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Biomedical subjects

Y Takeda

Publications and source records attributed to Y Takeda.

At least 649 records · Page 36Linked to original sources
PubMed1993

Apoptosis of lung cancer cells caused by some anti-cancer agents (MMC, CPT-11, ADM) is inhibited by bcl-2.

To determine whether the apoptotic cell death induced by anti-cancer agents could be inhibited by bcl-2, we established a bcl-2-transfected human small cell lung cancer cell line, SBC-3/Bcl2. SBC-3/Bcl2 showed higher resistance to ADM, CPT-11 and MMC compared with the parental line SBC-3, with relative resistance values of 3.4, 7.6 and 5.7, respectively. However, there was no difference in sensitivity to CDDP, VP-16, ACNU, MTX and taxol between SBC-3 and SBC-3/Bcl2. Agarose gel electrophoresis showed typical DNA fragmentation of SBC-3 following treatment with CPT-11 or MMC, in a concentration-dependent manner. In contrast, the same concentration of the drugs did not induce DNA fragmentation in SBC-3/Bcl2. Treatment with CDDP resulted in the same degree of DNA fragmentation in SBC-3 and SBC-3/Bcl2. These studies indicate that bcl-2 can modulate the cytotoxicity of some anti-cancer agents by inhibiting the process of apoptosis.

Animals↗
PubMed1993

Cyclosporine A induces endothelin-1 release from cultured rat vascular smooth muscle cells.

Since vascular smooth muscle cells in culture are capable of secreting endothelin-1 (ET-1), we investigated the effect of cyclosporine A on ET-1 release from rat vascular smooth muscle cells. Cyclosporine A 10 microM significantly (P < 0.05) enhanced the secretion of ET-1 at 2, 8, 24 and 48 h (6.5 +/- 0.5, 11 +/- 0.7, 19 +/- 0.5, 37 +/- 1.6 fmol/10(6) cells, respectively) compared with vehicle (4.7 +/- 0.3, 8.1 +/- 0.6, 15 +/- 0.4, 27 +/- 2.0 fmol/10(6) cells, respectively). The cyclosporine-induced synthesis of ET-1 by vascular smooth muscle cell may participate in the pathogenesis of cyclosporine-induced vasoconstriction and vasculopathy via an autocrine regulatory mechanism.

Animals↗
PubMed1993

Serum antibody production by oral immunization with dextran B512.

Serum antibodies to dextran were detected when dextran B512 was orally administered to C3H/He mice. The amounts of serum antibodies were increased along with the dose of orally administered dextran B512. For serum antibody production, differences were observed among the strains of mice. C3H/He, C57BL/6 and CBA mice produced high levels of serum antibodies to dextran, while BALB/c and DBA/2 mice produced low levels of serum antibodies. The serum antibodies had groove-type combining sites, as determined by ELISA inhibitory assay.

Administration, Oral↗
PubMed1993

Distribution of the zot (zonula occludens toxin) gene among strains of Vibrio cholerae 01 and non-01.

The distribution of the zot gene that encodes the zonula occludens toxin, a newly described toxin of Vibrio cholerae, among clinical, environmental and food isolates of V. cholerae 01 and non-01 was investigated. Both the zot gene and the ctx gene that encode cholera toxin were found in 247 of 257 clinical strains and 62 of 415 environmental or food isolates of V. cholerae 01. The zot gene, but not the ctx gene was found in 37 strains (one clinical strain and 36 environmental or food isolates). In addition, two of 31 clinical strains and six of 98 environmental or food isolates of V. cholerae' non-01 possessed both the zot gene and the ctx gene. These results demonstrated the predominantly concurrent occurrence of the zot gene and ctx genes among strains of V. cholerae 01 which suggests a possible synergistic role of ZOT in the causation of acute dehydrating diarrhea produced by V. cholerae 01.

Cholera Toxin↗
PubMed1993

U1-70-kd autoantibody-positive mixed connective tissue disease in children. A longitudinal clinical and serologic analysis.

