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Sample records for perfused term human

  1. Long term perfusion system supporting adipogenesis

    PubMed Central

    Abbott, Rosalyn D.; Raja, Waseem K.; Wang, Rebecca Y.; Stinson, Jordan A.; Glettig, Dean L.; Burke, Kelly A.; Kaplan, David L.

    2015-01-01

    Adipose tissue engineered models are needed to enhance our understanding of disease mechanisms and for soft tissue regenerative strategies. Perfusion systems generate more physiologically relevant and sustainable adipose tissue models, however adipocytes have unique properties that make culturing them in a perfusion environment challenging. In this paper we describe the methods involved in the development of two perfusion culture systems (2D and 3D) to test their applicability for long term in vitro adipogenic cultures. It was hypothesized that a silk protein biomaterial scaffold would provide a 3D framework, in combination with perfusion flow, to generate a more physiologically relevant sustainable adipose tissue engineered model than 2D cell culture. Consistent with other studies evaluating 2D and 3D culture systems for adipogenesis we found that both systems successfully model adipogensis, however 3D culture systems were more robust, providing the mechanical structure required to contain the large, fragile adipocytes that were lost in 2D perfused culture systems. 3D perfusion also stimulated greater lipogenesis and lipolysis and resulted in decreased secretion of LDH compared to 2D perfusion. Regardless of culture configuration (2D or 3D) greater glycerol was secreted with the increased nutritional supply provided by perfusion of fresh media. These results are promising for adipose tissue engineering applications including long term cultures for studying disease mechanisms and regenerative approaches, where both acute (days to weeks) and chronic (weeks to months) cultivation are critical for useful insight. PMID:25843606

  2. Perfusion harmonic imaging of the human brain

    NASA Astrophysics Data System (ADS)

    Metzler, Volker H.; Seidel, Guenter; Wiesmann, Martin; Meyer, Karsten; Aach, Til

    2003-05-01

    The fast visualisation of cerebral microcirculation supports diagnosis of acute cerebrovascular diseases. However, the commonly used CT/MRI-based methods are time consuming and, moreover, costly. Therefore we propose an alternative approach to brain perfusion imaging by means of ultrasonography. In spite of the low signal/noise-ratio of transcranial ultrasound and the high impedance of the skull, flow images of cerebral blood flow can be derived by capturing the kinetics of appropriate contrast agents by harmonic ultrasound image sequences. In this paper we propose three different methods for human brain perfusion imaging, each of which yielding flow images indicating the status of the patient's cerebral microcirculation by visualising local flow parameters. Bolus harmonic imaging (BHI) displays the flow kinetics of bolus injections, while replenishment (RHI) and diminution harmonic imaging (DHI) compute flow characteristics from contrast agent continuous infusions. RHI measures the contrast agents kinetics in the influx phase and DHI displays the diminution kinetics of the contrast agent acquired from the decay phase. In clinical studies, BHI- and RHI-parameter images were found to represent comprehensive and reproducible distributions of physiological cerebral blood flow. For DHI it is shown, that bubble destruction and hence perfusion phenomena principally can be displayed. Generally, perfusion harmonic imaging enables reliable and fast bedside imaging of human brain perfusion. Due to its cost efficiency it complements cerebrovascular diagnostics by established CT/MRI-based methods.

  3. ABCG2/BCRP decreases the transfer of a food-born chemical carcinogen, 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) in perfused term human placenta

    SciTech Connect

    Myllynen, Paeivi Kummu, Maria; Kangas, Tiina; Ilves, Mika; Immonen, Elina; Rysae, Jaana; Pirilae, Rauna; Lastumaeki, Anni; Vaehaekangas, Kirsi H.

    2008-10-15

    We have studied the role of ATP binding cassette (ABC) transporters in fetal exposure to carcinogens using 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) a known substrate for ABC transporters as a model compound. In perfusion of human term placenta, transfer of {sup 14}C-PhIP (2 {mu}M) through the placenta resulted in fetal-to-maternal concentration ratio (FM ratio) of 0.72 {+-} 0.09 at 6 h. The specific ABCG2 inhibitor KO143 increased the transfer of {sup 14}C-PhIP from maternal to fetal circulation (FM ratio 0.90 {+-} 0.08 at 6 h, p < 0.05) while the ABCC1/ABCC2 inhibitor probenecid had no effect (FM ratio at 6 h 0.75 {+-} 0.10, p = 0.84). There was a negative correlation between the expression of ABCG2 protein in perfused tissue and the FM ratio of {sup 14}C-PhIP (R = - 0.81, p < 0.01) at the end of the perfusion. The expression of ABCC2 protein did not correlate with FM ratio of PhIP (R: - 0.11, p = 0.76). In addition, PhIP induced the expression of ABC transporters in BeWo cells at mRNA level. In conclusion, our data indicates that ABCG2 decreases placental transfer of {sup 14}C-PhIP in perfused human placenta. Also, PhIP may modify ABC transporter expression in choriocarinoma cells.

  4. Trophoblast viability in perfused term placental tissue and explant cultures limited to 7-24 hours.

    PubMed

    Di Santo, S; Malek, A; Sager, R; Andres, A-C; Schneider, H

    2003-01-01

    Human term-placental culture techniques such as villous explant or dual perfusion are commonly used to study trophoblast function under control and experimentally manipulated conditions. We have compared trophoblast viability during perfusion and in explants cultured under various conditions by monitoring glucose consumption, protein synthesis and secretion, expression of differentiation-specific genes, induction of stress proteins and apoptotic cell death. The tissue was obtained from term-placentae of uncomplicated pregnancies after elective Caesarean delivery. We observed a severe loss of trophoblast viability in explants irrespective of the culture conditions used. Over 7 h of culture the amount of the differentiation specific placental hormones hCG, hPL and leptin accumulated in the medium dropped significantly. Analysis of their expression by semi-quantitative and real-time RT-PCR revealed that the down-regulation of expression occurred at the transcriptional level. This transcriptional repression was accompanied by induction of the stress-proteins RTP and BiP/GRP78. Analysis of apoptotic cell death by TUNEL assay and immunohistochemical detection of the caspase-3-specific degradation product of cytokeratin 18 revealed prominent cell death after 7 h of culture. These results are in contrast to the findings obtained in perfused placental tissue where, after 7 h of culture, hormone secretion, expression of stress proteins and cell death were similar as in native tissue. This difference between villous explant incubation and dual perfusion is also reflected by a significantly higher consumption of glucose in perfused tissue. PMID:13129686

  5. In Vitro Perfused Human Capillary Networks

    PubMed Central

    Moya, Monica L.; Hsu, Yu-Hsiang; Lee, Abraham P.; Hughes, Christopher C.W.

    2013-01-01

    Replicating in vitro the complex in vivo tissue microenvironment has the potential to transform our approach to medicine and also our understanding of biology. In order to accurately model the 3D arrangement and interaction of cells and extracellular matrix, new microphysiological systems must include a vascular supply. The vasculature not only provides the necessary convective transport of oxygen, nutrients, and waste in 3D culture, but also couples and integrates the responses of organ systems. Here we combine tissue engineering and microfluidic technology to create an in vitro 3D metabolically active stroma (∼1 mm3) that, for the first time, contains a perfused, living, dynamic, interconnected human capillary network. The range of flow rate (μm/s) and shear rate (s−1) within the network was 0–4000 and 0–1000, respectively, and thus included the normal physiological range. Infusion of FITC dextran demonstrated microvessels (15–50 μm) to be largely impermeable to 70 kDa. Our high-throughput biology-directed platform has the potential to impact a broad range of fields that intersect with the microcirculation, including tumor metastasis, drug discovery, vascular disease, and environmental chemical toxicity. PMID:23320912

  6. Ventilation-perfusion matching in long-term microgravity

    NASA Technical Reports Server (NTRS)

    Verbandt, Y.; Wantier, M.; Prisk, G. K.; Paiva, M.; West, J. B. (Principal Investigator)

    2000-01-01

    We studied the ventilation-perfusion matching pattern in normal gravity (1 G) and short- and long-duration microgravity (microG) using the cardiogenic oscillations in the sulfur hexaflouride (SF(6)) and CO(2) concentration signals during the phase III portion of vital capacity single-breath washout experiments. The signal power of the cardiogenic concentration variations was assessed by spectral analysis, and the phase angle between the oscillations of the two simultaneously expired gases was obtained through cross-correlation. For CO(2), a significant reduction of cardiogenic power was observed in microG, with respect to 1 G, but the reduction was smaller and more variable in the case of SF(6). A shift from an in-phase condition in 1 G to an out-of-phase condition was found for both short- and long-duration microG. We conclude that, although the distribution of ventilation and perfusion becomes more homogeneous in microG, significant inhomogeneities persist and that areas of high perfusion become associated with areas of relatively lower ventilation. In addition, these modifications seem to remain constant during long-term exposure to microG.

  7. The culture of human embryonic stem cells in microchannel perfusion bioreactors

    NASA Astrophysics Data System (ADS)

    Korin, Natanel; Bransky, Avishay; Dinnar, Uri; Levenberg, Shulamit

    2007-12-01

    The culture of human Embryonic Stem (ES) cells in microchannel bioreactors can be highly beneficial for ES cell biology studies and ES tissue engineering applications. In the present study we examine the use of Human Foreskin Fibroblasts (HFF) cells as feeder cells for human ES culture in a microchannel perfusion bioreactor. PDMS microchannels (depth:130 micron) were fabricated using conventional soft-lithography techniques. The channels were sterilized, coated with a human fibronectin solution and seeded with cells. Following a period of static incubation, culture medium was perfused through the channels at various flow rates and cell growth was monitored throughout the culture process. Mass transport and fluid mechanics models were used to evaluate the culture conditions (shear stress, oxygen levels within the micro-bioreactor as a function of the medium flow rate. The conditions for successful long-term culture (>7 days) of HFF under flow were established. Experiments with human embryonic stem cells cultured in microchannels show that the conditions essential to co-culture human ES cell on HFF cells under perfusion differ from the conditions necessary for HFF cell culture. Human ES cells were found to be highly sensitive to flow and culture conditions and did not grow under flow rates which were suitable for HFF long-term culture. Successful culture of undifferentiated human ES cell colonies in a perfusion micro-bioreactor is a basic step towards utilizing microfluidic techniques to explore stem cell biology.

  8. Skin Blood Perfusion and Oxygenation Colour Affect Perceived Human Health

    PubMed Central

    Stephen, Ian D.; Coetzee, Vinet; Law Smith, Miriam; Perrett, David I.

    2009-01-01

    Skin blood perfusion and oxygenation depends upon cardiovascular, hormonal and circulatory health in humans and provides socio-sexual signals of underlying physiology, dominance and reproductive status in some primates. We allowed participants to manipulate colour calibrated facial photographs along empirically-measured oxygenated and deoxygenated blood colour axes both separately and simultaneously, to optimise healthy appearance. Participants increased skin blood colour, particularly oxygenated, above basal levels to optimise healthy appearance. We show, therefore, that skin blood perfusion and oxygenation influence perceived health in a way that may be important to mate choice. PMID:19337378

  9. The effects of perfusion conditions on melphalan distribution in the isolated perfused rat hindlimb bearing a human melanoma xenograft.

    PubMed

    Wu, Z Y; Smithers, B M; Parsons, P G; Roberts, M S

    1997-01-01

    An isolated rat hindlimb perfusion model carrying xenografts of the human melanoma cell line MM96 was used to study the effects of perfusion conditions on melphalan distribution. Krebs-Henseleit buffer and Hartmann's solution containing 4.7% bovine serum albumin (BSA) or 2.8% dextran 40 were used as perfusates. Melphalan concentrations in perfusate, tumour nodules and normal tissues were measured using high-performance liquid chromatography (HPLC). Increasing the perfusion flow rates (from 4 to 8 ml min(-1)) resulted in higher tissue blood flow (determined with 51Cr-labelled microspheres) and melphalan uptake by tumour and normal tissues. The distribution of melphalan within tumour nodules and normal tissues was similar for both Krebs-Henseleit buffer and Hartmann's solution; however, tissue concentrations of melphalan were significantly higher for a perfusate containing 2.8% dextran 40 than for one containing 4.7% BSA. The melphalan concentration in the tumour was one-third of that found in the skin if the perfusate contained 4.7% BSA. In conclusion, this study has shown that a high perfusion flow enhances the delivery of melphalan into implanted tumour nodules and normal tissues, and a perfusate with low melphalan binding (no albumin) is preferred for maximum uptake of drug by the tumour. PMID:9099965

  10. Ex Vivo Perfusion Treatment of Infection in Human Donor Lungs.

    PubMed

    Nakajima, D; Cypel, M; Bonato, R; Machuca, T N; Iskender, I; Hashimoto, K; Linacre, V; Chen, M; Coutinho, R; Azad, S; Martinu, T; Waddell, T K; Hwang, D M; Husain, S; Liu, M; Keshavjee, S

    2016-04-01

    Ex vivo lung perfusion (EVLP) is a platform to treat infected donor lungs with antibiotic therapy before lung transplantation. Human donor lungs that were rejected for transplantation because of clinical concern regarding infection were randomly assigned to two groups. In the antibiotic group (n = 8), lungs underwent EVLP for 12 h with high-dose antibiotics (ciprofloxacin 400 mg or azithromycin 500 mg, vancomycin 15 mg/kg, and meropenem 2 g). In the control group (n = 7), lungs underwent EVLP for 12 h without antibiotics. A quantitative decrease in bacterial counts in bronchoalveolar lavage (BAL) was found in all antibiotic-treated cases but in only two control cases. Perfusate endotoxin levels at 12 h were significantly lower in the antibiotic group compared with the control group. EVLP with broad-spectrum antibiotic therapy significantly improved pulmonary oxygenation and compliance and reduced pulmonary vascular resistance. Perfusate endotoxin levels at 12 h were strongly correlated with levels of perfusates tumor necrosis factor α, IL-1β and macrophage inflammatory proteins 1α and 1β at 12 h. In conclusion, EVLP treatment of infected donor lungs with broad-spectrum antibiotics significantly reduced BAL bacterial counts and endotoxin levels and improved donor lung function. PMID:26730551

  11. A microfluidically perfused three dimensional human liver model.

    PubMed

    Rennert, Knut; Steinborn, Sandra; Gröger, Marko; Ungerböck, Birgit; Jank, Anne-Marie; Ehgartner, Josef; Nietzsche, Sandor; Dinger, Julia; Kiehntopf, Michael; Funke, Harald; Peters, Frank T; Lupp, Amelie; Gärtner, Claudia; Mayr, Torsten; Bauer, Michael; Huber, Otmar; Mosig, Alexander S

    2015-12-01

    Within the liver, non-parenchymal cells (NPCs) are critically involved in the regulation of hepatocyte polarization and maintenance of metabolic function. We here report the establishment of a liver organoid that integrates NPCs in a vascular layer composed of endothelial cells and tissue macrophages and a hepatic layer comprising stellate cells co-cultured with hepatocytes. The three-dimensional liver organoid is embedded in a microfluidically perfused biochip that enables sufficient nutrition supply and resembles morphological aspects of the human liver sinusoid. It utilizes a suspended membrane as a cell substrate mimicking the space of Disse. Luminescence-based sensor spots were integrated into the chip to allow online measurement of cellular oxygen consumption. Application of microfluidic flow induces defined expression of ZO-1, transferrin, ASGPR-1 along with an increased expression of MRP-2 transporter protein within the liver organoids. Moreover, perfusion was accompanied by an increased hepatobiliary secretion of 5(6)-carboxy-2',7'-dichlorofluorescein and an enhanced formation of hepatocyte microvilli. From this we conclude that the perfused liver organoid shares relevant morphological and functional characteristics with the human liver and represents a new in vitro research tool to study human hepatocellular physiology at the cellular level under conditions close to the physiological situation. PMID:26322723

  12. Rapid decrease in tumor perfusion following VEGF blockade predicts long-term tumor growth inhibition in preclinical tumor models.

    PubMed

    Eichten, Alexandra; Adler, Alexander P; Cooper, Blerta; Griffith, Jennifer; Wei, Yi; Yancopoulos, George D; Lin, Hsin Chieh; Thurston, Gavin

    2013-04-01

    Vascular endothelial growth factor (VEGF) is a key upstream mediator of tumor angiogenesis, and blockade of VEGF can inhibit tumor angiogenesis and decrease tumor growth. However, not all tumors respond well to anti-VEGF therapy. Despite much effort, identification of early response biomarkers that correlate with long-term efficacy of anti-VEGF therapy has been difficult. These difficulties arise in part because the functional effects of VEGF inhibition on tumor vessels are still unclear. We therefore assessed rapid molecular, morphologic and functional vascular responses following treatment with aflibercept (also known as VEGF Trap or ziv-aflibercept in the United States) in preclinical tumor models with a range of responses to anti-VEGF therapy, including Colo205 human colorectal carcinoma (highly sensitive), C6 rat glioblastoma (moderately sensitive), and HT1080 human fibrosarcoma (resistant), and correlated these changes to long-term tumor growth inhibition. We found that an overall decrease in tumor vessel perfusion, assessed by dynamic contrast-enhanced ultrasound (DCE-US), and increases in tumor hypoxia correlated well with long-term tumor growth inhibition, whereas changes in vascular gene expression and microvessel density did not. Our findings support previous clinical studies showing that decreased tumor perfusion after anti-VEGF therapy (measured by DCE-US) correlated with response. Thus, measuring tumor perfusion changes shortly after treatment with VEGF inhibitors, or possibly other anti-angiogenic therapies, may be useful to predict treatment efficacy. PMID:23238831

  13. Placental Transfer of Rilpivirine in an Ex Vivo Human Cotyledon Perfusion Model

    PubMed Central

    Duro, Dominique; Belissa, Emilie; Peytavin, Gilles

    2015-01-01

    Placental transfers of the HIV nonnucleoside reverse transcriptase inhibitor rilpivirine were investigated in 8 term human cotyledons perfused with rilpivirine (400 ng/ml) in the maternal-to-fetal direction. The mean fetal transfer rate (FTR) (fetal/maternal concentration at steady state from 15 to 90 min) was 26% ± 8% (mean ± standard deviation), and the clearance index (rilpivirine FTR/antipyrine FTR) was 61% ± 20%. This shows that rilpivirine crosses the placenta at a relatively high rate, suggesting that the fetus is exposed to the compound during treatment of the mother. PMID:25691637

  14. Whole ovine ovaries as a model for human: perfusion with cryoprotectants in vivo and in vitro.

    PubMed

    Isachenko, Vladimir; Rahimi, Gohar; Dattena, Maria; Mallmann, Peter; Baikoshkarova, Saltanat; Kellerwessel, Elisabeth; Otarbaev, Marat; Shalakhmetova, Tamara; Isachenko, Evgenia

    2014-01-01

    These experiments were performed to test the perfusion of ovine as a model for human ovaries by cryoprotectants in vivo at high temperature when the permeability of capillaries is high and when blood is insensibly replaced by the solution of cryoprotectants. By our hypothetical supposition, ovaries could be saturated by cryoprotectants before their surgical removal. The objective was to examine the effectiveness of perfusion of ovine ovaries with vascular pedicle in vivo and in vitro. Arteria ovarica was cannuled and ovaries were perfused by Leibovitz L-15 medium + 100 IU/mL heparin + 5% bovine calf serum + 6% dimethyl sulfoxide + 6% ethylene glycol + 0.15 M sucrose + Indian ink in vivo and in vitro. In the first and second cycle of experiments, ovaries (n = 13 and n = 23) were perfused in vivo and in vitro, respectively, during 60 min with the rate of perfusion 50 mL/h (0.8 mL/min). It was established with in vivo perfusion that only about 10% of ovarian tissues were perfused due to an appearance of multiple anastomoses when the perfusion medium goes from arteria ovarica to arteria uterina without inflow into the ovaries. It was concluded that in vitro perfusion of ovine intact ovaries with vascular pedicle by freezing medium is more effective than this manipulation performed in vivo. PMID:24701576

  15. Labetalol does not decrease placental perfusion in the hypertensive term-pregnant rat.

    PubMed

    Ahokas, R A; Mabie, W C; Sibai, B M; Anderson, G D

    1989-02-01

    The acute effect of labetalol hydrochloride, a combined nonspecific beta-adrenergic and postsynaptic alpha 1-adrenergic blocker, on maternal hemodynamics and organ perfusion was investigated in 10 hypertensive, term-pregnant, spontaneously hypertensive rats with the use of the radioactive-labeled microsphere technique. The normal fall in blood pressure during pregnancy was prevented by the reduction of litter size to two conceptuses on day 7 of gestation. Labetalol (1 to 6 mg/kg) effectively lowered mean arterial pressure 22% by decreasing cardiac output 16%; total peripheral resistance was not significantly decreased. Thus, the blood pressure lowering effect of labetalol was due primarily to its beta-adrenergic blocking effect. Regional flows to the carcass and splanchnic circulation were decreased 19% and 15%, respectively, after labetalol administration. Uterine wall and ovarian perfusion were significantly reduced, but placental perfusion was not significantly altered. Because labetalol lowers blood pressure without reducing placental perfusion, it may be a useful alternative to hydralazine for the treatment of hypertensive emergencies in pregnancy. PMID:2916636

  16. Functional Human Liver Preservation and Recovery by Means of Subnormothermic Machine Perfusion

    PubMed Central

    Weeder, Pepijn D.; Sridharan, Gautham V.; Uygun, Basak E.; Karimian, Negin G.; Porte, Robert J.; Markmann, James F.; Yeh, Heidi; Uygun, Korkut

    2015-01-01

    There is currently a severe shortage of liver grafts available for transplantation. Novel organ preservation techniques are needed to expand the pool of donor livers. Machine perfusion of donor liver grafts is an alternative to traditional cold storage of livers and holds much promise as a modality to expand the donor organ pool. We have recently described the potential benefit of subnormothermic machine perfusion of human livers. Machine perfused livers showed improving function and restoration of tissue ATP levels. Additionally, machine perfusion of liver grafts at subnormothermic temperatures allows for objective assessment of the functionality and suitability of a liver for transplantation. In these ways a great many livers that were previously discarded due to their suboptimal quality can be rescued via the restorative effects of machine perfusion and utilized for transplantation. Here we describe this technique of subnormothermic machine perfusion in detail. Human liver grafts allocated for research are perfused via the hepatic artery and portal vein with an acellular oxygenated perfusate at 21 °C. PMID:25938299

  17. Inosculation and perfusion of pre-vascularized tissue patches containing aligned human microvessels after myocardial infarction.

    PubMed

    Riemenschneider, Sonja B; Mattia, Donald J; Wendel, Jacqueline S; Schaefer, Jeremy A; Ye, Lei; Guzman, Pilar A; Tranquillo, Robert T

    2016-08-01

    A major goal of tissue engineering is the creation of pre-vascularized tissues that have a high density of organized microvessels that can be rapidly perfused following implantation. This is especially critical for highly metabolic tissues like myocardium, where a thick myocardial engineered tissue would require rapid perfusion within the first several days to survive transplantation. In the present work, tissue patches containing human microvessels that were either randomly oriented or aligned were placed acutely on rat hearts post-infarction and for each case it was determined whether rapid inosculation could occur and perfusion of the patch could be maintained for 6 days in an infarct environment. Patches containing self-assembled microvessels were formed by co-entrapment of human blood outgrowth endothelial cells and human pericytes in fibrin gel. Cell-induced gel contraction was mechanically-constrained resulting in samples with high densities of microvessels that were either randomly oriented (with 420 ± 140 lumens/mm(2)) or uniaxially aligned (with 940 ± 240 lumens/mm(2)) at the time of implantation. These patches were sutured onto the epicardial surface of the hearts of athymic rats following permanent ligation of the left anterior descending artery. In both aligned and randomly oriented microvessel patches, inosculation occurred and perfusion of the transplanted human microvessels was maintained, proving the in vivo vascularization potential of these engineered tissues. No difference was found in the number of human microvessels that were perfused in the randomly oriented (111 ± 75 perfused lumens/mm(2)) and aligned (173 ± 97 perfused lumens/mm(2)) patches. Our results demonstrate that tissue patches containing a high density of either aligned or randomly oriented human pre-formed microvessels achieve rapid perfusion in the myocardial infarct environment - a necessary first-step toward the creation of a thick, perfusable heart patch. PMID

  18. Kinetic assessment of manganese using magnetic resonance imaging in the dually perfused human placenta in vitro

    SciTech Connect

    Miller, R.K.; Mattison, D.R.; Panigel, M.; Ceckler, T.; Bryant, R.; Thomford, P.

    1987-10-01

    The transfer and distribution of paramagnetic manganese was investigated in the dually perfused human placenta in vitro (using 10, 20, 100 ..mu..M Mn with and without /sup 54/Mn) using magnetic resonance imaging (MRI) and conventional radiochemical techniques. The human placenta concentrated /sup 54/Mn rapidly during the first 15 min of perfusion and by 4 hr was four times greater than the concentrations of Mn in the maternal perfusate, while the concentration of Mn in the fetal perfusate was 25% of the maternal perfusate levels. Within placentae, 45% of the /sup 54/Mn was free in the 100,000g supernatant, with 45% in the 1000g pellet. The magnetic field dependence of proton nuclear spin-lattice relaxation time (T/sub 1/) in placental tissue supports this Mn binding. Mn primarily affected the MRI partial saturation rather than spin-echo images of the human placenta, which provided for the separation of perfusate contributions from those produced by Mn. The washout of the Mn from the placenta was slow compared with its uptake, as determined by MRI. Thus, Mn was concentrated by the human placenta, but transfer of Mn across the placenta was limited in either direction. These studies also illustrate the opportunity for studies of human placental function using magnetic resonance imaging as a noninvasive biomarker.

  19. Regional pulmonary perfusion following human heart-lung transplantation

    SciTech Connect

    Lisbona, R.; Hakim, T.S.; Dean, G.W.; Langleben, D.; Guerraty, A.; Levy, R.D. )

    1989-08-01

    Ventilation and perfusion scans were obtained in six subjects who had undergone heart-lung transplantation with consequent denervation of the cardiopulmonary axis. Two of the subjects had developed obliterative bronchiolitis, which is believed to be a form of chronic rejection. Their pulmonary function tests demonstrated airflow obstruction and their scintigraphic studies were abnormal. In the remaining four subjects without obstructive airways disease, ventilation and planar perfusion scans were normal. Single photon emission computed tomography imaging of pulmonary perfusion in these patients revealed a layered distribution of blood flow indistinguishable from that of normal individuals. It is concluded that neurogenic mechanisms have little influence on the pattern of local pulmonary blood flow at rest.

  20. A Device for Long-Term Perfusion, Imaging, and Electrical Interfacing of Brain Tissue In vitro

    PubMed Central

    Killian, Nathaniel J.; Vernekar, Varadraj N.; Potter, Steve M.; Vukasinovic, Jelena

    2016-01-01

    Distributed microelectrode array (MEA) recordings from consistent, viable, ≥500 μm thick tissue preparations over time periods from days to weeks may aid in studying a wide range of problems in neurobiology that require in vivo-like organotypic morphology. Existing tools for electrically interfacing with organotypic slices do not address necrosis that inevitably occurs within thick slices with limited diffusion of nutrients and gas, and limited removal of waste. We developed an integrated device that enables long-term maintenance of thick, functionally active, brain tissue models using interstitial perfusion and distributed recordings from thick sections of explanted tissue on a perforated multi-electrode array. This novel device allows for automated culturing, in situ imaging, and extracellular multi-electrode interfacing with brain slices, 3-D cell cultures, and potentially other tissue culture models. The device is economical, easy to assemble, and integrable with standard electrophysiology tools. We found that convective perfusion through the culture thickness provided a functional benefit to the preparations as firing rates were generally higher in perfused cultures compared to their respective unperfused controls. This work is a step toward the development of integrated tools for days-long experiments with more consistent, healthier, thicker, and functionally more active tissue cultures with built-in distributed electrophysiological recording and stimulation functionality. The results may be useful for the study of normal processes, pathological conditions, and drug screening strategies currently hindered by the limitations of acute (a few hours long) brain slice preparations. PMID:27065793

  1. Preliminary Study of Open Quotient in an Ex-Vivo Perfused Human Larynx Model

    PubMed Central

    Mendelsohn, Abie H.; Zhang, Zhaoyan; Luegmair, Georg; Orestes, Michael; Berke, Gerald S.

    2016-01-01

    Importance Scientific understanding human voice production to date is a product of indirect investigations including animal models, cadaveric tissue study, or computational modeling. Due to its invasive nature, direct experimentation of human voice production has previously not been possible. The feasibility of an ex-vivo perfused human phonatory model has recently allowed systematic investigation in virtually living human larynges with parametric laryngeal muscle stimulation. Objective In this study, the relationship between adductor muscle group stimulation and the open quotient (OQ) of vocal fold vibration was investigated using an ex-vivo perfused human larynx. Design Human perfused tissue study. Setting Physiology Laboratory. Participants Human larynx is recovered from research-consented organ donors within two hours of cardiac death. Interventions, Main Outcomes and Measures Perfusion with donated human blood is re-established shortly after cardiac death. Human perfused phonation is achieved by providing subglottal airflow under graded neuromuscular electrical stimulation bilaterally to the intrinsic adductor groups and cricothyroid muscles. The phonation resulting from the graded states of neuromuscular stimulations are evaluated through high-speed vibratory imaging. OQ is derived through digital kymography and glottal area waveform analysis. Results Under constant glottal flow, step-wise increase in adductor muscle group stimulation decreased OQ. Quantitatively, OQ values reached a lower limit of 0.42. Increased stimulation above maximal muscle deformation was unable to affect OQ beyond this lower limit. Conclusions and Relevance For the first time in a neuromuscularly activated human larynx, a negative relationship between adductor muscle group stimulation and phonatory OQ was demonstrated. Further experience with the ex-vivo perfused human phonatory model will work to systematically define this causal relationship. PMID:26181642

  2. Residual heterogeneity of intra- and interregional pulmonary perfusion in short-term microgravity.

    PubMed

    Montmerle, Stéphanie; Sundblad, Patrik; Linnarsson, Dag

    2005-06-01

    We hypothesized that the perfusion heterogeneity in the human, upright lung is determined by nongravitational more than gravitational factors. Twelve and six subjects were studied during two series of parabolic flights. We used cardiogenic oscillations of O(2)/SF(6) as an indirect estimate of intraregional perfusion heterogeneity (series 1) and phase IV amplitude (P(4)) as a indirect estimate of interregional perfusion heterogeneity (series 2). A rebreathing-breath holding-expiration maneuver was performed. In flight, breath holding and expiration were performed either in microgravity (0 G) or in hypergravity. Controls were performed at normal gravity (1 G). In series 1, expiration was performed at 0 G. Cardiogenic oscillations of O(2)/SF(6) were 19% lower when breath holding was performed at 0 G than when breath holding was performed at 1 G [means (SD): 1.7 (0.3) and 2.3 (0.6)% units] (P = 0.044). When breath holding was performed at 1.8 G, values did not differ from 1-G control [2.6 (0.8)% units, P = 0.15], but they were 17% larger at 1.8 G than at 1 G. In series 2, expiration was performed at 1.7 G. P(4) changed with gravity (P < 0.001). When breath holding was performed at 0 G, P(4) values were 45 (46)% of control. When breath holding was performed at 1.7 G, P(4) values were 183 (101)% of control. We conclude that more than one-half of indexes of perfusion heterogeneity at 1 G are caused by nongravitational mechanisms. PMID:15718403

  3. γ-Aminobutyric acid (GABA) concentration inversely correlates with basal perfusion in human occipital lobe.

    PubMed

    Donahue, Manus J; Rane, Swati; Hussey, Erin; Mason, Emily; Pradhan, Subechhya; Waddell, Kevin W; Ally, Brandon A

    2014-03-01

    Commonly used neuroimaging approaches in humans exploit hemodynamic or metabolic indicators of brain function. However, fundamental gaps remain in our ability to relate such hemo-metabolic reactivity to neurotransmission, with recent reports providing paradoxical information regarding the relationship among basal perfusion, functional imaging contrast, and neurotransmission in awake humans. Here, sequential magnetic resonance spectroscopy (MRS) measurements of the primary inhibitory neurotransmitter, γ-aminobutyric acid (GABA+macromolecules normalized by the complex N-acetyl aspartate-N-acetyl aspartyl glutamic acid: [GABA(+)]/[NAA-NAAG]), and magnetic resonance imaging (MRI) measurements of perfusion, fractional gray-matter volume, and arterial arrival time (AAT) are recorded in human visual cortex from a controlled cohort of young adult male volunteers with neurocognitive battery-confirmed comparable cognitive capacity (3 T; n=16; age=23±3 years). Regression analyses reveal an inverse correlation between [GABA(+)]/[NAA-NAAG] and perfusion (R=-0.46; P=0.037), yet no relationship between AAT and [GABA(+)]/[NAA-NAAG] (R=-0.12; P=0.33). Perfusion measurements that do not control for AAT variations reveal reduced correlations between [GABA(+)]/[NAA-NAAG] and perfusion (R=-0.13; P=0.32). These findings largely reconcile contradictory reports between perfusion and inhibitory tone, and underscore the physiologic origins of the growing literature relating functional imaging signals, hemodynamics, and neurotransmission. PMID:24398941

  4. Subnormothermic Machine Perfusion for ex vivo Preservation and Recovery of the Human Liver for Transplantation

    PubMed Central

    Bruinsma, B.G.; Yeh, H.; Özer, S; Martins, P.N.; Farmer, A.; Wu, W.; Saeidi, N.; op den Dries, S.; Berendsen, T.A.; Smith, R.N.; Markmann, J.F.; Porte, R.; Yarmush, M.L.; Uygun, K.; Izamis, M.L.

    2015-01-01

    To reduce widespread shortages, attempts are made to use more marginal livers for transplantation. Many of these grafts are discarded for fear of inferior survival rates or biliary complications. Recent advances in organ preservation have shown that ex vivo subnormothermic machine perfusion has the potential to improve preservation and recover marginal livers pre- transplantation. To determine the feasibility in human livers, we assessed the effect of 3 hours of oxygenated subnormothermic machine perfusion (21 °C) on seven livers discarded for transplantation. Biochemical and microscopic assessment revealed minimal injury sustained during perfusion. Improved oxygen uptake (1.30 [1.11–1.94] to 6.74 [4.15–8.16] mL O2/min.kg liver), lactate levels (4.04 [3.70–6.00] to 2.29 [1.20–3.42] mmol/L) and adenosine triphosphate content (45.0 [70.6–87.5] pre-perfusion to 167.5 [151.5–237.2] pmol/mg after perfusion) were observed. Liver function, reflected by urea, albumin and bile production was seen during perfusion. Bile production increased and the composition of bile (bile salts/phospholipid ratio, pH and bicarbonate concentration) became more favorable. In conclusion, ex vivo subnormothermic machine perfusion effectively maintains liver function with minimal injury and sustains or improves various hepatobiliary parameters post-ischemia. PMID:24758155

  5. Leptin production and release in the dually in vitro perfused human placenta.

    PubMed

    Linnemann, K; Malek, A; Sager, R; Blum, W F; Schneider, H; Fusch, C

    2000-11-01

    There is clear evidence that the placenta produces leptin. However, it is still unclear to what extent leptin is released into the maternal and the fetal circulation. The aim of our study was to determine placental leptin release rates into these 2 compartments. In 10 term placentas, using dual in vitro perfusion of an isolated cotyledon, concentrations of leptin, hCG, and human placental lactogen (hPL) were determined in perfusates and in the tissue before and after perfusion. With perfusions lasting 270-840 min, total leptin production was 225 pg/g x min [median; interquartile range (IQR), 76-334 pg/g x min]. The release into the fetal circulation was very low (median, 2.5; IQR, 1.1-5.9 pg/g x min) compared with the release into the maternal circulation (median, 203; IQR, 79-373 pg/g x min) corresponding to 1.6% and 98.4% of net release. Only 0.05% of hPL and hCG were released into the fetal circulation and 99.95% into the maternal circulation, confirming previous results. Release into the fetal circulation correlated significantly with release into the maternal circulation for leptin (r = 0.648; P < 0.05) and hPL (r = 0.721; P < 0.05). Furthermore, release of leptin into the fetal circulation was positively correlated with release of fetal hCG (r = 0.661; P < 0.05). Most of the leptin produced by the placenta is released into the maternal circulation, but compared with other placental hormones (hCG and hPL), a considerably higher proportion of leptin is released into the fetal circulation. These findings may at least partially explain the marked increase in maternal serum leptin levels in pregnancy. The rapid postnatal decrease in leptin levels in both the mother and the neonate is also consistent with the concept of placental origin. PMID:11095471

  6. Contrast-enhanced diffuse optical tomography of brain perfusion in humans using ICG

    NASA Astrophysics Data System (ADS)

    Habermehl, Christina; Schmitz, Christoph; Steinbrink, Jens

    2012-02-01

    Regular monitoring of brain perfusion at the bedside in neurointensive care is desirable. Currently used imaging modalities are not suited for constant monitoring and often require a transport of the patient. Noninvasive near infrared spectroscopy (NIRS) in combination with an injection of a safe dye (indocyanine green, ICG) could serve as a quasi-continuous brain perfusion monitor. In this work, we evaluate prerequisites for the development of a brain perfusion monitor using continuous wave (cw) NIRS technique. We present results from a high-resolution diffuse optical tomography (HR-DOT) experiment in humans demonstrating the separation of signals from skin from the brain. This technique can help to monitor neurointensive care patients on a regular basis, detecting changes in cortical perfusion in time.

  7. Acetylcholine output and foetal vascular resistance of human perfused placental cotyleda.

    PubMed Central

    Boura, A. L.; Gude, N. M.; King, R. G.; Walters, W. A.

    1986-01-01

    The foetal villous vessels of single cotyleda of human placentae have been perfused with a constant flow of Krebs solution, recording inflow pressure and passing the venous perfusate in cascade over guinea-pig ileum and rat stomach strip preparations in vitro. Each cotyledon released for at least 4 h a substance that was probably acetylcholine. The perfusate caused contractions of both preparations which were inhibited by atropine or hyoscine and potentiated by physostigmine. Contractile activity was destroyed after incubation at 37 degrees C of perfusate with acetylcholinesterase but not with acetylcholinesterase plus physostigmine. When the perfusion temperature was lowered to 34 degrees C or below, acetylcholine output was reduced, the extent depending on the fall in temperature. No change in resistance of the villous vessels occurred during the changes in temperature or in the presence at 37 degrees C of atropine, hyoscine, hexamethonium, (+)-tubocurarine, hemicholinium-3 or bretylium. Submaximal vasoconstrictor responses of the villous vessels to the thromboxane A2-mimetic U46619 were not affected by reduction of the perfusion temperature to 30 degrees C, which lowered acetylcholine-like output by approximately 70%. Responses to U46619, at 37 degrees C, were unchanged during the presence of atropine or hyoscine. Acetylcholine is released into the foetal circulation of the human placenta but no evidence could be obtained that it affects villous vascular smooth muscle tone or vasoconstrictor responses. PMID:3730696

  8. Characteristics of human cell line, F2N78, for the production of recombinant antibody in fed-batch and perfusion cultures.

    PubMed

    Seo, Joon Serk; Min, Byung Sub; Kwon, Young-Bum; Lee, Soo-Young; Cho, Jong-Moon; Park, Keun-Hee; Yang, Yae Ji; Maeng, Ki Eun; Chang, Shin-Jae; Kim, Dong-Il

    2016-03-01

    A human hybrid cell line, F2N78, was developed by somatic fusion of HEK293 and Namalwa cells for the production recombinant biopharmaceutical proteins. In this study, we performed perfusion culture to verify its potential in culture process used for human cell expression platform. Cell viability could be maintained over 90% and high viable cell density was obtained at higher than 1.0 × 10(7) cells/mL by bleeding process in perfusion culture. The cells were adapted well in both culture modes, but there were apparent differences in protein quality. Compared to fed-batch culture, degalactosylated forms such as G0F and G0 as well as Man5 showed no significant increases in perfusion culture. In terms of charge variants, acidic peaks increased, whereas main peaks constantly decreased according to the length of culture period in both methods. PMID:26454770

  9. Physiological and biochemical markers of alveolar epithelial barrier dysfunction in perfused human lungs

    PubMed Central

    Frank, James A.; Briot, Raphael; Lee, Jae Woo; Ishizaka, Akitoshi; Uchida, Tokujiro; Matthay, Michael A.

    2009-01-01

    To study air space fluid clearance (AFC) under conditions that resemble the clinical setting of pulmonary edema in patients, we developed a new perfused human lung preparation. We measured AFC in 20 human lungs rejected for transplantation and determined the contribution of AFC to lung fluid balance. AFC was then compared with air space and perfusate levels of a biological marker of epithelial injury. The majority of human lungs rejected for transplant had intact basal (75%) and β2-adrenergic agonist-stimulated (70%) AFC. For lungs with both basal and stimulated AFC, the basal AFC rate was 19 ± 10%/h, and the β2-adrenergic-stimulated AFC rate was 43 ± 13%/h. Higher rates of AFC were associated with less lung weight gain (Pearson coefficient −0.90, P < 0.0001). Air space and perfusate levels of the type I pneumocyte marker receptor for advanced glycation end products (RAGE) were threefold and sixfold higher, respectively, in lungs without basal AFC compared with lungs with AFC (P < 0.05). These data show that preserved AFC is a critical determinant of favorable lung fluid balance in the perfused human lung, raising the possibility that β2-agonist therapy to increase edema fluid clearance may be of value for patients with acute lung injury and pulmonary edema. Also, although additional studies are needed, a biological marker of alveolar epithelial injury may be useful clinically in predicting preserved AFC. PMID:17351061

  10. Perfusion Stirred-Tank Bioreactors for 3D Differentiation of Human Neural Stem Cells.

    PubMed

    Simão, Daniel; Arez, Francisca; Terasso, Ana P; Pinto, Catarina; Sousa, Marcos F Q; Brito, Catarina; Alves, Paula M

    2016-01-01

    Therapeutic breakthroughs in neurological disorders have been hampered by the lack of accurate central nervous system (CNS) models. The development of these models allows the study of the disease onset/progression mechanisms and the preclinical evaluation of new therapeutics. This has traditionally relied on genetically engineered animal models that often diverge considerably from the human phenotype (developmental, anatomic, and physiological) and 2D in vitro cell models, which fail to recapitulate the characteristics of the target tissue (cell-cell and cell-matrix interactions, cell polarity, etc.). Recapitulation of CNS phenotypic and functional features in vitro requires the implementation of advanced culture strategies, such as 3D culture systems, which enable to mimic the in vivo structural and molecular complexity. Models based on differentiation of human neural stem cells (hNSC) in 3D cultures have great potential as complementary tools in preclinical research, bridging the gap between human clinical studies and animal models. The development of robust and scalable processes for the 3D differentiation of hNSC can improve the accuracy of early stage development in preclinical research. In this context, the use of software-controlled stirred-tank bioreactors (STB) provides an efficient technological platform for hNSC aggregation and differentiation. This system enables to monitor and control important physicochemical parameters for hNSC culture, such as dissolved oxygen. Importantly, the adoption of a perfusion operation mode allows a stable flow of nutrients and differentiation/neurotrophic factors, while clearing the toxic by-products. This contributes to a setting closer to the physiological, by mimicking the in vivo microenvironment. In this chapter, we address the technical requirements and procedures for the implementation of 3D differentiation strategies of hNSC, by operating STB under perfusion mode for long-term cultures. This strategy is suitable

  11. Metabolic profiling during ex vivo machine perfusion of the human liver

    PubMed Central

    Bruinsma, Bote G.; Sridharan, Gautham V.; Weeder, Pepijn D.; Avruch, James H.; Saeidi, Nima; Özer, Sinan; Geerts, Sharon; Porte, Robert J.; Heger, Michal; van Gulik, Thomas M.; Martins, Paulo N.; Markmann, James F.; Yeh, Heidi; Uygun, Korkut

    2016-01-01

    As donor organ shortages persist, functional machine perfusion is under investigation to improve preservation of the donor liver. The transplantation of donation after circulatory death (DCD) livers is limited by poor outcomes, but its application may be expanded by ex vivo repair and assessment of the organ before transplantation. Here we employed subnormothermic (21 °C) machine perfusion of discarded human livers combined with metabolomics to gain insight into metabolic recovery during machine perfusion. Improvements in energetic cofactors and redox shifts were observed, as well as reversal of ischemia-induced alterations in selected pathways, including lactate metabolism and increased TCA cycle intermediates. We next evaluated whether DCD livers with steatotic and severe ischemic injury could be discriminated from ‘transplantable’ DCD livers. Metabolomic profiling was able to cluster livers with similar metabolic patterns based on the degree of injury. Moreover, perfusion parameters combined with differences in metabolic factors suggest variable mechanisms that result in poor energy recovery in injured livers. We conclude that machine perfusion combined with metabolomics has significant potential as a clinical instrument for the assessment of preserved livers. PMID:26935866

  12. Metabolic profiling during ex vivo machine perfusion of the human liver.

    PubMed

    Bruinsma, Bote G; Sridharan, Gautham V; Weeder, Pepijn D; Avruch, James H; Saeidi, Nima; Özer, Sinan; Geerts, Sharon; Porte, Robert J; Heger, Michal; van Gulik, Thomas M; Martins, Paulo N; Markmann, James F; Yeh, Heidi; Uygun, Korkut

    2016-01-01

    As donor organ shortages persist, functional machine perfusion is under investigation to improve preservation of the donor liver. The transplantation of donation after circulatory death (DCD) livers is limited by poor outcomes, but its application may be expanded by ex vivo repair and assessment of the organ before transplantation. Here we employed subnormothermic (21 °C) machine perfusion of discarded human livers combined with metabolomics to gain insight into metabolic recovery during machine perfusion. Improvements in energetic cofactors and redox shifts were observed, as well as reversal of ischemia-induced alterations in selected pathways, including lactate metabolism and increased TCA cycle intermediates. We next evaluated whether DCD livers with steatotic and severe ischemic injury could be discriminated from 'transplantable' DCD livers. Metabolomic profiling was able to cluster livers with similar metabolic patterns based on the degree of injury. Moreover, perfusion parameters combined with differences in metabolic factors suggest variable mechanisms that result in poor energy recovery in injured livers. We conclude that machine perfusion combined with metabolomics has significant potential as a clinical instrument for the assessment of preserved livers. PMID:26935866

  13. Dielectric spectroscopy for monitoring human pancreatic islet differentiation within cell-seeded scaffolds in a perfusion bioreactor system.

    PubMed

    Daoud, J; Heileman, K; Shapka, S; Rosenberg, L; Tabrizian, M

    2015-09-21

    The long-term in vitro culture and differentiation of human pancreatic islets is still hindered by the inability to emulate a suitable microenvironment mimicking physiological extracellular matrix (ECM) support and nutrient/oxygen perfusion. This is further amplified by the current lack of a non-invasive and rapid monitoring system to readily evaluate cellular processes. In this study, we realized a viable method for non-invasively monitoring isolated human pancreatic islets in vitro. Islets are induced to dedifferentiate into proliferative duct-like structures (DLS) in preparation for potential and subsequent re-differentiation into functional islet-like structures (ILS) in a process reminiscent of islet regeneration strategies. This long-term in vitro process is conducted within a three-dimensional microenvironment involving islets embedded in an optimized ECM gel supported by microfabricated three-dimensional scaffolds. The islet-scaffold is then housed and continuously perfused within chambers of a bioreactor platform. The process in its entirety is monitored through dielectric spectroscopy measurements, yielding an accurate representation of cellular morphology, functionality, and volume fraction. This non-invasive and real-time monitoring tool can be further manipulated to elucidate important information about the optimized cellular microenvironment required for maintaining long-term culture and achieve efficient differentiation for islet regeneration. PMID:26280028

  14. The cerebral imaging using vessel-around method in the perfusion CT of the human brain

    NASA Astrophysics Data System (ADS)

    Ahn, Choong-Il; Choi, Seung-Wook; Park, Seung-Chul; Shin, Yeong-Gil; Kim, Jae-Hyoung; Chong, Gi-Bong

    2005-04-01

    Perfusion CT has been successfully used as a functional imaging technique for diagnosis of patients with hyperacute stroke. However, the commonly used methods based on curve-fitting are time consuming. Numerous researchers have investigated to what extent Perfusion CT can be used for the quantitative assessment of cerebral ischemia and to rapidly obtain comprehensive information regarding the extent of ischemic damage in acute stroke patients. The aim of this study is to propose an alternative approach to rapidly obtain the brain perfusion mapping and to show the proposed cerebral flow imaging of the vessel and tissue in human brain be reliable and useful. Our main design concern was algorithmic speed, robustness and automation in order to allow its potential use in the emergency situation of acute stroke. To obtain a more effective mapping, we analyzed the signal characteristics of Perfusion CT and defined the vessel-around model which includes the vessel and tissue. We proposed a nonparametric vessel-around approach which automatically discriminates the vessel and tissue around vessel from non-interested brain matter stratifying the level of maximum enhancement of pixel-based TAC. The stratification of pixel-based TAC was executed using the mean and standard deviation of the signal intensity of each pixel and mapped to the cerebral flow imaging. The defined vessel-around model was used to show the cerebral flow imaging and to specify the area of markedly reduced perfusion with loss of function of still viable neurons. Perfusion CT is a fast and practical technique for routine clinical application. It provides substantial and important additional information for the selection of the optimal treatment strategy for patients with hyperacute stroke. The vessel-around approach reduces the computation time significantly when compared with the perfusion imaging using the GVF. The proposed cerebral imaging shows reliable results which are validated by physicians and

  15. An Optical Oxygen Sensor for Long-Term Continuous Monitoring of Dissolved Oxygen in Perfused Bioreactors

    NASA Technical Reports Server (NTRS)

    Gao, F. G.; Jeevarajan, A. S.; Anderson, M. M.

    2002-01-01

    For long-term growth of man1ITlalian cells in perfused bioreactors, it is essential to monitor the concentration of dissolved oxygen (DO) present in the culture medium to quantitate and control level of DO. Continuous measurement of the amount of DO in the cell culture medium in-line under sterile conditions in NASA's perfused bioreactor requires that the oxygen sensor provide increased sensitivity and be sterilizable and nontoxic. Additionally, long-term cell culture experiments require that the calibration be maintained several weeks or months. Although there are a number of sensors for dissolved oxygen on the market and under development elsewhere, very few meet these stringent conditions. An optical oxygen sensor (BOXY) based on dynamic fluorescent quenching and a pulsed blue LED light source was developed in our laboratory to address these requirements. Tris( 4,7 -diphenyl-l, 1 O-phenanthroline )ruthenium(II) chloride is employed as the fluorescent dye indicator. The sensing element consists of a glass capillary (OD 4.0 mm; ID 2.0 mm) coated internally with a thin layer of the fluorescent dye in silicone matrix and overlayed with a black shielding layer. Irradiation of the sensing element with blue light (blue LED with emission maximum at 475 nm) generates a red fluorescence centered at 626 nm. The fluorescence intensity is correlated to the concentration of DO present in the culture medium, following the modified non-linear Stern-Volmer equation. By using a pulsed irradiating light source, the problem of dye-bleaching, which is often encountered in long-term continuous measurements of tIns type, 'is minimized. To date we achieved sensor resolution of 0.3 mmHg at 50 mmHg p02, and 0.6 mmHg at 100 mmHg p02, with a response time of about one minute. Calibration was accomplished in sterile phosphate-buffered saline with a blood-gas analyzer (BGA) measurement as reference. Stand-alone software was also developed to control the sensor and bioreactor as well as to

  16. Direct In Vivo Human Intestinal Permeability (Peff ) Determined with Different Clinical Perfusion and Intubation Methods.

    PubMed

    Dahlgren, David; Roos, Carl; Sjögren, Erik; Lennernäs, Hans

    2015-09-01

    Regional in vivo human intestinal effective permeability (Peff ) is calculated by measuring the disappearance rate of substances during intestinal perfusion. Peff is the most relevant parameter in the prediction of rate and extent of drug absorption from all parts of the intestine. Today, human intestinal perfusions are not performed on a routine basis in drug development. Therefore, it would be beneficial to increase the accuracy of the in vitro and in silico tools used to evaluate the intestinal Peff of novel drugs. This review compiles historical Peff data from 273 individual measurements of 80 substances from 61 studies performed in all parts of the human intestinal tract. These substances include: drugs, monosaccharaides, amino acids, dipeptides, vitamins, steroids, bile acids, ions, fatty acids, and water. The review also discusses the determination and prediction of Peff using in vitro and in silico methods such as quantitative structure-activity relationship, Caco-2, Ussing chamber, animal intestinal perfusion, and physiologically based pharmacokinetic (PBPK) modeling. Finally, we briefly outline how to acquire accurate human intestinal Peff data by deconvolution of plasma concentration-time profiles following regional intestinal bolus dosing. PMID:25410736

  17. Human placental perfusion method in the assessment of transplacental passage of antiepileptic drugs

    SciTech Connect

    Myllynen, Paeivi . E-mail: paivi.k.myllynen@oulu.fi; Pienimaeki, Paeivi; Vaehaekangas, Kirsi

    2005-09-01

    Epilepsy is one of the most common neurological diseases, affecting about 0.5 to 1% of pregnant women. It is commonly accepted that older antiepileptic drugs bear teratogenic potential. So far, no agreement has been reached about the safest antiepileptic drug during pregnancy. It is known that nearly all drugs cross the placenta at least to some extent. Nowadays, there is very little information available of the pharmacokinetics of drugs in the feto-placental unit. Detailed information about drug transport across the placenta would be valuable for the development of safe and effective treatments. For reasons of safety, human studies on placental transfer are restricted to a limited number of drugs. Interspecies differences limit the extrapolation of animal data to humans. Several in vitro methods for the study of placental transfer have been developed over the past decades. The placental perfusion method is the only experimental method that has been used to study human placental transfer of substances in organized placental tissue. The aim of this article is to review human placental perfusion data on antiepileptic drugs. According to perfusion data, it seems that most of the antiepileptic drugs are transferred across the placenta meaning significant fetal exposure.

  18. Bioreactor perfusion system for the long-term maintenance of tissue-engineered skeletal muscle organoids

    NASA Technical Reports Server (NTRS)

    Chromiak, J. A.; Shansky, J.; Perrone, C.; Vandenburgh, H. H.

    1998-01-01

    Three-dimensional skeletal muscle organ-like structures (organoids) formed in tissue culture by fusion of proliferating myoblasts into parallel networks of long, unbranched myofibers provide an in vivo-like model for examining the effects of growth factors, tension, and space flight on muscle cell growth and metabolism. To determine the feasibility of maintaining either avian or mammalian muscle organoids in a commercial perfusion bioreactor system, we measured metabolism, protein turnover. and autocrine/paracrine growth factor release rates. Medium glucose was metabolized at a constant rate in both low-serum- and serum-free media for up to 30 d. Total organoid noncollagenous protein and DNA content decreased approximately 22-28% (P < 0.05) over a 13-d period. Total protein synthesis rates could be determined accurately in the bioreactors for up to 30 h and total protein degradation rates could be measured for up to 3 wk. Special fixation and storage conditions necessary for space flight studies were validated as part of the studies. For example, the anabolic autocrine/paracrine skeletal muscle growth factors prostaglandin F2alpha (PGF2alpha) and insulin-like growth factor-1 (IGF-1) could be measured accurately in collected media fractions, even after storage at 37 degrees C for up to 10 d. In contrast, creatine kinase activity (a marker of cell damage) in collected media fractions was unreliable. These results provide initial benchmarks for long-term ex vivo studies of tissue-engineered skeletal muscle.

  19. Electromechanical activities of human uteri during extra-corporeal perfusion with ovarian steroids.

    PubMed

    Bulletti, C; Prefetto, R A; Bazzocchi, G; Romero, R; Mimmi, P; Polli, V; Lanfranchi, G A; Labate, A M; Flamigni, C

    1993-10-01

    A new experimental system was designed to study human uterine activities based on the extra-corporeal perfusion of isolated human uteri. Electromechanical activities in the uterine wall were recorded using bipolar silver-silver electrodes, endoluminal pressure catheters and a dedicated acquisition, storage and analytical system. The electrical signals recorded were isolated spikes and rhythmic activities; the last being primarily associated with organized mechanical events. Perfusion media containing 17 beta-oestradiol alone or with progesterone were used for those uteri obtained during proliferative (n = 5) or secretory (n = 5) phases of the menstrual cycle, respectively. Progesterone caused a reduction of frequency (P < 0.001) and duration (P < 0.001) of the rhythmic electrical activity, and decreased the endoluminal pressure at both detection sites (P < 0.01). 17 beta-Oestradiol increased both frequency (P < 0.001) and duration (P < 0.001) of the rhythmic electrical activity as well as the endoluminal pressure at two different detection sites (3 and 5 cm from the fundus) (P < 0.05). Significant differences between the fundus and cervix sites in the uterine wall were detected. In conclusion, uterine perfusion would be useful to examine the effects of uterotonic and tocolytic drugs before administration to humans, at no risk to the patients. Oestrogens increase and progesterone decreases both electrical and mechanical uterine activities. PMID:8300807

  20. Matching of postcontraction perfusion to oxygen consumption across submaximal contraction intensities in exercising humans

    PubMed Central

    Elder, Christopher P.; Donahue, Manus J.; Damon, Bruce M.

    2015-01-01

    Studying the magnitude and kinetics of blood flow, oxygen extraction, and oxygen consumption at exercise onset and during the recovery from exercise can lead to insights into both the normal control of metabolism and blood flow and the disturbances to these processes in metabolic and cardiovascular diseases. The purpose of this study was to examine the on- and off-kinetics for oxygen delivery, extraction, and consumption as functions of submaximal contraction intensity. Eight healthy subjects performed four 1-min isometric dorsiflexion contractions, with two at 20% MVC and two at 40% MVC. During one contraction at each intensity, relative perfusion changes were measured by using arterial spin labeling, and the deoxyhemoglobin percentage (%HHb) was estimated using the spin- and gradient-echo sequence and a previously published empirical calibration. For the whole group, the mean perfusion did not increase during contraction. The %HHb increased from ∼28 to 38% during contractions of each intensity, with kinetics well described by an exponential function and mean response times (MRTs) of 22.7 and 21.6 s for 20 and 40% MVC, respectively. Following contraction, perfusion increased ∼2.5-fold. The %HHb, oxygen consumption, and perfusion returned to precontraction levels with MRTs of 27.5, 46.4, and 50.0 s, respectively (20% MVC), and 29.2, 75.3, and 86.0 s, respectively (40% MVC). These data demonstrate in human subjects the varied recovery rates of perfusion and oxygen consumption, along with the similar rates of %HHb recovery, across these exercise intensities. PMID:26066829

  1. Engineering a perfusable 3D human liver platform from iPS cells.

    PubMed

    Schepers, Arnout; Li, Cheri; Chhabra, Arnav; Seney, Benjamin Tschudy; Bhatia, Sangeeta

    2016-07-01

    In vitro models of human tissue are crucial to our ability to study human disease as well as develop safe and effective drug therapies. Models of single organs in static and microfluidic culture have been established and shown utility for modeling some aspects of health and disease; however, these systems lack multi-organ interactions that are critical to some aspects of drug metabolism and toxicity. Thus, as part of a consortium of researchers, we have developed a liver chip that meets the following criteria: (1) employs human iPS cells from a patient of interest, (2) cultures cells in perfusable 3D organoids, and (3) is robust to variations in perfusion rate so as to be compatible in series with other specialized tissue chips (e.g. heart, lung). In order to achieve this, we describe methods to form hepatocyte aggregates from primary and iPS-derived cells, alone and in co-culture with support cells. This necessitated a novel culture protocol for the interrupted differentiation of iPS cells that permits their removal from a plated surface and aggregation while maintaining phenotypic hepatic functions. In order to incorporate these 3D aggregates in a perfusable platform, we next encapsulated the cells in a PEG hydrogel to prevent aggregation and overgrowth once on chip. We adapted a C-trap chip architecture from the literature that enabled robust loading with encapsulated organoids and culture over a range of flow rates. Finally, we characterize the liver functions of this iHep organoid chip under perfusion and demonstrate a lifetime of at least 28 days. We envision that such this strategy can be generalized to other microfluidic tissue models and provides an opportunity to query patient-specific liver responses in vitro. PMID:27296616

  2. Cultivation of Human Bone-Like Tissue from Pluripotent Stem Cell-Derived Osteogenic Progenitors in Perfusion Bioreactors

    PubMed Central

    de Peppo, Giuseppe Maria; Vunjak-Novakovic, Gordana; Marolt, Darja

    2014-01-01

    Human pluripotent stem cells represent an unlimited source of skeletal tissue progenitors for studies of bone biology, pathogenesis, and the development of new approaches for bone reconstruction and therapies. In order to construct in vitro models of bone tissue development and to grow functional, clinical-size bone substitutes for transplantation, cell cultivation in three-dimensional environments composed of porous osteoconductive scaffolds and dynamic culture systems—bioreactors—has been studied. Here, we describe a stepwise procedure for the induction of human embryonic and induced pluripotent stem cells (collectively termed PSCs) into mesenchymal-like progenitors, and their subsequent cultivation on decellularized bovine bone scaffolds in perfusion bioreactors, to support the development of viable, stable bone-like tissue in defined geometries. PMID:24281874

  3. Ectopic Osteogenesis of Macroscopic Tissue Constructs Assembled from Human Mesenchymal Stem Cell-Laden Microcarriers through In Vitro Perfusion Culture

    PubMed Central

    Chen, Maiqin; Zhou, Min; Ye, Zhaoyang; Zhou, Yan; Tan, Wen-Song

    2014-01-01

    We had previously demonstrated the feasibility of preparing a centimeter-sized bone tissue construct by following a modular approach. In the present study, the objectives were to evaluate osteogenesis and tissue formation of human amniotic mesenchymal stem cells-laden CultiSpher S microcarriers during in vitro perfusion culture and after subcutaneous implantation. Microtissues were prepared in dynamic culture using spinner flasks in 28 days. In comparison with 1-week perfusion culture, microtissues became more obviously fused, demonstrating significantly higher cellularity, metabolic activity, ALP activity and calcium content while maintaining cell viability after 2-week perfusion. After subcutaneous implantation in nude mice for 6 and 12 weeks, all explants showed tight contexture, suggesting profound tissue remodeling in vivo. In addition, 12-week implantation resulted in slightly better tissue properties. However, in vitro perfusion culture time exerted great influence on the properties of corresponding explants. Degradation of microcarriers was more pronounced in the explants of 2-week perfused macrotissues compared to those of 1-week perfusion and directly implanted microtissues. Moreover, more blood vessel infiltration and bone matrix deposition with homogeneous spatial distribution were found in the explants of 2-week perfused macrotissues. Taken together, in vitro perfusion culture time is critical in engineering bone tissue replacements using such a modular approach, which holds great promise for bone regeneration. PMID:25275528

  4. Atrasentan (ABT-627) enhances perfusion and reduces hypoxia in a human tumor xenograft model

    PubMed Central

    Yang, Kwang Mo; Russell, James; Lupu, Mihaela E.; Cho, HyungJoon; Li, Xiao-Feng; Koutcher, Jason A.; Ling, C. Clifton

    2010-01-01

    The endothelin-1 antagonist, Atrasentan (ABT-627) was used to modify perfusion in the human tumor xenograft model, HT29, growing in nude mice. Atrasentan produced a significant increase in perfusion, as measured in vivo by Gd-DTPA DCE-MRI. Changes in tumor hypoxia were assessed by comparing the binding of two hypoxia tracers, pimonidazole and EF5 given before and after Atrasentan administration. In vehicle-treated controls, the distribution of EF5 and pimonidazole was very similar. However, Atrasentan treatment was associated with decreased uptake of the second hypoxia tracer (EF5), relative to the first (pimonidazole). Although Atrasentan had no independent effect on the growth of HT29 tumors, Atrasentan combined with 20 Gy radiation led to a modest but significant increase in tumor growth delay compared to radiation alone. PMID:19717985

  5. Induction of Hepatic and Endothelial Differentiation by Perfusion in a Three-Dimensional Cell Culture Model of Human Fetal Liver

    PubMed Central

    Pekor, Christopher; Gerlach, Jörg C.; Nettleship, Ian

    2015-01-01

    The development of functional engineered tissue constructs depends on high cell densities and appropriate vascularization. In this study we implemented a four-compartment three-dimensional perfusion bioreactor culture model for studying the effects of medium perfusion on endothelial, hepatic, and hematopoietic cell populations of primary human fetal liver in an in vivo-like environment. Human fetal liver cells were cultured in bioreactors configured to provide either perfusion or diffusion conditions. Metabolic activities of the cultures were monitored daily by measuring glucose consumption and lactate production. Cell viability during culture was analyzed by lactate dehydrogenase activity. Hepatic functionality was determined by the release of albumin and alpha-fetoprotein (AFP) in culture medium samples. After 4 days of culture, cells were analyzed for the expression of a variety of endothelial, hepatic, and hematopoietic genes, as well as the surface marker expression of CD31 and CD34 in flow cytometry. We found that medium perfusion increased the gene expression of endothelial markers such as CD31, von Willebrand factor (vWF), CD140b, CD309, and CD144 while decreasing the gene expression of the erythrocyte-surface marker CD235a. Hepatic differentiation was promoted under perfusion conditions as demonstrated by lower AFP and higher albumin secretion compared with cultures not exposed to medium perfusion. Additionally, cultures exposed to medium perfusion gave higher rates of glucose consumption and lactate production, indicating increased metabolic activity. In conclusion, high-density bioreactors configured to provide constant medium perfusion significantly induced hepatic and endothelial cell differentiation and provided improved conditions for the culture of human fetal liver cells compared with cultures without perfusion. PMID:25559936

  6. Induction of Hepatic and Endothelial Differentiation by Perfusion in a Three-Dimensional Cell Culture Model of Human Fetal Liver.

    PubMed

    Pekor, Christopher; Gerlach, Jörg C; Nettleship, Ian; Schmelzer, Eva

    2015-07-01

    The development of functional engineered tissue constructs depends on high cell densities and appropriate vascularization. In this study we implemented a four-compartment three-dimensional perfusion bioreactor culture model for studying the effects of medium perfusion on endothelial, hepatic, and hematopoietic cell populations of primary human fetal liver in an in vivo-like environment. Human fetal liver cells were cultured in bioreactors configured to provide either perfusion or diffusion conditions. Metabolic activities of the cultures were monitored daily by measuring glucose consumption and lactate production. Cell viability during culture was analyzed by lactate dehydrogenase activity. Hepatic functionality was determined by the release of albumin and alpha-fetoprotein (AFP) in culture medium samples. After 4 days of culture, cells were analyzed for the expression of a variety of endothelial, hepatic, and hematopoietic genes, as well as the surface marker expression of CD31 and CD34 in flow cytometry. We found that medium perfusion increased the gene expression of endothelial markers such as CD31, von Willebrand factor (vWF), CD140b, CD309, and CD144 while decreasing the gene expression of the erythrocyte-surface marker CD235a. Hepatic differentiation was promoted under perfusion conditions as demonstrated by lower AFP and higher albumin secretion compared with cultures not exposed to medium perfusion. Additionally, cultures exposed to medium perfusion gave higher rates of glucose consumption and lactate production, indicating increased metabolic activity. In conclusion, high-density bioreactors configured to provide constant medium perfusion significantly induced hepatic and endothelial cell differentiation and provided improved conditions for the culture of human fetal liver cells compared with cultures without perfusion. PMID:25559936

  7. Active skin perfusion and thermoregulatory response in the hand following nerve injury and repair in human upper extremities.

    PubMed

    Deng, Aidong; Liu, Dan; Gu, Chen; Gu, Xiaosong; Gu, Jianhui; Hu, Wen

    2016-01-01

    Cutaneous vasoconstriction/vasodilatation occurs in response to whole body and local cooling/heating, and the vasomotor activities play a pivotal role in thermal control of the human body. The mechanisms underlying regulation of skin blood flow involve both neurogenic and humeral/local chemical influence, contributing to the initial response to thermal stimuli and the prolonged phase of response, respectively. Previous studies have suggested the impairment of cutaneous thermal regulation after nerve injury. However, the evidence regarding how the skin perfusion and thermoregulatory response evolve after nerve injury and repair remains limited. Here we observed, by utilizing laser-Doppler perfusion imaging, baseline skin perfusion and perfusion change in response to thermal stimuli after median and ulnar nerve injury, and the results showed that baseline perfusion in autonomous skin area profoundly decreased and active rewarming after clod stress dramatically diminished before sensory recovery of the skin became detectable. In addition, baseline cutaneous perfusion was recovered as the skin regained touch sensation, and exhibited positive correlation to touch sensibility of the skin. These data indicate that both active perfusion and thermoregulatory response of the skin are markedly compromised during skin denervation and can be recovered by re-innervation. This suggests the importance of timely repair of injured nerve, especially in the practice of replantation. PMID:26529641

  8. Intravital lectin perfusion analysis of vascular permeability in human micro- and macro- blood vessels.

    PubMed

    Debbage, P L; Sölder, E; Seidl, S; Hutzler, P; Hugl, B; Ofner, D; Kreczy, A

    2001-10-01

    We previously applied intravital lectin perfusion in mouse models to elucidate mechanisms underlying vascular permeability. The present work transfers this technique to human models, analysing vascular permeability in macro- and microvessels. Human vascular endothelial surface carbohydrate biochemistry differs significantly from its murine counterpart, lacking alpha-galactosyl epitopes and expressing the L-fucose moiety in the glycocalyx; the poly-N-lactosamine glycan backbone is common to all mammals. We examined extensively lectin binding specificities in sections and in vivo, and then applied the poly-N-lactosamine-specific lectin LEA and the L-fucose-specific lectin UEA-I in human intravital perfusions. Transendothelial transport differed in macrovessels and microvessels. In microvessels of adult human fat tissue, rectal wall and rectal carcinomas, slow transendothelial transport by vesicles was followed by significant retention at the subendothelial basement membrane; paracellular passage was not observed. Passage time exceeded 1 h. Thus we found barrier mechanisms resembling those we described previously in murine tissues. In both adult and fetal macrovessels, the vena saphena magna and the umbilical vein, respectively, rapid passage across the endothelial lining was observed, the tracer localising completely in the subendothelial tissues within 15 min; vesicular transport was more rapid than in microvessels, and retention at the subendothelial basement membrane briefer. PMID:11702193

  9. Long-term outdoor cultivation by perfusing spent medium for biodiesel production from Chlorella minutissima.

    PubMed

    Oh, Sung Ho; Kwon, Min Chul; Choi, Woon Yong; Seo, Yong Chang; Kim, Ga Bin; Kang, Do Hyung; Lee, Shin Young; Lee, Hyeon Yong

    2010-08-01

    A unique perfusion process was developed to maintain high concentrations of marine alga, Chlorella minutissima. This method is based on recycling cells by continuous feeding with warm spent sea water from nuclear power plants, which has very similar properties as sea water. A temperature of at least 30 degrees C in a 200 L photo-bioreactor was maintained in this system by perfusion of the thermal plume for 80 days in the coldest season. The maximum cell concentration and total lipid content was 8.3 g-dry wt./L and 23.2 %, w/w, respectively, under mixotrophic conditions. Lipid production was found to be due to a partially or non-growth related process, which implies that large amounts of biomass are needed for a high accumulation of lipids within the cells. At perfusion rates greater than 1.5 L/h, the temperature of the medium inside the reactor was around 30 degrees C, which was optimal for cell growth. For this system, a perfusion rate of 2.8 L/h was determined to be optimal for maintaining rapid cell growth and lipid production during outdoor cultivation. It was absolutely necessary to maintain the appropriate perfusion rate so that the medium temperature was optimal for cell growth. In addition, the lipids produced using this process were shown to be feasible for biodiesel production since the lipid composition of C. minutissima grown under these conditions consisted of 17 % (w/w) of C(16) and 47% (w/w) of C(18). The combined results of this study clearly demonstrated that the discharged energy of the thermal plume could be reused to cultivate marine alga by maintaining a relatively constant temperature in an outdoor photo-bioreactor without the need for supplying any extra energy, which could allow for cheap production of biodiesel from waste energy. PMID:20547326

  10. In vitro specular microscope perfusion of M-K- and moist chamber-stored human corneas.

    PubMed

    McCarey, B E

    1977-08-01

    Human donor corneas were stored in McCarey-Kaufman (M-K) medium for 3 to 6 days; then they were mounted in the specular microscope, and the endothelial surface perfused with a glutathione-bicarbonate-Ringer solution. During storage, the corneal thickness increased 37% above an assumed normal of 0.520 mm. The corneas did not have sufficient active thinning to be accepted as viable when tested by the temperature-reversal phenomenon. Since comparable donor corneas have been used in successful penetrating keratoplasties, there must be a discrepancy between the cell viability as tested by the temperature-reversal phenomenon and clinical application. PMID:328445

  11. In vivo confocal Raman spectroscopy study of the vitamin A derivative perfusion through human skin

    NASA Astrophysics Data System (ADS)

    dos Santos, Laurita; Téllez Soto, Claudio A.; Favero, Priscila P.; Martin, Airton A.

    2016-03-01

    In vivo confocal Raman spectroscopy is a powerful non-invasive technique able to analyse the skin constituents. This technique was applied to transdermal perfusion studies of the vitamin A derivative in human skin. The composition of the stratum corneum (lipid bilayer) is decisive for the affinity and transport of the vitamin through skin. The vitamin A is significantly absorbed by human skin when applied with water in oil emulsion or hydro-alcoholic gel. The purpose of this study is to elucidate the behaviour of vitamin A derivative into human skin without the presence of enhancers. The results showed that the intensity band of the derivative (around 1600 cm-1), which represents the -C=O vibrational mode, was detected in different stratum corneum depths (up to 20 μm). This Raman peak of vitamin A derivative has non-coincident band with the Raman spectra of the skin epidermis, demonstrating that compound penetrated in forearm skin.

  12. Vascular perfused segments of human intestine as a tool for drug absorption.

    PubMed

    Wei, Yansheng; Neves, Liomar A A; Franklin, Tammy; Klyuchnikova, Nadya; Placzek, Benjamin; Hughes, Helen M; Curtis, C Gerald

    2009-04-01

    Blood-based vascular perfusion of isolated segments of human jejunum was developed as a tool for drug absorption studies before clinical trials. Acceptance criteria for viable human gut preparations included stable blood flow, arterial pressure, glucose utilization, active peristalsis, oxygen uptake, less than 3% absorption of a 70,000 mol. wt. dextran, and a ratio of first-order absorption rate constants (k(a)) of antipyrine to terbutaline of > or =1.4. Mannitol absorption was less than that of antipyrine but larger than that of terbutaline and could not be used as a negative control in absorption studies with human intestine. In separate perfusions (n = 3) a cassette of nine drugs was administered into the gut lumen, and the net absorption of each drug into the circulation was measured over 75 min. Using the mean values of k(a), the test compounds could be ranked into four groups: group 1: sulfasalazine and furosemide, k(a) = 3.9 to 4.0 x 10(-3) min(-1); group 2: cimetidine, timolol, nadolol, and ranitidine, k(a) = 6.4 to 8.3 x 10(-3) min(-1); group 3: atenolol and metoprolol, k(a) = 9.6 x 10(-3) min(-1); and group 4: theophylline, k(a) = 17.5 x 10(-3) min(-1). The rationale for evaluating yet another oral absorption system was as follows: first, a human gut segment with an intact vascular system is the closest system available to a clinical trial without performing one; and second, the data generated would be a direct measure of net drug transport from the gut lumen into the vascular circulation under near physiological conditions, which is not possible in models lacking a blood supply. PMID:19118133

  13. Mechanisms of alphafetoprotein transfer in the perfused human placental cotyledon from uncomplicated pregnancy.

    PubMed Central

    Brownbill, P; Edwards, D; Jones, C; Mahendran, D; Owen, D; Sibley, C; Johnson, R; Swanson, P; Nelson, D M

    1995-01-01

    We investigated the mechanisms of alphafetoprotein (AFP) transfer across the human placenta by correlating measurements of AFP transfer with cytochemical localization of AFP. Placental cotyledons were dually perfused in vitro with either the fetal or maternal perfusate containing umbilical cord plasma as a source of AFP. Steady state AFP clearance, corrected for release of endogenous AFP, was 0.973 +/- 0.292 microliter/min per gram in the fetal to maternal direction (n = 10), significantly higher (P < 0.02) than that in the maternal to fetal direction (n = 5; 0.022 +/- 0.013 microliter/min per gram). Clearance of a similarly sized protein, horseradish peroxidase was also asymmetric but clearance of the small tracer creatinine was not. Using a monoclonal antibody, we localized AFP to fibrinoid deposits in regions of villi with discontinuities of the syncytiotrophoblast, to cytotrophoblast cells in these deposits, to syncytiotrophoblast on some villi, and to trophoblast cells in the decidua. We conclude that AFP transfer in the placenta is asymmetric and that there are two available pathways for AFP transfer: (a) from the fetal circulation into the villous core and across fibrinoid deposits at discontinuities in the villous syncytiotrophoblast to enter the maternal circulation; and (b) AFP present in the decidua could enter vessels that traverse the basal plate. Images PMID:7593608

  14. Placental Transfer of Maraviroc in an Ex Vivo Human Cotyledon Perfusion Model and Influence of ABC Transporter Expression

    PubMed Central

    Vinot, C.; Gavard, L.; Tréluyer, J. M.; Manceau, S.; Courbon, E.; Scherrmann, J. M.; Declèves, X.; Duro, D.; Peytavin, G.; Mandelbrot, L.

    2013-01-01

    Nowadays, antiretroviral therapy is recommended during pregnancy to prevent mother-to-child transmission of HIV. However, for many antiretroviral drugs, including maraviroc, a CCR5 antagonist, very little data exist regarding placental transfer. Besides, various factors may modulate this transfer, including efflux transporters belonging to the ATP-binding cassette (ABC) transporter superfamily. We investigated maraviroc placental transfer and the influence of ABC transporter expression on this transfer using the human cotyledon perfusion model. Term placentas were perfused ex vivo for 90 min with maraviroc (600 ng/ml) either in the maternal-to-fetal (n = 10 placentas) or fetal-to-maternal (n = 6 placentas) direction. Plasma concentrations were determined by ultra performance liquid chromatography coupled with tandem mass spectrometry (UPLC-MS/MS). Fetal transfer rates (FTR) and clearance indexes (CLI) were calculated as ratios of fetal to maternal concentrations at steady state (mean values between 30 and 90 min) and ratios of FTR of maraviroc to that of antipyrine, respectively. ABC transporter gene expression levels were determined by quantitative reverse transcription (RT)-PCR and ABCB1 protein expression by Western blotting. For the maternal-to-fetal direction, the mean FTR and CLI were 8.0% ± 3.0 and 0.26 ± 0.07, respectively, whereas the mean CLI was 0.52 ± 0.23 for the fetal-to-maternal direction. We showed a significant inverse correlation between maraviroc CLI and ABCC2, ABCC10, and ABCC11 placental gene expression levels (P < 0.05). To conclude, we report a low maraviroc placental transfer probably involving ABC efflux transporters and thus in all likelihood associated with a limited fetal exposition. Nevertheless, these results would need to be supported by in vivo data obtained from paired maternal and cord blood samples. PMID:23295922

  15. Cardiovascular responses to water immersion in humans: impact on cerebral perfusion

    PubMed Central

    Spence, Angela L.; Pugh, Christopher J. A.; Ainslie, Philip; Naylor, Louise H.; Green, Daniel J.

    2014-01-01

    Episodic increases in cerebrovascular perfusion and shear stress may have beneficial impacts on endothelial function that improve brain health. We hypothesized that water immersion to the level of the right atrium in humans would increase cerebral perfusion. We continuously measured, in 9 young (means ± SD, 24.6 ± 2.0 yr) healthy men, systemic hemodynamic variables along with blood flows in the common carotid and middle and posterior cerebral arteries during controlled filling and emptying of a water tank to the level of the right atrium. Mean arterial pressure (80 ± 9 vs. 91 ± 12 mmHg, P < 0.05), cardiac output (4.8 ± 0.7 vs. 5.1 ± 0.6 l/min, P < 0.05) and end-tidal carbon dioxide (PetCO2, 39.5 ± 2.0 vs. 44.4 ± 3.5 mmHg, P < 0.05) increased with water immersion, along with middle (59 ± 6 vs. 64 ± 6 cm/s, P < 0.05) and posterior cerebral artery blood flow velocities (41 ± 9 vs. 44 ± 10 cm/s, P < 0.05). These changes were reversed when the tank was emptied. Water immersion is associated with hemodynamic and PetCO2 changes, which increase cerebral blood velocities in humans. This study provides an evidence base for future studies to examine the potential additive effect of exercise in water on improving cerebrovascular health. PMID:24553298

  16. Phenylalanine transfer across the isolated perfused human placenta: an experimental and modeling investigation

    PubMed Central

    Lofthouse, E. M.; Perazzolo, S.; Brooks, S.; Crocker, I. P.; Glazier, J. D.; Johnstone, E. D.; Panitchob, N.; Sibley, C. P.; Widdows, K. L.; Sengers, B. G.

