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Biomedical subjects

M Kitamura

Publications and source records attributed to M Kitamura.

At least 37 records · Page 2Linked to original sources
PubMed1992

[Experimental study of the treatment of carcinomatous peritonitis in gastric cancer].

To prevent dissemination to the peritoneum following surgery for gastric cancer, examinations were performed with mouse ascites cancer models and the objective of enhancing the combined effect of MMC, CDDP and 5-FU. Pharmaceutical dosage was set at approximately 30% of the increased life span (ILS) for Meth-A. The dosage was 0.2 mg/kg for MMC, 1 mg/kg for CDDP and 37.5 mg/kg for 5-FU. Results indicated that simultaneous combination of 0.2 mg/kg of MMC and 1 mg/kg of CDDP extended life significantly more than individual administration, and clinical application of this combination was considered to be possible. In contrast, simultaneous combination of 1 mg/kg of CDDP and 37.5 mg/kg of 5-FU had no clear life-extending effect compared to individual administration of each. Some biochemical modulation of the administration method was thus considered necessary.

Animals↗
PubMed1992

[Effective treatment of liver metastasis and peritoneal dissemination of gastric cancer using intra-arterial therapy--a case report].

A 56-year-old man who had undergone curative gastrectomy for Borrmann 2 type gastric cancer 43 months before, had a cancer recurrence (liver metastasis and peritoneal dissemination). Intra-arterial hypertensive chemotherapy with MMC for liver metastasis and intra-arterial sequential MTX/5-FU chemotherapy for peritoneal dissemination were given. He died of lung cancer with brain metastasis 27 months after this therapy. But in autopsy the remarkable effects of chemotherapy were recognized in intra-abdominal recurrent sites, and in fact, microscopically no cancer cells were found in metastatic lesions. We thus concluded that intra-arterial noradrenaline-induced hypertensive MMC therapy for liver metastasis and intra-arterial sequential MTX/5-FU therapy for peritoneal dissemination were useful treatment.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1992

[A case report of thrombosed St. Jude Medical valve in a patient with macroglobulinemia].

A 66-year-old man who had undergone MVR using a ST. Jude Medical valve entered the hospital with acute heart failure and cardiogenic shock 3 months after surgery. He had had a symptom of petechiae due to macrogloburinemia after initial MVR and had been in the poor control of anticoagulation therapy because of presence of petechiae. He was diagnosed as prosthetic valve thrombosis using echocardiography and underwent emergency re-MVR using a Central Open Bioprosthesis (COB) which was developed by our department. He was doing well 8 month after re-MVR. Selection of prosthetic valve should be performed carefully in the patient with hemorrhagic disease, and careful observation and proper anticoagulant therapy should be carried out after valve replacement.

Aged↗
PubMed1992

[Growth retardation in children with frequent relapsing nephrotic syndrome on steroid--improvement of height velocity after administration of immunosuppressive agent].

In a study involving 22 cases of nephrotic syndrome in children, investigations were made of growth disturbance caused by corticosteroid in relation to dose of the steroid and age levels at steroid treatment and also of the effects of concomitantly used immunosuppressive drugs. The final height of frequent relapsing nephrotic syndrome was below M-2SD in approximately 30% of cases. Final heights of boys receiving the steroid from 12 to 16 years of age and of girls treated with the steroid from 10 to 14 years of age were below M-2SD and 10 cm lower than the target height. Final heights of boys and girls who could be withdrawn from steroid therapy by the age of 14 and 12, respectively, were invariably within or above the normal range. The addition of azathioprine therapy resulted in no appreciable reduction of steroid dosage nor improvement of yearly growth rate, although the frequency of relapse for that year was diminished. Under a regimen of concomitant cyclophosphamide the frequency of relapse and steroid dosage was also reduced but the growth rate was accelerated, no significant reduction of steroid consumption was achieved. The administration of cyclosporin A in doses of 1.5-5.0 mg/kg was marked by a reduction in steroid dosage as well as in the frequency of relapse and allowed for near normal growth rate, with no significant differences being observed between the high dose group (3-5 mg/kg/day) and the low dose group (1.5-2.5 mg/kg/day). Prolonged steroid therapy in frequent relapsing nephrotic syndrome may produce dwarfism and other distressing side effects.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1991

Changes in binding activity of luteinizing hormone receptors by site directed mutagenesis of potential glycosylation sites.

Site directed mutagenesis of the rat ovarian luteinizing hormone (LH) receptor cDNA was performed at each of the six potential N-linked glycosylation sites to determine the effect of putative carbohydrate chains on the activity of the membrane receptor. The conversion of Asn173 to Gln resulted in the total loss of hormone binding to the surface of the transfected cell. Mutant receptors synthesized with substitutions at the remaining potential N-linked glycosylation positions of 77, 152, 269, 277 and 291 revealed no significant change in the hormone affinity. However Asn77Gln and Asn152Gln exhibited significant decreases (approximately 80%) in the number of high affinity hormone binding sites. The changes in hormone binding activity upon elimination of the potential glycosylation sites at 77, 152 and 173 indicate the presence of functional carbohydrate chains at these positions in the rat ovarian LH/hCG receptor.

