Biochemical and hormonal parameters of goats kept in a controlled environment consuming water with different levels of salinity / [Parâmetros bioquímicos e hormonais de caprinos consumindo água com diferentes níveis de salinidade mantidos em ambiente controlado]

The objective of this work was to evaluate the biochemical and hormonal variables of Moxotó and Canindé goats submitted to two temperatures - 26.0±0.6 (thermoneutral) and 32.0±1.2°C (above thermal comfort zone) - and consuming water with three levels of salinity (1.0, 6.0 and 12.0 dSm-1). Thirty-six animals (18 of each breed) were used, with an average age of 5.0±0.6months and an average weight of 20.0±2.3kg, housed in metabolic cages inside a climate chamber. The animals were distributed in a completely randomized design with a 2 × 2 × 3 factorial scheme (2 breeds, 2 temperatures and 3 levels of salinity) and three replications. The glucose and urea had a significant effect (P>0.05) according to water salinity. Glucose, cholesterol, protein, albumin, globulin, aspartate aminotransferase and hormones (T4, T3 and cortisol) varied according to temperature (P<0.05). There was a significant effect of time on hormonal variables (P<0.05). Biochemical and hormonal variables changed according to temperature and day shift, so that metabolism was reduced in the animals under thermal stress and accelerated when animals were in the thermal comfort zone.(AU)

O objetivo do trabalho foi avaliar as variáveis bioquímicas e hormonais de caprinos das raças Moxotó e Canindé, submetidos a duas temperaturas (26,0±0,6ºC e 32,0±1,2ºC), termoneutra e acima da zona de conforto térmico, respectivamente), consumindo água com três níveis de salinidade (1,0, 6,0 e 12,0dSm-1), utilizando-se 36 animais (18 de cada raça), com idade média de 5,0±0,6 meses e peso médio de 20,0±2,3kg, alojados em gaiolas metabólicas no interior de uma câmara climática. Os animais foram distribuídos em um delineamento inteiramente ao acaso, com esquema fatorial de 2 x 2 x 3 (2 raças, 2 temperaturas e 3 níveis de salinidade) e três repetições. A glicose e a ureia apresentaram efeito significativo (P<0,05) em função da salinidade da água. Glicose, colesterol, proteína, albumina, globulina, AST e hormônios (T4, T3 e cortisol) variaram conforme as temperaturas (P<0,05). Observou-se efeito significativo do horário sobre as variáveis hormonais (P<0,05). As variáveis bioquímicas e hormonais sofrem alterações em função da temperatura e do turno do dia, de modo que o metabolismo é reduzido em animais sob estresse térmico e acelerado quando os animais encontram-se na zona de conforto térmico.(AU)

A possible role for D8/PSF-A-like sequences in lactotroph versus somatotroph expression of the human prolactin gene.

The transcription factor GHF-1/Pit-1 is essential for the expression of GH and prolactin (PRL) by somatotrophs and lactotrophs respectively. However, PRL is not expressed in mature somatotrophs despite the presence of GHF-1/Pit-1. A possible mechanism is the presence of a somatotroph-specific repressor in the 5'-flanking sequences of the PRL gene. The region -3500/-1750 of the human (h) PRL gene is associated with negative regulatory activity and contains an element, designated D8, that resembles repressor PSF-A sequences which are located in the distal upstream region of placental members of the human GH family. An internal deletion of D8 sequences resulted in a significant stimulation of promoter activity in somatotroph GC (P < 0.005) and somatolactotroph-like GH3 and GH4C1 cells (P < 0.05), but not lactotroph-like 235-1 cells after gene transfer. However, D8 binding was observed by nuclease protection with lactotroph- as well as somatotroph-like cell nuclear protein. Although proteins that bind to the D8 element appear ubiquitous, this element does yield tissue-specific complexes in mobility shift assays. Further, competition studies do not suggest an interaction between GHF-1/Pit-1 and D8 proteins. The hPRL D8 element was inserted upstream of a thymidine kinase promoter and used to transfect pituitary and non-pituitary HeLa cells, to assess intrinsic repressor activity and/or promoter specificity. Although no repression was observed, a significant ninefold increase in expression was observed in HeLa cells (P < 0.001) which was at least twofold greater than observed in any of the pituitary cell lines tested. These results implicate D8 in the somatotroph-specific repression of hPRL; however, they also suggest that D8 can act as a stimulator as well as a repressor, depending on the interaction of a ubiquitous D8 factor forming promoter and cell-specific complexes with other elements/factors.

