Time-course effects of aerobic exercise training on cardiovascular and renal parameters in 2K1C renovascular hypertensive rats

Exercise training (Ex) has been recommended for its beneficial effects in hypertensive states. The present study evaluated the time-course effects of Ex without workload on mean arterial pressure (MAP), reflex bradycardia, cardiac and renal histology, and oxidative stress in two-kidney, one-clip (2K1C) hypertensive rats. Male Fischer rats (10 weeks old; 150–180 g) underwent surgery (2K1C or SHAM) and were subsequently divided into a sedentary (SED) group and Ex group (swimming 1 h/day, 5 days/week for 2, 4, 6, 8, or 10 weeks). Until week 4, Ex decreased MAP, increased reflex bradycardia, prevented concentric hypertrophy, reduced collagen deposition in the myocardium and kidneys, decreased the level of thiobarbituric acid-reactive substances (TBARS) in the left ventricle, and increased the catalase (CAT) activity in the left ventricle and both kidneys. From week 6 to week 10, however, MAP and reflex bradycardia in 2K1C Ex rats became similar to those in 2K1C SED rats. Ex effectively reduced heart rate and prevented collagen deposition in the heart and both kidneys up to week 10, and restored the level of TBARS in the left ventricle and clipped kidney and the CAT activity in both kidneys until week 8. Ex without workload for 10 weeks in 2K1C rats provided distinct beneficial effects. The early effects of Ex on cardiovascular function included reversing MAP and reflex bradycardia. The later effects of Ex included preventing structural alterations in the heart and kidney by decreasing oxidative stress and reducing injuries in these organs during hypertension.

Cardiac and renal effects induced by different exercise workloads in renovascular hypertensive rats

We examined the effect of exercise training (Ex) without (Ex 0 percent) or with a 3 percent workload (Ex 3 percent) on different cardiac and renal parameters in renovascular hypertensive (2K1C) male Fisher rats weighing 150-200 g. Ex was performed for 5 weeks, 1 h/day, 5 days/week. Ex 0 percent or Ex 3 percent induced similar attenuation of baseline mean arterial pressure (MAP, 119 ± 5 mmHg in 2K1C Ex 0 percent, N = 6, and 118 ± 5 mmHg in 2K1C Ex 3 percent, N = 11, vs 99 ± 4 mmHg in sham sedentary (Sham Sed) controls, N = 10) and heart rate (HR, bpm) (383 ± 13 in 2K1C Ex 0 percent, N = 6, and 390 ± 14 in 2K1C Ex 3 percent, N = 11 vs 371 ± 11 in Sham Sed, N = 10,). Ex 0 percent, but not Ex 3 percent, improved baroreflex bradycardia (0.26 ± 0.06 ms/mmHg, N = 6, vs 0.09 ± 0.03 ms/mmHg in 2K1C Sed, N = 11). Morphometric evaluation suggested concentric left ventricle hypertrophy in sedentary 2K1C rats. Ex 0 percent prevented concentric cardiac hypertrophy, increased cardiomyocyte diameter and decreased cardiac vasculature thickness in 2K1C rats. In contrast, in 2K1C, Ex 3 percent reduced the concentric remodeling and prevented the increase in cardiac vasculature wall thickness, decreased the cardiomyocyte diameter and increased collagen deposition. Renal morphometric analysis showed that Ex 3 percent induced an increase in vasculature wall thickness and collagen deposition in the left kidney of 2K1C rats. These data suggest that Ex 0 percent has more beneficial effects than Ex 3 percent in renovascular hypertensive rats.

