Serotonin mediates PGE<Subscript>2</Subscript> overexpression through 5-HT<Subscript>2A</Subscript> and 5-HT<Subscript>3</Subscript> receptor subtypes in serum-free tissue culture of macrophage-like synovial cells

Serotonin antagonists show impressive analgesic efficacy in rheumatoid arthritis, osteoarthritis (OA) or fibromyalgia; however, this effect is not well understood. We examined the mechanism of serotonin-induced inflammation and its antagonists in OA. Serotonin receptor subtypes and COX-2 were analysed by RT-PCR from synovial tissue. Serum-free cultures were stimulated with 10 muM serotonin and/or the antagonists ketanserin (5-HT(2A)), tropisetron (5-HT(3)) and parecoxib (COX-2). Prostaglandin E(2) (PGE(2)), tumour necrosis factor alpha (TNF-alpha), interleukin 1beta (IL-1beta) and leukotriene B4 (LTB4) were measured by an immunoassay in the supernatants. RT-PCR results showed mRNA for 5-HT(2A) and 5-HT(3) receptors, and COX-2. PGE(2) in the supernatants increased by 261.2% +/- 56.7 (mean +/- SEM; P = 0.007) in response to serotonin. TNF-alpha, IL-1beta and LTB4 levels did not change. Ketanserin, tropisetron and parecoxib suppressed PGE(2). The serotonin-induced PGE(2) overexpression appeared thus to be mediated by 5-HT(2A) and 5-HT(3) receptors. This activation might involve COX-2. The findings may explain the potent benefit of 5-HT(3) antagonists.     

ADP-ribosylation factor and phosphatidic acid levels in Golgi membranes during budding of coatomer-coated vesicles

The finding that ADP-ribosylation factor (ARF) can activate phospholipase D has led to debate as to whether ARF recruits coat proteins through direct binding or indirectly by catalytically increasing phosphatidic acid production. Here we test critical aspects of these hypotheses. We find that Golgi membrane phosphatidic acid levels do not rise—in fact they decline—during cell-free budding reactions. We confirm that the level of membrane-bound ARF can be substantially reduced without compromising coat assembly [Ktistakis, N. T., Brown, H. A., Waters, M. G., Sternweis, P. C. & Roth, M. G. (1996) J. Cell Biol. 134, 295–306], but find that under all conditions, ARF is present on the Golgi membrane in molar excess over bound coatomer. These results do not support the possibility that the activation of coat assembly by ARF is purely catalytic, and they are consistent with ARF forming direct interactions with coatomer. We suggest that ARF, like many other G proteins, is a multifunctional protein with roles in trafficking and phospholipid signaling.     

Implantable Cardioverter-Defibrillators in Children and Adolescents With Brugada Syndrome

Background

Young patients presenting with symptomatic Brugada syndrome have very high risks for ventricular arrhythmias and should be carefully considered for implantable cardioverter-defibrillator (ICD) placement. However, this therapy is associated with high rates of inappropriate shocks and device-related complications.

Are radiographic indices reliable indicators for quantitative bone mineral density and vitamin D status after femoral neck fractures? A retrospective study in 112 elderly patients

Background

Radiographic parameters and indices obtained from hip x-rays are a potential tool to promptly estimate bone quality in elderly hip fracture patients. Preoperative decision in whether to use cemented or cement augmented implants might be supported by this information and thus improve patient safety. Subsequently, this study was conducted to evaluate radiographic parameters as a prescreening tool for bone quality.

Methods

A retrospective analysis of 112 elderly patients with a femoral neck fracture after low-energy trauma was performed (81 % female, 19 % male). Three radiological indices were calculated on hip x-rays: cortical index antero-posterior CTI (ap), cortical index lateral CTI (lat) and canal to calcar ratio CCR. These indices were analyzed for correlations with DXA T-Scores and serum 25-hydroxyvitamin D (25(OH)D) using the Spearman test.

