Evidence for rare and common genetic risk variants for schizophrenia at protein kinase C, alpha.

We earlier reported a genome-wide significant linkage to schizophrenia at chromosome 17 that was identified in a single pedigree (C702) consisting of six affected, male siblings with DSM-IV schizophrenia and prominent mood symptoms. In this study, we adopted several approaches in an attempt to map the putative disease locus. First, mapping the source of linkage to chromosome 17 in pedigree C702. We refined the linkage region in family C702 to a 21-marker segment spanning 11.7 Mb at 17q23-q24 by genotyping a total of 50 microsatellites across chromosome 17 in the pedigree. Analysis of data from 1028 single nucleotide polymorphisms (SNPs) across the refined linkage region identified a single region of homozygosity present in pedigree C702 but not in 2938 UK controls. This spanned ~432 kb of the gene encoding protein kinase C, alpha (PRKCA), the encoded protein of which has been implicated in the pathogenesis of psychiatric disorders. Analysis of pedigree C702 by oligonucleotide-array comparative genome hybridization excluded the possibility that this region of homozygosity was because of a deletion. Mutation screening of PRKCA identified a rare, four-marker haplotype (C-HAP) in the 3' untranslated region of the gene, which was present in the homozygous state in all six affected members of pedigree C702. No other homozygotes were observed in genotype data for a total of 6597 unrelated Europeans (case N=1755, control N=3580 and parents of probands N=1262). Second, association analysis of C702 alleles at PRKCA. The low-frequency haplotype (C-HAP) showed a trend for association in a study of unrelated schizophrenia cases and controls from the UK (661 cases, 2824 controls, P=0.078 and odd ratio (OR)=1.9) and significant evidence for association when the sample was expanded to include cases with bipolar (N=710) and schizoaffective disorder (N=50) (psychosis sample: 1421 cases, 2824 controls, P=0.037 and OR=1.9). Given that all the affected members of C702 are male, we also undertook sex-specific analyses. This revealed that the association was strongest in males for both schizophrenia (446 male cases, 1421 male controls, P=0.008 and OR=3.9) and in the broader psychosis group (730 male cases, 1421 male controls, P=0.008 and OR=3.6). Analysis of C-HAP in follow-up samples from Ireland and Bulgaria revealed no evidence for association in either the whole sample or in males alone, and meta-analysis of all male psychosis samples yielded no significant evidence of association (969 male cases, 1939 male controls, 311 male probands P=0.304 and OR=1.4). Third, association mapping of the pedigree C702 linkage region. Independent of pedigree C702, genotype data from the Affymetrix 500k GeneChip set were available for 476 patients with schizophrenia and 2938 controls from the United Kingdom. SNPs in PRKCA showed evidence for association with schizophrenia that achieved gene-wide significance (P=0.027). Moreover, the same SNP was the most significantly associated marker out of the 1028 SNPs genotyped across the linkage region (rs873417, allelic P=0.0004). Follow-up genotyping in samples from Ireland, Bulgaria and Germany did not show consistent replication, but meta-analysis of all samples (4116 cases and 6491 controls) remained nominally significant (meta-analysis P=0.026, OR=1.1). We conclude that, although we have obtained convergent lines of evidence implicating both rare and common schizophrenia risk variants at PRKCA, none of these is individually compelling. However, the evidence across all approaches suggests that further study of this locus is warranted.

Analysis of 10 independent samples provides evidence for association between schizophrenia and a SNP flanking fibroblast growth factor receptor 2.

We and others have previously reported linkage to schizophrenia on chromosome 10q25-q26 but, to date, a susceptibility gene in the region has not been identified. We examined data from 3606 single-nucleotide polymorphisms (SNPs) mapping to 10q25-q26 that had been typed in a genome-wide association study (GWAS) of schizophrenia (479 UK cases/2937 controls). SNPs with P<0.01 (n=40) were genotyped in an additional 163 UK cases and those markers that remained nominally significant at P<0.01 (n=22) were genotyped in replication samples from Ireland, Germany and Bulgaria consisting of a total of 1664 cases with schizophrenia and 3541 controls. Only one SNP, rs17101921, was nominally significant after meta-analyses across the replication samples and this was genotyped in an additional six samples from the United States/Australia, Germany, China, Japan, Israel and Sweden (n=5142 cases/6561 controls). Across all replication samples, the allele at rs17101921 that was associated in the GWAS showed evidence for association independent of the original data (OR 1.17 (95% CI 1.06-1.29), P=0.0009). The SNP maps 85 kb from the nearest gene encoding fibroblast growth factor receptor 2 (FGFR2) making this a potential susceptibility gene for schizophrenia.

