central

Barkla, D. H.; Tutton, P. J.

1985-01-01

In this study the proliferative and morphologic changes that occur in the colon of normal and dimethylhydrazine-treated rats following surgical bypass of the middle third of the colon are reported. Proliferative changes were measured by estimating accumulated mitotic indexes following vinblastine treatment and morphologic changes were observed with the use of light microscopy and scanning electron microscopy. Data were collected on Days 0, 7, 14, 30, and 72 after surgery. The results show that surgical bypass produces contrasting effects in the segments proximal to and distal to the suture line. In the proximal segment there was morphologic evidence of hyperplasia, although proliferative activity was unchanged except for an increase at 7 days in normal rats. In the distal segment there was a long-lived increase in the mitotic index, although morphologic changes were not seen. The results for DMH-treated rats were similar to those in normal rats. Groups of isolated dysplastic epithelial cells were often seen in the submucosa adjacent to sutures up to 72 days after surgery. Increased lymphoid infiltration was seen in segments proximal to but not distal to the suture line. It is hypothesized that the different responses of the proximal and distal segments may be related to the different embryologic origins of those segments. It is also hypothesized that the seeding of the submucosa with epithelial cells during suturing may be a factor in tumor recurrence. Images Figure 19 Figure 20 Figure 21 Figure 22 Figure 7 Figure 8 Figure 9 Figure 10 Figure 11 Figure 12 Figure 13 Figure 14 Figure 15 Figure 16 Figure 17 Figure 18 PMID:4014432

Immunohistologic analysis of spontaneous recurrent laryngeal nerve reinnervation in a rat model.

PubMed

Rosko, Andrew J; Kupfer, Robbi A; Oh, Sang S; Haring, Catherine T; Feldman, Eva L; Hogikyan, Norman D

2018-03-01

After recurrent laryngeal nerve injury (RLN), spontaneous reinnervation of the larynx occurs with input from multiple sources. The purpose of this study was to determine the timing and efficiency of reinnervation across a resected RLN segment in a rat model of RLN injury. Animal study. Twelve male 60-day-old Sprague Dawley rats underwent resection of a 5-mm segment of the right RLN. Rats were sacrificed at 1, 2, 4, and 12 weeks after nerve injury to harvest the larynx and trachea for immunohistologic analysis. The distal RLN segment was stained with neurofilament, and axons were counted and compared to the nonoperated side. Thyroarytenoid (TA) muscles were stained with alpha-bungarotoxin, synaptophysin, and neurofilament to identify intact neuromuscular junctions (NMJ). The number of intact NMJs from the denervated side was compared to the nonoperated side. Nerve fibers regenerated across the resected RLN gap into the distal recurrent laryngeal nerve to innervate the TA muscle. The number of nerve fibers in the distal nerve segment increased over time and reached the normal number by 12 weeks postdenervation. Axons formed intact neuromuscular junctions in the TA, with 48.8% ± 16.7% of the normal number of intact NMJs at 4 weeks and 88.3% ± 30.1% of the normal number by 12 weeks. Following resection of an RLN segment in a rat model, nerve fibers spontaneously regenerate through the distal segment of the transected nerve and form intact NMJs in order to reinnervate the TA muscle. NA. Laryngoscope, 128:E117-E122, 2018. © 2017 The American Laryngological, Rhinological and Otological Society, Inc.

Utility of Diffusion-Weighted MRI to Detect Changes in Liver Diffusion in Benign and Malignant Distal Bile Duct Obstruction: The Influence of Choice of b-Values.

PubMed

Karan, Belgin; Erbay, Gurcan; Koc, Zafer; Pourbagher, Aysin; Yildirim, Sedat; Agildere, Ahmet Muhtesem

2016-11-01

The study sought to evaluate the potential of diffusion-weighted magnetic resonance imaging to detect changes in liver diffusion in benign and malignant distal bile duct obstruction and to investigate the effect of the choice of b-values on apparent diffusion coefficient (ADC). Diffusion-weighted imaging was acquired with b-values of 200, 600, 800, and 1000 s/mm 2 . ADC values were obtained in 4 segments of the liver. The mean ADC values of 16 patients with malignant distal bile duct obstruction, 14 patients with benign distal bile duct obstruction, and a control group of 16 healthy patients were compared. Mean ADC values for 4 liver segments were lower in the malignant obstruction group than in the benign obstruction and control groups using b = 200 s/mm 2 (P < .05). Mean ADC values of the left lobe medial and lateral segments were lower in the malignant obstruction group than in the benign obstructive and control groups using b = 600 s/mm 2 (P < .05). Mean ADC values of the right lobe posterior segment were lower in the malignant and benign obstruction groups than in the control group using b = 1000 s/mm 2 (P < .05). Using b = 800 s/mm 2 , ADC values of all 4 liver segments in each group were not significantly different (P > .05). There were no correlations between the ADC values of liver segments and liver function tests. Measurement of ADC shows good potential for detecting changes in liver diffusion in patients with distal bile duct obstruction. Calculated ADC values were affected by the choice of b-values. Copyright © 2016 Canadian Association of Radiologists. Published by Elsevier Inc. All rights reserved.

Femoral curvature variability in modern humans using three-dimensional quadric surface fitting.

PubMed

Chapman, Tara; Sholukha, Victor; Semal, Patrick; Louryan, Stéphane; Rooze, Marcel; Van Sint Jan, Serge

2015-12-01

This study analysed femoral curvature in a population from Belgium in conjunction with other morphological characteristics by the use of three-dimensional (3D) quadric surfaces (QS) modelled from the bone surface. 3D models were created from computed tomography data of 75 femoral modern human bones. Anatomical landmarks (ALs) were palpated in specific bony areas of the femur (shaft, condyles, neck and head). QS were then created from the surface vertices which enclose these ALs. The diaphyseal shaft was divided into five QS shapes to analyse curvature in different parts of the shaft. Femoral bending differs in different parts of the diaphyseal shaft. The greatest degree of curvature was found in the distal shaft (mean 4.5° range 0.2°-10°) followed by the proximal (mean 4.4° range 1.5°-10.2°), proximal intermediate (mean 3.7° range 0.9°-7.9°) and distal intermediate (mean 1.8° range 0.2°-5.6°) shaft sections. The proximal and distal angles were significantly more bowed than the intermediate proximal and the intermediate distal angle. There was no significant difference between the proximal and distal angle. No significant correlations were found between morphological characteristics and femoral curvature. An extremely large variability of femoral curvature with several bones displaying very high or low degrees of femoral curvature was also found. 3D QS fitting enables the creation of accurate models which can discriminate between different patterns in similar curvatures and demonstrates there is a clear difference between curvature in different parts of the shaft.

Plaque shift and distal embolism in patients with acute myocardial infarction: a volumetric intravascular ultrasound analysis from the HORIZONS-AMI trial.

PubMed

Wu, Xiaofan; Maehara, Akiko; He, Yong; Xu, Kai; Oviedo, Carlos; Witzenbichler, Bernhard; Lansky, Alexandra J; Dressler, Ovidiu; Parise, Helen; Stone, Gregg W; Mintz, Gary S

2013-08-01

Vessel expansion and axial plaque redistribution or distal plaque embolization contribute to the increase in lumen dimensions after stent implantation. Preintervention and postintervention grayscale volumetric intravascular ultrasound was used to study 43 de novo native coronary lesions treated with TAXUS or Express bare metal stents in the HORIZONS-AMI Trial. There was a decrease in lesion segment plaque + media (P + M) volume (-19.5 ± 22.2 mm(3) ) that was associated with a decrease in overall analysis segment (lesion plus 5 mm long proximal and distal reference segments) P + M volume (-17.5 ± 21.0 mm(3) ) that was greater than the shift of plaque from the lesion to the proximal and distal reference segments (1.9 ± 4.5 mm(3) , P < 0.0001). Overall analysis segment P + M volume decreased more in the angiographic thrombus (+) versus the thrombus (-) group (27.4 ± 23.4 vs. -8.9 ± 14.3 mm(3) , P = 0.003), whereas plaque shift to the reference segments showed no significant difference between the two groups (1.5 ± 5.2 vs. 2.3 ± 3.9 mm(3) , P = 0.590). Compared with the angiographic thrombus (-) group, patients in the thrombus (+) group more often developed no reflow (25% vs. 0%, P = 0.012) and had a higher preintervention CK-MB (P = 0.011), postintervention CK-MB (P < 0.001), and periprocedural (post-PCI minus pre-PCI) elevation of CK-MB (P = 0.001). In acute myocardial infarction lesions, there was a marked poststenting reduction in overall plaque volume that was significantly greater in patients with angiographic thrombus than without thrombus and may have explained a greater periprocedural rise in CK-MB. © 2013 Wiley Periodicals, Inc.

Modeling of the interaction between grip force and vibration transmissibility of a finger.

PubMed

Wu, John Z; Welcome, Daniel E; McDowell, Thomas W; Xu, Xueyan S; Dong, Ren G

2017-07-01

It is known that the vibration characteristics of the fingers and hand and the level of grip action interacts when operating a power tool. In the current study, we developed a hybrid finger model to simulate the vibrations of the hand-finger system when gripping a vibrating handle covered with soft materials. The hybrid finger model combines the characteristics of conventional finite element (FE) models, multi-body musculoskeletal models, and lumped mass models. The distal, middle, and proximal finger segments were constructed using FE models, the finger segments were connected via three flexible joint linkages (i.e., distal interphalangeal joint (DIP), proximal interphalangeal joint (PIP), and metacarpophalangeal (MCP) joint), and the MCP joint was connected to the ground and handle via lumped parameter elements. The effects of the active muscle forces were accounted for via the joint moments. The bone, nail, and hard connective tissues were assumed to be linearly elastic whereas the soft tissues, which include the skin and subcutaneous tissues, were considered as hyperelastic and viscoelastic. The general trends of the model predictions agree well with the previous experimental measurements in that the resonant frequency increased from proximal to the middle and to the distal finger segments for the same grip force, that the resonant frequency tends to increase with increasing grip force for the same finger segment, especially for the distal segment, and that the magnitude of vibration transmissibility tends to increase with increasing grip force, especially for the proximal segment. The advantage of the proposed model over the traditional vibration models is that it can predict the local vibration behavior of the finger to a tissue level, while taking into account the effects of the active musculoskeletal force, the effects of the contact conditions on vibrations, the global vibration characteristics. Published by Elsevier Ltd.

Effect of acid swallowing on esophageal contraction in patients with heartburn related to hypersensitivity.

PubMed

Lee, Hyuk; Lee, Sang Kil; Park, Jun Chul; Shin, Sung Kwan; Lee, Yong Chan

2013-01-01

There are heterogeneous subgroups among those with heartburn, and data on these individuals are relatively scant. We aimed to evaluate the effect of acid challenge on the segmental contractions of esophageal smooth muscle in endoscopy-negative patients with normal esophageal acid exposure. High-resolution esophageal manometry (HRM) was performed on 30 endoscopy-negative patients with heartburn accompanied by normal esophageal acid exposure using 10 water swallows followed by 10 acidic pomegranate juice swallows. Patients were classified into functional heartburn (FH) and hypersensitive esophagus (HE) groups based on the results of 24-hr impedance pH testing. HRM topographic plots were analyzed and maximal wave amplitude and pressure volumes were measured for proximal and distal smooth muscle segments. The pressure volume of the distal smooth muscle segment in the HE group measured during acidic swallows was higher than during water swallows (2224.1 ± 68.2 mmHg/cm per s versus 2105.6 ± 66.4 mmHg/cm per s, P = 0.027). A prominent shift in the pressure volume to the distal smooth muscle segment was observed in the HE group compared with the FH group (segmental ratio: 2.72 ± 0.08 versus 2.39 ± 0.07, P = 0.005). Manometric measurements during acidic swallows revealed that this shift was augmented in the HE group. The optimal ratio of pomegranate juice swallowing for discrimination of FH from HE was 2.82, with a sensitivity of 88.9% and a specificity of 100%. Hypercontractile response of distal smooth muscle segment to acid swallowing was more prominent in the HE group than the FH group. © 2012 Journal of Gastroenterology and Hepatology Foundation and Wiley Publishing Asia Pty Ltd.

Analysis of human hair to assess exposure to organophosphate flame retardants: Influence of hair segments and gender differences.

PubMed

Qiao, Lin; Zheng, Xiao-Bo; Zheng, Jing; Lei, Wei-Xiang; Li, Hong-Fang; Wang, Mei-Huan; He, Chun-Tao; Chen, She-Jun; Yuan, Jian-Gang; Luo, Xiao-Jun; Yu, Yun-Jiang; Yang, Zhong-Yi; Mai, Bi-Xian

2016-07-01

Hair is a promising, non-invasive, human biomonitoring matrix that can provide insight into retrospective and integral exposure to organic pollutants. In the present study, we measured the concentrations of organophosphate flame retardants (PFRs) in hair and serum samples from university students in Guangzhou, China, and compared the PFR concentrations in the female hair segments using paired distal (5~10cm from the root) and proximal (0~5cm from the root) samples. PFRs were not detected in the serum samples. All PFRs except tricresyl phosphate (TMPP) and tri-n-propyl phosphate (TPP) were detected in more than half of all hair samples. The concentrations of total PFRs varied from 10.1 to 604ng/g, with a median of 148ng/g. Tris(chloroisopropyl) phosphate (TCIPP) and tri(2-ethylexyl) phosphate (TEHP) were the predominant PFRs in hair. The concentrations of most PFRs in the distal segments were 1.5~8.6 times higher than those in the proximal segments of the hair (t-test, p<0.05), which may be due to the longer exposure time of the distal segments to external sources. The values of log (PFR concentrations-distal/PFR concentrations-proximal) were positively and significantly correlated with log KOA of PFRs (p<0.05, r=0.68), indicating that PFRs with a higher log KOA tend to accumulate in hair at a higher rate than PFRs with a lower log KOA. Using combined segments of female hair, significantly higher PFR concentrations were observed in female hair than in male hair. In contrast, female hair exhibited significantly lower PFR concentrations than male hair when using the same hair position for both genders (0-5cm from the scalp). The controversial results regarding gender differences in PFRs in hair highlight the importance of segmental analysis when using hair as an indicator of human exposure to PFRs. Copyright © 2016 Elsevier Inc. All rights reserved.

The influence of distal-end heat treatment on deflection of nickel-titanium archwire.

PubMed

Silva, Marcelo Faria da; Pinzan-Vercelino, Célia Regina Maia; Gurgel, Júlio de Araújo

2016-01-01

The aim of this in vitro study was to evaluate the deflection-force behavior of nickel-titanium (NiTi) orthodontic wires adjacent to the portion submitted to heat treatment. A total of 106 segments of NiTi wires (0.019 x 0.025-in) and heat-activated NiTi wires (0.016 x 0.022-in) from four commercial brands were tested. The segments were obtained from 80 archwires. For the experimental group, the distal portion of each segmented archwire was subjected to heat treatment (n = 40), while the other distal portion of the same archwire was used as a heating-free control group (n = 40). Deflection tests were performed in a temperature-controlled universal testing machine. Unpaired Student's t-tests were applied to determine if there were differences between the experimental and control groups for each commercial brand and size of wire. Statistical significance was set at p < 0.05. There were no statistically significant differences between the tested groups with the same size and brand of wire. Heat treatment applied to the distal ends of rectangular NiTi archwires does not permanently change the elastic properties of the adjacent portions.

The influence of distal-end heat treatment on deflection of nickel-titanium archwire

PubMed Central

da Silva, Marcelo Faria; Pinzan-Vercelino, Célia Regina Maia; Gurgel, Júlio de Araújo

2016-01-01

Objective: The aim of this in vitro study was to evaluate the deflection-force behavior of nickel-titanium (NiTi) orthodontic wires adjacent to the portion submitted to heat treatment. Material and Methods: A total of 106 segments of NiTi wires (0.019 x 0.025-in) and heat-activated NiTi wires (0.016 x 0.022-in) from four commercial brands were tested. The segments were obtained from 80 archwires. For the experimental group, the distal portion of each segmented archwire was subjected to heat treatment (n = 40), while the other distal portion of the same archwire was used as a heating-free control group (n = 40). Deflection tests were performed in a temperature-controlled universal testing machine. Unpaired Student's t-tests were applied to determine if there were differences between the experimental and control groups for each commercial brand and size of wire. Statistical significance was set at p < 0.05. Results: There were no statistically significant differences between the tested groups with the same size and brand of wire. Conclusions: Heat treatment applied to the distal ends of rectangular NiTi archwires does not permanently change the elastic properties of the adjacent portions. PMID:27007766

Mucosal integrity and sensitivity to acid in the proximal esophagus in patients with gastroesophageal reflux disease.

PubMed

van Hoeij, Froukje B; Weijenborg, Pim W; van den Bergh Weerman, Marius A; van den Wijngaard, René M J G J; Verheij, J; Smout, André J P M; Bredenoord, Albert J

2016-07-01

Acid reflux episodes that extend to the proximal esophagus are more likely to be perceived. This suggests that the proximal esophagus is more sensitive to acid than the distal esophagus, which could be caused by impaired mucosal integrity in the proximal esophagus. Our aim was to explore sensitivity to acid and mucosal integrity in different segments of the esophagus. We used a prospective observational study, including 12 patients with gastroesophageal reflux disease (GERD). After stopping acid secretion-inhibiting medication, two procedures were performed: an acid perfusion test and an upper endoscopy with electrical tissue impedance spectroscopy and esophageal biopsies. Proximal and distal sensitivity to acid and tissue impedance were measured in vivo, and mucosal permeability and epithelial intercellular spaces at different esophageal levels were measured in vitro. Mean lag time to heartburn perception was much shorter after proximal acid perfusion (0.8 min) than after distal acid perfusion (3.9 min) (P = 0.02). Median in vivo tissue impedance was significantly lower in the distal esophagus (4,563 Ω·m) compared with the proximal esophagus (8,170 Ω·m) (P = 0.002). Transepithelial permeability, as measured by the median fluorescein flux was significantly higher in the distal (2,051 nmol·cm(-2)·h(-1)) than in the proximal segment (368 nmol·cm(-2)·h(-1)) (P = 0.033). Intercellular space ratio and maximum heartburn intensity were not significantly different between the proximal and distal esophagus. In GERD patients off acid secretion-inhibiting medication, acid exposure in the proximal segment of the esophagus provokes symptoms earlier than acid exposure in the distal esophagus, whereas mucosal integrity is impaired more in the distal esophagus. These findings indicate that the enhanced sensitivity to proximal reflux episodes is not explained by increased mucosal permeability. Copyright © 2016 the American Physiological Society.

Surgical repair of sciatic nerve traumatic rupture: technical considerations and approaches.

PubMed

Abou-Al-Shaar, Hussam; Yoon, Nam; Mahan, Mark A

2018-01-01

Traumatic proximal sciatic nerve rupture poses surgical repair dilemmas. Disruption often causes a large nerve gap after proximal neuroma and distal scar removal. Also, autologous graft material to bridge the segmental defect may be insufficient, given the sciatic nerve diameter. The authors utilized knee flexion to allow single neurorrhaphy repair of a large sciatic nerve defect, bringing healthy proximal stump to healthy distal segment. To avoid aberrant regeneration, the authors split the sciatic nerve into common peroneal and tibial divisions. After 3 months, the patient can fully extend the knee and has evidence of distal regeneration and nerve continuity without substantial injury. The video can be found here: https://youtu.be/lsezRT5I8MU .

Sodium Channel Nav1.8 Underlies TTX-Resistant Axonal Action Potential Conduction in Somatosensory C-Fibers of Distal Cutaneous Nerves.

PubMed

Klein, Amanda H; Vyshnevska, Alina; Hartke, Timothy V; De Col, Roberto; Mankowski, Joseph L; Turnquist, Brian; Bosmans, Frank; Reeh, Peter W; Schmelz, Martin; Carr, Richard W; Ringkamp, Matthias

2017-05-17

Voltage-gated sodium (Na V ) channels are responsible for the initiation and conduction of action potentials within primary afferents. The nine Na V channel isoforms recognized in mammals are often functionally divided into tetrodotoxin (TTX)-sensitive (TTX-s) channels (Na V 1.1-Na V 1.4, Na V 1.6-Na V 1.7) that are blocked by nanomolar concentrations and TTX-resistant (TTX-r) channels (Na V 1.8 and Na V 1.9) inhibited by millimolar concentrations, with Na V 1.5 having an intermediate toxin sensitivity. For small-diameter primary afferent neurons, it is unclear to what extent different Na V channel isoforms are distributed along the peripheral and central branches of their bifurcated axons. To determine the relative contribution of TTX-s and TTX-r channels to action potential conduction in different axonal compartments, we investigated the effects of TTX on C-fiber-mediated compound action potentials (C-CAPs) of proximal and distal peripheral nerve segments and dorsal roots from mice and pigtail monkeys ( Macaca nemestrina ). In the dorsal roots and proximal peripheral nerves of mice and nonhuman primates, TTX reduced the C-CAP amplitude to 16% of the baseline. In contrast, >30% of the C-CAP was resistant to TTX in distal peripheral branches of monkeys and WT and Na V 1.9 -/- mice. In nerves from Na V 1.8 -/- mice, TTX-r C-CAPs could not be detected. These data indicate that Na V 1.8 is the primary isoform underlying TTX-r conduction in distal axons of somatosensory C-fibers. Furthermore, there is a differential spatial distribution of Na V 1.8 within C-fiber axons, being functionally more prominent in the most distal axons and terminal regions. The enrichment of Na V 1.8 in distal axons may provide a useful target in the treatment of pain of peripheral origin. SIGNIFICANCE STATEMENT It is unclear whether individual sodium channel isoforms exert differential roles in action potential conduction along the axonal membrane of nociceptive, unmyelinated peripheral nerve fibers, but clarifying the role of sodium channel subtypes in different axonal segments may be useful for the development of novel analgesic strategies. Here, we provide evidence from mice and nonhuman primates that a substantial portion of the C-fiber compound action potential in distal peripheral nerves, but not proximal nerves or dorsal roots, is resistant to tetrodotoxin and that, in mice, this effect is mediated solely by voltage-gated sodium channel 1.8 (Na V 1.8). The functional prominence of Na V 1.8 within the axonal compartment immediately proximal to its termination may affect strategies targeting pain of peripheral origin. Copyright © 2017 the authors 0270-6474/17/375205-11$15.00/0.

A comparative analysis of the dependences of the hemodynamic parameters on changes in ROI's position in perfusion CT scans

NASA Astrophysics Data System (ADS)

Choi, Yong-Seok; Cho, Jae-Hwan; Namgung, Jang-Sun; Kim, Hyo-Jin; Yoon, Dae-Young; Lee, Han-Joo

2013-05-01

This study performed a comparative analysis of cerebral blood volume (CBV), cerebral blood flow (CBF), mean transit time (MTT), and mean time-to-peak (TTP) obtained by changing the region of interest's (ROI) anatomical positions, during CT brain perfusion. We acquired axial source images of perfusion CT from 20 patients undergoing CT perfusion exams due to brain trauma. Subsequently, the CBV, CBF, MTT, and TTP values were calculated through data-processing of the perfusion CT images. The color scales for the CBV, CBF, MTT, and TTP maps were obtained using the image data. Anterior cerebral artery (ACA) was taken as the standard ROI for the calculations of the perfusion values. Differences in the hemodynamic average values were compared in a quantitative analysis by placing ROI and the dividing axial images into proximal, middle, and distal segments anatomically. By performing the qualitative analysis using a blind test, we observed changes in the sensory characteristics by using the color scales of the CBV, CBF, and MTT maps in the proximal, middle, and distal segments. According to the qualitative analysis, no differences were found in CBV, CBF, MTT, and TTP values of the proximal, middle, and distal segments and no changes were detected in the color scales of the the CBV, CBF, MTT, and TTP maps in the proximal, middle, and distal segments. We anticipate that the results of the study will useful in assessing brain trauma patients using by perfusion imaging.

Automatic partitioning of head CTA for enabling segmentation

NASA Astrophysics Data System (ADS)

Suryanarayanan, Srikanth; Mullick, Rakesh; Mallya, Yogish; Kamath, Vidya; Nagaraj, Nithin

2004-05-01

Radiologists perform a CT Angiography procedure to examine vascular structures and associated pathologies such as aneurysms. Volume rendering is used to exploit volumetric capabilities of CT that provides complete interactive 3-D visualization. However, bone forms an occluding structure and must be segmented out. The anatomical complexity of the head creates a major challenge in the segmentation of bone and vessel. An analysis of the head volume reveals varying spatial relationships between vessel and bone that can be separated into three sub-volumes: "proximal", "middle", and "distal". The "proximal" and "distal" sub-volumes contain good spatial separation between bone and vessel (carotid referenced here). Bone and vessel appear contiguous in the "middle" partition that remains the most challenging region for segmentation. The partition algorithm is used to automatically identify these partition locations so that different segmentation methods can be developed for each sub-volume. The partition locations are computed using bone, image entropy, and sinus profiles along with a rule-based method. The algorithm is validated on 21 cases (varying volume sizes, resolution, clinical sites, pathologies) using ground truth identified visually. The algorithm is also computationally efficient, processing a 500+ slice volume in 6 seconds (an impressive 0.01 seconds / slice) that makes it an attractive algorithm for pre-processing large volumes. The partition algorithm is integrated into the segmentation workflow. Fast and simple algorithms are implemented for processing the "proximal" and "distal" partitions. Complex methods are restricted to only the "middle" partition. The partitionenabled segmentation has been successfully tested and results are shown from multiple cases.

Throwing Pattern: Changes in Timing of Joint Lag According to Age between and within Skill Level

ERIC Educational Resources Information Center

Southard, Dan

2009-01-01

Accomplished throwers conserve angular momentum when distal joints of the throwing arm reach peak velocity at a later time than their proximal neighbors. The result is an increase in velocity of the most distal segment--the hand. Past research indicates that skill level varies by the number of joints experiencing distal timing lag (time to peak…

Comparative evaluation of molar distalization therapy with erupted second molar: Segmented versus Quad Pendulum appliance.

PubMed

Caprioglio, Alberto; Cozzani, Mauro; Fontana, Mattia

2014-01-01

There are controversial opinions about the effect of erupted second molars on distalization of the first molars. Most of the distalizing devices are anchored on the first molars, without including second molars; so, differences between sequentially distalize maxillary molars (second molar followed by the first molar) or distalize second and first molars together are not clear. The aim of the study was to compare sequential versus simultaneous molar distalization therapy with erupted second molar using two different modified Pendulum appliances followed by fixed appliances. The treatment sample consisted of 35 class II malocclusion subjects, divided in two groups: group 1 consisted of 24 patients (13 males and 11 females) with a mean pre-treatment age of 12.9 years, treated with the Segmented Pendulum (SP) and fixed appliances; group 2 consisted of 11 patients (6 males and 5 females) with a mean pre-treatment age of 13.2 years, treated with the Quad Pendulum (QP) and fixed appliances. Lateral cephalograms were obtained before treatment (T1), at the end of distalization (T2), and at the end of orthodontic fixed appliance therapy (T3). A Student t test was used to identify significant between-group differences between T1 to T2, T2 to T3, and T1 to T3. QP and SP were equally effective in distalizing maxillary molars (3.5 and 4 mm, respectively) between T1 and T2; however, the maxillary first molar showed less distal tipping (4.6° vs. 9.6°) and more extrusion (1.1 vs. 0.2 mm) in the QP group than in the SP group, as well as the vertical facial dimension, which increased more in the QP group (1.2°) than in the SP group (0.7°). At T3, the QP group maintained greater increase in lower anterior facial height and molar extrusion and decrease in overbite than the SP group. Quad Pendulum seems to have greater increase in vertical dimension and molar extrusion than the Segmented Pendulum.

Morphology of the kidney of adult bowfin, Amia calva, with emphasis on "renal chloride cells" in the tubule.

PubMed

Youson, J H; Butler, D G

1988-05-01

The nephron of adult bowfin, Amia calva, was described using light and electron microscopic techniques. The kidney of the bowfin possesses an abundant supply of renal corpuscles with each consisting of a glomerulus and a Bowman's capsule of visceral (podocyte) and parietal layers. No juxtaglomerular apparatus is present. The epithelium of the tubule is continuous with the parietal epithelium and is divisible in descending order into neck, first proximal, second proximal, first distal, second distal, and collecting segments. The tubules drain into a complex system of collecting ducts that ultimately unite with the main excretory duct, the archinephric duct. Mucous cells are the dominant cell throughout the entire ductular system. Nephrostomes are dispersed along the kidney capsule. The neck segment has a ciliated epithelium, and while both proximal segments possess a prominent brush border, the fine structure of the first implies involvement in protein absorption and the second in the transport and reabsorption of solutes. The cells of the first distal segment are characterized by deep infolding of the plasma membrane and a rich supply of mitochondria suggesting the presence of a mechanism for ion transport. The second distal segment is composed of cells resembling the chloride cells of fishes and these cells are present in progressively decreasing numbers in the collecting segment and duct system so that only a few are present in the epithelium of the archinephric duct. The "renal chloride cells" possess an abundant network of smooth tubules and numerous mitochondria with a rich supply of cristae. Glycogen is also a conspicuous component of these cells. The presence of "renal chloride cells" in this freshwater holostean, in other relatively primitive freshwater teleosts, and in larval and adult lampreys is discussed with reference to both phylogeny and the need for a special mechanism for renal ion conservation through absorption.

Do Indo-Asians have smaller coronary arteries?

PubMed

Lip, G Y; Rathore, V S; Katira, R; Watson, R D; Singh, S P

1999-08-01

There is a widespread belief that coronary arteries are smaller in Indo-Asians. The aim of the present study was to compare the size of atheroma-free proximal and distal epicardial coronary arteries of Indo-Asians and Caucasians. We analysed normal coronary angiograms from 77 Caucasians and 39 Indo-Asians. The two groups were comparable for dominance of the coronary arteries. Indo-Asian patients had generally smaller coronary arteries, with a statistically significant difference in the mean diameters of the left main coronary artery, proximal, mid and left anterior descending, and proximal and distal right coronary artery segments. There was a non-significant trend towards smaller coronary artery segment diameters for the distal left anterior descending, proximal and distal circumflex, and obtuse marginal artery segments. However, after correction for body surface area, none of these differences in size were statistically significant. Thus, the smaller coronary arteries in Indo-Asian patients were explained by body size alone and were not due to ethnic origin per se. This finding nevertheless has important therapeutic implications, since smaller coronary arteries may give rise to technical difficulties during bypass graft and intervention procedures such as percutaneous transluminal coronary angioplasty, stents and atherectomy. On smaller arteries, atheroma may also give an impression of more severe disease than on larger diameter arteries.

Torsion of the fallopian tube--a late complication of sterilisation.

PubMed

Sivanesaratnam, V

1986-02-01

Torsion of an intact fallopian tube, unaccompanied by torsion of the ipsilateral ovary, was noted as a complication of bilateral tubal occlusion by the Pomeroy method in a 45-year old Indian woman. The sterilization was performed 5 years previously, at the time of Cesarean section delivery. The patient presented with a history of pain in the right iliac fossa. Laparotomy showed that the distal segment of the right fallopian tube was twisted 3 times on the distal mesosalpinx and appeared tense and gangrenous. The right ovary was normal and a 2 cm gap was noted between the proximal and distal segments of the tube. As a rare complication of the Pomeroy method, the gap in the tube can allow the distal mesosalpinx to act as a pedicle, and with a long mesosalpinx, the fimbriated segment of the tube lies free and may swing and twist to produce torsion. The occurrence of torsion is further promoted by a vascular disturbance leading to venous congestion, edema, and increased weight of the free fimbrial end of the tube. In those patients with a history of sterilization, torsion of the fallopian tube should be considered in the differential diagnosis of acute lower abdominal pain. Torsion of the fallopian tube has also been reported following other methods of tubal occlusion, including cautery and clips.

Bilateral en-masse distalization of maxillary posterior teeth with skeletal anchorage: a case report

PubMed Central

Noorollahian, Saeed; Alavi, Shiva; Shirban, Farinaz

2016-01-01

ABSTRACT Objective: The aim of this study was to introduce a new method for bilateral distal movement of the entire maxillary posterior segment. Case report: A 17-year-old girl with Class I skeletal malocclusion (end-to-end molar relationships, deviated midline and space deficiency for left maxillary canine) was referred for orthodontic treatment. She did not accept maxillary first premolars extraction. A modified Hyrax appliance (Dentaurum Ispringen, Germany) was used for bilateral distalization of maxillary posterior teeth simultaneously. Expansion vector was set anteroposteriorly. Posterior legs of Hyrax were welded to first maxillary molar bands. All posterior teeth on each side consolidated with a segment of 0.017 × 0.025-in stainless steel wire from the buccal side. Anterior legs of Hyrax were bent into eyelet form and attached to the anterior palate with two mini-screws (2 × 10 mm) (Jeil Medical Corporation Seoul, South Korea). Hyrax opening rate was 0.8 mm per month. Lateral cephalometric radiographs were used to evaluate the extent of distal movement. 3.5-mm distalization of posterior maxillary teeth was achieved in five months. Results: A nearly bodily distal movement without anchorage loss was obtained. Conclusion: The mini-screw-supported modified Hyrax appliance was found to be helpful for achieving en-masse distal movement of maxillary posterior teeth. PMID:27409657

Prognostic validation of a 17-segment score derived from a 20-segment score for myocardial perfusion SPECT interpretation.

PubMed

Berman, Daniel S; Abidov, Aiden; Kang, Xingping; Hayes, Sean W; Friedman, John D; Sciammarella, Maria G; Cohen, Ishac; Gerlach, James; Waechter, Parker B; Germano, Guido; Hachamovitch, Rory

2004-01-01

Recently, a 17-segment model of the left ventricle has been recommended as an optimally weighted approach for interpreting myocardial perfusion single photon emission computed tomography (SPECT). Methods to convert databases from previous 20- to new 17-segment data and criteria for abnormality for the 17-segment scores are needed. Initially, for derivation of the conversion algorithm, 65 patients were studied (algorithm population) (pilot group, n = 28; validation group, n = 37). Three conversion algorithms were derived: algorithm 1, which used mid, distal, and apical scores; algorithm 2, which used distal and apical scores alone; and algorithm 3, which used maximal scores of the distal septal, lateral, and apical segments in the 20-segment model for 3 corresponding segments of the 17-segment model. The prognosis population comprised 16,020 consecutive patients (mean age, 65 +/- 12 years; 41% women) who had exercise or vasodilator stress technetium 99m sestamibi myocardial perfusion SPECT and were followed up for 2.1 +/- 0.8 years. In this population, 17-segment scores were derived from 20-segment scores by use of algorithm 2, which demonstrated the best agreement with expert 17-segment reading in the algorithm population. The prognostic value of the 20- and 17-segment scores was compared by converting the respective summed scores into percent myocardium abnormal. Conversion algorithm 2 was found to be highly concordant with expert visual analysis by the 17-segment model (r = 0.982; kappa = 0.866) in the algorithm population. In the prognosis population, 456 cardiac deaths occurred during follow-up. When the conversion algorithm was applied, extent and severity of perfusion defects were nearly identical by 20- and derived 17-segment scores. The receiver operating characteristic curve areas by 20- and 17-segment perfusion scores were identical for predicting cardiac death (both 0.77 +/- 0.02, P = not significant). The optimal prognostic cutoff value for either 20- or derived 17-segment models was confirmed to be 5% myocardium abnormal, corresponding to a summed stress score greater than 3. Of note, the 17-segment model demonstrated a trend toward fewer mildly abnormal scans and more normal and severely abnormal scans. An algorithm for conversion of 20-segment perfusion scores to 17-segment scores has been developed that is highly concordant with expert visual analysis by the 17-segment model and provides nearly identical prognostic information. This conversion model may provide a mechanism for comparison of studies analyzed by the 17-segment system with previous studies analyzed by the 20-segment approach.

Distal Predominance of Electrodiagnostic Abnormalities in Early Stage Amyotrophic Lateral Sclerosis.

PubMed

Shayya, Luay; Babu, Suma; Pioro, Erik P; Li, Jianbo; Li, Yuebing

2018-05-09

We compare the electrodiagnostic (EDX) yield of limb muscles in revealing lower motor neuron (LMN) dysfunction by electromyography (EMG) in early stage amyotrophic lateral sclerosis (ALS). Single-site retrospective review Results: This study includes 122 consecutive patients with possible ALS as defined by revised El Escorial Criteria. Distal limb muscles show more frequent EMG abnormalities than proximal muscles. EDX yield is higher in the limb where weakness begins and when clinical signs of LMN dysfunction are evident. Adoption of Awaji criteria increases the yield of EMG positive segments significantly in the cervical (p<0.0005) and lumbosacral regions (P<0.0001), and upgrades 19 patients into probable and 1 patient into definite categories. Electromyographic abnormalities are distal limb-predominant in early stage ALS. A redefinition of an EDX-positive cervical or lumbosacral segment, with an emphasis on distal limb muscles, may result in an earlier ALS diagnosis. This article is protected by copyright. All rights reserved. © 2018 Wiley Periodicals, Inc.

A new Setacheres (Copepoda, Siphonostomatoida, Asterocheridae) associated with Ircinia felix (Duchassaing & Michelotti) (Porifera) from Brazil.

PubMed

Borges, Camila C; Neves, Elizabeth G; Johnsson, Rodrigo

2017-12-08

Recent surveys of the copepod fauna associated with the sponge Ircinia felix (Porifera, Dictyoceratida) in Brazil resulted in the discovery of a new siphonostomatoid species belonging to a recently erected genus of Asterocheridae. Setacheres portobarrensis sp. nov. possesses a 21-segmented antennule, with 3 free distal segments, after the aesthetasc. The third exopodal segment of leg 3 shows a distal seta instead of a spine as in some other congeners. The new species shows several unique features on the third endopodal segment of the antenna, the mandibular stylet, the inner lobe of the maxillule, and setules and spinules located in specific regions of legs 1 to 4. Setacheres portobarrensis sp. nov. follows the same distributional pattern as its congeners, and this is the first record of a siphonostomatoid copepod associated with Ircinia felix.

[Aneurysm of the extracranial portion of the internal carotid artery combined with kinking of its distal segment].

PubMed

Zotov, S P; Shcherbakov, A V; Ufimtsev, M S; Kostromitin, N E; Semashko, T V; Korzina, E N; Tsar'kova, T A; Zharov, K A

Presented herein is a clinical case report regarding successful operation for an aneurysm of the left internal carotid artery (measuring 4.5*8.3 cm) combined with pathological tortuosity in its distal portion. The patient was subjected to aneurysmectomy of the left internal carotid artery with prosthetic repair. Kinking in the distal portion of the aneurysm made it possible with minimal technical difficulties to establish a distal anastomosis during prosthetic repair. The diagnosis of an atherosclerotic-aetiology aneurysm was morphologically confirmed.

Energy neutral: the human foot and ankle subsections combine to produce near zero net mechanical work during walking.

PubMed

Takahashi, Kota Z; Worster, Kate; Bruening, Dustin A

2017-11-13

The human foot and ankle system is equipped with structures that can produce mechanical work through elastic (e.g., Achilles tendon, plantar fascia) or viscoelastic (e.g., heel pad) mechanisms, or by active muscle contractions. Yet, quantifying the work distribution among various subsections of the foot and ankle can be difficult, in large part due to a lack of objective methods for partitioning the forces acting underneath the stance foot. In this study, we deconstructed the mechanical work production during barefoot walking in a segment-by-segment manner (hallux, forefoot, hindfoot, and shank). This was accomplished by isolating the forces acting within each foot segment through controlling the placement of the participants' foot as it contacted a ground-mounted force platform. Combined with an analysis that incorporated non-rigid mechanics, we quantified the total work production distal to each of the four isolated segments. We found that various subsections within the foot and ankle showed disparate work distribution, particularly within structures distal to the hindfoot. When accounting for all sources of positive and negative work distal to the shank (i.e., ankle joint and all foot structures), these structures resembled an energy-neutral system that produced net mechanical work close to zero (-0.012 ± 0.054 J/kg).

Uriniferous tubule: structural and functional organization.

PubMed

Christensen, Erik Ilsø; Wagner, Carsten A; Kaissling, Brigitte

2012-04-01

The uriniferous tubule is divided into the proximal tubule, the intermediate (thin) tubule, the distal tubule and the collecting duct. The present chapter is based on the chapters by Maunsbach and Christensen on the proximal tubule, and by Kaissling and Kriz on the distal tubule and collecting duct in the 1992 edition of the Handbook of Physiology, Renal Physiology. It describes the fine structure (light and electron microscopy) of the entire mammalian uriniferous tubule, mainly in rats, mice, and rabbits. The structural data are complemented by recent data on the location of the major transport- and transport-regulating proteins, revealed by morphological means(immunohistochemistry, immunofluorescence, and/or mRNA in situ hybridization). The structural differences along the uriniferous tubule strictly coincide with the distribution of the major luminal and basolateral transport proteins and receptors and both together provide the basis for the subdivision of the uriniferous tubule into functional subunits. Data on structural adaptation to defined functional changes in vivo and to genetical alterations of specified proteins involved in transepithelial transport importantly deepen our comprehension of the correlation of structure and function in the kidney, of the role of each segment or cell type in the overall renal function,and our understanding of renal pathophysiology. © 2012 American Physiological Society. Compr Physiol 2:933-996, 2012.

Vascular delay of the latissimus dorsi muscle: an essential component of cardiomyoplasty.

PubMed

Carroll, S M; Carroll, C M; Stremel, R W; Heilman, S J; Tobin, G R; Barker, J H

1997-04-01

Cardiomyoplasty (CMP) uses the latissimus dorsi muscle (LDM) to assist the heart in cases of cardiac failure. Distal ischemia and necrosis of the LDM is a recognized complication of CMP that can reduce distal muscle function and the mechanical effectiveness of CMP. Canine (n = 9) LDMs were subjected to a 10-day period of vascular delay followed by a simulated CMP. Two weeks after simulated CMP (corresponding to the healing delay between CMP and the onset of LDM stimulation used in the clinical setting), LDM perfusion was measured in the distal, middle, and proximal segments of the muscle, and circumferential (distal and middle squeezing muscle function) and longitudinal (proximal pulling muscle function) force generation and fatigue rates were measured. The results were compared with the contralateral nondelayed simulated CMP. Muscle perfusion was significantly (p < 0.05) greater in the distal and middle segments of vascular-delayed LDMs. Circumferential muscle force generation and fatigue rates were significantly (p < 0.05) improved in the vascular-delayed LDMs. Vascular delay can significantly improve LDM perfusion and function in a model that closely reflects clinical CMP, and the use of vascular delay may improve clinical outcomes in CMP.

Volar plating for distal radius fractures--do not trust the image intensifier when judging distal subchondral screw length.

PubMed

Park, Derek H; Goldie, Boyd S

2012-09-01

The use of the volar plate to treat distal radius fractures is increasing but despite the theoretical advantages of a volar approach there have been reports of extensor tendon ruptures due to prominent screw tips protruding past the dorsal cortex. The valley in the intermediate column between Lister tubercle and the sigmoid notch of the distal radius makes it difficult to rely on fluoroscopy to judge screw length. Our aim was to quantify the dimensions of this valley and to demonstrate the danger of relying on intraoperative image intensification fluoroscopy to determine lengths of distal screws. We measured the depth of this valley in the intermediate column of the distal radius in 33 patients with computed tomographic (9 patients) or magnetic resonance image (24 patients) scans of the wrist. There was a consistent valley in all images examined [average 1.8 mm (95% confidence interval, 1.6-2.0 mm)]. Thirty-nine percent of wrists had a valley depth of at least 2 mm. Standard lateral views or rotation of the forearm to obtain oblique views does not identify prominent screw tips; and whatever the rotation of the forearm, screw tips protruding beyond dorsal cortex may look as if it is within the bone when in fact it is out. When drilling we suggest noting the depth at which the drill bit just penetrates dorsal cortex and routinely downsize the distal screw length by 2 mm. We caution against relying on flourosocopy when judging the length of the distal subchondral screws.

Haptic Distal Spatial Perception Mediated by Strings: Haptic "Looming"

ERIC Educational Resources Information Center

Cabe, Patrick A.

2011-01-01

Five experiments tested a haptic analog of optical looming, demonstrating string-mediated haptic distal spatial perception. Horizontally collinear hooks supported a weighted string held taut by a blindfolded participant's finger midway between the hooks. At the finger, the angle between string segments increased as the finger approached…

Effect of Vilon and Epithalon on glucose and glycine absorption in various regions of small intestine in aged rats.

PubMed

Khavinson, V Kh; Egorova, V V; Timofeeva, N M; Malinin, V V; Gordova, L A; Gromova, L V

2002-05-01

Vilon (Lys-Glu) and Epithalon (Ala-Glu-Asp-Gly) administered orally for 1 month improved transport characteristics of the small intestine in aged rats. Vilon enhanced passive glucose accumulation in the serous fluid in inverted sac made from the distal region of the small intestine, while Epithalon enhanced this process in the medial region. Vilon stimulated active glucose accumulation in the serous sac of the medial small intestine, Epithalon - in the proximal and distal small intestinal segments. Glycine absorption increased only in the proximal intestinal segment under the effect of Epithalon.

Luminal and systemic signals trigger intestinal adaptation in the juvenile python.

PubMed

Secor, S M; Whang, E E; Lane, J S; Ashley, S W; Diamond, J

2000-12-01

Juvenile pythons undergo large rapid upregulation of intestinal mass and intestinal transporter activities upon feeding. Because it is also easy to do surgery on pythons and to maintain them in the laboratory, we used a python model to examine signals and agents for intestinal adaptation. We surgically isolated the middle third of the small intestine from enteric continuity, leaving its mesenteric nerve and vascular supply intact. Intestinal continuity was restored by an end-to-end anastomosis between the proximal and distal thirds. Within 24 h of the snake's feeding, the reanastomosed proximal and distal segments (receiving luminal nutrients) had upregulated amino acid and glucose uptakes by up to 15-fold, had doubled intestinal mass, and thereby soon achieved total nutrient uptake capacities equal to those of the normal fed full-length intestine. At this time, however, the isolated middle segment, receiving no luminal nutrients, experienced no changes from the fasted state in either nutrient uptakes or in morphology. By 3 days postfeeding, the isolated middle segment had upregulated nutrient uptakes to the same levels as the reanastomosed proximal and distal segments, but it still lacked any appreciable morphological response. These contrasting results for the reanastomosed intestine and for the isolated middle segment suggest that luminal nutrients and/or pancreatic biliary secretions are the agents triggering rapid upregulation of transporters and of intestinal mass and that systemic nerve or hormonal signals later trigger transporter regulation but no trophic response.

Impact of transient or persistent slow flow and adjunctive distal protection on mortality in ST-segment elevation myocardial infarction.

PubMed

Fujii, Toshiharu; Masuda, Naoki; Nakano, Masataka; Nakazawa, Gaku; Shinozaki, Norihiko; Matsukage, Takashi; Ogata, Nobuhiko; Yoshimachi, Fuminobu; Ikari, Yuji

2015-04-01

Routine use of distal protection for ST-segment elevation myocardial infarction (STEMI) is not recommended. The purpose of this study was to analyze the impact of slow flow on mortality after STEMI, and the efficacy of adjunctive distal protection following primary thrombus aspiration. We retrospectively analyzed 414 STEMI patients who underwent primary PCI. Distal protection was used following primary thrombus aspiration only when the operator judged the patient to be at high risk of slow flow. Patients were divided into 3 groups: those receiving no thrombus aspiration (A- Group), thrombus aspiration without distal protection (A+/D- Group) or a combination of aspiration with distal protection (A+/D+ Group). Slow flow/no reflow was characterized as transient or persistent. The A-, A+/D-, and A+/D+ Groups consisted of 28.5 % (n = 118), 44.4 % (n = 184), and 27.1 % (n = 112) of patients, respectively. All-cause mortality at 180 days was 6.8 % without slow flow, 14.1 % with transient and 44.4 % with persistent slow flow (P < 0.0001), but was similar whether or not distal protection was used among these groups complicated without slow flow (A-, 8.7 %; A+/D-, 6.3 %; A+/D+, 4.3 %; P = 0.5854). However, in cases complicated with transient or persistent slow flow, distal protection reduced all-cause mortality to 38.5 % (A-), 23.3 % (A+/D-), and 10.8 % (A+/D+) at 180 days (P = 0.0114). Our data confirm that routine distal protection is not to be recommended. However, it is suggested that it could reduce mortality of patients with slow flow. Predicting slow flow accurately before PCI, however, remains a challenge.

Effect of Seed Position on Parental Plant on Proportion of Seeds Produced with Nondeep and Intermediate Physiological Dormancy

PubMed Central

Lu, Juan J.; Tan, Dun Y.; Baskin, Carol C.; Baskin, Jerry M.

2017-01-01

The position in which seeds develop on the parental plant can have an effect on dormancy-break and germination. We tested the hypothesis that the proportion of seeds with intermediate physiological dormancy (PD) produced in the proximal position on a raceme of Isatis violascens plants is higher than that produced in the distal position, and further that this difference is related to temperature during seed development. Plants were watered at 3-day intervals, and silicles and seeds from the proximal (early) and distal (late) positions of racemes on the same plants were collected separately and tested for germination. After 0 and 6 months dry storage at room temperature (afterripening), silicles and seeds were cold stratified for 0–16 weeks and tested for germination. Mean daily maximum and minimum temperatures during development/maturation of the two groups of seeds did not differ. A higher proportion of seeds with the intermediate level than with the nondeep level of PD was produced by silicles in the proximal position than by those in the distal position, while the proportion of seeds with nondeep PD was higher in the distal than in the proximal position of the raceme. The differences were not due only to seed mass. Since temperature and soil moisture conditions were the same during development of the seeds in the raceme, differences in proportion of seeds with intermediate and nondeep PD are attributed to position on parental plant. The ecological consequence of this phenomenon is that it ensures diversity in dormancy-breaking and germination characteristics within a seed cohort, a probable bet-hedging strategy. This is the first demonstration of position effects on level of PD in the offspring. PMID:28232842

A mathematical analysis to address the 6 degree-of-freedom segmental power imbalance.

PubMed

Ebrahimi, Anahid; Collins, John D; Kepple, Thomas M; Takahashi, Kota Z; Higginson, Jill S; Stanhope, Steven J

2018-01-03

Segmental power is used in human movement analyses to indicate the source and net rate of energy transfer between the rigid bodies of biomechanical models. Segmental power calculations are performed using segment endpoint dynamics (kinetic method). A theoretically equivalent method is to measure the rate of change in a segment's mechanical energy state (kinematic method). However, these two methods have not produced experimentally equivalent results for segments proximal to the foot, with the difference in methods deemed the "power imbalance." In a 6 degree-of-freedom model, segments move independently, resulting in relative segment endpoint displacement and non-equivalent segment endpoint velocities at a joint. In the kinetic method, a segment's distal end translational velocity may be defined either at the anatomical end of the segment or at the location of the joint center (defined here as the proximal end of the adjacent distal segment). Our mathematical derivations revealed the power imbalance between the kinetic method using the anatomical definition and the kinematic method can be explained by power due to relative segment endpoint displacement. In this study, we tested this analytical prediction through experimental gait data from nine healthy subjects walking at a typical speed. The average absolute segmental power imbalance was reduced from 0.023 to 0.046 W/kg using the anatomical definition to ≤0.001 W/kg using the joint center definition in the kinetic method (95.56-98.39% reduction). Power due to relative segment endpoint displacement in segmental power analyses is substantial and should be considered in analyzing energetic flow into and between segments. Copyright © 2017 Elsevier Ltd. All rights reserved.

Depth of intrastromal corneal ring segments by OCT.

PubMed

Naftali, Modi; Jabaly-Habib, Haneen

2013-01-01

To compare the depth of intrastromal corneal ring segments (ICRS) with the expected depth value using optical coherence tomography (OCT). This was a retrospective comparative study in an ophthalmic unit in a government hospital, the Baruch Padeh Medical Center, Poriya, Israel. Ten eyes of 8 patients with 18 ICRS were reviewed. Eleven segments were Intacs (Addition Technology, Inc.) and 7 Kerarings (Mediphacos). Using anterior segment OCT (OPKO OTI) the shortest distance from the epithelium to the segment at 3 points was measured for each segment. The 3 points are proximal, middle, and distal to the incision. The mean depth of the 18 segments was 360±68 µm. The mean maximal and minimal depths were 383±70 and 336±72 µm, respectively. The mean depths of the distal, central, and proximal point measurements of all ICRS were 358±79, 361±77, and 362±59 µm, respectively; no significant difference was found. No part of the segments tended to be more superficial than others (p=0.98). There was no significant difference between Intacs and Kerarings depths (p=0.43). There was a significant difference between the expected ICRS depth and the OCT measurements (mean 480±20) and 360±68), respectively. The ICRS actual depth was less than expected. There was mild variability in segment depth, both between segments and along the same segment. No significant difference was found between the depth of Intacs and Kerarings.

Anatomic assessment of sympathetic peri-arterial renal nerves in man.

PubMed

Sakakura, Kenichi; Ladich, Elena; Cheng, Qi; Otsuka, Fumiyuki; Yahagi, Kazuyuki; Fowler, David R; Kolodgie, Frank D; Virmani, Renu; Joner, Michael

2014-08-19

Although renal sympathetic denervation therapy has shown promising results in patients with resistant hypertension, the human anatomy of peri-arterial renal nerves is poorly understood. The aim of our study was to investigate the anatomic distribution of peri-arterial sympathetic nerves around human renal arteries. Bilateral renal arteries were collected from human autopsy subjects, and peri-arterial renal nerve anatomy was examined by using morphometric software. The ratio of afferent to efferent nerve fibers was investigated by dual immunofluorescence staining using antibodies targeted for anti-tyrosine hydroxylase and anti-calcitonin gene-related peptide. A total of 10,329 nerves were identified from 20 (12 hypertensive and 8 nonhypertensive) patients. The mean individual number of nerves in the proximal and middle segments was similar (39.6 ± 16.7 per section and 39.9 ± 1 3.9 per section), whereas the distal segment showed fewer nerves (33.6 ± 13.1 per section) (p = 0.01). Mean subject-specific nerve distance to arterial lumen was greatest in proximal segments (3.40 ± 0.78 mm), followed by middle segments (3.10 ± 0.69 mm), and least in distal segments (2.60 ± 0.77 mm) (p < 0.001). The mean number of nerves in the ventral region (11.0 ± 3.5 per section) was greater compared with the dorsal region (6.2 ± 3.0 per section) (p < 0.001). Efferent nerve fibers were predominant (tyrosine hydroxylase/calcitonin gene-related peptide ratio 25.1 ± 33.4; p < 0.0001). Nerve anatomy in hypertensive patients was not considerably different compared with nonhypertensive patients. The density of peri-arterial renal sympathetic nerve fibers is lower in distal segments and dorsal locations. There is a clear predominance of efferent nerve fibers, with decreasing prevalence of afferent nerves from proximal to distal peri-arterial and renal parenchyma. Understanding these anatomic patterns is important for refinement of renal denervation procedures. Copyright © 2014 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Renal artery nerve distribution and density in the porcine model: biologic implications for the development of radiofrequency ablation therapies.

PubMed

Tellez, Armando; Rousselle, Serge; Palmieri, Taylor; Rate, William R; Wicks, Joan; Degrange, Ashley; Hyon, Chelsea M; Gongora, Carlos A; Hart, Randy; Grundy, Will; Kaluza, Greg L; Granada, Juan F

2013-12-01

Catheter-based renal artery denervation has demonstrated to be effective in decreasing blood pressure among patients with refractory hypertension. The anatomic distribution of renal artery nerves may influence the safety and efficacy profile of this procedure. We aimed to describe the anatomic distribution and density of periarterial renal nerves in the porcine model. Thirty arterial renal sections were included in the analysis by harvesting a tissue block containing the renal arteries and perirenal tissue from each animal. Each artery was divided into 3 segments (proximal, mid, and distal) and assessed for total number, size, and depth of the nerves according to the location. Nerve counts were greatest proximally (45.62% of the total nerves) and decreased gradually distally (mid, 24.58%; distal, 29.79%). The distribution in nerve size was similar across all 3 sections (∼40% of the nerves, 50-100 μm; ∼30%, 0-50 μm; ∼20%, 100-200 μm; and ∼10%, 200-500 μm). In the arterial segments ∼45% of the nerves were located within 2 mm from the arterial wall whereas ∼52% of all nerves were located within 2.5 mm from the arterial wall. Sympathetic efferent fibers outnumbered sensory afferent fibers overwhelmingly, intermixed within the nerve bundle. In the porcine model, renal artery nerves are seen more frequently in the proximal segment of the artery. Nerve size distribution appears to be homogeneous throughout the artery length. Nerve bundles progress closer to the arterial wall in the distal segments of the artery. This anatomic distribution may have implications for the future development of renal denervation therapies. Crown Copyright © 2013. Published by Mosby, Inc. All rights reserved.

The rectourogenital connection in anorectal malformations is an ectopic anal canal.

PubMed

Rintala, R; Lindahl, H; Sariola, H; Rapola, J; Louhimo, I

1990-06-01

Histological investigation of the rectal blind pouch and rectourogenital or rectoperineal connection was performed in 10 patients with high or intermediate anorectal malformations. Nine of the patients underwent postoperative manometric evaluation. In nine of the 10 patients, transitional epithelium typical of the normal anal canal could be found in the distal rectum or rectal end of the fistulous connection. The zone of transitional epithelium was aganglionic and showed abnormally strong acetylcholinesterase reaction. A positive rectoanal inhibitory reflex was found manometrically in all cases in which the distal rectal pouch was utilized in the reconstruction of the anal canal. The slow pressure wave activity of the reconstructed anal canal was characteristic of a normal anal canal. The manometric evidence strongly suggests that there is a functional internal sphincter in high and intermediate anorectal malformations. The present study shows that in anorectal malformations the distal rectal pouch with the fistulous connection is actually an ectopic anal canal.

Micromorphology of Skeletonized and Pedicled Internal Thoracic and Radial Arteries.

PubMed

Mamchur, Sergey; Bokhan, Nikita; Vecherskii, Yuri; Malyshenko, Egor

2015-01-01

The objective of the study was to estimate the internal thoracic arteries (ITA) and radial arteries (RA) micromorphologic features by light microscopy after harvesting them using the skeletonization and pedicled methods in patients undergoing coronary artery bypass grafting. The micromorphologic characteristics of ITA and RA were studied by luminous microscopy in 61 patients undergoing coronary artery bypass grafting. A total of 122 ITA and RA segments harvested during surgery, fixed in formalin, and stained with hematoxiline and eosin were evaluated. The mean intima-media thickness of ITA was 9.2 and 134.7 µm and that of RA was 9.1 and 334.2 µm, respectively. In the distal segment of ITA the media-intima relation was 1.5 times bigger than in the proximal segment. None of ITA specimens contained atherosclerotic plaques or lipid inclusions. Atherosclerotic plaques were found in 3 (5%) RA specimens. Other degenerative changes were detected in 30%-74.2% of the specimens: splitting of internal elastic lamina, reduced tortuosity of the internal elastic lamina, and thickening and detachment of the intima; their incidence was associated with the skeletonization of the vessels. In conclusion, the incidence of ITA and RA degenerative changes varies from 30%-74.2% and its increase is associated with the skeletonization of the vessels, which is statistically significant. The media of the RA is 2.5 times thicker than that of the ITA (P < 0.01). This fact shows that RA has higher spasmogenic potential than that of ITA. The distal segment of the ITA has 1.5 times bigger media-intima relation than the proximal segment. Therefore, in case of enough graft length, it is recommended to avoid the distal segment and cut it off. Copyright © 2015 Elsevier Inc. All rights reserved.

The morphological substrate for Renal Denervation: Nerve distribution patterns and parasympathetic nerves. A post-mortem histological study.

PubMed

van Amsterdam, Wouter A C; Blankestijn, Peter J; Goldschmeding, Roel; Bleys, Ronald L A W

2016-03-01

Renal Denervation as a possible treatment for hypertension has been studied extensively, but knowledge on the distribution of nerves surrounding the renal artery is still incomplete. While sympathetic and sensory nerves have been demonstrated, there is no mention of the presence of parasympathetic nerve fibers. To provide a description of the distribution patterns of the renal nerves in man, and, in addition, provide a detailed representation of the relative contribution of the sympathetic, parasympathetic and afferent divisions of the autonomic nervous system. Renal arteries of human cadavers were each divided into four longitudinal segments and immunohistochemically stained with specific markers for afferent, parasympathetic and sympathetic nerves. Nerve fibers were semi-automatically quantified by computerized image analysis, and expressed as cross-sectional area relative to the distance to the lumen. A total of 3372 nerve segments were identified in 8 arteries of 7 cadavers. Sympathetic, parasympathetic and afferent nerves contributed for 73.5% (95% CI: 65.4-81.5%), 17.9% (10.7-25.1%) and 8.7% (5.0-12.3%) of the total cross-sectional nerve area, respectively. Nerves are closer to the lumen in more distal segments and larger bundles that presumably innervate the kidney lie at 1-3.5mm distance from the lumen. The tissue-penetration depth of the ablation required to destroy 50% of the nerve fibers is 2.37 mm in the proximal segment and 1.78 mm in the most distal segments. Sympathetic, parasympathetic and afferent nerves exist in the vicinity of the renal artery. The results warrant further investigation of the role of the parasympathetic nervous system on renal physiology, and may contribute to refinement of the procedure by focusing the ablation on the most distal segment. Copyright © 2015 Elsevier GmbH. All rights reserved.

Essential roles for lines in mediating leg and antennal proximodistal patterning and generating a stable Notch signaling interface at segment borders.

PubMed

Greenberg, Lina; Hatini, Victor

2009-06-01

The Drosophila leg imaginal disc provides a paradigm with which to understand the fundamental developmental mechanisms that generate an intricate appendage structure. Leg formation depends on the subdivision of the leg proximodistal (PD) axis into broad domains by the leg gap genes. The leg gap genes act combinatorially to initiate the expression of the Notch ligands Delta (Dl) and Serrate (Ser) in a segmental pattern. Dl and Ser induce the expression of a set of transcriptional regulators along the segment border, which mediate leg segment growth and joint morphogenesis. Here we show that Lines accumulates in nuclei in the presumptive tarsus and the inter-joints of proximal leg segments and governs the formation of these structures by destabilizing the nuclear protein Bowl. Across the presumptive tarsus, lines modulates the opposing expression landscapes of the leg gap gene dachshund (dac) and the tarsal PD genes, bric-a-brac 2 (bab), apterous (ap) and BarH1 (Bar). In this manner, lines inhibits proximal tarsal fates and promotes medial and distal tarsal fates. Across proximal leg segments, lines antagonizes bowl to promote Dl expression by relief-of-repression. In turn, Dl signals asymmetrically to stabilize Bowl in adjacent distal cells. Bowl, then, acts cell-autonomously, together with one or more redundant factors, to repress Dl expression. Together, lines and bowl act as a binary switch to generate a stable Notch signaling interface between Dl-expressing cells and adjacent distal cell. lines plays analogous roles in developing antennae, which are serially homologous to legs, suggesting evolutionarily conserved roles for lines in ventral appendage formation.

Sensory conduction of the sural nerve in polyneuropathy.

PubMed

Burke, D; Skuse, N F; Lethlean, A K

1974-06-01

Using surface electrodes, sensory nerve action potentials (SAP) have been recorded in the proximal segment (mid-calf to lateral malleolus) and the distal segment (lateral malleolus to toe 5) of the sural nerve and in the median nerve in 79 control subjects. The values obtained for the distal segment of the sural nerve varied widely and in seven apparently normal subjects no SAP could be distinguished. In the proximal segment conduction velocities were over 40 m/s and there was no significant change with age, unlike the median nerve in which a highly significant slowing occurred with age. Comparison of the results of sural and median sensory conduction studies in 300 consecutive patients screened for sensory polyneuropathy confirms the value of sural nerve sensory studies as a routine screening test, and confirms the belief that the changes in polyneuropathy are usually more prominent in lower limb nerves. It is therefore suggested that studies of sural sensory conduction form the single most useful test in the diagnosis of sensory polyneuropathy.

Comparative analysis of isodisomic and heterodisomic segments in cases with maternal uniparental disomy 14 suggests more than one imprinted region.

PubMed

Kotzot, D

2001-09-01

The results of molecular investigations of 21 cases with complete or segmental maternal uniparental disomy (UPD) 14 published in the literature were compared with respect to isodisomic and heterodisomic segments. The aim of the study was to find hints toward imprinted regions other than the recently defined imprinted segment 14q32. Three regions with no isodisomic molecular marker were found. The most distal of these regions located on 14q32.12 and 14q32.13 supports the hypothesis of genomic imprinting as the cause of the maternal UPD 14 phenotype by synteny to the maternally imprinted region on mouse distal chromosome 12 and correlation with the recently defined imprinting cluster on human chromosome 14q32. The other two heterodisomic areas located on 14q11.2-->14q12 and 14q21.1-->14q31.2 are hints toward one or more additional regions of genomic imprinting on human chromosome 14.

Histologic definition of gastro-esophageal reflux disease.

PubMed

Chandrasoma, Parakrama T

2013-07-01

To review recent data supporting the development of new histology-based definitions of gastro-esophageal reflux disease (GERD). Three precisely definable columnar epithelial types--cardiac, oxyntocardiac and intestinal--may be interposed between esophageal squamous epithelium and gastric oxyntic (acid secreting) mucosa. This enables definition of a new histologic concept: the squamo-oxyntic gap. The squamo-oxyntic gap is zero or very small in autopsies performed on patients without evidence of GERD. The gap progressively increases in length with the severity of GERD, indicating that the squamo-oxyntic gap is a marker for chronic GERD. The distal part of the gap lines gastric-type rugal folds and, therefore, is distal to the present endoscopic definition of the gastro-esophageal junction. I contend that this distal gap segment (which has esophageal submucosal glands) is actually the dilated distal esophagus; this is the pathologic correlate of destruction of the abdominal segment of the lower esophageal sphincter. The dilated distal esophagus is mistaken for 'gastric cardia' by present endoscopic definitions. I believe that these data support the adoption of novel histologic definitions of GERD as follows: the presence of any squamo-oxyntic gap defines GERD; the length of the gap is a measure of severity of chronic GERD; and the presence of intestinal metaplasia in the gap defines Barrett esophagus and cancer risk.

Towards positional cloning of the locus for benign neonatal epilepsy (EBN1) on chromosome 20

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

Schubert, S.; Laccone, F.; Hansmann, I.

1994-09-01

Benign neonatal epilepsy is characterized by tonic-clonic and generalized convulsions appearing during the neonatal period and clearing most often by the age of 2 years. EBN, a rare example of primary epilepsy, follows an autosomal dominant mode of inheritance with high penetrance. One locus for EBN (EBN1) was assigned by linkage analysis to the distal 20q segment in proximity to D20S19 and D20S20. The association of 20q sequences with seizures is also underlined by the observation that all 10 probands known with a ring 20 disclose seizures. For positional cloning of the respective locus at 20q13.3, we characterized segmental monosomymore » in two probands with r(20) and in one proband with a translocation t(10q;20q). The latter proband has a dicentric chromosome 10;20 with breakpoints very distally at 10q and 20q, and seizures similar to those in EBN. Segmental monosomy was investigated by FISH, Southerns and PCR for microsatellites assuming that the respective phenotype, i.e. seizures, is due to loss of 20q sequences (loss of gene function). Probes were used for D20S19, D20S20, D20S24, D20S26, D20S64, D20S102, D20S171, DS20S173, cos23D11, cos35, cos54, as well as for the genes CHRNA4, EDN3, GNAS1, KCNB1, MC3. All of these genes are reasonable candidates for EBN1, due to their function and/or expression pattern. Segmental monosomy for the distal 20q segment was disclosed in the proband with dic(10q;20q) for all loci distal from the critical marker D20S20 and including one of the above genes. In none of the two r(20) probands was any of the distal 20q-markers was found to be deleted, however. It is assumed that seizures with these probands should result from other mechanisms, e.g., by an altered function of respective genes resulting from ring formation. The gene deleted in our proband with dic(10q;20q) is a first candidate gene for EBN1 and is being investigated with respect to its significance for disease manifestation in EBN1.« less

Estimation of Total Length of Femur from its Proximal and Distal Segmental Measurements of Disarticulated Femur Bones of Nepalese Population using Regression Equation Method.

PubMed

Khanal, Laxman; Shah, Sandip; Koirala, Sarun

2017-03-01

Length of long bones is taken as an important contributor for estimating one of the four elements of forensic anthropology i.e., stature of the individual. Since physical characteristics of the individual differ among different groups of population, population specific studies are needed for estimating the total length of femur from its segment measurements. Since femur is not always recovered intact in forensic cases, it was the aim of this study to derive regression equations from measurements of proximal and distal fragments in Nepalese population. A cross-sectional study was done among 60 dry femora (30 from each side) without sex determination in anthropometry laboratory. Along with maximum femoral length, four proximal and four distal segmental measurements were measured following the standard method with the help of osteometric board, measuring tape and digital Vernier's caliper. Bones with gross defects were excluded from the study. Measured values were recorded separately for right and left side. Statistical Package for Social Science (SPSS version 11.5) was used for statistical analysis. The value of segmental measurements were different between right and left side but statistical difference was not significant except for depth of medial condyle (p=0.02). All the measurements were positively correlated and found to have linear relationship with the femoral length. With the help of regression equation, femoral length can be calculated from the segmental measurements; and then femoral length can be used to calculate the stature of the individual. The data collected may contribute in the analysis of forensic bone remains in study population.

Altered ulnar nerve kinematic behavior in a cadaver model of entrapment.

PubMed

Mahan, Mark A; Vaz, Kenneth M; Weingarten, David; Brown, Justin M; Shah, Sameer B

2015-06-01

Ulnar nerve entrapment at the elbow is more than a compressive lesion of the nerve. The tensile biomechanical consequences of entrapment are currently marginally understood. To evaluate the effects of tethering on the kinematics of the ulnar nerve as a model of entrapment neuropathy. The ulnar nerve was exposed in 7 fresh cadaver arms, and markers were placed at 1-cm increments along the nerve, centered on the retrocondylar region. Baseline translation (pure sliding) and strain (stretch) were measured in response to progressively increasing tension produced by varying configurations of elbow flexion and wrist extension. Then the nerves were tethered by suturing to the cubital tunnel retinaculum and again exposed to progressively increasing tension from joint positioning. In the native condition, for all joint configurations, the articular segment of the ulnar nerve exhibited greater strain than segments proximal and distal to the elbow, with a maximum strain of 28 ± 1% and translation of 11.6 ± 1.8 mm distally. Tethering the ulnar nerve suppressed translation, and the distal segment experienced strains that were more than 50% greater than its maximum strain in an untethered state. This work provides a framework for evaluating regional nerve kinematics. Suppressed translation due to tethering shifted the location of high strain from articular to more distal regions of the ulnar nerve. The authors hypothesize that deformation is thus shifted to a region of the nerve less accustomed to high strains, thereby contributing to the development of ulnar neuropathy.

Fatal methadone intoxication in an infant listed as a homicide.

PubMed

Bonsignore, Alessandro; Groppi, Angelo; Ventura, Francesco; De Stefano, Francesco; Palmiere, Cristian

2016-09-01

Voluntary methadone administration for the purpose of sedation eventually resulting in the infant's death is extremely infrequent, though it has been observed. In this report, we describe an autopsy case pertaining to a 32-month-old infant who was repeatedly exposed to methadone by his parents. Autopsy revealed a coarctation of the aorta with a focal stenosis located at the junction of the distal aortic arch and the descending aorta. Left ventricular hypertrophy was also observed. Both these findings were considered to not have played a role in the child's death. Methadone was detected in the femoral blood (0.633 mg/l), urine (5.25 mg/l), bile (2.64 mg/l), and gastric contents (1.08 mg). A segmental hair analysis showed the presence of methadone and morphine in both the proximal and distal portion of the lock. Methadone was also detected in nail samples. A segmental hair analysis performed on the younger brother of the deceased revealed the presence of methadone and morphine in both the proximal and distal segments, as well as the presence of 6-monoacetylmorphine exclusively in the distal portion. Though the parents denied any involvement in methadone administration or exposure for the purpose of sedation, the manner of death was listed as homicide. The case emphasizes the usefulness of hair analysis to identify threatening situations for the children of drug-dependent parents and possibly support measures by the authorities to recognize and intervene in these potentially fatal situations.

Segmented lateral dyke growth in a rifting event at Bárðarbunga volcanic system, Iceland.

PubMed

Sigmundsson, Freysteinn; Hooper, Andrew; Hreinsdóttir, Sigrún; Vogfjörd, Kristín S; Ófeigsson, Benedikt G; Heimisson, Elías Rafn; Dumont, Stéphanie; Parks, Michelle; Spaans, Karsten; Gudmundsson, Gunnar B; Drouin, Vincent; Árnadóttir, Thóra; Jónsdóttir, Kristín; Gudmundsson, Magnús T; Högnadóttir, Thórdís; Fridriksdóttir, Hildur María; Hensch, Martin; Einarsson, Páll; Magnússon, Eyjólfur; Samsonov, Sergey; Brandsdóttir, Bryndís; White, Robert S; Ágústsdóttir, Thorbjörg; Greenfield, Tim; Green, Robert G; Hjartardóttir, Ásta Rut; Pedersen, Rikke; Bennett, Richard A; Geirsson, Halldór; La Femina, Peter C; Björnsson, Helgi; Pálsson, Finnur; Sturkell, Erik; Bean, Christopher J; Möllhoff, Martin; Braiden, Aoife K; Eibl, Eva P S

2015-01-08

Crust at many divergent plate boundaries forms primarily by the injection of vertical sheet-like dykes, some tens of kilometres long. Previous models of rifting events indicate either lateral dyke growth away from a feeding source, with propagation rates decreasing as the dyke lengthens, or magma flowing vertically into dykes from an underlying source, with the role of topography on the evolution of lateral dykes not clear. Here we show how a recent segmented dyke intrusion in the Bárðarbunga volcanic system grew laterally for more than 45 kilometres at a variable rate, with topography influencing the direction of propagation. Barriers at the ends of each segment were overcome by the build-up of pressure in the dyke end; then a new segment formed and dyke lengthening temporarily peaked. The dyke evolution, which occurred primarily over 14 days, was revealed by propagating seismicity, ground deformation mapped by Global Positioning System (GPS), interferometric analysis of satellite radar images (InSAR), and graben formation. The strike of the dyke segments varies from an initially radial direction away from the Bárðarbunga caldera, towards alignment with that expected from regional stress at the distal end. A model minimizing the combined strain and gravitational potential energy explains the propagation path. Dyke opening and seismicity focused at the most distal segment at any given time, and were simultaneous with magma source deflation and slow collapse at the Bárðarbunga caldera, accompanied by a series of magnitude M > 5 earthquakes. Dyke growth was slowed down by an effusive fissure eruption near the end of the dyke. Lateral dyke growth with segment barrier breaking by pressure build-up in the dyke distal end explains how focused upwelling of magma under central volcanoes is effectively redistributed over long distances to create new upper crust at divergent plate boundaries.

Segmented SiGe-PbTe couples

NASA Technical Reports Server (NTRS)

Eggers, P. E.; Mueller, J. J.

1969-01-01

New design of segmented couples incorporates an intermediate junction contacted by pressure, and eliminates transition members that bond materials differing in thermal expansion. Development of a reproducible and reliable intermediate junction between PbTe and SiGe will be applicable to direct conversion of energy.

[Closure of pancreas stump after distal and segmental resection : Suture, stapler, coverage or anastomosis?

PubMed

Michalski, C W; Tramelli, P; Büchler, M W; Hackert, T

2017-01-01

Postoperative pancreatic fistulas represent the most frequent complication after distal and segmental pancreatectomy and occur with a frequency of up to 50 %. There are many technical variations of pancreatic stump treatment for reduction of fistula rates after distal resection. Most of these techniques have only been analyzed in retrospective studies and the evidence for or against a specific technique is low. Several retrospective trials have been conducted with good results to compare suturing with stapled closure of the remnant and to assess the effect of a vascularized falciform ligament patch in reducing postoperative pancreatic fistula; however, in a recently published randomized trial, which analyzed closure of the remnant with a pancreaticojejunostomy compared to standard closure, these results could not be confirmed. Because stapler resection and closure is the most commonly used technique in laparoscopic distal pancreatectomy, there are a large number of studies which assessed various novel methods of improving stapling. Extended stapler compression time and mesh augmentation of the stapler line can be valid methods to reduce fistula rates. Central pancreatectomy is a relatively rarely used procedure where the right-sided pancreatic remnant is closed in the same fashion as during distal pancreatectomy and the left-sided remnant is connected to the intestines with a pancreaticojejunostomy or pancreaticogastrostomy. In conclusion, postoperative pancreatic fistula rates are still a relevant clinical problem after distal pancreatectomy and further studies on potentially improved novel techniques are required.

Histology of the terminal end of the distal rectal pouch and fistula region in anorectal malformations.

PubMed

Gangopadhyay, A N; Upadhyaya, Vijai D; Gupta, D K; Agarwal, D K; Sharma, S P; Arya, N C

2008-10-01

Until recently, surgeons have been posed with a dilemma---whether or not they should preserve the terminal end of the distal rectal pouch and the fistula region in anorectal malformations (ARMs). A detailed histological study of this region was conducted to establish a consensus for preserving or excising this region for reconstruction of ARMs. Histopathological examination using haematoxylin and eosin-stained sections of the terminal portion of the distal rectal pouch and proximal portion of the rectourogenital or rectoperineal connection was performed in 60 cases of high, intermediate and low ARMs. Distorted internal sphincter was present in 93.3% of high, 90% of intermediate and 100% of low ARMs. The proximal fistula region was lined by transitional epithelium in 50% of cases, and anal glands were present in 83.3% and anal crypts in 68.3% of cases. The rectal pouch in the region of the internal sphincter and fistula was aganglionic in all cases. This study shows that the terminal end of the distal rectal pouch and proximal fistula region possess distorted anal features with aganglionosis, and contradicts the recommendation that this region should be reconstructed in patients with malformations.

Measurement of radial bone mineral density in patients after heart transplantation.

PubMed

Garlicki, A M; Orchowski, F; Myrdko, T; Wójcik, S; Czerwiński, E; Kukiełka, R; Kapelak, B; Dziatkowiak, A

1996-01-01

Limited physical activity, steroidotherapy and immunosuppression are known risk factors for the development of osteoporosis. The purpose of our current work was to investigate whether patients after heart transplantation (Htx) have an increased incidence of osteoporosis. We compared bone mineral density (BMD) in 32 post-transplant patients with a reference group of 1548 healthy age-matched males. Measurement of BMD was carried out with a Dtx 100 Osteometer on the distal and ultradistal segment of the non-dominant radius. Our results revealed a decreased BMD in HTx patients ranging from 6.9 to 10% in the ultradistal (p = 0.0446) and from 0.4 to 3.5% in the distal segment (p = 0.0593).

Adductor magnus: An EMG investigation into proximal and distal portions and direction specific action.

PubMed

Benn, Matthew L; Pizzari, Tania; Rath, Leanne; Tucker, Kylie; Semciw, Adam I

2018-05-01

Cadaveric studies indicate that adductor magnus is structurally partitioned into at least two regions. The aim of this study was to investigate the direction-specific actions of proximal and distal portions of adductor magnus, and in doing so determine if these segments have distinct functional roles. Fine-wire EMG electrodes were inserted into two portions of adductor magnus of 12 healthy young adults. Muscle activity was recorded during maximum voluntary isometric contractions (MVICs) across eight tests (hip flexion/extension, internal/external rotation, abduction, and adduction at 0°, 45°, and 90° hip flexion). Median activity within each action (normalized to peak) was compared between segments using repeated measures nonparametric tests (α = 0.05). An effect size (ES = z-score/√sample size) was calculated to determine the magnitude of difference between muscle segments. The relative contribution of each muscle segment differed significantly during internal rotation (P < 0.001; ES = 0.88) and external rotation (P = 0.003, ES = 0.79). The distal portion was most active during extension [median (interquartile range); 100(0)% MVIC)] and internal rotation [58(34)% MVIC]. The proximal portion was most active during extension [100(49)% MVIC] and adduction [59(64)%MVIC], with low level activity during external rotation [15(41)%MVIC]. This study suggests that adductor magnus has at least two functionally unique regions. Differences were most evident during rotation. The different direction-specific actions may imply that each segment performs separate roles in hip stability and movement. These findings may have implications on injury prevention and rehabilitation for adductor-related groin injuries, hamstring strain injury, and hip pathology. Clin. Anat. 31:535-543, 2018. © 2018 Wiley Periodicals, Inc. © 2018 Wiley Periodicals, Inc.

Differential regulation of ROMK (Kir1.1) in distal nephron segments by dietary potassium.

PubMed

Wade, James B; Fang, Liang; Coleman, Richard A; Liu, Jie; Grimm, P Richard; Wang, Tong; Welling, Paul A

2011-06-01

ROMK channels are well-known to play a central role in renal K secretion, but the absence of highly specific and avid-ROMK antibodies has presented significant roadblocks toward mapping the extent of expression along the entire distal nephron and determining whether surface density of these channels is regulated in response to physiological stimuli. Here, we prepared new ROMK antibodies verified to be highly specific, using ROMK knockout mice as a control. Characterization with segmental markers revealed a more extensive pattern of ROMK expression along the entire distal nephron than previously thought, localizing to distal convoluted tubule regions, DCT1 and DCT2; the connecting tubule (CNT); and cortical collecting duct (CD). ROMK was diffusely distributed in intracellular compartments and at the apical membrane of each tubular region. Apical labeling was significantly increased by high-K diet in DCT2, CNT1, CNT2, and CD (P < 0.05) but not in DCT1. Consistent with the large increase in apical ROMK, dramatically increased mature glycosylation was observed following dietary potassium augmentation. We conclude 1) our new antibody provides a unique tool to characterize ROMK channel localization and expression and 2) high-K diet causes a large increase in apical expression of ROMK in DCT2, CNT, and CD but not in DCT1, indicating that different regulatory mechanisms are involved in K diet-regulated ROMK channel functions in the distal nephron.

Evolving concepts on regulation and function of renin in distal nephron

PubMed Central

Prieto, Minolfa C.; Gonzalez, Alexis A.

