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Biomedical subjects

C Anderson

Publications and source records attributed to C Anderson.

At least 91 records · Page 5Linked to original sources

Blood pressure reduction and risk of dementia in patients with stroke: rationale of the dementia assessment in PROGRESS (Perindopril Protection Against Recurrent Stroke Study). PROGRESS Management Committee.

High blood pressure is a known risk factor for multi-infarct dementia, a subtype of dementia caused by the occurrence of several strokes. However, this form of dementia is relatively uncommon and the influence of blood pressure on the risk of other subtypes of vascular dementia remains to be clarified. Furthermore, recent studies have suggested that vascular risk factors could also play a part in Alzheimer's disease. One of the aims of Perindopril Protection Against Recurrent Stroke Study (PROGRESS) is to test the hypothesis that blood pressure decreasing treatment based on perindopril would reduce the incidence of dementia among patients with cerebrovascular disease. The dementia procedures in PROGRESS involve a classical two-phase design, with an initial screening phase based mainly on the Mini-Mental State Examination - a simple, brief, and widely used screening test for dementia. The second phase involves a diagnostic assessment for dementia in individuals screened as positive according to the criteria of the American Psychiatric Association's Diagnostic and statistical manual of mental disorders (4th ed.). In this project, two other domains of the relationship between vascular risk factors and cognition are being explored in relation to PROGRESS substudies. The apolipoprotein E polymorphism, a genetic risk factor for Alzheimer's disease, is being determined in each patient, as part of the genetic substudy. This will allow study of the relationship between this polymorphism and blood pressure, and of the effect of blood pressure decreasing treatment on the risk of dementia. The magnetic resistance imaging substudy will improve understanding of the relationship between blood pressure decreasing and the occurrence of cerebral white matter lesions, which are known to be related to cognitive decline and dementia.

Aged↗

A novel mitochondrial DNA-like sequence in the human nuclear genome.

We describe here a nuclear mitochondrial DNA-like sequence (numtDNA) that is nearly identical in sequence to a continuous 5842 bp segment of human mitochondrial DNA (mtDNA) that spans nucleotide positions 3914 to 9755. On the basis of evolutionary divergence among modern primates, this numtDNA molecule appears to represent mtDNA from a hominid ancestor that has been translocated to the nuclear genome during the recent evolution of humans. This numtDNA sequence harbors synonymous and nonsynonymous nucleotide substitutions relative to the authentic human mtDNA sequence, including an array of substitutions that was previously found in the cytochrome c oxidase subunit 1 and 2 genes. These substitutions were previously reported to occur in human mtDNA, but subsequently contended to be present in a nuclear pseudogene sequence. We now demonstrate their exclusive association with this 5842-bp numtDNA, which we have characterized in its entirety. This numtDNA does not appear to be expressed as a mtDNA-encoded mRNA. It is present in nuclear DNA from human blood donors, in human SH-SY5Y and A431 cell lines, and in rho(0) SH-SY5Y and rho(0) A431 cell lines that were depleted of mtDNA. The existence of human numtDNA sequences with great similarities to human mtDNA renders the amplification of pure mtDNA from cellular DNA very difficult, thereby creating the potential for confounding studies of mitochondrial diseases and population genetics.

Cell Nucleus↗

Male homosexuality: absence of linkage to microsatellite markers at Xq28.

Several lines of evidence have implicated genetic factors in homosexuality. The most compelling observation has been the report of genetic linkage of male homosexuality to microsatellite markers on the X chromosome. This observation warranted further study and confirmation. Sharing of alleles at position Xq28 was studied in 52 gay male sibling pairs from Canadian families. Four markers at Xq28 were analyzed (DXS1113, BGN, Factor 8, and DXS1108). Allele and haplotype sharing for these markers was not increased over expectation. These results do not support an X-linked gene underlying male homosexuality.

Alleles↗

Dietary factors in Parkinson's disease: the role of food groups and specific foods.

