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D Curtis

Publications and source records attributed to D Curtis.

At least 91 records · Page 5Linked to original sources
PubMed1996

Linkage studies in bipolar affective disorder with markers on chromosome 21.

Straub et al. (1994: Nature Genet. 8. 291-296) have suggested that a susceptibility gene for bipolar affective disorder is located at chromosome 21q22.3, on the basis of linkage analysis in one large family. This result has been supported by Gurling et al. (1995: Nature Genet. 10, 8-9) who also found some evidence for linkage to this region under locus heterogeneity. In order to investigate the validity of these results and to estimate how broadly applicable they are, we performed a linkage study between bipolar affective disorder and two DNA markers (D21S171 and PFKL) from 21q22.3 using 60 bipolar pedigrees from three European centres and Brazil. The most positive result obtained was a maximised admixture lod score of 1.2 for the marker PFKI, under the assumption of locus heterogeneity, dominant transmission and a diagnostic classification which included recurrent unipolar depression. However, since lod scores obtained for both markers were substantially negative overall, we conclude that there is no common major gene for bipolar affective disorder at 21q22.3. It remains possible that a gene of major effect in this region operates in a minority of families.

Bipolar Disorder↗
PubMed1996

A linkage study of schizophrenia with DNA markers from chromosome 8p21-p22 in 25 multiplex families.

Two recent genome-wide searches for linkage (Lasseter et al., 1994; Moises et al., 1995) suggested that a susceptibility gene for schizophrenia might be located at chromosome 8p21-p22. We attempted to replicate these findings by performing a linkage study of schizophrenia with four DNA markers from this region using 25 multiply affected families. Neither the lod score method nor non-prametric extended sib-pair analysis yielded any evidence for linkage, even under the assumption of locus heterogeneity. We conclude that there is unlikely to be a major gene in the 8p21-p22 region which confers susceptibility to schizophrenia in our set of families. However we cannot exclude the possibility of a major gene present in other families, or of a susceptibility gene with a moderate but widespread effect which we cannot detect.

Autoradiography↗
PubMed1996

Identification of cis-acting sequences that control nanos RNA localization.

The generation of anterior-posterior polarity during development in Drosophila requires the localization of determinant molecules to the anterior and posterior poles of the embryo. Localization of the maternally synthesized nanos RNA to the posterior pole of the embryo is essential to provide a source for a gradient of Nanos protein that directs abdomen formation. nanos RNA localization occurs during oogenesis and requires the function of at least nine genes. cis-acting sequences that direct nanos RNA localization lie within the nanos 3'UTR. In this analysis, we have used nanos 3'UTR deletion mutants to define the localization signal more precisely. Our results indicate that the nanos RNA localization signal is large and complex and that targeting of nanos RNA may be achieved by the combined effects of multiple, partially independent sequences. This idea is supported by evolutionary conservation, both in sequence and in function, of the nanos 3'UTRs of Drosophila melanogaster and Drosophila virilis.

Animals↗
PubMed1996

Sigmund Freud.

Explore the source record for details and available documents.

History, 19th Century↗
PubMed1996

Effects of infection control procedures on the accuracy of a new mechanical torque wrench system for implant restorations.

Loosening of screw components for implant restorations has been attributed to insufficient tightening. The degree of tightening may be increased and more closely controlled by use of calibrated mechanical torque wrenches. The DynaTorq wrench system has been introduced to the market and consists of three individual wrenches with torque values of 10, 20, and 30 newton-centimeters (Ncm). This study evaluated the accuracy of the DynaTorq wrench system before and after steam autoclave and Chemiclave sterilization treatment. Before sterilization treatments, the wrenches demonstrated high accuracy and precision. Autoclaving resulted in increases in torque values for the 10 Ncm torque wrench compared with baseline measurements. Except for the effect of autoclaving on the 10 Ncm torque wrench, sterilization procedures did not adversely affect the accuracy of the DynaTorq torque wrench system.

Bone Screws↗
PubMed1996

Parvovirus B19 in HIV infection: a treatable cause of anemia.

We describe the case of an adult male patient with AIDS who presented with severe anemia and on investigation was found to have red cell aplasia due to parvovirus B19 infection. Bone marrow examination revealed absence of erythroid development and rare giant pronormoblasts. Repeated serological examinations revealed a low level of parvovirus IgM but no IgG. Viremia was demonstrated by electron microscopy and by the polymerase chain reaction (PCR). The patient's initial hemoglobin was 45 g/l and over a four month period he required twenty units of blood. He was treated with intravenous immunoglobulin (Intragam, CSL) at a dose of 400 mg/kg/day for five days. This led to an increase in his hemoglobin to 135 g/l. Parvovirus remained detectable by PCR but not by electron microscopy. Six months later the patient relapsed (Hb 65 g/l). Again he was transfused and treated with intravenous immunoglobulin for five days. His hemoglobin rose to 153 g/l and remained stable. He subsequently received maintenance treatment with 30 g of intagram once a month. We recommend that parvovirus be considered in any HIV infected patient with recurrent anemia.

Adult↗
PubMed1996

Linkage analysis and exclusion of regions of chromosomes 3 and 8 in Gilles de la Tourette syndrome following the identification of a balanced reciprocal translocation 46 XY, t(3:8)(p21.3 q24.1) in a case of Tourette syndrome.

