Allele- and parent-of-origin-specific effects on expression of the KCNJ11 gene: A candidate for meat tenderness in cattle.

In contrast to the Mendelian inheritance model, parental alleles can contribute unequally to gene expression, which may result in phenotypic variance among individuals and bias in the predicted additive effect of molecular markers associated with production traits. Given the need to understand the effects of allelic variation and parent-of-origin effects on the expression of genes with a commercial interest in cattle, we analyzed the expression of KCNJ11 (potassium inwardly rectifying channel, subfamily J, member 11), which was previously described as a functional candidate gene for meat tenderness. Allele-specific and parent-of-origin-dependent expression of this gene were assessed in bovine muscle using the rs379610823 single nucleotide polymorphism as a reference. Biallelic expression was observed; however, the T allele was expressed at significantly higher levels than the C allele. Furthermore, increased expression of KCNJ11 was found in animals harboring the maternal T allele. This study is the first to describe the differential allelic expression of bovine KCNJ11. Our findings are important for understanding the mechanisms that underlie the pattern of KCNJ11 expression and its potential impact on the phenotypic variation of meat tenderness in Nelore beef cattle. This reinforces the need for further investigation of allelic- and parent-of-origin expression deviation in genetic markers eligible for the selection of target traits.

Controlled field trials of a vaccine against New World cutaneous leishmaniasis.

Two controlled, double blind field trials of a non-living promastigote vaccine against New World Cutaneous Leishmaniasis (NWCL) were conducted in 1981 and 1983 in Brazil. Brazilian Army conscripts were randomly assigned to the vaccine or placebo groups and tested during their training in the Amazon jungle, a high risk area for NWCL. The results obtained showed: no significant differences between the vaccine and the placebo groups with respect to a number of characteristics (age, race, previous contact with the jungle, etc.); no significant differences between the participants who got and who did not get NWCL during the trial, with respect to length of exposure, contact with the jungle, etc. and a reduction of 67.3 and 85.7% in the annual incidence rate of NWCL, in 1981 and 1983 respectively (although the difference between incidence rates of the disease in vaccinated and control groups in the 1983 trial was not statistically significant), among those vaccinated who had converted to a positive leishmanin skin test as compared with the placebo groups.

Effect of the injection of ribosomes and RNA from Crithidia fasciculata on the experimental infection of mice by Trypanosoma cruzi.

Immunization of mice with Crithidia fasciculata (live suspension, ribosomal fraction and purified RNA) induced a certain degree of protection (decrease of parasitaemia) against infection with Trypanosoma cruzi.

A field trial of a vaccine against American dermal leishmaniasis.

A field trial was carried out in the eastern part of the State of Minas Gerais (Brazil) of a vaccine containing killed promastigotes of five stocks of Leishmania. Tests with Montenegro antigen showed that a high proportion of the vaccinated persons became positive within three months, but circulating antibodies were not detected. A proportion of those vaccinated continued to give positive Montenegro reactions for up to three years. Lymphocyte sensitivity tests carried out, on a small sample, three years after vaccination were positive and gave no evidence of immunological depression. No cases of cutaneous or mucocutaneous leishmaniasis occurred in the trial area during the three years of observations.

Some characteristics of the hyperreactivity to bacterial lipopolysaccharide induced in mice by Trypanosoma cruzi infection.

Mice infected with T. cruzi, Y strain, acquire a high level of susceptibility to the effects of bacterial gram-negative LPS. The LD50 of adult female SW mice to LPS from S. typhosa, decreases from 450 to 2,5 mcg 10-12 days after T. cruzi infection. This hyperreactivity to LPS induced by T. cruzi presents all the characteristics of that found in infection caused by many other agents. During the acute phase of experimental infection with T. cruzi Y strain, mice generally die with a hypovolemic shock very similar to that induced in uninfected animals injected with an adequate dose of bacterial endotoxin. There is evidence for and against the hypothesis that LPS absorbed from the intestinal tract may be involved in the mechanism of death of mice during the acute phase of T. cruzi infection.

Comparison of penalties resulting from first-order and all-order polarization mode dispersion distortions in optical fiber transmission systems.

