Systolic Hypertension in the Elderly Program (SHEP). Part 7: Baseline laboratory characteristics.
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Aged↗
Biomedical subjects
B R Davis
Publications and source records attributed to B R Davis.
Systolic Hypertension in the Elderly Program (SHEP). Part 1: Rationale and design.
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Health Policy↗
Pharmacologic and nutritional treatment of mild hypertension: changes in cardiovascular risk status.
OBJECTIVE: To evaluate the 6-month change in cardiovascular (coronary heart disease) risk as a function of diet and drug therapy for mild hypertension. DESIGN: Collaborative randomized, controlled clinical trial to assess the efficacy of alternative regimens in treating mild hypertension. SETTING: Three university-based tertiary care centers-the Trial of Antihypertensive Interventions and Management (TAIM). PATIENTS: Six hundred and ninety-two men and women ages 21 to 65 years with diastolic blood pressure between 90 and 100 mm Hg and weight between 110% and 160% of ideal weight. MEASUREMENTS AND MAIN RESULTS: Patients stratified by clinical center and race were randomized into diet (usual, low sodium-high potassium, weight loss) and drug (placebo, chlorthalidone, and atenolol) groups resulting in nine diet plus drug combinations. The cardiovascular risk at 6-month follow-up was estimated relative to baseline in 692 participants using the Framingham Study model. Due to the blood pressure reduction, cardiovascular risk declined from baseline for all treatment groups (except the usual diet plus chlorthalidone group because of increased cholesterol levels). The relative cardiovascular risk at 6 months compared to baseline ranged from 0.83 in the weight loss plus atenolol subgroup to 1.03 in the usual diet plus chlorthalidone subgroup. The active drug plus weight loss groups showed the lowest relative cardiovascular risk at 6 months. CONCLUSIONS: Mild hypertension was generally reduced to desirable levels within 6 months by monotherapy. Evaluating blood pressure changes together with the risk factors indicated a differential effect on overall cardiovascular risk depending on the diet and drug used. Dietary therapy, particularly weight reduction, was important adjunctive treatment in reducing overall cardiovascular risk.
Adrenergic beta-Antagonists↗
Analysis of shear wave propagation in skin; application to an experimental procedure.
An analysis of an experimental procedure used to determine age-related changes in the skin was performed. The experiment is based on the propagation of a shear wave through the skin. The analysis of the experiment was used to determine the effects of parameters such as properties of the skin and subcutaneous fat, skin thickness and experimental conditions on the propagation. Computer simulations showed that at lower frequencies (less than 1000 Hz), measured results depended strongly on skin thickness, while at higher frequencies (2000 Hz) the results were relatively insensitive to both skin thickness and the properties of the subcutaneous fat. Results also depended upon the distance between the applied shear disturbance and the measurement point. The analysis suggests that higher frequency (2000 Hz) experimental results are more indicative of mechanical properties of skin than lower frequency (less than 1000 Hz) results.
Aging↗
Results of trials reporting a J-shaped relation between achieved blood pressure and incidence of coronary heart disease.
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Antihypertensive Agents↗
Liposomes modulate human immunodeficiency virus infectivity.
We have investigated the effects of the fusion of liposomes with human immunodeficiency virus type 1 (HIV-1LVA) on the ability of the virus to infect CD4+ and CD4- cells. Fluorescence dequenching measurements indicated that HIV-1 fuses with liposomes composed of either cardiolipin (CL) or N-[2,3-(dioleyloxy) propyl]-N,N,N-trimethyl ammonium chloride (DOTMA) but not appreciably with dioleoylphosphatidylcholine (DOPC) liposomes. Pre-incubation of HIV-1 with DOTMA liposomes enhanced virus production (measured by p24 gag antigen production in the culture medium and in situ) in CD4+ A3.01 and H9 cells in a concentration-dependent manner, but did not mediate the infection of the CD4- cell line, K562. Preincubation of HIV-1 with between 10 and 30 microM-DOTMA liposomes, and subsequent incubation with A3.01 cells, resulted in the production of about 30-fold greater levels of virus than controls. The presence of DOTMA liposomes during the incubation of A3.01 cells with HIV-1 enhanced the infectivity of the virus up to 90-fold compared to controls. Conversely, preincubation of HIV-1 with CL liposomes inhibited infection of A3.01 cells, dependent on the concentration of liposomes; DOPC liposomes did not alter the infectivity of the virus under any of the incubation conditions. Our results thus indicate that fusion of HIV-1 with liposomes alters the ability of the virus to infect its target cells.
