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Central Vein (central + vein)
Selected AbstractsStereological measurement of porto-central gradients in gene expression in mouse liverHEPATOLOGY, Issue 2 2004Jan M. Ruijter The liver is thought to consist of lobules, numerous repeating, randomly oriented units. Within these lobules, genes are expressed in gradients along the porto-central axis, which spans the distance between portal and central veins. We have developed a robust stereological method to map all points in an image to their position on this porto-central axis. This approach is based on the distribution of well-characterized periportal and pericentral enzymes, which are visualized on sections preceding and following the section of interest. Because expression of the model genes phosphoenolpyruvate carboxykinase and ornithine aminotransferase declines gradually with increasing distance from the portal vein and central vein, respectively, these genes can be used to prepare images with topographical information without any assumption about the shape of the hepatic unit, or about the direction or shape of the gradient to be determined. The "relative distance" image is a 2-dimensional image that accurately maps the relative position of hepatocytes on the porto-central axis in 3-dimensional space. It is superimposed on the serial section under investigation to relate local staining density to position on the porto-central axis and obtain the gene expression gradient. The method was used to determine the expression gradient of 2 periportal and 2 pericentral enzymes and their response to fasting. The "total distance" image was used to measure the length of the porto-central axis, which was approximately 210 ,m in mice and found to decrease 13% after 1 day of starvation. The method can be applied to any tissue component that can be stained quantitatively. (HEPATOLOGY 2004;39:343,352.) [source] The lobular expression of the rat asialoglycoprotein receptor is regulated at the posttranscriptional levelLIVER INTERNATIONAL, Issue 1 2005Mara Massimi Abstract: The purpose of this study was to define the distribution of the asialoglycoprotein receptor (ASGP-R) main peptide, rat hepatic lectin (RHL)-1, within the rat liver lobule and to investigate its possible modulation in physiological states characterised by marked changes of receptorial expression. In particular, we chose livers from rats partially hepatectomised or at the end of pregnancy, as models, respectively, of decreased or increased expression of the ASGP-R, and used the in situ hybridisation and immunocytochemistry techniques to analyse in parallel the lobular distributions of RHL-1 mRNA and protein. In normal rat liver, although the RHL-1 mRNA was homogeneously distributed, the RHL-1 peptide was predominantly localised on the surface of pericentral hepatocytes with a gradient of expression towards the periportal zone. This gradient of expression of RHL-1 peptide was reduced in regenerating livers, in which the positive stain was restricted to a few layers of cells around the central vein. In contrast, livers at the end of pregnancy showed an overall increase of the peptide with a concomitant flattening of the gradient across the liver plate. In all the conditions, we never observed important changes in the pattern of expression of the specific mRNA. These findings indicate that the distribution of ASGP-R is heterogeneous across the liver lobule, with a pattern of expression prevalently modulated at the posttranscriptional level. [source] Replantation of amputated finger composite tissues with microvascular anastomosisMICROSURGERY, Issue 5 2008Yimin Chai M.D. Replantation of the partial amputated finger or the composite tissue in finger would achieve better functional and esthetical results than any reconstructive procedure. In this article, we report the results of microsurgical partial finger or composite tissue replantation at different anatomic sites of 24 fingers in 21 patients. Microvascular anastomosis was performed in all cases of replantation. For the digital palmar and lateral composite tissue defects, the proper palmar digital artery and volar or dorsal subcutaneous veins were repaired by end-to-end anastomoses. For the digital dorsal defects, the blood supply was reestablished by arterialization of a dorsal central vein in the replanted part with one of the proper palmar digital arteries. The average follow-up period was 12.3 months. Twenty-two of 24 fingers survived completely with good functional and esthetic results. Two replantations failed because of vascular complications. In conclusion, if the vascular vessels in amputations of partial finger and composite tissue of finger are suitable for anastomosis, a successful replantation of these parts with excellent functional and esthetical recovery can be achieved. © 2008 Wiley-Liss, Inc. Microsurgery, 2008. [source] Monitoring of pacemaker induced changes in cardiac output with inspired to endtidal oxygen difference in paediatric cardiac surgery patientsPEDIATRIC ANESTHESIA, Issue 2 2001Jan Bengtsson