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Biomedical subjects

B A Johnson

Publications and source records attributed to B A Johnson.

At least 199 records · Page 11Linked to original sources
PubMedDate not supplied

Ondansetron for reduction of drinking among biologically predisposed alcoholic patients: A randomized controlled trial.

CONTEXT: Early-onset alcoholism differs from late-onset alcoholism by its association with greater serotonergic abnormality and antisocial behaviors. Thus, individuals with early-onset alcoholism may be responsive to treatment with a selective serotonergic agent. OBJECTIVE: To test the hypothesis that drinking outcomes associated with early vs late-onset alcoholism are differentially improved by the selective 5-HT(3) (serotonin) antagonist ondansetron. DESIGN: Double-blind, randomized, placebo-controlled clinical trial. SETTINGS: University of Texas Health Science Center in Houston (April 1995-June 1998) and University of Texas Health Science Center in San Antonio (July 1998-December 1999). PARTICIPANTS: A total of 321 patients with diagnosed alcoholism (mean age, 40.6 years; 70.5% male; 78.6% white) were enrolled, 271 of whom proceeded to randomization. INTERVENTIONS: After 1 lead-in week of single-blind placebo, patients were randomly assigned to receive 11 weeks of treatment with ondansetron, 1 microg/kg (n = 67), 4 microg/kg (n = 77), or 16 microg/kg (n = 71) twice per day; or identical placebo (n = 56). All patients also participated in weekly standardized group cognitive behavioral therapy. MAIN OUTCOME MEASURES: Self-reported alcohol consumption (drinks per day, drinks per drinking day, percentage of days abstinent, and total days abstinent per study week); and plasma carbohydrate deficient transferrin (CDT) level, an objective and sensitive marker of transient alcohol consumption. RESULTS: Patients with early-onset alcoholism who received ondansetron (1, 4, and 16 microg/kg twice per day) compared with those who were administered placebo, had fewer drinks per day (1.89, 1.56, and 1.87 vs 3.30; P =.03, P =.01, and P =.02, respectively) and drinks per drinking day (4.75, 4.28, and 5.18 vs 6.90; P =.03, P =.004, and P =.03, respectively). Ondansetron, 4 microg/kg twice per day, was superior to placebo in increasing percentage of days abstinent (70.10 vs 50.20; P =.02) and total days abstinent per study week (6.74 vs 5.92; P =.03). Among patients with early-onset alcoholism, there was a significant difference in the mean log CDT ratio between those who received ondansetron (1 and 4 microg/kg twice per day) compared with those who received the placebo (-0.17 and -0.19 vs 0.12; P =.03 and P =.01, respectively). CONCLUSION: Our results suggest that ondansetron (particularly the 4 microg/kg twice per day dosage) is an effective treatment for patients with early-onset alcoholism, presumably by ameliorating an underlying serotonergic abnormality. JAMA. 2000;284:963-971

Adult↗
PubMedDate not supplied

Protein L-isoaspartyl methyltransferase in postmortem brains of aged humans.

The specific activity of protein L-isoaspartyl methyltransferase, an enzyme implicated in the metabolism of damaged, isoaspartate-containing proteins, has been measured in postmortem samples of parietal cortex from 30 individuals (19 with Alzheimer's disease and 11 controls). Methyltransferase specific activity was positively correlated with age at death, increasing by 2.9 pmol/min/mg of protein for every ten years of age (r = .51, p less than 0.005). This correlation was significant in the control and Alzheimer's disease groups alike. Specific activity also appeared to be about 15% higher in females than in age- and diagnosis-matched males (p less than 0.05). No significant differences were observed between age- and sex-matched Alzheimer patients and controls, suggesting that a deficiency in this enzyme is not responsible for the accumulation of abnormal proteins in Alzheimer's disease.

Aged↗
PubMedDate not supplied

Evaluation of two ELISA's for detecting Chlamydia trachomatis from endocervical swabs.

Two enzyme immunoassays (EIAs) detecting Chlamydia trachomatis from endocervical swabs, Syva MicroTrak (MT) and Abbott Chlamydiazyme (CZ), were compared with a tissue culture (TC) standard. Initially, 8% (100 of 1250) of specimens were TC positive, yielding sensitivities of 94% (94 of 100) for MT and 79% (79 of 100) for CZ with identical 98% specificities (1129 of 1150 for MT and 1130 of 1150 for CZ). Discrepant specimens were retested by both EIAs and assayed for elementary bodies (EBs) by a fluorescent antibody test. After discrepancy analysis, 9.5% (118) of 1240 patients were either TC or EB positive, yielding sensitivities of 94.1% for MT (111 of 118) and 79.7% for CZ (94 of 118) with identical specificities of 100% (1122 of 1122). These results indicate that the MT is significantly more sensitive (p less than 0.05, McNemar test) than CZ in detecting C. trachomatis from endocervical swabs.

Adolescent↗
PubMedDate not supplied

Cue reactivity in cocaine-dependent subjects: effects of cue type and cue modality.

