Tobacco, alcohol intake, and diet in relation to adenocarcinoma of the esophagus and gastric cardia

Little is known about the etiology of adenocarcinoma of the distal esophagus/cardia, a cancer which has increased in incidence in the United States over the last two decades. We analyzed data on smoking, alcohol use, dietary intake, and other factors obtained from 173 hospitalized males with adenocarcinoma of the distal esophagus/cardia (cases) and 4,544 hospitalized males with diseases not related to smoking and of other organ systems than the gastrointestinal tract (controls). Cases of squamous cell carcinoma of the esophagus (n = 136) and adenocarcinoma of the distal stomach (n = 122) were included as separate case groups. All subjects were interviewed in 28 hospitals in eight cities in the US between 1981 and 1990. After adjustment for covariates, the odds ratio (OR) for adenocarcinoma of the distal esophagus/cardia for current smokers was 2.3 (95 percent confidence interval [CI] = 1.4-3.9) and that for ex-smokers was 1.9 (CI = 1.2-3.0) relative to never-smokers. The OR for drinkers of four or more ounces of whiskey-equivalents of alcohol per day (relative to those consuming less than one drink per week) was 2.3 (CI = 1.3-4.3). Intakes of total fat and vitamin A from animal sources were significant risk factors and fiber intake was associated inversely with adenocarcinoma of the distal esophagus/cardia. Although the number of female cases of adenocarcinoma of the distal esophagus/cardia was small (n = 21), significant associations were observed for smoking and alcohol.

Association of nonmelanoma skin cancer and actinic keratosis with cumulative solar ultraviolet exposure in Maryland watermen

To establish the relationship between ultraviolet-B radiation and squamous cell carcinoma (SCC), basal cell carcinoma (BCC), and actinic keratosis (AK), a cross-sectional prevalence survey was performed in a sample of 808 white, male watermen 30 years of age and older residing in the Eastern Shore of Maryland. A measure of personal cumulative ultraviolet-B exposure was determined for each subject from data collected through interviews and field and laboratory measurements. A personal interview elicited skin type, medication history, and other factors. Clinical diagnoses and histologic confirmation were done for current and previously removed skin tumors. The ratio of subjects with SCC to subjects with BCC was approximately 1:1; however, the ratio of BCC to SCC was 1.25:1 because BCC cases were more prone to multiple lesions. Watermen with SCC or AK but not BCC had higher average annual ultraviolet-B doses than age-matched controls. This was particularly marked in watermen younger than 60 years of age. Logistic regression showed that an older age, childhood freckling, and blue eyes significantly increased the risk of the development of all three types of skin tumor. Ease of sunburning was associated with BCC and AK, but not with SCC. Watermen in the upper quartile of cumulative ultraviolet-B exposure had a 2.5 times higher risk for the development of SCC when compared with the lower 3 quartiles. This suggests that high levels of ultraviolet-B exposure are important in SCC occurrence. The risk of AK developing was 1.5 times higher for those whose cumulative ultraviolet-B exposure exceeded the median. The relationship of BCC to cumulative ultraviolet-B exposure was not clear and this suggests that different etiologic mechanisms operate for SCC and BCC.

Alcohol consumption and withdrawal in new-onset seizures

We studied alcohol use before the onset of a first seizure in 308 patients with seizures and 294 controls. The risk of seizures increased with increasing current alcohol use. For unprovoked seizures (i.e., seizures occurring without an antecedent event, such as a recent stroke), the adjusted odds ratios rose from 3-fold at intakes of 51 to 100 g of ethanol per day (95 percent confidence limits, 1.3 and 6.3), to 8-fold at 101 to 200 g per day (95 percent confidence limits, 3.3 and 18.7), and to almost 20-fold at 201 to 300 g per day (95 percent confidence limits, 6.1 and 6.2). For provoked seizures, the odds ratios were lower and statistically significant only above 200 g per day (odds ratio, 10.1; 95 percent confidence limits, 2.3 and 43.8 at 201 to 300 g per day; odds ratio, 7.4; 95 percent confidence limits, 1.8 and 30.5 above 300 g per day). Among ex-drinkers (abstention greater than or equal to 1 year), no increased risk was detected. Alcohol withdrawal was not associated with the onset of seizures in this study; 16 percent of first seizures in drinkers fell outside the conventionally defined withdrawal period, and the remainder exhibited a seemingly random timing after the last drink. We conclude that the relation of seizures to alcohol use is dose dependent and appears to be causal, and that seizures can be interpreted as a disorder induced by the ingestion of alcohol, independently of alcohol withdrawal.

