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Biomedical subjects

H Miyahara

Publications and source records attributed to H Miyahara.

At least 73 records · Page 4Linked to original sources
PubMed1994

[Aberrant expression of carbohydrate antigens in squamous cell carcinoma of the tongue].

An immunohistochemical study was performed to observe the aberrant expression of blood-related group antigens in squamous cell carcinomas of the tongue from 10 patients and 13 normal tongue tissues using seven monoclonal antibodies, A, B, H, X001, H001, Lea and Leb, and four lectins, PNA, VVA-B4, UEA-1 and LTA. In SCC, Leb antigens were expressed in all cases examined (10 cases). T and Tn antigens which were examined with PNA and VVA-B4 stains, were expressed in seven out of 10 and six out of 10 cases, respectively, while these two antigens were not found in normal tissues. A, B and H antigens were expressed in most normal tongue epithelial cells, strictly dependent on the patient blood type. But in SCC, A and B antigens were not detected in five out of seven cancer cells from blood group A, B and AB individuals, whereas H antigen was expressed in 5 out of 7 cancer cells from blood group A, B and AB individuals. These results suggest that the expression of blood group-related antigens in suppressed to that of more immature carbohydrate chains in the setting of tongue cancer.

Adult↗
PubMed1994

5-Hydroxytryptamine-2 and -4 receptors located on bovine isolated mesenteric lymphatics.

Effects of 5-hydroxytryptamine (5-HT) agonists were investigated in the bovine isolated mesenteric lymphatics, and then the 5-HT receptor subtypes in the responses were pharmacologically classified by use of several 5-HT antagonists. Addition of 5-HT and that of alpha-methyl-5-hydroxytryptamine (alpha-methyl-5-HT) both produced concentration-dependent contractions in the presence of 3 x 10(-6) M [(1 alpha H, 5 alpha H)-8-methyl-8-azabicyclo(3.2.1)oct-3 alpha-yl]1H-indole-3-carboxylate hydrochloride, whereas 5-carboxamidotryptamine (5-CT) and 2-methyl-5-hydroxytryptamine (2-methyl-5-HT) caused no, or only slight, contraction in the lymphatics. Pretreatment with ketanserin caused a significant shift to the right in the concentration-response curve for 5-HT or alpha-methyl-5-hydroxytryptamine. Schild plot analyses showed that the pA2 values for ketanserin against 5-HT and alpha-methyl-5-hydroxytryptamine were 8.75 and 8.68, respectively. In contrast, 5-CT, 5-HT and metoclopramide caused concentration-dependent relaxations in the presence of 10(-6) M ketanserin in the lymph vessels after contraction with prostaglandin F2 alpha. 2-Methyl-5-HT up to 10(-4) M did not produce any relaxation. High concentrations of [(1 alpha H, 5 alpha H)-8-methyl-8-azabicyclo(3.2.1)oct-3 alpha-y1]1H-indole-3-carboxylate hydrochloride induced a significant inhibition of the 5-CT- and 5-HT-induced relaxation, but methiothepin and methysergide up to 10(-6) M and mechanical rubbing of the endothelium had no significant effect on the relaxation.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

The effects of recombinant human granulocyte colony-stimulating factor on passive collagen-induced arthritis transferred with anti-type II collagen antibody.

Type II collagen-induced arthritis (CIA) is a pathologic process mediated, in part, by humoral immune mechanisms. Because many antibody-mediated reactions are neutrophil-dependent, the role of this cell population was examined in passive CIA transferred with anti-type II collagen (CII) antibody. In cyclophosphamide (CY)-induced leukocytopenic rats, swelling and inflammation associated with the arthritic response were significantly reduced. Concomitant administration of recombinant human granulocyte colony-stimulating factor (rhG-CSF) to leukocytopenic rats for 7 consecutive days from the day of CY injection resulted in the recovery of peripheral blood neutrophils count and the abrogation of the suppression of arthritis with an optimal dose of anti-CII antibody. Further study demonstrated that a prior administration of rhG-CSF to naive rats for five consecutive days resulted in the significant and specific increase of peripheral blood neutrophils count and enhancement of passive arthritis with a suboptimal dose of anti-CII antibody. It was suggested that neutrophils played an important role in the development of passive CIA.

