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D Goldman

Publications and source records attributed to D Goldman.

At least 181 records · Page 10Linked to original sources
PubMed1996

Ocular retardation mouse caused by Chx10 homeobox null allele: impaired retinal progenitor proliferation and bipolar cell differentiation.

Ocular retardation (or) is a murine eye mutation causing microphthalmia, a thin hypocellular retina and optic nerve aplasia. Here we show that mice carrying the OrJ allele have a premature stop codon in the homeobox of the Chx10 gene, a gene expressed at high levels in uncommitted retinal progenitor cells and mature bipolar cells. No CHX10 protein was detectable in the retinal neuroepithelium of orJ homozygotes. The loss of CHX10 leads both to reduced proliferation of retinal progenitors and to a specific absence of differentiated bipolar cells. Other major retinal cell types were present and correctly positioned in the mutant retina, although rod outer segments were short and retinal lamination was incomplete. These results indicate that Chx10 is an essential component in the network of genes required for the development of the mammalian eye, with profound effects on retinal progenitor proliferation and bipolar cell specification or differentiation. off

Alleles↗
PubMed1996

Why mice drink.

Explore the source record for details and available documents.

Alcoholism↗
PubMed1996

The apportionment of dinucleotide repeat diversity in Native Americans and Europeans: a new approach to measuring gene identity reveals asymmetric patterns of divergence.

The purpose of this paper is to assess the extent of gene identity and differentiation at 33 dinucleotide repeat loci (377 total alleles) within and among three European and three Native American populations. In order to do this, we show that a maximum-likelihood method proposed for phylogenetic trees (Cavalli-Sforza and Piazza 1975) can be used to estimate gene identity (Nei 1987) with respect to any hierarchical structure. This method allows gene differentiation to be evaluated with respect to any internal node of a hierarchy. It also allows a generalization of F- and G-statistics to situations with unequal expected levels of differentiation. Our principal finding is that levels of genetic differentiation are unique to specific populations and levels of nesting. The populations of European origin show very little internal differentiation; moreover, their continental average is close to the total population defined by the aggregate of Europeans and Native Americans. By contrast, the Native American populations show moderate levels of internal differentiation, and a great distance between their continental average and the total. The results of analyses of subsets of loci that were selected to have high gene diversities in either Europeans or Native Americans closely parallel those from the total set of loci. This suggests that the principal results are unlikely to be caused by a European ascertainment bias in locus selection. In summary, our findings demonstrate that partitions of gene diversity into within- and between-populations components are heavily biased by the populations analyzed and the models fitted. Optimistically, however, more information is available to analyze population history and evolution by quantifying, as we have done, the uniqueness of patterns of differentiation.

Base Sequence↗
PubMed1996

DRD2 haplotypes containing the TaqI A1 allele: implications for alcoholism research.

In recent years, a possible role of the dopamine D2 receptor (DRD2) locus in the etiology of alcoholism has been the focus of considerable attention. The literature now contains a mix of association studies with positive and negative conclusions. Various methodological flaws undermine the claims in many of the studies that conclude a positive association exists between alcoholism and the DRD2*A1 allele at the Taql "A" site. Although the studies with negative findings have more often come from studies using better analytic methodology, satisfactory resolution of whether or not genetic variation at the DRD2 locus plays some role in the etiology of alcoholism is unlikely to come from additional studies of the kind conducted thus far; an approach enlightened by a more thorough understanding of the population genetics of DRD2 and the phylogenetic origins of the DRD2 alleles is one alternative. If genetic variation at the DRD2 locus affects susceptibility to alcoholism, then such variation has a mutational and evolutionary history that can be traced with the aid of the various genetic polymorphisms that have been identified at the DRD2 locus. In this study, a third Taql restriction fragment-length polymorphism at DRD2, the Taql "D" site, has been converted to polymerase chain reaction-based typing and its frequencies determined in 22 populations from around the world. Haplotypes defined by the polymorphisms at the Taql "B" and "A" sites, and the short tandem repeat polymorphism in intron 2 have been constructed and the diversity of haplotypes containing the DRD2*A1 allele examined for all 22 populations. The ancestral origins of the three Taql polymorphisms have also been determined by sequencing the homologous regions in other higher primates. Because A1-containing haplotypes in populations of European, Middle Eastern, and African origin show considerable diversity within and among populations, properly designed association studies in populations descended from those areas of the world need to use haplotypes, not a single allelic system, and need to use appropriate methods to compensate for the near impossibility of genetically matching unrelated control samples.