Reduction of malodor by oral cleansing procedures

Organoleptic and gas chromatographic methods were employed to establish the threshold of odor objectionability of methylmercaptan and hydrogen sulfide and to assess the relative effectiveness of different oral hygiene measures to reduce the malodor to acceptable levels. The study showed that methylmercaptan and hydrogen sulfide concentrations below 0.5 ng. and 1.5 ng., respectively, are considered nonobjectionable. Gas chromatographic analyses indicate that these concentrations were exceeded in the early morning mouth air samples of approximately 50 per cent of the adult population studied. In these instances, methylmercaptan and hydrogen sulfide occurred in sufficiently high concentrations to account for the malodor. Brushing studies suggest that the early morning malodor arising from the oral cavity can be controlled by proper oral hygiene. The tongue was the major source of both offending compounds in the persons studied. Methods that involved cleansing of the dorsoposterior surface of the tongue caused the most pronounced reductions of both compounds. Since methylmercaptan was found to be more objectionable and to exhibit a lower threshold of objectionability, it was more difficult to reduce to acceptable levels.

A mixture model with random-effects components for clustering correlated gene-expression profiles

MOTIVATION

The clustering of gene profiles across some experimental conditions of interest contributes significantly to the elucidation of unknown gene function, the validation of gene discoveries and the interpretation of biological processes. However, this clustering problem is not straightforward as the profiles of the genes are not all independently distributed and the expression levels may have been obtained from an experimental design involving replicated arrays. Ignoring the dependence between the gene profiles and the structure of the replicated data can result in important sources of variability in the experiments being overlooked in the analysis, with the consequent possibility of misleading inferences being made. We propose a random-effects model that provides a unified approach to the clustering of genes with correlated expression levels measured in a wide variety of experimental situations. Our model is an extension of the normal mixture model to account for the correlations between the gene profiles and to enable covariate information to be incorporated into the clustering process. Hence the model is applicable to longitudinal studies with or without replication, for example, time-course experiments by using time as a covariate, and to cross-sectional experiments by using categorical covariates to represent the different experimental classes.

RESULTS

We show that our random-effects model can be fitted by maximum likelihood via the EM algorithm for which the E(expectation)and M(maximization) steps can be implemented in closed form. Hence our model can be fitted deterministically without the need for time-consuming Monte Carlo approximations. The effectiveness of our model-based procedure for the clustering of correlated gene profiles is demonstrated on three real datasets, representing typical microarray experimental designs, covering time-course, repeated-measurement and cross-sectional data. In these examples, relevant clusters of the genes are obtained, which are supported by existing gene-function annotation. A synthetic dataset is considered too.

AVAILABILITY

A Fortran program blue called EMMIX-WIRE (EM-based MIXture analysis WIth Random Effects) is available on request from the corresponding author.

Methionine intolerance: a possible risk factor for coronary artery disease

Homocystinuria, an inherited disorder associated with premature atherosclerosis, represents a severe form of methionine intolerance. To analyze the importance of milder forms of methionine intolerance in the genesis of vascular disease, the relation between provokable methionine intolerance and coronary artery disease was investigated. In a group of 138 men, aged 31 to 65 years (mean 53), referred for cardiac catheterization, plasma homocystine was measured before and 6 hours after an oral l-methionine load (0.1 g/kg). Thirty-nine subjects found to have normal coronary arteries had a mean post-load plasma homocystine level of 0.59 +/- 0.37 mumol/liter. A criterion at the 95th percentile (1.64 SD above the mean) was selected and applied to the remaining 99 subjects with coronary artery disease (0.70 +/- 0.68 mumol/liter). Sixteen (16%) of 99 subjects with coronary artery disease exceeded this level as compared with 1 (2%) of 39 subjects without coronary artery disease (p less than 0.04). The risk of coronary artery disease in men with provokable methionine intolerance was increased sevenfold as estimated by the odds ratio. By correlation matrix and multivariate regression analyses, provokable homocystinemia was predictive of coronary artery disease and was independent of tobacco smoking, hypertension, diabetes mellitus, serum cholesterol and age. It is proposed that men with mild methionine intolerance exposed to the high methionine content of the Western diet may develop intermittent homocystinemia and thus may be at greater risk for the development of coronary artery disease.

