Mitochondrial activity disruption and local muscle damage induced in mice by Scolopendra polymorpha venom.

BACKGROUND: Scolopendra polymorpha (S. polymorpha) is a predatory centipede whose venom contains a multiplicity of biochemical effectors that can cause muscle damage and cumulative cell destruction in its prey. Despite previous investigations of S. polymorpha and other centipede venoms, there is a lack of information on the morphological and biochemical patterns elicited by their myotoxic effects. To elucidate these processes, this paper presents evidence of skeletal muscle damage, and alterations in key biochemical mediators that appear only after exposure to centipede venom. METHODS: Venom was collected and fractionated using RP-HPLC; mouse extensor digitorum longus (EDL) muscle was exposed to whole venom and venom fractions to evaluate myotoxicity by means of creatine kinase (CK) - a muscle damage marker - activity measurements and histochemical analysis. RESULTS: CK activity was higher in EDL muscle exposed to venom than in unexposed muscle. This increase was observed after 15 min of venom incubation, and remained stable up to 45 min. Venom-exposed EDL muscle showed signs of muscle damage including necrosis, loss of fascicular structure as well as mitochondrial accumulations and ragged red fibers (RRF), suggesting an impairment in the normal mitochondrial arrangement. Nicotinamide adenine dinucleotide (NADH) and cytochrome oxidase (COX) tests also indicate that respiratory complexes might be affected. CONCLUSION: Our results suggest a different biochemical composition of S. polymorpha venom, based on the different effects of four venom fractions on the cells tested, according to statistical evidence. Fractions F6 and F7 caused the most important alterations.

Mitochondrial activity disruption and local muscle damage induced in mice by Scolopendra polymorpha venom

Background:Scolopendra polymorpha (S. polymorpha) is a predatory centipede whose venom contains a multiplicity of biochemical effectors that can cause muscle damage and cumulative cell destruction in its prey. Despite previous investigations of S. polymorpha and other centipede venoms, there is a lack of information on the morphological and biochemical patterns elicited by their myotoxic effects. To elucidate these processes, this paper presents evidence of skeletal muscle damage, and alterations in key biochemical mediators that appear only after exposure to centipede venom.Methods:Venom was collected and fractionated using RP-HPLC; mouse extensor digitorum longus (EDL) muscle was exposed to whole venom and venom fractions to evaluate myotoxicity by means of creatine kinase (CK) - a muscle damage marker - activity measurements and histochemical analysis.Results:CK activity was higher in EDL muscle exposed to venom than in unexposed muscle. This increase was observed after 15 min of venom incubation, and remained stable up to 45 min. Venom-exposed EDL muscle showed signs of muscle damage including necrosis, loss of fascicular structure as well as mitochondrial accumulations and ragged red fibers (RRF), suggesting an impairment in the normal mitochondrial arrangement. Nicotinamide adenine dinucleotide (NADH) and cytochrome oxidase (COX) tests also indicate that respiratory complexes might be affected.Conclusion:Our results suggest a different biochemical composition of S. polymorpha venom, based on the different effects of four venom fractions on the cells tested, according to statistical evidence. Fractions F6 and F7 caused the most important alterations.(AU)

Mitochondrial activity disruption and local muscle damage induced in mice by Scolopendra polymorpha venom

Scolopendra polymorpha (S. polymorpha) is a predatory centipede whose venom contains a multiplicity of biochemical effectors that can cause muscle damage and cumulative cell destruction in its prey. Despite previous investigations of S. polymorpha and other centipede venoms, there is a lack of information on the morphological and biochemical patterns elicited by their myotoxic effects. To elucidate these processes, this paper presents evidence of skeletal muscle damage, and alterations in key biochemical mediators that appear only after exposure to centipede venom. Methods: Venom was collected and fractionated using RP-HPLC; mouse extensor digitorum longus (EDL) muscle was exposed to whole venom and venom fractions to evaluate myotoxicity by means of creatine kinase (CK) - a muscle damage marker - activity measurements and histochemical analysis. Results: CK activity was higher in EDL muscle exposed to venom than in unexposed muscle. This increase was observed after 15 min of venom incubation, and remained stable up to 45 min. Venom-exposed EDL muscle showed signs of muscle damage including necrosis, loss of fascicular structure as well as mitochondrial accumulations and ragged red fibers (RRF), suggesting an impairment in the normal mitochondrial arrangement. Nicotinamide adenine dinucleotide (NADH) and cytochrome oxidase (COX) tests also indicate that respiratory complexes might be affected. Conclusion: Our results suggest a different biochemical composition of S. polymorpha venom, based on the different effects of four venom fractions on the cells tested, according to statistical evidence. Fractions F6 and F7 caused the most important alterations.(AU)

Resin glycosides evoke the Gaba release by sodium- and/or calcium-dependent mechanism.

