Complement Fixation Reaction for the Diagnosis of Type II Avian (Marek''s) Leukosis

The present study was designed to find a complement fixation (CF) reaction for the diagnosis of type II lymphoid leukosis, to learn some of the characteristics of the CF antigen, and to investigate the development of CF antibody response to this infection. JM virus-specific antigen was demonstrated in tumorous chicken tissue, in JM virus-infected chick embryo material, in JM virus-infected chicken kidney, and in duck embryo fibroblast tissue culture by using JM virus-immune rabbit serum. This CF antigen did not show cross-reactivity with Rous sarcoma virus or with RIF-type viruses. It was partially heat-labile. The CF activity was restored at -70 C for 10 months and was resistant to intermittent freeze-thaw treatment. The CF antigen may be denatured by ethyl alcohol, but no significant deleterious effects were noted after ether or chloroform treatment. JM virus-specific CF antibody could not be demonstrated by the direct complement dilution method or by the indirect or inhibition form of the CF test in infected or immunized chicken sera.     

Physicochemical factors affecting ethanol adsorption by activated carbon

Powder and granular activated charcoal were evaluated for ethanol adsorptivity from aqueous mixtures using an adsorption isotherm. Ethanol adsorption capacity was more pronounced at 25 degrees C as compared to 5, 15, and 40 degrees C. When pH of the ethanol-buffer mixture (0.09 ionic strength) was changed from acidic (2.3) to neutral and then to alkaline (11.2), ethanol adsorption was decreased. Increasing ionic strength of the ethanol-buffer mixtures from 0.05 to 0.09 enhanced ethanol adsorption but a further increase to 0.14 showed no significant effect. Ethanol adsorption was more efficient from an aqueous ethanol mixture as compared to semidefined and nondefined fermentation worts, respectively. Heating granular charcoal to 400 degrees C for 1 h and 600 degrees C for 3 h in N(2) increased ethanol adsorptivity and heating to 1000 degrees C (1 h) in CO(2) decreased it when ethanol was removed from dilute solutions by simple pass adsorption in a carbon packed column. Granular charcoal was superior to powdered charcoal and an inverse relationship was noted between the weight of the granular carbon bed in the column and ethanol adsorbed/g carbon. Decreasing the column feed flow rate from 7.5 to 2.0 L aqueous ethanol/min increased the adsorption rate.     

Immunodiffusion method for detection of type A Clostridium botulinum.

A simple gel immunodiffusion agar procedure was developed for detecting toxigenic strains of Clostridium botulinum type A. The method consisted of overlaying colonies grown on thin-layer tryptone-peptone-glucose-yeast extract agar with gel diffusion agar containing desired levels of C. botulinum type A antitoxin. Concentric precipitin zones formed around colonies of C. botulinum type A. Strains of C. botulinum type A were detected by this procedure. However, C. botulinum type B reacted to a lesser degree with this system. No reaction was noted with types E, F, Langeland, F8G, Clostridium perfringens, or with strains of nontoxigenic Clostridium sporogenes. Thickness of the plating medium, incubation time and temperature, environmental growth conditions, and levels of both agar an antitoxin were important factors affecting the efficiency of the procedure, whereas the age of the culture (used as inoculum) was not critical. Thin agar medium (5 ml per plate [15 by 100 mm]) containing 1.5% agar gave consistent results, but more agar limited diffusion, and lower levels encouraged spreaders. The optimal concentration of antitoxin incorporated in to the gel diffusion agar overlay was 1.2 IU/ml gel diffusion agar. Rabbit type A antitoxin prepared with purer immunizing agent gave similar reactions. The addition of type A antitoxin in tryptone-peptone-glucose-yeast extract agar medium before inoculation with type A C. botulinum showed promising results.     

Fate of Staphylococcus aureus in Bruised Tissue

This investigation was initiated to determine the fate and behavior of a virulent marker strain of Staphylococcus aureus (MS) injected intramuscularly into both control and traumatized tissues. Control tissues appeared to possess a clearing mechanism highly active against this organism, whereas bruised tissues stimulated and supported its growth. This stimulation may be due to the presence of extrastromal hemoglobin in the bruised areas. By use of the disc-sensitivity procedure, extrastromal hemoglobin was found to enhance the growth of S. aureus (MS) and this stimulation was linearly dependent on concentration in the range of 0.002 to 0.008 μmole per disc. Physical and physiological factors affecting the fate of staphylococci in poultry tissues were studied. The results showed that the number of viable cells of S. aureus (MS) in the initial inoculum exerted little effect on the survival activity patterns of this organism in the traumatized tissues. Control tissues, however, only became infected when a suspension containing 1.34 × 10⁹ cells of the marker strain was injected. Regardless of the concentration of cells of this test culture inoculated into bruised areas, the staphylococci did not increase in number above a log of 8.5 organisms per gram of tissue. The extent of both tissue damage and accumulation of blood and fluid seemed to play an important role in the fate of staphylococci in experimentally induced infection. A correlation was noted between the severity of the bruise and the rate of growth and multiplication of virulent staphylococci in the tissue. The rate of growth showed a 100-fold increase in 1 day in the severe bruise, in 2 days in the medium bruise, and in 3 days in the superficial bruise. Time-course studies revealed that virulent S. aureus (MS) was able to persist in bruised tissue for long periods of time (18 days) even in the absence of noticeable infection. Therefore, it is believed that bruised tissue is a source of contamination to other birds and a health hazard to man.     

Effect of alfacalcidol on natural course of renal bone disease in mild to moderate renal failure.

OBJECTIVE--To determine whether alfacalcidol--used in management of overt renal bone disease--may safely prevent renal bone disease when used earlier in course of renal failure. DESIGN--Double blind, prospective, randomised, placebo controlled study. SETTING--17 nephrology centres from Belgium, France, the Netherlands, and the United Kingdom. SUBJECTS--176 patients aged 18-81 with mild to moderate chronic renal failure (creatinine clearance 15-50 ml/min) and with no clinical, biochemical, or radiographic evidence of bone disease. INTERVENTIONS--Alfacalcidol 0.25 micrograms (titrated according to serum calcium concentration) or placebo given for two years. MAIN OUTCOME MEASURES--Quantitative histology of bone to assess efficacy of treatment and renal function to assess safety. RESULTS--132 patients had histological evidence of bone disease at start of study. Biochemical, radiographic, and histological indices of bone metabolism were similar for the 89 patients given alfacalcidol and the 87 controls given placebo. After treatment, mean serum alkaline phosphatase activity and intact parathyroid hormone concentration had increased by 13% and 126% respectively in controls but had not changed in patients given alfacalcidol (P < 0.001). Hypercalcaemic episodes occurred in 10 patients given alfacalcidol (but responded to decreases in drug dose) and in three controls. Histological indices of bone turnover significantly improved in patients given alfacalcidol and significantly deteriorated in controls: among patients with abnormal bone histology before treatment, bone disease resolved in 23 (42%) of those given alfacalcidol compared with two (4%) of the controls (P < 0.001). There was no difference in rate of progression of renal failure between the two groups. CONCLUSION--Early administration of alfacalcidol can safely and beneficially alter the natural course of renal bone disease in patients with mild to moderate renal failure.