Biomedical subjects

R K Elswick

Publications and source records attributed to R K Elswick.

At least 37 records · Page 2Linked to original sources

PubMed1998

Effect of serum-clot contact time on clinical chemistry laboratory results.

The effect of serum-clot contact time on laboratory results was studied by dividing each blood specimen into four blood collection tubes. The control sera were separated from the clot within 30 min of the collection. The other tubes were incubated at 32 degrees C, and the sera were separated at 3, 6, and 24 h. The sera were stored at 4 degrees C and analyzed at the same time. The stability of the tests was determined by comparing the results of the 3-, 6-, and 24-h samples with the values from the 30-min samples. The acceptable limits around the 30-min values were derived from the analytical and intraindividual biological variation of the tests. A total of 63 analytes were studied. Potassium, phosphorous, and glucose were the least stable, and the serum should be separated from the clot within 3 h for these analytes. Albumin, bicarbonate, chloride, C-peptide, HDL-cholesterol, iron, LDL-cholesterol, and total protein should be separated within 6 h. The other analytes were stable for 24 h of serum-clot contact.

Analysis of Variance↗

PubMed1997

Interpretation of the odds ratio from logistic regression after a transformation of the covariate vector.

Logistic regression assumes a linear relationship between the logit and the continuous covariate. When the relationship is not linear, one can employ transformations of the covariate to satisfy the linearity assumption. We present an approach that allows interpretation of the odds ratio as it relates to the continuous covariate in its original metric. A numerical example illustrates the results.

Alcoholism↗

PubMed1997

The multivariate assessment of bioequivalence.

We propose an approach for comparing directly the reference and test blood concentration x time profiles of subjects in a bioequivalence trial under a crossover design. We compare the test and reference profiles via the construction of two regions, namely, an acceptable region based on the reference profile and another region based on reflecting the test profile about the reference profile. Also, we describe how to construct these regions if the assay for measuring the concentration has a lower limit of detection and how to adjust the reference and test concentrations of the n subjects participating in a bioequivalence trial. If the test and reference formulations are bioequivalent, then the area displaced by the latter region should be less than the area displaced by the acceptable region. Therefore, we construct a ratio of these areas for each subject. Then we calculate upper confidence limits for quantiles, either under theassumption of lognormality or based on a bootstrapping algorithm, to investigate population and/or individual bioequivalence.

Cross-Over Studies↗

PubMed1997

The effectiveness and safety of two cervical cytologic techniques during pregnancy.

BACKGROUND: There have been few studies documenting the optimal cervical cytologic technique in pregnancy. This study was initiated to investigate the effectiveness and safety of two standard techniques. METHODS: Two hundred twenty-two new obstetrical patients at a family practice residency program signed informed consent, were enrolled, and were randomized for cervical cytologic screening using either Zelsmyr Cytobrush and Ayre spatula or Dacron swab and Ayre spatula. The pathologists were blinded to the study, and results were reported with standard Bethesda System nomenclature. Patients were asked about complications at follow-up visits. Statistical analysis was performed using Fisher's exact test and the two-sample t test, with statistical significance set at P < .05. RESULTS: The Cytobrush-spatula technique yielded 95.6% (108/113) smears with adequate endocervical cells, as compared with 69.7% (76/109) of smears obtained with the Dacron swab and spatula (P = < .0001, odds ratio 9.38). Cytologic atypia, defined as noninflammatory cellular abnormalities, was uncovered on 15.9% (18/113) of the smears obtained with the Cytobrush and spatula technique and on 13.8% (15/109) of the smears obtained with the Dacron swab and spatula (P = .7082). The complication rate, which included spot bleeding and spontaneous abortion, occurred in 6.5% (7/108) of the smears obtained with the Cytobrush and 3.8% (4/105) of the smears obtained with the Dacron swab (P = .54). CONCLUSIONS: The Cytobrush-spatula technique significantly increased endocervical cell yield, did not increase detection of cytologic atypia, and did not increase the risk of adverse maternal or fetal outcomes when used for cervical cytologic screening during pregnancy. These results support the use of the Cytobrush-spatula technique over the swab and spatula for obtaining cervical cytologic smears in pregnancy.

Adult↗

PubMed1995

Screening for drinking problems by patient self-report. Even 'safe' levels may indicate a problem.

