Psychologic evaluation in the management of chronic pain and disability

This article attempts to provide a practical template for the psychologic assessment of chronic pain and disability. Topics discussed include differential diagnosis, goals of psychosocial assessment, psychologic constructs, personality issues, pain-drawing ratings, and multidimensional assessment instruments. Other factors affecting psychologic assessment, such as litigation, perception of disability, pain behavior, and cultural factors are also discussed.     

Effects of prostaglandins and the autonomic nervous system on the vasodilatory properties of nitroglycerin in conscious dogs.

This study was designed to assess the respective roles of prostaglandins and the autonomic nervous system in the responses to nitroglycerin (NTG) in conscious dogs. In vivo, NTG (1, 10, and 100 micrograms/kg i.v.) induced dose-dependent decreases in blood pressure and increases in heart rate and cardiac output. Coronary and carotid blood flows increased simultaneously, whereas responses in renal blood flow were biphasic, i.e., an initial decrease was followed by an increase above control at 10 and 100 micrograms/kg. NTG responses were not changed by indomethacin but were affected by chlorisondamine alone or in combination with indomethacin; tachycardia was abolished, and increases in cardiac output after 10 and 100 micrograms/kg were reduced by 26 and 32%, respectively, after ganglionic blockade and by 19 and 32%, respectively, after chlorisondamine plus indomethacin. In addition, increases in carotid blood flow in doses of 100 micrograms/kg were reduced by 88% after chlorisondamine and 83% after chlorisondamine plus indomethacin. Finally, in the presence of chlorisondamine plus indomethacin, NTG induced a more pronounced hypotension associated with a more pronounced renal vasodilation at the highest dose. Independent of indomethacin pretreatment, NTG in vitro induced a dose-dependent relaxation of the carotid, coronary, and renal arteries. Depending on the vascular bed, the reflex and local controls of circulation are affected differently by NTG.     

Prevalence of Legionella in pharyngeal secretions of patients with pharyngitis

A serological investigation has suggested that Legionella pneumophila may be associated with sore throat in adults. In a study of 177 adults and children with acute pharyngitis, Legionella species were not isolated from pharyngeal cultures, which utilized selective and nonselective buffered charcoal-yeast extract media. Group A beta-hemolytic streptococci were isolated from 14 percent of the 177 symptomatic patients. Throat cultures from 88 asymptomatic control subjects were negative for Legionella and beta-hemolytic streptococci. Further studies are needed to determine if Legionella species are associated with acute pharyngitis.     

Do viscous polysaccharides slow absorption by inhibiting diffusion or convection?

Viscous polysaccharides such as guar gum delay absorption probably by impairing the access of luminal contents to the absorptive epithelium. Measurements of the electrical resistivity of saline solutions were carried out to determine if guar gum (0.5, 0.75 and 1 per cent w/v), in concentrations which impaired absorption in vitro, delayed diffusion of solutes or inhibited convection of luminal contents. Our results indicated that guar had no effect on the mobility of ions in a completely unstirred solution but delayed the time taken for saline solutions of different resistivity to achieve complete mixing, when they were brought into contact inside a vessel, which was rotated at a constant speed. The time taken to achieve complete mixing was directly related to the viscosity of the guar solutions. The effect of intestinal contraction on the absorption of glucose was simulated in an in vitro model, consisting of a length of dialysis tubing, alternately contracted at each end. Movement of glucose out of the dialysis tubing was increased by increasing the rate of contraction. The incorporation of guar gum into the solution prevented the rise in glucose uptake produced by increasing the rate of contraction. These effects suggest that guar probably reduces absorption by resisting the convective effects of intestinal contractions.     

Scotopic stimulus/response relations of the B-wave of the electroretinogram

Scotopic b-wave stimulus/response (S/R) functions are abnormal in several human retinal degenerative disorders. However, the mechanisms by which diseases affect the S/R parameters are not yet fully known. Three experiments were done to simulate functional pathologies known to occur in retinal degenerations: 1) attenuated sensitivity of retinal units, 2) loss of rhodopsin, 3) loss of sensitivity with little or no loss of rhodopsin. None of the experimental perturbations of normal function replicated the pattern of S/R abnormalities caused by retinal degenerations. Thus, in the retinal degenerative disorders intrinsic abnormalities of cellular processing must affect the organization of distal retinal function indexed by the b-wave.     

A case of Datisca glomerata poisoning in beef cattle

Six of 175 Angus heifers died after ingesting excessive amounts of Durango root (Datisca glomerata). Animals had rumens full of Durango root, were extremely lethargic, and had diarrhea prior to death. The animals had nonspecific postmortem lesions. This case is discussed in light of previous findings from trials in which Durango root was experimentally fed to cattle.     

Withdrawal of bromocriptine after long-term therapy for macroprolactinomas; effect on plasma prolactin and tumour size

The present study describes the effect on plasma prolactin values and tumour size of bromocriptine withdrawal in 12 patients who had been treated for macroprolactinomas for a period of 3.5-7 (mean 4.9) years. Pretreatment plasma prolactin values ranged from 12,000 to 210,000 (mean: 66,000) mU/l. Immediately before bromocriptine withdrawal plasma prolactin values were in the normal range (less than 350 mU/l for men; less than 450 mU/l for women). Bromocriptine treatment was associated with tumour reduction in all cases. The following observations were made upon withdrawal of bromocriptine: (1) In 11 patients hyperprolactinaemia redeveloped although plasma prolactin levels remained below 600 mU/l in two of these patients during a follow-up period of 1 year. In the other nine patients bromocriptine treatment was reinstituted after 4-12 weeks. (2) Hyperprolactinaemia was associated with tumour reexpansion in one case and increased density of the tumour in two cases. (3) In one patient plasma prolactin remained undetectable during a follow-up period of 1 year and no tumour re-expansion was found. It is concluded that tumour regrowth is uncommon and of small extent after cessation of long-term bromocriptine treatment for macroprolactinomas.