Association analyses suggest GPR24 as a shared susceptibility gene for bipolar affective disorder and schizophrenia

Linkage analyses suggest that chromosome 22q12-13 may harbor a shared susceptibility locus for bipolar affective disorder (BPD) and schizophrenia (SZ). In a study of a sample from the Faeroe Islands we have previously reported association between both disorders and microsatellite markers in a 3.6 cM segment on 22q13. The present study investigated three candidate genes located in this segment: GPR24, ADSL, and ST13. Nine SNPs located in these genes and one microsatellite marker (D22S279) were applied in an association analysis of two samples: an extension of the previously analyzed Faeroese sample comprising 28 distantly related cases (17 BPD, 11 SZ subjects) and 44 controls, and a Scottish sample including 162 patients with BPD, 103 with SZ, and 200 controls. In both samples significant associations were observed in both disorders with predominantly GPR24 SNPs and haplotypes. In the Faeroese sample overall P-values of 0.0009, 0.0054, and 0.0023 were found for haplotypes in BPD, SZ, and combined cases, respectively, and in the Scottish sample overall P-values of 0.0003, 0.0005, and 0.016 were observed for similar groupings. Specific haplotypes showed associations with lowest P-values of 7 x 10(-5) and 0.0006 in the combined group of cases from the Faeroe Islands and Scotland, respectively. The G protein-coupled receptor 24 encoded by GPR24 binds melanin-concentrating hormone (MCH) and has been implicated with feeding behavior, energy metabolism, and regulation of stress and mood. To our knowledge this is the first study reporting association between GPR24 and BPD and SZ, suggesting that GPR24 variants may confer susceptibility to both disorders.

A genome-wide search for alleles and haplotypes associated with autism and related pervasive developmental disorders on the Faroe Islands

The involvement of genetic factors in the etiology of autism has been clearly established. We undertook a genome-wide search for regions containing susceptibility genes for autism in 12 subjects with childhood autism and related pervasive developmental disorders (PDDs) and 44 controls from the relatively isolated population of the Faroe Islands. In total, 601 microsatellite markers distributed throughout the human genome with an average distance of 5.80 cM were genotyped, including 502 markers in the initial scan. The Faroese population structure and genetic relatedness of cases and controls were also evaluated. Based on a combined approach, including an assumption-free test as implemented in CLUMP, Fisher's exact test for specific alleles and haplotypes, and IBD(0) probability calculations, we found association between autism and microsatellite markers in regions on 2q, 3p, 6q, 15q, 16p, and 18q. The most significant finding was on 3p25.3 (P(T1)=0.00003 and P(T4)=0.00007), which was also supported by other genetic studies. Furthermore, no evidence of population substructure was found, and a higher degree of relatedness among cases could not be detected, decreasing the risk of inflated P-values. Our data suggest that markers in these regions are in linkage disequilibrium with genes involved in the etiology of autism, and we hypothesize susceptibility genes for autism and related PDDs to be localized within these regions.

Intra-arterial cisplatin and concomitant radiation therapy followed by surgery for advanced paranasal sinus cancer

OBJECTIVE

To report the long-term efficacy of a combined regimen of intra-arterial high-dose cisplatin chemotherapy and concomitant radiation therapy followed by organ-sparing surgery when possible in the treatment of advanced paranasal sinus cancer.

DESIGN

Review of prospectively collected data.

SETTING

Academic referral center. Patients Nineteen patients with advanced paranasal sinus malignancies with a minimum follow-up of 2 years. Malignancies included 14 squamous cell carcinomas (74%), 2 adenocarcinomas (10%), 2 adenoid cystic carcinomas (10%), and 1 undifferentiated carcinoma (5%). Sixteen patients (84%) had T4 disease. Intervention Treatment consisted of preoperative radiation therapy (2.0 Gy/fraction per day; total dose, 50 Gy in 5 weeks) given concomitantly with 3 to 4 weekly infusions of intra-arterial cisplatin (150 mg/m(2) per week) and systemic sodium thiosulfate neutralization. The regimen included planned surgery performed approximately 8 weeks after completion of radiation therapy. Ten patients underwent a transcranial anterior craniofacial resection; 1, a medial maxillectomy; and 1, an endoscopic restaging only.

