Dopamine D2 receptor gene and alcoholism among four aboriginal groups and Han in Taiwan

Previous studies examining the putative association between DRD2 TaqI A1 and alcoholism have produced conflicting results. Major critiques of such studies include potential confounding arising from population admixture by inappropriate selection of controls, failure to screen out substance abusers from controls, and the failure to assess the severity of alcoholics. To address these issues, we compared the allelic frequency of two polymorphisms of DRD2, TaqI A and NcoI, among severe alcoholics and their ethnically matched nonalcoholic controls within four major aboriginal groups and Han (Chinese) in Taiwan. The sample of alcoholics and controls examined for the five groups included 36 and 31 (Atayal), 24 and 23 (Ami), 58 and 58 (Bunun), 35 and 35 (Paiwan), and 50 and 66 (Han). A borderline association between TaqI A1 and alcoholism among the Ami (P = 0.08) and an association between NcoI N1 and alcoholism among Han (P = 0.01) were found. Results of haplotype analysis further confirm that the frequency of haplotype A1N1 was higher in alcoholics than in controls for the Ami (P = 0.01) and Han (P = 0.03). If controls with tobacco abuse were excluded from the analysis, the results remained unchanged. Severity in medical complications of alcohol dependence with withdrawal symptoms was not associated with higher prevalence of DRD2 TaqI A1 or NcoI N1 alleles. The absence of an association between DRD2 and alcoholism among the three aboriginal groups suggests either a higher rate of phenocopies among aboriginal alcoholics or genetic heterogeneity in the susceptibility to alcoholism.

Alcohol dehydrogenase and aldehyde dehydrogenase genotypes and alcoholism among Taiwanese aborigines

Previous population association studies have indicated that certain alleles of alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) genes may reduce the risk of alcoholism in Oriental populations. In this report we determined the genotypes for three genes, ADH2, ADH3, and ALDH2 among subjects with alcohol dependence (n = 159) and ethnically matched normal controls (n = 149) for the four largest aboriginal groups (Atayal, Ami, Bunun, and Paiwan) in Taiwan. The ethnicity matching used in this study was feasible because there are still few intergroup marriages between these aboriginal groups. On a group level, the rare frequencies of ALDH2*2, the inactive allele of ALDH2, among these aborigines may account partially for their vulnerability to alcohol use disorders. On an individual level, however, the genotypes controlling alcohol metabolism did not account for intragroup differences in vulnerability to alcoholism except in the case of ADH2 for the Ami ethnic group.

Septic arthritis of adult hip treated by total hip replacement--a case report

Septic arthritis is usually seen in children as an acute febrile illness induced by septicemia, local inoculation of a joint caused by trauma or adjacent osteomyelitis. It also occurs in adults particulary those with debilitating disease or sepsis at other sites. It normally happens in knee joints, but rarely in hip joints. A 65-year-old patient suffered from hip pain and febrile episodes intermittently for two months. Diagnostic hip aspiration was performed with 60 ml pus drained. The aspirate grew Staphylococcus aureus. Hip arthrotomy was performed with extensive debridement. Eighteen months later, this patient received total hip replacement and he has remained well for 8 years, with no evidence of infection or of implants loosening.

Reduced IL-10 secretion by CD4+ T lymphocytes expressing mutant cystic fibrosis transmembrane conductance regulator (CFTR)

Expression of the CFTR protein is thought to be physiologically important only in exocrine epithelial cells. However, chronic respiratory inflammation and infection remain unexplained phenomena in disease pathogenesis. Non-transformed, antigen-responsive CD4+ T cells cloned from healthy controls and CF patients homozygous or heterozygous for the delta F508 mutation transcribed CFTR mRNA and expressed immunoreactive cytoplasmic CFTR protein. T cell clones (TCC) from controls and CF patients displayed equivalent Ca(2+)-mediated Cl- current; however, TCC from patients with CF but not controls displayed defective cAMP-mediated Cl-current. Although CF-derived TCC preserved mitogen and antigen proliferative responses and specificity to tetanus toxoid epitopes, they selectively secreted approximately 45% less IL-10 compared with control TCC after activation with concanavalin A (Con A) (624 +/- 101 versus 1564 +/- 401 pg/ml per 10(6) cells, respectively; P = 0.04) or anti-CD3/phorbol ester (5148 +/- 1634 versus 11788 +/- 2390 pg/ml; P = 0.05). This difference was independent of atopy. Secretion of interferon-gamma, IL-2, and IL-4 was comparable in CF and control TCC after both forms of activation, while IL-5 was reduced in CF TCC following anti-CD3/phorbol myristate acetate (PMA) but not after Con A. We conclude that expression of mutant CFTR in human TCC is accompanied by ion channel dysfunction characteristic of the CF phenotype, and is accompanied by a reduction in IL-10 secretion after polyclonal activation. It is possible that disruption of IL-10-mediated anti-inflammatory homeostasis may contribute to early onset sustained inflammation in CF airways.

