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Biomedical subjects

Robert Young

Publications and source records attributed to Robert Young.

At least 19 recordsLinked to original sources
PubMed2006

Prevalence of deliberate self harm and attempted suicide within contemporary Goth youth subculture: longitudinal cohort study.

OBJECTIVE: To investigate whether deliberate self harm is associated with contemporary Goth youth subculture. DESIGN: Longitudinal cohort study. SETTING: School and community based study of young people living in the Central Clydeside Conurbation, Scotland. PARTICIPANTS: 1258 people aged 19, surveyed in 2002-4 and followed-up since age 11 (1994). MAIN OUTCOME MEASURES: Lifetime prevalence of self harm and attempted suicide and their association with Goth youth subculture, before and after adjusting for confounders. RESULTS: Identification as belonging to the Goth subculture was strongly associated with lifetime self harm and attempted suicide, with a prevalence of 53% and 47%, respectively among the most highly identified group, and evidence for a dose-response relation. Adjusting for potential confounders did not significantly attenuate this association. Analysis of other youth subcultures showed that this effect was primarily associated with Goth subculture. CONCLUSIONS: Identification as belonging to the Goth subculture was the best predictor of self harm and attempted suicide. Although based on small numbers, additional longitudinal analysis suggests both selection and modelling mechanisms are involved, selection mechanisms possibly being more likely.

Adolescent↗
PubMed2006

Characteristics of 32 supercentenarians.

OBJECTIVES: To report phenotypic characteristics of 32 age-validated supercentenarians. DESIGN: Case series. SETTING: U.S.-based recruitment effort. PARTICIPANTS: Thirty-two supercentenarians. MEASUREMENTS: Multiple forms of proof were used to validate age claims. Sociodemographic, activities of daily living, and medical history data were collected. RESULTS: Age range was 110 to 119. Fifty-nine percent had Barthel Index scores in the partially to totally dependent range, whereas 41% required minimal assistance or were independent. Few subjects had a history of clinically evident vascular-related diseases, including myocardial infarction (n=2, 6%) and stroke (n=4, 13%). Twenty-two percent (n=7) were taking medications for hypertension. Twenty-five percent (n=8) had a history of cancer (all cured). Diabetes mellitus (n=1, 3%) and Parkinson's disease (n=1, 3%) were rare. Osteoporosis (n=14, 44%) and cataract history (n=28, 88%) were common. CONCLUSION: Data collected thus far suggest that supercentenarians markedly delay and even escape clinical expression of vascular disease toward the end of their exceptionally long lives. A surprisingly substantial proportion of these individuals were still functionally independent or required minimal assistance.

Activities of Daily Living↗
PubMed2006

Peer victimization and depression in early-mid adolescence: a longitudinal study.

BACKGROUND: Despite considerable evidence for psychological distress among children and young people who experience peer victimization, cross-sectional studies cannot determine the direction of the relationship. Several recent studies have examined associations between victimization and distress. The majority find evidence for both directions but do not arbitrate between them; only one prior study has attempted to do this. AIMS: To use longitudinal data to: (1) test competing hypotheses about the direction of the victimization-depression association; (2) investigate gender differences in the resulting models. SAMPLE: Data were obtained from a Scottish school-based cohort (N=2,586). METHODS: Self-completion questionnaires included a depression scale and questions on victimization at each age. RESULTS: Despite shifts in and out of victim status, there was evidence of stability in both victimization and depression. Bivariate analyses showed positive relationships between victimization and depression. Structural equation modelling (SEM) showed that at age 13, this relationship was reciprocal, with a stronger path from victimization to depression than vice versa. However, at age 15, it was almost entirely due to a path from depression to victimization among boys. Models including cross-lagged paths fitted the data less well than those including simultaneous associations. CONCLUSIONS: Current policy focuses on victimization as a cause of distress; however, professionals should be aware that vulnerable children and young people are likely to be the targets of victimization.

Adolescent↗
PubMed2006

Toward more efficient protein expression: keep the message simple.