2012-01-01

Sustained stimulation of the intrarenal/intratubular renin–angiotensin system in a setting of elevated arterial pressure elicits renal vasoconstriction, increased sodium reabsorption, proliferation, fibrosis, and eventual renal injury. Activation of luminal AT1 receptors in proximal and distal nephron segments by local Ang II formation stimulates various transport systems. Augmented angiotensinogen (AGT) production by proximal tubule cells increases AGT secretion contributing to increased proximal Ang II levels and leading to spillover of AGT into the distal nephron segments, as reflected by increased urinary AGT excretion. The increased distal delivery of AGT provides substrate for renin, which is expressed in principal cells of the collecting tubule and collecting ducts, and is also stimulated by AT1 receptor activation. Renin and prorenin are secreted into the tubular lumen and act on the AGT delivered from the proximal tubule to form more Ang I. The catalytic actions of renin and or prorenin may be enhanced by binding to prorenin receptors on the intercalated cells or soluble prorenin receptor secreted into the tubular fluid. There is also increased luminal angiotensin converting enzyme in collecting ducts facilitating Ang II formation leading to stimulation of sodium reabsorption via sodium channel and sodium/chloride co-transporter. Thus, increased collecting duct renin contributes to Ang II-dependent hypertension by augmenting distal nephron intra-tubular Ang II formation leading to sustained stimulation of sodium reabsorption and progression of hypertension. PMID:22990760

Dorsal Arthroscopic Approach and Intra-Articular Anatomy of the Bovine Antebrachiocarpal and Middle Carpal Joints.

PubMed

Lardé, Hélène; Nichols, Sylvain; Babkine, Marie; Desrochers, André

2016-07-01

To determine arthroscopic approaches to the dorsal synovial compartments of the antebrachiocarpal and middle carpal joints in adult cattle, and to describe the arthroscopic intra-articular anatomy from each approach. Ex vivo study. Six fresh adult bovine cadavers. Two carpi were injected with latex and dissected to determine the ideal location for arthroscopic portals. Arthroscopy of the antebrachiocarpal and middle carpal joints of 10 carpi was then performed. The dorsolateral approach was made between the extensor carpi radialis and common digital extensor tendons. The dorsomedial approach was made medial to the extensor carpi radialis tendon, midway between the distal radius and proximal row of carpal bones (antebrachiocarpal joint) and midway between the two rows of carpal bones (middle carpal joint), with the joint in flexion. Arthroscopy of the antebrachiocarpal joint allowed visualization of the distal radius, proximal aspect of the radial, intermediate and ulnar carpal bones, and a palmar ligament located between the radius and the intermediate carpal bone. The approach to the middle carpal joint allowed visualization of the distal aspect of the radial, intermediate, and ulnar carpal bones, the proximal aspect of the fourth and fused second and third carpal bones and an interosseous ligament. The most lateral articular structures (lateral glenoid cavity of the distal radius, ulnar carpal and fourth carpal bones) were difficult to assess. Dorsal approaches to the antebrachiocarpal and middle carpal joints allowed visualization of most intra-articular dorsal structures in adult cattle. © Copyright 2016 by The American College of Veterinary Surgeons.

A new species of parasitic copepod Nothobomolochus and redescription of Orbitacolax hapalogenyos (Yamaguti and Yamasu, 1959) (Cyclopoida: Bomolochidae) off Iraq.

PubMed

Maran, Balu Alagar Venmathi; Moon, Seong Yong; Adday, Thamir K; Khamees, Najim R; Myoung, Jung-Goo

2014-10-01

A new species of bomolochid copepod Nothobomolochus ilhoikimi sp. n., (Cyclopoida), is described based on adult females collected from the gills of hilsa shad Tenualosa ilisha (Hamilton) (Actinopterygii, Clupeidae) captured in waters off Iraq. The new species differs from its congeners by having the following combination of characters in the adult female: 1) anal somite not spinulate; 2) paragnath blunt and robust; 3) maxilla with slender proximal segment and distal segment with 2 accessory processes terminally; 4) the distal exopodal segment of leg 1 with 3 small spines; and 5) the terminal endopodal segment of leg 4 carrying one long and one short spine. It closely resembles N. triceros (Bassett-Smith, 1898) but prominently differs in above features and also in host specificity. In addition, another bomolochid Orbitacolax hapalogenyos (Yamaguti and Yamasu, 1959) is redescribed based on material collected from Japanese threadfin bream Nemipterus japonicus (Bloch) (Perciformes, Nemipteridae) captured in waters off Iraq. Two species clusters, the hapalogenyos and the analogus groups are recognized in this genus.

The renal response to potassium stress: integrating past with present.

PubMed

Boyd-Shiwarski, Cary R; Subramanya, Arohan R

2017-09-01

The current review combines past findings with recent advances in our understanding of the homeostatic response to potassium imbalance. Following the ingestion of a dietary potassium load, a combination of extrarenal and renal mechanisms act to maintain extracellular K+ within a tight window. Through hormonal regulation and direct K+ sensing, the nephron is ideally suited to respond to wide shifts in external K+ balance. Current evidence indicates that dietary K+ loading triggers a coordinated kaliuretic response that appears to involve voltage-dependent changes in sodium transport across multiple nephron segments, including the proximal tubule, medullary loop of Henle, and distal tubule. Inhibition of sodium transport in these segments would accomplish the final goal of enhancing distal NaCl delivery, luminal flow, and K+ secretion in the aldosterone sensitive distal nephron (ASDN). Ongoing research seeks to define the relationship between potassium and volume homeostasis by elucidating pathways that couple renal K+ sensing and tubular function during the potassium stress response.

The effect of hyperbaric oxygen treatment on early regeneration of sensory axons after nerve crush in the rat.

PubMed

Bajrović, Fajko F; Sketelj, Janez; Jug, Marko; Gril, Iztok; Mekjavić, Igor B

2002-09-01

Abstract The effect of hyperbaric oxygen treatment (HBO) on sensory axon regeneration was examined in the rat. The sciatic nerve was crushed in both legs. In addition, the distal stump of the sural nerve on one side was made acellular and its blood perfusion was compromised by freezing and thawing. Two experimental groups received hyperbaric exposures (2.5 ATA) to either compressed air (pO2 = 0.5 ATA) or 100% oxygen (pO2 = 2.5 ATA) 90 minutes per day for 6 days. Sensory axon regeneration in the sural nerve was thereafter assessed by the nerve pinch test and immunohistochemical reaction to neurofilament. HBO treatment increased the distances reached by the fastest regenerating sensory axons by about 15% in the distal nerve segments with preserved and with compromised blood perfusion. There was no significant difference between the rats treated with different oxygen tensions. The total number of regenerated axons in the distal sural nerve segments after a simple crush injury was not affected, whereas in the nerve segments with compromised blood perfusion treated by the higher pO2, the axon number was about 30% lower than that in the control group. It is concluded that the beneficial effect of HBO on sensory axon regeneration is not dose-dependent between 0.5 and 2.5 ATA pO2. Although the exposure to 2.5 ATA of pO2 moderately enhanced early regeneration of the fastest sensory axons, it decreased the number of regenerating axons in the injured nerves with compromised blood perfusion of the distal nerve stump.

Effect of focused and radial extracorporeal shock wave therapy on equine bone microdamage.

PubMed

Da Costa Gómez, Támara M; Radtke, Catherine L; Kalscheur, Vicki L; Swain, Carol A; Scollay, Mary C; Edwards, Ryland B; Santschi, Elizabeth M; Markel, Mark D; Muir, Peter

2004-01-01

To determine whether bone microcracks are altered after application of focused and radial extracorporeal shock wave therapy (ESWT) to the equine distal limb. An ex vivo experimental model. A contralateral limb specimen was obtained from 11 Thoroughbred racehorses with a unilateral catastrophic injury. Distal limb specimens were also obtained from 5 non-racing horses. Three separate skin-covered bone segments were obtained from the mid-diaphysis of the metacarpus (MC3) or metatarsus (MT3). Focused (9,000 shockwaves, 0.15 mJ/mm2, 4 Hz) and radial (9,000 shockwaves, 0.175 mJ/mm2, 4 Hz) ESWT treatments were randomized to the proximal and distal segments and the middle segment was used as a treatment control for pre-existing microcracks. After treatment, bone specimens were bulk-stained with basic fuchsin and microcracks were quantified in transverse calcified bone sections. ESWT had small but significant effects on microcracks. Microcrack density (Cr.Dn) and microcrack surface density (Cr.S.Dn) were increased after focused ESWT, whereas Cr.Le was increased after radial ESWT. In racing Thoroughbreds, Cr.Le increased with increased number of races undertaken. Cr.Dn and Cr.S.Dn were not significantly influenced by the number of races undertaken. ESWT has small but significant effects on bone microcracking ex vivo. These preliminary data suggest that ESWT has the potential to increase bone microcracking in equine distal limb bone in vivo. Such effects may be more pronounced in Thoroughbreds that are actively being raced, because in vivo microcracking increases with increased number of races undertaken.

The effect of the heights and thicknesses of the remaining root segments on buccal bone resorption in the socket-shield technique: An experimental study in dogs.

PubMed

Tan, Zhen; Kang, Jian; Liu, Wenjia; Wang, Hang

2018-06-01

To date only a few studies have been done on the use of the socket-shield technique for preserving the resorption of the buccal bone in aesthetically sensitive sites. Besides, there have been no further studies on the effect of the heights and thicknesses of the remaining root segments on buccal bone resorption when using this method. The aim of this study was to evaluate the effect of different heights and thicknesses of the remaining root segments on bone resorption in the socket-shield technique. Four healthy female beagle dogs were used in this study. The third premolar (P3) and the fourth premolar (P4) on both sides of the mandible were hemisected in the buccal-lingual direction, and the clinical crown of the distal root was beheaded. In the experimental groups, the roots were worn down in the apical direction until they were located at the buccal crestal level (Group A) or 1 mm higher than that level (Group B). In the control group, the distal root segments were extracted. Then, implant placement was performed into the distal root. After 3 months of healing, the specimens were prepared for histological diagnosis. There was no difference between Group A and Group B when using the socket-shield technique, but the results of both groups were better than those of the control group. The height of the root segments has little effect on the bone absorption of alveolar bone, while the bone absorption was strongly influenced by the thickness of the root segments. More precisely, the absorption may decrease if the thickness of the root fragment increases, when the thickness of the root plate is in the 0.5-1.5 mm range. © 2018 Wiley Periodicals, Inc.

Primary nerve grafting: A study of revascularization.

PubMed

Chalfoun, Charbel; Scholz, Thomas; Cole, Matthew D; Steward, Earl; Vanderkam, Victoria; Evans, Gregory R D

2003-01-01

It was the purpose of this study to evaluate the revascularization of primary nerve repair and grafts using orthogonal polarization spectral (OPS) (Cytometrix, Inc.) imaging, a novel method for real-time evaluation of microcirculatory blood flow. Twenty male Sprague Dawley rats (250 g) were anesthetized with vaporized halothane and surgically prepared for common peroneal nerve resection. Group I animals (n = 10) underwent primary neurorraphy following transection, utilizing a microsurgical technique with 10-0 nylon suture. Group II (n = 10) animals had a 7-mm segment of nerve excised, reversed, and subsequently replaced as a nerve graft under similar techniques. All animals were evaluated using the OPS imaging system on three portions (proximal, transection site/graft, and distal) of the nerve following repair or grafting. Reevaluation of 5 animals randomly selected from each group using the OPS imaging system was again performed on days 14 and 28 following microsurgical repair/grafting. Values were determined by percent change in vascularity of the common peroneal nerve at 0 hr following surgery. Real-time evaluation of blood flow was utilized as an additional objective criterion. Percent vascularity in group I and II animals increased from baseline in all segments at day 14. By day 28, vascularity in nerves of group I rats decreased in all segments to values below baseline, with the exception of the transection site, which remained at a higher value than obtained directly after surgical repair. In group II animals, vascularity remained above baseline in all segments except the distal segment, which returned to vascularity levels similar to those at 0 hr. Further, occlusion of the vessels demonstrated in the graft and distal segments following initial transection appeared to be corrected. This study suggests that revascularization may occur via bidirectional inosculation with favored proximal vascular growth advancement. The use of real-time imaging offers a unique evaluation of tissues through emerging technologies. Copyright 2003 Wiley-Liss, Inc.

Site-specific association between distal aortic pulse wave velocity and peripheral arterial stenosis severity: a prospective cardiovascular magnetic resonance study.

PubMed

van den Bosch, Harrie C M; Westenberg, Jos J M; Setz-Pels, Wikke; Wondergem, John; Wolterbeek, Ron; Duijm, Lucien E M; Teijink, Joep A W; de Roos, Albert

2015-01-20

Vascular disease expression in one location may not be representative for disease severity in other vascular territories, however, strong correlation between disease expression and severity within the same vascular segment may be expected. Therefore, we hypothesized that aortic stiffening is more strongly associated with disease expression in a vascular territory directly linked to that aortic segment rather than in a more remote segment. We prospectively compared the association between aortic wall stiffness, expressed by pulse wave velocity (PWV), sampled in the distal aorta, with the severity of peripheral arterial occlusive disease (PAOD) as compared to atherosclerotic markers sampled in remote vascular territories such as PWV in the proximal aorta and the normalized wall index (NWI), representing the vessel wall thickness, of the left common carotid artery. Forty-two patients (23 men; mean age 64±10 years) underwent velocity-encoded cardiovascular magnetic resonance (CMR) in the proximal and distal aorta, whole-body contrast-enhanced MR angiography (CE-MRA) and carotid vessel wall imaging with black-blood CMR in the work-up for PAOD. Strength of associations between aortic stiffness, carotid NWI and peripheral vascular stenosis grade were assessed and evaluated with multiple linear regression. Stenosis severity correlated well with PWV in the distal aorta (Pearson rP=0.64, p<0.001, Spearman rS=0.65, p<0.001) but to a lesser extent with PWV in the proximal aorta (rP=0.48, p=0.002, rS=0.22, p=0.18). Carotid NWI was not associated with peripheral stenosis severity (rP=0.17, p=0.28, rS=0.14, p=0.37) nor with PWV in the proximal aorta (rP=0.22, p=0.17) nor in the distal aorta (rP=0.21, p=0.18). Correlation between stenosis severity and distal aortic PWV remained statistically significant after correction for age and gender. Distal aortic wall stiffness is more directly related to peripheral arterial stenosis severity than markers from more remote vascular territories such as proximal aortic wall stiffness or carotid arterial wall thickness. Site-specific evaluation of vascular disease may be required for full vascular risk estimation.

Description of Alloretochus sigillatus new species with comments and new distributional records for Alloretochus peruanicus (Ephemeroptera, Caenidae, Brachycercinae).

PubMed

Molineri, C

2014-06-19

Alloretochus sigillatus sp. nov. is described from adults of both sexes and eggs from Bolivia and Ecuador. Diagnostic characters of this species include: large body size, ratio pedicel/scape 1.75, presence of posteromedian projection on metanotum, characteristic blackish marks on abdominal terga, presence of vestiges of posterolateral projections on abdomen segments IV-VI, male subgenital plate broadly emarginated posteriorly, ratios forceps length/subbasal width 8.9, female sternum IX produced distally reaching apex of segment X, tapering distally with rounded apex, egg with 4 costae in lateral half. Additional characters for all stages and SEM photographs of eggs are provided for Alloretochus peruanicus, with new records of its presence in Argentina, Bolivia, Peru and Colombia.

Rapid protein disappearance rates along the small intestine advantage poultry performance and influence the post-enteral availability of amino acids.

PubMed

Truong, Ha H; Chrystal, Peter V; Moss, Amy F; Selle, Peter H; Liu, Sonia Yun

2017-12-01

A foundation diet, an intermediate blend and a summit diet were formulated with different levels of soyabean meal, casein and crystalline amino acids to compare 'slow' and 'rapid' protein diets. The diets were offered to male Ross 308 chicks from 7 to 28 d post-hatch and assessed parameters included growth performance, nutrient utilisation, apparent digestibility coefficients and disappearance rates of starch and protein (N) in four small intestinal segments. Digestibility coefficients and disappearance rates of sixteen amino acids in three small intestinal segments and amino acid concentrations in plasma from portal and systemic circulations from the foundation and summit diets were determined. The dietary transition significantly accelerated protein (N) disappearance rates in the distal jejunum and ileum. The transition from foundation to summit diets significantly increased starch digestibility coefficients in the ileum and disappearance rates in all four small intestinal segments. These starch responses were associated with significant enhancements in nutrient utilisation. The dietary transition linearly increased digestibility coefficients and disappearance rates of amino acids in the majority of cases. The summit diet increased plasma concentrations of five amino acids but decreased those of four amino acids relative to the foundation diet to significant extents. Plasma concentrations of free amino acids were higher in the portal than systemic circulations. Rapid protein disappearance rates advantaged poultry performance and influenced post-enteral availability of amino acids. If the underlying mechanisms are to be identified, further research into the impact of protein digestive dynamics on broiler performance is required but appears justified.

Efficacy and safety of catheter-based radiofrequency renal denervation in stented renal arteries.

PubMed

Mahfoud, Felix; Tunev, Stefan; Ruwart, Jennifer; Schulz-Jander, Daniel; Cremers, Bodo; Linz, Dominik; Zeller, Thomas; Bhatt, Deepak L; Rocha-Singh, Krishna; Böhm, Michael; Melder, Robert J

2014-12-01

In selected patients with hypertension, renal artery (RA) stenting is used to treat significant atherosclerotic stenoses. However, blood pressure often remains uncontrolled after the procedure. Although catheter-based renal denervation (RDN) can reduce blood pressure in certain patients with resistant hypertension, there are no data on the feasibility and safety of RDN in stented RA. We report marked blood pressure reduction after RDN in a patient with resistant hypertension who underwent previous stenting. Subsequently, radiofrequency ablation was investigated within the stented segment of porcine RA, distal to the stented segment, and in nonstented RA and compared with stent only and untreated controls. There were neither observations of thrombus nor gross or histological changes in the kidneys. After radiofrequency ablation of the nonstented RA, sympathetic nerves innervating the kidney were significantly reduced, as indicated by significant decreases in sympathetic terminal axons and reduction of norepinephrine in renal tissue. Similar denervation efficacy was found when RDN was performed distal to a renal stent. In contrast, when radiofrequency ablation was performed within the stented segment of the RA, significant sympathetic nerve ablation was not seen. Histological observation showed favorable healing in all arteries. Radiofrequency ablation of previously stented RA demonstrated that RDN provides equally safe experimental procedural outcomes in a porcine model whether the radiofrequency treatment is delivered within, adjacent, or without the stent struts being present in the RA. However, efficacious RDN is only achieved when radiofrequency ablation is delivered to the nonstented RA segment distal to the stent. © 2014 American Heart Association, Inc.

Distal regulatory regions restrict the expression of cis-linked genes to the tapetal cells.

PubMed

Franco, Luciana O; de O Manes, Carmem Lara; Hamdi, Said; Sachetto-Martins, Gilberto; de Oliveira, Dulce E

2002-04-24

The oleosin glycine-rich protein genes Atgrp-6, Atgrp-7, and Atgrp-8 occur in clusters in the Arabidopsis genome and are expressed specifically in the tapetum cells. The cis-regulatory regions involved in the tissue-specific gene expression were investigated by fusing different segments of the gene cluster to the uidA reporter gene. Common distal regulatory regions were identified that coordinate expression of the sequential genes. At least two of these genes were regulated spatially by proximal and distal sequences. The cis-acting elements (122 bp upstream of the transcriptional start point) drive the uidA expression to floral tissues, whereas distal 5' upstream regions restrict the gene activity to tapetal cells.

Development of the zebrafish mesonephros

PubMed Central

Diep, Cuong Q.; Peng, Zhenzhen; Ukah, Tobechukwu K.; Kelly, Paul M.; Daigle, Renee V.; Davidson, Alan J.

2015-01-01

The vertebrate kidney plays an essential role in removing metabolic waste and balancing water and salt. This is carried out by nephrons, which comprise a blood filter attached to an epithelial tubule with proximal and distal segments. In zebrafish, two nephrons are first formed as part of the embryonic kidney (pronephros) and hundreds are formed later to make up the adult kidney (mesonephros). Previous studies have focused on the development of the pronephros while considerably less is known about how the mesonephros is formed. Here, we characterize mesonephros development in zebrafish and examine the nephrons that form during larval metamorphosis. These nephrons, arising from proliferating progenitor cells that express the renal transcription factor genes wt1b, pax2a, and lhx1a, form on top of the pronephric tubules and develop a segmentation pattern similar to pronephric nephrons. We find that the pronephros acts as a scaffold for the mesonephros, where new nephrons fuse with the distal segments of the pronephric tubules to form the final branching network that characterizes the adult zebrafish kidney. PMID:25677367

Midterm Clinical Outcomes after Modified High Ligation and Segmental Stripping of Incompetent Small Saphenous Veins

PubMed Central

Hong, Ki Pyo

2015-01-01

Background The aim of this study was to evaluate the midterm clinical outcomes after modified high ligation and segmental stripping of small saphenous vein (SSV) varicosities. Methods Between January 2010 and March 2013, 62 patients (69 legs) with isolated primary small saphenous varicose veins were enrolled in this study. The outcomes measured were reflux in the remaining distal SSV, the recurrence of varicose veins, the improvement of preoperative symptoms, and the rate of postoperative complications. Results No major complications occurred. No instances of the recurrence of varicose veins at previous stripping sites were noted. Three legs (4.3%) showed reflux in the remaining distal small saphenous veins. The preoperative symptoms were found to have improved in 96.4% of the cases. Conclusion In the absence of flush ligation of the saphenopopliteal junction, modified high ligation and segmental stripping of small saphenous vein varicosities with preoperative duplex marking is an effective treatment method for reducing postoperative complications and the recurrence of SSV incompetence. PMID:26665106

Relevance of Occlusion Test in Endovascular Coiling of Posterior Cerebral Artery (P2 Segment) Aneurysms

PubMed Central

Jayakumar, P. N.; Desai, S.; Srikanth, S. G.; Ravishankar, S.; Kovoor, J. M. E.

2004-01-01

Summary P2 segment aneurysms are located on the posterior cerebral artery (PCA) between the junction of the posterior communicating artery with the PCA and the quadrigeminal cisternal part of the PCA. We reviewed our experience with endovascular coiling in such aneurysms. Clinical and pre-procedural data from four patients, referred for endovascular treatment of P2 segment aneurysms, were retrospectively studied for factors influencing post-interventional neurological deficits caused by ischemia of the PCA distal territory. Balloon occlusion was done in three patients and patient tolerance was assessed using clinical and anatomic criteria. Embryologic and anatomic features of the PCA were reviewed. Balloon occlusion test and endovascular coiling of aneurysms was possible in three patients. Control angiogram after embolization showed elimination of aneurysms from the circulation and the distal PCA filled through leptomeningeal anastomoses. One patient deteriorated due to aneurysmal rupture soon after the balloon occlusion test and coiling could not be done. In the other three patients post-intervention CT and MRI images showed PCA territory infarcts in spite of demonstration of good collateral circulation distal to the occluded PCA. In conclusion, P2 aneurysms can be effectively treated by endovascular coiling without a balloon occlusion test. While the balloon occlusion test does not contribute to clinical decision-making it may be associated with potential morbidity and mortality. PMID:20587236

DYF-1 Is Required for Assembly of the Axoneme in Tetrahymena thermophila▿ †

PubMed Central

Dave, Drashti; Wloga, Dorota; Sharma, Neeraj; Gaertig, Jacek

2009-01-01

In most cilia, the axoneme can be subdivided into three segments: proximal (the transition zone), middle (with outer doublet microtubules), and distal (with singlet extensions of outer doublet microtubules). How the functionally distinct segments of the axoneme are assembled and maintained is not well understood. DYF-1 is a highly conserved ciliary protein containing tetratricopeptide repeats. In Caenorhabditis elegans, DYF-1 is specifically needed for assembly of the distal segment (G. Ou, O. E. Blacque, J. J. Snow, M. R. Leroux, and J. M. Scholey. Nature. 436:583-587, 2005). We show that Tetrahymena cells lacking an ortholog of DYF-1, Dyf1p, can assemble only extremely short axoneme remnants that have structural defects of diverse natures, including the absence of central pair and outer doublet microtubules and incomplete or absent B tubules on the outer microtubules. Thus, in Tetrahymena, DYF-1 is needed for either assembly or stability of the entire axoneme. Our observations support the conserved function for DYF-1 in axoneme assembly or stability but also show that the consequences of loss of DYF-1 for axoneme segments are organism specific. PMID:19581442

Reproduction in the male honey possum (Tarsipes rostratus: Marsupialia): the epididymis.

PubMed

Cummins, J M; Temple-Smith, P D; Renfree, M B

1986-11-01

The epididymis of the adult honey possum, Tarsipes rostratus, is enclosed by a heavily pigmented tunica vaginalis and lies with the testis in a prominent prepenile scrotum. It is connected to the testis by a single ductus efferentis and is lined by approximately equal numbers of cuboidal ciliated and principal cells. It is unusual for marsupials in having no well-defined compartments or fibrous septae and in having extensive convolutions of the duct only at the caudal flexure. Three principal functional zones (initial, middle, and terminal segments) were identified in the epididymis, based on epithelial type and ultrastructural evidence of sperm maturation. Luminal diameter increases progressively throughout the tract, and epithelial height variations (from about 2 to 20 microns) are greatest in the terminal segment. The epithelium itself is remarkably low (maximum of 21.6 microns) compared with that seen in the epididymis of other mammals. The thickness of the peritubular smooth muscle coat increases close to the junction of the epididymis and ductus deferens. Sperm concentrations were estimated from counts of sperm nuclei and thus can be no more than approximations. The figures are consistent, however, with a rapid increase in concentration in the initial segment, indicating extensive fluid resorption. Sperm concentrations appear to peak in the distal zone of the terminal segment, although sampling problems and wide variations in count make such a conclusion only tentative. Principal and basal cells are the predominant cell types in the epididymal epithelium. Basal cells are most abundant in the initial and distal middle segment. Principal cells show structural evidence of active exchange with the luminal contents and have abundant apical stereocilia, the structure of which depends on the epididymal zone. Other cell types occur less commonly in the epithelium. Lipid-rich and phagocytic principal cells are restricted to the middle and distal zones of the middle segment, respectively. Clear cells, restricted to the terminal segment, and halo cells were found in very low numbers. As in some other marsupials, principal cells (possibly specialized for this function) selectively remove cytoplasmic droplets and probably other cellular debris from the luminal contents. In Tarsipes, however, this process is not very efficient, and many discarded droplets pass through to the terminal segment where they form large masses of debris associated with aggregates of degenerating spermatozoa.

Segmented trapped vortex cavity

NASA Technical Reports Server (NTRS)

Grammel, Jr., Leonard Paul (Inventor); Pennekamp, David Lance (Inventor); Winslow, Jr., Ralph Henry (Inventor)

2010-01-01

An annular trapped vortex cavity assembly segment comprising includes a cavity forward wall, a cavity aft wall, and a cavity radially outer wall there between defining a cavity segment therein. A cavity opening extends between the forward and aft walls at a radially inner end of the assembly segment. Radially spaced apart pluralities of air injection first and second holes extend through the forward and aft walls respectively. The segment may include first and second expansion joint features at distal first and second ends respectively of the segment. The segment may include a forward subcomponent including the cavity forward wall attached to an aft subcomponent including the cavity aft wall. The forward and aft subcomponents include forward and aft portions of the cavity radially outer wall respectively. A ring of the segments may be circumferentially disposed about an axis to form an annular segmented vortex cavity assembly.

BDNF gene delivery within and beyond templated agarose multi-channel guidance scaffolds enhances peripheral nerve regeneration

NASA Astrophysics Data System (ADS)

Gao, Mingyong; Lu, Paul; Lynam, Dan; Bednark, Bridget; Campana, W. Marie; Sakamoto, Jeff; Tuszynski, Mark

2016-12-01

Objective. We combined implantation of multi-channel templated agarose scaffolds with growth factor gene delivery to examine whether this combinatorial treatment can enhance peripheral axonal regeneration through long sciatic nerve gaps. Approach. 15 mm long scaffolds were templated into highly organized, strictly linear channels, mimicking the linear organization of natural nerves into fascicles of related function. Scaffolds were filled with syngeneic bone marrow stromal cells (MSCs) secreting the growth factor brain derived neurotrophic factor (BDNF), and lentiviral vectors expressing BDNF were injected into the sciatic nerve segment distal to the scaffold implantation site. Main results. Twelve weeks after injury, scaffolds supported highly linear regeneration of host axons across the 15 mm lesion gap. The incorporation of BDNF-secreting cells into scaffolds significantly increased axonal regeneration, and additional injection of viral vectors expressing BDNF into the distal segment of the transected nerve significantly enhanced axonal regeneration beyond the lesion. Significance. Combinatorial treatment with multichannel bioengineered scaffolds and distal growth factor delivery significantly improves peripheral nerve repair, rivaling the gold standard of autografts.

A new intermediate for the production of flexible stable polymers

NASA Technical Reports Server (NTRS)

Webster, J. A.

1973-01-01

Method of incorporating ether linkages into perfluoroalkylene segment of a dianydride intermediate yields intermediate that may be used in synthesis of flexible, stable polyimides for use as high-temperature, solvent-resistant sealants.

Optimization of Soft Tissue Management, Spacer Design, and Grafting Strategies for Large Segmental Bone Defects using the Chronic Caprine Tibial Defect Model

DTIC Science & Technology

2015-10-01

Several target genes such as Oct4, Sox2, TGFB, and Col1A1 were generally up-regulated in all sections. In distal sections, VWF, PDGFB, and EGFR were...TGFB, and Col1A1 in all sections. No significant main effects were found for target gene fold-change between outer or inner membrane position or distal

Distal radius fractures result in alterations in scapular kinematics: a three-dimensional motion analysis.

PubMed

Ayhan, Cigdem; Turgut, Elif; Baltaci, Gul

2015-03-01

Scapular motion is closely integrated with arm motion. Injury to a distal segment requires compensatory changes in the proximal segments leading to alterations in scapular motion. Since the effects of distal injuries on scapular kinematics remain unknown, in the present study we investigated the influences on scapular motion in patients with distal injuries. Sixteen subjects with a history of distal radius fracture and 20 asymptomatic healthy subjects (controls) participated in the study. Three-dimensional scapular and humeral kinematic data were collected on all 3 planes of shoulder elevation: frontal, sagittal, and scapular. All testing was performed in a single session; therefore, the sensors remained attached to the participants for all testing. The position and orientation data of the scapula at 30°, 60°, 90°, and 120° humerothoracic elevation and 120°, 90°, 60°, and 30° lowering were used for statistical comparisons. Independent samples t-test was used to compare the scapular internal/external rotation, upward/downward rotation, and anterior/posterior tilt between the affected side of subjects with a distal radius fracture and the dominant side of asymptomatic subjects at the same stage of humerothoracic elevation. Scapular internal rotation was significantly increased at 30° elevation (P=0.01), 90° elevation (P=0.03), and 30° lowering (P=0.03), and upward rotation was increased at 30° and 60° elevation (P<0.001) on the affected side during frontal plane elevation. Scapular upward rotation and anterior tilt were significantly increased during 30° lowering on both the scapular (P=0.002 and 0.02, respectively) and sagittal planes (P=0.01 and 0.02. respectively). Patients with distal radius fractures exhibit altered scapular kinematics, which may further contribute to the development of secondary musculoskeletal pathologies. Copyright © 2014 Elsevier Ltd. All rights reserved.

Numerical investigation and identification of susceptible sites of atherosclerotic lesion formation in a complete coronary artery bypass model.

PubMed

Zhang, Jun-Mei; Chua, Leok Poh; Ghista, Dhanjoo N; Yu, Simon Ching Man; Tan, Yong Seng

2008-07-01

As hemodynamics is widely believed to correlate with anastomotic stenosis in coronary bypass surgery, this paper investigates the flow characteristics and distributions of the hemodynamic parameters (HPs) in a coronary bypass model (which includes both proximal and distal anastomoses), under physiological flow conditions. Disturbed flows (flow separation/reattachment, vertical and secondary flows) as well as regions of high oscillatory shear index (OSI) with low wall shear stress (WSS), i.e., high-OSI-and-low-WSS and low-OSI-and-high-WSS were found in the proximal and distal anastomoses, especially at the toe and heel regions of distal anastomosis, which indicate highly suspected sites for the onset of the atherosclerotic lesions. The flow patterns found in the graft and distal anastomoses of our model at deceleration phases are different from those of the isolated distal anastomosis model. In addition, a huge significant difference in segmental averages of HPs was found between the distal and proximal anastomoses. These findings further suggest that intimal hyperplasia would be more prone to form in the distal anastomosis than in the proximal anastomosis, particularly along the suture line at the toe and heel of distal anastomosis.

Two new mountainous species of Lactuca (Cichorieae, Asteraceae) from Iran, one presenting a new, possibly myrmecochorous achene variant.

PubMed

Kilian, Norbert; Djavadi, Seyyedeh Bahereh; Eskandari, Majid

2012-01-01

It is shown that the concept of the Iranian endemic Lactuca polyclada in the sense of both its original author Boissier and its current use actually admixes two entirely different species, as was first noted by Beauverd a hundred years ago but has been neglected by later workers. One is a putative relative of Lactuca rosularis, the other was recognised by Beauverd as a member of the genus Cicerbita. The name Lactuca polyclada Boiss. is lectotypified here, maintaining its use as established by Beauverd for the Cicerbita species. Both species are morphologically delimited and mature achenes of Cicerbita polyclada are illustrated for the first time. The putative relative of Lactuca rosularis, a rare local endemic of the summit area of Kuh e-Dena, which has remained without a valid name by now, is described as a new species, Lactuca denaensis N. Kilian & Djavadi, and illustrated. A third member of the Lactuca rosularis group, Lactuca hazaranensis Djavadi & N. Kilian, discovered among a recent collection and apparently being a rare chasmophyte of the Hazaran mountain massif in the province of Kerman, Iran, is described as a species new to science, illustrated and delimited from the other two species. This new species has peculiar achenes representing a hitherto unknown variant: the body of the beaked achenes is divided into two segments by a transversal constriction in the distal third. The proximal segment contains the embryo, the distal segment is solid with a lipid-containing yellow tissue. The easily detachable pappus and the equally easily detachable beak potentially obstruct dispersal by wind. Since detachment of the beak also exposes the lipid-containing tissue of the distal segment, its potential as an elaiosome and myrmecochory as a possible mode of dispersal are discussed.

Two new mountainous species of Lactuca (Cichorieae, Asteraceae) from Iran, one presenting a new, possibly myrmecochorous achene variant

PubMed Central

Kilian, Norbert; Djavadi, Seyyedeh Bahereh; Eskandari, Majid

2012-01-01

Abstract It is shown that the concept of the Iranian endemic Lactuca polyclada in the sense of both its original author Boissier and its current use actually admixes two entirely different species, as was first noted by Beauverd a hundred years ago but has been neglected by later workers. One is a putative relative of Lactuca rosularis, the other was recognised by Beauverd as a member of the genus Cicerbita. The name Lactuca polyclada Boiss. is lectotypified here, maintaining its use as established by Beauverd for the Cicerbita species. Both species are morphologically delimited and mature achenes of Cicerbita polyclada are illustrated for the first time. The putative relative of Lactuca rosularis, a rare local endemic of the summit area of Kuh e-Dena, which has remained without a valid name by now, is described as a new species, Lactuca denaensis N. Kilian & Djavadi, and illustrated. A third member of the Lactuca rosularis group, Lactuca hazaranensis Djavadi & N. Kilian, discovered among a recent collection and apparently being a rare chasmophyte of the Hazaran mountain massif in the province of Kerman, Iran, is described as a species new to science, illustrated and delimited from the other two species. This new species has peculiar achenes representing a hitherto unknown variant: the body of the beaked achenes is divided into two segments by a transversal constriction in the distal third. The proximal segment contains the embryo, the distal segment is solid with a lipid-containing yellow tissue. The easily detachable pappus and the equally easily detachable beak potentially obstruct dispersal by wind. Since detachment of the beak also exposes the lipid-containing tissue of the distal segment, its potential as an elaiosome and myrmecochory as a possible mode of dispersal are discussed. PMID:22577334

Separation between the digestive and the respiratory lumina during the human embryonic period: morphometric study along the tracheo-oesophageal septum

PubMed Central

NEBOT-CEGARRA, JOSEP; FÀBREGAS, PERE J.; CAMPILLO, MERCEDES; RICART, SILVIA

2001-01-01

An isolated tracheo-oesophageal fistula could be caused by close proximity of the epithelia of both organs (O'Rahilly & Müller, 1984; Kluth et al. 1987) at certain embryonic stages, the most frequent location being the tracheal bifurcation. Thus the relative position and degree of separation between the digestive and the respiratory tubes throughout their development may be relevant to the origin of this anomaly. The aim of this study was to analyse along the different segments of the tracheo-oesophageal septum (TES) where the closest relationship between both lumina occurred and what degree of separation was present at each segment. Computer imaging techniques were applied on cross sections of a graded series of normal human embryos (Carnegie stages (CS) 13–23). In addition, the differentiation of the primitive TES was also studied (from CS 12) by light microscopy. Between CS 13 and 16 both tubes tended to separate (phase of separation), principally at the proximal segments of the laryngopharyngeal and the tracheo-oesophageal portions of the TES. During this phase the separation between the trachea and oesophagus was wider than between the larynx and pharynx. From CS 17 to CS 23 the digestive and respiratory lumina reached their widest separation at different levels of the laryngopharyngeal portion. Below these levels they tended to come closer together, principally at the proximal segment of the tracheo-oesophageal portion, but also at the distal part of the laryngopharyngeal portion. During this phase of approximation they reached their closest relationship at the proximal (CS 17) and the distal (from CS 18) segments of the tracheo-oesophageal portion. When finally the distal segment of the trachea (which includes the bifurcation) comes closest to the oesophagus, the coats of both organs have already undergone an appreciable differentiation. According to these observations, the origin of the most frequent isolated tracheo-oesophageal fistula at the bifurcation region could not be explained from the normal development of the TES. PMID:11215762

Gene expression in spider appendages reveals reversal of exd/hth spatial specificity, altered leg gap gene dynamics, and suggests divergent distal morphogen signaling.

PubMed

Prpic, Nikola-Michael; Janssen, Ralf; Wigand, Barbara; Klingler, Martin; Damen, Wim G M

2003-12-01

Leg development in Drosophila has been studied in much detail. However, Drosophila limbs form in the larva as imaginal discs and not during embryogenesis as in most other arthropods. Here, we analyze appendage genes in the spider Cupiennius salei and the beetle Tribolium castaneum. Differences in decapentaplegic (dpp) expression suggest a different mode of distal morphogen signaling suitable for the specific geometry of growing limb buds. Also, expression of the proximal genes homothorax (hth) and extradenticle (exd) is significantly altered: in the spider, exd is restricted to the proximal leg and hth expression extends distally, while in insects, exd is expressed in the entire leg and hth is restricted to proximal parts. This reversal of spatial specificity demonstrates an evolutionary shift, which is nevertheless compatible with a conserved role of this gene pair as instructor of proximal fate. Different expression dynamics of dachshund and Distal-less point to modifications in the regulation of the leg gap gene system. We comment on the significance of this finding for attempts to homologize leg segments in different arthropod classes. Comparison of the expression profiles of H15 and optomotor-blind to the Drosophila patterns suggests modifications also in the dorsal-ventral patterning system of the legs. Together, our results suggest alterations in many components of the leg developmental system, namely proximal-distal and dorsal-ventral patterning, and leg segmentation. Thus, the leg developmental system exhibits a propensity to evolutionary change, which probably forms the basis for the impressive diversity of arthropod leg morphologies.

Cardinal ligament surgical anatomy: cardinal points at hysterectomy.

PubMed

Samaan, Andrew; Vu, Dzung; Haylen, Bernard T; Tse, Kelly

2014-02-01

The cardinal ligament (CL) still requires more precise anatomical mapping. We aim to elucidate the anatomy of the CL and the roles it plays in gynecological surgery. Studies employed sharp dissection of 28 formalin-fixed cadaveric hemipelves and 10 unembalmed cadaveric hemipelves. The CL (total length averaging 10.0 cm) can be subdivided into three sections: a distal (cervical) section, on average 2.1 cm long, attached to the lateral aspect of the cervix (posteriorly, it was confluent with the attachment of the uterosacral [USL] ligament to form the cardinal-uterosacral confluence [CUSC]); an intermediate section, on average 3.4 cm long, running laterally (slightly posteriorly) from the cervix; a proximal (pelvic) section, relatively thick, triangular-shaped on cross-section, averaging 4.6 cm long, attached to the lateral pelvic sidewall, with its apex at the first branching of the internal iliac artery. Only the distal section is free of any significant neural or vascular component (ureter is in the intermediate section) and therefore safe for surgical use. The CUSC (first pedicle of a vaginal hysterectomy and later pedicle of an abdominal hysterectomy), if attached to the vaginal vault at hysterectomy has the potential for both lateral (CL) and supero-posterior (USL) surgical support. This pedicle would not be subsequently accessible for other surgeries. Suggested cardinal points at hysterectomy are: know the CL anatomy; the distal section (as part of the CUSC) can provide vaginal vault support; the intermediate and proximal sections are surgically dangerous.

Pseudocyclops schminkei (Copepoda, Calanoida, Pseudocyclopidae): a new species from Okinawa

NASA Astrophysics Data System (ADS)

Chullasorn, Supawadee; Ferrari, Frank D.; Dahms, Hans-Uwe

2010-03-01

Both genders of Pseudocyclops schminkei n. sp. are described from a pearl fishery aquarium on Zamami Island, Okinawa, Japan; it is the 37th species of the genus. Pseudocyclops schminkei sp. nov. differs from other species of the magnus species group in the shape of the lobes of distal exopodal segment of the male left leg 5, and the morphology of setae on middle and distal exopodal segment of male right swimming leg 2. Aspects of the morphology of P. xiphophorus and P. bilobatus are redescribed, and an unnamed Pseudocyclops sp. from the Shedd Aquarium in Chicago, IL, is briefly noted. Females of P. schminkei sp. nov., P. xiphophorus and Pseudocyclops sp. could not be separated from each other with the small number of specimens available in this study for the former two species.

Changes in cholinergic and nitrergic systems of defunctionalized colons after colostomy in rabbits.

PubMed

Moralıoğlu, Serdar; Vural, İsmail Mert; Özen, İbrahim Onur; Öztürk, Gökçe; Sarıoğlu, Yusuf; Başaklar, Abdullah Can

2017-01-01

This study was designed to assess smooth muscle function and motility in defunctionalized colonic segments and subsequent changes in pathways responsible for gastrointestinal motility. Two-month-old New Zealand rabbits were randomly allocated into control and study groups. Sigmoid colostomies were performed in the study group. After a 2-month waiting period, colonic segments were harvested in both groups. For the in vitro experiment, the isolated circular muscle strips which were prepared from the harvested distal colon were used. First, contraction responses were detected using KCl and carbachol; relaxation responses were detected using papaverine, sodium nitroprusside, sildenafil, and l-arginine. The neurologic responses of muscle strips to electrical field stimulation (EFS) were evaluated in an environment with guanethidine and indomethacin. EFS studies were then repeated with atropine, Nω-nitro-l-arginine methyl ester, atropine, and Nω-nitro-l-arginine methyl ester-added environments. Although macroscopic atrophy had developed in the distal colonic segment of the colostomy, the contraction and relaxation capacity of the smooth muscle did not change. EFS-induced nitrergic-peptidergic, cholinergic-peptidergic, and noncholinergic nonnitrergic responses significantly decreased at all frequencies (0.5-32 Hz) in the study group compared with those in the control group (P < 0.05). Although the contraction capacity of the smooth muscle was not affected, the motility of the distal colon deteriorated owing to the defective secretion of presynaptic neurotransmitters such as acetylcholine, nitric oxide, and neuropeptides. Copyright © 2016 Elsevier Inc. All rights reserved.

Fractures of the distal tibia treated with polyaxial locking plating.

PubMed

Gao, Hong; Zhang, Chang-Qing; Luo, Cong-Feng; Zhou, Zu-Bin; Zeng, Bing-Fang

2009-03-01

We evaluated the healing rate, complications, and functional outcomes in 32 adult patients with very short metaphyseal fragments in fractures of the distal tibia treated with a polyaxial locking system. The average distance from the distal extent of the fracture to the tibial plafond was 11 mm. All fractures healed and the average time to union was 14 weeks. Six patients (19%) reported occasional local disturbance over the medial malleolus. There were two cases of postoperative superficial infections and evidence of delayed wound healing. Using the American Orthopaedic Foot and Ankle Society ankle score, the average functional score was 87.3 points (of 100 total possible points). Our results show the polyaxial locking plates, which offer more fixation versatility, may be a reasonable treatment option for distal tibia fractures with very short metaphyseal segments.

Development of the zebrafish mesonephros.

PubMed

Diep, Cuong Q; Peng, Zhenzhen; Ukah, Tobechukwu K; Kelly, Paul M; Daigle, Renee V; Davidson, Alan J

2015-01-01

The vertebrate kidney plays an essential role in removing metabolic waste and balancing water and salt. This is carried out by nephrons, which comprise a blood filter attached to an epithelial tubule with proximal and distal segments. In zebrafish, two nephrons are first formed as part of the embryonic kidney (pronephros) and hundreds are formed later to make up the adult kidney (mesonephros). Previous studies have focused on the development of the pronephros while considerably less is known about how the mesonephros is formed. Here, we characterize mesonephros development in zebrafish and examine the nephrons that form during larval metamorphosis. These nephrons, arising from proliferating progenitor cells that express the renal transcription factor genes wt1b, pax2a, and lhx1a, form on top of the pronephric tubules and develop a segmentation pattern similar to pronephric nephrons. We find that the pronephros acts as a scaffold for the mesonephros, where new nephrons fuse with the distal segments of the pronephric tubules to form the final branching network that characterizes the adult zebrafish kidney. © 2015 Wiley Periodicals, Inc.

Anterior lumbar instrumentation improves correction of severe lumbar Lenke C curves in double major idiopathic scoliosis

PubMed Central

Yeon, Howard B.; Weinberg, Jacob; Arlet, Vincent; Ouelett, Jean A.

2007-01-01

Fifteen skeletally immature patients with double major adolescent idiopathic scoliosis with large lumbar curves and notable L4 and L5 coronal plane obliquity were retrospectively studied. Seven patients who underwent anterior release and fusion of the lumbar curve with segmental anterior instrumentation and subsequent posterior instrumentation ending at L3 were compared with eight patients treated with anterior release and fusion without anterior instrumentation followed by posterior instrumentation to L3 or L4. At 4.5 years follow-up (range 2.5–7 years), curve correction, coronal balance and fusion rate were not statistically different between the two groups; however, the group with anterior instrumentation had improved coronal plane, near normalangulation in the distal unfused segment compared with the group without anterior instrumentation. In cases involving severe lumbar curvatures in the context of double major scoliosis, when as a first stage anterior release is chosen, the addition of instrumentation appears to restore normal coronal alignment of the distal unfused lumbar segment, and may in certain cases save a level compared with traditional fusions to L4. PMID:17464517

Scale effects and morphological diversification in hindlimb segment mass proportions in neognath birds.

PubMed

Kilbourne, Brandon M

2014-01-01

In spite of considerable work on the linear proportions of limbs in amniotes, it remains unknown whether differences in scale effects between proximal and distal limb segments has the potential to influence locomotor costs in amniote lineages and how changes in the mass proportions of limbs have factored into amniote diversification. To broaden our understanding of how the mass proportions of limbs vary within amniote lineages, I collected data on hindlimb segment masses - thigh, shank, pes, tarsometatarsal segment, and digits - from 38 species of neognath birds, one of the most speciose amniote clades. I scaled each of these traits against measures of body size (body mass) and hindlimb size (hindlimb length) to test for departures from isometry. Additionally, I applied two parameters of trait evolution (Pagel's λ and δ) to understand patterns of diversification in hindlimb segment mass in neognaths. All segment masses are positively allometric with body mass. Segment masses are isometric with hindlimb length. When examining scale effects in the neognath subclade Land Birds, segment masses were again positively allometric with body mass; however, shank, pedal, and tarsometatarsal segment masses were also positively allometric with hindlimb length. Methods of branch length scaling to detect phylogenetic signal (i.e., Pagel's λ) and increasing or decreasing rates of trait change over time (i.e., Pagel's δ) suffer from wide confidence intervals, likely due to small sample size and deep divergence times. The scaling of segment masses appears to be more strongly related to the scaling of limb bone mass as opposed to length, and the scaling of hindlimb mass distribution is more a function of scale effects in limb posture than proximo-distal differences in the scaling of limb segment mass. Though negative allometry of segment masses appears to be precluded by the need for mechanically sound limbs, the positive allometry of segment masses relative to body mass may underlie scale effects in stride frequency and length between smaller and larger neognaths. While variation in linear proportions of limbs appear to be governed by developmental mechanisms, variation in mass proportions does not appear to be constrained so.

Scale effects and morphological diversification in hindlimb segment mass proportions in neognath birds

PubMed Central

2014-01-01

Introduction In spite of considerable work on the linear proportions of limbs in amniotes, it remains unknown whether differences in scale effects between proximal and distal limb segments has the potential to influence locomotor costs in amniote lineages and how changes in the mass proportions of limbs have factored into amniote diversification. To broaden our understanding of how the mass proportions of limbs vary within amniote lineages, I collected data on hindlimb segment masses – thigh, shank, pes, tarsometatarsal segment, and digits – from 38 species of neognath birds, one of the most speciose amniote clades. I scaled each of these traits against measures of body size (body mass) and hindlimb size (hindlimb length) to test for departures from isometry. Additionally, I applied two parameters of trait evolution (Pagel’s λ and δ) to understand patterns of diversification in hindlimb segment mass in neognaths. Results All segment masses are positively allometric with body mass. Segment masses are isometric with hindlimb length. When examining scale effects in the neognath subclade Land Birds, segment masses were again positively allometric with body mass; however, shank, pedal, and tarsometatarsal segment masses were also positively allometric with hindlimb length. Methods of branch length scaling to detect phylogenetic signal (i.e., Pagel’s λ) and increasing or decreasing rates of trait change over time (i.e., Pagel’s δ) suffer from wide confidence intervals, likely due to small sample size and deep divergence times. Conclusions The scaling of segment masses appears to be more strongly related to the scaling of limb bone mass as opposed to length, and the scaling of hindlimb mass distribution is more a function of scale effects in limb posture than proximo-distal differences in the scaling of limb segment mass. Though negative allometry of segment masses appears to be precluded by the need for mechanically sound limbs, the positive allometry of segment masses relative to body mass may underlie scale effects in stride frequency and length between smaller and larger neognaths. While variation in linear proportions of limbs appear to be governed by developmental mechanisms, variation in mass proportions does not appear to be constrained so. PMID:24876886

Evaluation of non-ST segment elevation acute chest pain syndromes with a novel low-profile continuous imaging ultrasound transducer.

PubMed

Chandraratna, P Anthony N; Mohar, Dilbahar S; Sidarous, Peter F; Brar, Prabhjyot; Miller, Jeffrey; Shah, Nissar; Kadis, John; Ali, Ashgar; Mohar, Prabhsimran

2012-09-01

This investigation was designed to test the hypothesis that continuous cardiac imaging using an ultrasound transducer developed in our laboratory (ContiScan) is superior to electrocardiogram (ECG) monitoring in the diagnosis of coronary artery disease (CAD) in patients with acute non-ST segment elevation chest pain syndromes. Seventy patients with intermediate to high probability of CAD who presented with typical anginal chest pain and no evidence of ST segment elevation on the ECG were studied. The 2.5-MHz transducer is spherical in its distal part mounted in an external housing to permit steering in 360 degrees. The transducer was placed at the left sternal border to image the left ventricular short-axis view and recorded on video tape at baseline, during and after episodes of chest pain. Two ECG leads were continuously monitored. The presence of CAD was confirmed by coronary arteriography or nuclear or echocardiographic stress testing. Twenty-four patients had regional wall motion abnormalities (RWMA) on their initial echo which were unchanged during the period of monitoring. All had evidence of CAD. Twenty-eight patients had transient RWMA. All had evidence of CAD. Eighteen patients had normal wall motion throughout the monitoring period, 14 of these had no evidence of CAD, and four had evidence of CAD. These four patients did not have chest pain during monitoring. The sensitivity, specificity, and accuracy of echocardiographic monitoring for diagnosing non-ST elevation myocardial infarction was 88%, 100%, and 91% respectively. The sensitivity, specificity, and accuracy of the ECG for diagnosis of CAD were 31%, 100%, and 52%, respectively. Echocardiography was superior to ECG (P < 0.001). The data indicate that continuous cardiac imaging is superior to ECG monitoring for the diagnosis of CAD in patients presenting with acute non-ST segment elevation chest pain syndromes. This technique could be a useful adjunct to ECG monitoring for myocardial ischemia in the acute care setting. © 2012, Wiley Periodicals, Inc.

Two translocating hydrophilic segments of a nascent chain span the ER membrane during multispanning protein topogenesis

PubMed Central

Kida, Yuichiro; Morimoto, Fumiko; Sakaguchi, Masao

2007-01-01

During protein integration into the endoplasmic reticulum, the N-terminal domain preceding the type I signal-anchor sequence is translocated through a translocon. By fusing a streptavidin-binding peptide tag to the N terminus, we created integration intermediates of multispanning membrane proteins. In a cell-free system, N-terminal domain (N-domain) translocation was arrested by streptavidin and resumed by biotin. Even when N-domain translocation was arrested, the second hydrophobic segment mediated translocation of the downstream hydrophilic segment. In one of the defined intermediates, two hydrophilic segments and two hydrophobic segments formed a transmembrane disposition in a productive state. Both of the translocating hydrophilic segments were crosslinked with a translocon subunit, Sec61α. We conclude that two translocating hydrophilic segment in a single membrane protein can span the membrane during multispanning topogenesis flanking the translocon. Furthermore, even after six successive hydrophobic segments entered the translocon, N-domain translocation could be induced to restart from an arrested state. These observations indicate the remarkably flexible nature of the translocon. PMID:18166653

A minimally sufficient model for rib proximal-distal patterning based on genetic analysis and agent-based simulations

PubMed Central

Mah, In Kyoung

2017-01-01

For decades, the mechanism of skeletal patterning along a proximal-distal axis has been an area of intense inquiry. Here, we examine the development of the ribs, simple structures that in most terrestrial vertebrates consist of two skeletal elements—a proximal bone and a distal cartilage portion. While the ribs have been shown to arise from the somites, little is known about how the two segments are specified. During our examination of genetically modified mice, we discovered a series of progressively worsening phenotypes that could not be easily explained. Here, we combine genetic analysis of rib development with agent-based simulations to conclude that proximal-distal patterning and outgrowth could occur based on simple rules. In our model, specification occurs during somite stages due to varying Hedgehog protein levels, while later expansion refines the pattern. This framework is broadly applicable for understanding the mechanisms of skeletal patterning along a proximal-distal axis. PMID:29068314

Regional Differences in Rat Vaginal Smooth Muscle Contractility and Morphology

PubMed Central

Skoczylas, Laura C.; Jallah, Zegbeh; Sugino, Yoshio; Stein, Suzan E.; Feola, Andrew; Yoshimura, Naoki

2013-01-01

The objective of this study was to define the regional differences in rat vaginal smooth muscle contractility and morphology. We evaluated circumferential segments from the proximal, middle, and distal rat vagina (n = 21) in vitro. Contractile responses to carbachol, phenylephrine, potassium chloride, and electrical field stimulation (EFS) were measured. Immunohistochemical analyses were also performed. The dose–response curves for carbachol- and phenylephrine-dependent contractions were different in the distal (P = .05, P = .04) compared to the proximal/middle regions. Adjusted for region-dependent changes in contractility, the distal vagina generated lower force in response to carbachol and higher force in response to phenylephrine. There was less force with increasing EFS frequency in the distal (P = .03), compared to the proximal/middle regions. Cholinergic versus adrenergic nerves were more frequent in the proximal region (P = .03). In summary, the results indicate that functional and morphological differences in smooth muscle and nerve fibers of the distal versus proximal/middle regions of the vagina exist. PMID:23298869

Capillary pericytes express α-smooth muscle actin, which requires prevention of filamentous-actin depolymerization for detection.

PubMed

Alarcon-Martinez, Luis; Yilmaz-Ozcan, Sinem; Yemisci, Muge; Schallek, Jesse; Kılıç, Kıvılcım; Can, Alp; Di Polo, Adriana; Dalkara, Turgay

2018-03-21

Recent evidence suggests that capillary pericytes are contractile and play a crucial role in the regulation of microcirculation. However, failure to detect components of the contractile apparatus in capillary pericytes, most notably α-smooth muscle actin (α-SMA), has questioned these findings. Using strategies that allow rapid filamentous-actin (F-actin) fixation (i.e. snap freeze fixation with methanol at -20°C) or prevent F-actin depolymerization (i.e. with F-actin stabilizing agents), we demonstrate that pericytes on mouse retinal capillaries, including those in intermediate and deeper plexus, express α-SMA. Junctional pericytes were more frequently α-SMA-positive relative to pericytes on linear capillary segments. Intravitreal administration of short interfering RNA (α-SMA-siRNA) suppressed α-SMA expression preferentially in high order branch capillary pericytes, confirming the existence of a smaller pool of α-SMA in distal capillary pericytes that is quickly lost by depolymerization. We conclude that capillary pericytes do express α-SMA, which rapidly depolymerizes during tissue fixation thus evading detection by immunolabeling. © 2018, Alarcon-Martinez et al.

Mechanisms of Barrett’s esophagus (clinical): LES dysfunction, hiatal hernia, peristaltic defects

PubMed Central

Roman, Sabine; Kahrilas, Peter J

2014-01-01

Summary Barrett’s esophagus, with the potential to develop into esophageal adenocarcinoma (EAC), is a major complication of gastroesophageal reflux disease (GERD). However, about 50% of patients developing EAC had no known GERD beforehand. Hence, while GERD symptoms, esophagitis, and Barrett’s have a number of common determinants (esophagogastric junction (EGJ) incompetence, impaired esophageal clearance mechanisms, hiatus hernia) they also have some independent determinants. Further, although excess esophageal acid exposure plays a major role in the genesis of long-segment Barrett’s esophagus there is minimal evidence supporting this for short-segment Barrett’s. Hence, these may have unique pathophysiological features as well. Long-segment Barrett’s seems to share most, if not all, of the risk factors for esophagitis, particularly high-grade esophagitis. However, it is uncertain if EGJ function and acid clearance are more severely impaired in patients with long-segment Barrett’s compared to patients with high-grade esophagitis. With respect to short-segment Barrett’s, the acid pocket may play an important pathogenic role. Conceptually, extension of the acid pocket into the distal esophagus, also known as intra-sphincteric reflux, provides a mechanism or acid exposure of the distal esophageal mucosa without the occurrence of discrete reflux events, which are more likely to prompt reflux symptoms and lead to the development of esophagitis. Hence, intra-sphincteric reflux related to extension of the acid/no acid interface at the proximal margin of the acid pocket may be key in the development of short segment Barrett’s. However, currently this is still somewhat speculative and further studies are required to confirm this. PMID:25743453

Could the peristaltic transition zone be caused by non-uniform esophageal muscle fiber architecture? A simulation study.

PubMed

Kou, W; Pandolfino, J E; Kahrilas, P J; Patankar, N A

2017-06-01

Based on a fully coupled computational model of esophageal transport, we analyzed how varied esophageal muscle fiber architecture and/or dual contraction waves (CWs) affect bolus transport. Specifically, we studied the luminal pressure profile in those cases to better understand possible origins of the peristaltic transition zone. Two groups of studies were conducted using a computational model. The first studied esophageal transport with circumferential-longitudinal fiber architecture, helical fiber architecture and various combinations of the two. In the second group, cases with dual CWs and varied muscle fiber architecture were simulated. Overall transport characteristics were examined and the space-time profiles of luminal pressure were plotted and compared. Helical muscle fiber architecture featured reduced circumferential wall stress, greater esophageal distensibility, and greater axial shortening. Non-uniform fiber architecture featured a peristaltic pressure trough between two high-pressure segments. The distal pressure segment showed greater amplitude than the proximal segment, consistent with experimental data. Dual CWs also featured a pressure trough between two high-pressure segments. However, the minimum pressure in the region of overlap was much lower, and the amplitudes of the two high-pressure segments were similar. The efficacy of esophageal transport is greatly affected by muscle fiber architecture. The peristaltic transition zone may be attributable to non-uniform architecture of muscle fibers along the length of the esophagus and/or dual CWs. The difference in amplitude between the proximal and distal pressure segments may be attributable to non-uniform muscle fiber architecture. © 2017 John Wiley & Sons Ltd.

A new marine cyclopoid copepod of the genus Neocyclops (Cyclopidae, Halicyclopinae) from Korea.

PubMed

Lee, Jimin; Chang, Cheon Young

2015-01-01

A new cyclopoid species of the genus Neocyclops Gurney, 1927 is described. Type specimens were collected from a beach on south-western coast of the Korean Peninsula by rinsing intertidal coarse sandy sediments. Neocyclops hoonsooi sp. n. is most characteristic in showing the conspicuous chitinized transverse ridges originating from the medial margins of the coxae of all swimming legs. The new species is most similar to Neocyclops vicinus, described from the Brazilian coast, and Neocyclops petkovskii, from Australia. All three species share a large body size (more than 750 µm long), the presence of an exopodal seta on the antenna, two setae on the mandibular palp, the same seta/spine armature on the third endopodal segment of leg 3 (3 setae + 3 spines), and the fairly long inner distal spine on the third endopodal segment of the female leg 4. However, Neocyclops hoonsooi sp. n. differs from both species by the much shorter caudal rami (less than 1.7 times as long as wide) and the shorter dorsal caudal seta VII. Furthermore, Neocyclops hoonsooi is clearly distinguished from Neocyclops vicinus by the 10-segmented antennule (vs 12 segments in Neocyclops vicinus), and from Neocyclops petkovskii by the elongate inner distal spine on leg 5 exopod and the 3-segmented leg 5 in male (vs 4-segmented in Neocyclops petkovskii). A tabular comparison of characters separating Neocyclops hoonsooi from its closest allies and a key to Neocyclops species from the Indo-Pacific Ocean are provided. This is the first record of the genus Neocyclops from the northern Pacific.

Mechanisms of Barrett's oesophagus (clinical): LOS dysfunction, hiatal hernia, peristaltic defects.

PubMed

Roman, Sabine; Kahrilas, Peter J

2015-02-01

Barrett's oesophagus, with the potential to develop into oesophageal adenocarcinoma (OAC), is a major complication of gastrooesophageal reflux disease (GORD). However, about 50% of patients developing OAC had no known GORD beforehand. Hence, while GORD symptoms, oesophagitis, and Barrett's have a number of common determinants (oesophagogastric junction (OGJ) incompetence, impaired oesophageal clearance mechanisms, hiatus hernia) they also have some independent determinants. Further, although excess oesophageal acid exposure plays a major role in the genesis of long-segment Barrett's oesophagus there is minimal evidence supporting this for short-segment Barrett's. Hence, these may have unique pathophysiological features as well. Long-segment Barrett's seems to share most, if not all, of the risk factors for oesophagitis, particularly high-grade oesophagitis. However, it is uncertain if OGJ function and acid clearance are more severely impaired in patients with long-segment Barrett's compared to patients with high-grade oesophagitis. With respect to short-segment Barrett's, the acid pocket may play an important pathogenic role. Conceptually, extension of the acid pocket into the distal oesophagus, also known as intra-sphincteric reflux, provides a mechanism or acid exposure of the distal osophageal mucosa without the occurrence of discrete reflux events, which are more likely to prompt reflux symptoms and lead to the development of oesophagitis. Hence, intra-sphincteric reflux related to extension of the acid/no acid interface at the proximal margin of the acid pocket may be key in the development of short segment Barrett's. However, currently this is still somewhat speculative and further studies are required to confirm this. Copyright © 2014 Elsevier Ltd. All rights reserved.

The effect of obesity and gender on body segment parameters in older adults

PubMed Central

Chambers, April J.; Sukits, Alison L.; McCrory, Jean L.; Cham, Rakié

2010-01-01

Background Anthropometry is a necessary aspect of aging-related research, especially in biomechanics and injury prevention. Little information is available on inertial parameters in the geriatric population that account for gender and obesity effects. The goal of this study was to report body segment parameters in adults aged 65 years and older, and to investigate the impact of aging, gender and obesity. Methods Eighty-three healthy old (65–75 yrs) and elderly (>75 yrs) adults were recruited to represent a range of body types. Participants underwent a whole body dual energy x-ray absorptiometry scan. Analysis was limited to segment mass, length, longitudinal center of mass position, and frontal plane radius of gyration. A mixed-linear regression model was performed using gender, obesity, age group and two-way and three-way interactions (α=0.05). Findings Mass distribution varied with obesity and gender. Males had greater trunk and upper extremity mass while females had a higher lower extremity mass. In general, obese elderly adults had significantly greater trunk segment mass with less thigh and shank segment mass than all others. Gender and obesity effects were found in center of mass and radius of gyration. Non-obese individuals possessed a more distal thigh and shank center of mass than obese. Interestingly, females had more distal trunk center of mass than males. Interpretation Age, obesity and gender have a significant impact on segment mass, center of mass and radius of gyration in old and elderly adults. This study underlines the need to consider age, obesity and gender when utilizing anthropometric data sets. PMID:20005028

Anatomic Patterns of Renal Arterial Sympathetic Innervation: New Aspects for Renal Denervation.

PubMed

Imnadze, Guram; Balzer, Stefan; Meyer, Baerbel; Neumann, Joerg; Krech, Rainer Horst; Thale, Joachim; Franz, Norbert; Warnecke, Henning; Awad, Khaled; Hayek, Salim S; Devireddy, Chandan

2016-12-01

Initial studies of catheter-based renal arterial sympathetic denervation to lower blood pressure in resistant hypertensive patients renewed interest in the sympathetic nervous system's role in the pathogenesis of hypertension. However, the SYMPLICITY HTN-3 study failed to meet its prespecified blood pressure lowering efficacy endpoint. To date, only a limited number of studies have described the microanatomy of renal nerves, of which, only two involve humans. Renal arteries were harvested from 15 cadavers from the Klinikum Osnabruck and Schuchtermann Klinik, Bad Rothenfelde. Each artery was divided longitudinally in equal thirds (proximal, middle, and distal), with each section then divided into equal superior, inferior, anterior, and posterior quadrants, which were then stained. Segments containing no renal nerves were given a score value = 0, 1-2 nerves with diameter <300 µm a score = 1; 3-4 nerves or nerve diameter 300-599 µm a score = 2, and >4 nerves or nerve diameter ≥600 µm a score = 3. A total of 22 renal arteries (9 right-sided, 13 left-sided) were suitable for examination. Overall, 691 sections of 5 mm thickness were prepared. Right renal arteries had significantly higher mean innervation grade (1.56 ± 0.85) compared to left renal arteries (1.09 ± 0.87) (P < 0.001). Medial (1.30 ± 0.59) and distal (1.39 ± 0.62) innervation was higher than the proximal (1.17 ± 0.55) segments (p < 0.001). When divided in quadrants, the anterior (1.52 ± 0.96) and superior (1.71 ± 0.89) segments were more innervated compared to posterior (0.96 ± 0.72) and inferior (0.90 ± 0.68) segments (P < 0.001). That the right renal artery has significantly higher innervation scores than the left. The anterior and superior quadrants of the renal arteries scored higher in innervation than the posterior and inferior quadrants did. The distal third of the renal arteries are more innervated than the more proximal segments. These findings warrant further evaluation of the spatial innervation patterns of the renal artery in order to understand how it may enhance catheter-based renal arterial denervation procedural strategy and outcomes. The SYMPLICITY HTN-3 study dealt a blow to the idea of the catheter-based renal arterial sympathetic denervation. We investigated the location and patterns of periarterial renal nerves in cadaveric human renal arteries. To quantify the density of the renal nerves we created a novel innervation score. On average the right renal arteries were significantly more densely innervated than the left renal arteries, the anterior and superior segments were significantly more innervated compared to the posterior and inferior segments, absolute innervation scores in the proximal third of the left or right renal arteries were always lower when compared to distal segments. These findings may enhance catheter-based renal arterial denervation procedural strategy and outcomes. © 2016, Wiley Periodicals, Inc.

Comparison of direct and indirect skeletal anchorage systems combined with 2 canine retraction techniques.

PubMed

Ozkan, Serkan; Bayram, Mehmet

2016-11-01

We compared the effectiveness of 2 canine retraction springs and anchorage systems (direct and indirect skeletal anchorage) in patients requiring first premolar extractions and maximum anchorage in the maxilla. Thirty-six patients were included (17 male, 19 female; mean age, 16.8 ± 2.4 years). A mini-implant-supported Nance appliance with indirect skeletal anchorage system was used in 18 patients and a mini-implant-supported direct skeletal anchorage system in the remaining patients. In each patient, a segmental retraction arch with a reverse closing loop was applied to a maxillary canine, and a Ladanyi spring (Dentaurum, Ispringen, Germany) was applied to the other canine randomly after extraction of the maxillary first premolars. The retraction process was continued until a Class I canine relationship was obtained. Lateral cephalometric films and orthodontic casts taken before and after retraction in the distalization process were used to evaluate changes during canine distalization. The measurements were statistically evaluated using paired and independent t tests with 95% confidence intervals. The reverse closing loop and the Ladanyi spring were found to be effective in canine distalization (P ≤0.001). There were no statistically significant differences between the reverse closing loop and the Ladanyi spring with regard to canine distalization rates (P ≥0.05). Both systems were effective in providing maximum anchorage (P ≥0.05); no statistically significant differences were detected in molar anchorage loss rates between the 2 methods (P ≥0.05). These 2 systems can be used during segmental distalization of canines requiring maximum anchorage with no significant anchorage loss. Copyright © 2016 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.

Nonmosaic tetrasomy 15q25.2 → qter identified with SNP microarray in a patient with characteristic facial appearance and review of the literature.

PubMed

Xu, Huihui; Xiao, Bing; Ji, Xing; Hu, Qin; Chen, Yingwei; Qiu, Wenjuan

2014-07-01

Tetrasomy for the distal chromosome 15q is rare, and only 22 patients (including 6 cases without detailed information) have been described to date in the literature. Here we report on another patient with nonmosaic tetrasomy 15q25.2-qter resulted from an inverted duplication of distal chromosome 15. This patient presents with features of development delay, arachnodactyly, joint contractures and typical facial dysmorphism including frontal bossing, short palpebral fissures, long philtrum, low-set ears, high-arched palate and retrognathia. Unlike most of the related patients, abdominal ultrasound test and brain MRI showed normal. Karyotyping analysis revealed a supernumerary marker chromosome presented in all metaphase cells examined. Parental karyotyping analysis was normal, indicating a de novo chromosome aberration of the patient. SNP microarray analysis found a two copy gain of 17.7 Mb from the distal long arm of chromosome 15 (15q25.2-qter). Further FISH analysis using SureFISH 15q26.3 IGF1R probe proved an inverted duplication of distal long arm of chromosome 15. The segmental duplications which lie in the hotspots of 15q24-26 might increase the susceptibility of chromosome rearrangement. Compared with the George-Abraham' study [2012], ADAMTSL3 might be more related to the cardiac disorders in tetrasomy 15q patients. Considering all patients reported in the literature, different mosaic degrees and segmental sizes don't correlate to the severity of phenotypes. A clear delineation on tetrasomy for distal chromosome 15q could still be investigated. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Temporary Iliac Fixation to Salvage an Acute L4 Chance Fracture: Following Pedicle Screw Fixation for Adolescent Idiopathic Scoliosis.

PubMed

Kato, So; Lewis, Stephen J

2017-03-01

A case report. The aim of this study was to describe a technique of temporary distal fixation to the ilium to salvage an acute L4 fracture following a T3-L4 kyphoscoliosis correction. Pedicle fracture is a possible complication in pedicle screw fixation for scoliosis, which may lead to postoperative instability, resulting in loss of fixation and pseudoarthrosis. This report highlights the salvage treatment of a chance fracture that occurred in the lower instrumented vertebra following deformity correction for adolescent idiopathic scoliosis (AIS) without sacrificing further distal motion segments. A retrospective chart and radiograph review of a 13-year-old female who underwent surgical treatment for correction of AIS was performed. Following a T3-L4 correction with apical posterior column releases, an L4 Chance fracture with loss of distal fixation occurred on post-op day 3. Following an unsuccessful salvage with an infralaminar hook, a second revision was performed replacing the hook and adding bilateral temporary fixation to the ilium connected to the distal ends of the main rods through side-to-side connectors. The temporary fixation was removed 6 months later with successful healing of the fracture maintenance of the scoliosis correction at 2-year follow-up. Temporary extension of the construct to the ilium was successfully utilized in this case to salvage an acute L4 Chance fracture that occurred following a T3 to L4 construct for kyphoscoliosis. With this technique, successful reduction and healing of the fracture occurred with maintenance of the deformity correction without the need to fuse further distal segments. 4.

A Study Demonstrating the Quantitative Relationship Between Internal Thoracic Artery Length and Free Flow.

PubMed

Gode, Safa; Sen, Onur; Kadirogulları, Ersin; Reyhancan, Adem; Kyaruzi, Mugisha; Satılmısoglu, Muhammet Hulusi; Erkanlı, Korhan

2017-08-09

The left internal thoracic artery (LITA) is the most commonly used arterial bypass conduit in coronary artery bypass graft (CABG) patients and inadequate LITA flow can result in an increase in morbidity and mortality. In this study, we evaluated the effect of excision of the distal spasmodic segment of the LITA on the free flow in CABG patients. This study consisted of 47 patients who underwent elective CABG performed with or without other cardiac surgery, between July 2015 and December 2015. Excised LITA length was shorter than 15mm in group 1, between 15mm and 30mm in group 2 and longer than 30mm in group 3. Left ITA free flow was measured for 60seconds into a container before and after the distal LITA excision. The inter-measurement differences were calculated for the three groups. Thereafter, the comparison was performed in terms of free flow difference amongst the three groups. The mean difference of LITA free flow was 27.6±22.7ml/minute in group 1, 35.4±26.7ml/minute in group 2, and 52.6±26.1ml/minute in group 3. There were significant differences in terms of free flow difference between the groups (p=0.008). Also, differences were statistically significant in group 1 versus group 3 (p=0.003) and group 2 versus group 3 (p=0.038) in the intergroup comparisons. The distal part of the LITA has more spasmodic potential than other segments. This spasm may result in low flow of LITA grafts. Therefore, an as long as possible excision of the distal LITA segment may be required to avoid the spasmodic effect. Copyright © 2017 Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) and the Cardiac Society of Australia and New Zealand (CSANZ). Published by Elsevier B.V. All rights reserved.

Calculating Transition Energy Barriers and Characterizing Activation States for Steps of Fusion

PubMed Central

Ryham, Rolf J.; Klotz, Thomas S.; Yao, Lihan; Cohen, Fredric S.

2016-01-01

We use continuum mechanics to calculate an entire least energy pathway of membrane fusion, from stalk formation, to pore creation, and through fusion pore enlargement. The model assumes that each structure in the pathway is axially symmetric. The static continuum stalk structure agrees quantitatively with experimental stalk architecture. Calculations show that in a stalk, the distal monolayer is stretched and the stored stretching energy is significantly less than the tilt energy of an unstretched distal monolayer. The string method is used to determine the energy of the transition barriers that separate intermediate states and the dynamics of two bilayers as they pass through them. Hemifusion requires a small amount of energy independently of lipid composition, while direct transition from a stalk to a fusion pore without a hemifusion intermediate is highly improbable. Hemifusion diaphragm expansion is spontaneous for distal monolayers containing at least two lipid components, given sufficiently negative diaphragm spontaneous curvature. Conversely, diaphragms formed from single-component distal monolayers do not expand without the continual injection of energy. We identify a diaphragm radius, below which central pore expansion is spontaneous. For larger diaphragms, prior studies have shown that pore expansion is not axisymmetric, and here our calculations supply an upper bound for the energy of the barrier against pore formation. The major energy-requiring deformations in the steps of fusion are: widening of a hydrophobic fissure in bilayers for stalk formation, splay within the expanding hemifusion diaphragm, and fissure widening initiating pore formation in a hemifusion diaphragm. PMID:26958888

Numerical investigation of liver radioembolization via computational particle-hemodynamics: The role of the microcatheter distal direction and microsphere injection point and velocity.

PubMed

Aramburu, Jorge; Antón, Raúl; Rivas, Alejandro; Ramos, Juan Carlos; Sangro, Bruno; Bilbao, José Ignacio

2016-11-07

Liver radioembolization is a treatment option for patients with primary and secondary liver cancer. The procedure consists of injecting radiation-emitting microspheres via an intra-arterially placed microcatheter, enabling the deposition of the microspheres in the tumoral bed. The microcatheter location and the particle injection rate are determined during a pretreatment work-up. The purpose of this study was to numerically study the effects of the injection characteristics during the first stage of microsphere travel through the bloodstream in a patient-specific hepatic artery (i.e., the near-tip particle-hemodynamics and the segment-to-segment particle distribution). Specifically, the influence of the distal direction of an end-hole microcatheter and particle injection point and velocity were analyzed. Results showed that the procedure targeted the right lobe when injecting from two of the three injection points under study and the remaining injection point primarily targeted the left lobe. Changes in microcatheter direction and injection velocity resulted in an absolute difference in exiting particle percentage for a given liver segment of up to 20% and 30%, respectively. It can be concluded that even though microcatheter placement is presumably reproduced in the treatment session relative to the pretreatment angiography, the treatment may result in undesired segment-to-segment particle distribution and therefore undesired treatment outcomes due to modifications of any of the parameters studied, i.e., microcatheter direction and particle injection point and velocity. Copyright © 2016 Elsevier Ltd. All rights reserved.

Polymorphic organization of the endoplasmic reticulum of the Malpighian tubule. Evidence for a transcellular route.

PubMed

Berthelet, F; Beaudry-Lonergan, M; Linares, H; Whittembury, G; Bergeron, M

1987-01-01

Isosmotic fluid absorption carried out by many mammalian epithelia appears to be similar to the isosmotic secretion of insect epithelia such as the Malpighian tubules, which are responsible for urine formation and osmoregulation. We have studied by electron microscopy (80 kV) the three-dimensional characteristics of organelles in the Malpighian tubules of Rhodnius prolixus using thick sections (0.3-0.5 microns) and uranyl and lead impregnation. The ER presents a different organization in the upper (distal) and lower (proximal) segments of the Malpighian tubule. In distal secretory segment, the ER forms a network made of chains of vesicles having irregular shapes (ca. 0.06 micron in diameter) connected to each other by canaliculi while in the lower absorptive segment, the ER is made of parallel saccules arranged in stacks or whorls in the central region of the cytoplasm. In both segments, the ER network extends throughout the cytoplasm from the basolateral infoldings to the apex between the many mitochondria present in these two areas. A unique feature of these cells, revealed by thick sections, is the presence in each microvillus of either a mitochondrion or an ER canaliculus in continuity with the ER network. The ER does not seem to have any specific association with mitochondria or other organelles. As in the mammalian nephron, this ER organization is most likely related to specific segmental functions and adds support to its potential role as a transcellular epithelial route.

Segmental heterogeneity in Bcl-2, Bcl-xL and Bax expression in rat tubular epithelium after ischemia-reperfusion.

PubMed

Valdés, Francisco; Pásaro, Eduardo; Díaz, Inmaculada; Centeno, Alberto; López, Eduardo; García-Doval, Sandra; González-Roces, Severino; Alba, Alfonso; Laffon, Blanca

2008-06-01

Studies in rats with bilateral clamping of renal arteries showed transient Bcl-2, Bcl-xL and Bax expression in renal tubular epithelium following ischemia-reperfusion. However, current data on the preferential localization of specific mRNAs or proteins are limited because gene expression was not analysed at segmental level. This study analyses the mRNA expression of Bcl-2, Bcl-xL and Bax in four segments of proximal and distal tubules localized in the renal cortex and outer medulla in rat kidneys with bilateral renal clamping for 30 min and seven reperfusion times versus control animals without clamp. Proximal convoluted tubule (PCT), distal convoluted tubule (DCT), proximal straight tubule (PST) and medullary thick ascending limb (MTAL) were obtained by manual microdissection. RT-PCR was used to analyse mRNA expression at segmental level. Proximal convoluted tubule and MTAL showed early, persistent and balanced up-regulation of Bcl-2, Bcl-xL and Bax, while PST and DCT revealed only Bcl-2 and Bcl-xL, when only Bax was detected in PST. DCT expressed Bcl-xL initially, and persistent Bcl-2 later. These patterns suggest a heterogeneous apoptosis regulatory response in rat renal tubules after ischemia-reperfusion, independently of cortical or medullary location. This heterogeneity of the expression patterns of Bcl-2 genes could explain the different susceptibility to undergo apoptosis, the different threshold to ischemic damage and the different adaptive capacity to injury among these tubular segments.

A second case of inv(4)pat with both recombinants in the offspring: rec dup(4q) in a girl with Wolf-Hirschhorn syndrome and rec dup(4p).

PubMed

Dufke, A; Eggermann, K; Balg, S; Stengel-Rutkowski, S; Enders, H; Kaiser, P

2000-01-01

In a girl presenting with features of Wolf-Hirschhorn syndrome, cytogenetic and molecular cytogenetic analysis revealed a rearranged chromosome 4 with monosomy of the distal bands 4pter-->4p16.2 and trisomy of the distal bands 4q35.1-->4qter [rec dup(4q)] due to a large, paternal pericentric inversion. In the following two pregnancies, prenatal diagnosis showed the same imbalance in one fetus and a reverse segmental imbalance [rec dup(4p)] in the other. We discuss the recombination risk of the given inversion with respect to the size of the inverted segment and the viability of the recombinants. The high frequency of recombinants in this family and others suggests a high recurrence risk in similar cases with large pericentric inversions comprising almost entire chromosomes. Copyright 2001 S. Karger AG, Basel.

[A Distal Bile Duct Carcinoma Patient Who Underwent Surgical Resection for Liver Metastasis].

PubMed

Komiyama, Sosuke; Izumiya, Yasuhito; Kimura, Yu; Nakashima, Shingo; Kin, Syuichi; Kawakami, Sadao

2018-03-01

A 70-year-old man with distal bile duct carcinoma underwent a subtotal stomach-preserving pancreaticoduodenectomy without adjuvant chemotherapy. One and a half years after the surgery, elevated levels of serum SPan-1(38.1 U/mL)were observed and CT scans demonstrated a solitary metastasis, 25mm in size, in segment 8 of the liver. The patient received 2 courses of gemcitabine-cisplatin combination chemotherapy. No new lesions were detected after chemotherapy and the patient underwent a partial liver resection of segment 8. The pathological examination revealed a metachronous distant metastasis originating from the bile duct carcinoma. Subsequently, the patient received S-1 adjuvant chemotherapy for 6 months. Following completion of all therapies, the patient survived without tumor recurrence for 3 years and 10 months after the initial operation. Thus, surgical interventions might be effective in improving prognosis among selected patients with postoperative liver metastasis of bile duct carcinoma.

