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Biomedical subjects

R M Warner

Publications and source records attributed to R M Warner.

At least 19 recordsLinked to original sources
PubMed2004

Protean manifestations of intravenous drug use.

Intravenous drug use is an increasing social problem. Repeated venepunctures, injection of insoluble substances and needle sharing habits in intravenous drug users result in complications leading to admissions under various medical specialities. Many of these patients, however, manifest soft tissue wounds requiring specialised care from plastic surgeons. Typical presentations include injection site related abscess, cellulitis, necrotising fasciitis and non-healing wounds. We present a series of 11 consecutive cases treated in our unit over a six-month period, to highlight the varied clinical presentations and potential difficulties in their management.

Adult↗
PubMed2003

An easy and accurate preoperative method for determining tibial nail lengths.

Estimating the correct nail length for solid tibial nails can be problematic. Most techniques reported in the literature for determining tibial nail length are not accurate. In a retrospective study of 16 patients in our unit, only three had ideal nail sizes. In these patients, as part of phase I of our study, we measured their normal leg's length from knee joint line to ankle joint line. An ideal nail length for each of these patients was estimated from a whole length radiograph of the nailed tibia. Comparing these two data, we found that deducting 20 mm from the leg measurement gave appropriate nail lengths. We also compared this with three other anthropometric measurements; tibial tuberosity to medial malleolus, joint line to medial malleolus and olecranon to head of V metacarpal head distance. The joint line to joint line measurement was the most reliable and showed the best correlation with ideal nail lengths (0.982). In phase II, a prospective study on 15 patients, we used the joint line to joint line measurement to determine nail sizes. A postoperative review of the radiographs showed all the nails to be of adequate length. This strengthened the fact that the joint line to joint line measurement is the most accurate and easy method to determine tibial nail lengths.

Anthropometry↗
PubMed2000

External aperture of the vestibular aqueduct in Meniere's disease.

OBJECTIVE: To study the relationship of the length of the external aperture of the vestibular aqueduct and the ratio of the summating potential and action potential (SP:AP) in patients with Meniere's disease. STUDY DESIGN: Retrospective case study. SETTING: Neurotology referral center. PATIENTS: Fifty-four patients with Meniere's disease and nine control subjects without Meniere's disease. INTERVENTION: The external aperture of the vestibular aqueduct was measured from a three-dimensional surface reconstruction computed tomography scan. Transtympanic electrocochleography was performed on patients with Meniere's disease. MAIN OUTCOME MEASURE: The length of the external aperture of the vestibular aqueduct in the Meniere's disease ears was related to the SP:AP ratio in the Meniere's disease ears and compared with controls. RESULTS: The average length of the external aperture was 3.79 +/- 2.92 mm in Meniere's disease ears and 5.35 +/- 1.73 mm in the control ears (p < 0.05). An enlarged SP:AP ratio was found in 95% of ears in the group with nonvisible external apertures of the vestibular aqueduct, 91% of ears in the <5 mm group, 58% of ears in the 5-7 mm group, and 29% of ears in the >7 mm group (chi-square = 24.814; p = 0.000). CONCLUSIONS: The length of the external aperture of the vestibular aqueduct in patients with Meniere's disease is significantly shorter than in those without Meniere's disease. Endolymphatic hydrops, evidenced by an enlarged SP:AP ratio, was related to the length of the external aperture of the vestibular aqueduct. The shorter the external aperture, the more often the SP:AP ratio was enlarged. A short or nonvisible external aperture of the vestibular aqueduct is a predisposing factor to the development of Meniere's disease.

Audiometry, Evoked Response↗
PubMed2000

Family stressors as predictors of codependency.

Codependency has been defined as an extreme focus on relationships, caused by a stressful family background (J. L. Fischer, L. Spann, & D. W. Crawford, 1991). In this study the authors assessed the relationship of the Spann-Fischer Codependency Scale (J. L. Fischer et al., 1991) and the Potter-Efron Codependency Assessment (L. A. Potter-Efron & P. S. Potter-Efron, 1989) with self-reported chronic family stress and family background. Students (N = 257) completed 2 existing self-report codependency measures and provided family background information. Results indicated that women had higher codependency scores than men on the Spann-Fischer scale. Students with a history of chronic family stress (with an alcoholic, mentally ill, or physically ill parent) had significantly higher codependency scores on both scales. The findings suggest that other types of family stressors, not solely alcoholism, may be predictors of codependency.

Adolescent↗
PubMed1995

Cardiovascular reactivity and positive/negative affect during conversations.

