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Biomedical subjects

M J Allison

Publications and source records attributed to M J Allison.

At least 73 records · Page 4Linked to original sources
PubMed1979

Comparison of bacterial populations of the pig cecum and colon based upon enumeration with specific energy sources.

Concentrations of bacteria in the ceca and colons of pigs were measured by determinations of colony counts on rumen fluid-based media in anaerobic roll tubes. With our most complete medium (medium CCA), the mean colony count of cecal samples from 20 pigs was 2.37 X 10(10) +/- 1.0 X 10(10) (+/- standard deviation)/g (wet weight). The mean number of bacteria attached to or associated with cecal epithelial tissues from three pigs on medium CCA was 2.67 X 10(7) +/- 0.81 X 10(7)/cm2 of tissue. The proportions of gut bacterial populations able to use various energy substrates were estimated on the basis of relative colony counts. The following substrates are listed in descending order of their capacity to support growth of cecal bacteria: glucose, starch, cellobiose, xylose, Trypticase, gastric mucin from swine, mannitol, glycerol, and lactate. The effect of diet upon this distribution was not examined. The relative proportions of bacteria from a given population that were able to grow on various selective media were used as population profiles. Comparisons of populations in this way indicated that differences could be detected between (i) populations from the cecum of littermate pigs, (ii) populations from the cecum and colon of the same pig, and (iii) populations in the lumen of the cecum as compared with populations associated with cecal mucosa.

Animals↗
PubMed1979

Automated enzymatic method for the determination of ammonia: application to rumen fluid, gut fluid, and plasma.

The enzymatic method for the determination of ammonia with glutamate dehydrogenase has been adapted to the AutoAnalyzer. The automated method was applicable for NH(3) measurement in sheep rumen samples, swine gut fluid samples, and bovine plasma. Results were compared with those of the Conway diffusion method and the manual enzymatic method. The automated method allows 30 samples per h to be analyzed routinely. Values were comparable with those with the manual method, but lower than those with the Conway diffusion method.

Journal Article↗
PubMed1979

Synthesis of alpha-ketoglutarate by reductive carboxylation of succinate in Veillonella, Selenomonas, and Bacteriodes species.

Evidence for reductive carboxylation of succinate to synthesize alpha-ketoglutarate was sought in anaerobic heterotrophs from the rumen and from other anaerobic habitats. Cultures were grown in media containing unlabeled energy substrates plus [14C]succinate, and synthesis of cellular glutamate with a much higher specific activity than that of cellular asparate was taken as evidence for alpha-ketoglutarate synthase activity. Our results indicate alpha-ketoglutarate synthase functions in Selenomonas ruminantium, Veillonella alcalescens, Bacteroides fragilis, Bacteroides vulgatus, Bacteroides uniformis, Bacteroides distasonis, and Bacteroides multiacidus. Evidence for this carboxylation was not found in strains representative of 10 other species.

Amino Acids↗
PubMed1979

Alterations of host defenses paralleling cholesterol-induced atherogenesis. I. Interactions of prolonged experimental hypercholesterolemia and infections.

Cholesterol may interfere with normal repair processes in the arterial wall. It is also possible that this same action occurs during inflammation and repair throughout the body. This hypothesis was tested by giving intravenous injections of Bacteroides fragilis, a bacterium that is innocuous for normal rabbits even when multiple large doses are given. Almost all cholesterol-fed rabbits developed significant pleuropulmonary infections with complications that included vasculitis, thrombosis, extrapulmonary infections, and significant mortality. More than half of this group was culturally positive for B. fragilis at the time of autopsy while cultures from control animals were sterile. These results suggest that cholesterol may interfere with the functions of those cells involved in host defense.

Animals↗
PubMed1979

Alterations of host defenses paralleling cholesterol-induced atherogenesis. II. Immunologic studies of rabbits.

Cholesterol-fed rabbits are more susceptible to experimental infections than similar animals given a normal diet. Multiple tests were employed to estimate functions of reticuloendothelial (RE) phagocytosis, lymphocyte activity, polymorphonuclear (PMN) and macrophage chemotaxis, phagocytosis, and bactericidal activity, as well as enzymatic activity of the macrophages. RE phagocytosis was unchanged in the cholesterol-fed animals. However, most functions of the isolated PMNs and macrophages were significantly reduced. Three of five dehydrogenases and phosphatase were lower in activity from cells obtained from cholesterol-fed rabbits than from controls. Conversely, both B and T lymphocyte activities were significantly higher among the cholesterol-fed animals. These metabolic and functional alterations of cells from cholesterol-fed rabbits may explain the increased susceptibility to infection among these animals. The enzymatic changes found in leukocytes may correlate with those changes in arteries observed during atherogenesis, thereby providing a new prognostic test for risk of atherosclerosis.

