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Biomedical subjects

T Satoh

Publications and source records attributed to T Satoh.

At least 613 records · Page 34Linked to original sources
PubMed1995

[Rapid detection and identification of mycobacteria by the PCR assay based on the co-amplification of the gene IS6110 and groEL].

In definite diagnosis of mycobacterial infection, prompt and adequate differential diagnosis leads to an appropriate treatment. We developed and evaluated a PCR assay based on co-amplification of the insertion sequence IS6110 and groEL gene that are species-specific for Mycobacterium tuberculosis complex and genus-specific, respectively. The detection limit of the assay system for cultured M. tuberculosis was 2 cells/ml, as compared with 200 cells/ml by culture onto Ogawa's medium. To assess the value of the assay in routine laboratory works, the results obtained by PCR were compared with those by standard microbiological methods for 758 specimens collected for the examinations of mycobacterial infection. The PCR system for detection of mycobacteria gave overall positive rate of 27.6% (209/758), as compared to 6.1% (46/758) by smear and 7.7% (58/758) by culture onto Ogawa's medium. Sensitivity and specificity were 97.8% and 97.3%, respectively, for the IS6110 and groEL gene for detection of M. tuberculosis complex; 91.7% and 80.3%, respectively, for only the groEL gene for detection of atypical mycobacteria. The PCR assay based on co-amplification of the IS6110 and groEL gene would be useful for diagnosis of mycobacterial infections, allowing not only more sensitive detection of mycobacteria but also rapid discrimination between M. tuberculosis complex and atypical mycobacteria. This assay would help to eliminate time-consuming confirmation, and to avoid both unnecessary treatment and hospitalization of the patient.

DNA, Bacterial↗
PubMed1995

[Effects of systemic lidocaine, mepivacaine and bupivacaine on passive avoidance learning in mice].

The effects of local anesthetics on learning were assessed in mice through one trial step-through passive avoidance performance. Lidocaine HCl (10, 20 or 40 mg.kg-1), mepivacaine HCl (15, 30 or 60 mg.kg-1) or bupivacaine HCl (2.5, 5 or 10 mg.kg-1) were injected subcutaneously 10 min before acquisition training. Lidocaine, but not mepivacaine and bupivacaine, reduced the latency in the retention trial conducted 24hr after the training in a dose-dependent manner. However, lidocaine did not alter the latency when it was given 10 min before the retention trial. These results suggest that lidocaine impairs acquisition, but not retention or retrieval phase in the memory process.

Anesthetics, Local↗
PubMed1995

[Primary lung cancer presenting as spontaneous pneumothorax].

Pneumothorax is a rare manifestation of lung cancer. The mechanism by which pneumothorax occurs in lung cancer is not clear, and differing views have been expressed. Among 180 adults who presented with spontaneous pneumothorax from 1980 to 1992, eight had lung cancer: seven had squamous cell carcinoma and one had adenocarcinoma. All were men between 50 and 81 years old (average age, 66 years). In all patients, the pneumothorax occurred on the same side as the carcinoma. Thoracotomy was done in four patients. The results obtained by surgery indicated that pneumothorax may be caused by: 1) direct invasion of tumor into the pleura (patient 1); 2) rupture into the pleural space of dilated alveoli that are distal to the site of stenotic bronchial cancer (patient 7); 3) rupture into the pleural space of alveoli that had become distended to compensate for atelectasis due to obstructive bronchial cancer (patient 6); and 4) unknown (patient 2). These results suggest that lung cancer should always be considered as a possible cause of spontaneous pneumothorax in older patients.

Adenocarcinoma↗
PubMed1995

[Establishment of a cisplatin-resistant new human endometrial adenocarcinoma cell line, Sawano cells].

