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Carrier detection and prenatal diagnosis in Duchenne and Becker muscular dystrophy.

Estimating carrier risks for female relatives of Duchenne (DMD) and Becker (BMD) dystrophy sufferers depends upon calculation of segregational risks, supplemented by enzyme tests which show considerable overlap between carrier and control data. Linkage analysis has substantially increased the accuracy of segregational risk estimation, but a small error rate is still inherent when interpreting results, owing to recombination between the mutation causing the disease, and the marker used. It also requires family studies, which may be difficult to complete. The presence of intragenic DNA deletions in about half of D/BMD boys, allows direct detection of the D/BMD mutation, and is a powerful diagnostic tool. These techniques can be used for both prenatal diagnosis and carrier detection.

Chromosome Deletion↗

The evolution of the alcohol dehydrogenase gene family by loss of introns in plants of the genus Leavenworthia (Brassicaceae).

We present results showing that several species in the plant genus Leavenworthia, in the Brassica family, have three alcohol dehydrogenase loci, unlike Arabidopsis thaliana, which has only a single classical (class P) alcohol dehydrogenase locus. Based on a portion of the sequence, the alcohol dehydrogenase loci of Leavenworthia show about 92%-93% amino acid sequence identity to that of the A. thaliana alcohol dehydrogenase. The great majority of the sequence differences from the A. thaliana Adh-coding sequence, and also between three different Leavenworthia species, are synonymous, suggesting that all are currently functional (or have been in the recent evolutionary past). The loci differ in the numbers of introns present, with one locus (Adh-3) having no introns present. RT-PCR tests detect expression of all three loci. Linkage data using variant alleles identified by single-strand conformation polymorphism analysis show that the three Leavenworthia loci are not closely linked. The results therefore suggest that the Adh-3 locus may have arisen via an mRNA intermediate but, despite loss of the introns, is expressed.

Alcohol Dehydrogenase↗

HIV prevalence in pregnant women in an ethnically diverse population in the UK: 1998-2002.

OBJECTIVE: To describe trends in the prevalence of HIV in an ethnically diverse population of pregnant women in the United Kingdom. METHODS: Data on parental country of birth from national birth registration records were linked to neonatal dried blood spot samples routinely collected for neonatal screening in the North Thames region between 1998 and 2002. Identifiers were subsequently irreversibly deleted prior to establishing maternal HIV status by testing the neonatal samples. RESULTS: A total of 491 213 dried blood spot samples were collected, and 490 879 (99.93%) were tested for HIV. Of these, 1029 were seropositive. There was an overall significant increasing trend (P-value = 0.001) between 1998 and 2002. Maternal region of birth was available for 89.8% of HIV-infected samples, and, among these, 80.5% of mothers were born in sub-Saharan Africa and 11.1% in the UK. The highest prevalences of HIV were in women born in sub-Saharan Africa (2.09%). If both parents were born in the UK, overall seroprevalence was 0.016%. CONCLUSION: HIV infection in pregnant women in the UK continues to occur predominantly in women born in sub-Saharan Africa with prevalence in this group increasing significantly. Although the absolute number of HIV-infected women rose in some other groups, there was no evidence for a statistically significant rise in HIV prevalence in women born outside sub-Saharan Africa. Over 93% of children at risk of vertical transmission of HIV had at least one parent born abroad. This paper underlines the value of data linkage in monitoring HIV prevalence in a diverse population.

Adult↗

Cancer incidence in a cohort of licensed pesticide applicators in Florida.

This study is a standardized incidence ratio (SIR) analysis of cancer incidence of licensed pesticide applicators in Florida, compared with that of Florida's general population. Through extensive data linkages, 33,658 applicators were assembled who had 1266 incident cancers and 279,397 person-years from January 1, 1975, to December 31, 1993. Disease risk from ethanol and tobacco use were significantly decreased. Among males, prostate cancer (SIR = 1.91; 95% confidence interval [CI], 1.72-2.13) and testicular cancer (SIR = 2.48; 95% CI, 1.57-3.72) were significantly elevated. No confirmed cases of soft tissue sarcoma (STS) were found, and the incidence of non-Hodgkin's lymphoma was not increased. There were few female applicators; nevertheless, cervical cancer incidence (SIR = 3.69; 95% CI, 1.84-6.61) was significantly increased, while the incidence of breast cancer was significantly decreased. Cancers that have been associated with estrogen disrupters were found in male, but not female, pesticide applicators. The lack of soft tissue sarcoma is at odds with prior literature associated with the use of phenoxy herbicides.