    2015-01-01

    Membrane transporters are considered essential for placental amino acid transfer, but the contribution of other factors, such as blood flow and metabolism, is poorly defined. In this study we combine experimental and modeling approaches to understand the determinants of [14C]phenylalanine transfer across the isolated perfused human placenta. Transfer of [14C]phenylalanine across the isolated perfused human placenta was determined at different maternal and fetal flow rates. Maternal flow rate was set at 10, 14, and 18 ml/min for 1 h each. At each maternal flow rate, fetal flow rates were set at 3, 6, and 9 ml/min for 20 min each. Appearance of [14C]phenylalanine was measured in the maternal and fetal venous exudates. Computational modeling of phenylalanine transfer was undertaken to allow comparison of the experimental data with predicted phenylalanine uptake and transfer under different initial assumptions. Placental uptake (mol/min) of [14C]phenylalanine increased with maternal, but not fetal, flow. Delivery (mol/min) of [14C]phenylalanine to the fetal circulation was not associated with fetal or maternal flow. The absence of a relationship between placental phenylalanine uptake and net flux of phenylalanine to the fetal circulation suggests that factors other than flow or transporter-mediated uptake are important determinants of phenylalanine transfer. These observations could be explained by tight regulation of free amino acid levels within the placenta or properties of the facilitated transporters mediating phenylalanine transport. We suggest that amino acid metabolism, primarily incorporation into protein, is controlling free amino acid levels and, thus, placental transfer. PMID:26676251

  17. Changes in transmural distribution of myocardial perfusion assessed by quantitative intravenous myocardial contrast echocardiography in humans

    PubMed Central

    Fukuda, S; Muro, T; Hozumi, T; Watanabe, H; Shimada, K; Yoshiyama, M; Takeuchi, K; Yoshikawa, J

    2002-01-01

    Objective: To clarify whether changes in transmural distribution of myocardial perfusion under significant coronary artery stenosis can be assessed by quantitative intravenous myocardial contrast echocardiography (MCE) in humans. Methods: 31 patients underwent dipyridamole stress MCE and quantitative coronary angiography. Intravenous MCE was performed by continuous infusion of Levovist. Images were obtained from the apical four chamber view with alternating pulsing intervals both at rest and after dipyridamole infusion. Images were analysed offline by placing regions of interest over both endocardial and epicardial sides of the mid-septum. The background subtracted intensity versus pulsing interval plots were fitted to an exponential function, y = A (1 − e−βt), where A is plateau level and β is rate of rise. Results: Of the 31 patients, 16 had significant stenosis (> 70%) in the left anterior descending artery (group A) and 15 did not (group B). At rest, there were no differences in the A endocardial to epicardial ratio (A-EER) and β-EER between the two groups (mean (SD) 1.2 (0.6) v 1.2 (0.8) and 1.2 (0.7) v 1.1 (0.6), respectively, NS). During hyperaemia, β-EER in group A was significantly lower than that in group B (1.0 (0.5) v 1.4 (0.5), p < 0.05) and A-EER did not differ between the two groups (1.0 (0.5) v 1.2 (0.4), NS). Conclusions: Changes in transmural distribution of myocardial perfusion under significant coronary artery stenosis can be assessed by quantitative intravenous MCE in humans. PMID:12231594

  18. Comparison of lung preservation solutions in human lungs using an ex vivo lung perfusion experimental model

    PubMed Central

    Medeiros, Israel L.; Pêgo-Fernandes, Paulo M.; Mariani, Alessandro W.; Fernandes, Flávio G.; Unterpertinger, Fernando V.; Canzian, Mauro; Jatene, Fabio B.

    2012-01-01

    OBJECTIVE: Experimental studies on lung preservation have always been performed using animal models. We present ex vivo lung perfusion as a new model for the study of lung preservation. Using human lungs instead of animal models may bring the results of experimental studies closer to what could be expected in clinical practice. METHOD: Brain-dead donors whose lungs had been declined by transplantation teams were used. The cases were randomized into two groups. In Group 1, Perfadex® was used for pulmonary preservation, and in Group 2, LPDnac, a solution manufactured in Brazil, was used. An ex vivo lung perfusion system was used, and the lungs were ventilated and perfused after 10 hours of cold ischemia. The extent of ischemic-reperfusion injury was measured using functional and histological parameters. RESULTS: After reperfusion, the mean oxygenation capacity was 405.3 mmHg in Group 1 and 406.0 mmHg in Group 2 (p = 0.98). The mean pulmonary vascular resistance values were 697.6 and 378.3 dyn·s·cm-5, respectively (p = 0.035). The mean pulmonary compliance was 46.8 cm H2O in Group 1 and 49.3 ml/cm H2O in Group 2 (p = 0.816). The mean wet/dry weight ratios were 2.06 and 2.02, respectively (p = 0.87). The mean Lung Injury Scores for the biopsy performed after reperfusion were 4.37 and 4.37 in Groups 1 and 2, respectively (p = 1.0), and the apoptotic cell counts were 118.75/mm2 and 137.50/mm2, respectively (p = 0.71). CONCLUSION: The locally produced preservation solution proved to be as good as Perfadex®. The clinical use of LPDnac may reduce costs in our centers. Therefore, it is important to develop new models to study lung preservation. PMID:23018310

  19. Optical mapping of the isolated coronary-perfused human sinus node

    PubMed Central

    Fedorov, Vadim V.; Glukhov, Alexey V.; Chang, Roger; Kostecki, Geran; Aferol, Hyuliya; Hucker, William J.; Wuskell, Joe; Loew, Leslie M.; Schuessler, Richard B.; Moazami, Nader; Efimov, Igor R.

    2010-01-01

    Background The site of origin and pattern of excitation within the human sinoatrial node (SAN) has not been directly mapped. Objective We hypothesized that the human SAN is functionally insulated from the surrounding atrial myocardium except for several exit pathways which electrically bridge the nodal tissue and atrial myocardium. Methods The SAN was optically mapped in coronary perfused preparations from non-failing human hearts (n=4, age 54±15 years) using dye Di-4-ANBDQBS and Blebbistatin. SAN 3D structure was reconstructed using histology. Results Optical recordings from the SAN had diastolic depolarization and multiple upstroke components, which corresponded to the separate excitations of the SAN and atrial layers. Excitation originated in the middle of the SAN (66±17 BPM), then slowly (1–18 cm/s) and anisotropically spread. After a 82±17 ms conduction delay within the SAN, the atrial myocardium was excited via superior, middle, and/or inferior sinoatrial conduction pathways. Atrial excitation was initiated 9.4±4.2 mm from the leading pacemaker site. The oval 14.3±1.5 × 6.7±1.6 × 1.0±0.2 mm SAN structure was functionally insulated from the atrium by connective tissue, fat, and coronary arteries, except for these pathways. Conclusion These data demonstrated for the first time the location of the leading SAN pacemaker site, the pattern of excitation within the human SAN, and the conduction pathways into the right atrium. The existence of these pathways explained why, even during normal sinus rhythm, atrial breakthroughs could arise from a region parallel to the CT that is significantly larger (26.0±7.8 mm) than the area of the anatomically defined SAN. PMID:20946995

  20. Effects of pulsatile perfusion on human saphenous vein vasoreactivity: a preliminary report.

    PubMed

    Schwartz, L B; Purut, C M; Massey, M F; Pence, J C; Smith, P K; McCann, R L

    1996-04-01

    This study examined the effects of exposure to arterial blood pressure and flow on human saphenous vein catecholamine sensitivity. Unused portions of saphenous vein from eight patients undergoing peripheral bypass procedures were mounted parallel in a specially designed organ culture apparatus and perfused with tissue culture medium with 95% CO(2) at 37 degrees C. One segment was fixed between two cannulas while the medium was gently agitated (control) and the other was actively perfused via a pulsatile pump system at a rate of 60 beats/min, peak pressure of 100 mmHg and peak flow of 200 ml/min (pulsed; mean pressure 60 mmHg; mean flow 115 ml/min). After 48 h, vein segments were removed and tested for in vitro isometric contraction in response to KCI, norepinephrine and histamine, and relaxation in response to acetylcholine, calcium ionophore A23187, and sodium nitroprusside. There were no differences in mean(s.e.m.) maximal contraction in response to KCI (control 0.61(0.16) g versus pulsed 0.72(0.27)g; P = n.s.), norepinephrine (control 1.00(0.56) g versus pulsed 1.51(0.54) g; P= n.s.), or histamine (control 1.47(0.85) g versus pulsed 1.95(0.64) g; P= n.s.). However, pulsed veins exhibited increased sensitivity to both norepinephrine (control -logED50 6.20(0.23) versus pulsed mean(s.e.m.) 6.60(0.17); P< 0.05) and histamine (control -logED(50) 5.60(0.27) versus pulsed 6.24(0.20); P = 0.05). Pulsed veins exhibited slightly less acetylcholine-induced relaxation although the difference did not reach statistical significance (control mean(s.e.m.) relaxation at 1 x 10(6)M 9.2(14.0)% versus pulsed -13.3(6.4)%; P = n.s.). There were no differences in relaxation in response to either A23187 (control 1 x 10-(4)M 178(19)% versus pulsed 191(68)% or sodium nitroprusside (control 225(15)% versus pulsed 254(17)%; P = n.s.). The data presented herein indicate that exposure of human saphenous vein to the hemodynamics of the arterial environment for 48 h results in catecholamine

  1. External-to-Internal Iliac Stent-Graft: Medium-Term Patency Following Exclusion of a Retrogradely Perfused Common Iliac Aneurysm

    SciTech Connect

    Nicholls, Marcus John; McPherson, Simon

    2010-08-15

    Following complicated aortic aneurysm surgery a complete left iliac occlusion resulted in buttock claudication. A retrogradely perfused right common iliac aneurysm expanded. Exclusion was by external-to-internal iliac stent-graft. No deterioration in claudication occurred with medium-term stent-graft patency.

  2. Pancreatic Ductal Perfusion at Organ Procurement Enhances Islet Yield in Human Islet Isolation

    PubMed Central

    Shimoda, Masayuki; Kanak, Mazhar A.; Shahbazov, Rauf; Kunnathodi, Faisal; Lawrence, Michael C.; Naziruddin, Bashoo; Levy, Marlon F.

    2015-01-01

    Objective Pancreas preservation is a major factor influencing the results of islet cell transplantation. This study evaluated the effects of two different solutions for pancreatic ductal perfusion (PDP) at organ procurement. Methods Eighteen human pancreases were assigned to three groups: non-PDP (control), PDP with ET-Kyoto solution, and PDP with cold storage/purification stock solution. Pancreatic islets were isolated according to the modified Ricordi method. Results No significant differences in donor characteristics, including cold ischemia time, were observed between the three groups. All islet isolations in the PDP groups had >400,000 IEQ in total islet yield post-purification, a significant increase when compared with the control (P = 0.04 and <0.01). The islet quality assessments—including an in vivo diabetic nude mice assay and the response of high-mobility group box protein 1 to cytokine stimulation—also showed no significant differences. The proportion of TUNEL-positive cells showing apoptosis in islets in the PDP groups was significantly lower than in the control group (P < 0.05). Conclusion Both ET-Kyoto solution and cold storage/purification stock solution are suitable for PDP and consistently resulted in isolation success. Further studies with a larger number of pancreas donors should be done to compare the effects of the PDP solutions. PMID:25058879

  3. CT-perfusion imaging of the human brain: advanced deconvolution analysis using circulant singular value decomposition.

    PubMed

    Wittsack, H J; Wohlschläger, A M; Ritzl, E K; Kleiser, R; Cohnen, M; Seitz, R J; Mödder, U

    2008-01-01

    According to indicator dilution theory tissue time-concentration curves have to be deconvolved with arterial input curves in order to get valid perfusion results. Our aim was to adapt and validate a deconvolution method originating from magnetic resonance techniques and apply it to the calculation of dynamic contrast enhanced computed tomography perfusion imaging. The application of a block-circulant matrix approach for singular value decomposition renders the analysis independent of tracer arrival time to improve the results. PMID:18029143

  4. Platelet-activating factor causes ventilation-perfusion mismatch in humans.

    PubMed Central

    Rodriguez-Roisin, R; Félez, M A; Chung, K F; Barberà, J A; Wagner, P D; Cobos, A; Barnes, P J; Roca, J

    1994-01-01

    We hypothesized that platelet-activating factor (PAF), a potent inflammatory mediator, could induce gas exchange abnormalities in normal humans. To this end, the effect of aerosolized PAF (2 mg/ml solution; 24 micrograms) on ventilation-perfusion (VA/Q) relationships, hemodynamics, and resistance of the respiratory system was studied in 14 healthy, nonatopic, and nonsmoking individuals (23 +/- 1 [SEM]yr) before and at 2, 4, 6, 8, 15, and 45 min after inhalation, and compared to that of inhaled lyso-PAF in 10 other healthy individuals (24 +/- 2 yr). PAF induced, compared to lyso-PAF, immediate leukopenia (P < 0.001) followed by a rebound leukocytosis (P < 0.002), increased minute ventilation (P < 0.05) and resistance of the respiratory system (P < 0.01), and decreased systemic arterial pressure (P < 0.05). Similarly, compared to lyso-PAF, PaO2 showed a trend to fall (by 12.2 +/- 4.3 mmHg, mean +/- SEM maximum change from baseline), and arterial-alveolar O2 gradient increased (by 16.7 +/- 4.3 mmHg) (P < 0.02) after PAF, because of VA/Q mismatch: the dispersion of pulmonary blood flow and that of ventilation increased by 0.45 +/- 0.1 (P < 0.01) and 0.29 +/- 0.1 (P < 0.04), respectively. We conclude that in normal subjects, inhaled PAF results in considerable immediate VA/Q inequality and gas exchange impairment. These results reinforce the notion that PAF may play a major role as a mediator of inflammation in the human lung. Images PMID:8282786

  5. Isolated total lung perfusion as a means to deliver organ-specific chemotherapy: long-term studies in animals

    SciTech Connect

    Johnston, M.R.; Christensen, C.W.; Minchin, R.F.; Rickaby, D.A.; Linehan, J.H.; Schuller, H.M.; Boyd, M.R.; Dawson, C.A.

    1985-07-01

    The objectives of this study were to develop a surgical procedure that would allow for bilateral isolated lung perfusion in vivo as a means of delivering organ-specific chemotherapy and to evaluate the influence of the procedure on certain pulmonary physiologic parameters. The sterile surgical procedure that was carried out in dogs involved the setting up of two separate perfusion circuits. Once standard systemic cardiopulmonary bypass was established, a second circuit was devised to perfuse the lungs by placing an inflow cannula into the main pulmonary artery and collecting venous effluent in the left atrium. Cross-contamination between perfusion circuits was determined in acute studies with labeled plasma protein or red blood cells and was found to be in an acceptable range if the aorta was cross-clamped and the heart arrested. Only about 0.4 ml/min of pulmonary perfusate leaked into the systemic circulation, indicating that systemic toxicity should not be a major concern when chemotherapy agents are added to the pulmonary perfusate. Chronic studies demonstrated that hemodynamic parameters, lung water, pulmonary endothelial serotonin extraction, and histologic findings all showed minimal changes after 50 minutes of isolated lung perfusion. Five days after perfusion, lung dynamic compliance and peak serotonin extraction showed significant decreases. However, all of the measured parameters had returned toward baseline levels by the end of the 8-week postoperative study period. The procedure offers significant advantages over the previously described single lung perfusion and may provide a method of delivering immediate high-concentration adjuvant chemotherapy to coincide with resection of primary or metastatic lung tumors.

  6. The in vitro growth of a three-dimensional human dermal replacement using a single-pass perfusion system.

    PubMed

    Halberstadt, C R; Hardin, R; Bezverkov, K; Snyder, D; Allen, L; Landeen, L

    1994-04-01

    A human dermal replacement has been developed by seeding human neonatal dermal fibroblasts onto a biosorbable polyglactin (polyglycolide/polylactide) mesh and culturing in a bioreactor. The mesh provides the proper environment for the cells to attach, grow in a three-dimensional array, and establish a tissue matrix over a 2- to 3-week culture period. The dermal replacement has been characterized and found to contain a variety of naturally occurring dermal matrix proteins, including fibronectin, glycosaminoglycans, and collagen types I and III. To efficiently and reproducibly produce this dermal tissue equivalent, a closed, single-pass perfusion system was developed and compared with a static process. In the single-pas perfusion system, growth medium (containing ascorbic acid) was perfused around the 4 x 6 in. pieces of mesh at specific flow rates determined by nutrient consumption and waste production rates. The flow rates used for this system indicate that a diffusion-limited regime exists with a mean residence time greater than 1 h for essential nutrients and factors. By controlling glucose concentrations in the system to a delta of 0.70 g/L from the inlet to the outlet of the bioreactor, it took 6 fewer days to grow a tissue similar to that produced by the static system. PMID:18615797

  7. Development of a normothermic extracorporeal liver perfusion system toward improving viability and function of human extended criteria donor livers.

    PubMed

    Banan, Babak; Watson, Rao; Xu, Min; Lin, Yiing; Chapman, William

    2016-07-01

    Donor organ shortages have led to an increased interest in finding new approaches to recover organs from extended criteria donors (ECD). Normothermic extracorporeal liver perfusion (NELP) has been proposed as a superior preservation method to reduce ischemia/reperfusion injury (IRI), precondition suboptimal grafts, and treat ECD livers so that they can be successfully used for transplantation. The aim of this study was to investigate the beneficial effects of a modified NELP circuit on discarded human livers. Seven human livers that were rejected for transplantation were placed on a modified NELP circuit for 8 hours. Perfusate samples and needle core biopsies were obtained at hourly intervals. A defatting solution that contained exendin-4 (50 nM) and L-carnitine (10 mM) was added to the perfusate for 2 steatotic livers. NELP provided normal temperature, electrolytes, and pH and glucose levels in the perfusate along with physiological vascular flows and pressures. Functional, biochemical, and microscopic evaluation revealed no additional injuries to the grafts during NELP with an improved oxygen extraction ratio (>0.5) and stabilized markers of hepatic injury. All livers synthesized adequate amounts of bile and coagulation factors. We also demonstrated a mild reduction (10%) of macroglobular steatosis with the use of the defatting solution. Histology demonstrated normal parenchymal architecture and a minimal to complete lack of IRI at the end of NELP. In conclusion, a modified NELP circuit preserved hepatocyte architecture, recovered synthetic functions, and hepatobiliary parameters of ECD livers without additional injuries to the grafts. This approach has the potential to increase the donor pool for clinical transplantation. Liver Transplantation 22 979-993 2016 AASLD. PMID:27027254

  8. Central pain mechanisms following combined acid and capsaicin perfusion of the human oesophagus.

    PubMed

    Brock, Christina; Andresen, Trine; Frøkjaer, Jens Brøndum; Gale, Jeremy; Olesen, Anne Estrup; Arendt-Nielsen, Lars; Drewes, Asbjørn Mohr

    2010-03-01

    Visceral afferents originating from different gut-segments converge at the spinal level. We hypothesized that chemically-induced hyperalgesia in the oesophagus could provoke widespread visceral hypersensitivity and also influence descending modulatory pain pathways. Fifteen healthy volunteers were studied at baseline, 30, 60 and 90 min after randomized perfusion of the distal oesophagus with either saline or 180 ml 0.1M HCl+2mg capsaicin. Electro-stimulation of the oesophagus, 8 cm proximal to the perfusion site, rectosigmoid electrical stimulation and rectal mechanical and heat stimulations were used. Evoked brain potentials were recorded after electrical stimulations before and after oesophageal perfusion. After the perfusion, rectal hyperalgesia to heat (P<0.01, 37%) and mechanical (P=0.01, 11%) stimulations were demonstrated. In contrast, hypoalgesia to electro-stimulation was observed in both the oesophagus (P<0.03, 23%) and the sigmoid colon (P<0.001, 18%). Referred pain areas to electro-stimulation in oesophagus were reduced by 13% after perfusion (P=0.01). Evoked brain potentials to rectosigmoid stimulations showed decreased latencies and amplitudes of P1, N1 and P2 (P<0.05), whereas oesophagus-evoked brain potentials were unaffected after perfusion. In conclusion, modality-specific hyperalgesia was demonstrated in the lower gut following chemical sensitization of the oesophagus, reflecting widespread central hyperexcitability. Conversely, hypoalgesia to electrical stimulation, decreases in referred pain and latencies of evoked brain potentials was seen. This outcome may reflect a counterbalancing activation of descending inhibitory pathways. As these findings are also seen in the clinical setting, the model may be usable for future basic and pharmacological studies. PMID:19541517

  9. A Perfusion-based Human Cadaveric Model for Management of Carotid Artery Injury during Endoscopic Endonasal Skull Base Surgery

    PubMed Central

    Pham, Martin; Kale, Aydemir; Marquez, Yvette; Winer, Jesse; Lee, Brian; Harris, Brianna; Minnetti, Michael; Carey, Joseph; Giannotta, Steven; Zada, Gabriel

    2014-01-01

    Objective To create and develop a reproducible and realistic training environment to prepare residents and trainees for arterial catastrophes during endoscopic endonasal surgery. Design An artificial blood substitute was perfused at systolic blood pressures in eight fresh human cadavers to mimic intraoperative scenarios. Setting The USC Keck School of Medicine Fresh Tissue Dissection Laboratory was used as the training site. Participants Trainees were USC neurosurgery residents and junior faculty. Main Outcome A 5-point questionnaire was used to assess pre- and posttraining confidence scores. Results High-pressure extravasation at normal arterial blood pressure mimicked real intraoperative internal carotid artery (ICA) injury. Residents developed psychomotor skills required to achieve hemostasis using suction, cottonoids, and muscle grafts. Questionnaire responses from all trainees reported a realistic experience enhanced by the addition of the perfusion model. Conclusions The addition of an arterial perfusion system to fresh tissue cadavers is among the most realistic training models available. This enables the simulation of rare intraoperative scenarios such as ICA injury. Strategies for rapid hemostasis and implementation of techniques including endoscope manipulation, suction, and packing can all be rehearsed via this novel paradigm. PMID:25301092

  10. Asymmetrical transfer of alpha-aminoisobutyric acid (AIB), leucine and lysine across the in vitro perfused human placenta.

    PubMed

    Schneider, H; Proegler, M; Sodha, R; Dancis, J

    1987-01-01

    The mechanism for establishing transplacental gradients for leucine, lysine and alpha-aminoisobutyric acid (AIB) has been investigated in the perfused human placenta. Experiments were done with either the maternal or the fetal circulation closed and the donor circulation open. Transfer of the amino acids towards the fetal side was more rapid than it was in the reverse direction. When the maternal perfusate was recirculated, the amino acid concentrations were maintained at a considerably lower level in the maternal circulation than in the open fetal circuit. When the fetal circuit was closed, the concentrations approached or slightly exceeded those in the maternal perfusate over a period of three hours. Within the placenta, higher concentrations were established during the experiments with transfer towards the fetal side than in the reverse direction. Of the three amino acids, leucine was transferred most rapidly across the placenta while AIB reached the highest concentrations in the placental tissue. The asymmetry of the transplacental amino acid flux is favoured by rapid uptake from the maternal circulation and transfer towards the fetus. Both rates exceed those observed in the reverse direction. The transfer rate of D-leucine was 1.7 times that of L-glucose. For in vitro studies of the transfer rate of physiological compounds a correction for diffusion is required. The results may differ considerably depending on which marker is used as the basis. PMID:3112761

  11. A Perfusion-based Human Cadaveric Model for Management of Carotid Artery Injury during Endoscopic Endonasal Skull Base Surgery.

    PubMed

    Pham, Martin; Kale, Aydemir; Marquez, Yvette; Winer, Jesse; Lee, Brian; Harris, Brianna; Minnetti, Michael; Carey, Joseph; Giannotta, Steven; Zada, Gabriel

    2014-10-01

    Objective To create and develop a reproducible and realistic training environment to prepare residents and trainees for arterial catastrophes during endoscopic endonasal surgery. Design An artificial blood substitute was perfused at systolic blood pressures in eight fresh human cadavers to mimic intraoperative scenarios. Setting The USC Keck School of Medicine Fresh Tissue Dissection Laboratory was used as the training site. Participants Trainees were USC neurosurgery residents and junior faculty. Main Outcome A 5-point questionnaire was used to assess pre- and posttraining confidence scores. Results High-pressure extravasation at normal arterial blood pressure mimicked real intraoperative internal carotid artery (ICA) injury. Residents developed psychomotor skills required to achieve hemostasis using suction, cottonoids, and muscle grafts. Questionnaire responses from all trainees reported a realistic experience enhanced by the addition of the perfusion model. Conclusions The addition of an arterial perfusion system to fresh tissue cadavers is among the most realistic training models available. This enables the simulation of rare intraoperative scenarios such as ICA injury. Strategies for rapid hemostasis and implementation of techniques including endoscope manipulation, suction, and packing can all be rehearsed via this novel paradigm. PMID:25301092

  12. Human periosteal-derived cell expansion in a perfusion bioreactor system: proliferation, differentiation and extracellular matrix formation.

    PubMed

    Sonnaert, M; Papantoniou, I; Bloemen, V; Kerckhofs, G; Luyten, F P; Schrooten, J

    2014-09-01

    Perfusion bioreactor systems have shown to be a valuable tool for the in vitro development of three-dimensional (3D) cell-carrier constructs. Their use for cell expansion, however, has been much less explored. Since maintenance of the initial cell phenotype is essential in this process, it is imperative to obtain insight into the bioreactor-related variables determining cell fate. Therefore, this study investigated the influence of fluid flow-induced shear stress on the proliferation, differentiation and matrix deposition of human periosteal-derived cells in the absence of additional differentiation-inducing stimuli; 120 000 cells were seeded on additive manufactured 3D Ti6Al4V scaffolds and cultured for up to 28 days at different flow rates in the range 0.04-6 ml/min. DNA measurements showed, on average, a three-fold increase in cell content for all perfused conditions in comparison to static controls, whereas the magnitude of the flow rate did not have an influence. Contrast-enhanced nanofocus X-ray computed tomography showed substantial formation of an engineered neotissue in all perfused conditions, resulting in a filling (up to 70%) of the total internal void volume, and no flow rate-dependent differences were observed. The expression of key osteogenic markers, such as RunX2, OCN, OPN and Col1, did not show any significant changes in comparison to static controls after 28 days of culture, with the exception of OSX at high flow rates. We therefore concluded that, in the absence of additional osteogenic stimuli, the investigated perfusion conditions increased cell proliferation but did not significantly enhance osteogenic differentiation, thus allowing for this process to be used for cell expansion. Copyright © 2014 John Wiley & Sons, Ltd. PMID:25186024

  13. The impact of age on cerebral perfusion, oxygenation and metabolism during exercise in humans.

    PubMed

    Braz, Igor D; Fisher, James P

    2016-08-15

    Age is one of the most important risk factors for dementia and stroke. Examination of the cerebral circulatory responses to acute exercise in the elderly may help to pinpoint the mechanisms by which exercise training can reduce the risk of brain diseases, inform the optimization of exercise training programmes and assist with the identification of age-related alterations in cerebral vascular function. During low-to-moderate intensity dynamic exercise, enhanced neuronal activity is accompanied by cerebral perfusion increases of ∼10-30%. Beyond ∼60-70% maximal oxygen uptake, cerebral metabolism remains elevated but perfusion in the anterior portion of the circulation returns towards baseline, substantively because of a hyperventilation-mediated reduction in the partial pressure of arterial carbon dioxide (P aC O2) and cerebral vasoconstriction. Cerebral perfusion is lower in older individuals, both at rest and during incremental dynamic exercise. Nevertheless, the increase in the estimated cerebral metabolic rate for oxygen and the arterial-internal jugular venous differences for glucose and lactate are similar in young and older individuals exercising at the same relative exercise intensities. Correction for the age-related reduction in P aC O2 during exercise by the provision of supplementary CO2 is suggested to remove ∼50% of the difference in cerebral perfusion between young and older individuals. A multitude of candidates could account for the remaining difference, including cerebral atrophy, and enhanced vasoconstrictor and blunted vasodilatory pathways. In summary, age-related reductions in cerebral perfusion during exercise are partly associated with a lower P aC O2 in exercising older individuals; nevertheless the cerebral extraction of glucose, lactate and oxygen appear to be preserved. PMID:26435295

  14. Incubator-independent cell-culture perfusion platform for continuous long-term microelectrode array electrophysiology and time-lapse imaging

    PubMed Central

    Saalfrank, Dirk; Konduri, Anil Krishna; Latifi, Shahrzad; Habibey, Rouhollah; Golabchi, Asiyeh; Martiniuc, Aurel Vasile; Knoll, Alois; Ingebrandt, Sven; Blau, Axel

    2015-01-01

    Most in vitro electrophysiology studies extract information and draw conclusions from representative, temporally limited snapshot experiments. This approach bears the risk of missing decisive moments that may make a difference in our understanding of physiological events. This feasibility study presents a simple benchtop cell-culture perfusion system adapted to commercial microelectrode arrays (MEAs), multichannel electrophysiology equipment and common inverted microscopy stages for simultaneous and uninterrupted extracellular electrophysiology and time-lapse imaging at ambient CO2 levels. The concept relies on a transparent, replica-casted polydimethylsiloxane perfusion cap, gravity- or syringe-pump-driven perfusion and preconditioning of pH-buffered serum-free cell-culture medium to ambient CO2 levels at physiological temperatures. The low-cost microfluidic in vitro enabling platform, which allows us to image cultures immediately after cell plating, is easy to reproduce and is adaptable to the geometries of different cell-culture containers. It permits the continuous and simultaneous multimodal long-term acquisition or manipulation of optical and electrophysiological parameter sets, thereby considerably widening the range of experimental possibilities. Two exemplary proof-of-concept long-term MEA studies on hippocampal networks illustrate system performance. Continuous extracellular recordings over a period of up to 70 days revealed details on both sudden and gradual neural activity changes in maturing cell ensembles with large intra-day fluctuations. Correlated time-lapse imaging unveiled rather static macroscopic network architectures with previously unreported local morphological oscillations on the timescale of minutes. PMID:26543581

  15. Incubator-independent cell-culture perfusion platform for continuous long-term microelectrode array electrophysiology and time-lapse imaging.

    PubMed

    Saalfrank, Dirk; Konduri, Anil Krishna; Latifi, Shahrzad; Habibey, Rouhollah; Golabchi, Asiyeh; Martiniuc, Aurel Vasile; Knoll, Alois; Ingebrandt, Sven; Blau, Axel

    2015-06-01

    Most in vitro electrophysiology studies extract information and draw conclusions from representative, temporally limited snapshot experiments. This approach bears the risk of missing decisive moments that may make a difference in our understanding of physiological events. This feasibility study presents a simple benchtop cell-culture perfusion system adapted to commercial microelectrode arrays (MEAs), multichannel electrophysiology equipment and common inverted microscopy stages for simultaneous and uninterrupted extracellular electrophysiology and time-lapse imaging at ambient CO2 levels. The concept relies on a transparent, replica-casted polydimethylsiloxane perfusion cap, gravity- or syringe-pump-driven perfusion and preconditioning of pH-buffered serum-free cell-culture medium to ambient CO2 levels at physiological temperatures. The low-cost microfluidic in vitro enabling platform, which allows us to image cultures immediately after cell plating, is easy to reproduce and is adaptable to the geometries of different cell-culture containers. It permits the continuous and simultaneous multimodal long-term acquisition or manipulation of optical and electrophysiological parameter sets, thereby considerably widening the range of experimental possibilities. Two exemplary proof-of-concept long-term MEA studies on hippocampal networks illustrate system performance. Continuous extracellular recordings over a period of up to 70 days revealed details on both sudden and gradual neural activity changes in maturing cell ensembles with large intra-day fluctuations. Correlated time-lapse imaging unveiled rather static macroscopic network architectures with previously unreported local morphological oscillations on the timescale of minutes. PMID:26543581

  16. Transfer studies of polystyrene nanoparticles in the ex vivo human placenta perfusion model: key sources of artifacts

    NASA Astrophysics Data System (ADS)

    Grafmueller, Stefanie; Manser, Pius; Diener, Liliane; Maurizi, Lionel; Diener, Pierre-André; Hofmann, Heinrich; Jochum, Wolfram; Krug, Harald F.; Buerki-Thurnherr, Tina; von Mandach, Ursula; Wick, Peter

    2015-08-01

    Nanotechnology is a rapidly expanding and highly promising new technology with many different fields of application. Consequently, the investigation of engineered nanoparticles in biological systems is steadily increasing. Questions about the safety of such engineered nanoparticles are very important and the most critical subject with regard to the penetration of biological barriers allowing particle distribution throughout the human body. Such translocation studies are technically challenging and many issues have to be considered to obtain meaningful and comparable results. Here we report on the transfer of polystyrene nanoparticles across the human placenta using an ex vivo human placenta perfusion model. We provide an overview of several challenges that can potentially occur in any translocation study in relation to particle size distribution, functionalization and stability of labels. In conclusion, a careful assessment of nanoparticle properties in a physiologically relevant milieu is as challenging and important as the actual study of nanoparticle-cell interactions itself.

  17. Chondrogenic differentiation of human bone marrow mesenchymal stem cells in chitosan-based scaffolds using a flow-perfusion bioreactor.

    PubMed

    Alves da Silva, M L; Martins, A; Costa-Pinto, A R; Correlo, V M; Sol, P; Bhattacharya, M; Faria, S; Reis, R L; Neves, N M

    2011-10-01

    Native articular cartilage is subjected to synovial fluid flow during normal joint function. Thus, it is believed that the morphogenesis of articular cartilage may be positively regulated by the application of similar stimulation in vitro. In the present study, the effect of fluid flow over the chondrogenic differentiation of human bone marrow-derived mesenchymal stem cells (hBM-MSCs) was investigated. We intended to find out whether the shear stress caused by perfusion of the medium through the constructs was capable of augmenting the differentiation process. Human BMSCs were isolated from bone marrow aspirates and were characterized by flow cytometry. After expansion, hBM-MSCs were seeded statically onto fibre mesh scaffolds, consisting of a blend of 50:50 chitosan:poly(butylene terephthalate adipate) (CPBTA). Constructs were cultured in a flow-perfusion bioreactor for 28 days, using complete medium for chondrogenesis supplemented by TGFβ3. An enhanced ECM deposition and collagen type II production was observed in the bioreactor samples when compared to the static controls. Moreover, it was observed that hBM-MSCs, in static cultures, take longer to differentiate. ECM accumulation in these samples is lower than in the bioreactor sections, and there is a significant difference in the expression of collagen type I. We found that the flow-induced shear stress has a beneficial effect on the chondrogenic differentiation of hMSCs. PMID:21953870

  18. Maternal-fetal transfer of indocyanine green across the perfused human placenta.

    PubMed

    Rubinchik-Stern, Miriam; Shmuel, Miriam; Bar, Jacob; Eyal, Sara; Kovo, Michal

    2016-07-01

    Indocyanine green (ICG) is an FDA-approved near-infrared imaging probe, given also to pregnant women. We aimed to characterize ICG's transplacental transfer using the ex-vivo perfusion model. Placentas were obtained from caesarean deliveries. Cotyledons were cannulated and dually perfused. ICG, 9.6μg/mL and antipyrine (50μg/mL) were added to the maternal circulation in the absence (n=4) or the presence of the organic anion transporting polypeptide (OATPs) inhibitor rifampin (10μg/mL; n=5) or the P-glycoprotein inhibitor valspodar (2μg/mL; n=3). ICG's maternal-to-fetal transfer was evaluated over 180min. The cumulative percent of ICG in the fetal reservoir was minor. When ICG transfer was normalized to that of antipyrine, it was lower in the presence of rifampin (a 41% decrease; p<0.05). Valspodar did not appear to modify the kinetics of ICG. ICG's transplacental transfer is minimal and is probably OATP-mediated. The placenta is an effective protective barrier to ICG's distribution into the fetus. PMID:27132189

  19. Human Behaviour in Long-Term Missions

    NASA Technical Reports Server (NTRS)

    1997-01-01

    In this session, Session WP1, the discussion focuses on the following topics: Psychological Support for International Space Station Mission; Psycho-social Training for Man in Space; Study of the Physiological Adaptation of the Crew During A 135-Day Space Simulation; Interpersonal Relationships in Space Simulation, The Long-Term Bed Rest in Head-Down Tilt Position; Psychological Adaptation in Groups of Varying Sizes and Environments; Deviance Among Expeditioners, Defining the Off-Nominal Act in Space and Polar Field Analogs; Getting Effective Sleep in the Space-Station Environment; Human Sleep and Circadian Rhythms are Altered During Spaceflight; and Methodological Approach to Study of Cosmonauts Errors and Its Instrumental Support.

  20. Single-Pass Intestinal Perfusion (SPIP) and prediction of fraction absorbed and permeability in humans: A study with antiretroviral drugs.

    PubMed

    Dezani, Thaisa Marinho; Dezani, André Bersani; Junior, João Batista da Silva; Serra, Cristina Helena Dos Reis

    2016-07-01

    In recent years, the prediction of oral drug absorption in humans has been a challenge for researchers and many techniques for permeability studies have been developed for several purposes, including biowaiver processes. The Single-Pass Intestinal Perfusion (SPIP) method performed in rats can provide permeability results closest to in vivo condition. The purpose of the present study was to evaluate the intestinal permeability of the antiretroviral drugs lamivudine, stavudine and zidovudine using the SPIP method in rats and to predict their permeability (Peff,humans) and fraction absorbed (Fa) in humans. Metoprolol and fluorescein were used as marker compounds of high and low permeability, respectively. The effective permeability (Peff) results showed that stavudine and zidovudine have high permeability characteristics while lamivudine presented the lowest result. From Peff values obtained in rats, the Peff,humans and Fa were calculated. The use of SPIP in rats and calculations for absorption prediction in humans may indicate the transport mechanisms and/or pre-systemic metabolism involved on permeation processes of drugs, since this model is the closest to in vivo conditions. PMID:27130787

  1. Glycopyrrolate abolishes the exercise-induced increase in cerebral perfusion in humans.

    PubMed

    Seifert, Thomas; Fisher, James P; Young, Colin N; Hartwich, Doreen; Ogoh, Shigehiko; Raven, Peter B; Fadel, Paul J; Secher, Niels H

    2010-10-01

    Brain blood vessels contain muscarinic receptors that are important for cerebral blood flow (CBF) regulation, but whether a cholinergic receptor mechanism is involved in the exercise-induced increase in cerebral perfusion or affects cerebral metabolism remains unknown. We evaluated CBF and cerebral metabolism (from arterial and internal jugular venous O(2), glucose and lactate differences), as well as the middle cerebral artery mean blood velocity (MCA V(mean); transcranial Doppler ultrasound) during a sustained static handgrip contraction at 40% of maximal voluntary contraction (n = 9) and the MCA V(mean) during ergometer cycling (n = 8). Separate, randomized and counterbalanced trials were performed in control (no drug) conditions and following muscarinic cholinergic receptor blockade by glycopyrrolate. Glycopyrrolate increased resting heart rate from approximately 60 to approximately 110 beats min(-1) (P < 0.01) and cardiac output by approximately 40% (P < 0.05), but did not affect mean arterial pressure. The central cardiovascular responses to exercise with glycopyrrolate were similar to the control responses, except that cardiac output did not increase during static handgrip with glycopyrrolate. Glycopyrrolate did not significantly affect cerebral metabolism during static handgrip, but a parallel increase in MCA V(mean) (approximately 16%; P < 0.01) and CBF (approximately 12%; P < 0.01) during static handgrip, as well as the increase in MCA V(mean) during cycling (approximately 15%; P < 0.01), were abolished by glycopyrrolate (P < 0.05). Thus, during both cycling and static handgrip, a cholinergic receptor mechanism is important for the exercise-induced increase in cerebral perfusion without affecting the cerebral metabolic rate for oxygen. PMID:20660020

  2. Bonded Cumomer Analysis of Human Melanoma Metabolism Monitored by 13C NMR Spectroscopy of Perfused Tumor Cells.

    PubMed

    Shestov, Alexander A; Mancuso, Anthony; Lee, Seung-Cheol; Guo, Lili; Nelson, David S; Roman, Jeffrey C; Henry, Pierre-Gilles; Leeper, Dennis B; Blair, Ian A; Glickson, Jerry D

    2016-03-01

    A network model for the determination of tumor metabolic fluxes from (13)C NMR kinetic isotopomer data has been developed and validated with perfused human DB-1 melanoma cells carrying the BRAF V600E mutation, which promotes oxidative metabolism. The model generated in the bonded cumomer formalism describes key pathways of tumor intermediary metabolism and yields dynamic curves for positional isotopic enrichment and spin-spin multiplets. Cells attached to microcarrier beads were perfused with 26 mm [1,6-(13)C2]glucose under normoxic conditions at 37 °C and monitored by (13)C NMR spectroscopy. Excellent agreement between model-predicted and experimentally measured values of the rates of oxygen and glucose consumption, lactate production, and glutamate pool size validated the model. ATP production by glycolytic and oxidative metabolism were compared under hyperglycemic normoxic conditions; 51% of the energy came from oxidative phosphorylation and 49% came from glycolysis. Even though the rate of glutamine uptake was ∼ 50% of the tricarboxylic acid cycle flux, the rate of ATP production from glutamine was essentially zero (no glutaminolysis). De novo fatty acid production was ∼ 6% of the tricarboxylic acid cycle flux. The oxidative pentose phosphate pathway flux was 3.6% of glycolysis, and three non-oxidative pentose phosphate pathway exchange fluxes were calculated. Mass spectrometry was then used to compare fluxes through various pathways under hyperglycemic (26 mm) and euglycemic (5 mm) conditions. Under euglycemic conditions glutamine uptake doubled, but ATP production from glutamine did not significantly change. A new parameter measuring the Warburg effect (the ratio of lactate production flux to pyruvate influx through the mitochondrial pyruvate carrier) was calculated to be 21, close to upper limit of oxidative metabolism. PMID:26703469

  3. Ex vivo lung perfusion.

    PubMed

    Reeb, Jeremie; Cypel, Marcelo

    2016-03-01

    Lung transplantation is an established life-saving therapy for patients with end-stage lung disease. Unfortunately, greater success in lung transplantation is hindered by a shortage of lung donors and the relatively poor early-, mid-, and long-term outcomes associated with severe primary graft dysfunction. Ex vivo lung perfusion has emerged as a modern preservation technique that allows for a more accurate lung assessment and improvement in lung quality. This review outlines the: (i) rationale behind the method; (ii) techniques and protocols; (iii) Toronto ex vivo lung perfusion method; (iv) devices available; and (v) clinical experience worldwide. We also highlight the potential of ex vivo lung perfusion in leading a new era of lung preservation. PMID:26700566

  4. Temperature-dependent versus constant-rate blood perfusion modelling in ferromagnetic thermoseed hyperthermia: results with a model of the human prostate.

    PubMed

    Tompkins, D T; Vanderby, R; Klein, S A; Beckman, W A; Steeves, R A; Frye, D M; Paliwal, B R

    1994-01-01

    Finite-element solutions to the Pennes bioheat equation are obtained with a model of a tumour-containing, human prostate and surrounding normal tissues. Simulations of ferromagnetic hyperthermia treatments are conducted on the tissue model in which the prostate is implanted with an irregularly spaced array of thermoseeds. Several combinations of thermoseed temperatures with different Curie points are investigated. Non-uniform, constant-rate blood perfusion models are studied and compared with temperature-dependent descriptions of blood perfusion. Blood perfusions in the temperature-dependent models initially increase with tissue temperature and then decrease at higher temperatures. Simulations with temperature-dependent versus constant-rate blood perfusion models reveal significant differences in temperature distributions in and surrounding the tumour-containing prostate. Results from the simulations include differences (between temperature-dependent and constant-rate models) in (1) the percentage of normal tissue volume and tumour volume at temperatures > 42 degrees C, and (2) temperature descriptors in the tumour (subscript t) and normal (subscript n) tissues including Tmax.t, Tmin.t and Tmax.n. Isotherms and grey-scale contours in the tumour and surrounding normal tissues are presented for four simulations that model a combination of high-temperature thermoseeds. Several simulations show that Tmin.t is between 1.7 and 2.6 degrees C higher and Tmax.n is between 2.1 and 3.3 degrees C higher with a temperature-dependent versus a comparable constant-rate blood perfusion model. The same simulations reveal that the percentages of tumour volume at temperatures > 42 degrees C are between 0 and 68% higher with the temperature-dependent versus the constant-rate perfusion model over all seed combinations studied. In summary, a numerical method is presented which makes it possible to investigate temperature-dependent, continuous functions of blood perfusion in simulations

  5. Long-term effects of cerebral hypoperfusion on neural density and function using misery perfusion animal model.

    PubMed

    Nishino, Asuka; Tajima, Yosuke; Takuwa, Hiroyuki; Masamoto, Kazuto; Taniguchi, Junko; Wakizaka, Hidekatsu; Kokuryo, Daisuke; Urushihata, Takuya; Aoki, Ichio; Kanno, Iwao; Tomita, Yutaka; Suzuki, Norihiro; Ikoma, Yoko; Ito, Hiroshi

    2016-01-01

    We investigated the chronic effects of cerebral hypoperfusion on neuronal density and functional hyperemia using our misery perfusion mouse model under unilateral common carotid artery occlusion (UCCAO). Neuronal density evaluated 28 days after UCCAO using [(11)C]flumazenil-PET and histology indicated no neurologic deficit in the hippocampus and neocortex. CBF response to sensory stimulation was assessed using laser-Doppler flowmetry. Percentage changes in CBF response of the ipsilateral hemisphere to UCCAO were 18.4 ± 3.0%, 6.9 ± 2.8%, 6.8 ± 2.3% and 4.9 ± 2.4% before, and 7, 14 and 28 days after UCCAO, respectively. Statistical significance was found at 7, 14 and 28 days after UCCAO (P < 0.01). Contrary to our previous finding (Tajima et al. 2014) showing recovered CBF response to hypercapnia on 28 days after UCCAO using the same model, functional hyperemia was sustained and became worse 28 days after UCCAO. PMID:27116932

  6. Long-term effects of cerebral hypoperfusion on neural density and function using misery perfusion animal model

    PubMed Central

    Nishino, Asuka; Tajima, Yosuke; Takuwa, Hiroyuki; Masamoto, Kazuto; Taniguchi, Junko; Wakizaka, Hidekatsu; Kokuryo, Daisuke; Urushihata, Takuya; Aoki, Ichio; Kanno, Iwao; Tomita, Yutaka; Suzuki, Norihiro; Ikoma, Yoko; Ito, Hiroshi

    2016-01-01

    We investigated the chronic effects of cerebral hypoperfusion on neuronal density and functional hyperemia using our misery perfusion mouse model under unilateral common carotid artery occlusion (UCCAO). Neuronal density evaluated 28 days after UCCAO using [11C]flumazenil-PET and histology indicated no neurologic deficit in the hippocampus and neocortex. CBF response to sensory stimulation was assessed using laser-Doppler flowmetry. Percentage changes in CBF response of the ipsilateral hemisphere to UCCAO were 18.4 ± 3.0%, 6.9 ± 2.8%, 6.8 ± 2.3% and 4.9 ± 2.4% before, and 7, 14 and 28 days after UCCAO, respectively. Statistical significance was found at 7, 14 and 28 days after UCCAO (P < 0.01). Contrary to our previous finding (Tajima et al. 2014) showing recovered CBF response to hypercapnia on 28 days after UCCAO using the same model, functional hyperemia was sustained and became worse 28 days after UCCAO. PMID:27116932

  7. In vivo (31)P magnetic resonance spectroscopy and morphometric analysis of the perfused vascular architecture of human glioma xenografts in nude mice.

    PubMed Central

    van der Sanden, B. P.; Rijken, P. F.; Heerschap, A.; Bernsen, H. J.; van der Kogel, A. J.

    1997-01-01

    The relationship between the bioenergetic status of human glioma xenografts in nude mice and morphometric parameters of the perfused vascular architecture was studied using (31)P magnetic resonance spectroscopy (MRS), fluorescence microscopy and two-dimensional digital image analysis. Two tumour lines with a different vascular architecture were used for this study. Intervascular distances and non-perfused area fractions varied greatly between tumours of the same line and tumours of different lines. The inorganic phosphate-nucleoside triphosphate (P(i)/NTP) ratio increased rapidly as mean intervascular distances increased from 100 microm to 300 microm. Two morphometric parameters - the percentage of intervascular distances larger than 200 microm (ivd200) and the non-perfused area fraction at a distance larger than 100 microm from a nearest perfused vessel (area100), - were deduced from these experiments and related to the P(i)/NTP ratio of the whole tumour. It is assumed that an aerobic to anaerobic transition influences the bioenergetic status, i.e. the P(i)/NTP ratio increased linearly with the percentage of ivd200 and the area100. PMID:9166934

  8. Interstitial Perfusion Culture with Specific Soluble Factors Inhibits Type I Collagen Production from Human Osteoarthritic Chondrocytes in Clinical-Grade Collagen Sponges.

    PubMed

    Mayer, Nathalie; Lopa, Silvia; Talò, Giuseppe; Lovati, Arianna B; Pasdeloup, Marielle; Riboldi, Stefania A; Moretti, Matteo; Mallein-Gerin, Frédéric

    2016-01-01

    Articular cartilage has poor healing ability and cartilage injuries often evolve to osteoarthritis. Cell-based strategies aiming to engineer cartilaginous tissue through the combination of biocompatible scaffolds and articular chondrocytes represent an alternative to standard surgical techniques. In this context, perfusion bioreactors have been introduced to enhance cellular access to oxygen and nutrients, hence overcoming the limitations of static culture and improving matrix deposition. Here, we combined an optimized cocktail of soluble factors, the BIT (BMP-2, Insulin, Thyroxin), and clinical-grade collagen sponges with a bidirectional perfusion bioreactor, namely the oscillating perfusion bioreactor (OPB), to engineer in vitro articular cartilage by human articular chondrocytes (HACs) obtained from osteoarthritic patients. After amplification, HACs were seeded and cultivated in collagen sponges either in static or dynamic conditions. Chondrocyte phenotype and the nature of the matrix synthesized by HACs were assessed using western blotting and immunohistochemistry analyses. Finally, the stability of the cartilaginous tissue produced by HACs was evaluated in vivo by subcutaneous implantation in nude mice. Our results showed that perfusion improved the distribution and quality of cartilaginous matrix deposited within the sponges, compared to static conditions. Specifically, dynamic culture in the OPB, in combination with the BIT cocktail, resulted in the homogeneous production of extracellular matrix rich in type II collagen. Remarkably, the production of type I collagen, a marker of fibrous tissues, was also inhibited, indicating that the association of the OPB with the BIT cocktail limits fibrocartilage formation, favoring the reconstruction of hyaline cartilage. PMID:27584727

  9. IFPA Meeting 2013 Workshop Report III: maternal placental immunological interactions, novel determinants of trophoblast cell fate, dual ex vivo perfusion of the human placenta.

    PubMed

    Abumaree, M H; Brownbill, P; Burton, G; Castillo, C; Chamley, L; Croy, B A; Drewlo, S; Dunk, C; Girard, S; Hansson, S; Jones, S; Jurisicova, A; Lewis, R; Letarte, M; Parast, M; Pehrson, C; Rappolee, D; Schneider, H; Tannetta, D; Varmuza, S; Wadsack, C; Wallace, A E; Zenerino, C; Lash, G E

    2014-02-01

    Workshops are an important part of the IFPA annual meeting as they allow for discussion of specialised topics. At IFPA meeting 2013 there were twelve themed workshops, three of which are summarized in this report. These workshops related to various aspects of placental biology but collectively covered areas of placental function, cell turnover and immunology: 1) immunology; 2) novel determinants of placental cell fate; 3) dual perfusion of human placental tissue. PMID:24321780

  10. Multislice perfusion imaging in human brain using the C-FOCI inversion pulse: comparison with hyperbolic secant.

    PubMed

    Yongbi, M N; Yang, Y; Frank, J A; Duyn, J H

    1999-12-01

    Perfusion studies based on pulsed arterial spin labeling have primarily applied hyperbolic secant (HS) pulses for spin inversion. To optimize perfusion sensitivity, it is highly desirable to implement the HS pulse with the same slice width as the width of the imaging pulse. Unfortunately, this approach causes interactions between the slice profiles and manifests as residual signal from static tissue in the resultant perfusion image. This problem is currently overcome by increasing the selective HS width relative to the imaging slice width. However, this solution increases the time for the labeled blood to reach the imaging slice (transit time), causing loss of perfusion sensitivity as a result of T(1) relaxation effects. In this study, we demonstrate that the preceding problems can be largely overcome by use of the C-shaped frequency offset corrected inversion (FOCI) pulse [Ordidge et al., Magn Reson Med 1996;36:562]. The implementation of this pulse for multislice perfusion imaging on the cerebrum is presented, showing substantial improvement in slice definition in vivo compared with the HS pulse. The sharper FOCI profile is shown to reduce the physical gap (or "safety margin") between the inversion and imaging slabs, resulting in a significant increase in perfusion signal without residual contamination from static tissue. The mean +/- SE (n = 6) gray matter perfusion-weighted signal (DeltaM/M(o)) without the application of vascular signal suppression gradients were 1.19 +/- 0. 10% (HS-flow-sensitive alternating inversion recovery [FAIR]), and 1. 51 +/- 0.11% for the FOCI-FAIR sequence. The corresponding values with vascular signal suppression were 0.64 +/- 0.14%, and 0.91 +/- 0. 08% using the HS- and FOCI-FAIR sequences, respectively. Compared with the HS-based data, the FOCI-FAIR results correspond to an average increase in perfusion signal of up to between 26%-30%. Magn Reson Med 42:1098-1105, 1999. PMID:10571931

  11. Distribution of perfusion.

    PubMed

    Glenny, Robb; Robertson, H Thomas

    2011-01-01

    Local driving pressures and resistances within the pulmonary vascular tree determine the distribution of perfusion in the lung. Unlike other organs, these local determinants are significantly influenced by regional hydrostatic and alveolar pressures. Those effects on blood flow distribution are further magnified by the large vertical height of the human lung and the relatively low intravascular pressures in the pulmonary circulation. While the distribution of perfusion is largely due to passive determinants such as vascular geometry and hydrostatic pressures, active mechanisms such as vasoconstriction induced by local hypoxia can also redistribute blood flow. This chapter reviews the determinants of regional lung perfusion with a focus on vascular tree geometry, vertical gradients induced by gravity, the interactions between vascular and surrounding alveolar pressures, and hypoxic pulmonary vasoconstriction. While each of these determinants of perfusion distribution can be examined in isolation, the distribution of blood flow is dynamically determined and each component interacts with the others so that a change in one region of the lung influences the distribution of blood flow in other lung regions. PMID:23737171

  12. Metabolite Profiling and Pharmacokinetic Evaluation of Hydrocortisone in a Perfused Three-Dimensional Human Liver Bioreactor

    PubMed Central

    Sarkar, Ujjal; Rivera-Burgos, Dinelia; Large, Emma M.; Hughes, David J.; Ravindra, Kodihalli C.; Dyer, Rachel L.; Ebrahimkhani, Mohammad R.; Griffith, Linda G.

    2015-01-01

    Endotoxin lipopolysaccharide (LPS) is known to cause liver injury primarily involving inflammatory cells such as Kupffer cells, but few in vitro culture models are applicable for investigation of inflammatory effects on drug metabolism. We have developed a three-dimensional human microphysiological hepatocyte–Kupffer cell coculture system and evaluated the anti-inflammatory effect of glucocorticoids on liver cultures. LPS was introduced to the cultures to elicit an inflammatory response and was assessed by the release of proinflammatory cytokines, interleukin 6 and tumor necrosis factor α. A sensitive and specific reversed-phase–ultra high-performance liquid chromatography–quadrupole time of flight–mass spectrometry method was used to evaluate hydrocortisone disappearance and metabolism at near physiologic levels. For this, the systems were dosed with 100 nM hydrocortisone and circulated for 2 days; hydrocortisone was depleted to approximately 30 nM, with first-order kinetics. Phase I metabolites, including tetrahydrocortisone and dihydrocortisol, accounted for 8–10% of the loss, and 45–52% consisted of phase II metabolites, including glucuronides of tetrahydrocortisol and tetrahydrocortisone. Pharmacokinetic parameters, i.e., half-life, rate of elimination, clearance, and area under the curve, were 23.03 hours, 0.03 hour−1, 6.6 × 10−5 l⋅hour−1, and 1.03 (mg/l)*h, respectively. The ability of the bioreactor to predict the in vivo clearance of hydrocortisone was characterized, and the obtained intrinsic clearance values correlated with human data. This system offers a physiologically relevant tool for investigating hepatic function in an inflamed liver. PMID:25926431

  13. Hepatic Differentiation of Human Induced Pluripotent Stem Cells in a Perfused Three-Dimensional Multicompartment Bioreactor

    PubMed Central

    Freyer, Nora; Knöspel, Fanny; Strahl, Nadja; Amini, Leila; Schrade, Petra; Bachmann, Sebastian; Damm, Georg; Seehofer, Daniel; Jacobs, Frank; Monshouwer, Mario; Zeilinger, Katrin

    2016-01-01

    Abstract The hepatic differentiation of human induced pluripotent stem cells (hiPSC) holds great potential for application in regenerative medicine, pharmacological drug screening, and toxicity testing. However, full maturation of hiPSC into functional hepatocytes has not yet been achieved. In this study, we investigated the potential of a dynamic three-dimensional (3D) hollow fiber membrane bioreactor technology to improve the hepatic differentiation of hiPSC in comparison to static two-dimensional (2D) cultures. A total of 100 × 106 hiPSC were seeded into each 3D bioreactor (n = 3). Differentiation into definitive endoderm (DE) was induced by adding activin A, Wnt3a, and sodium butyrate to the culture medium. For further maturation, hepatocyte growth factor and oncostatin M were added. The same differentiation protocol was applied to hiPSC maintained in 2D cultures. Secretion of alpha-fetoprotein (AFP), a marker for DE, was significantly (p < 0.05) higher in 2D cultures, while secretion of albumin, a typical characteristic for mature hepatocytes, was higher after hepatic differentiation of hiPSC in 3D bioreactors. Functional analysis of multiple cytochrome P450 (CYP) isoenzymes showed activity of CYP1A2, CYP2B6, and CYP3A4 in both groups, although at a lower level compared to primary human hepatocytes (PHH). CYP2B6 activities were significantly (p < 0.05) higher in 3D bioreactors compared with 2D cultures, which is in line with results from gene expression. Immunofluorescence staining showed that the majority of cells was positive for albumin, cytokeratin 18 (CK18), and hepatocyte nuclear factor 4-alpha (HNF4A) at the end of the differentiation process. In addition, cytokeratin 19 (CK19) staining revealed the formation of bile duct-like structures in 3D bioreactors similar to native liver tissue. The results indicate a better maturation of hiPSC in the 3D bioreactor system compared to 2D cultures and emphasize the potential of dynamic 3D culture

  14. Hepatic Differentiation of Human Induced Pluripotent Stem Cells in a Perfused Three-Dimensional Multicompartment Bioreactor.

    PubMed

    Freyer, Nora; Knöspel, Fanny; Strahl, Nadja; Amini, Leila; Schrade, Petra; Bachmann, Sebastian; Damm, Georg; Seehofer, Daniel; Jacobs, Frank; Monshouwer, Mario; Zeilinger, Katrin

    2016-01-01

    The hepatic differentiation of human induced pluripotent stem cells (hiPSC) holds great potential for application in regenerative medicine, pharmacological drug screening, and toxicity testing. However, full maturation of hiPSC into functional hepatocytes has not yet been achieved. In this study, we investigated the potential of a dynamic three-dimensional (3D) hollow fiber membrane bioreactor technology to improve the hepatic differentiation of hiPSC in comparison to static two-dimensional (2D) cultures. A total of 100 × 10(6) hiPSC were seeded into each 3D bioreactor (n = 3). Differentiation into definitive endoderm (DE) was induced by adding activin A, Wnt3a, and sodium butyrate to the culture medium. For further maturation, hepatocyte growth factor and oncostatin M were added. The same differentiation protocol was applied to hiPSC maintained in 2D cultures. Secretion of alpha-fetoprotein (AFP), a marker for DE, was significantly (p < 0.05) higher in 2D cultures, while secretion of albumin, a typical characteristic for mature hepatocytes, was higher after hepatic differentiation of hiPSC in 3D bioreactors. Functional analysis of multiple cytochrome P450 (CYP) isoenzymes showed activity of CYP1A2, CYP2B6, and CYP3A4 in both groups, although at a lower level compared to primary human hepatocytes (PHH). CYP2B6 activities were significantly (p < 0.05) higher in 3D bioreactors compared with 2D cultures, which is in line with results from gene expression. Immunofluorescence staining showed that the majority of cells was positive for albumin, cytokeratin 18 (CK18), and hepatocyte nuclear factor 4-alpha (HNF4A) at the end of the differentiation process. In addition, cytokeratin 19 (CK19) staining revealed the formation of bile duct-like structures in 3D bioreactors similar to native liver tissue. The results indicate a better maturation of hiPSC in the 3D bioreactor system compared to 2D cultures and emphasize the potential of dynamic 3D culture systems

  15. Polyamines in human breast milk for preterm and term infants.

    PubMed

    Plaza-Zamora, J; Sabater-Molina, M; Rodríguez-Palmero, M; Rivero, M; Bosch, V; Nadal, J M; Zamora, S; Larqué, E

    2013-08-28

    Maternal milk is the first source of exogenous polyamines for the newborn. Polyamines modulate gut maturation in neonates, but no studies are available on polyamine concentration in human milk of preterm babies, even though they could be important for their immature gut. The present study aimed to determine polyamine concentration in human breast milk of mothers with preterm or term infants during the first month of lactation. Human milk samples were obtained during the first month of lactation from twenty-seven mothers with preterm babies and twelve mothers with babies born at term. The polyamine concentration in human milk was quantified by HPLC. During the first month of lactation, the total polyamine concentration was significantly higher in preterm milk than in term milk samples (7590 (SD 4990) v. 4660 (SD 4830) nmol/l, respectively (P ¼ 0·034)), as well as individual polyamine concentrations. Polyamine concentration in mature milk for preterm babies was significantly higher than that in mature milk for babies at term, and a similar trend was observed in colostrum and transition human milk. The spermidine/spermine ratio was higher in transition milk in preterm v. term samples, while in mature milk, the ratio was significantly lower in preterm than in term babies. In conclusion, the polyamine concentration was significantly higher in human milk for preterm than for term infants. This and the different spermidine/spermine ratios could influence the gut development of premature babies. PMID:23286699

  16. MR Assessment of Myocardial Perfusion, Viability, and Function after Intramyocardial Transfer of VM202, a New Plasmid Human Hepatocyte Growth Factor in Ischemic Swine Myocardium1

    PubMed Central

    Saeed, Maythem; Martin, Alastair; Ursell, Phillip; Do, Loi; Bucknor, Matt; Higgins, Charles B.; Saloner, David

    2008-01-01

    Purpose: VM202, a newly constructed plasmid human hepatocyte growth factor, was transferred intramyocardially after infarction for the purpose of evaluating this strategy as a therapeutic approach for protection from left ventricular (LV) remodeling. Materials and Methods: The institutional animal care and use committee approved this study. Pigs underwent coronary artery occlusion and reperfusion and served as either control (n = 8) or VM202-treated (n = 8) animals. VM202 was transferred intramyocardially into four infarcted and four periinfarcted sites. Cardiac magnetic resonance (MR) imaging (cine, perfusion, delayed enhancement) was performed in acute (3 days) and chronic (50 days ± 3 [standard error of the mean]) infarction. Histopathologic findings were used to characterize and quantify neovascularization. The t test was utilized to compare treated and control groups and to assess changes over time. Results: In acute infarction, MR imaging estimates of function, perfusion, and viability showed no difference between the groups. In chronic infarction, however, VM202 increased maximum signal intensity and upslope at first-pass perfusion imaging and reduced infarct size at perfusion and delayed-enhancement imaging. These changes were associated with a decrease in end-diastolic (2.15 mL/kg ± 0.12 to 1.73 mL/kg ± 0.10, P < .01) and end-systolic (1.33 mL/kg ± 0.07 to 0.92 mL/kg ± 0.08, P < .001) volumes and an increase in ejection fraction (38.2% ± 1.3 to 47.0% ± 1.8, P < .001). In contrast, LV function deteriorated further in control animals. Compared with control animals, VM202-treated animals revealed peninsulas and/or islands of viable myocardium in infarcted and periinfarcted regions and greater number of capillaries (218 per square millimeter ± 19 vs 119 per square millimeter ± 17, P < .05) and arterioles (21 per square millimeter ± 4 vs 3 per square millimeter ± 1, P < .001). Conclusion: Intramyocardial transfer of VM202 improved myocardial

  17. Human Rights and the Law-Terms to Know.

    ERIC Educational Resources Information Center

    Update on Law-Related Education, 1998

    1998-01-01

    Identifies 10 terms on human rights and the law that have been introduced and discussed throughout this issue of "Update on Law-Related Education." Offers students a chance to match each item to its definition by writing the letter of the terms on the line next to the number of the definition. (CMK)

  18. Human islet isolation--a prospective randomized comparison of pancreatic vascular perfusion with hyperosmolar citrate or University of Wisconsin solution.

    PubMed

    Robertson, G S; Chadwick, D; Thirdborough, S; Swift, S; Davies, J; James, R; Bell, P R; London, N J

    1993-09-01

    University of Wisconsin solution has become the most commonly used vascular perfusate during multiorgan donation world-wide. In the UK however, hyperosmolar citrate remains in common use. The purpose of this prospective randomized study was to compare the effect of systemic perfusion with UW or HOC on subsequent islet yield and purification for pancreata with short cold ischemic times. Seven pancreata were randomized to each group, with the donor age, pancreas weight, and period of cold ischemia being similar in both. Perfusion with UW was shown to inhibit collagenase digestion, and a higher concentration of this enzyme was needed to achieve comparable numbers of islets with good separation of exocrine and islet tissue after a similar period of digestion. There were no differences in the number, size, purity, or viability of islets between the two groups. In conclusion, UW solution offers no benefits over HOC for pancreata with short cold ischemic times, and because of its expense and need to use greater amounts of collagenase enzyme, we continue to use HOC. PMID:8212148

  19. Cerebral hemodynamics in human acute ischemic stroke: a study with diffusion- and perfusion-weighted magnetic resonance imaging and SPECT.

    PubMed

    Liu, Y; Karonen, J O; Vanninen, R L; Ostergaard, L; Roivainen, R; Nuutinen, J; Perkiö, J; Könönen, M; Hämäläinen, A; Vanninen, E J; Soimakallio, S; Kuikka, J T; Aronen, H J

    2000-06-01

    Nineteen patients with acute ischemic stroke (<24 hours) underwent diffusion-weighted and perfusion-weighted (PWI) magnetic resonance imaging at the acute stage and 1 week later. Eleven patients also underwent technetium-99m ethyl cysteinate dimer single-photon emission computed tomography (SPECT) at the acute stage. Relative (ischemic vs. contralateral control) cerebral blood flow (relCBF), relative cerebral blood volume, and relative mean transit time were measured in the ischemic core, in the area of infarct growth, and in the eventually viable ischemic tissue on PWI maps. The relCBF was also measured from SPECT. There was a curvilinear relationship between the relCBF measured from PWI and SPECT (r = 0.854; P < 0.001). The tissue proceeding to infarction during the follow-up had significantly lower initial CBF and cerebral blood volume values on PWI maps (P < 0.001) than the eventually viable ischemic tissue had. The best value for discriminating the area of infarct growth from the eventually viable ischemic tissue was 48% for PWI relCBF and 87% for PWI relative cerebral blood volume. Combined diffusion and perfusion-weighted imaging enables one to detect hemodynamically different subregions inside the initial perfusion abnormality. Tissue survival may be different in these subregions and may be predicted. PMID:10894174

  20. Creation of an ensemble of simulated cardiac cases and a human observer study: tools for the development of numerical observers for SPECT myocardial perfusion imaging

    NASA Astrophysics Data System (ADS)

    O'Connor, J. Michael; Pretorius, P. Hendrik; Gifford, Howard C.; Licho, Robert; Joffe, Samuel; McGuiness, Matthew; Mehurg, Shannon; Zacharias, Michael; Brankov, Jovan G.

    2012-02-01

    Our previous Single Photon Emission Computed Tomography (SPECT) myocardial perfusion imaging (MPI) research explored the utility of numerical observers. We recently created two hundred and eighty simulated SPECT cardiac cases using Dynamic MCAT (DMCAT) and SIMIND Monte Carlo tools. All simulated cases were then processed with two reconstruction methods: iterative ordered subset expectation maximization (OSEM) and filtered back-projection (FBP). Observer study sets were assembled for both OSEM and FBP methods. Five physicians performed an observer study on one hundred and seventy-nine images from the simulated cases. The observer task was to indicate detection of any myocardial perfusion defect using the American Society of Nuclear Cardiology (ASNC) 17-segment cardiac model and the ASNC five-scale rating guidelines. Human observer Receiver Operating Characteristic (ROC) studies established the guidelines for the subsequent evaluation of numerical model observer (NO) performance. Several NOs were formulated and their performance was compared with the human observer performance. One type of NO was based on evaluation of a cardiac polar map that had been pre-processed using a gradient-magnitude watershed segmentation algorithm. The second type of NO was also based on analysis of a cardiac polar map but with use of a priori calculated average image derived from an ensemble of normal cases.

  1. A perfusion chamber developed to investigate platelet interaction in flowing blood with human vessel wall cells, their extracellular matrix, and purified components.

    PubMed

    Sakariassen, K S; Aarts, P A; de Groot, P G; Houdijk, W P; Sixma, J J

    1983-10-01

    A flat perfusion chamber was developed to study the interaction of blood platelets in flowing blood with cultured human vessel wall cells, their connective tissue matrix, and isolated connective tissue components at defined shear rate conditions. A cover slip covered with endothelial cells or extracellular matrix components was introduced into the chamber. Laser-Doppler velocimetry showed a symmetrical flow profile at flow rates between 50 and 150 ml/min (wall shear rate 300 to 1100 sec-1). Platelet deposition was estimated by using blood platelets labeled with indium-111 or by a morphometric method. Blood platelets did not adhere to endothelial cells at wall shear rates of 765 sec-1 and the endothelial cells remained attached for at least 10 min of perfusion. In preconfluent cultures of endothelial cells, blood platelets adhered to extracellular material in areas between the cells. Removal of endothelial cells by treatment with 0.5% Triton X-100 induced increased platelet adherence with a preference for certain, as yet unidentified, fibrillar structures of the extracellular matrix. Platelet adherence to equine collagen was also studied after coating the cover slips by spraying of small collagen droplets followed by air drying. Platelet adherence and the subsequent platelet aggregate formation occurred predominantly along visible collagen fibers. These studies showed that this perfusion chamber has a laminar and symmetrical flow allowing qualitative and quantitative investigation of platelet interaction with endothelial cells, their extracellular matrix, and pure connective tissue components. A variety of wall shear rates and exposure times can be applied at controlled conditions without removing cells or extracellular material. PMID:6619647

  2. Quantification of absolute myocardial perfusion at rest and during exercise with positron emission tomography after human cardiac transplantation.

    PubMed

    Krivokapich, J; Stevenson, L W; Kobashigawa, J; Huang, S C; Schelbert, H R

    1991-08-01

    The maximal exercise capacity of cardiac transplant recipients is reduced compared with that of normal subjects. To determine if this reduced exercise capacity is related to inadequate myocardial perfusion during exercise, myocardial perfusion was measured noninvasively with use of positron emission tomography and nitrogen (N)-13 ammonia. Twelve transplant recipients with no angiographic evidence of accelerated coronary atherosclerosis were studied. Serial N-13 ammonia imaging was performed at rest and during supine bicycle exercise. The results were compared with those from 10 normal volunteers with a low probability of having cardiac disease. A two-compartment kinetic model for estimating myocardial perfusion was applied to the data. Transplant recipients achieved a significant lower exercise work load than did the volunteers (42 +/- 16 vs. 128 +/- 22 W), but a higher venous lactate concentration (31.3 +/- 14.9 vs. 13.7 +/- 4.1 mg/100 ml). Despite the difference in exercise work load, there was no significant difference in the cardiac work achieved by transplant recipients and normal subjects as evidenced by similar rate-pressure products of 24,000 +/- 3,400 versus 21,300 +/- 2,800 betas/min per mm Hg, respectively. In addition, myocardial blood flow during exercise was not significantly different between the two groups (1.70 +/- 0.60 vs. 1.56 +/- 0.71 ml/min per g, respectively). This study demonstrates that the myocardial flow response to the physiologic stress of exercise is appropriate in transplant recipients and does not appear to explain the decreased exercise capacity in these patients. PMID:1856420

  3. Quantification of absolute myocardial perfusion at rest and during exercise with positron emission tomography after human cardiac transplantation

    SciTech Connect

    Krivokapich, J.; Stevenson, L.W.; Kobashigawa, J.; Huang, S.C.; Schelbert, H.R. )

    1991-08-01

    The maximal exercise capacity of cardiac transplant recipients is reduced compared with that of normal subjects. To determine if this reduced exercise capacity is related to inadequate myocardial perfusion during exercise, myocardial perfusion was measured noninvasively with use of positron emission tomography and nitrogen (N)-13 ammonia. Twelve transplant recipients with no angiographic evidence of accelerated coronary atherosclerosis were studied. Serial N-13 ammonia imaging was performed at rest and during supine bicycle exercise. The results were compared with those from 10 normal volunteers with a low probability of having cardiac disease. A two-compartment kinetic model for estimating myocardial perfusion was applied to the data. Transplant recipients achieved a significant lower exercise work load than did the volunteers (42 {plus minus} 16 vs. 128 {plus minus} 22 W), but a higher venous lactate concentration (31.3 {plus minus} 14.9 vs. 13.7 {plus minus} 4.1 mg/100 ml). Despite the difference in exercise work load, there was no significant difference in the cardiac work achieved by transplant recipients and normal subjects as evidenced by similar rate-pressure products of 24,000 {plus minus} 3,400 versus 21,300 {plus minus} 2,800 betas/min per mm Hg, respectively. In addition, myocardial blood flow during exercise was not significantly different between the two groups (1.70 {plus minus} 0.60 vs. 1.56 {plus minus} 0.71 ml/min per g, respectively). This study demonstrates that the myocardial flow response to the physiologic stress of exercise is appropriate in transplant recipients and does not appear to explain the decreased exercise capacity in these patients.

  4. Disturbances in the cerebral perfusion of human immune deficiency virus-1 seropositive asymptomatic subjects: A quantitative tomography study of 18 cases

    SciTech Connect

    Tran Dinh, Y.R.; Mamo, H.; Cervoni, J.; Caulin, C.; Saimot, A.C. , Paris )

    1990-10-01

    Quantitative measurements of cerebral blood flow (CBF) by xenon-133 ({sup 133}Xe) tomography, together with magnetic resonance imaging (MRI), electroencephalography (EEG), psychometric tests, and laboratory analyses were performed on 18 human immunodeficiency virus 1 (HIV-1) seropositive asymptomatic subjects. Abnormalities of cerebral perfusion were observed in 16 cases (88%). These abnormalities were particularly frequent in the frontal regions (77% of cases). MRI demonstrated leucoencephalopathy in only two cases. EEG showed only induced diffuse abnormalities in two cases. Psychometric tests showed restricted moderate disturbances in 55% of patients. These disturbances mostly concerned those sectors involved in cognitive functions and memorization. These results indicate that quantitative measurements of CBF by {sup 133}Xe-SPECT is capable of detecting abnormalities of cerebral perfusion at a very early stage (Phase II) of HIV-1 infection. These abnormalities are indications of disturbances resulting from unidentified metabolic or vascular lesions. This technique appears to be superior to MRI at this stage of the disease's development. It could provide objective information leading to earlier treatment, and prove useful in evaluating potential antiviral chemotherapy.

  5. Kidneys From α1,3-Galactosyltransferase Knockout/Human Heme Oxygenase-1/Human A20 Transgenic Pigs Are Protected From Rejection During Ex Vivo Perfusion With Human Blood

    PubMed Central

    Ahrens, Hellen E.; Petersen, Björn; Ramackers, Wolf; Petkov, Stoyan; Herrmann, Doris; Hauschild-Quintern, Janet; Lucas-Hahn, Andrea; Hassel, Petra; Ziegler, Maren; Baars, Wiebke; Bergmann, Sabine; Schwinzer, Reinhard; Winkler, Michael; Niemann, Heiner

    2015-01-01

    Background Multiple modifications of the porcine genome are required to prevent rejection after pig-to-primate xenotransplantation. Here, we produced pigs with a knockout of the α1,3-galactosyltransferase gene (GGTA1-KO) combined with transgenic expression of the human anti-apoptotic/anti-inflammatory molecules heme oxygenase-1 and A20, and investigated their xenoprotective properties. Methods The GGTA1-KO/human heme oxygenase-1 (hHO-1)/human A20 (hA20) transgenic pigs were produced in a stepwise approach using zinc finger nuclease vectors targeting the GGTA1 gene and a Sleeping Beauty vector coding for hA20. Two piglets were analyzed by quantitative reverse-transcription polymerase chain reaction, flow cytometry, and sequencing. The biological function of the genetic modifications was tested in a 51Chromium release assay and by ex vivo kidney perfusions with human blood. Results Disruption of the GGTA1 gene by deletion of few basepairs was demonstrated in GGTA1-KO/hHO-1/hA20 transgenic pigs. The hHO-1 and hA20 mRNA expression was confirmed by quantitative reverse-transcription polymerase chain reaction. Ex vivo perfusion of 2 transgenic kidneys was feasible for the maximum experimental time of 240 minutes without symptoms of rejection. Conclusions Results indicate that GGTA1-KO/hHO-1/hA20 transgenic pigs are a promising model to alleviate rejection and ischemia-reperfusion damage in porcine xenografts and could serve as a background for further genetic modifications toward the production of a donor pig that is clinically relevant for xenotransplantation.

  6. Pulmonary ventilation/perfusion scan

    MedlinePlus

    V/Q scan; Ventilation/perfusion scan; Lung ventilation/perfusion scan ... A pulmonary ventilation/perfusion scan is actually two tests. They may be done separately or together. During the perfusion scan, a health ...

  7. Noninvasive estimation of oxygen consumption in human calf muscle through combined NMR measurements of ASL perfusion and T₂ oxymetry.

    PubMed

    Decorte, Nicolas; Buehler, Tania; Caldas de Almeida Araujo, Ericky; Vignaud, Alexandre; Carlier, Pierre G

    2014-01-01

    The objective of this work was to demonstrate the feasibility of measuring muscle O2 consumption (V˙O2) noninvasively with a combination of functional nuclear magnetic resonance (NMR) imaging methods, and to verify that changes in muscle V˙O2 can be detected with a temporal resolution compatible with physiological investigation and patient ease. T2-based oxymetry of arterial and venous blood was combined with the arterial-spin labeling (ASL)-based determination of muscle perfusion. These measurements were performed on 8 healthy volunteers under normoxic and hypoxic conditions in order to assess the sensitivity of measurements over a range of saturation values. Blood samples were drawn simultaneously and used to titrate blood T2 measurements versus hemoglobin O2 saturation (%HbO2) in vitro. The in vitro calibration curve of blood T2 fitted very well with the %HbO2 (r(2): 0.95). The in vivo venous T2 measurements agreed well with the in vitro measurements (intraclass correlation coefficient 0.82, 95% confidence interval 0.61-0.91). Oxygen extraction at rest decreased in the calf muscles subjected to hypoxia (p = 0.031). The combination of unaltered muscle perfusion and pinched arteriovenous O2 difference (p = 0.038) pointed towards a reduced calf muscle V˙O2 during transient hypoxia (p = 0.018). The results of this pilot study confirmed that muscle O2 extraction and V˙O2 can be estimated noninvasively using a combination of functional NMR techniques. Further studies are needed to confirm the usefulness in a larger sample of volunteers and patients. PMID:25531648

  8. Surgical treatment of acute myocardial ischaemia related to coronary angioplasty with special reference to use of perfusion balloon catheter and long-term outcome.

    PubMed

    Heikkinen, L; Virtanen, K; Heikkila, J; Verkkala, K; Salo, J; Jarvinen, A

    1997-04-01

    Twenty of 569 consecutive patients (3.5%) undergoing percutaneous transluminal coronary angioplasty required emergency coronary artery bypass grafting for acute closure of the dilated vessel. In seven patients an intracoronary autoperfusion balloon catheter was inserted to ensure antegrade blood flow across the injured zone of the coronary artery. The time needed for completion of the bypass grafts ranged from 100 to 399 minutes (mean 180 minutes). An average of 1.9 coronary artery bypasses was inserted. In total, 11 of the 20 patients (55%) developed new Q waves and had elevated CK-MB levels. However, the myocardial infarction rate was only 14% in those with a perfusion balloon catheter as against 77% in those without one. The insertion of a ball-out catheter permitted greater utilization of the internal mammary artery as a bypass graft. Angiographic follow-up was conducted after a mean of 28 months (19 patients). The patency rate of the bypass grafts placed in the emergency setting was relatively good (91%). Thallium tomography revealed a scar of variable size in all 17 patients studied and a reversible exercise perfusion defect requiring coronary reangioplasty in three patients. In conclusion, the insertion of a perfusion balloon catheter after abrupt coronary occlusion during coronary angioplasty solved the problems of acute myocardial ischemia and markedly lowered the definite myocardial infarction rate. This technique ensures favourable haemodynamic conditions for emergency myocardial revascularization. PMID:9201117

  9. The Evolution of Human Cells in Terms of Protein Innovation

    PubMed Central

    Sardar, Adam J.; Oates, Matt E.; Fang, Hai; Forrest, Alistair R.R.; Kawaji, Hideya; Gough, Julian; Rackham, Owen J.L.

