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Biomedical subjects

T Miyano

Publications and source records attributed to T Miyano.

At least 145 records · Page 8Linked to original sources
PubMed1993

Actin and myosin deposition around bile canaliculi: a predictor of clinical outcome in biliary atresia.

The role of pathological changes of the intrahepatic bile canaliculi in determining postportoenterostomy bile drainage in biliary atresia (BA) patients remains unestablished. It is known that canalicular contraction contributes an active force for bile flow in normal ductal systems. This motility is controlled by the bile canalicular membrane-associated filaments (BCMF), particularly actin and myosin. Wedge resected specimens of liver from 13 patients with BA were studied using histopathological markers of BCMF in order to clarify the morphological and functional changes of bile canaliculi. Histopathological data were also compared with clinical outcomes after portoenterostomy. Patients who showed sufficient bile flow after the operation showed an almost normal shape and level of BCMF accumulation around bile canaliculi, whereas there was markedly increased BCMF volume in patients who did not exhibit bile flow after surgery. The clinical staining patterns of BCMF in BA patients appears closely related to clinical outcome. These findings suggest that BCMF plays an important role in determining the rate of postoperative bile flow in BA patients.

Actins↗
PubMed1993

How great is the incidence of truly congenital common bile duct dilatation?

In an attempt to investigate the causes of common bile duct dilatation (CBDD), activity of the pancreatic enzymes in bile aspirated from the dilated duct during laparotomy was measured in 24 children with CBDD. The reasoning behind this is the fact that the existence of activated pancreatic enzymes, namely raised activity of all enzymes accompanied by trypsin activation, can be regarded as an acquired result of an anomalous choledochopancreaticoductal junction (ACP-DJ). All of the pancreatic enzymes measured were activated in 14 cases (58.3%) but no evidence of activation of enzymes, such as trypsin or others except for amylase and lipase, was observed in the remaining 10 cases (41.7%), whether an ACPDJ was present or absent. Eight of the 10 patients with no enzyme activation (33.3% of the total) were less than 2 months old. The findings in these eight infants, which included cystic dilation or hypoplasia of the intrahepatic duct, provide strong suggestive evidence of the congenital nature of these cases. These results suggest that at least one third of CBDD cases are congenital and the remaining cases are either acquired or a combination of congenital and acquired, or both.

Adolescent↗
PubMed1993

Distribution of neuromuscular junctions in the bowel affected by hypoganglionosis.

Using monoclonal antibody 171B5 against synaptic vesicle proteins, neuromuscular junctions and synapses in the muscle layers of the bowel affected by hypoganglionosis were labeled and their distribution analysed. In the hypoganglionic bowel, there were less synapses in the myenteric plexus and few neuromuscular junctions compared to normal bowels. The bowel dysmotility of the patient with hypoganglionosis appears to be due to inadequate innervation between ganglion cells and smooth muscle cells.

Colon↗
PubMed1993

A new technique for early detection of portal vein and arterial thromboses. Indwelling mesenteric venous catheterization and relevance to small bowel transplantation.

The aim of this study was to ascertain whether, in an animal model, continuous monitoring of mesenteric venous pressure (MVP) via an indwelling mesenteric venous catheter could assist in early detection of thrombosis of the portal vein (PVT) and superior mesenteric artery (SMAT). The role of portography via the catheter was also studied in confirming these complications. An animal model of PVT and SMAT was developed in pigs. At laparotomy, a 20-cm jejunal loop was isolated and a heparin-coated catheter was inserted into a mesenteric vein of the isolated jejunum and connected to a pressure transducer. Conditions of PVT were simulated by progressive occlusion of the portal vein (PV) using a silastic tourniquet and those of SMAT by superior mesenteric artery (SMA) clamping. MVPs (mm Hg) were found to significantly increase with all degrees of PV occlusion (P < 0.01, Student's t test) and to significantly decrease after SMA occlusion (P < 0.01). Portography clearly demonstrated all degrees of PV stenosis after PV occlusion and stasis of contrast medium during SMA occlusion. The authors feel that this method enables rapid diagnosis of PVT and SMAT and may be useful in the monitoring of the therapy for these complications after small bowel transplantation.

Animals↗
PubMed1993

Prolongation of rat cardiac allograft survival by a monoclonal antibody: anti-rat intercellular adhesion molecule-1.

