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Biomedical subjects

S Ohshima

Publications and source records attributed to S Ohshima.

At least 109 records · Page 6Linked to original sources
PubMed1997

Detection of c-Ki-ras oncogene mutation in gastric adenomas with formalin-fixed, paraffin-embedded biopsy materials.

Point mutations at codon 12 of the c-Ki-ras gene were investigated in 103 biopsy tissues from 38 patients with gastric adenoma. DNA from minute specimens of formalin-fixed paraffin-embedded tissue was amplified by nested polymerase chain reaction (PCR) and the restriction fragment length polymorphism (RFLP) method was used to detect mutations of the c-Ki-ras gene. Mutations were detected in 4 of the 38 gastric adenomas (10.5%), but were not detected in intestinal metaplasias and gastric adenocarcinomas. Of the 4 mutation-positive gastric adenomas, the GGT sequence in codon 12 changed to GAT in 2 cases, to GTT in 1 case and to TGT in 1 case. We classified gastric adenomas into three degrees of atypia; mutations were detected only in biopsy tissues with moderate and severe atypia but were not detected in biopsy tissues with mild atypia. When different biopsy tissues from a mutation-positive gastric adenoma were examined, the mutation was not always detected in every tissue sample examined. This suggests that mutations are not homogeneously distributed, even in the same adenoma. It is possible to follow up the mutation of biopsy materials of gastric adenoma by this method.

Adenoma↗
PubMed1997

The role of retinal bipolar cell in early vision: an implication with analogue networks and regularization theory.

A linear analogue network model is proposed to describe the neuronal circuit of the outer retina consisting of cones, horizontal cells, and bipolar cells. The model reflects previous physiological findings on the spatial response properties of these neurons to dim illumination and is expressed by physiological mechanisms, i.e., membrane conductances, gap-junctional conductances, and strengths of chemical synaptic interactions. Using the model, we characterized the spatial filtering properties of the bipolar cell receptive field with the standard regularization theory, in which the early vision problems are attributed to minimization of a cost function. The cost function accompanying the present characterization is derived from the linear analogue network model, and one can gain intuitive insights on how physiological mechanisms contribute to the spatial filtering properties of the bipolar cell receptive field. We also elucidated a quantitative relation between the Laplacian of Gaussian operator and the bipolar cell receptive field. From the computational point of view, the dopaminergic modulation of the gap-junctional conductance between horizontal cells is inferred to be a suitable neural adaptation mechanism for transition between photopic and mesopic vision.

Animals↗
PubMed1997

Dose-response effects of adrenergic drugs on axial movements of the rat mandibular incisor and on arterial blood pressure.

Axial tooth movements and arterial blood pressure were measured following the intravenous injection of 0, 0.01, 0.1, 1, or 10 micrograms/kg of adrenaline, noradrenaline or isoprenaline. Adrenaline caused a dose-dependent, rapid, extrusive tooth movement with a nearly simultaneous increase in blood pressure, followed by a marked intrusive tooth movement and a decrease in blood pressure. Noradrenaline caused a dose-dependent, rapid, extrusive tooth movement and an increase in blood pressure, but a subsequent intrusive tooth movement and decrease in blood pressure were not so marked. Isoprenaline caused a marked intrusive tooth movement and a decrease in blood pressure, without an extrusive tooth movement and increase in blood pressure. The time required to reach the maximum intrusive tooth movement was delayed after that to reach the maximum decrease in blood pressure. The recovery time of the intrusive tooth movement was much more delayed than that of blood pressure. These results suggest that the extrusive movement of the rat incisor was primarily related to the rise of arterial blood pressure due to stimulation of vascular alpha-receptors. It is also suggested that stimulation of beta-receptors would probably cause vasodilatation of arteries that would make the pressure in the small vessels in the microcirculation of the socket fall, so reducing the volume of blood and interstitial fluid in the socket followed by a marked and continuing intrusive tooth movement.

Adrenergic Agonists↗
PubMed1997

Effectiveness of an antioxidant in preventing restenosis after percutaneous transluminal coronary angioplasty: the Probucol Angioplasty Restenosis Trial.

