Gum Arabic as fetal hemoglobin inducing agent in sickle cell anemia; in vivo study

Patients who require transfusion as part of their clinical management have the right to expect sufficient blood to be available to meet their needs and to receive the safest blood possible. Donor deferrals (disqualification) lead to loss of precious blood donors and blood units available for transfusion purposes. It is believed that a large majority of donor deferrals are due to temporal and correctable causes such as anemia in developing countries. It is therefore important to determine anemia among donor population to inform decision-making on the type of measures to be taken to reduce deferrals due to anemia. The aim of the study was to determine anemia in prospective blood donors deferred by the copper sulphate technique of hemoglobin estimation. This, to provide information that would help plan a future strategy for donor recruitment and management. Three (3) ml of venous blood samples were collected from the study subjects into EDTA anticoagulant tubes. The hemoglobin levels and red cell indices were measured using Sysmex hematology analyser. A thin blood film was prepared and stained using Leishman stain and then observed under the light microscope. The prevalence of anemia among the total deferred patients (538) was 17.1 %. Four different types of anemia were found among the subjects. These were normocytic normochromic (46.74 %), microcytic hypochromic (42.39 %) normocytic hypochromic (8.70 %), and microcytic normochromic anemia (2.17 %). The study showed that a significant number of the prospective blood donors deferred for having low hemoglobin by the copper sulphate method turned out to have anemia by the standard method of diagnosis. Prevalence of anemia among apparently healthy blood donors was therefore higher than expected. Measures must therefore be taken to address this in order not to lose potential blood donors due to a correctable and preventable cause such as anemia.     

Human Decay-Accelerating Factor and CEACAM Receptor-Mediated Internalization and Intracellular Lifestyle of Afa/Dr Diffusely Adhering Escherichia coli in Epithelial Cells

