Common variation in NCAN, a risk factor for bipolar disorder and schizophrenia, influences local cortical folding in schizophrenia.

BACKGROUND: Recent studies have provided strong evidence that variation in the gene neurocan (NCAN, rs1064395) is a common risk factor for bipolar disorder (BD) and schizophrenia. However, the possible relevance of NCAN variation to disease mechanisms in the human brain has not yet been explored. Thus, to identify a putative pathomechanism, we tested whether the risk allele has an influence on cortical thickness and folding in a well-characterized sample of patients with schizophrenia and healthy controls. METHOD: Sixty-three patients and 65 controls underwent T1-weighted magnetic resonance imaging (MRI) and were genotyped for the single nucleotide polymorphism (SNP) rs1064395. Folding and thickness were analysed on a node-by-node basis using a surface-based approach (FreeSurfer). RESULTS: In patients, NCAN risk status (defined by AA and AG carriers) was found to be associated with higher folding in the right lateral occipital region and at a trend level for the left dorsolateral prefrontal cortex. Controls did not show any association (p > 0.05). For cortical thickness, there was no significant effect in either patients or controls. CONCLUSIONS: This study is the first to describe an effect of the NCAN risk variant on brain structure. Our data show that the NCAN risk allele influences cortical folding in the occipital and prefrontal cortex, which may establish disease susceptibility during neurodevelopment. The findings suggest that NCAN is involved in visual processing and top-down cognitive functioning. Both major cognitive processes are known to be disturbed in schizophrenia. Moreover, our study reveals new evidence for a specific genetic influence on local cortical folding in schizophrenia.

[A new gene locus for an autosomal-dominant non-syndromic hearing impairment (DFNA 33) is situated on chromosome 13q34-qter]. / Ein neuer Genort für eine autosomal-dominante, nichtsyndromale Schwerhörigkeit (DFNA33) liegt auf Chromosom 13q34-qter.

By investigation of a German family pedigree with non-syndromic hearing impairment of early onset and autosomal-dominant mode of inheritance, linkage to known DFNA loci was excluded, and the existence of a new locus (DFNA33) was revealed. In a subsequent genomic scan the phenotype was mapped to a 6 cM interval on chromosome 13q34-qter. A maximum two-point lod score of 2.96 was obtained for the marker D13S285 with a maximum lod score in the multipoint analysis of 3.28 at 124.56 cM.

Effect of regular sauna on epidermal barrier function and stratum corneum water-holding capacity in vivo in humans: a controlled study.

During the last few years, sauna has become the epitome of wellness. Besides studies in general medicine evaluating the health benefit of sauna, e.g. on the cardiovascular system, no systematic study regarding skin physiology has been published. The present exploratory study was intended to analyse the effect of regular Finnish sauna on skin physiology. The effect of regular sauna bathing was assessed with non-invasive instruments: stratum corneum water-holding capacity, skin redness, transepidermal water loss and surface skin pH were analysed in 41 healthy volunteers, aged 20-49 years, in a group with regular sauna exposure compared to a control group with no regular sauna exposure. A more stable epidermal barrier function, an increase in stratum corneum hydration, a faster recovery of both elevated water loss and skin pH after exposure to 2 x 15 min sauna at 80 degrees C could be demonstrated in volunteers with regular sauna. Heart beat rate and ionic concentration in sweat as well as epidermal blood perfusion showed a training effect under regular sauna. A decrease in casual skin sebum content on the skin surface of the forehead was observed in these volunteers. The present data suggest a protective effect of regular sauna on skin physiology, especially surface pH and stratum corneum water-holding capacity.

[A new locus for an autosomal dominant, non-syndromic hearing impairment (DFNA57) located on chromosome 19p13.2 and overlapping with DFNB15]. / Ein neuer Genort für eine autosomal dominante, nichtsyndromale Hörstörung (DFNA57) kartiert auf Chromosom 19p13.2 und überlappt mit DFNB15.

BACKGROUND: Non-syndromic hearing loss is the most genetically heterogeneous trait known in humans. To date, 54 loci for autosomal dominant non-syndromic sensorineural hearing loss (NSSHL) have been identified by linkage analysis. METHODS: In this study a German pedigree has been identified segregating a progressive bilateral loss of lower and middle frequencies. RESULTS: A genome-wide screening and linkage analysis revealed the existence of a new NSSHL locus (DFNA57). The phenotype was mapped to a 10 degrees Mbp interval on chromosome 19p13.2 from 7.8 to 18.2 degrees Mbp, a maximum 2-point LOD score of 3.08 was obtained for the marker D19S586. The region overlaps with the recessive locus DFNB15. CONCLUSION: The results underline the heterogeneity of hereditary hearing disorders. Identification of genes can help to reach a better understanding of the molecular mechanism of hearing.

