Leishmania donovani glycosphingolipid facilitates antigen presentation by inducing relocation of CD1d into lipid rafts in infected macrophages

NKT cells respond to presentation of specific glycolipids with release of both Th1‐ and Th2‐type cytokines. Leishmania donovani (LD)‐infected splenic macrophages (sM?(I)) and bone marrow‐derived dendritic cells (BMDC(I)) failed to activate NKT cells in response to α‐galactosyl ceramide (α‐GalCer). The defective antigen presentation could be corrected by treating the cells with the immunostimulating glycosphingophospholipid (GSPL) of LD parasites. In vitro pulsing of BMDC(I) or sM?(I) with GSPL, caused the activation of the Vα14⁺ CD1d1‐specific NKT cell hybridoma DN32.D3. Localization of MHC II and CD1d molecules to membrane lipid rafts has been suggested to play an important role in antigen presentation. Confocal analysis clearly demonstrated that LD infection changed the pattern of CD1d distribution to the non‐lipid raft regions and this change could be reversed by GSPL treatment. Isoelectric focusing gel shift assay indicated that GSPL binds to CD1d. GSPL‐treated but not untreated BMDC(I) formed immune synapses with NKT cells and this was associated with calcium mobilization. In conclusion, GSPL treatment was associated with modification of BMDC(I)/sM?(I) lipid raft structure, which is a site for immune regulation.     

The reconstitution of the thymus in immunosuppressed individuals restores CD4-specific cellular and humoral immune responses

Infection with HIV-1 frequently results in the loss of specific cellular immune responses and an associated lack of antibodies. Recombinant growth hormone (rGH) administration reconstitutes thymic tissue and boosts the levels of peripheral T cells, so rGH therapy may be an effective adjuvant through promoting the recovery of lost cellular and T-cell-dependent humoral immune responses in immunosuppressed individuals. To test this concept, we administered rGH to a clinically defined group of HIV-1-infected subjects with defective cellular and serological immune responses to at least one of three commonly employed vaccines (hepatitis A, hepatitis B or tetanus toxoid). Of the original 278 HIV-1-infected patients entering the trial, only 20 conformed to these immunological criteria and were randomized into three groups: Group A (n = 8) receiving rGH and challenged with the same vaccine to which they were unresponsive and Groups B (n = 5) and C (n = 7) who received either rGH or vaccination alone, respectively. Of the eight subjects in Group A, five recovered CD4 cellular responses to vaccine antigen and four of these produced the corresponding antibodies. In the controls, three of the five in group B recovered cellular responses with two producing antibodies, whereas three of the seven in Group C recovered CD4 responses, with only two producing antibodies. Significantly, whereas seven of ten patients receiving rGH treatment in Group A (six patients) and B (one patient) recovered T-cell responses to HIVp24, only two of six in Group C responded similarly. In conclusion, reconstitution of the thymus in immunosuppressed adults through rGH hormone treatment restored both specific antibody and CD4 T-cell responses.     

A new strategy for Aedes aegypti (Diptera: Culicidae) control with community participation using a new fumigant formulation

Dengue and dengue hemorrhagic fever are mosquito-borne viral diseases that coincide with the distribution of Aedes aegypti (L.), the primary vector in the tropical and semitropical world. With no available vaccine, controlling the dengue vector is essential to avoid epidemics. This study evaluates the efficacy of a new smoke-generating formulation containing pyriproxyfen and permethrin in Puerto Libertad, Misiones, Argentina. A fumigant tablet (FT) was applied inside the houses by the community members and compared with a professional application. A treatment combining the application of fumigant tablets indoors and ultralow volume fumigation outdoors was also assessed. The community perceptions and practices about dengue disease and the acceptance of this new nonprofessional FT were evaluated through surveys. Results show >90% adult emergence inhibition and 100% adult mortality with these treatments. More than 80% of the residents applied the FT and preferred participating in a vector control program by using a nonprofessional mosquito control tool, instead of attending meetings and workshops promoting cultural changes.     

Methodological quality of randomised controlled trials in burns care. A systematic review

Objective

To evaluate the methodological quality of published randomised controlled trials (RCTs) in burn care treatment and management.

Methods

Using a predetermined search strategy we searched Ovid MEDLINE (1950 to January 2008) database to identify all English RCTs related to burn care. Full text studies identified were reviewed for key demographic and methodological characteristics. Methodological trial quality was assessed using the Jadad scale.

Results

A total of 257 studies involving 14,535 patients met the inclusion criteria. The median Jadad score was 2 (out of a best possible score of 5). Information was given in the introduction and discussion sections of most RCTs, although insufficient detail was provided on randomisation, allocation concealment, and blinding. The number of RCTs increased between 1950 and 2008 (Spearman's rho = 0.6129, P < 0.001), although the reporting quality did not improve over the same time period (P = 0.1896) and was better in RCTs with larger sample sizes (median Jadad score, 4 vs. 2 points, P < 0.0001). Methodological quality did not correlate with journal impact factor (P = 0.2371).

Conclusions

The reporting standards of RCTs are highly variable and less than optimal in most cases. The advent of evidence-based medicine heralds a new approach to burns care and systematic steps are needed to improve the quality of RCTs in this field. Identifying and reviewing the existing number of RCTs not only highlights the need for burn clinicians to conduct more trials, but may also encourage burn health clinicians to consider the importance of conducting trials that follow appropriate, evidence-based standards.     

