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Biomedical subjects

K Sakamoto

Publications and source records attributed to K Sakamoto.

At least 721 records · Page 40Linked to original sources
PubMed1989

[Two-color analysis of peripheral blood lymphocytes in patients with malignant tumours after low dose half (or total) body irradiation--a pilot study].

The mechanism of anti-tumour effect of low dose total body irradiation applied for non-Hodgkin's lymphoma is still unknown. Two-color analyses of peripheral blood lymphocytes from ten patients with non-Hodgkin's lymphoma or advanced cancer who received low dose total body irradiation (TBI) or half body irradiation (HBI), were performed to be a help to reveal the mechanism. The results of these analyses indicated that the proportion of helper T lymphocytes, helper-inducer T lymphocytes and cytotoxic T lymphocytes increased during TBI or HBI. On the other hand, the proportion of suppressor-inducer T lymphocytes and suppressor T lymphocytes seemed to decrease slightly. The extent of bone marrow suppression of twice-a-week TBI or HBI was clinically no problem, but in the case of thrice-a-week TBI, prolonged bone marrow suppression might occur. In the case of half body irradiated five patients who were administered with lentinan for several weeks to several months before TBI or HBI, the pre-HBI value of the proportion of cytotoxic T lymphocyte fraction was found to be high, and the increment of the proportion of helper T lymphocyte was larger than that of non-lentinan treated cases.

Aged↗
PubMed1989

Intracellular accumulation of cholesteryl esters suppresses production of lipopolysaccharide-induced interleukin 1 by rat peritoneal macrophages.

Interleukin 1 (IL-1) is a major cytokine of macrophages secreted by several stimulants such as lipopolysaccharide (LPS). Macrophages are known to possess the scavenger receptor for acetylated low density lipoprotein (acetyl-LDL) and maleylated albumin. In the present study we determined effects of these ligands on LPS-induced IL-1 production by rat peritoneal macrophages. These ligands themselves did not induce IL-1 production. However, upon short incubation with acetyl-LDL, LPS-induced IL-1 production was significantly suppressed. The extent of the suppression was proportional to cellular cholesteryl esters. Thus, intracellular accumulation of cholesteryl esters might be responsible for suppression of LPS-induced IL-1 production.

Albumins↗
PubMed1989

Cytotoxicity of bacterial proteases in various tumor cells mediated through alpha 2-macroglobulin receptor.

The binding and cytotoxicity of a complex of fluorescein isothiocyanate-labeled 56K protease and alpha 2-macroglobulin (alpha 2M) were determined by using various human and rodent tumor cell lines. The binding was higher at 37 degrees C than at 4 degrees C; a rapid and progressive uptake that was time dependent was noted at 37 degrees C, whereas no uptake was observed at 4 degrees C, which indicated temperature-dependent internalization. The binding was highest in the fibroblastic and adenocarcinoma cells, and lowest in squamous and epidermoid cells. The Scatchard plots for the binding isotherms were linear, with an apparent Kassoc 1.17 to 2.99 x 10(-8) M for those cells with high alpha 2M receptor. The number of binding sites (alpha 2M receptor) per cell was 1.3 to 4.75 x 10(6). Values for squamous/epidermoid cells were much lower or undetectable. Fluorescent antibody staining indicated that MCF-7 and other cells with alpha 2M receptor internalized the protease-alpha 2M complex, whereas B-16 melanoma, which has little alpha 2M receptor on the cell surface, did not. Furthermore, when the cytotoxicity of this complex was compared with that of different cell lines, the cells with high rates of uptake of the complex required only a low concentration of the protease and vice versa. These results suggest a possible mechanism of cytotoxic action of protease: alpha 2M receptor-mediated endocytosis of the complex followed by destruction of cellular integrity after regeneration of proteolytic activity. Thus, cells with more alpha 2M receptor require only a low dose for cytotoxic action when compared with cells with little alpha 2M receptor.

Adenocarcinoma↗
PubMed1989

Dose dependent effect of diltiazem on the pharmacokinetics of nifedipine.

The effect of diltiazem pretreatment on the pharmacokinetics of nifedipine were determined in six healthy male volunteers. Placebo or diltiazem (30 mg and 90 mg) was given orally three times daily for 3 days in a double-blind, Latin square method. On the fourth day, a 20-mg nifedipine was given orally 1 hour after the last dose of placebo or diltiazem. The mean elimination half-life of nifedipine prolonged significantly following diltiazem (2.54 hours on placebo vs 3.40 hours on 30 mg diltiazem and 3.47 on 90 mg diltiazem, both P less than .01). The mean AUC of nifedipine increased during diltiazem (1726.6 nmol X hr/ml on placebo vs 3838.0 on 30 mg diltiazem, and 5370.0 on 90 mg diltiazem, both P less than .05, 30 mg vs 90 mg, 0.1 less than P less than .05). The ratio of the AUC of primary metabolite (nitropyridine form) to the AUC of nifedipine was reduced by diltiazem pretreatment in a dose-dependent manner. ICG clearance was not influenced following diltiazem. These results indicate that diltiazem dose-dependently alters the pharmacokinetic profiles of nifedipine. The ICG clearance test showed that the liver blood flow did not decrease during diltiazem therapy, therefore, the reduction in the metabolic clearance of nifedipine might be caused by inhibiting effect of diltiazem on the activity of drug oxidizing enzymes.

