An extended association screen in multiple sclerosis using 202 microsatellite markers targeting apoptosis-related genes does not reveal new predisposing factors

Apoptosis, the programmed death of cells, plays a distinct role in the etiopathogenesis of Multiple sclerosis (MS), a common disease of the central nervous system with complex genetic background. Yet, it is not clear whether the impact of apoptosis is due to altered apoptotic behaviour caused by variations of apoptosis-related genes. Instead, apoptosis in MS may also represent a secondary response to cellular stress during acute inflammation in the central nervous system. Here, we screened 202 apoptosis-related genes for association by genotyping 202 microsatellite markers in initially 160 MS patients and 160 controls, both divided in 4 sets of pooled DNA samples, respectively. When applying Bonferroni correction, no significant differences in allele frequencies were detected between MS patients and controls. Nevertheless, we chose 7 markers for retyping in individual DNA samples, thereby eliminating 6 markers from the list of candidates. The remaining candidate, the ERBB3 gene microsatellite, was genotyped in additional 245 MS patients and controls. No association of the ERBB3 marker with the disease was detected in these additional cohorts. In consequence, we did not find further evidence for apoptosis-related genes as predisposition factors in MS.     

Validated 5' nuclease PCR assay for rapid identification of the genus Brucella

A real-time, genus-specific 5' nuclease PCR assay for amplification of a 322-bp fragment of the per gene was developed for rapid (<2 h) identification of Brucella spp. from agar plates. The assay, including an internal amplification control (116 bp), identified Brucella strains (n = 23) and did not detect non-Brucella strains (n = 174), indicating its usefulness, particularly for laboratories with stringent quality assurance programs.     

Second harmonic imaging of intrinsic signals in muscle fibers in situ

We use second harmonic generation (SHG) imaging to study and quantify a strong intrinsic SHG signal in skeletal muscle fiber preparations and single isolated myofibrils. The intrinsic signal follows the striation pattern of the muscle cells and is positioned at the sarcomeric location of the myosin filaments. Interestingly, the signal is enhanced at the region where the myosin heads are located on the myosin filaments. As the intrinsic signal reflects the subcellular structure in an accurate way, SHG can be used for noninvasive high resolution structural imaging without exogenous labels in living muscle cells. This may be very important for detecting changes in myofibrillar organization occurring under pathophysiological conditions, e.g., in cardiac and skeletal myopathies. Due to the strong dependency of SHG on orientation and symmetries of the tissue, it may allow the study of dynamic interactions between the contractile proteins actin and myosin during force production and muscle shortening. Furthermore, SHG imaging can be combined with other nonlinear microscopical techniques, such as laser scanning multiphoton fluorescence microscopy, to simultaneously measure other dynamic cellular processes, representing a complementary method and extending the range of nonlinear microscopical methods.     

Clustering patterns of LOD scores for asthma-related phenotypes revealed by a genome-wide screen in 295 French EGEA families

A genome-wide scan for asthma phenotypes was conducted in the whole sample of 295 EGEA families selected through at least one asthmatic subject. In addition to asthma, seven phenotypes involved in the main asthma physiopathological pathways were considered: SPT (positive skin prick test response to at least one of 11 allergens), SPTQ score being the number of positive skin test responses to 11 allergens, Phadiatop (positive specific IgE response to a mixture of allergens), total IgE levels, eosinophils, bronchial responsiveness (BR) to methacholine challenge and %predicted FEV(1). Four regions showed evidence for linkage (P相似文献   

The KBG syndrome: confirmation of autosomal dominant inheritance and further delineation of the phenotype

We report on a Turkish family in which the father and his two sons were diagnosed as having the KBG syndrome. Large upper central incisors were the diagnostic finding in all three patients along with mental retardation, cryptorchidism, skeletal abnormalities, and short stature. Our report clearly confirms that the inheritance is autosomal dominant in KBG syndrome, although a high male to female ratio has been observed in published cases.     

Current perspectives on HER2 testing: a review of national testing guidelines.

Knowledge of HER2 status is a prerequisite when considering a patient's eligibility for Herceptin (trastuzumab) therapy. Accurate assessment of HER2 status is essential to ensure that all patients who may benefit from Herceptin are correctly identified. There are several assays available to determine HER2 status: the most common in routine clinical practice are immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH). Various factors can affect the results achieved with these assays, including the assay antibody/probe, the methodology and the experience of personnel. Many countries have implemented national testing guidelines in an attempt to standardize testing procedures and make results more accurate. These guidelines vary in the level of detail and the number of recommendations. This review looks at areas of consensus between the different national testing guidelines and highlights where errors may arise during the testing procedure. The key point underlined by this review is that whatever method is used to test for HER2 status, the technology must be validated first, and there must be regular internal and external quality control and quality assurance procedures.     

