PubMed Health⌕ Search

Biomedical subjects

A Crosby

Publications and source records attributed to A Crosby.

10 recordsLinked to original sources

Early carbon monoxide intoxication: happy to be poisoned?

Carbon monoxide poisoning is the commonest cause of death by poisoning in the UK and chronic exposure is thought to be a frequently missed diagnosis. Early recognition of carbon monoxide poisoning is vital to institute prompt treatment and to prevent exposure to others. An incident of mass exposure to carbon monoxide is presented where euphoria, lasting several hours, was the only symptom reported in approximately one quarter of the casualties. This has not been reported previously and we believe that mild carbon monoxide intoxication should be included in the list of differential diagnoses of inappropriate euphoria.

Adolescent↗

Identification of a deletion in plakoglobin in arrhythmogenic right ventricular cardiomyopathy with palmoplantar keratoderma and woolly hair (Naxos disease).

BACKGROUND: Arrhythmogenic right ventricular cardiomyopathy (ARVC) is an autosomal dominant heart muscle disorder that causes arrhythmia, heart failure, and sudden death. Previously we mapped the genetic locus for the triad of autosomal recessive ARVC, palmoplantar keratoderma, and woolly hair (Naxos disease) to chromosome 17q21, in which the gene for plakoglobin is encoded. This protein is a key component of desmosomes and adherens junctions, and is important for the tight adhesion of many cell types, including those in the heart and skin. METHODS: We studied 19 individuals with Naxos disease, as well as unaffected family members and unrelated individuals from the neighbouring Greek islands of Naxos and Milos. Gene sequence was determined by reverse transcriptase PCR from RNA isolated from the skin of an affected individual and mutations in other cases were confirmed by restriction-enzyme analysis. FINDINGS: A homozygous 2 base pair deletion in the plakoglobin gene was identified only in the 19 affected individuals. This deletion caused a frameshift and premature termination of the protein, which was shown by western blot analysis. 29 clinically unaffected family members were heterozygous for the mutation; 20 unrelated individuals from Naxos and 43 autosomal dominant ARVC probands were homozygous for the normal allele. INTERPRETATION: The finding of a deletion in plakoglobin in ARVC suggests that the proteins involved in cell-cell adhesion play an important part in maintaining myocyte integrity, and when junctions are disrupted, cell death, and fibrofatty replacement occur. Therefore, the discovery of a mutation in a protein with functions in maintaining cell junction integrity has important implications for other dominant forms of ARVC, related cardiomyopathies, and other cutaneous diseases.

Alleles↗

Linkage of recessive Robinow syndrome to a 4 cM interval on chromosome 9q22.

Autosomal recessive Robinow syndrome is a form of mesomelic dwarfism with multiple rib and vertebral anomalies. Using autozygosity mapping we have identified a genetic locus (RBNW1) for this syndrome at chromosome 9q22 in seven consanguineous families from Oman. Our results indicate that the gene lies within a 4 cM region between markers D9S1836 and D9S1803 (maximum multipoint LOD score 12.3). In addition, we have analysed two non-Omani families with autosomal recessive Robinow and found no genetic heterogeneity.

Bone and Bones↗

Prenatal diagnosis and the subsequent mutation analysis in a family with carbohydrate-deficient glycoprotein type I syndrome: growing evidence to support founder effects within CDG1 populations.

Carbohydrate deficient-glycoprotein syndrome type I (CDG1 or Jaeken Syndrome) is an autosomal recessive multisystem disease with severe early involvement of the nervous system. Mutations in the phosphomannomutase 2 (PMM2) gene have recently been identified in 16 affected individuals. In the current study, we have described a CDG1 family where gene tracking had been used to perform prenatal diagnosis before the isolation of the CDG1 gene. Haplotype analysis indicated that the unborn child had inherited the maternal 'normal' allele, but a critical recombination event meant that it was impossible to determine if the child had inherited the paternal mutation. Single-strand conformation polymorphism and sequence analysis revealed that the mother was a carrier of a C-->A transversion at position 357 (F119L), and that the father was a carrier of a G-->A transition at position 425 (R141H). The unborn child had inherited the paternal R141H mutation. Because only three mutations have previously been reported in UK families, of which F119L and R141H are two, and given that there is evidence of allelic association in CDG1 families, it is possible that a limited number of ancestral mutations have given rise to most cases of CDG1 in any one population.

