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Biomedical subjects

S Takeuchi

Publications and source records attributed to S Takeuchi.

At least 127 records · Page 7Linked to original sources
PubMed2000

In vitro fertilization and intracytoplasmic sperm injection for couples with unexplained infertility after failed direct intraperitoneal insemination.

PURPOSE: The objective was to determine the optimal insemination technique in patients undergoing in vitro fertilization (IVF) after failed direct intraperitoneal insemination (DIPI) and the outcome of intracytoplasmic sperm injection (ICSI) in such cases. METHODS: In case-control studies, 53 couples with unexplained infertility who underwent IVF after four failed DIPI cycles were compared with 75 couples with tubal or endometriosis infertility as controls. Thirty couples with unexplained infertility after failing to conceive with DIPI and conventional IVF who underwent ICSI and 58 couples with male-factor infertility as controls also were compared. Fertilization cleavage, embryo quality, implantation, and pregnancy were compared after IVF and after ICSI. RESULTS: There was a significant difference in fertilization rates after IVF between cases of unexplained infertility after failing to conceive with DIPI (40.4%) and patients with tubal or endometriosis infertility (67.9%). There also was a significant difference in total fertilization failure rates between the two groups (30.4% and 3.9%, respectively). There was a slight but significant difference in numbers of fertilized oocytes after ICSI between patients with low fertilization rate undergoing IVF after failing to conceive DIPI (85.8%) and patients with male factor (90.4%). Total fertilization failure was not observed in these cases. CONCLUSIONS: Couples with unexplained infertility after failing to conceive with DIPI show a failed fertilization or a low fertilization rate after IVF. However, they demonstrated a good chance of becoming pregnant after subsequent ICSI, even with statistically significant difference in fertilization rate as compared with male-factor cases.

Adult↗
PubMed2000

Cone electroretinogram amplitude growth with light adaptation in patients with retinitis pigmentosa.

PURPOSE: It has been hypothesized that the increase in the b-wave during light adaptation is directly related to the level of cone malfunction in patients with retinitis pigmentosa (RP). Because this hypothesis has important bearing on the mechanism for the increase in the electroretinogram (ERG), we examined the increase in the amplitude of the cone ERG during light adaptation in patients with typical RP. METHODS: Cone ERGs were recorded to Ganzfeld white flash stimuli in the presence of white background illumination in 51 RP patients and in 27 normal subjects. RESULTS: In the normals, the increase in the b-wave amplitude during light adaptation ranged from 14-92% of the dark-adapted amplitude. All RP patients showed an amplitude increase that ranged from 5 to 100% of the baseline amplitude. This increase was not significantly different from that of the normals (p = 0.71, unpaired t-test). The baseline amplitudes and the increase in the relative amplitude were weakly correlated in the RP patients (r = 0.31; p = 0.029). No significant difference was observed in the amplitude increase between patients with near normal b-wave implicit times and those with delayed times (p = 0.17, unpaired t-test). Changes of the b-wave implicit time were not significantly different from those in the controls. CONCLUSION: These findings that the changes in the cone ERG with light adaptation in the RP patients were very similar to those in normal subjects do not support the proposed hypothesis that the increase in the b-wave amplitude during light adaptation was directly related to the level of cone malfunction.

Adaptation, Ocular↗
PubMed2000

A possible mechanism for feedback regulation of the mouse tyrosinase gene by its 3' non-coding RNA fragments.

The 5' upstream regulatory region of the mouse tyrosinase gene contains a long (GA)n sequence, that may be capable of adopting a triple-helical conformation (triplex). We analyzed protein-DNA interactions in a part of the 5' upstream region containing the (GA)n sequence by gel retardation analysis and found evidence for a cell type-specific protein(s) that bound to this region. We also found a (TC)10 sequence about 100 bp downstream from a polyadenylation site of the gene. Examination of tyrosinase cDNAs and Northern analysis indicated that this sequence is transcribed and removed during 3' end-processing of the mRNA. Based on the hypothesis that the (TC)10 sequence binds to the (GA)n sequence and forms an intermolecular triplex, we performed the same gel retardation assay in the presence of the 3' non-coding RNA fragments containing the (UC)10 sequence. The probe DNA failed to interact with the cell type-specific protein(s). These results suggest a novel hypothesis for the regulation of the mouse tyrosinase gene, i.e. that the 3' non-coding RNA fragments of mouse tyrosinase transcripts suppress its own expression at the transcriptional level. This might occur by preventing cell type-specific protein factor(s) from binding to the regulatory cis-elements in the 5' upstream region of the gene, possibly through a triplex formation, although this hypothesis remains to be proven.