MD Methods:,Fourteen children aged 4,15 months were studied after corrective cardiac surgery. Heart rate was increased by 20% with an external pacemaker. Cardiac output (CO) was measured with thermodilution. Oxygen saturation was measured in systemic artery (SaO2), central vein (ScvcO2) and pulmonary artery (SvO2). Inspiratory to endtidal oxygen difference (FI - ETO2) was measured using a paramagnetic technique. SvO2 was measured continuously using a spectrophotometric technique. Results:,CO increased in three patients and decreased in 11 patients during pacing. Regression between ,CO and ,(1/Sa-vO2), ,(FI - ETO2/Sa-vO2), ,(FI - ETO2/Sa-cvcO2) showed r=0.70, r=0.76 and r=0.75, respectively. ,CO exceeded 10% in 17 of 26 interventions. Changes in FI - ETO2 of equal direction as changes in CO occurred in 12 of these 17 interventions. Conclusions:,Estimations of CO changes, based on SvO2, can be enhanced if changes in FI - ETO2 are also measured. ScvcO2 instead of SvO2 gives equivalent results. Sudden changes in FI - ETO2 after pacemaker initiation or termination can predict the direction of CO changes. [source] Antioxidant and hepatoprotective effects of punicalagin and punicalin on acetaminophen-induced liver damage in ratsPHYTOTHERAPY RESEARCH, Issue 3 2001Chun-Ching Lin Abstract Punicalagin and punicalin were isolated from the leaves of Terminalia catappa L., a Combretaceous plant distributed throughout tropical and subtropical beaches, which is used for the treatment of dermatitis and hepatitis. Our previous studies showed that both of these compounds exert antioxidative activity. In this study, the antihepatotoxic activity of punicalagin and punicalin on acetaminophen-induced toxicity in the rat liver was evaluated. After evaluating the changes of several biochemical functions in serum, the levels of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were increased by acetaminophen administration and reduced by punicalagin and punicalin. Histological changes around the hepatic central vein and oxidative damage induced by acetaminophen were also recovered by both compounds. The data show that both punicalagin and punicalin exert antihepatotoxic activity, but treatment with larger doses enhanced liver damage. These results suggest that even if punicalagin and punicalin have antioxidant activity at small doses, treatment with larger doses will possibly induce some cell toxicities. Copyright © 2001 John Wiley & Sons, Ltd. [source] On the Structure of the Adrenal Gland of the Common Seal (Phoca vitulina vitulina)ANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 5 2004H. Bragulla Summary The adrenal gland is a vitally important endocrine gland that occupies a central role in the regulatory mechanisms of the body metabolism. Environmental stress factors lead to permanent strain and overload of the body resulting in structural alterations of the adrenals that in turn are followed by hormonal imbalances. This leads to an increased susceptibility to bacterial and viral diseases. The recurrence of numerous fatalities in the different seal populations of the North Sea (during the years 1988, 1989 and 2002), of the Baikal Lake and Caspian Sea (during the years 2000 and 2001) were the motive for a morphological investigation of the species-specific structure of the adrenal gland of the common seal in order to differentiate environmental stress-induced pathological alterations from the physiological structure of this organ. The study was based on adrenals of 112 common seals (Phoca vitulina vitulina) using light microscopic and transmission and scanning electron microscopic methods. The phocine adrenal gland displays several structural characteristics. Originating from the connective tissue organ capsule, narrow and broad septa intersperse the adrenal cortex. These septa contain blastemata as a reserve for the regeneration of hormone-producing cortical cells. Such blastemata are also occurring in the form of an intermediate zone in between the zona glomerulosa and zona fasciculata in the phocine adrenal cortex. Another species-specific characteristic is an inverse part of the adrenal cortex encircling the central vein of the organ. These structural features have to be considered in assessment and definition of pathological alterations of the adrenals as observed in the form of exhausted blastema cell pools in the adrenocortex of seals perished in the mentioned phocine mass mortalities. [source] Stereological measurement of porto-central gradients in gene expression in mouse liverHEPATOLOGY, Issue 2 2004Jan M. Ruijter The liver is thought to consist of lobules, numerous repeating, randomly oriented units. Within these lobules, genes are expressed in gradients along the porto-central axis, which spans the distance between portal and central veins. We have developed a robust stereological method to map all points in an image to their position on this porto-central axis. This approach is based on the distribution of well-characterized periportal and pericentral enzymes, which are visualized on sections preceding and following