The treatment with selenium increases placental parasitismin pregnant Wistar rats infected with the Y strain of Trypanosoma cruzi.

Selenium (Se) is an essential micronutrient in the diet of mammals and has an important role in the immune function. Selenium is a key element in selenoproteins involved in the in the maintenance of the antioxidant defense. Diet with selenium is beneficial for the treatment of diseases correlated with high levels of oxidative stress, also observed in the Chagas disease. Chagas disease is a neglected disease caused by the protozoan Trypanosoma cruzi and several research groups are focused on the illness treatment. Immunomodulation of the infection using microelements is an important tool to avoid deleterious effects of the Chagas disease. Therefore, our objective was to evaluate the effects of selenium supplementation on pregnant Wistar rats infected with T. cruzi. Selenium treatment stimulated the weight and length of fetuses and placentas allied to the decrease of blood parasitemia. However, selenium demonstrated a low influence on T cells, diminishing the B cell population (CD45RA+). Moreover, the production of pro-inflammatory cytokines was downregulated under selenium administration. Low pro-inflammatory cytokines levels probably are related to the increase in the number of amastigote nests in infected and treated animals. Thus, selenium supplementation during pregnancy could impair the local placental immune response. Further studies are necessary to assess the interaction between selenium and the acute Chagas' disease during pregnancy, which will base future supplementation strategies.

Does L-arginine availability during the early pregnancy alters the immune response of Trypanosoma cruzi infected and pregnant Wistar rats?

Chagas disease induces a strong immune response and L-arginine is an essential amino acid which plays an important role in homeostasis of the immune system. The aims of this study were to evaluate parasitemia, corticosterone levels, production of nitric oxide (NO), fetal morphological measurements, and histology of heart and placenta. Twenty pregnant Wistar rats (180-220 g) were grouped in: pregnant control (PC), pregnant control and L-arginine supplied (PCA), pregnant infected (PI), pregnant infected and L-arginine supplied (PIA). Females were infected with 1×10(5) trypomastigotes of the Y strain (3rd day of pregnancy). Animals were supplied with 21 mg of L-arginine/kg/day during 14 days. PIA showed significant decreased levels of corticosterone and parasitemia. For control groups, any alteration in NO production was found with L-arginine supplementation; for PIA, enhanced nitrite concentrations were observed as compared to PI. Weights and lengths of fetuses were higher in L-arginine treated and infected pregnant rats as compared to untreated ones. Placental weight from the PIA group was significantly increased when compared to PI. In L-arginine treated animals, cardiac tissue showed reduced amastigote burdens. PIA and PI displayed similar placental parasitism. Based on these results, L-arginine supplementation may be potentially useful for the protection against Trypanosoma cruzi during pregnancy.

Effects of zinc during lactation on the junctional epithelium and inserted gum in rats / Efectos del zinc durante la lactancia sobre el epitelio de unión y la encía insertada en ratas

The purpose of this study was to evaluate the effects of zinc, during lactation, on the junctional epithelium and inserted gum of the first upper molar of rats. The study used one-day old male rats, divided into two groups: those whose mother had been treated with 300 mg zinc chloride (ZnCl2) in the drinker water (treated group), and those whose mothers did not receive ZnCl2 (control group). After 21 days, the rat pups were sacrificed. Using karyometrical techniques, the greater (D) and smaller (d) nuclear diameters of the different layers of the junctional and inserted gum epithelia were determined, and the mean geometric diameter, D/d ratio, perimeter, area, volume, volume/area ratio, eccentricity, shape coefficient, and the contour index were estimated. The 100-point Merz grid was used with the purpose of evaluating the citoplasmatic and celular volume, the nucleus/citoplasm relationship, number density, outer surface/basal layer ratio, the thickness of epithelial layers, and the surface density. The results were submitted to statistical analysis using the Wilcoxon-Mann-Whitney test. The nuclei of the studied structures were significantly smaller, and the stereological results demonstrated that there were smaller cells, hence meaning a greater number of cells per mm3 of tissue, in the treated group. Zinc caused changes on the studied epitheliums, according to morphometric and stereological evaluations.

El objetivo de este estudio fue evaluar los efectos del zinc durante la lactancia, sobre el epitelio de unión y la encía insertada del primer molar superior de ratas. Fueron utilizadas ratas macho de un día de edad, divididas en dos grupos: aquellas cuyas madres habían sido tratadas con 300 mg de cloruro de zinc (ZnCl2) con agua del bebedero (grupo tratado) y aquellas cuyas madres no recibieron ZnCl2 (grupo control). Las crías fueron sacrificadas después de 21 días. Utilizando técnicas cariométricas fueron medidos los diámetros mayor (D) y menor (d) de los núcleos de las células de los diferentes estratos del epitelio de unión y de la encía insertada, estimándose el diámetro geométrico medio, la relación D/d, perímetro, área, volumen, relación volumen/área, excentricidad, coeficiente de forma e índice de contorno. Fue usada la rejilla de Merz, de 100 puntos, con la finalidad de evaluar el volumen celular y citoplasmático, la relación núcleo/citoplasma, densidad numérica, relación superficie externa/superficie basal, espesor de las capas epiteliales y densidad de superficie. Los resultados fueron sometidos a análisis estadístico mediante el test de Wilcoxon-Mann-Whitney. En el grupo tratado los núcleos celulares de las estructuras estudiadas fueron significativamente menores y los resultados estereológicos demostraron que las células eran menores, por lo tanto, con mayor número por mm3 de tejido. De acuerdo a los resultados morfométricos y estereológicos, el zinc provocó cambios en los epitelios estudiados.

