Search PubMed⌕ Search

Biomedical subjects

M Kawaguchi

Publications and source records attributed to M Kawaguchi.

At least 109 records · Page 6Linked to original sources
PubMed1999

Intravenous injections of nicotine decrease the pulsatile secretion of LH by inhibiting the gonadotropin-releasing hormone (GnRH) pulse generator activity in female rats.

Whether nicotine inhibits the electrical activity of the gonadotropin-releasing hormone (GnRH) pulse generator to suppress pulsatile LH secretion, and whether this suppression of LH secretion by nicotine is mediated by opioid neurons, were studied in ovariectomized rats by examining changes in LH secretion and the multiunit activity (MUA) of the medial basal hypothalamus. Intravenous (i.v.) injection of nicotine (nicotine bitartrate, 100 micrograms) significantly increased the interval between characteristic increases (volleys) in MUA and LH pulses. This inhibitory effect of nicotine on the GnRH pulse generator activity was not blocked by the prior injection of an opiate receptor antagonist naloxone (naloxone hydrochlolide, 2 mg/kg bw), which was effective in significantly decreasing the interval between MUA volleys. The results suggest that nicotine alters the activity of the GnRH pulse generator, and that cholinergic neurons appear to be directly involved in suppressing pulsatile secretion of LH.

Animals↗
PubMed1999

Detection of lipid peroxidation catalyzed by chelated iron and measurement of antioxidant activity in wine by a chemiluminescence analyzer.

We measured directly the reactive oxygen generated from a peroxide-free reaction system when a ferrous complex with nitrilotriacetic acid was oxidized to the ferric complex. Further, it was observed by a measurement of chemiluminescence that peroxidation of a lipid substrate added in the system is initiated by the Fe(3+)-type of reactive oxygen generated. Antioxidant activity can be estimated by contrasting the reaction rates of lipid peroxidation between the systems with and without a putative antioxidant sample. By this method, the antioxidant activity, expressed as catechin equivalent, of red wines for linoleic acid peroxidation was shown to be higher than those of rosé and white wines (189-311, 84, and 37 microM for red, rosé, and white wines, respectively) because of a higher concentration of polyphenols such as flavanol and anthocyanin in red wines. The chemiluminescence measurement would be a promising method for evaluating the antioxidant potential because of its highly specific and sensitive detection of the hydroperoxide and for monitoring in situ peroxidation reaction.

Anthocyanins↗
PubMed1999

Functional MR imaging with venography for neurosurgical identification of the central sulcus.

We evaluated the applicability of functional MR imaging overlaid onto brain images superimposed venography for neurosurgical identification of the central sulcus. In 20 volunteers and 12 patients with brain tumors located around the sensorimotor cortex, gradient echo and large flip angle functional MR image was performed to allow visualization of flow effect and susceptibility related changes in relative large vein by motor hand task. Functional MR image acquired was overlaid on 3D anatomical image with 3D venography. Based on the 3D mapping, intra-operative cortical somatosensory evoked potentials (SEPs) were recorded. The significant activation area obtained from functional MR imaging was projected on an ascending cortical vein in 16 volunteers (80%) and 10 patients (83%). Comparing the anatomical activation map with visual inspection of the exposed cortical surface made it easy to identify the activation area during surgery. The cortical veins in 9 of 10 were validated as a central vein by intra-operative cortical recording of SEPs. Combination of functional MR imaging overlaid onto 3D anatomical image with venography and intra-operative SEPs permitted rapid and accurate localization of the central sulcus during surgery.

Adult↗
PubMed1999

Intra-operative optical method using intrinsic signals for localization of sensorimotor area in patients with brain tumor.

The purpose of this study is intra-operatively to localize the sensorimotor area by intrinsic optical method detecting the changes in regional cerebral blood flow (rCBF) and cortical temperature following neuronal activity during median nerve stimulation. In 18 patients with brain tumors located around the sensorimotor cortex, cortical recording of somatosensory evoked potentials (SEPs) was performed and localized changes in rCBF during median nerve stimulation were measured by a laser-Doppler flowmeter on the locations of SEPs and around the activation area obtained by functional magnetic resonance imaging (fMRI). In two patients, cortical thermomapping was also performed during median nerve stimulation. In fMRI study, the significant activation area of sensorimotor could be obtained in 17 of 18 patients. In cortical recording of SEPs, the polarity reversal of N20 and P20 was observed in 14 of the 18 patients. In 9 of the 14 patients in whom SEPs could be recorded, the localized changes in rCBF, corresponding to the stimulation, were detected in the N20 area. In 2 of the 4 patients in whom N20 could not be recorded successfully, the localized changes in rCBF could be detected. The increase in rCBF during the stimulation was 18.3% +/- 5.3% (mean +/- SD, n = 11). Thermomapping could demonstrate the localized area, where the increase in rCBF was also detected, by observation of the changes in cortical temperature during the stimulation. The intra-operative intrinsic optical method detecting rCBF and cortical temperature in combination with recording of SEPs may be considered useful for brain functional localization related to neurosurgical disorders.