3' Untranslated Regions↗
PubMed2000

Effects of peroxisome proliferator-activated receptor-alpha and -gamma agonist, JTT-501, on diabetic complications in Zucker diabetic fatty rats.

This study has investigated the effects of JTT-501, a peroxisome proliferator-activated receptor (PPAR)-alpha and PPAR-gamma agonist, on the pathogenesis of diabetic complications in the Zucker diabetic fatty (ZDF) rats, a model of type 2 diabetes. Comparison is made with troglitazone, a PPAR-gamma agonist. The ZDF rats exhibited hyperglycaemia and hyperlipidaemia, and developed diabetic complications such as cataract, nephropathy, and neuropathy. Treatment with JTT-501 from the prediabetic stage controlled glycaemia and lipidaemia, and prevented the development of diabetic complications. Troglitazone was less effective in controlling serum cholesterol and neuropathy. ZDF rats developed diabetic osteopenia with reduced bone turnover, and this was prevented by JTT-501 and troglitazone, possibly mediated by increased bone turnover and bone formation. Since JTT-501 controlled glycaemia and lipidaemia in ZDF rats and prevented several diabetic complications, it is suggested that treatment with JTT-501, which activates both PPAR-alpha and PPAR-gamma, could provide a valuable therapeutic approach against diabetic complications in type 2 diabetes.

Absorptiometry, Photon↗
PubMed2000

Mouse Ror2 receptor tyrosine kinase is required for the heart development and limb formation.

BACKGROUND: A mouse receptor tyrosine kinase (RTK), mRor2, which belongs to the Ror-family of RTKs consisting of at least two structurally related members, is primarily expressed in the heart and nervous system during mouse development. To elucidate the function of mRor2, we generated mice with a mutated mRor2 locus. RESULTS: Mice with a homozygous mutation in mRor2 died just after birth, exhibiting dwarfism, severe cyanosis, and short limbs and tails. Whole-mount in situ hybridization analysis showed that mRor2 was expressed in the branchial arches, heart and limb/tailbuds, in addition to the developing nervous system. The mutants had cardiac septal defects, mainly a ventricular septal defect. In addition, an examination of the skeletal systems revealed that the mutants had shorter limbs, vertebrae and facial structure, with a particular defect in their distal portions, and that almost no calcification was observed in their distal limbs. Histological examination showed abnormalities in the chondrocytes. CONCLUSIONS: Our findings suggest that mRor2 plays essential roles in the development of the heart and in limb/tail formation, in particular cardiac septal formation and ossification of distal portions of limbs and tails.

Animals↗
PubMed2000

Metallic stents for malignant and benign ureteric obstruction.

OBJECTIVE: To report our experience of using metallic stents to treat ureteric obstruction caused by malignant or benign disease. PATIENTS AND METHODS: Nine patients with obstruction in 11 ureters caused by malignant or benign disease (mean age 61 years, range 35-82, mean follow-up 7 months, range 3-11) were treated using metallic stents. A balloon-expandable metallic stent was used in one patient and self-expandable metallic stents in the remaining eight. All stents were inserted via a percutaneous antegrade approach. RESULTS: Of the 11 ureters, nine remained patent with no further manipulation during the follow-up of 3-11 months. An additional stent was placed in continuity with the first in two ureters of two patients at 4 and 5 weeks after the first procedure because of persistent obstruction. After the second intervention, their obstruction was improved. Transient vesico-ureteric reflux occurred in two of three stented distal ureters, but the reflux resolved spontaneously within 2 months after stent implantation. Ureteric patency was maintained in all patients and no major complications related to stenting occurred during the follow-up. Two patients died from cervical cancer at 3 and 5 months after stenting. CONCLUSION: In patients with difficult ureteric obstructions a metallic stent provides a safe and effective alternative to an indwelling double-pigtail catheter or percutaneous nephrostomy.

