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Biomedical subjects

T Webster

Publications and source records attributed to T Webster.

At least 19 recordsLinked to original sources
PubMed1999

Comprehensive computerized diabetes registry. Serving the Cree of Eeyou Istchee (eastern James Bay).

PROBLEM BEING ADDRESSED: Diabetes is rapidly evolving as a major health concern in the Cree population of eastern James Bay (Eeyou Istchee). The Cree Board of Health and Social Services of James Bay (CBHSSJB) diabetes registry was the initial phase in the development of a comprehensive program for diabetes in this region. OBJECTIVE OF PROGRAM: The CBHSSJB diabetes registry was developed to provide a framework to track the prevalence of diabetes and the progression of diabetic complications. The database will also identify patients not receiving appropriate clinical and laboratory screening for diabetic complications, and will provide standardized clinical flow sheets for routine patient management. MAIN COMPONENTS OF PROGRAM: The CBHSSJB diabetes registry uses a system of paper registration forms and clinical flow sheets kept in the nine community clinics. Information from these sheets is entered into a computer database annually. The flow sheets serve as a guideline for appropriate management of patients with diabetes, and provide a one-page summary of relevant clinical and laboratory information. CONCLUSIONS: A diabetes registry is vital to follow the progression of diabetes and diabetic complications in the region served by the CBHSSJB. The registry system incorporates both a means for regional epidemiologic monitoring of diabetes mellitus and clinical tools for managing patients with the disease.

Adolescent↗
PubMed1997

The use of the flow-volume loop in assessing the results of laryngotracheal reconstruction.

The difficult problem of assessing pre- and postoperative airway function in patients with laryngotracheal upper airway obstruction is discussed. A series of 26 patients with various forms of this problem is presented. The method of performing the flow-volume loop (FVL) is described and the theory behind the investigation is reviewed. Five of the series of 26 patients are described in detail as examples, and the advantages and disadvantages of this investigation are discussed fully. The FVL appears to be the only really objective test to assist the laryngotracheal reconstructive surgeon. It is easily performed in most cases and should form part of the diagnostic and postoperative workup.

Adolescent↗
PubMed1996

Associations between changes in selected facial dimensions and the outcome of orthodontic treatment.

The purpose of this study was to determine, in children with Class II, Division I malocclusion who were treated with functional appliances, the strength of the associations between the changes over 18 months in selected facial dimensions and the success of orthodontic treatment as determined by the weighted Peer Assessment Rating (PAR). Forty-two children, between 10 and 13 years of age (mean age 11.6 years), were randomly assigned to either an untreated group (control) or a group treated with either a Fränkel function regulator or Harvold activator (treatment). The outcome of treatment was assessed on study models and the craniofacial changes were measured on lateral cephalometric radiographs. Correlation coefficients were then calculated between the differences in the cephalometric variables over 18 months and the differences in the PAR scores. In the treatment group, the effects of normal growth were held constant by partial correlation. The partial used was the change in both stature and weight. Significant positive partial correlations were found between the increases in total anterior face height, posterior face height, S-Pg, and treatment success. Significant negative partial correlations were found between downward movement of the maxilla and mandibular body and lower anterior face height and treatment success. It is postulated that these associations occurred mainly in response to the bite opening by the appliances. Treatment success was also significantly associated with maxillary restriction, an increase in the SNB angle and a reduction in the ANB angle. Changes in B point due to proclination of the mandibular incisors were considered to be responsible for the two latter significant associations. Although mandibular length increased significantly in the treatment group, as compared with the control group, it was not significantly associated with treatment success.

Activator Appliances↗
PubMed1996

Comparison of three methods for recovery of yeasts from hands of health-care workers.

This study compared three methods for the detection of yeasts on the hands of 30 nurses: (i) direct finger impressions on inhibitory mold agar plates, (ii) bag washes in brain heart infusion broth, and (iii) bag washes in brain heart infusion broth supplemented with gentamicin and vancomycin. The antimicrobial agent-supplemented bag wash method identified the greatest number of yeast carriers and yielded the most yeast isolates, especially non-C. albicans Candida spp.