    2014-01-01

    Humans are composed of hundreds of cell types. As the genomic DNA of each somatic cell is identical, cell type is determined by what is expressed and when. Until recently, little has been reported about the determinants of human cell identity, particularly from the joint perspective of gene evolution and expression. Here, we chart the evolutionary past of all documented human cell types via the collective histories of proteins, the principal product of gene expression. FANTOM5 data provide cell-type–specific digital expression of human protein-coding genes and the SUPERFAMILY resource is used to provide protein domain annotation. The evolutionary epoch in which each protein was created is inferred by comparison with domain annotation of all other completely sequenced genomes. Studying the distribution across epochs of genes expressed in each cell type reveals insights into human cellular evolution in terms of protein innovation. For each cell type, its history of protein innovation is charted based on the genes it expresses. Combining the histories of all cell types enables us to create a timeline of cell evolution. This timeline identifies the possibility that our common ancestor Coelomata (cavity-forming animals) provided the innovation required for the innate immune system, whereas cells which now form the brain of human have followed a trajectory of continually accumulating novel proteins since Opisthokonta (boundary of animals and fungi). We conclude that exaptation of existing domain architectures into new contexts is the dominant source of cell-type–specific domain architectures. PMID:24692656

  10. Survival probability of human conceptions from fertilization to term.

    PubMed

    Boklage, C E

    1990-01-01

    Preterm death of the human conceptus is common. A consistent biphasic pattern in the rate of loss from biochemical pregnancy detection to term suggests that most wastage occurs prior to clinical recognition. After simple adjustments for varying methods, existing data show that at least 73% of natural single conceptions have no real chance of surviving 6 weeks of gestation. Of the remainder, about 90% will survive to term. IVF conceptions do nearly as well as natural pregnancies after clinical recognition, but poorly before, despite selecting apparently normal embryos for transfer. Reasons may lie in the uterus more than the embryo itself. Multiple pregnancies may constitute more than 12% of all natural conceptions, of which number about 2% survive to term as twins and about 12% result in single births. In all of these situations, simple equations for exponential decay in a mixture of two populations can accurately describe the distribution of those deaths in time. PMID:1970983

  11. Developing a tissue perfusion sensor.

    PubMed

    Harvey, S L R; Parker, K H; O'Hare, D

    2007-01-01

    The development of a electrochemical tissue perfusion sensor is presented. The sensor is a platinum/platinum ring-disc microelectrode that relies on the principle of collector-generator to monitor mass transport within its vicinity. Tissue perfusion is a mass transport mechanism that describes the movement of respiratory gases, nutrients and metabolites in tissue. The sensor's capability of detecting perfusion at the cellular level in a continuous fashion is unique. This sensor will provide insight into the way nutrients and metabolites are transported in tissue especially in cases were perfusion is low such as in wounds or ischemic tissue. We present experimental work for the development and testing of the sensors in vitro. Experimental flow recordings in free steam solutions as well as the flow through tissue-like media are shown. Tests on post operative human tissue are also presented. The sensor's feature such as the continuous recoding capacities, spatial resolution and the measurement range from ml/min to microl/min are highlighted. PMID:18002549

  12. Ventilation-perfusion inequality in the human lung is not increased following no-decompression-stop hyperbaric exposure.

    PubMed

    Moore, Gaea Schwaebe; Wong, Stewart C; Darquenne, Chantal; Neuman, Tom S; West, John B; Kim Prisk, G

    2009-11-01

    Venous gas bubbles occur in recreational SCUBA divers in the absence of decompression sickness, forming venous gas emboli (VGE) which are trapped within pulmonary circulation and cleared by the lung without overt pathology. We hypothesized that asymptomatic VGE would transiently increase ventilation-perfusion mismatch due to their occlusive effects within the pulmonary circulation. Two sets of healthy volunteers (n = 11, n = 12) were recruited to test this hypothesis with a single recreational ocean dive or a baro-equivalent dry hyperbaric dive. Pulmonary studies (intrabreath V (A)/Q (iV/Q), alveolar dead space, and FVC) were conducted at baseline and repeat 1- and 24-h after the exposure. Contrary to our hypothesis V (A)/Q mismatch was decreased 1-h post-SCUBA dive (iV/Q slope 0.023 +/- 0.008 ml(-1) at baseline vs. 0.010 +/- 0.005 NS), and was significantly reduced 24-h post-SCUBA dive (0.000 +/- 0.005, p < 0.05), with improved V (A)/Q homogeneity inversely correlated to dive severity. No changes in V (A)/Q mismatch were observed after the chamber dive. Alveolar dead space decreased 24-h post-SCUBA dive (78 +/- 10 ml at baseline vs. 56 +/- 5, p < 0.05), but not 1-h post dive. FVC rose 1-h post-SCUBA dive (5.01 +/- 0.18 l vs. 5.21 +/- 0.26, p < 0.05), remained elevated 24-h post SCUBA dive (5.06 +/- 0.2, p < 0.05), but was decreased 1-hr after the chamber dive (4.96 +/- 0.31 L to 4.87 +/- 0.32, p < 0.05). The degree of V (A)/Q mismatch in the lung was decreased following recreational ocean dives, and was unchanged following an equivalent air chamber dive, arguing against an impact of VGE on the pulmonary circulation. PMID:19690884

  13. Human cervicovaginal fluid biomarkers to predict term and preterm labor

    PubMed Central

    Heng, Yujing J.; Liong, Stella; Permezel, Michael; Rice, Gregory E.; Di Quinzio, Megan K. W.; Georgiou, Harry M.

    2015-01-01

    Preterm birth (PTB; birth before 37 completed weeks of gestation) remains the major cause of neonatal morbidity and mortality. The current generation of biomarkers predictive of PTB have limited utility. In pregnancy, the human cervicovaginal fluid (CVF) proteome is a reflection of the local biochemical milieu and is influenced by the physical changes occurring in the vagina, cervix and adjacent overlying fetal membranes. Term and preterm labor (PTL) share common pathways of cervical ripening, myometrial activation and fetal membranes rupture leading to birth. We therefore hypothesize that CVF biomarkers predictive of labor may be similar in both the term and preterm labor setting. In this review, we summarize some of the existing published literature as well as our team's breadth of work utilizing the CVF for the discovery and validation of putative CVF biomarkers predictive of human labor. Our team established an efficient method for collecting serial CVF samples for optimal 2-dimensional gel electrophoresis resolution and analysis. We first embarked on CVF biomarker discovery for the prediction of spontaneous onset of term labor using 2D-electrophoresis and solution array multiple analyte profiling. 2D-electrophoretic analyses were subsequently performed on CVF samples associated with PTB. Several proteins have been successfully validated and demonstrate that these biomarkers are associated with term and PTL and may be predictive of both term and PTL. In addition, the measurement of these putative biomarkers was found to be robust to the influences of vaginal microflora and/or semen. The future development of a multiple biomarker bed-side test would help improve the prediction of PTB and the clinical management of patients. PMID:26029118

  14. 37 CFR 1.775 - Calculation of patent term extension for a human drug, antibiotic drug or human biological product.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... extension for a human drug, antibiotic drug or human biological product. 1.775 Section 1.775 Patents... Review § 1.775 Calculation of patent term extension for a human drug, antibiotic drug or human biological... drug or human biological product is eligible for extension, the term shall be extended by the time...

  15. 37 CFR 1.775 - Calculation of patent term extension for a human drug, antibiotic drug or human biological product.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... extension for a human drug, antibiotic drug or human biological product. 1.775 Section 1.775 Patents... Review § 1.775 Calculation of patent term extension for a human drug, antibiotic drug or human biological... drug or human biological product is eligible for extension, the term shall be extended by the time...

  16. 37 CFR 1.775 - Calculation of patent term extension for a human drug, antibiotic drug or human biological product.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... extension for a human drug, antibiotic drug or human biological product. 1.775 Section 1.775 Patents... Review § 1.775 Calculation of patent term extension for a human drug, antibiotic drug or human biological... drug or human biological product is eligible for extension, the term shall be extended by the time...

  17. 37 CFR 1.775 - Calculation of patent term extension for a human drug, antibiotic drug or human biological product.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... extension for a human drug, antibiotic drug or human biological product. 1.775 Section 1.775 Patents... Review § 1.775 Calculation of patent term extension for a human drug, antibiotic drug or human biological... drug or human biological product is eligible for extension, the term shall be extended by the time...

  18. 37 CFR 1.775 - Calculation of patent term extension for a human drug, antibiotic drug or human biological product.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... extension for a human drug, antibiotic drug or human biological product. 1.775 Section 1.775 Patents... Review § 1.775 Calculation of patent term extension for a human drug, antibiotic drug or human biological... drug or human biological product is eligible for extension, the term shall be extended by the time...

  19. Lactoferrin Levels in Human Milk after Preterm and Term Delivery.

    PubMed

    Albenzio, Marzia; Santillo, Antonella; Stolfi, Ilaria; Manzoni, Paolo; Iliceto, Alice; Rinaldi, Matteo; Magaldi, Rosario

    2016-09-01

    Background Lactoferrin (LF) is a highly represented, functional glycoprotein in human milk, exerting a wide range of anti-infective, immunomodulatory, and prebiotic actions in the neonate. Limited data are available assessing the concentrations and levels of LF in maternal milk over time during lactation in mothers who delivered infants at different GAs. Our aim with the present study was to determine the levels of LF in human milk from mothers of preterm and term infants and to evaluate the variations at a different time from delivery, in colostrum and mature milk. Methods Mothers of preterm and term infants from the Neonatology Unit in Foggia, Italy, were approached and enrolled in this study. From each mother, milk samples were collected within the first 3 days after birth (group A, 0-72 hours), between the 5th and 7th day after delivery (group B, 120-168 hours), and after the 10th day (group C, > 240 hours). All milk samples were divided into five groups, according to the GA of the infants: 24 to 27.6 weeks of GA (I), 28 to 31.6 weeks of GA (II), 32 to 34.6 weeks of GA (III), 35 to 37.6 weeks of GA (IV), and > 38 weeks of GA (V). Milk samples were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis to determine the content of LF. Results A total of 84 milk samples were collected from 28 mothers. We found that infant's GA, as well as the time of sampling, affected the levels of LF in milk. On one hand, LF showed higher content in human milk from group I (GA: 24-27.6 weeks) compared with the other groups (p < 0.01), and the levels of LF in colostrum were significantly correlated with GA (r = -0.31; p < 0.05). On the other hand, the LF content of milk had a significant decreasing trend over time. Overall, the highest values of LF were detected in preterm infants' maternal milk with a baby birth weight, lower than 1,400 g. Approximately 350 µg/mL was identified as the mean, physiological LF content in human mature milk

  20. Endothelial cells derived from human iPSCs increase capillary density and improve perfusion in a mouse model of peripheral arterial disease

    PubMed Central

    Jalil, Rufaihah Abdul; Huang, Ngan F; Jame, Sina; Lee, Jerry; Nguyen, Ha N; Byers, Blake; De, Abhijit; Okogbaa, Janet; Rollins, Mark; Reijo-Pera, Renee; Gambhir, Sanjiv S; Cooke, John P

    2011-01-01

    Objective Stem cell therapy for angiogenesis and vascular regeneration has been investigated using adult or embryonic stem cells. In the present study, we investigated the potential of endothelial cells (ECs) derived from human induced pluripotent stem cells (hiPSCs) to promote the perfusion of ischemic tissue in a murine model of peripheral arterial disease. Methods and Results Endothelial differentiation was initiated by culturing hiPSCs for 14 days in differentiation media supplemented with BMP-4 and VEGF. The hiPSC-ECs exhibited endothelial characteristics by forming capillary-like structures in matrigel and incorporating acetylated-LDL. They stained positively for EC markers such as KDR, CD31, CD144 and eNOS. In vitro exposure of hiPSC-ECs to hypoxia resulted in increased expression of various angiogenic related cytokines and growth factors. hiPSC-ECs were stably transduced with a double fusion construct encoded by the ubiquitin promoter, firefly luciferase for bioluminescence imaging (BLI) and green fluorescence protein (GFP) for fluorescent detection (pUb-Fluc-GFP). The hiPSC-ECs (5×105) were delivered by intramuscular injection into the ischemic hindlimb of SCID mice at day 0 and again on day 7 after femoral artery ligation (n=8). BLI showed that hiPSC-ECs survived in the ischemic limb for at least 2 weeks. In addition, laser Doppler imaging showed that the ratio of blood perfusion was increased by hiPSC-EC treatment by comparison to the saline-treated group (0.58±0.12 vs 0.44±0.04; P=0.005). The total number of capillaries in the ischemic limb of mice receiving hiPSC-EC injections was greater than those in the saline-treated group (1284 ±155 vs. 797±206 capillaries/mm2) (P<0.002). Conclusion This study is a first step toward development of a regenerative strategy for peripheral arterial disease based on the use of ECs derived from hiPSCs. PMID:21836062

  1. Meta-analysis of the independent and cumulative effects of multiple genetic modifications on pig lung xenograft performance during ex vivo perfusion with human blood

    PubMed Central

    Harris, Donald G.; Quinn, Kevin J.; French, Beth M.; Schwartz, Evan; Kang, Elizabeth; Dahi, Siamak; Phelps, Carol J.; Ayares, David L.; Burdorf, Lars; Azimzadeh, Agnes M.; Pierson, Richard N.

    2014-01-01

    Background Genetically modified pigs are a promising potential source of lung xenografts. Ex-vivo xenoperfusion is an effective platform for testing the effect of new modifications, but typical experiments are limited by testing of a single genetic intervention and small sample sizes. The purpose of this study was to analyze the individual and aggregate effects of donor genetic modifications on porcine lung xenograft survival and injury in an extensive pig lung xenoperfusion series. Methods Data from 157 porcine lung xenoperfusion experiments using otherwise unmodified heparinized human blood were aggregated as either continuous or dichotomous variables. Lungs were wild type in 17 perfusions (11% of the study group), while 31 lungs (20% of the study group) had 1 genetic modification, 40 lungs (39%) had 2, and 47 lungs (30%) had 3 or more modifications. The primary endpoint was functional lung survival to 4 hours of perfusion. Secondary analyses evaluated previously identified markers associated with known lung xenograft injury mechanisms. In addition to comparison among all xenografts grouped by survival status, a subgroup analysis was performed of lungs incorporating the GalTKO.hCD46 genotype. Results Each increase in the number of genetic modifications was associated with additional prolongation of lung xenograft survival. Lungs that exhibited survival to 4 hours generally had reduced platelet activation and thrombin generation. GalTKO and the expression of hCD46, HO-1, hCD55 or hEPCR were associated with improved survival. hTBM, HLA-E, and hCD39 were associated with no significant effect on the primary outcome. Conclusion This meta-analysis of an extensive lung xenotransplantation series demonstrates that increasing the number of genetic modifications targeting known xenogeneic lung injury mechanisms is associated with incremental improvements in lung survival. While more detailed mechanistic studies are needed to explore the relationship between gene expression

  2. True versus mild hyperthermia during isolated hepatic perfusion: effects on melphalan pharmacokinetics and liver function.

    PubMed

    Pilati, Pierluigi; Mocellin, Simone; Rossi, Carlo R; Ori, Carlo; Innocente, Federico; Scalerta, Romano; Ceccherini, Mauro; Da Pian, Pier Paolo; Nitti, Donato; Lise, Mario

    2004-08-01

    Hyperthermic antiblastic isolated hepatic perfusion (IHP) with melphalan has been recently proposed as an alternative therapeutic option for patients with unresectable liver tumors. Although melphalan-heat antiblastic synergism is at a maximum at temperatures higher than 41 degrees C, IHP has so far been performed in humans at lower temperatures. In this experimental work, we compared IHP under mild versus true hyperthermic conditions in terms of drug pharmacokinetics and liver function. Ten pigs were submitted to IHP with melphalan 1.5 mg/kg at a mean temperature of 40 degrees C (group A, n = 5) or 42 degrees C (group B, n = 5). After a 60-minute perfusion, a 15-minute washout was performed. Perfusate-to-plasma leakage was monitored using scintigraphy. Throughout perfusion, samples from the systemic blood, perfusate, and liver parenchyma were obtained to measure melphalan concentrations. Liver function was assessed using standard blood tests and the indocyanine green-based test. No deaths related to the IHP procedure were recorded. All animals had transient liver function impairment, with all liver function test results returning to normal within the observation period. At histologic examination, liver damage was similar under both hyperthermic conditions. Melphalan levels in the perfusate were not significantly different in the two study groups (the mean perfusate/plasma area under the curve from 0 to 60 minutes ratios were 463 and 501, respectively). These results correlated well with those obtained using the scintigraphic method. Liver drug concentrations remained unchanged after true hyperthermia IHP. Under true hyperthermic conditions, neither an increase in liver parenchyma toxicity nor changes in melphalan pharmacokinetics were observed. These findings support the use of true hyperthermia in the clinical setting to exploit fully the antitumor synergism between melphalan and heat. PMID:15457357

  3. Logistic ex Vivo Lung Perfusion for Hyperimmunized Patients.

    PubMed

    De Wolf, Julien; Puyo, Philippe; Bonnette, Pierre; Roux, Antoine; Le Guen, Morgan; Parquin, François; Chapelier, Alain; Sage, Edouard

    2016-09-01

    Hyperimmunized patients have restricted access to lung transplantation because of the low rate of donor lung availability. Sensitization to human leukocyte antigen is associated with acute rejection, allograft dysfunction, and decreased survival. Prospective crossmatching could allow matching a lung graft with the recipient; however, such a strategy would increase graft ischemia, with a worse impact on the long-term results of lung transplantation. We used logistic ex vivo lung perfusion for 3 patients at the Foch Hospital while waiting for a negative result of the prospective crossmatching and then moved forward to lung transplantation. All patients are alive 3 years after bilateral lung transplantation. PMID:27549543

  4. Acute tumor vascular effects following fractionated radiotherapy in human lung cancer: In vivo whole tumor assessment using volumetric perfusion computed tomography

    SciTech Connect

    Ng, Q.-S.; Goh, Vicky; Milner, Jessica; Padhani, Anwar R.; Saunders, Michele I.; Hoskin, Peter J. . E-mail: peterhoskin@nhs.net

    2007-02-01

    Purpose: To quantitatively assess the in vivo acute vascular effects of fractionated radiotherapy for human non-small-cell lung cancer using volumetric perfusion computed tomography (CT). Methods and Materials: Sixteen patients with advanced non-small-cell lung cancer, undergoing palliative radiotherapy delivering 27 Gy in 6 fractions over 3 weeks, were scanned before treatment, and after the second (9 Gy), fourth (18 Gy), and sixth (27 Gy) radiation fraction. Using 16-detector CT, multiple sequential volumetric acquisitions were acquired after intravenous contrast agent injection. Measurements of vascular blood volume and permeability for the whole tumor volume were obtained. Vascular changes at the tumor periphery and center were also measured. Results: At baseline, lung tumor vascularity was spatially heterogeneous with the tumor rim showing a higher vascular blood volume and permeability than the center. After the second, fourth, and sixth fractions of radiotherapy, vascular blood volume increased by 31.6% (paired t test, p = 0.10), 49.3% (p = 0.034), and 44.6% (p = 0.0012) respectively at the tumor rim, and 16.4% (p = 0.29), 19.9% (p = 0.029), and 4.0% (p = 0.0050) respectively at the center of the tumor. After the second, fourth, and sixth fractions of radiotherapy, vessel permeability increased by 18.4% (p = 0.022), 44.8% (p = 0.0048), and 20.5% (p = 0.25) at the tumor rim. The increase in permeability at the tumor center was not significant after radiotherapy. Conclusion: Fractionated radiotherapy increases tumor vascular blood volume and permeability in human non-small-cell lung cancer. We have established the spatial distribution of vascular changes after radiotherapy; greater vascular changes were demonstrated at the tumor rim compared with the center.

  5. A Long-term Co-perfused Disseminated Tuberculosis-3D Liver Hollow Fiber Model for Both Drug Efficacy and Hepatotoxicity in Babies

    PubMed Central

    Srivastava, Shashikant; Pasipanodya, Jotam G.; Ramachandran, Geetha; Deshpande, Devyani; Shuford, Stephen; Crosswell, Howland E.; Cirrincione, Kayle N.; Sherman, Carleton M.; Swaminathan, Soumya; Gumbo, Tawanda

    2016-01-01

    Treatment of disseminated tuberculosis in children ≤ 6 years has not been optimized. The pyrazinamide-containing combination regimen used to treat disseminated tuberculosis in babies and toddlers was extrapolated from adult pulmonary tuberculosis. Due to hepatotoxicity worries, there are no dose–response studies in children. We designed a hollow fiber system model of disseminated intracellular tuberculosis with co-perfused three-dimensional organotypic liver modules to simultaneously test for efficacy and toxicity. We utilized pediatric pharmacokinetics of pyrazinamide and acetaminophen to determine dose-dependent pyrazinamide efficacy and hepatotoxicity. Acetaminophen concentrations that cause hepatotoxicity in children led to elevated liver function tests, while 100 mg/kg pyrazinamide did not. Surprisingly, pyrazinamide did not kill intracellular Mycobacterium tuberculosis up to fourfold the standard dose as monotherapy or as combination therapy, despite achieving high intracellular concentrations. Host-pathogen RNA-sequencing revealed lack of a pyrazinamide exposure transcript signature in intracellular bacteria or of phagolysosome acidification on pH imaging. Artificial intelligence algorithms confirmed that pyrazinamide was not predictive of good clinical outcomes in children ≤ 6 years who had extrapulmonary tuberculosis. Thus, adding a drug that works inside macrophages could benefit children with disseminated tuberculosis. Our in vitro model can be used to identify such new regimens that could accelerate cure while minimizing toxicity. PMID:27211555

  6. A Long-term Co-perfused Disseminated Tuberculosis-3D Liver Hollow Fiber Model for Both Drug Efficacy and Hepatotoxicity in Babies.

    PubMed

    Srivastava, Shashikant; Pasipanodya, Jotam G; Ramachandran, Geetha; Deshpande, Devyani; Shuford, Stephen; Crosswell, Howland E; Cirrincione, Kayle N; Sherman, Carleton M; Swaminathan, Soumya; Gumbo, Tawanda

    2016-04-01

    Treatment of disseminated tuberculosis in children≤6years has not been optimized. The pyrazinamide-containing combination regimen used to treat disseminated tuberculosis in babies and toddlers was extrapolated from adult pulmonary tuberculosis. Due to hepatotoxicity worries, there are no dose-response studies in children. We designed a hollow fiber system model of disseminated intracellular tuberculosis with co-perfused three-dimensional organotypic liver modules to simultaneously test for efficacy and toxicity. We utilized pediatric pharmacokinetics of pyrazinamide and acetaminophen to determine dose-dependent pyrazinamide efficacy and hepatotoxicity. Acetaminophen concentrations that cause hepatotoxicity in children led to elevated liver function tests, while 100mg/kg pyrazinamide did not. Surprisingly, pyrazinamide did not kill intracellular Mycobacterium tuberculosis up to fourfold the standard dose as monotherapy or as combination therapy, despite achieving high intracellular concentrations. Host-pathogen RNA-sequencing revealed lack of a pyrazinamide exposure transcript signature in intracellular bacteria or of phagolysosome acidification on pH imaging. Artificial intelligence algorithms confirmed that pyrazinamide was not predictive of good clinical outcomes in children≤6years who had extrapulmonary tuberculosis. Thus, adding a drug that works inside macrophages could benefit children with disseminated tuberculosis. Our in vitro model can be used to identify such new regimens that could accelerate cure while minimizing toxicity. PMID:27211555

  7. Short-term effects of recombinant human growth hormone and feeding on gluconeogenesis in humans

    Technology Transfer Automated Retrieval System (TEKTRAN)

    After a short-term fast, lactating women have increased rates of glucose production but not gluconeogenesis (GNG) despite relative hypoinsulinemia. We explored the effects of non-insulin-dependent increase in glucose utilization and recombinant human growth hormone (rhGH) on glucose production, glyc...

  8. Methodology for ventilation/perfusion SPECT.

    PubMed

    Bajc, Marika; Neilly, Brian; Miniati, Massimo; Mortensen, Jan; Jonson, Björn

    2010-11-01

    Ventilation/perfusion single-photon emission computed tomography (V/Q SPECT) is the scintigraphic technique of choice for the diagnosis of pulmonary embolism and many other disorders that affect lung function. Data from recent ventilation studies show that the theoretic advantages of Technegas over radiolabeled liquid aerosols are not restricted to the presence of obstructive lung disease. Radiolabeled macroaggregated human albumin is the imaging agent of choice for perfusion scintigraphy. An optimal combination of nuclide activities and acquisition times for ventilation and perfusion, collimators, and imaging matrix yields an adequate V/Q SPECT study in approximately 20 minutes of imaging time. The recommended protocol based on the patient remaining in an unchanged position during the initial ventilation study and the perfusion study allows presentation of matching ventilation and perfusion slices in all projections as well as in rotating volume images based upon maximum intensity projections. Probabilistic interpretation of V/Q SPECT should be replaced by a holistic interpretation strategy on the basis of all relevant information about the patient and all ventilation/perfusion patterns. PE is diagnosed when there is more than one subsegment showing a V/Q mismatch representing an anatomic lung unit. Apart from pulmonary embolism, other pathologies should be identified and reported, for example, obstructive disease, heart failure, and pneumonia. Pitfalls exist both with respect to imaging technique and scan interpretation. PMID:20920632

  9. Long-term efficacy and safety of human papillomavirus vaccination

    PubMed Central

    De Vincenzo, Rosa; Conte, Carmine; Ricci, Caterina; Scambia, Giovanni; Capelli, Giovanni

    2014-01-01

    In this paper, we review the published evidence about the long-term efficacy of the available human papillomavirus (HPV) vaccines and their safety profile. Two prophylactic HPV vaccines – bivalent (bHPV) and quadrivalent (qHPV) – are now available, and vaccination programs are being widely implemented, primarily targeting adolescent girls. Efficacy has been widely demonstrated for both vaccines. Since the risk of HPV exposure potentially persists throughout a woman’s sexual life, vaccine duration of protection is critical to overall effectiveness. Interpreting the results of long-term efficacy studies for the two HPV vaccines can be puzzling, due to the heterogeneity of studies, different methods used in the assessment of immunogenicity, histopathological and virological end points, and statistical power issues. Moreover, an immunologic correlate of protection has not yet been established, and it is unknown whether higher antibody levels will really result in a longer duration of protection. Disease prevention remains the most important measure of long-term duration of vaccine efficacy. To date, the longest follow-up of an HPV vaccine has been 9.4 years for the bHPV vaccine. Long-term follow-up for qHPV vaccine goes up to 8 years. The vaccine continues to be immunogenic and well tolerated up to 9 years following vaccination. All randomized controlled clinical trials of the bHPV and the qHPV vaccines provide evidence of an excellent safety profile. The most common complaint reported is pain in the injection site, which is self-limiting and spontaneously resolved. The incidence of systemic adverse events (AEs), serious AEs, and discontinuations due to a serious AE reported in clinical studies are similar between the two vaccines and their control groups. In particular, no increased risk of autoimmune disease has been shown among HPV-vaccinated subjects in long-term observation studies. As these are crucial topics in HPV vaccination, it is important to establish

  10. The Philippine medium-term plan for human development.

    PubMed

    1993-04-01

    This pamphlet lists some basic features of the 1993-98 Philippine Medium-Term Development Plan (goals, targets, strategies, and human resource development). The last page contains a table of human development indicators with the annual average for 1987-91 and annual targets during 1993-98. Statistical measures include specific indicators for health, nutrition, family planning, education, housing, and social welfare. The introduction urges all government units, nongovernmental organizations, and international donors to support the development plan in a united effort. The goals of the plan include enabling most of the population to meet basic minimum needs, providing a level of basic services to the more disadvantaged, and moving the productive capacity of human resources to a more competitive international arena. The expected accomplishments for 1998 include an increase in life expectancy to 67.0 years, a decrease in infant mortality to 49.4 per 1000 live births, a decline in the crude death rate to 6.3 per 1000 population, a decline in underweight children to 8.4%, an increase in per capita energy intake to 1977 kilocalories, an increase in the proportion of households with 100% adequate energy intake to 47.1%, an increase in literacy to 98%, higher school enrollments, an increase of housing units to satisfy 34% of the total housing need, and a large increase in the number of poor families receiving basic welfare services to 89%. Specific measures will be adopted to alleviate poverty and to promote equity. Social services will be targeted to the most vulnerable groups. Social safety nets for disaster or emergency relief will be developed and maintained. Public resources will be directed to the most disadvantaged regions, and support will be given for community housing efforts and use of traditional medicines and other indigenous resources. The homeless will receive social services for security of housing and welfare, and efforts will be made to reduce the number of

  11. Anatomical reconstructions of the human cardiac venous system using contrast-computed tomography of perfusion-fixed specimens.

    PubMed

    Spencer, Julianne; Fitch, Emily; Iaizzo, Paul A

    2013-01-01

    A detailed understanding of the complexity and relative variability within the human cardiac venous system is crucial for the development of cardiac devices that require access to these vessels. For example, cardiac venous anatomy is known to be one of the key limitations for the proper delivery of cardiac resynchronization therapy (CRT)(1) Therefore, the development of a database of anatomical parameters for human cardiac venous systems can aid in the design of CRT delivery devices to overcome such a limitation. In this research project, the anatomical parameters were obtained from 3D reconstructions of the venous system using contrast-computed tomography (CT) imaging and modeling software (Materialise, Leuven, Belgium). The following parameters were assessed for each vein: arc length, tortuousity, branching angle, distance to the coronary sinus ostium, and vessel diameter. CRT is a potential treatment for patients with electromechanical dyssynchrony. Approximately 10-20% of heart failure patients may benefit from CRT(2). Electromechanical dyssynchrony implies that parts of the myocardium activate and contract earlier or later than the normal conduction pathway of the heart. In CRT, dyssynchronous areas of the myocardium are treated with electrical stimulation. CRT pacing typically involves pacing leads that stimulate the right atrium (RA), right ventricle (RV), and left ventricle (LV) to produce more resynchronized rhythms. The LV lead is typically implanted within a cardiac vein, with the aim to overlay it within the site of latest myocardial activation. We believe that the models obtained and the analyses thereof will promote the anatomical education for patients, students, clinicians, and medical device designers. The methodologies employed here can also be utilized to study other anatomical features of our human heart specimens, such as the coronary arteries. To further encourage the educational value of this research, we have shared the venous models on our

  12. In Vitro Model for Hepatotoxicity Studies Based on Primary Human Hepatocyte Cultivation in a Perfused 3D Bioreactor System

    PubMed Central

    Knöspel, Fanny; Jacobs, Frank; Freyer, Nora; Damm, Georg; De Bondt, An; van den Wyngaert, Ilse; Snoeys, Jan; Monshouwer, Mario; Richter, Marco; Strahl, Nadja; Seehofer, Daniel; Zeilinger, Katrin

    2016-01-01

    Accurate prediction of the potential hepatotoxic nature of new pharmaceuticals remains highly challenging. Therefore, novel in vitro models with improved external validity are needed to investigate hepatic metabolism and timely identify any toxicity of drugs in humans. In this study, we examined the effects of diclofenac, as a model substance with a known risk of hepatotoxicity in vivo, in a dynamic multi-compartment bioreactor using primary human liver cells. Biotransformation pathways of the drug and possible effects on metabolic activities, morphology and cell transcriptome were evaluated. Formation rates of diclofenac metabolites were relatively stable over the application period of seven days in bioreactors exposed to 300 µM diclofenac (300 µM bioreactors (300 µM BR)), while in bioreactors exposed to 1000 µM diclofenac (1000 µM BR) metabolite concentrations declined drastically. The biochemical data showed a significant decrease in lactate production and for the higher dose a significant increase in ammonia secretion, indicating a dose-dependent effect of diclofenac application. The microarray analyses performed revealed a stable hepatic phenotype of the cells over time and the observed transcriptional changes were in line with functional readouts of the system. In conclusion, the data highlight the suitability of the bioreactor technology for studying the hepatotoxicity of drugs in vitro. PMID:27092500

  13. Task-based evaluation of a 4D MAP-RBI-EM image reconstruction method for gated myocardial perfusion SPECT using a human observer study

    NASA Astrophysics Data System (ADS)

    Lee, Taek-Soo; Higuchi, Takahiro; Lautamäki, Riikka; Bengel, Frank M.; Tsui, Benjamin M. W.

    2015-09-01

    We evaluated the performance of a new 4D image reconstruction method for improved 4D gated myocardial perfusion (MP) SPECT using a task-based human observer study. We used a realistic 4D NURBS-based Cardiac-Torso (NCAT) phantom that models cardiac beating motion. Half of the population was normal; the other half had a regional hypokinetic wall motion abnormality. Noise-free and noisy projection data with 16 gates/cardiac cycle were generated using an analytical projector that included the effects of attenuation, collimator-detector response, and scatter (ADS), and were reconstructed using the 3D FBP without and 3D OS-EM with ADS corrections followed by different cut-off frequencies of a 4D linear post-filter. A 4D iterative maximum a posteriori rescaled-block (MAP-RBI)-EM image reconstruction method with ADS corrections was also used to reconstruct the projection data using various values of the weighting factor for its prior. The trade-offs between bias and noise were represented by the normalized mean squared error (NMSE) and averaged normalized standard deviation (NSDav), respectively. They were used to select reasonable ranges of the reconstructed images for use in a human observer study. The observers were trained with the simulated cine images and were instructed to rate their confidence on the absence or presence of a motion defect on a continuous scale. We then applied receiver operating characteristic (ROC) analysis and used the area under the ROC curve (AUC) index. The results showed that significant differences in detection performance among the different NMSE-NSDav combinations were found and the optimal trade-off from optimized reconstruction parameters corresponded to a maximum AUC value. The 4D MAP-RBI-EM with ADS correction, which had the best trade-off among the tested reconstruction methods, also had the highest AUC value, resulting in significantly better human observer detection performance when detecting regional myocardial wall motion

  14. Task-Based Evaluation of a 4D MAP-RBI-EM Image Reconstruction Method for Gated Myocardial Perfusion SPECT using a Human Observer Study

    PubMed Central

    Lee, Taek-Soo; Higuchi, Takahiro; Lautamäki, Riikka; Bengel, Frank M.; Tsui, Benjamin M. W.

    2015-01-01

    We evaluated the performance of a new 4D image reconstruction method for improved 4D gated myocardial perfusion (MP) SPECT using a task-based human observer study. We used a realistic 4D NURBS-based Cardiac-Torso (NCAT) phantom that models cardiac beating motion. Half of the population was normal; the other half had a regional hypokinetic wall motion abnormality. Noise-free and noisy projection data with 16 gates/cardiac cycle were generated using an analytical projector that included the effects of attenuation, collimator-detector response, and scatter (ADS), and were reconstructed using the 3D FBP without and 3D OS-EM with ADS corrections followed by different cut-off frequencies of a 4D linear post-filter. A 4D iterative maximum a posteriori rescaled-block (MAP-RBI)-EM image reconstruction method with ADS corrections was also used to reconstruct the projection data using various values of the weighting factor for its prior. The trade-offs between bias and noise were represented by the normalized mean squared error (NMSE) and averaged normalized standard deviation (NSDav), respectively. They were used to select reasonable ranges of the reconstructed images for use in a human observer study. The observers were trained with the simulated cine images and were instructed to rate their confidence on the absence or presence of a motion defect on a continuous scale. We then applied receiver operating characteristic (ROC) analysis and used the area under the ROC curve (AUC) index. The results showed that significant differences in detection performance among the different NMSE-NSDav combinations were found and the optimal trade-off from optimized reconstruction parameters corresponded to a maximum AUC value. The 4D MAP-RBI-EM with ADS correction, which had the best trade-off among the tested reconstruction methods, also had the highest AUC value, resulting in significantly better human observer detection performance when detecting regional myocardial wall motion

  15. Task-based evaluation of a 4D MAP-RBI-EM image reconstruction method for gated myocardial perfusion SPECT using a human observer study.

    PubMed

    Lee, Taek-Soo; Higuchi, Takahiro; Lautamäki, Riikka; Bengel, Frank M; Tsui, Benjamin M W

    2015-09-01

    We evaluated the performance of a new 4D image reconstruction method for improved 4D gated myocardial perfusion (MP) SPECT using a task-based human observer study. We used a realistic 4D NURBS-based Cardiac-Torso (NCAT) phantom that models cardiac beating motion. Half of the population was normal; the other half had a regional hypokinetic wall motion abnormality. Noise-free and noisy projection data with 16 gates/cardiac cycle were generated using an analytical projector that included the effects of attenuation, collimator-detector response, and scatter (ADS), and were reconstructed using the 3D FBP without and 3D OS-EM with ADS corrections followed by different cut-off frequencies of a 4D linear post-filter. A 4D iterative maximum a posteriori rescaled-block (MAP-RBI)-EM image reconstruction method with ADS corrections was also used to reconstruct the projection data using various values of the weighting factor for its prior. The trade-offs between bias and noise were represented by the normalized mean squared error (NMSE) and averaged normalized standard deviation (NSDav), respectively. They were used to select reasonable ranges of the reconstructed images for use in a human observer study. The observers were trained with the simulated cine images and were instructed to rate their confidence on the absence or presence of a motion defect on a continuous scale. We then applied receiver operating characteristic (ROC) analysis and used the area under the ROC curve (AUC) index. The results showed that significant differences in detection performance among the different NMSE-NSDav combinations were found and the optimal trade-off from optimized reconstruction parameters corresponded to a maximum AUC value. The 4D MAP-RBI-EM with ADS correction, which had the best trade-off among the tested reconstruction methods, also had the highest AUC value, resulting in significantly better human observer detection performance when detecting regional myocardial wall motion

  16. High-Pressure Transvenous Perfusion of the Upper Extremity in Human Muscular Dystrophy: A Safety Study with 0.9% Saline.

    PubMed

    Fan, Zheng; Kocis, Keith; Valley, Robert; Howard, James F; Chopra, Manisha; Chen, Yasheng; An, Hongyu; Lin, Weili; Muenzer, Joseph; Powers, William

    2015-09-01

    We evaluated safety and feasibility of high-pressure transvenous limb perfusion in an upper extremity of adult patients with muscular dystrophy, after completing a similar study in a lower extremity. A dose escalation study of single-limb perfusion with 0.9% saline was carried out in nine adults with muscular dystrophies under intravenous analgesia. Our study demonstrates that it is feasible and definitely safe to perform high-pressure transvenous perfusion with 0.9% saline up to 35% of limb volume in the upper extremities of young adults with muscular dystrophy. Perfusion at 40% limb volume is associated with short-lived physiological changes in peripheral nerves without clinical correlates in one subject. This study provides the basis for a phase 1/2 clinical trial using pressurized transvenous delivery into upper limbs of nonambulatory patients with Duchenne muscular dystrophy. Furthermore, our results are applicable to other conditions such as limb girdle muscular dystrophy as a method for delivering regional macromolecular therapeutics in high dose to skeletal muscles of the upper extremity. PMID:25953425

  17. Short-term potentiation of breathing in humans.

    PubMed

    Fregosi, R F

    1991-09-01

    The purpose of this study was to determine if the increase in ventilation induced by hypoxic stimulation of the carotid bodies (CB) persists after cessation of the stimulus in humans. I reasoned that a short-term potentiation (STP) of breathing, sometimes called an "afterdischarge," could be unmasked by combining hypoxia with exercise, because ventilation increases synergistically under these conditions. Seven young healthy men performed mild bicycle exercise (30% peak power) while breathing O2 for 1.5 min ("control" state), and their CB were then stimulated by 1.5 min of hypoxic exercise (10% O2--balance N2). CB stimulation was then terminated by changing the inspirate back to O2 as exercise continued. Inspiratory and expiratory duration (TI and TE) and inspiratory flow and its time integral [tidal volume (VT)] were measured with a pneumotachometer. Inspired minute ventilation (VI) and mean inspiratory flow (VT/TI) declined exponentially after the cessation of CB stimulation, with first-order time constants of 28.6 +/- 6.7 and 24.6 +/- 1.6 (SD) s, respectively. The slow decay of VI was due primarily to potentiation of both TI and TE, although the effect on the latter predominated. Additional experiments in six subjects showed that brief intense CB stimulation with four to five breaths of N2 during mild exercise induced STP of similar magnitude to that observed in the hypoxic exercise experiments. Finally, the imposition of hyperoxia during air breathing exercise at a level of respiratory drive similar to that induced by the hypoxic exercise did not change VI significantly.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1757326

  18. Expansion of Human Mesenchymal Stromal Cells from Fresh Bone Marrow in a 3D Scaffold-Based System under Direct Perfusion

    PubMed Central

    Brachat, Sophie; Braccini, Alessandra; Wendt, David; Barbero, Andrea; Jacobi, Carsten; Martin, Ivan

    2014-01-01

    Mesenchymal stromal/stem cell (MSC) expansion in conventional monolayer culture on plastic dishes (2D) leads to progressive loss of functionality and thus challenges fundamental studies on the physiology of skeletal progenitors, as well as translational applications for cellular therapy and molecular medicine. Here we demonstrate that 2D MSC expansion can be entirely bypassed by culturing freshly isolated bone marrow nucleated cells within 3D porous scaffolds in a perfusion-based bioreactor system. The 3D-perfusion system generated a stromal tissue that could be enzymatically treated to yield CD45- MSC. As compared to 2D-expanded MSC (control), those derived from 3D-perfusion culture after the same time (3 weeks) or a similar extent of proliferation (7–8 doublings) better maintained their progenitor properties, as assessed by a 4.3-fold higher clonogenicity and the superior differentiation capacity towards all typical mesenchymal lineages. Transcriptomic analysis of MSC from 5 donors validated the robustness of the process and indicated a reduced inter-donor variability and a significant upregulation of multipotency-related gene clusters following 3D-perfusion- as compared to 2D-expansion. Interestingly, the differences in functionality and transcriptomics between MSC expanded in 2D or under 3D-perfusion were only partially captured by cytofluorimetric analysis using conventional surface markers. The described system offers a multidisciplinary approach to study how factors of a 3D engineered niche regulate MSC function and, by streamlining conventional labor-intensive processes, is prone to automation and scalability within closed bioreactor systems. PMID:25020062

  19. Cardiac tissue engineering using perfusion bioreactor systems

    PubMed Central

    Radisic, Milica; Marsano, Anna; Maidhof, Robert; Wang, Yadong; Vunjak-Novakovic, Gordana

    2009-01-01

    This protocol describes tissue engineering of synchronously contractile cardiac constructs by culturing cardiac cell populations on porous scaffolds (in some cases with an array of channels) and bioreactors with perfusion of culture medium (in some cases supplemented with an oxygen carrier). The overall approach is ‘biomimetic’ in nature as it tends to provide in vivo-like oxygen supply to cultured cells and thereby overcome inherent limitations of diffusional transport in conventional culture systems. In order to mimic the capillary network, cells are cultured on channeled elastomer scaffolds that are perfused with culture medium that can contain oxygen carriers. The overall protocol takes 2–4 weeks, including assembly of the perfusion systems, preparation of scaffolds, cell seeding and cultivation, and on-line and end-point assessment methods. This model is well suited for a wide range of cardiac tissue engineering applications, including the use of human stem cells, and high-fidelity models for biological research. PMID:18388955

  20. The gravitational distribution of ventilation-perfusion ratio is more uniform in prone than supine posture in the normal human lung.

    PubMed

    Henderson, A Cortney; Sá, Rui Carlos; Theilmann, Rebecca J; Buxton, Richard B; Prisk, G Kim; Hopkins, Susan R

    2013-08-01

    The gravitational gradient of intrapleural pressure is suggested to be less in prone posture than supine. Thus the gravitational distribution of ventilation is expected to be more uniform prone, potentially affecting regional ventilation-perfusion (Va/Q) ratio. Using a novel functional lung magnetic resonance imaging technique to measure regional Va/Q ratio, the gravitational gradients in proton density, ventilation, perfusion, and Va/Q ratio were measured in prone and supine posture. Data were acquired in seven healthy subjects in a single sagittal slice of the right lung at functional residual capacity. Regional specific ventilation images quantified using specific ventilation imaging and proton density images obtained using a fast gradient-echo sequence were registered and smoothed to calculate regional alveolar ventilation. Perfusion was measured using arterial spin labeling. Ventilation (ml·min(-1)·ml(-1)) images were combined on a voxel-by-voxel basis with smoothed perfusion (ml·min(-1)·ml(-1)) images to obtain regional Va/Q ratio. Data were averaged for voxels within 1-cm gravitational planes, starting from the most gravitationally dependent lung. The slope of the relationship between alveolar ventilation and vertical height was less prone than supine (-0.17 ± 0.10 ml·min(-1)·ml(-1)·cm(-1) supine, -0.040 ± 0.03 prone ml·min(-1)·ml(-1)·cm(-1), P = 0.02) as was the slope of the perfusion-height relationship (-0.14 ± 0.05 ml·min(-1)·ml(-1)·cm(-1) supine, -0.08 ± 0.09 prone ml·min(-1)·ml(-1)·cm(-1), P = 0.02). There was a significant gravitational gradient in Va/Q ratio in both postures (P < 0.05) that was less in prone (0.09 ± 0.08 cm(-1) supine, 0.04 ± 0.03 cm(-1) prone, P = 0.04). The gravitational gradients in ventilation, perfusion, and regional Va/Q ratio were greater supine than prone, suggesting an interplay between thoracic cavity configuration, airway and vascular tree anatomy, and the effects of gravity on Va/Q matching. PMID

  1. Nifedipine and thallium-201 myocardial perfusion in progressive systemic sclerosis

    SciTech Connect

    Kahan, A.; Devaux, J.Y.; Amor, B.; Menkes, C.J.; Weber, S.; Nitenberg, A.; Venot, A.; Guerin, F.; Degeorges, M.; Roucayrol, J.C.

    1986-05-29

    Heart disease in patients with progressive systemic sclerosis may be due in part to myocardial ischemia caused by a disturbance of the coronary microcirculation. To determine whether abnormalities of myocardial perfusion in this disorder are potentially reversible, we evaluated the effect of the coronary vasodilator nifedipine on myocardial perfusion assessed by thallium-201 scanning in 20 patients. Thallium-201 single-photon-emission computerized tomography was performed under control conditions and 90 minutes after 20 mg of oral nifedipine. The mean (+/- SD) number of left ventricular segments with perfusion defects decreased from 5.3 +/- 2.0 to 3.3 +/- 2.2 after nifedipine (P = 0.0003). Perfusion abnormalities were quantified by a perfusion score (0 to 2.0) assigned to each left ventricular segment and by a global perfusion score (0 to 18) for the entire left ventricle. The mean perfusion score in segments with resting defects increased from 0.97 +/- 0.24 to 1.26 +/- 0.44 after nifedipine (P less than 0.00001). The mean global perfusion score increased from 11.2 +/- 1.7 to 12.8 +/- 2.4 after nifedipine (P = 0.003). The global perfusion score increased by at least 2.0 in 10 patients and decreased by at least 2.0 in only 1. These observations reveal short-term improvement in thallium-201 myocardial perfusion with nifedipine in patients with progressive systemic sclerosis. The results are consistent with a potentially reversible abnormality of coronary vasomotion in this disorder, but the long-term therapeutic effects of nifedipine remain to be determined.

  2. Importance of capillary perfusion.

    PubMed

    Hardaway, R M

    1979-11-01

    Perfusion is more critical than oxygen in the maintenance of cell viability. A high hematocrit or high fibrinogen level increases blood viscosity and predisposes to disseminated intravascular coagulation. It is recommended that a hematocrit of about 30 be maintained in periods of circulatory stress such as shock or extracorporeal circulation. PMID:495856

  3. Aspirate from human stented saphenous vein grafts induces epicardial coronary vasoconstriction and impairs perfusion and left ventricular function in rat bioassay hearts with pharmacologically induced endothelial dysfunction.

    PubMed

    Lieder, Helmut R; Baars, Theodor; Kahlert, Philipp; Kleinbongard, Petra

    2016-08-01

    Stent implantation into aortocoronary saphenous vein grafts (SVG) releases particulate debris and soluble vasoactive mediators, for example, serotonin. We now analyzed effects of the soluble mediators released into the coronary arterial blood during stent implantation on vasomotion of isolated rat epicardial coronary artery segments and on coronary flow and left ventricular developed pressure in isolated perfused rat hearts. Coronary blood was retrieved during percutaneous SVG intervention using a distal occlusion/aspiration protection device in nine symptomatic patients with stable angina pectoris and a flow-limiting SVG stenosis. The blood was separated into particulate debris and plasma. Responses to coronary plasma were determined in isolated rat epicardial coronary arteries and in isolated, constant pressure-perfused rat hearts (±nitric oxide synthase [NOS] inhibition and ±serotonin receptor blockade, respectively). Coronary aspirate plasma taken after stent implantation induced a stronger vasoconstriction of rat epicardial coronary arteries (52 ± 8% of maximal potassium chloride induced vasoconstriction [% KClmax = 100%]) than plasma taken before stent implantation (12 ± 8% of KClmax); NOS inhibition augmented this vasoconstrictor response (to 110 ± 15% and 24 ± 9% of KClmax). Coronary aspirate plasma taken after stent implantation reduced in isolated perfused rat hearts only under NOS inhibition coronary flow by 17 ± 3% and left ventricular developed pressure by 25 ± 4%. Blockade of serotonin receptors abrogated these effects. Coronary aspirate plasma taken after stent implantation induces vasoconstriction in isolated rat epicardial coronary arteries and reduces coronary flow and left ventricular developed pressure in isolated perfused rat hearts with pharmacologically induced endothelial dysfunction. PMID:27482071

  4. A long term model of circulation. [human body

    NASA Technical Reports Server (NTRS)

    White, R. J.

    1974-01-01

    A quantitative approach to modeling human physiological function, with a view toward ultimate application to long duration space flight experiments, was undertaken. Data was obtained on the effect of weightlessness on certain aspects of human physiological function during 1-3 month periods. Modifications in the Guyton model are reviewed. Design considerations for bilateral interface models are discussed. Construction of a functioning whole body model was studied, as well as the testing of the model versus available data.

  5. Contactless mapping of rhythmical phenomena in tissue perfusion using PPGI

    NASA Astrophysics Data System (ADS)

    Huelsbusch, Markus; Blazek, Vladimir

    2002-04-01

    This paper presents the experimental setup and preliminary results of a near infrared CCD camera based Photoplethysmography Imaging (PPGI) system, which has been shown to be suitable for contactless and spatially resolved assessment of rhythmical blood volume changes in the skin. To visualize the complex rhythmical patterns in the dermal perfusion the Wavelet Transform is utilized. It is able to jointly assess time and frequency behavior of signals and thus allows to analyze instationary oscillations and variabilities in the different human rhythmics. The presented system is expected to provide new insights into the functional sequences of physiological tissue perfusion as well as of the perfusion status in ulcer formation and wound healing.

  6. Space Resource Utilization: Near-Term Missions and Long-Term Plans for Human Exploration

    NASA Technical Reports Server (NTRS)

    Sanders, Gerald B.

    2015-01-01

    NASA's Human Exploration Plans: A primary goal of all major space faring nations is to explore space: from the Earth with telescopes, with robotic probes and space telescopes, and with humans. For the US National Aeronautics and Space Administration (NASA), this pursuit is captured in three important strategic goals: 1. Ascertain the content, origin, and evolution of the solar system and the potential for life elsewhere, 2. Extend and sustain human activities across the solar system (especially the surface of Mars), and 3. Create innovative new space technologies for exploration, science, and economic future. While specific missions and destinations are still being discussed as to what comes first, it is imperative for NASA that it foster the development and implementation of new technologies and approaches that make space exploration affordable and sustainable. Critical to achieving affordable and sustainable human exploration beyond low Earth orbit (LEO) is the development of technologies and systems to identify, extract, and use resources in space instead of bringing everything from Earth. To reduce the development and implementation costs for space resource utilization, often called In Situ Resource Utilization (ISRU), it is imperative to work with terrestrial mining companies to spin-in/spin-off technologies and capabilities, and space mining companies to expand our economy beyond Earth orbit. In the last two years, NASA has focused on developing and implementing a sustainable human space exploration program with the ultimate goal of exploring the surface of Mars with humans. The plan involves developing technology and capability building blocks critical for sustained exploration starting with the Space Launch System (SLS) and Orion crew spacecraft and utilizing the International Space Station as a springboard into the solar system. The evolvable plan develops and expands human exploration in phases starting with missions that are reliant on Earth, to

  7. Short-term plasticity of the human auditory cortex.

    PubMed

    Pantev, C; Wollbrink, A; Roberts, L E; Engelien, A; Lütkenhöner, B

    1999-09-18

    Magnetoencephalographic measurements (MEG) were used to examine the effect on the human auditory cortex of removing specific frequencies from the acoustic environment. Subjects listened for 3 h on three consecutive days to music "notched" by removal of a narrow frequency band centered on 1 kHz. Immediately after listening to the notched music, the neural representation for a 1-kHz test stimulus centered on the notch was found to be significantly diminished compared to the neural representation for a 0.5-kHz control stimulus centered one octave below the region of notching. The diminished neural representation for 1 kHz reversed to baseline between the successive listening sessions. These results suggest that rapid changes can occur in the tuning of neurons in the adult human auditory cortex following manipulation of the acoustic environment. A dynamic form of neural plasticity may underlie the phenomenon observed here. PMID:10526109

  8. Space Resource Utilization: Near-Term Missions and Long-Term Plans for Human Exploration

    NASA Technical Reports Server (NTRS)

    Sanders, Gerald B.

    2015-01-01

    A primary goal of all major space faring nations is to explore space: from the Earth with telescopes, with robotic probes and space telescopes, and with humans. For the US National Aeronautics and Space Administration (NASA), this pursuit is captured in three important strategic goals: 1. Ascertain the content, origin, and evolution of the solar system and the potential for life elsewhere, 2. Extend and sustain human activities across the solar system (especially the surface of Mars), and 3. Create innovative new space technologies for exploration, science, and economic future. While specific missions and destinations are still being discussed as to what comes first, it is imperative for NASA that it foster the development and implementation of new technologies and approaches that make space exploration affordable and sustainable. Critical to achieving affordable and sustainable human exploration beyond low Earth orbit (LEO) is the development of technologies and systems to identify, extract, and use resources in space instead of bringing everything from Earth. To reduce the development and implementation costs for space resource utilization, often called In Situ Resource Utilization (ISRU), it is imperative to work with terrestrial mining companies to spin-in/spin-off technologies and capabilities, and space mining companies to expand our economy beyond Earth orbit. In the last two years, NASA has focused on developing and implementing a sustainable human space exploration program with the ultimate goal of exploring the surface of Mars with humans. The plan involves developing technology and capability building blocks critical for sustained exploration starting with the Space Launch System (SLS) and Orion crew spacecraft and utilizing the International Space Station as a springboard into the solar system. The evolvable plan develops and expands human exploration in phases starting with missions that are reliant on Earth, to performing ever more challenging and

  9. Low dose CT perfusion using k-means clustering

    NASA Astrophysics Data System (ADS)

    Pisana, Francesco; Henzler, Thomas; Schönberg, Stefan; Klotz, Ernst; Schmidt, Bernhard; Kachelrieß, Marc

    2016-03-01

    We aim at improving low dose CT perfusion functional parameters maps and CT images quality, preserving quantitative information. In a dynamic CT perfusion dataset, each voxel is measured T times, where T is the number of acquired time points. In this sense, we can think about a voxel as a point in a T-dimensional space, where the coordinates of the voxels would be the values of its time attenuation curve (TAC). Starting from this idea, a k-means algorithm was designed to group voxels in K classes. A modified guided time-intensity profile similarity (gTIPS) filter was implemented and applied only for those voxels belonging to the same class. The approach was tested on a digital brain perfusion phantom as well as on clinical brain and body perfusion datasets, and compared to the original TIPS implementation. The TIPS filter showed the highest CNR improvement, but lowest spatial resolution. gTIPS proved to have the best combination of spatial resolution and CNR improvement for CT images, while k-gTIPS was superior to both gTIPS and TIPS in terms of perfusion maps image quality. We demonstrate k-means clustering analysis can be applied to denoise dynamic CT perfusion data and to improve functional maps. Beside the promising results, this approach has the major benefit of being independent from the perfusion model employed for functional parameters calculation. No similar approaches were found in literature.

  10. Human Endothelial Cells: Use of Heparin in Cloning and Long-Term Serial Cultivation

    NASA Astrophysics Data System (ADS)

    Thornton, Susan C.; Mueller, Stephen N.; Levine, Elliot M.

    1983-11-01

    Endothelial cells from human blood vessels were cultured in vitro, with doubling times of 17 to 21 hours for 42 to 79 population doublings. Cloned human endothelial cell strains were established for the first time and had similar proliferative capacities. This vigorous cell growth was achieved by addition of heparin to culture medium containing reduced concentrations of endothelial cell growth factor. The routine cloning and long-term culture of human endothelial cells will facilitate studying the human endothelium in vitro.

  11. Mouse retrovirus mediates porcine endogenous retrovirus transmission into human cells in long-term human-porcine chimeric mice

    PubMed Central

    Yang, Yong-Guang; Wood, James C.; Lan, Ping; Wilkinson, Robert A.; Sykes, Megan; Fishman, Jay A.; Patience, Clive

    2004-01-01

    Porcine endogenous retrovirus (PERV) is a potential pathogen in clinical xenotransplantation; transmission of PERV in vivo has been suggested in murine xenotransplantation models. We analyzed the transmission of PERV to human cells in vivo using a model in which immunodeficient NOD/SCID transgenic mice were transplanted with porcine and human lymphohematopoietic tissues. Our results demonstrate, we believe for the first time, that human and pig cells can coexist long-term (up to 25 weeks) without direct PERV infection of human cells. Despite the transplantation of porcine cells that did not produce human-tropic PERV, human cells from the chimeric mice were frequently found to contain PERV sequences. However, this transmission was due to the pseudotyping of PERV-C (a virus without human tropism) by xenotropic murine leukemia virus, rather than to de novo generation of human-tropic PERV. Thus, pseudotyping might account for the PERV transmission previously observed in mice. The absence of direct human cell infection following long-term in vivo coexistence with large numbers of porcine cells provides encouragement regarding the potential safety of using pigs that do not produce human-tropic PERV as source animals for transplantation to humans. PMID:15343388

  12. Meta-analysis of data from human ex vivo placental perfusion studies on genotoxic and immunotoxic agents within the integrated European project NewGeneris.

    PubMed

    Mose, T; Mathiesen, L; Karttunen, V; Nielsen, J K S; Sieppi, E; Kummu, M; Mørck, T A; Myöhänen, K; Partanen, H; Vähäkangas, K; Knudsen, L E; Myllynen, P

    2012-05-01

    In the E.U. integrated project NewGeneris, we studied placental transport of thirteen immunotoxic and genotoxic agents in three ex vivo placental perfusion laboratories. In the present publication, all placental perfusion data have been re-analyzed and normalized to make them directly comparable and rankable. Antipyrine transfer data differed significantly between the studies and laboratories, and therefore normalization of data was necessary. An antipyrine normalization factor was introduced making the variance significantly smaller within and between the studies using the same compound but performed in different laboratories. Non-normalized (regular) and normalized data showed a good correlation. The compounds were ranked according to their transplacental transfer rate using either antipyrine normalized AUC120 or transfer index (TI120(%)). Normalization generated a division of compounds in slow, medium and high transfer rate groups. The transfer rate differed slightly depending on the parameter used. However, compounds with passage similar to antipyrine which goes through the placenta by passive diffusion, and good recovery in media (no accumulation in the tissue or adherence to equipment) were highly ranked no matter which parameter was used. Antipyrine normalization resulted in the following ranking order of compounds according to AUC(120NORM) values: NDMA ≥ EtOH ≥ BPA ≥ IQ ≥AA ≥ GA ≥ PCB180 ≥ PhIP ≥ AFB1 > DON ≥ BP ≥ PCB52 ≥ TCDD. As the variance in all parameters within a study decreased after antipyrine normalization, we conclude that this normalization approach at least partially corrects the bias caused by the small methodological differences between studies. PMID:22374511

  13. Lung Ventilation/Perfusion Scan

    MedlinePlus

    ... from the NHLBI on Twitter. What Is a Lung Ventilation/Perfusion Scan? A lung ventilation/perfusion scan, or VQ scan, is a ... that measures air and blood flow in your lungs. A VQ scan most often is used to ...

  14. Fostering Humane Care of Dying Persons in Long-Term Care. Guidebook for Staff Development Instructors.

    ERIC Educational Resources Information Center

    Wilson, Sarah A.; Daley, Barbara

    This guide is intended for staff development instructors responsible for inservice education on the topic of fostering humane care for dying persons in long-term care. The introduction discusses the guide's development based on input from administrators, staff, and families of residents in long-term care facilities and focus group interviews in…

  15. Long-term trends in human demography and economy across sites

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This chapter shows long-term data and trends in human demography and economy for each site. It contains a brief introduction to the topic, and methods of measurements, selection of variables, and their data source. It consists primarily of a large number of figures showing long-term data for differ...

  16. Increased Resting-State Perfusion after Repeated Encoding Is Related to Later Retrieval of Declarative Associative Memories

    PubMed Central

    Groen, Georg; Sokolov, Alexander N.; Jonas, Christina; Roebling, Robert; Spitzer, Manfred

    2011-01-01

    Electrophysiological studies in animals have shown coordinated reactivation of neuronal ensembles during a restricted time period of behavioral inactivity that immediately followed active encoding. In the present study we directly investigated off-line processing of associative memory formation in the human brain. Subjects' regional cerebral blood flow (rCBF) as a surrogate marker of neural activity during rest was measured by MR-based perfusion imaging in a sample of 14 healthy male subjects prior to (Pre2) and after (Post) extensive learning of 24 face-name associations within a selective reminding task (SR). Results demonstrated significant Post-Pre2 rCBF increases in hippocampal and temporal lobe regions, while in a control comparison of two perfusion scans with no learning task in-between (Pre2-Pre1) no differences in rCBF emerged. Post perfusion scanning was followed by a surprise cued associative recall task from which two types of correctly retrieved names were obtained: older names already correctly retrieved at least once during one of the SR blocks, and recent names acquired during the last SR block immediately prior to the Post scan. In the anterior hippocampus individual perfusion increases were correlated with both correct retrievals of older and recent names. By contrast, older but not recently learned names showed a significant correlation with perfusion increases in the left lateral temporal cortex known to be associated with long-term memory. Recent, but not older names were correlated with dopaminergic midbrain structures reported to contribute to the persistence of memory traces for novel information. Although the direct investigation of off-line memory processing did not permit concomitant experimental control, neither intentional rehearsal, nor substantial variations in subjects' states of alertness appear to contribute to present results. We suggest that the observed rCBF increases might reflect processes that possibly contribute to the long-term

  17. Ex vivo lung perfusion.

    PubMed

    Machuca, Tiago N; Cypel, Marcelo

    2014-08-01

    Lung transplantation (LTx) is an established treatment option for eligible patients with end-stage lung disease. Nevertheless, the imbalance between suitable donor lungs available and the increasing number of patients considered for LTx reflects in considerable waitlist mortality. Among potential alternatives to address this issue, ex vivo lung perfusion (EVLP) has emerged as a modern preservation technique that allows for more accurate lung assessment and also improvement of lung function. Its application in high-risk donor lungs has been successful and resulted in safe expansion of the donor pool. This article will: (I) review the technical details of EVLP; (II) the rationale behind the method; (III) report the worldwide clinical experience with the EVLP, including the Toronto technique and others; (IV) finally, discuss the growing literature on EVLP application for donation after cardiac death (DCD) lungs. PMID:25132972

  18. Ex vivo lung perfusion

    PubMed Central

    Machuca, Tiago N.

    2014-01-01

    Lung transplantation (LTx) is an established treatment option for eligible patients with end-stage lung disease. Nevertheless, the imbalance between suitable donor lungs available and the increasing number of patients considered for LTx reflects in considerable waitlist mortality. Among potential alternatives to address this issue, ex vivo lung perfusion (EVLP) has emerged as a modern preservation technique that allows for more accurate lung assessment and also improvement of lung function. Its application in high-risk donor lungs has been successful and resulted in safe expansion of the donor pool. This article will: (I) review the technical details of EVLP; (II) the rationale behind the method; (III) report the worldwide clinical experience with the EVLP, including the Toronto technique and others; (IV) finally, discuss the growing literature on EVLP application for donation after cardiac death (DCD) lungs. PMID:25132972

  19. Optimization of the method for assessment of brain perfusion in humans using contrast-enhanced reflectometry: multidistance time-resolved measurements

    NASA Astrophysics Data System (ADS)

    Milej, Daniel; Janusek, Dariusz; Gerega, Anna; Wojtkiewicz, Stanislaw; Sawosz, Piotr; Treszczanowicz, Joanna; Weigl, Wojciech; Liebert, Adam

    2015-10-01

    The aim of the study was to determine optimal measurement conditions for assessment of brain perfusion with the use of optical contrast agent and time-resolved diffuse reflectometry in the near-infrared wavelength range. The source-detector separation at which the distribution of time of flights (DTOF) of photons provided useful information on the inflow of the contrast agent to the intracerebral brain tissue compartments was determined. Series of Monte Carlo simulations was performed in which the inflow and washout of the dye in extra- and intracerebral tissue compartments was modeled and the DTOFs were obtained at different source-detector separations. Furthermore, tests on diffuse phantoms were carried out using a time-resolved setup allowing the measurement of DTOFs at 16 source-detector separations. Finally, the setup was applied in experiments carried out on the heads of adult volunteers during intravenous injection of indocyanine green. Analysis of statistical moments of the measured DTOFs showed that the source-detector separation of 6 cm is recommended for monitoring of inflow of optical contrast to the intracerebral brain tissue compartments with the use of continuous wave reflectometry, whereas the separation of 4 cm is enough when the higher-order moments of DTOFs are available.

  20. Characterizing potential heart agents with an isolated perfused heart system

    SciTech Connect

    Pendleton, D.B.; Sands, H.; Gallagher, B.M.; Camin, L.L.

    1984-01-01

    The authors have used an isolated perfused heart system for characterizing potential myocardial perfusion radiopharamaceuticals. Rabbit or guinea pig (GP) hearts are removed and perfused through the aorta with a blood-free buffer. Heart rate and ventricular pressure are monitored as indices of viability. Tc-99m-MAA is 96-100% retained in these hearts, and Tc-99m human serum albumin shows less than 5% extraction. Tl-201 is 30-40% extracted. It is known that in-vivo, Tc-99m(dmpe)/sub 2/Cl/sub 2//sup +/ is taken up by rabbit heart but not by GP or human heart. Analogous results are obtained with the isolated perfused heart model, where the complex is extracted well by the isolated rabbit heart (24%) but not by the GP heart (<5%). Values are unchanged if human, rabbit or GP blood is mixed and co-injected with the complex. Tc-99m)dmpe)/sub 3//sup +/ is also taken up by rabbit but not by GP hearts in-vivo. However, isolated perfused hearts of both species extract this complex well (45-52%). Heart uptake is diminished to <7% if the complex is pre-equilibrated with human blood. GP blood produces a moderate inhibition (in GP hearts only) and rabbit blood has no effect. This suggests that a human or GP blood factor may have a significant effect on heart uptake of this complex. Tc-99m(CN-t-butyl)/sub 6//sup +/ is taken up well by both rabbit and GP hearts in-vivo, and is extracted 100% by both isolated perfused hearts. Heart retention remains high (73-75%) in the presence of human blood.

  1. Effects of short-term training on sensory and motor function in severed nerves of long-term human amputees.

    PubMed

    Dhillon, G S; Krüger, T B; Sandhu, J S; Horch, K W

    2005-05-01

    Much has been studied and written about plastic changes in the CNS of humans triggered by events such as limb amputation. However, little is known about the extent to which the original pathways retain residual function after peripheral amputation. Our earlier, acute study on long-term amputees indicated that central pathways associated with amputated peripheral nerves retain at least some sensory and motor function. The purpose of the present study was to determine if these functional connections would be strengthened or improved with experience and training over several days time. To do this, electrodes were implanted within fascicles of severed nerves of long-term human amputees to evaluate the changes in electrically evoked sensations and volitional motor neuron activity associated with attempted phantom limb movements. Nerve stimulation consistently resulted in discrete, unitary, graded sensations of touch/pressure and joint-position sense. There was no significant change in the values of stimulation parameters required to produce these sensations over time. Similarly, while the amputees were able to improve volitional control of motor neuron activity, the rate and pattern of change was similar to that seen with practice in normal individuals on motor tasks. We conclude that the central plasticity seen after amputation is most likely primarily due to unmasking, rather than replacement, of existing synaptic connections. These results also have implications for neural control of prosthetic limbs. PMID:15846000

  2. Psychophysiological effects of human-animal interaction: theoretical issues and long-term interaction effects.

    PubMed

    Virués-Ortega, Javier; Buela-Casal, Gualberto

    2006-01-01

    This paper reviews literature published on the psychophysiological effects of long-term human-animal interaction (i.e., pet ownership, pet adoption). A literature search was conducted using PsycInfo and Medline databases. Although the available evidence is far from being consistent, it can be concluded that, in some cases, long-term relationships with animals may moderate baseline physiological variables, particularly blood pressure. Results proved more coherent in studies where animals were adopted by owners as part of the procedure. This paper examines existing hypotheses seeking to account for these effects and the supporting evidence. Two major hypotheses have been suggested to explain the psychophysiological effects of long-term interaction, namely (1) stress-buffering effects of noncritical social support provided by pets; and (2) classical conditioning of relaxation. These mechanisms may partially account for the long-term health outcomes observed in a number of human-animal interaction studies. PMID:16462556

  3. Short-term fasting alters cytochrome P450-mediated drug metabolism in humans.

    PubMed

    Lammers, Laureen A; Achterbergh, Roos; de Vries, Emmely M; van Nierop, F Samuel; Klümpen, Heinz-Josef; Soeters, Maarten R; Boelen, Anita; Romijn, Johannes A; Mathôt, Ron A A

    2015-06-01

    Experimental studies indicate that short-term fasting alters drug metabolism. However, the effects of short-term fasting on drug metabolism in humans need further investigation. Therefore, the aim of this study was to evaluate the effects of short-term fasting (36 h) on P450-mediated drug metabolism. In a randomized crossover study design, nine healthy subjects ingested a cocktail consisting of five P450-specific probe drugs [caffeine (CYP1A2), S-warfarin (CYP2C9), omeprazole (CYP2C19), metoprolol (CYP2D6), and midazolam (CYP3A4)] on two occasions (control study after an overnight fast and after 36 h of fasting). Blood samples were drawn for pharmacokinetic analysis using nonlinear mixed effects modeling. In addition, we studied in Wistar rats the effects of short-term fasting on hepatic mRNA expression of P450 isoforms corresponding with the five studied P450 enzymes in humans. In the healthy subjects, short-term fasting increased oral caffeine clearance by 20% (P = 0.03) and decreased oral S-warfarin clearance by 25% (P < 0.001). In rats, short-term fasting increased mRNA expression of the orthologs of human CYP1A2, CYP2C19, CYP2D6, and CYP3A4 (P < 0.05), and decreased the mRNA expression of the ortholog of CYP2C9 (P < 0.001) compared with the postabsorptive state. These results demonstrate that short-term fasting alters cytochrome P450-mediated drug metabolism in a nonuniform pattern. Therefore, short-term fasting is another factor affecting cytochrome P450-mediated drug metabolism in humans. PMID:25795462

  4. Hydrostatic determinants of cerebral perfusion

    SciTech Connect

    Wagner, E.M.; Traystman, R.J.

    1986-05-01

    We examined the cerebral blood flow response to alterations in perfusion pressure mediated through decreases in mean arterial pressure, increases in cerebrospinal fluid (CSF) pressure, and increases in jugular venous (JV) pressure in 42 pentobarbital anesthetized dogs. Each of these three pressures was independently controlled. Cerebral perfusion pressure was defined as mean arterial pressure minus JV or CSF pressure, depending on which was greater. Mean hemispheric blood flow was measured with the radiolabeled microsphere technique. Despite 30-mm Hg reductions in mean arterial pressure or increases in CSF or JV pressure, CBF did not change as long as the perfusion pressure remained greater than approximately 60 mm Hg. However, whenever perfusion pressure was reduced to an average of 48 mm Hg, cerebral blood flow decreased 27% to 33%. These results demonstrate the capacity of the cerebral vascular bed to respond similarly to changes in the perfusion pressure gradient obtained by decreasing mean arterial pressure, increasing JV pressure or increasing CSF pressure, and thereby support the above definition of cerebral perfusion pressure.

  5. Effect of leptin on progesterone, human chorionic gonadotropin, and interleukin-6 secretion by human term trophoblast cells in culture.

    PubMed

    Cameo, Paula; Bischof, Paul; Calvo, Juan Carlos

    2003-02-01

    Leptin, the 16-kDa protein product of the obese gene, was originally seen as an adipocyte-derived signaling molecule. Recently, it has been suggested to be involved in some functions during pregnancy, particularly in the placenta. In the present study, we investigated the role of leptin in the secretion of hCG, progesterone, and interleukin-6 (IL-6) by human term trophoblast cells in culture. Placentae were obtained from cesarean sections following uncomplicated pregnancies and used immediately after delivery. Leptin, hCG, progesterone, and IL-6 were measured by ELISA, RIA, and immunoradiometric assay in the cultured media of trophoblast cells cultured for 48 and 96 h. Leptin mRNA expression in these cultures was determined by reverse transcription-polymerase chain reaction. Recombinant human leptin added to primary cultures of human term placental trophoblast cells showed a stimulatory effect on hCG and IL-6 secretion and an inhibitory effect on progesterone secretion. Primary cultures of term trophoblast cells expressed leptin mRNA. All these findings suggest a role for leptin in human placental endocrine function. PMID:12533410

  6. CAD of myocardial perfusion

    NASA Astrophysics Data System (ADS)

    Storm, Corstiaan J.; Slump, Cornelis H.

    2007-03-01

    Our purpose is in the automated evaluation of the physiological relevance of lesions in coronary angiograms. We aim to extract as much as possible quantitative information about the physiological condition of the heart from standard angiographic image sequences. Coronary angiography is still the gold standard for evaluating and diagnosing coronary abnormalities as it is able to locate precisely the coronary artery lesions. The dimensions of the stenosis can be assessed nowadays successfully with image processing based Quantitative Coronary Angiography (QCA) techniques. Our purpose is to assess the clinical relevance of the pertinent stenosis. We therefore analyze the myocardial perfusion as revealed in standard angiographic image sequences. In a Region-of-Interest (ROI) on the angiogram (without an overlaying major blood vessel) the contrast is measured as a function of time (the so-called time-density curve). The required hyperemic state of exercise is induced artificially by the injection of a vasodilator drug e.g. papaverine. In order to minimize motion artifacts we select based on the recorded ECG signal end-diastolic images in both a basal and a hyperemic run in the same projection to position the ROI. We present the development of the algorithms together with results of a small study of 20 patients which have been catheterized following the standard protocol.

  7. Tissue-engineering bioreactors: a new combined cell-seeding and perfusion system for vascular tissue engineering.

    PubMed

    Sodian, Ralf; Lemke, Thees; Fritsche, Clemens; Hoerstrup, Simon P; Fu, Ping; Potapov, Evgenij V; Hausmann, Harald; Hetzer, Roland

    2002-10-01

    One approach to the tissue engineering of vascular structures is to develop in vitro conditions in order ultimately to fabricate functional vascular tissues before final implantation. In our experiment, we aimed to develop a new combined cell seeding and perfusion system that provides sterile conditions during cell seeding and biomechanical stimuli in order to fabricate autologous human vascular tissue in vitro. The cell seeding and perfusion system is made of Plexiglas and is completely transparent (Berlin Heart, Berlin, Germany; University Hospital Benjamin Franklin, Berlin, Germany). The whole system consists of a cell seeding chamber that can be incorporated into the perfusion system and an air-driven respirator pump connected to the bioreactor. The cell culture medium continuously circulates through a closed-loop system. We thus developed a cell seeding device for static and dynamic seeding of vascular cells onto a polymeric vascular scaffold and a closed-loop perfused bioreactor for long-term vascular conditioning. The cell seeding chamber can be easily connected to the bioreactor, which combines continuous, pulsatile perfusion and mechanical stimulation to the tissue-engineered conduit. Adjusting the stroke volume, the stroke rate, and the inspiration/expiration time of the ventilator allows various pulsatile flows and different levels of pressure. The whole system is a highly isolated cell culture setting, which provides a high level of sterility and a gas supply and fits into a standard humidified incubator. The device can be sterilized by ethylene oxide and assembled with a standard screwdriver. Our newly developed combination of a cell seeding and conditioning device provides sterile conditions and biodynamic stimuli for controlled tissue development and in vitro conditioning of an autologous tissue-engineered vessel. PMID:12459065

  8. Endogenous Human Milk Peptide Release Is Greater after Preterm Birth than Term Birth123

    PubMed Central

    Dallas, David C; Smink, Christina J; Robinson, Randall C; Tian, Tian; Guerrero, Andres; Parker, Evan A; Smilowitz, Jennifer T; Hettinga, Kasper A; Underwood, Mark A; Lebrilla, Carlito B; German, J Bruce; Barile, Daniela

    2015-01-01

    Background: Hundreds of naturally occurring milk peptides are present in term human milk. Preterm milk is produced before complete maturation of the mammary gland, which could change milk synthesis and secretion processes within the mammary gland, leading to differences in protein expression and enzymatic activity, thereby resulting in an altered peptide profile. Objective: This study examined differences in peptides present between milk from women delivering at term and women delivering prematurely. Methods: Nano-LC tandem mass spectrometry was employed to identify naturally occurring peptides and compare their abundances between term and preterm human milk samples at multiple time points over lactation. Term milk samples were collected from 8 mothers and preterm milk was collected from 14 mothers. The 28 preterm and 32 term human milk samples were divided into 4 groups based on day of collection (<14, 14–28, 29–41, and 42–58 d). Results: Preterm milk peptide counts, ion abundance, and concentration were significantly higher in preterm milk than term milk. Bioinformatic analysis of the cleavage sites for peptides identified suggested that plasmin was more active in preterm milk than term milk and that cytosol aminopeptidase and carboxypeptidase B2 likely contribute to extensive milk protein breakdown. Many identified milk peptides in both term and preterm milk overlapped with known functional peptides, including antihypertensive, antimicrobial, and immunomodulatory peptides. Conclusion: The high protein degradation by endogenous proteases in preterm milk might attenuate problems because of the preterm infant’s immature digestive system. This trial was registered at clinicaltrials.gov as NCT01817127. PMID:25540406

  9. Short-Term Plasticity of the Visuomotor Map during Grasping Movements in Humans

    ERIC Educational Resources Information Center

    Safstrom, Daniel; Edin, Benoni B.