Zinc and pregnancy: Marked changes on the immune response following zinc therapy for pregnant females challenged with Trypanosoma cruzi.

BACKGROUND & AIMS: The occurrence of infectious disease processes during pregnancy has significant effects on maternal health and can lead to adverse pregnancy outcomes. The aim of the present study was to examine the potential role of zinc treatment during Trypanosoma cruzi infection in pregnant animals. METHODS: Female Wistar rats weighing 180-200 g were used in all experiments. Production of nitric oxide, peritoneal macrophages counts, and concentrations of IFN-γ and TNF-α were measured, and the potential protective effects of zinc on fetal development were assessed at 14-day post-infection. RESULTS: Nitric oxide concentrations were higher in pregnant zinc-treated animals than in their untreated counterparts, despite similar levels of the macrophages, IFN-γ and TNF-α. Zinc therapy was associated with a significant reduction in parasitemia and cardiac parasite burden. Higher placental and birth weights were observed in animals given prenatal zinc supplementation compared to untreated animals. CONCLUSIONS: These data confirm the critical importance of adequate zinc intake during the peri-conceptional period and indicate that zinc has an effective role in preventing adverse outcomes of pregnancy and reducing the risk of common infections such as Chagas' disease.

Alteraciones histopatológicas de placentas de ratones infectadas con diferentes cepas de Trypanosoma cruzi / Histopathological alterations of placentas from mice infected by different Trypanosoma cruzi strains

El objetivo del presente estudio fue evaluar las alteraciones histopatológicas de las placentas provocadas por la infección materna durante la preñez con diferentes cepas de Trypanosoma cruzi. Ratones preñadas, de 60 días de edad, fueron inoculadas por la via intraperitoneal (i.p.) con 2 x 105 tripomastigotes sanguíneos de las cepas colombiana, Y, Bolivia o RC del T. cruzi. Los resultados mostraron que las cepas Bolivia y RC presentan mayor histotropismo por las células placentarias del ratón que las cepas colombiana e Y. El proceso inflamatorio afectó la decidua basal en todos los grupos de ratones infectados, mientras que la cepa colombiana causó intensa degeneración de la decidua basal, con células inflamatorias escasas o ausentes. Las placentas de todos los grupos infectados presentaron áreas de edema, degeneración, necrosis y calcificación, principalmente en la decidua basal. En los animales inoculados con la cepa RC del T. cruzi también fue afectado el trofoblasto de la zona esponjosa. El parasitismo más intenso fue observado en los animales infectados con las cepas Bolivia y RC, envolviendo todas las zonas placentarias, incluso las células trofoblásticas gigantes y el trofoblasto esponjoso. Los resultados permiten concluir que las placentas sufren procesos patológicos diferentes, característicos para cada cepa del T. cruzi.

The objective of the present study was to evaluate the histopathological alterations of the placenta provoked by maternal infection during pregnancy by different Trypanosoma cruzi strains. Pregnant mice, 60 day-old, were i.p. inoculated with 2 x 105 bloodstream trypomastigotes of colombian, Y, Bolivia or RC strains of T. cruzi. The results demonstrated that the Bolivia and RC strains showed higher histotropism for the mouse placental cells than the colombian or Y strains. The inflammatory process in all the infected groups involved the basal decidua, but the colombian strain caused intense decidual degeneration, with rare or absent inflammatory cells. Placentas from all the infected groups displayed aéreas of edema, degeneration, necrosis and calcification, mainly in the basal decidua, but the group infected by the RC strain showed also involvement of the spongiotrophoblast. The highest parasitism was observed with the Bolivia and RC strains, involving all the placenta zones, including the trophoblast giant cells and the spongiotrophoblast. The results show that placentas undergo differentiated pathological processes, characteristic for each strain.

Efectos del cloruro de cobalto sobre el epitelio de unión y epitelio reducido del esmalte del primer molar superior de rata / Effects of cobalt chloride in junctional epithelium and reduced enamel epithelium of the rat maxillary first molar