Animals↗
PubMed1978

Cholelithiasis and cholecystitis in pre-Columbian Chileans.

Two cases of gallbladder disease found in Chilean mummies are presented. The cholesterol gallstones in these cases produced in one individual a localized peritonitis and in the other a probable duct obstruction. No cases of this disease have been seen in Peruvian mummies while in Chile it seems quite common, suggesting some environmental factor in the etiology.

Chile↗
PubMed1978

ABO blood groups in Chilean and Peruvian mummies. II. Results of agglutination-inhibition technique.

ABO blood groups of Peruvian and Chilean mummies were determined with the agglutination-inhibition method. In Peru all ABO blood groups were found in the period from 3000 B.C. to 1400 A.D.; from this period to 1650 only A and O were seen. In Chile no B or AB was noted either in pre-Columbian or Colonial mummies. This confirms the archeological concept that the Chilean Indian was culturally as well as genetically different from the Peruvian Indian. Further studies using other genetic markers are in order, as well as changing certain preconceived notions on blood groups of American Indians.

ABO Blood-Group System↗
PubMed1978

Production of branched-chain volatile fatty acids by certain anaerobic bacteria.

Net production of isobutyric acid, isovaleric acid, and 2-methylbutyric acid by cultures of Bacteroides ruminicola and Megasphaera elsdenii on media that contained Trypticase or casein hydrolysate continued (up to 5 days) after growth had ceased. Only trace quantities of these acids were produced in a medium that contained a mixture of amino acids that did not include the branched-chain amino acids. M. elsdenii produced increased quantities of the branched-chain fatty acids in a medium that contained Trypticase when glucose was reduced or eliminated from the culture medium. However, B. ruminicola produced increased quantities of branched-chain fatty acids and of phenylacetic acid from Trypticase when glucose was supplied at 3 mg/ml rather than at 1 mg/ml. Single strains of Streptococcus bovis, Selenomonas ruminantium, Bacteroides amylophilus, and Butyrivibrio fibrisolvens did not produce branched-chain fatty acids.

Anaerobiosis↗
PubMed1978

Laboratory identification and epidemiology of streptococcal hospital isolates.

A total of 343 streptococcal strains were identified to species on the basis of the progressive method of bacterial identification as advocated by Cowan & Steel's Manual for the Identification of Medical Bacteria. Comparative studies were also performed with these strains to determine the accuracy and feasibility of using various types of blood, differential media, and biochemical tests in conjunction with the progressive method of identification. The streptococcal species were then correlated with the type of specimen, sex, and age of hospitalized patients to obtain some insight into the epidemiology of hospital streptococcal isolates.

Adolescent↗
PubMed1977

A comparative study on the dental health status of five precolumbian Peruvian cultures.

In a survey of dental health status of ancient Southern Peru, 101 skeletal remains were studied from five cultures: Paracas, Nazca, Tiahuanaco, Ica, and Inca. The Paracas and Ica cultures exhibited more missing antemortem teeth per mandible than the other cultures. Frequency of missing one or more third molars was less than expected and not as high as reported in peoples of Mongoloid heritage. The Paracas, Ica and Nazca, "coastal" cultures had a higher caries incidence than the "inland" cultures. Whether this relates to some difference in diet or water supply remains unresolved and warrants further investigation. Moderate attrition was noted in all the Precolumbian cultures but pulpal involvement was not observed. Osteitis, noted in all the cultures, was more pronounced in the Nazca, Paracas and Ica cultures. There appeared to be a direct relationship between caries involvement and the number of missing antemortem teeth to osteitis. Calculus was heavier in the Paracas and Ica cultures. In addition, the Paracas culture exhibited a dark brown stain on the teeth which may imply some difference between the cultures in either the food, water or social habits.

Bone Resorption↗
PubMed1976

ABO blood groups in Peruvian mummies. I. An evaluation of techniques.

Blood groups of Peruvian mummies of known origin were determined by three different methods: agglutination-inhibition, induction of antibody production and mixed cell agglutination. The three techniques gave identical results, but the last two were useful in establishing the presence of H (O) antigen, while the first technique would not. The results indicate the presence of A, B, AB and O blood groups in America prior to known European contact. This suggests the need for a revision of concepts of blood groups in the American Indian.

ABO Blood-Group System↗