The Japanese journal of experimental medicine最新文献

Vesical foreign bodies readily lead to urolith formation but not in Brattleboro rats with diabetes insipidus. This experiment was designed to examine the roles of vesical foreign bodies, urine osmolality, and vesical infection in the formation of uroliths and associated reactive urothelial hyperplasia. ADH-deficient Brattleboro rats received surgical insertion of a silk suture in the bladder. Their bladders were infected with intravesical injection of urease positive P. vulgaris, while controls were similarly injected with sterile Ringer's sol. They received daily injections of either pitressin tannate in oil (1 U/kg body weight) or peanut oil. Urine flow rate, urine osmolality, urine culture, and gross and light microscopic examinations of the bladders were carried out at the end of 4th week. The results indicated that uroliths readily formed in the presence of all three factors; vesical foreign bodies, high urine osmolality, and infection, but not as readily in the presence of two or less of these three factors. The urothelial hyperplasia was prominent in infected bladders followed by non-infected bladder with high osmolar and low osmolar urine in this order.

Clostridium tetani was isolated from human and animal stools at the following rates [95% confidence interval (CI)]: Human, 0% (1.5-0); horse, 1% (5-0); cow in cowshed, 4% (10-1); cow in pasture, 8.3% (17-1), calf in pasture, 0% (7-0); dog, 2% (11-0) and sheep in pasture, 25% (44-14). Quantification of C. tetani in 16 animal stools positive for the bacillus was impossible in most cases, as the number of tetanus bacilli present was not large enough for this purpose. Contaminating anaerobic and facultative anaerobic bacteria in human and animal stools, i.e., C. perfringens and Streptococcus sp., Group G, inhibited isolation of C. tetani from these materials, particularly at the step of isolation employing its swarming character.

The antifilarial activity of combination of diethylcarbamazine (DEC) and an immunomodulator, N-Palmitoylmuramyl-L-alanyl-D-isoglutamine (NP-MDP) was evaluated against Litomosoides carinii in cotton rat (Sigmodon hispidus) and Mastomys natalensis. DEC was used at 6 mg/kg in cotton rat whereas it was 75 mg/kg x 5 days in mastomys. The immunomodulator was administered at 62.5 to 500 micrograms/animal x 2 days. Combination therapy with optimum dose of immunomodulator resulted in prolonged and significant suppression of microfilaraemia in comparison to infected animals treated only with DEC. The effective doses of immunomodulator alone or in combination with DEC also caused enhanced antibody titre in treated animals. Though combination therapy resulted in prolonged suppression of microfilaraemia, the effect disappeared slowly and caused no damage to adult worms.

Simplified-in vitro system was developed to examine the contribution of host's cells in graft-versus-host (GVH)-disease-associated immunodeficiencies. In analogy with major histocompatibility complex (MHC)-matched GVH-reaction, (BALB/c x DBA/2)F1 (H-2d) hybrid spleen cells were co-cultured with irradiated BALB/c (H-2d) spleen cells, so that cellular activities to be generated are ascribable to F1 cells. In vitro development of anti-allo-specific cytotoxic T cells of the F1 origin was dramatically suppressed by coexistence of the irradiated parental cells and by the addition of F1 cells precultured once with the parental cells, suggesting the generation of suppressor cells in the F1 (host) cells activated by the parental cells. Thus generated suppressor cells are Thy.1-, weakly or nonadherent and radiosensitive. Interestingly, in the same reactions there also developed Thy.1- cytotoxic cells for autologous macrophage targets. An involvement in immunodeficiencies in GVH disease of the host-derived cytotoxic and/or immunosuppressive, non-T cells was discussed.

When injected into the sole of the hind paw of mice, Habu snake (Trimeresurus flavoviridis) venom produced a prolonged oedema (72 hours). When administered alone, most of the studied drugs (mepyramine, methysergide, cyproheptadine, indomethacin, aspirin, dexamethasone and aprotinin) inhibited this oedema only partially and transiently (less than 7 hours). Some drugs however (EDTA, Biogel P4, zymosan and celluloses) were able to abolish it progressively. Combinations of some of these drugs resulted in various synergisms; in particular important and prolonged inhibitions were observed with aprotinin-dexamethasone, one of these drugs and EDTA, and especially EDTA-zymosan, which abolished totally the oedema from 2 hours after the injection of the venom to its end (72 hours). Antagonisms between components of combinations were also observed. The mechanisms of these synergisms and antagonisms are discussed. In particular, it is suggested that the blockade of the two pathways "classical" and "alternative", of the complement by EDTA and zymosan respectively might account for their important and early synergism. Antagonisms also helped in indicating some mechanisms of action.

