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Umbilical Vein (umbilical + vein)
Terms modified by Umbilical Vein Selected AbstractsPrenatal diagnosis of fetal intra-abdominal umbilical vein varix: Report of 2 casesJOURNAL OF CLINICAL ULTRASOUND, Issue 1 2008pek MD Abstract Fetal intra-abdominal umbilical vein varix (FIUVV) is a focal aneurysmal dilatation of the umbilical vein. Its clinical importance has not yet been clearly established, but it has been reported to be associated with increased fetal death rate (in nearly 44% of cases) and chromosomal abnormalities (in 12% of cases). We report 2 cases of FIUVV diagnosed via sonography in the third trimester. © 2007 Wiley Periodicals, Inc. J Clin Ultrasound, 2008 [source] Changes of serum melatonin level and its relationship to feto-placental unit during pregnancyJOURNAL OF PINEAL RESEARCH, Issue 1 2001Yasuhiko Nakamura Serum melatonin concentrations were studied in normal pregnant women and in women with several types of pathologic pregnancies, e.g., twins, preeclampsia or intrauterine growth retardation (IUGR). Blood samples were collected from the maternal antecubital vein at 14:00 hr (daytime) and 02:00 hr (nighttime) during pregnancy, and also from the umbilical vein and artery immediately after delivery. Serum melatonin concentrations were measured by radioimmunoassay. Daytime serum melatonin levels in normal (single fetus; singleton) pregnancies were low. While the levels showed an increasing tendency toward the end of pregnancy, no statistically significant changes occurred. On the other hand, the nighttime serum melatonin levels increased after 24 weeks of gestation, with significantly (P<0.01) high levels after 32 weeks; these values decreased to non-pregnant levels on the 2nd day of puerperium. Nighttime serum melatonin levels were significantly (P<0.05) higher in twin pregnancies after 28 weeks of gestation than in singleton pregnancies, whereas the patients with severe preeclampsia showed significantly (P<0.05) lower serum melatonin levels than the mild preeclampsia or the normal pregnant women after 32 weeks of gestation. Melatonin concentrations in umbilical vessels showed a higher tendency in neonates who were born during at night compared with the other neonates; moreover, those in the umbilical artery were generally higher than those in the umbilical vein. The present results indicate that in humans, the maternal serum melatonin levels show a diurnal rhythm, which increases until the end of pregnancy, reflecting some pathologic states of the feto-placental unit. Fetuses may produce melatonin with a circadian rhythm. [source] Dopamine modulates von Willebrand factor secretion in endothelial cells via D2,D4 receptorsJOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 7 2006S. ZAREI Summary.,Objective: von Willebrand factor (VWF) is acutely released from endothelial cells in response to numerous calcium-raising agents (e.g. thrombin, histamine) and cAMP-raising agents (e.g. epinephrine, adenosine, vasopressin). In contrast, very few inhibitors of endothelial VWF secretion have been described. The neurotransmitter dopamine is a modulator of exocytosis in several endocrine cells, and is possibly involved in the regulation of several endothelial cell functions. We therefore investigated the effect of dopamine on endothelial VWF secretion. Results: Dopamine, D2/D3- and D4-specific agonists inhibited histamine- but not thrombin-induced VWF secretion. Expression of dopamine D2, D3 and D4 receptors was demonstrated by reverse transcription polymerase chain reaction (RT-PCR) in both human aortic (HAEC) and umbilical vein (HUVEC) endothelial cells. D2,D4 agonists did not inhibit histamine-induced rise in [Ca2+]i: they inhibited histamine-induced secretion even in the absence of extracellular calcium. Thus, the dopamine effects are not mediated by [Ca2+]i -dependent signalling. D2/D3- and D4-specific agonists inhibited neither the rise in cAMP nor VWF secretion in response to epinephrine and adenosine, arguing against an effect on cAMP-mediated signalling. D1 and D5 receptors were not detected in HAEC or HUVEC by RT-PCR, and the D1/D5-specific agonist SKF 38 393 failed to modulate VWF secretion, arguing against a role for these receptors in endothelial exocytosis. Conclusions: Dopamine inhibits histamine-induced endothelial exocytosis by activating D2,D4 receptor, via a mechanism distinct from [Ca2+]i -or cAMP-mediated signaling. In contrast, D1 and D5 receptors are not functionally expressed in cultured endothelial cells. Dopamine agonists may be useful as inhibitors of endothelial activation in inflammation and cardiovascular disease. [source] Shiga toxin enhances functional tissue