The global burden of pulmonary hypertension in sickle cell disease: a systematic review and meta-analysis.

Elevated tricuspid regurgitant jet velocity (TRJV) is a surrogate measure of pulmonary hypertension (PH) in persons with sickle cell disease (SCD). We sought to estimate the burden of PH in people living with sickle cell disease based on TRJV. From 2000 to 2015, we searched electronic databases for eligible publications and included 29 studies (n = 5358 persons). We used random effects modeling to determine the pooled estimate of elevated TRJV. The overall pooled prevalence of elevated TRJV was 23.5 %(95 % CI 19.5-27.4) in persons with SCD. The pooled prevalence of elevated TRJV in children and adults with SCD was 20.7 % (95 % CI 15.7--25.6) and 24.4 % (95 % CI 18.4-30.4), respectively. TRJV is prevalent among adults and children with SCD. Our finding support international recommendations that call for screening for PH in SCD patients.

Prevalence of hepatitis B virus infection in Nigeria, 2000-2013: a systematic review and meta-analysis.

Vaccination against the hepatitis B virus (HBV) in the West African nation of Nigeria is lower than many Sub-Saharan African countries. In Nigeria, HBV is reported to be the most common cause of liver disease. However, the extent of HBV exposure among Nigerians at average risk is unknown. Our aim, therefore, was to accurately estimate the HBV prevalence for the country and the prevalence for specific subgroups. We used electronic databases to select systematic reviews and meta-analyses from 2000 to 2013. Forty-six studies were included (n = 34,376 persons). We used a random effects meta-analysis of cross-sectional and longitudinal studies to generate our estimates. The pooled prevalence of HBV in Nigeria was 13.6% (95% confidence interval [CI]: 11.5, 15.7%). The pooled prevalence (% [95% CI]) among subgroups was: 14.0% (11.7, 16.3) for blood donors; 14.1% (9.6, 18.6) for pregnant women attending antenatal clinics; 11.5% (6.0, 17.0) for children; 14.0% (11.6, 16.5) among adults; and 16.0% (11.1, 20.9) for studies evaluating adults and children. HBV prevalence in Nigeria varied by screening method [% (95% CI)]: 12.3% (10.1, 14.4) by using enzyme-linked immunosorbent assay; 17.5% (12.4, 22.7) by immunochromatography; and 13.6% (11.5, 15.7) by HBV DNA polymerase chain reaction. HBV infection is hyperendemic in Nigeria and may be the highest in Sub-Sahara Africa. Our results suggest that large numbers of pregnant women and children were exposed to HBV from 2000 to 2013. Increased efforts to prevent new HBV infections are urgently needed in Nigeria.

Prevalence of Hepatitis B Virus Infection in Nigeria; 2000-2013: A Systematic Review and Meta-Analysis

Vaccination against the hepatitis B virus (HBV) in the West African nation of Nigeria is lower than many Sub-Saharan African countries. In Nigeria; HBV is reported to be the most common cause of liver disease. However; the extent of HBV exposure among Nigerians at average risk is unknown. Our aim; therefore; was to accurately estimate the HBV prevalence for the country and the prevalence for specific subgroups. We used electronic databases to select systematic reviews and meta-analyses from 2000 to 2013. Forty-six studies were included (n = 34;376 persons). We used a random effects meta-analysis of cross-sectional and longitudinal studies to generate our estimates. The pooled prevalence of HBV in Nigeria was 13.6 (95 confidence interval [CI]: 11.5; 15.7). The pooled prevalence ( [95 CI]) among subgroups was: 14.0 (11.7; 16.3) for blood donors; 14.1 (9.6; 18.6) for pregnant women attending antenatal clinics; 11.5 (6.0; 17.0) for children; 14.0 (11.6; 16.5) among adults; and 16.0 (11.1; 20.9) for studies evaluating adults and children. HBV prevalence in Nigeria varied by screening method [ (95 CI)]: 12.3 (10.1; 14.4) by using enzyme-linked immunosorbent assay; 17.5 (12.4; 22.7) by immunochromatography; and 13.6 (11.5; 15.7) by HBV DNA polymerase chain reaction. HBV infection is hyperendemic in Nigeria and may be the highest in Sub-Sahara Africa. Our results suggest that large numbers of pregnant women and children were exposed to HBV from 2000 to 2013. Increased efforts to prevent new HBV infections are urgently needed in Nigeria

Nitric oxide diminishes apoptosis and p53 gene expression after renal ischemia and reperfusion injury.

