Project description:Bacteria-host interactions are dynamic processes, and understanding transcriptional responses that directly or indirectly regulate the expression of genes involved in initial infection stages would illuminate the molecular events that result in host colonization. We used oligonucleotide microarrays to monitor (in vitro) differential gene expression in group A streptococci during pharyngeal cell adherence, the first overt infection stage. We present neighbor clustering, a new computational method for further analyzing bacterial microarray data that combines two informative characteristics of bacterial genes that share common function or regulation: (1) similar gene expression profiles (i.e., co-expression); and (2) physical proximity of genes on the chromosome. This method identifies statistically significant clusters of co-expressed gene neighbors that potentially share common function or regulation by coupling statistically analyzed gene expression profiles with the chromosomal position of genes. We applied this method to our own data and to those of others, and we show that it identified a greater number of differentially expressed genes, facilitating the reconstruction of more multimeric proteins and complete metabolic pathways than would have been possible without its application. We assessed the biological significance of two identified genes by assaying deletion mutants for adherence in vitro and show that neighbor clustering indeed provides biologically relevant data. Neighbor clustering provides a more comprehensive view of the molecular responses of streptococci during pharyngeal cell adherence.
Project description:The discovery of genetic mutations in children with inherited syndromes of intrahepatic cholestasis allows for diagnostic specificity despite similar clinical phenotypes. Here, we aimed to determine whether mutation screening of target genes could assign a molecular diagnosis in children with idiopathic cholestasis.DNA samples were obtained from 51 subjects with cholestasis of undefined etiology and surveyed for mutations in the genes SERPINA1, JAG1, ATP8B1, ABCB11, and ABCB4 by a high-throughput gene chip. Then, the sequence readouts for all 5 genes were analyzed for mutations and correlated with clinical phenotypes. Healthy subjects served as controls.Sequence analysis of the genes identified 14 (or 27%) subjects with missense, nonsense, deletion, and splice site variants associated with disease phenotypes based on the type of mutation and/or biallelic involvement in the JAG1, ATP8B1, ABCB11, or ABCB4 genes. These patients had no syndromic features and could not be differentiated by biochemical markers or histopathology. Among the remaining subjects, 10 (or ?20%) had sequence variants in ATP8B1 or ABCB11 that involved only 1 allele, 8 had variants not likely to be associated with disease phenotypes, and 19 had no variants that changed amino acid composition.Gene sequence analysis assigned a molecular diagnosis in 27% of subjects with idiopathic cholestasis based on the presence of variants likely to cause disease phenotypes.
Project description:Recent studies support the existence of oogonial stem cells (OSCs) in the ovarian cortex of different mammals, including women.These cells are characterized by small size, membrane expression of DEAD(Asp-Glu-Ala-Asp)-box polypeptide-4 (Ddx4), and stemness properties (such as self-renewal and clonal expansion) as well as the ability to differentiate in vitro into oocyte-like cells. However, the discovery of OSCs contrasts with the popular theory that there is a numerically defined oocyte pool for female fertility which undergoes exhaustion with menopause. Indeed, in the ovarian cortex of postmenopausal women OSCs have been detected that possess both viability and capability to differentiate into oocytes, which is similar to those observed in younger patients. The pathophysiological role of this cell population in aged women is still debated since OSCs, under appropriate stimuli, differentiate into somatic cells, and the occurrence of Ddx4+ cells in ovarian tumor samples also suggests their potential involvement in carcinogenesis. Although further investigation into these observations is needed to clarify OSC function in ovary physiology, clinical investigators and researchers studying female infertility are presently focusing on OSCs as a novel opportunity to restore ovarian reserve in both young women undergoing early ovarian failure and cancer survivors experiencing iatrogenic menopause.
Project description:Smooth muscle neoplasms with atypical proliferative behaviour, but without clear histopathological malignancy represent a diagnostic and therapeutic challenge, as distinction from a sarcoma can be difficult and no guaranteed treatment recommendations are available due to the rarity of these changes. In the event of uncertain primary histology, even metastases cannot be assessed as malignancy criteria, but may contribute to the clarification of the histology. Similarities with other smooth muscle proliferations, such as lymphangioleiomyomatosis, are striking. The diagnostic difficulties and treatment options are explained based on the example of a 59-year-old patient, in whom a retroperitoneal mass and pulmonary lesion of such a tumour occurred 4 years after a hysterectomy. Even though the genesis and histological diagnostics have not been conclusively clarified, slow growth and a low recurrence rate for post-menopausal patients allow for a wait-and-see approach, whereby the option for anti-hormonal treatment exists in the event of positive evidence of hormone receptors.
