Search PubMed⌕ Search

Biomedical subjects

K Brown

Publications and source records attributed to K Brown.

At least 523 records · Page 29Linked to original sources
PubMedDate not supplied

Debias the environment instead of the judge: an alternative approach to reducing error in diagnostic (and other) judgment.

Questions about how to improve human judgment and reasoning are of theoretical and practical interest, notwithstanding the continuing controversy over whether people are "rational". Improving judgment may involve modifying people's processes to fit their environments better, or vice versa. We illustrate the latter approach in a study of diagnostic reasoning in which subjects learned to distinguish two fictitious diseases. Prior findings suggest that people may judge the likelihood of a diagnostic category on the presence or absence of features that are typical of, rather than diagnostic of, the category. We varied the structure of the information provided to subjects without attempting to modify their judgmental processes. In an "independent" format, subjects learned about each disease separately; in a "contrastive" format, information about the two diseases was juxtaposed to highlight distinctive features. Subjects in the two conditions formed different disease concepts. Diagnoses following contrastive training were much closer to the statistically prescribed judgments based on likelihood ratios. Interventions that modify the environment may provide an alternative approach where it is difficult to modify people's processes. Effective design of such interventions is one motivation for directing research toward understanding how task characteristics affect the use of and the outcomes of judgment and reasoning processes.

Adult↗
PubMedDate not supplied

Outcome of domiciliary care after inpatient alcoholism treatment in male veterans.

Current literature is ambiguous as to the impact of extended treatment services following hospitalization on outcomes such as abstinence. This study compares the outcomes of care for 276 veterans who completed inpatient treatment for alcoholism, 77 of whom (28%) were transferred to a domiciliary and the remainder of whom were discharged directly into the community. The domiciliary group of alcoholics differed at baseline from alcoholics discharged to the community with significantly higher psychiatric comorbidity and lower social support, both negative predictors of treatment outcome. A multiple logistic regression model was used to assess the impact of domiciliary placement on: (a) 3-month abstinence comparing the time after discharge from either the domiciliary or the inpatient treatment unit and (b) 12-month abstinence after discharge from the inpatient treatment unit, including patients placed in the domiciliary. Controlling for baseline differences, domiciliary placement was found to be a significant predictor of abstinence (odds ratios of 2.3 for 3-month and 2.5 for 12-month abstinence, p < or = 0.01). In a survival analysis, domiciliary placement was also a significant predictor of time to readmission after treatment discharge with a risk ratio of 0.2 (p < 0.01). Our results demonstrate a protective effect of domiciliary after-care for high risk alcoholics after inpatient treatment.

Adult↗
PubMedDate not supplied

Helping others: a response to HIV disease.

Previous research supports that helping behaviors can be as beneficial to the person providing the help as to the recipient. Ten individuals infected with HIV describe how helping others became an important strategy in helping them live with their diagnosis of HIV/AIDS. A grounded theory study was done to identify and describe psychosocial responses to being infected with HIV. Audiotaped interviews were analyzed using grounded theory methodologies. The core category that emerged from the data was fighting to survive. Taking care and restructuring one's life were the supporting concepts. Processes involved in taking care were everyday work and illness work. Helping others was one strategy of everyday work the participants found to be helpful in the fight to survive. The benefits of helping are described and the various ways of helping are presented in this article.

Adaptation, Psychological↗
PubMedDate not supplied

Cystic glucagonoma: A rare variant of an uncommon neuroendocrine pancreas tumor.

Glucagon-producing neuroendocrine tumors typically present with a characteristic constellation of symptoms including necrolytic migratory erythema, non-insulin-dependent diabetes, weight loss, anemia, glossitis, and an increased thrombotic tendency. Most glucagonomas are solid and arise in the body or tail of the pancreas. We report two cases of cystic glucagonoma, one found incidentally in an asymptomatic patient and one in a patient with weight loss and diabetes but no rash. In the first patient, distal pancreatectomy and splenectomy were curative, whereas the second patient continued to exhibit elevated serum glucagon levels and symptoms of glucose intolerance in the absence of demonstrable metastases. Cystic glucagonoma is a unique variant of classic glucagonoma and should be considered in the differential diagnosis of cystic pancreatic neoplasms.

Adult↗
PubMedDate not supplied

Carcinogen-specific mutation and amplification of Ha-ras during mouse skin carcinogenesis.

