Biomedical subjects

G Watanabe

Publications and source records attributed to G Watanabe.

At least 235 records · Page 13Linked to original sources

PubMed1996

Protein kinase N (PKN) and PKN-related protein rhophilin as targets of small GTPase Rho.

The Rho guanosine 5'-triphosphatase (GTPase) cycles between the active guanosine triphosphate (GTP)-bound form and the inactive guanosine diphosphate-bound form and regulates cell adhesion and cytokinesis, but how it exerts these actions is unknown. The yeast two-hybrid system was used to clone a complementary DNA for a protein (designated Rhophilin) that specifically bound to GTP-Rho. The Rho-binding domain of this protein has 40 percent identity with a putative regulatory domain of a protein kinase, PKN. PKN itself bound to GTP-Rho and was activated by this binding both in vitro and in vivo. This study indicates that a serine-threonine protein kinase is a Rho effector and presents an amino acid sequence motif for binding to GTP-Rho that may be shared by a family of Rho target proteins.

Adaptor Proteins, Signal Transducing↗

PubMed1996

Prognostic value of monolayer culture patterning in primary cell culture of oesophageal cancer.

The growth of primary cell cultures of oesophageal cancer was compared with the clinical outcome of patients from whom the cancers were taken. Ninety-three patients underwent curative resection, with no operative deaths, and were divided into three groups according to the monolayer culture pattern of the primary cell culture: culture from 43 patients (46 per cent) grew no malignant cells (group 1), 21 (23 per cent) produced monolayer epithelial growth (group 2) and the rest (from 29 patients) established cell lines (group 3). The 5-year survival rate of patients in group 2 (29 per cent) and group 3 (23 per cent) was significantly lower (P < 0.005) than that of those in group 1 (51 per cent). Monolayer epithelial growth potential is a significant prognostic factor in patients with oesophageal cancer.

Adult↗

PubMed1996

A new technique of reinforced sternal closure.

A technique of reinforced sternal closure with stainless steel Kirschner wires is described. This technique is useful for patients with a fractured or friable sternum, or pectus excavatum.

Bone Wires↗

PubMed1996

High concentrations of immunoreactive inhibin in the plasma of mares and fetal gonads during the second half of pregnancy.

Plasma concentrations of immunoreactive (ir)-inhibin were measured in seven pregnant mares from around Day 140 of gestation to Day 2 after parturition using a heterologous bovine-based radioimmunoassay (RIA). Concentrations of luteinizing hormone (LH), follicle-stimulating hormone (FSH), oestradiol-17 beta, progesterone and relaxin were also measured in the same samples. A marked increase in plasma concentrations of ir-inhibin, FSH and LH occurred between Day 220 and Day 300 of gestation but the concentrations of all three hormones returned to baseline by about Day 320 (three weeks before parturition). In contrast, circulating concentrations of the three placental hormones, oestradiol-17 beta, progesterone and relaxin, increased during the final weeks of pregnancy and then decreased markedly to basal values within two days of parturition. There was a positive correlation between circulating concentrations of ir-inhibin and FSH (r = 0.75, P < 0.01) rather than the expected negative correlation. ir-inhibin was not detected in homogenates obtained at Day 190 of pregnancy and form term placenta, but high concentrations of ir-inhibin were present in homogenates of fetal and newborn gonads. Despite the high concentrations of ir-inhibin in these homogenates, they failed to exert any suppressive bioactivity on FSH secretion by rat pituitary cells cultured in vitro. Furthermore, immunohistochemical staining revealed the presence of inhibin in the interstitial cells of equine fetal gonads at Day 190 of gestation. These findings demonstrate for the first time that high concentrations of ir-inhibin, LH and FSH are secreted into the peripheral circulation of the mare during the second half of pregnancy. However, ir-inhibin present in the plasma of pregnant mares appears to be biologically inactive. This hormone is not presumed to be of placental origin but it is proposed that either the enlarged fetal gonads or the maternal ovaries, or both of these organs, may be a source of inhibin in response to the coincident increase in circulating concentrations of LH and FSH.

