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Biomedical subjects

K Green

Publications and source records attributed to K Green.

At least 37 records · Page 2Linked to original sources
PubMed2002

Hospitalized anorexics and resistance training: impact on body composition and psychological well-being. A preliminary study.

Ritualised exercise commonly accompanies the clinical presentation of anorexia nervosa (AN) sufferers, but there is a paucity of research on structured exercise as a therapeutic intervention. This study examined the usefulness of resistance training as part of a treatment programme for hospitalized anorexics. The study sample consisted of 21 subjects: seven anorexics participating in the exercise programme, seven non-participating anorexics, and seven subjects unaffected by an eating disorder but who participated in the exercise programme. The results show that resistance training is associated with an improvement in body composition and psychological well-being and, although it does not confer an outcome advantage in this regard, it seems to be a useful adjunct in the treatment of hospitalized anorexics.

Adaptation, Psychological↗
PubMed2002

Hartnup disorder: polymorphisms identified in the neutral amino acid transporter SLC1A5.

Hartnup disorder is an inborn error of renal and gastrointestinal neutral amino acid transport. The cloning and functional characterization of the 'system B0' neutral amino acid transporter SLC1A5 led to it being proposed as a candidate gene for Hartnup disorder. Linkage analysis performed at 19q13.3, the chromosomal position of SLC1A5, was suggestive of an association with the Hartnup phenotype in some families. However, SLC1A5 was not linked to the Hartnup phenotype in other families. Linkage analysis also excluded an alternative candidate region at 11q13 implicated by a putative mouse model for Hartnup disorder. Sequencing of the coding region of SLC1A5 in Hartnup patients revealed two coding region polymorphisms. These mutations did not alter the predicted amino acid sequence of SLC1A5 and were considered unlikely to play a role in Hartnup disorder. There were no mutations in splice sites flanking each exon. Quantitative RT-PCR of SLC1A5 messenger RNA in affected and unaffected subjects did not support systemic differences in expression as an explanation for Hartnup disorder. In the six unrelated Hartnup pedigrees studied, examination of linkage at 19q13.3, polymorphisms in the coding sequence and quantitation of expression of SLC1A5 did not suffice to explain the defect in neutral amino acid transport.

Amino Acid Transport System ASC↗
PubMed2002

A cautionary tale on ancient migration detection: mitochondrial DNA variation in Santa Cruz Islands, Solomon Islands.

Over the past decade, the origin of the first Malayo-Polynesian settlers of the island Pacific has become a contentious issue in molecular anthropology as well as in archaeology and historical linguistics. Whether the descendants of the ancestral Malayo-Polynesian speakers moved rapidly through Indonesia and Island Melanesia in a few hundred years, or whether they were the product of considerable intermingling within the more westerly part of the latter region, it is widely accepted that they were the first humans to colonize the distant Pacific islands beyond the central Solomon Islands approximately 3,000 years ago. The Santa Cruz Islands in the Eastern Solomons would have most likely been the first in Remote Oceania to be colonized by them. Archaeologically, the first Oceanic Austronesian settlement of this region appears to have been overlain by various later influences from groups farther west in a complex manner. Molecular anthropologists have tended to equate the spread of various Austronesian-speaking groups with a particular mitochondrial variant (a 9-base-pair [bp] deletion with specific D-loop variants). We have shown before that this is an oversimplified picture, and assumed that the Santa Cruz situation, with its series of intrusions, would be informative as to the power of mitochondrial DNA haplotype interpretations. In the Santa Cruz Islands, the 9-bp deletion is associated with a small number of very closely related hypervariable D-loop haplotypes resulting in a star-shaped Bandelt median network, suggesting a recent population expansion. This network is similar to Polynesian median networks. In a pairwise mismatch comparison, the Santa Cruz haplotypes have a bimodal distribution, with the first cluster being composed almost entirely of the 9-bp-deleted haplotypes-again attesting to their recent origins. Conversely, the nondeleted haplogroups bear signatures of more ancient origins within the general region. Therefore, while the profiles of the two sets of haplotypes indicate very distinctive origins in different populations with divergent expansion histories, the sequence of their introduction into the Santa Cruz Islands clearly does not follow simply.

DNA, Mitochondrial↗
PubMed2001

The evolution of methicillin-resistant Staphylococcus aureus in Canadian hospitals: 5 years of national surveillance.