Isoform-specific increase of spastin stability by N-terminal missense variants including intragenic modifiers of SPG4 hereditary spastic paraplegia.

Hereditary spastic paraplegia (HSP) is a neurodegenerative disorder selectively affecting axons of spinal cord motoneurons. Classical mutations in the most frequent HSP gene SPAST (spastin protein) act through haploinsufficiency by abolishing the activity of a C-terminal ATPase domain or by interfering with expression from the affected allele. N-terminal missense variants have been suggested to represent rare polymorphisms, to cause unusually mild phenotypes, and to aggravate the effect of a classical mutation. We confirm these associations for p.S44L but do not detect two other variants (p.E43Q; p.P45Q) in HSP patients and controls. We show that neither of several disease mechanisms associated with classical SPAST mutations applies to the N-terminal variants. Instead, all three alterations enhance the stability of one of two alternative spastin isoforms. Their phenotypic effect may thus not be mediated by haploinsufficiency but by increasing isoform competition for interacting proteins, substrates or oligomerization partners.

Mutation analysis of the spastin gene (SPG4) in patients in Germany with autosomal dominant hereditary spastic paraplegia.

Hereditary spastic paraplegias (HSP) comprise a genetically and clinically heterogeneous group of neurodegenerative disorders characterized by progressive spasticity and hyperreflexia of the lower limbs. Autosomal dominant hereditary spastic paraplegia 4 linked to chromosome 2p (SPG4) is the most common form of autosomal dominant hereditary spastic paraplegia. It is caused by mutations in the SPG4 gene encoding spastin, a member of the AAA protein family of ATPases. In this study the spastin gene of HSP patients from 161 apparently unrelated families in Germany was analyzed. The authors identified mutations in 27 out of the 161 HSP families; 23 of these mutations have not been described before and only one mutation was found in two families. Among the detected mutations are 14 frameshift, four nonsense, and four missense mutations, one large deletion spanning several exons, as well as four mutations that affect splicing. Most of the novel mutations are located in the conserved AAA cassette-encoding region of the spastin gene. The relative frequency of spastin gene mutations in an unselected group of German HSP patients is approximately 17%. Frameshift mutations account for the majority of SPG4 mutations in this population. The proportion of splice mutations is considerably lower than reported elsewhere.

Carbohydrate-deficient glycoprotein syndrome (CDGS)--glycosylation, folding and intracellular transport of newly synthesized glycoproteins.

Carbohydrate-deficient glycoprotein syndrome (CDGS) is a hereditary glycosylation disorder of unknown origin. In this study we used skin fibroblasts from patients with CDGS to study the glycosylation of three well characterized glycoproteins using gel mobility analysis, endoglycosidase treatments and protein folding studies. We show that glycoprotein transport along the secretory pathway was delayed. Dilation of the rough endoplasmic reticulum indicated a retention phenomenon for selected glycoproteins. However, for all examined glycoproteins cotranslational glycosylation in CDGS fibroblasts was normal.

Thyrotropin expression in hypophyseal pars tuberalis-specific cells is 3,5,3'-triiodothyronine, thyrotropin-releasing hormone, and pit-1 independent.

The expression of TSH subunit genes (TSH alpha and -beta) in pituitary thyrotropes is primarily regulated via circulating thyroid hormone levels (T3) and the hypothalamic TRH. Hypophyseal pars tuberalis (PT)-specific cells also express both hormonal subunits of TSH, but do not resemble thyrotropes of the pars distalis (PD) with respect to their distinct morphology, secretion, and direct modulation of TSH expression by photoperiodic inputs and melatonin. To investigate whether this distinct regulation of TSH is related to a different molecular structure or different signaling cascades, we analyzed PT-specific TSH and its transcriptional regulation in ovine PT-specific cells. After construction of PT- and PD-specific complementary DNA (cDNA) libraries, the cloning and sequencing of several TSH alpha and -beta subunit clones revealed identical sizes and sequences for the translated and untranslated regions in both hypophyseal compartments. Transcription start site analysis also displayed three identical start sites for the transcription of TSH beta in PT and PD. After cloning of the ovine TRH receptor cDNA and a partial T3 receptor cDNA, in situ hybridization. Northern blot analysis, and PCR experiments showed that TRH and T3 receptors are not expressed in specific cells of the PT. The transcription factor Pit-1 that is involved in TSH expression of thyrotropes could only be detected in the PD. In additional experiments rats were treated with T4 or TRH, and subsequent in situ hybridization studies showed that TSH beta messenger RNA (mRNA) formation was not altered in the PT. In the PD, however, TSH beta mRNA was significantly reduced in the T4-treated group, but was enhanced in the TRH-treated group. We conclude that PT-specific cells of the pituitary are characterized by the transcription of TSH subunits that are identical to TSH expressed in thyrotropes of the PD. The absence of TRH, T3 receptor mRNA, and Pit-1, respectively, as well as the different reactions compared to PD thyrotropes in in vivo experiments lead to the conclusion that the expression of TSH in PT-specific cells of the pituitary is not regulated via the classical thyrotrope receptors and their intracellular pathways, but through a novel, photoperiod-dependent mechanism.

