PubMed Health⌕ Search

Biomedical subjects

R J Markert

Publications and source records attributed to R J Markert.

At least 19 recordsLinked to original sources
PubMed1997

Is in vivo measurement of size of polyps during colonoscopy accurate?

BACKGROUND: Accurate measurement of polyp size during colonoscopy is important because of the direct correlation of size with colon cancer. Major studies of colorectal neoplasms have measured polyp size differently. It is also well documented that endoscopists underestimate polyp size frequently. The goal of this prospective study was to determine which one of the five methods of estimating polyp size during colonoscopy is most accurate. METHODS: One hundred colon polyps were measured by means of visual estimation, open biopsy forceps methods, linear probe, a ruler immediately after excision, and after fixation in formalin. The size of the polyps measured outside the body immediately after excision was considered the "gold standard" against which all measurements were compared. RESULTS: Forty-seven polyps were 5 mm or less in diameter, 33 polyps were 5.01 mm to 10 mm, and 20 polyps were more than 10 mm in size. For all polyps the mean difference versus the actual size of the polyps was 3.4% for linear probe, 6.4% for visual estimation, and 12.3% for the forceps. CONCLUSION: Measurement of polyp size by linear probe agreed best with the actual polyp size, followed closely by visual estimation. The open biopsy forceps method was the least accurate.

Adenoma↗
PubMed1997

Predictive factors for high mortality in hypernatremic patients.

Hypernatremia (serum sodium level of > 145 mEq/L) is associated with high mortality. This study reports an analysis of mortality in 116 patients with hypernatremia from two large university-affiliated teaching hospitals. The purpose was to identify factors predictive of high mortality in hypernatremic patients. Medical records were reviewed to obtain the following data: serum sodium (Na+) levels; systolic (S) and diastolic (D) blood pressure (BP) at the time of admission and throughout the hospital course; status of cognitive function; and type of fluid administered. The patients were divided into two groups: expired and survived. Seventy-seven of 116 patients (66%) expired, while 39 patients (34%) survived and were discharged from the hospital. The mean age and gender for patients who died (70.9 +/- 15.4 years, 90% men) were not different from those who survived (66.4 +/- 17.3 years, 87% men). For the serum Na+ levels recorded at three different times (early, peak, and late), mean late serum Na+ level during hospital course was significantly higher in patients who died than in those who survived (151.2 +/- 9.2 v 143.1 +/- 8.0 mEq/L, respectively; P < .001). Mean admission serum Na+ level (154.9 +/- 5.5 v 155.1 +/- 7.7 mEq/L, respectively) and mean peak serum Na+ level (157.5 +/- 6.5 v 156.8 +/- 9.4 mEq/L, respectively) were not different between the two groups. Both SBP and DBP at the time of admission (P < .05) and throughout the hospital course (P < .001) were significantly lower in the patients who died than in those who survived. The cognitive abnormalities consisting of confusion, obtundation, and speech abnormality were significantly (P < .05) higher in the expired patients than in those who survived. Normal (isotonic) saline was used significantly more frequently (P < .00001) in patients who expired than in those who survived. Thus, this study suggests that a persistently elevated serum Na+ level (possibly caused by prolonged infusion of normal saline) in association with protracted hypotension portends a dismal prognosis in hospitalized hypernatremic patients.

Aged↗
PubMed1997

Comparison of manual versus automated blood pressure measurements in treated hypertensive patients.

This study assesses differences in blood pressure (BP) levels prospectively between office (manual) measurement and ambulatory blood pressure monitoring (ABPM) in 70 treated, essential, hypertensive patients. The objective was to determine whether ABPM is superior to office measurement for assessing adequacy of therapy. Twenty-four patients received monotherapy and 46 received multiple therapy. Thirty-five patients were administered medication in the morning only, whereas 33 were administered medication in the morning and evening both. Mean systolic BP by manual method was identical to that obtained by ABPM (141.98 +/- 14.98 mm Hg versus 141.46 +/- 16.33 mm Hg, respectively). However, mean diastolic BP by manual method was significantly higher than that obtained by ABPM. (90.38 +/- 9.01 mm Hg versus 86.69 +/- 10.65 mm Hg, respectively; P < 0.001). Significant correlations (P < 0.01) were found between the BP levels measured by these two methods, although individual readings differed by 10 mm Hg or more systolic and by 5 mm or more diastolic in many subjects. No significant differences were noted in BP levels measured by either method for patients treated by monotherapy or multiple therapy, and none were noted whether they were taking medication in the morning or in both the morning and evening. In addition, no differences were noted in BP levels using either method for race. Thus, this study shows that the office measurement is grossly similar to ABPM for assessment of adequacy of therapy in treated hypertensive patients whose blood pressure is controlled adequately. However, ABPM is found to be superior to office measurement in identifying hypertensive patients whose blood pressure is not controlled adequately or is uncontrolled.

