Decreased activity of the sodium-calcium exchanger in tail artery of stroke-prone spontaneously hypertensive rats.

The ability of the Na-Ca exchanger to modify vascular relaxation was studied in rings isolated from tail arteries of stroke-prone spontaneously hypertensive rats (SHRSP) and normotensive Wistar-Kyoto rats (WKY). The arteries were contracted with norepinephrine (NE) 1 microM and after stabilization they were transferred to a Ca-free physiological salt solution still in presence of NE. The time to 50% relaxation (T-50) in these conditions was significantly greater in SHRSP (78 +/- 7 s) than in WKY (50 +/- 7 s). When the calcium pump was stopped with vanadate (VAN), the Ca uptake by the sarcoplasmic reticulum with ryanodine (RY) and the Na-Ca exchanger with a Na-free PSS, the relaxation was slowed (T-50 increased to 198 +/- 16 s in SHRSP and to 162 +/- 14 s in WKY). Releasing the Na-Ca exchanger only (i.e. still with VAN and RY but with normal Na in the bath) the T-50 for relaxation in Ca-free PSS was, in WKY, nearly as fast as in control conditions (54 +/- 8 s). However, the Na-Ca exchanger in SHRSP was not so effective, and the T-50 for relaxation was slower than in control conditions (122 +/- 10 s). We conclude that the activity of the Na-Ca exchanger is depressed in tail arteries of SHRSP. This abnormality in resistance vessels, would contribute to the enhanced vascular tone present in hypertension.

Sodium-calcium exchange in vascular smooth muscle of Wistar-Kyoto and stroke-prone spontaneously hypertensive rats.

The role of the sodium-calcium (Na-Ca) exchange in vascular smooth muscle contraction was examined in tail artery rings isolated from stroke-prone spontaneously hypertensive rats (SHRSP) and in normotensive Wistar-Kyoto rats (WKY). The rings were repeatedly stimulated with noradrenaline (1 microM) in physiological salt solution (Na = 130 mM), until two successive contractions were of the same magnitude. The rings were then placed in physiological salt solution with reduced sodium concentrations (65 mM or 0 mM, replaced isosmotically with sucrose), and the noradrenaline stimulations continued. In WKY rings, the reduction of sodium concentration produced an increase in the response to noradrenaline, which was significant in sodium-free physiological salt solution. In SHRSP rings, however, the same reductions in sodium concentration produced significantly less potentiation of the noradrenaline contraction, even in sodium-free physiological salt solution. We conclude that (1) in WKY, the reduced and reversed activity of the Na-Ca exchange produced by the reductions in sodium concentration makes more calcium available for contraction when the smooth muscle is stimulated with noradrenaline; and (2) the failure of sodium reductions to produce a normal potentiation of the response to noradrenaline in SHRSP indicates a depressed activity of the Na-Ca exchange in this tissue.

Sexual problems and their management: a survey of general practice in Northern Ireland.

This survey suggests a similar prevalence of sexual problems in general practice in Northern Ireland compared with England and Wales. Of the respondents, 9.6% reported a much higher prevalence which may indicate a greater ability in detecting sexual problems and therefore implies that many cases are being missed. The majority of problems appear to be dealt with in general practice, although referral is often considered, with the Psychosexual Clinic being the preferred option. Difficulties encountered with referral are highlighted by the survey. It is suggested that provision of more information about the clinic, visits by therapists to practices and further training opportunities would help general practitioners in managing sexual problems.

Purification and comparative studies of alcohol dehydrogenases.

Alcohol dehydrogenases from various animal and plant sources were purified by a common procedure which employed DEAE, Sephadex-G100 and affinity chromatographies. The procedure achieves an 80-130 fold purification for animal enzymes. However, only a 5-15 fold purification for plant enzymes was attained because of the instability of these enzymes. Purified alcohol dehydrogenases from animal and plant sources differ in coenzyme and substrate specificities. The enzymes from mammalian, avian and fish livers display aldehyde oxidizing and esterolytic activities in addition to alcohol oxidizing activity. However, the enzymes from plants and yeast show only the oxidative activity toward alcohols. Chemical modifications have been performed to identify amino acid residues which are essential to the oxidative and esterolytic activities of alcohol dehydrogenases.

A review of referrals to the psychosexual clinic at the Belfast City Hospital.

The number of patients seen at the psychosexual clinic has more than doubled in eight years. The diagnostic categories of the patients referred have also changed, especially in the area of homosexuality, and now show greater similarity to figures obtained in two reports from Great Britain, apart from a lower referral rate for orgasmic dysfunction. There is also an overall lower rate of referral in Northern Ireland. This raises the question as to whether or not there is a real difference in the prevalence of these disorders in the Province, compared with Great Britain.