Ipomoea tyrianthina Lindley (syn. I. orizabensis Pelletan, Lebed. ex Steud., Convolvulaceae) is known as a purgative, but it has been also used in Mexican traditional medicine in the treatment of seizures and pain for their anticonvulsive, hypnotic and sedative properties. Some glycolipids isolated from this plant have shown significant effects on Central Nervous System, modifying inhibitory or excitatory processes. The mechanism for such activity it is not clear; studies with these metabolites have suggested that a pore-forming mechanism is involved in their activity. Therefore, the present work explores a possible not pore-forming mechanism related to the effect of four resin glycosides, Scammonin 1 (S-1), tyrianthin C (T-C), tyrianthin A (T-A) and tyrianthinic acid VI (TA-VI), isolated from Ipomoea tyrianthina root on GABAergic transmission system in cerebral cortex slices of mouse brain in an in vitro model. The results obtained show that all glycolipids tested evoked endogenous GABA release and increased its concentration within the incubation medium compared with controls; T-C demonstrated a dose-dependent effect. Sodium absence and guvacine presence did not affect significantly the activity of S-1 and T-C in contrast to T-A and TA-VI. S-1 and T-C effects were calcium-dependent, where GABA concentrations were considerably reduced. These results suggest that the increase of endogenous γ-aminobutyric acid (GABA) released evoked by these glycolipids is possibly done through a Na+- and/or Ca2+-dependent mechanisms, discarding a pore-forming mechanism.

Neuropharmacological and neuroprotective activities of some metabolites produced by cell suspension culture of Waltheria americana Linn.

Waltheria americana is a plant used in Mexican traditional medicine to treat some nervous system disorders. The aims of the present study were to isolate and determine the neuropharmacological and neurprotective activities of metabolites produced by a cell suspension culture of Waltheria americana. Submerged cultivation of W. americana cells provided biomass. A methanol-soluble extract (WAsc) was obtained from biomass. WAsc was fractionated yielding the chromatographic fractions 4WAsc-H2O and WAsc-CH2Cl2. For the determination of anticonvulsant activity in vivo, seizures were induced in mice by pentylenetetrazol (PTZ). Neuropharmacological activities (release of gamma amino butyric acid (GABA) and neuroprotection) of chromatographic fractions were determined by in vitro histological analysis of brain sections of mice post mortem. Fraction 4WAsc-H2O (containing saccharides) did not produce neuronal damage, neurodegeneration, interstitial tissue edema, astrocytic activation, nor cell death. Pretreatment of animals with 4WAsc-H2O and WAsc-CH2Cl2 from W. americana cell suspensions induced an increase in: GABA release, seizure latency, survival time, neuroprotection, and a decrease in the degree of severity of tonic/tonic-clonic convulsions, preventing PTZ-induced death of up to 100% of animals of study. Bioactive compounds produced in suspension cell culture of W. americana produce neuroprotective and neuropharmacological activities associated with the GABAergic neurotransmission system.

Brazilian version of the Profil der Lebensqualität Chronischkranker: validity and psychometric evidences for climacteric women / Versão brasileira do Profil der Lebensqualität Chronischkranker: validade e evidências psicométricas para mulheres climatéricas

The main objective of this study was to validate and examine the psychometric parameters of Profil der Lebensqualität Chronischkranker (PLC) in climacteric women. We conducted an exploratory research in Health Care and Treatment enrollment 280 participants. The data collection instruments were the PLC and the SF- 36 (Medical Outcomes Study 36 - Item Short - Form Health Survey). The original German version of PLC consists of 40 items that explore the biological and psychosocial items of daily life. The questionnaire was submitted to translation into Portuguese of Brazil, back translation, review by experts and cultural adaptation. For the psychometric study, Cronbach's alpha, factor analysis and the Pearson correlation coefficient were used.In the internal consistency analysis, Cronbach's alpha coefficient ranged from 0.81 a 0.89 in all categories, indicating that the instrument has adequate internal consistency. We could verify the existence of five factors that together explained 55.85% of total variance. For criterion validity, Pearson's correlation was between 0.41 and 0.78. Therefore, the Brazilian version of the PLC is configured in valid, reliable and easy-to-use option for assessment of quality of life in climacteric women.

