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Biomedical subjects

Y Asano

Publications and source records attributed to Y Asano.

At least 721 records · Page 40Linked to original sources
PubMed1984

Acute and chronic hypotensive effects of nifedipine and niludipine in hypertensive patients with chronic renal failure.

The present study was aimed to evaluate the acute and chronic hypotensive effects of nifedipine (Bay a 1040, Adalat) and niludipine (Bay a 7168) in hypertensive patients with chronic renal failure. 1. The decrease of blood pressure lasted for at least 3 h and maximum decrement was achieved in 60 min (26% decrement, p less than 0.05) after oral administration of nifedipine (10 mg). On the other hand, niludipine (20 mg) caused decrease of blood pressure for at least 4 h and attained maximum decrement in 90 min (13% decrement, p less than 0.05) after oral administration. 2. In chronic studies of both drugs, the maximum decrease of blood pressure (p less than 0.05) was attained after one week and lasted at least 4 weeks. There were no significant changes of pulse rate, body weight and urine volume in both nifedipine and niludipine groups. 3. Nifedipine caused great diurnal or day-to-day fluctuations of blood pressures after chronic administrations. On the other hand niludipine did not cause any significant fluctuations. Any serious complications could not be seen during these studies. In conclusion, these results provide clinical evidence that niludipine could be usefused great diurnal or day-to-day fluctuations of blood pressures after chronic administrations. On the other hand niludipine did not cause any significant fluctuations. Any serious complications could not be seen during these studies. In conclusion, these results provide clinical evidence that niludipine could be useful for treatment of hypertension associated with chronic renal failure. Results also suggest that the optimal efficacy of nifedipine and niludipine in part depends on the specific clinical situation at hand. For example, nifedipine seems to be the drug of choice in hypertensive emergencies when there is a need for rapid lowering of blood pressure.

Adolescent↗
PubMed1984

[Clinical application of a Biballoon indwelling intraluminal shunt system for carotid endarterectomy].

Clinical applications of newly developed shunt system for carotid endarterectomy were described. The shunt is a silicone tube equipped with balloons at both ends (Biballoon indwelling intraluminal shunt). The blood leak from the gap between a shunt tube and the inner wall of the carotid artery is prevented by inflating balloons after shunt insertion. This shunt system was used in seven cases of cerebral infarction resulted from the carotid stenosis and was proved to be more convenient than other known shunts.

Aged↗
PubMed1983

T cell regulation of b cell activation. Cloned Lyt-1+2-T suppressor cells inhibit the major histocompatibility complex-restricted interaction of T helper cells with B cells and/or accessory cells.

The present studies have identified cloned Lyt-1+2- T suppressor (Ts) cells that are both antigen specific and major histocompatibility complex (MHC) restricted in their activation requirements and that function to regulate the MHC-restricted activation of B cells by T helper (Th) cells. ParentA-restricted Ts clones suppressed, in antigen-specific fashion, the responses generated by (A X B)F1 Th cells cooperating with parentA (B plus accessory) cells, but did not suppress responses by the same (A X B)F1 Th cell population cooperating with parentB (B plus accessory) cells. Moreover, responses of (A X B)F1 leads to parentA Th cells and (A X B)F1 (B plus accessory) cells were suppressed by parentA-restricted Ts clones but not by parentB-restricted Ts clones. Thus, these findings suggest that the cloned Ts cells that have been characterized here function by specifically inhibiting the MHC-restricted interaction between Th cells and B and/or accessory cells. It was further demonstrated in experiments using cloned Th and Ts populations that these Lyt-1+2-Ts cells act not simply as inducers of suppressor but rather function in a restricted fashion as effector cells in the suppressor pathway.

Animals↗
PubMed1983

A histopathologic study of benign and malignant lymphoepithelial lesions of the parotid gland.

Twenty-three cases of benign and malignant lymphoepithelial lesions without Sjögren's syndrome were examined: 21 were classical benign lymphoepithelial lesions, and were mostly found in males older than 50 years of age. The other two cases were identified as undifferentiated carcinoma arising from benign lymphoepithelial lesion (8.7%; 2/23). Histologically, this carcinoma is characterized by the formation of cell nests of variable size and by marked lymphoplasmacytic infiltrations into the stromal tissue. In immunofluorescence, an increase of plasma cells containing IgA and IgG was noted in the marginal areas of carcinoma cell clusters. Electron microscopy disclosed that the carcinoma was composed of poorly differentiated cells with occasional squamous differentiation. No dysplastic characteristics were found in the infiltrating lymphocytic components. These two cases of carcinoma were found in middle-aged females.

Adult↗
PubMed1983

T cell regulation of B cell activation. I-A-restricted T suppressor cells inhibit the major histocompatibility complex-restricted interactions of T helper cells with B cells and accessory cells.