Adult↗
PubMed1989

Effects of H2-receptor antagonists on plasma aldosterone response to angiotensin II in healthy subjects; (II). Comparison of cimetidine and ranitidine.

The effects of H2-receptor antagonists, cimetidine and ranitidine, on plasma aldosterone response to angiotensin II (AII) were examined in six healthy subjects. The study was carried out on three different occasions with a two week interval. Cimetidine (400 mg), ranitidine (150 mg) or a placebo was given orally every 12 hours for 3 days in a double-blind, cross-over, double-dummy design. On the fourth day, 1 hour after the final (seventh) administration of the same agent, furosemide (20 mg) was injected intravenously. The plasma levels of renin activity (PRA), AII and aldosterone (PA) were determined for a 120 minute period after furosemide. PRA, AII and PA increased after furosemide with as well as without H2-receptor antagonist. The basal and stimulated levels of these parameters were not significantly different at any observation point among the three regimen groups. A significant correlation was observed between AII and PA with placebo (P less than 0.01) and ranitidine (P less than 0.01), but not with cimetidine (P greater than 0.05). The slope of the regression line with ranitidine was not significantly different from that of the placebo. These data indicate that the PA response to AII is blunted by cimetidine, but not by ranitidine. The current study supports the idea that this blunted response during cimetidine is independent of the blockade of H2-receptor.

Administration, Oral↗
PubMed1989

"Skull punch" for craniotomy in neonates and infants.

We have designed a new instrument that we have called a "skull punch" which is useful and safe for making a burr hole for a purely osteoplastic craniotomy in neonates and infants. The instrument is described in detail.

Craniotomy↗
PubMed1989

Synthesis of epidermolysis bullosa acquisita antigen by simian virus 40-transformed human keratinocytes.

The synthesis of epidermolysis bullosa acquisita (EBA) antigen in simian virus 40 (SV40)-transformed human epidermal keratinocytes was studied. Indirect immunofluorescent staining of SV40-transformed keratinocytes employing a serum sample from an EBA patient as a source of antibodies decorated EBA antigen as a perinuclear granular fluorescence. This staining pattern was similar to that of nontransformed epidermal keratinocytes grown in a low Ca2+ medium. In contrast, stratified primary cultures of keratinocytes stained after growth in a high Ca2+ medium showed only small amounts of the antigen localized in the substrate-attached basal cells. To demonstrate biosynthesis of the EBA antigen by SV40-transformed keratinocytes, cells were metabolically labeled with 14C-amino acids and the cell lysates were immunoprecipitated with EBA antiserum. Analysis of immunoprecipitates by sodium dodecylsulfate-polyacrylamide gel electrophoresis and fluorography revealed that the EBA serum precipitated a protein with an apparent molecular weight of 290 kD from extracts of these cells. These results indicate that SV40 induces the synthesis of the 290 kD EBA antigen. Expression of this antigen may be a general feature of nonstratifying, proliferating epidermal cells.

Amino Acids↗
PubMed1989

The value of double-contrast barium enema in amebic colitis.

We report here our findings on the double-contrast barium enema given to 8 patients with amebic colitis and a comparison is made with endoscopic features. A definite diagnosis of amebic colitis was made by fecal examination or by endoscopic biopsy. Radiologic findings included fine marginal serration, aphthoid ulcers, minute barium flecks, marginal defects, loss of haustration, and deformities of the bowel. Aphthoid ulcers and marginal defects are both characteristic of amebic colitis. The double-contrast barium enema is most useful for differentiating amebiasis from other forms of colitis.

Adult↗
PubMed1989

Radiation and surgical stress induce a significant impairment in cellular immunity in patients with esophageal cancer.

