The psychopharmacology of European herbs with cognition-enhancing properties

Extensive research suggests that a number of plant-derived chemicals and traditional Oriental herbal remedies possess cognition-enhancing properties. Widely used current treatments for dementia include extracts of Ginkgo biloba and several alkaloidal, and therefore toxic, plant-derived cholinergic agents. Several non-toxic, European herbal species have pan-cultural traditions as treatments for cognitive deficits, including those associated with ageing. To date they have not received research interest commensurate with their potential utility. Particularly promising candidate species include sage (Salvia lavandulaefolia/officinalis), Lemon balm (Melissa officinalis) and rosemary (Rosmarinus officinalis). In the case of sage, extracts possess anti-oxidant, estrogenic, and anti-inflammatory properties, and specifically inhibit butyryl- and acetyl-cholinesterase. Acute administration has also been found to reliably improve mnemonic performance in healthy young and elderly cohorts, whilst a chronic regime has been shown to attenuate cognitive declines in sufferers from Alzheimer's disease. In the case of Melissa officinalis, extracts have, most notably, been shown to bind directly to both nicotinic and muscarinic receptors in human brain tissue. This property has been shown to vary with extraction method and strain. Robust anxiolytic effects have also been demonstrated following acute administration to healthy humans, with mnemonic enhancement restricted to an extract with high cholinergic binding properties. Chronic regimes of aromatherapy and essential oil respectively have also been shown to reduce agitation and attenuate cognitive declines in sufferers from dementia. Given the side effect profile of prescribed cholinesterase inhibitors, and a current lack of a well tolerated nicotinic receptor agonist, these herbal treatments may well provide effective and well-tolerated treatments for dementia, either alone, in combination, or as an adjunct to conventional treatments.     

Endothelial nitric oxide synthase gene/gender interactions and the renal hemodynamic response to angiotensin II

Endothelial function is dependent on the generation of nitric oxide (NO) by the enzyme endothelial NO synthase (eNOS). One functional coding polymorphism of the eNOS gene (G894-->T) is associated with reduced enzyme activity, increased coronary heart disease, and the development of end-stage renal failure. Because gender and renin-angiotensin system activation also play key roles in the development of renal and cardiovascular disease and because NO plays a role in the response to angiotensin II (AngII), it was hypothesized that the eNOS gene G894-->T polymorphism would be a determinant of the systemic and renal vascular response to AngII. Fifty young, healthy, normotensive individuals who were on a controlled sodium and protein diet for 1 wk underwent assessment of BP and renal hemodynamic function at baseline and during AngII infusion (4 ng/kg per min for 45 min). Participants were genotyped for the eNOS gene G894-->T polymorphism and then segregated into groups on the basis of gender and genotype (GG versus GT/TT). Baseline values for renal blood flow, effective renal plasma flow, and GFR were lower in men with the T allele compared with men who were homozygous for the G allele (P = 0.03), but the polymorphism was not associated with renal hemodynamic function in women. The BP responses to AngII were similar in men and women regardless of genotype. Both multivariate linear regression and analysis of covariance (ANCOVA) revealed a relationship between gender and genotype. Men with the GT/TT genotype exhibited a significantly greater decrease in GFR (P = 0.04) in response to AngII than did those with the GG genotype. This association was not observed in women. The eNOS gene G894-->T polymorphism is a determinant of both baseline renal hemodynamic function and the hemodynamic response to AngII in men but not in women.     

Focal and segmental glomerulosclerosis: definition and relevance of a partial remission

Focal and segmental glomerulosclerosis (FSGS) is one of the most common primary glomerular diseases to terminate in ESRD. A complete remission (CR) confers an excellent long-term prognosis, but the quantitative benefits of partial remissions (PR) have not been defined. This study evaluated the rate of renal function decline (slope of creatinine clearance) and renal survival in nephrotic FSGS patients with CR, PR, or no remission. It also examined relapse rate from remission and its impact on outcome. Multivariate analysis included clinical and laboratory data at presentation and over follow-up, BP control, the agents used, and immunosuppressive therapy. The study cohort was 281 nephrotic FSGS patients who had a minimum of 12 mo of observation and were identified from the Toronto Glomerulonephritis Registry. Over a median follow-up of 65 mo, 55 experienced a CR, 117 had a PR, and 109 had no remission. A PR was independently predictive of slope and survival from renal failure by multivariate analysis (adjusted time-dependent hazard ratio, 0.48; 95% confidence interval, 0.24 to 0.96; P = 0.04). Immunosuppression with high-dose prednisone was associated with a higher rate of PR and CR. Relapse from PR was frequent (56%) and associated with a more rapid rate of renal function decline and worse renal survival compared with relapse-free partial remitters. Only female gender and the nadir of proteinuria during remission were associated with a sustained remission. A PR in proteinuria and its maintenance are important therapeutic targets in FSGS, with implications for both slowing progression rate and improving renal survival.     