Subtypes of ischemic stroke. A hospital-based stroke registry in Taiwan (SCAN-IV)

BACKGROUND AND PURPOSE

To better understand the clinical pattern and further elucidate the risk factors and outcome in different subtypes of cerebral infarction (CI) of the Chinese in Taiwan, we analyzed the National Taiwan University Hospital Stroke Registry in 1995 and performed an ethnic comparison with similar data banks.

METHODS

From the National Taiwan University Hospital Stroke Registry in 1995, 676 patients (383 men and 293 women; mean age, 64.9 years; SD, 13.8 years; range, 1 to 98 years) with CI were recruited for this analysis. CI was classified into five subtypes based on clinical manifestations, ultrasonographic studies, and neuroimaging findings: large-artery atherosclerosis, lacunae, cardioembolism, other less common determined causes, and undetermined cause. Vascular risk factors, extracranial carotid artery atherosclerosis, and 30-day case-fatality rates were investigated in each subtype of CI.

RESULTS

Of all CI patients, 17%, 29%, 20%, 6%, and 29% were classified as large-artery atherosclerosis, lacunae, cardioembolism, other determined causes, and undetermined cause subtypes, respectively. The present results were compared with those from eight similar Western stroke registries. The relative incidence of lacunar CI in Chinese patients was more common, but large-artery atherosclerotic CI was less common than in whites. Hypertension was frequently seen in CI patients, especially in those with lacunae (85%) and large-artery atherosclerosis (69%). Patients with cardioembolism had a higher percentage of atrial fibrillation (69%), left ventricular hypertrophy, and ischemic heart disease than the other patients. Patients with large-artery atherosclerosis had more vascular risk factors, such as hypertension, diabetes mellitus, smoking, and carotid stenosis. Cardioembolic patients had higher case-fatality rates than other CI patients. Of the cardioembolic patients, 17.3% and 21.8% died within 30 days and during hospitalization, respectively.

CONCLUSIONS

The proportion of CI subtypes varied in different stroke registries. This may be partly due to applied classification criteria and racial-ethnic differences. Awareness of the risk factors and outcome in each subtype of stroke may afford further insights into the surveillance and treatment of cerebrovascular disease.

Lactate metabolism by Veillonella parvula

A strain of Veillonella parvula M4, which grows readily in lactate broth without a requirement for carbon dioxide, has been isolated from the oral cavity. Anaerobic, washed cells of this organism fermented sodium lactate to the following products (moles/100 moles of lactate): propionate, 66; acetate, 40; carbon dioxide, 40; and hydrogen, 14. Cells grew readily in tryptone-yeast extract broth with pyruvate, oxaloacetate, malate, and fumarate, but poorly with succinate. The fermentation of pyruvate, oxaloacetate, or lactate plus oxaloacetate by washed cells resulted in the formation of propionate and acetate in ratios significantly lower than those observed with lactate as the sole carbon source. This was primarily due to increased acetate production. Cell-free extracts were unable to degrade lactate but metabolized lactate in the presence of oxaloacetate, indicating the presence of malic-lactic transhydrogenase in this organism. Lactic dehydrogenase activity was not observed. Evidence is presented for oxaloacetate decarboxylase and malic dehydrogenase activities in extracts.