O objetivo deste estudo foi validar e verificar os parâmetros psicométricos da Escala Profil der Lebensqualität Chronischkranker (PLC) para uma amostra de 280 mulheres climatéricas. Realizou-se uma pesquisa exploratória, cujos instrumentos de coleta foram o PLC e o SF-36 (Medical Outcomes Study 36 - Item Short - Form Health Survey). A versão original em alemão do PLC compõe- se de 40 itens que exploram os itens biológicos e psicossociais da vida diária. Foi realizada a tradução para o português do Brasil, retrotradução, revisão por painel de especialistas e adaptação cultural. Para o estudo psicométrico foram utilizados alfa de Cronbach, análise fatorial e coeficiente de Pearson. O coeficiente alfa de Cronbach variou de 0,81 a 0,89 em todas as categorias, apontando que o instrumento apresenta adequada consistência interna. Quanto à validade de constructo, verificou- se a existência de cinco fatores (estado de ânimo negativo, capacidade física, função social, estado de ânimo positivo e bem- estar social) que juntos explicam 55,85 % da variância total. Para validade de critério, os valores da correlação de Pearson situaram -se entre 0,41 e 0,78. Sendo assim, a versão brasileira do PLC configura-se em opção válida, confiável e de fácil aplicação para avaliação da qualidade de vida em mulheres climatéricas.

Proteomic characterization of the venom and transcriptomic analysis of the venomous gland from the Mexican centipede Scolopendra viridis.

This communication reports the results of proteomic, transcriptomic, biochemical and electrophysiological analysis of the soluble venom and venom glands of the Mexican centipede Scolopendra viridis Say (here thereafter abbreviated S. viridis). Separation of the soluble venom permitted to obtain 54 different fractions, from which a mass finger printing analysis permitted the identification of at least 86 components, where 70% of the molecules have low molecular masses. Two-dimensional electrophoretic separation of this venom revealed the presence of about forty proteins with molecular weights ranging from 17 to 58kDa. The novo sequencing of 149 peptides obtained by LC-MS/MS from the 2D-gels showed the presence of proteins with amino acid sequences similar to several enzymes and venom allergens type 3. Furthermore, a total of 180 sequences were obtained from a cDNA library prepared with two venomous glands. From this, 155 sequences correspond to complete genes containing more than 200 base pairs each. Comparative sequence analyses of these sequences indicated the presence of different types of enzymes and toxin-like genes. Two proteins with molecular weights around 37,000 and 42,000Da were shown to contain hyaluronidase activity. Electrophysiological assays performed with soluble venom show that it decreases mammalian sodium channel currents. BIOLOGICAL SIGNIFICANCE: Animal venoms of Scolopendra species have been scarcely studied, although they have been reported to contain several bioactive compounds, some of which with potential therapeutic interest. The Mexican centipede S. viridis contains a powerful venom, capable of inflicting immediate effects on their preys. This communication is focused on the identification and description of a proteomic and transcriptomic analysis of the protein components of this venom. Several amino acid sequences similar to reported enzymes are the principal components in the S. viridis venom, but also a low number of toxins were identified. This knowledge should contribute to the understanding of the pharmacological effects caused by bites of this centipede species.

Diagnóstico serológico como indicador del control durante la vigilancia participativa de la transmisión de trypanosoma cruzi en Catamarca, Argentina / Serological diagnosis as a control indicator during the participatory monitoring of the transmission of trypanosoma cruzi in Catamarca, Argentina