Prevalência de anticorpos anti-Rickettsia spp. em cães da cidade de Belo Horizonte, MG / Prevalence of antibodies anti-Rickettsia in dogs from Belo Horizonte, MG, Brazil

A cross-sectional study was conducted to determine the seroprevalence of anti-Rickettsia spp. in dogs from Belo Horizonte, MG. For this purpose, serum samples from 453 dogs were collected during the rabies vaccination campaign and tested by the indirect immunofluorescence assay (IFA) using five antigens: Rickettsia bellii, Rickettsia amblyommii, Rickettsia rickettsii, Rickettsia parkeri, and Rickettsia felis. The endpoint titer reacting with each antigen was determined and serum was considered positive if it reacted at the 1:64 dilution. Serum showing titer for a Rickettsia species at least four-fold higher than that observed for any other Rickettsia species was considered homologous to the first Rickettsia species. Only three (0.66%) dogs reacted positively to at least one Rickettsia species and one serum showed to be homologous to R. rickettsii. These results showed a low prevalence of antibodies anti-Rickettsia spp. in dogs from Belo Horizonte city. However, other serosurvey needs to be performed for surveillance of the endemic status of the disease in the municipal district.

Association of polymorphisms at the ADIPOR1 regulatory region with type 2 diabetes and body mass index in a Brazilian population with European or African ancestry

Association studies between ADIPOR1 genetic variants and predisposition to type 2 diabetes (DM2) have provided contradictory results. We determined if two single nucleotide polymorphisms (SNP c.-8503G>A and SNP c.10225C>G) in regulatory regions of ADIPOR1 in 567 Brazilian individuals of European (EA; N = 443) or African (AfA; N = 124) ancestry from rural (quilombo remnants; N = 439) and urban (N = 567) areas. We detected a significant effect of ethnicity on the distribution of the allelic frequencies of both SNPs in these populations (EA: -8503A = 0.27; AfA: -8503A = 0.16; P = 0.001 and EA: 10225G = 0.35; AfA: 10225G = 0.51; P < 0.001). Neither of the polymorphisms were associated with DM2 in the case-control study in EA (SNP c.-8503G>A: DM2 group -8503A = 0.26; control group -8503A = 0.30; P = 0.14/SNP 10225C>G: DM2 group 10225G = 0.37; control group 10225G = 0.32; P = 0.40) and AfA populations (SNP c.-8503G>A: DM2 group -8503A = 0.16; control group -8503A = 0.15; P = 0.34/SNP 10225C>G: DM2 group 10225G = 0.51; control group 10225G = 0.52; P = 0.50). Similarly, none of the polymorphisms were associated with metabolic/anthropometric risk factors for DM2 in any of the three populations, except for HDL cholesterol, which was significantly higher in AfA heterozygotes (GC = 53.75 ± 17.26 mg/dL) than in homozygotes. We conclude that ADIPOR1 polymorphisms are unlikely to be major risk factors for DM2 or for metabolic/anthropometric measurements that represent risk factors for DM2 in populations of European and African ancestries.

Effect of polymorphisms of the MTHFR and APOE genes on susceptibility to diabetes and severity of diabetic retinopathy in Brazilian patients

Diabetes mellitus (DM) is a highly prevalent complex genetic disorder. There has been a worldwide effort in the identification of susceptibility genes for DM and its complications, and the 5-10-methylenetetrahydrofolate reductase (MTHFR) and apolipoprotein-E (APOE) genes have been considered good candidate susceptibility genes to this condition. The objectives of the present study were to determine if the 677T MTHFR and epsilon2/epsilon3/epsilon4 APOE alleles are risk factors for DM and for severity of diabetic retinopathy (DR). A total of 248 individuals were studied: 107 healthy individuals and 141 diabetic patients (46 with type 1 diabetes and 95 with type 2 diabetes), who also had DR (81 with non-proliferative DR and 60 with proliferative DR). The polymorphisms were analyzed by PCR followed by digestion with restriction enzyme or the single-nucleotide primer extension method. No evidence of association between the 677TT genotype of MTHFR gene and DM [cases: TT = 10/95 (10.6 percent); controls: TT = 14/107 (13 percent)] or with severity of DR was observed [cases: TT = 5/60 (8.5 percent); controls: TT = 9/81 (11.1 percent); P > 0.05]. We also did not find evidence of an association between APOE alleles and proliferative DR (epsilon2, epsilon3 and epsilon4 in cases: 9, 76, and 15 percent, and in controls: 5, 88, and 12 percent, respectively) but the carriers of epsilon2 allele were more frequent among patients with type 2 DM and DR than in controls [cases: 15/95 (15.8 percent); controls: 7/107 (6.5 percent); P < 0.05]. Therefore, our results suggest that the epsilon2 allele/APOE might be a risk factor for diabetes in the Brazilian population.