CD4 Antigens↗
Preleukemic hematopoietic hyperplasia induced by Moloney murine leukemia virus is an indirect consequence of viral infection.
We previously showed that neonatal mice inoculated with Moloney murine leukemia virus (M-MuLV) exhibit a preleukemic state characterized by splenomegaly and increased numbers of hematopoietic progenitors. An M-MuLV variant with greatly reduced leukemogenic potential, Mo+PyF101 M-MuLV, does not generally induce this preleukemic state. In order to investigate the mechanism involved in M-MuLV induction of preleukemic hyperplasia, we tested the CFU-mixed myeloid and erythroid (CFUmix) from M-MuLV- and Mo+PyF101 M-MuLV-inoculated mice for the presence of virus by antibody staining and for the release of infectious virus. The majority of CFUmix colonies from both M-MuLV- and Mo+PyF101 M-MuLV-inoculated mice contained infectious virus even though M-MuLV-inoculated mice showed elevated levels of CFUmix while the Mo+PyF101 M-MuLV-inoculated mice did not. This indicates that direct infection of hematopoietic progenitors was not sufficient to induce hyperplasia. Rather, hematopoietic hyperplasia may result indirectly from infection of some other cell type.
Animals↗
Occupational physical activity and other risk factors for preterm birth among US Army primigravidas.
We examined the relation of occupational physical activity to the risk of preterm birth among US Army active-duty primigravidas between 1981 and 1984 using 604 cases (preterm deliveries; less than or equal to 37 weeks gestation) and 6,070 controls (term and post-term deliveries). Women employed in the highest physical activity levels had increased odds of preterm delivery ranging from 1.69 to 1.75. The relation was not changed by adjustment for the effects of age, marital status, socioeconomic status, or education. Missing data suggest cautious interpretation.
Adult↗
Effect of weight loss on thiazide produced erectile problems in men.
Thiazide-type diuretics frequently produce erectile dysfunction in men on a regular diet. However, men on a weight-loss diet have much less erectile dysfunction. Thiazide-type diuretics also produce erectile dysfunction in rats and interfere with normal copulation. The mechanism of the dysfunction and the favorable response to weight loss is unknown.
Animals↗
Trial of antihypertensive interventions and management. Design, methods, and selected baseline results.
The Trial of Antihypertensive Interventions and Management was a multicenter randomized, placebo-controlled trial designed to assess the effectiveness of various combinations of pharmacologic and dietary interventions in the treatment of mild hypertension (diastolic blood pressure 90-100 mmHg). The primary outcome was blood pressure change between baseline and 6 months. The study consisted of a 3 X 3 factorial design wherein participants were randomly allocated to nine drug-diet treatment groups. Drugs included placebo, diuretic, and beta-blocker. Diets were usual, weight loss, and low sodium/high potassium. The basic strategy was to address clinical questions of interest by comparing mean blood pressure changes of selected drug-diet combinations. This paper describes the study including experimental design, sample size considerations, statistical analysis, organizational structure, and baseline findings.
Adult↗
Age-dependent changes in the shear wave propagation through human skin.
We studied the potential use of the in vivo frequency response of human volar forearm skin as a means for evaluating skin age. The velocity and damping length of waves on the skin surface were correlated with chronological age. One hundred and fifty subjects from 1 to 95 years of age were studied. For the frequency spectrum from 800 to 2000 Hz, there was a linear correlation between the velocity of propagation and age. At 2000 Hz, the y intercept was 11.4 m/second and the slope was 0.245 m/second/year, r = 0.5500, p less than 1 x 10(-7). There was no correlation of velocity with sex, skin color, obesity, sun exposure, physical activity, or inpatient status.
Adolescent↗
Synthesis and biological evaluation of a monocyclic, fully functional analogue of compactin.