RESULTS

After a median follow-up of 53 months, actuarial overall survival at 2 and 5 years was 68% and 53%, respectively. One patient died of myocardial infarction during treatment. No other treatment-limiting toxic effect was noted. Although 3 patients had persistence of disease, delayed local failure occurred only in 2 and distant metastasis in 3. Except for cataract in 2 patients, no visual loss developed.

CONCLUSION

Despite the advanced stage and unfavorable nature of cancer in this cohort, our results indicate that this regimen holds promise and merits further study.

Possible evidence for a common risk locus for bipolar affective disorder and schizophrenia on chromosome 4p16 in patients from the Faroe Islands

Patients with schizophrenia (n=11) and bipolar affective disorder (n=17) from the relatively isolated population of the Faroe Islands were genotyped for 34 polymorphic markers on chromosome 4 in a search for allelic association and haplotype sharing among distantly related patients. When considering bipolar patients only, there was no clearcut support for any region on chromosome 4. The two-marker segment D4S394-D4S2983 at 4p16.1 was, however, supported by a P-value of 0.0162. For patients with schizophrenia, there was reasonable support for 4p16.1 as marker D4S2281 (P=0.0019), a two-marker segment (D4S2281-D4S1605, P=0.0009) and a three-marker segment (D4S2923-D4S2928-D4S1582, P-0.0005) appeared to be associated with schizophrenia, with some alleles/haplotypes occurring with different frequencies in patients compared to controls. When combining both psychiatric disorders, chromosome 4p16.1 received further support from five partially overlapping two- and three-marker segments (D4S394-D4S2983, P=0.0039; D4S2281-D4S1605, P=0.0027 and D4S394-D4S2983-D4S2923, P=0.006; D4S2923-D4S2928-D4S1582, P=0.00007; D4S1582-D4S1599-D4S2281, P=0.005). Increased haplotype sharing in patients with schizophrenia and in the combined data set was partly supported by Fisher's exact test and tests based on the genealogy. Our study yields support for a common risk gene for schizophrenia and bipolar affective disorder on the short arm of chromosome 4, as suggested by previous findings in the neighbouring Scottish population.

Search for common haplotypes on chromosome 22q in patients with schizophrenia or bipolar disorder from the Faroe Islands

Chromosome 22q may harbor risk genes for schizophrenia and bipolar affective disorder. This is evidenced through genetic mapping studies, investigations of cytogenetic abnormalities, and direct examination of candidate genes. Patients with schizophrenia and bipolar affective disorder from the Faroe Islands were typed for 35 evenly distributed polymorphic markers on 22q in a search for shared risk genes in the two disorders. No single marker was strongly associated with either disease, but five two-marker segments that cluster within two regions on the chromosome have haplotypes occurring with different frequencies in patients compared to controls. Two segments were of most interest when the results of the association tests were combined with the probabilities of identity by descent of single haplotypes. For bipolar patients, the strongest evidence for a candidate region harboring a risk gene was found at a segment of at least 1.1 cM including markers D22S1161 and D22S922 (P=0.0081 in the test for association). Our results also support the a priori evidence of a susceptibility gene to schizophrenia at a segment of at least 0.45 cM including markers D22S279 and D22S276 (P=0.0075). Patients were tested for the presence of a missense mutation in the WKL1 gene encoding a putative cation channel close to segment D22S1161--D22S922, which has been associated with schizophrenia. We did not find this mutation in schizophrenic or bipolar patients or the controls from the Faroe Islands.

Further evidence for a bipolar risk gene on chromosome 12q24 suggested by investigation of haplotype sharing and allelic association in patients from the Faroe Islands

A number of studies have strongly suggested a susceptibility locus for bipolar affective disorder on chromosome 12q24. The present study investigates for a shared chromosomal segment among distantly related patients with bipolar affective disorder from the Faroe Islands, using 17 microsatellite markers covering 24 cM in the previously suggested region on chromosome 12q24. D12S342 showed possible allelic association to bipolar affective disorder (P-value using CLUMP below 0.01). Increased sharing among cases of two-marker haplotypes were suggested at D12S1614--D12S342 (P-values using CLUMP below 0.01), and D12S2075--D12S1675 (P-values using CLUMP around 0.001). The region of most interest is around 6 cM and bounded by markers D12S1614 and D12S1675 as suggested by the interesting two-marker haplotypes. This area contains the minimum interesting region between D12S342 and D12S1658 suggested by the previously reported haplotypes in the two Danish families with bipolar affective disorder.

