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Biomedical subjects

S Matsushima

Publications and source records attributed to S Matsushima.

At least 19 recordsLinked to original sources
PubMed1992

The signal-induced phospholipid degradation cascade and protein kinase C activation.

Acting in synergy with diacylglycerol, unsaturated free fatty acids such as arachidonic, oleic, linoleic, linolenic and docosahexaenoic acids dramatically activate some members of the protein kinase C family at the basal level of Ca2+ concentration. It is plausible that phospholipase C and phospholipase A2, and possibly phospholipase D as well, are involved in the activation of protein kinase C. Presumably, this enzyme activation is integrated into the signal-induced membrane phospholipid degradation cascade, prolonging the activation of protein kinase C. The sustained activity of this enzyme appears to be of importance for long-term cellular responses such as development of neuronal plasticity and gene activation.

Animals↗
PubMed1992

[Combined superior-transseptal approach to the mitral valve].

We report a technique to improve exposure of the mitral valve apparatus. This technique that combines superior left atriotomy and interatrial septotomy can be helpful in patients with a small left atrium and reoperation. It has been used effectively in five patients and potential complication with this procedure has not occurred. The operative technique and indication are discussed in this paper.

Adult↗
PubMed1992

[Intraoperative use of real-time ultrasonography in neurosurgery: with special reference to head injury and intracerebral hemorrhage].

We used B mode ultrasonography during 61 craniotomies performed in the acute stage after head injury, intracerebral hemorrhage, ruptured cerebral aneurysm and so on. We examined intracerebral lesions, new hemorrhages near the operative field, and contralateral hemorrhages appearing simultaneously intraoperatively. The resolution with ultrasonography was similar to that of CT and had few obstructing artifacts. It was easy to use and very useful for diagnosing abnormal intracranial mass lesions during craniotomy, mainly for the acute stage of head injury or intracerebral hemorrhage.

Adolescent↗
PubMed1991

Urinary salt excretion and stomach cancer mortality among four Japanese populations.

A relationship between salt intake and the occurrence of stomach cancer has been suggested by both epidemiologic and experimental data. To test this hypothesis, urinary excretion of salt in 24 hours and dietary intake of salt were measured in four male populations with different levels of stomach cancer mortality. Age-adjusted mortality rate of stomach cancer showed a high correlation (r2 = 0.995) with the average amount of salt excretion in 24-hour urine. This strong correlation, however, was not shown (r2 = 0.265) with dietary salt intake calculated from the standard food-composition table. The results confirmed the important role of salt in the development of stomach cancer in Japan, and raised the problem of evaluating the level of salt intake by using the uniform composition table.

Adult↗
PubMed1991

Nonspecific giant ulcer of the sigmoid colon--a case report.

An unusual case of a 44 year old woman who developed a nonspecific ulcer of the sigmoid colon is reported herein. She presented with lower abdominal pain and fever and colonoscopy revealed a large, sigmoid colon ulcer with normal surrounding mucosa and a well-defined margin. A temporary sigmoidostomy was done to decompress the bowel content and, after the abdominal pain and fever had subsided, the involved segment with an ulcer of 6.1 X 2.5 cm was resected. Her postoperative course was uneventful and she has remained well since.

Adult↗
PubMed1991

Postnatal changes in nerve cells and myelinated fibers in the pineal gland of cotton rats (Sigmodon hispidus). A light microscopic study.

Intrapineal neurons and intracapsular and intrapineal myelinated fibers were studied by light microscopy in male cotton rats (Sigmodon hispidus) at various postnatal ages. Until 300 days of age, neurons are encountered mainly in the distal third of the organ; neuronal nuclei are largest in this region. The remaining regions contain only a few neurons with smaller nuclei. In all regions, nuclear sizes of the neurons increase, and neuronal numbers reduce by half until 100-200 days. Neurons thus consist of different populations of cells, and the aging changes in neuronal nuclei seem to be related to the differentiation of the organ. The disappearance of neurons and the enlargement of the nuclei of remaining neurons proceed simultaneously with age. Intracapsular and intrapineal myelinated fibers appear at 20 days and their density increases with age. As the myelinated fibers are distributed mainly in the distal region and its capsule, these fibers are related topographically to intrapineal neurons. The intracapsular myelinated fibers continue into bilateral bundles of myelinated fibers found under the transverse sinuses, corresponding to the nervi conarii. Since the intracapsular fibers and the fibers traced between the capsule and the parenchyma bifurcate in a proximal direction, the intracapsular fibers are considered to run proximally, some entering the organ.

