Morphological alterations caused by manual venom extraction on the main venom gland of Bothrops asper and Crotalus simus snakes (Serpentes: Viperidae): Long-term implications for antivenom production.

The only scientifically validated treatment for snakebite envenomation is the administration of antivenoms. For their production, small quantities of snake venom are injected in animals to elicit a specific antibody response. Snakes are kept in captivity, and their venom is regularly extracted to assure antivenom access. It has already been reported that the pressure exerted upon the venom gland during this extraction can cause tissue damage and fibrosis, leading to a decrease in the venom yield. We described the histopathology of venom glands for B. asper and C. simus snakes used for antivenom production. Based on these reported tissue abnormalities, we quantify the tissue injury by a generated damage-SCORE and fibrosis. A variety of histopathological damages were found such as fibrosis, edema, necrosis, hemorrhage, and formation of anomalous structures, especially in C. simus, which is more prone to suffer severe damage. The level and severity of the damage depend on the frequency and the number of venom extractions. Furthermore, we design an experimental intensive venom extraction scheme with which we could confirm the causality of these effects. In addition to the histopathological damages, the LD50 and biochemical venom composition were also affected giving experimental evidence that the venom extraction not only causes tissue damage but also affects the composition stability and toxicity of the venom. In order to produce quality and effective antivenoms, an improvement of the management of snake collections could be established, such as rotation groups to assure the quality of the venom yielded.

Alteraciones leucocitarias por exposición a perclorato de amonio en ratones de la cepa ICR / Leucocitary changes by ammonium perchlorate in ICR mice strain / Alterações leucocitárias por exposição a perclorato de amônio em camundongos da linhagem ICR

El presente trabajo tuvo como objetivo identificar alteraciones en el recuento de leucocitos en sangre periférica, generadas por la exposición a perclorato de amonio, en ratones de la cepa ICR, evaluando diferentes concentraciones de exposición y diferenciando dichas alteraciones en machos y hembras. Se realizó mediante un trabajo de diseño analítico tipo experimental. Se utilizaron 60 ratones de la cepa ICR, 30 machos y 30 hembras de los cuales 50 fueron expuestos a perclorato de amonio. La manipulación se llevó a cabo de acuerdo con lo establecido en la resolución 008430 de 1993, artículo 87 del Ministerio de Salud de la República de Colombia. Un 70% de los ratones hembra y un 83% de los ratones macho expuestos a perclorato de amonio presentaron alteraciones en el recuento celular de la línea blanca. Los machos presentaron mayor alteración leucocitaria, en especial linfocitopenia. Por otro lado, el peso en los ratones expuestos disminuyó considerablemente hacia la tercera semana de administración de perclorato de amonio, lo cual podría indicar que esta sustancia tóxica genera un estado de inmunosupresión. Se evidenció leucopenia, específicamente neutropenia, neutrofilia y linfocitopenia como principales alteraciones en el recuento de leucocitos en ratones de la cepa ICR, expuestos a perclorato de amonio.

The objective of this work was to identify the changes in the leukocyte counts in peripheral blood by ammonium perchlorate in ICR strain mice, evaluating the different exposure concentrations and differentiating the changes between males and females. Through an analytic experimental investigation, 60 ICR strain mice, 30 males and 30 females were used, 50 of which were exposed to ammonium perchlorate. This study was carried out by Resolution 008430/93, article 87 of Ministry of Health of Colombia. A total of 70% females and 83% males had changes in the leukocyte counts, especially lymphocytopenia in males, further, weight decreased the third week of treatment, and probably that toxic substance induces a state of immunosuppression. The main changes in the leukocyte counts in peripheral blood by ammonium perchlorate in ICR strain was leukopenia.