BACKGROUND: The role of nitric oxide in the ischemic injury of the kidney is still controversial. The aim of this study was to reevaluate the beneficial effect of exogenous nitric oxide and define its effects as regulator of gene p53 expression and apoptosis in the ischemic renal injury. METHODS: Sprague-Dawley rats were subjected to 75 min of renal warm ischemia and contralateral nephrectomy. The animals were divided into six groups (n=6 per group): Two sham groups at 4 and 24 hr, two ischemic control (IC) at same times and two treated groups (Na-NP), studied at same intervals, where sodium nitroprusside (5 mg/kg) was given 15 min before reperfusion. The parameters evaluated included: serum creatinine, blood urea nitrogen, neutrophil infiltration determined by myeloperoxidase, gene p53 expression determined by reverse transcriptase polymerase chain reaction, apoptosis determined by peroxidase in situ technique and light histology. RESULTS: There were significant improvements in serum creatinine and blood urea nitrogen at 24 hr in the NA-NP group when compared with the IC group (P<0.05). Myeloperoxidase levels were higher in the IC when evaluated against the Na-NP groups. Na-NP exhibited a downregulating effect in the expression of gene p53 when compared to the IC group. Apoptosis was more evident in the IC group and had moderately increased histological damage when compared to the Na-NP group. CONCLUSIONS: Nitric oxide demonstrated a protective effect in the ischemic injury of the kidney and exerted an antiapoptotic action dowregulating the expression of gene p53.

Optimized fixation and storage conditions for FISH analysis of single-cell suspensions.

In our protocol to isolate and identify fetal cells in maternal peripheral blood, antibody (Ab)-stained cells are preserved with paraformaldehyde (PF) before batch flow cytometric sorting. However, PF fixation compromises the quality of subsequent interphase fluorescence in situ hybridization (FISH). We therefore examined the effect of PF concentrations and storage time in phosphate-buffered saline (PBS) on the quality of FISH signals. Cells were analyzed for changes in light scatter, morphology, and accessibility of target cell DNA. Fixation in 3% PF for 1 hr was ideal for both flow cytometry and subsequent FISH detection. However, beyond 10 days of storage, FISH quality deteriorated. (J Histochem Cytochem 46:971-973, 1998)

Large-scale purification and characterization of recombinant fibroblast growth factor-saporin mitotoxin.

In order to produce sufficient quantities of fibroblast growth factor-saporin (rFGF-2-SAP) mitotoxin for preclinical evaluation in models of diseases such as cancer and restenosis, we have undertaken the large-scale expression, purification, and characterization of the recombinant molecule. The fusion gene encoding rFGF-2-SAP was cloned into the inducible pET 11a expression vector and transformed into Escherichia coli strain BL21 (DE3). The transformants were grown using a fed-batch fermentation until the A600 reached 85. At this stage, induction of the expression of the fusion protein led to the production of approximately 2.2 mg/liter per A600 unit. The soluble mitotoxin was purified to homogeneity from cell lysates via expanded bed adsorption chromatography followed by cation-exchange, heparin-affinity, and size-exclusion chromatography. Purified rFGF-2-SAP contained less than 0.5 EU/mg of endotoxin, as determined by gel clot analyses. The highly purified rFGF-2-SAP retained the toxin's ability to inhibit protein synthesis as measured in a cell-free system and was cytotoxic to a number of normal and neoplastic cell lines bearing FGF receptors. Binding studies establish that the fusion protein exerts its effects via the FGF high-affinity receptor.

Synthesis and characterization of a homogeneous chemical conjugate between basic fibroblast growth factor and saporin.

Basic fibroblast growth factor (FGF-2) and saporin were chemically conjugated using the crosslinker, N-succinimidyl-3(2-pyridyldithio)-propionate. When purified, the conjugate was found to be heterogeneous as analyzed by SDS/PAGE, size-exclusion HPLC and reverse-phase HPLC. Therefore, we sought to synthesize a molecule that would be homogeneous and thus easier to characterize and evaluate its efficacy and toxicity for pharmaceutical drug development. A homogeneous chemical conjugate was successfully synthesized by using a mutant FGF-2 with Cys96 replaced by Ser ([S96]FGF-2) and a recombinant saporin mutant containing a single Cys at the -1 position (C-SAP). The latter was expressed in Escherichia coli and isolated to 99% purity by expanded-bed adsorption chromatography followed by cation-exchange chromatography. The cysteine in C-SAP was activated by Ellman's reagent and then reacted with the only available cysteine (position 78) in [S96]FGF-2 to produce the homogeneous conjugate, designated as FGF2-C-SAP. The purified FGF2-C-SAP was more than 98% pure as judged by HPLC. In vitro biological assays indicated that FGF2-C-SAP was a potent inhibitor of protein synthesis in a cell-free system and was cytotoxic to FGF-receptor-bearing cells.

