Biomedical subjects

R Kobayashi

Publications and source records attributed to R Kobayashi.

At least 289 records · Page 16Linked to original sources

PubMed1993

Distribution and abundance of neutral endopeptidase (EC 3.4.24.11) in the alimentary tract of the rat.

The distribution of neutral endopeptidase (NEP; EC 3.4.24.11) was examined in the alimentary tract of the rat. Immunoreactive NEP and NEP mRNA were localized to epithelial cells of the small intestine and to muscle cells in the stomach, small intestine, and colon by immunohistochemistry and in situ hybridization histochemistry. NEP antisera recognized a protein on Western blots of membranes from gastric, jejunal, and colonic mucosa and gastric muscle with an electrophoretic mobility identical to that of recombinant human NEP (approximately 95 kDa). An antisense cRNA probe to NEP hybridized to RNA of approximately 3.5 kb and approximately 6.5 kb, corresponding to the primary transcripts of rat NEP, on Northern blots of total RNA from the jejunal mucosa. NEP message was detected in mRNA from jejunal and colonic mucosa and gastric, jejunal, and colonic muscle using a ribonuclease protection assay. NEP enzymatic activity, assessed by DL-thiorphan-inhibitable degradation of glutaryl-Ala-Ala-Phe-4-methoxy-2-naphthylamine, was highest in homogenates of jejunal mucosa (868 +/- 98 pmol.h-1 x micrograms protein-1) and was between 49- and 413-fold lower in other gastrointestinal tissues. The cellular origin of NEP in the gastric and colonic mucosa could not be determined.

Animals↗

PubMed1993

Role of angiotensin II in high fructose-induced left ventricular hypertrophy in rats.

Recent studies suggest the linkage of hypertension and insulin resistance. High fructose diet is known to induce hyperinsulinemia and hypertension in rats. In a previous study, however, high fructose (66%) diet failed to elevate blood pressure but increased left ventricular weight in Sprague-Dawley rats. In the present study, we investigated the precise mechanism of high fructose diet-induced changes in the cardiovascular system in rats. Intake of fructose-enriched diet for 2 weeks increased serum insulin and plasma angiotensin II levels. Urinary excretion of sodium and norepinephrine was not changed. Blood pressure measured directly through an indwelling catheter was not increased, but left ventricular weight and protein content were increased by high fructose diet. To further elucidate the role of the renin-angiotensin system, an angiotensin II type 1 receptor antagonist, TCV-116, was given orally at 1 mg/kg per day with either normal or high fructose diet. Concomitant administration of TCV-116 did not affect plasma glucose or serum insulin levels. Plasma angiotensin II was increased, but neither urinary sodium nor norepinephrine was changed by TCV-116. TCV-116 similarly decreased blood pressure in rats on normal and high fructose diets. Increase in left ventricular weight induced by high fructose diet was prevented by the concomitant administration of TCV-116. On the other hand, left ventricular weight in control rats was not changed by TCV-116. In conclusion, increased plasma angiotensin II may account for the left ventricular hypertrophy induced by high fructose diet, whereas hemodynamic change, sodium retention, and the sympathetic nervous system do not play an important role.

Angiotensin II↗

PubMed1993

Activation and differentiation antigens on T cells of healthy, at-risk, and HIV-infected children.

We examined the T-lymphocyte phenotypes of 67 human immunodeficiency virus (HIV)-infected children (P-1 or P-2) and 65 age-matched, healthy, control children stratified into four groups from < 1 to > or = 5 years of age to determine expression of antigens associated with cell activation/differentiation. Immunophenotyping was performed by laser flow cytometry using two-color immunofluorescent labeling. Although the control children showed a decline in total CD4 cell percent with age, the HIV-infected children in all age groups showed significantly decreased CD4 cell numbers compared with the age-matched controls. However, the slope of the CD4 cell decline with age was not significantly different in HIV-infected and control children. The CD4 cell decrease in infected children was reflected in both the CD45RA+ (naive) and CD45RA- (memory) CD4 cell subsets, although the CD45RA+ cells were decreased in greater proportion. Results assessing CD4 cells for expression of the L-selectin (Leu8) molecule were similar to those for CD45RA. The overall CD8 cell percentage was significantly increased in HIV-infected children compared with controls in all age groups. This was due primarily to increases in CD8 cells that were CD38+, CD57+, HLA-DR+, or CD45RA-. In a retrospective analysis of data from 23 P-0 children, we compared phenotype results from 5 children who were HIV+ with those 18 who were HIV-. Although the phenotypic changes seen in the 5 HIV+ children paralleled those described above for P-1 and P-2 subjects, there was no significant difference in the values for HIV+ compared with HIV P-0 children. Although the phenotypic alterations described did not appear to be diagnostic markers in P-0 children, they may serve as useful adjuncts for the evaluation of HIV-infected children.