Allergic contact dermatitis to nickel: bioavailability from consumer products and provocation threshold

Twelve subjects sensitive to nickel underwent patch testing with serial dilutions of nickel sulfate in petrolatum and in water. The provocation threshold (the lowest amount of nickel producing a reaction) varied from 5.2 mg (2.5%) to 0.47 microgram (0.01%) when tested in petrolatum. The provocation threshold was higher with aqueous solutions. The lowest provocation threshold in a statistically significant number of individuals was 1.5 micrograms. Nickel bioavailability from dermatitis-inducing earrings and a necklace was determined by immersing them in plasma, normal saline solution, and synthetic sweat at different pH values over 7 days. Nickel leaching under these conditions exceeded the provocation threshold 1.4- to 93-fold, depending on object and solution. The time course varied with solution. After leaching, surface nickel was measured by the action of dilute nitric acid and total nickel was determined by complete dissolution in aqua regia. Nickel was more bioavailable from earrings than from the necklace, presumably reflecting different metallurgy. Plasma was the most effective solution for removing available nickel from earrings, a possible explanation for the frequent induction of sensitization by ear piercing. Comparison of provocation threshold and leaching results may help determine risks from consumer products.

Illicit drug use and the risk of new-onset seizures

The authors studied the use of heroin, marijuana, and cocaine before the onset of a first seizure in 308 patients with seizures and 294 controls at Harlem Hospital Center, New York City, between 1981 and 1984. Heroin use, both past and present, appeared to be a risk factor for all first seizures (adjusted odds ratio = 2.80, 95% confidence interval (CI) 1.53-5.74). For unprovoked seizures, the adjusted odds ratio was 2.58 (95% CI 1.36-4.90) for ever heroin use and 4.70 (95% CI 0.86-25.78) for heroin use within 24 hours of hospitalization. For provoked seizures, respective adjusted odds ratios were 3.65 (95% CI 1.54-8.65) and 27.74 (95% CI 3.57-215.52). Marijuana use appeared to be a protective factor against first seizures in men. For men with unprovoked seizures, the adjusted odds ratio was 0.42 (95% CI 0.22-0.82) for ever marijuana use and 0.36 (95% CI 0.18-0.74) for marijuana use within 90 days of hospitalization. For men with provoked seizures, respective adjusted odds ratios were 1.03 (95% CI 0.36-2.89) and 0.18 (95% CI 0.04-0.84). Cocaine use, while common among study subjects, was not shown to be a significant risk factor either for all first seizures or for subgroups of seizures, regardless of the time of last use. The authors conclude that heroin use is a risk factor and marijuana use a protective factor for new-onset seizures.

The effects of intrauterine cocaine exposure in newborns

OBJECTIVES

We sought to determine the effects of intrauterine cocaine exposure in newborns, in an inner-city population in which cocaine use during pregnancy was common.

METHODS

During a 1-year period, 12.8% (361 of 2810) of all live singleton infants at Harlem Hospital in New York were identified as cocaine exposed, either by universal urine toxicologic screening or by maternal history. Cocaine-exposed infants were compared with a control group of 387 infants not known to be exposed to cocaine or other illicit drugs.

RESULTS

Low birthweight (< 2500 g) was more common among cocaine-exposed infants (31% vs 10%), as was preterm birth (< 37 completed weeks of gestation) (32% vs 14%). In multivariate analyses controlled for demographic and life-style factors and duration of gestation, cocaine was associated with decreased birthweight (154 g), length (1.02 cm), head circumference (0.69 cm), and duration of gestation (0.74 weeks). The birthweight deficits were larger for infants born to mothers who used cocaine in combination with other drugs (195 g) and for infants born to mothers who specifically admitted using crack (200 g).

CONCLUSIONS

Intrauterine cocaine exposure is linked with fetal growth retardation and shortened gestation in this population.

Sweet's syndrome: a spectrum of unusual clinical presentations and associations

BACKGROUND

Sweet's syndrome (SS) is the prototypic neutrophilic dermatosis. First described in 1964, the characterization of new clinical associations, unique histopathological findings and clinical variants have stimulated much interest and discussion recently. However, the prevalence of these unusual variants and clinical associations within a single cohort of patients, has not been described.

OBJECTIVES

To describe and evaluate the prevalence of unusual clinical and histopathological features, as well as the clinical associations of SS seen in patients from the National Skin Centre, Singapore.

METHODS

This is a retrospective study of all consecutive cases of SS seen at our centre over a 5.5-year period (June 1999-December 2004). Data on associated systemic diseases was obtained from the medical records and matched with information from the National Cancer Registry, Singapore. Patients not actively followed up for more than 3 months were contacted for their updated health status.

