The spatial relationship between type I glomus cells and arteriolar myocytes in the mouse carotid body

The structural relationship between type I glomus cells and the vascular smooth muscle was investigated by electron microscopy in the mouse carotid body. A close apposition (<0.1 μm) between the glomus parenchyma and the neighbouring arterioles was regularly present. Profiles of type I glomus cells were found to be exposed to the vascular smooth muscle without any supporting cell investment. In circumscribed areas of these profiles, type I glomus cells and the vascular smooth muscle cells made contact by fusion of their basal laminae. These glomus-cell-myocyte junctions structurally resemble vascular neuromuscular junctions of sympathetic nerve terminals. In addition to the occurrence of such glomus cell-myocyte contacts, myoendothelial junctions also appeared frequently. On the basis of these observations, it is suggested that type I glomus cells play a role in the regulation of the vascular tone in the carotid body and that a physiological interaction between the endothelial cells, the vascular smooth muscle cells and the type I glomus cells exists.     

Blood Oxidant/Antioxidant Status in overfed Aging Rats: Comparative Effects of Sunflower and Olive-Linseed Mixture Oil Rich Diets

Obesity,one of the most common health problems,is associated with glucose and lipid metabolism abnormalities,increased cardiovascular risk and oxidative stress[1].Aging is also associated with an increase in oxidative stress[2].Considering that older adults are already at risk for oxidant stress,the additional metabolic perturbations of obesity aggravated the susceptibility to oxidant stress.Modulating age-related oxidative stress via dietary interventions could reduce free radical production and significantlyimprove health in aging.     

Burden of anemia among indigenous populations

An international perspective of the magnitude of anemia in indigenous peoples is currently lacking. The present systematic review was performed to characterize the global prevalence, severity, and etiology of anemia in indigenous peoples by conducting a systematic search of original research published in English from 1996 to February 2010 using PubMed, Medline, and Embase. A total of 50 studies, representing the following 13 countries, met the inclusion criteria: Australia, Brazil, Canada, Guatemala, India, Kenya, Malaysia, Mexico, New Zealand, Sri Lanka, Tanzania, the United States, and Venezuela. Results indicate major deficiencies in the coverage and quality of anemia monitoring data for indigenous populations worldwide. The burden of anemia is overwhelmingly higher among indigenous groups compared to the general population and represents a moderate (20-39.9%) to severe (≥40%) public health problem. For the most part, the etiology of anemia is preventable and includes inadequate diet, poor living conditions, and high infection rates (i.e., malaria and intestinal parasites). A concerted global effort is needed to reduce the worldwide burden of anemia in these marginalized populations.     

A US-based survey on ventriculostomy practices

Background

The incidence of ICP monitoring has increased over the years and the indications for placement have expanded. Although ventriculostomy and ICP monitor placement are among the most commonly performed neurosurgical procedures, the current practice patterns have rarely been studied.

Methods

A 10-question survey was sent to 2006 neurosurgeons and 1060 neurosurgery residents in the US. Demographic information and data regarding estimated success rates of ventriculostomies, the steps taken in failure and use of technological aids used was sought.

Results

479 neurosurgeons and 108 residents responded to our survey (response rates 23.9% and 10.2%, respectively). No catheter misplacements were reported by 19.8% respondents in the previous year whereas 2.2% reported misplacing more than 30%. With regards to ventriculostomy for patients with slit ventricles, image guidance was used by 51.7%; freehand technique was preferred by 41.6% and the Ghajar guide was used by 6.7% of respondents. We found that 56.9% of respondents abandoned free-hand placement after 3 failed passes. After abandoning free-hand cannulation, respondents used an ICP bolt or similar intra-parenchymal pressure monitoring device in trauma patients. Other approaches included leaving the catheter in place and readjusting it after repeating a CT scan.

Conclusions

This survey sheds light on the current practice of ventriculostomy placement. Both residents and neurosurgeons admit to multiple attempts and frequent catheter misplacement. In order to consider a change in practice, respondents cited an increase in available data about guidance systems and ability to accommodate abnormal ventricular anatomy as primary requirements. A prospective study could help establish true evidence based practice for this common neurosurgical procedure.     

Hyperbaric oxygen therapy in the treatment of radiation optic neuropathy

Radiation optic neuropathy (RON) is characterized by the rapid onset of painless irreversible vision loss in one or both eyes. We report 4 consecutive patients who presented with unilateral or asymmetric bilateral RON. All had bilateral optic nerve enhancement on MRI and were treated with hyperbaric oxygen (HBO) and oral corticosteroids. In the less affected eye, 2 of the 4 patients had preservation of vision, while in the other 2 patients, vision declined. No patient showed improvement in the more symptomatic eye, and in 2 patients, there was a significant decline in visual acuity. Our findings suggest that prompt treatment with HBO and oral corticosteroids may result in visual preservation in the less affected eye despite the presence of optic nerve enhancement on MRI.     

Clinical and single-photon emission computed tomography study of pure akinesia with freezing of gait

The clinical syndrome of pure akinesia (PA) is considered the third phenotype of progressive supranuclear palsy (PSP), and is characterized by freezing of gait and prominent speech disturbance without rigidity or tremor. It is frequently considered one of the dopamine resistant motor syndromes, and its pathophysiology remains unclear. We report a patient followed in the Department of Neurology of Razi Hospital, Tunisia, with PA with gait freezing (PAGF) with a frontal hypoperfusion on single photon emission CT and non-responsive dopa therapy. We discuss the clinical features of PAGF and efficiency of treatment options.     

Theoretical model of critical issues in informed consent in HIV vaccine trials

The informed consent process (ICP) for HIV vaccine trials poses unique challenges and would benefit from improvements to its historically based structure and format. Here, we propose a theoretical framework that provides a basis for systematically evaluating and addressing these challenges. The proposed framework follows a linear pathway, starting with the precondition of voluntariness, three main variables of valid decision-making (competency, provision of information and understanding) and then the consequential outcome of either refusal or consent to participate. The existing literature reveals that culturally appropriate provision of information and resultant understanding by the vaccine trial participant are among the most significant factors influencing the authenticity of valid decision-making, though they may be overridden by other considerations, such as individual altruism, mistrust, and HIV-related stigma. Community collaborations to foster bidirectional transmission of information and more culturally tailored consenting materials, therefore, represent a key opportunity to enhance the ICP. By providing a visual synopsis of the issues most critical to IC effectiveness in a categorical and relational manner, the framework provided here presents HIV vaccine researchers a tool by which the ICP can be more systematically evaluated and consequently improved.