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Biomedical subjects

B J Hawkins

Publications and source records attributed to B J Hawkins.

8 recordsLinked to original sources
PubMed1988

The effects of carbon monoxide on persistent changes in young rat heart: cardiomegaly, tachycardia and altered DNA content.

Newborn rat pups that inhale 500 ppm carbon monoxide (CO) for 32 days and develop increased heart mass (i.e. cardiomegaly) show persistent cardiomegaly and elevated resting heart rate as adults. Studies were carried out to explore the relationship of these phenomena to CO concentration and initial cardiomegaly using exposures of 350, 500 and 700 ppm CO. Initial cardiomegaly was greater in the right ventricle free wall (RV) than in the left ventricle plus interventricular septum (LV + S) at all three CO concentrations, and RV mass excess increased with CO concentration. Initial RV cardiomegaly was greater at 350 and 700 ppm CO in females than in males. Persistent cardiomegaly in the RV also increased with CO concentration, and was significantly greater in the females. Persistent cardiomegaly in the RV increased with initial cardiomegaly but at a decreasing rate at the higher CO concentrations, and when expressed as a percentage of initial cardiomegaly (i.e. 'efficiency'), the relative response was greatest at 500 ppm CO. For LV + S, efficiency of development of persistent cardiomegaly was greatest at 350 ppm CO. Persistent tachycardia increased with CO concentration in males but failed to do so in females, and was only weakly correlated with degree of persistent cardiomegaly. Thus, persistent cardiomegaly and persistent tachycardia (in males) are related to CO concentration. Myocardial DNA content of 32-day-old juveniles was significantly increased at 350 and 700 ppm CO. Adult DNA content of the RV was significantly elevated at 350 ppm CO (females) and continued to rise with CO concentration. DNA concentrations of the RV and LV were increased at 700 ppm CO.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1988

Hallux rigidus.

This article discusses the pathophysiology in the development of the hallux rigidus deformity. The clinical and radiographic findings are discussed and identified. Various modalities of conservative and surgical care are discussed.

Arthrodesis↗
PubMed1987

Effect of litter size (i.e. nutrition) on carbon monoxide-induced persistent heart changes.

It was hypothesized that manipulation of litter size, thus nutrition, which has been shown to alter the neonatal response to cardiovascular stress (i.e. carbon monoxide) might also alter persistent post-stress changes. Rat pups reared in litters of 4 and 16 inhaled 500 ppm CO for 32 days ("CO"), or served as controls ("AIR"). Some pups were killed at 14-15 days of age to assess initial cardiomegaly. As adults, right ventricle (RV) mass was greater in CO/4 males (123 days of age) and females (113 days of age) than in same sex CO/16 rats. Persistent RV cardiomegaly was present in CO/4 males and females compared to AIR's of the same litter size and sex, whereas this was the case only in females comparing CO/16 and AIR/16 rats. RV mass was significantly larger in AIR/4 males than in AIR/16 males. Plots of initial cardiomegaly (both ventricles) versus persistent cardiomegaly (RV) for large and small litters produced similar slopes for the two sexes, with females lying above males. Resting heart rate, monitored in males (66-121 days of age) and females (81-109 days of age), was increased by small litter size, and also by CO, particularly in the males. Resting heart rate was significantly correlated with RV weight. RV DNA content and concentration were increased by small litter size in the males, and concentration also by CO. The male CO/4 rats had the highest DNA content and concentration. In the females, DNA content was increased by small litter size and was greatest in the CO/4 group. Thus, the effects of small litter size have lasting effects: i.e. augmented persistent cardiomegaly, persistent tachycardia, and myocardial DNA content and concentration.

Aging↗
PubMed1986

Periodontal disease. Therapy and prevention.

Success in veterinary dentistry lies in good home care and regular, thorough dental prophylaxis. The removal of supragingival and subgingival calculus must be accomplished before periodontal disease can be controlled. When gingival sulcus depths exceed 4 or 5 mm, the gingivae must be excised or reflected to allow proper treatment of the pocket area. Antibiotic therapy should be instituted in the extensively involved veterinary dental patient.

Animals↗
PubMed1979

Acute oral marijuana poisoning in the dog.

Ingestion of marijuana by three dogs in unrelated incidents resulted in depression-type toxicosis in each case. The most evident clinical signs were central nervous system depression and ataxia. Emesis and hypothermia were noted in two of the cases. Symptomatic and supportive treatment was accompanied by clinical improvement. In two cases, recovery was slow, with clinical signs apparent for 36 to 48 hours after onset. In the third case, clinical signs were apparent for only 3 hours.

Animals↗