Linoleic acid hydroperoxide: impaired bacterial uptake by alveolar macrophages, a mechanism of oxidant lung injury

Exogenous linoleic acid hydroperoxide causes in vitro impairment of both bacterial uptake and the phagocytic stimulation of (14)CO(2) production from [1-(14)C]glucose in rabbit alveolar macrophages by an undefined effect on the cell membrane. This effect may be one mechanism for the defective pulmonary bacterial clearance characteristic of oxidant lung injury.     

Development of an enzyme-linked immunosorbent assay for the detection of the organophosphorus insecticide acephate

A competitive indirect enzyme-linked immunosorbent assay (ciELISA) for the organophosphorus insecticide acephate, O,S-dimethyl acetylphosphoramidothioate, was developed using a polyclonal antibody. Five different haptens mimicking the analyte were synthesized and conjugated with the carrier proteins bovine serum albumin (BSA) and keyhole limpet hemocyanin (KLH) by the N-hydroxysuccinimide active ester and diazotization methods. Polyclonal antibodies raised against hapten-KLH conjugates in rabbits and hapten-BSA conjugates as coating antigens were screened and selected for the assay in the homologous and heterologous ELISA systems. The effects of various assay conditions such as detergent, organic solvents, pH, and preincubation of the mixture of the polyclonal antibody and the analyte on the sensitivity were evaluated. The IC(50) value for acephate was 25 ng/mL in an optimized heterologous system using hapten-4-BSA as a coating antigen and a polyclonal antibody no. 8377 against hapten-1-KLH, showing the detection range of 5-140 ng/mL and the lowest detection limit of 2 ng/mL. The cross-reactivities of the structurally related organophosphorus insecticides, including the major metabolite of the analyte, methamidophos, were less than 1%. Recoveries from the analyte-fortified tap water, mulberry leaves, and lettuce samples in the assay were in the range of 72-121% by simple extraction, concentration, and dilution. These results indicate that the ELISA could be a convenient and supplemental analytical tool for monitoring acephate residues in environmental and agricultural samples.     

Morphometric and steroid hormone changes associated with experimental anovulatory follicles in the sow.

Steroid levels and ovarian follicular morphology were examined in sows on days 19 and 26 (day 5 of next cycle) after injection of adrenocorticotropic hormone (ACTH) or dexamethasone (DXM). Five sows received DXM (30 micrograms/kg bodyweight, intramuscularly) at 12 h intervals from days 9 to 14. Another five sows were given ACTH (2 IU/kg bodyweight, intramuscularly) from day 17 to day 19 or the end of estrus. Five control sows received no treatment. Ovulation occurred only in control sows and progesterone was significantly elevated at day 26. Estradiol values in ovarian vein blood were low but variable on day 19 in DXM- and ACTH-treated animals. Androstenedione values were lower (p less than 0.05) on both days in sows receiving DXM but not in those given ACTH compared to control values on day 19. Morphometric analysis, based on six follicles in each of three sows from each treatment group, indicated that follicular and antral diameters and granulosa cell numbers did not differ for either hormone treatment group on either day compared to those of control sows on day 19. The mitotic index suggested that cell replication continued. However, pyknotic and karyorrhectic nuclei were also seen in the hormone treatment groups. Follicles and oocytes from both DXM- and ACTH-treated sows showed signs of early degenerative changes including disorganization of cumulus cells and large lipid droplets in the cytoplasm of oocytes. Significant differences from control follicles in granulosa cell density and theca interna cell density suggested an association with the altered steroid hormone secretion.     

BLUETONGUE CERTIFICATION—AUSTRALIAN POLICY

Australian quarantine policies with respect to BT are based on regarding this disease as one of high risk and major potential economic importance to our ruminant population. There are deficiencies in our knowledge of world distribution, epidemiology and pathogenesis. There may be unknown vectors and unsuspected animal reservoir hosts. The international distribution of BT could be extending through the movements of insects or cattle. If introduced into Australia, the cattle and sheep populations would probably be at continuous risk as eradication would be difficult or impossible. Costs to the sheep industry at least could be high and productivity gravely affected. To reduce the probability of introduction, imports of ruminants and semen have, for the last 16 years, been restricted to a very small number of countries presumed free from BT. Future policies will almost certainly be based on these same considerations taking into account scientific advances in diagnosis and virus detection. The establishment of an off-shore high security quarantine station will facilitate imports of ruminants even from known BT-infected countries.     

A STORAGE-LIKE DISEASE WITH SKELETAL INVOLVEMENT IN A DOG

A storage-like disease in a 14-month-old Rhodesian Ridgeback dog is described. Clinically the dog was lame on all legs, and appendicular joint capsules were distended. Radiographically and at necropsy, there was evidence of osteoarthritis, increased volume of synovial fluid, and marked hypertrophy of the synovial membranes. Large mononclear cells with vacuolated cytoplasm were evident in synovial membranes. Large mononuclear cells with vacuolated cytoplasm were evident in synovial membranes. Large mononuclear cells with vacuolated cytoplasm were evident in synovial membranes, bone marrow, liver, lymph nodes, and endocrine glands. Vacuolated cells in lymph nodes stained positively for fat. Transmission electron microscopy revealed empty membrane-bound cytoplasmic vacuoles. The similarity of this disease to storage diseases in man where arthropathy is a feature is discussed.