Animals↗
PubMed1993

Successful long-term storage of rat limbs. The use of simple immersion in Euro-Collins solution.

The effect of simple cold storage in Euro-Collins solution on prolonging successful preservation time was examined on an established rat limb transplant model. Limbs amputated at mid-thigh level were simply immersed in the solution and stored in a refrigerator at 4 degrees C. After varying periods of cold storage, the limb was orthotopically grafted to another isogeneic rat using microsurgical techniques. The survival rates for 12, 24, 48 and 72 hours' storage were 100%, 90%, 67% and 50% respectively, and the longest time of successful preservation achieved was 78 hours. Survival rates were greatly decreased when amputated limbs were initially perfused with Euro-Collins solution and immersed in the same solution. In a third set of experiments, the limbs were preserved by a conventional method of cold storage in air, and the survival rates were decreased even further. Evaluation by measuring postoperative paw swelling and microscopic examination of the grafts further confirmed the effectiveness of the simple immersion method without perfusion.

Amputation, Surgical↗
PubMed1993

Cellular mechanisms of the steroid-induced vascular responses in the rabbit ear artery.

1. In anesthetized rabbits, topical application of dexamethasone to the ear produced an initial vasodilation followed by a vasoconstriction with long delay (120 min). Diphenhydramine inhibited the former, but not the latter. 2. In isolated rabbit ear arteries, dexamethasone reduced the amplitude of contractions of smooth muscles produced by nerve stimulation, noradrenaline and high-K solution, only at high concentrations (> 10(-5) M). 3. The initial vasodilation induced by topical application of dexamethasone may be related to endogenous histamine, while the delayed constriction response may not be direct actions of steroid to smooth muscles.

Acetylcholine↗
PubMed1993

[Immunohistochemical study of epidermal growth factor receptor and estrogen receptor in human thyroid tumors].

Expressions of epidermal growth factor receptor (EGFR) and estrogen receptor (ER) in human thyroid tumors were examined immunohistochemically in frozen sections. Forty-eight fresh surgical specimens of thyroid tissues, 19 carcinomas, 12 adenomas, 7 adenomatous goiters and 10 normal thyroid tissues were studied. All cases, including normal thyroid tissues, expressed the EGFR immunoreaction in the cytoplasm. Incidences of stronger than (+) staining intensity of EGFR were 84% (16/19) in carcinoma, 67% (8/12) in adenoma, 57% (4/7) in adenomatous goiter and 30% (3/10) in normal thyroid tissue. This result suggests that the staining intensity of EGFR expression is associated with malignant potential. The frequency of ER positive cases was 11% (2/19) in carcinoma, 17% (2/12) in adenoma and 0% in both adenomatous goiter and normal thyroid tissue. No relationship between EGFR and ER expression was recognized. However, a case of papillary carcinoma with strong ER immunoreactive intensity expressed weak EGFR intensity, suggesting an inverse relation in immunoreaction between EGFR and ER in papillary carcinoma.

Adenoma↗
PubMed1992

Comparative study of effects of cyclosporins A and G on collagen arthritis in mice.

The effects of the immunosuppressive agents cyclosporin G (CsG) and cyclosporin A (CsA) on collagen arthritis were compared in mice. When administered subcutaneously daily on days 0-13 after immunization with type II collagen, CsG and CsA were both capable of suppressing the development of collagen arthritis in mice as well as the immunological response to native type II collagen in a dose-dependent manner. Histopathologically, no marked inflammatory lesions were observed in diarthroidal joints from mice treated with 100 mg/kg per day of CsA or 800 mg/kg per day of CsG. However, an analysis of dose response showed CsG to be 8 times less potent than CsA in inhibiting the development of arthritis.

Animals↗
PubMed1992

Evaluation of five computer programs in the diagnosis of second-degree AV block.

