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Biomedical subjects

M Dougherty

Publications and source records attributed to M Dougherty.

10 recordsLinked to original sources
PubMed1992

Computer-controlled spot-scan imaging of crotoxin complex crystals with 400 keV electrons at near-atomic resolution.

400 keV electrons yield a better relative image contrast than 100 keV electrons for a beam-sensitive organic crystal when spot-scan imaging is used [J. Brink and W. Chiu, J. Microscopy 161 (1991) 279]. A FORTRAN 77 program has been written to operate the spot-scan imaging system on a computer workstation under the VMS operating system which is interfaced serially to the JEOL4000 electron microscope. We demonstrate the application of this implementation by imaging crotoxin complex crystals embedded in either vitreous ice or glucose to 2.5 A resolution. The intensity strength of the structure factors of this protein crystal are different at low (> 10 A) resolution but similar at high resolution (< 10 A) for the two embedding media as expected from their scattering contrast difference. Based on our experience as judged from the electron diffraction patterns of highly tilted crystals, flat crystals embedded in glucose can be readily obtained. Furthermore, our spot-scan imaging system also has the option of correcting the focus gradient that is present in images of tilted specimens.

Computers↗
PubMed1992

Nonsurgical treatment of urinary incontinence.

Genuine stress urinary incontinence can be treated by surgical or nonsurgical methods. Conservative treatments include pelvic muscle exercises, hormonal and nonhormonal pharmacologic therapy, and functional electrical stimulation with vaginal or anal electrodes. All of these methods improve or cure stress incontinence in a significant proportion of selected women, with less cost and morbidity. Patients with genuine stress incontinence generally should have a trial of conservative therapy before corrective surgery is offered. Behavioral and pharmacologic methods, alone and in combination, are used for women with detrusor instability. Behavioral regimens, including bladder retraining and biofeedback, are particularly effective for urge and stress incontinence, but are dependent on compliance and motivation of both patient and caregiver. Drug therapy is effective, but with potential morbidity. As with genuine stress incontinence, surgical methods should only be employed for patients with detrusor instability who do not respond to nonsurgical treatment.

Adrenergic alpha-Agonists↗
PubMed1991

Preoperative chemotherapy for children with Wilms' tumor.

Five years ago, the use of preoperative chemotherapy for Wilms' tumor was adopted at this institution. Thirty children ranging in age from 5 months to 9 years had histologically confirmed Wilms' tumor (needle biopsy, n = 26; open biopsy, n = 4). Stage was determined by chest and abdominal computed tomography (CT) scan. Bilateral tumors were present in 6 children. All children received actinomycin D and vincristine from 3 weeks to 6 months before surgery. Seven children with bilateral tumors or stage IV disease also received adriamycin. CT-measured tumor masses shrunk in most cases. Subsequently, nephrectomy was performed in 23 patients and partial nephrectomy in 4, 2 of whom had bilateral disease. In 2 patients, residual bilateral well-differentiated epithelial tumor was not surgically resected. One child died before surgery. Reevaluation at delayed total or partial nephrectomy resulted in a downstaging of disease in 12 (41%). Further chemotherapy and radiation was based on the surgical stage. Postoperative chemotherapy (4 months to 2 years) was administered to all patients. The chest and/or abdomen were radiated in 12. Four patients (13%) died, 1 of radiation pneumonitis and 3 of the disease progression (2 with unfavorable histology, 1 of whom had bilateral disease). Two of 4 with unfavorable histology and 4 of 6 with stage IV disease have survived. It is concluded that this preoperative chemotherapy protocol is as effective as the National Wilms' Tumor Study (NWTS) protocol. The treated tumor is smaller, less friable, and easier to remove. Furthermore, because of downstaging, less radiation is necessary for cure.

Biopsy, Needle↗
PubMed1986

Cardiorespiratory fitness evaluation in climacteric women: comparison of two methods.

Middle-aged women are becoming increasingly interested in aerobic exercise. For exercise to be meaningful, training needs to be performed at 70% to 85% of VO2max for 20 minutes, three times weekly. The graded exercise test is the standard method used to determine maximum oxygen uptake, but this test is impractical for use in clinical practice. A cross-sectional study evaluated 163 women between 35 and 75 years of age by graded exercise test and compared the result with a matched group of 121 women tested by bicycle ergometer (predicted maximum oxygen uptake). Bicycle testing and the graded exercise test had a similar range of values; this was confirmed by 29 climacteric women performing both tests (r = 0.789). Menopausal status has no effect on cardiorespiratory fitness: the predicted maximum oxygen uptake of age-matched menstruating women was 27.4 +/- 6.3 ml/kg/min and that of nonmenstruating women was 25.3 +/- 4.2 ml/kg/min (p greater than 0.05). Bicycle ergometry can thus be used as a screen to determine the cardiorespiratory fitness status of climacteric women.

Adult↗
PubMed1976

Assay for type C virus in mouse sera based on particulate reverse transcriptase activity.

Assay of particulate reverse transcriptase activity in the sera from feral mice naturally infected with type C virus provides a sensitive and rapid procedure for the determination of in vivo virus infection. The results compare well with assays for infectious virus and with complement fixation or competitive radio-immunoassays for the p30 internal antigen of the virus.

Animals↗
PubMedDate not supplied

Effects of age, parity, and adherence on pelvic muscle response to exercise.

OBJECTIVE: To examine factors that affect pelvic muscle response to 12 weeks of pelvic muscle exercise. DESIGN: Repeated measures design in which intravaginal pressures during pelvic muscle contractions were recorded at baseline and after four exercise levels. SETTING: College of Nursing research site in Gainesville, Florida. PARTICIPANTS: Eighty-five parous, community-dwelling women, aged 35-78 years and without incontinence as a primary concern. INTERVENTIONS: A 12-week graded program of regular (three times per week, every other day) pelvic muscle exercise at home. MAIN OUTCOME MEASURES: The hypotheses were that younger age, lower parity, higher baseline intravaginal pressures, and adherence to the pelvic muscle exercise program each would result in significant improvement in maximum intravaginal pressures. RESULTS: The only factor showing significance in predicting a successful outcome was age (t = -2.29, df = 41, one-tail probability = .0136). CONCLUSIONS: Regular, graded exercise over several weeks is needed to build pelvic muscles, and some women who exercise do not improve. Although the reasons for not improving are unclear, age is a significant factor.

Adult↗
PubMedDate not supplied

The effect of circumvaginal muscle (CVM) exercise.

Circumvaginal muscle (CVM) home training based on principles of exercise physiology were tested on 48 healthy reproductive-age women. The effect of CVM exercise with a resistance device in place, CVM exercise without a device, and no exercise with device in place was studied. After random assignment to home training, CVM assessment was carried out prior to and after 6 weeks of CVM training at home. Each subject served as her own control and change scores of the three groups, on CVM variables were subjected to analysis of variance. Peak maximum pressure (PMP) was significantly different for the three groups. F = 4.56, df = 2.45, p = .016. PMP of exercise without a device was significantly different from the no exercise group (Dunett's test). Analysis of measurement error between- and within-subjects showed that the inherent variability between women was approximately four times larger than the measurement error. The results support the prescription of CVM exercise to hypertrophy the CVM, and indicate that further investigation of the large variance found in the pressure data is needed.

Adult↗