Aging↗
PubMed1991

[The influence of left atrial cuff rejection on pulmonary hemodynamics after canine lung allotransplantation].

Several factors influence pulmonary hemodynamics after lung transplantation: reimplantation response, lung rejection reaction and imperfect anastomosis technique. In this experiment, five cases presented marked elevation of mean pulmonary artery pressure at the time or right pulmonary artery occlusion test performed two weeks postoperatively. Left atrial cuff rejection reaction arose in one case in which edema and stenosis of the pulmonary vein outflow tract were evidenced. This finding demonstrated that the changes in pulmonary hemodynamics after transplant suggest the possibility of inducement by left atrial cuff rejection reaction.

Animals↗
PubMed1991

[Clinical experience of intramediastinal injection therapy via mediastinoscope for lung cancer].

As local treatments other than surgery, radiation therapy, bronchial artery infusion and intrabronchial injection of anti-cancer drugs have generally been administered to inoperative lung cancer cases. Together with these local therapies, we experienced six cases of intramediastinal injection. Indication of this therapy has been fundamentally limited to the inoperative cases in which patient performance status has deteriorated. Histologically, three cases were squamous cell carcinoma and three cases were adenocarcinoma. Injection therapy was effective in four cases where we noted alleviation of atelectasis and obstructive pneumonia brought on by the tumor, and a tendency of the tumor and swelling lymph nodes to be reduced. No side effects nor complications were evidenced. This therapy is characterized by a wider injection area in which intrabronchial injection is incapable of reaching the upper mediastinum, the bifurcation and the upper side of the hilus. The results suggest that this therapy should be used alone or together with other local therapies and prior to operation.

Adenocarcinoma↗
PubMed1990

Human papillomavirus DNA in squamous cell carcinoma of the upper aerodigestive tract.

Nineteen samples of DNA from squamous cell carcinoma of the upper aerodigestive tract were analyzed by Southern blot hybridization for the presence of human papillomavirus (HPV) DNA. Two samples of DNA contained HPV 16 DNA or its homologous sequence. In one maxillary carcinoma, the sequences homologous to HPV 16 were detected. In one tonsillar carcinoma, HPV 16 sequence was also shown to be present. The patients positive for HPV DNA were female and had neither smoking nor drinking habits. These results indicate that HPV infections may play a role in the development of some types of squamous cell carcinomas of the upper aerodigestive tract.

Adult↗
PubMed1990

Effect of photoperiod on pineal gland volume and pinealocyte size in the Chinese hamster, Cricetulus griseus.

Male adult (200-day-old) Chinese hamsters (Cricetulus griseus) raised from weaning under either LD 16:8 or LD 8:16 were used. The pineal gland of the Chinese hamster consists of superficial (major) and deep (minor) components and a continuous, or interrupted, narrow parenchymal stalk interposed between them. The volume of the superficial pineal including the parenchymal stalk is greater under LD 16:8 than under LD 8:16. Under both photoperiods, pinealocytes in the superficial pineal have larger nuclei and more abundant cytoplasm than those in the deep pineal. Nuclei in the superficial pineal appear pale and usually have irregular profiles, whereas those in the deep pineal appear dark and have round profiles. In the superficial pineal, pinealocyte nuclei are larger, paler, and more irregular; and, in addition, nuclear density is lower under LD 16:8 than under LD 8:16. Similar, but less prominent, photoperiod-induced changes occur in the volume of the deep pineal, the size of pinealocytes, and pinealocyte nuclear morphology in the deep pineal. The results indicate that the development and differentiation of pinealocytes in both pineal portions may be advanced under long photoperiods and delayed under short photoperiods, although pinealocytes in the deep pineal may remain not fully differentiated even in adults. Since testicular weights and body weights are similar under both photoperiods, the photoperiod may exert marked influences on the development of the pineal gland without affecting reproductive activity and growth rates of animals.

Animals↗
PubMed1990

Presence of human papillomavirus type-6-related sequences in inverted nasal papillomas.