Prevalence of neuromyelitis optica spectrum disorder and phenotype distribution

Neuromyelitis optica spectrum disorder (NMOsd) is a group of demyelinating disorders recently redefined and associated with NMO-IgG/anti-aquaporin 4 antibodies. Because NMOsd is of unknown prevalence worldwide, we conducted a retrospective, cross-sectional study of 850 patients with demyelinating disorders hospitalized in North East Tuscany from 1998 to 2006 to examine the prevalence of NMO and related disorders among unselected consecutive neurological patients with inflammatory CNS diseases and to evaluate the clinical phenotype spectrum of identified cases. Clinical data were updated after at least 2 years of follow-up. An immunofluorescence technique was used to detect NMO-IgG on rat brain tissue. Sera from other 828 neurological patients, 65 non-neurological patients and 50 healthy donors served as controls. The prevalence of NMOsd was 1.5%, with a MS:NMOsd ratio of 42.7. Among 13 NMOsd patients, 77% had long spinal cord lesions, 38% had severe optic neuritis and 23% had brain or brainstem lesions. Only 56% had clinically definite NMO at follow-up. The final EDSS score ranged from 1 to 10, mainly depending on brainstem involvement occurrence. Our findings confirm a low prevalence of NMO and related disorders among demyelinating inflammatory diseases in a Caucasian population. Moreover, this study demonstrates an unexpectedly high prevalence of limited and atypical variants of this disease, not previously documented.     

Penetrance of FMR1 premutation associated pathologies in fragile X syndrome families

Within the past few years, there has been a significant change in identifying and characterizing the FMR1 premutation associated phenotypes. The premutation has been associated with elevated FMR1 mRNA levels and slight to moderate reductions in FMRP levels. Furthermore, it has been established that ∼20% of female premutation carriers present primary ovarian insufficiency (POI) and that fragile X-associated tremor/ataxia syndrome (FXTAS) occurs in one-third of all male premutation carriers older than 50 years. Besides POI and FXTAS, new disorders have recently been described among individuals (especially females) with the FMR1 premutation. Those pathologies include thyroid disease, hypertension, seizures, peripheral neuropathy, and fibromyalgia. However there are few reports related to FXTAS penetrance among female premutation carriers or regarding these disorders recently associated to the FMR1 premutation. Therefore, we have evaluated 398 fragile X syndrome (FXS) families in an attempt to provide an estimation of the premutation associated phenotypes penetrance. Our results show that signs of FXTAS are detected in 16.5% of female premutation carriers and in 45.5% of premutated males older than 50 years. Furthermore, among females with the FMR1 premutation, penetrance of POI, thyroid disease and chronic muscle pain is 18.6, 15.9 and 24.4%, respectively. The knowledge of this data might be useful for accurate genetic counselling as well as for a better characterization of the clinical phenotypes of FMR1 premutation carriers.     

Loss of Cytochrome P450 17A1 Protein Expression in a 17α-Hydroxylase/17,20-Lyase-Deficient 46,XY Female Caused by Two Novel Mutations in the CYP17A1 Gene

17α-Hydroxylase deficiency (17OHD) is a rare form of congenital adrenal hyperplasia caused by mutations in the CYP17A1 gene. This condition shows considerable clinical and biochemical variation. Molecular characterization of novel mutations in the CYP17A1 gene and detailed study of their structural, enzymatic, and clinical consequences are required to fully understand enzyme behavior. Here, we present the first molecular characterization of two novel mutations in CYP17A1 in a 15-year-old female Mexican mestizo 46,XY female with primary amenorrhea and lack of pubertal development and severe hypertension that manifested only after surgery. A complete clinical and biochemical evaluation was compatible with 17OHD. Structural anomalies in the CYP17A1 gene were discovered by direct automated sequencing, which revealed a novel compound heterozygous K110X/R362H mutation that leads to a complete lack of enzyme activity. Immunohistochemical analyses performed to determine protein expression and localization showed that cytochrome P450 17A1 was completely absent in the patient’s testicular tissue. Studies of novel mutations, such as those described here, provide important information that allows us to better understand the effect of a given mutation on enzyme function and to observe the impact of the mutation on clinical phenotype.     

Inducible and endothelial nitric oxide synthase expression in human atherogenesis: an immunohistochemical and ultrastructural study

BackgroundNitric oxide has been proven to play an important role in the maintenance of vascular tone and structure. Impairment of nitric oxide production is an early indicator of atherosclerosis, but not much is known about the real mechanisms underlying this phenomenon.MethodsIn the present study, immunocytochemical methods have been used to analyze the patterns of expression of endothelial nitric oxide synthase and inducible nitric oxide synthase proteins in healthy and atherosclerotic human aortae using both confocal laser scanning microscopy and electron microscopy.ResultsInduction of the expression of endothelial nitric oxide synthase and inducible nitric oxide synthase proteins was observed in smooth muscle cells of atherosclerotic human aortae. Altered nitric oxide synthase expression was reported in atheromatous plaques and in apparently normal vascular tissues adjacent to the lesions.ConclusionsOur data confirm and extend previous findings of a direct relationship between dysregulation of nitric oxide pathway and atherosclerosis, suggesting another possible mechanism by which nitric oxide synthase system abnormalities may promote vascular dysfunction during human atherogenesis. Changes in nitric oxide production might be the primary step in the development of atheroma.