Chromosomes, Human, Pair 16↗

Evidence from a Ghanaian population of known African descent to support the proposition that hemochromatosis is a Caucasian disorder.

Mutations in the HFE gene on chromosome 6 are believed to cause the iron overload disorder hemochromatosis, the most common single gene disorder in northern Europeans. Two mutations have been described previously: C282Y, with an allele frequency of between 3% and 10% in the caucasian population, and H63D, which has an allele frequency of 16%. Published data shows that C282Y appears to be causative in the homozygous state, while the frequency of H63D/C282Y compound heterozygotes is much greater than expected in patient groups. There also appears to be a slightly elevated risk for H63D homozygotes. Hemochromatosis has been thought to be primarily a caucasian disorder. We have studied 97 healthy, black Ghanaian subjects, whose parents and grandparents were also African, to find the frequency of the two mutations. C282Y was absent, while H63D occurred in 2 individuals. These differences are significant at the 0.05 and 0.001 levels, respectively. The prevalence of H63D homozygotes in this population at 1 in 10,000 is clearly of no use in studying the effect of this genotype on phenotype. However, this study suggests an absence of the C282Y mutation in African populations, and the possibility that other populations might provide different genotypes and hence an analysis of H63D risk. A possible heterozygote advantage for the mutation is discussed.

Adult↗

Missouri Firearm-Related Injury Surveillance System.

CONTEXT: The Missouri Department of Health collects hospital inpatient and emergency room records statewide. With mortality data, they make up a population-based surveillance system of firearm-related injuries. Much information is not captured by these data, however. OBJECTIVE: During a three-year project we attempted to develop a timely, representative, and sensitive surveillance system of firearms-related injuries and their circumstances. DESIGN: The surveillance system consisted of Missouri's hospital and mortality records linked to police records of firearm incidents. SETTING: Lack of standardization of police department data precluded a statewide surveillance system; therefore, we concentrated on the two largest urban areas, St. Louis and Kansas City. PARTICIPANTS: Firearm-related injuries occurring during crimes in the surveillance area in 1994 were recorded. Wounds inflicted unintentionally or during suicide attempts were excluded. MAIN OUTCOME MEASURES: We evaluated the system according to its simplicity, flexibility, acceptability, sensitivity, predictive value positive, representativeness, and timeliness. RESULTS: The surveillance system was neither timely nor simple. Though estimated to represent 95% of the desired cases, information about the firearms and the circumstances was relatively scant. CONCLUSIONS: Police records as they now exist cannot be included in a statewide firearms surveillance system. The cost/benefit ratio does not justify even a regional surveillance system. Standardization of police records would be helpful, but some information will always be lacking unless the perpetrator is arrested.

Adolescent↗

Human mitochondrial malic enzyme variants: properties of the different polymorphic forms.

1. The human mitochondrial malic enzyme polymorphism was found to exist in the Scottish population with similar allele frequencies to those reported previously for Caucasian populations. 2. The mitochondrial malic enzyme variants MEM1, MEM2-1 and MEM2 which form the polymorphism have been separated from the cytoplasmic malic enzyme and partially purified by DEAE Sephadex chromatography. 3. The properties of the three mitochondrial malic enzyme variants were examined. No differences were found between the variants in Km for NADP, Km for pyruvate, Mn2+ and Mg2+ activation, Ki for dicumarol, heat stability, pH or ionic strength optimum.

Alleles↗