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Biomedical subjects

Y Saitoh

Publications and source records attributed to Y Saitoh.

At least 271 records · Page 15Linked to original sources
PubMed1996

The effect of ouabain (inhibitor of an ATP-dependent Na+/K+ pump) on the pancreas graft during preservation by the two-layer method.

To clarify how synthesized ATP is utilized to maintain cellular integrity during preservation by the two-layer method, we examined the effect of ouabain, inhibitor of ATP dependent Na+/K+ pump, on ATP tissue levels, graft weight, and vascular endothelial cells during 48 hr preservation by the two-layer method and pancreatic tissue perfusion and graft survival after transplantation in a canine model. Ouabain treatment did not affect ATP production but prevented its utilization by the sodium pump, and actually significantly increased ATP levels and decreased the weight loss of the graft. In addition, ouabain caused a significant increase of nuclear trypan-blue staining in vascular endothelial cells and a significant decrease of pancreatic tissue perfusion at reperfusion. Consequently, the grafts did not survive. We conclude that the two-layer method allows sufficient synthesis of ATP to drive the sodium pump and maintains membrane integrity of parenchymal cells and vascular endothelial cells, thus extending the period of preserved pancreatic viability.

Adenosine Triphosphate↗
PubMed1996

Direct evidence of pancreatic tissue oxygenation during preservation by the two-layer method.

The purpose of this study was to measure directly tissue oxygen tension (PO2) of the ischemically damaged pancreas graft during preservation by the two-layer (University of Wisconsin solution/perfluoro-chemical) method at 20 degrees C using Clark-type polarographic oxygen electrodes and to make clear the relationship of tissue PO2 and ATP levels during preservation and graft survival after transplantation in a canine model. During warm ischemia, tissue PO2 and ATP were dramatically decreased. Tissue PO2 continued to decrease, and tissue ATP levels were not elevated during simple storage in oxygenated University of Wisconsin solution at 20 degrees C. On the contrary, during preservation by the two-layer method at 20 degrees C, tissue PO2 promptly increased and reached about 50% of the preprocurement level at 30 min of preservation. Then, tissue PO2 was maintained this level throughout the preservation period. Tissue ATP levels were still low in the first 1 hr, but after that tissue ATP increased in a time-dependent manner. Consequently, the two-layer method at 20 degrees C could restore the viability of pancreas damaged by warm ischemia during 3- and 5-hr preservation. We conclude that the ischemically damaged pancreas grafts were oxygenated, and tissue ATP was increased during preservation by the two-layer (University of Wisconsin solution/pefluorochemical) method at 20 degrees C. Consequently, the graft was resuscitated and survived after transplantation.

Adenosine↗
PubMed1996

The role of a hydroxyl radical scavenger (nicaraven) in recovery of cardiac function following preservation and reperfusion.

We investigated the efficacy in reducing myocardial preservation and reperfusion (P/R) injury of direct hydroxyl radical scavenging by nicaraven as compared with scavenging of both superoxide radicals and hydrogen peroxides by superoxide dismutase (SOD) and catalase (CAT), respectively. Isolated rat hearts were mounted on a Langendorff (L) apparatus to estimate the baseline aortic flow (AF), coronary flow (CF), cardiac output (CO), systolic pressure (SP), aortic mean pressure (MP), rate pressure product, and LV dp/dt. They were divided into 3 groups: group 1, 12 hr storage in HTK solution; group 2, 12 hr storage in HTK solution containing 2.5x10(5) U/L SOD and 2x10(5) U/L mg/L CAT; and Group 3, 12 hr storage in HTK solution containing 10(-3) M nicaraven. SOD, CAT, and nicaraven were administered intraperitoneally before harvesting. Hearts were stored in each preservation solution at 4, and then reperfused. Postpreservative function and concentrations of leaked enzymes were measured. The hearts were switched back to the L-mode and paced at 330 beats/min. CF following perfusion with Krebs-Henseleit bicarbonate buffer (KHB) solution containing 10(-6) M 5-hydroxytryptamine (5-HT) or 10(-5) M nitroglycerin (NTG) then evaluated. The myocardial water content also was measured. The recovery of CF, CO, SP, MP, and LV dp/dt was significantly greater in group 3 than in group 1. The recovery of CF was superior to that in group 2 (P<0.05). There were no significant differences in the recovery of cardiac function between groups 1 and 2. 5-HT caused a decrease in CF in each group, however, CF in group 3 was higher than that in group 1 (P<0.05). NTG caused no significant differences among the groups. There were no significant differences in leaked enzymes and myocardial water content among the three groups. These results suggest that nicaraven protects against myocardial P/R injury through its hydroxyl radical scavenging activity, and that therapy with oxygen-free radical scavengers should be directed toward inactivation of hydroxyl radicals rather than superoxide radicals and/or hydrogen peroxides.

