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Biomedical subjects

M Miyata

Publications and source records attributed to M Miyata.

At least 487 records · Page 27Linked to original sources
PubMed1988

The function of two heads of myosin in muscle contraction.

Myosin has two heads which can bind with F-actin and react with ATP. The skeletal muscle myosin forms each 1 mol of the myosin-phosphate-ADP complex (M-P-ADP) and the myosin-ATP complex (M-ATP). The actomyosin ATPase reaction which is coupled with muscle contraction is catalyzed only by the head which forms M-P-ADP. However, the function of M-ATP forming head in muscle contraction has not been elucidated. We studied the binding of S-1 and HMM with F-actin and the dissociation of acto-S-1 or acto-HMM by ATP or AMPPNP using the change in light-scattering and fluorescence of pyrene bound to F-actin. S-1 and HMM bound with actin at 1:1 and 1:2 molar ratio, respectively. Acto-S-1 dissociated by one mole of ATP per mole of S-1 but acto-HMM dissociated by 1 mol ATP per mol of HMM (0.5 mol/mol head). Acto-HMM dissociates by AMPPNP (or ADP) via a ternally complex. Acto-HMM bound two mole of AMPPNP, but acto-HMM dissociated by a function of (AMPPNP) but not (AMPPNP)2. These results suggested that the affinity of HMM with F-actin decreased by the binding of one mole of AMPPNP. The result presented here showed that binding of M-ATP forming head with F-actin is controlled by the ATPase reaction of the M-P-ADP forming head. It is suggested that during muscle contraction two heads react cooperatively with thin filament.

Actins↗
PubMed1988

[Experience of Elcitonin treatment in metastatic bony pain of urological tumors].

Fourteen cases of urogenital tumors (9 prostatic carcinomas, 4 renal cell carcinomas and 1 bladder carcinoma) which had bone metastases were treated with eel-calcitonin, Elcitonin injections for relief of bony pain. Forty mgs. of Elcitonin was injected intramuscularly, 2 to 3 times a week, to out-patients. Forty to 80 mgs. of Elcitonin was injected intramuscularly, daily to hospitalized patients. Relief of the pain was obtained in 71.4% of all patients (71.4% of out-patients and 71.4% of hospitalized patients) and especially in 88.9% of prostatic carcinoma patients. Hypercalcemia was seen in only one patient of renal cell carcinoma. It is considered that Elcitonin treatment is useful for relief of bony pain in the patients with bone metastases, with or without hypercalcemia.

Aged↗
PubMed1988

[Management of endourological technics with upper urinary tract diseases except urolithiasis].

Fifteen patients with stricture of upper urinary tract and 4 patients suspected of having upper tract carcinoma were managed with endourological (percutaneous or transurethral) techniques. The strictures were treated with various dilation catheters and the optical urethrotome. Eleven cases (73.3%) were successfully treated and satisfactory urinary passage was attained. The 4 patients suspected of having upper tract neoplasms were diagnosed accurately with endoscopy, 2 patients had transitional cell carcinoma of renal pelvis and the others had benign ureteral polyps. The endourological technique was a useful method for the treatment of ureteral stenosis and the diagnosis of upper tract neoplasm except for the treatment of urolithiasis. This technique will become useful tool in urology.

Adult↗
PubMed1988

[A case of complete resolution of multiple metastases of advanced renal cell carcinoma following partial jejunotomy in intestinal metastases and interferon therapy].

We report a rare case of advanced renal cell carcinoma which showed complete resolution of multiple metastases following nephrectomy, partial metastatectomy and interferon therapy. A 55-year-old male patient underwent right nephrectomy for the renal cell carcinoma with metastases to the right lung and the left femur. In 45 days from the nephrectomy, metastasis to the right humerus was discovered. Immediately after this, the patient suffered occlusive ileus. Laparotomy revealed multiple intestinal tumors, and a temporary partial jejunotomy was performed for the detectable lesions proved to be metastases later. After this operation the pulmonary lesion revealed regression. Then, the patient was treated with daily intramuscular administration of human lymphoblastic interferon (3 X 10(6) units). In consequence, the pulmonary lesion showed complete resolution in two months and the humeral lesion in five months. The left femur which remained osteolytic was replaced by an artificial bone, and revealed no cancer cells histologically. No evidence of metastatic lesion has been found with following intestinal examinations. More than a year has passed since the detection of disease and complete response has persisted for three months under the interferon therapy.

Bone Neoplasms↗
PubMed1988

Histopathologic studies of congenital dilatation of the bile duct as related to an anomalous junction of the pancreaticobiliary ductal system: clinical and experimental studies.