BACKGROUND: Physicians often screen their ambulatory patients for serious drinking problems by asking questions related to the quantity of alcohol that they consume. Never previously reported is whether this "quantitative" approach to screening can be used to effectively screen ambulatory patients for the presence of a serious drinking problem. METHODS: The project interviewed 510 patients attending an inner city general medicine practice with the alcohol module of the Diagnostic Interview Schedule, revised for the Diagnostic and Statistical Manual of Mental Disorders, Revised Third Edition. Collected data also included reported quantity, frequency, and recency of drinking. We then calculated the sensitivity, specificity, positive predictive values, and receiver operating characteristic curve for zero to two, three to five, six to 11, 12 to 23, and 24 or more standard drinks as reported by 155 patients who reported drinking within 30 days of their visit. RESULTS: Forty-eight of 155 active drinkers met the Diagnostic and Statistical Manual of Mental Disorders, Revised Third Edition criteria for alcohol dependence or abuse. Only five patients with an active diagnosis failed to report drinking within 30 days of their visit. The calculated area under the receiver operating characteristic curve for reported quantity was 0.81. The sensitivities of reported consumption decline with increasing drinking, while the specificities and positive predictive values rise. The report of drinking between six and 12 drinks per week was associated with a positive predictive value of 0.54 for an active Diagnostic and Statistical Manual of Mental Disorders, Revised Third Edition, diagnosis. CONCLUSIONS: Patient self-report of drinking can be used to screen actively drinking outpatients on the general medicine service for serious drinking problems. Further, in an urban general medicine outpatient population, even federally recommended levels of drinking may indicate a problem. Our data suggest that physicians' recommendations be adjusted for the setting in which they practice.

Alcoholism↗

PubMed1995

Test-retest reliability of the sensory organization test in noninstitutionalized older adults.

The purpose of this study was to determine the 1-week test-retest reliability of the Sensory Organization Test (SOT), using computer-generated scores and loss of balance (LOB) episodes in noninstitutionalized older adults. The SOT was administered to each subject on two separate days 1 week apart in an out-patient clinic. A volunteer sample of 40 individuals who were at least 65 years of age participated in this study. The main outcome measures were computer-generated scores for the first trial and the average of the three trials in each of the six sensory conditions of the SOT; computer-generated composite score of the six conditions; LOB on the first trial and any of three trials in each condition. The intraclass correlation coefficients (ICC) for the SOT first trial data ranged from .15 in Condition 3 to 0.70 in Condition 5. The ICCs for the SOT average of three trials ranged from 0.26 in Condition 3 to 0.68 and 0.64 in Conditions 5 and 6. Percent agreement was 77% to 100% for LOB on the first trial, as well as LOB on any of three trials of Conditions 1 through 6. As the conditions became more difficult, an increasing number of subjects experienced LOB. Analysis revealed fair to good test-retest reliability for computer-generated scores and good reliability for LOB across some conditions of the SOT. A modification to the current scoring system is suggested which would improve the reliability of the computer-generated scores of the SOT.

Aged↗

PubMed1995

Prospective clinical evaluation of mandibular implant overdentures: Part I--Retention, stability, and tissue response.

Seventeen subjects with preexisting conventional complete dentures were evaluated in this prospective clinical study. Two implants were placed bilaterally in the anterior mandible. In a crossover experimental design, the conventional dentures were modified, and the retention, stability, and tissue response for conventional dentures were compared with implant overdentures that had O-ring and magnet overdenture attachments for all subjects. The study indicated statistical superiority of the implant overdenture to the conventional denture. The O-ring attachment proved significantly better than the magnet attachment for retention and stability. The soft tissue response showed a slight but significant improvement with implant overdenture therapy.

Cross-Over Studies↗

PubMed1995

Prospective clinical evaluation of mandibular implant overdentures: Part II--Patient satisfaction and preference.

In a crossover experimental design, a prospective clinical study was performed with 17 subjects with existing complete dentures. After data collection, two implants were placed bilaterally in the anterior mandible. Conventional dentures were modified into implant overdentures by use of O-ring and magnet attachments. Each attachment was maintained with each subject for 6 months. Subjects responded to patient satisfaction and preference questionnaires about the conventional denture and each attachment. Subjects were satisfied with both attachment overdentures but showed a strong preference for the O-ring. Both attachments resulted in a significant increase in patient satisfaction when compared with the conventional denture.