Animals↗

PubMed1996

Roles of inhibin and estradiol in the regulation of follicle-stimulating hormone and luteinizing hormone secretion during the estrous cycle of the rat.

The relative contributions of inhibin and estradiol in the regulation of FSH and LH secretion were examined at various stages of the estrous cycle in the rat. At 1100 h on metestrus, diestrus, or estrus or at 0500 h on proestrus, rats were ovariectomized or given an injection of normal goat serum, antiserum to inhibin (inhibin-AS), antiserum to estradiol (estradiol-AS), or both antisera to examine the role of gonadal hormones in the regulation of tonic gonadotropin secretion. Plasma samples were collected before and at 6, 12, and 24 h after the treatments. Further, to examine the effects of the treatments on preovulatory gonadotropin surges, the five treatments described were carried out at 0500 h on proestrus and blood samples were collected from 1100 h to 2000 h on the same day at 1.5-h intervals. There was a significant rise in the concentration of plasma FSH after injection of inhibin-AS as well as after ovariectomy on each day of the estrous cycle. These treatments, however, had less effect on estrous FSH secretion. The rise in FSH was greater with immunoneutralization against both inhibin and estradiol than with immunoneutralization against inhibin alone on diestrus and proestrus. Basal levels of LH were increased at all stages of the cycle through immunoneutralization against inhibin and were also increased through immunoneutralization against estradiol except at estrus. Especially on diestrus, a remarkable increase in LH secretion was induced at 6 h after immunoneutralization against both inhibin and estradiol (1449.3 +/- 100.3% vs. control). The magnitude of the LH surge increased in inhibin-immunized rats, decreased in estradiol-immunized or ovariectomized rats, and remained at normal levels after injections of both antisera. The magnitude of the primary FSH surge increased very markedly in the inhibin-immunized group and decreased in the estradiol-immunized group. These results suggest that both estradiol and inhibin play a role in the regulation of LH secretion and that inhibin is a major regulator of FSH secretion during the estrous cycle of the rat. Furthermore, it is suggested that one or more extragonadal factors suppress estrous FSH secretion.

Animals↗

PubMed1996

Reduced cyclin D1 expression in the cerebella of nutritionally deprived rats correlates with developmental delay and decreased cellular DNA synthesis.

Nutritional deprivation in the early postnatal period severely inhibits cerebellar growth and development, which is related in part to reduced levels of growth factors. Cyclin D1 encodes a growth factor-inducible regulatory subunit of a serine/thereonine kinase that is capable of phosphorylating the tumor suppressor pRB, thereby allowing normal progression through the G1 phase of the cell-cycle. Because the abundance of cyclin D1 is rate limiting in this progression, we examined the regulation of cyclin D1 expression in vivo, using a model of nutritional deprivation. Cyclin D1 expression in cerebella of fed control rats was detected in the external granular layer and was associated with cellular proliferation within this layer. Nutritional deprivation of rats reduced cerebellar weight, as well as the thickness of the molecular layer that largely consists of cells migrating from the external granular layer. Refeeding partially restored cerebellar weight, molecular layer thickness and increased external granular layer cyclin D1 immunostaining. Since nutritional deprivation is accompanied by lower levels of circulating insulin-like growth factor-I (IGF-I), we determined whether IGF-I directly stimulated the cyclin D1 promoter. The human cyclin D1 promoter linked to the luciferase reporter gene was stably integrated into PC12 cells. IGF-I stimulated cyclin D1 promoter activity 4- to 6-fold at 6 hours (h). These findings are consistent with the notion that nutritional deprivation may affect proliferative growth by altering expression of cyclin D1 in the germinal cell layer and that regulation of cyclin D1 expression by growth factors may contribute to normal neonatal cerebellar development. The reduction in cyclin D1 expression as cells differentiate in the cerebellum is consistent with a potential role for cyclin D1 in this process.

Animals↗

PubMed1996

Case report: gastrointestinal bleeding from a hepatocellular carcinoma invading the transverse colon.

