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Biomedical subjects

M Shibata

Publications and source records attributed to M Shibata.

At least 235 records · Page 13Linked to original sources
PubMed1998

The effect of electroconvulsive treatment on thermal hyperalgesia and mechanical allodynia in a rat model of peripheral neuropathy.

UNLABELLED: We tested the ability of electroconvulsive treatment (ECT) to block thermal hyperalgesia and mechanical allodynia in rats with peripheral neuropathy. Repeated ECT (six times daily) significantly reduced thermal hyperalgesia 48 h after the end of the final treatment but had no significant effects on mechanical allodynia. Single ECT had no significant effect on thermal hyperalgesia or mechanical allodynia. Neither single nor repeated ECT had any significant effect on the withdrawal response of sham-operated paws and untreated rats to thermal and mechanical stimuli. The anti-thermal hyperalgesic effect of repeated ECT was reversed by the previous administration of nifedipine (L-type Ca2+ channel blocker). We conclude that, due to effects on the voltage dependent calcium channel, ECT modified one of the pain behaviors induced by nerve injury. ECT may be of use in the treatment of human neuropathic pain. IMPLICATIONS: We showed that repeated electroconvulsive treatment reduced pain responses to heat stimulation after sciatic nerve injury in rats. This study implies a possible therapeutic effect of electroconvulsive treatment on neuropathic pain.

Animals↗
PubMed1998

The effect of varied doses of epinephrine on duration of lidocaine spinal anesthesia in the thoracic and lumbosacral dermatomes.

UNLABELLED: The efficacy of epinephrine in prolonging spinal analgesia has recently been confirmed in the lumbosacral but not in the thoracic, segments. Most previous studies used doses of epinephrine smaller than 0.3 mg. We studied the effects of 0.2, 0.4, or 0.6 mg of epinephrine added to hyperbaric lidocaine 60 mg in 7.5% dextrose solution for spinal anesthesia. Eighty patients were randomly divided into four groups: Group A received lidocaine without epinephrine, Group B received lidocaine plus 0.2 mL (0.2 mg) of epinephrine 1:1000 solution, Group C received lidocaine plus 0.4 mL (0.4 mg) of epinephrine, and Group D received lidocaine plus 0.6 mL (0.6 mg) of epinephrine. The maximal cephalad sensory level was between T2 and T3 for all groups. The median times for analgesia to regress two and four segments were significantly prolonged in Group D, but not in either Group B or C, compared with those in Group A. Times for regression to T12 and L3 were significantly prolonged in Groups B, C, and D compared with Group A. We conclude that the dose-dependent relationship of spinal analgesia can be applied to epinephrine, and that larger doses prolong lidocaine spinal anesthesia in the thoracic as well as the lumbosacral dermatomes. IMPLICATIONS: Prolongation of lidocaine spinal analgesia by intrathecal epinephrine is established in the lumbosacral, but not in the thoracic, dermatomes. Three doses of epinephrine--0.2, 0.4, and 0.6 mg--were compared. A dose-dependent response and significant prolongation with the 0.6-mg dose in the thoracic dermatomes were confirmed.

Adult↗
PubMed1998

Effect of barbiturate on central pain: difference between intravenous administration and oral administration.

OBJECTIVE: To examine whether the oral administration of barbiturates is of clinical use in a patient with central pain. SETTING: Pain Clinic, Osaka University Medical Hospital, Osaka, Japan. PATIENT: A patient with central pain after loss of his left upper extremity. INTERVENTIONS: A 50-mg dose of intravenous amobarbital, which produced a plasma concentration of 2.5-4.0 microg/ml, was effective in reducing the central pain. Subsequently, doses of 300-400 mg/day were administered orally; these succeeded in achieving similar plasma concentration levels. RESULTS AND CONCLUSIONS: Oral administration of barbiturate did not alleviate central pain, even when the plasma concentration was the same as the effective level in intravenous use. Pharmacokinetic and pharmacodynamic factors more complex than simple plasma concentrations may be involved in producing the difference in the effects.

Administration, Oral↗
PubMed1998

Rat tibial nerve regeneration after postoperative administration of cis-diaminedichloroplatinum.