Thirty cocaine-dependent subjects were enrolled into a cue-laboratory study to determine the specificity and sensitivity of this paradigm as a craving measure. Subjects experienced three cue types (i.e., cocaine, arousing, and neutral stimuli) in three cue modalities (i.e., audio, visual, and manual). Cue types were administered in different experimental sessions with a period of 2 to 3 days between sessions. Our results showed that subjective and physiological craving for cocaine was relatively specific for the cocaine cue as compared with either the arousing or the neutral cue. The relative sensitivities of the cue modalities in decreasing order was manual, audio, and visual. We suggest that a modified conditioned-cue paradigm could be a useful tool in the repeated assessment of craving during a clinical study.

Adult↗
PubMedDate not supplied

The radiologist and informed consent: a review, comments and proposals.

In summary, the physician's duty to inform has been described and discussed. The minority and majority rule have also been defined and analyzed along with the major causes of physician failure and resistance to disclose risks. In a proper physician-patient relationship, informed consent controversy should be rare. A calm, clear, direct and properly documented disclosure of risks of a procedure is the best defense in any jurisdiction.

Disclosure↗
PubMedDate not supplied

Comparison of tension band wire and cancellous bone screw fixation for medial malleolar fractures.

A comparison study of the relative strength of tension-band fixation versus cancellous bone screw fixation of medial malleolar ankle fractures was performed on ten fresh-frozen lower limbs from five cadavers. The mean force recorded at clinical failure using cancellous screws was 60.98 N (range 33.49 to 117.86 N) compared with 129.30 N using tension-band fixation (range 85.20 to 194.64 N). Therefore, cancellous screws exhibited only 47.16% the strength of tension-band wiring at clinical failure.

Aged↗
PubMedDate not supplied

The effect of screw holes on bone strength.

Internal fixation devices continue to be used in the fixation of foot and ankle fractures and osteotomies. Because of the increased use of fixation techniques, postoperative care following removal of internal fixation devices assumes a vital role in the success of these procedures. Using 10 fibulas from 5 cadavers, the authors tested the resistance of 5 intact fibulas and 5 contralateral fibulas with one 3.5-mm. drill hole to bending forces. The mean load at failure of the intact fibulas was 360.86 N (range 181.69-800.14 N), whereas the mean load at failure of the drilled fibulas was 215.20 N (range 66.49-600.61 N). The drilled fibulas displayed failure with the application of 59.63% of the mean load applied to the intact fibulas at failure (p = 0.007).

Aged↗
PubMedDate not supplied

Reconstructing a sense of self in patients with chronic mental illness.

TOPIC: The loss and reconstruction of self in patients with a chronic mental illness. PURPOSE: To describe the loss of self and its reconstruction. SOURCES: The authors' own clinical work and review of the literature. CONCLUSIONS: Nurses can help patients who have undergone a loss of self to discover a more active sense of self, take stock of the self, put the self into action, and use the enhanced self as a refuge. This process involves the fostering of hope.

Adaptation, Psychological↗
PubMedDate not supplied

Ductography: how to and what if?

Ductography of the breast is an underused procedure that often helps define the cause of unilateral, single-pore, spontaneous nipple discharge. Since nipple discharge may be caused by benign tumors, such as papillomas, or by carcinoma, such as ductal carcinoma in situ, identification of intraductal abnormalities with ductography is important. Further, diagnostic ductography and preoperative ductography help guide accurate surgical intervention. Without prior ductography, central duct excision may not result in removal of the abnormal ductal tissue or may result in removal of only a portion of the abnormal ductal system, causing the extent of disease to be effectively understaged. Once fundamental ductographic principles are learned, the procedure is easy to perform. If extravasation occurs, ductography is rescheduled for 7-14 days later. Elimination of air bubbles from the cannula, syringe, and extension tubing is vital. When reflux occurs, radiologists must be aware of a possible tumor in the distal-most duct. When ductal ectasia or fibrocystic changes are the cause of the discharge, conservative follow-up may be considered. Diagnostic radiologists who learn the technique of ductography and include it in their evaluation of nipple discharge will improve their interdisciplinary approach to this important sign of breast cancer.

Breast Diseases↗
PubMedDate not supplied

Positioning for vertical integration through clinics "without walls".

Authors Bruce A. Johnson, J.D., M.P.A., and Darrell Schryver, D.P.A., offer the clinic without walls model as a transitory step to full vertical integration. They write that this model "may enable physicians to address the key issues associated with managed care and integration in a more gradual, controlled fashion.

Comprehensive Health Care↗
PubMedDate not supplied

Integrated provider networks--a primer.

Integrated provider networks are burgeoning. With acronyms like MSO, IPA, PHO, IPN, etc., integration can be confusing to the uninitiated. Gerald A. Niederman, J.D., of Faegre & Benson, and Bruce A. Johnson, J.D., M.P.A., of the MGMA Management Consulting Services, offer a primer on integrated provider networks.

Foundations↗