Identification of Medically Relevant Species of Arthroconidial Yeasts by Use of Matrix-Assisted Laser Desorption Ionization–Time of Flight Mass Spectrometry

Matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS) was used for an extensive identification study of arthroconidial yeasts, using 85 reference strains from the CBS-KNAW yeast collection and 134 clinical isolates collected from medical centers in Qatar, Greece, and Romania. The test set included 72 strains of ascomycetous yeasts (Galactomyces, Geotrichum, Saprochaete, and Magnusiomyces spp.) and 147 strains of basidiomycetous yeasts (Trichosporon and Guehomyces spp.). With minimal preparation time, MALDI-TOF MS proved to be an excellent diagnostic tool that provided reliable identification of most (98%) of the tested strains to the species level, with good discriminatory power. The majority of strains were correctly identified at the species level with good scores (>2.0) and seven of the tested strains with log score values between 1.7 and 2.0. The MALDI-TOF MS results obtained were consistent with validated internal transcribed spacer (ITS) and/or large subunit (LSU) ribosomal DNA sequencing results. Expanding the mass spectrum database by increasing the number of reference strains for closely related species, including those of nonclinical origin, should enhance the usefulness of MALDI-TOF MS-based diagnostic analysis of these arthroconidial fungi in medical and other laboratories.     

Impact of IL12B Gene rs 3212227 Polymorphism on Fibrosis,Liver Inflammation,and Response to Treatment in Genotype 4 Egyptian Hepatitis C Patients

Introduction. Hepatitis C virus (HCV) infection affects almost 3% of the world''s population with the highest prevalence in Egypt (15%). The standard therapy; pegylated interferon (PEG-IFN) and ribavirin, is effective in only 60% of Egyptian patients; moreover it is costly, prolonged, and has severe side effects, so prediction of response is essential to reduce burden of unfavorable treatment. Several viral and host factors have been proved to affect response to the treatment PEG-IFN and ribavirin; the strongest of them is polymorphisms near IL28B; nonetheless, nonresponse in patients with favorable IL28B is still unexplained, which implies the importance of studying other immunological factors that may correlate with response. Interleukin 12 (IL-12) is one of the most important proinflammatory cytokine presented with the initiation of immune response, determining Th1 and Th2 differentiation. A functional single nucleotide polymorphism (A/C) at the 3′ untranslated region (3′UTR) at position 1188 (NCBI SNP database no 3212227) was reported to be associated with responding more efficiently to antiviral combination therapy in HCV genotype 1 infected patients. The present study aims to evaluate association between this polymorphism with fibrosis stages, necroinflammation activity, response to the combined therapy, and gender in Egyptian HCV genotype 4. Material and Methods. A total of 133 Egyptian chronic HCV (CHCV) patients were treated with IFN/RBV and were followed up. IL12B 1188 A/C genotyping was performed using polymerase chain reaction-restriction fragment length polymorphism (PRC-RFLP) analysis. Results. A nonsignificant trend for higher sustained virological response (SVR) was observed in patients homozygote for IL12B 1188 A/C SNP CC genotype (69% SVR versus 30.8% NR) only but not in AC and AA genotypes. No association was detected between IL12B 1188 A/C polymorphism and less severe fibrosis or less liver activity. By stratification of response according to gender genotype, a significant difference in response between males and females was seen among AA genotype carriers only due to high number of non responder females. Conclusion. IL12B CC genotype appears to have some influence on SVR achievement but not on severe fibrosis and severe necroinflamation activity. Females carrying A/A genotype of IL12B 1188 A/C SNP achieve less SVR than those carrying AC and CC genotypes.     

ABO blood group in Amerindians from Brazilian Amazon

Background : The Parakanã is a group of Indians with cultural similarities to the extinct Tupi group. They are an isolated native population from East Brazilian Amazon. A number of different O alleles have been found at the blood group ABO locus in populations of several ethnic origins (Caucasians, Blacks, Amerindians). Aim : The present study describes the ABO blood group polymorphism gene of the Parakanã Indians. The Amerindian group was carefully selected for racial background. Subject and methods : The blood group polymorphism was analysed in genomic DNA from 62 Parakanã Indians. We determined the 261G deletion, the T646A and C771T mutations described in O 1variant and the G542A substitution, using PCR-RFLP (polymerase chain reaction-restriction fragment length polymorphism). Results : All Amerindians studied were homozygous for the 261G deletion. The frequencies of the T646A and C771T mutations in Parakanãs (0.65) were lower than that observed in Kayapo, Yanomama and Arara Indians (0.91) ( &#104 2 = 18.24; p-v < 0.001. The G542A substitution in Parakanãs was also lower (0.22) than in other tribes (0.42) ( &#104 2 = 9.73; p-v = 0.001). Conclusions : The different O alleles including the G542A mutation are not distributed homogeneously among all Amazonian Amerindians. Our results are in agreement with other genetic markers studied previously in Parakanã Indians, whose distinct genetic pattern differs from Europeans and even from other Amerindians.     