Cellular proto-oncogenes can be activated by both point mutations and chromosomal translocations, suggesting that there may be a direct link between exposure to agents which damage DNA and genetic change leading to malignancy. Several groups have therefore analysed mutations found in cellular oncogenes of tumours induced by particular physical or chemical carcinogens. Here, we have analysed the molecular changes at different stages of carcinogenesis in mouse skin tumours induced by initiating and promoting agents. Over 90% of tumours, including premalignant papillomas, initiated with dimethylbenzanthracene (DMBA) have a specific A----T transversion at the second nucleotide of codon 61 of the Harvey-ras (Ha-ras) gene. The frequency of this mutation was dependent on the initiating agent used, but not on the promoter, suggesting that the mutation occurs at the time of initiation. The mutation was heterozygous in most papillomas tested, but was homozygous or amplified in some carcinomas. The development of further chromosomal changes at the c-Ha-ras gene locus is therefore a common feature of tumour progression.

9,10-Dimethyl-1,2-benzanthracene↗
PubMedDate not supplied

Postnatal care in low-income urban African American women: relationship to level of prenatal care sought.

OBJECTIVE: This study examined the relationship between level of prenatal care utilization and postnatal patterns of health care behavior among high-risk minority women. The primary hypothesis was that prenatal care utilization predicts subsequent levels of both the maternal and child health services used in the postnatal period. METHODS: The study population consisted of 297 low-income African American women who were recruited at delivery at an urban tertiary medical center in the Mid-Atlantic region. They were followed monthly for 1 year using telephone interviews to determine their use of maternal and child health services. Four levels of prenatal care were identified retrospectively based on reviews of health records and screening interviews using the Kessner Index. Data regarding pregnancy outcomes, maternal postnatal visits, and well-child and acute care child visits were collected. RESULTS: Women who sought inadequate or no prenatal care had greater infant morbidity and mortality in the postnatal period and significantly lower levels of attendance at maternal postnatal visits, well-child visits, immunization completions, and acute care visits. CONCLUSION: This study confirms that the level of prenatal care is indicative of the level of postnatal care women seek for themselves and their children in the first year after delivery.

Adolescent↗
PubMedDate not supplied

Ethics and rehabilitation of the patient with severe burns.

In the case we present, a physician's order for the treatment of a patient with severe burns unfolds into an ethical dilemma for an occupational therapist. Several conflicting thoughts-in terms of the appropriateness and plan for treatment, while trying to maintain the patient's best interest as the central focus-come to mind. We examine the therapist's ethical responsibilities in light of considerations of futility, nonmaleficence, financial costs, and team relations. Several options for responding to the case are suggested.

Adult↗
PubMedDate not supplied

MR imaging of aneurysm of an aberrant right subclavian artery.

Magnetic resonance (MR) imaging was performed for evaluation of a right paramediastinal mass in an asymptomatic 84-year-old woman. An aneurysm of an aberrant right subclavian artery was diagnosed. This rare complication of a common congenital anomaly and the use of MR in evaluation is discussed.

Aged↗
PubMedDate not supplied

MR imaging of the thorax: a comparison of axial, coronal, and sagittal imaging planes.

We performed direct multisection coronal and sagittal magnetic resonance (MR) images in addition to axial images to determine the value and limitations of coronal and sagittal planes compared with axial planes. Ninety-four MR examinations of the thorax were performed with a 0.3 T permanent magnet system (Fonar) by spin echo technique. The MR axial images were found superior to coronal in demonstrating prevascular adenopathy (one case), pretracheal nodes (nine cases), left paraaortic nodes (three cases), subcarinal nodes (three cases), and small pleural effusions (three cases). The coronal or sagittal planes were better to determine relationship of a mass at the lung apex (five cases) or an abnormality at the lung base (five cases). The anteroposterior displacement or compromise of great vessels and bronchi was best displayed on the axial plane whereas craniocaudal displacement of above structures was best seen on the coronal plane. The axial images were found most informative and we suggest that they be performed routinely. Coronal or sagittal planes may be added in selected cases.

Carcinoma, Bronchogenic↗
PubMedDate not supplied

Laboratory diagnosis of sexually transmitted diseases in facilities within the United States. Results of a national survey.

