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Biomedical subjects

Y Munemoto

Publications and source records attributed to Y Munemoto.

16 recordsLinked to original sources
PubMed2001

Brainstem auditory regions in mice: expression of nociceptin/orphanin FQ precursor mRNA in select neurons.

Nociceptin peptide-receptor system is known to be essential for the regulation of hearing ability. The mRNA for nociceptin precursor protein is highly expressed in the brainstem. We explored a detailed hybridohistochemical expression pattern of the nociceptin precursor mRNA in the mouse brainstem, and identified positive cells in several auditory brainstem nuclei. Positive cells were seen in the dorsal and ventral nuclei of the lateral lemniscus, the rostral periolivary region, the lateroventral and medioventral periolivary nuclei, the dorsal periolivary region, the superior paraolivary nucleus, and the external cortex and dorsal cortex of the inferior colliculus. Of these, the medioventral and lateroventral periolivary nuclei, the major sites of origin of olivocochlear bundle, were most populated by positive cells.

Animals↗
PubMed2001

Roles of the glutamate receptor epsilon2 and delta2 subunits in the potentiation and prepulse inhibition of the acoustic startle reflex.

We examined the regulation of the acoustic startle response in mutant mice of the N-methyl-D-aspartate (NMDA)- and delta-subtypes of the glutamate receptor (GluR) channel, which play important roles in neural plasticity in the forebrain and the cerebellum, respectively. Heterozygous mutant mice with reduced GluRepsilon2 subunits of the NMDA receptor showed strongly enhanced startle responses to acoustic stimuli. On the other hand, heterozygous and homozygous mutation of the other NMDA receptor GluRepsilon subunits exerted no, or only small effects on acoustic startle responses. The threshold of the auditory brainstem response of the GluRepsilon2-mutant mice was comparable to that of the wild-type littermates. The primary circuit of the acoustic startle response is a relatively simple oligosynaptic pathway located in the lower brainstem, whilst the expression of GluRepsilon2 is restricted to the forebrain. We thus suggest that the NMDA receptor GluRepsilon2 subunit plays a role in the regulation of the startle reflex. Ablation of the cerebellar Purkinje cell-specific delta2 subunit of the GluR channel exerted little effect on the acoustic startle response but resulted in the enhancement of prepulse inhibition of the reflex. Because inhibition of the acoustic startle response by a weak prepulse is a measure of sensorimotor gating, the process by which an organism filters sensory information, these observations indicate the involvement of the cerebellum in the modulation of sensorimotor gating.

Acoustic Stimulation↗
PubMed1998

Auditory pathway and auditory brainstem response in mice lacking NMDA receptor epsilon 1 and epsilon 4 subunits.

There is considerable evidence that the N-methyl-D-aspartate receptor (NMDAR) is a component of excitatory amino acid synapses in the ascending auditory pathway. The availability of mice that are defective in NMDAR epsilon 1 or NMDAR epsilon 4 subunit paves the way for investigations on the role of this receptor in auditory function. Non-radioactive in situ hybridization was used in the parent C57/6J wild strain to determine if these subunits are normally expressed in cochlear nucleus (CN) and superior olivary complex (SOC) and to confirm their absence in the respective mutant mice. Evoked auditory brainstem response (ABR) to normal acoustic stimulation was investigated to assess function. In situ hybridization revealed the expression of NMDAR epsilon 1 and epsilon 4 subunits mRNAs in major neuronal types in the CN and SOC of the wild type mice while epsilon 1 and epsilon 4 expression were absent in their respective mutant mice. The ABR threshold for the epsilon 1 mutant mice was similar to that of wild type mice however the threshold for the epsilon 4 mutant mice was significantly elevated. These results suggest a role for the NMDAR epsilon 4 in normal auditory functions while the NMDAR epsilon 1 may have a less critical function under normal conditions.

Animals↗
PubMed1995

Clinicopathologic studies of immunologic fecal occult blood test for colorectal cancer.

In our hospital, 83 patients with colorectal cancer underwent the immunologic fecal occult blood test (IFOBT). The positive rate for IFOBT in all patients was 87%. Colon cancers more proximal than the transverse colon were 100% positive. Carcinomas of the ulcerative type showed a significantly higher positive rate than those of the non-ulcerative type (94% vs 73%). Carcinomas penetrating the muscularis or beyond showed a significantly higher positive rate, of 96% (52/54 cases) compared to carcinomas confined to the mucosa or submucosa, which gave positive rates of 64% and 60%, respectively. In the investigation of the 7 patients with colorectal cancer who showed negative results on the IFOBT, IFOBT had been performed only once in of these patients. Accordingly, it was considered necessary to perform IFOBT more than once. The cancers in 5 of these 7 patients were found to be carcinomas confined to the mucosa. This result suggests the advisability of annual IFOBTs. It is also considered necessary to manage patients who show undefinable but possibly positive (+/-) results with caution.

Carcinoma↗
PubMed1994

Endoscopic resection of large colorectal polyps using a clipping method.