    2005-01-01

    During visually guided grasping movements, visual information is transformed into motor commands. This transformation is known as the "visuomotor map." To investigate limitations in the short-term plasticity of the visuomotor map in normal humans, we studied the maximum grip aperture (MGA) during the reaching phase while subjects grasped objects…

  10. Reframing Photographic Research Methods in Human Geography: A Long-Term Reflection

    ERIC Educational Resources Information Center

    Hall, Tim

    2015-01-01

    This paper offers a long-term reflection on the introduction of a photographic research project into a third-year undergraduate Human Geography module. The findings indicate that, whilst the students valued the project, it did impact on their overall performance, their evaluation of the module and the ways in which they spoke about it. The paper…

  11. Civil Conflict and Human Capital Accumulation: The Long-Term Effects of Political Violence in Peru

    ERIC Educational Resources Information Center

    Leon, Gianmarco

    2012-01-01

    This paper provides empirical evidence of the persistent effect of exposure to political violence on human capital accumulation. I exploit the variation in conflict location and birth cohorts to identify the long- and short-term effects of the civil war on educational attainment. Conditional on being exposed to violence, the average person…

  12. Citizenship, Nationalism, Human Rights and Democracy: A Tangling of Terms in the Kuwaiti Curriculum

    ERIC Educational Resources Information Center

    Al-Nakib, Rania

    2011-01-01

    Background: Citizenship, nationalism, human rights and democracy are four terms and concepts that are inextricably linked. In Kuwait, the status of citizen is based on nationality, gender and age, with women, children, naturalised citizens, expatriates and "bidoon" (stateless people) denied many freedoms, rights and services. Citizenship is…

  13. MR Perfusion Imaging in Acute Ischemic Stroke

    PubMed Central

    Copen, William A.; Schaefer, Pamela W.; Wu, Ona

    2011-01-01

    MR perfusion imaging offers the potential for measuring brain perfusion in acute stroke patients, at a time when treatment decisions based upon these measurements may affect outcomes dramatically. Rapid advancements in both acute stroke therapy and perfusion imaging techniques have resulted in continuing redefinition of the role that perfusion imaging should play in patient management. This review first discusses the basic pathophysiology of acute stroke, with specific attention to alterations in the various perfusion-related parameters that can be studied by MR perfusion imaging. Although these parameters are sometimes treated as somewhat interchangeable, they reveal greatly different information about brain perfusion. Therefore, subsequent discussion of the utility of different kinds of perfusion images focuses on the differences between them, as well as important artifacts that can complicate their interpretation. Finally, research on the continually evolving role of MR perfusion imaging in acute stroke care is summarized. PMID:21640299

  14. PHENOstruct: Prediction of human phenotype ontology terms using heterogeneous data sources

    PubMed Central

    Kahanda, Indika; Funk, Christopher; Verspoor, Karin; Ben-Hur, Asa

    2015-01-01

    The human phenotype ontology (HPO) was recently developed as a standardized vocabulary for describing the phenotype abnormalities associated with human diseases. At present, only a small fraction of human protein coding genes have HPO annotations. But, researchers believe that a large portion of currently unannotated genes are related to disease phenotypes. Therefore, it is important to predict gene-HPO term associations using accurate computational methods. In this work we demonstrate the performance advantage of the structured SVM approach which was shown to be highly effective for Gene Ontology term prediction in comparison to several baseline methods. Furthermore, we highlight a collection of informative data sources suitable for the problem of predicting gene-HPO associations, including large scale literature mining data. PMID:26834980

  15. Vascular Tissue Engineering: Building Perfusable Vasculature for Implantation

    PubMed Central

    Gui, Liqiong; Niklason, Laura E.

    2014-01-01

    Tissue and organ replacement is required when there are no alternative therapies available. Although vascular tissue engineering was originally developed to meet the clinical demands of small-diameter vascular conduits as bypass grafts, it has evolved into a highly advanced field where perfusable vasculatures are generated for implantation. Herein, we review several cutting-edge techniques that have led to implantable human blood vessels in clinical trials, the novel approaches that build complex perfusable microvascular networks in functional tissues, the use of stem cells to generate endothelial cells for vascularization, as well as the challenges in bringing vascular tissue engineering technologies into the clinics. PMID:24533306

  16. Short-term antibiotic treatment has differing long-term impacts on the human throat and gut microbiome

    SciTech Connect

    Jakobsson, H.; Jernberg, C.; Andersson, A.F.; Sjolund-Karlsson, M.; Jansson, J.K.; Engstrand, L.

    2010-01-15

    Antibiotic administration is the standard treatment for the bacterium Helicobacter pylori, the main causative agent of peptic ulcer disease and gastric cancer. However, the long-term consequences of this treatment on the human indigenous microbiota are relatively unexplored. Here we studied short- and long-term effects of clarithromycin and metronidazole treatment, a commonly used therapy regimen against H. pylori, on the indigenous microbiota in the throat and in the lower intestine. The bacterial compositions in samples collected over a four year period were monitored by analyzing the 16S rRNA gene using 454-based pyrosequencing and terminal-restriction fragment length polymorphism (T-RFLP). While the microbial communities of untreated control subjects were relatively stable over time, dramatic shifts were observed one week after antibiotic treatment with reduced bacterial diversity in all treated subjects in both locations. While the microbiota of the different subjects responded uniquely to the antibiotic treatment some general trends could be observed; such as a dramatic decline in Actinobacteria in both throat and feces immediately after treatment. Although the diversity of the microbiota subsequently recovered to resemble the pre treatment states, the microbiota remained perturbed in some cases for up to four years post treatment. In addition, four years after treatment high levels of the macrolide resistance gene erm(B) were found, indicating that antibiotic resistance, once selected for, can persist for longer periods of time than previously recognized. This highlights the importance of a restrictive antibiotic usage in order to prevent subsequent treatment failure and potential spread of antibiotic resistance.

  17. Extraction of DNA from human embryos after long-term preservation in formalin and Bouin's solutions.

    PubMed

    Nagai, Momoko; Minegishi, Katsura; Komada, Munekazu; Tsuchiya, Maiko; Kameda, Tomomi; Yamada, Shigehito

    2016-05-01

    The "Kyoto Collection of Human Embryos" at Kyoto University was begun in 1961. Although morphological analyses of samples in the Kyoto Collection have been performed, these embryos have been considered difficult to genetically analyze because they have been preserved in formalin or Bouin's solution for 20-50 years. Owing to the recent advances in molecular biology, it has become possible to extract DNA from long-term fixed tissues. The purpose of this study was to extract DNA from wet preparations of human embryo samples after long-term preservation in fixing solution. We optimized the DNA extraction protocol to be suitable for tissues that have been damaged by long-term fixation, including DNA-protein crosslinking damage. Diluting Li2 CO3 with 70% ethanol effectively removed picric acid from samples fixed in Bouin's solution. Additionally, 20.0 mg/mL proteinase was valuable to lyse the long-term fixed samples. The extracted DNA was checked with PCR amplification using several sets of primers and sequence analysis. The PCR products included at least 295- and 838-bp amplicons. These results show that the extracted DNA is applicable for genetic analyses, and indicate that old embryos in the Kyoto Collection should be made available for future studies. The protocol described in this study can successfully extract DNA from old specimens and, with improvements, should be applicable in research aiming to understand the molecular mechanisms of human congenital anomalies. PMID:26662860

  18. Laser-induced macular holes demonstrate impaired choroidal perfusion

    NASA Astrophysics Data System (ADS)

    Brown, Jeremiah, Jr.; Allen, Ronald D.; Zwick, Harry; Schuschereba, Steven T.; Lund, David J.; Stuck, Bruce E.

    2003-06-01

    Choroidal perfusion was evaluated following the creation of a laser induced macular hole in a nonhuman primate model. Two Rhesus monkeys underwent macular exposures delivered by a Q-switched Nd:YAG laser. The lesions were evaluated with fluorescein angiography and indocyanine green (ICG) angiography . Each lesion produced vitreous hemorrhage and progressed to a full thickness macular hole. ICG angiography revealed no perfusion of the choriocapillaris beneath the lesion centers. Histopathologic evaluation showed replacement of the choriocapillaris with fibroblasts and connective tissue. Nd:YAG, laser-induced macular holes result in long term impairment of choroidal perfusion at the base of the hole due to choroidal scarring and obliteration of the choriocapillaris.

  19. Phenotypic and Functional Characterization of Long-Term Cryopreserved Human Adipose-derived Stem Cells

    PubMed Central

    Yong, Kar Wey; Pingguan-Murphy, Belinda; Xu, Feng; Abas, Wan Abu Bakar Wan; Choi, Jane Ru; Omar, Siti Zawiah; Azmi, Mat Adenan Noor; Chua, Kien Hui; Safwani, Wan Kamarul Zaman Wan

    2015-01-01

    Cryopreservation represents an effective technique to maintain the functional properties of human adipose-derived stem cells (ASCs) and allows pooling of cells via long-term storage for clinical applications, e.g., cell-based therapies. It is crucial to reduce freezing injury during the cryopreservation process by loading the ASCs with the optimum concentration of suitable cryoprotective agents (CPAs). In this study, human ASCs were preserved for 3 months in different combinations of CPAs, including 1) 0.25 M trehalose; 2) 5% dimethylsulfoxide (DMSO); 3) 10% DMSO; 4) 5% DMSO + 20% fetal bovine serum (FBS); 5) 10% DMSO + 20% FBS; 6) 10% DMSO + 90% FBS. Interestingly, even with a reduction of DMSO to 5% and without FBS, cryopreserved ASCs maintained high cell viability comparable with standard cryomedium (10% DMSO + 90% FBS), with normal cell phenotype and proliferation rate. Cryopreserved ASCs also maintained their differentiation capability (e.g., to adipocytes, osteocytes and chondrocytes) and showed an enhanced expression level of stemness markers (e.g., NANOG, OCT-4, SOX-2 and REX-1). Our findings suggest that 5% DMSO without FBS may be an ideal CPA for an efficient long-term cryopreservation of human ASCs. These results aid in establishing standardized xeno-free long-term cryopreservation of human ASCs for clinical applications. PMID:25872464

  20. Modelling of temperature and perfusion during scalp cooling

    NASA Astrophysics Data System (ADS)

    Janssen, F. E. M.; Van Leeuwen, G. M. J.; Van Steenhoven, A. A.

    2005-09-01

    Hair loss is a feared side effect of chemotherapy treatment. It may be prevented by cooling the scalp during administration of cytostatics. The supposed mechanism is that by cooling the scalp, both temperature and perfusion are diminished, affecting drug supply and drug uptake in the hair follicle. However, the effect of scalp cooling varies strongly. To gain more insight into the effect of cooling, a computer model has been developed that describes heat transfer in the human head during scalp cooling. Of main interest in this study are the mutual influences of scalp temperature and perfusion during cooling. Results of the standard head model show that the temperature of the scalp skin is reduced from 34.4 °C to 18.3 °C, reducing tissue blood flow to 25%. Based upon variations in both thermal properties and head anatomies found in the literature, a parameter study was performed. The results of this parameter study show that the most important parameters affecting both temperature and perfusion are the perfusion coefficient Q10 and the thermal resistances of both the fat and the hair layer. The variations in the parameter study led to skin temperature ranging from 10.1 °C to 21.8 °C, which in turn reduced relative perfusion to 13% and 33%, respectively.

  1. Role of Extracranial Carotid Duplex and Computed Tomography Perfusion Scanning in Evaluating Perfusion Status of Pericarotid Stenting

    PubMed Central

    Lin, Chih-Ming; Chang, Yu-Jun; Liu, Chi-Kuang; Yu, Cheng-Sheng

    2016-01-01

    Carotid stenting is an effective treatment of choice in terms of treating ischemic stroke patients with concomitant carotid stenosis. Though computed tomography perfusion scan has been recognized as a standard tool to monitor/follow up this group of patients, not everyone could endure due to underlying medical illness. In contrast, carotid duplex is a noninvasive assessment tool and could track patient clinical condition in real time. In this study we found that “resistance index” of the carotid ultrasound could detect flow changes before and after the stenting procedure, thus having great capacity to replace the role of computed tomography perfusion exam. PMID:27051669

  2. Effects of Long Term Antibiotic Therapy on Human Oral and Fecal Viromes

    PubMed Central

    Abeles, Shira R.; Ly, Melissa; Santiago-Rodriguez, Tasha M.; Pride, David T.

    2015-01-01

    Viruses are integral members of the human microbiome. Many of the viruses comprising the human virome have been identified as bacteriophage, and little is known about how they respond to perturbations within the human ecosystem. The intimate association of phage with their cellular hosts suggests their communities may change in response to shifts in bacterial community membership. Alterations to human bacterial biota can result in human disease including a reduction in the host's resilience to pathogens. Here we report the ecology of oral and fecal viral communities and their responses to long-term antibiotic therapy in a cohort of human subjects. We found significant differences between the viral communities of each body site with a more heterogeneous fecal virus community compared with viruses in saliva. We measured the relative diversity of viruses, and found that the oral viromes were significantly more diverse than fecal viromes. There were characteristic changes in the membership of oral and fecal bacterial communities in response to antibiotics, but changes in fecal viral communities were less distinguishing. In the oral cavity, an abundance of papillomaviruses found in subjects on antibiotics suggests an association between antibiotics and papillomavirus production. Despite the abundance of papillomaviruses identified, in neither the oral nor the fecal viromes did antibiotic therapy have any significant impact upon overall viral diversity. There was, however, an apparent expansion of the reservoir of genes putatively involved in resistance to numerous classes of antibiotics in fecal viromes that was not paralleled in oral viromes. The emergence of antibiotic resistance in fecal viromes in response to long-term antibiotic therapy in humans suggests that viruses play an important role in the resilience of human microbial communities to antibiotic disturbances. PMID:26309137

  3. Peptidome analysis of human skim milk in term and preterm milk

    SciTech Connect

    Wan, Jun; Cui, Xian-wei; Zhang, Jun; Fu, Zi-yi; Guo, Xi-rong; Sun, Li-Zhou; Ji, Chen-bo

    2013-08-16

    Highlights: •A method was developed for preparation of peptide extracts from human milk. •Analysis of the extracts by LC–MS/MS resulted in the detection of 1000–3000 peptide-like features. •419 Peptides were identified by LC–MS/MS from 34 proteins. •Isotope dimethyl labeling analysis revealed 41 peptides differentially expressed. -- Abstract: The abundant proteins in human milk have been well characterized and are known to provide nutritional, protective, and developmental advantages to both term and preterm infants. Due to the difficulties associated with detection technology of the peptides, the expression of the peptides present in human milk is not known widely. In recent years, peptidome analysis has received increasing attention. In this report, the analysis of endogenous peptides in human milk was done by mass spectrometry. A method was also developed by our researchers, which can be used in the extraction of peptide from human milk. Analysis of the extracts by LC–MS/MS resulted in the detection of 1000–3000 Da peptide-like features. Out of these, 419 peptides were identified by MS/MS. The identified peptides were found to originate from 34 proteins, of which several have been reported. Analysis of the peptides’ cleavage sites showed that the peptides are cleaved with regulations. This may reflect the protease activity and distribution in human body, and also represent the biological state of the tissue and provide a fresh source for biomarker discovery. Isotope dimethyl labeling analysis was also used to test the effects of premature delivery on milk protein composition in this study. Differences in peptides expression between breast milk in term milk (38–41 weeks gestation) and preterm milk (28–32 weeks gestation) were investigated in this study. 41 Peptides in these two groups were found expressed differently. 23 Peptides were present at higher levels in preterm milk, and 18 were present at higher levels in term milk.

  4. Evaluating acellular versus cellular perfusate composition during prolonged ex vivo lung perfusion after initial cold ischaemia for 24 hours.

    PubMed

    Becker, Simon; Steinmeyer, Jasmin; Avsar, Murat; Höffler, Klaus; Salman, Jawad; Haverich, Axel; Warnecke, Gregor; Ochs, Matthias; Schnapper, Anke

    2016-01-01

    Normothermic ex vivo lung perfusion (EVLP) has developed as a powerful technique to evaluate particularly marginal donor lungs prior to transplantation. In this study, acellular and cellular perfusate compositions were compared in an identical experimental setting as no consensus has been reached on a preferred technique yet. Porcine lungs underwent EVLP for 12 h on the basis of an acellular or a cellular perfusate composition after 24 h of cold ischaemia as defined organ stress. During perfusion, haemodynamic and respiratory parameters were monitored. After EVLP, the lung condition was assessed by light and transmission electron microscopy. Aerodynamic parameters did not show significant differences between groups and remained within the in vivo range during EVLP. Mean oxygenation indices were 491 ± 39 in the acellular group and 513 ± 53 in the cellular group. Groups only differed significantly in terms of higher pulmonary artery pressure and vascular resistance in the cellular group. Lung histology and ultrastructure were largely well preserved after prolonged EVLP and showed only minor structural alterations which were similarly present in both groups. Prolonged acellular and cellular EVLP for 12 h are both feasible with lungs prechallenged by ischaemic organ stress. Physiological and ultrastructural analysis showed no superiority of either acellular or cellular perfusate composition. PMID:26264867

  5. Progesterone and human placental lactogen inhibit leptin secretion on cultured trophoblast cells from human placentas at term.

    PubMed

    Coya, Raquel; Martul, Pedro; Algorta, Jaime; Aniel-Quiroga, Ma Angeles; Busturia, Ma Angeles; Señarís, Rosa

    2005-07-01

    The placenta is an important source of leptin production that contributes to the state of hyperleptinemia observed in pregnant women. Moreover, the synthesis of leptin and its receptors by syncytiotrophoblast cells suggests a potential paracrine or autocrine action of leptin in the placenta. In the present study we examined the effect of gestational hormones, human chorionic gonadotropin (hCG), human placental lactogen (hPL), progesterone and estradiol, on in vitro leptin release by human term trophoblast cells in culture. Placentas at term were obtained immediately after delivery from mothers with uncomplicated pregnancies. Leptin levels were measured by enzyme-linked immunosorbent assay in culture media of trophoblasts maintained in monolayer culture for 24, 48 and 72 h with different hormonal treatments or placebo. Treatment with hPL and progesterone led to a time- and dose-dependent decrease in leptin release that was statistically significant after 24 h, with a maximal effect after 72 h of incubation. In contrast, incubation with estradiol and hCG did not have exhibit any effect on leptin secretion at any of the doses and times assayed in this work. The results obtained in this study support that leptin can be considered a gestational hormone implied in the endocrine function of the placenta and that its secretion is at least partially regulated by steroid and peptidic reproductive hormones in trophoblast cells in vitro. PMID:16048798

  6. Human Land-Use Practices Lead to Global Long-Term Increases in Photosynthetic Capacity

    NASA Technical Reports Server (NTRS)

    Mueller, Thomas; Tucker, Compton J.; Dressler, Gunnar; Pinzon, Jorge E.; Leimgruber, Peter; Dubayah, Ralph O.; Hurtt, George C.; Boehning-Gaese, Katrin; Fagan, William F.

    2014-01-01

    Long-term trends in photosynthetic capacity measured with the satellite-derived Normalized Difference Vegetation Index (NDVI) are usually associated with climate change. Human impacts on the global land surface are typically not accounted for. Here, we provide the first global analysis quantifying the effect of the earth's human footprint on NDVI trends. Globally, more than 20% of the variability in NDVI trends was explained by anthropogenic factors such as land use, nitrogen fertilization, and irrigation. Intensely used land classes, such as villages, showed the greatest rates of increase in NDVI, more than twice than those of forests. These findings reveal that factors beyond climate influence global long-term trends in NDVI and suggest that global climate change models and analyses of primary productivity should incorporate land use effects.

  7. Retrograde heart perfusion: the Langendorff technique of isolated heart perfusion.

    PubMed

    Bell, Robert M; Mocanu, Mihaela M; Yellon, Derek M

    2011-06-01

    In the late 19th century, a number of investigators were working on perfecting isolated heart model, but it was Oscar Langendorff who, in 1895, pioneered the isolated perfused mammalian heart. Since that time, the Langendorff preparation has evolved and provided a wealth of data underpinning our understanding of the fundamental physiology of the heart: its contractile function, coronary blood flow regulation and cardiac metabolism. In more recent times, the procedure has been used to probe pathophysiology of ischaemia/reperfusion and disease states, and with the dawn of molecular biology and genetic manipulation, the Langendorff perfused heart has remained a stalwart tool in the study of the impact upon the physiology of the heart by pharmacological inhibitors and targeted deletion or up-regulation of genes and their impact upon intracellular signalling and adaption to clinically relevant stressful stimuli. We present here the basic structure of the Langendorff system and the fundamental experimental rules which warrant a viable heart preparation. In addition, we discuss the use of the isolated retrograde perfused heart in the model of ischaemia-reperfusion injury ex-vivo, and its applicability to other areas of study. The Langendorff perfusion apparatus is highly adaptable and this is reflected not only in the procedure's longevity but also in the number of different applications to which it has been turned. PMID:21385587

  8. [Long-term effects of dioxin on human health and sex ratio].

    PubMed

    Iguchi, T

    2000-12-01

    Extremely high dioxins exposure has been reported in 35 men dismantled an incinerator in Osaka, Japan. The average of the serum dioxin concentration in the workers was 680 pg, the maximum concentration was 5380 pg, these values were 200-300 times higher than normal healthy Japanese men(20-30 pg). The present article reviewed long-term effects of dioxins on human health and sex ratios after accidental dioxins exposure in Seveso, Italy, based on the recently published articles. PMID:11187745

  9. A recapitulative three-dimensional model of breast carcinoma requires perfusion for multi-week growth

    PubMed Central

    Goliwas, Kayla F; Marshall, Lauren E; Ransaw, Evette L; Berry, Joel L; Frost, Andra R

    2016-01-01

    Breast carcinomas are complex, three-dimensional tissues composed of cancer epithelial cells and stromal components, including fibroblasts and extracellular matrix. In vitro models that more faithfully recapitulate this dimensionality and stromal microenvironment should more accurately elucidate the processes driving carcinogenesis, tumor progression, and therapeutic response. Herein, novel in vitro breast carcinoma surrogates, distinguished by a relevant dimensionality and stromal microenvironment, are described and characterized. A perfusion bioreactor system was used to deliver medium to surrogates containing engineered microchannels and the effects of perfusion, medium composition, and the method of cell incorporation and density of initial cell seeding on the growth and morphology of surrogates were assessed. Perfused surrogates demonstrated significantly greater cell density and proliferation and were more histologically recapitulative of human breast carcinoma than surrogates maintained without perfusion. Although other parameters of the surrogate system, such as medium composition and cell seeding density, affected cell growth, perfusion was the most influential parameter. PMID:27516850

  10. A recapitulative three-dimensional model of breast carcinoma requires perfusion for multi-week growth.

    PubMed

    Goliwas, Kayla F; Marshall, Lauren E; Ransaw, Evette L; Berry, Joel L; Frost, Andra R

    2016-01-01

    Breast carcinomas are complex, three-dimensional tissues composed of cancer epithelial cells and stromal components, including fibroblasts and extracellular matrix. In vitro models that more faithfully recapitulate this dimensionality and stromal microenvironment should more accurately elucidate the processes driving carcinogenesis, tumor progression, and therapeutic response. Herein, novel in vitro breast carcinoma surrogates, distinguished by a relevant dimensionality and stromal microenvironment, are described and characterized. A perfusion bioreactor system was used to deliver medium to surrogates containing engineered microchannels and the effects of perfusion, medium composition, and the method of cell incorporation and density of initial cell seeding on the growth and morphology of surrogates were assessed. Perfused surrogates demonstrated significantly greater cell density and proliferation and were more histologically recapitulative of human breast carcinoma than surrogates maintained without perfusion. Although other parameters of the surrogate system, such as medium composition and cell seeding density, affected cell growth, perfusion was the most influential parameter. PMID:27516850

  11. Aquaticity: A discussion of the term and of how it applies to humans.

    PubMed

    Varveri, Danae; Karatzaferi, Christina; Pollatou, Elizana; Sakkas, Giorgos K

    2016-04-01

    The relationship between humans and water and the effects on aspects related to human performance has never been studied scientifically. The aim of the current systematic review is to attempt to define the term "aquaticity", present the factors that describe it and reveal the form in which it presents itself in today's society, in order to become a distinct scientific field of study. A systematic review of the literature has been conducted using anecdotal reports from the internet and forums as well as scientific articles and books from databases on issues related to aquatic sports. To the best of our knowledge there are no scientific articles dealing with human's aquaticity. In the current systematic review, four factors have been recognized that are closely related to human aquaticity. Those are related to physical condition in the water, to apnea and ability to immerse, to mental health and to parameters related to body composition. According to our findings, "Aquaticity is the capacity of a terrestrial mammalian organism to function and habitualise in the aquatic environment. The level of aquaticity depends on mental and physical characteristics and can be improved by frequent exposure to the water element". The ideal state of aquaticity is achieved through the activation of the diving reflex, when the human body is totally immersed in water. The development of knowledge regarding the aquatic environment leads humans to an improved state of aquaticity. PMID:27210836

  12. Space Resources Development: The Link Between Human Exploration and the Long-Term Commercialization of Space

    NASA Technical Reports Server (NTRS)

    Sanders, Gerald B.

    2000-01-01

    In a letter to the NASA Administrator, Dan Goldin, in January of 1999, the Office of Management and Budget (OMB) stated the following . OMB recommends that NASA consider commercialization in a broader context than the more focused efforts to date on space station and space shuttle commercialization. We suggest that NASA examine architectures that take advantage of a potentially robust future commercial infrastructure that could dramatically lower the cost of future human exploration." In response to this letter, the NASA Human Exploration and Development of Space (HEDS) Enterprise launched the BEDS Technology & Commercialization Initiative (HTCI) to link technology and system development for human exploration with the commercial development of space to emphasize the "D" (Development) in BEDS. The development of technologies and capabilities to utilize space resources is the first of six primary focus areas in this program. It is clear that Space Resources Development (SRD) is key for both long-term human exploration of our solar system and to the long-term commercialization of space since: a) it provides the technologies, products, and raw materials to support efficient space transportation and in-space construction and manufacturing, and b) it provides the capabilities and infrastructure to allow outpost growth, self-sufficiency, and commercial space service and utility industry activities.

  13. Culture perfusion schedules influence the metabolic activity and granulocyte-macrophage colony-stimulating factor production rates of human bone marrow stromal cells.

    PubMed

    Caldwell, J; Palsson, B O; Locey, B; Emerson, S G

    1991-05-01

    The metabolic function and GM-CSF production rates of adherent human bone marrow stromal cells were investigated as functions of medium and serum feeding rates. A range of medium exchange schedules was studied, ranging from a typical Dexter culture protocol of one weekly medium exchange to a full media exchange daily, which more closely approximates what bone marrow cells experience in situ. Glucose consumption was found to be significantly higher at full daily exchange rate than at any other exchange schedule examined. However, the lactate yield on glucose was a constant, at 1.8 mol/mol, under all conditions considered. Differential serum vs. medium exchange experiment showed that both serum supply and medium nutrients were responsible for the altered behavior at high exchange rates. Glutamine consumption was found to be insignificant under all culture conditions examined. A change in exchange schedule from 50% daily medium exchange to full daily medium exchange after 14 days of culture was found to result in a transient production of GM-CSF and a change in metabolic behavior to resemble that of cultures which had full daily exchange from day one. These results suggest that both stromal cell metabolism and GM-CSF production are sensitive to medium exchange schedules. Taken together, the data presented indicate that attempts to model the function of human bone marrow in vitro may be well served by beginning with medium exchange schedules that more closely mimic the in vivo physiologic state of bone marrow. PMID:2040665

  14. As the world turns: short-term human spatial memory in egocentric and allocentric coordinates.

    PubMed

    Banta Lavenex, Pamela; Lecci, Sandro; Prêtre, Vincent; Brandner, Catherine; Mazza, Christian; Pasquier, Jérôme; Lavenex, Pierre

    2011-05-16

    We aimed to determine whether human subjects' reliance on different sources of spatial information encoded in different frames of reference (i.e., egocentric versus allocentric) affects their performance, decision time and memory capacity in a short-term spatial memory task performed in the real world. Subjects were asked to play the Memory game (a.k.a. the Concentration game) without an opponent, in four different conditions that controlled for the subjects' reliance on egocentric and/or allocentric frames of reference for the elaboration of a spatial representation of the image locations enabling maximal efficiency. We report experimental data from young adult men and women, and describe a mathematical model to estimate human short-term spatial memory capacity. We found that short-term spatial memory capacity was greatest when an egocentric spatial frame of reference enabled subjects to encode and remember the image locations. However, when egocentric information was not reliable, short-term spatial memory capacity was greater and decision time shorter when an allocentric representation of the image locations with respect to distant objects in the surrounding environment was available, as compared to when only a spatial representation encoding the relationships between the individual images, independent of the surrounding environment, was available. Our findings thus further demonstrate that changes in viewpoint produced by the movement of images placed in front of a stationary subject is not equivalent to the movement of the subject around stationary images. We discuss possible limitations of classical neuropsychological and virtual reality experiments of spatial memory, which typically restrict the sensory information normally available to human subjects in the real world. PMID:21237209

  15. Visualizing tropoelastin in a long-term human elastic fibre cell culture model

    PubMed Central

    Halm, M.; Schenke-Layland, K.; Jaspers, S.; Wenck, H.; Fischer, F.

    2016-01-01

    Elastin is an essential protein found in a variety of tissues where resilience and flexibility are needed, such as the skin and the heart. When aiming to engineer suitable implants, elastic fibres are needed to allow adequate tissue renewal. However, the visualization of human elastogenesis remains in the dark. To date, the visualization of human tropoelastin (TE) production in a human cell context and its fibre assembly under live cell conditions has not been achieved. Here, we present a long-term cell culture model of human dermal fibroblasts expressing fluorescence-labelled human TE. We employed a lentiviral system to stably overexpress Citrine-labelled TE to build a fluorescent fibre network. Using immunofluorescence, we confirmed the functionality of the Citrine-tagged TE. Furthermore, we visualized the fibre assembly over the course of several days using confocal microscopy. Applying super resolution microscopy, we were able to investigate the inner structure of the elastin–fibrillin-1 fibre network. Future investigations will allow the tracking of TE produced under various conditions. In tissue engineering applications the fluorescent fibre network can be visualized under various conditions or it serves as a tool for investigating fibre degradation processes in disease-in-a-dish-models. PMID:26842906

  16. Exosomes from human mesenchymal stem cells conduct aerobic metabolism in term and preterm newborn infants.

    PubMed

    Panfoli, Isabella; Ravera, Silvia; Podestà, Marina; Cossu, Claudia; Santucci, Laura; Bartolucci, Martina; Bruschi, Maurizio; Calzia, Daniela; Sabatini, Federica; Bruschettini, Matteo; Ramenghi, Luca Antonio; Romantsik, Olga; Marimpietri, Danilo; Pistoia, Vito; Ghiggeri, Gianmarco; Frassoni, Francesco; Candiano, Giovanni

    2016-04-01

    Exosomes are secreted nanovesicles that are able to transfer RNA and proteins to target cells. The emerging role of mesenchymal stem cell (MSC) exosomes as promoters of aerobic ATP synthesis restoration in damaged cells, prompted us to assess whether they contain an extramitochondrial aerobic respiration capacity. Exosomes were isolated from culture medium of human MSCs from umbilical cord of ≥37-wk-old newborns or between 28- to 30-wk-old newborns (i.e.,term or preterm infants). Characterization of samples was conducted by cytofluorometry. Oxidative phosphorylation capacity was assessed by Western blot analysis, oximetry, and luminometric and fluorometric analyses. MSC exosomes express functional respiratory complexes I, IV, and V, consuming oxygen. ATP synthesis was only detectable in exosomes from term newborns, suggestive of a specific mechanism that is not completed at an early gestational age. Activities are outward facing and comparable to those detected in mitochondria isolated from term MSCs. MSC exosomes display an unsuspected aerobic respiratory ability independent of whole mitochondria. This may be relevant for their ability to rescue cell bioenergetics. The differential oxidative metabolism of pretermvs.term exosomes sheds new light on the preterm newborn's clinical vulnerability. A reduced ability to repair damaged tissue and an increased capability to cope with anoxic environment for preterm infants can be envisaged.-Panfoli, I., Ravera, S., Podestà, M., Cossu, C., Santucci, L., Bartolucci, M., Bruschi, M., Calzia, D., Sabatini, F., Bruschettini, M., Ramenghi, L. A., Romantsik, O., Marimpietri, D., Pistoia, V., Ghiggeri, G., Frassoni, F., Candiano, G. Exosomes from human mesenchymal stem cells conduct aerobic metabolism in term and preterm newborn infants. PMID:26655706

  17. Long-term ecological impacts of antibiotic administration on the human intestinal microbiota.

    PubMed

    Jernberg, Cecilia; Löfmark, Sonja; Edlund, Charlotta; Jansson, Janet K

    2007-05-01

    Antibiotic administration is known to cause short-term disturbances in the microbiota of the human gastrointestinal tract, but the potential long-term consequences have not been well studied. The aims of this study were to analyse the long-term impact of a 7-day clindamycin treatment on the faecal microbiota and to simultaneously monitor the ecological stability of the microbiota in a control group as a baseline for reference. Faecal samples from four clindamycin-exposed and four control subjects were collected at nine different time points over 2 years. Using a polyphasic approach, we observed highly significant disturbances in the bacterial community that persisted throughout the sampling period. In particular, a sharp decline in the clonal diversity of Bacteroides isolates, as assessed by repetitive sequence-based PCR (rep-PCR) and long-term persistence of highly resistant clones were found as a direct response to the antibiotic exposure. The Bacteroides community never returned to its original composition during the study period as assessed using the molecular fingerprinting technique, terminal restriction fragment length polymorphism (T-RFLP). Furthermore, using real-time PCR we found a dramatic and persistent increase in levels of specific resistance genes in DNA extracted from the faeces after clindamycin administration. The temporal variations in the microbiota of the control group were minor compared to the large and persistent shift seen in the exposed group. These results demonstrate that long after the selection pressure from a short antibiotic exposure has been removed, there are still persistent long term impacts on the human intestinal microbiota that remain for up to 2 years post-treatment. PMID:18043614

  18. Store-operated Ca2+ entry in first trimester and term human placenta.

    PubMed

    Clarson, L H; Roberts, V H J; Hamark, B; Elliott, A C; Powell, T

    2003-07-15

    We have examined whether store-operated Ca2+ entry, a common pathway for Ca2+ entry in non-excitable tissue, is apparent in the syncytiotrophoblast of both first trimester and term human placenta. Expression of transient receptor potential (TRPC) homologues, a family of channels thought to be involved in store-operated Ca2+ entry, was also studied at the mRNA and protein levels. [Ca2+]i in syncytiotrophoblast of first trimester and term placental villous fragments was measured by microfluorimetry using the Ca2+-sensitive dye fura-2. Store-operated Ca2+ entry was stimulated using 1 microM thapsigargin in Ca(2+)-free Tyrode buffer (no added Ca2+ + 1 mM EGTA) followed by superfusion with control (Ca2+-containing) buffer. In term fragments, this protocol resulted in a rapid increase in [Ca2+]i, which was inhibited in the presence of 150 microM GdCl3, 200 microM NiCl2, 200 microM CoCl2 or 30 microM SKF96365 but was unaffected by addition of 10 microM nifedipine. It was not possible to stimulate such a rise in [Ca2+]i in first trimester fragments. Messenger RNA encoding TRPC1, TRPC3, TRPC4, TRPC5 and TRPC6 was identified in both first trimester and term placentas. From Western blotting, TRPC3 and TRPC6 proteins were detected in term, but not in first trimester, placentas, while TRPC1 protein was not detected. By immunocytochemistry, TRPC3 and TRPC4 were localised to cytotrophoblast cells in first trimester placentas and to the syncytiotrophoblast in term placentas. TRPC6 staining was present in the syncytiotrophoblast of both first trimester and term placenta, but the intensity was much greater in the latter. We propose that store-operated Ca2+ entry may be an important route for Ca2+ entry into the syncytiotrophoblast of term, but not first trimester placentas, and that in human placenta TRPC channels may underlie this entry mechanism. PMID:12766233

  19. Diffusion and Perfusion: The Keys to Fat Grafting

    PubMed Central

    Khouri, Roger K.; Khouri, Raoul-Emil R.; Lujan-Hernandez, Jorge R.; Khouri, Khalil R.; Lancerotto, Luca

    2014-01-01

    Background: Fat grafting is now widely used in plastic surgery. Long-term graft retention can be unpredictable. Fat grafts must obtain oxygen via diffusion until neovascularization occurs, so oxygen delivery may be the overarching variable in graft retention. Methods: We studied the peer-reviewed literature to determine which aspects of a fat graft and the microenvironment surrounding a fat graft affect oxygen delivery and created 3 models relating distinct variables to oxygen delivery and graft retention. Results: Our models confirm that thin microribbons of fat maximize oxygen transport when injected into a large, compliant, well-vascularized recipient site. The “Microribbon Model” predicts that, in a typical human, fat injections larger than 0.16 cm in radius will have a region of central necrosis. Our “Fluid Accommodation Model” predicts that once grafted tissues approach a critical interstitial fluid pressure of 9 mm Hg, any additional fluid will drastically increase interstitial fluid pressure and reduce capillary perfusion and oxygen delivery. Our “External Volume Expansion Effect Model” predicts the effect of vascular changes induced by preoperative external volume expansion that allow for greater volumes of fat to be successfully grafted. Conclusions: These models confirm that initial fat grafting survival is limited by oxygen diffusion. Preoperative expansion increases oxygen diffusion capacity allowing for additional graft retention. These models provide a scientific framework for testing the current fat grafting theories. PMID:25426403

  20. Heat stress increases long-term human migration in rural Pakistan

    NASA Astrophysics Data System (ADS)

    Mueller, V.; Gray, C.; Kosec, K.

    2014-03-01

    Human migration attributable to climate events has recently received significant attention from the academic and policy communities . Quantitative evidence on the relationship between individual, permanent migration and natural disasters is limited . A 21-year longitudinal survey conducted in rural Pakistan (1991-2012) provides a unique opportunity to understand the relationship between weather and long-term migration. We link individual-level information from this survey to satellite-derived measures of climate variability and control for potential confounders using a multivariate approach. We find that flooding--a climate shock associated with large relief efforts--has modest to insignificant impacts on migration. Heat stress, however--which has attracted relatively little relief--consistently increases the long-term migration of men, driven by a negative effect on farm and non-farm income. Addressing weather-related displacement will require policies that both enhance resilience to climate shocks and lower barriers to welfare-enhancing population movements.

  1. Assessment of the long-term risks of inadvertent human intrusion

    SciTech Connect

    Wuschke, D.M. )

    1993-01-01

    Canada has conducted an extensive research program on the safe disposal of nuclear fuel wastes. The program has focused on the concept of disposal of spent fuel in durable containers in an engineered facility, or vault, 500 to 1000 m deep in intrusive igneous rock in the Canadian Shield. An essential goal of this program has been to develop and demonstrate a methodology to evaluate the performance of the facility against safety criteria established by Canada's regulatory agency, the Atomic Energy Control Board (AECB). These criteria are expressed in terms of risk, where risk is defined as the sum over all significant scenarios of the product of the probability of the scenario, the magnitude of the resultant dose, and the probability of a health effect per unit dose. This paper describes the methodology developed to assess the long-term risk from inadvertent human intrusion into such a facility and the results of its application to a conceptual design of such a facility.

  2. Human impact on fish sensory systems in the long term: an evolutionary perspective.

    PubMed

    Zakon, Harold H

    2015-01-01

    Humans have severely impacted global ecosystems and this shows few signs of abating. Many aspects of an animal's biology, including its sensory systems, may be adversely influenced by pollutants and environmental noise. This review focuses on whether and/or how various environmental disturbances disrupt the sensory systems of fishes. As critical as it is to document and understand the current effects of the human footprint, it is also important to consider how organisms might adapt to these impacts over the long term. The present paper outlines the sources of genetic and genomic variation upon which natural selection can act and then reviews examples of known genetic contributions of variation in fish chemosensory, visual and acoustico-lateralis systems. PMID:24919803

  3. Invasiveness and Ploidy of Human Mammary Carcinomas in Short-Term Culture

    NASA Astrophysics Data System (ADS)

    Smith, Helene S.; Liotta, Lance A.; Hancock, Miriam C.; Wolman, Sandra R.; Hackett, Adeline J.

    1985-03-01

    Invasiveness and ploidy were examined in cultures of human epithelial cells derived from nonmalignant breast tissue, primary breast carcinomas, and breast cancer effusion metastases. Successful short-term culture was achieved from approximately 70% of the primary breast cancers. These primary cancers were essentially diploid by flow cytometry and karyotype in contrast to the effusion metastases, which were mostly aneuploid. The diploid tumor cells retained their malignant phenotype in culture as demonstrated by invasion into a denuded human amnion basement membrane. In contrast, epithelial cells cultured from nonmalignant mammary tissue did not invade the amnion. We suggest that the diploid carcinoma cultures may be useful for investigating the essential differences between normal and malignant cells and may complement information derived from studies of tumor cell lines with grossly aberrant karyotypes.

  4. Vanadium-mediated lipid peroxidation in microsomes from human term placenta

    SciTech Connect

    Byczkowski, J.Z.; Wan, B.; Kulkarni, A.P.

    1988-11-01

    Vanadium is considered an essential element present in living organisms in trace amounts but it is toxic when introduced in excessive doses to animals and humans. Vanadium compounds are extensively used in modern industry and occupational exposure to high doses of vanadium is quite common. In pregnant mice, vanadium accumulates preferentially in the placenta and to lower extent in fetal skeleton and mammary gland during exposure to radioactive vanadium. Accumulation of vanadium in fetoplacental unit may present threat to the fetus by interacting with enzymes and ion-transporting systems in membranes. It is also possible that accumulation of vanadium with its concomitant reduction to vanadyl may lead to lipid peroxidation, followed by damage to biological membranes, lysosomal enzymes release and destruction of placental tissue. To explore some of these possibilities the authors decided to examine whether vanadate can undergo redox cycling in microsomes from human term placenta (HTP) that can lead to lipid peroxidation.

  5. Stn1 is critical for telomere maintenance and long-term viability of somatic human cells

    PubMed Central

    Boccardi, Virginia; Razdan, Neetu; Kaplunov, Jessica; Mundra, Jyoti J; Kimura, Masayuki; Aviv, Abraham; Herbig, Utz

    2015-01-01

    Disruption of telomere maintenance pathways leads to accelerated entry into cellular senescence, a stable proliferative arrest that promotes aging-associated disorders in some mammals. The budding yeast CST complex, comprising Cdc13, Stn1, and Ctc1, is critical for telomere replication, length regulation, and end protection. Although mammalian homologues of CST have been identified recently, their role and function for telomere maintenance in normal somatic human cells are still incompletely understood. Here, we characterize the function of human Stn1 in cultured human fibroblasts and demonstrate its critical role in telomere replication, length regulation, and function. In the absence of high telomerase activity, shRNA-mediated knockdown of hStn1 resulted in aberrant and fragile telomeric structures, stochastic telomere attrition, increased telomere erosion rates, telomere dysfunction, and consequently accelerated entry into cellular senescence. Oxidative stress augmented the defects caused by Stn1 knockdown leading to almost immediate cessation of cell proliferation. In contrast, overexpression of hTERT suppressed some of the defects caused by hStn1 knockdown suggesting that telomerase can partially compensate for hStn1 loss. Our findings reveal a critical role for human Stn1 in telomere length maintenance and function, supporting the model that efficient replication of telomeric repeats is critical for long-term viability of normal somatic mammalian cells. PMID:25684230

  6. Short-term monocular deprivation alters GABA in the adult human visual cortex.

    PubMed

    Lunghi, Claudia; Emir, Uzay E; Morrone, Maria Concetta; Bridge, Holly

    2015-06-01

    Neuroplasticity is a fundamental property of the nervous system that is maximal early in life, within the critical period [1-3]. Resting GABAergic inhibition is necessary to trigger ocular dominance plasticity and to modulate the onset and offset of the critical period [4, 5]. GABAergic inhibition also plays a crucial role in neuroplasticity of adult animals: the balance between excitation and inhibition in the primary visual cortex (V1), measured at rest, modulates the susceptibility of ocular dominance to deprivation [6-10]. In adult humans, short-term monocular deprivation strongly modifies ocular balance, unexpectedly boosting the deprived eye, reflecting homeostatic plasticity [11, 12]. There is no direct evidence, however, to support resting GABAergic inhibition in homeostatic plasticity induced by visual deprivation. Here, we tested the hypothesis that GABAergic inhibition, measured at rest, is reduced by deprivation, as demonstrated by animal studies. GABA concentration in V1 of adult humans was measured using ultra-high-field 7T magnetic resonance spectroscopy before and after short-term monocular deprivation. After monocular deprivation, resting GABA concentration decreased in V1 but was unaltered in a control parietal area. Importantly, across participants, the decrease in GABA strongly correlated with the deprived eye perceptual boost measured by binocular rivalry. Furthermore, after deprivation, GABA concentration measured during monocular stimulation correlated with the deprived eye dominance. We suggest that reduction in resting GABAergic inhibition triggers homeostatic plasticity in adult human V1 after a brief period of abnormal visual experience. These results are potentially useful for developing new therapeutic strategies that could exploit the intrinsic residual plasticity of the adult human visual cortex. PMID:26004760

  7. Measuring perfusion with light (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Jansen, Sanne M. A.; de Bruin, Daniel M.; Faber, Dirk J.; van Leeuwen, Ton G.

    2016-03-01

    There is no gold standard test for perfusion evaluation in surgery. Optical Imaging techniques are able to image tissue at high resolution and in real-time. Laser Speckle Contrast Imaging, Optical Coherence Tomography, Sidestream Darkfield and Incident Darkfield all use the interaction of light with tissue to create an image. To test their feasibility and explore validity in a controlled setting, we created a phantom with the optical properties of tissue and microvascular channels of 30-400 micrometer. With a Hamilton Syringe Pump we mimicked blood flow velocities of 0-20 mm/sec. Images of all different modalities at different blood flow velocities were compared in terms of imaging depth, resoluation and hemodynamic parameters.

  8. A disposable flexible skin patch for clinical optical perfusion monitoring at multiple depths

    NASA Astrophysics Data System (ADS)

    Farkas, Dana L.; Kolodziejski, Noah J.; Stapels, Christopher J.; McAdams, Daniel R.; Fernandez, Daniel E.; Podolsky, Matthew J.; Christian, James F.; Ward, Brent B.; Vartarian, Mark; Feinberg, Stephen E.; Lee, Seung Yup; Parikh, Urmi; Mycek, Mary-Ann; Joyner, Michael J.; Johnson, Christopher P.; Paradis, Norman A.

    2016-03-01

    Stable, relative localization of source and detection fibers is necessary for clinical implementation of quantitative optical perfusion monitoring methods such as diffuse correlation spectroscopy (DCS) and diffuse reflectance spectroscopy (DRS). A flexible and compact device design is presented as a platform for simultaneous monitoring of perfusion at a range of depths, enabled by precise location of optical fibers in a robust and secure adhesive patch. We will discuss preliminary data collected on human subjects in a lower body negative pressure model for hypovolemic shock. These data indicate that this method facilitates simple and stable simultaneous monitoring of perfusion at multiple depths and within multiple physiological compartments.

  9. SPECT Myocardial Blood Flow Quantitation Concludes Equivocal Myocardial Perfusion SPECT Studies to Increase Diagnostic Benefits.

    PubMed

    Chen, Lung-Ching; Lin, Chih-Yuan; Chen, Ing-Jou; Ku, Chi-Tai; Chen, Yen-Kung; Hsu, Bailing

    2016-01-01

    Recently, myocardial blood flow quantitation with dynamic SPECT/CT has been reported to enhance the detection of coronary artery disease in human. This advance has created important clinical applications to coronary artery disease diagnosis and management for areas where myocardial perfusion PET tracers are not available. We present 2 clinical cases that undergone a combined test of 1-day rest/dipyridamole-stress dynamic SPECT and ECG-gated myocardial perfusion SPECT scans using an integrated imaging protocol and demonstrate that flow parameters are capable to conclude equivocal myocardial perfusion SPECT studies, therefore increasing diagnostic benefits to add value in making clinical decisions. PMID:26053731

  10. Perfusion from angiogram and a priori (PAP) with temporal regularization

    NASA Astrophysics Data System (ADS)

    Taguchi, Katsuyuki; Geschwind, Jean-Francois H.

    2009-02-01

    Perfusion imaging is often used for diagnosis and for assessment of the response to the treatment. If perfusion can be measured during interventional procedures, it could lead to quantitative, more efficient and accurate treatment; however, imaging modalities that allow continuous dynamic scanning are not available in most of procedure rooms. Thus, we developed a method to measure the perfusion-time attenuation curves (TACs)-of regions-of-interest (ROIs) using xray C-arm angiography system with no gantry rotation but with a priori. The previous study revealed a problem of large oscillations in the estimated TACs and the lack of comparison with CT-based approaches. Thus the purposes of this study were (1) to reduce the variance of TDCs; and (2) to compare the performance of the improved PAP with that of the CT-based perfusion method. Our computer simulation study showed that the standard deviation of PAP method was decreased by 10.7-59.0% and that it outperformed (20× or 200× times) higher dose CT methods in terms of the accuracy, variance, and the temporal resolution.

  11. Ex vivo lung graft perfusion.

    PubMed

    Briot, Raphaël; Gennai, Stéphane; Maignan, Maxime; Souilamas, Redha; Pison, Christophe

    2016-04-01

    This review proposes an update of the state of the art and the ongoing clinical trials of ex vivo lung perfusion for lung transplantation in patients. Ex vivo lung perfusion techniques (EVLP) can be used to evaluate a lung graft outside of the body. The goal of EVLP is to study the functional status of lung grafts that were first rejected for transplantation because they did not match all criteria for a conventional transplantation. After an EVLP evaluation, some of these lungs may be requalified for a possible transplantation in patients. This article proposes an overview of the developments of EVLP techniques. During EVLP, the perfusion and ventilation of the isolated lung preparation are very progressive in order to avoid oedema due to ischaemia-reperfusion injuries. Lung evaluation is mainly based on gasometric (PaO2/FiO2) and rheological criteria (low pulmonary arterial resistance). Several series of patients transplanted with EVLP evaluated lungs have been recently published with promising results. EVLP preparations also allow a better understanding of the physiopathology and treatments of ischaemia-reperfusion injuries. Organ procurements from "non-heart-beating" donors will probably require a wider application of these ex vivo techniques. The development of semi-automated systems might facilitate the clinical use of EVLP techniques. PMID:26746565

  12. Intestinal perfusion monitoring using photoplethysmography

    NASA Astrophysics Data System (ADS)

    Akl, Tony J.; Wilson, Mark A.; Ericson, M. Nance; Coté, Gerard L.

    2013-08-01

    In abdominal trauma patients, monitoring intestinal perfusion and oxygen consumption is essential during the resuscitation period. Photoplethysmography is an optical technique potentially capable of monitoring these changes in real time to provide the medical staff with a timely and quantitative measure of the adequacy of resuscitation. The challenges for using optical techniques in monitoring hemodynamics in intestinal tissue are discussed, and the solutions to these challenges are presented using a combination of Monte Carlo modeling and theoretical analysis of light propagation in tissue. In particular, it is shown that by using visible wavelengths (i.e., 470 and 525 nm), the perfusion signal is enhanced and the background contribution is decreased compared with using traditional near-infrared wavelengths leading to an order of magnitude enhancement in the signal-to-background ratio. It was further shown that, using the visible wavelengths, similar sensitivity to oxygenation changes could be obtained (over 50% compared with that of near-infrared wavelengths). This is mainly due to the increased contrast between tissue and blood in that spectral region and the confinement of the photons to the thickness of the small intestine. Moreover, the modeling results show that the source to detector separation should be limited to roughly 6 mm while using traditional near-infrared light, with a few centimeters source to detector separation leads to poor signal-to-background ratio. Finally, a visible wavelength system is tested in an in vivo porcine study, and the possibility of monitoring intestinal perfusion changes is showed.

  13. Susceptibility-Based Analysis Of Dynamic Gadolinium Bolus Perfusion MRI

    PubMed Central

    Bonekamp, David; Barker, Peter B.; Leigh, Richard; van Zijl, Peter C.M.; Li, Xu

    2014-01-01

    Purpose An algorithm is developed for the reconstruction of dynamic, gadolinium (Gd) bolus MR perfusion images of the human brain, based on quantitative susceptibility mapping (QSM). Methods The method is evaluated in 5 perfusion scans obtained from 4 different patients scanned at 3T, and compared to the conventional analysis based on changes in the transverse relaxation rate ΔR2* and to theoretical predictions. QSM images were referenced to ventricular CSF for each dynamic of the perfusion sequence. Results Images of cerebral blood flow and blood volume were successfully reconstructed from the QSM-analysis, and were comparable to those reconstructed using ΔR2*. The magnitudes of the Gd-associated susceptibility effects in gray and white matter were consistent with theoretical predictions. Conclusion QSM-based analysis may have some theoretical advantages compared to ΔR2*, including a simpler relationship between signal change and Gd concentration. However, disadvantages are its much lower contrast-to-noise ratio, artifacts due to respiration and other effects, and more complicated reconstruction methods. More work is required to optimize data acquisition protocols for QSM-based perfusion imaging. PMID:24604343

  14. Long-term culture of human odontoma-derived cells with a Rho kinase inhibitor.

    PubMed

    Uzawa, Katsuhiro; Kasamatsu, Atsushi; Saito, Tomoaki; Takahara, Toshikazu; Minakawa, Yasuyuki; Koike, Kazuyuki; Yamatoji, Masanobu; Nakashima, Dai; Higo, Morihiro; Sakamoto, Yosuke; Shiiba, Masashi; Tanzawa, Hideki

    2016-09-10

    Because of cellular senescence/apoptosis, no effective culture systems are available to maintain replication of cells from odontogenic tumors especially for odontoma, and, thus, the ability to isolate human odontoma-derived cells (hODCs) for functional studies is needed. The current study was undertaken to develop an approach to isolate hODCs and fully characterize the cells in vitro. The hODCs were cultured successfully with a Rho-associated protein kinase inhibitor (Y-27632) for an extended period with stabilized lengths of the telomeres to sustain a similar phenotype/property as the primary tumoral cells. While the hODCs showed stable long-term expansion with expression of major dental epithelial markers including dentin sialophosphoprotein (DSPP) even in the three-dimensional microenvironment, they lack the specific markers for the characteristics of stem cells. Moreover, cells from dental pulp showed significant up-regulation of DSPP when co-cultured with the hODCs, while control fibroblasts with the hODCs did not. Taken together, we propose that the hODCs can be isolated and expanded over the long term with Y-27632 to investigate not only the development of the hODCs but also other types of benign human tumors. PMID:27514999

  15. Long-Term Culture of Genome-Stable Bipotent Stem Cells from Adult Human Liver

    PubMed Central

    Huch, Meritxell; Gehart, Helmuth; van Boxtel, Ruben; Hamer, Karien; Blokzijl, Francis; Verstegen, Monique M.A.; Ellis, Ewa; van Wenum, Martien; Fuchs, Sabine A.; de Ligt, Joep; van de Wetering, Marc; Sasaki, Nobuo; Boers, Susanne J.; Kemperman, Hans; de Jonge, Jeroen; Ijzermans, Jan N.M.; Nieuwenhuis, Edward E.S.; Hoekstra, Ruurdtje; Strom, Stephen; Vries, Robert R.G.; van der Laan, Luc J.W.; Cuppen, Edwin; Clevers, Hans

    2015-01-01

    Summary Despite the enormous replication potential of the human liver, there are currently no culture systems available that sustain hepatocyte replication and/or function in vitro. We have shown previously that single mouse Lgr5+ liver stem cells can be expanded as epithelial organoids in vitro and can be differentiated into functional hepatocytes in vitro and in vivo. We now describe conditions allowing long-term expansion of adult bile duct-derived bipotent progenitor cells from human liver. The expanded cells are highly stable at the chromosome and structural level, while single base changes occur at very low rates. The cells can readily be converted into functional hepatocytes in vitro and upon transplantation in vivo. Organoids from α1-antitrypsin deficiency and Alagille syndrome patients mirror the in vivo pathology. Clonal long-term expansion of primary adult liver stem cells opens up experimental avenues for disease modeling, toxicology studies, regenerative medicine, and gene therapy. PMID:25533785

  16. Long-term modifications of synaptic efficacy in the human inferior and middle temporal cortex

    NASA Technical Reports Server (NTRS)

    Chen, W. R.; Lee, S.; Kato, K.; Spencer, D. D.; Shepherd, G. M.; Williamson, A.

    1996-01-01

    The primate temporal cortex has been demonstrated to play an important role in visual memory and pattern recognition. It is of particular interest to investigate whether activity-dependent modification of synaptic efficacy, a presumptive mechanism for learning and memory, is present in this cortical region. Here we address this issue by examining the induction of synaptic plasticity in surgically resected human inferior and middle temporal cortex. The results show that synaptic strength in the human temporal cortex could undergo bidirectional modifications, depending on the pattern of conditioning stimulation. High frequency stimulation (100 or 40 Hz) in layer IV induced long-term potentiation (LTP) of both intracellular excitatory postsynaptic potentials and evoked field potentials in layers II/III. The LTP induced by 100 Hz tetanus was blocked by 50-100 microM DL-2-amino-5-phosphonovaleric acid, suggesting that N-methyl-D-aspartate receptors were responsible for its induction. Long-term depression (LTD) was elicited by prolonged low frequency stimulation (1 Hz, 15 min). It was reduced, but not completely blocked, by DL-2-amino-5-phosphonovaleric acid, implying that some other mechanisms in addition to N-methyl-DL-aspartate receptors were involved in LTD induction. LTD was input-specific, i.e., low frequency stimulation of one pathway produced LTD of synaptic transmission in that pathway only. Finally, the LTP and LTD could reverse each other, suggesting that they can act cooperatively to modify the functional state of cortical network. These results suggest that LTP and LTD are possible mechanisms for the visual memory and pattern recognition functions performed in the human temporal cortex.

  17. Long-term impacts of unconventional drilling operations on human and animal health.

    PubMed

    Bamberger, Michelle; Oswald, Robert E

    2015-01-01

    Public health concerns related to the expansion of unconventional oil and gas drilling have sparked intense debate. In 2012, we published case reports of animals and humans affected by nearby drilling operations. Because of the potential for long-term effects of even low doses of environmental toxicants and the cumulative impact of exposures of multiple chemicals by multiple routes of exposure, a longitudinal study of these cases is necessary. Twenty-one cases from five states were followed longitudinally; the follow-up period averaged 25 months. In addition to humans, cases involved food animals, companion animals and wildlife. More than half of all exposures were related to drilling and hydraulic fracturing operations; these decreased slightly over time. More than a third of all exposures were associated with wastewater, processing and production operations; these exposures increased slightly over time. Health impacts decreased for families and animals moving from intensively drilled areas or remaining in areas where drilling activity decreased. In cases of families remaining in the same area and for which drilling activity either remained the same or increased, no change in health impacts was observed. Over the course of the study, the distribution of symptoms was unchanged for humans and companion animals, but in food animals, reproductive problems decreased and both respiratory and growth problems increased. This longitudinal case study illustrates the importance of obtaining detailed epidemiological data on the long-term health effects of multiple chemical exposures and multiple routes of exposure that are characteristic of the environmental impacts of unconventional drilling operations. PMID:25734821

  18. Transcriptomic signatures of villous cytotrophoblast and syncytiotrophoblast in term human placenta.

    PubMed

    Rouault, Christine; Clément, Karine; Guesnon, Mickael; Henegar, Corneliu; Charles, Marie-Aline; Heude, Barbara; Evain-Brion, Danièle; Degrelle, Séverine A; Fournier, Thierry

    2016-08-01

    During pregnancy, the placenta ensures multiple functions, which are directly involved in the initiation, fetal growth and outcome of gestation. The placental tissue involved in maternal-fetal exchanges and in synthesis of pregnancy hormones is the mononucleated villous cytotrophoblast (VCT) which aggregates and fuses to form and renew the syncytiotrophoblast (ST). Knowledge of the gene expression pattern specific to this endocrine and exchanges tissue of human placenta is of major importance to understand functions of this heterogeneous and complex tissue. Therefore, we undertook a global analysis of the gene expression profiles of primary cultured-VCT (n = 6) and in vitro-differentiated-ST (n = 5) in comparison with whole term placental tissue from which mononucleated VCT were isolated. A total of 880 differentially expressed genes (DEG) were observed between VCT/ST compared to whole placenta, and a total of 37 and 137 genes were significantly up and down-regulated, respectively, in VCT compared to ST. The 37 VCT-genes were involved in cellular processes (assembly, organization, and maintenance), whereas the 137 ST-genes were associated with lipid metabolism and cell morphology. In silico, all networks were linked to 3 transcriptional regulators (PPARγ, RARα and NR2F1) which are known to be essential for trophoblast differentiation. A subset of six DEG was validated by RT-qPCR and four by immunohistochemistry. To conclude, recognition of these pathways is fundamental to increase our understanding of the molecular basis of human trophoblast differentiation. The present study provides for the first time a gene expression signature of the VCT and ST compared to their originated term human placental tissue. PMID:27452442

  19. Characterization of the myometrial transcriptome and biological pathways of spontaneous human labor at term

    PubMed Central

    Mittal, Pooja; Romero, Roberto; Tarca, Adi L.; Gonzalez, Juan; Draghici, Sorin; Xu, Yi; Dong, Zhong; Nhan-Chang, Chia-Ling; Chaiworapongsa, Tinnakorn; Lye, Stephen; Kusanovic, Juan Pedro; Lipovich, Leonard; Mazaki-Tovi, Shali; Hassan, Sonia S.; Mesiano, Sam; Kim, Chong Jai

    2011-01-01

    Aims To characterize the transcriptome of human myometrium during spontaneous labor at term. Methods Myometrium was obtained from women with (n=19) and without labor (n=20). Illumina® HumanHT-12 microarrays were utilized. Moderated t-tests and False Discovery Rate adjustment of p-values were applied. qRT-PCR was performed for a select set of differentially expressed genes in a separate set of samples. ELISA and Western Blot were utilized to confirm differential protein production in a third sample set. Results 1) 471 genes were differentially expressed; 2) Gene Ontology analysis indicated enrichment of 103 biological processes and 18 molecular functions including: a) inflammatory response; b) cytokine activity; and c) chemokine activity; 3) systems biology pathway analysis using Signaling Pathway Impact Analysis indicated 6 significant pathways: a) cytokine-cytokine receptor interaction; b) Jak-Stat signaling; and c) complement and coagulation cascades; d) NOD-like receptor signaling pathway; e) Systemic Lupus Erythematosus; and f) Chemokine signaling pathway; 3) qRT-PCR confirmed over-expression of prostaglandin-endoperoxide synthase-2 (PTGS2/COX2), heparin binding EGF-like growth factor (HBEGF), chemokine C-C motif ligand 2 (CCL2/MCP1), leukocyte immunoglobulin-like receptor, subfamily A member 5 (LILRA5/LIR9), IL-8, IL-6, chemokine C-X-C motif ligand 6 (CXCL6/GCP2), nuclear factor of kappa light chain gene enhancer in B-cells inhibitor zeta (NFKBIZ), suppressor of cytokine signaling 3 (SOCS3) and decreased expression of FK506 binding-protein 5 (FKBP5) and aldehyde dehydrogenase (ALDH2) in labor; 4) IL-6, CXCL6, CCL2 and SOCS3 protein expression was significantly higher in the term labor group compared to the term not in labor group. Conclusions Myometrium of women in spontaneous labor at term is characterized by a stereotypic gene expression pattern consistent with over-expression of the inflammatory response and leukocyte chemotaxis. Differential gene

  20. Above and beyond short-term mating, long-term mating is uniquely tied to human personality.

    PubMed

    Holtzman, Nicholas S; Strube, Michael J

    2013-01-01

    To what extent are personality traits and sexual strategies linked? The literature does not provide a clear answer, as it is based on the Sociosexuality model, a one-dimensional model that fails to measure long-term mating (LTM). An improved two-dimensional model separately assesses long-term and short-term mating (STM; Jackson and Kirkpatrick, 2007). In this paper, we link this two-dimensional model to an array of personality traits (Big 5, Dark Triad, and Schizoid Personality). We collected data from different sources (targets and peers; Study 1), and from different nations (United States, Study 1; India, Study 2). We demonstrate for the first time that, above and beyond STM, LTM captures variation in personality. PMID:24342881

  1. A 3D aligned microfibrous myocardial tissue construct cultured under transient perfusion.

    PubMed

    Kenar, Halime; Kose, Gamze T; Toner, Mehmet; Kaplan, David L; Hasirci, Vasif

    2011-08-01

    The goal of this study was to design and develop a myocardial patch to use in the repair of myocardial infarctions or to slow down tissue damage and improve long-term heart function. The basic 3D construct design involved two biodegradable macroporous tubes, to allow transport of growth media to the cells within the construct, and cell seeded, aligned fiber mats wrapped around them. The microfibrous mat housed mesenchymal stem cells (MSCs) from human umbilical cord matrix (Wharton's Jelly) aligned in parallel to each other in a similar way to cell organization in native myocardium. Aligned micron-sized fiber mats were obtained by electrospinning a polyester blend (PHBV (5% HV), P(L-D,L)LA (70:30) and poly(glycerol sebacate) (PGS)). The micron-sized electrospun parallel fibers were effective in Wharton's Jelly (WJ) MSCs alignment and the cells were able to retract the mat. The 3D construct was cultured in a microbioreactor by perfusing the growth media transiently through the macroporous tubing for two weeks and examined by fluorescence microscopy for cell distribution and preservation of alignment. The fluorescence images of thin sections of 3D constructs from static and perfused cultures confirmed enhanced cell viability, uniform cell distribution and alignment due to nutrient provision from inside the 3D structure. PMID:21570112

  2. Continuous perfusion microfluidic cell culture array for high-throughput cell-based assays.

    PubMed

    Hung, Paul J; Lee, Philip J; Sabounchi, Poorya; Lin, Robert; Lee, Luke P

    2005-01-01

    We present for the first time a microfluidic cell culture array for long-term cellular monitoring. The 10 x 10 array could potentially assay 100 different cell-based experiments in parallel. The device was designed to integrate the processes used in typical cell culture experiments on a single self-contained microfluidic system. Major functions include repeated cell growth/passage cycles, reagent introduction, and real-time optical analysis. The single unit of the array consists of a circular microfluidic chamber, multiple narrow perfusion channels surrounding the main chamber, and four ports for fluidic access. Human carcinoma (HeLa) cells were cultured inside the device with continuous perfusion of medium at 37 degrees C. The observed doubling time was 1.4 +/- 0.1 days with a peak cell density of approximately 2.5*10(5) cells/cm(2). Cell assay was demonstrated by monitoring the fluorescence localization of calcein AM from 1 min to 10 days after reagent introduction. Confluent cell cultures were passaged within the microfluidic chambers using trypsin and successfully regrown, suggesting a stable culture environment suitable for continuous operation. The cell culture array could offer a platform for a wide range of assays with applications in drug screening, bioinformatics, and quantitative cell biology. PMID:15580587

  3. Long-term human response to uncertain environmental conditions in the Andes

    PubMed Central

    Dillehay, Tom D.; Kolata, Alan L.

    2004-01-01

    Human interaction with the physical environment has increasingly transformed Earth-system processes. Reciprocally, climate anomalies and other processes of environmental change of natural and anthropogenic origin have been affecting, and often disrupting, societies throughout history. Transient impact events, despite their brevity, can have significant long-term impact on society, particularly if they occur in the context of ongoing, protracted environmental change. Major climate events can affect human activities in critical conjunctures that shape particular trajectories of social development. Here we report variable human responses to major environmental events in the Andes with a particular emphasis on the period from anno Domini 500–1500 on the desert north coast of Perú. We show that preindustrial agrarian societies implemented distinct forms of anticipatory response to environmental change and uncertainty. We conclude that innovations in production strategies and agricultural infrastructures in these indigenous societies reflect differential social response to both transient (El Niño–Southern Oscillation events) and protracted (desertification) environmental change. PMID:15024122

  4. A thermoresponsive and chemically defined hydrogel for long-term culture of human embryonic stem cells

    PubMed Central

    Zhang, Rong; Mjoseng, Heidi K.; Hoeve, Marieke A.; Bauer, Nina G.; Pells, Steve; Besseling, Rut; Velugotla, Srinivas; Tourniaire, Guilhem; Kishen, Ria E. B.; Tsenkina, Yanina; Armit, Chris; Duffy, Cairnan R. E.; Helfen, Martina; Edenhofer, Frank; de Sousa, Paul A.; Bradley, Mark

    2013-01-01

    Cultures of human embryonic stem cell typically rely on protein matrices or feeder cells to support attachment and growth, while mechanical, enzymatic or chemical cell dissociation methods are used for cellular passaging. However, these methods are ill defined, thus introducing variability into the system, and may damage cells. They also exert selective pressures favouring cell aneuploidy and loss of differentiation potential. Here we report the identification of a family of chemically defined thermoresponsive synthetic hydrogels based on 2-(diethylamino)ethyl acrylate, which support long-term human embryonic stem cell growth and pluripotency over a period of 2–6 months. The hydrogels permitted gentle, reagent-free cell passaging by virtue of transient modulation of the ambient temperature from 37 to 15 °C for 30 min. These chemically defined alternatives to currently used, undefined biological substrates represent a flexible and scalable approach for improving the definition, efficacy and safety of human embryonic stem cell culture systems for research, industrial and clinical applications. PMID:23299885

  5. Comparison of syncytiotrophoblast generated from human embryonic stem cells and from term placentas

    PubMed Central

    Yabe, Shinichiro; Alexenko, Andrei P.; Amita, Mitsuyoshi; Yang, Ying; Schust, Danny J.; Ezashi, Toshihiko; Roberts, R. Michael

    2016-01-01

    Human embryonic stem cells (ESCs) readily commit to the trophoblast lineage after exposure to bone morphogenetic protein-4 (BMP-4) and two small compounds, an activin A signaling inhibitor and a FGF2 signaling inhibitor (BMP4/A83-01/PD173074; BAP treatment). During differentiation, areas emerge within the colonies with the biochemical and morphological features of syncytiotrophoblast (STB). Relatively pure fractions of mononucleated cytotrophoblast (CTB) and larger syncytial sheets displaying the expected markers of STB can be obtained by differential filtration of dispersed colonies through nylon strainers. RNA-seq analysis of these fractions has allowed them to be compared with cytotrophoblasts isolated from term placentas before and after such cells had formed syncytia. Although it is clear from extensive gene marker analysis that both ESC- and placenta-derived syncytial cells are trophoblast, each with the potential to transport a wide range of solutes and synthesize placental hormones, their transcriptome profiles are sufficiently dissimilar to suggest that the two cell types have distinct pedigrees and represent functionally different kinds of STB. We propose that the STB generated from human ESCs represents the primitive syncytium encountered in early pregnancy soon after the human trophoblast invades into the uterine wall. PMID:27051068

  6. Angiogenin distribution in human term placenta, and expression by cultured trophoblastic cells

    PubMed Central

    Pavlov, Nadine; Hatzi, Elissavet; Bassaglia, Yann; Frendo, Jean-Louis; Evain-Brion, Danièle; Badet, Josette

    2003-01-01

    Human angiogenin is a 14-kDa secreted protein with angiogenic and ribonucleolytic activities. Angiogenin is associated with tumour development but is also present in normal biological fluids and tissues. To further address the physiological role of angiogenin, we studied its expression in situ and in vitro, using the human term placenta as a model of physiological angiogenesis. Angiogenin was immunodetected by light and transmission electron microscopy, and its cellular distribution was established by double immunolabelling with cell markers including von Willebrand factor, platelet/endothelial cell adhesion molecule-1 (PECAM-1), CD34, Tie-2, vascular endothelial cadherin (VE-cadherin), vascular endothelial growth factor receptor-2 (VEGF-R2), erythropoeitin receptor (Epo-R), alpha-smooth muscle actin, CD45, cytokeratin 7, and Ki-67. Angiogenin immunoreactivity was detected in villous and extravillous trophoblasts, the trophoblast basement membrane, the endothelial basal lamina, foetal blood vessels, foetal and maternal red blood cells, and amnionic cells. Its expression was confirmed by in situ hybridisation with a digoxygenin-labelled cDNA probe and reverse transcriptase-polymerase chain reaction amplification. Villous cytotrophoblasts, isolated and differentiated in vitro into a functional syncytiotrophoblast, expressed and secreted angiogenin. Given its known biological activities in vitro and its observed pattern of expression, these data suggest that, in human placenta, angiogenin has a role not only in angiogenesis but also in vascular and tissue homeostasis, maternal immune tolerance of the foetus, and host defences. PMID:15166501

  7. Comparison of syncytiotrophoblast generated from human embryonic stem cells and from term placentas.

    PubMed

    Yabe, Shinichiro; Alexenko, Andrei P; Amita, Mitsuyoshi; Yang, Ying; Schust, Danny J; Sadovsky, Yoel; Ezashi, Toshihiko; Roberts, R Michael

    2016-05-10

    Human embryonic stem cells (ESCs) readily commit to the trophoblast lineage after exposure to bone morphogenetic protein-4 (BMP-4) and two small compounds, an activin A signaling inhibitor and a FGF2 signaling inhibitor (BMP4/A83-01/PD173074; BAP treatment). During differentiation, areas emerge within the colonies with the biochemical and morphological features of syncytiotrophoblast (STB). Relatively pure fractions of mononucleated cytotrophoblast (CTB) and larger syncytial sheets displaying the expected markers of STB can be obtained by differential filtration of dispersed colonies through nylon strainers. RNA-seq analysis of these fractions has allowed them to be compared with cytotrophoblasts isolated from term placentas before and after such cells had formed syncytia. Although it is clear from extensive gene marker analysis that both ESC- and placenta-derived syncytial cells are trophoblast, each with the potential to transport a wide range of solutes and synthesize placental hormones, their transcriptome profiles are sufficiently dissimilar to suggest that the two cell types have distinct pedigrees and represent functionally different kinds of STB. We propose that the STB generated from human ESCs represents the primitive syncytium encountered in early pregnancy soon after the human trophoblast invades into the uterine wall. PMID:27051068

  8. Ultrasound perfusion signal processing for tumor detection

    NASA Astrophysics Data System (ADS)

    Kim, MinWoo; Abbey, Craig K.; Insana, Michael F.

    2016-04-01

    Enhanced blood perfusion in a tissue mass is an indication of neo-vascularity and a sign of a potential malignancy. Ultrasonic pulsed-Doppler imaging is a preferred modality for noninvasive monitoring of blood flow. However, the weak blood echoes and disorganized slow flow make it difficult to detect perfusion using standard methods without the expense and risk of contrast enhancement. Our research measures the efficiency of conventional power-Doppler (PD) methods at discriminating flow states by comparing measurement performance to that of an ideal discriminator. ROC analysis applied to the experimental results shows that power Doppler methods are just 30-50 % efficient at perfusion flows less than 1ml/min, suggesting an opportunity to improve perfusion assessment through signal processing. A new perfusion estimator is proposed by extending the statistical discriminator approach. We show that 2-D perfusion color imaging may be enhanced using this approach.

  9. Intra-procedural Transcatheter Intraarterial Perfusion MRI as a Predictor of Tumor Response to Chemoembolization for Hepatocellular Carcinoma

    PubMed Central

    Wang, Dingxin; Gaba, Ron C.; Jin, Brian; Riaz, Ahsun; Lewandowski, Robert J.; Ryu, Robert K.; Sato, Kent T.; Ragin, Ann B.; Kulik, Laura M.; Mulcahy, Mary F.; Salem, Riad; Larson, Andrew C.; Omary, Reed A.

    2011-01-01

    Rationale and Objectives To prospectively test the hypothesis that transcatheter intraarterial perfusion magnetic resonance imaging (TRIP-MRI) measured semi-quantitative perfusion reductions during transcatheter arterial chemoembolization of hepatocellular carcinoma (HCC) are associated with tumor response. Materials and Methods Twenty eight patients (mean age 63 years; range 47–87 years) with 29 tumors underwent chemoembolization in a combined MR-interventional radiology suite. Intra-procedural tumor perfusion reductions during chemoembolization were monitored using TRIP-MRI. Pre- and post-–chemoembolization semi-quantitative area under the time-signal enhancement curve (AUC) tumor perfusion was measured. Mean tumor perfusion pre- and post-chemoembolization were compared using a paired t-test. Imaging follow-up was performed one to three months after chemoembolization. We studied the relationship between short-term tumor imaging response and intra-procedural perfusion reductions using univariate and multivariate analysis. Results Intra-procedural AUC perfusion value decreased significantly after chemoembolization (342.1 versus 158.6 arbitrary unit, P < 0.001). Twenty six patients with 27 HCCs (n = 27) had follow-up imaging at mean 39 days post-chemoembolization. Favorable response was present in 67% of these treated tumors according to necrosis criteria. 15 of 16 (94%) tumors with 25–75% perfusion reductions showed necrosis treatment response compared to only 3 of 11 (27%) tumors with perfusion reductions outside the above range (P = 0.001). Multivariate logistic regression indicated that intra-procedural tumor perfusion reduction and Child-Pugh class were independent factors associated significantly with tumor response (P = 0.012 and 0.047, respectively). Conclusion TRIP-MRI can successfully measure semi-quantitative changes in HCC perfusion during chemoembolization. Intra-procedural tumor perfusion reductions are associated with future tumor response. PMID

  10. UV exposure modulates hemidesmosome plasticity, contributing to long-term pigmentation in human skin

    PubMed Central

    Coelho, Sergio G.; Valencia, Julio C.; Yin, Lanlan; Smuda, Christoph; Mahns, Andre; Kolbe, Ludger; Miller, Sharon A.; Beer, Janusz Z.; Zhang, Guofeng; Tuma, Pamela L.; Hearing, Vincent J.

    2014-01-01

    Human skin color, i.e. pigmentation, differs widely among individuals as do their responses to various types of ultraviolet radiation (UV) and their risks of skin cancer. In some individuals UV-induced pigmentation persists for months to years in a phenomenon termed long-lasting pigmentation (LLP). It is unclear whether LLP is an indicator of potential risk for skin cancer. LLP seems to have similar features to other forms of hyperpigmentation, e.g. solar lentigines or age spots, which are clinical markers of photodamage and risk factors for precancerous lesions. To investigate what UV-induced molecular changes may persist in individuals with LLP, clinical specimens from non-sunburn-inducing repeated UV exposures (UVA, UVB or UVA+UVB) at 4 months post-exposure (short-term LLP) were evaluated by microarray analysis and dataset mining. Validated targets were further evaluated in clinical specimens from 6 healthy individuals (3 LLP+ and 3 LLP-) followed for more than 9 months (long-term LLP) who initially received a single sunburn-inducing UVA+UVB exposure. The results support a UV-induced hyperpigmentation model in which basal keratinocytes have an impaired ability to remove melanin that leads to a compensatory mechanism by neighboring keratinocytes with increased proliferative capacity to maintain skin homeostasis. The attenuated expression of SOX7 and other hemidesmosomal components (integrin α6β4 and plectin) leads to increased melanosome uptake by keratinocytes and points to a spatial regulation within the epidermis. The reduced density of hemidesmosomes provides supporting evidence for plasticity at the epidermal-dermal junction. Altered hemidesmosome plasticity, and the sustained nature of LLP, may be mediated by the role of SOX7 in basal keratinocytes. The long-term sustained subtle changes detected are modest, but sufficient to create dramatic visual differences in skin color. These results suggest that the hyperpigmentation phenomenon leading to increased

  11. Myocardial perfusion imaging using contrast echocardiography.

    PubMed

    Pathan, Faraz; Marwick, Thomas H

    2015-01-01

    Microbubbles are an excellent intravascular tracer, and both the rate of myocardial opacification (analogous to coronary microvascular perfusion) and contrast intensity (analogous to myocardial blood volume) provide unique insights into myocardial perfusion. A strong evidence base has been accumulated to show comparability with nuclear perfusion imaging and incremental diagnostic and prognostic value relative to wall motion analysis. This technique also provides the possibility to measure myocardial perfusion at the bedside. Despite all of these advantages, the technique is complicated, technically challenging, and has failed to scale legislative and financial hurdles. The development of targeted imaging and therapeutic interventions will hopefully rekindle interest in this interesting modality. PMID:25817740

  12. Estimating a regional ventilation-perfusion index

    PubMed Central

    Muller, P A; Li, T; Isaacson, D; Newell, J C; Saulnier, G J; Kao, Tzu-Jen; Ashe, Jeffrey

    2015-01-01

    This is a methods paper, where an approximation to the local ventilation-perfusion ratio is derived. This approximation, called the ventilation-perfusion index since it is not exactly the physiological ventilation-perfusion ratio, is calculated using conductivity reconstructions obtained using electrical impedance tomography. Since computation of the ventilation-perfusion index only requires knowledge of the internal conductivity, any conductivity reconstruction method may be used. The method is explained, and results are presented using conductivities obtained from two EIT systems, one using an iterative method and the other a linearization method. PMID:26006279

  13. Cortisol as a Biomarker of Stress in Term Human Labor: Physiological and Methodological Issues

    PubMed Central

    Newton, Edward R.; Tanner, Charles J.; Heitkemper, Margaret M.