El cobalto es uno de los principales componentes de las aleaciones metálicas fundidas, usadas frecuentemente en odontología. El metal es el constituyente de 45 a 70 por ciento de los trabajos protéticos. En virtud de la existencia de evidencias que elementos metálicos pueden causar toxicidad sistémica y local, este trabajo tuvo como objetivo evaluar los efectos del cobalto sobre el epitelio de unión y el epitelio del esmalte del primer molar superior de rata, durante la lactancia. Con esa finalidad fueron usadas ratas con 1 día de vida postnatal, cuyas madres recibieron 300 mg de cloruro de cobalto por litro de agua destilada en el bebedero, durante a la lactancia. Al cabo de 21 días, las crías fueron sacrificadas con sobredosis anestésica. Las cabezas fueron separadas, fijadas en "alfac", descalcificadas e incluidas en parafina. Fueron utilizados cortes frontales seriados teñidos con hematoxilina y eosina. Fueron estimados los siguientes parámetros nucleares: diámetros mayor, menor y geométrico medio, relación entre diámetros, perímetro, área, volumen, relación entre volumen y área, excentricidad, coeficiente de forma e índice de contorno. Mediante métodos estereológicos fueron evaluados: relación núcleo/citoplasma, volumen celular, densidad numérica celular, relación superficie externa/camada basal, espesor de las camadas epiteliales y densidad de superficie. Todos los datos obtenidos fueron sometidos a análisis estadístico mediante la prueba no-paramétrica de Wilcoxon-Mann-Whitney. Los núcleos de los tejidos estudiados mostraron valores menores para diámetros, perímetro, área, volumen y relación volumen/área. Estereológicamente, fue posible observar en el epitelio de unión y en el epitelio reducido del esmalte, células menores con citoplasma más escaso, lo que se refleja en mayor número de células por mm3 de tejido. En este estudio, el cobalto ocasionó un cuadro de atrofia epitelial, sugiriendo una acción directa sobre los epitelios de unión y del esmalte.

Cobalt is one of the main components of cast metal alloys broadly used in dentistry. It is the constituent of 45 to 70 percent of numerous prosthetic works. There are evidences that metal elements cause systemic and local toxicity. The purpose of the present study was to evaluate the effects of cobalt on the junctional epithelium and reduced enamel epithelium of the first superior molar in rats, during lactation. To do this, 1-day old rats were used, whose mothers received 300mg of cobalt chloride per liter of distilled water in the drinker, during lactation. After 21 days, the rat pups were killed with an anesthetic overdose. The heads were separated, fixed in "alfac", decalcified and embedded in paraffin. Frontal sections stained with hematoxylin and eosin were employed. Karyometric methods allowed to estimate the following parameters: biggest, smallest and mean diameters, D/d ratio, perimeter, area, volume, volume/area ratio, eccentricity, form coefficient and contour index. Stereologic methods allow to evaluate: cytoplasm/nucleus ratio, cell and cytoplasm volume, cell number density, external surface/basal membrane ratio, thickness of the epithelial layers and surface density. All the collected data were subjected to statistic analysis by the non-parametric Wilcoxon-Mann-Whitney test. The nuclei of the studied tissues showed smaller values after karyometry for: diameters; perimeter, area, volume and volume/area ratio. Stereologically, it was observed, in the junctional epithelium and in the reduced enamel epithelium, smaller cells with scarce cytoplasm, reflected in the greater number of cells per mm3 of tissue. In this study, cobalt caused epithelial atrophy, indicating a direct action on the junctional and enamel epithelium.

Efectos del cadmio sobre las glándulas salivales de rata: durante la lactancia / Effects of cadmium on the rat salivary glands: during lactation

El cadmio (Cd), presente en el aire, agua potable y alimentos, tiene potencial para afectar la salud humana, principalmente en las regiones altamente industrializadas. El Cd además de afectar la función placentaria, puede atravesar la barrera placentaria y perjudicar directamente el desarrollo fetal. En virtud de que el organismo es particularmente susceptible a la exposición al Cd durante el período perinatal, y que ese metal puede ser excretado en la leche, el objetivo del presente trabajo fue estudiar los efectos de la exposición continua a agua potable conteniendo bajos niveles de Cd durante la lactancia sobre las glándulas salivales de la rata. Ratas hembra recibieron agua potable conteniendo 300mg/l de CdCl2 ad libitum durante toda la lactancia. Animales control recibieron un volumen similar de agua potable sin Cd. Las ratas lactantes (21 días de edad) fueron sacrificadas con una dosis letal de anestésico. Las glándulas salivales fueron separadas, fijadas en "alfac" por 24 h, y cortadas seriadamente. Cortes de 6 µm de espesor fueron teñidos con hematoxilina y eosina. Fueron estimados los parámetros nucleares, los volúmenes citoplasmático y celular, la relación núcleo/citoplasma, densidad numérica, densidad superficial, diámetros y espesor de las paredes de las estructuras glandulares. El peso medio corporal fue 34,86 g para la rata control y 18,56 g para la tratada. Histológicamente, los adenómeros glandulares fueron significativamente menores y los conductos glandulares fueron similares en ambos grupos. La estroma fue más abundante en los animales tratados. En conclusión, las glándulas salivales (submandibular, parótida y sublingual) mostraron retardo del crecimiento en los animales intoxicados por Cd.

Cadmium (Cd) in air, drinking water and food has the potential to affect the health of people, mainly those who live in highly industrialized regions. Cd affects placental function, can cross the placental barrier and directly modify fetal development. Once the organism is particularly susceptible to the exposition to the Cd during the perinatal period, and that this metal can be excreted in the milk, the aim of the present work was to study the effects of the constant exposition to drinkable water containing low levels of Cd during the lactation, on the salivary glands of the rat. Female rats received ad libitum drinking water containing 300mg/l of CdCl2 throughout the whole lactation. Control animals received a similar volume of water without Cd. Lactant rats, (21 day old) were killed by lethal dose of anesthetic. The salivary glands were separated, fixed in "alfac" solution for 24 h, and serially sectioned. The 6mm thick sections were stained with hematoxylin and eosin. Nuclear glandular parameters were estimated, as well as cytoplasm and cell volume, nucleus/cytoplasm ratio, number and surface density, diameters and cell thickness. Mean body weight was 34.86 g for the control group and 18,56 g for the Cd-treated group. Histologically, the glandular acini were significantly smaller, the gland ducts were similar in both groups studied. The connective tissue was more abundant. In conclusion, the salivary glands (submandibular, parotid and sublingual) showed retarded growth after Cd intoxication.