Compound 8, a monocyclic analogue of compactin, has been prepared and its efficacy as an inhibitor of 3-hydroxy-3-methylglutarylcoenzyme A reductase (HMGR) evaluated. The synthesis (Schemes I and II) requires seven steps starting with di-(-)-menthyl fumarate and employs the useful RR-phosphonate reagent 14 to attach the mevinic acid side chain to aldehyde 13. A molecular mechanics study shows that the preferred conformations of 18 (a model for compactin) and 19 (a model for 8) are nearly identical. Compound 8 inhibits HMGR with IC50 = 320 microM, compared to a corresponding value of 32 nM for the compactin ketone, 5. The factor of 10,000 difference in the two inhibitors corresponds to a difference in binding energy of 5.45 kcal mol-1, or 1.36 kcal mol-1 for each of the four carbons of 5 that are missing in analogue 8. This quantitative difference is consistent with the idea that the decalin moiety of the mevinic acids play a purely hydrophobic role in binding the inhibitors to the enzyme.
Chemical Phenomena↗
Stage at diagnosis of breast cancer. Comparison in a fee-for-service and health maintenance organization practice.
This study assessed the effectiveness of two types of health plans in the diagnosis of female breast cancer by comparing the clinical stage at final diagnosis. Data on 202 cases diagnosed over a 4-year period from May 1983 to May 1987 were abstracted from medical records. Of these, 133 (65.8%) used fee-for-service (FFS) and 69 (34.2%) used health maintenance organization (HMO) plans. The two groups differed significantly on age and employment status; the HMO cases were younger than the FFS cases and were more likely to be employed. HMO cases also were more likely to have had some tests and procedures, but the test results were similar. Other demographic, risk factor, behavioral, clinical, and laboratory findings did not differ significantly by health plan, suggesting a uniformity of characteristics and of service availability. Overall, there was no difference between the groups in clinical stage of breast cancer at final diagnosis. On age-specific tests, however, the 45 to 55 year age group showed a significant difference in the stage of breast cancer at diagnosis with a higher proportion of HMO cases diagnosed at stage 1 than FFS cases. In contrast, in the 20 to 44 year age group, there was a nonsignificant trend for more FFS than HMO cases to be diagnosed at stage 1. Results from this study suggest that when offered by one medical practice, both FFS and HMO plans may be equally effective in the detection of breast cancer.
Adult↗
The Systolic Hypertension in the Elderly Program (SHEP): an intervention trial on isolated systolic hypertension. SHEP Cooperative Research Group.
The Systolic Hypertension in the Elderly Program (SHEP) is a randomized double-blind placebo-controlled trial to determine if antihypertensive treatment of isolated systolic hypertension (ISH) [systolic blood pressure (SBP) greater than or equal to 160 mmHg, diastolic blood pressure (DBP) less than 90 mmHg] reduces the 5 year incidence of fatal and nonfatal stroke. Between March 1, 1985 and January 15, 1988, 4736 persons (target 4800) with ISH, age 60 years and over, were enrolled. Potential participants met blood pressure (BP) and age criteria. Those on antihypertensive medication prior to enrollment without documented diastolic hypertension had their medication tapered and discontinued, and then met BP criteria (33% of cohort). Stepped-care therapy with chlorthalidone and atenolol (alternative, reserpine) or matching placebos was initiated as first and second steps. At baseline the trial population was 43.1% male, 56.9% female; 13.9% black, 86.1% non-black. Also, the mean age was 71.6 years; the mean SBP was 170.3 mmHg and the mean DBP was 76.6 mmHg; 59.8% had codeable resting electrocardiographic abnormalities. The trial is now in follow-up phase with scheduled termination in 1991.
Aged↗
Filariases.
It is apparent that there are many similarities among the various filariae. Besides a common life cycle, with an arthropod vector and human hosts, there are similarities in the diseases that they produce. This clinical picture takes one of two main courses: (1) characteristic disease produced by the presence of adult nematodes in their target tissue, which distinguishes typical cases for each of the filariae, and (2) the systemic hypersensitivity reactions to the circulating microfilaria, which tend to be similar. The characteristic feature of Wuchereria bancrofti is genital disease with funiculitis and hydrocele and less often elephantiasis. For Brugia malayi it is elephantiasis of the distal leg or arm, usually leaving the knee or elbow uninvolved with normal contours. Brugia timori, restricted to just a few islands of Indonesia, produces elephantiasis similar to that of Brugia malayi, but with its characteristic descending lymphadenitis. Loa loa is best known for the Calabar swelling, or angioedema, that it produces, although other filariae can induce similar reactions. Both Loa loa and Dirofilaria tenuis cause macroscopic, subconjunctival eyeworms. Clinical disease from onchocerciasis takes four predominant forms: eye disease, lymphadenitis, subcutaneous nodules (onchocercomata), and a pruritic, hypopigmented, or hyperpigmented papular dermatitis.
