A comparison of the efficacy and tolerability of moclobemide given as a single daily dose or in three divided doses per day for the treatment of patients with a major depressive episode (DSM-III-R)

This was a prospective, double-blind, randomized, multicenter trial comparing moclobemide once daily (OD) with three times daily (TDS) dosing. The duration of the study was 6 weeks with the initial dose of moclobemide being 450 mg/day (either 450 mg in the morning or 150 mg three times daily). Placebo tablets were used to ensure that the study was double blind. After 2 weeks, the dose could be increased to 600 mg/day if tolerability was acceptable and efficacy was judged insufficient by the investigator. Patients were assessed at baseline and at days 3, 7, 14, 21, 28, and 42. Efficacy was primarily judged on the Hamilton Rating Scale for Depression (HAM-D) (17item). Patients had to score at least 17 to enter the study. Safety and tolerability were judged on reported adverse events, safety parameters, premature withdrawals, and a physicians' global tolerability rating. There were also three secondary efficacy parameters--the Hamilton Rating Scale for Anxiety, Visual Analogue Scales for pain and irritability, and physicians' Clinical Global Impression (CGI). A total of 130 evaluable patients were required to detect a difference of more than 20% (alpha = 0.05 and beta = 0.8) between groups. A total of 189 patients entered the study, and the standard analysis comprised 145 patients. The efficacies between the two dosing regimens as determined by the HAM-D score and from the CGI were found not to differ significantly. For the standard analysis population, there was a reduction in mean HAM-D of 73.8 and 72.9% for the OD and TDS groups, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Vascular and hormonal responses to arginine: provision of substrate for nitric oxide or non-specific effect?

1. The vascular and hormonal effects of L- and D-arginine were compared in healthy subjects and in patients with insulin-dependent diabetes mellitus or untreated essential hypertension. 2. Infusion of L- or D-arginine (40 mumol/l) in the forearm vascular bed, sufficient to increase the local concentration approximately 20-fold, had no effect on blood flow or the vasodilator response to acetylcholine (30 and 100 nmol/min) in patients with insulin-dependent diabetes (n = 7) or essential hypertension (n = 7), or in age- and sex-matched control subjects (n = 7 in both groups). 3. Systemic infusion of 10 g of L-arginine (n = 5) or D-arginine (n = 3) increased plasma concentration of arginine approximately 20-fold without altering supine or erect haemodynamics. Increases in plasma insulin, prolactin and glucagon were seen with both enantiomers. The stereopurity of arginine was confirmed in a cell-culture assay system. 4. We conclude that, in healthy subjects and patients with essential hypertension or insulin-dependent diabetes, synthesis of nitric oxide within the vasculature is not limited by substrate availability. At high concentrations of arginine, non-stereospecific effects, including alterations in hormone concentration, occur. It remains to be determined whether these non-stereospecific hormonal changes might contribute to certain haemodynamic effects of arginine.

Measuring forearm blood flow and interpreting the responses to drugs and mediators

Venous occlusion plethysmography has been widely used to study forearm blood flow. The principle of the technique is straightforward: the rate of swelling of the forearm during occlusion of venous return is used to assess the rate of arterial inflow. Provided that perfusion pressure (arterial blood pressure) remains constant, changes in flow reflect changes in smooth muscle tone in small arteries and arterioles. Local infusion into the brachial artery allows assessment of the direct effect of drugs on vascular tone and has been used to probe the roles of endogenous mediators. The technique is at its most powerful when dose-response relationships to different drugs or mediators within a single study are being compared but can also be used for comparison of responses to drugs between healthy control subjects and patient populations. However, when responses between groups are being compared, it is important to take into account the starting conditions of baseline blood flow and pressure. This article describes venous occlusion plethysmography, discusses the presentation and analysis of data (dose of drug or concentration? forearm blood flow or resistance?), and highlights certain potential problems and limitations of the technique as a means of studying disease states.