Aged↗
PubMed1999

The effects of prostaglandin E1 on intraoperative temperature changes and the incidence of postoperative shivering during deliberate mild hypothermia for neurosurgical procedures.

UNLABELLED: We investigated the effects of i.v. prostaglandin E1 (PGE1) on intraoperative changes of core temperature and the incidence of postoperative shivering in neurosurgical patients undergoing deliberate mild hypothermia. Eighty-three patients were randomly assigned to one of three groups: patients in the control group did not receive PGE1, whereas patients in the PG20 group and PG50 group received PGE1 at a dose of 0.02 and 0.05 microg x kg(-1) x min(-1), respectively. The administration of PGE1 was started just after the induction of anesthesia and continued until the end of anesthesia. Anesthesia was maintained with nitrous oxide in oxygen, sevoflurane, and fentanyl. After the induction of anesthesia, patients were cooled using a water blanket and a convective device blanket. Tympanic membrane temperature was maintained at 34.5 degrees C. During surgical wound closure, patients were rewarmed. Intraoperative changes in tympanic membrane and skin temperatures and the incidence of postoperative shivering were compared among groups. Demographic and intraoperative variables were similar among groups. There were no significant differences in tympanic temperatures among groups at each point during the operation. Skin temperature 30 min after rewarming and just after tracheal extubation was significantly lower in the PG20 group than in the PG50 group. Postoperative shivering was more frequent in the PG20 group (43%) than in the control (13%) and PG50 (17%) groups. These results suggest that the intraoperative administration of PGE1 does not affect changes in core temperature during deliberate mild hypothermia and that PGE1 at a dose of 0.02 microg x kg(-1) x min(-1) may increase the occurrence of postoperative shivering. IMPLICATIONS: Deliberate mild hypothermia has been proposed as a means of providing cerebral protection during neurosurgical procedures. Vasodilating drugs may be used during deliberate mild hypothermia to maintain peripheral circulation and to enhance the cooling and rewarming rate. In the present study, however, we found no benefit from i.v. prostaglandin E1 administration during deliberate mild hypothermia in neurosurgical patients.

Alprostadil↗
PubMed1999

The correlation of the metastatic ability with keratin expression in cultured murine melanoma cell lines, B16-F1 and-F10.

Keratin is an intermediate filament that is a major structural protein of epithelial cells. Until now, the expression of keratin in melanoma cells has not been well understood. Recently, it has been reported that keratin expression is correlated with invasive and metastatic behavior in a variety of cell types. We report keratin expression in cultured murine melanoma cell lines B16-F1 (low incidence of lung colonization) and F10 (high incidence of lung colonization) using an aqueous solution (10 mM Tris-HCl (pH 7.4)/10 mM EDTA/phenylmethyl sulphonyl fluoride (PMSF, 10 micrograms/ml). By comparing these two cell lines, we investigated whether differences in keratin expression can influence the metastatic ability of tumor cell lines in vitro. However, no remarkable differences in keratin expression were found in these cell lines.

Animals↗
PubMed1999

Acute generalized exanthematous pustulosis induced by salazosulfapyridine in a patient with ulcerative colitis.

We report a case of acute generalized exanthematous pustulosis (AGEP) induced by salazosulfapyridine in a patient with ulcerative colitis. A 26-year-old Japanese man, who had been receiving medical attention for ulcerative colitis for one year, presented with diffuse erythema and pustules on his face and trunk, malaise, and fever up to 39 degrees C one day after the administration of salazosulfapyridine. A skin biopsy specimen disclosed intracorneal pustule composed of neutrophils and lymphohistiocytic infiltrate in the dermis. A drug lymphocyte stimulation test for salazoslufapyridine was positive, but the patch test was negative. Immunological mechanisms are suggested in the pathogenesis of psoriasis and ulcerative colitis. We suspect that a similar immunological pathway played a role in the pathogenesis of AGEP appearing in psoriasis and ulcerative colitis.

Adult↗
PubMed1999

Antihypertensive effect of insulin via nitric oxide production in the Zucker diabetic fatty rat, an animal model for non-insulin-dependent diabetes mellitus.

