Methanolic extract of Hibiscus asper leaves improves spatial memory deficits in the 6-hydroxydopamine-lesion rodent model of Parkinson's disease

Ethnopharmacological relevance

While the Hibiscus asper Hook.f. (Malvaceae) is a traditional herb largely used in tropical region of the Africa as vegetable, potent sedative, tonic and restorative, anti-inflammatory and antidepressive drug, there is very little scientific data concerning the efficacy of this.

Aim of the study

We investigated antioxidant activity and the effects of methanolic extract of Hibiscus asper leaves on neurological capacity of male Wistar rats subjected to unilateral 6-hydroxydopamine (6-OHDA)-lesion.

Materials and methods

Two model systems: 2,4-dinitrophenyl-1-picryl hydrazyl (DPPH) radical scavenging activity and β-carotene bleaching inhibition assay were used to measure the antioxidant activities of the plan extract. We also investigated the neuroprotective effect of methanolic extract of Hibiscus asper leaves (50 and 100 mg/kg) in male Wistar rats subjected to unilateral 6-hydroxydopamine (6-OHDA)-lesion rat model.

Results

Methanolic extract of Hibiscus asper leaves showed potent antioxidant and free radical scavenging activity. Chronic administration of methanolic extract (50 and 100 mg/kg, i.p., daily, for 7 days) significantly reduce anxiety-like behavior and inhibit depression in elevated plus-maze and forced swimming tests, suggesting anxiolytic and antidepressant activity. Also, spatial memory performance in Y-maze and radial arm-maze tasks was improved, suggesting positive effects on memory formation.

Conclusions

Taken together, our results suggest that the methanolic extract of Hibiscus asper leaves have antioxidant effects and might provide an opportunity to management neurological abnormalities in Parkinson's disease conditions.     

Comparison of methods and sampling designs to test for association between rare variants and quantitative traits

Genome‐wide association studies succeeded in finding genetic variants associated with various phenotypes, but a large portion of the predicted genetic contribution to many traits remains unknown. One plausible explanation is that some missing variation is due to rare variants. Latest sequencing technology facilitates the investigation of such rare variants, but their statistical analysis remains challenging. For quantitative traits, a commonly used approach is to contrast the frequency of putatively functional rare variants between subjects in the two tails of the trait distribution. The contrast is usually performed by Fisher's exact or similar test. These tests are conservative as they discard trait rank information and are most useful under the unrealistic homogeneity assumption (i.e., variants have similar effects). We propose, and investigate via simulations, various designs for resequencing studies and statistical methods that incorporate information about rank, predicted function and allow for heterogeneity of effects. We propose designs which accommodate heterogeneity by sequencing both tails and the middle of the trait and novel statistical tests for trend, for heterogeneity and for a combination of the two. The conclusions of the simulations are four fold: (1) sequencing both tails and the middle of the trait distributions is desirable when heterogeneity is suspected, (2) trend and heterogeneity statistics should be used alongside other methods, (3) using rank information improves power over Fisher's exact test when the number of rare variants is not very large and (4) due to high misclassification rates, incorporating current predictions of a variant's function does not improve power. Genet. Epidemiol. 35: 226‐235, 2011. © 2011 Wiley‐Liss, Inc.     

Virtual reality measures in neuropsychological assessment: a meta-analytic review

Objective: Virtual reality-based assessment is a new paradigm for neuropsychological evaluation, that might provide an ecological assessment, compared to paper-and-pencil or computerized neuropsychological assessment. Previous research has focused on the use of virtual reality in neuropsychological assessment, but no meta-analysis focused on the sensitivity of virtual reality-based measures of cognitive processes in measuring cognitive processes in various populations. Method: We found eighteen studies that compared the cognitive performance between clinical and healthy controls on virtual reality measures. Results: Based on a random effects model, the results indicated a large effect size in favor of healthy controls (g = .95). For executive functions, memory and visuospatial analysis, subgroup analysis revealed moderate to large effect sizes, with superior performance in the case of healthy controls. Participants’ mean age, type of clinical condition, type of exploration within virtual reality environments, and the presence of distractors were significant moderators. Conclusions: Our findings support the sensitivity of virtual reality-based measures in detecting cognitive impairment. They highlight the possibility of using virtual reality measures for neuropsychological assessment in research applications, as well as in clinical practice.     

Falls and depression in older people

BACKGROUND: Depression is one of the most common risk factors for falls, but links between falls and depression are still unclear. Few studies have examined the relationship between depression and gait alteration, which may increase the risk of fall. OBJECTIVE: This study aims to assess a possible relationship between depression, postural and gait abnormalities, and falls. METHODS: We conducted a 1-year prospective study on patients >/=70 years who were admitted to a geriatric unit for 'spontaneous' unexplained falls. Patients were tested for depression using the 30-item Geriatric Depression Scale (GDS). Their motor performances were assessed using the Mini Motor Test (MMT), which is an easy direct-observation test, validated in France, for assessment of frail old people who present with severe postural and gait impairment. This scale is composed of 4 categories of items: (1) abilities in bed; (2) quality of the sitting position; (3) abilities in the standing position, and (4) quality of gait. RESULTS: Sixty-nine patients were included. Depression was found in 46 patients (66.7%). The MMT score was higher in the non-depressed fallers (NDF) group (GDS 10; p < 0.05). The 2 groups were compared for each of the 4 items of the MMT: the difference between the DF and NDF groups was mainly explained by the impairment of postural abilities in the standing position. CONCLUSIONS: Our results support the idea that depression is associated with postural abnormalities in the standing position, which may predispose to falls. In clinical practice, more attention should be given to old fallers concerning diagnosis and treatment of associated depression.     

