The emergence of dyslexia in the developing brain.

Developmental dyslexia, a severe deficit in literacy learning, is a neurodevelopmental learning disorder. Yet, it is not clear whether existing neurobiological accounts of dyslexia capture potential predispositions of the deficit or consequences of reduced reading experience. Here, we longitudinally followed 32 children from preliterate to school age using functional and structural magnetic resonance imaging techniques. Based on standardised and age-normed reading and spelling tests administered at school age, children were classified as 16 dyslexic participants and 16 controls. This longitudinal design allowed us to disentangle possible neurobiological predispositions for developing dyslexia from effects of individual differences in literacy experience. In our sample, the disorder can be predicted already before literacy learning from auditory cortex gyrification and aberrant downstream connectivity within the speech processing system. These results provide evidence for the notion that dyslexia may originate from an atypical maturation of the speech network that precedes literacy instruction.

Mesenchymal Stem Cell-Derived Microvesicles Modulate Lipopolysaccharides-Induced Inflammatory Responses to Microglia Cells.

Microglia cells are the central nervous system immune cells and have been pointed out as the main mediators of the inflammation leading to neurodegenerative disorders. Mesenchymal stromal cells (MSCs) are a heterogeneous population of cells with very high self-renewal properties and uncomplicated in vitro culture. Research has shown that MSCs have the capacity to induce tissue regeneration and reduce inflammation. Studies demonstrated that MSCs have complex paracrine machineries involving shedding of cell-derived microvesicles (MVs), which entail part of the regulatory and regenerative activity of MSCs, as observed in animal models. We proposed MSC-derived MVs as potent regulators of microglia activation and used an in vitro model of stimulation for BV-2 cells, a microglia cell line, with lipopolysaccharides (LPS). Here we demonstrated that presence of MSCs-derived MVs (MSC-MVs) prevents Tumor necrosis factor-α, Interleukin (IL)-1ß and IL-6 upregulation by BV-2 cells and primary microglia cells toward LPS. Also, inducible isoform of nitric oxide synthases and Prostaglandin-endoperoxide synthase 2 upregulation were hampered in presence of MSC-MVs. Higher levels of the M2 microglia marker chemokine ligand-22 were detectable in BV-2 cells after coculture with MSC-MVs in presence and absence of LPS. Moreover, upregulation of the activation markers CD45 and CD11b by BV-2 cells was prevented when cocultured with MSC-MVs. Furthermore, MSC-MVs suppressed the phosphorylation of the extracellular signal kinases 1/2, c-Jun N-terminal kinases and the p38 MAP kinase (p38) molecules. Consequently, MSC-MVs might represent a modulator of microglia activation with future therapeutic impact. Stem Cells 2017;35:812-823.

Attenuation of graft-versus-host-disease in NOD scid IL-2Rγ(-/-) (NSG) mice by ex vivo modulation of human CD4(+) T cells.

NOD.Cg-Prkdc(scid) IL-2rg(tm1Wjl) /SzJ (NSG) mice are a valuable tool for studying Graft-versus-Host-Disease (GvHD) induced by human immune cells. We used a model of acute GvHD by transfer of human peripheral blood mononuclear cells (PBMCs) into NSG mice. The severity of GvHD was reflected by weight loss and was associated with engraftment of human cells and the expansion of leukocytes, particularly granulocytes and monocytes. Pre-treatment of PBMCs with the anti-human CD4 antibody MAX.16H5 IgG1 or IgG4 attenuated GvHD. The transplantation of 2 × 10(7) PBMCs without anti-human CD4 pre-treatment induced a severe GvHD (0% survival). In animals receiving 2 × 10(7) PBMCs pre-incubated with MAX.16H5 IgG1 or IgG4, GvHD development was reduced and survival was increased. Immune reconstitution was measured by flow cytometry and confirmed for human leukocytes (CD45), CD3(+) /CD8(+) cytotoxic T cells and CD3(+) /CD4(+) T helper cells. Human B cells (CD19) and monocytes (CD14) could not be detected. Histopathological analysis (TUNEL assay) of the gut of recipient animals showed significantly less apoptotic crypt cells in animals receiving a MAX.16H5 IgG1 pre-incubated graft. These findings indicate that pre-incubation of an allogeneic graft with an anti-human CD4 antibody may decrease the frequency and severity of GvHD after hematopoietic stem cell transplantation (HSCT) and the need of conventional immunosuppressive drugs. Moreover, this approach most probably provides a safer HSCT that must be confirmed in appropriate clinical trials in the future. © 2016 International Society for Advancement of Cytometry.