Cross-Over Studies↗

PubMed1994

Efficacy and safety of 0.5% podofilox solution in the treatment and suppression of anogenital warts.

PURPOSE: For the patient-administered treatment of anogenital warts, 0.5% podofilox (podophyllotoxin), one of the active compounds of podophyllin, has been shown to be more effective than the vehicle alone. This study was designed to evaluate the safety and efficacy of 0.5% podofilox treatment followed by prophylaxis. PATIENTS AND METHODS: A total of 103 patients were entered in stage 1 of the study. Stage 1 was an open label study, and patients self-administered 0.5% podofilox twice daily for 3 consecutive days per week for 4 weeks. A total of 100 patients remained available for efficacy and safety analyses. At the end of stage 1, patients who had a complete response proceeded to stage 2 of the study. Patients who had a 50% to 99% reduction in measured total wart area were offered cryotherapy every 10 days, up to 5 times. If cleared of warts, they were also entered into stage 2. A total of 57 patients were enrolled into stage 2, a double-blind, randomized, placebo-controlled prophylactic study of 0.5% podofilox self-administered once daily for 3 days per week for 8 weeks, on the sites of healed warts. A total of 45 patients in stage 2 were available for efficacy analysis. RESULTS: By the end of stage 1, 68% of the warts had disappeared, and 29 of 100 patients (29%) had a complete response. A total of 49 patients had a 50% or greater improvement in wart area and underwent cryotherapy. Rates of local side effects after 1 week of treatment were 57% for inflammation, 39% for erosion, 47% for pain, 48% for burning, and 44% for itching. However, these symptoms and signs were mostly mild to moderate in intensity and diminished over time. Therefore, overall treatment was well tolerated. In stage 2, only 4 of 21 patients (19%) in the podofilox group experienced a recurrence as opposed to 12 of 24 (50%) in the placebo group (P = 0.031). As in stage 1, the side effects were modest, and the drug was well tolerated. CONCLUSION: This study confirms the efficacy and good tolerance of 0.5% podofilox in the treatment of anogenital warts. It also establishes the safety and superior efficacy of patient-administered podofilox over the vehicle alone as prophylaxis against recurrence of lesions. Although long-term efficacy and tolerance remain to be established, podofilox appears to be a useful agent in the control of this disease.

Adult↗

PubMed1994

Safety and efficacy of rectal prochlorperazine for the treatment of migraine in the emergency department.

STUDY OBJECTIVE: To assess the safety and efficacy of rectal prochlorperazine in the treatment of acute migraines. DESIGN: Randomized, double-blinded, placebo-controlled study. SETTING: Emergency department of an inner-city university hospital. PARTICIPANTS: ED patients with documented diagnosis of migraines. INTERVENTIONS: Vital signs and level of alertness were monitored immediately before drug administration and 120 minutes after dosing. Pain intensity and adverse events were monitored immediately before drug administration and at 30, 60, and 120 minutes after dosing. RESULTS: A positive outcome was defined as a pain score less than or equal to 5 on a 10-point scale or a 50% reduction in pain intensity from baseline at 120 minutes after dosing. All patients treated with prochlorperazine suppositories experienced a positive treatment outcome; only 50% of patients treated with placebo experienced a positive result at 120 minutes after dosing (P = .016). Pain intensity scores were significantly lower in the prochlorperazine group at 120 minutes (P = .018). There were no adverse reactions in either group, and there were no significant differences in vital signs or levels of alertness between groups. Patients who failed therapy were given rescue medication 120 minutes after dosing. CONCLUSION: Prochlorperazine administered as a 25-mg rectal suppository provides excellent pain relief within 2 hours in patients with acute migraines.

Acute Disease↗

PubMed1994

Drug-using and nonusing women: potential for child abuse, child-rearing attitudes, social support, and affection for expected baby.

