Diabetic retinopathy at the Yaoundé Central Hospital in Cameroon: epidemiology and angiographic findings

We carried out a cross-sectional analytical survey using data from patients who had done Fluorescein Angiography at the Yaounde Central Hospital Diabetic Retinopathy Prevention and Management Project between October 2007 and January 2010 to identify the risk factors, incidence and severity of different types of diabetic retinopathy. Data from 239 males (57.0%) and 180 females (43.0%) with diabetic retinopathy were included. Their mean age was 58.2 years. A majority of them were living with type II diabetes (96.2%). The mean duration of diabetes was 8.2 years. About sixty percent had both diabetes and hypertension. The average level of glycated haemoglobin was 9.72% (range 6-17.7%). Amongst the 419 patients with diabetic retinopathy, 292(69.7%) had non-proliferative diabetic retinopathy. One hundred and twelve (26.7%) of those with proliferative diabetic retinopathy had a formal indication for laser photocoagulation. Fifteen patients (3.6%) presented with complicated forms of proliferative diabetic retinopathy. Diabetic maculopathy was present in 30 patients (7.2%). Diabetic retinopathy is a frequent complication of diabetes in our setting which stems from inadequate emphasis on preventive measures. The technical requirements for managing some of the existing complications are still unavailable. Fluorescein Angiography is an important diagnostic tool which should be popularized.Pan African Medical Journal 2012; 13:5

Measles Virus Infects Human Dendritic Cells and Blocks Their Allostimulatory Properties for CD4+ T Cells

Measles causes a profound immune suppression which is responsible for the high morbidity and mortality induced by secondary infections. Dendritic cells (DC) are professional antigen-presenting cells required for initiation of primary immune responses. To determine whether infection of DC by measles virus (MV) may play a role in virus-induced suppression of cell-mediated immunity, we examined the ability of CD1a+ DC derived from cord blood CD34+ progenitors and Langerhans cells isolated from human epidermis to support MV replication. Here we show that both cultured CD1a+ DC and epidermal Langerhans cells can be infected in vitro by both vaccine and wild type strains of MV. DC infection with MV resulted within 24–48 h in cell–cell fusion, cell surface expression of hemagglutinin, and virus budding associated with production of infectious virus. MV infection of DC completely abrogated the ability of the cells to stimulate the proliferation of naive allogeneic CD4+ T cell as early as day 2 of mixed leukocyte reaction (MLR) (i.e., on day 4 of DC infection). Mannose receptor–mediated endocytosis and viability studies indicated that the loss of DC stimulatory function could not be attributed to the death or apoptosis of DC. This total loss of DC stimulatory function required viral replication in the DC since ultraviolet (UV)-inactivated MV or UV-treated supernatant from MV-infected DC did not alter the allostimulatory capacity of DC. As few as 10 MV- infected DC could block the stimulatory function of 104 uninfected DC. More importantly, MV-infected DC, in which production of infectious virus was blocked by UV treatment or paraformaldehyde fixation, actively suppressed allogeneic MLR upon transfer to uninfected DC–T-cultures. Thus, the mechanisms which contribute to the loss of the allostimulatory function of DC include both virus release and active suppression mediated by MV-infected DC, independent of virus production. These data suggest that carriage of MV by DC may facilitate virus spreading to secondary lymphoid organs and that MV replication in DC may play a central role in the general immune suppression observed during measles

GWAS meta-analysis of intrahepatic cholestasis of pregnancy implicates multiple hepatic genes and regulatory elements

Intrahepatic cholestasis of pregnancy (ICP) is a pregnancy-specific liver disorder affecting 0.5–2% of pregnancies. The majority of cases present in the third trimester with pruritus, elevated serum bile acids and abnormal serum liver tests. ICP is associated with an increased risk of adverse outcomes, including spontaneous preterm birth and stillbirth. Whilst rare mutations affecting hepatobiliary transporters contribute to the aetiology of ICP, the role of common genetic variation in ICP has not been systematically characterised to date. Here, we perform genome-wide association studies (GWAS) and meta-analyses for ICP across three studies including 1138 cases and 153,642 controls. Eleven loci achieve genome-wide significance and have been further investigated and fine-mapped using functional genomics approaches. Our results pinpoint common sequence variation in liver-enriched genes and liver-specific cis-regulatory elements as contributing mechanisms to ICP susceptibility

