239 research outputs found

    Asymptomatic elevation of the hyperchromic red blood cell subpopulation is associated with decreased red cell deformability

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    Hyperchromasia of the red blood cells (RBC), defined as an elevation of the hyperchromic subpopulation, has been described for various medical conditions. However, neither the association of hyperchromasia with an altered RBC membrane nor with other medical conditions has been investigated in a systematic way so far. Since the percentage of hyperchromic RBC is measured on a routine basis by many hematologic laboratories, we evaluated the predictive value of this parameter for the detection of RBC disorders. An extensive workup of all patients undergoing standard hematogram during a period of 6months at our institution with a fraction of hyperchromic RBC larger than 10% was collected by reviewing the medical history and performing osmotic gradient ektacytometry on RBC from a part of these patients. Thirty-two thousand two hundred twenty-six individuals were screened; of which, 162 (0.5%) showed more than 10% hyperchromic RBC. All of the patients examined by ektacytometry featured abnormal membrane deformability. Hereditary spherocytosis was found in 19 out of these 32 patients, in most cases unknown to the patient and currently asymptomatic. Another 17.9% of the patients with an elevated subpopulation of hyperchromic RBC suffered from viral infection (human immunodeficiency virus, hepatitis). Our study shows that an elevated proportion of hyperchromic erythrocytes larger than 10% is associated with both hereditary and acquired RBC membrane disorders and further follow-up should be considere

    Predicting colorectal cancer risk from adenoma detection via a two-type branching process model.

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    Despite advances in the modeling and understanding of colorectal cancer development, the dynamics of the progression from benign adenomatous polyp to colorectal carcinoma are still not fully resolved. To take advantage of adenoma size and prevalence data in the National Endoscopic Database of the Clinical Outcomes Research Initiative (CORI) as well as colorectal cancer incidence and size data from the Surveillance Epidemiology and End Results (SEER) database, we construct a two-type branching process model with compartments representing adenoma and carcinoma cells. To perform parameter inference we present a new large-size approximation to the size distribution of the cancer compartment and validate our approach on simulated data. By fitting the model to the CORI and SEER data, we learn biologically relevant parameters, including the transition rate from adenoma to cancer. The inferred parameters allow us to predict the individualized risk of the presence of cancer cells for each screened patient. We provide a web application which allows the user to calculate these individual probabilities at https://ccrc-eth.shinyapps.io/CCRC/. For example, we find a 1 in 100 chance of cancer given the presence of an adenoma between 10 and 20mm size in an average risk patient at age 50. We show that our two-type branching process model recapitulates the early growth dynamics of colon adenomas and cancers and can recover epidemiological trends such as adenoma prevalence and cancer incidence while remaining mathematically and computationally tractable

    Hyperlipidemic myeloma: review of 53 cases

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    Hyperlipidemic myeloma is a rare and poorly understood variant of multiple myeloma. We report the case of a 53-year-old woman with hyperlipidemic myeloma, skin xanthomas and hyperviscosity syndrome who underwent allogeneic bone marrow transplantation. A comprehensive literature search identified 52 additional cases with plasma cell disease and hyperlipidemia. A detailed analysis revealed several characteristics of these patients as compared to multiple myeloma with normal lipid status: (1) IgA paraprotein was present in the majority (53% vs. 21% in classical multiple myeloma). (2) Skin xanthomas, especially in the palmar creases, elbows, and knees were common (70%). (3) Hyperviscosity syndrome occurred more often (26% vs. 2-6%). While conventional lipid-lowering therapy had only marginal effects, successful anti-myeloma therapy also reduced hyperlipidemia. Analyses of the mechanisms leading to hyperlipidemia documented complexes of paraprotein and lipoprotein in 75% of the 32 cases tested, suggesting an inhibitory role of the paraprotein on lipid degradation. In conclusion, the clinical characteristics, the therapeutic options, and the pathophysiologic mechanisms of hyperlipidemic myeloma are comprehensively reported using the available data from all 53 published cases in the literatur

    Benchmarking microbial DNA enrichment protocols from human intestinal biopsies.

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    Shotgun metagenomic sequencing is a powerful tool for studying bacterial communities in their natural habitats or sites of infection, without the need for cultivation. However, low microbial signals in metagenomic sequencing can be overwhelmed by host DNA contamination, resulting in decreased sensitivity for microbial read detection. Several commercial kits and other methods have been developed to enrich bacterial sequences; however, these assays have not been tested extensively for human intestinal tissues yet. Therefore, the objective of this study was to assess the effectiveness of various wet-lab and software-based approaches for depleting host DNA from microbiome samples. Four different microbiome DNA enrichment methods, namely the NEBNext Microbiome DNA Enrichment kit, Molzym Ultra-Deep Microbiome Prep, QIAamp DNA Microbiome kit, and Zymo HostZERO microbial DNA kit, were evaluated, along with a software-controlled adaptive sampling (AS) approach by Oxford Nanopore Technologies (ONT) providing microbial signal enrichment by aborting unwanted host DNA sequencing. The NEBNext and QIAamp kits proved to be effective in shotgun metagenomic sequencing studies, as they efficiently reduced host DNA contamination, resulting in 24% and 28% bacterial DNA sequences, respectively, compared to <1% in the AllPrep controls. Additional optimization steps using further detergents and bead-beating steps improved the efficacy of less efficient protocols but not of the QIAamp kit. In contrast, ONT AS increased the overall number of bacterial reads resulting in a better bacterial metagenomic assembly with more bacterial contigs with greater completeness compared to non-AS approaches. Additionally, AS also allowed for the recovery of antimicrobial resistance markers and the identification of plasmids, demonstrating the potential utility of AS for targeted sequencing of microbial signals in complex samples with high amounts of host DNA. However, ONT AS resulted in relevant shifts in the observed bacterial abundance, including 2 to 5 times more Escherichia coli reads. Furthermore, a modest enrichment of Bacteroides fragilis and Bacteroides thetaiotaomicron was also observed with AS. Overall, this study provides insight into the efficacy and limitations of various methods for reducing host DNA contamination in human intestinal samples to improve the utility of metagenomic sequencing

