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Biomedical subjects

D Carr

Publications and source records attributed to D Carr.

At least 55 records · Page 3Linked to original sources
PubMed1997

The fulfillment of career dreams at midlife: does it matter for women's mental health?

This paper examines whether a woman's mental health at midlife is affected by the degree to which her earlier career aspirations have been fulfilled. Two dimensions of mental health are considered: depression and purpose in life. Based on data for 3,499 female respondents to the Wisconsin Longitudinal Study (WLS), the results indicate that women who have fallen short of their earlier career goals suffer from lower levels of purpose in life and higher levels of depression, even after controlling for social background, human capital, family, and health characteristics. For purpose in life, the harmful effects of falling short of one's goal attenuate considerably when current family characteristics are controlled. For depression, the harmful effects of falling short of one's goal decline considerably once health characteristics are considered. Although women who aspired to be housewives evidenced lower levels of purpose in life at midlife than women with work aspirations, this difference was not statistically significant once human capital characteristics were controlled. Women who, at age 35, "did not know" what they hoped to do in the future had significantly lower levels of purpose in life in their 50s, even after controlling for social background, human capital, family, and health characteristics.

Career Mobility↗
PubMed1996

Mechanisms of drug-induced lupus. II. T cells overexpressing lymphocyte function-associated antigen 1 become autoreactive and cause a lupuslike disease in syngeneic mice.

Current theories propose that systemic lupus erythematosus develops when genetically predisposed individuals are exposed to certain environmental agents, although how these agents trigger lupus is uncertain. Some of these agents, such as procainamide, hydralazine, and UV-light inhibit T cell DNA methylation, increase lymphocyte function-associated antigen 1 (LFA-1) (CD11a/CD18) expression, and induce autoreactivity in vitro, and adoptive transfer of T cells that are made autoreactive by this mechanism causes a lupuslike disease. The mechanism by which these cells cause autoimmunity is unknown. In this report, we present evidence that LFA-1 overexpression is sufficient to induce autoimmunity. LFA-1 overexpression was induced on cloned murine Th2 cells by transfection, resulting in autoreactivity. Adoptive transfer of the transfected, autoreactive cells into syngeneic recipients caused a lupuslike disease with anti-DNA antibodies, an immune complex glomerulonephritis and pulmonary alveolitis, similar to that caused by cells treated with procainamide. These results indicate that agents or events which modify T cell DNA methylation may induce autoimmunity by causing T cell LFA-1 overexpression. Since T cells from patients with active lupus have hypomethylated DNA and overexpressed LFA-1, this mechanism could be important in the development of human autoimmunity.

Animals↗
PubMed1996

Prostate cancer: current and evolving strategies.

The staging, screening and diagnosis, and treatment of prostate cancer are discussed. Prostate cancer kills about 40,000 men in the United States each year. Signs and symptoms range from dysuria to features of advanced metastatic disease. The American Urological System of staging prostate cancer designates four stages, A through D. The tumor is graded histologically with the Gleason scale. Methods used in the screening and diagnosis of prostate cancer include digital rectal examination, the prostate-specific antigen (PSA) assay, biopsy, transrectal ultrasonography, and determination of PSA density, velocity, and age specificity. The value of screening and treatment remains controversial because tumors are generally slow-growing and conclusive data showing an effect on survival time are lacking. Treatment methods consist of prostatectomy, radiation therapy, and hormonal drug therapy or bilateral orchiectomy. The choice is influenced primarily by the stage of the disease but also by the patient's age, physical condition, and response to prior therapy. Patients with stage A or B disease are considered for prostatectomy or radiation therapy. The primary treatment for stage C disease is radiation therapy. For stage D, the main approaches are watchful waiting and bilateral orchiectomy or hormonal drug therapy to reduce androgenic stimulation of prostate tissue. Long-term survival rates are high for stages A and B and considerably lower for stages C and D. Prostate cancer responds to estrogens, but adverse effects are frequent and potentially severe. Luteinizing hormone-releasing hormone agonists (leuprolide and goserelin) are as effective as estrogens but have less toxicity; a disadvantage of these agents is an initial flaring of the disease. Other hormonal agents used include antiandrogens-progestins, flutamide, and bicalutamide. Secondary hormonal treatments (aminoglutethimide and ketoconazole) are less effective than initial hormonal therapy. Antineoplastic agents have little or no effectiveness in prostate cancer. Although the value of screening for and treating prostate cancer continues to be debated, many experts recommend annual screening for all men over 50. Research to identify more effective drugs for treating advanced disease continues.