A mouse monoclonal antibody 1A29, which binds to the rat intercellular adhesion molecule-1 (ICAM-1), was studied for its effect on cardiac allograft survival. Expression of ICAM-1 was detectable only on vascular endothelium in normal heart, but was induced on myocardium associated with interstitial mononuclear cell infiltration during acute rejection. Treatment with monoclonal antibody 1A29 for 10 days after transplantation in 15 rats significantly prolonged allograft survival (mean(s.d.) 18(2) days; P < 0.001), as compared with 15 isotype-matched control monoclonal antibody (mean(s.d.) 10(1) days) recipients. Five-day treatment with monoclonal antibody 1A29, when started at 5 days after transplantation (the time for which acute rejection is ongoing), also significantly extended the survival (mean(s.d.) 12(1) days; P < 0.01) in seven rats. On histological examination, treatment with monoclonal antibody 1A29 reduced the degree of T-cell infiltration of both CD4+ and CD8+ subsets, and greatly reduced myocardial necrosis, vascular injury and intravenous thrombi. These results indicate that an anti-ICAM-1 monoclonal antibody can be used to prevent or treat acute rejection in the rat cardiac allograft model and suggest that human ICAM-1 is an important target for immunosuppression in clinical organ transplantation.

Animals↗
PubMed1992

New immunosuppression with monoclonal antibody to intracellular adhesion molecule 1 (ICAM-1) in rat organ transplantation.

Inbred, male Lewis rats underwent heterotopic heart allografting from F344 donor rats, or streptozocin (STZ)-induced diabetic Lewis rats underwent pancreas allografting with bladder drainage from F344 or ACI donor rats. A monoclonal antibody (MoAb) to intracellular adhesion molecule 1 (ICAM-1) was given i. p. (1.0 mg/kg) for 10 days, and its immunosuppressive potency was evaluated. The mean survival time (MST) of the heart allografts was significantly prolonged in the MoAb-treated group. Both exocrine and endocrine MST of pancreas allografts were also prolonged by MoAb administration across the minor and major histocompatibility barriers. However, complete graft tolerance was not induced. Our study demonstrated that the MoAb to ICAM-1 alone can delay the allograft rejection in rat organ transplantation.

Animals↗
PubMed1992

Hirschsprung's disease: diagnosis using monoclonal antibody 171B5.

A new reliable immunohistochemical method for diagnosing Hirschsprung's disease (HD) using our unique monoclonal antibody (MAb) 171B5 against synaptic vesicles is described. Fresh frozen sections of rectal tissues were used from 13 patients with HD aged 2 weeks to 13 months; 9 had rectosigmoid HD and 4 had total colonic aganglionosis (TCA). Comparable normal colonic and rectal specimens were also obtained from 13 age-matched controls. All specimens were labeled with MAb 171B5, to demonstrate neuronal innervation patterns of both mucosa and submucosa. In all control specimens, many synapses arranged in variciform plexuses were seen in the lamina propria, a moderate number in the muscularis mucosae, and dense clusters in the submucosal plexus. In all aganglionic specimens, only scanty numbers of synapses which were not organized in variciform plexuses were seen in the lamina propria, none in the muscularis mucosae, and a few in the submucosa. These findings suggest that MAb 171B5 immunohistochemistry on the lamina propria alone can differentiate between normal and aganglionic bowel and appears to be a reliable and useful method for detecting HD on suction rectal biopsy.

Antibodies, Monoclonal↗
PubMed1992

Patchy distribution of rejection changes in small intestinal transplantation.

The aim of this study is to determine the distribution of histological changes of rejection in small intestinal transplantation. Thirty-nine rats were randomized into two groups: group I (n = 15), syngeneic transplants and group II (n = 24), allogeneic transplants. Grafts were excised and examined on days 2, 4, and 8 after transplantation. All grafts of the syngeneic group showed normal mucosa by day 4. However, by this time, all grafts of the allogeneic group demonstrated rejection changes with a patchy distribution in the mucosa. Therefore, with a biopsy from the stoma site there is a risk of missing early rejection.

Animals↗
PubMed1992

Characteristics and management of patients with fetal neuroblastoma.

At 35 weeks 6 days of gestational age, ultrasound evaluation of the fetal abdomen showed a mixed cystic mass in the superior pole of the left kidney. The mass was suspected to be an adrenal hemorrhage or neuroblastoma. The diagnosis was fetal neuroblastoma. Differential diagnosis enabled the fetal neuroblastoma to be distinguished from adrenal hemorrhage. The parameters of diagnosis of fetal neuroblastoma include no specific ultrasonographic pattern, lack of palpability, and no tumor markers. However, certain features do characterize fetal neuroblastoma, such as little metastases, complete resection at operation, and excellent prognosis. In cases of suspected neuroblastoma, a laparotomy performed as soon as possible is generally regarded as the best course of treatment. Nonetheless, biological analyses of the tumor may prove in the future to be necessary for determining whether or not laparotomy is the best treatment.

Adrenal Gland Diseases↗
PubMed1992

Correlation between extrinsic nerve fibers and synapses in the muscle layers of bowels affected by Hirschsprung's disease.