De novo tandem duplication of chromosome segement 22q11-q12: Clinical, cytogenetic, and molecular characterization

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

Lindsay, E.A.; Shaffer, L.G.; Carrozzo, R.

We report on a case of duplication of the segment 22q11-q12 due to a de novo duplication. Molecular cytogenetics studies demonstrated this to be a tandem duplication, flanked proximally by the marker D22Z4, a centromeric alpha satellite DNA repeat, and distally by D22S260, an anonymous DNA marker proximal to the Ewing sarcoma breakpoint. The segment includes the regions responsible for the {open_quotes}cat-eye{close_quotes}, Di George, and velo-cardio-facial syndromes and extends distal to the breakpoint cluster region (BCR). The clinical picture is dominated by the cardiac defects and includes findings reminiscent of {open_quotes}cat-eye{close_quotes} syndrome. These findings reinforce the hypothesis that the proximalmore » 22q region contains dosage-sensitive genes involved in development. 20 refs., 3 figs.« less

Surgical Correction of Truncus Arteriosus With Unusual Origin of the Right Coronary Artery.

PubMed

Rodríguez, Humberto; Montero, Hernán; Fernández, Antonio; Guzman, Armando; Sessa, Thomas Di

2016-05-01

An 11-year-old male with a diagnosis of truncus arteriosus (common arterial trunk) with origin of the right coronary artery anteriorly from the pulmonary segment of the common trunk underwent reparative surgery. The pulmonary trunk was long, and it had a kink with stenosis that protected the distal pulmonary vascular bed from elevated pressure. Adequate flow allowed well-developed distal branch pulmonary arteries. An oval incision was made in the pulmonary trunk, which created a flap. At its center was the right coronary artery. This flap, which remained attached to the aorta proximally, was then used to close the aortic defect. The segment of the pulmonary trunk with stenosis was resected. The patient's pericardium was used to fashion a valved conduit that was interposed between the right ventricle and the confluence of the pulmonary artery branches. © The Author(s) 2016.

A de novo 11q23 deletion in a patient presenting with severe ophthalmologic findings, psychomotor retardation and facial dysmorphism.

PubMed

Şimşek-Kiper, Pelin Özlem; Bayram, Yavuz; Ütine, Gülen Eda; Alanay, Yasemin; Boduroğlu, Koray

2014-01-01

Distal 11q deletion, previously known as Jacobsen syndrome, is caused by segmental aneusomy for the distal end of the long arm of chromosome 11. Typical clinical features include facial dysmorphism, mild-to-moderate psychomotor retardation, trigonocephaly, cardiac defects, and thrombocytopenia. There is a significant variability in the range of clinical features. We report herein a five-year-old girl with severe ophthalmological findings, facial dysmorphism, and psychomotor retardation with normal platelet function, in whom a de novo 11q23 deletion was detected, suggesting that distal 11q monosomy should be kept in mind in patients presenting with dysmorphic facial features and psychomotor retardation even in the absence of hematological findings.

Branching morphogenesis in the fetal mouse submandibular gland is codependent on growth factors and extracellular matrix.

PubMed

Gresik, Edward W; Koyama, Noriko; Hayashi, Toru; Kashimata, Masanori

2009-01-01

Branching morphogenesis (BrM) is a basic developmental process for the formation of the lung, kidney, and all exocrine glands, including the salivary glands. This process proceeds as follows. An epithelial downgrowth invaginates into underlying mesenchyme, and forms a cleft at its distal end, which is the site of dichotomous branching and elongation; this process of clefting and elongation is repeated many times at the distal ends of the invading epithelium until the desired final extent of branching is reached. The distal ends of the epithelium differentiate into the secretory endpieces, and the elongated segments become the ducts. This presentation is a brief historical review of studies on BrM during the development of the submandibular gland (SMG).

Molecular population genetics of inversion breakpoint regions in Drosophila pseudoobscura.

PubMed

Wallace, Andre G; Detweiler, Don; Schaeffer, Stephen W

2013-07-08

Paracentric inversions in populations can have a profound effect on the pattern and organization of nucleotide variability along a chromosome. Regions near inversion breakpoints are expected to have greater levels of differentiation because of reduced genetic exchange between different gene arrangements whereas central regions in the inverted segments are predicted to have lower levels of nucleotide differentiation due to greater levels of genetic flux among different karyotypes. We used the inversion polymorphism on the third chromosome of Drosophila pseudoobscura to test these predictions with an analysis of nucleotide diversity of 18 genetic markers near and away from inversion breakpoints. We tested hypotheses about how the presence of different chromosomal arrangements affects the pattern and organization of nucleotide variation. Overall, markers in the distal segment of the chromosome had greater levels of nucleotide heterozygosity than markers within the proximal segment of the chromosome. In addition, our results rejected the hypothesis that the breakpoints of derived inversions will have lower levels of nucleotide variability than breakpoints of ancestral inversions, even when strains with gene conversion events were removed. High levels of linkage disequilibrium were observed within all 11 breakpoint regions as well as between the ends of most proximal and distal breakpoints. The central region of the chromosome had the greatest levels of linkage disequilibrium compared with the proximal and distal regions because this is the region that experiences the highest level of recombination suppression. These data do not fully support the idea that genetic exchange is the sole force that influences genetic variation on inverted chromosomes.

Does improvement in self-management skills predict improvement in quality of life and depressive symptoms? A prospective study in patients with heart failure up to one year after self-management education.

PubMed

Musekamp, Gunda; Schuler, Michael; Seekatz, Bettina; Bengel, Jürgen; Faller, Hermann; Meng, Karin

2017-02-15

Heart failure (HF) patient education aims to foster patients' self-management skills. These are assumed to bring about, in turn, improvements in distal outcomes such as quality of life. The purpose of this study was to test the hypothesis that change in self-reported self-management skills observed after participation in self-management education predicts changes in physical and mental quality of life and depressive symptoms up to one year thereafter. The sample comprised 342 patients with chronic heart failure, treated in inpatient rehabilitation clinics, who received a heart failure self-management education program. Latent change modelling was used to analyze relationships between both short-term (during inpatient rehabilitation) and intermediate-term (after six months) changes in self-reported self-management skills and both intermediate-term and long-term (after twelve months) changes in physical and mental quality of life and depressive symptoms. Short-term changes in self-reported self-management skills predicted intermediate-term changes in mental quality of life and long-term changes in physical quality of life. Intermediate-term changes in self-reported self-management skills predicted long-term changes in all outcomes. These findings support the assumption that improvements in self-management skills may foster improvements in distal outcomes.

The healing process of intracorporeally and in situ devitalized distal femur by microwave in a dog model and its mechanical properties in vitro.

PubMed

Ji, Zhenwei; Ma, Yunlei; Li, Wei; Li, Xiaoxiang; Zhao, Guangyi; Yun, Zhe; Qian, Jixian; Fan, Qingyu

2012-01-01

Limb-salvage surgery has been well recognized as a standard treatment and alternative to amputation for patients with malignant bone tumors. Various limb-sparing techniques have been developed including tumor prosthesis, allograft, autograft and graft-prosthesis composite. However, each of these methods has short- and long-term disadvantages such as nonunion, mechanical failures and poor limb function. The technique of intracorporeal devitalization of tumor-bearing bone segment in situ by microwave-induced hyperthermia after separating it from surrounding normal tissues with a safe margin is a promising limb-salvage method, which may avoid some shortcomings encountered by the above-mentioned conventional techniques. The purpose of this study is to assess the healing process and revitalization potential of the devitalized bone segment by this method in a dog model. In addition, the immediate effect of microwave on the biomechanical properties of bone tissue was also explored in an in vitro experiment. We applied the microwave-induced hyperthermia to devitalize the distal femurs of dogs in situ. Using a monopole microwave antenna, we could produce a necrotic bone of nearly 20 mm in length in distal femur. Radiography, bone scintigraphy, microangiography, histology and functional evaluation were performed at 2 weeks and 1, 2, 3, 6, 9 and 12 months postoperatively to assess the healing process. In a biomechanical study, two kinds of bone specimens, 3 and 6 cm in length, were used for compression and three-point bending test respectively immediately after extracorporeally devitalized by microwave. An in vivo study showed that intracorporeally and in situ devitalized bone segment by microwave had great revitalization potential. An in vitro study revealed that the initial mechanical strength of the extracorporeally devitalized bone specimen may not be affected by microwave. Our results suggest that the intracorporeal microwave devitalization of tumor-bearing bone segment in situ may be a promising limb-salvage method.

Posterior subscapular dissection: An improved approach to the brachial plexus for human anatomy students.

PubMed

Hager, Shaun; Backus, Timothy Charles; Futterman, Bennett; Solounias, Nikos; Mihlbachler, Matthew C

2014-05-01

Students of human anatomy are required to understand the brachial plexus, from the proximal roots extending from spinal nerves C5 through T1, to the distal-most branches that innervate the shoulder and upper limb. However, in human cadaver dissection labs, students are often instructed to dissect the brachial plexus using an antero-axillary approach that incompletely exposes the brachial plexus. This approach readily exposes the distal segments of the brachial plexus but exposure of proximal and posterior segments require extensive dissection of neck and shoulder structures. Therefore, the proximal and posterior segments of the brachial plexus, including the roots, trunks, divisions, posterior cord and proximally branching peripheral nerves often remain unobserved during study of the cadaveric shoulder and brachial plexus. Here we introduce a subscapular approach that exposes the entire brachial plexus, with minimal amount of dissection or destruction of surrounding structures. Lateral retraction of the scapula reveals the entire length of the brachial plexus in the subscapular space, exposing the brachial plexus roots and other proximal segments. Combining the subscapular approach with the traditional antero-axillary approach allows students to observe the cadaveric brachial plexus in its entirety. Exposure of the brachial dissection in the subscapular space requires little time and is easily incorporated into a preexisting anatomy lab curriculum without scheduling additional time for dissection. Copyright © 2014 Elsevier GmbH. All rights reserved.

Trends in mercury concentrations in the hair of women of Nome, Alaska - Evidence of seafood consumption or abiotic absorption

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

Lasorsa, B.

1992-06-01

Eighty samples of hair from women of child-bearing age from Nome, Alaska, and seven control samples from women living in Sequim, Washington, were analyzed for mercury concentration by segmental analysis in an effort to determine whether seasonal fluctuations in mercury concentration in the hair samples can be correlated to seasonal seafood consumption. Full-length hair strands were analyzed in 1.1-cm segments representing 1 month's growth using a strong acid digestion and cold vapor atomic fluorescence analysis. It was assumed that the concentration of mercury in each segment is an indicator of the mercury body burden during the month in which themore » segment emerged from the scalp. Eighteen of the samples show seasonal variability, with five of the controls and one Nome resident showing winter highs while all Nome residents show summer highs. Twenty-six of the samples show an increase in mercury concentration toward the distal end of the strand regardless of month of growth. The trend of increasing mercury concentrations toward the distal end of the hair strand regardless of month of emergence, and the documented presence of elevated levels of elemental mercury in the Nome area suggest that these elevated levels may actually be due to external contamination of the hair strands by adsorption and not due to ingestion of contaminated foodstuffs such as seafood.« less

Trends in mercury concentrations in the hair of women of Nome, Alaska - Evidence of seafood consumption or abiotic absorption?

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

Lasorsa, B.

1992-06-01

Eighty samples of hair from women of child-bearing age from Nome, Alaska, and seven control samples from women living in Sequim, Washington, were analyzed for mercury concentration by segmental analysis in an effort to determine whether seasonal fluctuations in mercury concentration in the hair samples can be correlated to seasonal seafood consumption. Full-length hair strands were analyzed in 1.1-cm segments representing 1 month`s growth using a strong acid digestion and cold vapor atomic fluorescence analysis. It was assumed that the concentration of mercury in each segment is an indicator of the mercury body burden during the month in which themore » segment emerged from the scalp. Eighteen of the samples show seasonal variability, with five of the controls and one Nome resident showing winter highs while all Nome residents show summer highs. Twenty-six of the samples show an increase in mercury concentration toward the distal end of the strand regardless of month of growth. The trend of increasing mercury concentrations toward the distal end of the hair strand regardless of month of emergence, and the documented presence of elevated levels of elemental mercury in the Nome area suggest that these elevated levels may actually be due to external contamination of the hair strands by adsorption and not due to ingestion of contaminated foodstuffs such as seafood.« less

Method for assessing the need for case-specific hemodynamics: application to the distribution of vascular permeability.

PubMed

Hazel, A L; Friedman, M H

2000-01-01

A common approach to understanding the role of hemodynamics in atherogenesis is to seek relationships between parameters of the hemodynamic environment, and the distribution of tissue variables thought to be indicative of early disease. An important question arising in such investigations is whether the distributions of tissue variables are sufficiently similar among cases to permit them to be described by an ensemble average distribution. If they are, the hemodynamic environment needs be determined only once, for a nominal representative geometry; if not, the hemodynamic environment must be obtained for each case. A method for classifying distributions from multiple cases to answer this question is proposed and applied to the distributions of the uptake of Evans blue dye labeled albumin by the external iliac arteries of swine in response to a step increase in flow. It is found that the uptake patterns in the proximal segment of the arteries, between the aortic trifurcation and the ostium of the circumflex iliac artery, show considerable case-to-case variability. In the distal segment, extending to the deep femoral ostium, many cases show very little spatial variation, and the patterns in those that do are similar among the cases. Thus the response of the distal segment may be understood with fewer simulations, but the proximal segment has more information to offer.

Anatomic, histologic, and two-dimensional-echocardiographic evaluation of mitral valve anatomy in dogs.

PubMed

Borgarelli, Michele; Tursi, Massimiliano; La Rosa, Giuseppe; Savarino, Paolo; Galloni, Marco

2011-09-01

To compare echocardiographic variables of dogs with postmortem anatomic measurements and histologic characteristics of the mitral valve (MV). 21 cardiologically normal dogs. The MV was measured echocardiographically by use of the right parasternal 5-chamber long-axis view. Dogs were euthanized, and anatomic measurements of the MV annulus (MVa) were performed at the level of the left circumflex coronary artery. Mitral valve leaflets (MVLs) and chordae tendineae were measured. Structure of the MVLs was histologically evaluated in 3 segments (proximal, middle, and distal). Echocardiographic measurements of MVL length did not differ significantly from anatomic measurements. A positive correlation was detected between body weight and MVa area. There was a negative correlation between MVa area and the percentage by which the MVL area exceeded the MVa area. Anterior MVLs had a significantly higher number of chordae tendineae than did posterior MVLs. Histologically, layering of MVLs was less preserved in the distal segment, whereas the muscular component and adipose tissue were significantly more diffuse in the proximal and middle segments. The MV in cardiologically normal dogs had wide anatomic variability. Anatomic measurements of MVL length were correlated with echocardiographic measurements.

Evaluation of segmental left ventricular wall motion by equilibrium gated radionuclide ventriculography.

PubMed

Van Nostrand, D; Janowitz, W R; Holmes, D R; Cohen, H A

1979-01-01

The ability of equilibrium gated radionuclide ventriculography to detect segmental left ventricular (LV) wall motion abnormalities was determined in 26 patients undergoing cardiac catheterization. Multiple gated studies obtained in 30 degrees right anterior oblique and 45 degrees left anterior oblique projections, played back in a movie format, were compared to the corresponding LV ventriculograms. The LV wall in the two projections was divided into eight segments. Each segment was graded as normal, hypokinetic, akinetic, dyskinetic, or indeterminate. Thirteen percent of the segments in the gated images were indeterminate; 24 out of 27 of these were proximal or distal inferior wall segments. There was exact agreement in 86% of the remaining segments. The sensitivity of the radionuclide technique for detecting normal versus any abnormal wall motion was 71%, with a specificity of 99%. Equilibrium gated ventriculography is an excellent noninvasive technique for evaluating segmental LV wall motion. It is least reliable in assessing the proximal inferior wall and interventricular septum.

Stabilization of Volar Ulnar Rim Fractures of the Distal Radius: Current Techniques and Review of the Literature

PubMed Central

O'Shaughnessy, Maureen A.; Shin, Alexander Y.; Kakar, Sanjeev

2016-01-01

Background Distal radius fractures involving the lunate facet can be challenging to manage. Reports have shown the volar carpal subluxation/dislocation that can occur if the facet is not appropriately stabilized. Literature Review Recent emphasis in the literature has underscored the difficulty in managing this fracture fragment, suggesting standard volar plates may not be able to adequately stabilize the fragment. This article reviews the current literature with a special emphasis on fixation with a specifically designed fragment-specific hook plate to secure the lunate facet. Case Description An extended flexor carpi radialis volar approach was made which allows access to the distal volar ulnar fracture fragment. Once provisionally stabilized with Kirschner wire fixation, a volar hook plate was applied to capture this fragment. Additional fracture stabilization was used as deemed necessary to stabilize the remaining distal radius fracture. Clinical Relevance The volar marginal rim fragment remains a challenge in distal radius fracture management. Use of a hook plate to address the volar ulnar corner allows for stable fixation without loss of reduction at intermediate-term follow-up. PMID:27104076

Rapid totally diverting loop sigmoid colostomy with noncontaminating rectal irrigation.

PubMed

Sachatello, C R; Maull, K I

1977-08-01

Loop sigmoid colostomy employing a stapling device and catheter irrigation of the distal segment is less time-consuming and has lest potential for contamination than the standard double-barrel colostomy. Unlike the standard loop colostomy, it is totally diverting.

Partial co-option of the appendage patterning pathway in the development of abdominal appendages in the sepsid fly Themira biloba

PubMed Central

Nijhout, H. Frederik

2014-01-01

The abdominal appendages on male Themira biloba (Diptera: Sepsidae) are complex novel structures used during mating. These abdominal appendages superficially resemble the serially homologous insect appendages in that they have a joint and a short segment that can be rotated. Non-genital appendages do not occur in adult pterygote insects, so these abdominal appendages are novel structures with no obvious ancestry. We investigated whether the genes that pattern the serially homologous insect appendages have been co-opted to pattern these novel abdominal appendages. Immunohistochemistry was used to determine the expression patterns of the genes extradenticle (exd), Distal-less (Dll), engrailed (en), Notch, and the Bithorax Complex in the appendages of T. biloba during pupation. The expression patterns of Exd, En, and Notch were consistent with the hypothesis that a portion of the patterning pathway that establishes the coxopodite has been co-opted to pattern the developing abdominal appendages. However, Dll was only expressed in the bristles of the developing appendages and not the proximal–distal axis of the appendage itself. The lack of Dll expression indicates the absence of a distal domain of the appendage suggesting that sepsid abdominal appendages only use genes that normally pattern the base of segmental appendages. PMID:20182886

The visceromotor and somatic afferent nerves of the penis.

PubMed

Diallo, Djibril; Zaitouna, Mazen; Alsaid, Bayan; Quillard, Jeanine; Ba, Nathalie; Allodji, Rodrigue Sètchéou; Benoit, Gérard; Bedretdinova, Dina; Bessede, Thomas

2015-05-01

Innervation of the penis supports erectile and sensory functions. This article aims to study the efferent autonomic (visceromotor) and afferent somatic (sensory) nervous systems of the penis and to investigate how these systems relate to vascular pathways. Penises obtained from five adult cadavers were studied via computer-assisted anatomic dissection (CAAD). The number of autonomic and somatic nerve fibers was compared using the Kruskal-Wallis test. Proximally, penile innervation was mainly somatic in the extra-albugineal sector and mainly autonomic in the intracavernosal sector. Distally, both sectors were almost exclusively supplied by somatic nerve fibers, except the intrapenile vascular anastomoses that accompanied both somatic and autonomic (nitrergic) fibers. From this point, the neural immunolabeling within perivascular nerve fibers was mixed (somatic labeling and autonomic labeling). Accessory afferent, extra-albugineal pathways supplied the outer layers of the penis. There is a major change in the functional type of innervation between the proximal and distal parts of the intracavernosal sector of the penis. In addition to the pelvis and the hilum of the penis, the intrapenile neurovascular routes are the third level where the efferent autonomic (visceromotor) and the afferent somatic (sensory) penile nerve fibers are close. Intrapenile neurovascular pathways define a proximal penile segment, which guarantees erectile rigidity, and a sensory distal segment. © 2015 International Society for Sexual Medicine.

Object-oriented approach to the automatic segmentation of bones from pediatric hand radiographs

NASA Astrophysics Data System (ADS)

Shim, Hyeonjoon; Liu, Brent J.; Taira, Ricky K.; Hall, Theodore R.

1997-04-01

The purpose of this paper is to develop a robust and accurate method that automatically segments phalangeal and epiphyseal bones from digital pediatric hand radiographs exhibiting various stages of growth. The development of this system draws principles from object-oriented design, model- guided analysis, and feedback control. A system architecture called 'the object segmentation machine' was implemented incorporating these design philosophies. The system is aided by a knowledge base where all model contours and other information such as age, race, and sex, are stored. These models include object structure models, shape models, 1-D wrist profiles, and gray level histogram models. Shape analysis is performed first by using an arc-length orientation transform to break down a given contour into elementary segments and curves. Then an interpretation tree is used as an inference engine to map known model contour segments to data contour segments obtained from the transform. Spatial and anatomical relationships among contour segments work as constraints from shape model. These constraints aid in generating a list of candidate matches. The candidate match with the highest confidence is chosen to be the current intermediate result. Verification of intermediate results are perform by a feedback control loop.

Using external and internal locking plates in a two-stage protocol for treatment of segmental tibial fractures.

PubMed

Ma, Ching-Hou; Tu, Yuan-Kun; Yeh, Jih-Hsi; Yang, Shih-Chieh; Wu, Chin-Hsien

2011-09-01

The tibial segmental fractures usually follow high-energy trauma and are often associated with many complications. We designed a two-stage protocol for these complex injuries. The aim of this study was to assess the outcome of tibial segmental fractures treated according to this protocol. A prospective series of 25 consecutive segmental tibial fractures were treated using a two-stage procedure. In the first stage, a low-profile locking plate was applied as an external fixator to temporarily immobilize the fractures after anatomic reduction had been achieved followed by soft-tissue reconstruction. The second stage involved definitive internal fixation with a locking plate using a minimally invasive percutaneous plate osteosynthesis technique. The median follow-up was 32 months (range, 20-44 months). All fractures achieved union. The median time for the proximal fracture union was 23 weeks (range, 12-30 weeks) and that for distal fracture union was 27 weeks (range, 12-46 weeks; p = 0.08). Functional results were excellent in 21 patients and good in 4 patients. There were three cases of delayed union of distal fracture. Valgus malunion >5 degrees occurred in two patients, and length discrepancy >1 cm was observed in two patients. Pin tract infection occurred in three patients. Use of the two-stage procedure for treatment of segmental tibial fractures is recommended. Surgeons can achieve good reduction with stable temporary fixation, soft-tissue reconstruction, ease of subsequent definitive fixation, and high union rates. Our patients obtained excellent knee and ankle joint motion, good functional outcomes, and a comfortable clinical course.

Calculating Transition Energy Barriers and Characterizing Activation States for Steps of Fusion.

PubMed

Ryham, Rolf J; Klotz, Thomas S; Yao, Lihan; Cohen, Fredric S

2016-03-08

We use continuum mechanics to calculate an entire least energy pathway of membrane fusion, from stalk formation, to pore creation, and through fusion pore enlargement. The model assumes that each structure in the pathway is axially symmetric. The static continuum stalk structure agrees quantitatively with experimental stalk architecture. Calculations show that in a stalk, the distal monolayer is stretched and the stored stretching energy is significantly less than the tilt energy of an unstretched distal monolayer. The string method is used to determine the energy of the transition barriers that separate intermediate states and the dynamics of two bilayers as they pass through them. Hemifusion requires a small amount of energy independently of lipid composition, while direct transition from a stalk to a fusion pore without a hemifusion intermediate is highly improbable. Hemifusion diaphragm expansion is spontaneous for distal monolayers containing at least two lipid components, given sufficiently negative diaphragm spontaneous curvature. Conversely, diaphragms formed from single-component distal monolayers do not expand without the continual injection of energy. We identify a diaphragm radius, below which central pore expansion is spontaneous. For larger diaphragms, prior studies have shown that pore expansion is not axisymmetric, and here our calculations supply an upper bound for the energy of the barrier against pore formation. The major energy-requiring deformations in the steps of fusion are: widening of a hydrophobic fissure in bilayers for stalk formation, splay within the expanding hemifusion diaphragm, and fissure widening initiating pore formation in a hemifusion diaphragm. Copyright © 2016 Biophysical Society. Published by Elsevier Inc. All rights reserved.

Optimizing Soft Tissue Management and Spacer Design in Segmental Bone Defects

DTIC Science & Technology

2016-12-01

proximal and distal bone segments. 3. Debride 10 grams of tibialis anterior and gastrocnemius muscles. 4. Place an interlocking intramedullary nail ...using a custom spacer to maintain 5-cm defect length. 5. Place a pre-molded 5 cm long x 2 cm diameter PMMA spacer around the nail in the defect. 6...tibia. 3. Open the IM surrounding the PMMA spacer using a “bomb bay door opening”. 4. Remove the spacer without damaging the membrane or nail . 5

Decreased glycolytic and tricarboxylic acid cycle intermediates coincide with peripheral nervous system oxidative stress in a murine model of type 2 diabetes.

PubMed

Hinder, Lucy M; Vivekanandan-Giri, Anuradha; McLean, Lisa L; Pennathur, Subramaniam; Feldman, Eva L

2013-01-01

Diabetic neuropathy (DN) is the most common complication of diabetes and is characterized by distal-to-proximal loss of peripheral nerve axons. The idea of tissue-specific pathological alterations in energy metabolism in diabetic complications-prone tissues is emerging. Altered nerve metabolism in type 1 diabetes models is observed; however, therapeutic strategies based on these models offer limited efficacy to type 2 diabetic patients with DN. Therefore, understanding how peripheral nerves metabolically adapt to the unique type 2 diabetic environment is critical to develop disease-modifying treatments. In the current study, we utilized targeted liquid chromatography-tandem mass spectrometry (LC/MS/MS) to characterize the glycolytic and tricarboxylic acid (TCA) cycle metabolomes in sural nerve, sciatic nerve, and dorsal root ganglia (DRG) from male type 2 diabetic mice (BKS.Cg-m+/+Lepr(db); db/db) and controls (db/+). We report depletion of glycolytic intermediates in diabetic sural nerve and sciatic nerve (glucose-6-phosphate, fructose-6-phosphate, fructose-1,6-bisphosphate (sural nerve only), 3-phosphoglycerate, 2-phosphoglycerate, phosphoenolpyruvate, and lactate), with no significant changes in DRG. Citrate and isocitrate TCA cycle intermediates were decreased in sural nerve, sciatic nerve, and DRG from diabetic mice. Utilizing LC/electrospray ionization/MS/MS and HPLC methods, we also observed increased protein and lipid oxidation (nitrotyrosine; hydroxyoctadecadienoic acids) in db/db tissue, with a proximal-to-distal increase in oxidative stress, with associated decreased aconitase enzyme activity. We propose a preliminary model, whereby the greater change in metabolomic profile, increase in oxidative stress, and decrease in TCA cycle enzyme activity may cause distal peripheral nerves to rely on truncated TCA cycle metabolism in the type 2 diabetes environment.

Evaluating the Impact of the U.S. National Toxicology Program: A Case Study on Hexavalent Chromium

PubMed Central

Xie, Yun; Holmgren, Stephanie; Andrews, Danica M. K.; Wolfe, Mary S.

2016-01-01

Background: Evaluating the impact of federally funded research with a broad, methodical, and objective approach is important to ensure that public funds advance the mission of federal agencies. Objectives: We aimed to develop a methodical approach that would yield a broad assessment of National Toxicology Program’s (NTP’s) effectiveness across multiple sectors and demonstrate the utility of the approach through a case study. Methods: A conceptual model was developed with defined activities, outputs (products), and outcomes (proximal, intermediate, distal) and applied retrospectively to NTP’s research on hexavalent chromium (CrVI). Proximal outcomes were measured by counting views of and requests for NTP’s products by external stakeholders. Intermediate outcomes were measured by bibliometric analysis. Distal outcomes were assessed through Web and LexisNexis searches for documents related to legislation or regulation changes. Results: The approach identified awareness of NTP’s work on CrVI by external stakeholders (proximal outcome) and citations of NTP’s research in scientific publications, reports, congressional testimonies, and legal and policy documents (intermediate outcome). NTP’s research was key to the nation’s first-ever drinking water standard for CrVI adopted by California in 2014 (distal outcome). By applying this approach to a case study, the utility and limitations of the approach were identified, including challenges to evaluating the outcomes of a research program. Conclusions: This study identified a broad and objective approach for assessing NTP’s effectiveness, including methodological needs for more thorough and efficient impact assessments in the future. Citation: Xie Y, Holmgren S, Andrews DMK, Wolfe MS. 2017. Evaluating the impact of the U.S. National Toxicology Program: a case study on hexavalent chromium. Environ Health Perspect 125:181–188; http://dx.doi.org/10.1289/EHP21 PMID:27483499

Evaluating the Impact of the U.S. National Toxicology Program: A Case Study on Hexavalent Chromium.

PubMed

Xie, Yun; Holmgren, Stephanie; Andrews, Danica M K; Wolfe, Mary S

2017-02-01

Evaluating the impact of federally funded research with a broad, methodical, and objective approach is important to ensure that public funds advance the mission of federal agencies. We aimed to develop a methodical approach that would yield a broad assessment of National Toxicology Program's (NTP's) effectiveness across multiple sectors and demonstrate the utility of the approach through a case study. A conceptual model was developed with defined activities, outputs (products), and outcomes (proximal, intermediate, distal) and applied retrospectively to NTP's research on hexavalent chromium (CrVI). Proximal outcomes were measured by counting views of and requests for NTP's products by external stakeholders. Intermediate outcomes were measured by bibliometric analysis. Distal outcomes were assessed through Web and LexisNexis searches for documents related to legislation or regulation changes. The approach identified awareness of NTP's work on CrVI by external stakeholders (proximal outcome) and citations of NTP's research in scientific publications, reports, congressional testimonies, and legal and policy documents (intermediate outcome). NTP's research was key to the nation's first-ever drinking water standard for CrVI adopted by California in 2014 (distal outcome). By applying this approach to a case study, the utility and limitations of the approach were identified, including challenges to evaluating the outcomes of a research program. This study identified a broad and objective approach for assessing NTP's effectiveness, including methodological needs for more thorough and efficient impact assessments in the future. Citation: Xie Y, Holmgren S, Andrews DMK, Wolfe MS. 2017. Evaluating the impact of the U.S. National Toxicology Program: a case study on hexavalent chromium. Environ Health Perspect 125:181-188; http://dx.doi.org/10.1289/EHP21.

Combined effects of cotyledon excision and nursery fertilization on root growth, nutrient status and outplanting performance of Quercus variabilis container seedlings

PubMed Central

Shi, Wenhui; Bloomberg, Mark; Li, Guolei; Su, Shuchai; Jia, Liming

2017-01-01

Artificial excision of the distal part of acorns in order to promote germination is well researched in oak seedling cultivation studies. However, studies of combined effects of cotyledon excision and nursery fertilization on container seedlings are lacking, especially for seedling root growth and outplanting performance. This study aimed to explore the main effects of cotyledon excision on Quercus variabilis seedling emergence characteristics and demonstrated the combined effects of cotyledon excision and nursery fertilization on seedling quality to improve Quercus variabilis seedling outplanting performance. Four cotyledon excision treatments and two classes of nursery fertilization were implemented. Seedling emergence was noted every week after sowing. Seedling dry mass, morphology, and nutrient status were assessed at the end of the nursery season. After the first outplanting season, the aforementioned measurements along with seedling survival were determined once again. The results showed that cotyledon excision generally induced greater and more rapid seedling emergence, but did not affect shoot emergence synchronicity. The highest total emergence and emergence rate occurred with Intermediate excision (1/2 of the distal end of acorn was excised). Effects of nutrient loss due to cotyledon excision on seedling quality and outplanting performance were somewhat compensated by nursery fertilization. Nursery fertilization promoted dry mass increment (the net increment from T0 to T2 for dry mass) for excised seedlings after outplanting, resulting in better performance for Slight (1/3 of the distal end of acorn was excised) and Intermediate excision treatments in the field. Thus we conclude Intermediate excision combined with reasonable nursery fertilization can be recommended for production of nursery grown seedlings for afforestation. PMID:28545103

Combined effects of cotyledon excision and nursery fertilization on root growth, nutrient status and outplanting performance of Quercus variabilis container seedlings.

PubMed

Shi, Wenhui; Bloomberg, Mark; Li, Guolei; Su, Shuchai; Jia, Liming

2017-01-01

Artificial excision of the distal part of acorns in order to promote germination is well researched in oak seedling cultivation studies. However, studies of combined effects of cotyledon excision and nursery fertilization on container seedlings are lacking, especially for seedling root growth and outplanting performance. This study aimed to explore the main effects of cotyledon excision on Quercus variabilis seedling emergence characteristics and demonstrated the combined effects of cotyledon excision and nursery fertilization on seedling quality to improve Quercus variabilis seedling outplanting performance. Four cotyledon excision treatments and two classes of nursery fertilization were implemented. Seedling emergence was noted every week after sowing. Seedling dry mass, morphology, and nutrient status were assessed at the end of the nursery season. After the first outplanting season, the aforementioned measurements along with seedling survival were determined once again. The results showed that cotyledon excision generally induced greater and more rapid seedling emergence, but did not affect shoot emergence synchronicity. The highest total emergence and emergence rate occurred with Intermediate excision (1/2 of the distal end of acorn was excised). Effects of nutrient loss due to cotyledon excision on seedling quality and outplanting performance were somewhat compensated by nursery fertilization. Nursery fertilization promoted dry mass increment (the net increment from T0 to T2 for dry mass) for excised seedlings after outplanting, resulting in better performance for Slight (1/3 of the distal end of acorn was excised) and Intermediate excision treatments in the field. Thus we conclude Intermediate excision combined with reasonable nursery fertilization can be recommended for production of nursery grown seedlings for afforestation.

Bone architecture adaptations after spinal cord injury: impact of long-term vibration of a constrained lower limb.

PubMed

Dudley-Javoroski, S; Petrie, M A; McHenry, C L; Amelon, R E; Saha, P K; Shields, R K

2016-03-01

This study examined the effect of a controlled dose of vibration upon bone density and architecture in people with spinal cord injury (who eventually develop severe osteoporosis). Very sensitive computed tomography (CT) imaging revealed no effect of vibration after 12 months, but other doses of vibration may still be useful to test. The purposes of this report were to determine the effect of a controlled dose of vibratory mechanical input upon individual trabecular bone regions in people with chronic spinal cord injury (SCI) and to examine the longitudinal bone architecture changes in both the acute and chronic state of SCI. Participants with SCI received unilateral vibration of the constrained lower limb segment while sitting in a wheelchair (0.6g, 30 Hz, 20 min, three times weekly). The opposite limb served as a control. Bone mineral density (BMD) and trabecular micro-architecture were measured with high-resolution multi-detector CT. For comparison, one participant was studied from the acute (0.14 year) to the chronic state (2.7 years). Twelve months of vibration training did not yield adaptations of BMD or trabecular micro-architecture for the distal tibia or the distal femur. BMD and trabecular network length continued to decline at several distal femur sub-regions, contrary to previous reports suggesting a "steady state" of bone in chronic SCI. In the participant followed from acute to chronic SCI, BMD and architecture decline varied systematically across different anatomical segments of the tibia and femur. This study supports that vibration training, using this study's dose parameters, is not an effective anti-osteoporosis intervention for people with chronic SCI. Using a high-spatial-resolution CT methodology and segmental analysis, we illustrate novel longitudinal changes in bone that occur after spinal cord injury.

HIRSCHSPRUNG'S DISEASE—The Clinical Differentiation and Treatment of Children with Hirschsprung's Disease and Pseudo-Hirschsprung's Disease

PubMed Central

Ravitch, Mark M.

1958-01-01

Hirschsprung's disease is marked by constipation from the time of birth, with the development, if uncorrected, of a protuberant abdomen and flared costal margins. The rectal ampulla is empty and the abdomen is filled with fecal masses. Pain is not prominent. Flatus is passed in large amounts. Encopresis does not occur. Barium enema shows the characteristic narrowed distal rectal segment and biopsy of the rectum shows absence of the ganglion cells of the myenteric plexus. Treatment is operative resection of the distal narrow segment and a primary anastomosis. Hirschsprung's disease may be mimicked in children with: 1. Psychogenic constipation—pseudo-Hirschsprung's disease. Unlike Hirschsprung's disease, symptoms do not appear at birth, encopresis is common, and the barium enema shows no narrow distal segment. 2. Mental retardation and cerebral defect. 3. Corrected imperforate anus—on the basis of stenosis, imperfect innervation or poor habit training. 4. Cretinism—with severe constipation and intestinal dilatation perhaps the presenting symptoms. Treatment of these four groups of children with severe constipation not due to Hirschsprung's disease is: For Group 1, open discussion with parent and child. Assumption by the physician of full control of the details of treatment, and relegation of parent to the role of the physician's agent in following the prescribed regimen. For Group 2, an enema regimen. Whereas fairly rapid restoration (and then persistence) of normal bowel habit can be expected in Group 1, the basic defects in Group 2 may require indefinite continuation of treatment. For Group 3, regular enema regimen, in the less severe cases—one identical with that used in Group 1, and dilatation of strictures or anoplasty. In Group 4, thyroid hormone therapy relieves the constipation of hypothyroidism and causes reversion of radiographic changes in the colon and rectum. PMID:13561108

Microneurosurgical management of aneurysms at A4 and A5 segments and distal cortical branches of anterior cerebral artery.

PubMed

Lehecka, Martin; Dashti, Reza; Hernesniemi, Juha; Niemelä, Mika; Koivisto, Timo; Ronkainen, Antti; Rinne, Jaakko; Jääskeläinen, Juha

2008-10-01

Aneurysms originating distal to the A3 segment of the ACA, located on the A4 and the A5 segments or the distal cortical branches of the ACA (AdistAs) are rare, forming about 0.5% of all IAs. There are only few reports on management of AdistAs. In this article, we review the practical anatomy, preoperative planning, and avoidance of complications in the microsurgical dissection and clipping of AdistAs. This review, and the whole series on IAs, is mainly based on the personal microneurosurgical experience of the senior author (J. H.) in 2 Finnish centers (Helsinki and Kuopio), which serve without patient selection the catchment area in Southern and Eastern Finland. These 2 centers have treated more than 10000 patients with IAs since 1951. In the Kuopio Cerebral Aneurysm Database of 3005 patients and 4253 IAs, there were 26 patients carrying 26 AdistAs, forming 0.9% of all patients with IAs, 0.6% of all IAs, and 2% of all ACA aneurysms. A total of 10 (38%) patients presented with ruptured AdistAs, with ICH in 4 (40%) and IVH in 2 (20%); 16 patients (62%) had multiple aneurysms. AdistAs are small, even when ruptured, with relatively wide base, and they are frequently associated with ICHs. Our data suggest that AdistAs rupture at smaller size than IAs in general. The challenge is to locate the aneurysm inside the interhemispheric fissure and to clip the neck adequately without obstructing branching arteries at the base. Unruptured AdistAs also need microneurosurgical clipping even when they are small.

Branch architecture in Ginkgo biloba: wood anatomy and long shoot-short shoot interactions.

PubMed

Little, Stefan A; Jacobs, Brooke; McKechnie, Steven J; Cooper, Ranessa L; Christianson, Michael L; Jernstedt, Judith A

2013-10-01

Ginkgo, centrally placed in seed plant phylogeny, is considered important in many phylogenetic and evolutionary studies. Shoot dimorphism of Ginkgo has been long noted, but no work has yet been done to evaluate the relationships between overall branch architecture and wood ring characters, shoot growth, and environmental conditions. • Branches, sampled from similar canopy heights, were mapped with the age of each long shoot segment determined by counting annual leaf-scar series on its short shoots. Transverse sections were made for each long shoot segment and an adjacent short shoot; wood ring thickness, number of rings, and number of tracheids/ring were determined. Using branch maps, we identified wood rings for each long shoot segment to year and developmental context of each year (distal short shoot growth only vs. at least one distal long shoot). Climate data were also analyzed in conjunction with developmental context. • Significantly thicker wood rings occur in years with distal long shoot development. The likelihood that a branch produced long shoots in a given year was lower with higher maximum annual temperature. Annual maximum temperature was negatively correlated with ring thickness in microsporangiate trees only. Annual minimum temperatures were correlated differently with ring thickness of megasporangiate and microsporangiate trees, depending on the developmental context. There were no significant effects associated with precipitation. • Overall, developmental context alone predicts wood ring thickness about as well as models that include temperature. This suggests that although climatic factors may be strongly correlated with wood ring data among many gymnosperm taxa, at least for Ginkgo, correlations with climate data are primarily due to changes in proportions of shoot developmental types (LS vs. SS) across branches.

Restoration of the Patient-Specific Anatomy of the Proximal and Distal Parts of the Humerus: Statistical Shape Modeling Versus Contralateral Registration Method.

PubMed

Vlachopoulos, Lazaros; Lüthi, Marcel; Carrillo, Fabio; Gerber, Christian; Székely, Gábor; Fürnstahl, Philipp

2018-04-18

In computer-assisted reconstructive surgeries, the contralateral anatomy is established as the best available reconstruction template. However, existing intra-individual bilateral differences or a pathological, contralateral humerus may limit the applicability of the method. The aim of the study was to evaluate whether a statistical shape model (SSM) has the potential to predict accurately the pretraumatic anatomy of the humerus from the posttraumatic condition. Three-dimensional (3D) triangular surface models were extracted from the computed tomographic data of 100 paired cadaveric humeri without a pathological condition. An SSM was constructed, encoding the characteristic shape variations among the individuals. To predict the patient-specific anatomy of the proximal (or distal) part of the humerus with the SSM, we generated segments of the humerus of predefined length excluding the part to predict. The proximal and distal humeral prediction (p-HP and d-HP) errors, defined as the deviation of the predicted (bone) model from the original (bone) model, were evaluated. For comparison with the state-of-the-art technique, i.e., the contralateral registration method, we used the same segments of the humerus to evaluate whether the SSM or the contralateral anatomy yields a more accurate reconstruction template. The p-HP error (mean and standard deviation, 3.8° ± 1.9°) using 85% of the distal end of the humerus to predict the proximal humeral anatomy was significantly smaller (p = 0.001) compared with the contralateral registration method. The difference between the d-HP error (mean, 5.5° ± 2.9°), using 85% of the proximal part of the humerus to predict the distal humeral anatomy, and the contralateral registration method was not significant (p = 0.61). The restoration of the humeral length was not significantly different between the SSM and the contralateral registration method. SSMs accurately predict the patient-specific anatomy of the proximal and distal aspects of the humerus. The prediction errors of the SSM depend on the size of the healthy part of the humerus. The prediction of the patient-specific anatomy of the humerus is of fundamental importance for computer-assisted reconstructive surgeries.

The first metatarsal web space: its applied anatomy and usage in tracing the first dorsal metatarsal artery in thumb reconstruction.

PubMed

Xu, Yong-Qing; Li, Jun; Zhong, Shi-Zhen; Xu, Da-Chuan; Xu, Xiao-Shan; Guo, Yuan-Fa; Wang, Xin-Min; Li, Zhu-Yi; Zhu, Yue-Liang

2004-12-01

To clarify the anatomical relationship of the structures in the first toe webbing space for better dissection of toes in thumb reconstruction. The first dorsal metatarsal artery, the first deep transverse metatarsal ligament and the extensor expansion were observed on 42 adult cadaveric lower extremities. Clinically the method of tracing the first dorsal metatarsal artery around the space of the extensor expansion was used in 36 cases of thumb reconstruction. The distal segments of the first dorsal metatarsal artery of Gilbert types I and II were located superficially to the extensor expansion. The harvesting time of a toe was shortened from 90 minutes to 50 minutes with 100% survival of reconstructed fingers. The distal segment of the first dorsal metatarsal artery lies constantly at the superficial layer of the extensor expansion. Most of the first metatarsal arteries of Gilbert types I and II can be easily located via the combined sequential and reverse dissection around the space of the extensor expansion.

Metatarsal Osteotomies: Complications.

PubMed

Reddy, Veerabhadra Babu

2018-03-01

Metatarsal osteotomies can be divided into proximal and distal. The proximal osteotomies, such as the oblique, segmental, set cut, and Barouk-Rippstein-Toullec (BRT) osteotomy, all provide the ability to significantly change the position of the metatarsal head without violating the joint. These osteotomies, however, have a high rate of nonunion when done without internal fixation and can lead to transfer metatarsalgia when done without regard to the parabola of metatarsal head position. Distal osteotomies such as the Weil and Helal offer superior healing but have an increased incidence of recurrent metatarsalgia, joint stiffness, and floating toe. Copyright © 2017 Elsevier Inc. All rights reserved.

Wyeomyia (Prosopolepis) Confusa (Lutz): Subgeneric Validation, Species Description, and Recognition of Wyeomyia Flui (Bonne-Wepster and Bonne) as the Senior Synonym of Wyeomyia Kerri Del Ponte and Cerqueira

DTIC Science & Technology

1999-01-01

Short, length about 0.5 mm; widest at base, tapering distally; index 2.5-3.3 (width mea- sured at base); lightly and evenly tanned. Pecten with 3-9...compressed and expanded distally, with hooked tip. Segment X: Saddle incomplete; lightly tanned; length about 0.25 mm, siphon/saddle index about...cylindrical; index about 3.6 (2.5-4.1) (width measured at midlength). Ab- domen: Lightly tanned, anterior margins of sterna II-VI noticeably darker; length

Reproducibility of Direct Quantitative Measures of Cortical Bone Micro-architecture of the Distal Radius and Tibia by HR-pQCT

PubMed Central

Burghardt, Andrew J.; Buie, Helen R.; Laib, Andres; Majumdar, Sharmila; Boyd, Steven K.

2010-01-01

Quantitative cortical micro-architectural endpoints are important for understanding structure-function relations in the context of fracture risk and therapeutic efficacy. This technique study details new image-processing methods to automatically segment and directly quantify cortical density, geometry, and micro-architecture from HR-pQCT images of the distal radius and tibia. An automated segmentation technique was developed to identify the periosteal and endosteal margins of the distal radius and tibia, and detect intra-cortical pore space morphologically consistent with Haversian canals. The reproducibility of direct quantitative cortical bone indices based on this method was assessed in a pooled dataset of 56 subjects with two repeat acquisitions for each site. The in vivo precision error was characterized using root mean square coefficient of variation (RMSCV%) from which, the least significant change (LSC) was calculated. Bland-Altman plots were used to characterize bias in the precision estimates. The reproducibility of cortical density and cross-sectional area measures was high (RMSCV <1% and <1.5%, respectively) with good agreement between young and elder medians. The LSC for cortical porosity (Ct.Po) was somewhat smaller in the radius (0.58%) compared with the distal tibia (0.84%) and significantly different between young and elder medians in the distal tibia (LSC: 0.75% vs. 0.92%; p<0.001). The LSC for pore diameter and distribution (Po.Dm and Po.Dm.SD) ranged between 15 and 23μm. Bland-Altman analysis revealed moderate bias for integral measures of area and volume, but not density nor microarchitecture. This study indicates HR-pQCT measures of cortical bone density and architecture can be measured in vivo with high reproducibility and limited bias across a biologically relevant range of values. The results of this study provide informative data for the design of future clinical studies of bone quality. PMID:20561906

Risk factors for lower urinary tract infection and bacterial stent colonization in patients with a double J ureteral stent.

PubMed

Akay, Ali Ferruh; Aflay, Uğur; Gedik, Abdullah; Sahin, Hayrettin; Bircan, Mehmet Kamuran

2007-01-01

We investigated the potential risk factors for lower urinary tract infection and bacterial stent colonization in patients with double-J stents. A total of 195 double-J stents from 190 patients (95 men and 95 women, mean age 40.22 years) were examined. In all patients, prophylactic antimicrobial therapy was administered at the time of stenting. The stents and urine samples were removed aseptically and the proximal and distal tip segments of the stents were obtained. Three culture specimens were obtained from each stent segment and urine sample. Chi-square tests, odds ratio, and relative risk were used for the statistical analysis. Bacterial colonies were found in 24% (47 of 190) of the urine samples, 31% (61 of 195) of the proximal stent segments, and 34% (67 of 195) of the distal stent segments. Of the pathogens identified, Escherichia coli (34 of 47) was the most common. Diabetes mellitus (P < 0.01), chronic renal failure (P < 0.001), and pregnancy (P < 0.01) were found to be risk factors for lower urinary tract infection in patients with stents. An increased stent colonization rate was associated with implantation time, age, and female sex, but these were not statistically significant for lower urinary tract infection Diabetes mellitus, chronic renal failure, and pregnancy are associated with a higher risk of lower urinary tract infection. Therefore, patients in these categories should be monitored carefully for infectious complications.

PLEKHG5 deficiency leads to an intermediate form of autosomal-recessive Charcot–Marie–Tooth disease

PubMed Central

Azzedine, Hamid; Zavadakova, Petra; Planté-Bordeneuve, Violaine; Vaz Pato, Maria; Pinto, Nuno; Bartesaghi, Luca; Zenker, Jennifer; Poirot, Olivier; Bernard-Marissal, Nathalie; Arnaud Gouttenoire, Estelle; Cartoni, Romain; Title, Alexandra; Venturini, Giulia; Médard, Jean-Jacques; Makowski, Edward; Schöls, Ludger; Claeys, Kristl G.; Stendel, Claudia; Roos, Andreas; Weis, Joachim; Dubourg, Odile; Leal Loureiro, José; Stevanin, Giovanni; Said, Gérard; Amato, Anthony; Baraban, Jay; LeGuern, Eric; Senderek, Jan; Rivolta, Carlo; Chrast, Roman

2013-01-01

Charcot–Marie–Tooth disease (CMT) comprises a clinically and genetically heterogeneous group of peripheral neuropathies characterized by progressive distal muscle weakness and atrophy, foot deformities and distal sensory loss. Following the analysis of two consanguineous families affected by a medium to late-onset recessive form of intermediate CMT, we identified overlapping regions of homozygosity on chromosome 1p36 with a combined maximum LOD score of 5.4. Molecular investigation of the genes from this region allowed identification of two homozygous mutations in PLEKHG5 that produce premature stop codons and are predicted to result in functional null alleles. Analysis of Plekhg5 in the mouse revealed that this gene is expressed in neurons and glial cells of the peripheral nervous system, and that knockout mice display reduced nerve conduction velocities that are comparable with those of affected individuals from both families. Interestingly, a homozygous PLEKHG5 missense mutation was previously reported in a recessive form of severe childhood onset lower motor neuron disease (LMND) leading to loss of the ability to walk and need for respiratory assistance. Together, these observations indicate that different mutations in PLEKHG5 lead to clinically diverse outcomes (intermediate CMT or LMND) affecting the function of neurons and glial cells. PMID:23777631

Theory on the mechanism of distal action of transcription factors: looping of DNA versus tracking along DNA

NASA Astrophysics Data System (ADS)

Murugan, R.

2010-10-01

In this paper, we develop a theory on the mechanism of distal action of the transcription factors, which are bound at their respective cis-regulatory enhancer modules on the promoter-RNA polymerase II (PR) complexes to initiate the transcription event in eukaryotes. We consider both the looping and tracking modes of their distal communication and calculate the mean first passage time that is required for the distal interactions of the complex of enhancer and transcription factor with the PR via both these modes. We further investigate how this mean first passage time is dependent on the length of the DNA segment (L, base-pairs) that connects the cis-regulatory binding site and the respective promoter. When the radius of curvature of this connecting segment of DNA is R that was induced upon binding of the transcription factor at the cis-acting element and RNAPII at the promoter in cis-positions, our calculations indicate that the looping mode of distal action will dominate when L is such that L > 2πR and the tracking mode of distal action will be favored when L < 2πR. The time required for the distal action will be minimum when L = 2πR where the typical value of R for the binding of histones will be R ~ 16 bps and L ~ 102 bps. It seems that the free energy associated with the binding of the transcription factor with its cis-acting element and the distance of this cis-acting element from the corresponding promoter of the gene of interest is negatively correlated. Our results suggest that the looping and tracking modes of distal action are concurrently operating on the transcription activation and the physics that determines the timescales associated with the looping/tracking in the mechanism of action of these transcription factors on the initiation of the transcription event must put a selection pressure on the distribution of the distances of cis-regulatory modules from their respective promoters of the genes. The computational analysis of the upstream sequences of promoters of various genes in the human and mouse genomes for the presence of putative cis-regulatory elements for a set of known transcription factors using the position weight matrices available with the JASPAR database indicates the presence of cis-acting elements with maximum probability at a distance of ~102 bps from the promoters which substantiates our theoretical predictions.

Performance of a risk index for advanced proximal colorectal neoplasia among a racially/ethnically diverse patient population (risk index for advanced proximal neoplasia).

PubMed

Levitzky, Benjamin E; Brown, Colin C; Heeren, Timothy C; Schroy, Paul C

2011-06-01

Tailoring the use of screening colonoscopy based on the risk of advanced proximal neoplasia (APN) has been advocated as a strategy for reducing demand and optimizing effectiveness. A 7-point index based on age, sex, and distal findings at sigmoidoscopy has been proposed that stratifies individuals into low, intermediate, and high-risk categories. The aim of this cross-sectional analysis was to determine the validity of this index, which was originally derived and validated among mostly whites, for black and Hispanic patients. Data, including age, sex, colonoscopic findings, and pathology, were collected retrospectively from 1,481 white, 1,329 black, and 689 Hispanic asymptomatic, average-risk patients undergoing screening colonoscopy between 2000 and 2005. Cumulative scores ranging from 0 to 7 were derived for each subject and categorized as low, intermediate, or high risk. Rates of APN were assessed for each risk category after stratification by race/ethnicity. Index performance was assessed using the C-statistic and compared across the three racial groups. Rates of APN among patients categorized as low, intermediate, or high risk increased from 1.0 to 2.8 to 3.7% for whites, 1.0 to 2.2 to 4.2% for blacks, and 0.6 to 1.9 to 3.7% for Hispanics. The index performed similarly for all three groups, but showed limited ability to discriminate low from intermediate-risk patients, with C-statistic values of 0.62 for whites, 0.63 for blacks, and 0.68 for Hispanics. A risk index based on age, sex, and distal endoscopic findings has limited ability to discriminate low from intermediate-risk white, black, and Hispanic patients for APN.

Spreading rate dependence of gravity anomalies along oceanic transform faults.

PubMed

Gregg, Patricia M; Lin, Jian; Behn, Mark D; Montési, Laurent G J

2007-07-12

Mid-ocean ridge morphology and crustal accretion are known to depend on the spreading rate of the ridge. Slow-spreading mid-ocean-ridge segments exhibit significant crustal thinning towards transform and non-transform offsets, which is thought to arise from a three-dimensional process of buoyant mantle upwelling and melt migration focused beneath the centres of ridge segments. In contrast, fast-spreading mid-ocean ridges are characterized by smaller, segment-scale variations in crustal thickness, which reflect more uniform mantle upwelling beneath the ridge axis. Here we present a systematic study of the residual mantle Bouguer gravity anomaly of 19 oceanic transform faults that reveals a strong correlation between gravity signature and spreading rate. Previous studies have shown that slow-slipping transform faults are marked by more positive gravity anomalies than their adjacent ridge segments, but our analysis reveals that intermediate and fast-slipping transform faults exhibit more negative gravity anomalies than their adjacent ridge segments. This finding indicates that there is a mass deficit at intermediate- and fast-slipping transform faults, which could reflect increased rock porosity, serpentinization of mantle peridotite, and/or crustal thickening. The most negative anomalies correspond to topographic highs flanking the transform faults, rather than to transform troughs (where deformation is probably focused and porosity and alteration are expected to be greatest), indicating that crustal thickening could be an important contributor to the negative gravity anomalies observed. This finding in turn suggests that three-dimensional magma accretion may occur near intermediate- and fast-slipping transform faults.

Collecting Duct Intercalated Cell Function and Regulation

PubMed Central

Roy, Ankita; Al-bataineh, Mohammad M.

2015-01-01

Intercalated cells are kidney tubule epithelial cells with important roles in the regulation of acid-base homeostasis. However, in recent years the understanding of the function of the intercalated cell has become greatly enhanced and has shaped a new model for how the distal segments of the kidney tubule integrate salt and water reabsorption, potassium homeostasis, and acid-base status. These cells appear in the late distal convoluted tubule or in the connecting segment, depending on the species. They are most abundant in the collecting duct, where they can be detected all the way from the cortex to the initial part of the inner medulla. Intercalated cells are interspersed among the more numerous segment-specific principal cells. There are three types of intercalated cells, each having distinct structures and expressing different ensembles of transport proteins that translate into very different functions in the processing of the urine. This review includes recent findings on how intercalated cells regulate their intracellular milieu and contribute to acid-base regulation and sodium, chloride, and potassium homeostasis, thus highlighting their potential role as targets for the treatment of hypertension. Their novel regulation by paracrine signals in the collecting duct is also discussed. Finally, this article addresses their role as part of the innate immune system of the kidney tubule. PMID:25632105

A cloned DNA segment from the telomeric region of human chromosome 4p is not detectably rearranged in Huntington disease patients

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

Pritchard, C.; Casher, D.; Myers, R.M.

1990-09-01

Genetic linkage studies have mapped the Huntington disease (HD) mutation to the distal region of the short arm of human chromosome 4. Analysis of recombination events in this region has produced contradictory locations for HD. One possible location is in the region distal to the D4S90 marker, which is located within 300 kilobases of the telomere. Other crossover events predict a more centromeric position for HD. Here the authors analyze the telomeric region of 4p in detail. Cloned DNA segments were derived from this region by utilizing a radiation-induced somatic cell hybrid as a source of DNA combined with preparativemore » pulsed-field gel electrophoresis to enrich for the telmoeric fraction. Additional DNA was obtained by using the cloned segments as multiple start points for cosmid walks. This strategy proved to be an effective method for cloning 250 kilobases of DNA in the region telomeric to D4S90. Hybridization analysis with the cloned DNA did not provide any evidence for the presence of rearrangements of 100 base pairs or greater in the DNA of individuals affected with HD. They also found no charge in the size or structure of the 4p telomere in these samples.« less

Energy flow analysis of amputee walking shows a proximally-directed transfer of energy in intact limbs, compared to a distally-directed transfer in prosthetic limbs at push-off.

PubMed

Weinert-Aplin, R A; Howard, D; Twiste, M; Jarvis, H L; Bennett, A N; Baker, R J

2017-01-01

Reduced capacity and increased metabolic cost of walking occurs in amputees, despite advances in prosthetic componentry. Joint powers can quantify deficiencies in prosthetic gait, but do not reveal how energy is exchanged between limb segments. This study aimed to quantify these energy exchanges during amputee walking. Optical motion and forceplate data collected during walking at a self-selected speed for cohorts of 10 controls, 10 unilateral trans-tibial, 10 unilateral trans-femoral and 10 bilateral trans-femoral amputees were used to determine the energy exchanges between lower limb segments. At push-off, consistent thigh and shank segment powers were observed between amputee groups (1.12W/kg vs. 1.05W/kg for intact limbs and 0.97W/kg vs. 0.99W/kg for prosthetic limbs), and reduced prosthetic ankle power, particularly in trans-femoral amputees (3.12W/kg vs. 0.87W/kg). Proximally-directed energy exchange was observed in the intact limbs of amputees and controls, while prosthetic limbs displayed distally-directed energy exchanges at the knee and hip. This study used energy flow analysis to show a reversal in the direction in which energy is exchanged between prosthetic limb segments at push-off. This reversal was required to provide sufficient energy to propel the limb segments and is likely a direct result of the lack of push-off power at the prosthetic ankle, particularly in trans-femoral amputees, and leads to their increased metabolic cost of walking. Copyright © 2016 IPEM. Published by Elsevier Ltd. All rights reserved.

Flow-Through Free Fibula Osteocutaneous Flap in Reconstruction of Tibial Bone, Soft Tissue, and Main Artery Segmental Defects.

PubMed

Li, Zonghuan; Yu, Aixi; Qi, Baiwen; Pan, Zhenyu; Ding, Junhui

2017-08-01

The aim of this report was to present the use of flow-through free fibula osteocutaneous flap for the repair of complex tibial bone, soft tissue, and main artery segmental defects. Five patients with bone, soft tissue, and segmental anterior tibial artery defects were included. The lengths of injured tibial bones ranged from 4 to 7 cm. The sizes of impaired soft tissues were between 9 × 4 and 15 × 6 cm. The lengths of defect of anterior tibial artery segments ranged from 6 to 10 cm. Two patients had distal limb perfusion problems. Flow-through free fibula osteocutaneous flap was performed for all 5 patients. Patients were followed for 12 to 18 months. All wounds healed after 1-stage operation, and all flow-through flaps survived. The distal perfusion after vascular repair was normal in all patients. Superficial necrosis of flap edge was noted in 1 case. After the local debridement and partial thickness skin graft, the flap healed uneventfully, and the surgical operation did not increase injury to the donor site. Satisfactory bone union was achieved in all patients in 2 to 4 months postoperation. Enlargement of fibula graft was observed during follow-up from 12 to 18 months. The functions of adjacent joints were recovered, and all patients were able to walk normally. Flow-through free fibula osteocutaneous flap was shown to be an effective and efficient technique for repairing composite tibial bone, soft tissue, and main artery segmental defects. This 1-stage operation should be useful in clinical practice for the treatment of complex bone, soft tissue, and vessel defects.

Segmental somatosensory-evoked potentials as a diagnostic tool in chronic inflammatory demyelinating polyneuropathies, and other sensory neuropathies.

PubMed

Koutlidis, R M; Ayrignac, X; Pradat, P-F; Le Forestier, N; Léger, J-M; Salachas, F; Maisonobe, T; Fournier, E; Viala, K

2014-09-01

Somatosensory-evoked potentials with segmental recordings were performed with the aim of distinguishing chronic inflammatory demyelinating polyneuropathy from other sensory neuropathies. Four groups of 20 subjects each corresponded to patients with (1) possible sensory chronic inflammatory demyelinating polyneuropathy, (2) patients with sensory polyneuropathy of unknown origin, (3) patients with amyotrophic lateral sclerosis and (4) normal subjects. The patients selected for this study had preserved sensory potentials on electroneuromyogram and all waves were recordable in evoked potentials. Somatosensory-evoked potentials evaluations were carried out by stimulation of the posterior tibial nerve at the ankle, recording peripheral nerve potential in the popliteal fossa, radicular potential and spinal potential at the L4-L5 and T12 levels, and cortical at C'z, with determination of distal conduction time, proximal and radicular conduction time and central conduction time. In the group of chronic inflammatory demyelinating polyneuropathy, 80% of patients had abnormal conduction in the N8-N22 segment and 95% had abnormal N18-N22 conduction time. In the group of neuropathies, distal conduction was abnormal in most cases, whereas 60% of patients had no proximal abnormality. None of the patients in the group of amyotrophic lateral sclerosis had an abnormal N18-N22 conduction time. Somatosensory-evoked potentials with segmental recording can be used to distinguish between atypical sensory chronic inflammatory demyelinating polyneuropathy and other sensory neuropathies, at the early stage of the disease. Graphical representation of segmental conduction times provides a rapid and accurate visualization of the profile of each patient. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Angiographic Evaluation of Feeding Arteries of Hepatocellular Carcinoma in the Caudate Lobe of the Liver

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

Miyayama, Shiro, E-mail: s-miyayama@fukui.saiseikai.or.jp; Yamashiro, Masashi; Hattori, Yuki

2011-12-15

Purpose: To evaluate the origins of feeders of hepatocellular carcinoma (HCC) in the caudate lobe (S1). Materials and Methods: Eighty-eight HCCs (mean diameter 21.4 mm) were treated by chemoembolization. The tumor-feeding caudate artery was confirmed when a tumor stain was demonstrated on angiogram and iodized oil was accumulated into the HCC and S1 on computed tomography (CT). The origins were divided into R{sub 1} (right proximal), R{sub 2} (right distal), L{sub 1} (left proximal), L{sub 2} (left distal), A (anterior segmental), P (posterior segmental), M (middle hepatic or medial segmental), Ph (proper hepatic), Ch (common hepatic), and Ex (extrahepatic). Themore » origins of feeders supplying HCCs in the Spiegel lobe (SP; n = 36), the paracaval portion (PC; n = 38), and the caudate process (CP; n = 14) were also analyzed. Results: One hundred sixteen feeders were identified: 11 (9.5%) arose from R{sub 1}; 21 (18.1%) arose from R{sub 2}; nine arose (0.9%) from L{sub 1}; 15 (12.9%) arose from L{sub 2}; 24 (20.7%) arose from A; 25 (21.6%) arose from P; seven (6.0%) arose from M; one (0.9%) arose from Ph; and three (2.6%) arose from Ex. HCCs in the SP and the PC were fed by feeders from both hepatic arteries (the ratios of right to left were 3:2 and 3:1, respectively), and HCCs in the CP were dominantly fed by feeders from the right hepatic artery. Conclusion: The caudate artery most frequently arises from the right hepatic artery, followed with almost equal frequency by the left hepatic, the anterior segmental, and the posterior segmental artery. The origins of the caudate arteries differ according to the subsegmental locations.« less

Segmental transport of Ca²⁺ and Mg²⁺ along the gastrointestinal tract.

PubMed

Lameris, Anke L; Nevalainen, Pasi I; Reijnen, Daphne; Simons, Ellen; Eygensteyn, Jelle; Monnens, Leo; Bindels, René J M; Hoenderop, Joost G J

2015-02-01

Calcium (Ca(2+)) and magnesium (Mg(2+)) ions are involved in many vital physiological functions. Since dietary intake is the only source of minerals for the body, intestinal absorption is essential for normal homeostatic levels. The aim of this study was to characterize the absorption of Ca(2+) as well as Mg(2+) along the gastrointestinal tract at a molecular and functional level. In both humans and mice the Ca(2+) channel transient receptor potential vanilloid subtype 6 (TRPV6) is expressed in the proximal intestinal segments, whereas Mg(2+) channel transient receptor potential melastatin subtype 6 (TRPM6) is expressed in the distal parts of the intestine. A method was established to measure the rate of Mg(2+) absorption from the intestine in a time-dependent manner by use of (25)Mg(2+). In addition, local absorption of Ca(2+) and Mg(2+) in different segments of the intestine of mice was determined by using surgically implanted intestinal cannulas. By these methods, it was demonstrated that intestinal absorption of Mg(2+) is regulated by dietary needs in a vitamin D-independent manner. Also, it was shown that at low luminal concentrations, favoring transcellular absorption, Ca(2+) transport mainly takes place in the proximal segments of the intestine, whereas Mg(2+) absorption predominantly occurs in the distal part of the gastrointestinal tract. Vitamin D treatment of mice increased serum Mg(2+) levels and 24-h urinary Mg(2+) excretion, but not intestinal absorption of (25)Mg(2+). Segmental cannulation of the intestine and time-dependent absorption studies using (25)Mg(2+) provide new ways to study intestinal Mg(2+) absorption. Copyright © 2015 the American Physiological Society.

The Molecular Mechanism of the Catalase-like Activity in Horseradish Peroxidase.

PubMed

Campomanes, Pablo; Rothlisberger, Ursula; Alfonso-Prieto, Mercedes; Rovira, Carme

2015-09-02

Horseradish peroxidase (HRP) is one of the most relevant peroxidase enzymes, used extensively in immunochemistry and biocatalysis applications. Unlike the closely related catalase enzymes, it exhibits a low activity to disproportionate hydrogen peroxide (H2O2). The origin of this disparity remains unknown due to the lack of atomistic information on the catalase-like reaction in HRP. Using QM(DFT)/MM metadynamics simulations, we uncover the mechanism for reduction of the HRP Compound I intermediate by H2O2 at atomic detail. The reaction begins with a hydrogen atom transfer, forming a peroxyl radical and a Compound II-like species. Reorientation of the peroxyl radical in the active site, concomitant with the transfer of the second hydrogen atom, is the rate-limiting step, with a computed free energy barrier (18.7 kcal/mol, ∼ 6 kcal/mol higher than the one obtained for catalase) in good agreement with experiments. Our simulations reveal the crucial role played by the distal pocket residues in accommodating H2O2, enabling formation of a Compound II-like intermediate, similar to catalases. However, out of the two pathways for Compound II reduction found in catalases, only one is operative in HRP. Moreover, the hydrogen bond network in the distal side of HRP compensates less efficiently than in catalases for the energetic cost required to reorient the peroxyl radical at the rate-determining step. The distal Arg and a water molecule in the "wet" active site of HRP have a substantial impact on the reaction barrier, compared to the "dry" active site in catalase. Therefore, the lower catalase-like efficiency of heme peroxidases compared to catalases can be directly attributed to the different distal pocket architecture, providing hints to engineer peroxidases with a higher rate of H2O2 disproportionation.

The role of T56 in controlling the flexibility of the distal histidine in dehaloperoxidase-hemoglobin from Amphitrite ornata.

PubMed

Jiang, Shu; Wright, Iain; Swartz, Paul; Franzen, Stefan

2013-10-01

The activation of dehaloperoxidase-hemoglobin (DHP) to form a ferryl intermediate requires the distal histidine, H55, to act as an acid base catalyst. The lack of ancillary amino acids in the distal pocket to assist in this process makes H55 even more important to the formation of active intermediates than in conventional peroxidases. Therefore, one can infer that the precise conformation H55 may greatly affect the enzymatic activity. Using site-direct mutagenesis at position T56, immediately adjacent to H55, we have confirmed that subtle changes in the conformation of H55 affect the catalytic efficiency of DHP. Mutating T56 to a smaller amino acid appears to permit H55 to rotate with relatively low barriers between conformations in the distal pocket, which may lead to an increase in catalytic activity. On the other hand, larger amino acids in the neighboring site appear to restrict the rotation of H55 due to the steric hindrance. In the case of T56V, which is an isosteric mutation, H55 appears less mobile, but forced to be closer to the heme iron than in wild type. Both proximity to the heme iron and flexibility of motion in some of the mutants can result in an increased catalytic rate, but can also lead to protein inactivation due to ligation of H55 to the heme iron, which is known as hemichrome formation. A balance of enzymatic rate and protein stability with respect to hemichrome formation appears to be optimum in wild type DHP (WT-DHP). Copyright © 2013 Elsevier B.V. All rights reserved.

AISLE: an automatic volumetric segmentation method for the study of lung allometry.

PubMed

Ren, Hongliang; Kazanzides, Peter

2011-01-01

We developed a fully automatic segmentation method for volumetric CT (computer tomography) datasets to support construction of a statistical atlas for the study of allometric laws of the lung. The proposed segmentation method, AISLE (Automated ITK-Snap based on Level-set), is based on the level-set implementation from an existing semi-automatic segmentation program, ITK-Snap. AISLE can segment the lung field without human interaction and provide intermediate graphical results as desired. The preliminary experimental results show that the proposed method can achieve accurate segmentation, in terms of volumetric overlap metric, by comparing with the ground-truth segmentation performed by a radiologist.

Sagittal and transversal plane deformity in thoracic scoliosis.

PubMed

Kotwicki, Tomasz

2002-01-01

The aim of the study was to assess the sagittal and transversal plane deformity of the spine in thoracic scoliosis by the mean of 3-D radiographic analysis. 46 patients admitted for surgery for thoracic idiopathic scoliosis underwent preoperative radiographic assessment. All patients presented the same pattern of the coronal plane deformity: single right thoracic curve (Lenke 1, King 3). Neither lumbar nor proximal thoracic structural curve were present. The Cobb angle varied from 41gamma to 77 gamma (mean 55,4 gamma +/- 8,6 gamma). Long cassette standing antero-posterior and lateral radiographs were analysed. Three-dimensional reconstruction with Rachis 91TM software was performed for each pair of radiographs. The following parameters were assessed: sagittal thoracic Cobb angle (Th4-Th12), upper thoracic kyphosis angle (Th5-Th8), lower thoracic kyphosis angle (Th9-Th12), superior and inferior hemi-curve sagittal angles, lumbar lordosis, sacral slope, sacral incidence, vertebral plate index, segmental vertebral axial rotation throughout the thoracic and lumbar spine. Results showed great variability of parameters assessed. The non-harmonious distribution of kyphosis was demonstrated in the thoracic spine. Local Th9-Th12 hypokyphosis and adjacent local Th5-Th8 hyperkyphosis constitute the most typical sagittal pathologies. So called normokyphotic curves were composed of one hyperkyphotic and one hypokyphotic zone. Th1-Th4 segment revealed two patterns of segmental rotation distribution: a purely compensatory curve with no vertebral axial rotation or a rotated curve presenting the morphology intermediate between Lenke 1 and Lenke 2 types (or King 3 and King 5). curves presenting the same coronal plane deformity differ in their morphology assessed in the two other planes; global thoracic kyphosis angle is a misleading parameter because it covers hypo- and hyperkyphotic zones; local distal thoracic (Th9-Th12) hypokyphosis is present in idiopathic thoracic scoliosis.

[Anatomy, physiology and clinical relevance of the connecting tubule].

PubMed

Miranda, N; Simeoni, M A; Ciriana, E; Panico, C; Cappello, E; Capasso, G B

2009-01-01

The cortical distal nephron is the site of fine regulation of salt and water excretion by peptide and mineralocorticoid hormones and the site for specific actions of diuretics. Some data suggest that sodium reabsorption and potassium secretion in the distal convoluted tubule and the connecting tubule (CNT) are sufficient to maintain the sodium and potassium balance, with little or no contribution of the collecting duct. The homeostatic role of the sodium and potassium transport systems in the collecting duct can be questioned, especially in conditions where dietary sodium intake is high and potassium intake is low compared with the physiological needs of the organism. The functional expression of epithelial sodium channels (ENaC) in the CNT is sufficient for furosemide-stimulated urinary acidification and identifies the CNT as a major segment in electrogenic urinary acidification. In the outer renal cortex, the CNT returns to the glomerular hilus and contacts the renal afferent arterioles (Af-Art). This morphology is compatible with a cross-talk between the CNT and Af-Art. This novel regulatory mechanism of the renal microcirculation may participate in the vasodilatation observed during high salt intake, perhaps by antagonizing tubuloglomerular feedback. In conclusion, the cortical distal nephron appears to be a complex site for several physiological mechanisms; it is mainly involved in salt and fluid homeostasis and in acid-base balance maintenance. Furthermore, the CNT segment appears to promote a CNT-Af-Art feedback loop.

Dietary sodium induces a redistribution of the tubular metabolic workload

PubMed Central

Udwan, Khalil; Abed, Ahmed; Roth, Isabelle; Dizin, Eva; Maillard, Marc; Bettoni, Carla; Loffing, Johannes; Wagner, Carsten A.; Edwards, Aurélie

2017-01-01

Key points Body Na+ content is tightly controlled by regulated urinary Na+ excretion.The intrarenal mechanisms mediating adaptation to variations in dietary Na+ intake are incompletely characterized.We confirmed and expanded observations in mice that variations in dietary Na+ intake do not alter the glomerular filtration rate but alter the total and cell‐surface expression of major Na+ transporters all along the kidney tubule.Low dietary Na+ intake increased Na+ reabsorption in the proximal tubule and decreased it in more distal kidney tubule segments.High dietary Na+ intake decreased Na+ reabsorption in the proximal tubule and increased it in distal segments with lower energetic efficiency.The abundance of apical transporters and Na+ delivery are the main determinants of Na+ reabsorption along the kidney tubule.Tubular O2 consumption and the efficiency of sodium reabsorption are dependent on sodium diet. Abstract Na+ excretion by the kidney varies according to dietary Na+ intake. We undertook a systematic study of the effects of dietary salt intake on glomerular filtration rate (GFR) and tubular Na+ reabsorption. We examined the renal adaptive response in mice subjected to 7 days of a low sodium diet (LSD) containing 0.01% Na+, a normal sodium diet (NSD) containing 0.18% Na+ and a moderately high sodium diet (HSD) containing 1.25% Na+. As expected, LSD did not alter measured GFR and increased the abundance of total and cell‐surface NHE3, NKCC2, NCC, α‐ENaC and cleaved γ‐ENaC compared to NSD. Mathematical modelling predicted that tubular Na+ reabsorption increased in the proximal tubule but decreased in the distal nephron because of diminished Na+ delivery. This prediction was confirmed by the natriuretic response to diuretics targeting the thick ascending limb, the distal convoluted tubule or the collecting system. On the other hand, HSD did not alter measured GFR but decreased the abundance of the aforementioned transporters compared to NSD. Mathematical modelling predicted that tubular Na+ reabsorption decreased in the proximal tubule but increased in distal segments with lower transport efficiency with respect to O2 consumption. This prediction was confirmed by the natriuretic response to diuretics. The activity of the metabolic sensor adenosine monophosphate‐activated protein kinase (AMPK) was related to the changes in tubular Na+ reabsorption. Our data show that fractional Na+ reabsorption is distributed differently according to dietary Na+ intake and induces changes in tubular O2 consumption and sodium transport efficiency. PMID:28940314

Application Of Three-Dimensional Videography To Human Motion Studies: Constraints, Assumptions, And Mathematics

NASA Astrophysics Data System (ADS)

Rab, George T.

1988-02-01

Three-dimensional human motion analysis has been used for complex kinematic description of abnormal gait in children with neuromuscular disease. Multiple skin markers estimate skeletal segment position, and a sorting and smoothing routine provides marker trajectories. The position and orientation of the moving skeleton in space are derived mathematically from the marker positions, and joint motions are calculated from the Eulerian transformation matrix between linked proximal and distal skeletal segments. Reproduceability has been excellent, and the technique has proven to be a useful adjunct to surgical planning.

Effect of multilevel lumbar disc arthroplasty on the operative- and adjacent-level kinematics and intradiscal pressures: an in vitro human cadaveric assessment.

PubMed

Dmitriev, Anton E; Gill, Norman W; Kuklo, Timothy R; Rosner, Michael K

2008-01-01

With lumbar arthroplasty gaining popularity, limited data are available highlighting changes in adjacent-level mechanics after multilevel procedures. Compare operative- and adjacent-segment range of motion (ROM) and intradiscal pressures (IDPs) after two-level arthroplasty versus circumferential arthrodesis. Cadaveric biomechanical study. Ten human cadaveric lumbar spines were used in this investigation. Biomechanical testing was performed according to a hybrid testing protocol using an unconstrained spine simulator under axial rotation (AR), flexion extension (FE), and lateral-bending (LB) loading. Specimens were tested in the following order: 1) Intact, 2) L3-L5 total disc replacement (TDR), 3) L3-L5 anterior interbody cages+pedicle screws. IDP was recorded at proximal and distal adjacent levels and normalized to controls (%intact). Full ROM was monitored at the operative and adjacent levels and reported in degrees. Kinematics assessment revealed L3-L5 ROM reduction after both reconstructions versus intact controls (p < .05). However, global quality of segmental motion distributed over L2-S1 was preserved in the arthroplasty group but was significantly altered after circumferential fixation. Furthermore, adjacent-level ROM was increased for the arthrodesis group under LB at both segments and during AR at L2-L3 relative to controls (p < .05). FE did not reveal any intergroup statistical differences. Nonetheless, after arthrodesis IDPs were increased proximally under all three loading modalities, whereas distally a significant IDP rise was noted during AR and LB (p < .05). No statistical differences in either biomechanical parameter were recorded at the adjacent levels between intact control and TDR groups. Our results indicate no significant adjacent-level biomechanical changes between arthroplasty and control groups. In contrast, significant alterations in ROM and IDP were recorded both proximally (ROM=LB & AR; IDP=AR, FE, LB) and distally (ROM=LB; IDP=AR & LB) after circumferential arthrodesis. Therefore, two-level lumbar arthroplasty maintains a more favorable biomechanical environment at the adjacent segments compared with the conventional transpedicular fixation technique. This, in turn, may have a positive effect on the rate of the transition syndrome postoperatively.

Partial monosomy Xq(Xq23 --> qter) and trisomy 4p(4p15.33 --> pter) in a woman with intractable focal epilepsy, borderline intellectual functioning, and dysmorphic features.

PubMed

Bartocci, Arnaldo; Striano, Pasquale; Mancardi, Maria Margherita; Fichera, Marco; Castiglia, Lucia; Galesi, Ornella; Michelucci, Roberto; Elia, Maurizio

2008-06-01

Studies of epilepsy associated with chromosomal abnormalities may provide information about clinical and EEG phenotypes and possibly to identify new epilepsy genes. We describe a female patient with intractable focal epilepsy, borderline intellectual functioning, and facial dysmorphisms, in whom genetic study (i.e., karyotype and array-CGH analysis) revealed a distal trisomy 4p and distal monosomy Xq. Although any genetic hypothesis remains speculative, several genes are located in the 4p chromosome segment involved in the rearrangement, some of which may be related to epilepsy.

14 CFR 97.3 - Symbols and terms used in procedures.

Code of Federal Regulations, 2010 CFR

2010-01-01

... established on the intermediate course or final approach course. (2) Initial approach altitude is the altitude (or altitudes, in high altitude procedure) prescribed for the initial approach segment of an...: Speed 166 knots or more. Approach procedure segments for which altitudes (minimum altitudes, unless...

14 CFR 97.3 - Symbols and terms used in procedures.

Code of Federal Regulations, 2011 CFR

2011-01-01

... established on the intermediate course or final approach course. (2) Initial approach altitude is the altitude (or altitudes, in high altitude procedure) prescribed for the initial approach segment of an...: Speed 166 knots or more. Approach procedure segments for which altitudes (minimum altitudes, unless...

Paracetamol absorption from different sites in the human small intestine.

PubMed Central

Gramatté, T; Richter, K

1994-01-01

Site-specificity in the small intestinal absorption of paracetamol was investigated using a segmental intestinal steady state perfusion technique (triple-lumen tubing system) combined with simultaneous measurements of serum drug concentrations. Dissolved paracetamol was perfused over 160 min into different parts of the small intestine (65-210 cm beyond the teeth). Each of the four healthy subjects was studied twice with a proximal and a more distal site of perfusion. Serum drug concentrations were similar after proximal and distal perfusions. Mean drug absorption rates calculated from intestinal aspirate concentrations were similar in both parts of the intestine--proximal: 869 micrograms 30 cm-1 min-1 (95% CI: 659-1079) vs distal: 941 micrograms 30 cm-1 min-1 (794-1088). The absorption rate was related directly to the amount of paracetamol perfused per unit time as well as to the rate of transmucosal water fluxes. PMID:7917782

Modified single stapler technique in anterior resection for rectal cancer.

