Biomedical subjects

K Kishi

Publications and source records attributed to K Kishi.

At least 145 records · Page 8Linked to original sources

PubMed1999

Colocalization of leptin receptor (OB-R) mRNA and placental lactogen-II in rat trophoblast cells: gestational profile of OB-R mRNA expression in placentae.

The present study was designed to clarify the cellular localization and expression of leptin receptor(s) [OB-R(s)] mRNA including its splice variants and their correlation with the cells which secrete placental hormone, placental lactogen-II (PL-II), in rat placentae. By in situ hybridization analysis, hybridization signals for OB-Rb and the common extracellular domain of OB-R were first detectable in some cells of the labyrinth zone of the placentae on day 14 of pregnancy and then a lot of cells dispersed in the entire area of the labyrinth zone expressed OB-Rb during the latter half of pregnancy. However, no expression was observed in the decidua and the junctional zone of the placentae during pregnancy. Double staining study revealed that signals for OB-R expressing trophoblast cells showed PL-II immunoreactivity in the labyrinth zone of the placentae. In Northern blot analysis, two bands (2.8 kb and 5.1 kb) of OB-R mRNA expression were observed in the placentae from day 17 to 21 of pregnancy and the expression of both increased markedly up to day 21 of pregnancy. RT-PCR analysis revealed that OB-Rb, OB-Ra, and OB-Re are expressed in the placentae on days 19 and 21 of pregnancy. These results suggest that the OB-R may have a physiological significance in the placental function during the latter half of pregnancy.

Alternative Splicing↗

PubMed1999

Structural requirements of a human deoxyribonuclease II for the development of the active enzyme form, revealed by site-directed mutagenesis.

Using site-directed mutagenesis, we eliminated three potential N-glycosylation sites (N86, N212, and N266) of human deoxyribonuclease II (DNase II), conserved in mammalian enzymes, and a proteolytic processing site (Q46-R47), forming a propeptide subunit of the enzyme. We expressed a series of these mutant DNase II constructs in COS-7 and Hep G2 cells. Liberation of each glycosylation site at N86 and N266 and the cleavage site interfered dramatically with expression of the intracellular and secreted DNase II activities, irrespective of cell line transfected. A chimeric mutant in which the signal peptide of the DNase II was replaced with that of human DNase I had no intracellular or secreted enzyme activity. Therefore, a simultaneous attachment of a carbohydrate moiety to N86 and N266, cleavage of the propeptide from the single DNase II precursor, and the inherent signal peptide might be required for subcellular sorting and proteolytic maturation of the enzyme.

Amino Acid Substitution↗

PubMed1999

Lack of correlation between mitotic arrest or apoptosis and antitumor effect of docetaxel.

PURPOSE: To determine, as we did for paclit-axel, whether mitotic arrest and apoptosis induced in murine tumors in vivo by docetaxel correlate with the drug's antitumor effect and whether the antitumor efficacy of docetaxel depends on p53 mutational status of tumors. METHODS: C3Hf/Kam mice were implanted with one of the following 15 syngeneic tumors: seven adenocarcinomas (MCa-4, MCa-29, MCa-35, MCa-K, OCa-I, ACa-SG, and HCa-I), two squamous cell carcinomas (SCC-IV and SCC-VII), five sarcomas (FSa, FSa-II, Sa-NH, NFSa, and Sa-4020) and one lymphoma (Ly-TH). When the tumors had grown to 8 mm in diameter, the mice were treated with 31.3 mg/kg docetaxel i.v. Tumor growth delay was the endpoint of docetaxel's antitumor effect. In separate groups of mice, mitotic arrest and apoptosis were determined micromorphometrically 1 to 72 h after docetaxel treatment. Tumors were assayed for their p53 status by sequence analysis of RNA prepared from freshly excised tumors. RESULTS: Docetaxel caused statistically significant growth delay in six of seven adenocarcinomas, three of five sarcomas, and the lymphoma, but not in either of the squamous cell carcinomas. The drug induced mitotic arrest in all tumor types, but to various degrees ranging from 6.4+/-0.4% to 25.1+/-0.1%. In contrast, docetaxel induced appreciable apoptosis in only 5 of 15 tumors, with 10.3+/-1.6% being the highest apoptotic value. Neither mitotic arrest nor apoptosis were significantly correlated with tumor growth delay. However, tumors that responded to docetaxel by significant tumor growth delay histologically displayed massive cell destruction by cell lysis, and four of these tumors also showed marked infiltration with mononuclear lymphoid cells. Of the 15 tumors only 3 had mutant p53. CONCLUSIONS: Docetaxel exhibited a strong antitumor effect in two-thirds of murine tumors, and on a milligram per kilogram basis was more effective than paclitaxel against the same tumors. The drug was a potent inducer of mitotic arrest but a weak inducer of apoptosis, neither of which correlated with its antitumor effect. Tumor cell lysis appeared to be a major mode of tumor cell destruction and can be regarded as the main mechanism underlying antitumor efficacy of docetaxel. In contrast, paclitaxel's antitumor efficacy is related to its ability to induce apoptosis. At the molecular level, there was no dependency of antitumor efficacy of docetaxel on p53 mutational status of tumors.