We investigated the results of postoperative administration of cis-diaminedichloroplatinum on nerve regeneration in rats. Forty-two Lewis rats were divided into two groups, receiving end-to-end suture or nerve grafting. Subgroups of the suture group included control, a one-time dose of cis-diaminedichloroplatinum (3 mg/kg), and four doses of the same amount of cis-diaminedichloroplatinum. Subgroups in the nerve grafting group included a control and a four-dose group. Functional recovery was measured by gait analysis using the tibial function index. Biopsies of nerve were taken distal to the suture site for histologic evaluation 20 weeks postoperatively. Tibial function index at 4, 6, and 20 postoperative weeks in the four-dose group was significantly inferior to that of the control group in the suture group. Tibial function index was inferior in the four-dose group until 10 weeks postoperatively compared with control in the nerve grafting group; however, there was no significant difference. The percentage of neural tissue in the one-dose suture group was significantly greater than in the four-dose suture group. These results suggest that postoperative cis-diaminedichloroplatinum administration may have a detrimental effect on nerve regeneration.

Anastomosis, Surgical↗
PubMed1998

[Analysis of transmission of Burkholderia cepacia isolates in an intrahospital by randomly amplified polymorphic DNA-PCR method].

Strains of Burkholderia cepacia isolated in our hospital from November 1995 to September 1996 were classified with randomly amplified polymorphic DNA-PCR (RAPD-PCR) and conventional biochemical tests (ID test.NF-18, API20NE, and Neg Combo 4J kit), and intrahospital isolates of B. cepacia were analysed. During the period 28 strains from inpatients and 2 from medical apparatus were isolated. Twenty four of 28 (85.7%) were from sputum. In 1996 from January to February, 20 strains were detected from 8 inpatients, and two strains were from the nebulizers at the Trauma and Critical Care Center (TCC). With typing of B. cepacia by conventional methods no epidemiological relations among isolates were found. However, DNA patterns of original isolates from the nebulizers at TCC by RAPD-PCR were identical with those of isolates in sputa from patients in other wards who had stayed at TCC, indicating that TCC was an initial source of transmission and the strain was transmitted with the patients to the wards. These results suggest that RAPD-PCR method might be a useful tool to analyse an epidemiological survey for intrahospital transmission of isolate.

Burkholderia Infections↗
PubMed1998

Tissue-specific high-level expression of human endogenous retrovirus-R in the human adrenal cortex.

In an attempt to clarify the biological nature of a human endogenous retrovirus (HERV), HERV-R, which is a single-copy type of HERVs and is conserved as a full-length viral sequence, the expression of HERV-R mRNA in normal autopsied systemic organs was examined by Northern blot analysis. The expression showed different levels among individuals, with the adrenal glands expressing the highest level of HERV-R among all organs tested, except for the placenta. In various adrenal tumors, HERV-R was expressed at high levels in all cortical adenomas but less so in pheochromocytomas. In situ hybridization revealed the expression of HERV-R to be localized in all layers of the adrenal cortex, but not in the medulla. This high-level expression of HERV-R in the adrenal cortex may possibly relate to differentiation and/or steroid production by adrenocortical cells.

Adrenal Cortex↗
PubMed1998

[Effect of lafutidine, a novel antiulcer agent, on healing and relapse of acetic acid-induced gastric ulcer in rats].

Effect of lafutidine ((+/-)-2-(furfurylsulfinyl)-N-[4-[4-(piperidinomethyl)-2-pyr idyl] oxy-(Z)-2-butenyl] acetamide, FRG-8813), a novel antiulcer agent, on the healing and relapse in acetic acid-induced gastric ulcer in rats was investigated. Lafutidine at 1, 3 or 10 mg/kg, twice daily for 10 days reduced the ulcer area in a dose-dependent manner, and the effect by 10 mg/kg of lafutidine was significant. The effect of famotidine at 1 mg/kg and cimetidine at 30 mg/kg, which have almost equal antisecretory activity to lafutidine at 10 mg/kg, on the ulcer area was not significant. Effect on the healing and relapse was assessed by endoscopy for 25 weeks after the induction of gastric ulcer. Drugs were administered twice daily for 11 weeks. Lafutidine at 3 mg/kg and famotidine at 1 mg/kg accelerated the healing, but cimetidine at 30 mg/kg did not. Cumulative relapse rate and inflammatory cell infiltration were significantly reduced in rats initially treated with lafutidine. Famotidine and cimetidine had no effect. In conclusion, lafutidine accelerated ulcer healing and prevented ulcer relapse in rats.

Acetamides↗
PubMed1998

Insecticidal and antifungal activities of aminorhodanine derivatives.