Genetic dyslexia risk variant is related to neural connectivity patterns underlying phonological awareness in children.

Phonological awareness is the best-validated predictor of reading and spelling skill and therefore highly relevant for developmental dyslexia. Prior imaging genetics studies link several dyslexia risk genes to either brain-functional or brain-structural factors of phonological deficits. However, coherent evidence for genetic associations with both functional and structural neural phenotypes underlying variation in phonological awareness has not yet been provided. Here we demonstrate that rs11100040, a reported modifier of SLC2A3, is related to the functional connectivity of left fronto-temporal phonological processing areas at resting state in a sample of 9- to 12-year-old children. Furthermore, we provide evidence that rs11100040 is related to the fractional anisotropy of the arcuate fasciculus, which forms the structural connection between these areas. This structural connectivity phenotype is associated with phonological awareness, which is in turn associated with the individual retrospective risk scores in an early dyslexia screening as well as to spelling. These results suggest a link between a dyslexia risk genotype and a functional as well as a structural neural phenotype, which is associated with a phonological awareness phenotype. The present study goes beyond previous work by integrating genetic, brain-functional and brain-structural aspects of phonological awareness within a single approach. These combined findings might be another step towards a multimodal biomarker for developmental dyslexia.

Flow cytometric analysis of the graft-versus-Leukemia-effect after hematopoietic stem cell transplantation in mice.

Acute Graft-versus-Host-Disease (aGvHD) is one of the major complications following allogeneic hematopoietic stem cell transplantation (HSCT). Although rather helpful, the use of conventional immunosuppressive drugs leads to general immunosuppression and is toxic. The effects of CD4(+) T-cells, in respect to the development of aGvHD, can be altered by administration of antihuman CD4 monoclonal antibodies, here MAX.16H5 IgG1 . This approach must be tested for possible interference with the Graft-versus-Leukemia-Effect (GvL). Thus, in vitro experiments were conducted, exposing P815 leukemic cells to bone marrow and splenocytes from cd4(-/-) -C57Bl/6 mice transgenic for human CD4 and HLA-DR3 (triple transgenic mice, [TTG]) as well as previously irradiated splenocytes from Balb/c(wt) mice. Using flow cytometry, the vitality of the various malignant and graft cells was analyzed over the course of 4 days. The survival rate of P815 cells did not change significantly when exposed to MAX.16H5 IgG1 , neither did the viability of the graft cells. This provides evidence that MAX.16H5 IgG1 does not impair the GvL effect in vitro. Additionally, P815-Balb/c(wt) leukemic mice were transplanted with P815(GFP) cells, bone marrow, and splenocytes from TTG mice with and without MAX.16H5 IgG1 . Without transplantation, P815(GFP) leukemic cells could be detected by flow cytometry in the liver, the bone marrow, and the spleen of recipients. The antibodies prevented aGvHD while leaving the GvL effect intact. These findings indicate no negative effect of MAX.16H5 IgG1 on the GvL effect in vitro and in vivo after HSCT in a murine model.

Prevention of graft-versus-host-disease with preserved graft-versus-leukemia-effect by ex vivo and in vivo modulation of CD4(+) T-cells.

This is the first report showing that an epitope-specific ex vivo modulation of an allogeneic hematopoietic stem cell graft by the anti-human CD4 antibody MAX.16H5 IgG1 simultaneously facilitates the anti-tumor capacity of the graft (Graft-versus-leukemia effect, GvL) and the long-term suppression of the deleterious side effect Graft-versus-host-disease (GvHD). To distinguish and consolidate GvL from GvHD, the anti-human CD4 antibody MAX16.H5 IgG1 was tested in murine GvHD and tumor models. The survival rate was significantly increased in recipients receiving a MAX.16H5 IgG1 short-term (2 h) pre-incubated graft even when tumor cells were co-transplanted or when recipient mice were treated by MAX.16H5 IgG1 before transplantation. After engraftment, regulatory T-cells are generated only supporting the GvL effect. It was also possible to transfer the immune tolerance from GvHD-free recipient chimeras into third party recipient mice without the need of reapplication of MAX.16H5 IgG1 anti-human CD4 antibodies. These findings are also benefical for patients with leukemia when no matched related or unrelated donor is available and provides a safer allogeneic HSCT, which is more effective against leukemia. It also facilitates allogeneic (stem) cell transplantations for other indications (e.g., autoimmune-disorders).