A 72-year-old woman with cirrhosis of the liver was treated repeatedly by transcatheter arterial embolization for multifocal hepatocellular carcinomas. She developed gastrointestinal bleeding secondary to direct invasion of the wall of the transverse colon. The diagnosis was made pre-operatively by colonoscopy and the patient was treated successfully. This rare complication of hepatocellular carcinoma was due to the protrusive type of growth exhibited by this tumour and may have been affected by the transcatheter arterial embolization.

Aged↗

PubMed1996

Increase in insulin release from rat pancreatic islets by quinolone antibiotics.

1. The present study was undertaken to elucidate the mechanism(s) of hypoglycaemia caused by quinolone antibiotics. We investigated the effects of various quinolone antibiotics on insulin release in rat pancreatic islets. 2. At a non-stimulatory concentration of 3 mM glucose, lomefloxacin (LFLX) or sparfloxacin at 1 mM and pipemidic acid (0.1-1 mM) induced slight insulin release but tosufloxacin or enoxacin up to 100 microM did not. 3. At the stimulatory concentration of 10 mM glucose, all quinolones augmented insulin release in a dose-dependent manner. LFLX (100 microM) shifted the dose-response curve of glucose-induced insulin release to the left without altering the maximal response. 4. At 10 mM glucose, LFLX (100 microM) increased insulin release augmented by forskolin (5 microM) or 12-O-tetradecanoyl phorbol-13-acetate (100 nM) but not by raising the K+ concentration from 6 to 25 mM. 5. Verapamil (50 microM) or diazoxide (50-400 microM) antagonized the insulinotropic effect of LFLX. 6. These data suggest that quinolone antibiotics may cause hypoglycaemia by increasing insulin release via blockade of ATP-sensitive K+ channels.

4-Quinolones↗

PubMed1996

A new contact probe for intraoperative laser ablation.

Several clinical factors decrease the accuracy of intraoperative laser ablation. The distance to the target, the irradiation angle, and the media are reported among these factors. We developed a new laser probe to resolve these problems. This probe has a hollow conical tube with a tip covered by a thin film. Zero-degree centigrade saline was fed into this probe. Results from using the new probe were compared with those from the conventional noncontact irradiation method with cooling by sprinkled cooling water. In beating canine hearts, ventricles were irradiated with neodymium:yttrium aluminum garnet (Nd:YAG) lasers at 50-200 J/mm2. There was no difference in the mean volume of irradiated tissue between the new and the noncontact method. However, the distribution of volume values in the new method was smaller than that in the noncontact method (P < 0.05). In conclusion, results obtained indicate that this new probe could perform more accurate intraoperative ablation than the conventional method. Problems of stabilizing the distance to the target, the irradiation angle, and the media were resolved.

Animals↗

PubMed1996

Stimulation of the P-450 side chain cleavage enzyme (CYP11A1) promoter through ras- and Ets-2-signaling pathways.