the section of interest. Because expression of the model genes phosphoenolpyruvate carboxykinase and ornithine aminotransferase declines gradually with increasing distance from the portal vein and central vein, respectively, these genes can be used to prepare images with topographical information without any assumption about the shape of the hepatic unit, or about the direction or shape of the gradient to be determined. The "relative distance" image is a 2-dimensional image that accurately maps the relative position of hepatocytes on the porto-central axis in 3-dimensional space. It is superimposed on the serial section under investigation to relate local staining density to position on the porto-central axis and obtain the gene expression gradient. The method was used to determine the expression gradient of 2 periportal and 2 pericentral enzymes and their response to fasting. The "total distance" image was used to measure the length of the porto-central axis, which was approximately 210 ,m in mice and found to decrease 13% after 1 day of starvation. The method can be applied to any tissue component that can be stained quantitatively. (HEPATOLOGY 2004;39:343,352.) [source] Neuronal nitric oxide synthase immunoreactivity in the guinea-pig liver: distribution and colocalization with neuropeptide Y and calcitonin gene-related peptideLIVER INTERNATIONAL, Issue 6 2001Francisco J. Esteban Abstract:Aims/Background: The innervation pattern of the guinea-pig liver is similar to that of the human liver. However, many aspects of the distribution of the neuronal isoform of the enzyme nitric oxide synthase (nNOS) in the guinea-pig liver and its colocalization with neuropeptides remain to be elucidated. Methods: The distribution of nNOS was studied in fixed guinea-pig liver by light microscopic immunohistochemistry. Confocal analysis was used to determine its colocalization with neuropeptide Y (NPY) or calcitonin gene-related peptide (CGRP). Results: nNOS-immunoreactive (nNOS-IR) nerves were observed in relation to hilar and interlobar vessels and in Glisson's capsule. A few nNOS-IR ganglia were observed in the extrahepatic bile duct and close to the interlobar portal triads. In addition, nNOS-IR fibers were located in the interlobular portal triads and pervading the parenchyma. Moreover, nNOS-IR nerves were demonstrated for the first time in the larger central veins and in the hepatic vein. nNOS-NPY and nNOS-CGRP colocalizations were detected in the fibromuscular layer of the bile duct and periductal plexus, respectively. Conclusions: These results support the phylogenetic conservation of the nNOS-IR hepatic innervation and its possible contribution to the regulation of hepatic blood flow and certain hepatic functions. [source] Cryptogenic fulminant hepatic failure in infancy: Report of 2 cases with unique vascular obstructive changes in native liversLIVER TRANSPLANTATION, Issue 9 2006Naoki Shimojima Although the causes of fulminant hepatic failure (FHF) remain cryptogenic in many cases, a few reports have reviewed the pathological findings of native livers to evaluate the etiology. We report 2 cases of infantile cryptogenic FHF with unique vascular obstructive changes in the native livers. Clinically, it was notable that these 2 patients developed FHF very early in life, at 2 months and 5 months of age, respectively. One patient died from chronic rejection associated with hepatic veno-occlusive disease 4 months after transplantation. Histologically, hepatocytes in the native livers were completely destroyed in both patients, and vascular findings revealed obstruction of central veins in 1 patient and obstruction of portal veins in the other patient. Although the pathogenesis of vascular obstructions is not yet understood, this study suggests that an obstructive vascular event may be a contributing etiologic factor of FHF in infancy. Liver Transpl 12:1418,1422, 2006. © 2006 AASLD. [source] Effects of some pharmacological agents on the survival of unipedicled venous flaps: an experimental studyMICROSURGERY, Issue 8 2001Ibrahim Askar M.D. Clinical and experimental studies have been conducted to improve the survival of venous flaps. As a result of these studies, although various survival mechanisms were raised, none obtained satisfactory information. Venous stasis, and the resultant venous thrombosis, is a factor that decreases the survival of venous flaps. In this study, we evaluated the effects of two antiinflammatory agents, etodolac and etofenamate, on the survival of unipedicled venous flaps. In this study, 35 male New Zealand white rabbits (3,500,4,000 g) (70 ears) were used. Perichondrocutaneous flaps, 3 × 4.5 cm in size, were designed and raised, keeping the central veins intact in the middle of venous flap. Central arteries and nerves were ligated and transected both proximally and distally, to prepare unipedicled venous flaps. A silicone sheet was placed between the cartilage tissue and flap, to prevent blood flow and revascularization beneath. The subjects were divided into seven groups, consisting of five rabbits (10 ears). In