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Biomedical subjects

S Nishida

Publications and source records attributed to S Nishida.

At least 541 records · Page 30Linked to original sources
PubMedDate not supplied

Renal dysfunction following adult intestinal transplant under tacrolimus-based immunosuppression.

We analyzed data from the records of 24 adult patients who survived more than 2 years after intestinal transplantation performed between 1995 and 2002 under tacrolimus-based immunosuppression. Ages ranged from 19.3 to 59.2 years old (median 32.1 years). Tacrolimus cumulative level was defined as a sum of weekly average tacrolimus level over time. Kidney function was evaluated by the 6-month average serum creatinine level. Estimated creatinine clearance was calculated with the Cockcroft-Gault formula. Student's t test was used for analysis. Primary diseases were mesenteric thrombosis (n = 7), trauma (n = 4), Crohn's (n = 3), Gardner's (n = 5), and others (n = 7). Procedures were isolated intestinal transplant (n = 10), liver and intestine (n = 1), multivisceral transplant (n = 9), or modified multivisceral transplant (n = 4). Cumulative tacrolimus levels ranged between 1161 and 8623 ng*day/mL (median 4132 ng*day/mL) at 0 to 12 months. Pretransplant kidney function as mean creatinine clearance was 114 mL/min per 1.73 m(2) (n = 24). Creatinine clearance decreased to a mean of 49.6 mL/min per 1.73 m(2) (43.5% of pretransplant) at 2 years (P < .0001). The average creatinine clearance at 18 to 24 months in each patient with a cumulative tacrolimus level <4500 ng*day/mL was 63% +/- 25% of preoperative creatinine clearance. In patients with a cumulative tacrolimus level >4500 ng*day/mL, it was 34% +/- 17%. Cumulative tacrolimus level >4500 ng ng*day/mL was significantly associated with a decreased creatinine clearance at 2 years (P = .006). Renal function decreased significantly after intestinal transplantation in adults. Cumulative tacrolimus level in the first year affected renal function at 2 years.

Adult↗
PubMedDate not supplied

[Studies on early changes in myocardial electrolytes and histological reaction in isoproterenol-induced myocardial injury].

To determine morphological changes in the very early stage of damage and recovery of myocardial fibers in relation to electrolytes and water content in the myocardium, experimental myocardial infarcts were produced after injection of 75 mg/kg isoproterenol (Isp) to rats weighing 270 +/- 10 g. Electrolytes were examined by an atomic absorption spectrophotometer, and histologic examination was performed by light and electron microscopy. At 30 min after Isp injection, Ca and water contents of myocardium increased, but Mg decreased. These myocardial damages showed a maximum level from 6 to 12 h after injection of Isp. It consisted of reversible injury of muscle fibers represented by eosinophilic and fatty degeneration, intermingled with coagulation necrosis of fibers which was irreversible. Most of these eosinophilic degeneration fibers recovered to normal fibers between 12 h and 3 d after the injection. The chronological changes of Ca, Mg, and water contents were well correlated to the morphological early changes of myocardial fibers, and this experimental model by using Isp may be useful for examining the recovery of damaged myocardial tissue and estimating the effects of therapeutics.

Animals↗
PubMedDate not supplied

Exposure of human sperm to low-calcium medium enhances fertilizing ability.

This investigation was conducted to evaluate whether exposure of human sperm to low calcium enhances the fertilizing ability. When sperm from normal semen samples were preincubated in low-calcium mBWW medium for 1 h, the percentages of live acrosome-reacted sperm after 4 and 6 h of culture were significantly higher than control (5.0 +/- 0.5 vs. 3.2 +/- 0.3% and 6.0 +/- 0.5 vs. 4.2 +/- 0.3%, p < .05). The penetration rate (%P) and fertility index (FI) in zona-free hamster egg sperm penetration assay significantly increased, compared to control (%P: 66.4 +/- 9.0 vs. 42.7 +/- 8.1%; FI: 1.69 +/- 0.19 vs. 1.34 +/- 0.11; p < .01). When low-calcium treatment was used for human in vitro fertilization and embryo transfer (IVF-ET) for male infertility, the fertilization and pregnancy rates were significantly higher than those in control. The results indicate that preincubation of human sperm in low-calcium medium enhances their fertilizing ability. This method is a simple and useful for preparing sperm from subfertile men for human IVF-ET.

