Biomedical subjects
R A Wright
Publications and source records attributed to R A Wright.
Interactive effects of difficulty and instrumentality of avoidant behavior on cardiovascular reactivity.
College-aged subjects performed 35 trials of an easy or difficult digit-recognition task. Half were told that a good performance would ensure a high chance of avoiding a blast of noise, and half were told that a good performance would ensure a low chance of avoiding the noise. Results indicated that heart rate and systolic blood pressure reactivity were higher in the difficult condition than in the easy condition only when the probability of avoiding the noise (given success) was high. When the probability of avoiding the noise (given success) was low, heart rate and systolic responsivity were low regardless of task difficulty. It also was found that (1) performance quality was poorer overall among difficult subjects than among easy subjects, and (2) that the difference in performance quality between the easy and difficult groups was somewhat (not significantly) greater in the low-probability conditions than in the high-probability conditions. Major findings are considered in terms of Obrist's reasoning regarding the psychophysiological consequences of active coping and a motivational model by Brehm, which specifies conditions under which individuals will be more and less task engaged.
Obstructive jaundice secondary to primary biliary involvement with Hodgkin's disease.
A 41-yr-old man presented with jaundice, night sweats, and weight loss. The patient had been on phenytoin for seizure disorder. The drug was discontinued, and a diminution of bilirubin and transaminases occurred over several weeks. Percutaneous liver biopsy revaled cholestasis at the time of maximal hyperbilirubinemia. Recurrent jaundice ensued several weeks later, and an ERCP revealed a common bile duct lesion. Laparotomy revealed Hodgkin's disease involving the common bile duct and periportal node. This cause represents the first report of extrahepatic biliary obstruction from Hodgkin's disease.
Cryptococcal olecranon bursitis in cirrhosis.
A 47-year-old man with cirrhosis developed a case of previously unreported olecranon bursitis due to Cryptococcus neoformans. Most patients with disseminated cryptococcosis have deficiencies in cell mediated immunity. Cirrhosis may be an independent risk factor because of impaired chemotaxis and phagocytosis.
The evaluation and treatment of men with asymptomatic prostate nodules in primary care: a decision analysis.
BACKGROUND: Whether to perform periodic rectal examinations in asymptomatic men as a screening test for prostatic cancer remains controversial. A randomized clinical trial that tests the efficacy of further evaluation and treatment of men who have been found to have asymptomatic prostate nodules may never be carried out. Decision analysis was therefore used to further investigate this clinical issue. METHODS: A decision tree was developed to model the decision of whether to biopsy an asymptomatic prostate nodule found by digital rectal examination in a 65-year-old man by his primary care physician. Test operating characteristics, probabilities of disease at different stages, probabilities of side effects from various treatments, and average life expectancies were obtained from the medical literature. Utilities for the various possible health outcome states were obtained from ratings by two experienced primary care physicians using the Kaplan-Anderson Quality of Well-Being Scale. These were used to adjust the quality-of-life expectancies for each outcome state. Multiple sensitivity analyses were performed to assess the robustness of the conclusions. RESULTS: Disregarding patient utilities, the average survival benefit of evaluation and treatment is 1.1 months. When quality-of-life adjustments are included in the analysis, evaluation and treatment results in an average loss of 3.5 quality-adjusted months of life. Factors that shift the decision toward evaluation and treatment include a positive predictive value of a prostate nodule for cancer of 49% or greater, specificity of prostate biopsy of 98.3% or greater, and the availability of much more effective treatment for stage D cancers. Factors that do not substantially affect the decision are cancer-free life expectancy, the percentage of cancers that are stage B at time of discovery, the sensitivity of prostate biopsy, and more effective treatment for stage C cancer, assuming the same rate of adverse consequences from treatment. CONCLUSIONS: The evaluation and treatment of prostatic nodules found by digital rectal examination in asymptomatic men in the primary care setting does not lead to significant improvement in life expectancy and adversely affects quality of life. Digital rectal examination should not be performed by primary care physicians as a screening test for prostate cancer.
