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T Nakashima

Publications and source records attributed to T Nakashima.

At least 325 records · Page 18Linked to original sources
PubMed1994

Comparative study on sudden deafness by two nationwide epidemiological surveys in Japan.

Nationwide epidemiological surveys of sudden deafness were conducted in 1972 and 1987 by the Research Committee of the Japanese Ministry of Health and Welfare. Sex ratio (men over women) of definite cases of sudden deafness was 1.19 in 1972 and 0.96 in 1987. The number of patients with sudden deafness was more common between 30 and 49 years of age in 1972, whereas it was more common between 50 and 59 years of age in 1987. When the incidence of sudden deafness in the overall population was calculated, this disorder was found to be more frequent in people between 50 and 59 years of age both in 1972 and 1987. However, the incidence of sudden deafness per population was more increased in people from 50 to 75 years of age in 1987 than in 1972.

Adolescent↗
PubMed1994

[Flow cytometric DNA analysis and chemosensitivity in squamous cell carcinoma of the head and neck].

Cellular DNA content and succinate dehydrogenase activity of 92 human head and neck (34 laryngeal, 24 pharyngeal, 21 oral cavity, 13 maxillary) squamous cell carcinomas were examined, and DNA ploidy status and chemosensitivity were analyzed and compared. DNA aneuploidy was observed in 54 tumors (58.7%). The aneuploid pattern was most common in tumors of the maxillary sinus (84%), and least common in tumors of the larynx (41.3%). Histologically, aneuploidy was detected in 71.4% of poorly-differentiated, 63.8% of moderately-differentiated and 37.5% of well-differentiated squamous cell carcinomas. There was a statistically significant difference between the survival rates of patients with diploid and aneuploid patterns. Chemosensitivity was determined by exposing fresh tumor material to five antitumor drugs: adriamycin (ADM), cisplatin (CDDP), carboquone (CQ), 5-fluorouracil (5-FU) and mitomycin C (MMC). The average decrease in succinate dehydrogenase (SD) activity was 49.8% with ADM, 33.6% with CDDP, 39.9% with CQ, 68.4% with 5-FU and 45.5% with MMC. Histologically, poorly-differentiated squamous cell carcinomas were most sensitive to these five antitumor drugs. We also compared average SD activity in tumors from different organs and found that pharyngeal tumors tend to be most sensitive to these drugs, except for MMC. The chemosensitivity of a tumor with DNA diploidy tended to be higher among well- and moderately-differentiated squamous cell carcinomas. In contrast, tumors with DNA aneuploidy tended to have higher chemosensitivity in the poorly-differentiated type. The results of this study indicate that simultaneous analysis of DNA ploidy and chemosensitivity will be helpful in understanding the characteristics of tumors as well as in predicting the most effective chemotherapy agents for head and neck cancer patients.

Adult↗
PubMed1994

[Analysis of nuclear DNA heterogeneity of the hepatocellular carcinoma (HCC)].

To evaluate the objective proliferative activity in HCC nuclear DNA contents were measured by means of microspectrophotometry and at the same time the immunohistochemical technique using anti-PCNA antibody was employed. Surgically resected 26 HCCs were analyzed in terms of cell proliferative activity and regional heterogeneity. The analysis was performed by immunohistochemical demonstration of PCNA and pathologic histochemical study in formalin-fixed, paraffin-embedded specimens and cytophotometric measurements of nuclear DNA contents in fresh specimens. The results were as follows. 1) Nine HCCs showed regional ploidy heterogeneity. 2) PCNA labeling index and histological grade of the marginal area was much higher than that of the central area. From these results, we concluded that in the process of the HCC progression proliferative activity was decreased in the central area and was not decreased in the marginal area.

Carcinoma, Hepatocellular↗
PubMed1994

[The effects of cerebral metabolic activator and vasodilator on cochlear blood flow].

