Search PubMed⌕ Search

Biomedical subjects

A M Allen

Publications and source records attributed to A M Allen.

At least 109 records · Page 6Linked to original sources
PubMed1976

Tyzzer's disease in free-living cottontail rabbits (Sylvilagus floridanus) in Maryland.

Complement-fixing (CF) antibody to Bacillus piliformis antigen was found in 9 of 14 (64%) serum samples obtained from cottontail rabbits (Sylvilagus floridanus) killed in the wild. CF antibody was not present in the serum of 8 cottontail rabbits trapped as juveniles in the same geographic areas and held in captivity for 4 years. Sero-negative cottontail rabbits died acutely with lesions typical of Tyzzer's disease following the intragastric administration of 10(3.8) ELD50 of B. piliformis spores. The possible influence of Tyzzer's disease upon the cyclic population pattern of cottontail rabbits in the wild is discussed. A hypothesis is presented that B. piliformis spores passed in the feces of diseased wild animals could contaminate pastures, hay and grain, and thereby serve as sources of infection to other animals.

Animals↗
PubMed1975

Epidemic hepatitis B: a sustained outbreak in a large military population.

A sustained outbreak of viral hepatitis occurred at an Army base in Texas between January 1971 and June 1973. Seven hundred ninety-two admissions but no deaths were recorded in a military population of 35,000. Cases were sporadic, with highest attack rates in low-ranking soldiers with disciplinary problems. Twenty-nine per cent of patients had histories of intravenous drug use within six months prior to hospitalization; most of the rest had close personal contact with jaundiced persons. Of 505 patients tested, 31% were seropositive for hepatitis B antigen (HBSAg) by counterelectrophoresis. Comparison of 38 hepatitis patients (cases) to 34 orthopedic patients (controls) revealed marked differences in rates of exposure to jaundiced persons are shared needles. Sixteen (94%) of 17 antigenemic cases tested were of subtype ayw. Seven (78%) of nine NBSAg-negative cases tested were antibody (anti-HBS) positive three months later.

Adult↗
PubMed1975

Hepatitis B antigen in saliva, urine, and stool.

A survey of hepatitis B patients, asymptomatic hepatitis B antigen (HBsAg) carriers, and control subjects was conducted to determine the relationship between antigenemia and antigen excretion in saliva, urine, and stool. Radioimmunoassay was used to detect HBsAg. Specificity-confirmed HBsAg was detected in the saliva of 6 (30%) of 20 antigenemic patients, 1 (5%) of 20 nonantigenemic patients, 14 (34%) of 41 carriers, and 0 of 112 controls. HBsAg was detected in urine only after 100-fold concentration of first-morning specimens. Specificity-confirmed HBsAg was present in the urine of 7 (16%) of 43 carriers; unconfirmed HBsAg was found in the urine of 5 (13%) of 38 patients and 5 (5%) of 112 controls. Unconfirmed HBsAg was detected in concentrated stool specimens from 5 (46%) of 11 patients and 3 of 8 carriers and controls. Longitudinally collected specimens from antigenemic subjects showed no consistent patterns of antigen excretion.

Carrier State↗
PubMed1974

Bacterial pyodermas.

Explore the source record for details and available documents.

Administration, Topical↗
PubMed1974

Specificity and sensitivity of radioimmunoassay for hepatitis B antigen.

Sera from a survey of 6,026 people were tested for hepatitis B surface antigen by using radioimmunoassay and counterelectrophoresis. Forty-eight sera (0.79%) were positive by counterelectrophoresis and 152 sera (2.52%) were positive by radioimmunoassay, using the most liberal of the recommended criteria for positivity (i.e., counts 3 standard deviations above the mean). Absorption tests performed on the 152 radioimmunoassay-positive sera showed that 10 (6.6%) were false-positive reactions to guinea pig protein, 74 (48.6%) were due to false-positive reaction(s) with other protein(s) in the test system, and 68 (44.8%) were true positives. There was a strong correlation between the degree of elevation of radioactive counts and the proportions of sera that were true positives; all 49 sera with counts >50 standard deviation units above the mean were true positives, but only 19 (18.4%) of the 103 sera with counts <50 standard deviation units were true positives. A few sera with high counts required absorption with type-specific (type D) antisera. The following conclusions were reached from this study: (i) absorption tests should be run on all radioimmunoassay-positive, counterelectrophoresis-negative sera; (ii) most (about 90%) false positives are not due to anti-guinea-pig protein reactions; and (iii) radioimmunoassay, in combination with absorption tests, yields a modest increase (about 35%) in detection of true positives over use of counterelectrophoresis alone.

Animals↗
PubMed1974

Skin infections in eastern Panama. Survey of two representative communities.

A skin infection survey of 1,084 people was carried out in two jungle villages in eastern Panama. Bacterial pyoderma was the most prevalent infection, affecting 25% of boys, 15% of girls, and 11% of those over 10 years of age. Streptococcus pyogenes and Staphylococcus aureus were recovered from 84% of pyodermas cultured. Nearly 60% of the cutaneous staphylococcal isolates were resistant to penicillin. Hippelates flies were seen feeding on purulent skin lesions and may have been important in transmission. Scabies, ringworm, candidiasis, and cutaneous leishmaniasis were in comparison with pyoderma involving less than 1% of the population each. All of the ringworm infections were caused by Trichophyton rubrum.

Adolescent↗