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Biomedical subjects

G B Smith

Publications and source records attributed to G B Smith.

At least 73 records · Page 4Linked to original sources
PubMed1994

The polyurethane nasotracheal tube.

An uncuffed nasotracheal tube for use in minor maxillofacial surgery has been developed using polyurethane. The suitability of this tube as an alternative to the existing soft red rubber and harder polyvinyl chloride materials has been assessed at four centres during anaesthesia for routine oral surgery. The tube was found to be satisfactory.

Anesthesia, General↗
PubMed1994

Continuous measurement of systemic vascular resistance.

We have successfully linked a standard patient monitor system (Hewlett Packard M1166A-A66) with the Baxter Edwards Critical-Care Swan Ganz Intellicath continuous cardiac output catheter and the Vigilance continuous cardiac output monitor system to produce continuous values of systemic vascular resistance. Six cases are presented in which marked changes in indexed systemic vascular resistance were observed as a result of clinical interventions. The continuous derivation of systemic vascular resistance has much potential as a diagnostic and research tool as well as allowing rapid accurate assessment of the response of patients to therapy.

Cardiac Output↗
PubMed1994

Dechlorination of trichlorofluoromethane (CFC-11) by sulfate-reducing bacteria from an aquifer contaminated with halogenated aliphatic compounds.

Groundwater samples were obtained from a deep aquifer contaminated with halogenated aliphatic compounds. One-milliliter samples contained 9.2 x 10(5) total bacteria (by acridine orange microscopic counts) and 2.5 x 10(3) sulfate-reducing bacteria (by most probable number analysis). Samples were incubated anaerobically in a basal salts medium with acetate as the electron donor and nitrate and sulfate as the electron acceptors. Residual levels of trichlorofluoromethane (CFC-11) in samples were biotically degraded, while trichloroethylene was not. When successively higher levels of CFC-11 were added, increasingly rapid degradation rates were observed. Concomitant with CFC-11 degradation was the near stoichiometric production of fluorodichloromethane (HCFC-21); the production of HCFC-21 was verified by mass spectrometry. CFC-11 degradation was dependent on the presence of acetate (or butyrate) and sulfate but was independent of nitrate. Other carbon sources such as lactate and isopropanol did not support the degradation. The addition of 1 mM sodium sulfide completely inhibited CFC-11 degradation; however, degradation occurred in the presence of 2 mM 2-bromoethanesulfonic acid. These results indicate that the anaerobic dechlorination of CFC-11 is carried out by sulfate-reducing bacteria and not by denitrifying or methanogenic bacteria.

Acetates↗
PubMed1994

Continuous invasive cardiac output monitoring--the Baxter/Edwards Critical-Care Swan Ganz IntelliCath and Viligance system.

We evaluated the Baxter/Edwards Critical-Care Swan Ganz IntelliCath continuous cardiac output catheter and Vigilance continuous cardiac output monitor in critically ill adult intensive care patients, and compared cardiac output measurements obtained from this new system with those from a standard bolus thermodilution technique using cold normal saline. Nine Swan Ganz IntelliCath catheters were inserted into patients selected at random, following the decision that pulmonary artery catheter monitoring was required. A total of 100 comparisons were made in nine patients. We found the Swan Ganz IntelliCath catheter to be both easy to insert and position, and simple to use. There were no complications or technical difficulties. The mean cardiac output measured by the continuous system was 8.00 l/min (SD 1.66/min) compared to 8.02 1/min (SD 1.74 l/min) using bolus techniques. Continuous cardiac output values correlated well with bolus measurements (r = 0.87), there was excellent accuracy (bias of 0.02 l/min) and precision was acceptable (limits of agreement of -1.71 to 1.75 l/min). These larger than anticipated limits of agreement may not reflect any inaccuracy in the continuous measurement system, rather they may highlight the extent of well recognised potential errors inherent in the intermittent bolus technique. The availability of a system to measure cardiac output continuously provides a major improvement in intensive care monitoring. This system will permit the rapid and accurate assessment of the response of patients to therapy while providing increased diagnostic facilities and a new research tool.

Adult↗
PubMed1993

Phosphorylation of the GABAA receptor by cAMP-dependent protein kinase and by protein kinase C: analysis of the substrate domain.