Systolic and diastolic blood pressures (SBP, DBP) were measured for 70 college students before, during and after informal dyadic conversations. Participants rated the positive and negative affect they experienced during conversation. SBP and DBP increased significantly from baseline to conversation. Increases in SBP and DBP were associated with more positive affect and unrelated to negative affect. Blood pressure measures taken one week later provided a more useful assessment of resting levels than measures taken before the conversation. Relationships between BP reactivity and positive affect remained significant after controlling for resting levels of BP, amount of talk during conversation, and sex of speaker in hierarchical regression. Blood pressure elevation during social interaction may be associated with involvement or enthusiasm, rather than emotional distress; this association is not simply an artifact of talkativeness. We suggest that cardiovascular reactivity in healthy young adults engaged in nonthreatening conversations may be a widespread phenomenon and not necessarily pathological.

Adult↗
PubMed1991

Graduate and post-graduate medical education with the synchronous systems model.

Behavioral sciences have an important new role, particularly in medicine and prevention (Revans, 1990; Starr, 1982). A decade ago when the ideology of medical care shifted from a biomedical to a biopsychosocial model, behavioral and social factors ascended in importance in modern health concerns (see Engel, 1977). Now, a living systems model called Synchronous Systems (Jasnoski & Schwartz, 1985) incorporates environmental (including the social and physical) along with physiological and psychological factors into its structure. The environment has been gaining recognition as an important determinant in health, disease, and wellness (Daniel, 1990; Demick & Wapner, 1990; Lawton, 1990; Stokols, 1990). The phrase "Synchronous Systems" departs from the traditional linear thought patterns to depict contemporaneous occurrences. Synchrony refers to simultaneous experiences or events, with an emphasis on healthy, congruent process and function. Positive, beneficial process in human functioning emphasizes prevention as found in public health efforts but refers also to dysfunctional and recuperative foundation of medicine as a departure from the healthy norm. These process and functional dynamics in the Synchronous Systems Model derive conceptually from systems theory, specifically from control and cybernetic theories (Cannon, 1932; Weiner, 1948). The dynamic complexity of health in the whole human system, which also incorporates the environment, requires synthesis of knowledge from the biological, social, behavioral, and ecological sciences. This article provides the fundamentals of the structural and functional synthesis possible in the Synchronous Systems Model. Its direct application to multidisciplinary research is also presented along with its specific application to medical education, policy, research, and service delivery.

Curriculum↗
PubMed1989

Sensitive analysis of the mycotoxin zearalenone and its metabolites in biological fluids by high-performance liquid chromatography alpha.

A method is described for the analysis of zearalenone and its metabolites, alpha- and beta-zearalenol, in small volumes (0.5-2.0 ml) of biological fluids including milk, blood, plasma, urine and bile, using high-performance liquid chromatography with fluorescence detection. Isolation of the toxins from biological fluids was achieved using a series of pH-controlled solvent extractions. Detection limits for zearalenone and alpha-zearalenol were 1 ng/ml, and for beta-zearalenol ca. 5 ng/ml, both at a signal-to-noise ratio of 3. In bile, however, the detection was ca. five times less sensitive owing to interfering substances. Recoveries at low ng/ml concentrations were highest from urine (87-94%) and plasma (85-93%), slightly lower from whole blood (78-88%) and milk (75-84%), and lowest from bile (66-77%).

Animal Feed↗
PubMed1988

Individual differences in vocal activity rhythm: fourier analysis of cyclicity in amount of talk.

Speakers in informal conversations tend to alternate regularly between lower and higher amounts of talking; the periods of these low/high activity cycles are on the order of 3, 6, and 15 minutes. Statistically significant periodicities occurred in 55% of the conversations studied. The periodograms that describe the partition of variance among periodic components show consistent individual differences in the cyclic patterning of vocal activity. Discriminant analysis used the amount of variance accounted for by each of the 12 lowest-frequency periodic components as discriminating variables to see whether speakers could be identified on the basis of the cyclic patterns in vocal activity. Speakers were discriminated and classified at levels well above chance. This suggests that there are consistent individual differences among speakers in the length of cycles in amount of talk.

Activity Cycles↗
PubMed1984

Thermal balance and sleep state in the newborn.

The thermal balance of 35 healthy newborn term infants was measured during active (AS) and quiet sleep (QS) in thermoneutral and cool environments. As conductive heat loss was found to be small, some 3% of the total, only the effective surface area involved in insensible heat loss was used in calculating insulation values. This area varied with posture, being 84% of the total when supine and 70% in the prone, crouched position. In thermoneutrality oxygen consumption rose significantly when the change was from QS to AS, but the associated fall in insulation did not reach significance. In a cool environment the differences were in the same direction but of greater magnitude, and the decrease in insulation of 17% found in AS was significant.

Body Surface Area↗
PubMed1983

Synchronized cycles in ventilation and vocal activity during spontaneous conversational speech.

