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Biomedical subjects

M Sakurada

Publications and source records attributed to M Sakurada.

At least 55 records · Page 3Linked to original sources
PubMed1991

[A diffuse metastatic leptomeningeal carcinomatosis from gallbladder cancer; case report].

We encountered a 72-year-old woman with diffuse metastatic leptomeningeal carcinomatosis, who first suffered from occipital pain and died about a month after onset. On postmortem examination, gallbladder cancer (adenocarcinoma) was found to be the primary disease. We focused on its frequency and the metastatic route. On the metastatic route, we obtained the following results: tumor cells infiltrated only the cerebrospinal fluid, but not the areas surrounding the gallbladder cancer (spine or spinal cord) or into the brain parenchyma. A comparative study of the state of cerebrospinal fluid between the ventricle and the subarachnoid space disclosed that the cerebrospinal fluid pressure, cell count, and CEA and CA 19-9 levels increased more in the intraventricular cerebrospinal fluid, especially when the CEA level was higher than that in the serum. On histopathological examination, tumor emboli were seen in choroidal vessels in the ventricular wall, and tumor cells existed sparsely around choroidal secretory vessels. These results were thought to support the theory of hematogenous metastasis as Little et al proposed.

Adenocarcinoma↗
PubMed1989

CD4/Leu7 and CD8/Leu7 large granular lymphocytosis: comparative studies between NK cells and T cells.

Lymphocytes, co-expressing CD4/Leu7 and CD8/Leu7 markers respectively, taken from two patients having large granular lymphocytosis taking an indolent clinical course have been comparatively studied for function as NK cells and T cells. Both large granular lymphocytes (LGLs) were acid phosphatase positive and showed a beta-glucuronidase reaction in their cytoplasmic granules. Studies on case 1 indicated that the CD4/Leu7 lymphocytosis with LGL morphology takes a benign clinical course with mild neutropenia as well as those of CD8/Leu7 LG lymphocytosis. Both CD4/Leu7 and CD8/Leu7 LGLs behave similarly in their lack of NK activity, and manifest decreased IL-2 production in vitro and show a low IL-2 receptor expression unrelated to their T cell phenotype, but behave differently in influencing the immunoglobulin production in vitro and the ADCC activity, depending on their T cell phenotype and on the expression of Fc receptor, respectively. Furthermore, the altered Fc receptors which were undetectable by the Leul 1 antibody but were still effective for ADCC activity might be present in case 2 LGLs.

Aged↗
PubMed1988

First-phase insulin response to glucose in nonobese or obese subjects with glucose intolerance: analysis by C-peptide secretion rate.

This study was proposed to clarify the impairment of first-phase insulin response to glucose in subjects with glucose intolerance by analysis of C-peptide secretion rate after glucose or glucagon injection. The rate was calculated from kinetic analysis of peripheral C-peptide behavior. The rate reached the peak two minutes after glucose injection and then rapidly declined (first-phase secretion) in control subjects. In nonobese subjects with impaired glucose tolerance (IGT) or non-insulin-dependent diabetes mellitus (NIDDM), the rate promptly increased in response to glucose and was followed by a second phase increase. The time course of the rate in the subjects was slightly different from that in control subjects. There was a progressively greater deficit in the first-phase increase with increasing severity of glucose intolerance. The time course of the rate in the obese subjects with NIDDM was different from that in control subjects. The first-phase increase was reduced in the obese subjects with NIDDM. The glucose disappearance rate was correlated with the first-phase increase. Since the time course of the rate after glucagon injection in all subjects did correspond well with that in the control subjects, variation of metabolic clearance rate of endogenous C-peptide among the subjects may be negligible for this study. This study provides the precise time course of first- and second-phase insulin response to glucose injection in nonobese and obese subjects with IGT or NIDDM as well as convincing evidence of the progressive reduction of first-phase insulin response with increasing severity of glucose intolerance. First-phase insulin response to glucose might be slightly delayed in some obese subjects with NIDDM.

Adult↗
PubMed1988

Comparison between fluctuating PEEP and conventional PEEP in dogs with lung injury induced by blood aspiration.

It has been documented that in some patients with acute hypoxic respiratory failure the application of positive end-expiratory pressure (PEEP) may produce no improvement or even a deterioration of pulmonary oxygenation due to an increase in ventilation-perfusion mismatching. Fluctuating PEEP (F-PEEP) is a newly developed PEEP in which end-expiratory pressure (EEP) is periodically changed within a certain range. In a dog model with localized lung injury induced by the aspiration of non-heparinized blood (2 ml.kg body weight-1), F-PEEP in which the EEP was periodically changed from 0.5 to 1.5 kPa at frequencies of 10 min, and conventional PEEP with 3 different fixed EEPs, 0.5, 1.0 and 1.5 kPa (C-PEEP0.5, C-PEEP1.0 and C-PEEP1.5) were each applied for 60 min. F-PEEP produced a periodical change in PaO2 and hemodynamic variables including cardiac output, and in comparison with C-PEEP0.5, C-PEEP1.0 and C-PEEP1.5, a significantly greater improvement of A-aDO2 and dynamic compliance with relatively large cardiac output in the low EEP phase. These results suggest that F-PEEP is a useful mode of artificial ventilation for treating some kinds of acute hypoxic respiratory failure due to increased ventilation-perfusion mismatching.