factor on human glomerular endothelial cells: implications for the pathophysiology of hemolytic uremic syndrome,JOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 4 2005E. NESTORIDI Summary.,Background:,The pathogenesis of Shiga toxin (Stx)-mediated childhood hemolytic uremic syndrome (HUS) is not fully delineated, although current evidence implicates a prothrombotic state. We hypothesized that the tissue factor (TF) pathway plays a major role in the pathophysiology of HUS. Materials and methods:,We measured cell surface TF activity in response to tumor necrosis factor-, (TNF-,) (20 ng mL,1, 2,144 h), Stx-1 (10,11 mol L,1, 4,144 h), or their combination (TNF-, 22 h and Stx-1 for the last 0.5,4 h of TNF-, incubation) on human glomerular (microvascular) endothelial cells (HGECs) and human umbilical vein (macrovascular) endothelial cells (HUVECs). Results and conclusions:,We observed that while TNF-, caused an increase in cell surface TF activity on both cell types, the combination of TNF-, and Stx-1 differentially affected HGECs. On these cells, TF activity was increased further by 2.67 ± 0.38-fold (n = 38, P < 0.001), consistent with our parallel observation that Stx-1 binds to HGECs but not to HUVECs. Anti-TF antibody abolished functional TF while anti-tissue factor pathway inhibitor antibody enhanced TF activity. Stx-1 alone did not induce TF activity on either cell type. Measurement of TF antigen levels and quantitative real-time polymerase chain reaction demonstrated that exposure to TNF-, markedly increased TF protein and TF mRNA for HGECs, but the exposure to the combination of TNF-, and Stx-1 did not increase further the amount of either TF protein or TF mRNA. We conclude that cytokine-activated HGECs, but not HUVECs, undergo a significant augmentation of cell surface TF activity following exposure to Stx, suggesting an important role for TF in the coagulopathy observed in HUS. [source] Venous outflow reconstruction with surgically reopened obliterated umbilical vein in domino liver transplantationLIVER TRANSPLANTATION, Issue 5 2007Hynek Mergental [source] Tailoring donor hepatectomy per segment 4 venous drainage in right lobe live donor liver transplantationLIVER TRANSPLANTATION, Issue 6 2004See Ching Chan Including the middle hepatic vein (MHV) in the right lobe liver graft for adult-to-adult live donor liver transplantation provides more functional liver by securing adequate venous drainage. Donor outcome of this procedure in relation to different venous drainage patterns of segment 4 is unknown. Modification of graft harvesting technique by preserving segment 4b hepatic vein (V4b) in theory compensates for unfavorable venous drainage patterns. Consecutive 120 right lobe live donors were included. Computed tomography was studied in detail to assign each donor to one of the three types of the Nakamura classification of venous drainage pattern of segment 4. Type I drainage was mainly via the left hepatic vein (LHV), type II drainage was equally into the MHV and LHV, and type III drainage was predominantly into the MHV. Any distinct umbilical vein was also noted. In the early part of the series, the V4b draining into the MHV was divided to provide a long MHV stump in the graft. In the later part of the series, prominent V4b draining into the MHV was preserved in the donor as far as possible. Donor outcomes were measured by peak values of prothrombin time (PT), serum bilirubin and transaminases levels. There was no donor mortality. Type I donors (n=69) had the best outcome with peak PT of 17.9 sec (range 12.3,23.3 sec). Type II donors (n=44) had peak PT of 18.5 sec (range 15.4,24.4 sec). When V4b was preserved in type II donors (n=19), the peak PT (18.0 sec, range 15.4,20.7 sec) became significantly lower than that of type II donors who had V4b sacrificed (20.3 sec, range 16.2,24.4 sec) (P=0.001). A distinct umbilical vein (n=91, 75.8%) was insignificant for donor outcome measured by peak PT. Multivariate analysis identified that type II donors with V4b sacrificed (n=25), type III donors (n=7), and the first 50 cases had less favorable outcomes. In conclusion, unfavorable venous drainage patterns were one of the independent factors compromising postoperative donor liver function, but was circumvented by preservation of V4b. (Liver Transpl 2004;10:755,762.) [source] Cortisol levels in umbilical vein and umbilical artery with or without antenatal corticosteroidsPEDIATRICS INTERNATIONAL, Issue 1 2005Masahiro Manabe Abstract,Background:,The developmental changes of the umbilical cortisol levels in neonates at gestational age of 23,41 weeks were studied and the effect of antenatal steroid administration on the umbilical cortisol levels were