We compare the eye-opening penalty from a first-order polarization mode dispersion (PMD) model with that from an all-order PMD model in optical fiber transmission systems. Evaluating the performance by taking into account only first-order PMD produces a good approximation of the true eye-opening penalty of uncompensated systems when the penalty is low. However, when the penalties are high, this model overestimates the penalty for outage probabilities in the range of interest for systems designers, which is typically approximately 10(-5) to 10(-6).

Effect of insulin on immunological phagocytosis by macrophages.

It was shown that, in physiological concentrations, insulin enhances, in vitro, the immunological phagocytosis of sensitized sheep erythrocytes by cultured mouse peritoneal macrophages. Insulin seems to stimulate macrophage phagocytosis as a cholinomimetic agonist by increasing the intracellular levels of cyclic GMP.

Immunologic phagocytosis by macrophages: effect by stimulation of alpha adrenergic receptors.

Alpha adrenergic stimulating drugs, metaraminol, norepinephrine, phenylephrine, was found to increase, in vitro, immunological phagocytosis by mice peritoneal macrophages. This effect could be inhibited by dibenamine, a blocking agent. The stimulation by alpha adrenergic agents was similar to that caused by drugs that reduce the intracellular levels of cyclic adenosine monophosphate or by drugs that increase the levels of cyclic guanosine monophosphate.

[Protection of mice by trehalose dimycolate against lethal infection by Trypanosoma cruzi]. / Protection de souris par le dimycolate de tréhalose (tdm) contre une infection létale par Trypanosoma cruzi.

Four weekly injections of 50 micrograms of trehalose dimycolate (TDM) in FIA protect 40% of the Mice against a lethal infection by Trypanosoma cruzi; under the same conditions MDP (muramyldipeptide) has only a very slight effect.

Rosette formation by human T and B lymphocytes in the presence of adrenergic and cholinergic drugs.

It was shown that adrenergic drugs, which increase the intracellular levels of cAMP, inhibit the rosette formation by T-lymphocytes, but stimulate the rosettes produced by B-lymphocytes. Cholinergic drugs, which increase the levels of cGMP, on the contrary, stimulate the formation of rosettes by T-lymphocytes but inhibit those produced by B-lymphocytes.

[Leukocyte migration inhibition with soluble and particulate antigens (author's transl]. / Inibição da migração dos leucócitos com antígenos particulados.

Studies were carried out with the leukocyte migration inhibition tests using soluble and particulate antigens (PPD, somatic antigens of T. cruzi, M. bovis (BCG) and leukocytes from patients sensitized to PPD and patients with chronic Chagas' disease. The results obtained showed that the stimulatory capacity of particulate antigens are greater than that of soluble antigens.

[Humoral and cellular immunity in children vaccinated with oral B.C.G. (author's transl)]. / Imunidade humoral e cellular em crianças vacinadas com B.C.G. pela via oral.

The humoral and cellular immunity of 23 children with ages between 1 and 5 years, nonreactors to 10 mu of PPD, were investigated after oral vaccination with one dose of 100 mg of fresh oral BCG, Rio de Janeiro strain (Moreau strain). The tests performed shortly before and 70 days after vaccination showed that the schedule used was neither sufficient to stimulate the production of antibody anti-PPD, nor to change the levels of serum immunoglobulins and T, T-active and B blood lymphocytes. However, about 60% of the children became responsive to 10 mu of PPD after treatment and all gave positive reactions to PPD on "in vitro" assays of leukocyte migration inhibition. New schedules for oral vaccination with fresh BCG are in progress in our laboratory.

Immunization of mice with Trypanosoma cruzi polyribosomes.

Studies were carried out with a polyribosomal fraction isolated from Trypanosoma cruzi Y epimastigotes, with the intention to determine both its immunogenic activity and the degree of protection it could induce against experimental T. cruzi infection. This fraction was assayed in four groups of mice by using different schedules of vaccination and varying the dose, intervals, and route of administration. Seven days after the last dose, the animals were sacrificed for immunological studies or subjected to challenge with T. cruzi trypomastigotes. The results obtained in all schedules showed that our polyribosomal fraction only induced a weak antibody response, but was capable of evoking an expressive cellular response. It was also shown that this fraction has the capacity of inducing a high degree of protection against T. cruzi infection, as determined by the decrease of parasitemia and the prolonged survival time of immunized animals.