Investigation of the phase transitions occurring during and after the dehydration of xylazine hydrochloride monohydrate

This paper reports an investigation of a complex solid state phase transition where two inter-converting polymorphs (X and A) of the pharmaceutical molecule xylazine hydrochloride formed and transformed during and after the dehydration of its monohydrate (H). The crystal structures of all three forms were compared. During the investigation of this solid state phase transition it was determined that the dehydration of H produced either a pure X form, or a mixture of the X and A forms. The phase composition depended on the sample preparation procedure and the experimental conditions. It was found that grinding of the hydrate enhanced the formation of polymorph X as a product of dehydration, whereas higher humidity, temperature, or mechanical compression enhanced the formation of polymorph A. The transition mechanism of this complex process was analysed and explained by taking into account the crystal structures of these three forms.     

Large genomic deletions: a novel cause of Ullrich congenital muscular dystrophy

Two mutational mechanisms are known to underlie Ullrich congenital muscular dystrophy (UCMD): heterozygous dominant negatively-acting mutations and recessively-acting loss-of-function mutations. We describe large genomic deletions on chromosome 21q22.3 as a novel type of mutation underlying recessively inherited UCMD in 2 families. Clinically unaffected parents carrying large genomic deletions of COL6A1and COL6A2also provide conclusive evidence that haploinsufficiency for COL6A1and COL6A2is not a disease mechanism for Bethlem myopathy. Our findings have important implications for the genetic evaluation of patients with collagen VI-related myopathies as well as for potential therapeutic interventions for this patient population.     

Tumor‐associated autoantibody signature for the early detection of gastric cancer

Autoantibodies against tumor‐associated antigens are very attractive biomarkers for the development of noninvasive serological tests for the early detection of cancer because of their specificity and stability in the sera. In our study, we applied T7 phage display‐based serological analysis of recombinant cDNA expression libraries technique to identify a representative set of antigens eliciting humoral responses in patients with gastric cancer (GC), produced phage–antigen microarrays and exploited them for the survey of autoantibody repertoire in patients with GC and inflammatory diseases. We developed procedures for data normalization and cutoff determination to define sero‐positive signals and ranked them by the signal intensity and frequency of reactivity. To identify autoantibodies with the highest diagnostic value, a 1,150‐feature microarray was tested with sera from 100 patients with GC and 100 cancer‐free controls, and then the top‐ranked 86 antigens were used for the production of focused array that was tested with an independent validation set comprising serum samples from 235 patients with GC, 154 patients with peptic ulcer and gastritis and 213 healthy controls. The receiver operating characteristic curve analysis showed that 45‐autoantibody signature could discriminate GC and healthy controls with area under the curve (AUC) of 0.79 (59% sensitivity and 90% specificity), GC and peptic ulcer with AUC of 0.76 and GC and gastritis with AUC of 0.64. Moreover, it could detect early GC with equal sensitivity than advanced GC. Interestingly, the autoantibody production did not correlate with histological type, H. pylori status, grade, localization and size of the primary tumor, whereas it appeared to be associated with the metastatic disease.     

Pancreatic calcifications associate with diverse aetiological risk factors in patients with chronic pancreatitis: A multicentre study of 1500 cases

BackgroundPancreatic calcifications is a common finding in patients with chronic pancreatitis (CP), but the underlying pathophysiology is incompletely understood. Past studies for risk factors of calcifications have generally been focused on single parameters or limited by small sample sizes. The aim of this study was to explore several patient and disease characteristics and their associations with pancreatic calcifications in a large cohort of CP patients with diverse aetiological risk factors.MethodsThis was a multicentre, cross-sectional study including 1509 patients with CP. Patient and disease characteristics were compared for patients with calcifications (n = 912) vs. without calcifications (n = 597). Multivariable logistic regression was performed to assess the parameters independently associated with calcifications.ResultsThe mean age of patients was 53.9 ± 14.5 years and 1006 (67%) were men. The prevalence of calcifications was 60.4% in the overall patient cohort, but highly variable between patients with different aetiological risk factors (range: 2–69%). On multivariate analysis, alcoholic aetiology (OR 1.76 [95% CI, 1.39–2.24]; p < 0.001) and smoking aetiology (OR 1.77 [95% CI, 1.39–2.26], p < 0.001) were positively associated with the presence of calcifications, while an autoimmune aetiology was negatively associated with calcifications (OR 0.15 [95% CI, 0.08–0.27], p < 0.001). Patients with pancreatic calcifications were more likely to have undergone pancreatic duct stenting (OR 1.59 [95%CI, 1.16–2.19], p = 0.004).ConclusionThe presence of pancreatic calcifications is associated with diverse aetiological risk factors in patients with CP. This observation attest to the understanding of CP as a complex disease and may have implications for disease classification.     

Prognostic implications of aquaporin-4 antibody status in neuromyelitis optica patients

Neuromyelitis optica (NMO) is an inflammatory/demyelinating disorder predominantly affecting the optic nerves and spinal cord. Recent findings showed an underlying humoral abnormality in NMO, characterized by a serum antibody against aquaporin-4 (Aqp-4-Ab). In this study, we evaluated the Aqp-4-Ab status among Turkish patients with NMO to determine the clinical and prognostic relevance. Serum samples from 35 consecutive patients with NMO followed at a single center and diagnosed according to the 2006 revised criteria, were evaluated for Aqp-4-Ab. All samples were obtained during a relapse prior to any immunosuppressive treatment. Aqp-4-Ab was positive in 21/35 (60%) patients. Among these cases, 11 had an EDSS of 6.0 or more, whereas only two patients in the seronegative group had such severe disability (p < 0.05). Overall, seropositive cases had a mean EDSS score of 5.1 ± 2.2 compared with 3.5 ± 1.7 in seronegative cases (p < 0.01). There were trends towards female predominance in seropositive cases and a monophasic course predominance in seronegative cases. Disease duration, age at onset, number of attacks and time to definite NMO did not differ between groups. Our findings in this single-center cohort suggest that the presence of Aqp-4-Ab might have a prognostic significance indicating a more severe disease course.