Distribution of rabies virus in infected mice, vaccinated and submitted to P-acnes as immunomodulator

The lethality and distribution of rabies virus were evaluated in swiss mice experimentally infected with street rabies virus, vaccinated and submitted to immunomodulation by P. acnes (formerly Corynebacterium parvum). The animals were sacrificed at different times,when the different tissues were collected and submitted to fluorescent antibody test (FAT) and mouse inoculation test (MIT). The group submitted to vaccination and P. acnes treatment presented a percentage of survival superior to that observed in infected mice only treated with P. acnes. Control infected animals had the lowest survival rates. The distribution of rabies virus in spleen of infected mice, vaccinated and submitted to P. acnes was superior to that verified in infected mice not treated with P. acnes. The increased survival correlated with the distribution of rabies virus in lymphoid tissues, could be interpreted as the consequence of P. acnes activity on macrophages. The results suggest the role of macrophages against rabies virus infection in mice and the importance of vaccination in the post expositive treatment of rabies. (C) 2002 Published by Elsevier B.V. Ltd.

Molecular and functional characterization of a new non-hemorrhagic metalloprotease from Bothrops jararacussu snake venom with antiplatelet activity

BjussuMP-II is an acidic low molecular weight metalloprotease (Mr similar to 24,000 and pI similar to 6.5), isolated from Bothrops jararacussu snake venom. The chromatographic profile in RP-HPLC and its N-terminal sequence confirmed its high purity level. Its complete cDNA was obtained by RT-PCR and the 615 bp codified for a mature protein of 205 amino acid residues. The multiple alignment of its deduced amino acid sequence and those of other snake venom metalloproteases showed a high structural similarity, mainly among class P-I proteases. The molecular modeling analysis of BjussuMP-II showed also conserved structural features with other SVMPs. BjussuMP-II did not induce hemorrhage, myotoxicity and lethality, but displayed dose-dependent proteolytic activity on fibrinogen, collagen, fibrin, casein and gelatin, keeping stable at different pHs, temperatures and presence of several divalent ions. BjussuMP-II did not show any clotting or anticoagulant activity on human citrated plasma, in contrast to its inhibitory effects on platelet aggregation. The aspects broached, in this work, provide data on the relationship between structure and function, in order to better understand the effects elicited by snake venom metalloproteases. (c) 2007 Elsevier B.V. All rights reserved.

Geographic variations in the composition of myotoxins from Bothrops neuwiedi snake venoms: biochemical characterization and biological activity

(1) Venom pools from Bothrops neuwiedi (Bn) and from two subspecies, namely Bothrops neuwiedi pauloensis (Bnp) and Bothrops neuwiedi urutu (Bnu), collected in the States of São Paulo (SP) and Minas Gerais (MG), Brazil, were electrophoretically examined. Basic toxins with different isoelectric points were identified in the venom collected in São Paulo (BnSP). These toxins were absent in the corresponding pools from Minas Gerais (BnMG, BnpMG and BnuMG). (2) BnSP, but not BnMG, BnpMG or BnuMG, showed two myotoxins (pI congruent to 8.6 and 8.8, respectively) which were isolated by ion-exchange chromatography on CM-Sepharose. (3) From BnMG, three myotoxic isoforms (pI congruent to 8.2 and M-r = 13600) were isolated by chromatography on CM-Sepharose followed by reversed-phase high-performance liquid chromatography. (4) the chemical and biological characterization of these toxins showed a high similarity with the Lys-49 myotoxins from other bothropic venoms. (5) Doses up to 5 LD50 (i.p.) of p-bromophenacyl bromide alkylated BnSP-7 caused a total loss of lethality in 18-22-g mice, thus indicating that the LD50 was increased by greater than 5-fold. At this dose myotoxicity was also not detectable, but the edematogenic activity on the rat paw apparently did not change. (C) 1998 Elsevier B.V. All rights reserved.