Results

Median age of patients was 80 (IQR 72–86) years. A linear correlation was found for CTI (lat) and T-Score at the total hip (p?<?0.001, r?=?0.589), femoral neck (p?=?0.005, r?=?0.405) and the lumbar spine (p?=?0.002, r?=?0.299). A significant correlation was also indicated between CTI (lat) and 25(OH)D (p?=?0.002, r?=?0.293). CTI (lat) at a cut-off level of 0.4 showed a sensitivity of 79 % and a specificity of 56 % in predicting a T-score?≤??2.5 at the total hip. Gender specific analysis revealed a higher sensitivity (100 %) and specificity (73 %) of CTI (lat) at a cut-off level of 0.4 for men. For severe vitamin D deficiency (<10 ng/ml) sensitivity and specificity were 75 % and 65 %.

Conclusion

Radiographic indices as the CTI (lat) exhibit a direct correlation to BMD and serum 25OH vitamin D levels. A CTI (lat) cut-off level of 0.4 is recommended for identifying patients at risk of osteoporosis expressed by T-Scores?≤??2.5 and severe vitamin D deficiency.

     

Autosomal dominant SCA5 and autosomal recessive infantile SCA are allelic conditions resulting from SPTBN2 mutations

Although many genes have been identified for the autosomal recessive cerebellar ataxias (ARCAs), several patients are unlinked to the respective loci, suggesting further genetic heterogeneity. We combined homozygosity mapping and exome sequencing in a consanguineous Egyptian family with congenital ARCA, mental retardation and pyramidal signs. A homozygous 5-bp deletion in SPTBN2, the gene whose in-frame mutations cause autosomal dominant spinocerebellar ataxia type 5, was shown to segregate with ataxia in the family. Our findings are compatible with the concept of truncating SPTBN2 mutations acting recessively, which is supported by disease expression in homozygous, but not heterozygous, knockout mice, ataxia in Beagle dogs with a homozygous frameshift mutation and, very recently, a homozygous SPTBN2 nonsense mutation underlying infantile ataxia and psychomotor delay in a human family. As there was no evidence for mutations in 23 additional consanguineous families, SPTBN2-related ARCA is probably rare.     

TET2 mutations in cytogenetically normal acute myeloid leukemia: Clinical implications and evolutionary patterns

Mutations of the Ten‐Eleven‐Translocation 2 (TET2) gene have been identified in patients with various myeloid neoplasms, but the clinical relevance of these mutations and their timing during disease development in cytogenetically normal acute myeloid leukemia (CN‐AML) remain unclear. The total coding region of TET2 was analyzed by direct sequencing in 215 CN‐AML patients younger than 60 years from multicenter treatment trials AML‐SHG 0199 (ClinicalTrials Identifier NCT00209833) and 0295. Associations were analyzed in the context of other molecular markers, such as CEBPA, DNMT3A, NMP1, FLT3, IDH1/2, RAS, and WT1. To investigate the order of appearance of TET2 and concomitant mutations, targeted deep resequencing was performed in six patients. At least one sequence variation with impact on TET2 protein sequence was found in 13 of the 215 CN‐AML patients (6%). Patients with TET2 mutations tended to be older (P = 0.078) and had higher platelet counts (P = 0.041). TET2‐mutated patients were more likely to have concomitant NPM1 (11 of 13; P = 0.047) and DNMT3A (10 of 13; P = 0.001) mutations but were mutually exclusive to partial tandem duplication of the MLL gene (MLL‐PTD) and IDH1/2 mutations. TET2 mutations were identified as subclones in four of the six investigated patients by deep sequencing. Progenitor‐derived colony assays suggest a stepwise acquisition of mutations during disease development, TET2 mutation being later than NPM1 and DNMT3A. The TET2 mutation status did not influence overall or relapse‐free survival. © 2014 Wiley Periodicals, Inc.