Adult↗

Linking birth certificates with Medicaid data to enhance population health assessment: methodological issues addressed.

This study linked birth certificates with Minnesota Medicaid deliveries in order to identify Medicaid births. This article describes the link between methodology and results. Medicaid claims from 1997 were used to identify women with a delivery code. Identifiers for these women were linked to birth certificate files, with a match rate of 93.2 percent. Women's match status did not differ by maternal age. Women in some border counties matched at much lower rates than the rest of the population. The methodology was effective in linking Medicaid and birth certificate data and will be implemented as a data linkage protocol for Minnesota.

Birth Certificates↗

Bacteriophage PBSX-induced deletion mutants of Bacillus subtilis 168 constitutive for alkaline phosphatase.

Mutants of Bacillus subtilis with deletions extending from the PBSX prophage, and in some cases removing pro(AB) and metC, have been found to be constitutive for vegetatively synthesized alkaline phosphatase. Such deletions were isolated by selecting for heat-resistant derivatives of a strain carrying a xhi-1479 mutation causing heat-inducibility of the defective phage PBSX. These deletions remove the phoS gene, a regulatory gene for alkaline phosphatase; it is concluded that the phoS gene product exerts negative control on alkaline phosphatase synthesis. Deletion mapping, combined with previously published linkage data, indicates a gene order of PBSX-phoS-pro(AB)-metC.

Alkaline Phosphatase↗

Characterization of the chromosomes of Bacillus subtilis merodiploid strains by quantitative DNA-DNA hybridization.

The position of junctions and the extent of the duplicated chromosomal regions in Bacillus subtilis merodiploid strains were studied by quantitative DNA-DNA hybridization. We describe a method which allows (i) the identification of genes present in two copies per chromosome and (ii) the measurement of the amount of additional DNA in chromosomes with relatively large duplicated regions (about 10% or more). Analysis of previously described B. subtilis merodiploid strains GSY1127, GSY1800 and GSY1835 revealed that the duplicated segments represent 29 +/- 2%, 7 +/- 2% and 13 +/- 2% of the chromosome, respectively. Small discrepancies between these and previous genetic linkage data are discussed. Support for a role of prophage SP beta in the formation of merodiploid GSY1835 is provided. In conclusion, the described method confirmed the genetic maps of the merodiploids previously obtained by transduction and transformation crosses and showed that a duplication of a segment is not accompanied by large deletions of other chromosomal regions, providing direct evidence that a cell can accommodate genomes of substantially increased size.

Bacillus subtilis↗

An integrated map of human chromosome 6p23.

The human chromosomal band 6p23 is a Giemsa-negative (light) band that may be expected to be relatively gene rich. The genes for spinocerebellar ataxia type 1 (SCA1), guanosine monophosphate reductase (GMPR), DEK involved in a subtype of acute myeloid leukemia (AML), and the folate-sensitive fragile site FRA6A, have already been mapped to 6p23. Recent linkage data have suggested evidence for a susceptibility locus for schizophrenia in the region. We have constructed a single YAC contig of approximately 100 clones spanning the entire 6p23 band from 6p22.3 to 6p24.1 and covering 7.5-8.5 Mb of DNA. The YAC contig contains 55 markers including genetically mapped STSs, physically mapped STSs, anonymous STSs, anonymous ESTs, and ESTs from the genes mapped to the region. The order of the genetically mapped STSs is consistent with their order in the contig and some of the markers not resolved on the genetic map have been resolved by the YACs. Four of the YACs from 6p23 and covering approximately 3 Mb of DNA have been used to isolate approximately 300 cosmids from a flow-sorted human chromosome 6 cosmid library, which have been organized into pockets. The proposed susceptibility locus for schizophrenia is most closely linked to D6S260, which is located within the YAC contig along with genetic markers < or = 5 cM on either side. Therefore, the presented materials are valuable reagents for characterization of the genomic region implicated in schizophrenia.

Base Sequence↗

Ultrasound estimates of gestational age among perinatally demised: a population-based study.