Aminorhodanine (1) showed strong insecticidal activity against Culex pipiens pallens and Musca domestica, with respective LD50 values of 0.21 microgram/insect and 0.87 microgram/insect. Compound 1 had antifungal activity against Aspergillus niger ATCC-16404, Trichophyton mentagrophytes IFO-32412, Candida albicans ATCC-10231, Hansenula anomala OPS-308 and Penicillium expansum IFO-8800. In particular, 1 had potent antifungal activity against Aspergillus niger ATCC-16404, its minimal inhibitory concentration (MIC) being 6.25 micrograms/ml. Both activities of 1 were much higher than those of rhodanine (4), suggesting that the introduction of an amino group into N-3 of 4 plays an important role in the biological activity of rhodanine-related compounds. On the other hand, N-acetylaminorhodanine (2) and N-benzoylaminorhodanine (3) did not show either activity, suggesting that the free amino group at N-3 of 1 is closely related to the inhibitory activity of rhodanine derivatives.

Animals↗
PubMed1998

An ultrastructural and immunohistochemical study of PC12 cells during apoptosis induced by serum deprivation with special reference to autophagy and lysosomal cathepsins.

In addition to the caspase family of proteinases, cathepsin D, a lysosomal aspartic proteinase, has been suggested to act as a proapoptotic mediator in mammalian cells. To further understand the roles of cathepsins B and D in apoptosis of the cells, we examined the precise alteration processes of ultrastructures and immunoreactivity for these enzymes in PC12 cells cultured under serum deprivation. Laser scanning microscopy showed immunoreactivity for cathepsins B and D to be finely distributed in the cytoplasm of PC12 cells at the onset of culture under serum deprivation. At 3 h after the onset of culture, the immunoreactivity for cathepsin B slightly decreased in the cells, while immunodeposits for cathepsin D in the cells became more intense and larger in size than those at 0 h. Positive staining for TUNEL in nuclei of the cells appeared at 6 h, though fewer in number. Corresponding to the increase in the number of TUNEL-positive cells at 12 h and 24 h, the immunoreactivity for cathepsin B was drastically diminished in the cells, whereas that for cathepsin D was significantly augmented, especially in TUNEL-positive cells. Electron microscopically, autophagic vacuoles/autolysosomes appeared in the cytoplasm of the cells 3 h after the onset of culture. A distinct nuclear change showing relatively condensed chromatin first appeared in the peripheral part of the nuclei at 6 h. The number of PC12 cells having nuclei with chromatin condensation increased especially at 24 h, while these cells showed shrinkage of both their cytoplasm and nuclei. Dense bodies and autophagic vacuoles with limiting membranes were seen in these cells. These results showing the occurrence of autophagy and imbalance of protein amounts between cathepsins B and D during apoptosis may argue for our hypothesis that these enzymes are, in part, involved in the cell death cascade for PC12 cells following serum deprivation.

Animals↗
PubMed1998

Reconstruction of a congenital hypoplastic thumb with use of a free vascularized metatarsophalangeal joint.

Reconstruction of a Blauth type-IIIB hypoplastic thumb with use of a free vascularized metatarsophalangeal joint was performed in four patients (four hands). Several tendon transfers also were performed, either primarily or secondarily, to mobilize the reconstructed thumb. Three patients (three hands) were followed for at least two years after the reconstruction; the results for these three patients were compared with those for four patients (six hands) who had been managed with pollicization of the index finger because of a similar deformity of the thumb. The patients were evaluated with regard to grip strength, key-pinch strength, and the range of motion of the joints of the thumb in the operatively treated and contralateral hands as well as with regard to skill in performing activities of daily living as assessed with use of the Kobe hand-function test. Although the appearance of the thumb was closer to normal in the group that had had the pollicization procedure, total function of the hand and grip strength were greater in the group that had had the transfer procedure. We believe that reconstruction of an unstable hypoplastic (Blauth type-IIIB) thumb with use of a vascularized metatarsophalangeal joint is an acceptable alternative to pollicization of the index finger.

Activities of Daily Living↗
PubMed1998

[Case report of the right-sided aortic arch (N-type): new classification based on macroscopic observations].

