Relationship between superovulation and embryo production with ovarian follicular population before superovulatory treatment in Brazilian Bergamasca sheep / [Relação da resposta superovulatória e produção embrionária com a população folicular ovariana antes do tratamento superovulatório de ovelhas da raça Bergamácia Brasileira]

The objective of this study was to quantify the superovulatory response and embryo production of Brazilian Bergamasca sheep and to evaluate the link to the follicular condition before superovulatory treatment, as a reference for selection of donors with potential for superovulation. Follicular population of twenty-three sheep was evaluated by ultrasound during metestrus phase of the estrous cycle and divided into groups of low, medium and high follicular population. Subsequently, they were synchronized, superovulated with 133mg of pFSH, mated and subjected to embryo collection. The superovulatory response (9.0±3.3 vs 10.7±6.2 vs 13.8±7.1) and embryo production (4.0±3.8 vs 2.6±2.0 vs 1,8±4.0) were similar between groups (P>0.05). There was a positive correlation between the number of follicles during the metestrus phase and the number of corpus luteum with premature regression (PLR) (0.52) and a negative correlation between the recovery rate and PLR (-0.44) (P<0.05). The sheep that presented PLR had more follicles during metestrus (16.9±7.8 vs 12.7±3.2) and lower embryo recovery rate (38.8±29.3 vs 72.2±29.9) than those with functional CLs (P<0.05). Follicular quantification during metestrus phases was unable to identify donors with high embryo production. Animals with PLR had a larger follicular population during metestrus and lower embryo recovery rate.(AU)

O objetivo deste trabalho foi quantificar a resposta superovulatória e a produção embrionária de ovelhas Bergamácia Brasileira e relacioná-las com a condição folicular antes do tratamento superovulatório, como referência para seleção de doadoras com potencial para superovulação. Vinte e três ovelhas foram avaliadas quanto à população folicular por ultrassonografia na fase de metaestro do ciclo estral e divididas em grupos com baixa, média e alta população folicular. Posteriormente foram sincronizadas, superovuladas com 133mg de pFSH, acasaladas e submetidas à coleta de embriões. A resposta superovulatória (9,0±3,3 vs. 10,7±6,2 vs. 13,8±7,1) e a produção embrionária (4,0±3,8 vs. 2,6±2,0 vs. 1,8±4,0) foram semelhantes entre os grupos (P>0,05). Houve correlação positiva entre o número de folículos no metaestro e o número de corpos lúteos com regressão prematura (RPCL) (0,52) e correlação negativa entre a taxa de recuperação e RPCL (-0,44) (P <0,05). As ovelhas que apresentaram RPCL tiveram mais folículos no metaestro (16,9±7,8 vs. 12,7±3,2) e menor taxa de recuperação embrionária (38,8±29,3 vs. 72,2±29,9) do que as que apresentaram CLs funcionais (P<0,05). A quantificação folicular nas fases de metaestro não foi capaz de identificar doadoras com alto potencial de produção embrionária. Animais com RPCL tiveram maior população folicular no metaestro e menor recuperação de embriões.(AU)

Unexpected brain lesions in lactating Sprague-Dawley rats in a Two-generation Inhalation Reproductive Toxicity Study with pentafluoropropane (HFC-245fa).

The study presented was conducted following the reproductive study guideline OECD Guideline 416 Two-Generation Reproduction Toxicity Study. Sprague-Dawley rats were exposed to 2000, 10,000 and 50,000 ppm of HFC-245fa. There was an unexpected mortality of lactating dams in the medium and high dose group beginning at day 10 of lactation. Statistically significant histopathological alterations were observed in the cerebellum of a total of 9/30 females of the high dose group of the F0-generation and in 10/27 females of the high dose group of the F1-generation. In contrast there were no brain lesions found in males or non-pregnant females of all dose groups. Neuronal necrosis and degeneration in the cerebellar cortex were observed as the most severe finding. Furthermore vacuolation of the neuropil in different degrees was diagnosed in 7/30 females of the F0-generation and in 9/30 females of the F1-generation. Acute hemorrhages - in particular perivascular - occurred in 5/30 females of the F0- and in 5/30 females of the F1-generation indicating a disturbed vascular integrity. The main lesions found in the cerebrum were glial scars in the corpus callosum and restricted to 2/30 females of the F0-generation of the high dose group. The increased incidence of myocardial fibrosis and mononuclear cell infiltration in males - indicating myocarditis - was only seen in the F0-generation of the high dose group. Females of the F1-generation of the high dose group showed an increased incidence of minimal myocardial fibrosis. In summary, histopathology revealed that the brain, particularly the cerebellum, and to a minor degree the heart turned out to be the toxicological target organs of the substance. Presumably substance-related energy deprivation may be responsible for the observed changes. One of the metabolites, 3,3,3-trifluoropropanoic acid has been shown to be capable of causing this effect.

Regulation of the Arabidopsis thaliana aquaporin gene AthH2 (PIP1b).