Animals↗
PubMed1988

Fluctuating PEEP (F-PEEP) versus conventional PEEP in dogs with asymmetrical lung injury.

Fluctuating PEEP (F-PEEP) is a newly developed PEEP in which end-expiratory pressure (EEP) is periodically changed within a certain range. In a dog model with unilateral lung injury induced by the introduction of hydrochloric acid, F-PEEP in which the EEP was periodically changed from 0.5 to 1.5 kPa at periods of 6 min, and conventional PEEP (C-PEEP) with an optimized EEP of 1.0 kPa, were each applied for 30 min. F-PEEP produced a significantly greater improvement of PaO2 and intrapulmonary shunt (QS/QT) than C-PEEP, and at the low EEP phase, the greatest improvement accompanied by an increased dynamic compliance and a large cardiac output was obtained. These results suggest that F-PEEP provides a useful mode of artificial ventilation for the treatment of unilateral lung injury.

Animals↗
PubMed1988

Fluctuating PEEP versus conventional PEEP in diffuse and unilateral lung injury induced by oleic acid.

Effects of fluctuating positive end-expiratory pressure (F-PEEP), in which end-expiratory pressure (EEP) was periodically changed from 0.5 to 1.5 kPa with a periodic time of 6 min, and conventional PEEP (C-PEEP) with a fixed EEP of 1.0 kPa, were comparatively studied in diffuse (Group I) and unilaterally dominant lung injury (Group II). Although F-PEEP produced cyclic alterations of PaO2 in both groups, PaO2 changed in proportion to EEP in Group I and in reciprocal proportion to EEP in Group II. There was no significant difference between PaO2 and QS/QT during F-PEEP and those during C-PEEP in Group I, whereas in Group II, F-PEEP produced a significantly greater improvement of pulmonary oxygenation at the low EEP phase than C-PEEP. In both groups, the degree of hemodynamic depression was proportional to EEP. These results suggest that F-PEEP should be indicated for acute hypoxic respiratory failure with uneven distribution of lung injury.

Animals↗
PubMed1988

So-called sclerosing hemangioma of the lung with nuclear inclusion bodies. Immunohistochemical study of a case.

A so-called sclerosing hemangioma of the lung was removed from a 45-year-old woman after a follow-up of 15 years. In addition to the histology of solid, hemorrhagic, papillary and sclerosing patterns, two types of various-sized, irregularly shaped spaces were found to be lined by either small cells with a high N/C ratio (L1 cells) or large, eosinophilic or foamy cells (L2 cells). These spaces (L1 and L2 spaces) were often alternately arranged. Clusters of L1 cells or L2 cells were also observed in solid-pattern areas with or without lumen formation. Eosinophilic nuclear inclusion bodies (NIB) were exclusively found among L2 cells. L2 cells as well as NIB-containing cells showed an immunohistochemical reactivity similar to that of type II pneumocytes (i.e., positive cytokeratin, epithelial membrane antigen (EMA), surfactant apoprotein, alpha-1-antitrypsin and nonspecific cross-reacting antigen). L1 cells were immunohistochemically similar to solidly growing cells (S cells) which showed positive EMA, alpha-1-antitrypsin and vimentin. These results are consistent with the view that NIB are a good marker for type II pneumocytes in so-called sclerosing hemangioma, and that the two characteristic types of spaces were formed in different ways, thus favoring the theory that S cells are an immature form of type II pneumocytes.

Cell Nucleus↗
PubMed1987

Isolation of dermatan sulfate with high heparin cofactor II-mediated thrombin-inhibitory activity from porcine spleen.

We prepared dermatan sulfate specimens from various porcine tissues, and compared their heparin cofactor II-mediated thrombin-inhibitory activities and chemical natures, including disaccharide composition. Electrophoresis of the specimens on cellulose acetate membrane indicated that spleen dermatan sulfate was the most acidic of the dermatan sulfates prepared from the various porcine tissues. Analysis of the disaccharide units of the dermatan sulfate specimens by high-performance liquid chromatography revealed that spleen dermatan sulfate was rich in 4,6-di-O-sulfated N-acetylgalactosamine residues as compared with those of the other tissues. Spleen dermatan sulfate exhibited the highest thrombin-inhibitory activity, which may be related to its high content of the disulfated N-acetylgalactosamine residue.