A novel locus for autosomal dominant, non-syndromic hearing impairment (DFNA18) maps to chromosome 3q22 immediately adjacent to the DM2 locus.

Investigating a large German pedigree with non-syndromic hearing impairment of early onset and autosomal dominant mode of inheritance, linkage to known DFNA loci was excluded and in a subsequent genomic scan the phenotype was mapped to a 10-cM interval on chromosome 3q22; a maximum two-point lod score of 3.77 was obtained for the marker D3S1292. The new locus, DFNA18, is excluded from neighbouring deafness loci, DFNB15 and USH3, and it overlaps with the recently described DM2/PROMM locus. As hearing loss has been described as one feature of the PROMM phenotype, the DFNA18 gene might also be responsible for hearing loss in DM2/PROMM.

Nephropathic cystinosis (CTNS-LSB): construction of a YAC contig comprising the refined critical region on chromosome 17p13.

A yeast artificial chromosome (YAC) contig was constructed encompassing the entire region on chromosome 17p13 where the autosomal recessive disorder infantile nephropathic cystinosis (MIM 21980, CTNS-LSB) has been genetically mapped. It comprises seven clones ordered by their content of a series of six sequence-tagged sites (STSs). Fluorescence in situ hybridisation (FISH) revealed two chimaeric clones. The order of four polymorphic STSs mapped with the contig was consistent with that of the known genetic map with the exception of markers D17S1583 (AFMb307zg5) and D17S1798 (AFMa202xf5) where a telomeric location of D17S1583 was inferred from the contig; two non-polymorphic STSs were localised within the marker frame-work. From the analysis of recombination events in an unaffected individual as defined by leucocyte cystine levels we support the high-resolution mapping of this region to a small genetic interval and show that it is entirely represented on a single, non-chimaeric YAC clone in the contig.

Locus-specific detection of HLA-DQ and -DR antigens by antibodies against synthetic N-terminal octapeptides of the beta chain.

Antibodies against synthetic peptides representing the class-II antigen HLA-DR and -DQ beta chain N-terminal sequences were prepared in rabbits. The two octapeptides only share two amino acids and enzyme-linked immuno-assays showed the antisera only to bind to its own antigen. Both peptide antisera detected a 29 kDa component in immunoblots of Raji and AL-34 cell plasma membrane proteins separated by SDS gel electrophoresis. The binding of either N-terminal peptide antiserum was selectively inhibited only by the peptide used as antigen. Indirect immunofluorescence analysis by flow cytofluorometry showed specific surface immunofluorescence in 1:100-1:1000 dilutions in lymphoblastoid and blood mononucleated cells. In the latter the binding was primarily confined to monocytes and a subpopulation of lymphocytes. It is concluded that locus-specific immunological reagents to distinguish between beta chains of HLA-DR and -DQ have been prepared by the preparation by the production of antibodies against the N-terminal sequences of each polypeptide.

Features, symptoms, and neurophysiological findings in stroke associated with hyperhomocysteinemia.

