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Biomedical subjects

M Miyata

Publications and source records attributed to M Miyata.

At least 235 records · Page 13Linked to original sources
PubMed1995

Ca2+ release from mitochondria induces cytosolic enzyme leakage in anoxic liver.

The mechanisms of elevation of cytosolic Ca2+ concentration during anoxia causing cytosolic enzyme leakage were studied in perfused rat liver. Before anoxia the Ca2+ contents in mitochondria of perfused rat liver were varied by addition of noradrenaline and glucagon, lowering Ca2+ concentration in the perfusion medium, and addition of Ca2+ channel blocker, either singly or in combination. The amount of cytosolic enzyme leakage during anoxic perfusion positively correlated with the mitochondrial Ca2+ content just before anoxia and also with Ca2+ release from mitochondria during anoxia. However, the amount of cytosolic enzyme leakage during anoxic perfusion did not correlate with the Ca2+ concentration in the perfusion medium and microsomal Ca2+ content. These data support the hypothesis that in anoxic liver, the cytosolic Ca2+ concentration is elevated to a pathological level mainly by Ca2+ release from mitochondria, causing the cytosolic enzyme leakage.

Animals↗
PubMed1995

Laparoscopic extramucosal myectomy with anterior fundoplication (Dor) for esophageal achalasia using intraoperative manometry.

Laparoscopic extramucosal myectomy with anterior fundoplication according to the Dor technique was performed on a 24-year-old-woman. Intraoperative inflation of a pneumatic balloon made the operative procedures such as extended submucosal dissection quite easy. Intraoperative gastrofiberscopy was useful for confirming that the remaining mucosal layer was not injured after completion of myectomy. Intraoperative manometry confirmed a complete decompression of the high-pressure zone in the lower esophageal sphincter. Complete relief of the symptoms has been recognized for 6 months after operation without any medication. It is considered that these laparoscopic procedures including intraoperative inflation of a pneumatic balloon, gastrofiberscopy, and intraoperative manometry can be used as a standard operation for esophageal achalasia.

Adult↗
PubMed1995

Concomitant coronary bypass grafting and curative surgery for cancer.

The surgical management of patients with concomitant critical coronary artery disease (CAD) and surgically resectable cancer is controversial. We evaluated 19 patients who underwent concomitant coronary artery bypass grafting (CABG) and curative operation for cancer of the stomach in 9 patients, the colon in 4, the lung in 4, and the breast in 2. Each cancer operation was performed under stable hemodynamics without any serious bleeding tendency, immediately after CABG with an average of 2.5 +/- 0.8 grafts. There were no operative deaths and no incidences of perioperative myocardial infarction. Postoperative complications developed in three of the patients with lung cancer: respiratory dysfunction caused by phrenic nerve paralysis in two and mediastinitis in one. During the mean follow-up period of 33 +/- 23 months, 5 patients died of recurrent cancer or non-cardiac disease; however, all 19 patients remained free from any postoperative cardiac events and their quality of life apparently improved. This experience suggests that such simultaneous correction would be safe and beneficial in carefully selected patients who have surgically correctable CAD and potentially curable cancer.

Adult↗
PubMed1995

Minute malignant islet cell tumor of the pancreas: report of a case.

We present herein the case of a 73-year-old Japanese man in whom a minute malignant islet cell tumor, 7 mm in maximal diameter, was discovered. The patient was admitted to our hospital to undergo a gastrectomy for gastric cancer, at which time preoperative ultrasonography (US) revealed a minute hypoechoic mass located in the head of the pancreas. Endoscopic retrograde pancreatography, angiography, computed tomography, and magnetic resonance imaging failed to reveal the features or location of the tumor; however, these details were obtained by endoscopic and intraoperative US. Although intraoperative fine-needle aspiration cytology of the tumor enabled a diagnosis of islet cell tumor to be made, it failed to provide enough material to evaluate the grade of malignancy, which was confirmed by histologic examination of the enucleated tumor, allowing the appropriate surgical procedure to be decided.

Aged↗
PubMed1995

Protein kinase C inhibitors affect induction of long-lasting potentiation in the somatosensory cortex.

The effects of protein kinase C (PKC) inhibitors on the induction of long lasting potentiation (LLP) of field potentials in the feline somatosensory cortex were studied. LLP was induced by high frequency stimulation (HFS, 200 Hz) of the ventral posterolateral thalamic nucleus. First, the effects of a protein kinase inhibitor, H-7, and a specific PKC catalytic domain inhibitor, chelerythrine, on the LLP in the secondary somatosensory cortex (SII) were investigated. Intracortical microinjections of H-7 and chelerythrine at 30 min before HFS inhibited induction of LLP in SII, while an injection of chelerythrine at 60 min after LLP induction had no effect on the potentiation. Second, changes in PKC activity in the presence of calcium and phosphatidylserine were investigated in SII after induction of LLP. Triton-soluble membrane fractional PKC activity had increased to 350% of the control value with low frequency test stimulation (0.1 Hz) by five min after HFS. In contrast, PKC activities of cytosolic fractions decreased to 25.6% of the control value. At 60 min after HFS, the PKC activity level returned to the control value, despite persistent potentiation in all cases. PKC activation is considered to be one of the factors required for induction of LLP but not for maintenance in SII.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗
PubMed1995

Splenectomy before tumor inoculation prolongs the survival time of cachectic mice.

