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Biomedical subjects

D F Ransohoff

Publications and source records attributed to D F Ransohoff.

At least 55 records · Page 3Linked to original sources

Outcome of acute cholecystitis in patients with diabetes mellitus.

Prophylactic cholecystectomy has been recommended in patients who have diabetes and silent gallstones because of the reports of increased mortality resulting from acute cholecystitis in such patients. To assess recent mortality rates, we reviewed the course of acute cholecystitis in patients hospitalized between 1960 and 1981 at one hospital. Death occurred in 3 of 46 patients with diabetes and in 7 of 263 patients without the disease (p = 0.55). The age-adjusted estimate of the relative risk for death was 2.2 (95% confidence interval, 0.5 to 9.4) for diabetic compared with nondiabetic patients. All 3 diabetic patients who died had been diagnosed as having diabetes within 5 years of death, and only one had been taking insulin. Patients who had elevated blood urea nitrogen levels (greater than 20 mg/dL) were found to have an increased mortality rate when compared with patients with normal levels (27% compared with 2%; p less than 0.001). Results were similar for the outcome of serious complications. These results suggest the need for reconsideration of the recommendation for prophylactic cholecystectomy in diabetic patients with silent gallstones.

Acute Disease↗

Ulcerative colitis and colonic cancer. Problems in assessing the diagnostic usefulness of mucosal dysplasia.

To assess the association of mucosal dysplasia and colonic cancer in patients with ulcerative colitis and to avoid bias in biopsy interpretation that may have affected results of previous studies, the authors examined coded histology slides from colectomy specimens of 22 patients who had ulcerative colitis and colonic cancer and 22 patients who had ulcerative colitis but no colonic cancer. As expected, it was found that dysplasia occurred contiguous to each cancer. However, at a distance from the cancer (i.e., in histology blocks not containing cancer), some dysplasia was found (low or high grade) in 16/22 cases (73 percent), and high grade dysplasia in 11/22 cases (50 percent). These results suggest that there may be somewhat weaker association than previously reported between colonic cancer and dysplasia at a distance from the colonic cancer. Further, these results suggest that, in studies of dysplasia, it is important to avoid bias in biopsy interpretation and to describe sampling methods.

Adolescent↗

Hepatitis B vaccination. Three decision strategies for the individual.

Three strategies regarding hepatitis B virus vaccination were compared by decision analysis: no vaccination, immediate vaccination, and vaccination after two years. The potential advantage of waiting two years is to learn whether serious side effects of the vaccine will become evident. For example, it was found that immediate hepatitis B vaccination of 100,000 surgical house officers with a 5 percent annual attack rate for five years would, compared with no vaccination, prevent 4,092 cases of icteric hepatitis, 335 cases of chronic active hepatitis, and 15 deaths from fulminant hepatitis. For a strategy of waiting two years, the number of cases prevented would decrease by about 40 percent. Persons in groups with an annual attack rate lower than 5 percent appear to benefit from vaccination. The known health risks of hepatitis B virus vaccination are low, and the hypothesized risks would have to be frequent to justify delay in vaccination. From an individual perspective, even persons at low risk of hepatitis B virus infection should seriously consider immediate vaccination.

Acquired Immunodeficiency Syndrome↗

A quantitative assessment of pre-dental antibiotic prophylaxis for patients with mitral-valve prolapse.

Because antibiotic prophylaxis for dental procedures in patients with mitral-valve prolapse (MVP) has been controversial, we performed a decision analysis to assess the costs and effects of the oral and parenteral penicillin regimens currently recommended for patients at high risk for bacterial endocarditis. The analysis suggests that there is a very small risk of post-dental endocarditis in MVP (4.1 cases per 10(6) procedures) which is outweighed by a greater risk of fatal reactions to parenteral penicillin (15 deaths per 10(6) courses). Parenteral penicillin prophylaxis therefore causes a net loss of life. For oral penicillin the risk of a fatal reaction is lower (0.9 deaths per 10(6) courses). However, oral penicillin prophylaxis appears to spare life only in older adults with MVP and at an extremely high cost: Over +1 million must be spent to spare one year of life. Personal preferences may still make antibiotic prophylaxis desirable for individual MVP patients. However, from a societal perspective, routine predental antibiotic prophylaxis for MVP is a very expensive preventive strategy.

Administration, Oral↗

Dysplasia in inflammatory bowel disease: standardized classification with provisional clinical applications.

Assessment of epithelial dysplasia in ulcerative colitis has been hindered by inconsistencies in and disagreements about nomenclature and interpretation. To resolve these issues, pathologists from ten institutions participated in three exchanges of multiple slides and, following each exchange, in discussions of the results. A classification system for the epithelial changes that occur in ulcerative colitis was developed, which should be applicable to other forms of inflammatory bowel disease as well. The classification makes use of standardized terminology, addresses specific problem areas, and offers practical solutions. The reproducibility of the system was studied by means of examinations of both inter- and intra-observer variations. The clinical implications of the findings were incorporated into suggestions for patient management. The basis of the classification is that the term "dysplasia" is reserved for epithelial changes that are unequivocally neoplastic and may therefore give rise directly to invasive carcinoma. Specimens are categorized as negative, indefinite, or positive for dysplasia. The negative category includes all inflammatory and regenerative lesions and indicates that only continued regular surveillance is required. The indefinite category is applied to epithelial changes that appear to exceed the limits of ordinary regeneration but are insufficient for an unequivocal diagnosis of dysplasia or are associated with other features that prevent such unequivocal diagnosis. Clinically, it indicates that early repeat biopsy is often required to assess the changes more accurately. The positive category is divided into two subcategories: 1) high-grade dysplasia, for which colectomy should be strongly considered after confirmation of the diagnosis, and 2) low-grade dysplasia, which also requires confirmation and early repeat biopsy or colectomy, depending on other findings.