Acrosome↗
PubMedDate not supplied

A new experimental model for simultaneous evaluation of aortic and pulmonary allograft performance in a composite graft.

A model was developed in pigs for simultaneous evaluation of aortic and pulmonary allograft performance in a composite graft. The composite graft consisted of vascular prosthesis and aortic and pulmonary allografts. Following antibiotic preservation, it was anastomosed to the recipient's thoracic descending aorta by an extrapleural approach without using cardiopulmonary bypass. Aortic blood flow was completely diverted into the composite graft. All 12 recipient pigs recovered well, 4 of which were assigned for the initial study to design the suitable experimental schedule. Calcification readily occurred in the aortic allografts and aneurysmal dilatation without calcification developed in the pulmonary allografts. These morphological findings were consistent with those of previous reports. This model has several benefits. First, aortic and pulmonary allograft conduits can be implanted and evaluated simultaneously under the same conditions by making a composite graft. Second, the magnitude of the operation is minimum, and postoperative circulatory and respiratory management is uncomplicated. Third, wound infection rarely occurs, because the skin incision is made on the back. These preliminary studies suggest that this model will allow future study concerning aortic and pulmonary allograft conduits under different conditions.

Aneurysm↗
PubMedDate not supplied

Primary melanocytoma arising from the thoracic leptomeninges case.

Primary melanocytoma arising from the leptomeninges of the spinal cord is very rare. A surgical specimen of a thoracic meningeal tumor was resected from a 75-year-old woman complaining of gait disturbance was investigated. Magnetic resonance imaging and myelography showed a dumb-bell-type tumor in the subdural space at the 1st to 2nd thoracic vertebrae. The tumor was subtotally resected because of adhesion to the lamina and thoracic medulla. The localized, gelatinous black tumor showed a well-defined margin without dissemination or infiltration. The tumor had a thin capsule and was composed of solid proliferation of neoplastic melanocytes. Neither whorl formation nor foci of palisaded nuclei were observed. The neoplastic cells were of two major types: an epithelioid- or polygonal-shaped type and a spindle-shaped type, and had a large nucleus, a prominent nucleolus, coarse chromatin, and melanin-pigments in their cytoplasm. Only a few mitotic figures were observed. They were positive for HMB-45 and S-100 protein. This case was considered to be primary melanocytoma arising from the thoracic leptomeninges.

Aged↗
PubMedDate not supplied

Molecular detection of disseminated cancer cells in the peripheral blood of patients with gastric cancer.

This study was designed to determine whether circulating cancer cells in patients with gastric cancer can be identified by a RT-PCR method and to assess the clinical significance of the hematogenic dissemination of cancer cell in gastric cancer patients. A total of 41 patients with gastric cancer were enrolled in this study. Peripheral blood samples from 41 patients with gastric cancer were analyzed for CEA mRNA using RT-PCR. Of the 36 patients undergoing radical gastrectomy, eight had a positive CEA mRNA signal in their peripheral blood before the gastrectomy. In four patients, the CEA mRNA signal was negative, positive and then negative again, before, during and after the surgery, respectively. Of the five inoperable patients with peritoneal metastasis, four had positive CEA mRNA signals despite no metastasis in any other organs. The RT-PCR method is a useful diagnostic modality to determine patient selection for chemotherapy after surgery.

Adenocarcinoma↗
PubMedDate not supplied

Combined resection of the involved organs in T4 gastric cancer.

