Evaluation of "myrrh extract" against schistosoma mansoni: a histological study

This study investigated the effect of myrrh extract on different developmental stages of Schistosoma mansoni. Sixty albino mice were used and divided into three main groups: GI [control group], Gil [infected group] and Gill [infected-treated group]. The last group was further divided into 3 subgroups where the drug was administered in a dose of 500mg/kg body weight for 5 days starting on the 1[st] day PI for IIIA, on the 21[st] day PI for IIIB and on the 45[th] day PI for IIIC. A morphometric study was performed for the mean number and perimeter of granulomas. In Gil, typical bilharzial granulomas were frequently encountered in the portal tracts with numerous eosinophils, collagen fiber deposition and reticular fiber condensation. Hepatocytes revealed vacuolation, nuclear affection and depletion of glycogen. In GIII, granulomas were less frequently observed with apparent decrease of eosinophils. The maximum effect of the drug was observed in SGs IIIB and IIIC as detected by significant decrease in the mean number and size of granulomas, paucity of eosinophils, decreased fibrosis and reticular fibers and the restoration of the glycogen content in the hepatocytes. The present data proved that myrrh has a valuable schistosomicidal effect against different stages of S. mansoni. This chemotherapeutic effect was more evident when the drug was given to infected mice on the 21[st] as well as on the 45[th] day PI

Descrição do gene do receptor de TNF-α Schistosoma mansoni e efeito do TNF-α humano na expressão gênica do parasita / Description of the TNF-α receptor gene in Schistosoma mansoni and the effect of human TNF-α on the parasite's gene expression

O parasita Schistosoma mansoni é um dos principais causadores da esquistossomose, doença que acomete 200 milhões de indivíduos no mundo. O parasita possui um complexo ciclo de vida composto de seis estágios evolutivos em dois hospedeiros. S. mansoni possui um sofisticado sistema de interação com seus hospedeiros de modo a escapar da resposta imune e interagir com moléculas produzidas por eles. Alguns trabalhos na literatura descreveram o efeito do TNF-α humano sobre o processo de ovoposição do parasita adulto. Nosso trabalho teve por objetivo analisar o perfil de expressão gênica do S. mansoni ao longo de seus estágios de desenvolvimento, avaliar o efeito do TNF-α humano sobre o perfil de expressão gênica do parasita em dois estágios de desenvolvimento e descrever o gene homólogo ao receptor de TNF-α humano em S. mansoni. Para isso, duas plataformas de microarrays distintas foram utilizadas: uma composta por 4000 sondas de cDNA dupla fita produzida pelo nosso grupo de pesquisa e a outra, composta por 44000 sondas de oligonucleotídeos desenhadas pelo nosso grupo e produzida pela empresa Agilent Technologies. Com estas plataformas foi detectada a expressão de 5798 genes em vermes adultos, sendo que 156 genes apresentavam a transcrição nas fitas senso e anti-senso; 6 destes tiveram confirmadas a transcrição nas duas fitas por transcrição reversa fita específica seguida de PCR em Tempo Real. Adicionalmente foram identificados 229 genes diferencialmente expressos entre vermes adultos machos e fêmeas. A análise de expressão gênica entre 5 estágios de desenvolvimento do parasita mostrou dois tipos de conjuntos de dados: (i) 1423 genes diferencialmente expressos entre dois estágios subseqüentes de desenvolvimento e (ii) 342 genes com expressão enriquecida em um estágio exclusivamente. 68 destes são transcritos intrônicos que não possuem potencial codificador de proteinas. Um gene ortólogo ao receptor de TNF-α humano (SmTNFR) foi clonado e...