BACKGROUND: Correct estimation of gestational age may improve the quality of obstetric care. We hypothesize that significant differences between traditional and alternative estimates by ultrasound are evident among perinatal deaths. METHODS: Population-based case series with data linkage between autopsy records and The Medical Birth Registry of Norway, including perinatally demised singletons who were examined by autopsy and post-mortem radiography, having antenatal estimates of gestational age both by the calendar method, as calculated from the first day of the last menstrual period preceding the pregnancy (GAlmp), and by mid-second-trimester ultrasound (GAus), N = 380. The main outcome measure was the distribution of GAlmp and GAus within weight strata. RESULTS: Mean GAus was 1 week less than mean GAlmp (t-test, p < 0.001). The degree of apparent growth restriction manifest after death, as expressed by both birthweight and by post-mortem radiographic measurements, was fairly well correlated with the degree of downward adjustment of age by ultrasound in the early second trimester (Pearson's correlation, r = - 0.599, p < 0.001). The degree of discrepancy between the ultrasound and the calendar methods was associated both with placenta findings (Kruskal-Wallis test, chi2 = 20.95, p = 0.007) and with the main cause of death (Kruskal-Wallis test, chi2 = 27.65, p = 0.004). CONCLUSION: Among infants who died perinatally, gestational age seemed to be systematically downward adjusted by mid-second-trimester screening ultrasound, particularly among those who were the most growth retarded at the time of death.

Case-Control Studies↗

CARD15/NOD2 single nucleotide polymorphisms do not confer susceptibility to type I psoriasis.

BACKGROUND: A psoriasis susceptibility locus on chromosome 16q was identified recently. This region coincides with a locus predisposing to Crohn's disease. Patients with Crohn's disease have a fivefold greater relative risk for development of psoriasis. In Crohn's disease mutation of the caspase recruitment domain family, member 15 (CARD15) gene (chromosome 16q12.1) confers susceptibility. In light of the overlap in linkage data, and the observation of comorbidity between Crohn's disease and psoriasis, it is plausible that both diseases share a common genetic factor. OBJECTIVES: To assess the genetic contribution of CARD15 single nucleotide polymorphisms (SNPs) in the pathogenesis of type I psoriasis. METHODS: Eight SNPs in CARD15 were genotyped in 148 patients with type I psoriasis and 192 unrelated controls, following a test for population stratification. Genotype and allele frequencies were compared along with estimated SNP haplotype frequencies. RESULTS: No differences were observed in genotype allele or haplotype frequencies between the case and control cohorts. CONCLUSIONS: The most complete assessment of CARD15 SNPs in type I psoriasis to date reveals no evidence of association to type I psoriasis.

Adult↗

Socioeconomic and rural differences for cataract surgery in Western Australia.

BACKGROUND: To examine the relationship between socioeconomic factors, residential locality and cataract surgery incidence. METHODS: This was a population-based study using the Western Australian Data Linkage System to identify all cataract operations performed in patients aged 50+ years in 1996 and 2001. Patients' residential addresses at the time of operation were geocoded to census localities. Using census-derived indices, procedures were categorized into socioeconomic groups and residential locations (metropolitan and rural). Poisson regression was used to analyse for differences in procedure rates. RESULTS: The crude cataract surgery rate in Western Australia increased from 4458 to 6631 procedures per million person-years between 1996 and 2001. Female and older patients underwent more surgery. Metropolitan residents were more likely to undergo surgery compared with rural residents; a difference that increased by 17% between 1996 and 2001 (1996: incidence rate ratio [IRR] 1.07, 95% confidence interval [CI] 1.02-1.13; 2001: IRR 1.24, 95% CI 1.18-1.29). A pronounced 'U-shaped' pattern of difference had developed for socioeconomic disadvantage by 2001. The most advantaged underwent 9% more surgery than the most disadvantaged. Rates in the middle two groups were less than the lowest one. CONCLUSION: There was growing inequity in the rates of cataract surgery for rural and poorer patients between 1996 and 2001. These differences partly reflect the increasingly two-tiered Australian health system with more privately provided cataract surgery in urban areas.

Aged↗

Inequalities in rural health care: differences in surgical intervention between metropolitan and rural Western Australia.