Brine shrimp (Artemia salina Leach) bioassay of extracts from Lychnophoriopsis candelabrum and different Lychnophora species

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

The chelation of metal ions by the acylpolyamine toxins from the web-spider Nephilengys cruentata: effects in the intoxication/detoxification of preys

Orb-web-spiders present a series of different strategies for prey capture, involving the use of different types of silk for web building, the use of adhesive traps in the webs, the secretion of toxic compounds to the spider's preys in the adhesive coating of the capture web and the biosynthesis of a wide range of structurally related acylpolyamine toxins in their venoms. The polyamine toxins usually block neuromuscular junctions and/or the central nervous system (CNS) of Arthropods, targeting specially the ionotropic glutamate receptors; this way these toxins are used are as chemical weapons to kill / paralyze the spider's prey. Polyamine toxins contain many azamethylene groups involved with the chelation of metal ions, which in turn can interact with the glutamate receptors, affecting the toxicity of these toxins. It was demonstrated that the chelation of Ni+2, Fe+2, Pb+2, Ca+2 and Mg+2 ions by the desalted crude venom of Nephilengys cruentata and by the synthetic toxin JSTX-3, did not cause any significant change in the toxicity of the acylpolyamine toxins to the model-prey insect (honeybees). However, it was also reported that the chelation of Zn+2 ions by the acylpolyamines potentiated the lethal / paralytic action of these toxins to the honeybees, while the chelation of Cu+2 ions caused the inverse effect. Atomic absorption spectrometry and Plasma-ICP analysis both of N.cruentata venom and honeybee's hemolymph revealed that the spider's venom concentrates Zn+2 ions, while the honeybee's hemolymph concentrates Cu+2 ions. These results are suggesting that the natural accumulation of Zn+2 ions in N. cruentata venom favors the prey catching and/or its maintenance in the web, while the natural accumulation of Cu+2 ions in prey's hemolymph minimizes the efficiency of the acylpolyamine toxins as killing/paralyzing tool.

Crystallization and preliminary X-ray analysis of bucain, a novel toxin from the Malayan krait Bungarus candidus

Bucain is a three-finger toxin, structurally homologous to snake-venom muscarinic toxins, from the venom of the Malayan krait Bungarus candidus. These proteins have molecular masses of approximately 6000-8000 da and encompass the potent curaremimetic neurotoxins which confer lethality to Elapidae and Hydrophidae venoms. Bucain was crystallized in two crystal forms by the hanging-drop vapour-diffusion technique in 0.1 M sodium citrate pH 5.6, 15% PEG 4000 and 0.15 M ammonium acetate. Form I crystals belong to the monoclinic system space group C2, with unit-cell parameters a = 93.73, b = 49.02, c = 74.09 Angstrom, beta = 111.32degrees, and diffract to a nominal resolution of 1.61 Angstrom. Form II crystals also belong to the space group C2, with unit-cell parameters a = 165.04, b = 49.44, c = 127.60 Angstrom, beta = 125.55degrees, and diffract to a nominal resolution of 2.78 Angstrom. The self-rotation function indicates the presence of four and eight molecules in the crystallographic asymmetric unit of the form I and form II crystals, respectively. Attempts to solve these structures by molecular-replacement methods have not been successful and a heavy-atom derivative search has been initiated.

