Non-invasive testing reveals a high prevalence of simian T-lymphotropic virus type 1 antibodies in wild adult chimpanzees of the Taï National Park, Côte d'Ivoire.

Little information is available on the prevalence of retrovirus infections in populations of non-human primates living in their natural habitats. To gain such information, methods were developed to detect antibodies to simian T-lymphotropic virus type 1 (STLV-1) in urine from wild chimpanzees. Samples from more than 74 chimpanzees living in three communities in the Taï National Park, Côte d'Ivoire, were analysed. The prevalence of STLV-1 antibodies in adults and adolescents was significantly higher (35/49, 71.4 %) than that in infant and juvenile chimpanzees (3/31, 9.7 %).

Effects of dietary electrolyte balance on the chemistry of blood and urine in lactating sows and sow litter performance.

One hundred fifty-three sows (average parity of 2.2) were used to determine the effects of dietary electrolyte balance (calculated as mEq/kg of diet for Na + K - Cl) on sows and their litters during lactation. The sows were fed corn-soybean meal-based diets (1.0% lysine, 1.0% valine, 0.95% Ca, and 0.80% P; as-fed basis) starting on d 109 of gestation and throughout the 21-d lactation experiment. Dietary electrolyte balance (dEB) was 0, 100, 200, 350, and 500 mEq/kg (as-fed basis), well above and below the dEB of 185 mEq/kg found in a simple corn-soybean meal-based lactation diet. To achieve the desired dEB, diets had the following: 1) 1.8% HCl (6 N) and 1.06% CaCl2, 2) 1.0% CaCl2, 3) 0.04% NaHCO3, 4) 1.29% NaHCO3, and 5) 2.54% NaHCO3 (as-fed basis). Increasing dEB increased blood pH (linear and quadratic effects, P < 0.001), partial pressure of carbon dioxide (linear effect, P < 0.001), HCO3- concentration (linear and quadratic effects, P < 0.001), and blood base excess (linear and quadratic effects, P < 0.001). However, increased dEB resulted in lower blood concentrations of K (linear and quadratic effects, P < 0.04), Cl (linear and quadratic effects, P < 0.001), and ionized Ca (linear and quadratic effects, P < 0.001). Changing dEB did not affect ADFI; water usage, litter weight gain; sow weight change; sow backfat change; percentages of CP, lactose, and fat in the milk; percentage of sows returning to estrus; days to estrus; and number of pigs born alive in the subsequent litter (P = 0.06). However, piglet survivability to d 10 and overall was greatest with the lower dEB treatments (linear effect, P < 0.05). The pH (linear and quadratic effects, P < 0.001) and colony forming units of total bacteria (linear effect, P < 0.03) in the urine increased as dEB of the diet was increased. In conclusion, dEB had pronounced effects on the physiological status of sows and decreasing dEB below that in a simple corn-soybean meal-based diet decreased bacterial counts in the urine and increased piglet survivability. However, milk composition, sow and litter weights at weaning, and subsequent rebreeding performance of the sows were not affected by dEB.

Comparative metabolism of [14C]benzene to excretable products and bioactivation to DNA-binding derivatives in maternal and neonatal mice.

