Débora de Mello Gonçales Sant'Ana

Effects of infection with Toxoplasma gondii oocysts on the intestinal wall and the myenteric plexus of chicken (Gallus gallus)

This paper aims to analyze the effects of the Toxoplasma gondii infection in the intestinal wall and myenteric plexus of chicken (Gallus gallus). Ten 36-day-old chickens were separated into two groups: control and experimental, orally inoculated with oocysts of the T. gondii strain M7741 genotype III. After 60 days the birds were submitted to euthanasia and had their duodenum removed. Part of the intestinal segments was submitted to histological routine, HE staining, PAS histochemical technique, and Alcian Blue. Qualitative analysis of the intestinal wall and comparative measurements among the groups with respect to total wall thickness, muscle tunic, mucosa, and tunica mucosa were carried out. Caliciform cells were quantified. The other part of the intestinal segments was fixed in formol acetic acid and dissected having the tunica mucosa and the tela submucosa removed. Neurons were stained with Giemsa, counted, and measured. Chickens from the experimental group presented diarrhea and inflammatory infiltrates in the tunica mucosa, thickness reduction of all the parameters assessed in the intestinal wall, and an increase of the number of caliciform cells. There was a ~70% reduction regarding the intensity of myenteric neurons; and the remaining cells presented a reduction of ~2.4% of the perikarion and ~40.5% of the nucleus (p<0.05). Chronic infection induced by T. gondii oocysts resulted in intestinal wall atrophy, mucin secretion increase, death and atrophy of chicken myenteric plexus neurons. Death and atrophy of myenteric plexus neurons may be related with the causes of diarrhea observed in chickens with toxoplasmosis.

Chronic infection with Toxoplasma gondii causes myenteric neuroplasticity of the jejunum in rats

Toxoplasma gondii is an aetiological agent of toxoplasmosis, which commonly causes diarrhoea in a number of species. This observation and the parasites affinity for the nervous tissue support the theory that T. gondii infection may affect the myenteric neurons. The aim of this study was to evaluate the changes caused by T. gondii (genotype III) in the myenteric neurons of the jejunum in rats. Fifteen rats were distributed into three groups: control (CG), inoculated for 30 days (G30) and inoculated for 90 days (G90). Rats from the G30 and G90 groups received an oral inoculum with 500 oocysts from a genotype III (M7741) T. gondii strain. At 180 days of age, all animals were anaesthetised and euthanised. Whole mounts were stained by using Giemsa (total population) and NADPH-diaphorase (nitrergic subpopulation) histochemistry. Maintenance of the width, length, area and neuronal density was observed; there was neuronal atrophy in the G30 group and a tendency to hypertrophy in the G90 group. Rats inoculated orally with sporulated oocysts did not show clinical illness or macroscopic or microscopic lesions, as do the majority of animal species. Therefore, infection was confirmed by a serum agglutination test; 30 days of infection caused increased weight gain and atrophy of myenteric neurons. At 90 days post-infection, weight gain became normal, and myenteric neurons hypertrophied.

Quantitative and morphometric changes of subpopulations of myenteric neurons in swines with toxoplasmosis

The consequences of the infection caused by Toxoplasma gondii in myenteric neurons of the jejunum of swines reactive to NADH-diaphorase and NADPH-diaphorase were evaluated in this study. Ten 88-day-old mixed-breed swines (Pietrain and Wessex) were assigned into two groups: Control (n=5) and Experimental (n=5), which orally received 5000 sporulated oocysts from a genotype III T. gondii strain. After 30days, the animals were anesthetized, having part of their jejunum removed and stained with NADPH-diaphorase and NADH-diaphorase. NADPHd-p neurons (nitrergic) presented increase of the number of cells per ganglion and hypertrophy. The number of NADHd-p neurons (metabolic more active) and their nuclear area decreased.

