Hepatogenous photosensitisation in fallow deer (Dama dama) in New Zealand.

An outbreak of hepatogenous photosensitisation occurred in fallow deer and was diagnosed as facial eczema on the basis of liver lesions and plasma enzyme changes over 56 weeks. Clinical signs of photosensitisation were not as obvious as they are in sheep and cattle. The condition occurred over autumn and in the following spring. Six of 23 deer died or were destroyed. Concentrations of plasma total bilirubin, total bile acids and cholesterol increased, as well as the activities of aspartate transaminase, glutamic dehydrogenase, lactic dehydrogenase, alkaline phosphatase and gamma glutamyltransferase. Albumin:globulin ratios declined due to moderate increases in globulin and minor reductions in albumin. Many of the plasma enzyme activities did not return to normal after autumn and increased to even higher values during the spring outbreak of photosensitisation. Minor plasma biochemical changes were also detected in non-photosensitive deer in the same herd.

Seed characteristics and nutrient composition of selected beans (Phaseolus vulgaris L.) with different ozone tolerance.

Ozone sensitivity, nutritional quality, seed characteristics, and growth habit of beans (Phaseolus vulgaris L.) were evaluated in two separate experiments. In the first experiment the data showed a significant variation among 34 bean accessions for ozone sensitivity following acute exposure of 18-day-old plants to 0.6 microliters/l O3 for 2 hours under environmentally controlled greenhouse conditions. PI-163579, PI-169735, PI-171790, PI-176684, PI-201374, PI-310711, PI-345576, PI-370569, PI-379435, and PI-414831 were identified as tolerant to acute ozone exposures. Protein, oil, starch, sugar, and ash contents in the seed of selected germplasm were determined and no correlation was found between these components and ozone sensitivity. Seed size and growth habit varied considerably among the 34 accessions but were not correlated to ozone sensitivity. In a second experiment, ten accessions, selected from the tolerant ones identified in the first experiment, were subjected to chronic ozone exposure in open-top chambers at 0.04 and 0.08 microliters/l concentrations for 7 hours/day 44 days after transplanting. Based on foliar injury and yield reductions, only PI-370569 and PI-414831 were tolerant to prolonged ozone exposure (0.08 microliters/l). A significant positive correlation (r = 0.83) existed between foliar injury rating from chronic treatments involving 0.04 and 0.08 microliters O3/l and acute exposure (0.6 microliter O3/l/2 hours). The data indicated that acute ozone exposure can be used to initially screen a large number of bean accessions, however, this is an imperfect indicator of ozone sensitivity with chronic exposure.

Structure-activity relationships in the myotoxicity of ring-methylated p-phenylenediamines in rats and correlation with autoxidation rates in vitro.

A number of N-methylated p-phenylenediamines are known to cause necrosis of skeletal and cardiac muscle in rats. The severity of the muscle damage induced by these compounds in vivo was found to be directly proportional to their autoxidation rates in vitro, suggesting that reactive species formed during oxidation may be involved in the initiation of this toxic effect. In the present study, the in vitro oxidation rates and in vivo toxicities of a number of ring-methylated p-phenylenediamines have been evaluated. 2,3,5,6-Tetramethyl p-phenylenediamine readily autoxidized at neutral pH. Hydrogen peroxide was formed in this reaction, while oxidation in the presence of glutathione or reduced pyridine nucleotides led to the production of both hydrogen peroxide and superoxide radical. Less highly methylated derivatives oxidized more slowly, with rates decreasing in the order 2,3,5,6-tetramethyl greater than 2,5-dimethyl greater than 2,6-dimethyl greater than 2-methyl. All these compounds were myotoxic in rats, with damage being largely confined to skeletal muscle. Toxicity was again proportional to oxidation rate. Myotoxicity appears to be a general property of certain substituted p-phenylenediamines and the structure-activity relationships identified may permit an estimate to be made of the potential toxicity of other compounds of this type.

Muscle necrosis by N-methylated p-phenylenediamines in rats: structure-activity relationships and correlation with free-radical production in vitro.

Certain derivatives of p-phenylenediamine have been shown to cause necrosis of cardiac and skeletal muscle in rats; in vitro, such compounds are known to autoxidize to the corresponding radical cations, with concomitant formation of oxygen free-radicals. In the present study, the autoxidation rates of p-phenylenediamine and its N-methyl, dimethyl, trimethyl and tetramethyl derivatives have been determined and compared with the severity of the muscle necrosis induced by each of these compounds in rats. A close correlation was observed between autoxidation rate in vitro and toxicity in vivo, suggesting that free-radical species may be involved in the initiation of the muscle damage caused by these substances.

The ability of biochemical and haematological tests to predict recovery in periparturient recumbent cows.

Blood samples from 433 periparturient recumbent cows submitted by veterinary practitioners to Ruakura Animal Health Laboratory during 1983 and 1984 were analysed and results related to whether cows recovered, died or were euthanased. Generally cows were sampled only once and the time varied from 15 minutes to 20 days after becoming recumbent. During 1983 serum calcium, magnesium, phosphorus, creatine phosphokinase (CK), aspartate amino transferase (AST), glutamate dehydrogenase (GDH), gamma glutamyl transferase (GGT) were analysed. In 1984 serum urea, creatinine, fibrinogen and haematological examination (haemoglobin, haematocrit, total and differential white cell counts) were added to the panel. Overall 39% of cows recovered, 30% died and 32% were destroyed. Precalving cows had 111% more deaths and 7% less survivors than postcalving recumbent cows (P<0.1). There was little difference (3%) in euthanasia prevalence. Tests that were most useful in predicting a lack of recovery were serum urea and muscle enzymes. Using these tests and duration of recumbency when sampled a model was produced to predict the probability of recovery from 254 cases.

A comparison of perceived and actual dental needs of a select group of children in Texas.

Dental caries (DMFS) evaluations were made for 150 children in Grades 2 to 7. Three months later, a trained interviewer questioned 120 children from 100 families to determine atitudes toward oral hygiene and dental health on the part of (a) the child, (b) the parent, along with (c) the child's perception of the parent's attitude, and (d) the parent's perception of the child's attitude. Evaluation of the perceived attitudes toward oral hygiene revealed a statistically significant correlation between the child's attitude and the degree of dental health as well as between the attitudes of child and parent. Conclusions were: (1) parents were not accurate in their perception of the dental health habits of their children, (2) children were not performing acceptable routine oral hygiene procedures, (3) children accurately perceived the attitudes of their parents toward dental health, and (4) children's actual dental health behavior as manifested by dental health status was related to the attitudes of their parents.