Effect of hydrodynamic interactions on the diffusion of integral membrane proteins: tracer diffusion in organelle and reconstituted membranes.

A persistent discrepancy exists between theoretical predictions and experimental observations for the diffusion coefficients of integral membrane proteins in lipid bilayers free of immobilized proteins. Current thermodynamic theories overestimate tracer diffusion coefficients at high area fractions. We explore the hypothesis that the combined effect of hydrodynamic and thermodynamic interactions reconciles theory with experiment. We have determined previously the short- and long-time tracer diffusivities, Ds and Dl, respectively, of integral membrane proteins in lipid bilayers as a function of their area fraction, phi. The results are based on two-particle hydrodynamic and thermodynamic interactions and are precise to O(phi). Here we extend the results for Dl to high phi by combining the hydrodynamic results for Ds into theories for Dl based on many-particle thermodynamic interactions. The results compare favorably with the experimental measurements of Dl as a function of protein area fraction for bacteriorhodopsin in reconstituted membranes and for complex III of the mitochondrial inner membrane. The agreement suggests that both hydrodynamic and thermodynamic interactions are important determinants of diffusion coefficients of proteins in lipid bilayers. Additional experiments are required to verify the role of hydrodynamic interactions in protein diffusion in reconstituted systems.

Effect of hydrodynamic interactions on the diffusion of integral membrane proteins: diffusion in plasma membranes.

Tracer diffusion coefficients of integral membrane proteins (IMPs) in intact plasma membranes are often much lower than those found in blebbed, organelle, and reconstituted membranes. We calculate the contribution of hydrodynamic interactions to the tracer, gradient, and rotational diffusion of IMPs in plasma membranes. Because of the presence of immobile IMPs, Brinkman's equation governs the hydrodynamics in plasma membranes. Solutions of Brinkman's equation enable the calculation of short-time diffusion coefficients of IMPs. There is a large reduction in particle mobilities when a fraction of them is immobile, and as the fraction increases, the mobilities of the mobile particles continue to decrease. Combination of the hydrodynamic mobilities with Monte Carlo simulation results, which incorporate excluded area effects, enable the calculation of long-time diffusion coefficients. We use our calculations to analyze results for tracer diffusivities in several different systems. In erythrocytes, we find that the hydrodynamic theory, when combined with excluded area effects, closes the gap between existing theory and experiment for the mobility of band 3, with the remaining discrepancy likely due to direct obstruction of band 3 lateral mobility by the spectrin network. In lymphocytes, the combined hydrodynamic-excluded area theory provides a plausible explanation for the reduced mobility of sIg molecules induced by binding concanavalin A-coated platelets. However, the theory does not explain all reported cases of "anchorage modulation" in all cell types in which receptor mobilities are reduced after binding by concanavalin A-coated platelets. The hydrodynamic theory provides an explanation of why protein lateral mobilities are restricted in plasma membranes and why, in many systems, deletion of the cytoplasmic tail of a receptor has little effect on diffusion rates. However, much more data are needed to test the theory definitively. We also predict that gradient and tracer diffusivities are the same to leading order. Finally, we have calculated rotational diffusion coefficients in plasma membranes. They decrease less rapidly than translational diffusion coefficients with increasing protein immobilization, and the results agree qualitatively with the limited experimental data available.

Royal Naval Medical Staff School--an update.

Four significant changes in the training of RN Medical and Nursing personnel have taken place over the past four years, since training was last outlined in the article commemorating the Branch Centenary namely, the resurrection of MA training with a significantly increased throughput than previously; a relocation from Dophin II to purpose-built accommodation in the grounds of Haslar Hospital; the introduction of the QARNNS Medical Assistant, and also that of the Direct Entry QARNNS Registered General Nurse within the Rating Structure. Current training regimes and constraints are highlighted at all levels to familiarize and update the Branch with the changes and to promote a better understanding of the abilities and capabilities of the Royal Naval Medical and Nursing Services.