Animals↗
PubMed1991

A new method for the determination of adenine phosphoribosyltransferase activity in human erythrocytes by reversed phase high performance liquid chromatography.

A new method for the determination of adenine phosphoribosyltransferase (APRT) activity in human erythrocytes is described. APRT activity was assayed by a non-radiochemical method in which adenosine monophosphate (AMP) and AMP metabolites produced from a substrate adenine were converted to inosine by alkaline phosphatase and adenosine deaminase. The inosine thus produced was quantitated by reversed phase HPLC. This method was simple, precise, sensitive and free from interference with other co-existing erythrocyte enzymes. Four patients with 2,8-dihydroxyadenine urolithiasis and others with several disorders in purine metabolism have been studied, showing that the present method is clinically useful for the diagnosis and the evaluation of the severity of some human diseases.

Adenine Phosphoribosyltransferase↗
PubMed1991

Quality control program on biological monitoring by Japan Federation of Occupational Health Organizations.

Since 1980, the Japan Federation of Occupational Health Organizations has been conducting an external quality control survey for biological monitoring under a contract with the Ministry of Labour of the Japanese Government. The number of participating organizations has increased from 91 in 1980 to 179 in 1987. The items in the program were lead and free erythrocyte protoporphyrin concentrations in blood, and lead, coproporphyrin, delta-aminolevulinic acid, chromium, hippuric acid, methylhippuric acid, total trichloro-compounds, mandelic acid, and phenol concentrations in urine. Evaluation was based on a scoring system. The scores were on the slope of major axis for probable ellipse, the slope of regression line, square root of error mean square for regression, performance indices, and the difference between 'true' and observed values of each sample. There was a gradual improvement in the evaluation scores as a function of time. The improvement was paralleled by the adoption of modern analytical methods such as flameless atomic absorption spectrometry for blood-lead measurement and high-performance liquid chromatography for urinary hippuric acid determination in many participants. These methods are simple in operation and reliable in performance. It was considered very probable that the program promoted the adoption.

Environmental Monitoring↗
PubMed1991

Frank melena in a patient with fallopian tube pregnancy.

We present herein a case of a young woman who experienced lower intestinal hemorrhage caused by ischemic necrosis of the small intestine induced by the compression of a Fallopian tube hematoma in an ectopic pregnancy. All accessible preoperative attempts to clear the site of the bleeding were unsuccessful and an exploratory laparotomy was indicated seventeen days after the development of melena. An ileocecal resection and right salpingectomy finally had to be performed.

Adult↗
PubMed1991

Extracellular matrix contraction by cultured mesangial cells: an assay system for mesangial cell-matrix interaction.

To investigate the interaction between glomerular mesangial cells (MCs) and extracellular matrix (ECM), we have developed a quantitative assay using a floating culture of MC-populated collagen gel matrix (MCGM). Since MCs can contract such a matrix consisting of type I collagen, MCGM exhibited marked contraction. The apparent cause was tensional interaction between MCs and collagen fibers, because: (1) MCs in the gel attached tightly to surrounding collagen fibers; (2) collagen fibrils surrounding MCs were ordered in a radial array; (3) collagen fibers aggregated around MCs in the contracted gel, but not in an uncontracted gel; (4) cytochalasin B, an actin polymerization blocker, inhibited gel contraction in a dose-dependent manner. We found that this interaction was modulated by some factors. Serum in the medium stimulated the contraction of MCGM. The degree of MCGM contraction was proportional to the number of MCs embedded above 2.3 x 10(4) cells/ml of gel. In MCGM containing a basement membrane-type gel matrix (BGM), gel contraction was increasingly inhibited as the content of BGM rose. Our method is useful for elucidating physiological and pathological interactions between MCs and ECM.

Angiotensin II↗
PubMed1991

Mesangial cell behavior in a three-dimensional extracellular matrix.

