Clinical and microbiological assessment of trachoma in the kolofata health district, far north region, cameroon

Background and aims: Trachoma is a sight-threatening process triggered by the infection of the conjunctiva with Chlamydiae. Blindness associated with trachoma was reported in Sahelian areas of Cameroon. However, data on the prevalence of this neglected infection in the Far North Region are not available. The aim of this study was a) to assess clinical trachoma and b) to detect Chlamydia in the conjunctiva of trachomatous populations living in the Far North Regions of Cameroon.Methods: A total of 2,423 randomly selected children (1–10 years) and 1,590 women over 14 from randomly selected villages from the Kolofata Health District (115,000 inhabitants) were included in a cross-sectional study in February 2009. Trained staff examined and obtained conjunctival swabs from trachomatous subjects. DNA was extracted and amplified to detect Chlamydia DNA by real-time PCR. The quality of sampling was assessed by quantifying the number of epithelial cells.Results: Children (2,397 or 98.9% of the predicted number) and women (1,543; 97.0%) were examined. The prevalence of follicular trachoma (TF) in children was 21% (95% CI 17.8–24.5) and of intense inflammatory trachoma (TI) 5.2% (95% CI 3.6–7.3). Among the women, trichiasis (TT) was observed in 3.4% (95% CI 2.4–4.7), corneal opacities (CO) in 1.4% (95% CI 0.8–2.3) and trachoma-related blindness in 0.9% (95% CI 0.4–1.8). Conditions related to income, illiteracy, latrines, water supply and animals wandering close to dwellings were similar in all the villages. PCR was positive in 35% of children with active trachoma and in 6% of adult females presenting TT and/or related corneal opacities.Conclusion: The prevalence of trachoma and the severe trachoma sequelae found during this survey underline the urgent need to implement efficient blindness prevention interventions to improve the visual future of the people in the Sahelian region.     

Blood flow to the heart from noncoronary arteries: an intriguing but challenging research field

IntroductionIt has been proven that blood supply to the heart can include blood from noncoronary collateral circulation. Whether this network can somehow be augmented to provide an alternative therapy for ischemic patients is an intriguing hypothesis with no clear answer yet due to the challenging nature of this research field. In an attempt to enhance noncoronary collateral blood flow, we experimented with left internal thoracic artery ligature and angiogenic growth factors in a canine model.Materials and methodsEight dogs weighing between 20 and 29 kg were scheduled for three operations each. Neutron-activated microspheres were used for blood flow measurement throughout the study. The first operation was a left thoracotomy for ameroid constrictor positioning at the proximal segment of the circumflex coronary artery. Three weeks later the left internal thoracic artery was ligatured distally. A micro-pump was positioned in the mediastinum, connected with a small catheter inserted in the proximal segment of the left internal thoracic artery for slow delivery of vascular endothelial growth factor. The protocol called for a coronary angiography 4 weeks later, sacrifice of the animals, and explantation of the heart for microsphere analysis.ResultsFour of the dogs failed to tolerate ameroid constrictor positioning by thoracotomy and died after the first operation. The remaining four dogs underwent a second operation to ligate their left internal thoracic arteries and implant micro-pumps with catheters. The implant was a success, but only one dog survived in the postoperative period. When the last dog was voluntarily sacrificed after a third operation, coronary angiography showed no neovascularization, nor did heart slice analysis reveal microspheres.ConclusionsDespite the technical challenge of building research protocols to exactly quantify blood from noncoronary arteries, there are many historical, anatomical, physiopathological, clinical, radiological, and surgical indications suggesting that blood flow from extracardiac structures may play an important role in ischemic heart disease. Our preliminary investigation combining internal thoracic artery occlusion and angiogenic growth factors was unsuccessful for several reasons, the main one being it was too heavy a protocol for the dogs. Despite this, we think that noncoronary collateral blood flow represents an intriguing research field worthy of debate and further study.     