The effects of splenectomy on the development of cachexia, tumor growth and animal survival were studied in tumor-bearing CDF1 mice. Mice were inoculated with two subclones of colon 26 adenocarcinoma, clone 20 (with a potent capacity to induce cachexia) and clone 5 (without such activity), and underwent splenectomy before or after tumor inoculation. Splenectomy significantly prolonged the survival of mice bearing clone 20 when it was performed prior to tumor inoculation, although the progression of cachexia and tumor growth were not affected. The survival rate was higher in splenectomized than it was in nonsplenectomized mice 20-40 days after tumor inoculation. Such effects on survival were not observed, however, in mice splenectomized after inoculation with clone 20 or in mice that underwent splenectomy either before or after inoculation with clone 5. The decrease of peripheral blood lymphocyte count observed in mice bearing clone 20 was magnified when splenectomy was performed before tumor inoculation, but the serum levels of tumor necrosis factor and interleukin-6 were comparable. These results indicate that cancer death from cachexia is not directly attributable to enhanced catabolism. The mechanism by which splenectomy ameliorates the survival of cachectic mice remains to be studied, although several changes observed in the splenectomized mice after inoculation, including decreases in the peripheral blood L3T4+ cells and Lyt-2+ cells on the 9th day and 15th day respectively, and increase in the L3T4+/Lyt-2+ cell ratio on the 15th day suggest the involvement of the modified host's immune response.

Adenocarcinoma↗
PubMed1995

Complement-activating properties of IgM rheumatoid factors reacting with IgG subclasses.

To estimate the complement-activating property (CAP) of IgM rheumatoid factor (RF), which was purified from synovial fluids of patients with rheumatoid arthritis, in a reaction with each IgG subclass, the activation and binding of C4 in the classical pathway of complement by IgM RF was measured in an enzyme-linked immunosorbent assay using biotinylated F(ab')2 antibody to human C4. The CAP of IgM RF reacting with IgG3 was significantly higher than that of IgM RFs bound to the other IgG subclasses (P < 0.01). These results suggest that IgM RF reacting with IgG3 in synovial fluid could induce a greater degree of complement-dependent inflammation in RA synovium than IgM RF reacting with other IgG subclasses.

Arthritis, Rheumatoid↗
PubMed1995

Detection of antibodies to 65 KD heat shock protein and to human superoxide dismutase in autoimmune hepatitis-molecular mimicry between 65 KD heat shock protein and superoxide dismutase.

The antibody to 65 KD mycobacterial heat shock protein (HSP65) and antibody to human superoxide dismutase (H-SOD) were measured by ELISA in patients with autoimmune hepatitis (AIH), and results were compared with those of patients with chronic active hepatitis C (CAH-C) or systemic lupus erythematosus (SLE) and normal subjects (NS). Patients with AIH had significantly higher OD values of anti-HSP65 antibody and anti-H-SOD antibody compared with those of patients with CAH-C or SLE and NS. OD values of anti-HSP65 antibody were correlated with those of anti-SOD antibody. Affinity-purified anti-SOD antibody reacted with HSP65. Analysis of the amino acid sequence of human SOD showed that 7 segments, corresponding to r to 25 amino acid residues, exhibited 50 to 71% homology with that of my mycobacterial HSP65.

Amino Acid Sequence↗
PubMed1995

A case of Werner's syndrome associated with systemic lupus erythematosus.

The case of a 40-year-old woman with Werner's syndrome associated with systemic lupus erythematosus (SLE) is reported. The patient exhibited short stature, slender extremities, thinned hair, high-pitched voice, cataracts, ulceration of the fingers, and mental retardation. Malar erythema, photosensitivity, and proteinuria had been noted since age 34. The serum contained high titers of antibodies to dsDNA, Sm, nRNP, and SS-A/Ro. The simultaneous presence of Werner's syndrome and SLE could be a coincidental occurrence of the two diseases, although it might be due to an abnormality in replication or degeneration of DNA leading to the development of both diseases.

Adult↗
PubMed1995

Fulminant second-set allograft rejection and endoscopic findings following small bowel transplantation in the rat.

In the presensitized recipient who has been exposed to donor antigens, second-set rejection takes the form of severe hyperacute graft rejection. Second-set allograft rejection was studied following small bowel transplantation in the rat. Heterotopic intestinal grafting was performed from DA (RT1a) donors to PVG (RT1c) recipients 4 weeks after DA skin sensitization. The endoscopic images and histological specimens were compared with those of syngeneic and first-set rejected grafts. Endoscopically, diffuse erosions of the graft were detected from day 1. Mucosal necrosis progressed rapidly, and was accompanied by massive bleeding on days 3-5. These findings were similar to the course of severe necrotizing hemorrhagic enteritis. Histologically, interstitial edema and hemorrhage with massive infiltrations of neutrophils were manifested from day 1. Mesenteric vessels were completely occluded by thrombi on days 3-5. The grafted intestine had became totally necrotic by day 5. Microscopic findings strongly suggested that destructive graft necrosis was due to vascular damage caused by humoral factors. All the presensitized rats (n = 11) died showing systemic septic signs by day 11 after small bowel transplantation. We conclude that lethal hyperacute rejection occurred in presensitized recipients, even when the graft was transplanted heterotopically. Endoscopic evaluation is beneficial for the early diagnosis of graft rejection. Immediate graft removal should be mandatory as a rescue treatment in second-set rejection of the small intestine.

