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Biomedical subjects

B Gibson

Publications and source records attributed to B Gibson.

At least 37 records · Page 2Linked to original sources

A fetal fatty-acid oxidation disorder as a cause of liver disease in pregnant women.

BACKGROUND: Acute fatty liver of pregnancy and the HELLP syndrome (hemolysis, elevated liver-enzyme levels, and a low platelet count) are serious hepatic disorders that may occur during pregnancy in women whose fetuses are later found to have a deficiency of long-chain 3-hydroxyacyl-coenzyme A (CoA) dehydrogenase. This enzyme resides in the mitochondrial trifunctional protein, which also contains the active site of long-chain 2,3-enoyl-CoA hydratase and long-chain 3-ketoacyl-CoA thiolase. We undertook this study to determine the relation between mutations in the trifunctional protein in infants with defects in fatty-acid oxidation and acute liver disease during pregnancy in their mothers. METHODS: In 24 children with 3-hydroxyacyl-CoA dehydrogenase deficiency, we used DNA amplification and nucleotide-sequence analyses to identify mutations in the alpha subunit of the trifunctional protein. We then correlated the results with the presence of liver disease during pregnancy in the mothers. RESULTS: Nineteen children had a deficiency only of long-chain 3-hydroxyacyl-CoA dehydrogenase and presented with hypoketotic hypoglycemia and fatty liver. In eight children, we identified a homozygous mutation in which glutamic acid at residue 474 was changed to glutamine. Eleven other children were compound heterozygotes, with this mutation in one allele of the alpha-subunit gene and a different mutation in the other allele. While carrying fetuses with the Glu474Gln mutation, 79 percent of the heterozygous mothers had fatty liver of pregnancy or the HELLP syndrome. Five other children, who presented with neonatal dilated cardiomyopathy or progressive neuromyopathy, had complete deficiency of the trifunctional protein (loss of activity of all three enzymes). None had the Glu474Gln mutation, and none of their mothers had liver disease during pregnancy. CONCLUSIONS: Women with acute liver disease during pregnancy may have a Glu474Gln mutation in long-chain hydroxyacyl-CoA dehydrogenase. Their infants are at risk for hypoketotic hypoglycemia and fatty liver.

3-Hydroxyacyl CoA Dehydrogenases↗

Molecular heterogeneity in very-long-chain acyl-CoA dehydrogenase deficiency causing pediatric cardiomyopathy and sudden death.

BACKGROUND: Genetic defects are being increasingly recognized in the etiology of primary cardiomyopathy (CM). Very-long-chain acyl-CoA dehydrogenase (VLCAD) catalyzes the first step in the beta-oxidation spiral of fatty acid metabolism, the crucial pathway for cardiac energy production. METHODS AND RESULTS: We studied 37 patients with CM, nonketotic hypoglycemia and hepatic dysfunction, skeletal myopathy, or sudden death in infancy with hepatic steatosis, features suggestive of fatty acid oxidation disorders. Single-stranded conformational variance was used to screen genomic DNA. DNA sequencing and mutational analysis revealed 21 different mutations on the VLCAD gene in 18 patients. Of the mutations, 80% were associated with CM. Severe CM in infancy was recognized in most patients (67%) at presentation. Hepatic dysfunction was common (33%). RNA blot analysis and VLCAD enzyme assays showed a severe reduction in VLCAD mRNA in patients with frame-shift or splice-site mutations and absent or severe reduction in enzyme activity in all. CONCLUSIONS: Infantile CM is the most common clinical phenotype of VLCAD deficiency. Mutations in the human VLCAD gene are heterogeneous. Although mortality at presentation is high, both the metabolic disorder and cardiomyopathy are reversible.

Acyl-CoA Dehydrogenase, Long-Chain↗

The role of the dental nurse in general practice.

Dental nurses have reported dissatisfaction with their work which is associated with feelings of lack of control and being undervalued. This paper examines some of the possible reasons behind job dissatisfaction with illustrations from a pilot study conducted in general dental practice.

Attitude of Health Personnel↗

Very long chain acyl coenzyme A dehydrogenase deficiency in a 5-month-old Korean boy: identification of a novel mutation.

A 5-month-old Korean boy who presented with lethargy and cardiomyopathy was diagnosed with very long chain acyl coenzyme A dehydrogenase (VLCAD) deficiency by organic acid, fatty acid, acylcarnitine, and molecular genetic analysis. The patient was a compound heterozygote for mutations in the VLCAD gene. One allele contains a 3-bp deletion in exon 6, deleting glutamic acid in codon 130 (E130del ); this allele is of paternal origin. The patient's maternally derived allele is a novel mutation, C1843T in exon 20, which creates a premature termination codon (R615stop ). Although molecular genetic characterization of VLCAD deficiency is limited to a few patients, heterogeneity of mutations is already apparent. However, the E130del is a relatively frequent mutant allele, which has been noted in 2 previously identified patients. The 2 mutant alleles in our patient appear to be responsible for his severe and fatal clinical manifestations.