Relative potency and arteriovenous selectivity of nitrovasodilators on human blood vessels: an insight into the targeting of nitric oxide delivery

The arteriovenous potency of sodium nitroprusside (SNP), linsidomine (SIN-1) and S-nitrosoglutathione (GSNO) was determined in human capacitance (veins) and resistance (arterioles) vessels in vitro and in vivo and compared with the venoselective nitrovasodilator nitroglycerin (GTN). Concentration-response curves were constructed to GTN, SNP, GSNO and SIN-1 (0.001-10 microM) in preconstricted human saphenous vein and to GTN, GSNO and SIN-1 (0.001-10 microM) in omental resistance vessels. In vivo the dilator responses of the dorsal hand vein and the forearm resistance bed were recorded during local infusions of GTN, SNP, GSNO and SIN-1 (1 pmol/min to 160 nmol/min). SNP and SIN-1 had similar arteriovenous profiles to that of GTN. SNP was equipotent with GTN in arterioles and veins but SIN-1 was 10-fold less potent than GTN in vitro and 100-fold less potent in vivo; the potency of SIN-1 was increased after incubation of saphenous vein with superoxide dismutase. GSNO was equipotent with GTN in arterioles but 10-fold less potent in veins in vitro and in vivo. These results demonstrate that most nitrovasodilators are venoselective irrespective of their mechanism of biotransformation to nitric oxide (NO) and suggests that NO itself might be venoselective in vivo. Endogenous carrier molecules, including glutathione, could alter the vascular profile of NO with physiological and therapeutic implications.

Defective repair of O6-methylguanine-DNA in primary Sjögren's syndrome patients predisposed to lymphoma

OBJECTIVE

To investigate a role for mutation in the aetiogenesis of autoimmune disease by examining levels of repairing enzyme for the promutagenic DNA base lesion, O6-methylguanine, in lymphocyte extracts from patients with autoimmune diseases. We included primary Sjögrens syndrome (PSS) patients because of the additional relevance of their being at increased risk (> 40-fold) of developing lymphoma.

METHODS

Lymphocytes were prepared from patients with PSS (n = 22) (12 with parotid gland enlargement, an indicator of extensive lymphoproliferation), rheumatoid arthritis (n = 12), primary biliary cirrhosis (n = 11), osteoarthritis (n = 12), and healthy individuals (n = 11). MGMT amounts were determined in lymphocyte extracts by direct enzyme assay and expressed in relation to total extract DNA, protein, or cell number.

RESULTS

We found no defect in the repairing methyltransferase enzyme between any of the groups, except in PSS patients at increased risk of developing lymphoma (those with enlarged parotid glands): p < 0.0001 and p = 0.0056, compared with healthy controls and PSS patients without parotid gland swelling, respectively.

CONCLUSIONS

Our findings implicate persistence of O6-methylguanine-DNA in the aetiology of lymphoma associated with PSS, and raise the possibility that an alternative repair process for O6-methylguanine-DNA, nucleotide excision repair, might be defective in autoimmune disease.

Spinal aspergillus abscess in a patient with bronchocentric granulomatosis

Aspergillus fumigatus hyphae is often found in the lung tissue of patients with bronchocentric granulomatosis (BCG). This organism is believed to be one agent responsible for inciting the hypersensitivity response and subsequent development of the characteristic pathology that defines BCG. The definitive etiology of this disease, however, remains conjectural. Corticosteroids represent the mainstay of therapy. The fungi recovered from patients with BCG are considered noninvasive; thus, the risk of fungal invasion secondary to steroid-induced immunosuppression is believed to be negligible. However, we report a case of spinal aspergillus abscess that developed in a patient with BCG subsequent to steroid therapy. This case also highlights the necessity for aggressive medical and neurosurgical intervention to avert the development of neurological sequelae.

Forearm blood flow responses to a nitric oxide synthase inhibitor in patients with treated essential hypertension

OBJECTIVE

There is evidence that basal NO mediated vasodilatation is abnormal in patients with essential hypertension. Studies in animals suggest that treatment of hypertension may restore the nitric oxide system towards normal. The objective of this study was to examine basal nitric oxide mediated vasodilatation in patients with treated essential hypertension.

METHODS

The forearm blood flow response to noradrenaline and NG-monomethyl-L-arginine (L-NMMA), a stereospecific inhibitor of nitric oxide synthesis, was compared in 11 patients with treated essential hypertension and 18 normotensive healthy controls. The results in the treated hypertensive patients were also compared with those in a previously reported group of seven untreated patients with essential hypertension. Drugs were infused locally into the brachial artery and forearm blood flow measured using venous occlusion plethysmography.

