Abstract in English:Brazilian flora is very rich and a large number of specimens can cause adverse reactions, from mild erythema to cutaneous necrosis. Plants or vegetal extracts are always suspected of contact dermatitis; they are found in all types of environments, including dwellings. Other harmful effects, which can be identified by clinical manifestations and the aid of the patient, are phytophotodermatitis, traumas, thorn infections, chemical irritations, or urticaria caused by Urtica sp. Knowledge on the most important plants and their effects on human skin are very useful, and diagnosis is very important in treatment of the complications.
Abstract in English:Equine leptospirosis can present a non-symptomatic form, an acute clinical form, or even develop chronically, causing reproductive alterations, such as abortion and recurrent uveitis. Since the prevalence of leptospirosis in several countries and regions is widely reported, the objective of this study was to verify the prevailing equine leptospirosis in different regions of Brazil. Sera from 1402 blood samples from horses of different age, sex, breed, and purpose were examined. These samples came from southeastern and central west states of Brazil. The method utilized was the Microscopic Agglutination Test (MAT), with 12 different Leptospira serovars. From the sera tested, 754 (54%) were positive for one (385) or more (372) serovars. These results were higher when compared to national and international levels. The most commonly found serovars were icterohaemorrhagiae (37.01%), suggesting exposure to rodents, castellonis (16.97%), and djasiman (15.19%). There were significant differences of reagents between sexes, and a tendency toward higher positivity with age. Distribution of sera-reagents related to aptitude showed a markedly higher value for work animals than for sporting ones. Higher rates were found for animals with undefined breed. There were no significant differences related to regional origin. As an indication of multiple exposure, significant associations were observed between the following serovars: castellonis and djasiman; castellonis and grippotyphosa; castellonis and copenhageni; castellonis and icterohaemorrhagiae; castellonis and pomona; canicola and pomona; canicola and djasiman; djasiman and copenhageni; icterohaemorrhagiae and djasiman; icterohaemorrhagiae and pyrogenes; copenhageni and pomona. These results showed the necessity of further studies on the epidemiology of this disease in equines and its relationship to human illness.
Abstract in English:We investigated the in vitro process of cell death caused by Egyptian cobra venom on primary human embryonic kidney (293T) and mouse myoblast (C2C12) cell lines. The aim of these studies was to provide further information about triggering cell death, and suggest methods for eliminating unwanted cells, such as tumour cells. Both cell lines were treated with 10, 20, and 50 m g/ml of Egyptian cobra (Naja haje) venom in serum free media (SFM) and incubated for 8 hours. Total activities of the lactate dehydrogenase (LDH) and creatine kinase (CK) released in the culture during venom incubation were used as an indicator of the venom in vitro cytotoxicity. Cell injury was morphologically recognized and apoptosis determined by a Fluorescing Apoptosis Detection System and confirmed by staining nuclear DNA with DAPI. Our data clearly demonstrated marked cytotoxic effects and acute cell injury for both cell lines. Release of LDH and CK into the culture media induced by the venom correlates well with the morphological changes and extent of cell death. Mostly, these consequences were time and dose-dependent in both cell lines. The results obtained from this study indicated that cobra venom cause cell death by two different mechanisms: necrosis and induction of apoptosis. The apoptotic mechanism, accompanied by cell necrosis, mediated cell destruction of both tested cell lines; however, necrosis was predominant in the C2C12 cell line while apoptosis, in 293T cells. This unusual form of cell death induced by cobra venom may represent a combination of apoptosis and necrosis within the same cell. This is a first-hand investigation showing the apoptotic effects of N. haje venom at the cellular level. However, the contribution of the apoptotic pathway may be dependent on concentration and/or time of exposure to snake venom.
Abstract in English:Components with phospholipase A2 activity were isolated by gel filtration and cationic exchange chromatography from the venom of Bothrops asper snakes from Chiriguaná, Colombia (9°22´N; 73°37´W). Five fractions were obtained by the gel filtration, and PLA2 activity was found in fraction 3 (F3). In the cationic exchange chromatography, F3 showed eight components with PLA2 activity. Six of these components appeared as one band in polyacrylamide gel electrophoresis (SDS-PAGE). Fractions II and VII exhibited an optimal activity at pH 9 and 52ºC. The optimum calcium concentration for fraction II was 48 mM and for fraction VII, 384 mM. Both fractions showed thermal stability. Fraction II was stable at pH values between 2.5 and 9, and fraction VII, between 2.5 and 8. The Michaelis Menten constant (K M) was 3.5x10-3 M for fraction II and 1.6x10-3 M for fraction VII. The molecular weight was 16,000 Dalton for fraction II and 17,000 Dalton for fraction VII. Both isoenzymes did not show any toxic activity (DL50) at 5.3 and 4 µg/g. The two fractions showed different kinetic constant (K M), calcium requirement, and substrate specificity for haemolytic activity.