Estudio cariométrico de placentas de ratones con infección aguda por diferentes cepas de Trypanosoma cruzi / Karyometric study of placentas from mice with acute infection by different strains of Trypanosoma cruzi

El objetivo de este trabajo fue evaluar cariometricamente las alteraciones causadas por diferentes cepas de T. cruzi en la placenta del ratón. Ratones hembras de 60 días, grávidas, fueron inoculadas, intraperitonealmente, con 2 x 10(5) tripomastigotes sanguíneos de las cepas colombiana, Y, Solivia o RC del T. cruzi. Fueron observadas claras diferencias en las alteraciones cariométricas de las células trofoblásticas gigantes y de las células trofoblásticas de la zona esponjosa. Los resultados demostraron que las cepas colombiana y RC causan alteraciones tanto en las células trofoblásticas gigantes como en las células del trofoblasto esponjoso, mientras que las cepas Y y Bolivia provocan alteraciones solamente en las células trofoblásticas gigantes. Es posible concluir que cada cepa posee características propias y que, a pesar del tipo similar de transmisión, presenta matices diferenciales en el proceso de la patogénesis placentaria.

The objective of this work was to evaluate karyometrically the alterations caused by different strains of Trypanosoma cruzi in the mouse placenta. Pregnant mice, 60-day old, were intraperitoneally inoculated with 2 x 10(5) bloodstream trypomastigotes of the Colombian, Y, Bolivia or RC strain of T cruzi. There were observed clear differences in the karyometric alterations of the trophoblast giant cells and in the spongiotrophoblast cells. The results demonstrate that the Colombian and RC strains cause alterations both in the trophoblast giant cells and in the spongiotrophoblast cells, whereas the Y and Bolivia strains provoke alterations only in the trophoblast giant cells. It is possible concluding that each strain has its own characteristics and that, in spite of the similar type of transmission, it show differential nuances in the placental pathogenic process.

Histometría de la glándula sublingual de ratones (Mus musculus) machos y hembras infectados con la cepa RAL del parásito de Chagas, Trypanosoma cruzi

Histometry of the sublingual gland in male and female mice (Mus musculus) infected with the RAL strain of the Chagas parasite, Trypanosoma cruzi. The aim of this work was to analyze histologically and histometrically the sublingual gland of mice infected with the RAL strain of T. cruzi, according to the sex. Swiss mice (Mus musculus) were inoculated with 2x104 blood trypomastigotes of the RAL strain of T. cruzi. in the peak of the parasitemia (12th day) the mice were sacrificed, and the sublingual glands were fixed in ALFAC. HE-stained histological sections were evaluated histometrically. The parasitemia was higher in females. Histopatologically, acini of the infected animals were smaller, with scanty production of secretion, and smaller striated ducts. The nuclei of the demilunes were smaller and showed amastigote nests in the cytoplasm. Karyometrically, nuclei of the acini, demilunes and striated ducts were smaller in the infected mice. Stereologically, it was observed that relative volumes of acini and ducts were smaller and, inversely, relative volumen were greater for the conjunctive tissue in the infected males. The surface densities of acini and ducts were bigger and the diameter and thickness of the wall were smaller in this group. On the other hand, relative volume of acini was smaller and those of the ducts and conjunctive tissue were bigger in the infected females. The diameter and thickness of the wall of acini were smaller, and those of the striated ducts were bigger in this group. The RAL strain of T. cruzi caused general atrophy in the sublingual gland, with numerous nests of parasites in the glandular parenchyma. Rev. Biol. Trop. 56 (2): 459-471. Epub 2008 June 30.

Analizamos morfológica e histométricamente la glándula sublingual de ratones infectados con la cepa RAL del Trypanosoma cruzi, en machos y hembras. Usamos ratones albinos (Mus musculus), variedad Swiss, inoculados con 2x104 tripomastigotes sanguíneos de la cepa RAL del T. cruzi.. Sacrificamos los animales en el pico de la parasitemia (12º día) y fijamos las glándulas sublinguales en ALFAC. Los cortes histológicos teñidos con HE fueron evaluados histométricamente (cariometría y estereología). La parasitemia fue más elevada en las hembras. Histopatológicamente, los "ácinos" (acini) de los animales infectados eran menores, con escasa secreción, y conductos estriados menores. Los núcleos de las "medialunas" eran menores y había nidos de amastigotes en el citoplasma. Cariométricamente, los núcleos de los ácinos, medialunas y conductos estriados eran menores en los ratones infectados. Estereológicamente, los volúmenes relativos ocupados por ácinos y conductos estriados fueron menores e, inversamente, fue mayor el volumen para el tejido conjuntivo de los machos infectados. Las densidades de superficie de ácinos y conductos fueron mayores, y el diámetro y el espesor de la pared menores, en este grupo. Por otro lado, la densidad de ácinos fue menor, y las de los conductos estriados y tejido conjuntivo, fueron mayores en las hembras infectadas. Las densidades de superficie de ácinos y conductos estriados fueron mayores, mientras que el diámetro y espesor de la pared de los ácinos fueron menores (y las de los conductos estriados mayores), en este grupo. La cepa RAL del T. cruzi causó un cuadro general de atrofia general en la glándula sublingual, con numerosos nidos de parásitos.

