PubMed Health⌕ Search

Biomedical subjects

D Patterson

Publications and source records attributed to D Patterson.

At least 19 recordsLinked to original sources
PubMed2005

High-flux beam source for cold, slow atoms or molecules.

We demonstrate and characterize a high-flux beam source for cold, slow atoms or molecules. The desired species is vaporized using laser ablation, then cooled by thermalization in a cryogenic cell of buffer gas. The beam is formed by particles exiting a hole in the buffer gas cell. We characterize the properties of the beam (flux, forward velocity, temperature) for both an atom (Na) and a molecule (PbO) under varying buffer gas density, and discuss conditions for optimizing these beam parameters. Our source compares favorably to existing techniques of beam formation, for a variety of applications.

Journal Article↗
PubMed2003

Protein levels of genes encoded on chromosome 21 in fetal Down syndrome brain: challenging the gene dosage effect hypothesis (Part II).

Down syndrome (DS) is the most common genetic cause of mental retardation. To explain the impact of extra chromosome 21 in the pathology of DS, gene dosage effect hypothesis has been proposed, but several investigators including our group have challenged this hypothesis. Although analysis of the sequence of chromosome 21 has been essentially completed, the molecular and biochemical mechanisms underlying the pathology are still unknown. We therefore investigated expression levels of six proteins encoded on chromosome 21 (HACS1, DYRK1A, alphaA-crystallin, FTCD, GARS-AIRS-GART, and CBS) in fetal cerebral cortex from DS and controls at 18-19 weeks of gestational age using Western blot analysis. Protein expression of HACS1 was significantly and remarkably decreased in DS, and the expression levels of five proteins were comparable between DS and controls suggesting that the gene dosage effect hypothesis is not sufficient to fully explain the DS phenotype. We are continuing to quantify proteins whose genes are encoded on chromosome 21 in order to provide a better understanding of the pathobiochemistry of DS at the protein level.

Blotting, Western↗
PubMed2003

The effects of KT3-671, a new angiotensin II (AT 1) receptor blocker in mild to moderate hypertension.

AIMS: To compare the antihypertensive effect, and tolerability and safety of once daily doses of KT3-671 with that of placebo in patients with mild to moderate uncomplicated essential hypertension. METHODS: A randomised, multicentre, double blind, parallel-group comparison of KT3-671 with placebo. Hypertensive patients [Ambulatory Blood Pressure Monitoring (ABPM), mean daytime DBP > 90 mmHg, Office sitting mean DBP 95-114 after a 7-28 day washout period] entered a 2-week, single blind, run-in phase. Patients eligible for the double-blind phase were randomised to receive KT3-671 40 mg, 80 mg, 160 mg or placebo once daily over 4 weeks. The primary end-point was trough mean sitting office DBP. The study had 90% power to detect a 5 mmHg change between treatments and placebo at the 5% level of significance. The secondary end-points were 24 hour, daytime and night time mean ABPM. RESULTS: Office DBP was significantly lower with KT3-671 40 mg but not the other 2 dosage groups (-3.2; 95% CL -6.1 : -0.3 P < 0.03). Office SBP was significantly reduced with all dosage groups (40 mg -5.9, 95% CL -11 : -0.9; 80 mg -4.9, 95% CL -9.9 : 0.1 and 160 mg -5.7, 95% CL -10.8 : -0.7 P < 0.05). All doses of KT3-671 reduced systolic and diastolic ABPM. The number of patients with treatment related adverse events were comparable to placebo (38.8% KT3-671 vs 32.8% placebo). There was some evidence of a dose-response relationship with fall in nocturnal ABPM. CONCLUSIONS: Oral KT3-671 was well tolerated. KT3-671 reduced office systolic BP at all doses and diastolic BP at some of the doses. Due to greater precision and power, the falls in mean ambulatory systolic and diastolic pressure were all significantly lower than placebo.