ADP-ribosyl Cyclase↗

PubMed1993

[Fulminant hepatitis-like veno-occlusive disease of the liver after allogeneic bone marrow transplantation in acute lymphoblastic leukemia].

A 14-year-old girl with acute lymphoblastic leukemia in second remission received an allogeneic marrow graft from her HLA identical brother. Cyclosporine A and short term methotrexate were given for prophylaxis against graft versus host disease. On day 42 post transplantation elevation of SGOT and SGPT was recognized, rising the next day to 8,560IU and 2,590IU, respectively. Prothrombin activity dropped below 10%. HCV antibody and HBs antigen were both negative. Fulminant hepatitis was diagnosed, therefore plasma exchange was initiated. However, hepatic encephalopathy developed and she died on day 57. The postmortem liver appearance was consistent with early changes of veno-occlusive disease. Such atypical cases of VOD with late onset are difficult to distinguish from fulminant hepatitis but should be kept in mind.

Adolescent↗

PubMed1993

A comparative analysis of nasal secretions from subjects with and without acute rhinitis and its application to forensic medicine.

Proteins in nasal secretions obtained from healthy subjects and subjects with acute rhinitis were analyzed by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). The bands of 79 kilodalton (kD), 67 kD, 58 kD, 52 kD, 43 kD, 38 kD, 28 kD, 26 kD and below 26 kD were the proteins shared by most specimens. The state of the common cold was identified by determining the ratios of these proteins to the total proteins. 58 kD protein (IgA alpha-chain), contained mainly in glandular secretions, was found in abundance on average. However, the ratio of 67 kD protein (albumin) filtrated from the vascular system varied considerably. The highest ratio of 67 kD protein (albumin) was found in the nasal secretions obtained only from subjects with rhinitis. In nasal secretions from healthy subjects, the highest ratios of the major proteins were those of 58 kD protein (IgA alpha-chain) or proteins below 26 kD. These observations may be useful in discriminating rhinitis subjects with a common cold from healthy subjects in the forensic medical analysis of nasal smears.

Acute Disease↗

PubMed1993

[Two cases of re-expansion pulmonary edema following decortication of tuberculous empyema].

Two cases of re-expansion pulmonary edema following decortication of a tuberculous empyema are presented. The period of compression of the whole lung by empyema was relatively short in both cases. One case showed incomplete expansion of the whole right lung after preoperative drainage, and re-expansion pulmonary edema of the whole right lung after decortication, which was treated by mechanical ventilation and steroid therapy. The other case showed incomplete expansion of the right middle and lower lobes after preoperative drainage, and re-expansion pulmonary edema of the right middle and lower lobe after decortication, which was treated by steroid therapy. In cases of tuberculous empyema with a relatively short course, re-expansion pulmonary edema may occur in a lung incompletely expanded by preoperative drainage.

Adult↗

PubMed1993

[Clinical studies of 4 pneumonia cases occurring more than one month after surgery of lung cancer].

We studied four cases who died of post-operative pneumonia occurring more than one month after surgery for lung cancer, despite a satisfactory post-operative course. All cases were male and smoker over 70 years old, who were performed of operation through posterolateral thoracotomy. As a control, we used 11 cases over 70 years old and smoker undergoing surgery for lung cancer through posterolateral thoracotomy, who returned to everyday life without a problem. The body mass index of all pneumonia cases was less than 20, which was significantly lower than that of control cases in both pre- and post-operative time (p < 0.05 and p < 0.01). Post-operative serum total protein and albumin in pneumonia cases was significantly lower than in control cases (p < 0.01). As a result, we suggest that males and smokers over 70 years old with lung cancer, whose body mass index were less than 20, require careful nutritional care over a long period after surgery.

Aged↗

PubMed1993

[A case of empyema with bronchopleural fistula associated with diabetes and renal failure treated utilizing omental and muscle flap].