Twenty DNA samples obtained from seven cases of inverted papillomas, eight cases of nasal polyps and five cases of chronic sinusitis were investigated by Southern blot hybridization for the possible presence of sequences homologous to human papillomavirus (HPV) types 6, 11, 16 and 18. HPV type-6-related DNA was identified in one of the seven inverted papillomas. The restriction endonuclease cleavage patterns showed that this latter DNA is a new subtype of HPV type 6 DNA. In the other six papillomas and in all cases of nasal polyps and chronic sinusitis, no HPV sequence could be demonstrated, even under low stringent conditions (Tm-40 degrees C). These results indicate that HPV infection might be one of the possible causative factors in the pathogenesis of inverted papillomas but is not essential for the induction of the tumor.

Aged↗
PubMed1990

Ischemic stricture of the jejunum--report of a case.

We report herein a case of an 82 year old Japanese woman admitted to hospital after suddenly experiencing upper abdominal pain and vomiting. An upper gastrointestinal series showed a narrow segment with edematous adjacent loops in the proximal jejunum. On the twentieth day following her admission, a barium-meal radiograph revealed that the narrow segment had progressed to a firm tubular stenosis with effacement of the mucosal pattern. The stenotic segment, resected the following day, was 7 cm long with an internal circumference of only 0.5 cm at its narrowest portion. Histologic examination of the resected specimen showed ulceration and marked edema in the intestinal wall, accompanied by organizing and recanalizing thrombi in the subserosal arteries. These features were strongly suggestive of an ischemic process.

Aged↗
PubMed1990

Immunosuppression by gramicidin S of experimental autoimmune uveoretinitis, pinealitis and autoimmune encephalomyelitis.

Using an in vitro lymphocyte proliferation assay we screened several cyclic peptide antibiotics (bacitracin, oleandomycin, capreomycin, colistin, virginiamycin, and gramicidin S) for their immunosuppressive activity. Gramicidin S (GrS) was found to inhibit [3H]-thymidine incorporation into concanavalin A-stimulated and E coli lipopolysaccharide-stimulated lymphocytes. In vivo studies, experimental autoimmune uveoretinitis (EAU) and pinealitis were induced in female Lewis rats by immunization with bovine S-antigen and experimental autoimmune encephalomyelitis (EAE) were induced by immunization of rats with rat brain homogenates. GrS suppressed the onset of these inflammatory diseases at nontoxic concentrations. Evidence was obtained that GrS inhibits [3H]-thymidine incorporation into lymphocytes by preventing transport of the compound across the membrane. Since GrS binds to various cell membranes, GrS would suppress the proliferation of not only lymphocytes but also of other immune cells by modifying cell membrane properties. The present study indicates that a search for compounds which cause proper cell membrane modification should be a worthwhile strategy for development of immunosuppressive drugs.

Amino Acid Sequence↗
PubMed1990

Immunosuppressive effect of gramicidin S on experimental ocular neuritis and allergic encephalomyelitis.

Investigations were carried out on the immunosuppressive effect of gramicidin S (GrS), a cyclic peptide antibiotic produced by Bacillus brevis, on the onset of experimental ocular neuritis and allergic encephalomyelitis in Lewis rats immunized with rat brain homogenates. The criteria for evaluation of the drug effect were changes in body weight, activity of 2',3'-cyclic nucleotide 3'-phosphohydrolase (CNPase), clinical manifestations such as paralysis of lower extremities and histopathological changes. Clinical symptoms and body weight reduction were effectively prevented by GrS treatment of immunized animals. The activity of the myelin marker enzyme CNPase was markedly decreased in the lumbar spinal cord of encephalitogen-immunized animals on day 16 (ie 16 days after immunization) and the decrease of enzymatic activity was partially prevented by GrS administration. On the other hand, the CNPase activity of the retrobulbar optic nerve of inoculated animals remained essentially the same as that of healthy control animals, although inflammatory changes were prominent in the optic nerve. Histopathological changes observed in the optic nerve and spinal cord of diseased animals were virtually absent in GrS-treated animals. A possible mechanism of the immunosuppressive activity of GrS is discussed.

2',3'-Cyclic Nucleotide 3'-Phosphodiesterase↗