Animals↗
PubMed1995

Serial changes in plasma levels of pancreatic elastase 1 after pancreatic surgeries.

The alterations of the plasma level of elastase 1 (Ela) were investigated in 15 patients undergoing total pancreatectomy (TP), 18 patients undergoing pancreatoduodenectomy (PD), 8 patients undergoing distal pancreatectomy (DP) and 10 patients undergoing gastrectomy for gastric cancer (GR). The Ela level decreased rapidly below the normal level after TP. The plasma half-life of Ela was 4.6 +/- 1.2 h (Mean +/- SEM). The Ela levels after PD were abnormally elevated until the 7th postoperative day. The Ela levels after DP and GR were elevated gradually until the 7th postoperative day. From 1 to 6 months after PD, DP and GR, the Ela levels were normal. An additional release of Ela from the remaining pancreas following direct surgical interventions to the pancreas resulted in the elevated of the plasma level of Ela in the early postoperative period. The plasma level of Ela was normalized within 2 weeks after pancreatic surgery.

Adult↗
PubMed1995

Induction of long-lasting potentiation in the secondary somatosensory cortex by thalamic stimulation requires cortico-cortical pathways from the primary somatosensory cortex.

We have investigated the role of cortico-cortical inputs from the primary somatosensory cortex in the induction of long-lasting potentiation in the secondary somatosensory cortex. Long-lasting potentiation of evoked potentials in the feline secondary somatosensory cortex is induced by high frequency stimulation of the ventral posterolateral thalamic nucleus. The secondary somatosensory cortex receives two projections from the ventral posterolateral thalamic nucleus; a direct pathway from the ventral posterolateral thalamic nucleus and a cortico-cortical pathway via the primary somatosensory cortex. The present study was designed to examine dominance of these pathways in the induction of long-lasting potentiation in the secondary somatosensory cortex. Long-lasting potentiation was evaluated by changes in the amplitude of field potentials and current source densities elicited by ventral posterolateral thalamic nucleus test stimulation (0.1 Hz) following conditioning stimulation. The conditioning stimulation, consisting of 20 trains of 200 Hz bursts, was delivered to the ventral posterolateral thalamic nucleus or the primary somatosensory cortex. Field potentials in the secondary somatosensory cortex were simultaneously recorded at 16 points placed vertically at 150 microns intervals from the cortical surface and current source density was computed using these field potentials. First, we blocked inputs from the primary somatosensory cortex to the secondary somatosensory cortex by intracortical injection of lidocaine into the primary somatosensory cortex. The amplitudes of the field potentials recorded in the secondary somatosensory cortex diminished within 5 min after lidocaine injection. Current source density analysis showed a marked decrease in the sink currents in layers II/III (at depths of 450-600 microns).(ABSTRACT TRUNCATED AT 250 WORDS)

Anesthetics, Local↗
PubMed1995

An essential role of androgen-induced growth factor in glucocorticoid-dependent autocrine loop in Shionogi carcinoma 115 cells.

Androgen-induced growth factor (AIGF) is essential for the androgen-induced autocrine growth of a mouse mammary Shionogi carcinoma cell line (SC-3 cells). Because glucocorticoid and estrogen have been observed to weakly stimulate DNA synthesis in SC-3 cells, the expression of AIGF mRNA after stimulation with various concentrations of androgen, glucocorticoid, or estrogen was examined by Northern blot analysis. Testosterone, dexamethasone, and estradiol-17 beta (E2) induced AIGF mRNA expression, although the maximum AIGF mRNA expression levels induced by dexamethasone or E2 were lower than that by testosterone. Yet, diethylstilbestrol showed no induction, suggesting that the effect of E2 could be mediated through the androgen receptor. The induction levels of AIGF mRNA by each steroid hormone were correlated positively with hormone-induced DNA synthesis. In addition, the DNA synthesis induced by each steroid hormone was almost completely inhibited by AIGF antisense oligonucleotides, indicating that AIGF is an obligatory component in not only the androgen- but also the glucocorticoid-inducible autocrine loop in SC-3 cells.

Androgens↗
PubMed1995

Branchial cyst of the nasopharynx: resection via the endonasal approach.

We present a rare branchial cyst of the nasopharynx in a 57-year-old man. The cyst was located at the higher level between the roof and the left lateral band of the nasopharynx, and was removed by the endonasal approach following a preparatory septoplasty. While several cases of nasopharyngeal cysts have previously been reported, this appears to be the first case of the resection of such a cyst via the endonasal approach, and is a useful, and potentially less injurious, alternative to the transpalatal approach.

Branchioma↗