The effects of preoperative radiation plus surgical stress on immunity were examined in 29 patients with esophageal cancer, including 14 patients who experienced radiation therapy and 15 who did not, as well as 15 age-, sex- and body weight-matched control subjects. Absolute numbers of the total lymphocytes and OKT3 (all T cells), OKT4 (helper/inducer T cells) and OKT8 (suppressor/cytotoxic T cells) positive lymphocytes were almost the same in both patient groups before treatment. Both the in vitro response to phytohemagglutinin (PHA) and antibody dependent cell-mediated cytotoxicity (ADCC) were depressed in the patients when compared to the controls before treatment. Dual treatment of radiation and surgery led to a marked reduction of lymphocytes in the numbers and activities of PHA and ADCC, when compared to findings in the non-radiation group. Especially, the number of OKT4 positive lymphocytes and the OKT4 to OKT8 ratio decreased most and recovery was slow. While ADCC activity in the non-radiation group recovered at 28 postoperative days (POD), the response to PHA did not return to the pretreatment levels. Serum levels of IgG, IgM and IgA were within normal limits throughout the course of treatment. The B1 (all B cells) positive lymphocytes significantly decreased after the treatments. These results suggest that radiation plus surgery shifts the host immunity toward immunosuppression and induces a significant impairment of cellular immunity in patients with esophageal cancer.

Aged↗
PubMed1989

Glucagon in the metabolic and nutritional management after total pancreatectomy--a case report.

The effects of exogenous glucagon on a totally pancreatectomized patient were evaluated in both the acute postoperative and convalescent periods. In the acute postoperative phase, glucagon stabilized the blood glucose level and allowed the administration of an adequate amount of energy, while during the convalescent period, it proved useful in promoting the metabolism of lipids and amino acids and maintaining liver function. Moreover, we developed a glucagon aerosol which enabled frequent administration without causing major discomfort to the patient and raised the blood glucagon to satisfactory level.

Amino Acids↗
PubMed1989

Inhibition of stress-induced gastric injury in the rat by glutathione.

Glutathione metabolism occurs via interorgan cycles in which hepatic synthesis of reduced glutathione and its transfer to extrahepatic tissues play an important role. To elucidate the physiologic significance of the cycles and tissue thiol status during stress-induced gastric mucosal injury, dynamic aspects of glutathione metabolism were analyzed in rats that were treated with water-immersion restraint. This treatment induced gastric mucosal lesion with concomitant decrease in the levels of perchloric acid-soluble thiols in various tissues, particularly in the liver and stomach. During the treatment, glutathione levels markedly decreased in the liver but not in other tissues. Depletion of hepatic glutathione by buthionine sulfoximine, a specific inhibitor for gamma-glutamyl cysteine synthetase, markedly decreased hepatic glutathione levels and increased the gastric injury. Intraperitoneal injection of reduced glutathione significantly increased plasma levels of glutathione and inhibited the occurrence of gastric injury without affecting intracellular glutathione levels. These results indicate that extracellular glutathione and its interorgan metabolism might play a critical role in the protection of gastric mucosa particularly when animals were challenged with various stress.

Acetylcysteine↗
PubMed1989

Fundamental study on latex reagents for agglutination tests.

Competitive adsorption of Fab and Fc fragments on to particles revealed that the main driving forces for the adsorption of Fab and Fc fragments are ionic and hydrophobic forces, respectively. Latex particles were sensitized with antihuman C-reactive protein-antibody under a condition where ionic binding force was suppressed, and hence antibody was supposed to attach to the particles predominantly at the Fc site. The resulting latex indicated a high efficiency for the determination of C-reactive protein. Among the latexes used, a partially hydrolysed styrene-acrylamide copolymer latex was the best with respect to test efficiency and storage stability.

Adsorption↗
PubMed1989

Erythema dyschromicum perstans. Immunopathologic studies.

Immunopathologic studies of a patient with clinical and histologic evidence of erythema dyschromicum perstans revealed Ia antigen expression on epidermal keratinocytes, pronounced OKT4 and OKT6 staining of epidermal dendritic cells, and dermal infiltration of T lymphocytes of both helper-inducer (OKT4) and suppressor-cytotoxic (OKT8) phenotypes--a pattern commonly associated with lichen planus. These findings, taken in conjunction with positive IgG staining on colloid bodies, suggest the possibility that erythema dyschromicum perstans and lichen planus have similar disease processes.

Adolescent↗
PubMed1989

Subacute cutaneous lupus erythematosus lesions precipitated by griseofulvin.

Skin eruptions with features of subacute cutaneous lupus erythematosus occurred in a patient with dermatomyositis who was taking griseofulvin. The patient had antibodies against SSA/Ro and SSB/La antigens. Skin rashes disappeared after discontinuation of griseofulvin and recurred on challenge with the drug. These findings support previous studies that the photoactive drug may be synergistic with anti-SSA/Ro antibody to produce lesions of subacute cutaneous lupus erythematosus.

Adult↗
PubMed1989

Brunner's gland hamartoma associated with microcarcinoids.

We report on the case of a 51-year-old female with a pedunculated duodenal tumor that was covered with normal duodenal mucosa. Histology of the endoscopically resected tumor revealed Brunner's gland adenoma with two foci of microcarcinoids. To our knowledge, such a case has not been reported in the literature.

Adenoma↗