PubMed Health⌕ Search

Biomedical subjects

L R French

Publications and source records attributed to L R French.

At least 19 recordsLinked to original sources
PubMed1995

Are specific serum insulin levels low in impaired glucose tolerance and type II diabetes?: measurement with a radioimmunoassay blind to proinsulin, in the population of Wadena, Minnesota.

It has been suggested that serum insulin levels in subjects with recently diagnosed type II diabetes have been overestimated, and that after correction for proinsulin, true insulin levels are depressed rather than elevated. We tested this possibility in a cross-sectional study of a population-based sample of 328 adults living in Wadena, a Minnesota community in which residents are of northern European background. Specificity of insulin measurements was provided by an antibody blind to proinsulin and its major metabolite. Oral glucose tolerance and liquid mixed-meal (Ensure-Plus) tests were performed on separate days. Mean insulin levels before and 90 minutes after the mixed meal were as follows. Among 302 randomly ascertained adults not previously known to have diabetes, both fasting and postmeal levels in subjects with impaired glucose tolerance (IGT) and newly identified type II diabetes were equal to or greater than levels in subjects with normal glucose tolerance (fasting: normal 52 pmol/L, IGT 78, new type II 87; postmeal: 317, 565, and 406, respectively). The fasting insulin to glucose ratio was significantly increased in IGT and new type II diabetes subjects. Among 26 established (previously known) type II diabetic subjects not taking insulin, fasting levels were elevated and postmeal levels were normal in absolute terms (75 and 328), but were normal or low with respect to plasma glucose. Relationships among the groups were not materially changed by adjustment for body mass index (BMI), sex, age, or blood pressure. There was marked overlap of individual insulin levels from group to group. In summary, randomly selected adults in Wadena with IGT or asymptomatic diabetes showed, on average, elevated insulin levels, but physician-diagnosed diabetes was associated with relative diminution of serum insulin. In this population, the current view of insulin resistance in "early" diabetes was supported by insulin-specific measurements.

Adult↗
PubMed1994

Nature and incidence of self-reported adolescent work injury in Minnesota.

Most studies of adolescent work-related injury that have been published to date have been confined to administratively collected data available through state or national departments of labor and industry and/or occupational safety and health administrations. These data do not contain information on the severity or the sequelae of injuries. In addition, estimates of incidence may be biased due to inadequate data on the nature, amount, and seasonal variability of work done by adolescent workers. The present study is a cross-sectional survey of work and work injuries of 3,051 10th through 12th grade students from 39 high schools throughout Minnesota. Injury was defined as an event which caused any of the following: loss of consciousness, seeking medical care, and/or restricting normal activities for at least 1 day. The average hours of work per week during the summer and during the school year were 30 (95% Confidence Interval [CI] = 27, 33) and 16 (95% CI = 15, 17), respectively. There was no difference in hours worked between ethnic minorities and white students. The rate of reportable injuries was 12 per 100,000 hr worked (95% CI = 7, 18) for rural and 13 per 100,000 hr worked (95% CI = 7, 28) for urban females, 16 (95% CI = 9, 22) per 100,000 hr for urban males, and 20 (95% CI = 12, 28) per 100,000 hr for rural males. Ongoing medical problems were reported by 26% of the injured workers. Previous estimates of work-related injury to adolescents may have been low. More study is required to clearly define the incidence of injury and risk factors for these injuries.

Accidents, Occupational↗
PubMed1994

A reassessment of fasting plasma glucose concentrations in population screening for diabetes mellitus in a community of northern European ancestry: the Wadena City Health Study.

In current clinical and research practice, the determination of diabetic status depends largely on plasma glucose levels 2 h after the ingestion of a standard 75-g glucose load, the oral glucose tolerance test (OGTT). The OGTT, however, remains inconvenient, not highly reproducible, and costly, especially for large-scale studies and population screening tests. Fasting plasma glucose (FPG) determinations are convenient, reliable, and valid measures of glucose intolerance, but the currently prescribed cut-off point of 140 mg/dl (7.8 mM) lacks sensitivity. We evaluated the reliability and validity of fasting plasma glucose (FPG) values compared with other measures of hyperglycemia for a diagnosis of diabetes in a population-based study of carbohydrate metabolism in Wadena, Minnesota, a community of predominantly northern European ancestry. As a part of this effort, a random sample of Wadena adults, stratified by age and gender, plus all known, previously diagnosed diabetics participated in 2 days of baseline testing and were followed prospectively and retested 5 years later. Cross-sectional analyses of baseline data are presented in this article. Diabetic status was ascertained by administering a standard OGTT according to National Diabetes Data Group (NDDG) specifications. Sensitivity and specificity levels obtained when using a FPG cut-off point of 6.4 mM were 95.2% and 97.4%, respectively. In study subjects with no known diagnosis of diabetes, the FPG cut-off point of 6.4 mM performed reasonably well with a sensitivity and specificity of 67.7% and 97.4%, respectively. (ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Characteristics of adolescent work injuries reported to the Minnesota Department of Labor and Industry.