Adult↗
PubMed2003

Nail gun injuries in residential carpentry: lessons from active injury surveillance.

OBJECTIVE: To describe circumstances surrounding injuries involving nail guns among carpenters, calculate injury rates, identify high risk groups and preventive measures. METHODS: and setting: Active injury surveillance was used to identify causes of injury among a large cohort of union residential and drywall carpenters. Injured carpenters were interviewed by experienced journeymen; enumeration of workers and hourworked were provided by the union. The combined data allowed definition of a cohort of carpenters, their hours worked, detailed information on the circumstances surrounding injuries, and identification of preventive measures from the perspectives of the injured worker and an experienced investigator. RESULTS: Nail guns were involved in 14% of injuries investigated. Ninety percent of these injuries were the result of the carpenter being struck, most commonly by a nail puncturing a hand or fingers. The injury rate among apprentices was 3.7 per 200 000 hours worked (95% confidence interval (CI) 2.7 to 4.9) compared with a rate of 1.2 among journeymen (95% CI 0.80 to 1.7). While not always the sole contributing factor, a sequential trigger would have likely prevented 65% of the injuries from tools with contact trip triggers. CONCLUSIONS: Training, engineering, and policy changes in the workplace and manufacturing arena are all appropriate targets for prevention of these injuries. Use of sequential triggers would likely decrease acute injury rates markedly. Over 70% of injuries among residential carpenters were associated with through nailing tasks (such as nailing studs or blocks, trusses or joists) or toe nailing (angled, corner nailing) as opposed to flat nailing used for sheathing activities; this provides some indication that contact trip tools could be used solely for flat nailing.

Accidents, Occupational↗
PubMed2002

Information architecture for a federated health record server.

This paper describes the information models that have been used to implement a federated health record server and to deploy it in a live clinical setting. The authors, working at the Centre for Health Informatics and Multiprofessional Education (University College London), have built up over a decade of experience within Europe on the requirements and information models that are needed to underpin comprehensive multi-professional electronic health records. This work has involved collaboration with a wide range of health care and informatics organisations and partners in the healthcare computing industry across Europe though the EU Health Telematics projects GEHR, Synapses, EHCR-SupA, SynEx and Medicate. The resulting architecture models have fed into recent European standardisation work in this area, such as CEN TC/251 ENV 13606. UCL has implemented a federated health record server based on these models which is now running in the Department of Cardiovascular Medicine at the Whittington Hospital in North London. The information models described in this paper reflect a refinement based on this implementation experience.

Computer Communication Networks↗
PubMed2001

Carbonates, thiocarbonates, and the corresponding monoalkyl derivatives. 1. Their preparation and isotropic (13)C NMR chemical shifts.