Animals↗
PubMed1996

Extending the margin of safety of preservation period for resuscitation of ischemically damaged pancreas during preservation using the two-layer (University of Wisconsin solution/perfluorochemical) method at 20 degrees C with thromboxane A2 synthesis inhibitor OKY046.

We have shown that 5-hr preservation using the two-layer (University of Wisconsin solution/perfluorochemical) method at 20 degrees C allows ATP synthesis and makes it possible to resuscitate a canine pancreas subjected to 90 min of warm ischemia. However, 8 hr of preservation using this method caused a disturbance of vascular microcirculation and did not resuscitate the grafts. The aim of this study was to examine the effect of thromboxane A2 synthesis inhibitor OKY046 on vascular endothelial cells and ATP tissue levels of canine pancreas during preservation using the two-layer (University of Wisconsin solution/perfluorochemical) method at 20 degrees C, and vascular microcirculation and pancreas viability after transplantation. Graft viability was judged by graft survival following autotransplantation. ATP tissue levels were measured by high-performance liquid chromatography at the end of preservation. Viability of the vascular endothelial cells was judged using nuclear trypan blue uptake of the graft after preservation. Pancreatic tissue perfusion was measured using an H2 clearance technique after reperfusion. Pancreas grafts subjected to 90 min of warm ischemia were not viable (0/5). However, 5-hr preservation made it possible to recover the pancreas (5/5); 8-hr preservation was not successful (0/3). ATP tissue levels after 5-hr and 8-hr preservation were 9.40+/-2.09 and 7.37+/-1.06 micromol/g dry weight, respectively, and OKY046 did not affect ATP synthesis during 8-hr preservation (8.44+/-0.92 micromol/g dry weight). The percentage of nuclear trypan blue uptake of endothelial cells in 8-hr-preserved grafts was 37.6+/-11.6% and was significantly higher than the value in 5-hr-preserved grafts (5.0+/-3.0%; P<0.01). However, OKY046 significantly reduced trypan blue uptake in 8-hr-preserved grafts (8.2+/-3.6%; P<0.01). Pancreatic tissue perfusion in 8-hr-preserved grafts after 2 hr of reperfusion was 28.5+/-7.5 ml/min/100 g, and was significantly lower than the value in 5-hr-preserved grafts (57.1+/-4.4 ml/ min/100 g; P<0.01), but OKY046 dramatically improved pancreatic tissue perfusion (97.1+/-14.6 ml/min/100 g; P<0.01). As a consequence, 8-hr-preserved grafts were resuscitated (4/5). We conclude that OKY046 protects the vascular endothelium during preservation by the two-layer method at 20 degrees C and consequently improves vascular microcirculation on reperfusion. Together with ATP synthesis, which is essential for repairing damaged cells, the canine pancreas graft subjected to 90 min of warm ischemia is resuscitated during 8-hr preservation by the two-layer method at 20 degrees C. This method holds promise for pancreas-kidney transplantation from cardiac arrest donors.

Adenosine↗
PubMed1996

The effects of omega-3 polyunsaturated (correction of polyunsatulated) fatty acids on the recovery of cardiac function following cold preservation and reperfusion in hyperlipidemic rats.