Baroreflex function in conscious rats submitted to iron overload

Our hypothesis is that iron accumulated in tissue, rather than in serum, may compromise cardiovascular control. Male Fischer 344 rats weighing 180 to 220 g were divided into 2 groups. In the serum iron overload group (SIO, N = 12), 20 mg elemental iron was injected ip daily for 7 days. In the tissue iron overload group (TIO, N = 19), a smaller amount of elemental iron was injected (10 mg, daily) for 5 days followed by a resting period of 7 days. Reflex heart rate responses were elicited by iv injections of either phenylephrine (0.5 to 5.0 µg/kg) or sodium nitroprusside (1.0 to 10.0 µg/kg). Baroreflex curves were determined and fitted to sigmoidal equations and the baroreflex gain coefficient was evaluated. To evaluate the role of other than a direct effect of iron on tissue, acute treatment with the iron chelator deferoxamine (20 mg/kg, iv) was performed on the TIO group and the baroreflex was re-evaluated. At the end of the experiments, evaluation of iron levels in serum confirmed a pronounced overload for the SIO group (30-fold), in contrast to the TIO group (2-fold). Tissue levels of iron, however, were higher in the TIO group. The SIO protocol did not produce significant alterations in the baroreflex curve response, while the TIO protocol produced a nearly 2-fold increase in baroreflex gain (-4.34 ± 0.74 and -7.93 ± 1.08 bpm/mmHg, respectively). The TIO protocol animals treated with deferoxamine returned to sham levels of baroreflex gain (-3.7 ± 0.3 sham vs -3.6 ± 0.2 bpm/mmHg) 30 min after the injection. Our results indicate an effect of tissue iron overload on the enhancement of baroreflex sensitivity.

Ocorrência de Haemophilus influenzae em crianças atendidas em creches / Occurrence of Haemophilus influenzae in children attending day-care centers

As doenças provocadas por cepas de Haemophilus influenzae tipo b (Hib),como por exemplo, conjuntivite, otite média, meningite e pericardite têm apresentado uma sensível diminuição em resposta ao uso da vacina anti Hib no esquema de vacinação nacional.No entanto, com a eliminação da colonização da nasofaringe por Hib, abre-se a possibilidade da substituição de cepas colonizadoras que apresentam este sorotipo capsular por outros sorotipos ou pela colonização por H.influenzae não tipavel (NTHi).Neste sentido, as creches representam um fator de risco para a transmissão das bactérias em função do prolongado e intenso contacto entre as crianças neste ambiente.O objetivo do presente estudo foi apresentar uma revisão atualizada sobre a colonização e transmissão de H.influenzae em crianças saudáveis que freqüentam creches.Concluiu-se que as crianças que freqüentam creches devem ser continuamente monitoradas, para se verificar a eliminação da colonização na nasofaringe por Hib ou a sua substituição por cepas de outros sorotipos ou NTHi.

Relato de caso: abscesso esplênico / Report of case: esplenic abscess

Os abscessos esplênicos constituem uma patologia incomum, encontrada em 0,14 a 0,7 por cento em séries de necropsias. O diagnóstico geralmente é difícil, pois sua apresentaçäo clínica é inespecífica1. Caso o diagnóstico e o tratamento näo sejam realizados precocemente, a evoluçäo fatal é freqüente2,3. Os autores relatam um caso de abscesso esplênico, e enfatizam a terapêutica adotada, que foi exclusivamente clínica, numa patologia onde a conduta praticamente padronizada é a esplenectomia ou drenagem percutânea, ambos acompanhados de antibioticoterapia.