Endothelin-1 induces insulin resistance in conscious rats

Since endothelin-1 (ET-1) might regulate insulin secretion and glucose metabolism, we carried out experiments to study the effect of ET-1 in conscious rats by injecting ET-1 (0.5 or 1.0 microgram/100 g body weight, i.p.) and examining the plasma glucose (PG) and insulin (PI) concentrations and PG/PI ratios continuously for 3 hours after the injection. Compared to the saline controls, ET-1 increased PG and PG/ P1 ratios in a dose-dependent manner. Oral glucose tolerance test (OGTT) performed at 30 min after the injection showed that PG levels stayed significantly higher in rats preinjected with ET-1 than rats with saline injection, although the change in PI levels was not different. Simultaneous infusion of glucose and insulin to somatostatin-primed rats with ET-1 or saline injection resulted in significantly higher steady state plasma glucose (SSPG) levels and SSPG/PI ratios in rats injected with ET-1 than control rats with saline. These results unequivocally indicated that intraperitoneally administered ET-1 induces insulin resistance in conscious rats.

Association of monoamine oxidase A alleles with alcoholism among male Chinese in Taiwan

OBJECTIVE

The role of monoamine oxidase (MAO) in alcoholism was assessed by genetic association studies separately in five ethnic groups in Taiwan.

METHOD

Restriction fragment length polymorphisms (RFLP) and dinucleotide repeat polymorphisms (DNRP) were used to determine MAOA and MAOB alleles in male alcoholic patients and nonalcoholic comparison subjects among Han Chinese and four aboriginal groups.

RESULTS

Significant associations of alcohol dependence with MAOA alleles (RFLP and DNRP) were found among the Han Chinese, but not among the aboriginal groups. No significant association with MAOB DNRP alleles was found in any group.

CONCLUSIONS

Genetic heterogeneity may underlie alcoholism among different ethnic groups in Taiwan, and MAOA mutations may play a role in susceptibility to alcoholism among Han Chinese.

Alcohol-metabolising genes and alcoholism among Taiwanese Han men: independent effect of ADH2, ADH3 and ALDH2

BACKGROUND

Previous population association studies have indicated that certain alleles of alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) may reduce the risk of alcoholism in Asian populations. The association of ALDH2 and ADH2 with the development of alcoholism was found to be independent of each other and has been replicated in different Asian populations, while the effect of ADH3 is less studied.

METHOD

We genotyped the alcohol metabolism genes among Han men with alcohol dependence (n = 46) and their ethnically matched normal controls (n = 63) in Taiwan. Multiple logistic regression was then applied to assess the contribution of ADH3 to alcoholism by controlling the effect of ALDH2 and ADH2.

RESULTS

The results of multivariate analyses demonstrated that the odds ratios for an increment of one allele of ADH2*1, ADH3*2 and ALDH2*1 in the development of alcoholism were 4.18, 3.82, and 6.89, respectively.

CONCLUSIONS

These findings clearly indicate that all three alcohol-metabolising genes contribute to susceptibility to alcoholism.

Mutational analysis of the human MAOA gene

The monoamine oxidases (MAO-A and MAO-B) are the enzymes primarily responsible for the degradation of amine neurotransmitters, such as dopamine, norepinephrine, and serotonin. Wide variations in activity of these isozymes have been reported in control humans. The MAOA and MAOB genes are located next to each other in the p11.3-11.4 region of the human X chromosome. Our recent documentation of an MAO-A-deficiency state, apparently associated with impulsive aggressive behavior in males, has focused attention of genetic variations in the MAOA gene. In the present study variations in the coding sequence of the MAOA gene were evaluated by RT-PCR, SSCP, and sequencing a mRNA or genomic DNA in 40 control males with > 100-fold variations of MAO-A activity, as measured in cultured skin fibroblasts. Remarkable conservation of the coding sequence was found with only 5 polymorphisms observed. All but one of these were in the third codon position and thus did not alter the deduced amino acid sequence. The one amino acid alteration observed, lys --> arg, was neutral and should not affect the structure of the protein. This study demonstrates high conservation of coding sequence in the human MAOA gene in control males, and provides primer sets which can be used to search genomic DNA for mutations in this gene in males with neuropsychiatric conditions.

