Role of bone marrow-derived stem cells, renal progenitor cells and stem cell factor in chronic renal allograft nephropathy

Introduction: Chronic allograft nephropathy (CAN) is a poorly understood clinico-pathological entity associated with chronic allograft loss due to immunologic and non-immunologic causes. It remains the leading cause of late allograft loss. Bone marrow derived stem cells are undifferentiated cells typically characterized by their capacity for self renewal, ability to give rise to multiple differentiated cellular population, including hematopoietic (HSCs) and mesenchymal stem cells (MSCs). Characterization of HSCs includes their multipotency, expression of typical surface markers such as CD34 and CD45, while characterization of MSC includes their multipotency, expression of typical surface markers such as CD90 and CD105, and the absence of hemopoietic lineage markers.Aim&methods: The aim of the present work was to study the role of bone marrow-derived HSCs and MSCs, renal progenitor cells and SCF in chronic renal allograft nephropathy in relation to renal hemodynamics and histopathological changes. We studied 30 patients with kidney transplantation for more than 6 months, divided into 15 patients with stable serum creatinine and 15 patients who developed CAN. Detection of HSCs and MSCs in the peripheral blood using flow cytometry via detection of CD34, CD45, CD117 and CD106, as well as immunohistochemical detection of CD34, CD133, VEGF and aSMA in transplanted kidney biopsies of patients with CAN were done.Results: There was a significant increase in the levels of SCF, number of peripheral blood HSCs and MSCs in both transplanted patient groups than the controls and they were higher in patients of group Ia than patients of group Ib, (F =39.73, P < 0.001), (F = 13.28, P< 0.001), (F= 11.94, P <0.001), respectively and this was accompanied by evident expression of markers of renal repair.Conclusion: Stem cells might have a role in renal regeneration in CAN and this may pave the way toward the use of stem cells in correction of CAN.KEYWORDS Chronic allograft nephropathy; Hematopoietic stem cells; Mesenchymal stem cells; Stem cell factor; Renal regeneratio

Tuberculosis diagnosis after bleach processing for early stage tuberculosis laboratory capacity building

The diagnosis of tuberculosis is seriously hampered in the absence of standard biosafety laboratory facilities for specimen concentration and Mycobacterium tuberculosis culture. Within a laboratory twinning arrangement,heat-fixed direct smear and sediment from 74 bleach-processed and 20 non-processed specimens from Cumura Hospital, Guinea-Bissau, were sent to Lisbon for molecular evaluation of rifampicin resistance. Sequence analysis of a 369 base-pair rpoB locus detected 3.2% (3/94) resistant specimens. To our knowledge, this represents the first report on the molecular analysis of M. tuberculosis from bleach-processed sputum, an alternative to current diagnostic practice in low-resource settings

Native valve disease in patients with non-valvular atrial fibrillation on warfarin or rivaroxaban

Objective: To compare the characteristics and outcomes of patients with atrial fibrillation (AF) and aortic stenosis (AS) with patients with AF with mitral regurgitation (MR) or aortic regurgitation (AR) and patients without significant valve disease (no SVD). Methods: Using Rivaroxaban Once-Daily, Oral, Direct Factor Xa Inhibition Compared With Vitamin K Antagonism for Prevention of Stroke and Embolism Trial in Atrial Fibrillation (ROCKET AF) data, we analysed efficacy and safety outcomes, adjusting hazard ratios (HRs) for potential confounders using Cox regression analysis. Results: Among 14 119 intention-to-treat ROCKET AF trial patients, a trial that excluded patients with mitral stenosis or artificial valve prosthesis, 214 had AS with or without other valve abnormalities, 1726 had MR or AR and 12 179 had no SVD. After adjusting for prognostic factors, the composite of stroke, systemic embolism or vascular death increased approximately twofold in patients with AS (AS 10.84, MR or AR 4.54 and no SVD 4.31 events per 100 patient-years, p=0.0001). All-cause death also significantly increased (AS 11.22, MR or AR 4.90 and no SVD 4.39 events per 100 patient-years, p=0.0003). Major bleeding occurred more frequently in AS (adjusted HR 1.61, confidence intervals (CI) 1.03 to 2.49, p<0.05) and MR or AR (HR 1.30, 1.07 to 1.57, p<0.01) than in no SVD, but there was no difference between AS and MR or AR (HR 1.24, 0.78 to 1.97). The relative efficacy of rivaroxaban versus warfarin was consistent among patients with and without valvular disease. Rivaroxaban was associated with higher rates of major bleeding than warfarin in patients with MR or AR (HR 1.63, 1.15 to 2.31). Conclusions: We found that patients with AF and AS on oral anticoagulants may have distinctly different efficacy and safety outcomes than patients with MR or AR or no SVD. Trial registration number NCT00403767; Post-results

