Serum magnesium and ischaemic heart disease: findings from a national sample of US adults.

BACKGROUND: Animal and human data suggest that magnesium may play an important role in ischaemic heart disease. Few prospective epidemiological studies have related serum magnesium concentrations to mortality from ischaemic heart disease (IHD) or all-causes. METHODS: Data from the National Health and Nutrition Examination Survey Epidemiologic Followup Study were used to examine the association between serum magnesium concentration, measured between 1971-1975, and mortality from IHD or all-causes in a national sample of 25-74-year-old participants followed for about 19 years. RESULTS: The analytical samples for IHD and all-cause-mortality included 12 340 and 12 952 participants, respectively (1005 IHD deaths, 2637 IHD deaths or hospitalizations, 4282 total deaths). Hazard ratios for IHD mortality from proportional hazards analysis comparing the second (1.59-<1.68 mEq/l), third (1.68-<1.77 mEq/l), and fourth (> or =1.77 mEq/1) quartiles of serum magnesium concentration with the lowest quartile were 0.79 (95% CI: 0.58-1.08), 0.66 (95% CI: 0.47-0.93), 0.69 (95% CI: 0.52-0.90), respectively. For all-cause mortality, hazards ratios were 0.82 (95% CI: 0.72-0.93), 0.84 (95% CI: 0.73-0.96), 0.85 (95% CI: 0.75-0.95). No significant interactions between serum magnesium concentration and age, sex, race, and education were observed. CONCLUSION: Serum magnesium concentrations were inversely associated with mortality from IHD and all-cause mortality.     

Mental health. As you don't like it

The publication of the national service framework for mental health provides a good opportunity to review acute psychiatric services, which are unpopular with patients and understaffed. The framework recommends a balance of hospital beds, community provision and home care. Planning should usually cover one or more primary care groups.     

Differences between the vasorelaxant activity of adenosine-receptor agonists on guinea-pig isolated aorta precontracted with noradrenaline or phenylephrine

The relaxant effect of adenosine and 5'-(N-ethylcarboxamido)adenosine (NECA) against alpha-adrenoceptor-mediated contractile tone in guinea-pig isolated aortic rings has been examined to determine if this A2B-receptor-mediated relaxation was dependent upon the contracting agent, and whether the contractions were dependent upon intracellular or extracellular calcium. Relaxation responses were consistently greater for aortic rings pre-contracted with phenylephrine (3x10(-6) M) than for rings pre-contracted with noradrenaline (3x10(-6) M). Maximum inhibition by NECA was significantly greater for phenylephrine-contracted aortae than for noradrenaline-contracted (81.9+/-2.8% compared with 25.0+/-1.5%). These differences persisted in the presence of beta- and alpha2-adrenoceptor blockade and could not, therefore, be attributed to stimulation of these receptors by noradrenaline. The ratio of the contractions obtained before and in the presence of adenosine or NECA was compared with the control ratio obtained before and after vehicle. Experiments were performed both in the presence of normal calcium levels and under calcium-free conditions. In normal-calcium medium, NECA inhibited phenylephrine-induced contractions (test ratio, 76.7+/-3.9%; control ratio, 133.1+/-9.8%) to a greater extent than noradrenaline-induced contractions (108.4+/-4.1 and 123.4+/-4.9%); adenosine similarly inhibited phenylephrine-induced contractions more than those induced by noradrenaline. Under calcium-free conditions, adenosine (36.7+/-11.9 and 110.7+/-26.6%) and NECA (55.2+/-9.1 and 87.1+/-14.9%) were only effective against phenylephrine-induced contractions. This suggests that activation of the A2B-receptor by these agonists inhibited intracellular mobilization of calcium for phenylephrine-induced contractions only. The effects on extracellular calcium influx were examined for phenylephrine- and noradrenaline-induced contractions in normal-calcium medium but in the presence of ryanodine to prevent intracellular calcium mobilization. NECA inhibited phenylephrine-induced contractions (77.3+/-12.4 and 111.4+/-9.3%), presumably by interfering with influx of calcium through receptor-operated calcium channels. In contrast, NECA failed to reduce noradrenaline-induced contractions (121.5+/-10.7 and 122.4+/-11.6%), suggesting that the effect on noradrenaline is predominantly via interaction with intracellular calcium. Adenosine was consistently a more effective relaxant than NECA, possibly because of an additional intracellular component of the response. We conclude that adenosine receptor agonists inhibit phenylephrine-induced contractions of guinea-pig aorta more selectively than noradrenaline-induced contractions. A2B-receptor stimulation might reveal a fundamental difference between the modes of contraction elicited by these two alpha-adrenoceptor agonists.     