Adrenergic beta-Antagonists↗
PubMed1995

Evaluation of early (5 to 6 hours) iodine 123 uptake for diagnosis and treatment planning in Graves' disease.

BACKGROUND: Twenty-four-hour radioactive iodine uptake measurements necessitate extra visits and time delays in diagnostic confirmation of and therapy planning for hyperthyroid patients. We evaluated the early (5 to 6 hours) measurement of iodine 123 uptake (EU) to predict late (24 hours) uptake (LU) and assessed its value in the management of hyperthyroidism. METHODS: We conducted a prospective study in 51 previously untreated hyperthyroid and 27 euthyroid patients (initial evaluation group). Patients underwent both 6- and 24-hour 123I uptake measurements. A subsequent 21 patients with Graves' disease (confirmation group) were evaluated in light of regression data generated in the initial evaluation group. RESULTS: An EU value of greater than 20% had a sensitivity of 100%, a specificity of 96%, and a positive predictive value of 98% for the diagnosis of hyperthyroidism and was superior to the most predictive LU value (> 30%), which had a sensitivity of 98%, a specificity of 89%, and a positive predictive value of 94%, in distinguishing the hyperthyroid patients from euthyroid patients or those with subacute thyroiditis. Regression analysis revealed that the 24-hour uptake of the hyperthyroid patients could be predicted from the early measurement with the following formula: LU = 28.94 + 0.584 (EU). The measured EU of the confirmation group was used to calculate a predicted LU with use of this formula. Measured LU and predicted LU correlated well (r = .85, P < .001). Iodine 131 dose calculations were performed post hoc; LU calculated doses correlated with predicted LU doses (r = .91, P < .001). Mean dose differences were small. CONCLUSIONS: The EU of 123I can replace 24-hour uptake measurements. Early uptake measurement is reliable and clinically useful for diagnosis confirmation and treatment planning in thyrotoxic patients.

Adolescent↗
PubMed1995

A prospective controlled evaluation of endoscopic detection of angiodysplasia and its association with aortic valve disease.

BACKGROUND: In view of controversy about the association of aortic stenosis and angiodysplasia of the gut, we performed a prospective, controlled study to evaluate the relationship between aortic valve disease and gastrointestinal angiodysplasia. METHODS: Forty patients who had endoscopy for clinical indications such as gastrointestinal bleeding, anemia, polyps, colon cancer, and dyspepsia, and who were found to have angiodysplasia of the gastrointestinal tract, underwent two-dimensional and Doppler echocardiography. Thirty-seven controls matched for age, sex, indication, and nature of endoscopic examination, but without angiodysplasia, underwent similar echocardiographic examination. RESULTS: None of the patients in either group had aortic stenosis. The prevalence of aortic sclerosis, aortic insufficiency, and low left ventricular ejection fraction was similar in patients with and without angiodysplasia. CONCLUSIONS: This study does not support the role of aortic valve disease as the cause of angiodysplasia of the gastrointestinal tract. A subgroup of patients with angiodysplasia with aortic sclerosis, with or without other valvular disease (but none with aortic stenosis), had increased prevalence of gastrointestinal bleeding when compared with controls. When aortic valve disease or decreased left ventricular ejection fraction were analyzed as independent predictors, none of them in and of itself appeared to be a factor in bleeding from these gastrointestinal lesions.

Aged↗
PubMed1994

A comparative study of eight fecal occult blood tests and HemoQuant in patients in whom colonoscopy is indicated.

