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Biomedical subjects

K Sano

Publications and source records attributed to K Sano.

At least 577 records · Page 32Linked to original sources
PubMed1986

High-affinity receptor-mediated internalization and degradation of interleukin 2 in human T cells.

Receptor-mediated internalization and degradation of IL-2 were investigated in cell lines carrying human T cell leukemia/lymphoma (lymphotrophic) virus type I (HTLV-I) and PHA-treated normal PBL. The HTLV-I-carrying cell lines ILT-Yan and TL-Mor, and the PBL expressed both high- and low-affinity IL-2-R. However, another HTLV-I-carrying T cell line, MT-1, expressed mainly low-affinity receptors. Greater than 50% of the IL-2 bound to high-affinity receptors was internalized within 10 min when these cells were incubated at 37 degrees C. The internalized IL-2 was rapidly degraded and the products were excreted into the culture fluid. The t1/2 of IL-2 degradation in these cells was estimated as 60-80 min at 37 degrees C. The internalization and degradation of IL-2 were both temperature dependent. Light-microscopic autoradiography with 3H-labeled IL-2 confirmed the internalization of IL-2, and suggested that some IL-2 might be carried to the nucleus.

Cell Compartmentation↗
PubMed1986

The future role of neurosurgery in the care of cerebral tumors.

Diagnostic methods to discover a brain tumor and surgical techniques to remove it are steadily advancing. Most well-demarcated tumors can be removed by operation alone. Malignant, invasive tumors, however, will continue to offer a difficult and serious problem except when they are found while still very small in size, by elaborate diagnostic tools and except when they are conveniently located. For those tumors, surgery alone is not enough. Extermination of tumor cells by surgery, radiotherapy, chemotherapy, immunotherapy, etc., or combinations of these has achieved some results but with considerable limitations. We must search for the ways of peaceful coexistence with tumor cells, i.e., living with the tumor cells which are kept non-dividing and non-metastasizing by some means. Recent developments in oncology, such as discovery of c-onc genes, various growth factors, etc., give us some hope in the researches in this direction.

Brain↗
PubMed1986

Changes of uric acid level in rat brain after focal ischemia.

Changes of uric acid level in rat cerebral hemisphere after left middle cerebral artery (MCA) occlusion were studied by reversed-phase HPLC with electrochemical detection. Uric acid level in the normal group was 2.98 nmol/g tissue. Uric acid concentration of the left hemisphere in the left MCA-occluded group progressively increased after occlusion, and reached a maximum value of 67.26 nmol/g tissue 24 h after ischemia. Uric acid levels in the right hemisphere remained unchanged. Uric acid concentration of the left hemisphere in sham-operated group was 9.29 nmol/g tissue 24 h after the operation.

Animals↗
PubMed1986

Predominance of gluconate formation from glucose during germination of Bacillus megaterium QM B1551 spores.

Metabolic pathways of glucose during germination of Bacillus megaterium QM B1551 spores were studied by using specifically labeled glucose and gluconate. The Embden-Meyerhof pathway, the pentose cycle, and the direct oxidation route of glucose to gluconate (the gluconate pathway) were all operative at this stage; among those, gluconate accumulation was most predominant, especially in the early stage. Potassium fluoride, an enolase inhibitor, abolished the catabolism by the Embden-Meyerhof pathway totally without affecting gluconate accumulation. Under these conditions glucose was exclusively oxidized to gluconate. Gluconate thus accumulated could be metabolized further via phosphorylation by gluconate kinase. Remarkable gluconate accumulation was also demonstrated in several other spores requiring alanine as an effective germinant. NADH formed by the direct glucose oxidation may serve as a initial ATP source to phosphorylate glucose in germinating spores.

Bacillus↗
PubMed1986

A modified method of fine-granular cationic iron colloid preparation: its use in light and electron microscopic detection of anionic sites in the rat kidney glomerulus and certain other tissues.

