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Biomedical subjects

B Marcus

Publications and source records attributed to B Marcus.

At least 19 recordsLinked to original sources
PubMed2001

Relationships of physical activity with dietary behaviors among adults.

BACKGROUND: Physical activity and diet are important influences on health, but few data are available about the relationship between these two factors. The purpose of this study was to examine relationships between physical activity and dietary quality and to identify determinants of the combination of sedentary behavior and suboptimal diet. METHODS: The design of this study was cross-sectional. The setting was a large managed-care organization and the participants were 1,322 racially diverse men and women ages 25-91 years. We categorized subjects' physical activity into vigorous, moderate, and sedentary based on answers to two validated interviewer-administered questions about intensity and duration of specified activities. Dietary assessment was by means of a validated short food frequency questionnaire. We defined suboptimal diet as consuming unhealthful quantities of at least two of the following five food groups: fruits, vegetables, whole grain foods, whole-fat dairy foods, and red and processed meats. RESULTS: Seven hundred fifty-four (57%) subjects were sedentary and 617 (47%) consumed a suboptimal diet. Using multiple linear regression, we found that sedentary individuals consumed smaller amounts of foods and nutrients considered to be healthful, such as fruits and vegetables, fiber, calcium, folate, and vitamins A, C, and E, than more active participants. For nutrients considered to be harmful, such as saturated fat, trans fat, and dietary cholesterol, the association with physical activity was inverse. In multiple logistic regression analyses, the strongest sociodemographic correlates of the joint presence of inactivity and poor diet were less education [odds ratio for 1-year decrease 1.14 (95% confidence interval 1.06, 1.22)], nonwhite race [1.48 (1.05, 2.07)], and nonmarried status [1.49 (1.06, 2.10)]. CONCLUSIONS: Physical activity and diet quality are correlated behaviors. Suboptimal diet and sedentary behavior tend to cluster in individuals who are less educated, not married, and of nonwhite race. Programs that target diet and activity together, informed by their joint determinants, may attain enhanced outcomes.

Adult↗
PubMed2000

Incorporating physical activity advice into primary care: physician-delivered advice within the activity counseling trial.

INTRODUCTION: The Activity Counseling Trial (ACT) was designed to compare the effectiveness of physician advice alone with physician advice plus behavioral counseling, provided by ACT-trained health educators, to increase levels of physical activity in healthy, sedentary patients. The objective was to determine health care providers' adherence to the ACT protocol for delivering initial "physician" advice on physical activity and to determine providers' satisfaction with the protocol. METHODS: Fifty-four physicians or physician assistants from 11 primary care practices located in California, Texas, and Tennessee volunteered to participate as ACT-trained physicians. Providers were trained to integrate 3 to 4 minutes of initial physical activity advice into the routine office visits of sedentary patients, aged 35 to 75 years, with no acute or serious chronic conditions. This advice included assessment of current physical activities, advising the patient about an appropriate physical activity goal, and referring the patient to the health educator. Providers initialed forms to document delivery of advice, and ACT health educators recorded their advice on a computerized tracking system. A provider survey measured length of time spent advising patients about physical activity and provider satisfaction with the program. RESULTS: Ninety-nine percent of patients received the initial physician advice about physical activity. Eighty-three percent of the providers spent less than 5 to 6 minutes, and 46% spent the recommended 3 to 4 minutes providing advice. Sixty-three percent said the advice resulted in little or no increase in the length of an office visit, and 83% said participation was an asset to their clinics. CONCLUSIONS: Providers incorporated brief physical activity advice into routine primary care visits with little disruption. Their response to the ACT advice protocol was positive and participation in the study was viewed as beneficial.

Adult↗
PubMed1999

Lipid reactivity to stress: II. Biological and behavioral influences.

This study examined behavioral and physiological influences on lipid concentrations during acute and chronic stressors. One hundred men (n = 92) and women (n = 8) were tested during a chronic stressor and during 2 acute stressors. During chronic stress, diet, physical activity, exercise, and sleep were examined. During the acute stressors, catecholamines, cortisol, plasma volume, and cardiovascular responses were examined. None of the behavioral influences could explain the lipid response to chronic stress. Responses of the atherogenic lipids to acute stressors were not solely reflecting hemoconcentration of the plasma but were moderately correlated with cardiovascular, epinephrine, and cortisol reactivity. Diastolic blood pressure reactors to the acute stressors had larger lipid responses to the chronic stressor than did nonreactors. Elevations in blood lipids during stress are not artifacts and may be clinically significant.

Acute Disease↗
PubMed1999

The Working Healthy Project: a worksite health-promotion trial targeting physical activity, diet, and smoking.

Worksites are a key channel for delivery of interventions designed to reduce chronic disease among adult populations. Although some evaluations of worksite physical-activity interventions have been conducted, to date very few randomized trials of worksite health promotion have included the goal of increasing physical-activity levels as part of a comprehensive multiple risk factor approach to worksite health promotion. This article presents the results regarding behavior change found among the cohort of 2055 individuals who completed three health-behavior assessments as part of their worksites' participation in The Working Healthy Project (WHP), a multiple risk factor intervention implemented in 26 manufacturing worksites. In this study, a randomized matched-pair design was used. Fifty-one percent (n = 2,761) of the employees who completed the baseline assessment also completed the interim survey. Eighty-three percent of those who completed the interim assessment also completed the final survey. The WHP intervention targeted smoking, nutrition, and physical activity. At baseline, 38% of the sample reported engaging in regular exercise, and subjects reported consuming an average of 2.7 servings of fruits and vegetables per day, 7.9 grams of fiber per 1000 kilocalories, and 35.4% calories from fat per day; 28% of the sample were smokers. By the time of both the interim (intervention midpoint) and final (end of intervention) assessments, participants in the intervention condition had significantly increased their exercise behavior, compared with the control condition. There was also increased consumption of fruits and vegetables and fiber in the intervention condition by the time of the final assessment, compared with the control condition. No differences by condition were found with regard to percentage of calories from fat consumed or smoking cessation. These results suggest that among a cohort of participants in a worksite health promotion study, there were significant health behavior changes across two risk factors over time. These data suggest that further investigation of multiple risk factor worksite health promotion is warranted, particularly with a focus on ways to increase participation in these programs and to diffuse intervention effects throughout the entire workforce.