Clinical judgment and bioethics: the decision making link.
The literature on bioethics is diverse and confusing in its treatment of appropriate components for decision making. As a result, the literature on teaching bioethics is also confusing, even contradictory, in presenting an 'appropriate' framework within which learners may come to understand the nature and process of bioethics. The article sets out five decision components which are seen as common to all decision making. These components are then shown to have a significant influence both on bioethics decision making and on bioethics teaching. They are also shown to play a role in breaking down the separatism evidenced in contemporary bioethics literature aimed at individual professions.
Outpatient liver biopsy: one man's experience.
As an academically based gastroenterologist, I performed 94 outpatient liver biopsies over a 42-month period, using the standard suction technique. Differential blood count and vital signs were monitored, with no statistically significant postbiopsy changes noted in the group at large. One patient required admission to the hospital for bleeding, and six patients required intramuscular analgesics for pain at the biopsy site. Four patients had bradycardia, and one of them required atropine for bradycardia and hypotension. Outpatient liver biopsy is a safe procedure with low morbidity and complication rate. It would appear that prolonged monitoring is not necessary.
Gastric emptying in achalasia.
Some investigators have postulated that patients with primary achalasia have a generalized upper gastrointestinal motility disorder. To evaluate gastric emptying in patients with primary achalasia, four patients were studied prospectively after successful brusque dilation. Gastric emptying of liquids and solids was normal in all patients. There is no defect in gastric emptying in patients with primary achalasia.
Three polymorphisms at the D17S29 locus.
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Acid-induced esophagobronchial-cardiac reflexes in humans.
Esophagobronchial reflexes have been demonstrated in both the cat and dog models. In order to determine if these reflexes are present in humans and if they are vagally mediated, a prospective sequential study was initiated. One hundred thirty-six individuals referred for esophageal manometric measurements were studied. Measurements of airway flow, arterial oxygen saturation, and pulse rate were performed before and after intraesophageal infusion of sterile water, normal saline solution, and 0.1 N hydrochloric acid. Highly significant reductions in heart rate, airway flow, and arterial oxygen saturation were noted after infusion of normal saline and 0.1 N hydrochloric acid compared with baseline water infusion (P less than 0.001). Graded responses were noted with heart rate: the more acidic the solution infused, the larger the decrement of heart rate. Atropine abolished postsaline/acid decrements of airway flow, arterial oxygen saturation, and heart rate. It is concluded that acid-induced, vagally mediated esophagobronchial reflexes are present in humans.
Task demand and cardiovascular response magnitude: further evidence of the mediating role of success importance.
The interactive effects of success importance and task demand upon cardiovascular reactivity were investigated in 2 experiments. In Experiment 1, Ss learned that success on an easy or difficult memory task would allow them to avoid a mild or severe noise. As expected, pretask and task elevations in heart rate and systolic blood pressure increased with difficulty only when the noise was to be severe. In Experiment 2, Ss listened to a victim, attending either to how she must feel or to technical features of the presentation. Then they were given the chance to earn a donation by succeeding on an easy or difficult memory task. Pretask cardiovascular data accorded with predictions predicated on the assumption that the need to help would be greater among victim perspective Ss. For them, systolic elevations increased with difficulty, whereas for technical perspective Ss systolic elevations were low regardless of task demand.
Peripheral parenteral nutrition is no better than enteral nutrition in acute exacerbation of Crohn's disease: a prospective trial.
