Orlando Gomez-Marin

Test-retest reliability of the Minnesota Leisure Time Physical Activity Questionnaire☆

The test-retest reliability of the Minnesota Leisure Time Physical Activity Questionnaire was assessed by two administrations of the questionnaire at a five-week interval in 140 adults from a general population sample and at a two-week interval in 150 male participants in the Multiple Risk Factor Intervention Trial (MRFIT). In both study populations, there was a slight, nonsignificant drop in reported leisure time energy expenditure between the test and the retest. The largest test-retest differences in estimated energy expenditure were found among those reporting greater levels of energy expenditure. Nevertheless, in both study populations Spearman rank correlation coefficients between the test and retest were high--0.79 to 0.88 for total activity and ranging 0.69-0.86 among the light, moderate, and heavy intensity subcategories. The high reliability of the Minnesota Leisure Time Physical Activity Questionnaire corroborates its utility in epidemiologic research.

Sudden death and acute myocardial infarction in a metropolitan area, 1970-1980. The Minnesota Heart Survey

To determine the causes of the nationwide decline in deaths due to coronary heart disease, the Minnesota Heart Survey enumerated coronary deaths among persons 30 to 74 years old in Minneapolis-St. Paul. The survey also ascertained rates of hospitalization and case fatality during hospitalization for acute myocardial infarction. For deaths occurring between 1970 and 1978 that were due to coronary heart disease, the rates outside the hospital declined by 43 per cent in men and 40 per cent in women, and the rates in hospital emergency rooms increased by 311 per cent in men and 200 per cent in women. In both these years about two thirds of all such deaths occurred outside hospital wards. Between 1970 and 1980, hospitalization rates for acute infarction in persons 30 to 74 years old declined 8 per cent among men and 26 per cent among women, and case fatality in the hospital in persons 45 to 74 years old declined 29 per cent in men and 27 per cent in women. These changes are probably due to the combined influence of changes in risk factors in the population and improved care of patients with acute myocardial infarction before and during hospitalization.

Persistent elevation of blood pressure among children with a family history of hypertension: The Minneapolis children's blood pressure study

We examined the blood pressure of children with and without a family history of hypertension in a longitudinal study. Supine blood pressures were first measured in schoolchildren (mean age 8 years) in 1978 and then on nine more occasions until 1986. Blood pressures of parents were measured in the seated position and their medical histories were obtained in home interviews carried out between 1978 and 1979. Children with a family history of hypertension had a higher mean systolic blood pressure (SBP) at the first screening compared to children without such a family history. This difference persisted at each of the succeeding nine school visits. The parents in hypertensive families had a lower income, greater body weight, were less well-educated and were more likely to be black than parents in families without a history of hypertension. Mothers in hypertensive families were more likely to have a history of heart disease and elevated blood pressure during pregnancy than mothers in normotensive families. The correlations between blood pressure of mothers and their children tended to be higher than those between fathers and their children. Elevated blood pressure emerges well before adolescence among children with a family history of hypertension and the family environment appears to play an important role in its development.

Effect of low sodium diet or potassium supplementation on adolescent blood pressure.

The roots of essential hypertension extend back into the first two decades of life, suggesting that effective intervention during those years may lead to a reduction in the incidence of adult hypertension. Decreasing the dietary sodium/potassium ratio offers a potentially effective approach to blood pressure reduction. This study tested the feasibility of 3-year sodium reduction or potassium supplementation in adolescents and the effect of these interventions on the rate of rise of blood pressure during adolescence. After 19,452 5th to 8th grade students were screened, 210 from the upper 15 percentiles of blood pressure distribution (105 boys, 105 girls) were randomly assigned to one of three groups: low sodium diet (70 mmol sodium intake per day), potassium chloride supplementation (normal diet plus 1 mmol/kg potassium chloride per day), or placebo (normal diet plus placebo capsule). Capsules for the potassium chloride and placebo groups were administered in a double blind protocol. Blood pressure was measured every 3 months for 3 years. The effect of the intervention was determined by comparing the rate of rise (slope) of blood pressure among the groups using a random-coefficient growth curve model. The boys groups and the girls placebo group had similar positive blood pressure slopes that were significantly different from zero. The girls low sodium group had a slightly negative slope (significantly lower than the slope of the girls placebo group), and the girls potassium group had a slightly positive slope. Both of these slopes were not significantly different from zero and were significantly lower than the slopes of the respective boys groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Improvement in Long-Term Survival among Patients Hospitalized with Acute Myocardial Infarction, 1970 to 1980