Expression of the ovine P-450 side-chain cleavage enzyme gene (CYP11A1) is stimulated by epidermal growth factor (EGF) through a pathway that involves c-Jun in JEG-3 placental cells. Growth factor signaling involves ras-dependent and ras-independent signaling pathways, which in turn regulate gene transcription through related but distinct mitogen-activated protein kinase pathways (MAPKs) including the extracellular signal-regulated kinases (ERKs) and the stress-activated protein kinases (SAPKs). We investigated the intracellular signaling pathways governing EGF induction of the CYP11A1 promoter. EGF stimulation of the CYP11A1 promoter (4-fold) was reduced 60% by a dominant negative mutant of ras (N17), and 30-40% by antisense ras. EGF induced both ERK and SAPK activity in JEG-3 cells. EGF-induced CYP11A1 promoter activity was reduced 60% by the MEK1 inhibitor PD098059 and 50% by a dominant negative mutant of the ERK-specific regulator MEK1. In contrast, dominant negative mutants of the SAPK-specific activator, SEK1, induced a further increase in EGF-induced CYP11A1 promoter activity. Constitutively active mutants of ras (V12 or L61) increased CYP11A1 promoter activity 6- to 8-fold. Deletion of the EGF response element (EGF-RE) between -92 and -77 bp reduced ras induction by 60%; however, a residual 3-fold induction remained through the proximal -77 bp. Mutation of the EGF-RE AP-1-like sequence in the context of the native promoter reduced CYP11A1 promoter activation by ras 60%. The EGF-RE sequence was sufficient for 6-fold activation by ras in the context of an heterologous thymidine kinase promoter. Candidate transcription factor targets (c-Jun, c-Ets-2) for the ras-signaling cascade were examined for their effects on CYP11A1 promoter activity. Overexpression of c-Jun induced the CYP11A1 promoter through the EGF-RE; however, c-Ets-2 activation of the CYP11A1 promoter (12-fold) required the proximal ras-responsive promoter sequences that are distinct from the EGF/MEK/c-Jun-responsive element. Induction of the CYP11A1 promoter by EGF involves a ras/MEK1/AP-1-dependent pathway that is distinct from induction by ras/c-Ets-2.

Calcium-Calmodulin-Dependent Protein Kinases↗

PubMed1996

Left ventricular hypertrophy in mild essential hypertension. Its progression, prediction and treatment strategy.

Since the pathogenesis of left ventricular hypertrophy (LVH) in hypertension is thought to be multifactorial, the antihypertensive strategy also has to be multifaceted. Diagnosis of LVH is more reliable than ever with echocardiography either of the M-mode or 2D method. Diagnostic criteria have already been proposed by Ganau et al who classified LV morphology into 4 different sectors based on the standard values of left ventricular mass index (LVMI) and relative wall thickness in diastole (RWTd); normal, concentric remodeling, concentric hypertrophy and eccentric hypertrophy. The concentric hypertrophy pattern is the most risky with regard to prognosis. Therefore, its detection and prediction for further progression have to be conducted with relatively easy routine work-up procedures such as echocardiography and maximal exercise testing. The prediction of LVH progression has already been proposed based on several studies conducted in patients with borderline or mild hypertension. The following two predictors were defined as LVMI > 124 g/m2 and peak Ps at maximal exercise testing > 200 mmHg. Therefore, the patient who meets these criteria has to be treated with medications that are appropriately selected on an individualized basis. Both hyperinsulinemia and insulin resistance are thought to be involved in the initiation, promotion and potentiation of remodeling of the LV in hypertension. Physical fitness also seems to be decreased in a parallel manner. Selection of the most appropriate drug for a given patient has to be individually determined based on the risks that have to be corrected. Finally, arteriosclerosis, which is almost always initiated and progresses in concert with hypertension, must also be targeted with regard to such prognostic aspects as cardiovascular morbidity and mortality. Arteriosclerosis is pathogenetically independent from hypertension, but usually behaves in concert with it. Selection of medication must be focussed on an individualized basis not only for LVH, but also for improvement in arterial elasticity. Further clinical research is still needed to provide more reasonable approaches to patients with hypertension.

Angiotensin II↗

PubMed1996

Induction of superovulation by immunoneutralization of endogenous inhibin through the increase in the secretion of follicle-stimulating hormone in the cyclic golden hamster.