INTRODUCCION: El control de la transmisión vectorial de Trypanosoma cruzi en la provincia de Catamarca tuvo un comienzo de gran impacto y su sostenimiento se realizó por un estilo de vigilancia de línea vertical, con lo que se logró un estado avanzado de control. En la década de los 90, debido a las acciones realizadas, se alcanzó el estado de interrupción de la transmisión vectorial y/o transfusional de Trypanosoma cruzi. Esta situación permitió que la provincia fuera catalogada como de mediano riesgo.OBJETIVO: Investigar cuál es el indicador apropiado para señalar el riesgo de reiniciar la transmisión de Trypanosoma cruzi durante la vigilancia participativa.METODOS: En San Isidro y Santa Rosa (Departamento Valle Viejo, Provincia de Catamarca), se realizó un estudio descriptivo retrospectivo y, simultáneamente, otro de corte transversal. Los estudios incluyeron análisis serológicos en niños de 0-14 años, vigilancia mediante búsqueda activa del vector por hora/hombre en las viviendas seleccionadas, análisis parasitológico de los triatominos capturados y encuestas a los pobladores. También hubo talleres comunitarios y capacitación de agentes sanitarios.RESULTADOS: Se determinó una seroprevalencia de 0% en San Isidro y de 0,59% en Santa Rosa. Si bien los indicadores entomológicos registraron infestación intradomicilio del 2%, en cambio, la infestación domiciliaria fue del 10% y 14%, respectivamente, acompañada de una caída importante de las acciones de vigilancia por parte del Estado y de la comunidad.CONCLUSIONES: Es necesaria una reinstalación inmediata de la vigilancia participativa activa para mejorar las medidas de prevención por parte de la comunidad y las acciones de control estatal por parte de los efectores locales, provinciales y nacionales. El Estado debe realizar el ataque químico en las viviendas de acuerdo con las técnicas operativas vigentes y debe intensificar las acciones de vigilancia con evaluaciones hora/hombre.

INTRODUCTION: The control of vectorial transmission of Trypanosoma cruzi in the province of Catamarca had at the beginning a great impact and then was supported by a vertical surveillance. In this way, an advanced control was achieved. The actions undertaken in the 90’s led to a state of interruption of vector transmision and/or transfussion of Trypanosoma cruzi. At that time the province was rated as medium risk.OBJECTIVE: To determine the appropiate indicator assessing the risk of transmission of Trypanosoma cruzi being restarted during the surveillance participation.METHODS: A descriptive retrospective study and, simultaneously, a cross-sectional study were conducted in San Isidro and Santa Rosa (Valle Viejo, Province of Catamarca), including serological tests for children aged 0-14 years, monitoring through active search of vector by man/hour method in the selected houses, parasitological study of captured triatomines and surveys to people living there. There were also community workshops and training of health workers.RESULTS: The seroprevalence was 0% in San Isidro and 0.59% in Santa Rosa. While entomological indicators collected indoors recorded 2%, in contrast, house infestation was 10% and 14% respectively, accompanied by a significant drop in the surveillance by the state and community.CONCLUSIONS: It is necessary to immediately re-establish an active participatory monitoring to improve community prevention measures and state surveillance through effectors at local, provincial and national level. The state should make a vector chemical attack at the houses according to current techniques and should intensify surveillance activities with evaluations using the man/hour method.

Diagnóstico serológico como indicador del control durante la vigilancia participativa de la transmisión de trypanosoma cruzi en Catamarca, Argentina / Serological diagnosis as a control indicator during the participatory monitoring of the transmission of trypanosoma cruzi in Catamarca, Argentina

INTRODUCCION: El control de la transmisión vectorial de Trypanosoma cruzi en la provincia de Catamarca tuvo un comienzo de gran impacto y su sostenimiento se realizó por un estilo de vigilancia de línea vertical, con lo que se logró un estado avanzado de control. En la década de los 90, debido a las acciones realizadas, se alcanzó el estado de interrupción de la transmisión vectorial y/o transfusional de Trypanosoma cruzi. Esta situación permitió que la provincia fuera catalogada como de mediano riesgo.OBJETIVO: Investigar cuál es el indicador apropiado para señalar el riesgo de reiniciar la transmisión de Trypanosoma cruzi durante la vigilancia participativa.METODOS: En San Isidro y Santa Rosa (Departamento Valle Viejo, Provincia de Catamarca), se realizó un estudio descriptivo retrospectivo y, simultáneamente, otro de corte transversal. Los estudios incluyeron análisis serológicos en niños de 0-14 años, vigilancia mediante búsqueda activa del vector por hora/hombre en las viviendas seleccionadas, análisis parasitológico de los triatominos capturados y encuestas a los pobladores. También hubo talleres comunitarios y capacitación de agentes sanitarios.RESULTADOS: Se determinó una seroprevalencia de 0% en San Isidro y de 0,59% en Santa Rosa. Si bien los indicadores entomológicos registraron infestación intradomicilio del 2%, en cambio, la infestación domiciliaria fue del 10% y 14%, respectivamente, acompañada de una caída importante de las acciones de vigilancia por parte del Estado y de la comunidad.CONCLUSIONES: Es necesaria una reinstalación inmediata de la vigilancia participativa activa para mejorar las medidas de prevención por parte de la comunidad y las acciones de control estatal por parte de los efectores locales, provinciales y nacionales. El Estado debe realizar el ataque químico en las viviendas de acuerdo con las técnicas operativas vigentes y debe intensificar las acciones de vigilancia con evaluaciones hora/hombre.