Glomerulosclerosis and vascular lesions occurring in rats receiving 11-deoxycorticosterone and salt-loading have been studied in order to examine their relationship. The glomerular lesion started as focal segmental sclerosis. The globally sclerosed glomeruli were enlarged in size, demonstrating that these showed no evidence of ischemic atrophy. Advanced glomerulosclerosis occurred independent of preglomerular arteriolar pathologic lesion. No meaningful structural changes were observed in the arterial system. In conclusion, DOC-salt-induced glomerulosclerosis started as segmental lesion, occurred independent of structural alterations in the preglomerular arterioles, and took place without evidence of intrarenal arterial stenosis. Further studies are necessary to clarify about the role of hemodynamic stress-related injury to glomerular microcirculatory system as a major cause for DOC-Salt-induced glomerulosclerosis.

To investigate the protective mechanism against the lethal effect of whole body vibration, the phentolamine (1 mg/kg) pretreated rats were exposed to whole body vibration with a frequency of 20 Hz under an acceleration of 5 G at 24 +/- 2 degrees C and 5 +/- 1 degrees C. Five of 9 rats pretreated with phentolamine died from the exposure to whole body vibration within one hour at 24 +/- 2 degrees C. In these rats, marked infrapleural hemorrhage, dilatation of alveolar capillary vessels, and intraalveolar hemorrhage and edema were observed. However, all of the 10 rats pretreated with saline survived through the one hour exposure to the same vibration, and showed only slight histological changes in the lung. On the other hand, no rats pretreated with saline or phentolamine died from the exposure to whole body vibration within one hour at 5 +/- 1 degrees C. These results suggest that the alpha-adrenergic system and cold have a role of protection against the lethal effects of whole body vibration.

3H-labeled endotoxin was intravenously injected into Wistar rats 24 hours following 70% hepatectomy and also into the normal rats. They were sacrificed 12 hours, 24 hours or 5 days after the injection. Microscopical autoradiography was performed on the rats' organs. The distribution of endotoxin in the organs was investigated by quantitatively measuring their radioactivity. Endotoxin was taken up mainly by Kupffer cells of the liver in all the groups. Endotoxin was observed also in macrophages of the spleen and the lung in all the groups. The amount of endotoxin per 1 g organ weight of the hepatectomized rat was significantly smaller in the liver, and significantly larger in the spleen, lung and blood (per 1 ml) than that of the control groups early after hepatectomy. These differences of the organ accumulation of endotoxin between groups diminished 5 days later. Deficient tolerance of the liver to endotoxin at the peak phase of regeneration following partial hepatectomy was suggested.

Techniques of a micro enzyme-linked immunosorbent assay (ELISA) used for the serodiagnosis of schistosomiasis were applied to amebic infection. Test sera were divided primary on the basis of serologic diagnosis and stool examination as follows; (I) gel diffusion precipitin test (GDP) positive and stool examination positive: 9 specimens, (II) GDP positive and stool examination negative: 29 specimens, (III) GDP negative and stool examination positive: 32 specimens. Virtually all of the individuals belonging to (III) were asymptomatic, while more than 75% of (I) and (II) were symptomatic. The upper limit of 99% critical range was calculated from the data of 70 serum specimens from healthy adult Japanese and was employed as the cut-off value. All of the specimens of (I) and (II) were judged positive by ELISA, generally with a much higher absorbance than the cut-off value; whereas, approximately 80% of (III) were judged positive. The average absorbance of (III) was lower than that of (I) and (II). These findings suggest that the ELISA is well in accord with GDP qualitatively as far as GDP-positive individuals are concerned, and that even asymptomatic cyst carriers with negative serology by GDP may often be producing anti-amebic antibodies, although the titers are low.