PubMed

Akbaba, Soner; Ersoy, Pamir Eren; Gundogdu, Riza Haldun; Ulas, Murat; Menekse, Ebru

2015-01-01

Technical difficulties during colorectal surgery increase the complication rates. We introduce a modified single stapler technique for patients in whom technical problems are encountered while performing double stapler technique. Before pelvic dissection, descending colon is divided at minimum 10 cm proximal to the tumoral segment. Tumor specific mesorectal excision is performed and two purse string sutures are placed at the distal margin with an interval of 1 - 2 cm. After introducing a circular stapler via the anus, the distal purse string suture is tied around the central shaft of the stapler and the proximal purse string suture around the colonic lumen. After the resection is completed between the two sutures, the anvil shaft is connected to the central shaft and the stapler is closed and fired. None of the patients had an anastomotic leak. This technique may be a safe alternative particularly in patients with narrow pelvis and distal tumors.

Changes in the structural properties of peripheral nerves after transection.

PubMed

Toby, E B; Meyer, B M; Schwappach, J; Alvine, G

1996-11-01

Changes in peripheral nerve structural properties after transection were measured weekly for 5 weeks in the distal stump of the sciatic nerve in 50 Sprague-Dawley rats. Each week after transection, the distal stump of the transected nerve showed increased stiffness when compared to intact nerves. Linear elastic stiffness reached a maximum at weeks 1 and 2 after transection, when the transected nerves were 15% stiffer than the contralateral control sides. Toughness was also increased and reached a maximum at week 4 with a 50% difference between values for experimental and control sides. Overall failure load was between 21% and 27% greater, peaking at week 3. An increase in stiffness of the distal stump would result in increased tension at the suture line, as the nerve gap is overcome when performing a delayed neurorraphy. These data suggest, with respect to structural properties, that an end-to-end repair should be carried out at the time of injury; after only 1 week, significant stiffness in the distal segment of the nerve developed, which should result in an increase in tension at the repair site.

Laparoscopic diagnosis of retrograde peristalsis and intussusception in Roux-en-Y limb after laparoscopic gastrectomy: A case report.

PubMed

Yoshiyama, Shigeyuki; Toiyama, Yuji; Ichikawa, Takashi; Shimura, Tadanobu; Yasuda, Hiromi; Hiro, Jun-Ichiro; Ohi, Masaki; Araki, Toshimitsu; Kusunoki, Masato

2018-06-05

The cause of jejunojejunal intussusception, a rare complication after Roux-en-Y gastric surgery, remains unclear. Here, we present a case of retrograde jejunojejunal intussusception that occurred after laparoscopic distal gastrectomy with Roux-en-Y reconstruction. A 51-year-old woman who had undergone laparoscopic distal gastrectomy and Roux-en-Y reconstruction for early gastric cancer 6 years previously was admitted to our hospital with abdominal pain. Abdominal CT revealed the "target sign," and she was diagnosed as having small bowel intussusception. Laparoscopic surgery resulted in a diagnosis of retrograde intussusception of the distal jejunum of the Roux-en-Y anastomosis with retrograde peristalsis in the same area. The Roux-en-Y anastomosis site and intussuscepted segment were resected laparoscopically. To the best of our knowledge, this is the first report of laparoscopic diagnosis of retrograde peristalsis in the distal jejunum of a Roux-en-Y anastomosis. Additionally, relevant published reports concerning this unusual condition are discussed. © 2018 Japan Society for Endoscopic Surgery, Asia Endosurgery Task Force and John Wiley & Sons Australia, Ltd.

Evolution of fine scale segmentation at intermediate ridges: example of Alarcon Rise and Endeavour Segment.

NASA Astrophysics Data System (ADS)

Le Saout, M.; Clague, D. A.; Paduan, J. B.; Caress, D. W.

2016-12-01

Mid-ocean ridges are marked by a segmentation of the axis and underlying magmatic system. Fine-scale segmentation is mainly studied along fast spreading ridges. Here we analyze the evolution of the 3rd and 4th order segmentation along two intermediate spreading centers, characterized by contrasting morphologies. Alarcon Rise, with a full spreading rate of 49 mm/yr, is characterized by an axial high and a relatively narrow axial summit trough. Endeavour segment has a spreading rate of 52.5 mm/yr and is represented by a wide axial valley affected by numerous faults. These two ridges are characterized by high and low volcanic periods, respectively. The segmentation is analyzed using high-resolution bathymetric cross-sections perpendicular to the axes. These profiles are 1200-m-long for Alarcon Rise and 2400-m-long at Endeavour Segment and are 100 m apart. The discontinuity order is based on variations, from either side of each offset, in: 1/the geometry and orientation of the axial summit trough or graben 2/ the lava morphology, and 3/ the distribution of hydrothermal vents. Alarcon Rise is marked by a recent southeast jump in volcanic activity. The comparison between actual and previous segmentation reveals a rapid evolution of the 3rd order segmentation in the most active part of the ridge, with a lengthening of the central 3rd segment of 8 km over 3-4 ky. However, no relation is observed in the 4th order segmentation before and after the axis jump. Along Endeavour, traces of the previous 3rd order discontinuities are still perceptible on the walls of the graben. This 3rd order segmentation has persisted at least during the last 4.5 ky. Indeed, it is visible in the distribution of the recent hydrothermal vents observed in the axial valley as well as in the segmentation of the axial magma lens. Analysis of the two ridges suggests that small-scale segmentation varies primarily during high magmatic phases.

Parental Cognitive Impairment, Mental Health, and Child Outcomes in a Child Protection Population

ERIC Educational Resources Information Center

Feldman, Maurice; McConnell, David; Aunos, Marjorie

2012-01-01

Parents with cognitive impairments (CI) are overrepresented in child custody cases and their children are at risk for adverse outcomes. Ecological-transactional researchers propose that child outcomes are a function of the interaction of multiple distal, intermediate, and proximal risk and resilience factors. This study tested the fit of, and…

The relationship between age, rotator cuff integrity, and osseous microarchitecture of greater tuberosity: Where should we put anchor?

PubMed

Kholinne, Erica; Lee, Hyun Joo; Kim, Sung Jung; Park, So Hyun; Jeon, In-Ho

2018-01-01

The aim of this study was to compare the microarchitecture of the greater tuberosity with or without rotator cuff tear and to obtain optimum location for anchor screw insertion for rotator cuff repair. Twenty-five humeral heads were harvested from 13 male cadavers of mean age 58.4 years, including 6 humeri with rotator cuff tear and 19 intact humeri. Six regions of interest (proximal, intermediate, and distal zones of the superficial and deep regions) were divided into the anterior (G1), middle (G2), and posterior (G3) areas of the greater tuberosity. Trabecular bone volume and cortical thickness were evaluated. Total trabecular bone volume was greater in subjects <50 years old than in subjects >50 years old but did not differ significantly in subjects with and without rotator cuff tear. Cortical thickness in both intact and torn rotator cuff groups was significantly greater in the proximal and intermediate zones than in the distal zone. Cortical thickness was related to anatomic location rather than age or cuff tear. The optimal location for anchor screw insertion during rotator cuff repair is either the proximal or intermediate region of the greater tuberosity. Age has more influence in terms of trabecular bone volume loss than rotator cuff integrity. Copyright © 2017. Production and hosting by Elsevier B.V.

Spinal Ischemia in Thoracic Aortic Procedures: Impact of Radiculomedullary Artery Distribution.

PubMed

Kari, Fabian A; Wittmann, Karin; Krause, Sonja; Saravi, Babak; Puttfarcken, Luisa; Förster, Katharina; Rylski, Bartosz; Maier, Sven; Göbel, Ulrich; Siepe, Matthias; Czerny, Martin; Beyersdorf, Friedhelm

2017-12-01

The aim of this study was to assess the influence of thoracic anterior radiculomedullary artery (tARMA) distribution on spinal cord perfusion in a thoracic aortic surgical model. Twenty-six pigs (34 ± 3 kg; study group, n = 20; sham group, n = 6) underwent ligation of the left subclavian artery and thoracic segmental arteries. End points were spinal cord perfusion pressure (SCPP), regional spinal cord blood flow (SCBF), and neurologic outcome with an observation time of 3 hours. tARMA distribution patterns tested for an effect on end points included (1) maximum distance between any 2 tARMAs within the treated aortic segment (0 or 1 segment = small-distance group; >1 segment = large-distance group) and (2) distance between the end of the treated aortic segment and the first distal tARMA (at the level of the distal simulated stent-graft end = group 0; gap of 1 or more segments = group ≥1). The number of tARMA ranged from 3 to 13 (mean, 8). In the large-distance group, SCBF dropped from 0.48 ± 0.16 mL/g/min to 0.3 ± 0.08 mL/g/min (p < 0.001). We observed no detectable SCBF drop in the small-distance group: 0.2 ± 0.05 mL/g/min at baseline to 0.23 ± 0.05 mL/g/min immediately after clamping (p = 0.147). SCBF increased from 0.201 ± 0.055 mL/g/min at baseline to 0.443 ± 0.051 mL/g/min at 3 hours postoperatively (p < 0.001) only in the small-distance group. We demonstrate experimental data showing that distribution patterns of tARMAs correlate with the degree of SCBF drop and insufficient reactive parenchymal hyperemia in aortic procedures. Individual ARMA distribution patterns along the treated aortic segment could help us predict the individual risk of spinal ischemia. Copyright © 2017 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

Pooled-BAC sequencing of a black pod resistance region (cBPQTL12) in T. cacao

USDA-ARS?s Scientific Manuscript database

Whole genome sequencing (WGS) is an expensive and technically challenging endeavor. An alternative to WGS is to sequence specific chromosomal segments of biological interest (e.g. a QTL interval). This method is cheaper than WGS and reduces the risk of misassembly from distal parts of the genome. Us...

Androgen-dependent and independent process of bone formation in the distal segment of Os penis in the rat.

PubMed

Murakami, R; Izumi, K; Yamaoka, I

1995-11-01

The distal segment of the os penis of the rat develops as a fibrocartilage which is replaced with non-lamellar bone by endochondral ossification after puberty. Development of the fibrocartilage and its calcification have been shown to be induced by androgens, but androgen-dependency of the endochondral ossification has not been studied in detail. In the present study, immature male rats of various ages were castrated and the ossification of the fibrocartilage of os penis was examined. In rats castrated at 6 weeks, when the fibrocartilage was scarcely calcified, ossification did not occur even at 24 weeks. When the castrated rats were treated with testosterone, ossification started before 12 weeks of age. In rats castrated at 8 weeks, when the fibrocartilage was heavily calcified, endochondral ossification was observed in some of the animals (5/7) at 24 weeks of age. The results of this study indicate that once the fibrocartilage is calcified, the endochondral ossification can take place without androgen, although the androgen can promote the process of ossification.

Three distal anterior cerebral artery aneurysms in the same branch associated with five additional intracranial aneurysms

PubMed Central

Kozyrev, Danil A.; Jahromi, Behnam Rezai; Thiarawat, Peeraphong; Choque-Velasquez, Joham; Ludtka, Christopher; Goehre, Felix; Hernesniemi, Juha

2017-01-01

Background: Multiple distal anterior cerebral artery (DACA) aneurysms appear as rare findings. Simultaneous treatment of such lesions can be particularly challenging. A report of three aneurysms on the same parent artery has not been reported before. We report a case of three DACA aneurysms treated within one microsurgical operation in a patient with eight aneurysms. Case Description: A 62-year-old woman incidentally presented with multiple various size saccular aneurysms, including tree on the left DACA. One of the DACA aneurysm was located on the A3 segment, and the other two were on the A4 and A5 segments. Ligation of all three of these aneurysms was planned in one operation. A standard anterior interhemispheric approach was utilized. Three aneurysms were successfully clipped using four clips. Intraoperative angiography confirmed aneurysm occlusion with parent artery patency preservation. The patient showed no new postoperative neurological deficit. Conclusion: Clipping multiple DACA aneurysms within a single microneurosurgical operation is a feasible treatment option. Meticulous analysis of preoperative imaging features is crucial for selecting the best, patient-specific treatment strategy. PMID:28540128

Sonographic and electrodiagnostic features of hereditary neuropathy with liability to pressure palsies.

PubMed

Ginanneschi, Federica; Filippou, Georgios; Giannini, Fabio; Carluccio, Maria A; Adinolfi, Antonella; Frediani, Bruno; Dotti, Maria T; Rossi, Alessandro

2012-12-01

In hereditary neuropathy with liability to pressure palsies (HNPP), the increase in distal motor latencies (DMLs) is often out of proportion to the slowing of conduction velocities, but the pathophysiological mechanism is still unclear. We used a combined electrophysiological and ultrasonographic (US) approach to provide insight into this issue. Twelve HNPP subjects underwent extensive electrophysiological studies and US measurements of the cross-sectional area (CSA) of several peripheral nerves. US nerve enlargement was only observed in the carpal tunnel, Guyon's canal, the elbow and the fibular head. We did not observe US abnormalities at sites where nerve entrapment is uncommon. An increase in DMLs was observed regardless of US nerve enlargement. The increased nerve CSA only in common sites of entrapment likely reflected the well-documented nerve vulnerability to mechanical stress in HNPP. No morphometric changes were seen in the distal nerve segments where compression/entrapment is unlikely, despite the fact that the DMLs were increased. These data suggest that factors other than mechanical stress are responsible for the distal slowing of action potential propagation. We speculate that a mixture of mechanical insults and an axon-initiated process in the distal nerves underlies the distal slowing and/or conduction failure in HNPP. © 2012 Peripheral Nerve Society.

An unusual colon atresia in a calf: at the junction of the distal loop and transverse colon. A brief overview

PubMed Central

Lombardero, Matilde; Yllera, María del Mar

2014-01-01

Congenital defects are those abnormalities present at birth. During embryogenesis, many anomalies can occur. The primitive gut tube lengthens quickly and rotates, allowing the gastrointestinal tract acquire its final position and orientation. Because the colon of large animals is complex, most changes occur in this segment. Thus, in ruminants, colon atresia is the most frequent malformation, affecting mainly ascending colon, at the level of the spiral loop. There are no previous references about a very atypical colon atresia at the junction of distal loop and transverse colon, such we have described in a 5-day-old calf, after a history of abdominal distention and absence of feces at birth, even with a patent anal opening. Atresia coli was detected at distal position of the typical colon atresia, at the junction of distal loop and transverse colon. In addition, the distal blind end was bent into a U-shape supported by the mesocolon. Besides the anatomical findings of this worthwhile atresia coli we discuss its possible etiology, in which local factors, such as a compromised blood supply during embryogenesis, are more consistent than genetic factors. Finding out the causes of atresia coli would help to reduce its incidence, lessen animal suffering and economic loss. PMID:25495264

Angiogenic imbalance and diminished matrix metalloproteinase-2 and -9 underlie regional decreases in uteroplacental vascularization and feto-placental growth in hypertensive pregnancy.

PubMed

Dias-Junior, Carlos A; Chen, Juanjuan; Cui, Ning; Chiang, Charles L; Zhu, Minglin; Ren, Zongli; Possomato-Vieira, Jose S; Khalil, Raouf A

2017-12-15

Preeclampsia is a form of hypertension-in-pregnancy (HTN-Preg) with unclear mechanism. Generalized reduction of uterine perfusion pressure (RUPP) could be an initiating event leading to uteroplacental ischemia, angiogenic imbalance, and HTN-Preg. Additional regional differences in uteroplacental blood flow could further affect the pregnancy outcome and increase the risk of preeclampsia in twin or multiple pregnancy, but the mechanisms involved are unclear. To test the hypothesis that regional differences in angiogenic balance and matrix metalloproteinases (MMPs) underlie regional uteroplacental vascularization and feto-placental development, we compared fetal and placental growth, and placental and myoendometrial vascularization in the proximal, middle and distal regions of the uterus (in relation to the iliac bifurcation) in normal pregnant (Preg) and RUPP rats. Maternal blood pressure and plasma anti-angiogenic soluble fms-like tyrosine kinase-1 (sFlt-1)/placenta growth factor (PIGF) ratio were higher, and average placentae number, placenta weight, litter size, and pup weight were less in RUPP than Preg rats. The placenta and pup number and weight were reduced, while the number and diameter of placental and adjacent myoendometrial arteries, and MMP-2 and MMP-9 levels/activity were increased, and sFlt-1/PlGF ratio was decreased in distal vs proximal uterus of Preg rats. In RUPP rats, the placenta and pup number and weight, the number and diameter of placental and myoendometrial arteries, and MMP-2 and -9 levels/activity were decreased, and sFlt-1/PlGF ratio was increased in distal vs proximal uterus. Treatment with sFlt-1 or RUPP placenta extract decreased MMP-2 and MMP-9 in distal segments of Preg uterus, and treatment with PIGF or Preg placenta extract restored MMP levels in distal segments of RUPP uterus. Thus, in addition to the general reduction in placental and fetal growth during uteroplacental ischemia, localized angiogenic imbalance and diminished MMP-2 and MMP-9 could cause further decrease in placental and myoendometrial vascularization and placental and fetal growth in distal vs proximal uterus of HTN-Preg rats. Regional differences in uteroplacental perfusion, angiogenic balance and MMPs could be a factor in the incidence of preeclampsia in multiple pregnancy. Copyright © 2017 Elsevier Inc. All rights reserved.

Isolating the segment of the mitochondrial electron transport chain responsible for mitochondrial damage during cardiac ischemia

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

Chen, Qun; Yin, Guotian; Stewart, Sarah

2010-07-09

Ischemia damages the mitochondrial electron transport chain (ETC), mediated in part by damage generated by the mitochondria themselves. Mitochondrial damage resulting from ischemia, in turn, leads to cardiac injury during reperfusion. The goal of the present study was to localize the segment of the ETC that produces the ischemic mitochondrial damage. We tested if blockade of the proximal ETC at complex I differed from blockade distal in the chain at cytochrome oxidase. Isolated rabbit hearts were perfused for 15 min followed by 30 min stop-flow ischemia at 37 {sup o}C. Amobarbital (2.5 mM) or azide (5 mM) was used tomore » block proximal (complex I) or distal (cytochrome oxidase) sites in the ETC. Time control hearts were buffer-perfused for 45 min. Subsarcolemmal mitochondria (SSM) and interfibrillar mitochondria (IFM) were isolated. Ischemia decreased cytochrome c content in SSM but not in IFM compared to time control. Blockade of electron transport at complex I preserved the cytochrome c content in SSM. In contrast, blockade of electron transport at cytochrome oxidase with azide did not retain cytochrome c in SSM during ischemia. Since blockade of electron transport at complex III also prevented cytochrome c loss during ischemia, the specific site that elicits mitochondrial damage during ischemia is likely located in the segment between complex III and cytochrome oxidase.« less

Upper body contributions to power generation during rapid, overhand throwing in humans.

PubMed

Roach, Neil T; Lieberman, Daniel E

2014-06-15

High-speed and accurate throwing is a distinctive human behavior. Achieving fast projectile speeds during throwing requires a combination of elastic energy storage at the shoulder, as well as the transfer of kinetic energy from proximal body segments to distal segments. However, the biomechanical bases of these mechanisms are not completely understood. We used inverse dynamics analyses of kinematic data from 20 baseball players fitted with four different braces that inhibit specific motions to test a model of power generation at key joints during the throwing motion. We found that most of the work produced during throwing is generated at the hips, and much of this work (combined with smaller contributions from the pectoralis major) is used to load elastic elements in the shoulder and power the rapid acceleration of the projectile. Despite rapid angular velocities at the elbow and wrist, the restrictions confirm that much of the power generated to produce these distal movements comes from larger proximal segments, such as the shoulder and torso. Wrist hyperextension enhances performance only modestly. Together, our data also suggest that heavy reliance on elastic energy storage may help explain some common throwing injuries and can provide further insight into the evolution of the upper body and when our ancestors first developed the ability to produce high-speed throws. © 2014. Published by The Company of Biologists Ltd.

The impact of distal embolization and distal protection on long-term outcome in patients with ST elevation myocardial infarction randomized to primary percutaneous coronary intervention--results from a randomized study.

PubMed

Lønborg, Jacob; Kelbæk, Henning; Helqvist, Steffen; Holmvang, Lene; Jørgensen, Erik; Saunamäki, Kari; Kløvgaard, Lene; Kaltoft, Anne; Bøtker, Hans Erik; Lassen, Jens F; Thuesen, Leif; Terkelsen, Christian Juhl; Kofoed, Klaus Fuglsang; Clemmensen, Peter; Køber, Lars; Engstrøm, Thomas

2015-04-01

The impact of angiographically visible distal embolization (DE) and distal protection occurring during primary percutaneous coronary intervention (PCI) on long-term outcome has not been studied in a contemporary ST-segment elevation myocardial infarction (STEMI) cohort. To evaluate the association between DE and long-term outcome in STEMI patients treated with primary PCI with or without distal protection. In this post-hoc analysis of a randomized study, 591 STEMI patients were randomized to conventional primary PCI or primary PCI with distal protection and followed for 5 years. There was no statistically significant difference in MACE rate between patients treated with or wthout distal protection (19% versus 25%; p=0.10). There seemed to be interaction between distal protection and DE in major adverse cardiac events (MACE) (p=0.08), mortality (p=0.02) and reinfarction (p=0.06), but not admission for heart failure (p=0.40). DE was related to increased risk of admission for heart failure independently of distal protection (12.0% versus 5.0; p=0.015). The MACE rate for patients treated with standard PCI with DE was 31.3% compared to 24.8% for patients without DE (p=0.30), and 44.4% for patients treated with distal protection with DE compared to 17.9% for patients without DE (p=0.005). DE was not related to mortality (p=0.52) or reinfarction (p=0.52) among patients treated with standard PCI, but was related to higher rates of mortality (p=0.012) and reinfarction (p=0.008) when distal protection was used. DE occurred in 11% of STEMI patients treated with conventional primary PCI, and was associated with increased risk of development of heart failure. Distal protection did not improve the 5-years MACE rate, and might even aggravate the prognosis following DE, but this should only be considered hypothesis-generating. © The European Society of Cardiology 2014.

Seal assembly for materials with different coefficients of thermal expansion

DOEpatents

Minford, Eric [Laurys Station, PA

2009-09-01

Seal assembly comprising (a) two or more seal elements, each element having having a coefficient of thermal expansion; and (b) a clamping element having a first segment, a second segment, and a connecting segment between and attached to the first and second segments, wherein the two or more seal elements are disposed between the first and second segments of the clamping element. The connecting segment has a central portion extending between the first segment of the clamping element and the second segment of the clamping element, and the connecting segment is made of a material having a coefficient of thermal expansion. The coefficient of thermal expansion of the material of the connecting segment is intermediate the largest and smallest of the coefficients of thermal expansion of the materials of the two or more seal elements.

Ectrodactyly and proximal/intermediate interstitial deletion 7q

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

McElveen, C.; Carvajal, M.V.; Moscatello, D.

1995-03-13

We report on an individual with severe mental retardation, seizures, microcephaly, unusual face, scoliosis, and cleft feet and cleft right hand. The chromosomal study showed a proximal interstitial deletion 7q (q11.23q22). From our review of the literature, 11 patients have been reported with ectrodactyly (split hand/split foot malformation) and proximal/intermediate interstitial deletions or rearrangements of 7q. The critical segment for ectrodactyly seems to be located between 7q21.2 and 7q22.1. This malformation is present in 41% of the patients whose deletion involves the critical segment. 37 refs., 3 figs., 1 tab.

Comparison of CT angiography with conventional arterial angiography in aortoiliac occlusive disease.

PubMed

Tins, B; Oxtoby, J; Patel, S

2001-03-01

This study compared the results of conventional and CT angiography of the aortoiliac segment in 35 patients with occlusive disease. Disease severity was graded into five categories. Two assessors independently assessed the segment from the distal abdominal aorta to the proximal superficial femoral artery and a consensus was formed. There was interobserver agreement in 87% of segments for conventional angiography and in 78% for CT angiography. Comparison of the two modalities gave identical grading in 84% of segments. Dissimilar grading was found in 16%, with a roughly equal number of undergrading and overgrading. CT angiography has the advantages of being minimally invasive, requiring only an intravenous injection of contrast medium and imaging surrounding soft tissues. Multiplanar reconstruction aids the visualization of asymmetrical stenoses, and collateral blood supply is readily appreciated. However, CT angiography may fail to demonstrate short stenoses owing to limited z-axis resolution.

Variable Bone Density of Scaphoid: Importance of Subchondral Screw Placement.

PubMed

Swanstrom, Morgan M; Morse, Kyle W; Lipman, Joseph D; Hearns, Krystle A; Carlson, Michelle G

2018-02-01

Background  Ideal internal fixation of the scaphoid relies on adequate bone stock for screw purchase; so, knowledge of regional bone density of the scaphoid is crucial. Questions/Purpose  The purpose of this study was to evaluate regional variations in scaphoid bone density. Materials and Methods  Three-dimensional CT models of fractured scaphoids were created and sectioned into proximal/distal segments and then into quadrants (volar/dorsal/radial/ulnar). Concentric shells in the proximal and distal pole were constructed in 2-mm increments moving from exterior to interior. Bone density was measured in Hounsfield units (HU). Results  Bone density of the distal scaphoid (453.2 ± 70.8 HU) was less than the proximal scaphoid (619.8 ± 124.2 HU). There was no difference in bone density between the four quadrants in either pole. In both the poles, the first subchondral shell was the densest. In both the proximal and distal poles, bone density decreased significantly in all three deeper shells. Conclusion  The proximal scaphoid had a greater density than the distal scaphoid. Within the poles, there was no difference in bone density between the quadrants. The subchondral 2-mm shell had the greatest density. Bone density dropped off significantly between the first and second shell in both the proximal and distal scaphoids. Clinical Relevance  In scaphoid fracture ORIF, optimal screw placement engages the subchondral 2-mm shell, especially in the distal pole, which has an overall lower bone density, and the second shell has only two-third the density of the first shell.

Requirement of multiple cis-acting elements in the human cytomegalovirus major immediate-early distal enhancer for viral gene expression and replication.

PubMed

Meier, Jeffery L; Keller, Michael J; McCoy, James J

2002-01-01

We have shown previously that the human cytomegalovirus (HCMV) major immediate-early (MIE) distal enhancer is needed for MIE promoter-dependent transcription and viral replication at low multiplicities of infection (MOI). To understand how this region works, we constructed and analyzed a series of HCMVs with various distal enhancer mutations. We show that the distal enhancer is composed of at least two parts that function independently to coordinately activate MIE promoter-dependent transcription and viral replication. One such part is contained in a 47-bp segment that has consensus binding sites for CREB/ATF, SP1, and YY1. At low MOI, these working parts likely function in cis to directly activate MIE gene expression, thus allowing viral replication to ensue. Three findings support the view that these working parts are likely cis-acting elements. (i) Deletion of either part of a bisegmented distal enhancer only slightly alters MIE gene transcription and viral replication. (ii) Reversing the distal enhancer's orientation largely preserves MIE gene transcription and viral replication. (iii) Placement of stop codons at -300 or -345 in all reading frames does not impair MIE gene transcription and viral replication. Lastly, we show that these working parts are dispensable at high MOI, partly because of compensatory stimulation of MIE promoter activity and viral replication that is induced by a virion-associated component(s) present at a high viral particle/cell ratio. We conclude that the distal enhancer is a complex multicomponent cis-acting region that is required to augment both MIE promoter-dependent transcription and HCMV replication.

"Palmar pivot flap" for resurfacing palmar lateral defects of the fingers.

PubMed

Yam, Andrew; Peng, Yeong-Pin; Pho, Robert Wan-Heng

2008-12-01

Soft tissue defects on the lateral borders of the digits are difficult to reconstruct using local or local-regional flaps. We describe a "palmar pivot flap" to resurface an adjacent defect on the palmar-lateral aspect of the digit. The surgical technique is described. This flap is an axial pattern flap based on the subcutaneous transverse branches of the digital artery. The flap is pivoted up to 90 degrees on the neurovascular bundle in its base, into an adjacent defect. The flap can be raised from either the proximal or the middle phalangeal segments. It can cover defects sited from the level of the proximal interphalangeal joint up to the fingertip. The donor defect is limited to the same digit and is covered with a full-thickness skin graft. We have used this flap on 3 patients with defects at the middle phalangeal segment, the distal interphalangeal joint, and the fingertip. All healed primarily. One patient had a mild flexion contracture of the proximal interphalangeal joint, whereas the other 2 had no complications. The patients with distal interphalangeal joint and fingertip defects had excellent sensation in the flap (2-point discrimination of 5-6 mm). The palmar pivot flap is useful for resurfacing otherwise difficult defects on the lateral borders of the digits around and distal to the proximal interphalangeal joint, including those at the fingertip. It provides sensate, glabrous skin. The donor defect is on the same digit and is well hidden, producing an aesthetic and functional reconstruction.

Effects of hyperglycemia on rat cavernous nerve axons: a functional and ultrastructural study.

PubMed

Zotova, Elena G; Schaumburg, Herbert H; Raine, Cedric S; Cannella, Barbara; Tar, Moses; Melman, Arnold; Arezzo, Joseph C

2008-10-01

The present study explored parallel changes in the physiology and structure of myelinated (Adelta) and unmyelinated (C) small diameter axons in the cavernous nerve of rats associated with streptozotocin-induced hyperglycemia. Damage to these axons is thought to play a key role in diabetic autonomic neuropathy and erectile dysfunction, but their pathophysiology has been poorly studied. Velocities in slow conducting fibers were measured by applying multiple unit procedures; histopathology was evaluated with both light and electron microscopy. To our knowledge, these are the initial studies of slow nerve conduction velocities in the distal segments of the cavernous nerve. We report that hyperglycemia is associated with a substantial reduction in the amplitude of the slow conducting response, as well as a slowing of velocities within this very slow range (< 2.5 m/s). Even with prolonged hyperglycemia (> 4 months), histopathological abnormalities were mild and limited to the distal segments of the cavernous nerve. Structural findings included dystrophic changes in nerve terminals, abnormal accumulations of glycogen granules in unmyelinated and preterminal axons, and necrosis of scattered smooth muscle fibers. The onset of slowing of velocity in the distal cavernous nerve occurred subsequent to slowing in somatic nerves in the same rats. The functional changes in the cavernous nerve anticipated and exceeded the axonal degeneration detected by morphology. The physiologic techniques outlined in these studies are feasible in most electrophysiologic laboratories and could substantially enhance our sensitivity to the onset and progression of small fiber diabetic neuropathy.

EFFECTS OF HYPERGLYCEMIA ON RAT CAVERNOUS NERVE AXONS: A FUNCTIONAL AND ULTRASTRUCTURAL STUDY

PubMed Central

Zotova, Elena G.; Schaumburg, Herbert H.; Raine, Cedric S.; Cannella, Barbara; Tar, Moses; Melman, Arnold; Arezzo, Joseph C.

2008-01-01

The present study explored parallel changes in the physiology and structure of myelinated (Aδ) and unmyelinated (C) small diameter axons in the cavernous nerve of rats associated with streptozotocin-induced hyperglycemia. Damage to these axons is thought to play a key role in diabetic autonomic neuropathy and erectile dysfunction, but their pathophysiology has been poorly studied. Velocities in slow conducting fibers were measured by applying multiple unit procedures; histopathology was evaluated with both light and electron microscopy. To our knowledge, these are the initial studies of slow nerve conduction velocities in the distal segments of the cavernous nerve. We report that hyperglycemia is associated with a substantial reduction in the amplitude of the slow conducting response, as well as a slowing of velocities within this very slow range (<2.5 m/sec). Even with prolonged hyperglycemia (> 4 months), histopathological abnormalities were mild and limited to the distal segments of the cavernous nerve. Structural findings included dystrophic changes in nerve terminals, abnormal accumulations of glycogen granules in unmyelinated and preterminal axons, and necrosis of scattered smooth muscle fibers. The onset of slowing of velocity in the distal cavernous nerve occurred subsequent to slowing in somatic nerves in the same rats. The functional changes in the cavernous nerve anticipated and exceeded the axonal degeneration detected by morphology. The physiologic techniques outlined in these studies are feasible in most electrophysiologic laboratories and could substantially enhance our sensitivity to the onset and progression of small fiber diabetic neuropathy. PMID:18687329

The sodium chloride cotransporter (NCC) and epithelial sodium channel (ENaC) associate.

PubMed

Mistry, Abinash C; Wynne, Brandi M; Yu, Ling; Tomilin, Viktor; Yue, Qiang; Zhou, Yiqun; Al-Khalili, Otor; Mallick, Rickta; Cai, Hui; Alli, Abdel A; Ko, Benjamin; Mattheyses, Alexa; Bao, Hui-Fang; Pochynyuk, Oleh; Theilig, Franziska; Eaton, Douglas C; Hoover, Robert S

2016-10-01

The thiazide-sensitive sodium chloride cotransporter (NCC) and the epithelial sodium channel (ENaC) are two of the most important determinants of salt balance and thus systemic blood pressure. Abnormalities in either result in profound changes in blood pressure. There is one segment of the nephron where these two sodium transporters are coexpressed, the second part of the distal convoluted tubule. This is a key part of the aldosterone-sensitive distal nephron, the final regulator of salt handling in the kidney. Aldosterone is the key hormonal regulator for both of these proteins. Despite these shared regulators and coexpression in a key nephron segment, associations between these proteins have not been investigated. After confirming apical localization of these proteins, we demonstrated the presence of functional transport proteins and native association by blue native PAGE. Extensive coimmunoprecipitation experiments demonstrated a consistent interaction of NCC with α- and γ-ENaC. Mammalian two-hybrid studies demonstrated direct binding of NCC to ENaC subunits. Fluorescence resonance energy transfer and immunogold EM studies confirmed that these transport proteins are within appropriate proximity for direct binding. Additionally, we demonstrate that there are functional consequences of this interaction, with inhibition of NCC affecting the function of ENaC. This novel finding of an association between ENaC and NCC could alter our understanding of salt transport in the distal tubule. © 2016 The Author(s); published by Portland Press Limited on behalf of the Biochemical Society.

Diets high in resistant starch and arabinoxylan modulate digestion processes and SCFA pool size in the large intestine and faecal microbial composition in pigs.

PubMed

Nielsen, Tina S; Lærke, Helle N; Theil, Peter K; Sørensen, Jens F; Saarinen, Markku; Forssten, Sofia; Knudsen, Knud E Bach

2014-12-14

The effects of a high level of dietary fibre (DF) either as arabinoxylan (AX) or resistant starch (RS) on digestion processes, SCFA concentration and pool size in various intestinal segments and on the microbial composition in the faeces were studied in a model experiment with pigs. A total of thirty female pigs (body weight 63.1 (sem 4.4) kg) were fed a low-DF, high-fat Western-style control diet (WSD), an AX-rich diet (AXD) or a RS-rich diet (RSD) for 3 weeks. Diet significantly affected the digestibility of DM, protein, fat, NSP and NSP components, and the arabinose:xylose ratio, as well as the disappearance of NSP and AX in the large intestine. RS was mainly digested in the caecum. AX was digested at a slower rate than RS. The digesta from AXD-fed pigs passed from the ileum to the distal colon more than twice as fast as those from WSD-fed pigs, with those from RSD-fed pigs being intermediate (P< 0.001). AXD feeding resulted in a higher number of Faecalibacterium prausnitzii, Roseburia intestinalis, Blautia coccoides-Eubacterium rectale, Bifidobacterium spp. and Lactobacillus spp. in the faeces sampled at week 3 of the experimental period (P< 0.05). In the caecum, proximal and mid colon, AXD feeding resulted in a 3- to 5-fold higher pool size of butyrate compared with WSD feeding, with the RSD being intermediate (P <0.001). In conclusion, the RSD and AXD differently affected digestion processes compared with the WSD, and the AXD most efficiently shifted the microbial composition towards butyrogenic species in the faeces and increased the large-intestinal butyrate pool size.

Description of Eucyclops tziscao sp. n., E. angeli sp. n., and a new record of E. festivus Lindberg, 1955 (Cyclopoida, Cyclopidae, Eucyclopinae) in Chiapas, Mexico

PubMed Central

Gutiérrez-Aguirre, Martha Angélica; Mercado-Salas, Nancy Fabiola; Cervantes-Martínez, Adrián

2013-01-01

Abstract Two new species of the freshwater cyclopoid genera Eucyclops are described, Eucyclops tziscao sp. n. and E. angeli sp. n. Both species belong to the serrulatus-group defined by morphological features such as: the presence of distal spinules or hair-like setae (groups N1 and N2) on frontal surface of antennal basis; the fourth leg coxa with a strong inner spine that bears dense setules on inner side, yet proximally naked (large gap) on outer side; and a 12-segmented antennule with smooth hyaline membrane on the three distalmost segments. Eucyclops tziscao sp. n. is morphologically similar to E. bondi and E. conrowae but differs from these species in having a unique combination of characters, including a caudal ramus 4.05±0.25 times as long as wide, lateral seta of Enp3P4 modified as a strong, sclerotized blunt seta, coxal spine of fourth leg with inner spinule-like setules distally, and sixth leg of males bearing a strong and long inner spine 2.3 times longer than median seta. Eucyclops angeli sp. n. can be distinguished by an unique combination of morphological features: the short caudal ramus; the long spine on the sixth antennular segment of A1; the presence of one additional group of spinules (N12’) on the caudal surface of A2; the presence of long setae in females, or short spinules in males on the lateral margin of fourth prosomite; the strong ornamentation of the intercoxal sclerite of P4, specially group I modified as long denticles; the distal modified setae of Exp3P3 and Exp3P4 in females and males; and the short lateral seta of P5. Finally, we report on a new record of E. festivus in México, and add data on morphology of the species. PMID:24294085

The anterior temporal artery: an underutilized but robust donor for revascularization of the distal middle cerebral artery.

PubMed

Tayebi Meybodi, Ali; Lawton, Michael T; Griswold, Dylan; Mokhtari, Pooneh; Payman, Andre; Benet, Arnau

2017-10-01

OBJECTIVE The anterior temporal artery (ATA) supplies an area of the brain that, if sacrificed, does not cause a noticeable loss of function. Therefore, the ATA may be used as a donor in intracranial-intracranial (IC-IC) bypass procedures. The capacities of the ATA as a donor have not been studied previously. In this study, the authors assessed the feasibility of using the ATA as a donor for revascularization of different segments of the distal middle cerebral artery (MCA). METHODS The ATA was studied in 15 cadaveric specimens (8 heads, excluding 1 side). First, the cisternal segment of the artery was untethered from arachnoid adhesions and small branches feeding the anterior temporal lobe and insular cortex, to evaluate its capacity for a side-to-side bypass to insular, opercular, and cortical segments of the MCA. Any branch entering the anterior perforated substance was preserved. Then, the ATA was cut at the opercular-cortical junction and the capacity for an end-to-side bypass was assessed. RESULTS From a total of 17 ATAs, 4 (23.5%) arose as an early MCA branch. The anterior insular zone and the frontal parasylvian cortical arteries were the best targets (in terms of mobility and caliber match) for a side-to-side bypass. Most of the insula was accessible for end-to-side bypass, but anterior zones of the insula were more accessible than posterior zones. End-to-side bypass was feasible for most recipient cortical arteries along the opercula, except for posterior temporal and parietal regions. Early ATAs reached significantly farther on the insular MCA recipients than non-early ATAs for both side-to-side and end-to-side bypasses. CONCLUSIONS The ATA is a robust arterial donor for IC-IC bypass procedures, including side-to-side and end-to-side techniques. The evidence provided in this work supports the use of the ATA as a donor for distal MCA revascularization in well-selected patients.

Absence of accelerated atherosclerotic disease progression after intracoronary infusion of bone marrow derived mononuclear cells in patients with acute myocardial infarction--angiographic and intravascular ultrasound--results from the TErapia Celular Aplicada al Miocardio Pilot study.

PubMed

Arnold, Roman; Villa, Adolfo; Gutiérrez, Hipólito; Sánchez, Pedro L; Gimeno, Federico; Fernández, Maria E; Gutiérrez, Oliver; Mota, Pedro; Sánchez, Ana; García-Frade, Javier; Fernández-Avilés, Francisco; San Román, Jose A

2010-06-01

We tried to evaluate a putative negative effect on coronary atherosclerosis in patients receiving intracoronary infusion of unfractionated bone marrow mononuclear cells (BMMC) following an acute ST-elevation myocardial infarction. Peripheral blood mononuclear cells or enriched CD133(+) BMMC have been associated with accelerated atherosclerosis of the distal segment of the infarct related artery (IRA). Thirty-seven patients with ST-elevation myocardial infarction from the TECAM pilot study underwent intracoronary infusion of autologous BMMC 9 +/- 3.1 days after onset of symptoms. We compared angiographic changes from baseline to 9 months of follow-up in the distal non-stented segment of the IRA, as well as in the contralateral coronary artery, with a matched control group. A subgroup of 15 treated patients underwent additional IVUS within the distal segment of the IRA. No difference between stem cell and control group were found regarding changes in minimum lumen diameter (0.006 +/- 0.42 vs 0.06 +/- 0.41 mm, P = ns) and the percentage of stenosis (-2.68 +/- 12.33% vs -1.78 +/- 8.75%, P = ns) at follow-up. Likewise, no differences were seen regarding changes in the contralateral artery (minimum lumen diameter -0.004 +/- 0.54 mm vs -0.06 +/- 0.35 mm, P = ns). In the intravascular ultrasound substudy, no changes were demonstrated comparing baseline versus follow-up in maximum area stenosis and plaque volume. In this pilot study, analysis of a subgroup of patients found that intracoronary injection of unfractionated BMMC in patients with acute ST-elevation myocardial infarction was not associated with accelerated atherosclerosis progression at mid term. Prospective, randomised studies in large cohorts with long-term angiographic and intravascular ultrasound follow-up are necessary to determine the safety of this therapy. Copyright 2010 Mosby, Inc. All rights reserved.

Bone architecture adaptations after spinal cord injury: impact of long-term vibration of a constrained lower limb

PubMed Central

Dudley-Javoroski, S.; Petrie, M. A.; McHenry, C. L.; Amelon, R. E.; Saha, P. K.

2015-01-01

Summary This study examined the effect of a controlled dose of vibration upon bone density and architecture in people with spinal cord injury (who eventually develop severe osteoporosis). Very sensitive computed tomography (CT) imaging revealed no effect of vibration after 12 months, but other doses of vibration may still be useful to test. Introduction The purposes of this report were to determine the effect of a controlled dose of vibratory mechanical input upon individual trabecular bone regions in people with chronic spinal cord injury (SCI) and to examine the longitudinal bone architecture changes in both the acute and chronic state of SCI. Methods Participants with SCI received unilateral vibration of the constrained lower limb segment while sitting in a wheelchair (0.6g, 30 Hz, 20 min, three times weekly). The opposite limb served as a control. Bone mineral density (BMD) and trabecular micro-architecture were measured with high-resolution multi-detector CT. For comparison, one participant was studied from the acute (0.14 year) to the chronic state (2.7 years). Results Twelve months of vibration training did not yield adaptations of BMD or trabecular micro-architecture for the distal tibia or the distal femur. BMD and trabecular network length continued to decline at several distal femur sub-regions, contrary to previous reports suggesting a “steady state” of bone in chronic SCI. In the participant followed from acute to chronic SCI, BMD and architecture decline varied systematically across different anatomical segments of the tibia and femur. Conclusions This study supports that vibration training, using this study’s dose parameters, is not an effective antiosteoporosis intervention for people with chronic SCI. Using a high-spatial-resolution CT methodology and segmental analysis, we illustrate novel longitudinal changes in bone that occur after spinal cord injury. PMID:26395887

[Congenital esophageal stenosis owing to ectopic tracheobronchial remnants: report of four cases and review of the literature].

PubMed

Zhong, Xue-mei; Zhang, Yan-ling; Li, Long

2012-08-01

Congenital esophageal stenosis owing to tracheobronchial remnants (TBR) is a rare condition. This study was conducted to understand the clinical features of TBR. The data of the four cases with TBR admitted to our hospital and 76 patients identified from the literature were reviewed. The clinical manifestation, X-ray, endoscopy, biopsy and treatment were studied retrospectively. Of the total of 80 cases, 45 were male, 33 were female, and for 2 cases the gender was unknown. Symptoms of dysphagia and regurgitation developed at the age of 1-day to 12-month. Definitive treatment was carried out at the age of 1-month to 16-year. Twenty-seven patients had associated anomalies with esophageal atresia being the most prevalent. X-ray esophagography showed segmental stenosis at the distal third of the esophagus in all patients except three. An abrupt narrow segment at the lower esophagus with marked proximal dilatation was found in 32 cases. Esophagography of 12 cases showed distal esophageal stenosis with tapered narrowing. Esophagography of 20 cases showed flask-shaped shadow of distal esophageal stenosis and one patient showed linear projection of barium at the level of stenosis. Endoscopy found almost complete obstruction of the lower esophageal lumen without signs of the esophagitis or reflux. Esophagoscopic dilatation of the stenosis was attempted in 24 cases, but was ineffective, and 3 patients suffered esophageal perforation. Seventy-nine patients underwent resection of the stenotic segment. Histologic examination of the resected specimen showed cartilage, mucus glands, resembling bronchal tissue. Post-operative complication included anastomotic stenosis, anastomotic leakage, hiatal hernia, and gastroesophageal reflux. TBR should be suspected in patients who present with a typical history of dysphagia after ingestion of solid food. Esophagography and esophagoscopy are the essential means for diagnosis. TBR should be different from achalasia and should be diagnosed by biopsy. Operation is the only choice of treatment.

Endometriosis of the lung: report of a case and literature review

PubMed Central

2013-01-01

This paper reports a case of endometriosis of the lung in a 29-year-old woman with long-term periodic catamenial hemoptysis. A chest computed tomography image obtained during menstruation revealed a radiographic opaque lesion in the lingular segment of the left superior lobe. During bronchoscopy, bleeding in the mucosa of the distal bronchus of the lingular segment of the left superior lobe was observed. Histopathology subsequent to an exploratory thoracotomy confirmed the diagnosis of endometriosis of the left lung. The 2-year follow-up after lingular lobectomy of the left superior lobe showed no recurrence or complications. PMID:23634803

Local Generation and Propagation of Ripples along the Septotemporal Axis of the Hippocampus

PubMed Central

Patel, Jagdish; Schomburg, Erik W.; Berényi, Antal; Fujisawa, Shigeyoshi

2013-01-01

A topographical relationship exists between the septotemporal segments of the hippocampus and their entorhinal–neocortical targets, but the physiological organization of activity along the septotemporal axis is poorly understood. We recorded sharp-wave ripple patterns in rats during sleep from the entire septotemporal axis of the CA1 pyramidal layer. Qualitatively similar ripples emerged at all levels. From the local seed, ripples traveled septally or temporally at a speed of ∼0.35 m/s, and the spatial spread depended on ripple magnitude. Ripples propagated smoothly across the septal and intermediate segments of the hippocampus, but ripples in the temporal segment often remained isolated. These findings show that ripples can combine information from the septal and intermediate hippocampus and transfer integrated signals downstream. In contrast, ripples that emerged in the temporal pole broadcast largely independent information to their cortical and subcortical targets. PMID:24155307

System and method for evaluating a wire conductor

DOEpatents

Panozzo, Edward; Parish, Harold

2013-10-22

A method of evaluating an electrically conductive wire segment having an insulated intermediate portion and non-insulated ends includes passing the insulated portion of the wire segment through an electrically conductive brush. According to the method, an electrical potential is established on the brush by a power source. The method also includes determining a value of electrical current that is conducted through the wire segment by the brush when the potential is established on the brush. The method additionally includes comparing the value of electrical current conducted through the wire segment with a predetermined current value to thereby evaluate the wire segment. A system for evaluating an electrically conductive wire segment is also disclosed.

Genome evolution of intermediate wheatgrass as revealed by EST-SSR markers developed from its three progenitor diploid species

USDA-ARS?s Scientific Manuscript database

Intermediate wheatgrass [Thinopyrum intermedium (Host) Barkworth & D.R. Dewey], a segmental autoallohexaploid (2n=6x=42), is not only an important forage crop but also a valuable gene reservoir for wheat (Triticum aestivum L.) improvement. Throughout the scientific literature, there continues to be...

The IXV Ground Segment design, implementation and operations

NASA Astrophysics Data System (ADS)

Martucci di Scarfizzi, Giovanni; Bellomo, Alessandro; Musso, Ivano; Bussi, Diego; Rabaioli, Massimo; Santoro, Gianfranco; Billig, Gerhard; Gallego Sanz, José María

2016-07-01

The Intermediate eXperimental Vehicle (IXV) is an ESA re-entry demonstrator that performed, on the 11th February of 2015, a successful re-entry demonstration mission. The project objectives were the design, development, manufacturing and on ground and in flight verification of an autonomous European lifting and aerodynamically controlled re-entry system. For the IXV mission a dedicated Ground Segment was provided. The main subsystems of the IXV Ground Segment were: IXV Mission Control Center (MCC), from where monitoring of the vehicle was performed, as well as support during pre-launch and recovery phases; IXV Ground Stations, used to cover IXV mission by receiving spacecraft telemetry and forwarding it toward the MCC; the IXV Communication Network, deployed to support the operations of the IXV mission by interconnecting all remote sites with MCC, supporting data, voice and video exchange. This paper describes the concept, architecture, development, implementation and operations of the ESA Intermediate Experimental Vehicle (IXV) Ground Segment and outlines the main operations and lessons learned during the preparation and successful execution of the IXV Mission.

Evolution of Magnetic Rayleigh–Taylor Instability into the Outer Solar Corona and Low Interplanetary Space

NASA Astrophysics Data System (ADS)

Mishra, Sudheer K.; Singh, Talwinder; Kayshap, P.; Srivastava, A. K.

2018-03-01

We analyze the observations from Solar TErrestrial RElations Observatory (STEREO)-A and B/COR-1 of an eruptive prominence in the intermediate corona on 2011 June 7 at 08:45 UT, which consists of magnetic Rayleigh–Taylor (MRT) unstable plasma segments. Its upper-northward segment shows spatio-temporal evolution of MRT instability in form of finger structures up to the outer corona and low interplanetary space. Using the method of Dolei et al., It is estimated that the density in each bright finger is greater than the corresponding dark region lying below it in the surrounding intermediate corona. The instability is evolved due to wave perturbations that are parallel to the magnetic field at the density interface. We conjecture that the prominence plasma is supported by tension component of the magnetic field against gravity. Through the use of linear stability theory, the magnetic field is estimated as 21–40 mG to suppress growth of MRT instability in the observed finger structures. In the southward plasma segment, a horn-like structure is observed at 11:55 UT in the intermediate corona that also indicates MRT instability. Falling blobs are also observed in both of the plasma segments. In the outer corona, up to 6–13 solar radii, the mushroom-like plasma structures have been identified in the upper-northward MRT unstable plasma segment using STEREO-A/COR-2. These structures most likely grew due to the breaking and twisting of fingers at large spatial scales in weaker magnetic fields. In the lower interplanetary space up to 20 solar radii, these structures are fragmented into various small-scale localized plasma spikes, most likely due to turbulent mixing.

Structure and kinematics of segment-scale crustal accretion processes in Iceland and implications for analogous mid-ocean ridge systems

NASA Astrophysics Data System (ADS)

Siler, Drew Lorenz

2011-12-01

The sub-surface geologic structure of the crust is controlled by the magmatic and tectonic processes that construct the crust during plate spreading. As a result, geologic structure provides constraints on the processes that occur during plate spreading. The crust of the Skagi region of northern Iceland, where this study was focused, was accreted by magmatic construction to Iceland ˜7-10 Ma and subsequently glacially eroded, exhuming ˜1-3 km of structural relief. Continuous spreading-parallel and spreading-orthogonal mountain ranges expose the crust accreted at discrete spreading segments, the fundamental intervals upon which plate spreading and crustal accretion occur. As a result, Skagi is an ideal location to employ geologic structure analysis to study magmatic rifting processes. Within spreading segments structural patterns vary significantly between segment centers and distal fissure swarms. While segment centers are characterized by focused magmatic construction and km-scale sub-volcanic subsidence, fissure swarms are characterized by limited magmatic construction, minor sub-axial subsidence and lateral dike injection. Such along-strike variation indicates that both magma in the upper crust and gabbroic material in the lower crust must be redistributed along-strike within spreading segments during plate spreading. Material flow is directed from beneath segment centers towards distal fissure swarms. At the regional scale, each spreading segment is a structurally discrete interval of Iceland's Neovolcanic Zone. As a result of west-northwestward movement of Iceland relative to the Iceland hotspot, the rift zone axis has progressively relocated to the east-southeast with time, leaving a series of abandoned rift zones throughout western Iceland. A compilation of published K/Ar and 40Ar/39Ar age data and geologic data from across northern Iceland shows that rift relocation occurs via frequent (2-3 Ma), small-scale (˜20 km) rift propagations rather than rare, 100s of km 'rift jumps' as is conventional models suggest. The structure relationships we define in the Icelandic crust are similar to that of other magmatic rift systems including Mid-Ocean Ridges, continental rifts and ancient volcanic rift margins. As such, we suggest that many of the crustal accretion processes we have inferred from Icelandic data may be important in these analogous environments as well.

Recurrent neuroma formation after lateral arm free flap coverage with neurorraphy to the posteroantebrachial nerve.

PubMed

Peterson, Steven L; Gordon, Michael J

2004-09-01

We report a patient with previous wrist trauma and development of a symptomatic neuroma of the palmar cutaneous branch of the median nerve. The patient had previously been successfully treated with lateral arm free flap coverage with neurorrhaphy to a segment of the posteroantebrachial cutaneous nerve carried with the flap. Two years following this procedure the patient experienced re-onset of symptoms prompting surgical exploration of the area. At the time of operation a recurrent neuroma was found at the free distal terminus of the transferred posteroantebrachial cutaneous nerve. The neuroma was repositioned into the distal radius via a burr hole with relief of symptoms.

Evaluation of a risk index for advanced proximal neoplasia of the colon.

PubMed

Ruco, Arlinda; Stock, David; Hilsden, Robert J; McGregor, S Elizabeth; Paszat, Lawrence F; Saskin, Refik; Rabeneck, Linda

2015-01-01

A clinical risk index that uses distal colorectal findings at flexible sigmoidoscopy (FS) in conjunction with easily determined risk factors for advanced proximal neoplasia (APN) may be useful for tailoring or prioritizing screening with colonoscopy. To conduct an external evaluation of a previously published risk index in a large, well-characterized cohort. Cross-sectional. Teaching hospital and colorectal cancer screening center. A total of 5139 asymptomatic persons aged 50 to 74 (54.9% women) with a mean age (±SD) of 58.3 (±6.2) years. Between 2003 and 2011, all participants underwent a complete screening colonoscopy and removal of all polyps. Participants were classified as low, intermediate, or high risk for APN, based on their composite risk index scores. The concordance or c-statistic was used to measure discriminating ability of the risk index. A total of 167 persons (3.2%) had APN. The prevalence of those with APN among low-, intermediate-, and high-risk categories was 2.1%, 2.9%, and 6.5%, respectively. High-risk individuals were 3.2 times more likely to have APN compared with those in the low-risk category. The index did not discriminate well between those in the low- and intermediate-risk categories. The c-statistic for the overall index was 0.62 (95% confidence interval, 0.58-0.66). Distal colorectal findings were derived from colonoscopies and not FS itself. The risk index discriminated between those at low risk and those at high risk, but it had limited ability to discriminate between low- and intermediate-risk categories for prevalent APN. Information on other risk factors may be needed to tailor, or prioritize, access to screening colonoscopy. Copyright © 2015 American Society for Gastrointestinal Endoscopy. Published by Elsevier Inc. All rights reserved.

Accurate positioning of long, flexible ARM's (Articulated Robotic Manipulator)

NASA Technical Reports Server (NTRS)

Malachowski, Michael J.

1988-01-01

An articulated robotic manipulator (ARM) system is being designed for space applications. Work being done on a concept utilizing an infinitely stiff laser beam for position reference is summarized. The laser beam is projected along the segments of the ARM, and the position is sensed by the beam rider modules (BRM) mounted on the distal ends of the segments. The BRM concept is the heart of the system. It utilizes a combination of lateral displacements and rotational and distance measurement sensors. These determine the relative position of the two ends of the segments with respect to each other in six degrees of freedom. The BRM measurement devices contain microprocessor controlled data acquisition and active positioning components. An indirect adaptive controller is used to accurately control the position of the ARM.

Disorders of interstitial cells of Cajal in a neonate with segmental dilatation of the intestine.

PubMed

Okada, Tadao; Sasaki, Fumiaki; Honda, Shohei; Cho, Kazutosi; Matsuno, Yoshihiro; Itoh, Tomoo; Kubota, Kanako C; Todo, Satoru

2010-06-01

Localized myopathy of the muscular layers may be an important factor contributing to segmental dilatation of the intestine (SDI). Only one report has described SDI of the jejunum in a neonate showing no abnormality of the interstitial cells of Cajal (ICC). The present report describes the very rare case of a neonatal girl with segmental dilatation of the distal duodenum and proximal jejunum with irregular arrangements of Auerbach's plexus and ICC and the successful surgical treatment of SDI. We review the literature on this type of relationship between abnormality of ICC and SDI and discuss the clinical features of this complication. Furthermore, the possible neuropathic cause of SDI complicated with disorders of ICC was explored in this report. Copyright 2010 Elsevier Inc. All rights reserved.

The effects of body proportions on thermoregulation: an experimental assessment of Allen's rule.

PubMed

Tilkens, Michael J; Wall-Scheffler, Cara; Weaver, Timothy D; Steudel-Numbers, Karen

2007-09-01

Numerous studies have discussed the influence of thermoregulation on hominin body shape concluding, in accordance with Allen's rule, that the presence of relatively short limbs on both extant as well as extinct hominin populations offers an advantage for survival in cold climates by reducing the limb's surface area to volume ratio. Moreover, it has been suggested that shortening the distal limb segment compared to the proximal limb segment may play a larger role in thermoregulation due to a greater relative surface area of the shank. If longer limbs result in greater heat dissipation, we should see higher resting metabolic rates (RMR) in longer-limbed individuals when temperature conditions fall, since the resting rate will need to replace the lost heat. We collected resting oxygen consumption on volunteer human subjects to assess the correlation between RMR and lower limb length in human subjects, as well as to reexamine the prediction that shortening the distal segment would have a larger effect on heat loss and, thus, RMR than the shortening of the proximal segment. Total lower limb length exhibits a statistically significant relationship with resting metabolic rate (p<0.001; R(2)=0.794). While this supports the hypothesis that as limb length increases, resting metabolic rate increases, it also appears that thigh length, rather than the length of the shank, drives this relationship. The results of the present study confirm the widely-held expectation of Allen's rule, that short limbs reduce the metabolic cost of maintaining body temperature, while long limbs result in greater heat dissipation regardless of the effect of mass. The present results suggest that the shorter limbs of Neandertals, despite being energetically disadvantageous while walking, would indeed have been advantageous for thermoregulation.

Movement coordination patterns between the foot joints during walking.

PubMed

Arnold, John B; Caravaggi, Paolo; Fraysse, François; Thewlis, Dominic; Leardini, Alberto

2017-01-01

In 3D gait analysis, kinematics of the foot joints are usually reported via isolated time histories of joint rotations and no information is provided on the relationship between rotations at different joints. The aim of this study was to identify movement coordination patterns in the foot during walking by expanding an existing vector coding technique according to an established multi-segment foot and ankle model. A graphical representation is also described to summarise the coordination patterns of joint rotations across multiple patients. Three-dimensional multi-segment foot kinematics were recorded in 13 adults during walking. A modified vector coding technique was used to identify coordination patterns between foot joints involving calcaneus, midfoot, metatarsus and hallux segments. According to the type and direction of joints rotations, these were classified as in-phase (same direction), anti-phase (opposite directions), proximal or distal joint dominant. In early stance, 51 to 75% of walking trials showed proximal-phase coordination between foot joints comprising the calcaneus, midfoot and metatarsus. In-phase coordination was more prominent in late stance, reflecting synergy in the simultaneous inversion occurring at multiple foot joints. Conversely, a distal-phase coordination pattern was identified for sagittal plane motion of the ankle relative to the midtarsal joint, highlighting the critical role of arch shortening to locomotor function in push-off. This study has identified coordination patterns between movement of the calcaneus, midfoot, metatarsus and hallux by expanding an existing vector cording technique for assessing and classifying coordination patterns of foot joints rotations during walking. This approach provides a different perspective in the analysis of multi-segment foot kinematics, and may be used for the objective quantification of the alterations in foot joint coordination patterns due to lower limb pathologies or following injuries.

The influence of predegenerated nerve grafts on axonal regeneration from prelesioned peripheral nerves.

PubMed

Hasan, N A; Neumann, M M; de Souky, M A; So, K F; Bedi, K S

1996-10-01

Recent in vitro work has indicated that predegenerated segments of peripheral nerve are more capable of supporting neurite growth from adult neurons than fresh segments of nerve, whereas previous in vivo studies which investigated whether predegenerated nerve segments used as grafts are capable of enhancing axonal regeneration produced conflicting results. We have reinvestigated this question by using predegenerated nerve grafts in combination with conditioning lesions of the host nerve to determine the optimal conditions for obtaining the maximal degree of regeneration of myelinated axons. The sciatic nerve of adult Dark Agouti rats were sectioned at midthigh level, and the distal portion was allowed to predegenerate for 0, 6 or 12 d in situ. 10-15 mm lengths of these distal nerve segments were then syngenically grafted onto the central stumps of sciatic nerves which had themselves received a conditioning lesion 0, 6, and 12 d previously, making a total of 9 different donor-host combinations. The grafts were assessed histologically 3 or 8 wk after grafting. Axonal regeneration in the 9 different donor-host combinations was determined by counting the numbers of myelinated axons in transverse sections through the grafts. All grafts examined contained regenerating myelinated axons. The rats given a 3 wk postgrafting survival period had an average of between 1400 and 5300 such axons. The rats given an 8 wk postgrafting survival period had between about 13,000 and 25,000 regenerating myelinated axons. Analysis of variance revealed significant main effects for both the Donor and Host conditions as well as Weeks (i.e. survival period after grafting). These results indicate that both a conditioning lesion of the host neurons and the degree of predegeneration of peripheral nerve segments to be used as grafts are of importance in influencing the degree of axonal regeneration. Of these 2 factors the conditioning lesion of the host appears to have the greater effect on the final number of regenerating myelinated axons.

Differential regulation of proximal and distal Vbeta segments upstream of a functional VDJbeta1 rearrangement upon beta-selection.

PubMed

Brady, Brenna L; Bassing, Craig H

2011-09-15

Developmental stage-specific regulation of transcriptional accessibility helps control V(D)J recombination. Vβ segments on unrearranged TCRβ alleles are accessible in CD4(-)/CD8(-) (double-negative [DN]) thymocytes, when they recombine, and inaccessible in CD4(+)/CD8(+) (double-positive [DP]) thymocytes, when they do not rearrange. Downregulation of Vβ accessibility on unrearranged alleles is linked with Lat-dependent β-selection signals that inhibit Vβ rearrangement, stimulate Ccnd3-driven proliferation, and promote DN-to-DP differentiation. Transcription and recombination of Vβs on VDJβ-rearranged alleles in DN cells has not been studied; Vβs upstream of functional VDJβ rearrangements have been found to remain accessible, yet not recombine, in DP cells. To elucidate contributions of β-selection signals in regulating Vβ transcription and recombination on VDJβ-rearranged alleles, we analyzed wild-type, Ccnd3(-/-), and Lat(-/-) mice containing a preassembled functional Vβ1DJCβ1 (Vβ1(NT)) gene. Vβ10 segments located just upstream of this VDJCβ1 gene were the predominant germline Vβs that rearranged in Vβ1(NT/NT) and Vβ1(NT/NT)Ccnd3(-/-) thymocytes, whereas Vβ4 and Vβ16 segments located further upstream rearranged at similar levels as Vβ10 in Vβ1(NT/NT)Lat(-/-) DN cells. We previously showed that Vβ4 and Vβ16, but not Vβ10, are transcribed on Vβ1(NT) alleles in DP thymocytes; we now demonstrate that Vβ4, Vβ16, and Vβ10 are transcribed at similar levels in Vβ1(NT/NT)Lat(-/-) DN cells. These observations indicate that suppression of Vβ rearrangements is not dependent on Ccnd3-driven proliferation, and DN residence can influence the repertoire of Vβs that recombine on alleles containing an assembled VDJCβ1 gene. Our findings also reveal that β-selection can differentially silence rearrangement of germline Vβ segments located proximal and distal to functional VDJβ genes.

Mechanical evaluation of external skeletal fixator-intramedullary pin tie-in configurations applied to cadaveral humeri from red-tailed hawks (Buteo jamaicensis).

PubMed

Van Wettere, Arnaud J; Redig, Patrick T; Wallace, Larry J; Bourgeault, Craig A; Bechtold, Joan E

2009-12-01

Use of external skeletal fixator-intramedullary pin (ESF-IM) tie-in fixators is an adjustable and effective method of fracture fixation in birds. The objective of this study was to determine the contribution of each of the following parameters to the compressive and torsional rigidity of an ESF-IM pin tie-in applied to avian bones with an osteotomy gap: (1) varying the fixation pin position in the proximal bone segment and (2) increasing the number of fixation pins in one or both bone segments. ESF-IM pin tie-in constructs were applied to humeri harvested from red-tailed hawks (Buteo jamaicensis) (n=24) that had been euthanatized for clinical reasons. Constructs with a variation in the placement of the proximal fixation pin and with 2, 3, or 4 fixation pins applied to avian bone with an osteotomy gap were loaded to a defined displacement in torque and axial compression. Response variables were determined from resulting load-displacement curves (construct stiffness, load at 1-mm displacement). Increasing the number of fixation pins from 1 to 2 per bone segment significantly increased the stiffness in torque (110%) and compression (60%), and the safe load in torque (107%) and compression (50%). Adding a fixation pin to the distal bone segment to form a 3-pin fixator significantly increased the stiffness (27%) and safe load (20%) in torque but not in axial compression. In the configuration with 2 fixation pins, placing the proximal pin distally in the proximal bone segment significantly increased the stiffness in torque (28%), and the safe load in torque (23%) and in axial compression (32%). Results quantified the relative importance of specific parameters affecting the rigidity of ESF-IM pin tie-in constructs as applied to unstable bone fracture models in birds.

Sequential cloning of chromosomes

DOEpatents

Lacks, Sanford A.

1995-07-18

A method for sequential cloning of chromosomal DNA of a target organism is disclosed. A first DNA segment homologous to the chromosomal DNA to be sequentially cloned is isolated. The first segment has a first restriction enzyme site on either side. A first vector product is formed by ligating the homologous segment into a suitably designed vector. The first vector product is circularly integrated into the target organism's chromosomal DNA. The resulting integrated chromosomal DNA segment includes the homologous DNA segment at either end of the integrated vector segment. The integrated chromosomal DNA is cleaved with a second restriction enzyme and ligated to form a vector-containing plasmid, which is replicated in a host organism. The replicated plasmid is then cleaved with the first restriction enzyme. Next, a DNA segment containing the vector and a segment of DNA homologous to a distal portion of the previously isolated DNA segment is isolated. This segment is then ligated to form a plasmid which is replicated within a suitable host. This plasmid is then circularly integrated into the target chromosomal DNA. The chromosomal DNA containing the circularly integrated vector is treated with a third, retrorestriction (class IIS) enzyme. The cleaved DNA is ligated to give a plasmid that is used to transform a host permissive for replication of its vector. The sequential cloning process continues by repeated cycles of circular integration and excision. The excision is carried out alternately with the second and third enzymes.

Upper-extremity phocomelia reexamined: a longitudinal dysplasia.

PubMed

Goldfarb, Charles A; Manske, Paul R; Busa, Riccardo; Mills, Janith; Carter, Peter; Ezaki, Marybeth

2005-12-01

In contrast to longitudinal deficiencies, phocomelia is considered a transverse, intercalated segmental dysplasia. Most patients demonstrate severe, but not otherwise classifiable, upper-extremity deformities, which usually cannot be placed into one of three previously described phocomelia groups. Additionally, these phocomelic extremities do not demonstrate true segmental deficits; the limb is also abnormal proximal and distal to the segmental defect. The purpose of this investigation was to present evidence that upper-extremity abnormalities in patients previously diagnosed as having phocomelia in fact represent a proximal continuum of radial or ulnar longitudinal dysplasia. The charts and radiographs of forty-one patients (sixty extremities) diagnosed as having upper-extremity phocomelia were reviewed retrospectively. On the basis of the findings on the radiographs, the disorders were categorized into three groups: (1) proximal radial longitudinal dysplasia, which was characterized by an absent proximal part of the humerus, a nearly normal distal part of the humerus, a completely absent radius, and a radial-sided hand dysplasia; (2) proximal ulnar longitudinal dysplasia, characterized by a short one-bone upper extremity that bifurcated distally and by severe hand abnormalities compatible with ulnar dysplasia; and (3) severe combined dysplasia, with type A characterized by an absence of the forearm segment (i.e., the radius and ulna) and type B characterized by absence of the arm and forearm (i.e., the hand attached to the thorax). Twenty-nine limbs in sixteen patients could be classified as having proximal radial longitudinal dysplasia. Systemic medical conditions such as thrombocytopenia-absent radius syndrome were common in those patients, but additional musculoskeletal conditions were rare. Twenty limbs in seventeen patients could be classified as having proximal ulnar longitudinal dysplasia. Associated musculoskeletal abnormalities, such as proximal femoral focal deficiency, were common in those patients. Eleven limbs in ten patients were identified as having severe combined dysplasia, which was type A in seven of them and type B in four. Four patients with severe combined dysplasia had congenital cardiac anomalies, and four had associated musculoskeletal abnormalities. Three of the four patients with the type-B disorder had a contralateral ulnar longitudinal dysplasia. We propose that cases previously classified as upper-extremity phocomelia represent a spectrum of severe longitudinal dysplasia, as none of the sixty extremities that we studied demonstrated a true intercalary deficiency. These findings have both developmental and genetic implications.

A potential means of improving the evaluation of deformity corrections with Taylor spatial frames over time by using volumetric imaging: preliminary results.

PubMed

Starr, Vanessa; Olivecrona, H; Noz, M E; Maguire, G Q; Zeleznik, M P; Jannsson, Karl-åke

2009-01-01

In this study we explore the possibility of accurately and cost-effectively monitoring tibial deformation induced by Taylor Spatial Frames (TSFs), using time-separated computed tomography (CT) scans and a volume fusion technique to determine tibial rotation and translation. Serial CT examinations (designated CT-A and CT-B, separated by a time interval of several months) of two patients were investigated using a previously described and validated volume fusion technique, in which user-defined landmarks drive the 3D registration of the two CT volumes. Both patients had undergone dual osteotomies to correct for tibial length and rotational deformity. For each registration, 10 or more landmarks were selected, and the quality of the fused volume was assessed both quantitatively and via 2D and 3D visualization tools. First, the proximal frame segment and tibia in CT-A and CT-B were brought into alignment (registered) by selecting landmarks on the frame and/or tibia. In the resulting "fused" volume, the proximal frame segment and tibia from CT-A and CT-B were aligned, while the distal frame segment and tibia from CT-A and CT-B were likely not aligned as a result of tibial deformation or frame adjustment having occurred between the CT scans. Using the proximal fused volume, the distal frame segment and tibia were then registered by selecting landmarks on the frame and/or tibia. The difference between the centroids of the final distal landmarks was used to evaluate the lengthening of the tibia, and the Euler angles from the registration were used to evaluate the rotation. Both the frame and bone could be effectively registered (based on visual interpretation). Movement between the proximal frame and proximal bone could be visualized in both cases. The spatial effect on the tibia could be both visually assessed and measured: 34 mm, 10 degrees in one case; 5 mm, 1 degrees in the other. This retrospective analysis of spatial correction of the tibia using Taylor Spatial Frames shows that CT offers an interesting potential means of quantitatively monitoring the patient's treatment. Compared with traditional techniques, modern CT scans in conjunction with image processing provide a high-resolution, spatially correct, and three-dimensional measurement system which can be used to quickly and easily assess the patient's treatment at low cost to the patient and hospital.

BBSome function is required for both the morphogenesis and maintenance of the photoreceptor outer segment

PubMed Central

Hsu, Ying; Kim, Gunhee; Zhang, Qihong; Datta, Poppy; Seo, Seongjin

2017-01-01

Genetic mutations disrupting the structure and function of primary cilia cause various inherited retinal diseases in humans. Bardet-Biedl syndrome (BBS) is a genetically heterogeneous, pleiotropic ciliopathy characterized by retinal degeneration, obesity, postaxial polydactyly, intellectual disability, and genital and renal abnormalities. To gain insight into the mechanisms of retinal degeneration in BBS, we developed a congenital knockout mouse of Bbs8, as well as conditional mouse models in which function of the BBSome (a protein complex that mediates ciliary trafficking) can be temporally inactivated or restored. We demonstrate that BBS mutant mice have defects in retinal outer segment morphogenesis. We further demonstrate that removal of Bbs8 in adult mice affects photoreceptor function and disrupts the structural integrity of the outer segment. Notably, using a mouse model in which a gene trap inhibiting Bbs8 gene expression can be removed by an inducible FLP recombinase, we show that when BBS8 is restored in immature retinas with malformed outer segments, outer segment extension can resume normally and malformed outer segment discs are displaced distally by normal outer segment structures. Over time, the retinas of the rescued mice become morphologically and functionally normal, indicating that there is a window of plasticity when initial retinal outer segment morphogenesis defects can be ameliorated. PMID:29049287

An algorithm for calculi segmentation on ureteroscopic images.

PubMed

Rosa, Benoît; Mozer, Pierre; Szewczyk, Jérôme

2011-03-01

The purpose of the study is to develop an algorithm for the segmentation of renal calculi on ureteroscopic images. In fact, renal calculi are common source of urological obstruction, and laser lithotripsy during ureteroscopy is a possible therapy. A laser-based system to sweep the calculus surface and vaporize it was developed to automate a very tedious manual task. The distal tip of the ureteroscope is directed using image guidance, and this operation is not possible without an efficient segmentation of renal calculi on the ureteroscopic images. We proposed and developed a region growing algorithm to segment renal calculi on ureteroscopic images. Using real video images to compute ground truth and compare our segmentation with a reference segmentation, we computed statistics on different image metrics, such as Precision, Recall, and Yasnoff Measure, for comparison with ground truth. The algorithm and its parameters were established for the most likely clinical scenarii. The segmentation results are encouraging: the developed algorithm was able to correctly detect more than 90% of the surface of the calculi, according to an expert observer. Implementation of an algorithm for the segmentation of calculi on ureteroscopic images is feasible. The next step is the integration of our algorithm in the command scheme of a motorized system to build a complete operating prototype.

Ion transport in proximal colon of the rat. Sodium depletion stimulates neutral sodium chloride absorption.

PubMed Central

Foster, E S; Budinger, M E; Hayslett, J P; Binder, H J

1986-01-01

The model of sodium and chloride transport proposed for the colon is based on studies performed in the distal segment and tacitly assumes that ion transport is similar throughout the colon. In rat distal colon, neutral sodium-chloride absorption accounts for the major fraction of overall sodium absorption and aldosterone stimulates electrogenic, amiloride-sensitive sodium absorption. Since we have demonstrated qualitative differences in potassium transport in proximal and distal segments of rat colon, unidirectional 22Na and 36Cl fluxes were performed under short-circuit conditions across isolated proximal colon of control and sodium-depleted rats with secondary hyperaldosteronism. In the control group, net sodium absorption (JNanet) (7.4 +/- 0.5 mu eq/h . cm2) was greater than Isc (1.4 +/- 0.1 mu eq/h . cm2), and JClnet was 0 in Ringer solution. Residual flux (JR) was -5.2 +/- 0.5 mu eq/h . cm2 consistent with hydrogen ion secretion suggesting that neutral sodium absorption may represent sodium-hydrogen exchange. 1 mM mucosal amiloride, which inhibits sodium-hydrogen exchange in other epithelia, produced comparable decreases in JNanet and JR (4.1 +/- 0.6 and 3.2 +/- 0.6 mu eq/h . cm2, respectively) without a parallel fall in Isc. Sodium depletion stimulated JNanet, JClnet, and Isc by 7.0 +/- 1.4, 6.3 +/- 1.9, and 0.8 +/- 0.2 mu eq/h . cm2, respectively, and 1 mM amiloride markedly inhibited JNanet and JClnet by 6.0 +/- 1.1 and 4.0 +/- 1.6 mu eq/h . cm2, respectively, with only a minimal reduction in Isc. Conclusions: the predominant neutral sodium-absorptive mechanism in proximal colon is sodium-hydrogen exchange. Sodium depletion stimulates electroneutral chloride-dependent sodium absorption (most likely as a result of increasing sodium-hydrogen and chloride-bicarbonate exchanges), not electrogenic chloride-independent sodium transport. The model of ion transport in the proximal colon is distinct from that of the distal colon. PMID:2418060

Removal of well-fixed components in femoral revision arthroplasty with controlled segmentation of the proximal femur.

PubMed

Megas, Panagiotis; Georgiou, Christos S; Panagopoulos, Andreas; Kouzelis, Antonis

2014-12-31

The transfemoral and the extended trochanteric osteotomies are the most common osteotomies used in femoral revision, both when proximal or diaphyseal fixation of the new component has been decided. We present an alternative approach to the trochanteric osteotomies, most frequently used with distally fixated stems, to overcome their shortcomings of osteotomy migration and nonunion, but, most of all, the uncontrollable fragmentation of the femur. The procedure includes a complete circular femoral osteotomy just below the stem tip to prevent distal fracture propagation and a subsequent preplanned segmentation of the proximal femur for better exposure and fast removal of the old prosthesis. The bone fragments are reattached with cerclage wires to the revision prosthesis, which is safely anchored distally. A modified posterolateral approach is used, as the preservation of the continuity of the abductors, the greater trochanter, and the vastus lateralis is a prerequisite. Between 2006 and 2012, 47 stems (33 women, 14 men, mean age 68 years, range 39-88 years) were revised using this technique. They were 12 (26%) stable and 35 (74%) loose prostheses and were all revised to tapered, fluted, grit-blasted stems. No fracture of the trochanters or the distal femur occurred intraoperatively. Mean follow-up was 28 months (range 6-70 months). No case of trochanteric migration or nonunion of the osteotomies was recorded. Restoration of the preexisting bone defects occurred in 83% of the patients. Three patients required repeat revision due to dislocation and one due to a postoperative periprosthetic fracture. None of the failures was attributed to the procedure itself. This new osteotomy technique may seem aggressive at first, but, at least in our hands, has effectively increased the speed of the femoral revision, particularly for the most difficult well-fixed components, but not at the expense of safety.

Attention and L2 Learners' Segmentation of Complex Sentences

ERIC Educational Resources Information Center

Hagiwara, Akiko

2010-01-01

The main objective of the current study is to investigate L2 Japanese learners' ability to segment complex sentences from aural input. Elementary- and early intermediate-level L2 learners in general have not developed the ability to use syntactic cues to interpret the meaning of sentences they hear. In the case of Japanese, recognition of…

Distinct degree of radiculopathy at different levels of peripheral nerve injury

PubMed Central

2012-01-01

Background Lumbar radiculopathy is a common clinical problem, characterized by dorsal root ganglion (DRG) injury and neural hyperactivity causing intense pain. However, the mechanisms involved in DRG injury have not been fully elucidated. Furthermore, little is known about the degree of radiculopathy at the various levels of nerve injury. The purpose of this study is to compare the degree of radiculopathy injury at the DRG and radiculopathy injury proximal or distal to the DRG. Results The lumbar radiculopathy rat model was created by ligating the L5 nerve root 2 mm proximal to the DRG or 2 mm distal to the DRG with 6.0 silk. We examined the degree of the radiculopathy using different points of mechanical sensitivity, immunohistochemistry and in vivo patch-clamp recordings, 7 days after surgery. The rats injured distal to the DRG were more sensitive than those rats injured proximal to the DRG in the behavioral study. The number of activated microglia in laminas I–II of the L5 segmental level was significantly increased in rats injured distal to the DRG when compared with rats injured proximal to the DRG. The amplitudes and frequencies of EPSC in the rats injured distal to the DRG were higher than those injured proximal to the DRG. The results indicated that there is a different degree of radiculopathy at the distal level of nerve injury. Conclusions Our study examined the degree of radiculopathy at different levels of nerve injury. Severe radiculopathy occurred in rats injured distal to the DRG when compared with rats injured proximal to the DRG. This finding helps to correctly diagnose a radiculopathy. PMID:22537715

Requirement of Multiple cis-Acting Elements in the Human Cytomegalovirus Major Immediate-Early Distal Enhancer for Viral Gene Expression and Replication

PubMed Central

Meier, Jeffery L.; Keller, Michael J.; McCoy, James J.

2002-01-01

We have shown previously that the human cytomegalovirus (HCMV) major immediate-early (MIE) distal enhancer is needed for MIE promoter-dependent transcription and viral replication at low multiplicities of infection (MOI). To understand how this region works, we constructed and analyzed a series of HCMVs with various distal enhancer mutations. We show that the distal enhancer is composed of at least two parts that function independently to coordinately activate MIE promoter-dependent transcription and viral replication. One such part is contained in a 47-bp segment that has consensus binding sites for CREB/ATF, SP1, and YY1. At low MOI, these working parts likely function in cis to directly activate MIE gene expression, thus allowing viral replication to ensue. Three findings support the view that these working parts are likely cis-acting elements. (i) Deletion of either part of a bisegmented distal enhancer only slightly alters MIE gene transcription and viral replication. (ii) Reversing the distal enhancer’s orientation largely preserves MIE gene transcription and viral replication. (iii) Placement of stop codons at −300 or −345 in all reading frames does not impair MIE gene transcription and viral replication. Lastly, we show that these working parts are dispensable at high MOI, partly because of compensatory stimulation of MIE promoter activity and viral replication that is induced by a virion-associated component(s) present at a high viral particle/cell ratio. We conclude that the distal enhancer is a complex multicomponent cis-acting region that is required to augment both MIE promoter-dependent transcription and HCMV replication. PMID:11739696

Reactive Balance Control in Response to Perturbation in Unilateral Stance: Interaction Effects of Direction, Displacement and Velocity on Compensatory Neuromuscular and Kinematic Responses

PubMed Central

Freyler, Kathrin; Gollhofer, Albert; Colin, Ralf; Brüderlin, Uli; Ritzmann, Ramona

2015-01-01

Unexpected sudden perturbations challenge postural equilibrium and require reactive compensation. This study aimed to assess interaction effects of the direction, displacement and velocity of perturbations on electromyographic (EMG) activity, centre of pressure (COP) displacement and joint kinematics to detect neuromuscular characteristics (phasic and segmental) and kinematic strategies of compensatory reactions in an unilateral balance paradigm. In 20 subjects, COP displacement and velocity, ankle, knee and hip joint excursions and EMG during short (SLR), medium (MLR) and long latency response (LLR) of four shank and five thigh muscles were analysed during random surface translations varying in direction (anterior-posterior (sagittal plane), medial-lateral (frontal plane)), displacement (2 vs. 3cm) and velocity (0.11 vs. 0.18m/s) of perturbation when balancing on one leg on a movable platform. Phases: SLR and MLR were scaled to increased velocity (P<0.05); LLR was scaled to increased displacement (P<0.05). Segments: phasic interrelationships were accompanied by segmental distinctions: distal muscles were used for fast compensation in SLR (P<0.05) and proximal muscles to stabilise in LLR (P<0.05). Kinematics: ankle joints compensated for both increasing displacement and velocity in all directions (P<0.05), whereas knee joint deflections were particularly sensitive to increasing displacement in the sagittal (P<0.05) and hip joint deflections to increasing velocity in the frontal plane (P<0.05). COP measures increased with increasing perturbation velocity and displacement (P<0.05). Interaction effects indicate that compensatory responses are based on complex processes, including different postural strategies characterised by phasic and segmental specifications, precisely adjusted to the type of balance disturbance. To regain balance after surface translation, muscles of the distal segment govern the quick regain of equilibrium; the muscles of the proximal limb serve as delayed stabilisers after a balance disturbance. Further, a kinematic distinction regarding the compensation for balance disturbance indicated different plane- and segment-specific sensitivities with respect to the determinants displacement and velocity. PMID:26678061

Segmental dependent transport of low permeability compounds along the small intestine due to P-glycoprotein: the role of efflux transport in the oral absorption of BCS class III drugs.