We examined the effects of supplementation with eiosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), major components of omega-3 polyunsaturated (correction of polyunsatulated) fatty acids (PUFAs), on basal cardiac function and recovery of cardiac function of "donor hearts" from adults (30 week) rats following cold preservation and reperfusion (P/R). In groups 1, 2, 3, and 4, respectively, 30-week-old rats were fed a soybean oil diet, a high-cholesterol oil (HC) diet, an HC diet with EPA, or an HC diet with DHA for 5 weeks. After collecting blood to analyze plasma levels of fatty acids among each group, the heart was excised and perfused on a Langendorff apparatus. Following evaluation of each rat's cardiac function, each heart was stored in HTK solution for 8 hr at 4 degrees C. The heart was then reperfused and the coronary perfusate was collected to evaluate enzyme that had leaked. After cardiac functional recovery was estimated, myocardial fatty acids were measured. EPA supplementation significantly increases the plasma and cardiac levels of EPA as well as the ratio of EPA to arachidonic acid (AA). EPA supplementation also led to improved recovery of cardiac function following P/P, compared with that of rats who received soybean oil, high-cholesterol oil, and DHA. DHA supplementation significantly increased the plasma and cardiac levels of DHA as well as the ratio of DHA to AA--however, the cardiac functional recovery was almost identical to that of the rats who received high-cholesterol oil and was higher only than that of the rats who received soybean oil. There were no significant differences in enzyme that had leaked and myocardial water content among each group. These results suggest that alterations in the myocardial phospholipid composition by EPA supplementation may be profoundly responsible for attenuating myocardial I/R injuries. In contrast, DHA supplementation may not exert a cardioprotective effect following cold P/R. DHA supplementation alone may not increase the myocardial level of EPA enough to cause a protective effect against P/R injury. EPA supplementation to hyperlipidemic patients may be clinically warranted for increasing the potential number of donors.

Animals↗
PubMed1996

Cardioprotective effect of nicorandil in histidine-tryptophan-ketoglurate solution during the cold storage of isolated hearts.

We compared the efficacy of using histidine-tryptophan-ketoglurate (HTK) solution with that of University of Wisconsin (UW) solution for heart preservation in an isolated rat heart preparation. Nicorandil (NCR) exerts its action as an ATP-sensitive potassium channel opener at low extracellular potassium concentrations, and HTK solution has a low potassium concentration. Therefore, we also investigated the efficacy of using HTK solution with NCR following 12-hr preservation. Hearts isolated from male Wistar rats were mounted on a Langendorff apparatus to estimate baseline aortic flow (AF), coronary flow (CF), cardiac out-put (CO), heart rate (HR), systolic pressure (SP), aortic mean pressure, and the rate-pressure product (RPP). The hearts were divided into four groups: group 1, 8-hr storage in UW solution; groups 2 and 3, 8- or 12-hr storage in HTK solution, respectively; and group 4, 12-hr storage in HTK solution with NCR. They were arrested and stored at 4 degrees C in each preservation solution. Following storage, they were reperfused and postpreservative function was measured to assess cardiac functional recovery. Concentrations of creatine phosphokinase, troponin-T, and lactate in the coronary perfusate were measured. Frozen tissue samples from groups 3 and 4 were analyzed for adenylate content and cGMP. The myocardial water content was also measured. The recovery of AF, CF, CO, SP, and RPP in group 2 was significantly improved compared with that in group 1 (P<0.05). The recovery of AF, CF, CO and HR in group 4 was significantly better than that in group 3 (P<0.05). Creatine phosphokinase leakage in group 2 and troponin-T leakage in group 4 were significantly reduced (P<0.05 vs. groups 1 and 3, respectively). Total adenine nucleotides and the adenylate energy charge in group 4 were well sustained (P<0.05 vs. group 3). These results suggest that HTK solution is more effective than UW solution for cardiac preservation, and that NCR provides still better protection.

Adenosine↗
PubMed1996

Expression of tissue factor correlates with grade of malignancy in human glioma.