It has been reported that insulin treatment improves hypertension in patients with diabetes mellitus. The mechanisms of the antihypertensive effect of insulin, however, remain to be fully elucidated. In the present study, we investigated a possible involvement of nitric oxide (NO) in insulin-induced reduction of blood pressure using the Zucker diabetic fatty (ZDF) rat, an animal model of non-insulin-dependent diabetes mellitus. The animals were divided into three groups and treated for 4 weeks with daily subcutaneous injections of insulin (25U/kg body weight) with or without oral administration of l-nitro-arginine methyl ester (L-NAME, 50mg/kg/day body weight as drinking water), an inhibitor of NO synthase (NOS). Saline solution was injected subcutaneously in the control groups. During the experimental period, body weight gain was greater in the insulin-treated groups than in the control groups whereas water intake was considerably decreased in the insulin-treated groups. Insulin treatment resulted in a decrease in plasma glucose and blood pressure, and an increase in both NO metabolites (NOx) in the plasma and NOS activity in the aorta tissue. L-NAME treatment blunted not only the antihypertensive effect of insulin but also the changes in NOx and NOS activity. These findings suggest that insulin reduces blood pressure in the ZDF rat by stimulating NOS activation and NO production.

Animals↗
PubMed1999

Primary hypomagnesemia caused by isolated magnesium malabsorption: atypical case in adult.

Isolated magnesium malabsorption is a rare disorder, which bas been described in no more than 30 patients worldwide. Patients with this disorder typically present with convulsion and diarrhea in early infancy. Hypomagnesemia and hypocalcemia were found in a 35-year-old man with muscle cramps, who bad been diagnosed as primary hypoparathyroidism. Oral magnesium therapy corrected the low serum calcium, magnesium and parathyroid hormone levels. We report an atypical case of isolated magnesium malabsorption in an adult.

Administration, Oral↗
PubMed1999

Central diabetes insipidus with Behçet's disease.

We encountered a case of Behçet's disease complicated with central diabetes insipidus. A hypothalamopituitary dysfunction is rare in Behçet's disease; only three cases of this association have been reported in the literature. Magnetic resonance imaging of the brain showed a dilatation of the left Sylvian vein and thickening of the pituitary stalk, which suggested intracranial vasculitic processes and lymphocytic infundibuloneurohypophysitis. The possible relationship of this disease combination is discussed as a form of autoimmune disease.

Adult↗
PubMed1999

[Effect of deliberate mild hypothermia on the incidence of surgical-wound infection and duration of hospitalization in neurosurgical patients].

We investigated the effect of mild hypothermia on the incidence of surgical-wound infection and duration of hospitalization, retrospectively. We randomly assigned 173 patients undergoing intracranial operation to mild hypothermic group (group H) of 122 patients or normothermic group (group N) of 51 patients. A water blanket and a convective device blanket were used for thermal control in the both groups. The temperature at the tympanic membrane was adjusted to 34.5 degrees C in group H and 36.0 degrees C in group N. Surgical-wound infection was found in 4 of 122 patients (3.3%) of group H but in none of 51 patients (0%) of group N. The duration of hospitalization was 36.0 +/- 25.5 days in group H and 40.2 +/- 36.9 days in group N. There were no statistical differences of the incidence of surgical-wound infection and duration of hospitalization between the two groups. However, the duration to suture removal was significantly longer in group H than in group N (8.3 +/- 1.6 vs 7.8 +/- 0.8 days). Although the effects of deliberate mild hypothermia for neurosurgery on the incidence of surgical-wound infection and duration of hospitalization were little, it may affect the recovery process of such patients.

Adult↗
PubMed1999

[Clinical effects of combination therapy with cefozopran and tobramycin for severe infections in patients with hematologic diseases].

We studied clinical effect of a combination therapy with cefozopran (CZOP) and tobramycin (TOB) for infections in 80 patients with hematologic diseases in 15 institutes. Combined doses with CZOP 2 g and TOB 60-90 mg twice a day had been given intravenously. Of the 80 patients, 61 patients (42 with acute leukemia, 10 with malignant lymphoma, 3 with aplastic anemia, 2 with chronic myeloid leukemia, 2 with multiple myeloma, and 2 with myelodysplastic syndrome) were evaluable. Those consisted of 6 patients with septicemia, 49 with suspected septicemia, 3 with pneumonia, and 3 with other infections. Clinical efficacy by the treatment was excellent in 24, good in 17, fair in 9, and poor in 11 patients, and the overall efficacy rate including excellent and good was 67.2%. Microbiologically, 5 of the 6 patients with septicemia (1 coagulase negative Staphylococcus, 2 S. pneumoniae, 1 S. oralis, and 1 E. coli) were responded. The efficacy rate in patients with severe granulocytopenia showing 100/microliter or lesser neutrophil counts during the drug administration was 57.1% (12/21). Side effects and abnormal changes of clinical laboratory findings were observed in 5 patients, and 16 patients, respectively, but most of them were mild. The findings above suggested that the combination therapy with CZOP and TOB is useful as an empiric therapy for severe infections in patients with hematologic diseases.

