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Biomedical subjects

D Watson

Publications and source records attributed to D Watson.

At least 127 records · Page 7Linked to original sources
PubMed1992

Oxyhaemoglobin saturation following elective abdominal surgery in patients receiving continuous intravenous infusion or intramuscular morphine analgesia.

Oxygen saturation was continuously measured using computerised pulse oximetry for 8 h overnight pre-operatively and for the first 24 h postoperatively in 40 patients receiving intermittent intramuscular morphine or continuous infusion of morphine following elective upper abdominal surgery. The proportion of time with an oxygen saturation less than 94% was used as an index of desaturation. Patients receiving continuous infusion analgesia received a larger morphine dose and achieved better analgesia than the intramuscular group. Postoperatively, the duration of desaturation increased 10-fold over pre-operative values, 'intramuscular' patients spending 39.0% (SD, 37.0%) and 'continuous infusion' patients 40.0% (SD, 37.5%) of the time below 94% saturation. Although newer therapies (e.g. epidural analgesia and patient-controlled analgesia) are currently receiving greater attention, the sequelae of these more traditional analgesic techniques warrant further study.

Abdomen↗
PubMed1992

On traits and temperament: general and specific factors of emotional experience and their relation to the five-factor model.

In this article we investigate relations between general and specific measures of self-rated affect and markers of Neuroticism, Extraversion, Openness to Experience, Agreeableness, and Conscientiousness. Replicating previous research, we found strong and pervasive associations between Neuroticism, its facets, and the various negative affects; and between Extraversion, its facets, and the positive affects. Conscientiousness also had a significant, independent relation with general positive affect, but this effect was entirely due to the specific affect of attentiveness, which was more strongly related to Conscientiousness than Extraversion. Conversely, only the achievement facet of Conscientiousness correlated broadly with the positive affects. Finally, hostility had a strong independent association with (low) Agreeableness. The results for Neuroticism and Extraversion further clarify the temperamental basis of these higher order trait dimensions; whereas those obtained for Agreeableness and Conscientiousness illustrate the importance of examining personality-affect relations at the lower order level.

Adult↗
PubMed1992

Lung function testing in adults with preferential nasal breathing.

Three adult patients with asthma with preferential nasal breathing were found to have a typical pattern of lung function test results with substantial between test variation. This condition can be identified as a cause of unsatisfactory performance in respiratory tests by observing the patient's reaction after the nostrils have been occluded.

Aged↗
PubMed1992

Release of mucus glycoconjugates by Pseudomonas aeruginosa rhamnolipid into feline trachea in vivo and human bronchus in vitro.

Pseudomonas aeruginosa colonizes the lower respiratory tracts of patients with severe bronchiectasis, including cystic fibrosis, a condition associated with increased airway mucus output. We have shown that an extract containing chloroform-soluble extracellular products of P. aeruginosa releases glycoconjugates into the cat trachea in vivo. This activity was not related to pyocyanin, a major component of the extract, but was associated with the rhamnolipids. Purified monorhamnolipid (100 micrograms/ml) released radiolabeled and periodic acid-Schiff (PAS)-reactive glycoconjugates (delta 3H = +490 +/- 70%, delta 35S = +170 +/- 40%, delta PAS = +8.6 +/- 1.7 micrograms/min; n = 6, P less than 0.02 for each). Dirhamnolipid (200 micrograms/ml) was also effective (delta 3H = +640 +/- 70%, delta 35S = +130 +/- 20%, delta PAS = +9.3 +/- 1.5 micrograms/min; n = 6, P less than 0.02 for each). Monorhamnolipid (100 micrograms/ml) also released 35S-labeled and PAS-reactive glycoconjugates from human bronchial tissue in vitro (delta 35S = +189 +/- 47%, delta PAS = +26.3 +/- 8.5 micrograms/min; n = 7, P less than 0.001 versus control tissues in which no stimulus was given). The cat tracheal glycoconjugates released by the rhamnolipids differed from those released by pilocarpine 50 microM, in having a higher 3H:35S ratio (P less than 0.001). After gel chromatography on a Sepharose CL-4B column, the void volume fractions of the glycoconjugates also had different profiles in a cesium chloride density gradient. Those released by rhamnolipid banded at 1.62 g/ml, while those released by pilocarpine banded mainly at 1.50 g/ml, with some of the higher density material also present.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Documentation of paediatric assessments using the occupational therapy guidelines for client-centred practice.