Urinary low-molecular-weight protein excretion in pediatric idiopathic nephrotic syndrome

Background

Minimal change disease (MCD) and focal segmental glomerulosclerosis (FSGS) are the most common causes of idiopathic nephrotic syndrome (INS). We have evaluated the reliability of urinary neutrophil-gelatinase-associated lipocalin (uNGAL), urinary alpha1-microglobulin (uα1M) and urinary N-acetyl-beta-D-glucosaminidase (uβNAG) as markers for differentiating MCD from FSGS. We have also evaluated whether these proteins are associated to INS relapses or to glomerular filtration rate (GFR).

Methods

The patient cohort comprised 35 children with MCD and nine with FSGS; 19 healthy age-matched children were included in the study as controls. Of the 35 patients, 28 were in remission (21 MCD, 7 FSGS) and 16 were in relapse (14 MCD, 2 FSGS). The prognostic accuracies of these proteins were assessed by receiver operating characteristic (ROC) curve analyses.

Results

The level of uNGAL, indexed or not to urinary creatinine (uCreat), was significantly different between children with INS and healthy children (p?=?0.02), between healthy children and those with FSGS (p?=?0.007) and between children with MCD and those with FSGS (p?=?0.01). It was not significantly correlated to proteinuria or GFR levels. The ROC curve analysis showed that a cut-off value of 17 ng/mg for the uNGAL/uCreat ratio could be used to distinguish MCD from FSGS with a sensitivity of 0.77 and specificity of 0.78. uβNAG was not significantly different in patients with MCD and those with FSGS (p?=?0.86). Only uα1M, indexed or not to uCreat, was significantly (p?<?0.001) higher for patients in relapse compared to those in remission.

Conclusions

Our results indicate that in our patient cohort uNGAL was a reliable biomarker for differentiating MCD from FSGS independently of proteinuria or GFR levels.     

Examining Self-Training Procedures in Leisure Swimming

This study investigated contents of training sessions from 387 regular swimmers involved in a recreational workout without supervision. We did use multiple correspondences analysis in order to identify self-trained swimmers typology in a sample from a social networking website, focusing on swimming practice. Self-reported parameters (n = 12) were age, gender, practice frequency, supervision in physical activity experiment, main training target, main reason for swimming choice, swimming session duration and distance, most used swimming stroke and material, quality of the training control, and training evolution during a year. Results have highlighted different training strategies and targets according to gender and age. Male strategy consists in performing higher distance (1818.8 ± 644.5 m vs. 1453.0 ± 603.3, p < 0.05 for male and female respectively) by using several swim stroke and gears involving upper body muscles (front crawl, pull buoy and paddles). More concerned about duration of their sessions, women are mainly using breaststroke. Backstroke is associated with people aged higher than 50. We also have established a connection between motives according to ages and long term strategies. The main motivation for middle aged people appears to be general health benefits by performing identical swimming session without evolution during a year. People aged from 20 to 30 are divided between an identical swimming session strategy and an increase in distance or in intensity strategy during a year. This population appears to be concerned about a global health benefits and a body shape effects. Suggestions are made to improve swimming practice environment during free time sessions according to the main results.

Key Points

• Male strategy consists in performing higher distance by using several swim stroke and gears involving upper body muscles whereas women are more concerned about effort duration and use breaststroke in majority.
• The main motivation for middle aged people appears to be general health benefits whereas people aged from 20 to 30 appears to be concerned about a global health benefits and a body shape effects.
• Excepted middle age people, recreational swimmers have low control quality of their session even if they have a good skill level. This suggests to improve health strategy education and swimming pool environment.

Key words: Physical activity, strategy, multiple correspondence analysis, leisure swimming     

Reduced plasma membrane surface expression of GLAST mediates decreased glutamate regulation in the aged striatum