Mice with neonatally induced inactivation of the vascular cell adhesion molecule-1 fail to control the parasite in Toxoplasma encephalitis

Under various inflammatory conditions, cell adhesion molecules are up-regulated in the central nervous system (CNS) and may contribute to the recruitment of leukocytes to the brain. In the present study, the functional role of vascular cell adhesion molecule (VCAM)-1 in Toxoplasma encephalitis (TE) was addressed using VCAM(flox/flox MxCre) mice. Neonatal inactivation of the VCAM-1 gene resulted in a lack of induction of VCAM-1 on cerebral blood vessel endothelial cells, whereas the constitutive expression of VCAM-1 on choroid plexus epithelial cells and the ependyma was unaffected; in these animals, resistance to T. gondii was abolished, and VCAM(flox/flox MxCre) mice died of chronic TE caused by a failure to control parasites in the CNS. Although leukocyte recruitment to the CNS was unimpaired, the B cell response was significantly reduced as evidenced by reduced serum levels of anti-T. gondii-specific IgM and IgG antibodies. Furthermore, the frequency and activation state of intracerebral T. gondii-specific T cells were decreased, and microglial activation was markedly reduced. Taken together, these data demonstrate the crucial requirement of VCAM-1-mediated immune reactions for the control of an intracerebral infectious pathogen, whereas other cell adhesion molecules can efficiently compensate for VCAM-1-mediated homing across cerebral blood vessels.     

Neuromuscular defects in a Drosophila survival motor neuron gene mutant

Autosomal recessive spinal muscular atrophy (SMA) is linked to mutations in the survival motor neuron (SMN) gene. The SMN protein has been implicated at several levels of mRNA biogenesis and is expressed ubiquitously. Studies in various model organisms have shown that the loss of function of the SMN gene leads to embryonic lethality. The human contains two genes encoding for SMN protein and in patients one of these is disrupted. It is thought the remaining low levels of protein produced by the second SMN gene do not suffice and result in the observed specific loss of lower motor neurons and muscle wasting. The early lethality in the animal mutants has made it difficult to understand why primarily these tissues are affected. We have isolated a Drosophila smn mutant. The fly alleles contain point mutations in smn similar to those found in SMA patients. We find that zygotic smn mutant animals show abnormal motor behavior and that smn gene activity is required in both neurons and muscle to alleviate this phenotype. Physiological experiments on the fly smn mutants show that excitatory post-synaptic currents are reduced while synaptic motor neuron boutons are disorganized, indicating defects at the neuromuscular junction. Clustering of a neurotransmitter receptor subunit in the muscle at the neuromuscular junction is severely reduced. This new Drosophila model for SMA thus proposes a functional role for SMN at the neuromuscular junction in the generation of neuromuscular defects.     

Influence of Verapamil and Cyclosporin A on bile acid metabolism and transport in rat liver slices.

Verapamil (V) is a specific inhibitor of the P-glycoprotein (mdr1) in the hepatocyte canalicular membrane. Cyclosporin A (CsA) as an essential immunosuppressive drug has potentially cholestatic adverse effects on the liver, but increases the expression of mdr1. In precision-cut liver slices from 34- to 40-day-old male Wistar rats 26 individual free and conjugated bile acids (BAs) as markers of hepatic transport and synthesis function were analysed after 4 h incubation with V (100 microM) or CsA (5 microM) in Krebs-Henseleit buffer. Some slices were loaded with cholic acid (CA 5 microM) or tauro-ursodeoxycholic acid (T-UDCA 5 microM) to investigate the V and CsA effects under conditions of BA supplementation. BAs were determined in tissue and medium by HPLC with postcolumn derivatisation and fluorescence detection. V and CsA, influencing different targets in BA transport, enhanced slice concentrations of T- and glyco- (G-) conjugated CA only when exogenous CA was given additionally. This BA accumulation in tissue is more reflected at decreased medium concentrations of these BAs after V and CsA incubations. Both V and CsA also inhibited CA uptake into the slices. The acidic chenodeoxycholic acid (CDCA) synthesis pathway is disturbed: T- and G-CDCA concentrations are diminished in slices and medium after V and CsA incubations. T-UDCA plus V or CsA enhanced not only its own slice concentration but also the concentration of the trihydroxylated tauro-muricholic acid (T-beta-MCA), reflecting the conversion of the accumulated dihydroxylated T-UDCA into the T-beta-MCA. The similar effects of V and CsA on BA transport and metabolism can be explained by mdr1 mediated disturbances of cellular ATP transport rather than by inhibition of individual BA transporters.