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Biomedical subjects

H Sakamoto

Publications and source records attributed to H Sakamoto.

At least 613 records · Page 34Linked to original sources
PubMed1992

[Stimulatory effects of follicular stimulating hormone on the proliferation of ovarian cancer cell line in vitro and in vivo].

The present study was designed to determine the effects of follicular stimulating hormone (FSH) on the proliferation of the human ovarian cancer cell line (HRA line) in vitro and in vivo. The results showed: 1) The number of cells and 3H-thymidine uptake significantly increased after FSH treatment, but were suppressed by Buserelin (number of cells: 2.5 +/- 0.4 [con] vs 13.8 +/- 1.7 [FSH] vs 3.0 +/- 0.2 [FSH+GnRHa] x 10(4)/ml, uptake: 1,272.0 +/- 51.5 [con] vs 4,183.4 +/- 114.1 [FSH] vs 885.0 +/- 177.0 [FSH+GnRHa]cpm/10(5) variable cell mean +/- SD, p less than 0.05). 2) FSH increased the proportion of the cells in the S phase but decreased the cells in G0/G1 phase (S: 42.1 +/- 0.72 [con] vs 61.7 +/- 0.5 [FSH], G0/G1: 53.8 +/- 0.4 [con] vs 35.5 +/- 0.6 [FSH]% mean +/- SD, p less than 0.01, t-test). 3) Cyclic adenosine monophosphate (cAMP) production by HRA cells was significantly increased by cholera toxin (CTX), but not by FSH (1.29 +/- 0.72 [con] vs 2.05 +/- 0.21 [FSH] vs 16.2 +/- 2.28 [CTX]nM mean +/- SD p less than 0.001), suggesting that FSH has no effects on the adenylate cyclase system in the cell line. 4) FSH and GnRHa receptors were identified in HRA cells, and the number of the receptors was significantly decreased by Buserelin treatment (426.0 +/- 6.8 vs 98.6 +/- 12.3 sites/cell mean +/- SD, p less than 0.05, t-test).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

[Chromosome abnormalities in hypospadias? An analysis of 131 patients].

We performed chromosome studies in 131 patients presenting with hypospadias, with the aim of detecting any causal connections between chromosomal abnormalities and the induction of hypospadias. Autosomal abnormalities were revealed in 6 and sex chromosomal abnormalities in 10 patients. Although a significant causal relationship between the occurrence of hypospadias and chromosomal abnormalities was seen in this study in only two cases of mixed gonadal dysgenesis (45,X/46,XY and streak gonad), the high incidence of chromosomal abnormalities observed (12.2%) seems noteworthy compared with the incidence of only 0.61% in the normal male population.

Adolescent↗
PubMed1992

Human hst-2 (FGF-6) oncogene: cDNA cloning and characterization.

The hst-2 gene was previously identified by its close homology to the hst-1 gene. Cosmid clones containing the hst-2 gene were cloned from a normal human genomic library. Focus-forming activity was observed for the hst-2 cosmids when NIH3T3 transfection assay was performed in a serum-free medium, whereas induction of morphological transformation was difficult to detect in an ordinary serum-supplemented medium. The hst-2 cDNA was cloned from the NIH3T3 transformant. Nucleotide sequence analysis of the cDNA indicates that the hst-2 gene encodes a 198 amino acid transforming protein containing a signal peptide with the characteristics of a heparin-binding growth factor. The coding sequence was almost identical to the published portion of the exon sequence of the FGF-6 gene, indicating that hst-2 is identical to FGF-6. The hst-2 cDNA fragment, when inserted into an expression vector, was able to transform NIH3T3 cells effectively, and the resulting transformant formed a well-vascularized tumor in nude mice, thus suggesting an angiogenic property similar to some other members of the family. RNA blot analysis revealed the expression of the hst-2 gene in human leukemia cell lines with platelet/megakaryocytic differentiation potential.

Animals↗
PubMed1992

[The metabolism of sulfur containing amino acids in the rat lens].

To determine the metabolism of sulfur containing amino acids in cultured rat lenses, the author studied the uptake and incorporation of radioactive amino acids (3H-leucine, 14C-glycine, 14C-cystine and 35S-methionine) into whole and fractions of the lens, and the effects of diethyl maleate (DEM), the inhibitions of glutathione (GSH) synthesis on them. The uptake and incorporation of radioactive amino acids with the exception of cystine into whole and fractions of the lens were decreased, especially in DEM-additive group. In DEM group, the uptake of cystine into whole lens was suppressed but that in control group was not. The incorporation of cystine into protein fraction (WIS, WS) were increased in DEM group. It was supposed that the decrease in the incorporation of glycine and the increase in that of cystine into protein fractions were related to the formation of high molecular weight proteins. It was also assumed that the decrease of the uptake of cystine into TCA soluble fraction was due to the inhibition of the synthesis of GSH.