BACKGROUND AND OBJECTIVE: Some studies suggest that immunochemical fecal occult blood tests (FOBTs) and HemoQuant are more efficient at detecting fecal occult blood than the commonly employed Hemoccult II (guaiac) test. We undertook this study to determine whether an immunochemical test either alone or in combination with a guaiac test gives efficiency superior to the Hemoccult II test in predicting significant gastrointestinal tract disease. DESIGN: Criterion standard, prospective, blinded. SETTING: Referral population of ambulatory patients at an institutional and a private hospital. PATIENTS: Eight-one patients referred to a gastroenterologist and in whom colonoscopy was indicated. INTERVENTIONS: While on a restricted diet, patients made preparations for FOBTs from three consecutive bowel movements. Patients then underwent colonoscopy. Polyps larger than 1 cm in size, carcinoma of the colon, peptic ulcers, gastric erosions, and angiodysplasia were considered to be likely causes of occult gastrointestinal tract bleeding. MAIN OUTCOME MEASURES: Using colonoscopy results as the reference standard, sensitivity, specificity, and positive and negative predictive values for each of eight tests or pair of tests were compared with those of Hemoccult II. RESULTS: Of 81 patients, 10 had significant lower gastrointestinal tract lesions and six had significant upper gastrointestinal tract lesions. Hemoccult SENSA, Heme-Select, and FECA-EIA were shown to be more sensitive than Hemoccult II but slightly less specific. Paired tests showed less efficiency than Hemoccult II alone. CONCLUSIONS: We did not find an ideal test or pair of tests; however, Hemoccult SENSA exhibited higher sensitivity than Hemoccult II and many other tests. The sensitivity, specificity, and positive predictive values of many of the FOBTs were believed to be low. We recommend that physicians consider FOBTs only as adjuncts to history and physical examination findings in deciding how to proceed in diagnosing gastrointestinal tract disease.

Colonoscopy↗
PubMed1994

Bedtime dosing of glyburide and the treatment of type II diabetes mellitus.

Suppression of nocturnal hepatic glucose production is key in the treatment of noninsulin-dependent diabetes mellitus (NIDDM). In this article, the authors compare the effectiveness of dosing glyburide at bedtime versus in the morning on glycemic control in patients with NIDDM under suboptimal control. In a placebo-controlled, double-blind crossover trial, 32 patients with NIDDM with suboptimal control on chronic glyburide treatment fulfilling entry criteria were randomized to receive one of two regimens: (1) glyburide at bedtime and placebo in morning or (2) placebo at bedtime and glyburide in the morning. After 6 months of a regimen, patients crossed over to the other treatment and completed an additional 6-month period. After baseline assessment, fasting blood sugar, history, physical exam, and compliance assessments were performed monthly. HbA1c was measured bimonthly and Sustacal tolerance tests were performed at the end of each 6-month treatment period. During the initial 6-month comparison fasting, blood sugar concentration decreased 5% in bedtime ingesters and rose 10% in the morning patients. These changes were not statistically significant. HbA1c decreased significantly in the morning group but remained unchanged in the bedtime group. At the end of 12 months, nighttime dosing resulted in better home glucose monitoring values, fasting blood sugar results, and Sustacal tolerance profiles, but the differences were not statistically significant. No hypoglycemia was observed in the monitored data collected. Bedtime dosing of glyburide resulted in measurable improvement in fasting blood sugar and carbohydrate tolerance curves, but not to a degree justifying general recommendation of this technique in patients with NIDDM with secondary failure to oral agents.

Adolescent↗
PubMed1994

Development of a test of cognitive bias in medical decision making.

PURPOSE: To develop an inventory to measure the influence of cognitive biases on medical decisions. METHOD: The Inventory of Cognitive Biases in Medicine (ICBM) consists of 22 medical scenarios in which respondents choose between alternatives that represent bias-prone or statistically based decisions. In 1992 and 1993 the ICBM was administered to 102 medical students and residents and 318 physician faculty at the Wright State University School of Medicine. RESULTS: The statistically correct decision was made in fewer than half the ICBM scenarios for both groups (students and residents, 41%; faculty, 49%); and only the faculty scored better than chance. Acceptable reliability (KR 20 = .62 for the faculty administration) and item discrimination (mean = .49) were achieved. Further, the results suggest that the ICBM has both content and construct validity. CONCLUSION: The rather poor performances of the students and residents and the faculty on the ICBM suggest that cognitive biases constitute an important detraction from reliance on logical and statistical strategies. The ICBM shows promise for use as a tool in both instructional and research endeavors attempting to minimize and elucidate this phenomenon.