Candida↗
PubMed1993

Chromosomal rearrangement segregating with adrenoleukodystrophy: a molecular analysis.

The relationship between X chromosome-linked adrenoleukodystrophy and the red/green color pigment gene cluster on Xq28 was investigated in a large kindred. The DNA in a hemizygous male showed altered restriction fragment sizes compatible with at least a deletion extending from the 5' end of the color pigment genes. Segregation analysis using a DNA probe within the color pigment gene cluster showed significant linkage with adrenoleukodystrophy (logarithm of odds score of 3.19 at theta = 0.0). These data demonstrate linkage, rather than association, between a unique molecular rearrangement in the color pigment gene cluster and adrenoleukodystrophy. The DNA changes in this region are thus likely to be helpful for determining the location and identity of the responsible gene.

Adrenoleukodystrophy↗
PubMed1993

Exercise, regardless of induced bronchoconstriction or inspired air conditions, does not alter airway reactivity.

The effects of exercise on asthmatic airway caliber are well recognized. Only a few studies, however, evaluated the effects of prior exercise on asthmatic airway reactivity. Eight asthmatic children (ages 10 to 16 years; mean, 12) performed histamine inhalation tests on three occasions assigned in random order: (1) control; (2) 40 to 60 min after exercise (6 min ergometer cycling) done while breathing cold dry (CD) air (temperature = -13 degrees C, relative humidity = 0 percent); and (3) 40 to 60 min after exercise done while breathing warm humid (WH) air (temperature = 33 degrees C, relative humidity = 100 percent). While there was a marked exercise-induced bronchoconstriction (EIB) in the CD test with a postexercise fall in FEV1 of 39.2 +/- 8 percent (mean +/- SEM), there was no EIB in the WH test (4.6 +/- 2 percent). There was no difference, however, in the geometric mean histamine concentration required to produce a 20 percent fall in FEV1 (PC20) among the CD, WH, and control tests (0.52 mg/ml, 0.60 mg/ml, and 0.55 mg/ml, respectively). Airway reactivity in asthmatic children is not influenced by a prior exercise challenge, independent of the conditions of the inspired air during the exercise. Moreover, exercise per se, regardless of development of EIB, does not change the reactivity.

Adolescent↗
PubMed1988

Sequence of the lon gene in Escherichia coli. A heat-shock gene which encodes the ATP-dependent protease La.

To learn more about the mechanism and regulation of the ATP-dependent protease La in Escherichia coli, the lon gene was completely sequenced using the dideoxy method on fragments generated by Bal31 digestion. The predicted amino acid composition based on the DNA sequence agreed well with the composition of the acid-hydrolyzed protease. The predicted NH2-terminal amino acid sequence, tryptophan content, and the carboxyl terminus also agreed with experimental data. However, the molecular weight of 87,000 (783 amino acids) calculated from the DNA sequence was lower than prior estimates. The tetrameric enzyme contains four binding sites for ATP, a DNA-binding domain, a proteolytic site, and a regulatory site that binds unfolded polypeptides. An ATP-binding pocket exists on each subunit as shown by consensus sequences and elements of secondary structure resembling those on other nucleotide-binding proteins (e.g. adenylate kinase, RecA). For this purpose, improved consensus patterns for identifying ATP-binding domains were developed. Computer-assisted comparisons, however, failed to demonstrate any regions homologous to sequences in other polypeptides including proteases or DNA-binding proteins. This enzyme also contains an unusual highly acidic domain surrounded by very basic sequences. Protease La is the first ATP-dependent protease sequenced and seems to represent a new type of enzyme. The promoter sequence was similar to consensus sequences for other heat-shock promoters. Using site-directed mutagenesis, alterations were introduced into the putative promoter sequence. Mutations upstream of -35 had little effect, but alterations immediately upstream of -10 lowered basal transcription of a lon-lacZ operon fusion and reduced its response to inducers of the heat-shock response.

ATP-Dependent Proteases↗
PubMed1988

Prediction of similar transforming regions in simian virus 40 large T, adenovirus E1A, and myc oncoproteins.