Aged↗
PubMed2000

Improvement of portal flow and hepatic microcirculatory tissue flow with N-acetylcysteine in dogs with obstructive jaundice produced by bile duct ligation.

OBJECTIVE: To find out if N-acetylcysteine (NAC) would improve hepatic circulation in dogs with obstructive jaundice. DESIGN: Open laboratory study. SETTING: University hospitals, Japan and France. MATERIALS: 14 male beagle dogs and 10 male Wistar rats. INTERVENTIONS: Obstructive jaundice was produced by ligation of the common bile duct (CBD) for 7 days in both dogs and rats. Either 5% dextrose (control group, n = 7) or NAC (NAC group, n = 7) was given to dogs. Sinusoidal endothelial cells were obtained from rats after ligation by elutriation, and varying amounts of NAC were given. MAIN OUTCOME MEASURES: The volumes of portal blood flow and hepatic microcirculatory tissue flow were reduced after ligation of the CBD, but those increased after NAC had been given to dogs with obstructive jaundice. NAC increased the concentrations of plasma cyclic 3',5'-guanosine monophosphate (cGMP). It also increased concentrations of serum and hepatic-reduced glutathione, and hepatic adenosine triphosphate (ATP) in cholestatic dogs, and secretion of cGMP from sinusoidal endothelial cells from rats with obstructive jaundice. CONCLUSION: These results suggest that NAC given intravenously effectively improves hepatic circulation and hepatic function in dogs with obstructive jaundice.

Acetylcysteine↗
PubMed2000

(2-Carbamoylethyl)bis(dimethylglyoximato-N, N')

The 2-carbamoylethyl and 2-(methylcarbamoyl)ethyl groups in the title cobaloxime complexes, [Co(C(4)H(7)N(2)O(2))(2)(C(3)H(6)NO)(C(12)H(13)N)].C(2)H(6)O and [Co(C(4)H(7)N(2)O(2))(2)(C(4)H(8)NO)(C(10)H(13)NO(2))], were isomerized to 1-carbamoylethyl and 1-(methylcarbamoyl)ethyl groups, respectively, on exposure to visible light in the solid state. Although both the crystal structures and the intermolecular hydrogen bonds are different in the two crystals, similar reaction rates were observed.

Journal Article↗
PubMed2000

Genetic and biochemical properties of a hemolysin (pyolysin) produced by a swine isolate of Arcanobacterium (Actinomyces) pyogenes.

Arcanobacterium (Actinomyces) pyogenes, a causative agent of various pyogenic diseases in domestic animals, produces a hemolysin which is thought to be an important virulence factor. This hemolysin was purified from the culture supernatant of A. pyogenes swine isolate. The purified hemolysin showed a single band with a molecular mass of 56 kDa on SDS-polyacrylamide gel electrophoresis, and its isoelectric point was 9.2. The activity of this hemolysin was not enhanced by the addition of L-cysteine or sodium thioglycolate, but it was inhibited by cholesterol. The gene encoding the hemolysin was cloned, sequenced and expressed in Escherichia coli by means of ZAP Express vector. Analysis by SDS-polyacrylamide gel electrophoresis with immunoblotting showed that the molecular weight of the hemolysin expressed in E. coli is the same as that of the hemolysin purified from A. pyogenes. Nucleotide sequence analysis revealed an open reading frame of 1,605 bp encoding a 534 amino acid protein of 57,989 Da. The nucleotide sequence of the hemolysin gene from A. pyogenes swine isolate differed only slightly (97.6% identity) from the sequence of plo gene from A. pyogenes strain BBR1 reported by Billington et al (J. Bacteriol. 179: 6100-6106, 1997). The cysteine residue existed in the undecapeptide region of the hemolysin, which is highly conserved in thiol-activated cytolysins (cholesterol-binding cytolysins), and is replaced with alanine. Therefore, the hemolysin of A. pyogenes seems to be a novel member of the thiol-activated cytolysin family.

