Effects of Hypericum extract on the acetylcholine release: a loose patch clamp approach.

The St. John's Wort (Hypericum perforatum) extract (Hp) represents one of the most useful natural therapeutic agents in the treatment of moderate and mild depression. The antidepressant effects of Hp are different, by a molecular mechanism point of view, when compared to those of other antidepressant drugs and, we think, a further pharmacological characterization is needed. It is suggested that the neurochemical effects of Hp could be bind either to its activity on the uptake of some mediators in the central nervous system or to the inhibition of some enzymatic activity at the receptor level. The present study carried out with the loose patch clamp (LPC) in the mouse neuromuscular junction, indicates a potentiation of the acetylcholine (ACh) action at the mouse neuromuscular junction. The spontaneous release of ACh was unaffected by Hp indicating that neither presynaptic nor postsynaptic function are modified by Hp. Indeed, both the frequency and the amplitude of the miniature end-plate currents (mepcs) were unmodified by Hp. Furthermore, the mepcs decay time (tau), i.e. the apparent cholinergic channel life time, was significantly increased after Hp treatment. The other parameter affected was the amplitude of the evoked end-plate currents (epcs) which was constantly and in a dose dependent manner increased by Hp. These findings suggest a possible action of Hp on the acetylcholinesterase (AChE) in terms of a reduction of the degradation rate of ACh.     

Cardiovascular risk in hypertensive patients: results of the Pandora project

BACKGROUND: The aim of the Pandora project is to collect epidemiological information, check diagnostic and therapeutic pathways, and assess outcomes in a large hypertensive population. This report presents the results on patients enrolled in the study between 1997-1999. METHODS: Twenty-one general practitioners working in the Ravenna Local Health Service took part in the study. They were supplied with IBM compatible PCs and were trained to enter the patient's data (age, gender, familiarity for cardiovascular diseases, smoking, hospitalisations for cardiovascular disorders, diabetes, blood pressure, total cholesterolemia, creatininemia, antihypertensive therapy) on So.Ge.Pa. software. Cardiovascular risk factors were assessed according to the WHO - ISH joint committee recommendations. RESULTS: 2,608 treated hypertensive patients were enrolled, 65% of whom showed inadequate blood pressure control. The prevalence of inadequate BP control was higher in patients on multiple-drug antihypertensive therapy compared with those on monotherapy (71.9% vs. 47.9%), in older than in younger patients (70.7% vs. 56.1%) and in patients with three cardiovascular risk factors, or diabetes, or affected target organs, compared to those with two or less risk factors (72.4% vs. 63.3%), (p < 0.001 for all). 63.6% of patients were at risk for age, 36.6% for family history of cardiovascular diseases and 31.7% for severe hypercholesterolemia. CONCLUSIONS: BP control was inadequate in a large percentage of patients, but it was particularly unsatisfactory in the elderly and in patients with high cardiovascular risk. A cluster of cardiovascular risk factors was found in both adequately and inadequately controlled hypertensive patients.     

Sleep-related breathing impairment in myotonic dystrophy

Summary Respiratory failure has been described in myotonic dystrophy; it worsens during sleep but its central or peripheral origin has yet to be determined. Moreover, patients may present severely disturbed sleep and daytime somnolence. Eight patients with mild to moderate myotonic dystrophy were studied to assess breathing function while awake and during sleep by means of the pulmonary function tests, nocturnal polysomnographic examination and the multiple sleep latency test (MSLT). Three patients had restrictive respiratory defects; none had signs of airway obstruction. All patients had very disrupted nocturnal sleep. Of six patients who underwent the MSLT only two showed a mild tendency to sleep during the day. Six patients had pathological apnoea plus hypopnoea index [(A+H)I] and there was a prevalence of central apnoeas. The apnoeas occurred while resting but awake and throughout all sleep stages. Only two patients (the ones with the least vital capacity) had episodes of progressive oxygen desaturation during rapid eye movement sleep, similar to those found in other restrictive disorders and in chronic obstructive pulmonary disease. It is concluded that the breathing pattern characteristic of our myotonic dystrophy patients was the occurrence of central apnoeas both at rest while awake and during sleep.     

