Summary
The effect of mouse testicular extract (TE) on lymphocyte activation was investigated. TE, in the dose range 75–600 μg mi‐1, suppressed significantly the blastogenic response of splenocytes ...to concanavalin A (Con‐A), pokeweed mitogen (PWM), phytohaemagglutinin (PHA) and lipopolysaccharide (LPS). TE also suppressed the blastogenic response of B‐cells to LPS and of T‐cells to PHA in a dose‐dependent manner as well as suppressing the mixed lymphocyte reaction (MLR). Pretreatment of splenocytes with TE did not however, completely suppress their blastogenic response to Con‐A, when the treated cells were washed prior to culturing. Furthermore, TE did not inhibit the on‐going blastogenesis of splenocytes that had been activated already with Con‐A for 48 h. Splenocytes obtained from TE‐treated mice remained capable of responding to Con‐A stimulation, whereas they did not respond to listerial antigens when mice were immunized with Listeria monocytogenes together with TE. The effects of TE were enhanced significantly by heating to 100°C, but were resistant to pronase, RNase and DNase. These results suggest that TE affects non‐specifically the stage of lymphocyte sensitization to antigens or mitogens.
Summary
The effects of the water‐insoluble fraction of mouse seminal vesicle fluid (WIF‐SVF) on lymphocytes was investigated to clarify its role in reproductive immunity. WIF‐SVF inhibited the ...blastogenic response of T‐cells to concanavalin‐A (Con‐A), but it did not inhibit the blastogenic response of B‐cells to lipopolysaccharide (LPS). Pretreatment of splenocytes with WIF‐SVF did not suppress the blastogenic response of splenocytes to Con‐A when treated cells were washed prior to culture. WIF‐SVF did not inhibit the proliferation of Con‐A activated splenocytes, the response of listeria‐immune splenocytes to listerial antigen, or the proliferation of IL 2‐dependent HT‐2 cells, or the growth of tumour cells (Yac 1 cells, Ehrlich ascites carcinoma cells, EL‐4 cells). A listerial antigen‐specific immune response was not induced after mice were immunized with both listerial antigen and WIF‐SVF. WIF‐SVF is mainly composed of protein and its suppressive activity was enhanced by heating at 100°C. These results suggest that WIF‐SVF inhibits the responsiveness of T‐cells to antigens or mitogens non‐specifically at the initial stage.
Background The purpose of this study was to determine the effect of systemic blood pressure–lowering treatment with an angiotensin II receptor blocker, valsartan, on cerebral hemodynamics in patients ...with hypertension and evidence of cerebral small vessel disease. Methods We used positron emission tomography and acetazolamide challenge tests to measure cerebral blood flow (CBF) and cerebrovascular reserve (CVR) in 8 patients with hypertension (mean age 70.8 years) with lacunar infarcts and white matter lesions before and after valsartan therapy. Results Systemic blood pressure was significantly decreased from baseline after treatment with valsartan. The baseline global CBFs before and after treatment were 38.2 ± 5.6 mL/min/100 g and 39.9 ± 9.0 mL/min/100 g, respectively. The CVRs before and after treatment were 52.2 ± 18.4% and 39.7 ± 18.9%, respectively. Differences in these parameters were not significant. Both regional CBF and CVR in the corona radiata with moderate or severe white matter lesions were also preserved after valsartan therapy compared with those before treatment. Conclusions Cerebral hemodynamics were preserved after blood pressure lowering with valsartan therapy. Valsartan could be a feasible antihypertensive regimen in terms of cerebral circulation in patients with cerebral small vessel disease.
Live-cell vaccines of Salmonella typhimurium, either a sub-lethal dose of a wild-type (strain LT2) or a high dose of its two-heptose Rd1 mutant (strain SL1004), induced acquired resistance to murine ...typhoid, which remained 180 days after immunization. Growth of S. typhimurium as a bacillary form ceased between days 30 and 60 of immunization, but L forms of this bacterium colonized the liver (the mean number of L forms in the liver: 600 L-forming units) even at 180 days post-immunization. In contrast, a high inoculum of either a Ra mutant (strain TV148) of strain LT2 or S. schottmülleri 8006 sharing the same O antigenic components with those of S. typhimurium induced only a short-lived protection in proportion to the number of L forms in the liver, and the protective immunity was lost before day 180. However, there was no significant difference in the salmonella-specific T-cell responses among groups of immunized mice on day 180 of immunization. A lethal infection with strain LT2 in mice which had been immunized 75 days previously with living cells of strain SL1004 resulted in a rapid clearance of the challenge inoculum, together with a rapid elevation of anti-S. typhimurium antibody responses. Thus, the present data suggest that the long-lived immunity conferred upon live S. typhimurium vaccines is attributable to the colonization of this bacterium in the liver as L forms and the ability to colonize the liver as L forms is independent of the chain length of salmonella O-antigens.