Androgen Antagonists↗
PubMed1996

Tolerance to subchronic, high-dose ingestion of erythritol in human volunteers.

Erythritol is a sugar alcohol (polyol) which is absorbed from the small intestine in substantial amounts, not metabolized in the human body, and therefore excreted in the urine. Erythritol holds promise as a low-calorie sugar substitute. Human tolerance to repeated oral doses of erythritol was examined in a double-blind, two-way crossover study in 12 healthy, male volunteers. The participants consumed erythritol and, for comparison, sucrose for a duration of 7 days each. The daily dose of the test compounds ingested was 0.3 g/kg on Day 1, 0.6 g/kg on Day 2, and 1.0 g/kg on subsequent days. The daily dose was consumed under supervision in five portions, i.e., with the three main meals, a midmorning snack, and during the afternoon. The test compounds were incorporated into yoghurt, cookies, soft drinks, and chocolate. On each treatment day, body weight and blood pressure were measured and the participants were interviewed about side effects and their perception of stool and urine production. During the last 96 hr of each treatment period, urine was collected at 3-hr intervals during the day and for a 9-hr interval overnight for analysis of erythritol and different urinary parameters. On Days 3 to 7 of each treatment period, the participants were institutionalized. Body weights and blood pressure remained stable during the entire study. Signs of gastrointestinal intolerance were not seen and stool frequency and appearance were not different between the two treatments. The intake of liquids, which were provided ad libitum, was generally rather high (32.8 g/kg body wt/day on average) but not different between erythritol and sucrose consumption. Urine output also was high during both treatment periods. About 78% of ingested erythritol was excreted in the urine which led to a higher urinary osmolality but did not influence the 24-hr output of creatinine, citrate, urea, or electrolytes (Na+, K+, Cl-, Pi). The excretion of calcium was slightly higher during the erythritol test period but in absolute terms this increase was small. The urinary excretions of albumin, beta 2-microglobulin, and N-acetyl-glucosaminidase were slightly elevated during the erythritol test period but they were still well within the physiological range. None of the observed urinary changes became more pronounced with increasing duration of the erythritol treatment. In conclusion, the results of the present study demonstrate that the repeated ingestion of erythritol at daily doses of 1 g/kg body wt was well tolerated by humans.

Administration, Oral↗
PubMed1996

Can the computerized physical examination differentiate normal subjects from abnormal subjects with benign mechanical low back pain?

Inconsistencies among physicians in the evaluation of benign low back conditions make standardization desirable. A computerized physical examination device was used to evaluate low back pain patients and compare their results with a normative database obtained from a selection of healthy subjects. A high-resolution motion analysis system tracked the movement of skin markers placed on the midline and pelvis. Surface electromyography electrodes placed above L(5) collected data from multifidus. From the kinematics of skin markers during flexion extension with lifts up to 32 kg, and lateral bending with lifts up to 4.6 kg, the following parameters were estimated: lumbosacral angle and elongation, contribution of each lumbar segment to the lordosis reduction, relative pelvic/spine motion and trunk velocity. First, the average normal value for each estimated parameter was determined using 40 normal subjects. For each subject, the difference between his parameter and the normal was processed by an expert system generating a normality index varying from zero (perfect abnormal) to one (perfect normal). To develop the expert system's rules, a preliminary group of 20 very abnormal subjects were used, such that the normality index separated them from the normals. For validation, a set of 29 WCB sprain patients and another set of 42 discogram positive were selected. Each subject was tested and his computerized normality index calculated without any clinicians' input. The computerized normality index was compared with the clinicians' evaluation which was taken to be the gold standard. The Receiver Operating Characteristic technique was used to quantify the discrepancies. Results show that the expert system can detect clinically abnormal subjects with accuracy (sensitivity 83-91% and specificity >/=90%) while providing quantitative information on workers' functional capacities.

Journal Article↗
PubMed1995

Emergent radiofrequency ablation of the AV node in a neonate with unstable, refractory supraventricular tachycardia.

Supraventricular tachycardia due to accessory atrioventricular connections in infants is usually well-tolerated. Rarely an infant can have supraventricular tachycardia that is incessant and refractory to medical therapy. We describe a patient with supraventricular tachycardia detected prenatally that caused severe cardiac dysfunction and hemodynamic instability after birth.

Atrioventricular Node↗
PubMed1994

Diagnostic pitfall; interpretation of CA 19-9 concentrations in the presence of hepatic dysfunction.