Although documentation is required in occupational therapy, there is little uniformity in content or format between therapists or facilities. The purpose of this article is to present a format that reflects the Canadian Guidelines for the Client-Centred approach to assessment and to share the experience of implementing this format at the Arbutus Society for Children in Victoria, British Columbia. It is hoped that client-centred documentation will facilitate role clarification, service promotion, and quality assurance. As the format reflects the conceptual framework described in the Occupational Therapy Guidelines for Client-Centred Practice (Canadian Association of Occupational Therapists, 1991b), it should be appropriate for use in other areas of practice.

British Columbia↗
PubMed1992

Central conduction time in childhood autism.

To investigate the integrity of the brain-stem in 20 mentally handicapped children who met the Rutter criteria for autism, brain-stem auditory evoked potentials were obtained for a range of stimulus intensities. Central conduction times (CCTs) were calculated for the Wave I-Wave V interval of the brain-stem potentials. In children under 14 years of age CCTs were normal. In children 14 years of age and over, three of four girls and eight of nine boys had CCTs exceeding normal limits when compared with a group of controls of normal intelligence, matched for age and sex. CCTs recorded from a group of non-autistic mentally handicapped children were within normal limits. The age distribution are consistent with a maturational defect in myelination within the brain-stem in autism, a defect which may have a much wider anatomical distribution throughout cortical and subcortical structures.

Adolescent↗
PubMed1992

e-PTFE ventricular shunt catheters.

The perfect polymer surface for implantation should resist the adhesion of bacteria while producing no reaction in surrounding tissues. Silicone elastomer is a common material used for medical implantation devices. This material is superior to most available for implantation because of its flexibility and low, but detectable, tissue reaction. We have evaluated a flexible, expanded polytetrafluoroethylene (e-PTFE) ventricular catheter for cerebrospinal fluid shunting and have found that although e-PTFE is safe for cerebral implantation, the porosity of the material allows tissue ingrowth that obstructs the lumen. Our limited clinical evaluation of 5-microns internodal distance e-PTFE revealed that this open-cell structure, allowing tissue ingrowth, apparently is a poor candidate to replace silicone elastomer in cerebrospinal fluid shunting devices. However, further investigation may provide a polymer superior to silicone elastomer to create a cerebrospinal fluid shunt.

Animals↗
PubMed1991

Specific degenerate codons enhanced selective expression of human parathyroid hormone in Escherichia coli.

Specific degenerate codons in the amino-terminal region of a synthetic human parathyroid hormone (PTH) gene exerted dramatic effects on both products and yield of expression of this 84-amino acid polypeptide in Escherichia coli. With adenine-rich degenerate codons constituting the PTH-(1-5) region, intact PTH has been expressed as the only PTH product at 6.5 mg/liter. In contrast, with guanine-rich degenerate codons, the predominent product was analogue PTH-(8-84). Use of cytosine- or thymine-rich degenerate codons generated only a small amount of immunoreactive product (0.2 mg/l). With the amino terminal region reconstituted with adenine-rich degenerate codons, the mid and carboxyl regions of the synthetic gene were also reconstructed to imitate the E. coli-favored codon degeneracy. Expression yielded the intact PTH at 20 mg/liter. Gel electrophoresis and Western blots, with antibodies specific to the amino or carboxyl terminus of PTH, indicated only a single PTH-related polypeptide, with the same mobility as a synthetic intact PTH sample. Amino acid sequencing, composition analysis, mass spectrometry, and the adenylate cyclase bioassays confirmed the purified product as the processed intact PTH.

Amino Acid Sequence↗
PubMed1991

Analysis of vitamin D and its metabolites using thermospray liquid chromatography/mass spectrometry.

A new method is described for the analysis of vitamin D and its metabolites utilizing thermospray (TSP) mass spectrometry as an on-line detector for high performance liquid chromatography. Ionization conditions were optimized for use with isocratic reversed phase chromatography. TSP mass spectrometry was employed in series with a UV absorbance detector to facilitate comparisons between the two methods of detection. Positive ion TSP mass spectra were recorded for vitamin D2, vitamin D3, 25-hydroxyvitamin D3 (25(OH)D3), 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) and 24,25-dihydroxyvitamin D3 (24,25(OH)2D3). The spectra contained protonated molecular ions, ammonium adduct ions and fragment ions due to the loss of one or more molecules of water. A comparison of quantitative precision was made by determining UV absorbance and TSP standard curves for vitamin D3 using two different methods: (1) External standard method with post-column (post UV detector) addition of ammonium acetate. (2) As (1) but using the method of internal standards with a closely eluting internal standard (vitamin D2). In each case the quantitative precision (correlation coefficient) for UV absorbance detection was superior owing to intrinsic instability of the TSP ion beam. A stable isotopically labelled internal standard was employed in the development of an assay for 1,25(OH)2D3. The assay was used to quantify in vitro enzymic conversion of 25(OH)D3 to 1,25(OH)2D3 in guinea pig and sheep renal mitochondrial incubations. TSP LC/MS was also applied to analysis of an extract of human blood plasma in which D3 and each of its principal metabolites were identified in a single analysis.