To understand the role of mesangial matrix in regulating responses of mesangial cells (MCs), particularly as a cause of disease, we examined the behavior of MCs cultured in a three-dimensional extracellular matrix (ECM). Mouse and rat MCs were incorporated into ECM composed of type I collagen gel matrix (CGM) and basement membrane-type gel matrix (BGM), and their shape and proliferation were assessed. The effect of gel matrix on MC migration was also studied. MCs exhibited marked elongation and proliferation in CGM, whereas these behavior were inhibited by increasing the ratio of BGM. Although CGM allowed MC migration, BGM restricted it to a great extent. To identify the cause of our findings, we examined the effects of ECM components in our experimental system. Laminin, fibronectin, type IV collagen, and heparin-like proteoglycans (heparan sulfate and heparin) were each mixed separately with CGM at a concentration of 50 micrograms/ml gel. Whereas fibronectin promoted MC elongation and proliferation, and laminin inhibited MC migration, type IV collagen and heparin-like proteoglycans inhibited all three activities of MCs. Our findings suggest that basement membrane-type mesangial matrix is important in regulating the behavior of MCs in vivo.

Animals↗
PubMed1991

Relationships between serum thyroid stimulating hormone levels and development of thyroid tumors in rats treated with N-bis-(2-hydroxypropyl)nitrosamine.

Relationships between serum thyroid stimulating hormone (TSH) levels, carcinogen dose and development of thyroid tumors were studied in Wistar rats of both sexes treated with N-bis-(2-hydroxypropyl)nitrosamine (DHPN). DHPN (210 mg/100 g body wt) was injected i.p. weekly. Wistar rats were used, divided into five groups of males (M1-M5) and five groups of females (F1-F5). M1 and F1 received one injection of DHPN, M2 and F2 two injections of DHPN, M3 and F3 three injections of DHPN, M4 and F4 four injections, and M5 and F5 as control rats received saline vehicle. The resultant incidences of total thyroid tumors were 4% in group M1, 24% in M2, 80% in M3, 76% in M4, 0% in F1, 4% in F2, 20% in F3, 17% in F4 and 0% in M5 and F5. Thus dose dependence for DHPN carcinogenesis was found in both sexes for up to at least three injections of DHPN and in all cases males proved more susceptible than females. Similar results were gained for carcinomas treated separately. A sex difference in DHPN induction of thyroid tumor was thus shown for Wistar rats opposite to that reported to exist in humans. However, no clear relationship between dose of DHPN or incidence of thyroid tumors and serum TSH concentration was evident at the end of the experiment (week 30).

Adenoma↗
PubMed1991

Topical chemotherapy in human periodontitis using a new controlled-release insert containing ofloxacin. I. Microbiological observation.

The recognition that destructive periodontal diseases may be caused by specific microorganisms in periodontal pockets has led to an increased interest in and usage of antimicrobial agents in periodontal therapy. Recently, a new controlled-release insert containing ofloxacin, a synthetic antibiotic, has been developed. In this study, the controlled-release insert (PT-01) was microbiologically evaluated in combination with or without subgingival mechanical debridement. PT-01 was applied in the periodontal pockets of 27 patients with chronic periodontitis. Three sites with a deep probing pocket depth (greater than or equal to 5 mm) were randomly selected in different quadrants of each patient, and were assigned into three groups, i.e., PT-01 applied (T), placebo applied (P) and control sites (C). Periodontal treatments consisted of supragingival scaling with oral hygiene instruction for the first 2 weeks followed by root planing and subgingival scaling PT-01 was applied weekly on day 0 to 35, and the subgingival plaque samples from each site were collected on d 0, 14, 21 and 42. The dynamics of the subgingival microflora was investigated by dark field microscopy and by anaerobic and aerobic cultivation. In the supragingival scaling period, significant reduction in percentages of spirochetes and motile rods and significant increase of the percentage of coccoid cells were observed only at T sites. In addition, the total viable counts of bacteria, black-pigmented Bacteroides and Fusobacterium species were significantly reduced at T sites. After mechanical subgingival debridement, significant shifts in the proportion and reduction of the viable counts in the subgingival microflora were found at all sites.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Topical↗
PubMed1991

Immunohistochemical detection of estrogen receptors in paraffin sections of human thyroid tissues.

The optimal demonstration of estrogen receptor binding in thyroid tissues was made under conditions of 10% protease in 50 mM Tris-HCl buffer (pH 7.6) for 10 min as the pretreatment digestion step, incubation of primary antibody (ER-ICA monoclonal kit; Abbott Laboratories) at 37 degrees C for 2 h and incubation of secondary antibody (ABC kit; Vector) at 37 degrees C for 40 min. Thyroid tissues used for assessing the reaction were 17 cases of goiter, 25 adenoma cases, 27 cases of papillary carcinoma, 14 cases of follicular carcinoma and 10 latent cancer cases. Incidences of positive estrogen receptor reaction were 22% (11/51) for all thyroid cancers, 20% (5/25) for the thyroid adenomas and 59% (10/17) for goiters. 15% (4/27) of papillary carcinomas, 21% (3/14) of follicular carcinomas and 40% (4/10) of latent cancers proved positive, the estrogen receptor reaction being limited to the nuclei of thyroid follicular/papillary type cells.

