Simazine: Degradation by Soil Microorganisms

A soil fungus, Aspergillus fumigatus Fres., is effective in the degradation of the herbicide 2-chloro-4,6-bis(ethylamino)-s-triazine (simazine). The degradation of both ring-and chain-labeled (C(14)) simazine was observed in an unamended and an amended (sucrose) basal medium. A loss of C(14) occurred in all culture solutions containing either ring-or chain-labeled simazine, but the decrease in activity observed was greater with chain-labeled than with ring-labeled simazine. Chromatographic evidence indicates that A. fumigatus may possess a degradation mechanism unlike that which occurs in corn plants.     

Diseases of the adrenal cortex of dogs and cats

Of cases of hyperadrenocorticism in small animals 80-85% are the result of adrenocortical hyperplasia. Middle-aged or older Poodles, Dachshunds, Boston Terriers and Boxers are most commonly affected, and cats rarely. Clinical signs include polydipsia, polyuria, alopecia, abdominal distension, lethargy, weakness, hepatomegaly, calcinosis cutis, testicular atrophy and anestrus. Hematologic and biochemical changes may include neutrophilia, lymphopenia, monocytosis, eosinopenia, increased blood levels of alkaline phosphatase, SGPT, cholesterol, Na and glucose, and decreased K and T4 levels. The high-dosage dexamethasone suppression test helps differentiate pituitary-dependent hyperadrenocorticism from that caused by adrenal tumors. The low-dosage dexamethasone suppression test, determination of plasma ACTH levels, and ACTH response test are additional diagnostic aids in the diagnosis of Cushing's disease. Medical treatment involves oral use of mitotane (o,p'-DDD) at 50 mg/kg/day for 7 days and prednisone or prednisolone at 0.05 mg/kg/day. Hypophysectomy has been used with only 5% mortality in cases of pituitary-dependent hyperadrenocorticism. Adrenalectomy is indicated in cases of adrenal neoplasia.     

IgG subclasses and IgM in rats: immunoregulatory effects of cimetidine on serum levels

Previous studies have demonstrated an immunomodulatory role for cimetidine on antibody production. In these experiments we measured IgG subclasses and IgM in rats and also examined the effects of cimetidine on serum levels. Four week-old Sprague-Dawley rats were given cimetidine in three different treatment regimens. IgG subclasses and IgM determinations were carried out by radial immunodiffusion method on sera when animals were 6 and 8 weeks old. IgG1 levels in 6 week-old animals who received intraperitoneal cimetidine on days 1, 2, 3, 4, 5, 6, 8, 9, 15 and 16 were significantly higher (305 +/- 12 mg/l vs 236 +/- 53 in control animals). By 8 weeks of age in control animals, IgG1 levels had fallen to 78 mg/l and were statistically lower than the levels in all cimetidine treatment groups. Eight week-old control animals also demonstrated a four-fold fall in IgG2b levels (613 +/- 310 mg/l) when compared to in 6 week-old control (2295 +/- 1057 mg/l) animals, or 8 week-old animals who had received cimetidine. Animals receiving intravenous cimetidine on days 4, 11 and 18 had significantly lower (133 +/- 3 mg/l) serum levels of IgG2c, at 6 weeks of age, as compared to control animals (177 +/- 16); however, no statistically significant differences in IgG2c levels were observed in 8 week-old animals. No statistically significant differences in the levels of IgG2a or IgM were observed in either 6 or 8 week-old control and experimental animals. It appears that cimetidine does influence certain IgG subclasses, however, route and timing of cimetidine administration are critical in modulating these effects.     

Efficacy of chlorfenapyr (AC 303630) experimental pour-on and CyLence formulations against naturally acquired louse infestations on cattle in New York

The four chlorfenapyr formulations examined provided 100% control of both the nymphal and adult stages of naturally acquired Bovicola bovis (L.) on cattle up to 35 days after application. Treatment with 6mg chlorfenapyr per kg BW in a 0.12ml per kg BW formulation was as effective as treatment with CyLence (cyfluthrin) in controlling naturally acquired Solenopotes capillatus (Enderlein) on cattle for 35 days. Percent reduction was never greater than 90% with any chlorfenapyr application against Linognathus vituli (L.). However, percent reduction was greater than 90% with CyLence from day 21 through 35. No adverse effects were noted on cattle from any of the chlorfenapyr dosages used.     

Human CSF-1: molecular cloning and expression of 4-kb cDNA encoding the human urinary protein

A 4-kilobase complementary DNA (cDNA) encoding human macrophage-specific colony-stimulating factor (CSF-1) was isolated. When introduced into mammalian cells, this cDNA directs the expression of CSF-1 that is structurally and functionally indistinguishable from the natural human urinary CSF-1. Direct structural analysis of both the recombinant CSF-1 and the purified human urinary protein revealed that these species contain a sequence of at least 40 amino acids at their carboxyl termini which are not found in the coding region of a 1.6-kilobase CSF-1 cDNA that was previously described. These results demonstrate that the human CSF-1 gene can be expressed to yield at least two different messenger RNA species that encode distinct but related forms of CSF-1.     

A whiff of oxygen before the great oxidation event?

High-resolution chemostratigraphy reveals an episode of enrichment of the redox-sensitive transition metals molybdenum and rhenium in the late Archean Mount McRae Shale in Western Australia. Correlations with organic carbon indicate that these metals were derived from contemporaneous seawater. Rhenium/osmium geochronology demonstrates that the enrichment is a primary sedimentary feature dating to 2501 +/- 8 million years ago (Ma). Molybdenum and rhenium were probably supplied to Archean oceans by oxidative weathering of crustal sulfide minerals. These findings point to the presence of small amounts of O2 in the environment more than 50 million years before the start of the Great Oxidation Event.     

Hurricane Allen's Impact on Jamaican Coral Reefs

Coral reefs of north Jamaica, normally sheltered, were severely damaged by Hurricane Allen, the strongest Caribbean hurricane of this century. Immediate studies were made at Discovery Bay, where reef populations were already known in some detail. Data are presented to show how damage varied with the position and orientation of the substraturn and with the shape, size, and mechanical properties of exposed organisms. Data collected over succeeding weeks showed striking differences in the ability of organisms to heal and survive.     

Measurement of the effect of Amazon smoke on inhibition of cloud formation

Urban air pollution and smoke from fires have been modeled to reduce cloud formation by absorbing sunlight, thereby cooling the surface and heating the atmosphere. Satellite data over the Amazon region during the biomass burning season showed that scattered cumulus cloud cover was reduced from 38%in clean conditions to 0%for heavy smoke (optical depth of 1.3). This response to the smoke radiative effect reverses the regional smoke instantaneous forcing of climate from -28 watts per square meter in cloud-free conditions to +8 watts per square meter once the reduction of cloud cover is accounted for.