    2013-01-01

    Literature on the use of plasma cortisol to quantify psychophysiological stress in humans is extensive. However, in parturition at term gestation the use of cortisol as a biomarker of stress is particularly complex. Plasma cortisol levels increase as labor progresses. This increase seems to be important for maintenance of maternal/fetal wellbeing and facilitation of normal labor progress. Unique physiological and methodological issues involved in the use of cortisol as a biomarker of stress in labor present challenges for researchers. This review examines these issues, suggests mixed methods and within-subject repeated measures designs, and offers recommendations for assay procedures for parturient sampling. Documentation of clinical interventions and delivery outcomes may elucidate relationships among psychophysiological stressors, cortisol and normal labor progress. With attention to these methodological issues, analysis of plasma cortisol may lead to clinical interventions that support normal labor physiology. PMID:23338011

  14. Neuroblast long-term cell cultures from human fetal olfactory epithelium respond to odors.

    PubMed

    Vannelli, G B; Ensoli, F; Zonefrati, R; Kubota, Y; Arcangeli, A; Becchetti, A; Camici, G; Barni, T; Thiele, C J; Balboni, G C

    1995-06-01

    Primary cell cultures from human fetal olfactory neuroepithelium have been isolated, cloned, and propagated in continuous in vitro culture for approximately 1 year. The two clones we report here synthesize both neuronal proteins and olfactory-specific markers as well as the putative olfactory neurotransmitter, carnosine. In addition, patchclamp experiments reveal that these cells are electrically excitable. Following exposure to a panel of aromatic chemicals one of the cell cultures shows a specific increase in intracellular cAMP, indicating that some degree of functional maturity is expressed in vitro. The results suggest that these cells originate from the "stem cell" compartment that gives rise to mature olfactory receptor neurons. These long-term cell cultures represent models that will be useful in studying the mechanism(s) of olfaction and the regulation of olfactory neurogenesis and differentiation. PMID:7790915

  15. Long-term survivor of human immunodeficiency virus-associated plasmablastic lymphoma.

    PubMed

    Sharma, Atul; Tilak, T V S V G K; Lodha, Rakesh; Sharma, M C; Dabkara, Deepak

    2013-04-01

    Plasmablastic lymphoma (PL) is a type of non-Hodgkin's lymphoma (NHL) having a strong association with immunosuppression, especially, human immunodeficiency virus (HIV) infection. It generally has a poor prognosis with most patients dying within 2 years from initial presentation, and long-term survivors are very few. We report the case of a 10-years-old child, presenting in 2003 with swelling on the right side of the face and fever of 2 months. Evaluation revealed a mass in the right palatal and upper alveolar region with extensive spread and bone destruction, regional adenopathy, mass lesion in the liver and hepatosplenomegaly without bone marrow involvement. Histopathology was suggestive of the PL and patient tested positive for HIV. He was started on high grade NHL chemotherapy protocol along with highly-active anti-retroviral therapy HAART. He responded well and is in complete remission since 8 years of completion of treatment and is on HAART. PMID:24049295

  16. Illicit stimulant use in humans is associated with a long-term increase in tremor.

    PubMed

    Flavel, Stanley C; Koch, Jenna D; White, Jason M; Todd, Gabrielle

    2012-01-01

    Use of illicit stimulants such as methamphetamine, cocaine, and ecstasy is a significant health problem. The United Nations Office on Drugs and Crime estimates that 14-57 million people use stimulants each year. Chronic use of illicit stimulants can cause neurotoxicity in animals and humans but the long-term functional consequences are not well understood. Stimulant users self-report problems with tremor whilst abstinent. Thus, the aim of the current study was to investigate the long-term effect of stimulant use on human tremor during rest and movement. We hypothesized that individuals with a history of stimulant use would exhibit abnormally large tremor during rest and movement. Tremor was assessed in abstinent ecstasy users (n = 9; 22 ± 3 yrs) and abstinent users of amphetamine-like drugs (n = 7; 33 ± 9 yrs) and in two control groups: non-drug users (n = 23; 27 ± 8 yrs) and cannabis users (n = 12; 24 ± 7 yrs). Tremor was measured with an accelerometer attached to the index finger at rest (30 s) and during flexion and extension of the index finger (30 s). Acceleration traces were analyzed with fast-Fourier transform. During movement, tremor amplitude was significantly greater in ecstasy users than in non-drug users (frequency range 3.9-13.3 Hz; P<0.05), but was unaffected in cannabis users or users of amphetamine-like drugs. The peak frequency of tremor did not significantly differ between groups nor did resting tremor. In conclusion, abstinent ecstasy users exhibit an abnormally large tremor during movement. Further work is required to determine if the abnormality translates to increased risk of movement disorders in this population. PMID:23272201

  17. Effects of Long Term Supplementation of Anabolic Androgen Steroids on Human Skeletal Muscle

    PubMed Central

    Yu, Ji-Guo; Bonnerud, Patrik; Eriksson, Anders; Stål, Per S.; Tegner, Yelverton; Malm, Christer

    2014-01-01

    The effects of long-term (over several years) anabolic androgen steroids (AAS) administration on human skeletal muscle are still unclear. In this study, seventeen strength training athletes were recruited and individually interviewed regarding self-administration of banned substances. Ten subjects admitted having taken AAS or AAS derivatives for the past 5 to 15 years (Doped) and the dosage and type of banned substances were recorded. The remaining seven subjects testified to having never used any banned substances (Clean). For all subjects, maximal muscle strength and body composition were tested, and biopsies from the vastus lateralis muscle were obtained. Using histochemistry and immunohistochemistry (IHC), muscle biopsies were evaluated for morphology including fiber type composition, fiber size, capillary variables and myonuclei. Compared with the Clean athletes, the Doped athletes had significantly higher lean leg mass, capillary per fibre and myonuclei per fiber. In contrast, the Doped athletes had significantly lower absolute value in maximal squat force and relative values in maximal squat force (relative to lean body mass, to lean leg mass and to muscle fiber area). Using multivariate statistics, an orthogonal projection of latent structure discriminant analysis (OPLS-DA) model was established, in which the maximal squat force relative to muscle mass and the maximal squat force relative to fiber area, together with capillary density and nuclei density were the most important variables for separating Doped from the Clean athletes (regression  =  0.93 and prediction  =  0.92, p<0.0001). In Doped athletes, AAS dose-dependent increases were observed in lean body mass, muscle fiber area, capillary density and myonuclei density. In conclusion, long term AAS supplementation led to increases in lean leg mass, muscle fiber size and a parallel improvement in muscle strength, and all were dose-dependent. Administration of AAS may induce sustained

  18. Recent Selection Changes in Human Genes under Long-Term Balancing Selection.

    PubMed

    de Filippo, Cesare; Key, Felix M; Ghirotto, Silvia; Benazzo, Andrea; Meneu, Juan R; Weihmann, Antje; Parra, Genís; Green, Eric D; Andrés, Aida M

    2016-06-01

    Balancing selection is an important evolutionary force that maintains genetic and phenotypic diversity in populations. Most studies in humans have focused on long-standing balancing selection, which persists over long periods of time and is generally shared across populations. But balanced polymorphisms can also promote fast adaptation, especially when the environment changes. To better understand the role of previously balanced alleles in novel adaptations, we analyzed in detail four loci as case examples of this mechanism. These loci show hallmark signatures of long-term balancing selection in African populations, but not in Eurasian populations. The disparity between populations is due to changes in allele frequencies, with intermediate frequency alleles in Africans (likely due to balancing selection) segregating instead at low- or high-derived allele frequency in Eurasia. We explicitly tested the support for different evolutionary models with an approximate Bayesian computation approach and show that the patterns in PKDREJ, SDR39U1, and ZNF473 are best explained by recent changes in selective pressure in certain populations. Specifically, we infer that alleles previously under long-term balancing selection, or alleles linked to them, were recently targeted by positive selection in Eurasian populations. Balancing selection thus likely served as a source of functional alleles that mediated subsequent adaptations to novel environments. PMID:26831942

  19. Short-term Cold Acclimation Recruits Brown Adipose Tissue in Obese Humans.

    PubMed

    Hanssen, Mark J W; van der Lans, Anouk A J J; Brans, Boudewijn; Hoeks, Joris; Jardon, Kelly M C; Schaart, Gert; Mottaghy, Felix M; Schrauwen, Patrick; van Marken Lichtenbelt, Wouter D

    2016-05-01

    Recruitment of brown adipose tissue (BAT) has emerged as a potential tool to combat obesity and associated metabolic complications. Short-term cold acclimation has been shown not only to enhance the presence and activity of BAT in lean humans but also to improve the metabolic profile of skeletal muscle to benefit glucose uptake in patients with type 2 diabetes. Here we examined whether short-term cold acclimation also induced such adaptations in 10 metabolically healthy obese male subjects. A 10-day cold acclimation period resulted in increased cold-induced glucose uptake in BAT, as assessed by [(18)F]fluorodeoxyglucose positron emission tomography/computed tomography. BAT activity was negatively related to age, with a similar trend for body fat percentage. In addition, cold-induced glucose uptake in BAT was positively related to glucose uptake in visceral white adipose tissue, although glucose uptake in visceral and subcutaneous white adipose tissue depots was unchanged upon cold acclimation. Cold-induced skeletal muscle glucose uptake tended to increase upon cold acclimation, which was paralleled by increased basal GLUT4 localization in the sarcolemma, as assessed through muscle biopsies. Proximal skin temperature was increased and subjective responses to cold were slightly improved at the end of the acclimation period. These metabolic adaptations to prolonged exposure to mild cold may lead to improved glucose metabolism or prevent the development of obesity-associated insulin resistance and hyperglycemia. PMID:26718499

  20. Heat Stress Increases Long-term Human Migration in Rural Pakistan

    PubMed Central

    Mueller, V.; Gray, C.; Kosec, K.

    2014-01-01

    Human migration attributable to climate events has recently received significant attention from the academic and policy communities (1-2). Quantitative evidence on the relationship between individual, permanent migration and natural disasters is limited (3-9). A 21-year longitudinal survey conducted in rural Pakistan (1991-2012) provides a unique opportunity to understand the relationship between weather and long-term migration. We link individual-level information from this survey to satellite-derived measures of climate variability and control for potential confounders using a multivariate approach. We find that flooding—a climate shock associated with large relief efforts—has modest to insignificant impacts on migration. Heat stress, however—which has attracted relatively little relief—consistently increases the long-term migration of men, driven by a negative effect on farm and non-farm income. Addressing weather-related displacement will require policies that both enhance resilience to climate shocks and lower barriers to welfare-enhancing population movements. PMID:25132865

  1. 902 MHz mobile phone does not affect short term memory in humans.

    PubMed

    Haarala, Christian; Ek, Maria; Björnberg, Linda; Laine, Matti; Revonsuo, Antti; Koivisto, Mika; Hämäläinen, Heikki

    2004-09-01

    We studied the effects of an electromagnetic field (EMF) as emitted by a 902 MHz mobile phone on human short term memory. This study was a replication with methodological improvements to our previous study. The improvements included multi-centre testing and a double blind design. A total of 64 subjects (32 men) in two independent laboratories performed a short term memory task (n-back) which poses a varying memory load (0-3 items) on the subjects' memory. They performed the task twice, once each under EMF and sham exposure. Reaction times (RTs) and accuracy of the responses were recorded. The order of exposure and memory load conditions were counterbalanced across subjects and gender. There were no statistically significant differences in performance between the two laboratories. We could not replicate our previous results: the EMF had no effect on RTs or on the accuracy of the subjects' answers. The inability to replicate previous findings could have been caused by lack of actual EMF effects or the magnitude of effects being at the sensitivity threshold of the test used. PMID:15300731

  2. Human Performance in a Realistic Instrument-Control Task during Short-Term Microgravity

    PubMed Central

    Steinberg, Fabian; Kalicinski, Michael; Dalecki, Marc; Bock, Otmar

    2015-01-01

    Previous studies have documented the detrimental effects of microgravity on human sensorimotor skills. While that work dealt with simple, laboratory-type skills, we now evaluate the effects of microgravity on a complex, realistic instrument-control skill. Twelve participants controlled a simulated power plant during the short-term microgravity intervals of parabolic flight as well as during level flight. To this end they watched multiple displays, made strategic decisions and used multiple actuators to maximize their virtual earnings from the power plant. We quantified control efficiency as the participants’ net earnings (revenue minus expenses), motor performance as hand kinematics and dynamics, and stress as cortisol level, self-assessed mood and self-assessed workload. We found that compared to normal gravity, control efficiency substantially decreased in microgravity, hand velocity slowed down, and cortisol level and perceived physical strain increased, but other stress and motor scores didn’t change. Furthermore, control efficiency was not correlated with motor and stress scores. From this we conclude that realistic instrument control was degraded in short-term microgravity. This degradation can’t be explained by the motor and/or stress indicators under study, and microgravity affected motor performance differently in our complex, realistic skill than in the simple, laboratory-type skills of earlier studies. PMID:26083473

  3. Short-term hyperoxia does not exert immunologic effects during experimental murine and human endotoxemia

    PubMed Central

    Kiers, Dorien; Gerretsen, Jelle; Janssen, Emmy; John, Aaron; Groeneveld, R.; van der Hoeven, Johannes G.; Scheffer, Gert-Jan; Pickkers, Peter; Kox, Matthijs

    2015-01-01

    Oxygen therapy to maintain tissue oxygenation is one of the cornerstones of critical care. Therefore, hyperoxia is often encountered in critically ill patients. Epidemiologic studies have demonstrated that hyperoxia may affect outcome, although mechanisms are unclear. Immunologic effects might be involved, as hyperoxia was shown to attenuate inflammation and organ damage in preclinical models. However, it remains unclear whether these observations can be ascribed to direct immunosuppressive effects of hyperoxia or to preserved tissue oxygenation. In contrast to these putative anti-inflammatory effects, hyperoxia may elicit an inflammatory response and organ damage in itself, known as oxygen toxicity. Here, we demonstrate that, in the absence of systemic inflammation, short-term hyperoxia (100% O2 for 2.5 hours in mice and 3.5 hours in humans) does not result in increased levels of inflammatory cytokines in both mice and healthy volunteers. Furthermore, we show that, compared with room air, hyperoxia does not affect the systemic inflammatory response elicited by administration of bacterial endotoxin in mice and man. Finally, neutrophil phagocytosis and ROS generation are unaffected by short-term hyperoxia. Our results indicate that hyperoxia does not exert direct anti-inflammatory effects and temper expectations of using it as an immunomodulatory treatment strategy. PMID:26616217

  4. Short-term hyperoxia does not exert immunologic effects during experimental murine and human endotoxemia.

    PubMed

    Kiers, Dorien; Gerretsen, Jelle; Janssen, Emmy; John, Aaron; Groeneveld, R; van der Hoeven, Johannes G; Scheffer, Gert-Jan; Pickkers, Peter; Kox, Matthijs

    2015-01-01

    Oxygen therapy to maintain tissue oxygenation is one of the cornerstones of critical care. Therefore, hyperoxia is often encountered in critically ill patients. Epidemiologic studies have demonstrated that hyperoxia may affect outcome, although mechanisms are unclear. Immunologic effects might be involved, as hyperoxia was shown to attenuate inflammation and organ damage in preclinical models. However, it remains unclear whether these observations can be ascribed to direct immunosuppressive effects of hyperoxia or to preserved tissue oxygenation. In contrast to these putative anti-inflammatory effects, hyperoxia may elicit an inflammatory response and organ damage in itself, known as oxygen toxicity. Here, we demonstrate that, in the absence of systemic inflammation, short-term hyperoxia (100% O2 for 2.5 hours in mice and 3.5 hours in humans) does not result in increased levels of inflammatory cytokines in both mice and healthy volunteers. Furthermore, we show that, compared with room air, hyperoxia does not affect the systemic inflammatory response elicited by administration of bacterial endotoxin in mice and man. Finally, neutrophil phagocytosis and ROS generation are unaffected by short-term hyperoxia. Our results indicate that hyperoxia does not exert direct anti-inflammatory effects and temper expectations of using it as an immunomodulatory treatment strategy. PMID:26616217

  5. Histochemical responses of human soleus muscle fibers to long-term bedrest with or without countermeasures.

    PubMed

    Ohira, Y; Yoshinaga, T; Nonaka, I; Ohara, M; Yoshioka, T; Yamashita-Goto, K; Izumi, R; Yasukawa, K; Sekiguchi, C; Shenkman, B S; Kozzlovskaya, I B

    2000-02-01

    Effects of 2- or 4-month bedrest in -6 degrees head-down tilt position with or without countermeasures on the histochemical properties of fiber phenotype and cross-sectional area (CSA) were studied in human soleus. The CSAs in slow fibers decreased approximately 32% during 4-month bedrest. This reduction was normalized after 1-month recovery. Although the reduction of percent slow fibers was not significant statistically, the percent intermediate fibers was significantly elevated 4 months after bedrest. Such shift in fiber type was not normalized following 1-month recovery. Effects of wearing an anti-g Penguin suit which has a modest, but continuous resistance at the knee and ankle (Penguin-1) or with knee resistance without loading on the ankle (Penguin-2) for 10 consecutive hours daily were also investigated during approximately 2 months of bedrest. The subjects performed knee extension and flexion for the last 15 min of each hour while in a supine position in bed. Bedrest-induced fiber atrophy was prevented in the Penguin-1 group but not the Penguin-2 group. Transformation of fiber type was not prevented in either Penguin suit group. It is suggested that long-term bedrest causes an atrophy and a shift of fiber phenotype toward fast-twitch type in human soleus. Data also indicated that loading on the muscle is an effective countermeasure for prevention of fiber atrophy but not fiber-type transformation. PMID:10866696

  6. Unsupervised Decoding of Long-Term, Naturalistic Human Neural Recordings with Automated Video and Audio Annotations.

    PubMed

    Wang, Nancy X R; Olson, Jared D; Ojemann, Jeffrey G; Rao, Rajesh P N; Brunton, Bingni W

    2016-01-01

    Fully automated decoding of human activities and intentions from direct neural recordings is a tantalizing challenge in brain-computer interfacing. Implementing Brain Computer Interfaces (BCIs) outside carefully controlled experiments in laboratory settings requires adaptive and scalable strategies with minimal supervision. Here we describe an unsupervised approach to decoding neural states from naturalistic human brain recordings. We analyzed continuous, long-term electrocorticography (ECoG) data recorded over many days from the brain of subjects in a hospital room, with simultaneous audio and video recordings. We discovered coherent clusters in high-dimensional ECoG recordings using hierarchical clustering and automatically annotated them using speech and movement labels extracted from audio and video. To our knowledge, this represents the first time techniques from computer vision and speech processing have been used for natural ECoG decoding. Interpretable behaviors were decoded from ECoG data, including moving, speaking and resting; the results were assessed by comparison with manual annotation. Discovered clusters were projected back onto the brain revealing features consistent with known functional areas, opening the door to automated functional brain mapping in natural settings. PMID:27148018

  7. Unsupervised Decoding of Long-Term, Naturalistic Human Neural Recordings with Automated Video and Audio Annotations

    PubMed Central

    Wang, Nancy X. R.; Olson, Jared D.; Ojemann, Jeffrey G.; Rao, Rajesh P. N.; Brunton, Bingni W.

    2016-01-01

    Fully automated decoding of human activities and intentions from direct neural recordings is a tantalizing challenge in brain-computer interfacing. Implementing Brain Computer Interfaces (BCIs) outside carefully controlled experiments in laboratory settings requires adaptive and scalable strategies with minimal supervision. Here we describe an unsupervised approach to decoding neural states from naturalistic human brain recordings. We analyzed continuous, long-term electrocorticography (ECoG) data recorded over many days from the brain of subjects in a hospital room, with simultaneous audio and video recordings. We discovered coherent clusters in high-dimensional ECoG recordings using hierarchical clustering and automatically annotated them using speech and movement labels extracted from audio and video. To our knowledge, this represents the first time techniques from computer vision and speech processing have been used for natural ECoG decoding. Interpretable behaviors were decoded from ECoG data, including moving, speaking and resting; the results were assessed by comparison with manual annotation. Discovered clusters were projected back onto the brain revealing features consistent with known functional areas, opening the door to automated functional brain mapping in natural settings. PMID:27148018

  8. Expression of bone morphogenetic proteins in stromal cells from human bone marrow long-term culture.

    PubMed

    Martinovic, Snjezana; Mazic, Sanja; Kisic, Veronika; Basic, Nikolina; Jakic-Razumovic, Jasminka; Borovecki, Fran; Batinic, Drago; Simic, Petra; Grgurevic, Lovorka; Labar, Boris; Vukicevic, Slobodan

    2004-09-01

    Highly purified primitive hemopoietic stem cells express BMP receptors but do not synthesize bone morphogenetic proteins (BMPs). However, exogenously added BMPs regulate their proliferation, differentiation, and survival. To further explore the mechanism by which BMPs might be involved in hemopoietic differentiation, we tested whether stromal cells from long-term culture (LTC) of normal human bone marrow produce BMPs, BMP receptors, and SMAD signaling molecules. Stromal cells were immunohistochemically characterized by the presence of lyzozyme, CD 31, factor VIII, CD 68, S100, alkaline phosphatase, and vimentin. Gene expression was analyzed by RT-PCR and the presence of BMP protein was confirmed by immunohistochemistry (IHC). The supportive role of the stromal cell layer in hemopoiesis in vitro was confirmed by a colony assay of clonogenic progenitors. Bone marrow stromal cells express mRNA and protein for BMP-3, -4, and -7 but not for BMP-2, -5, and -6 from the first to the eighth week of culture. Furthermore, stromal cells express the BMP type I receptors, activin-like kinase-3 (ALK-3), ALK-6, and the downstream transducers SMAD-1, -4, and -5. Thus, human bone marrow stromal cells synthesize BMPs, which might exert their effects on hemopoietic stem cells in a paracrine manner through specific BMP receptors. PMID:15314083

  9. Hemodynamic effects of long-term morphological changes in the human carotid sinus.

    PubMed

    Seong, Jaehoon; Jeong, Woowon; Smith, Nataliya; Towner, Rheal A

    2015-04-13

    Previous investigations of morphology for human carotid artery bifurcation from infancy to young adulthood found substantial growth of the internal carotid artery with advancing age, and the development of the carotid sinus at the root of the internal carotid artery during teenage years. Although the reasons for the appearance of the carotid sinus are not clearly understood yet, it has been hypothesized that the dilation of the carotid sinus serves to support pressure sensing, and slows the blood flow to reduce pulsatility to protect the brain. In order to understand this interesting evolvement at the carotid bifurcation in the aspects of fluid mechanics, we performed in vitro phase-contrast MR flow experiments using compliant silicone replicas of age-dependent carotid artery bifurcations. The silicone models in childhood, adolescence, and adulthood were fabricated using a rapid prototyping technique, and incorporated with a bench-top flow mock circulation loop using a computer-controlled piston pump. The results of the in vitro flow study showed highly complex flow characteristics at the bifurcation in all age-dependent models. However, the highest magnitude of kinetic energy was found at the internal carotid artery in the child model. The high kinetic energy in the internal carotid artery during childhood might be one of the local hemodynamic forces that initiate morphological long-term development of the carotid sinus in the human carotid bifurcation. PMID:25702250

  10. Long-Term Expandable SOX9+ Chondrogenic Ectomesenchymal Cells from Human Pluripotent Stem Cells

    PubMed Central

    Umeda, Katsutsugu; Oda, Hirotsugu; Yan, Qing; Matthias, Nadine; Zhao, Jiangang; Davis, Brian R.; Nakayama, Naoki

    2015-01-01

    Summary Here we report the successful generation and long-term expansion of SOX9-expressing CD271+PDGFRα+CD73+ chondrogenic ectomesenchymal cells from the PAX3/SOX10/FOXD3-expressing MIXL1−CD271hiPDGFRαloCD73− neural crest-like progeny of human pluripotent stem cells in a chemically defined medium supplemented with Nodal/Activin/transforming growth factorβ (TGFβ) inhibitor and fibroblast growth factor (FGF). When “primed” with TGFβ, such cells efficiently formed translucent cartilage particles, which were completely mineralized in 12 weeks in immunocompromized mice. The ectomesenchymal cells were expandable without loss of chondrogenic potential for at least 16 passages. They maintained normal karyotype for at least 10 passages and expressed genes representing embryonic progenitors (SOX4/12, LIN28A/B), cranial mesenchyme (ALX1/3/4), and chondroprogenitors (SOX9, COL2A1) of neural crest origin (SOX8/9, NGFR, NES). Ectomesenchyme is a source of many craniofacial bone and cartilage structures. The method we describe for obtaining a large quantity of human ectomesenchymal cells will help to model craniofacial disorders in vitro and potentially provide cells for the repair of craniofacial damage. PMID:25818812

  11. Hemodynamic Effects of Long-term Morphological Changes in the Human Carotid Sinus

    PubMed Central

    Seong, Jaehoon; Jeong, Woowon; Smith, Nataliya; Towner, Rheal A.

    2015-01-01

    Previous investigations of morphology for human carotid artery bifurcation from infancy to young adulthood found substantial growth of the internal carotid artery with advancing age, and the development of the carotid sinus at the root of the internal carotid artery during teen age years. Although the reasons for the appearance of the carotid sinus are not clearly understood yet, it has been hypothesized that the dilation of the carotid sinus serves to support pressure sensing, and slows the blood flow to reduce pulsatility to protect the brain. In order to understand this interesting evolvement at the carotid bifurcation in the aspects of fluid mechanics, we performed in vitro phase-contrast MR flow experiments using compliant silicone replicas of age-dependent carotid artery bifurcations. The silicone models in childhood, adolescence, and adulthood were fabricated using a rapid prototyping technique, and incorporated with a bench-top flow mock circulation loop using a computer-controlled piston pump. The results of the in vitro flow study showed highly complex flow characteristics at the bifurcation in all age-dependent models. However, the highest magnitude of kinetic energy was found at the internal carotid artery in the child model. The high kinetic energy in the internal carotid artery during childhood might be one of the local hemodynamic forces that initiate morphological long-term development of the carotid sinus in the human carotid bifurcation. PMID:25702250

  12. Long-term expandable SOX9+ chondrogenic ectomesenchymal cells from human pluripotent stem cells.

    PubMed

    Umeda, Katsutsugu; Oda, Hirotsugu; Yan, Qing; Matthias, Nadine; Zhao, Jiangang; Davis, Brian R; Nakayama, Naoki

    2015-04-14

    Here we report the successful generation and long-term expansion of SOX9-expressing CD271(+)PDGFRα(+)CD73(+) chondrogenic ectomesenchymal cells from the PAX3/SOX10/FOXD3-expressing MIXL1(-)CD271(hi)PDGFRα(lo)CD73(-) neural crest-like progeny of human pluripotent stem cells in a chemically defined medium supplemented with Nodal/Activin/transforming growth factorβ (TGFβ) inhibitor and fibroblast growth factor (FGF). When "primed" with TGFβ, such cells efficiently formed translucent cartilage particles, which were completely mineralized in 12 weeks in immunocompromized mice. The ectomesenchymal cells were expandable without loss of chondrogenic potential for at least 16 passages. They maintained normal karyotype for at least 10 passages and expressed genes representing embryonic progenitors (SOX4/12, LIN28A/B), cranial mesenchyme (ALX1/3/4), and chondroprogenitors (SOX9, COL2A1) of neural crest origin (SOX8/9, NGFR, NES). Ectomesenchyme is a source of many craniofacial bone and cartilage structures. The method we describe for obtaining a large quantity of human ectomesenchymal cells will help to model craniofacial disorders in vitro and potentially provide cells for the repair of craniofacial damage. PMID:25818812

  13. Absence of short-term effects of UMTS exposure on the human auditory system.

    PubMed

    Parazzini, Marta; Lutman, Mark E; Moulin, Annie; Barnel, Cécile; Sliwinska-Kowalska, Mariola; Zmyslony, Marek; Hernadi, Istvan; Stefanics, Gabor; Thuroczy, Gyorgy; Ravazzani, Paolo

    2010-01-01

    The aim of this study, which was performed in the framework of the European project EMFnEAR, was to investigate the potential effects of Universal Mobile Telecommunications System (UMTS, also known as 3G) exposure at a high specific absorption rate (SAR) on the human auditory system. Participants were healthy young adults with no hearing or ear disorders. Auditory function was assessed immediately before and after exposure to radiofrequency (RF) radiation, and only the exposed ear was tested. Tests for the assessment of auditory function were hearing threshold level (HTL), distortion product otoacoustic emissions (DPOAE), contralateral suppression of transiently evoked otoacoustic emission (CAS effect on TEOAE), and auditory evoked potentials (AEP). The exposure consisted of speech at a typical conversational level delivered via an earphone to one ear, plus genuine or sham RF-radiation exposure obtained by an exposure system based on a patch antenna and controlled by software. Results from 73 participants did not show any consistent pattern of effects on the auditory system after a 20-min UMTS exposure at 1947 MHz at a maximum SAR over 1 g of 1.75 W/kg at a position equivalent to the cochlea. Analysis entailed a double-blind comparison of genuine and sham exposure. It is concluded that short-term UMTS exposure at this relatively high SAR does not cause measurable immediate effects on the human auditory system. PMID:20041763

  14. Serum from humans on long-term calorie restriction enhances stress resistance in cell culture.

    PubMed

    Omodei, Daniela; Licastro, Danilo; Salvatore, Francesco; Crosby, Seth D; Fontana, Luigi

    2013-08-01

    Calorie restriction (CR) without malnutrition is the most robust intervention to slow aging and extend healthy lifespan in experimental model organisms. Several metabolic and molecular adaptations have been hypothesized to play a role in mediating the anti-aging effects of CR, including enhanced stress resistance, reduced oxidative stress and several neuroendocrine modifications. However, little is known about the independent effect of circulating factors in modulating key molecular pathways. In this study, we used sera collected from individuals practicing long-term CR and from age- and sex-matched individuals on a typical US diet to culture human primary fibroblasts and assess the effects on gene expression and stress resistance. We show that treatment of cultured cells with CR sera caused increased expression of stress-response genes and enhanced tolerance to oxidants. Cells cultured in serum from CR individuals showed a 30% increase in resistance to H2O2 damage. Consistently, SOD2 and GPX1 mRNA, two key endogenous antioxidant enzymes, were increased by 2 and 2.5 folds respectively in cells cultured with CR sera. These cellular and molecular adaptations mirror some of the key effects of CR in animals, and further suggest that circulating factors contribute to the CR-mediated protection against oxidative stress and stress-response in humans as well. PMID:23912304

  15. Differential expression of human placental neurotrophic factors in preterm and term deliveries.

    PubMed

    Dhobale, Madhavi V; Pisal, Hemlata R; Mehendale, Savita S; Joshi, Sadhana R

    2013-12-01

    Neurotrophic factors such as brain derived neurotrophic factor (BDNF) and nerve growth factor (NGF) are involved in development of the placenta and fetal brain. A series of human and animal studies in our department have shown that micronutrients (folic acid, vitamin B12) and omega 3 fatty acids like DHA are all interlinked in the one carbon cycle. Any alterations in one carbon components will lead to changes in methylation patterns that further affect the gene expression at critical periods of development resulting in complications during pregnancy. This may further contribute to risk for neurodevelopmental disorders in children born preterm. Therefore this study for the first time examines the mRNA levels from preterm and term placentae. A total number of 38 women delivering preterm (<37 weeks gestation) and 37 women delivering at term (=>37 weeks gestation) were recruited. The mRNA levels of BDNF and NGF were analyzed by real time quantitative polymerase chain reaction. Our results indicate that BDNF and NGF mRNA levels were lower in preterm group as compared to term group. There was a positive association of placental BDNF and NGF mRNA levels with cord plasma BDNF and NGF levels. The differential expression of BDNF and NGF gene in preterm placentae may also alter the vascular development in preterm deliveries. Our data suggests that the reduced mRNA levels of BDNF and NGF may possibly be a result of altered epigenetic mechanisms and may have an implication for altered fetal programming in children born preterm. PMID:24076518

  16. Assessment of myocardial perfusion in patients after the arterial switch operation

    SciTech Connect

    Vogel, M.; Smallhorn, J.F.; Gilday, D.; Benson, L.N.; Ash, J.; Williams, W.G.; Freedom, R.M. )

    1991-02-01

    In 21 patients who had undergone the arterial switch operation, the adequacy of myocardial perfusion was evaluated by thallium-201 computed scintigraphy 2.6 +/- 2 (0.3-7) yr after surgery. Fourteen patients had undergone the arterial switch procedure after pulmonary artery banding and seven as a primary repair. Isoproterenol stress increased the heart rate by at least 55%. Tomographic imaging was performed at peak stress and 3 hr later in the reperfusion phase. Nine patients had perfusion defects. The perfusion defects were located at the left ventricular apex in four (with extension to the inferolateral wall in one), left ventricular anterolateral wall in two, ventricular septum in one, left ventricular inferior wall in one, and right ventricular free wall in one. Some of these defects could be due to myocardial damage at the time of surgery, but these results also raise concern about long-term adequacy of myocardial perfusion following the arterial switch procedure.

  17. Long-term facilitation of genioglossus activity is present in normal humans during NREM sleep

    PubMed Central

    Chowdhuri, Susmita; Pierchala, Lisa; Aboubakr, Salah E.; Shkoukani, Mahdi; Badr, M. Safwan

    2008-01-01

    Episodic hypoxia (EH) is followed by increased ventilatory motor output in the recovery period indicative of long-term facilitation (LTF). We hypothesized that episodic hypoxia evokes LTF of genioglossus (GG) muscle activity in humans during non-rapid eye movement sleep (NREM) sleep. We studied 12 normal non-flow limited humans during stable NREM sleep. We induced 10 brief (3 minute) episodes of isocapnic hypoxia followed by 5 minutes of room air. Measurements were obtained during control, hypoxia, and at 5, 10, 20, 30 and 40 minutes of recovery, respectively, for minute ventilation (V̇I), supraglottic pressure (PSG), upper airway resistance (RUA) and phasic GG electromyogram (EMGGG). In addition, sham studies were conducted on room air. During hypoxia there was a significant increase in phasic EMGGG (202.7±24.1% of control, p<0.01) and in V̇I (123.0±3.3% of control, p<0.05); however, only phasic EMGGG demonstrated a significant persistent increase throughout recovery (198.9±30.9%, 203.6±29.9% and 205.4±26.4% of control, at 5, 10, and 20 minutes of recovery, respectively, p<0.01). In multivariate regression analysis, age and phasic EMGGG activity during hypoxia were significant predictors of EMGGG at recovery 20 minutes. No significant changes in any of the measured parameters were noted during sham studies. Conclusion: 1) EH elicits LTF of GG in normal non-flow limited humans during NREM sleep, without ventilatory or mechanical LTF. 2) GG activity during the recovery period correlates with the magnitude of GG activation during hypoxia, and inversely with age. PMID:17945544

  18. Myocardial perfusion with rubidium-82. III. Theory relating severity of coronary stenosis to perfusion deficit

    SciTech Connect

    Mullani, N.A.

    1984-11-01

    The relation between the quantitative perfusion deficit, as measured by emission computerized tomography, and the severity of coronary artery stenosis is important for the noninvasive clinical evaluation of coronary artery disease in man. Positron emission tomography allows direct noninvasive measurement of myocardial perfusion and quantification of the size of the perfusion defect. Given this important imformation, a mathematical model has been derived to gauge the severity of a coronary stenosis from quantitative perfusion measurements in the normal and poststenotic regions of the heart. The theoretical basis is presented for relating regional myocardial perfusion and regional perfusion resistance to total, coronary blood flow and resistance at normal resting flow and during maximal coronary vasodilation. The concept of perfusion reserve is presented as a clinical measure of the severity of a stenosis.

  19. Dopaminergic Therapy Modulates Cortical Perfusion in Parkinson Disease With and Without Dementia According to Arterial Spin Labeled Perfusion Magnetic Resonance Imaging

    PubMed Central

    Lin, Wei-Che; Chen, Pei-Chin; Huang, Yung-Cheng; Tsai, Nai-Wen; Chen, Hsiu-Ling; Wang, Hung-Chen; Lin, Tsu-Kung; Chou, Kun-Hsien; Chen, Meng-Hsiang; Chen, Yi-Wen; Lu, Cheng-Hsien

    2016-01-01

    Abstract Arterial spin labeling (ASL) magnetic resonance imaging analyses allow for the quantification of altered cerebral blood flow, and provide a novel means of examining the impact of dopaminergic treatments. The authors examined the cerebral perfusion differences among 17 Parkinson disease (PD) patients, 17 PD with dementia (PDD) patients, and 17 healthy controls and used ASL-MRI to assess the effects of dopaminergic therapies on perfusion in the patients. The authors demonstrated progressive widespread cortical hypoperfusion in PD and PDD and robust effects for the dopaminergic therapies. Specifically, dopaminergic medications further decreased frontal lobe and cerebellum perfusion in the PD and PDD groups, respectively. These patterns of hypoperfusion could be related to cognitive dysfunctions and disease severity. Furthermore, desensitization to dopaminergic therapies in terms of cortical perfusion was found as the disease progressed, supporting the concept that long-term therapies are associated with the therapeutic window narrowing. The highly sensitive pharmaceutical response of ASL allows clinicians and researchers to easily and effectively quantify the absolute perfusion status, which might prove helpful for therapeutic planning. PMID:26844450

  20. Short-term dietary nitrate supplementation augments cutaneous vasodilatation and reduces mean arterial pressure in healthy humans.

    PubMed

    Keen, Jeremy T; Levitt, Erica L; Hodges, Gary J; Wong, Brett J

    2015-03-01

    Nitrate supplementation in the form of beetroot juice has been shown to increase nitric oxide (NO) where nitrate can be reduced to nitrite and, subsequently, to NO through both nitric oxide synthase (NOS)-dependent and -independent pathways. We tested the hypothesis that nitrate supplementation would augment the NO component of the cutaneous vasodilatation to local skin heating in young, healthy humans. Participants reported to the lab for pre- and post-supplement local heating protocols. Nitrate supplementation consisted of one shot (70 ml) of beetroot juice (0.45 g nitrate; 5mM) for three days. Six participants were equipped with two microdialysis fibers on the ventral forearm and randomly assigned to lactated Ringer's (control) or continuous infusion of 20mM l-NAME (NOS inhibitor). The control site was subsequently perfused with l-NAME once a plateau in skin blood flow was achieved to quantify NOS-dependent cutaneous vasodilatation. Skin blood flow via laser-Doppler flowmetry (LDF) and mean arterial pressure (MAP) were measured; cutaneous vascular conductance (CVC) was calculated as LDF/MAP and normalized to %CVCmax. Beetroot juice reduced MAP (Pre: 90 ± 1 mmHg vs. Post: 83 ± 1 mmHg) and DBP (Pre: 74 ± 2 mmHg vs. Post: 62 ± 3 mmHg) (P<0.05). The plateau phase of the local heating response at control sites was augmented post-beetroot juice (91 ± 5%CVCmax) compared to pre-beetroot juice (79 ± 2%CVCmax) (P<0.05). There was no difference in the %NOS-dependent vasodilatation from pre- to post-beetroot juice. These data suggest that nitrate supplementation via beetroot juice can reduce MAP and DBP as well as augment NOS-independent vasodilatation to local heating in the cutaneous vasculature of healthy humans. PMID:25554360

  1. Long term PM2.5 estimation and its impact on human health in Beijing, China

    NASA Astrophysics Data System (ADS)

    Zheng, Sheng; Pozzer, Andrea; Cao, Chunxiang

    2014-05-01

    Due to the economic growth and urbanization, the emissions of pollutants have increased significantly in the North China Plain (NCP). Beijing, the capital of China, is located at the northern tip of NCP, and it is considered one of the most densely populated cities with the poorest air quality. This is of major concerns, because of the impact of high pollutants concentration on human health. The present study analyses the characteristics of AOD and the particulate matter with diameter < 2.5 μm (PM2.5) and its impact on human health in the central Beijing areas. We acquire AOD from Aerosol Robotic Network (AERONET) in Beijing from 2001 to 2012. The AOD data are fitted with a lognormal distribution, and the 95% of the cumulative probability is used as the threshold for episodes of high AOD. Most episodes occur in summer, mostly in June, though this is combined with high precipitation. Episodes of high AOD caused by coarse pollutants occur only in March and April, and they are mostly caused by dust from the north. According to wind direction, wind speed, boundary layer height (BLH) and pollutant emission distribution, episodes of high AOD are due to the anthropogenic pollutants from the south (Hebei province). Based on ground PM2.5 observation from the US embassy in Beijing from 2010 to 2011, we establish a relationship between PM2.5and AERONET AOD, including BLH and relative humidity (RH) correction. Thanks to this method, 12 years of PM2.5 are estimated for the Beijing central area, allowing the estimation of long term concentrations of this pollutant. Since there is no obvious difference among the daily PM2.5 of six stations lying in Chaoyang, Dongcheng, and Xicheng district, we use the daily PM2.5 from US embassy station to represent the PM2.5 concentration in these three districts, and calculate yearly premature mortality due to long term exposure to PM2.5among the population with an age of ≥ 30 yr in these three districts.

  2. Human cytomegalovirus gene expression in long-term infected glioma stem cells.

    PubMed

    Fiallos, Estefania; Judkins, Jonathon; Matlaf, Lisa; Prichard, Mark; Dittmer, Dirk; Cobbs, Charles; Soroceanu, Liliana

    2014-01-01

    The most common adult primary brain tumor, glioblastoma (GBM), is characterized by fifteen months median patient survival and has no clear etiology. We and others have identified the presence of human cytomegalovirus (HCMV) gene products endogenously expressed in GBM tissue and primary cells, with a subset of viral genes being consistently expressed in most samples. Among these viral genes, several have important oncomodulatory properties, regulating tumor stemness, proliferation, immune evasion, invasion and angiogenesis. These findings lead us to hypothesize that a specific HCMV gene signature may be associated with GBM pathogenesis. To investigate this hypothesis, we used glioma cell lines and primary glioma stem-like cells (GSC) infected with clinical and laboratory HCMV strains and measured relative viral gene expression levels along several time points up to 15 weeks post-infection. While HCMV gene expression was detected in several infected glioma lines through week 5 post-infection, only HCMV-infected GSC expressed viral gene products 15 weeks post-infection. Efficiency of infection across time was higher in GSC compared to cell lines. Importantly, HCMV-infected GSC outlived their uninfected counterparts, and this extended survival was paralleled by increased tumorsphere frequency and upregulation of stemness regulators, such as SOX2, p-STAT3, and BMX (a novel HCMV target identified in this study). Interleukin 6 (IL-6) treatment significantly upregulated HCMV gene expression in long-term infected glioma cultures, suggesting that pro-inflammatory signaling in the tumor milieu may further augment HCMV gene expression and subsequent tumor progression driven by viral-induced cellular signaling. Together, our data support a critical role for long-term, low-level HCMV infection in promoting survival, stemness, and proliferation of GSC that could significantly contribute to GBM pathogenesis. PMID:25549333

  3. Molecular and Immunohistochemical Characterization of Historical Long-Term Preserved Fixed Tissues from Different Human Organs.

    PubMed

    Hühns, Maja; Röpenack, Paula; Erbersdobler, Andreas

    2015-01-01

    University and museum collections are very important sources of biological samples that can be used to asses the past and present genetic diversity of many species. Modern genetic and immunohistochemical techniques can be used on long-term preserved fixed tissues from museum specimens to answer epidemiological questions. A proof of principle was established to apply modern molecular genetics and immunohistochemical methods to these old specimens and to verify the original diagnosis. We analysed 19 specimens from our university collection including human organs that had been in fixative for more than 80 years. The tissues originated from lung, colon, brain, heart, adrenal gland, uterus and skin. We isolated amplifiable DNA from these wet preparations and performed mutational analysis of BRAF, KRAS and EGFR. The tissues were also embedded in paraffin and used for modern histology and immunohistochemistry. Our data show that amplifiable DNA is extractable and ranged from 0.25 to 22.77 μg of total DNA. In three specimens BRAFV600E or KRASG12D mutations were found. Additionally, expression of different proteins like vimentin and GFAP was detected immunohistochemical in six investigated specimens. On the basis of our results the original diagnosis was altered in three specimens. Our work showed that it is possible to extract amplifiable DNA suitable for sequence analysis from long-term fixed tissue. Furthermore, histology and immunohistochemistry is feasible in specimens fixed long time ago. We conclude that these old preparations are suitable for further epidemiological research and that our methods open up new opportunities for future studies. PMID:26252375

  4. Hydrostatic Isolated Limb Perfusion with Adeno-associated Virus Vectors Enhances Correction of Skeletal Muscle in Pompe Disease

    PubMed Central

    Sun, Baodong; Li, Songtao; Bird, Andrew; Koeberl, Dwight D.

    2010-01-01

    Glycogen storage disease type II (GSD-II; Pompe disease; MIM 232300) stems from the inherited deficiency of acid-α-glucosidase (GAA; acid maltase; EC 3.2.1.20), which primarily involves cardiac and skeletal muscles. We hypothesized that hydrostatic isolated limb perfusion (ILP) administration of an adeno-associated virus (AAV) vector containing a muscle specific promoter could achieve relatively higher transgene expression in the hindlimb muscles of GAA-knockout (GAA-KO) mice, in comparison with intravenous (IV) administration. ILP adminstration of AAV2/8 vectors encoding alkaline phosphatase or human GAA transduced skeletal muscles of the hindlimb widely, despite the relatively low number of vector particles administered (1×1011), and IV administration of an equivalent vector dose failed to transduce skeletal muscle detectably. Similarly, ILP administration of fewer vector particles of the AAV2/9 vector encoding human GAA (3×1010) transduced skeletal muscles of the hindlimb widely and significantly reduced glycogen content to, in comparison with IV administration. The only advantage for IV administration was moderately high level transduction of cardiac muscle, which demonstrated compellingly that ILP administration sequestered vector particles within the perfused limb. Reduction of glycogen storage in the extensor digitorum longus demonstrated the potential advantage of ILP-mediated delivery of AAV vectors in Pompe disease, because type II myofibers are resistant to enzyme replacement therapy. Thus, ILP will enhance AAV transduction of multiple skeletal muscles while reducing the required dosages in terms of vector particle numbers. PMID:20686508

  5. FUNDAMENTAL AREAS OF PHENOMENOLOGY(INCLUDING APPLICATIONS): Effects of Different Zernike Terms on Optical Quality and Vision of Human Eyes

    NASA Astrophysics Data System (ADS)

    Zhao, Rao-Xin; Xu, Bing; Li, Jing; Dai, Yun; Yu, Xiang; Zhang, Yu-Dong; Jiang, Wen-Han

    2009-05-01

    The visual quality of human eyes is much restricted by high-order aberrations as well as low-order aberrations (defocus and astigmatism), but each term of high-order aberrations contributes differently. The visual acuity and contrast of the image on the retina can be gained by inducing aberrations to each term of high orders. Based on an adaptive optics system, the visual acuity of four subjects is tested by inducing aberrations to each Zernike term after correcting all the aberrations of the subjects. Zernike terms near the center of the Zernike tree affect visual quality more than those near the edge both theoretically and experimentally, and 0.1-μm aberration of these terms can clearly degrade the optical quality and vision. The results suggest that correcting the terms near the center of Zernike tree can improve the visual quality effectively in practice.

  6. Long-term variability and impact on human health of biologically active UV radiation in Moscow

    NASA Astrophysics Data System (ADS)

    Zhdanova, Ekaterina; Chubarova, Natalia

    2014-05-01

    the developed classification for Moscow. Booth, C.R. and S. Madronich, 1994: Radiation amplification factors: improved formulation accounts for large increases in ultraviolet radiation associated with Antarctic ozone depletion. In: Ultraviolet Radiation in Antarctica: Measurements and Biological Research [Weiler, C.S. and P.A. Penhale (eds.)]. AGU Antarctic Research Series, 62, Washington, DC, USA, 39-42. Chubarova N.Y., 2008: UV variability in Moscow according to long-term UV measurements and reconstruction model. Atmos.Chem.Phys., 8, 3025-3031 Oriowo, M. et al., 2001:, Action spectrum for in vitro UV-induced cataract using whole lenses. Invest.Ophthalmol.&Vis.Sci, 42, 2596-2602. CIE, 1993: Reference Action Spectra for Ultraviolet Induced Erythema and Pigmentation of Different Human skin Types. CIE Research Note, CIE Technical Collection., N.3 CIE, 2006: Action spectrum for the production of previtamin D3 in human skin, Technical report 174, International commission on illumination

  7. Ectopic Bone Formation by Mesenchymal Stem Cells Derived from Human Term Placenta and the Decidua

    PubMed Central

    Gronthos, Stan; Manuelpillai, Ursula; Abumaree, Mohamed H.; Pertile, Mark D.; Brennecke, Shaun P.; Kalionis, Bill

    2015-01-01

    Mesenchymal stem cells (MSCs) are one of the most attractive cell types for cell-based bone tissue repair applications. Fetal-derived MSCs and maternal-derived MSCs have been isolated from chorionic villi of human term placenta and the decidua basalis attached to the placenta following delivery, respectively. Chorionic-derived MSCs (CMSCs) and decidua-derived MSCs (DMSCs) generated in this study met the MSCs criteria set by International Society of Cellular Therapy. These criteria include: (i) adherence to plastic; (ii) >90% expression of CD73, CD105, CD90, CD146, CD44 and CD166 combined with <5% expression of CD45, CD19 and HLA-DR; and (iii) ability to differentiate into osteogenic, adipogenic, and chondrogenic lineages. In vivo subcutaneous implantation into SCID mice showed that both bromo-deoxyuridine (BrdU)-labelled CMSCs and DMSCs when implanted together with hydroxyapatite/tricalcium phosphate particles were capable of forming ectopic bone at 8-weeks post-transplantation. Histological assessment showed expression of bone markers, osteopontin (OPN), osteocalcin (OCN), biglycan (BGN), bone sialoprotein (BSP), and also a marker of vasculature, alpha-smooth muscle actin (α-SMA). This study provides evidence to support CMSCs and DMSCs as cellular candidates with potent bone forming capacity. PMID:26484666

  8. Long term organ culture of human prostate tissue in a NASA-designed rotating wall bioreactor

    NASA Technical Reports Server (NTRS)

    Margolis, L.; Hatfill, S.; Chuaqui, R.; Vocke, C.; Emmert-Buck, M.; Linehan, W. M.; Duray, P. H.

    1999-01-01

    PURPOSE: To maintain ex vivo integral prostatic tissue including intact stromal and ductal elements using the NASA-designed Rotating Wall Vessel (RWV) which maintains colocalized cells in an environment that promotes both three-dimensional cellular interactions together with the uniform mass transfer of nutrients and metabolic wastes. MATERIALS AND METHODS: Samples of normal prostate were obtained as a byproduct of transurethral prostatectomy or needle biopsy. Prostatic tissue dissected into small 1 x 1 mm. blocks was cultured in the Rotating Wall Vessel (RWV) Bioreactor for various time periods and analyzed using histological, immunochemical, and total cell RNA assays. RESULTS: We report the long term maintenance of benign explanted human prostate tissue grown in simple culture medium, under the simulated microgravity conditions afforded by the RWV bioreactor. Mesenchymal stromal elements including blood vessels and architecturally preserved tubuloglandular acini were maintained for a minimum of 28 days. Cytokeratins, vimentin and TGF-beta2 receptor and ligand were preserved through the entire culture period as revealed by immunocytochemistry. Prostatic acid phosphatase (PAP) was continuously expressed during the culture period, although somewhat decreased. Prostatic specific antigen (PSA) and its transcript were down regulated over time of culture. Prostatic carcinoma cells from the TSU cell line were able to invade RWV-cultured benign prostate tissue explants. CONCLUSIONS: The RWV bioreactor represents an additional new technology for culturing prostate tissue for further investigations concerning the basic physiology and pathobiology of this clinically important tissue.

  9. Long-term effects of prenatal x-ray of human females: mortality and morbidity

    SciTech Connect

    Meyer, M.B.; Tonascia, J.

    1981-09-01

    Experimental studies and long-term studies of humans exposed to ionizing radiation in utero and after birth show that these exposures increase the risk of cancer in childhood and in later life. A possible life-shortening effect has also been reported. This study followed to their mid-twenties 1458 women exposed in utero to diagnostic x-rays and 1458 matched, unexposed controls in Baltimore, Maryland, and obtained responses from over 100 women in each group. Information about general health and specific diseases was obtained from questionnaires. Deaths were ascertained through family members and death certificates. Mortality rates were slightly higher among exposure. Exposed women reported poor general health significantly more often than controls. Specific diseases occurred similarly in the two groups, although exposed women reported more epilepsy or fits, more ovarian tumors, and more high blood pressure. These strong correlation between weight and high blood pressure and the heavier weights of exposed women seemed to account for this difference. In summary, these matched exposed and control women, followed to their mid-twenties, experienced similar rates of morbidity and mortality. Radiation-induced cancers and life-shortening effects, if any, might not become evident until older ages.

  10. Effect of sexual behavior change on long-term human immunodeficiency virus prevalence among homosexual men.

    PubMed

    Morris, M; Dean, L

    1994-08-01

    Substantial changes in human immunodeficiency virus (HIV)-related sexual behavior have been reported by virtually every survey of homosexual/bisexual men in the last decade. This paper uses a behavior-based simulation to examine how such changes are likely to affect the long-term future of the acquired immunodeficiency syndrome (AIDS) epidemic among homosexual men. Data from the Longitudinal AIDS Impact Project in New York City are used to estimate age-specific patterns of unprotected anogenital contact and behavioral change from 1980 to 1991. Model projections are validated using New York City surveillance data on AIDS incidence from 1981 to 1991. The current levels of unsafe sex reported in the Longitudinal AIDS Impact Project are shown to be almost exactly on the epidemic threshold. If this behavior were maintained, HIV prevalence would slowly decline in the population, but with just one additional unsafe sexual partner per year HIV would instead become endemic, with seroprevalence of about 65% in the oldest group and about 25% in the youngest. Transmission dynamics in the youngest group are analyzed in detail. For this group, the assortative age-matching bias in partner selection patterns raises the unsafe behavior threshold slightly in the long run. PMID:8030625

  11. Global approach to simulation: a gateway to long-term human presence in space.

    PubMed

    Collet, J; Novara, M

    1992-01-01

    The establishment of an autonomous European manned space capability is an objective set up by the ESA Council Meeting at the ministerial level, in 1985/1987. ESA's Long-Term Programme Office (LTPO), charged of the preparation of the programme for a European Manned Space Infrastructure (EMSI), started during 1988 to build up an intellectual framework in the domain of long-duration manned space missions. EMSI scope was eventually extended to embrace Moon/Mars missions and bases. Several exploratory studies on problems related to human factors in long-duration space missions were initiated by LTPO. The work of an ad-hoc group of experts (SIMIS Group) has been focused during 1989/1990 on the planning for simulation of such missions with a broad mandate, covering the physiological, psychological and operational aspects of long-duration exposure to microgravity and isolation/confinement. Preliminary results of SIMIS activities are reported. The HYDREMSI experiment, carried out in a terrestrial, analogous environment for 72 days during 1989, is described as an example of the envisaged simulations. PMID:11536971

  12. Long-term storage and safe retrieval of human papillomavirus DNA using FTA elute cards.

    PubMed

    Barth, Heidi; Morel, Adrien; Mougin, Christiane; Averous, Gerlinde; Legrain, Michèle; Fender, Muriel; Risch, Simone; Fafi-Kremer, Samira; Velten, Michel; Oudet, Pierre; Baldauf, Jean-Jacques; Stoll-Keller, Françoise

    2016-03-01

    Biobanking or collection and storage of specimens for future research purposes have become an essential tool in many fields of biomedical research and aims to provide a better understanding of disease mechanisms as well as the identification of disease-specific biomarkers that can navigate in complex diseases. In this study, we assessed the use of Flinders Technology Associates (FTA) cards as a long-term storage device for cervical specimens with suspected human papillomavirus (HPV) infections. HPV detection and genotyping results in liquid-based transport media were compared to HPV results from FTA cards. The overall agreement for the presence of any HPV infection between liquid-based medium and FTA cards stored for 1 year at ambient temperature was 100%. Reproducibility analysis of HPV detection and genotyping from FTA cards demonstrated that FTA cards are a reliable medium to store and preserve viral nucleic acids. Biobanking of cervical cells on FTA cards may provide a key resource for epidemiological and retrospective HPV studies. PMID:26721377

  13. Pain-reducing anesthesia prevents oxidative stress in human term placenta

    PubMed Central

    Tsuzuki, Yoko; Yamashita, Yoriko; Hattori, Yuka; Hua Li, Guang; Akatsuka, Shinya; Kotani, Tomomi; Kikkawa, Fumitaka; Naiki-Ito, Aya; Takahashi, Satoru; Nishiwaki, Kimitoshi; Toyokuni, Shinya

    2016-01-01

    Anesthesia is sometimes used for the reduction of maternal pain in normal human term labor, but whether the drugs affect oxidative stress remains unclear. The placenta serves as an interface between the maternal and fetal vasculature. In this study, we immunohistochemically analyzed two markers for oxidative stress, namely 8-hydroxy-2'-deoxyguanosine (8-OHdG) and 4-hydroxy-2-nonenal–modified proteins (HNE), using placentas from 21 cases of normal tansvaginal delivery (V group), 20 Caesarean sections (C group), and 17 normal transvaginal deliveries with epidural anesthesia (E group). 8-OHdG staining in the nuclei of trophoblasts lining the chorionic villi was significantly stronger in the V group either compared with the C or E group (p<0.001), without significant differences in the C and E groups (p = 0.792). Moderate to intense staining by HNE of the intravascular serum of chorionic villi vasculature was frequently observed in the placentas from the V group, but less frequently of those in either C or E groups (p<0.001), nor the p value comparing the C and E groups was significant (p = 0.128) for HNE staining. Our results suggest that although the role of oxidative stress and its influences on fetal state in the placenta in labor remains unclear, it seems to be lessened by epidural anesthesia. PMID:27013783

  14. TISSUE ENGINEERING PERFUSABLE CANCER MODELS

    PubMed Central

    Fong, E.L.; Santoro, M.; Farach-Carson, M.C.; Kasper, F.K.; Mikos, A.G.

    2014-01-01

    The effect of fluid flow on cancer progression is currently not well understood, highlighting the need for perfused tumor models to close this gap in knowledge. Enabling biological processes at the cellular level to be modeled with high spatiotemporal control, microfluidic tumor models have demonstrated applicability as platforms to study cell-cell interactions, effect of interstitial flow on tumor migration and the role of vascular barrier function. To account for the multi-scale nature of cancer growth and invasion, macroscale models are also necessary. The consideration of fluid dynamics within tumor models at both the micro- and macroscopic levels may greatly improve our ability to more fully mimic the tumor microenvironment. PMID:24634812

  15. Ventilation-perfusion imaging in pulmonary papillomatosis

    SciTech Connect

    Espinola, D.; Rupani, H.; Camargo, E.E.; Wagner, H.N. Jr.

    1981-11-01

    Three children with laryngeal papillomas involving the lungs had serial ventilation-perfusion scintigrams to assess results of therapy designed to reduce the bronchial involvement. Different imaging patterns were observed depending on size, number, and location of lesions. In early parenchymal involvement a ventilation-perfusion mismatch was seen. The initial and follow-up studies correlated well with clinical and radiographic findings. This noninvasive procedure is helpful in evaluating ventilatory and perfusion impairment in these patients as well as their response to treatment.

  16. Cochlear perfusion with a viscous fluid.

    PubMed

    Wang, Yi; Olson, Elizabeth S

    2016-07-01

    The flow of viscous fluid in the cochlea induces shear forces, which could provide benefit in clinical practice, for example to guide cochlear implant insertion or produce static pressure to the cochlear partition or wall. From a research standpoint, studying the effects of a viscous fluid in the cochlea provides data for better understanding cochlear fluid mechanics. However, cochlear perfusion with a viscous fluid may damage the cochlea. In this work we studied the physiological and anatomical effects of perfusing the cochlea with a viscous fluid. Gerbil cochleae were perfused at a rate of 2.4 μL/min with artificial perilymph (AP) and sodium hyaluronate (Healon, HA) in four different concentrations (0.0625%, 0.125%, 0.25%, 0.5%). The different HA concentrations were applied either sequentially in the same cochlea or individually in different cochleae. The perfusion fluid entered from the round window and was withdrawn from basal scala vestibuli, in order to perfuse the entire perilymphatic space. Compound action potentials (CAP) were measured after each perfusion. After perfusion with increasing concentrations of HA in the order of increasing viscosity, the CAP thresholds generally increased. The threshold elevation after AP and 0.0625% HA perfusion was small or almost zero, and the 0.125% HA was a borderline case, while the higher concentrations significantly elevated CAP thresholds. Histology of the cochleae perfused with the 0.0625% HA showed an intact Reissner's membrane (RM), while in cochleae perfused with 0.125% and 0.25% HA RM was torn. Thus, the CAP threshold elevation was likely due to the broken RM, likely caused by the shear stress produced by the flow of the viscous fluid. Our results and analysis indicate that the cochlea can sustain, without a significant CAP threshold shift, up to a 1.5 Pa shear stress. Beside these finding, in the 0.125% and 0.25% HA perfusion cases, a temporary CAP threshold shift was observed, perhaps due to the presence and

  17. Inhomogeneity of pulmonary perfusion during sustained microgravity on SLS-1.

    PubMed

    Prisk, G K; Guy, H J; Elliott, A R; West, J B

    1994-04-01

    We studied the effects of gravity on the inhomogeneity of pulmonary perfusion in humans by performing hyperventilation-breath-hold single-breath measurements before, during, and after 9 days of continuous exposure to microgravity during the Spacelab Life Sciences-1 (SLS-1) mission. In microgravity the indicators of inhomogeneity of perfusion, especially the size of cardiogenic oscillations in expired CO2 and the height of phase IV, were markedly reduced. Cardiogenic oscillations were reduced to approximately 60% of their preflight standing size, and the height of phase IV was between 0 and -8% (a terminal fall became a small terminal rise) of the preflight standing value. The terminal change in expired CO2 was nearly abolished in microgravity, indicating more uniformity of blood flow between lung units that close and those that remain open at the end of expiration. A possible explanation of this observation is the disappearance of gravity-dependent topographic inequality of blood flow. The residual cardiogenic oscillations in expired CO2 imply a persisting inhomogeneity of perfusion in the absence of gravity, probably in lung regions that are not within the same acinus. PMID:8045853

  18. Inhomogeneity of pulmonary perfusion during sustained microgravity on SLS-1

    NASA Technical Reports Server (NTRS)

    Prisk, G. Kim; Guy, Harold J. B.; Elliott, Ann R.; West, John B.

    1994-01-01

    We studied the effects of gravity on the inhomogeneity of pulmonary perfusion in humans by performing hyperventilation-breath-hold single-breath measurements before, during, and after 9 days of continuous exposure to microgravity during the Spacelab Life Sciences-1 (SLS-1) mission. In microgravity the indicators of inhomogeneity of perfusion, especially the size of cardiogenic oscillations in expired CO2 and the height of phase IV, were markedly reduced. Cardiogenic oscillations were reduced to approximately 60% of their preflight standing size, and the height of phase IV was between 0 and -8% (a terminal fall became a small terminal rise) of the preflight standing value. The terminal change in expired CO2 was nearly abolished in microgravity, indicating more uniformity of blood flow between lung units that close and those that remain open at the end of expiration. A possible explanation of this observation is the disappearance of gravity-dependent topographic inequality of blood flow. The residual cardiogenic oscillations in expired CO2 imply a persisting inhomogeneity of perfusion in the absence of gravity, probably in lung regions that are not within the same acinus.

  19. Short-term and long-term effects of protein kinase C on the trafficking and stability of human organic anion transporter 3

    PubMed Central

    Zhang, Qiang; Suh, Wonmo; Pan, Zui; You, Guofeng

    2012-01-01

    Human organic anion transporter 3 (hOAT3) belongs to a family of organic anion transporters that play critical roles in the body disposition of numerous clinically important drugs. Therefore, understanding the regulation of this transporter has profound clinical significance. In the current study, we investigated the short-term and long-term regulation of hOAT3 by protein kinase C (PKC). We showed that short-term activation of PKC by phobol 12-Myristate 13-Acetate (PMA) inhibited hOAT3 activity through accelerating its internalization from cell surface to intracellular recycling endosomes. The colocalization of hOAT3 with EEA1-positive recycling endosomes was demonstrated by immunolocalization with confocal microscopy. Furthermore, we showed that long-term activation of PKC resulted in the enhanced degradation of cell surface hOAT3. The pathways for hOAT3 degradation were further examined using proteasomal and lysosomal inhibitors. Our results showed that both proteasomal inhibitors and the lysosomal inhibitors significantly blocked hOAT3 degradation. These results demonstrate that PKC plays critical roles in the trafficking and the stability of hOAT3. PMID:22773962

  20. Description of an Experiment Investigating Term Relationships as Interpreted by Humans.

    ERIC Educational Resources Information Center

    Rubinoff, Morris; And Others

    An experiment is reported in which 78 subjects examined synonymic and generic-specific relationships among 513 terms compiled from subject indexes of programming textbooks and manuals. Terms were assigned in groups of 20 so that given decisions for terms could be compared for three subjects. The experiment suggested such methodological…

  1. Fetal sex affects expression of renin-angiotensin system components in term human decidua.

    PubMed

    Wang, Yu; Pringle, Kirsty G; Sykes, Shane D; Marques, Francine Z; Morris, Brian J; Zakar, Tamas; Lumbers, Eugenie R

    2012-01-01

    The maternal decidua expresses the genes of the renin-angiotensin system (RAS). Human decidua was collected at term either before labor (i.e. cesarean delivery) or after spontaneous labor. The mRNA for prorenin (REN), prorenin receptor (ATP6AP2), angiotensinogen (AGT), angiotensin-converting enzymes 1 and 2 (ACE1 and ACE2), angiotensin II type 1 receptor (AGTR1), and angiotensin 1-7 receptor (MAS1) were measured by quantitative real-time RT-PCR. Decidual explants were cultured in duplicate for 24 and 48 h, and all RAS mRNA, and the secretion of prorenin, angiotensin II, and angiotensin 1-7 was measured using quantitative real-time RT-PCR, ELISA, and radioimmunoassay, respectively. In the decidua collected before labor, REN mRNA levels were higher if the fetus was female. In addition, REN, ATP6AP2, AGT, and MAS1 mRNA abundance was greater in decidual explants collected from women carrying a female fetus, as was prorenin protein. After 24 h, ACE1 mRNA was higher in the decidual explants from women with a male fetus, whereas after 48 h, both ACE1 and ACE2 mRNA was higher in decidual explants from women with a female fetus. Angiotensin II was present in all explants, but angiotensin 1-7 levels often registered below the lower limits of sensitivity for the assay. After labor, decidua, when compared with nonlaboring decidua, demonstrated lower REN expression when the fetus was female. Therefore, the maternal decidual RAS is regulated in a sex-specific manner, suggesting that it may function differently when the fetus is male than when it is female. PMID:22045662

  2. Processes driving short-term temporal dynamics of small mammal distribution in human-disturbed environments.

    PubMed

    Martineau, Julie; Pothier, David; Fortin, Daniel

    2016-07-01

    As the impact of anthropogenic activities intensifies worldwide, an increasing proportion of landscape is converted to early successional stages every year. To understand and anticipate the global effects of the human footprint on wildlife, assessing short-term changes in animal populations in response to disturbance events is becoming increasingly important. We used isodar habitat selection theory to reveal the consequences of timber harvesting on the ecological processes that control the distribution dynamics of a small mammal, the red-backed vole (Myodes gapperi). The abundance of voles was estimated in pairs of cut and uncut forest stands, prior to logging and up to 2 years afterwards. A week after logging, voles did not display any preference between cut and uncut stands, and a non-significant isodar indicated that their distribution was not driven by density-dependent habitat selection. One month after harvesting, however, juvenile abundance increased in cut stands, whereas the highest proportions of reproductive females were observed in uncut stands. This distribution pattern appears to result from interference competition, with juveniles moving into cuts where there was weaker competition with adults. In fact, the emergence of source-sink dynamics between uncut and cut stands, driven by interference competition, could explain why the abundance of red-backed voles became lower in cut (the sink) than uncut (the source) stands 1-2 years after logging. Our study demonstrates that the influences of density-dependent habitat selection and interference competition in shaping animal distribution can vary frequently, and for several months, following anthropogenic disturbance. PMID:27003700

  3. Luminal distension as a possible consequence of experimental intestinal perfusion

    PubMed Central

    Wingate, David; Hyams, Ashley; Phillips, Sidney

    1974-01-01

    In an experimental jejunal perfusion study, distress in healthy subjects occurred during eight out of 16 perfusions in which intestinal secretion was provoked. Calculation demonstrates the volumetric consequences of inadequate recovery of secretory perfusates, and analysis of the perfusion studies shows that distress was significantly associated with poor recovery of the perfusate. These observations are pertinent to increasing interest in the phenomenon of intestinal fluid secretion. PMID:4435588

  4. Perfusion education and training in Europe.

    PubMed

    Merkle, Frank

    2006-01-01

    Perfusion education and training varies considerably throughout Europe. Unlike in the US, where a common curriculum for perfusion education has been established, each European country has its own education system. This fact is further complicated by a multitude of national languages and cultures. Thus, perfusion education programmes vary, not only in content, but also in their academic levels. This article aims to give a comprehensive overview of the situation in each of the 20 member states of the European Board of Cardiovascular Perfusion (EBCP). The EBCP delegates were polled for a description of the process of training and education of clinical perfusionists in their respective countries. Following the initial delegate poll in 2001, an update of the material was performed in spring 2005. In summary, training of clinical perfusionists in Europe varies considerably between countries. A professional body is necessary to oversee the training process and to guarantee a minimum level of clinical competency for cardiovascular perfusionists. PMID:16485693

  5. Relation of global and regional left ventricular function to tomographic thallium-201 myocardial perfusion in patients with prior myocardial infarction

    SciTech Connect

    Stratton, J.R.; Speck, S.M.; Caldwell, J.H.; Martin, G.V.; Cerqueira, M.; Maynard, C.; Davis, K.B.; Kennedy, J.W.; Ritchie, J.L.

    1988-07-01

    To determine the relation between regional myocardial perfusion and regional wall motion in humans, tomographic thallium-201 imaging and two-dimensional echocardiography at rest were performed on the same day in 83 patients 4 to 12 weeks after myocardial infarction. Myocardial perfusion and wall motion were assessed independently in five left ventricular regions (total 415 regions). Regional myocardial perfusion was quantitated as a percent of the region infarcted (range 0 to 100%) using a previously validated method. Wall motion was graded on a four point scale as 1 = normal (n = 266 regions), 2 = hypokinesia (n = 64), 3 = akinesia (n = 70), 4 = dyskinesia (n = 13) or not evaluable (n = 2). Regional wall motion correlated directly with the severity of the perfusion deficit (r = 0.68, p less than 0.0001). Among normally contracting regions, the mean perfusion defect score was only 2 +/- 4. Increasingly severe wall motion abnormalities were associated with larger perfusion defect scores (hypokinesia = 6 +/- 5, akinesia = 11 +/- 7 and dyskinesia = 18 +/- 5, all p less than 0.01 versus normal. Among regions with normal wall motion, only 3% had a perfusion defect score greater than or equal to 10. Conversely, among 68 regions with a large (greater than or equal to 10) perfusion defect, only 13% had normal motion whereas 87% had abnormal wall motion. The relation between perfusion and wall motion noted for the entire cohort was also present in subgroups of patients with anterior or inferior infarction. In patients with prior myocardial infarction, the severity of the tomographic thallium perfusion defect correlates directly with echocardiographically defined wall motion abnormalities, both globally and regionally.

  6. Myocardial perfusion imaging with 201Tl.

    PubMed

    Pagnanelli, Robert A; Basso, Danny A

    2010-03-01

    The object of this review is to provide information about (201)Tl-thallous chloride in radionuclide myocardial perfusion imaging. This technique has experienced a recent resurgence because of the shortage of (99m)Tc. After reading this article, the technologist will be able to describe the properties and uptake mechanism of (201)Tl, the procedure for myocardial perfusion imaging with this agent, and the advantages and disadvantages of thallium, compared with the technetium agents. PMID:20159930

  7. Improved exercise myocardial perfusion during lidoflazine therapy

    SciTech Connect

    Shapiro, W.; Narahara, K.A.; Park, J.

    1983-11-01

    Lidoflazine is a synthetic drug with calcium-channel blocking effects. In a study of 6 patients with severe classic angina pectoris, single-blind administration of lidoflazine was associated with improved myocardial perfusion during exercise as determined by thallium-201 stress scintigraphy. These studies demonstrate that lidoflazine therapy is associated with relief of angina, an increased physical work capacity, and improved regional myocardial perfusion during exercise.

  8. Perfusion visualization and analysis for pulmonary embolism

    NASA Astrophysics Data System (ADS)

    Vaz, Michael S.; Kiraly, Atilla P.; Naidich, David P.; Novak, Carol L.

    2005-04-01

    Given the nature of pulmonary embolism (PE), timely and accurate diagnosis is critical. Contrast enhanced high-resolution CT images allow physicians to accurately identify segmental and sub-segmental emboli. However, it is also important to assess the effect of such emboli on the blood flow in the lungs. Expanding upon previous research, we propose a method for 3D visualization of lung perfusion. The proposed method allows users to examine perfusion throughout the entire lung volume at a single glance, with areas of diminished perfusion highlighted so that they are visible independent of the viewing location. This may be particularly valuable for better accuracy in assessing the extent of hemodynamic alterations resulting from pulmonary emboli. The method also facilitates user interaction and may help identify small peripheral sub-segmental emboli otherwise overlooked. 19 patients referred for possible PE were evaluated by CT following the administration of IV contrast media. An experienced thoracic radiologist assessed the 19 datasets with 17 diagnosed as being positive for PE with multiple emboli. Since anomalies in lung perfusion due to PE can alter the distribution of parenchymal densities, we analyzed features collected from histograms of the computed perfusion maps and demonstrate their potential usefulness as a preliminary test to suggest the presence of PE. These histogram features also offer the possibility of distinguishing distinct patterns associated with chronic PE and may even be useful for further characterization of changes in perfusion or overall density resulting from associated conditions such as pneumonia or diffuse lung disease.

  9. Application of an acoustofluidic perfusion bioreactor for cartilage tissue engineering

    PubMed Central

    Li, Siwei; Glynne-Jones, Peter; Andriotis, Orestis G.; Ching, Kuan Y.; Jonnalagadda, Umesh S.; Oreffo, Richard O. C.; Hill, Martyn

    2014-01-01

    Cartilage grafts generated using conventional static tissue engineering strategies are characterised by low cell viability, suboptimal hyaline cartilage formation and, critically, inferior mechanical competency, which limit their application for resurfacing articular cartilage defects. To address the limitations of conventional static cartilage bioengineering strategies and generate robust, scaffold-free neocartilage grafts of human articular chondrocytes, the present study utilised custom-built microfluidic perfusion bioreactors with integrated ultrasound standing wave traps. The system employed sweeping acoustic drive frequencies over the range of 890 to 910 kHz and continuous perfusion of the chondrogenic culture medium at a low-shear flow rate to promote the generation of three-dimensional agglomerates of human articular chondrocytes, and enhance cartilage formation by cells of the agglomerates via improved mechanical stimulation and mass transfer rates. Histological examination and assessment of micromechanical properties using indentation-type atomic force microscopy confirmed that the neocartilage grafts were analogous to native hyaline cartilage. Furthermore, in the ex vivo organ culture partial thickness cartilage defect model, implantation of the neocartilage grafts into defects for 16 weeks resulted in the formation of hyaline cartilage-like repair tissue that adhered to the host cartilage and contributed to significant improvements to the tissue architecture within the defects, compared to the empty defects. The study has demonstrated the first successful application of the acoustofluidic perfusion bioreactors to bioengineer scaffold-free neocartilage grafts of human articular chondrocytes that have the potential for subsequent use in second generation autologous chondrocyte implantation procedures for the repair of partial thickness cartilage defects. PMID:25272195

  10. Multiwell cell culture plate format with integrated microfluidic perfusion system

    NASA Astrophysics Data System (ADS)

    Domansky, Karel; Inman, Walker; Serdy, Jim; Griffith, Linda G.

    2006-01-01

    A new cell culture analog has been developed. It is based on the standard multiwell cell culture plate format but it provides perfused three-dimensional cell culture capability. The new capability is achieved by integrating microfluidic valves and pumps into the plate. The system provides a means to conduct high throughput assays for target validation and predictive toxicology in the drug discovery and development process. It can be also used for evaluation of long-term exposure to drugs or environmental agents or as a model to study viral hepatitis, cancer metastasis, and other diseases and pathological conditions.

  11. Hypothermic machine perfusion of the liver and the critical balance between perfusion pressures and endothelial injury.

    PubMed

    't Hart, N A; van der Plaats, A; Leuvenink, H G D; van Goor, H; Wiersema-Buist, J; Verkerke, G J; Rakhorst, G; Ploeg, R J

    2005-01-01

    Hypothermic machine perfusion (HMP) provides better protection against cold ischemic injury than cold storage in marginal donor kidneys. Also, in liver transplantation a switch from static cold storage to HMP could be beneficial as it would allow longer preservation times and the use of marginal donors. A critical question concerning application of HMP in liver preservation is the crucial balance between perfusion pressure and occurrence of endothelial injury. Rat livers were cold-perfused for 24 hours to study perfusion pressures for both hepatic artery and portal vein. Cold storage served as control and was compared to HMP-preserved livers using a mean arterial perfusion pressure of 25 mm Hg and a portal perfusion pressure of 4 mm Hg (25% of normothermic liver circulation) and to HMP at 50 mm Hg and 8 mm Hg perfusion, respectively (50% of normothermic liver circulation). UW solution was enriched with 14.9 micromol/L propidium iodide (PI) to stain for dead cells and with an additional 13.5 micromol/L acridine orange to stain for viable hepatocytes. A low PI-positive cell count was found using HMP at 25% of normal circulation compared to cold storage. The PI count was high for the HMP group perfused at just 50% of normal circulation compared to HMP at 25% and compared to cold storage. In summary, for liver HMP, perfusion at 25% showed complete perfusion with minimal cellular injury. HMP using perfusion pressures of 25 mm Hg for the hepatic artery and 4 mm Hg for the portal vein is feasible without induction of endothelial injury. PMID:15808634

  12. [Pulmonary ventilation/perfusion ratio].

    PubMed

    Guenard, H

    1987-01-01

    The ratios of ventilatory (V) and perfusion (Q) flow rates in the lung are to a large extent responsible for the efficiency of gas exchange. In a simplified monocompartmental model of the lung, the arterial partial pressure of a given gas (Pa) is a function of several factors: the solubility of this gas in blood, its venous and inspired partial pressures and the V/Q ratio. In a multicompartemental model, the mean arterial partial pressure of the gas is a function of the individual values of Pa in each compartment as well as the distribution of V/Q ratios in the lung and the relationship between the concentration and the partial pressure of the gas. The heterogeneity of the distribution of V/Q results from those of both V and Q. Two factors are mainly responsible for this heterogeneity: the gravity and the morphometric characteristics of bronchi and vessels. V/Q ratios are partially controlled at least in low V/Q compartments since hypoxia in these compartments leads to pulmonary arteriolar vasoconstriction. However lungs V/Q ratios range from 0.1 to 10 with a mode around 1. Age, muscular exercise, posture, accelerations, anesthesia, O2 breathing, pulmonary pathology are factors which may alter the distribution of V/Q ratios. PMID:3332289

  13. Temperature control system for water-perfused suits

    NASA Technical Reports Server (NTRS)

    Brengelmann, G. L.; Mckeag, M.; Rowell, L. B.

    1977-01-01

    A system used to control skin temperature in human subjects wearing water-perfused garments is described. It supplies 8 l/min at 10 psi with water temperature controlled within plus or minus 0.1 C. Temperature control is facilitated by a low circulating thermal mass and a fast responding heater based on a commercially available quartz heat lamp. The system is open so that hot or cold water can be added from the building mains to produce rates of change of water temperature exceeding 5 C/min. These capabilities allow semiautomatic control of skin temperature within plus or minus 0.1 C of desired wave forms.

  14. High-throughput analysis of candidate imprinted genes and allele-specific gene expression in the human term placenta

    PubMed Central

    2010-01-01

    Background Imprinted genes show expression from one parental allele only and are important for development and behaviour. This extreme mode of allelic imbalance has been described for approximately 56 human genes. Imprinting status is often disrupted in cancer and dysmorphic syndromes. More subtle variation of gene expression, that is not parent-of-origin specific, termed 'allele-specific gene expression' (ASE) is more common and may give rise to milder phenotypic differences. Using two allele-specific high-throughput technologies alongside bioinformatics predictions, normal term human placenta was screened to find new imprinted genes and to ascertain the extent of ASE in this tissue. Results Twenty-three family trios of placental cDNA, placental genomic DNA (gDNA) and gDNA from both parents were tested for 130 candidate genes with the Sequenom MassArray system. Six genes were found differentially expressed but none imprinted. The Illumina ASE BeadArray platform was then used to test 1536 SNPs in 932 genes. The array was enriched for the human orthologues of 124 mouse candidate genes from bioinformatics predictions and 10 human candidate imprinted genes from EST database mining. After quality control pruning, a total of 261 informative SNPs (214 genes) remained for analysis. Imprinting with maternal expression was demonstrated for the lymphocyte imprinted gene ZNF331 in human placenta. Two potential differentially methylated regions (DMRs) were found in the vicinity of ZNF331. None of the bioinformatically predicted candidates tested showed imprinting except for a skewed allelic expression in a parent-specific manner observed for PHACTR2, a neighbour of the imprinted PLAGL1 gene. ASE was detected for two or more individuals in 39 candidate genes (18%). Conclusions Both Sequenom and Illumina assays were sensitive enough to study imprinting and strong allelic bias. Previous bioinformatics approaches were not predictive of new imprinted genes in the human term

  15. Taste-Mediated Calming in Premature, Preterm, and Full-Term Human Infants.

    ERIC Educational Resources Information Center

    Smith, Barbara A.; Blass, Elliott M.