A 50 year old man is described with hepatic dysfunction and chronic pancreatitis in whom greatly increased concentrations of the pancreatic tumour marker CA 19-9 combined with an abnormal appearance at endoscopic retrograde cholangiopancreatography lead to the false suspicion of pancreatic carcinoma. CA 19-9 concentrations should be interpreted with caution in patients with intrinsic liver disease or biliary obstruction.

Antigens, Tumor-Associated, Carbohydrate↗
PubMed1994

HUBNET: Wide Area Network utilization of Local Area Network medical reference and communication resources.

The State University of New York at Buffalo School of Medicine and Biomedical Sciences and its associated teaching sites have developed and partially implemented a regional Wide Area Network (WAN) in Buffalo and Western New York. The school wishes to use this WAN to deliver reference and communication resources to students, residents and faculty. The richest pool of easy to use reference and communication resources are PC software programs that are intended for individual workstations or at best, client-server, Local Area Network (LAN) implementation. HUBNET (Hospitals and University at Buffalo Library Resource Network), a project of the School of Medicine and the Library Consortium of Health Institutions in Buffalo offers integrated presentation of many such LAN resources over this regional WAN. The system crosses many institutional boundaries and reaches physically remote sites in a complex mix of information systems environments with few issues related to performance. The system design provides a level of ease of use that has brought many new users into active computer use while addressing integration into diverse information systems settings and networking environments.

Computer Communication Networks↗
PubMed1993

Aldolase-tubulin interactions: removal of tubulin C-terminals impairs interactions.

Aldolase copelleted with taxol stabilized microtubules with a Bmax = 0.74 moles of aldolase per mole of tubulin dimer. Removal of the carboxy terminals from microtubules with limited subtilisin digestion, decreased binding to 0.16 moles of aldolase per mole of tubulin dimer. Aldolase inhibited subtilisin cleavage of the C-terminals while triose phosphate isomerase, an enzyme that does not interact with microtubules, did not affect subtilisin activity. These data indicate that the carboxy terminals are involved in tubulin-aldolase interactions.

Animals↗
PubMed1992

Factors affecting the separation and loading capacity of proteins in preparative gradient elution high-performance liquid chromatography.

The optimum conditions for the purification of proteins by gradient elution in reversed-phase liquid chromatography were studied, with emphasis on the column length. Because of the strong dependence of the retention of proteins on the mobile phase composition, very short columns can be used successfully to perform analytical separations. A similar conclusion is extended to preparative separations. Columns with different lengths and diameters were used. The dependence of the loading capacity for touching band separation on the column length, diameter and volume was studied, in addition to the regeneration time between successive runs, the starting mobile phase composition and the necessary column efficiency.

Animals↗
PubMed1992

Forced splitting of human sleep in free-running rhythms.

The assumption of polyphasic sleep/wake regulation is based on the occurrence of nap-sleep at specific phase positions in the circadian cycle. Further support would be the split of the normal long major sleep episode into shorter components. Evidence for this hypothesis comes from the discovery of bimodal distribution in sleep duration. An experimental approach to test this hypothesis has been carried out by restricting sleep duration in free-running rhythms. The outcome was a biphasic distribution of sleep within a circadian cycle with sections of dissociation and synchronization of the two sleep blocks. The results show similarities with 'splitting', a phenomenon which has been found in animal studies. The relatively short duration of the different sections as well as the asymmetric distribution of the two sleep blocks in the circadian cycle leads to the assumption of a splitting of the major sleep episode and not of the circadian rhythm. Sleep split into two, relatively short sleep episodes of comparable duration contrasts with napping, which is characterized by an extra sleep episode in addition to the long major sleep.

Journal Article↗
PubMed1992

The effect of age on driving skills.

OBJECTIVE: To assess the effect of age on driving skills independent of the limitations related to disease or dementia. DESIGN: Prospective comparison of driving skills across three age groups. SETTING: A university-based research study of student and university-affiliated volunteers. PARTICIPANTS: Healthy elderly (age 65+), teen-age (age 18-19), and young adult drivers (age 25-35). Twenty subjects in each age group were recruited after meeting entry criteria for the study. MAIN OUTCOME MEASURES: Total error count and score on the Miller Road Test, a standardized road test developed by the Division of Bus and Traffic Safety in North Carolina. RESULTS: The elderly were found to have fewer errors than either of the two younger groups of drivers (P = 0.0013). Specific driving skills were judged to be either superior or unchanged in the elderly subjects in comparison to their younger counterparts. CONCLUSIONS: Road test skills appear to be well preserved in the healthy elderly population. More road test studies are needed on elderly individuals with mental and physical impairments to determine if road tests can play a role in identifying the driver at high risk for a crash.