OBJECTIVE: To obtain longitudinal data on the clinical, serologic, and immunogenetic features of children with mixed connective tissue disease (MCTD). METHODS: Eleven children with MCTD were followed up for a mean of 9.8 years. Enzyme-linked immunosorbent assay and immunoblotting were used to analyze sera for autoantibodies to small nuclear ribonucleoprotein polypeptides. HLA types were determined in 9 patients, by microcytotoxicity and DNA typing. RESULTS: All 11 children had anti-U1-70-kd auto-antibodies. Six of 9 were positive for HLA-DR2, 4 of 9 for HLA-DR4, and 9 of 9 for either HLA-DR2 or DR4. Outcomes were favorable with no functional impairment in 8 of the 11 children and were poor in 3. CONCLUSION: The frequency of HLA-DR2/DR4 is increased among children with anti-U1-70-kd autoantibody positive MCTD.

Autoantibodies↗
PubMed1993

Characterization of non-toxic mutant toxins of Vero toxin 1 that were constructed by replacing amino acids in the A subunit.

Three mutant toxins of Vero toxin 1 (VT1) produced by Escherichia coli strains carrying mutant VT1 genes that were constructed by oligonucleotide-directed site-specific mutagenesis were purified to homogeneity. They are E167Q (glutamic acid at position 167 from the N-terminus of the A subunit was replaced by glutamine), R170L (arginine at position 170 from the N-terminus of the A subunit was replaced by leucine) and E167Q-R170L (glutamic acid at position 167 and arginine at position 170 were replaced by glutamine and leucine, respectively). The purified E167Q and E167Q-R170L had markedly decreased activities, such as inhibition of protein synthesis, cytotoxicity to Vero cells and mouse lethality. The decrease in the R170L activities was less than those of the other two mutant VT1s. Neither additive nor synergistic decreases of the activities were observed in the double mutant E167Q-R170L in which two amino acids were replaced. Ouchterlony double gel diffusion showed that antiserum against the purified E167Q-R170L gave a line of identity between mutant VT1s and VT1. Moreover, anti-E167Q-R170L antiserum showed similar activity to that of anti-VT1 antiserum in neutralizing the Vero cell cytotoxicity and mouse lethality of VT1. The data suggest that these mutant VT1s, especially E167Q and E167Q-R170L, may be candidate toxoids that protect against diseases caused by Verocytotoxin-producing E. coli.

Animals↗
PubMed1993

Expression of a truncated guanylate cyclase (GC-C), a receptor for heat-stable enterotoxin of enterotoxigenic Escherichia coli, and its dimer formation in COS-7 cells.

A fragment of guanylate cyclase C (GC-C) of about 1.7 k bp corresponding to amino acids 1-553 spanning the extracellular and transmembrane domains and a portion of the intracellular region was amplified using template cDNA prepared from rat intestinal cells by the polymerase chain reaction method. The cloned 1.7 k bp fragment was inserted into the mammalian expression vector pCGUT and the truncated GC-C expressed on the surface of COS-7 cells was demonstrated to bind heat-stable enterotoxin by photo affinity labeling with 125I-N-5-azidonitrobenzoyl-STh[5-19]. Analysis by sodium dodecyl sulfate-polyacrylamide disc gel electrophoresis showed that the truncated GC-C formed dimers on the surface of COS-7 cells. The intracellular region of GC-C was found not to be necessary for dimer formation by the GC-C. Comparison of the molecular weights of the truncated GC-C expressed in COS-7 cells and Escherichia coli suggested that the truncated GC-C was glycosylated in the mammalian expression system.

Affinity Labels↗
PubMed1993

Purification and some properties of a Vero toxin 2 (Shiga-like toxin II) variant (SLT-IIva) of Escherichia coli isolated from infantile diarrhea.

A variant of Vero toxin 2 (VT2), or Shiga-like toxin II (SLT-II) was purified from a cloned strain of Escherichia coli carrying a gene that encodes SLT-IIva, which is most closely related to SLT-IIv (VT2vp, VTe) in its nucleotide sequence. The purified SLT-IIva showed a slight difference from the purified SLT-IIv (VT2vp) in mobility on polyacrylamide gel disc electrophoresis and SDS-polyacrylamide gel slab electrophoresis and in pI, but both showed a similar potency in biological activities. Ouchterlony double diffusion test revealed that the purified SLT-IIva and SLT-IIv (VT2vp) formed a spur against anti-SLT-IIva and anti-SLT-IIv (VT2vp) antisera.

Animals↗
PubMed1993

Aminoalkylbisphosphonates, potent inhibitors of bone resorption, induce a prolonged stimulation of histamine synthesis and increase macrophages, granulocytes, and osteoclasts in vivo.