INTRODUCTION: The control of vectorial transmission of Trypanosoma cruzi in the province of Catamarca had at the beginning a great impact and then was supported by a vertical surveillance. In this way, an advanced control was achieved. The actions undertaken in the 90s led to a state of interruption of vector transmision and/or transfussion of Trypanosoma cruzi. At that time the province was rated as medium risk.OBJECTIVE: To determine the appropiate indicator assessing the risk of transmission of Trypanosoma cruzi being restarted during the surveillance participation.METHODS: A descriptive retrospective study and, simultaneously, a cross-sectional study were conducted in San Isidro and Santa Rosa (Valle Viejo, Province of Catamarca), including serological tests for children aged 0-14 years, monitoring through active search of vector by man/hour method in the selected houses, parasitological study of captured triatomines and surveys to people living there. There were also community workshops and training of health workers.RESULTS: The seroprevalence was 0% in San Isidro and 0.59% in Santa Rosa. While entomological indicators collected indoors recorded 2%, in contrast, house infestation was 10% and 14% respectively, accompanied by a significant drop in the surveillance by the state and community.CONCLUSIONS: It is necessary to immediately re-establish an active participatory monitoring to improve community prevention measures and state surveillance through effectors at local, provincial and national level. The state should make a vector chemical attack at the houses according to current techniques and should intensify surveillance activities with evaluations using the man/hour method.

Sedative, vasorelaxant, and cytotoxic effects of convolvulin from Ipomoea tyrianthina.

AIM OF THE STUDY: Ipomoea tyrianthina has been used in Mexican traditional medicine as a mild purgative, for the treatment of nervous disorders, and against tumors. In this study, the effect of convolvulin (an ether-insoluble resin glycoside) from the root of Ipomoea tyrianthina on: Central Nervous System; as spasmolytic and vasodilator; cytotoxic against cancer cell lines is evaluated. MATERIALS AND METHODS: Convolvulin isolated from the root of Ipomoea tyrianthina (IT-EM) was tested on pentylentetrazole induced seizures, pentobarbital-induced hypnosis, release of GABA and glutamic acid, isolated rat aorta and ileum rings, and against Caco-2 and KB cell lines. RESULTS: IT-EM increased the hypnotic effect induced by pentobarbital and the release of GABA in brain cortex of mice, but did not protect mice against pentylenetetrazole-induced convulsions. IT-EM produced a significant vasodilator effect in concentration- and endothelium-dependent manners on isolated rat aorta, but did not inhibit significantly contractions on rat ileum, colon, and jejune rings. IT-EM showed cytotoxic activity against nasopharyngeal carcinoma KB cell line. CONCLUSIONS: Convolvulin (IT-EM) from Ipomoea tyrianthina has sedative effect, vasorelaxant effect in concentration- and endothelium-dependent manners, and cytotoxic activity against nasopharyngeal carcinoma KB cell line.

Synthesis of benzologues of Nitazoxanide and Tizoxanide: a comparative study of their in vitro broad-spectrum antiprotozoal activity.

We have synthesized two new benzologues of Nitazoxanide (NIT) and Tizoxanide (TIZ), using a short synthetic route. Both compounds were tested in vitro against six protozoa (Giardia intestinalis, Trichomonas vaginalis, Entamoeba histolytica, Plasmodium berghei, Leishmania mexicana and Trypanosoma cruzi). Compound 1 (benzologue of NIT) showed broad antiprotozoal effect against all parasites tested, showing IC(50)'s<5 µM. This compound was five-times more active than NIT, and 18-times more potent than metronidazole against G. intestinalis. It was 10-times more active than pentamidine against L. mexicana, and it was sevenfold more potent than benznidazole versus T. cruzi. This compound could be considered as a new broad spectrum antiprotozoal agent.

Isolation of jacaranone, a sedative constituent extracted from the flowers of the Mexican tree Ternstroemia pringlei.