    1996-01-01

    Preterm and term infants were given a sucrose solution, a glucose solution, or water during a test period in which the amount of their crying was measured. Sucrose reduced crying in preterm and term infants by 91% and 93%, respectively, and glucose by 86% and 81%, respectively. Water was ineffective in reducing crying in both preterm and term…

  16. Diminished Reactivity of Postmature Human Infants to Sucrose Compared with Term Infants.

    ERIC Educational Resources Information Center

    Smith, Barbara A.; And Others

    1992-01-01

    This study of healthy 39-week-old infants, so-called term infants, and chronically stressed 42-week-old infants, so-called postmature infants, showed that sucrose was extremely effective in calming term infants but less effective in calming postmature infants. Results supported the hypothesis that sucrose engages an opioid system in infants. (BG)

  17. Synergy between interleukin-2 and a second factor in the long-term growth of human T cells.

    PubMed Central

    Mills, B J; Shively, J E; Mitsky, P S; Hawke, D H; Forman, S J; Wright, C L; Todd, C W

    1986-01-01

    It has recently been shown that factors in addition to interleukin-2 (IL-2) are required for the proliferation or differentiation of at least some murine T-cell lines. We have previously shown that conditioned medium from human mononuclear cells stimulated with phorbol ester and staphylococcal enterotoxin A is superior to commercial sources of IL-2 for the long-term growth of human T cells. We have identified in these supernatants a non-IL-2 factor (synergistic factor, SF) which synergizes with JURKAT IL-2 in the long-term growth of human T cells. [3H]TdR incorporation by IL-2-dependent human T cells after growth in IL-2 or SF alone for 14 days was slight, but significant. By contrast, growth in a combination of SF and IL-2 for 14 days stimulated [3H]TdR incorporation 10-20-fold higher, generally equal to the high incorporation measured when cells were grown in the presence of the conditioned medium from which SF was obtained. In a standard 2-day IL-2 assay, there was no correlation between activity and long-term growth-promoting ability. These results suggest that the 14-day assay better discerns the growth-promoting activity of various factors or combinations of factors. The mechanism of this interaction between SF and IL-2 remains to be elucidated. It is clear, however, that T-cell growth factor activity, when assessed by the long-term growth of human T cells, is not due to interleukin-2 alone. PMID:3489670

  18. Human Effector / Initiator Gene Sets That Regulate Myometrial Contractility During Term and Preterm Labor

    PubMed Central

    WEINER, Carl P.; MASON, Clifford W.; DONG, Yafeng; BUHIMSCHI, Irina A.; SWAAN, Peter W.; BUHIMSCHI, Catalin S.

    2010-01-01

    Objective Distinct processes govern transition from quiescence to activation during term (TL) and preterm labor (PTL). We sought gene sets responsible for TL and PTL, along with the effector genes necessary for labor independent of gestation and underlying trigger. Methods Expression was analyzed in term and preterm +/− labor (n =6 subjects/group). Gene sets were generated using logic operations. Results 34 genes were similarly expressed in PTL/TL but absent from nonlabor samples (Effector Set). 49 genes were specific to PTL (Preterm Initiator Set) and 174 to TL (Term Initiator Set). The gene ontogeny processes comprising Term Initiator and Effector Sets were diverse, though inflammation was represented in 4 of the top 10; inflammation dominated the Preterm Initiator Set. Comments TL and PTL differ dramatically in initiator profiles. Though inflammation is part of the Term Initiator and the Effector Sets, it is an overwhelming part of PTL associated with intraamniotic inflammation. PMID:20452493

  19. Effects of Steroid Hormones on Sex Differences in Cerebral Perfusion

    PubMed Central

    Ghisleni, Carmen; Bollmann, Steffen; Biason-Lauber, Anna; Poil, Simon-Shlomo; Brandeis, Daniel; Martin, Ernst; Michels, Lars; Hersberger, Martin; Suckling, John

    2015-01-01

    Sex differences in the brain appear to play an important role in the prevalence and progression of various neuropsychiatric disorders, but to date little is known about the cerebral mechanisms underlying these differences. One widely reported finding is that women demonstrate higher cerebral perfusion than men, but the underlying cause of this difference in perfusion is not known. This study investigated the putative role of steroid hormones such as oestradiol, testosterone, and dehydroepiandrosterone sulphate (DHEAS) as underlying factors influencing cerebral perfusion. We acquired arterial spin labelling perfusion images of 36 healthy adult subjects (16 men, 20 women). Analyses on average whole brain perfusion levels included a multiple regression analysis to test for the relative impact of each hormone on the global perfusion. Additionally, voxel-based analyses were performed to investigate the sex difference in regional perfusion as well as the correlations between local perfusion and serum oestradiol, testosterone, and DHEAS concentrations. Our results replicated the known sex difference in perfusion, with women showing significantly higher global and regional perfusion. For the global perfusion, DHEAS was the only significant predictor amongst the steroid hormones, showing a strong negative correlation with cerebral perfusion. The voxel-based analyses revealed modest sex-dependent correlations between local perfusion and testosterone, in addition to a strong modulatory effect of DHEAS in cortical, subcortical, and cerebellar regions. We conclude that DHEAS in particular may play an important role as an underlying factor driving the difference in cerebral perfusion between men and women. PMID:26356576

  20. GPU-accelerated voxelwise hepatic perfusion quantification.

    PubMed

    Wang, H; Cao, Y

    2012-09-01

    Voxelwise quantification of hepatic perfusion parameters from dynamic contrast enhanced (DCE) imaging greatly contributes to assessment of liver function in response to radiation therapy. However, the efficiency of the estimation of hepatic perfusion parameters voxel-by-voxel in the whole liver using a dual-input single-compartment model requires substantial improvement for routine clinical applications. In this paper, we utilize the parallel computation power of a graphics processing unit (GPU) to accelerate the computation, while maintaining the same accuracy as the conventional method. Using compute unified device architecture-GPU, the hepatic perfusion computations over multiple voxels are run across the GPU blocks concurrently but independently. At each voxel, nonlinear least-squares fitting the time series of the liver DCE data to the compartmental model is distributed to multiple threads in a block, and the computations of different time points are performed simultaneously and synchronically. An efficient fast Fourier transform in a block is also developed for the convolution computation in the model. The GPU computations of the voxel-by-voxel hepatic perfusion images are compared with ones by the CPU using the simulated DCE data and the experimental DCE MR images from patients. The computation speed is improved by 30 times using a NVIDIA Tesla C2050 GPU compared to a 2.67 GHz Intel Xeon CPU processor. To obtain liver perfusion maps with 626 400 voxels in a patient's liver, it takes 0.9 min with the GPU-accelerated voxelwise computation, compared to 110 min with the CPU, while both methods result in perfusion parameters differences less than 10(-6). The method will be useful for generating liver perfusion images in clinical settings. PMID:22892645

  1. The plasma cyclic-AMP response to noise in humans and rats—short-term exposure to various noise levels

    NASA Astrophysics Data System (ADS)

    Iwamoto, M.; Dodo, H.; Ishii, F.; Yoneda, J.; Yamazaki, S.; Goto, H.

    1988-12-01

    Rats were exposed to short-term noise which was found to activate the hypothalamohypophyseal-adrenal system and result in a decrease of adrenal ascorbic acid (AAA) and an increase of serum corticosterone (SCS). The threshold limit value lay between 60 and 70 dB(A). To characterize better the effect of noise on the human hypothalamo-hypophyseal-adrenal system, a large group of subjects was exposed to short-term noise at 85 dB(A) and higher, and tested for levels of adrenocortical steroid (cortisol) and anterior pituitary hormones such as ACTH, growth hormone (GH) and prolactin (PRL). Results in humans showed hyperfunction of the hypothalamo-pituitary system. However, as the responses in rats and humans differed, a further experiment was performed using C-AMP, a second messenger mediating many of the effects of a variety of hormones. Plasma C-AMP in humans and rats increased significantly after exposure to noise greater than 70 dB(A). We suggest that plasma C-AMP could be useful as a sensitive index for noise-related stress in the daily living environment of humans and rats.

  2. FATTY ACID CHAIN-ELONGATION IN PERFUSED RAT HEART: SYNTHESIS OF STEAROYLCARNITINE FROM PERFUSED PALMITATE

    PubMed Central

    Kerner, Janos; Minkler, Paul E.; Lesnefsky, Edward J.; Hoppel, Charles L.

    2009-01-01

    Rat hearts perfused for up to 60 min in the working mode with palmitate, but not with glucose, resulted in substantial formation of palmitoylcarnitine and stearoylcarnitine. To test whether lipolysis of endogenous lipids was responsible for the increased stearoylcarnitine content or whether some of the perfused palmitate underwent chain elongation, hearts were perfused with hexadecanoic-16,16,16-d3 acid (M+3). The pentafluorophenacyl ester of deuterium labeled stearoylcarnitine had an M+3 (639.4 m/z) compared to the unlabeled M+0 (636.3 m/z) consistent with a direct chain elongation of the perfused palmitate. Furthermore, the near equal isotope enrichment of palmitoyl- (90.2 ± 5.8 %) and stearoylcarnitine (78.0 ± 7.1 %) suggest that both palmitoyl- and stearoyl-CoA have ready access to mitochondrial carnitine palmitoyltransferase and that most of the stearoylcarnitine is derived from the perfused palmitate. PMID:17761175

  3. Importance of climate, forest fires and human population size on the long-term boreal forest dynamics in Northern Europe

    NASA Astrophysics Data System (ADS)

    Kuosmanen, Niina; Seppä, Heikki; Alenius, Teija; Bradshaw, Richard; Clear, Jennifer; Filimonova, Fludmila; Heikkilä, Maija; Renssen, Hans; Tallavaara, Miikka; Reitalu, Triin

    2016-04-01

    Palaeoecological data provides valuable information for understanding the processes behind the past changes in forest composition, and hence can provide important knowledge regarding the potential effects of future changes in climate on boreal vegetation. Furthermore, it is essential to consider both regional and local factors in order to better understand the processes behind the boreal forest dynamics. The relative importance of climate, forest fires and human population size on long-term boreal forest composition were statistically investigated at regional and local scales in Fennoscandia. Statistical method variation partitioning was employed to assess the relative importance of these three variables. Fossil pollen data reflecting long-term boreal forest composition, at both regional (lake records) and local (small hollow records) scales from Russia, Finland and Sweden, were used as response matrix. Climate, generated from a climate model and oxygen isotope data, past forest fires generated from sedimentary charcoal data and human population size derived from radiocarbon dated archaeological findings were used as potential drivers of long-term boreal vegetation. Though the results clearly demonstrate that climate is the main driver of long-term vegetation changes at the regional scale, the role of climate notably is smaller at local scale and the influence of local site specific factors increases. However, the relative importance of forest fires on long-term changes in boreal forest composition remain generally low both at regional and local scale. The relatively low importance of both climate and forest fires on the variation in long-term boreal forest composition at local scale demonstrates the complexity of factors affecting stand-scale forest dynamics. In general, the relative importance of human population size on long-term changes in boreal vegetation was low. However, this was the first time that this type of human population size data was statistically

  4. Expansion and long-term culture of human spermatogonial stem cells via the activation of SMAD3 and AKT pathways.

    PubMed

    Guo, Ying; Liu, Linhong; Sun, Min; Hai, Yanan; Li, Zheng; He, Zuping

    2015-08-01

    Spermatogonial stem cells (SSCs) can differentiate into spermatids, reflecting that they could be used in reproductive medicine for treating male infertility. SSCs are able to become embryonic stem-like cells with the potentials of differentiating into numerous cell types of the three germ layers and they can transdifferentiate to mature and functional cells of other lineages, highlighting significant applications of human SSCs for treating human diseases. However, human SSCs are very rare and a long-term culture system of human SSCs has not yet established. This aim of study was to isolate, identify and culture human SSCs for a long period. We isolated GPR125-positive spermatogonia with high purity and viability from adult human testicular tissues utilizing the two-step enzymatic digestion and magnetic-activated cell sorting with antibody against GPR125. These freshly isolated cells expressed a number of markers for SSCs, including GPR125, PLZF, GFRA1, RET, THY1, UCHL1 and MAGEA4, but not the hallmarks for spermatocytes and spermatozoa, e.g. SYCP1, SYCP3, PRM1, and TNP1. The isolated human SSCs could be cultured for two months with a significant increase of cell number with the defined medium containing growth factors and hydrogel. Notably, the expression of numerous SSC markers was maintained during the cultivation of human SSCs. Furthermore, SMAD3 and AKT phosphorylation was enhanced during the culture of human SSCs. Collectively, these results suggest that human SSCs can be cultivated for a long period and expanded whilst retaining an undifferentiated status via the activation of SMAD3 and AKT pathways. This study could provide sufficient cells of SSCs for their basic research and clinic applications in reproductive and regenerative medicine. PMID:26088866

  5. The relationship between red blood cell deformability metrics and perfusion of an artificial microvascular network

    PubMed Central

    Sosa, Jose M.; Nielsen, Nathan D.; Vignes, Seth M.; Chen, Tanya G.; Shevkoplyas, Sergey S.

    2013-01-01

    The ability of red blood cells (RBC) to undergo a wide range of deformations while traversing the microvasculature is crucial for adequate perfusion. Interpretation of RBC deformability measurements performed in vitro in the context of microvascular perfusion has been notoriously difficult. This study compares the measurements of RBC deformability performed using micropore filtration and ektacytometry with the RBC ability to perfuse an artificial microvascular network (AMVN). Human RBCs were collected from healthy consenting volunteers, leukoreduced, washed and exposed to graded concentrations (0% – 0.08%) of glutaraldehyde (a non-specific protein cross-linker) and diamide (a spectrin-specific protein cross-linker) to impair the deformability of RBCs. Samples comprising cells with two different levels of deformability were created by adding non-deformable RBCs (hardened by exposure to 0.08% glutaraldehyde) to the sample of normal healthy RBCs. Ektacytometry indicated a nearly linear decline in RBC deformability with increasing glutaraldehyde concentration. Micropore filtration showed a significant reduction only for concentrations of glutaraldehyde higher than 0.04%. Neither micropore filtration nor ektacytometry measurements could accurately predict the AMVN perfusion. Treatment with diamide reduced RBC deformability as indicated by ektacytometry, but had no significant effect on either micropore filtration or the AMVN perfusion. Both micropore filtration and ektacytometry showed a linear decline in effective RBC deformability with increasing fraction of non-deformable RBCs in the sample. The corresponding decline in the AMVN perfusion plateaued above 50%, reflecting the innate ability of blood flow in the microvasculature to bypass occluded capillaries. Our results suggest that in vitro measurements of RBC deformability performed using either micropore filtration or ektacytometry may not represent the ability of same RBCs to perfuse microvascular networks

  6. [Selenium contents in human milk after term and preterm labor and in breast milk substitutes].

    PubMed

    Ladodo, K S; Iatsyk, G V; Oshchenko, A P; Skvortsova, V A; Fam Van Tkhu

    1997-01-01

    Selenium contents in breast milk of Russia's and Vietnam's women after term and preterm childbirth and in breast milk substitutes were studied. The concentration of selenium in breast milk of Russia's women was normal after term and preterm childbirth. The level of selenium in breast milk of Vietnam's women was decreased and could not satisfy completely the need of breasted infants. Selenium contents in babyfood "Malutka" Istra' manufacturing company were lower than those in Sybaj' company. PMID:9206891

  7. Radionuclide cerebral perfusion imaging: Normal pattern

    SciTech Connect

    Goldsmith, S.J.; Stritzke, P.; Losonczy, M.; Vallabhajosula, S.; Holan, V.; DaCosta, M.; Muzinic, M.

    1991-12-31

    Regional cerebral perfusion imaging using a new class of {sup 99m}Tc and {sup 123}I labeled compounds which traverse the blood brain barrier and SPECT imaging technology provides an opportunity to assess this physiologic phenomenon during normal cerebral function and as a manifestation of disease in the central nervous system disease. These applications pose a challenge to the nuclear medicine physician for several reasons: (a) the complex and somewhat unfamiliar functional anatomy, (b) the marked regional differences in regional cerebral perfusion at rest, (c) the lack of understanding of the effect of variations in ambient conditions on regional cerebral perfusion. The difficulties in interpretation are augmented by the display itself. There is frequently no difficulty in differentiating between gray and white matter. However, the frequently used {open_quotes}hot body{close_quotes} color maps, introduce a good deal of contrast, producing displays with apparent interruption in regional cortical perfusion whereas black and white displays provide minimal contrast in the regional cortical activity. The authors sought to define how much variation in regional cerebral perfusion is {open_quotes}allowed{close_quotes} under controlled conditions, to establish a basis to interpret if changes in the environment, psychological interventions, or disease states are accompanied by a measurable change. 2 figs., 1 tab.

  8. Pulmonary perfusion during anesthesia and mechanical ventilation.

    PubMed

    Hedenstierna, G

    2005-06-01

    Cardiac output and the pulmonary perfusion can be affected by anesthesia and by mechanical ventilation. The changes contribute to impeded oxygenation of the blood. The major determinant of perfusion distribution in the lung is the relation between alveolar and pulmonary capillary pressures. Perfusion increases down the lung, due to hydrostatic forces. Since atelectasis is located in dependent lung regions, perfusion of non-ventilated lung parenchyma is common, producing shunt of around 8-10% of cardiac output. In addition, non-gravitational inhomogeneity of perfusion, that can be greater than the gravitational inhomogeneity, adds to impeded oxygenation of blood. Essentially all anaesthetics exert some, although mild, cardiodepressant action with one exception, ketamine. Ketamine may also increase pulmonary artery pressure, whereas other agents have little effect on pulmonary vascular tone. Mechanical ventilation impedes venous return and pushes blood flow downwards to dependent lung regions, and the effect may be striking with higher levels of PEEP. During one-lung anesthesia, there is shunt blood flow both in the non-ventilated and the ventilated lung, and shunt can be much larger in the ventilated lung than thought of. Recruitment manoeuvres shall be directed to the ventilated lung and other physical and pharmacological measures can be taken to manipulate blood flow in one lung anesthesia. PMID:15886595

  9. Quasi-simultaneous multimodal imaging of cutaneous tissue oxygenation and perfusion

    NASA Astrophysics Data System (ADS)

    Ren, Wenqi; Gan, Qi; Wu, Qiang; Zhang, Shiwu; Xu, Ronald

    2015-12-01

    Simultaneous and quantitative assessment of multiple tissue parameters may facilitate more effective diagnosis and therapy in many clinical applications, such as wound healing. However, existing wound assessment methods are typically subjective and qualitative, with the need for sequential data acquisition and coregistration between modalities, and lack of reliable standards for performance evaluation or calibration. To overcome these limitations, we developed a multimodal imaging system for quasi-simultaneous assessment of cutaneous tissue oxygenation and perfusion in a quantitative and noninvasive fashion. The system integrated multispectral and laser speckle imaging technologies into one experimental setup. Tissue oxygenation and perfusion were reconstructed by advanced algorithms. The accuracy and reliability of the imaging system were quantitatively validated in calibration experiments and a tissue-simulating phantom test. The experimental results were compared with a commercial oxygenation and perfusion monitor. Dynamic detection of cutaneous tissue oxygenation and perfusion was also demonstrated in vivo by a postocclusion reactive hyperemia procedure in a human subject and a wound healing process in a wounded mouse model. Our in vivo experiments not only validated the performance of the multimodal imaging system for cutaneous tissue oxygenation and perfusion imaging but also demonstrated its technical potential for wound healing assessment in clinical practice.

  10. Repeatability and reproducibility of optic nerve head perfusion measurements using optical coherence tomography angiography

    NASA Astrophysics Data System (ADS)

    Chen, Chieh-Li; Bojikian, Karine D.; Xin, Chen; Wen, Joanne C.; Gupta, Divakar; Zhang, Qinqin; Mudumbai, Raghu C.; Johnstone, Murray A.; Chen, Philip P.; Wang, Ruikang K.

    2016-06-01

    Optical coherence tomography angiography (OCTA) has increasingly become a clinically useful technique in ophthalmic imaging. We evaluate the repeatability and reproducibility of blood perfusion in the optic nerve head (ONH) measured using optical microangiography (OMAG)-based OCTA. Ten eyes from 10 healthy volunteers are recruited and scanned three times with a 68-kHz Cirrus HD-OCT 5000-based OMAG prototype system (Carl Zeiss Meditec Inc., Dublin, California) centered at the ONH involving two separate visits within six weeks. Vascular images are generated with OMAG processing by detecting the differences in OCT signals between consecutive B-scans acquired at the same retina location. ONH perfusion is quantified as flux, vessel area density, and normalized flux within the ONH for the prelaminar, lamina cribrosa, and the full ONH. Coefficient of variation (CV) and intraclass correlation coefficient (ICC) are used to evaluate intravisit and intervisit repeatability, and interobserver reproducibility. ONH perfusion measurements show high repeatability [CV≤3.7% (intravisit) and ≤5.2% (intervisit)] and interobserver reproducibility (ICC≤0.966) in all three layers by three metrics. OCTA provides a noninvasive method to visualize and quantify ONH perfusion in human eyes with excellent repeatability and reproducibility, which may add additional insight into ONH perfusion in clinical practice.

  11. Eicosanomic profiling reveals dominance of the epoxygenase pathway in human amniotic fluid at term in spontaneous labor

    PubMed Central

    Maddipati, Krishna Rao; Romero, Roberto; Chaiworapongsa, Tinnakorn; Zhou, Sen-Lin; Xu, Zhonghui; Tarca, Adi L.; Kusanovic, Juan Pedro; Munoz, Hernan; Honn, Kenneth V.

    2014-01-01

    Lipid mediators play an important role in reproductive biology, especially, in parturition. Enhanced biosynthesis of eicosanoids, such as prostaglandin E2 (PGE2) and PGF2α, precedes the onset of labor as a result of increased expression of inducible cyclooxygenase 2 (COX-2) in placental tissues. Metabolism of arachidonic acid results in bioactive lipid mediators beyond prostaglandins that could significantly influence myometrial activity. Therefore, an unbiased lipidomic approach was used to profile the arachidonic acid metabolome of amniotic fluid. In this study, liquid chromatography–mass spectrometry was used for the first time to quantitate these metabolites in human amniotic fluid by comparing patients at midtrimester, at term but not in labor, and at term and in spontaneous labor. In addition to exposing novel aspects of COX pathway metabolism, this lipidomic study revealed a dramatic increase in epoxygenase- and lipoxygenase-pathway-derived lipid mediators in spontaneous labor with remarkable product selectivity. Despite their recognition as anti-inflammatory lipid mediators and regulators of ion channels, little is known about the epoxygenase pathway in labor. Epoxygenase pathway metabolites are established regulators of vascular homeostasis in cardiovascular and renal physiology. Their presence as the dominant lipid mediators in spontaneous labor at term portends a yet undiscovered physiological function in parturition.—Maddipati, K. R., Romero, R., Chaiworapongsa, T., Zhou, S.-L., Xu, Z., Tarca, A. L., Kusanovic, J. P., Munoz, H., Honn, K. V. Eicosanomic profiling reveals dominance of the epoxygenase pathway in human amniotic fluid at term in spontaneous labor. PMID:25059230

  12. Longitudinal Study of Cytokine Expression, Lipid Profile and Neuronal Growth Factors in Human Breast Milk from Term and Preterm Deliveries

    PubMed Central

    Collado, Maria Carmen; Santaella, Marina; Mira-Pascual, Laia; Martínez-Arias, Elena; Khodayar-Pardo, Parisá; Ros, Gaspar; Martínez-Costa, Cecilia

    2015-01-01

    Breast milk (BM) is considered as a reference for infant nutrition. The role of bioactive components, such as cytokines, hormones, growth factors (GFs) and fatty acids (FAs) is poorly known, but they might be implicated in immune response development. The aim of this study was to identify the lipid profile and the spectrum of cytokines and neuronal GF in BM samples and analyse the influence of gestational age and lactation time on these components. This study used a longitudinal prospective method for the characterization of cytokines, FAs and GFs global profiles in 120 BM samples from 40 healthy mothers (20 preterm and 20 term) collected as colostrum, transitional and mature milk. The cytokines were analysed by protein array (Ray Bio® Human Cytokine Array G6. Ray Biotech, Inc. Norcross, GA, USA) and the FAs were analysed by gas chromatography. The FA profile was similar between the term and the preterm BM samples. Omega-3-α-linoleic and docosahexaenoic acid (DHA) and omega-6-linoleic acid were the most abundant in the term and preterm samples during lactation. Omega-3 ETA and omega-3 EPA we observed exclusively in the preterm samples. The cytokine profile showed a different trend based on gestational age. A significantly higher expression of neurotrophic factors was found in the mature preterm milk samples as compared to the mature term samples. Our study is the first to identify the influence and interactions of perinatal factors on cytokine, GFs and FAs in human milk. PMID:26492267

  13. Longitudinal Study of Cytokine Expression, Lipid Profile and Neuronal Growth Factors in Human Breast Milk from Term and Preterm Deliveries.

    PubMed

    Collado, Maria Carmen; Santaella, Marina; Mira-Pascual, Laia; Martínez-Arias, Elena; Khodayar-Pardo, Parisá; Ros, Gaspar; Martínez-Costa, Cecilia

    2015-10-01

    Breast milk (BM) is considered as a reference for infant nutrition. The role of bioactive components, such as cytokines, hormones, growth factors (GFs) and fatty acids (FAs) is poorly known, but they might be implicated in immune response development. The aim of this study was to identify the lipid profile and the spectrum of cytokines and neuronal GF in BM samples and analyse the influence of gestational age and lactation time on these components. This study used a longitudinal prospective method for the characterization of cytokines, FAs and GFs global profiles in 120 BM samples from 40 healthy mothers (20 preterm and 20 term) collected as colostrum, transitional and mature milk. The cytokines were analysed by protein array (Ray Bio® Human Cytokine Array G6. Ray Biotech, Inc. Norcross, GA, USA) and the FAs were analysed by gas chromatography. The FA profile was similar between the term and the preterm BM samples. Omega-3-α-linoleic and docosahexaenoic acid (DHA) and omega-6-linoleic acid were the most abundant in the term and preterm samples during lactation. Omega-3 ETA and omega-3 EPA we observed exclusively in the preterm samples. The cytokine profile showed a different trend based on gestational age. A significantly higher expression of neurotrophic factors was found in the mature preterm milk samples as compared to the mature term samples. Our study is the first to identify the influence and interactions of perinatal factors on cytokine, GFs and FAs in human milk. PMID:26492267

  14. A proposed lexicon of terms and concepts for human-bear management in North America

    USGS Publications Warehouse

    Hopkins, John B., III; Herrero, Stephen; Shideler, Richard T.; Gunther, Kerry A.; Schwartz, Charles C.; Kalinowski, Steven T.

    2010-01-01

    We believe that communication within and among agency personnel in the United States and Canada about the successes and failures of their human–bear (Ursidae) management programs will increase the effectiveness of these programs and of bear research. To communicate more effectively, we suggest agencies clearly define terms and concepts used in human–bear management and use them in a consistent manner. We constructed a human–bear management lexicon of terms and concepts using a modified Delphi method to provide a resource that facilitates more effective communication among human–bear management agencies. Specifically, we defined 40 terms and concepts in human–bear management and suggest definitions based on discussions with 13 other professionals from the United States and Canada. Although new terms and concepts will emerge in the future and definitions will evolve as we learn more about bear behavior and ecology, our purpose is to suggest working definitions for terms and concepts to help guide human–bear management and research activities in North America. Applications or revisions of these definitions may be useful outside of North America.

  15. Cerebral abnormalities in cocaine abusers: Demonstration by SPECT perfusion brain scintigraphy. Work in progress

    SciTech Connect

    Tumeh, S.S.; Nagel, J.S.; English, R.J.; Moore, M.; Holman, B.L. )

    1990-09-01

    Single photon emission computed tomography (SPECT) perfusion brain scans with iodine-123 isopropyl iodoamphetamine (IMP) were obtained in 12 subjects who acknowledged using cocaine on a sporadic to a daily basis. The route of cocaine administration varied from nasal to intravenous. Concurrent abuse of other drugs was also reported. None of the patients were positive for human immunodeficiency virus. Brain scans demonstrated focal defects in 11 subjects, including seven who were asymptomatic, and no abnormality in one. Among the findings were scattered focal cortical deficits, which were seen in several patients and which ranged in severity from small and few to multiple and large, with a special predilection for the frontal and temporal lobes. No perfusion deficits were seen on I-123 SPECT images in five healthy volunteers. Focal alterations in cerebral perfusion are seen commonly in asymptomatic drug users, and these focal deficits are readily depicted by I-123 IMP SPECT.

  16. Dependence of Brain Intravoxel Incoherent Motion Perfusion Parameters on the Cardiac Cycle

    PubMed Central

    Federau, Christian; Hagmann, Patric; Maeder, Philippe; Müller, Markus; Meuli, Reto; Stuber, Matthias; O’Brien, Kieran

    2013-01-01

    Measurement of microvascular perfusion with Intravoxel Incoherent Motion (IVIM) MRI is gaining interest. Yet, the physiological influences on the IVIM perfusion parameters (“pseudo-diffusion” coefficient D*, perfusion fraction f, and flow related parameter fD*) remain insufficiently characterized. In this article, we hypothesize that D* and fD*, which depend on blood speed, should vary during the cardiac cycle. We extended the IVIM model to include time dependence of D* = D*(t), and demonstrate in the healthy human brain that both parameters D* and fD* are significantly larger during systole than diastole, while the diffusion coefficient D and f do not vary significantly. The results non-invasively demonstrate the pulsatility of the brain’s microvasculature. PMID:24023649

  17. Impact of human milk pasteurization on the kinetics of peptide release during in vitro dynamic term newborn digestion.

    PubMed

    Deglaire, Amélie; De Oliveira, Samira C; Jardin, Julien; Briard-Bion, Valérie; Emily, Mathieu; Ménard, Olivia; Bourlieu, Claire; Dupont, Didier

    2016-07-01

    Holder pasteurization (62.5°C, 30 min) ensures sanitary quality of donor's human milk but also denatures beneficial proteins. Understanding whether this further impacts the kinetics of peptide release during gastrointestinal digestion of human milk was the aim of the present paper. Mature raw (RHM) or pasteurized (PHM) human milk were digested (RHM, n = 2; PHM, n = 3) by an in vitro dynamic system (term stage). Label-free quantitative peptidomics was performed on milk and digesta (ten time points). Ascending hierarchical clustering was conducted on "Pasteurization × Digestion time" interaction coefficients. Preproteolysis occurred in human milk (159 unique peptides; RHM: 91, PHM: 151), mostly on β-casein (88% of the endogenous peptides). The predicted cleavage number increased with pasteurization, potentially through plasmin activation (plasmin cleavages: RHM, 53; PHM, 76). During digestion, eight clusters resumed 1054 peptides from RHM and PHM, originating for 49% of them from β-casein. For seven clusters (57% of peptides), the kinetics of peptide release differed between RHM and PHM. The parent protein was significantly linked to the clustering (p-value = 1.4 E-09), with β-casein and lactoferrin associated to clusters in an opposite manner. Pasteurization impacted selectively gastric and intestinal kinetics of peptide release in term newborns, which may have further nutritional consequences. PMID:26990007

  18. Transfer of PAMAM Dendrimers across Human Placenta: Prospects of Its Use as Drug Carrier During Pregnancy

    PubMed Central

    Menjoge, Anupa R.; Rinderknecht, Amber; Navath, Raghavendra S.; Faridnia, Masoud; Kim, Chong J.; Romero, Roberto; Miller, Richard K.; Kannan, Rangaramanujam M.

    2011-01-01

    Dendrimers offer significant potential as nanocarriers for targeted delivery of drugs and imaging agents. The objectives of this study were to evaluate the transplacental transport, kinetics and biodistribution of PAMAM dendrimers ex-vivo across the human placenta in comparison with antipyrine, a freely diffusible molecule, using dually perfused re-circulating term human placental lobules. The purpose of this study is to determine if dendrimers as drug carriers can be used to design drug delivery systems directed at selectively treating either the mother or the fetus. The transplacental transfers of fluorescently (Alexa 488) tagged PAMAM dendrimer (16 kDa) and antipyrine (188 Da) from maternal to fetal circulation were measured using HPLC/dual UV and fluorescent detector (sensitivity of 10 ng / mL for dendrimer and 100 ng /mL for antipyrine respectively). Cmax for the dendrimer-Alexa (DA) in maternal perfusate (Tmax = 15min) was 18 times higher than in the fetal perfusate and never equilibrated with the maternal perfusate during 5.5 hours of perfusion (n=4). DA exhibited a significant but low transplacental transport of ~2.26 ± 0.12 μg / mL during 5.5 hours, where the mean transplacental transfer was 0.84 ±0.11 % of the total maternal concentration and the feto-maternal ratio as percent was 0.073% ± 0.02. The biochemical and physiological analysis of the placentae perfused with DA demonstrated normal function throughout the perfusion. The immunofluorescence histochemistry confirmed that the biodistribution of DA in perfused placenta was sparsely dispersed, and when noted was principally seen in the inter-villous spaces and outer rim of the villous branches. In a few cases, DA was found internalized and localized in nuclei and cytoplasm of syncytiotrophoblast and inside the villous core; however, DA was mostly absent from the villous capillaries. In conclusion, the PAMAM dendrimers exhibited a low rate of transfer from maternal to the fetal side across the

  19. Possible psycho-physiological consequences of human long-term space missions

    NASA Astrophysics Data System (ADS)

    Belisheva, N. K.; Lammer, H.; Biernat, H. K.; Kachanova, T. L.; Kalashnikova, I. V.

    Experiments carried out on the Earth s surface during different years and under contrast periods of solar activity have shown that the functional state of biosystems including the human organisms are controlled by global and local geocosmical agents Our finding have a close relation to space research because they demonstrate the reactions of biosystems on variations of global and local geocosmical agents and the mechanisms of modulations of biosystems state by geocosmical agents We revealed the role of variations of the geomagnetic field for the stimulation of immune systems functional state of peripheral blood human brain growth of microflora skin covers and pathogenic microorganisms The study of the psycho-physiological state of the human organism has demonstrated that an increase of the neutron intensity near the Earth s surface is associated with anxiety decrease of normal and increase of paradox reactions of examinees The analysis of the human brain functional state in dependent on the geomagnetic variation structure dose under exposure to the variations of geomagnetic field in a certain amplitude-frequency range and also the intensity of the nucleon component of secondary cosmic rays showed that the stable and unstable states of the human brain are determined by geomagnetic field variations and the intensity of the nucleon component The stable state of the brain manifested under the periodic oscillations of the geomagnetic field in a certain amplitude-frequency range The low level of geomagnetic activity associated with an

  20. Long-term methamphetamine administration in the vervet monkey models aspects of a human exposure: brain neurotoxicity and behavioral profiles.

    PubMed

    Melega, William P; Jorgensen, Matthew J; Laćan, Goran; Way, Baldwin M; Pham, Jamie; Morton, Grenvill; Cho, Arthur K; Fairbanks, Lynn A

    2008-05-01

    Methamphetamine (METH)-associated alterations in the human striatal dopamine (DA) system have been identified with positron emission tomography (PET) imaging and post-mortem studies but have not been well correlated with behavioral changes or cumulative METH intake. Animal studies that model some aspects of human long-term METH abuse can establish dose-dependency profiles of both behavioral changes and potential brain neurotoxicities for identifying consequences of particular cumulative exposures. Based on parameters from human and our monkey pharmacokinetic studies, we modeled a prevalent human METH exposure of daily multiple doses in socially housed vervet monkeys. METH doses were escalated over 33 weeks, with final dosages resulting in estimated peak plasma METH concentrations of 1-3 microM, a range measured in human abusers. With larger METH doses, progressive increases in abnormal behavior and decreases in social behavior were observed on 'injection' days. Anxiety increased on 'no injection' days while aggression decreased throughout the study. Thereafter, during 3 weeks abstinence, differences in baseline vs post-METH behaviors were not observed. Post-mortem analysis of METH brains showed 20% lower striatal DA content while autoradiography studies of precommissural striatum showed 35% lower [3H]WIN35428 binding to the DA transporter. No statistically significant changes were detected for [3H]dihydrotetrabenazine binding to the vesicular monoamine transporter (METH-lower by 10%) or for [3H]SCH 23390 and [3H]raclopride binding to DA D1 and D2 receptors, respectively. Collectively, this long-term, escalating dose METH exposure modeling a human abuse pattern, not associated with high-dose binges, resulted in dose-dependent behavioral effects and caused persistent changes in presynaptic striatal DA system integrity. PMID:17625500

  1. Perfusion and ventilation of isolated canine lungs

    PubMed Central

    Otto, T. J.; Trenkner, M.; Stopczyk, A.; Gawdziński, M.; Chełstowska, B.

    1968-01-01

    In order to evaluate methods of preserving lungs for use in transplantation, experiments on 28 mongrel dogs were carried out. Two methods were tried—first, mechanical respiration of isolated lungs under deep hypothermia, with the vascular bed filled with blood; and, secondly, the perfusion of isolated lungs with the aid of a modified DeWall's apparatus. Allogenic transplantations of lungs preserved in both ways were carried out. Gasometric and histological examinations of preserved lungs, before and after transplantation, were performed. The best results were obtained with perfusion under hypothermic conditions; ventilation without perfusion resulted in failure. Lung transplantation was successful when, after being preserved, the lung remained unchanged. Major discrepancies between the macroscopic and microscopic findings in preserved lungs were observed. An original classification of the changes occurring in preserved lungs is proposed. PMID:4886091

  2. Perfusion in Britain: the early days.

    PubMed

    Braimbridge, Mark V

    2004-07-01

    Experimental perfusion was largely the province of Germany in the nineteenth century but in the mid-twentieth century the focus of perfusion switched to the USA with the explosive clinical advances of Lillehei, Kirklin and Cooley. British clinical perfusion started with Melrose in 1953 at the Postgraduate Medical School in London but, as in other centres at that time, stopped due to the high mortality. The arrival of hands-on experience of American expertise via returning research fellows and other visitors to the USA enabled the first successful on-going series to begin at the Hammersmith Hospital with Cleland in 1957 and then to spread around the country. The various problems of those early 1950s days are described in the units starting then. PMID:15376765

  3. Myocardial perfusion scintigraphy: the evidence.

    PubMed

    Underwood, S R; Anagnostopoulos, C; Cerqueira, M; Ell, P J; Flint, E J; Harbinson, M; Kelion, A D; Al-Mohammad, A; Prvulovich, E M; Shaw, L J; Tweddel, A C

    2004-02-01

    This review summarises the evidence for the role of myocardial perfusion scintigraphy (MPS) in patients with known or suspected coronary artery disease. It is the product of a consensus conference organised by the British Cardiac Society, the British Nuclear Cardiology Society and the British Nuclear Medicine Society and is endorsed by the Royal College of Physicians of London and the Royal College of Radiologists. It was used to inform the UK National Institute of Clinical Excellence in their appraisal of MPS in patients with chest pain and myocardial infarction. MPS is a well-established, non-invasive imaging technique with a large body of evidence to support its effectiveness in the diagnosis and management of angina and myocardial infarction. It is more accurate than the exercise ECG in detecting myocardial ischaemia and it is the single most powerful technique for predicting future coronary events. The high diagnostic accuracy of MPS allows reliable risk stratification and guides the selection of patients for further interventions, such as revascularisation. This in turn allows more appropriate utilisation of resources, with the potential for both improved clinical outcomes and greater cost-effectiveness. Evidence from modelling and observational studies supports the enhanced cost-effectiveness associated with MPS use. In patients presenting with stable or acute chest pain, strategies of investigation involving MPS are more cost-effective than those not using the technique. MPS also has particular advantages over alternative techniques in the management of a number of patient subgroups, including women, the elderly and those with diabetes, and its use will have a favourable impact on cost-effectiveness in these groups. MPS is already an integral part of many clinical guidelines for the investigation and management of angina and myocardial infarction. However, the technique is underutilised in the UK, as judged by the inappropriately long waiting times and by

  4. Wnt Signaling Orchestration with a Small Molecule DYRK Inhibitor Provides Long-Term Xeno-Free Human Pluripotent Cell Expansion

    PubMed Central

    Hasegawa, Kouichi; Yasuda, Shin-ya; Teo, Jia-Ling; Nguyen, Cu; McMillan, Michael; Hsieh, Chih-Lin; Suemori, Hirofumi; Nakatsuji, Norio; Yamamoto, Masashi; Miyabayashi, Tomoyuki; Lutzko, Carolyn; Pera, Martin F.

    2012-01-01

    An optimal culture system for human pluripotent stem cells should be fully defined and free of animal components. To date, most xeno-free culture systems require human feeder cells and/or highly complicated culture media that contain activators of the fibroblast growth factor (FGF) and transforming growth factor-β (TGFβ) signaling pathways, and none provide for replacement of FGF/TGFβ ligands with chemical compounds. The Wnt/β-catenin signaling pathway plays an important role in mouse embryonic stem cells in leukemia inhibitory factor-independent culture; however, the role of Wnt/β-catenin signaling in human pluripotent stem cell is still poorly understood and controversial because of the dual role of Wnts in proliferation and differentiation. Building on our previous investigations of small molecules modulating Wnt/β-catenin signaling in mouse embryonic stem cells, we identified a compound, ID-8, that could support Wnt-induced human embryonic stem cell proliferation and survival without differentiation. Dual-specificity tyrosine phosphorylation-regulated kinase (DYRK) is the target of the small molecule ID-8. Its role in human pluripotent cell renewal was confirmed by DYRK knockdown in human embryonic stem cells. Using Wnt and the DYRK inhibitor ID-8, we have developed a novel and simple chemically defined xeno-free culture system that allows for long-term expansion of human pluripotent stem cells without FGF or TGFβ activation. These culture conditions do not include xenobiotic supplements, serum, serum replacement, or albumin. Using this culture system, we have shown that several human pluripotent cell lines maintained pluripotency (>20 passages) and a normal karyotype and still retained the ability to differentiate into derivatives of all three germ layers. This Wnt-dependent culture system should provide a platform for complete replacement of growth factors with chemical compounds. PMID:23197636

  5. A Neurocognitive Model for Short-Term Sensory and Motor Preparatory Activity in Humans

    ERIC Educational Resources Information Center

    Gomez, Carlos M.; Vaquero, Encarna; Vazquez-Marrufo, Manuel

    2004-01-01

    The purpose of this review is to present information from different experiments that supports the proposal that brain systems are able to predict, in a short-term interval, certain characteristics about the next incoming stimuli. This ability allows the subject to be ready for the stimuli and be more efficient in completing the required task.…

  6. The hippocampus is required for short-term topographical memory in humans

    PubMed Central

    Hartley, Tom; Bird, Chris M.; Chan, Dennis; Cipolotti, Lisa; Husain, Masud; Vargha-Khadem, Faraneh; Burgess, Neil

    2009-01-01

    The hippocampus plays a crucial role within the neural systems for long-term memory, but little if any role in the short-term retention of some types of stimuli. Nonetheless, the hippocampus may be specialized for allocentric topographical processing which impacts on short-term memory or even perception. To investigate this we developed performance-matched tests of perception (match-to-sample) and short-term memory (2s delayed-match-to-sample) for the topography and for the non-spatial aspects of visual scenes. Four patients with focal hippocampal damage and one with more extensive damage, including right parahippocampal gyrus, were tested. All five patients showed impaired topographical memory and spared non-spatial processing in both memory and perception. Topographical perception was profoundly impaired in the patient with parahippocampal damage, mildly impaired in two of the hippocampal cases and clearly preserved in the other two hippocampal cases (including one with dense amnesia). Our results suggest that the hippocampus supports allocentric topographical processing that is indispensable when appropriately tested after even very short delays, while the presence of the sample scene can allow successful topographical perception without it, possibly via a less flexible parahippocampal representation. PMID:17143905

  7. Long-term fatty acid stability in human serum cholesteryl ester, triglyceride, and phospholipid fractions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fatty acid profiles of biological specimens from epidemiological/clinical studies can serve as biomarkers to assess potential relationships between diet and chronic disease risk. However, data are limited regarding fatty acid stability of archived specimens following long-term storage, a variable t...

  8. Behavioral Specifications of Reward-Associated Long-Term Memory Enhancement in Humans

    ERIC Educational Resources Information Center

    Wittmann, Bianca C.; Dolan, Raymond J.; Duzel, Emrah

    2011-01-01

    Recent functional imaging studies link reward-related activation of the midbrain substantia nigra-ventral tegmental area (SN/VTA), the site of origin of ascending dopaminergic projections, with improved long-term episodic memory. Here, we investigated in two behavioral experiments how (1) the contingency between item properties and reward, (2) the…

  9. Leukocyte Populations in Human Preterm and Term Breast Milk Identified by Multicolour Flow Cytometry

    PubMed Central

    Trend, Stephanie; de Jong, Emma; Lloyd, Megan L.; Kok, Chooi Heen; Richmond, Peter; Doherty, Dorota A.; Simmer, Karen; Kakulas, Foteini; Strunk, Tobias; Currie, Andrew

    2015-01-01

    Background Extremely preterm infants are highly susceptible to bacterial infections but breast milk provides some protection. It is unknown if leukocyte numbers and subsets in milk differ between term and preterm breast milk. This study serially characterised leukocyte populations in breast milk of mothers of preterm and term infants using multicolour flow cytometry methods for extended differential leukocyte counts in blood. Methods Sixty mothers of extremely preterm (<28 weeks gestational age), very preterm (28–31 wk), and moderately preterm (32–36 wk), as well as term (37–41 wk) infants were recruited. Colostrum (d2–5), transitional (d8–12) and mature milk (d26–30) samples were collected, cells isolated, and leukocyte subsets analysed using flow cytometry. Results The major CD45+ leukocyte populations circulating in blood were also detectable in breast milk but at different frequencies. Progression of lactation was associated with decreasing CD45+ leukocyte concentration, as well as increases in the relative frequencies of neutrophils and immature granulocytes, and decreases in the relative frequencies of eosinophils, myeloid and B cell precursors, and CD16- monocytes. No differences were observed between preterm and term breast milk in leukocyte concentration, though minor differences between preterm groups in some leukocyte frequencies were observed. Conclusions Flow cytometry is a useful tool to identify and quantify leukocyte subsets in breast milk. The stage of lactation is associated with major changes in milk leukocyte composition in this population. Fresh preterm breast milk is not deficient in leukocytes, but shorter gestation may be associated with minor differences in leukocyte subset frequencies in preterm compared to term breast milk. PMID:26288195

  10. A comparative biomechanical analysis of term fetal membranes in human and domestic species

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The purpose of this study was to biomechanically characterize and compare human, porcine, equine, and ovine fetal membranes. Noncontact metrology was used for topographic analyses. Uniaxial tensile testing was performed to resolve specific biomechanical values. Puncture force and radial stresses we...

  11. Reactive nitrogen and human health: acute and long-term implications.

    PubMed

    Wolfe, Amir H; Patz, Jonathan A

    2002-03-01

    Reactive-nitrogen (Nr) has a wide variety of beneficial and detrimental effects on human health. The most important of the beneficial effects are increasing global and regional food supplies and increased nutritional quality of available foods. However, lack of adequate dietary intake of amino acids and proteins is a serious cause of malnutrition when food supplies are inadequate because of poverty, drought, floods, wars, and displacements of people as refugees. There is sufficient, though limited, quantitative data indicating that increased circulation of Nr in the environment is responsible for significant human health effects via other exposure pathways. Nr can lead to harmful health effects from airborne occupational exposures and population-wide indoor and outdoor air pollution exposures to nitrogen dioxide and ozone. Nr can also affect health via water pollution problems, including methemoglobinemia from contaminated ground water, eutrophication causing fish kills and algal blooms that can be toxic to humans, and via global warming. The environmental pollutants stemming from reactive nitrogen are ubiquitous, making it difficult to identify the extent to which Nr exerts a specific health effect. As all populations are susceptible, continued interdisciplinary investigations are needed to determine the extent and nature of the beneficial and harmful effects on human health of nitrogen-related pollutants and their derivatives. PMID:12078000

  12. Interleukin-8 and Its Receptors in Human Milk from Mothers of Full-Term and Premature Infants.

    PubMed

    Polat, Adem; Tunc, Turan; Erdem, Galip; Yerebasmaz, Neslihan; Tas, Ahmet; Beken, Serdar; Basbozkurt, Gokalp; Saldir, Mehmet; Zenciroglu, Aysegul; Yaman, Halil

    2016-06-01

    In addition to its nutritional benefits, human milk also has bioactive elements. Limited immunological functions of newborns are supported and altered by the immunological elements of mother milk. Chemokines are of importance among these immune factors. Interleukin-8 (IL-8) has been demonstrated in mother's milk, and its receptors, CXC chemokine receptors (CXCR)-1 and CXCR-2, were detected on cells, responsible for immunological reactions and mammary glandular cells. The soluble forms of these receptors are yet to be described in human milk. In this study, it was aimed to assess the IL-8 levels and the concentrations of its receptors in colostrum and mature mother's milk in regard to preterm and term delivery. The results of this study indicated a decline in IL-8 levels with the lactation stage, but no difference was observed between term and preterm mother's milk. Regarding the CXCR-1 and CXCR-2, the concentrations of these receptors were similar in both colostrum and mature milk. Furthermore, there was not any significant difference between term and preterm mother's milk. In conclusion, this is the first study to investigate the concentrations of CXCR-1 and CXCR-2 with the levels of IL-8 in colostrum and mature human milk of term and preterm newborns. The alterations in IL-8 levels were similar in some of the studies reported. CXCR-1 and CXCR-2 levels did not demonstrate any significant difference. Further studies are required to investigate the soluble forms of these receptors and their relation to IL-8 with larger cohort. PMID:27105439

  13. Cadmium transport and toxicity in isolated perfused renal proximal tubules

    SciTech Connect

    Robinson, M.E.K.

    1991-01-01

    Cadmium is a potent toxicant preferentially accumulated in the renal cortex of humans and other animals. To assess the renal toxicity of inorganic cadmium, isolated segments (S1, S2, and S3) of rabbit renal proximal tubules were perfused with various concentrations of unlabeled cadmium chloride (CdCl[sub 2]) and a vital dye (FD C green). The tubular epithelial cells were observed under the light microscope for cellular injury and necrosis. Cellular swelling, luminal membrane blebbing, and cellular vacuolization were indicators of cellular injury, and dye uptake was indicative of cellular necrosis. To determine lumen-to-bath transport rates for cadmium, the segments were perfused with a mixture of [sup 109]CdCl[sub 2] and [sup 3]H-L-glucose; unlabeled CdCl[sub 2] was added when necessary to vary the total cadmium concentration from 1.5 [mu]M to 2000 [mu]M. Immediately after perfusion the tubules were extracted with 3% trichoroacetic acid (TCA) or with a modified Ringer's buffer of reduced osmolality to determine the fate of the cadmium removed from the lumen. Based on the toxicant indicators, increased dye uptake, increased luminal membrane blebbing, and increased vacuole formation, as the cadmium concentration was increased, cadmium was found to show toxicity to renal tubular cells at concentrations greater than 500 [mu]M. In transport experiments, increasing the cadmium concentration causes an increase in the leak of L-glucose, also indicating toxicity. A clear imbalance exists between the rate of disappearance of cadmium from the lumen and the rate of appearance in the bath for all three tubular segments. Cadmium appears to bind cellular membrane proteins, but it is extractable with 3% TCA. Cadmium, like mercury, is taken up at the luminal membrane, but very little is transported through the basolateral membrane.

  14. Uterine perfusion model for analyzing barriers to transport in fibroids.

    PubMed

    Stirland, Darren L; Nichols, Joseph W; Jarboe, Elke; Adelman, Marisa; Dassel, Mark; Janát-Amsbury, Margit-Maria; Bae, You Han

    2015-09-28

    This project uses an ex vivo human perfusion model for studying transport in benign, fibrous tumors. The uterine arteries were cannulated to perfuse the organ with a buffer solution containing blood vessel stain and methylene blue to analyze intratumoral transport. Gross examination revealed tissue expansion effects and a visual lack of methylene blue in the fibroids. Some fibroids exhibited regions with partial methylene blue penetration into the tumor environment. Histological analysis comparing representative sections of fibroids and normal myometrium showed a smaller number of vessels with decreased diameters within the fibroid. Imaging of fluorescently stained vessels exposed a stark contrast between fluorescence within the myometrium and relatively little within the fibroid tissues. Imaging at higher magnification revealed that fibroid blood vessels were indeed perfused and stained with the lipophilic membrane dye; however, the vessels were only the size of small capillaries and the blood vessel coverage was only 12% that of the normal myometrium. The majority of sampled fibroids had a strong negative correlation (Pearson's r=-0.68 or beyond) between collagen and methylene blue staining. As methylene blue was able to passively diffuse into fibroid tissue, the true barrier to transport in these fibroids is likely high interstitial fluid pressure, correlating with high collagen content and solid stress observed in the fibroid tissue. Fibroids had an average elevated interstitial fluid pressure of 4mmHg compared to -1mmHg in normal myometrium. Our findings signify relationships between drug distribution in fibroids and between vasculature characteristics, collagen levels, and interstitial fluid pressure. Understanding these barriers to transport can lead to developments in drug delivery for the treatment of uterine fibroids and tumors of similar composition. PMID:26184049

  15. Effects of laser acupuncture on blood perfusion rate

    NASA Astrophysics Data System (ADS)

    Wang, Xian-ju; Zeng, Chang-chun; Liu, Han-ping; Liu, Song-hao; Liu, Liang-gang

    2006-09-01

    Based on Pennes equation, the influences of the intensity and the impulse frequency of laser acupuncture on the point tissues' blood flow perfusion rate are discussed. We find that the blood perfusion rate of point tissue increases with the intensity of laser acupuncture increasing. After impulse laser acupuncture the point tissue blood perfusion rate increase little, but after continuum laser acupuncture the point tissues blood perfusion rate increase much.

  16. Accumulation of apoptosis-insensitive human bone marrow-mesenchymal stromal cells after long-term expansion.

    PubMed

    Jeong, Sin-Gu; Cho, Goang-Won

    2016-07-01

    Cells undergo replicative senescence during in vitro expansion, which is induced by the accumulation of cellular damage caused by excessive reactive oxygen species. In this study, we investigated whether long-term-cultured human bone marrow mesenchymal stromal cells (MSCs) are insensitive to apoptotic stimulation. To examine this, we established replicative senescent cells from long-term cultures of human bone marrow MSCs. Senescent cells were identified based on declining population doublings, increased expression of senescence markers p16 and p53 and increased senescence-associated β-gal activity. In cell viability assays, replicative senescent MSCs in late passages (i.e. 15-19 passages) resisted damage induced by oxidative stress more than those in early passages did (i.e. 7-10 passages). This resistance occurred via caspase-9 and caspase-3 rather than via caspase-8. The senescent cells are gradually accumulated during long-term expansion. The oxidative stress-sensitive proteins ataxia-telangiectasia mutated and p53 were phosphorylated, and the expression of apoptosis molecules Bax increased, and Bcl-2 decreased in early passage MSCs; however, the expression of the apoptotic molecules did less change in response to apoptotic stimulation in late-passage MSCs, suggesting that the intrinsic apoptotic signalling pathway was not induced by oxidative stress in long-term-cultured MSCs. Based on these results, we propose that some replicative senescent cells may avoid apoptosis signalling via impairment of signalling molecules and accumulation during long-term expansion. Copyright © 2016 John Wiley & Sons, Ltd. PMID:27212655

  17. Macrophages infiltrate the human and rat decidua during term and preterm labor: evidence that decidual inflammation precedes labor.

    PubMed

    Hamilton, Sarah; Oomomian, Yasamin; Stephen, Gillian; Shynlova, Oksana; Tower, Clare L; Garrod, Ainslie; Lye, Stephen J; Jones, Rebecca L

    2012-02-01

    Preterm delivery is the leading cause of perinatal mortality and morbidity. Current tocolytics target myometrial contractions, a late step in the labor cascade. Identifying earlier events in parturition may lead to more effective therapeutic strategies. We hypothesized that inflammatory events in decidua (the maternal-fetal interface), characterized by leucocyte infiltration, are an early event during term and preterm labor (PTL). Leucocyte abundance in decidua of human pregnancies was quantified following term labor and PTL (idiopathic and infection associated), in conjunction with investigation of temporal inflammatory events in rat uterus during the perilabor period and in PTL induced by mifepristone. In human decidua, macrophage numbers were 4-fold higher in term labor (P < 0.01) and 2.5-fold higher in non-infection-associated PTL (P < 0.05) than in term nonlaboring samples. Neutrophil abundance was unchanged with labor but elevated in PTL with infection (5- to 53-fold increase; P < 0.01). T and NK cells were more abundant in idiopathic PTL than TL (P < 0.05). In rat, decidual macrophage infiltration increased 4.5-fold 12 h prior to labor and remained elevated during labor and early postpartum (P < 0.01). Decidual infiltration preceded that of the myometrium and was 4-fold higher (P < 0.01). In rat PTL, decidual macrophage numbers were also elevated (P < 0.01) and exceeded those of the myometrium (P < 0.05). These studies show for the first time that leucocytes infiltrate decidua during labor at term and preterm, supporting a role for leucocyte-derived inflammatory mediators in decidual activation. In the rat, this occurred prior to labor, suggesting it is an early event during parturition and thus a potential target for intervention. PMID:22011391

  18. Human migration to space: Alternative technological approaches for long-term adaptation to extraterrestrial environments and the implications for human evolution

    NASA Astrophysics Data System (ADS)

    Lockard, Elizabeth Song

    As humans embark upon the next phase of Space exploration---establishing human outposts in low-Earth orbit, on the Moon, and on Mars---the scope of human factors must expand beyond the meager requirements for short-term missions to Space to include issues of comfort and well-being necessary for long-term durations. However, to habitate---to dwell in a place---implies more than creature comforts in order to adapt. Human factors research must also include a phenomenological perspective---an understanding of how we experience the places we live in---in order for a community to be robust and to thrive. The first phase of migration will be an especially tenuous one requiring intensive technological intervention. The modes by which those technologies are implemented will have significant bearing on the process of human adaptation: the nature of the mediation can be either one of domination, subordination, avoidance, or integration. Ultimately, adaptation is best ensured if symbiotic processes of negotiation and cooperation between subject and environment are espoused over acts of conquest or acquiescence. The adaptive mechanisms we choose to develop and employ will have wider implications for long-range human evolution. The transformations we will undergo will be influenced by both the initial decision to migrate to Space (technological), as well as the actual conditions of Space (environmental). Migration to extraterrestrial environments will be unequivocally the most profound catalyst for evolution in the history of humankind---not only for the human species itself but also for the new environments we will eventually inhabit. At the same time, we also find ourselves---via a new generation of bio-, nano-, and digital technologies---in the position to consciously and willfully direct our own evolution. Technology has always been transformative, but in the not-so-distant future, we will soon possess the capacity to radically re-invent ourselves in almost any way

  19. Phenotypic and Functional Characterization of Mesenchymal Stem/Multipotent Stromal Cells From Decidua Parietalis of Human Term Placenta.

    PubMed

    Abumaree, Mohamed H; Abomaray, F M; Alshehri, N A; Almutairi, A; AlAskar, A S; Kalionis, B; Al Jumah, M A

    2016-09-01

    Mesenchymal stem/multipotent stromal cells (MSCs) from the human placenta show stem cell-like properties useful for regenerative medicine. Previously, we reported that MSCs isolated from the fetal part of human term placentae have characteristics, which make them a potential candidate for regenerative medicine. In this study, we characterized MSC isolated from the maternal part of human term placenta. The MSCs were isolated from the decidua parietalis (DPMSCs) of human placenta using a digestion method and characterized by colony-forming unit assay and the expression of MSC markers by flow cytometry technique. In addition, DPMSC differentiation into the 3 mesenchymal lineages was also performed. Moreover, the gene and protein expression profiles of DPMSCs were identified by real-time polymerase chain reaction and flow cytometry techniques, respectively. Furthermore, proteins secreted by DPMSCs were detected by sandwich enzyme-linked immunosorbent assays. Finally, the proliferation and migration potentials of DPMSCs were also determined. The DPMSCs were positive for MSC markers and negative for hematopoietic and endothelial markers, as well as costimulatory molecules and HLA-DR. Functionally, DPMSCs formed colonies and differentiated into chondrocytes, osteocytes, and adipocytes. In addition, they proliferated and migrated in response to different stimuli. Finally, they expressed and secreted many biological and immunological factors with multiple functions. Here, we carry out an extensive characterization of DPMSCs of human placenta. We report that these cells express and secrete a wide range of molecules with multiple functions, and therefore, we suggest that these cells could be an attractive candidate for cell-based therapy. PMID:26902429

  20. Changes in the long-term hydrological regimes and the impacts of human activities in the main Wei River, China

    NASA Astrophysics Data System (ADS)

    Zhang, Hongbo; Huang, Qiang; Zhang, Qiang; Gu, Lei; Chen, Keyu; Yu, Qijun

    2016-03-01

    Under the combined influence of climate changes and human activities, the hydrological regime of the Wei River shows remarkable variations which have caused many issues in the Wei River in recent decades, such as a lack of freshwater, water pollution, disastrous flooding and channel sedimentation. Hence, hydrological regime changes and potential human-induced impacts have been drawing increasing attention from local government and hydrologists. This study investigates hydrological regime changes in the natural and measured runoff series at four hydrological stations on the main Wei River and quantifies features of their long-term change by analysing their historical annual and seasonal runoff data using several approaches, i.e., continuous wavelet transform, cross-wavelet, wavelet coherence, trend-free pre-whitening Mann-Kendall test and detrended fluctuation analysis. By contrasting two different analysis results between natural and measured river runoff series, the impacts of human activities on the long-term hydrological regime were investigated via the changes of spatio-temporal distribution in dominant periods, the trends and long-range memory of river runoff. The results show : (a) that periodic properties of the streamflow changes are the result of climate, referring to precipitation changes in particular, while human activities play a minor role; (b) a significant decreasing trend can be observed in the natural streamflow series along the entire main stream of the Wei River and the more serious decrease emerging in measured flow should result from human-induced influences in recent decades; and (c) continuous decreasing streamflow in the Wei River will trigger serious shortages of freshwater in the future, which may challenge the sustainability and safety of water resources development in the river basin, and should be paid great attention before 2020.

  1. Representation of Instantaneous and Short-Term Loudness in the Human Cortex.

    PubMed

    Thwaites, Andrew; Glasberg, Brian R; Nimmo-Smith, Ian; Marslen-Wilson, William D; Moore, Brian C J

    2016-01-01

    Acoustic signals pass through numerous transforms in the auditory system before perceptual attributes such as loudness and pitch are derived. However, relatively little is known as to exactly when these transformations happen, and where, cortically or sub-cortically, they occur. In an effort to examine this, we investigated the latencies and locations of cortical entrainment to two transforms predicted by a model of loudness perception for time-varying sounds: the transforms were instantaneous loudness and short-term loudness, where the latter is hypothesized to be derived from the former and therefore should occur later in time. Entrainment of cortical activity was estimated from electro- and magneto-encephalographic (EMEG) activity, recorded while healthy subjects listened to continuous speech. There was entrainment to instantaneous loudness bilaterally at 45, 100, and 165 ms, in Heschl's gyrus, dorsal lateral sulcus, and Heschl's gyrus, respectively. Entrainment to short-term loudness was found in both the dorsal lateral sulcus and superior temporal sulcus at 275 ms. These results suggest that short-term loudness is derived from instantaneous loudness, and that this derivation occurs after processing in sub-cortical structures. PMID:27199645

  2. Representation of Instantaneous and Short-Term Loudness in the Human Cortex

    PubMed Central

    Thwaites, Andrew; Glasberg, Brian R.; Nimmo-Smith, Ian; Marslen-Wilson, William D.; Moore, Brian C. J.

    2016-01-01

    Acoustic signals pass through numerous transforms in the auditory system before perceptual attributes such as loudness and pitch are derived. However, relatively little is known as to exactly when these transformations happen, and where, cortically or sub-cortically, they occur. In an effort to examine this, we investigated the latencies and locations of cortical entrainment to two transforms predicted by a model of loudness perception for time-varying sounds: the transforms were instantaneous loudness and short-term loudness, where the latter is hypothesized to be derived from the former and therefore should occur later in time. Entrainment of cortical activity was estimated from electro- and magneto-encephalographic (EMEG) activity, recorded while healthy subjects listened to continuous speech. There was entrainment to instantaneous loudness bilaterally at 45, 100, and 165 ms, in Heschl's gyrus, dorsal lateral sulcus, and Heschl's gyrus, respectively. Entrainment to short-term loudness was found in both the dorsal lateral sulcus and superior temporal sulcus at 275 ms. These results suggest that short-term loudness is derived from instantaneous loudness, and that this derivation occurs after processing in sub-cortical structures. PMID:27199645

  3. Long-term Interaction of an Iron Fragment with Living Human Tissue

    NASA Astrophysics Data System (ADS)

    Donggao, Zhao; Meifu, Zhou

    An iron fragment was embedded accidentally in a human body and remained inside for nearly 16 years. The fragment underwent significant morphological and chemical changes. The surface of the fragment developed a botryoidal or oolitic form. The fragment was altered to iron oxides and hydroxides and Ca phosphates (likely apatite). Fe, O, P, Ca, Cl, Na, K, and Mg were identified in the fragment. From the rim to the core, the Fe content increased and the P and Ca contents decreased. The fragment absorbed Ca, P, O, Cl, Na, and K from the body. This study shows that apatite or other Ca phosphates can remain stable for as long as 16 years. However, the Ca phosphate is mixed with Fe oxides or hydroxides, and therefore, it may not be strong enough to bond to bone. This study also shows that Fe or Fe-bearing alloys are not stable inside a human body.

  4. Ecological consequences of human niche construction: Examining long-term anthropogenic shaping of global species distributions.

    PubMed

    Boivin, Nicole L; Zeder, Melinda A; Fuller, Dorian Q; Crowther, Alison; Larson, Greger; Erlandson, Jon M; Denham, Tim; Petraglia, Michael D

    2016-06-01

    The exhibition of increasingly intensive and complex niche construction behaviors through time is a key feature of human evolution, culminating in the advanced capacity for ecosystem engineering exhibited by Homo sapiens A crucial outcome of such behaviors has been the dramatic reshaping of the global biosphere, a transformation whose early origins are increasingly apparent from cumulative archaeological and paleoecological datasets. Such data suggest that, by the Late Pleistocene, humans had begun to engage in activities that have led to alterations in the distributions of a vast array of species across most, if not all, taxonomic groups. Changes to biodiversity have included extinctions, extirpations, and shifts in species composition, diversity, and community structure. We outline key examples of these changes, highlighting findings from the study of new datasets, like ancient DNA (aDNA), stable isotopes, and microfossils, as well as the application of new statistical and computational methods to datasets that have accumulated significantly in recent decades. We focus on four major phases that witnessed broad anthropogenic alterations to biodiversity-the Late Pleistocene global human expansion, the Neolithic spread of agriculture, the era of island colonization, and the emergence of early urbanized societies and commercial networks. Archaeological evidence documents millennia of anthropogenic transformations that have created novel ecosystems around the world. This record has implications for ecological and evolutionary research, conservation strategies, and the maintenance of ecosystem services, pointing to a significant need for broader cross-disciplinary engagement between archaeology and the biological and environmental sciences. PMID:27274046

  5. Ecological consequences of human niche construction: Examining long-term anthropogenic shaping of global species distributions

    PubMed Central

    Boivin, Nicole L.; Zeder, Melinda A.; Fuller, Dorian Q.; Crowther, Alison; Larson, Greger; Erlandson, Jon M.; Denham, Tim; Petraglia, Michael D.

    2016-01-01

    The exhibition of increasingly intensive and complex niche construction behaviors through time is a key feature of human evolution, culminating in the advanced capacity for ecosystem engineering exhibited by Homo sapiens. A crucial outcome of such behaviors has been the dramatic reshaping of the global biosphere, a transformation whose early origins are increasingly apparent from cumulative archaeological and paleoecological datasets. Such data suggest that, by the Late Pleistocene, humans had begun to engage in activities that have led to alterations in the distributions of a vast array of species across most, if not all, taxonomic groups. Changes to biodiversity have included extinctions, extirpations, and shifts in species composition, diversity, and community structure. We outline key examples of these changes, highlighting findings from the study of new datasets, like ancient DNA (aDNA), stable isotopes, and microfossils, as well as the application of new statistical and computational methods to datasets that have accumulated significantly in recent decades. We focus on four major phases that witnessed broad anthropogenic alterations to biodiversity—the Late Pleistocene global human expansion, the Neolithic spread of agriculture, the era of island colonization, and the emergence of early urbanized societies and commercial networks. Archaeological evidence documents millennia of anthropogenic transformations that have created novel ecosystems around the world. This record has implications for ecological and evolutionary research, conservation strategies, and the maintenance of ecosystem services, pointing to a significant need for broader cross-disciplinary engagement between archaeology and the biological and environmental sciences. PMID:27274046

  6. [Detection of stimulator-induced cytotoxicity of human mononuclear cells in short-term culture].

    PubMed

    von Baehr, R; Timm, M; Fröbe, I

    1983-01-01

    A new test modification for the detection of stimulant-induced cytotoxicity of human mononuclear blood cells is described. Papain-treated human erythrocytes were used as indicator cells. The effector cells were lymphocytes. The ratio of target cells to effector cells was 10/1. Haemoglobin as a marker of lysis of the erythrocytes, released in the supernatant, was measured quantitatively in form of its pseudoperoxidase-activity. PHA, ConA and tannic acid were ascertained and tested as stimulants of cytotoxicity. The reaction was inhibitable by anti-human-lymphocyte-globulin. The test conditions were optimized in regard to incubation time, -temperature, -vessels, culture medium and target cells. The technique is easy to manipulate, has only slight pretensions to the equipment of the laboratory and appears to be very effective. We recommend to apply this method of stimulant-induced cytotoxicity within the detection of the immune state, especially in the progress of immunopathological diseases and the analysis of efficiency of immunosuppressive therapy. PMID:6224413

  7. Effect of General Anesthesia in Infancy on Long-Term Recognition Memory in Humans and Rats

    PubMed Central

    Stratmann, Greg; Lee, Joshua; Sall, Jeffrey W; Lee, Bradley H; Alvi, Rehan S; Shih, Jennifer; Rowe, Allison M; Ramage, Tatiana M; Chang, Flora L; Alexander, Terri G; Lempert, David K; Lin, Nan; Siu, Kasey H; Elphick, Sophie A; Wong, Alice; Schnair, Caitlin I; Vu, Alexander F; Chan, John T; Zai, Huizhen; Wong, Michelle K; Anthony, Amanda M; Barbour, Kyle C; Ben-Tzur, Dana; Kazarian, Natalie E; Lee, Joyce YY; Shen, Jay R; Liu, Eric; Behniwal, Gurbir S; Lammers, Cathy R; Quinones, Zoel; Aggarwal, Anuj; Cedars, Elizabeth; Yonelinas, Andrew P; Ghetti, Simona

    2014-01-01

    Anesthesia in infancy impairs performance in recognition memory tasks in mammalian animals, but it is unknown if this occurs in humans. Successful recognition can be based on stimulus familiarity or recollection of event details. Several brain structures involved in recollection are affected by anesthesia-induced neurodegeneration in animals. Therefore, we hypothesized that anesthesia in infancy impairs recollection later in life in humans and rats. Twenty eight children ages 6–11 who had undergone a procedure requiring general anesthesia before age 1 were compared with 28 age- and gender-matched children who had not undergone anesthesia. Recollection and familiarity were assessed in an object recognition memory test using receiver operator characteristic analysis. In addition, IQ and Child Behavior Checklist scores were assessed. In parallel, thirty three 7-day-old rats were randomized to receive anesthesia or sham anesthesia. Over 10 months, recollection and familiarity were assessed using an odor recognition test. We found that anesthetized children had significantly lower recollection scores and were impaired at recollecting associative information compared with controls. Familiarity, IQ, and Child Behavior Checklist scores were not different between groups. In rats, anesthetized subjects had significantly lower recollection scores than controls while familiarity was unaffected. Rats that had undergone tissue injury during anesthesia had similar recollection indices as rats that had been anesthetized without tissue injury. These findings suggest that general anesthesia in infancy impairs recollection later in life in humans and rats. In rats, this effect is independent of underlying disease or tissue injury. PMID:24910347

  8. Effect of general anesthesia in infancy on long-term recognition memory in humans and rats.

    PubMed

    Stratmann, Greg; Lee, Joshua; Sall, Jeffrey W; Lee, Bradley H; Alvi, Rehan S; Shih, Jennifer; Rowe, Allison M; Ramage, Tatiana M; Chang, Flora L; Alexander, Terri G; Lempert, David K; Lin, Nan; Siu, Kasey H; Elphick, Sophie A; Wong, Alice; Schnair, Caitlin I; Vu, Alexander F; Chan, John T; Zai, Huizhen; Wong, Michelle K; Anthony, Amanda M; Barbour, Kyle C; Ben-Tzur, Dana; Kazarian, Natalie E; Lee, Joyce Y Y; Shen, Jay R; Liu, Eric; Behniwal, Gurbir S; Lammers, Cathy R; Quinones, Zoel; Aggarwal, Anuj; Cedars, Elizabeth; Yonelinas, Andrew P; Ghetti, Simona

    2014-09-01

    Anesthesia in infancy impairs performance in recognition memory tasks in mammalian animals, but it is unknown if this occurs in humans. Successful recognition can be based on stimulus familiarity or recollection of event details. Several brain structures involved in recollection are affected by anesthesia-induced neurodegeneration in animals. Therefore, we hypothesized that anesthesia in infancy impairs recollection later in life in humans and rats. Twenty eight children ages 6-11 who had undergone a procedure requiring general anesthesia before age 1 were compared with 28 age- and gender-matched children who had not undergone anesthesia. Recollection and familiarity were assessed in an object recognition memory test using receiver operator characteristic analysis. In addition, IQ and Child Behavior Checklist scores were assessed. In parallel, thirty three 7-day-old rats were randomized to receive anesthesia or sham anesthesia. Over 10 months, recollection and familiarity were assessed using an odor recognition test. We found that anesthetized children had significantly lower recollection scores and were impaired at recollecting associative information compared with controls. Familiarity, IQ, and Child Behavior Checklist scores were not different between groups. In rats, anesthetized subjects had significantly lower recollection scores than controls while familiarity was unaffected. Rats that had undergone tissue injury during anesthesia had similar recollection indices as rats that had been anesthetized without tissue injury. These findings suggest that general anesthesia in infancy impairs recollection later in life in humans and rats. In rats, this effect is independent of underlying disease or tissue injury. PMID:24910347

  9. The prognostic value of non-perfusion variables obtained during vasodilator stress myocardial perfusion imaging.

    PubMed

    Bajaj, Navkaranbir S; Singh, Siddharth; Farag, Ayman; El-Hajj, Stephanie; Heo, Jack; Iskandrian, Ami E; Hage, Fadi G

    2016-06-01

    Myocardial perfusion imaging (MPI) is an established diagnostic test that provides useful prognostic data in patients with known or suspected coronary artery disease. In more than half of the patients referred for stress testing, vasodilator stress is used in lieu of exercise. Unlike exercise, vasodilator stress does not provide information on exercise and functional capacity, heart rate recovery, and chronotropy, and ECG changes are less frequent. These non-perfusion data provide important prognostic and patient management information. Further, event rates in patients undergoing vasodilator MPI are higher than in those undergoing exercise MPI and even in those with normal images probably due to higher pretest risk. However, there are a number of non-perfusion variables that are obtained during vasodilator stress testing, which have prognostic relevance but their use has not been well emphasized. The purpose of this review is to summarize the prognostic values of these non-perfusion data obtained during vasodilator MPI. PMID:26940574

  10. Gradient-enhanced FAWSETS perfusion measurements

    NASA Astrophysics Data System (ADS)

    Marro, Kenneth I.; Lee, Donghoon; Hyyti, Outi M.

    2005-08-01

    This work describes the use of custom-built gradients to enhance skeletal muscle perfusion measurements acquired with a previously described arterial spin labeling technique known as FAWSETS (flow-driven arterial water stimulation with elimination of tissue signal). Custom-built gradients provide active control of the static magnetic field gradient on which FAWSETS relies for labeling. This allows selective, 180° modulations of the phase of the perfusion component of the signal. Phase cycling can then be implemented to eliminate all extraneous components leaving a signal that exclusively reflects capillary-level perfusion. Gradient-enhancement substantially reduces acquisition time and eliminates the need to acquire an ischemic signal to quantify perfusion. This removes critical obstacles to application of FAWSETS in organs other than skeletal muscle and makes the measurements more desirable for clinical environments. The basic physical principles of gradient-enhancement are demonstrated in flow phantom experiments and in vivo utility is demonstrated in rat hind limb during stimulated exercise.

  11. Urate synthesis in the perfused chick liver

    PubMed Central

    Barratt, Eileen; Buttery, Peter J.; Boorman, K. Neil

    1974-01-01

    Urate synthesis was studied in a perfused chicken liver preparation. The perfused liver had an ATP/ADP ratio of 0.29±0.05(6) compared with 0.34±0.07(10) in liver obtained from chicks under ether anaesthesia. Lactate/pyruvate ratios were 9.4±1.7(5) in the perfused liver and 14.8±1.8(5) in the rapidly sampled liver. Urate synthesis was only marginally stimulated by glycine, glutamine, aspartic acid or NH4Cl, but significant increases were observed with phosphoribosyl pyrophosphate, aminoimidazolecarboxylic acid riboside, inosine, inosinic acid and xanthine. Urate synthesis from glycine, glutamine, NH4Cl, asparagine, alanine, histidine and a mixture of 21 amino acids was obtained on inclusion of insulin in the perfusion medium. Evidence for the inclusion of the carbon of histidine into uric acid was obtained. Aspects of the energy consumption associated with the conversion of excess of amino acid into uric acid are considered. PMID:4462579

  12. Automated sonographic evaluation of testicular perfusion

    NASA Astrophysics Data System (ADS)

    Thierman, Jonathan S.; Clement, Gregory T.; Kalish, Leslie A.; O'Kane, Patrick L.; Frauscher, Ferdinand; Paltiel, Harriet J.

    2006-07-01

    Contrast-enhanced ultrasound (US) imaging is potentially applicable to the investigation of vascular disorders of the testis. We investigated the ability of two automated computer algorithms to analyse contrast-enhanced pulse inversion US data in a rabbit model of unilateral testicular ischaemia and to correctly determine relative testicular perfusion: nonlinear curve fitting of the US backscatter intensity as a function of time; and spectral analysis of the intensity time trace. We compared (i) five metrics based on the algorithmic data to testicular perfusion ratios obtained with radiolabelled microspheres, a reference standard; (ii) qualitative assessment of the US images by two independent readers blinded to the side of the experimental and control testes to the radiolabelled microsphere perfusion ratios; and (iii) results of the algorithmically-derived metrics to the qualitative assessments of the two readers. For the curve fit method, the algorithmically-derived metrics agreed with the reference standard in 54% to 68% of all cases. For the spectral method, the results agreed in 70% of all cases. The two readers agreed with the reference standard in 40% and 35% of all cases, respectively. These results suggest that automated methods of analysis may provide useful information in the assessment of testicular perfusion.

  13. Asynchronicity of Facial Blood Perfusion in Migraine

    PubMed Central

    Zaproudina, Nina; Teplov, Victor; Nippolainen, Ervin; Lipponen, Jukka A.; Kamshilin, Alexei A.; Närhi, Matti; Karjalainen, Pasi A.; Giniatullin, Rashid

    2013-01-01

    Asymmetrical changes in blood perfusion and asynchronous blood supply to head tissues likely contribute to migraine pathophysiology. Imaging was widely used in order to understand hemodynamic variations in migraine. However, mapping of blood pulsations in the face of migraineurs has not been performed so far. We used the Blood Pulsation Imaging (BPI) technique, which was recently developed in our group, to establish whether 2D-imaging of blood pulsations parameters can reveal new biomarkers of migraine. BPI characteristics were measured in migraineurs during the attack-free interval and compared to healthy subjects with and without a family history of migraine. We found a novel phenomenon of transverse waves of facial blood perfusion in migraineurs in contrast to healthy subjects who showed synchronous blood delivery to both sides of the face. Moreover, the amplitude of blood pulsations was symmetrically distributed over the face of healthy subjects, but asymmetrically in migraineurs and subjects with a family history of migraine. In the migraine patients we found a remarkable correlation between the side of unilateral headache and the direction of the blood perfusion wave. Our data suggest that migraine is associated with lateralization of blood perfusion and asynchronous blood pulsations in the facial area, which could be due to essential dysfunction of the autonomic vascular control in the face. These findings may further enhance our understanding of migraine pathophysiology and suggest new easily available biomarkers of this pathology. PMID:24324592

  14. Simplified prototyping of perfusable polystyrene microfluidics

    PubMed Central

    Tran, Reginald; Ahn, Byungwook; R. Myers, David; Qiu, Yongzhi; Sakurai, Yumiko; Moot, Robert; Mihevc, Emma; Trent Spencer, H.; Doering, Christopher; A. Lam, Wilbur

    2014-01-01

    Cell culture in microfluidic systems has primarily been conducted in devices comprised of polydimethylsiloxane (PDMS) or other elastomers. As polystyrene (PS) is the most characterized and commonly used substrate material for cell culture, microfluidic cell culture would ideally be conducted in PS-based microsystems that also enable tight control of perfusion and hydrodynamic conditions, which are especially important for culture of vascular cell types. Here, we report a simple method to prototype perfusable PS microfluidics for endothelial cell culture under flow that can be fabricated using standard lithography and wet laboratory equipment to enable stable perfusion at shear stresses up to 300 dyn/cm2 and pumping pressures up to 26 kPa for at least 100 h. This technique can also be extended to fabricate perfusable hybrid PS-PDMS microfluidics of which one application is for increased efficiency of viral transduction in non-adherent suspension cells by leveraging the high surface area to volume ratio of microfluidics and adhesion molecules that are optimized for PS substrates. These biologically compatible microfluidic devices can be made more accessible to biological-based laboratories through the outsourcing of lithography to various available microfluidic foundries. PMID:25379106

  15. Nuclear cardiology: Myocardial perfusion and function

    SciTech Connect

    Seldin, D.W. )

    1991-08-01

    Myocardial perfusion studies continue to be a major focus of research, with new investigations of the relationship of exercise-redistribution thallium imaging to diagnosis, prognosis, and case management. The redistribution phenomenon, which seemed to be fairly well understood a few years ago, is now recognized to be much more complex than originally thought, and various strategies have been proposed to clarify the meaning of persistent defects. Pharmacologic intervention with dipyridamole and adenosine has become available as an alternative to exercise, and comparisons with exercise imaging and catheterization results have been described. Thallium itself is no longer the sole single-photon perfusion radiopharmaceutical; two new technetium agents are now widely available. In addition to perfusion studies, advances in the study of ventricular function have been made, including reports of studies performed in conjunction with technetium perfusion studies, new insights into cardiac physiology, and the prognostic and case-management information that function studies provide. Finally, work has continued with monoclonal antibodies for the identification of areas of myocyte necrosis. 41 references.