Myeloid-derived suppressor cells and regulatory T cells share common immunoregulatory pathways-related microRNAs that are dysregulated by acute lymphoblastic leukemia and chemotherapy

BackgroundRelapse remains a critical challenge in children with acute lymphoblastic leukemia (ALL). The emergence of immunoregulatory cells, including myeloid-derived suppressor cells (MDSCs), and T regulatory (T_reg) cells, has been considered one potential mechanism of relapse in children with ALL.AimThis study aimed to address the microRNAs (miRNAs) related to MDSCs and T_reg cells and to explore their targeted immunoregulatory pathways.MethodsAffymetrix microarray was used for global miRNA profiling in B-ALL pediatric patients before, during, and after induction of chemotherapy. Bioinformatics analysis was performed on MDSCs and T_reg cells-related dysregulated miRNAs, and miR-Pathway analysis was performed to explore their targeted immunoregulatory pathways.Results516 miRNAs were dysregulated in ALL patients as compared to the healthy donor. Among them, 13 miRNAs and 8 miRNAs related to MDSCs and T_reg cells, respectively, were common in all patients. Besides, 12 miRNAs were shared between MDSCs and T_reg cells; 4 of them were common in all patients. Four immune-related pathways; TNF, TGF-β, FoxO, and Hippo were found implicated.ConclusionOur pilot study concluded certain miRNAs related to MDSCs and T_reg cells, these miRNAs were linked to immunoregulatory pathways. Our results open avenues for testing those miRNA as molecular biomarkers for the immunosuppressive tumor microenvironment.     

Diagnostic Performance of 68Ga-DOTATATE PET/CT, 18F-FDG PET/CT and 131I-MIBG Scintigraphy in Mapping Metastatic Pheochromocytoma and Paraganglioma

Purpose

To evaluate the diagnostic performance of ⁶⁸Ga-DOTATATE ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography (PET)/computed tomography (CT), ¹⁸F-FDG PET/CT and ¹³¹I-MIBG scintigraphy in the mapping of metastatic pheochromocytoma and paraganglioma.

Materials and Methods

Seventeen patients (male = 8, female = 9; age range, 13–68 years) with clinically proven or suspicious metastatic pheochromocytoma or paraganglioma were included in this prospective study. Twelve patients underwent all three modalities, whereas five patients underwent ⁶⁸Ga-DOTATATE and ¹³¹I-MIBG without ¹⁸F-FDG. A composite reference standard derived from anatomical and functional imaging findings, along with histopathological information, was used to validate the findings. Results were analysed on a per-patient and on per-lesion basis. Sensitivity and accuracy were assessed using McNemar’s test.

Results

On a per-patient basis, 14/17 patients were detected in ⁶⁸Ga-DOTATATE, 7/17 patients in ¹³¹I-MIBG, and 10/12 patients in ¹⁸F-FDG. The sensitivity and accuracy of ⁶⁸Ga-DOTATATE, ¹³¹I-MIBG and ¹⁸F-FDG were (93.3 %, 94.1 %), (46.7 %, 52.9 %) and (90.9 %, 91.7 %) respectively. On a per-lesion basis, an overall of 472 positive lesions were detected; of which 432/472 were identified by ⁶⁸Ga-DOTATATE, 74/472 by ¹³¹I-MIBG, and 154/300 (patient, n = 12) by ¹⁸F-FDG. The sensitivity and accuracy of ⁶⁸Ga-DOTATATE, ¹³¹I-MIBG and ¹⁸F-FDG were (91.5 %, 92.6 % p < 0.0001), (15.7 %, 26.0 % p < 0.0001) and (51.3 %, 57.8 % p < 0.0001) respectively. Discordant lesions were demonstrated on ⁶⁸Ga-DOTATATE, ¹³¹I-MIBG and ¹⁸F-FDG.

Conclusions

Ga-DOTATATE PET/CT shows high diagnostic accuracy than ¹³¹I-MIBG scintigraphy and ¹⁸F-FDG PET/ CT in mapping metastatic pheochromocytoma and paraganglioma.     