Acyl-CoA Dehydrogenase, Long-Chain↗

Inherited long-chain 3-hydroxyacyl-CoA dehydrogenase deficiency and a fetal-maternal interaction cause maternal liver disease and other pregnancy complications.

Fetal-maternal interactions are critical determinants of maternal health during pregnancy and perinatal outcome. This review explores the causative relationship of a fetal disorder of mitochondrial fatty acid oxidation, long-chain 3-hydroxyacyl-CoA dehydrogenase (LCHAD) deficiency, and the serious maternal liver diseases of pregnancy-preeclampsia, the HELLP syndrome (hemolysis, elevated liver enzymes, and low platelet counts), and acute fatty liver of pregnancy. Features of the metabolic adaptation necessitated during the fetal-neonatal transition; common phenotypes of pediatric fatty acid oxidation disorders, including neonatal hypoketotic, hypoglycemia and hepatic crisis; and clinical abnormalities of HELLP and acute fatty liver of pregnancy are presented. Evidence that a common mutation in the alpha-subunit (LCHAD) of trifunctional protein, E474Q, is always one of the mutant alleles in fetal isolated LCHAD deficiency associated with these disorders of pregnancy that cause high maternal, fetal, and newborn morbidity and mortality is reviewed. Recommendations for molecular testing for LCHAD deficiency in families with life-threatening maternal liver disease are given.

3-Hydroxyacyl CoA Dehydrogenases↗

Mild trifunctional protein deficiency is associated with progressive neuropathy and myopathy and suggests a novel genotype-phenotype correlation.

Human mitochondrial trifunctional protein (TFP) is a heterooctamer of four alpha- and four beta-subunits that catalyzes three steps in the beta-oxidation spiral of long-chain fatty acids. TFP deficiency causes a Reye-like syndrome, cardiomyopathy, or sudden, unexpected death. We delineated the molecular basis for TFP deficiency in two patients with a unique phenotype characterized by chronic progressive polyneuropathy and myopathy without hepatic or cardiac involvement. Single-stranded conformation variance and nucleotide sequencing identified all patient mutations in exon 9 of the alpha-subunit. One patient is homozygous for the T845A mutation that substitutes aspartic acid for valine at residue 246. The second patient is a compound heterozygote for the T914A that substitutes asparagine for isoleucine at residue 269 and a C871T that creates a premature termination at residue 255. Allele-specific oligonucleotide hybridization studies revealed undetectable levels of the mRNA corresponding to the mutant allele carrying the termination codon. This study suggests a novel genotype-phenotype correlation in TFP deficiency; that is, mutations in exon 9 of the alpha-subunit, which encodes a linker domain between the NH2-terminal hydratase and the COOH-terminal 3-hydroxyacyl-CoA dehydrogenase, result in a unique neuromuscular phenotype.

Adolescent↗

Reduced energy expenditure in preobese children treated for acute lymphoblastic leukemia.

Children with acute lymphoblastic leukaemia (ALL) typically gain weight at excessive rates during and after therapy, and a high proportion of young adult survivors are obese. Previous studies have failed to identify the abnormalities in energy balance that predispose these children to obesity. The aim of this study was to determine the cause of excess weight gain in children treated for ALL by testing the hypothesis that energy expenditure is reduced in these patients. Twenty children [9 boys, 11 girls; mean age 10.9 (3.2) y] treated for ALL who had shown excess weight gain, but were not obese [mean body mass index SD score 0.70 (1.04)], were closely and individually matched with 20 healthy control children [9 boys, 11 girls; mean age 10.7 (3.0) y; mean body mass index SD score 0.27 (0.91)]. In each child we measured total energy expenditure by doubly-labeled water method, resting energy expenditure, energy expended on habitual physical activity, and energy intake. Total energy expenditure was significantly higher in control subjects than in patients: mean paired difference 1185 kJ/d (282 kcal/d), 95% confidence interval (CI) 218-2152. This difference was largely due to reduced energy expended on habitual physical activity in the patients. Resting energy expenditure was lower in the patients: mean paired difference 321 kJ/d (76 kcal/d), 95% CI 100-541. Energy intake was also lower in the patients: mean paired difference 1001 kJ/d (238 kcal/d), 95% CI 93-1909. Children treated for ALL are predisposed to excess weight gain, and subsequently obesity, by reduced total energy expenditure secondary to reduced habitual physical activity. Prevention of obesity in ALL should focus on modest increases in habitual physical activity, modest restriction of dietary intake, and monitoring of excess weight gain.

