Search PubMed⌕ Search

Biomedical subjects

A M Allen

Publications and source records attributed to A M Allen.

At least 91 records · Page 5Linked to original sources
PubMed1980

Subclinical scurvy in the guinea pig.

Twenty-eight guinea pigs from nine episodes of subclinical scurvy had diarrhea, weight loss and dehydration. The classical signs of scurvy were not seen. Microscopically the epiphyses were attenutated and irregular. The amount of osteoid was less than normal. Many guinea pigs had acute enteritis. In some there were many hemosiderin-laden macrophages in the intestinal lamina propria. All episodes were associated with either autoclaving food without adequate supplementation or other inadequate feed management practices.

Animals↗
PubMed1979

Allergic hypersensitivity to neomycin. Relationship between patch test reactions and 'use' tests.

The prevalence of neomycin patch test sensitivity in the general population is approximately 1%. We describe the relationship between positive neomycin patch tests and clinical "use tests" with two antibiotic combinations (Neosporin G cream and Neosporin ointment). The neomycin use test was positive in seven of eight subjects with a strongly positive patch test, and in two of four subjects with a weakly positive patch test. A positive use test usually occurred earlier and was always more intense with the cream base. The use test reactions were usually mild even with continued application of the antigen. Use tests with commercial products may be helpful in evaluating the clinical relevance of positive patch tests.

Drug Hypersensitivity↗
PubMed1979

Allergic contact hypersensitivity to nickel, neomycin, ethylenediamine, and benzocaine. Relationships between age, sex, history of exposure, and reactivity to standard patch tests and use tests in a general population.

A study population of 1,158 paid adult volunteers was obtained. Prior to patch testing, a history of previous exposure to four allergens also was obtained. Prevalence of positive reactions to patch tests was nickel, 5.8%; neomycin, 1.1%; ethylenediamine, 0.43%; and benzocaine, 0.17%. Nine percent of women reacted to nickel compared with 0.9% of men. There was a strong correlation of nickel sensitivity with a history of pierced ears, earlobe rash, and jewelry rash. Ten of 12 neomycin-positive subjects used neomycin for one week or longer on an inflammatory dermatosis, compared with six of 36 age-, race-, and sex-matched controls. By history, 85% were exposed to benzocaine, 48% to neomycin, and 15% to Mycolog (ethylenediamine). Of 127 patients referred to clinics for evaluation of contact dermatitis, 11% yielded positive tests to nickel, 6.3% to neomycin, 3.1% to ethylenediamine, and 1.6% to benzocaine. Data obtained from testing contact dermatitis patients are not applicable to the general population.

Adult↗
PubMed1978

Occlusion, carbon dioxide, and fungal skin infections.

Occlusion of the skin renders it susceptible to acute fungal skin infections (dermatophytosis and candidiasis). Occlusion also raised carbon-dioxide (CO2) tensions at the skin's surface. Comparable CO2 tnesions have a pronounced effect on the morphology and metabolism of dermatophytes in vitro. It is postulated that dermatophyte conida and hyphae produce infective units under conditions of raised CO2 tensions, and that occlusion of the skin produces the concentrations of CO2 required for the conversion. Fungal skin infections might be prevented or controlled by interference with the action of CO2 or by prevention of its accumulation under wet, occlusive clothing.

Acute Disease↗
PubMed1978

Effect of occlusion on Trichophyton mentagrophytes infections in guinea pigs.

The effect of occlusion and griseofulvin on the duration and severity of acute dermatophytosis was assessed in guinea pigs. Sixty guinea pigs given standard Trichophyton mentagrophytes infections were divided into 5 groups: (A) control, (B) intermittent wet occlusion, (C) continuous-wet occlusion, (D) griseofulvin, (E) griseofulvin-continuous-wet occlusion. Lesions were largest in the control group, smallest in the griseofulvin-continuous-occlusion group, and of intermediate area in the other groups. The degree of inflammation and alopecia was not affected by occlusion, but was markedly reduced or eliminated with griseofulvin. Healing of the lesions occurred more rapidly in the griseofulvin-continuous-occlusion group than in any other group. This study suggests that either occlusion of the inoculated site or oral griseofulvin markedly reduces the expected area of the fungal lesion, and occlusion together with griseofulvin shortens the duration of the lesion.

Animals↗
PubMed1977

Serodiagnosis of hepatitis B virus infection by antibody to core antigen.

In a military population antibody to hepatitis B core antigen (anti-HBc) was found in 39% of acute hepatitis cases negative for hepatitis B surface antigen (HBS Ag) and in 96% of HBs Ag-positive cases. Persistence of antibody to HBs Ag (anti-HBs) in convalescent-phase sera was significantly greater (P less than 0.001) in individuals with acute HBs Ag-positive hepatitis B than in patients with clinical HBs Ag-negative hepatitis B. The prevalence of anti-HBc in the absence of HBs Ag, anti-HBs, and clinical disease was 3.2% in this military population. In longitudinal studies of hepatitis B infection, the presence of anti-HBc preceded anti-HBs and improved the ability to determine the onset of sublicnical infection. Anti-HBc is a useful serologic marker for the study of the epidemiology of hepatitis B and improves the efficiency of detection of hepatitis B virus infection.

Animals↗
PubMed1977

Effects of prolonged continuous exposure of human skin to water: a reassessment.

Continuous exposure of human skin to water in small plastic cups for periods of 72 and 144 hr produced a mild, transient dermatitis in half the sites tested. The degree of dermatitis was only slightly greater at 144 than at 72 hr, and was unrelated to the pH of the water samples. Comparison of soap-pretreated to non-pretreated skin areas showed a significant tendency for the more severe dermatitis to be present on the non-pretreated skin areas at higher pH's. There was virtually no coating of hairs with waxy yellowish material (clumps of bacteria), and no lesion was produced that resembled warm-water-immersion injuries.

Adult↗
PubMed1976

Persistence of antibody to hepatitis B surface antigen.

Sera from military personnel found to have antibodies to hepatitis B surface antigen (anti-HBS) in an epidemiological study of a hepatitis B outbreak were tested for persistence of that antibody 1 year later. Initially, 64% of the anti-HBS-positive sera reacted in passive hemagglutination tests with erythrocytes coated with hepatitis B surface antigen of both ayw and adw subtypes; the remaining sera reacted only with adw-coated erythrocytes (19%) or ayw-coated erythrocytes (17%). After 1 year, anti-HBS was detectable by passive hemagglutination tests in 87% of individuals with initial antibody to both subtypes but in only 41% and 16% (P less than 0.001) of those initially reacting only to adw- or ayw-coated erythrocytes, respectively. Seropositivity for anti-HBS correlated best with history of contact with jaundiced people (20.3%) and duty in Asia.

Adult↗