Five electrocardiogram (ECG) analyzing systems were tested with a microcomputer-based ECG signal generator to assess the accuracy of the systems in interpreting Wenckebach periodicity. Although normal sinus rhythm with normal PR intervals and sinus rhythms with first-degree atrioventricular (AV) block were diagnosed by all five systems, second-degree AV block with classic Wenckebach periodicity was routinely misdiagnosed by four of the five systems. No system recognized the atypical Wenckebach periods in a total of 200 trials, misinterpreting the phenomenon as atrial fibrillation, supraventricular rhythm, sinoatrial block, and other rhythm disturbances. In advanced AV block and a variety of ventricular arrhythmias, none of the five systems diagnosed second-degree AV block with Wenckebach periods. Marked unsatisfactory performance with regard to the diagnosis of Wenckebach periodicity indicates the urgent need for accelerated and comprehensive testing of ECG diagnostic equipment. The present generating device was seen as an effective troubleshooter in optimizing the diagnostic competency of computerized ECG systems.

Computer Simulation↗
PubMed1992

Combination of patch test and IgE for dust mite antigens differentiates 130 patients with atopic dermatitis into four groups.

BACKGROUND: Patients with atopic dermatitis sometimes have positive responses to patch testing (PT) with dust mite antigens, which is believed to correlate with the elevated levels of specific IgE for those antigens. OBJECTIVE: The purpose of this study is to identify the correlation between the PT and serum IgE concerning the mite antigens. METHODS: We studied 130 patients with atopic dermatitis by the PT reaction and the serum level of specific IgE for Dermatophagoides pteronyssinus antigens. RESULTS: Fifty-one of the 130 patients assessed as PT-positive had either high (32 of 130 patients; 24.6%) or low or no (19 of 130 patients; 14.6%) levels of mite-specific IgE; there was a significant difference between the groups with elevated and low IgE. Similarly, a total of 79 PT-negative patients also showed an elevated or low mite-specific IgE (42 of 130 patients [32.3%] or 37 of 130 patients [28.5%], respectively). It was noted that clinical morphologic findings were peculiar to three of the four groups; however, the patients who were PT-negative with a low IgE (37 of 130 patients) showed no particular clinical lesions. CONCLUSION: Comparing the results from our 130 patients, there was no correlation between the serum IgE level and the PT reaction for dust mite antigens. Conversely, the results of PT and mite-specific IgE could be used to divide these patients into four distinct groups, each with its own particular clinical morphology, suggesting the heterogeneity of this disease.

Adolescent↗
PubMed1992

[Effects of sex hormones and propylthioracil on growth of transplantable rat thyroid tumor with estrogen receptor (ER)].

UNLABELLED: Effects of hormones (E2: estradiol, TP: testosterone) and propylthiouracil (PTU) on the growth of transplantable rat thyroid tumor (F2D1) having estrogen receptors were studied. Rat thyroid neoplasms, induced by N-bis (2-hydroxypropyl) nitrosamine, were inoculated subcutaneously from donor to recipient rats, in order to establish 16 transplantable rat thyroid tumor lines. The grafts were used for histological studies and for the assay of estrogen receptor (ER) and androgen receptor (AR). Of these lines, we designated papillary carcinoma, which was positive for ER (N: 12.5fmol/mg protein, Kd: 0.4nM) but negative for AR, as F2D1. For studies on the effects of sex hormones and PTU on the growth of transplantable tumors, the rats which had been inoculated with tumors were divided into the following 8 groups; (1) Intact, (2) PTU, (3) ovariectomy (OV), and (4) OV + E2 for female, and (5) Intact, (6) PTU, (7) castration (CA), and (8) CA + TP for male. RESULTS: The growth rate of F2D1 in female rats was decreased by OV, but no change was observed in OV + E2 as compared with Intact. CA and CA + TP in male rats did not influence the growth rate. PTU produced a significant increase in the growth rate in both sexes. These results demonstrate that estrogen and PTU act on the growth of ER-positive rat thyroid tumors.

Animals↗
PubMed1992

[Flow cytometric analysis of DNA ploidy in nasosinal papilloma].