Adult↗
PubMed1999

[The role of mitochondria in apoptosis in U937 and Molt-4 cells: difference in order of mitochondrial membrane potential (delta psi m) reduction and interleukin-1 beta-converting enzyme (ICE) on signal transduction pathway in each cell type].

Time-course-analysis of two apoptotic events of DNA fragmentation and delta psi m reduction revealed that delta psi m reduction preceded DNA fragmentation in U937 and Molt-4 cells treated with etoposide (ETP). DNA fragmentation and delta psi m reduction were inhibited by N-acetylcysteine (NAC) in both cell lines treated with ETP. These findings suggest that DNA fragmentation was inhibited through maintenance of delta psi m. Z-Asp-CH2-DCB, interleukin-1 beta-converting enzyme (ICE) specific inhibitor, inhibited ETP-induced DNA fragmentation and delta psi m reduction in U937 cells. This suggests that activation of ICE is an earlier event than delta psi m reduction. On the other hand, in Molt-4 cells, Z-Asp-CH2-DCB inhibited ETP-induced DNA fragmentation but not delta psi m reduction, suggesting that delta psi m reduction occurs earlier than activation of ICE.

Apoptosis↗
PubMed1999

[Study of transforming growth factor-alpha expression in duodenal ulcer].

Various growth factors were also reported to promote healing of peptic ulcer. We have used a monoclonal antibody in conjunction with a standard immunohistochemical technique to characterize the expression of transforming growth factor-alpha (TGF-alpha) in duodenal ulcer. TGF-alpha immunoreactivity is found in Brunner's gland, also in immature gland and in duodenal epitheliums, but not in gastric metaplasia of the duodenum. TGF-alpha expression of healing and scar stage was higher than that of active stage. The presence or absence of Helicobacter pylori infection did not affect the expression of TGF-alpha in duodenal ulcer.

Adult↗
PubMed1999

Antacids have no influence on the pharmacokinetics of rabeprazole, a new proton pump inhibitor, in healthy volunteers.

AIM: This randomized, open-label, crossover study was conducted to evaluate the effect of a single dose of antacid, aluminum and magnesium hydroxide suspension, on pharmacokinetics of rabeprazole in healthy male volunteers. SUBJECTS AND METHODS: Twelve subjects were randomly divided into 6 groups of 2 subjects each, and received 20 mg of rabeprazole either without antacid, concomitantly with antacid, or one hour after administration of antacid in three experimental arms with washout period of one week. The concentrations of rabeprazole in plasma were determined by high performance liquid chromatography. RESULTS: Rabeprazole was well tolerated at the 20 mg dose level when given with or without antacid. The pharmacokinetic parameters, Cmax, t(max), AUC and t1/2, showed no statistically significant differences when rabeprazole was administered alone, concomitantly with antacid or one hour after antacid administration. CONCLUSION: No influence of single dose of antacid on pharmacokinetics of rabeprazole was observed.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed1999

[Ventricular fibrillation during mild hypothermic therapy in a patient undergoing neurosurgery].

A 35 year old male for mild hypothermic therapy for neurosurgery, developed ventricular fibrillation. Total resection of cerebral arteriovenous malformation was performed under mild hypothermic therapy, with the target core temperature of 33 degrees C. Intraoperatively cooling rate was low and a reduction of peripheral temperature associated with metabolic acidosis was noted. After the conclusion of the operation and during transferring the patient to an intensive care unit, multiple ventricular premature beats were noted. Thereafter, ventricular tachycardia developed proceeding ventricular fibrillation. We suggest that careful management of thermal and cardiovascular systems is required to prevent adverse events during mild hypothermic therapy.

Adult↗
PubMed1999

[Helicobacter pylori infection and histological types of gastric cancer].

The relationship between Helicobacter pylori (H. pylori) infection and gastric cancer was evaluated clinicopathologically by histological types of gastric cancer (intestinal or diffuse type). Histological findings of resected stomach tissues and serum anti-H. pylori IgG antibody titers obtained in patients with early gastric cancer revealed H. pylori infection and associated inflammatory changes in all cases, irrespective of histological types of cancer, and suggested that diffuse type cancer occurs in the mucosa with marked inflammation at a relatively early stage of H. pylori infection, while intestinal type cancer occurs at a relatively late stage of infection in parallel with the progression of mucosal atrophy and intestinal metaplasia. Results of immunohistochemical staining showed high incidence of secretory components in and around cancer foci, suggesting that immunological mechanisms for H. pylori infection play a role in the development of gastric cancer regardless of its histological type.

Adenocarcinoma↗