Factors favoring houseplant container infestation with Aedes aegypti larve in Marilia, Sao Paulo, Brazil / Factores que favorecen la infestación de recipientes con plantas domésticas por larvas de Aedes aegypti en Marília, São Paulo, Brasil

Desde 1985, después de la reinfestación de mosquitos Aedes aegypti (L.) en el Estado de São Paulo, se encontró que ­a pesar de la diseminación de mensajes educativos destinados a su control­ las macetas y floreros son un hábitat importante de las larvas. Los objetivos de este estudio fueron identificar las macetas y floreros como hábitats de larvas de mosquitos en relación con su número y grado de infestación, los tipos de plantas involucradas y la localización específica de las larvas; investigar los nombres locales de las plantas domésticas y examinar los factores que afectan al cumplimiento de las medidas de control. Los resultados mostraron un promedio de más de cuatro posibles hábitats de larvas relacionados con plantas por cada sitio, de los cuales solo 0,4% tenían el vector. Los recipientes para plantas representaron 31% de todos los receptáculos con larvas de A. aegypti. A pesar de que de una muestra de 126 personas entrevistadas enumeraron 105 nombres de plantas domésticas, 49% de las plantas asociadas con larvas fueron solo de dos tipos: helechos y la planta ornamental Dieffenbachia avoena. La evidente falta de voluntad de la población para aceptar las medidas de control contra A. aegypti en lo que respecta a plantas domésticas parece deberse a la poca frecuencia relativa de A. aegypti en los recipientes domésticos, la falta de confianza en los programas de control como fuente idónea de información sobre plantas y la opinión de que las medidas de control recomendadas son dañinas para las plantas. Actualmente se está planeando una intervención para el control del dengue en la que se usará material educativo que trata específicamente sobre las plantas cuyos recipientes albergan con mayor frecuencia las larvas de A. aegypti. También se hará uso de fuentes de información botánica con mayor credibilidad en materia de plantas. Además, se formulará un plan diferente con un enfoque más atractivo desde el punto de vista de la salud de las plantas para incrementar su posibilidad de aceptación.

Desde 1985, después de la reinfestación de mosquitos Aedes aegypti (L.) en el Estado de São Paulo, se encontró que ­a pesar de la diseminación de mensajes educativos destinados a su control­ las macetas y floreros son un hábitat importante de las larvas. Los objetivos de este estudio fueron identificar las macetas y floreros como hábitats de larvas de mosquitos en relación con su número y grado de infestación, los tipos de plantas involucradas y la localización específica de las larvas; investigar los nombres locales de las plantas domésticas y examinar los factores que afectan al cumplimiento de las medidas de control. Los resultados mostraron un promedio de más de cuatro posibles hábitats de larvas relacionados con plantas por cada sitio, de los cuales solo 0,4% tenían el vector. Los recipientes para plantas representaron 31% de todos los receptáculos con larvas de A. aegypti. A pesar de que de una muestra de 126 personas entrevistadas enumeraron 105 nombres de plantas domésticas, 49% de las plantas asociadas con larvas fueron solo de dos tipos: helechos y la planta ornamental Dieffenbachia avoena. La evidente falta de voluntad de la población para aceptar las medidas de control contra A. aegypti en lo que respecta a plantas domésticas parece deberse a la poca frecuencia relativa de A. aegypti en los recipientes domésticos, la falta de confianza en los programas de control como fuente idónea de información sobre plantas y la opinión de que las medidas de control recomendadas son dañinas para las plantas. Actualmente se está planeando una intervención para el control del dengue en la que se usará material educativo que trata específicamente sobre las plantas cuyos recipientes albergan con mayor frecuencia las larvas de A. aegypti. También se hará uso de fuentes de información botánica con mayor credibilidad en materia de plantas. Además, se formulará un plan diferente con un enfoque más atractivo desde el punto de vista de la salud de las plantas para incrementar su posibilidad de aceptación.