Activation of CFTR chloride current by nitric oxide in human T lymphocytes

Nitric oxide, which is produced by cytokine-activated mononuclear cells, is thought to play an important role in inflammation and immunity. While the function of nitric oxide as a direct cytotoxic effector molecule is well established, its function as a transducer molecule in immune cells is not. By use of whole-cell patch clamp recordings, we show that nitric oxide activates cystic fibrosis transmembrane conductance regulator CI- currents in normal human cloned T cells by a cGMP-dependent mechanism. This pathway is defective in cystic fibrosis-derived human cloned T cells. These findings not only delineate a novel transduction mechanism for nitric oxide but also support the hypothesis that an intrinsic immune defect may exist in cystic fibrosis.

Organization of the human monoamine oxidase genes and long-range physical mapping around them

A 265-kb yeast artificial chromosome containing sequences for human monoamine oxidase A and B (MAO-A and MAO-B) genes has been characterized. These two genes are localized within a region of about 240 kb and are arranged in a tail-to-tail configuration, with the 3' coding sequences separated by about 50 kb. A region about 2.5 Mb around the MAO loci was mapped by pulsed-field gel electrophoresis (PFGE). Comparisons between the restriction maps derived from the YAC and the long-range map derived from genomic digestions were in general agreement. The important features identified include a CpG island at the 5' end of the MAO-A and MAO-B genes, respectively. The combined information supports the order of markers within this region to be DXS77-DXS7-MAOA-MAOB.

RFLP for human DBH (dopamine beta-hydroxylase)

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Biochemistry and genetics of monoamine oxidase

This chapter reviews the two mitochondrial flavin containing isozymes of monoamine oxidase. Section 1, "Biochemistry" discusses assays, substrates and inhibitors, phylogenic and tissue distribution, interactions with lipids, nutritional studies, protein structure, kinetic and chemical mechanistic proposals, and biosynthesis. Section 2, "Inheritance" discusses possible genes involved in expression, genetic studies of platelet MAO-B and fibroblast MAO-A, and chromosomal location. Section 3, "Molecular Genetics" reviews the cloning of their cDNAs, their intra- and interspecies homology and structural inferences made from deduced amino acid sequences. Section 4, "Regulation" gives an overview of levels in development and aging, and effect of drugs. The final section 5, "Role in Human Disease" discusses physiological function and effects of altered levels in humans and animal models including complete absence due to a submicroscopic chromosomal deletion in several human patients.

Pseudomonas hyperimmune globulin passive immunotherapy for pulmonary exacerbations in cystic fibrosis

We studied the effect of an intravenously administered gamma globulin [Ps-ivIG] enriched fivefold over conventional ivIG for Pseudomonas aeruginosa lipopolysaccharide [PA LPS] antibodies on ten patients with cystic fibrosis [CF] aged 19-32 years during hospitalization for pulmonary deterioration. All were colonized with greater than or equal to 1 PA phenotype resistant to all antibiotics at the time of admission and they received 500 mg/kg Ps-ivIG intravenously as a single dose in addition to conventional treatment, including antibiotics and chest physiotherapy. No adverse effects occurred. Circulating immune complexes and complement levels remained unchanged from baseline. Serum levels of anti-PA LPS IgG, as measured by ELISA for eight PA LPS immunotypes, increased to 244 +/- 65% (mean +/- SE) of baseline levels 1 hour post-infusion (P less than 0.01), remained significantly elevated during a mean hospital stay of 17 days, and returned to near baseline by follow-up 4 weeks after hospital discharge. Plasma half-life and clearance values were similar to those of other subjects receiving conventional ivIG. Sputum PA density declined from 3.0 to 1.2 x 10(8) cfu/mL 1 week post-infusion (P approximately equal to 0.05), and returned to baseline at follow-up. Serum anti-PA opsonic activity increased after infusion (P less than 0.01), but returned to baseline by 72 hours. Clinical scores improved from admission to discharge (P less than 0.005) without decline at follow-up. Forced vital capacity [FVC] and forced expiratory volume in one second [FEV1] increased from admission to discharge (P less than 0.01 and P less than 0.05, respectively) without decline at follow-up. Using autologous historical control data, standard hospital therapy without Ps-ivIG resulted in no improvement in FVC or FEV1, and a subsequent decline in these parameters (P less than 0.05 for each) during a similar follow-up period. This occurred despite the fact that half the patients did not have antibiotic-resistant PA on the control admission. We conclude that Ps-ivIG is a safe adjunctive therapy for pulmonary exacerbations in moderately ill cystic fibrosis patients colonized with resistant PA, and may be associated with both greater and more prolonged improvement in pulmonary function than standard therapy alone.