Three series of potassium carbonate and thiocarbonate salts were synthesized, and the corresponding (13)C isotropic solid-state NMR and the aqueous solution (13)C and (1)H NMR data were collected. The series of compounds that were studied consists of (1) the parent compounds, i.e., potassium carbonate, K(2)CO(3), potassium hydrogen carbonate, KHCO(3), potassium monothiocarbonate, K(2)CO(2)S, potassium dithiocarbonate, K(2)COS(2), and potassium trithiocarbonate, K(2)CS(3), (2) the oxygen monoalkyl substituted derivatives of the parent compounds (OR series), i.e., three potassium O-alkylcarbonates, KO(2)COR, three potassium O-alkylmonothiocarbonates, KOSCOR, and three potassium O-alkyldithiocarbonates, KS(2)COR, all with R = CH(3), CH(2)CH(3), CH(CH(3))(2), and (3) the sulfur monoalkyl substituted derivatives of the parent compounds (SR series), i.e., two potassium S-alkylmonothiocarbonates, KO(2)CSR; two potassium S-alkyldithiocarbonates, KOSCSR, and two potassium S-alkyltrithiocarbonates, KS(2)CSR, all with R = CH(3) or CH(2)CH(3). The preparation and proper characterization of KO(2)CSR and KOSCSR with R = CH(3) and CH(2)CH(3) along with new IR and X-ray powder diffraction data for several other compounds in the series are reported for the first time in this study. Solution NMR data for KO(2)CSR (R = CH(3), CH(2)CH(3)) and KOSCSR (R = CH(3)) and solid-state NMR data for K(2)CO(2)S and K(2)COS(2) could not be obtained because they are unstable under the corresponding measurement conditions. The isotropic chemical shift values of the central carbon atoms obtained from solid-state MAS (magic angle spinning) NMR experiments deviate at most by 3 ppm from the corresponding solution values. Two major trends in the (13)C chemical shift values of the central carbon atoms were found. First, if an oxygen atom in a parent compound or in an alkyl-substituted derivative is replaced by a sulfur atom, a significantly higher chemical shift value is observed. This trend is discussed in terms of the paramagnetic contribution to the chemical shielding constant. Second, the size of the alkyl group in the monoalkyl derivatives has a very small effect on the chemical shift values of the central carbon atoms. This observation is explained using the concept of varying inductive effects produced by alkyl groups. The trends observed for the (13)C and (1)H chemical shift values of the alkyl groups follow common concepts on the structure dependency of chemical shifts.

Journal Article↗
PubMed2001

Heroin use in adolescents and young adults admitted for drug detoxification.

PURPOSE: To examine heroin use and associated morbidity in young adults undergoing drug detoxification. METHODS: A retrospective chart review of all persons (ages 18-25) admitted to either of the two state-funded detoxification facilities in Rhode Island was conducted between June 1998 and June 1999. Only those reporting heroin as a primary drug were included in this study (N=201). RESULTS: Clients were largely male (64%), and white (79%), with a mean age of 22. Of those that reported heroin as their primary drug, 62% used primarily by injection. Mean age of initiation for heroin use was 18.3 years. Twenty-two percent reported a psychiatric diagnosis, and 80% reported a substance-abusing family member. Injection, previous overdose, and a mother with a history of substance use were associated with early initiation of heroin use. CONCLUSIONS: The majority of young adults with heroin addiction undergoing detoxification began using heroin during late adolescence. Concurrence of psychiatric and medical diagnoses with heroin addiction was common, and may contribute to the severity of drug use. Efforts to identify risk factors for heroin and other injection drug use in adolescents and young adults will be critical for the design of effective interventions to prevent injection drug use and its associated morbidities.

Adolescent↗
PubMed2001

Detection of immunomagnetically captured Escherichia coli O157:H7 by antibody-conjugated alkaline phosphatase.

A rapid and sensitive detection process for Escherichia coli O157:H7 was developed using alkaline phosphatase (APase)-labeled anti-E. coli O157 antibodies to tag the targeted bacteria. Immunomagnetic beads or antibody-labeled streptavidin-coated magnetic beads were then used to capture the APase-tagged E. coli. Immunomagnetically captured bacteria were washed and distributed into microplates or optical cuvettes. The enzyme-catalyzed hydrolysis of p-nitro-phenol phosphate in alkaline solutions was then followed. Less than 1000 cfu/ml of E. coli O157:H7 could be detected. This approach was applied to detect the bacteria artificially spiked in beef hamburgers. Less than 1 cfu/g of E. coli O157:H7 produced a significant response after cultural enrichment for 4-6 h at 37 degrees C.

Alkaline Phosphatase↗
PubMed2001

Serum hormone levels in humans with low serum concentrations of 2,3,7,8-TCDD.

We measured current serum hormone and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) concentrations in 37 men who sprayed 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) in the State of Victoria, Australia. TCDD levels were consistently significantly inversely related to prolactin levels in all analyses. In correlation analyses, TCDD levels were also inversely related to triiodothyronine (T3), thyroid-stimulating hormone (TSH), and testosterone levels, and positively associated with glucagon levels. The mean serum TCDD concentration in these sprayers was between 2.6 and 8.1 parts per trillion (ppt). Since such TCDD levels are commonly found in the general population in countries such as the US, the results could suggest that background levels of TCDD in the general population could have an effect on hormone levels. The findings are preliminary and need to be replicated in order to evaluate their full public health significance.