Co-morbidity in a cystic fibrosis population attending a regional clinic.

Pulmonary disease remains the major cause of morbidity in patients with cystic fibrosis (CF). However, of 115 patients attending a regional CF clinic we noted 16 cases (14%) with co-morbid conditions. Of this group, 4 of 115 patients (3.5%) had renal problems including both structural and functional defects and 4 (3.5%) had neurological disorders, 3 of which were types of epilepsy. Notably, 3 of 115 patients (2.6%) had different forms of neoplasia, all of which required significant surgical and/or chemotherapeutic intervention. There is now increasing evidence of the association between digestive tract malignancy and CF, which further complicates management of these already complex cases.

Association analysis of the glial cell line-derived neurotrophic factor (GDNF) gene in schizophrenia.

The glial cell line-derived neurotrophic factor (GDNF) gene is located within a region of chromosome 5 (5p14.1-q13.3) that has been highlighted as a potential schizophrenia susceptibility locus by a number of genome scans. GDNF is neurotrophic and is also thought to be involved in differentiation of dopaminergic neurones. The GDNF gene is, therefore, a positional and functional candidate gene for schizophrenia. It is of additional interest because altered GDNF mRNA and protein expression has been reported in response to antipsychotics and the psychotomimetic phencyclidine, and two previous studies, focussed on a single variant, have reported weak support for genetic association between GDNF and schizophrenia in small samples. To test the hypothesis that GDNF is a susceptibility gene for schizophrenia, we performed a detailed association study. We chose 9 SNPs that spanned a genomic region of 40 kb and fully encompassed GDNF. SNPs were genotyped in a sample of 673 schizophrenic patients and 716 matched controls, all of Caucasian origin and all collected from the UK or Ireland. Of the 9 SNPs genotyped 2 showed nominally significant genotypic association at the P< or =0.05 level (rs2973050; OR=1.11; P-value=0.007 and rs2910702; OR=1.14; P-value=0.039). Permutation testing to allow for multiple comparisons of non-independent markers gave a corrected genotypic P-value of 0.052 for rs2973050. We also genotyped an (AGG)(n) repeat located in the 3' UTR of the GDNF but this showed no evidence for association. We conclude that our sample does not provide independent statistically significant evidence for association between GDNF and schizophrenia, nor does it replicate previous specific reports of association.

Retropharyngeal abscess following endotracheal intubation.

Retropharyngeal abscess is an unusual complication of endotracheal intubation. We present a case in which such a lesion developed following traumatic intubation in an emergency situation.

Fatal tension pneumopericardium complicating tracheostomy.

The findings in a patient who developed a fatal pneumopericardium following tracheostomy are reported. This complication of tracheostomy does not appear to have been reported previously in the literature.. When recognized, pneumopericardium is a treatable lesion, and clinicians should be aware of this potential complication.

Levels of cefuroxime in bronchial secretion.

Levels of cefuroxime in bronchial secretion were measured in 49 patients requiring bronchoscopy for diagnostic purposes. Patients were randomly allocated to one of 4 groups which differed with respect to the size (750 mg or 1.5 g) and number (1 or 7) of intravenous doses of cefuroxime given approximately 1 hour prior to sampling. Levels of cefuroxime achieved after administration of all 4 dosages were sufficient to exceed the MIC values for the major chest pathogens. Penetration of cefuroxime into bronchial secretion was also found to be dose-related.

Stimulation by cigarette smoke of glutathione peroxidase system enzyme activities in rat lung.

This study was undertaken to evaluate the effect of in vivo cigarette smoke exposure on glutathione peroxidase--related enzyme systems of the rat lung. These enzymes, acting in concert, are thought to be responsible for disposing of toxic lipid peroxides in pulmonary tissue. Thirty-day-old rats were exposed to thirteen cigarettes per day for 21 days with a Walton reverse-smoking exposure apparatus. After 21 days of smoke exposure, the activities of glutathione peroxidase, glutathione reductase, and glucose-6-phosphate dehydrogenase were increased 34%, 24%, and 38%, respectively, over control values. This level of cigarette smoke exposure did not cause detectable histological lesions. We present the hypothesis that short-term, low-level cigarette smoke exposure is capable of initiating metabolic alterations in lung cells at exposures at which histological changes are not detectable by light microscopy.