BACKGROUND: To better understand the epidemiology of methicillin-resistant Staphylococcus aureus (MRSA) in Canadian hospitals, surveillance has been conducted in sentinel hospitals across the country since 1995. We report the results of the first 5 years of the program. METHODS: For each newly identified inpatient with MRSA, medical records were reviewed for demographic and clinical data. Isolates were subjected to susceptibility testing and molecular typing by pulsed-field gel electrophoresis. RESULTS: A total of 4507 patients infected or colonized with MRSA were identified between January 1995 and December 1999. The rate of MRSA increased each year from a mean of 0.95 per 100 S. aureus isolates in 1995 to 5.97 per 100 isolates in 1999 (0.46 per 1000 admissions in 1995 to 4.12 per 1000 admissions in 1999) (p < 0.05). Most of the increase in MRSA occurred in Ontario, Quebec and the western provinces. Of the 3009 cases for which the site of MRSA acquisition could be determined, 86% were acquired in a hospital, 8% were acquired in a long-term care facility and 6% were acquired in the community. A total of 1603 patients (36%) were infected with MRSA. The most common sites of infection were skin or soft tissue (25% of MRSA infections), pulmonary tissues (24%) and surgical sites (23%); 13% of the patients were bacteremic. An epidemiologic link with a previously identified MRSA patient was suspected in 53% of the cases. Molecular typing indicated that most (81%) of the isolates could be classified as related to 1 of the 4 Canadian epidemic strains of MRSA. INTERPRETATION: There has been a significant increase in the rate of isolating MRSA in many Canadian hospitals, related to the transmission of a relatively small number of MRSA strains.

Adolescent↗
PubMed2001

Myroides odoratus cellulitis and bacteremia: case report and review.

A case of Myroides odoratus cellulitis with bacteremia in an apparently immunocompetent man is presented. Although common in soil and water, this agent is a rare clinical isolate and is often not considered pathogenic. The virulence of M. odoratus may be greater than is currently believed and it should be considered in bacteremias from cutaneous sources in immunocompetent patients.

Adult↗
PubMed2001

The Saskatchewan dissemination story.

The Saskatchewan Heart Health Program (SHHP) Dissemination Phase "Building Health Promotion Capacity" is a five-year program funded by Health Canada, Saskatchewan Health and the Heart and Stroke Foundation of Saskatchewan. This phase began in July 1998 and builds on two previous SHHP phases: the provincial heart health survey (Saskatchewan Health, 1990), and the community demonstration projects (SHHP, 1998a, b, c, d). The evolution of the SHHP has occurred in a dynamic provincial context. Saskatchewan is a Canadian prairie province of one million people with most living in the southern and central parts of the province. The population is ageing and urbanizing, and the economy is shifting away from agricultural production toward a diversified service sector. In 1993, health reform created 30 Districts in southern and central Saskatchewan; the formation of three northern Districts followed five years later. All but two Districts are rural-based. Population served ranges from 2,261 to 237,274; total area ranges from 4,019 to 133,900 square kilometers.

Cardiovascular Diseases↗
PubMed2000

Increased circulating lipid peroxides in severe preeclampsia activate NF-kappaB and upregulate ICAM-1 in vascular endothelial cells.

Preeclampsia is a systemic disease of pregnancy characterized by maternal hypertension, proteinuria, and edema. These clinical pathological findings may be attributed to abnormalities in vascular endothelial activation secondary to increased oxidative stress. To test the hypothesis that increased circulating lipid peroxides in preeclamptic women activate vascular endothelial cells, we determined NF-kappaB transcriptional activity and ICAM-1 expression in human umbilical vein endothelial cells (HUVEC) cultured with plasma from women with severe preeclampsia (preeclamptic plasma, N = 12) or plasma from normal pregnancies (normal plasma, N = 12). Preeclamptic women had increased circulating lipid peroxides compared with normal pregnant women, as demonstrated by a 4.5-fold higher concentration of plasma malondialdehyde (PkB luciferase reporter construct transfected into HUVEC, preeclamptic plasma was found to up-regulate HUVEC NF-kappaB activity by 2.5-fold when compared with normal plasma (PkB activation in response to preeclamptic-plasma by 77% (PkB activation and ICAM-1 expression on HUVEC, which can be inhibited by vitamin E and N-acetyl-cysteine.

Antioxidants↗
PubMed2000

Host variation in cytokine responses to superantigens determine the severity of invasive group A streptococcal infection.