OBJECTIVES: The Probucol Angioplasty Restenosis Trial was a prospective, randomized, controlled study that investigated the effectiveness of probucol therapy in reducing the rate of restenosis after percutaneous transluminal coronary angioplasty (PTCA). BACKGROUND: Antioxidants have an inhibitory effect on smooth muscle cell growth in experiments in vitro and in vivo, which suggests a possible pharmacologic effect on restenosis after PTCA. METHODS: One hundred one patients were randomly assigned to receive 1,000 mg/day of probucol or control (no lipid-lowering) therapy 4 weeks before PTCA. After 4 weeks of premedication, both groups underwent PTCA. Probucol was continued until follow-up angiography 24 weeks after PTCA. Angiographic results were analyzed at a core laboratory by quantitative coronary angiography. RESULTS: Dilation was successful in 46 of 50 patients in the probucol group and 45 of 51 in the control group. At follow-up angiography 24 weeks after angioplasty, angiographic restenosis occurred in 9 (23%) of 40 patients in the probucol group and 22 (58%) of 38 in the control group (p = 0.001). Minimal lumen diameter was 1.49 +/- 0.75 mm (mean +/- SD) in the probucol group and 1.13 +/- 0.65 mm in the control group (p = 0.02). Percent diameter stenosis at follow-up angiography in the probucol group was significantly lower than that in the control group (43.9% vs. 56.4%, p = 0.009). The late loss was 0.37 +/- 0.69 mm in the probucol group and 0.60 +/- 0.62 mm in the control group (p = 0.13). The loss/gain ratio was 0.32 +/- 0.74 in the probucol group and 0.56 +/- 0.81 in the control group (p = 0.059). Net gain was greater in the probucol group than in the control group (0.77 +/- 0.70 vs. 0.48 +/- 0.59 mm, p = 0.053). CONCLUSIONS: Probucol administered beginning 4 weeks before PTCA appears to reduce restenosis rates.

Aged↗
PubMed1997

Reassessment of 79B actin gene expression in the abdomen of adult Drosophila melanogaster.

The expression pattern of the 79B actin gene in Drosophila melanogaster has been inferred previously by means of a reporter gene in which 79B actin promoter sequences drive the lacZ coding sequences. Although the 79B actin gene is expressed primarily in muscles of the thorax and first abdominal segment of the adults of both sexes, expression in the remaining abdominal segments appears limited to the male genital muscles and the male-specific Muscle of Lawrence (MOL). This reported abdominal expression pattern has been reassessed. By varying parameters of tissue preparation and lacZ reporter gene detection, expression of the 79B actin gene has been revealed in most dorsal abdominal longitudinal fibres and genital muscles of both females and males. These new results suggest that there are differences in the level of 79B actin gene expression among the various abdominal muscles of both sexes, and that abdominal expression is not limited primarily to male sex structures.

Abdomen↗
PubMed1997

Extended reproductive roles of the fruitless gene in Drosophila melanogaster revealed by behavioral analysis of new fru mutants.

The fruitless mutants fru3 and fru4 were assessed for sex-specific reproductive-behavioral phenotypes and compared to the previously reported fru mutants. Among the several behavioral anomalies exhibited by males expressing these relatively new mutations, some are unique. fru3 and fru4 males are less stimulated to court females than fru1 and fru2. No courtship pulse song is generated by either fru3 or fru4 males, even though they perform brief wing extensions. fru3 and fru4 males display significantly less chaining behavior than do fru1 males. The hierarchy of courtship responses by fru males directed toward females vs. males, when presented with both sexes simultaneously, is that fru1 males perform vigorous and indiscriminant courtship directed at either sex; fru4 males are similarly indiscriminant, but courtship levels were lower than fru1; fru2 males prefer females; fru3 males show a courtship bias toward males. fru3 and fru4 males essentially lack the Muscle of Lawrence (MOL). On several reproductive criteria, there was no difference between fru-variant females and fru+. The increases in phenotypic severity measured for the new mutants are discussed in the context of the emerging molecular genetics of fru and with regard to the gene's position within the sex-determination pathway.