The parasite Schistosoma mansoni is one of major causative agents of schistosomiasis, a disease which affects 200 million people in the world. The parasite has a complex life cycle with six developmental stages in two hosts. S. mansoni has a sofisticated system of interaction with the hosts, permitting it to escape the immune response and to interact with molecules produced by the hosts. The effect of human TNF-α on adult parasite egg-laying has been described in the literature. The present work intended to analyse the gene expression profile of S. mansoni among its developmental stages, to evaluate the effect of human TNF-α on gene expression profile in two different developmental stages and to describe a homologous gene to human TNF-α receptor in S. mansoni. Two microarrays platfoms were used: one comprised by 4000 cDNA probes and printed by our research group and another, comprised by 44000 oligonucleotide probes designed by our group and printed by Agilent Technologies Company. With these platforms, we detected the expression of 5798 genes in adult worms, of which 156 showed transcription in sense and anti-sense strands; 6 of them had their expression levels confirmed by strand specific Real Time PCR. 229 genes were identified as differentially expressed between male and female adult worms. Gene expression analysis among 5 parasite developmental stages identified two data sets: (i) 1423 differentially expressed genes between two subsequent developmental stages and (ii) 342 expressed genes enriched in one exclusive stage. 68 of them are intronic transcripts with no protein-coding potential. An ortologue to human TNF-α receptor (SmTNFR) was cloned and sequenced. SmTNFR transcritpt has 1967bp and encodes a 599-amino acid protein. Other 9 genes encoding conserved elements of the TNF-α signaling pathway were identified among the public S. mansoni ESTs dataset, thus revealing a complete TNF-α signaling pathway in the parasite...

Study of the morphological characteristics of Schistosoma mansoni in mice, squirrels, and hamsters.

This study attempted to describe mophological characteristics of S. mansoni worms. In the present study, 6 hamsters, 35 squirrels and 141 mice were infected with pooled cercariae of Schistosoma mansoni by intraperitoneal and percutaneous routes. The worm recovery rate was 18.2% (257/1,412) in hamsters (Mesocricetus auratus); 10.1% (3,310/32,792) in squirrels (Callosciurus erythraeus roberti) and 16.2% (4,328/26,720) in mice (Swiss strain). There were no significant differences between the sizes of 332 adults studied from three kinds of experimental animals. However, the worms collected from the hepatic portal system were usually larger than those from the peritoneal cavity because the latter almost always remained in the immature stage. We found male S. mansoni with tandem (17-22%), non-tandem (80-83%) and unusual/irregular arrangement (3-5%) of testes. The number of S. mansoni testes found were from 3 to 15 in mice, 3 to 11 in hamsters and 4 to 15 in squirrels. Mature worms had a tendency to reduce their size with aging. The number of S. mansoni cecal loops were from 1 to 5 in mice and hamsters and 1 to 4 in squirrels. The location of the first cecal loop was usually in the anterior part of body (1/4 in females and 1/3 in males), but there were some exceptions. The number of eggs in the uterus of each female worm, were 0-3 in mice, 0-1 in squirrels and hamsters. The average number was 0.75. The location of the ovary was usually situated in the anterior part of body of the worm in the three kinds of experimental animals. A few mated male and female worms of S. mansoni being free in the peritoneal cavity were found to develop to sexual maturity, because eggs were observed in their uteri. Their size was usually found to be considerably smaller than the worms seen in the hepatic portal system, and they had no hematin in their intestinal ceca. Encapsulated eggs were found from the peritoneal cavities of a few mice following intraperitoneal and percutaneous methods of infection.

Morphological study of adult male worms of schistosoma mansoni Sambon, 1907 by confocal laser scanning microscopy

Aiming to detail data obtained through brightfield microscopy (BM) on reproductive, excretory and digestive system, specimens of Schistosoma mansoni eight weeks old, were recovered from SW mice stained with Langeron's carmine and analysed under a confocal laser scanning microscope CLSM 410 (Carl Weiss). The reproductive system presented a single and locate testis, with intercommunications between the lobes without efferent duct. Supernumerary testicular lobe was amorphus and isolated from the normal ones. Collecting tubules (excretory ducts), followed by the excretory bladder, opening to the external media through the excretory pore, were observed at the posterior extremity of the body. In the digestive tract, a cecal swelling was noted at the junction that originates the single cecum. It was concluded that through confocal laser scanning microscopy, new interpretations of morphological structures of S. mansoni worms could be achieved, modifying adopted and current descriptions. The gonad consists of a single lobed testis, similar to that observed in some trematode species. Moreover, the same specimens can be observed either by BM or CLSM, considering that the latter causes only focal and limited damage in tissue structures.