Adult↗

Venous leg ulcers. Part 4: Wound care.

When assessing a leg ulcer the nurse should note the size and site of the wound, any exudate present and the presence of pain and allergies. A suitable wound dressing can then be selected.

Bandages↗

Deaf adolescents' knowledge of AIDS. Grade and gender effects.

Adolescents attending 5 state schools for the deaf responded to a 35-item questionnaire designed to probe their knowledge of AIDS. The 129 students in grades 9-12 had extremely limited core knowledge of AIDS, with the correct answers to only 8 of the 35 questions known by most students in all 4 grades. A minority of males and females knew the answers to most questions, indicating that AIDS education programs for deaf adolescents are urgently needed.

Acquired Immunodeficiency Syndrome↗

Accessing primary dental care in three London boroughs.

OBJECTIVE: To investigate and identify factors that may influence individuals' ability to access primary health care services. DESIGN: Cross-sectional study SETTING: Lambeth, Southwark and Lewisham. SUBJECTS: A 0.1 per cent random sample of people aged 18 years and over in the population of 626,621 people in the three boroughs. MAIN OUTCOME MEASURES: Demographic as well as psychosocial profile of the sample, perceptions of their dental health needs, accessed dental care. RESULTS: The results indicated that people believed that their oral health was good. The majority of the sample had attended for dental care within the previous year and were registered with a general dental practitioner. Accessing dental care was related to age, social class, borough of residence, dentate status and dental phobia status. In addition subjects experiencing problems with their teeth gained access to care more readily than others. This was related to social class. Accessing dental care was predicted by dental care being provided by a general dental practitioner, experiencing problems with teeth and not being dentally phobic. CONCLUSIONS: The findings suggest that psychosocial factors together with dental health status can act as determinants when accessing primary dental services. It is considered that family health services authorities should be aware of these influences when developing and monitoring dental health services, in order to make them responsive and sensitive to the needs of the people whom they serve.

Adolescent↗

Tough tobacco-control legislation begins to have an impact in Ontario.

In 1994 the Ontario government passed one of the world's toughest packages of antitobacco legislation. The Tobacco Control Act places restrictions on who can sell tobacco products, provides for severe penalties for retailers who sell to minors, bans smoking in many public places and severely restricts the use of designated smoking areas in others. The province has had antismoking legislation before, but enforcement was lax; this time enforcement of the law, particularly as it concerns retailers who sell to minors, has been given priority Brenda Gibson asks if these tough new measures are working.

Commerce↗

Aspergillosis in immunocompromised paediatric patients: associations with building hygiene, design, and indoor air.

BACKGROUND: Nosocomial aspergillosis is a well known complication of immunosuppression in cancer patients and those undergoing transplantation and has usually been associated with major building construction or demolition. An observational study is reported of the hospital environment associated with an outbreak of aspergillosis in a paediatric oncology ward. METHODS: All cases of aspergillosis were identified from the hospital records and categorised as definite or probable according to the extent of supportive clinical and laboratory findings. All relevant aspects of building ventilation, air filtration, and aerosol generation considered relevant were examined and air samples for fungi were taken in triplicate at 25 sites using a slit sampler with appropriate culture media. RESULTS: Six cases of aspergillosis were identified over one year out of the 148 patients who attended the unit - the only part of the hospital where cases were found. Examination of the building services and function suggested that the cause or source was isolated to this paediatric oncology/haematology ward and may have been attributed to a defective disposal conduit door as well as the dispersal of a contaminated aerosol from the ward vacuum cleaner which had the highest measured concentrations of Aspergillus fumigatus in or around the building (65 colony forming units (cfu)/m3 compared with 0-6 cfu/m3 elsewhere). No further cases were identified in the two years after these hygiene arrangements were changed. CONCLUSIONS: The investigation of this outbreak of nosocomial aspergillosis identified several possible sources of fungally contaminated aerosol which could have been implicated as the cause. Their modification was followed by a reduction in the incidence of further cases. Each should be incorporated as an issue of importance in hospital building design and hygiene.

Air Pollution, Indoor↗

Volunteers, doctors take palliative care into the community.

The face of palliative care is changing. In Ontario's St. Catharines region there has been a concerted effort to make it more of a community-based procedure. A local college even teaches a 2-year course in palliative care. The trend is expected to continue because Canadians are living longer, and more frail elderly people will be dying at home. Dr. Sandra Hartman, a palliative-care consultant, says physicians interested in palliative care must remember that there is more to it than providing medical assistance. She considers bereavement counseling for the patient's family a necessary part of follow-up preventive care.

Aged↗