Extracellular L-glutamate poses a severe excitotoxic threat to neurons and glia when unregulated, therefore low synaptic levels of this neurotransmitter must be maintained via a rapid and robust transport system. A recent study from our laboratory showed a reduced glutamate uptake rate in the striatum of the aged Fischer 344 (F344) rat, yet the mechanism underlying this phenomenon is unknown. The current study utilized in vivo electrochemical recordings, immunoblotting and biotinylation in young (6 months), late-middle aged (18 months) and aged (24 months) F344 rats to elucidate the potential role that glutamate transporters (GLT-1, GLAST, and EAAC1) may play in this mechanism. Here we show that the time necessary to clear glutamate from the late-middle aged and aged striatum is significantly prolonged in comparison to the young striatum. In addition, an analysis of various sub-regions of the striatum revealed a marked dorsoventral gradient in terms of glutamate clearance times in the aged striatum, a phenomenon which was not present in the striatum of the animals of the remaining age groups. We also found that the decreased glutamate clearance time observed in the late-middle aged and aged rats is not due to a decrease in the production of total transporter protein among these three transporters. Rather, a significant reduction in the amount of GLAST expressed on the plasma membrane surface in the aged animals (approximately 55% when compared to young rats) may contribute to this phenomenon. These age-related alterations in extracellular l-glutamate regulation may be key contributors to the increased susceptibility of the aged brain to excitotoxic insults such as stroke and hypoxia.     

Synchrotron-based intravenous cerebral angiography in a small animal model

K-edge digital subtraction angiography (KEDSA), a recently developed synchrotron-based technique, utilizes monochromatic radiation and allows acquisition of high-quality angiography images after intravenous administration of contrast agent. We tested KEDSA for its suitability for intravenous cerebral angiography in an animal model. Adult male New Zealand rabbits were subjected to either angiography with conventional x-ray equipment or synchrotron-based intravenous KEDSA, using an iodine-based contrast agent. Angiography with conventional x-ray equipment after intra-arterial administration of contrast agent demonstrated the major intracranial vessels but no smaller branches. KEDSA was able to visualize the major intracranial vessels as well as smaller branches in both radiography mode (planar images) and tomography mode. Visualization was achieved with as little as 0.5 ml kg-1 of iodinated contrast material. We were able to obtain excellent visualization of the cerebral vasculature in an animal model using intravenous injection of contrast material, using synchrotron-based KEDSA.     

Integrating functional and anatomical information to facilitate cardiac resynchronization therapy

Multiple imaging modalities are required in patients receiving cardiac resynchronization therapy. We have developed a strategy to integrate echocardiographic and angiographic information to facilitate left ventricle (LV) lead position. Full three-dimensional LV-volumes (3DLVV) and dyssynchrony maps were acquired before and after resynchronization. At the time of device implantation, 3D-rotational coronary venous angiography was performed. 3D-models of the veins were then integrated with the pre- and post-3DLVV. In the case displayed, prior to implantation, the lateral wall was delayed compared to the septum. The LV lead was positioned into the vein over the most delayed region, resulting in improved LV synchrony.     

FDC:TFH Interactions within Cervical Lymph Nodes of SIV-Infected Rhesus Macaques

Cerebrospinal fluid (CSF) drains via the lymphatic drainage pathway. This lymphatic pathway connects the central nervous system (CNS) to the cervical lymph node (CLN). As the CSF drains to CLN via the dural and nasal lymphatics, T cells and antigen presenting cells pass along the channels from the subarachnoid space through the cribriform plate. Human immunodeficiency virus (HIV) may also egress from the CNS along this pathway. As a result, HIV egressing from the CNS may accumulate within the CLN. Towards this objective, we analyzed CLNs isolated from rhesus macaques that were chronically-infected with simian immunodeficiency virus (SIV). We detected significant accumulation of SIV within the CLNs. SIV virion trapping was observed on follicular dendritic cells (FDCs) localized within the follicular regions of CLNs. In addition, SIV antigens formed immune complexes when FDCs interacted with B cells within the germinal centers. Subsequent interaction of these B cells with CD4+ T follicular helper cells (T_FHs) resulted in infection of the latter. Of note, 73% to 90% of the T_FHs cells within CLNs were positive for SIV p27 antigen. As such, it appears that not only do the FDCs retain SIV they also transmit them (via B cells) to T_FHs within these CLNs. This interaction results in infection of T_FHs in the CLNs. Based on these observations, we infer that FDCs within the CLNs have a novel role in SIV entrapment with implications for viral trafficking.