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Biomedical subjects

K M White

Publications and source records attributed to K M White.

At least 19 recordsLinked to original sources
PubMed1999

The theory of planned behaviour: self-identity, social identity and group norms.

The aim of the present study was to examine further the role that self-identity plays in the theory of planned behaviour and, more specifically, to: (1) examine the combined effects of self-identity and social identity constructs on intention and behaviour, and (2) examine the effects of self-identity as a function of past experience of performing the behaviour. The study was concerned with the prediction of intention to engage in household recycling and reported recycling behaviour. A sample of 143 community residents participated in the study. It was prospective in design: measures of the predictors and intention were obtained at the first wave of data collection, whereas behaviour was assessed two weeks later. Self-identity significantly predicted behavioural intention, a relationship that was not dependent on the extent to which the behaviour had been performed in the past. As expected, there was also evidence that the perceived norm of a behaviourally relevant reference group was related to behavioural intention, but only for participants who identified strongly with the group, whereas the relationship between perceived behavioural control (a personal factor) and intention was strongest for low identifiers.

Adolescent↗
PubMed1996

Pharmacokinetics in nonhuman primates of a prototype carbapenem active against methicillin-resistant Staphylococcus aureus.

Pharmacokinetic parameters were determined for imipenem-cilastatin and a carbapenem antibiotic, L-695,256, active against methicillin-resistant Staphylococcus aureus in rhesus monkeys and a chimpanzee. L-695,256 had larger areas under the concentration-time curve than imipenem-cilastatin (30 +/- 5 versus 24 +/- 1 micrograms.h/ml in the rhesus monkeys and 77 versus 60 micrograms.h/ml in the chimpanzee) and a longer half-life at beta phase (1.2 +/- 0.1 versus 0.6 +/- 0.1 h in the rhesus monkeys and 1.0 versus 0.8 h in the chimpanzee). Resistance to hydrolysis by the renal dehydropeptidase-I allowed L-695,256 to be administered as a single agent.

Animals↗
PubMed1994

Vibrometry testing for carpal tunnel syndrome: a longitudinal study of daily variations.

The method of limits procedure was used to obtain 84 120Hz vibration thresholds, over a 3-month period, on four age-matched women with different levels of carpal tunnel syndrome (CTS). Each woman used a keyboard for 4 hours a day during work. Testing was conducted in a room with a temperature of 28 degrees C +/- 2 degrees C after 20 minutes acclimation. Results indicate vibration thresholds vary significantly from day to day and also demonstrate how a single vibrometry measure may falsely identify the participant's true CTS condition. Specifically, a single measure could account for a negative CTS determinations in affected wrists or positive CTS determinations in healthy wrists. Subsequent analysis revealed menses related fluid retention and day of the week increase the vibration thresholds. Analyzing the levels of fluid retention by day of the week indicates a compounding effect of the personal and occupational risk factors.

Body Fluids↗
PubMed1993

Human basic tear fluid osmolality. I. Importance of sample collection strategy.

Osmolalities of 200 human tear prism fluid samples collected from two subjects were determined from their melting-point temperatures with the Clifton Nanoliter Osmometer by calibration with 200 standard solution samples (290 mOsm/kg). Comparisons were made between tear fluid osmolalities obtained using a single-sample simultaneous-recalibration method: 1) for tear samples collected using finely-drawn microcapillaries without biomicroscopy, vs secondly with biomicroscopic observation by illumination of only the sampling area on the inferior tear prism, the two collections separated by an interval of 10 min; and 2) for samples collected without biomicroscopy before, vs after a 10-min interval. Tear fluid collection using a biomicroscope resulted in values that were significantly lower than those collected without (overall mean = 299.5 and 306.6 mOsm/kg, respectively; p < 0.0001). The difference (7.1 mOsm/kg) may have resulted from mechanical, photic, and/or psychogenic reflex stimulation due to biomicroscopy, as the 10-min interval had no osmotic effect on samples collected without biomicroscopy. Based on these results from two subjects, we suggest that relatively rapid, repetitive collections of human tear prism fluid can be made without significantly disturbing the osmotic outcome. However, physiological representation of basic human tear fluid is more accurate by avoidance of reflex-inducing collection methods that were formerly considered unobtrusive. Basic human tear prism fluid is more hypertonic, by at least 7 mOsm/kg, than generally realized.

Humans↗
PubMed1993

Human basic tear fluid osmolality. II. Importance of processing strategy.