BACKGROUND: To compare surgical procedure rates between metropolitan and rural/remote residents in Western Australia (WA). METHODS: The WA Data Linkage System was used to identify all patients who underwent a procedure for cataract, ureteric calculi or urinary outflow obstruction symptoms for the time periods 1981-2000, 1981-1997 and 1981-1995, respectively. Age-standardized procedure rates were calculated and Poisson regression modelling was used to estimate effects of locality of residence and demographic covariates. RESULTS: Overall, rural/remote patients underwent first-time procedures for cataract (IRR 0.92; 95% CI 0.90-0.94), ureteric calculi (0.76; 0.72-0.80), or urinary outflow obstruction (0.71; 0.69-0.74) less frequently than patients in the metropolitan area. They were also significantly less likely to undergo multiple procedures for cataracts (0.90; 0.88-0.91) and ureteric calculi (0.69; 0.67-0.73). CONCLUSION: A distinctly reduced level of surgical intervention was found in rural patients for three generally non-life threatening conditions. The reasons for this require further investigation.

Adult↗

Long-term survival outcomes following breast cancer surgery in Western Australia.

BACKGROUND: Mortality rates from breast cancer are stabilizing or falling in many developed countries including Australia, however, survival outcomes are known to vary by social, demographic and treatment related factors. The aim of the present study was to investigate how hospital, social and demographic factors were associated with survival outcomes from surgically treated breast cancer for all women living in Western Australia. METHODS: The WA Data Linkage System was used to access hospital morbidity, death and cancer information for all women diagnosed with invasive breast cancer in Western Australia 1982-2000. Relative survival and Cox proportional hazards regression analyses were used to identify social, demographic and hospital factors associated with an increased risk of dying from breast cancer or dying from any cause. RESULTS: Survival outcomes improved in all women diagnosed in more recent calendar periods. However, a significantly increased risk of dying was observed for women who underwent initial surgical treatment in regional public hospitals outside of the state capital, Perth. Consistent with other reports, women aged greater than 80 years and younger than 35 years at diagnosis also had poorer survival outcomes. Residential location, socioeconomic status and race were not associated with survival after adjusting for treatment, health and hospital related factors. CONCLUSIONS: Despite overall improvements in survival of women diagnosed with breast cancer in Western Australia, initial surgical treatment in public hospitals outside of Perth was associated with significantly poorer outcomes.

Adult↗

Colorectal cancer surgical care and survival: do private health insurance, socioeconomic and locational status make a difference?

BACKGROUND: The purpose of the present paper was to examine patterns of surgical care and the likelihood of death within 5 years after a diagnosis of colorectal cancer, including the effects of demographic, locational and socioeconomic disadvantage and the possession of private health insurance. METHODS: The Western Australian Data Linkage System was used to extract all hospital morbidity, cancer and death records for people with a diagnosis of colorectal cancer from 1982 to 2001. Demographic, hospital and private health insurance information was available for all years and measures of socioeconomic and locational disadvantage from 1991. A logistic regression model estimated the probability of receiving colorectal surgery. A Cox regression model estimated the likelihood of death from any cause within 5 years of diagnosis. RESULTS: People were more likely to undergo colorectal surgery if they were younger, had less comorbidity and were married/defacto or divorced. People with a first admission to a private hospital (odds ratio (OR) 1.31, 95% confidence interval (CI): 1.16-1.48) or with private health insurance (OR 1.27, 95% CI: 1.14-1.42) were more likely to undergo surgery. Living in a rural or remote area made little difference, but a first admission to a rural hospital reduced the likelihood of surgery (OR 0.76, 95% CI: 0.66-0.87). Residency in lower socioeconomic areas also made no difference to the likelihood of having surgical treatment. The likelihood of death from any cause was lower in those who were younger, had less comorbidity, were elective admissions and underwent surgery. Residency in lower socioeconomic status and rural areas, admission to a rural hospital or a private hospital and possession of private health insurance had no effect on the likelihood of death. CONCLUSIONS: The present study demonstrates that socioeconomic and locational status and access to private health care had no significant effects on surgical patterns of care in people with colorectal cancer. However, despite the higher rates of surgery in the private hospitals and among those with private health insurance, their survival was no better.

Age Factors↗

Risk of death in prisoners after release from jail.