Aminoalkyl derivatives of bisphosphonates are potent inhibitors of bone resorption. A single I.P. injection of 4-amino-1-hydroxybutylidene-1,1-bis-phosphonate (AHBuBP) induced a prolonged enhancement of histidine decarboxylase (HDC) activity in the bone marrow, spleen, lung, and liver of mice and resulted in an increase in histamine. The induction of HDC by the agent was dose dependent (16-80 mumol/kg) and peaked 3-4 days after its injection (40 mumol/kg). Repeated S.C. injections of smaller doses of AHBuBP (0.32 or 1.6 mumol/kg/day) for 4 days also enhanced HDC activity. However, the minimum dose capable of inhibiting bone resorption (0.064 mumol/kg/day) was lower than that inducing HDC. Unexpectedly, AHBuBP, at the doses inducing HDC, increased macrophages, granulocytes, and even osteoclasts. The size of osteoclasts was also enlarged by the agent. Another aminobisphosphonate, 3-amino-1-hydroxypropylidene-1,1-bisphosphonate, but none of non-amino derivatives, also exhibited essentially the same effects as those of AHBuBP. These results indicate that in spite of increase in osteoclasts and their enlargement, bone resorption is still inhibited by amino bisphosphonates. As granulocyte and granulocyte-macrophage colony-stimulating factors and interleukin-3 induce HDC in hematopoietic organs, and histamine has a hematopoietic activity, the HDC induction by aminobisphosphonates may be relevant to the proliferation of progenitor cells of macrophages, granulocytes, and osteoclasts.

Alendronate↗
PubMed1993

The successful surgical management of perforation after endoscopic sphincterotomy: report of two cases.

Retroperitoneal perforation following endoscopic sphincterotomy (EST) is an infrequent but serious complication with a high mortality rate in patients who do not receive prompt treatment. We report herein two cases of perforation, diagnosed 3 and 7 days after EST, one of whom was treated by choledochojejunostomy (Roux-en-Y) and suturing of the perforation site with jejunal patching, and the other by pancreatoduodenectomy. Both operations were successful as emergency treatments and therefore we consider that radical surgery should be attempted for cases of perforation after endoscopic sphincterotomy with a delayed diagnosis.

Aged↗
PubMed1993

Surgery for cholelithiasis in cirrhotic patients.

Although biliary tract surgery for cholelithiasis is performed frequently in Japan, cirrhotic patients require special consideration. Postoperative complications after biliary tract surgery were studied in 23 patients with liver cirrhosis and associated cholelithiasis, 9 of whom had no complications, 8 had minor complications, and 6 had severe complications. Concerning the relation between Child's classification and postoperative complications, no complications were seen in four Child's type A patients, but seven of ten (70%) Child's type B patients and seven of nine (78%) Child's type C patients developed complications. Two (20%) of the Child's type B patients and four (44%) of the Child's type C were severe, and three of the latter group died. Regarding the preoperative laboratory findings, significant differences were seen between the patients without complications and those with severe complications in serum bilirubin, albumin, and ICG R15 values. Of the six patients with severe complications, five had choledocholithiasis, three of whom died of liver failure, while two developed biliary peritonitis caused by insufficient fistula formation after removal of the T-tube. Thus, for the treatment of choledocholithiasis in patients with severe cirrhosis, avoiding surgical invasion through the use of such techniques as endoscopic papillotomy is recommended whenever possible.

Biliary Tract Surgical Procedures↗
PubMed1993

Oncocytic hyperplasia in the human minor salivary glands: a post-mortem study.

Oncocytic hyperplasia in the human labial salivary glands was sought in a series of 217 post-mortem subjects. Oncocytic change occurred in 183 subjects and hyperplasia was found in 19 of those (the overall incidence being 8.8%), ranging in age from the third decade to the ninth. The sex distribution showed a significantly greater rate in males (16 of 139 males, 11.5%; 3 of 78 females, 3.8%). Oncocytic hyperplasia occurred in the duct system, and not in the acinar regions; it was frequently seen in the interlobular and intralobular ducts. Oncocytic hyperplasia was classified into four types; focal hyperplasia of the duct wall resulting in partial thickening of the duct wall; marked hyperplasia resulting in thickening of the duct wall, extending over half of the circumference; marked hyperplasia extending to the whole duct wall and intralobular adeno-tubular hyperplasia with or without cystic dilatation. About half of the subjects with oncocytic hyperplasia showed a few hyperplastic foci in one gland. The changes increased in severity in older subjects.