Molecular epidemiology and transmission dynamics of Mycobacterium tuberculosis in Northwest Ethiopia: new phylogenetic lineages found in Northwest Ethiopia.

BACKGROUND: Although Ethiopia ranks seventh among the world's 22 high-burden tuberculosis (TB) countries, little is known about strain diversity and transmission. In this study, we present the first in-depth analysis of the population structure and transmission dynamics of Mycobacterium tuberculosis strains from Northwest Ethiopia. METHODS: In the present study, 244 M. tuberculosis isolates where analysed by mycobacterial interspersed repetitive unit - variable number tandem repeat 24-loci typing and spoligotyping methods to determine phylogenetic lineages and perform cluster analysis. Clusters of strains with identical genotyping patterns were considered as an indicator for the recent transmission. RESULTS: Of 244 isolates, 59.0% were classified into nine previously described lineages: Dehli/CAS (38.9%), Haarlem (8.6%), Ural (3.3%), LAM (3.3%), TUR (2.0%), X-type (1.2%), S-type (0.8%), Beijing (0.4%) and Uganda II (0.4%). Interestingly, 31.6% of the strains were grouped into four new lineages and were named as Ethiopia_3 (13.1%), Ethiopia_1 (7.8%), Ethiopia_H37Rv like (7.0%) and Ethiopia_2 (3.7%) lineages. The remaining 9.4% of the isolates could not be assigned to the known or new lineages. Overall, 45.1% of the isolates were grouped in clusters, indicating a high rate of recent transmission. CONCLUSIONS: This study confirms a highly diverse M. tuberculosis population structure, the presence of new phylogenetic lineages and a predominance of the Dehli/CAS lineage in Northwest Ethiopia. The high rate of recent transmission indicates defects of the TB control program in Northwest Ethiopia. This emphasizes the importance of strengthening laboratory diagnosis of TB, intensified case finding and treatment of TB patients to interrupt the chain of transmission.

Allogeneic bone marrow grafts with high levels of CD4(+) CD25(+) FoxP3(+) T cells can lead to engraftment failure.

Regulatory CD4(+) CD25(+) FoxP3(+) T cells (T(regs) ) suppress immunological reactions. However, the effect of adding T(regs) to hematopoietic stem cell grafts on recovery and graft versus host disease (GvHD) is unknown. T(regs) from splenocytes of C57Bl/6 and Balb/c wild-type mice were isolated by MACS separation and analyzed by flow cytometry. Using a murine syngeneic transplantation model that clearly distinguishes between donor and host hematopoiesis, we showed that co-transplantation of bone marrow cells (BMCs) with high levels of T(regs) leads to a 100% survival of the mice and accelerates the hematopoietic recovery significantly (full donor chimerism). In allogeneic transplantation, bone marrow and T(regs) co-transplantation were compared to allogeneic bone marrow transplantation with or without the addition of splenocytes. Survival, leukocyte recovery, chimerism at days -2, 19, 33, and 61 for murine CD4, human CD4, HLA-DR3, murine CD3, murine CD8, murine Balb/c-H2K(d) , murine C57Bl/6-H2K(b) , and GvHD appearance were analyzed. Allogeneic bone marrow transplantation requires the addition of splenocytes to reach engraftment. Mice receiving grafts with bone marrow, splenocytes and high levels of allogeneic T(regs) died within 28 days (hematopoietic failure). Here, we show also detailed flow cytometric data reagarding analysis of chimerism after transplantation in unique murine hematopoietic stem cell transplantation models. Our findings showed that the syngeneic co-transplantation of CD4(+) , CD25(+) , FoxP3(+) T-cells and BMCs induced a stimulating effect on reconstitution of hematopoiesis after irradiation. However, in the allogeneic setting the co-transplantation of T(regs) aggravates the engraftment of transplanted cells.

Xenogenic esophagus scaffolds fixed with several agents: comparative in vivo study of rejection and inflammation.

