Biomedical subjects

P C O'Brien

Publications and source records attributed to P C O'Brien.

At least 271 records · Page 15Linked to original sources

PubMed1986

Neuropathy Symptom Profile in health, motor neuron disease, diabetic neuropathy, and amyloidosis.

We developed a true-or-false questionnaire with several hundred questions about symptoms encountered in peripheral neuropathy, to be scored by optical reader and computer. Responses were grouped into scales called "Neuropathy," "Weakness," "Sensory," "Autonomic," and subsets of these. Profiles in health were estimated for each scale based on responses from 300 healthy subjects 15 to 65 years old. The sensitivity and specificity of the scales were tested in patients with motor neuron disease, amyloidosis, or diabetes, with or without neuropathy. The questionnaire was useful in detecting neuropathy and staging severity, and in recognizing patterns that may have diagnostic implications.

Adolescent↗

PubMed1985

Use of femur length in estimation of fetal weight.

Fetal weight was estimated sonographically within 3 days of delivery in 103 cases. A stepwise regression analysis was performed to evaluate fetal sex, biparietal diameter, head circumference, abdominal circumference, and femur length as factors in estimation of fetal weight. A new formula for calculating fetal weight was derived. Fetal sex did not affect the results obtained. Incorporation of femur length improved the reliability of the weight estimate. Because of intrapopulation and interpopulation differences, institutions using obstetric ultrasound examination techniques should establish their own formulas for estimating fetal weight.

Birth Weight↗

PubMed1985

Near normoglycaemia improved nerve conduction and vibration sensation in diabetic neuropathy.

Twelve C-peptide deficient Type 1 (insulin-dependent) diabetic patients with abnormal peripheral nerve function were randomly assigned to continuation of conventional insulin therapy (CIT) or to continuous subcutaneous insulin infusion (CSII). There were no statistically significant differences at entry to the study between the two treatment groups in nerve function assessed by neurologic disability score, computer assisted sensation examination and measurements of amplitudes, distal latencies, F-wave latencies and somatosensory evoked potential latencies over the spine and conduction velocities of motor and sensory fibers of ulnar, median, peroneal, tibial, plantar and sural nerves. In addition, mean plasma glucose from 24 h profiles (12.5 vs 10.6 mmol/l, respectively) and HbA1 (11.0 vs 11.6%, respectively) did not differ significantly between the two treatment groups at entry. Despite improved glycaemia from CSII in 5 patients (one dropped out of the study after 2 months) contrasted to CIT in 6 patients (5.3 vs 9.9 mmol/l, respectively, p = 0.002) and HbA1 (8.5 vs 10.7%, respectively, p = 0.002), there were no significant differences in measurements of peripheral nerve function after 4 months. After 8 months of improved glycaemia (4.4 vs 10.2 mmol/l, p = 0.004) and improved HbA1 (8.3 vs 10.5%, p = 0.002), nerve conduction (p = 0.03) and vibratory sensation threshold (p = 0.002) were significantly better in patients treated with CSII than those who received CIT. The improvements in nerve function, although small, provide further evidence that some clinical endpoints of neuropathy are favorably influenced by improved control of glycaemia.

Adolescent↗

PubMed1985

Soft agarose culture human tumour colony forming assay for drug sensitivity testing: [3H]-thymidine incorporation vs colony counting.

In vitro drug sensitivity testing, both by optical colony counting and by a [3H]-TdR incorporation assay, was performed on human tumour cells proliferating in soft agar cultures. Cells from two different human tumour cell lines, 5 different human tumour xenografts, and 94 different primary human tumour specimens of various histologic types were studied. Regression analysis comparing the results of the colony counting assay and the [3H]-TdR assay revealed good to excellent correlations between the two assay endpoints for quantitating the effect of in vitro anticancer drug exposure for a large number of different agents. The presence of pre-existing tumour cell aggregates complicates the performance of the optical colony counting assay. The [3H]-TdR incorporation assay is more sensitive and reproducible than the colony counting assay when performed on samples containing a large number of initially seeded tumour cell aggregates.

Antineoplastic Agents↗

PubMed1985

Evaluation of pindolol dosage in hypertension by automatic indirect BP monitoring.