[Histometry of the sublingual gland in male and female mice (Mus musculus) infected with the RAL strain of the Chagas parasite, Trypanosoma cruzi]. / Histometria de la glándula sublingual de ratones (Mus musculus) machos y hembras infectados con la cepa RAL del parásito de Chagas, Trypanosoma cruzi.

The aim of this work was to analyze histologically and histometrically the sublingual gland of mice infected with the RAL strain of T. cruzi, according to the sex. Swiss mice (Mus musculus) were inoculated with 2 x 10(4) blood trypomastigotes of the RAL strain of T. cruzi. In the peak of the parasitemia (12th day) the mice were sacrificed, and the sublingual glands were fixed in ALFAC. HE-stained histological sections were evaluated histometrically. The parasitemia was higher in females. Histopatologically, acini of the infected animals were smaller, with scanty production of secretion, and smaller striated ducts. The nuclei of the demilunes were smaller and showed amastigote nests in the cytoplasm. Karyometrically, nuclei of the acini, demilunes and striated ducts were smaller in the infected mice. Stereologically, it was observed that relative volumes of acini and ducts were smaller and, inversely, relative volumen were greater for the conjunctive tissue in the infected males. The surface densities of acini and ducts were bigger and the diameter and thickness of the wall were smaller in this group. On the other hand, relative volume of acini was smaller and those of the ducts and conjunctive tissue were bigger in the infected females. The diameter and thickness of the wall of acini were smaller, and those of the striated ducts were bigger in this group. The RAL strain of T. cruzi caused general atrophy in the sublingual gland, with numerous nests of parasites in the glandular parenchyma.

Morfometría de la parótida de ratón infectado por la cepa RAL de Trypanosoma cruzi en función del sexo / Morphometry of the parotid Gland in mice infected by the RAL strain of Trypanosoma cruzi in function of the sex

Fueron estudiadas las alteraciones y el nivel de deterioro de las parótidas de animales infectados con la cepa RAL de Trypanosoma cruzi. Se utilizaron ratones albinos (Mus musculus) de ambos sexos, debido al dimorfismo sexual de las glándulas salivares, inoculados con 2 x 104 tripomastigotes sanguíneos de la cepa RAL del T. cruzi. Los animales fueron sacrificados al 12° día de infección, coincidiendo con el pico parasitémico. La parótida fue procesada histológicamente y, posteriormente, evaluada histopatológica y morfométricamente. Los resultados permitieron verificar intenso parasitismo en la glándula, la que presentó desorganización estructural y atrofia generalizada de acinos y conductos, más intensos en las hembras. Concluyendo, la cepa RAL del T. cruzi mostró un comportamiento atípico en relación a otras cepas, causando modificaciones más evidentes en las hembras, debido, posiblemente, a alteraciones hormonales desencadenadas por el T. cruzi.

They were studied the alterations and the level of deterioration of the parotid gland in mice infected with the RAL strain oí Trypanosoma cruzi. They were used albino mice (Mus musculus) of both sexes, due to the existence of sexual dimorphism of the salivary glands, inoculated with 2 x 104 blood trypomastigotes of the RAL strain of T cruzi. The animals were sacrificed at the 12th day of infection, coinciding with the parasitemic peak, and the parotid gland was histologically processed and histopathologically and histometrically studied. The results allow verifying intense parasitism in the parotid gland with structural disorganization and widespread atrophy of acini and ducts, more marked in the females. Concluding, the RAL strain of T cruzi shows an atypical behavior in relation to other strains, provoking more clear modifications in the females, probably due to the hormonal alterations motivated by the T cruzi.

Estudio morfométrico del hígado de ratón en la enfermedad de Chagas experimental / Morphometrical study of the mouse liver in the experimental Chagas' disease

El objetivo de este trabajo fue caracterizar histopatológicamente y morfométricamente las alteraciones del tejido hepático de ratón, durante la fase aguda de la infección por la cepa MORC-2 de Trypanosoma cruzi. Esta cepa mostró acentuado tropismo por el hígado, con numerosos nidos de amastigotes en los cortes examinados. El hígado de los animales infectados estaba constituido por células menores, con citoplasma granuloso. En algunas áreas, los sinusoides estaban congestionados y las células de Kupffer hipertróficas e hiperplásicas. El tejido hepático mostró focos circunscritos de células inflamatorias en áreas de necrosis, sinusoides, en torno de las venas centrolobulillares y de los espacios porta. La vena centrolobulillar estaba dilatada y congestionada, con necrosis focales y ruptura de la pared en algunos campos. Los espacios porta estaban desorganizados, a veces, con intenso infiltrado inflamatorio. En algunas áreas fue posible observar degeneración cística (spongis hepatis). Por todo el tejido hepático se observaron nidos de amastigotes, de tamaño variable, algunos rodeados por infiltrado inflamatorio crónico. En el espacio porta, el volumen relativo de los conductos biliares y vasos sanguíneos, así como la densidad de superficie de las arterias fueron mayores en el grupo infectado.