The aim of this study is to clarify any correlation between nerve terminals (synapses) and proliferating extrinsic nerve fibers in the muscle layers of bowels affected by Hirschsprung's disease (HD). Synapses and extrinsic nerve fibers in the muscle layers of bowels of 10 patients with HD and 8 comparable controls were labeled with monoclonal antibody (MAb) 171B5 and acetylcholinesterase (AChE), respectively. In the control a rich and even distribution of synapses, representing neuromuscular junctions, was seen in the muscle layers, together with dense clusters of synapses in the adjacent myenteric plexuses; proliferation of extrinsic nerve fibers was not seen. In the transitional oligoganglionic segment of HD, many synapses were present in the myenteric plexus, but a few synapses in the muscle layers; there was a gradual increase of extrinsic nerve fibers from proximal to distal. In the narrow aganglionic segment very few synapses were seen in the muscle layers; proliferating nerve fibers and bundles were prominent. We conclude that the muscle layers of bowels affected by HD were almost denervated despite presence of intrinsic nervous elements in the oligoganglionic segment and proliferating extrinsic nerve fibers in the aganglionic segment.

Hirschsprung Disease↗
PubMed1992

The future role of hepatic portoenterostomy as treatment of biliary atresia.

According to our recent study, 38 of 93 patients (40.9%) who underwent portoenterostomy at Juntendo University Hospital between 1977 and 1986 survived for more than 5 years. In order to learn the future improvement of the prognosis of biliary atresia patients who undergo portoenterostomy, we investigated the relationship between the prognosis of biliary atresia patients and the age and the histological changes of liver at the time of surgery. Twenty-seven of 30 patients (90%) who survived for more than 5 years with no jaundice and no findings of liver cirrhosis had a mild degree of liver fibrosis (F1 or F2) and a mild degree of degeneration of intrahepatic bile ducts (B1 or B2) at the time of surgery, in spite of the difference of size of intrahepatic bile ducts at the porta hepatis. On the other hand, all 8 patients who showed severe liver fibrosis (F3) and severe degeneration of intrahepatic bile ducts (B3) did not survive for more than 5 years. Accordingly, we can expect promising prognoses in patients who undergo refined portoenterostomy procedures and receive proper postoperative treatment before they have severe histological changes of liver. The portoenterostomy will still play an important role as treatment of biliary atresia in the future.

Bile Ducts, Intrahepatic↗
PubMed1992

Glomerular alterations in children with biliary atresia.

To investigate the association of glomerular involvement with biliary atresia, we carried out the following studies: (1) review of the clinical records of 120 patients, (2) histologic study of the kidneys obtained at autopsy from 28 patients, and (3) measurements of circulating immune complexes. Of 90 patients with adequate follow-up information, 40 (44.4%) had hematuria, proteinuria, or both. All the kidney specimens showed a wide variety of mesangial proliferation, and immunoglobulins were present in 23 of 26 cases. There was a good correlation between the glomerular alterations and the period of reduced hepatic function. When IgA was present in the mesangium, IgA2 and secretory components were detected. Elevated serum IgA and circulating IgA-containing immune complex levels were found in patients with prolonged obstructive jaundice. These findings indicate that glomerular alterations may occur subsequently in patients with biliary atresia, and that IgA of intestinal mucosal origin plays some role in the development of these lesions.

Antigen-Antibody Complex↗
PubMed1991

Magnetic resonance imaging for localizing the nonpalpable undescended testis.

A prospective evaluation of the value of magnetic resonance imaging (MRI) for localizing the nonpalpable undescended testis was performed in 17 boys aged 1 year to 5 years 4 months who had a clinical diagnosis of nonpalpable testes. The results were compared between the MRI, ultrasonographic, clinical, and definitive surgical diagnosis in all patients. Nine nonpalpable undescended testes were identified in the inguinal canal or just proximal to the inguinal ring by MRI, and these were confirmed by surgical findings. Six nonpalpable testes were not observed by MRI, and the absence of these testes was surgically confirmed. Like scrotal testes, all the undescended testes showed a low intensity on sequences with a short repetition time (TR) and echo time (TE), and a high intensity on long TR/TE sequences. Undescended testes were observed better on coronal images than on axial images. MRI promises to become an important diagnostic tool in the detection of nonpalpable undescended testes.

Child, Preschool↗
PubMed1991

[Pharmacokinetic studies of flomoxef in the neonatal field].

Flomoxef (FMOX), a new broad spectrum oxacephem antibiotic, was studied in the neonatal field and the pharmacokinetic results obtained are summarized below. 1. Serum concentrations of FMOX after dosages of 20 mg/kg via 1 hour drip infusion were 21.8 +/- 7.59 micrograms/ml, 15.4 +/- 4.35 micrograms/ml, 4.3 +/- 2.88 micrograms/ml at 1, 2 and 5 hours after administration, respectively, and T 2/1 (beta)'s averaged 2.08 +/- 1.01 hours. 2. Urinary excretion rates were 53.38 +/- 16.94% in the first 7 hours after administration.

Cephalosporins↗