Ferric chloride, when boiled with hydrazine hydrate and cacodylic acid, is converted into a fine cationic iron (ferric hydroxide) colloid which consists of 0.5-1.5 nm electron-dense granules, and gives a distinct Prussian blue reaction. This colloid allows light and electron microscopic detection of ionized anionic sites in tissues at a wide pH range of 0.8-7.6. It is smaller in size and more stable, and assures longer and greater staining of tissues, especially at low pH levels, than the iron colloid prepared with sodium or ammonium cacodylate by Seno and his associates (1983, 1984, 1985). Some light and electron micrographs of the rat kidney, spleen and other organs stained with our colloid are presented as examples. These micrographs confirm that the glomerular podocyte end-foot surface facing the Bowman's capsular space is strongly negative-charged. They also show that almost all lymphoid cells around the arteries in the splenic white pulp and thymic cortex contain strongly negative-charged nuclei and that the distal convoluted and collecting urinary tubules are more negative-charged than the proximal convoluted tubules.

Animals↗
PubMed1986

[Toxicological studies on isepamicin (HAPA-B). I. Acute toxicity test in the mouse, rat and dog].

Acute toxicity of isepamicin (HAPA-B), a new aminoglycoside antibiotic, in mice, rats and dogs was examined in comparison with amikacin (AMK) and gentamicin (GM). Intravenous LD50 values of HAPA-B were 234 mg/kg in male and 236 mg/kg in female for mice, 489 mg/kg in male and 476 mg/kg in female for rats and 720-864 mg/kg for dogs. Those of AMK were 183 mg/kg in male and 181 mg/kg in female for mice, 420 mg/kg in male and 417 mg/kg in female for rats. Those of GM were 50 mg/kg in male and 47 mg/kg in female for mice, 119 mg/kg in male and 124 mg/kg in female for rats. Intraperitoneal LD50 values of HAPA-B were 2,244 mg/kg in male and 2,272 mg/kg in female for mice, 1,664 mg/kg in male and 1,591 mg/kg in female for rats. Intramuscular LD50 values of HAPA-B were 2,508 mg/kg in male and 2,632 mg/kg in female for mice, 2,088 mg/kg in male and 2,111 mg/kg in female for rats and greater than 1,800 mg/kg for dogs. Those of AMK were 1,247 mg/kg in male and 1,334 mg/kg in female for mice, 2,324 mg/kg in male and 2,244 mg/kg in female for rats. Those of GM were 359 mg/kg in male and 360 mg/kg in female for mice, 559 mg/kg in male and 557 mg/kg in female for rats. Subcutaneous LD50 values of HAPA-B were 3,321 mg/kg in male and 3,320 mg/kg in female for mice, 3,451 mg/kg in male and 3,392 mg/kg in female for rats. Oral LD50 values of HAPA-B were more than 5,000 mg/kg in mice and rats. Ataxia, acratia, dyspnea and convulsions were observed following administration by all routes, except for oral route, of all drugs in mice, rats and dogs. The cause of early death was due to respiratory paralysis which is the typical acute toxic sign of aminoglycoside antibiotics, and that of late death was due to renal injuries. BUN and creatinine values of surviving dogs after day 14 increased after administration by either intravenous or intramuscular routes. Disintegration, necrosis and calcification of epithelial cells of the proximal convoluted tubuli were observed in rats which died during the course of the study, and atrophy, dilatation and eosinophilic degeneration in epithelial cells of the proximal convoluted tubuli and thickening of Bowman's capsule were observed in surviving dogs.

Administration, Oral↗
PubMed1986

[Toxicological studies on isepamicin (HAPA-B). II. Intramuscular subacute toxicity test in the rat].