Arabidopsis thaliana was transformed with constructs composed of the aquaporin AthH2 promoter and the coding sequence of beta-glucuronidase (GUS) as reporter gene. The transgenic plants obtained were treated with different light qualities or phytohormones and the activity of the AthH2 promoter was determined in situ using a specific GUS assay. With blue light (400-550 nm) and white light, significant activation of the promoter was observed. The same was true for the application of gibberellic acid (GA) and abscisic acid (ABA). In contrast, red light and indole-3-acetic acid (IAA) had only minor effects on the promoter activity. The significance of sequence elements with relation to GA or ABA was confirmed by deletion analyses of the AthH2 promoter. Likewise, a promoter segment with importance for hydathoid specific expression was identified.

The blue light-responsive AthH2 gene of Arabidopsis thaliana is primarily expressed in expanding as well as in differentiating cells and encodes a putative channel protein of the plasmalemma.

According to our previous studies the Arabidopsis gene AthH2 which is inducible by blue light and phytohormones codes for an intrinsic membrane protein. It bears a resemblance to several distinct channel proteins of plant and animal species classified as the MIP/NOD-26/GlpF family. In the present study biochemical analyses and electron microscopic immunochemistry were used to elucidate the subcellular location of the AthH2 protein. The results clearly demonstrate that it is an exclusive constituent of the plasmalemma. Furthermore, the expression of the AthH2 gene in transgenic Arabidopsis plants containing the promoter region of AthH2 fused to the beta-glucuronidase (gus) reporter gene was studied. The in situ localization of gus activity revealed that the specific promoter is temporally activated by light in expanding and/or differentiating cells comprising newly formed tissues and organs: root elongation zone, guard cells of stomata, vascular bundle sheaths, filaments of stamen and young siliques. Several sites of gus expression coincide spatially with those of in situ hybridization and the immunocytochemical reaction, respectively, suggesting that the AthH2 promoter had correctly responded to light as an important exogenous factor with relevance to the complex pattern of differentiation. Studies with protoplasts from plants transformed with an antisense construct revealed a water transport capacity of the AthH2 protein.

Membrane fluidity of microsomal and thymocyte membranes after X-ray and UV irradiation.

A brief literature review shows that ionizing radiation in biological membranes and in pure lipid membranes causes malondialdehyde formation, indicating lipid peroxidation processes. With respect to membrane fluidization by ionizing radiation, in pure lipid membranes rigidization effects are always reported, whereas contradictory results exist for biological membranes. Starting from the assumption that membrane proteins at least partly compensate for radiation effects leading to a rigidization of membrane lipid regions, pig liver microsomes, as a representative protein-rich intracellular membrane system, were irradiated with X-rays or UV-C with doses up to 120 Gy at a dose rate of 0.67 Gy min-1 and up to 0.73 J cm-2 at an exposure rate of 16.2 mJ cm-2 min-1, respectively. For both irradiation types a weak but significant positive correlation between malondialdehyde formation and membrane fluidity is revealed throughout the applied dose ranges. We conclude that the membraneous protein lipid interface increases its fluidity under radiation conditions. Also, thymocyte ghosts showed an increased fluidity after X-ray irradiation. Fluidity measurements were performed by the pyrene excimer method.

A novel blue light- and abscisic acid-inducible gene of Arabidopsis thaliana encoding an intrinsic membrane protein.

Continuous irradiation with blue light (400-500 nm) induces flower formation in plantlets of Arabidopsis thaliana (C24) while red light (600-700 nm) is ineffective. This observation started a search for genes that are activated by blue light and initiate the morphogenic programme leading to flower formation. Several genes were identified via their cDNAs. From these clone AthH2, with an open reading frame for a hydrophobic 30.5 kDa polypeptide, was selected for further characterization of the corresponding gene. From a genomic library a DNA fragment of about 6.4 kb was isolated, comprising the coding region as well as 5'-upstream and 3'-downstream flanking segments. The coding region is composed of four exons, which specify a polypeptide of 286 amino acids. Several potential regulatory elements were found between position -670 and -1140 including GA and ABA sequence motifs. The latter could account for the observed induction of the AthH2 gene by ABA. Southern blot analysis of Arabidopsis genomic DNA suggests that the AthH2 gene is encoded by a single-copy gene. Hydropathy plots and secondary structure analysis of the putative polypeptide predict six membrane-spanning domains implicating a function as transmembrane channel protein. It displays significant homology with the proteins TR7a of pea (82%) and RD 28 of A. thaliana (68%).

Indication of an antipsychotic action of the opiate antagonist naloxone.

In 20 psychotic patients with frequent hallucinations and/or actual delusional experience a possible antipsychotic action of the opiate antagonist naloxone (N-allyl-noroxymorphone) was investigated, using a double-blind placebo-controlled cross-over design. 18 of these patients were not treated with neuroleptic drugs; 13 suffered from an acute episode of schizophrenia. Psychopathological changes were assessed by the use of the IMPS-scale and of a symptom-specific rating scale (VBS). Intravenous injection of naloxone (in most cases 4.0 mg) induced a reduction of psychotic symptomatology (especially hallucinations) in the majority of patients. Compared with placebo this effect reached statistical significance within 2-7 hours after injection. From this result a possible involvement of endogenous ligands of opiate receptors in the pathogenesis of schizophrenia may be concluded.