We used transfected epithelial CHO-B2 cells as a model to identify the mechanism mediating internalization of Afa/Dr diffusely adhering Escherichia coli. We provide evidence that neither the α5 or β1 integrin subunits nor α5β1 integrin functioned as a receptor mediating the adhesion and/or internalization of Dr or Afa-III fimbria-positive bacteria. We also demonstrated that (i) whether or not the AfaD or DraD invasin subunits were present, there was no difference in the cell association and entry of bacteria and that (ii) DraE or AfaE-III adhesin subunits are necessary and sufficient to promote the receptor-mediated bacterial internalization into epithelial cells expressing human decay-accelerating factor (DAF), CEACAM1, CEA, or CEACAM6. Internalization of Dr fimbria-positive E. coli within CHO-DAF, CHO-CEACAM1, CHO-CEA, or CHO-CEACAM6 cells occurs through a microfilament-independent, microtubule-dependent, and lipid raft-dependent mechanism. Wild-type Dr fimbria-positive bacteria survived better within cells expressing DAF than bacteria internalized within CHO-CEACAM1, CHO-CEA, or CHO-CEACAM6 cells. In DAF-positive cells, internalized Dr fimbria-positive bacteria were located in vacuoles that contained more than one bacterium, displaying some of the features of late endosomes, including the presence of Lamp-1 and Lamp-2, and some of the features of CD63 proteins, but not of cathepsin D, and were acidic. No interaction between Dr fimbria-positive-bacterium-containing vacuoles and the autophagic pathway was observed.Diffusely adhering Escherichia coli (DAEC) organisms comprise two classes of strains, the typical DAEC and the atypical DAEC strains, each subdivided into two subclasses of strains (67). These pathogenic E. coli strains belong to group six of enterovirulent E. coli (38). Typical Afa/Dr DAEC strains have been shown to be involved in age-dependent diarrhea in infants (48, 63). Typical Afa/Dr DAEC strains have been shown to belong to the recently reported type IV pathotype of uropathogenic E. coli (UPEC) (46). Typical Afa/Dr DAEC strains are involved in urinary tract infections (UTIs), since 25 to 50% of children with cystitis and 30% of pregnant women with pyelonephritis are infected with E. coli bearing Afa/Dr fimbriae (30, 57). Moreover, typical Afa/Dr DAEC strains are involved in recurrent UTIs, and the vast majority of the typical Afa/Dr DAEC isolates (90%) are multiantibiotic resistant (29). The typical Afa/Dr DAEC strain expresses a family of genes that is organized to form a family of afa-, dra-, daa-, and/or nfa-related operons encoding Afa-I, Afa-II, Afa-III, Afa-V, Dr, Dr-II, F1845, and Nfa-I fimbriae (67). The genes are organized in similar ways, with at least five genes (A to E), of which the last, the E gene, encodes a major structural adhesin subunit (70). The D gene encodes the invasin subunit (21, 35, 72). Importantly, DraE and AfaE-III proteins display 98% sequence identity, whereas DraD and AfaD-III share 100% sequence identity. Atomic resolution models of Dr and Afa-III fibrils have revealed that the structural basis for assembly occurs by donor strand complementation and that the architecture of capped surface fibers results from the assembly of several DraE or AfaE subunits, with one invasin subunit, DraD or AfaD-III, at their distal ends (1, 14).Typical Afa/Dr fimbriae govern the adhesion of the bacteria to host epithelial cells and the cells'' responses to their presence. All these fimbriae (Afa/Dr_DAF) are able to bind specifically to the complement control protein repeats 2 and 3 (CCP2 and CCP3), domains of human decay-accelerating factor (DAF; CD55) (56). The DAF binding domain into the Afa/Dr adhesin subunit is located in its central part, localized on strands B and E of DraE (1, 31). Moreover, our group has recently reported that a subclass of Afa/Dr fimbriae, including Afa-III, Dr, and F1845 (Afa/Dr_CEACAM), recognized members of the human CEACAM family (3), which includes CEACAM1 (biliary glycoprotein; CD66a), CEA (carcinoembryonic antigen; CD66e), and CEACAM6 (nonspecific cross-reacting antigen; CD66c) (4, 27). AfaE-I, AfaE-III, AfaE-V, DraE, and DaaE adhesin subunits of Afa/Dr DAEC targeted the N-terminal domains of CEACAMs (40). The CEACAM binding site is located primarily in the A, B, E, and D strands of the Dr adhesin opposite the beta-sheet encompassing the previously determined binding site for DAF (40). Typical Afa/Dr DAEC strains have been described as invasive in unpolarized epithelial cells expressing several Afa/Dr fimbriae receptors but with a low level of efficiency (24, 26, 35). In cultured human polarized intestinal cells forming a cell monolayer that mimics an epithelium, these bacteria are apically uninvasive and enter the cells via the basolateral domain (26). The process of internalization into unpolarized epithelial cells involves lipid rafts (26, 37, 66) and dynamic, unstable microtubules (24, 26). Previous studies conducted with Dr and Afa-III fimbriae have not elucidated the processes by which typical Afa/Dr DAEC strains enter epithelial cells, which remain controversial. Two different working hypotheses have been proposed. According to one possible mechanism, after the Dr fimbriae have recognized the membrane-bound human DAF, the entire dra operon is necessary to trigger a receptor-mediated internalization of the bacteria (24). Selvarangan et al. (66) have shown that a transposon mutant with a mutation in the DraE adhesin subunit lacks adhesiveness and consequently fails to enter the cells. More convincingly, Das et al. (15) have demonstrated that the DraE subunit is both an adhesin and an invasin, since by mutagenesis to replace selected amino acids in hydrophilic domain II of the DraE protein, bacterial internalization was reduced or abolished without modifying the bacterial cell association. The second possible mechanism would imply that DraD and AfaD-III invasin subunits recognize the membrane-bound α5β1 integrin, and this is sufficient to trigger the entry of bacteria (26, 61) via a zipper-like mechanism (37). For this second mechanism, it has not been clearly established whether there is an initial step of recognition of the membrane-bound receptor DAF or CEACAM members by the AfaE/DraE adhesin subunits.We decided to conduct a series of experiments to analyze the role of DAF and/or α5β1 integrin in the receptor-mediated internalization of Afa/Dr DAEC. We extended our investigation by analyzing the role of the CEACAMs that act as receptors for Afa/Dr_CEACAM adhesins during the receptor-mediated internalization of Afa/Dr DAEC. We also investigated the role of AfaE/DraE adhesins and/or AfaD/DraD invasin subunits in bacterial internalization. We also examined the intracellular lifestyle of Dr fimbria-positive bacteria by comparing the survival rates of the intracellular bacteria in a series of cell lines, each of which expresses one of the membrane-bound epithelial receptors of Afa/Dr fimbriae, and by characterizing the late vacuole-containing internalized bacteria in a DAF-positive epithelial cell line.     

Conclusion about the association between valve surgery and mortality in an infective endocarditis cohort changed after adjusting for survivor bias

ObjectiveSurvivor bias commonly weakens observational studies, even those published in premier journals. It occurs because patients who live longer are more likely to receive treatment than those who die early. We sought to quantify the effect of survivor bias on the association between valve surgery and mortality in infective endocarditis (IE).Study Design and SettingThe study cohort included 546 IE patients. We compared the hazard ratios (HR) resulting from two propensity score analysis approaches that adjusted for survivor bias (time-dependent variable and matching on follow-up time) with those achieved using the same models but without that adjustment (time-fixed variable).ResultsIn the total cohort, the HR of surgery in the time-dependent model was 1.9 (95% confidence interval [CI] = 1.1–3.2; P = 0.03) vs. 0.9 (95% CI = 0.5–1.4; P = 0.53) in the time-fixed model. In the propensity score–matched subset, the HR of surgery was 1.3 (95% CI = 0.5–3.1; P = 0.56) and 0.8 (95% CI = 0.4–1.7; P = 0.57) in the subset with and without matching on follow-up time, respectively.ConclusionAdjusting for survivor bias changed the conclusion about the association between valve surgery and mortality in IE. Researchers should be aware of this bias when evaluating observational studies of treatment efficacy.     