OBJECTIVES: The purpose of the study was to provide descriptive data and incidence data on adolescent work-related injuries and to determine whether such injuries are underreported to the Minnesota Department of Labor and Industry. METHODS: The study consisted of a 1-year survey of 534 adolescent work-related injuries reported to the Department of Labor and Industry and a cross-sectional survey of 3312 public high school students from throughout Minnesota. The high school survey used an abbreviated questionnaire with a subset of items from the Department of Labor and Industry survey. RESULTS: Ninety-six percent of the injuries were strains and sprains, cuts and lacerations, burns, bruises and contusions, and fractures. There were 11 hospitalizations; 4 were for burns that occurred during work in restaurants. Eighty workers (15%) reported permanent impairment as a result of their injuries. It was estimated that there were 2268 reportable injuries to working adolescents in Minnesota during the study year. CONCLUSIONS: The most common serious injuries were injuries to the lower back and burns. The demographic characteristics of adolescents whose injuries were reported to the Department of Labor and Industry were similar to those of injured adolescent workers identified through the high school survey. The results suggest that there is substantial underreporting of adolescent work injuries.

Accidents, Occupational↗
PubMed1992

Cardiovascular disease risk factors and glucose tolerance. The Wadena City Health Study.

Cardiovascular risk factors were examined in 453 subjects participating in the Wadena City Health Study, a population-based study to assess the relationship between diabetes and glucose intolerance with age. Each subject was classified as either having non-insulin-dependent diabetes mellitus (NIDDM), impaired glucose tolerance (IGT), or normoglycemia, using WHO criteria. Age- and body-mass-adjusted levels of systolic and diastolic blood pressure were lowest for those with normoglycemia, intermediate for those with IGT, and highest for those with NIDDM. Age- and body-mass-adjusted levels of high-density lipoprotein cholesterol were lowest for those with NIDDM, intermediate for those with IGT, and highest for those with normoglycemia, while triglyceride levels were highest for those with NIDDM, intermediate for those with IGT, and lowest for those with normoglycemia in women but not in men. Low-density lipoprotein cholesterol levels were lowest for those with NIDDM, intermediate for those with IGT, and highest for those with normoglycemia. With the exception of men with IGT, no differences by glycemic strata were observed for plasma total cholesterol. The prevalence of smoking showed no consistent pattern by glycemic status. These findings suggest that individuals with IGT have an atherogenic risk factor pattern that may put them at greater risk for coronary heart disease than those with normoglycemia. Intervention strategies such as diet, exercise, and/or drug therapy should be tested to evaluate whether these are effective in preventing conversion to overt diabetes and normalizing cardiovascular disease risk factors.

Adult↗
PubMed1992

Association between stimulated plasma C-peptide and age: the Wadena City Health Study.