Eighty pregnant women (25 substance using, 55 nonusing) from an American prenatal clinic serving lower-income to working-class women responded to questionnaire measures of child-rearing attitudes. The drug users' primary substance of misuse was cocaine (68%), alcohol (16%), amphetamines (12%), or sedatives (4%); polydrug use was documented for 80% of the women. The two (user and nonuser) groups were not different on demographic (age, race, marital status, education, SES, source of income) or obstetrical factors (number of pregnancies, number of children). Drug-using women scored significantly higher on a measure of child abuse potential; more than half scored in the range of clinical criterion for extreme risk. As their babies were not yet born, no actual physical abuse was documented, only a higher potential for abuse. The subgroup who were both drug users and had lower social support scored higher on child abuse potential than all other subgroups. The drug users also had lower self-esteem scores than the nonusers. The two groups did not differ on measures of overall social support, authoritarian/democratic child-rearing beliefs, or affection for the expected baby.

Adult↗

PubMed1993

A program of screening and prompting improves short-term physician counseling of dependent and nondependent harmful drinkers.

BACKGROUND: Physicians in the general medical setting commonly encounter but rarely counsel patients with dependent or harmful drinking behaviors. We tested whether providing physicians with their patients' results on the alcohol module of the Diagnostic Interview Schedule and counseling directives would prompt them to counsel these patients. METHODS: We randomly assigned 83 first-, second-, and third-year medical residents to receive or not to receive diagnostic information and counseling directives on 214 patients who reported at least one symptom of alcohol impairment as defined in the Diagnostic and Statistical Manual of Mental Disorders, Third Edition. Using binary logistic regression, we examined the effect of specific covariables on rates of physician counseling. These variables included physician information status, patient gender, and drinking disorder severity and recency. We also examined the effect of physician prompting on counseling of female patients, patients with inactive disorders, and nondependent but harmful drinkers. We determined counseling by post-visit patient interviews. RESULTS: Physician prompting, dependent drinking, and recent disorder activity were significant correlates of physician counseling (P < .05), while male gender was a marginally significant correlate (P = .08). Informed physicians counseled female patients, harmful but nondependent drinkers, and patients with inactive disorders more often than their uninformed colleagues, although only the last variable achieved statistical significance. CONCLUSIONS: Providing physicians with the results of the Diagnostic Interview Schedule and counseling directives resulted in short-term improvement in their rates of counseling patients with a history of dependent or nondependent but harmful drinking. Further research is necessary to determine long-term gains in rates of physician counseling and improvements in the course of these patients.

Alcoholism↗

PubMed1992

Assessment of the drug interaction between intravenous nitroglycerin and heparin.

OBJECTIVE: To assess whether a clinically significant interaction occurs between heparin and nitroglycerin (NTG). METHODOLOGY: Activated partial thromboplastin time (APTT) was measured in patients with unstable angina who were stabilized on intravenous NTG and heparin just prior to weaning the NTG infusion, and one and four hours after stopping the NTG. RESULTS: In 22 heparin-treated patients (20 men, 2 women; aged 56.7 +/- 10 years; weight 79.5 +/- 15 kg), the APTT ratio was inversely related to the dose of NTG (slope = -0.003; p < 0.05). However, there were no significant differences between the APTT values measured before and after discontinuation of NTG (p = 0.8511). CONCLUSIONS: Our study demonstrates a clinically insignificant interaction between NTG and heparin at NTG doses commonly used in patients.

Aged↗

PubMed1992

Electroencephalographic sleep and mood during cocaine withdrawal.

We report on nine patients between the ages of 21 and 39 years who were admitted to an inpatient substance abuse treatment unit for cocaine treatment. The patients' sleep was studied in the laboratory for 4 nights during the first week, and 2 nights during the second and third weeks of their hospitalization. Daily mood ratings, cocaine craving scores and sleep logs were also recorded on each patient. During the first week of withdrawal, these patients had a markedly shortened REM latency, an increased REM sleep percentage, a very high REM density and a long total sleep period time. During the third week, REM latencies were very short and total percentage of REM sleep was increased. By week three of withdrawal the sleep continuity pattern was similar to that found in chronic insomnia, with a long sleep latency, an abnormally increased total time awake after sleep onset and a poor sleep efficiency. The subjects' ratings of cocaine craving, total POMS scores and depression fell precipitously after the first week of withdrawal and were at sub-clinical levels by week three of withdrawal.

Adult↗

PubMed1992

Conditioning of Nude bone marrow increases in vitro migration to thymus supernatant.