Effect of high ingestion of dehydrated pumklin (Cucurbita pepo L. ) on the cholesterol metabolism and on the hepatic histology in mice

The hypercholesterolemia is one of the most relevant risk factors in atherosclerosis, the latter being responsible for a high mortality in most Western countries. A high intake of foods from plant origin is one of the recommendations for the control of hypercholesterolemia, probably because of their fiber content. This study was designed to evaluate the effects of the ingestion a pumpkin-based diet on cholesterol levels. Fifty mices were divided in three groups: I, animals fed on normocholesterolemic control diet: II, animals fed on a hypercholesterolemic diet; III, animals fed on a hypercholesterolemic diet containing dehydrated pumpkin during 8 weeks. The results showed that dehydrated pumpkin, when administered in high concentration in the diet, reduced the levels of plasmatic and hepatic cholesterol but may caue relevant lesions in liver. Further studies are necessary to evaluate the right proportion of pumpkin to reduce the cholesterolemia without undesirable effects. This study reinforces the need for the continuous support of an experienced histopathologist to detect eventual damage that are not evident on macroscopic examination in all nutritional studies involving tests with diets

Cefotaxima vs. cefalotina-gentamicina en el primer episodio febril de pacientes con tumores sólidos y neutropenia de corta duración / Cefotaxime vs Cephalotin-Gentamicin in the first febrile episode of patients having solid tumors and short-term neutropenia

Las infecciones no tratadas en un paciente neutropénico son rápidamente fatales y está plenamente justificado el uso de antibióticos en forma empírica. En el Instituto Nacional de Enfermedades Neoplásicas (INEN) el régimen de elección habitual para pacientes con el primer episodio febril con tumores sólidos y neutropenia de corta duración, es la asociación de gentamicina más cefalotina. Con el efecto de comparar la eficacia y toxicidad de un régimen de monoterapia con cefotaxima con este régimen combinado, llevamos a cabo un estudio prospectivo y randomizado comparando cefotaxima (1 g/8 h) versus la combinación de cefalotina (1 g/6 h) y gentamicina (4 mg/kg/día-dosis única-). Seleccionamos pacientes con tumores sólidos en el primer episodio febril que recibieron quimioterapia y desarrollaron neutropenia menor de 1000 neutrófilos/mm3. Con una duración esperada menor de 10 días. Se incluyeron 64 pacientes en el brazo de cefotaxima y 72 en el de cefalotina-gentamicina. El estudio se llevó a cabo entre mayo de 1993 hasta junio de 1994. La tasa de respuestas para el grupo de pacientes tratados con cefotaxima fue 75 por ciento y para el grupo tratado con cefalotina-gentamicina 69 por ciento. Las tasas de respuestas completas en los pacientes con infecciones microbiológicamente documentadas fueron 65.5 por ciento para el brazo de cefotaxima y 63.4 por ciento para el brazo de cefalotina-gentamicina. Los índices de falla fueron 23 por ciento para los pacientes incluidos en el brazo de cefotaxima y 30 por ciento para los pacientes tratados con cefalotina-gentamicina. No se demostró diferencias significativas en los índices de respuesta entre los dos brazos de tratamiento. No observamos efectos tóxicos secundarios que obligaran a suspender el tratamiento en ninguno de los dos esquemas. En conclusión: los índices de respueta obtenidos con los dos esquemas de tratamiento son adecuados en nuestro medio para la población de pacientes portadores de tumores sólidos que reciben quimioterapia y presenten un efecto infeccioso durante un período de neutropenia menor de 10 días. La combinación cefalotina-gentamicina requiere no sólo de un esquema posológico de mayor complejidad sino que también tiene una toxicidad potencialmente mayor y requiere de monitorización estrecha. La eficacia terapéutica fue mayor en el grupo que recibió cefotaxima, diferencia que no alcanzó significación estadística

Protective effect of Saccharomyces boulardii against the cholera toxin in rats

The effect of orogastric administration of Saccharomyces boulardii on the anatomopathological aspect of the jejunal villi was studied in male Fischer rats (weighing about 40 g) orogastrically infected with a culture of Vibrio cholerae. Experimental and control groups received lyophilized S. boulardii (25 mg suspended in 0.5 ml saline) or 0.5 ml saline, respectively, three times a day for 10 days by gastric intubation. On day 5 of treatment, 0.5 ml of a culture of V. cholerae containing 10(8) viable cells was inoculated by gastric intubation into both groups. Histopathological examination of the jejunal mucosa showed extensive lesions of the superficial epithelium of the villi from the control group whereas few lesions of this superficial epithelium were observed in the experimental group. These data show that the inhibition of the action of the cholera toxin on enterocytes by S. boulardii suggested by recent results in vitro can be demonstrated in vivo

