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Biomedical subjects

M Mihara

Publications and source records attributed to M Mihara.

226 records · Page 13Linked to original sources

A case of exaggerated mosquito-bite hypersensitivity with Epstein-Barr virus-positive inflammatory cells in the bite lesion.

We describe a unique patient with mosquito-bite hypersensitivity who had extremely high titres of Epstein-Barr virus antibodies. For many years he developed intractable ulcers on the sites of mosquito-bite. Epstein-Barr virus infection was detected in almost all inflammatory cells in the ulcers and in the peripheral blood lymphocytes by using in situ hybridization to Epstein-Barr virus-encoded small ribonucleic acids and by polymerase chain reaction to Epstein-Barr virus DNA. The inflammatory cells in the ulcers were positive for T-cell marker. Our results suggest that the Epstein-Barr virus infection in T cells may participate in the pathogenesis of exaggerated mosquito hypersensitivity and in delayed healing of ulcers on the sites of mosquito-bite.

Adolescent↗

Familial gastric cancer in the Japanese population is frequently located at the cardiac region.

The clinical features of familial gastric cancer are still unknown. To approach this question, we investigated the clinicopathological characteristics of 16 cases of familial gastric cancer. In this study the criteria used to define familial gastric cancer was the existence of three or more family members with gastric cancer in at least two successive generations. The clinicopathological characteristics of cases who fulfilled this criteria were studied. This study contained 16 familial gastric cancer probands. Seven cases (44%) of gastric cancer had developed at the cardiac region of the stomach. This frequency was significantly higher than for gastric cancer in the general population in Japan (15.4%, p < 0.01). Undifferentiated types were dominant in familial gastric cancer (69%, p < 0.05). Furthermore, the frequency of disseminated peritoneal (40%) and liver metastases (20%) in familial gastric cancer was also significantly higher than for gastric cancer in the general population in Japan (10.9%, p < 0.01, and 4.4%, p < 0.05, respectively). Familial gastric cancers were frequently located at the cardiac region and appeared to be more aggressive than sporadic gastric cancers. The unique characteristics of familial gastric cancer suggest a genetic background in their etiology.

Adult↗

Absence of microsatellite instability and germline mutations of E-cadherin, APC and p53 genes in Japanese familial gastric cancer.

To evaluate the genetic factors of familial predisposition to gastric cancer, genetic alterations in the surgically resected stomach samples from gastric-cancer-prone families were investigated. Familial gastric cancer (FGC) was defined as gastric cancer occurring in a family with 3 or more gastric cancer patients over at least two successive generations. We examined replication error (RER) of six microsatellite markers and screened mutations of the 10-(A) repeat sequence in the transforming growth factor-beta receptor type II (TGF-betaRII) gene in individuals from seven unrelated FGC families. Three cases showed RER at one of the six (CA)n microsatellite markers but the other 4 cases showed no RER at any of these loci. No mutation was found in the 10-(A) repeat of the TGF-betaRII gene. Additionally, no germline mutation was found by polymerase chain reaction-single strand conformation polymorphism in exons 1-16 of E-cadherin, exons 5-8 of p53 and in the mutation cluster region of APC. These results indicate that disorders in the DNA mismatch repair system, E-cadherin, p53 and APC may be infrequently involved in the carcinogenesis of Japanese FGC.

Adenomatous Polyposis Coli Protein↗

Ocular manifestations in patients with microscopic polyangiitis.

PURPOSE: To describe ocular manifestations in patients with microscopic polyangiitis. METHODS: Two patients with microscopic polyangiitis complained of ocular symptoms and underwent ophthalmologic examinations. RESULTS: An 83-year-old woman (Case 1) was diagnosed with microscopic polyangiitis, according to the general clinical findings and the presence of perinuclear pattern of antineutrophil cytoplasmic antibodies (P-ANCA). She had hypopyon iridocyclitis in the right eye and retinal cotton-wool spots in the left eye. The patient was treated with oral prednisolone and subconjunctival betamethasone. The hypopyon iridocyclitis and retinal cotton-wool spots responded. A 79-year-old man (Case 2) had bilateral scleritis. The diagnosis of microscopic polyangiitis was made based on general clinical findings and the presence of P-ANCA. Scleritis was reduced after corticosteroid treatment. CONCLUSIONS: Ophthalmologists should be aware that hypopyon iridocyclitis, cotton-wool spot, and scleritis could occur in patients with microscopic polyangiitis.

Aged↗

Expression of Cu,Zn-SOD, Mn-SOD and GST-pi in oral cancer treated with preoperative radiation therapy.

Radical scavengers play an important role in cancer cells defending themselves against free radicals which occur with irradiation. SOD (Cu,Zn, Mn-) and GST-pi are radical scavengers with an effect on radiation therapy. We investigated the correlation between radiation effects and expression of Cu,Zn-, Mn-SOD and GST-pi in 34 cases of oral cancer, treated with preoperative radiation therapy. In this study, 22 cases out of 34 were classified as effective and 12 cases as non-effective. Expression of Cu,Zn, Mn-SOD and GST-pi were observed in 13 (38.2%), 10 (29.4%) and 20 (58.8%) cases, respectively. Regarding the value of radiation sensitivity from expression of these proteins in the biopsy samples, no significant correlation was found between those expressions and histological effectiveness of preoperative radiation therapy. But interestingly, in 11 out of 12 of the non-effective cases, strong staining of Cu, Zn-SOD and GST-pi were shown at the residual cancer cells after preoperative radiation therapy. These results suggested that the expression of SOD (Cu,Zn-, and Mn-) and GST-pi may be not useful markers for predicting the effects of radiation therapy. However, Cu, Zn-SOD and GST-pi were increased by irradiation and may play an important role in radiation resistance and cancer cell regeneration after radiation therapy.