Animals↗

PubMed1999

Expression of eosinophil peroxidase in the immature basophil cell line KU812-F.

Although peroxidase activity in basophils can be detected by optical and ultrastructural cytochemistry, its characteristics remain to be determined. We have demonstrated the characteristics of peroxidase activity induced in the immature basophil cell line, KU812-F. Ultrastructurally, peroxidase activity was detected in granules as well as in the perinuclear space and endoplasmic reticulum. Immunocytochemistry revealed that KU812-F cells were stained by anti-eosinophil peroxidase antibodies, and eosinophil peroxidase mRNA, not myeloperoxidase, was detected in the cells using Northern hybridization and reverse transcription-polymerase chain reaction. Eosinophil peroxidase can be one of the molecules shared with eosinophils and basophils. The biological function of eosinophil peroxidase detected in basophils remains uncertain.

Basophils↗

PubMed1999

Regional excitatory and inhibitory amino acid concentrations in Noda epileptic rat (NER) brain.

We measured regional concentrations of excitatory and inhibitory amino acids in Noda epileptic rat (NER) brains to investigate the mechanisms responsible for spontaneous generalized seizures. Compared with Fisher 344 (F344) rats and F1 hybrid (female NER x male F344 rat) rats, NERs had significantly higher concentrations of glycine in the cerebellum. NERs and F1 hybrid rats had significantly lower concentrations of taurine in the cerebellum than did F344 rats. Although our findings do not explain sufficiently the mechanisms directly responsible for spontaneous seizures, they suggest that the cerebellum of NER may be in an excited state to dampen seizures, while the cerebellum of F1 hybrid rats may also be slightly excited to inhibit milder forms of seizures. Further studies, including microdialysis and receptor binding assays, will be required to elucidate these mechanisms.

Amino Acids↗

PubMed1999

Enhancement of sucrase-isomaltase gene expression induced by luminally administered fructose in rat jejunum.

We have previously shown that feeding a diet containing sucrose to rats causes an elevation of sucrase-isomaltase (SI) mRNA level in the jejunum. In this study, we examined whether the SI mRNA level could be directly elevated by administration of one of the constituting monosaccharides (i.e., glucose and/or fructose). Gastric intubation of a sucrose solution caused increases in both sucrase activity and SI mRNA level in the jejunum. Intrajejunal intubation of fructose, but not glucose, led to an elevation of sucrase activity and SI mRNA level. To examine whether fructose directly affects the gene expression of SI at the segment where the absorption of this sugar takes place or the sugar-induced increase in the gene expression of SI is secondary to any possible changes in the level(s) of certain hormonal factor(s) in the blood stream, a solution containing either fructose or glucose was simultaneously perfused into two consecutive cannulated and irrigated loops of jejunum that were not isolated from blood circulation. Compared with the loop perfused with glucose, the loop perfused with fructose exhibited significantly greater sucrase activity and SI mRNA level as well as the elevated GLUT5 mRNA level. These results suggest that fructose is capable of directly increasing the gene expression of SI and GLUT5 in the confined segment where fructose is absorbed.