A new human endometrial adenocarcinoma cell line, Sawano cells, was established from an endometrial adenocarcinoma from a 61-year-old woman and has been maintained in vitro for more than 2 years and 10 months. The cells were found to form a monolayer in a mosaic fashion and to tend to pile up. Population doubling time was 43.2 hours at the 10th generation. The modal chromosomal number of the cell fell in a diploid range. Histology of the tumor induced in athymic mice showed it to be a moderately differentiated adenocarcinoma which closely resembled the original human tumor. Estrogen and progesterone receptors were not demonstrated in the in vitro culture cells and in the tumors induced in nude mice, though they were positively demonstrated in the original tumor. The cells had intrinsic cisplatin-resistance (50% inhibition concentration:6.63 micrograms/ml) at 120 hours of contact. We believe this cell line with help us to investigate the biological mechanisms of CDDP resistance.

Adenocarcinoma↗
PubMed1995

Interindividual variation in carboxylesterase levels in human liver microsomes.

Microsomal carboxylesterase activities in 12 human livers were determined using 10 kinds of carboxylesterase substrates (p-nitrophenylacetate, p-nitrophenylpropionate, p-nitrophenylbutyrate, butanilicaine, isocarboxazid, palmitoyl-coenzyme-A, malathion, clofibrate, acetanilide, and phenacetin). There were large individual differences in the 12 humans based on experimental results in the past several years in our laboratory. We found that all human liver microsomes have RH1-immunoreactive carboxylesterase, and the carboxylesterase content in liver also showed large individual differences. The RH1-immunoreactive carboxylesterase concentration correlated well with those of p-nitrophenylesters, clofibrate, butanilicaine, and isocarboxazid, and anti-RH1 immunoglobulin G strongly inhibited human liver hydrolase activity. These findings indicate that one major carboxylesterase isozyme that is immunoreactive with anti-RH1 in human liver microsomes has catalytic activity on major carboxylesterase substrates, and thus hydrolase activity in human liver depends on the expression level of this carboxylesterase isozyme. These observations should be useful in understanding the action of carboxylesterases on drug metabolism in humans.

Adult↗
PubMed1995

[Establishment of a new human endometrial adenocarcinoma cell line, Watanabe cells, containing estrogen receptor].

A new human endometrial adenocarcinoma cell line, Watanabe cells, was established from the ascitic fluid of a relapsed endometrial adenocarcinoma obtained from a 58-year-old woman; this cell line has been maintained in vitro for more than 3 years and 8 months. The cells formed a monolayer in a mosaic fashion and tended to pile up and formed a hemicyst. The population boubling time was 60.0 hours at the 10th generation. The modal chromosomal number of the cells was in the diploid range. The histology of tumors induced by this cell line in athymic nude mice showed poorly differentiated adenocarcinoma, while the initial tumor was a well differentiated adenocarcinoma. Estrogen and progesterone receptors (ER, PR) were demonstrated in the original tumor, whereas ER but not PR were present in the tumors induced in nude mice. CA125, CA19-9 and other tumor markers were positive in culture media of this cell line. The cells showed intrinsic cisplatin-resistance (50% inhibition concentration: > 10 micrograms/ml) at 120 hours of exposure by MTT assay. We believe this cell line will be useful for investigating the mechanisms of progesterone therapy, the biological behaviors of the tumor markers and mechanisms of chemotherapeutic resistance in endometrial carcinoma.

Adenocarcinoma↗
PubMed1995

Rapid formation of multicellular spheroids composed of Propionibacterium acnes pretreated adult rat liver cells by rotary culture and their immunological properties.

An experimental acute liver injury model can be produced by the injection of bacterial lipopolysaccharide (LPS) into Propionibacterium acnes (P. acnes) pretreated rats. The massive liver cell necrosis is estimated by elevation of serum transaminase activities. In this study, we produced this necrosis in an in vitro model by using primary co-cultured rat liver cells. A novel method for the preparation of spheroids consisting of P. acnes pretreated parenchymal and nonparenchymal liver cells has been successfully developed quickly by the rotary culture system within 24 hr although it takes 7 days to form the spheroid using a collagen-conjugated thermo-responsive polymer such as a cell substratum. Clear elevations of transaminase activities, TNF-alpha and CINC-1/gro/KC leaked from these spheroids into the medium caused by the exposure of 10 microgram/ml LPS for 48 hr were observed. These results suggest that this rotary co-culture system of rat liver cells is a useful model as an alternative to animal tests for fulminant hepatitis.