The effect of chronic ingestion of ethanol on modulation of granulomatous inflammation in experimental schistosomiasis in mice

We studied the role of ethanol on the modulation of liver granulomata around Schistosoma mansoni eggs in mice. Albino mice, receiving 7 ethanol as the sole drinking liquid, at 60 and 90 days post-infection, presented smaller granulomata than controls did, when sacrificed at 120 days post-infection. No differences in diameters could be observed, when ethanol was given 4 months before up to 120 days after infection. The results suggested that modulation of schistosome granulomata by ethanol ingestion varies with time and duration of drug consumption.

Intragastric infection of conventional and germfree mice with Giardia lamblia

The effects of experimental infection with Giardia lamblia were studied in 30-day old conventional and germfree CFW mice (7 animals in each group) of both sexes. Cysts were observed in the feces of both groups 6 to 7 days after intragastric infection of each animal with about 2.5 x 10 5 G. lamblia trophozoites. Fecal cyst level was statisticaly higher in germfree mice (abouth 10 5 cysts/g feces) when compared with the conventional group (about 10 4 cysts/g feces). The peak of infection in the conventional group apparently occurred on the 10th day after infection as indicated by an increase of fecal weight and by histopathological examination. Intense infiltration of the lamina propria and high reactional hyperplasia of the lymphoiud component were observed in the conventional group. There was no infiltration or hyperplasia in germfree infected mice and fecal weight was relatively constant throughout the experiment. These results suggest that, as is the case for other intestinal pathogenic protozoa, the intestinal microflora is indispensable for the expression of the pathogenicity but not for the multiplication of G. lamblia

The acute phase of experimental infection with Trypanosoma cruzi is more severe in mice monoassociated with strict anaerobic bacteria

The influence of some components of the normal human intestinal flora on the acute phase of experimental infection with strain CL of Trypanosoma cruzi was studied in 30-day old germfree or gnotobiotic CFW (LOB) mice monassociated with Bacteroids fragilis, Peptostreptococcus sp or Clostridium sp by intragastrical inoculation of 10 6 bacteria 10 days before the intraperitoneal infections with 5 x 10 3 trypomastigotes/ g body weight. Significantly earlier parasitemia peak and mortality were observed in Bacteroides fragilis and Clostridium-associated mice (16.75 ñ 0.96 and 15.00 ñ 1.15 days, respectively) when compared with germfree animals (18.83 ñ 1.17 days). More precocious mortlity (10.40 ñ 2.06 days) and , curiouslyy, much lower blood parasitemia were observed in Peptostreptococcus-associated mice than in other gnobiotic mice. The extent of cardiac tissue parasitism decreased in the following order: germfree, B. fragilis-associated, Clostridium-associated and Peptostreptococcus associated animals. The levels of inflammatory reaction decreased in the following order: germfree, Peptostreptococcus-associated , Clostridium-associated, and B. fragilis-associated mice. These results show that the acute phase of experimental infection with T. cruzi was more severe in mice associated with strict anaerobic bacteria when compared with germfree animals. This suggests that a normal intestinal flora may be another factor, in addition to nutritional and genetic factors, responsible for the different susceptibility of organisms of the same species infected with T. cruzi

Effects of testosterone on growth hormone secretion and somatomedin-C generation in prepubertal growth hormone deficient male patients