Schistosoma mansoni Sambon 1907: morphometric differences between adult worms from sympatric rodent and human isolates

A computer software for image (IMAGE PRO PLUS, MEDIA CYBERNETICS) was utilized in male and females adult worms aiming the morphological characterization of Schistosoma mansoni samples isolated from a sylvatic rodent, Nectomys squamipes and humans in Sumidouro, Rio de Janeiro, Brazil and recovered from Mus musculus C3H/He. The following characters for male's testicular lobes were analyzed: number, area, density, larger and shorter diameter, longer and shorter axis and perimeter and extension; for females: area, longer and shorter axis, larger and smaller diameter and perimeter of the eggs and spine; oral and ventral suckers area and distance between them in both sex were determined. By the analysis of variance (one way ANOVA) significant differences (p<0.05) were observed in all studied characters, except for the density of testicular lobes. Significant differences (p<0.05) were detected for all characters in the female worms. Data ratify that sympatric isolates present phenotypic differences and the adult female characters are useful for the proper identification of S. mansoni isolates.

Quetotaxia cercariana de la cepa caraballeda de schistosoma mansoni / Number and pattern of disposition of argentophilic papillae of caraballeda strain of schistosoma mansoni cercaria

Mediante la impregnación con una solución de nitrato de plata al 2 por ciento de un lote de 66 cercarias de schistosoma mansoni, pertenecientes a la cepa de la localidad de Caraballeda, Municipio Vargas, Venezuela, se estudió el número y patrón de disposición de las papilas argirófilas superficiales. En la vista dorsal se determinó un promedio de 5,92 y 5,98 papilas por hemicuerpo y de 11,91 en total, la variabilidad evaluada mediante el coeficiente de variación fue baja de 6,1 por ciento y 3,5 por ciento por hemicuerpo y de 3,8 por ciento en total. En la vista ventral los valores promedios del número de papilas fueron de 5,6 y 5,8 por hemicuerpo y de 11,46 en total; los coeficientes de variación obtenidos resultaron ligeramente superiores a los de la vista ventral, 9,2 por ciento y 8,9 por ciento en los hemicuerpos y de 7,1 por ciento en total

Quetotaxia cercariana de dos cepas venezolanas / Cercarial chaetotaxy of 2 Venezuelan strains of schistosoma mansoni

By means of the silver impregnation of two lots of Schistosoma mansoni cercariae belonging to the strains: JR (32 cercariae) and C5 (45 cercariac), the number and pattem of disposition of the argentophillic papillae were detertnined with the following results: -Average number of total dorsal papillae: 12.1 (JR strain) and 12.0 (C5 strain); the variation coefficients in this surface were less than 4 por ciento (JR strain) and bigger in JR than C5 strain. -Average number of total ventral papillac: 12.15 (JR), 11.97 (C5); maximum value of the variation coeficiente 6.4 por ciento (JR), higher in JR than C5 strain. -When the ventral surface was classified in four quadrants, the average number of papillae by quadrant was: quadrant A: 1. 15 (JR) and 1.06 (C5); B: 1.06 (JR) and 1 (C5); C: 4.97 (JR) and 4.96 (C5); D: 5.03 (JR) and 4.98 (C5). The variation coefficients were higher in the A and B ventral quadrants, reaching maximum values of 31.9 por ciento, and 61.0 por ciento for the posterior quadrants C and D. -When the ventral surface was divided in three equal parts for determining the position of the most variable papillae of this area, the greatest value of the variation coefficients obtained were for the 2nd thirds of the cercariae: 89.8 por ciento and 76.8 por ciento for C5 strain and 43.5 por ciento and 56.8 por ciento for JR strain. In relation to the total lateral papillac, the average numbers were: 17.0 (JR) and 16.6 (C5), with a maximum value of variation coefficient of (8. 1 por ciento (C5). The average total numbers of papillae of the tail were: 25.6 (JR) and 26.1 (C5) for the ventral surface and 20.72 (JR) and 21.33 (C5) for the dorsal papillae. The comparison between the percents of the cercariae of two S. mansoni strains with more than 1 papillae on the anterior ventral quadrants A or B (94 por ciento JR and 34 percent C5), resulted with significant diferentes (P < 0.05) (AU)##

Schistosoma mansoni Sambon, 1907: comparative morphological studies of some brazilian strains