OBJECTIVE: To assess age-related changes in stimulated plasma C-peptide in a population-based sample of adults. DESIGN: Cross-sectional study. SETTING: Wadena, Minnesota, a city of 4,699 residents (1980 census) in west central Minnesota, approximately 150 miles from Minneapolis/St. Paul. STUDY SUBJECTS: 344 non-diabetic subjects (NDDG standards) from a stratified random sample of the total adult population of Wadena, MN. The six-study strata were men and women from three age groups: young, 20-39 years of age; middle-aged, 40-59; and older, greater than 60 years of age. MEASUREMENTS: During a liquid meal of Ensure-Plus (Ensure-Plus challenge test; EPCT; Ross Laboratories), blood samples were taken for glucose, free fatty acids, creatinine, and C-peptide. Plasma C-peptide taken 90 minutes after the EPCT was used as a surrogate measure for insulin. Clinical tests included one-time samples for hemoglobin, glycosylated hemoglobin, plasma cholesterol, triglycerides, and lipoproteins. Physical measurements included height, weight, and blood pressure. Urine was assayed for C-peptide and creatinine. Assays of urine and plasma C-peptide used antibody M1221 (from Novo; Copenhagen, Denmark). MAIN RESULTS: No differences were observed for the relationship between age and C-peptide within each of the three age groups for men and the three age groups for women. However, the levels of plasma C-peptide for older men or women were statistically significantly higher than levels for the young age groups of the same sex; fasting plasma glucose also was higher for older groups of both sexes, and postmeal glucose was significantly higher for older women. There were decreases with age in urine C-peptide clearance for women and men; the decline for women was statistically significant. In multiple regression models for men alone and women alone, that controlled for age, post-meal plasma glucose best explained plasma C-peptide levels. For young men, plasma glucose alone provided the best prediction of plasma C-peptide levels; body mass index (BMI) and plasma glucose provided the best prediction for young women. For older men and both middle-aged and older women, a combination of urine C-peptide clearance and plasma glucose best predicted plasma C-peptide levels; for middle-aged men, BMI also contributed to the prediction. CONCLUSIONS: Secretion of insulin in response to an orally administered mixed meal is undiminished with age in non-diabetic adults.

Adult↗
PubMed1992

C-peptide response to meal challenge in nondiabetic and diabetic adults living in Wadena, Minnesota.

OBJECTIVE: The goal of the study was to provide cross-sectional descriptive data on the response of C-peptide to a vigorous meal stimulus in a population-based sample of nondiabetic adults compared with a population-based sample of adults with NIDDM. Available information is scanty, especially in subjects greater than 50 yr old. RESEARCH DESIGN AND METHODS: The group under study included 377 adults without previously known diabetes randomly chosen from the population of the city of Wadena, Minnesota, almost all of northern European background, and 88 adults with known diabetes. PCP was measured 90 min after ingestion of 480 ml liquid meal Ensure-Plus, which includes 95 g dextrose, 26 g protein, and 25 g fat. C-peptide also was measured in a 260-min urine collection after the meal challenge. Novo antibody M1221 was used for C-peptide assay throughout the study. Participants whose medical record indicated insulin-dependent diabetes with a history of acetone production were excluded from analyses. RESULTS: The distribution of UCP and PCP in this group of subjects appears very broad. Both the highest and lowest values for C-peptide were observed in individuals with diabetic glucose tolerance. The mean and median values in the nondiabetic group are higher than in previously published reports. After statistical adjustment for age, sex, BMI, and concomitant plasma glucose, participants with IGT produced significantly more C-peptide than the group with NGT (3.48 vs. 2.96 nM PCP, P less than 0.05). Participants with diabetic glucose tolerance and who were not taking insulin produced as much or more C-peptide than either the NGT or IGT groups, depending on the statistical model used for adjusting for plasma glucose. Diabetic participants who were taking insulin produced significantly lower amounts of C-peptide than any of the non-insulin-taking groups (approximately 30% of the C-peptide produced by the non-insulin-taking diabetic participants). A decline in PCP production with increasing years since diagnosis (5.7%/yr) was observed exclusively in the insulin-taking NIDDM participants. Effect modification by glucose tolerance classification was observed on the relationship between plasma glucose and PCP: PCP increased with increasing plasma glucose in NGT and IGT groups, but a nonsignificant negative relationship was exhibited in diabetic participants. CONCLUSIONS: The data suggest that two forms of NIDDM may exist, crudely distinguished by the clinical decision to use insulin to control blood glucose levels. The insulin-taking diabetic individuals may experience a greater likelihood of pancreatic failure, whereas non-insulin-taking diabetic individuals probably experience stable pancreatic function over the course of their disease. Longitudinal observation of the Wadena cohort will provide more insight into this possibility.

Adult↗
PubMed1990

A population-based study of craniosynostosis.