Biochemical effect of ozone exposure in rats exposed to cigarette smoke.

Rats were exposed to three cigarettes per day for 35 days, under realistic conditions. Pulmonary glucose-6-phosphate dehydrogenase (G-6-PD) activity in the exposed animals increased 27% over control values (P less than .05). Subsequent exposure to acute, high-dose ozone (3 ppm for 4 hr) decreased the augmented G-6-PD activities to near normal levels, whereas ozone exposures in animals not exposed to cigarette smoke caused mild decreases in pulmonary G-6-PD activities. The importance of these findings with respect to the susceptibility of the smoker to oxidant exposures is unknown.

Mesenteric vasculitis in adults with Henoch-Schonlein purpura: a not-so-benign condition.

INTRODUCTION: The gastrointestinal manifestations of Henoch-Schonlein purpura (HSP) are well characterised, but their recognition can be difficult when they occur in isolation. Furthermore, HSP can run a more serious course in adults, compared to children, in whom the disease usually occurs. MATERIALS AND METHODS: We describe two cases that illustrate the challenges of HSP with mesenteric vasculitis and the outcome in adults. CONCLUSION: Although self-limiting in most patients, the outcome of HSP in adults can be far from benign and even fatal.

Molecular dissection of NRG1-ERBB4 signaling implicates PTPRZ1 as a potential schizophrenia susceptibility gene.

Neuregulin and the neuregulin receptor ERBB4 have been genetically and functionally implicated in schizophrenia. In this study, we used the yeast two-hybrid system to identify proteins that interact with ERBB4, to identify genes and pathways that might contribute to schizophrenia susceptibility. We identified the MAGI scaffolding proteins as ERBB4-binding proteins. After validating the interaction of MAGI proteins with ERBB4 in mammalian cells, we demonstrated that ERBB4 expression, alone or in combination with ERBB2 or ERBB3, led to the tyrosine phosphorylation of MAGI proteins, and that this could be further enhanced with receptor activation by neuregulin. As MAGI proteins were previously shown to interact with receptor phosphotyrosine phosphatase beta/zeta (RPTPbeta), we postulated that simultaneous binding of MAGI proteins to RPTPbeta and ERBB4 forms a phosphotyrosine kinase/phosphotyrosine phosphatase complex. Studies in cultured cells confirmed both a spatial and functional association between ERBB4, MAGI and RPTPbeta. Given the evidence for this functional association, we examined the genes coding for MAGI and RPTPbeta for genetic association with schizophrenia in a Caucasian United Kingdom case-control cohort (n= approximately 1400). PTPRZ1, which codes for RPTPbeta, showed significant, gene-wide and hypothesis-wide association with schizophrenia in our study (best individual single-nucleotide polymorphism allelic P=0.0003; gene-wide P=0.0064; hypothesis-wide P=0.026). The data provide evidence for a role of PTPRZ1, and for RPTPbeta signaling abnormalities, in the etiology of schizophrenia. Furthermore, the data indicate a role for RPTPbeta in the modulation of ERBB4 signaling that may in turn provide further support for an important role of neuregulin/ERBB4 signaling in the molecular basis of schizophrenia.

No support for association between the dopamine transporter (DAT1) gene and ADHD.

Several groups have reported an association between the 10-repeat allele of a dopamine transporter (DAT1) 3'UTR VNTR variant and ADHD but the finding has not been universally observed. An association between DAT1 genotype and stimulant medication response has also been reported although again there are conflicting data. We tested the DAT1 3'VNTR and three SNPs in the putative promoter region of DAT1 for association with ADHD in 263 parent-proband trios. Analyses of genotypes, alleles, and haplotypes were performed using family-based association methods. Case-control analysis of the VNTR in 263 cases and 287 controls was also conducted. In addition, we tested for association between the VNTR marker and stimulant medication response. Comparing allele 10 versus all other alleles combined, no significant association was found with ADHD, using FBAT analysis (chi2 = 0.1 (df 1), P = 0.9, (odds ratio (OR) = 1.0, 95% CI 0.8-1.2), and case-control analysis (chi2 = 0.12 (df 2), P = 0.91). No evidence of association with any of the SNPs in the promoter region was found. Haplotype analysis was also non-significant (chi2 = 3.93, (df 9) global P = 0.85). Finally, no association was found between the DAT 1 VNTR and response to stimulant medication (chi2 = 1.63 (df 3) P = 0.65). We conclude that the 3' VNTR and three additional promoter variants in DAT1 do not appear to be associated with ADHD, or response to stimulant mediation in our sample.