Osmolalities of 100 human inferior tear prism fluid samples collected from two subjects and 100 standard solution samples (290 mOsm/Kg) were determined from their melting-point temperatures with the Clifton Nanoliter Osmometer. Accuracy and reliability comparisons were made for endpoints obtained using a single-sample simultaneous-recalibration (SS/SR) strategy, vs a lowest-of-six periodic-recalibration (LS/PR) strategy. Tear fluid osmolality values based on the LS/PR strategy were significantly lower (hypotonic) than for the SS/SR strategy (overall mean = 302.4 and 307.8 mOsm/Kg, respectively; p < 0.0012). The mean difference (5.4 mOsm/Kg) resulted from the combined effects of machine drift and reduced reliability of endpoint determination for tear fluid in comparison to that of a homogenous standard solution. LS/PR osmolality was linearly correlated to SS/SR osmolality with a slope of 0.433 and the two endpoint strategies resulted in equivalent values at 298.4 mOsm/Kg. Eighty-four percent (84%) of individual osmolality readings were greater than 298.4 mOsm/kg, and an 'averaging-type' effect caused LS/PR osmolalities to be increasingly less than SS/SR values above this value. These outcomes from two subjects were approximated by a parallel statistical model. We suggest that physiological representation of basic human tear fluid is more accurate using the single-sample simultaneous-recalibration strategy. Basic human tear prism fluid is more hypertonic and has a greater within-subject range in normal (non-dry eye) humans than previously realized.

Humans↗
PubMed1993

Using continuous SVO2 to assess oxygen supply/demand balance in the critically ill patient.

To ensure that tissues are well oxygenated, oxygen supply and demand are now targets of therapy for the critically ill patient. This chapter reviews the physiologic determinants of oxygen supply, how it is threatened by respiratory or cardiac dysfunction or by hemorrhaged or anemic states, and how it can be assessed in individual patients. Activities and conditions that increase tissue oxygen demand are examined so that clinicians can identify those patients whose oxygen demands may be excessive and should be controlled. Failure of tissues to consume enough oxygen is explained in patients with critically low delivery or with the maldistributed blood flow state seen in sepsis. The monitoring of mixed venous oxygen saturation is examined as a method of tracking the threats to supply/demand balance and of guiding treatment that can support the adequate oxygenation of tissue.

Critical Care↗
PubMed1991

Recreational sports and the weekend athlete.

It is important to design an exercise program that provides an adequate amount of activity to attain maximal benefits at the lowest risk to the participant. Permanent lifestyle changes in eating and activity habits should be included in the primary goals of all programs.

Exercise↗
PubMed1990

The development of intimate relationships in late adolescence.

Adolescence is a time of burgeoning social relationships. Further, adolescents begin to develop the capacity to be intimate. Yet, little attention has been paid to the development of intimacy in adolescence. In this paper, relationship maturity, a developmental conception of intimacy, is presented as a unifying conceptual framework for understanding these intimate involvements as part of a major developmental process. Relevant empirical literature is reviewed. Issues addressed include: specific contexts of intimacy in adolescence, the role of gender in intimacy development, the interplay of identity and intimacy development, and the effects of social issues on this process.

Adolescent↗
PubMed1990

The physiologic basis for continuous mixed venous oxygen saturation monitoring.

Critically ill patients often have conditions that reduce oxygen delivery and increase oxygen demand. Routine nursing care, such as suctioning, positioning, and bathing, also increases the patient's oxygen demand. If the patient's oxygen demand exceeds the supply, dysrhythmias, hypotension, altered level of consciousness, and other adverse responses can occur. We describe use of continuous monitoring of mixed venous oxygen saturation (SvO2) as a tool to assess the patient's supply/demand balance during nursing care. The physiology of oxygen transport is reviewed, and oxygen delivery, reserve, and consumption are defined. Conditions that decrease oxygen delivery and increase oxygen demand are discussed, and the effects on SvO2 are illustrated. With continuous SvO2 monitoring, critical care nurses can see the effect of their nursing care on the patient's oxygenation and can adjust their care according to the patient's tolerance.

Critical Care↗
PubMed1990

Effects of endotracheal suctioning on mixed venous oxygen saturation and heart rate in critically ill adults.

The purpose of this multisite study was to determine the effects of endotracheal suctioning on mixed venous oxygen saturation (SvO2) and heart rate in 189 critically ill adults. One-pass, intermittent suction was applied for 10 or fewer seconds, with three prehyperoxygenation and three posthyperoxygenation breaths of 100% oxygen. Subjects at three hospitals (n = 127) underwent suctioning using hyperoxygenation with anesthesia bags and traditional suction catheters (open suction method). Subjects at one hospital (n = 62) underwent suctioning with hyperoxygenation by ventilator and in-line suction catheters (closed suction method). For subjects from all hospital sites combined, the SvO2 decreased from 67% to 64% (p = 0.001), a 4% change from baseline, and returned to baseline within 2 minutes. However, in subjects receiving the open method of suction, SvO2 dropped from 66% to 62% immediately after suctioning and returned to baseline within 4 minutes. In contrast, when the closed suction method was used, SvO2 rose from 67.7% to 67.86% immediately after suctioning, drifting upward to 71% for the next 2 minutes before dropping toward the baseline after 4 minutes. Mean heart rate increased from a baseline of 99 beats/min to 104 beats/min immediately after suctioning (p = 0.001), a 5% change from baseline, and gradually returned to baseline over the next 4 minutes. No significant differences were seen in heart rate between subjects having the open versus closed suction method. In conclusion, the closed suction method showed a higher SvO2 after endotracheal suctioning compared with the open suction method (p = 0.0001). Some form of hyperoxygenation before and after endotracheal suctioning is recommended.