Actinomycetaceae↗
PubMed2000

Isolation of differentiated squamous and undifferentiated spindle carcinoma cell lines with differing metastatic potential from a 4-nitroquinoline N-Oxide-induced tongue carcinoma in a F344 rat.

One differentiated squamous cell carcinoma (SCC) cell line (RSC3-E2) and two undifferentiated tumor cell lines (RSC3-LM and RSC3-E2R) with different metastatic potential were established from a 4-nitroquinoline N-oxide (4NQO)-induced differentiated SCC in F344 rat tongue. The RSC3-E2 subline was isolated from a parental cell line (RSC3-P) by single cell cloning in vitro, whereas the RSC3-LM subline was isolated from a lung metastatic focus after subcutaneous (s.c.) injection of RSC3-P cells. The RSC3-E2R cell line was isolated from a lung metastatic focus following s.c. injection of RSC3-E2 cells after X-irradiation in vitro. The RSC3-E2 cell line is keratin-positive and grows as a keratinizing tumor in nude mice, whereas RSC3-LM and RSC3-E2R cells are keratin-negative, vimentin-positive and form undifferentiated tumors. When s.c. injected into nude mice, the RSC3-E2 cell line proved to be non-metastatic, while the RSC3-LM cell line was metastatic by both hematogenous and lymphogenous routes, and the RSC3-E2R cell line was metastatic only hematogenously. In vitro relative growth rates and in vitro invasion activity of these cell lines were in the order RSC3-LM > RSC3-E2R > RSC3-E2. Chromosome analysis revealed two peaks with modal chromosome numbers of 83 and 78 for RSC3-P cells and single peaks at 83, 78 and 56 for RSC3-LM, RSC3-E2 and RSC3-E2R cell lines, respectively. Common structural abnormalities on chromosome 11 were shared by all cell lines. Mutation analysis of the p53 gene using a yeast functional assay demonstrated RSC3-LM cell line to have a point mutation at codon 269, whereas RSC3-E2 and RSC3-E2R had double mutations at codons 106 and 170 on each allele. These results suggest that the two undifferentiated RSC3-LM and RSC3-E2R tumor cell lines with different metastatic potential were generated from differentiated SCC cells via different genetic pathways as a consequence of tumor progression in vivo and in vitro, respectively. These cell lines should provide a useful model for understanding mechanisms of hematogenous and lymphogenous metastasis, as well as tumor progression of oral SCCs.

4-Nitroquinoline-1-oxide↗
PubMed2000

Macrophage migration inhibitory factor levels in the vitreous of patients with proliferative diabetic retinopathy.

AIMS: To assess the potential role of macrophage migration inhibitory factor (MIF) in the pathogenesis of proliferative diabetic retinopathy (PDR). METHODS: MIF levels were assayed in the vitreous and paired serum samples of 73 consecutive patients with PDR (32 eyes) and macular hole or idiopathic epiretinal membrane (controls, 41 eyes). An enzyme linked immunosorbent assay technique was used to determine the concentrations of MIF. RESULTS: The median vitreous level of MIF was 11.93 ng/ml (range 4.16-103.85) in the patients with PDR, and 1.79 ng/ml (undetectable-8.93) in the controls. Vitreous levels in eyes with PDR were significantly greater than those in the controls (p<0.0001). Vitreous levels were significantly higher than serum levels in eyes with PDR (p=0.0026). MIF levels were significantly higher in the vitreous of PDR patients with severe fibrous proliferation than in those with slight proliferation (p<0.05). CONCLUSION: The results indicate increased levels of MIF in the vitreous of patients with PDR and a significant association between MIF levels and grades of fibrous proliferation, suggesting the possibility that MIF may play a part in the development of the proliferative phase of PDR.

Adult↗
PubMed2000

Clinical and epidemiological features of acute follicular conjunctivitis with special reference to that caused by herpes simplex virus type 1.