The patient was a 75-year-old male who had a right empyema with bronchopleural fistula, which had developed after right upper lobectomy for pulmonary tuberculosis performed 18 years previously. He also had diabetes and renal dysfunction. The fistula failed to close 5 months after open drainage thoracotomy. Accordingly, closure was performed by the intrathoracic transposition of an omental and muscle flaps obtained from the right latissimus dorsi, pectoralis major, and pectoralis minor. At 70 days after the closure, the fistula reopened due to his poor nutritional state, but it closed again spontaneously following intravenous hyperalimentation. In those patients who have empyema with bronchopleural fistula associated with diabetes or renal dysfunction, long-term postoperative care, especially nutritional management, is necessary because of their poor general health condition.

Aged↗

PubMed1993

[A case of myasthenia gravis developing after resection of non-invasive thymoma].

The patient was a 79-year-old male. On CT of the chest, a mass shadow of the anterior mediastinum was found. He did not complain of symptoms, and there were no clinical signs of myasthenia gravis (MG) before surgery. The tumor and the thymus was completely resected. The pathological diagnosis was non-invasive thymoma, and his postoperative course was satisfactory. However, 2 months after the operation, the patient complained of ptosis, diplopia, dysphagia, and muscle weakness, which deteriorated rapidly. The titer of anti-acetylcholine receptor antibody was high at 91.0 nmol/l. By medication of anti-cholinesterase drug and predonin, the symptoms of MG improved. After resection of thymoma, postoperative follow-up with considering the possibility of postoperative MG is necessary.

Aged↗

PubMed1993

[A case of an intra-pericardial bronchogenic cyst requiring an emergency operation].

The patient was a 36-year-old male, who complained of anterior chest pain and dyspnea. A chest X-ray showed a cardiac enlargement and widened tracheal carina. A cardiac echography showed an intra-pericardial simple cyst which was fixed and did not move with cardiac motion. CT showed a cyst, measuring to 10 cm between the left atrium and vertebra. An angiography revealed that the left atrium and right main pulmonary artery were compressed in the anterior direction. Because his symptoms deteriorated suddenly, an emergency operation was performed. The intrapericardium was explored through the right postero-lateral thoracotomy, and the cyst was resected. A microscopic examination revealed that the cystic wall was lined with ciliated columnar epithelium and contained cartilage and bronchial gland. Review of the literatures indicated that the most of the intra-pericardial bronchogenic cysts were revealed as cardiac enlargement by chest X-ray film, and that the cyst compressing the atrium or main pulmonary artery should be resected without delay, because of a risk of sudden death or cardiac failure.

Adult↗

PubMed1993

[Autopsy case of non-invasive thymoma associated with pancytopenia and hypogammaglobulinemia].

A 57-year-old male presented with palpitations and dyspnea on exertion. Examination of the peripheral blood and bone marrow showed pancytopenia with marked red cell aplasia. Hypogammaglobulinemia was also recognized. Chest X-ray and CT showed a mass in the anterior mediastinum. A biopsy showed thymoma. Two months after admission, the patient died of sepsis secondary to worsening pancytopenia and hypogammaglobulinemia. Autopsy showed non-invasive spindle cell type thymoma and a marked decrease of hematogenous cells. Review of the literature indicates that pancytopenia associated with thymoma is resistant to all forms of treatment and its prognosis is poor.

Agammaglobulinemia↗

PubMed1992

Calcyclin and calvasculin exist in human platelets.

Using Ca(2+)-dependent affinity chromatography on a synthetic compound (W-7)-coupled Sepharose column, three distinct Ca(2+)-binding proteins have been identified in human platelets. The molecular mass of these three distinct proteins was estimated to be 10, 10.5, 17 kDa, respectively, by polyacrylamide gel electrophoresis in the presence of SDS. The partial amino acid sequence revealed these proteins have EF-hand structures and high homology to the predicted proteins, calcyclin, calvasculin, and calmodulin. Calcyclin and calvasculin have been considered as probably having roles in the control of cell proliferation, but the existence of these two proteins in platelets suggests that they have other intracellular functions related to the Ca(2+)-signal transduction system.

Amino Acid Sequence↗

PubMed1992

Epstein-Barr virus-induced human B-cell lymphomas in SCID mice reconstituted with human peripheral blood leukocytes.