BACKGROUND/AIMS: It remains controversial whether extended surgeries for gastric cancer can improve the postoperative survival rate. This study was designed to evaluate the effectiveness of a combined resection of the involved organs for improving the survival of gastric cancer patients. METHODOLOGY: Of the 1600 patients treated at our Department, from 1969-1993, 231 patients were found to have evidence of adjacent organ spread at laparotomy. Of the 231 patients, 174 underwent a combined resection of the adjacent organs with a gastrectomy due to direct invasion of these organs by the gastric cancer. The clinicopathological characteristics of 231 patients who had adjacent organ spread were compared retrospectively with 495 patients who had no adjacent organ spread. RESULTS: Although the postoperative survival rate of those patients who underwent a gastrectomy with a combined resection of the involved organs was poor, 14 patients survived for 5 years or longer after the surgery. The clinicopathologic factors characteristic of these 14 surviving patients were a lesser extent of lymph node metastasis and high operative curability. CONCLUSIONS: A combined resection of the involved organs with a gastrectomy should be performed when lymph node metastasis is not evident.

Adult↗
PubMedDate not supplied

Bacterial infections after intestine and multivisceral transplantation. The experience of the University of Miami (1994-2001).

BACKGROUND/AIMS: Bacterial infections (BI) are frequent after intestinal transplantation (ITx). Bacteremia, intraabdominal and respiratory infections are the leading forms. The objective of this study is to analyze the occurrence, determinants and outcome of BI. METHODOLOGY: One hundred and twenty-four patients with ITx (39 isolated, 33 liver-intestine, 63 multivisceral). Only major BI were considered, including bacteremia, pneumonia, intraabdominal infections, severe wound infections. RESULTS: BI occurred in 92.7% of patients during follow-up, with an average of 2.9 episodes per patient. Bacteremia was the commonest picture (1.7 per patient). More than 80% of patients had a BI before the end of the second month. Multivariate analysis showed that the presence of BI was higher during the first 2 months after Itx in patients hospitalized before Tx [p=0.029, odds ratio (OR) 5.4] and during months 3 to 6 in those treated with Zenapax (p=0.003, OR 6.2). Occurrence of BI was increased with mycophenolate mofetil treatment (p=0.045 OR 4.2). Intraabdominal infection was more frequent when reTx was needed (p=0.0178 OR 15.2), admission before Tx (p=0.034 OR 2.7), IS with MMF (p=0.004 OR 6.2) and Zenapax (p=0.026 OR 3.6). BI was the direct cause of death in 17.8% of patients, and it was present in 76.2% of patients that died. An infectious episode during the first month, a clinically manifested abdominal infection and a positive intraabdominal culture were determinants of shorter patient survival. CONCLUSIONS: BI continue to be a frequent and dreadful complication after ITx. Pretransplant patient condition, IS used and postoperative complications are crucial on BI onset and outcome.

Abdominal Abscess↗
PubMedDate not supplied

Dehydroepiandrosterone inhibits B16 mouse melanoma cell growth by induction of differentiation.

BACKGROUND: Low serum concentrations of dehydroepiandrosterone (DHEA) and its sulfate are associated with an increased incidence of various human malignancies. DHEA has chemopreventive and antiproliferative effects in experimental studies. Accordingly, the effects of DHEA on B16 mouse melanoma cells were studied. MATERIALS AND METHODS: The effects of DHEA on cell number and melanin production of the melanoma cells were measured. Specific DHEA receptor was detected by a cytosol binding assay. Protein kinase C (PKC) activity of the melanoma cells was detected by phosphorylation of PKC specific substrate. RESULTS: DHEA dose-dependently inhibited the growth of melanoma cells and enhanced melanin production, which indicated the induction of differentiation. There was a [3H]DHEA specific binding protein in the melanoma cell cytosol. Although DHEA did not promote the translocation of PKC from the cytosolic to the membrane fraction, the total PKC activity was upregulated by treatment with DHEA. CONCLUSIONS: DHEA inhibited the growth of B16 mouse melanoma cells by the induction of differentiation, possibly related to PKC upregulation mediated by DHEA receptor.

Animals↗
PubMedDate not supplied

Lymph node metastasis in gastric cancer in the upper third of the stomach--surgical treatment on the basis of the anatomical distribution of positive node.

