Frequency of infection by Neospora caninum in wild rodents associated with dairy farms in Aguascalientes, Mexico.

The purpose of this study was to detect the presence of Neospora caninum in tissues from wild rodents associated with dairy farms in Aguascalientes, Mexico. Individuals from Mus musculus, Rattus novergicus and Spermophilus variegatus were caught in dairy farms with history of positive status to N. caninum. A total of 33 rodents were caught from which samples were taken of brain, spinal cord, liver and heart and were tested with nested PCR and Immunohistochemistry (IHC). Results obtained with PCR showed that M. musculus had 77% (10/13) positive samples to N. caninum, S. variegatus had 71% (10/14) and R. novergicus had 50% (3/6). The results obtained with IHC showed that 15% (2/13) of M. musculus individuals were positive, while 43% (6/14) of S. variegatus and 33% (2/6) R. novergicus were also positive. This is the first report of the presence of N. caninum in S. variegatus.

Effects of aflatoxin chronic intoxication in renal function of laying hens.

Aflatoxins (AF) have a high impact in both human and animal health, causing significant economic losses in the poultry industry, especially by diminution of avian growth, feed efficiency, and product quality. Aflatoxins affect the whole organism, particularly liver and kidney. The objective of this study was to evaluate renal function alterations in laying hens during chronic AF ingestion. Randomly, 84 Leghorn Hy-Line laying hens (13 wk old) were assigned into 4 experimental groups (n = 21): 0.0, 0.5, 1.0, and 1.5 mg of AF/kg of feed. The AF (B(1), B(2), G(1), and G(2)) was obtained from 2 toxicogenic local strains of Aspergillus flavus grown in corn grains; the grain was sterilized, ground, and added to basal diets to achieve the selected AF concentrations. Hens ingested, during 17 and 42 wk, feed contaminated with AF. Data were analyzed in a 4 x 2 factorial arrangement. Hens were anesthetized, ureteral urine samples were collected, and arterial blood samples were taken. The renal functional tests were evaluated by spectrophotometric and flame photometric methods, including a) Na, K, Ca, and phosphate fractional excretions; b) renal hemodynamic studies, glomerular filtration rate and renal plasma flow by inulin and p-aminohippurate clearances, respectively; and c) identification of macroscopic and histopathologic lesions. The hens intoxicated at all levels of AF showed significant (P < 0.05) increases in Ca, Na, and phosphate fraction excretions. Sodium and phosphates were excreted in a pattern of response time-dose. However, glomerular filtration rate exhibited a significant reduction (P < 0.05). The K fractional excretion and renal plasma flow remained unchanged. These results suggest that AF chronic ingestion affects renal functions of laying hens and induces Ca(++), (-3)PO(4), and Na(+) losses, which are of great concern to the poultry industry.

Survey of Neospora caninum infection by nested PCR in aborted fetuses from dairy farms in Aguascalientes, Mexico.

The aim of this study was to determine by nested PCR probe the presence of Neospora caninum in fetal brain tissue from aborted dairy fetuses in Aguascalientes, a state in the central part of Mexico. Forty-four fetal brains from eight dairy farms were analyzed using single tube nested PCR probe with primers NF1, NS2, NR1 and SR1, with histopathology as the reference technique. From the 44 bovine fetuses studied, 35 (80%) were diagnosed as being infected by N. caninum using PCR probe and 20 (45%) were considered positive by histopathology, because they had lesions suggestive of bovine neosporosis. Fair agreement was observed (31%) between both probes. The age of aborting cows ranged from 1.6 to 2.9-year-old in 17 (49%) of the positive cases diagnosed by PCR. Gestational ages of aborted fetuses ranged from <3 to 9 months, with average of 5.6 months, and no statistical significant difference was observed when ages of infected and no infected fetuses were compared (P > 0.05). The frequency of N. caninum positive cases observed could be considered to be higher than other areas of Mexico and other countries.

Efficacy of N-acetylcysteine to reduce the effects of aflatoxin B1 intoxication in broiler chickens.

