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Biomedical subjects

M Miyata

Publications and source records attributed to M Miyata.

At least 469 records · Page 26Linked to original sources

[Kaposi's sarcoma developing during corticosteroid therapy in idiopathic thrombocytopenic purpura].

A case of Kaposi's sarcoma developing during corticosteroid therapy for idiopathic thrombocytopenic purpura is reported. The patient is a 58-year-old female who was admitted to Sapporo City General Hospital for bleeding tendency in March 1987. She had been treated before admission with prednisolone (over 40 mg/day) for idiopathic thrombocytopenic purpura since October 1986, but her platelet count was below 40,000/microliters. In April 1987, several dark red or blue nodules appeared on the tip of her nose, left forearm, right shoulder, trunk and tongue. These nodules rapidly grew. Biopsy specimens from the nodule of the left forearm showed the histologic changes of Kaposi's sarcoma. She was treated with irradiation. Splenectomy was done in May 1987 and prednisolone was decreased to 5 mg/day. Her platelet count was continually kept 50,000/microliters or more. Her Kaposi's sarcoma completely regressed in January 1988. The relationship of immunosuppressive therapy to Kaposi's sarcoma is discussed.

Female↗

Role of gastric inhibitory polypeptide in altered glucose metabolism after removal of the jejunum in dogs.

To investigate the role of gastric inhibitory polypeptide (GIP) in the abnormal glucose metabolism occurring after resection of the small intestine, we performed a serial observation on secretion of GIP in dogs before and after removal of the jejunum. After removal of the jejunum, glucose intolerance was observed when glucose was administered intraduodenally but not intravenously. Significant decreases were simultaneously observed in the responses of both insulin and GIP 1, 3, and 6 months after the surgery compared with the preoperative controls. The insulin response to intravenous glucose was not altered by removal of the jejunum. The response of GIP to intraduodenal lipid also remained decreased for 6 months after the operation. These results indicate that the GIP deficiency caused by removal of the jejunum may play a role in the poor insulin response to luminal stimuli, which contributes to glucose intolerance.

Animals↗

[Treatment of urinary tract infection with cefixime].

Cefixime (CFIX) was administered orally in the treatment of 59 cases of urinary tract infection (UTI). According to the response criteria defined by the Japanese UTI committee, the rate of clinical efficacy for 26 cases of uncomplicated cystitis was 96.2%. The rate of clinical effectiveness of five patients with complicated UTI and five with uncomplicated pyelonephritis was 80.0%. In the other 23 cases which did not meet the response criteria, the efficacy rate was also high. The results indicated that CFIX was an effective drug for the treatment of UTI.

Anti-Infective Agents, Urinary↗

Segmental autotransplantation of the pancreas after total pancreatectomy for advanced periampullary carcinoma--a case report.

A case is reported here in which segmental autotransplantation of the pancreas was performed after total pancreatectomy for advanced periampullary carcinoma in an attempt to preserve pancreatic endocrine function. The postoperative course was uneventful. The requirement of insulin decreased after the operation and the daily profile examination, done 5 months following surgery, showed a permissive fluctuation of blood sugar levels without insulin injection. Thus, segmental autotransplantation of the pancreas offers a method of preserving pancreatic endocrine function after total pancreatectomy for periampullary carcinoma in selected patients.

Carcinoma↗

Reaction of two heads of gizzard myosin with ATP.

The reaction intermediates formed by the two heads of smooth muscle myosin were studied. The amount of myosin-phosphate-ADP complex, MPADP, formed was measured from the Pi-burst size over a wide range of ATP concentrations. At low concentrations of ATP, the Pi-burst size was 0.5 mol/mol myosin head, and the apparent Kd value was about 0.15 microM. However, at high ATP concentrations, the Pi burst size increased from 0.5 to 0.75 mol/mol myosin head with an observed Kd value of 15 microM. The binding of nucleotides to gizzard myosin during the ATPase reaction was directly measured by a centrifugation method. Myosin bound 0.5 mol of nucleotides (ATP and ADP) with high affinity (Kd congruent to 1 microM) and 0.35 mol of nucleotides with low affinity (Kd = 24 microM) for ATP. These results indicate that gizzard myosin has two kinds of nucleotide binding sites, one of which forms MPADP with high affinity for ATP while the other forms MPADP and MATP with low affinity for ATP. We studied the correlation between the formation of MPADP and the dissociation of actomyosin. The amount of Pi-burst size was not affected by the existence of F-actin, and when 0.5 mol of ATP per mol of myosin head was added to actomyosin (1 mg/ml F-actin, 5 microM myosin at 0 degrees C) most (93%) of the added ATP was hydrolyzed in the Pi-burst phase. All gizzard actomyosin dissociated when 1 mol of ATP per mol myosin head was added to actomyosin.(ABSTRACT TRUNCATED AT 250 WORDS)

Actomyosin↗

Elementary steps of the actin-activated ATPase reaction of cardiac muscle myosin subfragment-1.