The present study was conducted to study the effect of immunoneutralization against endogenous inhibin on FSH, LH, oestradiol-17 beta and progesterone secretion and to investigate the effect of removal of endogenous inhibin on subsequent follicular development in the hamster. After treatment with anti-inhibin serum (inhibin-AS) at 1100 h on day 2 of the oestrous cycle (day 1 = day of ovulation), a marked increase in plasma levels of FSH and a slight increase in plasma levels of LH were noted and pituitary contents of FSH, but not LH, were also increased. In the group treated with inhibin-AS, superovulation occurred on day 1 of the following cycle. Plasma levels of oestradiol-17 beta markedly increased with the increase in the number of ovulations induced by human chorionic gonadotrophin (hCG) as compared with those in control animals. In the second cycle, plasma concentrations and pituitary contents of FSH in the animals given 200 microliters inhibin-AS still showed high values as compared with those in the animals treated with control serum, although superovulation did not occur on day 1 of the third cycle. Plasma concentrations and pituitary contents of LH in the hamster given 200 microliters inhibin-AS tended to decrease as compared with those in control animals during the second cycle. Plasma concentrations of oestradiol-17 beta in the animals treated with 200 microliters inhibin-AS changed in a similar way to controls. A marked increase in plasma concentrations of progesterone was noted on days 1 and 2 of the second cycle in the group receiving inhibin-AS. The twice daily injection of 1 IU hCG during the second cycle to the animals given 200 microliters inhibin-AS induced superovulation on day 1 of the third cycle. These results indicate that circulating inhibin may be an important indicator of the number of developing follicles and may maintain the species-specific number of developing follicles through suppression of FSH secretion in the cyclic hamster. They also suggest that high levels of inhibin slightly suppress plasma levels of LH, indicating that plasma LH may also regulate follicular development in the cyclic hamster.

Animals↗

PubMed1996

[Prospective randomized trial comparing 1/2 FAM (5-fluorouracil (5-FU) + adriamycin + mitomycin C) versus palliative therapy for the treatment of unresectable pancreatic and biliary tract carcinomas (the 2nd trial in non-resectable patients). Japanese Study Group of Surgical Adjuvant Therapy for Carcinomas of the Pancreas and Biliary Tract].

The efficacy of 1/2 FAM, which consists of 5-fluorouracil (5-FU), adriamycin (ADM) and mitomycin C (MMC), was compared with that of palliative treatment in patients with unresectable pancreatic and biliary tract carcinomas in a multicenter randomized trial. The patients assigned to 1/2 FAM group were treated with 5-FU 200 mg/m2/day IV, ADM 15 mg/m2/day IV and MMC 5 mg/m2/day IV. These 3 drugs were given concurrently as the initial dose within a week after palliative operation, and this regimen was repeated for at least 2 whole courses, at 4-week intervals before the next course of therapy. Those randomized to the control group were subjected to palliative treatment alone. Completely eligible for analysis were 42 cases of the 1/2 FAM group and 41 of the control group. There was no significant difference between the groups with respect to the overall and differentiated survival times according to the tumor sites and the clinical efficacy. As for the duration of 50% inhibition of tumor progression, a significantly better outcome was obtained in 1/2 FAM group. Tumor progression was most significantly inhibited in patients with gallbladder carcinoma. In 1/2 FAM group, tumor reduction was achieved in 1 CR and 2 PR patients. The most frequent adverse reaction was gastrointestinal manifestations, along with diarrhea and alopecia. 1/2 FAM did not contribute to the life prolongation, but inhibited the tumor progression for a significantly longer duration and, to a lesser extent, reduced the tumor size in unresectable pancreatic and biliary tract carcinomas. This regimen is suggested to be useful particularly in the treatment of the latter carcinoma.

Adult↗

PubMed1996

[Emergency coronary artery bypass grafting under cardiopulmonary resuscitation: a successful case report].

A successful case of emergency coronary artery bypass grafting for a 69-year-old man with refractory cardiac arrest due to impending myocardial infarction was reported. Preoperative full resuscitation including external cardiac massage was required. The duration from cardiac arrest to cardiopulmonary bypass establishment was 24 minutes and aortic cross clamping time was 29 minutes for triple bypass grafting to the right, left circumflex and left anterior descending coronary artery.

Aged↗

PubMed1996

[On the origin of extra bands at MCT118 typing].

In order to probe the origin of extra bands that appear frequently in MCT118 typing, we examined the extra bands by Dual PCR, Asymmetric PCR and PCR-SSCP method. It is conceivable that two extra bands of 16-18 type are DNA heteroduplexes that result from 16 and 18 allele bands at mutual cross-annealing. The extra bands can easily take the higher-order structure due to a non-complimentary sequence of bases. Consequently, the distances that extra bands travel in electrophoresis depend on a gel composition. Because the extra bands can be distinguished from the original allele bands by electrophoresis using different gel composition, it will not become an obstacle at the typing.