The isolation and determination of biological activities of the active component of Corynebacterium kutscheri were attempted in the present investigation. The antitumor effect was confined to the ...subcellular particle fraction of this bacterium and was associated with a molecule of glycoprotein nature (40,000-38,000 Daltons) isolated from this fraction by affinity chromatography with concanavalin A-Sepharose 4B. This substance exerted mitogenic activity on C3H/HeJ splenocytes and T cells, stimulatory activity on macrophages, and further exhibited antitumor effect on P388 leukemia in CDF1 mice. The Winn assay disclosed that the antitumor effect induced by this substance was dependent on L3T4+ T cells. Furthermore, both the mitogenic and antitumor activity of this moiety were resistant to heating at 100 degrees C for 30 min or RNase digestion, but sensitive to trypsin digestion, or low or high pH. These results indicate that the antitumor effect of C. kutscheri is attributable to the heat-stable glycoprotein moiety which can directly stimulate T cells and macrophages.
The effect of local injection of formalin-killed Corynebacterium kutscheri (FK.CK) on mouse survival after the intraperitoneal inoculation of Ehrlich ascites carcinoma in outbred ddY mice or P388 ...leukemia cells in inbred CDF1 mice was investigated. Treatment of mice in the dose range of greater than 10(6) organisms per mouse conferred the substantial protection on both mice. The initial phase of antitumor effect consisted of the marked increase in the number of peritoneal exudate cells and the enhanced cytotoxicity of peritoneal exudate cells. The Winn assay disclosed that antitumor effect by which tumor-burden mice could survive was attributable to nonadherent splenocytes whose activity was impaired by treatment with anti-T cell serum and complement. A single injection of FK.CK induced the cytotoxicity to three different murine tumor cells in serum of treated mice without a boosting injection of endotoxin. Furthermore, the generation of effector cells and serum cytotoxicity seemed to be paralleled by that of the delayed-type hypersensitivity to this organism. Thus, the antitumor resistance induced by C. kutscheri is considered to be in part T cell mediated.
We search for ultra-high energy photons by analyzing geometrical properties of shower fronts of events registered by the Telescope Array surface detector. By making use of an event-by-event ...statistical method, we derive upper limits on the absolute flux of primary photons with energies above 10^19, 10^19.5 and 10^20 eV based on the first three years of data taken.
We search for correlations between positions of extragalactic objects and arrival directions of Ultra-High Energy Cosmic Rays (UHECRs) with primary energy \(E \ge 40\) EeV as observed by the surface ...detector array of the Telescope Array (TA) experiment during the first 40 months of operation. We examined several public astronomical object catalogs, including the Veron-Cetty and Veron catalog of active galactic nuclei. We counted the number of TA events correlated with objects in each catalog as a function of three parameters: the maximum angular separation between a TA event and an object, the minimum energy of the events, and the maximum redshift of the objects. We determine combinations of these parameters which maximize the correlations, and calculate the chance probabilities of having the same levels of correlations from an isotropic distribution of UHECR arrival directions. No statistically significant correlations are found when penalties for scanning over the above parameters and for searching in several catalogs are taken into account.
We measure the spectrum of cosmic rays with energies greater than \(10^{18.2}\) eV with the Fluorescence Detectors (FDs) and the Surface Detectors (SDs) of the Telescope Array Experiment using the ...data taken in our first 2.3-year observation from May 27 2008 to September 7 2010. A hybrid air shower reconstruction technique is employed to improve accuracies in determination of arrival directions and primary energies of cosmic rays using both FD and SD data. The energy spectrum presented here is in agreement with our previously published spectra and the HiRes results.
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