Adolescent↗
PubMed1993

Haemodynamic changes in IUGR fetus with chronic hypoxia evaluated by fetal heart-rate monitoring and Doppler measurement of blood flow velocity.

The measurement of fetal blood flow velocity and 24 h monitoring of fetal heart-rate (FHR) using a computer were performed to clarify the haemodynamics of growth-retarded fetuses with chronic hypoxia. One hundred normal-growth and 18 growth-retarded fetuses were analysed. All the growth-retarded fetuses with chronic hypoxia were characterised by abnormal blood flow velocity waveforms (with the pulsatility index in the descending aorta below the -1.0 SD and in the middle cerebral artery above the +1.0 SD for our reference range, from 100 normal-growth fetuses). In the latter, the incidence of accelerations of defined size and variability in FHR patterns showed a diurnal variation after 30 weeks' gestation. The initial change in FHR patterns during hypoxia in 11 growth-retarded fetuses, resulting in fetal distress, was a derangement of diurnal variations in FHR patterns, followed by a decrease in variability. A rapid increase in blood flow velocity in the middle cerebral artery with the advance of hypoxia was observed before the onset of distress. Maternal low-dose oxygen inhalation elicited a temporary increase in FHR variability in the growth-retarded but not in normal fetuses. Re-inhalation after 1 h elicited a similar change, suggesting that intermittent rather than continuous, oxygen inhalation may be more effective.

Blood Flow Velocity↗
PubMed1993

Endoscopic evaluation of the depth of invasion of the depressed type early gastric cancer and apparently early advanced cancer in cases of a peptic ulcer within the cancer lesion.

Depressed-type early and apparently early advanced cancers were divided into two groups according to whether or not an associated peptic ulcer was present within the cancer lesion, and the accuracy of preoperative endoscopic diagnosis was reviewed. As a result it was found that evaluation of depth of invasion was more difficult in the ulcer [UL(+)] group than in the group without an ulcer [UL(-)]. In the UL(+) group it was difficult to identify endoscopic findings which indicate depth of invasion at the tip of the folds, the volume of cancer invasion of the deeper layers was small, and there many cases of invasion of deeper layers in a portion of the margins of the peptic ulcers.

Adenocarcinoma↗
PubMed1993

Formation of 18-deoxy-19-noraldosterone by a human aldosterone-producing adenoma.

The recently synthesized 18-deoxy-19-noraldosterone is a potent aldosterone antagonist. In the present study we demonstrate the in vitro formation of 18-deoxy-19-noraldosterone from 19-noraldosterone in a human aldosterone-producing adenoma and normal adrenal tissue. The metabolite was isopolar, cochromatographed with the authentic standard on high-performance liquid chromatography, and the identity was further analyzed by mass spectrometry. The possible role of 18-deoxy-19-noraldosterone in primary aldosteronism is also discussed.

Adenoma↗
PubMed1993

Effects of growth hormone on follicle growth, oocyte maturation, and ovarian steroidogenesis.

OBJECTIVES: To assess the effects of GH on follicle growth, oocyte maturation, ovulation, and ovarian steroidogenesis. DESIGN: In vitro perfused rabbit ovary. INTERVENTIONS: The rabbit ovaries were perfused with medium alone, with GH at 1, 10, 100, or 200 ng/mL, or with 50 IU hCG for 12 hours. MAIN OUTCOME MEASURES: The follicle diameter, the percent change in follicle diameter, the percentage of oocytes achieving germinal vesicle breakdown, and the production of P and E2 by the perfused rabbit ovaries. RESULTS: The addition of GH to the perfusate increased the follicle diameter at 12 hours after perfusion in a dose-dependent manner. The percent change in follicle diameter in GH-treated ovaries did not differ significantly from that in hCG-treated ovaries at each time point of perfusion. However, ovulation did not occur in either the control ovaries or the experimental ovaries treated with GH. Exposure to GH at a concentration of > 10 ng/mL significantly stimulated the resumption of meiosis, as compared with the contralateral control ovaries. Although the concentration of P in the perfusate did not differ significantly between GH-treated and control ovaries, GH stimulated E2 production by the perfused rabbit ovaries in a dose-dependent manner. CONCLUSIONS: Growth hormone acts on the rabbit ovary to stimulate follicle growth, oocyte maturation, and ovarian E2 production.

Animals↗