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Biomedical subjects

M Satoh

Publications and source records attributed to M Satoh.

At least 847 records · Page 47Linked to original sources
PubMed1990

Pentobarbital attenuates stress-induced increases in noradrenaline release in specific brain regions of rats.

To examine whether anxiolytic action of drugs acting at the GABA/BZD-chloride channel complex may be related to the brain noradrenergic system, we investigated the effect of pentobarbital, a typical barbiturate which has potent GABA modulating properties, on increased NA release in nine brain regions of stressed rats. Pentobarbital (10 and 25 mg/kg) was injected IP 65 min before sacrifice (5 min before one-hour immobilization stress). Levels of 3-methoxy-4-hydroxyphenylethyleneglycol sulfate (MHPG-SO4), the major metabolite of brain noradrenaline (NA), and of plasma corticosterone, were fluorometrically determined. Pentobarbital treatment by itself increased MHPG-SO4 levels in the thalamus, locus coeruleus (LC) region, midbrain and basal ganglia of nonstressed rats. Stress produced increases in MHPG-SO4 levels in all brain regions examined and elevation of plasma corticosterone levels. Pentobarbital attenuated, in a dose-dependent manner, stress-induced increases in MHPG-SO4 levels in the hypothalamus, thalamus, anterior cerebral cortex, LC region and basal ganglia and also attenuated the stress-induced elevation of plasma corticosterone levels. These data suggest that pentobarbital can attenuate both stress-induced increases in NA release in specific brain regions as well as activation of the hypothalamo-pituitary-adrenocortical system. These attenuating effects may be related to the anxiolytic action of barbiturates.

Animals↗
PubMed1990

Somatostatin is increased in the dorsal root ganglia of adjuvant-inflamed rat.

To determine whether biosynthesis of somatostatin is enhanced in the primary sensory neurons by inflammatory pain, we examined the effects of adjuvant inoculation on the content of immunoreactive somatostatin, mainly composed of somatostatin-14 and somatostatin-28, in the dorsal root ganglia and the spinal cord of the rat. The adjuvant inoculation, which produced long-lasting inflammation and hyperalgesia, increased the content of immunoreactive somatostatin, especially somatostatin-14, in the dorsal root ganglia at L4-L6 levels with no change in the dorsal and ventral horns of lumbar enlargement. Such an increase was enhanced by an intrathecal injection of colchicine (0.2 mg) that inhibits axonal flow of somatostatin. Chronic administration of the anti-inflammatory analgesic, sodium diclofenac (3 mg.kg-1.d-1), abolished an adjuvant-induced increase in the content of immunoreactive somatostatin in the dorsal root ganglia. These results suggest that the turnover (biosynthesis and axonal flow) of somatostatin in the primary sensory neurons is enhanced in the presence of persisting inflammatory pain, and support the idea that somatostatin-containing primary afferents are involved in the transmission of pain in the spinal dorsal horn.

Animals↗
PubMed1990

The effect of high-energy underwater shock waves on implanted urinary bladder cancer in rabbits.

We have examined the effects of high-energy shock waves (HESW) on implanted urinary bladder cancer in rabbits. The bladder cancer was exposed to 2000 to 6000 shots of focused HESW under ultrasound guidance. Although only focal necrosis of the tumor was seen in the one-day HESW exposure (2000 shots), wider and deeper necrosis was observed in the tumors following serial HESW (4000 or 6000 shots; 2 or 3 days). These results indicate that serial HESW exposure has destructive effects on implanted bladder cancer in rabbits.

Animals↗
PubMed1990

Functional reconstruction of purified Gi and Go with mu-opioid receptors in guinea pig striatal membranes pretreated with micromolar concentrations of N-ethylmaleimide.

Functional coupling between mu-opioid receptors and GTP-binding regulatory proteins (G proteins) was investigated in reconstituted membranes of the guinea pig striatum. Selective mu-opioid agonists stimulated low-Km GTPase in striatal membranes, in a Na(+)-dependent manner. The same mu-opioid agonist [( D-Ala2, N-Me-Phe4, Gly5-ol]-enkephalin (DAGO)] caused no stimulation when the membranes were exposed to islet-activating protein (IAP; pertussis toxin). There was also no DAGO stimulation in preparations pretreated with a lower concentration (5 microM) of N-ethylmaleimide (NEM), which abolished the ADP-ribosylation of purified Gi (the G protein that mediates inhibition of adenylate cyclase) and Go (a G protein of unknown function purified from bovine brain) by IAP. In addition, as the NEM treatment caused no change in the mu-agonist binding, NEM could probably substitute for IAP in inactivating native G proteins, without exhibiting effects on the receptor binding in membranes. The mu-agonist stimulation of low-Km GTPase activity in NEM-treated membranes was recovered by reconstitution with purified Gi or Go. The mu-agonist stimulation of low-Km GTPase was additive when Gi and Go were simultaneously reconstituted in NEM-treated membranes in amounts of 0.5 pmol/assay, which was required for maximal recovery, in either reconstitution experiment. The present findings provide the first evidence that the mu-opioid receptor may exist in at least two different forms, separately coupled to Gi or Go.

