Streamlined flow in the portal vein: demonstration with MR angiography

PURPOSE: To demonstrate whether streamlining of the portal vein flow exists by evaluating the relative distribution of blood flowing from the superior mesenteric vein (SMV) and splenic vein (SV) into the portal venous system. MATERIALS AND METHODS: Fifteen healthy adult volunteers underwent MR angiography of the main portal vein (PV) and portal vein branches after an overnight fast. Transverse two dimension time-of-flight gradient echo sequences were obtained three times, in suspended expiration and inspiration, respectively, as follows: 1) No presaturation slab, 2) presaturation slab across the SMV, 3) presaturation slab across the SV. Signal intensity (SI) measurements were obtained for all acquisitions. using regions of interest traced manually within the PV and portal branches. RESULTS: After presaturation of the SMV and SV during expiration, the overall SI average in the PV decreased by 47% +/- 8 (mean +/- SD) and 17% +/- 9, respectively. Right to left portal branch SI ratio and right-anterior to left-posterior SI ratio in the PV were 0.91 +/- 0.09 and 1.02 +/- 0.08 at baseline, respectively. They decreased significantly (P < 0.05) to 0.87 +/- 0.09 and to 0.95 +/- 0.09 after saturation of the SMV, and increased significantly to 0.95 +/- 0.08 and to 1.07 +/- 0.10 after saturation of the SV. CONCLUSION: MR angiography with selective saturation of the SMV and SV provided reproducible assessment of the respective contributions of the SMV and SV to portal flow, and allows demonstration that streamlining of splanchnic blood occurs in the portal vein of normal subjects.     

Effect of GDNF-releasing biodegradable microspheres on the function and the survival of intrastriatal fetal ventral mesencephalic cell grafts.

The transplantation of fetal ventral mesencephalic (FVM) cell suspensions into the brain striatal system is an alternative approach for the treatment of Parkinson's disease (PD). However, one objection to this procedure is the relatively poor survival of implanted cells. Attempts have been made to improve the survival of grafted dopaminergic neurons using glial cell line-derived neurotrophic factor (GDNF). Nevertheless, the clinical application of GDNF is limited, due to the difficulties in administering a protein to the brain tissue and due to the ubiquity of its receptor, thus leading to neurological side effects. A strategy to deliver GDNF in the brain based on the intracerebral implantation of biodegradable poly(D,L-lactic acid-co-glycolic acid) sustained release microspheres has been developed. Such microparticles can be easily implanted by sterotaxy in precise and functional areas of the brain without causing damage to the surrounding tissue. Moreover, the release profile of the GDNF-loaded microspheres showed a sustained release over 56 days of biologically active GDNF at clinically relevant doses. The present study shows that the implantation of GDNF-loaded microspheres at a distance to the site of FVM cells in the 6-hydroxydopamine-lesioned rat model of PD improves dopaminergic graft survival and function. Furthermore, the unloaded and the GDNF-loaded microspheres, when they are mixed with FVM cells, may provide a mechanical support and a 3D environment inducing differentiation and increased function of dopaminergic neurons. Taken together, these results show that GDNF microspheres represent an efficient delivery system for cell transplantation studies.     

The role of sexually transmitted infections in male circumcision effectiveness against HIV – insights from clinical trial simulation

Background  

A landmark randomised trial of male circumcision (MC) in Orange Farm, South Africa recently showed a large and significant reduction in risk of HIV infection, reporting MC effectiveness of 61% (95% CI: 34%–77%). Additionally, two further randomised trials of MC in Kisumu, Kenya and Rakai, Uganda were recently stopped early to report 53% and 48% effectiveness, respectively. Since MC may protect against both HIV and certain sexually transmitted infections (STI), which are themselves cofactors of HIV infection, an important question is the extent to which this estimated effectiveness against HIV is mediated by the protective effect of circumcision against STI. The answer lies in the trial data if the appropriate statistical analyses can be identified to estimate the separate efficacies against HIV and STI, which combine to determine overall effectiveness.     

