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Biomedical subjects

A Watson

Publications and source records attributed to A Watson.

At least 253 records · Page 14Linked to original sources
PubMed1986

Environmentally-induced analgesia: age-related differences in a hormonally-mediated, nonopioid system.

In order to study the age-related differences in analgesia produced by environmental stimuli, 3-month-old, 11-month-old, and 23-month-old rats were immersed in 6 degrees C water for 5 min. Prior to cold-water exposure, different groups of rats were injected (i.p.) with 7 mg/kg of naltrexone or saline or had adrenalectomies performed. Following cold-water immersion, pain sensitivity was measured for 2 hr. In the saline-treated groups, there was a progressive increase in the analgesia displayed after cold-water exposure as the age of the group increased. For each age group, naltrexone did not attenuate the analgesia produced by cold water whereas adrenalectomy potentiated the analgesia. The effects of naltrexone and adrenalectomy confirm that cold-water exposure produces a hormonally-mediated, nonopioid analgesic response. Thus, these results demonstrate that aged animals display an enhanced analgesic response to cold-water stress that is similar to other neuroendocrine indexes of increased hormonal response to stress in aged organisms.

Adrenal Glands↗
PubMed1985

Hormonal mediation of the analgesia produced by food deprivation.

Research has demonstrated that a wide variety of environmental conditions are capable of producing analgesia. In the present experiment, the analgesia produced by 24 hr of food deprivation was examined following adrenalectomy, hypophysectomy, naltrexone (7 mg/kg), dexamethasone (0.4 mg/kg), or saline treatment. Results revealed that 24 hr of starvation elicited an analgesic response in the saline-treated and sham-operated groups. Naltrexone, dexamethasone, adrenalectomy, and hypophysectomy blocked the analgesia produced by food deprivation. The results demonstrate that 24 hr of food deprivation induced an opiate-mediated analgesic system that involves hormonal factors.

Adrenal Cortex Hormones↗
PubMed1985

Increase in tracheal size with age. Implications for maximal expiratory flow.

Because mechanical properties of central airways play an important role in determining maximal expiratory flow, we examined how tracheal size and maximal expiratory flow changed with age in 50 asymptomatic men, 19 to 61 yr of age, who were lifelong nonsmokers. Cross-sectional area (X-SA) of the intrathoracic trachea was estimated from posteroanterior and lateral chest radiographs taken at full inflation. Maximal expiratory flow-volume curves and spirometry were measured by standard techniques. Tracheal X-SA averaged 2.81 cm2 (SD, 0.38) at mean age 21.1 yr and 3.22 cm2 (SD,0.41) at mean age 52.5 yr, and correlated with peak expiratory flow (PEF) (r = 0.522, p less than 0.001) and FEV1 (r = 0.437, p = less than 0.01) (both expressed as percent predicted values based on age and height). These relationships were weaker than previously described in young men. The results suggest that with increasing age, large airways lose elastic recoil, as previously described for the air spaces. Aging changes in the airways may offset the unfavorable effects of loss of lung recoil and account for the relatively good preservation of PEF and the lack of rise in airways resistance with increasing age.

Adult↗
PubMed1984

The role of antireflux surgery combined with fiberoptic endoscopic dilatation in peptic esophageal stricture.

A clinical study of a personal series of 120 patients with peptic esophageal stricture has been conducted. All of the patients were managed by intermittent fiberoptic dilatation performed with diazepam sedation and antireflux measures. Reflux control was attempted pharmacologically early in the study in all patients and subsequently by antireflux surgery in younger patients. Dilatation was performed in all patients as frequently as necessary to maintain satisfactory swallowing. In the 42 surgically treated patients, an effective antireflux operation was achieved, principally by an abdominal approach, without mortality. A single dilatation was sufficient in 71 percent of these patients, the mean number of dilatations required to maintain adequate swallowing being 1.6 during a mean follow-up period of 3.3 years. In the medically treated group, a single dilatation sufficed in 41 percent of the patients, the mean number of dilatations required being 3.1 in a similar follow-up period. In three patients in the latter group esophageal carcinoma superimposed on their peptic stricture while they were under surveillance. Although not randomized, this study suggests that antireflux surgery is beneficial in younger patients for reducing the need for subsequent dilatations and prolonged medication, which may be relevant in the context of the incidence of carcinoma in preexisting peptic strictures in this series and in series reported by others. The conclusions that thought to justify the controlled clinical trial currently in progress to further elevate this impression.

Adult↗
PubMed1984

Respiratory morbidity in wollastonite workers.

Medical and environmental surveys were conducted at a wollastonite mine and mill in 1976 and in 1982. Health testing included chest radiography, spirometry, and a questionnaire. Workers at a nearby electronics plant were also examined in 1982 for a comparison of lung function and respiratory symptoms. Both wollastonite and control workers showed significant smoking effects for chronic respiratory symptoms, but differences between the groups were not detected. Pneumoconiosis was found in 3% (3/108) of the wollastonite workers in 1982, but none showed a significant progression from their 1976 radiographs. The lung function tests of the 108 wollastonite workers examined in 1982 showed dust related changes in FEV1, FEV1/FVC ratio, and peak flow rate which were independent of age, height, and smoking habit (p less than 0.01). For non-smokers alone, only the FEV1/FVC ratio declined significantly with dust-years of exposure (p less than 0.01). The comparison of lung function in 1982 between a high dust exposed subgroup of wollastonite workers and the control population showed a significantly lower FEV1/FVC ratio and peak flow rate in the study group (p less than 0.05). Analysis of 1976-82 changes in pulmonary function showed that wollastonite workers with higher dust exposure had a significantly greater decline in peak flow over the period than workers with lower exposures (p less than 0.01). These data suggest that long term cumulative exposure to wollastonite may impair ventilatory capacity as reflected by changes in the FEV1/FVC ratio and peak flow rate.

Adult↗