the negative control group (group I), the single vascular pedicle of venous flaps, central veins were ligated and flaps sutured into their own place as the composite graft. In the positive control group (group II), after venous flaps were prepared, normal saline, 0.2 mL, was given subcutaneously. In the first of five experimental groups (group III), unfractionated heparin (100 U/day) was given subcutaneously. In the second experimental group (group IV), etodolac (5 mg/kg/day) was given subcutaneously. In the third experimental group (group V), etophenamate (5 mg/kg/day) was given orally through a feeding tube. In the fourth experimental group (group VI), parnaparin (5 anti-Xa U/kg/day) was given subcutaneously. In the fifth experimental group (group VII), nadroparin (5 anti-Xa U/kg/day) was given subcutaneously, about 7 days postoperatively. At the eighth postoperative day, surviving areas of venous flaps were measured, and the results were evaluated by Kruskal-Wallis ANOVA and Mann-Whitney U-test (P < 0.05). Biopsies were also taken from the flaps for histological evaluation of border of necrotic tissue. Surviving areas of unipedicled venous flaps were larger in experimental groups than those in negative and positive control group (P < 0.05). However, comparison of the experimental groups demonstrated no statistically significant difference (P > 0.05). We concluded that all pharmacological agents used in the experimental groups succeeded in increasing the survival of unipedicled venous flaps. Survival of the unipedicled venous flap was higher in venous flaps than that of composite graft, clearly showing the importance of the venous pedicle. © 2001 Wiley-Liss Inc. MICROSURGERY 21:350--356, 2001 [source] Transfemoral Snaring and Stabilization of Pacemaker and Defibrillator Leads to Maintain Vascular Access During Lead ExtractionPACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 3 2009AVI FISCHER M.D. Background: Lead extraction is an effective method for removing pacemaker and defibrillator leads and to obtain venous access when central veins are occluded. Objective: We report a series of patients who required lead extraction and preservation of vascular access requiring a vascular snare introduced from the femoral vein to provide traction on the lead. This technique allowed advancement of the extraction sheath beyond the level of vascular occlusion, preserving vascular access in all patients. Methods: All patients had peripheral contrast venography performed immediately prior to the procedure to identify the site(s) of venous occlusion. An extraction sheath was employed and with direct manual traction, the lead tip pulled free from the myocardial surface prior to advancement of the sheath beyond the occlusion. A transfemoral snare was used to grasp the distal portion of the lead and traction was used to immobilize the lead. Results: In all patients, transfemoral snaring of the leads was necessary to allow safe advancement of a sheath to open the occluded venous system. There were no complications in any of the patients. Conclusion: Our series demonstrates the simple and safe technique of transfemoral lead snaring to assist lead extraction and maintain vascular access in the setting of venous occlusion, when the distal lead tip pulls free of the myocardium before an extraction sheath is passed beyond the point of venous obstruction. [source] Visualisation of needle position using ultrasonographyANAESTHESIA, Issue 2 2006G. A. Chapman Summary Anaesthetists and intensivists spend a considerable proportion of their working time inserting needles and catheters into patients. In order to access deeper structures like central veins and nerves, they have traditionally relied on surface markings to guide the needle into the correct position. However, patients may present challenges due to anatomical abnormalities and size. Irrespective of the skill of the operator, there is the ever-present risk of needle misplacement with the potential of damage to structures like arteries, nerve bundles and pleura. Repeated attempts, even if ultimately successful, cause patient suffering and probably increase the risk of infection and other long term complications. Portable and affordable, high-resolution ultrasound scanners, has accelerated the interest in the use of ultrasound guidance for interventional procedures. Ultrasound guidance offers several advantages including a greater likelihood of success, fewer complications and less time spent on the procedure. Even if the target structure is identified correctly there is still the challenge to place the needle or other devices in the optimum site. The smaller and deeper the target, the greater the challenge and potential usefulness of ultrasound guidance. As a result of limited training in the use of ultrasound we believe that many clinicians fail to use it to its full potential. A lack of understanding, with regard to imaging the location of the needle tip remains a major obstacle. Needle visualisation and related topics form the basis for this review. [source] | ||||||||||||||||||||||