Optimization of gene coding-sequence, including preferred codon usage and removal of cryptic splice sites and mRNA-destabilizing motifs, has been shown to improve recombinant protein production of different proteins. Here, we present data to show that gene optimization can also be used to improve the production of a complex macromolecule, namely an antibody. When applied to the heavy and light chain genes of our model antibody, we found that greater numbers of high-producing transfectants as well as increased levels of protein production were observed (approximately 1.5-fold). In this test model, production was improved even though the antibody has previously been demonstrated to give high expression in stably transfected cells (up to 5 g/L in bioreactors). Because the parental heavy chain sequence contained introns, and the process of gene optimization is most efficiently performed on sequences without introns, we demonstrated that removal of introns in the coding sequence had no effect on the quantity of antibody produced. All constructs were evaluated using Lonza's glutamine synthetase gene expression vectors in Chinese hamster ovary cells. Our findings suggest that significant improvements in product yields can be achieved by gene optimization, which may facilitate the processing and translation of gene transcripts.

Animals↗
PubMed2005

Could the peer group explain school differences in pupil smoking rates? An exploratory study.

Schools differ in the proportion of their pupils who smoke. Such differences transcend pupil intake characteristics and relate to the internal life of the school. Although adolescents' smoking behaviour has been associated with that of their peers, little consideration has been given to whether peer structures and processes contribute to school differences in pupil smoking rates. In two relatively deprived Scottish schools, one with a higher and one with a lower rate of pupil smoking, 13 and 15 year-olds were surveyed. Sociometric data and information on pupils' smoking behaviour and views were gathered. Twenty-five single-sex discussion groups were then held with a sub-sample of the 13 year-olds in order to explore in detail their views on smoking, smokers and fellow pupils. Findings showed that in the higher smoking school, pupils were more often in groups, smokers were identified as popular, and attitudes (especially among non-smoking females) were more pro-smoking. In the lower smoking school, by contrast, there were more isolates and dyads, there were no popular smokers and attitudes (especially among non-smoking females) were much less pro-smoking. Thus, evidence suggests peer group structures and related influences could be one explanation for school differences in smoking, and that the popularity of smokers together with the views of non-smoking females may be particularly important in creating such differences.

Adolescent↗
PubMed2005

Mechanisms of gastroesophageal reflux in critically ill mechanically ventilated patients.

BACKGROUND & AIMS: Gastroesophageal reflux is a major problem in mechanically ventilated patients and may lead to pulmonary aspiration and erosive esophagitis. Transient lower esophageal sphincter relaxations are the most common mechanism underlying reflux in nonventilated patients. The mechanisms that underlie reflux in critically ill ventilated patients have not been studied. The aim of this study was to determine the mechanisms underlying gastroesophageal reflux in mechanically ventilated patients in the intensive care unit. METHODS: In 15 mechanically ventilated intensive care unit patients, esophageal motility, pH, and intraluminal impedance (11/15 patients) were recorded for 1 hour before and 5 hours during continuous nasogastric feeding. RESULTS: Basal lower esophageal sphincter pressure was uniformly low (2.2 +/- 0.4 mmHg). The median (interquartile range) acid exposure (pH <4) was 39.4% (0%-100%) fasting and 32% (7.5%-94.2%) fed. Acid reflux occurred in 10 patients, but slow drifts in esophageal pH were also an important contributor to acid exposure. If esophageal pH decreased to pH <4, it tended to remain so for prolonged periods. A total of 46 acid reflux events were identified. Most (55%) occurred because of absent lower esophageal sphincter pressure alone; 45% occurred during straining or coughing. CONCLUSIONS: Gastroesophageal reflux in mechanically ventilated patients is predominantly due to very low or absent lower esophageal sphincter pressure, often with a superimposed cough or strain. These data suggest that measures that increase basal LES pressure may be useful to prevent reflux in ventilated patients.

Adult↗
PubMed2004

Cigarette access and pupil smoking rates: a circular relationship?