A population-based study of the incidence of craniosynostosis was conducted among residents of Olmsted County, Minnesota, born between 1 January 1976 and 31 December 1985. This study included only those with primary craniosynostosis who were less than 5 years of age at the time of diagnosis. Cases of craniosynostosis were classified as definite or probable. Definite cases had craniectomies or radiographic evidence confirming craniosynostosis, while patients for whom there was enough concern about craniosynostosis to order a skull radiograph were classified as probable cases. With these definitions, the incidence of craniosynostosis in Olmsted County was 3.1/10,000 births for definite cases (95% CI, 0.4-5.8) and 13.6/10,000 for all cases combined (95% CI, 7.9-19.3). These rates were compared to non-population-based minimal and maximal estimates of craniosynostosis frequency, 4/10,000 births and respectively. The rate observed in this study for definite cases, 3.1/10,000 births, is statistically consistent with the previous low estimate (observed/expected ratio 0.8, 95% CI, 0.2-1.8), and the rate observed for all cases in this study, 13.6, is consistent with the high estimate (observed/expected ratio 1.4, 95% CI, 0.8-2.1). Differences between definite and probable cases in this study are presented, along with comparisons with recent population-based data.

Child, Preschool↗
PubMed1990

Population-based study of impaired glucose tolerance and type II diabetes in Wadena, Minnesota.

The Wadena City Health Study was undertaken to assess the nature of type II (non-insulin-dependent) diabetes and its relationship to aging. This article reports the study methodology and prevalence estimates for type II diabetes and impaired glucose tolerance (IGT) for the adult population of Wadena, Minnesota. The sampling frame for the study included all known diabetic individuals and all other residents based on a complete citywide census of residents greater than or equal to 20yr of age. A stratified random sample that included three stratifying factors (age [20-39, 40-59, greater than or equal to 60 yr], sex, and self-reported weekly use of any prescribed medication was drawn from the other residents). The study protocol required diet preparation and two full mornings of testing. Data collected included height, weight, and blood pressure measurements and both a personal interview and a medications questionnaire. A 75-g oral glucose tolerance test (OGTT) and a test with a standard liquid meal (Ensure-Plus challenge test [EPCT], Ross) were done on two mornings, with the order of testing randomly assigned. Clinical tests included one-time samples for hemoglobin, glycosylated hemoglobin, plasma cholesterol, triglycerides, and lipoproteins. Blood samples for glucose and creatinine assays were taken during the OGTT; blood samples for glucose, free fatty acid, creatinine, and C-peptide were taken during the EPCT. Urine collections were performed for both challenge tests and assayed for C-peptide and creatinine. Seventy-one percent of the known diabetic subjects, and 65% of the stratified random sample participated in the study.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1985

A case-control study of dementia of the Alzheimer type.

A case-control study to assess factors of possible etiologic significance to dementia of the Alzheimer type was conducted with 78 male cases diagnosed in 1979-1982 at the Veterans Administration Medical Center in Minneapolis, Minnesota and age-race-sex-matched hospital and neighborhood controls (14 of 16 autopsied cases were histopathologically confirmed). Information was obtained on variables relevant to vital, genetic, and immunologic hypotheses, and on possible occupational and environmental exposures, drug use, psychologic stress, smoking, and alcohol consumption. The only major difference between patients with dementia of the Alzheimer type and controls was a significantly greater occurrence of antecedent head trauma in the patients (odds ratio = 4.50). This finding is consistent with the literature on posttraumatic dementia but its importance is presently unclear.

Adult↗
PubMed1985

Head injury as a risk factor for Alzheimer's disease.

A case-control study was performed in which the frequency of prior head injury was assessed in 78 patients with dementia of the Alzheimer type (DAT) and 124 control subjects matched for age, sex, and race. A history of head injury with loss of consciousness was reported in 25.6% of patients and 5.3% and 14.6% of hospital and neighborhood controls, respectively. Matched-pair analysis of patients and hospital controls yielded an odds ratio of 4.50, which was significant (p less than 0.01). The ranges of times of occurrence of head injuries were similar in patients and controls, spanning several decades. The findings suggest a possible etiologic role for head injury in DAT.

Aged↗
PubMed1985

Lead toxicity.

Explore the source record for details and available documents.

Adult↗
PubMed1983

Inhibitory effect of the bovine conceptus on lymphocyte stimulation.