Amino Acids, Sulfur↗
PubMed1992

A light and electron microscopic histochemical study on lectin binding to cells with high metastatic potential in Lewis lung carcinoma.

Lectin binding to tumor cells in tissue sections of nonmetastatic and metastatic murine Lewis lung carcinoma (LLC) was assessed by light and electron microscopy using a lectin-gold technique. Ulex europaeus agglutinin-I (UEA-I) and peanut agglutinin (PNA) showed no binding, whereas concanavalin A (Con A), soybean agglutinin (SBA), Dolichos biflorus agglutinin (DBA), Maclura pomifera agglutinin (MPA), and Ricinus communis agglutinin-I (RCA-I) bound equally to the transplanted sites and metastases. However, wheat germ agglutinin (WGA) bound to metastases more highly than to the transplanted sites and there was a statistically significant difference (P less than 0.01) between the transplanted sites and metastases with regard to pre-embedding method. The tumor cells binding to WGA clearly decreased in number after sialic acid pretreatment and were rich in more well-differentiated organelle. In the bromodeoxyuridine (BrdUrd) labeling in vivo, cell proliferation was greater in the metastatic sites than in the transplanted sites. The above findings suggest that glycoconjugates on the tumor cell surface are altered in the process of metastasis and correlate with metastatic potential and cell proliferation.

Animals↗
PubMed1992

[Use of beta-agonist inhalation concomitantly with regular beclomethasone dipropionate in patients with bronchial asthma--as required or on a regular basis].

We investigated whether regular use of beta-agonist inhalation concomitantly with regular beclomethasone dipropionate (BDP) inhalation is necessary in chronic bronchial asthma. Twenty chronic asthmatic patients who were stable on regular BDP and beta-agonist inhalation were studied. After a 2 week observation period, the patients were randomly assigned to two groups. One group received BDP 400 micrograms/day (2 puffs 4 times) and beta-agonist inhalation as required for 4 weeks. This period was followed by 4 weeks of treatment with BDP 400 micrograms/day and regular beta-agonist inhalation. The other group received these treatments in the reverse order. No significant differences among the two groups were observed in attack score, ADL score, sleep score, and %PEFR. In addition, no differences were detected in these parameters between the periods of regular use of beta-agonist and the periods of use as required. The frequency of inhalation of beta-agonist during the use as required period correlated with the sleep score and difference in %PEFR between morning and night, and was significantly lower than the frequency of inhalation during the period of regular. From these results, we conclude that inhalation of beta-agonist on a regular basis is not necessary to achieve the same degree of relief of symptoms as treatment with beta 2-agonist and BDP inhalation on regular basis in patients with chronic asthma.

Administration, Inhalation↗
PubMed1992

[A case of anaplastic carcinoma of the mediastinal goiter].

We reported a case of anaplastic carcinoma of mediastinal goiter. The initial symptom was hoarseness, and thyroid scintigram and venogram revealed mediastinal thyroid malignant tumor, although cervical tumor could not be palpated. Operation was performed with median sternotomy. The size of the tumor was 8 x 6 x 3cm. Histological examination showed papillary adenocarcinoma of left lower pole of the thyroid gland which was transformed into anaplastic carcinoma and extended to the mediastinal cavity. Anaplastic carcinoma of mediastinal goiter is very rare, and our case showed anaplastic transformation from papillary adenocarcinoma.

Adenocarcinoma, Papillary↗
PubMed1991

Lymphocytes with a CD4+ CD8- CD3- phenotype are effectors of experimental cutaneous graft-versus-host disease.

Graft-versus-host disease (GVHD) is known to cause profound dysregulation of the immune system, although its effector mechanisms are poorly understood. We now describe an effector lymphocyte of unusual phenotype in the skin of mice with GVHD. This cell is of donor origin and expresses several T-cell surface proteins including Thy-1, CD2, and CD4 but does not express CD8, CD3, NK1.1, or macrophage antigens. Mononuclear cells of this phenotype are the predominant lymphocyte in the epidermis of mice with GVHD 3 weeks after transplant but are not detected in transplanted mice without GVHD. Isolation and transfer of these lymphocytes into secondary recipients causes epidermal damage characteristic of GVHD. These data demonstrate that CD4+ CD8- CD3- lymphocytes are an important effector population that can be amplified outside the thymus and that can mediate target organ damage of GVHD.