Cognition↗
PubMed1994

Relationship between critical thinking skills and success in preclinical courses.

PURPOSE: To examine the relationship between critical thinking skills as measured by the Watson-Glaser Critical Thinking Appraisal (WGCTA) and success during the first two years of medical school. METHOD: The WGCTA was administered to 92 students participating in orientation for the class of 1994. Total scores and subtest scores were calculated for each student. Scores from the Medical College Admission Test (MCAT) subtests, undergraduate grade-point averages (GPAs), gender, race-ethnicity, and other premedical data were obtained from admission files. Measures of student success in medical school included the final numerical scores of preclinical courses, preclinical GPA, United States Medical Licensing Examination (USMLE) Step 1 total score, course remediations, and alterations in schedules such as reduced loads or repeated years. Pearson correlation and the t-test were used in the analysis of data. RESULTS: WGCTA scores correlated best with MCAT scores for reading skils (r = .57) and quantitative skills (r = .40). Significant correlations were found between WGCTA scores and final scores for nearly all preclinical courses; however, the only correlations reaching .40 were for Behavioral Science 1 and Biometrics. Correlations between WGCTA scores and first- and second-year GPAs and scores on the USMLE Step 1 were between .33 and .36. The WGCTA scores for students who had extended time to meet course requirements or altered their curricula were significantly lower than those of students who neither took extended time nor changed their academic schedules. CONCLUSION: Critical thinking skills as measured by the WGCTA are moderately predictive of academic success during the preclinical years of medical education.

College Admission Test↗
PubMed1994

Diuretics potentiate angiotensin converting enzyme inhibitor-induced acute renal failure.

Previous studies suggest that angiotensin converting enzyme (ACE) inhibitors cause reversible acute renal failure (ARF) in patients with hypertension, congestive heart failure (CHF), and renal disease. These patients often receive diuretics concomitantly with ACE inhibitors. The purpose of this study was to examine whether ACE inhibitors alone produce ARF or whether they do so when used in combination with diuretics. The medical records of patients taking ACE inhibitors without or with diuretics were reviewed. Complete data from 74 patients were obtained and the data were analyzed. These 74 patients had a diagnosis of hypertension, CHF or diabetes mellitus. BUN and serum creatinine values before, during, and after discontinuation of ACE inhibitor therapy for a mean period of 8.7 months were collected. Seventy-four patients were divided into two groups: Group A (n = 41) patients who received ACE inhibitors alone; Group B (n = 33) patients who received a combination of an ACE inhibitor and a diuretic. ARF developed in 1 of 41 (2.4%) Group A patients compared to 11 of 33 (33%) Group B patients. This group difference was highly significant (P < .001). In Group A, mean serum creatinine before (1.24 +/- .34 mg/dl) was identical to that 1.23 +/- .33 mg/dl) after 8.7 months of ACE inhibitor therapy, whereas in Group B, post-mean serum creatinine (3.11 +/- 2.27 mg/dl) was significantly (P < .01) higher than pre-mean serum creatinine (1.65 +/- .85 mg/dl). CHF patients had a higher rate of ARF than patients with other diagnoses. Urinary electrolytes showed that 4 of 6 Group B patients had chloride concentration less than 20 mEq/l.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Kidney Injury↗
PubMed1993

A relationship between blood pressure control, hematocrit level, and renal function in treated essential hypertension.