The present studies were carried out to characterize the cellular interactions involved in the activation and function of the antigen-specific and antigen-nonspecific T suppressor (Ts) cells that regulate the IgG responses of Lyb-5-B cells. The in vitro activation of both Lyt-1+2- antigen-nonspecific Ts cells and Lyt-1-2+ antigen-specific Ts cells was shown to require the interaction of accessory cells and antigen-primed T cells. It was further demonstrated that this interaction was major histocompatibility complex (MHC)-restricted in that T cell recognition of I-A-encoded determinants on accessory cells was required for Ts cell activation. The activation of antigen-primed (A X B)F1 T cells with antigen in the presence of parentA or parentB accessory cells resulted, respectively, in the generation of parentA-restricted or parentB-restricted Ts cells. ParentA-restricted F1 Ts cells suppressed the responses generated by (A X B)F1 T helper (Th) cells cooperating with parentA (B + accessory) cells but did not suppress responses by the same (A X B)F1 Th cell population cooperating with parentB (B + accessory) cells. Neither parentA-restricted Ts cells alone nor parentB-restricted Ts cells alone suppressed the responses of (A X B)F1 (B + accessory) cells, whereas a mixture of these two Ts cell populations was able to significantly suppress the responses of F1 (B + accessory) cells. In contrast, responses of (A X B)F1 leads to parentA Th cells (restricted to recognizing parentA but not parentB MHC determinants on F1 cells) and (A X B)F1 (B + accessory) cells was suppressed by parentA-restricted Ts cells but not by parentB-restricted Ts cells. Collectively these findings suggest that the Ts cell populations characterized here do not function by directly inhibiting the activity of Th cells, B cells or accessory cells of a given MHC genotype, but rather that they appear to function through a unique mechanism involving highly specific inhibition of the interaction between MHC-restricted Th cells and the (B + accessory) cells required for these responses.

Animals↗
PubMed1983

Studies of residual alkali on intraocular lenses sterilized with NaOH.

We measured the effects of pH changes after water washings of polymethylmethacrylate (PMMA) intraocular lenses sterilized in 10% sodium hydroxide (NaOH). Whereas inserting the base-sterilized lens directly into the eye causes a large pH change in the local area of the implant, three separate washings of the NaOH-treated implant in 15 ml of water eliminates this change. No buffer is required.

Humans↗
PubMed1983

Immunogenicity of wild and attenuated varicella-zoster virus strains in pygmy marmosets.

Pygmy marmosets were inoculated with the low-passage parental strain or with the attenuated variant of OKA strain of varicella-zoster virus. No clinical signs were observed following inoculation and virus could not be isolated from tissues taken at several times after inoculation. A low-level antibody response developed in all animals. Three months after the first inoculation, all animals were challenged with the low-passage parental strain of virus. Animals primed originally with the parental strain developed higher booster responses than animals primed with the attenuated strain of virus. The results suggest that the parental and attenuated strains of varicella-zoster virus differ in their immunogenicity in pygmy marmosets.

Animals↗
PubMed1983

T cell regulation of B cell activation: antigen-specific and antigen-nonspecific suppressor pathways are mediated by distinct T cell subpopulations.

The present studies were carried out to characterize the cellular events involved in the induction and function of carrier-specific Ts cells, which selectively regulate the generation of IgG responses by Lyb-5- B cells. It was demonstrated that this regulation is in fact mediated by two distinct suppressor pathways. In one pathway, carrier-primed Lyt-1 + 2 - Ts cells are specifically activated by in vitro reexposure to the priming antigen. After this specific activation, these Lyt-1 + 2 - Ts cells are able to suppress IgG responses in an antigen-nonspecific manner. This suppression requires the participation of unprimed Lyt-1 - 2 + T cells, and is effective in both the early and the late phases of antibody responses. A second suppressor pathway requires the antigen-specific activation of primed Lyt-1 - 2 + Ts cells. Suppression of antibody responses by activated Lyt-1 - 2 + Ts cells is highly carrier specific, in contrast to the nonspecific effector function of Lyt-1 + 2 - Ts cells, appears to act without requirement for additional T cell populations; and is effective only early in the course of the antibody response. Thus, it appears that two Ts cell populations may function through distinct mechanisms to regulate the generation of IgG Lyb-5- B cell responses.

Animals↗
PubMed1983

Five-year follow-up study of recipients of live varicella vaccine using enhanced neutralization and fluorescent antibody membrane antigen assays.

Twenty-six healthy children susceptible to varicella were inoculated with the OKA strain of live attenuated varicella vaccine. All of the recipients showed good antibody responses without adverse clinical reactions. The seropositivity rate 5 years after vaccination was 100% by the enhanced neutralization test and 96% by the fluorescent antibody membrane antigen (FAMA) test. None of the recipients contracted varicella in spite of documented contact exposure. None of the children developed herpes zoster during the 5-year observation period. The results suggest that attenuated varicella vaccine has long-term protective efficacy.

Antibodies, Viral↗
PubMed1983

Role of the major histocompatibility complex in T cell activation of B cell subpopulations. Ir gene regulation of the T cell-dependent activation of distinct B cell subpopulations.

Antibody responses to (T,G)-A--L and (H,G)-A--L or to the TNP conjugates of these polypeptides, are regulated in the mouse by Ir genes encoded in the I-A subregion of the mouse MHC. To study the mechanism by which Ir genes function, it is essential to identify the cell interactions that are regulated by these genes. In the present report, it was specifically determined whether Ir gene function is expressed differently in the activation of B cell subpopulations that participate in two different pathways of B cell activation for in vitro antibody responses to TNP-(T,G)-A--L and TNP- (H,G)-A--L. The results of these studies demonstrate that under conditions that activate the Lyb-5- b cell subpopulation via MHC-restricted TH cell-B cell and TH cell-APC interactions, Ir gene function regulates TH cell interactions with these B cells as well as with APC. In addition, under conditions that activate the Lyb-5+ B cell subpopulation via MHC-restricted TH cell-APC but not TH cell-B cell interaction, Ir gene function regulates only TH cell interactions with APC but not with B cells.

Animals↗