Journal Article↗

PubMed1999

Simultaneous typing of the STR loci, vWF and HumTPO, using discontinuous polyacrylamide gel electrophoresis.

Analyses of short tandem repeat (STR) loci are very useful for improving the accuracy of paternity determination. Combined use of several STRs makes this test even more accurate. We have devised a simple but effective method which consists of the co-amplification of two STR loci (vWF and HumTPO) in a single test tube, separation of the PCR products using discontinuous polyacrylamide gel electrophoresis, and detection using sensitive silver staining. An appropriate combination of PCR primer pairs gave a high resolution and good separation of the two STR bands in the same lane on the same gel. Many combinations of STR loci have potential usefulness in paternity and individualization testing or population genetic studies in forensic practice.

Journal Article↗

PubMed1999

Molecular, biochemical and immunological studies of hen pancreatic deoxyribonuclease I.

Deoxyribonuclease I (DNase I) was purified from the hen pancreas to electrophoretic homogeneity using six-step column chromatography. The purified enzyme showed a molecular mass of about 33 kDa and maximum activity at pH 7.0. It required divalent cations, Mg2+ and Ca2+, for its activity and was inhibited by EDTA, EGTA and an antibody specific to the purified enzyme but not by G-actin. A 1066-bp cDNA encoding hen DNase I was constructed from the total RNA of a hen pancreas using a combination of the reverse transcriptase-polymerase chain reaction and rapid amplification of cDNA ends methods, followed by sequencing. The cDNA was expressed in Escherichia coli, and the recombinant polypeptide exhibited significant enzyme activity. The mature hen DNase I protein was found to consist of 262 amino acids. In human and bovine DNase I four amino acid residues, Glu-13, Tyr-65, Val-67 and Ala-114 are involved in actin binding, whereas in the hen DNase I these positions were occupied by Asp, Phe, Ser and Phe, respectively. A survey of the DNase I distribution in 15 hen tissues showed that the pancreas had the highest levels of both DNase I enzyme activity and DNase I gene expression. The results of our phylogenetic and immunological analyses indicate that the hen DNase I is not closely related to the mammalian enzymes. This is the first report in which has been described the results of molecular, biochemical and immunological analyses on hen DNase I.

Amino Acid Sequence↗

PubMed1999

Immunological background in children with persistent diarrhea in Ghana.

BACKGROUND: Persistent diarrheal diseases have become one of the most serious medical problems in developing countries, but few studies have been conducted to determine the risk factors. In the present study, we investigated the nutritional and immunological background in children with persistent diarrhea in comparison with those with acute diarrhea. METHODS: Children with diarrhea who were brought to the Oral Rehydration Salt Clinic of Princess Marie Louise Children's Hospital in Accra were evaluated from an immunological and nutritional aspect. In the follow-up visit, the cases whose diarrhea stopped within 2 weeks after onset were classified into the acute diarrhea group; those with diarrhea lasting more than 2 weeks were classed in the persistent group. Nutritional and immunological data at the initial visit were compared between these two groups. RESULTS: In general, the diarrhea cases had a tendency to undernutrition and impaired cellular immunity compared with healthy control. Persistent cases had lower values for longer half-life, rapid turn-over proteins. Persistent cases had a higher percentage of CD8+ cells and lower CD4/CD8 ratio. CD25 expression in CD4+ cells stimulated by anti-CD3 antibody was lower in the persistent diarrhea group. CONCLUSION: These results appear to support the hypothesis that more severe nutritional status and impairment of cellular immunity is related to the persistence of diarrhea.

CD4-CD8 Ratio↗

PubMed1999

Differential responses of collagen and glycosaminoglycan syntheses and cell proliferation to exogenous transforming growth factor beta 1 in the developing mouse skin fibroblasts in culture.