Subacute toxicity in the rat of isepamicin (HAPA-B), a new aminoglycoside antibiotic, was examined in comparison with amikacin (AMK). Daily doses of 12.5, 25, 100 and 300 mg/kg of HAPA-B or 25 and 100 mg/kg of AMK were injected intramuscularly for 28 days. No animal died and there were no changes in general symptoms except for hemorrhage at injection sites of both drugs. Decreases in body weight gain and food consumption were observed in males and females in the HAPA-B 300 mg/kg dose group. Water consumption was increased in males in the HAPA-B 300 mg/kg and AMK 100 mg/kg dose groups. Elevations of serum creatinine and/or BUN in males and females were occasionally observed in the HAPA-B 300 mg/kg and AMK 100 mg/kg dose groups, and elevation of GOT, which seemed to be due to muscle injuries, was occasionally observed in a no dose-dependent manner with either drug. Increases in kidney and caecum weights of males and females in the HAPA-B 100, 300 mg/kg and AMK 25, 100 mg/kg dose groups and increases in adrenal relative-weights in males and females in the HAPA-B 300 mg/kg dose group were observed. At necropsy, discoloration and enlargement of the kidney were observed in a dose-dependent manner at or above 100 mg/kg with either drug. Histopathological findings indicated degeneration and necrosis in epithelial cells of the proximal convolute tubuli and thickening of basement membrane. Electron microscopic findings indicated an increase in number of large lysosomes containing myeloid bodies in the epithelial cells of the proximal convolute tubuli with both drugs. The above results suggest that HAPA-B has renal toxicity like other aminoglycoside antibiotics but its toxicity was lower than AMK. The non-toxic dose of HAPA-B in this test was 12.5 mg/kg.

Amikacin↗
PubMed1986

[Toxicological studies on isepamicin (HAPA-B). IV. Intramuscular subacute toxicity test in the dog].

The subacute toxicity in the dog of isepamicin (HAPA-B), a new aminoglycoside antibiotic, was studied in comparison with amikacin (AMK). HAPA-B at dose levels of 6.25, 25 and 100 mg/kg/day and AMK at dose levels of 25 and 100 mg/kg/day were given intramuscularly for 30 days. Only one female dog in the AMK 100 mg/kg dose group died on day 29. The activities of urinary NAG and gamma-GTP increased dose-relatedly in dogs in the 25 and 100 mg/kg dose groups of either drug. Discoloration and/or enlargement of the kidneys were observed in dogs at 100 mg/kg of either drug. Hemorrhage and/or edema at the injection sites were observed in dogs in the 25 and 100 mg/kg dose groups of either drug. Increases of absolute and relative kidney weights were observed in the AMK 100 mg/kg group. An increase of relative kidney weights was also observed in the HAPA-B 100 mg/kg group. In microscopic observations, various histopathological changes of renal tubules and tubular epithelium were observed dose-relatedly in the 25 and 100 mg/kg groups of both drugs. At a dose of 25 mg/kg, there was no significant difference of the incidence and severity of these renal changes between HAPA-B and AMK groups. Desquamation and necrosis of the renal tubular epithelium were observed only in the AMK 100 mg/kg group. The necrosis in these changes was considered to be one of the severest possible changes in renal tubules, hence the renal toxicity of HAPA-B was judged to be milder than that of AMK at the dose level of 100 mg/kg. The non-toxic dose of HAPA-B in this study was estimated to be 6.25 mg/kg.

Amikacin↗
PubMed1986

[Efficacy of intracisternal papaverine on symptomatic vasospasm].

This study reports the effect of intracisternal administration of papaverine in 15 patients with vasospasm due to rupture of aneurysm. All patients had undergone clipping of aneurysm and had neurological deterioration and decreasing level of consciousness. Bolus injection of 40 mg of 1% papaverine hydrochloride was started on day 6.3 +/- 1.7 and continued for 4.4 +/- 1.6 days. In seven cases serial angiogram after initial dose revealed dilatation of IC and/or anterior, middle cerebral arteries at 30 min and further dilatation up to 85% increase in diameter at 60 min, which continued at least 90 min. Arteries with marked vasospasm responded more to papaverine than those with less vasospasm. There was a close correlation between degree of vasospasm and vasodilatation effect (r = 0.88, p less than 0.01). In all but two cases vasodilatation tended to become prominent by repeat doses, twice a day, for two to seven days (r = 0.87, p less than 0.01). Vasodilatation was observed only in IC and proximal trunks of ACA and MCA where papaverine could make direct contact, but not in the distal branches beyond A3 or M3. Neurological examination showed improvement of paresis or level of consciousness in 7 cases but no effect in 6 cases. Intracerebral hematoma occurred in two cases (one by high concentration 4% papaverine) during the treatment. Therefore intracisternal papaverine is the treatment of choice in cases with symptomatic vasospasm with some cautions on concentration to be administered.

Cerebral Angiography↗