The class I metabotropic glutamate receptor antagonist, AIDA, improves short-term and impairs long-term memory in a spatial task for rats

Effects of the class I selective metabotropic glutamate receptor antagonist, 1-aminoindan-1,5-dicarboxylic acid (AIDA), on spatial procedural learning and episodic short-term memory of rats were investigated in an appetitively reinforced 3-choice delayed match-to-position task. First, an acute intraperitoneal injection of AIDA (2 mg/kg) was given 20 min before a single training session of 20 trials using repeated reward position in one alcove out of three. AIDA caused facilitated short-term acquisition within such a session compared to saline treated controls. Secondly, injections were given before each of ten sessions (48 h intervals) also using constant reward position. The results showed AIDA induced inhibition of procedural between-session acquisition. Finally, the use of reward positions in a non-repetitive but trial-specific version of the 3-choice test revealed a facilitating effect of AIDA on episodic short-term memory.

A haplotype-based study of lithium responding patients with bipolar affective disorder on the Faroe Islands

The Faroe Islands are a small group of islands in the North Atlantic Ocean, situated between Norway, Iceland and Scotland. The origin of the population is thought to be a mixture of Norwegian, Danish and British. The islands were populated at the same time as Iceland, i.e. around 1100 years ago, and the size of the population was around, and occasionally below, 4000 inhabitants until 1800, after which it increased to its present-day level of around 45,000. The population is descended from Scandinavian and British ancestors. Because of the low number of founders and small size for many centuries, the Faroese population is perhaps the most valuable European population for genetic mapping of complex disease genes. The present study searched for haplotype sharing on chromosome 18 among eight lithium responding patients with bipolar affective disorder related, on average, 6.2 generations ago, using 30 DNA markers. In order to obtain as homogeneous a sample as possible, strict inclusion criteria based on severity of phenotype, geography and treatment response, were applied. Evidence suggestive of increased haplotype sharing on the distal part of chromosome 18q23 in the region implicated by Freimer and co-workers was found. However, methods of genetic analysis which might provide a conclusive result are not yet available.

Hmong/medicine interactions: improving cross-cultural health care

BACKGROUND AND OBJECTIVES

There are now more than 100,000 Hmong (Southeast Asian) refugees in the United States. This study examined interactions between Hmong patients and their health care providers and identified specific factors that either enable or obstruct health care delivery.

METHODS

We used semistructured interview techniques to investigate patients' and providers' experiences, looking for attitudes, ideas, or behaviors that could be modified to improve health care delivery. Interviews with 23 Hmong patients, 18 health care providers, and six translators were audiotaped, transcribed, and analyzed by a multidisciplinary team. Methods included text analysis, theme identification, rank ordering, participant observation, immersion-crystallization, and open-ended discussion.

RESULTS

Hmong patients and their US-trained health care providers have different health belief systems. Both linguistic and cultural translation were seen as problematic. Additionally, an overwhelming number of patients identified kindness, caring, and a positive attitude as important provider characteristics. Providers noted difficulties in understanding Hmong conceptions of acute versus chronic diseases, illness prevention, and pain, both physical and psychological. Many respondents gave suggestions for improvement: 1) learn more about each other's cultures, 2) be patient, kind, and positive, 3) avoid negative statements or predictions, 4) improve translation quality, 5) explain medical terms using visual aids, 6) respect Hmong family-centered decision making, 7) increase the time allotted for translated clinical encounters, and 8) train Hmong health care providers.

CONCLUSIONS

Many basic issues in relations between clinicians and Hmong patients must be addressed to improve health care communication.