A morfologia de vermes adultos machos de tres cepas de Schistosoma mansoni, mantidas por variacoes em camundongos albinos, foi comparada com uma cepa isolada do hospedeiro natural Nectomys squamipes (Rodentia:Maridae) e mantida, em laboratorio, neste mesmo roedor silvestre. Como caracteres taxonomicos foram analisados o comprimento total, o numero de testiculos, a distancia entre as ventosas e a distancia ocupada pelos testiculos nos especimes. Os vermes recuperados de N. squamipes apresentaram diferencas significativas (p<0,01) em relacao as outras cepas para quaisquer caracteres morfologicos estudados. A cepas mantidas em camundongos apresentaram diferenca estatistica em varios caracteres (p<0,01). Alguns vermes adultos alem da disposicao normal dos testiculos apresentaram tambem uma localizacao atipica destas glandulas sexuais.

Biological and morphological characteristics of Schistosoma mansoni from Ribeira Valley, state of Säo Paulo, Brazil I--Susceptibility of Biomphalaria tenagophila snail to sympatric S. mansoni strain

In the Säo Paulo State, Brazil, where the Biomphalaria tenagophila is the intermediate host, the Ribeira Valley is an important endemic schistosomiasis mansoni area. During last eleven years there has been intense control measures focusing on schistosomiasis. The efforts have been concentrated in the municipalities of Pedro de Toledo and Itariri. We determined the susceptibility of B. tenagophila to sympatric strain of S. mansoni, both recently isolated from Itariri field. In 1988, this strain was isolated and maintained in the experimental model: Swiss mice--sympatric B. tenagophila. The second generation of the worm was evaluated. The snail were divided in the three groups of 60 snails each. One group was exposed to 1 miracidium and other to 10. The third group was the control. The mortality and the shedding of cercariae were checked during 78 days. After that, the positive snails were observed until they ceased to shed cercariae. The exposed molluscs showed mortality rates of 23% and 31% and infection indexes were of 8% and 60% to 1 and 10 miracidia respectively. The mortality was of 22% in the control group. The periods of shedding cercariae in the two groups were 82 and 104 days. We can conclude that B. tenagophila is an effective intermediate host to the sympatric strain of S. mansoni sympatric strain

La queratotaxia cercariana en la diferenciacion de sexos de schistosoma mansoni

El número de papilas argirófilas superficiales y su modelo de disposición en el tegumento de las cercarias (quetotaxia) de Schistosoma mansoni nos permitió diferenciar los sexos a nivel del mencionado estadío larvario, mediante los siguientes critérios: - Mayor homogeneidad en las cercarias machos, en cuanto al número total de papilas ventrales y dorsales a nivel de cuerpo y cola cercarianos (C.V. = 4,1%), que en las cercarias hembras (C. V. = 18,3%) (P < 0,001). - Presencia en el 80% de las cercarias machos de cuatro papilas en los cuadrantes "C" ó "D" )inferior-izquierdo e inferior-derecho, respectivamente) ventrales, mientras que dicho caracter sólo está presente en el 40% de las cercarias hembras (P < 0,001). - Diferencia estadísticamente significativa (P < 0,001) entre el número total promedio de papilas corporales centrales de las cercarias hembras (X = 11,9 ñ 0,2) y el de las cercarias machos (X = 11,1 ñ 0,3). - Diferencia estadísticamente significativa (P < 0,05) para la mayor distancia promedio entre las papilas AIL y AIIL, de cada cercaria, en relación con el sexo (femenino = 25,5 micronm ñ 0,33; masculino = 27,3 micronm ñ 0,26

Levels of lethal antibody during the course of infection with Schistosoma mansoni in rats and mice

Schistosoma mansoni infected hosts produce an IgG that mediates the complement-dependent killing of schistosomula in vitro. In this study, we followed the levels of serum lethal antibody during infection of rats and mice. Rats presented detectable lethal activity early in the course of infection with a peak in the 6-8th week of infection. This activity declined to non-detectable levels within 2 weeks, remaining low up to the 20-26th week. In mice, lethal antibody was not detected before 7-12 weeks of infection, but raised to higher levels, as compared to non-infected animals, up to 20-24 weeks after infection. We correlate lethal antibody and protective immunity suggesting that the antibody-mediated complement-dependent cytotoxicity to schistosomula play a role in the immunity to reinfection.