We investigated the effects of intravenous injections of bifemelane hydrochloride, nicergoline and trapidil on cochlear blood flow (CoBF) and cerebral blood flow (CBF) using laser Doppler flowmetry, while monitoring arterial blood pressure (BP), in 40 guinea pigs. Each animal was anesthetized with 40mg/kg of intraperitoneal pentobarbital sodium. After tracheotomy, the animals were artificially ventilated with a respirator. The left middle ear was approached ventrally and the bulla was opened. The middle ear mucosa over the bony cochlea was removed. The tip of the probe was placed on the curvature of the basal or second turn of the cochlea, connecting it to a laser Doppler flowmeter. For the measurement of CBF, part of the parietal bone was exposed. The tip of the probe connected to a laser Doppler flowmeter was placed over the area. A catheter was inserted into the right carotid artery and connected to a pressure transducer. Another catheter for drug administration was cannulated via the jugular vein. Of 40 animals, 22 animals were given bifemelane hydrochloride, 10 animals received nicergoline and 8 animals were given trapidil. The drugs were administered in increasing concentrations, by intravenous injection, for 1 min at intervals of about 20 min in a volume equivalent to 1ml/kg. Asphyxia was induced by stopping the respirator for 2min before and after the experiment. CoBF, CBF and BP were simultaneously recorded. CoBF, CBF and BP rose after bifemelane hydrochloride administration. Nicergoline injection slightly decreased BP, but CoBF and CBF were unchanged. Trapidil injection slightly decreased BP and CBF, but increased CoBF at some concentrations. The high concentration injections of all drugs resulted in increases in normalized cochlear blood flow (CoBF/BP; nCoBF). After asphyxia, CoBF, nCoBF, CBF and BP tended to reach high levels in guinea pigs pretreated with bifemelane hydrochloride, as compared with untreated animals. While administration of nicergoline and trapidil exerted no influence on the changes caused by asphyxia in CoBF, nCoBF, CBF and BP. In this experiment, BP, CoBF and CBF responded in various ways to the three drugs tested, but analysis of nCoBF indicated that these drugs had a vasodilatory effect in the cochlea.

Animals↗
PubMed1994

Evaluation of masticatory function after sagittal split ramus osteotomy for patients with mandibular prognathism.

The aim of this study was to measure the changes in masticatory function for 1 year after sagittal split ramus osteotomy. Thirty prognathic patients who underwent preoperative and postoperative orthodontic treatment participated in this study. Their masticatory performance, occlusal contact area and points, and biting force were measured before surgery and 3, 6, and 12 months postoperatively. From 3 months after surgery, masticatory efficiency was greater than that found preoperatively, and the increase was significant 6 months after surgery. Occlusal contact area and points tended to increase from 3 months after surgery, and there was a significant increase 12 months after surgery. The bilateral biting force was lower 3 months after surgery than it was preoperatively, but it had increased significantly and was balanced on left and right sides 12 months after surgery.

Adolescent↗
PubMed1994

Pharmacological evidence for regulation of Na(+)-Ca++ exchange by Ca++/calmodulin-dependent protein kinase in isolated bovine adrenal medullary cells.