    Stability of gene rankings from RNAi screens

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    Motivation: Genome-wide RNA interference (RNAi) experiments are becoming a widely used approach for identifying intracellular molecular pathways of specific functions. However, detecting all relevant genes involved in a biological process is challenging, because typically only few samples per gene knock-down are available and readouts tend to be very noisy. We investigate the reliability of top scoring hit lists obtained from RNAi screens, compare the performance of different ranking methods, and propose a new ranking method to improve the reproducibility of gene selection. Results: The performance of different ranking methods is assessed by the size of the stable sets they produce, i.e. the subsets of genes which are estimated to be re-selected with high probability in independent validation experiments. Using stability selection, we also define a new ranking method, called stability ranking, to improve the stability of any given base ranking method. Ranking methods based on mean, median, t-test and rank-sum test, and their stability-augmented counterparts are compared in simulation studies and on three microscopy image RNAi datasets. We find that the rank-sum test offers the most favorable trade-off between ranking stability and accuracy and that stability ranking improves the reproducibility of all and the accuracy of several ranking methods. Availability: Stability ranking is freely available as the R/Bioconductor package staRank at http://www.cbg.ethz.ch/software/staRank. Contact: [email protected] Supplementary information: Supplementary data are available at Bioinformatics onlin

    Challenges in the diagnosis of marginal zone lymphoma with symptoms of small intestinal disease: a case report and scoping review of the literature.

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    Background Marginal zone lymphoma can be accompanied by symptoms of small intestinal disease including abdominal pain and malabsorption. However, the best diagnostic approach for suspected marginal zone lymphoma is unknown and intestinal biopsies are frequently negative. We describe the case of a patient with symptoms of small bowel involvement where marginal zone lymphoma could only be detected upon peripheral lymph node resection. To assess the clinical variability of intestinal marginal zone lymphoma as a rare clinical entity, a scoping review with systematic literature research was performed. Methods A 57-year-old man presented with a 10-year history of postprandial abdominal pain, systemic inflammation and recent weight loss. Endoscopies and a surgical small bowel specimen revealed non-specific findings. Flow cytometry from the bone marrow was highly suspicious for marginal zone lymphoma. A 2-18F-fluorodeoxyglucose-positron emission tomography/computed tomography (2-18F-FDG-PET/CT) showed hypermetabolic lymph nodes on both sides of the diaphragm. Cervical lymph node dissection finally confirmed marginal zone lymphoma. Immunochemotherapy yielded lasting oncological remission and resolved symptoms. We searched PubMed, Embase and Ovid MEDLINE® for additional case reports limited to the last 25 years. Five primary search terms combined using "AND" were used freely and as controlled vocabulary. Additional studies were identified by reviewing the reference lists of included articles. Results Our review revealed 52 cases of marginal zone lymphoma with small intestinal manifestation. Patients presented with abdominal pain, bowel obstruction, weight loss or gastrointestinal bleeding. Diagnosis was mainly established by surgery (73%). The most frequent endoscopic findings were mucosal erosions and ulcerations. A 2-18F-FDG-PET/CT was positive in 9/15 patients. Treatment included rituximab, chemotherapy, surgery and/or radiation resulting in clinical remission in 82% of cases. Conclusions Diagnostic workup for suspected small intestinal marginal zone lymphoma is challenging, necessitating a multidisciplinary approach. Endoscopy, imaging including 2-18F-FDG-PET/CT and small bowel resection or dissection of hypermetabolic lymph nodes can be useful. If marginal zone lymphoma is suspected vigorous diagnostic efforts are justified since remission can be achieved in most patients. Our review highlights the variable clinical presentation of this underdiagnosed disease and adds systematic data to the literature

    Necrobiotic xanthogranuloma successfully treated with autologous stem cell transplantation

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    Paraproteinemia can be complicated by necrobiotic xanthogranuloma. Therapeutic options for this progressive disease are limited, and there is no agreement on a single best strategy. We report the case of a patient with a massive periorbital infiltration narrowing the palpebral fissure and blinding the patient. Conventional myeloma therapy had only limited benefit in our patient. However, he was successfully treated with high-dose chemotherapy followed by autologous stem cell transplantation, rendering the patient free of symptoms. This is the first report of autologous stem cell transplantation in a patient with necrobiotic xanthogranulom

    Morbus Crohn: zeitgemässe Therapie von perianalen Fisteln

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    Perianale Fisteln beeinträchtigen die Lebensqualität von Patienten mit Morbus Crohn stark. Wenngleich in den letzten Jahren deutliche Fortschritte in der Effizienz der medikamentösen und chirurgischen Therapieverfahren erzielt werden konnten, sind die Ansprechraten nach wie vor suboptimal und Rezidive des Fistelleidenshäufig. Ein Therapieerfolg ist in den meisten Fällen möglich, verlangt jedoch eine gute Zusammenarbeit von Chirurgen und Gastroenterologen
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