Illness-related behaviour and utilization of oral health services among adult city-dwellers in Burkina Faso: evidence from a household survey

Background  

In sub-Saharan Africa, the availability and accessibility of oral health services are seriously constrained and the provision of essential oral care is limited. Reports from the region show a very low utilization of oral health care services, and visits to dental-care facilities are mostly undertaken for symptomatic reasons. The objectives of the present study were to describe the prevalence of oral symptoms among adults in Ouagadougou, capital city of Burkina Faso and the use of oral health services and self-medication in response to these symptoms and to measure the associations between predisposing, enabling and needs factors and decisions to seek oral health care.     

Regulation of telomeres length: making the telomeres accessible?

Under a normal state, the extremities of chromosomes, telomeres, are protected against undesired fusion events. Alterations of the telomere structure are associated with genetic instability, while erosion of the telomeric repeats, occurring at each cell division, provides a mechanism controlling the long-term proliferation of somatic cells. Although the structure and composition of the human telomerase enzyme are now well characterized, the protein partners regulating the stability and conformation of its DNA substrate, the telomeric end, are much less known. A functional link has been recently evidenced between proteins that bind the double-stranded telomere repeats and those recruited at the 3' G-rich telomeric overhang. This review presents an update on these telomeric factors controlling telomere lengthening and discuss the actual models proposed for its regulation.     

A nutritional intervention promoting the Mediterranean food pattern is associated with a decrease in circulating oxidized LDL particles in healthy women from the Québec City metropolitan area

The aim of the present study was to evaluate the effect of a nutritional intervention promoting the Mediterranean food pattern under free-living conditions on circulating oxidized LDL (ox-LDL) in a group of 71 healthy women from the Quebec City metropolitan area. The 12-wk nutritional intervention consisted of 2 courses on nutrition and 7 individual sessions with a dietitian. A score based on the 11 components of the Mediterranean pyramid was established to determine the women's adherence to the Mediterranean food pattern. Plasma ox-LDL concentrations were measured by a monoclonal antibody mAb-4E6-based competition ELISA. Among all women, plasma ox-LDL decreased by 11.3% after 12 wk of nutritional intervention (P < 0.0001) despite a lack of change in plasma LDL cholesterol (LDL-C). Also, an increase in the Mediterranean dietary score was significantly correlated with a decrease in ox-LDL concentrations (r = -0.30; P = 0.01). More specifically, increases in servings of fruits (r = -0.25; P < 0.05) and vegetables (r = -0.24; P < 0.05) were associated with decreases in ox-LDL concentrations. Changes in the food pattern in response to a nutritional intervention promoting the Mediterranean food pattern were accompanied by beneficial effects in circulating ox-LDL concentrations in healthy women.     

Prevalence of lymph nodes in the apex of level V: a plea against the necessity to dissect the apex of level V in mucosal head and neck cancer

BACKGROUND: We assessed the prevalence of histologically proven normal or invaded lymph nodes in the apex of level V. METHODS: Seventy neck dissections were performed in 41 patients with mucosal head and neck squamous cell carcinoma (SCC). Fifty-one neck dissections were performed in 30 previously untreated patients (group 1); 19 neck dissections were carried out in 11 patients previously irradiated (group 2). RESULTS: Pathologic analysis was unable to identify any lymph node in 70% of the apex specimens. In group 1, no lymph nodes were detected in 63%, whereas one or more noninvaded lymph nodes were present in 37%; in group 2, no lymph nodes were identified in 89%, whereas one or more normal lymph nodes were found in 11% (p = .03). Metastatic lymph nodes were never identified. CONCLUSIONS: The prevalence of lymph nodes in the apex was 30%. No invaded lymph nodes were identified. In addition to anatomic evidence, these results suggest that dissection of the apex is not necessary in mucosal head and neck SCC.