Most infants with long-gap esophageal atresia receive an esophageal replacement with tissue from stomach or colon, because the native esophagus is too short for true primary repair. Tissue-engineered esophageal conducts could present an attractive alternative. In this paper, circular decellularized porcine esophageal scaffold tissues were implanted subcutaneously into Sprague-Dawley rats. Depending on scaffold cross-linking with genipin, glutaraldehyde, and carbodiimide (untreated scaffolds : positive control; bovine pericardium : gold standard), the number of infiltrating fibroblasts, lymphocytes, macrophages, giant cells, and capillaries was determined to quantify the host response after 1, 9, and 30 days. Decellularized esophagus scaffolds were shown to maintain native matrix morphology and extracellular matrix composition. Typical inflammatory reactions were observed in all implants; however, the cellular infiltration was reduced in the genipin group. We conclude that genipin is the most efficient and best tolerated cross-linking agent to attenuate inflammation and to improve the integration of esophageal scaffolds into its surrounding tissue after implantation.

Analysis of gene mutations associated with isoniazid, rifampicin and ethambutol resistance among Mycobacterium tuberculosis isolates from Ethiopia.

BACKGROUND: The emergence of drug resistance is one of the most important threats to tuberculosis control programs. This study was aimed to analyze the frequency of gene mutations associated with resistance to isoniazid (INH), rifampicin (RMP) and ethambutol (EMB) among Mycobacterium tuberculosis isolates from Northwest Ethiopia, and to assess the performance of the GenoType® MTBDRplus and GenoType® MTBDRsl assays as compared to the BacT/ALERT 3D system. METHODS: Two hundred sixty Mycobacterium tuberculosis isolates from smear positive tuberculosis patients diagnosed between March 2009 and July 2009 were included in this study. Drug susceptibility tests were performed in the Institute of Medical Microbiology and Epidemiology of Infectious Diseases, University Hospital of Leipzig, Germany. RESULTS: Of 260 isolates, mutations conferring resistance to INH, RMP, or EMB were detected in 35, 15, and 8 isolates, respectively, while multidrug resistance (MDR) was present in 13 of the isolates. Of 35 INH resistant strains, 33 had mutations in the katG gene at Ser315Thr 1 and two strains had mutation in the inhA gene at C15T. Among 15 RMP resistant isolates, 11 had rpoB gene mutation at Ser531Leu, one at His526Asp, and three strains had mutations only at the wild type probes. Of 8 EMB resistant strains, two had mutations in the embB gene at Met306Ile, one at Met306Val, and five strains had mutations only at the wild type probes. The GenoType® MTBDRplus assay had a sensitivity of 92% and specificity of 99% for INH resistance, and 100% sensitivity and specificity to detect RMP resistance and MDR. The GenoType® MTBDRsl assay had a sensitivity of 42% and specificity of 100% for EMB resistance. CONCLUSION: The dominance of single gene mutations associated with the resistance to INH and RMP was observed in the codon 315 of the katG gene and codon 531 of the rpoB gene, respectively. The GenoType® MTBDRplus assay is a sensitive and specific tool for diagnosis of resistance to INH, RMP and MDR. However, the GenoType® MTBDRsl assay shows limitations in detecting resistance to EMB.

Extracellular Vesicles of Mesenchymal Stromal Cells Can be Taken Up by Microglial Cells and Partially Prevent the Stimulation Induced by ß-amyloid.

Mesenchymal stromal/stem cells (MSCs) have great capacity for immune regulation. MSCs provide protective paracrine effects, which are partially exerted by extracellular vesicles (EVs). It has been reported that MSCs-derived EVs (MSC-EVs) contain soluble factors, such as cytokines, chemokines, growth factors and even microRNAs, which confer them similar anti-inflammatory and regenerative effects to MSCs. Moreover, MSCs modulate microglia activation through a dual mechanism of action that relies both on cell contact and secreted factors. Microglia cells are the central nervous system immune cells and the main mediators of the inflammation leading to neurodegenerative disorders. Here, we investigated whether MSC-EVs affect the activation of microglia cells by ß-amyloid aggregates. We show that the presence of MSC-EVs can prevent the upregulation of pro-inflammatory mediators such as tumor necrosis factor (TNF)-α and nitric oxide (NO). Both are up-regulated in neurodegenerative diseases representing chronic inflammation, as in Alzheimer's disease. We demonstrate that MSC-EVs are internalized by the microglia cells. Further, our study supports the use of MSC-EVs as a promising therapeutic tool to treat neuroinflammatory diseases.Significance StatementIt has been reported that mesenchymal stromal/stem cells and MSC-derived small extracellular vesicles have therapeutic effects in the treatment of various degenerative and inflammatory diseases. Extracellular vesicles are loaded with proteins, lipids and RNA and act as intercellular communication mediators. Here we show that extracellular vesicles can be taken up by murine microglial cells. In addition, they partially reduce the activation of microglial cells against ß-amyloid aggregates. This inhibition of microglia activation may present an effective strategy for the control/therapy of neurodegenerative diseases such as Alzheimer's disease.

