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J M Barbaree

Publications and source records attributed to J M Barbaree.

28 records · Page 2Linked to original sources
PubMed1981

Studies on the thermal degradation of the H and M antigens of lyophilized histoplasmin.

Lyophilized histoplasmin for the agar gel microimmunodiffusion test has been prepared as a candidate World Health Organization Biological Reference Reagent. It was subjected to elevated temperature for given periods of time and analyzed by the capillary precipitin test and the single radial immunodiffusion test to determine the stability of the H and M antigens. H antigen showed no fall in relative potency when incubated at 48 degrees C for 20 days. M antigen showed a fall in relative potency after storage at 37 degrees C and 48 degrees C, but the extent of the fall was greater in the radial immunodiffusion test than in the capillary precipitin test. Half-lives of the antigens could not be calculated from the Arrhenius equation because the response curves at each temperature followed different kinetics. However, as based on zero time data, M antigen of the lyophilized histoplasma showed a 20% drop in relative potency when stored at -20 degrees C for 2 years. Other analyses suggested that M antigen of liquid histoplasmin stored at 5 degrees C and of lyophilized histoplasma stored at -20 degrees C was degraded at equal rates.

Animals↗
PubMed1979

Stability of a reference panel of lyophilized hepatitis B antigens and antibodies.

A lyophilized hepatitis B working/reference panel has been prepared for use in standardization tests. This panel includes HBsAg, anti-HBs, HBeAg/anti-HBe and subtype reagents. Quantitative analysis of the HBsAg reagents indicates that at a storage temperature of -20 degrees C, only 1 log at maximum of RIA counts per minute would be lost in 95 years. After storage at -20 degrees C for 1 year, there has been no loss of reactivity in any of the tests used to detect HBsAg, anti-HBs, HBeAg/anti-HBe or subtypes.

Antibodies, Viral↗
PubMed1977

Comparative Statistical Study of the Cornwall, LKB, and Micromedic Dispensers.

The working precisions of the 5.0-ml-capacity Cornwall, the LKB 2075, and the Micromedic model 25000 dispensers were compared, and the bias of the LKB dispenser was contrasted with that of the Micromedic dispenser. Three technologists used six Cornwall dispensers, three LKB units with four different pumps, and three Micromedic units with six different pumps to dispense (in 1.0-ml amounts) sucrose solution adjusted to match the normal viscosity of serum. Under these conditions, the LKB dispenser was approximately 30% more precise than the Micromedic dispenser, which was approximately four times as precise as the Cornwall dispenser. Although the left pump site of the Micromedic was slightly more precise than the LKB, overall the Micromedic was less precise than the LKB. Moreover, the LKB was easier to use than the Micromedic.

Journal Article↗
PubMed1976

Methods for determining favorable conditions for freeze-drying biological reference materials.

By predetermining favorable conditions for freeze-drying samples through pilot runs, one can gain more assurance that relatively large batches of lyophilized biological reference materials produced have the desired characteristics. Included in the pilot studies are the determination of the characteristics of the lyophilizer with a specific freeze-drying cycle, simulation of the water load expected for the production run, residual moisture analyses of the lyophilized samples, and biological activity of the samples before lyophilization and after exposure to elevated temperatures. Various reference materials have been lyophilized by these procedures. Among them are clinical chemistry reference samples, bacterial suspensions, and candidate serum-protein reference immunological standards. A batch of 6,300 vials of the latter was successfully freeze-dried and showed less than 0.1% residual moisture; different proteins (including complement) were both functionally (enzymatically) and antigenically active.

Bacteria↗
PubMedDate not supplied

Tick-borne tularemia. An outbreak of lymphadenopathy in children.

Between June 1 and July 15, 1984, twenty persons with glandular tularemia were identified on the Lower Brule and Crow Creek Indian reservations in South Dakota. The median age of the patients was 6 years (range, 2 to 20 years). The clinical illness was mild, consisting of fever, headache, and lymphadenopathy. All lymphadenopathy was in the head and neck area. Dermacentor variabilis ticks were identified as the vector. Although the mild clinical illness suggested Francisella tularensis, type B, was the agent, both type A and type B strains of F tularensis were isolated from ticks collected from dogs in the area. Tularemia is generally thought to be a severe systemic illness in North America. This outbreak illustrates that it can be a mild disease and that both type A and type B strains can be tick-borne and coexist in the same ecosystem.

Adolescent↗
PubMedDate not supplied

Characterization of an axenic strain of Hartmannella vermiformis obtained from an investigation of nosocomial legionellosis.

A free-living amoeba identified as Hartmannella vermiformis was isolated from a water sample obtained during an investigation of nosocomial legionellosis. Hartmannella vermiformis is known to support the intracellular multiplication of Legionella pneumophila. This strain of H. vermiformis, designated CDC-19, was cloned and established in axenic culture to develop a model for the study of the pathogenicity of legionellae. Isoenzyme patterns of axenically-cultivated strain CDC-19 were compared with two strains of H. vermiformis derived from the type strain, one axenic (ATCC 50236) and the other grown in the presence of bacteria (ATCC 30966). Enzyme patterns suggested that all three strains are assignable to the species H. vermiformis. Axenic H. vermiformis strain CDC-19 has been deposited with the American Type Culture Collection (ATCC 50237) and should prove useful in the study of protozoan-bacterial interaction.

Animals↗
PubMedDate not supplied

Differences in the pathogenicity of various bacterial isolates used in an induction model for gangrenous dermatitis in broiler chickens.

A gangrenous dermatitis model was developed in broiler chickens, in which birds previously vaccinated at 14 days of age with a bursal disease virus vaccine were challenged at 4 wk of age with various bacterial combinations with the combination of subcutaneous and intramuscular injection. Gangrenous dermatitis lesions were not produced in birds injected with one of the Staphylococcus aureus isolates, either alone or in combination with various Clostridium septicum isolates. Other S. aureus isolates produced significant levels of gangrenous dermatitis either alone or in combination with the same C. septicum isolates. These same C. septicum isolates when given alone did not produce gangrenous lesions. Data from this experiment show the highest level of mortality occurred in birds challenged with a mixture of C. septicum and S. aureus isolates, whereas lower or no mortality was associated with the same isolates given separately. The data clearly demonstrate that the pathogenicity of isolates responsible for gangrenous dermatitis varies widely, indicating that the frequency and severity of lesion production, as well as the occurrence of mortality, are largely dependent upon the specific isolate or isolates with which the birds are challenged.

Administration, Cutaneous↗