BACKGROUND: Hyperhomocysteinemia has been shown to be a mild independent risk factor for premature atherosclerosis, and there is evidence of an increased rate of peripheral vascular occlusive disease, myocardial infarction, and stroke. OBJECTIVE: To evaluate clinical, biochemical, and neurophysiological findings in patients with ischemic stroke with and without hyperhomocysteinemia. SUBJECTS: One hundred twenty-five consecutive patients with a history of stroke and 60 healthy control subjects. METHODS: Patients were divided into those with and those without hyperhomocysteinemia, which was defined as blood levels beyond the mean total plasma homocysteine level plus 2 SDs of the healthy control group. History, symptoms, cause, patterns of infarction, biochemical data, continuous and transcranial Doppler sonography, and event-related potentials were recorded in all patients. RESULTS: Twenty-seven patients had hyperhomocysteinemia. Compared with the 98 patients without hyperhomocysteinemia, they had an increased rate of hypertension (odds ratio, 3.5; 95% confidence interval, 1.0-12.6), an increased level of uric acid (P < .007), an increased hematocrit (P < .02), a higher rate of microangiopathy (odds ratio, 2.8; 95% confidence interval, 1.1-7.2), and a trend to a higher rate of multiple infarction. Furthermore, the P3 latency of the event-related potential was significantly increased in hyperhomocysteinemia (P < .004). CONCLUSIONS: Hyperhomocysteinemia is probably an independent risk factor for stroke, with a prevalence of about 20% in all patients with a history of stroke; however, additional factors (eg, hypertension, hyperuricemia) may have an enhancing effect. There are significant differences in stroke patterns between patients with and without hyperhomocysteinemia, with a higher rate of lesions typical of cerebral microangiopathy and a trend to multiple infarctions in the former. Impairment of cognitive processing as measured by visual event-related potential is more pronounced in hyperhomocysteinemia.

Chronic myopathy in a patient suspected of carrying two malignant hyperthermia susceptibility (MHS) mutations.

Malignant hyperthermia (MH) is a pharmacogenetic myopathy triggered by a variety of anaesthetic agents and muscle relaxants. In humans, susceptibility to MH is inherited as an autosomal dominant trait, and susceptible patients do not show a clinically relevant myopathy unless having suffered from a MH crisis. Homozygosity for the MHS trait is thought to be an uncommon finding, and so far only a few cases of patients suggested to be homozygous for MH on the basis of pedigree information were reported and described as having a more severe form of this condition resulting in clinical symptoms also in the absence of triggering agents. We report clinical findings in a patient with chronic myopathy beginning at the age of 2 yr and associated with a number of unique features, the most important being a family history of MHS present in both parents. She became symptomatic with marked muscular weakness and elevated serum CK levels. A muscle biopsy showed a distinct enlargement and increase of muscle mitochondria. In the in vitro contracture test the patient's muscle responded with unusually high contractures already at basal levels of triggering agents indicating a particularly severe MHS condition. DNA markers for the MHS1 locus, described previously on chromosome 19q12-13.2 in Irish and Canadian pedigrees, could not be used to confirm her homozygous state because our molecular genetic studies had previously excluded the MHS trait in this pedigree from this locus.(ABSTRACT TRUNCATED AT 250 WORDS)

Predictive value of S-100beta and neuron-specific enolase serum levels for adverse neurologic outcome after cardiac surgery.

OBJECTIVES: The aim of this study was to evaluate the time course of S-100beta and neuron-specific enolase serum levels after cardiac surgery and their clinical relevance in predicting postoperative adverse neurologic outcomes; the 2 proteins are only released in peripheral blood in association with nervous system lesions. METHODS: We neurologically assessed 190 consecutive patients undergoing elective cardiac operations for coronary artery bypass (n = 147), valve replacement (n = 29), or both (n = 14), before as well as after the operation. Postoperative outcome was classified as type I (uncomplicated), type II (confusion, agitation, disorientation, or epileptic seizures), or type III (stroke, stupor, or coma). Levels of S-100beta and neuron-specific enolase were evaluated in venous blood samples drawn preoperatively and then daily in the first 5 postoperative days. RESULTS: Levels of S-100beta and neuron-specific enolase differed significantly among the 3 groups (type III > type II > type I) throughout the postoperative period and had a diagnostic specificity and specificity of 89% and 79%, respectively, in identifying patients with type III outcome. S-100beta (but not neuron-specific enolase) levels were identified as significant independent predictors for type II and III outcomes (odds ratio 16.2, P <.0004). The same was true for duration of cardiopulmonary bypass (odds ratio 1.02, P <.006). CONCLUSIONS: Serum levels of S-100beta are reliable markers for adverse neurologic outcomes after cardiac surgery.

Resistance to activated protein C (APCR) in children with acute lymphoblastic leukaemia--the need for a prospective multicentre study.