Cytokines elicited by superantigens have been suggested to play a central role in severe systemic clinical manifestations of gram-positive sepsis. Here we provide evidence for a potent inflammatory cytokine response in acute invasive group A streptococcal infections, and show a direct correlation between the magnitude of this response and the severity of systemic manifestations of the disease. Severe invasive cases suffering from toxic shock and/or necrotizing fasciitis had significantly higher frequencies of IL-2-, IL-6-, and TNF-alpha-producing cells in their circulation as compared to non-severe invasive cases (p=0.05-0.01). This difference was even more accentuated when severe and non-severe cases infected with a clonal M1T1 strain were compared (p=0.03-0. 004). To determine whether host factors were responsible for this difference in magnitude of cytokine responses, paired age- and gender-matched severe and non-severe M1T1 cases (n=8) were tested in vitro during their convalescent phase for immune response to superantigens produced by their infecting isolate. The results showed persistent and inherent differences in the magnitude of proliferative and cytokine responses of severe and non-severe patients to the streptococcal superantigens to which they had been exposed during infection. Thus, the study provides evidence that patients with a propensity to produce higher levels of inflammatory cytokines in response to streptococcal superantigens develop significantly more severe systemic manifestations than patients who have a propensity to produce lower levels of inflammatory cytokines to the same superantigens. We therefore conclude that host factors influence the magnitude of cytokine responses to superantigens and consequently the clinical outcome of the infection.

Cytokines↗
PubMed2000

Vancomycin prescribing practices in hospitalized chronic hemodialysis patients.

To determine the prevalence of and indications for vancomycin administration among hospitalized chronic hemodialysis patients, we performed a 3-month prospective cohort study at a tertiary care center. Modified guidelines for vancomycin use from the Hospital Infections Control Practices Advisory Committee of the Centers for Disease Control and Prevention were used. Vancomycin was administered during 56 of 144 admissions (39%) requiring chronic hemodialysis compared with 336 of 7,212 admissions (5%) not requiring hemodialysis (relative risk, 11; 95% confidence interval, 8 to 15; P < 0.001). Among chronic hemodialysis patients, vancomycin use was judged appropriate for 131 of the 164 vancomycin doses (80%). The most common appropriate indication was empiric therapy in a febrile patient before culture or susceptibility results. Of 32 infections identified in patients who received empiric vancomycin, 15 infections (47%) were caused by beta-lactam-resistant pathogens. Among the 33 doses (20%) judged inappropriate, continued therapy for a presumed infection despite failure to identify a beta-lactam-resistant pathogen was the most common indication. Although vancomycin administration was frequent among hospitalized chronic hemodialysis patients, its use was justified in the majority of cases. Efforts should focus on limiting vancomycin administration for treating infections caused by beta-lactam-sensitive pathogens.

Adult↗
PubMed2000

Percent body fat and bone mass in healthy Canadian females 10 to 19 years of age.

The primary aim of the investigation was to assess the relationship between whole-body fat expressed as a percentage of body weight with whole-body bone mineral content relative to age and anthropometry. Sixty females between 10 and 19 years of age were recruited to this cross-sectional study, which included measurements of weight and height and whole-body fat and bone mineral content using dual-energy X-ray absorptiometry. To assess bone mineral content, data were expressed as a weight or standard deviation scores using age and bone area. Relationships between outcome variables were determined using multiple correlation analysis followed by multiple linear regression with age, weight, height, and fat as predictor variables for outcomes of bone mineral content and density. Correlation analysis indicated that whole-body fat expressed as a percent was significantly related to weight (p < 0.01), but was not related to age or bone mineral content or density unless bone mineral content was corrected to age or bone area using standard deviation scores. In addition, body fat was associated with bone area for age and height (p < 0.01). However, multiple linear regression yielded opposite results. When included in regression, body fat had a negative impact on bone mineral content (p = 0.003), mineral content corrected to bone area (p = 0.02), and bone density (p = 0.003), while age, weight, and height had positive impacts on these outcome measurements. The data suggest that for younger children, the relative influence of percent body fat will be greater and could be linked with suboptimal attainment of peak bone mass. The females in this study appeared to be within reference limits for percent body fat. However, greater amounts of body fat relative to weight could be a marker for lifestyles that do not support attainment of optimal peak bone mass.

Absorptiometry, Photon↗
PubMed2000

The stethoscope in the Emergency Department: a vector of infection?

The purposes of this study were to determine whether microorganisms can be isolated from the membranes of stethoscopes used by clinicians and nurses, and to analyse whether or not the degree of bacterial colonization could be reduced with different cleaning methods. We designed a transversal before-after study in which 122 stethoscopes were examined. Coagulase negative staphylococci (which are also potentially pathogenic microorganisms) were isolated together with 13 other potentially pathogenic microorganisms, including S. aureus, Acinetobacter sp. and Enterobacter agglomerans. The most effective antiseptic was propyl alcohol. Analysis of the cleaning habits of the Emergency Department (ED) staff, showed that 45% cleaned the stethoscope annually or never. The isolation of potentially pathogenic microorganisms suggests that the stethoscope must be considered as a potential vector of infection not only in the ED but also in other hospital wards and out-patient clinics.