PURPOSE: The association between self-reported past food intake and Parkinson's disease (PD) was investigated in a case-control study of men and women aged 40-89 years. METHODS: Newly diagnosed idiopathic PD cases were ascertained from neurologists, and from outpatient and pharmacy computerized databases, at the Group Health Cooperative (GHC) clinics in the Puget Sound region of Washington state. Control subjects were chosen from the GHC patient roster and had no reported history of diagnosed neurodegenerative disease. Dietary data were obtained from structured questionnaires. RESULTS: An increase in PD risk with increasing intake was noted for foods that contain animal fat and foods containing vitamin D. Intake of fruits, vegetables, meats, bread and cereals, or foods containing vitamins A, C, E, or iron was not significantly related to PD risk. Vitamin use, in general, was also not found to be related to PD risk, although a significant trend of increasing risk of PD was noted for intake of vitamin A supplements. CONCLUSIONS: Although these data support previous findings of no association of past intake with most food groups and PD risk, they confirm an increased risk of PD associated with foods containing animal fat.

Adult↗

Lack of significant treatment effect of plasma exchange in the treatment of drug-induced toxic epidermal necrolysis?

OBJECTIVE: Comparison of outcome in patients with toxic epidermal necrolysis (TEN) in patients who received plasma exchange (PE) compared with the results in two other centres that used almost identical treatment protocols but without PE. DESIGN: Retrospective comparative case series with two recently published case series serving as controls. SETTING: National burns intensive care unit (ICU) and Department of Transfusion Medicine at Linköping University Hospital, Sweden. PATIENTS: 8 consecutive patients admitted with TEN who received PE during 1987-1997. INTERVENTIONS: Neither prophylactic antibiotics nor cortisone were used. The patients were given a median of 5.5 PE treatments (range 1-8). RESULTS: Eight patients with a median (range) age of 45 years (5-89) and with a median skin involvement total body surface area (TBSA) of 38% (12-100) were treated. The length of stay in the burns ICU was 15 (13-25) days and the time from onset of the cutaneous signs until complete re-epithelialisation was 24 days (13-55) for the seven survivors. Five patients fulfilled the diagnostic criteria of sepsis. One patient with extensive ischaemic cardiac disease developed septic shock and died (mortality 12.5%). Two patients developed side effects from PE. CONCLUSIONS: To our knowledge, this is the largest series yet presented using PE in the treatment of TEN. Our results, in patients with less cutaneous involvement, similar causative agents, and similar demographic data as in the other two studies (controls), were no different as far as mortality, length of stay, or time to re-epithelialisation were concerned. This finding does not support the use of PE in the treatment of TEN.

Adolescent↗

Genome-wide scanning for type 2 diabetes susceptibility in Canadian Oji-Cree, using 190 microsatellite markers.

We undertook a genome-wide scan using 190 markers with an average separation of 20 cM in 49 Canadian Oji-Cree sib pairs affected with type 2 diabetes. Four of these markers, one each on chromosomes 6, 8, 16, and 22, showed both suggestive linkage and suggestive association with type 2 diabetes in the Oji-Cree. None of these markers corresponded to any chromosomal region or marker that has so far been linked with type 2 diabetes in other populations. Thus, there might be several genetic loci that confer susceptibility to type 2 diabetes in this study sample. We are following up on these preliminary leads by increasing the density of the markers within these linked and associated regions, and also by increasing the number of study subjects. Also, we found instances in which there were wide disparities between the Oji-Cree and reference Caucasians with respect to marker heterozygosity. This suggests that a particular set of markers for genome-wide scanning will have different informativeness in different ethnic groups. Thus, different marker sets will likely be required for different ethnic groups in order to maximize their information content for linkage calculations.

Adult↗

Gender differences in chronic disease risk behaviors through the transition out of high school.