BACKGROUND AND OBJECTIVES: The diagnosis of many sexually transmitted diseases (STD) requires laboratory testing. The authors assessed the effects of the introduction of new tests and regulations on STD testing. STUDY DESIGN: A questionnaire survey was mailed to a random sample of facilities listed in the STD Referral Database inquiring about tests offered, changes in testing, and reasons for changes. RESULTS: Responses from 405 facilities were analyzed. Most responding facilities collected specimens for nontreponemal tests for syphilis (352 of 405 [86.9%]). Since each facility's information was last updated, the number reporting testing for Chlamydia trachomatis rose from 160 of 405 (39.5%) to 288 of 405 (71.1%), but testing for gonorrhea and chancroid decreased (365 of 405 [90.1%] to 328 of 405 [81%], and 182 of 405 [44.9%] to 32 of 405 [7.9%], respectively). Of 364 responses to a question on changes in tests performed in the last 2 years, 249 (68.4%) reported no change, 81 (22.3%) reported an increase, and 37 (10.2%) reported a decrease. The most frequently added tests were nonculture tests for C. trachomatis (34 of 81 [42%]) and the most frequent reason for adding tests was targeted funding (25 of 81 [30.9%]). The most frequently discontinued tests were cultures and gram stains for gonorrhea (15 of 37 [40.5%]) and other in-house tests (9 of 37 [24.3%]). Most facilities that discontinued testing cited the Clinical Laboratory Improvement Act as the reason (34 of 37 [91.9%]; 95% confidence interval = 78.1%, 98.3%). CONCLUSIONS: The number of facilities testing for C. trachomatis has increased with funding and with the availability of nonculture tests, but the number of those testing for chancroid and gonorrhea has decreased. Implementation of the Clinical Laboratory Improvement Act may be associated with a decrease in the number of facilities performing tests for STD.

Clinical Laboratory Techniques↗
PubMedDate not supplied

Preoperative Ilizarov frame construction for correction of ankle and foot deformities.

The Ilizarov method is being used increasingly to correct many orthopedic deformities. The frames required for ankle and foot deformity correction are among the most difficult to construct owing to the complexity of the deformities which must be corrected. A technique using a rubberized material (Pedilen) to create an exact replica of a preoperative ankle and foot deformity is described. This exact model, both in size and shape, may then be used on a workbench to preconstruct an Ilizarov frame that resembles the patient's deformity exactly in three dimensions with respect to size and shape. This allows thoughtful frame construction before operation reducing operating time and minimizing frustrations that may arise with complex deformities.

Adolescent↗
PubMedDate not supplied

Neutron irradiation of human melanoma cells.

The biological characteristics and in vitro radiosensitivity of melanoma cells to thermal neutrons were investigated as a guide to the effectiveness of boron neutron capture therapy. Plateau phase cultures of three human malignant melanoma-established cell lines were examined for cell density at confluence, doubling time, cell cycle parameters, chromosome constitution, and melanin content. Cell survival dose-response curves, for cells preincubated in the presence or absence of p-boronophenylalanine. HCl (10B1-BPA), were measured over the dose range 0.6-8.0 Gy (N + gamma). The neutron fluence rate was 2.6 x 10(9) n/cm2/s and the total dose rate 3.7 Gy/h (31% gamma). Considerable differences were observed in the morphology and cellular properties of the cell lines. Two cell lines (96E and 96L) were amelanotic, and one was melanotic (418). An enhanced killing for neutron irradiation was found only for the melanotic cells after 20 h preincubation with 10 micrograms/ml 10B1-BPA. In view of the doubling times of the cell lines of about 23 h (96E and 96L) or of 36 h (418), it seems likely that an increased boron uptake, and hence increased radiosensitivity, might result if the preincubation period with 10B1-BPA is extended to several hours longer than the respective cell cycle times.

Boron Compounds↗
PubMedDate not supplied

Pitfalls in the diagnosis of thoracic aortic dissection at CT angiography.

Two hundred seventy-five computed tomographic (CT) angiograms of the thoracic aorta were obtained over a period of approximately 4 years in patients with suspected or known aortic dissection. In all cases, unenhanced images were initially obtained, followed by contrast material-enhanced images. A variety of pitfalls were encountered that mimicked aortic dissection. These pitfalls were attributable to technical factors (eg, improper timing of contrast material administration relative to image acquisition); streak artifacts generated by high-attenuation material, high-contrast interfaces, or cardiac motion; periaortic structures (eg, aortic arch branches, mediastinal veins, pericardial recess, thymus, atelectasis, pleural thickening or effusion adjacent to the aorta); aortic wall motion and normal aortic sinuses; aortic variations such as congenital ductus diverticulum and acquired aortic aneurysm with thrombus; and penetrating atherosclerotic ulcer. Although several of these pitfalls are easy to recognize and therefore unlikely to present a diagnostic problem, others are potentially confusing. Familiarity with these common pitfalls, coupled with a knowledge of normal intrathoracic anatomy, will facilitate recognition of true aortic dissection and help avoid misdiagnosis at thoracic aortic CT angiography.

Aortic Dissection↗