Adenylate Cyclase Toxin↗
PubMed1990

Immunohistochemical detection of ras p21 in oral papilloma.

Twenty-four oral papillomas were fixed in a 10% formalin solution, and 5 mu paraffin sections were prepared by normal procedure. Using monoclonal antibody NCC-RAS-001 as the primary antibody, the expression of ras p21 in the oral papilloma was searched immunohistochemically by the Histostain SP kit. The ras p21 was detected in 10 (41.7%) of 24 oral papillomas. In the histologic expression, it was less frequently detected in keratinized cell layer and basal cell layer, and it was most often detected in the cytoplasm of the cells in the spinous cell layer. These findings suggested the close relation between the expression of ras p21 and the epithelial proliferation and differentiation in the oral papilloma.

Aged↗
PubMed1990

Oral senile amyloidosis in senescence accelerated mouse (SAM).

Oral senile amyloidosis in senescence accelerated mouse (SAM) was examined for two SAM sublines (P/2/Iw and R/1/Iw) and for various ages by light microscopy, immunohistochemistry, and electron microscopy. The amyloid deposition, identified by green birefrigence following Congo red stain, was observed only in P/2/Iw. In P/2/Iw, no amyloid deposition was found at age 6 months; however, frequency and extent of such deposits increased with advancing age. Distribution of amyloid deposition was as follows: along papillary layers of mucous epithelium in the tongue, the gingiva, the palate, and the buccal mucosa; foci in connective tissues; along vessels, muscles, and minor salivary glands. Immunohistochemically, the amyloid deposition was positive with anti-ASSAM serum being raised against a unique amyloid protein ASSAM which probably induced "senile systemic amyloidosis". P/2/Iw is useful as an animal model of oral senile amyloidosis.

Aging↗
PubMed1990

Bifemelane induces translocation of protein kinase C in the CA3, but not the CA1, region of guinea-pig hippocampus.

We made use of the [3H]phorbol 12,13-dibutyrate binding assay to investigate the effects of bifemelane on the subcellular distribution of protein kinase C in the CA3 and CA1 regions of guinea-pig hippocampal slices. Bifemelane, a drug that augments the long-term potentiation in the CA3 region, significantly induced the translocation of [3H]phorbol 12,13-dibutyrate binding activity from the cytosol to the membrane in a dose-dependent manner (10(-8) to 10(-6) M) and with no effects on total binding activity in the CA3 region. Bifemelane, at a concentration of 10(-6) M, was without effect on the subcellular distribution of [3H]phorbol 12,13-dibutyrate binding activity in the CA1 region. These observations suggest that bifemelane acts directly on the hippocampus to induce translocation of protein kinase C in the CA3 region. Such an effect may be associated with the bifemelane-induced augmentation of the long-term potentiation in this region of the brain.

Animals↗
PubMed1990

Regional lymph node metastasis in renal cell carcinoma: incidence, distribution and its relation to other pathological findings.

Extended ipsilateral lymphadenectomy performed on 102 patients with renal cell carcinoma revealed 21 patients (21%) having regional lymph node metastasis. Of the 21 patients, 6 (6%) had single-node metastasis and 15 (15%) multiple-node metastasis. PT, pV, pM, cell type and grade were all correlated with regional node metastasis. The metastatic lymph node foci were distributed along the pathways of normal lymphatic drainage. The recurrence of the disease was correlated with lymph node metastasis, indicating that metastasis is one of the prognostic factors. The very close correlation of node metastasis with vein invasion suggests that removal at least of the ipsilateral lymph node might be necessary when removal of a thrombus in the renal vein or vena cava is indicated.

Carcinoma, Renal Cell↗
PubMed1990

Alveolar bone loss of senescence-accelerated mouse (SAM).