Anophthalmia-plus syndrome: a clinical report and review of the literature

We describe a term male infant of healthy non-consanguineous parents, born with congenital malformations, including bilateral cleft palate and lip, mild microphthalmia with iris coloboma and glaucoma of the right eye, and blepharophimosis with severe microphthalmia of the left eye. Spine radiograph and MRI showed first sacral hemivertebra with spina bifida, and agenesis of the 2nd, 3rd, 4th, and 5th sacral vertebrae and coccyx. Spine MRI showed caudal tethering of spinal cord at L(3) level, filum terminalis lipoma and a syringomyelia. Brain ultrasound and MRI showed hypoplasia of corpus callosum with mild dilatation of the lateral ventricles. Orbital MRI showed bilateral microphthalmia-distorted small left eyeball with posteriorly located lens, and a split vitreous body in the right eye, suggestive of primary hyperplastic vitreous. The karyotype was normal. Summary of the findings in nine cases (our case and eight published cases) support the notion that anophthalmia-plus syndrome (APS) is a distinct syndrome. Gene locus of APS is yet to be identified.     

Rhino-orbitocerebral mucormycosis caused by Apophysomyces elegans

Rhino-orbitocerebral mucormycosis (ROCM) caused by more common zygomycetes (e.g., Mucor) is known to cause rapidly fatal infections in immunocompromised patients. Apophysomyces elegans is an emerging zygomycete that has been reported to cause invasive cutaneous and rhino-orbitocerebral infections in immunocompetent individuals. Limited data exist describing the syndrome of ROCM caused by A. elegans. We describe a recent case and performed a comprehensive literature review to delineate the clinical characteristics of ROCM caused by A. elegans. Our case is a 50-year-old man with diabetes mellitus who presented with facial pain and right eye proptosis. Endoscopic sinus sampling revealed A. elegans. He was treated with liposomal amphotericin B and multiple debridements, with no disease on 1.5-year follow-up examination. Seven cases were identified on literature review, including the present case. Most patients (86%) were male, with a mean age of 40 years. Most patients (71%) did not have predisposing medical conditions. Three patients had predisposing head trauma. All presented with facial and/or periorbital pain. All had magnetic resonance imaging or computed tomography of the head showing intraorbital and/or sinus inflammation. Diagnosis was confirmed by histopathology and deep tissue culture in all cases. All patients required eye exenteration and extensive surgical debridement, in addition to intravenous amphotericin B. Six of the seven patients (86%) recovered. ROCM caused by A. elegans is rarely reported in the literature. Most such infections occurred in immunocompetent patients, often after facial trauma. Survival in ROCM caused by A. elegans is favorable in reported cases, with prompt surgical debridement and antifungal therapy.     

Carcinosarcoma of the urinary bladder following cyclophosphamide therapy: evidence for monoclonal origin and chromosome 9p allelic loss

We report a case involving a 45-year-old man with a 12-year history of Wegener granulomatosis, who developed a carcinosarcoma of the urinary bladder after long-term cyclophosphamide therapy. Cyclophosphamide is well recognized as an etiologic agent for urothelial carcinoma of the urinary bladder. However, only 5 cases of carcinosarcoma of the urinary bladder following cyclophosphamide therapy have been reported. We used loss of heterozygosity studies and microsatellite markers to define the molecular basis of this rare neoplasm. These studies revealed evidence supporting a monoclonal origin for the 2 components of this tumor. We also demonstrated allelic loss of chromosome 9p. This loss associated with carcinosarcoma of the urinary bladder is in agreement with previous studies, suggesting a possible role for the tumor suppressor gene p16 in the pathogenesis of this tumor.     

In vivo and in vitro expression of connexin 43 in human teeth

Gap junctions are composed of transmembrane proteins belonging to the connexin family. These proteins permit the exchange of mall regulatory molecules directly between cells for the control of growth, development and differentiation. Although the presence of gap junctions in teeth has been already evidenced, the involved connexins have not yet been identified in human species. Here, we examined the distribution of connexin 43 (Cx43) in embryonic and permanent intact and carious human teeth. During tooth development, Cx43 localized both in epithelial and mesenchymal dental cells, correlated with cytodifferentiation gradients. In adult intact teeth, Cx43 was distributed in odontoblast processes. While Cx43 expression was downregulated in mature intact teeth, Cx43 appeared to be upregulated in odontoblasts facing carious lesions. In cultured pulp cells, Cx43 expression was related to the formation of mineralized nodules. These results indicate that Cx43 expression is developmentally regulated in human dental tissues, and suggest that Cx43 may participate in the processes of dentin formation and pathology.     