The objective of this work was to characterize histopatologically and morphometrically the alterations of the mouse liver during the acute infection by the MORC-2 strain of Trypanosoma cruzi. This strain showed marked tropism by the liver, with numerous nests of amastigotes in the examined sections. The liver of the infected animals was constituted by smaller cells, with granular cytoplasm. In some areas, the sinusoids were congested and the Kuppfer cells were hipertrofied and hiperplasic. The hepatic tissue showed circumscribed foci of inflammatory cells into necrotic areas, sinusoids, around the contrilobular veins and the portal spaces. The centrilobular vein was dilated and congested, with focal necrosis and rupture of the wall in some regions. The portal spaces were disorganized, sometimes with intense inflammatory infiltrate. In some areas it was possible to observe cystic degeneration (spongis hepatis). In the hepatic tissue, nests of amastigotes, of variable sizes, were observed, some surrounded by chronic inflammatory infiltrate. In the portal space, the relative volume of the biliary ducts and blood vessels, as well as the surface density of the arteries was greater in the infected group.

Transmission Electron Microscopy Study of the Neonatal Rat Tongue Mucosa Treated with Special Attention to the Bacteriae on the Epithelial Cell Membrane

RESUMEN: A través de miscroscopía electrónica de transmisión se examinaron las células del epitelio de la mucosa lingual de ratas Wistar recién nacidas. Los tejidos fueron fijados en solución de Karnovksy modificada e incluidos en resina Spurr. Se obtuvieron delgados cortes de 90 nm y se observaron al microscopio electrónico de transmisión Jeol 1010. Se encontró que las células epiteliales queratinizadas escamosas de la mucosa lingual expuestas al cadmio, presentaron grupos de numerosas bacterias las cuales estaban fijadas a las superficies de las membranas celulares. Los cocos y bacilos estaban fijados a las membranas celulares organizadas en pilas o columnas o al azar, como se aprecia claramente en las imágenes obtenidas a través de la microscopía electrónica de transmisión. Las imágenes mostraron que las bacterias estaban fijadas por estructuras fibrilares desde una a otra y desde las memebranas de las células epiteliales a las bacterias. El grupo control demostró que en las membranas celulares no era evidente la presencia de cadmio.

Efecto de la infección aguda por diferentes cepas de Trypanosoma cruzi sobre el crecimiento intrauterino de fetos de ratón / Effect of the acute infection by different strains of Trypanosoma cruzi intrauterine growth of the mouse fetuses

El objetivo de este trabajo fue evaluar los efectos de la infección aguda materna con diferentes cepas de T. cruzi sobre el crecimiento intrauterino del ratón. Animales grávidos, de 60 días, fueron inoculados i.p. con 2 x 105 tripomastigotes sanguíneos de T. cruzi (cepa colombiana, Y, Bolivia o RC). Los resultados muestran que la infección afecta el crecimiento intrauterino, con reducción de peso y de longitud del cuerpo, longitud del cordón umbilical, relación peso corporal/peso placentario y relación peso corporal/longitud del cordón umbilical. Las cepas usadas muestran comportamiento diferente. En general, la menos perjudicial para el crecimiento fue la cepa RC, mientras que las más deletéreas fueron las cepas Bolivia e Y. Las curvas parasitemicas de estas cepas tienen el crecimiento más rápido, alcanzando el máximo al 5o y 7o día, respectivamente. Como la inoculación fue hecha de modo a coincidir los niveles máximos de parasitemia con el fin de la gravidez, estas cepas causan un proceso infeccioso más rápido, con altos índices de parasitemia, sin permitir la adaptación materna.

Effects of cigarette smoke on the Meckel's cartilage of rat fetus: morphologic, morphometric and stereologic study.

The purpose of this study was to investigate the effects of cigarette smoke on the development of the embryo mandible (Meckel's) cartilage in rat fetuses. When inhaled by female Wistar rats between the 9th and the 12th day of pregnancy, cigarette smoke (5 cigarettes a day) caused intrauterine growth retardation, providing smaller fetuses and placentas. In fetuses from the experimental group, the histopathologic examination revealed a poorly developed Meckel's cartilage with smaller chondroblasts showing a scanty cytoplasm with spherical and paler central nuclei, as well as more abundant cartilage matrix. Morphometric analysis revealed that Meckel's cartilage lacunae were smaller in the fetuses from the experimental group, although not showing any remarkable alteration in shape. The results suggested that inhalation of cigarette smoke by pregnant rats during the organogenic period induced growth retardation and delayed cellular differentiation in rat fetal Meckel's cartilage.

