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Biomedical subjects

J Bitman

Publications and source records attributed to J Bitman.

At least 73 records · Page 4Linked to original sources
PubMed1980

Mastitis: II. Evaluation of antimicrobial amines for use as teat dips.

Recent proposals by the Food and Drug Administration to regulate teat dips as drugs have led to a search for safer teat dip ingredients. Primary, secondary, and tertiary alkyl amines (carbon-10 to -18 chain length) inhibit growth of mastitic bacteria (Streptococcus agalactiae, Streptococcus uberis, Staphylococcus aureus, Escherichi coli, Klebsiella pneumoniae) in a broth tube culture assay. Since carbon-13 compounds were active, a carbon-13 primary (tridecanamine hydrochloride), secondary methyl (N-methyltridecanamine), secondary ethyl (N-ethyltridecanamine), tertiary dimethyl amine (N, N-dimethyltridecanamine), and carbon-12 quaternary amine (N, N, -trimethyldodecaneammonium chloride) were tested for their ability to reduce experimentally applied populations of S. agalactiae or E. coli on the bovine teat surface. The five compounds were compared at concentrations of 100, 500, 1,000, 3,000, 7,000, and 10,000 ppm. Activity was greater against the gram-positive S. agalactiae than against the gram-negative E. coli. The tertiary amine was most active, producing a log reduction of 4 (reduction of bacterial number from 10(6) to 10(2)) at a concentration of 3,000 ppm in the teat dip. The relative order of effectiveness for the amines was: dimethyl tertiary greater than methyl secondary greater than ethyl secondary greater than primary = quaternary. The results suggest that these amines may be useful as potent, effective antibacterial agents for incorporation into teat dips.

Amines↗
PubMed1979

Stimulation of lipid absorption in young rats by cholesterol: early time changes and effects on pentobarbital sleeping time.

Four groups of young male and female rats were fed a chow diet (O), chow plus 10% corn oil (F), chow plus 1% cholesterol (C), or chow plus 1% cholesterol plus 10% corn oil (CF) for 1, 2, 4 and 8 days. After 2 dats, male F, C and CF rats exhibited a shorter anesthesia period (-20 to -30%) when given pentobarbital. By 4 days, male F and C rats had pentobarbital sleeping times (PB-ST) 20% less than O rats. These effects were additive and CF rats had 40% shorter PB-ST. Reduction of PB-ST by cholesterol and corn oil was similar but slightly less in female rats. Liver lipid content doubled in 4 days in CF rats, and liver cholesterol was 4 times than of O rats. These changes and the increases in metabolism of barbiturate suggested changes in liver microsomal enzyme activities. Serum glutamic oxaloacetic and glutamic pyruvic transaminase, two enzymes reflective of liver damage, did not increase after 8 days on C, F or CF diets. Our results suggest that consumption of an animal sterol and a high lipid diet by laboratory rats, normally consuming a diet low in fat (3-4%), increase the ability of the animal to detoxify a barbiturate. Storage of absorbed dietary cholesterol in the liver may represent a major mechanism for maintaining extra hepatic cholesterol homeostasis.

Absorption↗
PubMed1979

Mastitis: I. In vitro antimicrobial activity of alkyl amines against mastitic bacteria.

The activities of branched and straight chain amines (10 to 18 carbons chain length) were compared in inhibiting the growth of five microorganisms that cause about 95% of bovine mastitis. Three gram-positive (Streptococcus agalactiae, Streptococcus uberis, Staphylococcus aureus) and two gram-negative (Escherichia coli, Klebsiella pneumoniae) bacteria were used in a trypticase soy broth tube culture growth assay. Sixty-two compounds were screened at concentrations of 200, 100, 50, 25, 10, 5, and 1 ppm in broth culture to determine the effective minimum inhibitory concentration. Alkyl secondary N-substituted monoethyl [CH3(CH2)nNHCH2CH3] and tertiary N,N-substituted dimethyl [CH3(CH2) nN(CH3)2] amines with chain lengths of 11 to 14 carbon atoms were active against both gram-positive and gram-negative organisms. Antimicrobial activity against gram-positive organisms increased with increasing chain length and carbon-14 to 18 amines were active at 1 to 5 ppm. The carbon-11 to 13 alkyl amines were most active against gram-positive organisms; longer chain amines (more than 14 carbons) were inactive. Branching of the alkyl chain caused a loss of activity against gram-negative but not against gram-positive bacteria. Antimicrobial testing of monoamines, polyamines, and the influence of order substituents were investigated to correlate structure-acitivity relationships.

Amines↗
PubMed1979

Feeding cholesterol and tallow to young calves.