24,25-Dihydroxyvitamin D 3↗
PubMed1991

Regional variation in the abundance of axonal cytoskeletal proteins.

The relative abundance of several axonal cytoskeletal proteins was determined by immunoassay at various sites in the peripheral and central nervous systems of adult rats. Within the peripheral nervous system, the ratio of tubulin to neurofilaments was greatest for nerves composed of unmyelinated axons and least for nerves with large myelinated axons. MAP1 protein was more prominent in unmyelinated fibers; conversely tau proteins were relatively more abundant in large myelinated axons. An immunochemical index of neurofilament phosphorylation was less for unmyelinated fibers than for myelinated ones. In the fimbria-fornix, pyramidal tract, and superior cerebellar peduncle, similar trends were observed: small axons had more MAP1, less tau, and a greater ratio of tubulin to neurofilament proteins. The phosphorylation index was greatest for the superior cerebellar peduncle, the tract with the largest axons. The immunochemical index of neurofilament phosphorylation was greater for the optic nerve than for axonal tracts in the brain proper. These results suggest that development of large myelinated axons is associated with greater neurofilament content, neurofilament phosphorylation, and with greater abundance of tau proteins in the CNS and the PNS; however, quantitative aspects of these relationships differ in the PNS and the CNS.

Animals↗
PubMed1991

Tripartite model of anxiety and depression: psychometric evidence and taxonomic implications.

We review psychometric and other evidence relevant to mixed anxiety-depression. Properties of anxiety and depression measures, including the convergent and discriminant validity of self- and clinical ratings, and interrater reliability, are examined in patient and normal samples. Results suggest that anxiety and depression can be reliably and validly assessed; moreover, although these disorders share a substantial component of general affective distress, they can be differentiated on the basis of factors specific to each syndrome. We also review evidence for these specific factors, examining the influence of context and scale content on ratings, factor analytic studies, and the role of low positive affect in depression. With these data, we argue for a tripartite structure consisting of general distress, physiological hyperarousal (specific anxiety), and anhedonia (specific depression), and we propose a diagnosis of mixed anxiety-depression.

Anxiety Disorders↗
PubMed1991

Interaction between Pseudomonas aeruginosa and Staphylococcus aureus: description of an anti-staphylococcal substance.

The presence of Pseudomonas aeruginosa in the sputum of 191 patients with cystic fibrosis was significantly related (p less than 0.0001) to the absence of Staphylococcus aureus. Cross-streaking tests showed that 40 of 50 clinical strains of P. aeruginosa produced substances that inhibited the growth of S. aureus. When incorporated into agar plates, this antibacterial substance(s) inhibited the growth of 177 of 189 strains of nine staphylococcal species, all of 16 methicillin-resistant S. aureus and 27 of 39 strains of six other gram-positive genera. The substance(s) did not inhibit 23 strains of seven gram-negative genera tested. The antibacterial activity was heat stable and could be extracted into chloroform; activity was retained on Sephadex G-15 (V/Vo approximately 2, Mr less than 500) and eluted as a single peak from high performance liquid chromatography, well separated from pseudomonic acid, pyocyanin and a number of other phenazines.

Anti-Bacterial Agents↗
PubMed1991

Preparation, characterization, and immunogenicity of conjugates composed of the O-specific polysaccharide of Shigella dysenteriae type 1 (Shiga's bacillus) bound to tetanus toxoid.

The background for developing conjugate vaccines for shigellosis composed of the O-specific polysaccharide (O-SP) bound to a protein is described elsewhere (C. Y. Chu, R. Schneerson, and J. B. Robbins, submitted for publication). Briefly, there is direct evidence for type (lipopolysaccharide [LPS])-specific protection after infection with the wild type or with attenuated strains of shigellae. Prospective studies of Israeli armed forces recruits show a correlation between preexisting serum immunoglobulin G (IgG) LPS antibodies and resistance to shigellosis (D. Cohen, M. S. Green, C. Block, R. Slephon, and I. Ofek, J. Clin. Microbiol. 29:386-389, 1991). In order to elicit IgG LPS-specific antibodies to Shigella dysenteriae type 1, the O-SP of this pathogen was purified and bound to tetanus toxoid (TT) by three schemes. The most immunogenic used a modification of a published method (C. Y. Chu, R. Schneerson, J. B. Robbins, and S. C. Rastogi, Infect. Immun. 40:245-256, 1983). The resultant O-SP-TT conjugates were stable and elicited high levels of IgG O-SP antibodies and booster responses in young mice when injected subcutaneously in saline at 1/10 the proposed human dose. Adsorption onto alum or concurrent administration with monophosphoryl lipid A enhanced both the IgG and IgM antibody responses to the O-SP of the conjugate; both the nonadsorbed and adsorbed conjugates elicited higher rises of IgG than of IgM antibodies. Clinical evaluations of S. dysenteriae type 1 O-SP-TT conjugates are planned.

