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Biomedical subjects

R L Williams

Publications and source records attributed to R L Williams.

At least 325 records · Page 18Linked to original sources
PubMed1980

Urban-rural differential in breast cancer incidence and mortality in Olmsted County, Minnesota, 1935-1974.

Between 1935 and 1974, 580 new cases of breast cancer were diagnosed among the residents of Rochester, and 187 cases were found among the women living in the remainder of Olmsted County, Minnesota. The age-adjusted incidence of breast cancer was 79.1 per 100 000 person-years among Rochester women and 56.3 per 100 000 person-years among the rural women, for an urban-rural ratio of 1.40:1. The rural incidence increased more rapidly than did the urban incidence during the period of the study, especially among women 50 years old or older; and the urban-rural ratio seemed to decline with time. No convincing explanation for these changes was found, but migration and increasing urbanisation of rural areas may be important factors. The greater urban incidence and the net migration of rural patients with breast cancer into the urban area explain the higher urban mortality rates for breast cancer.

Adult↗
PubMed1980

Computer analysis of Staphylococcus aureus phage typing data from 1957 to 1975, citing epidemiological trends and natural evolution within the phage typing system.

Computer analysis of Staphylococcus aureus phage ty ping data collected for over 18 years in a large research hospital showed a drastic decrease in the number of hospital epidemic strains. Phage lysis patterns gradually modified from those of earlier years and were a reflection of changes within the S. aureus reservoir, and not within the typing phages, since the typing phages were used from stable lyophilized stocks. There was increasing cross-lysis of S. aureus strains by phages of lytic groups I, II, and III, such that this grouping was no longer epidemiologically valid. A 61% increase in unique strains occurred from the period 1957 to 1975. Disappearance of the widely recognized epidemic strains was followed by a proliferation of unique strains with individual phage patterns. These increased from 38% in the period 1957 to 1962 to 62% in the period 1969 to 1975, indicating a trend toward a "one patient-one strain" situation. Nontypable strains decreased in more recent years from 16% (1957 to 1975) to 7% in 1978, following introduction of phages 94, 96, 292, and D-11. Pandemic S. aureus strain 80/81 first appeared in this hospital in 1959, 5 years after it was first reported in the United States. Strain 80/81 disappeared from the hospital in 1963, partly due to the advent of methicillin.

Bacteriophage Typing↗
PubMed1980

Breast cancer incidence, prevalence, mortality, and survivorship in Rochester, Minnesota, 1935 to 1974.

The epidemiologic features of breast cancer in Rochester, Minnesota, were studied over the 40-year period 1935 to 1974. During this time, the age-adjusted incidence rate increased 25% to 82.7 per 100,000 person-years. Most of the increase occurred among women 45 to 64 years of age. Overall, the incidence of breast cancer increased with advancing age, as did breast cancer prevalence, which was 901.4 per 100,000 women on Jan. 1, 1975. Age-adjusted mortality rates declined slightly from 24.9 to 23.3 per 100,000 person-years during the study period. Survival after the diagnosis of breast cancer seemed to improve somewhat among women who were less than 45 or more than 65 years old at the time of diagnosis. This was associated with a decline in the proportion of these women with regional lymph node involvement or distant metastases present at the time of initial diagnosis.

Adenocarcinoma↗
PubMed1979

Cesarean section in California--1960 through 1975.

The cesarean section rate has been rising in California since 1965. In this article, we describe the trend in cesarean section rates in California from 1960 to 1975 in relation to maternal and infant variables. Approximately proportionate increases in cesarean section rates by infant birth weight and maternal race were found. Cesarean section rates for women under 20 years of age and for those of first parity have risen proportionately more than rates for other age and parity groups. We also found that cesarean section rates for births at gestational age's exceeding 42 weeks have risen proportionately more than rates for births at other gestational ages. Maternal mortality ratios associated with cesarean section were twice those associated with noncesarean births for the years 1973, 1974, and 1975. Possible explanations of the current cesarean section rate include an increase in indications for the procedure, use of the fetal monitor, and the current medical-legal climate. The potential problems that cesarean section may create for the mother and infant are higher rates of iatrogenic prematurity and respiratory distress and of maternal morbidity and mortality.

Adult↗
PubMed1979

Increased prostaglandin synthesis in childhood diabetes mellitus.

Prostaglandins are synthesized from the fatty acids, linoleic and arachidonic acids, and are associated with increased platelet aggregation as has been found in blood from patients with diabetes mellitus. In the present study blood was obtained from 40 children with diabetes and from 20 control children for measurements of fatty acid and PGE1, PGE2, and PGF2alpha levels. The production of PGE2 and PGF2alpha was significantly elevated in blood from the children with diabetes at all times measured. The mean quantitative plasma linoleic acid levels were also higher in the patients. The increased PG synthesis may be related to the vascular problems that occur in patients with diabetes.

Adolescent↗
PubMed1979

Effect of vacuum fluctuation during milking on the development of intramammary infection from teat duct colonization by Staphylococcus aureus.

Twelve of twenty-one udder quarters with colonized teat ducts became infected within 13 d when milked with a machine producing large cyclic and irregular vacuum fluctuations in the teatcup; of 23 quarters milked under the same conditions, but with metal shields fitted inside the liners to protect the teat apex (Thiel, 1974), only 2 quarters became infected in the same period. The introduction of a post-milking teat disinfectant teat dip resulted in the elimination of orifice colonization from 15 teats dipped in Na hypochlorite solution (40 g/l available chlorine) and from all but 2 of 15 teats dipped in an iodophor solution (5 g/l available iodine).

Animals↗
PubMed1979

Measuring the effectiveness of perinatal medical care.