Chromosomes, Human, Pair 1↗

PubMed1996

[An alpha-1-antitrypsin deficiency allele PI*Siiyama found in a disputed paternity case].

An incompatible mother-child pair was found in an alpha-1-antitrypsin (PI) system in a disputed paternity case. By the isoelectric focusing, the PI type of the mother and the child were confirmed PI M1 and PI M2, respectively. Testing of many other genetic markers could not exclude her motherhood. Therefore, the mother and the child were inferred to be heterozygous carriers of a PI deficiency allele. PCR-SSCP analysis of exon 2 suggested that the PI types of the mother and the child are heterozygous M1-Siiyama and M2-Siiyama, respectively.

Alleles↗

PubMed1996

A potential role for cell cycle control proteins in regulation of the cyclic adenosine 5'-monophosphate-responsive glycoprotein hormone alpha subunit gene.

The production of chorionic gonadotropin is coupled to the differentiation of the placenta. Expression of the alpha subunit of chorionic gonadotropin [glycoprotein hormone alpha (GPH-alpha)] is also known to be stimulated by treatment of placental cells with either cAMP or DNA synthesis inhibitors. Given these features, we used adenovirus E1A as a molecular probe to investigate a potential role for cell cycle regulatory proteins and kinases in the regulation of GPH-alpha expression. The E1A protein contains well-characterized domains that interact with a variety of cell cycle regulatory proteins. The E1A conserved regions 1 and 2 bind proteins that regulate cell cycle progression, including pRB, p107, and p130. The amino-terminal region of E1A binds several high molecular weight proteins and inhibits the transcriptional coactivator function of p300 and the homologous cAMP response element (CRE)-binding protein. We found that coexpression of E1A13S activated the GPH-alpha promoter, whereas E1A12S caused marked repression. Deletion mutants and point mutations revealed that repression by E1A12S required the CRE of the GPH-alpha promoter. Several distinct domains in E1A12S were necessary for maximal repression. A mutation of the E1A amino terminus (RG2), which inhibits binding of p300 and related high molecular weight proteins, reduced 12S repression by 40%. Mutation of the pocket protein-binding domains reduced repression by 20%, and mutations of both domains reduced repression by 80%. Overexpression of p300 or the pocket proteins (pRB, p130, and p107) induced GPH-alpha promoter activity 2-4-fold. Because the E1A amino terminus and pocket protein-binding domains together induce p34cdc2 kinase activity, the effect of p34cdc2 kinase expression on GPH-alpha activity was also assessed. Coexpression of p34cdc2 kinase or the activating p34cdc2 kinase mutant (T14AY15F) inhibited GPH-alpha promoter activity and acted through the CRE. We conclude that the GPH-alpha gene CRE is subject to regulation by cell cycle regulatory kinases and proteins.

Adenoviridae↗

PubMed1996

[The changes in lymphocytes subpopulations of a patient with postoperative chylothorax].

A case of 64-year-old male who developed chylorrhea at 2 days post coronary artery by-pass grafting, is reported. He was managed conservatively for 3 weeks. But chylothorax was not improved, he was treated operatively. Analysis of his lymphocyte subpopulations in peripheral blood were performed during the course of chylothorax. Lymphocytepenia became apparent and subpopulation of T cell were decreased gradually. The subpopulation of CD 4(+) cell decreased, while the subpopulation of CD 8(+) increased. The CD 4(+) cell/CD 8(+) cell ratio decreased consequently till 7th day after 2nd operation. Although the replenishment of nutritional deficiencies using TPN allows prolonged conservative management for chylothorax patient, the deterioration in cellular immunocompetence can not be prevented at present. It is necessary to take great care about infection for chylothorax patient.

CD4-CD8 Ratio↗