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Biomedical subjects

W M O'Fallon

Publications and source records attributed to W M O'Fallon.

At least 361 records · Page 20Linked to original sources
PubMed1978

Endothelial cell loss during penetrating keratoplasty.

We studied the central donor endothelium of 27 clear, penetrating corneal transplants with the specular microscope before and after keratoplasty. We examined the donor corneas first, in vitro, while they were immersed in McCarey-Kaufman preservation medium before transplantation. This preoperative examination proved valuable for screening donor corneas, several of which were not used on the basis of the specular microscopic appearance alone. We examined the donor endothelium again within one week after keratoplasty and calculated the number of endothelial cells per square millimeter from photographs. The reproducibility of the counting method was acceptable. Comparison of the examinations before and after transplantation on each patient showed that, on the average, 23% of the donor endothelial cells were lost during keratoplasty. The 12 phakic transplants lost significantly more endothelial cells than did the 15 aphakic grafts (37% vs 12%). A possible explanation for the increased cell loss in phakic keratoplasties is the shallow anterior chamber present during the initial placement of the graft. Phakic grafts that were larger or had shorter time intervals between donor death and enucleation lost fewer cells. Aphakic transplants had larger postoperative corneal thicknesses than did phakic transplants.

Adolescent↗
PubMed1978

A comparison of single fiber and routine EMG in normal subjects and patients with inflammatory myopathy.

We performed electromyography on the vastus lateralis muscle in 36 normal subjects and in 18 patients with inflammatory myopathy using a specially constructed dual electrode. This permitted simultaneous recording of a motor unit from a single fiber (SF) and standard sized electrode surface. We then correlated parameters of the SF potential (jitter, blocking, fiber density and duration) and the motor unit potential (MUP) (number of phases, duration) for different sites within the same individual. The mean values for the above parameters were correlated between individuals, and the group means were compared for the control and the inflammatory myopathy group.

Adult↗
PubMed1977

Exogenous estrogen and endometrial carcinoma: case-control and incidence study.

Recent independent case-control studies have indicated that treatment with exogenous estrogen is associated with an increase in the risk of endometrial cancer. This question was studied in Olmsted County, Minnesota, by identifying all cases of endometrial cancer among residents over a 30 year period (1945 through 1974) and by matching four controls to each of the 145 patients. The rate of past exposure to any exogenous estrogen for any duration was about the same for patients as for controls. However, the estimated relative risk of endometrial cancer associated with conjugated estrogen treatment of 6 months or longer was 4.9 (P less than 0.01), and this increased to 7.9 (P less than 0.01) with exposure for 3 years or longer. The risk increased with larger doses (1.25 mg. or more) and continuous administration of conjugated estrogens. The incidence of endometrial carcinoma over the three decades of the study, corrected for an increasing rate of hysterectomy, was constant. Thus to this time, the low rate of use of conjugated estrogens in this region over the past 30 years apparently has not had an appreciable impact on the incidence of endometrial cancer.

Dilatation and Curettage↗
PubMed1975

Rauwolfia derivatives and breast cancer. A case/control study in Olmsted County, Minnesota.

In response to three reports of an association between rauwolfia derivatives and breast cancer, a case/control study was undertaken in Olmsted County, Minnesota. Comparison of a cohort of women with breast cancer to an age-match cohort of women with cholelithiasis failed to show any meaningful differences in the two groups except with respect to a history of hypertension. The rates of use of rauwolfia derivatives by hypertensive cases and controls were identical--which, along with other considerations, leads to the conclusion that an association between the use of rauwolfia derivatives and breast cancer is unlikely.

Age Factors↗
PubMed1975

Epidemiologic study of migraine symptoms in young women.

Information about headache was collected from a nonclinical sample of 451 women, aged 15 to 44, in 12 major U.S. cities. Questions were asked in regard to the presence in the past year of headache, and of the following characteristic symptoms of migraine: unilateral location, throbbing quality, visual aura, vomiting, and severity sufficient to affect daily activities. Twenty-three percent of the women had headaches with two or more of these characteristics. The frequency of such symptoms was significantly greater in women who smoked or formerly had smoked cigarettes, in women with lower incomes and poor education, and in women with a history of hypertension, stomach ulcer, fainting, and a variety of emotional complaints. The frequency of reported symptoms of migraine did not vary significantly according to age, race, marital status, use of oral contraceptives, or number of living children. These findings do not support the commonly held clinical impression that migraine is uncommon among blacks or among the poorly educated.

Adolescent↗
PubMed1975

Benign breast lesions and subsequent breast carcinoma in Rochester, Minnesota.

Case histories of 444 female patients (Rochester residents) with benign breast disease pathologically diagnosed between 1935 and 1949 were studied prospectively for the development of breast cancer. After exclusion of unsuitable cases, 370 remained for review of pathologic diagnoses and statistical analysis. Breast cancer developed in 14 (3.8%) within a median period of 13.5 years after the diagnosis of benign breast disease. Most of these malignancies occurred within 10 years after the original diagnosis. Patients in whom the original diagnosis was chronic cystic mastitis developed breast cancer 2.9 times more frequently than expected. Breast cancer developed 10 times as often as expected in those patients of ages 40 to 49 at the time of diagnosis of breast malignancy. This evidence shows that a more intensive follow-up of patients with confirmed chronic cystic breast disease is justified, especially among those of ages 30 to 49 years.

Adenocarcinoma↗
PubMedDate not supplied

Long-term use of oral anticoagulants and the risk of fracture.

BACKGROUND: Vitamin K participates in bone metabolism and, since oral anticoagulants antagonize vitamin K, their use may increase the risk of osteoporosis. OBJECTIVE: To evaluate fracture risk at all skeletal sites following exposure to oral anticoagulants. METHODS: In a population-based retrospective cohort study, 572 Olmsted County, Minnesota, women 35 years or older at their first lifetime venous thromboembolism event between 1966 and 1990 were followed up for fractures. Risk was assessed by comparing new fractures with the number expected from sex- and age-specific fracture incidence rates for the general population (standardized incidence ratio [SIR]). RESULTS: Altogether, 480 fractures occurred during 6314 person-years of follow-up. Increasing exposure to oral anticoagulation was associated with an increased SIR for vertebral fractures: at less than 3 months of exposure, 2.4 (95% confidence interval [CI], 1.6-3.4); 3 to less than 12 months, 3.6 (95% CI, 2.5-4.9); and 12 months or more, 5.3 (95% CI, 3.4-8.0); and for rib fractures: at less than 3 months, 1.6 (95% CI, 0.9-2.7); 3 to less than 12 months, 1.6 (95% CI, 0.9-2.6); and 12 months or more, 3.4 (95% CI, 1.8-5.7). The data revealed no increased risk for other types of fractures. Oral anticoagulation for 12 months or more was an independent predictor of vertebral fractures (P = .009) and rib fractures (P = .02), but not other fractures. CONCLUSIONS: Long-term exposure to oral anticoagulation is associated with an increased risk of vertebral and rib fractures. The mechanism by which this occurs is still unclear and needs further investigation.

Administration, Oral↗