Previous work has shown that the GABAA-receptor (GABAA-R) could be phosphorylated by cAMP-dependent protein kinase (PKA), protein kinase C (PKC), and a receptor associated kinase. However, no clear picture has yet emerged concerning the particular subunit/subtypes of the GABAA-R that were phosphorylated by PKA and PKC. In the present report we show that an antibody raised against a 23 amino acid polypeptide corresponding to a sequence in the putative intracellular loop of the beta 1 subunit of the receptor blocks the in vitro phosphorylation of the purified receptor by PKA and PKC. Moreover, N-terminal sequence analysis of the principal phosphopeptide fragment obtained after proteolysis of the receptor yielded a sequence that corresponds to the beta 3 subunit of the receptor. Such data provide additional support for our hypothesis (Browning et al., 1990, Proc. Natl. Acad. Sci. USA 87:1315-1317) that both PKA and PKC phosphorylate the beta-subunit of the GABAA-R.

Amino Acid Sequence↗
PubMed1993

Low temperature protocol for efficient transformation of Mycobacterium smegmatis spheroplasts.

Spheroplasts of Mycobacterium smegmatis LM15, strain 607, were prepared by a combined treatment with glycine and lysozyme. The spheroplasts were tested for ability to take up and express purified mycobacteriophage DNA. Exposure of 1.0 x 10(8) to 1.0 x 10(9) spheroplasts to saturating DNA (1 microgram) for 15 min at 5 degrees C resulted in a transfection efficiency of approximately 0.009% . The transfer of the beta-lactamase marker with DNA purified from strain LM15 to spheroplasts of a beta-lactamase-negative mutant, strain LM144, was achieved. The DNA-treated cultures, after reversion to the bacillary form, contained 20-fold more penicillin-resistant cells than the nontreated control culture. Approximately 80% of the penicillin-resistant colonies from the DNA-treated cells were positive for beta-lactamase Cell-free extracts of penicillin-resistant transformants contained beta-lactamase activity that ranged from 0.046 to 0.134 micromol of benzylpenicillin hydrolyzed/min per mg protein. This low temperature procedure is recommended for high efficiency transformation of M. smegmatis.

Mycobacteriophages↗
PubMed1993

The new recovery position, a cautionary tale.

In November 1992 the European Resuscitation Council issued new guidelines which included the description of a modified recovery position. Anecdotal reports have suggested that this 'new' position may result in obstructed venous return in the dependent arm. The findings of a small study to evaluate the 'new' recovery position are reported here. In a group of six healthy adult volunteers measurements of digital temperature, plethysmographic wave form and transcutaneous oxygen saturation were made in the previously favoured semi-prone recovery and repeated in the 'new' position. In the 'new' position 67% of the study group developed signs of venous or venous and arterial obstruction; no such complication was encountered when the same individuals were placed in the semi-prone recovery position. The need to position unconscious persons in some form of recovery position is emphasised, however, the suggestion that the semi-prone position be re-adopted is offered for discussion. Alternatively, adequate monitoring of perfusion and venous drainage in the dependent limb must be undertaken if the 'new' recovery position is chosen.

Arm↗
PubMed1993

Homophobia and attitudes toward gay men and lesbians by psychiatric nurses.

Stereotypic and stigmatic attitudes toward homosexuality may interfere both directly and indirectly with the care provided to gay and lesbian patients. The purpose of this study was to measure attitudes toward gays and lesbians and assess homophobia among psychiatric nurses. The demographic characteristics of education, religious identification, and knowledge of gays and lesbians had positive affects on attitudes and homophobia. The Attitudes Towards Gays and Lesbians Scale (ATGLS) developed by the researcher specifically for this study assessed cognitive attitudes and the Index of Homophobia (IHP), developed by Hudson and Ricketts (1980), measured homophobia, the affective response to gays and lesbians.

Acquired Immunodeficiency Syndrome↗
PubMed1993

The role of psychologists in the treatment, management, and prevention of chronic mental illness.

In addition to suffering from the severe psychiatric symptoms of chronic mental illness (CMI), people with this type of disorder suffer from a variety of secondary disabilities and face societal obstacles that interfere with their ability to maximize their personal, social, and vocational potentials. Following the deinstitutionalization of long-term psychiatric patients in recent decades, many different understandings of the etiology, treatment, and management of CMI have evolved, including those derived from the biological, vulnerability, cognitive, case management, rehabilitation, and psychoeducational models. Because psychologists are trained in a wide range of psychological theories and a broad repertoire of applications, they have unique contributions to make within each model, particularly, as discussed here, to prevent, treat, and manage CMI through research, assessment, and intervention.

Chronic Disease↗