Animals↗
PubMed1991

Increased serum levels of basic fibroblast growth factor in patients with renal cell carcinoma.

The serum level and urinary output of basic and acidic fibroblast growth factors (FGFs) were measured by sandwich enzyme immunoassay (EIA) in patients with renal cell carcinoma. In over fifty percent (16/31) of renal cell carcinoma patients, basic FGF was elevated (greater than 30 pg/ml) in their sera. There is relatively good correlation between serum levels of basic FGF and tumor stage or grade, while urinary daily output of basic FGF did not correlate with increased malignancy. The present results indicate that serum basic FGF level of patients with renal cell carcinoma is a useful diagnostic and prognostic marker for renal cell carcinoma. On the other hand, acidic FGF was not detectable in all sera and urine.

Antibodies, Monoclonal↗
PubMed1991

High-level synthesis of active adenylate cyclase toxin of Bordetella pertussis in a reconstructed Escherichia coli system.

The Bordetella pertussis adenylate cyclase(Cya) toxin-encoding locus (cya) is composed of five genes. The cyaA gene encodes a virulence factor (CyaA), exhibiting adenylate cyclase, hemolytic and invasive activities. The cyaB, D and E gene products are necessary for CyaA transport, and the cyaC gene product is required to activate CyaA. We reconstructed, in Escherichia coli, the cya locus of B. pertussis by cloning the different genes on appropriate vectors under the control of strong promoters and E. coli-specific translation initiation signals. We show that in the absence of additional gene products, CyaA is synthesized at high levels, is endowed with adenylate cyclase activity, but is devoid of invasive and hemolytic activities. CyaC is sufficient to confer upon the adenylate cyclase holotoxin full invasive and partial hemolytic activities. Coexpression of the cyaB, D and E genes neither stimulates nor potentiates the activation brought about by CyaC. This reconstructed system should help to elucidate both the mechanism and the structural requirements of holotoxin activation.

Adenylate Cyclase Toxin↗
PubMed1991

Control of doublesex alternative splicing by transformer and transformer-2 in Drosophila.

Sex-specific alternative processing of doublesex (dsx) precursor messenger RNA (pre-mRNA) regulates somatic sexual differentiation in Drosophila melanogaster. Cotransfection analyses in which the dsx gene and the female-specific transformer (tra) and transformer-2 (tra-2) complementary DNAs were expressed in Drosophila Kc cells revealed that female-specific splicing of the dsx transcript was positively regulated by the products of the tra and tra-2 genes. Furthermore, analyses of mutant constructs of dsx showed that a portion of the female-specific exon sequence was required for regulation of dsx pre-messenger RNA splicing.

Animals↗
PubMed1991

Purification of a Cl-(-)channel protein of sarcoplasmic reticulum by assaying the channel activity in the planar lipid bilayer system.

A Cl- channel protein of sarcoplasmic reticulum (SR) was purified by assaying the channel activity in a planar lipid bilayer system. The light fraction of SR vesicles was solubilized in CHAPS and fractioned by anion exchange, gel filtration, and affinity chromatography with concanavalin A. All fractions in each step were reconstituted into vesicles with asolectin by dialysis and their channel activities were assayed after the vesicles had been fused into a planar lipid bilayer. A 100-kDa protein, different from Ca2(+)-ATPase, was found to form anion channels.

Animals↗
PubMed1991

Structural analysis of a mature hst-1 protein with transforming growth factor activity.

A recombinant hst-1 protein produced in silkworm cells by a recombinant baculovirus, previously shown to be a potent mitogen for NIH3T3 cells and human endothelial cells, also stimulated anchorage-independent growth of NRK-49F cells. Amino acid sequence analysis revealed that the amino-terminal sequence with 58 amino acids was cleaved off in silkworm cells. These results indicated that the mature hst-1 protein consisting of 148 amino acids had transforming growth factor activity.

Amino Acid Sequence↗
PubMed1991

Altered cellular responses to serum mitogens, including platelet-derived growth factor, in cultured smooth muscle cells derived from arteries of patients with moyamoya disease.