examined. Methods:,Cortisol levels in the umbilical vein (UV) and the umbilical artery (UA) were studied in 35 neonates at the gestational age (GA) of 23,41 weeks with or without antenatal administration of corticosteroids. Serum cortisol concentrations were measured by the high performance liquid chromatography method. Results:,The correlation between cortisol levels in UV and birthweight (BW) was weak and negative in premature infants. UV cortisol levels in the neonates with antenatal corticosteroid were lower than those in the neonates without antenatal corticosteroid, but the relation was not significant. The developmental changes of UV cortisol levels were the same as those in Murphy's study (spontaneous-onset labor). The cortisol levels in UV and UA had a significantly positive correlation and both had almost equal concentrations. There were no correlations between cortisol levels in UV and placental weight, Apgar Score at 1 and 5 min. Conclusions:,In the neonates whose birthweight was less than 2000 g without antenatal corticosteroid, there was a negative correlation between cortisol levels in UV and BW but there was no correlation between cortisol levels in UV and GA. That the neonates with antenatal corticosteroid would have a suppressed adrenocortical function after birth could not be proved. [source] Sacrococcygeal teratoma in a fetus with prenatally diagnosed partial trisomy 10q (10q24.3,qter) and partial monosomy 17p (p13.3,pter)PRENATAL DIAGNOSIS, Issue 4 2007Cem Batukan Abstract Objective Clinical features of the distal 10q trisomy syndrome consist of mental retardation, facial dysmorphism and renal and cardiac anomalies. The presence of a sacrococcygeal teratoma (SCT) in a fetus with distal 10q trisomy has not been reported yet. Methods A 33-year-old, G5, P2 woman with a singleton pregnancy was referred to our clinic at 24 weeks of gestation for further evaluation of a fetal sacral exophytic mass. Detailed fetal sonographic examination together with chromosomal analysis by amniocentesis was performed. Results The scan revealed a large SCT together with a persistent right umbilical vein, cardiomegaly, bilateral mild hydronephrosis and intrauterine growth retardation. The fetal karyotype showed distal 10q trisomy (10q24.3,qter) distal monosomy 17 (p13,pter). The fetus died after a preterm delivery at 28 weeks of gestation. Postnatal examination confirmed the prenatal findings and added the typical facial features of this syndrome, which consisted of prominent forehead, small nose with depressed nasal bridge, micrognathia and bow-shaped mouth. Conclusion This case provides further evidence of a possible association between chromosomal aberrations in SCTs. Copyright © 2007 John Wiley & Sons, Ltd. [source] Reference ranges for umbilical vein blood flow in the second half of pregnancy based on longitudinal dataPRENATAL DIAGNOSIS, Issue 2 2005Ganesh Acharya Abstract Objectives To construct new reference ranges for serial measurements of umbilical vein (UV) blood flow. Methods Prospective longitudinal study of blood flow velocities and diameter of the UV measured at four-weekly intervals during 19 to 42 weeks' gestation in 130 low-risk singleton pregnancies. Regression models and multilevel modeling were used to construct the reference ranges. Results On the basis of 511 sets of longitudinal observations, we established new reference percentiles of UV diameter, blood flow velocities, volume flow, and blood flow normalized for fetal weight and abdominal circumference. They reflected some of the developmental patterns of previous cross-sectional studies, but with important differences, particularly near term. The UV blood flow showed a continuous increase until term, whereas the flow normalized per unit fetal weight, a corresponding reduction. Calculating the blood flow on the basis of intensity-weighted mean velocity or 0.5 of the maximum velocity gave almost interchangeable results for most fetuses. Conclusion New reference ranges for UV blood flow based on longitudinal observations appear slightly different from cross-sectional studies, and should be more appropriate for serial evaluation of fetal circulation. Copyright © 2005 John Wiley & Sons, Ltd. [source] Prenatal diagnosis of ductus venosus agenesis and its association with cytogenetic/congenital anomaliesPRENATAL DIAGNOSIS, Issue 11 2002Paolo Volpe Abstract Objectives We present an observational study of 12 cases of anomalies of the umbilical and portal vein systems associated with absence of the ductus venosus (DV) diagnosed over the past 5 years. The hemodynamic implications of each pattern of umbilico-portal system anomalies associated with absence of the DV have been investigated, as