Translation, adaptation and validation of the Moroccan version of the Quebec Back Pain Disability Scale

This study aims to translate and cross-culturally adapt the Moroccan version of the Quebec Back Pain Disability Scale (QDS) and to investigate its reliability and validity in Moroccan patients with low back pain (LBP). The translation and cross-cultural adaptation of the QDS were developed in agreement with published guidelines. The QDS was translated by use of the forward and backward translation procedure. After pretest, it was validated in 64 Moroccan patients with LBP. The QDS was recorded twice, at baseline visit and 72?h later. Reproducibility was evaluated using intraclass correlation coefficient (ICC) and Bland and Altman method. Internal consistency was measured by Cronbach α coefficient. Ceiling and floor effects were assessed. Validity was measured by correlating the scores of the Moroccan QDS with visual analogue scale (VAS) for Pain, Disability VAS, Schober test, fingertip-floor measurement and the Moroccan version of the Roland Morris Disability Questionnaire (RMDQ) by means of the Spearman rank correlation coefficient. Association with gender and education level was also studied. Reliability was excellent with an ICC (type 2.1) of 0.959 (CI 95%: 0.934-0.975). The internal consistency was high with a Cronbach α of 0.979. The Bland and Altman method showed homogenous distribution of the differences, with no systematic trend. There were no floor or ceiling effects. The correlation between QDS and RMDQ was very good (r?=?0.664; p?≤?0.001). There was no correlation between QDS and the other variables. Accordingly, the Moroccan version of QDS has good reproducibility, internal consistency and validity for the assessment of disability in Moroccan-speaking patients with LBP.     

Telomere shortening and growth inhibition of human cancer cells by novel synthetic telomerase inhibitors MST-312, MST-295, and MST-1991

Epidemiological studies suggest potent anticancer effects of tea catechins. Previously, we have reported (I. Naasani et aL, Biochem. Biophys. Res. Commun., 249: 391-396, 1998) that epigallocatechin gallate (EGCG), a major tea catechin, strongly and directly inhibits telomerase, a ribonucleoprotein that maintains telomeres and has been implicated in tumorigenesis. Here, we describe newly synthesized compounds MST-312, MST-295, and MST-199, as more effective telomerase inhibitors than EGCG. Continuous treatment of human monoblastoid leukemia U937 cells with a nontoxic dose of each drug caused progressive telomere shortening and eventual reduction of growth rate accompanied by induction of the senescence-associated beta-galactosidase activity. Particularly, in the case of MST-312, the effective dose required for the telomere shortening was 1-2 microM, which was 15- to 20-fold lower than that of EGCG. These compounds may provide a novel chemotherapeutic strategy for the treatment of cancers.     

Long‐term clinical benefit of drug‐eluting stents over bare‐metal stents in diabetic patients with de novo left main coronary artery disease: Results from a real‐world multicenter registry

Background: Few data are available on diabetic patients undergoing percutaneous coronary intervention (PCI) in the context of unprotected left main coronary artery (ULMCA) disease. The main goal of this study was to present the long‐term relative benefits of using drug‐eluting stent (DES) instead of bare‐metal stent (BMS) for diabetic patients submitted to percutaneous ULMCA treatment in a large real world multicenter registry. Methods: The GISE‐SICI registry is a retrospective, observational multicenter registry promoted by the Italian Society of Invasive Cardiology in which 19 high‐volume participating centers enrolled 1,453 consecutive patients who underwent PCI on ULMCA between January 2002 and December 2006. From the registry, a total of 398 consecutive patients with diabetes mellitus who underwent DES (n = 321) or BMS (n = 77) implantation were analyzed, with extensive multivariable adjustments. Results: At 3‐years, use of DES in diabetic patients resulted in no significant differences with respect to death (HR 0.56, 95% CIs 0.24–1.28), myocardial infarction (HR 0.82, 95% CIs 0.21–3.26), and the composite end‐point of death or myocardial infarction (HR 0.56, 95% CIs 0.27–1.20). Conversely, DES were associated with significant reduction of target lesion revascularization (TLR, HR 0.33; 95% CIs 0.14–0.80, P = 0.001) rates. Conclusions: Patients presenting with ULMCA disease in the context of diabetes mellitus who are treated with stent‐supported PCI have a significant reduction in the rate of TLR with no increased risk of death or myocardial infarction. © 2009 Wiley‐Liss, Inc.