The use of parenteral nutrition in patients with exacerbation of regional enteritis is controversial, the clinical dictum being bowel rest and nutritional repletion. In order to address this issue, on the short-term at least, a prospective randomized trial compared peripheral parenteral alimentation and elemental feedings for 2 weeks in patients hospitalized with regional enterities. Both groups had significant objective clinical improvement on their respective nutritional supplementation regimens pre- versus posttherapy as assessed by the Crohn's Disease Activity Index (CDAI) (p less than 0.05). However, there was no significant difference in improvement between parenteral versus enteral groups as assessed by the CDAI. Changes in nutritional assessment parameters, including retinol binding protein, nitrogen balance, total lymphocyte count, and transferrin, were related to the quantity of calories consumed rather than the mode of delivery. A positive nitrogen balance was obtained in all patients despite weight loss in the majority. The route of nutrient delivery in acute exacerbation of regional enteritis does not appear to have an impact on the short-term outcome.
Randomized, controlled trial of a 10-day course of amifloxacin versus trimethoprim-sulfamethoxazole in the treatment of acute, uncomplicated urinary tract infection. Amifloxacin Multi-Center Trial Group.
We conducted a randomized controlled trial of orally administered amifloxacin versus trimethoprimsulfamethoxazole (TMP-SMX) as treatments of acute uncomplicated urinary tract infection in women. Amifloxacin at a dosage of 200 mg twice a day appeared as safe and effective as TMP-SMX, but amifloxacin at 400 mg twice a day tended to cause adverse events more frequently than did TMP-SMX.
Pancreatitis coexisting with a large cystadenoma of the pancreas.
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Difficulty and instrumentality of imminent behavior as determinants of cardiovascular response and self-reported energy.
College-aged male subjects were presented with an easy or moderately difficult memorization task and were told that they could earn either a very low or a very high chance of obtaining a modest prize if they did well. Cardiovascular (heart rate, systolic blood pressure, diastolic blood pressure) and subjective measures were taken during an interval immediately preceding the task performance period. Results indicated greater systolic blood pressure and self-perceived energy in the moderately difficult condition than in the easy condition only when the probability of attaining the prize (if subjects did well) was high. When the probability of goal attainment (given success) was low, systolic responses and self-reported energy levels were minimal in both task conditions. Predictions regarding the impact of energy levels upon goal attractiveness ratings were not supported, possibly for methodological reasons.
Primary melanoma of the common bile duct.
We have described what we believe is the first reported case of primary melanoma of the common bile duct. The presenting sign was obstructive jaundice. An extensive evaluation for another primary source was unrevealing. Despite a Whipple procedure, the patient's condition deteriorated rapidly.
Diagnostic criteria and efficient use of outpatient cultures.
The authors conducted an eight-year longitudinal study to evaluate the effect of diagnostic criteria on efficient use of outpatient cultures. Efficiency was determined by monitoring alterations in culture use, yield (percent positive), and charges for four common ambulatory diseases: Group A streptoccocal pharyngitis; gonococcal urethritis and cervicitis; bacterial cystourethritis; and acute enterocolitis.The study demonstrated that the use of diagnostic criteria resulted in more efficient use of laboratory tests as reflected in the immediate and sustained decrease in culture use and associated charges, an increase in yield (percent positive), and a corresponding decrease in charge per test.
Monotherapy of mild hypertension with nifedipine.
The effectiveness of nifedipine as first-line monotherapy for mild diastolic hypertension (range: 95 to 105 mm Hg) was tested in this placebo-controlled, double-blind, randomized trial. Fifty-six patients were enrolled and, after titration of the placebo or active drug, they were followed for 12 weeks. Significant declines in the sitting systolic and diastolic pressures of -19 +/- 4 mm Hg (standard error) and -13 +/- 2 mm Hg, respectively, were observed during this follow-up period. Overall, 75 percent of patients receiving active drug had diastolic pressures less than or equal to 90 mm Hg at the last treatment visit. Heart rate was not significantly changed in the sitting position during the treatment period, and the majority of patients (75 percent) showed a response to nifedipine doses of 10 or 20 mg orally three times daily in the capsule form. The levels of the systolic and diastolic pressures at entry were not predictive of the dose of nifedipine required for effective blood pressure control.