1-Propanol↗
PubMed2000

Effects of instructions on physical capacities outcome in a workers' compensation setting.

UNLABELLED: Physical Capacity Evaluations (PCE) are often used in Pain Management Programs (PMP) to help determine patients' return-to-work status, continued rehabilitation and compensation. STUDY DESIGN: Groups of patients participating in a 4-week PMP were given the PCE upon entry to the program and again near discharge. Change in performance between the first and second testing was examined. OBJECTIVES: The study was designed to examine the effects of instructions on patients' performance on the PCE. SUMMARY OF BACKGROUND DATA: An extensive literature suggests that, although commonly used, the PCE is of questionable validity in measuring actual physical capacity. METHODS: Patients were assigned to one of 2 physical therapists and given a PCE (in this setting, a dynamic vs static strength test) on admission and near the time of discharge. The assessment by the 2 therapists differed in the instructions they gave their patients for the PCE. Both therapists told their groups, "Do the best you can," but only one therapist added, "This test will be used to determine your job classification." In the second half of the study both therapists gave identical instructions, "Do the best you can," and did not add the explanation. RESULTS: Patients who were informed that the test would be used to determine their job classifications performed considerably worse than those not so informed. When both therapists gave the same instructions, groups performed comparably, suggesting that therapist variables did not explain the differences between the groups. CONCLUSIONS: Instructions on the PCE have an effect on performance.

Journal Article↗
PubMed2000

Pharmacology of the intraocular pressure (IOP) lowering effect of systemic dexanabinol (HU-211), a non-psychotropic cannabinoid.

The purpose of this study was to characterize the intraocular pressure (IOP) lowering activity and possible mechanism of action of the synthetic, non-psychotropic cannabinoid dexanabinol (HU-211) [(+)(3S,4S), 7-hydroxy-delta-6-tetrahydrocannabinol 1,1 dimethylheptyl], following intravenous (i.v.) administration in the rabbit. IOP (pneumatonometry), aqueous humor inflow rate (fluorophotometry), blood pressure, and heart rate (computerized physiograph system connected to central ear artery cannula) were measured in unanesthetized albino rabbits. Intravenous administration of HU-211 resulted in a dose-related reduction in IOP; a maximal IOP reduction of 5.0 +/- 0.2 mmHg was observed 4 hr after a 0.5 mg/kg dose. No significant changes in blood pressure or heart rate were observed during the first hr following this dose of HU-21 1. Pupil diameter did not change significantly during the 5 hr following the 0.5 mg/kg i.v. dose. No significant change in the rate of aqueous humor inflow occurred during the 6 hr after a 0.5 mg/kg dose of HU-211, thereby implicating outflow changes as the major source of IOP reduction. IOP reduction by HU-211 following pre-treatment with the alpha2 adrenergic antagonist, yohimbine (1 mg/kg, i.v.), was only 30% of that of HU-211 alone. IOP reduction following pretreatment with the alpha2 agonist, clonidine (0.5 mg/kg i.v.), was twice as large as that of HU-211 alone. Pretreatment with the beta-adrenergic antagonist, propranolol (0.5 mg/kg i.v.), resulted in a 50% reduction in the IOP-lowering effect of HU-211. In summary, HU-211, administered i.v., is an effective IOP-lowering agent, devoid of any significant side effects (blood pressure, heart rate or pupil diameter, all of which have been reported previously for cannabinoids). Involvement of the adrenergic system is indicated in mediating the IOP-lowering effects of HU-211 that appear to reflect a change in fluid outflow from the eye.

Animals↗
PubMed2000

Relationship between homocysteine and superoxide dismutase in homocystinuria: possible relevance to cardiovascular risk.