Skin fibroblast cultures were established from mouse foetuses at days 14, 15, 16 and 18 of gestation and from newborn mice. Modulations of mitotic and biosynthetic phenotypes of the fibroblasts by transforming growth factor beta1 (TGFbeta1) were studied. Treatment of the fibroblasts with TGFbeta1 at doses of 1 and 10 ng/ml for 48 h resulted in significant stimulation of cell proliferation in the 15-, 16- and 18-day foetal fibroblasts and a slight stimulation in the 14-day foetal fibroblasts. Treatment with TGFbeta1 resulted in stimulation of collagen synthesis approximately 2-fold in the 18-day foetal and newborn fibroblasts, but failed to stimulate it in the 14-, 15- and 16-day foetal fibroblasts. TGFbeta1 stimulated glycosaminoglycan (GAG) synthesis throughout all developmental stages approximately 1.8-2.6 fold. Histological study demonstrated that skin wounds made at day 16 of gestation were replaced with normal-appearing dermis, but at day 18 the wounds left dermal fibrosis and lack of hair follicles. These results indicate that the modulations of fibroblast phenotypes (proliferation and syntheses of collagen and GAG) in response to TGFbeta1 occur at different stages of gestation. Ontogenic transitions of skin wound healing and collagen synthetic phenotype with TGFbeta1 treatment in cultured fibroblasts occurred between days 16 and 18 of gestation, suggesting that the unresponsiveness of collagen synthesis to exogenous TGFbeta1 in cell culture may be related to the phenomenon of scarless wounds in the foetus.

Animals↗

PubMed1999

Vitamin A prevents the decline in immunoglobulin A and Th2 cytokine levels in small intestinal mucosa of protein-malnourished mice.

We examined whether vitamin A improved mucosal immune depression in mice with wasting protein deficiency. In male C3H/HeN mice fed a semi-purified 1% protein diet for 2 wk, plasma retinol and immunoglobulin A (IgA) concentrations in the small intestinal mucosa were 50 and 55%, respectively, of those in mice fed a semi-purified 20% protein diet, (P < 0.05). Daily supplementation of 0.3 mg of retinyl acetate to protein-deficient mice for 2 wk increased the plasma retinol level to the value in the protein-sufficient mice. However, 1 mg/d of retinyl acetate was required to prevent the decline of the IgA level caused by the protein deficiency. Mice fed the low-protein diet had lower concentrations of IL-4 and IL-5 in the small intestinal mucosa and fewer IL-4- and IL-5-containing cells in the lamina propria (P < 0. 05). Retinyl acetate (1 mg) significantly restored the IL-5 level and the number of IL-4- and IL-5-containing cells. After immunization with 20 microg of cholera toxin (CT), the intestinal mucosa of protein-deficient mice contained significantly less CT-specific IgA than control mice. Treatment with 1 mg of retinyl acetate prevented the decline of anti-CT IgA level in the protein-deficient mice, improving their survival rate after an exposure to 0.1 mg of CT. These results suggest that large oral supplements of vitamin A may preserve mucosal IgA level during protein malnutrition, possibly by stimulating Th2 cytokine production and thereby, inducing resistance against infection.

Animals↗

PubMed1999

Sucrase-isomaltase and hexose transporter gene expressions are coordinately enhanced by dietary fructose in rat jejunum.

We previously demonstrated that the levels of mRNAs of both sucrase-isomaltase (SI) and sodium/D-glucose transporter (SGLT1) are modulated by dietary sucrose in the rat jejunum. In the present study, we investigated whether the transcription of the gene coding SI is regulated by certain types of monosaccharides. Force-feeding a fructose and sucrose diet, (40% energy as fructose or sucrose) gave rise to parallel increases in the transcripts of SI and intestinal hexose transporters (SGLT1, GLUT5, and GLUT2) within 12 h. Force-feeding a glycerol-containing diet also caused an enhancement of SI, SGLT1, and GLUT2 mRNA levels. However, feeding the diet containing glucose or alpha-methylglucoside generally did not increase the transcript levels of SI or the intestinal hexose transporters. Nuclear run-on assays revealed that fructose as well as sucrose increased the transcription of both SI and GLUT5 genes and that the transcription rates of these genes were unaffected by glucose. These results suggest that fructose (or a metabolite) is capable of increasing the mRNA levels of SI and hexose transporters in the small intestine and that transcriptional regulation might play a pivotal role in the carbohydrate-induced coordinate enhancement of SI and fructose transporter gene expression

Animals↗

PubMed1999

Involvement of SHP-1, a phosphotyrosine phosphatase, during myeloid cell differentiation in acute promyelocytic leukemia cell lines.