RESULTS

Thirty-seven patients were identified. Ten (27%) had non-idiopathic SS. These were associated with haematological disorders, connective tissue disorders, infections or a drug. Twenty-nine patients (78%) had at least one atypical clinical or histopathological feature. Atypical clinical features included bullous lesions, SS with hand involvement or neutrophilic dermatoses of the hands and the concomitant existence of subcutaneous SS with pyoderma gangrenosum. SS was the presenting feature in three patients with infections caused by atypical organisms, including Mycobacterium chelonae, Penicillium species and Salmonella type D. Unique histopathological variants included subcutaneous SS and lesions containing an admixture of mature and immature neutrophils. Subcutaneous neutrophilic inflammation seemed to be more common in patients with an underlying haematological disorder. This group of patients also had a lower mean haemoglobin level.

CONCLUSIONS

Unusual clinical and histopathological variants of SS described in the literature are similarly encountered in our cohort of patients, with some features being more common than others. We highlight and discuss some unique clinical and histopathological observations seen in our patients with SS.

Hypertension and the risk of new-onset unprovoked seizures

We tested the a priori hypothesis that hypertension can lead to seizures through vascular brain damage that might or might not involve manifest stroke. A case-control study with 227 patients admitted for a first unprovoked seizure and 294 acute surgical controls was carried out at Harlem Hospital Center, New York City, between 1981 and 1984. History of hypertension was significantly associated with unprovoked seizures, even after adjustment for antecedent stroke and other potential confounders (adjusted odds ratio [OR] = 1.57; 95% confidence limit [CL], 1.0 to 2.44). There was marked synergism between history of stroke and history of hypertension; subjects with a history of both had a fourfold increase in seizure risk compared with subjects with neither (adjusted OR = 4.07; 95% CL, 1.50 to 11.0). In these data, history of hypertension appears to be an independent risk factor for new-onset unprovoked seizures, especially, but not only, in conjunction with a history of stroke.

Cocaine use during pregnancy: sensitive detection by hair assay

OBJECTIVES

This paper compares the sensitivity of two tests of cocaine use, interview and urine test, with that of a radioimmunoassay of hair.

METHODS

Interviews and hair samples were provided by 397 obstetric patients in one New York City hospital; urine samples were obtained in 377. Of these patients, 241 were receiving prenatal care (were registered) and 156 delivered without prenatal care (were unregistered). The 241 registered patients were derived from 400, comprising all reporting use of cocaine ever ("ever-users"), all reporting use by the father but not themselves ("lifestylers"), and a sample of women who were neither ever-users nor lifestylers. The 156 unregistered patients were derived from 352 women interviewed at delivery, unselected for reported use.

RESULTS

Thirty-two percent reported ever using cocaine, 45% of these within 6 months before interview. Urine tests were positive in 20%, hair tests in 59%. The estimated sensitivity of the hair test (92%) was 3.1 times higher than that of the urine test (95% confidence interval [CI] = 2.5, 3.8) and 4 times higher than that of reported use in the past 6 months (95% CI = 3.2, 5.0).

CONCLUSIONS

Self-report and urine tests alone miss most of cocaine users during pregnancy. Hair tests greatly improve detection and thus can enhance evaluations of the effects of prenatal cocaine use on fetal and child development.

Metagenomic Reconstruction of Key Anaerobic Digestion Pathways in Municipal Sludge and Industrial Wastewater Biogas-Producing Systems

Anaerobic digestion (AD) is a microbial process widely used to treat organic wastes. While the microbes involved in digestion of municipal sludge are increasingly well characterized, the taxonomic and functional compositions of AD digesters treating industrial wastewater have been understudied. This study examined metagenomes from a biogas-producing digester treating municipal sludge in Shek Wu Hui (SWH), Hong Kong and an industrial wastewater digester in Guangzhou (GZ), China, and compared their taxonomic composition and reconstructed biochemical pathways. Genes encoding carbohydrate metabolism and protein metabolism functions were overrepresented in GZ, while genes encoding functions related to fatty acids, lipids and isoprenoids were overrepresented in SWH, reflecting the plants' feedstocks. Mapping of genera to functions in each community indicated that both digesters had a high level of functional redundancy, and a more even distribution of genera in GZ suggested that it was more functionally stable. While fermentation in both samples was dominated by Clostridia, SWH had an overrepresentation of Proteobacteria, including syntrophic acetogens, reflecting its more complex substrate. Considering the growing importance of biogas as an alternative fuel source, a detailed mechanistic understanding of AD is important and this report will be a basis for further study of industrial wastewater AD.