HTLV Tax gene expression in patients with lymphoproliferative disorders.

AIMS: To study the expression of the human T lymphotropic virus (HTLV) Tax gene in peripheral blood mononuclear cells. METHODS: Blood was collected from 72 patients with lymphoproliferative disorders. Serum from all patients was assayed for antibodies directed against HTLV-I structural proteins by ELISA and western blotting. RNA was purified from fresh blood cells and amplified by reverse transcription polymerase chain reaction (RT-PCR). After Southern blotting, the PCR products were hybridised with a 32P end-labelled probe specific for the Tax gene. RESULTS: All samples were seronegative. A specific band for the Tax gene was found in five samples. Each of the patients positive for Tax gene expression had a different type of lymphoproliferative disorder. CONCLUSIONS: Infection by HTLV-I cannot be assessed solely by immunological assays, particularly when only disrupted virions are used. Sensitive molecular biology assays are essential for detecting viral gene expression in fresh blood cells.

Heterophile binding of human antibodies to glycoproteins of retroviruses.

The binding of human immunoglobulin to Type C viruses has been analysed by radioimmunoassay. The assay is a double-antibody, solid-phase RIA, which has been optimized and calibrated using rabbit and human anti-MuLV sera. It detects varying concentrations of IgG binding to HL-23-V-1, a human Type C virus isolate, in all of a large number of human sera tested. As judged by inhibition with nonspecific glycoproteins, heterophile antigens and pure saccharides, this binding is to the glycoside moiety of the virus-envelope glycoproteins, in agreement with other recent reports. Nonspecific binding of this type stringently restricts the interpretation which can be placed on these and earlier data in man concerning antibodies to Type C viruses. It does not however exclude the possibility that Type C viruses do occur in man and do elicit antibody therein.

Isolation of a new serovar of the genus Leptonema in the family Leptospiraceae.

A leptospira-like spirochete was isolated from a lymphocyte culture from a HIV-I and HTLV-I/II-positive patient. On the basis of serological, biological and morphological characteristics of the cells of the isolated strain (strain Lisboa), we conclude that it is a member of the genus Leptonema.

Seroprevalence of HTLV-I in Portugal and evidence of double retrovirus infection of a healthy donor.

The prevalence of antibodies to HTLV-I in 5,475 Portuguese from 6 regions spanning the country was studied. Overall seroprevalence was 0.55%, indicating that Portugal is not an endemic area for this virus. Seropositives were distributed throughout the country, and no geographic clustering was observed. The seroprevalence of individuals who had lived in former Portuguese colonies in Africa (0.7%) was significantly higher than that of individuals who had not been in Africa (0.36%). An increase in seroprevalence with age was noted, and more females than males were antibody-positive, though not significantly so. Serum from one donor (1711), originating from Guinea-Bissau, was shown by Western blot and radioimmune precipitation to react with various proteins of HTLV-I, HIV-1 and -2, and SIV. Based on the serologic profiles and isolation of bona fide HTLV-I from her lymphocytes (confirmed by immunologic analysis, molecular cloning of the provirus and restriction enzyme analysis and sequencing of the DNA), together with the reactivity of her sera with an HIV-2 isolate obtained from her husband, we conclude that this donor was doubly infected with HTLV-I and HIV-2, rather than being the host to an as yet unidentified retrovirus.