A generalised additive model to characterise dairy cows' responses to heat stress.

Heat stress is one of the most critical issues jeopardising animal welfare and productivity during the warm season in dairy cattle farms. The global trend of increase in average and peak temperatures is making the problem more and more serious. Many devices have been introduced in livestock farms to monitor and control temperature-humidity index, as well as animal behaviour and production parameters. The consequent availability of collected databases has increasingly enhanced the research aimed to understand the consequences of heat stress in cattle, in relation to genetic, reproductive, productive and behavioural features. Moreover, these investigations laid the foundations for the development, calibration, validation and test of numerical models quantifying the individual responses to heat stress conditions. In this work, a generalised additive model with mixed effects has been developed to analyse the relationship between milk production, animal behaviour and environmental parameters based on data surveyed in 2016 in an Italian dairy farm. Each cow has been characterised in terms of her response to heat conditions, and the results led to define three classes of susceptibility to heat stress within the herd. These attributes have then been related to the various phenotypic parameters collected by the precision livestock farming devices used in the farm. The study provides a model to understand the effects of heat stress conditions on individual animals in relation to the main parameters describing their rearing conditions; moreover, the results contribute to improve the herd management by lending indications to define targeted treatments according to the cow's characteristics.

Distribution of killer cell immunoglobulin-like receptor genes in the mestizo population from Venezuela.

This study represents the first report on the distribution of KIR genes in 205 unrelated healthy mestizo Venezuelan individuals. Genotyping analysis showed that all KIR genes are present in this population. Frequency of inhibitory killer cell immunoglobulin-like receptors (KIRs) exceeded 0.69, except for KIR2DL2 (0.29) and 2DL5 (0.37). Activating KIRs showed low frequencies (0.11-0.29), except for KIR2DS4 (0.68). Forty-five different KIR genotypes were identified, with a predominance of three genotypes found in 50.7% of the population of which 25.9% were individuals homozygous for haplotype A. The frequencies of KIR genes reflect the ethnic admixture existing in the mestizo Venezuelan population.

Lymphocyte subset diversity in idiopathic CD4+ T lymphocytopenia.

The clinical and public health importance of CD4+ T lymphocytopenia without human immunodeficiency virus infection is still unclear. We describe herein two new human immunodeficiency virus-negative patients with low numbers of peripheral CD4+ T cells and opportunistic infections (cerebral toxoplasmosis and tuberculosis plus extrapulmonary histoplasmosis). The low numbers of CD4+ CD29+ memory cells, the high percentage of gamma delta T-cell receptor cells, and the recovery of CD4+ cells after treatment were remarkable.

Decreased T-cell proliferative response to common environmental antigens could be an indicator of early human immunodeficiency virus-mediated lymphocyte lesions.

To evaluate CD4+/CD29+ cells and their responses to different antigens in polar stages of human immunodeficiency virus (HIV) infection, we studied 26 HIV-seropositive carriers (SPCs) and 15 patients with AIDS simultaneously with 20 healthy volunteers (HVs) and 10 seronegative homosexual and bisexual men (SNH). CD3, CD4, CD29, and CD45RA phenotypes were analyzed by two-color flow cytometry. Significant depletion of CD4+ T cells and both memory (CD4+/CD29+) and naive (CD4+/CD45RA+) T-cell subsets was found among SPCs and AIDS patients compared with the numbers of such cells in the HV and SNH groups. Responses to optimal doses of Candida albicans, streptokinase, and tetanus toxoid were explored in peripheral blood mononuclear cells and CD4(+)- and CD4+/CD29(+)-enriched cell populations. In SPCs, the response to C. albicans in peripheral blood mononuclear cells showed a statistically significant diminution compared with the response of HVs (15,308 versus 35,951 cpm). In addition, a significantly reduced response to streptokinase was evident only when cell preparations were CD4+/CD29+ enriched (3,048 versus 10,367 cpm). Furthermore, the SPC group comprised seven responders to at least one antigen and seven nonresponders to any of the selected specific antigens. Absence of a response in these latter patients was independent of the absolute counts of memory and naive T-cell populations. The response to tetanus toxoid, although diminished in SPCs, was not significantly different from that in controls. Our results suggest that defective responses to common environmental antigens, unrelated to the absolute number of CD4+/CD29+ cells, is probably an early indicator of an HIV-induced lymphocyte lesion.

A double-blind, cross-over study using salbutamol, beclomethasone, and a combination of both in bronchial asthma.

A double-blind, cross-over protocol was applied to 22 asthmatic patients who were previously subjected to provocation tests with methacholine. The baseline FEV1 for mild asthma was 89.6 +/- 13.6% while for moderate asthma it was 73 +/- 6%. The initial provocation tests with methacholine revealed that the mild asthma group needed a greater accumulated dose of methacholine than that required by the moderate asthma group to lower the FEV1 by 20%, stressing the enhanced bronchial hyperreactivity present in the latter group. Significant differences in the PD20 values were obtained in both groups of patients using the combination of salbutamol plus beclomethasone. Salbutamol alone was ineffective to change the PD20 values in mild asthma while beclomethasone alone was able to change significantly the PD20 values in these patients, stressing the importance of the inflammatory component in the pathogenesis of stable asthma. Furthermore, the combination of both drugs was also more effective in the moderate asthma group than either medication alone, confirming the pharmacological control of the obstructive and inflammatory changes that are already established in patients with moderate asthma.

[Immunoclinical, molecular and immunopathologic approach to chronic viral hepatitis. Therapeutic considerations]. / Abordaje inmunoclinico, molecular e inmunopatológico de la hepatitis crónica viral. Consideraciones terapeuticas.

Through a pilot study which includes a clinical, molecular and immunopathological approach to the chronic Hepatitis induced by HBV or by HCV, we determined that 66% of HBsAg carriers are in the "non viremic" phase. The positive HBeAg "viremic" carriers showed HBV-DNA quantitation which varies between > 50 pg to > 100 pg. Both types of carries are infected with the "wild" type HBV. Each subgroup of positive surface antigemia carriers demonstrated a differential immunopathological response. So far, 96% of the HCV carriers investigated, showed HCV-RNA associated to repeatedly positive anti-HCV antibodies. Those patients with increased ALT values uniformly expressed liver histopathological signs of inflammation caused by HCV; demonstrating also the presence of peripheral blood mononuclear cells infected with HCV. At the present, the genotypes investigation indicates a predominance of HCV genotype II (1b). Autoimmune phenomenons associated to HCV have been detected only in 3 patients. The therapeutic approach with interferon alpha applied to the HCV infection preliminary showed similar results to those reported worldwide. Currently, a comprehensive approach to the chronic HBV and chronic HCV infections requires the application of Immunochemistry, Molecular Biology and Cellular Immunology combined technologies.

Levels of total haemolytic complement activity in paired dairy cow-newborn calf sera.

Total haemolytic complement (CH50) activities of sera obtained from newborn dairy calves and their corresponding dams were compared. The differences between the mean maternal and neonatal CH50 concentrations were significant (P less than or equal 0.001). The concentration of CH50 units/ml in sera from 16 calves was 52.0 +/- 21.4, whereas, for the cows it was 195.8 +/- 24.0. The ratio of cow: calf serum CH50 values averaged 4.24 with a range from 1.77 to 8.00. A positive rank correlation of 0.479 (P less than 0.05) was found between the CH50 titres in calves and their dams. Anticomplementary substances were not detected in calf sera. The possible relationships betweeen deficient CH50 levels in newborn calves and their susceptibility to infectious agents is discussed.