Adolescent↗
PubMed1992

The effects of time delays on a telepathology user interface.

Telepathology enables a pathologist to examine physically distant tissue samples by microscope operation over a communication link. Communication links can impose time delays which cause difficulties in controlling the remote device. Such difficulties were found in a microscope teleoperation system. Since the user interface is critical to pathologist's acceptance of telepathology, we redesigned the user interface for this system, built two different versions (a keypad whose movement commands operated by specifying a start command followed by a stop command and a trackball interface whose movement commands were incremental and directly proportional to the rotation of the trackball). We then conducted a pilot study to determine the effect of time delays on the new user interfaces. In our experiment, the keypad was the faster interface when the time delay is short. There was no evidence to favor either the keypad or trackball when the time delay was longer. Inexperienced participants benefitted by allowing them to move long distances over the microscope slide by dragging the field-of-view indicator on the touchscreen control panel. The experiment suggests that changes could be made to the trackball interface which would improve its performance.

Costs and Cost Analysis↗
PubMed1992

Monoamines in the brain cerebrospinal fluid of facial pain patients.

The purpose of the study was to assay monoamines in cerebrospinal fluid (CSF) obtained from the trigeminal cistern of 64 patients with intractable facial pain. The CSF was analyzed for homovanillic acid (HVA), 5-hydroxyindoleacetic acid (5-HIAA), and 3-methoxy-4-hydroxyphenylglycol (MHPG), end-product markers of activity for the dopamine, serotonin, and norepinephrine systems, respectively. HVA averaged 121 ng/mL in these facial pain patients, compared to 150 to 550 ng/mL in 10 studies of ventricular brain CSF in assorted psychiatric and pain patients. 5-HIAA averaged 29 to ng/mL in our facial pain patients compared to 60 to 120 ng/mL in nine studies of ventricular brain CSF in assorted psychiatric and neurological patients. Trigeminal cistern CSF MHPG averaged 9 ng/mL, similar to the range of 13 studies of lumbar CSF of assorted psychiatric and pain diagnoses. These results indicate that (1) the electrochemical detection method provides a unique way of accurately measuring nanogram concentrations of multiple monoamines in a little as 0.25 mL of CSF; (2) trigeminal cistern and posterior fossa brain CSF monoamine metabolites reflect a different profile of dopaminergic and serotonergic functioning in these facial pain patients from that previously reported with lumbar CSF measurements of other patients; and (3) trigeminal sensory ganglion or brain dopamine and serotonin systems may be concomitantly dysfunctional in intractable facial pain.

Analysis of Variance↗
PubMed1991

Non-Hodgkin's lymphomas in patients with human immunodeficiency virus infection. Presence of Epstein-Barr virus by in situ hybridization, clinical presentation, and follow-up.

The authors studied all patients with serologic evidence of human immunodeficiency virus (HIV) infection and malignant non-Hodgkin's lymphoma (NHL) that presented at a single hospital from 1982 to 1989. Sixteen patients were identified, all white homosexual men with a mean age of 38.2 years. Lymphoma was the initial presentation of HIV infection in 37.5%. Sixty-two percent of the cases had a high-grade NHL, 31% had intermediate-grade, and 6% (one patient) had a low-grade lymphoplasmacytoid lymphoma. Extranodal involvement was present in 43.7%, with the gastrointestinal tract and liver being the most common sites. Actuarial survival was increased by treatment with methotrexate, doxorubicin, cyclophosphamide, vincristine, prednisone, and bleomycin (MACOP-B). Colorimetric in situ hybridization identified Epstein-Barr virus (EBV) in nine of the 14 cases hybridized. A statistically significant association of EBV with diffuse small noncleaved type (i.e., Burkitt's-like) (six of six) compared with other morphologic types (three of eight) was found (P = 0.025).

Adult↗
PubMed1991

The impact of a health education course on maternal knowledge: a comparative study in a low socioeconomic rural region.

A comprehensive health education course was designed for mothers in West Bank villages, a relatively low socioeconomic population. The course focused on nutrition, hygiene, child development, and first aid. It was taught by specially trained local instructors in small classes characterized by an individualized teaching method. To evaluate the contribution of the course, the level of knowledge in topics taught in the course was tested. The test was personally administered by trained interviewers to 241 course participants and to a comparison group of 284 mothers who had not participated. As expected, participants demonstrated higher level of knowledge than nonparticipants, regardless of the time since having taken the course. The course seems to have contributed to all participants, but mostly to women of lower education. In a multiple linear regression the two most significant predictors of knowledge were course participation and level of maternal formal education.

Educational Status↗