well as the frequency and types of associated anomalies and their embryological origin. Methods In all cases ultrasound, color Doppler, and cytogenetic investigations were performed. Results Four main patterns of abnormal venous circulation were documented: (1) the umbilical vein (UV) bypasses the liver and drains into the right atrium directly or through a dilated coronary sinus (three cases); (2) the UV bypasses the liver, with an infrahepatic or suprahepatic connection directly to the inferior vena cava (IVC) (two cases); (3) the UV bypasses the liver and drains directly into the iliac or renal veins (four cases); and (4) the UV drains directly into the portal veins (three cases). Among seven cases with other associated anomalies (58%), there were three cases of Turner's and Noonan's syndromes. Two fetuses and two neonates died and there were two terminations of pregnancy (TOP). Conclusions In utero diagnosis of ultrasound patterns associated with DV anomalies is feasible. Fetal karyotyping should be considered, serial ultrasound examinations recommended and, in the presence of heart failure, delivery can be anticipated. Copyright © 2002 John Wiley & Sons, Ltd. [source] Vascular Development and Differentiation During Human Liver OrganogenesisTHE ANATOMICAL RECORD : ADVANCES IN INTEGRATIVE ANATOMY AND EVOLUTIONARY BIOLOGY, Issue 6 2008Sophie Collardeau-Frachon Abstract The vascular architecture of the human liver is established at the end of a complex embryological history. The hepatic primordium emerges at the 4th week and is in contact with two major venous systems of the fetal circulation: the vitelline veins and the umbilical veins. The fetal architecture of the afferent venous circulation of the liver is acquired between the 4th and the 6th week. At the end of this process, the portal vein is formed from several distinct segments of the vitelline veins; the portal sinus, deriving from the subhepatic intervitelline anastomosis, connects the umbilical vein, which is the predominant vessel of the fetal liver, to the portal system; the ductus venosus connects the portal sinus to the vena cava inferior. At birth, the umbilical vein and the ductus venosus collapse; the portal vein becomes the only afferent vein of the liver. The efferent venous vessels of the liver derive from the vitelline veins and are formed between the 4th and the 6th week. The hepatic artery forms at the 8th week; intrahepatic arterial branches progressively extend from the central to the peripheral areas of the liver between the 10th and the 15th week. Hepatic sinusoids appear very early, as soon as hepatic cords invade the septum transversum at the 4th week. They then progressively acquire their distinctive structural and functional characters, through a multistage process. Vascular development and differentiation during liver organogenesis is, therefore, a unique process; many of the cellular and molecular mechanisms involved remain poorly understood. Anat Rec, 291:614,627, 2008. © 2008 Wiley-Liss, Inc. [source] Brief Communication: No-Touch Hepatic Hilum Technique to Treat Early Portal Vein Thrombosis After Pediatric Liver TransplantationAMERICAN JOURNAL OF TRANSPLANTATION, Issue 9 2010J. Bueno A ,no-touch' hilum technique used to treat early portal vein complications post-liver transplantation in five children with body weight <10 kg is described. Four patients developed thrombosis and one portal flow absence secondary to collateral steal flow. A vascular sheath was placed through the previous laparotomy in the ileocolic vein (n = 2), inferior mesenteric vein (n = 1) or graft umbilical vein (n = 1). Portal clots were mechanically fragmented with balloon angioplasty. In addition, coil embolization of competitive collaterals (n = 3) and stent placement (n = 1) were performed. The catheter was left in place and exteriorized through the wound (n = 2) or a different transabdominal wall puncture (n = 3). A continuous transcatheter perfusion of heparin was subsequently administered. One patient developed recurrent thrombosis 24 h later which was resolved with the same technique. Catheters were removed surgically after a mean of 10.6 days. All patients presented portal vein patency at the end of follow-up. Three patients are alive after 5 months, 1.5 and 3.5 years, respectively; one patient required retransplantation 18 days postprocedure and the remaining patient died of adenovirus infection 2 months postprocedure. In conclusion, treatment of early portal vein complications following pediatric liver transplantation with this novel technique is feasible and effective. [source] Structural Differences in the Umbilical Vein Wall after Full-Term and Pre-term DeliveryANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 5 2009M. Bagyánszki Summary With the exception of its most proximal segment, the human umbilical cord lacks innervation. It might be expected, therefore, that a paracrine effect through the direct contact between the smooth muscle cells and the endothelium may be particularly important in the control of the fetoplacental circulation. In this study, electron microscopy and immunohistochemistry were applied to examine umbilical veins immediately after full-term and pre-term delivery. The smooth muscle cells in the upper layer of the tunica media exhibited long, foot-like processes with c-kit immunoreactivity. In the umbilical vein of full-term neonates more than 50% of these cell processes display a normal ultrastructure and they were closely associated with the lamina elastica interna. Whereas in pre-term infants more than 60% of these cell processes exhibit signs of severe shrinkage and detachedness from the lamina elastica interna. At the same time, the high level of immunoreactivity of the endothelial cells as regards the proapoptotic gene product Bax in pre-term infants is indicative of an enhanced apoptotic process in these cells. [source] Selected gene polymorphisms and their interaction with maternal smoking, as risk factors for gastroschisis,,BIRTH DEFECTS RESEARCH, Issue 10 2006Claudine P. Torfs Abstract BACKGROUND: Gastroschisis is a severe birth defect in which the infant is born with a portion of the intestines extruding through a small tear in the abdominal wall, usually to the right of the umbilical cord. Its etiology is unknown, but the prevailing hypothesis is that it results from a vascular accident at the time of involution of the right umbilical vein or of the development of the superior mesenteric artery. METHODS: In a case-control study of 57 cases of gastroschisis and 506 controls, we tested DNA for polymorphisms of 32 genes representing enzymes involved in angiogenesis, blood vessel integrity, inflammation, wound repair, and dermal or epidermal strength. RESULTS: In logistic regression, controlling for maternal ethnicity, and using the homozygote wild-type as referent, the following gene polymorphisms were associated with an increased risk for a gastroschisis for heterozygotes: ICAM1 gly241arg (odds ratio [OR], 1.9; 95% confidence interval [CI], 1.1 ,3.4); NOS3 glu298asp (OR, 1.9; 95% CI, 1.1,3.4); NPPA 2238T > C (OR, 1.9; 95% CI, 1.0,3.4); and ADD1 gly460trp (OR, 1.5; 95% CI, 0.8,2.8). Additionally, for the NPPA and ADD1 single-nucleotide polymorphisms (SNPs), the homozygote variants had a significantly higher risk than the heterozygotes (OR, 7.5; 95% CI, 1.7,33.5 and OR, 4.9; 95% CI, 1.9,12.9, respectively). Three SNPs showed a strong interaction with maternal smoking. The risk for smokers with 1 or 2 variant alleles compared to nonsmokers with the wild-type allele were: NOS3 (OR, 5.2; 95% CI, 2.4,11.4); ICAM1 (OR, 5.2; 95% CI, 2.1,12.7); and NPPA (OR, 6.4; 95% CI, 2.8,14.6). CONCLUSIONS: These results support the hypothesis of a vascular compromise as part of a multifactorial etiology of gastroschisis involving both genes and environmental factors. Birth Defects Research (Part A) 76:723,730, 2006. © 2006 Wiley-Liss, Inc. [source] Effects of inactivation-resistant agonists on the signalling, desensitization and down-regulation of bradykinin B2 receptorsBRITISH JOURNAL OF PHARMACOLOGY, Issue 5 2009Marie-Thérčse Bawolak Background and purpose:, A peptide bradykinin (BK) B2 receptor agonist partially resistant to degradation, B-9972, down-regulates this receptor subtype. We have used another recently described non-peptide agonist, compound 47a, as a tool to study further the effects of metabolically more stable and thus persistent, agonists of the BK B2 receptor on signalling, desensitization and down-regulation of this receptor. Experimental approach and key results:, Compound 47a was a partial agonist at the B2 receptor in the human umbilical vein, where it shared with B-9972 a very slow relaxation on washout, and in HEK 293 cell lines expressing tagged forms [myc, green fluorescent protein (GFP)] of the rabbit B2 receptor. Compound 47a desensitized the umbilical vein to BK. In the cellular systems, the inactivation-resistant agonists induced [Ca2+]i transients as brief as those of BK but affected other functions with a longer duration than BK [12 h; receptor endocytosis, endosomal ,-arrestin1/2 translocation, protein kinase C-dependent extracellular signal-regulated kinases (ERK)1/2 phosphorylation and c-Fos expression]. The B2 receptor,GFP was degraded in cells exposed to B-9972 or compound 47a for 12 h. The non-peptide B2 receptor antagonist LF 16-0687 prevented all effects