SAM-R/1/Iw (senescence-accelerated mouse, resistant) and P/2/Iw (senescence-accelerated mouse, prone) under a conventional environment and eating standard pellets were examined for alveolar bone loss and the presence of periodontitis around maxillary and mandibular molars as a function of age. Neither SAM strain manifested a chronic periodontitis similar to that in humans, and no obvious plaque and calculus were observed. However, in both strains, 15% of M3 was lost after 13 months of age, and alveolar bone loss gradually increased with advancing age. Though there was no significant difference in the incidence of M3 loss between the two strains, P/2/Iw showed a higher alveolar bone loss around all molars than did R/1/Iw after one month of age throughout their life span. For M1, the difference in alveolar bone loss between P/2/Iw and R/1/Iw was significant, and it was probably caused by the difference in degree of molar eruption. Other factors, such as occlusal trauma and gingivitis, may play some role in alveolar bone loss.

Aging↗
PubMed1990

Pattern of medical care services utilization in Fiji.

The present study was designed to analyze sociodemographic and health related factors that influence the utilization of medical care services in Fiji by using the method of discriminant function. Some sociodemographic and health related independent variables had significant effects on the two patterns of modern and traditional medical services utilization. Discriminant function coefficients for sex, age and race are large enough to suggest the importance of discriminating between two patterns of medical care utilization. This suggests that traditional medical service is coexistent with modern medicine in Fiji and might play an extremely important role in providing health care for rural communities in the same way as modern medicine.

Adult↗
PubMed1990

Antinociceptive effects of oriental medicine kei-kyoh-zoh-soh-oh-shin-bu-toh in mice and rats.

Antinociceptive effects of peroral administration of an oriental medicine Kei-Kyoh-Zoh-Soh-Oh-Shin-Bu-toh (TJ-8023) were examined using rats and mice. TJ-8023 (100 mg.kg-1.d-1) inhibited the induction of adjuvant-induced hyperalgesia of rats in the paw-pressure test following prophylactic administration, and normalized the nociceptive threshold at a dose of 600 mg.kg-1.d-1, without effects on adjuvant-induced inflammation. Mice suffering from repeated cold stress showed a decrease in nociceptive threshold for tail-pressure stimulation. Such a hyperalgesia was reversed by a single (30 and 100 mg/kg) or repeated administration (100 and 300 mg.kg-1.d-1) of TJ-8023. The nociceptive threshold of non-stressed mice was not affected by TJ-8023 (100 mg/kg). Nociceptive responses of mice to cold-plate stimulation were also not affected by repeated administration of TJ-8023 (300, 600 and 1200 mg.kg-1.d-1). The present results demonstrate the antinociceptive action of TJ-8023, and suggest that it is more effective in easing a hyperalgesia in morbid state than in suppressing a nociception in the normal one.

Adjuvants, Immunologic↗
PubMed1990

Synthesis and absolute configurations of the cytotoxic polyacetylenes isolated from the callus of Panax ginseng.

Panaxacol (1) and dihydropanaxacol (2), cytotoxic polyacetylenes isolated from the callus of Panax ginseng, were synthesized starting from D-(-)-diethyl tartrate. The absolute configuration of 1 was determined to be 9R, 10R and the absolute configuration at C-3 of 2 was tentatively assigned as 3S by the application of the R(+)-alpha-methoxy-alpha-(trifluoro methyl)phenylacetyl (MTPA) method.

Alkynes↗
PubMed1990

Requirements of non-pharmacologic interventions in the treatment of recurrent sustained ventricular tachycardia.

Sixty-five patients (pts) with sustained ventricular tachycardia (VT) and 1 patient with symptomatic nonsustained VT were included in this study. Of these, 5 had died before electrophysiologic study (EPS) or determination of effective antiarrhythmic drugs. Inducibility of VT by our protocol varied from 69 to 100% according to underlying diseases. Drug efficacy was evaluated by using conventional drugs in all and using flecainide and amiodarone in some. However, more than 50% of pts with inducible VT were found to be resistant to pharmacological therapy. Fourteen of 26 pts with drug-refractory VT, underwent surgical therapy. In all pts, the site of VT origin was determined and VT was either eradicated or clinically controlled in 86% of the patients. Catheter ablation was tried in 9 pts at the earliest activation site of VT or at the site where pace-mapping produced the best result in configuration in the QRS complex as the clinical VT. Prophylactic effect was confirmed in 60% but VT recurred in 3 pts. These VT became responsive to anti-arrhythmic drugs in 2 pts. In thirteen pts who died suddenly during the follow up period, none had adequate antiarrhythmic drugs. One patient died after operation because of residual VT among four different QRS morphologies found preoperatively. In conclusion, the success rate antiarrhythmic drug prophylaxis against VT induction or recurrence did not exceed 50%, therefore non-pharmacological interventions such as surgery or catheter ablation may be required.