Rate of recovery of Mycobacterium tuberculosis from frozen acid-fast-bacillus smear-positive sputum samples subjected to long-term storage in Northwest Ethiopia.

Tuberculosis is a major public health problem in Ethiopia. The diagnosis and treatment of drug-resistant tuberculosis remain a challenge in the country. This study aimed to assess whether single morning sputum samples could be stored at -20 °C for extended periods of time at remote settings and then transported and successfully cultured for Mycobacterium tuberculosis. Single morning sputum samples were collected from all smear-positive tuberculosis patients diagnosed at Gondar Hospital, Gondar Health Center, Metemma Hospital, Bahir Dar Hospital, and Debre Markos Hospital in Northwest Ethiopia between March and July 2009. Specimens were stored at the study sites and sent to the mycobacteriology laboratory at the University Hospital, Leipzig, Germany, where specimens were processed and inoculated into the BacT/Alert 3D system and Lowenstein-Jensen and Gottsacker media. Ice packs were added in the package of the specimens during transport. A total of 319 patients were enrolled in this study. The median specimen storage time was 132 days (range, 16 to 180 days). Of all specimens, 283 (88.7%) were culture positive by any of the three culturing systems. M. tuberculosis isolates from four contaminated specimens in all culturing systems were successfully isolated on Middlebrook 7H10 agar; thereby, the recovery rate increased to 287 (90.0%). The length of time of sputum storage had no significant effect on the rate of recovery of M. tuberculosis in all culturing systems. In conclusion, single morning sputum specimens collected at remote settings stored at -20 °C for long periods of time without the addition of preservatives can yield a high recovery rate. These findings suggest a simple and cost-effective alternative method of sputum storage for epidemiological and drug resistance studies in low-resource countries.

Increased CD64 expression on polymorphonuclear neutrophils indicates infectious complications following solid organ transplantation.

The aim of this study was to evaluate the diagnostic value of monitoring CD64 antigen upregulation on polymorphonuclear neutrophils (PMN) for the identification of infectious complications in the postoperative course of solid organ transplanted patients. Twenty-five kidney, 13 liver, and four pancreas-kidney transplanted patients were included. Beginning with preoperative values up to postoperative values after 3 months for each patient, the PMN CD64 Index, HLA-DR on monocytes, NKp44+ NK and NK/T cells, CXCR3+ NK cells, CXCR3+ T helper cells, CXCR3+ NK/T cells, and CD4/CD8 ratio were measured by flow cytometry. Subsequently they were correlated with confirmed postoperative complications. Measuring the PMN CD64 Index reached a sensitivity of 89% and a specificity of 65% in the detection of infectious complications. Concerning this matter, it was a significantly better marker than all other included parameters except CXCR3+ NK/T cells. In contrast, according to our results the PMN CD64 Index has no diagnostic relevance in detection of rejections. The combination of included parameters showed no improved diagnostic value. Due to its high sensitivity and specificity for infectious complications CD64 on PMN could be proven a very good indicator in evaluating suspected infectious complications in the postoperative course of transplanted patients.

Characterization of murine non-adherent bone marrow cells leading to recovery of endogenous hematopoiesis.