BACKGROUND/AIMS: It is reported by the national surveillance of ocular infectious diseases in Japan that 4.3% of cases of epidemic keratoconjunctivitis (EKC) diagnosed clinically were caused by herpes simplex virus (HSV). Clinical and virological studies of patients with HSV conjunctivitis were carried out. METHODS: The study population consisted of 478 patients with acute follicular conjunctivitis. Virological analysis was carried out for adenovirus (Ad) and HSV by the cell culture method and fluorescein antibody (FA) method. Polymerase chain reaction for Chlamydia trachomatis was also carried out. RESULTS: From 23 patients, HSV type 1 was isolated but Ad or C trachomatis was not isolated. 87% of cases were unilateral. Most cases showed clinical resolution within 9 days. Early corneal lesions and preauricular lymphadenopathy were less frequent in HSV conjunctivitis than in adenoviral conjunctivitis, especially that due to subgenus D. No case showed a positive result for HSV by the FA method using conjunctival swabs; however, the FA test was positive in all strains isolated by cell culture. CONCLUSIONS: These results indicate that it is difficult clinically to differentiate HSV conjunctivitis from adenoviral conjunctivitis in the acute stage, since the clinical features of adenoviral conjunctivitis are similar to those of HSV conjunctivitis. A biological difference may exist between HSV strains causing keratitis and conjunctivitis.

Acute Disease↗
PubMed2000

Phase II study of irinotecan and cisplatin as first-line chemotherapy in advanced or recurrent cervical cancer.

Irinotecan (CPT-11) and cisplatin are singly active against cervical cancer. We evaluated the efficacy and toxicity of CPT-11 plus cisplatin as first-line chemotherapy in patients with advanced or recurrent cervical cancer. Twenty-nine chemotherapy-naive patients with advanced or recurrent cervical cancer were treated with CPT-11 (60 mg/m(2)) on days 1, 8, and 15 by intravenous infusion over 90 min, followed by cisplatin (60 mg/m(2) i.v.) on day 1 over 90 min. The patients' median age was 57 years (range 35-75). Nineteen patients (66%) had advanced primary disease. Six patients with recurrent disease (21%) had been treated with prior radiotherapy. The remaining 4 patients (14%) had residual or recurrent disease after radical surgery. The histologic diagnoses were squamous cell carcinoma in 25 patients (87%), adenocarcinoma in 3, and adenosquamous cell carcinoma in 1. All eligible patients were included in the toxicity and response analysis based on the intent to treat. Two patients (7%) achieved a complete response and 15 (52%) a partial response (overall response rate: 59%, 95% confidence interval; 41-74%). Stable disease was recorded in 6 patients (21%) and progressive disease in 3 patients (10%). In 3 patients, image-guided evaluation of response was judged to be unfeasible at the time of independent extramural review (10%). The median time to response was 32 days (range 16-62 days). The median survival was 27. 7+ months (range, 6.4-52.8+ months). Two dose-limiting side effects were observed: grade 3 (28%) or 4 (45%) neutropenia and grade 3 (7%) or 4 (7%) diarrhea. Other severe toxicities included anemia (45%), thrombocytopenia (3%), nausea/vomiting (31%), and alopecia (7%). The combination of CPT-11 with cisplatin is an active regimen for treatment of advanced or recurrent cervical cancer albeit with a significant degree of myelosuppression.

Adult↗
PubMed2000

Immunocytochemical and immunoelectron-microscopic study of somatotrophs in ICR and nonobese diabetic mice.