Gilles de la Tourette syndrome (GTS) and related disorders such as chronic multiple tics and obsessive compulsive behaviour are likely to be genetically transmitted with a Mendelian autosomal dominant mode of transmission. Following our discovery of a patient with GTS who also carried a balanced translocation 46 XY, t(3:8) (p21.3 q24.1), a linkage study of several families was performed covering the areas on chromosomes 3 and 8 implicated by the cytogenetic abnormality in this unique GTS patient. A positive multipoint lod score of 2.9 was obtained on chromosome 3 with markers at the loci RAF1, THRB and D3S11. Subsequently, the genetic map of this region was improved and new polymorphic markers close to our original three markers were identified. With the new map the maximum two-point lod with any marker was reduced to 1.77 at RAF1, and the FASTMAP approximate multipoint lod excluded the likely region of the breakpoint. After constructing a somatic cell hybrid, the original three markers were mapped relative to the break point of the translocation and to other new markers. It was confirmed that the original markers were at least 20 cM away from the position of the break point. In addition, we traced further family members of our translocation GTS proband, and identified affected individuals who did not possess the translocation. We concluded that the translocation was not responsible for the GTS symptoms in our affected proband.

Chromosome Mapping↗
PubMed1996

Linkage study of the D5 dopamine receptor gene (DRD5) in multiplex Icelandic and English schizophrenia pedigrees.

OBJECTIVE: The authors investigated the possibility that genetic variation or mutation of the dopamine D5 receptor gene might modify susceptibility to schizophrenia. METHOD: Twenty-three Icelandic and English pedigrees containing multiple cases of schizophrenia were genotyped by using a highly informative microsatellite for the D5 dopamine receptor gene DRD5. RESULTS: By means of three different affection models, negative lod scores were obtained under assumptions of autosomal dominant and recessive inheritance. There was no evidence for locus heterogeneity. Nonparametric extended relative pair analysis also produced negative results. CONCLUSIONS: These data indicate that mutations of the D5 dopamine receptor gene are not a major cause of schizophrenia in these pedigrees. Because of the probable existence of locus heterogeneity, the D5 receptor gene may be of etiologic importance in other families with schizophrenia.

Base Sequence↗
PubMed1996

Lack of evidence for close linkage of the glutamate GluR6 receptor gene with schizophrenia.

OBJECTIVE: Previous research has consistently implicated genetic factors in the pathogenesis of schizophrenia. It has been hypothesized that an abnormality in glutamatergic function is of etiologic importance in schizophrenia, and therefore the glutamate receptor family of genes are potential susceptibility loci for schizophrenia. To test this hypothesis the authors sought to detect linkage between the GluR6 glutamate receptor gene and schizophrenia. METHOD: Twenty-three English and Icelandic families containing multiple cases of schizophrenia were genotyped with a microsatellite trinucleotide repeat polymorphism localized at the GluR6 glutamate receptor locus. Lod scores, model-free linkage analysis, and extended relative pair analysis were used to test for linkage. RESULTS: No statistically significant evidence of linkage between GluR6 and schizophrenia was found. CONCLUSIONS: The results do not support the hypothesis that GluR6 allelic variants provide a major gene contribution to the etiology of schizophrenia in a large proportion of these pedigrees.

Alleles↗
PubMed1996

Further tests for linkage of bipolar affective disorder to the tyrosine hydroxylase gene locus on chromosome 11p15 in a new series of multiplex British affective disorder pedigrees.

OBJECTIVE: This study was undertaken to confirm or refute previous reports that link bipolar affective disorder to polymorphic DNA markers at or near the gene for tyrosine hydroxylase. METHOD: A previous linkage analysis, which used a tetranucleotide repeat polymorphism at the tyrosine hydroxylase locus, of six Icelandic families was extended to include a new series of 17 multiply affected British families. RESULTS: Overall lod scores under the assumption of locus heterogeneity were between 1.20 and 1.40 at zero recombination with tyrosine hydroxylase, and these scores persisted across three affective disorder models. CONCLUSIONS: These results provide some support for linking affective disorder to this genetic region and suggest that additional linkage and association studies should be conducted to determine whether tyrosine hydroxylase or a nearby locus contributes to susceptibility to bipolar affective disorder in some families.

Alleles↗
PubMed1996

A genetic linkage study of the D2 dopamine receptor locus in heavy drinking and alcoholism.

BACKGROUND: Reports of an association between restriction fragment length polymorphisms (RFLPs) at the dopamine D2 receptor (DRD2) locus and alcoholism have suggested involvement of that locus in the aetiology of alcoholism. METHOD: Sib pair linkage analyses were conducted in families multiply affected by alcoholism, using both the Taql 'A' RFLP and a microsatellite repeat polymorphism at the DRD2 locus. RESULTS: The 'Identical By Descent' analysis provided significant evidence of an effect of the DRD2 locus on the liability to develop heavy drinking (P < 0.0016) and Research Diagnostic Criteria alcoholism (P < 0.0003) in the first sample of families studied. However, this result was explicable by the segregation of alleles in a single large sibship, and it was not replicated in a second sample of families. CONCLUSIONS: The results do not support linkage between the DRD2 locus and alcoholism in most of the families studied. It remains possible that this locus influences the predisposition to alcoholism in some families.

Alcoholism↗
PubMed1996

Genetic evidence for the neuronal nitric oxide synthase gene (NOS1) as a susceptibility locus for infantile pyloric stenosis.

The etiological role of the gene for neuronal nitric oxide synthase (NOS1) in infantile pyloric stenosis (PS) was investigated by analysis of two intragenic polymorphisms (NOS1a and NOS1b) in 27 families. There was significant overall transmission disequilibrium between PS and NOS1a (P = .006). Consideration of each allele independently revealed a highly significant tendency for allele 7 (210 bp) to be preferentially transmitted to the affected offspring (P = .0006). These observations suggest that NOS1 is a susceptibility locus for PS.

Alleles↗