Nonopsonic antibodies in cystic fibrosis. Pseudomonas aeruginosa lipopolysaccharide-specific immunoglobulin G antibodies from infected patient sera inhibit neutrophil oxidative responses

Antibody opsonins from cystic fibrosis (CF) patients were investigated using nonmucoid and mucoid lipopolysaccharide (LPS) immunotype 1 Pseudomonas aeruginosa as bacterial ligands and PMN phagocytes. CF sera were compared to normal sera, polyvalent PA LPS hyperimmune globulin, and isotype switch variant monoclonal antibodies (MAbs) specific for type 1 PA LPS. Sera from PA-infected CF patients (CF PA+) had elevated levels of PA LPS and alginate IgG antibodies and promoted significantly greater antibody-dependent PMN chemiluminescence responses than sera from uninfected CF patients (CF PA-) or normal human sera (NHS). After adjustment for autologous IgG PA LPS antibody content, however, CF PA+ sera had less antibody-dependent opsonic activity than sera from CF PA- patients (P less than 0.025) or NHS (P less than 0.0025), suggesting qualitative opsonic defects of IgG PA LPS antibodies in CF PA+ sera. Antigen-specific immunoprecipitation of PA LPS antibodies enhanced opsonization by 40% of CF PA+ sera while uniformly reducing that from CF PA- sera (P less than 0.01), indicating LPS-specific nonopsonic antibodies in some CF PA+ sera. Alginate antibodies were not critical opsonins in most uninfected CF patient sera. PA LPS IgG antibodies isolated by immunoaffinity chromatography from NHS, hyperimmune globulin, and CF PA- sources were opsonic and had greater activity at equal antigen-binding concentration than identical antibodies isolated from infected CF patients (P less than 0.01-0.05); the majority of isolates from CF PA+ sera did not promote PMN oxidative responses above nonopsonic baseline. A potential isotypic basis for these findings was supported by differences in PMN responses to PA opsonized with MAbs of identical specificity but differing isotypes. PA LPS-specific IgG antibodies inhibiting PMN oxidative responses in infected patient sera demonstrate antigen-specific immunomodulation of host responses by chronic bacterial parasitism in CF, which may play a role in the pathophysiology of lung disease.

Localization of human monoamine oxidase-A gene to Xp11.23-11.4 by in situ hybridization: implications for Norrie disease

A cDNA for the neurotransmitter-degrading enzyme monoamine oxidase-A (MAO-A) has been assigned by in situ hybridization to the human X chromosome and subregionally localized to Xp11.23-11.4. As restriction fragments detected by this probe are deleted in some patients with Norrie disease, this assignment provides confirmation of the localization of the disease.

The primary structure of bovine monoamine oxidase type A. Comparison with peptide sequences of bovine monoamine oxidase type B and other flavoenzymes

We have isolated cDNA clones believed to encompass the full-length coding sequences for a subunit of bovine monoamine oxidase type A (MAO-A). The clones code for an apoprotein of 527 amino acid residues corresponding to a molecular mass of 59,806 Da. The inferred protein sequences show an overall similarity of 68% with partial amino acid sequences of bovine type B MAO (about 41% of the total sequence), as well as a greater similarity (greater than 90%) with some regions including that for the published sequence of the flavin-binding region. Sequence comparisons indicate that these two forms of MAO are encoded by distinct genes. Comparison of this sequence with other flavoenzymes showed similarity with regions associated with non-covalent flavin-binding sites. Analysis of mRNAs coding for MAO enzymes showed a heterogeneity of transcripts consistent with several different forms of monoamine oxidase.

Monoamine oxidase deficiency in males with an X chromosome deletion

Mapping of the human MAOA gene to chromosomal region Xp21-p11 prompted our study of two affected males in a family previously reported to have Norrie disease resulting from a submicroscopic deletion in this chromosomal region. In this investigation we demonstrate in these cousins deletion of the MAOA gene, undetectable levels of MAO-A and MAO-B activities in their fibroblasts and platelets, respectively, loss of mRNA for MAO-A in fibroblasts, and substantial alterations in urinary catecholamine metabolites. The present study documents that a marked deficiency of MAO activity is compatible with life and that genes for MAO-A and MAO-B are near each other in this Xp chromosomal region. Some of the clinical features of these MAO deletion patients may help to identify X-linked MAO deficiency diseases in humans.