Somatotrophs (GH cells) were classified immunoelectron microscopically into three types mainly on the basis of the size of secretory granules in the mouse pituitary of ICR strain. Type I cells contained large secretory granules. Type II cells contained both large secretory granules and small secretory granules. Type III cells contained small secretory granules. All three types of GH cells were found from the neonatal ages to adult. The relative proportion of three types did not change with age, and no sex differences in the relative proportion of the cell types were detected. Type I cells predominate in all age groups observed. In 60-day-old male mice percentages of each type were as follows: type I 93.7 +/- 0.1%, type II 5.4 +/- 0.8%, and type III 0.9.0 +/- 0.4% (n = 5), and in 60-day-old female mice type I 95.2 +/- 0.1%, type II 2.7 +/- 0.5%, and type III 2.1 +/- 0.9% (n = 5). The maximum diameters of the large secretory granules increased from 7 to 60 days of age. The small secretory granules similarly increased in size in female mice, but those in male mice did not change. In the diabetic female mice of the nonobese diabetic (NOD) strains, GH cells in diabetic mice became smaller, and the number and size of secretory granules decreased, indicating diminished GH secretion. However, the relative proportion of each subtype of GH cells did not differ irrespective of the occurrence of diabetes.

Animals↗
PubMed2000

Estimation of stem cell fractions in peripheral blood stem cell harvest by using an SE-9000 hematology analyzer.

We inquired whether stem cell fractions in peripheral blood stem cell harvest could be precisely detected by using a hematopoietic progenitor cell (HPC) counting system applied to an automated hematology analyzer, SE-9000. Although there was an apparent increase in the HPCs 20 h after storage in nondiluted conditions, samples diluted with RPMI-1640 containing 1.0 mg/ml EDTA-2K showed a relatively stable number of HPCs. There was a significant relationship between HPCs and CD34 cells (n = 75, r = 0.769). This method may represent the least expensive and most time-effective way for stem cell estimation in harvest products.

Anticoagulants↗
PubMed2000

Identification of epidermal growth factor mRNA-expressing cells in the mouse anterior pituitary.

Epidermal growth factor (EGF) produced within the pituitary gland is associated with the growth of pituitary cells in rats. The aim of the present study was to localize EGF- and EGF receptor-expressing cells, and to clarify the involvement of EGF in DNA replication in 2-month-old male mouse pituitary cells. In situ hybridization of the pituitaries of these mice demonstrated that EGF mRNA was expressed in the anterior and intermediate lobes. Within the anterior pituitary, EGF mRNA-expressing cells were medium-sized and round, and made up 40% of the total number of secretory cells. EGF receptor mRNA was only detected in anterior pituitary cells. Forty-seven percent anterior pituitary cells expressed EGF receptor mRNA. An immunocytochemical study showed that most somatotropes and some mammotropes expressed EGF mRNA. When anterior pituitary cells were enzymatically dissociated and cultured in serum-free medium, RT-PCR demonstrated both EGF mRNA and EGF receptor mRNA expression. Treatment with EGF (1 and 10 ng/ml) for 5 days stimulated DNA replication in mammotropes and corticotropes. These results indicate that the DNA replication in mammotropes and corticotropes is regulated by the paracrine and/or autocrine activity of EGF produced at least in part by these cell types themselves.

Animals↗
PubMed2000

Influence of cardiopulmonary bypass temperature on circulatory pathophysiology and clinical outcomes.

This study was designed to investigate the effects of cardiopulmonary bypass (CPB) perfusion temperature. Forty-four patients who had undergone elective coronary bypass surgery were randomly divided into 2 groups (22 patients each) according to their perfusion temperature (N group=36 degrees C; L group=30 degrees C). The concentrations of endogenous catecholamines, complements, elastase, serotonin, arachidonic acid metabolites and endothelin underwent various changes throughout the CPB but did not exhibit any statistical differences in either group. None of the substances measured correlated with systemic vascular resistance at any time. The temperature of the perfusion appears to be a major determinant of vascular tone. The postoperative PO2 was better, and postoperative pulmonary vascular resistance lower in the N group (p<0.05), most likely because of a much larger water balance during hypothermic CPB (p<0.01). The postoperative blood loss was statistically less in the N group (p<0.05). Although apparent brain damage, evidenced by the leakage of creatine kinase-BB, was not seen, the jugular bulb venous hemoglobin saturation levels (<50% in 27% of the N group, p<0.05) and higher lactate levels suggested that normothermic perfusion was relatively disadvantageous. It is concluded that normothermic CPB was relatively safe and advantageous with regard to hemostasis and pulmonary function.

Aged↗