Characterization of cell-bound papain-soluble beta-lactamases in BRO-1 and BRO-2 producing strains of Moraxella (Branhamella) catarrhalis and Moraxella nonliquefaciens

In Moraxella (Branhamella) catarrhalis and Moraxella nonliquefaciens strains isolated from clinical specimens in the south of Sweden two variants of beta-lactamase were distinguished by isoelectric focusing (IEF). The BRO-1 (Ravasio type) enzyme was the most common in Branhamella catarrhalis, constituting about 90% of the beta-lactamase found in this species, while the BRO-2 enzyme (1908 type) was as common as BRO-1 in Moraxella nonliquefaciens. The determinants mediating the production of BRO-1 and BRO-2 were both transferable by conjugation. Cell-bound beta-lactamase from reference strains producing BRO-1 and BRO-2 could be solubilized by papain digestion. The isoelectric point of the solubilized enzymes differed distinctly between BRO-1 (pI 6.5) and BRO-2 (pI 6.9). The molecular species of BRO-1 and BRO-2 released by papain digestion were purified by affinity chromatography with phenylboronic acid agarose gel. They had identical molecular weights of approximately 28,000. Their kinetic constants were indistinguishable for a number of substrates and beta-lactamase inhibitors.

3T3-L1 adipocyte glucose transporter (HepG2 class): sequence and regulation of protein and mRNA expression by insulin, differentiation, and glucose starvation

A glucose transporter cDNA (GLUT) clone was isolated from mouse 3T3-L1 adipocytes and sequenced. The nucleotide and deduced amino acid sequences were, respectively, 95 and 99% homologous to those of the rat brain transporter. The mouse cDNA and a polyclonal antibody recognizing the corresponding in vitro translation product were used to compare changes in transporter mRNA and protein levels during differentiation, glucose starvation, and chronic insulin exposure of 3T3-L1 preadipocytes. The respective cellular content of transporter mRNA and protein were increased 6.6- and 7.8-fold during differentiation, and 3.8- and 2.5-fold from chronic insulin exposure of differentiated adipocytes. Glucose starvation increased transporter mRNA and protein levels 2.2- and 3.5-fold in undifferentiated preadipocytes and 1.8- and 3.1-fold in differentiated adipocytes. Starvation of undifferentiated cells completely converted the native transporter to an incompletely glycosylated form, while increasing basal transport rates 4.5-fold. Either full glycosylation is not required to produce a functionally active transporter, or starvation causes a unique predifferentiation induction of the normally absent "responsive" transporter. The changes in transporter protein expression elicited by differentiation were attributed primarily to increased rates of transporter synthesis, while the disproportionate changes in mRNA and protein expression from chronic insulin treatment and starvation suggested these conditions increase synthesis and decrease turnover rates in regulating transporter protein expression. Although chronic insulin exposure and glucose starvation each raised the expression of transporter protein greater than 3-fold and basal transport rates 2.5- to 4.5-fold, no significant increase in the insulin responsiveness of 3T3-L1 preadipocytes or differentiated adipocytes was observed. Thus, the changes in the transporter mRNA and protein expression observed in this study were most consistent with their being associated with the regulated expression of a basal or low level insulin-responsive transporter.

Plasmid-mediated beta-lactamase in Branhamella catarrhalis

The plasmid-mediated beta-lactamase in Branhamella catarrhalis (BRO-1), also occurring in Moraxella nonliquefaciens, differs from other known plasmid-mediated beta-lactamases in Gram-negative bacteria regarding substrate profile and isoelectric point. B. catarrhalis strains previously reported to produce beta-lactamases deviating from BRO-1 were tested, and the beta-lactamases did not differ significantly from BRO-1 in substrate profile, isoelectric point or relative substrate affinity index (RSAI). Further investigations of strains of various geographic origin should be undertaken. RSAI seems to be a useful tool for screening of beta-lactamases in B. catarrhalis since values for a large number of strains can easily be determined. The previously reported conjugational transfer of BRO-1 production within species B. catarrhalis and from M. nonliquefaciens to B. catarrhalis was confirmed. Four bands of extrachromosomal DNA were regularly detected by agarose gel electrophoresis in beta-lactamase-producing as well as in beta-lactamase-negative strains of B. catarrhalis and M. non-liquefaciens, provided that the excessive nuclease activity in the preparations was inhibited.

Transfer of beta-lactamase production in Branhamella catarrhalis

A beta-lactamase positive Branhamella catarrhalis strain, B.c. 002 PcR, is described. The strain has the ability to transfer beta-lactamase production. The strain was isolated from nasopharynx in an adult patient with long-standing laryngitis. It showed atypical colony morphology.