Animals↗
PubMed1997

p53 gene mutations, and CYP1A1 and GSTM1 genotypes in pulmonary squamous cell carcinomas.

To investigate mechanisms causing p53 mutations in lung cancer cases, relations between p53 gene mutations and aetiological factors such as smoking history or family history of cancers cases. The contribution of genotypes related to carcinogen metabolism (CYP1A1 and GSTM1) was also analysed. p53 mutations were observed in 13 cases (37.5%). Seven (53.8%) of the 13 patients with p53 mutation compared with five (22.7%) of 22 patients without had a family history of cancer. However, there was no significant relation between p53 mutation or family history of cancer and CYP1A1 or GSTM1 genotypes. In conclusion, p53 mutation might be associated with the inherited characteristics that result in familial aggregation of lung cancer; however, this association was not explained by genotypes of enzymes related to carcinogen metabolisms.

Adult↗
PubMed1997

Fiber digestion and weight gain in guinea pigs fed diets containing different fiber sources.

The effects of different fiber sources on feed intake, weight gain and digestibility of fiber were examined in guinea-pigs fed pelleted diets containing alfalfa meal, oaten hay, beet pulp and commercial hay cubes mixed with a basal diet at ratios of 3:1 (75% in the diet), 1:1 (50%) and 1:3 (25%). The basal diet contained 50.0% corn, 4.1% wheat, 22.1% wheat flour and 17.7% corn gluten meal. Food intake increased as the amount of fiber source was increased, but not in the case of beet pulp. The most digestible fiber (ADF and NDF) was that of beet pulp. Apparent digestibility of dry matter decreased with increasing ratios of fiber source to the basal diet for all fiber sources, but fiber and crude protein digestibilities varied and depended not only on the ratio of fiber to the basal diet but also on the source of the fiber.

Animal Feed↗
PubMed1997

Trigonal splitting is a major complication of endoscopic trigonoplasty at 1-year followup.

PURPOSE: The long-term results of endoscopic trigonoplasty in patients with vesicoureteral reflux were investigated. MATERIALS AND METHODS: We performed endoscopic trigonoplasty in 28 patients with vesicoureteral reflux, including 6 girls 6 to 8 years old. Reflux was grade I in 14 reno-ureteral units, grade II in 15, grade III in 8, grade IV in 1 and grade V in 1. Median followup was 23 months. RESULTS: At a median of 3 months postoperatively vesicoureteral reflux was not apparent in 37 units (95%) and it was downgraded in 1 (3%). At a median of 12 months postoperatively 27 (79%) and 4 (12%) of the 34 ureters had cessation and downgrading, respectively. Of the 13 select patients who underwent cystoscopy 3 had retreating ureteral orifices and 5 had trigonal splitting 6 to 12 months postoperatively. Vesicoureteral reflux was demonstrated in 3 of the 5 patients (4 ureters) with trigonal splitting and in 1 (1 ureter) with retreating ureteral orifices. At a median of 24 months after surgery voiding cystography showed reflux in only 1 of 15 units. No postoperative upper urinary tract dilatation was noted at followup. CONCLUSIONS: Cessation rates of vesicoureteral reflux 12 months after endoscopic trigonoplasty were low with a high incidence of trigonal splitting. These unsatisfactory results mandate technical refinements to avoid trigonal splitting.

Adolescent↗
PubMed1997

Laparoscopic radical nephrectomy: the Nagoya experience.