Fluoride Treatment and In Vitro Corrosion Behavior of Mg-Nd-Y-Zn-Zr Alloys Type

Fluoride conversion coatings on Mg present many advantages, among which one can find the reduction of the corrosion rate under “in vivo” or “in vitro” conditions and the promotion of the calcium phosphate deposition. Moreover, the fluoride ions released from MgF₂ do not present cytotoxic effects and inhibit the biofilm formation, and thus these treated alloys are very suitable for cardiovascular stents and biodegradable orthopedic implants. In this paper, the biodegradation behavior of four new magnesium biodegradable alloys that have been developed in the laboratory conditions, before and after surface modifications by fluoride conversion (and sandblasting) coatings, are analyzed. We performed structural and surface analysis (XRD, SEM, contact angle) before and after applying different surface treatments. Furthermore, we studied the electrochemical behavior and biodegradation of all experimental samples after immersion test performed in NaCl solution. For a better evaluation, we also used LM and SEM for evaluation of the corroded samples after immersion test. The results showed an improved corrosion resistance for HF treated alloy in the NaCl solution. The chemical composition, uniformity, thickness and stability of the layers generated on the surface of the alloys significantly influence their corrosion behavior. Our study reveals that HF treatment is a beneficial way to improve the biofunctional properties required for the studied magnesium alloys to be used as biomaterials for manufacturing the orthopedic implants.     

The trans-Golgi network-associated human ubiquitin-protein ligase POSH is essential for HIV type 1 production

HIV type 1 (HIV-1) was shown to assemble either at the plasma membrane or in the membrane of late endosomes. Now, we report an essential role for human ubiquitin ligase POSH (Plenty of SH3s; hPOSH), a trans-Golgi network-associated protein, in the targeting of HIV-1 to the plasma membrane. Small inhibitory RNA-mediated silencing of hPOSH ablates virus secretion and Gag plasma membrane localization. Reintroduction of native, but not a RING finger mutant, hPOSH restores virus release and Gag plasma membrane localization in hPOSH-depleted cells. Furthermore, expression of the RING finger mutant hPOSH inhibits virus release and induces accumulation of intracellular Gag in normal cells. Together, our results identify a previously undescribed step in HIV biogenesis and suggest a direct function for hPOSH-mediated ubiquitination in protein sorting at the trans-Golgi network. Consequently, hPOSH may be a useful host target for therapeutic intervention.     

Noncardiac chest pain

GOALS: Review of research directions in the etiology, evaluation, and treatment of patients with noncardiac chest pain. The author proposes a combined practical approach to noncardiac chest pain that incorporates these findings, which is useful in a clinical practice setting. BACKGROUND: Several major schools of thought have emerged in the etiology of noncardiac chest pain: acid reflux, motor disorder, altered pain threshold/hypersensitivity, and association with psychiatric dysfunction. There is significant overlap among these. Occult gastroesophageal reflux disease (GERD) is more common than motor disorders and is found in 30% to 40% of these patients; a subset has hypersensitivity, with a normal pH profile. Esophageal motility testing and endoscopy have a more limited role than 24-hour pH testing. Impedance planimetry and balloon sensory provocative testing remain research tools. Provocative testing with hydrochloric acid or edrophonium is less helpful than pH monitoring. Gastroesophageal reflux disease-induced chest pain requires high-dose long-term proton pump inhibitors (PPIs): at least 4 to 8 weeks. Psychotropics are superior to placebo, both in patients with and without psychiatric dysfunction. RESULTS: The author found combined PPIs and psychotropics helpful in patients with esophageal hypersensitivity and GERD, although supporting data is scant. CONCLUSIONS: A brief 1-week high-dose PPI challenge, i.e., omeprazole test, may be cost-effective in a primary care setting. However, this approach may not be useful in a referral setting, where pH data and diary assessment of associated symptoms provide useful management help. A behavioral model approach, with early emphasis on patient education, integrated with physiologic data helps the most.     

Challenges in the diagnosis and management of acromegaly: a focus on comorbidities

Introduction

Acromegaly is a rare, insidious disease resulting from the overproduction of growth hormone (GH) and insulin-like growth factor 1 (IGF-1), and is associated with a range of comorbidities. The extent of associated complications and mortality risk is related to length of exposure to the excess GH and IGF-1, thus early diagnosis and treatment is imperative. Unfortunately, acromegaly is often diagnosed late, when patients already have a wide range of comorbidities. The presence of comorbid conditions contributes significantly to patient morbidity/mortality and impaired quality of life.

Methods

We conducted a retrospective literature review for information relating to the diagnosis of acromegaly, and its associated comorbidities using PubMed. The main aim of this review is to highlight the issues of comorbidities in acromegaly, and to reinforce the importance of early diagnosis and treatment.

Findings and conclusions

Successful management of acromegaly goes beyond treating the disease itself, since many patients are diagnosed late in disease evolution, they present with a range of comorbid conditions, such as cardiovascular disease, diabetes, hypertension, and sleep apnea. It is important that patients are screened carefully at diagnosis (and thereafter), for common associated complications, and that biochemical control does not become the only treatment goal. Mortality and morbidities in acromegaly can be reduced successfully if patients are treated using a multimodal approach with comprehensive comorbidity management.