Adolescent↗
PubMed1990

Conduction through the reentrant circuit in recurrent sustained ventricular tachycardia evaluated by use of transient entrainment.

Using transient entrainment, the effect of the paced cycle length on the conduction through the reentrant circuit was assessed in recurrent sustained ventricular tachycardia (VT). Fourteen patients were included in the present study and their VTs were paced at multiple cycle lengths while the criteria of entrainment were confirmed at each paced cycle length. Then, the effect of the paced cycle length upon the conduction time, which was evaluated by the measurement of the time interval from stimulus to the entrained electrogram, was analyzed. In the overdrive pacings of VT, 3 response patterns in conduction time were observed: an increasing pattern (n = 8), a flat pattern (n = 5) and a decreasing pattern (n = 1) while the local conduction time outside the reentrant circuit remained unchanged at comparable paced cycle lengths. A decremental property is the likely mechanism responsible for the paced cycle length-dependent prolongation. As for the flat pattern, the existence of a fully excitable gap may be responsible. A paced cycle length related change in the reentrant circuit may account for the decreasing pattern. By using transient entrainment, the electrophysiological characteristics of the reentrant circuit can be evaluated and the information so gathered may be valuable in analyzing the action of antiarrhythmic drugs on the slow pathway.

Adolescent↗
PubMed1990

Ventricular tachycardia with two possible exits from one re-entrant circuit.

A case of sustained ventricular tachycardia (VT) with two possible exits from one re-entrant circuit is described in this paper. The patient was a 27-year-old female who had undergone corrective surgery for tetralogy of Fallot at the age of 8, and developed VT of distinctly different QRS configurations. The exit of one VT was at the right ventricular (RV) outflow tract and the other at the RV apex as determined by endocardial and pace-mapping. Continuous and split activities were observed at the RV outflow tract during both types of VT. One VT was entrained by rapid pacings, and the causal mechanism was thought to be re-entry and common re-entrant circuit was established for two QRS configurations of VTs. A discrepancy was observed between the site of the earliest activation and the site of the pace-mapping which resulted in QRS configuration of VT of the RV apex origin. The findings in this paper should be considered when contemplating aggressive therapy such as electrical ablation.

Adult↗
PubMed1990

Diagnosis of peripheral lung cancer using a new type of endoscope.

A new fiberoptic bronchoscope, the BF-2.2T, has been designed to go through the 2.6-mm channel of the conventional fiberoptic bronchoscope (Olympus BF-1T20). It measures 2.2 mm in outer diameter; it has a visual angle of 75 degrees, a range of observation of 3 to 50 mm, an effective length of 1,150 mm, and a total length of 1,400 mm. It bends at 120 degrees in an upward direction and at 120 degrees in a downward direction. The 2.2-mm tip of the BF-2.2T bends like a conventional fiberoptic bronchoscope, and this is the main characteristic of this instrument. The BF-2.2T facilitates clinically satisfactory observation and photography, as a method for detecting peripheral lung cancer.

Adenocarcinoma↗
PubMed1990

Follow-up study on metastatic cerebellar tumor surgery--characteristic problems of surgical treatment.

Recently, the incidence of metastatic cerebellar tumors has increased. The authors operated on 12 cases of metastatic cerebellar tumors, with total or subtotal removal of nodules in brain metastases. Surgical complications observed as a result of postoperative investigation are presented. 1) Some cases developed carcinomatous meningitis within a short period. During removal of a tumor on the superior cerebellar surface attention should be paid to the prevention of dissemination to the cerebral cisterns adjacent to the tumor. 2) Some cases demonstrated peritoneal metastasis probably due to dissemination via the ventriculoperitoneal shunt tube, suggesting that great care should be taken during a shunt operation after removal. 3) Both carcinomatous meningitis occurring after removal and remote metastasis via the shunt tube were related to recurrence after removal of the cerebellar metastatic lesion, raising the issue of whether or not total macroscopic removal should be included in the indications for surgical treatment of cerebellar metastasis. Those cases in which surgery is indicated should also be routinely treated by postoperative irradiation.

Aged↗