  16. High-resolution renal perfusion mapping using contrast-enhanced ultrasonography in ischemia-reperfusion injury monitors changes in renal microperfusion.

    PubMed

    Fischer, Krisztina; Meral, F Can; Zhang, Yongzhi; Vangel, Mark G; Jolesz, Ferenc A; Ichimura, Takaharu; Bonventre, Joseph V

    2016-06-01

    Alterations in renal microperfusion play an important role in the development of acute kidney injury with long-term consequences. Here we used contrast-enhanced ultrasonography as a novel method for depicting intrarenal distribution of blood flow. After infusion of microbubble contrast agent, bubbles were collapsed in the kidney and postbubble destruction refilling was measured in various regions of the kidney. Local perfusion was monitored in vivo at 15, 30, 45, 60 minutes and 24 hours after 28 minutes of bilateral ischemia in 12 mice. High-resolution, pixel-by-pixel analysis was performed on each imaging clip using customized software, yielding parametric perfusion maps of the kidney, representing relative blood volume in each pixel. These perfusion maps revealed that outer medullary perfusion decreased disproportionately to the reduction in the cortical and inner medullary perfusion after ischemia. Outer medullary perfusion was significantly decreased by 69% at 60 minutes postischemia and remained significantly less (40%) than preischemic levels at 24 hours postischemia. Thus, contrast-enhanced ultrasonography with high-resolution parametric perfusion maps can monitor changes in renal microvascular perfusion in space and time in mice. This novel technique can be translated to clinical use in man. PMID:27165821

  17. Bile salt-stimulated lipase of human milk: characterization of the enzyme from preterm and term milk

    SciTech Connect

    Freed, L.M.; Hamosh, P.; Hamosh, M.

    1986-03-01

    The bile salt-stimulated lipase (BSSL) of human milk is an important digestive enzyme in the newborn whose pancreatic function is immature. Milk from mothers delivering premature infants (preterm milk) has similar levels of BSSL activity to that of mothers of term infants (term milk). This study has determined whether the BSSL in preterm milk has the same characteristics as that in term milk. Milk samples were collected during the first 12 wk of lactation from seven mothers of infants born at 26-30 wk (very preterm, VPT), 31-37 wk (preterm, PT) and 37-42 wk (term, T) gestation. BSSL activity was measured using /sup 3/H-triolein emulsion as substrate. Time course, bile salt and enzyme concentration, pH and pH stability were studied, as well as inhibition of BSSL by eserine. The characteristics of BSSL from preterm and term milk were identical as were comparisons between colostrum and mature milk BSSL. BSSL from all milk sources had a neutral-to-alkaline pH optimum (pH 7.3-8.9), was stable at low pH for 60 min, and was 95-100% inhibited by eserine (greater than or equal to 0.6 mM). BSSL activity, regardless of enzyme source, was bile-salt dependent and was stimulated only by primary bile salts (taurocholate, glycocholate). The data indicate that the BSSL in milks of mothers delivering as early as 26 wk gestation is identical to that in term milk.

  18. The influence of natural feeding on human health: short- and long-term perspectives

    PubMed Central

    Woźniak, Urszula; Czyżewska, Krystyna

    2014-01-01

    Breastfeeding is the most appropriate way to nourish infants. It promotes proper physical and intellectual development of the child. Human milk is unique and impossible to replicate with any other kind of food. However, using maternal milk not only has beneficial effects on the infant's health but it can also help to prevent illnesses in adulthood. Breastfeeding improves immunity and consequently decreases the occurrence of infections, especially those of the gastrointestinal tract and respiratory tract. Moreover, it helps to reduce the risk of some disorders such as allergies, diabetes mellitus type 1, obesity and arterial hypertension. PMID:24868292

  19. The influence of natural feeding on human health: short- and long-term perspectives.

    PubMed

    Grzelak, Teresa; Woźniak, Urszula; Czyżewska, Krystyna

    2014-01-01

    Breastfeeding is the most appropriate way to nourish infants. It promotes proper physical and intellectual development of the child. Human milk is unique and impossible to replicate with any other kind of food. However, using maternal milk not only has beneficial effects on the infant's health but it can also help to prevent illnesses in adulthood. Breastfeeding improves immunity and consequently decreases the occurrence of infections, especially those of the gastrointestinal tract and respiratory tract. Moreover, it helps to reduce the risk of some disorders such as allergies, diabetes mellitus type 1, obesity and arterial hypertension. PMID:24868292

  20. In situ measurements of magnetic nanoparticles after placenta perfusion

    NASA Astrophysics Data System (ADS)

    Müller, Robert; Gläser, Marcus; Göhner, Claudia; Seyfarth, Lydia; Schleussner, Ekkehard; Hofmann, Andreas; Fritzsche, Wolfgang

    2015-04-01

    Nanoparticles (NP) present promising tools for medical applications. However, the investigation of their spatial and temporal distribution is hampered by missing in-situ particle detection and quantification technologies. The placenta perfusion experiment represents an interesting model for the study of the particle distribution at a biological barrier. It allows the ex-vivo investigation of the permeability of the placenta for materials of interest. We introduce an approach based on a magnetic system for an in situ measurement of the concentration of magnetic NPs in such an experiment. A previously off-line utilized magnetic readout device (sensitivity of ≈10-8 Am2) was used for long term measurements of magnetic NP of 100-150 nm size range in a closed circuit of a placenta perfusion. It represents a semiquantitative approach. The behavior of particles in the placenta and in the measurement system was studied, as well as the influence of particle surface modifications. The results suggest a transfer of a low amount of particles from the maternal to the fetal blood circuit.

  1. Bayesian hemodynamic parameter estimation by bolus tracking perfusion weighted imaging.

    PubMed

    Boutelier, Timothé; Kudo, Koshuke; Pautot, Fabrice; Sasaki, Makoto

    2012-07-01

    A delay-insensitive probabilistic method for estimating hemodynamic parameters, delays, theoretical residue functions, and concentration time curves by computed tomography (CT) and magnetic resonance (MR) perfusion weighted imaging is presented. Only a mild stationarity hypothesis is made beyond the standard perfusion model. New microvascular parameters with simple hemodynamic interpretation are naturally introduced. Simulations on standard digital phantoms show that the method outperforms the oscillating singular value decomposition (oSVD) method in terms of goodness-of-fit, linearity, statistical and systematic errors on all parameters, especially at low signal-to-noise ratios (SNRs). Delay is always estimated sharply with user-supplied resolution and is purely arterial, by contrast to oSVD time-to-maximum TMAX that is very noisy and biased by mean transit time (MTT), blood volume, and SNR. Residue functions and signals estimates do not suffer overfitting anymore. One CT acute stroke case confirms simulation results and highlights the ability of the method to reliably estimate MTT when SNR is low. Delays look promising for delineating the arterial occlusion territory and collateral circulation. PMID:22410325

  2. Perfused drop microfluidic device for brain slice culture-based drug discovery.

    PubMed

    Liu, Jing; Pan, Liping; Cheng, Xuanhong; Berdichevsky, Yevgeny

    2016-06-01

    Living slices of brain tissue are widely used to model brain processes in vitro. In addition to basic neurophysiology studies, brain slices are also extensively used for pharmacology, toxicology, and drug discovery research. In these experiments, high parallelism and throughput are critical. Capability to conduct long-term electrical recording experiments may also be necessary to address disease processes that require protein synthesis and neural circuit rewiring. We developed a novel perfused drop microfluidic device for use with long term cultures of brain slices (organotypic cultures). Slices of hippocampus were placed into wells cut in polydimethylsiloxane (PDMS) film. Fluid level in the wells was hydrostatically controlled such that a drop was formed around each slice. The drops were continuously perfused with culture medium through microchannels. We found that viable organotypic hippocampal slice cultures could be maintained for at least 9 days in vitro. PDMS microfluidic network could be readily integrated with substrate-printed microelectrodes for parallel electrical recordings of multiple perfused organotypic cultures on a single MEA chip. We expect that this highly scalable perfused drop microfluidic device will facilitate high-throughput drug discovery and toxicology. PMID:27194028

  3. Non-invasive long-term recordings of cortical 'direct current' (DC-) activity in humans using magnetoencephalography.

    PubMed

    Mackert, B M; Wübbeler, G; Burghoff, M; Marx, P; Trahms, L; Curio, G

    1999-10-01

    Recently, biomagnetic fields below 0.1 Hz arising from nerve or muscle injury currents have been measured non-invasively using superconducting quantum interference devices (SQUIDs). Here we report first long-term recordings of cortical direct current (DC) fields in humans based on a horizontal modulation (0.4 Hz) of the body and, respectively, head position beneath the sensor array: near-DC fields with amplitudes between 90 and 540 fT were detected in 5/5 subjects over the auditory cortex throughout prolonged stimulation periods (here: 30 s) during which subjects were listening to concert music. These results prove the feasibility to record non-invasively low amplitude near-DC magnetic fields of the human brain and open the perspective for studies on DC-phenomena in stroke, such as anoxic depolarization or periinfarct depolarization, and in migraine patients. PMID:10515183

  4. The expression and localization of mRNA for colony-stimulating factor (CSF)-1 in human term placenta.

    PubMed

    Kanzaki, H; Yui, J; Iwai, M; Imai, K; Kariya, M; Hatayama, H; Mori, T; Guilbert, L J; Wegmann, T G

    1992-04-01

    A 4-kb mRNA for colony-stimulating factor 1 (CSF-1) was detected in normal human placenta at term by Northern blot analysis. In-situ hybridization revealed that the mRNA for CSF-1 was localized in the mesenchymal cells of the chorionic villous stroma, but not in the trophoblasts or capillary epithelial cells. Because there are significant numbers of tissue macrophages (Hofbauer cells) in the placental stroma and because the receptor for CSF-1 (the c-fms proto-oncogene product) is known to be expressed by trophoblasts, our results suggest that CSF-1 produced by placental stromal cells may act as a growth and survival factor for human placental macrophages and trophoblasts. PMID:1522204

  5. Comparing Normothermic Machine Perfusion Preservation With Different Perfusates on Porcine Livers From Donors After Circulatory Death.

    PubMed

    Liu, Q; Nassar, A; Farias, K; Buccini, L; Mangino, M J; Baldwin, W; Bennett, A; O'Rourke, C; Iuppa, G; Soliman, B G; Urcuyo-Llanes, D; Okamoto, T; Uso, T D; Fung, J; Abu-Elmagd, K; Miller, C; Quintini, C

    2016-03-01

    The utilization of normothermic machine perfusion (NMP) may be an effective strategy to resuscitate livers from donation after circulatory death (DCD). There is no consensus regarding the efficacy of different perfusates on graft and bile duct viability. The aim of this study was to compare, in an NMP porcine DCD model, the preservation potential of three different perfusates. Twenty porcine livers with 60 min of warm ischemia were separated into four preservation groups: cold storage (CS), NMP with Steen solution (Steen; XVIVO Perfusion Inc., Denver, CO), Steen plus red blood cells (RBCs), or whole blood (WB). All livers were preserved for 10 h and reperfused to simulate transplantation for 24 h. During preservation, the NMP with Steen group presented the highest hepatocellular injury. At reperfusion, the CS group had the lowest bile production and the worst hepatocellular injury compared with all other groups, followed by NMP with Steen; the Steen plus RBC and WB groups presented the best functional and hepatocellular injury outcomes, with WB livers showing lower aspartate aminotransferase release and a trend toward better results for most parameters. Based on our results, a perfusate that contains an oxygen carrier is most effective in a model of NMP porcine DCD livers compared with Steen solution. Specifically, WB-perfused livers showed a trend toward better outcomes compared with Steen plus RBCs. PMID:26663737

  6. Human factors and nuclear space technology in long-term exploration

    SciTech Connect

    Brown-VanHoozer, S.A.; VanHoozer, W.R.

    2000-07-01

    Allocation of manual versus automated tasks for operation and maintenance of nuclear power systems in space will be crucial at the onset and at the return of a space flight. Such factors as space adaptation syndrome (SAS), a temporary space motion sickness that has affected 40 to 50% of crew members on past space flights, can result in lost effort ranging from a few hours to a full day. This could have a significant impact on manual performance where high levels of execution are likely to be required in the very early stages of the mission. Other considerations involving higher-level behavioral phenomena such as interpersonal and group processes, individual belief systems, social and motivational factors, and (subjective) cognitive function have received little attention; nevertheless these will be essential elements for success in long-term exploration. Understanding that long-term space flight missions may create groups that become unique societies distinct unto themselves will test current ethical, moral, and social belief systems, requiring one to examine the amalgamation as well as organizational structures for the safety and balance of the crew.

  7. Perfusion Neuroimaging Abnormalities Alone Distinguish National Football League Players from a Healthy Population

    PubMed Central

    Amen, Daniel G.; Willeumier, Kristen; Omalu, Bennet; Newberg, Andrew; Raghavendra, Cauligi; Raji, Cyrus A.

    2016-01-01

    Background: National Football League (NFL) players are exposed to multiple head collisions during their careers. Increasing awareness of the adverse long-term effects of repetitive head trauma has raised substantial concern among players, medical professionals, and the general public. Objective: To determine whether low perfusion in specific brain regions on neuroimaging can accurately separate professional football players from healthy controls. Method: A cohort of retired and current NFL players (n = 161) were recruited in a longitudinal study starting in 2009 with ongoing interval follow up. A healthy control group (n = 124) was separately recruited for comparison. Assessments included medical examinations, neuropsychological tests, and perfusion neuroimaging with single photon emission computed tomography (SPECT). Perfusion estimates of each scan were quantified using a standard atlas. We hypothesized that hypoperfusion particularly in the orbital frontal, anterior cingulate, anterior temporal, hippocampal, amygdala, insular, caudate, superior/mid occipital, and cerebellar sub-regions alone would reliably separate controls from NFL players. Cerebral perfusion differences were calculated using a one-way ANOVA and diagnostic separation was determined with discriminant and automatic linear regression predictive models. Results: NFL players showed lower cerebral perfusion on average (p < 0.01) in 36 brain regions. The discriminant analysis subsequently distinguished NFL players from controls with 90% sensitivity, 86% specificity, and 94% accuracy (95% CI 95-99). Automatic linear modeling achieved similar results. Inclusion of age and clinical co-morbidities did not improve diagnostic classification. Conclusion: Specific brain regions commonly damaged in traumatic brain injury show abnormally low perfusion on SPECT in professional NFL players. These same regions alone can distinguish this group from healthy subjects with high diagnostic accuracy. This

  8. Long term Glycemic Control Using Polymer Encapsulated, Human Stem-Cell Derived β-cells in Immune Competent mice

    PubMed Central

    Vegas, Arturo J.; Veiseh, Omid; Gürtler, Mads; Millman, Jeffrey R.; Pagliuca, Felicia W.; Bader, Andrew R.; Doloff, Joshua C.; Li, Jie; Chen, Michael; Olejnik, Karsten; Tam, Hok Hei; Jhunjhunwala, Siddharth; Langan, Erin; Aresta-Dasilva, Stephanie; Gandham, Srujan; McGarrigle, James; Bochenek, Matthew A.; Hollister-Lock, Jennifer; Oberholzer, Jose; Greiner, Dale L.; Weir, Gordon C.; Melton, Douglas A.; Langer, Robert; Anderson, Daniel G.

    2016-01-01

    The transplantation of glucose-responsive, insulin-producing cells offers the potential for restoring glycemic control in diabetic patients1. Pancreas transplantation and the infusion of cadaveric islets are currently implemented clinically2, but are limited by the adverse effects of lifetime immunosuppression and the limited supply of donor tissue3. The latter concern may be addressed by recently described glucose responsive mature β-cells derived from human embryonic stem cells; called SC-β, these cells may represent an unlimited human cell source for pancreas replacement therapy4. Strategies to address the immunosuppression concern include immunoisolation of insulin-producing cells with porous biomaterials that function as an immune barrier5,6. However, clinical implementation has been challenging due to host immune responses to implant materials7. Here, we report the first long term glycemic correction of a diabetic, immune-competent animal model with human SC-β cells. SC-β cells were encapsulated with alginate-derivatives capable of mitigating foreign body responses in vivo, and implanted into the intraperitoneal (IP) space of streptozotocin-treated (STZ) C57BL/6J mice. These implants induced glycemic correction until removal at 174 days without any immunosuppression. Human C-peptide concentrations and in vivo glucose responsiveness demonstrate therapeutically relevant glycemic control. Implants retrieved after 174 days contained viable insulin-producing cells. PMID:26808346

  9. Long-Term Calorie Restriction Enhances Cellular Quality-Control Processes in Human Skeletal Muscle.

    PubMed

    Yang, Ling; Licastro, Danilo; Cava, Edda; Veronese, Nicola; Spelta, Francesco; Rizza, Wanda; Bertozzi, Beatrice; Villareal, Dennis T; Hotamisligil, Gökhan S; Holloszy, John O; Fontana, Luigi

    2016-01-26

    Calorie restriction (CR) retards aging, acts as a hormetic intervention, and increases serum corticosterone and HSP70 expression in rodents. However, less is known regarding the effects of CR on these factors in humans. Serum cortisol and molecular chaperones and autophagic proteins were measured in the skeletal muscle of subjects on CR diets for 3-15 years and in control volunteers. Serum cortisol was higher in the CR group than in age-matched sedentary and endurance athlete groups (15.6 ± 4.6 ng/dl versus 12.3 ± 3.9 ng/dl and 11.2 ± 2.7 ng/dl, respectively; p ≤ 0.001). HSP70, Grp78, beclin-1, and LC3 mRNA and/or protein levels were higher in the skeletal muscle of the CR group compared to controls. Our data indicate that CR in humans is associated with sustained rises in serum cortisol, reduced inflammation, and increases in key molecular chaperones and autophagic mediators involved in cellular protein quality control and removal of dysfunctional proteins and organelles. PMID:26774472

  10. Long term cultures of primary human hepatocytes as an alternative to drug testing in animals.

    PubMed

    Ullrich, Anett; Stolz, Donna B; Ellis, Ewa C; Strom, Stephen C; Michalopoulos, George K; Hengstler, Jan G; Runge, Dieter

    2009-01-01

    Due to species differences, primary human hepatocytes are still the in vitro system of choice to analyse liver specific processes and functions. Human hepatocytes were cultured for several weeks in a serum-free two-dimensional culture system, which was used to study the effects of acetaminophen (APAP) on hepatocellular functions and vitality. Non-invasive determinations of albumin, urea and lactate dehydrogenase concentrations in cell culture supernatants allowed continuous monitoring for at least two weeks. APAP was applied every 4 days for 24 h. Each application reduced urea production by 25% and albumin synthesis by approximately 70% without any effects on cellular viability. After removal of the substance, hepatocellular functions returned to control levels within one (urea) to three (albumin) days. The repetitive analyses of APAP-mediated effects on cellular metabolism led to identical results for up to five cycles. The drug also caused reversible and repetitive ultrastructural modifications, in particular an almost complete replacement of rough endoplasmic reticulum by smooth endoplasmic reticulum and a massive degradation of glycogen stores. The data demonstrate the suitability of the culture system to serve as a model for repetitive testing of drug-mediated changes on hepatocellular functions, thereby reducing animal studies during drug development. PMID:20383475

  11. Long-term patterns of urinary pyroglutamic acid in healthy humans.

    PubMed

    Lord, Richard S

    2016-02-01

    An investigation of human biological variation in urinary organic acids, including pyroglutamic acid along with 39 other compounds, was previously reported in which levels were determined for 8 weeks in healthy adult subjects. Here, unique, 4-week-long physiological trends for one of those compounds, pyroglutamic acid (PGA), are reported. When PGA levels for an individual rose above 40 μg/mg creatinine, 4-week downward progressions occurred until levels reached values near 15 μg/mg creatinine and the pattern was reversed when levels for an individual were below that level in the early weeks of the study. The pattern was especially prominent among 8 of the 13 menstruating female subjects suggesting a possible association with metabolic stress of the menstrual cycle. However, it also appeared in 3 of the 8 male subjects where other sources of metabolic stress may be present. The menstrual association is consistent with estrogen-mediated increase in oxidative stress. Since PGA is linked to glutathione turnover, the consistency of extreme values across all individuals displaying the pattern indicates that 15 and 40 μg/mg creatinine may represent limits that trigger shifts in sulfur amino acid metabolism. This is the first observation of approximate month-long cyclic responses in a glutathione-related urinary marker in humans. PMID:26908712

  12. Long-term neural and physiological phenotyping of a single human

    PubMed Central

    Poldrack, Russell A.; Laumann, Timothy O.; Koyejo, Oluwasanmi; Gregory, Brenda; Hover, Ashleigh; Chen, Mei-Yen; Gorgolewski, Krzysztof J.; Luci, Jeffrey; Joo, Sung Jun; Boyd, Ryan L.; Hunicke-Smith, Scott; Simpson, Zack Booth; Caven, Thomas; Sochat, Vanessa; Shine, James M.; Gordon, Evan; Snyder, Abraham Z.; Adeyemo, Babatunde; Petersen, Steven E.; Glahn, David C.; Reese Mckay, D.; Curran, Joanne E.; Göring, Harald H. H.; Carless, Melanie A.; Blangero, John; Dougherty, Robert; Leemans, Alexander; Handwerker, Daniel A.; Frick, Laurie; Marcotte, Edward M.; Mumford, Jeanette A.

    2015-01-01

    Psychiatric disorders are characterized by major fluctuations in psychological function over the course of weeks and months, but the dynamic characteristics of brain function over this timescale in healthy individuals are unknown. Here, as a proof of concept to address this question, we present the MyConnectome project. An intensive phenome-wide assessment of a single human was performed over a period of 18 months, including functional and structural brain connectivity using magnetic resonance imaging, psychological function and physical health, gene expression and metabolomics. A reproducible analysis workflow is provided, along with open access to the data and an online browser for results. We demonstrate dynamic changes in brain connectivity over the timescales of days to months, and relations between brain connectivity, gene expression and metabolites. This resource can serve as a testbed to study the joint dynamics of human brain and metabolic function over time, an approach that is critical for the development of precision medicine strategies for brain disorders. PMID:26648521

  13. Early short-term treatment with neutralizing human monoclonal antibodies halts SHIV infection in infant macaques.

    PubMed

    Hessell, Ann J; Jaworski, J Pablo; Epson, Erin; Matsuda, Kenta; Pandey, Shilpi; Kahl, Christoph; Reed, Jason; Sutton, William F; Hammond, Katherine B; Cheever, Tracy A; Barnette, Philip T; Legasse, Alfred W; Planer, Shannon; Stanton, Jeffrey J; Pegu, Amarendra; Chen, Xuejun; Wang, Keyun; Siess, Don; Burke, David; Park, Byung S; Axthelm, Michael K; Lewis, Anne; Hirsch, Vanessa M; Graham, Barney S; Mascola, John R; Sacha, Jonah B; Haigwood, Nancy L

    2016-04-01

    Prevention of mother-to-child transmission (MTCT) of HIV remains a major objective where antenatal care is not readily accessible. We tested HIV-1-specific human neutralizing monoclonal antibodies (NmAbs) as a post-exposure therapy in an infant macaque model for intrapartum MTCT. One-month-old rhesus macaques were inoculated orally with the simian-human immunodeficiency virus SHIVSF162P3. On days 1, 4, 7 and 10 after virus exposure, we injected animals subcutaneously with NmAbs and quantified systemic distribution of NmAbs in multiple tissues within 24 h after antibody administration. Replicating virus was found in multiple tissues by day 1 in animals that were not treated. All NmAb-treated macaques were free of virus in blood and tissues at 6 months after exposure. We detected no anti-SHIV T cell responses in blood or tissues at necropsy, and no virus emerged after CD8(+) T cell depletion. These results suggest that early passive immunotherapy can eliminate early viral foci and thereby prevent the establishment of viral reservoirs. PMID:26998834

  14. Localization of IL-4 and IL-4 receptors in the human term placenta, decidua and amniochorionic membranes.

    PubMed Central

    de Moraes-Pinto, M I; Vince, G S; Flanagan, B F; Hart, C A; Johnson, P M

    1997-01-01

    There has been much recent interest in cytokine expression at the materno-fetal interface. Although T-helper 2 (Th2)-type cytokines have been described in the murine feto-placental unit, few studies have as yet been performed in human pregnancy. We have examined the production of interleukin-4 (IL-4) and expression of IL-4 receptors in the human term placenta, decidua and amniochorionic membranes. Immunohistochemical analyses revealed that cytotrophoblast, decidual macrophages and both maternal and fetal endothelial cells consistently expressed IL-4, whereas syncytiotrophoblast and placental macrophages showed an inconsistent pattern between specimens. High- and low-affinity IL-4 receptors were demonstrated by immunohistochemistry at the same cellular sites as stained for IL-4, and detection of IL-4 receptors was also variable in syncytiotrophoblast. Reverse-transcribed-polymerase chain reaction (RT-PCR) analysis showed that both IL-4 and its alternative splice variant, IL-482, are produced both in placental villi and in amniochorionic and decidual tissue. Ligand-binding assays identified the presence, on isolated term syncytiotrophoblast microvillous plasma membrane vesicle preparations, of functional high-affinity binding sites for IL-4 with a Kd in the range 102-112 pM and an apparent receptor density in the range 99-102 x 10(8) sites/mg protein. Three human choriocarcinoma (BeWo, JEG-3 and Jar) and one amnion-derived (AV3) cell lines expressed IL-4 and both high- and low-affinity IL-4 receptors. The constitutive expression of both IL-4 and IL-4 receptors, together with the novel finding of the alternative splice variant IL-482 in the immediate tissues at the materno fetal interface suggest an immunobiological role for IL-4 in human pregnancy. Images Figure 1 Figure 2 Figure 3 PMID:9038717

  15. Discoidal bilayer structure of nascent high density lipoproteins from perfused rat liver.

    PubMed Central

    Hamilton, R L; Williams, M C; Fielding, C J; Havel, R J

    1976-01-01

    Rat livers were perfused for 6 h without added plasma proteins using washed erythrocytes and buffer in a recirculating system. An inhibitor to the enzyme lecithin-cholesterol acyltransferase (5,5'-dithionitrobenzoic acid) was added in some experiments to prevent modification of substrate-lipids contained in secreted lipoproteins. The inhibitor did not detectably alter hepatic ultrastructure or gas exchange, but it inhibited the secreted lecithin-cholesterol acyltransferase by more than 85%. Very low density lipoproteins in perfusate were unaltered but the high density lipoproteins obtained from livers perfused with the inhibitor appeared disk-shaped in negative stain by electron microscopy with a mean edge thickness of 46 +/- 5 A and a mean diameter of 190 +/- 25 A. The high density lipoproteins were composed predominantly of polar lipids and protein with only small amounts of cholesteryl esters and triglycerides. The major apoprotein of these discoidal fractions had the same electrophoretic mobility as the arginine-rich apoprotein, whereas plasma high density lipoproteins contained mainly the A-I approtein. In all these respects the discoidal perfusate high density lipoproteins closely resemble those found in human plasma which is deficient in lecithin-cholesterol acyltransferase. Perfusate high density lipoproteins obtained in the absence of the enzyme inhibitor more closely resembled plasma high density lipoproteins in chemical composition (content of cholesteryl esters and apoproteins) and in electron microscopic appearance. Purified lecithin-cholesterol acyltransferase synthesized cholesteryl esters at a substantially faster rate from substrate lipids of perfusate high density lipoproteins than those from plasma. The discoidal high density lipoproteins were the best substrate for this reaction. Thin sections of plasma high density lipoproteins indicated a spherical particle whereas discoidal high density lipoproteins stained with the characteristic trilaminar

  16. Simultaneous myocardial strain and dark-blood perfusion imaging using a displacement-encoded MRI pulse sequence.

    PubMed

    Le, Yuan; Stein, Ashley; Berry, Colin; Kellman, Peter; Bennett, Eric E; Taylor, Joni; Lucas, Katherine; Kopace, Rael; Chefd'Hotel, Christophe; Lorenz, Christine H; Croisille, Pierre; Wen, Han

    2010-09-01

    The purpose of this study is to develop and evaluate a displacement-encoded pulse sequence for simultaneous perfusion and strain imaging. Displacement-encoded images in two to three myocardial slices were repeatedly acquired using a single-shot pulse sequence for 3 to 4 min, which covers a bolus infusion of Gadolinium contrast. The magnitudes of the images were T(1) weighted and provided quantitative measures of perfusion, while the phase maps yielded strain measurements. In an acute coronary occlusion swine protocol (n = 9), segmental perfusion measurements were validated against microsphere reference standard with a linear regression (slope 0.986, R(2) = 0.765, Bland-Altman standard deviation = 0.15 mL/min/g). In a group of ST-elevation myocardial infarction patients (n = 11), the scan success rate was 76%. Short-term contrast washout rate and perfusion are highly correlated (R(2) = 0.72), and the pixelwise relationship between circumferential strain and perfusion was better described with a sigmoidal Hill curve than linear functions. This study demonstrates the feasibility of measuring strain and perfusion from a single set of images. PMID:20544714

  17. Hydrostatic isolated limb perfusion with adeno-associated virus vectors enhances correction of skeletal muscle in Pompe disease.

    PubMed

    Sun, B; Li, S; Bird, A; Koeberl, D D

    2010-12-01

    Glycogen storage disease type II (Pompe disease; MIM 232300) stems from the inherited deficiency of acid-α-glucosidase (GAA; acid maltase; EC 3.2.1.20), which primarily involves cardiac and skeletal muscles. We hypothesized that hydrostatic isolated limb perfusion (ILP) administration of an adeno-associated virus (AAV) vector containing a muscle-specific promoter could achieve relatively higher transgene expression in the hindlimb muscles of GAA-knockout (GAA-KO) mice, in comparison with intravenous (IV) administration. ILP administration of AAV2/8 vectors encoding alkaline phosphatase or human GAA-transduced skeletal muscles of the hindlimb widely, despite the relatively low number of vector particles administered (1 × 10¹¹), and IV administration of an equivalent vector dose failed to transduce skeletal muscle detectably. Similarly, ILP administration of fewer vector particles of the AAV2/9 vector encoding human GAA (3 × 10¹⁰) transduced skeletal muscles of the hindlimb widely and significantly reduced glycogen content to, in comparison with IV administration. The only advantage for IV administration was moderately high-level transduction of cardiac muscle, which demonstrated compellingly that ILP administration sequestered vector particles within the perfused limb. Reduction of glycogen storage in the extensor digitorum longus demonstrated the potential advantage of ILP-mediated delivery of AAV vectors in Pompe disease, because type II myofibers are resistant to enzyme replacement therapy. Thus, ILP will enhance AAV transduction of multiple skeletal muscles while reducing the required dosages in terms of vector particle numbers. PMID:20686508

  18. Influence of prostaglandins and adrenoceptor agonists on contractile activity in the human cervix at term.

    PubMed

    Bryman, I; Norström, A; Lindblom, B

    1986-04-01

    The influence of prostaglandins as well as adrenoceptor agonists and antagonists on contractile activity of isolated cervical smooth muscle from term pregnant women was studied. Prostaglandin E2 had an inhibitory effect at extremely low concentrations. Inhibition also was induced by prostaglandin F2 alpha, prostaglandin I2, and 6-keto-prostaglandin F1 alpha, but at considerably higher concentrations. Contractions evoked by noradrenaline or phenylephrine were blocked by the alpha-adrenoceptor antagonist phenoxybenzamine. The beta-adrenoceptor agonist terbutaline acted as an inhibitor, whereas isoprenaline in most cases stimulated contractile activity. The inhibitory action of prostaglandins and especially the high sensitivity to prostaglandin E2 point to a physiologic role of these compounds for cervical dilatation and retraction. A predominance of alpha-adrenoceptors might be of importance for the maintenance of cervical competence during pregnancy. PMID:2870450

  19. Long-term experiments to better understand soil-human interactions

    NASA Astrophysics Data System (ADS)

    Bormann, B. T.; Homann, P. S.

    2011-12-01

    Interactions between soils and people may be transforming global conditions, but the interactions are poorly understood. Changes in soils have proven difficult to quantify, especially in complex ecosystems manifesting large spatiotemporal variability. Long-term ecosystem experiments that evaluate soil change and demonstrate alternative choices are important to understanding changes, discovering new controls and drivers, and influencing decisions. Inspired by agriculture studies, like Rothamsted, the US Forest Service established in 1990 a network of operational-scale experiments across the Pacific Northwest to evaluate long-term effects of different forest management and disturbance regimes. With a strong experimental design, these experiments are now helping to better understand the long-term effects of managing tree harvesting (clearcutting and thinning), woody debris, and tree and understory species composition, and-serendipitously-the effects of fire. Initial results from the Southern Oregon experimental site indicate surprisingly rapid soil changes in some regimes but not others. We've also learned that rapid change presents challenges to repeat sampling. We present our sample-archive and comparable-layer approaches that seek to accommodate changes in surface elevation, aggregation and disaggregation, and mineral-soil exports. Thinning mature forest stands (80-100 yrs old) did not significantly change soil C in 11-yrs. A small upper-layer C increase was observed after thinning, but it was similar to the control. Significant increases in upper-layer soil N were observed with most treatments, but all increases were similar to the control. Leaving woody debris had little effect. The most remarkable change occurred when mature stands were clearcut and Douglas-firs were planted and tended. Associated with rapid growth of Douglas-fir, an average of 8 Mg C ha-1 was lost from weathered soil 4-18 cm deep. This contrasts with clearcuts where early-seral hardwoods and

  20. Long-term histological and immunohistochemical findings in human venous aorto-coronary bypass grafts.

    PubMed

    Ribichini, Flavio; Pugno, Francesco; Ferrero, Valeria; Wijns, William; Vacca, Giovanni; Vassanelli, Corrado; Virmani, Renu

    2008-02-01

    The aim of the present study was to analyse the long-term histology and immunohistochemistry of the plaque composition and cellular infiltration of SVGs (saphenous vein grafts) containing metallic stents. Percutaneous interventions in SVGs have a worse long-term clinical outcome compared with stenting of coronary arteries. Whether the pathological features of old degenerated SVGs condition the efficacy of drug-eluting stents is also unknown. Histology and immunohistochemistry of seven SVGs in the coronary circulation containing 12 metallic stents implanted 5 to 61 months before retrieval were analysed in patients undergoing a second aorto-coronary bypass surgery at a mean time of 11+/-6 years. The pathology of the old SVGs showed an important thrombotic and necrotic composition of the plaque, with plaque protrusion through the stent wires and a fragile media layer that could easily be damaged by stent placement with subsequent neointimal proliferation; indeed, stents with medial fracture had significantly greater mean neointimal thickness than those without (1.37+/-0.68 compared with 0.81+/-0.47 mm(2); P<0.02). Neointimal inflammatory cell density correlated with increased neointimal thickness in patent vessels (r(2)=0.43, P<0.001). Immunostaining showed the total absence of ERs (oestrogen receptors), a poor cellular proliferative state as indicated by the presence of the Ki-67 marker, and persistent inflammation close to the stent wires as revealed by KP-1 and ACE (angiotensin-converting enzyme) immunostaining in most inflammatory cells in contact with the metal. These pathological findings may contribute to the more severe progression of disease and worse clinical outcome observed after conventional stented angioplasty of SVGs and might also interfere with the efficacy of drug-eluting stents in this specific atherosclerotic milieu. PMID:17848140

  1. Long-term studies of urease-induced crystallization in human urine.

    PubMed

    Edin-Liljegren, A; Grenabo, L; Hedelin, H; Pettersson, S; Wang, Y H

    1994-07-01

    Urine samples were inoculated with viable Proteus mirabilis or purified Jack bean urease. The subsequent pH increase and crystallization were followed for 2 weeks. Particle formation was detected much earlier and at a lower pH in urines inoculated with Proteus, in which a higher end pH was also reached. The crystal configuration in bacteria and urease inoculated samples was different. Crystal aggregation was also much more pronounced in the Proteus mirabilis inoculated samples. The total precipitation was markedly increased in the Proteus mirabilis inoculated samples. The presence of live Proteus mirabilis thus has a profound influence on urease-induced crystallization in human urine. Despite the formation of rather large crystal aggregates in the Proteus-inoculated urines, no firm aggregates of a "prestone" type were observed. PMID:8201667

  2. Long-term maintenance of human induced pluripotent stem cells by automated cell culture system.

    PubMed

    Konagaya, Shuhei; Ando, Takeshi; Yamauchi, Toshiaki; Suemori, Hirofumi; Iwata, Hiroo

    2015-01-01

    Pluripotent stem cells, such as embryonic stem cells and induced pluripotent stem (iPS) cells, are regarded as new sources for cell replacement therapy. These cells can unlimitedly expand under undifferentiated conditions and be differentiated into multiple cell types. Automated culture systems enable the large-scale production of cells. In addition to reducing the time and effort of researchers, an automated culture system improves the reproducibility of cell cultures. In the present study, we newly designed a fully automated cell culture system for human iPS maintenance. Using an automated culture system, hiPS cells maintained their undifferentiated state for 60 days. Automatically prepared hiPS cells had a potency of differentiation into three germ layer cells including dopaminergic neurons and pancreatic cells. PMID:26573336

  3. Clinical Neuroimaging Using Arterial Spin-Labeled Perfusion MRI

    PubMed Central

    Wolf, Ronald L.; Detre, John A.

    2007-01-01

    SUMMARY The two most common methods for measuring perfusion with MRI are based on dynamic susceptibility contrast (DSC) and arterial spin labeling (ASL). Although clinical experience to date is much more extensive with DSC perfusion MRI, ASL methods offer several advantages. The primary advantages are that completely noninvasive absolute cerebral blood flow (CBF) measurements are possible with relative insensitivity to permeability, and that multiple repeated measurements can be obtained to evaluate one or more interventions or to perform perfusion-based functional MRI. ASL perfusion and perfusion-based fMRI methods have been applied in many clinical settings, including acute and chronic cerebrovascular disease, CNS neoplasms, epilepsy, aging and development, neurodegenerative disorders, and neuropsychiatric diseases. Recent technical advances have improved the sensitivity of ASL perfusion MRI, and increasing use is expected in the coming years. This review focuses on ASL perfusion MRI and applications in clinical neuroimaging. PMID:17599701

  4. Multi-modality imaging for the assessment of myocardial perfusion with emphasis on stress perfusion CT and MR imaging.

    PubMed

    Ko, Sung Min; Hwang, Hweung Kon; Kim, Sung Mok; Cho, Ihn Ho

    2015-06-01

    High-quality and non-invasive diagnostic tools for assessing myocardial ischemia are necessary for therapeutic decisions regarding coronary artery disease. Myocardial perfusion has been studied using myocardial contrast echo perfusion, single-photon emission computed tomography, positron emission tomography, cardiovascular magnetic resonance, and, more recently, computed tomography. The addition of coronary computed tomography angiography to myocardial perfusion imaging improves the specificity and overall diagnostic accuracy of detecting the hemodynamic significance of coronary artery stenosis. This study reviews the benefits, limitations, and imaging findings of various imaging modalities for assessing myocardial perfusion, with particular emphasis on stress perfusion computed tomography and cardiovascular magnetic resonance imaging. PMID:25809387

  5. Phenotypic and Functional Characterization of Mesenchymal Stem/Multipotent Stromal Cells from Decidua Basalis of Human Term Placenta

    PubMed Central

    Abomaray, F. M.; Al Jumah, M. A.; Alsaad, K. O.; Jawdat, D.; Al Khaldi, A.; AlAskar, A. S.; Al Harthy, S.; Al Subayyil, A. M.; Khatlani, T.; Alawad, A. O.; Alkushi, A.; Kalionis, B.; Abumaree, M. H.

    2016-01-01

    Mesenchymal stem cell (MSC) therapies for the treatment of diseases associated with inflammation and oxidative stress employ primarily bone marrow MSCs (BMMSCs) and other MSC types such as MSC from the chorionic villi of human term placentae (pMSCs). These MSCs are not derived from microenvironments associated with inflammation and oxidative stress, unlike MSCs from the decidua basalis of the human term placenta (DBMSCs). DBMSCs were isolated and then extensively characterized. Differentiation of DBMSCs into three mesenchymal lineages (adipocytes, osteocytes, and chondrocytes) was performed. Real-time polymerase chain reaction (PCR) and flow cytometry techniques were also used to characterize the gene and protein expression profiles of DBMSCs, respectively. In addition, sandwich enzyme-linked immunosorbent assay (ELISA) was performed to detect proteins secreted by DBMSCs. Finally, the migration and proliferation abilities of DBMSCs were also determined. DBMSCs were positive for MSC markers and HLA-ABC. DBMSCs were negative for hematopoietic and endothelial markers, costimulatory molecules, and HLA-DR. Functionally, DBMSCs differentiated into three mesenchymal lineages, proliferated, and migrated in response to a number of stimuli. Most importantly, these cells express and secrete a distinct combination of cytokines, growth factors, and immune molecules that reflect their unique microenvironment. Therefore, DBMSCs could be attractive, alternative candidates for MSC-based therapies that treat diseases associated with inflammation and oxidative stress. PMID:27087815

  6. Detection of bovine alpha-S1-casein in term and preterm human colostrum with proteomic techniques.

    PubMed

    Orru, S; Di Nicola, P; Giuliani, F; Fabris, C; Conti, A; Coscia, A; Bertino, E

    2013-01-01

    Due to increased social awareness of allergens and population hyper-sensitization, the reported incidence of allergic reactions to food allergens has increased over the past two decades. Cow's milk proteins (CMPs) are among the most common food allergens. The aim of this study was to use proteomics techniques to investigate cow's milk allergens in both full-term human colostrum and in preterm newborns mothers where both groups showed no prior allergen detection -- in order to understand whether cows milk allergens could be a cause of sensitization established through lactation. The most relevant finding was the detection of the intact bovine alpha-S1-casein in both term and preterm colostrum. Using techniques detailed in this paper and which allowed for direct protein identification, beta-lactoglobulin was not detected in any of the colostrum samples. According to our results, bovine alpha 1 casein is considered a major cow's milk allergen, is readily secreted in human milk, and so could be considered a possible cause of sensitization in exclusively breastfed infants. PMID:23755758

  7. Micropatterning Facilitates the Long-Term Growth and Analysis of iPSC-Derived Individual Human Neurons and Neuronal Networks.

    PubMed

    Burbulla, Lena F; Beaumont, Kristin G; Mrksich, Milan; Krainc, Dimitri

    2016-08-01

    The discovery of induced pluripotent stem cells (iPSCs) and their application to patient-specific disease models offers new opportunities for studying the pathophysiology of neurological disorders. However, current methods for culturing iPSC-derived neuronal cells result in clustering of neurons, which precludes the analysis of individual neurons and defined neuronal networks. To address this challenge, cultures of human neurons on micropatterned surfaces are developed that promote neuronal survival over extended periods of time. This approach facilitates studies of neuronal development, cellular trafficking, and related mechanisms that require assessment of individual neurons and specific network connections. Importantly, micropatterns support the long-term stability of cultured neurons, which enables time-dependent analysis of cellular processes in living neurons. The approach described in this paper allows mechanistic studies of human neurons, both in terms of normal neuronal development and function, as well as time-dependent pathological processes, and provides a platform for testing of new therapeutics in neuropsychiatric disorders. PMID:27108930

  8. Mechanistic Effects of Long-Term Ultraviolet B Irradiation Induce Epidermal and Dermal Changes in Human Skin Xenografts

    PubMed Central

    Hachiya, Akira; Sriwiriyanont, Penkanok; Fujimura, Tsutomu; Ohuchi, Atsushi; Kitahara, Takashi; Takema, Yoshinori; Kitzmiller, William J.; Visscher, Marty O.; Tsuboi, Ryoji; Boissy, Raymond E.

    2009-01-01

    UVB irradiation has been reported to induce photoaging and suppress systemic immune function that could lead to photocarcinogenesis. However, because of the paucity of an UVB-induced photodamaged skin model, precise and temporal mechanism(s) underlying the deleterious effects of long-term UVB exposure on human skin have yet to be delineated. In this study, we established a model using human skin xenografted onto severe combined immunodeficient mice, which were subsequently challenged by repeated UVB irradiation for 6 weeks. Three-dimensional optical image analysis of skin replicas and noninvasive biophysical measurements illustrated a significant increase in skin surface roughness, similar to premature photoaging, and a significant loss of skin elasticity after long-term UVB exposure. Resembling authentically aged skin, UVB-exposed samples exhibited significant increases in epithelial keratins (K6, K16, K17), elastins, and matrix metalloproteinases (MMP-1, MMP-9, MMP-12) as well as degradation of collagens (I, IV, VII). The UVB-induced deterioration of fibrous keratin intermediate filaments was also observed in the stratum corneum. Additionally, similarities in gene expression patterns between our model and chronologically aged skin substantiated the plausible relationship between photodamage and chronological age. Furthermore, severe skin photodamage was observed when neutralizing antibodies against TIMP-1, an endogenous inhibitor of MMPs, were administered during the UVB exposure regimen. Taken together, these findings suggest that our skin xenograft model recapitulates premature photoaged skin and provides a comprehensive tool with which to assess the deleterious effects of UVB irradiation. PMID:19147832

  9. Hypermethylation of gene promoters in peripheral blood leukocytes in humans long term after radiation exposure.

    PubMed

    Kuzmina, Nina S; Lapteva, Nellya Sh; Rubanovich, Alexander V

    2016-04-01

    Some human genes known to undergo age-related promoter hypermethylation. These epigenetic modifications are similar to those occurring in the course of certain diseases, e.g. some types of cancer, which in turn may also associate with age. Given external genotoxic factors may additionally contribute to hypermethylation, this study was designed to analyzes, using methylation-sensitive polymerase chain reaction (PCR), the CpG island hypermethylation in RASSF1A, CDKN2A (including p16/INK4A and p14/ARF) and GSTP1 promoters in peripheral blood leukocytes of individuals exposed to ionizing radiation long time ago. One hundred and twenty-four irradiated subjects (24-77 years old at sampling: 83 Chernobyl Nuclear Power Plant clean-up workers, 21 nuclear workers, 20 residents of territories with radioactive contamination) and 208 unirradiated volunteers (19-77 years old at sampling) were enrolled. In addition, 74 non-exposed offspring (2-51 years old at sampling) born to irradiated parents were examined. The frequency of individuals displaying promoter methylation of at least one gene in exposed group was significantly higher as compared to the control group (OR=5.44, 95% CI=2.62-11.76, p=3.9×10(-7)). No significant difference was found between the frequency of subjects with the revealed promoter methylation in the group of offspring born to irradiated parents and in the control group. The increase in the number of methylated loci of RASSF1A and p14/ARF was associated with age (β=0.242; p=1.7×10(-5)). In contrast, hypermethylation of p16/INK4A and GSTP1 genes correlated with the fact of radiation exposure only (β=0.290; p=1.7×10(-7)). The latter finding demonstrates that methylation changes in blood leukocytes of healthy subjects exposed to radiation resemble those reported in human malignancies. Additional studies are required to identify the dose-response of epigenetic markers specifically associating with radiation-induced premature aging and/or with the development

  10. Biomedical Analyses of Mice Body Hair Exposed to Long-term Space Flight as a Compliment of Human Research

    NASA Astrophysics Data System (ADS)

    Mukai, Chiaki

    Introduction: To understand the effect of space environment characterized by microgravity and radiation on protein and mineral metabolisms is important for developing the countermeasures to the adverse effects happening on the astronauts who stay long-term in space. Thus JAXA has started a human research to study the effects of long-term exposure in space flight on gene expression and mineral metabolism by analyzing astronaut's hair grown in space since December 2009 (Experiment nicknamed "HAIR"). Ten human subjects who are the crew of the International Space Station (ISS) will be expected to complete this experiment. Thanks to the tissue sharing program of space-flown mice which is presented and organized by AGI(Italian Space Agency), we can also have an opportunity to analyze rodents samples which will greatly compliment human hair experiment by enable us to conduct more detailed analysis with the expansion of skin analysis which is not include in human experiment. The purpose of this flown-mice experiment is to study the effects of long-term exposure to space environment such as microgravity and space radiation on mineral and protein metabolism, the biological responses to the stress levels, and the initial process of skin carcinogenesis by analyzing hair shaft, its root cells, and skin. Approach and Method In this experiment, we analyzed hair shaft, hair root and skin. Hair samples with skin were taken from 3-month space-flown mice and ground-control mice in the AGI's tissue sharing program in 2009. The sample numbers of space-flown mice and control-mice were three and six, respectively. And they were at the Mice Drawer System (MDS) in ISS and in the laboratory of Geneva University. For the hair shaft, the mineral balance is investi-gated by energy dispersive X-ray spectroscopy (SEM-EDX). For hair root, the extracted RNA undergoes DNA microarray analysis, and will be further examined particular interests of gene-expression by real time Reverse Transcription

  11. Microgravity alters respiratory sinus arrhythmia and short-term heart rate variability in humans

    NASA Technical Reports Server (NTRS)

    Migeotte, P-F; Prisk, G. Kim; Paiva, M.; West, J. B. (Principal Investigator)

    2003-01-01

    We studied heart rate (HR), heart rate variability (HRV), and respiratory sinus arrhythmia (RSA) in four male subjects before, during, and after 16 days of spaceflight. The electrocardiogram and respiration were recorded during two periods of 4 min controlled breathing at 7.5 and 15 breaths/min in standing and supine postures on the ground and in microgravity. Low (LF)- and high (HF)-frequency components of the short-term HRV (< or =3 min) were computed through Fourier spectral analysis of the R-R intervals. Early in microgravity, HR was decreased compared with both standing and supine positions and had returned to the supine value by the end of the flight. In microgravity, overall variability, the LF-to-HF ratio, and RSA amplitude and phase were similar to preflight supine values. Immediately postflight, HR increased by approximately 15% and remained elevated 15 days after landing. LF/HF was increased, suggesting an increased sympathetic control of HR standing. The overall variability and RSA amplitude in supine decreased postflight, suggesting that vagal tone decreased, which coupled with the decrease in RSA phase shift suggests that this was the result of an adaptation of autonomic control of HR to microgravity. In addition, these alterations persisted for at least 15 days after return to normal gravity (1G).

  12. No short-term effects of digital mobile radio telephone on the awake human electroencephalogram

    SciTech Connect

    Roeschke, J.; Mann, K.

    1997-05-01

    A recent study reported the results of an exploratory study of alterations of the quantitative sleep profile due to the effects of a digital mobile radio telephone. Rapid eye movement (REM) was suppressed, and the spectral power density in the 8--13 Hz frequency range during REM sleep was altered. The aim of the present study was to illuminate the influence of digital mobile radio telephone on the awake electroencephalogram (EEG) of healthy subjects. For this purpose, the authors investigated 34 male subjects in a single-blind cross-over design experiment by measuring spontaneous EEGs under closed-eyes condition from scalp positions C{sub 3} and C{sub 4} and comparing the effects of an active and an inactive digital mobile radio telephone (GSM) system. During exposure of nearly 3.5 min to the 900 MHz electromagnetic field pulsed at a frequency of 217 Hz and with a pulse width of 580 {micro}s, the authors could not detect any difference in the awake EEGs in terms of spectral power density measures.

  13. Anococcygeal Raphe Revisited: A Histological Study Using Mid-Term Human Fetuses and Elderly Cadavers

    PubMed Central

    Arakawa, Takashi; Abe, Hiroshi; Abe, Shinichi; Cho, Baik Hwan; Murakami, Gen; Sugihara, Kenichi

    2012-01-01

    Purpose We recently demonstrated the morphology of the anococcygeal ligament. As the anococcygeal ligament and raphe are often confused, the concept of the anococcygeal raphe needs to be re-examined from the perspective of fetal development, as well as in terms of adult morphology. Materials and Methods We examined the horizontal sections of 15 fetuses as well as adult histology. From cadavers, we obtained an almost cubic tissue mass containing the dorsal wall of the anorectum, the coccyx and the covering skin. Most sections were stained with hematoxylin and eosin or Masson-trichrome solution. Results The adult ligament contained both smooth and striated muscle fibers. A similar band-like structure was seen in fetuses, containing: 1) smooth muscle fibers originating from the longitudinal muscle coat of the anal canal and 2) striated muscle fibers from the external anal sphincter (EAS). However, in fetuses, the levator ani muscle did not attach to either the band or the coccyx. Along and around the anococcygeal ligament, we did not find any aponeurotic tissue with transversely oriented fibers connecting bilateral levator ani slings. Instead, in adults, a fibrous tissue mass was located at a gap between bilateral levator ani slings; this site corresponded to the dorsal side of the ligament and the EAS in the immediately deep side of the natal skin cleft. Conclusion We hypothesize that a classically described raphe corresponds to the specific subcutaneous tissue on the superficial or dorsal side of the anococcygeal ligament. PMID:22665356

  14. High-dose short-term administration of naringin did not alter talinolol pharmacokinetics in humans.

    PubMed

    Nguyen, M A; Staubach, P; Tamai, I; Langguth, P

    2015-02-20

    Naringin is considered the major causative ingredient of the inhibition of intestinal drug uptake by grapefruit juice. Moreover, it is contained in highly dosed nutraceuticals available on the market. A controlled, open, randomized, crossover study was performed in 10 healthy volunteers to investigate the effect of high-dose naringin on the bioavailability of talinolol, a substrate of intestinal organic anion-transporting polypeptide (OATP)-mediated uptake. Following 6-day supplementation with 3 capsules of 350 mg naringin daily, 100mg talinolol were administered orally with 3 capsules of the same dietary supplement (1050 mg naringin) on the seventh day. This test treatment was compared to 100mg talinolol only (control). The results showed that short-term high-dose naringin supplementation did not significantly affect talinolol pharmacokinetics. Geometric mean ratios of test versus control ranged between 0.90 and 0.98 for talinolol c(max), AUC(0-48 h), AUC(0-∞), t(1/2) and A(e(0-48 h)). The high dose may provoke inhibition of the efflux transporter P-glycoprotein (P-gp) which counteracts the uptake inhibition. As disintegration and dissolution processes are required for the solid dosage form, dissolved naringin may arrive at the site of interaction after talinolol is already absorbed. In conclusion, the effect of nutraceuticals on drug pharmacokinetics can deviate from that observed when administered as food component due to the different dose and dosage form. PMID:25486333

  15. Treatment of anal human papillomavirus-associated disease: a long term outcome study.

    PubMed

    Nathan, M; Hickey, N; Mayuranathan, L; Vowler, S L; Singh, N

    2008-07-01

    Treatment for human papillomavirus (HPV)-associated anal canal disease has been unsatisfactory. The objective of our study was to determine the treatment outcome in our cohort with anal HPV disease. Overall, 181 patients were evaluated over a median period of 19.1 months (range = 2.8-125.5). Eighty-eight patients (48.6%) with high-grade anal intraepithelial neoplasia (AIN) and 82 patients (45.3%) with low-grade AIN underwent treatment. One hundred and forty-one patients (77.9%) received laser ablative treatment as an outpatient procedure. The treatment yielded cure, defined as a disease-free state at 12 months after treatment, in 63.0% (114/181). Median time to cure for the cohort was 31.5 months (95% confidence interval: 23.0-40.0). Treatment outcome showed no evidence of being affected by age, sexual preference, history of smoking or presence of high-grade disease. Median time to cure was significantly affected by a positive HIV status (P = 0.02) and the extent (volume) of the disease (P = 0.01). Contrary to the current view that treatment of HPV-related anal disease is difficult, unrewarding due to recurrences and may lead to substantial morbidity, we demonstrate that effective treatment is possible for both low- and high-grade AIN. These findings should help with the general desire to introduce screening for AIN for at-risk groups. PMID:18574114

  16. Luminal perfusion of isolated gastric glands.

    PubMed

    Waisbren, S J; Geibel, J; Boron, W F; Modlin, I M

    1994-04-01

    We have extended to rabbit gastric glands the technique for perfusing single isolated renal tubules. We isolated glands by hand dissection and used concentric glass pipettes to hold them and perfuse their lumina. Parietal cells (PCs), which tended to be located toward the gland opening, were identified by their pyramidal shape, large size, and autofluorescence. Chief cells (CCs) were identified by their round shape and smaller size. In some experiments, we perfused the lumen with hydroxypyrenetrisulfonate, a pH-sensitive fluorophore, at pH 7.4 and used digital image processing to monitor luminal pH (pH1). Solutions were buffered with N-2-hydroxyethylpiperazine-N'-2-ethanesulfonic acid to pH 7.4 at 37 degrees C. With fast perfusion, we found no evidence of decreased pH1, even with stimulation by 10 microM carbachol. With slow perfusion, pH1 often fell below the dye's sensitive range (pH < 5), especially at low perfusate buffering power. In other experiments, we loaded cells with the pH-sensitive dye 2',7'-bis(2-carboxyethyl)-5(6)-carboxyfluorescein and monitored intracellular pH (pHi) in multiple individual PCs and CCs in a single gland. Mean pHi was 7.21 +/- 0.02 (n = 136 cells) for PCs and 7.27 +/- 0.03 (n = 103) for CCs. To examine the response to decreased pH1 and basolateral pH (pHb), we lowered pHb to 6.4 or lowered pH1 to 3.4 or 1.4. Lowering pHb to 6.4 for approximately 1 min caused pHi to fall reversibly by 0.39 +/- 0.05 (n = 53) in PCs and 0.58 +/- 0.03 (n = 50) in CCs. Lowering pH1 to 3.4 or 1.4 caused no significant pHi changes in PCs (n = 38 and 82) or in CCs (n = 44 and 77). Carbachol did not affect the response to changes in pH1 or pHb. We conclude that the apical surfaces of PCs and CCs are unusually resistant to extreme pH gradients. PMID:8178950

  17. A surface-based analysis of hemispheric asymmetries and folding of cerebral cortex in term-born human infants

    PubMed Central

    Hill, Jason; Dierker, Donna; Neil, Jeffrey; Inder, Terrie; Knutsen, Andrew; Harwell, John; Coalson, Timothy; Van Essen, David

    2010-01-01

    We have established a population average surface based atlas of human cerebral cortex at term gestation and used it to compare infant and adult cortical shape characteristics. Accurate cortical surface reconstructions for each hemisphere of 12 healthy term gestation infants were generated from structural magnetic resonance imaging data using a novel segmentation algorithm. Each surface was inflated, flattened, mapped to a standard spherical configuration, and registered to a target atlas sphere that reflected shape characteristics of all 24 contributing hemispheres using landmark constrained surface registration. Population average maps of sulcal depth, depth variability, 3-dimensional positional variability, and hemispheric depth asymmetry were generated and compared to previously established maps of adult cortex. We found that cortical structure in term infants is similar to the adult in many respects, including the pattern of individual variability and the presence of statistically significant structural asymmetries in lateral temporal cortex, including the planum temporale and superior temporal sulcus. These results indicate that several features of cortical shape are minimally influenced by the postnatal environment. PMID:20147553

  18. Effect of Short-Term Thyroxine Administration on Energy Metabolism and Mitochondrial Efficiency in Humans

    PubMed Central

    Johannsen, Darcy L.; Galgani, Jose E.; Johannsen, Neil M.; Zhang, Zhengyu; Covington, Jeffrey D.; Ravussin, Eric

    2012-01-01

    The physiologic effects of triiodothyronine (T3) on metabolic rate are well-documented; however, the effects of thyroxine (T4) are less clear despite its wide-spread use to treat thyroid-related disorders and other non-thyroidal conditions. Here, we investigated the effects of acute (3-day) T4 supplementation on energy expenditure at rest and during incremental exercise. Furthermore, we used a combination of in situ and in vitro approaches to measure skeletal muscle metabolism before and after T4 treatment. Ten healthy, euthyroid males were given 200 µg T4 (levothyroxine) per day for 3 days. Energy expenditure was measured at rest and during exercise by indirect calorimetry, and skeletal muscle mitochondrial function was assessed by in situ ATP flux (31P MRS) and in vitro respiratory control ratio (RCR, state 3/state 4 rate of oxygen uptake using a Clark-type electrode) before and after acute T4 treatment. Thyroxine had a subtle effect on resting metabolic rate, increasing it by 4% (p = 0.059) without a change in resting ATP demand (i.e., ATP flux) of the vastus lateralis. Exercise efficiency did not change with T4 treatment. The maximal capacity to produce ATP (state 3 respiration) and the coupled state of the mitochondria (RCR) were reduced by approximately 30% with T4 (p = 0.057 and p = 0.04, respectively). Together, the results suggest that T4, although less metabolically active than T3, reduces skeletal muscle efficiency and modestly increases resting metabolism even after short-term supplementation. Our findings may be clinically relevant given the expanding application of T4 to treat non-thyroidal conditions such as obesity and weight loss. PMID:22844412

  19. Trends in human reproductive wastage in relation to long-term practice of inbreeding.

    PubMed

    Rao, P S; Inbaraj, S G

    1979-01-01

    The trends in reproductive performance and wastage are studied in relation to consanguinity of marriage and age of women on a population sample of 20,626 women, from the rural and urban areas of North Arcot District in South India. Data were collected by qualified women investigators using intensive interveiw techniques and specially developed questionnaires. Adequate quality control mechanisms were set up to ensure reliability of information gathered. For each marriage, a family pedigree was drawn extending upwards to two early generations on the side of each spouse in order to determine the existence and type of consanguinity married, 80% or more of such between an uncle and a niece or between first cousins. Altogher 70 161 total pregnancies were recorded for the 20,626 women. The differences between consanguineous and non-consanguineous marriages in terms of total foetal loss, perinatal, neonatal, postneonatl and infant mortality rates showed only marginal differences that attain statistical significance only because of the large sample size involved. No consistent relationships were observed between the degree of consanguinity and these reproductive losses. These actual differences were more marked in the older age-groups of women and declined to rather insignificant proportions as the age groups became younger. Taking into consideration the various socio-demographic factors, the narrowing differentials in the reproductive wastage between consanguineous and non-consanguineous marriages from the oldest to the youngest women confirm the tapering effects of continued inbreeding practices on the reproductive wastage. Further studies on these lines are still in progress. PMID:434781

  20. Human neonatal hepatocyte transplantation induces long-term rescue of unconjugated hyperbilirubinemia in the Gunn rat.

    PubMed

    Tolosa, Laia; López, Silvia; Pareja, Eugenia; Donato, María Teresa; Myara, Anne; Nguyen, Tuan Huy; Castell, José Vicente; Gómez-Lechón, María José

    2015-06-01

    Crigler-Najjar type 1 disease is a rare inherited metabolic disease characterized by high levels of unconjugated bilirubin due to the complete absence of hepatic uridine diphosphoglucuronate-glucuronosyltransferase activity. Hepatocyte transplantation (HT) has been proposed as an alternative treatment for Crigler-Najjar syndrome, but it is still limited by the quality and the low engraftment and repopulation ability of the cells used. Because of their attachment capability and expression of adhesion molecules as well as the higher proportion of hepatic progenitor cells, neonatal hepatocytes may have an advantage over adult cells. Adult or neonatal hepatocytes were transplanted into Gunn rats, a model for Crigler-Najjar disease. Engraftment and repopulation were studied and compared by immunofluorescence (IF). Additionally, the serum bilirubin levels, the presence of bilirubin conjugates in rat serum, and the expression of uridine diphosphate glucuronosyltransferase 1 family polypeptide A1 (UGT1A1) in rat liver samples were also analyzed. Here we show that neonatal HT results in long-term correction in Gunn rats. In comparison with adult cells, neonatal cells showed better engraftment and repopulation capability 3 days and 6 months after transplantation, respectively. Bilirubinemia decreased in the transplanted animals during the whole experimental follow-up (6 months). Bilirubin conjugates were also present in the serum of the transplanted animals. Western blots and IF confirmed the presence and expression of UGT1A1 in the liver. This work is the first to demonstrate the advantage of using neonatal hepatocytes for the treatment of Crigler-Najjar in vivo. PMID:25821167

  1. Plasticity in the adult human auditory brainstem following short-term linguistic training

    PubMed Central

    Song, Judy H.; Skoe, Erika; Wong, Patrick C. M.; Kraus, Nina

    2009-01-01

    Peripheral and central structures along the auditory pathway contribute to speech processing and learning. However, because speech requires the use of functionally and acoustically complex sounds which necessitates high sensory and cognitive demands, long-term exposure and experience using these sounds is often attributed to the neocortex with little emphasis placed on subcortical structures. The present study examines changes in the auditory brainstem, specifically the frequency following response (FFR), as native English-speaking adults learn to incorporate foreign speech sounds (lexical pitch patterns) in word identification. The FFR presumably originates from the auditory midbrain, and can be elicited pre-attentively. We measured FFRs to the trained pitch patterns before and after training. Measures of pitch-tracking were then derived from the FFR signals. We found increased accuracy in pitch-tracking after training, including a decrease in the number of pitch-tracking errors and a refinement in the energy devoted to encoding pitch. Most interestingly, this change in pitch-tracking accuracy only occurred in the most acoustically complex pitch contour (dipping contour), which is also the least familiar to our English-speaking subjects. These results not only demonstrate the contribution of the brainstem in language learning and its plasticity in adulthood, but they also demonstrate the specificity of this contribution (i.e., changes in encoding only occurs in specific, least familiar stimuli, not all stimuli). Our findings complement existing data showing cortical changes after second language learning, and are consistent with models suggesting that brainstem changes resulting from perceptual learning are most apparent when acuity in encoding is most needed. PMID:18370594

  2. Fluid volume control during short-term space flight and implications for human performance.

    PubMed

    Watenpaugh, D E

    2001-09-01

    Space flight exerts substantial effects on fluid volume control in humans. Cardiac distension occurs during the first 1-2 days of space flight relative to supine and especially upright 1g conditions. Plasma volume contraction occurs quickly in microgravity, probably as a result of transcapillary fluid filtration into upper-body interstitial spaces. No natriuresis or diuresis has been observed in microgravity, such that diuresis cannot explain microgravity-induced hypovolemia. Reduction of fluid intake occurs irrespective of space motion sickness and leads to hypovolemia. The fourfold elevation of urinary antidiuretic hormone (ADH) levels on flight day 1 probably results from acceleration exposures and other stresses of launch. Nevertheless, it is fascinating that elevated ADH levels and reduced fluid intake occur simultaneously early in flight. Extracellular fluid volume decreases by 10-15% in microgravity, and intracellular fluid volume appears to increase. Total red blood cell mass decreases by approximately 10% within 1 week in space. Inflight Na(+) and volume excretory responses to saline infusion are approximately half those seen in pre-flight supine conditions. Fluid volume acclimation to microgravity sets the central circulation to homeostatic conditions similar to those found in an upright sitting posture on Earth. Fluid loss in space contributes to reduced exercise performance upon return to 1g, although not necessarily in flight. In-flight exercise training may help prevent microgravity-induced losses of fluid and, therefore, preserve the capacity for upright exercise post-flight. Protection of orthostatic tolerance during space flight probably requires stimulation of orthostatic blood pressure control systems in addition to fluid maintenance or replacement. PMID:11581336

  3. Plasma cholesterol synthesis using deuterated water in humans: effect of short-term food restriction

    SciTech Connect

    Jones, P.J.; Scanu, A.M.; Schoeller, D.A.

    1988-06-01

    Our purpose was to develop methods in humans to determine the fractional synthetic rate (FSR) of plasma pool free cholesterol using the rate of deuterium incorporation from body water. The sensitivity of this method was examined by measuring FSR after periods of fasting and feeding. Five healthy men with normal lipoprotein levels were given a prepared diet containing 40% of calories as fat and a polyunsaturated/saturated fatty acid ratio of 0.25 for 8 days, except for day 7 when they were given only drinking water. Beginning after the supper meal on day 6, they received no food until 8 AM on day 8 when they consumed meals as normal. Over days 7 and 8 the subjects were given prime and constant deuterium oxide orally to maintain body water deuterium enrichment at about 0.05 atom % excess. Plasma samples were obtained at 0 hours (day 7, 8 AM) and at 12, 24, 36, and 48 hours thereafter. Free cholesterol was extracted, purified by thin-layer chromatography, and combusted to water. The water was reduced to H/sub 2/ and analyzed for deuterium enrichment by isotope ratio mass spectrometry. Analytic precision of this system was determined as 3.5 0/00 (parts per mil) vs Standard Mean Ocean Water. Deuterium enrichment of plasma water for the group during the 48-hour deuterium oxide administration period was 3143 0/00 +/- 310 0/00 (mean +/- SEM). Cholesterol deuterium enrichment for the group during the 12-hour period of fasting (10.9 0/00 +/- 4.1 0/00) was not different from that during feeding (14.2 0/00 +/- 6.2 0/00).

  4. Emergence of stable functional networks in long-term human EEG

    PubMed Central

    Chu-Shore, Catherine J.; Kramer, Mark A.; Pathmanathan, Jay; Bianchi, Matt T.; Westover, M. Brandon; Wizon, Lauren; Cash, Sydney S.

    2012-01-01

    Functional connectivity networks have become a central focus in neuroscience as they reveal key higher dimensional features of normal and abnormal nervous system physiology. Functional networks reflect activity-based coupling between brain regions that may be constrained by relatively static anatomical connections, yet these networks appear to support tremendously dynamic behaviors. Within this growing field, the stability and temporal characteristics of functional connectivity brain networks have not been well characterized. We evaluated the temporal stability of spontaneous functional connectivity networks derived from multi-day scalp encephalogram (EEG) recordings in five healthy human subjects. Topological stability and graph characteristics of networks derived from averaged data epochs ranging from one second to multiple hours across different states of consciousness were compared. We show that although functional networks are highly variable on the order of seconds, stable network templates emerge after as little as ~100s of recording and persist across different states and frequency bands (albeit with slightly different characteristics in different states and frequencies). Within these network templates, the most common edges are markedly consistent, constituting a network “core”. Although average network topologies persist across time, measures of global network connectivity, density and clustering coefficient, are state- and frequency- specific, with sparsest but most highly clustered networks seen during sleep and in the gamma frequency band. These findings support the notion that a core functional organization underlies spontaneous cortical processing and may provide a reference template upon which unstable, transient, and rapidly adaptive long-range assemblies are overlaid in a frequency dependent manner. PMID:22357854

  5. Emergence of stable functional networks in long-term human electroencephalography.

    PubMed

    Chu, Catherine J; Kramer, Mark A; Pathmanathan, Jay; Bianchi, Matt T; Westover, M Brandon; Wizon, Lauren; Cash, Sydney S

    2012-02-22

    Functional connectivity networks have become a central focus in neuroscience because they reveal key higher-dimensional features of normal and abnormal nervous system physiology. Functional networks reflect activity-based coupling between brain regions that may be constrained by relatively static anatomical connections, yet these networks appear to support tremendously dynamic behaviors. Within this growing field, the stability and temporal characteristics of functional connectivity brain networks have not been well characterized. We evaluated the temporal stability of spontaneous functional connectivity networks derived from multi-day scalp encephalogram (EEG) recordings in five healthy human subjects. Topological stability and graph characteristics of networks derived from averaged data epochs ranging from 1 s to multiple hours across different states of consciousness were compared. We show that, although functional networks are highly variable on the order of seconds, stable network templates emerge after as little as ∼100 s of recording and persist across different states and frequency bands (albeit with slightly different characteristics in different states and frequencies). Within these network templates, the most common edges are markedly consistent, constituting a network "core." Although average network topologies persist across time, measures of global network connectivity, density and clustering coefficient, are state and frequency specific, with sparsest but most highly clustered networks seen during sleep and in the gamma frequency band. These findings support the notion that a core functional organization underlies spontaneous cortical processing and may provide a reference template on which unstable, transient, and rapidly adaptive long-range assemblies are overlaid in a frequency-dependent manner. PMID:22357854

  6. Long-Term Green Tea Supplementation Does Not Change the Human Gut Microbiota

    PubMed Central

    Janssens, Pilou L. H. R.; Penders, John; Hursel, Rick; Budding, Andries E.; Savelkoul, Paul H. M.; Westerterp-Plantenga, Margriet S.

    2016-01-01

    Background Green tea catechins may play a role in body weight regulation through interactions with the gut microbiota. Aim We examined whether green tea supplementation for 12 weeks induces changes in composition of the human gut microbiota. Methods 58 Caucasian men and women were included in a randomized, placebo-controlled design. For 12 weeks, subjects consumed either green tea (>0.56 g/d epigallocatechin-gallate + 0.28 ∼ 0.45 g/d caffeine) or placebo capsules. Fecal samples were collected twice (baseline, vs. week 12) for analyses of total bacterial profiles by means of IS-profiling, a 16S-23S interspacer region-based profiling method. Results No significant changes between baseline and week 12 in subjects receiving green tea or placebo capsules, and no significant interactions between treatment (green tea or placebo) and time (baseline and week 12) were observed for body composition. Analysis of the fecal samples in subjects receiving green tea and placebo showed similar bacterial diversity and community structures, indicating there were no significant changes in bacterial diversity between baseline and week 12 in subjects receiving green tea capsules or in subjects receiving placebo capsules. No significant interactions were observed between treatment (green tea or placebo) and time (baseline and week 12) for the gut microbial diversity. Although, there were no significant differences between normal weight and overweight subjects in response to green tea, we did observe a reduced bacterial alpha diversity in overweight as compared to normal weight subjects (p = 0.002). Conclusion Green tea supplementation for 12 weeks did not have a significant effect on composition of the gut microbiota. Trial Registration ClinicalTrials.gov NCT01556321 PMID:27054321

  7. Short-term hypoxic exposure at rest and during exercise reduces lung water in healthy humans.

    PubMed

    Snyder, Eric M; Beck, Kenneth C; Hulsebus, Minelle L; Breen, Jerome F; Hoffman, Eric A; Johnson, Bruce D

    2006-12-01

    Hypoxia and hypoxic exercise increase pulmonary arterial pressure, cause pulmonary capillary recruitment, and may influence the ability of the lungs to regulate fluid. To examine the influence of hypoxia, alone and combined with exercise, on lung fluid balance, we studied 25 healthy subjects after 17-h exposure to 12.5% inspired oxygen (barometric pressure = 732 mmHg) and sequentially after exercise to exhaustion on a cycle ergometer with 12.5% inspired oxygen. We also studied subjects after a rapid saline infusion (30 ml/kg over 15 min) to demonstrate the sensitivity of our techniques to detect changes in lung water. Pulmonary capillary blood volume (Vc) and alveolar-capillary conductance (D(M)) were determined by measuring the diffusing capacity of the lungs for carbon monoxide and nitric oxide. Lung tissue volume and density were assessed using computed tomography. Lung water was estimated by subtracting measures of Vc from computed tomography lung tissue volume. Pulmonary function [forced vital capacity (FVC), forced expiratory volume after 1 s (FEV(1)), and forced expiratory flow at 50% of vital capacity (FEF(50))] was also assessed. Saline infusion caused an increase in Vc (42%), tissue volume (9%), and lung water (11%), and a decrease in D(M) (11%) and pulmonary function (FVC = -12 +/- 9%, FEV(1) = -17 +/- 10%, FEF(50) = -20 +/- 13%). Hypoxia and hypoxic exercise resulted in increases in Vc (43 +/- 19 and 51 +/- 16%), D(M) (7 +/- 4 and 19 +/- 6%), and pulmonary function (FVC = 9 +/- 6 and 4 +/- 3%, FEV(1) = 5 +/- 2 and 4 +/- 3%, FEF(50) = 4 +/- 2 and 12 +/- 5%) and decreases in lung density and lung water (-84 +/- 24 and -103 +/- 20 ml vs. baseline). These data suggest that 17 h of hypoxic exposure at rest or with exercise resulted in a decrease in lung water in healthy humans. PMID:16902060

  8. Long term observation of low-power diode laser welding after penetrating keratoplasty in human patients

    NASA Astrophysics Data System (ADS)

    Rossi, Francesca; Matteini, Paolo; Pini, Roberto; Menabuoni, Luca; Lenzetti, Ivo

    2010-02-01

    Low power diode laser welding is a recently developed technique used as a support tool for conventional suturing in ophthalmic surgery. The main application is in penetrating keratoplasty: in the last four years (2005-2009), clinical trials were performed at the Ophthalmic Department of Prato, Italy). In penetrating keratoplasty, diode laser welding is used to assure the transplanted corneal button in its final position. The donor tissue is positioned in the recipient eye and 8-16 single stitches are apposed. The surgical wound is then stained with a saturated (10% w/w) sterile water solution of Indocyanine Green (ICG), it is washed with sterile water and then a diode laser (810 nm, 13 W/cm2) is used to induce the sealing of the wound. The laser light induces a thermal effect, localized in the stained tissue. In vivo and ex vivo studies in animal models evidenced that welding induces a modification of the corneal collagen architecture through the wound walls, thus enabling a short healing time and a good restoration of the tissue. In this study on human subjects, we confirmed the results evidenced in animal models, by morphological observations. In two cases out of 60, transplant rejection was observed. It was thus possible to study the efficacy of laser welding in the closure of the wound one year after implant. Direct morphological observation evidenced good strengthens of the welded tissue. Histological analysis pointed out a good restoration of the regular collagen architecture at the external perimeter of the corneal button, where laser welding was performed, showing the occurrence of a correct and effective wound healing process.

  9. Does Enhanced External Counterpulsation (EECP) Significantly Affect Myocardial Perfusion?: A Systematic Review & Meta-Analysis

    PubMed Central

    Qin, Xiaoxia; Deng, Yanye; Wu, Dandong; Yu, Lehua; Huang, Rongzhong

    2016-01-01

    Background Enhanced external counterpulsation (EECP) is currently applied for treating coronary artery disease (CAD) patients. However, the mechanism(s) by which EECP ameliorates angina pectoris and long-term left ventricular function remain largely unknown. The aim of this study will be to assess whether EECP significantly affects myocardial perfusion in CAD patients through a systematic review and meta-analysis of the available literature. Methods MEDLINE, EMBASE, and Cochrane CENTRAL databases were searched for prospective studies on CAD patients that underwent EECP and reported myocardial perfusion data pre- and post-EECP. The impact of EECP was assessed based on the weighted mean difference (WMD) in myocardial perfusion from pre-EECP to post-EECP. Statistical heterogeneity was assessed by the I2 index. Publication bias was assessed through visual inspection of the funnel plot as well as Begg’s and Egger’s testing. Results Standard EECP therapy (i.e., 35–36 one-hour sessions within a seven-week period) significantly increased myocardial perfusion in CAD patients (pooled WMD: -0.19, 95% CI: -0.38 to 0.00, p = 0.049). A random effects analysis was applied on account of significant heterogeneity (I2 = 89.1%, p = 0.000). There was no evidence of significant publication bias (Begg’s p = 0.091; Egger’s p = 0.282). Conclusions Standard EECP therapy significantly increases myocardial perfusion in CAD patients. This study’s findings support the continued use of standard EECP therapy in CAD patients and provides one putative physiological mechanism to help explain the improvements in angina pectoris and long-term left ventricular function observed in CAD patients after EECP therapy. PMID:27045935

  10. Effects of transforming growth factor-beta on long-term human cord blood monocyte cultures

    SciTech Connect

    Orcel, P.; Bielakoff, J.; De Vernejoul, M.C. )

    1990-02-01

    Transforming growth factor-beta (TGF-beta) modulates growth and differentiation in many cell types and is abundant in bone matrix. We recently showed that human cord blood monocytes cultured in the presence of 1,25(OH)2D3 acquire some features of osteoclast precursors. Since TGF-beta has been shown to influence bone resorption in organ culture, we have studied the effect of TGF-beta (1-1,000 pg/ml) on cord blood monocyte cultures. These cells were cultured on plastic substrate during 3 weeks in the presence of 20% horse serum and 10(-9) M 1,25(OH)2D3. TGF-beta, from a concentration of 10 pg/ml in the culture medium, decreased in a dose dependent manner the formation of multinucleated cells. At a concentration of TGF-beta of 1 ng/ml, the multinucleated cells were reduced to 2.1% +/- 0.3%, compared to 19.3% +/- 1.5% in control cultures. TGF-beta inhibited in a dose-dependent manner the proliferation of cord blood monocytes as assessed by 3H-thymidine incorporation at 7 and 14 days of culture. The fusion index was also decreased by 3 weeks of treatment with TGF-beta. Indomethacin did not reverse the inhibitory effects of TGF-beta. The expression of the osteoclastic phenotype was assessed using two different antibodies: 23C6, a monoclonal antibody directed against the vitronectin receptor, which is highly expressed by osteoclasts but not by adult monocytes, and an antibody to HLA-DR, which is not present on osteoclast. TGF-beta decreased the expression of HLA-DR and increased in a dose-dependent manner the proportion of 23C6-labeled cells; these results suggest that TGF-beta could modulate a differentiation effect to the osteoclastic phenotype. However, when cord blood monocytes were cultured on devitalized rat calvariae prelabeled with 45Ca, TGF-beta did not induce any 45Ca release from bone cultured with monocytes.