Isobutyl amides - potent compounds for controlling Diatraea saccharalis

BACKGROUND: A dichloromethane-methanol extract of the seeds of Piper tuberculatum Jacq. (Piperaceae) and two isobutyl amides, 4,5-dihydropiperlonguminine (1) and pellitorine (2), which were isolated by chromatographic methods, were assayed for their lethality against the sugarcane borer Diatraea saccharalis F. (Lepidoptera: Pyralidae).RESULTS: Bioassays were carried out with fourth-instar caterpillars through topical application of test solutions to the dorsal surface of the prothorax, and dose-response correlations were determined. Significant insect mortalities were observed 24, 48 and 72 h after treatment at concentrations of >= 100 mu g insect(-1). The LD(50) and LD(90) values for compound 1 were 92.83 and 176.50 mu g insect(-1), and for compound 2 they were 91.19 and 184.56 mu g insect(-1).CONCLUSION: According to the LD(50) and LD(90) for compounds 1 and 2, it can be inferred that the values reflect an acute lethal response to both compounds, based on interaction(s) of the toxicants with a primary target or series of targets. Thus, the amides were demonstrated to have potential value in the control of the sugarcane borer. (C) 2008 Society of Chemical Industry

Surtos de botulismo em bovinos no Brasil associados à ingestão de água contaminada

Botulismo em bovinos resulta da ingestão de toxina previamente formada. No presente trabalho são descritos sete surtos da intoxicação onde os dados clínico-patológicos, epidemiológicos e os achados laboratoriais indicaram a possível ingestão da toxina através da água contaminada. O coeficiente médio de mortalidade foi de 20,1%, com letalidade de 99,92%, e morbidade de 31,62%. Dos cerca de 9.000 bovinos envolvidos nos surtos, 2.844 morreram com quadro clínico predominantemente superagudo e agudo. A alta morbidade e mortalidade foram registradas num curto período de tempo e envolveram todas as categorias animais, com quadro clínico-patológico caracterizado por paresia e paralisia da musculatura da locomoção, deglutição e mastigação e ausência de lesões macroscópicas. As circunstâncias em que ocorreram os surtos estiveram relacionadas com a existência de carcaças de animais decompostas ou matéria orgânica vegetal na água de dessedentação. Foram detectadas toxinas botulínicas C e/ou D nas coleções de água, nas vísceras e no soro sangüíneo de parte considerável dos materiais examinados.

Botulismo em bovinos de corte e leite alimentados com cama de frango

Surtos de botulismo causados pelos tipos C e D da toxina botulínica são freqüentes no país, estando originalmente associados à osteofagia e à ingestão de alimentos e água contaminados. No presente trabalho são descritos os aspectos epidemiológicos, clínico-patológicos e laboratoriais de sete surtos da intoxicação em bovinos de corte e leite alimentados com cama de frango, ocorridos nos estados de São Paulo e Minas Gerais entre 1989 e 2000. Cinco surtos ocorreram em rebanhos de corte confinados ou criados extensivamente e suplementados com o subproduto, e dois em propriedades leiteiras. de um total de 1.535 animais alimentados regularmente com a cama de frango, 455 (29,64%) morreram em um período que variou de 2 a 4 semanas. A morbidade nos sete surtos estudados variou de 3,47 a 100%, da mesma forma que a mortalidade. em uma das propriedades a letalidade foi de 60,52%, e em todos os outros surtos ela foi acima de 88,43%; em três propriedades o coeficiente foi de 100%. Os sinais clínicos de paralisia progressiva, dificuldade na locomoção, decúbito e estado mental aparentemente normal, diminuição do tônus da musculatura da língua e cauda, sialorréia e dificuldade respiratória caracterizaram o quadro clínico. À necropsia de 30 animais não foi observada qualquer alteração macroscópica digna de nota. A presença de esporos de Clostridium botulinum foi detectada em amostras de cama de frango colhidas nas sete propriedades. Nas amostras de fígado, líquido ruminal e intestinal, provenientes dos 30 animais necropsiados, foi possível detectar toxinas botulínicas tipos C (5) ou D (9), ou classificada como pertencente ao complexo CD (1), em pelos menos um dos materiais provenientes de 15 animais, confirmando assim o diagnóstico clínico-patológico e epidemiológico de botulismo.