We investigated the modulation of the expression and phosphatase activity of SHP-1 during granulocytic differentiation of human myeloid leukemia cell line, HL60 and t(15;17) positive APL cell line, HT93, in response to all-trans retinoic acid (ATRA) or dimethylsulfoxide (DMSO). ATRA induced differentiation in both cell lines which was associated with marked growth inhibition and S-phase reduction. On the other hand, DMSO induced it only in HL60 without obvious growth inhibition and S-phase reduction. The expression and phosphatase activity of SHP-1 were upregulated only when the 2 cell lines were differentiated to granulocytes. Furthermore, the changes were not dependent on the inducers or the growth inhibition. These findings suggest that SHP-1 is involved in common myeloid differentiation, and that upregulation of SHP-1 is not always related to myeloid cell growth.

Cell Cycle↗

PubMed1999

Clindamycin suppresses endotoxin released by ceftazidime-treated Escherichia coli O55:B5 and subsequent production of tumor necrosis factor alpha and interleukin-1 beta.

Treatment of septicemia caused by Escherichia coli with ceftazidime (CAZ) may be associated with the development of septic shock due to the release of bacterial lipopolysaccharide. We examined the suppressive effect of clindamycin (CLDM) on CAZ-induced release of endotoxin by cultured E. coli and the subsequent production of inflammatory cytokines (tumor necrosis factor alpha [TNF-alpha] and interleukin-1 beta [IL-1 beta]). E. coli ATCC 12014 was incubated in inactivated horse serum with or without CLDM for 1, 4, or 18 h, followed by the addition of CAZ and collection of the culture supernatant at 0, 1, and 2 h. The concentration of endotoxin in each sample was measured by a chromogenic Limulus test. Another portion of the culture supernatant was added to THP-1 cell culture and incubated for 4 h, and the concentrations of TNF-alpha and IL-1 beta in the supernatant were measured by an enzyme-linked immunosorbent assay. In the control group (no CLDM), CAZ administration resulted in significant increases in endotoxin, TNF-alpha, and IL-1 beta concentrations. Pretreatment of E. coli with CLDM for 4 or 18 h before the addition of CAZ significantly suppressed the concentrations of endotoxin, TNF-alpha, and IL-1 beta in a time-dependent manner. In addition, CAZ treatment transformed E. coli from rodshaped bacteria to filament-like structures, as determined by electron microscopy, while pretreatment with CLDM prevented these morphological changes. Our in vitro studies showed that CAZ-induced release of large quantities of endotoxin by E. coli could be suppressed by prior administration of CLDM.

Anti-Bacterial Agents↗

PubMed1999

T1 and T2 lip cancer: a superselective method of facial arterial infusion therapy--preliminary experience.

PURPOSE: To formulate and evaluate a facial arterial infusion chemotherapy for squamous cell lip carcinoma. MATERIALS AND METHODS: The study included six patients (age range, 46-84 years) with squamous cell carcinoma of the lower lip. There were two T1 tumors, three T2 tumors, and one T1-compatible postoperative recurrent tumor. A 4-F, double-lumen balloon catheter was inserted into the external carotid artery through the superficial temporal artery and placed for selective infusion into the tumor-feeding facial artery. Patients received a combination of mitomycin C (4.4 mg/m2 per body surface area) on day 1 and 3.2 mg/m2 of peplomycin sulfate on days 1-7 (22.4 mg/m2 per week), or, when peplomycin sulfate was contraindicated, 16 mg/m2 of cisplatin only on days 1-5 (80 mg/m2 per week). Two to three cycles of chemotherapy were given until tumor disappearance was histologically confirmed. RESULTS: Complete tumor disappearance was achieved in all cases. One patient had a self-limiting asthma attack during peplomycin sulfate treatment, and another had transient partial hair loss. No disfigurement, recurrence, or late complications were observed at a mean follow-up of 5.0 years (range, 2.3-11.2 years). CONCLUSION: The described facial arterial infusion chemotherapy appears to be a safe and curative treatment for T1 and T2 squamous cell lip carcinomas.