of compound 47a, which were also absent in cells lacking recombinant B2 receptors. Conclusion and implications:, Inactivation-resistant agonists revealed a long-lasting assembly of the agonist,B2 receptor,,-arrestin complexes in endosomal structures and induce ,biased signalling' (in terms of activation of ERK and c-Fos) as a function of time. Further, B-9972 and compound 47a, unlike BK, efficiently down-regulated BK B2 receptors. [source] Spontaneous localized intestinal perforation and intestinal dilatation in very-low-birthweight infantsACTA PAEDIATRICA, Issue 11 2006Tsugumichi Koshinaga Abstract Aim: To elucidate how spontaneous localized intestinal perforation (SLIP) is related to intestinal morphological features such as dilatation in very-low-birthweight (VLBW) infants. Methods: The medical records of 13 VLBW infants (<1500 g) undergoing laparotomy between 1983 and 2003 for presumed SLIP were retrospectively reviewed. Clinical findings including maternal, prenatal and perinatal factors were analysed, and the clinical and surgical findings upon laparotomy were compared. Results: Postnatal pathological conditions included patent ductus arteriosus (n= 7), sepsis (n= 2), respiratory distress syndrome (n= 7), intraventricular haemorrhage (n= 2), an indwelling catheter via the umbilical vein (n= 1) and pneumonia (n= 1). Indomethacin was used in seven neonates with patent ductus arteriosus, and dexamethasone preventive therapy was employed in one neonate for bronchopulmonary dysplasia. Operative findings revealed a localized small punched-out perforation in the ileum. Five patients had intestinal dilatation: two with a perforation in the middle of the dilated intestine, and three with a perforation proximal to the region of dilatation. The muscularis propria was absent in the dilated intestine of four patients. Conclusion: This study found no significant relationship between perforation and dilatation of the intestine. Perforation may occur in any portion of the ischaemic intestine when circulatory failure becomes severe, and is not necessarily restricted to the dilated intestine. We believe that SLIP and intestinal dilatation may occur on the same basis in low-birthweight infants; however, the disease process may be aetiologically different. [source] Insulin restores glucose inhibition of adenosine transport by increasing the expression and activity of the equilibrative nucleoside transporter 2 in human umbilical vein endotheliumJOURNAL OF CELLULAR PHYSIOLOGY, Issue 3 2006Gonzalo Muńoz L -Arginine transport and nitric oxide (NO) synthesis (L -arginine/NO pathway) are stimulated by insulin, adenosine or elevated extracellular D -glucose in human umbilical vein endothelial cells (HUVEC). Adenosine uptake via the human equilibrative nucleoside transporters 1 (hENT1) and 2 (hENT2) has been proposed as a mechanism regulating adenosine plasma concentration, and therefore its vascular effects in human umbilical veins. Thus, altered expression and/or activity of hENT1 or hENT2 could lead to abnormal physiological plasma adenosine level. We have characterized insulin effect on adenosine transport in HUVEC cultured in normal (5 mM) or high (25 mM) D -glucose. Insulin (1 nM) increased overall adenosine transport associated with higher hENT2-, but lower hENT1-mediated transport in normal D -glucose. Insulin increased hENT2 protein abundance in normal or high D -glucose, but reduced hENT1 protein abundance in normal D -glucose. Insulin did not alter the reduced hENT1 protein abundance, but blocked the reduced hENT1 and hENT2 mRNA expression induced by high D -glucose. Insulin effect on hENT1 mRNA expression in normal D -glucose was blocked by NG -nitro- L -arginine methyl ester (L-NAME, NO synthase inhibitor) and mimicked by S -nitroso- N -acetyl- L,D -penicillamine (SNAP, NO donor). L-NAME did not block insulin effect on hENT2 expression. In conclusion, insulin stimulation of overall adenosine transport results from increased hENT2 expression and activity via a NO-independent mechanism. These findings could be important in hyperglycemia-associated pathological pregnancies, such as gestational diabetes, where plasma adenosine removal by the endothelium is reduced, a condition that could alter the blood flow from the placenta to the fetus affecting fetus growth and development. J. Cell. Physiol. 