The mortality rate associated with coronary heart disease in the United States has declined steadily since 1968, but the reasons for this favorable trend have not been completely elucidated. In particular, it is not clear to what extent the decline reflects decreasing incidence as opposed to improved survival. To assess whether improved survival after myocardial infarction has contributed to the decline, the Minnesota Heart Survey compared the four-year survival rate in patients discharged with a diagnosis of acute myocardial infarction from hospitals in the Twin Cities area in 1970 and 1980. After adjustment for clinical characteristics related to outcome, the survival rate among patients with a definite myocardial infarction was significantly higher in the 1980 than in the 1970 group. The four-year survival for men was 35 percent better in the 1980 than in the 1970 group (95 percent confidence interval, 21 to 50 percent), and for women it was 27 percent better (95 percent confidence interval, 1 to 46 percent). Improvement in survival during the period of hospitalization accounted for 70 percent of the overall gain in survival between 1970 and 1980 in men and for virtually all of the gain in women. We conclude that improved long-term survival among patients with acute myocardial infarction has made an important contribution to the decline in mortality from coronary disease.

A Comparative Study of the Effects of Dentinal Bonding Agents and Application Techniques on Marginal Gaps in Class V Cavities

The effectiveness of eight dentinal bonding agents (DBAs) and four of their combinations in eliminating marginal gaps in class V cavities was evaluated by the bulk method of composite application and two different incrementation techniques. The cavities were prepared one-half in enamel and one-half in dentin. Basic fuchsin 0.5% in propylene glycol was used for detection of the presence of gaps. For each cavity, the presence of gaps was scored as 0 or 1, at five enamel and five dentin locations. Marginal gaps were present in 6% of all enamel locations and in 75% of all dentin locations investigated. The gap frequency was lowest at the enamel occlusal locations, it increased gradually toward the dentin, and attained the highest value at the gingival locations. In enamel, the occurrence of gaps was dependent on the DBAs but independent of the particular technique used. In dentin, there was significant difference in gap occurrence between DBAs with any of the incrementation techniques. The frequency of gap occurrence was not significantly changed by the incrementation techniques. The most effective single agent in producing gap-free restorations was the Gluma, and the most effective combination was the GlumalClearfil.

Clinical staging system for cancer of the salivary gland: a retrospective study.

A comprehensive retrospective study of 861 patients with cancer of the salivary glands from 12 U. S. and Canadian participating institutions was carried out, and a TNM classification system is proposed for the staging of salivary gland cancer. This involves use of five clinical variables: size and local extension of the primary tumor, palpability and suspicion of the regional lymph nodes, and the presence or absence of distant metastases. We recommend its use for the staging of this cancer.

Renal preservation after warm ischemia using oxygen free radical scavengers to prevent reperfusion injury