BACKGROUND/AIMS: Little is known about the most appropriate surgical procedure for gastric cancer in the upper third of the stomach. The objective of this study was to determine the most appropriate surgical treatment for gastric cancer in the upper third of the stomach. METHODOLOGY: The clinicopathological characteristics of 115 node-positive gastric cancers in the upper third of the stomach were reviewed retrospectively and compared with those of 111 node-negative gastric cancers in the upper third of the stomach. RESULTS: Node-positive gastric cancers showed higher rates of peritoneal metastasis (p < 0.005), larger tumor sizes (p < 0.005), deeper tumor penetration (p < 0.005), higher rates of diffuse type in histology (p < 0.025), and more advanced histological stages (p < 0.005), than node-negative gastric cancers. Patients with node-positive gastric cancer demonstrated a poorer survival rate than those with node-negative gastric cancer (p < 0.005). Lymph node metastasis along the lower stomach was observed in cases of gastric cancer which had invaded beyond the muscularis propria of the stomach but not in those confined within the muscularis propria. No lymph node metastasis in the splenic hilum was found in association with gastric cancer when the depth was limited to the mucosa or the submucosa. CONCLUSION: The appropriate surgical procedures for the treatment of gastric cancer in the upper third of the stomach are as follows: a) proximal gastrectomy without splenectomy for gastric cancer when the depth is limited to the mucosa or the submucosa, b) proximal gastrectomy with splenectomy for gastric cancer when the depth of invasion extends to the muscularis propria, c) total gastrectomy with splenectomy for gastric cancer when the depth of invasion extends beyond the muscularis propria.

Female↗
PubMedDate not supplied

Influence of the flow rate during flushing on porcine multivisceral preservation.

The effect of flushing flow rate during multiple organ procurement (MOP) on viability of the liver, pancreas, and intestine were investigated in porcine multivisceral transplantation. Splanchnic organs were flushed in situ with 50 ml/kg of 4 degrees C UW solution via the aorta using a pump at a flow rate of 10, 30, or 50 ml/kg/min. After storage and transplantation, we assessed the clearance of hyaluronic acid (CHA) for hepatic endothelial cells function, liver enzymes, amylase, and histology. Two-day survival was 17% in the 10 ml/kg/min group and 67% in other groups. The former group had inadequate flushing out of the hepatic and intestinal grafts, resulting in aggravation of CHA and intestinal tissue injury. At the flow rate of 30 ml/kg/min, the viability and integrity of all organs were well maintained. We conclude that the optimal flushing flow rate would differ for each organ, therefore the common flow rate acceptable for any of the individual grafts should be applied in MOP.

Animals↗
PubMedDate not supplied

Small bowel rejection in isolated small bowel transplantation and in multivisceral transplantation: a comparative study in a large animal model.

The proposition that a combined graft including the liver protects other organ allografts from the same donor is well known. However, it is not evident in the clinical results. The present experiments were undertaken to compare acute small bowel rejection in isolated small bowel transplantation with multivisceral transplantation. Using 36 outbred, male Large-White pigs, isolated small bowel transplantation (SBTX: n = 9) and abdominal multivisceral transplantation (MVTX: n = 9) were performed without immunosuppression. The survival rate and blood serum samples were monitored postoperatively. In order to compare acute small bowel rejection, sequential biopsy specimens from Thiry-Vella loops were also monitored daily beginning on me 3rd day after transplantation. The specimens were scored from 0 to 3 according to the severity of the rejection. The survival rate was not significantly different. However, significant differences were noted in the cause of the death and in the pathologic changes of the small bowel. In contrast to SBTX, the small bowel rejection of MVTX was significantly delayed and less severe. The rejection score of MVTX was significantly better than SBTX from 5 postoperative days (POD) to 1 lPOD (P < 0.05). The present study demonstrated mat acute small bowel rejection of MVTX graft including the liver was delayed and less severe than that of SBTX in an outbred large animal model.

Animals↗