Pindolol, a nonselective beta-adrenergic blocking drug, lowered systolic and diastolic BP equally well during once-daily and twice-daily dosage. Side effects were few. Absence of supine bradycardia distinguished this drug from other beta-adrenergic blockers and likely was attributable to the agent's intrinsic sympathomimetic activity. Blood pressure variability was less during therapy. Automatic indirect BP monitoring reliably confirmed office and home BP recordings and indicated good control throughout waking and sleeping periods.

Adult↗

PubMed1985

A runs test based on run lengths.

A procedure is proposed for testing the hypothesis that Bernoulli trials (successes and failures) are independent with common probability of success. Equivalently, the procedure may be used to test the hypothesis that the arrangement of a fixed number of successes and failures was determined randomly. The procedure is based on a weighted linear combination of the variances of run lengths of successes and failures. It is shown to have desirable asymptotic properties and to be generally more powerful than the usual runs test, while preserving computational simplicity.

Axons↗

PubMed1985

Effects of progestational agents in treatment of endometrial carcinoma.

Progestational agents induced an objective response in 11.2% of 155 patients with advanced primary or recurrent endometrial carcinoma. Response rates decreased with decreasing tumor differentiation from 40% with Broders grade 1 lesions to 17.5, 2.4, and 0%, respectively, with grades 2, 3, and 4. 17 alpha-Hydroxyprogesterone caproate (Delalutin), 6,17 alpha-dimethyl-6-dehydroprogesterone (Colprone), and 6-methyl-6-dehydroprogesterone acetate (Megace) were the progestogens used; there was no significant advantage for any one agent. Overall, survival after initiation of hormone therapy was 40% at one year, 19% at two years, and 8% at five years. Survival was highly dependent on the degree of tissue differentiation (P less than .001) and was influenced significantly by the estimated tumor volume at the start of therapy (P less than .01) and by the time interval from primary treatment to the beginning of hormone therapy (P less than .01).

17 alpha-Hydroxyprogesterone Caproate↗

PubMed1984

Males exposed in utero to diethylstilbestrol.

An increased frequency of various genitourinary anomalies, infertility, and testicular cancer among males has been reported to follow intrauterine exposure to diethylstilbestrol, but not all studies have confirmed an association. This study was designed to determine whether a cohort of males exposed in utero to diethylstilbestrol had a higher frequency of urogenital abnormalities than an unexposed cohort. Biases in selection of exposed and control participants were minimized. Of 828 exposed and 676 control men studied by medical-record review, 265 exposed men and 274 controls also underwent a special clinical examination. Overall, the data suggest that diethylstilbestrol exposure of males in utero did not increase their risk of genitourinary abnormalities, infertility, or testicular cancer. Previously reported increased frequencies of these abnormalities in diethylstilbestrol-exposed men may have resulted from selection biases or differences in diethylstilbestrol use, or both.

Abnormalities, Drug-Induced↗

PubMed1984

Prognostic significance of histologic classification and grading of epithelial malignancies of the ovary.

Overall survival in 1938 women with epithelial ovarian cancer receiving primary treatment at Mayo Clinic was 35% at 5 years, 28% at 10 years, and 15% at 25 years. For most histologic cell types, observed differences in survival were more apparent than real since the behavior of different cell types was similar when compared stage for stage and grade for grade. Mucinous cystadenocarcinomas tended to be low grade and low stage, while serous cystadenocarcinomas tended to be high grade and high stage. For Stage I disease, factors other than cell type seemed to be more important in determining survival; specifically, Stage IA1 patients did significantly better than all other Stage I patients. In Stage III disease, the amount of residual tumor made a significant difference in survival for all grades. In Stage IV disease, the amount of residual made a highly significant difference in survival for grade 1 disease.

Adenocarcinoma↗

PubMed1984

Structural anomalies of the cervix and vagina in women enrolled in the Diethylstilbestrol Adenosis (DESAD) Project.