Abstract in English:This paper describes a brief study on the crotoxin mechanism of action, regarding the transport of GABA and L-glutamate in rats cortico-cerebral synaptosomes and in heterologous systems, such as COS-7 cells expressing gabaergic transporters, and C6 glioma cells and Xenopus oocytes expressing glutamatergic transporters. Crotoxin concentrations over 1 µM caused an inhibitory effect of ³H-L-glutamate and ³H-GABA, and reversibly inhibited L-glutamate uptake by C6 glioma cells. When COS-7 cells were assayed, no inhibition of the ³H-GABA transport could be evidenced. Crotoxin kept its inhibitory effect on neurotransmitters uptake even when Ca2+ ions were removed from the medium, therefore, independently of its PLA2 activity. In addition, high concentrations (2 mM) of BPB did not avoid the action of crotoxin on the neurotransmitters uptake. Crotoxin also inhibited ³H-L-glutamate, independently on Na+ channel blockade by TTX. In addition, an evaluation of the lactic dehydrogenase activity indicated that uptake inhibition does not involve a hydrolytic action of crotoxin upon the membrane. We may also suggest that crotoxin acts, at least partially, altering the electrogenic equilibrium, as evidenced by confocal microscopy, when a fluorescent probe was used to verify cell permeability on C6 glioma cells in presence of crotoxin.
Abstract in English:Ten out of eighty-nine strains biochemically identified as Clostridium perfringens, isolated from bovine organs, were selected by their different results showed in toxigenicity test on mice. Those and the standard strains, ATCC types A, B, C, and D, had their virulence exalted through serial intramuscular inoculation into guinea pigs. Results showed that, for toxigenic strains (6), one or two passages were enough to cause exaltation, while for the atoxigenic (4), five or six inoculations were needed. Esterase electrophoresis of standard and isolated strains, with and without exaltation, was performed. Electrophoresis analysis permits the following conclusions: strains that do not show any clinical symptoms in mice, when exalted demonstrate decreased esterase activity; on the contrary, it is increased when correlated with animal symptoms.
Abstract in English:Seventy-nine HIV-1 infected patients were studied in three groups: Group G1 - 11 patients with no antiretroviral therapy; G2 - 40 patients undergoing antiretroviral therapy, 33 with only two nucleoside reverse transcriptase inhibitors (NRTI), and seven with two NRTI and one protease inhibitor (PI), all with viral load (VL) equal or higher than 80 copies of plasma RNA/ml; Group G3 - 28 patients, 23 on highly active antiretroviral therapy (HAART), 18 with two NRTI and one PI, and five with two NRTI and one non-nucleoside reverse transcriptase inhibitor (NNRTI), the remaining five with combination of two NRTI. All G3 patients had undetectable viral load for at least the past six months. The control group (Gc) included 20 normal blood donors without clinical complaints or signs of disease and negative for anti-HIV-1/2 antibodies. Serum cytokine levels pg/ml (TNF-alpha, INF-gamma, IL-2, IL-4, and IL-10) were determined in all patients including controls. CD4+ T and CD8+ T lymphocyte counts were made in the 79 patients by flow cytometry; VL determination was by NASBA technology. Analysis of results showed that the number of CD4+ T and CD8+ T lymphocytes were higher in G2 than G1, while VL was 0.5 log lower. G3 patients had similar lymphocyte values to G2, however they were chosen for G3 because their VL was undetectable, different by 4.0 log to G2. These results show the effect of antiretroviral treatment in G2 and G3 patients with better performance in the latter. Statistical difference was seen between the three groups and controls for serum cytokine behavior: TNF-alpha [H=48.323; p<0.001;(G1=G2=G3)>Gc]; INF-gamma[H=28.992; p<0.001; (G1=G2=G3)>Gc]; IL-4[H=48.323; p<0.001; (G1=G2=G3)>Gc]; IL-10[H=47.256; p<0.001; (G1=G2=G3)>Gc. There was no statistical difference in IL-2 values between all groups (H=6.071; p>0.10; G1=G2=G3=Gc). In absolute values however, G3 showed slightly lower TNF-alpha, IL-4, and IL-10, and higher INF-gamma and IL-2, to G1 and G2. This suggests a better performance in G3 patients, especially in IL-2 behavior. For cytokine profile, the three groups showed mature Th0 subset. In G1 72.73% were mature Th0, and 27.27% Th2; G2, 72.50% mature Th0, and 27.50% Th2; and G3, 89.29% mature Th0, and 10.71% Th2. There was no statistical difference between groups (chi22=3.014; p>0.10; G1=G2=G3). Statistical difference was seen between G2 and G3 for antiretroviral regimes used (chi21=27.932; p<0.001; G3>G2); HAART with PI predominated in G3, suggesting that it was responsible for this better performance. Linear correlation between pairs of variables was made with patient groups only, excluding controls. This was made separately for G1 and G2, 51 patients with detectable VL, and G1, G2, and G3 also including those with undetectable VL. The results showed a strong positive correlation between TNF-alpha and IL-4; TNF-alpha and IL-10; INF-gamma and IL-2; IL-4 and IL-10; IL-2 and CD4+. Weak negative correlation was seen between IL-2 and VL. Considering all correlations together, we found that IL-2 had the most correlations - eleven - strong, weak, positive, and negative; it was the only one that correlated with CD4+ (positively) and LV (negatively). The number of correlations allowed us to evaluate qualitative aspects such as IL-2 correlated positively with INF-gamma and CD4+ and negatively with LV; this somehow expresses the compatible profile with subset Th1, which could signify a tendency towards immune response recovery. Determination of cytokine serum values, especially IL-2, could be useful in follow-up of HIV-1 infected patients under HAART together with CD4+ and VL count.
Abstract in English:Snakebites are endemic in some parts of India, being associated with a number of complications. Ocular disturbances are rare, except for injury to the cornea or conjunctiva when the eye is directly exposed to the venom. In this work, we present a case of central retinal artery occlusion caused by snakebite.