PubMed

Dahan, Arik; Amidon, Gordon L

2009-01-01

The purpose of this study was to investigate the role of P-gp efflux in the in vivo intestinal absorption process of BCS class III P-gp substrates, i.e. high-solubility low-permeability drugs. The in vivo permeability of two H (2)-antagonists, cimetidine and famotidine, was determined by the single-pass intestinal perfusion model in different regions of the rat small intestine, in the presence or absence of the P-gp inhibitor verapamil. The apical to basolateral (AP-BL) and the BL-AP transport of the compounds in the presence or absence of various efflux transporters inhibitors (verapamil, erythromycin, quinidine, MK-571 and fumitremorgin C) was investigated across Caco-2 cell monolayers. P-gp expression levels in the different intestinal segments were confirmed by immunoblotting. Cimetidine and famotidine exhibited segmental dependent permeability through the gut wall, with decreased P(eff) in the distal ileum in comparison to the proximal regions of the intestine. Coperfusion of verapamil with the drugs significantly increased the permeability in the ileum, while no significant change in the jejunal permeability was observed. Both drugs exhibited significantly greater BL-AP than AP-BL Caco-2 permeability, indicative of net mucosal secretion. Concentration dependent decrease of this secretion was obtained by the P-gp inhibitors verapamil, erythromycin and quinidine, while no effect was evident by the MRP2 inhibitor MK-571 and the BCRP inhibitor FTC, indicating that P-gp is the transporter mediates the intestinal efflux of cimetidine and famotidine. P-gp levels throughout the intestine were inversely related to the in vivo permeability of the drugs from the different segments. The data demonstrate that for these high-solubility low-permeability P-gp substrates, P-gp limits in vivo intestinal absorption in the distal segments of the small intestine; however P-gp plays a minimal role in the proximal intestinal segments due to significant lower P-gp expression levels in this region.

Subarachnoid Hemorrhage Because of Distal Superior Cerebellar Artery Dissection in Neurofibromatosis Type 1.

PubMed

Takeshima, Yuki; Ohmori, Yuki; Nakagawa, Takashi; Kaku, Yasuyuki; Kuratsu, Jun-Ichi; Yano, Shigetoshi

2017-09-01

Neurofibromatosis type 1 (NF1) is a rare disease with an incidence of 1 in every 3000 births. Numerous studies have focused on the main function of NF1 as a tumor suppressor, whereas few have examined the cerebrovascular abnormalities observed in patients with NF1. It is worth noting that intracranial aneurysms are uncommon in this condition. We report a case of NF1 with a dissection of the distal segment of the superior cerebellar artery. A 36-year-old woman presented with a distal superior cerebellar artery (SCA) dissection causing subarachnoid hemorrhage. Subsequently, because of the rich collateral blood flow distal to the dissection, N-butyl cyanoacrylate (NBCA) glue embolization was unsuccessful. Therefore, direct trapping of the artery was necessary. The patient was discharged after an uneventful postoperative period, and has remained without complications. In the treatment of subarachnoid hemorrhage because of a distal SCA dissection in patients with NF1, NBCA glue embolization may be a safer option than microsurgery or coil embolization, in the acute phase, considering the possible vulnerability of the vessel wall, accessibility, morphology of the lesions, and the risk of developing unpredictable infarcts in the case of parent artery occlusion. However, regular reevaluation of the blood flow is necessary to monitor recurrence, given the rich collateral circulation. Copyright © 2017 Elsevier Inc. All rights reserved.

The first experience of robot assisted spleen-preserving laparoscopic distal pancreatectomy in Korea.

PubMed

Kim, Dong Hyun; Kang, Chang Moo; Lee, Woo Jung; Chi, Hoon Sang

2011-05-01

Spleen-preservation has recently been emphasized in benign and borderline malignant pancreatic diseases requiring distal pancreatectomy. Reports to suggest that laparoscopic distal pancreatectomy is feasible and safe have been increasingly published. Robotic surgical system has been introduced and is expected to provide unique advantages in laparoscopic surgery. However, robot-assisted pancreatic surgery has not yet been performed by many surgeons. A 45-year-old female patient with abdominal discomfort was found to have pancreatic cyst in the body of the pancreas. Mucinous cystic tumor of the pancreas was the most favourable preoperative diagnosis. She underwent spleen-preserving laparoscopic distal pancreatectomy by using da Vinci surgical robot system. Splenic artery and vein were so tightly adherent to the pancreatic cyst that segmental resection of splenic vessels was required. Postoperative course was uneventful. She was able to come home in 5 days after surgery. Postoperative follow up color doppler ultrasound scan, taken on 2 weeks after surgery, showed minimal fluid collection around surgical field and no evidence of splenic infarction with good preservation of splenic perfusion. Robot-assisted spleen preserving distal pancreatectomy is thought to be feasible and safe. Several unique advantages of robotic system are expected to enhance safer and more precise surgical performance in near future. More experiences are mandatory to confirm real benefit of robot surgery in pancreatic disease.

Duplication of 7p: Further delineation of the phenotype and restriction of the critical region to the distal part of the short arm

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

Reish, O.; Berry, S.A.; King, R.A.

We report on a patient with duplication of 7p15{r_arrow}pter and review of the literature. Patients with partial duplication of the distal 7p, including only the distal segment 7p15{r_arrow}pter, have a syndrome comparable to that of patients with a larger or complete duplication of 7p. This suggests that the critical region for the dup(7p) phenotype is restricted to 7p15{r_arrow}pter. The complete clinical phenotype of dup (7)(p15{r_arrow}pter) includes mental retardation, skull anomalies, large anterior fontanel, cardiovascular defects, joint dislocation and contraction, and gastrointestinal and genital defects. Recognition of the clinical spectrum in patients with a smaller duplication 7p, and the assignment ofmore » this critical region, should prove valuable for accurate counseling, prediction of outcome, and further gene mapping. 33 refs., 3 figs., 2 tabs.« less

Mechanism of insulin fibrillation: the structure of insulin under amyloidogenic conditions resembles a protein-folding intermediate.

PubMed

Hua, Qing-xin; Weiss, Michael A

2004-05-14

Insulin undergoes aggregation-coupled misfolding to form a cross-beta assembly. Such fibrillation has long complicated its manufacture and use in the therapy of diabetes mellitus. Of interest as a model for disease-associated amyloids, insulin fibrillation is proposed to occur via partial unfolding of a monomeric intermediate. Here, we describe the solution structure of human insulin under amyloidogenic conditions (pH 2.4 and 60 degrees C). Use of an enhanced sensitivity cryogenic probe at high magnetic field avoids onset of fibrillation during spectral acquisition. A novel partial fold is observed in which the N-terminal segments of the A- and B-chains detach from the core. Unfolding of the N-terminal alpha-helix of the A-chain exposes a hydrophobic surface formed by native-like packing of the remaining alpha-helices. The C-terminal segment of the B-chain, although not well ordered, remains tethered to this partial helical core. We propose that detachment of N-terminal segments makes possible aberrant protein-protein interactions in an amyloidogenic nucleus. Non-cooperative unfolding of the N-terminal A-chain alpha-helix resembles that observed in models of proinsulin folding intermediates and foreshadows the extensive alpha --> beta transition characteristic of mature fibrils.

Stent-thrombus interaction and the influence of aspiration on mechanical thrombectomy: evaluation of different stent retrievers in a circulation model.

PubMed

Madjidyar, Jawid; Hermes, Julian; Freitag-Wolf, Sandra; Jansen, Olav

2015-08-01

Different devices and techniques are available for endovascular treatment of ischemic stroke. In this in vitro study, we examined the stent-thrombus interaction and the influence of additional aspiration on the efficiency of mechanical thrombectomy with established stent retrievers. Human blood thrombi were made in a Chandler loop. The thrombi were placed into the middle cerebral artery of a vascular silicon phantom. A programmable piston pump was used to acquire physiological flow in the model. Resistances were interposed to gain physiological pressure. The stent retrievers Trevo, Solitaire FR, Separator 3D, and Aperio were used to perform thrombectomy under direct visual control. For the additional aspiration, we used intermediate catheters. Ten attempts per device were made with and without aspiration under standardized conditions, a total of n = 80. For all thrombectomy maneuvers, it was demonstrated that the thrombus was pushed by the stent struts against the vessel wall and was retracted along it. The stent-thrombus interaction was only superficial for all devices. Using additional distal aspiration, the amount of distal embolism and rate of embolism in new territories was significantly lower than without. Moreover, additional aspiration reduced the number of recanalization maneuvers and the recanalization time. Distal aspiration with intermediate catheters increases the efficacy of mechanical thrombectomy with stent retrievers significantly. In contrary to earlier suggestions, the interaction between the thrombus and the stent retriever is only superficial, rather than an integration of the thrombus into the retriever. No significant differences between the proven devices could be shown in our model.

Distribution and Characterisation of Goblet Cells in the Large Intestine of Ostriches during the Pre- and Post-Hatch Period.

PubMed

Duritis, I; Mugurevics, A

2016-12-01

The role of goblet cell secretion, containing mucopolysaccharides, in the formation of a protective barrier of intestinal mucosa and transportation of the intestinal content has been described quite extensively. However, information on the quality composition of mucopolysaccharides and its changes in the intestinal tract of ostrich chicks, especially in the large intestinal segments, is unavailable. In the current study, ostrich embryos/chicks (n = 6/36) of both sexes were used shortly before hatching and during the first months of the post-hatch period. Tissues for histology were taken from the large intestine: the medium segments of the caecum, proximal and distal parts of colon. By using histochemical reactions, the differentiation of goblet cells as well as chemical composition of mucopolysaccharides was carried out. The cells contained acid (AB+), neutral (PAS+) and mixed (AB/PAS+) mucopolysaccharides. The number of goblet cells in the large intestine per unit area of mucosa increased towards the cloaca, and it was the highest in the distal part of the colon. The qualitative goblet cell composition in different large intestinal parts was different in all ages. In the caecum, goblet cells containing acid and mixed mucopolysaccharides dominate post-hatch, whereas in the colon, goblet cells containing acid mucopolysaccharides predominated. The most rapid changes in the qualitative goblet cell composition occur during the first week post-hatch when in all the intestinal segments the proportion of cells containing acid mucopolysaccharides continuously increased. © 2015 Blackwell Verlag GmbH.

Mutation of the MAP kinase DYF-5 affects docking and undocking of kinesin-2 motors and reduces their speed in the cilia of Caenorhabditis elegans

PubMed Central

Burghoorn, Jan; Dekkers, Martijn P. J.; Rademakers, Suzanne; de Jong, Ton; Willemsen, Rob; Jansen, Gert

2007-01-01

In the cilia of the nematode Caenorhabditis elegans, anterograde intraflagellar transport (IFT) is mediated by two kinesin-2 complexes, kinesin II and OSM-3 kinesin. These complexes function together in the cilia middle segments, whereas OSM-3 alone mediates transport in the distal segments. Not much is known about the mechanisms that compartmentalize the kinesin-2 complexes or how transport by both kinesins is coordinated. Here, we identify DYF-5, a conserved MAP kinase that plays a role in these processes. Fluorescence microscopy and EM revealed that the cilia of dyf-5 loss-of-function (lf) animals are elongated and are not properly aligned into the amphid channel. Some cilia do enter the amphid channel, but the distal ends of these cilia show accumulation of proteins. Consistent with these observations, we found that six IFT proteins accumulate in the cilia of dyf-5(lf) mutants. In addition, using genetic analyses and live imaging to measure the motility of IFT proteins, we show that dyf-5 is required to restrict kinesin II to the cilia middle segments. Finally, we show that, in dyf-5(lf) mutants, OSM-3 moves at a reduced speed and is not attached to IFT particles. We propose that DYF-5 plays a role in the undocking of kinesin II from IFT particles and in the docking of OSM-3 onto IFT particles. PMID:17420466

Localization of Mg2+-sensing shark kidney calcium receptor SKCaR in kidney of spiny dogfish, Squalus acanthias.

PubMed

Hentschel, Hartmut; Nearing, Jacqueline; Harris, H William; Betka, Marlies; Baum, Michelle; Hebert, Steven C; Elger, Marlies

2003-09-01

We recently cloned a homologue of the bovine parathyroid calcium receptor from the kidney of a spiny dogfish (Squalus acanthias) and termed this new protein SKCaR. SKCaR senses alterations in extracellular Mg2+ after its expression in human embryonic kidney cells (Nearing J, Betka M, Quinn S, Hentschel H, Elger M, Baum M, Bai M, Chattopadyhay N, Brown E, Hebert S, and Harris HW. Proc Natl Acad. Sci USA 99: 9231-9236, 2002). In this report, we used light and electron microscopic immunocytochemical techniques to study the distribution of SKCaR in dogfish kidney. SKCaR antiserum bound to the apical membranes of shark kidney epithelial cells in the following tubular segments: proximal tubules (PIa and PIIb), late distal tubule, and collecting tubule/collecting duct as well as diffusely labeled cells of early distal tubule. The highly specific distribution of SKCaR in mesial tissue as well as lateral countercurrent bundles of dogfish kidney is compatible with a role for SKCaR to sense local tubular Mg2+ concentrations. This highly specific distribution of SKCaR protein in dogfish kidney could possibly work in concert with the powerful Mg2+ secretory system present in the PIIa segment of elasmobranch fish kidney to affect recycling of Mg2+ from putative Mg2+-sensing/Mg2+-reabsorbing segments. These data provide support for the possible existence of Mg2+ cycling in elasmobranch kidney in a manner analogous to that described for mammals.

[Intramedullary nailing of the distal tibia illustrated with the Expert(TM) tibia nail].

PubMed

El Attal, R; Hansen, M; Rosenberger, R; Smekal, V; Rommens, P M; Blauth, M

2011-12-01

Restoration of axis, length, and rotation of the lower leg. Sufficient primary stability of the osteosynthesis for functional aftercare and to maintain joint mobility. Good bony healing in closed and open fractures. Closed and open fractures of the tibia and complete lower leg fractures distal to the isthmus (AO 42), extraarticular fractures of the distal tibia (AO 43 A1/A2/A3), segmental fractures of the tibia with a fracture in the distal tibia, and certain intraarticular fractures of the distal tibia without impression of the joint line with the use of additional implants (AO 43 C1) Patient in reduced general condition (e.g., bed ridden), flexion of the knee of less than 90°, patients with knee arthroplasty of the affected leg, infection in the area of the nail's insertion, infection of the tibial cavity, complex articular fractures of the proximal or distal tibia with joint depression. Closed reduction of the fracture preferably on a fracture table or using a distractor or an external fixation frame. If necessary, use pointed reduction clamps or sterile drapery. In some cases, additional implants like percutaneous small fragment screws, poller screws or k-wires are helpful. Open reduction is rarely necessary and must be avoided. Opening of the proximal tibia in line with the medullary canal. Canulated insertion of the Expert(TM) tibia nail (ETN; Synthes GmbH, Oberdorf, Switzerland) with reaming of the medullary canal. Control of axis, length, and rotation. Distal interlocking with the radiolucent drill and proximal interlocking with the targeting device. Immediate mobilization of ankle and knee joint. Mobilization with 20 kg weight-bearing with crutches. X-ray control 6 weeks postoperatively and increased weight-bearing depending on the fracture status. In cases with simple fractures, good bony contact, or transverse fracture pattern, full weight-bearing at the end of week 6 is targeted. Between July 2004 and May 2005, 180 patients were included in a multicenter study. The follow-up rate was 81% after 1 year. Of these, 91 fractures (50.6%) were located in the distal third of the tibia. In this segment, the rate of delayed union was 10.6%. Malalignment of > 5° was observed in 5.4%. A secondary malalignment after initial good reduction was detected in only 1.1% of all cases. The implant-specific risk for screw breakage was 3.2%. One patient sustained a deep infection. If additional fibula plating was performed an 8-fold higher risk for delayed bone healing was observed (95%CI: 2.9-21.2, p< 0.001). If the fracture of the fibula was at the same height as on the tibia, the risk for delayed healing was even 14-fold (95% CI: 3.4-62.5, p< 0.001). Biomechanically plating of the fibula does not increase stability in suprasyndesmal distal tibia-fibular fractures treated with an intramedullary nail. Using the ETN with its optimized locking options, fibula plating is not recommended, thus, avoiding soft tissue problems and potentially delayed bone healing.

Chimeric NP Non Coding Regions between Type A and C Influenza Viruses Reveal Their Role in Translation Regulation

PubMed Central

Crescenzo-Chaigne, Bernadette; Barbezange, Cyril; Frigard, Vianney; Poulain, Damien; van der Werf, Sylvie

2014-01-01

Exchange of the non coding regions of the NP segment between type A and C influenza viruses was used to demonstrate the importance not only of the proximal panhandle, but also of the initial distal panhandle strength in type specificity. Both elements were found to be compulsory to rescue infectious virus by reverse genetics systems. Interestingly, in type A influenza virus infectious context, the length of the NP segment 5′ NC region once transcribed into mRNA was found to impact its translation, and the level of produced NP protein consequently affected the level of viral genome replication. PMID:25268971

Two-level noncontiguous versus three-level anterior cervical discectomy and fusion: a biomechanical comparison.

PubMed

Finn, Michael A; Samuelson, Mical M; Bishop, Frank; Bachus, Kent N; Brodke, Darrel S

2011-03-15

Biomechanical study. To determine biomechanical forces exerted on intermediate and adjacent segments after two- or three-level fusion for treatment of noncontiguous levels. Increased motion adjacent to fused spinal segments is postulated to be a driving force in adjacent segment degeneration. Occasionally, a patient requires treatment of noncontiguous levels on either side of a normal level. The biomechanical forces exerted on the intermediate and adjacent levels are unknown. Seven intact human cadaveric cervical spines (C3-T1) were mounted in a custom seven-axis spine simulator equipped with a follower load apparatus and OptoTRAK three-dimensional tracking system. Each intact specimen underwent five cycles each of flexion/extension, lateral bending, and axial rotation under a ± 1.5 Nm moment and a 100-Nm axial follower load. Applied torque and motion data in each axis of motion and level were recorded. Testing was repeated under the same parameters after C4-C5 and C6-C7 diskectomies were performed and fused with rigid cervical plates and interbody spacers and again after a three-level fusion from C4 to C7. Range of motion was modestly increased (35%) in the intermediate and adjacent levels in the skip fusion construct. A significant or nearly significant difference was reached in seven of nine moments. With the three-level fusion construct, motion at the infra- and supra-adjacent levels was significantly or nearly significantly increased in all applied moments over the intact and the two-level noncontiguous construct. The magnitude of this change was substantial (72%). Infra- and supra-adjacent levels experienced a marked increase in strain in all moments with a three-level fusion, whereas the intermediate, supra-, and infra-adjacent segments of a two-level fusion experienced modest strain moments relative to intact. It would be appropriate to consider noncontiguous fusions instead of a three-level fusion when confronted with nonadjacent disease.

Mirror-symmetric duplicated chromosome 21q with minor proximal deletion, and with neocentromere in a child without the classical Down syndrome phenotype.

PubMed

Barbi, G; Kennerknecht, I; Wöhr, G; Avramopoulos, D; Karadima, G; Petersen, M B

2000-03-13

We report on a mentally retarded child with multiple minor anomalies and an unusually rearranged chromosome 21. This der(21) chromosome has a deletion of 21p and of proximal 21q, whereas the main portion of 21q is duplicated leading to a mirror-symmetric appearance with the mirror axis at the breakpoint. The centromere is only characterized by a secondary constriction (with a centromeric index of a G chromosome) at an unexpected distal position, but fluorescence in situ hybridization (FISH) with either chromosome specific or with all human centromeres alpha satellite DNA shows no cross hybridization. Thus, the marker chromosome represents a further example of an "analphoid marker with neocentromere." Molecular analysis using polymorphic markers on chromosome 21 verified a very small monosomic segment of the proximal long arm of chromosome 21, and additionally trisomy of the remaining distal segment. Although trisomic for almost the entire 21q arm, our patient shows no classical Down syndrome phenotype, but only a few minor anomalies found in trisomy 21 and in monosomy of proximal 21q, respectively. Copyright 2000 Wiley-Liss, Inc.

Homozygosity mapping of the gene for Chediak-Higashi syndrome to chromosome 1q42-q44 in a segment of conserved synteny that includes the mouse beige locus (bg)

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

Fukai, Kazuyoshi; Oh, Jangsuk; Karim, M.A.

Chediak-Higashi syndrome (CHS) is an autosomal recessive disorder characterized by hypopigmentation or oculocutaneous albinism and severe immunologic deficiency with neutropenia and lack of natural killer (NK) cell function. Most patients die in childhood from pyogenic infections or an unusual lymphoma-like condition. A hallmark of the disorder is giant inclusion bodies seen in all granule-containing cells, including granulocytes, lymphocytes, melanocytes, mast cells, and neurons. Similar ultrastructural abnormalities occur in the beige mouse, which thus has been suggested to be homologous to human CHS. High-resolution genetic mapping has indicated that the bg gene region of mouse chromosome 13 is likely homologous tomore » the distal portion of human chromosome 1q. Accordingly, we carried out homozygosity mapping using markers derived from distal human chromosome 1q in four inbred families or probands with CHS. Our results indicate that the human CHS gene maps to an 18.8-cM interval in chromosome segment 1q42-q44 and that human CHS therefore is very likely homologous to mouse bg. 43 refs., 2 figs.« less

Sonographic evaluation of peripheral nerves in subtypes of Guillain-Barré syndrome.

PubMed

Mori, Atsuko; Nodera, Hiroyuki; Takamatsu, Naoko; Maruyama-Saladini, Keiko; Osaki, Yusuke; Shimatani, Yoshimitsu; Kaji, Ryuji

2016-05-15

Sonography of peripheral nerves can depict alteration of nerve sizes that could reflect inflammation and edema in inflammatory and demyelinating neuropathies. Guillain-Barré syndrome (GBS). Information on sonographic comparison of an axonal subtype (acute motor [and sensory] axonal neuropathy [AMAN and AMSAN]) and a demyelinating subtype (acute inflammatory demyelinating polyneuropathy [AIDP]) has been sparse. Sonography of peripheral nerves and cervical nerve roots were prospectively recorded in patients with GBS who were within three weeks of disease onset. Five patients with AIDP and nine with AMAN (n=6)/AMSAN (n=3) were enrolled. The patients with AIDP showed evidence of greater degrees of demyelination (e.g., slower conduction velocities and increased distal latencies) than those with AMAN/AMSAN. The patients with AIDP tended to show enlarged nerves in the proximal segments and in the cervical roots, whereas the patients with AMAN/AMSAN had greater enlargement in the distal neve segment, especially in the median nerve (P = 0.03; Wrist-axilla cross-sectional ratio). In this small study, two subtypes of GBS showed different patterns of involvement that might reflect different pathomechanisms. Copyright © 2016 Elsevier B.V. All rights reserved.

De novo direct duplication of chromosome segment 22q11.2-q13.1

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

Fujimoto, Atsuko; Lin, Ming S.

Lindsay et al. [1995] reported a case of de novo duplication of the segment 22q11-q12. Molecular cytogenetics studies showed that the segment includes the regions responsible for the {open_quotes}cat eye,{close_quotes} DiGeorge, and velo-cardio-facial syndrome, and extends distal to the breakpoint cluster region. The phenotype was milder than that of complete trisomy 22 and der(22)t(11;22) (q23;q11) syndrome and was similar in type and severity to that of {open_quotes}cat eye{close_quotes} syndrome (CES). They suggested that trisomy of gene(s) responsible for the CES might have a predominant phenotypic effect over other genes present in the region duplicated in their patient. 3 refs., 2more » figs.« less

A 3D generic inverse dynamic method using wrench notation and quaternion algebra.

PubMed

Dumas, R; Aissaoui, R; de Guise, J A

2004-06-01

In the literature, conventional 3D inverse dynamic models are limited in three aspects related to inverse dynamic notation, body segment parameters and kinematic formalism. First, conventional notation yields separate computations of the forces and moments with successive coordinate system transformations. Secondly, the way conventional body segment parameters are defined is based on the assumption that the inertia tensor is principal and the centre of mass is located between the proximal and distal ends. Thirdly, the conventional kinematic formalism uses Euler or Cardanic angles that are sequence-dependent and suffer from singularities. In order to overcome these limitations, this paper presents a new generic method for inverse dynamics. This generic method is based on wrench notation for inverse dynamics, a general definition of body segment parameters and quaternion algebra for the kinematic formalism.

[The accuracy of rapid equilibrium assumption in steady-state enzyme kinetics is the function of equilibrium segment structure and properties].

PubMed

Vrzheshch, P V

2015-01-01

Quantitative evaluation of the accuracy of the rapid equilibrium assumption in the steady-state enzyme kinetics was obtained for an arbitrary mechanism of an enzyme-catalyzed reaction. This evaluation depends only on the structure and properties of the equilibrium segment, but doesn't depend on the structure and properties of the rest (stationary part) of the kinetic scheme. The smaller the values of the edges leaving equilibrium segment in relation to values of the edges within the equilibrium segment, the higher the accuracy of determination of intermediate concentrations and reaction velocity in a case of the rapid equilibrium assumption.

Sequential cloning of chromosomes

DOEpatents

Lacks, S.A.

1995-07-18

A method for sequential cloning of chromosomal DNA of a target organism is disclosed. A first DNA segment homologous to the chromosomal DNA to be sequentially cloned is isolated. The first segment has a first restriction enzyme site on either side. A first vector product is formed by ligating the homologous segment into a suitably designed vector. The first vector product is circularly integrated into the target organism`s chromosomal DNA. The resulting integrated chromosomal DNA segment includes the homologous DNA segment at either end of the integrated vector segment. The integrated chromosomal DNA is cleaved with a second restriction enzyme and ligated to form a vector-containing plasmid, which is replicated in a host organism. The replicated plasmid is then cleaved with the first restriction enzyme. Next, a DNA segment containing the vector and a segment of DNA homologous to a distal portion of the previously isolated DNA segment is isolated. This segment is then ligated to form a plasmid which is replicated within a suitable host. This plasmid is then circularly integrated into the target chromosomal DNA. The chromosomal DNA containing the circularly integrated vector is treated with a third, retrorestriction (class IIS) enzyme. The cleaved DNA is ligated to give a plasmid that is used to transform a host permissive for replication of its vector. The sequential cloning process continues by repeated cycles of circular integration and excision. The excision is carried out alternately with the second and third enzymes. 9 figs.

Which patients risk segmental kyphosis after short segment thoracolumbar fracture fixation with intermediate screws?

PubMed

Formica, Matteo; Cavagnaro, Luca; Basso, Marco; Zanirato, Andrea; Felli, Lamberto; Formica, Carlo; Di Martino, Alberto

2016-10-01

The use of intermediate screws in fractured vertebrae has been proposed to decrease the number of fused levels in thoracolumbar fractures and to enable short fixations. The aim of this study was to evaluate the results of this technique and to establish predictive factors involved in loss of segmental kyphosis correction (LKC). Forty-three patients who underwent short-segment spinal fixation with intermediate screws for a thoracolumbar spine fracture in a two-year time period were enrolled in the study. Patients had AO-type A3, A4 and B2 thoracolumbar fractures. Radiological parameters included segmental kyphosis (SK), vertebral wedge angle (VWA) and loss of anterior and posterior vertebral body height. Patients were evaluated up to one-year follow-up. The correlation between LKC and potential risk factors, such as smoking habit, sex, age, neurological status and BMI was evaluated. Mean preoperative SK was 16.5°±6.5°, and it decreased to 3.4°±3.5° postoperatively (P<0.01). At the one-year follow-up mean SK dropped to 5.5°±3.9° (P<0.01). Mean preoperative VWA was 20.0°±8.1°, and significantly improved to 6.3°±3.1° after surgery (P<0.01). There was a mean LKC of 1.8°±2.1°at one year. LKC mildly correlated with body mass index (BMI, r: +0.31), and obese patients (BMI>30) had an increased risk of LKC at the one-year follow-up (P=0.03; odds ratio [OR]=3.2). Analysis of the radiological data at one-year follow-up showed that all the evaluated parameters were associated with a mild loss of correction, with no impact on the clinical outcomes or implant failure. These findings confirm the trends reported in the literature. The correlation between LKC and clinical features, such as BMI, age, sex, smoking habit and preoperative neurological status was investigated. Interestingly, a positive correlation was observed between BMI and LKC, and obese patients with BMI>30 had an increased risk of LKC at one-year follow-up (OR 3.2); to our knowledge this finding has never before been reported. Short-segment fixation with intermediate screws is a viable technique with positive clinical and radiological outcomes at one-year follow-up. However, surgeons should be aware that in obese patients (BMI>30) this technique is associated with an increased risk of LKC. 3. Copyright © 2016 Elsevier Ltd. All rights reserved.

The distribution of near-axis seamounts at intermediate spreading ridges

NASA Astrophysics Data System (ADS)

Howell, J. K.; Bohnenstiehl, D. R.; White, S. M.; Supak, S. K.

2008-12-01

The ridge axes along the intermediate-spreading rate Galapagos Spreading Center (GSC, 46-56 mm/yr) and South East Indian Ridge (SEIR, 72-76 mm/yr) vary from rifted axial valleys to inflated axial highs independent of spreading rate. The delivery and storage of melt is believed to control axial morphology, with axial highs typically observed in areas underlain by a shallow melt lens and axial valleys in areas without a significant melt lens [e.g., Baran et al., 2005 G-cubed; Detrick et al. 2002 G-cubed]. To investigate a possible correlation between the style of seafloor volcanism and axial morphology, a closed contour algorithm is used to identify near axis (2.5km off axis) semi-circular seamounts of heights greater than 20m from shipboard multibeam bathymetry. In areas characterized by an axial high, more seamounts are formed at the ends of the segments than in the center. This is consistent with observations at fast-spreading ridges and suggests a tendency of lavas to erupt at lower effusion rates near second-order segment boundaries. Segments with a rift valley along the GSC show the opposite trend, with more seamounts at the center of second-order segments. Both patterns however are observed along SEIR segments with rift valleys where magma supply may be reflected in size and not their abundance.

Clinical utility of time-resolved imaging of contrast kinetics (TRICKS) magnetic resonance angiography for infrageniculate arterial occlusive disease.

PubMed

Mell, Matthew; Tefera, Girma; Thornton, Frank; Siepman, David; Turnipseed, William

2007-03-01

The diagnostic accuracy of magnetic resonance angiography (MRA) in the infrapopliteal arterial segment is not well defined. This study evaluated the clinical utility and diagnostic accuracy of time-resolved imaging of contrast kinetics (TRICKS) MRA compared with digital subtraction contrast angiography (DSA) in planning for percutaneous interventions of popliteal and infrapopliteal arterial occlusive disease. Patients who underwent percutaneous lower extremity interventions for popliteal or tibial occlusive disease were identified for this study. Preprocedural TRICKS MRA was performed with 1.5 Tesla (GE Healthcare, Waukesha, Wis) magnetic resonance imaging scanners with a flexible peripheral vascular coil, using the TRICKS technique with gadodiamide injection. DSA was performed using standard techniques in angiography suite with a 15-inch image intensifier. DSA was considered the gold standard. The MRA and DSA were then evaluated in a blinded fashion by a radiologist and a vascular surgeon. The popliteal artery and tibioperoneal trunk were evaluated separately, and the tibial arteries were divided into proximal, mid, and distal segments. Each segment was interpreted as normal (0% to 49% stenosis), stenotic (50% to 99% stenosis), or occluded (100%). Lesion morphology was classified according to the TransAtlantic Inter-Society Consensus (TASC). We calculated concordance between the imaging studies and the sensitivity and specificity of MRA. The clinical utility of MRA was also assessed in terms of identifying arterial access site as well as predicting technical success of the percutaneous treatment. Comparisons were done on 150 arterial segments in 30 limbs of 27 patients. When evaluated by TASC classification, TRICKS MRA correlated with DSA in 83% of the popliteal and in 88% of the infrapopliteal segments. MRA correctly identified significant disease of the popliteal artery with a sensitivity of 94% and a specificity of 92%, and of the tibial arteries with a sensitivity of 100% and specificity of 84%. When used to evaluate for stenosis vs occlusion, MRA interpretation agreed with DSA 90% of the time. Disagreement occurred in 15 arterial segments, most commonly in distal tibioperoneal arteries. MRA misdiagnosed occlusion for stenosis in 11 of 15 segments, and stenosis for occlusion in four of 15 segments. Arterial access was accurately planned based on preprocedural MRA findings in 29 of 30 patients. MRA predicted technical success 83% of the time. Five technical failures were due to inability to cross arterial occlusions, all accurately identified by MRA. TRICKS MRA is an accurate method of evaluating patients for popliteal and infrapopliteal arterial occlusive disease and can be used for planning percutaneous interventions.

Comparative study of Hsp27, GSK3β, Wnt1 and PRDX3 in Hirschsprung's disease.

PubMed

Gao, Hong; Liu, Xiaomei; Chen, Dong; Lv, Liangying; Wu, Mei; Mi, Jie; Wang, Weilin

2014-06-01

Hirschsprung's disease (HSCR) is a developmental disorder of the enteric nervous system characterized by aganglionosis in distal gut. In this study, we used two-dimensional gel electrophoresis (2-DE) technology coupled with matrix assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) analysis to identify differentially expressed proteins in the aganglionic (stenotic) and ganglionic (normal) colon segment tissues from patients with HSCR. We identified 15 proteins with different expression levels between the stenotic and the normal colon segment tissues from patients with HSCR. Nine proteins were upregulated and six proteins downregulated in the stenotic colon segment tissues compared to the normal colon segment tissues. Based on the biological functions, we selected the Hsp27 upregulated proteins and the PRDX3 downregulated proteins to confirm their expression in 20 patients. The protein and mRNA expressions of Hsp27 were statistically higher in the stenotic colon segment tissues than in the normal colon segment tissues, whereas the protein and mRNA expressions of PRDX3 were statistically lower in the stenotic colon segment tissues than in the normal colon segment tissues. These findings of changes in mRNA and protein in tissues from patients with HSCR provide information which may be helpful in understanding the pathomechanism that is implicated in the disease. © 2014 The Authors. International Journal of Experimental Pathology © 2014 International Journal of Experimental Pathology.

Some ultrastructural characteristics of the renal artery and abdominal aorta in the rat.

PubMed Central

Osborne-Pellegrin, M J

1978-01-01

The rat renal artery and abdominal aorta have been studied by light and electron microscopy. In rats of 200 g body weight the extracellular space in aortic media ranges between 50-60% and that of the distal renal artery between 15-25%. The surface to volume ratio of aortic smooth muscle cells is 2.7 micron2/micron3 compared to 1.6 micron2/micron3 in the distal renal artery. Dense bodies are rare in aortic smooth muscle cells but are abundant in those of the distal renal artery. Other ultrastructural details of the smooth muscle cells are similar in the two types of artery. Cell-to-cell contacts consist of simple apposition of plasm membranes and their number is proportional to the total length of cell membrane profile. Mitochondria represent 7-8% of the cell volume in both arteries. The proximal renal artery shows structural characteristics which are intermediate between those of the aorta and distal renal artery. In all renal arteries examined, bands of longitudinal smooth muscle are present in the adventitia, principally at branch points. In older rats, regions of discontinuity of the internal elastic lamina have been observed. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 PMID:640965

Document segmentation via oblique cuts

NASA Astrophysics Data System (ADS)

Svendsen, Jeremy; Branzan-Albu, Alexandra

2013-01-01

This paper presents a novel solution for the layout segmentation of graphical elements in Business Intelligence documents. We propose a generalization of the recursive X-Y cut algorithm, which allows for cutting along arbitrary oblique directions. An intermediate processing step consisting of line and solid region removal is also necessary due to presence of decorative elements. The output of the proposed segmentation is a hierarchical structure which allows for the identification of primitives in pie and bar charts. The algorithm was tested on a database composed of charts from business documents. Results are very promising.

Pharmacological and histological examinations of regional differences of guinea-pig lung: a role of pleural surface smooth muscle in lung strip contraction.

PubMed Central

Wong, W. S.; Bloomquist, S. L.; Bendele, A. M.; Fleisch, J. H.

1992-01-01

1. Parenchymal lung strip preparations have been widely used as an in vitro model of peripheral airway smooth muscle. The present study examined functional responses of 4 consecutive guinea-pig lung parenchymal strips isolated from the central region (segment 1) to the distal edge (segment 4) of the lower lung lobe. The middle two segments were designated as segments 2 and 3. 2. Lung segments 1 and 4 exhibited significantly greater contraction than the other 2 segments to KCl when responses were expressed as mg force per mg tissue weight. Contractile responses to bronchospastic agents including histamine, carbachol, endothelin-1, leukotrienes (LT) B4 and D4, and the thromboxane A2-mimetic U46619 demonstrated no significant difference in EC50 values among the 4 lung segments. 3. Contractile responses of segments 1 and 4 to antigen-challenge (ovalbumin), ionophore A23187 and substance P were significantly greater than the other 2 segments with respect to either sensitivity or maximum responsiveness. 4. U46619-induced contractions of the 4 lung segments were relaxed in similar manner by papaverine and theophylline up to 100%, salbutamol up to 80%, and sodium nitroprusside by only 20%. In contrast, sodium nitroprusside markedly reversed U46619-induced contraction of pulmonary arterial rings and bronchial rings. 5. Histological studies identified 2-4 layers of smooth muscle cells underlying the lung pleural surface. Mast cells were prominent in this area. Moreover, morphometric studies showed that segment 4 possessed the least amount of smooth muscle structures from bronchial/bronchiolar wall and vasculatures as compared to the other 3 segments, and a significant difference in this respect was evident between segment 1 and segment 4.(ABSTRACT TRUNCATED AT 250 WORDS) Images Figure 1 Figure 6 PMID:1378341

Fitting Handled Objects into Apertures by 17- to 36-Month-Old Children: The Dynamics of Spatial Coordination

ERIC Educational Resources Information Center

Jung, Wendy P.; Kahrs, Björn A.; Lockman, Jeffrey J.

2018-01-01

Handled artifacts are ubiquitous in human technology, but how young children engage in spatially coordinated behaviors with these artifacts is not well understood. To address this issue, children (N = 30) from 17-36 months were studied with motion tracking technology as they fit the distal segment of a handled artifact into a slot. The handle was…

Grapevines petioles are more sensitive to drought induced embolism than stems: evidence from in vivo MRI and microCT observations of hydraulic vulnerability segmentation

USDA-ARS?s Scientific Manuscript database

The concept ‘‘hydraulic vulnerability segmentation’’ represents a mechanism in which expendable distal organs (e.g. leaves attached to a woody shoot) are more susceptible to water-stress induced cavitation than the main stem of the plant. In the present work we present the first in-vivo observation ...

Botulinum Toxin Type A Injections in the Psoas Muscle of Children with Cerebral Palsy: Muscle Atrophy after Motor End Plate-Targeted Injections

ERIC Educational Resources Information Center

Van Campenhout, Anja; Verhaegen, Ann; Pans, Steven; Molenaers, Guy

2013-01-01

MEP targeting during BoNT-A injections has been demonstrated to improve outcome. Two injection techniques of the psoas muscle--proximal MEP targeting versus a widely used more distal injection technique--are compared using muscle volume assessment by digital MRI segmentation as outcome measure. Method: 7 spastic diplegic children received…

Three-dimensional magnetic resonance imaging of physeal injury: reliability and clinical utility.

PubMed

Lurie, Brett; Koff, Matthew F; Shah, Parina; Feldmann, Eric James; Amacker, Nadja; Downey-Zayas, Timothy; Green, Daniel; Potter, Hollis G

2014-01-01

Injuries to the physis are common in children with a subset resulting in an osseous bar and potential growth disturbance. Magnetic resonance imaging allows for detailed assessment of the physis with the ability to generate 3-dimensional physeal models from volumetric data. The purpose of this study was to assess the interrater reliability of physeal bar area measurements generated using a validated semiautomated segmentation technique and to highlight the clinical utility of quantitative 3-dimensional (3D) physeal mapping in pediatric orthopaedic practice. The Radiology Information System/Picture Archiving Communication System (PACS) at our institution was searched to find consecutive patients who were imaged for the purpose of assessing a physeal bar or growth disturbance between December 2006 and October 2011. Physeal segmentation was retrospectively performed by 2 independent operators using semiautomated software to generate physeal maps and bar area measurements from 3-dimensional spoiled gradient recalled echo sequences. Inter-reliability was statistically analyzed. Subsequent surgical management for each patient was recorded from the patient notes and surgical records. We analyzed 24 patients (12M/12F) with a mean age of 11.4 years (range, 5-year to 15-year olds) and 25 physeal bars. Of the physeal bars: 9 (36%) were located in the distal tibia; 8 (32%) in the proximal tibia; 5 (20%) in the distal femur; 1 (4%) in the proximal femur; 1 (4%) in the proximal humerus; and 1 (4%) in the distal radius. The independent operator measurements of physeal bar area were highly correlated with a Pearson correlation coefficient (r) of 0.96 and an intraclass correlation coefficient for average measures of 0.99 (95% confidence interval, 0.97-0.99). Four patients underwent resection of the identified physeal bars, 9 patients were treated with epiphysiodesis, and 1 patient underwent bilateral tibial osteotomies. Semiautomated segmentation of the physis is a reproducible technique for generating physeal maps and accurately measuring physeal bars, providing quantitative and anatomic information that may inform surgical management and prognosis in patients with physeal injury. Level IV.

Further investigation of the effects of 5-hydroxytryptamine, 8-OH-DPAT and DOI to mediate contraction and relaxation responses in the intestine and emesis in Suncus murinus.

PubMed

Javid, Farideh A; Afshin-Javid, Saeed; Horn, Charles C

2018-02-15

5-HT receptors are implicated in many gastrointestinal disorders. However, the precise role of 5-HT in mediating GI responses in Suncus murnius is still unclear. Therefore in this study, the effects of 5-HT and its agonists were investigated in Suncus. The involvement of 5-HT 2C receptors in mediating emesis was also investigated. The ability of 5-HT and its agonists/antagonists at 5-HT 1A and 5-HT 2 to modify GI motility was investigated in vitro and in vivo. WAY100635 (a 5-HT 1A antagonist) inhibited the contraction response to 5-HT in the proximal segments without affecting the maximum response; whilst enhancing the contraction to 5-HT (>30.0nM) in the distal intestine. The selective 5-HT 2A and 5-HT 2B receptor antagonists MDL-100907 and RS-127445 attenuated 5-HT-induced contractions (<10.0µM) in the distal segments. RS-127445 also attenuated 5-HT-induced contractions in the central segments. The selective 5-HT 2C receptor antagonist SB-242084, attenuated the responses to 5-HT (> 3.0nM) in the proximal and central but not the distal regions. 8-OH-DPAT-induced relaxation was resistant to the antagonism by 5-HT 1A/7 antagonists. DOI in the presence of 5-HT 1A/2A/2B/2C antagonists induced greater contraction responses (>1.0µM) in most tissues, whilst RS-127445, or SB-242084, reduced the responses to DOI (< 1.0µM) in some tissues. SB-242084 also suppressed emesis-induced by motion and intragastric CuSO 4 . In conclusion, within different regions of intestine, 5-HT 2 receptors are differently involved in contraction and emetic responses and that 8-OH-DPAT induces relaxation via non-5-HT 1A/7 receptors. Suncus could provide a model to investigate these diverse actions of 5-HT. Copyright © 2018 Elsevier B.V. All rights reserved.

MR angiography of the renal artery: comparison of breath-hold two-dimensional phase-contrast cine technique with the phased-array coil and breath-hold two-dimensional time-of-flight technique with the body coil.

PubMed

Masui, T; Takehara, Y; Igarashi, T; Ichijo, K; Takahashi, M; Kaneko, M; Nozaki, A

1997-07-01

Breath-hold 2D phase-contrast (PC) cine MR angiography with a phased-array coil and 2D time-of-flight (TOF) MR angiography were performed in the renal arteries and their findings were compared. Breath-hold 2D thin slice PC and TOF MR angiography were performed in 10 normal volunteers for renal arteries. A PC technique with k-space segmentation was utilized with the phased-array coil. A PC technique provided visualization of the renal artery more distally than a TOF technique (4.8 +/- 0.5 cm vs. 3.7 +/- 0.8 cm). With cardiac triggering, distal renal arteries were well demonstrated in PC MR angiography. On PC images, up- or downward movements of the mid to distal renal arteries with aortic pulsatility were recognized. The quality of the images was better with the PC than with the TOF technique (3.4 vs. 2.7). The mid to distal portions of the renal arteries translationally move with aortic pulsatility. To consistently visualize and evaluate them on MR angiography, cardiac triggering might be required to reduce the effects of pulsatile motions of the renal artery in the use of a phased-array coil.

Distal 22q11.2 microduplication encompassing the BCR gene.

PubMed

Descartes, Maria; Franklin, Judy; Diaz de Ståhl, Teresita; Piotrowski, Arkadiusz; Bruder, Carl E G; Dumanski, Jan P; Carroll, Andrew J; Mikhail, Fady M

2008-12-01

Chromosome 22 band q11.2 has been recognized to be highly susceptible to subtle microdeletions and microduplications, which have been attributed to the presence of several large segmental duplications; also known as low copy repeats (LCRs). These LCRs function as mediators of non-allelic homologous recombination (NAHR), which results in these chromosomal rearrangements as a result of unequal crossover. The four centromeric LCRs at proximal 22q11.2 have been previously implicated in recurrent chromosomal rearrangements including the DiGeorge/Velocardiofacial syndrome (DG/VCFs) microdeletion and its reciprocal microduplication. Recently, we and others have demonstrated that the four telomeric LCRs at distal 22q11.2 are causally implicated in a newly recognized recurrent distal 22q11.2 microdeletion syndrome in the region immediately telomeric to the DG/VCFs typically deleted region. Here we report on the clinical, cytogenetic, and array CGH studies of a 4.5-year-old girl with history of failure to thrive, developmental delay (DD), and relative macrocephaly. She carries a paternally inherited approximately 2.1 Mb microduplication at distal 22q11.2, which spans approximately 34 annotated genes, and is flanked by two of the four telomeric 22q11.2 LCRs. We conclude that the four telomeric LCRs at distal 22q11.2 can mediate both deletions and duplications in this genomic region. Both deletions and duplication of this region present with subtle clinical features including mild to moderate mental retardation, DD, and mild dysmorphic features. Copyright (c) 2008 Wiley-Liss, Inc.

Geometric morphometric analysis reveals age-related differences in the distal femur of Europeans.

PubMed

Cavaignac, Etienne; Savall, Frederic; Chantalat, Elodie; Faruch, Marie; Reina, Nicolas; Chiron, Philippe; Telmon, Norbert

2017-12-01

Few studies have looked into age-related variations in femur shape. We hypothesized that three-dimensional (3D) geometric morphometric analysis of the distal femur would reveal age-related differences. The purpose of this study was to show that differences in distal femur shape related to age could be identified, visualized, and quantified using three-dimensional (3D) geometric morphometric analysis. Geometric morphometric analysis was carried out on CT scans of the distal femur of 256 subjects living in the south of France. Ten landmarks were defined on 3D reconstructions of the distal femur. Both traditional metric and geometric morphometric analyses were carried out on these bone reconstructions. These analyses were used to identify trends in bone shape in various age-based subgroups (<40, 40-60, >60). Only the average bone shape of the < 40-year subgroup was statistically different from that of the other two groups. When the population was divided into two subgroups using 40 years of age as a threshold, the subject's age was correctly assigned 80% of the time. Age-related differences are present in this bone segment. This reliable, accurate method could be used for virtual autopsy and to perform diachronic and interethnic comparisons. Moreover, this study provides updated morphometric data for a modern population in the south of France. Manufacturers of knee replacement implants will have to adapt their prosthesis models as the population evolves over time.

Histopathologic observations of anorectal abnormalities in anal atresia.

PubMed

Meier-Ruge, W A; Holschneider, A M

2000-01-01

Over the years from 1992 to 1997, 41 anorectal malformations (ARM) with histopathologic alterations were investigated to determine which morphologic abnormalities of the distal rectum accompany ARMs. Three other cases showed normal neuromuscular morphology; 9 further cases could not be evaluated owing to scanty biopsies. All resected specimens were caudocranially coiled and cryostat cut at -20 degrees C into serial sections, which were stained with a lactic dehydrogenase, succinic dehydrogenase, nitroxide synthase, and acetylcholinesterase reaction as well as hemalum and sirius red. Ten low, 15 intermediate, and 10 high forms of anal atresia (AA) were studied. In addition, six cloacal abnormalities were investigated. In 7 cases (17%) (5 intermediate, 2 low AAs), the characteristics of Hirschsprung's disease were observed. Oligoneuronal hypoganglionosis of the myenteric plexus proximal to the anal floor was diagnosed in 7 AAs (12%). In 10 children with high-type AA and resection of 1-5 cm distal rectum and in all cloacal anomalies (n = 6) defects of the muscularis propria were seen in the rectal-atresia sac. These defects were characterized by hypoplasia of the circular-muscle layer and/or the internal anal sphincter (IAS). Intestinal neuronal dysplasia of the submucous plexus was most frequently observed (12%) in high-type AA. A correlation between innervation anomalies or anomalies of the muscularis propria and the type of fistula could not be seen. In conclusion, all cases with high-type AA and cloacal anomalies were characterized by anomalies of the muscularis propria and/or IAS but this was not the case in intermediate and low-type AAs. Anomalies of the enteric nervous system were diagnosed in 60% of AAs.

Composite drill pipe

DOEpatents

Leslie, James C [Fountain Valley, CA; Leslie, II, James C.; Heard, James [Huntington Beach, CA; Truong, Liem , Josephson; Marvin, Neubert [Huntington Beach, CA; Hans, [Anaheim, CA

2008-12-02

A composite pipe segment is formed to include tapered in wall thickness ends that are each defined by opposed frustoconical surfaces conformed for self centering receipt and intimate bonding contact within an annular space between corresponding surfaces of a coaxially nested set of metal end pieces. The distal peripheries of the nested end pieces are then welded to each other and the sandwiched and bonded portions are radially pinned. The composite segment may include imbedded conductive leads and the axial end portions of the end pieces are shaped to form a threaded joint with the next pipe assembly that includes a contact ring in one pipe assembly pierced by a pointed contact in the other to connect the corresponding leads across the joint.

Reimplantation of the resected tumour-bearing segment after recycling using liquid nitrogen for osteosarcoma.

PubMed

Abdel Rahman, Mohamed; Bassiony, Ayman; Shalaby, Hisham

2009-10-01

Reconstruction after en block resection of malignant tumours is still the subject of debate. We questioned the effectiveness of reconstruction by reimplanting the tumour-bearing segment after recycling in liquid nitrogen. Ten patients with osteosarcoma around the knee were included, with a mean age of 21 years. The operative technique included wide en bloc excision, debridement, and management of the resected segment with liquid nitrogen followed by reimplantation and internal fixation. At a mean follow-up of 4.5 years there was no local or systemic recurrence and the mean functional score was 82.4%. The frozen graft united proximally and distally in all but one patient in a period ranging from six to ten months. The effectiveness of this reconstruction technique in properly selected patients with osteosarcoma is comparable to other techniques of biological reconstruction with the added benefit of being simple, cheap and durable.

Relationship between the posterior cerebral artery and the cisternal segment of the oculomotor nerve.

PubMed

Uz, Aysun; Tekdemir, Ibrahim

2006-12-01

The aim of this study was to evaluate the relationship between the cisternal segment of the oculomotor nerve and the posterior cerebral artery and its branches. The oculomotor nerve and the posterior cerebral artery of 15 cadaver brains (30 hemispheres) were examined using a surgical microscope. The dorsal portion of the cisternal segment of the oculomotor nerve had a close relationship with the P(1) and P(2) segments of the posterior cerebral artery in 100% of cases, the thalamoperforating arteries in 97%, the collicular arteries in 97%, the short circumferential arteries in 33% and the posterior medial choroidal arteries in 20%. The proximal portion of the nerve had a close relationship with the P(1) segment of the posterior cerebral artery, the thalamoperforating arteries, the collicular arteries and the short circumferential arteries, whereas the distal portion had a close relationship with the P(2) segment of the posterior cerebral artery and the posterior medial choroidal arteries. The oculomotor nerve was perforated by various arteries in different portions. These arteries were the thalamoperforating arteries in 10% of the hemispheres, the collicular arteries in 16% and the short circumferential arteries in 11%. It can be concluded that the dorsal portion of the cisternal segment of the oculomotor nerve has a close relationship with the branches arising from the P(1) and P(2) segments of the posterior cerebral artery. These arteries supply the cisternal segment of the oculomotor nerve.

Biomechanical Assessment of the Dorsal Spanning Bridge Plate in Distal Radius Fracture Fixation: Implications for Immediate Weight-Bearing.

PubMed

Huang, Jerry I; Peterson, Bret; Bellevue, Kate; Lee, Nicolas; Smith, Sean; Herfat, Safa

2017-04-01

The goal of this study was to compare the biomechanical stability of a 2.4-mm dorsal spanning bridge plate with a volar locking plate (VLP) in a distal radius fracture model, during simulated crutch weight-bearing. Five paired cadaveric forearms were tested. A 1-cm dorsal wedge osteotomy was created to simulate an unstable distal radius fracture with dorsal comminution. Fractures were fixed with a VLP or a dorsal bridge plate (DBP). Specimens were mounted to a crutch handle, and optical motion-tracking sensors were attached to the proximal and distal segments. Specimens were loaded in compression at 1 mm/s on a servohydraulic test frame until failure, defined as 2 mm of gap site displacement. The VLP construct was significantly more stable to axial load in a crutch weight-bearing model compared with the DBP plate (VLP: 493 N vs DBP: 332 N). Stiffness was higher in the VLP constructs, but this was not statistically significant (VLP: 51.4 N/mm vs DBP: 32.4 N/mm). With the crutch weight-bearing model, DBP failed consistently with wrist flexion and plate bending, whereas VLP failed with axial compression at the fracture site and dorsal collapse. Dorsal spanning bridge plating is effective as an internal spanning fixator in treating highly comminuted intra-articular distal radius fracture and prevents axial collapse at the radiocarpal joint. However, bridge plating may not offer advantages in early weight-bearing or transfer in polytrauma patients, with less axial stability in our crutch weight-bearing model compared with volar plating. A stiffer 3.5-mm DBP or use of a DBP construct without the central holes may be considered for distal radius fractures if the goal is early crutch weight-bearing through the injured extremity.

Outcome of Repair of Distal Radial and Ulnar Fractures in Dogs Weighing 4 kg or Less Using a 1.5-mm Locking Adaption Plate or 2.0-mm Limited Contact Dynamic Compression Plate.

PubMed

Nelson, Thomas A; Strom, Adam

2017-11-01

Objectives  Retrospective evaluation of repairing distal radial and ulnar fractures in small breed dogs with the Synthes 1.5-mm locking Adaption plate system and compare results in a similar group of patients repaired with the Synthes 2.0-mm limited contact-dynamic compression plate (LC-DCP). Methods  Electronic medical records from one specialty referral centre were reviewed from March 21, 2010, to October 9, 2015, for patients weighing less than or equal to 4 kg that had a distal one-third radial and ulnar fracture repaired with a Synthes 1.5-mm locking adaption plate or Synthes 2.0-mm LC-DCP. Further inclusion criteria included application of the plate to the cranial surface of the radius via open reduction and internal fixation. Results  Six 1.5-mm Adaption plates and 7 2.0-mm LC-DCPs were used to repair 13 distal radial and ulnar fractures in 12 dogs. There were three major complications in the 1.5-mm adaption plate group (one plate fracture, one screw pull-out and one fracture through a distal screw hole) and one major complication in the 2.0-mm LC-DCP group due to a re-fracture. All patients without a complication had good or excellent functional outcome. Clinical Significance  The authors recommend that the 1.5-mm Adaption plate be used only when a 2.0-mm LC-DCP would not allow for a minimum of two screws in the distal segment and at the discretion of the surgeon. Schattauer GmbH Stuttgart.

Impact of gender on infarct size, ST-segment resolution, myocardial blush and clinical outcomes after primary stenting for acute myocardial infarction: Substudy from the EMERALD trial.

PubMed

Ng, Vivian G; Mori, Ken; Costa, Ricardo A; Kish, Mitra; Mehran, Roxana; Urata, Hidenori; Saku, Keijiro; Stone, Gregg W; Lansky, Alexandra J

2016-03-15

Women with AMI may have worse outcomes than men. However, it is unclear if this is related to differences in treatment, treatment effect or gender specific factors. We sought to determine whether primary percutaneous intervention (PCI) has a differential impact on infarct size, myocardial perfusion and ST segment resolution in men and women with acute myocardial infarction (AMI). A total of 501 AMI patients were prospectively enrolled in the EMERALD study and underwent PCI with or without distal protection. Post hoc gender subset analysis was performed. 501 patients (108 women, 393 men) with ST-segment elevation AMI presenting within 6h underwent primary (or rescue) PCI with stenting and a distal protection device. Women were older, had more hypertension, less prior AMI, smaller BSA, and smaller vessel size, but had similar rates of diabetes (30% versus 20.2%, p=0.87), LAD infarct, and time-to-reperfusion compared to men. Women more frequently had complete ST-resolution (>70%) at 30days (72.8% versus 59.8%, p=0.02), and smaller infarct size compared to males (12.2±19.6% versus 18.4±18.5%, p=0.006). At 6months, TLR (6.9% versus 5.2%) and MACE (11.4% versus 10.3%) were similar for women and men. Despite worse comorbidities, women with AMI treated with primary PCI with stenting showed similar early and midterm outcomes compared to men. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Crystalline polyoxometalate (POM)–polyethylene glycol (PEG) composites aimed as non-humidified intermediate-temperature proton conductors

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

Tsuboi, Masaki; Hibino, Mitsuhiro; Mizuno, Noritaka

2016-02-15

Crystalline polyoxometalate (POM)–polyethylene glycol (PEG) composites aimed as non-humidified intermediate-temperature proton conductors were synthesized and characterized by single crystal and powder XRD, solid state MASNMR, and TG-DTA measurements. Among the POM–PEG composites, Cs{sub 2.7}H{sub 0.3}[PW{sub 12}O{sub 40}]·1.2PEG1000 (CsHPW-PEG1000) possessed one-dimensional channels with diameters of ca. 6 and 8 Å, where PEG probably resided, and showed the best performance as a proton conductor (1.2×10{sup −5} S cm{sup −1} at 443 K). Proton conductivities of POM–PEG composites decreased by the increase in molecular weights of PEG (CsHPW-PEG12,000) or anion charges (CsHSiW-PEG1000). Variable contact time {sup 13}C-CP (cross polarization) MASNMR revealed that localmore » mobility (i.e., segmental motion) of PEG is related to the trends in proton conductivities. These results show that amount of acidic protons (H{sup +}) is not the primary factor in proton conduction and that segmental motion of PEG assists the proton hopping among POMs in the crystal lattice of POM–PEG composites. - Graphical abstract: Non-humidified intermediate-temperature proton conduction in crystalline polyoxometalate (POM)–polyethylene (PEG) composites are assisted by the segmental motion of PEG. - Highlights: • Crystalline polyoxometalate–polyethlene glycol (PEG) composites were synthesized. • CsHPW-PEG1000 possessed one-dimensional channels and showed the highest proton conductivity. • {sup 13}C CPMASNMR revealed that segmental motion of PEG is related to the proton conduction.« less

Anatomical Assessment of the Temporopolar Artery for Revascularization of Deep Recipients.

PubMed

Tayebi Meybodi, Ali; Benet, Arnau; Griswold, Dylan; Dones, Flavia; Preul, Mark C; Lawton, Michael T

2018-05-30

Intracranial-intracranial and extracranial-intracranial bypass options for revascularization of deep cerebral recipients are limited and technically demanding. To assess the anatomical feasibility of using the temporopolar artery (TPA) for revascularization of the anterior cerebral artery (ACA), posterior cerebral artery (PCA), and superior cerebellar arteries (SCA). Orbitozygomatic craniotomy was performed bilaterally on 8 cadaveric heads. The cisternal segment of the TPA was dissected. The TPA was cut at M3-M4 junction with its proximal and distal calibers and the length of the cisternal segment measured. Feasibility of the TPA-A1-ACA, TPA-A2-ACA, TPA-SCA, and TPA-PCA bypasses were assessed. A total of 17 TPAs were identified in 16 specimens. The average distal TPA caliber was 1.0 ± 0.2 mm, and the average cisternal length was 37.5 ± 9.4 mm. TPA caliber was ≥ 1.0 mm in 12 specimens (70%). The TPA-A1-ACA bypass was feasible in all specimens, whereas the TPA reached the A2-ACA, SCA, and PCA in 94% of specimens (16/17). At the point of anastomosis, the average recipient caliber was 2.5 ± 0.5 mm for A1-ACA, and 2.3 ± 0.7 mm for A2-ACA. The calibers of the SCA and PCA at the anastomosis points were 2.0 ± 0.6 mm, and 2.7 ± 0.8 mm, respectively. The TPA-ACA, TPA-PCA, and TPA-SCA bypasses are anatomically feasible and may be used when the distal caliber of the TPA stump is optimal to provide adequate blood flow. This study lays foundations for clinical use of the TPA for ACA revascularization in well-selected cases.

Methyl CpG level at distal part of heat-shock protein promoter HSP70 exhibits epigenetic memory for heat stress by modulating recruitment of POU2F1-associated nucleosome-remodeling deacetylase (NuRD) complex.

PubMed

Kisliouk, Tatiana; Cramer, Tomer; Meiri, Noam

2017-05-01

Depending on its stringency, exposure to heat in early life leads to either resilience or vulnerability to heat stress later in life. We hypothesized that epigenetic alterations in genes belonging to the cell proteostasis pathways are attributed to long-term responses to heat stress. Epigenetic regulation of the mRNA expression of the molecular chaperone heat-shock protein (HSP) 70 (HSPA2) was evaluated in the chick hypothalamus during the critical period of thermal-control establishment on day 3 post-hatch and during heat challenge on day 10. Both the level and duration of HSP70 expression during heat challenge a week after heat conditioning were more pronounced in chicks conditioned under harsh versus mild temperature. Analyzing different segments of the promoter in vitro indicated that methylation of a distal part altered its transcriptional activity. In parallel, DNA-methylation level of this segment in vivo was higher in harsh- compared to mild-heat-conditioned chicks. Hypermethylation of the HSP70 promoter in high-temperature-conditioned chicks was accompanied by a reduction in both POU Class 2 Homeobox 1 (POU2F1) binding and recruitment of the nucleosome remodeling deacetylase (NuRD) chromatin-remodeling complex. As a result, histone H3 acetylation levels at the HSP70 promoter were higher in harsh-temperature-conditioned chicks than in their mild-heat-conditioned counterparts. These results suggest that methylation level of a distal part of the HSP70 promoter and POU2F1 recruitment may reflect heat-stress-related epigenetic memory and may be useful in differentiating between individuals that are resilient or vulnerable to stress. © 2017 International Society for Neurochemistry.

Distribution of enkephalin-like immunoreactivity in the cat digestive tract.

PubMed

Bagnol, D; Henry, M; Cupo, A; Julé, Y

1997-05-12

Immunohistochemical investigations were carried out to determine the pattern of distribution of methionine- and leucine-enkephalin-like materials in the cat pylorus, duodenum, ileum and proximal and distal colon. The present results indicate that leucine-enkephalin-like materials are less densely distributed than methionine-enkephalin-like materials, but that the two patterns of distribution show some similarities. Considerable regional differences exist however in the distribution of these enkephalin-like materials in the muscular layers. In the duodenum, ileum and proximal colon, the immunoreactivity was mainly confined to the myenteric plexus and the circular muscle layer, where it was present in nerve cell bodies and in numerous fibres. In the longitudinal muscle and submucous layers, a few immunoreactive fibres were observed which sometimes surrounded blood vessels. In the pylorus and the distal colon, however, numerous immunoreactive fibres were observed in the longitudinal and circular muscle layers; the immunoreactivity was detected in the cell bodies of numerous myenteric plexus neurons but those of only a few submucous plexus neurons. In addition, the pylorus tissues contained immunoreactive plexi which were localized either within the longitudinal muscle or between the serosa and the longitudinal muscle layer. These plexi were connected to the myenteric plexus by immunoreactive nerve strands. In all the small intestinal segments studied, numerous immunoreactive varicosities were present in the deep muscular plexus, in the inner part of the circular muscle layer. Our results suggest that in cats, the nervous control of external muscular layers mediated by enkephalins shows regional differences. In the pylorus and the distal colon, it involves both the longitudinal and circular muscle layers, whereas in other intestinal segments, only the circular muscle layer is involved.

Noninvasive estimation of pharyngeal airway resistance and compliance in children based on volume-gated dynamic MRI and computational fluid dynamics.

PubMed

Persak, Steven C; Sin, Sanghun; McDonough, Joseph M; Arens, Raanan; Wootton, David M

2011-12-01

Computational fluid dynamics (CFD) analysis was used to model the effect of collapsing airway geometry on internal pressure and velocity in the pharyngeal airway of three sedated children with obstructive sleep apnea syndrome (OSAS) and three control subjects. Model geometry was reconstructed from volume-gated magnetic resonance images during normal tidal breathing at 10 increments of tidal volume through the respiratory cycle. Each geometry was meshed with an unstructured grid and solved using a low-Reynolds number k-ω turbulence model driven by flow data averaged over 12 consecutive breathing cycles. Combining gated imaging with CFD modeling created a dynamic three-dimensional view of airway anatomy and mechanics, including the evolution of airway collapse and flow resistance and estimates of the local effective compliance. The upper airways of subjects with OSAS were generally much more compliant during tidal breathing. Compliance curves (pressure vs. cross-section area), derived for different locations along the airway, quantified local differences along the pharynx and between OSAS subjects. In one subject, the distal oropharynx was more compliant than the nasopharynx (1.028 vs. 0.450 mm(2)/Pa) and had a lower theoretical limiting flow rate, confirming the distal oropharynx as the flow-limiting segment of the airway in this subject. Another subject had a more compliant nasopharynx (0.053 mm(2)/Pa) during inspiration and apparent stiffening of the distal oropharynx (C = 0.0058 mm(2)/Pa), and the theoretical limiting flow rate indicated the nasopharynx as the flow-limiting segment. This new method may help to differentiate anatomical and functional factors in airway collapse.

Micro-anatomy of the renal sympathetic nervous system: a human postmortem histologic study.

PubMed

Atherton, Daniel S; Deep, Nicholas L; Mendelsohn, Farrell O

2012-07-01

Hypertension remains an epidemic uncontrolled with pharmacologic therapies. A novel catheter inserted into the renal artery has been shown to lower blood pressure by ablating the renal sympathetic nerves with radiofrequency energy delivered through the arterial wall. We report a histologic study describing the anatomic substrate for this technique, specifically the renal sympathetic nervous system. Histological sections from proximal, middle, and distal renal artery segments from nine renal arteries (five human autopsies) were analyzed. Nerves were manually counted and their distance from the lumen-intima interface was measured using a micrometer. The nerves were then categorized by location into 0.5-mm-wide "rings" that were arranged circumferentially around the renal artery lumen. Of all nerves detected, 1.0% was in the 0-0.5 mm ring, 48.3% were in the 0.5-1.0 mm ring, 25.6% were in the 1.0-1.5 mm ring, 15.5% were in the 1.5-2.0 mm ring, and 9.5% were in the 2.0-2.5 mm ring. Beyond 0.5 mm, the proportion of nerves tended to decrease as the distance from the lumen increased. Totally, 90.5% of all nerves in this study existed within 2.0 mm of the renal artery lumen. Additionally, the number of nerves tended to increase along the length of the artery from proximal to distal segments (proximal = 216; middle = 323; distal = 417). In conclusion, our analysis indicates that a great proportion of renal sympathetic nerves have close proximity to the lumen-intima interface and should thus be accessible via renal artery interventional approaches such as catheter ablation. This data provides important anatomic information for the development of ablation and other type devices for renal sympathetic denervation. © 2011 Wiley Periodicals, Inc.

Segmental Bile Duct-Targeted Liver Resection for Right-Sided Intrahepatic Stones.

PubMed

Li, Shao-Qiang; Hua, Yun-Peng; Shen, Shun-Li; Hu, Wen-Jie; Peng, Bao-Gang; Liang, Li-Jian

2015-07-01

Hepatectomy is a safe and effective treatment for intrahepatic stones (IHSs). However, the resection plane for right-sided stones distributed within 2 segments is obstacle because of atrophy-hypertrophy complex formation of the liver and difficult dissection of segmental pedicle within the Glissonean plate by conventional approach. Thus, we devised segmental bile duct-targeted liver resection (SBDLR) for IHS, which aimed at completely resection of diseased bile ducts. This study aimed to evaluate the outcomes of SBDLR for right-sided IHSs. From January 2009 to December 2013, 107 patients with IHS treated by SBDLR in our center were reviewed in a prospective database. Patients' intermediate and long-term outcomes after SBDLR were analyzed. A total of 40 (37.4%) patients with localized right-sided stone and 67 (62.7%) patients with bilateral stones underwent SBDLR alone and SBDLR combined with left-sided hepatectomy, respectively. There was no hospital mortality of this cohort of patients. The postoperative morbidity was 35.5%. The mean intraoperative blood loss was 414  mL (range: 100-2500). Twenty-one (19.6%) patients needed red blood cells transfusion. The intermediate stone clearance rate was 94.4%; the final clearance rate reached 100% after subsequent postoperative cholangioscopic lithotomy. Only 2.8% patients developed stone recurrence in a median follow-up period of 38.3 months. SBDLR is a safe and effective treatment for right-sided IHS distributed within 2 segments. It is especially suitable for a subgroup of patients with bilateral stones whose right-sided stones are within 2 segments and bilateral liver resection is needed.

Hyperspectral image segmentation using a cooperative nonparametric approach

NASA Astrophysics Data System (ADS)

Taher, Akar; Chehdi, Kacem; Cariou, Claude

2013-10-01

In this paper a new unsupervised nonparametric cooperative and adaptive hyperspectral image segmentation approach is presented. The hyperspectral images are partitioned band by band in parallel and intermediate classification results are evaluated and fused, to get the final segmentation result. Two unsupervised nonparametric segmentation methods are used in parallel cooperation, namely the Fuzzy C-means (FCM) method, and the Linde-Buzo-Gray (LBG) algorithm, to segment each band of the image. The originality of the approach relies firstly on its local adaptation to the type of regions in an image (textured, non-textured), and secondly on the introduction of several levels of evaluation and validation of intermediate segmentation results before obtaining the final partitioning of the image. For the management of similar or conflicting results issued from the two classification methods, we gradually introduced various assessment steps that exploit the information of each spectral band and its adjacent bands, and finally the information of all the spectral bands. In our approach, the detected textured and non-textured regions are treated separately from feature extraction step, up to the final classification results. This approach was first evaluated on a large number of monocomponent images constructed from the Brodatz album. Then it was evaluated on two real applications using a respectively multispectral image for Cedar trees detection in the region of Baabdat (Lebanon) and a hyperspectral image for identification of invasive and non invasive vegetation in the region of Cieza (Spain). A correct classification rate (CCR) for the first application is over 97% and for the second application the average correct classification rate (ACCR) is over 99%.

New species of aquatic insects from Europe (Insecta: Trichoptera): Alps and Pyrenees as harbours of unknown biodiversity

PubMed Central

GRAF, WOLFRAM; VITECEK, SIMON; PREVIŠIĆ, ANA; MALICKY, HANS

2016-01-01

New species are described from the following genera: Consorophylax and Anisogamus, (Trichoptera, Limnephilidae). Additionally the larvae of the genus Anisogamus, and the larval stages of Anisogamus waringeri nov. sp. and A. difformis (McLachlan 1867) are described. The new species Consorophylax vinconi sp. nov. is a microendemic from the Southern Alps and differs distinctly from its congeners in the shape of the parameres, which are distinctly straitened in the distal quarter in the new species. The new species Anisogamus waringeri sp. nov. represents the second species in the hitherto monospecific genus Anisogamus. Compared to Anisogamus difformis, A. waringeri sp. nov. develops more slender superior appendages; a more rounded basal plate of the intermediate appendages, lacking pointed protuberances; and parameres shorter than the aedaegus, proximally with one dorsal and several ventral tines. Further, the two species are disjunctly distributed in the European mountain ranges (A. difformis: Alps, A. waringeri sp. nov.: Pyrenees). Larvae of the genus Anisogamus are characterized by the lack of a dorsal protuberance on the 1st abdominal segment, a unique feature among Limnephilidae. Anisogamus difformis and A. waringeri sp. nov. larvae differ in pronotum shape. The recovery of two new species demonstrates the significance of taxonomic studies in Europe, and the importance of adequate training for young scientists in order to assess a biodiversity under threat of extinction that has yet to be fully described. PMID:25661619

Translocation pathway of protein substrates in ClpAP protease

PubMed Central

Ishikawa, Takashi; Beuron, Fabienne; Kessel, Martin; Wickner, Sue; Maurizi, Michael R.; Steven, Alasdair C.

2001-01-01

Intracellular protein degradation, which must be tightly controlled to protect normal proteins, is carried out by ATP-dependent proteases. These multicomponent enzymes have chaperone-like ATPases that recognize and unfold protein substrates and deliver them to the proteinase components for digestion. In ClpAP, hexameric rings of the ClpA ATPase stack axially on either face of the ClpP proteinase, which consists of two apposed heptameric rings. We have used cryoelectron microscopy to characterize interactions of ClpAP with the model substrate, bacteriophage P1 protein, RepA. In complexes stabilized by ATPγS, which bind but do not process substrate, RepA dimers are seen at near-axial sites on the distal surface of ClpA. On ATP addition, RepA is translocated through ≈150 Å into the digestion chamber inside ClpP. Little change is observed in ClpAP, implying that translocation proceeds without major reorganization of the ClpA hexamer. When translocation is observed in complexes containing a ClpP mutant whose digestion chamber is already occupied by unprocessed propeptides, a small increase in density is observed within ClpP, and RepA-associated density is also seen at other axial sites. These sites appear to represent intermediate points on the translocation pathway, at which segments of unfolded RepA subunits transiently accumulate en route to the digestion chamber. PMID:11287666

SINGLE STRAND-CONTAINING REPLICATING MOLECULES OF CIRCULAR MITOCHONDRIAL DNA

PubMed Central

Wolstenholme, David R.; Koike, Katsuro; Cochran-Fouts, Patricia

1973-01-01

Mitochondrial DNAs (mtDNAs) from Chang rat solid hepatomas and Novikoff rat ascites hepatomas were examined in the electron microscope after preparation by the aqueous and by the formamide protein monolayer techniques. MtDNAs from both tumors were found to include double-forked circular molecules with a form and size suggesting they were replicative intermediates. These molecules were of two classes. In molecules of one class, all three segments were apparently totally double stranded. Molecules of the second class were distinguished by the fact that one of the segments spanning the region between the forks in which replication had occurred (the daughter segments) was either totally single stranded, or contained a single-stranded region associated with one of the forks. Daughter segments of both totally double-stranded and single strand-containing replicating molecules varied in length from about 3 to about 80% of the circular contour length of the molecule. Similar classes of replicating molecules were found in mtDNA from regenerating rat liver and chick embryos, indicating them to be normal intermediates in the replication of mtDNA All of the mtDNAs examined included partially single-stranded simple (nonforked) circular molecules. A possible scheme for the replication of mtDNA is presented, based on the different molecular forms observed PMID:4345165

Regulation of proximal-distal intercalation during limb regeneration in the axolotl (Ambystoma mexicanum).

PubMed

Satoh, Akira; Cummings, Gillian M C; Bryant, Susan V; Gardiner, David M

2010-12-01

Intercalation is the process whereby cells located at the boundary of a wound interact to stimulate proliferation and the restoration of the structures between the boundaries that were lost during wounding. Thus, intercalation is widely considered to be the mechanism of regeneration. When a salamander limb is amputated, the entire cascade of regeneration events is activated, and the missing limb segments and their boundaries (joints) as well as the structures within each segment are regenerated. Therefore, in an amputated limb it is not possible to distinguish between intersegmental regeneration (formation of new segments/joints) and intrasegmental regeneration (formation of structures within a given segment), and it is not possible to study the differential regulation of these two processes. We have used two models for regeneration that allow us to study these two processes independently, and report that inter- and intrasegmental regeneration are different processes regulated by different signaling pathways. New limb segments/joints can be regenerated from cells that dedifferentiate to form blastema cells in response to signaling that is mediated in part by fibroblast growth factor. © 2010 The Authors. Journal compilation © 2010 Japanese Society of Developmental Biologists.

High pressure capillary connector

DOEpatents

Renzi, Ronald F.

2005-08-09

A high pressure connector capable of operating at pressures of 40,000 psi or higher is provided. This connector can be employed to position a first fluid-bearing conduit that has a proximal end and a distal end to a second fluid-bearing conduit thereby providing fluid communication between the first and second fluid-bearing conduits. The connector includes (a) an internal fitting assembly having a body cavity with (i) a lower segment that defines a lower segment aperture and (ii) an interiorly threaded upper segment, (b) a first member having a first member aperture that traverses its length wherein the first member aperture is configured to accommodate the first fluid-bearing conduit and wherein the first member is positioned in the lower segment of the internal fitting assembly, and (c) a second member having a second member aperture that traverses its length wherein the second member is positioned in the upper segment of the fitting assembly and wherein a lower surface of the second member is in contact with an upper surface of the first member to assert a compressive force onto the first member and wherein the first member aperture and the second member aperture are coaxial.

Follow-up of coronary artery bypass graft patency: diagnostic efficiency of high-pitch dual-source 256-slice MDCT findings.

PubMed

Yuceler, Zeyneb; Kantarci, Mecit; Yuce, Ihsan; Kizrak, Yesim; Bayraktutan, Ummugulsum; Ogul, Hayri; Kiris, Adem; Celik, Omer; Pirimoglu, Berhan; Genc, Berhan; Gundogdu, Fuat

2014-01-01

Our aim was to evaluate the diagnostic accuracy of 256-slice, high-pitch mode multidetector computed tomography (MDCT) for coronary artery bypass graft (CABG) patency. Eighty-eight patients underwent 256-slice MDCT angiography to evaluate their graft patency after CABG surgery using a prospectively synchronized electrocardiogram in the high-pitch spiral acquisition mode. Effective radiation doses were calculated. We investigated the diagnostic accuracy of high-pitch, low-dose, prospective, electrocardiogram-triggering, dual-source MDCT for CABG patency compared with catheter coronary angiography imaging findings. A total of 215 grafts and 645 vessel segments were analyzed. All graft segments had diagnostic image quality. The proximal and middle graft segments had significantly (P < 0.05) better mean image quality scores (1.18 ± 0.4) than the distal segments (1.31 ± 0.5). Using catheter coronary angiography as the reference standard, high-pitch MDCT had the following sensitivity, specificity, positive predictive value, and negative predictive value of per-segment analysis for detecting graft patency: 97.1%, 99.6%, 94.4%, and 99.8%, respectively. In conclusion, MDCT can be used noninvasively with a lower radiation dose for the assessment of restenosis in CABG patients.

Chromosome Rearrangements That Involve the Nucleolus Organizer Region in Neurospora

PubMed Central

Perkins, D. D.; Raju, N. B.; Barry, E. G.; Butler, D. K.

1995-01-01

In ~3% of Neurospora crassa rearrangements, part of a chromosome arm becomes attached to the nucleolus organizer region (NOR) at one end of chromosome 2 (linkage group V). Investigations with one inversion and nine translocations of this type are reported here. They appear genetically to be nonreciprocal and terminal. When a rearrangement is heterozygous, about one-third of viable progeny are segmental aneuploids with the translocated segment present in two copies, one in normal position and one associated with the NOR. Duplications from many of the rearrangements are highly unstable, breaking down by loss of the NOR-attached segment to restore normal chromosome sequence. When most of the rearrangements are homozygous, attenuated strands can be seen extending through the unstained nucleolus at pachytene, joining the translocated distal segment to the remainder of chromosome 2. Although the rearrangements appear genetically to be nonreciprocal, molecular evidence shows that at least several of them are physically reciprocal, with a block of rDNA repeats translocated away from the NOR. Evidence that NOR-associated breakpoints are nonterminal is also provided by intercrosses between pairs of translocations that transfer different-length segments of the same donor-chromosome arm to the NOR. PMID:8582636

Comparison and assessment of semi-automatic image segmentation in computed tomography scans for image-guided kidney surgery.