RpoB polymorphisms in Mycobacterium tuberculosis complex from a population in Guinea-Bissau

The global tuberculosis (TB) threat is diffi cult to evaluate in countries with scarce laboratory facilities where little is known about the genetic basis of drug resistance, including the rpoB RRDR (rifampicin resistance determining region) of the Mycobacterium tuberculosis complex (MTC). The present study aimed at performing a preliminary evaluation of rpoB polymorphisms in a DNA set of MTC isolates from Guinea-Bissau patients. Ninety-four sputum specimens (74 bleach processed and 20 unprocessed) were sent to Lisbon for molecular analysis (n=94) and drug susceptibility testing (n=20). A 369bp region of the rpoB gene (including the 81bp RRDR), was amplifi ed. Sequencing was used as the gold standard for the identifi cation of point mutations. Two polymorphisms were identifi ed: The alteration S531L, present in 3.2% of the specimens, and a new mutation, present in 28.7%, corresponding to nucleotide and amino acid polymorphism C224T and S469L, respectively, detected upstream from the RRDR, and not associated with RMP resistance. An NCBI BLAST revealed M. tuberculosis K85 (M. africanum) as the only strain presenting this polymorphism. The circulation of S531L mutated stains, associated with RMP resistance, points to the urgent need to further investigate RMP resistance in this African region. Moreover, the strains presenting the S469L polymorphism showed no other mutations suggesting that its role on MP´susceptibility/ resistance or in providing a genetic background for the occurrence of RMP resistance associated mutations should be further investigated. Also, future genotyping studies could clarify whether this new mutation is a genetic signature of some M. africanum strains

Cloning and characterization of microRNAs from rainbow trout (Oncorhynchus mykiss): Their expression during early embryonic development

<p>Abstract</p> <p>Background</p> <p>Current literature and our previous results on expression patterns of oocyte-specific genes and transcription factors suggest a global but highly regulated maternal mRNA degradation at the time of embryonic genome activation (EGA). MicroRNAs (miRNAs) are small, non-coding regulatory RNAs (19–23 nucleotides) that regulate gene expression by guiding target mRNA cleavage or translational inhibition. These regulatory RNAs are potentially involved in the degradation of maternally inherited mRNAs during early embryogenesis.</p> <p>Results</p> <p>To identify miRNAs that might be important for early embryogenesis in rainbow trout, we constructed a miRNA library from a pool of unfertilized eggs and early stage embryos. Sequence analysis of random clones from the library identified 14 miRNAs, 4 of which are novel to rainbow trout. Real-time PCR was used to measure the expression of all cloned miRNAs during embryonic development. Four distinct expression patterns were observed and some miRNAs showed up-regulated expression during EGA. Analysis of tissue distribution of these miRNAs showed that some are present ubiquitously, while others are differentially expressed among different tissues. We also analyzed the expression patterns of Dicer, the enzyme required for the processing of miRNAs and Stat3, a transcription factor involved in activating the transcription of miR-21. Dicer is abundantly expressed during EGA and Stat3 is up-regulated before the onset of EGA.</p> <p>Conclusion</p> <p>This study led to the discovery of 14 rainbow trout miRNAs. Our data support the notion that Dicer processes miRNAs and Stat3 induces expression of miR-21 and possibly other miRNAs during EGA. These miRNAs in turn guide maternal mRNAs for degradation, which is required for normal embryonic development.</p

