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Biomedical subjects

J D Davis

Publications and source records attributed to J D Davis.

At least 91 records · Page 5Linked to original sources
PubMed1979

Pirprofen and aspirin in the treatment of rheumatoid arthritis.

Pirprofen (800 mg/day) or aspirin (3,600 mg/day) was administered in double-blind fashion for up to one year to 40 adult outpatients with rheumatoid arthritis, after a short, single-blind placebo period. There were no statistically significant differences in efficacy between pirprofen and aspirin, as evidenced by patient opinion, observer opinion, grip strength, walking time, number of tender joints, number of swollen joints, or erythrocyte sedimentation rate. Clinically significant pain of gastrointestinal origin occurred in an equal number of patients from each group. Audiologic evaluation revealed 3 pirprofen-treated patients and 5 aspirin-treated patients in whom sensorineural hearing loss progressed during therapy and required either discontinuation or reduction of drug dosage. Ophthalmologic evaluation disclosed a high prevalence of lesions, the most common being decreased visual acuity and cataracts not explained by previous antiarthritic therapy. The high prevalence of audiologic and ophthalmologic pathology reported in the literature in patients with rheumatoid arthritis makes it difficult to establish in our study whether pirprofen or aspirin affected these organ systems.

Adult↗
PubMed1979

Ultrasonic absorption in liver tissue.

Ultrasonic attenuation coefficients were measured in mammalian liver for frequencies ranging from 0.5 to 10 MHz and for a range of sample preparations. Certain preparative procedures were found to greatly increase the low-frequency attenuation coefficient due to the introduction of bubbles into the sample. The low-frequency attenuation was reduced by storage at low temperatures or by pressurization, each caused the bubbles to go into solution, resulting in an attenuation coefficient that was a simple power function of frequency. Absorption coefficients of in vitro and in vivo samples were found to be similar and to show much less dependence on sample preparation than the attenuation measurements. These studies suggest that properties of carefully prepared in vitro samples are indicative of the in vivo properties.

Animals↗
PubMed1978

Distention of the small intestine, satiety, and the control of food intake.

The studies reported here investigated the role that filling of the small intestine plays in the control of ingestion. Adding mannitol, a nonabsorbable carbohydrate, to a palatable solution reduced meal size in rats in proportion to its concentration. Intake is suppressed for the duration of time that the small intestine remains full. If dietary fiber, which sequesters water and swells, fills the small intestine sufficiently, it may act to suppress meal size and prolong the length of intermeal intervals.

Animals↗
PubMed1978

Exacerbation of mixed connective tissue disease during Salmonella gastroenteritis--serial immunological findings.

A patient with mixed connective tissue disease is described who developed fever and polyserositis after the onset of Salmonella gastroenteritis. Antiribonucleoprotein antibodies, serum complement, and circulating immune complexes were studied quantitatively throughout the course of her illness. If the Salmonella infection were responsible for the exacerbation of mixed connective tissue disease, as the sequence of events suggests, the mechanism appeared to involve deposition of previously circulating immune complexes in affected tissues.

Adult↗
PubMed1977

Body weight: reduction by long-term glycerol treatment.

Elevation of body glycerol concentration by multiple daily injections of glycerol was shown to lead to hypophagia and body weight loss followed by normal food intake and normal rate of body weight increase in rats. Termination of injections was followed by hyperphagia and an accelerated rate of growth. These findings suggest that the blood glycerol concentration plays an important role in the control of body weight and may be one signal by which the central nervous system monitors body lipid content.

Animals↗
PubMed1977

Fenoprofen, aspirin, and gold induction in rheumatoid arthritis.

Fenoprofen calcium (2,400 mg/day) or aspirin (3,900 mg/day) was administered in double-blind fashion to 20 rheumatoid patients during 6 months of gold induction therapy, and to 20 rheumatoid patients not receiving gold. Among both the gold-treated and nongold-treated patients, the fenoprofen and aspirin groups improved equally in all but one parameter of disease activity. Fenoprofen and aspirin did not differ significantly in the observed prevalences of abdominal discomfort, guaiac-positive stools, or peptic ulcers. Aspirin was associated with significantly higher mean serum glutamic oxaloacetic transaminase (SGOT) levels than fenoprofen, but only among patients undergoing gold induction. Comparison of efficacy parameters between patients treated with gold and patients treated with oral drugs alone revealed significant differences favoring gold.

Adult↗
PubMed1977

Set points, settling points, and the control of body weight.

Recently a number of investigators have suggested that body weight may be controlled by a neural system which contains a reference or set point. The finding that the body weight level which animals will defend can be altered by lesions of the lateral and ventromedial hypothalamus has been taken to provide support for this claim. In this paper we describe a simple feedback control model which contains no set point, and yet is able to account in full for these and other data which have been cited in support of the existence of a body weight set point. Since such a model exists it appears to be unnecessary and unparsimonious to introduce the concept of a neural set point to explain the fact that body weight maintains a relatively constant value which is defended against certain types of challenges. Constancy and defense of body weight are at best only prima facie evidence for the existence of a neural set point controlling body weight.

Animals↗
PubMed1977

Effects of communication about interpersonal process on the evolution of self-disclosure in dyads.

In an earlier investigation, like-sex partners in an acquaintance exercise were found to match their mean levels of intimacy. This "consensus" was achieved through the adoption of asymmetric roles, whereby one partner would consistently set the pace with respect to intimacy, and the other would reciprocate. It was proposed that such unilateral control of the dyad's evolution would be replaced by shared control if partners were encouraged to discuss the problem of how intimate to be with one another. As predicted, role asymmetry gave way to role symmetry when such communication took place. In addition, partners were able to match their mean levels of intimacy during the exercise without recourse to matching on a moment-to-moment basis. In place of a monotonic increase in intimacy, dyads followed a curvilinear course marked by an accelerated increase and a subsequent tapering off or decrease in intimacy level. The findings are discussed in relation to the more general question of how consensus is achieved in the social construction of an encounter or relationship.

Communication↗
PubMed1975

Peripheral control of drinking: gastrointestinal filling as a negative feedback signal, a theoretical and experimental analysis.

The studies described here investigated the hypothesis that the osmotic postingestional satiety signal proposed by McCleary operates through a mechanism related to gut filling rather than by osmotically induced shifts of fluid from osmoreceptors in the brain. A control theory model is presented, which was designed to make quantitatively explicit the hypothesis under question. The results showed that when mannitol, which is not absorbed from the intestine, is added to a highly palatable saccharin-glucose mixture, the amount of fluid consumed decreased in inverse proportion to the mannitol concentration. Mannitol was also shown to block fluid absorption from the intestine at a low concentration (approximately .070 M) and at higher concentrations to lead to a net flux of fluid into the intestinal lumen. It was also shown that mannitol in concentrations that reduced the intake of the palatable solution did not induce thirst when the animals were in water balance. It did induce thirst, however, when the animals were tested in a state of negative water balance. The results of these studies, considered as a whole, support the view that McCleary's osmotic postingestional satiety signal acts as an intestinal distention signal rather than by inducing thirst. The model is found to be reasonably accurate as a first approximation, and suggestions are made for improvements.

Animals↗