We report on a case with unusual origin of the left subclavian artery, so-called N-type found in a 62-year-old Japanese male in 1995. We took the opportunity in proposing for a new classification based on macroscopic observations. In the present observation, the following arteries branched off from the aortic arch in the order of the left common carotid, the right common carotid, the right subclavian and the left subclavian arteries. There was an aortic diverticum between the left subclavian artery and the dissending aorta. The left subclavian artery passed between the esophagus and the thoracic vertebrae. The arterial ligament connected the left pulmonary artery with the aortic diverticulum of the left subclavian artery. According to our observations, the arch of the aorta, descending aorta, aortic diverticulum of the left subclavian artery, arterial ligament and pulmonary artery joined to foam an incomplete vascular ring around the trachea and esophagus. This case can be classified into the N-type according to classifications by Adachi (1928), Williams (1932, 1935) and Nakagawa (1939). This may be the 22nd report in Japan regarding this kind of combined variations. Our classification also includes those by Takemura (1990) and Edwards (1964). An explanation of the new classification is described below and is also shown in Fig. 3. Abbreviations for classification types have been arranged in the order of the relation to the esophagus, the mirror-image subtyping of the Takemura's classification and the location of the arterial ligament. For example, type Na1 (present case) represents the left subclavian artery passing behind the esophagus, mirror-image to the Takemura's G-type, and left arterial ligament.

Aorta, Thoracic↗
PubMed1998

Rheumatoid vasculitis in a patient with seronegative rheumatoid arthritis.

We report on a 47-year-old woman with a 10-year history of seronegative rheumatoid arthritis (RA) who had experienced an episode of bilateral aseptic pleuritis, and in whom livedo reticularis and ulcers had developed on both lower extremities. Histological examination revealed rheumatoid vasculitis. In rheumatoid vasculitis, high titers of rheumatoid factors are commonly observed. In our case, however, there have been no characteristic laboratory findings throughout the course of the disease so far, despite the active RA. This report describes a rare case of seronegative RA with systemic rheumatoid vasculitis.

Arthritis, Rheumatoid↗
PubMed1998

[Immunohistochemical study of p53, p27 and PCNA expression in esophageal cancer].

We evaluated the clinical significance of p53, p27 and PCNA expressions in esophageal squamous cell carcinomas. Operative specimens obtained from 70 patients with esophageal squamous cell carcinomas were investigated by staining with antibodies against p53, p27 and PCNA. The correlations among p53, p27 and PCNA expression, clinicopathologic factors and prognosis were studied. The expression of p53 was observed in 55.7%, and it did not correlate to histologic classification, growth pattern, and lymphatic invasion. The expression of p27 was observed in 48.6%, and it correlated to lymph node metastasis. The PCNA positive index (PCNA-PI) was high in the p27 negative cases. The p53 positive and p27 negative group revealed the worst survival rate among groups. Therefore, the p27 positive case, often associated with well differentiated carcinoma, tends to have a slower tumor-growth rate and better prognosis. It is suggested that immunohistochemical assessment on the p53 and p27 expressions would be useful to the recognize the malignant potential and differentiation of squamous cell carcinoma of the esophagus.

Aged↗
PubMed1998

Overexpression of S-adenosylmethionine decarboxylase (SAMDC) in early Xenopus embryos induces cell dissociation and inhibits transition from the blastula to gastrula stage.

Xenopus early embryos contain relatively low levels of S-adenosyl-methionine decarboxylase (SAMDC) and its mRNA. When SAMDC mRNA was injected into Xenopus embryos, it was preserved until the blastula stage and induced a large increase in SAMDC activity. The SAMDC-overexpressed embryos developed normally until the blastula stage but at the early gastrula stage cells which received the mRNA, dissociated autonomously and stopped synthesizing protein. In a hypotonic medium, the dissociated cells, and hence whole embryos, autolyzed. However, in isotonic media dissociated cells did not autolyze, although they did not divide and their DNA and RNA synthesis activity was greatly inhibited. The effects of SAMDC overexpression were abolished by coinjection of ethylglyoxal-bis(guanylhydrazone) (EGBG), a specific inhibitor of SAMDC. In SAMDC-overexpressed embryos the level of putrescine decreased and that of spermidine increased, though to limited extents, resulting in a considerable decrease in the putrescine/spermidine ratio. However, direct injection of spermidine did not mimic the effect of SAMDC overexpression, and putrescine coinjected with SAMDC mRNA to maintain the normal putrescine/spermidine ratio did not rescue the embryos. Conversely, the level of S-adenosylmethionine (SAM) greatly decreased and coinjection of SAM, which restored the level of SAM, rescued the embryos. We concluded that in SAMDC-overexpressed embryos a SAM-deficient state was induced and this caused cell dissociation and inhibition of transition from the blastula to gastrula stage. We suggest that the SAM-deficient embryos obtained in the present study provide a unique system for studying the cellular control mechanism underlying the blastula-gastrula transition.