The mechanism of the regulation of Ca++ influx via Na(+)-Ca++ exchange in response to Na+ deprivation was studied in bovine adrenal medullary cells. Protein kinase inhibitors staurosporine and (8R*,9S*,11S*)-(-)-9-hydroxy-9-methoxycarbonyl-8-methyl2,3,9,10-te trahydro-8, 11-epoxy-1H,8H, 11H-2,7b, 11a-triazadibenzo[a,g]cycloocta[c,d,e]trinden- 1-one depressed Na+ deprivation-induced 45Ca++ uptake and catecholamine secretion in a concentration-dependent manner. However, 1 mM dibutyryl cyclic AMP and 1 microM forskolin, an activator of adenylate cyclase, had little effect on Na+ deprivation-induced 45Ca++ uptake and catecholamine secretion. Dibutyryl cyclic GMP (1 mM) and muscarine (30 microM), which increased intracellular cyclic GMP level via stimulation of muscarinic receptors, had also little effect on the responses. Although the phorbol esters 12-O-tetradecanoyl-phorbol-13-acetate and phorbol 12,13-dibutyrate, activators of protein kinase C, enhanced Na+ deprivation-induced catecholamine secretion, these compounds failed to affect Na+ deprivation-induced 45Ca++ uptake. On the other hand, a variety of calmodulin antagonists such as calmidazolium, trifluoperazine, pimozide and N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide inhibited Na+ deprivation-induced 45Ca++ uptake and catecholamine secretion in a concentration-dependent manner. Furthermore, 1-[N,O-bis(5-isoquinolinesulfonyl)-N-methyl-L-tyrosyl]-4-phenylpipera zin e, which is known as an inhibitor of Ca++/calmodulin-dependent protein kinase II, also reduced Na+ deprivation-induced 45Ca++ uptake and catecholamine secretion. Chelation of intracellular Ca++ with Quin-2 acetoxymethyl ester resulted in a decrease in Na+ deprivation-induced 45Ca++ uptake. However, these compounds that inhibited the Na+ deprivation-induced responses in the cells did not cause solely nonspecific and direct inhibition on Na(+)-Ca++ exchanger. These pharmacological observations suggest that Ca++/calmodulin-dependent protein kinase is involved in the regulation of Na(+)-Ca++ exchange in bovine adrenal medullary cells.

Adrenal Medulla↗
PubMed1994

[Basic and clinical evaluation of the effect of pirarubicin against head and neck cancer--chemosensitivity test and a comparative study with doxorubicin].

The chemosensitivities of 77 samples of human head and neck cancer were examined by in vitro succinate dehydrogenase inhibition (SDI) test. The tumor tissues obtained at biopsy specimens were exposed to doxorubicin (DXR) and pirarubicin (THP). The average decrease of the enzyme activity by THP was significantly greater than that by DXR. In 60 cases of squamous cell carcinomas, the chemosensitivity of poorly differentiated type tended to be higher compared to the well differentiated type. It is suggested from there results that THP is a more effective anticancer drug than DXR against human head and neck cancers. Clinically good responses were obtained in a systemic chemotherapy of such as head and neck adenoid cystic carcinomas by combining THP with other anticancer drugs such as CDDP (or CBDCA) and CPA.

Adult↗
PubMed1994

[The CCG1 gene].

Explore the source record for details and available documents.

Animals↗
PubMed1994

Clinical features of infants with primary human herpesvirus 6 infection (exanthem subitum, roseola infantum).

OBJECTIVE: To clarify clinical features of patients with primary human herpesvirus 6 (HHV-6) infection (roseola infantum, exanthem subitum) in a large-scale study. SUBJECTS AND METHODS: Clinical signs and symptoms were analyzed in 176 infants in whom exanthem subitum was initially suspected and primary HHV-6 infection was later confirmed. The infection was proved by isolation of the virus from blood, a significant increase in the neutralizing antibody titers to the virus, or both. RESULTS: The primary HHV-6 infection, which occurred throughout the year, was observed in 94 boys and 82 girls (mean age, 7.3 months). Fever developed in 98% (mean maximum fever, 39.4 degrees C) and lasted for 4.1 days. Macular or papular rashes appeared in 98%, on face, trunk, or both, mostly at the time of subsidence of the fever, and lasted for 3.8 days. Other clinical manifestations occurred as follows: mild diarrhea in 68%, edematous eyelids in 30%, erythematous papules in the pharynx in 65%, cough in 50%, and mild cervical lymph node swelling in 31%. Twenty-six percent had bulging of the anterior fontanelle and 8% had convulsions. CONCLUSIONS: Clinical features of patients with virologically confirmed exanthem subitum were comparable with those described before discovery of HHV-6.

Exanthema Subitum↗
PubMed1993

The presence of corticotropin-releasing factor-like immunoreactive synaptic vesicles in axon terminals with nicotinic acetylcholine receptor-like immunoreactivity in the median eminence of the rat.