209: 826,835, 2006. © 2006 Wiley-Liss, Inc. [source] Effects of statins on adhesion molecule expression in endothelial cellsJOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 11 2003Y. Dimitrova Summary.,Background:,Inhibitors of HMG-CoA reductase are widely used to prevent atherosclerosis progression. The expression of adhesion molecules on activated endothelial cells (EC) is an important step in the initiation and progression of atherosclerosis. Objectives:,We investigated whether adhesion molecule expression on activated EC is influenced by simvastatin, fluvastatin and pravastatin and, if so, by which mechanisms. Methods:,Human EC from umbilical veins or saphenous veins were pretreated overnight with statins with or without mevalonate, and also for simvastatin or fluvastatin with the isoprenoid intermediates, farnesyl pyrophosphate (FPP), or geranylgeranyl pyrophosphate (GGPP). After 4,6 h activation with tumor necrosis factor (TNF)-, or lipopolysaccharide (LPS), surface adhesion molecule expression was evaluated by ELISA and by flow cytometry. The same experiments were performed with selective inhibitors of geranylgeranyltransferase (GGTI-286) and farnesyltransferase (FTI-277). Results:,Pretreatment with simvastatin, fluvastatin or pravastatin potentiated the TNF-, and LPS-induced expression of E-selectin and VCAM-1, and mevalonate reversed the potentiating effect of these statins. GGPP also reversed the potentiating effect of simvastatin or fluvastatin on adhesion molecule expression, while FPP only partially reversed this effect. Furthermore, GGTI-286, but not FTI-277, mimicked the effect of simvastatin by increasing the TNF-,-mediated overexpression of E-selectin. Conclusions:,Statins increase E-selectin- and VCAM-1-induced expression on vascular endothelial cells stimulated with TNF-, or LPS. The inhibition of geranylgeranylated proteins could contribute to this effect. [source] Vascular Development and Differentiation During Human Liver OrganogenesisTHE ANATOMICAL RECORD : ADVANCES IN INTEGRATIVE ANATOMY AND EVOLUTIONARY BIOLOGY, Issue 6 2008Sophie Collardeau-Frachon Abstract The vascular architecture of the human liver is established at the end of a complex embryological history. The hepatic primordium emerges at the 4th week and is in contact with two major venous systems of the fetal circulation: the vitelline veins and the umbilical veins. The fetal architecture of the afferent venous circulation of the liver is acquired between the 4th and the 6th week. At the end of this process, the portal vein is formed from several distinct segments of the vitelline veins; the portal sinus, deriving from the subhepatic intervitelline anastomosis, connects the umbilical vein, which is the predominant vessel of the fetal liver, to the portal system; the ductus venosus connects the portal sinus to the vena cava inferior. At birth, the umbilical vein and the ductus venosus collapse; the portal vein becomes the only afferent vein of the liver. The efferent venous vessels of the liver derive from the vitelline veins and are formed between the 4th and the 6th week. The hepatic artery forms at the 8th week; intrahepatic arterial branches progressively extend from the central to the peripheral areas of the liver between the 10th and the 15th week. Hepatic sinusoids appear very early, as soon as hepatic cords invade the septum transversum at the 4th week. They then progressively acquire their distinctive structural and functional characters, through a multistage process. Vascular development and differentiation during liver organogenesis is, therefore, a unique process; many of the cellular and molecular mechanisms involved remain poorly understood. Anat Rec, 291:614,627, 2008. © 2008 Wiley-Liss, Inc. [source] Structural Differences in the Umbilical Vein Wall after Full-Term and Pre-term DeliveryANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 5 2009M. Bagyánszki Summary With the exception of its most proximal segment, the human umbilical cord lacks innervation. It might be expected, therefore, that a paracrine effect through the direct contact between the smooth muscle cells and the endothelium may be particularly important in the control of the fetoplacental circulation. In this study, electron microscopy and immunohistochemistry were applied to examine umbilical veins immediately after full-term and pre-term delivery. The smooth muscle cells in the upper layer of the tunica media exhibited long, foot-like processes with c-kit immunoreactivity. In the umbilical vein of full-term neonates more than 50% of these cell processes display a normal ultrastructure and they were closely associated with the lamina elastica interna. Whereas in pre-term infants more than 60% of these cell processes exhibit signs of severe shrinkage and detachedness from the lamina elastica interna. At the same time, the high level of immunoreactivity of the endothelial cells as regards the proapoptotic gene product Bax in pre-term infants is indicative of an enhanced apoptotic process in these cells. [source] | ||||||||||||||||||||||