  11. Imaging considerations for a technetium-99m myocardial perfusion agent

    SciTech Connect

    English, R.J.; Jones, A.G.; Davison, A.; Lister-James, J.; Campbell, S.; Holman, B.L.

    1986-03-01

    Myocardial perfusion imaging with /sup 201/Tl chloride suffers from a number of physical, geometric, and dosimetric constraints that could be diminished if an agent labeled with /sup 99m/Tc were available. The cationic complex /sup 99m/Tc hexakis-(t-butylisonitrile)technetium(I) ((/sup 99m/Tc)TBI) has been shown to concentrate in the myocardial tissue of both animals and humans, with preliminary clinical studies demonstrating a number of technical attributes not possible with /sup 201/Tl. Technetium-99m-TBI is a promising myocardial imaging agent that may permit high quality planar, gated, and tomographic imaging of both myocardial ischemia and infarction with reduced imaging times and improved resolution.

  12. A Porcine Anterior Segment Perfusion and Transduction Model With Direct Visualization of the Trabecular Meshwork

    PubMed Central

    Loewen, Ralitsa T.; Roy, Pritha; Park, Daniel B.; Jensen, Adrianna; Scott, Gordon; Cohen-Karni, Devora; Fautsch, Michael P.; Schuman, Joel S.; Loewen, Nils A.

    2016-01-01

    Purpose To establish a consistent and affordable, high quality porcine anterior segment perfusion and transduction model that allows direct visualization of the trabecular meshwork. Methods Porcine anterior segments were cultured within 2 hours of death by removing lens and uvea and securing in a specially designed petri dish with a thin bottom to allow direct visualization of the trabecular meshwork with minimal distortion. Twenty-two control eyes (CO) with a constant flow rate were compared to eight gravity perfused eyes (COgr, 15 mm Hg). We established gene delivery to the TM using eGFP expressing feline immunodeficiency virus (FIV) vector GINSIN at 108 transducing units (TU) per eye (GINSIN_8, n = 8) and 107 TU (GINSIN_7, n = 8). Expression was assessed for 14 days before histology was obtained. Results Pig eyes were a reliable source for consistent and high quality anterior segment cultures with a low failure rate of 12%. Control eyes had an intraocular pressure (IOP) of 15.8 ± 1.9 mm Hg at fixed pump perfusion with 3 μL/min compared to gravity perfused COgr with imputed 3.7 ± 1.6 μL/min. Vector GINSIN_8 eyes experienced a transient posttransduction IOP increase of 44% that resolved at 48 hours; this was not observed in GINSIN_7 eyes. Expression was higher in GINSIN_8 than in GINSIN_7 eyes. Trabecular meshwork architecture was well preserved. Conclusions Compared with previously used human donor eyes, this inexpensive porcine anterior segment perfusion model is of sufficient, repeatable high quality to develop strategies of TM bioengineering. Trabecular meshwork could be observed directly. Despite significant anatomic differences, effects of transduction replicate the main aspects of previously explored human, feline and rodent models. PMID:27002293

  13. Perfusion techniques for minimally invasive valve procedures.

    PubMed

    de Jong, A; Popa, B A; Stelian, E; Karazanishvili, L; Lanzillo, G; Simonini, S; Renzi, L; Diena, M; Tesler, U F

    2015-05-01

    In this paper, we present, in detail, the simplified perfusion technique that we have adopted since January 2009 and that we have utilized in 200 cases for cardiac minimally invasive valvular procedures that were performed through a right lateral mini-thoracotomy in the 3(rd)-4(th) intercostal space. Cardiopulmonary bypass was achieved by means of the direct cannulation of the ascending aorta and the insertion of a percutaneous venous cannula in the femoral vein. A flexible aortic cross-clamp was applied through the skin incision and cardioplegic arrest was obtained with the antegrade delivery of a crystalloid solution. Gravity drainage was enhanced by vacuum-assisted aspiration. There were no technical complications related to this perfusion technique that we have adopted in minimally invasive surgical procedures. PMID:25280878

  14. Assessment of cerebral perfusion in childhood strokes

    SciTech Connect

    Gates, G.F.; Fishman, L.S.; Segall, H.D.

    1982-11-01

    Thirty-three children who had strokes were studied by dynamic and static scintigraphy, 29 by CT scanning, and 10 by cerebral angiography. The accuracy of dynamic scintigraphy in stroke detection during the first week of clinical symptoms was 94% while CT scanning was 60% accurate and static scintigraphy 11% accurate. During the second week the accuracy of CT scanning increased to 100%, but static scintigraphy improved to only 50%. Fifty percent of scintiangiograms performed during the first week showed either luxuriant perfusion or flip-flop patterns. In some patients these two flow patterns changed to that of cerebral hemispheric ischemia after going through a phase during which perfusion appeared to be equal in the two hemispheres. Dynamic scintigraphy is believed to be the test of choice for stroke detection in children during the first week.

  15. Visual analysis of longitudinal brain tumor perfusion

    NASA Astrophysics Data System (ADS)

    Glaßer, Sylvia; Oeltze, Steffen; Preim, Uta; Bjørnerud, Atle; Hauser, Helwig; Preim, Bernhard

    2013-02-01

    In clinical research on diagnosis and evaluation of brain tumors, longitudinal perfusion MRI studies are acquired for tumor grading as well as to monitor and assess treatment response and patient prognosis. Within this work, we demonstrate how visual analysis techniques can be adapted to multidimensional datasets from such studies within a framework to support the computer-aided diagnosis of brain tumors. Our solution builds on two innovations: First, we introduce a pipeline yielding comparative, co-registered quantitative perfusion parameter maps over all time steps of the longitudinal study. Second, based on these time-dependent parameter maps, visual analysis methods were developed and adapted to reveal valuable insight into tumor progression, especially regarding the clinical research area of low grade glioma transformation into high grade gliomas. Our examination of four longitudinal brain studies demonstrates the suitability of the presented visual analysis methods and comprises new possibilities for the clinical researcher to characterize the development of low grade gliomas.

  16. The effect of acute and long-term physical activity on extracellular matrix and serglycin in human skeletal muscle

    PubMed Central

    Hjorth, Marit; Norheim, Frode; Meen, Astri J; Pourteymour, Shirin; Lee, Sindre; Holen, Torgeir; Jensen, Jørgen; Birkeland, Kåre I; Martinov, Vladimir N; Langleite, Torgrim M; Eckardt, Kristin; Drevon, Christian A; Kolset, Svein O

    2015-01-01

    Remodeling of extracellular matrix (ECM), including regulation of proteoglycans in skeletal muscle can be important for physiological adaptation to exercise. To investigate the effects of acute and long-term exercise on the expression of ECM-related genes and proteoglycans in particular, 26 middle-aged, sedentary men underwent a 12 weeks supervised endurance and strength training intervention and two acute, 45 min bicycle tests (70% VO2max), one at baseline and one after 12 weeks of training. Total gene expression in biopsies from m. vastus lateralis was measured with deep mRNA sequencing. After 45 min of bicycling approximately 550 gene transcripts were >50% upregulated. Of these, 28 genes (5%) were directly related to ECM. In response to long-term exercise of 12 weeks 289 genes exhibited enhanced expression (>50%) and 20% of them were ECM related. Further analyses of proteoglycan mRNA expression revealed that more than half of the proteoglycans expressed in muscle were significantly enhanced after 12 weeks intervention. The proteoglycan serglycin (SRGN) has not been studied in skeletal muscle and was one of few proteoglycans that showed increased expression after acute (2.2-fold, P < 0.001) as well as long-term exercise (1.4-fold, P < 0.001). Cultured, primary human skeletal muscle cells expressed and secreted SRGN. When the expression of SRGN was knocked down, the expression and secretion of serpin E1 (SERPINE1) increased. In conclusion, acute and especially long-term exercise promotes enhanced expression of several ECM components and proteoglycans. SRGN is a novel exercise-regulated proteoglycan in skeletal muscle with a potential role in exercise adaptation. PMID:26290530

  17. Long-term fate of depleted uranium at Aberdeen and Yuma Proving Grounds: Human health and ecological risk assessments

    SciTech Connect

    Ebinger, M.H.; Beckman, R.J.; Myers, O.B.; Kennedy, P.L.; Clements, W.; Bestgen, H.T.

    1996-09-01

    The purpose of this study was to evaluate the immediate and long-term consequences of depleted uranium (DU) in the environment at Aberdeen Proving Ground (APG) and Yuma Proving Ground (YPG) for the Test and Evaluation Command (TECOM) of the US Army. Specifically, we examined the potential for adverse radiological and toxicological effects to humans and ecosystems caused by exposure to DU at both installations. We developed contaminant transport models of aquatic and terrestrial ecosystems at APG and terrestrial ecosystems at YPG to assess potential adverse effects from DU exposure. Sensitivity and uncertainty analyses of the initial models showed the portions of the models that most influenced predicted DU concentrations, and the results of the sensitivity analyses were fundamental tools in designing field sampling campaigns at both installations. Results of uranium (U) isotope analyses of field samples provided data to evaluate the source of U in the environment and the toxicological and radiological doses to different ecosystem components and to humans. Probabilistic doses were estimated from the field data, and DU was identified in several components of the food chain at APG and YPG. Dose estimates from APG data indicated that U or DU uptake was insufficient to cause adverse toxicological or radiological effects. Dose estimates from YPG data indicated that U or DU uptake is insufficient to cause radiological effects in ecosystem components or in humans, but toxicological effects in small mammals (e.g., kangaroo rats and pocket mice) may occur from U or DU ingestion. The results of this study were used to modify environmental radiation monitoring plans at APG and YPG to ensure collection of adequate data for ongoing ecological and human health risk assessments.

  18. Gluconeogenesis in the perfused rat liver.

    PubMed

    Hems, R; Ross, B D; Berry, M N; Krebs, H A

    1966-11-01

    1. A modification of the methods of Miller and of Schimassek for the perfusion of the isolated rat liver, suitable for the study of gluconeogenesis, is described. 2. The main modifications concern the operative technique (reducing the period of anoxia during the operation to 3min.) and the use of aged (non-glycolysing) red cells in the semi-synthetic perfusion medium. 3. The performance of the perfused liver was tested by measuring the rate of gluconeogenesis, of urea synthesis and the stability of adenine nucleotides. Higher rates of gluconeogenesis (1mumole/min./g.) from excess of lactate and of urea synthesis from excess of ammonia (4mumoles/min./g. in the presence of ornithine) were observed than are likely to occur in vivo where rates are limited by the rate of supply of precursor. The concentrations of the three adenine nucleotides in the liver tissue were maintained within 15% over a perfusion period of 135min. 4. Ca(2+), Na(+), K(+), Mg(2+) and phosphate were found to be required at physiological concentrations for optimum gluconeogenesis but bicarbonate and carbon dioxide could be largely replaced by phosphate buffer without affecting the rate of gluconeogenesis. 5. Maximal gluconeogenesis did not decrease maximal urea synthesis in the presence of ornithine and ammonia and vice versa. This indicates that the energy requirements were not limiting the rates of gluconeogenesis or of urea synthesis. 6. Addition of lactate, and especially ammonium salts, increased the uptake of oxygen more than expected on the basis of the ATP requirements of the gluconeogenesis and urea synthesis. PMID:5966267

  19. Dynamic CT perfusion measurement in a cardiac phantom.

    PubMed

    Ziemer, Benjamin P; Hubbard, Logan; Lipinski, Jerry; Molloi, Sabee

    2015-10-01

    Widespread clinical implementation of dynamic CT myocardial perfusion has been hampered by its limited accuracy and high radiation dose. The purpose of this study was to evaluate the accuracy and radiation dose reduction of a dynamic CT myocardial perfusion technique based on first pass analysis (FPA). To test the FPA technique, a pulsatile pump was used to generate known perfusion rates in a range of 0.96-2.49 mL/min/g. All the known perfusion rates were determined using an ultrasonic flow probe and the known mass of the perfusion volume. FPA and maximum slope model (MSM) perfusion rates were measured using volume scans acquired from a 320-slice CT scanner, and then compared to the known perfusion rates. The measured perfusion using FPA (P(FPA)), with two volume scans, and the maximum slope model (P(MSM)) were related to known perfusion (P(K)) by P(FPA) = 0.91P(K) + 0.06 (r = 0.98) and P(MSM) = 0.25P(K) - 0.02 (r = 0.96), respectively. The standard error of estimate for the FPA technique, using two volume scans, and the MSM was 0.14 and 0.30 mL/min/g, respectively. The estimated radiation dose required for the FPA technique with two volume scans and the MSM was 2.6 and 11.7-17.5 mSv, respectively. Therefore, the FPA technique can yield accurate perfusion measurements using as few as two volume scans, corresponding to approximately a factor of four reductions in radiation dose as compared with the currently available MSM. In conclusion, the results of the study indicate that the FPA technique can make accurate dynamic CT perfusion measurements over a range of clinically relevant perfusion rates, while substantially reducing radiation dose, as compared to currently available dynamic CT perfusion techniques. PMID:26156231

  20. The effect of captopril on thallium 201 myocardial perfusion in systemic sclerosis

    SciTech Connect

    Kahan, A.; Devaux, J.Y.; Amor, B.; Menkes, C.J.; Weber, S.; Venot, A.; Strauch, G. )

    1990-04-01

    In systemic sclerosis, abnormalities of myocardial perfusion are common and may be caused by a disturbance of the coronary microcirculation. We evaluated the long-term effect of captopril (75 to 150 mg per day) on thallium 201 myocardial perfusion in 12 normotensive patients with systemic sclerosis. Captopril significantly decreased the mean (+/- SD) number of segments with thallium 201 myocardial perfusion defects (6.5 +/- 1.9 at baseline and 4.4 +/- 2.7 after 1 year of treatment with captopril; p less than 0.02) and increased the mean global thallium score (9.6 +/- 1.7 at baseline and 11.4 +/- 2.1 after captopril; p less than 0.05). In a control group of eight normotensive patients with systemic sclerosis who did not receive captopril, no significant modification in thallium results occurred. Side effects with captopril included hypotension (six patients), taste disturbances (one patient), and skin rash (one patient). These side effects subsided when the dosage was reduced. These findings demonstrate that captopril improves thallium 201 myocardial perfusion in patients with systemic sclerosis and may therefore have a beneficial effect on scleroderma myocardial disease.

  1. Changes of perfusion of microvascular free flaps in the head and neck: a prospective clinical study.

    PubMed

    Mücke, Thomas; Rau, Andrea; Merezas, Andreas; Kanatas, Anastasios; Mitchell, David A; Wagenpfeil, Stefan; Wolff, Klaus-Dietrich; Steiner, Timm

    2014-11-01

    Reconstruction with a free flap is routine in head and neck surgery. However, reliable assessment of perfusion can be difficult, so we prospectively evaluated it in 4 types of microvascular free flaps in the oral cavity (n=196) and assessed differences in blood flow by non-invasive monitoring with a laser Doppler flowmetry unit. We measured oxygen saturation, haemoglobin concentration, and velocity on the surface of the flap preoperatively at the donor site, and on the flap on the first, second, and seventh postoperative days, and after 4 weeks in 186/196 patients, mean (SD) age of 60 (13) years. We studied the radial forearm (n=76, 41%), fibular (n=45, 24%), anterolateral thigh (n=53, 28%), and soleus perforator (n=12, 7%) flaps. The values for the radial forearm flap differed significantly from the others. There were significant differences in haemoglobin concentrations between the fibular and soleus perforator flaps, and between the anterolateral thigh and soleus perforator flaps (p=0.002 each). Free flaps are unique in the way that perfusion develops after microvascular anastomoses. Knowledge of how each flap is perfused may indicate different patterns of healing that could potentially influence long term rehabilitation and detection of future deficits in perfusion. PMID:25149324

  2. Inhomogeneity of pulmonary perfusion during sustained microgravity

    NASA Technical Reports Server (NTRS)

    Prisk, G. Kim; Guy, Harold J. B.; Elliott, Ann R.; West, John B.

    1994-01-01

    The effects of gravity on the inhomogeneity of pulmonary perfusion in man were studied by performing hyperventilation-breathhold single-breath measurements before, during and after 9 days of continuous exposure to microgravity. In microgravity the indicators of inhomogeneity of perfusion, especially the size of cardiogenic oscillations in expired CO2 and the height of phase 4, were both markedly reduced. Cardiogenic oscillations were reduced to approximately 60 of their preflight standing size, while the height of phase 4 was between 0 and -8% (a terminal fall became a small terminal rise) of preflights standing. The terminal change in CO2 was nearly abolished in microgravity indicating more uniformity of blood flow between lung units that close at the end of expiration and units that remain open. This may result from the disappearance of gravity-dependent topographical inequality of blood flow. The residual cardiographic oscillations in expired CO2 imply a persisting inhomogeneity of perfusion in the absence of gravity at a level larger than acinar.

  3. Regulation of skeletal muscle perfusion during exercise

    NASA Technical Reports Server (NTRS)

    Delp, M. D.; Laughlin, M. H.

    1998-01-01

    For exercise to be sustained, it is essential that adequate blood flow be provided to skeletal muscle. The local vascular control mechanisms involved in regulating muscle perfusion during exercise include metabolic control, endothelium-mediated control, propagated responses, myogenic control, and the muscle pump. The primary determinant of muscle perfusion during sustained exercise is the metabolic rate of the muscle. Metabolites from contracting muscle diffuse to resistance arterioles and act directly to induce vasodilation, or indirectly to inhibit noradrenaline release from sympathetic nerve endings and oppose alpha-adrenoreceptor-mediated vasoconstriction. The vascular endothelium also releases vasodilator substances (e.g., prostacyclin and nitric oxide) that are prominent in establishing basal vascular tone, but these substances do not appear to contribute to the exercise hyperemia in muscle. Endothelial and smooth muscle cells may also be involved in propagating vasodilator signals along arterioles to parent and daughter vessels. Myogenic autoregulation does not appear to be involved in the exercise hyperemia in muscle, but the rhythmic propulsion of blood from skeletal muscle veins facilitates venous return to the heart and muscle perfusion. It appears that the primary determinants of sustained exercise hyperemia in skeletal muscle are metabolic vasodilation and increased vascular conductance via the muscle pump. Additionally, sympathetic neural control is important in regulating muscle blood flow during exercise.

  4. Perfusion computed tomography in renal cell carcinoma.

    PubMed

    Das, Chandan J; Thingujam, Usha; Panda, Ananya; Sharma, Sanjay; Gupta, Arun Kumar

    2015-07-28

    Various imaging modalities are available for the diagnosis, staging and response evaluation of patients with renal cell carcinoma (RCC). While contrast enhanced computed tomography (CT) is used as the standard of imaging for size, morphological evaluation and response assessment in RCC, a new functional imaging technique like perfusion CT (pCT), goes down to the molecular level and provides new perspectives in imaging of RCC. pCT depicts regional tumor perfusion and vascular permeability which are indirect parameters of tumor angiogenesis and thereby provides vital information regarding tumor microenvironment. Also response evaluation using pCT may predate the size criteria used in Response Evaluation Criteria in Solid Tumors, as changes in the perfusion occurs earlier following tissue kinase inhibitors before any actual change in size. This may potentially help in predicting prognosis, better selection of therapy and more accurate and better response evaluation in patients with RCC. This article describes the techniques and role of pCT in staging and response assessment in patients with RCCs. PMID:26217456

  5. Noncontact blood perfusion mapping in clinical applications

    NASA Astrophysics Data System (ADS)

    Iakovlev, Dmitry; Dwyer, Vincent; Hu, Sijung; Silberschmidt, Vadim

    2016-04-01

    Non-contact imaging photoplethysmography (iPPG) to detect pulsatile blood microcirculation in tissue has been selected as a successor to low spatial resolution and slow scanning blood perfusion techniques currently employed by clinicians. The proposed iPPG system employs a novel illumination source constructed of multiple high power LEDs with narrow spectral emission, which are temporally modulated and synchronised with a high performance sCMOS sensor. To ensure spectrum stability and prevent thermal wavelength drift due to junction temperature variations, each LED features a custom-designed thermal management system to effectively dissipate generated heat and auto-adjust current flow. The use of a multi-wavelength approach has resulted in simultaneous microvascular perfusion monitoring at various tissue depths, which is an added benefit for specific clinical applications. A synchronous detection algorithm to extract weak photoplethysmographic pulse-waveforms demonstrated robustness and high efficiency when applied to even small regions of 5 mm2. The experimental results showed evidences that the proposed system could achieve noticeable accuracy in blood perfusion monitoring by creating complex amplitude and phase maps for the tissue under examination.

  6. Parallel perfusion imaging processing using GPGPU

    PubMed Central

    Zhu, Fan; Gonzalez, David Rodriguez; Carpenter, Trevor; Atkinson, Malcolm; Wardlaw, Joanna

    2012-01-01

    Background and purpose The objective of brain perfusion quantification is to generate parametric maps of relevant hemodynamic quantities such as cerebral blood flow (CBF), cerebral blood volume (CBV) and mean transit time (MTT) that can be used in diagnosis of acute stroke. These calculations involve deconvolution operations that can be very computationally expensive when using local Arterial Input Functions (AIF). As time is vitally important in the case of acute stroke, reducing the analysis time will reduce the number of brain cells damaged and increase the potential for recovery. Methods GPUs originated as graphics generation dedicated co-processors, but modern GPUs have evolved to become a more general processor capable of executing scientific computations. It provides a highly parallel computing environment due to its large number of computing cores and constitutes an affordable high performance computing method. In this paper, we will present the implementation of a deconvolution algorithm for brain perfusion quantification on GPGPU (General Purpose Graphics Processor Units) using the CUDA programming model. We present the serial and parallel implementations of such algorithms and the evaluation of the performance gains using GPUs. Results Our method has gained a 5.56 and 3.75 speedup for CT and MR images respectively. Conclusions It seems that using GPGPU is a desirable approach in perfusion imaging analysis, which does not harm the quality of cerebral hemodynamic maps but delivers results faster than the traditional computation. PMID:22824549

  7. Whole Animal Perfusion Fixation for Rodents

    PubMed Central

    Gage, Gregory J.; Kipke, Daryl R.; Shain, William

    2012-01-01

    The goal of fixation is to rapidly and uniformly preserve tissue in a life-like state. While placing tissue directly in fixative works well for small pieces of tissue, larger specimens like the intact brain pose a problem for immersion fixation because the fixative does not reach all regions of the tissue at the same rate 5,7. Often, changes in response to hypoxia begin before the tissue can be preserved 12. The advantage of directly perfusing fixative through the circulatory system is that the chemical can quickly reach every corner of the organism using the natural vascular network. In order to utilize the circulatory system most effectively, care must be taken to match physiological pressures 3. It is important to note that physiological pressures are dependent on the species used. Techniques for perfusion fixation vary depending on the tissue to be fixed and how the tissue will be processed following fixation. In this video, we describe a low-cost, rapid, controlled and uniform fixation procedure using 4% paraformaldehyde perfused via the vascular system: through the heart of the rat to obtain the best possible preservation of the brain for immunohistochemistry. The main advantage of this technique (vs. gravity-fed systems) is that the circulatory system is utilized most effectively. PMID:22871843

  8. Perfusion-decellularized skeletal muscle as a three-dimensional scaffold with a vascular network template.

    PubMed

    Zhang, Jian; Hu, Zhi Qian; Turner, Neill J; Teng, Shi Feng; Cheng, Wen Yue; Zhou, Hai Yang; Zhang, Li; Hu, Hong Wei; Wang, Qiang; Badylak, Stephen F

    2016-05-01

    There exists a great need for repair grafts with similar volume to human skeletal muscle that can promote the innate ability of muscle to regenerate following volumetric muscle loss. Perfusion decellularization is an attractive technique for extracellular matrix (ECM) scaffold from intact mammalian organ or tissue which has been successfully used in tissue reconstruction. The perfusion-decellularization of skeletal muscle has been poorly assessed and characterized, but the bioactivity and functional capacity of the obtained perfusion skeletal muscle ECM (pM-ECM) to remodel in vivo is unknown. In the present study, pM-ECM was prepared from porcine rectus abdominis (RA). Perfusion-decellularization of porcine RA effectively removed cellular and nuclear material while retaining the intricate three-dimensional microarchitecture and vasculature networks of the native RA, and many of the bioactive ECM components and mechanical properties. In vivo, partial-thickness abdominal wall defects in rats repaired with pM-ECM showed improved neovascularization, myogenesis and functional recellularization compared to porcine-derived small intestinal submucosa (SIS). These findings show the biologic potential of RA pM-ECM as a scaffold for supporting site appropriate, tissue reconstruction, and provide a better understanding of the importance maintaining the tissue-specific complex three-dimensional architecture of ECM during decellularization and regeneration. PMID:26963901

  9. Optimization of electron microscopy for human brains with long-term fixation and fixed-frozen sections

    PubMed Central

    2014-01-01

    Background Abnormal connectivity across brain regions underlies many neurological disorders including multiple sclerosis, schizophrenia and autism, possibly due to atypical axonal organization within white matter. Attempts at investigating axonal organization on post-mortem human brains have been hindered by the availability of high-quality, morphologically preserved tissue, particularly for neurodevelopmental disorders such as autism. Brains are generally stored in a fixative for long periods of time (often greater than 10 years) and in many cases, already frozen and sectioned on a microtome for histology and immunohistochemistry. Here we present a method to assess the quality and quantity of axons from long-term fixed and frozen-sectioned human brain samples to demonstrate their use for electron microscopy (EM) measures of axonal ultrastructure. Results Six samples were collected from white matter below the superior temporal cortex of three typically developing human brains and prepared for EM analyses. Five samples were stored in fixative for over 10 years, two of which were also flash frozen and sectioned on a freezing microtome, and one additional case was fixed for 3 years and sectioned on a freezing microtome. In all six samples, ultrastructural qualitative and quantitative analyses demonstrate that myelinated axons can be identified and counted on the EM images. Although axon density differed between brains, axonal ultrastructure and density was well preserved and did not differ within cases for fixed and frozen tissue. There was no significant difference between cases in axon myelin sheath thickness (g-ratio) or axon diameter; approximately 70% of axons were in the small (0.25 μm) to medium (0.75 μm) range. Axon diameter and g-ratio were positively correlated, indicating that larger axons may have thinner myelin sheaths. Conclusion The current study demonstrates that long term formalin fixed and frozen-sectioned human brain tissue can be used for

  10. Phenotypic characteristics of three human non-Hodgkin lymphoma lines: flow cytometric analysis after long-term maintenance.

    PubMed Central

    Kopper, L; Bánkfalvi, A; Mihalik, R; Páloczi, K; Benczur, M; Lapis, K

    1988-01-01

    Three human non-Hodgkin lymphomas of B-cell origin have been maintained as xenografts in artificially immunosuppressed mice. The long-term maintenance (3-5 years) resulted in no significant change in the morphology, DNA-index or cell surface markers of the tumors. Immunophenotyping revealed many similarities in the morphologically distinct lines. Light chain (lambda) restriction appeared in two lines (HT 58 and 130), but in the third line (HT 117) the co-expression of both light chains indicated the origin from light chain 'uncommitted' B cells. HT 117 was also different, expressing high transferrin-receptor activity, although it proliferates with practically the same rate as the other two lines. This study confirms the value of the xenograft system to approaching many tumor-specific problems. Images Fig. 1 PMID:3224446

  11. Multipotent human stromal cells improve cardiac function after myocardial infarction in mice without long-term engraftment

    SciTech Connect

    Iso, Yoshitaka; Spees, Jeffrey L.; E-mail: Jeffrey.Spees@uvm.edu; Serrano, Claudia; Bakondi, Benjamin; Pochampally, Radhika; Song, Yao-Hua; Sobel, Burton E.; Delafontaine, Patrick; Prockop, Darwin J. . E-mail: dprocko@tulane.edu

    2007-03-16

    The aim of this study was to determine whether intravenously administered multipotent stromal cells from human bone marrow (hMSCs) can improve cardiac function after myocardial infarction (MI) without long-term engraftment and therefore whether transitory paracrine effects or secreted factors are responsible for the benefit conferred. hMSCs were injected systemically into immunodeficient mice with acute MI. Cardiac function and fibrosis after MI in the hMSC-treated group were significantly improved compared with controls. However, despite the cardiac improvement, there was no evident hMSC engraftment in the heart 3 weeks after MI. Microarray assays and ELISAs demonstrated that multiple protective factors were expressed and secreted from the hMSCs in culture. Factors secreted by hMSCs prevented cell death of cultured cardiomyocytes and endothelial cells under conditions that mimicked tissue ischemia. The favorable effects of hMSCs appear to reflect the impact of secreted factors rather than engraftment, differentiation, or cell fusion.

  12. Long-term expansion, enhanced chondrogenic potential, and suppression of endochondral ossification of adult human MSCs via WNT signaling modulation.

    PubMed

    Narcisi, Roberto; Cleary, Mairéad A; Brama, Pieter A J; Hoogduijn, Martin J; Tüysüz, Nesrin; ten Berge, Derk; van Osch, Gerjo J V M

    2015-03-10

    Mesenchymal stem cells (MSCs) are a potential source of chondrogenic cells for the treatment of cartilage disorders, but loss of chondrogenic potential during in vitro expansion and the propensity of cartilage to undergo hypertrophic maturation impede their therapeutic application. Here we report that the signaling protein WNT3A, in combination with FGF2, supports long-term expansion of human bone marrow-derived MSCs. The cells retained their chondrogenic potential and other phenotypic and functional properties of multipotent MSCs, which were gradually lost in the absence of WNT3A. Moreover, we discovered that endogenous WNT signals are the main drivers of the hypertrophic maturation that follows chondrogenic differentiation. Inhibition of WNT signals during differentiation prevented calcification and maintained cartilage properties following implantation in a mouse model. By maintaining potency during expansion and preventing hypertrophic maturation following differentiation, the modulation of WNT signaling removes two major obstacles that impede the clinical application of MSCs in cartilage repair. PMID:25733021

  13. Towards robust deconvolution of low-dose perfusion CT: sparse perfusion deconvolution using online dictionary learning.

    PubMed

    Fang, Ruogu; Chen, Tsuhan; Sanelli, Pina C

    2013-05-01

    Computed tomography perfusion (CTP) is an important functional imaging modality in the evaluation of cerebrovascular diseases, particularly in acute stroke and vasospasm. However, the post-processed parametric maps of blood flow tend to be noisy, especially in low-dose CTP, due to the noisy contrast enhancement profile and the oscillatory nature of the results generated by the current computational methods. In this paper, we propose a robust sparse perfusion deconvolution method (SPD) to estimate cerebral blood flow in CTP performed at low radiation dose. We first build a dictionary from high-dose perfusion maps using online dictionary learning and then perform deconvolution-based hemodynamic parameters estimation on the low-dose CTP data. Our method is validated on clinical data of patients with normal and pathological CBF maps. The results show that we achieve superior performance than existing methods, and potentially improve the differentiation between normal and ischemic tissue in the brain. PMID:23542422

  14. Towards robust deconvolution of low-dose perfusion CT: Sparse perfusion deconvolution using online dictionary learning

    PubMed Central

    Fang, Ruogu; Chen, Tsuhan; Sanelli, Pina C.

    2014-01-01

    Computed tomography perfusion (CTP) is an important functional imaging modality in the evaluation of cerebrovascular diseases, particularly in acute stroke and vasospasm. However, the post-processed parametric maps of blood flow tend to be noisy, especially in low-dose CTP, due to the noisy contrast enhancement profile and the oscillatory nature of the results generated by the current computational methods. In this paper, we propose a robust sparse perfusion deconvolution method (SPD) to estimate cerebral blood flow in CTP performed at low radiation dose. We first build a dictionary from high-dose perfusion maps using online dictionary learning and then perform deconvolution-based hemodynamic parameters estimation on the low-dose CTP data. Our method is validated on clinical data of patients with normal and pathological CBF maps. The results show that we achieve superior performance than existing methods, and potentially improve the differentiation between normal and ischemic tissue in the brain. PMID:23542422

  15. Reconstructing long-term human impacts on plant communities: an ecological approach based on lake sediment DNA.

    PubMed

    Pansu, Johan; Giguet-Covex, Charline; Ficetola, Gentile Francesco; Gielly, Ludovic; Boyer, Frédéric; Zinger, Lucie; Arnaud, Fabien; Poulenard, Jérôme; Taberlet, Pierre; Choler, Philippe

    2015-04-01

    Paleoenvironmental studies are essential to understand biodiversity changes over long timescales and to assess the relative importance of anthropogenic and environmental factors. Sedimentary ancient DNA (sedaDNA) is an emerging tool in the field of paleoecology and has proven to be a complementary approach to the use of pollen and macroremains for investigating past community changes. SedaDNA-based reconstructions of ancient environments often rely on indicator taxa or expert knowledge, but quantitative ecological analyses might provide more objective information. Here, we analysed sedaDNA to investigate plant community trajectories in the catchment of a high-elevation lake in the Alps over the last 6400 years. We combined data on past and present plant species assemblages along with sedimentological and geochemical records to assess the relative impact of human activities through pastoralism, and abiotic factors (temperature and soil evolution). Over the last 6400 years, we identified significant variation in plant communities, mostly related to soil evolution and pastoral activities. An abrupt vegetational change corresponding to the establishment of an agropastoral landscape was detected during the Late Holocene, approximately 4500 years ago, with the replacement of mountain forests and tall-herb communities by heathlands and grazed lands. Our results highlight the importance of anthropogenic activities in mountain areas for the long-term evolution of local plant assemblages. SedaDNA data, associated with other paleoenvironmental proxies and present plant assemblages, appear to be a relevant tool for reconstruction of plant cover history. Their integration, in conjunction with classical tools, offers interesting perspectives for a better understanding of long-term ecosystem dynamics under the influence of human-induced and environmental drivers. PMID:25735209

  16. CT Perfusion Dynamics of Intracranial Tuberculomas

    PubMed Central

    N., Jayakumar Peruvumba; Shivashankar, Ravishankar

    2015-01-01

    Aims To study perfusion characteristics of intracranial tuberculomas and analyze changes with anti tubercular treatment. Materials and Methods Nineteen patients of histologically proven intracranial tuberculomas were included in the study of which 9 were not on antitubercular treatment and ten were on antitubercular treatment (6 patients on treatment for less than 2 months and 4 were more than 6 months). All patients underwent CT perfusion (CTP) and CTP parameters like rCBV and rCBF were obtained from entire lesion, center and capsule of lesions and compared. Results CTP parameters like rCBF and rCBV were significantly low in all the three ROIs in the group not on treatment compared to that of on treatment ; rCBF and rCBV of entire lesion (p=0.018 and p=0.005 respectively), capsule (p=0.045 and p=0.010 respectively) and center of the lesion (p=0.020 and p=0.009) respectively). Tuberculomas on antitubercular treatment of more than six months showed reduced rCBF and rCBV in entire lesion (p=0.01 & p=0.01 respectively), capsule (p=0.04 & p=0.03 respectively) and center (p=0.08 & p=0.05 respectively) compared to those on treatment for less than two months. Similarly tuberculomas on treatment for six months did not show significant difference in rCBF and rCBV compared to tuberculomas who were not on treatment. Tuberculomas on treatment for less than two months showed statistically increased rCBF and rCBV in entire lesion (p=0.01 & p=0.04 respectively), capsule (p=0.03 & p=0.01 respectively) and center (p= 0.03 &=0.01) compared to those not on treatment. Conclusion Intracranial tuberculomas not on treatment and those on treatment for around six months show low perfusion and tuberculomas on treatment for less than two months show high perfusion. These findings suggest that serial perfusion profiles of tuberculomas on treatment could possibly be seen as surrogate markers of response to treatment. PMID:26155528

  17. Developing a Benchmarking Process in Perfusion: A Report of the Perfusion Downunder Collaboration

    PubMed Central

    Baker, Robert A.; Newland, Richard F.; Fenton, Carmel; McDonald, Michael; Willcox, Timothy W.; Merry, Alan F.

    2012-01-01

    Abstract: Improving and understanding clinical practice is an appropriate goal for the perfusion community. The Perfusion Downunder Collaboration has established a multi-center perfusion focused database aimed at achieving these goals through the development of quantitative quality indicators for clinical improvement through benchmarking. Data were collected using the Perfusion Downunder Collaboration database from procedures performed in eight Australian and New Zealand cardiac centers between March 2007 and February 2011. At the Perfusion Downunder Meeting in 2010, it was agreed by consensus, to report quality indicators (QI) for glucose level, arterial outlet temperature, and pCO2 management during cardiopulmonary bypass. The values chosen for each QI were: blood glucose ≥4 mmol/L and ≤10 mmol/L; arterial outlet temperature ≤37°C; and arterial blood gas pCO2 ≥ 35 and ≤45 mmHg. The QI data were used to derive benchmarks using the Achievable Benchmark of Care (ABC™) methodology to identify the incidence of QIs at the best performing centers. Five thousand four hundred and sixty-five procedures were evaluated to derive QI and benchmark data. The incidence of the blood glucose QI ranged from 37–96% of procedures, with a benchmark value of 90%. The arterial outlet temperature QI occurred in 16–98% of procedures with the benchmark of 94%; while the arterial pCO2 QI occurred in 21–91%, with the benchmark value of 80%. We have derived QIs and benchmark calculations for the management of several key aspects of cardiopulmonary bypass to provide a platform for improving the quality of perfusion practice. PMID:22730861

  18. A Phantom Tissue System for the Calibration of Perfusion Measurements

    PubMed Central

    Mudaliar, Ashvinikumar V.; Ellis, Brent E.; Ricketts, Patricia L.; Lanz, Otto I.; Scott, Elaine P.; Diller, Thomas E.

    2008-01-01

    A convenient method for testing and calibrating surface perfusion sensors has been developed. A phantom tissue model is used to simulate the nondirectional blood flow of tissue perfusion. A computational fluid dynamics (CFD) model was constructed in Fluent® to design the phantom tissue and validate the experimental results. The phantom perfusion system was used with a perfusion sensor based on clearance of thermal energy. A heat flux gage measures the heat flux response of tissue when a thermal event (convective cooling) is applied. The blood perfusion and contact resistance are estimated by a parameter estimation code. From the experimental and analytical results, it was concluded that the probe displayed good measurement repeatability and sensitivity. The experimental perfusion measurements in the tissue were in good agreement with those of the CFD models and demonstrated the value of the phantom tissue system. PMID:19045509

  19. Long-term trajectories of the human appropriation of net primary production: Lessons from six national case studies

    PubMed Central

    Krausmann, Fridolin; Gingrich, Simone; Haberl, Helmut; Erb, Karl-Heinz; Musel, Annabella; Kastner, Thomas; Kohlheb, Norbert; Niedertscheider, Maria; Schwarzlmüller, Elmar

    2012-01-01

    The ‘human appropriation of net primary production’ (HANPP) is an integrated socio-ecological indicator measuring effects of land use on ecological biomass flows. Based on published data for Austria, Hungary, the Philippines, South Africa, Spain and the UK, this paper investigates long-term trends in aboveground HANPP and discusses the relations between population, economic growth, changes in biomass use and land-use intensity and their influences on national HANPP trajectories. During early stages of industrialization, population growth and increasing demand for biomass drive land-cover change, often resulting in deforestation, which raises HANPP. During later stages, industrialization of agriculture boosts agricultural yields often faster than biomass demand grows, resulting in stable or even declining HANPP. Technological change improves agricultural area-efficiency (biomass provision per unit area), thereby decoupling population and economic growth from HANPP. However, these efficiency gains require large inputs of fossil fuels and agrochemicals resulting in pressures on ecosystems and emissions. Our findings corroborate the argument that HANPP alone cannot – as sometimes suggested – be used as a simple measure of carrying capacity. Nevertheless, analyses of long-term HANPP trajectories in combination with accounts of material and energy flows can provide important insights into the sustainability of land use, thereby helping to understand limits to growth. PMID:23565034

  20. Thymic output, T-cell diversity, and T-cell function in long-term human SCID chimeras

    PubMed Central

    Win, Chan M.; Parrott, Roberta E.; Cooney, Myriah; Moser, Barry K.; Roberts, Joseph L.; Sempowski, Gregory D.; Buckley, Rebecca H.

    2009-01-01

    Severe combined immunodeficiency (SCID) is a syndrome of diverse genetic cause characterized by profound deficiencies of T, B, and sometimes NK-cell function. Nonablative human leukocyte antigen–identical or rigorously T cell–depleted haploidentical parental bone marrow transplantation (BMT) results in thymus-dependent genetically donor T-cell development in the recipients, leading to long-term survival. We reported previously that normal T-cell numbers, function, and repertoire developed by 3 to 4 months after transplantation in SCID patients, and the repertoire remained highly diverse for the first 10 years after BMT. The T-cell receptor diversity positively correlated with T-cell receptor excision circle levels, a reflection of thymic output. However, the fate of thymic function in SCID patients beyond 10 to 12 years after BMT remained to be determined. In this greater than 25-year follow-up study of 128 patients with 11 different molecular types of SCID after nonconditioned BMT, we provide evidence that T-cell function, thymic output, and T-cell clonal diversity are maintained long-term. PMID:19433858

  1. Dynamics of the human linear vestibulo-ocular reflex at medium frequency and modification by short-term training

    NASA Technical Reports Server (NTRS)

    Shelhamer, M.; Roberts, D. C.; Zee, D. S.

    2000-01-01

    We study here the effect of a short-term training paradigm on the gain and phase of the human translational VOR (the linear VOR: LVOR). Subjects were exposed to lateral sinusoidal translations on a sled, at 0.5 Hz, 0.3 g peak acceleration. With subjects tracking a remembered target at 1.2 m, the LVOR (slow-phase) under these conditions typically has a phase lead or lag, and a gain that falls short of compensatory. To induce short-term adaptation (training), we presented an earth-fixed visual scene at 1.2 m during sinusoidal translation (x 1 viewing) for 20 minutes, so as to drive the LVOR toward compensatory phase and gain. We examined both the slow-phase and the saccadic responses to these stimuli. Testing after training showed changes in slow-component gain and phase which were mostly but not always in the compensatory direction. These changes were more consistent in naive subjects than in subjects who had previous LVOR experience. Changes in gain were seen with step as well as sinusoidal test stimuli; gain changes were not correlated with vergence changes. There was a strong correlation between gain changes and phase changes across subjects. Fast phases (catch-up saccades) formed a large component of the LVOR under our testing conditions (approximately 30% of the changes in gain but not in phase due to training.

  2. Long-Term Balancing Selection in LAD1 Maintains a Missense Trans-Species Polymorphism in Humans, Chimpanzees, and Bonobos.

    PubMed

    Teixeira, João C; de Filippo, Cesare; Weihmann, Antje; Meneu, Juan R; Racimo, Fernando; Dannemann, Michael; Nickel, Birgit; Fischer, Anne; Halbwax, Michel; Andre, Claudine; Atencia, Rebeca; Meyer, Matthias; Parra, Genís; Pääbo, Svante; Andrés, Aida M

    2015-05-01

    Balancing selection maintains advantageous genetic and phenotypic diversity in populations. When selection acts for long evolutionary periods selected polymorphisms may survive species splits and segregate in present-day populations of different species. Here, we investigate the role of long-term balancing selection in the evolution of protein-coding sequences in the Homo-Pan clade. We sequenced the exome of 20 humans, 20 chimpanzees, and 20 bonobos and detected eight coding trans-species polymorphisms (trSNPs) that are shared among the three species and have segregated for approximately 14 My of independent evolution. Although the majority of these trSNPs were found in three genes of the major histocompatibility locus cluster, we also uncovered one coding trSNP (rs12088790) in the gene LAD1. All these trSNPs show clustering of sequences by allele rather than by species and also exhibit other signatures of long-term balancing selection, such as segregating at intermediate frequency and lying in a locus with high genetic diversity. Here, we focus on the trSNP in LAD1, a gene that encodes for Ladinin-1, a collagenous anchoring filament protein of basement membrane that is responsible for maintaining cohesion at the dermal-epidermal junction; the gene is also an autoantigen responsible for linear IgA disease. This trSNP results in a missense change (Leucine257Proline) and, besides altering the protein sequence, is associated with changes in gene expression of LAD1. PMID:25605789

  3. Long-term trajectories of the human appropriation of net primary production: Lessons from six national case studies.

    PubMed

    Krausmann, Fridolin; Gingrich, Simone; Haberl, Helmut; Erb, Karl-Heinz; Musel, Annabella; Kastner, Thomas; Kohlheb, Norbert; Niedertscheider, Maria; Schwarzlmüller, Elmar

    2012-05-01

    The 'human appropriation of net primary production' (HANPP) is an integrated socio-ecological indicator measuring effects of land use on ecological biomass flows. Based on published data for Austria, Hungary, the Philippines, South Africa, Spain and the UK, this paper investigates long-term trends in aboveground HANPP and discusses the relations between population, economic growth, changes in biomass use and land-use intensity and their influences on national HANPP trajectories. During early stages of industrialization, population growth and increasing demand for biomass drive land-cover change, often resulting in deforestation, which raises HANPP. During later stages, industrialization of agriculture boosts agricultural yields often faster than biomass demand grows, resulting in stable or even declining HANPP. Technological change improves agricultural area-efficiency (biomass provision per unit area), thereby decoupling population and economic growth from HANPP. However, these efficiency gains require large inputs of fossil fuels and agrochemicals resulting in pressures on ecosystems and emissions. Our findings corroborate the argument that HANPP alone cannot - as sometimes suggested - be used as a simple measure of carrying capacity. Nevertheless, analyses of long-term HANPP trajectories in combination with accounts of material and energy flows can provide important insights into the sustainability of land use, thereby helping to understand limits to growth. PMID:23565034

  4. Long-term safety and function of RPE from human embryonic stem cells in preclinical models of macular degeneration.

    PubMed

    Lu, Bin; Malcuit, Christopher; Wang, Shaomei; Girman, Sergej; Francis, Peter; Lemieux, Linda; Lanza, Robert; Lund, Raymond

    2009-09-01

    Assessments of safety and efficacy are crucial before human ESC (hESC) therapies can move into the clinic. Two important early potential hESC applications are the use of retinal pigment epithelium (RPE) for the treatment of age-related macular degeneration and Stargardt disease, an untreatable form of macular dystrophy that leads to early-onset blindness. Here we show long-term functional rescue using hESC-derived RPE in both the RCS rat and Elov14 mouse, which are animal models of retinal degeneration and Stargardt, respectively. Good Manufacturing Practice-compliant hESC-RPE survived subretinal transplantation in RCS rats for prolonged periods (>220 days). The cells sustained visual function and photoreceptor integrity in a dose-dependent fashion without teratoma formation or untoward pathological reactions. Near-normal functional measurements were recorded at >60 days survival in RCS rats. To further address safety concerns, a Good Laboratory Practice-compliant study was carried out in the NIH III immune-deficient mouse model. Long-term data (spanning the life of the animals) showed no gross or microscopic evidence of teratoma/tumor formation after subretinal hESC-RPE transplantation. These results suggest that hESCs could serve as a potentially safe and inexhaustible source of RPE for the efficacious treatment of a range of retinal degenerative diseases. PMID:19521979

  5. Isotropic Versus Bipolar Functionalized Biomimetic Artificial Basement Membranes and Their Evaluation in Long-Term Human Cell Co-Culture.

    PubMed

    Rossi, Angela; Wistlich, Laura; Heffels, Karl-Heinz; Walles, Heike; Groll, Jürgen

    2016-08-01

    In addition to dividing tissues into compartments, basement membranes are crucial as cell substrates and to regulate cellular behavior. The development of artificial basement membranes is indispensable for the ultimate formation of functional engineered tissues; however, pose a challenge due to their complex structure. Herein, biodegradable electrospun polyester meshes are presented, exhibiting isotropic or bipolar bioactivation as a biomimetic and biofunctional model of the natural basement membrane. In a one-step preparation process, reactive star-shaped prepolymer additives, which generate a hydrophilic fiber surface, are electrospun with cell-adhesion-mediating peptides, derived from major components of the basement membrane. Human skin cells adhere to the functionalized meshes, and long-term co-culture experiments confirm that the artificial basement membranes recapitulate and preserve tissue specific functions. Several layers of immortalized human keratinocytes grow on the membranes, differentiating toward the surface and expressing typical epithelial markers. Fibroblasts migrate into the reticular lamina mimicking part of the mesh. Both cells types begin to produce extracellular matrix proteins and to remodel the initial membrane. It is shown at the example of skin that the artificial basement membrane design provokes biomimetic responses of different cell types and can thus be used as basis for the future development of basement membrane containing tissues. PMID:27283510

  6. Long-term, stable differentiation of human embryonic stem cell-derived neural precursors grafted into the adult mammalian neostriatum.

    PubMed

    Nasonkin, Igor; Mahairaki, Vasiliki; Xu, Leyan; Hatfield, Glen; Cummings, Brian J; Eberhart, Charles; Ryugo, David K; Maric, Dragan; Bar, Eli; Koliatsos, Vassilis E

    2009-10-01

    Stem cell grafts have been advocated as experimental treatments for neurological diseases by virtue of their ability to offer trophic support for injured neurons and, theoretically, to replace dead neurons. Human embryonic stem cells (HESCs) are a rich source of neural precursors (NPs) for grafting, but have been questioned for their tendency to form tumors. Here we studied the ability of HESC-derived NP grafts optimized for cell number and differentiation stage prior to transplantation, to survive and stably differentiate and integrate in the basal forebrain (neostriatum) of young adult nude rats over long periods of time (6 months). NPs were derived from adherent monolayer cultures of HESCs exposed to noggin. After transplantation, NPs showed a drastic reduction in mitotic activity and an avid differentiation into neurons that projected via major white matter tracts to a variety of forebrain targets. A third of NP-derived neurons expressed the basal forebrain-neostriatal marker dopamine-regulated and cyclic AMP-regulated phosphoprotein. Graft-derived neurons formed mature synapses with host postsynaptic structures, including dendrite shafts and spines. NPs inoculated in white matter tracts showed a tendency toward glial (primarily astrocytic) differentiation, whereas NPs inoculated in the ventricular epithelium persisted as nestin(+) precursors. Our findings demonstrate the long-term ability of noggin-derived human NPs to structurally integrate tumor-free into the mature mammalian forebrain, while maintaining some cell fate plasticity that is strongly influenced by particular central nervous system (CNS) niches. PMID:19609935

  7. Glucocorticoid receptor signaling contributes to constitutive activation of the noncanonical NF-κB pathway in term human placenta.

    PubMed

    Wang, Bingbing; Palomares, Kristy; Parobchak, Nataliya; Cece, John; Rosen, Max; Nguyen, Anh; Rosen, Todd

    2013-02-01

    Our recent study demonstrated that constitutively activated RelB/NF-κB2 positively regulates the CRH in the human placenta. In the current study, we explored the role of the glucocorticoid receptor (GR) signaling in constitutive activation of the noncanonical NF-κB pathway. A glucocorticoid response element (GRE) motif search suggests that both NF-κB inducing kinase (NIK) and RelB genes, which are key regulators of the noncanonical NF-κB pathway, have a putative GRE within their promoter, approximately 1 kb upstream from the transcription start site. By using chromatin immunoprecipitation assay we identified that the GR and phosphorylated GR at Ser211 were associated with the GREs of both NIK and RelB. Dexamethasone stimulated expression of NIK, RelB, NF-κB2 as well as CRH and cyclooxygenase-2 (COX-2). Repression of GR by short interfering RNA resulted in inhibition of NIK, RelB, NF-κB2, CRH, and COX-2. In addition, depletion of GR attenuated glucocorticoid-mediated up-regulation of NIK, RelB, NF-κB2, CRH, and COX-2. Furthermore, siRNA specifically targeting NIK down-regulated CRH and COX-2. Taken together, these results suggest that constitutive activation of the noncanonical NF-κB pathway in term human placenta is driven by the GR signaling, which in turn up-regulates placental CRH and other NF-κB-responsive genes. PMID:23239753

  8. Persistence of X-ray-induced chromosomal rearrangements in long-term cultures of human diploid fibroblasts

    SciTech Connect

    Kano, Y.; Little, J.B.

    1984-09-01

    As part of a long-term study of mechanisms of human cell neoplastic transformation, the authors have examined the change in the frequencies of X-ray-induced chromosome rearrangements in density-inhibited human foreskin fibroblasts as a function of subculture time. In nonproliferating cells, the frequency of chromosomal aberrations declined within 24 to 48 hr but still remained at a relatively high level up to 43 days after irradiation. Aberrations disappeared rapidly, however, when the cells were allowed to proliferate, indicating that these lesions are lethal to dividing cells. The frequency of induced translocations, as determined by analysis of G-banded karyotypes, was dose dependent and remained stable up to 20 mean population doublings after irradiation. When subculture of density-inhibited cultures was delayed for 4 hr after irradiation (confluent holding), the frequency of chromosomal aberrations in the first mitosis declined, whereas the translocation frequencies at later passage were elevated as compared with cells subcultured immediately. This correlates with the reported increase in the frequency of transformation under similar conditions. These findings support the hypothesis that chromosomal rearrangements induced by DNA damage may be involved in the initiation of cancer.

  9. Long-Term, Stable Differentiation Of Human Embryonic Stem Cell-Derived Neural Precursors Grafted Into The Adult Mammalian Neostriatum

    PubMed Central

    Nasonkin, I.; Mahairaki, V.; Xu, L.; Hatfield, G.; Cummings, B.J.; Eberhart, C.; Ryugo, D.; Maric, D.; Bar, E.; Koliatsos, V.E.

    2010-01-01

    Stem-cell grafts have been advocated as experimental treatments for neurological diseases by virtue of their ability to offer trophic support for injured neurons and, theoretically, to replace dead neurons. Human embryonic stem cells (HESCs) are a rich source of neural precursors (NPs) for grafting, but have been questioned for their tendency to form tumors. Here we studied the ability of HESC-derived NP grafts optimized for cell number and differentiation stage prior to transplantation, to survive and stably differentiate and integrate in the basal forebrain (neostriatum) of young adult nude rats over long periods of time (6 months). NPs were derived from adherent monolayer cultures of HESCs exposed to noggin. After transplantation, NPs showed a drastic reduction in mitotic activity and an avid differentiation into neurons that projected via major white matter tracts to a variety of forebrain targets. A third of NP-derived neurons expressed the basal forebrain-neostriatal marker Dopamine- and cyclic AMP-Regulated Phosphoprotein. Graft-derived neurons formed mature synapses with host post-synaptic structures, including dendrite shafts and spines. NPs inoculated in white matter tracts showed a tendency towards glial (primarily astrocytic) differentiation, whereas NPs inoculated in the ventricular epithelium persisted as nestin (+) precursors. Our findings demonstrate the long-term ability of noggin-derived human NPs to structurally integrate tumor-free into the mature mammalian forebrain, while maintaining some cell fate plasticity that is strongly influenced by particular CNS niches. PMID:19609935

  10. Short and long term gene expression variation and networking in human proximal tubule cells when exposed to cadmium

    PubMed Central

    2013-01-01

    Cadmium (Cd2+) is a known nephrotoxin causing tubular necrosis during acute exposure and potentially contributing to renal failure in chronic long-term exposure. To investigate changes in global gene expression elicited by cadmium, an in-vitro exposure system was developed from cultures of human renal epithelial cells derived from cortical tissue obtained from nephrectomies. These cultures exhibit many of the qualities of proximal tubule cells. Using these cells, a study was performed to determine the cadmium-induced global gene expression changes after short-term (1 day, 9, 27, and 45 μM) and long-term cadmium exposure (13 days, 4.5, 9, and 27 μM). These studies revealed fundamental differences in the types of genes expressed during each of these time points. The obtained data was further analyzed using regression to identify cadmium toxicity responsive genes. Regression analysis showed 403 genes were induced and 522 genes were repressed by Cd2+ within 1 day, and 366 and 517 genes were induced and repressed, respectively, after 13 days. We developed a gene set enrichment analysis method to identify the cadmium induced pathways that are unique in comparison to traditional approaches. The perturbation of global gene expression by various Cd2+ concentrations and multiple time points enabled us to study the transcriptional dynamics and gene interaction using a mutual information-based network model. The most prominent network module consisted of INHBA, KIF20A, DNAJA4, AKAP12, ZFAND2A, AKR1B10, SCL7A11, and AKR1C1. PMID:23369406

  11. A Melodic Contour Repeatedly Experienced by Human Near-Term Fetuses Elicits a Profound Cardiac Reaction One Month after Birth

    PubMed Central

    Granier-Deferre, Carolyn; Bassereau, Sophie; Ribeiro, Aurélie; Jacquet, Anne-Yvonne; DeCasper, Anthony J.

    2011-01-01

    Background Human hearing develops progressively during the last trimester of gestation. Near-term fetuses can discriminate acoustic features, such as frequencies and spectra, and process complex auditory streams. Fetal and neonatal studies show that they can remember frequently recurring sounds. However, existing data can only show retention intervals up to several days after birth. Methodology/Principal Findings Here we show that auditory memories can last at least six weeks. Experimental fetuses were given precisely controlled exposure to a descending piano melody twice daily during the 35th, 36th, and 37th weeks of gestation. Six weeks later we assessed the cardiac responses of 25 exposed infants and 25 naive control infants, while in quiet sleep, to the descending melody and to an ascending control piano melody. The melodies had precisely inverse contours, but similar spectra, identical duration, tempo and rhythm, thus, almost identical amplitude envelopes. All infants displayed a significant heart rate change. In exposed infants, the descending melody evoked a cardiac deceleration that was twice larger than the decelerations elicited by the ascending melody and by both melodies in control infants. Conclusions/Significance Thus, 3-weeks of prenatal exposure to a specific melodic contour affects infants ‘auditory processing’ or perception, i.e., impacts the autonomic nervous system at least six weeks later, when infants are 1-month old. Our results extend the retention interval over which a prenatally acquired memory of a specific sound stream can be observed from 3–4 days to six weeks. The long-term memory for the descending melody is interpreted in terms of enduring neurophysiological tuning and its significance for the developmental psychobiology of attention and perception, including early speech perception, is discussed. PMID:21383836

  12. Methylation status and transcriptional expression of the MHC class I loci in human trophoblast cells from term placenta

    SciTech Connect

    Guillaudeux, T.; Rodriguez, A.M.; Girr, M.

    1995-04-01

    Of the various molecular regulatory mechanisms that may be used by human trophoblast cells to down-regulate expression of HLA class I genes, we chose to investigate the methylation of DNA, generally associated with inhibition of transcription. We analyzed the methylation status of different HLA class I loci in villous and extravillous cytotrophoblast cells and in vitro-differentiated syncytiotrophoblast, purified from human term placenta, as well as in the human trophoblast-derived JAR and JEG-3 cell lines. We then compared methylation status and transcriptional activity. An inverse relationship was established between JAR and JEG-3: HLA-A, -B, and -G are methylated and repressed in JAR, whereas in JEG-3, HLA-A is methylated and repressed but HLA-B and -G are partially methylated and transcribed. HLA-E is unmethylated and transcribed in both cell lines. Apart from HLA-E, which is always unmethylated and transcribed, no such relationship exists for the other class I loci in trophoblast cells. Whereas nonclassical HLA-G and classical HLA-A and -B class I genes are undermethylated in both cytotrophoblast and syncytiotrophoblast, they are clearly transcribed in the former but minimally transcribed in the latter subpopulation. Thus, the down-regulation of class I gene expression in the in vitro-differentiated synctiotrophoblast is unlikely to be caused by DNA methylation. Furthermore, there is no detectable expression of any class I molecule at the cell surface of either trophoblast cell subpopulation, suggesting a negative control on translation and/or on the secretory pathway to the plasma membrane. 50 refs., 11 figs., 1 tab.

  13. Measurement of continuous distributions of ventilation-perfusion ratios - Theory

    NASA Technical Reports Server (NTRS)

    Wagner, P. D.; Saltzman, H. A.; West, J. B.

    1974-01-01

    The resolution of the technique considered is sufficient to describe smooth distributions containing blood flow to unventilated regions (shunt), ventilation to unperfused regions (dead space), and up to three additional modes over the range of finite ventilation-perfusion ratios. In particular, areas whose ventilation-perfusion ratios are low can be separated from unventilated regions and those whose ventilation-perfusion ratios are high can similarly be distinguished from unperfused areas.

  14. Scintigraphic perfusion patterns in patients with diffuse lung disease

    SciTech Connect

    Newman, G.E.; Sullivan, D.C.; Gottschalk, A.; Putman, C.E.

    1982-04-01

    Perfusion scintigrams of 55 patients with radiographic evidence of diffuse lung disease were reviewed. Thirty-nine had acute and/or chronic changes caused by congestive heart failure, and 16 had diffuse reticulonodular disease. A normal or near-normal perfusion pattern was seen in 40/55 (73%), and this finding was equally common in the two groups. The authors conclude that perfusion scintigraphy is useful in excluding pulmonary embolism in patients with radiographic evidence of diffuse, symmetrical lung disease.

  15. A method of thymic perfusion and its evaluation

    PubMed Central

    Ekwueme, O.

    1973-01-01

    The development and evaluation of a method of isolated ex vivo perfusion of the rabbit thymus using diluted autologous blood is described. The data indicate that the viability of the preparation is maintained at a satisfactory level during the period of perfusion. These results suggest that the isolated perfused thymus would be a useful new approach to studies of thymus function. ImagesFig. 2Fig. 8Fig. 9Fig. 10Fig. 11 PMID:4747584

  16. Perfusion Scintigraphy and Patient Selection for Lung Volume Reduction Surgery

    PubMed Central

    Chandra, Divay; Lipson, David A.; Hoffman, Eric A.; Hansen-Flaschen, John; Sciurba, Frank C.; DeCamp, Malcolm M.; Reilly, John J.; Washko, George R.

    2010-01-01

    Rationale: It is unclear if lung perfusion can predict response to lung volume reduction surgery (LVRS). Objectives: To study the role of perfusion scintigraphy in patient selection for LVRS. Methods: We performed an intention-to-treat analysis of 1,045 of 1,218 patients enrolled in the National Emphysema Treatment Trial who were non–high risk for LVRS and had complete perfusion scintigraphy results at baseline. The median follow-up was 6.0 years. Patients were classified as having upper or non–upper lobe–predominant emphysema on visual examination of the chest computed tomography and high or low exercise capacity on cardiopulmonary exercise testing at baseline. Low upper zone perfusion was defined as less than 20% of total lung perfusion distributed to the upper third of both lungs as measured on perfusion scintigraphy. Measurements and Main Results: Among 284 of 1,045 patients with upper lobe–predominant emphysema and low exercise capacity at baseline, the 202 with low upper zone perfusion had lower mortality with LVRS versus medical management (risk ratio [RR], 0.56; P = 0.008) unlike the remaining 82 with high perfusion where mortality was unchanged (RR, 0.97; P = 0.62). Similarly, among 404 of 1,045 patients with upper lobe–predominant emphysema and high exercise capacity, the 278 with low upper zone perfusion had lower mortality with LVRS (RR, 0.70; P = 0.02) unlike the remaining 126 with high perfusion (RR, 1.05; P = 1.00). Among the 357 patients with non–upper lobe–predominant emphysema (75 with low and 282 with high exercise capacity) there was no improvement in survival with LVRS and measurement of upper zone perfusion did not contribute new prognostic information. Conclusions: Compared with optimal medical management, LVRS reduces mortality in patients with upper lobe–predominant emphysema when there is low rather than high perfusion to the upper lung. PMID:20538961

  17. Plastination and its importance in teaching anatomy. Critical points for long-term preservation of human tissue.

    PubMed

    Riederer, Beat M

    2014-03-01

    Most medical curricula rely on human bodies for teaching macroscopic anatomy. Over the past 20 years, plastination has become an important means of preservation of organs, for well dissected specimens or for body slices. Here, several critical points regarding body donation with legal and ethical considerations for long-term preservation, the use of cadavers in teaching and the preparation of plastinates as an additional teaching tool will be discussed. Silicone S10 is the gold standard in the preparation of plastinates. An important point to respect is the preparation of specimens, since only very well dissected body parts or excellent tissue sections should be plastinated to show the extraordinary aspects of the human anatomy. The preparation of thin and transparent sections and preservation with P40 polyester provides an additional technique to prepare resistant body slices. A selection of samples prepared by S10 and P40 are shown and compared. In addition, Prussian or Berlin blue staining of brain slices is shown to discriminate better between gray and white matter and demonstrate neuroanatomical structures. These plastinates have been used for many years in teaching first- and second-year medical students and have not lost their appeal. Students and staff appreciate the use of such plastinates. One of the advantages is that their use is not restricted to the dissection hall; slices and body parts can be used in any lecture room or in small group teaching. Therefore, ethical and legal questions need to be addressed regarding their specific use. Plastinates do not replace the traditional dissection courses, since students learn best the anatomical features of a given region by hands-on dissection and by exploratory anatomy. Furthermore, plastinates are more rigid and do not allow demonstration of hidden structures; they also become more cumbersome for endoscopy or are too rigid for demonstrating mechanical features of joints. However, although not a replacement

  18. Plastination and its importance in teaching anatomy. Critical points for long-term preservation of human tissue*

    PubMed Central

    Riederer, Beat M

    2014-01-01

    Most medical curricula rely on human bodies for teaching macroscopic anatomy. Over the past 20 years, plastination has become an important means of preservation of organs, for well dissected specimens or for body slices. Here, several critical points regarding body donation with legal and ethical considerations for long-term preservation, the use of cadavers in teaching and the preparation of plastinates as an additional teaching tool will be discussed. Silicone S10 is the gold standard in the preparation of plastinates. An important point to respect is the preparation of specimens, since only very well dissected body parts or excellent tissue sections should be plastinated to show the extraordinary aspects of the human anatomy. The preparation of thin and transparent sections and preservation with P40 polyester provides an additional technique to prepare resistant body slices. A selection of samples prepared by S10 and P40 are shown and compared. In addition, Prussian or Berlin blue staining of brain slices is shown to discriminate better between gray and white matter and demonstrate neuroanatomical structures. These plastinates have been used for many years in teaching first-and second-year medical students and have not lost their appeal. Students and staff appreciate the use of such plastinates. One of the advantages is that their use is not restricted to the dissection hall; slices and body parts can be used in any lecture room or in small group teaching. Therefore, ethical and legal questions need to be addressed regarding their specific use. Plastinates do not replace the traditional dissection courses, since students learn best the anatomical features of a given region by hands-on dissection and by exploratory anatomy. Furthermore, plastinates are more rigid and do not allow demonstration of hidden structures; they also become more cumbersome for endoscopy or are too rigid for demonstrating mechanical features of joints. However, although not a replacement

  19. The absolute CBF response to activation is preserved during elevated perfusion: Implications for neurovascular coupling measures

    PubMed Central

    Whittaker, Joseph R.; Driver, Ian D.; Bright, Molly G.; Murphy, Kevin

    2016-01-01

    Functional magnetic resonance imaging (fMRI) techniques in which the blood oxygenation level dependent (BOLD) and cerebral blood flow (CBF) response to a neural stimulus are measured, can be used to estimate the fractional increase in the cerebral metabolic rate of oxygen consumption (CMRO2) that accompanies evoked neural activity. A measure of neurovascular coupling is obtained from the ratio of fractional CBF and CMRO2 responses, defined as n, with the implicit assumption that relative rather than absolute changes in CBF and CMRO2 adequately characterise the flow-metabolism response to neural activity. The coupling parameter n is important in terms of its effect on the BOLD response, and as potential insight into the flow-metabolism relationship in both normal and pathological brain function. In 10 healthy human subjects, BOLD and CBF responses were measured to test the effect of baseline perfusion (modulated by a hypercapnia challenge) on the coupling parameter n during graded visual stimulation. A dual-echo pulsed arterial spin labelling (PASL) sequence provided absolute quantification of CBF in baseline and active states as well as relative BOLD signal changes, which were used to estimate CMRO2 responses to the graded visual stimulus. The absolute CBF response to the visual stimuli were constant across different baseline CBF levels, meaning the fractional CBF responses were reduced at the hyperperfused baseline state. For the graded visual stimuli, values of n were significantly reduced during hypercapnia induced hyperperfusion. Assuming the evoked neural responses to the visual stimuli are the same for both baseline CBF states, this result has implications for fMRI studies that aim to measure neurovascular coupling using relative changes in CBF. The coupling parameter n is sensitive to baseline CBF, which would confound its interpretation in fMRI studies where there may be significant differences in baseline perfusion between groups. The absolute change in

  20. Extracorporeal Free Flap Perfusion in Case of Prolonged Ischemia Time

    PubMed Central

    Präbst, K.; Beier, J. P.; Meyer, A.; Horch, R. E.

    2016-01-01

    Summary: In free flap surgery, a clinically established concept still has to be found for the reduction of ischemia-related cell damage in the case of prolonged ischemia. Although promising results using extracorporeal free flap perfusion in the laboratory have been published in the past, until now this concept has not yet paved its way into clinical routine. This might be due to the complexity of perfusion systems and a lack of standardized tools. Here, we want to present the results of the first extracorporeal free flap perfusion in a clinical setting using a simple approach without the application of a complex perfusion machinery. PMID:27200244

  1. New imaging technology: measurement of myocardial perfusion by contrast echocardiography

    NASA Technical Reports Server (NTRS)

    Rubin, D. N.; Thomas, J. D.

    2000-01-01

    Myocardial perfusion imaging has long been a goal for the non-invasive echocardiographic assessment of the heart. However, many factors at play in perfusion imaging have made this goal elusive. Harmonic imaging and triggered imaging with newer contrast agents have made myocardial perfusion imaging potentially practical in the very near future. The application of indicator dilution theory to the coronary circulation and bubble contrast agents is fraught with complexities and sources of error. Therefore, quantification of myocardial perfusion by non-invasive echocardiographic imaging requires further investigation in order to make this technique clinically viable.

  2. Perfusion CT imaging of the liver: review of clinical applications

    PubMed Central

    Oğul, Hayri; Kantarcı, Mecit; Genç, Berhan; Pirimoğlu, Berhan; Çullu, Neşat; Kızrak, Yeşim; Yılmaz, Ömer; Karabulut, Nevzat

    2014-01-01

    Perfusion computed tomography (CT) has a great potential for determining hepatic and portal blood flow; it offers the advantages of quantitative determination of lesion hemodynamics, distinguishing malignant and benign processes, as well as providing morphological data. Many studies have reported the use of this method in the assessment of hepatic tumors, hepatic fibrosis associated with chronic liver disease, treatment response following radiotherapy and chemotherapy, and hepatic perfusion changes after radiological or surgical interventions. The main goal of liver perfusion imaging is to improve the accuracy in the characterization of liver disorders. In this study, we reviewed the clinical application of perfusion CT in various hepatic diseases. PMID:24834487

  3. Radionuclide Tracers for Myocardial Perfusion Imaging and Blood Flow Quantification.

    PubMed

    deKemp, Robert A; Renaud, Jennifer M; Klein, Ran; Beanlands, Rob S B

    2016-02-01

    Myocardial perfusion imaging is performed most commonly using Tc-99m-sestamibi or tetrofosmin SPECT as well as Rb-82-rubidium or N-13-ammonia PET. Diseased-to-normal tissue contrast is determined by the tracer retention fraction, which decreases nonlinearly with flow. Reduced tissue perfusion results in reduced tracer retention, but the severity of perfusion defects is typically underestimated by 20% to 40%. Compared to SPECT, retention of the PET tracers is more linearly related to flow, and therefore, the perfusion defects are measured more accurately using N-13-ammonia or Rb-82. PMID:26590778

  4. Perfusion magnetic resonance imaging correlates of neuropsychological impairment in multiple sclerosis

    PubMed Central

    Inglese, Matilde; Adhya, Sumita; Johnson, Glyn; Babb, James S; Miles, Laura; Jaggi, Hina; Herbert, Joseph; Grossman, Robert I

    2008-01-01

    Although cognitive impairment is common in multiple sclerosis (MS), its pathophysiology is still poorly understood. Abnormalities of cerebral blood flow (CBF) have long been acknowledged in MS and advances in perfusion magnetic resonance imaging (MRI) allow for their assessment in vivo. We investigated the relationship between regional perfusion changes and neuropsychological (NP) dysfunctions in patients with relapsing-remitting and primary-progressive MS. Absolute CBF, cerebral blood volume (CBV) and mean transit time were measured in 32 MS patients and 11 healthy controls using dynamic susceptibility contrast-enhanced T2*-weighted MRI. A comprehensive NP test battery was administered to all patients. A mixed model analysis of covariance was performed for group comparisons in terms of perfusion measures in normal-appearing white matter (NAWM) and deep gray matter (GM). Pearson’s correlations were used to describe the association of perfusion metrics with NP Z-scores. CBF and CBV values were significantly decreased in both NAWM and deep GM in MS patients compared with controls (P = 0.01). In all patients, deep GM CBF was significantly associated with Rey Complex Figure Test (RCFT)-Copy (r = 0.5; P = 0.001) and deep GM CBV and NAWM CBV were significantly associated with Color-Word Interference Inhibition Switching test (D-KEFSIS) (r = 0.4; P = 0.008 and r = 0.4; P = 0.02). However, the only associations that remained significant after Bonferroni correction were between deep GM CBF and RCFT-Copy (P = 0.006), and deep GM CBV and D-KEFSIS (P = 0.04). Our results suggest a role for tissue perfusion impairment in NP dysfunction in MS. Large-scale studies are needed to characterize better this association. PMID:17473851

  5. In vitro perfusion of hybrid artificial pancreas devices at low flow rates.

    PubMed

    Ramírez, C A; López, M; Stephens, C L

    1992-01-01

    Type I diabetes is characterized by insulin insufficiency due to lack of functional beta cells. To replace injection therapy, schemes such as the Hybrid Artificial Pancreas (HAP) were developed. This consists of an acrylic housing enclosing a semipermeable hollow fiber membrane. Donor islets can be seeded in the annular space through a port in the housing, and thus are separated from the recipient's bloodstream or perfusate. Before scaling the HAP to human size, the dynamics of its insulin response to a perfusion glucose challenge must be better understood. In this study, the HAP's insulin response after a step increase in the lumenal glucose concentration was determined as a function of the radial thickness of the annular space (0.173-0.973 mm) and islet distribution at a flow rate of 1 ml/min. Devices containing a single, 65 mm long fiber were used. Rat islets were isolated using standard collagenase digestion techniques. In unseeded HAP perfusions, the washout time for glucose and insulin from the annular space was dependent on flow rate and radial thickness. Both solutes were removed in < 3 min from the smallest devices when perfused at 10 ml/min. Thus, solute transport within the HAP is very fast. In the seeded HAP perfusions, the devices were subjected to a step increase in the lumenal glucose concentration. Sequential samples of the HAP effluent were collected and assayed for glucose and insulin. The spatial distribution of the islets in the annular space was one of the most important factors in determining the HAP's insulin response.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1457899

  6. An anomaly of insulin removal in perfused livers of obese-hyperglycemic (ob/ob) mice.

    PubMed Central

    Karakash, C; Assimacopoulos-Jeannet, F; Jeanrenaud, B

    1976-01-01

    Obese-hyperglycemic (ob/ob) mice have the interesting feature of being hyperinsulinemic, thus having some characteristics in common with human maturity-onset diabetics. As the cause of hyperinsulinemia in these mice is not established, and as the liver is known to play a role in determining the amount of hormone that reaches the periphery, it was hypothesized that an anomaly in the hepatic handling of insulin might prevail in obese-hyperglycemic mice. Immunoreactive insulin was therefore measured in the perfusate before and after a single passage through perfused livers of lean and ob/ob mice, permitting. It was found that the removal of insulin by livers of lean mice increased with increasing concentrations of the hormone in the portal vein. The removal process had a limited capacity, however, and as a consequence the percentage of hormone removed by the liver actually decreased when portal insulin concentrations increased. Insulin removal by livers of ob/ob mice had qualitatively the same characteristics but was considerably less efficient than in normal livers. Due to this, more insulin was found in the perfusate leaving the liver of ob/9b mice than in that of controls, at any insulin concentration tested. These observations suggest that in obese-hyperglycemic mice more of the hormone may reach the periphery and thus contribute to hyperinsulinemia. The present study further suggests that the anomaly of insulin removal observed in perfused livers of ob/ob mice might be secondary to hyperinsulinemia, since it was partly corrected upon artificially decreasing the circulating levels of insulin (e.g. via a fast, anti-insulin serum, or streptozotocin treatment) before perfusion. The characteristics of hepatic insulin removal reported in this study, as well as the differences observed between livers of lean and ob/ob mice, may reflect changes in membrane insulin receptors and/or in processes responsible for the degradation of the horomone. PMID:1262459

  7. Rapid onset of perfused blood vessels after implantation of ECFCs and MPCs in collagen, PuraMatrix and fibrin provisional matrices.

    PubMed

    Allen, Patrick; Kang, Kyu-Tae; Bischoff, Joyce

    2015-05-01

    We developed an in vivo vascularization model in which human endothelial colony-forming cells (ECFCs) and human mesenchymal progenitor cells (MPCs) form blood vessel networks when co-injected (ECFC + MPC) into nude mice in rat tail type I collagen, bovine fibrin or synthetic peptide PuraMatrix matrices. We used three approaches to determine the onset of functional vascularization when ECFC + MPC suspended in these matrices were implanted in vivo. The first was immunohistochemistry to detect vessels lined by human endothelial cells and filled with red blood cells. The second was in vivo vascular staining by tail vein injection of a mixture of Ulex europaeus agglutinin I (UEA-I), a lectin specific for human endothelium, and Griffonia simplicifolia isolectin B4 (GS-IB4 ), a lectin specific for rodent endothelium. The third approach employed contrast-enhanced ultrasound to measure the perfusion volumes of implants in individual animals over time. Human endothelial-lined tubular structures were detected in vivo on days 1 and 2 after implantation, with perfused human vessels detected on days 3 and 4. Contrast-enhanced ultrasound revealed significant perfusion of ECFC + MPC/collagen implants on days 1-4, at up to 14% perfused vascular volume. ECFC + MPC implanted in fibrin and PuraMatrix matrices also supported perfusion at day 1, as assessed by ultrasound (at 12% and 23% perfused vascular volume, respectively). This model demonstrates that ECFC + MPC suspended in any of the three matrices initiated a rapid onset of vascularization. We propose that ECFC + MPC delivered in vivo provide a means to achieve rapid perfusion of tissue-engineered organs or for in situ tissue repair. PMID:23955835

  8. Assessment of myocardial perfusion and viability by positron emission tomography.

    PubMed

    Anagnostopoulos, Constantinos; Georgakopoulos, Alexandros; Pianou, Nikoletta; Nekolla, Stephan G

    2013-09-01

    An important evolution has taken place recently in the field of cardiovascular Positron Emission Tomography (PET) imaging. Being originally a highly versatile research tool that has contributed significantly to advance our understanding of cardiovascular physiology and pathophysiology, PET has gradually been incorporated into the clinical cardiac imaging portfolio contributing to diagnosis and management of patients investigated for coronary artery disease (CAD). PET myocardial perfusion imaging (MPI) has an average sensitivity and specificity around 90% for the detection of angiographically significant CAD and it is also a very accurate technique for prognostication of patients with suspected or known CAD. In clinical practice, Rubidium-82 ((82)Rb) is the most widely used radiopharmaceutical for MPI that affords also accurate and reproducible quantification in absolute terms (ml/min/g) comparable to that obtained by cyclotron produced tracers such as Nitrogen-13 ammonia ((13)N-ammonia) and Oxygen-15 labeled water ((15)O-water). Quantification increases sensitivity for detection of multivessel CAD and it may also be helpful for detection of early stages of atherosclerosis or microvascular dysfunction. PET imaging combining perfusion with myocardial metabolism using (18)F-Fluorodeoxyglucose ((18)F FDG), a glucose analog, is an accurate standard for assessment of myocardial hibernation and risk stratification of patients with left ventricular dysfunction of ischemic etiology. It is helpful for guiding management decisions regarding revascularization or medical treatment and predicting improvement of symptoms, exercise capacity and quality of life post-revascularization. The strengths of PET can be increased further with the introduction of hybrid scanners, which combine PET with computed tomography (PET/CT) or with magnetic resonance imaging (PET/MRI) offering integrated morphological, biological and physiological information and hence, comprehensive evaluation of