Febre catarral maligna em bovinos do Mato Grosso do Sul e de São Paulo

São descritos a epidemiologia, os sinais clínicos, os achados de necropsia e a histopatologia de seis casos de febre catarral maligna (FCM) em bovinos de 5 fazendas localizadas nos estados de Mato Grosso do Sul e São Paulo. A doença ocorreu em bovinos de ambos os sexos e com idades variando de 4 meses a 11 anos. Os índices de morbidade variaram de 0,25% a 6.6% e a letalidade foi de 100%. A evolução clínica foi aguda (2-3 dias) em seis casos e crônica em um (3 meses). O diagnóstico presuntivo de FCM nos casos descritos neste relato foi baseado nos sinais clínicos, achados de necropsia e confirmados pela histopatologia. Os principais sinais clínicos nos casos agudos foram febre, corrimento mucopurulento pelas fossas nasais, opacidade da córnea, sialorréia, úlceras em várias superfícies mucosas e distúrbios nervosos. O bovino do caso crônico mostrou opacidade da córnea e distúrbios neurológicos. Os principais achados de necropsia incluíam hiperemia e lesões diftéricas em várias superfícies epiteliais e a histopatologia consistiu de vasculite, focos de infiltrado mononuclear multifocal em vários órgãos e necrose de superfícies epiteliais.

Ocorrência de infecção hospitalar em idosos internados em hospital universitário

OBJETIVO: A infecção hospitalar é uma importante causa de morbidade e mortalidade na população idosa. O estudo realizado teve como objetivo avaliar a ocorrência e os fatores de risco da infecção hospitalar. MÉTODOS: Realizou-se estudo prospectivo em uma amostra de 322 idosos com 60 anos e mais, internados em um hospital universitário, entre setembro de 1999 e fevereiro de 2000. O cálculo da amostra foi feito pela fórmula de Fisher e Belle, com intervalo de confiança de 0,95%, de um total de 760 idosos internados, proporcionalmente ao número de pacientes em cada unidade de internação, no ano de 1997. Os critérios para definição da infecção hospitalar foram os do Center for Diseases and Prevention Control. Para a análise estatística dos dados foram utilizados o odds ratio e regressão logística. RESULTADOS: A taxa de infecção hospitalar encontrada foi de 23,6%. As topografias prevalentes de infecção hospitalar foram infecção respiratória (27,6%), do trato urinário (26,4%) e do sítio cirúrgico (23,6%). O tempo de internação dos pacientes sem infecção hospitalar foi de 6,9 dias e dos com infecção hospitalar foi de 15,9 (p<0,05). A taxa de mortalidade dos pacientes internados foi de 9,6% e a de letalidade dos pacientes com infecção hospitalar de 22,9% (p<0,05). Os fatores de risco encontrados para infecção hospitalar foram colangiografia (odds ratio (OR)=46,4, intervalo de confiança 95% (IC 95%)=4,4-485); diabetes melito (OR=9,9, IC 95%=4,4-22,3); doença pulmonar obstrutiva crônica (OR=8,3, IC 95%=2,9-23,7); cateterismo urinário (OR=5, IC 95%=2,7-11,8); internação com infecção comunitária (OR=3,9, IC 95%=1,7-8,9) e ventilação mecânica (OR=3,8, IC 95%=1,9-6,3). CONCLUSÕES: A infecção hospitalar apresentou incidência e letalidade elevadas e aumentou o tempo de internação dos idosos estudados.

Dissociation of enzymatic and pharmacological properties of piratoxins-I and -III, two myotoxic phospholipases A(2) from Bothrops pirajai snake venom