Efectos del Albendazol en el Hígado de Feto de Rata: Estudios Morfológico y Morfométrico / Effects of Albendazole on Rat Fetuses Liver: Morphologic and Morphometric Studies

El objetivo del presente trabajo fue caracterizar morfológica, morfométrica y estereológicamente las alteraciones causadas por la administración de albendazol en ratas preñadas en el hígado de los fetos. Fueron usadas ratas Wistar, que recibieron entre los días 9 y 11 de la preñez, una dosis diaria de 5 mg/kg de peso de albendazol. Las ratas control recibieron volumen semejante de suero fisiológico en los mismos días. Al 20 día, las ratas fueron sacrificadas por inhalación de éter, siendo retirados los fetos e inmediatamente fijados en alfac por 24 h. Los fetos, úteros y placentas, luego de fijados, fueron secados en papel de filtro y pesados en balanza de precisión, siendo medidos los cordones umbilicales con nonio. Los cuerpos de los fetos fueron seccionados longitudinalmente e incluidos en parafina. Los cortes seriados de 6 µm de espesor, fueron teñidos con hematoxilina y eosina. Además del examen histopatológico, fueron utilizadas técnicas histométricas. Los resultados obtenidos, en las condiciones experimentales, sugieren que la exposición prenatal al albendazol actúa directamente en la embriogénesis, causando malformaciones como agenesia del rabo y fetos hidrópicos. En los fetos sin malformaciones, la droga causó retardo del desarrollo fetal, caracterizado por reducción de peso corporal, peso de la placenta y longitud del cordón umbilical, así como alteraciones estructurales hepáticas, reflejadas en hepatocitos menores con núcleos menores y citoplasma más escaso y aumento de la densidad numérica. Los megacariocitos eran mayores, con núcleos lobulados grandes, con mayor volumen relativo. Los sinusoides ocuparon un volumen relativo semejante en los fetos de los dos grupos estudiados. Los fetos tratados, además de las malformaciones, mostraron aspectos que sugieren inmadurez al ser comparados con los controles.

The objective of the present work was to characterize morphological, morphometrical and stereologically the hepatic alterations in rat fetuses, caused by the administration of albendazole during pregnancy. They were obtained fetuses of Wistar rats, which received in days 9, 10 and 11 of pregnancy a daily dose of 5 mg/Kg body weight of albendazole. The control rats received injections of saline in the same days. At the 20th day, the rats were sacrificed by anesthetic ether inhalation, the fetuses were removed and immediately fixed in alfac for 24 h. All the fetuses, uteri and placentas, after fixed, was dried in filter paper and weighed in a precision scale, whereas the umbilical cords were measured with a vernier. The bodies were longitudinally cut and embedded in paraffin. Six mm-thick serial sections were stained with hematoxylin and eosin. In addition to the histopatologic examination, histometric technics were used. The obtained results, in the used experimental conditions, suggest that prenatal exposition to albendazole directly acts on the embryogenesis, causing malformations, like agenesia of the tail and hydropic fetuses. In those fetuses without malformations, the drug acts on the fetal growth, causing modifications characterized by reduced body weight, placental weight and size of the umbilical cord, as well as structural alterations of the hepatic tissue, translated by smaller hepatocytes with smaller nuclei, and scanty cytoplasm but increased number density. The megacariocytes were more volumous, with greater lobulated nuclei, occupying a higher relative volume. The sinusoids occupied a similar relative volume in the fetuses of both studied groups. The treated fetuses, in addition to the malformations appeared to be immature, when compared to the controls.

Effects of cigarette smoke on the Meckel's cartilage of rat fetus: morphologic, morphometric and stereologic study

O objetivo deste estudo foi investigar os efeitos da fumaça de cigarros sobre o desenvolvimento da cartilagem mandibular (cartilagem de Meckel) do embrião de rato. Quando inalado por ratas Wistar, entre o 9º e o 12º dia de prenhez, a fumaça de cigarros (5/dia) provocou retardo do crescimento intrauterino, com fetos e placentas menores. Nos fetos do grupo experimental, o exame histopatológico revelou uma cartilagem de Meckel pouco desenvolvida, com condroblastos menores apresentando citoplasma escaso com núcleos mais pálidos, esféricos e centrais, assim como uma matrix cartilaginosa mais abundante. A análise morfométrica revelou que as lacunas da cartilagem de Meckel eram menores nos fetos do grupo experimental, não apresentando alteração significativa de sua forma. Os resultados sugeriram que a fumaça de cigarros inalada pelas ratas prenhes durante o período de organogênese induziu retardo tanto do crescimento quanto da diferenciação celular na cartilagem de Meckel dos fetos.

Immune Cells Depletion During Wound Healing as a Long-Term Effect of Undernutrition / Depleción de Células Inmunocitarias Durante la Curación de una Herida como Efecto de Desnutrición Postnatal

Undernutrition in early life is associated with a number of acute and chronic sequelae, and recovering is a controversial issue. Even if undernutrition in Brazil is declining, studies have shown that about 31% of brazilian children still present severe or moderate malnutrition. The present study goal was to induce early malnutrition in rats and observe short- (undernourished) and long-term (after recovered) effects on defense cells involved in wound healing. Undernutrition was produced by separating the pups from the mother for 10 hours/day during the suckling period (21 days after birth). As controls were used rats at same age not submitted to suckling restriction. Undernutrition and recovering states were assessed by body weight. Skin wounds were made on the shaved backs of all, undernourished, recovered and their controls, under tribromoethanol anesthesia. Aninals were sacrificed 1, 3, 7 and 14 days after surgery and the tissues were properly prepared and observed under light microscopy. Our results showed that: 1) neutrophils, lymphocytes and macrophages couting in healing area were lower in undernourished and in recovered animals as compared with their controls; 2) there were a basal deficiency in lymphocytes and macrophages numbers in recovered animals but not in those acutelly undernourished. These results allow us to conclude that post-nattally undernourished animals submitted to a nutritional rescue time showed a complete recovery in physical weight, but in spite of the physical recovery, the wound healing showed less defense cell density in healing areas suggesting long-term sequelae of early undernutrition.