Alcoholism↗
PubMed1996

Lack of association between polymorphisms in the 5-HT2A receptor gene and the antipsychotic response to clozapine.

OBJECTIVE: The authors' goal was to determine whether either of two 5-HT2A receptor polymorphisms, 102-T/C and 452-His/Tyr, are associated with clozapine response. METHOD: Brief Psychiatric Rating Scale (BPRS) ratings were obtained in 70 patients with schizophrenia or schizoaffective disorder to determine their response to clozapine compared with a typical neuroleptic. Patients were genotyped with the polymerase chain reaction and restriction fragment length polymorphism analysis. RESULTS: Neither 102-T/C nor 452-His/Tyr was associated with clozapine response. There were no significant differences in BPRS scores among patients with different 5-HT2A genotypes at week 10 of clozapine administration. CONCLUSIONS: Allelic variation in the 5-HT2A gene is not associated with individual differences in clozapine response.

Adult↗
PubMed1996

Expression of inducible nitric oxide synthase in rat pulmonary Cryptococcus neoformans granulomas.

Rats, like humans, have extremely effective immune mechanisms for controlling pulmonary Cryptococcus neoformans infection. The mechanism(s) responsible for efficient immunity in rat experimental infection is unknown. Recently, induction of inducible nitric oxide synthase (iNOS) and nitric oxide (NO) have been implicated as an important microbicidal mechanism by which activated macrophages effect cytotoxicity against microbes. In this report, we investigated the expression of iNOS in rat pulmonary cryptococcosis. Localization and regulation of NO production was studied by immunohistochemistry for iNOS in conjunction with immunohistochemistry for cell markers, cytokines, and cryptococcal capsular polysaccharide. iNOS immunoreactivity was detected in macrophages, neutrophils, vascular endothelium, and respiratory epithelium. Double-immunolabeling studies revealed that the most prominent iNOS immunoreactivity was localized to epithelioid macrophages (CD11b/c+) within granulomas; CD4+ and CD8+ T cells were numerous around granulomas but did not express iNOS. iNOS immunoreactivity was detected in a selective population of epithelioid macrophages within some granulomas but not others. iNOS- granulomas were identical to iNOS+ granulomas with respect to morphology and immunohistochemical profiles. Macrophage iNOS immunoreactivity was detected 1 week after infection in one out of four rats and was strongly expressed in all rats at 2 weeks (in up to 50 percent of the granulomas) but declined considerably by 25 days. iNOS expression coincided with granuloma formation and preceded a decrease in lung fungal burden, suggesting an anticryptococcal role for NO. By double labeling, cytokines that have been shown to promote (interferon-gamma, granulocyte/macrophage colony-stimulating factor) and inhibit (transforming growth factor-beta) macrophage iNOS expression were detected around iNOS+ granuloma. iNOS immunoreactivity was expressed in selected neutrophils (1 and 2 weeks) and endothelial cells (1 and 2 weeks and 25 days) in the inflamed lung. Airway iNOS immunoreactivity was limited to the luminal border of rare bronchiolar epithelial cells. iNOS immunoreactivity was not detected in uninfected rats. The present study provides the first evidence for association of iNOS expression with protective cellular responses to cryptococcal infection in vivo.

Animals↗
PubMed1996

Serum complement determinations in patients with quiescent systemic lupus erythematosus.