Animals↗
Are 24 hours of ambulatory ECG monitoring necessary for a patient after infarction?
The Beta-Blocker Heart Attack Trial was a randomized clinical trial of propranolol versus placebo in 3837 patients after myocardial infarction. A 24 hour ambulatory ECG was obtained before therapy in 3290 patients 2 to 21 days after myocardial infarction. Sensitivity, specificity, positive and negative predictive values, and prevalence were calculated for four definitions of ventricular arrhythmia with either total or sudden death (death in less than 1 hour of observed symptoms) as an endpoint. These indexes were obtained using the first 1, 2, 4, 6, 12, and 24 hours plus a random hour, a random daytime hour, and a random nighttime hour of the 24-hour ECG of 1336 placebo patients. For both total death and sudden death, as the duration of monitoring increased, (1) prevalence increased, (2) sensitivity increased, (3) specificity decreased, (4) positive predictive value either changed very little or decreased, and (5) negative predictive value was high (greater than 90%) and increased slightly. None of the 3 random hours offered anything beyond the first hour. The Beta-Blocker Heart Attack Trial data, which were based on an average follow-up of 25 months, show that as the number of hours of ambulatory monitoring increase, the percentages of patients identified at risk or not at risk (the positive and negative predictive values) do not change much. Twenty-four hours of monitoring does not appear to be the optimal time duration for deciding whether to treat arrhythmias in patients after infarction.
Adult↗
Coffee consumption and serum cholesterol in the hypertension detection and follow-up program.
The relation between coffee consumption and serum cholesterol level was investigated in a group of 9,043 hypertensive adults who were in the Hypertension Detection and Follow-up Program. In this study, men and women aged 30-69 years at baseline (1973-1974) had their serum cholesterol level measured at the two-year examination (1975-1976). Information about coffee, tea, and cola consumption was also obtained at that time from a food frequency questionnaire. The relation of coffee consumption and serum cholesterol level with potentially confounding variables including age, race, sex, diuretic status, diastolic blood pressure, cigarette smoking, relative weight, physical activity, stress, and education level was examined. When these variables were entered into a multiple regression equation, a positive association with coffee consumption and serum cholesterol level (p less than 0.05) was present. There was no significant relation between serum cholesterol level and consumption of tea, cola, or decaffeinated coffee--the other major contributors of caffeine to the diet--or total caffeine intake. This study indicates a significant positive relation between coffee consumption and serum cholesterol level.
Adult↗
Treatment of cancer of the liver. Twenty years' experience with infusion and resection in 414 patients.
The factors influencing survival for patients with cancer of the liver were studied by reviewing the records of 414 patients operated on in a private oncology practice. Approximately half (47%) had colorectal metastasis; 17% had metastatic breast carcinoma, 14% had malignant hepatoma, 5% had metastatic melanoma, and the remainder had a variety of primary cancers. Eighty-two per cent of all patients had advanced liver disease when first diagnosed. One quarter of the patients had some type of resection; the remainder had abdominal exploration plus insertion of an infusion catheter into the hepatic artery. The postoperative mortality rate after liver resection for 108 patients was 6.5%. After resection, the most important prognostic factor influencing survival was the presence or absence of extrahepatic metastases. When possible, resection was by far the best treatment available, and the best results were seen in patients who had resection of a solitary lesion. For advanced disease, when resection was not possible, intra-arterial chemotherapy, primarily with 5-fluorouracil (5-FU), was associated with response rates of 36% for colorectal cancer, 45% for breast cancer, 13% for hepatocellular cancer, 12% for melanoma, and 14% for metastases from other primary sites. The patients who responded to infusion lived longer than those who did not respond. For example, at 18 months, 26% of the responders with colorectal cancer were alive, as were 50% of the responders with breast cancer and 40% of the responders with hepatocellular cancer. In contrast, at 18 months, there were no survivors among the nonresponders with colorectal, breast, or hepatocellular cancer. For those patients treated solely by infusion chemotherapy, the extent of disease in the liver was the most reliable factor in predicting the length of survival. However, very few patients treated in this manner lived longer than 3 years.
Aged↗