The effect of rigid blood pressure control on renal function is an unsettled issue. This study describes a retrospective analysis on the relationships between blood pressure control, hematocrit levels, and renal function in 97 treated hypertensive patients. Data analysis was done on systolic and diastolic blood pressure, hematocrit levels, renal function assessed by serum urea nitrogen (SUN), serum creatinine (Scr), and hydrochlorothiazide (HCTZ) dose at entry and at four anniversary dates thereafter. The patients were divided into two groups: group I and group II on the basis of HCTZ dose. Group I received an average of 100 mg HCTZ daily, whereas group II received an average of 50 mg HCTZ daily. In group I, the decrement in both systolic and diastolic blood pressure over time was highly significant (P < .0001); however, no change in renal function was noted. In group II, systolic blood pressure decreased significantly (P < .01) from entry to year 1, then leveled off. In year 4, systolic blood pressure was not different from that of entry. Conversely, the difference between entry and year 4 diastolic blood pressure was highly significant (P < .0001). In group II, significant decreases were noted between entry and year 4, SUN (16.5 +/- 5.7 versus 14.9 +/- 4.1 mg/dL; P < .0012) and Scr (1.29 +/- .23 versus 1.24 +/- .19 mg/dL; P < .0192). Hematocrit showed diverse responses; in group I, hematocrit significantly increased from entry to year 4 (44.8 +/- 2.5 versus 47.2 +/- 3.9%; P < .01); whereas, in group II, hematocrit significantly decreased (47.7 +/- 3.8 versus 44.9 +/- 3.4%; P < .001).(ABSTRACT TRUNCATED AT 250 WORDS)

Black or African American↗
PubMed1993

Outpatient evaluation of obesity in adults and children: a review of the performance of internal medicine/pediatrics residents.

A chart audit of 115 adults and 113 children seen consecutively in an internal medicine/pediatrics residency was conducted to assess recognition of obesity and appropriateness of suggested therapy. Patients were categorized as obese, overweight, or normal based on body mass index. Forty-four percent of the children and 50% of the adults were classified as overweight or obese. Residents were more likely to document obesity in adults (53%) than in children (18%, p < 0.0001). Higher degree of obesity in adults increased resident documentation of the condition (p = 0.022), but presence of additional cardiovascular risk factors did not. When overweight or obesity was recognized, residents chose appropriate therapy. Enhanced education to improve recognition of obesity appears warranted.

Adolescent↗
PubMed1993

The relationship of academic measures in medical school to performance after graduation.

This study examined the relationship between academic variables in medical school and outcome measures in the first year of postgraduate training, using data from 947 graduates of Wright State University School of Medicine from 1980 through 1991. The medical school variables were preclinical grade-point averages (GPAs), clerkship GPAs, scores on the National Board of Medical Examiners (NBME) Part I examination, and NBME Part II scores. The outcome measures were NBME Part III scores and physician supervisors' ratings of clinical competence in residency. The medical school academic variables correlated between .46 and .71 with NBME Part III scores and between .20 and .30 with the physician supervisors' ratings. R2 values for NBME Part III scores and physician supervisors' ratings were .51 and .10. Chi-square analysis using factor-analysis-derived variables showed that top-quarter and bottom-quarter achievers in medical school were highly unlikely to change positions whether the graduate outcome measure was physician supervisors' ratings or NBME Part III scores.

Achievement↗
PubMed1993

Comparing clerkship sites in a community-based medical school by evaluating students' undergraduate and postgraduate performances.

BACKGROUND: Studies have generally found clinical training sites within the same clerkship to be comparable regarding students' performances--by using undergraduate measures in individual clerkships at medical schools with university hospitals. The present study examined performance comparability among sites within two clerkships in a community-based medical school and used both undergraduate and postgraduate measures. METHOD: The participants were the 349 graduates from the classes of 1988-1991 at Wright State University School of Medicine who took an internal medicine clerkship (332 of the graduates, in five principal combinations of sites) and a general surgery clerkship (349 at six sites). The undergraduate measures were final percent scores for the clerkships and subtest and total scores on the National Board of Medical Examiners (NBME) Part II examination. The postgraduate measures were supervisors' ratings from the first year of residency (210 graduates) and total score on the NBME Part III (212). Univariate analysis of variance and Tukey's multiple-range test were used for the comparisons. RESULTS: The only statistically significant difference among sites was for the medicine clerkship and involved only one undergraduate measure, the clerkship score (and the differences were slight, less than four percentage points). CONCLUSION: Virtually no differences in the students' performances on the undergraduate and postgraduate measures were found among sites for the two clerkships.

Clinical Clerkship↗