Among women exposed in utero to diethylstilbestrol (DES) and enrolled in the Diethylstilbestrol Adenosis (DESAD) Project, structural anomalies of the cervix or vagina were found in 25% of the 1,655 subjects identified by review of prenatal records, 43% of the 800 who themselves requested entry into the project, and 49% of the 1,089 referred by physicians but in only 2% of the 963 control subjects. Among the 367 cases found by record review to have complete information on the DES exposure, multivariate analysis indicated close association of the anomalies with the gestational week of first exposure and the total dose. Also, the prevalence rate of the anomalies was lower among subjects who had been pregnant and higher among those with later age at menarche.

Abnormalities, Drug-Induced↗

PubMed1984

Stage II cancer of the endometrium: a pathologic and clinical study.

Pathologically documented cases of stage II cancer of the endometrium in 52 women (adenocarcinoma in 43 and adenoacanthoma in 9) who were treated between 1952 and 1973 at the Mayo Clinic were studied retrospectively. Hysterectomy was necessary for inclusion in the study; 49 women received planned primary surgical treatment of their disease, and, in addition, 25 patients received radiation treatment postoperatively. Overall survival was 69.2% at 5 years. Variables found to have a statistically significant influence on survival were (1) extent of involvement in the endometrial cavity, (2) histologic grade of the tumor, and (3) maximal depth of invasion in either the myometrium or the cervix. The presence of abnormal nodes in women who had Wertheim hysterectomies and the use of radiation therapy did not appear to influence survival. It is concluded that primary treatment of stage II carcinoma of the endometrium by surgery and postoperative radiation produces acceptable results and, through the advantages of surgical staging, provides more exact knowledge of the true extent of the disease.

Adenocarcinoma↗

PubMed1984

Surgical treatment of lateral rectus muscle paralysis.

We conducted a retrospective study of 55 cases to investigate the effectiveness of three different surgical procedures (medial rectus muscle recession and lateral rectus muscle resection in 16 cases, the Hummelsheim procedure in 27 cases, and the Jensen procedure in 12 cases) in the treatment of lateral rectus muscle paralysis. All three procedures were equally effective. Shorter duration of lateral rectus muscle paralysis, greater preoperative lateral version, less contracture of the medial rectus muscle, and a traumatic origin for the sixth cranial nerve damage had a significant effect (P less than .05) on the final results of surgery.

Adult↗

PubMed1984

Designs for group sequential tests.

Several authors have proposed group sequential procedures to satisfy the ethical need in clinical trials for interim analyses. We propose here an alternative procedure that offers a good opportunity for early termination when initial results are extreme, while essentially maintaining the power provided by the procedure that applies when the corresponding test statistic is computed only at the predetermined time of final analysis. The new design is also sufficiently flexible to readily allow one to increase the maximum number of analyses for certain reasons such as unexpectedly slow accrual into the study, although not for reasons arising from consideration of outcomes observed at interim analysis.

Clinical Trials as Topic↗

PubMed1984

Changing patterns in the evaluation of renal masses: economic implications.

This study compares the cost of evaluating renal masses at the Mayo Clinic before and after the use of sonography and computed tomography gained clinical acceptance. Two hundred two adult patients discovered to have renal masses in 1973 were compared with 204 patients discovered to have renal masses in 1980. After adjustment for inflation and differences in the frequency of the various diagnoses, the average cost of evaluating patients in 1980 was 30% less than the cost in 1973; this difference is statistically significant (p = 0.024). The reduction in cost is attributable primarily to a 77% decrease in the use of angiography. The largest reduction in cost occurred in the evaluation of malignant lesions. The study demonstrates that the clinical use of new imaging methods in the evaluation of renal masses can be associated with decreased costs for the patient.

Adenocarcinoma↗

PubMed1984

Late survival after abdominal aortic aneurysm repair: influence of coronary artery disease.