Ventilation was monitored in 10 human subjects during spontaneous conversational speech to determine whether oscillatory patterns in vocal activity were correlated with oscillatory patterns in ventilation. The 10 subjects were studied as five pairs (or dyads), and spontaneous conversation occurred within each dyad. Patterns with cycle times ranging from 16 to 512 s were studied. Of the 10 subjects in this study, 1 subject showed a very striking pattern of mutual entrainment between low-frequency oscillations in ventilation and in vocal activity, 5 subjects showed somewhat weaker coordination between oscillations in ventilation and vocal activity, and the remaining 4 subjects showed little or no coupling between ventilation and vocal activity. Mutual entrainment between rhythms in ventilation and vocal activity can occur, but this study suggests that there may be great differences among individuals in the degree to which ventilation covaries with vocal activity in spontaneous conversational speech. We hypothesize that degree of entrainment is affected both by the strength of any spontaneous ventilatory patterns and by the extent to which any individual's spontaneous ventilatory pattern matches that of his conversational partner.

Adult↗
PubMed1981

CT demonstration of fat tissue in malignant renal neoplasms: atypical Wilms' tumors.

It has been implied that the recognition of fat in a renal tumor suggests that the lesion is benign. Several authors have suggested tht angiomyolipoma is the only common renal tumor containing mature adipose tissue. Other neoplasms may contain mature fat that can be identified with current diagnostic imaging techniques. Under discussion is our experience with Wilms' tumor containing a predominance of adipose tissue.

Adipose Tissue↗
PubMed1981

High performance liquid chromatographic method using fluorescence detention for quantitative analysis of zearalenone and alpha-zearalenol in blood plasma.

A sensitive, high performance liquid chromatographic method is described for quantitative determination of zearalenone and alpha-zearalenol in blood plasma. Blood plasma is extracted with 2-propanol in ether, the extract is evaporated to dryness, and the residue is dissolved in 0.18N NaOH. The aqueous phase is washed with chloroform, dichloromethane, and benzene, neutralized with 0.10M H3PO4, and extracted with benzene. The extract is evaporated, dissolved in methanol, and injected onto a reverse phase column containing LiChrosorb RP-8 under the following conditions: methanol-acetonitrile-water mobile phase, fluorescence detector, excitation wavelength 236 nm, and 418 nm cut-off emission filter. The limit of detectability (twice background) is 0.5 ng standard which is equivalent to 0.6 ng standard/mL blood plasma. Linear standard curves are observed over the range of 0-35 ng of injected zearalenone and alpha-zearalenol. The recoveries from blood plasma are 76-101% in the range of 1.5-6.0 ng standard/mL blood.

Chromatography, High Pressure Liquid↗
PubMed1979

Effect of feeding on neonatal oxygen consumption.

Oxygen consumption was measured in 9 short-gestation infants before feeding and for an hour after, using a closed-circuit metabolism chamber. Using the same system, O2 consumption of 9 term infants was measured for varying periods, beginning one hour from the end of the last feed. In the short-gestation infants a rise was found in the 15--45 minutes after feeding; O2 consumption then fell, and after 60 minutes had reached prefeed levels. The term infants showed no decrease with time after the first hour, as would be expected if the effect of feeding on O2 consumption extended beyond this. It is concluded that increased O2 demand after appropriate feeding does not extend beyond one hour postprandially.

Eating↗
PubMed1978

Oxygen consumption and neonatal sleep states.

1. In thirty full-term infants in the first week of life, nursed in a constant volume, closed-circuit metabolism chamber in a neutral thermal environment (31.5-33.5 degrees C), measurements were made of oxygen consumption ( V(O2)) during periods of rapid eye movement (REM) sleep and non-rapid eye movement (NREM) sleep.2. The mean V(O2) during REM sleep was 5.97 ml. kg(-1). min(-1). In NREM sleep the mean V(O2) was 5.72 ml. kg(-1). min(-1). This difference was significant (paired t test P < 0.05).3. When the direction of sleep state change was taken into account the difference in V(O2) between the two states was much less when REM sleep preceded NREM than when the change was in the opposite direction. In nineteen infants in whom the change was from REM to NREM the difference in V(O2) (6.18 and 6.03 ml. kg(-1). min(-1)) was not significant (P > 0.05). The mean difference when the sleep state change was from NREM to REM was significant (P < 0.01), the values being 5.54 and 5.81 ml. kg(-1). min(-1) respectively.4. In the NREM state, a gradual diminution of V(O2) with time was consistently found. This was not the case in REM sleep.5. In twelve infants studied in a cool environment (29 +/- 0.5 degrees C) V(O2) during REM sleep was 7.77, and during NREM sleep it was 6.58 ml. kg(-1). min(-1), (P < 0.001). Thus even the maximum difference found in a neutral thermal environment of 6.6% was significantly increased to 14.9% (P < 0.01) with mild thermal stress.6. No consistent changes in V(O2) with time were found in either REM or NREM sleep in twelve infants studied in a cool environment, in contrast to the findings in thermal neutrality

Humans↗