BACKGROUND: Tissue factor (TF), a cell surface receptor of factor VII/VIIa, was initially recognized as an initiator of the extrinsic coagulation pathway. TF has recently been found to be expressed highly in certain types of malignant tumors. In addition, TF belongs to the interferon receptor family and is one of the immediate early genes, suggesting that TF may participate in the regulation of cell growth. However, the correlation between the expression of TF and cell growth is still unclear. METHODS: Expression of TF in 6 glioma cell lines and 44 glioma surgical specimens was studied by Northern blot analysis, Western blot analysis, immunohistochemistry, and in situ hybridization. RESULTS: Northern blot analysis showed that glioma cells expressed minor novel transcripts of 3.3 kb and 1.6 kb, in addition to the transcripts of 2.2 kb and 3.1 kb that were previously reported. Western blot analysis revealed that the level of TF protein did not correlate with that of TF transcripts. Although immunohistochemical analysis of surgical specimens showed that all gliomas were positive for TF, it was interesting that 1 of 10 benign gliomas (10%) was positive for TF (malignancy Grade I-II), 13 of 14 anaplastic astrocytomas (86%) (malignancy grade III) and 19 of 20 glioblastomas (95%) (malignancy grade IV) were moderately or strongly positive for TF. In situ hybridization showed the expression of TF mRNA in glioma cells. CONCLUSIONS: TF is expressed in glioma and the level of expression correlates with the histologic grade of malignancy.

Astrocytoma↗
PubMed1996

Serum carcinoembryonic antigen levels and proliferating cell nuclear antigen labeling index for patients with colorectal carcinoma. Correlation with tumor progression and survival.

BACKGROUND: Clinicopathologic variables, carcinoembryonic antigen (CEA), nuclear DNA ploidy, and proliferating cell nuclear antigen labeling index (PCNA LI) have been studied for their effect on patients with various types of cancer. METHODS: Thirteen clinicopathologic variables, preoperative serum CEA levels, PCNA LI, DNA ploidy patterns, and survival were studied for 57 colorectal carcinoma patients, and the mutual relation between these variables, tumor progression, and survival were analyzed. RESULTS: Seven variable including undifferentiated adenocarcinoma, deep invasion, lymphatic and venous invasion, node metastasis, liver metastasis, and advanced stages were significantly greater for patients with positive CEA ( > 5.0 ng/mL) than for patients with negative CEA ( < 5.0 ng/ML). Three variables including deep invasion, liver metastasis, and advanced stages were significantly greater for patients with high PCNA LI ( > 49.4%) than for patients with low PCNA LI ( < 49.4%). No significant difference was observed in any of the variable for patients with DNA diploid or aneuploid cancer. A close relationship representing a formula, Y (log CEA, ng/mL) = 0.026X (PCNA LI, %) - 0.478, was found between CEA level and PCNA LI: Survival curves for patients with negative CEA and low PCNA LI were significantly greater than those for patients with positive CEA and high PCNA LI: Survival curves were significantly greater for patients with positive CEA and low PCNA LI than for patients with positive CEA and high PCNA LI: However, no significant difference was observed in the survival curves of patients with different DNA ploidy patterns. CONCLUSIONS: Serum CEA and PCNA LI for cancer patients is useful in the evaluation of tumor progression and in prognosis. Analysis of DNA ploidy appears to be unavailable for this evaluation.

Adult↗
PubMed1996

Common T cell receptor clonotype in lacrimal glands and labial salivary glands from patients with Sjögren's syndrome.

Sjogren's syndrome (SS) is an autoimmune disease characterized by lymphocytic infiltration into lacrimal and salivary glands leading to symptomatic dry eyes and mouth. Immunohistological studies have clarified that the majority of infiltrating lymphocytes around the lacrimal glands and labial salivary glands are CD4 positive alphabeta T cells. To analyze the pathogenesis of T cells infiltrating into lacrimal and labial salivary glands, we examined T cell clonotype of these cells in both glands from four SS patients using PCR-single-strand conformation polymorphism (SSCP) and a sequencing method. SSCP analysis showed that some infiltrating T cells in both glands expand clonally, suggesting that the cells proliferate by antigen-driven stimulation. Intriguingly, six to sixteen identical T cell receptor (TCR) Vbeta genes were commonly found in lacrimal glands and labial salivary glands from individual patients. This indicates that some T cells infiltrating into both glands recognize the shared epitopes on autoantigens. Moreover, highly conserved amino acid sequence motifs were found in the TCR CDR3 region bearing the same TCR Vbeta family gene from four SS patients, supporting the notion that the shared epitopes on antigens are limited. In conclusion, these findings suggest that some autoreactive T cells infiltrating into the lips and eyes recognized restricted epitopes of a common autoantigen in patients with SS.