Animals↗
PubMed1987

Abnormal calcium handling by perifused pancreatic islets from neonatal streptozotocin diabetic model rats.

To elucidate the mechanism of impaired insulin release in case of non-insulin-dependent diabetes (NIDDM), we investigated insulin release and 45Ca++ efflux from perifused islets obtained from neonatal streptozotocin diabetic model rats. The model rats were prepared by the intraperitoneal administration of 65 mg/kg streptozotocin (STZ) to neonatal males. Rats treated with STZ did not differ from controls in body weight from 1 week to 16 weeks. The model rats had significant hyperglycemia both in the fasting state and after intraperitoneal administration of 2 g/kg glucose. Although the diameter of the islets from the model rats was not significantly different from that of controls, immunoreactivity to anti-insulin was slightly diminished, and degranulation was slightly observed in B-cells. Insulin content was reduced to 45.6% of the control. Insulin release from the perifused islets of STZ-treated rats responded little to 16.7 mmol/L glucose, but normally to 20 mmol/L arginine in the presence of 5.5 mmol/L glucose. In experiments to test the 45Ca++ efflux from the perifused islets prelabeled with 45Ca++, a rise of 45Ca++ efflux concomitant with the second phase of insulin release from the islets of the model rats was inhibited although a sharp increase of 45Ca++ efflux concomitant with the first phase of insulin release was maintained. 45Ca++ uptake for 30 minutes was reduced in the islets from the model rats in the basal and stimulated state of insulin secretion although the incremental 45Ca++ uptake was similar. It is possible that the abnormal calcium handling in pancreatic B-cells may be one of the causes of defect in insulin release in our model rats.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1987

Mechanisms involved in the depleting effect of cysteamine on pancreatic somatostatin.

We investigated the effects of cysteamine on the pancreatic islet hormones and found that pancreatic somatostatin contents depleted 60 min after the oral administration of cysteamine (300 mg/kg) to rats, yet the insulin and glucagon contents remained unchanged. When pancreatic islets isolated by collagenase digestion were incubated for 60 min in Krebs-Ringer bicarbonate buffer containing 0.1, 1, or 10 mM cysteamine, cysteamine dose-dependently decreased the somatostatin content, however, only a high concentration (10 mM) decreased the insulin level, and cysteamine exerted no effect on the glucagon content. The islet hormones (synthetic somatostatin-14, synthetic somatostatin-28, extracted pork insulin and extracted pork glucagon) were incubated for 60 min with cysteamine (0.1, 1, or 10 mM) and somatostatin-14 was found to be markedly decreased by 1 mM cysteamine. Pork insulin but not pork glucagon was dose-dependently decreased by 0.1-10 mM cysteamine. Cysteamine, 0.1-1 mM, did not interfere with the radio-immunoassay system for somatostatin or insulin, although 10 mM cysteamine did so. This compound exerted no effect on the radioimmunoassay system for glucagon. Our studies support earlier findings that cysteamine administered to experimental animals plays a role of relatively specific depletor of somatostatin. The possibility that the depletion of somatostatin is in part due to the remarkable sensitivity of the intracellular compartments of the D cells to the drug and in part due to the remarkable sensitivity of the molecular structure of somatostatin has to be considered.

Animals↗
PubMed1987

Biphasic insulin response to high glucose and a role of protons and calcium.

In order to determine the role of protons and Ca++ in the biphasic insulin response to glucose, we studied the effect of monensin, a carboxylic ionophore, on the first phase and second phase of glucose-induced insulin release and Ca++ efflux from perifused rat pancreatic islets. The agent, 1-100 nM, dose dependently inhibited the insulin release from the islets incubated for 60 min in Krebs-Ringer bicarbonate buffer containing 16.7 mM glucose. Islet 14CO2 production rates from D-(U-14C)glucose were not affected by 10 or 100 nM monensin. Perifusion of the islets prelabeled with 45Ca++ demonstrated that 100 nM monensin had only a slight inhibitory effect on the first phase insulin response to 16.7 mM glucose and no effect on 45Ca++ efflux. This agent inhibited the second phase insulin release and depressed 45Ca++ efflux. When monensin was added at the start of the second phase release, the release was inhibited. When exposed to the agent before the stimulation by glucose, the first phase insulin release was observed, albeit significantly decreased, and the start of the insulin release and 45Ca++ efflux was delayed. The agent, added 30 min after the change to high glucose, immediately inhibited the insulin release. Thus, the first phase insulin release is mediated mainly through a mechanism which is not related to protons generated from glucose metabolism. Protons may be a crucial coupling factor in the second phase insulin release.

Animals↗