Nonpersimmon gastric phytobezoar. A benign recurrent condition.

Phytobezoars are intragastric concretions composed of food or persimmon fruit. Previous studies of patients with phytobezoars have had a preponderance of patients with persimmon phytobezoars; little clinical information is available regarding nonpersimmon phytobezoars. We report the cases of 52 patients with nonpersimmon phytobezoars and contrast our experience with that previously reported for patients with persimmon phytobezoars. Our patients experienced pain (67%), nausea and vomiting (50%), diarrhea (13%), and gastric ulcers (14%). No patient with a phytobezoar died. Two thirds of our patients had conditions that could alter gastric motility. Medical therapy successfully dissolved 91% of the phytobezoars. One fifth of our patients had a phytobezoar redevelop. Compared with patients with persimmon phytobezoars, we conclude that patients with nonpersimmon phytobezoars have (1) different symptoms, (2) a low risk of complications or death, (3) effective medical therapeutic options, and (4) a 19% risk of phytobezoar recurrence.

A comparison of the anti-anaphylactic activities of salbutamol and disodium cromoglycate in the rat, the rat mast cell and in human lung tissue.

1 Salbutamol and disodium cromoglycate were compared for anti-anaphylactic activity against passive anaphylaxis in rat skin and peritoneum in vivo and in rat mast cells and human lung fragments in vitro.2 Salbutamol administered intravenously to rats inhibited cutaneous anaphylaxis, but also inhibited cutaneous responses to histamine and 5-hydroxytryptamine. Salbutamol administered intraperitoneally inhibited the release of slow reacting substance of anaphylaxis (SRS-A) but not the release of histamine in the peritoneum. It was a very weak inhibitor of histamine release from rat mast cells in vitro.3 Disodium cromoglycate administered intravenously to rats inhibited cutaneous anaphylaxis. Disodium cromoglycate administered intraperitoneally to rats inhibited the release of histamine and, to a lesser extent, SRS-A in the peritoneum. It was an effective but short-acting inhibitor of histamine release from rat mast cells in vitro.4 Salbutamol was a potent inhibitor of the anaphylactic release of histamine and SRS-A from fragments of human lung.5 Disodium cromoglycate was a weak inhibitor of the anaphylactic release of histamine and SRS-A from fragments of human lung. The inhibition was variable and not dose-related.6 The concentration of salbutamol required to inhibit anaphylaxis in human lung is of the same order as that required to relax human bronchial muscle. It is suggested that salbutamol may be more effective in allergic asthma if given in a prophylactic regimen.

Bioenergetics in clinical medicine. IX. Gingival and leucocytic deficiencies of coenzyme Q10 in patients with periodontal disease.

The specific activities of the succinate dehydrogenase-coenzyme Q10 reductase in mitochondria were determined for patients from a normal periodontal practice. The criteria for selection were patients having a bone score of 1.0-4.0 and a pocket depth of 2.5-5.2 mm. All 29 patients showed a deficiency of 20-63% of CoQ10-enzyme activity in gingival biopsies. The mean value was elevated (P less than 0.001) over that of controls. For corresponding blood samples, 24/28 (86%) showed deficiencies of 20-66% and a higher (P less than 0.001) mean value than that of controls. Periodontal patients frequently have significant gingival and leucocytic deficiencies of CoQ10. The leucocytic deficiency indicates a systemic nutritional imbalance and is not likely caused by neglected oral hygiene. A gingival deficiency could predispose this tissue to periodontitis and this disease could even augment the deficiency. These results support previously suggested adjunctive use of CoQ10 with oral hygiene for improved treatment presumably through bioenergetics.

Feedback in behavior modification: an experimental analysis in two phobic cases.

Two illustrations of single-case research are described in which an isolated therapeutic variable was sequentially introduced, withdrawn, and reintroduced while changes in a clinically relevant behavior were measured. A claustrophobic patient and a knife-phobic patient received graduated practice in facing their phobic stimuli; length of time the claustrophobic patient stayed in a small dark room per trial, and length of time the knife-phobic patient kept knife exposed per trial were measured. In both experiments, when feedback of these time scores was withdrawn, ongoing progress was retarded. Reinstatement of feedback led to renewed improvement. In Experiment 2, adding and removing contingent verbal praise against a constant background of precise feedback did not significantly alter rate of progress.