Adult↗
PubMed1990

Effects of a lateral turn on mixed venous oxygen saturation and heart rate in critically ill adults.

The purpose of this study was to determine the effects of a lateral turn on mixed venous oxygen saturation (SvO2) and heart rate in 183 critically ill adults. Mean SvO2 decreased from a baseline of 67% to 61% saturation (p less than 0.0001) immediately after turning and gradually returned to 66% saturation (p less than 0.002) within 4 minutes. Mean heart rate increased slightly from a baseline of 99 beats/min to 102 beats/min (p less than 0.0001) immediately after turning and decreased slightly to 101 beats/min (p less than 0.0004) within 4 minutes. These statistically significant changes in SvO2 and heart rate were not clinically significant for most patients. However, physiologic responses to turning were highly variable. SvO2 reductions of 25% or more from baseline, heart rate increases and decreases of 10 beats/min or more, and signs of activity intolerance occurred in some patients. Nurses should expect critically ill patients to have a decrease in SvO2 of approximately 9% of baseline and small changes in heart rate after turning. These changes should be transient, with SvO2 and heart rate gradually returning toward baseline levels during the next 4 minutes. If turning triggers large or prolonged changes in SvO2 or heart rate, prompt repositioning and evaluation are needed to prevent adverse effects.

Critical Care↗
PubMed1990

Effects of a 1-minute back rub on mixed venous oxygen saturation and heart rate in critically ill patients.

In this study we evaluated mixed venous oxygen saturation (SvO2) and heart rate responses after a 1-minute back rub in 173 critically ill patients. The back rub was the third and last intervention in a study conducted in intensive care units at four hospitals. For this multiple-intervention study all patients were placed in a supine position to obtain baseline SvO2 and heart rate, then underwent suctioning via endotracheal tube, and were turned to a lateral position. After 15 minutes in a side-lying position, the subjects received a 1-minute back rub. Data were collected immediately after the back rub and at 1-minute intervals for 4 minutes. After the back rub, SvO2 decreased immediately from the mean baseline of 67% to 63% and gradually increased, returning to baseline by minute 4. The mean baseline heart rate of 99 beats/min increased to 103 beats/min immediately after the back rub and gradually decreased after massage, but remained higher than baseline by minute 4. Although the findings were statistically significant (p = 0.0001), these minimal physiologic changes do not represent clinical significance. Based on the findings, the back rub, a traditional nursing measure that can provide comforting touch, represented a minor stimulus affecting heart rate and oxygen demands in most critically ill patients. However, because of the variability found in heart rate and SvO2, individual responses need to be assessed.

Adult↗
PubMed1989

Injuring mechanisms of gunshot wounds.

The severity of injury in a gunshot wound is dependent on many factors, including the type of firearm; the velocity, mass, and construction of the bullet; and the structural properties of the tissues that are wounded. Knowledge of ballistics and an appreciation of the wounding potential of certain firearms and their ammunition can help clinicians anticipate the severity of a wound and raise the index of suspicion for occult but severe internal trauma.

Humans↗
PubMed1988

Marital conflict and adjustment: speech nonfluencies in intimate disclosure.

Speech nonfluency in response to questions about the marital relationship was used to assess anxiety. Subjects were 31 husbands and 31 wives, all white, college educated, from middle- to lower-middle-class families, and ranging from 20 to 30 years of age. Three types of nonfluencies were coded: filled pauses, unfilled pauses, and repetitions. Speech-disturbance ratios were computed by dividing the sum of speech nonfluencies by the total words spoken. The results support the notion that some issues within marriage are more sensitive and/or problematic than others, and that, in an interview situation, gender interacts with question content in the production of nonfluencies.

Adaptation, Psychological↗
PubMed1986

Intimacy maturity and its correlates in young married couples.

Intimate relationships, like the individuals who participate in them, are conceived of as following developmental processes. Five dimensions of intimacy--that is, relationship orientation, caring-concern, commitment, sexuality, and communication--are identified, and an approach to assessing relationship maturity on each of these dimensions is described. In a study of 31 young married couples, scores on each dimension of intimacy maturity were analyzed in relation to gender, gender role (as assessed through an adaptation of the Bem Sex Role Inventory; Bem, 1974), and marital adjustment. There were no significant differences between husbands and wives on any of the intimacy or marital adjustment scales and only a marginal difference on one gender role scale (agency). Patterns of correlations among intimacy, marital adjustment, and gender role scores varied by gender. Not only do there appear to be two marriages (his and hers) in every marriage, but the correlates of these marriages also vary.

Adaptation, Psychological↗