Clinical and experimental studies of congenital dilatation of the bile duct as related to an anomalous junction of the pancreaticobiliary ductal system were performed. Epithelial hyperplasia accompanied by round cell infiltration and increased thickness of the wall with fibrosis was observed histologically in the resected bile ducts of all 40 patients. Twenty-two of 26 patients (86.4%) who had bouts of abdominal pain showed that epithelial hyperplasia with round cell infiltration is dominant (glandular type), and 11 of 15 cases (73.7%) with persistent jaundice showed that thickness of the wall with fibrosis is dominant (fibrotic type). Amylase activities in bile of glandular-type cases obtained from the common bile duct intraoperatively were significantly greater than those of fibrotic-type cases (p less than 0.01). The common bile ducts of the canine model, in which whole pancreatic juice passed in the bile duct, dilated cylindrically 3.28 +/- 2.48 times in diameter after 24 to 41 days and histologically showed epithelial hyperplasia with round cell infiltration of the glandular type. These findings suggest that an anomalous junction of the pancreaticobiliary ductal system and the reflux of pancreatic juice into the bile duct affect not only clinical manifestations but also pathologic changes, especially of the glandular type, in patients with congenital dilatation of the bile duct.

Adult↗
PubMed1988

Pancreatoduodenectomy for periampullary cancer associated with celiac occlusion: a case report.

A 62-year-old man with atherosclerotic occlusion of the celiac axis underwent pancreatoduodenectomy because of cancer of the common bile duct. Preoperative angiography showed that the arterial blood supply to the celiac viscera was sustained through the gastroduodenal artery via the pancreaticoduodenal arcades from the superior mesenteric artery. Therefore reconstruction of the celiac circulation was attempted before division of the gastroduodenal artery. An autograft of the saphenous vein was placed between the infrarenal aorta and the common hepatic artery. The postoperative course was uneventful. Patency of the graft was demonstrated angiographically on the 50th postoperative day.

Adenocarcinoma↗
PubMed1987

Segmental auto-transplantation of the pancreas.

A total pancreatectomy was performed in a 39-year-old man diabetic with diffuse calcification of the whole pancreas, a pseudocyst and intrapancreatic bile duct obstruction. The body of the excised pancreas was immediately transplanted into the left groin. The postoperative responses of plasma glucagon and insulin were not impaired compared with their preoperative responses. The patient was relieved of unremitting pain and is doing well six months after this operation.

Adult↗
PubMed1987

Splenic arteriovenous fistula formation due to angiodysplasia in a splenic aneurysm of a patient with liver cirrhosis--a report of a case.

A 53 year-old Japanese woman with liver cirrhosis manifested massive hematemesis due to ruptured esophageal varices. Celiac angiography demonstrated an aneurysm of the splenic hilus and arteriovenous fistula around the aneurysm. She underwent splenectomy, proximal gastrectomy, distal esophageal devascularization and pyloroplasty. Histological examination of the aneurysm revealed arterial dysplasia with a focal medial gap. Microscopic tissue clefts at the site of a medial gap were considered to be the source of the angiographic arteriovenous fistula.

Aneurysm↗
PubMed1987

Impaired adrenal vascular response to hemorrhagic hypotension by an adreno-femoral venous shunt.

We studied the influence of an adreno-femoral venous shunt on the regional blood flow in the dog adrenal gland during hemorrhagic hypotension. An adreno-femoral venous shunt was placed transperitoneally in the left adrenal gland while the animal was under pentobarbital anesthesia. The right adrenal gland was left intact. Hemorrhagic hypotension was induced at 50 mm Hg mean arterial blood pressure for 1 hr in six dogs and the other six dogs served as normotensive controls. Nonradioactive microspheres (2 X 10(6), 15 +/- 2 micron) were injected into the ventricle. The adrenal cortical and medullary blood flows were estimated by microscopic counting of the microspheres in the serially sectioned adrenal gland. The total adrenal blood flow (sum of the cortical and medullary blood flows) of two methods was compared; the microsphere method vs timed venous sampling through the shunt. In the intact right adrenal gland, the cortical blood flow was significantly decreased, but the medullary blood flow remained unchanged during hemorrhagic hypotension. Subsequently the total adrenal blood flow was not significantly decreased. In the cannulated left adrenal gland, both the cortical and medullary blood flows were significantly decreased and adrenal vascular autoregulation was inhibited. The total adrenal blood flow calculated by the microsphere method showed a significant correlation with that by timed venous sampling through the shunt. These results indicate that the adrenal medullary vasculature autoregulates during hemorrhagic hypotension and that an adreno-femoral venous shunt abolishes this vascular response.