Using paraffin embedded specimens taken from 32 patients with histologically benign nasosinal papillomas, we conducted nuclear DNA analysis by flow cytometry and studied the biological degree of malignancy in this disease. Aneuploidy, which is frequently observed in malignant tumors was not seen in any of these nasosinal papilloma cases. Age did not affect either S+G2M % or polyploid %, two parameters that reflect cell proliferation capacity. Both parameters, S+G2M % and polyploid %, were higher in inverted papillomas which are more likely to become malignant than epithelial papillomas. In recurrent cases of nasosinal papilloma both S+G2M % and polyploid % were higher than in nonrecurrent cases. Moreover, the polyploid % was significantly different, supporting speculation that this can be used as a parameter for predicting recurrence of nasosinal papilloma.

Cell Nucleus↗
PubMed1991

Comparative studies of the effects of FK506 and cyclosporin A on passively transferred collagen-induced arthritis in rats.

We investigated the effect of a novel immunosuppressive agent, FK506, in comparison with cyclosporin A (CsA) on the development of passive arthritis induced by anti-type II collagen (CII) antisera in rats. FK506 pretreatment shortly before serum transfer markedly suppressed the incidence and the severity of passive arthritis, while CsA pretreatment had no observable effects on this disease when used in doses sufficient to suppress the development of active arthritis induced by CII immunization. In an additional study, we examined whether these agents affect antibody-mediated tolerance induction. CII-specific immunological tolerance was induced by serum transfer, but was unaffected by either FK506 or CsA pretreatment in our regimen. While its precise mechanism of the immunosuppressive activity remains to be elucidated, FK506 can act on the antibody-mediated effector phase of arthritis and may offer new insights into the possible role of potential therapeutic utility in human autoimmune diseases.

Animals↗
PubMed1991

Neurofibroma of the hypopharynx: a case report.

A 45-year-old female patient with a neurofibroma of the hypopharynx is reported. She had complained of swallowing discomfort for 3 months. Indirect laryngoscopy showed an oval tumor with a smooth surface in the posterior wall of the hypopharynx. Xeroradiography was effective for defining the tumor. Removal of the tumor was performed by an infrahyoid horizontal pharyngotomy under general anesthesia. The tumor had an indistinct capsule. The nerve from which the tumor originated was not clear. Histologically, the tumor was diagnosed as neurofibroma. The patient had no other neurogenic tumor and has been well without recurrence after the surgery.

Female↗
PubMed1991

[Flow cytometric analysis of DNA content in paraffin-embedded tissue in head and neck cancer (the second report)--primary lesions of laryngeal cancer].

Flow cytometric analysis of DNA content using paraffin-embedded materials has become an important diagnostic, as well as prognostic, method for clinical pathology and investigative oncology. DNA content as measured in paraffin-embedded materials is closely related with that obtained from fresh specimens. This method also permits retrospective analysis on a lot of cases and studying different specimens of a tumor for intratumor heterogeneity. Flow cytometry was used to investigation of the DNA distribution in biopsy specimens from 30 patients with squamous cell carcinoma of the larynx. These patients had initially treated in our institute in the period from 1986 to 1988 and followed for two to four years. A modification of Hedley's method was used to prepare paraffin-embedded materials. DNA histogram were assessed in terms of DNA index (DI). The coefficient of variation for determination of DI ranged 4.2 to 13.7% (mean 7.8 +/- 2.4%). Using infiltrated lymphocytes and mesenchymal cells as an internal standards, aneuploid DNA histogram were found in 13 of 30 specimens (43.3%). DI ranged from 1.05 to 1.22. There was no significant correlation between DNA content and sex, age, tumor size, staging or treatment. The aneuploidy was found in 2 of 17 cases with well differentiated tumor (11.8%), 10 of 12 with moderately differentiated tumor (83.3%), one with poorly differentiated tumor (100%). 11.8% of patients with diploid tumor cells had recurrence during the interval of observation, compared to 38.5% of those with aneuploid tumor cells (p less than 0.05). In T1 lesions of glottic cancer aneuploid group had a significantly lower local control rate than diploid group (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