Human intravenous immunoglobulin preparation and virus inactivation by pasteurization and solvent detergent treatment

Human intravenous immunoglobulin (IVIG) solutions were prepared by two different methods and compared to each other. The crude immunoglobulin fraction obtained from Cohn-Oncley fractionation of plasma was further purified and subjected to virus inactivation, either by polyethylene glycol precipitation and pasteurization at 60 degrees C for 10 hours, or by ion exchange chromatography and solvent/detergent treatment. The final preparations, formulated in 5% immunoglobulin solutions were characterized by in vitro analyses of biochemical and biological properties and compared with the samples of other manufacturer's IVIG solution products. The critical properties evaluated in this study were purity, molecular intactness, and the biological functions such as Fc function and anticomplementary activity. Virus inactivation and removal by processing steps and by deliberate virucidal steps, as described above, were tested on various human pathogenic viruses, such as human immunodeficiency and experimental model viruses. The tested viruses were successfully inactivated and removed. We conclude that the intravenous immunoglobulins prepared by two different methods, as described above, provide an equivalent viral safety and quality.

Autoantibodies and related immunity of leprosy patients from leprosarium in Taiwan

Autoantibodies and related immunological examinations were measured in 60 leprosy patients from a leprosarium in Taiwan. Thirty-one lepromatous type, 24 tuberculoid type and 5 borderline type patients were identified. The measured autoantibodies included antinuclear antibodies, anti-nDNA, anti-cardiolipin and rheumatoid factor. Serum protein electrophoresis and immunofixation were also performed to detect the monoclonal and polyclonal status of immunoglobulins. Circulating immune complex and complements were also quantitated. Delayed type skin tests were performed during patients' visits. A higher frequency of autoantibodies, especially the antinuclear antibodies and anticardiolipin antibodies, were detected in lepromatous type patients. Higher levels of circulating immune complex and frequency of polyclonal and monoclonal gammopathy were also noted in lepromatous type patients. Anergy skin tests were only noted in lepromatous type patients. It was concluded that the more impared cell-mediated immunity in leprosy patients, with lepromatous type in particular, the greater the production of autoantibodies.

Color pattern-reversal visual evoked potential in eyes with ocular hypertension and primary open-angle glaucoma

Color pattern-reversal visual evoked potential testing was performed in 99 normal eyes, 27 eyes with ocular hypertension and 30 eyes with primary open-angle glaucoma with the use of black-white, black-red and black-blue color checkerboard stimuli. The P1 wave peak time and amplitude of the eyes with ocular hypertension and glaucoma were significantly different from those of age-similar normal eyes, especially on the black-red and black-blue checkerboards (p less than 0.001). The differences between the ocular hypertensive and glaucomatous eyes were of less significance. The P1 peak time difference between black-white and black-red checkerboards may serve as an important parameter in the early diagnosis of glaucoma.

Minimal inhibitory concentrations of isoniazid, rifampin, ethambutol, and streptomycin against Mycobacterium tuberculosis strains isolated before treatment of patients in Taiwan

Minimal inhibitory concentrations (MICs) of isoniazid (INH), rifampin (RMP), ethambutol (EMB), and streptomycin (SM) for susceptible "wild" M. tuberculosis strains isolated from Taiwanese patients were within the limits previously reported for strains isolated in the United States. The highest agar-determined MICs (in 7H10 and 7H11 agar) corresponded well with the critical concentrations established for these media. The highest MICs found radiometrically in 7H12 broth were significantly lower than the critical concentrations proposed for this medium. On the basis of an evaluation of the highest broth-determined MICs found in this and in the previous study (1), we suggest that the following MICs, when determined radiometrically, should be used as breakpoints to classify the strain as "susceptible": for INH, 0.1 microgram/ml or less; for RMP, 0.5 microgram/ml or less; for EMB, 4.0 micrograms/ml or less; for SM, 2.0 micrograms/ml or less.

Segregation of proteins and sodium in human plasma upon freezing

The proteins and sodium in human source blood plasma are segregated and concentrated on freezing, particularly in plasma that is frozen slowly in a large container. The temperature and the concentration gradients at the freezing front induce a convection in the liquid phase and thus play the primary role in the segregation of proteins and sodium in the frozen mass. Unidirectional freezing, where the freezing front moves against gravity, minimizes segregation because the density gradient-induced convection is minimized at the solid-liquid interface. Microscopic observation of the freezing front of the plasma indicates that ice crystals are the primary solid formed. Their shape is generally irregular, and they become highly dendritic as the freezing rate increases. Apparently, the liquid phase at the freezing front is trapped between the ice crystals; it then undergoes a complex secondary freezing process at a lower temperature behind the primary freezing front of the ice crystals.