Natural history and predictors for progression of mild childhood obstructive sleep apnoea

AIMS

The natural history of mild childhood obstructive sleep apnoea (OSA) was examined and factors associated with disease progression were identified.

METHODS

Subjects were recruited from an epidemiological study which examined the prevalence of OSA in Chinese children aged 6-13 years. The first 56 consecutive children identified with mild OSA (apnoea-hypopnoea index 1-5) were invited for a repeat assessment 2 years after the diagnosis.

RESULTS

45 children participated in the follow-up study, in 13 of whom (29%) the OSA was found to have worsened. Compared with those in whom OSA had not worsened, the worsened OSA group had a greater increase in waist circumference, a higher prevalence of large tonsils (occupying > or =50% of the airway) at both baseline and follow-up, and a higher prevalence of habitual snoring at both baseline and follow-up. The presence of large tonsils had a positive predictive value of 53% and a negative predictive value of 83% for worsening OSA over a 2-year period. Multivariate linear regression analysis showed that the change in obstructive apnoea-hypopnoea index was associated with age at baseline (beta (SE) = -0.92 (0.34), p = 0.009), gender (male = 1; female = 0) (beta (SE) = 4.69 (1.29), p<0.001), presence of large tonsils at baseline (beta (SE) = 4.36 (1.24), p = 0.001), change in waist circumference (beta (SE) = 0.30 (0.09), p = 0.002) and persistently large tonsils (beta (SE) = 5.69 (1.36), p<0.001) over the 2-year period.

CONCLUSIONS

Mild OSA in the majority of children does not resolve spontaneously. Subjects with tonsillar hypertrophy, especially boys, should be closely monitored to allow early detection of worsening OSA. Weight control should be stressed in the management of childhood OSA.

Alcohol, seizures, and epilepsy

Seizures, epilepsy, and alcohol are complexly interrelated. Although it is commonly perceived that patients with epilepsy experience problems with seizure control if they use alcohol, this is not confirmed by the few experimental studies that have tested the hypothesis. The last 30 years have emphasized the role of withdrawal from alcohol as a mechanism of seizure production. However, this is but one of many potential mechanisms by which seizures and epilepsy may be related to alcohol use and abuse. The rare but clear situations in which alcohol can act as a convulsant drug need further study, and mechanisms by which the long-term neurotoxic effects of alcohol lead to chronic epilepsy also need further elucidation.

Changing trends in the epidemiology of contact dermatitis in Singapore

All patients seen in the Contact Dermatitis Clinic of the National Skin Centre, Singapore (and the former Middle Road Hospital) between January 1986 and December 1990 were analysed retrospectively. 5557 patients comprising 2634 (47.4%) males and 2923 (52.6%) females were patch tested. 3154 (56.8%) patients had 1 or more positive reactions. The majority of the patients were Chinese (78.0%), followed by Malays (11.5%), Indians (8.1%) and other minority races (2.4%). The majority of positive reactions belonged to the 21-40 age group. The incidence of positivity decreased after 60 years. The commonest allergens responsible were nickel (17.7%), fragrance (13.3%), neomycin (6.9%), colophony (6.6%) and proflavine (6.5%). Both neomycin and proflavine were commonly used as over-the-counter medicaments. Compared to an earlier report in 1988, there were differences in the incidence of contact sensitivity to some allergens. Potassium dichromate, which used to be a common allergen, was less common. Some allergens (carba-mix, naphthyl-mix, caine-mix and PCMX) have been removed from our standard series as they were uncommon causes of contact allergy. Thimerosal and Amerchol L-101 were added in their place.