Adolescents obtain cigarettes from both commercial and social sources. While the relationship between commercial access and adolescent smoking has been researched, no one has considered in detail whether rates of peer smoking affect cigarette availability. In two relatively deprived Scottish schools that differed in their pupil smoking rates, we assess pupil access to cigarettes. 896 13 and 15 year olds were surveyed, and 25 single-sex discussion groups held with a sub-sample of the 13 year olds. Smokers in both schools obtained cigarettes from shops, food vans and other pupils. However, pupils in the 'high' smoking school perceived greater access to both commercial and social sources, and had access to an active 'peer market'. These findings suggest that variations in cigarette access may contribute to school differences in pupil smoking rates, and that the relationship between access and adolescent smoking is circular, with greater availability increasing rates, and higher rates enhancing access.

Adolescent↗
PubMed2004

Ultrastructure of Proteus mirabilis swarmer cell rafts and role of swarming in catheter-associated urinary tract infection.

Proteus mirabilis is a common cause of catheter-associated urinary tract infection (C-UTI). It blocks indwelling urethral catheters through the formation of extensive crystalline biofilms. The obstruction of urine flow can induce episodes of pyelonephritis, septicemia, and shock. P. mirabilis exhibits a type of motility referred to as swarming, in which multicellular rafts of elongated, hyperflagellated swarmer cells form and move rapidly in concert over solid surfaces. It has been suggested that swarming is important in the pathogenesis of C-UTI. In this study we generated a set of stable transposon mutants deficient in swarming and used them to assess the role of swarming in the migration of P. mirabilis over urinary catheters. Swarming was found to be essential for migration over all-silicone catheters. Swarming-deficient mutants were attenuated in migration over hydrogel-coated latex catheters, but those capable of swimming motility were able to move over and infect these surfaces. A novel vapor fixation technique for the preparation of specimens and scanning electron microscopy were used to resolve the ultrastructure of P. mirabilis multicellular rafts. The flagellar filaments of P. mirabilis were found to be highly organized during raft migration and were interwoven in phase to form helical connections between adjacent swarmer cells. Mutants lacking these novel organized structures failed to swarm successfully. We suggest that these structures are important for migration and formation of multicellular rafts. In addition, the highly organized structure of multicellular rafts enables P. mirabilis to initiate C-UTI by migration over catheter surfaces from the urethral meatus into the bladder.

DNA Transposable Elements↗
PubMed2003

Why are Foley catheters so vulnerable to encrustation and blockage by crystalline bacterial biofilm?

Many patients undergoing long-term bladder catheterisation experience blockage and encrustation of their catheters. The problem stems from infection by urease producing bacteria, particularly Proteus mirabilis. Bacterial biofilms colonise the catheters, the activity of urease raises the pH and induces the deposition of calcium and magnesium phosphate crystals. In this study, a laboratory model of the catheterised bladder has been used to examine the early stages in the formation of the crystalline biofilms. The results show that initial cell adhesion is to the irregular surfaces surrounding the catheter eye-holes. Microcolonies form in depressions in these surfaces and spread to cover the entire surface of the rims around the eye-holes. Crystals then form around the bacterial populations and the biofilm starts to move down the lumenal surfaces of the catheters. The encrustation develops most extensively and generally blocks the catheter at or just below the eye-hole. There is a need to improve catheter design and manufacturing procedures for the eye-holes if the problems associated with the current devices are to be reduced.

Biofilms↗
PubMed2003

MARSSIM recommended in states' guidance document for decommissioning.

States appreciate guidance for activities done infrequently or at only a few locations in the state. For many states, this is the case for decommissioning. Some states have reactors being decommissioned, some DOE sites undergoing cleanup, and some uranium mill or radium sites. Many, however, only occasionally do a small facility cleanup or, once in a great while, a large one. For this reason, most states participated in the readily available MARSSIM training and now recommend its use. For this same reason, the CRCPD Committee on Decontamination and Decommissioning (E24) developed a brief guidance document for state and licensee use.

Decontamination↗
PubMed2003

Calcium sensing receptor gene A986S polymorphism and responsiveness to calcium supplementation in postmenopausal women.