Aged↗

PubMed1999

Xenopus laevis pancreatic DNase I: purification and immunological characterization.

Deoxyribonuclease I (DNase I) was purified from Xenopus laevis pancreas to apparent electrophoretic homogeneity using a series of column chromatographies. The purified enzyme showed a molecular mass of about 36 kDa and maximum activity at pH 7.0-8.0, required divalent cations, Ca2+ and Mg2+, for its activity, and was inhibited by EDTA, EGTA and an antibody specific to the enzyme, but not by G-actin. The N-terminal amino acid sequence of the enzyme up to the 37th residue shared 38-44% homology with that of mammalian DNases I derived from bovine, ovine, porcine, rat, mouse, rabbit and human. A systematic survey of DNase I activity distribution in 20 different kinds of frog tissues showed that the pancreas and rectum produced higher amounts than other tissues. This is the first report concerning the purification and chemical and immunological characterization of frog pancreatic DNase I.

Amino Acid Sequence↗

PubMed1999

Bronchiolitis in Kartagener's syndrome.

The association of diffuse bronchiolitis in patients with Kartagener's syndrome (KS) has not been reported previously. The aim of this study was to present the morphological characteristics of bronchiolitis in patients with KS. Eight patients (four males, four females; mean age 37.9+/-18.7 yrs), clinically diagnosed as KS with the classical triad of chronic pansinusitis, bronchiectasis and situs in versus with dextrocardia, were evaluated. Routine chest radiography showed bronchiectasis and dextrocardia in all patients. Chest computed tomography (CT) showed diffuse centrilobular small nodules up to 2 mm in diameter throughout both lungs in six out of eight patients. Pulmonary function tests revealed marked obstructive impairment in all patients (forced expiratory volume in one second 57.0+/-11.3%, residual volume/total lung capacity 45.+/-12.7%, maximum midexpiratory flow 0.92+/-0.72 L x s(-1), forced vital capacity 74.1+/-12.2% (all mean +/- SD)). The examination of cilial movement of the bronchus revealed immotility in all of the five patients examined. The ultrastructure showed ciliary dynein arm defects in all patients. Histopathological examination of lung specimens obtained at autopsy or by video-assisted thoracoscopic surgery showed obliterative thickening of the walls of the membranous bronchioli with infiltration of lymphocytes, plasma cells and neutrophils, but most of the distal respiratory bronchioli were spared and alveolar spaces were overinflated. Pathologically, the diffuse centrilobular small nodules on the chest CT mainly corresponded to membranous bronchiolitis. This is the first report demonstrating that the association of diffuse bronchiolitis might be one of the characteristic features of the lung in Kartagener's syndrome.

Adolescent↗

PubMed1999

Successful treatment of refractory bronchorrhea by inhaled indomethacin in two patients with bronchioloalveolar carcinoma.

Bronchorrhea in patients with bronchioloalveolar carcinoma is not uncommon. However, to our knowledge, an effective treatment for bronchorrhea in these patients has not been established. Recently, we have confirmed the efficacy of inhaled indomethacin in severe refractory bronchorrhea in comparison to that of other medications in two patients with bronchioloalveolar carcinoma. Despite the administration of a macrolide and corticosteroid, sputum volume increased to 700 mL/d in case 1 and to 200 mL/d in case 2 and hypoxemia and dyspnea deteriorated. Within a few days after the initiation of treatment with inhaled nebulized indomethacin (75 mg/d), sputum volume started to decrease and was controlled to < 100 mL/d, associated with alleviation of dyspnea and hypoxemia. To our knowledge, this is the first report of successfully treated refractory bronchorrhea associated with bronchioloalveolar carcinoma by inhaled indomethacin, resulting in markedly reduced sputum volume, improved quality of life, and prolonged survival.

Adenocarcinoma, Bronchiolo-Alveolar↗