Single-cell copy number variation detection

Detection of chromosomal aberrations from a single cell by array comparative genomic hybridization (single-cell array CGH), instead of from a population of cells, is an emerging technique. However, such detection is challenging because of the genome artifacts and the DNA amplification process inherent to the single cell approach. Current normalization algorithms result in inaccurate aberration detection for single-cell data. We propose a normalization method based on channel, genome composition and recurrent genome artifact corrections. We demonstrate that the proposed channel clone normalization significantly improves the copy number variation detection in both simulated and real single-cell array CGH data

Antireflux surgery and risk of esophageal adenocarcinoma : a systematic review and meta-analysis

Objective: To investigate the preventive effect of antireflux surgery against esophageal adenocarcinoma (EAC), compared to medical treatment of gastroesophageal reflux disease (GERD) and to the background population. Background: GERD is causally associated with EAC. Effective symptomatic treatment can be achieved with medication and antireflux surgery, yet the possible preventive effect on EAC development remains unclear. Methods: This systematic review identified 10 studies comparing EAC risk following antireflux surgery with non-operated GERD patients, including 7 studies of patients with Barrett’s esophagus; and 2 studies comparing EAC risk after antireflux surgery to the background population. A fixed-effects Poisson meta-analysis was conducted to calculate pooled incidence rate ratios (IRR) and 95% confidence intervals (CI). Results: The pooled IRR in patients following antireflux surgery was 0.76 (95% CI 0.42-1.39) compared to medically treated GERD patients. In patients with Barrett’s esophagus, the corresponding IRR was 0.46 (95% CI 0.20-1.08), and 0.26 (95% CI 0.09-0.79) when restricted to publications after 2000. There was no difference in EAC risk between antireflux surgery and medical treatment in GERD patients without known Barrett’s esophagus (IRR 0.98, 95% CI 0.72-1.33). The EAC risk remained elevated in patients following antireflux surgery compared to the background population (IRR 10.78, 95% CI 8.48-13.71). While the clinical heterogeneity of the included studies was high, the statistical heterogeneity was low. Conclusions: Antireflux surgery may prevent EAC better than medical therapy in patients with Barrett’s esophagus. The EAC risk following antireflux surgery does not seem to revert to that of the background population.The Swedish Research Council, the Swedish Cancer Society, the Julin Foundation at the Karolinska Institutet, and the Swedish Society of MedicinePublishe

Mortality from laparoscopic antireflux surgery in a nationwide cohort of the working-age population

VetenskapsrådetPublishe

Reversed polarized delivery of an aquaporin-2 mutant causes dominant nephrogenic diabetes insipidus

Vasopressin regulates body water conservation by redistributing aquaporin-2 (AQP2) water channels from intracellular vesicles to the apical surface of renal collecting ducts, resulting in water reabsorption from urine. Mutations in AQP2 cause autosomal nephrogenic diabetes insipidus (NDI), a disease characterized by the inability to concentrate urine. Here, we report a frame-shift mutation in AQP2 causing dominant NDI. This AQP2 mutant is a functional water channel when expressed in Xenopus oocytes. However, expressed in polarized renal cells, it is misrouted to the basolateral instead of apical plasma membrane. Additionally, this mutant forms heterotetramers with wild-type AQP2 and redirects this complex to the basolateral surface. The frame shift induces a change in the COOH terminus of AQP2, creating both a leucine- and a tyrosine-based motif, which cause the reversed sorting of AQP2. Our data reveal a novel cellular phenotype in dominant NDI and show that dominance of basolateral sorting motifs in a mutant subunit can be the molecular basis for disease

Menopausal hormone therapy and the risk of esophageal and gastric cancer

A protective effect of female sex hormones has been suggested to explain the male predominance in esophageal and gastric adenocarcinoma, but evidence is lacking. We aimed to test whether menopausal hormone therapy (MHT) decreases the risk of these tumors. For comparison, esophageal squamous cell carcinoma was also assessed. This population-based matched cohort study included all women who had ever used systemic MHT in Sweden in 2005-2012. A comparison cohort of non-users of MHT was matched to the MHT-users regarding age, parity, thrombotic events, hysterectomy, diabetes, obesity, smoking-related diseases, and alcohol-related diseases. Individuals with any previous cancer were excluded. Data on MHT use, cancer, comorbidity, and mortality were collected from well-established Swedish nationwide registers. Odds ratios (OR) with 95% confidence intervals (CI) were calculated using conditional logistic regression. Different MHT regimens and age groups were compared in sub-group analyses. We identified 290,186 ever-users and 870,165 non-users of MHT. Ever-users had decreased ORs of esophageal adenocarcinoma (OR=0.62, 95% CI 0.45-0.85, n=46), gastric adenocarcinoma (OR=0.61, 95% CI 0.50-0.74, n=123), and esophageal squamous cell carcinoma (OR=0.57, 95% CI 0.39-0.83, n=33). The ORs were decreased for both estrogen-only MHT and estrogen and progestin combined MHT, and in all age groups. The lowest OR was found for esophageal adenocarcinoma in MHT-users younger than 60 years (OR=0.20, 95% CI 0.06-0.65). Our study suggests that MHT-users are at a decreased risk of esophageal and gastric adenocarcinoma, and also of esophageal squamous cell carcinoma. The mechanisms behind these associations remain to be elucidated.The Swedish Research CouncilAccepte