Epstein-Barr virus (EBV) infection is associated with immunoblastic B-cell lymphomas in immunosuppressed or human immunodeficiency virus-infected individuals and in SCID mice reconstituted with human peripheral blood leukocytes (hu-PBL-SCID) from EBV-seropositive donors. The risk of tumors appearing in the hu-PBL-SCID mice differs among EBV-seropositive donors. Four different outcomes have been noted: (a) no tumors appear (no incidence donors); (b) tumors appear in a fraction of hu-PBL-SCID mice with a 10-20 week latent period (low- and intermediate-incidence donors); or (c) tumors appear in all hu-PBL-SCID mice within 6-10 weeks (high-incidence donors). The latter category of rapidly appearing tumor invariably involved activation of EBV replication, whereas more slowly growing tumors rarely activated EBV. The results indicate that prospective screening of high-risk individuals in the hu-PBL-SCID model may predict the risk of EBV-associated lymphoma development.

Animals↗

PubMed1992

Neurocalcin: a novel calcium-binding protein from bovine brain.

A novel calcium-binding protein (molecular weight 23,000-24,000, pI 5.3-5.5), which we term neurocalcin, was identified in bovine brain. Using calcium-dependent drug affinity chromatography ((S)-P-(2-aminoethyloxy)-N-[2-(4-benzyloxycarbonylpiperazinyl++ +)-1-(P- methoxybenzyl)ethyl]-N-methylbenzene-sulfonamide dihydrochloride, W-77, -coupled Sepharose 6B), we purified neurocalcin from bovine brain. The partial amino acid sequence of neurocalcin revealed it to be an as yet unidentified protein with three putative calcium binding sites (EF-hands). Further purification and sequence analysis demonstrated the presence of four isoprotein forms designated alpha, beta, gamma 1, and gamma 2. When the 165 sequenced residues of neurocalcin beta are compared with sequences of other proteins, neurocalcin beta has a 38.2% sequence homology with visinin and 45.5% with recoverin (Yamagata, K., Goto, K., Kuo, C.-H., Kondo, H., and Miki, N. (1990) Neuron 2, 469-476; Dizhoor, A. M., Ray, S., Kumar, S., Niemi, G., Spencer, M., Brolley, D., Walsh, K. A., Philipov, P. P., Hurley, J. B., and Stryer, L. (1991) Science 251, 915-918). Both visinin and recoverin are expressed specifically in retinal photoreceptors and are not found in brain. Unlike visinin and recoverin, neurocalcin is purified not only from retina but also from bovine brain. Our results suggest that neurocalcin is a recoverin-like protein expressed in bovine brain.

Amino Acid Sequence↗

PubMed1992

Calvasculin, an encoded protein from mRNA termed pEL-98, 18A2, 42A, or p9Ka, is secreted by smooth muscle cells in culture and exhibits Ca(2+)-dependent binding to 36-kDa microfibril-associated glycoprotein.

Calvasculin, an EF-hand protein with a molecular mass of 11 kDa on sodium dodecyl sulfate-polyacrylamide gel electrophoresis, is present abundantly in bovine aorta (Watanabe, Y., Kobayashi, R., Ishikawa, T., and Hidaka, H. (1992) Arch. Biochem. Biophys. 292, 563-569). This protein is synthesized constitutively by bovine aortic smooth muscle (BASM) cells and rat embryo fibroblast 3Y1 cells in culture. We discovered that calvasculin was secreted by BASM cells and 3Y1 cells. Immunofluorescence staining of BASM cells showed a granular distribution for calvasculin that was typical of a secreted protein. This protein bound with an extracellular matrix protein, 36-kDa microfibril-associated glycoprotein (36-kDa MAP), in a Ca(2+)-dependent manner in vitro. A stoichiometry analysis showed that the 36-kDa MAP bound 2.2 calvasculin eq/mol of protein. Solid-phase binding assays indicated a preferential affinity of native calvasculin for 36-kDa MAP among the extracellular matrices in a Ca(2+)-dependent manner. These results suggest that calvasculin, intracellular Ca(2+)-binding protein, is released to the extracellular space and binds with 36-kDa MAP.

Animals↗

PubMed1992

Cytogenetic characteristics of childhood non-Hodgkin lymphoma.