Plasma renin activity in essential hypertension

Summary A study of the frequency distribution of plasma renin activity (PRA) in 123 patients with essential hypertension (EH) produced no evidence of a distinct subpopulation with low renin levels, whether the samples were taken from supine or upright patients. Applying an arbitraty classification criterion, however, low PRA levels were found in 30.1% of patients. There were no significant differences in mean blood pressure, 24-h sodium excretion, and age when groups with low, normal or high PRA levels were compared. The incidence of PRA hyporesponsiveness was similar in the three groups of patients, but increased with age. In the female there was a preponderance of low PRA levels. It is concluded that EH with low PRA levels is not a separate diagnostic entity and, when PRA is low in a hypertensive subject, the possible effects of age, blood pressure, and sex ought to be taken into account before other causes of low PRA are postulated.     

The PANDORA project: results of the cost of illness analysis

AIMS: To evaluate the cost of illness from hypertension for the Italian National Health System (NHS). METHODS AND RESULTS: A prospective analysis was carried out on clinical and economic data recorded in the general practitioners' (GPs) database. Twenty-one GPs working in the Ravenna area in Italy took part in the project on a voluntary basis. The study included 1047 hypertensive patients enrolled between 1 June and 31 December 1997 and continued for 365 days from the date of enrolment. The following costs were calculated: antihypertensive drugs, laboratory tests and instrumental procedures, GP visits for blood pressure control, specialist visits, casualty visits, hospitalisation due to cardiovascular problems. In the whole sample, the most relevant cost is due to antihypertensive drugs (42.7%), followed by hospital admission (28.4%), GP visits (15.1%) and tests (10.6%). The total mean cost was significantly lower in incident (no previous treatment) than in prevalent patients (already treated) (457 512 vs 725 573 Italian Lira (ITL), P < 0.05) and in older rather than in younger patients (1171 410 vs 796 452 (ITL) P < 0.05). (In the text the equivalent is given in Euros, Pounds Sterling and US dollars). CONCLUSION: Our study should be considered as preliminary, nevertheless it could represent a step towards the evaluation of the true cost of hypertension.     

Prevalence and prognostic role of cardiovascular complications in patients with exacerbation of chronic obstructive pulmonary disease admitted to Italian respiratory intensive care units.

BACKGROUND: Cardiovascular complications are frequently observed in patients with chronic obstructive pulmonary disease (COPD) admitted to respiratory intensive care units and may affect the prognosis. The aims of this study were to evaluate a) the prevalence of cardiovascular complications in patients with COPD exacerbation admitted to respiratory intensive care units, b) which parameters detected at admission were predictive of cardiovascular complications, and c) the prognostic role of cardiovascular complications. METHODS: A series of 278 consecutive patients with COPD admitted to 11 Italian respiratory intensive care units between November 1997 and January 1998 has been retrospectively analyzed. All cardiovascular complications were recorded. RESULTS: One hundred and ten patients (39.6%) developed cardiovascular complications: congestive heart failure 49 (17.6%), arrhythmias 40 (14.4%), shock 13 (4.7%), and hypotension 11 (4%). Multivariate analysis showed that the APACHE II score, ECG abnormalities (supraventricular ectopic beats, right and/or left ventricular hypertrophy) and digoxin therapy were independent predictors of cardiovascular complications. The overall mortality was 9% being 4.7% in patients without and 15.5% in patients with cardiovascular complications (p = 0.0044). Multivariate analysis showed that the APACHE II score, respiratory rate, pneumonia and end-stage respiratory diseases were independent predictors of mortality. CONCLUSIONS: Cardiovascular complications occurred in many patients with COPD exacerbation admitted to respiratory intensive care units, and identify a subset of patients with higher mortality.     

Evidence of parasympathetic activity of the angiotensin converting enzyme inhibitor, captopril, in normotensive man

Captopril (50 mg orally) produced a significant fall in systolic and diastolic blood pressure in six normotensive sodium replete subjects, without a rise in heart rate. On captopril, there was no change in the expected normal increase in heart rate on standing. Supine plasma noradrenaline was not reduced by captopril and normal postural increases were maintained. Atropine (0.04 mg/kg i.v.) reduced the difference in blood pressure change between captopril and placebo. Facial immersion in water produced a bradycardia. This change was abolished by atropine and attenuated both by captopril and edrophonium (10 mg i.v.), a cholinesterase inhibitor. Lying down after 6 min standing produced an immediate transient tachycardia, which was abolished by atropine and attenuated by captopril. Blood pressure and heart rate rose after a cold pressor test on both captopril and placebo. The tachycardia during the Valsalva manoeuvre was inhibited by edrophonium and to a lesser extent by captopril. The effects of captopril and edrophonium were additive. Parasympathetic activity of captopril may contribute to its haemodynamic profile.     