Piratoxins (PrTX) I and III are phospholipases A(2) (PLA(2)s) or PLA(2) homologue myotoxins isolated from Bothrops pirajai snake venom, which also induce myonecrosis, bactericidal activity against Escherichia coli, disruption of artificial membranes, and edema. PrTX-III is a catalytically active hemolytic and anticoagulant Asp49 PLA(2), while PrTX-I is a Lys49 PLA, homologue, which is catalytically inactive on artificial substrates, but promotes blockade of neuromuscular transmission. Chemical modifications of His, Lys, Tyr, and Trp residues of PrTX-I and PrTX-III were performed, together with cleavage of the N-terminal octapeptide by CNBr and inhibition by heparin and EDTA. The lethality, bactericidal activity, myotoxicity, neuromuscular effect, edema inducing effect, catalytic and anticoagulant activities, and the liposome-disruptive activity of the modified toxins were evaluated. A complex pattern of functional differences between the modified and native toxins was observed. However, in general, chemical modifications that significantly affected the diverse pharmacological effects of the toxins did not influence catalytic or membrane disrupting activities. Analysis of structural changes by circular dichroism spectroscopy demonstrated significant changes in the secondary structure only in the case of N-terminal octapeptide cleavage. These data indicate that PrTX-I and PrTX-III possess regions other than the catalytic site, which determine their toxic and pharmacological activities. (C) 2001 Academic Press.

Understanding the in vitro neuromuscular activity of snake venom Lys49 phospholipase A(2) homologues

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Epidemiology of neurocysticercosis in Brazil

A revision of literature was done with the objective of tracing an epidemiologic profile of neurocysticercosis (NCC) in Brazil. The prevalence was 0.12-9% in autopsies. The frequency was 0.03-7.5% in clinical series and 0.68-5.2% in seroepidemiological studies. The disease corresponds to 0.08-2.5% of admissions to general hospitals. Patient origin was rural in 30 63% of cases. The most involved age range (64-100%) was 11 to 60 years, with a predominance (22-67%) between 21 and 40 years. The male sex was the most affected (51-80%). In the severe forms there was a predominance of urban origin (53-62%) and of the female sex (53-75%). The period of hospitalization ranges from 1 to 254 days and 33 to 50% of patients suffer 1.7 ± 1.4 admissions. The clinical picture was variable, with a predominance of epileptic syndrome (22-92%) and intracranial hypertension (19-89%). Psychiatric manifestations were associated in 9-23% of patients. Lethality was 0.29% in terms of all diseases in general and 4.8-25.9% in terms of neurologic diseases. The asymptomatic form was detected in 6% of patients in clinical serie and in 48.5% of case from autopsies The racemose form and ventricular localization also was observed as asymptomatic form. Among the patients with cutaneous cysticercosis 65% of them showed neurologic manifestations.

Paracoccidioidomycosis: Survey and clinical aspects from the Department of Dermatology of the School of Medicine of Botucatu (Sao Paulo - Brazil)

Background - Paracoccidioidomycosis is the most frequent among the systemic mycoses in Brazil. Objective: To study the cases of paracoccidioidomycosis diagnosed from 1976 to 1996 at the Department of Dermatology of the School of Medicine of Botucatu. Methods - Descriptive study obtained from specific protocols comprising anamnesis, clinical- dermatological-laboratorial examination, treatment and follow-up of the patients. Results - Paracoccidioidomycosis was diagnosed in 1.04% of the dermatologic outpatients assisted from 1976 to 1996. In 315 cases, 89.8% were male, 61.9% were over forty and 53.7% were rural workers. The complaints were related more to oropharyngolaryngeal (53.6%) or cutaneous (23.8%) lesions or adenopathy (10.2%). Seventy patients had already been treated in other health services. The chronic multifocal clinical from was the most common: 80.6% of the cases, followed by the acute-subacute (juvenile type) 15.5%. The disease was pulmonary in 80.0%, oropharyngolaryngeal in 69.2% and cutaneous in 45.7%. Th treatment: Amphotericin B in 146 patients, Ketoconazole - 88, Itraconazole - 56, Sulfonamide derivatives - 146 and Terbinafine in 3. The lethality index resulting from the disease or its treatment was 2.0%. Conclusions - The high number of cases, showing the regional relevance of the disease and the high percentage of tegumentary complaints and the high number of relapsing are remarkable.