Adult↗

The influence of blood arterial oxygen condition on the tumor response to preoperative radiation therapy in oral cancer patients.

The relationship between clinicopathological factors and response of radiation therapy in oral squamous cell carcinoma has been studied. It has been suggested that factors such as tumor site, extent and tumor differentiation determine the response to radiation therapy. It is known that oxygenation is related to the therapeutic effects of radiation therapy. However, there are few reports on the relationship between oxygen condition and the response to radiation therapy. The present study was carried out to assess whether any clinicopathological factors, including an evaluation of the oxygen condition can be used to predict the effects of preoperative radiation therapy in oral squamous cell carcinomas. Forty-seven patients with oral cancer treated with external radiation therapy preoperatively were evaluated. There were no significant differences in response to the radiation with respect to age, sex, tumor site, stage, macroscopic shape of tumors, and the histological factors. The hemoglobin (Hb) and arterial oxygen content (CaO(2)) levels of favorable cases (Hb: 14.4 g/dl, CaO(2) 19.1 ml/dl) were significantly higher than those of unfavorable cases (Hb: 11.0 g/dl, CaO(2): 16.1 ml/dl). These findings suggest that oxygen conditions of oral cancer patients predict tumor response to preoperative radiation therapy.

Aged↗

Infrequent alternations of RB pathway (Rb-p16INK4A-cyclinD1) in adenoid cystic carcinoma of salivary glands.

Retinoblastoma (Rb) tumor suppressor genes' products and of the proteins regulating its phosphorylation and function in G1 arrest, p16INK4A and cyclin D1, play important roles in the regulation of the cell cycle. Rb gene inactivation, reflected by the absence of Rb protein expression, has been reported in oral squamous cell carcinomas. p16INK4A is frequently deleted, methylated, or mutated, and cyclin D1 gene amplification in many malignancies including oral squamous cell carcinomas (SCC). These findings suggested that Rb pathway of G1 arrest are the most commonly affected genes in Oral SCC. However, alternation of Rb pathway in salivary gland tumors was not clear. In this study, the expressions of Rb, p16INK4A, and cyclin D1 alternations were analyzed by immunohistochemical assay in 5 specimens of normal salivary glands and twenty-two cases of adenoid cystic carcinomas (ACC). Proliferating cell nuclear antigen (PCNA) labelling index (P.I.) was used for the evaluation of cell proliferation. Rb was consistently expressed in normal salivary glands and ACC. Loss of p16INK4A expression was observed in three cases (13.6%) of ACC. And overexpression of cyclin D1 was observed in four cases (18.2%). The three p16INK4A absent cases were the tumors with predominantly solid pattern and those cases were overexpressed cyclin D1. The cell proliferation activities of p16INK4A absent tumors (P.I. = 24.2 +/- 2.1%) were significantly higher than those of p16INK4A present tumors (P.I. = 10.4 +/- 3.5%) (P < 0.05). Cyclin D1 expression was also related to cell proliferation (P.I. of cyclin D1 negative cases vs. cyclin D1 positive: 10.1 +/- 3.0% vs. 22.6 +/- 3.4%) (P < 0.05). These findings suggested, however, alternations of Rb pathway were infrequent events in ACC of salivary glands and inactivation of p16INK4A, cyclin D1 overexpression may be related to the high cell proliferating activity of ACC.

Adult↗

Testicular malignant lymphoma; imaging and diagnosis.

The sonographic and magnetic resonance imaging findings of three cases of surgically proven malignant lymphoma of the testis were reviewed and their diagnostic implications were evaluated. In all three cases ultrasonography showed striated hypoechoic bands with paralleling hyperechoic lines radiating peripherally from the mediastinum testis. We believe they represented blood vessels. On T1-weighted MR images, the tumor showed homogenous hyperintensity in one case and homogenous isointensity in the other two. On T2-weighted images the tumor showed homogenous hypointensity in two cases and homogenous isointensity in one. After Gd-DTPA administration, the tumor showed homogenous enhancement in two cases and inhomogenous enhancement in one. In two cases there were enhancing striated bands in the tumor. Despite the diffuse infiltration by the tumor, the basic architecture of the testis, epididymis, and spermatic cord was preserved. When MRI and ultrasonography show an infiltrative disease preserving the basic architecture of the testis and ultrasonography presents hypoechoic bands radiating peripherally from the mediastinum testis, a diagnosis of malignant lymphoma should be considered.

Contrast Media↗

In vivo blocking effects of a humanized antibody to human interleukin-6 receptor on interleukin-6 function in primates.

A humanized antibody to human interleukin-6 (IL-6) receptor, MRA, which was constructed by grafting the complementary determining regions, is expected to be useful as a therapeutic agent for IL-6-related diseases, especially multiple myeloma. We examined the ability of MRA to block the in vivo function of IL-6 and its serum concentration profile in primates. Cynomolgus monkeys were intravenously administered with MRA at doses of 0 (vehicle) or 5 mg/kg, then subcutaneously injected with human IL-6 at a dose of 5 micrograms/kg, once a day for 7 days. The injections of IL-6 increased blood platelet counts two-fold and elevated serum C-reactive protein levels to 0.15 to 0.17 mg/ml. These IL-6-induced typical responses were completely inhibited by single pretreatment with MRA. Serum concentrations of MRA were maintained for a long period; some even at one week after administration, were regarded as having sufficient levels to inhibit the myeloma cell growth. These findings suggest that MRA may be effective in the treatment of IL-6-related diseases.

Animals↗