Recently several studies in adolescent girls or premenopausal women have implicated the calcium sensing receptor (CASR) gene A986S polymorphism in calcium and bone metabolism. However, the role of this genetic variant in postmenopausal women, specifically the development of osteoporosis, is unknown. This study reports the findings of a randomized, double-blind, placebo-controlled study of healthy postmenopausal women followed for 2 yr while taking placebo or supplementary calcium. Specifically, we examined the relationship between the CASR A986S polymorphism, bone biochemical profile, and bone mineral density at baseline and after 2 yr of treatment. We found no effect of this genetic variant in postmenopausal women at baseline or in response to calcium supplementation. These results are in contrast to those in young or premenopausal women, and they provide no support for an important role for the CASR A986S polymorphism in osteoporosis.

Bone Density↗
PubMed2003

Rapamycin has a deleterious effect on MIN-6 cells and rat and human islets.

Rapamycin (sirolimus) is a macrolide fungicide with immunosuppressant properties that is used in human islet transplantation. Little is known about the effects of rapamycin on MIN-6 cells and islets. Rapamycin had a dose-dependent, time-dependent, and glucose-independent deleterious effect on MIN-6 cell viability. At day 1, using the MTT method, 0.01 nmol/l rapamycin reduced cell viability to 83 +/- 6% of control (P < 0.05). Using the calcein AM method, at day 2, 10 nmol/l rapamycin caused a reduction in cell viability to 73 +/- 5% of control (P < 0.001). Furthermore, 10 and 100 nmol/l rapamycin caused apoptosis in MIN-6 cells as assessed by the transferase-mediated dUTP nick-end labeling assay. Compared with control, there was a 3.1 +/- 0.6-fold increase (P < 0.01) in apoptosis in MIN-6 cells treated with 10 nmol/l rapamycin. A supra-therapeutic rapamycin concentration of 100 nmol/l significantly impaired glucose- and carbachol-stimulated insulin secretion in rat islets and had a deleterious effect on the viability of rat and human islets, causing apoptosis of both alpha- and beta-cells.

Animals↗
PubMed2003

Pancreatic-derived factor (FAM3B), a novel islet cytokine, induces apoptosis of insulin-secreting beta-cells.

PANDER (PANcreatic DERived factor, FAM3B), a newly discovered secreted cytokine, is specifically expressed at high levels in the islets of Langerhans of the endocrine pancreas. To evaluate the role of PANDER in beta-cell function, we investigated the effects of PANDER on rat, mouse, and human pancreatic islets; the beta-TC3 cell line; and the alpha-TC cell line. PANDER protein was present in alpha- and beta-cells of pancreatic islets, insulin-secreting beta-TC3 cells, and glucagon-secreting alpha-TC cells. PANDER induced islet cell death in rat and human islets. Culture of beta-TC3 cells with recombinant PANDER had a dose-dependent inhibitory effect on cell viability. This effect was also time-dependent. PANDER caused apoptosis of beta-cells as assessed by electron microscopy, annexin V fluorescent staining, and flow-cytometric terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling assay. PANDER did not affect cytosolic Ca(2+) levels or nitric oxide levels. However, PANDER activated caspase-3. Hence, PANDER may have a role in the process of pancreatic beta-cell apoptosis.

Animals↗
PubMed2003

Understanding differences in influenza immunization rates: a survey of African-American and caucasian medicare beneficiaries in Texas.

A goal of Healthy People 2010 is to increase the influenza immunization rate among high-risk populations to at least 90 percent. This article presents the results of a survey on influenza immunizations among African-Americans and Caucasian Medicare beneficiaries in a 25-county project intervention area in Texas. Information on the burden of suffering from pneumonia and influenza, the benefits of influenza immunization, and recommendations are included. Data are presented on the characteristics of the African-American and Caucasian Medicare beneficiary survey respondents, their influenza immunization rates, health status and sources of health care, and factors that influence them to obtain an annual influenza immunization.

Black or African American↗