The rates of the elementary steps of the actomyosin ATPase reaction were measured using the myosin subfragment-1 of porcine left ventricular muscle. The results could be explained only by the two-route mechanism for actomyosin ATPase (Inoue, Shigekawa, & Tonomura (1973) J. Biochem. 74, 923-934), in which ATP is hydrolyzed via routes with or without accompanying dissociation of actomyosin. The dependence on the F-actin concentration of the rate of the acto-S-1 ATPase reaction in the steady state was measured in 5 mM KCl at 20 degrees C. The maximal rate, Vmax, and the dissociation constant for F-actin of the ATPase, Kd, were 3.0 s-1 and 2.2 mg/ml, respectively. The Kd value was almost the same as that determined from the extent of binding of S-1 with F-actin during the ATPase reaction. The rate of recombination of the S-1-phosphate-ADP complex, S-1ADPP, with F-actin, vr, was lower than that of the ATPase reaction in the steady state. Thus, ATP is mainly hydrolyzed without accompanying dissociation of acto-S-1 into S-1ADPP and F-actin. In the cardiac acto-S-1 ATPase reaction, the rate of the ATPase reaction in the steady state and that of recombination of S-1ADPP with F-actin were about 1/5 those of the skeletal acto-S-1 ATPase reaction.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Pseudo-exponential growth in length of the fission yeast, Schizosaccharomyces pombe.

The growth patterns of individual cells of the fission yeast (Schizosaccharomyces pombe wild-type cells, strain 972 h-; cells exposed to hydroxyurea; and cdc mutants, 11-123, 2-33) were investigated by time-lapse photomicrography. Wild-type cells showed one, two, or three linear-growth segments followed by a constant-length stage. Cells with two segments were most frequent. Hydroxyurea cells that divided as oversized cells (about three times the birth length) had three linear-growth segments in a cycle. Mutant cdc11-123 cells did not divide but had a constant-length stage separating the cycles; both the first and second cycles consisted of two linear-growth segments, and cells were oversized at the second constant-length stage (about 3.5 times the birth length). Elongating cdc2-33 cells that did not divide and were oversized (about five times the birth length) while under observation, showed four linear-growth segments. Cells of all strains showed 30 to 40% increase in growth rate at the rate-change point and maintained approximate exponential (pseudo-exponential) growth. We conclude that the normal growth pattern of individual fission-yeast cells is the pseudo-exponential pattern.

Hydroxyurea↗

Hypochlorhydria and hypergastrinemia and their association with gastrointestinal bleeding in young patients with chronic renal failure.

In 40 young patients with chronic renal failure (CRF) on maintenance hemodialysis and 22 control subjects, (1) basal and test meal-stimulated gastrin concentrations, (2) basal and pentagastrin-stimulated gastric acid outputs, and (3) endoscopic examinations were studied. Age-matched CRF patients with control subjects had higher circulating gastrin levels both in the fasting and the test meal-stimulated state and they also had hypochlorhydria. After a test meal, the peak increment of serum gastrin in the CRF patients was more prolonged and greater than in controls. Endoscopic findings showed that the most predominant lesion in the CRF patients was hemorrhagic gastritis. Nine (64.2%) out of 14 patients were hyposecretors and none were hypersecretors. Patients with hyposecretion had higher gastrin levels as well as the same incidence of abnormal endoscopic findings as patients with normosecretion. It is concluded that hypergastrinemia in young CRF patients might be due to a combined effect of impaired renal clearance capacity and overproduction of gastrin associated with hypochlorhydria and also that the cause of gastritis in the young CRF patients might partly be due to a relative impairment of the mucosal defensive mechanism to acid. Our data suggest that the parietal cell response to gastrin in CRF patient may be impaired.

Adult↗

Hypochlorhydria and hypergastrinemia and their association with gastrointestinal bleeding in undialyzed and hemodialyzed patients.

In 15 undialyzed (UD) patients and 26 hemodialyzed (HD) patients, (1) basal and test meal-stimulated gastrin concentrations, (2) basal and pentagastrin-stimulated gastric acid outputs, and (3) endoscopic examinations were studied. Also studied were the morphological and functional differences of the gastrointestinal tract between UD and HD patients. HD patients had lower gastric acid outputs and higher circulating gastrin levels in the fasting state. After a test meal, the peak increment of serum gastrin in UD and HD patients occurred 30 and 60 min later, respectively, and the response was prolonged in each group. Endoscopic findings showed that the incidence of abnormalities in each group was very similar, that is, the most predominant lesions in each group were hemorrhagic and atrophic gastritis. The data suggested that the response to gastrin of parietal cell and the defensive mechanism of gastrointestinal mucosa in HD patients may be impaired.

Adult↗

IgA nephropathy and Henoch-Schönlein purpura nephritis with anterior uveitis.

Two patients with IgA nephropathy and a patient with Henoch-Schönlein purpura nephritis each associated with anterior uveitis are described. As anterior uveitis accompanying IgA nephropathy improved, renal manifestations were relieved. The patient with Henoch-Schönlein purpura nephritis suffered from not only anterior uveitis but also keratitis. It is suggested that immune mechanisms which induce IgA nephropathy may play a role in the development of anterior uveitis and keratitis.

Adolescent↗