To evaluate long-term survival in relation to preoperative risk factors, we reviewed 1112 patients undergoing abdominal aortic aneurysm (AAA) repair from 1970 to 1975. A 6-to 12-year follow-up was obtained on 1087 patients (97.7%) by chart review, death certificates, autopsy reports, and questionnaires returned by patients and referring physicians. Preoperatively 24% of patients had a history of prior myocardial infarction, 19.9% had a history of angina, and 40.4% were hypertensive. Emergency operation for ruptured aneurysm was performed in 6.5% and for expanding aneurysm in 3.4% of patients. The survival rate at 5 years was 67.5% and at 10 years was 40.7%. Cardiac-related problems were the most frequent cause of death (38%); 23% died of myocardial infarction and 15% from other heart disease or sudden death. Other causes included neoplasm (14.6%), other ruptured aneurysm (8.2%), and stroke (6.8%). Cause of death was unknown in 19.6%. A significant correlation of reduced survival time was noted in patients with advanced age and those with evidence of heart disease or hypertension. For patients without preoperative evidence of heart disease or hypertension, the 5-year mortality rate from myocardial infarction was 3.7%, compared with 11.7% for those with a positive history of hypertension and heart disease (p = 0.0001). For patients with no preoperative evidence of hypertension or heart disease, the length of survival after AAA repair was the same as that expected for the general population with the same age and sex composition. This study supports the contention that coronary angiography and prophylactic coronary bypass grafting should be performed selectively. Decisions regarding the need for coronary revascularization should be based on symptoms, noninvasive testing, and selective coronary angiography because aneurysmal disease alone is not shown in this study to increase the risk of death from myocardial disease. For patients with clinical findings of coronary artery disease, an aggressive diagnostic approach appears to be justified.

Aged↗

PubMed1984

Procedures for comparing samples with multiple endpoints.

Five procedures are considered for the comparison of two or more multivariate samples. These procedures include a newly proposed nonparametric rank-sum test and a generalized least squares test. Also considered are the following tests: ordinary least squares, Hotelling's T2, and a Bonferroni per-experiment error-rate approach. Applications are envisaged in which each variable represents a qualitatively different measure of response to treatment. The null hypothesis of no treatment difference is tested with power directed towards alternatives in which at least one treatment is uniformly better than the others. In all simulations the nonparametric procedure provided relatively good power and accurate control over the size of the test, and is recommended for general use. Alternatively, the generalized least squares procedure may also be useful with normally distributed data in moderate or large samples. A convenient expression for this procedure is obtained and its asymptotic relative efficiency with respect to the ordinary least squares test is evaluated.

Analysis of Variance↗

PubMed1984

En bloc (non-chest wall) resection for bronchogenic carcinoma with parietal fixation. Factors affecting survival.

Seventy-three patients (57 men and 16 women) underwent en bloc resection of lung and attached parietes between 1970 and 1982. All patients had documented malignant pleural invasion. Chest wall parietal pleura was invaded in 33 patients, pericardium in 14, phrenic or vagus nerve in nine, left atrium in five, superior vena cava in four, esophagus in two, diaphragm in one, and multiple structures in five. No patient underwent chest wall resection. Parietal pleurectomy was performed in all patients with involvement of the chest wall parietal pleura; 37 lobectomies and 36 pneumonectomies were performed. Operative mortality was 12.3%. The actuarial overall 5 year survival rate (Kaplan-Meier method) was 39.7%. We conclude that en bloc resection for primary bronchogenic carcinoma with invasion of adjacent intrathoracic structures, although associated with a significant mortality, can be performed with a reasonable likelihood of long-term survival.

Adult↗

PubMed1983

The therapeutic impact of temporal artery biopsy.

To evaluate the clinical usefulness of temporal artery biopsy in the diagnosis of giant-cell arteritis we followed up all 134 residents of Olmsted County, Minnesota, who had temporal artery biopsies between 1965 and 1980. Initial biopsies were positive for giant-cell arteritis in 46 cases and negative in 88. A history of jaw pain or claudication and the findings of a palpably abnormal temporal artery were significantly more common in the patients whose biopsy specimens showed giant-cell arteritis. Over a median follow-up period of 70 months (range 1-192) only 8 of the 88 biopsy-negative patients had clinical courses requiring long-term, high-dose corticosteroid therapy for giant-cell arteritis. In this population-based study temporal artery biopsy correctly predicted the subsequent need for corticosteroid therapy in 94% of cases: these findings indicate that biopsy should be done before patients are committed to long-term corticosteroid therapy.

Adrenal Cortex Hormones↗