Lactating adult female mice treated with a single dose of 880 mg/kg i.p. [14C]benzene, and their 2-day-old sucklings similarly treated or nursed by their treated dams were compared in terms of their ability to metabolize benzene to urinary products or reactive intermediates as assessed by covalently-bound benzene derivatives in whole blood or liver DNA. Six metabolite fractions were identified in the urine of sucklings by high performance liquid chromatographic (HPLC) analysis at 5 h following intraperitoneal (direct) treatment with benzene. Three of the metabolite fractions co-chromatographed with authentic phenol, phenyl glucuronide, and muconic acid, and contributed 11, 6.9 and 0.6%, respectively, to the total urinary benzene metabolites. Two of the fractions were unidentified. The sixth and most polar fraction consisted of multiple metabolites, 21% of which were conjugates, and accounted for 72% of the total urinary metabolites. A similar metabolite profile was observed in 24-h urine samples from treated dams with the exception that one of the unidentified fractions in the sucklings was absent and levels of the metabolites were quantitatively higher than those observed in sucklings 5 h following their treatment with benzene. Furthermore, 78% of the most polar fraction from the dams consisted of conjugates compared with 21% of that from the sucklings. The metabolite pattern in urine of sucklings nursed by treated dams was qualitatively similar to, but quantitatively different from the pattern in treated dams. Five hours following intraperitoneal treatment with benzene, covalent binding of the compound to DNA (expressed as pmol benzene equivalents/mg DNA) in sucklings was slightly higher in whole blood (1.15+/-0.07) than in liver (0.77+/-0.07), whereas in the dam, it was slightly lower in whole blood (0.88+/-0.48) than in liver (1.63+/-0.61). Twenty four hours following benzene exposure in sucklings of benzene-treated dams, DNA binding by the compound in whole blood (3.85+/-1.05) and liver (0.11+/-0.03) was higher and lower, respectively than the binding observed in benzene-injected sucklings 5 h following the injection. Our results show that excretable as well as reactive metabolites of benzene are formed substantially by the neonatal mouse, and that the extent of bioactivation of the compound is comparable in the adult and the suckling mouse. The results show also that sucklings of benzene-exposed mothers are exposed to substantial levels of the compound and are potentially susceptible to its toxic effects.

Urinary diagnostic indices in calves.

OBJECTIVE: To establish reference values for urinary diagnostic indices in healthy calves from birth to 90 days of age. DESIGN: Prospective field trial. ANIMALS: 12 Holstein heifer calves. PROCEDURE: Urine and serum samples were collected daily for the first 5 days after birth, then weekly until calves were 90 days old. Urine:serum creatinine ratio, urine:serum urea nitrogen ratio, urine:serum osmolality ratio, fractional clearances of sodium and inorganic phosphate, and urine gamma-glutamyltransferase activity were measured. Data were grouped by age of calves at the time of sample collection: 1 to 5 days old (neonatal period), 7 to 27 days old (suckling period), and 28 to 90 days old (weanling period). RESULTS: Mean urine:serum creatinine, urea nitrogen, and osmolality ratios were significantly higher during the weanling period than during the other 2 periods. There were no significant differences in mean fractional clearances of sodium among age periods. CLINICAL IMPLICATIONS: Urinary diagnostic indices calculated for these healthy calves may be used as reference values for early recognition of renal damage or renal failure.

Metabolism of the food-derived carcinogen 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine by lactating Fischer 344 rats and their nursing pups.

BACKGROUND: An important class of dietary mutagens and carcinogens are the heterocyclic arylamine compounds that have been identified in a variety of cooked, protein-containing foods. Among these heterocyclic amines, 2-amino-1-methyl-6-phenylimidazo[4,5-b]-pyridine (PhIP) is potentially the most important carcinogen for human cancer risk. We have recently observed that PhIP-derived radioactivity is excreted into the breast milk of lactating rats administered [3H]PhIP. PURPOSE: To better assess the significance of breast milk as a route of exposure of the newborn to dietary heterocyclic amines, we examined the metabolites of PhIP in breast milk and in urine of nursing pups. METHODS: Lactating Fischer 344 rats with 5-day-old pups were given a single oral dose of 10 mg/kg of [3H]PhIP. We collected milk from the dams and urine from the pups and then analyzed the samples for metabolites of PhIP, using high-pressure liquid chromatography (HPLC). PhIP-DNA adduct levels in the tissues of the pups were determined by 32P-postlabeling analysis. RESULTS: Three radioactive peaks were observed by HPLC separation of milk samples: an unidentified early eluting peak, 4'-hydroxy-PhIP, and PhIP. Four metabolites and the parent compound were found in urine of the pups nursed by dams given radiolabeled PhIP: PhIP-4'-O-glucuronide, PhIP-4'-sulfate, 4'-hydroxy-PhIP, and N2-hydroxy-PhIP-N3-glucuronide. 4'-Hydroxy-PhIP and its conjugates contributed approximately 60% of the radioactivity found in the urine. By 32P-postlabeling analysis, PhIP-DNA adducts were detected in spleen, lung, heart, kidney, liver, and stomach of pups at mean levels ranging from 0.06 to 0.55 adducts/10(7) nucleotides. CONCLUSIONS: The large percentage of 4-hydroxy-PhIP and its conjugates in the urine indicates that 5-day-old pups detoxify PhIP and further metabolize 4'-hydroxy-PhIP obtained from the breast milk. The presence of the glucuronide conjugate of N-hydroxy-PhIP in the urine of pups and the lack of detectable conjugate or N-hydroxylamine itself in breast milk suggest that PhIP from breast milk undergoes metabolic activation via N-hydroxylation in 5-day-old rat pups. This conclusion was further supported by the observation that hepatic S9 fractions from the pups activated PhIP to a mutagen in the Ames Salmonella mutagenicity assay and by the presence of PhIP-DNA adducts in the tissues of the pups. IMPLICATIONS: The findings reported here may have carcinogenic and toxicologic implications for the offspring of women who breast-feed and consume a diet rich in cooked meat.