Regions containing similar elements of primary and predicted secondary structure were identified in simian virus 40 large T, adenovirus E1A, c-myc and v-myc proteins by a computer program with a set of highly specific, complex pattern descriptors. In all cases these regions were localized in domains of the respective proteins known to be required for transforming activity. We suggest that these apparently structurally similar regions may mediate a common biological function.

Adenovirus Early Proteins↗
PubMed1987

A modified Chou and Fasman protein structure algorithm.

A FORTRAN program PRSTRC has been developed for protein secondary structure prediction, which is a modified Chou and Fasman (1978) analysis. This implementation carries out a running average of amino acid structure occurrence frequencies, utilizes a simple set of nucleation conditions, and allows user control over nucleation threshold and cutoff parameters. The algorithm includes prediction of the newly defined secondary structure elements: omega loops (1986). It also generates a charge distribution and hydropathy profile. Output includes a simple graphic display for a printer, or a CRT using color addition. Correct structures are predicted for T. dyscritum hemerythrin and the variable domain of mouse immunoglobin k-chain.

Algorithms↗
PubMed1985

Reflex heart rate control in asthma. Evidence of parasympathetic overactivity.

The bronchial hyperreactivity characteristic of asthma may be related to enhanced parasympathetic nervous activity. We postulated that an abnormality in the autonomic control of airway caliber might be reflected by a parallel change in the reflex control of heart rate. We examined the heart-rate variations induced by deep breathing (respiratory sinus arrhythmia), the Valsalva maneuver, and standing up from the recumbent position in asthmatic subjects and nonasthmatic control subjects. The asthmatic patients had evidence of enhanced parasympathetic neural drive to the sinoatrial node, as manifested by a significantly greater magnitude of respiratory sinus arrhythmia, than the controls (p less than 0.0005). We were unable to induce a similar change in normal subjects by resistance breathing. A statistical analysis suggested the presence of a relationship between the magnitude of respiratory sinus arrhythmia and the degree of bronchial hyperreactivity in a group of asthmatic patients. Our results support the hypothesis that enhanced parasympathetic activity is an important factor in the pathogenesis of bronchial asthma.

Adult↗
PubMed1984

Specific sequence homology and three-dimensional structure of an aminoacyl transfer RNA synthetase.

Few and limited amino acid sequence homologies have been found among eight bacterial aminoacyl transfer RNA (tRNA) synthetases whose primary structures are known. The entire 939-amino acid primary structure of Escherichia coli isoleucyl-tRNA synthetase is now reported. In a sequence of 11 consecutive amino acids matching a sequence in E. coli methionyl-tRNA synthetase, there are ten identical residues and one conservative change. This is the strongest homology recorded between any two aminoacyl tRNA synthetases. This part of the methionine enzyme's three-dimensional structure has been determined, and it occurs in a mononucleotide binding fold; a close three-dimensional structural homology of this part of the enzyme with Bacillus stearothermophilus tyrosyl-tRNA synthetase has also been reported. The three synthetases probably fold identically in this region.

Amino Acid Sequence↗
PubMed1981

The Parkmedic Program: prehospital care in the national parks.

The Parkmedic Program provides training and on-going supervision of national park rangers involved in advanced prehospital medical care in Yosemite, Kings Canyon, and Sequoia National Parks in California. This includes intravenous catheterization and drug administration in emergency situations. Course structure, experience to date, and recommendations for future programs are presented.

Adult↗
PubMedDate not supplied

Dioxin emission inventories and trends: the importance of large point sources.

We estimated atmospheric emissions of TEQ for US municipal solid waste incinerators for which PCDD/PCDF measurements are available (81 of about 160 facilities). We compared our annual totals for 1985-1995 with estimates computed using the emission factor approach. Our estimates for a fraction of the facilities was larger than many estimates for all incinerators combined. Our inventory was dominated by several large sources; two facilities emitted on the order of a kilogram of TEQ annually. Retrofit or closing of several incinerators indicates a substantial decrease in atmospheric emissions. Communities addressing the remaining sources will face a choice between expensive retrofits and adoption of alternative methods of handling waste.

Air Pollution↗