N-acetylcysteine (NAC) has been used safely in humans and in other mammals as an antidote against several toxic and carcinogenic agents, including aflatoxin B1 (AFB1). The aim of this study was to evaluate the capability of dietary supplementation with NAC to ameliorate the effects of subacute intoxication with AFB1 in broiler chickens. One hundred twenty male Hubbard 1-d-old chickens were allocated into one of four dietary treatments: 1) control group without treatment, 2) purified AFB1 added to diet (3 mg/kg of feed) for 21 d, 3) NAC (800 mg/kg BW, daily), or 4) AFB1 plus NAC at the same doses as Groups 2 and 3. Broilers treated with AFB1 plus NAC were shown to be partially protected against deleterious effects on BW (57.8%), daily weight gain (49.1%), feed conversion index (21.4%), plasma and hepatic total protein concentration (45.2, 66.7%), plasma alanine aminotransferase (67.4%), hepatic glutathione-S-transferase (18.8%), and reduced glutathione liver concentration (75.0%). In addition, they showed less intense liver fading, friable texture, and microvesicular steatosis. In the kidney, thickening of glomerular basement membrane was also less severe in NAC+AFB1-treated chickens than in AFB1-treated chickens. Our results suggest that NAC provided protection against negative effects on performance, liver and renal damage, and biochemical alterations induced by AFB1 in broiler chickens. Effects of NAC alone on chick performance were also evaluated. Addition of NAC to diet (800 mg/kg BW) did not negatively affect feed consumption, conversion index, or serum chemistry and did not induce structural changes in the liver or kidney.

Effects of aflatoxin B(1) on the liver and kidney of broiler chickens during development.

Aflatoxin B(1) (AFB(1)) negatively affects chicken (Gallus domesticus) growth. This effect is more severe during development. We studied the influence of age on the toxic effects of AFB(1) on plasma, renal and hepatic enzymes, under two protocols, in adult and in developing Arbor-Acres chickens. Protocol A: 100 male 4-week-old chickens (640 g), received AFB(1), 0.5, 1.0, or 2.0 microg/g of feed (daily p.o.), a fourth group received an aflatoxin-free diet. Five birds/group were slaughtered at 7, 14, 21 and 28 days of treatment. Body, hepatic and renal weights, succinate-dehydrogenase (SDH) and glutamate-dehydrogenase (GluDH) in plasma and liver were measured. Hepatic SDH and GluDH decreased (P<0.05). Protocol B: two groups of 24 male 1-week-old chickens (106 g) received either aflatoxin-free feed (n=24) or AFB(1) feed (2.0 microg/g). At days 7, 14, 21 and 28, the same parameters of Protocol A were measured. AFB(1) markedly reduced body weight gain (20-30%), plasma proteins, albumin, renal and hepatic protein content (P<0.05) and increased absolute and relative weights of the kidney (P<0.05). SDH and GluDH were reduced (P<0.05), while total renal gamma-glutamyltranspeptidase (GGT) increased (P<0.05). Results suggest that serum proteins, SDH and GluDH are sensitive early indicators of this toxicity that was more severe in developing chickens. Decrease in serum albumin might be used as an early and suitable indicator of the deleterious effect of this mycotoxin in developing chickens.

[Social sciences, preventive medicine and medical education in Venezuela]. / Ciencias sociales, medicina preventiva y formación médica, Venezuela.

The subject of this paper is the importance of preventive and social medicine in medical education; it presents a study based on an examination of the function of these subjects with particular reference to the Luís Razetti School of Medicine. The authors assert that, in the present state of medical education, the new physician is unprepared to deal with the country's real needs. The purposes of the medical school are to turn out personnel who can mesh effectively into the operations of health systems, to do research and identify health problems of the community, to participate in the framing of health policies, and to train teaching staff who are socially aware and thus in tune with the country's health policies. Despite much discussion and study of the subject, little has been done in practice. The authors state their views and assert that the universities must draw up the curricula for their medical schools with an eye to the needs of the countries and with emphasis on preventive and social medicine.

Ciencias sociales, medicina preventiva y formación médica, Venezuela / Social sciences, preventive medicine and medical education in Venezuela

The subject of this paper is the importance of preventive and social medicine in medical education; it presents a study based on an examination of the function of these subjects with particular reference to the Luís Razetti School of Medicine. The authors assert that, in the present state of medical education, the new physician is unprepared to deal with the country's real needs. The purposes of the medical school are to turn out personnel who can mesh effectively into the operations of health systems, to do research and identify health problems of the community, to participate in the framing of health policies, and to train teaching staff who are socially aware and thus in tune with the country's health policies. Despite much discussion and study of the subject, little has been done in practice. The authors state their views and assert that the universities must draw up the curricula for their medical schools with an eye to the needs of the countries and with emphasis on preventive and social medicine (Au)