1. The role of testosterone (T) in growth was evaluated in 11 prepubertal hypopituitary males during two 15-day periods separated by a 4-week interval, i.e., before (PRE-T period) and during T ester treatment (50 mg every 5 days, 3 im doses-T period). 2. T increased growth hormone (GH) secretion, assessed by 4-h rhythm (mean +/- SEM = 1.90 +/- 0.27 vs 1.77 +/- 0.21 ng/ml; P < 0.05) and after a GHRH stimulus (3.42 +/- 0.54 vs 3.08 +/- 0.43 ng/ml; P < 0.05) as compared to the PRE-T period. 3. T also increased basal somatomedin-C (SM-C) levels (0.20 +/- 0.03 vs 0.15 +/- 0.02 U/ml; P < 0.001) and SM-C generation. After GH was administered in 4 im doses (0.01, 0.02, 0.05 and 0.1 U/kg), SM-C levels were 0.31 +/- 0.08 vs 0.24 +/- 0.07 U/ml, P < 0.001. T did not change incremental (absolute minus basal) SM-C levels (0.15 +/- 0.08 vs 0.12 +/- 0.07 U/ml; P > 0.05). 4. The results suggest that T increased plasma SM-C levels by stimulating residual GH secretion in hypopituitary males

Effect of an essential fatty acid deficient diet on experimental infection with Trypanosoma cruzi in germefree and conventional mice

1) To investigate the possible role of essential fatty acid deficiency in host cell/parasite interaction, weanling germefree (GF) and conventional (CV) CFW mice maintained on an essential fatty acid-deficient (-) or a control (+) diet for 110 days were infected with Trypanosoma cruzi. 2) Blood parasitemia indicated that the disease was milder in the animals maintained on the essential fatty acid-deficient diet than in the GF and CV controls (maximum parasitemia: GF+33,300,GF-26,200,CV+17,100 and CV-6,400 trypomastigotes?ml blood). 3) Survival 30 days a after infection was 12% for GF+,28% for GF-,37% for CV+ and 65% for CV- mice. 4) Linoleic and arachidonic acid levels were significantly lower in animals kept on the essential fatty acid-deficient diet (GF-:28.0 ñ 9.3, 23.4 ñ 8.6; CV-:37.6 ñ 5.8, 19.9 ñ 3.6) than in controls (GF+: 164 ñ 48.8, 162.6 ñ 45.8; CV+: 147.1 ñ 26.5, 107.5 ñ 23.6) confirming the deficiency. Before the infection, succinic dehydrogenase levels were higher in liver of all CV mice *4.52 ug phosphate/mg fresh tissue) than in GF mice (0.84 ug phosphate/mg fresh tissue) whereas the opposite was true for 5'-nucleotidase levels in brain and liver, respectively (GF:2.84 and 3.18 ug phosphate/mg fresh tissue: CV:1.25 and 1.54 ug phosphate?mg fresh tissue). The disease was milder in deficient than in control animals in both the GF and CV groups on the basis of parasitemia and survival, indicating that fatty acid-deficient mice are partially protected against Chagas'disease. The mechanism underlying this phenomen requires further investigation

Effect of high sucrose diets on carcass composition in conventional and germ-free mice

1. O efeito da sacarose na dieta sobre a composiçäo da carcassa foi determinado em camundongos convencionais (CV) e isentos de germes (GF) alimentados com raçäo controle e com raçöes contendo 20 a 40% de sacarose. 2. Os camundongos GF na raçäo controle foram mais pesados do que os CV. Contudo, os camundongos CV alimentados com dieta com sacarose foram mais pesados que os GF. 3. Camundongos isentos de germes (GF) alimentados com dieta rica em sacarose mostraram um conteúdo lipídico menor na carcassa em relaçäo aos GF alimentados na raçäo controle e os outros CV. 4. Camundongos convencionais (CV) na dieta rica em sacarose foram mais pesados do que os animais CV na dieta controle. 5. O conteúdo aquoso na carcassa dos camundongos GF na dieta rica em sacarose foi maior do que nos controles GF e nos CV. 6. Esses resultados sugerem um efeito lipidogênico diferente da sacarose alimentar nos camundongos GF e CV

A method for steam-sterilizing semi-solid diets for germ-free mice research

Se describe una ración de maíz semisólida, esterilizada en frascos de vidrio, utilizando un autoclave de tipo hospitalario. Los valores de ganancia de peso, eficacia alimentaria, digestibilidad aparente y diámetro del intestino ciego fueron los mismos para ratones libres de gérmenes, alimentados con esta ración, e con la ración de soya e alfalfa (L-485), ampliamente usada en gnotobiología. La ración de maíz ha sido utilizada con éxito durante un período de ocho años