Four groups of eight 4 wk-old Holstein bull calves were fed calf starter diets containing either no additive (control) or added ingredients: 1% cholesterol, 5% tallow, or 1% cholesterol plus 5% tallow. Body weight and size were reduced, and average daily gain was lowered by added 5% tallow. The added dietary tallow and cholesterol increased lipids and cholesterol of plasma by 35 to 40%. The increased intake of fat due to feeding tallow caused both increased fat metabolism and fat excretion as based on chromic oxide estimates of digestibility. Fat digestibility was lowest in animals receiving cholesterol with no added tallow. Organ weights and composition of meat at slaughter at 21 wk of age were not different.

Animal Feed↗
PubMed1978

Liver mixed function oxidases in chickens: induction by polychlorinated biphenyls and lack of induction by DDT.

Microsomal hydroxylase and demethylase activities were compared in livers from White Leghorn cockerels fed polychlorinated biphenyls (PCBs) containing 21 to 68% chlorine, or p,p'-DDT. The higher chlorinated PCBs, Aroclor 1254 and 1268, were potent inducers of hepatic enzyme activity while DDT did not induce these enzymes. Aroclor 1254 was the most potent inducer because feeding 5 ppm increased liver aminopyrine demethylase activity 1.5X but did not affect liver weight. Feeding 50 and 500 ppm of Aroclor 1254 and 1268 increased liver weight and demethylase activity per mg of protein. A differential response in the two enzymes occurred. Only 500 ppm of Aroclor 1268 increased hydroxylase activity. Aroclor 1242 had no effect on liver enzyme concentration but 50 and 500 ppm of Aroclor 1242 increased liver weights and consequently increased total enzyme activity. Our data demonstrated that in the avian species DDT and PCB did not have the same effect on hepatic microsomal enzyme activity.

Aniline Hydroxylase↗
PubMed1978

Necessity of vitamin B12 for growth of rats fed on an odd- or even-carbon-number fat.

1. The effect of vitamin B12 on growth was studied in young male and female rats fed on diets sufficient (+B12) or deficient (-B12) in vitamin B12 containing 30% of the dietary energy as fat, either maize oil (CO) or triundecanoin (TUD). 2. Vitamin B12 deficiency severely depressed growth. After 6 weeks the weight gain of CO(-B12) rats was only 72% of that of CO(+B12) rats and the gain of TUD(-B12) rats was only 47% of TUD(+B12) rats. 3. After fasting 24 or 96 h TUD-fed rats, both +B12 and -B12, had greater glycogen reserves and higher plasma glucose levels than CO-fed rats. 4. It is concluded that vitamin B12 is required for the metabolism and utilization of both an odd-carbon-number medium-chain fat, TUD, and an even-C-number long-chain fat, CO, during growth in rats.

Animals↗
PubMed1978

Embryotoxic effects of polybrominated biphenyls (PBB) in rats.

Pregnant Sprague Dawley rats were given 0, 0.25, 0.5, 1, 5, and 10 mg of a commercial polybrominated biphenyl, FireMaster BP-6 (PBB), in olive oil by gavage each day from days 7 through 15 of pregnancy. Laboratory chow and water were given ad libitum. Treatment with PBB had no significant effect on body weight gain, food and water consumption, and urine production. The mothers were killed on day 20, and the only significant effect observed was an increased liver weight of those given 1, 5, and 10 mg PBB. Spleen, kidney, ovarian, gravid uterine, and perirenal fat pad weights were similar to those of control mothers. PBB had no significant effect on number of live/dead fetuses, crown-rump length or fetal weight. No grossly malformed fetuses were observed in PBB-treated mothers. The effects of PBB transfer from mothers to nursing pups was studied by reciprocal exchange of pups between control mothers and mothers treated with 10 mg PBB. When the pups were 21 days old, they were weaned and fed control chow. The following four combinations of prenatal-postnatal exposure were studied: control-control (C:C); control-PBB (C:PBB); PBB-control (PBB:C); and PBB-PBB. Although the birth weights of pups from PBB-treated mothers were similar to those of the controls, body weights of 60-day-old males exposed prenatally and postnatally (PBB:C, C:PBB, and PBB:PBB) were less (p less than 0.05) than those of the controls (C:C). The weights of the perirenal fat pads of male and female pups exposed to PBB were less (p less than 0.05) than the control. Liver weights, on a body weight basis, were higher in male and female pups exposed to PBB. Vaginal openings were delayed; the percentages of 36-day-old pups with open vaginas were 50 (C:C), 38 (PBB:C), 28 (C:PBB), and 30 (PBB:PBB).

Animals↗
PubMed1977

Milk and tissue lipid composition after feeding cows protected polyunsaturated fat for two years.