PubMed

Glisson, Courtenay L; Altamar, Hernan O; Herrell, S Duke; Clark, Peter; Galloway, Robert L

2011-11-01

Image segmentation is integral to implementing intraoperative guidance for kidney tumor resection. Results seen in computed tomography (CT) data are affected by target organ physiology as well as by the segmentation algorithm used. This work studies variables involved in using level set methods found in the Insight Toolkit to segment kidneys from CT scans and applies the results to an image guidance setting. A composite algorithm drawing on the strengths of multiple level set approaches was built using the Insight Toolkit. This algorithm requires image contrast state and seed points to be identified as input, and functions independently thereafter, selecting and altering method and variable choice as needed. Semi-automatic results were compared to expert hand segmentation results directly and by the use of the resultant surfaces for registration of intraoperative data. Direct comparison using the Dice metric showed average agreement of 0.93 between semi-automatic and hand segmentation results. Use of the segmented surfaces in closest point registration of intraoperative laser range scan data yielded average closest point distances of approximately 1 mm. Application of both inverse registration transforms from the previous step to all hand segmented image space points revealed that the distance variability introduced by registering to the semi-automatically segmented surface versus the hand segmented surface was typically less than 3 mm both near the tumor target and at distal points, including subsurface points. Use of the algorithm shortened user interaction time and provided results which were comparable to the gold standard of hand segmentation. Further, the use of the algorithm's resultant surfaces in image registration provided comparable transformations to surfaces produced by hand segmentation. These data support the applicability and utility of such an algorithm as part of an image guidance workflow.

Molecular Profiles for Lung Cancer Pathogenesis and Detection in U.S. Veterans

DTIC Science & Technology

2014-12-01

airway epithelium [1, 6, 7], and 2) these changes can be detected and serve as biomarker for early detection of lung cancer [8, 9], in the current...biospecimens from seven locations: nasal epithelium , proximal and distal bronchial airway epithelium obtained at bronchoscopy (ipsilateral and...contralateral to the tumor) as well as the tumor/benign lesion, adjacent normal parenchyma, and sub- segmental bronchial epithelium at time of lobectomy

Balloon-assisted embolization of skull base meningioma with liquid embolic agent.

PubMed

Abdel Kerim, Amr; Bonneville, Fabrice; Jean, Betty; Cornu, Philippe; LeJean, Lise; Chiras, Jacques

2010-01-01

The authors report a novel technique of balloon-assisted embolization of a skull base meningioma supplied by a branch of the cavernous segment of the internal carotid artery using liquid embolic agent. A temporarily inflated balloon distal to the meningioma's feeding vessel may improve the access to this small branch and may reduce the chances of unintended reflux during delivery of the liquid embolic agent.

Contrast enema findings in patients presenting with poor functional outcome after primary repair for Hirschsprung disease.

PubMed

Garrett, Kevin M; Levitt, Marc A; Peña, Alberto; Kraus, Steven J

2012-09-01

The radiologic evaluation of Hirschsprung disease is well described in the literature. However, there is a paucity of literature describing the appearance of the neo-rectum and colon after repair, specifically describing findings in patients with poor functional outcome, which would suggest the need for reoperation. We describe findings on contrast enema and correlate them with surgical findings at reoperation in children with poor functional outcome after primary repair for Hirschsprung disease who suffer from bowel dysfunction that can manifest with either soiling or obstructive symptoms such as enterocolitis. Children were identified from our colorectal surgery database. At the time of abstract submission, 35 children had contrast enemas prior to reoperation. Additional children continue to present for evaluation. The majority of children included in the study had their primary repair performed elsewhere. The initial procedures included: Duhamel (n = 11), Soave (n = 20) or Swenson (n = 3). One child had undergone a primary Soave repair and subsequently had a Swenson-type reoperation but continued to have a poor outcome. One child's initial surgical repair could not be determined. Images were reviewed by a staff pediatric radiologist and a pediatric radiology fellow. Findings encountered on contrast enema in these children include a distal narrowed segment due to stricture or aganglionic/transitional zone segment (8), dilated/hypomotile distal segment (7), thickened presacral space due to compressing Soave cuff (11), dilated Duhamel pouch (8), active enterocolitis (3) and partially obstructing twist of the pull-through segment (1). Multiple anatomical and pathological complications exist that can lead to bowel dysfunction in children after repair of Hirschsprung disease. Little recent literature exists regarding the radiographic findings in children. We had the opportunity to review a substantial series of these children, describe the contrast enema findings in these difficult cases and correlate them with operative findings. Radiologic evaluation is key to assessing such patients; it defines the potential anatomical problem with the pull-through and facilitates surgical planning.

Addition of simethicone improves small bowel capsule endoscopy visualisation quality.

PubMed

Krijbolder, M S; Grooteman, K V; Bogers, S K; de Jong, D J

2018-01-01

Small bowel capsule endoscopy (SBCE) is an important diagnostic tool for small-bowel diseases but its quality may be hampered by intraluminal gas. This study evaluated the added value of the anti-foaming agent, simethicone, to a bowel preparation with polyethylene glycol (PEG) on the quality of small bowel visualisation and its use in the Netherlands. This was a retrospective, single-blind, cohort study. Patients in the PEG group only received PEG prior to SBCE. Patients in the PEG-S group ingested additional simethicone. Two investigators assessed the quality of small-bowel visualisation using a four-point scale for 'intraluminal gas' and 'faecal contamination'. By means of a survey, the use of anti-foaming agents was assessed in a random sample of 16 Dutch hospitals performing SBCE. The quality of small bowel visualisation in the PEG group (n = 33) was significantly more limited by intraluminal gas when compared with the PEG-S group (n = 31): proximal segment 83.3% in PEG group vs. 18.5% in PEG-S group (p < 0.01), distal segment 66.7% vs. 18.5% respectively (p < 0.01). No difference was observed in the amount of faecal contamination (proximal segment 80.0% PEG vs. 59.3% PEG-S, p = 0.2; distal segment 90.0% PEG vs. 85.2% PEG-S, p = 0.7), mean small bowel transit times (4.0 PEG vs. 3.9 hours PEG-S, p = 0.7) and diagnostic yield (43.3% PEG vs. 22.2% PEG-S, p = 0.16). Frequency of anti-foaming agent use in the Netherlands was low (3/16, 18.8%). Simethicone is of added value to a PEG bowel preparation in improving the quality of visualisation of the small bowel by reducing intraluminal gas. At present, the use of anti-foaming agents in SBCE preparation is not standard practice in the Netherlands.

Evidence for a systemic regulation of neurotrophin synthesis in response to peripheral nerve injury.

PubMed

Shakhbazau, Antos; Martinez, Jose A; Xu, Qing-Gui; Kawasoe, Jean; van Minnen, Jan; Midha, Rajiv

2012-08-01

Up-regulation of neurotrophin synthesis is an important mechanism of peripheral nerve regeneration after injury. Neurotrophin expression is regulated by a complex series of events including cell interactions and multiple molecular stimuli. We have studied neurotrophin synthesis at 2 weeks time-point in a transvertebral model of unilateral or bilateral transection of sciatic nerve in rats. We have found that unilateral sciatic nerve transection results in the elevation of nerve growth factor (NGF) and NT-3, but not glial cell-line derived neurotrophic factor or brain-derived neural factor, in the uninjured nerve on the contralateral side, commonly considered as a control. Bilateral transection further increased NGF but not other neurotrophins in the nerve segment distal to the transection site, as compared to the unilateral injury. To further investigate the distinct role of NGF in regeneration and its potential for peripheral nerve repair, we transduced isogeneic Schwann cells with NGF-encoding lentivirus and transplanted the over-expressing cells into the distal segment of a transected nerve. Axonal regeneration was studied at 2 weeks time-point using pan-neuronal marker NF-200 and found to directly correlate with NGF levels in the regenerating nerve. © 2012 The Authors. Journal of Neurochemistry © 2012 International Society for Neurochemistry.

Relationship of gastric Helicobacter pylori infection to Barrett’s esophagus and gastro-esophageal reflux disease in Chinese

PubMed Central

Zhang, Jun; Chen, Xiao-Li; Wang, Kang-Min; Guo, Xiao-Dan; Zuo, Ai-Li; Gong, Jun

2004-01-01

AIM: To evaluate the relationship of Helicobacter pylori infection to reflux esophagitis (RE), Barrett’s esophagus (BE) and gastric intestinal metaplasia (IM). METHODS: RE, BE and gastric IM were determined by upper endoscopy. Patients were divided into 2 groups; those with squamocolumnar junction (SCJ) beyond gastroesophageal junction (GEJ) ≥ 3 cm (group A), and those with SCJ beyond GEJ < 3 cm (group B). Biopsy specimens were obtained endoscopically from just below the SCJ, gastric antrum along the greater and lesser curvature. Pathological changes and H pylori infection were determined by HE staining, Alcian blue staining and Giemsa staining. RESULTS: The prevalence of H pylori infection was 46.93%. There was no difference in the prevalence between males and females. The prevalence of H pylori infection decreased stepwise significantly from RE grade I to III. There was no difference in the prevalence between the two groups, and between long-segment and short-segment BE. In distal stomach, prevalence of H pylori infection was significantly higher in patients with IM than those without IM. CONCLUSION: There is a protective role of H pylori infection to GERD. There may be no relationship between H pylori infection of stomach and BE. H pylori infection is associated with the development of IM in the distal stomach. PMID:14991936

Open segmental fracture of both bone forearm and dislocation of ipsilateral elbow with extruded middle segment radius

PubMed Central

Kumar, Pawan; Manjhi, Lal Bahadur; Rajak, Ramesh Lal

2013-01-01

Extruded middle segment of radius with open segmental fracture both bone forearm and dislocation of ipsilateral elbow is a rare injury. A 12-year-old child presented to us within 4 hours following fall from tree. The child's mother was carrying a 12-cm-long extruded soiled segment of radius. The extruded bone was thoroughly washed. The medullary cavity was properly syringed with antiseptic solution. The bone was autoclaved and put in the muscle plane of the distal forearm after debridement of the wound. After 5 days, a 2.5-mm K-wire was introduced by retrograde method into the proximal radius by passing through the extruded segment. Another 2.5-mm K-wire was passed in ulna. The limb was evaluated clinicoradiologically every 2 weeks. The wound was healed by primary intention. At 4 months, the reposed bone appeared less dense radiologically and K-wire seemed to be out of the bone. In the subsequent months, the roentgenograms show remodeling of the extruded fragment. After 20 weeks, the K-wires were removed (first ulnar and then radial). Complete union was achieved with full range of movement except loss of few degrees of extension of elbow and thumb. This case is reported to show a good outcome following successful incorporation of an extruded segment of radius in an open fracture. PMID:23798764

Suitability of cholinesterase of polychaete Diopatra neapolitana as biomarker of exposure to pesticides: In vitro characterization.

PubMed

Mennillo, Elvira; Casu, Valentina; Tardelli, Federica; De Marchi, Lucia; Freitas, Rosa; Pretti, Carlo

2017-01-01

Cholinesterases of Diopatra neapolitana were characterized for their activity in whole body and different body segments (apical, intermediate, posterior), substrate affinity (acetyl-, butyryl-, propionylthiocholine), kinetic parameters (K m and V max ) and in vitro response to model inhibitors (eserine hemisulfate, isoOMPA, BW284C51) and carbamates (carbofuran, methomyl, aldicarb and carbaryl). Results showed that the rate of hydrolysis for acetyl- and propionylthiocholine was higher in the posterior segment than the apical/intermediate segments and whole body. Cholinesterases of D. neapolitana showed a substrate preference for acetylthiocholine followed by propionylthiocholine; butyrylthioline was poorly hydrolyzed indicating, together with the absence of inhibition by the specific inhibitor and the absence of reactive bands in native electrophoresis, a lack of an active butyrylcholinesterase, differently than that observed in other Annelida species. The degree of inhibition by selected carbamates of cholinesterase activity with propionylthiocholine as substrate was higher than that observed with ATChI-ChE activity; aldicarb showed the highest inhibitory effect. Copyright © 2016 Elsevier Inc. All rights reserved.

Intermediate shocks in three-dimensional magnetohydrodynamic bow-shock flows with multiple interacting shock fronts

PubMed

De Sterck H; Poedts

2000-06-12

Simulation results of three-dimensional (3D) stationary magnetohydrodynamic (MHD) bow-shock flows around perfectly conducting spheres are presented. For strong upstream magnetic field a new complex bow-shock flow topology arises consisting of two consecutive interacting shock fronts. It is shown that the leading shock front contains a segment of intermediate 1-3 shock type. This is the first confirmation in 3D that intermediate shocks, which were believed to be unphysical for a long time, can be formed and can persist for small-dissipation MHD in a realistic flow configuration.

Method for implementation of recursive hierarchical segmentation on parallel computers

NASA Technical Reports Server (NTRS)

Tilton, James C. (Inventor)

2005-01-01

A method, computer readable storage, and apparatus for implementing a recursive hierarchical segmentation algorithm on a parallel computing platform. The method includes setting a bottom level of recursion that defines where a recursive division of an image into sections stops dividing, and setting an intermediate level of recursion where the recursive division changes from a parallel implementation into a serial implementation. The segmentation algorithm is implemented according to the set levels. The method can also include setting a convergence check level of recursion with which the first level of recursion communicates with when performing a convergence check.

Influence of Near-Segment Positioning in a Rotationally Asymmetric Multifocal Intraocular Lens.

PubMed

Song, In Seok; Yoon, Sam Young; Kim, Jae Yong; Kim, Myoung Joon; Tchah, Hungwon

2016-04-01

To compare visual performance and higher order aberrations (HOAs) based on the position of the near segment in eyes with rotationally asymmetric multifocal intraocular lenses (IOLs). Asymmetric multifocal IOLs (Lentis Mplus LS-313; Oculentis Optikgeräte GmbH, Wetzlar, Germany) were implanted with the near segment positioned either inferiorly, superiorly, or temporally. Uncorrected distance (UDVA), intermediate (UIVA), and near (UNVA) visual acuity, corrected distance visual acuity (CDVA), and distance-corrected intermediate (DCIVA) and near (DCNVA) visual acuity, contrast sensitivity, HOAs, and subjective symptom questionnaires were compared at 1 month postoperatively. Forty-five eyes from 45 patients were evaluated (n = 25, 9, and 11 eyes in the inferior, superior, and temporal groups, respectively). No significant differences in UDVA, UIVA, UNVA, CDVA, DCIVA, or DCNVA were found between the three groups (P > .05). The temporal group showed the best results in UDVA, CDVA, and DCNVA, but the inferior group showed the best results in DCIVA and UNVA and the superior group showed the best results in UIVA. Contrast sensitivity and the subjective symptom questionnaire also did not demonstrate any significant differences (P > .05). Total HOA and spherical aberration did not demonstrate any statistically significant differences (P > .05), but vertical coma and horizontal coma demonstrated significant differences based on near segment position (P < .001). The position of the near segment in eyes with rotationally asymmetric multifocal IOLs demonstrates no significant effect on visual performance. Copyright 2016, SLACK Incorporated.

Hunter-gatherer postcranial robusticity relative to patterns of mobility, climatic adaptation, and selection for tissue economy.

PubMed

Stock, J T

2006-10-01

Human skeletal robusticity is influenced by a number of factors, including habitual behavior, climate, and physique. Conflicting evidence as to the relative importance of these factors complicates our ability to interpret variation in robusticity in the past. It remains unclear how the pattern of robusticity in the skeleton relates to adaptive constraints on skeletal morphology. This study investigates variation in robusticity in claviculae, humeri, ulnae, femora, and tibiae among human foragers, relative to climate and habitual behavior. Cross-sectional geometric properties of the diaphyses are compared among hunter-gatherers from southern Africa (n = 83), the Andaman Islands (n = 32), Tierra del Fuego (n = 34), and the Great Lakes region (n = 15). The robusticity of both proximal and distal limb segments correlates negatively with climate and positively with patterns of terrestrial and marine mobility among these groups. However, the relative correspondence between robusticity and these factors varies throughout the body. In the lower limb, partial correlations between polar second moment of area (J(0.73)) and climate decrease from proximal to distal section locations, while this relationship increases from proximal to distal in the upper limb. Patterns of correlation between robusticity and mobility, either terrestrial or marine, generally increase from proximal to distal in the lower and upper limbs, respectively. This suggests that there may be a stronger relationship between observed patterns of diaphyseal hypertrophy and behavioral differences between populations in distal elements. Despite this trend, strength circularity indices at the femoral midshaft show the strongest correspondence with terrestrial mobility, particularly among males.

Acute inhibition of NCC does not activate distal electrogenic Na+ reabsorption or kaliuresis.

PubMed

Hunter, Robert W; Craigie, Eilidh; Homer, Natalie Z M; Mullins, John J; Bailey, Matthew A

2014-02-15

Na(+) reabsorption from the distal renal tubule involves electroneutral and electrogenic pathways, with the latter promoting K(+) excretion. The relative activities of these two pathways are tightly controlled, participating in the minute-to-minute regulation of systemic K(+) balance. The pathways are interdependent: the activity of the NaCl cotransporter (NCC) in the distal convoluted tubule influences the activity of the epithelial Na(+) channel (ENaC) downstream. This effect might be mediated by changes in distal Na(+) delivery per se or by molecular and structural adaptations in the connecting tubule and collecting ducts. We hypothesized that acute inhibition of NCC activity would cause an immediate increase in Na(+) flux through ENaC, with a concomitant increase in renal K(+) excretion. We tested this using renal clearance methodology in anesthetized mice, by the administration of hydrochlorothiazide (HCTZ) and/or benzamil (BZM) to exert specific blockade of NCC and ENaC, respectively. Bolus HCTZ elicited a natriuresis that was sustained for up to 110 min; urinary K(+) excretion was not affected. Furthermore, the magnitude of the natriuresis was no greater during concomitant BZM administration. This suggests that ENaC-mediated Na(+) reabsorption was not normally limited by Na(+) delivery, accounting for the absence of thiazide-induced kaliuresis. After dietary Na(+) restriction, HCTZ elicited a kaliuresis, but the natiuretic effect of HCTZ was not enhanced by BZM. Our findings support a model in which inhibition of NCC activity does not increase Na(+) reabsorption through ENaC solely by increasing distal Na(+) delivery but rather by inducing a molecular and structural adaptation in downstream nephron segments.

A new quantitative classification of ecological types in the bromeliad genus Tillandsia (Bromeliaceae) based on trichomes.

PubMed

Stefano, Mosti; Papini, Alessio; Brighigna, Luigi

2008-03-01

Using collection specimens, we measured the density and wing area of trichomes in 37 species of the bromeliad genus Tillandsia, specifically the abaxial proximal, abaxial distal, adaxial proximal and adaxial distal parts of the leaf. The product of the trichome "wing" area by the number of trichomes (means) produced a pure number (T) that was correlated to ecological features. The correlation was positive with respect to arid environments (xeric Tillands) and negative with respect to humid environments (mesic Tillands). Bulbous, and particularly myrmecophytic species and species with tanks, represented particular categories. Other intermediate types were identified based on the T number, totalling five ecological types. In comparison with other systems of ecological typification for Tillands and other Bromeliaceae, the present system offers measurable data whose analysis is reproducible.

Role of Reversible Histidine Coordination in Hydroxylamine Reduction by Plant Hemoglobins (Phytoglobins).

PubMed

Athwal, Navjot Singh; Alagurajan, Jagannathan; Andreotti, Amy H; Hargrove, Mark S

2016-10-18

Reduction of hydroxylamine to ammonium by phytoglobin, a plant hexacoordinate hemoglobin, is much faster than that of other hexacoordinate hemoglobins or pentacoordinate hemoglobins such as myoglobin, leghemoglobin, and red blood cell hemoglobin. The reason for differences in reactivity is not known but could be intermolecular electron transfer between protein molecules in support of the required two-electron reduction, hydroxylamine binding, or active site architecture favoring the reaction. Experiments were conducted with phytoglobins from rice, tomato, and soybean along with human neuroglobin and soybean leghemoglobin that reveal hydroxylamine binding as the rate-limiting step. For hexacoordinate hemoglobins, binding is limited by the dissociation rate constant for the distal histidine, while leghemoglobin is limited by an intrinsically low affinity for hydroxylamine. When the distal histidine is removed from rice phytoglobin, a hydroxylamine-bound intermediate is formed and the reaction rate is diminished, indicating that the distal histidine imidazole side chain is critical for the reaction, albeit not for electron transfer but rather for direct interaction with the substrate. Together, these results demonstrate that phytoglobins are superior at hydroxylamine reduction because they have distal histidine coordination affinity constants near 1, and facile rate constants for binding and dissociation of the histidine side chain. Hexacoordinate hemoglobins such as neuroglobin are limited by tighter histidine coordination that blocks hydroxylamine binding, and pentacoordinate hemoglobins have intrinsically lower hydroxylamine affinities.

Mitochondrial transcription terminator family members mTTF and mTerf5 have opposing roles in coordination of mtDNA synthesis.

PubMed

Jõers, Priit; Lewis, Samantha C; Fukuoh, Atsushi; Parhiala, Mikael; Ellilä, Simo; Holt, Ian J; Jacobs, Howard T

2013-01-01

All genomes require a system for avoidance or handling of collisions between the machineries of DNA replication and transcription. We have investigated the roles in this process of the mTERF (mitochondrial transcription termination factor) family members mTTF and mTerf5 in Drosophila melanogaster. The two mTTF binding sites in Drosophila mtDNA, which also bind mTerf5, were found to coincide with major sites of replication pausing. RNAi-mediated knockdown of either factor resulted in mtDNA depletion and developmental arrest. mTTF knockdown decreased site-specific replication pausing, but led to an increase in replication stalling and fork regression in broad zones around each mTTF binding site. Lagging-strand DNA synthesis was impaired, with extended RNA/DNA hybrid segments seen in replication intermediates. This was accompanied by the accumulation of recombination intermediates and nicked/broken mtDNA species. Conversely, mTerf5 knockdown led to enhanced replication pausing at mTTF binding sites, a decrease in fragile replication intermediates containing single-stranded segments, and the disappearance of species containing segments of RNA/DNA hybrid. These findings indicate an essential and previously undescribed role for proteins of the mTERF family in the integration of transcription and DNA replication, preventing unregulated collisions and facilitating productive interactions between the two machineries that are inferred to be essential for completion of lagging-strand DNA synthesis.

Mitochondrial Transcription Terminator Family Members mTTF and mTerf5 Have Opposing Roles in Coordination of mtDNA Synthesis

PubMed Central

Jõers, Priit; Lewis, Samantha C.; Fukuoh, Atsushi; Parhiala, Mikael; Ellilä, Simo; Holt, Ian J.; Jacobs, Howard T.

2013-01-01

All genomes require a system for avoidance or handling of collisions between the machineries of DNA replication and transcription. We have investigated the roles in this process of the mTERF (mitochondrial transcription termination factor) family members mTTF and mTerf5 in Drosophila melanogaster. The two mTTF binding sites in Drosophila mtDNA, which also bind mTerf5, were found to coincide with major sites of replication pausing. RNAi-mediated knockdown of either factor resulted in mtDNA depletion and developmental arrest. mTTF knockdown decreased site-specific replication pausing, but led to an increase in replication stalling and fork regression in broad zones around each mTTF binding site. Lagging-strand DNA synthesis was impaired, with extended RNA/DNA hybrid segments seen in replication intermediates. This was accompanied by the accumulation of recombination intermediates and nicked/broken mtDNA species. Conversely, mTerf5 knockdown led to enhanced replication pausing at mTTF binding sites, a decrease in fragile replication intermediates containing single-stranded segments, and the disappearance of species containing segments of RNA/DNA hybrid. These findings indicate an essential and previously undescribed role for proteins of the mTERF family in the integration of transcription and DNA replication, preventing unregulated collisions and facilitating productive interactions between the two machineries that are inferred to be essential for completion of lagging-strand DNA synthesis. PMID:24068965

Three-dimensional vasculature of the bovine liver.

PubMed

Shirai, W; Sato, T; Shibuya, H; Naito, K; Tsukise, A

2005-12-01

To clarify anatomical distribution of Fasciola infection, the vascular and ductal architectures of the liver were studied by means of corrosion cast technique using synthetic resin. The arteria hepatica propria (AP) passes as the arteria gastroduodenalis (AG); AP becomes the left trunk after the porta hepatis; AP passes on the right side of vena porta communis (VPC) and projects AG while curving in a U-shape below the portal vein. Hepatic veins located between the vena hepatica media (HM) and vena hepatica dextra (HD) varied widely among specimens and were irregular, including the vena hepatica dorso-lateralis sinistra (Hds), vena hepatica dorso-lateralis dextra (Hdd), vena hepatica lobi caudati (Hlc), venae hepaticae processus caudati (Hpc), venae hepaticae processus papillaris (Hpp), and the hepatic vein to the dorsal intermediate part, which directly or indirectly drained into the vena cava caudalis. The courses of the bovine hepatic veins were markedly diverse, and anastomoses between vena hepatica sinistra (HS) and Hds were observed in about a half of the livers. The portal vein entered the liver as VPC slightly above the centre of the right lobe on the visceral surface. The intermediate or transverse part [pars transversa trunci sinistri (PTS)] of truncus sinister (TS), which extends from the entry of the portal vein into the left lobe of the liver, was slightly arched downward [pars umbilicalis trunci sinistri (PUS)]. The portal vein further arched from the distal end of TS to the umbilical vein and ran towards the inter-lobar incision between the left lobe and quadrate lobe. Based on these branches, hepatic segments were determined as 13 or 14 areas. A total of 15 bile ducts were derived from various lobes. The hepatic duct was about 2.6-6 cm long from the confluence of the right and left hepatic ducts to the division of the cystic duct and the common hepatic duct.

Hybrid assistive systems for rehabilitation: lessons learned from functional electrical therapy in hemiplegics.

PubMed

Popović, Dejan B; Popović, Mirjana B

2006-01-01

This paper suggests that the optimal method for promoting of the recovery of upper extremity function in hemiplegic individuals is the use of hybrid assistive systems (HAS). The suggested HAS is a combination of stimulation of paralyzed distal segments (hand) in synchrony with robot controlled movements of proximal segments (upper arm and forearm). The use of HAS is envisioned as part of voluntary activation of preserved sensory-motor systems during task related exercise. This HAS design follows our results from functional electrical therapy, constraint induced movement therapy, intensive exercise therapy, and use of robots for rehabilitation. The suggestion is also based on strong evidences that cortical plasticity is best promoted by task related exercise and patterned electrical stimulation.

Recuperator construction for a gas turbine engine

DOEpatents

Kang, Yungmo; McKeirnan, Jr., Robert D.

2006-12-12

A counter-flow recuperator formed from annular arrays of recuperator core segments. The recuperator core segments are formed from two opposing sheets of fin fold material coined to form a primary surface zone disposed between two flattened manifold zones. Each primary surface zone has undulating corrugations including a uniform, full height central portion and a transition zone disposed between the central portion and one of the manifold zones. Corrugations of the transition zone rise from zero adjacent to the manifold zone and increase along a transition length to full crest height at the central portion. The transition lengths increase in a direction away from an inner edge containing the air inlet so as to equalize air flow to the distal regions of the primary surface zone.

Firearm suppressor having enhanced thermal management for rapid heat dissipation

DOEpatents

Moss, William C.; Anderson, Andrew T.

2014-08-19

A suppressor is disclosed for use with a weapon having a barrel through which a bullet is fired. The suppressor has an inner portion having a bore extending coaxially therethrough. The inner portion is adapted to be secured to a distal end of the barrel. A plurality of axial flow segments project radially from the inner portion and form axial flow paths through which expanding propellant gasses discharged from the barrel flow through. The axial flow segments have radially extending wall portions that define sections which may be filled with thermally conductive material, which in one example is a thermally conductive foam. The conductive foam helps to dissipate heat deposited within the suppressor during firing of the weapon.

Constitutional del(19)(q12q13.1) in a three-year-old girl with severe phenotypic abnormalities affecting multiple organ systems.

PubMed

Kulharya, A S; Michaelis, R C; Norris, K S; Taylor, H A; Garcia-Heras, J

1998-06-05

We present the clinical, cytogenetic, and molecular studies on a constitutional deletion of 19q ascertained prenatally due to decreased fetal activity and IUGR. Chromosome analysis by GTG banding on amniocytes suggested a del(19)(q13.1q13.3), but the analysis of microsatellites by PCR demonstrated that the deletion involved the distal segment of q12 and the proximal segment of q13.1 (15 cM). The severely affected female infant born at 38 weeks has clinical findings that may be related to haploinsufficiency of specific genes within 19q12.1-->q13.1 that control important processes of normal development and cell function.

Film riding seals for rotary machines

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

Bidkar, Rahul Anil; Sarawate, Neelesh Nandkumar; Wolfe, Christopher Edward

A seal assembly for a rotary machine is provided. The seal assembly includes multiple sealing device segments disposed circumferentially intermediate to a stationary housing and a rotor. Each of the segments includes a shoe plate with a forward-shoe section and an aft-shoe section having one or more labyrinth teeth therebetween facing the rotor. The sealing device includes a stator interface element having a groove or slot for allowing disposal of a spline seal for preventing segment leakages. The sealing device segment also includes multiple bellow springs or flexures connected to the shoe plate and to the stator interface element. Further,more » the sealing device segments include a secondary seal integrated with the stator interface element at one end and positioned about the multiple bellow springs or flexures and the shoe plate at the other end.« less

Visual detail about the body modulates tactile localisation biases.

PubMed

Margolis, Aaron N; Longo, Matthew R

2015-02-01

The localisation of tactile stimuli requires the integration of visual and somatosensory inputs within an internal representation of the body surface and is prone to consistent bias. Joints may play a role in segmenting such internal body representations, and may therefore influence tactile localisation biases, although the nature of this influence remains unclear. Here, we investigate the relationship between conceptual knowledge of joint locations and tactile localisation biases on the hand. In one task, participants localised tactile stimuli applied to the dorsum of their hand. A distal localisation bias was observed in all participants, consistent with previous results. We also manipulated the availability of visual information during this task, to determine whether the absence of this information could account for the distal bias observed here and by Mancini et al. (Neuropsychologia 49:1194-1201, 2011). The observed distal bias increased in magnitude when visual information was restricted, without a corresponding decrease in precision. In a separate task, the same participants indicated, from memory, knuckle locations on a silhouette image of their hand. Analogous distal biases were also seen in the knuckle localisation task. The accuracy of conceptual joint knowledge was not correlated with tactile localisation bias magnitude, although a similarity in observed bias direction suggests that both tasks may rely on a common, higher-order body representation. These results also suggest that distortions of conceptual body representation may be more common in healthy individuals than previously thought.

Effect of luminal contents on postresectional longitudinal and mucosal growth in the ileum of suckling rats.

PubMed

Ford, W D; de Vries, J E; Ross, J S; Malt, R A

1985-11-01

Effects of luminal contents on adaptive growth of the ileum in the neonatal small bowel of rats were examined after resection of the proximal small bowel and after removal of the ileum from the enteric stream. Four weeks after resection of the proximal 60% of the small bowel in 10-day-old rats, the distal 40% of the small bowel elongated by 281%. This distal segment also elongated by 265% after intestinal transection (p greater than 0.05), but by only 191% when it was bypassed (bypass versus resection or transection, p less than 0.001). After resection the distal villi were 81% taller, but after transection they were only 19% taller (p less than 0.001 versus resection); after bypass they did not grow (p less than 0.001 versus resection or transection). The distal crypts were 404% deeper after resection, 331% deeper after transection (p less than 0.05), and 291% deeper after bypass (p less than 0.001 versus resection, p greater than 0.05 versus transection). The DNA content was 517% greater after resection, 364% greater after transection (p less than 0.001), and 73% greater after bypass (p less than 0.001 versus transection or resection). Maximal elongation of the small bowel occurs in the presence of luminal nutrition. Increasing luminal nutrition is associated with increasing mucosal hyperplasia.

Evaluation of reach and grasp robot-assisted therapy suggests similar functional recovery patterns on proximal and distal arm segments in sub-acute hemiplegia.

PubMed

Loureiro, Rui C V; Harwin, William S; Lamperd, Robert; Collin, Christine

2014-05-01

This paper provides some additional evidence in support of the hypothesis that robot therapies are clinically beneficial in neurorehabilitation. Although only four subjects were included in the study, the design of the intervention and the measures were done so as to minimize bias. The results are presented as single case studies, and can only be interpreted as such due to the study size. The intensity of intervention was 16 h and the therapy philosophy (based on Carr and Shepherd) was that coordinated movements are preferable to joint based therapies, and that coordinating distal movements (in this case grasps) helps not only to recover function in these areas, but has greater value since the results are immediately transferable to daily skills such as reach and grasp movements.

[Renal physiology].

PubMed

Gueutin, Victor; Deray, Gilbert; Isnard-Bagnis, Corinne

2012-03-01

The kidneys are responsible for the urinary excretion of uremic toxins and the regulation of several body systems such as intra and extracellular volume status, acid-base status, calcium and phosphate metabolism or erythropoiesis. They adapt quantitative and qualitative composition of the urine to keep these systems in balance. The flow of plasma is filtered in the range of 120 mL/min, and depends on the systemic and renal hemodynamics which is subject to self-regulation. The original urine will then be modified in successive segments of the nephron. The proximal nephron is to lead the massive reabsorption of water and essential elements such as sodium, bicarbonates, amino-acids and glucose. The distal nephron includes the distal convoluted tubule, the connector tube and the collecting duct. Its role is to adapt the quality composition of urine to the needs of the body.

Evaluation of balanced steady-state free precession (TrueFISP) and K-space segmented gradient echo sequences for 3D coronary MR angiography with navigator gating at 3 Tesla.

PubMed

Kaul, M G; Stork, A; Bansmann, P M; Nolte-Ernsting, C; Lund, G K; Weber, C; Adam, G

2004-11-01

To test the feasibility of k-space segmented gradient-echo pulse sequences for free-breathing coronary magnetic resonance angiography (cMRA) on a clinical 3T system. T2-prepared, fat-suppressed turbo field echo (TFE, turboFLASH, SFPGR) as well as balanced TFE (b-TFE, trueFISP, FIESTA, segmented SSFP) sequences with navigator gating for prospective motion correction were applied on a 3T system equipped with a six-element phased-array cardiac coil. In 15 healthy volunteers, the right coronary artery (RCA) was examined with TFE and b-TFE sequences. Due to examination time limitations, the left coronary artery (LM/LAD) was examined exclusively with the TFE sequence in ten volunteers. Image quality was graded on a five point scale (0 = not visualized to 4 = excellent). The length, diameter and sharpness of the vessels and the contrast-to-noise ratios (CNR) were measured. 98 % of all major segments (proximal/middle/distal) of the RCA could be seen with the TFE sequence and 82 % with the b-TFE sequence. The image quality for the three segments was graded higher for the TFE sequence (2.7/2.7/1.5) than for the b-TFE sequence (1.9/1.6/0.9) with P: (< or = 0.001/< or = 0.004/< or = 0.056). The kappa of the interobserver variability was 0.75 for the TFE sequence and 0.8 for the b-TFE sequence. The measured vessel lengths were longer for the TFE sequence (95 +/- 22 mm) than for the b-TFE sequence (80 +/- 40 mm; P < or = 0.115). No significant changes (P < or = 0.074, P < or = 0.145) in diameter and vessel sharpness of the RCAs were observed between the TFE (2.4 +/- 0.3 mm, 60 % +/- 5) and b-TFE sequences (2.4 +/- 0.3 mm, 62 % +/- 6). The CNR was higher for the TFE sequence (10.1 +/- 3.4) than for the b-TFE sequence (6.6 +/- 2.1; P < or = 0.014). All ten main and proximal segments of the LM/LAD, which were examined exclusively with the TFE sequence, were visible with grade 2.5 and 2.1. The middle segment was visible in seven cases with grade 1.3. In three cases, the distal segment was visible with grade 0.5. The vessel length was 78 +/- 27 mm and the CNR 11.9 +/- 2.4. The conventional TFE technique has demonstrated good feasibility for cMRA at 3T. In its operational availability at 3T, the b-TFE sequence is inferior to the TFE sequence.

Combined radiogrammetry and texture analysis for early diagnosis of osteoporosis using Indian and Swiss data.

PubMed

Areeckal, Anu Shaju; Kamath, Jagannath; Zawadynski, Sophie; Kocher, Michel; S, Sumam David

2018-05-26

Osteoporosis is a bone disorder characterized by bone loss and decreased bone strength. The most widely used technique for detection of osteoporosis is the measurement of bone mineral density (BMD) using dual energy X-ray absorptiometry (DXA). But DXA scans are expensive and not widely available in low-income economies. In this paper, we propose a low cost pre-screening tool for the detection of low bone mass, using cortical radiogrammetry of third metacarpal bone and trabecular texture analysis of distal radius from hand and wrist radiographs. An automatic segmentation algorithm to automatically locate and segment the third metacarpal bone and distal radius region of interest (ROI) is proposed. Cortical measurements such as combined cortical thickness (CCT), cortical area (CA), percent cortical area (PCA) and Barnett Nordin index (BNI) were taken from the shaft of third metacarpal bone. Texture analysis of trabecular network at the distal radius was performed using features obtained from histogram, gray level Co-occurrence matrix (GLCM) and morphological gradient method (MGM). The significant cortical and texture features were selected using independent sample t-test and used to train classifiers to classify healthy subjects and people with low bone mass. The proposed pre-screening tool was validated on two ethnic groups, Indian sample population and Swiss sample population. Data of 134 subjects from Indian sample population and 65 subjects from Swiss sample population were analysed. The proposed automatic segmentation approach shows a detection accuracy of 86% in detecting the third metacarpal bone shaft and 90% in accurately locating the distal radius ROI. Comparison of the automatic radiogrammetry to the ground truth provided by experts show a mean absolute error of 0.04 mm for cortical width of healthy group, 0.12 mm for cortical width of low bone mass group, 0.22 mm for medullary width of healthy group, and 0.26 mm for medullary width of low bone mass group. Independent sample t-test was used to select the most discriminant features, to be used as input for training the classifiers. Pearson correlation analysis of the extracted features with DXA-BMD of lumbar spine (DXA-LS) shows significantly high correlation values. Classifiers were trained with the most significant features in the Indian and Swiss sample data. Weighted KNN classifier shows the best test accuracy of 78% for Indian sample data and 100% for Swiss sample data. Hence, combined automatic radiogrammetry and texture analysis is shown to be an effective low cost pre-screening tool for early diagnosis of osteoporosis. Copyright © 2018 Elsevier Ltd. All rights reserved.

A Kinematic Analysis of the Jumping Front-Leg Axe-Kick in Taekwondo

PubMed Central

Preuschl, Emanuel; Hassmann, Michaela; Baca, Arnold

2016-01-01

The jumping front-leg axe-kick is a valid attacking and counterattacking technique in Taekwondo competition (Streif, 1993). Yet, the existing literature on this technique is sparse (Kloiber et al., 2009). Therefore, the goal of this study was to determine parameters contributing significantly to maximum linear speed of the foot at impact. Parameters are timing of segment and joint angular velocity characteristics and segment lengths of the kicking leg. Moreover, we were interested in the prevalence of proximal-to-distal-sequencing. Three-dimensional kinematics of the kicks of 22 male Taekwondo-athletes (age: 23.3 ± 5.3 years) were recorded via a motion capturing system (Vicon Motion Systems Limited, Oxford, UK). The participants performed maximum effort kicks onto a rack-held kicking pad. Only the kick with the highest impact velocity was analysed, as it was assumed to represent the individual’s best performance. Significant Pearson correlations to impact velocity were found for pelvis tilt angular displacement (r = 0.468, p < 0.05) and for hip extension angular velocity (r = -0.446, p < 0.05) and for the timing of the minima of pelvis tilt velocity (r = -0.426, p < 0.05) and knee flexion velocity (r = -0.480, p < 0.05). Backward step linear regression analysis suggests a model consisting of three predictor variables: pelvis tilt angular displacement, hip flexion velocity at target contact and timing of pelvic tilt angular velocity minimum (adjusted R2 = 0.524). Results of Chi-Squared tests show that neither for the leg-raising period (χ2 = 2.909) of the technique, nor for the leg-lowering period a pattern of proximal-to-distal sequencing is prevalent (χ2 = 0.727). From the results we conclude that the jumping front-leg axe-kick does not follow a proximal-to-distal pattern. Raising the leg early in the technique and apprehending the upper body to be leant back during the leg-lowering period seems to be beneficial for high impact velocity. Furthermore, striking by extending the hip rather than by flexing the knee could raise impact velocity. Key points Angular velocity characteristics of the pelvis segment and the kicking leg’s hip and knee joint show no proximal-to-distal sequencing, neither for the leg-raising or leg-lowering period in a jumping front-leg axe-kick. Anthropometric parameters of taekwondo athlete’s do not influence their impact velocities. In order to raise the impact velocity in the jumping front-leg axe-kick an athlete should avoid tilting back with the torso. Instead, an upright position should be maintained. In the leg-lowering period, we suggest hitting the target by using hip extension with a rather straight knee, instead of flexing the knee. PMID:26957931

Preventing Fusion Mass Shift Avoids Postoperative Distal Curve Adding-on in Adolescent Idiopathic Scoliosis.

PubMed

Shigematsu, Hideki; Cheung, Jason Pui Yin; Bruzzone, Mauro; Matsumori, Hiroaki; Mak, Kin-Cheung; Samartzis, Dino; Luk, Keith Dip Kei

2017-05-01

Surgery for adolescent idiopathic scoliosis (AIS) is only complete after achieving fusion to maintain the correction obtained intraoperatively. The instrumented or fused segments can be referred to as the "fusion mass". In patients with AIS, the ideal fusion mass strategy has been established based on fulcrum-bending radiographs for main thoracic curves. Ideally, the fusion mass should achieve parallel endplates of the upper and lower instrumented vertebra and correct any "shift" for truncal balance. Distal adding-on is an important element to consider in AIS surgery. This phenomenon represents a progressive increase in the number of vertebrae included distally in the primary curvature and it should be avoided as it is associated with unsatisfactory cosmesis and an increased risk of revision surgery. However, it remains unknown whether any fusion mass shift, or shift in the fusion mass or instrumented segments, affects global spinal balance and distal adding-on after curve correction surgery in patients with AIS. (1) To investigate the relationship among postoperative fusion mass shift, global balance, and distal adding-on phenomenon in patients with AIS; and (2) to identify a cutoff value of fusion mass shift that will lead to distal adding-on. This was a retrospective study of patients with AIS from a single institution. Between 2006 and 2011 we performed 69 selective thoracic fusions for patients with main thoracic AIS. All patients were evaluated preoperatively and at 2 years postoperatively. The Cobb angle between the cranial and caudal endplates of the fusion mass and the coronal shift between them, which was defined as "fusion mass shift", were measured. Patients with a fusion mass Cobb angle greater than 20° were excluded to specifically determine the effect of fusion mass shift on distal adding-on phenomenon. Fusion mass shift was empirically set as 20 mm for analysis. Therefore, of the 69 patients who underwent selective thoracic fusion, only 52 with a fusion mass Cobb angle of 20° or less were recruited for study. We defined patients with a fusion mass shift of 20 mm or less as the balanced group and those with a fusion mass shift greater than 20 mm as the unbalanced group. A receiver operating characteristic (ROC) curve was used to determine the cutoff point of fusion mass shift for adding-on. Of the 52 patients studied, fusion mass shift (> 20 mm) was noted in 11 (21%), and six of those patients had distal adding-on at final followup. Although global spinal balance did not differ significantly between patients with or without fusion mass shift, the occurrence of adding-on phenomenon was significantly higher in the unbalanced group (55% (six of 11 patients), odds ratio [OR], 8.6; 95% CI, 2-39; p < 0.002) than the balanced group (12% [five of 41 patients]). Based on the ROC curve analysis, a fusion mass shift more than 18 mm was observed as the cutoff point for distal adding-on phenomenon (area under the curve, 0.70; 95% CI, 0.5-0.9; likelihood ratio, 5.0; sensitivity, 0.64; specificity, 0.73; positive predictive value, 39% [seven of 18 patients]; negative predictive value, 88% [30 of 34 patients]; OR, 4.8; 95% CI, 1-20; p = 0.02). Our study illustrates the substantial utility of the fulcrum-bending radiograph in determining fusion levels that can avoid fusion mass shift; thereby, underlining its importance in designing personalized surgical strategies for patients with scoliosis. Preoperatively, determining fusion levels by fulcrum-bending radiographs to avoid residual fusion mass shift is imperative. Intraoperatively, any fusion mass shift should be corrected to avoid distal adding-on, reoperation, and elevated healthcare costs. Level II, prognostic study.

Effect of ethnicity and sex on the growth of the axial and appendicular skeleton of children living in a developing country.

PubMed

Nyati, Lukhanyo H; Norris, Shane A; Cameron, Noel; Pettifor, John M

2006-05-01

Bones in the axial and appendicular skeletons exhibit heterogeneous growth patterns between different ethnic and sex groups. However, the influence of this differential growth on the expression of bone mineral content is not yet established. The aims of the present study were to investigate: 1) whether there are ethnic and sex differences in axial and appendicular dimensions of South African children; and 2) whether regional segment length is a better predictor of bone mass than stature. Anthropometric measurements of stature, weight, sitting height, and limb lengths were taken on 368 black and white, male and female 9-year-old children. DXA (dual-energy x-ray absorptiometry) scans of the distal ulna, distal radius, and hip and lumbar spine were also obtained. Analyses of covariance were performed to assess differences in limb lengths, adjusted for differences in stature. Multiple regression analyses were used to assess significant predictors of site-specific bone mass. Stature-adjusted means of limb lengths show that black boys have longer legs and humeri but shorter trunks than white boys. In addition, black children have longer forearms than white children, and girls have longer thighs than boys. The regression analysis demonstrated that site-specific bone mass was more strongly associated with regional segment length than stature, but this had little effect on the overall pattern of ethnic and sex differences. In conclusion, there is a differential effect of ethnicity and sex on the growth of the axial and appendicular skeletons, and regional segment length is a better predictor of site-specific bone mass than stature. Copyright 2005 Wiley-Liss, Inc.

Vascularized Jejunal Mesenteric Lymph Node Transfer: A Novel Surgical Treatment for Extremity Lymphedema.

PubMed

Coriddi, Michelle; Wee, Corrine; Meyerson, Joseph; Eiferman, Daniel; Skoracki, Roman

2017-11-01

Vascularized lymph node transfer (VLNT) is a surgical treatment for lymphedema. Multiple donor sites have been described and each has significant disadvantages. We propose the jejunal mesentery as a novel donor site for VLNT. We performed a cadaveric anatomic study analyzing jejunal lymph nodes (LNs) and describe outcomes from the first patients who received jejunal mesenteric VLNT for treatment of lymphedema. In 5 cadavers, the average numbers of total LNs and peripheral LNs were identified in the proximal, middle, and distal segments of jejunum. Totals counted were 19.2/13.8/9.6, (SD 7.0/4.4/1.1), respectively; of those, 10.4/6.8/3.4 (SD 3.6/2.3/2.6), respectively, were in the periphery. There were significantly more total and peripheral lymph nodes in the proximal segment compared with the middle and distal segments (p = 0.027 and p = 0.008, respectively). The jejunal VLNT was used in 15 patients for treatment of upper (n = 8) or lower (n = 7) extremity lymphedema. Average follow-up was 9.1 (±6.4) months (range 1 to 19 months). Of 14 patients with viable flaps (93.3%), 12 had subjective improvement (87.5%). Ten patients had preoperative measurements, and of those, 7 had objective improvement in lymphedema (70%). The jejunal mesenteric VLNT is an excellent option for lymphedema treatment because there is no risk of donor site lymphedema or nerve damage, and the scar is easily concealed. Harvest from the periphery of the proximal jejunum is optimal. Improvement from lymphedema can be expected in a majority of patients. Copyright © 2017 American College of Surgeons. Published by Elsevier Inc. All rights reserved.

Examination of Axonal Injury and Regeneration in Microfluidic Neuronal Culture Using Pulsed Laser Microbeam Dissection

PubMed Central

Hellman, Amy N.; Vahidi, Behrad; Kim, Hyung Joon; Mismar, Wael; Steward, Oswald; Jeon, Noo Li; Venugopalan, Vasan

2010-01-01

We describe the integrated use of pulsed laser microbeams and microfluidic cell culture to examine the dynamics of axonal injury and regeneration in vitro. Microfabrication methods are used to place high purity dissociated central nervous system neurons in specific regions that allow the axons to interact with permissive and inhibitory substrates. Acute injury to neuron bundles is produced via the delivery of single 180 ps duration, λ=532 nm laser pulses. Laser pulse energies of 400 nJ and 800 nJ produce partial and complete transection of the axons, respectively, resulting in elliptical lesions 25 μm and 50 μm in size. The dynamics of the resulting degeneration and regrowth of proximal and distal axonal segments are examined for up to 8 h using time-lapse microscopy. We find the proximal and distal dieback distances from the site of laser microbeam irradiation to be roughly equal for both partial and complete transection of the axons. In addition, distinct growth cones emerge from the proximal neurite segments within 1–2 h post-injury, followed by a uniform front of regenerating axons that originate from the proximal segment and traverse the injury site within 8 h. We also examine the use of EGTA to chelate the extracellular calcium and potentially reduce the severity of the axonal degeneration following injury. While we find the addition of EGTA to reduce the severity of the initial dieback, it also hampers neurite repair and interfere with the formation of neuronal growth cones to traverse the injury site. This integrated use of laser microbeam dissection within a microfluidic cell culture system to produce precise zones of neuronal injury shows potential for high-throughput screening of agents to promote neuronal regeneration. PMID:20532390

Measurement of the thickness of the urethrovaginal space in women with or without vaginal orgasm.

PubMed

Gravina, Giovanni Luca; Brandetti, Fulvia; Martini, Paolo; Carosa, Eleonora; Di Stasi, Savino M; Morano, Susanna; Lenzi, Andrea; Jannini, Emmanuele A

2008-03-01

The physiology and anatomy of female sexual function are poorly understood. The differences in sexual function among women may be partly attributed to anatomical factors. The purpose of this study was to use ultrasonography to evaluate the anatomical variability of the urethrovaginal space in women with and without vaginal orgasm. Twenty healthy, neurologically intact volunteers were recruited from a population of women who were a part of a previous published study. All women underwent a complete urodynamic evaluation and those with clinical and urodynamic urinary incontinence, idiopathic detrusor overactivity, or micturition disorders, as well as postmenopausal women and those with sexual dysfunction were excluded. The reported experience of vaginal orgasm was investigated. The urethrovaginal space thickness as measured by ultrasound was chosen as the indicator of urogenital anatomical variability. Designated evaluators carried out the measurements in a blinded fashion. The urethrovaginal space and distal, middle, and proximal urethrovaginal segments were thinner in women without vaginal orgasm. A direct correlation between the presence of vaginal orgasm and the thickness of urethrovaginal space was found. Women with a thicker urethrovaginal space were more likely to experience vaginal orgasm (r = 0.884; P = 0.015). A direct and significant correlation between the thickness of each urethrovaginal segment and the presence of vaginal orgasm was found, with the best correlation observed for the distal segment (r = 0.863; P < 0.0001). Interobserver agreement between the designated evaluators was excellent (r = 0.87; P < 0.001). The measurement of the space within the anterior vaginal wall by ultrasonography is a simple tool to explore anatomical variability of the human clitoris-urethrovaginal complex, also known as the G-spot, which can be correlated to the ability to experience the vaginally activated orgasm.

Heteromeric Kv7.2/7.3 channels differentially regulate action potential initiation and conduction in neocortical myelinated axons.

PubMed

Battefeld, Arne; Tran, Baouyen T; Gavrilis, Jason; Cooper, Edward C; Kole, Maarten H P

2014-03-05

Rapid energy-efficient signaling along vertebrate axons is achieved through intricate subcellular arrangements of voltage-gated ion channels and myelination. One recently appreciated example is the tight colocalization of K(v)7 potassium channels and voltage-gated sodium (Na(v)) channels in the axonal initial segment and nodes of Ranvier. The local biophysical properties of these K(v)7 channels and the functional impact of colocalization with Na(v) channels remain poorly understood. Here, we quantitatively examined K(v)7 channels in myelinated axons of rat neocortical pyramidal neurons using high-resolution confocal imaging and patch-clamp recording. K(v)7.2 and 7.3 immunoreactivity steeply increased within the distal two-thirds of the axon initial segment and was mirrored by the conductance density estimates, which increased from ~12 (proximal) to 150 pS μm(-2) (distal). The axonal initial segment and nodal M-currents were similar in voltage dependence and kinetics, carried by K(v)7.2/7.3 heterotetramers, 4% activated at the resting membrane potential and rapidly activated with single-exponential time constants (~15 ms at 28 mV). Experiments and computational modeling showed that while somatodendritic K(v)7 channels are strongly activated by the backpropagating action potential to attenuate the afterdepolarization and repetitive firing, axonal K(v)7 channels are minimally recruited by the forward-propagating action potential. Instead, in nodal domains K(v)7.2/7.3 channels were found to increase Na(v) channel availability and action potential amplitude by stabilizing the resting membrane potential. Thus, K(v)7 clustering near axonal Na(v) channels serves specific and context-dependent roles, both restraining initiation and enhancing conduction of the action potential.

Carboxyl-terminal Domain of Transient Receptor Potential Vanilloid 1 Contains Distinct Segments Differentially Involved in Capsaicin- and Heat-induced Desensitization*

PubMed Central

Joseph, John; Wang, Sen; Lee, Jongseok; Ro, Jin Y.; Chung, Man-Kyo

2013-01-01

Multiple Ca2+-dependent processes are involved in capsaicin-induced desensitization of transient receptor potential vanilloid 1 (TRPV1), but desensitization of TRPV1 by heat occurs even in the absence of extracellular Ca2+, although the mechanisms are unknown. In this study, we tested the hypothesis that capsaicin and heat desensitize TRPV1 through distinct mechanisms involving distinct structural segments of TRPV1. In HEK293 cells that heterologously express TRPV1, we found that heat-induced desensitization was not affected by the inclusion of intracellular ATP or alanine mutation of Lys155, both of which attenuate capsaicin-induced desensitization, suggesting that heat-induced desensitization occurs through mechanisms distinct from capsaicin-induced desensitization. To determine protein domains involved in heat-induced desensitization, we generated chimeric proteins between TRPV1 and TRPV3, a heat-gated channel lacking heat-induced desensitization. We found that TRPV1 with the carboxyl-terminal domain (CTD) of TRPV3 retained heat activation but was impaired in heat-induced desensitization. Further experiments using chimeric or deletion mutants within TRPV1 CTD indicated that the distal half of CTD regulates the activation and desensitization of TRPV1 in modality-specific manners. Within the distal CTD, we identified two segments that distinctly regulated capsaicin- and heat-induced desensitization. The results suggest that the activation and desensitization of TRPV1 by capsaicin and heat can be modulated differentially and disproportionally through different regions of TRPV1 CTD. Identifying the domains involved in thermal regulation of TRPV1 may facilitate the development of novel anti-hyperalgesic approaches aimed at attenuating activation and enhancing desensitization of TRPV1 by thermal stimuli. PMID:24174527

Polyethylene glycol treated allografts not tissue matched nor immunosuppressed rapidly repair sciatic nerve gaps, maintain neuromuscular functions, and restore voluntary behaviors in female rats.

PubMed

Mikesh, Michelle; Ghergherehchi, Cameron L; Rahesh, Sina; Jagannath, Karthik; Ali, Amir; Sengelaub, Dale R; Trevino, Richard C; Jackson, David M; Tucker, Haley O; Bittner, George D

2018-07-01

Many publications report that ablations of segments of peripheral nerves produce the following unfortunate results: (1) Immediate loss of sensory signaling and motor control; (2) rapid Wallerian degeneration of severed distal axons within days; (3) muscle atrophy within weeks; (4) poor behavioral (functional) recovery after many months, if ever, by slowly-regenerating (∼1mm/d) axon outgrowths from surviving proximal nerve stumps; and (5) Nerve allografts to repair gap injuries are rejected, often even if tissue matched and immunosuppressed. In contrast, using a female rat sciatic nerve model system, we report that neurorrhaphy of allografts plus a well-specified-sequence of solutions (one containing polyethylene glycol: PEG) successfully addresses each of these problems by: (a) Reestablishing axonal continuity/signaling within minutes by nonspecific ally PEG-fusing (connecting) severed motor and sensory axons across each anastomosis; (b) preventing Wallerian degeneration by maintaining many distal segments of inappropriately-reconnected, PEG-fused axons that continuously activate nerve-muscle junctions; (c) maintaining innervation of muscle fibers that undergo much less atrophy than otherwise-denervated muscle fibers; (d) inducing remarkable behavioral recovery to near-unoperated levels within days to weeks, almost certainly by CNS and PNS plasticities well-beyond what most neuroscientists currently imagine; and (e) preventing rejection of PEG-fused donor nerve allografts with no tissue matching or immunosuppression. Similar behavioral results are produced by PEG-fused autografts. All results for Negative Control allografts agree with current neuroscience data 1-5 given above. Hence, PEG-fusion of allografts for repair of ablated peripheral nerve segments expand on previous observations in single-cut injuries, provoke reconsideration of some current neuroscience dogma, and further extend the potential of PEG-fusion in clinical practice. © 2018 Wiley Periodicals, Inc.

Comparison of 3% sorbitol vs psyllium fibre as oral contrast agents in MR enterography.

PubMed

Saini, Sidharth; Colak, Errol; Anthwal, Shalini; Vlachou, Paraskevi A; Raikhlin, Antony; Kirpalani, Anish

2014-10-01

To compare the degree of small bowel distension achieved by 3% sorbitol, a high osmolarity solution, and a psyllium-based bulk fibre as oral contrast agents (OCAs) in MR enterography (MRE). This retrospective study was approved by our institutional review board. A total of 45 consecutive normal MRE examinations (sorbitol, n = 20; psyllium, n = 25) were reviewed. The patients received either 1.5 l of 3% sorbitol or 2 l of 1.6 g kg(-1) psyllium prior to imaging. Quantitative small bowel distension measurements were taken in five segments: proximal jejunum, distal jejunum, proximal ileum, distal ileum and terminal ileum by two independent radiologists. Distension in these five segments was also qualitatively graded from 0 (very poor) to 4 (excellent) by two additional independent radiologists. Statistical analysis comparing the groups and assessing agreement included intraclass coefficients, Student's t-test and Mann-Whitney U-test. Small bowel distension was not significantly different in any of the five small bowel segments between the use of sorbitol and psyllium as OCAs in both the qualitative (p = 0.338-0.908) and quantitative assessments (p = 0.083-0.856). The mean bowel distension achieved was 20.1 ± 2.2 mm for sorbitol and 19.8 ± 2.5 mm for psyllium (p = 0.722). Visualization of the ileum was good or excellent in 65% of the examinations in both groups. Sorbitol and psyllium are not significantly different at distending the small bowel and both may be used as OCAs for MRE studies. This is the first study to directly compare the degree of distension in MRE between these two common, readily available and inexpensive OCAs.

Heteromeric Kv7.2/7.3 Channels Differentially Regulate Action Potential Initiation and Conduction in Neocortical Myelinated Axons

PubMed Central

Battefeld, Arne; Tran, Baouyen T.; Gavrilis, Jason; Cooper, Edward C.

2014-01-01

Rapid energy-efficient signaling along vertebrate axons is achieved through intricate subcellular arrangements of voltage-gated ion channels and myelination. One recently appreciated example is the tight colocalization of Kv7 potassium channels and voltage-gated sodium (Nav) channels in the axonal initial segment and nodes of Ranvier. The local biophysical properties of these Kv7 channels and the functional impact of colocalization with Nav channels remain poorly understood. Here, we quantitatively examined Kv7 channels in myelinated axons of rat neocortical pyramidal neurons using high-resolution confocal imaging and patch-clamp recording. Kv7.2 and 7.3 immunoreactivity steeply increased within the distal two-thirds of the axon initial segment and was mirrored by the conductance density estimates, which increased from ∼12 (proximal) to 150 pS μm−2 (distal). The axonal initial segment and nodal M-currents were similar in voltage dependence and kinetics, carried by Kv7.2/7.3 heterotetramers, 4% activated at the resting membrane potential and rapidly activated with single-exponential time constants (∼15 ms at 28 mV). Experiments and computational modeling showed that while somatodendritic Kv7 channels are strongly activated by the backpropagating action potential to attenuate the afterdepolarization and repetitive firing, axonal Kv7 channels are minimally recruited by the forward-propagating action potential. Instead, in nodal domains Kv7.2/7.3 channels were found to increase Nav channel availability and action potential amplitude by stabilizing the resting membrane potential. Thus, Kv7 clustering near axonal Nav channels serves specific and context-dependent roles, both restraining initiation and enhancing conduction of the action potential. PMID:24599470

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

Sakamoto, T.; Monafo, W.W.

We used the tissue distribution of ({sup 14}C)butanol to quantitate regional blood flow in the spinal cord (RSCBF) of pentobarbital-anesthetized, normothermic rats in which segmental local cooling pentobarbital-anesthetized, normothermic rats in which segmental local cooling of the spinal cord (to 25-28{degrees}C) at vertebral levels C4-C6 (n = 6) or T13-L1 (n = 6) was induced. Thirty minutes later, blood flow measurements were made at seven levels of the spinal cord and in the sciatic nerve trunks and biceps femoris muscles. Sham-cooled rats served as controls (n = 12). In control rats, RSCBF varied between 41.5 +/- 2.4 and 65.1 +/-more » 3.2 ml.min-1.100 g-1. Local cooling of the C4-C6 cord segment reduced RSCBF by 32%, from 65.1 +/- 3.2 to 44.4 +/- 3.5 ml.min-1.100 g-1 (P less than 0.01). Tissue vascular resistance (R) in the cooled C4-C6 segment was elevated versus control. There were no other changes in RSCBF at the other cord levels or in the cauda equina. Similarly, local cooling of the T13-L1 segment resulted in a 40% fall in RSCBF in that segment, from 57.1 +/- 2.4 to 34.1 +/- 4.3 ml.min-1.100 g-1 (P less than 0.001). R in the cooled T13-L1 segment was elevated versus control. RSCBF was reduced by 30% in the adjacent proximal T12 segment (P less than 0.001) and by 21% in the adjacent distal L2-L3 segment (P less than 0.05). R was increased in both of these adjacent segments. RSCBF was not altered elsewhere in the cord.« less

Clinical feasibility and efficacy of using virtual surgical planning in bimaxillary orthognathic surgery without intermediate splint.

PubMed

Li, Yunfeng; Jiang, Yangmei; Zhang, Nan; Xu, Rui; Hu, Jing; Zhu, Songsong

2015-03-01

Computer-aided jaw surgery has been extensively studied recently. The purpose of this study was to determine the clinical feasibility of performing bimaxillary orthognathic surgery without intermediate splint using virtual surgical planning and rapid prototyping technology. Twelve consecutive patients who underwent bimaxillary orthognathic surgery were included. The presented treatment plan here mainly consists of 6 procedures: (1) data acquisition from computed tomography (CT) of the skull and laser scanning of the dentition; (2) reconstruction and fusion of a virtual skull model with accurate dentition; (3) virtual surgery simulation including osteotomy and movement and repositioning of bony segments; (4) final surgical splint fabrication (no intermediate splint) using computer-aided design and rapid prototyping technology; (5) transfer of the virtual surgical plan to the operating room; and (6) comparison of the actual surgical outcome to the virtual surgical plan. All procedures of the treatment were successfully performed on all 12 patients. In quantification of differences between simulated and actual postoperative outcome, we found that the mean linear difference was less than 1.8 mm, and the mean angular difference was less than 2.5 degrees in all evaluated patients. Results from this study suggested that it was feasible to perform bimaxillary orthognathic surgery without intermediate splint. Virtual surgical planning and the guiding splints facilitated the diagnosis, treatment planning, accurate osteotomy, and bony segments repositioning in orthognathic surgery.

Atomic structures of corkscrew-forming segments of SOD1 reveal varied oligomer conformations.

PubMed

Sangwan, Smriti; Sawaya, Michael R; Murray, Kevin A; Hughes, Michael P; Eisenberg, David S

2018-02-17

The aggregation cascade of disease-related amyloidogenic proteins, terminating in insoluble amyloid fibrils, involves intermediate oligomeric states. The structural and biochemical details of these oligomers have been largely unknown. Here we report crystal structures of variants of the cytotoxic oligomer-forming segment residues 28-38 of the ALS-linked protein, SOD1. The crystal structures reveal three different architectures: corkscrew oligomeric structure, nontwisting curved sheet structure and a steric zipper proto-filament structure. Our work highlights the polymorphism of the segment 28-38 of SOD1 and identifies the molecular features of amyloidogenic entities. © 2018 The Protein Society.

The role of robotics in computer controlled polishing of large and small optics

NASA Astrophysics Data System (ADS)

Walker, David; Dunn, Christina; Yu, Guoyu; Bibby, Matt; Zheng, Xiao; Wu, Hsing Yu; Li, Hongyu; Lu, Chunlian

2015-08-01

Following formal acceptance by ESO of three 1.4m hexagonal off-axis prototype mirror segments, one circular segment, and certification of our optical test facility, we turn our attention to the challenge of segment mass-production. In this paper, we focus on the role of industrial robots, highlighting complementarity with Zeeko CNC polishing machines, and presenting results using robots to provide intermediate processing between CNC grinding and polishing. We also describe the marriage of robots and Zeeko machines to automate currently manual operations; steps towards our ultimate vision of fully autonomous manufacturing cells, with impact throughout the optical manufacturing community and beyond.

Transiently Produced Hypochlorite Is Responsible for the Irreversible Inhibition of Chlorite Dismutase

PubMed Central

2014-01-01

Chlorite dismutases (Clds) are heme b-containing prokaryotic oxidoreductases that catalyze the reduction of chlorite to chloride with the concomitant release of molecular oxygen. Over time, they are irreversibly inactivated. To elucidate the mechanism of inactivation and investigate the role of the postulated intermediate hypochlorite, the pentameric chlorite dismutase of “Candidatus Nitrospira defluvii” (NdCld) and two variants (having the conserved distal arginine 173 exchanged with alanine and lysine) were recombinantly produced in Escherichia coli. Exchange of the distal arginine boosts the extent of irreversible inactivation. In the presence of the hypochlorite traps methionine, monochlorodimedone, and 2-[6-(4-aminophenoxy)-3-oxo-3H-xanthen-9-yl]benzoic acid, the extent of chlorite degradation and release of molecular oxygen is significantly increased, whereas heme bleaching and oxidative modifications of the protein are suppressed. Among other modifications, hypochlorite-mediated formation of chlorinated tyrosines is demonstrated by mass spectrometry. The data obtained were analyzed with respect to the proposed reaction mechanism for chlorite degradation and its dependence on pH. We discuss the role of distal Arg173 by keeping hypochlorite in the reaction sphere for O–O bond formation. PMID:24754261

Widespread spinal cord involvement in progressive supranuclear palsy.

PubMed

Iwasaki, Yasushi; Yoshida, Mari; Hashizume, Yoshio; Hattori, Manabu; Aiba, Ikuko; Sobue, Gen

2007-08-01

We describe the histopathologic features of spinal cord lesions in 10 cases of progressive supranuclear palsy (PSP) and review the literature. Histologic examination revealed atrophy with myelin pallor in the anterior funiculus and anterolateral funiculus in the cervical and thoracic segments in eight of the 10 cases, whereas the posterior funiculus was well preserved. The degrees of atrophy of the anterior funiculus and the anterolateral funiculus correlated with that of the tegmentum of the medulla oblongata. Myelin pallor of the lateral corticospinal tract was observed in two of the 10 cases. Microscopic observation of the spinal white matter, particularly the cervical segment, revealed a few to several neuropil threads, particularly in the white matter surrounding the anterior horn after Gallyas-Braak (GB) staining or AT-8 tau immunostaining. However, the posterior funiculus was completely preserved from the presence of argyrophilic or tau-positive structures. In the spinal gray matter, widespread distribution of neurons with cytoplasmic inclusions and neuropil threads was observed, particularly in the medial division of the anterior horn and intermediate gray matter, especially in the cervical segment. Globose-type neurofibrillary tangles and pretangles were found. The distribution of GB- or AT-8 tau-positive small neurons and neuropil threads resembled that of the spinal interneurons. In conclusion, the spinal cord, especially the cervical segment, is constantly involved in the pathologic process of PSP. We speculate that spinal interneurons and their neuronal processes, particularly in the medial division of the anterior horn and intermediate gray matter of the cervical segment, are most severely damaged in the PSP spinal cord.

Toward an endovascular internal carotid artery classification system.

PubMed

Shapiro, M; Becske, T; Riina, H A; Raz, E; Zumofen, D; Jafar, J J; Huang, P P; Nelson, P K

2014-02-01

Does the world need another ICA classification scheme? We believe so. The purpose of proposed angiography-driven classification is to optimize description of the carotid artery from the endovascular perspective. A review of existing, predominantly surgically-driven classifications is performed, and a new scheme, based on the study of NYU aneurysm angiographic and cross-sectional databases is proposed. Seven segments - cervical, petrous, cavernous, paraophthlamic, posterior communicating, choroidal, and terminus - are named. This nomenclature recognizes intrinsic uncertainty in precise angiographic and cross-sectional localization of aneurysms adjacent to the dural rings, regarding all lesions distal to the cavernous segment as potentially intradural. Rather than subdividing various transitional, ophthalmic, and hypophyseal aneurysm subtypes, as necessitated by their varied surgical approaches and risks, the proposed classification emphasizes their common endovascular treatment features, while recognizing that many complex, trans-segmental, and fusiform aneurysms not readily classifiable into presently available, saccular aneurysm-driven schemes, are being increasingly addressed by endovascular means. We believe this classification may find utility in standardizing nomenclature for outcome tracking, treatment trials and physician communication.

Accuracy and Reliability of Marker-Based Approaches to Scale the Pelvis, Thigh, and Shank Segments in Musculoskeletal Models.

PubMed

Kainz, Hans; Hoang, Hoa X; Stockton, Chris; Boyd, Roslyn R; Lloyd, David G; Carty, Christopher P

2017-10-01

Gait analysis together with musculoskeletal modeling is widely used for research. In the absence of medical images, surface marker locations are used to scale a generic model to the individual's anthropometry. Studies evaluating the accuracy and reliability of different scaling approaches in a pediatric and/or clinical population have not yet been conducted and, therefore, formed the aim of this study. Magnetic resonance images (MRI) and motion capture data were collected from 12 participants with cerebral palsy and 6 typically developed participants. Accuracy was assessed by comparing the scaled model's segment measures to the corresponding MRI measures, whereas reliability was assessed by comparing the model's segments scaled with the experimental marker locations from the first and second motion capture session. The inclusion of joint centers into the scaling process significantly increased the accuracy of thigh and shank segment length estimates compared to scaling with markers alone. Pelvis scaling approaches which included the pelvis depth measure led to the highest errors compared to the MRI measures. Reliability was similar between scaling approaches with mean ICC of 0.97. The pelvis should be scaled using pelvic width and height and the thigh and shank segment should be scaled using the proximal and distal joint centers.

Film riding seal assembly for turbomachinery

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

Bidkar, Rahul Anil; Giametta, Andrew Paul; Gibson, Nathan Evan McCurdy

2016-06-07

An aerodynamic seal assembly for a rotary machine includes multiple sealing segments disposed circumferentially intermediate to a stationary housing and a rotor. Each of the segments includes a shoe plate with a forward load-bearing section and an aft load-bearing section configured to generate an aerodynamic force between the shoe plate and the rotor. The shoe plate includes at least one labyrinth teeth facing the rotor and positioned between the forward load-bearing section and the aft load-bearing section. The sealing segment also includes at least one spring connected to a pedestal located about midway of an axial length of the shoemore » plate and to a stator interface element. Further, the sealing segment includes a rigid segmented secondary seal attached to the stator interface element at one first end and in contact with the pedestal of the shoe plate at one second end.« less

Ruptured Distal Posterior Inferior Cerebellar Artery (PICA) Aneurysms Associated with Cerebellar Arterial Venous Malformations (AVMs): A Case Series and Review of the Literature Demonstrating the Need for Angiographic Evaluation and Feasibility of Endovascular Treatment.

PubMed

Case, David; Kumpe, David; Cava, Luis; Neumann, Robert; White, Andrew; Roark, Christopher; Seinfeld, Joshua

2017-01-01

The characteristics, diagnosis, and preferred management strategies for distal posterior inferior cerebellar artery (PICA) aneurysms associated with cerebellar arteriovenous malformation (AVMs) are poorly understood. We present a case series with attention to aneurysm angioarchitecture, diagnostic imaging, treatment approaches, and a thorough review of the literature. With this information, we demonstrate a specific anatomical pattern for these aneurysms, an underreported need for conventional digital subtraction angiography (DSA) during evaluation, along with the utility of endovascular treatment with liquid embolic agents. Neurosurgical patients from 2005 to 2016 were reviewed to identify PICA aneurysms along with distal PICA aneurysms. Details of their presentation, imaging studies, associated AVMs and treatment were recorded. A thorough literature search of previous case series and case reports of distal PICA aneurysms with and without associated small cerebellar AVMs was performed with PubMed and Google Scholar. Thirty-four patients with PICA aneurysms were identified at our institution, 12 of which were in a distal segment. All 12 of these patients underwent DSA as a part of their evaluation. Of the 12 patients with distal PICA aneurysms, 9 presented with subarachnoid hemorrhage and intraventricular hemorrhage. Five of these patients had a small occult cerebellar AVM. All nine patients presenting with a ruptured distal PICA aneurysm had a Fischer grade 4 subarachnoid hemorrhage. Of the five patients with a small occult cerebellar AVM, the AVM nidus was missed on computed tomography angiogram (CTA) interpretation but easily visualized with DSA. CTA followed by DSA with concurrent endovascular treatment was performed in 9 of the 12 patients with distal PICA aneurysms. Two of the 12 patients were treated with microsurgical clip ligation, and one mycotic aneurysm was identified and treated with antibiotics. Parent vessel sacrifice was used distal to the aneurysm in all 5 associated AVM cases with liquid embolic agents as well as AVM embolization in 3 of the 5 cases. Fifty-one well-described case reports of distal PICA aneurysms associated with small cerebellar AVMs have been reported in the literature. A total of 12 well-described case series of distal PICA aneurysms that comment on associated AVMs describe an associated small cerebellar AVM incidence of 4%-50%. In our case series, the incidence of an associated small cerebellar AVM with a distal PICA aneurysm was 42%. In cases of distal PICA aneurysms, there is a frequent association of a small cerebellar AVM. In our series, CTA was an inadequate diagnostic study to identify the associated AVM, and DSA was necessary to definitely visualize the AVM nidus. Endovascular treatment of the aneurysm and AVM with the use of liquid embolic agents was a feasible and useful management strategy. Copyright © 2016 Elsevier Inc. All rights reserved.

Foot and Ankle Kinematics During Descent From Varying Step Heights.

PubMed

Gerstle, Emily E; O'Connor, Kristian; Keenan, Kevin G; Cobb, Stephen C

2017-12-01

In the general population, one-third of incidences during step negotiation occur during the transition to level walking. Furthermore, falls during curb negotiation are a common cause of injury in older adults. Distal foot kinematics may be an important factor in determining injury risk associated with transition step negotiation. The purpose of this study was to identify foot and ankle kinematics of uninjured individuals during descent from varying step heights. A 7-segment foot model was used to quantify kinematics as participants walked on a level walkway, stepped down a single step (heights: 5 cm, 15 cm, 25 cm), and continued walking. As step height increased, landing strategy transitioned from the rearfoot to the forefoot, and the rearfoot, lateral and medial midfoot, and medial forefoot became more plantar flexed. During weight acceptance, sagittal plane range of motion of the rearfoot, lateral midfoot, and medial and lateral forefoot increased as step height increased. The changes in landing strategy and distal foot function suggest a less stable ankle position at initial contact and increased demand on the distal foot at initial contact and through the weight acceptance phase of transition step negotiation as step height increases.

Novel Model of Somatosensory Nerve Transfer in the Rat.

PubMed

Paskal, Adriana M; Paskal, Wiktor; Pelka, Kacper; Podobinska, Martyna; Andrychowski, Jaroslaw; Wlodarski, Pawel K

2018-05-09

Nerve transfer (neurotization) is a reconstructive procedure in which the distal denervated nerve is joined with a proximal healthy nerve of a less significant function. Neurotization models described to date are limited to avulsed roots or pure motor nerve transfers, neglecting the clinically significant mixed nerve transfer. Our aim was to determine whether femoral-to-sciatic nerve transfer could be a feasible model of mixed nerve transfer. Three Sprague Dawley rats were subjected to unilateral femoral-to-sciatic nerve transfer. After 50 days, functional recovery was evaluated with a prick test. At the same time, axonal tracers were injected into each sciatic nerve distally to the lesion site, to determine nerve fibers' regeneration. In the prick test, the rats retracted their hind limbs after stimulation, although the reaction was moderately weaker on the operated side. Seven days after injection of axonal tracers, dyes were visualized by confocal microscopy in the spinal cord. Innervation of the recipient nerve originated from higher segments of the spinal cord than that on the untreated side. The results imply that the femoral nerve axons, ingrown into the damaged sciatic nerve, reinnervate distal targets with a functional outcome.

Distal 10q monosomy: new evidence for a neurobehavioral condition?

PubMed

Plaisancié, Julie; Bouneau, Laurence; Cances, Claude; Garnier, Christelle; Benesteau, Jacques; Leonard, Samantha; Bourrouillou, Georges; Calvas, Patrick; Vigouroux, Adeline; Julia, Sophie; Bieth, Eric

2014-01-01

Pure distal monosomy of the long arm of chromosome 10 is a rare cytogenetic abnormality. The location and size of the deletions described in this region are variable. Nevertheless, the patients share characteristic facial appearance, variable cognitive impairment and neurobehavioral manifestations. A Minimal Critical Region corresponding to a 600 kb Smallest Region of deletion Overlap (SRO) has been proposed. In this report, we describe four patients with a distal 10q26 deletion, who displayed attention-deficit/hyperactivity disorders (ADHD). One of them had a marked behavioral profile and relatively preserved cognitive functions. Interestingly, the SRO was not included in the deleted segment of this patient suggesting that this deletion could contain candidate genes involved in the control of neurobehavioral functions. One of these candidates was the CALY gene, known for its association with ADHD patients and whose expression level was shown to be correlated with neurobehavioral disturbances in varying animal models. This report emphasizes the importance of the behavioral problems as a cardinal feature of the 10q microdeletion syndrome. Haploinsufficiency of CALY could play a crucial role in the development of the behavioral troubles within these patients. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

Aerodynamic seals for rotary machine

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

Bidkar, Rahul Anil; Cirri, Massimiliano; Thatte, Azam Mihir

2016-02-09

An aerodynamic seal assembly for a rotary machine includes multiple sealing device segments disposed circumferentially intermediate to a stationary housing and a rotor. Each of the segments includes a shoe plate with a forward-shoe section and an aft-shoe section having multiple labyrinth teeth therebetween facing the rotor. The sealing device segment also includes multiple flexures connected to the shoe plate and to a top interface element, wherein the multiple flexures are configured to allow the high pressure fluid to occupy a forward cavity and the low pressure fluid to occupy an aft cavity. Further, the sealing device segments include amore » secondary seal attached to the top interface element at one first end and positioned about the flexures and the shoe plate at one second end.« less

Image processing based detection of lung cancer on CT scan images

NASA Astrophysics Data System (ADS)

Abdillah, Bariqi; Bustamam, Alhadi; Sarwinda, Devvi

2017-10-01

In this paper, we implement and analyze the image processing method for detection of lung cancer. Image processing techniques are widely used in several medical problems for picture enhancement in the detection phase to support the early medical treatment. In this research we proposed a detection method of lung cancer based on image segmentation. Image segmentation is one of intermediate level in image processing. Marker control watershed and region growing approach are used to segment of CT scan image. Detection phases are followed by image enhancement using Gabor filter, image segmentation, and features extraction. From the experimental results, we found the effectiveness of our approach. The results show that the best approach for main features detection is watershed with masking method which has high accuracy and robust.

Distributions of nerve and muscle fibre types in locust jumping muscle.

PubMed

Hoyle, G

1978-04-01

Muscle fibres of the locust extensor tibiae (jumping muscle) were examined by interference microscopy and by electron microscopy. The electrical responses of single fibres and the mechanical responses of bundles or selected regions to the nerve fibres were examined. Four axons innervate the muscle: fast (FETi), slow (SETi), common inhibitor (CI) and dorsal unpaired median (DUMETi). Their distributions were examined by combined electrophysiological tracing and EM sectioning. The mean diameter of muscle fibres in different regions varies from 40 to 140 micrometer and is related to the local leg thickness rather than muscle fibre type. The fine structure of a fibre is related to its innervation. Fibres innervated by FETi but not SETi are of fast type ultrastructurally. Fibres innervated by SETi but not by FETi are of slow type ultrastructurally. Fibres innervated by both axons are generally intermediate between the extremes though more nearly of fast type than slow. Distal slow muscle fibres have much slower relaxation rates than do proximal ones. The most proximal bundles are of mixed muscle fibre type. There is an abrupt transition from a mixed population to homogeneous fast type, in the muscle units immediately distal to the most proximal bundles. This transition is associated with the presence of DUMETi terminals on some of the fibres distal to the transition point. There are no SETi endings on these same fibres. Fibres innervated by both SETi and FETi are scattered throughout the leg, but are commonest in the dorsal bundles. The percentage of these increases progressively passing distally. The most distal muscle fibres are innervated by SETi but not by FETi. It is concluded that different regions of the muscle will play different roles functionally since they are differentially sensitive to the pattern of SETi discharge.

Image analysis software versus direct anthropometry for breast measurements.

PubMed

Quieregatto, Paulo Rogério; Hochman, Bernardo; Furtado, Fabianne; Machado, Aline Fernanda Perez; Sabino Neto, Miguel; Ferreira, Lydia Masako

2014-10-01

To compare breast measurements performed using the software packages ImageTool(r), AutoCAD(r) and Adobe Photoshop(r) with direct anthropometric measurements. Points were marked on the breasts and arms of 40 volunteer women aged between 18 and 60 years. When connecting the points, seven linear segments and one angular measurement on each half of the body, and one medial segment common to both body halves were defined. The volunteers were photographed in a standardized manner. Photogrammetric measurements were performed by three independent observers using the three software packages and compared to direct anthropometric measurements made with calipers and a protractor. Measurements obtained with AutoCAD(r) were the most reproducible and those made with ImageTool(r) were the most similar to direct anthropometry, while measurements with Adobe Photoshop(r) showed the largest differences. Except for angular measurements, significant differences were found between measurements of line segments made using the three software packages and those obtained by direct anthropometry. AutoCAD(r) provided the highest precision and intermediate accuracy; ImageTool(r) had the highest accuracy and lowest precision; and Adobe Photoshop(r) showed intermediate precision and the worst accuracy among the three software packages.

Prognostic Value of Transthoracic Doppler Echocardiography Coronary Flow Velocity Reserve in Patients with Nonculprit Stenosis of Intermediate Severity Early after Primary Percutaneous Coronary Intervention.