Animals↗
PubMed1995

Abnormal hepatic copper accumulation of spheroid composed of liver cells from LEC rats in vitro.

The LEC rat is a mutant strain displaying hereditary hepatitis, and shows abnormal accumulation of copper (Cu) similar to that occurring in Wilson's disease. We prepared a multicellular spheroid composed of LEC rat liver cells to investigate the mechanism for abnormal accumulation of Cu. These multicellular spheroids were prepared by detaching the monolayer on the collagen-conjugated thermo-responsive polymer coated culture dish at a temperature below the critical solution temperature and culturing on the non-adhesive substratum. Long-term cultured spheroids of LEC rat liver cells as well as SD rat liver cells were attempted. Non-parenchymal cells obtained by collagenase perfusion from the LEC liver were fewer than those from the SD liver. Cells from the LEC rat, over 11 weeks of age, did not form a cell sheet; however, a mixture of parenchymal cells from LEC rats over aged 11 weeks and non-parenchymal cells from SD rats of any age yielded intact spheroids. We examined the toxicity, the accumulation and distribution of Cu in spheroids. The accumulation of Cu in LEC spheroids was higher than that in SD spheroids. Results suggest that spheroids consisting of LEC liver cells are useful as an alternative model to in vivo tests to investigate the mechanism for abnormal accumulation of Cu in liver.

Animals↗
PubMed1995

Characterization and transcriptional regulation of the modABCD genes for molybdenum transport in Escherichia coli.

The mod genes coding for molybdenum transport system were isolated from Escherichia coli by means of complementation of the tor mutation that causes no synthesis of some molybdenum-containing enzymes. The nucleotide sequence of 3048-base pair showed four open reading frames including the previously reported modC gene. The genes were named modA, modB, modC, and modD. Promoter analysis by lacZ assay and primer extension showed the genes modA and modB individually have their own promoters. No transcriptional regulation of the two genes were observed in the presence of molybdate, nitrate, and oxygen in E. coli strain DH5 alpha.

Bacterial Proteins↗
PubMed1994

Tetrafibricin has a high selectivity for GPIIb/IIIa: comparison of the effects of tetrafibricin and RGDS on GPIIb/IIIa and the vitronectin receptor.

The specificity of tetrafibricin was examined by comparing its activities on GPIIb/IIIa and on the vitronectin receptor (alpha v beta 3) with those of Arg-Gly-Asp-Ser (RGDS) on the same receptors. Tetrafibricin, which inhibited fibrinogen-GPIIb/IIIa binding 10 times more potently than RGDS, was three orders of magnitude less potent compared to RGDS on the inhibition of fibrinogen binding to alpha v beta 3. Furthermore, tetrafibricin potently inhibited platelet adhesion to both fibrinogen and von Willebrand factor. Whereas, there was no significant inhibition observed in the GPIIb/IIIa-independent cellular adhesions. These results suggest that tetrafibricin is highly selective for GPIIb/IIIa.

Amino Acid Sequence↗
PubMed1994

Histamine as an activator of cell growth and extracellular matrix reconstruction for human vascular smooth muscle cells.

Atherosclerosis is characterised by unusual growth of vascular smooth muscle cells (VSMCs) in the intima. We examined the effects of histamine on human VSMCs and the VSMC-derived cell line, ISS10. Histamine enhanced phosphoinositide hydrolysis, increased cytoplasmic Ca2+ level and stimulated the transcription of c-fos protooncogene, which resulted in DNA synthesis and the enhancement of proMMP-1 expression. These results indicate that histamine may play some roles in the pathological process of atherosclerosis and raise the possibility that mast cells migrating into the atherosclerotic foci are involved in the process of atherosclerogenesis.