The Evolution of GABAA Receptor–Like Genes

The inhibitory ligand-gated ion channel family of receptors, including the type A gamma-aminobutryic acid (GABA(A)) and glycine receptors, mediates inhibitory neurotransmissions in the central nervous system. In this study, GABA receptor (GABR) evolution was explored through comparative genomics using genomes that span divergent lineages. GABA(A)/Gly receptor-like (GRL) gene sequences were retrieved from the genomes of various species ranging from mammal to fish to worm and subjected to cross-species comparison. All vertebrate GRL gene sets in the study but no invertebrate ones exhibit the extensive and conserved pattern of gene clustering that is characteristic of human GABR genes, indicating that the gene clusters were established early in vertebrate evolution, after divergence from the invertebrates. Moreover, the vertebrate gene structure is highly conserved with a basic 9-coding exon structure, whereas, as well as being diverse in copy numbers and chromosomal loci, the invertebrate GRL genes display a variety of gene structures. Remarkably, the invertebrates each possess a unique GRL gene pair that lies in neighboring loci within their respective genomes: zc482.5 and zc482.1 in roundworm, CG8916 and CG17336 in fruitfly, Ci4249 and Ci4254 in Ciona, and these were revealed by phylogenetic analysis to be homologous to human GABR alpha and beta subunits, respectively. The phylogenetic classification of these genes is also corroborated by experimental ligand-binding measurements using recombinant gene products. Furthermore, the 3 invertebrate gene pairs harbor characteristic key residues and exhibit similarities in intron positions to their vertebrate counterparts. The results strongly indicate that such a gene pair originally existed in the bilaterian ancestor from which all 3 phyla evolved and suggest that the extant GABR clusters arose from an ancestral alpha-beta subunit gene pair gave rise to the extant GABR clusters.

GABRB2 association with schizophrenia: commonalities and differences between ethnic groups and clinical subtypes

BACKGROUND

Single nucleotide polymorphisms (SNPs) and haplotypes in intron 8 of type A gamma-aminobutyric acid (GABA(A)) receptor beta2 subunit gene (GABRB2) were initially found to be associated with schizophrenia in Chinese. This finding was subjected to cross-validation in this study with Japanese (JP) and German Caucasian (GE) subjects.

METHODS

Single nucleotide polymorphisms discovery and genotyping were carried out through resequencing of a 1839 base pair (bp) region in GABRB2. Tagging SNPs (tSNPs) were selected based on linkage disequilibrium (LD), combinations of which were analyzed with Bonferroni correction and permutation for disease association. Random resampling was applied to generate size- and gender-balanced cases and control subjects.

RESULTS

Out of the 17 SNPs (9.2/kilobase [kb]) revealed, 6 were population-specific. Population variations in LD were observable, and at least two low LD points were identified in both populations. Although disease association at single SNP level was only shown in GE, strong association was demonstrated in both JP (p = .0002 - .0191) and GE (p = .0033 - .0410) subjects, centering on haplotypes containing rs1816072 and rs1816071. Among different clinical subtypes, the most significant association was exhibited by systematic schizophrenia.

CONCLUSIONS

Cross-population validation of GABRB2 association with schizophrenia has been obtained with JP and GE subjects, with the genotype-disease correlations being strongest in systematic schizophrenia, the most severe subtype of the disease.

Ten-year consistency in neurological test performance of children without focal neurological deficit

To assess 'soft-sign' persistence and its correlates outside a referred sample, 159 members of a local birth cohort of the United National Collaborative Perinatal Project were traced and their performance on six neurological test scales was measured at age 17 by examiners blind to their status at age seven. A comparison group was also formed, who had been 'sign-free' at age seven. On four of the six tests (dysdiadochokinesis, mirror movements, dysgraphesthesia and motor slowness) index boys did significantly worse than the comparison boys; by contrast, index girls scored significantly worse than comparisons only on motor slowness.

The role of the extracellular matrix in primary myelofibrosis

Primary myelofibrosis (PMF) is a myeloproliferative neoplasm that arises from clonal proliferation of hematopoietic stem cells and leads to progressive bone marrow (BM) fibrosis. While cellular mutations involved in the development of PMF have been heavily investigated, noteworthy is the important role the extracellular matrix (ECM) plays in the progression of BM fibrosis. This review surveys ECM proteins contributors of PMF, and highlights how better understanding of the control of the ECM within the BM niche may lead to combined therapeutic options in PMF.