Deoxyribonucleases↗
PubMed1991

Dissociation of hydroxylase and lyase activities by site-directed mutagenesis of the rat P45017 alpha.

Site-directed mutagenesis of the arginine-rich region within the putative active site of the rat testicular P45017 alpha (17 alpha-hydroxylase cytochrome P-450, the product of P450XVII gene) was performed to identify specific amino acids that contribute to either the hydroxylase or lyase activities catalyzed by this enzyme. The conversion of Arg346 to alanine differentially abolished lyase activity without affecting hydroxylase activity, resulting in an accumulation of the 17 alpha-hydroxylated intermediate, and partial lyase activity was recovered by conversion of this mutant to Lys346. Similar results were obtained with the conversion of Arg357 to alanine, although this mutant also diminished hydroxylase activity, and full lyase and hydroxylase activities were recovered with a lysine in this position. Major reductions in hydroxylase activity were apparent with the conversion of Arg363 to Ala, and this inhibition was reversed by a lysine at position 363. In contrast, differential effects were not observed with the mutants Arg361 Ala, Arg361 Lys, or Tyr334Phe. Both mutations at the Arg361 position resulted in a total loss of hydroxylase and lyase activities, and mutation at the Tyr334 position had no effect on either activity. The identification of specific amino acids that are essential for either the hydroxylase or lyase reaction indicates that the steroid substrate-protein interaction changes during the course of the two consecutive reactions and reveals the potential for separation of the two activities by chemical and biological modulators within the active site region of the P45017 alpha.

Aldehyde-Lyases↗
PubMed1991

Binding of a factor to an enhancer element responsible for the tissue-specific expression of the chicken alpha A-crystallin gene.

We have characterized a regulatory region of the chicken alpha A-crystallin gene using transfection assays, which revealed that a 84 base pair element (-162 to -79) in the 5' flanking sequence is necessary and sufficient for lens-specific expression. A multimer of this element functions as lens-specific enhancer and synergistically activates transcription from chicken alpha A-crystallin or beta-actin basal promoters fused to the CAT gene. In vivo competition experiments demonstrated that DNA sequences containing the 84 bp element reduced alpha A-crystallin-CAT fusion gene expression. A nuclear factor present exclusively in lens cells binds to the 84 bp element in the region between positions -165 and -140. Southwestern blot analysis showed that 61,000 Mr (61 x 10(3) Mr) lens nuclear protein exhibited DNA-binding activity specific to the 84 bp element. Our data suggested that the 61 x 10(3) Mr nuclear protein, and the 84 bp element that it interacts with, may be involved in regulating the alpha A-crystallin gene expression in vivo.

Animals↗
PubMed1991

2-Oxo-1,3-dioxoles as specific substrates for measurement of arylesterase activity.

Various 4-arylthiomethyl-2-oxo-1,3-dioxole derivatives IIIa-o were synthesized. Their hydrolysis rates by arylesterase (EC 3.1.1.2) and cholinesterase (EC 3.1.1.8) in human serum were evaluated. Some of them were not hydrolyzed by cholinesterase, but were hydrolyzed easily by arylesterase. Among the substrates, sodium 4-((5-methyl-2-oxo-1,3-dioxol-4-yl)methylthio)benzenesulfonate (IIIg) was selected for its substrate reactivity toward arylesterase and its good water solubility. In addition, neither aliesterase (EC 3.1.1.1), acetylesterase (EC 3.1.1.6) nor cholesterol esterase (EC 3.1.1.13) hydrolyzed the compound. IIIg is thus concluded to be a specific substrate for arylesterase. Our assay system for serum arylesterase using IIIg can be readily applied to an automatic analyzer in the diagnosis of liver cirrhosis.

Carboxylic Ester Hydrolases↗
PubMed1991

[Bile duct necrosis and hepatic necrosis following hepatic arterial infusion chemotherapy].

Three cases of bile duct necrosis owing to hepatic arterial infusion chemotherapy (HAI) were reported. Regarding HAI, transcatheter hepatic arterial embolization (TAE) was applied in two cases (hepatocellular carcinoma: 1; metastasis: 1) and 5-fluorouracil (continuous) combined with leucovorin (one shot) therapy (LV + 5-FU) was given to one metastatic case. In the data of blood biochemistry, serum alkaline phosphatase, gamma-glutamyl transpeptidase, and leucine aminopeptidase values characteristically elevated without the elevation of total bilirubin value. Hepatic tumors degenerated with necrosis in all cases and no viable cells were histologically recognized. Although the destruction of bile ducts was locally detected adjacent to these tumors in TAE cases and was more widespread in the LV + 5-FU case, these lesions were very similar in each case. Therefore, we concluded that both ischemia and drug toxicity induced bile duct necrosis and the necrosis around the bile duct was the secondary change due to the leaked bile juice.

Aged↗