Oxygen free radicals damage kidneys and accumulate during the period of preservation prior to transplantation. We hypothesized that a perfusate containing either an oxygen free radical scavenger such as ceruloplasmin, or an iron-chelating agent such as deferoxamine, would improve kidney preservation. Thirty-eight mongrel dogs underwent autotransplantation of the left kidney after 30 min of warm ischemia and 48 hr of machine perfusion (MOX-100, Water Instruments, Rochester, MN) at 5 degrees C and pH of 7.4. The right kidney was removed at the time of autotransplantation. Four blind code-labeled preservation solutions were tested. SGF-I was used for the control group (Group 1, n = 13), and the remaining animals were transplanted with kidneys preserved with one of three solutions modified from the basic SGF-I solution: Group 2, SGF-I plus deferoxamine (656 mg/liter), n = 8; Group 3, SGF-I ceruloplasmin enriched (72 mg/dl), n = 8; and Group 4, SGF-I ceruloplasmin reduced (3.4 mg/dl), n = 9. Serum creatinine levels were measured daily for 2 weeks and survival curves for each of the four groups were estimated by the Kaplan-Meier method. Peak mean serum creatinine levels +/- standard errors in Groups 1 through 4 were 12.6 +/- 1.97, 7.8 +/- 0.90, 7.1 +/- 1.26, and 8.2 +/- 1.09, respectively. Repeated measures analysis of variance showed statistically significant differences between the groups with respect to their serum creatinine profiles (Walds test x2 with 3 df = 22.39, P value less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Acute stroke in a metropolitan area 1970 and 1980. The Minnesota heart survey

Mortality rates for stroke, and hospitalization and case fatality rates for acute stroke in 1970 and 1980 were obtained for residents aged 30-74 of the Twin Cities (Minneapolis--St Paul) metropolitan area to determine whether improved hospital care contributed to the decline in stroke mortality. Age-adjusted mortality rates per 100,000 declined significantly in that decade for men (1970, 89.4; 1980, 47.5; p less than 0.01) and women (1970, 72.6; 1980, 40.9; p less than 0.01). Age-adjusted hospitalization rates per 100,000 population also declined significantly for men (1970, 438; 1980, 323; p less than 0.01) and women (1970, 331; 1980, 203; p less than 0.01). Age-adjusted mean length of hospital stay did not change significantly. Hospital case fatality declined for men aged 30-64 years (1970, 22.5%; 1980, 15.1%; p less than 0.01) but did not change significantly for 65 to 74 year-old men (1970, 16.5%; 1980, 20.0%; p = 0.09) or for all women (age-adjusted rates: 1970, 13.6%; 1980, 16.0%; p = 0.17). There was no change in the distribution of severity of hospitalized cases between years. Therefore, the decline in stroke mortality is consistent with a decreased incidence of stroke resulting from improved hypertension control. Improvements in hospital medical care appear not to have contributed substantially to the decline in stroke mortality.

Bond strengths of etched base metals: Effects of errors in surface area estimation

T he technique of bonding electrolytically etched, cast base metal retainers to acid-etched enamel with resin cements has recently been introduced as a conservative method for replacing missing teeth in selected situations.’ Electrolytic etching of base metal alloys creates a relief pattern that improves the retention of resins applied to metal surfaces in the same manner that acid etching improves the resin bond to enamel surfaces. The metals used for this technique are base metal alloys that may be categorized as beryllium-containing nickel-chromium (Ni-Cr) alloys, nonberyllium Ni-Cr alloys, or cobalt-chromium (Co-Cr) alloys. Acid types, concentrations, etching times, and current densities have been recommended by manufacturers and investigators.2’x Zidan” found that different base metal alloys etched under the different recommended etching conditions yielded different bond strengths. The framework for the retainers used in the etched, cast metal, resin-bonded prosthesis will vary in geometric configuration and consequently surface area. Calculation of the current density setting for attaining an optimal etch and therefore maximum retention of the metal framework is based on the surface area of the framework.‘” No convenient method presently exists for accurately determining the surface area of the framework, and an estimate of surface area must be relied on to determine the current density setting. Since an infinite variety of shapes and surface areas of retainers is possible for each clinical situation, the introduction of errors in the calculation of the milliamperage is inevitable. The purpose of this study was to investigate the effect of errors in estimating the surface area on the bond strength of eight base metal alloys used for the etched, cast metal, resin-bonded technique. Another objective was to compare these values with the mean bond strengths reported by Zidan’ for the same metals etched as recommended.