Intestinal ascending colon morphometrics in rats submitted to severe protein malnutrition

El objetivo de este trabajo fue verificar los efectos de la desnutricion proteica severa sobre la morfometria de la pared intestinal del colon ascendente de ratas adultas. Fueron utilizadas 12 ratas (90 dias de edad), divididas en dos grupos: control (n=5) y desnutrido (n=7). En los 90 dias siguientes, las ratas del grupo control recibieron racion con 24% de contenido proteico y los del grupo desnutrido con 4%. Los animales fueron eutanasiados de acuerdo al protocolo anestesico. Segmentos del colon fueron retirados y sometidos a procesamiento histologico de rutina. Los cortes fueron tenidos con HE y tecnicas histoquimicas para mucinas. El analisis morfometrico mostro la mantencion de la pared total y del grosor de la tunica muscular, y reduccion en el espesor de la tunica mucosa, en el numero de celulas caliciformes, en la profundidad de las criptas y en la altura de los enterocitos y de sus nucleos, en los animales desnutridos. Los datos obtenidos sugieren que la desnutricion proteica provoca alteraciones en la morfometria intestinal del colon ascendente de ratas adultas, principalmente en tejidos de alto indice de renovacion celular como la mucosa y, consecuentemente, de sus estructuras como los enterocitos, celulas caliciformes y criptas.

Effect of protein and vitamin B deficiency on the morpho-quantitative aspects of the myenteric plexus of the descending colon of adult rats

We carried out this work with the purpose of studying the effects of protein and vitamin B deficiency on the morphologic and quantitative aspects of the myenteric plexus of the descending colon of adult Rattus norvegicus. Twenty-eight rats were divided in two groups, one of them receiving chow with 22% protein level (control) and the other fed with chow having 8% protein level without vitamin B supplementation, during 120 days. Whole-mounts of the descending colon were prepared and stained with Giemsa, NADH-diaphorase and NADPH-diaphorase. The undernourished rats had a body weight 11.84% less than the control group. Relative to the controls, the experimental group had a colonic area 48% smaller, 51.9% less Giemsa-stained neurons, 28.3% less NADH-diaphorase positive neurons and 24.2% less NADPH-diaphorase positive neurons.

Metopism in Adult Skulls from Southern Brazil

La sutura metopica se encuentra entre las tuberosidades del hueso frontal, existiendo variaciones en relacion a la fecha exacta de su cierre, ocurriendo entre el primero y el decimo ano de vida, pudiendo persistir hasta la vida adulta (metopismo). Se realizo un estudio en 71 craneos secos, de individuos adultos, brasilenos, de ambos sexos (43 masculinos y 28 femeninos), con edades variando entre 25-80 anos de edad, pertenecientes a los osarios del Laboratorio de Anatomia Humana de la Universidad Paranaense - UNIPAR, Brasil. La presencia de metopismo fue observada en el 7,04% (05/71) de los craneos estudiados, siendo 80% (4/5) femeninos y solo 20% (1/5) masculinos. La sutura metopica incompleta fue encontrada en el 32,39% de los casos (23/71), siendo mas frecuente en el sexo femenino, 60,86% (14/23) que en el sexo masculino 39,13% de los casos (9/23). Las suturas metopicas presentaron variaciones en su morfologia, siendo la forma mas frecuente la del tipo linear, 69,56% (16/23). Fueron observadas distintas suturas metopicas en los diversos tipos antropometricos de craneo. Las suturas incompletas predominaron en los braquicraneos y las suturas metopicas completas tuvieron la misma incidencia en los mesocraneos de 40% (2/5) y dolicocraneosde 40% (2/5)