PURPOSE: We evaluated the efficacy of laparoscopic radical nephrectomy for removing kidneys with small volume renal cell carcinoma. MATERIALS AND METHODS: 25 patients (19 men and 6 women, mean age 59) who had a kidney with small volume renal cell carcinoma (diameter less than 5 cm.), underwent laparoscopic radical nephrectomy. The kidney was dissected laparoscopically together with the adrenal gland, perirenal fatty tissue and Gerota's fascia. In 11 patients, we used the transperitoneal approach and in the remaining 14 we used the retroperitoneal approach, in which a working space is created by finger and balloon dissection. We maneuvered the kidney into the laparoscopy sack, which was then removed through an additional 5 to 6 cm. incision. RESULTS: All 25 kidneys were removed successfully. Mean operation time was 5.3 hours and mean estimated blood loss was 335 ml. There were 5 complications, including a patient who suffered an injury to the duodenum, which was treated by open duodenojejunostomy. Full convalescence occurred at an average 23 days. No metastatic disease, no local recurrence and no seeding at the port sites occurred during the followup of 7 to 49 months (mean, 22 months). CONCLUSIONS: Laparoscopic radical nephrectomy is recommended as a minimally invasive procedure for removing kidneys with small volume renal cell carcinoma.

Adult↗
PubMed1997

[Bilateral synchronous testicular seminomas: a case report and review of the Japanese literature].

A 39-year-old man was referred to our hospital with right testicular swelling. Ultrasonography and magnetic resonance imaging revealed bilateral, synchronous testicular tumors. Bilateral high inguinal orchiectomy was performed. Histological examination revealed anaplastic seminomas. Prophylactic radiation therapy was performed in the para-aortic and pelvic regions postoperatively, and no signs of metastasis have been found during the follow-up period of more than 5 months. Including the present case, 186 cases of bilateral testicular tumors reported in Japan are reviewed.

Adult↗
PubMed1996

Laparoscopic adrenalectomy via the retroperitoneal approach: first five cases.

Between February and November 1994, we performed laparoscopic retroperitoneal adrenalectomy in five patients with benign adrenal tumors to confirm the efficacy of this operation. Using digital dissection and a balloon, we created a working space in the retroperitoneal cavity before we dissected the adrenal gland and removed it under laparoscopic observation. The adrenal glands of all five patients were removed without any complications. The mean operative time was 3.4 hours, and the mean estimated blood loss was 148 mL. The average postoperative hospital stay was 10 days, and the average full recovery time was 19 days. We concluded that the retroperitoneal approach is an advantageous and safe procedure in the laparoscopic removal of the adrenal gland with benign tumor.

Adrenal Gland Diseases↗
PubMed1996

Anterior urethral diverticulum produced by Cowper's gland duct cyst.

A case of congenital urethral diverticulum is presented. The patient was a 16-year-old boy with the chief complaint of dribbling urine since he was 14 years old. A retrograde urethrogram revealed a diverticulum of the bulbar urethra, which had been produced by a cystic dilation of the Cowper's gland duct. The walls of the diverticulum were resected endoscopically.

Adolescent↗
PubMed1996

Immunosuppressive treatment of primary cadaveric renal transplant patients receiving kidneys from non-heart beating donors.

Since November 1982, 276 primary cadaveric kidney transplants have been performed using kidneys from non-heart beating donors. Between November 1982 and December 1986, 49 transplant patients were treated with cyclosporine and steroid immunosuppressive therapy (CSA regimen). Twenty-seven patients were treated with low dose cyclosporine (initial dosage, 4 mg/kg/day), steroid therapy, and a 21-day course of 500 mg/day antilymphocyte globulin (ALG 1 regimen) between January 1987 and December 1987. Seventy-nine patients were treated with low dose cyclosporine (initial dosage, 6 mg/ kg/day), steroid therapy, and a 14-day course of 1,000 mg/day antilymphocyte globulin (ALG 2 regimen) between January 1988 and June 1990, and 85 patients were treated with low dose cyclosporine (initial dosage, 6 mg/ kg/day), steroid therapy, and a 14-day course of 1,000 mg/day antilymphocyte globulin followed by 2 mg/kg/day mizoribine (ALG 3 regimen) between July 1990 and May 1995. Ten patients, who showed hypersensitivity to antilymphocyte globulin therapy, were treated with low dose cyclosporine, steroid therapy, and mizoribine. Finally, 26 patients were treated with FK506 and steroid therapy (FK506 regimen) between June 1990 and February 1992. Graft survival was 78% at 1 year, 69% at 3 years, 63% at 5 years, and 51% at 10 years in the CSA regimen group and 67% at 1 year, 52% at 3 years, and 48% at 5 years in the ALG 1 regimen group. It was 85% at 1 year, 70% at 3 years, and 62% at 5 years in the ALG 2 regimen group and 87% at 1 year and 67% at 3 years in the ALG 3 regimen group. In the FK506 regimen group, graft survival was 92% at 1 year and 80% at 3-5 years. Never-functioning grafts were observed in 3 CSA patients (6%), 1 ALG 1 patient (4%), 3 ALG 2 patients (4%), 3 ALG 3 patients (4%), and 1 FK506 patient (4%). These results indicate that low dose cyclosporine (initial dosage, 6 mg/kg/day), steroid therapy, and a 14 day course of antilymphocyte globulin therapy is beneficial for cadaveric renal transplant patients receiving kidneys from non-heart beating donors; FK506 and steroid therapy might be more effective than cyclosporine based immunosuppressive therapies even in such patients.