Amino Acid Sequence↗
PubMed1996

Improved tumor detection by anti-CEA chimeric Fab oligomers with disulfide linkages in a pancreatic-carcinoma-xenograft model.

We have investigated the effect of Fab oligomerization on imaging efficacy in a pancreatic-carcinoma xenograft model in mice. Recombinant mouse/human chimeric Fab of the anticarcinoembryonic antigen (CEA) monoclonal antibody A10, which has been shown to react specifically with gastrointestinal cancers, was used in this study. Fab homo-oligomers (dimers and trimers) were prepared by linkage of chimeric Fab with N-succinimidyl-3-(2-pyridyldithio)-propionate. Oligomers with S-S bonds showed 10-fold higher binding activity against human CEA than Fab, while the binding activity of oligomers was similar to that of F(ab')2. In mice bearing pancreatic-carcinoma xenografts, tumor uptake of S-S oligomers was significantly greater than that of monomeric Fab, while there was no difference in tumor uptake between S-S Fab trimers and F(ab')2. S-S oligomers showed more rapid clearance rates and uniform percolation in the tumor nodules than F(ab')2. At 18 hr after injection, clear scintigraphic detection of the pancreatic-carcinoma tumors was obtained with 123I-labeled S-S Fab dimers. At 24hr, improved tumor imaging was shown for 123I-labeled S-S Fab oligomers with slightly visible uptake in normal tissues, similar to that of F(ab')2. S-S oligomers of chimeric A10 Fab may be useful as rapid diagnostic tools of pancreatic carcinomas.

Animals↗
PubMed1996

Regulation of mitochondrial pyruvate dehydrogenase activity by tau protein kinase I/glycogen synthase kinase 3beta in brain.

According to the amyloid hypothesis for the pathogenesis of Alzheimer disease, beta-amyloid peptide (betaA) directly affects neurons, leading to neurodegeneration and tau phosphorylation. In rat hippocampal culture, betaA exposure activates tau protein kinase I/glycogen synthase kinase 3beta (TPKI/GSK-3beta), which phosphorylates tau protein into Alzheimer disease-like forms, resulting in neuronal death. To elucidate the mechanism of betaA-induced neuronal death, we searched for substrates of TPKI/GSK-3beta in a two-hybrid system and identified pyruvate dehydrogenase (PDH), which converts pyruvate to acetyl-CoA in mitochondria. PDH was phosphorylated and inactivated by TPKI/GSK-3beta in vitro and also in betaA-treated hippocampal cultures, resulting in mitochondrial dysfunction, which would contribute to neuronal death. In cholinergic neurons, betaA impaired acetylcholine synthesis without affecting choline acetyltransferase activity, which suggests that PDH is inactivated by betaA-induced TPKI/GSK-3beta. Thus, TPKI/GSK-3beta regulates PDH and participates in energy metabolism and acetylcholine synthesis. These results suggest that TPKI/GSK-3beta plays a key role in the pathogenesis of Alzheimer disease.

Animals↗
PubMed1996

Title aggregation patterns of argyrophilic nucleolar organizer regions induced by 5-fluorouracil in the nuclei of MCF-7 human breast cancer cells.

The effects of tamoxifen and 5-fluorouracil (5-FU) on the patterns of argyrophilic nucleolar organizer regions (AgNORs) in MCF7 human breast cancer cells were studied. Tamoxifen and 5-FU both inhibited the growth of MCF-7 cells by 18% by day 3 of culture, but each had different effects on the AgNORs. Whereas no significant changes were induced by tamoxifen, effects on the AgNORs of MCF-7 cells by 5-FU were dramatic: 5-FU treatment changed the pattern of AgNORs, reducing the number of satellites by aggregation, typically to a single aggregation around nucleoli in a sphenoidal fashion. We named these morphological changes: fluorouracil induced AgNOR aggregations (FAA). Following treatment with 500 ng/ml 5-FU, FAA developed rapidly. AgNORs forming two or three aggregates in 24% (6 h), 24% (12 h), 40% (24 h) and 34% (48 h) of cells, compared to a control rate of 14%. Single large aggregate was rarely found in untreated cultures but after 6, 12, 24 and 48 h treatment with 500 ng/ml 5-FU, AgNORs had formed a single aggregate in 6, 8, 16 and 22% of cells, respectively. FAA were observed at a concentration of 100 ng/ml 5-FU; 48 h treatment resulted in cells in which two or three aggregates were increased by 24% and single aggregate by 16%. These large single aggregates were larger than nucleoli stained by Papanicolau staining.