ETHNOPHARMACOLOGICAL RELEVANCE: Ternstroemia pringlei represents one of the most widely employed and commercially exploited medicinal plant in Mexico, used popularly as a tranquilizer and for the treatment of insomnia. AIM OF THE STUDY: To investigate the sedative constituents of the plant through a bio-guided fractionation of extracts derived from calyx and fruits. MATERIALS AND METHODS: Crude extracts with different polarities (CHCl(3), AcOEt, MeOH, aqueous) were prepared and subjected to chromatographic fractionation, leading to the isolation of the sedative compound (1) from the MeOH crude extract. The identity of 1 was unequivocally established by means of 1D and 2D NMR spectroscopic analysis. The sleeping time induced by sodium pentobarbital and the elevated plus-maze models were performed on mice to determine the sedative and anxiolytic activities, respectively. Bioactivity was also investigated though in vitro GABA release experiments using mice brain slices. RESULTS: The sedative compound was established as jacaranone (1), and its effect was clearly demonstrated through a dose-dependent response analysis (ED(50) = 25 mg/kg mouse weight). When tested in the elevated plus-maze model, none of the extracts from Ternstroemia pringlei displayed anxiolytic activity. GABA release experiments showed that the MeOH and aqueous crude extracts released this neurotransmitter at a ratio of 217 and 179 pmol/g protein, respectively, evidencing the presence of other bioactive constituents in the extracts apart of 1, whose activity was absent in this model. CONCLUSIONS: Although 1 has been isolated and identified in a number of plant species, this is the first time that its sedative effect has been demonstrated. No previous record exists of other sedative compounds having been isolated from Ternstroemia pringlei.

Glycolipid ester-type heterodimers from Ipomoea tyrianthina and their pharmacological activity.

Tyrianthins A (1) and B (2), two new partially acylated glycolipid ester-type heterodimers were isolated from Ipomoea tyrianthina. Scammonic acid A was determined as the glycosidic acid in both monomeric units. Tyrianthin A (1) (IC(50) 0.24+/-0.09 microM and E(max) 81.80+/-0.98%), and tyrianthin B (2) (IC(50) 0.14+/-0.08 microM and E(max) 87.68+/-0.72%) showed significant in vitro relaxant effect on aortic rat rings, in endothelium- and concentration-dependent manners. Also, these compounds were able to increase the release of GABA and glutamic acid in brain cortex, and displayed weak antimycobacterial activity.

Venom from the centipede Scolopendra viridis Say: purification, gene cloning and phylogenetic analysis of a phospholipase A2.

Venom components from the centipede Scolopendra viridis Say were studied, using both the soluble venom and a cDNA library prepared from mRNA of the venomous glands. Separation of the soluble venom by high performance liquid chromatography (HPLC) permitted to obtain at least 54 different fractions. The fraction eluting at 46.24 min showed phospholipase activity. The enzyme was purified to homogeneity and the first 25 amino acid residues were identified by Edman degradation. From the cDNA library several genes were cloned, one of which codes for a protein with identical amino acid sequence as the one experimentally determined. The cloned gene codes for a signal peptide of 28 amino acids and a mature peptide of 119 residues. The molecular weight of the enzyme was estimated by mass spectrometry and shown to be 13,752 Da, which matches exactly with the molecular mass expected from the deduced amino acid sequence of the gene. Phylogenetic analysis of this sequence, in comparison with other known from venomous animals, showed that it is more similar to snake phospholipases than to insect or arachnid sequences, suggesting that it has been submitted to convergent evolution. To the best of our knowledge this is the first time that a phospholipase from this species of animal is fully characterized. We have named it Scol/Pla.

Design, synthesis and in vitro antiprotozoal activity of benzimidazole-pentamidine hybrids.

A series of ten novel hybrids from benzimidazole and pentamidine were prepared using a short synthetic route. Each compound was tested in vitro against the protozoa Trichomonas vaginalis, Giardia lamblia, Entamoeba histolytica, Leishmania mexicana, and Plasmodium berghei, in comparison with pentamidine and metronidazole. Some analogues showed high bioactivity in the low micromolar range (IC(50)<1 microM) against the first four protozoa, which make them significantly more potent than either standard. 1,5-bis[4-(5-methoxy-1H-benzimidazole-2-yl)phenoxy]pentane (2) was 3- and 9-fold more potent againstG. lamblia than metronidazole and pentamidine, respectively. This compound was 23-, 108-, and 13-fold more active than pentamidine against T. vaginalis, E. histolytica and L. mexicana, respectively. Studying further structure-activity relationships through the use of bioisosteric substitution in these hybrids should provide new leads against protozoal diseases.