Ceftazidime in the treatment of lower respiratory tract infection.

Forty patients with acute lower respiratory tract infection requiring hospital admission were treated with ceftazidime. One patient developed acute dyspnoea after the first dose of the drug which was considered to be drug related and treatment was discontinued. All remaining patients were clinically assessed as being either cured or improved. In all cases that were bacteriologically assessable the pathogens were eradicated. One patient developed erythema multiforme after the end of ceftazidime treatment; this was considered to be possibly drug related.

Removal of endobronchial foreign body by fiberoptic bronchoscopy.

A relatively large foreign body (ham bone) was seen in the left upper lobe bronchus of a 25-year-old woman and was successfully extracted with the use of a standard fiberoptic bronchoscope. Although the removal of foreign bodies by the fiberoptic bronchoscope has serious technical limitations, the use of this instrument should be considered when the foreign body is not within range of the rigid bronchoscope.

Trimethoprim-sulfamethoxazole in chronic bronchitis.

Authenic tracheobronchial secretions/exudates (TBSE) were aspirated under direct vision via a sterile catheter passed through a fiberoptic bronchoscope from patients with chronic obstructive pulmonary disease complicated by chronic bronchitis. TBSE, saliva and blood were obtained during long-term administration of trimethoprim-sulfamethoxazole (TMP-SMX) and were assayed for drug content. Before and during treatment TBSE were cultured qualitatively and quantitatively for aerobic and anaerobic bacteria, fungi, mycoplasmas and viruses. Treatment with TMP-SMX was associated with a decrease in the recovery of Hemophilus influenzae, H. parainfluenzae, Klebsiella pneumoniae, Escherichia coli and Proteus mirabilis; however, little effect was observed on the typically nonpathogenic aerobic and anaerobic bacteria of the upper respiratory tract. TMP was found in saliva at concentrations greater than in serum. Both TMP and SMX entered TBSE in absolute and relative concentrations sufficient to take advantage of the potential for synergy against susceptible microorganisms. Patient tolerance of TMP-SMX was generally good and several patients reported a decrease in production of sputum during treatment.

Oxygen toxicity: augmentation of antioxidant defense mechanisms in rat lung.

In studies directed at determining the activities of selected enzymes in lung tissue after in vivo exposure to hyperoxia, 70-day-old rats were exposed to 85% or 90% O2 for 1-14 days. After 7 days of exposure to 90% O2 (1atm), superoxide dismutase activities in mitochondrial and cytosolic fractions increased, respectively, to 245 and 145% of control; glutathione peroxidase, glutathione reductase, and glucose-6-phosphate dehydrogenase activities increased, respectively, to 317, 175, and 413% of control. The levels of reduced glutathione and total nonprotein sulfhydryl compounds were elevated to 195% and 365% of control. Similar changes were observed in rats exposed to 85% O2 for up to 14 days, but to a lesser degree. The changes are interpreted as a reflection of the overall magnitude of oxidant-induced lung injury-reparative processes. The results suggest that hyperoxia induces an increase in lung "antioxidant" defense capabilities. This apparent adaptive response may be important in decreasing the susceptibility of lung tissue to continued O2 toxicity.

Clinical evaluation of perhexiline maleate in patients with angina pectoris.

This paper reports a double-blind trial of a new antianginal drug, perhexiline. Fifty-five patients suffering from angina pectoris were studied for periods of 12 or 24 weeks in a cross-over comparison against a placebo in four centres in the United Kingdom and Ireland. Perhexiline was effective in most patients as judged by reducing the number of anginal attacks in 84% and the consumption of glyceryl trinitrate tablets in 64%. The major side effect, dizziness, noted in one-third of the patients, may be dose/body-weight related. Perhexiline is a valuable new agent for the treatment of patients with angina, especially those who do not respond to other antianginal agents.