Non-adherent bone marrow-derived cells (NA-BMCs) are a mixed cell population that can give rise to multiple mesenchymal phenotypes and that facilitates hematopoietic recovery. We characterized NA-BMCs by flow cytometry, fibroblast colony-forming units (CFU-f), real-time PCR, and in in vivo experiments. In comparison to adherent cells, NA-BMCs expressed high levels of CD11b(+) and CD90(+) within the CD45(+) cell fraction. CFU-f were significantly declining over the cultivation period, but NA-BMCs were still able to form CFU-f after 5 days. Gene expression analysis of allogeneic NA-BMCs compared to bone marrow (BM) indicates that NA-BMCs contain stromal, mesenchymal, endothelial cells and monocytes, but less osteoid, lymphoid, and erythroid cells, and hematopoietic stem cells. Histopathological data and analysis of weight showed an excellent recovery and organ repair of lethally irradiated mice after NA-BMC transplantation with a normal composition of the BM.

Seroprevalence of HIV, HBV, HCV and syphilis infections among blood donors at Gondar University Teaching Hospital, Northwest Ethiopia: declining trends over a period of five years.

BACKGROUND: Transfusion-transmissible infectious agents such as human immunodeficiency virus (HIV), hepatitis B virus (HBV), hepatitis C virus (HCV) and syphilis are among the greatest threats to blood safety for the recipient. This study aimed to determine the seroprevalence, risk factors and trends of HIV, HBV, HCV and syphilis infections among blood donors over a period of five years at Gondar University Teaching Hospital, Northwest Ethiopia. METHODS: A retrospective analysis of consecutive blood donors' records covering the period between January 2003 and December 2007 was conducted. Logistic regression analysis was used to determine risk factors associated with HIV, HBV, HCV and syphilis infections. RESULTS: From the total of 6361 consecutive blood donors, 607 (9.5%) had serological evidence of infection with at least one pathogen and 50 (0.8%) had multiple infections. The overall seroprevalence of HIV, HBV, HCV and syphilis was 3.8%, 4.7%, 0.7%, and 1.3% respectively. Among those with multiple infections, the most common combinations were HIV-syphilis 19 (38%) and HIV-HBV 17 (34%). The seropositivity of HIV was significantly increased among female blood donors, first time donors, housewives, merchants, soldiers, drivers and construction workers. Significantly increased HBV seropositivity was observed among farmers, first time donors and age groups of 26 - 35 and 36 - 45 years. Similarly, the seroprevalence of syphilis was significantly increased among daily labourers and construction workers. Statistically significant association was observed between syphilis and HIV infections, and HCV and HIV infections. Moreover, significantly declining trends of HIV, HCV and syphilis seropositivity were observed over the study period. CONCLUSIONS: A substantial percentage of the blood donors harbour HIV, HBV, HCV and syphilis infections. Strict selection of blood donors and comprehensive screening of donors' blood using standard methods are highly recommended to ensure the safety of blood for recipient.

Magnitude and determinants of nonadherence and nonreadiness to highly active antiretroviral therapy among people living with HIV/AIDS in Northwest Ethiopia: a cross-sectional study.

BACKGROUND: Adequate antiretroviral drug potency is essential for obtaining therapeutic benefit, however, the behavioral aspects of proper adherence and readiness to medication, often determine therapeutic outcome. Therefore, this study aimed to assess the level and determinants of nonadherence and nonreadiness to highly active antiretroviral therapy (HAART) among people living with HIV/AIDS (PLWHA) at Gondar University Teaching Hospital and Felege Hiwot Hospital in Northwest Ethiopia. METHODS: A cross-sectional study was conducted between July and September 2008 using structured interviewer-administered questionnaire. All consecutive adult outpatients who were receiving antiretroviral treatment for at least three months, seen at both hospitals during the study period and able to give informed consent were included in the study. Multivariate logistic regression was used to determine factors associated with nonadherence and nonreadiness. RESULTS: A total of 504 study subjects were included in this study. The prevalence rates of nonadherence and nonreadiness to HAART were 87 (17.3%) and 70 (13.9%) respectively. Multivariate logistic regression analysis revealed that medication adverse effects, nonreadiness to HAART, contact with psychiatric care service and having no goal had statistically significant association with nonadherence. Moreover, unwillingness to disclose HIV status was significantly associated with nonreadiness to HAART. CONCLUSIONS: In this study the level of nonadherence and nonreadiness to HAART seems to be encouraging. Several factors associated with nonadherance and nonreadiness to HAART were identified. Efforts to minimize nonadherence and nonreadiness to HAART should be integrated in to regular clinical follow up of patients.

Treatment outcome of tuberculosis patients at Gondar University Teaching Hospital, Northwest Ethiopia. A five--year retrospective study.