Antigen-induced regulatory T cells in HBV chronically infected patients.

T cell response against HBV is vigorous in patients with acute hepatitis who clear the virus, whereas it is weak and narrowly focused in patients with chronic disease. We report that following incubation with HBcAg, a population of CD4+FoxP3+ cells expressing phenotypic markers of both natural and induced Tregs, can be antigen-induced from peripheral mononuclear cells. Conversely, naive and naturally immune subjects did not increase CD4+FoxP3+ Tregs following stimulation with HBcAg, supporting the idea that natural Tregs are able to respond specifically to HBV antigen. Furthermore, increased frequencies of antigen-induced CD4+FoxP3+IL-10+ Tregs correlated with viral load, suggesting that antigen-induced Tregs could contribute to an inadequate response against the virus, leading to chronic infection and support the view that specific natural Tregs may be implicated in host immune tolerance during HBV infection.

Analgesic activity of affinin, an alkamide from Heliopsis longipes (Compositae).

Heliopsis longipes (Compositae) is a Mexican plant used as analgesic in pain toothache. A solution of 10mug/ml of dichloromethane extract from this plant showed analgesic activity determined by means of GABA release in mice brain slices. Through a bioassay-directed separation, fractions G-1, G-2, G-4 and G-6 at the same concentration were active. Affinin was the unique and common active compound, and evoke the GABA release 0.5min after administration at 1x10(-4)M concentration. Inactive compound were undeca-2E-en-8,10-dyinoic acid isobutylamide, hinokinin, 2'-hydroxyhinokinin, 3beta-sn-glyceroyl-(1''-palmitoxy)urs-12-ene, 13(18)-ursen-3beta-ol, 13(18)-ursen-3beta-acetate, beta-sitosterol and stigmasterol. The analgesic activity of Heliopsis longipes could be associated to affinin.

Antimalarial 4-phenylcoumarins from the stem bark of Hintonia latiflora.

The EtOAc extract of the stem bark of Hintonia latiflora showed the suppression of total parasitemia and the chemosuppression of schizont numbers, when tested in vivo against Plasmodium berghei infection in mice. Bioassay-directed fractionation of the EtOAc extract, using the in vitro 16 h and the in vivo 4-day suppression tests on P. berghei schizont numbers, led to the isolation of the new compound 5-O-beta-D-glucopyranosyl-7,4'-dimethoxy-3'-hydroxy-4-phenylcoumarin (1), along with the known 5-O-beta-D-glucopyranosyl-7-methoxy-3',4'-dihydroxy-4-phenylcoumarin (2). The structure of compound 1 was established on the basis of spectroscopic data interpretation. Compounds 1 and 2 suppressed the development of P. berghei schizonts in vitro with IC50 values of 24.7 and 25.9 microM, respectively. Compound 2 suppressed the development of schizonts at the dose of 40 mg/kg by 70.8% in the in vivo assay.

A toxic fraction from scolopendra venom increases the basal release of neurotransmitters in the ventral ganglia of crustaceans.

A toxic fraction from centipede (Scolopendra sp.) venom was tested in neurotransmitter release experiments. The venom was fractionated by DEAE-cellulose with a linear gradient from 20 mM to 1.0 M of ammonium acetate pH 4.7. Lethality tests were performed by injections into the third abdominal dorsolateral segment of sweet water crayfishes of the species Cambarellus cambarellus. Only fraction V (TF) was toxic. Analysis by SDS-PAGE showed that this fraction contains at least seven proteins. It induces an increase of basal gamma-amino butyric acid (GABA) and glutamate release from ventral abdominal ganglia of C. cambarellus. Assays conducted with this fraction in the presence of several drugs that affect ion channel function suggested that TF modifies membrane permeability by increasing basal release of neurotransmitters was very likely through sodium channels.

Linfomas no Hodgkin en el niño: aspectos histopatológicos / Non-Hodgkin lymphomas in children: histopathology

Se realiza una puesta al día en aspectos histopatológicos de los linfomas no-Hodgkin en pediatría. El interés de esta comunicación es poner a disposición del pediatra los aspectos prácticos de estas entidades desde el punto de vista de la anatomía patológica con especial referencia al empleo de la inmunotipificación