Whether or not corticotropin-releasing factor (CRF) containing synaptic vesicles are located in axon terminals with nicotinic acetylcholine receptor (nAChR) in the median eminence (ME) of the rat was examined by electron microscopic double-labeling immunocytochemistry combining the pre-embedding avidin-biotin-peroxidase complex (ABC) method for nAChR with the post-embedding immunogold staining method for CRF. nAChR-like immunoreactivity (nAChR-LI) was found in the cell membranes of the axon terminals in the ME. CRF-like immunoreactivity (CRF-LI) was found in dense granular vesicles (about 100 nm in diameter) in the axon terminals. Double-labeling method revealed that some of nAChR-LI axon terminals were found to contain CRF-LI dense granular vesicles. The results indicate that nicotine may act on nAChR in axon terminals to release CRF.

Animals↗
PubMed1993

Immunocytochemical localization of nicotinic acetylcholine receptor in rat hypothalamus.

Immunocytochemical localization of neuronal nicotinic acetylcholine receptor (nAChR) was examined in rat hypothalamus. Monoclonal antibody against alpha 4 ACh-binding subunits of nAChR was used in the avidin-biotin-peroxidase complex (ABC) immunocytochemical method at both the light and electron microscopic levels. By light microscopy nAChR-like immunoreactivity was found in many neuronal cell bodies and their fibers in the paraventricular nucleus (PVN) and in many axons and axon terminals in the median eminence (ME). The immunoreactivity of nAChR was the most intense in the ME. By electron microscopy immunoreaction products occurred on the rough endoplasmic reticulum, nuclear envelope, cytoplasmic matrices and postsynaptic densities of synaptic junctions in some neurons in the parvocellular part of the PVN. In the external layer of the ME, nAChR-like immunoreactivity was found over the entire plasma membranes of many axon terminals. Involvement of nAChRs in the release of neurotransmitters and neuropeptides both in the PVN and the ME is discussed.

Animals↗
PubMed1993

Nicotine metabolism by rat hepatic cytochrome P450s.

Many kinds of cytochrome P450s were purified from rat hepatic microsomes, and their role in the metabolization of nicotine in a reconstituted system examined. Of four phenobarbital-inducible P450s, P450 2B1 had the highest nicotine oxidation activity and P450 2B2 showed a low rate of nicotine oxidation, whereas P450 2C6 and 3A2 had no detectable activity toward nicotine. Among eleven other purified cytochrome P450s tested, P450 2C11 had high nicotine oxidation activity and P450 1A2 and 2D1 showed low catalytic activity toward nicotine. The other cytochrome P450s, P450 1A1, 2A1, 2A2, 2C7, 2C12, 2C13, 2E1 and 4A1, had no detectable nicotine oxidation activity. Based on these results, participation of cytochrome P450s in nicotine metabolism in human and animal livers is discussed.

Animals↗
PubMed1993

Clinical and virological analyses of 21 infants with exanthem subitum (roseola infantum) and central nervous system complications.

Twenty-one infants who had virologically confirmed exanthem subitum and central nervous system (CNS) complications were studied to elucidate the clinical features, laboratory and virological findings, and outcome. The primary infection with human herpesvirus 6 was confirmed by isolation of the virus from blood, a significant rise in the antibody titers to the virus, or both. All convulsive seizures (15 generalized and 6 focal) occurred during the pre-eruptive stage of exanthem subitum. Four infants with encephalitis/encephalopathy had more severe clinical features with abnormalities demonstrated on electroencephalograms and cerebral computed tomograms. All infants except those with encephalitis/encephalopathy recovered without any sequelae. One infant with encephalitis/encephalopathy developed epilepsy and another one died. Human herpesvirus 6 DNA amplified by the nested polymerase chain reaction method was detected in the cerebrospinal fluid of 6 infants, including 3 with encephalitis/encephalopathy, of 11 patients examined by the fifth day of the illness. These findings suggest that CNS complications including encephalitis/encephalopathy occur at the pre-eruptive stage of exanthem subitum, that human herpesvirus 6 invades the CNS in some patients, and that the outcome is not always benign.

