On the question of an electrokinetic requirement for phospholipase C action

The phospholipase C of clostridium welchii (alpha toxin) has an absolute requirement for trace quantities of Ca2+. It attacks pure phosphatidylcholine particles (smectic mesophases) having a close-packed bilayer structure only when their surface zeta potential is made positive by the addition of certain divalent ions (e.g., Ca2+) to the aqueous phase or by the presence of low concentrations of long chain cations to the lipid. Alternatively, if the rotational freedom of individual phospholipid molecules is increased by the insertion of short n-alkanols (e.g., hexanol) into the bilayer or when a monolayer of the substrate at an air/water interface is expended, enzymic hydrolysis can occur without any requirement for a net postive charge on the surface.     

Absence of tonic electromyographic activity during sleep in normal and spastic nonmimetic skeletal muscles in man

An electromyographic study of nonmimetic skeletal muscles was carried out in 8 normal adults and 4 patients with spastic hemiparesis during all stages of sleep for a total of 21 nights. All normal subjects showed absence of tonic electromyographic activity in all nonmimetic skeletal muscles in all stages of sleep. Also, during quiet, relaxed wakefulness, tonic muscle discharges disappeared in the normal subjects. Three patients with upper motor neuron spasticity demonstrated results during sleep similar to those obtained in the normal subjects. In the fourth patient, tonic muscle discharges persisted into stage 2 non-REM sleep, disappeared within 30 to 240 seconds following the onset of stage 2 sleep, and were absent during stages 3 and 4 sleep and REM sleep.     

Central poststroke pain and Wallenberg''s lateral medullary infarction: frequency, character, and determinants in 63 patients

BACKGROUND: Questionnaire-based surveys from several countries have consistently detected adverse health associated with home dampness and mould growth. METHODS: To test the validity of questions commonly used to indicate the presence of indoor mould, questionnaires were administered in 403 homes where dust samples were taken for viable fungi and air samples for ergosterol. RESULTS: Geometric mean concentrations of the total viable fungi were 255 (SE 116) x 10(3) CFU/g when mouldy odours were reported and 155 (SE 55) when odours were not reported (P = 0.01). Similarly, reported water damage was associated with a 50% increase (P = 0.06). Geometric mean concentrations of the predominantly indoor-source fungi, Aspergillus plus Penicillium, were twice as high when mould or mildew was reported than when not mentioned (P = 0.01). The presence of reported mould or water damage was unrelated to the presence of detectable levels of ergosterol. There was evidence for reporting bias: in the presence of low concentrations of viable fungi in dust, respondents reporting allergies were more likely to report visible mould growth (odds ratio [OR] = 1.8, 95% confidence interval [CI]: 0.9-3.5, P = 0.10. In the presence of elevated concentrations of dust fungi, respondents who smoked were less likely to report visible mould growth, (OR = 0.4, 95% CI: 0.2-0.7, P = 0.005). CONCLUSIONS: Reported mould, water damage, and mouldy odours were associated with elevated levels of indoor fungi. However, inaccuracy was high and there was evidence of a systematic reporting bias. Future research should concentrate on developing accurate objective measures of exposure to fungi, and then use this information to develop valid questionnaires. Currently, objective measures not questionnaires, are recommended to clarify the health effects of indoor fungi.     

Developments in the treatment of alcoholism

The treatment of alcoholism has changed during the past 2 decades. Notable developments have occurred in pharmacotherapy, psychotherapy, and health-care delivery. A better understanding of the biologic basis for addiction has led to clinical trials of medications that target neuroreceptors. One such medication is the opiate antagonist naltrexone, which decreases the craving for alcohol. Psychosocial interventions continue to be the mainstay of alcohol treatment programs. The efficacy of three different therapies was demonstrated in a study called Project MATCH (Matching Alcoholism Treatments to Client Heterogeneity). This study, however, did not prove the patient-treatment "matching" hypothesis. In addition to therapies provided by addiction specialists, interest is growing in the use of brief motivational techniques in primary-care settings. As the field of addiction responds to an unfolding health-care delivery system, a broader range of treatment options in conjunction with a greater opportunity to individualize patient care is evolving.     