Arteriosclerosis↗
PubMed1994

Immunohistochemistry with an antibody to human liver carboxylesterase in human brain tissues.

Human liver carboxylesterase (CE) is an enzyme capable of metabolizing drugs, and may also function as a regulator of lipid metabolism. We examined one isoform of CE by immunohistochemistry in the brains of neurologically normal, Alzheimer disease (AD), amyotrophic lateral sclerosis (ALS) and cerebral infarction cases. In all but the infarcted brains, the anti-CE antibody stained only capillary endothelial cells in the brain and spinal cord tissues. In infarct brain areas, intense immunoreactivity of the macrophages was seen. In contrast, the macrophages in the ALS lateral columns and the reactive microglia located in the center of classical senile plaques in AD, as well as other reactive microglial cells in the grey matter, showed no immunoreactivity. In the central nervous system, CE may function as a protective factor against foreign chemicals in capillary endothelial cells, and the antibody to CE may serve as a marker for invading macrophages from the systemic circulation.

Adult↗
PubMed1994

Roles of heme iron-coordinating histidine residues of human hemopexin expressed in baculovirus-infected insect cells.

Hemopexin (Hx), the major heme-binding plasma glycoprotein, scavenges circulating heme and performs an antioxidant function. In the present study, human Hx was expressed in a baculovirus system and its presumed essential His residues were mutated to Thr as a means of investigating their participation in heme binding. The recombinant Hx proteins were purified by sequential chromatography on Con A-agarose and SP-Sepharose. The purified recombinant wild-type Hx retained its heme binding. The binding constant for heme was considerably reduced, however, suggesting that glycosylation contributes critically to the heme binding property of Hx. Mutation either at His-127 or at His-56 plus His-127, but not at His-56 per se, reduced the affinity for heme by an order of magnitude relative to wild-type Hx. It is concluded that His-127 contributes to the high affinity for heme. We recorded proton NMR spectra to investigate the possibility that the degree of high-spin content is increased by deletion of an axial His-iron coordination. 1H NMR data indicate that each of the single-mutant heme-Hx complexes is predominantly low-spin, perhaps owing to coordination of the heme iron by the Thr side-chain oxygen or water oxygen coordinating to the iron.

Animals↗
PubMed1994

Tetrafibricin, a novel non-peptide fibrinogen receptor antagonist, induces conformational changes in glycoprotein IIb/IIIa.

Arg-Gly-Asp (RGD) is an amino acid sequence in fibrinogen recognized by platelet glycoprotein (GP) IIb/IIIa. Recently, it was found that RGD peptide binding to GPIIb/IIIa leads to conformational changes in the complex that are associated with the acquisition of high-affinity fibrinogen-binding function. In this study, we found that tetrafibricin, a novel non-peptidic GPIIb/IIIa antagonist, induced similar conformational changes in GPIIb/IIIa as did RGD peptides. Tetrafibricin increased the binding of purified inactive GPIIb/IIIa to immobilized pl-80, a monoclonal antibody that preferentially recognizes ligand-occupied GPIIb/IIIa. Exposure of the pl-80 epitope by tetrafibricin was also observed on resting human platelets by flow cytometry. On intact platelets, the conformational changes transformed GPIIb/IIIa into a high-affinity receptor for fibrinogen and triggered subsequent platelet aggregation. Tetrafibricin is the first non-peptidic GPIIb/IIIa antagonist reported that has the capacity to induce conformational changes in GPIIb/IIIa.

Amino Acid Sequence↗
PubMed1994

Genotypical classification of neutrophil Fc gamma receptor III by polymerase chain reaction-single-strand conformation polymorphism.