PubMed

Tesic, Milorad; Djordjevic-Dikic, Ana; Giga, Vojislav; Stepanovic, Jelena; Dobric, Milan; Jovanovic, Ivana; Petrovic, Marija; Mehmedbegovic, Zlatko; Milasinovic, Dejan; Dedovic, Vladimir; Zivkovic, Milorad; Juricic, Stefan; Orlic, Dejan; Stojkovic, Sinisa; Vukcevic, Vladan; Stankovic, Goran; Nedeljkovic, Milan; Ostojic, Miodrag; Beleslin, Branko

2018-04-03

Treatment of nonculprit coronary stenosis during primary percutaneous coronary intervention in patients with ST-segment elevation myocardial infarction may be beneficial, but the mode and timing of the intervention are still controversial. The aim of this study was to examine the significance and prognostic value of preserved coronary flow velocity reserve (CFVR) in patients with nonculprit intermediate stenosis early after primary percutaneous coronary intervention. Two hundred thirty patients with remaining intermediate (50%-70%) stenosis of non-infarct-related arteries, in whom CFVR was performed within 7 days after primary percutaneous coronary intervention, were prospectively enrolled. Twenty patients with reduced CFVR and positive results on stress echocardiography or impaired fractional flow reserve underwent revascularization and were not included in further analysis. The final study population of 210 patients (mean age, 58 ± 10 years; 162 men) was divided into two groups on the basis of CFVR: group 1, CFVR > 2 (n = 174), and group 2, CFVR ≤ 2 (n = 36). Cardiac death, nonfatal myocardial infarction, and revascularization of the evaluated vessel were considered adverse events. Mean follow-up duration was 47 ± 16 months. Mean CFVR for the whole group was 2.36 ± 0.40. There were six adverse events (3.4%) related to the nonculprit coronary artery in group 1, including one cardiac death, one ST-segment elevation myocardial infarction, and four revascularizations. In group 2, there were 30 adverse events (83.3%, P < .001 vs group 1), including two cardiac deaths, two ST-segment elevation myocardial infarctions, and 26 revascularizations. In patients with CFVR > 2 of the intermediate nonculprit coronary lesion, deferral of revascularization is safe and associated with excellent long-term clinical outcomes. Copyright © 2018 American Society of Echocardiography. Published by Elsevier Inc. All rights reserved.

Closed loop problems in biomechanics. Part II--an optimization approach.

PubMed

Vaughan, C L; Hay, J G; Andrews, J G

1982-01-01

A closed loop problem in biomechanics may be defined as a problem in which there are one or more closed loops formed by the human body in contact with itself or with an external system. Under certain conditions the problem is indeterminate--the unknown forces and torques outnumber the equations. Force transducing devices, which would help solve this problem, have serious drawbacks, and existing methods are inaccurate and non-general. The purposes of the present paper are (1) to develop a general procedure for solving closed loop problems; (2) to illustrate the application of the procedure; and (3) to examine the validity of the procedure. A mathematical optimization approach is applied to the solution of three different closed loop problems--walking up stairs, vertical jumping and cartwheeling. The following conclusions are drawn: (1) the method described is reasonably successful for predicting horizontal and vertical reaction forces at the distal segments although problems exist for predicting the points of application of these forces; (2) the results provide some support for the notion that the human neuromuscular mechanism attempts to minimize the joint torques and thus, to a certain degree, the amount of muscular effort; (3) in the validation procedure it is desirable to have a force device for each of the distal segments in contact with a fixed external system; and (4) the method is sufficiently general to be applied to all classes of closed loop problems.

An evaluation of two types of nickel-titanium wires in terms of micromorphology and nickel ions' release following oral environment exposure.

PubMed

Ghazal, Abdul Razzak A; Hajeer, Mohammad Y; Al-Sabbagh, Rabab; Alghoraibi, Ibrahim; Aldiry, Ahmad

2015-01-01

This study aimed to compare superelastic and heat-activated nickel-titanium orthodontic wires' surface morphology and potential release of nickel ions following exposure to oral environment conditions. Twenty-four 20-mm-length distal cuts of superelastic (NiTi Force I®) and 24 20-mm-length distal cuts of heat-activated (Therma-Ti Lite®) nickel-titanium wires (American Orthodontics, Sheboygan, WI, USA) were divided into two equal groups: 12 wire segments left unused and 12 segments passively exposed to oral environment for 1 month. Scanning electron microscopy and atomic force microscopy were used to analyze surface morphology of the wires which were then immersed in artificial saliva for 1 month to determine potential nickel ions' release by means of atomic absorption spectrophotometer. Heat-activated nickel-titanium (NiTi) wires were rougher than superelastic wires, and both types of wires released almost the same amount of Ni ions. After clinical exposure, more surface roughness was recorded for superelastic NiTi wires and heat-activated NiTi wires. However, retrieved superelastic NiTi wires released less Ni ions in artificial saliva after clinical exposure, and the same result was recorded regarding heat-activated wires. Both types of NiTi wires were obviously affected by oral environment conditions; their surface roughness significantly increased while the amount of the released Ni ions significantly declined.

Thermal comfort zone of the hands, feet and head in males and females.

PubMed

Ciuha, Urša; Mekjavic, Igor B

2017-10-01

The present study compared the thermal comfort zones (TCZ) of the hands, feet and head in eight male and eight female participants, assessed with water-perfused segments (WPS). On separate occasions, and separated by a minimum of one day, participants were requested to regulate the temperature of three distal skin regions (hands, feet and head) within their TCZ. On each occasion they donned a specific water-perfused segment (WPS), either gloves, socks or hood for assessing the TCZ of the hands, feet and head, respectively. In the absence of regulation, the temperature of the water perfusing the WPS changed in a saw-tooth manner from 10 to 50°C; by depressing a switch and reversing the direction of the temperature at the limits of the TCZ, each participant defined the TCZ for each skin region investigated. The range of regulated temperatures (upper and lower limits of the TCZ) did not differ between studied skin regions or between genders. Participants however maintained higher head (35.7±0.4°C; p˂0.001) skin temperature (Tsk) compared to hands (34.5±0.8°C) and feet (33.8±1.1°C). When exposed to normothermic conditions, distal skin regions do not differ in ranges of temperatures, perceived as thermally comfortable. Copyright © 2017. Published by Elsevier Inc.

Single-Center Experience Using the 3MAX Reperfusion Catheter for the Treatment of Acute Ischemic Stroke with Distal Arterial Occlusions.

PubMed

Premat, Kévin; Bartolini, Bruno; Baronnet-Chauvet, Flore; Shotar, Eimad; Degos, Vincent; Muresan, Paul; Di Maria, Federico; Gabrieli, Joseph; Rosso, Charlotte; Pistocchi, Silvia; Chiras, Jacques; Sourour, Nader; Alamowitch, Sonia; Samson, Yves; Clarençon, Frédéric

2017-05-15

Most recent guidelines recommend the use of stent retriever devices in endovascular treatment of acute ischemic stroke with large vessel occlusion (LVO). Recently published data reported convincing results with thromboaspiration devices such as the Penumbra System (Penumbra, Alameda, CA, USA) combined with supple reperfusion catheters by using the ADAPT (A Direct Aspiration First-Pass Thrombectomy) technique. The aim of this study was to report our initial experience with the 3MAX (3.8 F) reperfusion catheter for the recanalization of distal intracranial arteries. From August 2015 to December 2016, 32 consecutive patients (16 females, 50%; mean age = 67.4 ± 18.7 years, range: 22-91) for 38 distal occlusions underwent mechanical thrombectomy (MT) by thromboaspiration using the 3MAX. Median NIHSS score at admission was 14 (IQR: 9-19). Distal occlusions were distributed as follows: M2 (n: 23), M3 (n: 6), P1 (n: 3), P2 (n: 2), P3 (n: 2), A3 segment (n: 1) and superior cerebellar artery (n: 1). In 1/38 (2.6%) target artery, the 3MAX could not be navigated. Of the 37 (59.5%) remaining arteries, 22 were successfully reperfused (TICI 2b/3) after ADAPT with the 3MAX alone. Additional stent retriever thrombectomy allowed a 76.3% final reperfusion rate. Good functional outcome (mRS ≤2) was obtained in 45.5% of patients at 3 months. Three (9.4%) 3MAX-related complications occurred: 2 emboli to new territory (ENT) and one vascular perforation. The 3MAX is well-navigable in distal arteries making it useful as a frontline technique. However, the reperfusion rate with the 3MAX catheter alone seems lower than the ones reported with stent retrievers for such distal occlusions.

The Acyl Desaturase CER17 Is Involved in Producing Wax Unsaturated Primary Alcohols and Cutin Monomers1[OPEN

PubMed Central

Yang, Xianpeng; Zhao, Huayan; Kosma, Dylan K.; Dyer, John M.; Li, Rongjun; Liu, Xiulin; Wang, Zhouya; Jenks, Matthew A.

2017-01-01

We report n-6 monounsaturated primary alcohols (C26:1, C28:1, and C30:1 homologs) in the cuticular waxes of Arabidopsis (Arabidopsis thaliana) inflorescence stem, a class of wax not previously reported in Arabidopsis. The Arabidopsis cer17 mutant was completely deficient in these monounsaturated alcohols, and CER17 was found to encode a predicted ACYL-COENZYME A DESATURASE LIKE4 (ADS4). Studies of the Arabidopsis cer4 mutant and yeast variously expressing CER4 (a predicted fatty acyl-CoA reductase) with CER17/ADS4, demonstrated CER4’s principal role in synthesis of these monounsaturated alcohols. Besides unsaturated alcohol deficiency, cer17 mutants exhibited a thickened and irregular cuticle ultrastructure and increased amounts of cutin monomers. Although unsaturated alcohols were absent throughout the cer17 stem, the mutation’s effects on cutin monomers and cuticle ultrastructure were much more severe in distal than basal stems, consistent with observations that the CER17/ADS4 transcript was much more abundant in distal than basal stems. Furthermore, distal but not basal stems of a double mutant deficient for both CER17/ADS4 and LONG-CHAIN ACYL-COA SYNTHETASE1 produced even more cutin monomers and a thicker and more disorganized cuticle ultrastructure and higher cuticle permeability than observed for wild type or either mutant parent, indicating a dramatic genetic interaction on conversion of very long chain acyl-CoA precursors. These results provide evidence that CER17/ADS4 performs n-6 desaturation of very long chain acyl-CoAs in both distal and basal stems and has a major function associated with governing cutin monomer amounts primarily in the distal segments of the inflorescence stem. PMID:28069670

Relationship between cell volume and ion transport in the early distal tubule of the Amphiuma kidney.

PubMed

Guggino, W B; Oberleithner, H; Giebisch, G

1985-07-01

The roles of apical and basolateral transport mechanisms in the regulation of cell volume and the hydraulic water permeabilities (Lp) of the individual cell membranes of the Amphiuma early distal tubule (diluting segment) were evaluated using video and optical techniques as well as conventional and Cl-sensitive microelectrodes. The Lp of the apical cell membrane calculated per square centimeter of tubule is less than 3% that of the basolateral cell membrane. Calculated per square centimeter of membrane, the Lp of the apical cell membrane is less than 40% that of the basolateral cell membrane. Thus, two factors are responsible for the asymmetry in the Lp of the early distal tubule: an intrinsic difference in the Lp per square centimeter of membrane area, and a difference in the surface areas of the apical and basolateral cell membranes. Early distal tubule cells do not regulate volume after a reduction in bath osmolality. This cell swelling occurs without a change in the intracellular Cl content or the basolateral cell membrane potential. In contrast, reducing the osmolality of the basolateral solution in the presence of luminal furosemide diminishes the magnitude of the increase in cell volume to a value below that predicted from the change in osmolality. This osmotic swelling is associated with a reduction in the intracellular Cl content. Hence, early distal tubule cells can lose solute in response to osmotic swelling, but only after the apical Na/K/Cl transporter is blocked. Inhibition of basolateral Na/K ATPase with ouabain results in severe cell swelling. This swelling in response to ouabain can be inhibited by the prior application of furosemide, which suggests that the swelling is due to the continued entry of solutes, primarily through the apical cotransport pathway.

Relationship between cell volume and ion transport in the early distal tubule of the Amphiuma kidney

PubMed Central

1985-01-01

The roles of apical and basolateral transport mechanisms in the regulation of cell volume and the hydraulic water permeabilities (Lp) of the individual cell membranes of the Amphiuma early distal tubule (diluting segment) were evaluated using video and optical techniques as well as conventional and Cl-sensitive microelectrodes. The Lp of the apical cell membrane calculated per square centimeter of tubule is less than 3% that of the basolateral cell membrane. Calculated per square centimeter of membrane, the Lp of the apical cell membrane is less than 40% that of the basolateral cell membrane. Thus, two factors are responsible for the asymmetry in the Lp of the early distal tubule: an intrinsic difference in the Lp per square centimeter of membrane area, and a difference in the surface areas of the apical and basolateral cell membranes. Early distal tubule cells do not regulate volume after a reduction in bath osmolality. This cell swelling occurs without a change in the intracellular Cl content or the basolateral cell membrane potential. In contrast, reducing the osmolality of the basolateral solution in the presence of luminal furosemide diminishes the magnitude of the increase in cell volume to a value below that predicted from the change in osmolality. This osmotic swelling is associated with a reduction in the intracellular Cl content. Hence, early distal tubule cells can lose solute in response to osmotic swelling, but only after the apical Na/K/Cl transporter is blocked. Inhibition of basolateral Na/K ATPase with ouabain results in severe cell swelling. This swelling in response to ouabain can be inhibited by the prior application of furosemide, which suggests that the swelling is due to the continued entry of solutes, primarily through the apical cotransport pathway. PMID:2411847

Serial electrophysiological findings in Guillain-Barré syndrome not fulfilling AIDP or AMAN criteria.

PubMed

Hosokawa, Takafumi; Nakajima, Hideto; Unoda, Kiichi; Yamane, Kazushi; Doi, Yoshimitsu; Ishida, Shimon; Kimura, Fumiharu; Hanafusa, Toshiaki

2016-09-01

Guillain-Barré syndrome (GBS) is categorized into two major subtypes: acute inflammatory demyelinating polyneuropathy (AIDP) and acute motor axonal neuropathy (AMAN). However, a proportion of patients are electrophysiologically unclassified because of electrophysiological findings that do not fulfil AIDP or AMAN criteria, and underlying pathophysiological mechanisms and lesion distributions of unclassified patients are not well defined. The aims of this study are to elucidate disease pathophysiology and lesion distribution in unclassified patients. We retrospectively studied 48 consecutive GBS patients. Patients were classified on the basis of initial electrophysiological findings according to Ho's criteria. Clinical and serial electrophysiological examinations of unclassified patients were conducted. Twelve (25 %) GBS patients were unclassified. All unclassified patients were able to walk independently at 21 days after onset. No unclassified patients, except one patient with diabetes mellitus, had sensory nerve involvement. Eight patients underwent a follow-up study within 15 days of the initial study. Distal motor latencies (DMLs) of the left median motor nerve were found to be significantly and uniformly decreased compared with initial studies (p = 0.008). DMLs (p < 0.0001) and distal compound action potential (CMAP) durations (p = 0.002) of all nerves were significantly decreased, and distal CMAP amplitudes (p = 0.026) significantly increased compared with initial studies. In unclassified GBS patients, DML values during initial electrophysiological studies would be prolonged compared with expected values in the same patient unaffected by GBS and later improve rapidly with increased distal CMAP amplitudes without the development of excessive temporal dispersions. Lesions are also present in distal nerve segments caused by reversible conduction failure.

Better Skeletal Microstructure Confers Greater Mechanical Advantages in Chinese-American Women Versus White Women

PubMed Central

Liu, X Sherry; Walker, Marcella D; McMahon, Donald J; Udesky, Julia; Liu, George; Bilezikian, John P; Guo, X Edward

2013-01-01

Despite lower areal bone mineral density (aBMD), Chinese-American women have fewer fractures than white women. We hypothesized that better skeletal microstructure in Chinese-American women in part could account for this paradox. Individual trabecula segmentation (ITS), a novel image-analysis technique, and micro–finite-element analysis (μFEA) were applied to high-resolution peripheral quantitative computed tomography (HR-pQCT) images to determine bone microarchitecture and strength in premenopausal Chinese-American and white women. Chinese-American women had 95% and 80% higher plate bone volume fraction at the distal radius and tibia, respectively, as well as 20% and 18% higher plate number density compared with white women (p < .001). With similar rodlike characteristics, the plate-to-rod ratio was twice as high in the Chinese-American than in white trabecular bone (p < .001). Plate-rod junction density, a parameter indicating trabecular network connections, was 37% and 29% greater at the distal radius and tibia, respectively, in Chinese-American women (p < .002). Moreover, the orientation of the trabecular bone network was more axially aligned in Chinese-American women because axial bone volume fraction was 51% and 32% higher at the distal radius and tibia, respectively, than in white women (p < .001). These striking differences in trabecular bone microstructure translated into 55% to 68% (distal radius, p < .001) and 29% to 43% (distal tibia, p < .01) greater trabecular bone strength, as assessed by Young’s moduli, in the Chinese-American versus the white group. The observation that Chinese-American women have a major microstructural advantage over white women may help to explain why their risk of fracture is lower despite their lower BMD. PMID:21351150

The Acyl Desaturase CER17 Is Involved in Producing Wax Unsaturated Primary Alcohols and Cutin Monomers.

PubMed

Yang, Xianpeng; Zhao, Huayan; Kosma, Dylan K; Tomasi, Pernell; Dyer, John M; Li, Rongjun; Liu, Xiulin; Wang, Zhouya; Parsons, Eugene P; Jenks, Matthew A; Lü, Shiyou

2017-02-01

We report n-6 monounsaturated primary alcohols (C 26:1 , C 28:1 , and C 30:1 homologs) in the cuticular waxes of Arabidopsis (Arabidopsis thaliana) inflorescence stem, a class of wax not previously reported in Arabidopsis. The Arabidopsis cer17 mutant was completely deficient in these monounsaturated alcohols, and CER17 was found to encode a predicted ACYL-COENZYME A DESATURASE LIKE4 (ADS4). Studies of the Arabidopsis cer4 mutant and yeast variously expressing CER4 (a predicted fatty acyl-CoA reductase) with CER17/ADS4, demonstrated CER4's principal role in synthesis of these monounsaturated alcohols. Besides unsaturated alcohol deficiency, cer17 mutants exhibited a thickened and irregular cuticle ultrastructure and increased amounts of cutin monomers. Although unsaturated alcohols were absent throughout the cer17 stem, the mutation's effects on cutin monomers and cuticle ultrastructure were much more severe in distal than basal stems, consistent with observations that the CER17/ADS4 transcript was much more abundant in distal than basal stems. Furthermore, distal but not basal stems of a double mutant deficient for both CER17/ADS4 and LONG-CHAIN ACYL-COA SYNTHETASE1 produced even more cutin monomers and a thicker and more disorganized cuticle ultrastructure and higher cuticle permeability than observed for wild type or either mutant parent, indicating a dramatic genetic interaction on conversion of very long chain acyl-CoA precursors. These results provide evidence that CER17/ADS4 performs n-6 desaturation of very long chain acyl-CoAs in both distal and basal stems and has a major function associated with governing cutin monomer amounts primarily in the distal segments of the inflorescence stem. © 2017 American Society of Plant Biologists. All Rights Reserved.

Oesophageal tone and sensation in the transition zone between proximal striated and distal smooth muscle oesophagus.

PubMed

Karamanolis, G; Stevens, W; Vos, R; Tack, J; Clave, P; Sifrim, D

2008-04-01

Previous studies have shown that the proximal striated muscle oesophagus is less compliant and more sensitive than the distal smooth muscle oesophagus. Conventional and high resolution manometry described a transition zone between striated and smooth muscle oesophagus. We aimed to evaluate oesophageal tone and sensitivity at the transition zone of oesophagus in healthy volunteers. In 18 subjects (seven men, mean age: 28 years) an oesophageal barostat study was performed. Tone and sensitivity were assessed using stepwise isobaric distensions with the balloon located at transition zone and at distal oesophagus in random order. To study the effect induced on transition zone by a previous distension at the distal oesophagus and vice versa, identical protocol was repeated after 7 days with inverted order. Initial distension of a region is referred to as 'naïf' distension and distension of a region following the distension of the other segment as 'primed' distension. Assessment of three oesophageal symptoms (chest pain, heartburn and 'other') was obtained at the end of every distension step. Compliance was significantly higher in the transition zone than in the distal oesophagus (1.47 +/- 0.14 vs 1.09 +/- 0.09 mL mmHg(-1), P = 0.03) after 'naif' distensions. This difference was not observed during 'primed' distensions. Higher sensitivity at transition zone level was found in 11/18 (61%) subjects compared to 6/18 (33%, P < 0.05) at smooth muscle oesophagus. Chest pain and 'other' symptom were more often induced by distention of the transition zone, whereas heartburn was equally triggered by distension of either region. The transition zone is more complaint and more sensitive than smooth muscle oesophagus.

Maintenance of Distal Intestinal Structure in the Face of Prolonged Fasting: A Comparative Examination of Species From Five Vertebrate Classes.

PubMed

McCue, Marshall D; Passement, Celeste A; Meyerholz, David K

2017-12-01

It was recently shown that fasting alters the composition of microbial communities residing in the distal intestinal tract of animals representing five classes of vertebrates [i.e., fishes (tilapia), amphibians (toads), reptiles (leopard geckos), birds (quail), and mammals (mice)]. In this study, we tested the hypothesis that the extent of tissue reorganization in the fasted distal intestine was correlated with the observed changes in enteric microbial diversity. Segments of intestine adjacent to those used for the microbiota study were examined histologically to quantify cross-sectional and mucosal surface areas and thicknesses of mucosa, submucosa, and tunica muscularis. We found no fasting-induced differences in the morphology of distal intestines of the mice (3 days), quail (7 days), or geckos (28 days). The toads, which exhibited a general increase in phylogenetic diversity of their enteric microbiota with fasting, also exhibited reduced mucosal circumference at 14 and 21 days of fasting. Tilapia showed increased phylogenetic diversity of their enteric microbiota, and showed a thickened tunica muscularis at 21 days of fasting; but this morphological change was not related to microbial diversity or absorptive surface area, and thus, is unlikely to functionally match the changes in their microbiome. Given that fasting caused significant increases and reductions in the enteric microbial diversity of mice and quail, respectively, but no detectable changes in distal intestine morphology, we conclude that reorganization is not the primary factor shaping changes in microbial diversity within the fasted colon, and the observed modest structural changes are more related to the fasted state. Anat Rec, 300:2208-2219, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Splanchnic preganglionic neurons in man. III. Morphometry of myelinated fibers of rami communicantes.

PubMed

Low, P A; Dyck, P J

1978-01-01

The myelinated fiber (MF) composition of T6-T8 Rami Communicantes were obtained in 9 healthy persons of various ages. The textbook picture that distal rami (DR) contain all of the myelinated fibers and therefore are white, while proximal rami (PR) contain none of them and therefore are grey must be modified. We found that DR usually contained abundant MFs and that PR concordance was found between segmental numbers of intermediolateral nuclei cytons, ventral root small myelinated fibers (SMFs), and rami total small MFs to suggest that both rami probably contain the distal myelinated axons of preganglionic autonomic fibers. Finally, there was an attrition of total MFs of rami with age, similar to what we had previously found for ILC cytons and for root SMFs. The decrease in number of pre-ganglionic autonomic neurons with age is thought to be of sufficient magnitude to account for the dysautonomia of the elderly.

Protein sorting, targeting and trafficking in photoreceptor cells

PubMed Central

Pearring, Jillian N.; Salinas, Raquel Y.; Baker, Sheila A.; Arshavsky, Vadim Y.

2013-01-01

Vision is the most fundamental of our senses initiated when photons are absorbed by the rod and cone photoreceptor neurons of the retina. At the distal end of each photoreceptor resides a light-sensing organelle, called the outer segment, which is a modified primary cilium highly enriched with proteins involved in visual signal transduction. At the proximal end, each photoreceptor has a synaptic terminal, which connects this cell to the downstream neurons for further processing of the visual information. Understanding the mechanisms involved in creating and maintaining functional compartmentalization of photoreceptor cells remains among the most fascinating topics in ocular cell biology. This review will discuss how photoreceptor compartmentalization is supported by protein sorting, targeting and trafficking, with an emphasis on the best-studied cases of outer segment-resident proteins. PMID:23562855

Composite drill pipe and method for forming same

DOEpatents

Leslie, James C; Leslie, II, James C; Heard, James; Truong, Liem V; Josephson, Marvin

2012-10-16

A lightweight and durable drill pipe string capable of short radius drilling formed using a composite pipe segment formed to include tapered wall thickness ends that are each defined by opposed frustoconical surfaces conformed for self-aligning receipt and intimate bonding contact within an annular space between corresponding surfaces of a coaxially nested set of metal end pieces and a set of nonconductive sleeves. The distal peripheries of the nested end pieces and sleeves are then welded to each other and the sandwiched and bonded portions are radially pinned. The composite segment may include imbedded conductive leads and the axial end portions of the end pieces are shaped to form a threaded joint with the next pipe assembly that includes contact rings in the opposed surfaces of the pipe joint for contact together.

A Comprehensive Study of Internal Distraction Plating, an Alternative Method for Distal Radius Fractures.

PubMed

Jain, Mohit J; Mavani, Kinjal J

2016-12-01

The management of highly comminuted distal radius fractures still remains a major treatment challenge. Articular comminution and compromised bone quality are the culprits. One novel approach is the technique of Internal Distraction Plating which involves "bridging" the fracture with the use of a standard 3.5mm plate applied dorsally in distraction from the radius, proximal to the fracture, to the long finger metacarpal distally, bypassing the comminuted segment. The plate is removed once fracture union has been achieved. The present study was conducted with the aim to evaluate the role of internal dorsal distraction plating as an alternative method in the treatment of fracture distal radius in terms of special indications, technique and outcome. This study was a prospective longitudinal study on 20 patients (mean age 62 years) treated with internal distraction plating for comminuted distal radius fractures with specific indications. Regular follow-ups with standard radiographs and analysis were done upto 24 months. Functional outcome were assessed by DASH Score and the Gartland and Werley demerit score. At final follow-up, all fractures had united and X-rays showed mean palmar tilt of 7°, positive ulnar variance of 0.5mm, radial inclination of 18° and average loss of 2mm of radial height. Mean range of motion values for wrist flexion 46°, extension 50°, pronation 79° and supination 77° At final follow-up, the mean DASH score was 32. 85% patient had excellent to good result as per Gartland and Werley demerit score. This construct has yield satisfactory clinical and radiographic results with these very challenging injuries. The purpose of this study was to report the radiographic and the functional outcomes of treatment with this technique. External fixator and volar plating in communited distal end radius fractures are not always satisfactory in old age with osteoporotic bone because of complications associated with them. The current technique represents an alternative that provides union of the comminuted distal radius fracture with anatomical alignment, optimal range of motion and with minimal clinical disability.

The perforating branches of the P1 segment of the posterior cerebral artery.

PubMed

Kaya, Ahmet Hilmi; Dagcinar, Adnan; Ulu, Mustafa Onur; Topal, Arif; Bayri, Yasar; Ulus, Aykan; Kopuz, Cem; Sam, Bulent

2010-01-01

The perforating branches of the P1 segment of the posterior cerebral artery are vulnerable to injury. Because of their close proximity to the basilar artery, the vulnerability occurs especially during surgical interventions for vascular pathologies such as basilar apex aneurysms. Therefore, extensive knowledge of the microsurgical anatomy of this area is mandatory to prevent poor post-operative outcomes. We microscopically examined 28 P1 segments obtained from 14 adult fresh cadaver brains (6 silicone injected, 8 freshly examined). The P1 segments ranged between 2.8mm and 12.2mm (mean 6.8mm) in length with a mean outer diameter of 1.85 mm (range 0.8-4.5mm). All 94 thalamoperforating branches identified in 27 P1 segments (mean 3.35 branches per segment) arose from the postero-superior aspect of P1 and were the most proximally originating branch in nearly all specimens (96.4%). In addition in 28 P1s, 12 short circumflex arteries (42.8%; mean 0.42 branches per segment), 16 long circumflex arteries (57.1%; mean 0.57 branches per segment) and 10 medial posterior choroidal arteries (35.7%; mean 0.35 branches per segment) were identified and all originated from the posterior or postero-inferior surface of the P1 segment. When the P1 segment had more than one type of branch, it was the short circumflex arteries that were always more proximal in origin than the others. The medial posterior choroidal arteries were always more distal in origin. All three branches were not observed together in any of the P1 segments. The findings in this, and future, anatomical studies may help to reduce the post-surgical morbidity and mortality rates after surgery for posterior circulation aneurysms. Copyright (c) 2009 Elsevier Ltd. All rights reserved.

Automated cortical bone segmentation for multirow-detector CT imaging with validation and application to human studies

PubMed Central

Li, Cheng; Jin, Dakai; Chen, Cheng; Letuchy, Elena M.; Janz, Kathleen F.; Burns, Trudy L.; Torner, James C; Levy, Steven M.; Saha, Punam K

2015-01-01

Purpose: Cortical bone supports and protects human skeletal functions and plays an important role in determining bone strength and fracture risk. Cortical bone segmentation at a peripheral site using multirow-detector CT (MD-CT) imaging is useful for in vivo assessment of bone strength and fracture risk. Major challenges for the task emerge from limited spatial resolution, low signal-to-noise ratio, presence of cortical pores, and structural complexity over the transition between trabecular and cortical bones. An automated algorithm for cortical bone segmentation at the distal tibia from in vivo MD-CT imaging is presented and its performance and application are examined. Methods: The algorithm is completed in two major steps—(1) bone filling, alignment, and region-of-interest computation and (2) segmentation of cortical bone. After the first step, the following sequence of tasks is performed to accomplish cortical bone segmentation—(1) detection of marrow space and possible pores, (2) computation of cortical bone thickness, detection of recession points, and confirmation and filling of true pores, and (3) detection of endosteal boundary and delineation of cortical bone. Effective generalizations of several digital topologic and geometric techniques are introduced and a fully automated algorithm is presented for cortical bone segmentation. Results: An accuracy of 95.1% in terms of volume of agreement with manual outlining of cortical bone was observed in human MD-CT scans, while an accuracy of 88.5% was achieved when compared with manual outlining on postregistered high resolution micro-CT imaging. An intraclass correlation coefficient of 0.98 was obtained in cadaveric repeat scans. A pilot study was conducted to describe gender differences in cortical bone properties. This study involved 51 female and 46 male participants (age: 19–20 yr) from the Iowa Bone Development Study. Results from this pilot study suggest that, on average after adjustment for height and weight differences, males have thicker cortex (mean difference 0.33 mm and effect size 0.92 at the anterior region) with lower bone mineral density (mean difference −28.73 mg/cm3 and effect size 1.35 at the posterior region) as compared to females. Conclusions: The algorithm presented is suitable for fully automated segmentation of cortical bone in MD-CT imaging of the distal tibia with high accuracy and reproducibility. Analysis of data from a pilot study demonstrated that the cortical bone indices allow quantification of gender differences in cortical bone from MD-CT imaging. Application to larger population groups, including those with compromised bone, is needed. PMID:26233184

Tephra dispersal during the Campanian Ignimbrite (Italy) eruption: implications for ultra-distal ash transport during the large caldera-forming eruption

NASA Astrophysics Data System (ADS)

Smith, Victoria C.; Isaia, Roberto; Engwell, Sam L.; Albert, Paul. G.

2016-06-01

The Campanian Ignimbrite eruption dispersed ash over much of the central eastern Mediterranean Sea and eastern Europe. The eruption started with a Plinian phase that was followed by a series of pyroclastic density currents (PDCs) associated with the collapse of the Plinian column and the caldera. The glass compositions of the deposits span a wide geochemical range, but the Plinian fallout and PDCs associated with column collapse, the Lower Pumice Flow, only erupted the most evolved compositions. The later PDCs, the Breccia Museo and Upper Pumice Flow, erupted during and after caldera collapse, tap a less evolved component, and intermediate compositions that represent mixing between the end-members. The range of glass compositions in the Campanian Ignimbrite deposits from sites across the central and eastern Mediterranean Sea allow us to trace the dispersal of the different phases of this caldera-forming eruption. We map the fallout from the Plinian column and the plumes of fine material associated with the PDCs (co-PDCs) across the entire dispersal area. This cannot be done using the usual grain-size methods as deposits in these distal regions do not retain characteristics that allow attribution to either the Plinian or co-PDC phases. The glass compositions of the tephra at ultra-distal sites (>1500 km from the vent) match those of the uppermost PDC units, suggesting that most of the ultra-distal dispersal was associated with the late co-PDC plume that was generated during caldera collapse.

Structural analysis of kinetic folding intermediates for a TIM barrel protein, indole-3-glycerol phosphate synthase, by hydrogen exchange mass spectrometry and Gō-model simulation

PubMed Central

Gu, Zhenyu; Rao, Maithreyi K.; Forsyth, William R.

2009-01-01

The structures of partially-folded states appearing during the folding of a (βα)8 TIM barrel protein, the indole-3-glycerol phosphate synthase from S. solfataricus (sIGPS), was assessed by hydrogen exchange mass spectrometry (HX-MS) and Gō-model simulations. HX-MS analysis of the peptic peptides derived from the pulse-labeled product of the sub-millisecond folding reaction from the urea-denatured state revealed strong protection in the (βα)4 region, modest protection in the neighboring (βα)1–3 and (βα)5β6 segments and no significant protection in the remaining N- and C-terminal segments. These results demonstrate that this species is not a collapsed form of the unfolded state under native-favoring conditions nor is it the native state formed via fast-track folding. However, the striking contrast of these results with the strong protection observed in the (βα)2–5β6 region after 5 s of folding demonstrates that these species represent kinetically-distinct folding intermediates that are not identical as previously thought. A re-examination of the kinetic folding mechanism by chevron analysis of fluorescence data confirmed distinct roles for these two species: the burst-phase intermediate is predicted to be a misfolded, off-pathway intermediate while the subsequent 5 s intermediate corresponds to an on-pathway equilibrium intermediate. Comparison with the predictions using a Cα Gō-model simulation of the kinetic folding reaction for sIGPS shows good agreement with the core of structure offering protection against exchange in the on-pathway intermediate(s). Because the native-centric Gō-model simulations do not explicitly include sequence-specific information, the simulation results support the hypothesis that the topology of TIM barrel proteins is a primary determinant of the folding free energy surface for the productive folding reaction. The early misfolding reaction must involve aspects of non-native structure not detected by the Gō-model simulation. PMID:17942114

Association of ST segment depression >5 min after exercise testing with severity of coronary artery disease.

PubMed

Shaikh, Ayaz Hussain; Hanif, Bashir; Siddiqui, Adeel M; Shahab, Hunaina; Qazi, Hammad Ali; Mujtaba, Iqbal

2010-04-01

To determine the association of prolonged ST segment depression after an exercise test with severity of coronary artery disease. A cross sectional study of 100 consecutive patients referred to the cardiology laboratory for stress myocardial perfusion imaging (MPI) conducted between April-August 2008. All selected patients were monitored until their ST segment depression was recovered to baseline. ST segment recovery time was categorized into less and more than 5 minutes. Subsequent gated SPECT-MPI was performed and stratified according to severity of perfusion defect. Association was determined between post exercise ST segment depression recovery time (<5 minutes and >5 minutes) and severity of perfusion defect on MPI. The mean age of the patients was 57.12 +/- 9.0 years. The results showed statistically insignificant association (p > 0.05) between ST segment recovery time of <5 minutes and >5 minutes with low, intermediate or high risk MPI. Our findings suggest that the commonly used cut-off levels used in literature for prolonged, post exercise ST segment depression (>5 minutes into recovery phase) does not correlate with severity of ischaemia based on MPI results.

In vitro-analysis of kinematics and intradiscal pressures in cervical arthroplasty versus fusion--A biomechanical study in a sheep model with two semi-constrained prosthesis.

PubMed

Daentzer, Dorothea; Welke, Bastian; Hurschler, Christof; Husmann, Nathalie; Jansen, Christina; Flamme, Christian Heinrich; Richter, Berna Ida

2015-03-24

As an alternative technique to arthrodesis of the cervical spine, total disc replacement (TDR) has increasingly been used with the aim of restoration of the physiological function of the treated and adjacent motions segments. The purpose of this experimental study was to analyze the kinematics of the target level as well as of the adjacent segments, and to measure the pressures in the proximal and distal disc after arthrodesis as well as after arthroplasty with two different semi-constrained types of prosthesis. Twelve cadaveric ovine cervical spines underwent polysegmental (C2-5) multidirectional flexibility testing with a sensor-guided industrial serial robot. Additionally, pressures were recorded in the proximal and distal disc. The following three conditions were tested: (1) intact specimen, (2) single-level arthrodesis C3/4, (3) single-level TDR C3/4 using the Discover® in the first six specimens and the activ® C in the other six cadavers. Statistical analysis was performed for the total range of motion (ROM), the intervertebral ROM (iROM) and the intradiscal pressures (IDP) to compare both the three different conditions as well as the two disc prosthesis among each other. The relative iROM in the target level was always lowered after fusion in the three directions of motion. In almost all cases, the relative iROM of the adjacent segments was almost always higher compared to the physiologic condition. After arthroplasty, we found increased relative iROM in the treated level in comparison to intact state in almost all cases, with relative iROM in the adjacent segments observed to be lower in almost all situations. The IDP in both adjacent discs always increased in flexion and extension after arthrodesis. In all but five cases, the IDP in each of the adjacent level was decreased below the values of the intact specimens after TDR. Overall, in none of the analyzed parameters were statistically significantly differences between both types of prostheses investigated. The results of this biomechanical study indicate that single-level implantation of semi-constrained TDR lead to a certain hypermobility in the treated segments with lowering the ROM in the adjacent levels in almost all situations.

Biomechanical Characteristics and Determinants of Instep Soccer Kick

PubMed Central

Kellis, Eleftherios; Katis, Athanasios

2007-01-01

Good kicking technique is an important aspect of a soccer player. Therefore, understanding the biomechanics of soccer kicking is particularly important for guiding and monitoring the training process. The purpose of this review was to examine latest research findings on biomechanics of soccer kick performance and identify weaknesses of present research which deserve further attention in the future. Being a multiarticular movement, soccer kick is characterised by a proximal-to-distal motion of the lower limb segments of the kicking leg. Angular velocity is maximized first by the thigh, then by the shank and finally by the foot. This is accomplished by segmental and joint movements in multiple planes. During backswing, the thigh decelerates mainly due to a motion-dependent moment from the shank and, to a lesser extent, by activation of hip muscles. In turn, forward acceleration of the shank is accomplished through knee extensor moment as well as a motion-dependent moment from the thigh. The final speed, path and spin of the ball largely depend on the quality of foot-ball contact. Powerful kicks are achieved through a high foot velocity and coefficient of restitution. Preliminary data indicate that accurate kicks are achieved through slower kicking motion and ball speed values. Key pointsSoccer kick is achieved through segmental and joint rotations in multiple planes and via the proximal-to-distal sequence of segmental angular velocities until ball impact. The quality of ball - foot impact and the mechanical behavior of the foot are also important determinants of the final speed, path and spin of the ball.Ball speed values during the maximum instep kick range from 18 to 35 msec-1 depending on various factors, such as skill level, age, approach angle and limb dominance.The main bulk of biomechanics research examined the biomechanics of powerful kicks, mostly under laboratory conditions. A powerful kick is characterized by the achievement of maximal ball speed. However, maximal ball speed does not guarantee a successful kick: in each case, the ball must reach the target. As already explained, when the player is instructed to hit the ball accurately, joint and segment velocities are lower as opposed to a fast and powerful kick performance. It is therefore apparent that future research should focus on biomechanics of fast but accurate kicking. PMID:24149324

Human whole-body reaching in normal gravity and microgravity reveals a strong temporal coordination between postural and focal task components.

PubMed

Patron, Jerome; Stapley, Paul; Pozzo, Thierry

2005-08-01

Previous experiments by our group in normal gravity (1 G) have revealed spatial relationships between postural and focal components of whole-body reaching and pointing movements. We suggested that these relationships could be explained partly through the use of gravity to displace the CoM and attain the object or target position. In this study we compared human whole-body reaching in 1 G and microgravity (0 G) in order to more fully investigate how gravity contributes to strategies adopted for task execution and to determine possible invariant temporal relationships between multiple segments. Whole-body reaching movements made from the standing position in two experimental conditions of execution speed (naturally paced and as fast as possible) were recorded during periods of 1 G and 0 G in parabolic flight. Overall, at each speed of reaching, movement times were significantly slower when performed in 0 G than in 1 G for two of the three subjects, but all subjects were able to produce significantly faster movements in 0 G than in 1 G. Despite similar general trends across subjects observed in 1 G, angular displacements of reaching movements performed in 0 G differed greatly between subjects. There were changes at all joints, but above all at the shoulder and the ankle. However, despite a high intersubject and intratrial variability in 0 G, in both gravity conditions all subjects demonstrated times to peak curvilinear velocity for the finger (end effector) and the whole-body centre of mass (CoM) that coincided, regardless of the speed of execution. Moreover, cross-correlations between multiple segment curvilinear velocities and those of the CoM revealed tight, highly correlated temporal relationships between segments proximal to the CoM (which was expected). However, for more distal segments, the correlations were weaker, and the movements lagged behind movements of the CoM. The major and most interesting finding of this study was that although the finger was the most distal within the segment chain, with respect to the CoM, it was highly correlated with the CoM (0.99--0.98, all conditions) and with no time lag. Despite the large intersubject and inter-environmental variability recorded in this study, temporal relationships between postural task components (CoM displacements) and those of the focal movement (end-effector trajectory) were consistently conserved.

Hair analysis to monitor abuse of analgesic combinations containing butalbital and propyphenazone.

PubMed

Ferrari, Anna; Tiraferri, Ilaria; Palazzoli, Federica; Verri, Patrizia; Vandelli, Daniele; Marchesi, Filippo; Ciccarese, Michela; Licata, Manuela

2015-11-10

Butalbital, a barbiturate, is present in analgesic combinations used by headache sufferers. Overuse/abuse of these combinations may cause dependence, chronic migraine, and medication-overuse headache (MOH). MOH is difficult to manage: it improves interrupting analgesic overuse, but requires monitoring, because relapses are frequent. A gas chromatography-mass spectrometry (GC-MS) method for hair analysis has been developed and validated to document abuse of an analgesic combination containing butalbital and propyphenazone by a patient with MOH. For over ten years the patient managed her headache using eight suppositories/day of an analgesic combination containing butalbital 150mg, caffeine 75mg, and propyphenazone 375mg per suppository. An outpatient detoxification treatment was carried out. After three weeks, the patient reduced the consumption to one suppository/day. At the first control visit, after three months from the beginning of detoxification, the patient increased the use of the combination to four suppositories/day and at the second control visit, after seven months from the beginning of detoxification, she was back to eight suppositories/day. At the two control visits, a hair sample was taken for determination of butalbital and propyphenazone. Moreover blood and urine samples for determination of butalbital were drawn at the beginning of detoxification treatment and at the two control visits. With the segmental analysis of two hair samples the medication history of ten months could be estimated. In the first hair sample, collected at the first control visit, in the distal segment, butalbital and propyphenazone concentrations were, respectively, 17.5ng/mg and 56.0ng/mg, confirming the prolonged abuse; in the proximal segment, concurrently with the detoxification treatment, butalbital and propyphenazone concentrations had reduced respectively to 5.45ng/mg and 11.1ng/mg. The second hair sample, collected at the second control visit, proved the fair course of the detoxification treatment in the distal segment and signalled relapse in the abuse of the analgesic combination in the proximal segment. In the clinical context, hair analysis can be advantageously used to monitor the abuse of analgesic combinations with butalbital, common among headache patients. The validation data showed that GC-MS method developed for determination of butalbital and propyphenazone was rapid, highly sensitive, specific and selective. Copyright © 2015 Elsevier B.V. All rights reserved.

[The monorail system--bone segment transport over unreamed interlocking nails].

PubMed

Oedekoven, G; Jansen, D; Raschke, M; Claudi, B F

1996-11-01

A treatment protocol is demonstrated, consisting of an osteotomy, either proximal or distal, of the bone defect with subsequent segmental transport via an anteromedially (tibia) or laterally (femur) mounted AO external fixation over an unreamed interlocking nail (monorail system). Twenty patients were treated by this method with indications as follows: 13 had a segmental bone defect of the tibia, 3 of the femur. Three patients showed post-traumatic and postinfectious leg-length discrepancies and one was treated for hypertrophic non-union of the femur. Defect distance varied between 5 and 18.5 cm and average time for transport was 19,42 days/ cm for the tibial shaft, 15,93 days/cm for the femur. Two patients developed deep infection, which required change of treatment, removing the monorail system and application of an Ilizarov apparatus. Despite complications using the monorail system, all patients healed and no amputations were required. The monorail system can be used as an alternative to the Ilizarov method under certain criteria of patient selection; these criteria are shown by an algorithm for segmental bone defects without infection, respecting the soft-tissue status with or without neurovascular compromise.

Modulation of secretagogue-induced chloride secretion by intracellular bicarbonate.

PubMed

Dagher, P C; Morton, T Z; Joo, C S; Taglietta-Kohlbrecher, A; Egnor, R W; Charney, A N

1994-05-01

We have previously demonstrated inhibition of basal Cl- secretion by intracellular bicarbonate concentration ([HCO3-]i) in rat distal colon. We now examined whether secretagogue-induced Cl- secretion is inhibited by [HCO3-]i as well. Stripped segments of distal colon from male Sprague-Dawley rats and the colon tumor cell line T84 were studied. Flux measurements were performed in the Ussing chamber under short-circuit conditions. [HCO3-]i was calculated from intracellular pH (pHi) values that were estimated with the pH-sensitive dye 2',7'-bis(2-carboxyethyl)-5(6)-carboxyfluorescein. Dibutyryl adenosine 3',5'-cyclic monophosphate (cAMP) and carbachol were used as secretagogues. In both distal colon and T84 cells, [HCO3-]i did not affect cAMP-induced Cl- secretion. However, carbachol-induced secretion was inhibited by [HCO3-]i; in rat colon, Cl- secretion decreased from 2.3 to 1.5 mueq.cm-2.h-1 when [HCO3-]i was increased from 15.0 to 28.4 mM (P < 0.05). In T84 cells, the change in short-circuit current decreased from 8.1 to 1.1 microA/cm2 over a range of [HCO3-]i from 0 to 15.6 mM (P < 0.001). We conclude that [HCO3-]i is an important modulator of carbachol-stimulated Cl- secretion in both rat distal colon and the T84 cell line. cAMP-mediated secretion is not affected by [HCO3-]i.

Surgical Strategy and Techniques for Low-Profile Dorsal Plating in Treating Dorsally Displaced Unstable Distal Radius Fractures

PubMed Central

Hamada, Yoshitaka; Gotani, Hiroyuki; Hibino, Naohito; Tanaka, Yoshitaka; Satoh, Ryousuke; Sasaki, Kousuke; Kanchanathepsak, Thepparat

2016-01-01

Background The low-profile dorsal locking plating (DLP) technique is useful for treating dorsally comminuted intra-articular distal radius fractures; however, due to the complications associated with DLP, the technique is not widely used. Methods A retrospective review of 24 consecutive cases treated with DLP were done. Results All cases were classified into two types by surgical strategy according to the fracture pattern. In type 1, there is a volar fracture line distal to the watershed line in the dorsally displaced fragment, and this type is treated by H-framed DLP. In type 2, the displaced dorsal die-punch fragment is associated with a minimally displaced styloid shearing fracture or a transverse volar fracture line. We found that the die-punch fragment was reduced by the buttress effect of small l-shaped DLP after stabilization of the styloid shearing for the volar segment by cannulated screws from radial styloid processes. At 6 months after surgery, outcomes were good or excellent based on the modified Mayo wrist scores with no serious complications except one case. The mean range of motion of each type was as follows: the palmar flexion was 50, 65 degrees, dorsiflexion was 70, 75 degrees, supination was 85, 85 degrees, and pronation was 80, 80 degrees; in type 1 and 2, respectively. Conclusion DLP is a useful technique for the treatment of selected cases of dorsally displaced, comminuted intra-articular fractures of the distal radius with careful soft tissue coverage. PMID:28428920

Dual-threshold segmentation using Arimoto entropy based on chaotic bee colony optimization

NASA Astrophysics Data System (ADS)

Li, Li

2018-03-01

In order to extract target from complex background more quickly and accurately, and to further improve the detection effect of defects, a method of dual-threshold segmentation using Arimoto entropy based on chaotic bee colony optimization was proposed. Firstly, the method of single-threshold selection based on Arimoto entropy was extended to dual-threshold selection in order to separate the target from the background more accurately. Then intermediate variables in formulae of Arimoto entropy dual-threshold selection was calculated by recursion to eliminate redundant computation effectively and to reduce the amount of calculation. Finally, the local search phase of artificial bee colony algorithm was improved by chaotic sequence based on tent mapping. The fast search for two optimal thresholds was achieved using the improved bee colony optimization algorithm, thus the search could be accelerated obviously. A large number of experimental results show that, compared with the existing segmentation methods such as multi-threshold segmentation method using maximum Shannon entropy, two-dimensional Shannon entropy segmentation method, two-dimensional Tsallis gray entropy segmentation method and multi-threshold segmentation method using reciprocal gray entropy, the proposed method can segment target more quickly and accurately with superior segmentation effect. It proves to be an instant and effective method for image segmentation.

Testing the effectiveness and the contribution of experimental supercharge (reversed) end-to-side nerve transfer.

PubMed

Nadi, Mustafa; Ramachandran, Sudheesh; Islam, Abir; Forden, Joanne; Guo, Gui Fang; Midha, Rajiv

2018-05-18

OBJECTIVE Supercharge end-to-side (SETS) transfer, also referred to as reverse end-to-side transfer, distal to severe nerve compression neuropathy or in-continuity nerve injury is gaining clinical popularity despite questions about its effectiveness. Here, the authors examined SETS distal to experimental neuroma in-continuity (NIC) injuries for efficacy in enhancing neuronal regeneration and functional outcome, and, for the first time, they definitively evaluated the degree of contribution of the native and donor motor neuron pools. METHODS This study was conducted in 2 phases. In phase I, rats (n = 35) were assigned to one of 5 groups for unilateral sciatic nerve surgeries: group 1, tibial NIC with distal peroneal-tibial SETS; group 2, tibial NIC without SETS; group 3, intact tibial and severed peroneal nerves; group 4, tibial transection with SETS; and group 5, severed tibial and peroneal nerves. Recovery was evaluated biweekly using electrophysiology and locomotion tasks. At the phase I end point, after retrograde labeling, the spinal cords were analyzed to assess the degree of neuronal regeneration. In phase II, 20 new animals underwent primary retrograde labeling of the tibial nerve, following which they were assigned to one of the following 3 groups: group 1, group 2, and group 4. Then, secondary retrograde labeling from the tibial nerve was performed at the study end point to quantify the native versus donor regenerated neuronal pool. RESULTS In phase I studies, a significantly increased neuronal regeneration in group 1 (SETS) compared with all other groups was observed, but with modest (nonsignificant) improvement in electrophysiological and behavioral outcomes. In phase II experiments, the authors discovered that secondary labeling in group 1 was predominantly contributed from the donor (peroneal) pool. Double-labeling counts were dramatically higher in group 2 than in group 1, suggestive of hampered regeneration from the native tibial motor neuron pool across the NIC segment in the presence of SETS. CONCLUSIONS SETS is indeed an effective strategy to enhance axonal regeneration, which is mainly contributed by the donor neuronal pool. Moreover, the presence of a distal SETS coaptation appears to negatively influence neuronal regeneration across the NIC segment. The clinical significance is that SETS should only employ synergistic donors, as the use of antagonistic donors can downgrade recovery.

On the evaluation of segmentation editing tools

PubMed Central

Heckel, Frank; Moltz, Jan H.; Meine, Hans; Geisler, Benjamin; Kießling, Andreas; D’Anastasi, Melvin; dos Santos, Daniel Pinto; Theruvath, Ashok Joseph; Hahn, Horst K.

2014-01-01

Abstract. Efficient segmentation editing tools are important components in the segmentation process, as no automatic methods exist that always generate sufficient results. Evaluating segmentation editing algorithms is challenging, because their quality depends on the user’s subjective impression. So far, no established methods for an objective, comprehensive evaluation of such tools exist and, particularly, intermediate segmentation results are not taken into account. We discuss the evaluation of editing algorithms in the context of tumor segmentation in computed tomography. We propose a rating scheme to qualitatively measure the accuracy and efficiency of editing tools in user studies. In order to objectively summarize the overall quality, we propose two scores based on the subjective rating and the quantified segmentation quality over time. Finally, a simulation-based evaluation approach is discussed, which allows a more reproducible evaluation without the need for human input. This automated evaluation complements user studies, allowing a more convincing evaluation, particularly during development, where frequent user studies are not possible. The proposed methods have been used to evaluate two dedicated editing algorithms on 131 representative tumor segmentations. We show how the comparison of editing algorithms benefits from the proposed methods. Our results also show the correlation of the suggested quality score with the qualitative ratings. PMID:26158063

Black strings, low viscosity fluids, and violation of cosmic censorship.

PubMed

Lehner, Luis; Pretorius, Frans

2010-09-03

We describe the behavior of 5-dimensional black strings, subject to the Gregory-Laflamme instability. Beyond the linear level, the evolving strings exhibit a rich dynamics, where at intermediate stages the horizon can be described as a sequence of 3-dimensional spherical black holes joined by black string segments. These segments are themselves subject to a Gregory-Laflamme instability, resulting in a self-similar cascade, where ever-smaller satellite black holes form connected by ever-thinner string segments. This behavior is akin to satellite formation in low-viscosity fluid streams subject to the Rayleigh-Plateau instability. The simulation results imply that the string segments will reach zero radius in finite asymptotic time, whence the classical space-time terminates in a naked singularity. Since no fine-tuning is required to excite the instability, this constitutes a generic violation of cosmic censorship.

Ca2+ Receptor, Prostate Cancer, and Bone Metastases

DTIC Science & Technology

2005-03-01

calcium receptor cDNAs. J Biol Chem 270: 12919-12925, 1995. 3. Brown EM, Gamba G, Riccardi D, Lombardi M, Butters R, Kifor 0, Sun A, Hediger MA, Lytton J...Hrol FA , Vassilev PhL, Quinn s, and le.bert SC, G- TOE-p as a result of decreased bone resorption. protein-coupiad. extracelluar Ca zrksensing receptor...bmne cells, several EDTA. FBS was obtainod from Gemini Bio -Produets (Cab nephron segments other than thf distal tubule, and many abasas, CA), and

Coil embolization of an aneurysmal type B dissection persistent false lumen after visceral hybrid repair.

PubMed

Riga, Celia; Bicknell, Colin; Jenkins, Michael; Hamady, Mohamad

2009-01-01

Complex aortic dissections with subsequent dilatation may be managed by using a visceral hybrid approach. In some cases, however, there is substantial retrograde blood flow into the false lumen, leaving a pressurized aneurysmal segment. The authors describe a novel treatment method whereby successful seal of a distal type 1 endoleak was achieved with coil embolization and a liquid injectable embolic agent. The patient was followed up for 2 years without further aortic dilatation or complications.

Inhibiting nucleation of amyloid structure in a huntingtin fragment by targeting α-helix rich oligomeric intermediates

PubMed Central

Mishra, Rakesh; Jayaraman, Murali; Roland, Bartholomew P.; Landrum, Elizabeth; Fullam, Timothy; Kodali, Ravindra; Thakur, Ashwani K.; Arduini, Irene; Wetzel, Ronald

2011-01-01

Although oligomeric intermediates are transiently formed in almost all known amyloid assembly reactions, their mechanistic roles are poorly understood. Recently we demonstrated a critical role for the 17 amino acid N-terminal segment (httNT) of huntingtin (htt) in oligomer-mediated amyloid assembly of htt N-terminal fragments. In this mechanism, the httNT segment forms the α-helix rich core of the oligomers, leaving most or all of each polyglutamine (polyQ) segment disordered and solvent-exposed. Nucleation of amyloid structure occurs within this local high concentration of disordered polyQ. Here we demonstrate the kinetic importance of httNT self-assembly by describing inhibitory httNT-containing peptides that appear to work by targeting nucleation within the oligomer fraction. These molecules inhibit amyloid nucleation by forming mixed oligomers with the httNT domains of polyQ-containing htt N-terminal fragments. In one class of inhibitor, nucleation is passively suppressed due to the reduced local concentration of polyQ within the mixed oligomer. In the other class, nucleation is actively suppressed by a proline-rich polyQ segment covalently attached to httNT. Studies with D-amino acid and scrambled sequence versions of httNT suggest that inhibition activity is strongly linked to the propensity of inhibitory peptides to make amphipathic α-helices. HttNT derivatives with C-terminal cell penetrating peptide segments, also exhibit excellent inhibitory activity. The httNT-based peptides described here, especially those with protease-resistant D-amino acids and/or with cell penetrating sequences, may prove useful as lead therapeutics for inhibiting nucleation of amyloid formation in Huntington’s disease. PMID:22178478

Per rectal endoscopic myotomy for the treatment of adult Hirschsprung's disease: First human case (with video).

PubMed

Bapaye, Amol; Wagholikar, Gajanan; Jog, Sameer; Kothurkar, Aditi; Purandare, Shefali; Dubale, Nachiket; Pujari, Rajendra; Mahadik, Mahesh; Vyas, Viral; Bapaye, Jay

2016-09-01

Hirschsprung's disease (HD) is a congenital disorder characterized by the absence of intrinsic ganglion cells in submucosal and myenteric plexuses of the hindgut; and presents with constipation, intestinal obstruction and/or megacolon. HD commonly involves the rectosigmoid region (short segment HD), although shorter and longer variants of the disease are described. Standard treatment involves pull-through surgery for short segment HD or posterior anorectal myotomy in selected ultrashort segment candidates. Third space endoscopy has evolved during the past few years. Per oral endoscopic myotomy and per oral pyloromyotomy are described for treatment of achalasia cardia and refractory gastroparesis, respectively. Using the same philosophy of muscle/sphincter disruption for spastic bowel segments, per rectal endoscopic myotomy could be considered as a treatment option for short segment HD. A 24-year-old male patient presented with refractory constipation since childhood, and habituated to high-dose laxative combinations. Diagnosis was confirmed as adult short segment HD by barium enema, colonoscopic deep suction mucosal biopsies and anorectal manometry. Histopathology confirmed aganglionosis in the distal 15 cm. By implementing principles of third space endoscopy, per rectal endoscopic myotomy 20 cm in length was successfully carried out. At 24-week follow up, the patient reported significant relief of constipation and associated symptoms. Sigmoidoscopy, anorectal manometry and barium enema confirm improved rectal distensibility and reduced rectal pressures. The present case report describes the first human experience of per rectal endoscopic myotomy for successful treatment of adult short segment HD. © 2016 Japan Gastroenterological Endoscopy Society.

Translocations of chromosome end-segments and facultative heterochromatin promote meiotic ring formation in evening primroses.

PubMed

Golczyk, Hieronim; Massouh, Amid; Greiner, Stephan

2014-03-01

Due to reciprocal chromosomal translocations, many species of Oenothera (evening primrose) form permanent multichromosomal meiotic rings. However, regular bivalent pairing is also observed. Chiasmata are restricted to chromosomal ends, which makes homologous recombination virtually undetectable. Genetic diversity is achieved by changing linkage relations of chromosomes in rings and bivalents via hybridization and reciprocal translocations. Although the structural prerequisite for this system is enigmatic, whole-arm translocations are widely assumed to be the mechanistic driving force. We demonstrate that this prerequisite is genome compartmentation into two epigenetically defined chromatin fractions. The first one facultatively condenses in cycling cells into chromocenters negative both for histone H3 dimethylated at lysine 4 and for C-banding, and forms huge condensed middle chromosome regions on prophase chromosomes. Remarkably, it decondenses in differentiating cells. The second fraction is euchromatin confined to distal chromosome segments, positive for histone H3 lysine 4 dimethylation and for histone H3 lysine 27 trimethylation. The end-segments are deprived of canonical telomeres but capped with constitutive heterochromatin. This genomic organization promotes translocation breakpoints between the two chromatin fractions, thus facilitating exchanges of end-segments. We challenge the whole-arm translocation hypothesis by demonstrating why reciprocal translocations of chromosomal end-segments should strongly promote meiotic rings and evolution toward permanent translocation heterozygosity. Reshuffled end-segments, each possessing a major crossover hot spot, can furthermore explain meiotic compatibility between genomes with different translocation histories.

Translocations of Chromosome End-Segments and Facultative Heterochromatin Promote Meiotic Ring Formation in Evening Primroses[W][OPEN

PubMed Central

Golczyk, Hieronim; Massouh, Amid; Greiner, Stephan

2014-01-01

Due to reciprocal chromosomal translocations, many species of Oenothera (evening primrose) form permanent multichromosomal meiotic rings. However, regular bivalent pairing is also observed. Chiasmata are restricted to chromosomal ends, which makes homologous recombination virtually undetectable. Genetic diversity is achieved by changing linkage relations of chromosomes in rings and bivalents via hybridization and reciprocal translocations. Although the structural prerequisite for this system is enigmatic, whole-arm translocations are widely assumed to be the mechanistic driving force. We demonstrate that this prerequisite is genome compartmentation into two epigenetically defined chromatin fractions. The first one facultatively condenses in cycling cells into chromocenters negative both for histone H3 dimethylated at lysine 4 and for C-banding, and forms huge condensed middle chromosome regions on prophase chromosomes. Remarkably, it decondenses in differentiating cells. The second fraction is euchromatin confined to distal chromosome segments, positive for histone H3 lysine 4 dimethylation and for histone H3 lysine 27 trimethylation. The end-segments are deprived of canonical telomeres but capped with constitutive heterochromatin. This genomic organization promotes translocation breakpoints between the two chromatin fractions, thus facilitating exchanges of end-segments. We challenge the whole-arm translocation hypothesis by demonstrating why reciprocal translocations of chromosomal end-segments should strongly promote meiotic rings and evolution toward permanent translocation heterozygosity. Reshuffled end-segments, each possessing a major crossover hot spot, can furthermore explain meiotic compatibility between genomes with different translocation histories. PMID:24681616

Dual-Force Vaginoplasty for Treatment of Segmental Vaginal Aplasia.

PubMed

El Saman, Ali M; Farag, Mohamad A; Shazly, Sherif A; Noor, Mohamed; Ali, Mohammed K; Othman, Essam R; Khalifa, Mansour; Farghly, Tarek A; El Saman, Dina A

2017-05-01

Vaginal aplasia occurs in 1 in 5,000-10,000 female live births. In this report, we evaluated a novel dual-force vaginoplasty technique for treatment of 11 patients with segmental vaginal aplasia. The principle of the approach is to thin the atretic part between two counteracting forces. The instrument was inserted laparoscopically into the proximal hematocolpos. Two balloon catheters, one for drainage and one for traction, were threaded over the inserter. The traction catheter was then threaded over a silicon tube, leaving the balloon in the proximal portion of the vagina and connecting across the vaginal septum to a fenestrated Teflon olive, which was positioned against the distal surface of the vaginal septum. This created a dual "pushing and pulling" force across the septum, which, over 3-4 days, pulls the upper vaginal pouch down while the vaginal dimple is pushed up. The aplastic segment becomes thin and easy to dilate and permits achievement of vaginal patency. The drainage of the hematocolpos is predominantly through the balloon catheter so postoperative wound management is facilitated. Eleven menarchal girls were diagnosed with segmental vaginal aplasia. The dual-force vaginoplasty was performed on each and was tolerated well with no operative complications. They all reported establishment of the menstrual cycle and significant improvement of pain during follow-up. Creation of a dual pushing-pulling force on the atretic vaginal segment is a feasible short procedure for management of segmental vaginal aplasia.

Segmental Analysis of Chlorprothixene and Desmethylchlorprothixene in Postmortem Hair.

PubMed

Günther, Kamilla Nyborg; Johansen, Sys Stybe; Wicktor, Petra; Banner, Jytte; Linnet, Kristian

2018-06-26

Analysis of drugs in hair differs from their analysis in other tissues due to the extended detection window, as well as the opportunity that segmental hair analysis offers for the detection of changes in drug intake over time. The antipsychotic drug chlorprothixene is widely used, but few reports exist on chlorprothixene concentrations in hair. In this study, we analyzed hair segments from 20 deceased psychiatric patients who had undergone chronic chlorprothixene treatment, and we report hair concentrations of chlorprothixene and its metabolite desmethylchlorprothixene. Three to six 1-cm long segments were analyzed per individual, corresponding to ~3-6 months of hair growth before death, depending on the length of the hair. We used a previously published and fully validated liquid chromatography-tandem mass spectrometry method for the hair analysis. The 10th-90th percentiles of chlorprothixene and desmethylchlorprothixene concentrations in all hair segments were 0.05-0.84 ng/mg and 0.06-0.89 ng/mg, respectively, with medians of 0.21 and 0.24 ng/mg, and means of 0.38 and 0.43 ng/mg. The estimated daily dosages ranged from 28 mg/day to 417 mg/day. We found a significant positive correlation between the concentration in hair and the estimated daily doses for both chlorprothixene (P = 0.0016, slope = 0.0044 [ng/mg hair]/[mg/day]) and the metabolite desmethylchlorprothixene (P = 0.0074). Concentrations generally decreased throughout the hair shaft from proximal to distal segments, with an average reduction in concentration from segment 1 to segment 3 of 24% for all cases, indicating that most of the individuals had been compliant with their treatment. We have provided some guidance regarding reference levels for chlorprothixene and desmethylchlorprothixene concentrations in hair from patients undergoing long-term chlorprothixene treatment.

Segmentation of the heart and major vascular structures in cardiovascular CT images

NASA Astrophysics Data System (ADS)

Peters, J.; Ecabert, O.; Lorenz, C.; von Berg, J.; Walker, M. J.; Ivanc, T. B.; Vembar, M.; Olszewski, M. E.; Weese, J.

2008-03-01

Segmentation of organs in medical images can be successfully performed with shape-constrained deformable models. A surface mesh is attracted to detected image boundaries by an external energy, while an internal energy keeps the mesh similar to expected shapes. Complex organs like the heart with its four chambers can be automatically segmented using a suitable shape variablility model based on piecewise affine degrees of freedom. In this paper, we extend the approach to also segment highly variable vascular structures. We introduce a dedicated framework to adapt an extended mesh model to freely bending vessels. This is achieved by subdividing each vessel into (short) tube-shaped segments ("tubelets"). These are assigned to individual similarity transformations for local orientation and scaling. Proper adaptation is achieved by progressively adapting distal vessel parts to the image only after proximal neighbor tubelets have already converged. In addition, each newly activated tubelet inherits the local orientation and scale of the preceeding one. To arrive at a joint segmentation of chambers and vasculature, we extended a previous model comprising endocardial surfaces of the four chambers, the left ventricular epicardium, and a pulmonary artery trunk. Newly added are the aorta (ascending and descending plus arch), superior and inferior vena cava, coronary sinus, and four pulmonary veins. These vessels are organized as stacks of triangulated rings. This mesh configuration is most suitable to define tubelet segments. On 36 CT data sets reconstructed at several cardiac phases from 17 patients, segmentation accuracies of 0.61-0.80mm are obtained for the cardiac chambers. For the visible parts of the newly added great vessels, surface accuracies of 0.47-1.17mm are obtained (larger errors are asscociated with faintly contrasted venous structures).

Determination of lung segments in computed tomography images using the Euclidean distance to the pulmonary artery

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

Stoecker, Christina; Moltz, Jan H.; Lassen, Bianca

Purpose: Computed tomography (CT) imaging is the modality of choice for lung cancer diagnostics. With the increasing number of lung interventions on sublobar level in recent years, determining and visualizing pulmonary segments in CT images and, in oncological cases, reliable segment-related information about the location of tumors has become increasingly desirable. Computer-assisted identification of lung segments in CT images is subject of this work.Methods: The authors present a new interactive approach for the segmentation of lung segments that uses the Euclidean distance of each point in the lung to the segmental branches of the pulmonary artery. The aim is tomore » analyze the potential of the method. Detailed manual pulmonary artery segmentations are used to achieve the best possible segment approximation results. A detailed description of the method and its evaluation on 11 CT scans from clinical routine are given.Results: An accuracy of 2–3 mm is measured for the segment boundaries computed by the pulmonary artery-based method. On average, maximum deviations of 8 mm are observed. 135 intersegmental pulmonary veins detected in the 11 test CT scans serve as reference data. Furthermore, a comparison of the presented pulmonary artery-based approach to a similar approach that uses the Euclidean distance to the segmental branches of the bronchial tree is presented. It shows a significantly higher accuracy for the pulmonary artery-based approach in lung regions at least 30 mm distal to the lung hilum.Conclusions: A pulmonary artery-based determination of lung segments in CT images is promising. In the tests, the pulmonary artery-based determination has been shown to be superior to the bronchial tree-based determination. The suitability of the segment approximation method for application in the planning of segment resections in clinical practice has already been verified in experimental cases. However, automation of the method accompanied by an evaluation on a larger number of test cases is required before application in the daily clinical routine.« less

The evolving role of the orphan nuclear receptor ftz-f1, a pair-rule segmentation gene.

PubMed

Heffer, Alison; Grubbs, Nathaniel; Mahaffey, James; Pick, Leslie

2013-01-01

Segmentation is a critical developmental process that occurs by different mechanisms in diverse taxa. In insects, there are three common modes of embryogenesis-short-, intermediate-, and long-germ development-which differ in the number of segments specified at the blastoderm stage. While genes involved in segmentation have been extensively studied in the long-germ insect Drosophila melanogaster (Dm), it has been found that their expression and function in segmentation in short- and intermediate-germ insects often differ. Drosophila ftz-f1 encodes an orphan nuclear receptor that functions as a maternally expressed pair-rule segmentation gene, responsible for the formation of alternate body segments during Drosophila embryogenesis. Here we investigated the expression and function of ftz-f1 in the short-germ beetle, Tribolium castaneum (Tc). We found that Tc-ftz-f1 is expressed in stripes in Tribolium embryos. These stripes overlap alternate Tc-Engrailed (Tc-En) stripes, indicative of a pair-rule expression pattern. To test whether Tc-ftz-f1 has pair-rule function, we utilized embryonic RNAi, injecting double-stranded RNA corresponding to Tc-ftz-f1 coding or non-coding regions into early Tribolium embryos. Knockdown of Tc-ftz-f1 produced pair-rule segmentation defects, evidenced by loss of expression of alternate En stripes. In addition, a later role for Tc-ftz-f1 in cuticle formation was revealed. These results identify a new pair-rule gene in Tribolium and suggest that its role in segmentation may be shared among holometabolous insects. Interestingly, while Tc-ftz-f1 is expressed in pair-rule stripes, the gene is ubiquitously expressed in Drosophila embryos. Thus, the pair-rule function of ftz-f1 is conserved despite differences in expression patterns of ftz-f1 genes in different lineages. This suggests that ftz-f1 expression changed after the divergence of lineages leading to extant beetles and flies, likely due to differences in cis-regulatory sequences. We propose that the dependence of Dm-Ftz-F1 on interaction with the homeodomain protein Ftz which is expressed in stripes in Drosophila, loosened constraints on Dm-ftz-f1 expression, allowing for ubiquitous expression of this pair-rule gene in Drosophila. © 2013 Wiley Periodicals, Inc.

Segmental transport after unreamed intramedullary nailing. Preliminary report of a "Monorail" system.

PubMed

Raschke, M J; Mann, J W; Oedekoven, G; Claudi, B F

1992-09-01

The Ilizarov method of segmental bone transport has been shown to be an alternative to more conventional treatments of posttraumatic bony defects. After extensive clinical experience with the unreamed tibial nail in open fractures up to Grade IIIb, a new monorail fixation system for callus distraction and segmental bone transport was devised. This Monorail system is composed of an unreamed intramedullary (IM) nail and a unilateral AO distraction device. The new fixation method and the preliminary clinical experience are reported here. Four patients who previously sustained Grades II-IIIb open tibial fractures had an average bony defect of 9 cm. Two patients had previous bony infections. All patients had had serial debridements and myocutaneous flaps were required in three patients. An unreamed IM nail was inserted, and the transport device was applied. After an osteotomy, segmental transport was carried out until docking was achieved. The external fixator was removed after interlocking of the transported segment. The mean duration of external fixation was 17.9 days/cm and the mean period until roentgenographic consolidation of the distraction and nonunion site was 41.2 days/cm. There were two pin-tract infections but no IM infections. One nail broke after osseous consolidation of the regenerate at the distal interlocking site and required exchange. The goal of transport was achieved in all cases without angular or rotational deformity or length discrepancy. There were no neurovascular injuries.

Multiple schwannomas of the digital nerves and superficial radial nerve: two unusual cases of segmental schwannomatosis.

PubMed

Gosk, Jerzy; Gutkowska, Olga; Kuliński, Sebastian; Urban, Maciej; Hałoń, Agnieszka

2015-01-01

Two cases of segmental sporadic schwannomatosis characterized by unusual location of multiple schwannomas in digital nerves (case 1) and the superficial radial nerve (case 2) are described in this paper. In the first of the described cases, 6 tumours located at the base of the middle finger and in its distal portion were excised from both digital nerves. In the second case, 3 tumours located in the proximal 1/3 and halfway down the forearm were removed from the superficial radial nerve. In both cases, symptoms such as palpable tumour mass, pain, paraesthesias, and positive Tinel-Hoffman sign resolved after operative treatment. Final diagnoses were made based on histopathological examination results. In the second of the described cases, the largest of the excised lesions had features enabling diagnosis of a rare tumour type - ancient schwannoma.

Wedge edge ceramic combustor tile

DOEpatents

Shaffer, J.E.; Holsapple, A.C.

1997-06-10

A multipiece combustor has a portion thereof being made of a plurality of ceramic segments. Each of the plurality of ceramic segments have an outer surface and an inner surface. Each of the plurality of ceramic segments have a generally cylindrical configuration and including a plurality of joints. The joints define joint portions, a first portion defining a surface being skewed to the outer surface and the inner surface. The joint portions have a second portion defining a surface being skewed to the outer surface and the inner surface. The joint portions further include a shoulder formed intermediate the first portion and the second portion. The joints provide a sealing interlocking joint between corresponding ones of the plurality of ceramic segments. Thus, the multipiece combustor having the plurality of ceramic segment with the plurality of joints reduces the physical size of the individual components and the degradation of the surface of the ceramic components in a tensile stress zone is generally eliminated reducing the possibility of catastrophic failures. 7 figs.

Wedge edge ceramic combustor tile

DOEpatents

Shaffer, James E.; Holsapple, Allan C.

1997-01-01

A multipiece combustor has a portion thereof being made of a plurality of ceramic segments. Each of the plurality of ceramic segments have an outer surface and an inner surface. Each of the plurality of ceramic segments have a generally cylindrical configuration and including a plurality of joints. The joints define joint portions, a first portion defining a surface being skewed to the outer surface and the inner surface. The joint portions have a second portion defining a surface being skewed to the outer surface and the inner surface. The joint portions further include a shoulder formed intermediate the first portion and the second portion. The joints provide a sealing interlocking joint between corresponding ones of the plurality of ceramic segments. Thus, the multipiece combustor having the plurality of ceramic segment with the plurality of joints reduces the physical size of the individual components and the degradation of the surface of the ceramic components in a tensile stress zone is generally eliminated reducing the possibility of catastrophic failures.

A Modular Hierarchical Approach to 3D Electron Microscopy Image Segmentation

PubMed Central

Liu, Ting; Jones, Cory; Seyedhosseini, Mojtaba; Tasdizen, Tolga

2014-01-01

The study of neural circuit reconstruction, i.e., connectomics, is a challenging problem in neuroscience. Automated and semi-automated electron microscopy (EM) image analysis can be tremendously helpful for connectomics research. In this paper, we propose a fully automatic approach for intra-section segmentation and inter-section reconstruction of neurons using EM images. A hierarchical merge tree structure is built to represent multiple region hypotheses and supervised classification techniques are used to evaluate their potentials, based on which we resolve the merge tree with consistency constraints to acquire final intra-section segmentation. Then, we use a supervised learning based linking procedure for the inter-section neuron reconstruction. Also, we develop a semi-automatic method that utilizes the intermediate outputs of our automatic algorithm and achieves intra-segmentation with minimal user intervention. The experimental results show that our automatic method can achieve close-to-human intra-segmentation accuracy and state-of-the-art inter-section reconstruction accuracy. We also show that our semi-automatic method can further improve the intra-segmentation accuracy. PMID:24491638

Testing and Calibration of Phase Plates for JWST Optical Simulator

NASA Technical Reports Server (NTRS)

Gong, Qian; Chu, Jenny; Tournois, Severine; Eichhorn, William; Kubalak, David

2011-01-01

Three phase plates were designed to simulate the JWST segmented primary mirror wavefront at three on-orbit alignment stages: coarse phasing, intermediate phasing, and fine phasing. The purpose is to verify JWST's on-orbit wavefront sensing capability. Amongst the three stages, coarse alignment is defined to have piston error between adjacent segments being 30 m to 300 m, intermediate being 0.4 m to 10 m, and fine is below 0.4 m. The phase plates were made of fused silica, and were assembled in JWST Optical Simulator (OSIM). The piston difference was realized by the thickness difference of two adjacent segments. The two important parameters to phase plates are piston and wavefront errors. Dispersed Fringe Sensor (DFS) method was used for initial coarse piston evaluation, which is the emphasis of this paper. Point Diffraction Interferometer (PDI) is used for fine piston and wavefront error. In order to remove piston's 2 pi uncertainty with PDI, three laser wavelengths, 640nm, 660nm, and 780nm, are used for the measurement. The DHS test setup, analysis algorithm and results are presented. The phase plate design concept and its application (i.e. verifying the JWST on-orbit alignment algorithm) are described. The layout of JWST OSIM and the function of phase plates in OSIM are also addressed briefly.

Use of intermediate guide catheters as an adjunct in extracranial embolization to avoid onyx reflux into the anastomotic vasculature. A technical note.

PubMed

Puri, Ajit S; Kühn, Anna L; Hou, Samuel Y; Wakhloo, Ajay K

2014-01-01

Onyx is a non-adhesive polymer used for embolization of arteriovenous malformations and dural arteriovenous fistulas (DAVFs). The limiting factor for Onyx embolization is usually the amount of microcatheter reflux, which can be safely tolerated. The dual microcatheter technique, compliant balloon use proximally and the use of the dual lumen Scepter balloon have been described to prevent and limit proximal Onyx reflux. We describe the use the Navien 058 intermediate guide catheter to accept the Onyx reflux in its lumen and possibly also serve as a mechanical barrier to avoid reflux into the anastomotic channel connecting the occipital artery to the vertebral artery during DAVF embolization via the occipital artery. Complete embolization of the DAVF was achieved using the lumen of the Navien catheter to accept aggressive Onyx reflux. Complete cure of the DAVF was obtained with Onyx cast filling the entire venous pouch. Besides providing distal access support, intermediate guide catheters can also prevent embolic material reflux by accepting reflux into the lumen and providing a mechanical barrier.

Use of Intermediate Guide Catheters as an Adjunct in Extracranial Embolization to Avoid Onyx Reflux into the Anastomotic Vasculature

PubMed Central

Puri, Ajit S; Kühn, Anna L; Hou, Samuel Y; Wakhloo, Ajay K

2014-01-01

Summary Onyx is a non-adhesive polymer used for embolization of arteriovenous malformations and dural arteriovenous fistulas (DAVFs). The limiting factor for Onyx embolization is usually the amount of microcatheter reflux, which can be safely tolerated. The dual microcatheter technique, compliant balloon use proximally and the use of the dual lumen Scepter balloon have been described to prevent and limit proximal Onyx reflux. We describe the use the Navien 058 intermediate guide catheter to accept the Onyx reflux in its lumen and possibly also serve as a mechanical barrier to avoid reflux into the anastomotic channel connecting the occipital artery to the vertebral artery during DAVF embolization via the occipital artery. Complete embolization of the DAVF was achieved using the lumen of the Navien catheter to accept aggressive Onyx reflux. Complete cure of the DAVF was obtained with Onyx cast filling the entire venous pouch. Besides providing distal access support, intermediate guide catheters can also prevent embolic material reflux by accepting reflux into the lumen and providing a mechanical barrier. PMID:25207904

Charge-Induced (1 x 3) Reconstruction of Au(110): Mechanistic Insights from Potentiodynamic Scanning Tunneling Microscopy in Alkali Iodide Electrolytes

DTIC Science & Technology

1994-02-01

In potassium iodide electrolyte, the usual "three-missing-row" (1 x 3) structure is seen to be generated by single gold atomic-row segments shifting...observed, involving the intermediate local formation of "one-missing-row" (I x 3) domains by removal of one-third of the top layer gold rows onto nearby...structure is achieved by aggregation of the displaced monoatomic row segments. The mechanistic value of following atomic-level reconstruction processes by

Differences in distal lower extremity tissue masses and mass ratios exist in athletes of sports involving repetitive impacts.

PubMed

Schinkel-Ivy, Alison; Burkhart, Timothy A; Andrews, David M

2014-01-01

This study aimed to examine the effects of sex and sport on the tissue composition of the distal lower extremity of varsity athletes, in sports that involve repetitive-impact loading patterns. Fat mass, lean mass, bone mineral content and wobbling mass were predicted for the leg and leg + foot segments of varsity basketball, cross-country, soccer and volleyball athletes. The absolute masses were normalised to body mass, and also expressed relative to each other as ratios. Females and males differed on most normalised tissue masses and ratios by 11-101%. Characteristic differences were found in the normalised tissue masses across sports, with the lowest and highest values displayed by cross-country and volleyball (female)/basketball (male) athletes, respectively. Conversely, cross-country athletes had the highest wobbling mass:bone mineral content and lean mass:bone mineral content ratios for females by 10% and 16%, respectively. The differences between sports may be explained in part by different impact loading patterns characteristic of each sport. Tissue mass ratio differences between sports may suggest that the ratios of soft to rigid tissues are optimised by the body in response to typical loading patterns, and may therefore be useful in investigations of distal lower extremity injury mechanisms in athletes.

Prevention of the collapse of pial collaterals by remote ischemic perconditioning during acute ischemic stroke.