OBJECTIVE: To determine whether complement component analyses during a period of inactive disease can define clinically important subgroups and predict morbidity in patients with systemic lupus erythematosus (SLE). METHODS: We identified 277 patients with SLE whose disease became clinically inactive at some point after diagnosis. Serum samples were obtained at that time and tested for total complement activity (CH100) and antigenic levels of C1q, C1r, C1s, C3 and C4. Results of complement determinations were correlated with demographic characteristics and clinical findings in the followup period (mean observation period 4.25 years). RESULTS: We identified 25 (9%) patients with multiple complement determinations below the normal range. 24 other patients (8.5%) had a very low level of a single complement component. The group with multiple complement determinations below the normal range was much more likely than the normocomplementemic SLE controls to progress to renal insufficiency. In other respects, complement component determinations were neither reflective nor predictive of clinical course. CONCLUSION: In this group of patients with inactive SLE, complement component analyses did not generally correlate with longterm outcome; however, multiple low complement component determinations during disease quiescence was associated with increased risk of renal insufficiency.

Autoantigens↗
PubMed1996

The association between the dopamine D4 receptor (D4DR) 16 amino acid repeat polymorphism and novelty seeking.

Ebstein and colleagues have recently reported a significant association between the 7-repeat allele of the dopamine D4 receptor (D4DR) 16 amino acid repeat polymorphism and the personality trait of Novelty Seeking (NS) in 124 Israeli subjects. This study, and another study conducted in the US (although with a different personality measure) that observed a similar association, have generated wide interest in the identification of the genes involved in personality variation. We have determined D4DR genotypes in two groups of Finnish subjects; 193 psychiatrically screened normal controls and 138 alcoholic offenders and assessed NS with the Tridimensional Personality Questionnaire (TPQ). In normals, we find no significant association between NS and the 7-repeat allele despite similar allele frequencies and the use of the same personality measure as Ebstein et al. The group of alcoholic offenders have significantly higher NS than normals, however we fail to replicate the previous association in this group and, in fact, find a significant association in the opposite direction as previously observed. These data suggest that D4DR may require re-evaluation as a candidate gene for personality variation.

Adult↗
PubMed1995

Antisense oligonucleotide inhibition of tryptophan hydroxylase activity in mouse brain.

To examine in vivo effectiveness of antisense oligonucleotides against tryptophan hydroxylase (TPH) mRNA, adult male swiss-NIH mice were implanted with in-dwelling cannula into the 4th ventricle and after recovery infused with either antisense oligonucleotide to TPH, scrambled control oligo or saline vehicle for four consecutive days. An additional group of animals bearing cannula were injected a single time i.p. with the TPH inhibitor para-chlorophenylalanine (PCPA; 300 mg/kg). All animals were sacrificed on the afternoon of the 4th day of treatment. TPH activity was measured by enzymatic assay and HPLC quantification of end-product synthesis. There was a significant decrease (> 50%) in TPH activity in both the PCPA-treated and antisense-oligo infused animals compared to either scrambled-oligo or saline-infused subjects (ANOVA; P < 0.05). There was no difference between saline and scrambled oligo-infusion. In a separate group of animals treated in the same way, behavioral tests were conducted on the afternoon of the 4th day. Two tests of anxiety, the hole-board apparatus and the elevated plus-maze, indicated some significant effects of PCPA treatment and/or antisense oligo-infusion but confounding effects due to alterations in locomotion could not be ruled out. However, tests on a rotorod apparatus indicated that antisense oligo-infused animals retained good balance and coordination in that their performance significantly improved on the second test, as did that of scrambled-oligo infused animals. In contrast, PCPA-treated animals did not improve, suggesting that locomotor performance had been impaired. These data support the notion that antisense oligo blockade may offer advantages over pharmacological manipulations of enzyme activity.

Analysis of Variance↗
PubMed1995

SSCP primer design based on single-strand DNA structure predicted by a DNA folding program.

To predict alterations in single-strand DNA mobility in non-denaturing electrophoretic gels, Zuker's RNA folding program was modified. Energy files utilized by the LRNA RNA folding algorithm were modified to emulate folding of single-strand DNA. Energy files were modified to disallow G-T base pairing. Stacking energies were corrected for DNA thermodynamics. Constraints on loop nucleotide sequences were removed. The LRNA RNA folding algorithm using the DNA fold energy files was applied to predict folding of PCR generated single-strand DNA molecules from polymorphic human ALDH2 and TPH alleles. The DNA-Fold version 1.0 program was used to design primers to create and abolish SSCP mobility shifts. Primers were made that add a 5' tag sequence or alter complementarity to an internal sequence. Differences in DNA secondary structure were assessed by SSCP analysis and compared to single-strand DNA secondary structure predictions. Results demonstrate that alterations in single-strand DNA conformation may be predicted using DNA-Fold 1.0.