We classified the genotype of neutrophil Fc gamma receptor III (FcRIII) (CD16) with a new method. Genomic DNA from mononuclear cells of 39 unrelated healthy donors (13 NA1/NA1, 13 NA2/NA2, and 13 NA1/NA2 typed serologically) were subjected to polymerase chain reaction (PCR) to amplify the polymorphic third exon of the FcRIII genes. The PCR products were heat denatured, electrophoresed, and visualized by silver staining. Allelic differences were detected by distinctive electrophoretic patterns of each single strand, depending on their sequence specific conformations (single-strand conformation polymorphism [SSCP]). The genotypes of neutrophil FcRIII determined by this method were consistent with the phenotypes of NA antigens determined by serologic examinations. These results indicate that the PCR-SSCP system is a very useful tool for genotyping of the neutrophil FcRIII.

Base Sequence↗
PubMed1994

Structural factors of antimycin A molecule required for inhibitory action.

A series of antimycin A analogues was synthesized by modifying the salicylic acid moiety, whereas the portion of the molecule corresponding to the natural dilactone-ring moiety was fixed as di-n-octyl L-glutamate. To probe the structure of the antimycin A binding site, the structural factors of the salicylic acid moiety required for inhibitory action were examined by means of structure-activity studies with intact rat-liver mitochondria and the cytochrome bc1 complex isolated from bovine heart mitochondria. As suggested earlier (Rieske, J.S. (1976) Biochim. Biophys. Acta 456, 195-247), the phenolic OH was very important for inhibition. For the derivatives which do not possess a formylamino group in the 3-position (ortho to the phenolic OH), the inhibitory activity tended to increase as the electron-withdrawing property of the substituent increased, i.e., as the acidity of the phenolic OH group increased. This indicates that the acidity of the phenolic OH is an important factor governing inhibition. While the electron-withdrawing property of the formylamino group itself is rather poor, 3-formylamino derivatives elicited potent activity. The conformation of the 3-formylamino group was also found to be a very important factor in establishing inhibitory activity. In addition, the bulkier the moiety corresponding to the 3-formylamino group, the lower the activity. These results demonstrate that the presence of the 3-formylamino group, and its proper conformation, are needed for a close fitting of antimycin A to its binding domain. Although the inhibitors that lack a 3-formylamino group retained fairly potent activity, their effects on the reduction of cytochromes b and c1 were somewhat different from those of natural antimycin A, indicating that the 3-formylamino group is essential for inhibitor binding to the cytochrome bc1 complex in the same manner as natural antimycin A. It is concluded that both the 3-formylamino group and the phenolic OH of antimycin A make important contributions to specific interactions with the amino acid residues of the cytochrome b.

Animals↗
PubMed1994

Activation by human chorionic gonadotropin of ovarian carbonyl reductase in mature rats exposed in vivo to estrogens.

We investigated the effects of exogenous estrogens and human chorionic gonadotropin (hCG) on the activity, content, and immunohistochemical localization of ovarian carbonyl reductase (CR) in mature cycling rats. Estrogens, estradiol, hexestrol (HEX) and diethylstilbestrol (DES) were given s.c. to rats daily for 3 days from the first day of diestrus, and hCG was given s.c. at 3:00 p.m. on the day of expected proestrus. The ovaries were isolated on the day of expected estrus. Ovarian CR activity was measured by using two substrates that reflect the activity of the enzyme in rats, and the enzyme content was determined by western blot analysis. Ovarian CR activity and content were decreased by estrogens as well as by inhibition of ovulation; hCG restored both the activity and the content decreased by estrogens to levels produced by hCG alone. Nevertheless, the number of ova in the oviduct when ovulation was decreased or blocked by estrogens was not restored completely by hCG treatment. Faint immunostaining in the interstitial gland cells of HEX-treated rat ovaries was observed. These results suggest that (i) although hCG activates ovarian CR in estrogen-treated rats, this increase in both enzyme activity and content may not be an obligatory event in the ovulatory process, and (ii) exogenous estrogens may predominantly influence the ovarian CR in the interstitial gland cells in mature rats by inhibiting luteinizing hormone release from the pituitary.

Alcohol Oxidoreductases↗