Adenosylmethionine Decarboxylase↗
PubMed1998

[Association of extrahepatic autoimmune diseases in primary biliary cirrhosis--clinical statistics and analyses of Japanese and non-Japanese cases].

Abnormality of humoral and cellular immune functions and the association of autoimmune diseases are frequently observed in primary biliary cirrhosis (PBC). The prevalence of autoimmune diseases was studied in 97 Japanese patients with PBC. Sjögren's syndrome was diagnosed in 33 percent of these patients, arthritis in 22 percent, scleroderma in 11 percent, CREST syndrome in 4 percent, Raynaud's phenomenon in 8 percent, autoimmune thyroiditis in 3 percent, respectively. Fifty-five percent of the patients had at least one autoimmune disease and 19 percent had two or more such disorders. In this study, the prevalence of associated autoimmune diseases was somewhat low compared to that of European and American studies. Geographical variations, however, might exist in the prevalence of autoimmune associations, and the frequent occurrence of coexisting autoimmune diseases suggests an autoimmune pathogenesis in PBC.

Adult↗
PubMed1998

[Prevention of contamination with a heat-and-moisture-exchanger (HME) and bacterial filter during clinical anesthesia].

Although the use of HME and bacterial filter is a common practice to protect the anesthesia machine as well as the patients from bacterial contaminants, there is no report demonstrating the effectiveness of this filter in clinical anesthesia setting. We evaluated the actual effectiveness of the filter during clinical use. While the anesthesia breathing circuit, two bacterial filters (BB 50 T, Nihon PALL) and anesthesia bag, which were sterilized with ethylen oxide gas (EOG), were connected to the anesthesia machine and used continuously for one week, EOG sterilized HME and bacterial filter (BB 25 A, Nihon PALL) were changed before each anesthesia. Culture samples were taken from the BB 25 A, the breathing circuit and the machine side of the BB 50 T. Of the 117 BB 25 A samples taken, 6 were positive for Micrococcus, alpha-Streptococcus, Bacillus, and Staphylococcus epidermidis. From 21 breathing circuit "internal" samples, one was positive for Bacillus, Staphylococcus epidermidis. But the contamination from outside sources was suspected, since all the BB 25 as used with this circuit were negative. Use of BB 25 A prevents contamination of the breathing circuit for a period of one week. If we use BB 25 A in every anesthesia case, the changing of the breathing circuit is unnecessary, reducing the cost and simplifying procedures during clinical practice.

Anesthesiology↗
PubMed1997

Effects of increased extracellular potassium on influx of sodium ions in cultured rat astroglia and neurons.

Membrane depolarization by elevated extracellular K+ concentration ([K+]o) causes rapid Na+ influx through voltage-sensitive Na+ channels into excitable cells. The consequent increases in intracellular Na+ concentration ([Na+]i) and/or [K+]o stimulate Na+,K+-ATPase activity, which in turn stimulates energy metabolism and rates of glucose utilization (CMR[glc]) in neurons. We previously reported that in cultured cells elevated [K+]o stimulated CMR(glc) in neurons but not astroglia; but increasing [Na+]i by opening voltage-sensitive Na+ channels with veratridine stimulated CMR(glc) in both. These results indicated that Na+ influx plays a key role in the regulation of energy metabolism in neurons and astroglia, but that depolarization of astroglial membranes by elevated [K+]o does not open voltage-sensitive Na+ channels as it does in neurons. To examine this possibility directly we have measured the effects of increased [K+]o and of veratridine on Na+ influx into cultured rat astroglia and neurons. Cells were incubated in bicarbonate buffer containing ouabain (1 mM), tracer amounts of 22NaCl, and various concentrations (5.4, 28, 56 mM) of K+ or 75 microM veratridine for 0-60 min. Cells were digested and assayed for intracellular 22Na+ content. Elevated extracellular K+ stimulated tetrodotoxin-sensitive 22Na+ accumulation in cultured neurons but inhibited 22Na+ influx in astroglia. Veratridine-stimulated Na+ influx in both astroglia and neurons (144% and 133%, respectively), and these effects were completely blocked by 10 microM tetrodotoxin. These results indicate that increased [K+]o does not open voltage-sensitive Na+ channels and may inhibit Na+ influx in astroglia.

Animals↗