Cytogenetic studies were performed successfully on 24 patients with non-Hodgkin lymphoma (NHL) who were younger than 15 years of age. Of these, 22 patients (92%) had abnormal clones. With respect to histologic findings, 3 (25%) of the 12 patients with lymphoblastic lymphoma had 14q11 translocations and 2 (17%) had t(9;17) (q34;q23). Four (80%) of the five patients with small non-cleaved cell lymphoma had t(8;14)(q24;q32). With respect to immunologic findings, four (44%) of the nine patients with T-cell lymphoma had abnormalities consisting of 14q11 and 7q36 translocations, in which the T-cell receptor genes resided. Three (33%) of the patients with T-cell lymphoma had t(9;17)(q34;q23). However, three (43%) of the seven patients with B-cell lymphoma had t(8;14) (q23;q32), and two (29%) of the patients with B-cell lymphoma had an extra i(11q) chromosome with a resultant 11q tetrasomy. Non-T-cell non-B-cell lymphomas, which occurred in 21% of all patients, showed various chromosomal abnormalities. This study demonstrated that, in childhood NHL, karyotype correlates closely with immunophenotype, clinical features, and histologic findings.

Adolescent↗

PubMed1992

CAP-50, a newly identified annexin, localizes in nuclei of cultured fibroblast 3Y1 cells.

A 50-kDa protein, which binds to the growth-regulated gene (2A9) product, calcyclin in a calcium-dependent manner, was purified from bovine lung. Partial amino acid sequencing of the protein revealed it to be the bovine equivalent of rabbit lung CAP-50 (calcyclin-associated protein, 50 kDa), which is a member of the annexin family and binds to calcyclin in a calcium-dependent manner. Specific polyclonal antibodies to bovine lung CAP-50 were prepared. Comparative studies between CAP-50 and synexin (annexin VII) on the immunoreactivity against anti-CAP-50 antibodies and the ability of binding to calcyclin revealed that CAP-50 was a distinct molecule from synexin. Using specific polyclonal antibodies to bovine lung CAP-50, tissue distribution and subcellular distribution of CAP-50 were investigated. In most rat tissues, except those in the central nervous systems and kidney, CAP-50 is expressed at a high or moderate level. Both studies by subcellular fractionation and by indirect immunofluorescence staining of the rat embryonic fibroblast cell line, 3Y1, revealed that CAP-50 mainly localized in nuclei. Moreover, between the cells at interphase and at mitotic phase, different distributions of CAP-50 were observed. That is, in the cells at interphase, CAP-50 seemed to localize throughout the nucleoplasm. On the other hand, in the cells during mitosis, CAP-50 was concentrated at the loop-like structure around the mitotic apparatus. CAP-50 was found in isolated 3Y1 nuclei lacking outer nuclear membranes, and approximately 50% of CAP-50 was extracted from the nuclei by chelating calcium. Thus, CAP-50, a unique annexin, localizes in nuclei.

Amino Acid Sequence↗

PubMed1992

A calcyclin-associated protein is a newly identified member of the Ca2+/phospholipid-binding proteins, annexin family.

A calcyclin-associated protein with an apparent molecular weight of 50,000 (CAP-50) was purified from rabbit lung. The procedure included ammonium sulfate precipitation, anion and cation ion-exchange, and calcyclin affinity chromatographies. Interestingly, partial amino acid sequences of lysyl-endpeptidase-digested fragments indicated that CAP-50 was a member of the Ca2+/phospholipid-binding proteins, the annexin family. The sequence of a proteolytic peptide with Staphylococcus aureus V8 protease on NH2-terminal region is not homologous with any other annexin family proteins. Phospholipid binding studies showed that CAP-50 bound to phosphatidylserine, phosphatidylethanolamine, phosphatidylinositol, and phosphatidic acid-containing vesicles, in a Ca(2+)-dependent manner. In the presence of Ca2+/calcyclin, CAP-50 formed a complex with calcyclin and bound to the PS-containing vesicles. The apparent Kd value of calcyclin for CAP-50 was calculated to be 1.61 x 10(-6) M. Zero-length cross-linking studies indicated that 1 mol of CAP-50 bound to an equimolar unit of calcyclin. CAP-50 inhibited the phospholipase A2 activity, dose-dependently (IC50 = 0.2 microM), however, calcyclin did not alter the inhibitory effect. With the 125I-calcyclin gel overlay method, calcyclin bound tightly to CAP-50 in a Ca(2+)-dependent manner after sodium dodecyl sulfate-polyacrylamide gel electrophoresis. These results suggest that rabbit lung CAP-50 is a newly identified member of the annexin family. Ca2+/calcyclin apparently regulates the function of CAP-50 on cytosolic face of the plasma membrane.

Amino Acid Sequence↗