Antimetabolites, Antineoplastic↗
PubMed1996

Photoaffinity labeling of a P3 purinoceptor-like protein purified from rat brain membranes.

We have found a novel adenosine binding protein in rat brain membranes. Based on the ligand binding specificities, this protein is not classified into any known P1 or P2 purinoceptors but is likely to be classified into the putative P3 purinoceptor which was recently proposed. This P3 purinoceptor-like protein was partially purified from rat brain membranes and characterized further by photoaffinity labeling with 8-azidoadenosine-5'-[gamma-32P]triphosphate. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the labeled preparations revealed that the probe is incorporated specifically into a single band with an approximate molecular size of 54 kDa.

Adenine Nucleotides↗
PubMed1996

Small bowel preservation using a cavitary two-layer (University of Wisconsin solution/perfluorochemical) cold storage method.

Preservation of the small bowel by a cavitary two-layer (University of Wisconsin solution [UW]/perfluorochemical) cold storage method was evaluated in the heterotopic rat segmental small bowel transplant model. Simple cold storage UW was effective only for 24-hr preservation. However, the cavitary two-layer method using UW made it possible to prolong preservation time up to 48 hr. Furthermore, without oxygen bubbling, the cavitary two-layer method was not effective for 48-hr preservation. Histologic studies of grafts preserved by the cavitary two-layer method for 48 hr at 7 days after transplantation showed normal architecture of the intestinal mucosa. This study demonstrates that the oxygenation of the small bowel during preservation by the cavitary two-layer method using UW makes it possible to extend preservation time up to 48 hr in the heterotopic rat segmental small bowel transplant model.

Adenosine↗
PubMed1996

Resuscitation of ischemically damaged pancreas during short-term preservation at 20 degrees C by the two-layer (University of Wisconsin solution/perfluorochemical) method.

We have shown that 24-hr preservation by a two-layer (University of Wisconsin solution [UW]/perfluorochemical [PFC]) cold storage method allows tissue ATP synthesis and makes it possible to resuscitate a canine pancreas subjected to 90 min of warm ischemia. The purpose of this study was to examine whether increasing preservation temperature to 20 degrees C makes it possible to shorten a preservation period for recovery of ischemically damaged pancreas grafts. After 90 min of warm ischemia, canine pancreas grafts were preserved using the two-layer (UW/PFC) method for 1 to 8 hr at 20 degrees C, and then autotransplanted. A K-value of intravenous glucose tolerance test more than 1.0 at 2 weeks after transplantation was considered graft survival. ATP tissue levels were measured by high performance liquid chromatography at the end of preservation. Pancreatic tissue perfusions were measured using an H2 clearance technique after 30 min to 4 hr of reperfusion. Pancreas grafts subjected to 90 min of warm ischemia were not viable (0/5, control group). However, 3- and 5-hr preservations made it possible to recover the ischemically damaged pancreas (3/5 and 5/5, respectively), although 1- and 8-hr preservations were not successful (0/3 and 0/3, respectively). ATP tissue levels in 1-hr-preserved grafts were 2.55 +/- 0.38 mumol/g dry weight and were significantly lower compared with the levels in 5- and 8-hr-preserved grafts, 9.40 +/- 2.09 (P < 0.01) and 7.37 +/- 1.06 (P < 0.01), respectively. On the other hand, pancreatic tissue perfusions in 8-hr-preserved grafts after 2 hr of reperfusion were 28.50 +/- 7.52 ml/100 g/min and were significantly lower than the values in 1- and 5-hr-preserved grafts, 66.0 +/- 11.22 (P < 0.01) and 57.10 +/- 4.40 (P < 0.01), respectively. It was suggested that 1-hr-preservation was not enough to synthesize ATP, which was essential to repair damaged cells, although vascular microcirculation at reperfusion was maintained and 8-hr preservation incurred microcirculatory disturbances, although ATP for repairing damaged cells was synthesized. We conclude that 3- to 5-hr preservation at 20 degrees C by the two-layer (UW/PFC) method accelerates ATP synthesis, which is essential for repairing damaged cells and protects vascular microcirculation. This makes it possible to resuscitate ischemically damaged pancreases faster. This method holds promise for pancreas-kidney transplantation from cardiac arrest donors.