BACKGROUND: Major life transitions (e.g., graduation from high school) are times when many changes occur in a person's social and physical environment. Men and women likely experience aspects of these changes differently. As a result, health-related behaviors likely change at these times with possible differences in these changes by gender. METHODS: Gender differences in the performance of chronic disease risk-related behaviors (fruit, juice, and vegetable intake; physical activity; tobacco and alcohol use; and sexual practices) through the transition out of high school (HS) were assessed in a secondary analysis of a nationally representative sample from the 1992 National Health Interview Survey-Youth Risk Behavior Survey. The survey was completed by 5881 young people aged 14 to 21 years. Regression discontinuity analysis with piecewise regression was performed. RESULTS: Statistically significant gender by transition effects were obtained for exercise/physical activity (decreases at the transition point for males), snuff use (decrease for females in HS), binge drinking and number of days drinking alcohol (increases for males at the transition point), and use of alcohol or drugs before sexual intercourse (decrease for females post HS). Fruit intake decreased for males and females and daily and heavy cigarette smoking increased during the HS years. Effect sizes were small but promising, given that the data set was not designed to test this hypothesis. CONCLUSION: These data offer evidence of differences by gender in chronic disease risk behaviors through the HS transition. Longitudinal studies are needed to assess the true nature of these differences, the tracking of these risk behaviors and their personal, social, and environmental determinants, including gender-specific determinants, that may explain these changes and inform future intervention development.

Adolescent↗

A collaborative regional ocular anesthesia training program: successes and failures.

STUDY OBJECTIVE: To describe a collaborative effort of the departments of ophthalmology and anesthesiology to teach anesthesiology residents regional ocular anesthesia; to detect any differences in positive or negative outcomes after blocks performed by anesthesiology residents versus blocks performed by ophthalmology residents. DESIGN: Prospective descriptive, study. SETTING: Outpatient surgery in a university-affiliated veterans affairs hospital. PATIENTS: 614 patients requiring elective ocular surgery. INTERVENTIONS: Outcomes from patients who underwent regional anesthesia performed by ophthalmology residents were compared to outcomes from patients who received anesthesia from anesthesiology residents. MEASUREMENTS AND MAIN RESULTS: A detailed description of the collaborative teaching program in ocular anesthesia is presented. Ophthalmology residents performed the majority of regional ocular blocks (87% vs. 13%). There was no statistical difference in the incidence of negative outcomes, such as retrobulbar hemorrhage, between ophthalmology residents and anesthesiology residents (3/534 vs. 1/80) or in the incidence of successful blocks (90% for ophthalmology residents vs. 88% for anesthesiology residents). CONCLUSIONS: Regional ocular anesthetic techniques can be safely and successfully taught to residents in anesthesiology.

Ambulatory Surgical Procedures↗

Implementing smoking policies within trusts: nurses' perceptions and views of effectiveness and implications.

AIM: This study set out to explore nurses' views and perceptions of their hospital Trust's smoking policy, and the effects that it has had on both staff and patients. BACKGROUND: Although soliciting and considering the views and perceptions of staff during smoking policy development increases the likelihood of effective implementation, such activity does not appear to be routinely undertaken within the NHS. METHODS: Semistructured interviews were conducted with seven surgical nurses working within one district general hospital in the UK. RESULTS: While all of the subjects acknowledged the value of there being a smoking policy, they felt that their Trust's policy placed nurses in a powerless and vulnerable position, with little support available to help effectively address the problems that smoking raised for them and their patients. CONCLUSIONS: NHS Trusts that wish to develop and implement effective smoking policies should engage their staff throughout the process, and not underestimate the positive contribution that they all can make.

Adult↗

G-protein beta3 subunit gene splice variant and body fat distribution in Nunavut Inuit.