PURPOSE: In conventional endoscopic snare polypectomy, bleeding and perforation are the principal concerns. To prevent these complications, we employ an endoscopic clipping technique using the HX-3L clipping apparatus. METHODS: With this method, clips are used to clamp the base of a polyp. A snare is hung peripheral to the clips. The polyp is then resected by coagulating and cutting with an electric current. RESULTS: Neither bleeding nor perforation during or after polypectomy has occurred, nor have complications related to the use of clips developed. Gigantic polyps were not resected piecemeal, but rather were resected en bloc facilitating a clear determination of cancer on the surface of the resected site. Endoscopic clipping permitted site marking for colonoscopic surveillance. CONCLUSION: We conclude that the clipping method has many advantages and is a useful technique in colonoscopic polypectomy.

Adult↗
PubMed1992

[Experimental studies on the development of acute gastric lesions induced by vibration stress in rats and its pathogenetic mechanisms].

To clarify the pathogenetic mechanisms in acute gastric lesions induced by vibration (VIB), the effects of VIB (3.0 G, 10 Hz, 90 min) on changes in gastric mucosal blood flow (GMBF), plasma corticosterone (COR) and catecholamines (CA) as well as ulcer formation were compared with those of forced water immersion stress (FWI). While the VIB increased the GMBF during the exposure, the FWI decreased it during and after the stress. No difference in the severity of ulcer formation between the VIB groups was seen. Although both VIB and FWI increased the COR and CA, the degree of increased in the COR by the VIB tended to be less than that by the FWI. The truncal vagotomy inhibited the reduction of the GMBF and ulcer formation by the FWI, but promoted the reduction of the GMBF by the VIB. These results suggest that ulceration induced by VIB is caused primarily by its direct, mechanical and specific actions and not through the central nerve system.

Animals↗
PubMed1990

[A study on pre-operative administration of 5'-DFUR in carcinomas of the gastric, breast, thyroid and colon].

Pre-operative chemotherapy for 7 days with 5'-DFUR (p.o.) were carried out in the patients with gastric, breast, thyroid and colon cancers. The concentration of 5-fluorouracil (5-FU) in tumor cells was higher than that in the normal tissue. In case of breast cancer, it was 10 times higher than normal tissue. The concentration of 5-FU at the metastatic lymph nodes in gastric cancer was considerably high. The pattern of DNA histogram changed when chemotherapy was applied, and we observed the G2 and M phase block.

Antineoplastic Agents↗
PubMed1989

[Comparative study of tegafur (p.o.) and mitomycin C (MMC) plus tegafur in cases of unresectable gastric cancer].

Sixteen cases of gastric cancer with liver metastases (H2 less than) as group A, fifteen with distant peritoneal metastases (P2 less than) as group B, twenty-five with distant lymph nodes metastases (N3 less than) as group C, twenty-eight with two prognostic factors as group D, and seven with three factors as group E were treated. A1, B1, C1, D1 and E1 groups were treated with mitomycin C (MMC) (4 mg) + tegafur (FT) (400 mg) (i.v.-weekly) and A2, B2, and C2 group with FT (600 mg) (p.o.-daily). Partial response in the evaluable cases was found in 7 cases and a total response rate was 11.7%. The 50% survival interval was as follows; 8.5 months (M) in A1 group, 10.0 M in A2, 7.2 M in B1, 2.3 M in B2, 10.4 M in C1, 14.2 M in C2, 5.2 M-7.2 M in D1, and 3.1 M in E1. In the cases with H2 less than or N3 less than, FT (p.o.) and with P2 less than, MMC + FT (i.v.) were effective respectively. Chemotherapeutic effect was better in A1 and A2 group from the aspects of prognostic factors and in the cases of poorly differentiated adenocarcinoma from histological types than in B1 and B2 group and well or moderately differentiated adenocarcinoma.

Adenocarcinoma↗
PubMed1989

[A case report of a giant cell carcinoma of the thyroid].

Discussed is a case of a giant cell carcinoma that presented a high value of serum thyroglobulin. Histopathologically, this tumor had been diagnosed as being an anaplastic carcinoma that had transformed from a differentiated carcinoma, with calcification that was thought to have occurred from a preceding adenoma. To study the possibility of a malignant transformation, an immunohistochemical study of a specimen confirmed the production of thyroglobulin and vimentin, though the specimen stained negatively for keratin.

Aged↗
PubMed1989

[Two cases of leiomyosarcoma of the duodenum].

Two cases of a leiomyosarcoma of the duodenum are reported. The first patient, a seventy-year-old woman, had experienced repeated instances of melena. She was diagnosed as having a leiomyosarcoma of the duodenum preoperatively, and was successfully given a pancreatoduodenectomy. The second patient, a fifty-one year-old woman, also had experienced instances of melena. Similarly, she was diagnosed an having leiomyosarcoma of the duodenum preoperatively, and was given a partial gastrectomy. A pathological examination showed little mitosis in either patient. The first patient is still alive three months after the operation, and the second patient also has been surviving for twelve years postoperatively.

Aged↗
PubMed1988

[Clinicopathological study of early multicentric gastric carcinomas].

During a two-year period, from August, 1983 to July, 1985, 144 gastric cancer patients have been treated at the National Tohsei Hospital. Among them, 57 patients were determined as having an early gastric carcinoma. Four patients (7.0%) of this number were found to have a multicentric type, 3 manifesting a double II c type, and 1 patient having both a I type and II a type. Pathologically these two types carcinomas were found in only one patient, in a so-called kissing position.

Adenocarcinoma↗