Liver-derived fetal hematopoietic stem cells selectively and preferentially home to the fetal bone marrow

In the course of ontogeny, the homing site for the hematopoietic stem cells (HSC) moves with certain predictability from the yolk sac to the liver/spleen and then to the marrow. The pattern of this migration has thus far been established mostly on a morphologic basis. To delineate further the course of this migration and to gain insight into its possible mechanism, we used in utero transplantation of allogeneic or xenogeneic HSC in preimmune sheep fetuses. Sex chromosome, type of hemoglobin, and species-specific surface markers were used to follow the path of transplanted cells in the fetus. Before the development of the bone marrow, transplanted HSC (liver- or marrow-derived) homed exclusively to the liver/spleen. With the development of marrow, around day 60 of gestation (term, 145 days), homing occurred also in the nascent marrow and by day 80 transplanted cells homed exclusively to the marrow. This suggests that there may be a hierarchy in homing sites, with those of the marrow having higher affinity than those of liver/spleen. Interestingly, despite a change in homing that was followed by the expansion of the marrow compartment of HSC (ie, HSC proliferation), these cells did not participate actively in blood cell formation during most of the prenatal period. Liver remained the major hematopoietic organ throughout the gestation. It was only during the perinatal period that this organ assumed the function of hematopoiesis from the liver. This lack of expression of HSC in fetal marrow can possibly be attributable to the immaturity of marrow stroma required for differentiation and maturation of progenitors and the orderly egress of mature cells into the blood stream. The availability of this model allows us to begin studies in the molecular mechanism of stem cell homing in vivo during ontogeny.     

Colorectal liver metastases: disappearing lesions in the era of Eovist hepatobiliary magnetic resonance imaging

Background

Hepatobiliary contrast enhanced MRI is known to be the most sensitive imaging modality for detection of colorectal hepatic metastasis. To date no study has investigated the rate of disappearing lesions with gadoxetic acid MR (Eovist/Primovist), or characterized the pathologic response of lesions which disappear on gadoxetic acid MR.

Methods

Retrospective review of hepatic resections for colorectal metastases between 01/2008 and 01/2014 was performed to evaluated the rate of disappearance of lesions on gadoxetic acid MR and the rate of complete pathologic response in the lesions that disappear. “Disappearing lesions” were lesions on baseline imaging that were not identifiable on pre-operative Eovist MRI. Complete pathologic response was defined as no viable tumor on pathology or by lack of recurrence within 1 year.

Results

In 23 patients, 200 colorectal metastases were identified on baseline imaging. On pre-operative Eovist MR 77 of the 200 lesions (38.5%) were “disappearing” lesions. At surgical pathology or 1 year follow-up imaging, 42 of 77 lesions (55%) demonstrated viable tumor (21) or recurrence (21). Thirty of 77 lesions (39%) were nonviable at pathology (10) or without evidence of recurrence at 1 year (20). 5 lesions were indeterminate.

Discussion

Despite disappearance on Eovist MR imaging (the most sensitive available imaging modality), 38.5% of all colorectal metastases disappeared and of those, 55% were viable.     

Prevalence and outcome of severe chronic obstructive pulmonary disease exacerbations caused by multidrug-resistant bacteria

PURPOSE OF REVIEW: A bacterial cause is found in about half of all severe chronic obstructive pulmonary disease exacerbations. The aim of this review is to discuss recent findings regarding prevalence, risk factors and outcome of severe chronic obstructive pulmonary disease exacerbations caused by multidrug-resistant bacteria. RECENT FINDINGS: According to the results of recent studies, multidrug-resistant bacteria represented a large proportion of bacteria isolated in chronic obstructive pulmonary disease exacerbations. Prior antibiotic treatment, prior endotracheal intubation, long-term inhaled or systemic corticosteroid use and severe impairment of lung function were identified as risk factors for severe chronic obstructive pulmonary disease exacerbations related to multidrug-resistant bacteria. Although the mortality rate was higher in patients with multidrug-resistant bacteria as compared with patients with other bacteria, multidrug resistance was not independently associated with mortality in these patients. Multidrug-resistant bacteria were, however, significantly associated with inappropriate initial antibiotic treatment. Higher rates of subsequent ventilator-associated pneumonia and mortality were found in patients with severe chronic obstructive pulmonary disease exacerbation who received inappropriate initial antibiotic treatment when compared with those who received appropriate treatment. SUMMARY: Further studies should determine whether administration of broad-spectrum antibiotic treatment could improve the outcome of patients with severe chronic obstructive pulmonary disease exacerbation caused by multidrug-resistant bacteria.