The effect of angiotensin II on platelet intracellular free magnesium and calcium ionic concentrations in essential hypertension

OBJECTIVE: To assess the effects of angiotensin II on intracellular free Mg2+ and Ca2+ concentrations in platelets from normotensive and hypertensive subjects. DESIGN AND METHODS: Seventeen normotensive, 25 untreated hypertensive and 18 treated hypertensive patients were studied. Intracellular Mg2+ concentrations were measured with the fluorescent dye mag-fura-2-acetyoxymethylester (AM) and intracellular Ca2+ concentrations with the fluorescent dye fura-2AM under basal conditions and after stimulation by angiotensin II, saralasin (angiotensin II antagonist), arginine vasopressin and endothelin-1. The effects of increased extracellular Mg2+ concentrations on intracellular Mg2+ and Ca2+ concentrations were also determined. RESULTS: The intracellular basal Ca2+ concentration was significantly higher in the untreated hypertensives compared with the normotensives and treated hypertensive subjects (150 +/- 14 nmol/l versus 120 +/- 17 nmol/l for normotensives and 124 +/- 8 nmol/l for treated hypertensives). The basal intracellular Mg2+ concentration was significantly lower in the untreated hypertensive compared to the normotensive and treated hypertensive groups (0.37 +/- 0.08 mumol/l versus 0.58 +/- 0.09 mumol/l for normotensives and 0.52 +/- 0.11 mumol/l for treated hypertensives). In the hypertensive groups, inverse correlations were found between intracellular Ca2+ and intracellular Mg2+ concentrations (r = -0.44, P < 0.05) and between intracellular Mg2+ and diastolic blood pressure (r = -0.35, P < 0.05), while a positive correlation was found between intracellular Ca2+ and systolic blood pressure (r = 0.41, P < 0.05). Exposure of the platelets to 1 nmol/l angiotensin II significantly increased intracellular Ca2+ and significantly decreased intracellular Mg2+ concentrations in all three groups. The angiotensin II-evoked effect on intracellular Ca2+ was exaggerated in the untreated hypertensives and blunted in the treated patients (basal versus stimulated: 150 +/- 14 versus 217 +/- 20 nmol/l in untreated hypertensives; 124 +/- 8 versus 140 +/- 10 nmol/l in treated hypertensives). Saralasin (0.1 mumol/l) abolished the effects of angiotensin. Arginine vasopressin (1 mumol/l) increased the intracellular Ca2+ concentration, whereas endothelin-1 (1 nmol/l) had no significant effect on either intracellular Ca2+ or intracellular Mg2+. Increasing extracellular Mg2+ concentrations led to significant reductions in intracellular Ca2+ concentrations in all groups and a significant elevation of the intracellular Mg2+ concentration in the untreated hypertensive patients only. CONCLUSIONS: These data demonstrate a relationship between angiotensin II and intracellular magnesium and calcium. In hypertension, angiotensin II-stimulated calcium responses may be related to simultaneously decreased intracellular magnesium concentrations.     

Subconjunctival mitomycin C for the treatment of ocular cicatricial pemphigoid

PURPOSE: The authors performed a prospective evaluation of the efficacy of treating ocular cicatricial pemphigoid (OCP) with subconjunctival mitomycin C. DESIGN: Unmasked, prospective, internally controlled case series. METHODS: Patients were eligible for treatment with subconjunctival mitomycin C under three criteria: (1) significant complications of systemic immunosuppressant therapy; (2) markedly asymmetric conjunctival disease; and (3) end-stage OCP. All patients received monocular subconjunctival injections of 0.25 ml of 0.2 mg/ml mitomycin C to both the superior and inferior bulbar conjunctivae in the eye with the more severe disease. RESULTS: Nine eyes of nine patients (mean age, 74 years) were treated with subconjunctival mitomycin C to the more-involved eye and were followed for a mean of 23.5 months (range, 12-40 months). Eight of nine patients showed quiescence of their OCP in the treated eye based on serial evaluation of conjunctival cicatrization and grading of conjunctival erythema. Five of the nine untreated eyes showed progression of the conjunctival disease. One patient required concomitant systemic immunosuppressive therapy after subconjunctival mitomycin C. Two patients underwent successful visual rehabilitative surgery in the mitomycin C-treated eye. CONCLUSION: The use of subconjunctival mitomycin C may be effective in preventing progression of conjunctival cicatrization and erythema in patients with OCP. No complications of mitomycin C treatment were noted. Long-term follow-up and further investigation into the efficacy of subconjunctival mitomycin C in the management of OCP is warranted.