Total Ischaemic Burden European Trial (TIBET): Effects of ischaemia and treatment with atenolol, nifedipine SR and their combination on outcome in patients with chronic stable angina

OBJECTIVES: To study the relationship between presence or absence of ischaemicevents on Holter monitoring and occurrence of a hard or hard+softendpoint. DESIGN: A randomized double-blind parallel group study of atenolol,nifedipine and their combination, with ambulatory monitoringoff-treatment and after 6 weeks of randomized treatment andprospective follow-up of 2 years on average. SETTING: Europe. SUBJECTS: 682 men and women with a diagnosis of chronic stable anginaand who were not being considered for surgery. MAIN OUTCOME: Hard endpoints were cardiac death, nonfatal myocardial infarctionand unstable angina; soft endpoints were coronary artery bypasssurgery, coronary angioplasty and treatment failure. RESULTS: The study showed no evidence of an association between the presence,frequency or total duration of ischaemic events on Holter monitoring,either on or off treatment, and the main outcome measures. Therewas a non-significant trend to a lower rate of hard endpointsin the group receiving combination therapy. Compliance, as measuredby withdrawal from trial medication, was clearly poorest inthe nifedipine group with similar with drawal rates in the atenololand combination therapy groups. CONCLUSION: The recording of ischaemic events in 48 h Holter monitoringfailed to predict hard or hard+soft endpoints in patients withchronic stable angina.     

Bronchoscopic findings in post-obstructive pulmonary oedema

Purpose

To present the first photographed bronchoscopic findings associated with negative pressure pulmonary oedema (NPPE).

Clinical features

A previously healthy patient underwent anterior C₃–C₄ disc removal and arthrodesis. Following tracheal extubation he developed acute respiratory distress manifested as stridor, tachypnoea, restlessness, and desaturation. Once the trachea was reintubated, he displayed the classic findings of pulmonary oedema. Bronchoscopy was performed to confirm tracheal tube position and to rule out tracheal injury secondary to surgical manipulation. Diffuse punctate haemorrhages were noted throughout the visualised tracheobronchial tree.

Conclusion

We believe that these haemorrhages represent disruption of the bronchial vasculature and may contribute to the clinical presentation of NPPE.     

Spatio-temporal progression of the AEP P300 component using the cortical imaging technique

Summary The cortical imaging technique (CIT), a mathematical method for simulating the potential fields on the surface of the brain, was used to analyze the spatio-temporal progression of the AEP P300 component (as well as the preceding and subsequent N2a and N3 components) from thirty normal adult subjects recorded in a standard oddball paradigm. Comparisons were made between the progressions of the endogenous event-related cognitive potentials and the exogenous stimulus-dependent potentials (Nl component). Cortical imaging results suggest that different and multiple generator sites are involved in the production of exogenous and endogenous evoked responses. We particularly note the asymmetric development of the P300 component and the apparent anterior generator sites for the N2a component. This last result is interesting because the N2a precedes the P300 component and supports an earlier frontal contribution.     

Mind-Body Innovations—An Integrative Care Approach

Integration of behavioral health and medicine has gained increased support recently within the new field of complementary medicine. Providers from both disciplines are acknowledging the mind-body connection and recognizing the value of treating the whole patient through working within an integrative delivery model. This paper describes two treatment programs which were developed using the principles of the mind-body connection and implemented within an integrative setting at a large HMO. The results of research studies are presented and discussed to demonstrate the efficacy of these programs.