BACKGROUND: In Gondar University Teaching Hospital standardized tuberculosis prevention and control programme, incorporating Directly Observed Treatment, Short Course (DOTS) started in 2000. According to the proposal of World Health Organization (WHO), treatment outcome is an important indicator of tuberculosis control programs. This study investigated the outcome of tuberculosis treatment at Gondar University Teaching Hospital in Northwest Ethiopia. METHODS: We analyzed the records of 4000 tuberculosis patients registered at Gondar University Teaching Hospital from September 2003 to May 2008. Treatment outcome and tuberculosis type were categorized according to the national tuberculosis control program guideline. Multivariate analysis using logistic regression model was used to analyse the association between treatment outcome and potential predictor variables. RESULTS: From the total of 4000 patients, tuberculosis type was categorized as extrapulmonary in 1133 (28.3%), smear negative pulmonary tuberculosis in 2196 (54.9%) and smear positive pulmonary tuberculosis in 671 (16.8%) cases. Of all patients, treatment outcome was classified as successfully treated in 1181(29.5%), defaulted in 730 (18.3%), died in 403 (10.1%), treatment failed in six (0.2%) and transferred out in 1680 (42.0%) patients. Males had the trend to be more likely to experience death or default than females, and the elderly were more likely to die than younger. The proportion of default rate was increased across the years from 97(9.2%) to 228(42.9%). Being female, age group 15-24 years, smear positive pulmonary tuberculosis and being urban resident were associated with higher treatment success rate. CONCLUSION: The treatment success rate of tuberculosis patients was unsatisfactorily low (29.5%). A high proportion of patients died (10.1%) or defaulted (18.3%), which is a serious public health concern that needs to be addressed urgently.

Complementary strategies to elucidate T helper cell epitopes in myasthenia gravis.

CD4(+) T cells specific for the acetylcholine receptor (AChR) are assumed to play an important role in pathogenesis of myasthenia gravis (MG). A large and diverse number of potential T cell epitopes have been reported for different experimental setups aiming at the identification of disease-relevant T cells in MG. Investigating the T cell response to the epsilon subunit of human AChR, we explore complementary in vitro and in vivo approaches (PBMC from MG patients and mice transgenic for HLA-DR3 and human CD4) to address the possibilities and limitations of different strategies for elucidating natural autoimmune T cell epitopes.

Effect of progenitor cells on myocardial perfusion and metabolism in patients after recanalization of a chronically occluded coronary artery.

UNLABELLED: Even after recanalization of a chronic total coronary occlusion, functional recovery is incomplete and parts of the myocardium remain hypoperfused. In this randomized, placebo-controlled, and double-blinded study, we investigated relative changes in myocardial perfusion and glucose metabolism induced by intracoronary administration of blood-derived circulating progenitor cells (CPCs), compared with the natural course in a control group after recanalization of total coronary occlusion. METHODS: After recanalization of total coronary occlusion, 26 patients were randomly assigned to the CPC treatment or placebo group. Regional myocardial perfusion and glucose metabolism were assessed by 99mTc-tetrofosmin SPECT and 18F-FDG PET at baseline (after recanalization of total coronary occlusion) and 3 mo after the administration of 69 +/- 14 x 10(6) CPCs or cell-free serum, respectively. Segments were classified as "normal," "perfusion-metabolism mismatch" (dysfunctional segments with a 99mTc-tetrofosmin-18F-FDG mismatch), or "scar." RESULTS: In contrast to the placebo group, CPC administration resulted in a significant decrease in the number of segments with a perfusion-metabolism mismatch, from 3.0 +/- 0.5 to 1.7 +/- 0.6 segments (P < 0.05 vs. baseline). Of the normal segments at baseline, 2.7% in the CPC group and 30% in the placebo group revealed a perfusion-metabolism mismatch at follow-up after 3 mo (P < 0.05 vs. placebo). CONCLUSION: Intracoronary administration of CPCs significantly reduces the amount of myocardium with a perfusion-metabolism mismatch and prevents areas with normal perfusion and metabolism after recanalization of total coronary occlusion from becoming dysfunctional during the next 3 mo. These results show that PET and SPECT can be used to monitor the effect of progenitor cells on myocardial integrity. More important, they provide evidence supporting expansion of the use of progenitor cell treatment to chronic coronary artery disease.