A modest homocysteine elevation is associated with an increased cardiovascular risk. Marked circulating homocysteine elevations occur in homocystinuria due to cystathionine beta-synthase (CbetaS) deficiency, a disorder associated with a greatly enhanced cardiovascular risk. Lowering homocysteine levels reduces this risk significantly. Because homocysteine-induced oxidative damage may contribute to vascular changes and extracellular superoxide dismutase (EC-SOD) is an important antioxidant in vascular tissue, we assessed EC-SOD and homocysteine in patients with homocystinuria. We measured circulating EC-SOD, total homocysteine (free plus bound), and methionine levels during the treatment of 21 patients with homocystinuria, 18 due to CbetaS deficiency, aged 8 to 59 years, and 3 with remethylating defects. We measured total homocysteine by immunoassay, EC-SOD by ELISA, and methionine by amino acid analysis and assessed interindividual and intraindividual relationships. There was a significant, positive relationship between EC-SOD and total homocysteine. For the interindividual assessment, levels were highly correlated, r=0.746, N=21, P<0.0001. This relationship was maintained after taking into account intraindividual patient variation (r=0.607, N=62, P<0.0001). In 2 newly diagnosed CbetaS-deficient patients, treatment that lowered the markedly elevated pretreatment homocysteine level (from 337 to 72 and from 298 to 50 micromol/L) reduced the associated elevated EC-SOD in each by 50%. EC-SOD and methionine levels were unrelated (r=0.148, n=39, P=0.368). The positive relationship between circulating EC-SOD and homocysteine could represent a protective antioxidant response to homocysteine-induced oxidative damage and contribute to reducing cardiovascular risk in homocystinuric patients. EC-SOD levels may be relevant to the pathogenesis of vascular disease in other patient groups.

Adolescent↗
PubMed2000

Invasive group A streptococcal disease in children and association with varicella-zoster virus infection. Ontario Group A Streptococcal Study Group.

OBJECTIVES: To describe the incidence and clinical features of invasive group A streptococcal (GAS) disease in children in Ontario and determine the risk of invasive GAS infection following chickenpox. METHODS: During 1992-1996, we conducted prospective, active, population-based surveillance for pediatric invasive GAS disease in Ontario, Canada (population: 11 million; 2.5 million children) and reviewed clinical and laboratory records. RESULTS: There were 1.9 cases of invasive GAS disease per 100,000 children per year. Streptococcal toxic shock syndrome (STSS) occurred in 7% of cases and necrotizing fasciitis (NF) in 4% for incidences of.08 and.13 per 100,000 per year, respectively. Case-fatality rates were 56% for STSS, 10% for NF, and 4% overall. The presence of chronic underlying illness other than asthma was associated with death (relative risk [RR]: 11; 95% confidence interval [CI]: 2.4-45). Fifteen percent of children identified had preceding chickenpox infection, which significantly increased the risk for acquisition of invasive GAS disease (RR: 58; 95% CI: 40-85). Children with invasive GAS and recent chickenpox were more likely to have NF (RR: 6.3; 95% CI: 1.8-22.3). CONCLUSIONS: Childhood invasive GAS disease occurs at an incidence similar to the adult population but has a lower rate of STSS and case-fatality. Chickenpox dramatically increases the risk for acquiring invasive GAS disease, and universal chickenpox vaccination could potentially prevent up to 15% of all pediatric invasive GAS disease.

Adolescent↗
PubMed2000

Effect of vehicle upon in vitro transcorneal permeability and intracorneal content of Delta9-tetrahydrocannabinol.

PURPOSE: To determine the transcorneal flux, and intracorneal penetration, of Delta9-tetrahydrocannabinol when presented to the isolated rabbit cornea in different vehicles. METHODS: Corneas were mounted in specular microscope chambers, with ( 3)H-Delta9-tetrahydrocannabinol on the epithelial surface in one of 15 vehicles and the endothelium perfused with Ringer. Following equilibration the perfusate was collected at 20 minute intervals and sampled for counting. After 3 hours the epithelium was harvested and the stroma/endothelium collected. The tissues were placed in distilled water and sampled at 24 hours. RESULTS: The order of efficacy of the best 6 vehicles in terms of transcorneal Delta9-tetrahydrocannabinol flux was: alpha-cyclodextrin > hydroxypropylmethylcellulose (80 to 120 centipoises)> polyvinyl alcohol > hydroxypropylmethylcellulose (3500 to 5600 centipoises)> polyvinylpyrrolidone (29 to 32 centipoises) > polyvinylpyrrolidone (12 to 18 centipoises). Remaining vehicles, including light mineral oil, corn oil, hyaluronic acid, hydroxypropyl-beta-, beta-, and gamma-cyclodextrin and hydroxypropylmethylcellulose (40 to 60 centipoises) all gave lower fluxes. The epithelium was the site of most intracorneal drug. CONCLUSIONS: Differentiation was made between several potential vehicles for in vivo topical delivery of Delta9-tetrahydrocannabinol. The vehicles include cyclodextrins and other excipients such as hydroxypropylmethylcellulose and polyvinylpyrrolidone. There is not a strong relationship between solubility or binding of the lipophilic drug by excipients and transcorneal flux. The most efficacious vehicles provided a considerably greater transcorneal drug flux than light mineral oil which previously had been shown to deliver sufficient topical Delta9-tetrahydrocannabinol to reduce intraocular pressure of several species. The new vehicles should permit greater pharmacological sequelae.

Animals↗