Adenosine↗
PubMed1996

Biliary-enteric anastomosis by means of a single layer of serosubmucosal sutures without T-tube drainage.

BACKGROUND: To lessen anastomotic stricture after biliary-enteric anastomosis, we developed a new biliary-enteric anastomosis that uses a single layer of interrupted serosubmucosal sutures without T-tube drainage. OBJECTIVE: To evaluate the safety and reliability of this new technique in a canine model of choledochoduodenostomy. METHODS: In 10 beagles, the common bile duct (2 to 3 mm in diameter) was ligated close to the duodenum with 3-0 polyglactin. On the fifth day after operation, the serum bilirubin level was elevated (137 to 205 mumol/L [8 to 12 mg/dL]) and the bile duct was dilated. The anastomosis between serosubmucosal layers of the dilated bile duct (8 to 10 mm in diameter) and duodenum was accomplished with interrupted sutures of 6-0 polyglactin with two needles. Stitches were inserted in the submucosal plane at the cut edge of the duct and duodenum to appose the mucosa accurately and to avoid accidental perforation of the entire thickness of the duct and duodenum. A T tube was not placed. RESULTS: There was no anastomotic leakage and the bilirubin level was normalized (14 to 17 mumol/L [0.8 to 1.0 mg/dL]) 7 days after operation for anastomosis. Histologic examination of specimens removed 6 or 12 months after operation showed good connective-tissue union and good mucosal continuity between the bile duct and the duodenum. There was no mucosal scarring and contracture or stricture formation. CONCLUSION: This new technique is simple and reliable and is recommended as an alternative method for restoring the continuity between the bile duct and intestinal tract after operation for obstructive jaundice caused by benign and malignant stricture of the bile duct.

Animals↗
PubMed1996

Effects of adrenal medulla transplantation into the third ventricle on the onset of puberty in female rhesus monkeys.

To test the hypothesis that prepubertal exposure of LHRH neurons to a source of catecholamines and neuropeptides accelerates the onset of puberty, we examined the effects of autologous adrenal transplantation into the base of the third ventricle of the brain in juvenile female rhesus monkeys at 11-13 months of age. The adrenal medulla, which contains catecholamines and neuropeptide Y (NPY), was cut into small pieces and mixed with gelfoam in artificial CSF and injected into the third ventricle, adjacent to LHRH neurons and their neuroterminals. Sham control monkeys received artificial CSF with gelfoam alone. Animals were monitored for signs of pubertal development. While menarche was not altered by adrenal transplantation, the timing of first and second ovulations occurred significantly (P < 0.05) earlier in adrenal-transplanted monkeys. Histological examination indicated that the grafts survived in all transplanted monkeys. The presence of catecholamines and NPY in graft tissue was confirmed by tyrosine-hydroxylase-positive, dopamine beta-hydroxylase-positive, and NPY-positive cells. Endogenous LHRH fibers were observed innervating the graft tissue. We conclude that: (1) adrenal medulla transplantation into the third ventricle accelerates the age of first ovulation; (2) this is likely due to neuroactive substances (e.g., catecholamines and NPY) from the graft tissue; and (3) grafted adrenal medulla tissue can survive for at least 30-40 months. However, the age of menarche was not accelerated by this grafting, suggesting that an additional mechanism (e.g., removal of tonic inhibition) may be necessary for the onset of puberty.

Adrenal Medulla↗