Aldehyde Dehydrogenase↗
PubMed1995

Polymorphism and genetic mapping of the human oxytocin receptor gene on chromosome 3.

Centrally administered oxytocin has been reported to facilitate affiliative and social behaviours, in functional harmony with its well-known peripheral effects on uterine contraction and milk ejection. The biological effects of oxytocin could be perturbed by mutations occurring in the sequence of the oxytocin receptor gene, and it would be of interest to establish the position of this gene on the human linkage map. Therefore we identified a polymorphism at the human oxytocin receptor gene. A portion of the 3' untranslated region containing a 30 bp CA repeat was amplified by polymerase chain reaction (PCR), revealing a polymorphism with two alleles occurring with frequencies of 0.77 and 0.23 in a sample of Caucasian CEPH parents (n = 70). The CA repeat polymorphism we detected was used to map the the human oxytocin receptor to chromosome 3p25-3p26, in a region which contains several important genes, including loci for Von Hippel-Lindau disease (VHL) and renal cell carcinoma.

Alleles↗
PubMed1995

DRD4 dopamine receptor genotype and CSF monoamine metabolites in Finnish alcoholics and controls.

The DRD4 dopamine receptor is thus far unique among neurotransmitter receptors in having a highly polymorphic gene structure that has been reported to produce altered receptor functioning. These allelic variations are caused by a 48-bp segment in exon III of the coding region which may be repeated from 2-10 times. Varying the numbers of repeated segments changes the length, structure, and, possibly, the functional efficiency of the receptor, which makes this gene an intriguing candidate for variations in dopamine-related behaviors, such as alcoholism and drug abuse. Thus far, these DRD4 alleles have been investigated for association with schizophrenia, bipolar disorder, Parkinson's disease, and chronic alcoholism, and all have been largely negative for a direct association. We evaluated the DRD4 genotype in 226 Finish adult males, 113 of whom were alcoholics, many of the early onset type with features of impulsivity and antisocial traits. Genotype frequencies were compared to 113 Finnish controls who were free of alcohol abuse, substance abuse, and major mental illness. In 70 alcoholics and 20 controls, we measured CSF homovanillic acid (HVA), the major metabolite of dopamine, and 5-hydroxyindoleacetic acid (5-HIAA). No association was found between a particular DRD4 dopamine receptor allele and alcoholism. CSF concentrations of the monoamine metabolites showed no significant difference among the DRD4 genotypes. This study of the DRD4 dopamine receptor in alcoholics is the first to be conducted in a clinically and ethnically homogeneous population and to relate the DRD4 genotype to CSF monoamine concentrations. The results indicate that there is no association of the DRD4 receptor with alcoholism.

Adult↗
PubMed1995

Identification, expression, and pharmacology of a Cys23-Ser23 substitution in the human 5-HT2c receptor gene (HTR2C).

The function of brain serotonin-2C (5-HT2C) receptors, including behavioral and neurochemical responses to 5-HT2C agonist challenge, has been suggested to be abnormal in individuals with neuropsychiatric disorders. Thus, it is important to identify polymorphisms and functional variants within this gene. Using SSCP analysis, we identified a Cys23-Ser23 substitution (designated 5-HT2Ccys and 5-HT2Cser) in the first hydrophobic region of the human 5-HT2C receptor. Allele frequencies in unrelated Caucasians were 0.13 and 0.87 for 5-HT2Cser and 5-HT2Ccys, respectively. DNAs from informative CEPH families were typed for this polymorphism and analyzed with respect to 20 linked markers on the X chromosome. Linkage analysis placed the 5-HT2C receptor gene (HTR2C) on Xq24. To evaluate whether this amino acid substitution causes a variant function of this receptor, recombinant human 5-HT2Ccys and 5-HT2Cser receptors were expressed in Xenopus oocytes and tested for responses to 5-HT using electrophysiological techniques. Concentration-response curves for 5-HT were not significantly different in oocytes expressing either form of the receptor, suggesting that the 5-HT2Ccys and 5-HT2Cser receptor proteins may not differ in their responses to serotonin under baseline physiological conditions.