Project description:Autoimmune lymphoproliferative syndrome (ALPS) is characterized by childhood onset of lymphadenopathy, hepatosplenomegaly, autoimmune cytopenias, elevated numbers of double-negative T (DNT) cells, and increased risk of lymphoma. Most cases of ALPS are associated with germline mutations of the FAS gene (type Ia), whereas some cases have been noted to have a somatic mutation of FAS primarily in their DNT cells. We sought to determine the proportion of patients with somatic FAS mutations among a group of our ALPS patients with no detectable germline mutation and to further characterize them. We found more than one-third (12 of 31) of the patients tested had somatic FAS mutations, primarily involving the intracellular domain of FAS resulting in loss of normal FAS signaling. Similar to ALPS type Ia patients, the somatic ALPS patients had increased DNT cell numbers and elevated levels of serum vitamin B(12), interleukin-10, and sFAS-L. These data support testing for somatic FAS mutations in DNT cells from ALPS patients with no detectable germline mutation and a similar clinical and laboratory phenotype to that of ALPS type Ia. These findings also highlight the potential role for somatic mutations in the pathogenesis of nonmalignant and/or autoimmune hematologic conditions in adults and children.
Project description:BackgroundGranulomatous disease is reported in at least 8-20% of patients with common variable immunodeficiency (CVID). Granulomatous disease mainly affects the lungs, and is associated with significantly higher morbidity and mortality. In half of patients with granulomatous disease, extrapulmonary manifestations are found, affecting e.g. skin, liver, and lymph nodes. In literature various therapies have been reported, with varying effects on remission of granulomas and related clinical symptoms. However, consensus recommendations for optimal management of extrapulmonary granulomatous disease are lacking.ObjectiveTo present a literature overview of the efficacy of currently described therapies for extrapulmonary granulomatous disease in CVID (CVID+EGD), compared to known treatment regimens for pulmonary granulomatous disease in CVID (CVID+PGD).MethodsThe following databases were searched: Embase, Medline (Ovid), Web-of-Science Core Collection, Cochrane Central, and Google Scholar. Inclusion criteria were 1) CVID patients with granulomatous disease, 2) treatment for granulomatous disease reported, and 3) outcome of treatment reported. Patient characteristics, localization of granuloma, treatment, and association with remission of granulomatous disease were extracted from articles.ResultsWe identified 64 articles presenting 95 CVID patients with granulomatous disease, wherein 117 different treatment courses were described. Steroid monotherapy was most frequently described in CVID+EGD (21 out of 53 treatment courses) and resulted in remission in 85.7% of cases. In CVID+PGD steroid monotherapy was described in 15 out of 64 treatment courses, and was associated with remission in 66.7% of cases. Infliximab was reported in CVID+EGD in six out of 53 treatment courses and was mostly used in granulomatous disease affecting the skin (four out of six cases). All patients (n = 9) treated with anti-TNF-α therapies (infliximab and etanercept) showed remission of extrapulmonary granulomatous disease. Rituximab with or without azathioprine was rarely used for CVID+EGD, but frequently used in CVID+PGD where it was associated with remission of granulomatous disease in 94.4% (17 of 18 treatment courses).ConclusionAlthough the number of CVID+EGD patients was limited, data indicate that steroid monotherapy often results in remission, and that anti-TNF-α treatment is effective for granulomatous disease affecting the skin. Also, rituximab with or without azathioprine was mainly described in CVID+PGD, and only in few cases of CVID+EGD.
Project description:Although family history is a major risk factor for colorectal cancer (CRC) a genetic diagnosis cannot be obtained in over 50 % of familial cases when screened for known CRC cancer susceptibility genes. The genetics of undefined-familial CRC is complex and recent studies have implied additional clinically actionable mutations for CRC in susceptibility genes for other cancers. To clarify the contribution of non-CRC susceptibility genes to undefined-familial CRC we conducted a mutational screen of 114 cancer susceptibility genes in 847 patients with early-onset undefined-familial CRC and 1609 controls by analysing high-coverage exome sequencing data. We implemented American College of Medical Genetics and Genomics standards and guidelines for assigning pathogenicity to variants. Globally across all 114 cancer susceptibility genes no statistically significant enrichment of likely pathogenic variants was shown (6.7 % cases 57/847, 5.3 % controls 85/1609; P = 0.15). Moreover there was no significant enrichment of mutations in genes such as TP53 or BRCA2 which have been proposed for clinical testing in CRC. In conclusion, while we identified genes that may be considered interesting candidates as determinants of CRC risk warranting further research, there is currently scant evidence to support a role for genes other than those responsible for established CRC syndromes in the clinical management of familial CRC.