La desnutrición postnatal está asociada a un conjunto de secuelas agudas y crónicas, y su recuperación es aún asunto controvertido. En Brasil, a pesar de estar disminuyendo la desnutrición, algunos estudios han demostrado que alrededor del 31% de los niños presentan malnutrición moderada o severa. El objetivo del presente estudio fue inducir una desnutrición precoz en ratas y observar los efectos inmediatos (desnutrición) y permanentes (depués de la recuperación) sobre las células de defensa involucradas en la cicatrización. La desnutrición fue provocada separando las crías de sus madres, por 10 horas diarias, durante el periodo de lactancia (21 días de nacidos). Como contoles fueron usadas ratas de la misma edad no sometidas a restrición láctea. Los estados de desnutrición y de recuperación fueron evaluados por el peso corporal. Las heridas fueron realizadas en la piel rasurada del dorso de los animales desnutridos, recuperados y controles, bajo anestesia con tribromoetanol. Los animales fueron sacrificados 1, 3, 7 y 14 días después de la cirugía y los tejidos de la región cicatricial fueron procesados histológicamente y examinados al microscopio óptico. Los resultados mostraron que: 1) el número de neutrófilos, linfocitos y macrófagos en la área de cicatrización, fue menor en los animales desnutridos y en recuperación que en los controles; 2) enlos animales recuperados hubo una deficiencia basal en el número de linfocitos y macrófagos, lo que no ocurrió en los animales con desnutrición aguda. Estos resultados permitieron concluir que los animales sometidos a desnutrición postnatal mostraron una recuperación completa en el peso físico después del periodo de recuperación nutricional, pero que la región de cicatrización mostró menor densidad de células de defensa, sugiriendo secuelas permanentes de la desnutrición postnatal.

Effect of cadmium on the floor of the mouth on rats during lactation.

Cadmium (Cd) present in the air, drinking water and food has the potential to affect the health of people, mainly those who live in highly industrialized regions. Cd affects placental function, may cross the placental barrier and directly modify fetal development. It is also excreted into milk. The body is particularly susceptible to Cd exposure during perinatal period. The effect on rat oral epithelium (floor of the mouth) after continuous exposure to drinking water containing low levels of Cd during lactation was studied. Female rats were supplied with ad libitum drinking water containing 300 mg/l of CdCl2 throughout the whole lactation period. Control animals received a similar volume of water without Cd. Lactating rats (21 day-old) were killed by lethal dose of anesthetic. The heads were retrieved, fixed in "alfac" solution (alcohol, acetic acid and formaldehyde) for 24 h, serially sectioned in frontal plane, at the level of the first molars. The 6 micro m sections were then stained with hematoxylin and eosin. Nuclear epithelium parameters were estimated, as well as cytoplasm and cell volume, nucleus/cytoplasm ratio, numeric and surface densities, and epithelial thickness. Mean body weight was 34.86 g for the control group and 18.56 g for the Cd-treated group. Histologically, the floor of the mouth epithelium was thinner in the treated group, with smaller and more numerous cells. In this experiment, Cd induced epithelial hypotrophy, indicating a direct action in oral mucosa cells, besides retarded development of the pups.

Effect of cadmium on the floor of the mouth on rats during lactation

O cádmio (Cd) do ar, da água e dos alimentos tem o potencial de afetar a saúde das pessoas, principalmente daquelas que vivem em regiões altamente industrializadas. O Cd afeta a função placentária, podendo atravessar a barreira placentária e provocar distúrbios no desenvolvimento fetal. Pode, também, ser excretado pelo leite. O organismo é particularmente susceptível à exposição ao Cd no período perinatal. Foi estudado o efeito da intoxicação por Cd no epitélio do soalho da boca de ratos expostos a baixos níveis do metal na água de bebedouro, durante a lactação. As ratas receberam água ad libitum contendo 300 mg/l de CdCl2 durante toda a lactação. Os animais controle receberam um volume similar de água sem Cd. Os filhotes foram sacrificados por sobredosagem anestésica no 21º dia. As cabeças dos animais foram separadas, fixadas em solução de "alfac" (álcool, ácido acético e formaldeído) por 24 h, seccionadas seriadamente em planos frontais ao nível dos primeiros molares, e os cortes de 6 µm foram corados com hematoxilina-eosina. Foram estimados os parâmetros nucleares do epitélio, assim como os volumes citoplasmático e celular, a relação núcleo/citoplasma, as densidades numérica e superficial e a espessura epitelial. O peso corporal médio do filhote foi de 34,86 g no grupo controle e 18,56 g no tratado. Histologicamente, o epitélio dos animais tratados mostrou-se adelgaçado, constituído de células abundantes e menores. Neste experimento, o Cd ocasionou um quadro de hipotrofia epitelial, indicando uma ação direta nas células epiteliais da mucosa oral, além de retardar o desenvolvimento dos filhotes intoxicados.