Patient positioning in anaesthesia

The aim of optimal positioning for surgery is to provide thebest surgical access while minimizing potential risk to thepatient. Each position carries some degree of risk and thisis magnified in the anaesthetized patient who cannot make othersaware of compromised positions. Commonly adopted positions includesupine, lithotomy, Lloyd Davies, lateral, seated and prone.Many of these are modified with the addition of a vertical tilt(Trendelenburg or reverse Trendelenburg). This article addressesthe general complications associated with positioning as wellas the position-specific physiological changes and complications.     

Increased intensity of Ecstasy and polydrug usage in the more experienced recreational Ecstasy/MDMA users: a WWW study

Recreational Ecstasy/MDMA (3,4-methylenedioxymethamphetamine) users often take a variety of psychoactive drugs, but there is little empirical data on how these drug consumption patterns change with greater experience of Ecstasy. The aim of this study was to compare the polydrug usage patterns reported by non-Ecstasy users, novice Ecstasy users, moderate Ecstasy users, and heavy Ecstasy users. In a WWW study of 763 unpaid volunteers, 481 had never taken Ecstasy, whereas 282 reported they had taken it. The Ecstasy users comprised 109 novice users (1-9 occasions), 136 moderate Ecstasy users (10-99 occasions), and 36 heavy Ecstasy users (+100 occasions). Each participant also reported their experience with a range of other psychoactive drugs. The Ecstasy users reported significantly greater psychoactive drug usage than the non-Ecstasy users. The novice, moderate, and heavy Ecstasy users also differed significantly from each other in the use of cocaine, amphetamine, LSD, and psilocybin mushrooms, but not of alcohol, cannabis, or cigarettes/nicotine. Experienced Ecstasy users also took significantly more MDMA tablets on each occasion, and reported a higher maximum weekly intake. The increased use of Ecstasy is associated with more intensive patterns of Ecstasy/MDMA intake, and the greater use of illicit CNS stimulants and hallucinogens, but not of alcohol, nicotine, or cannabis. These results are discussed in the context of cross-tolerance and drug predisposition/preference.     

A randomised crossover trial of post-operative cognitive and psychomotor recovery from benzodiazepine sedation: effects of reversal with flumazenil over a prolonged recovery period

OBJECTIVE: To study the post-operative cognitive and psychomotor recovery from midazolam conscious sedation, after reversal with the benzodiazepine antagonist flumazenil over a prolonged recovery period. DESIGN: A prospective, double-blind, randomised, crossover trial. SETTING: Out-patient Sedation Department, Newcastle Dental Hospital and School METHOD: Eighteen patients, ASA I or II, received midazolam on two separate occasions to undergo equivalent dental treatment. Following treatment patients were reversed with intravenous flumazenil or saline (placebo) at alternate appointments. Assessment of mood and cognitive function was undertaken using a highly sensitive and specific computerised battery of cognitive tests administered by telephone. Cognitive and psychomotor tests were administered prior to sedation and every hour for 6 hours post reversal. RESULTS: Results indicated no significant effect of flumazenil on simple reaction time and choice reaction time but did show a trend of reversing the effects of midazolam on numeric working memory and word recognition. CONCLUSION: The cognitive and psychomotor effects of the sedation were not fully reversed by flumazenil. Cognitive impairments were still present up to 6 hours post-reversal, despite patients appearing clinically more alert. This has important implications for treatment protocols and discharge instructions.     

Use of recombinant human granulocyte-macrophage colony-stimulating factor in autologous marrow transplantation for lymphoid malignancies

The use of recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) following autologous marrow transplantation for lymphoid malignancies was explored in a phase I/II dose escalation study. rhGM-CSF given as a 2-hour infusion daily for 14 days was well tolerated at doses up to 240 micrograms/m2/day. When compared with 86 disease-matched and treatment-matched historical controls, patients receiving greater than or equal to 60 micrograms/m2/day rhGM-CSF recovered neutrophil and platelet counts more rapidly, had fewer days with fever, and were discharged from the hospital sooner.