O objetivo deste trabalho foi identificar as alterações na contagem de leucócitos em sangue periférico, geradas pela exposição a perclorato de amônio em camundongos da linhagem ICR, avaliando diferentes concentrações de exposição e diferenciando estas alterações entre machos e fêmeas. Isto foi realizado através de um trabalho de desenho analítico tipo experimental. Foram utilizados 60 camundongos da linhagem ICR, sendo 30 machos e 30 fêmeas, dos quais 50 foram expostos ao perclorato de amônio. O manuseio foi realizado conforme a resolução 008430 de 1993, artigo 87 do Ministério da Saúde da Colômbia. 70% dos camundongos fêmea e 83% dos machos apresentaram alterações na contagem celular dos leucócitos, especialmente a linfocitopenia em machos. Além disso, o peso nos camundongos expostos diminuiu en forma considerável para a terceira semana de tratamento com perclorato de amônio, o qual poderia indicar que esta substância tóxica gera um estado de imunossupressão. Houve evidência de leucopenia, especificamente neutropenia, neutrofilia e linfocitopenia como principais alterações na contagem de leucócitos em camundongos da linhagem ICR, expostos a perclorato de amônio.

The polyaromatic hydrocarbon ß-naphthoflavone alters binding of YY1, Sp1, and Sp3 transcription factors to the Dp71 promoter in hepatic cells.

The smallest product of the Duchenne muscular dystrophy gene, dystrophin (Dp)71, is ubiquitously expressed in nonmuscle tissues. We previously showed that Dp71 expression in hepatic cells is modulated in part by stimulating factor 1 (Sp1), stimulating protein 3 (Sp3), and yin yang 1 (YY1) transcription factors, and that the polyaromatic hydrocarbon, ß-naphthoflavone (ß­NF), downregulates Dp71 expression. The aim of the present study was to determine whether ß­NF represses Dp71 expression by altering mRNA stability or its promoter activity. Reverse transcription­quantitative polymerase chain reaction was used to measure half­life mRNA levels in ß­NF­treated cells exposed to actinomycin D, an inhibitor of transcription, for 0, 4, 8, 12 and 16 h. Transient transfections with a plasmid carrying the Dp71 basal promoter fused to luciferase reporter gene were carried out in control and ß­NF­treated cells. Electrophoretic mobility shift assays (EMSAs) were performed with labeled probes, corresponding to Dp71 promoter sequences, and nuclear extracts of control and ß­NF­treated cells. To the best of our knowledge, the results demonstrated for the first time that this negative regulation takes place at the promoter level rather than the mRNA stability level. Interestingly, using EMSAs, ß­NF reduced binding of YY1, Sp1, and Sp3 to the Dp71 promoter. It also suggests that ß­NF may modulate the expression of other genes regulated by these transcription factors. In conclusion, ß­NF represses Dp71 expression in hepatic cells by altering binding of YY1, Sp1, and Sp3 to the Dp71 promoter.

Transcription factors YY1, Sp1 and Sp3 modulate dystrophin Dp71 gene expression in hepatic cells.

Dystrophin Dp71, the smallest product encoded by the Duchenne muscular dystrophy gene, is ubiquitously expressed in all non-muscle cells. Although Dp71 is involved in various cellular processes, the mechanisms underlying its expression have been little studied. In hepatic cells, Dp71 expression is down-regulated by the xenobiotic ß-naphthoflavone. However, the effectors of this regulation remain unknown. In the present study we aimed at identifying DNA elements and transcription factors involved in Dp71 expression in hepatic cells. Relevant DNA elements on the Dp71 promoter were identified by comparing Dp71 5'-end flanking regions between species. The functionality of these elements was demonstrated by site-directed mutagenesis. Using EMSAs and ChIP, we showed that the Sp1 (specificity protein 1), Sp3 (specificity protein 3) and YY1 (Yin and Yang 1) transcription factors bind to the Dp71 promoter region. Knockdown of Sp1, Sp3 and YY1 in hepatic cells increased endogenous Dp71 expression, but reduced Dp71 promoter activity. In summary, Dp71 expression in hepatic cells is carried out, in part, by YY1-, Sp1- and Sp3-mediated transcription from the Dp71 promoter.