Prevalence of hypertension in patients on peritoneal dialysis: results of an Italian multicentre study.

BACKGROUND: The tenet that peritoneal dialysis is capable of either normalizing or improving blood pressure control in uraemic patients is based on outdated or monocentric experiences. Therefore, we assessed the prevalence of hypertension and the efficacy of antihypertensive therapy in a large, multicentric cohort of patients on peritoneal dialysis. METHODS: Twenty seven out of the 50 centres belonging to the Italian Co-operative Peritoneal Dialysis Study Group took part in the study. The main patient selection criteria were: peritoneal dialysis therapy for at least 3 months and no peritonitis or changes in dialysis technique for at least 1 month. Clinical blood pressure was measured according to WHO/ISH guidelines. Ambulatory blood pressure monitoring was carried out using a SpaceLabs 90207 recorder. Hypertension was defined according to WHO/ISH criteria and staged according to the criteria of the Joint National Committee on Detection, Evaluation and Treatment of High Blood Pressure (JNC), 5th Report. Ambulatory blood pressure monitoring recordings were used to evaluate white-coat hypertension, blood pressure load and the dipping phenomenon. RESULTS: Five hundred and four subjects were evaluated. Hypertension was prevalent in 88.1% of the population, and 362 out of 444 hypertensive patients were on antihypertensive therapy. JNC staging revealed that 188 patients had moderate to severe hypertension. Blood pressure load was pathological in 77.3% of the patients receiving antihypertensive treatment. White-coat hypertension was identified in 9.1% of the hypertensive patients not on antihypertensive therapy, and 53.1% of the patients were non-dippers. CONCLUSIONS: The study demonstrates that hypertension is a dramatic, unsolved problem in uraemic patients treated with peritoneal dialysis, and casts doubts on the effectiveness of our current peritoneal dialysis strategies and pharmacological management of hypertension.     

Pulmonary vascular reactivity and hemorheology in patients with chronic cor pulmonale: Responses to pentoxifylline at rest and during exercise

Summary This study was carried out in order to evaluate changes in pulmonary vascular reactivity and in hemorheology induced by pentoxifylline infusion (100 mg) at rest and during standardized exercise in patients with chronic cor pulmonale secondary to chronic obstructive pulmonary disease. The administration of pentoxifylline at rest was associated with reduction in mean pulmonary artery pressure (p<0.01), pulmonary vascular resistance (p<0.01) and right ventricular stroke work index (p<0.02). Standard exercise performed after pentoxifylline infusion was also associated with significant reduction in mean pulmonary artery pressure and pulmonary vascular resistance. Rheologic tests showed less evident changes. Our data suggest that pentoxifylline significantly improves pulmonary hemodynamics at rest and partly reverses its changes, after exercise, in patients with chronic obstructive pulmonary disease.     

End-of-life decision-making in respiratory intermediate care units: a European survey.

A survey was performed on behalf of the European Respiratory Society to assess end-of-life practices in patients admitted to European respiratory intermediate care units and high dependency units over a 6-month period. A 33-item questionnaire was sent by e-mail to physicians throughout Europe and the response rate was 28 (29.5%) out of 95. A total of 6,008 patients were admitted and an end-of-life decision was taken in 1,292 (21.5%). The mortality rate in these patients was 68% (884 out of 1,292). The patients received similar proportions of withholding of treatment (298 (23%) out of 1292), do-not-resuscitate or do-not-intubate orders (442 (34%) out of 1,292) and noninvasive mechanical ventilation as the ceiling of ventilatory care (402 (31%) out of 1,292). Withdrawal of therapy was employed in 149 (11%) out of 1,292 patients and euthanasia in one. Do-not-intubate/do-not-resuscitate orders were more frequently used in North compared with South Europe. All of the 473 competent patients directly participated in the decision, whereas, in 722 (56%) out of 1,292 cases, decision-making was reported to be shared with the nurses. In European respiratory intermediate care units and high dependency units, an end-of-life decision is taken for 21.5% of patients admitted. Withholding of treatment, do-not-intubate/do-not-resuscitate orders and noninvasive mechanical ventilation as the ventilatory care ceiling are the most common procedures. Competent patients are often involved, together with nurses.