Anisotropy dependence of the fluctuation spectroscopy in the critical and gaussian regimes in superconducting NaFe1-xCoxAs single crystals

We investigate thermal fluctuations in terms of diamagnetism and magnetotransport in superconducting NaFe1-xCoxAs single crystals with different doping levels. Results show that in the case of optimal doped and lightly overdoped (x= 0.03, 0.05) crystals the analysis in the critical as well as in the Gaussian fluctuation regions is consistent with the Ginzburg-Landau 3D fluctuation theory. However, in the case of strongly overdoped samples (x &gt;= 0.07) the Ullah-Dorsey scaling of the fluctuation induced magnetoconductivity in the critical region confirms that thermal fluctuations exhibit a 3D anisotropic nature only in a narrow temperature region around T-c(H). This is consistent with the fact that in these samples the fluctuation effects in the Gaussian region above T-c may be described by the Lawrence-Doniach approach. Our results indicate that the anisotropy of these materials increases significantly with the doping level

Soluble egg antigen of Schistosoma Haematobium induces HCV replication in PBMC from patients with chronic HCV infection

BACKGROUND: This study was conducted to examine, in vitro , the effect of soluble egg antigen (SEA) of S. haematobium on intracellular HCV RNA load in peripheral mononuclear cells (PBMC) as well as on cell proliferation in patients with chronic HCV infection. METHODS: PBMC from 26 patients with chronic HCV infection were cultured for 72 hours in presence and absence of 50 μg SEA/ml medium. Intracellular HCV RNA quantification of plus and minus strands was assessed before and after stimulation. PBMC from five healthy subjects were cultured for 7 days, flow cytometric analysis of DNA content was used to assess the mitogenic effect of SEA on PBMC proliferation compared to phytoheamaglutinine (PHA). RESULTS: Quantification of the intracellular viral load showed increased copy number/cell of both or either viral strands after induction with SEA in 18 of 26 patients (69.2%) thus indicating stimulation of viral replication. Flow cytometric analysis showed that mean ± S.D. of percent values of cell proliferation was induced from 3.2 ± 1.5% in un-stimulated cells to 16.7 ± 2.5 % and 16.84 ± 1.7 % in cells stimulated with PHA and SEA respectively. CONCLUSION: the present study supports earlier reports on SEA proliferative activity on PBMC and provides a strong evidence that the higher morbidity observed in patients co-infected with schistosomiasis and HCV is related, at least in part, to direct stimulation of viral replication by SEA

Contrasting Spatial Distribution and Risk Factors for Past Infection with Scrub Typhus and Murine Typhus in Vientiane City, Lao PDR

Scrub typhus and murine typhus are neglected but important treatable causes of fever, morbidity and mortality in South-East Asia. Epidemiological data suggests that scrub typhus would be more common in rural areas and murine typhus in urban areas but there are very few comparative data from places where both diseases occur, as is the case in Vientiane, the capital of the Lao PDR. We therefore determined the frequency of IgG antibody seropositivity against scrub typhus and murine typhus, as indices of prior exposure to these pathogens, in a randomly selected population of 2,002 adults living in different neighbourhoods in Vientiane. The overall prevalence of IgG against these two pathogens was ∼20%. However, within the city, the spatial distribution of IgG against these two diseases was radically different - past exposure to murine typhus being more frequent in urbanized areas while past exposure to scrub typhus more frequent in outlying areas. This study underscores the importance of ecological characteristics in improving the understanding of both scrub typhus and murine typhus transmission and epidemiology