Structural features of human monoamine oxidase A elucidated from cDNA and peptide sequences

Monoamine oxidase (MAO), an important enzyme for the degradation of amine neurotransmitters, has been implicated in neuropsychiatric illness. The amino acid sequence for one form of the enzyme, MAO-A, has been deduced from human cDNA clones and verified against proteolytic peptides. The covalent binding site for the flavin adenine dinucleotide (FAD) cofactor is near the C-terminal region. The presence of features characteristic of the ADP-binding fold suggests that the N-terminal region is also involved in the binding of FAD. These cDNAs should facilitate the study of the structure, function, and intracellular targeting of MAO, as well as the analysis of its expression in normal and pathological states.

Human monoamine oxidase gene (MAOA): chromosome position (Xp21-p11) and DNA polymorphism

An essentially full-length cDNA clone for the human enzyme monoamine oxidase type A (MAO-A) has been used to determine the chromosomal location of a gene encoding it. This enzyme is important in the degradative metabolism of biogenic amines throughout the body and is located in the outer mitochondrial membrane of many cell types. Southern blot analysis of PstI-digested human DNA revealed multiple fragments that hybridized to this probe. Using rodent-human somatic cell hybrids containing all or part of the human X chromosome, we have mapped these fragments to the region Xp21-p11. A restriction fragment length polymorphism (RFLP) for this MAOA gene was identified and used to evaluate linkage distances between this locus and several other loci on Xp. The MAOA locus lies between DXS14 and OTC, about 29 cM from the former.

Altered antibody isotype in cystic fibrosis: impaired natural antibody response to polysaccharide antigens

Patients with cystic fibrosis (CF) have impaired natural (preinfection) IgG2 antibody responses to Pseudomonas aeruginosa lipopolysaccharide. To investigate the basis for this defect, we measured natural IgG and IgG1-4 antibody levels to Haemophilus influenzae type b polyribophosphate (PRP) and tetanus toxoid by enzyme-linked immunosorbent assay in 24 adult CF patients and 20 normal controls. Immunoglobulin heavy- and light-chain allotypes were determined on 146 Caucasian CF patients and 96 controls. The tetanus toxoid-specific IgG response was predominantly IgG1. CF and control subjects had similar IgG and IgG1 antibody levels. The PRP-specific IgG response was predominantly IgG2. In contrast to tetanus toxoid results, CF patients had lower geometric mean level of PRP-specific IgG compared to normal controls (p = 0.0036). ELISA results were confirmed by liquid-phase 3H-PRP-binding assay: CF patients had a geometric mean serum antibody level of 395 versus 922 ng/ml in controls (p = 0.0044). PRP-specific IgG2 levels were also depressed in CF patients (p = 0.03). CF patients had a lower prevalence of the A2m(2) allotype than the local racially matched control sample (p less than 0.025). Other allotype prevalences including G2m(n) and Km(1) were similar. Impaired IgG2 antibody responses to microbial polysaccharide surface antigens in CF patients might predispose them to persistent endobronchial infection and lead to production of nonopsonizing isotype responses. The potential role of A2m(2), coded for in the H chain locus on chromosome 14, is unknown, but could be related to mucosal IgA2 antibody responses.

Performance characteristics of immunoenzymatic allergosorbent testing for total and specific immunoglobulin E

Paper disc-based solid phase radioimmunoassays are widely used in vitro diagnostic test kits for measuring total IgE (Phadebas PRIST) and specific IgE antibodies (RAST). Recently, these kits have been modified by the substitution of an enzyme-linked immunosorbent assay detection system (Phadezym PRIST/RAST). We studied the performance characteristics of Phadezym PRIST and RAST kits. Phadezym PRIST was sensitive to 0.5 IU/mL IgE. Reproducibility was excellent in the range of 5 to 200 IU/mL IgE and adequate in the range of 5 to 1000 IU/mL using 1:10 serum dilutions (average inter-assay coefficient of variation = 19%). Phadezym RAST was specific, but sensitivity was limited by absorbances in the RAST class 1/0 range indistinguishable from background values. Average inter-assay coefficient of variation was 29% for the semi-quantitative 'Phadezym RAST Unit' (PRU) reporting system. We modified the test kit procedure by disc incubations in microtiter plate wells with rotational agitation and use of ELISA-dedicated spectrophotometer and computer software. These microplate accelerated computerized assays ('MacPRIST' and 'MacRAST') were shown to perform similarly to the conventional Phadezym procedures with advantages in speed, ease, and handling of data.