Base Sequence↗
PubMed1993

Seroepidemiology of human herpesvirus 7 in healthy children and adults in Japan.

The isolation of human herpesvirus 7 (HHV-7) from saliva and blood, and the prevalence of antibodies to the virus in healthy individuals were investigated in Japan. By cocultivating samples with phytohemagglutinin-P-stimulated cord blood mononuclear cells, HHV-7 was isolated from the saliva of 1 of 20 children and from 4 of 38 adults but not from their blood. The isolates were confirmed as closely related to RK strain of HHV-7, but not to U1102 (human herpesvirus 6, HHV-6 type A) or Z29 (HHV-6 type B) strains by restriction cleavage patterns of the DNA. The virus antibody of 330 healthy children and adults was measured with an indirect immunofluorescence assay, using one of our isolates (FG7-6). The positivity rate of antibody was 40% in the first 2 months of life, declined during the first 6 months, then gradually increased and was 45% at 1-4 years of age. It reached the highest level (60%) at 11-13 years of age and was maintained until the end of the third decade, then decreased thereafter. Additionally, no simultaneous rise in the antibody titers was observed in 7 virologically confirmed exanthem subitum patients.

Adolescent↗
PubMed1993

Effects of increased cerebrospinal fluid pressure on cochlear and cerebral blood flow.

We investigated the effects of increased cerebrospinal fluid (CSF) pressure on cochlear blood flow (CoBF) and cerebral blood flow (CBF) in guinea pigs. CoBF and CBF were recorded simultaneously using two laser-Doppler flowmeters, and blood flow volume in each part of the cochlea and the brain was measured by the non-radioactive microsphere method. CoBF was reduced by increased CSF pressure but the reduction was not persistent. Although inner ear pressure was elevated to the same level as CSF pressure, CoBF was not decreased by the pressure elevation as much as was CBF. Our results suggest that CoBF is relatively resistant to increases in CSF pressure.

Animals↗
PubMed1993

Effect of trimebutine maleate on emptying of stomach and gallbladder and release of gut peptide following a solid meal in man.

We investigated the effect of orally administered trimebutine maleate on gastric and gallbladder emptying and on the release of gut peptide, pancreatic polypeptide (PP), and gastrin in humans for 120 min after ingestion of a solid meal. Gastric emptying was measured by a radionuclide technique. Gallbladder emptying was estimated by real-time ultrasonography. The oral administration of 200 mg of trimebutine maleate significantly shortened the lag time in starting gastric emptying (P < 0.05). Considering gallbladder emptying, trimebutine significantly inhibited the fasting emptying induced by neural reflex. Postprandially, there was a tendency toward an accelerated gallbladder emptying in the early phase. Neither the maximal percentage of gallbladder emptying nor the time of peak gallbladder emptying were affected. Trimebutine significantly blunted the post-prandial PP response in the cephalic and gastric phases, reflecting a vagal-cholinergic activity (P < 0.05). The PP response in the intestinal phase was also blunted. Gastrin release was significantly augmented only during the period of fasting after drug administration (P < 0.05). The major effect of trimebutine maleate appears to be a shortening of the lag time at the start of gastric emptying probably via its anticholinergic activity.

Administration, Oral↗
PubMed1993

An anatomic study on the Martin-Gruber anastomosis.

The incidence of Martin-Gruber anastomosis was studied. Anatomical dissection of 108 cadaveric arms was performed. The Martin-Gruber anastomosis was found in 23 arms. This anastomosis was classified into four types: Type Ia: Communication between the anterior interosseous and the ulnar nn. (n = 13), Type Ib: Communication between the median and ulnar nn. (n = 1), Type II: Communication between muscular branches of the flexor digitorum profundus m. (n = 8), Type III: Combination of Type Ia or Ib and Type II (n = 1). The incidence of Martin-Gruber anastomosis was found to be significantly higher in the present study than in previous studies.

Dissection↗