Adult↗
PubMed2001

The HIV/AIDS pandemic and its gender implications.

From 13-18 November 2000, the United Nations Division for the Advancement of Women, the World Health Organization, and UNAIDS convened an international meeting of experts in Windhoek, Namibia, to discuss the linkages between HIV/AIDS, gender, human rights, and human security.

Congresses as Topic↗
PubMed2000

Genetic mapping of a mouse modifier gene that can prevent ALS onset.

Mutations in the cytoplasmic Cu/Zn superoxide dismutase (SOD1) gene on human chromosome 21q22.1 cause 10-20% of familial amyotrophic lateral sclerosis (ALS) cases. The expression of the ALS phenotype in mice carrying the murine G86R SOD1 mutation is highly dependent upon the mouse genetic background. This is similar to the phenotypic variation observed in ALS patients containing identical SOD1 mutations. In the FVB/N background, mice expressing mG86R SOD1 develop an ALS phenotype at approximately 100 days. However, when these mice were bred into a mixed background of C57Bl6/129Sv, the onset of the ALS phenotype was delayed (143 days to >2 years). Using 129 polymorphic autosomal markers in a whole genome scan, we have identified a major genetic modifier locus with a maximum lod score of 5.07 on mouse chromosome 13 between D13mit36 and D13mit76. This 5- to 8-cM interval contains the spinal muscular atrophy (SMA)-associated gene Smn (survival motor neuron) and seven copies of Naip (neuronal apoptosis inhibitory protein), suggesting a potential link between SMA and ALS.

Amyotrophic Lateral Sclerosis↗
PubMed2000

The DNA sequence of human chromosome 21.

Chromosome 21 is the smallest human autosome. An extra copy of chromosome 21 causes Down syndrome, the most frequent genetic cause of significant mental retardation, which affects up to 1 in 700 live births. Several anonymous loci for monogenic disorders and predispositions for common complex disorders have also been mapped to this chromosome, and loss of heterozygosity has been observed in regions associated with solid tumours. Here we report the sequence and gene catalogue of the long arm of chromosome 21. We have sequenced 33,546,361 base pairs (bp) of DNA with very high accuracy, the largest contig being 25,491,867 bp. Only three small clone gaps and seven sequencing gaps remain, comprising about 100 kilobases. Thus, we achieved 99.7% coverage of 21q. We also sequenced 281,116 bp from the short arm. The structural features identified include duplications that are probably involved in chromosomal abnormalities and repeat structures in the telomeric and pericentromeric regions. Analysis of the chromosome revealed 127 known genes, 98 predicted genes and 59 pseudogenes.

Base Sequence↗
PubMed2000

Hypnosis as an empirically supported clinical intervention: the state of the evidence and a look to the future.

Drawing on the literature reviews of this special issue of the International Journal of Clinical and Experimental Hypnosis (2000), this article summarizes the evidence for the effectiveness of hypnosis as an empirically supported clinical intervention. As a whole, the clinical research to date generally substantiates the claim that hypnotic procedures can ameliorate some psychological and medical conditions, as judged against the Chambless and Hollon methodological guidelines. In many cases, these clinical procedures can also be quite cost-effective. It is probable that with some key empirical refinement a number of other hypnosis treatment protocols will have sufficient empirical documentation to be considered "well-established." However, it is noted that the Chambless and Hollon guidelines are not particularly well-suited for assessing hypnosis' impact when used adjunctly with other interventions. The article concludes with recommendations regarding the efficacy questions that need to be more fully addressed empirically and offers methodological guidelines for researchers and practitioners.

Anxiety↗