West Nile Virus: High Transmission Rate in North-Western European Mosquitoes Indicates Its Epidemic Potential and Warrants Increased Surveillance

International audienceBackgroundWest Nile virus (WNV) is a highly pathogenic flavivirus transmitted by Culex spp. mosqui- toes. In North America (NA), lineage 1 WNV caused the largest outbreak of neuroinvasive disease to date, while a novel pathogenic lineage 2 strain circulates in southern Europe. To estimate WNV lineage 2 epidemic potential it is paramount to know if mosquitoes from cur- rently WNV-free areas can support further spread of this epidemic.Methodology/Principal FindingsWe assessed WNV vector competence of Culex pipiens mosquitoes originating from north-western Europe (NWE) in direct comparison with those from NA. We exposed mos- quitoes to infectious blood meals of lineage 1 or 2 WNV and determined the infection and transmission rates. We explored reasons for vector competence differences by comparing intrathoracic injection versus blood meal infection, and we investigated the influence of temperature. We found that NWE mosquitoes are highly competent for both WNV lineages, with transmission rates up to 25%. Compared to NA mosquitoes, transmission rates for line- age 2 WNV were significantly elevated in NWE mosquitoes due to better virus dissemina- tion from the midgut and a shorter extrinsic incubation time. WNV infection rates further increased with temperature increase.Conclusions/SignificanceOur study provides experimental evidence to indicate markedly different risk levels between both continents for lineage 2 WNV transmission and suggests a degree of genotype-geno- type specificity in the interaction between virus and vector. Our experiments with varying temperatures explain the current localized WNV activity in southern Europe, yet imply fur- ther epidemic spread throughout NWE during periods with favourable climatic conditions. This emphasizes the need for intensified surveillance of virus activity in current WNV dis- ease-free regions and warrants increased awareness in clinics throughout Europe

Variants of WDR36 in Cameroonian glaucoma patients

Background: In Primary Open Angle Glaucoma (POAG), the most common form of glaucoma in people of African origin, it is established that retinal ganglion cells are lost due to apoptosis. Loss of WDR36 (OMIM 609669) function has been shown to result in activation of the p53 stress-response pathway, a key regulator of apoptosis. However, there is controversy surrounding its contribution in the pathogenesis of POAG. We aimed to establish an association between 3 WDR36 gene polymorphisms and POAG.Methods: We assessed 798 glaucoma medical records and selected 209 POAG cases. A total of 26 POAG cases residing in Yaoundé completed the study and 19 controls were matched for age and gender. Dried blood spots on Whatman filter paper grade 3 were used for DNA extraction by the Chelex method. Polymerase Chain Reaction (PCR) was conducted with two sets of primers on rs1971050, rs10038177 and rs10038058 followed by Restriction Fragment Length Polymorphism (RFLP) using restriction enzymes AluI on rs1971050, rs10038177and ApoI on rs10038058 to determine the genotypes.&nbsp;Results: After digestion, the homozygous mutant form of rs1971050 was evidenced in both groups of our study population T/T (100%). The T and the A alleles were the most common alleles found in our study population and were not associated with POAG. Heterozygote and homozygote mutant genotypes were obtained in both groups for rs10038177 (POAG group C/T (7.7%) and T/T (92.3%) and in the control group C/T (10.5%) and T/T (89.5%)) and rs10038058 (G/A (11.5%) and A/A (88.5%) genotypes in the POAG group and in the control group G/A (10.5%) and A/A (89.5%)). These genotypes were not associated with Primary Open Angle Glaucoma (POAG).&nbsp;Conclusion: Homozygous mutant genotypes of rs1971050, rs10038177 and rs10038058 may not be associated with the disease process of primary open angle glaucoma in Cameroon.&nbsp;</p