The GNB3 825T allele encodes a product that has enhanced activation of heterotrimeric G proteins in vitro and could play a role in adipogenesis. We therefore evaluated the possibility that the GNB3 825T allele was associated with obesity in a sample of 213 healthy Canadian Inuit. We found that body weight, body mass index, waist girth, hip girth, subscapular skinfold thickness, and triceps skinfold thickness were significantly higher in subjects with the GNB3 825T/T genotype than in subjects with other genotypes. Furthermore, two anthropometric ratios, namely that of waist to hip circumference and that of subscapular to triceps skinfold thickness, were not significantly different across genotypes. This suggested that the increased deposition of fat in subjects with the GNB3 825T/T genotype was generalized and not localized to particular subregions. There was no association of this genetic variation with blood pressure. The GNB3 825T/T genotype accounted for between 1.6% and 3.3% of the total variation (< or =13% of attributable variation) of the obesity-related traits. The potential for a genetic marker of obesity creates opportunities for future studies in the Inuit, not just to confirm the associations, but also to examine prospectively the influence of interventions and possible relationships between GNB3 825T and longer term complications of obesity.

Adolescent↗

Acetone has anti-inflammatory effects on experimental contact reactions.

The effects of a topically applied corticosteroid and its acetone vehicle on experimental allergic, toxic and irritant reactions are presented. The corticosteroid budesonide in acetone or acetone alone was applied to reactions immediately after and at different time intervals within the 1st h after provocation. Classical naked eye observation was performed and the dermal cellular infiltrate was differentiated and counted using a previously well-characterized method. "Treatment", whether with the steroid in acetone or acetone alone, had anti-inflammatory effects. For all reaction types, erythema and oedema diminished and a significant decrease in mononuclear cells was seen, when application occurred within the first 5 min after provocation. The effects were most marked for the toxic reaction to croton oil, the steroid and the vehicle being anti-inflammatory to the same extent. Application up to 60 min after provocation had anti-inflammatory effects for this reaction type. The mechanisms of acetone's anti-inflammatory effects are at present unclear. One possible explanation is that intercellular lipid organisation and, by extension, cellular membrane lipid organisation, are altered, influencing membrane receptor function. Possible anti-inflammatory effects of acetone should be considered in experimental and perhaps even clinical situations. Further investigation of the therapeutic possibilities of the finding seems warranted.

Acetone↗

Methamphetamines: use and trafficking in the Tucson-Nogales area.

A national increase in the use of methamphetamine, a cheap, accessible, and dangerous drug, prompted the National Institute on Drug Addiction to sponsor an ethnographic study in the Tucson-Nogales area. This area has experienced a rapid rise in methamphetamine (also known as meth, speed, crank, smoke, or crystal ice) use during the past 3 years. Mexican and Canadian borders are ports of entry for meth and precursor substances, and home manufacturing has increased substantially. The dual consequences of overdose and addiction result in devastating long-term psychological and physiological problems. Increased law enforcement and citizen awareness in controlling the "epidemic" are key elements in curbing the problem.

Adult↗

Assay to detect inhibitory substances in serum of patients with acute liver failure.

Patients with acute liver failure accumulate toxic substances in the circulation which may impair recovery of hepatic function. The aim of this study was to test an in vitro assay to detect inhibitory substances in the serum of patients with acute liver failure. Human liver-derived HepG2 cells were incubated for 24h in 96 well plates (30,000 cells/well) with sera (10%) from 24 patients with acute liver failure due to paracetamol overdose or NANB hepatitis and 11 normal controls. DNA synthesis was determined from the incorporation of 3H-thymidine and cell viability by the metabolism of the tetrazolium dye MTS. HepG2 cells exposed to acute liver failure sera incorporated significantly less 3H-thymidine (median 30% of control, range 0.2-169%) than normal sera (100%, 76-133%, p=0.002). Cell viability was also reduced (75%, 33-112% vs 100%, 96-105%, p<0.001). There was no correlation between these values and patient outcome or levels of plasma TNF-alpha or serum interferon-gamma. The assay detected inhibitory substances in sera of patients with acute liver failure and could be used to monitor the use of liver support systems.

Acetaminophen↗