Neuronal changes caused by Trypanosoma cruzi: an experimental model

Define an experimental model by evaluating quantitative and morphometric changes in myenteric neurons of the colon of mice infected with Trypanosoma cruzi. Twenty-eight Swiss male mice were distributed into groups: control (CG, n=9) and inoculated with 100 (IG(100), n=9) and 1000 (IG(1000), n=10) blood trypomastigotes, Y strain-T. cruzi II. Parasitemia was evaluated from 3-25 days post inoculation (dpi) with parasites peak of 7.7 × 10(6) and 8.4 × 10(6) trypomastigotes/mL at 8(th) dpi (p>0.05) in IG(100) and IG(1000), respectively. Chronic phase of the infection was obtained with two doses of 100mg/Kg/weight and one dose of 250mg/Kg/weight of Benznidazole on 11, 16 and 18 dpi. Three animals from each group were euthanized at 18, 30 and 75 dpi. The colon was stained with Giemsa. The quantitative and morphometric analysis of neurons revealed that the infection caused a decrease of neuronal density on 30(th) dpi (p<0.05) and 75 dpi (p<0.05) in IG(100) and IG(1000). Infection caused death and neuronal hypertrophy in the 75(th) dpi in IG(100) and IG(1000) (p<0.05, p<0.01). The changes observed in myenteric neurons were directly related to the inoculate and the time of infection.

Análise morfométrica da parede intestinal e dinâmica de mucinas secretadas no íleo de frangos infectados por Toxoplasma gondii

The effects of toxoplasmosis on the intestinal wall morphometry and the dynamic of mucins secreted in the chicken ileum were analyzed. Sixteen 26-day-old, male, Cobb broiler chicks (Gallus gallus) were used and randomly divided into three groups (G1, G2 and G3). G1 received no inoculum characterizing the control group, G2 was inoculated with tissue cysts of ME49 strain of Toxoplasma gondii, and G3 was inoculated with oocytes of M7741 strain of T. gondii. After 60 days of inoculation, the animals were killed and had their ileum collected and submitted to histological processing. Tranversal cuts (4mm) were stained with Hematoxilin-Eosine (HE), Periodic Acid Schiff (PAS), Alcian Blue pH 2.5 and Alcian Blue (AB) pH 1.0. Intestinal wall increase was noticed for the animals from G2 - mostly the muscle tunic, the muscularis mucosae, and the mucous tunic, including the increase of secretion of neutral mucins. The animals from G3 presented atrophy of the intestinal wall - mostly the mucous tunic, and increase of the secretion of neutral mucins.

Quantitative Study of the Myenteric Plexus of the Descending Colon of Young Rats Subjected to Intense Protein Deficiency

Estudiamos los efectos cronicos de una dieta severamente hipoproteica sobre los aspectos cuantitativos del plexo mienterico del colon descendente de ratones jovenes. 18 ratones fueron divididos en dos grupos, a uno de estos grupos se le dio racion con contenido proteico del 26% (control) y al otro, racion con contenido proteico del 4%. Se mantuvo el balance vitaminico y mineral, durante 12 semanas. Elaboramos los preparados de membrana del colon descendente y marcamos las neuronas del plexo mienterico con Giemsa y NADPH-diaforasa. Los ratones del grupo experimental presentaron deficit de peso corporal (54,23%) y del area del colon descendente (48,14%); ademas, observamos que no hubo alteracion en el numero total de neuronas en todo el colon; sin embargo, hubo una disminucion en la marcacion de neuronas NADPH-diaforasa positivas (37,80%). Los resultados son discutidos, respecto a la prioridad que ciertos tipos celulares pudiesen tener, con la menor disponibilidad de nutrientes

Regional differences in the number and type of myenteric neurons in the descending colon of rats

The purpose of this study was to analyze the neuronal density of the myenteric plexus of the intermediate and antimesocolic regions of the descending colon of rats. Whole-mounts were stained with three different techniques of neuronal evidenciation. Through counts of the number of neurons in an area of 6.64 mm under light microscopy, we found 1,271 +/- 227.54 neurons with Giemsa in the intermediate region and 1,234 +/- 225.92 neurons in the antimesocolic region; with the NADH-diaphorase technique we found 530 +/- 92.97 neurons in the intermediate region and 539 +/- 146.72 neurons in the antimesocolic region; and through the NADPH-diaphorase histochemistry, we found 417 +/- 34.42 neurons in the intermediate region and 547 +/- 84.01 neurons in the antimesocolic region. We conclude that there is a variation in the density of NADPH-diaphorase positive neurons in the intestinal circumference; that the NADH-diaphorase positive neuronal subpopulation represented 42.7% of that stained with Giemsa; and that the NADPH-diaphorase positive neurons represented 37.8% of the whole myenteric population.