Progressive stenosis or occlusion of bilateral internal carotid arteries by fibrocellular intimal thickening results in cerebral ischemia in moyamoya disease. The etiology is unknown. We examined cultured arterial smooth muscle cells (SMC) from scalp arteries of five patients with moyamoya disease. In this study we investigated the responsiveness of the cells in culture to serum mitogens including platelet-derived growth factor (PDGF), a major mitogen of SMC, and compared the response to that of cells derived from age-matched control patients. SMC from patients with moyamoya disease proliferated less rapidly in a medium with 15% serum than did control SMC and responded poorly to the addition of PDGF to 5% serum. PDGF alone did not stimulate SMC in a quiescent state to initiate DNA synthesis in moyamoya disease, without serum factors other than bovine serum albumin, though it significantly stimulated the controls. Simultaneous additions of epidermal growth factor, insulin-like growth factor-I, and PDGF stimulated initiation of DNA synthesis in cells from moyamoya disease, but not as much as PDGF alone did in the controls. Although direct correlations with the pathogenesis of the disease remain to be clarified, the results indicate altered interrelations between serum factors and the cellular responses in vessels of moyamoya disease.

Adolescent↗
PubMed1991

Purification and characterization of macromolecular phagocytosis activators released from platelets.

Substantial amounts of macromolecular activators of phagocytosis from platelets (MAPPs) were released in response to exposure of platelets to the specific agonists thrombin and collagen and to calcium ionophore A23187. Centrifugation of the platelets in culture medium also resulted in a release of MAPPs, but not when the platelets were frozen and thawed prior to centrifugation. In an experiment using outdated platelet concentrates, larger and smaller MAPPs (1-MAPP and s-MAPP, respectively) were purified from the thrombin stimulated supernatant (PRPr-plasma) by sequential steps of ammonium sulfate precipitation, delipidation with ethylacetate, ConA-Sepharose affinity chromatography, MONO Q anion exchange chromatography, and Superose 12 gel filtration. This procedure yielded 59,500-fold and 63,600-fold purified 1-MAPP (0.95 mg) and s-MAPP (0.41 mg), respectively, from 1,320 ml PRPr-plasma containing 84,500 mg protein. By gradient polyacrylamide gel electrophoresis the respective molecular weights (MW) of 1-MAPP and s-MAPP were 290-320 kd and 140-160 kd; isoelectric points were 5.6 and 4.6. Both MAPPs activated neutrophil phagocytosis of IgG-SRBC at concentrations in the range of 1 pM-100 nM. Indirect enzyme-linked immunosorbent assay (ELISA) and comparisons of the concentrations required for phagocytosis activation suggested that the MAPPs were not derived from fibronectin.

Biological Factors↗
PubMed1991

Species differences in the coexistence of 5-hydroxytryptamine and substance P in presynaptic boutons in the cervical ventral horn.

Substance P (SP)- and 5-hydroxytryptamine (5-HT)-containing presynaptic boutons in the cervical ventral horn were studied in chicken, hamster, rat and monkey spinal cords, using PAP and protein A-gold double-labeling techniques in conjunction with monoclonal antibodies. In the chicken, the PAP method demonstrated that SP-immunoreactive boutons contained large spherical dense-cored vesicles (DCVs) whereas 5-HT-immunoreactive boutons displayed both elongated and spherical DCVs. Using the protein A-gold double-labeling technique, 10-nm gold particles for SP were localized over the spherical DCV-containing boutons whereas 15-nm gold particles for 5-HT were localized on elongated DCV-containing boutons. On the other hand, in the other species investigated, both SP- and 5-HT-immunoreactive boutons had similar morphological features as shown by the PAP method; both contained elongated and spherical DCVs. The two different sized gold particles, each of which labeled either 5-HT or SP, were found together over DCVs in a single bouton. These results indicate that 5-HT and SP are contained in different presynaptic boutons in the chicken, although in the hamster, rat and Japanese macaque, the two neurotransmitters/modulators coexist in the same DCVs in a single bouton. Species differences have thus been demonstrated for the coexistence of 5-HT and SP in the spinal ventral horn.

Animals↗
PubMed1991

Prediction of the recurrence of esophageal varices based on portal vein pressure and oxygen tension in portal and peripheral blood.

In 27 variceal patients completely treated by ethanolamine oleate and polidocanol and followed for more than one year, the recurrence of varices was studied by measuring portal vein pressure and oxygen tension in the portal vein and peripheral arteries and veins before and after EIS. Frequent recurrence was observed in patients with increased PVP after EIS and lower or inverse PVO2-VO2 tension after EIS. The recurrence of varices after EIS may thus possibly be predicted based on portal vein pressure and PVO2-VO2 tension differences.

Esophageal and Gastric Varices↗