The thymus must be continuously seeded by cells termed prothymocytes in order to maintain normal T-cell development (Scollay et al. 1986). Using parabiotic studies, the source of prothymocytes appears to be either from the fetal liver or the adult bone marrow (Roderwald et al. 1992). The ability of the body to distinguish self from non-self and mount a functionally mature immune response is dependent upon the intrathymic education of these cells. Therefore, it is apparent that successful migration of prothymocytes into the thymus is an inescapable event in the development and maintenance of the immune system. Utilization of the athymic Nude mouse is a valuable asset in the elucidation of the mechanisms influencing the migration of bone marrow cells into the thymus. Its aberration enables investigators to examine the effect of thymic factors on cells previously devoid of thymic influence. In an attempt to understand the migration of normal prothymocytes into the thymus, we analyzed the in vitro migration of athymic bone marrow cells towards newborn thymus supernatant. Adult athymic murine bone marrow cells were incubated in either thymus supernatant or media and allowed to migrate toward one or the other. Similar control experiments were performed using CBA adult mice. Results indicate that athymic bone marrow migration towards both supernatant and media can be restored to control levels after incubation in thymus supernatant.

Animals↗

PubMed1991

Efficacy of bladder training in older women with urinary incontinence.

The efficacy of bladder training was evaluated in a randomized clinical trial involving 123 noninstitutionalized women 55 years and older with urinary incontinence. Subjects were urodynamically categorized as those with urethral sphincteric incompetence (N = 88) and those with detrusor instability with or without concomitant sphincteric incompetence (N = 35). Bladder training reduced the number of incontinent episodes by 57%; the effect was similar for both urodynamic diagnostic groups. The quantity of fluid loss was reduced by 54%. This was greater for patients with detrusor instability than for those without it. Diurnal and nocturnal voluntary micturitions were also reduced. The effect on nocturnal micturition, however, was not observed in subjects with unstable detrusor function. It is recommended that bladder training be considered as an initial step in treatment of women with urinary incontinence. Provided prior comprehensive clinical evaluation is done, it can be prescribed without the need for urodynamic characterization.

Aged↗

PubMed1991

A double-blind, randomized trial of 0.5% podofilox and placebo for the treatment of genital warts in women.

Patient-applied formulations of 0.5% podofilox (podophyllotoxin) were evaluated for the treatment of external genital warts in a double-blind, placebo-controlled study. Seventy-two women were enrolled and, using a randomized, computer-generated list, assigned to receive either active drug or placebo in a 2:1 ratio. Patients were instructed to apply the medication to their external warts twice each day for 3 consecutive days, followed by 4 days without treatment. This cycle was repeated at weekly intervals for a maximum of 4 weeks (and a minimum of 2 weeks). Patients were evaluated weekly for the first month and then at weeks 6 and 10. The number of warts present was recorded and the overall improvement was assessed. The treated area was examined, the patients were questioned about any adverse effects, and standard hematologic/biochemical studies were conducted. The final results showed that podofilox cleared 74% of the total wart count, compared with an 18% regression in the placebo group (P less than .001). The investigators' assessments of improvement correctly distinguished active drug from placebo at every observation point. Local untoward effects were minor and transient. There was no evidence of systemic effects. It is concluded that patient-applied podofilox is a safe and effective therapy for genital condylomata in women. When available, this drug will simplify the treatment of genital warts by providing a patient-applied alternative therapy.

Adolescent↗

PubMed1990

Time-motion study of intravenous ranitidine admixtures.

This study determined the total preparation time, cost, and contamination rate associated with preparing 50-mL admixtures of ranitidine 50 mg from each of the following commercial source vials: 50 mg/2 mL unit-dose vial (treatment A), 50 mg/2 mL 10 mL multidose vial (treatment B), and 50 mg/2 mL 40 mL multidose vial (treatment C). The study consisted of two separate phases: phase I extemporaneous compounding and phase II batch manufacturing. Twelve technicians prepared ten admixtures from each source vial during each phase. All admixtures were tested for sterility; bacterial contamination was not observed. Multidose vials saved approximately $197 per 200 admixtures. Drug and personnel costs were reduced when batch manufacturing with 40-mL multidose vials was compared with extemporaneous compounding with unit-dose vials. Our study showed that multidose vials decreased the total preparation time and cost for making ranitidine admixtures during both extemporaneous compounding and batch manufacturing by reducing setup time, preparation time, and drug procurement cost.

Drug Compounding↗