Adolescent↗
PubMed1996

Relationship between the 13C-NMR chemical shift and the carcinogenic activity of benz[a]anthracenes.

A thorough NMR spectroscopic investigation was made on 7,12-dimethylbenz[a]anthracene (1) and the 1H- and 13C-NMR spectra were completely assigned. We compared the 13C-NMR chemical shifts (delta) of three benz[a]anthracenes, including compound 1, whose carcinogenicities vary largely, and investigated the relationship of the delta and carcinogenicity. It was found that the delta values at the C1, C2, and C6 positions differed significantly between the carcinogenic and noncarcinogenic compounds.

Benz(a)Anthracenes↗
PubMed1996

Effect of chronic high protein intake on magnesium, calcium, and phosphorus balance in growing cats.

The effects of high protein feeding on food and water intake, and the retention and urinary excretion of macrominerals (magnesium (Mg), phosphorus (P), and calcium (Ca)) were examined in growing cats. Seven female cats aged 4 months were fed diets containing 55% crude protein (n = 4) or 29% crude protein (n = 3) for 12 months on an ad libitum basis. Mineral balances were determined at 0.5, 2, 6, 10, and 12 months of feeding. The higher protein intake stimulated daily water intake and urine excretion throughout the study, although daily food intake was not affected by dietary protein levels. The urinary Mg concentration was decreased by the high protein intake, resulting from both increased urine volume and reduced excretion of urinary Mg. In contrast, the concentration and daily excretion of urinary P were increased by the high protein intake. The protein-induced increase in urinary P would not necessarily imply the increased excretion of PO4(3-), the anion responsible for struvite crystallization, because the dissociation of phosphate depends on urinary pH. Urinary Ca excretion was not affected by the dietary protein levels, but the high protein intake caused less retention of P and Ca as a result of enhanced urinary P excretion and lowered Ca absorption. The possibility of high protein feeding for the prevention of struvite crystallization in growing cats is discussed.

Animals↗
PubMed1996

Evaluation of cardiac sympathetic nervous function by 123I-metaiodobenzylguanidine scintigraphy in insulin-treated non-insulin dependent diabetics with hypoglycemia unawareness.

The association between the lack of adrenergic symptoms during hypoglycemia and myocardial 123I-metaiodobenzylguanidine (MIBG) accumulation was investigated in 12 insulin-treated non-insulin-dependent diabetes mellitus (NIDDM) patients who had no evidence of heart disease. These patients were divided into 2 groups according to the presence (group A) or absence (group B) of adrenergic symptoms during hypoglycemia. Autonomic function tests revealed significantly severe autonomic dysfunction in group B compared to that in group A. Insulin infusion test indicated no significant difference in the catecholamine response between the two groups. 123I-MIBG scintigraphy showed that the heart/mediastinum ratio of MIBG uptake was significantly lower, and scintigraphic defect was greater in group B than in group A. There were no significant differences in the washout rate between the two groups. These results suggested that the lack of adrenergic symptoms during hypoglycemia may be associated with cardiac sympathetic nervous dysfunction in insulin-treated NIDDM patients, and this dysfunction is mainly due to cardiac sympathetic denervation.

3-Iodobenzylguanidine↗