The importance of calcium ions forin vitro malignant hyperthermia testing

Intracellular Ca++ levels in skeletal muscle are elevated during the in vitro contracture response of muscle from subjects with malignant hyperthermia. The role of Ca++ in the bathing medium and the consequences of substitution of Sr++ for Ca++ in the response to agents associated with malignant hyperthermia were examined. When Ca++ was omitted from the bathing medium the contractures induced in human vastus lateralis by halothane (three per cent) or succinylcholine (50 mM) were reduced by 80 and 100 per cent, respectively, while contractures induced by caffeine (8 mM) were only reduced by 50 per cent. Substitution of Ca++ by another divalent cation, Sr++, completely restored contractures induced by caffeine, but only partially restored contractures induced by halothane or succinylcholine (to 50 and 30 per cent of Ca(++)-containing medium, respectively). Mepacrine (10 microM) was effective in antagonizing contractures by caffeine, whereas verapamil and nifedipine (10 microM) were not. These results support an essential role for extracellular Ca++ not fulfilled by Sr++ in contracture induction by halothane and succinylcholine, but not by caffeine.     

Gemfibrozil reduces plasma prothrombin fragment F1 + 2 concentration, a marker of coagulability, in patients with coronary heart disease.

The effects of gemfibrozil on several indices of haemostatic activity were explored in male patients with coronary heart disease (CHD). Sixty-three of 71 patients completed a crossover study in which gemfibrozil 1,200 mg/day and matching placebo were each taken in randomised order for 2 months in a double-blind manner, separated by a 2-month washout period. Serum cholesterol decreased by an average (95% confidence interval) of 12 (9 to 15)% and non-fasting triglyceride concentration by 43 (34 to 51)% during active treatment. Plasma prothrombin fragment F1 + 2 concentration, a marker of the in vivo rate of generation of thrombin, was 25 (12 to 37)% lower on average while on gemfibrozil than during the placebo phase. Factor VII coagulant activity (VIIc) and antigen concentration, and fibrinopeptide A concentration were not influenced by gemfibrozil in the group overall. However, the VIIc response appeared to be dependent upon the untreated cholesterol level. Hypercholesterolaemic men (cholesterol greater than 6.5 mmol/l) experienced a significant reduction in VIIc averaging 6% of standard during active therapy. Other effects of gemfibrozil were a 5 (2 to 9)% increase in plasma fibrinogen by a gravimetric method, an 11 (8 to 13)% increase in platelet count, and a 6 (2 to 10)% reduction in white cell count. The reduced incidence of CHD following gemfibrozil therapy in hyperlipidaemic patients may arise in part through a reduction in procoagulant activity and thus the risk of an occlusive coronary thrombosis.     

Patient well-being: a responsibility for hospital managers

Managers can and should affirm their role in helping patients reach their potential for wellness. They are in a position to influence the therapeutic process and increase patient satisfaction     

A population survey of retinitis pigmentosa and allied disorders in Denmark. Completeness of registration and quality of data.

The aim of this study was a complete survey of all patients in Denmark with a diagnosis of retinitis pigmentosa. The study was performed during the period 1986-1989 and included all persons living in Denmark from 1850 to 1989. We describe the methods of registration from medical and non-medical sources, based on defined criteria. The inclusion criteria were fulfilled by 1890 persons, 1056 males and 834 females. Evaluation of this 'Danish Retinitis Pigmentosa Register' demonstrates an overall completeness of about 80%, increasing from 40% for birth cohorts before 1911 to 90% for patients born since 1981. Concerning diagnostic confidence, 73% of the probands were characterized as certain, 16% as probable, and 11% as possible. Non-systemic cases comprised 61% of all probands and 31% had systemic disease, the rest being unclassified with respect to systemic involvement. The material is considered very suitable for epidemiological treatment and continuous clinical and genetic investigations.     

Weapon involvement and injury outcomes in family and intimate assaults.

OBJECTIVE--To compare the risk of death and the risk of nonfatal injury during firearm-associated family and intimate assaults (FIAs) with the risks during non-firearm-associated FIAs. DESIGN--Records review of police incident reports of FIAs that occurred in 1984. Victim outcomes (death, nonfatal injury, no injury) and weapon involvement were examined for incidents involving only one perpetrator. SETTING--City of Atlanta, Ga, within Fulton County. PARTICIPANTS--Stratified sample (n = 142) of victims of nonfatal FIAs, drawn from seven nonfatal crime categories, plus all fatal victims (n = 23) of FIAs. MAIN OUTCOME MEASURES--Risk of death (vs nonfatal injury or no injury) during FIAs involving firearms, relative to other types of weapons; risk of nonfatal injury (vs all other outcomes, including death) during FIAs involving firearms, relative to other types of weapons. RESULTS--Firearm-associated FIAs were 3.0 times (95% confidence interval, 0.9 to 10.0) more likely to result in death than FIAs involving knives or other cutting instruments and 23.4 times (95% confidence interval, 7.0 to 78.6) more likely to result in death than FIAs involving other weapons or bodily force. Overall, firearm-associated FIAs were 12.0 times (95% confidence interval, 4.6 to 31.5) more likely to result in death than non-firearm-associated FIAs. CONCLUSIONS--Strategies for limiting the number of deaths and injuries resulting from FIAs include reducing the access of potential FIA assailants to firearms, modifying firearm lethality through redesign, and establishing programs for primary prevention of violence among intimates.     

Commentary: methods women can use that may prevent sexually transmitted disease, including HIV.

Although sexually transmitted diseases, including human immunodeficiency virus (HIV), are a major concern for women, few prevention messages are targeted specifically to women. Those that are generally stress abstaining, altering the number or selection of partners, and urging partners to use condoms. But these behaviors may be unrealistic for many women, particularly women who are at highest risk for sexually transmitted diseases, because they require significant changes in life-style or depend on male-controlled condom use. Recommendation of contraceptives for prevention of sexually transmitted diseases depends largely on how well specific methods perform under controlled conditions, either in the laboratory or in clinical trials. Observational studies, which better reflect day-to-day use, indicate that condoms, barriers, and spermicides, used properly and consistently, can provide substantial protection against various sexually transmitted diseases. Condoms can similarly help protect against HIV, but studies of barriers and spermicides are scant and currently inconclusive. Finally, those methods that are controlled by women are consistently more effective in preventing sexually transmitted diseases. Thus, although condoms used well are still the best choice, the imperative for female-controlled methods indicates that diaphragms and spermicides should receive greater emphasis in prevention messages.     

Differential analgesic effects of low-dose epidural morphine and morphine-bupivacaine at rest and during mobilization after major abdominal surgery.

In a double-blind, randomized study, epidural infusions of low-dose morphine (0.2 mg/h) combined with low-dose bupivacaine (10 mg/h) were compared with epidural infusions of low-dose morphine (0.2 mg/h) alone for postoperative analgesia at rest and during mobilization and cough in 24 patients after elective major abdominal surgery. All patients in addition received systemic piroxicam (20 mg daily). No significant differences were observed between the groups at any assessment of pain at rest (P greater than 0.05), whereas pain in the morphine/bupivacaine group was significantly reduced during mobilization from the supine into the sitting position 12 and 30 h after surgical incision and during cough 8, 12, and 30 h after surgical incision (P less than 0.05). We conclude, that low-dose epidural bupivacaine potentiates postoperative low-dose epidural morphine analgesia during mobilization and cough. Evaluation of postoperative analgesic regimens should include assessment of pain during various activities as different analgesics may have differential effects on pain at rest and during mobilization.