Animals↗
PubMed1995

Two naturally occurring amino acid substitutions in the human 5-HT1A receptor: glycine 22 to serine 22 and isoleucine 28 to valine 28.

The human 5-HT1A receptor was screened for naturally occurring mutations. The PCR product of the 5-HT1A receptor gene was digested with several restriction enzymes and evaluated by single-strand conformational polymorphism (SSCP) analysis. Comparison of the SSCP electrophoretic pattern with a restriction map of the 5-HT1A receptor allowed localization of the polymorphic sites facilitating their identification by sequence analysis. Two polymorphisms were identified in the human 5-HT1A receptor gene that altered amino acid composition. The polymorphisms encode amino acid substitutions in the 5-HT1A receptor of a glycine to serine at amino acid 22 and an isoleucine to valine at amino acid 28, respectively. Both polymorphisms alter the extracellular amino terminal domain of the 5-HT1A receptor. The polymorphic 5-HT1A alleles have been found in American and Finnish Caucasians and in native American Indians. This is the first report of a polymorphism in the human 5-HT1A receptor gene that alters the structure of the 5-HT1A receptor protein composition.

Alleles↗
PubMed1995

Mapping of the serotonin 5-HT1D beta autoreceptor gene on chromosome 6 and direct analysis for sequence variants.

Abnormal brain serotonin function may be characteristic of several neuropsychiatric disorders. Thus, it is important to identify polymorphic genes and screen for functional variants at loci coding for genes that control normal serotonin functions. 5-HT1D beta is a terminal serotonin autoreceptor which may play a role in regulating serotonin synthesis and release. Using an SSCP technique we screened for 5-HT1D beta coding sequence variants in psychiatrically interviewed populations, which included controls, alcoholics, and alcoholic arsonists and alcoholic violent offenders with low CSF concentrations of the main serotonin metabolite 5-HIAA. A common polymorphism was identified in the 5-HT1D beta gene with allele frequencies of 0.72 and 0.28. The SSCP variant was caused by a silent G to C substitution at nucleotide 861 of the coding region. This polymorphism could also be detected as a HincII RFLP of amplified DNA. DNAs from informative CEPH families were typed for the HincII RFLP and analyzed with respect to 20 linked markers on chromosome 6. Multipoint analysis placed the 5-HT1D beta receptor gene between markers D6S286 and D6S275. A maximum two-point lod score of 10.90 was obtained to D6S26, which had been previously localized on 6q14-15. Chromosomal aberrations involving this region have been previously shown to cause retinal anomalies, developmental delay, and abnormal brain development. This region also contains the gene for North Carolina-type macular dystrophy.

Alcoholism↗
PubMed1995

Electrical activity suppresses nicotinic acetylcholine receptor gamma subunit promoter activity.

Nicotinic acetylcholine receptors are pentameric, transmembrane, ligand-gated ion channels critical for neuromuscular signal transmission. Prior to innervation, the genes encoding these receptors are expressed in nuclei throughout the muscle fiber. Muscle innervation leads to a dramatic decrease in expression of these genes in extrasynaptic nuclei. This reduction in gene expression can be reversed by muscle denervation. The effects of denervation on receptor gene expression can be blocked by electrical stimulation of muscle using extracellular electrodes. The molecular mechanisms by which muscle electrical activity leads to altered patterns of nicotinic acetylcholine receptor gene expression are not well understood. Using an in vitro electrical stimulation paradigm to induce muscle activity, we have been able to mimic the effect of innervation on extrasynaptic acetylcholine receptor gene expression. We have found that a 93-bp region of 5'-flanking DNA, spanning nucleotides -150 to -57 relative to the transcription start site of the gamma subunit gene, is required for the suppression of gene expression in response to muscle activity. Sequences downstream of this region are transcriptionally active but are not responsive to muscle activity. However, these downstream sequences become responsive to muscle activity when placed under the control of the gamma subunit muscle-specific enhancer.

Animals↗