An outcome-based index of the effectiveness of perinatal care was empirically tested using 3,441,448 linked birth-death records. In order to construct the index, an "expected" perinatal mortality rate was computed for 504 California hospitals, based on each newborn's birth weight, sex, race, and plurality. The index was then defined as the ratio of the observed mortality rate to that expected. From the sixteen-fold range observed in the unadjusted rates, a two-fold variation could be attributed to differentials in the efficacy of medical care. The remainder resulted from differences in patient risk and from binomial variations. The observed--expected ratio was observed to be significantly correlated with a number of traditional indicators of medical care quality. Multiple regression techniques revealed that the mortality ratio was significantly lower in larger delivery services, in urban hospitals, in hospitals performing above-average numbers of cesarean sections in those recording Apgar scores, and in hospitals having higher specialist-to-generalist ratios. Conversely, the ratio was significantly higher in hospitals with larger percentages of Spanish-surnamed mothers and in private proprietary hospitals. By separating the index into its observed and expected components, the regression model accounted for 82 per cent of the variance in the observed perinatal mortality rates.

California↗
PubMed1979

Cesarean section, fetal monitoring, and perinatal mortality in California.

The rate of cesarean section in California has been growing at a compound rate of about 10 per cent per annum since 1969, coinciding with the advent of fetal monitoring. It is of interest, therefore, to study the distribution and efficacy of obstetric interventions. Information derived from the 1977 California birth cohort and a survey questionnaire was used to study the factors associated with the rate of cesarean section in 323 hospitals. Significant positive correlations were observed between the cesarean rate (CSR) and hospital factors indicative of a high degree of technology, including the proportion of labors electronically monitored. Significant negative correlations were observed between the CSR and hospital-specific variables suggestive of socioeconomically underprivileged patient populations. Other factors being constant, hospitals characterized by prepayment health care financing also had lower CSRs. A standaridized mortality ratio (SMR) based on 2.3 million births in the 1970--1976 cohorts was used to adjust the 1977 hospital specific perinatal mortality rates for birth weight, gestational age, sex, race, and plurality. The results show that hospitals which intervene technologically in a large proportion of births have lower risk adjusted perinatal mortality rates.

Adolescent↗
PubMed1979

Attenuation of prazosin effect on cardiac output in chronic heart failure.

The persistence of the hemodynamic effects of prazosin was studied in 12 patients with chronic congestive heart failure. Multidose evaluation involving five 5-mg doses showed the initial decrease in systemic vascular resistance and increase in cardiac index, stroke work index, and stroke volume index to be transient. Doubling the dose did not restore effect. Modest decreases in pulmonary capillary-wedge and mean arterial pressures persisted throughout the study. In six patients, plasma prazosin concentration measured at times of hemodynamic observations showed the initial hemodynamic effect of prazosin to attenuate upon further administration despite mean plasma concentrations that exceeded those measured after the first dose. In patients with chronic heart failure, resting hemodynamic studies suggest a rapid attenuation of prazosin-mediated hemodynamic effect in the presence of adequate plasma concentration. Recognizing this phenomenon, if long-term prazosin therapy for congestive heart failure is contemplated, we suggest the hemodynamic response in individual patients be monitored.

Adult↗
PubMed1979

The significance of serial measurements of serum complement C3 and C4 components and DNA binding capacity in patients with lupus nephritis.

Eighteen patients with systemic lupus erythematosus (SLE) and proliferative glomerulonephritis, underwent serial serum determinations of C3, C4, and native DNA binding capacity, as well as repeat renal biopsy 7 to 48 months (median 25 months) following initial biopsy. Highly significant correlations were found between serum C3 levels and renal histologic changes (P less than 0.0001), and between serum C3 levels and DNA binding capacity (P less than 0.03). Histologic deterioration correlated with depressed C3 levels, while improvement was associated with normalization of C3 levels. No correlation between renal histologic changes and either serum C4 levels or DNA binding capacity was found. The data suggest that the serum level of C3 is the best index of activity of lupus nephritis.

Adolescent↗
PubMed1979

Left atrial myxoma: association with acute coronary embolization in an 11-year-old boy.

An 11-year-old boy had clinical signs of an acute inferior wall myocardial infarction. On echocardiography, a left atrial myxoma was demonstrated. Coronary artery embolization from myxoma was confirmed by selective coronary arteriography. The tumor was removed 12 days after acute coronary embolization. The clinical value of echocardiography is demonstrated in this report of a successful surgical excision of left atrial myxoma in a child with a myocardial infarction due to tumor embolization.

Child↗
PubMed1978

Indomethacin in the treatment of idiopathic minimal lesion nephrotic syndrome.

Ten patients with idiopathic minimal lesion nephrotic syndrome were treated with indomethacin. Nine patients received the drug for five weeks and one patient for nine weeks. Indomethacin was administered in a dose of 1 mg/kg/day during the first week and 2 mg/kg/day, thereafter. At the end of the study, nine patients remained edematous and all had a urinary protein excretion greater than 50 mg/kg/day, within the nephrotic range. Indomethacin did not change the course of the disease and its use in the treatment of IMLNS is not advised.

Adolescent↗
PubMed1978

Impotence and blood pressure in the flaccid penis: relationship to nocturnal penile tumescence.

Evaluations of nocturnal penile tumescence (NPT) and penile blood pressure were performed on (1) a group of nondiabetics with normal NPT, (2) a group of nondiabetics with abnormally diminished NPT, and (3) a group of diabetics with abnormally diminished NPT. The 12 subjects in each group complained of impotence. Analysis of blood pressure data taken before the NPT evaluation suggests the possibility of selective low arterial blood pressure in impotent patients who show no obvious signs of other vascular disorders.

Blood Pressure↗