An evaluation with piglets of bovine milk, hydrolyzed bovine milk, and isolated soybean proteins included in infant milk formulas. I. Effect on organ development, digestive enzyme activities, and amino acid digestibility.

A study, using the piglet as a model for the human infant, was undertaken to determine the effect of the protein source of a milk formula on organ development, the activity of digestive enzymes, and the absorption of amino acids as measured at the terminal ileum and over the entire digestive tract. Three isocaloric liquid milk formulas containing equal amounts of either intact bovine milk, hydrolyzed bovine milk, or isolated soybean protein as the sole source of this nutrient and with equal levels of fat and carbohydrate were each given to six 14-day-old piglets over a 19-day period in a manner that mimicked human infant feeding practice. Following a 6-day metabolism study, the piglets were killed, their organs removed, and samples of digesta collected. The protein source of the milk-based formula did not affect (p greater than 0.05) the weight/unit body weight of the small intestine, large intestine, liver, or pancreas, but the relative weight of the kidneys was lower (p less than 0.05) for animals fed the intact bovine milk-based formula and that of the stomach was higher (p less than 0.01) for piglets receiving the isolated soybean formula. The activities of pepsin, intestinal trypsin and chymotrypsin and pancreatic chymotrypsin were not influenced (p greater than 0.05) by protein source, but piglets receiving the bovine milk-based formula had a lower level of activity (p less than 0.01) for pancreatic trypsin. The apparent ileal and fecal absorption of nitrogen was similar for the three milk-based formulas, the overall mean ileal absorption of nitrogen (+/- SE) being 89.0% (+/- 1.44). Excluding cystine, where ileal absorption was relatively lower (p less than 0.05) with the isolated soybean formula (86.7%) compared with the intact bovine milk (91.5%), protein source had little effect on the apparent absorption of essential amino acids. It was concluded that the replacement of intact cow's milk protein in human infant formulas by either hydrolyzed cow's milk or isolated soybean protein is unlikely to cause any major disturbance in the digestive process.

Homeostatic control of manganese excretion in the neonatal rat.

Previous studies in neonatal and suckling animals showed that immature animals have a greatly diminished capacity to excrete manganese and therefore were considered to be unable to regulate tissue manganese concentrations. In contrast, the present studies indicate that suckling rats have the capacity to excrete excess manganese at rates nearly comparable to those of adults. Eight- to 10-day-old rats given a tracer dose of 54MnCl2 (essentially carrier free), either via gavage or by intraperitoneal injection showed little elimination of the 54Mn until the 18-19th day of life, when there was an abrupt increase in the rate of the metal's excretion. However, when manganese was given in doses of 1 and 10 mg/kg, the young animals excreted from 30-70% of the dose in only 4 days, at which time a new rate of excretion was achieved. This enhanced rate of excretion remained constant until the 18-19th day of life, when it was again accelerated. Biliary excretion of manganese, the primary route for the elimination of the metal, was only 30-60% lower in 14-day-old rats compared with adults at doses ranging from tracer to 10 mg 54Mn/kg. For both the 14-day-old and adult rats, an apparent biliary transport maximum was reached at a dose of 10 mg Mn/kg. These studies indicate that the excretory pathways for manganese are well developed in the neonatal rat. The avid retention of tracer quantities of manganese by the neonate may be a consequence of the scarcity of this essential trace metal in its diet.