Animals↗
PubMed1991

Depression and decision-making among intravenous drug users.

Two short scales, the TCU Depression Scale and the TCU Decision-making Scale, were psychometrically evaluated in a sample of 145 intravenous drug users. Coefficient alpha reliabilities were .78 for the 6-item TCU Depression Scale and .77 for the 9-item TCU Decision-making Scale. Concurrent validity of the former scale was assessed by correlating scores with those on the Beck Depression Inventory, r = .75. Based on the Beck Depression Inventory Clinical cutoff scores, 83% of the sample showed some depression, with 23% severely depressed, 39% moderately depressed, and 21% mildly depressed. Individuals scoring higher on depression on both tests tended to score lower on decision-making. Significant demographic associations of age, gender, education, and race-ethnicity were found for the depression and decision-making scales. More depression was noted for women, those younger, white, and having less education. Older and more educated intravenous drug users tended to score higher on decision-making. Validity for the depression and decision-making scales was assessed by examining correlations with behaviors. Significant positive correlations were found between depression scores and intravenous use of cocaine only, heroin and cocaine combined, and heroin only. Also, intravenous use of cocaine only and of cocaine and heroin combined were negatively related to decision-making. AIDS sex-risky behavior was positively correlated with depression and negatively correlated with decision-making.

AIDS Serodiagnosis↗
PubMed1991

Informal carers of the dementing elderly: a study of relationships.

This study investigated the problems involved in caring for a dementing person in the community from the perspective of their resident informal carer. It also examined the informal carer's relationships with both the dementing person and the statutory and voluntary services. Symbolic interaction theory was applied to this study since it considers the social meanings that things have as a result of an interactional process. To investigate this process, a qualitative research methodology was employed, comprising a diary, interview and post-contact notes. The sample was gathered from multiple referral sources: health, social and voluntary services. The diagnosis of a dementia was confirmed by the individual's own GP. Many of the results from this study support previous work in the field and four recommendations arise from analysis of the data. These are that formal carers could have a greater awareness of the needs of different groups of informal carers, the needs of informal carers in the very early stages of caring for a dementing person, the informal carer's need for counselling and the different reactions to offers of respite and long-term care which are seen as depending upon the relationship between the informal carer and the dementing person.

Adaptation, Psychological↗
PubMed1991

Changes in bile acid composition in patients with primary biliary cirrhosis induced by ursodeoxycholic acid administration.

We describe a detailed study of the effects of ursodeoxycholic acid administration on bile acid composition of the serum and bile of patients with primary biliary cirrhosis. Gas chromatography-mass spectrometry was used to analyze bile acids from 10 patients with primary biliary cirrhosis before and during ursodeoxycholic acid administration (500 mg/day, corresponding to approximately 8 mg/kg body wt), after group separation of the unconjugated and conjugated fractions by lipophilic anion exchange chromatography. These studies were directed at assessing whether the beneficial role of ursodeoxycholic acid in primary biliary cirrhosis was the consequence of a shift in the hydrophobic/hydrophilic balance of the bile acid pool and whether the hypercholeresis might result from the cholehepatic circulation of unconjugated ursodeoxycholic acid in bile. In basal conditions, the unconjugated bile acids accounted for only 5.5% and 2.5%, respectively, of the total bile acids of serum and bile; cholic acid was the major component of the conjugated fraction of serum and bile (56.0% +/- 4.0%, mean +/- S.E.M.), and ursodeoxycholic acid was present in only trace amounts. The conjugated fraction contained many unusual bile acids (representing 16.5% +/- 1.3% of total) including C25 bile acids, iso-chenodeoxycholic acid and several oxo-bile acids. After ursodeoxycholic acid administration biochemical indices of liver function all improved, but the proportions of the unconjugated bile acids in serum and bile did not significantly change.(ABSTRACT TRUNCATED AT 250 WORDS)

Bile↗