PubMed

Ma, Junqiang; Ma, Yonglie; Dong, Bin; Bandet, Mischa V; Shuaib, Ashfaq; Winship, Ian R

2017-08-01

Collateral circulation is a key variable determining prognosis and response to recanalization therapy during acute ischemic stroke. Remote ischemic perconditioning (RIPerC) involves inducing peripheral ischemia (typically in the limbs) during stroke and may reduce perfusion deficits and brain damage due to cerebral ischemia. In this study, we directly investigated pial collateral flow augmentation due to RIPerC during distal middle cerebral artery occlusion (MCAo) in rats. Blood flow through pial collaterals between the anterior cerebral artery (ACA) and the MCA was assessed in male Sprague Dawley rats using in vivo laser speckle contrast imaging (LSCI) and two photon laser scanning microscopy (TPLSM) during distal MCAo. LSCI and TPLSM revealed that RIPerC augmented collateral flow into distal MCA segments. Notably, while control rats exhibited an initial dilation followed by a progressive narrowing of pial arterioles 60 to 150-min post-MCAo (constricting to 80-90% of post-MCAo peak diameter), this constriction was prevented or reversed by RIPerC (such that vessel diameters increased to 105-110% of post-MCAo, pre-RIPerC diameter). RIPerC significantly reduced early ischemic damage measured 6 h after stroke onset. Thus, prevention of collateral collapse via RIPerC is neuroprotective and may facilitate other protective or recanalization therapies by improving blood flow in penumbral tissue.

Segmentation and Contrasting Magma Supply Along the South-East Indian Ridge, 130°E to 140°E: Results of the STORM Cruise

NASA Astrophysics Data System (ADS)

Briais, A.; Ruellan, E.; Maia, M.; Hemond, C.; Hanan, B. B.; Ceuleneer, G.; Graham, D. W.; Park, S. H.

2017-12-01

We present observations of the South-East Indian Ridge (SEIR) between 130°E to 140°E, mostly collected during the STORM cruise (South Tasmania Ocean Ridge and Mantle) on the N/O L'Atalante. The SEIR displays large variations of axial depth despite an almost constant intermediate full spreading rate of 75 km/m.y. In the study area the analysis of multibeam bathymetry maps shows that the axis displays a rise morphology to the east away from the discontinuities, and a rifted high morphology in the west and near the OSCs, as often observed along intermediate-spreading mid-ocean ridges. The ridge axis is offset by 27 km at 131°E and 20 km at 135°E by two large-offset overlapping spreading centers (OSCs) propagating westward, and by a smaller OSC at 137°17'E. These OSCs define four second-order ridge segments (A2 to A5 from west to east). We observe a general shallowing of the ridge axis from 3100 m depth in the west to 2400 m depth in the east, and a prominent deepening of the axis near the large OSCs. The easternmost segment A5 shows a very shallow axial ridge suggesting a robust magma supply despite its proximity to the George V transform fault (140°E). Major element variations in basalt glasses are systematically related to morphotectonic segmentation of the ridge axis, showing contrasts in crystal fractionation from one segment to another that may relate to differences in replenishment of axial melt lenses by primitive melts. Along segment A5, crystallization increases with proximity to the George V transform fault, consistent with an expected cold edge effect. In contrast, along segment A3 the extent of crystallization increases progressively from east to west in the direction of ridge propagation. *STORM Cruise Scientific Party: F. Barrere, C. Boulart, A. Briais, D. Brunelli, G. Ceuleneer, N. Ferreira, D. Graham, B. Hanan, C. Hémond, S. Macleod, M. Maia, A. Maillard, S. Merkuryev, S.H. Park, S. Révillon, E. Ruellan, A. Schohn, S. Watson, and Y.S. Yang.

Untangleing the effects of chain rigidity on the structure and dynamics of strongly adsorbed polymer melts

DOE PAGES

Carrillo, Jan-Michael Y.; Cheng, Shiwang; Kumar, Rajeev; ...

2015-06-11

Here, we present a detailed analysis of coarse-grained molecular dynamics simulations of semiflexible polymer melts in contact with a strongly adsorbing substrate. We have characterized the segments in the interfacial layer by counting the number of trains, loops, tails and unadsorbed segments. For more rigid chains, a tail and an adsorbed segment (a train) dominate while loops are more prevalent in more flexible chains. The tails exhibit a non-uniformly stretched conformation akin to the polydispersed pseudobrush envisioned by Guiselin. To probe the dynamics of the segments we computed the layer z-resolved intermediate coherent collective dynamics structure factor, S(q, t, z),more » mean-square displacement of segments, and the 2nd Legendre polynomial of the time-autocorrelation of unit bond vectors, 2[n i(t,z)•n i(0,z)]>. Our results show that segmental dynamics is slower for stiffer chains and there is a strong correlation between the structure and dynamics in the interfacial layer. There is no glassy layer, and the slowing down in dynamics of stiffer chains in the adsorbed region can be attributed to the densification and the more persistent layering of segments.« less

Fluid tagging for CT colonography: effectiveness of a 2-hour iodinated oral preparation after incomplete optical colonoscopy.

PubMed

Chang, Kevin J; Rekhi, Satinder S; Anderson, Stephan W; Soto, Jorge A

2011-01-01

To evaluate the distal extent and attenuation of bowel opacification achieved after administration of a single low volume dose of oral contrast 2 hours before computed tomographic colonography (CTC) after incomplete optical colonoscopy. This retrospective study included 144 patients undergoing CTC after incomplete colonoscopy from April 2006 to July 2008 at 2 separate medical centers. Each patient received 20 to 30 mL of diatrizoate meglumine and diatrizoate sodium solution 2 hours before being scanned. The distalmost extent of opacification was: stomach/small bowel, n = 13; cecum, n = 2; ascending colon, n = 7; transverse colon, n = 19; descending colon, n = 14; sigmoid colon, n = 24; rectum, n = 65. The mean attenuation of each opacified segment was: cecum, 449 Hounsfield units (HU); ascending colon, 474 HU; transverse colon, 468 HU; descending colon, 421 HU; sigmoid colon, 391 HU; and rectum, 382 HU. In 103 (71.5%) patients, oral contrast reached the distal colon (descending colon, sigmoid colon, or rectum). The oral contrast did not reach the colon in only 13 (9.0%) patients. Oral administration of a small volume hyperosmolar oral contrast agent 2 hours before CTC results in satisfactory colonic opacification in the majority of patients. Adding same-day fluid tagging in incomplete colonoscopy patients presenting for completion CTC should result in adequate fluid opacification for most of the colon, especially proximal segments not visualized at the time of incomplete colonoscopy.

Deacetylase activity of histone deacetylase 3 is required for productive VDJ recombination and B-cell development

PubMed Central

Stengel, Kristy R.; Barnett, Kelly R.; Wang, Jing; Liu, Qi; Hodges, Emily; Hiebert, Scott W.; Bhaskara, Srividya

2017-01-01

Histone deacetylase 3 (HDAC3) is the catalytic component of NCoR/SMRT corepressor complexes that mediate the actions of transcription factors implicated in the regulation of B-cell development and function. We crossed Hdac3 conditional knockout mice with Mb1-Cre knockin animals to delete Hdac3 in early progenitor B cells. The spleens of Hdac3F/−Mb1-Cre+/− mice were virtually devoid of mature B cells, and B220+CD43+ B-cell progenitors accumulated within the bone marrow. Quantitative deep sequencing of the Ig heavy chain locus from B220+CD43+ populations identified a defect in VHDJH recombination with a severe reduction in productive rearrangements, which directly corresponded to the loss of pre-B cells from Hdac3Δ/− bone marrow. For Hdac3Δ/− B cells that did show productive VDJ rearrangement, there was significant skewing toward the incorporation of proximal VH gene segments and a corresponding reduction in distal VH gene segment use. Although transcriptional effects within these loci were modest, Hdac3Δ/− progenitor cells displayed global changes in chromatin structure that likely hindered effective distal V-DJ recombination. Reintroduction of wild-type Hdac3 restored normal B-cell development, whereas an Hdac3 point mutant lacking deacetylase activity failed to complement this defect. Thus, the deacetylase activity of Hdac3 is required for the generation of mature B cells. PMID:28739911

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

Ozkan, Ugur, E-mail: radugur@yahoo.com; Oguzkurt, Levent, E-mail: loguzkurt@yahoo.com; Tercan, Fahri, E-mail: ftercan@yahoo.com

The aim of this study was to report our experience in endovascular treatment of total aortoiliac occlusion. Five patients who underwent endovascular recanalization procedures including manual aspiration thrombectomy, balloon angioplasty, and stent placement for total aortoiliac occlusion in a 4-year period were reviewed retrospectively. The mean age of patients was 51 years (range, 43 to 58 years). All patients had abdominal aorta and bilateral common iliac artery occlusion with or without external iliac artery occlusion. All patients either had a contraindication to surgery or refused it. Initial technical success was obtained in four of five (80%) patients. Endovascular techniques weremore » successful in four patients who had good distal runoff and short-segment aortoiliac occlusion, but failed in a patient who had the worst distal runoff and long-segment aortoiliac occlusion. We observed two major complications, one of which was bilateral rupture of the common iliac arteries treated with covered stent placement. Another patient had extension of intra-aortic thrombus into the iliac stent after primary stenting. This was successfully treated with manual aspiration thrombectomy. Aortic and iliac stents remained patent during the follow-up period (median, 18 months; range, 3 to 26 months) in four patients. Primary patency rates at 6, 12, and 24 months were all 80%. In conclusion, endovascular treatment can be an alternative for aortoiliac occlusion in selected patients. Short- to midterm follow-up so far is satisfactory. Removal of intra-aortic thrombus with manual aspiration thrombectomy before balloon angioplasty and/or stenting is possible and a good alternative to thrombolysis.« less

Multi-segmental movement patterns reflect juggling complexity and skill level.

PubMed

Zago, Matteo; Pacifici, Ilaria; Lovecchio, Nicola; Galli, Manuela; Federolf, Peter Andreas; Sforza, Chiarella

2017-08-01

The juggling action of six experts and six intermediates jugglers was recorded with a motion capture system and decomposed into its fundamental components through Principal Component Analysis. The aim was to quantify trends in movement dimensionality, multi-segmental patterns and rhythmicity as a function of proficiency level and task complexity. Dimensionality was quantified in terms of Residual Variance, while the Relative Amplitude was introduced to account for individual differences in movement components. We observed that: experience-related modifications in multi-segmental actions exist, such as the progressive reduction of error-correction movements, especially in complex task condition. The systematic identification of motor patterns sensitive to the acquisition of specific experience could accelerate the learning process. Copyright © 2017 Elsevier B.V. All rights reserved.

Segmental distribution of some common molecular markers for colorectal cancer (CRC): influencing factors and potential implications.

PubMed

Papagiorgis, Petros Christakis

2016-05-01

Proximal and distal colorectal cancers (CRCs) are regarded as distinct disease entities, evolving through different genetic pathways and showing multiple clinicopathological and molecular differences. Segmental distribution of some common markers (e.g., KRAS, EGFR, Ki-67, Bcl-2, COX-2) is clinically important, potentially affecting their prognostic or predictive value. However, this distribution is influenced by a variety of factors such as the anatomical overlap of tumorigenic molecular events, associations of some markers with other clinicopathological features (stage and/or grade), and wide methodological variability in markers' assessment. All these factors represent principal influences followed by intratumoral heterogeneity and geographic variation in the frequency of detection of particular markers, whereas the role of other potential influences (e.g., pre-adjuvant treatment, interaction between markers) remains rather unclear. Better understanding and elucidation of the various influences may provide a more accurate picture of the segmental distribution of molecular markers in CRC, potentially allowing the application of a novel patient stratification for treatment, based on particular molecular profiles in combination with tumor location.

Spatial Variation of Slip Behavior Beneath the Alaska Peninsula Along Alaska-Aleutian Subduction Zone

NASA Astrophysics Data System (ADS)

Li, Shanshan; Freymueller, Jeffrey T.

2018-04-01

We resurveyed preexisting campaign Global Positioning System (GPS) sites and estimated a highly precise GPS velocity field for the Alaska Peninsula. We use the TDEFNODE software to model the slip deficit distribution using the new GPS velocities. We find systematic misfits to the vertical velocities from the optimal model that fits the horizontal velocities well, which cannot be explained by altering the slip distribution, so we use only the horizontal velocities in the study. Locations of three boundaries that mark significant along-strike change in the locking distribution are identified. The Kodiak segment is strongly locked, the Semidi segment is intermediate, the Shumagin segment is weakly locked, and the Sanak segment is dominantly creeping. We suggest that a change in preexisting plate fabric orientation on the downgoing plate has an important control on the along-strike variation in the megathrust locking distribution and subduction seismicity.

Immediate effects of a distal gait modification during stair descent in individuals with patellofemoral pain.

PubMed

Aliberti, Sandra; Mezêncio, Bruno; Amadio, Alberto Carlos; Serrão, Julio Cerca; Mochizuki, Luis

2018-05-23

Knee pain during stair managing is a common complaint among individuals with PFP and can negatively affect their activities of daily living. Gait modification programs can be used to decrease patellofemoral pain. Immediate effects of a stair descent distal gait modification session that intended to emphasize forefoot landing during stair descent are described in this study. To analyze the immediate effects of a distal gait modification session on lower extremity movements and intensity of pain in women with patellofemoral pain during stair descent. Nonrandomized controlled trial. Sixteen women with patellofemoral pain were allocated into two groups: (1) Gait Modification Group (n = 8); and 2) Control Group (n = 8). The intensity of pain (visual analog scale) and kinematics of knee, ankle, and forefoot (multi-segmental foot model) during stair descent were assessed before and after the intervention. After the gait modification session, there was an increase of forefoot eversion and ankle plantarflexion as well as a decrease of knee flexion. An immediate decrease in patellofemoral pain intensity during stair descent was also observed. The distal gait modification session changed the lower extremity kinetic chain strategy of movement, increasing foot and ankle movement contribution and decreasing knee contribution to the task. An immediate decrease in patellofemoral pain intensity during stair descent was also observed. To emphasize forefoot landing may be a useful intervention to immediately relieve pain in patients with patellofemoral pain during stair descent. Clinical studies are needed to verify the gait modification session effects in medium and long terms.

The effects of alveolar bone loss and miniscrew position on initial tooth displacement during intrusion of the maxillary anterior teeth: Finite element analysis

PubMed Central

Cho, Sun-Mi; Choi, Sung-Hwan; Sung, Sang-Jin; Yu, Hyung-Seog

2016-01-01

Objective The aim of this study was to determine the optimal loading conditions for pure intrusion of the six maxillary anterior teeth with miniscrews according to alveolar bone loss. Methods A three-dimensional finite element model was created for a segment of the six anterior teeth, and the positions of the miniscrews and hooks were varied after setting the alveolar bone loss to 0, 2, or 4 mm. Under 100 g of intrusive force, initial displacement of the individual teeth in three directions and the degree of labial tilting were measured. Results The degree of labial tilting increased with reduced alveolar bone height under the same load. When a miniscrew was inserted between the two central incisors, the amounts of medial-lateral and anterior-posterior displacement of the central incisor were significantly greater than in the other conditions. When the miniscrews were inserted distally to the canines and an intrusion force was applied distal to the lateral incisors, the degree of labial tilting and the amounts of displacement of the six anterior teeth were the lowest, and the maximum von Mises stress was distributed evenly across all the teeth, regardless of the bone loss. Conclusions Initial tooth displacement similar to pure intrusion of the six maxillary anterior teeth was induced when miniscrews were inserted distal to the maxillary canines and an intrusion force was applied distal to the lateral incisors. In this condition, the maximum von Mises stresses were relatively evenly distributed across all the teeth, regardless of the bone loss. PMID:27668194

Preserved hyperaemic response in (distal) string sign left internal mammary artery grafts.

PubMed

Hartman, Joost; Kelder, Hans; Ackerstaff, Rob; van Swieten, Henry; Vermeulen, Freddy; Bogers, Ad

2007-02-01

To correlate supraclavicular ultrasonography at rest and in hyperaemic response with angiographically patent and (distal) 'string sign' left internal mammary artery (LIMA) to left anterior descending (LAD) area grafts. Fifty-three patients with LIMA to LAD area grafting were prospectively entered in a follow-up study. Arteriography (native and LIMA) was performed at 1.4+/-0.8 years postoperatively and ultrasonography was performed at rest, in hyperaemic response and 2min after hyperaemic response at 1.8+/-0.8 years postoperatively and was compared to arteriography. Ultrasonographic parameters analysed were systolic and diastolic peak velocity, systolic and diastolic velocity integral, diastolic/systolic peak velocity ratio and diastolic/total velocity integral ratio. One patient was excluded because obesity hampered ultrasonography. Arteriography demonstrated functional grafts in 43 patients (group I), sequential distal 'string sign grafts' in 4 patients (group II) and total 'string sign grafts' in 5 patients (group III). Between the groups all ultrasonographic velocities showed a significant linear relation (p

Anti-inflammatory Efficiency of Ankaferd Blood Stopper in Experimental Distal Colitis Model

PubMed Central

Koçak, Erdem; Akbal, Erdem; Taş, Adnan; Köklü, Seyfettin; Karaca, Gökhan; Can, Murat; Kösem, Bahadır; Üstün, Hüseyin

2013-01-01

Background/Aim: Ankaferd blood stopper (ABS) is a herbal extract that enhances mucosal healing. In this study, we aimed to investigate the efficiency of ABS in the treatment of experimental distal colitis. Materials and Methods: Twenty one male albino rats were divided into three groups: Sham control (Group 1), colitis induced by acetic acid and treated with saline (Group 2), colitis induced by acetic acid and treated with ABS (Group 3). At end of the 7th day of induction, all the rats were lightly anesthetized with intramuscular ketamine (8 mg/kg) and thereafter laparotomy and total colectomy were performed. The distal colon segment was assessed macroscopically and microscopically. In addition malondialdehyde (MDA), superoxide dismutase (SOD) and nitric oxide (NO) levels of the colonic tissue and changes in body weight were measured. Results: The MDA and NO levels of the colonic tissues and weight loss were significantly higher in Group 2 compared to Group 1 and Group 3. Microscopic and macroscopic damage scores were significantly higher in Group 2 and Group 3 than Group 1 (P: 0.001, P: 0.004, respectively). Although the microscopic and macroscopic damage scores in Group 3 were slightly lower than Group 2, the difference was not statistically significant. The SOD levels of the colonic tissues were not different between the three groups. Conclusion: Weight alterations and high-levels of the colonic tissue MDA and NO suggested that ABS might have anti-inflammatory effects on experimental distal colitis. However, this suggestion was not supported by histopathological findings. PMID:23680710

A paradigm shift in the surgical reconstruction of extra-articular distal humeral fractures: single-column plating.

PubMed

Meloy, Gregory M; Mormino, Matthew A; Siska, Peter A; Tarkin, Ivan S

2013-11-01

The study aimed (1) to examine if there are equivalent results in terms of union, alignment and elbow functionally comparing single- to dual-column plating of AO/OTA 13A2 and A3 distal humeral fractures and (2) if there are more implant-related complications in patients managed with bicolumnar plating compared to single-column plate fixation. This was a multi-centred retrospective comparative study. The study was conducted at two academic level 1 trauma centres. A total of 105 patients were identified to have surgical management of extra-articular distal humeral fractures Arbeitsgemeinschaft für Osteosynthesefragen/Orthopaedic Trauma Association (AO/OTA) 13A2 and AO/OTA 13A3). Patients were treated with traditional dual-column plating or a single-column posterolateral small-fragment pre-contoured locking plate used as a neutralisation device with at least five screws in the short distal segment. The patients' elbow functionality was assessed in terms of range of motion, union and alignment. In addition, the rate of complications between the groups including radial nerve palsy, implant-related complications (painful prominence and/or ulnar nerve neuritis) and elbow stiffness were compared. Patients treated with single-column plating had similar union rates and alignment. However, single-column plating resulted in a significantly better range of motion with less complications. The current study suggests that exposure/instrumentation of only the lateral column is a reliable and preferred technique. This technique allows for comparable union rates and alignment with increased elbow functionality and decreased number of complications. Copyright © 2013 Elsevier Ltd. All rights reserved.

Mesozoic carbonate-siliciclastic platform to basin systems of a South Tethyan margin (Egypt, East Mediterranean)

NASA Astrophysics Data System (ADS)

Tassy, Aurélie; Crouzy, Emmanuel; Gorini, Christian; Rubino, Jean-Loup

2015-04-01

The Mesozoïc Egyptian margin is the south margin of a remnant of the Neo-Tethys Ocean, at the African northern plate boundary. East Mediterranean basin developed during the late Triassic-Early Jurassic rifting with a NW-SE opening direction (Frizon de Lamotte et al., 2011). During Mesozoïc, Egypt margin was a transform margin with a NW-SE orientation of transform faults. In the Eastern Mediterranean basin, Mesozoïc margins are characterized by mixed carbonate-siliciclastics platforms where subsidence and eustacy are the main parameters controlling the facies distribution and geometries of the platform-to-basin transition. Geometries and facies on the platform-slope-basin system, today well constrained on the Levant area, where still poorly known on the Egyptian margin. Geometries and stratigraphic architecture of the Egyptian margin are revealed, thanks to a regional seismic and well data-base provided by an industrial-academic group (GRI, Total). The objective is to understand the sismostratigraphic architecture of the platform-slope-basin system in a key area from Western Desert to Nile delta and Levant margin. Mapping of the top Jurassic and top Cretaceous show seismic geomorphology of the margin, with the cartography of the hinge line from Western Desert to Sinaï. During the Jurassic, carbonate platform show a prograding profile and a distally thickening of the external platform, non-abrupt slope profiles, and palaeovalleys incisions. Since the Cretaceous, the aggrading and retrograding mixed carbonate-siliciclastic platform show an alternation of steep NW-SE oblique segments and distally steepened segments. These structures of the platform edge are strongly controlled by the inherited tethyan transform directions. Along the hinge line, embayments are interpreted as megaslides. The basin infilling is characterised by an alternation of chaotic seismic facies and high amplitude reflectors onlaping the paleoslopes. MTC deposits can mobilize thick sedimentary series (up to 3500 m) as a mixed combination of debris flows, internal preserved blocks, and/or compressively-deformed distal allochthonous masses. Transported material have proceeded from the dismantling of the Mesozoic mixed carbonate-siliciclastic platform. They can spread down slope over areas as large as 70000 of km2. According to stratigraphic correlations with global sea-level positions, platform instability would have been triggered by the gravitational collapse of the carbonate-siliciclastic platform under its own weight after successive subaerial exposures which were able to generate karstification processes. Seismic interpretation is constrained by a detailed assessment of the Egyptian margin paleogeography supported by wells. This margin segment is briefly compared to the outcropping Apulian margin in Italy.

Semiautomatic tumor segmentation with multimodal images in a conditional random field framework.

PubMed

Hu, Yu-Chi; Grossberg, Michael; Mageras, Gikas

2016-04-01

Volumetric medical images of a single subject can be acquired using different imaging modalities, such as computed tomography, magnetic resonance imaging (MRI), and positron emission tomography. In this work, we present a semiautomatic segmentation algorithm that can leverage the synergies between different image modalities while integrating interactive human guidance. The algorithm provides a statistical segmentation framework partly automating the segmentation task while still maintaining critical human oversight. The statistical models presented are trained interactively using simple brush strokes to indicate tumor and nontumor tissues and using intermediate results within a patient's image study. To accomplish the segmentation, we construct the energy function in the conditional random field (CRF) framework. For each slice, the energy function is set using the estimated probabilities from both user brush stroke data and prior approved segmented slices within a patient study. The progressive segmentation is obtained using a graph-cut-based minimization. Although no similar semiautomated algorithm is currently available, we evaluated our method with an MRI data set from Medical Image Computing and Computer Assisted Intervention Society multimodal brain segmentation challenge (BRATS 2012 and 2013) against a similar fully automatic method based on CRF and a semiautomatic method based on grow-cut, and our method shows superior performance.

Homeologous Recombination in Solanum lycopersicoides Introgression Lines of Cultivated Tomato

PubMed Central

Canady, Michael A.; Ji, Yuanfu; Chetelat, Roger T.

2006-01-01

A library of “introgression lines” containing Solanum lycopersicoides chromosome segments in the genetic background of cultivated tomato (Lycopersicon esculentum) was used to study factors affecting homeologous recombination. Recombination rates were estimated in progeny of 43 heterozygous introgressions and whole-chromosome substitution lines, together representing 11 of the 12 tomato chromosomes. Recombination within homeologous segments was reduced to as little as 0–10% of expected frequencies. Relative recombination rates were positively correlated with the length of introgressed segments on the tomato map. The highest recombination (up to 40–50% of normal) was observed in long introgressions or substitution lines. Double-introgression lines containing two homeologous segments on opposite chromosome arms were synthesized to increase their combined length. Recombination was higher in the double than in the single segment lines, despite a preference for crossovers in the region of homology between segments. A greater increase in homeologous recombination was obtained by crossing the S. lycopersicoides introgression lines to L. pennellii—a phylogenetically intermediate species—or to L. esculentum lines containing single L. pennellii segments on the same chromosome. Recombination rates were highest in regions of overlap between S. lycopersicoides and L. pennellii segments. The potential application of these results to breeding with introgression lines is discussed. PMID:17057228

Reconstitution of the R compound allele in maize.

PubMed

Dooner, H K; Kermicle, J L

1974-10-01

The R(r):standard allele in maize, which conditions anthocyanin pigmentation in plant and seed tissues in the presence of appropriate complementary factors, is associated with a tandem duplication. The proximal member of the duplication carries P, the plant pigmenting determiner and the distal member member carries S, the seed pigmenting determiner. Derivatives from R(r) that have lost S function are designated r(r). They represent either losses of the distal member of the duplication (P derivatives) or mutations of S to s (P s). Derivatives that have lost P function are designated R(g), and represent either losses of the proximal member of the duplication (S derivatives) or mutations of P to p (p S).-All four possible types of r(r)/R(g) heterozygotes were tested for their capacity to yield R(r) reconstitution by crossing over. No R(r) derivatives were obtained from P/S heterozygotes, a result consistent with the view that P and S occupy corresponding positions in homologous chromosome segments. R(r) reconstitution was detected in both tandem duplication heterozygotes P s/S and P/p S, and was found to be about ten times more frequent in the latter. The ratio of R(r) reconstitution in the two heterozygotes is a function of position of the anthocyanin marker within the duplicated segment. The data from these heterozygotes allow one to measure the distance between P and S, that is to say, the genetic length of the duplicated segment. This distance was found to be 0.16 map units. The highest frequency of R(r) reconstitution was obtained from P s/p S heterozygotes, since direct pairing (see PDF) as well as the p//s type of displaced pairing have the potential to produce R(r) derivatives. One of the R(g) derivatives used in this study, R(g) (6), was found to back-mutate in some sublines to R(r). The basis for this instability remains unknown.

Signaling by Kit protein-tyrosine kinase--the stem cell factor receptor.

PubMed

Roskoski, Robert

2005-11-11

Signaling by stem cell factor and Kit, its receptor, plays important roles in gametogenesis, hematopoiesis, mast cell development and function, and melanogenesis. Moreover, human and mouse embryonic stem cells express Kit transcripts. Stem cell factor exists as both a soluble and a membrane-bound glycoprotein while Kit is a receptor protein-tyrosine kinase. The complete absence of stem cell factor or Kit is lethal. Deficiencies of either produce defects in red and white blood cell production, hypopigmentation, and sterility. Gain-of-function mutations of Kit are associated with several human neoplasms including acute myelogenous leukemia, gastrointestinal stromal tumors, and mastocytomas. Kit consists of an extracellular domain, a transmembrane segment, a juxtamembrane segment, and a protein kinase domain that contains an insert of about 80 amino acid residues. Binding of stem cell factor to Kit results in receptor dimerization and activation of protein kinase activity. The activated receptor becomes autophosphorylated at tyrosine residues that serve as docking sites for signal transduction molecules containing SH2 domains. The adaptor protein APS, Src family kinases, and Shp2 tyrosyl phosphatase bind to phosphotyrosine 568. Shp1 tyrosyl phosphatase and the adaptor protein Shc bind to phosphotyrosine 570. C-terminal Src kinase homologous kinase and the adaptor Shc bind to both phosphotyrosines 568 and 570. These residues occur in the juxtamembrane segment of Kit. Three residues in the kinase insert domain are phosphorylated and attract the adaptor protein Grb2 (Tyr703), phosphatidylinositol 3-kinase (Tyr721), and phospholipase Cgamma (Tyr730). Phosphotyrosine 900 in the distal kinase domain binds phosphatidylinositol 3-kinase which in turn binds the adaptor protein Crk. Phosphotyrosine 936, also in the distal kinase domain, binds the adaptor proteins APS, Grb2, and Grb7. Kit has the potential to participate in multiple signal transduction pathways as a result of interaction with several enzymes and adaptor proteins.

Detection of Crohn disease lesions of the small and large bowel in pediatric patients: diagnostic value of MR enterography versus reference examinations.

PubMed

Maccioni, Francesca; Al Ansari, Najwa; Mazzamurro, Fabrizio; Civitelli, Fortunata; Viola, Franca; Cucchiara, Salvatore; Catalano, Carlo

2014-11-01

The purpose of this article is to prospectively determine the accuracy of MR enterography in detecting Crohn disease lesions from the jejunum to the anorectal region in pediatric patients, in comparison with main reference investigations. Fifty consecutive children with known Crohn disease underwent MR enterography with oral contrast agent and gadolinium-chelate intravenous injection. Two radiologists detected and localized lesions by dividing the bowel into nine segments (450 analyzed segments in 50 patients). Ileocolonoscopy, barium studies, intestinal ultrasound, and capsule endoscopy were considered as first- and second-level reference examinations and were performed within 15 days of MR enterography. MR enterography detected lesions in 164 of 450 segments, with 155 true-positive and nine false-positive findings; overall sensitivity, specificity, and positive and negative predictive values for small- and large-bowel lesions were 94.5%, 97%, 94.5%, and 97%, respectively (ĸ = 0.93; 95% CI, 0.89-0.97). Sensitivity and specificity values were 88% and 97%, respectively, for the jejunum, 100% and 97% for the proximal-to-mid ileum, 100% and 100% for the distal ileum, 93% and 100% for the cecum, 70% and 97% for the ascending colon, 80% and 100% for the transverse colon, 100% and 92% for the descending colon, 96% and 90% for the sigmoid colon, and 96% and 88% for the rectum. From jejunum to rectum, the AUC value ranged between 0.916 (jejunum) and 1.00 (distal ileum). Perianal fistulas were diagnosed in 15 patients, and other complications were found in 13 patients. MR enterography showed an accuracy comparable to that of reference investigations, for both small- and large-bowel lesions. Because MR enterography is safer and more comprehensive than the reference examinations, it should be considered the primary examination for detecting Crohn disease lesions in children.

Comparison of 3% sorbitol vs psyllium fibre as oral contrast agents in MR enterography

PubMed Central

Saini, S; Colak, E; Anthwal, S; Vlachou, P A; Raikhlin, A

2014-01-01

Objective: To compare the degree of small bowel distension achieved by 3% sorbitol, a high osmolarity solution, and a psyllium-based bulk fibre as oral contrast agents (OCAs) in MR enterography (MRE). Methods: This retrospective study was approved by our institutional review board. A total of 45 consecutive normal MRE examinations (sorbitol, n = 20; psyllium, n = 25) were reviewed. The patients received either 1.5 l of 3% sorbitol or 2 l of 1.6 g kg−1 psyllium prior to imaging. Quantitative small bowel distension measurements were taken in five segments: proximal jejunum, distal jejunum, proximal ileum, distal ileum and terminal ileum by two independent radiologists. Distension in these five segments was also qualitatively graded from 0 (very poor) to 4 (excellent) by two additional independent radiologists. Statistical analysis comparing the groups and assessing agreement included intraclass coefficients, Student's t-test and Mann–Whitney U-test. Results: Small bowel distension was not significantly different in any of the five small bowel segments between the use of sorbitol and psyllium as OCAs in both the qualitative (p = 0.338–0.908) and quantitative assessments (p = 0.083–0.856). The mean bowel distension achieved was 20.1 ± 2.2 mm for sorbitol and 19.8 ± 2.5 mm for psyllium (p = 0.722). Visualization of the ileum was good or excellent in 65% of the examinations in both groups. Conclusion: Sorbitol and psyllium are not significantly different at distending the small bowel and both may be used as OCAs for MRE studies. Advances in knowledge: This is the first study to directly compare the degree of distension in MRE between these two common, readily available and inexpensive OCAs. PMID:25062448

Effect of dietary fat on the distribution of mucosal mass and cell proliferation along the small intestine.

PubMed Central

Jenkins, A P; Thompson, R P

1992-01-01

This study investigated how substitution of long chain triglycerides for glucose in a mixed diet affects the overall small intestinal mucosal mass and the distribution of mucosal mass and cell proliferation along the small intestine. Four groups of eight female Wistar rats (180-200 g) were isocalorically fed mixed diets containing the essential fatty acid rich oil Efamol substituted for glucose at concentrations of 1.2%, 10%, 25%, and 50% total calories for 20 to 23 days. The small intestine was divided into three equal length segments and whole gut weights, mucosal weights, protein and DNA determined. Cell proliferation was estimated from the two hour accumulation of vincristine arrested metaphases in microdissected crypts at points 0%, 17%, 33%, 50%, 66%, and 100% small intestinal length. There were no differences between groups in parameters of overall small intestinal or distal segment mucosal mass. With increasing levels of fat, however, there was a significant trend for the mucosal mass of the proximal segment to fall and that of the middle segment to rise. The pattern of two hour metaphase accumulation reflected these changes. These regional changes in mucosal mass and cell proliferation may reflect differences in the sites of absorption of fat and glucose. PMID:1541418

Effect of dietary fat on the distribution of mucosal mass and cell proliferation along the small intestine.

PubMed

Jenkins, A P; Thompson, R P

1992-02-01

This study investigated how substitution of long chain triglycerides for glucose in a mixed diet affects the overall small intestinal mucosal mass and the distribution of mucosal mass and cell proliferation along the small intestine. Four groups of eight female Wistar rats (180-200 g) were isocalorically fed mixed diets containing the essential fatty acid rich oil Efamol substituted for glucose at concentrations of 1.2%, 10%, 25%, and 50% total calories for 20 to 23 days. The small intestine was divided into three equal length segments and whole gut weights, mucosal weights, protein and DNA determined. Cell proliferation was estimated from the two hour accumulation of vincristine arrested metaphases in microdissected crypts at points 0%, 17%, 33%, 50%, 66%, and 100% small intestinal length. There were no differences between groups in parameters of overall small intestinal or distal segment mucosal mass. With increasing levels of fat, however, there was a significant trend for the mucosal mass of the proximal segment to fall and that of the middle segment to rise. The pattern of two hour metaphase accumulation reflected these changes. These regional changes in mucosal mass and cell proliferation may reflect differences in the sites of absorption of fat and glucose.

English Works!

ERIC Educational Resources Information Center

Rubin, Joan; And Others

This set of materials include an interactive videotape and textbook program (tape not included here) for high-beginning and intermediate English-as-a-Second-Language (ESL) students in or about to enter the workplace. The materials provide instruction in communication skills essential for job success. The 10 video segments and corresponding student…

Analysis of 1,338 Patients with Acute Lower Limb Deep Venous Thrombosis (DVT) Supports the Inadequacy of the Term "Proximal DVT".

PubMed

De Maeseneer, M G R; Bochanen, N; van Rooijen, G; Neglén, P

2016-03-01

For decades acute lower limb deep venous thrombosis (DVT) has been subdivided into distal DVT (isolated to the calf veins) and proximal DVT (extending above calf vein level). The aim of this study was to analyse the anatomical site and extent of thrombus in a large cohort of patients with acute DVT. A retrospective analysis of all patients aged >18 years, presenting with unilateral DVT according to duplex ultrasound investigation was performed at the University Hospital of Antwerp, Belgium (1994-2012). The anatomical site and extent of thrombus was registered and subdivided into five segments: calf veins (segment 1), popliteal vein (segment 2), femoral vein (segment 3), common femoral vein (segment 4), and iliac veins, with or without inferior vena cava (segment 5). The median age of the 1,338 patients (50% male) included was 62 years (range 18-98 years). Left sided DVT was predominant (57%). DVT was limited to one segment in 443 patients, of whom 370 had DVT isolated to the calf veins (28% of total cohort). In 968 patients with what was previously called "proximal DVT", the median number of affected segments was three (range 1-5 segments). In this group iliofemoral DVT (at least involving segment four and/or five) was present in 506 patients (38% of total cohort), whereas the remaining patients had femoropopliteal DVT (at least in segment two and/or three but not in four or five). Iliofemoral DVT without thrombus in segments one and two was present in 160 patients (12% of total cohort). This study illustrates the large diversity of thrombus distribution in patients previously described as having "proximal DVT". Therefore, this term should be abandoned and replaced with iliofemoral and femoropopliteal DVT. Patients with iliofemoral DVT (38%) could be considered for early clot removal; 12% of all patients with DVT would be ideal candidates for such intervention. Copyright © 2015 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.

The error analysis of Lobular and segmental division of right liver by volume measurement.

PubMed

Zhang, Jianfei; Lin, Weigang; Chi, Yanyan; Zheng, Nan; Xu, Qiang; Zhang, Guowei; Yu, Shengbo; Li, Chan; Wang, Bin; Sui, Hongjin

2017-07-01

The aim of this study is to explore the inconsistencies between right liver volume as measured by imaging and the actual anatomical appearance of the right lobe. Five healthy donated livers were studied. The liver slices were obtained with hepatic segments multicolor-infused through the portal vein. In the slices, the lobes were divided by two methods: radiological landmarks and real anatomical boundaries. The areas of the right anterior lobe (RAL) and right posterior lobe (RPL) on each slice were measured using Photoshop CS5 and AutoCAD, and the volumes of the two lobes were calculated. There was no statistically significant difference between the volumes of the RAL or RPL as measured by the radiological landmarks (RL) and anatomical boundaries (AB) methods. However, the curves of the square error value of the RAL and RPL measured using CT showed that the three lowest points were at the cranial, intermediate, and caudal levels. The U- or V-shaped curves of the square error rate of the RAL and RPL revealed that the lowest value is at the intermediate level and the highest at the cranial and caudal levels. On CT images, less accurate landmarks were used to divide the RAL and RPL at the cranial and caudal layers. The measured volumes of hepatic segments VIII and VI would be less than their true values, and the measured volumes of hepatic segments VII and V would be greater than their true values, according to radiological landmarks. Clin. Anat. 30:585-590, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Calretinin immunoreactivity in the claustrum of the rat

PubMed Central

Druga, Rastislav; Salaj, Martin; Barinka, Filip; Edelstein, Lawrence; Kubová, Hana

2015-01-01

The claustrum is a telencephalic structure which consists of dorsal segment adjoining the insular cortex and a ventral segment termed also endopiriform nucleus (END). The dorsal segment (claustrum) is divided into a dorsal and ventral zone, while the END is parcellated into dorsal, ventral and intermediate END. The claustrum and the END consist of glutamatergic projection neurons and GABAergic local interneurons coexpressing calcium binding proteins. Among neurons expressing calcium binding proteins the calretinin (CR)-immunoreactive interneurons exert specific functions in neuronal circuits, including disinhibition of excitatory neurons. Previous anatomical data indicate extensive and reciprocally organized claustral projections with cerebral cortex. We asked if the distribution of cells immunoreactive for CR delineates anatomical or functional subdivisions in the claustrum and in the END. Both segments of the claustrum and all subdivisions of the END contained CR immunoreactive neurons with varying distribution. The ventral zone of the claustrum exhibited weak labeling with isolated cell bodies and thin fibers and is devoid of immunoreactive puncta. Within the medial margin of the intermediate END we noted a group of strongly positive neurons. Cells immunoreactive for CR in all subdivisions of the claustrum and END were bipolar, multipolar and oval with smooth, beaded aspiny dendrites. Small number of CR-immunoreactive neurons displayed thin dendrites which enter to adjoining structures. Penetration of dendrites was reciprocal. These results show an inhomogenity over the claustrum and the END in distribution and types of CR immunoreactive neurons. The distribution of the CR-immunoreactive neurons respects the anatomical but not functional zones of the claustral complex. PMID:25653596

Morphometrics and inertial properties in the body segments of chimpanzees (Pan troglodytes)

PubMed Central

Schoonaert, Kirsten; D’Août, Kristiaan; Aerts, Peter

2007-01-01

Inertial characteristics and dimensions of the body and body segments form an integral part of a biomechanical analysis of motion. In primate studies, however, segment inertial parameters of non-human hominoids are scarce and often obtained using varying techniques. Therefore, the principal aim of this study was to expand the existing chimpanzee inertial property data set using a non-invasive measuring technique. We also considered age- and sex-related differences within our sample. By means of a geometric model based on Crompton et al. (1996); Am J Phys Anthropol 99, 547–570) we generated inertial properties using external segment length and diameter measurements of 53 anaesthetized chimpanzees (Pan troglodytes). We report absolute inertial parameters for immature and mature subjects and for males and females separately. Proportional data were computed to allow the comparison between age classes and sex classes. In addition, we calculated whole limb inertial properties and we discuss their potential biomechanical consequences. We found no significant differences between the age classes in the proportional data except for hand and foot measures where juveniles exhibit relatively longer and heavier distal segments than adults. Furthermore, most sex-related differences can be directly attributed to the higher absolute segment masses in male chimpanzees resulting in higher moments of inertia. Additionally, males tend to have longer upper limbs than females. However, regarding proportional data we discuss the general inertial properties of the chimpanzee. The described segment inertial parameters of males and females, and of the two age classes, represent a valuable data set ready for use in a range of biomechanical locomotor models. These models offer great potential for improving our understanding of early hominin locomotor patterns. PMID:17451529

Segmental and age differences in the elastin network, collagen, and smooth muscle phenotype in the tunica media of the porcine aorta.

PubMed

Tonar, Zbyněk; Kubíková, Tereza; Prior, Claudia; Demjén, Erna; Liška, Václav; Králíčková, Milena; Witter, Kirsti

2015-09-01

The porcine aorta is often used in studies on morphology, pathology, transplantation surgery, vascular and endovascular surgery, and biomechanics of the large arteries. Using quantitative histology and stereology, we estimated the area fraction of elastin, collagen, alpha-smooth muscle actin, vimentin, and desmin within the tunica media in 123 tissue samples collected from five segments (thoracic ascending aorta; aortic arch; thoracic descending aorta; suprarenal abdominal aorta; and infrarenal abdominal aorta) of porcine aortae from growing domestic pigs (n=25), ranging in age from 0 to 230 days. The descending thoracic aorta had the greatest elastin fraction, which decreased proximally toward the aortic arch as well as distally toward the abdominal aorta. Abdominal aortic segments had the highest fraction of actin, desmin, and vimentin positivity and all of these vascular smooth muscle markers were lower in the thoracic aortic segments. No quantitative differences were found when comparing the suprarenal abdominal segments with the infrarenal abdominal segments. The area fraction of actin within the media was comparable in all age groups and it was proportional to the postnatal growth. Thicker aortic segments had more elastin and collagen with fewer contractile cells. The collagen fraction decreased from ascending aorta and aortic arch toward the descending aorta. By revealing the variability of the quantitative composition of the porcine aorta, the results are suitable for planning experiments with the porcine aorta as a model, i.e. power test analyses and estimating the number of samples necessary to achieving a desirable level of precision. The complete primary morphometric data, in the form of continuous variables, are made publicly available for biomechanical modeling of site-dependent distensibility and compliance of the porcine aorta. Copyright © 2015 Elsevier GmbH. All rights reserved.

Dynamic Parameter Identification of Subject-Specific Body Segment Parameters Using Robotics Formalism: Case Study Head Complex.

PubMed

Díaz-Rodríguez, Miguel; Valera, Angel; Page, Alvaro; Besa, Antonio; Mata, Vicente

2016-05-01

Accurate knowledge of body segment inertia parameters (BSIP) improves the assessment of dynamic analysis based on biomechanical models, which is of paramount importance in fields such as sport activities or impact crash test. Early approaches for BSIP identification rely on the experiments conducted on cadavers or through imaging techniques conducted on living subjects. Recent approaches for BSIP identification rely on inverse dynamic modeling. However, most of the approaches are focused on the entire body, and verification of BSIP for dynamic analysis for distal segment or chain of segments, which has proven to be of significant importance in impact test studies, is rarely established. Previous studies have suggested that BSIP should be obtained by using subject-specific identification techniques. To this end, our paper develops a novel approach for estimating subject-specific BSIP based on static and dynamics identification models (SIM, DIM). We test the validity of SIM and DIM by comparing the results using parameters obtained from a regression model proposed by De Leva (1996, "Adjustments to Zatsiorsky-Seluyanov's Segment Inertia Parameters," J. Biomech., 29(9), pp. 1223-1230). Both SIM and DIM are developed considering robotics formalism. First, the static model allows the mass and center of gravity (COG) to be estimated. Second, the results from the static model are included in the dynamics equation allowing us to estimate the moment of inertia (MOI). As a case study, we applied the approach to evaluate the dynamics modeling of the head complex. Findings provide some insight into the validity not only of the proposed method but also of the application proposed by De Leva (1996, "Adjustments to Zatsiorsky-Seluyanov's Segment Inertia Parameters," J. Biomech., 29(9), pp. 1223-1230) for dynamic modeling of body segments.

Distribution and heterogeneity of immunoreactive cholecystokinin (CCK) in the mucosa of the porcine gastrointestinal tract.

PubMed

Bacarese-Hamilton, A J; Adrian, T E; Bloom, S R

1984-11-01

The concentration and molecular nature of cholecystokinin-like immunoreactivity (CCK-LI) in extracts of porcine intestinal mucosa were determined using sequence-specific radioimmunoassays. Highest CCK concentrations were measured in duodenal mucosa (258 +/- 60 pmol/g in the distal duodenum) followed by jejunal mucosa (204 +/- 36 pmol/g in the proximal jejunum) and pylorus (51 +/- 9 pmol/g). All other gastrointestinal regions proximal to the pylorus and distal to the jejunum contained less than 20 pmol/g. Pancreas contained less than 1 pmol/g. Gel chromatography in 6 M urea revealed four immunoreactive forms and this was confirmed by reverse-phase high-pressure liquid chromatography (HPLC). The predominant molecular form in acid extracts of duodenal mucosa resembled CCK-33 although high concentrations of the larger CCK form ('CCK-58') and of the form intermediate in size between CCK-33 and CCK-8 were measured. A molecular form resembling CCK-8 was the principal form in neutral extracts of the duodenum.

Prevalence and Distribution of Atherosclerosis in a Low- to Intermediate-Risk Population: Assessment with Whole-Body MR Angiography

PubMed Central

Lambert, Matthew A.; Weir-McCall, Jonathan R.; Gandy, Stephen J.; Levin, Daniel; Cavin, Ian; Littleford, Roberta; MacFarlane, Jennifer A.; Matthew, Shona Z.; Nicholas, Richard S.; Struthers, Allan D.; Sullivan, Frank; Henderson, Shelley A.; White, Richard D.; Belch, Jill J. F.

2018-01-01

Purpose To quantify the burden and distribution of asymptomatic atherosclerosis in a population with a low to intermediate risk of cardiovascular disease. Materials and Methods Between June 2008 and February 2013, 1528 participants with 10-year risk of cardiovascular disease less than 20% were prospectively enrolled. They underwent whole-body magnetic resonance (MR) angiography at 3.0 T by using a two-injection, four-station acquisition technique. Thirty-one arterial segments were scored according to maximum stenosis. Scores were summed and normalized for the number of assessable arterial segments to provide a standardized atheroma score (SAS). Multiple linear regression was performed to assess effects of risk factors on atheroma burden. Results A total of 1513 participants (577 [37.9%] men; median age, 53.5 years; range, 40–83 years) completed the study protocol. Among 46 903 potentially analyzable segments, 46 601 (99.4%) were interpretable. Among these, 2468 segments (5%) demonstrated stenoses, of which 1649 (3.5%) showed stenosis less than 50% and 484 (1.0%) showed stenosis greater than or equal to 50%. Vascular stenoses were distributed throughout the body with no localized distribution. Seven hundred forty-seven (49.4%) participants had at least one stenotic vessel, and 408 (27.0%) participants had multiple stenotic vessels. At multivariable linear regression, SAS correlated with age (B = 3.4; 95% confidence interval: 2.61, 4.20), heart rate (B = 1.23; 95% confidence interval: 0.51, 1.95), systolic blood pressure (B = 0.02; 95% confidence interval: 0.01, 0.03), smoking status (B = 0.79; 95% confidence interval: 0.44, 1.15), and socioeconomic status (B = −0.06; 95% confidence interval: −0.10, −0.02) (P < .01 for all). Conclusion Whole-body MR angiography identifies early vascular disease at a population level. Although disease prevalence is low on a per-vessel level, vascular disease is common on a per-participant level, even in this low- to intermediate-risk cohort. © RSNA, 2018 Online supplemental material is available for this article. PMID:29714681

[Environmental health: the evolution of Colombia's current regulatory framework].

PubMed

García-Ubaque, Cesar A; García-Ubaque, Juan C; Vaca-Bohórquez, Martha L

2013-01-01

This essay presents an analysis of the evolution of environmental health management in Colombia, covering the period from the introduction of the Colombian Healthcare Code (1979) to laws 99 and 100 in 1993 and the introduction of Environmental Health Policy in Bogotá DC (2011). It proposes a conceptual model for environmental health management at three levels: proximal (physical, chemical and biological setting), intermediate (natural and cultural environment) and distal (economic, political and social structures). Relevant aspects of environmental health policy in Bogotá are analysed based on the proposed model.

Wasatch fault zone, Utah - segmentation and history of Holocene earthquakes

USGS Publications Warehouse

Machette, Michael N.; Personius, Stephen F.; Nelson, Alan R.; Schwartz, David P.; Lund, William R.

1991-01-01

The Wasatch fault zone (WFZ) forms the eastern boundary of the Basin and Range province and is the longest continuous, active normal fault (343 km) in the United States. It underlies an urban corridor of 1.6 million people (80% of Utah's population) representing the largest earthquake risk in the interior of the western United States. The authors have used paleoseismological data to identify 10 discrete segments of the WFZ. Five are active, medial segments with Holocene slip rates of 1-2 mm a-1, recurrence intervals of 2000-4000 years and average lengths of about 50 km. Five are less active, distal segments with mostly pre-Holocene surface ruptures, late Quaternary slip rates of <0.5 mm a-1, recurrence intervals of ???10,000 years and average lengths of about 20 km. Surface-faulting events on each of the medial segments of the WFZ formed 2-4-m-high scarps repeatedly during the Holocene. Paleoseismological records for the past 6000 years indicate that a major surface-rupturing earthquake has occurred along one of the medial segments about every 395 ?? 60 years. However, between about 400 and 1500 years ago, the WFZ experienced six major surface-rupturing events, an average of one event every 220 years, or about twice as often as expected from the 6000-year record. Evidence has been found that surface-rupturing events occurred on the WFZ during the past 400 years, a time period which is twice the average intracluster recurrence interval and equal to the average Holocene recurrence interval.

Primary Self-Expandable Nitinol Stent Placement in Focal Lesions of Infrarenal Abdominal Aorta: Long Term Results

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

Lastovickova, Jarmila, E-mail: jala@medicon.cz; Peregrin, Jan H.

Purpose. To evaluate the technical and clinical success, safety and long term results of percutaneous transluminal angioplasty/self-expandable nitinol stent placement of infrarenal abdominal aorta focal lesions. Materials and Methods. Eighteen patients underwent PTA of focal atherosclerotic occlusive disease of distal abdominal aorta. Two symptomatic occlusions and 16 stenoses in 10 male and 8 female patients (mean age 68.2 years) were treated with primary self-expandable nitinol stent placement. Results. Primary self-expandable nitinol stent placement was technically successful in all 18 procedures; clinical success was achieved in 100% of patients. No complications associated with the procedure occurred. During the 49.4 months ofmore » mean follow up (range 3-96, 4 months) all treated aortic segments remained patent. Conclusions. Endovascular treatment (primary self-expandable nitinol stent placement) of focal atherosclerotic lesions of distal abdominal aorta is a safe method with excellent primary technical and clinical success rates and favourable Long term results.« less

Intestinal atresia and ectopia in a bovine fetus.

PubMed

Lejeune, B; Miclard, J; Stoffel, M H; Meylan, M

2011-07-01

A 2-year-old Red Holstein cow was presented with uterine torsion at 235 days of pregnancy. The fetus extracted by cesarean section had weak vital signs and marked abdominal distention. An edematous pouch that contained tubular structures with peristaltic activity was associated with the umbilical cord. Because of poor prognosis, both dam and fetus were euthanized. At necropsy, the fetus had severe distention of the forestomachs, abomasum, and proximal small intestine; absence of distal small intestine, cecum, and proximal colon; atresia of the 2 blind ends of the intestine; and atrophy of distal colon and rectum. The tubular structures associated with the umbilical cord were identified as the segments of intestine that were absent in the fetus. Intestinal atresia combined with ectopia may be caused by local ischemia during temporary herniation and rotation of the fetal gut into the extraembryonic coelom. The close connection between ectopic intestine and amniotic sheath of the umbilical cord in this case may have facilitated vascularization and allowed development and viability of the ectopic intestine. © The Authors 2011

Partial monosomy and partial trisomy for different segments of chromosome 13 in several individuals of the same family.

PubMed

Wilroy, R S; Summitt, R L; Martens, P; Gooch, W M

1977-12-01

A reciprocal translocation, 46,XX,rcp(13;17)(q13;p13), was found to be segregating in a family. Two children have duplication of the distal portion of the long arm of chromosome 13, 46,XX,der(17),rcp(13;17)(q13;p13)mat. They are mentally retarded, have long philtra and postaxial hexadactyly. A maternal half-uncle has a duplication of the short arm and proximal portion of the long arm of chromosome 13, 47,XY,+der(13),rcp (13;17)(q13;p13)mat. He is mentally retarded, has scalp and skull defects and a very short philtrum. A fetus was found, on analysis of amniotic fluid cells, to have a deletion of the distal portion of the long arm of chromosome 13, 46,XX,der,(13),rcp(13;17)(q13;p13)mat. The fetus had multiple internal abnormalities and only 4 fingers on each hand.

A new genus of Asterocheridae (Copepoda: Siphonostomatoida) ectoassociate of the ascidian Eudistoma vannamei Millar, 1977 (Polycitoridae) from Brazil.

PubMed

Johnsson, Rodrigo; Bahia, Cristiano; Neves, Elizabeth

2016-05-23

Asterocheres Boeck, 1860 is the largest genus of the siphonostomatoid copepod family Asterocheridae, containing 63 valid species. The genus is known for its symbiotic relationships with many marine invertebrate taxa, especially sponges, cnidarians, bryozoans, and echinoderms. Recent studies have restricted the diagnosis of this genus. Consequently, many species are now considered as species inquirendae. The present paper describes a new species living externally on the tunic of Eudistoma vannamei Millar, 1977, an endemic ascidian from Brazil. As the new species does not fit Asterocheres in the strict sense, a new genus is erected to accommodate it. Setacheres gen. nov. is characterized by its possession of two distal setae on the third endopodal segment of P3, thus differing from the distal seta and spine pattern that is deemed as diagnostic of Asterocheres. A revision and comparison of Asterocheres´ species inquirendae revealed eight species sharing the same generic characteristics and were thus reallocated as members of the new genus.

Cerebral collaterals and collateral therapeutics for acute ischemic stroke.

PubMed

Winship, Ian R

2015-04-01

Cerebral collaterals are vascular redundancies in the cerebral circulation that can partially maintain blood flow to ischemic tissue when primary conduits are blocked. After occlusion of a cerebral artery, anastomoses connecting the distal segments of the MCA with distal branches of the ACA and PCA (known as leptomeningeal or pial collaterals) allow for partially maintained blood flow in the ischemic penumbra and delay or prevent cell death. However, collateral circulation varies dramatically between individuals, and collateral extent is significant predictor of stroke severity and recanalization rate. Collateral therapeutics attempt to harness these vascular redundancies by enhancing blood flow through pial collaterals to reduce ischemia and brain damage after cerebral arterial occlusion. While therapies to enhance collateral flow remain relatively nascent neuroprotective strategies, experimental therapies including inhaled NO, transient suprarenal aortic occlusion, and electrical stimulation of the parasympathetic sphenopalatine ganglion show promise as collateral therapeutics with the potential to improve treatment of acute ischemic stroke. © 2014 John Wiley & Sons Ltd.

Distal radius: anatomical morphometric gender characteristics. Do anatomical pre-shaped plates pay attention on it?

PubMed

Oppermann, Johannes; Bredow, Jan; Beyer, Frank; Neiss, Wolfram Friedrich; Spies, Christian K; Eysel, Peer; Dargel, Jens; Wacker, Max

2015-01-01

The purpose of the study was to investigate differences in the osseous structure anatomy of male and female distal radii. Morphometric data were obtained of 49 distal human cadaveric radii. An imprint of the distal edge was attained using silicone mass and the palmar cortical angle (PCA) of the lateral and intermediate column, here declared as medial, according to the concept of Rikli and Rigazzoni. The lateral and medial length and five widths were digitally measured by three observers. In order to compare the measurements an unpaired t test was used. To prove the reliability of the measurements an intraclass correlation analyses was done. Overall mean medial PCA was 148.25° (SD ± 6.83) and mean lateral PCA 156.07° (SD ± 7.00). In male specimens, the mean medial PCA was 147.38° (SD ± 6.01) and mean lateral PCA was 153.6° (SD ± 6.20) whereas in female specimens, the mean medial PCA was 149.41° (SD ± 7.79) and the mean lateral PCA 159.37° (SD ± 6.78), with statistical significance for the female lateral PCA. No gender significant difference for the medial PCA and no significant side difference for the PCA's could be found. The ICC of the observers was r = 0.936 and 0.976 for the medial and for lateral PCA 0.957-0.984. The palmar cortical length of the distal radius was significantly longer in male specimens. For all widths, larger values for male radii were measured, being statistically significant in all cases. Male dimensions concerning the wide were significantly larger when compared with females. Regarding the PCA at the medial and lateral column, we found significant difference for lateral PCA concerning the gender. Overall, study results demonstrated an angle of 148.25° ± 6.83 for the medial PCA and 156.07° ± 7.00 for the lateral PCA.

Atraumatic splenic rupture and ileal volvulus following cocaine abuse.

PubMed

Ballard, David H; Smith, J Patrick; Samra, Navdeep S

2015-01-01

We present the case of a 38-year-old male with an atraumatic splenic rupture, hemoperitoneum, and ileal volvulus following acute cocaine intoxication. Computed tomography showed a "whirl sign", a subcapsular splenic hematoma with suspected peripheral laceration, and diffuse hemoperitoneum. At laparotomy, the spleen was confirmed to be the source of bleeding and was removed. A nonreducible volvulus was found at the distal ileum, and this segment of small bowel was removed. The patient had an uneventful postoperative recovery. Copyright © 2015 Elsevier Inc. All rights reserved.

Interstitial duplication 8q22-q24: Report of a case proven by FISH with mapped cosmid probes

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

Wakui, Keiko; Ohashi, Hirofumi; Yamagishi, Akira

We report on a 6-month-old malformed female infant with a de novo interstitial duplication of an 8q22-q24 segment. She had an excess dark-band on the 8q distal region by GTG-banded chromosome analysis, which was likely to be 8q23. We performed FISH analysis using cosmid probes mapped to 8q23 and proved that the patient had an 8q duplication including the 8q23 region. 20 refs., 2 figs., 1 tab.

Intravascular ultrasound evaluation of a pseudolesion created by stent placement in the right artery.

PubMed

Zientek, D M; Rodgers, G P

1999-10-01

The creation of a pseudolesion after guidewire placement in tortuous arterial segments is a well recognized phenomenon. Intravascular ultrasound has been useful in assessing deployment of intracoronary stents and equivocal angiographic findings. We present a case in which a pseudolesion was not observed until after placement of an intracoronary stent. Intravascular ultrasound demonstrated no dissection or significant lesion; however, there was focal calcification just distal to the stent providing a substrate for the distorted vessel architecture. The lesion resolved with removal of the guidewire.

BAC sequencing using pooled methods.

PubMed

Saski, Christopher A; Feltus, F Alex; Parida, Laxmi; Haiminen, Niina

2015-01-01

Shotgun sequencing and assembly of a large, complex genome can be both expensive and challenging to accurately reconstruct the true genome sequence. Repetitive DNA arrays, paralogous sequences, polyploidy, and heterozygosity are main factors that plague de novo genome sequencing projects that typically result in highly fragmented assemblies and are difficult to extract biological meaning. Targeted, sub-genomic sequencing offers complexity reduction by removing distal segments of the genome and a systematic mechanism for exploring prioritized genomic content through BAC sequencing. If one isolates and sequences the genome fraction that encodes the relevant biological information, then it is possible to reduce overall sequencing costs and efforts that target a genomic segment. This chapter describes the sub-genome assembly protocol for an organism based upon a BAC tiling path derived from a genome-scale physical map or from fine mapping using BACs to target sub-genomic regions. Methods that are described include BAC isolation and mapping, DNA sequencing, and sequence assembly.

[Surgical therapy of segmental jejunal, primary intestinal lymphangiectasia].

PubMed

Kneist, W; Drescher, D G; Hansen, T; Kreitner, K F; Lang, H

2013-06-01

Primary intestinal lymphangiectasia (PIL) is a protein-losing, exsudative gastroenteropathy causing lymphatic obstruction. Diagnosis depends on clinical examination and histological findings. Conservative treatment modalities include a low-fat diet and enteral nutritional therapy in order to reduce enteric protein loss and to improve fat metabolism. Other treatment options consist of administration of antiplasmin or octreotide to lower lymph flow and secretion. We report on a 58-year-old patient who underwent exploratory laparotomy due to a worsening physical status, recurrent chylaskos and leg oedema under conservative dietary therapy. Intraoperative findings showed a typical PIL of the jejunum about 20 cm distal to the Treitz's ligament. Histological examinations confirmed this diagnosis. One year after segmental small bowel resection (105 cm) with end-to-end anastomosis the patient is healthy, free of symptoms, has gained weight and his serum protein level has increased. Intraabdominal ascites and leg oedema have not reoccurred since.

Notch-dependent epithelial fold determines boundary formation between developmental fields in the Drosophila antenna.

PubMed

Ku, Hui-Yu; Sun, Y Henry

2017-07-01

Compartment boundary formation plays an important role in development by separating adjacent developmental fields. Drosophila imaginal discs have proven valuable for studying the mechanisms of boundary formation. We studied the boundary separating the proximal A1 segment and the distal segments, defined respectively by Lim1 and Dll expression in the eye-antenna disc. Sharp segregation of the Lim1 and Dll expression domains precedes activation of Notch at the Dll/Lim1 interface. By repressing bantam miRNA and elevating the actin regulator Enable, Notch signaling then induces actomyosin-dependent apical constriction and epithelial fold. Disruption of Notch signaling or the actomyosin network reduces apical constriction and epithelial fold, so that Dll and Lim1 cells become intermingled. Our results demonstrate a new mechanism of boundary formation by actomyosin-dependent tissue folding, which provides a physical barrier to prevent mixing of cells from adjacent developmental fields.

Rotational Distraction for the Treatment of Severe Mandibular Retrognathia

PubMed Central

Mitsugi, Masaharu; Alcalde, Rafael E.; Yano, Tomoyuki; Uemura, Noriko; Okazaki, Mutsumi

2015-01-01

Backgrounds: The main problem with intraoral distraction of the mandible is the inability to achieve the three-dimensional mandibular correction as planned preoperatively. We developed a technique that allows spontaneous changes in the direction of mandibular elongation using an intraoral distractor. Methods: After mandibular osteotomy, the distractor is fixed to the distal segment of the mandible using a single bicortical screw, allowing anterior-posterior, vertical and limited lateromedial changes in the vector of distraction. Mandibular lengthening is performed while keeping the maxilla and mandible in class I occlusion with intermaxillary fixation. Results: As the distraction device is activated allowing mandibular elongation, the proximal segment, guided by the surrounding soft tissues, moves and rotates posterosuperiorly. Mandibular lengthening is continued until the condylar head reaches an adequate position in the mandibular fossa as confirmed clinically and radiographically. Conclusion Thirty-three patients with mandibular retrognathia received this treatment and good results were obtained. PMID:26301156

Rotational Distraction for the Treatment of Severe Mandibular Retrognathia.

PubMed

Ito, Osamu; Mitsugi, Masaharu; Alcalde, Rafael E; Yano, Tomoyuki; Uemura, Noriko; Okazaki, Mutsumi

2015-07-01

The main problem with intraoral distraction of the mandible is the inability to achieve the three-dimensional mandibular correction as planned preoperatively. We developed a technique that allows spontaneous changes in the direction of mandibular elongation using an intraoral distractor. After mandibular osteotomy, the distractor is fixed to the distal segment of the mandible using a single bicortical screw, allowing anterior-posterior, vertical and limited lateromedial changes in the vector of distraction. Mandibular lengthening is performed while keeping the maxilla and mandible in class I occlusion with intermaxillary fixation. As the distraction device is activated allowing mandibular elongation, the proximal segment, guided by the surrounding soft tissues, moves and rotates posterosuperiorly. Mandibular lengthening is continued until the condylar head reaches an adequate position in the mandibular fossa as confirmed clinically and radiographically. Thirty-three patients with mandibular retrognathia received this treatment and good results were obtained.

Collateral Circulation in Chronic Total Occlusions - an interventional perspective.

PubMed

Choo, Gim-Hooi

2015-09-09

Human coronary collaterals are inter-coronary communications that are believed to be present from birth. In the presence of chronic total occlusions, recruitment of flow via these collateral anastomoses to the arterial segment distal to occlusion provide an alternative source of blood flow to the myocardial segment at risk. This mitigates the ischemic injury. Clinical outcome of coronary occlusion ie. severity of myocardial infarction/ischemia, impairment of cardiac function and possibly survival depends not only on the acuity of the occlusion, extent of jeopardized myocardium, duration of ischemia but also to the adequacy of collateral circulation. Adequacy of collateral circulation can be assessed by various methods. These coronary collateral channels have been used successfully as a retrograde access route for percutaneous recanalization of chronic total occlusions. Factors that promote angiogenesis and further collateral remodeling ie. arteriogenesis have been identified. Promotion of collateral growth as a therapeutic target in patients with no suitable revascularization option is an exciting proposal.

A Genetically Engineered Mouse Model of Sporadic Colorectal Cancer.

PubMed

Betzler, Alexander M; Kochall, Susan; Blickensdörfer, Linda; Garcia, Sebastian A; Thepkaysone, May-Linn; Nanduri, Lahiri K; Muders, Michael H; Weitz, Jürgen; Reissfelder, Christoph; Schölch, Sebastian

2017-07-06

Despite the advantages of easy applicability and cost-effectiveness, colorectal cancer mouse models based on tumor cell injection have severe limitations and do not accurately simulate tumor biology and tumor cell dissemination. Genetically engineered mouse models have been introduced to overcome these limitations; however, such models are technically demanding, especially in large organs such as the colon in which only a single tumor is desired. As a result, an immunocompetent, genetically engineered mouse model of colorectal cancer was developed which develops highly uniform tumors and can be used for tumor biology studies as well as therapeutic trials. Tumor development is initiated by surgical, segmental infection of the distal colon with adeno-cre virus in compound conditionally mutant mice. The tumors can be easily detected and monitored via colonoscopy. We here describe the surgical technique of segmental adeno-cre infection of the colon, the surveillance of the tumor via high-resolution colonoscopy and present the resulting colorectal tumors.

Intrauterine device for laser light diffusion and method of using the same

DOEpatents

Tadir, Yona; Berns, Michael W.; Svaasand, Lars O.; Tromberg, Bruce J.

1995-01-01

An improved device for delivery of photoenergy from a light source, such as a laser, into a uterine cavity for photodynamic therapy is comprised of a plurality of optic fibers, which are bundled together and inserted into the uterine cavity by means of a uterine cannula. The cannula is positioned within the uterine cavity at a preferred location and then withdrawn thereby allowing the plurality of optic fibers to splay or diverge one from the other within the cavity. Different portions of the distal tip of the optic fiber is provided with a light diffusing tip, the remainder being provided with a nondiffusing tip portion. The fiber optic shape, as well as the segment which is permitted to actively diffuse light through the tip, is selected in order to provide a more uniform exposure intensity of the photo energy or at least sufficient radiation directed to each segment of the uterine walls.

Intrauterine device for laser light diffusion and method of using the same

DOEpatents

Tadir, Y.; Berns, M.W.; Svaasand, L.O.; Tromberg, B.J.

1995-12-26

An improved device for delivery of photoenergy from a light source, such as a laser, into a uterine cavity for photodynamic therapy is comprised of a plurality of optic fibers, which are bundled together and inserted into the uterine cavity by means of a uterine cannula. The cannula is positioned within the uterine cavity at a preferred location and then withdrawn thereby allowing the plurality of optic fibers to splay or diverge one from the other within the cavity. Different portions of the distal tip of the optic fiber is provided with a light diffusing tip, the remainder being provided with a nondiffusing tip portion. The fiber optic shape, as well as the segment which is permitted to actively diffuse light through the tip, is selected in order to provide a more uniform exposure intensity of the photo energy or at least sufficient radiation directed to each segment of the uterine walls. 5 figs.

Two new stygobiotic species of Elaphoidella (Crustacea: Copepoda: Harpacticoida) with comments on geographical distribution and ecology of harpacticoids from caves in Thailand.

PubMed

Watiroyram, Santi; Brancelj, Anton; Sanoamuang, La-Orsri

2015-02-16

Elaphoidella thailandensis sp. nov. and E. jaesornensis sp. nov., collected during an investigation of cave-dwelling copepod fauna in the northern part of Thailand, are described and figured herein. The new species were collected from pools filled by percolating water from the unsaturated zone of a karstic aquifer in Phitsanulok and Lampang Provinces, respectively. Elaphoidella thailandensis, from Tham Khun cave, is distinguished from its congeners by the two-segmented endopod of pediger 1, the absence of endopod on pediger 4, and the setal formula 4, 5, 6 for the distal exopodal segment of pedigers 2-4. Elaphoidella jaesornensis, from Tham Phar Ngam cave, is distinguished from its most closely related species, E. namnaoensis Brancelj, Watiroyram & Sanoamuang, 2010, by the armature formula of the endopod of pedigers 2-5. The geographical distribution and ecology of Harpacticoida from Thai caves is also presented.

Case report of a rarely seen long-segment middle aortic syndrome.

PubMed

Yakut, Kahraman; Erdoğan, İlkay

2017-03-01

Middle aortic syndrome (MAS) follows a course with distal thoracic and abdominal aorta stenosis. It is a rare disease that is usually diagnosed after the first decade of life. Clinical reflection of MAS is often in the form of hypertension and claudication in the lower extremities. Its etiology is unclear, but is known to be associated with congenital or acquired diseases. This pathology, which is accompanied by malignant hypertension, often does not respond to medical treatment. In patients with MAS, surgical treatment is first line recommendation to prevent complications such as hypertension, heart failure, intracranial bleeding, or aortic rupture. In order to draw attention to this disease, presently described is case of high blood pressure detected during routine examination of a child who had no complaint, and discovery of long-segment stenosis in the abdominal aorta identified with echocardiography and conventional angiography.

Notch-dependent epithelial fold determines boundary formation between developmental fields in the Drosophila antenna

PubMed Central

2017-01-01

Compartment boundary formation plays an important role in development by separating adjacent developmental fields. Drosophila imaginal discs have proven valuable for studying the mechanisms of boundary formation. We studied the boundary separating the proximal A1 segment and the distal segments, defined respectively by Lim1 and Dll expression in the eye-antenna disc. Sharp segregation of the Lim1 and Dll expression domains precedes activation of Notch at the Dll/Lim1 interface. By repressing bantam miRNA and elevating the actin regulator Enable, Notch signaling then induces actomyosin-dependent apical constriction and epithelial fold. Disruption of Notch signaling or the actomyosin network reduces apical constriction and epithelial fold, so that Dll and Lim1 cells become intermingled. Our results demonstrate a new mechanism of boundary formation by actomyosin-dependent tissue folding, which provides a physical barrier to prevent mixing of cells from adjacent developmental fields. PMID:28708823

Contralateral structural femoral autograft use in treatment of an open periarticular knee fracture to perform knee arthrodesis.

PubMed

Mack, Andrew W; Helgeson, Melvin D; Tis, John E

2008-09-01

Combat-related blast injuries often cause devastating extremity trauma. We report a case of a 21-year-old male service member who sustained massive bilateral lower extremity trauma secondary to a blast injury. His orthopaedic injuries included a near traumatic disarticulation of the right knee and a left open type IIIB periarticular knee fracture with traumatic patellectomy, loss of the extensor mechanism, and segmental loss of the distal 11 cm of his femur. Definitive treatment of his injuries included a contralateral structural cortical femoral autograft which was implanted into the left knee segmental defect to facilitate knee fusion with an intramedullary knee fusion nail and a right transfemoral amputation. Radiographic evidence of solid fusion was obtained 8 months postoperatively. Currently, the patient is a community ambulator with the aid of his right lower extremity prosthetic limb and cane.

Can angiogenesis induced by chronic electrical stimulation enhance latissimus dorsi muscle flap survival for application in cardiomyoplasty?

PubMed

Overgoor, Max L E; Carroll, Sean M; Papanicolau, George; Carroll, Camilla M A; Ustüner, Tuncay E T; Stremel, Richard W; Anderson, Gary L; Franken, Ralph J P M; Kon, Moshe; Barker, John H

2003-01-01

In cardiomyoplasty, the latissimus dorsi muscle is lifted on its primary neurovascular pedicle and wrapped around a failing heart. After 2 weeks, it is trained for 6 weeks using chronic electrical stimulation, which transforms the latissimus dorsi muscle into a fatigue-resistant muscle that can contract in synchrony with the beating heart without tiring. In over 600 cardiomyoplasty procedures performed clinically to date, the outcomes have varied. Given the data obtained in animal experiments, the authors believe these variable outcomes are attributable to distal latissimus dorsi muscle flap necrosis. The aim of the present study was to investigate whether the chronic electrical stimulation training used to transform the latissimus dorsi muscle into fatigue-resistant muscle could also be used to induce angiogenesis, increase perfusion, and thus protect the latissimus dorsi muscle flap from distal necrosis. After 14 days of chronic electrical stimulation (10 Hz, 330 microsec, 4 to 6 V continuous, 8 hours/day) of the right or left latissimus dorsi muscle (randomly selected) in 11 rats, both latissimus dorsi muscles were lifted on their thoracodorsal pedicles and returned to their anatomical beds. Four days later, the resulting amount of distal flap necrosis was measured. Also, at predetermined time intervals throughout the experiment, muscle surface blood perfusion was measured using scanning laser Doppler flowmetry. Finally, latissimus dorsi muscles were excised in four additional stimulated rats, to measure angiogenesis (capillary-to-fiber ratio), fiber type (oxidative or glycolytic), and fiber size using histologic specimens. The authors found that chronic electrical stimulation (1) significantly (p < 0.05) increased angiogenesis (mean capillary-to-fiber ratio) by 82 percent and blood perfusion by 36 percent; (2) did not reduce the amount of distal flap necrosis compared with nonchronic electrical stimulation controls (29 +/- 5.3 percent versus 26.6 +/- 5.1 percent); (3) completely transformed the normally mixed (oxidative and glycolytic) fiber type distribution into all oxidative fibers; and (4) reduced fiber size in the proximal and middle but not in the distal segments of the flap. Despite the significant increase in angiogenesis and blood perfusion, distal latissimus dorsi muscle flap necrosis did not decrease. This might be because of three reasons: first, the change in muscle metabolism from anaerobic to aerobic may have rendered the muscle fibers more susceptible to ischemia. Second, because of the larger diameter of the distal fibers in normal and stimulated latissimus dorsi muscle, the diffusion distance for oxygen to the center of the distal fibers is increased, making fiber survival more difficult. Third, even though angiogenesis was significantly increased in the flap, cutting all but the single vascular pedicle resulted in the newly formed capillaries not receiving enough blood to provide nourishment to the distal latissimus dorsi muscle. The authors' findings indicate that chronic electrical stimulation as tested in these experiments could not be used to prevent distal latissimus dorsi muscle flap ischemia and necrosis in cardiomyoplasty.

Striatal somatotopy and motor responses evoked by acute electrical stimulation of the posterior striatum in rats.

PubMed

Vilela-Filho, Osvaldo; Barros, Breno A; Arruda, Mariana M; Castro, Thaisa S; Souza, Joaquim T; Silva, Delson J; Ferraz, Fernando P; Ragazzo, Paulo C

2014-02-01

Previous experiments suggest that the striatal sensorimotor territory in rats is located in its dorsolateral region, along the rostrocaudal axis, unlike what has been observed in primates. In the present study, electrical stimulation was performed to investigate the degree of participation of the posterior striatum in its motor territory, its somatotopic organization, and the motor responses evoked by stimulation. Twenty-five rats were submitted to stereotactic stimulation of the posterior striatum under general anesthesia, receiving consecutively four different current intensities. The motor responses observed in the different body parts were registered for later comparison. We considered as threshold the smallest of these current intensities able to evoke a motor response. The observed motor responses were qualitatively different for each segment: forepaws: ipsilateral, adduction, and contralateral abduction; hindpaws: ipsilateral, flexion, and contralateral, extension/abduction; trunk, rotation/flexion; and tail, rotation/elevation. High-frequency, small-amplitude distal tremor occurred in the ipsilateral forepaw in 95% of the animals. Progressively larger current intensities were necessary for the induction of motor response in the forepaws, hindpaws, and trunk/tail, in that order. The results allowed us to infer the following posterior striatal somatotopic organization: forepaws, posterolaterally, being the contralateral medial to the ipsilateral; trunk/tail, anteromedially; and hindpaws, in an intermediate position, being the contralateral posterior to the ipsilateral. It is suggested that the tremor and the other observed motor responses derive from the excitation of striatal projection neurons and that the striatum may play an important role in the genesis of essential tremor. © 2013 International Neuromodulation Society.

Partial lesions of the intratemporal segment of the facial nerve: graft versus partial reconstruction.

PubMed

Bento, Ricardo F; Salomone, Raquel; Brito, Rubens; Tsuji, Robinson K; Hausen, Mariana

2008-09-01

In cases of partial lesions of the intratemporal segment of the facial nerve, should the surgeon perform an intraoperative partial reconstruction, or partially remove the injured segment and place a graft? We present results from partial lesion reconstruction on the intratemporal segment of the facial nerve. A retrospective study on 42 patients who presented partial lesions on the intratemporal segment of the facial nerve was performed between 1988 and 2005. The patients were divided into 3 groups based on the procedure used: interposition of the partial graft on the injured area of the nerve (group 1; 12 patients); keeping the preserved part and performing tubulization (group 2; 8 patients); and dividing the parts of the injured nerve (proximal and distal) and placing a total graft of the sural nerve (group 3; 22 patients). Fracture of the temporal bone was the most frequent cause of the lesion in all groups, followed by iatrogenic causes (p < 0.005). Those who obtained results lower than or equal to III on the House-Brackmann scale were 1 (8.3%) of the patients in group 1, none (0.0%) of the patients in group 2, and 15 (68.2%) of the patients in group 3 (p <0.001). The best surgical technique for therapy of a partial lesion of the facial nerve is still questionable. Among these 42 patients, the best results were those from the total graft of the facial nerve.

Flexible growing rods: a pilot study to determine if polymer rod constructs may provide stability to skeletally immature spines

PubMed Central

2015-01-01

Background Surgical treatments for early onset scoliosis (EOS), including growing rod constructs, involve many complications. Some are due to biomechanical factors. A construct that is more flexible than current instrumentation systems may reduce complications. The purpose of this preliminary study was to determine spine range of motion (ROM) after implantation of simulated growing rod constructs with a range of clinically relevant structural properties. The hypothesis was that ROM of spines instrumented with polyetheretherketone (PEEK) rods would be greater than metal rods and lower than noninstrumented controls. Further, adjacent segment motion was expected to be lower with polymer rods compared to conventional systems. Methods Biomechanical tests were conducted on 6 skeletally immature porcine thoracic spines (domestic swine, 35-40 kg). Spines were harvested after death from swine that had been utilized for other studies (IACUC approved) which had not involved the spine. Paired pedicle screws were used as anchors at proximal and distal levels. Specimens were tested under the following conditions: control, then dual rods of PEEK (6.25 mm), titanium (4 mm), and CoCr (5 mm) alloy. Lateral bending (LB) and flexion-extension (FE) moments of ±5 Nm were applied. Vertebral rotations were measured using video. Differences were determined by two-tailed t-tests and Bonferroni correction with four primary comparisons: PEEK vs control and PEEK vs CoCr, in LB and FE (α=0.05/4). Results In LB, ROM of specimens with PEEK rods was lower than control at each instrumented level. ROM was greater for PEEK rods than both Ti and CoCr at every instrumented level. Mean ROM at proximal and distal noninstrumented levels was lower for PEEK than for Ti and CoCr. In FE, mean ROM at proximal and distal noninstrumented levels was lower for PEEK than for metal. Combining treated levels, in LB, ROM for PEEK rods was 35% of control (p<0.0001) and 270% of CoCr rods (p<0.01). In FE, ROM with PEEK was 27% of control (p<0.001) and 180% of CoCr (p<0.01). Conclusions PEEK rods decreased flexibility versus noninstumented controls, and increased flexibility versus metal rods. Smaller increases in ROM at proximal and distal adjacent motion segments occurred with PEEK compared to metal rods, which may help decrease junctional kyphosis. Flexible growing rods may eventually help improve treatment options for young patients with severe deformity. PMID:25810752

Polarization image segmentation of radiofrequency ablated porcine myocardial tissue

PubMed Central

Ahmad, Iftikhar; Gribble, Adam; Murtza, Iqbal; Ikram, Masroor; Pop, Mihaela; Vitkin, Alex

2017-01-01

Optical polarimetry has previously imaged the spatial extent of a typical radiofrequency ablated (RFA) lesion in myocardial tissue, exhibiting significantly lower total depolarization at the necrotic core compared to healthy tissue, and intermediate values at the RFA rim region. Here, total depolarization in ablated myocardium was used to segment the total depolarization image into three (core, rim and healthy) zones. A local fuzzy thresholding algorithm was used for this multi-region segmentation, and then compared with a ground truth segmentation obtained from manual demarcation of RFA core and rim regions on the histopathology image. Quantitative comparison of the algorithm segmentation results was performed with evaluation metrics such as dice similarity coefficient (DSC = 0.78 ± 0.02 and 0.80 ± 0.02), sensitivity (Sn = 0.83 ± 0.10 and 0.91 ± 0.08), specificity (Sp = 0.76 ± 0.17 and 0.72 ± 0.17) and accuracy (Acc = 0.81 ± 0.09 and 0.71 ± 0.10) for RFA core and rim regions, respectively. This automatic segmentation of parametric depolarization images suggests a novel application of optical polarimetry, namely its use in objective RFA image quantification. PMID:28380013