Experiments were conducted to determine whether the preimplantation bovine conceptus produces an immunosuppressant as measured by the inhibition of lectin-induced incorporation of thymidine into lymphocytes. The results of the experiments clearly indicated that media from cultured 18-d-old embryos inhibited lectin-induced incorporation of thymidine into bovine lymphocytes. The inhibitory substance was not produced by heat-killed cells from the conceptus, was not toxic to lymphocytes, was not lectin-specific, but did act in a partially reversible manner. The inhibitor had no apparent effect on porcine lymphocytes, a moderate effect on ovine lymphocytes and a potent effect on bovine lymphocytes. The substance appeared to have a molecular weight of between 500 and 10,000 and was ether insoluble and heat stable. The possible chemical nature of the inhibitor and its potential effect on survival of the preimplantation conceptus are discussed.

Animals↗
PubMed1982

Control of luteal function during pregnancy: antiluteolytic and luteotropic properties of the developing mouse conceptus.

Eight experiments were conducted to examine the influence of the conceptus on luteal function in mice. In uterine intact pseudopregnant mice, exogenous treatment with placental extracts or pregnant mouse plasma from Day 8 or Day 10 of gestation did not prolong the life span of the corpora lutea (CL). The interestrous interval (IEI) of hysterectomized pseudopregnant mice was extended by treatment with Day 10 placental extract and was accompanied by elevated plasma progesterone, consistent with the luteotropic nature of the Day 10 conceptus. The IEI of uterine intact pseudopregnant mice was prolonged by the presence of ectopically developing blastocysts and was further extended by a treatment with Day 10 placental extracts but not by treatment with Day 8 placental extracts. Although the ectopic blastocyst delayed the effect of the uterine luteolytic mechanism, there was no indication of luteotropic activity: the ectopic blastocysts were unable to activate the CL of the estrous cycle. In addition, plasma progesterone and 13,14-dihydro-15-keto-prostaglandin F2 alpha (PGFM) were measured in pseudopregnant, hysterectomized pseudopregnant and pregnant mice on Day 2 through 13 post-mating. The results of these experiments suggest a two-step mechanism in prolonging luteal function during pregnancy which involves two different substances. This mechanism involves an initial signal from the conceptus which blocks the uterine luteolytic mechanism and a subsequent luteotropic stimulus from the Day 10 conceptus which extends luteal life span to approximately the length of gestation.

Animals↗
PubMed1982

Effects of the uterus and mid-pregnancy conceptus on luteal lifespan of the rat.

Hysterectomy on or after Day 10 resulted in a quick return of pseudopregnant rats to oestrus but the interval to oestrus in pregnant rats was significantly longer (P less than 0.01), indicating that the gravid uterine horn interfered with uterine-induced luteolysis by Day 10. When pseudopregnant rats were injected with extracts of conceptuses or pregnant rat serum (PRS), samples collected on Days 10 or 12 of pregnancy delayed the return to oestrus (P less than 0.01 for conceptus extracts, P less than 0.05 for PRS) and serum progesterone concentrations on Day 13 of pseudopregnancy were higher (P less than 0.01) than in controls. Bioassays utilizing mammary development or inhibition of oestrus in virgin cyclic rats as endpoints failed to detect lactogenic activity in Day 10 conceptus extracts or PRS, and radioreceptor assays using bovine prolactin (NIH-B5) as a standard showed that Day 10 extracts had only about 2--3% of the lactogenic activity found in Day 12 extracts. Injections of dilutions of Day 12 extracts with 2 or 4 times the lactogenic activity as Day 10 extracts did not extend pseudopregnancy. These results suggest that by Day 10 the conceptus produces a factor capable of interfering with luteolysis and that this factor is not placental lactogen.

Animals↗
PubMed1982

Plasma concentrations of progesterone and 13,14-dihydro-15-keto prostaglandin F-2 alpha in pregnant, pseudopregnant and hysterectomized pseudopregnant mice.

Hysterectomized pseudopregnant mice had plasma progesterone concentrations on Days 6, 8, 10 or 12 after mating that were greater (P less than 0.05) than those of intact pseudopregnant mice and lower (P less than 0.01) than those of pregnant mice. Concentrations of 13,14-dihydro-15-keto-prostaglandin F-2 alpha on Days 6, 7, 8, 9 or 10 after mating were lower (P less than 0.05) in pregnant and higher (P less than 0.01) in intact pseudopregnant mice than in hysterectomized pseudopregnant mice. The results support the conclusion that there are uterine and extra-uterine luteolytic mechanisms which are mediated by prostaglandin and are perhaps functional by Day 6 of pregnancy.

Animals↗