Activated protein C resistance (APCR), usually due to the Arg506-->Gln point mutation of the factor V gene, has emerged as the most important hereditary cause of venous thromboembolism. Using an aPTT based method in the presence of APC, together with a DNA technique based on the polymerase chain reaction, we investigated 65 leukaemic children and 65 age-matched healthy controls for the presence of this mutation. In both groups three children showed APCR. All six children showed the common factor V gene mutation, Arg506-->Gln. Although no child in the control group presented with thrombosis, all three children with acute lymphoblastic leukaemia had thromboembolic events. Whether the poor anticoagulant response to activated protein C in leukaemic children treated with prednisone, vincristine, daunorubicin and asparaginase affects the risk of thrombotic events requires a more extensive multicentre study.

Ciprofibrate--racemate and enantiomers: effects of a four-week treatment on male inbred Fischer rats. A biochemical and morphological study.

Ciprofibrates (racemate and both enantiomers, Raccip, R- and Scip) were administered orally in doses of 1 and 10 mg/kg once daily over 28 days to male inbred Fischer 344 rats, age 90-110 days at the beginning of the experiment. Body mass gain was observed in all groups. The 1 mg groups showed almost no difference to the control group. The 10 mg groups exhibited less body mass gain, most pronounced in the Scip group. Liver masses were increased in a dose dependent manner up to more than 200%, only the 10 mg Scip group was not significantly different from the 1 mg group which exhibited an increase in liver weight to about 175%. Also the kidney weights increased to 130%, whereas thymus and spleen weights were decreased in the high dose groups. Liver microsomal cytochromes P450 (P450) concentrations were not altered in the 1 mg groups and distinctly lowered in the 10 mg groups. Ethoxyresorufin and ethoxycoumarin O-deethylations were lowered in all experimental groups in a dose dependent manner, after administration of the high doses down to 30% of the control levels or less. Pentoxyresorufin O-depentylation, however, was increased in all 1 mg groups. In the high dose groups it was not altered. Ethylmorphine N-demethylation was decreased after administration of the high doses by about 50%, but only Scip decreased this reaction also after administration of the low dose. NADPH/Fe2+-stimulated microsomal luminol and lucigenin amplified chemiluminescence was increased, whereas hydrogen peroxide formation was depressed even by the low doses to 50% of the normal values, to about 25% by the high doses. Microsomal lipid peroxidation, however, was only slightly or not influenced. Glutathion concentrations (in the reduced and the oxidized form) were increased in a dose dependent manner by about 20 to 30%, the concentration of lipid peroxides was not significantly influenced. Thus, the effects of the enantiomers were not different and were similar to those of the racemate. In serum, cholesterol and triglycerides were only moderately lowered. Albumin concentrations were significantly enhanced in all groups, total proteins after 1 mg/kg Raccip only. Serum bilirubins were not altered, and among the indicator enzymes for liver damage only ALAT, alkaline phosphatase and the dehydrogenases were increased, in no case higher than twofold. Histologically distinct effects were seen after administration of both doses, more pronounced after 10 mg/kg, but with no differences between the enantiomers and Raccip: marked hypertrophy of the hepatocytes, reduced staining of the nuclei, strongly acidophilic granulated cytoplama, no basophilia of the cell bodies, loss of glycogen. These changes were most pronounced around the central veins. Hepatocyte apoptoses also were observed. By immunohistochemistry an increased staining was seen for all P450 isoforms tested (1A1, 2B1, 2E1, 3A2 and 4A1), predominantly perivenously and most pronounced after administration of the high doses without differences between Rcip, Scip or Raccip (preliminary results). By electron microscopy a moderate proliferation of peroxisomes after treatment with 1 mg/kg Cips with a ratio between mitochondria and peroxisomes of about 1:1 (controls: 10:1) was observed, and the peroxisomes were a more heterogeneous population. The relative portions of glycogen and both forms of the ER decreased. Treatment with 10 mg/kg Rcip, Scip or Raccip led to a strong increase in the number of peroxisomes, in some hepatocytes the ratio between mitochondria and peroxisomes was 1:3 with an increased heterogeneity among the peroxisomes evidenced by a broad range of electron densities. Most peroxisomes lacked a nucleoid. Thus, the biochemical effects differed only slightly and the morphological effects of the enantiomers were not different and were similar to those of the racemate.

Morphological and electrophysiological features of mature neurons in differentiated skin-derived precursor cells.

In vitro modelling of neuronal pathologies is, in particular, demanding and a lot of efforts have been undertaken to differentiate skin derived precursor cells into neuronal cells. However, so far all attempts did not result in cells with functional features of neurons like the ability to generate action potentials or synaptic activity. Here, we report that simple modifications of the protocols result in neuronal cells that display action potentials and synaptic activity. We think that our observation is an important step to model individual neuronal pathologies in vitro.