OBJECTIVE: To compare the risk of death in a cohort of Western Australian released prisoners with the risk experienced by the general population of Western Australia. METHODS: A cohort study of prisoners in Western Australia whose last date of release ranged from 1 January 1994 to 1 January 1999. Overall mortality and cause of death were determined by data linkage to the Registrar General's record of deaths. RESULTS: Aboriginal prisoners had a significantly lower survival rate after release than non-Aboriginal prisoners (p < 0.0001). When compared with their peers in the Western Australian community, both Aboriginal and non-Aboriginal prisoners were found to have an increased relative risk of death. Female non-Aboriginal released prisoners aged between 20 and 40 years were 17.8 (95% CI 8.1-27.5) times more likely to die than other female non-Aboriginals in Western Australia in the same age range. Male non-Aboriginal prisoners aged 20-40 years were 6.3 (95% CI 5.2-7.4) times more likely to die than their counterparts in the WA community. Female Aboriginal released prisoners were 3.4 (95% CI 1.2-5.6) times more likely to die than their peers, while male Aboriginal released prisoners were 2.9 (95% CI 2.2-3.5) times more likely to die. In their first six months after release, female non-Aboriginal prisoners aged 20 to 40 years were 69.1 (95% CI 17.9-120.3) times more likely to die than their counterparts in the WA community. The main causes of excess death were related to drug and alcohol abuse. CONCLUSION: All prisoners were at greater than expected relative risk of death after release from prison, with female non-Aboriginal prisoners at particularly high relative risk.

Adult↗

Demographic factors as predictors for hospital admission in patients with chronic disease.

OBJECTIVE: To identify demographic predictors of hospital admission for chronic disease. METHODS: Hospital morbidity records were extracted from the WA Data Linkage System for the period 1994-99 for specific chronic diseases based on national priorities. Poisson regression was used to estimate the effects of Aboriginal and Torres Strait Islander (ATSI) descent, co-morbidity, geography, socio-economic status and possession of health insurance on hospital admission rates. RESULTS: This study has identified some of the main demographic risk factors for hospitalisation in patients with chronic disease as the following: being male, of ATSI descent, living in a relatively disadvantaged Census Collection District and having multiple co-morbidities. Depending on the disease, locational disadvantage and possession of private health insurance were also risk factors. CONCLUSIONS: The study indicates that a crucial component in keeping patients with chronic disease out of hospital is ensuring quality primary care for all members of the community, equipping patients with the necessary skills to self-manage their chronic condition. Particular attention must be given to developing programs that are accessible to the more disadvantaged members of the community. IMPLICATIONS: Programs aimed at keeping patients with chronic disease out of hospital must be targeted at the most vulnerable groups of the population if they are to be effective.

Australia↗

Site-directed immobilization of glycoproteins on hydrazide-containing solid supports.

Methods are described for the preparation and use of solid supports containing hydrazide functions for the immobilization of glycoproteins specifically through the oligosaccharide moieties. The solid supports are prepared from commercial "active ester" agarose by reaction with hydrazine hydrate. Glycoproteins are oxidized with sodium periodate, resulting in the production of aldehydes on the oligosaccharide moieties. Oxidized glycoprotein is then reacted with the hydrazide-derivatized solid support to produce stable hydrazone linkages. Data are presented for the optimization of binding of oxidized glycoprotein to hydrazide-derivatized agarose. Agarose hydrazide/glycoprotein gels were shown to be stable from pH 3 to 10 and activity studies using immobilized avidin show that this method of immobilization results in an increased "specific activity" of bound protein when compared with standard methods of immobilization.

Chromatography, Affinity↗

Hysterectomy following sterilization.

Using record linkage data derived from Scottish hospital discharge summaries, admissions to gynaecological units and hysterectomy rates have been studied following sterilization. The average annual gynaecological admission rate per 1000 women was 43.7 in the group of sterilized women and 21.5 in the control subjects. The average annual hysterectomy rate was 9.3 in the sterilized women and 2.5 in the control subjects. Although there were differences in age and pregnancy number between cases and controls, these did not account for the observed differences. This study was not able to determine whether the increase in gynaecological morbidity was due to the sterilization procedure or to the characteristics of the women sterilized.

Adult↗