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At least 739 records · Page 41Linked to original sources
PubMed1992

Augmentation of host's naturally acquired immunity by solubilized membrane-bound midgut proteins of the tick Rhipicephalus appendiculatus.

Immune resistance of rabbits to the hard tick Rhipicephalus appendiculatus induced by combined tick infestations and immunization with solubilized midgut membrane proteins were compared with resistance due to 1-3 infestations or immunization alone. Results demonstrate that the level of exposure of rabbits to ticks used in the study does not significantly affect the immune expression resulting from immunization and that the latter augments the resistance due to infestation.

Analysis of Variance↗
PubMed1992

Kinetics and fate of IgA-IgG aggregates as a model of naturally occurring immune complexes in IgA nephropathy.

The characteristic granular IgA immunofluorescent pattern in the kidneys of IgA nephropathy patients is consistent with immune complex pathogenesis. The possibility of a delayed clearance of IgA-containing immune complexes from circulation in IgA nephropathy patients is still under discussion. Since pure IgA immune complexes are probably nonphlogistic, (in contrast to IgG-containing IgA immune complexes), the in vivo clearance of a mixture of heat-aggregated IgA/G purified from pooled human sera was analyzed. The test probe was efficiently labeled with 123I and the time course of radioactivity was measured by a gamma-camera. Both the liver and the spleen were found to be involved in the disappearance of IgA/G complexes. Liver accumulation, which was markedly predominant, closely approximates a gamma-variate function which allowed determination of a mean transit time of 34.37 minutes, range 29.8 to 42.2, in 8 normal and 37.54 minutes, range 30.9 to 50.7 in 17 patients (p less than 0.04). At 2 hours, segmental gut accumulation was found, which demonstrated removal by hepatobiliary system as well. Compartmental analysis in patients indicated 3 major compartments represented by vascular bed, hepatobiliary and reticuloendothelial systems (including both liver and spleen phagocytes). Blood clearance rate, representing the final result of multiorgan removal of the test probe from the blood stream, was found to be significantly delayed in IgA nephropathy patients with a slope (0.035 min-1, range 0.019 to 0.052) significantly less negative compared with controls (0.047 min-1, range 0.038 to 0.053, p less than 0.01). This test probe was able to reproduce both removal routes (macrophages cells and hepatobiliary system) hypothesized for IgA-containing immune complexes in humans.

Adult↗
PubMedDate not supplied

[Rubella infection in pregnancy in naturally acquired immunity].

This case-report concerns the problem of rubella-reinfection in pregnancy (17th week of gestation). Inspite of documented maternal immunity infection was followed by transmission of virus to the fetus. Nowadays in most countries antenatal maternal screening for rubella seems to be sufficient. The observation of cutaneous exanthema, however, demands further investigation, even if maternal immunity was documented.

Adult↗
PubMedDate not supplied

Serum SRH antibody level as a measure of the immunity against natural and artificial A/Victoria/3/75 infections.

A natural influenza A/Victoria/3/75 outbreak occurred in two communities where part of the residents had been vaccinated with a live recombinant vaccine strain, the RIT 4025 strain (A/Scotland/840/74 serotype). Using the single radial hemolysis technique to measure the antibody level, a relationship was established between the rate of infection and the pre-epidemic serum antibody titer. The higher the pre-epidemic antibody titer, the lower the rate of infection and illness. The protective titer 50% (PT 50) against infection was equal to 26.7 mm2. The same calculation was applied to a population of placebo recipients and RIT 4025 vaccinees challenged with a virulent A/Victoria/3/75 strain. Although the number of volunteers was much smaller, the same correlation was found for the infection detected by a significant antibody rise and for confirmed illness.

Antibodies, Viral↗
PubMedDate not supplied

Natural tetanus immunity in lepromatous leprosy patients.

35 lepromatous leprosy patients with recurrent trophic ulcers were analysed for tetanus antitoxin levels by passive haemagglutination test (PHA). 42.85% patients and 32% controls had protective levels of antitoxin in their serum (greater than or equal to 0.1). All the patients (100%) demonstrated measurable antitoxin levels. The findings indicate immunological protection from tetanus and support the clinical impression of it's rarity in leprosy patients.

Adult↗
PubMed1986

Induction of tumor immunity and natural killer cell cytotoxicity in mice by 5-halo-6-phenyl pyrimidinone.

We have investigated the effect of pyrimidinone molecule 2-amino-5-iodo-6-phenyl-4 pyrimidinone (AIPP) on natural killer (NK) cell lytic potential and on the growth of ascitic mammary adenocarcinoma, ACA-755, in B6D2F1 mice. Our studies demonstrated that AIPP was effective in both the prophylaxis and the therapy of this tumor and that the antitumor effect was mediated via induction of NK cell lytic activity. In vitro characterization studies showed that the AIPP-induced cytotoxic cells were not macrophages and exhibited characteristics of NK cells such as morphology of the large granular lymphocytes and sensitivity to asialo GM-1 antibody. Analysis of the mechanism of potentiation of NK cell cytotoxic function by AIPP indicated that the enhancement of cytotoxicity was accomplished by recruitment of NK cell tumor-binding potential (primarily those with large granular lymphocytic morphology) as well as by increased frequency of lytic NK cells. These studies implicate NK cells in the defense against malignant tumors and suggest that regional therapy with AIPP may represent a new therapeutic modality for treatment of cancer.

Animals↗