RESULTS

In the healthy controls noradrenaline (60, 120, and 240 pmol.min-1) and L-NMMA (1, 2, and 4 mumol.min-1) produced similar reductions in resting forearm blood flow. In the patients with treated essential hypertension, at the same doses, noradrenaline and L-NMMA also produced similar reductions in forearm blood flow. There was no significant difference in the response to either noradrenaline or L-NMMA between the healthy controls and the treated hypertensive patients. There was also no significant difference in the response to noradrenaline or L-NMMA between the treated patients and the patients with untreated essential hypertension. However, the response to L-NMMA in all subjects correlated significantly with blood pressure, such that the responses in the treated patients lay between those of the healthy controls and the untreated patients.

CONCLUSIONS

Basal nitric oxide mediated vasodilatation appears to be a continuum that varies with blood pressure. Reduction in blood pressure with medication moves the L-NMMA response nearer to that seen in healthy subjects. These results suggest that treatment of hypertension may restore NO mediated vasodilatation towards normal.

Coordinating locally 'owned' treatment guidelines

South West Thames Regional Health Authority established and commissioned a regional guidelines unit to coordinate the introduction of a set of treatment guidelines on the management of common medical emergencies into all the acute intaking National Health Service (NHS) hospitals throughout the region. All hospitals were offered a set of template guidelines to be used at their discretion for producing their own customised equivalent. They were also offered full typing and production facilities, together with printing costs if publication was achieved by a target deadline (1 August 1993). In 11 of the 14 NHS hospitals guidelines were available to hospital staff by the target deadline, and one set was produced for a non-NHS hospital. In two hospitals the target date was not met, and one other declined to take part. As part of the project the unit assessed the extent to which the published guidelines were adapted to meet the requirements of each individual hospital. The template offered guidelines on 34 topic titles. No hospital used all core titles of the original template; titles were omitted or replaced in some, and added in others. Where the original guideline titles were used, there was almost always some customisation--changes in sentence structure, names or contact numbers, alterations in drugs and doses or the addition or omission of entire sections. By using an established resource, sets of customised, locally determined treatment guidelines were introduced with relative ease into most of the acute hospitals in a UK health region.

Prealbumin and lipoprotein(a) in hemodialysis: relationships with patient and vascular access survival

The high morbidity and mortality of hemodialysis patients has led to a search for early markers of risk. Because cardiovascular and nutritional risk are prevalent in this population, we examined the prognostic value of the serum levels of two markers of risk in the general population: (1) lipoprotein(a) [Lp(a)], a low-density lipoprotein-like particle linked to myocardial infarction and coronary bypass stenosis, and (2) prealbumin, a marker of visceral protein status, with a shorter half-life than that of serum albumin. Baseline demographics, clinical information, dialysis prescription, and serum biochemistry measurements of 125 hemodialysis patients followed for up to 14 months were recorded on enrollment. Vascular access events and deaths were recorded prospectively. The hypotheses tested were that increased serum Lp(a) levels would predict cardiovascular mortality and vascular access stenosis and thrombosis, and that reduced serum prealbumin levels would predict mortality risk independently of established risk predictors. Cross-sectional analysis of serum Lp(a) demonstrated a skewed distribution with a median value of 38.3 mg/dL (upper tertile, > or = 57 mg/dL). Lipoprotein(a) was significantly higher in black patients (P < 0.001) and was significantly correlated (P < 0.005) with total cholesterol and apoprotein B (apoB), but not with a history of prior coronary disease. Serum prealbumin was strongly correlated with serum albumin (r = 0.49, P < 0.001). However, prealbumin correlated (P < 0.001) more strongly with other serum nutrition markers (total cholesterol, apoB, creatinine, urea) than did serum albumin. Fourteen-month cumulative survival was 80%. Age, diabetes, and serum levels of albumin, prealbumin, creatinine, total cholesterol and apoB, but not Lp(a), were correlated with survival in univariate analysis. Using the Cox proportional hazards model, independent predictors of mortality risk were prealbumin less than 15 mg/dL versus higher values (relative risk [RR] = 4.48, P < 0.01), apoB (RR = 0.97 per 1 mg/dL increase, P < 0.02), creatinine less than 10 mg/dL versus higher values (RR = 3.51, P = 0.04), and age (RR = 1.04 per year, P = 0.10). Thirty-eight patients experienced at least one vascular access thrombosis (n = 33) or stenosis (n = 5) during the study. Patients with Lp(a) > or = 57 mg/dL had decreased vascular access event-free survival compared with patients with Lp(a) less than 57 mg/dL (56% v 73%, P < 0.06). This trend was increased in magnitude and statistically significant for white and Hispanic patients (31% v 79%, P < 0.01).(ABSTRACT TRUNCATED AT 400 WORDS)