The long-term effects of feeding Holstein cows plant lipids protected from microbial hydrogenation in the rumen were studied. Of particular interest were cow health and changes in fatty acid and cholesterol concentrations of milk and meat. Safflower oil-casein or safflower oil-casein treated with formaldehyde to impede microbial attack were fed to two groups of three cows as 10% of the concentrate ration for two lactations. Production of milk fat of cows fed the protected concentrate increased significantly. Linoleic acid of milk fat was twice normal, providing a polyunsaturated milk. Cholesterol of milk or meat did not increase even though cholesterol of blood plasma was higher in both groups fed safflower oil than in control cows. Cardiovascular systems showed no marked abnormalities and no differences that could be due to treatment. All cows maintained normal health and milk production throughout the experiment.

Animals↗
PubMed1977

Feeding polyunsaturated vegetable oils to lactating cows.

Holstein cows fed concentrate:hay diets also were fed for 14 days supplements of soybean oil plus casein, soybean oil protected from ruminal hydrogenation by encapsulation in a casein-formaldehyde matrix, cottonseed oil plus casein, or cottonseed oil protected with casein formaldehyde. The supplements were fed at rates to give a linoleic acid (18:2) intake of 225 g/day. Yields of milk and milk protein were not affected by treatment. Milk 18:2 was not increased by the unprotected soybean oil or cottonseed oil but was increased by protected soybean and cottonseed oil from a control of 2.3 to 5.7% of total milk fat. Milk 18:0 and 18:1 also increased. Compensatory declines were observed in milk 16:0 and 14:0 acids. In fecal fatty acids during the treatment periods, percentage of 18:2 of the total fat decreased and 18:0 markedly increased. These results indicate hydrogenation of the dietary oils in the alimentary tract or a differential absorption. Fecal 16:0 and 14:0 decreased.

Animals↗
PubMed1977

Retention and excretion of polychlorinated biphenyl residues by laying hens.

Commercial polychlorinated biphenyl (PCB) mixtures with 21, 32, 42, 48, 54, and 68% chlorine were fed to caged White Leghorn hens at 20 p.p.m. for nine weeks. The 42, 48, and 54% mixtures were also fed at 2 p.p.m. Residues in egg at nine weeks were 0.7, 2.4, 14.4, 9.3, 11.4, and at 21.5 p.p.m. for the 21, 32, 42, 48, 54, and 68% chlorine PCBs, respectively. Corresponding values in body fat were 24.0, 51.1, 89.3, 90.5, 124.5, and 52.4 p.p.m., respectively. Levels in eggs and body fat of groups fed 2 p.p.m. were approximately one-tenth the levels in the 20 p.p.m. group. After seven weeks of control feed, the values for the 20 p.p.m. groups were 0.7, 1.8, 2.8, 3.0, 7.2, and 1.8 for eggs and 8.1, 22.4, 26.4, 39.8, 91.7, and 43.6 for body fat. Estimated recovery of consumed PCBs increased from 8% to 55% as chlorine increased from 21 to 68%. Residues in excreta was about 10% of intake for all PCBs. Body fat retention was greater than egg elimination for 21 through 48% chlorine PCB, about the same for 54% and much less for the 68% chlorine PCB. The ratio of egg: fat residue in contaminated birds was .084:1.

Adipose Tissue↗
PubMed1976

Vitamin e, cholesterol, and lipids during atherogenesis in rabbits.

Rabbits were fed diets including cholesterol and 10% butterfat to determine whether polyunsaturated butter (9% 18:2) would be less atherogenic than normal saturated butter (3% 18:2) when fed for 12 weeks. The cholesterol diets alone, 0.5% or 2%, produced aortic plaque development, and plasma cholesterol increased 20 times, lipids increased 10 times, and vitamin E increased 5 times. The inclusion of both fat and cholesterol in the diet produced a synergistic effect, doubling these values to 40 times for cholesterol, 20 times for lipids, and 10 times for vitamin E. The higher circulating levels of cholesterol caused increased tissue levels of cholesterol. With 2% cholesterol and fat, liver and aorta cholesterol increased 10 times, heart 4 times, and muscle cholesterol 2 times. The lower 0.5% dietary cholesterol load was successful in limiting the amount of tissue cholesterol increase. Liver, aorta, heart, and muscle levels of cholesterol were only about half the concentration attained when 2% cholesterol was fed. It was concluded that there were no differences in plasma or tissue cholesterol, vitamin E, or atherosclerosis attributable to the polyunsaturated nature of the diet. The 10% butterfat diets alone, whether saturated or unsaturated, did not induce aortic plaques and did not increase blood or tissue cholesterol, lipids, or vitamin E. Our results suggest that the lipid mobilizing effect is mediated by cholesterol, probably by conversion to bile acids and a stimulation in intestinal absorption.

Animals↗