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Biomedical subjects

J Clark

Publications and source records attributed to J Clark.

624 records · Page 35Linked to original sources
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An uneasy dilemma.

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Community Health Nursing↗
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Burst width tracking: brief tone thresholds in the normal ear.

This study presents a unique procedure for determining the critical duration and temporal summation function. With this procedure, duration as a parameter was used to determine the temporal summation characteristics of ten normal ears. An apparatus was constructed that permitted subjects to track threshold by modulating the burst width of a brief tonal stimulus. The apparatus permitted experimenter control of the rate of burst width modulation and interburst interval. The burst width could be continuously varied by the subject from 10 to 800 msec. Asymptotic regression indicated that the data were best fit to a simple power function of the form Y = AX(B). A logarithmic transformation was applied to the obtained durations, and slopes of integration were determined for each frequency. These values ranged between 6.3 and 10.2 dB/log unit time. Differences among frequencies were found to be significant. Critical durations were obtained for each subject, and these values were consistent with previous data indicating negligible temporal summation about 150 to 200 msec.

Adult↗
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A survey of public health partner notification for sexually transmitted diseases in Canada.

OBJECTIVE: To describe the range of practice for sexually transmitted disease (STD) contact tracing/partner notification (PN) by public health agencies in Canada. METHODS: A two-level mailed survey, using two different questionnaires, was conducted from Aug. 1991 to Feb. 1992, directed to: 1) provincial and territorial epidemiologists/directors of STD control, asking about program organization; and 2) 154 local health units/provincially run PN programs, asking about practice patterns of STD partner notification. CONCLUSIONS: In Canada, STD PN by public health agencies is routinely practised in most provinces. PN efforts vary by the STD; less PN effort goes to chlamydia despite a high burden of illness; HIV PN is frequently perceived to be within the responsibility of the physician. For STDs with higher PN effort, the preferred method is provider referral. Targeting is seldom utilized, and there are little available data at a local level monitoring even process measures of effectiveness.

Canada↗
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Partner notification for sexually transmitted diseases: proposed practice guidelines.

Using the results of an analysis of available scientific evidence and a survey of current practice in Canada, as well as expert opinion, these guidelines attempt to consider current partner notification practice in Canada and recommend an approach to determining practice which is flexible enough to address local circumstances. Priority areas for future research were also identified.

Advisory Committees↗
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Effectiveness of pH measurements in predicting feeding tube placement: an update.

This paper reports further findings from an ongoing clinical study designed to evaluate the extent to which pH values of aspirates from feeding tubes can be used to differentiate between gastric and intestinal tube placement and gastric and respiratory tube placement. The sample consisted of 405 aspirates from small-bore nasogastric tubes and 389 aspirates from nasointestinal tubes, which were obtained from 605 subjects ranging in age from 18 to 94 years. Data were collected at the time of initial placement and again, when possible, after feedings were initiated. A total of 794 pH-meter readings were made concurrently with X-rays to determine feeding tube position. Gastric placement was successfully distinguished from intestinal placement of the feeding tubes on the basis of pH-meter readings (p < .0001). Approximately 85% of the 405 pH-meter readings from gastric fluid were between 0 and 6.0, while over 87% of the 389 pH-meter measurements performed on intestinal aspirates were greater than 6.0. Four aspirates from feeding tubes inadvertently placed in the respiratory tract (two in the pleural space and two in the tracheobronchial tree) were tested with a pH-meter, all had pH values greater than 6.5.

Adolescent↗
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Toward an International Classification for Nursing Practice: a literature review & survey.

In 1991 the International Council of Nurses (ICN) initiated a long-term project to develop an International Classification for Nursing Practice (ICNP). To identify existing classifications and nomenclatures of nursing, a literature search and survey of national nurses' associations and individuals involved in classification across the world were conducted, in addition to a pilot search for articles describing nursing nomenclatures and classifications in countries other than the US and Canada, the latter having provided most of the examples in the original ICNP proposals. Three sources of literature were examined: international conference proceedings, Med-Line and Exerpta Medica.

Cultural Characteristics↗
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Identification and characterization of the sulfate precipitate in GI147211C IV formulation.

GI147211, a water soluble analog of camptothecin, is currently being investigated for the treatment of cancer as a topoisomerase I inhibitor. Precipitate was observed in some samples of a stability lot of the IV clinical formulation after being stored at 5 degrees C for one month. The precipitate was identified as the sulfate salt of GI147211 by various techniques including Environmental Scanning Electron Microscope/Energy Dispersive X-ray (ESEM/EDX) and Ion Chromatography (IC). The cause of the precipitation was proven to be from the presence of residual sulfate ions in ammonium sulfate treated glass vials that were suspected to be improperly washed. The solubility product (Ksp) of the sulfate salt was determined in 5% dextrose solution adjusted to pH 3.5 at 5 degrees C to mimic the clinical formulation and refrigerated storage conditions. The Ksp was also determined at 15 and 33 degrees C to determine the temperature effect on the constant. The stoichiometry of the sulfate salt was determined by solubility experiments using HPLC and IC to be 2:1 (base/salt). Based on the stoichiometry, the Ksp was calculated to be 3.04 x 10(-12), 9.27 x 10(-12) and 9.96 x 10(-11) M3 at 5 degrees C, 15 degrees C and 33 degrees C, respectively. Using the Ksp values, the sulfate threshold in GI147211 Injection when GI147211 sulfate precipitates was determined to be 1.3, 3.8 and 41 ppm at 5, 15 and 33 degrees C, respectively. Further experiments demonstrated that using the proper cleaning techniques the sulfate level in the treated vials was reduced to < 1.3 ppm. The washing cycles for the vials used for clinical supplies were thereafter modified so that the sulfate precipitate would no longer be an issue.

Antineoplastic Agents↗
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The International Classification for Nursing Practice (ICNP): nursing outcomes.

A classification of nursing phenomena (as diagnosed by nurses) and of nursing interventions is included in the Alpha Version of the International Classification for Nursing Practice (ICNP). The third dimension of the ICNP-nursing outcomes-is currently being developed. Below are some of the issues, initial thinking and possible directions for the classification of nursing outcomes. As in the case of the Alpha Version's classifications of nursing phenomena and nursing interventions, the active participation of nurses around the world is being sought for the development of an improved Beta Version.

Humans↗