Biopsy↗

Prophylactic cholecystectomy or expectant management for silent gallstones. A decision analysis to assess survival.

Decision analysis was done to compare the consequences of prophylactic cholecystectomy with expectant management for silent gallstone disease. Probability values were derived from a study of the natural history of silent gallstone disease, published cholecystectomy mortality rates, and life tables. The two strategies were compared by calculating cumulative numbers of person-years lost for hypothetical cohorts of men and women. Prophylactic cholecystectomy slightly decreases survival. A 30-year-old man choosing prophylactic cholecystectomy instead of expectant management would lose, on average, 4 days of life; a 50-year-old man would lose 18 days. Consideration of monetary costs and discounting further disfavors prophylactic cholecystectomy. Sensitivity analysis shows that differences between the two strategies remain small over a broad range of probability values, both for men and women.

Adult↗

Diagnostic workup bias in the evaluation of a test. Serum ferritin and hereditary hemochromatosis.

Two studies report markedly divergent results about the usefulness of serum ferritin in diagnosing iron overload in relatives of patients with hereditary hemochromatosis. One study found the sensitivity of elevated serum ferritin to be 0%; another study found a sensitivity of 100%. Although different genetic abnormalities in iron or ferritin metabolism may explain the different results, our examination of these studies suggests that diagnostic workup bias also may explain the difference. In the study reporting a sensitivity of 100%, relatives with normal serum tests may have been excluded from consideration for liver biopsy, thus preventing detection of iron overload. The controversy may provide an empirical illustration of diagnostic workup bias.

Adolescent↗

Terminal hepatic failure following a small dose of sulfamethoxazole-trimethoprim.

Fatal hepatotoxicity is a known complication of sulfamethoxazole and sulfamethoxazole-trimethoprim. We report a case of a man previously exposed to sulfamethoxazole-trimethoprim who died of liver failure following subsequent ingestion of only two tablets of the drug (160 mg trimethoprim and 800 mg sulfamethoxazole). This case indicates the danger to a susceptible patient of even small (e.g., "rechallenge") doses of sulfamethoxazole.

Aged↗

Problems of spectrum and bias in evaluating the efficacy of diagnostic tests.

To determine why many diagnostic tests have proved to be valueless after optimistic introduction into medical practice, we reviewed a series of investigations and identified two major problems that can cause erroneous statistical results for the "sensitivity" and "specificity" indexes of diagnostic efficacy. Unless an appropriately broad spectrum is chosen for the diseased and nondiseased patients who comprise the study population, the diagnostic test may receive falsely high values for its "rule-in" and "rule-out" performances. Unless the interpretation of the test and the establishment of the true diagnosis are done independently, bias may falsely elevate the test's efficacy. Avoidance of these problems might have prevented the early optimism and subsequent disillusionment with the diagnostic value of two selected examples: the carcinoembryonic antigen and nitro-blue tetrazolium tests.

Bacterial Infections↗

Needlestick injuries among resident physicians.

OBJECTIVE: To assess the frequency and causes of needlestick injuries in medical and surgical housestaff. DESIGN: A retrospective survey. SETTING: Urban university teaching hospital. PARTICIPANTS: 386 housestaff; 221 responded. INTERVENTION: Survey questionnaire. MAIN RESULTS: 1) Frequency of needlestick: Of 221 respondents, 57 (26%) reported never having had a needlestick, while 164 (74%) reported at least one needlestick injury with a suture or hollow-bore needle. The average frequencies were 0.63 per resident-year among 149 non-surgical residents and 3.8 per resident-year among 72 surgical residents. Among residents in internal medicine, 12 of 78 needlestick injuries (15%) sustained were from patients documented to be HIV-positive. 2) Causes of needlestick: The causes of injury were assessed in detail in a sample of the 157 most recent needlestick injuries. Suturing was the cause in 35 of 61 (57%) surgical residents, while recapping needles was the cause in 36 of 96 (38%) non-surgical residents. Inexperience was not the cause of injury; in 94% of cases the residents felt comfortable performing the procedure, and in 74% of cases the residents had performed the procedure more than 50 times before. 3) Reporting of injury: Only 30 (19%) of 157 injuries were reported to the personnel health service, thus compromising documentation for potential workmen's compensation. CONCLUSIONS: Needlestick injuries are common among medical and surgical housestaff. Efforts should be made to prevent needlestick injuries and to report those that occur.

Academic Medical Centers↗