Adrenal Cortex↗
PubMed1987

Natural killer activity enhancing substance in normal human serum.

We studied the effect of normal human serum on natural killer (NK) activity of normal peripheral lymphocytes. Both fresh serum and heat-inactivated (56 degrees C, 30 min) serum significantly enhanced NK activity, in a dose dependent manner, the limit being reached with a final concentration of 5%. However, antibody dependent cell-mediated cytotoxicity (ADCC) was not affected by heat-inactivated serum, although it did show the effects of fresh serum as complement. The serum absorbed with target cells also enhanced NK activity, so it indicated that the enhancing effect of normal serum was not due to the natural antibody against target cells in the serum. The serum was fractionated by Sephadex G-200 into fractions I, II and III in the order of elution. The enhancing factor existed in fraction III. When fraction III was further separated by Cibacron Blue-Sepharose, which selectively adsorbs albumin from serum, the enhancing activity existed in the albumin-rich subfraction. In addition, commercial human albumins had the NK enhancing activity, whereas native transferrin, platelet-derived growth factor (PDGF) or plasminogen did not. These results therefore suggest that the substance enhancing NK activity in normal serum is serum albumin, which is considered to have no significant effect on immune reaction.

Adjuvants, Immunologic↗
PubMed1987

Coexistence of fast and slow myosin isozymes in human external urethral sphincter. A preliminary report.

Human external urethral sphincter muscle was isolated for biochemical research. Myosin samples were prepared and pyrophosphate gel electrophoresis and two-dimensional electrophoresis were performed. Assignment in pyrophosphate gel of myosin isozymes of human external urethral sphincter was carried out by making comparisons with those from human rectus abdominis muscle. Myosin light chains in human external urethral sphincter were identified using two-dimensional electrophoresis. Human external urethral sphincter, similar to other voluntary muscles, is composed of fast and slow twitch muscle fibers, since fast and slow myosin components were shown in both pyrophosphate gel and two-dimensional electrophoretograms.

Electrophoresis↗
PubMed1987

Cystic cemento-ossifying fibroma of the ethmoidal cells (a case report).

A case report of an aggressive cystic cemento-ossifying fibroma of the ethmoidal cells is presented. Fibro-osseous lesions containing cementum are considered to be of periodontal membrane origin and are most common in the mandible and maxilla. Following the WHO classification, fibro-osseous lesions containing cementum are grouped together under the heading of cementoma and are divided into four subgroups. Cemento-ossifying fibroma is considered to be a variant of cementifying fibroma which is a sub-group of cementoma. The unique site of origin seen in this case is thought to have been the result of an ectopic periodontal membrane or of a primitive mesenchymal cell rest or incomplete migration of the medial part of the nasal anlage and differentiation into the periodontal membrane.

Adolescent↗
PubMed1987

Protracted treatment with diazepam increases the turnover of putative endogenous ligands for the benzodiazepine/beta-carboline recognition site.

DBI (diazepam-binding inhibitor) is a putative neuromodulatory peptide isolated from rat brain that acts on gamma-aminobutyric acid-benzodiazepine-Cl- ionophore receptor complex inducing beta-carboline-like effects. We used a cDNA probe complementary to DBI mRNA and a specific antibody for rat DBI to study in rat brain how the dynamic state of DBI can be affected after protracted (three times a day for 10 days) treatment with diazepam and chlordiazepoxide by oral gavage. Both the content of DBI and DBI mRNA increased in the cerebellum and cerebral cortex but failed to change in the hippocampus and striatum of rats receiving this protracted benzodiazepine treatment. Acute treatment with diazepam did not affect the dynamic state of brain DBI. An antibody was raised against a biologically active octadecaneuropeptide (Gln-Ala-Thr-Val-Gly-Asp-Val-Asn-Thr-Asp-Arg-Pro-Gly-Leu-Leu-Asp-Leu-Lys ) derived from the tryptic digestion of DBI. The combined HPLC/RIA analysis of rat cerebellar extracts carried out with this antibody showed that multiple molecular forms of the octadecaneuropeptide-like reactivity are present and all of them are increased in rats receiving repeated daily injections of diazepam. It is inferred that tolerance to benzodiazepines is associated with an increase in the turnover rate of DBI, which may be responsible for the gamma-aminobutyric acid receptor desensitization that occurs after protracted benzodiazepine administration.

Animals↗