Adult↗
PubMed1998

Exercise, smoking cessation, and short-term changes in serum lipids in women: a preliminary investigation.

PURPOSE: This study investigated the combined effects of exercise and smoking cessation on serum lipids. METHODS: Eighteen female smokers quit smoking using standard behavioral methods combined with exercise (N = 9) or with a nonexercise contact time control (N = 9). The smoking cessation program for both groups consisted of 12 weekly 1-h behavioral modification sessions held over 12 wk. Exercise training consisted of three supervised 45-min sessions per week for 12 wk. Contact control consisted of three health education lectures/discussions per week for 12 wk. Fitness (estimated VO2 peak), dietary variables, and fasting serum lipids and lipoproteins were assessed before and at the end of treatment. VO2 peak increased in the exercise subjects compared with the controls. RESULTS: Total caloric intake as well as total fat and carbohydrate increased significantly after smoking cessation in the controls, but there were no dietary changes in the exercise group. high density lipoprotein (HDL)-C2 increased (7.6 mg x dL(-1), P < 0.01) in the exercise group, whereas the increases in HDL and its subfractions did not attain statistical significance in the contact control group. Total cholesterol, low density lipoprotein (LDL)-C, and triglycerides did not change in either group. CONCLUSIONS: We conclude that exercise training magnifies the increase in HDL-C that usually occurs with smoking cessation.

Adult↗
PubMed1997

Value of a supervised exercise program for the therapy of arterial claudication.

PURPOSE: This study was performed to test the effectiveness of a formal supervised exercise program against a home-based exercise program for both walking ability and quality of life endpoints. METHODS: Patients with arterial claudication were randomized to either a 12-week supervised exercise program (SUPEX) with weekly lectures relating to peripheral vascular disease or to a home exercise group (HOMEX) who attended an identical lecture program and received weekly exercise instruction. The study population included 29 men and 26 women, with a mean age of 69.1 +/- 8.1 years. Forty-seven patients completed the 12-week program, 46 were available for testing at completion, and 38 for 6-month testing. Claudication pain time (CPT) and maximum walking time (MWT) on a progressive treadmill exercise test were assessed at baseline, program completion, and 6 months. The Medical Outcomes Study Short Form-36 (SF-36) was administered at these intervals to assess effects on quality of life. RESULTS: Each group improved (p < 0.001) in both CPT and MWT at the completion of the 12-week program, which was sustained at the 6-month follow-up. Increase in HOMEX CPT from baseline (3.6 +/- 2.73 minutes) to 6-month follow-up (6.6 +/- 3.17 minutes) was less than for the SUPEX group (3.8 +/- 2.74 to 11.2 +/- 4.02 minutes, respectively); similar results were obtained for MWT. At both completion and 6 months, there was a significant intergroup difference for CPT and MWT (p < 0.004) favoring SUPEX. For both groups, measures of health perception based on the SF-36 demonstrated improvement (p < 0.002) in Physical Function Subscale, Bodily Pain Subscale, and Physical Composite Score. There were no between-group differences on the subsets of the SF-36 at the three assessment intervals. CONCLUSIONS: Supervised exercise programs provide superior increased walking ability in the noninterventional therapy of arterial claudication, and both supervised and home based exercise therapy result in improved SF-36 functional measures. The lack of intergroup differences in these measures may be a result of the high degree of interaction with healthcare providers in the HOMEX group. Although a supervised program results in optimal walking benefits, a highly structured home-based program provides similar functional improvement and may be a satisfactory alternative for patients with lesser walking requirements.

Aged↗
PubMed1995

The domain of p53 required for binding HPV 16 E6 is separable from the degradation domain.

The E6 proteins of specific cancer-associated human papillomaviruses (HPVs) complex with and mediate degradation of the cellular anti-oncogene p53 in vitro. A critical property of p53 is its ability to stimulate transcription from promoters containing its recognition sequence. HPV E6, mutant p53 proteins, and several DNA tumor virus oncogenes inhibit the transcriptional activity of wild-type p53. In this report, the structural requirements for the interaction between HPV 16 E6 and p53 were examined both in vivo and in vitro. p53-stimulated transcription was efficiently inhibited by wild-type HPV 16 E6 and E6 mutants competent for p53 binding and degradation. A series of p53 deletions and hybrid proteins with heterologous DNA binding, dimerization and transactivation domains were analysed for transcriptional interaction with HPV 16 E6 to determine the domains of p53 required for transcriptional inhibition. These chimeric proteins were also analysed for E6 binding and E6-mediated degradation in vitro. In both assays, complex formation with E6 was mediated through the amino-terminal 345 amino acids of p53 without a specific requirement for its C-terminus. Hybrid proteins containing residues 161-345 of p53 also bound E6, but this segment of p53 was not susceptible to E6 induced proteolysis. A second region of p53, within its N-terminal 160 aa, is required for E6 induced degradation of complexed p53. Taken together, these results suggest that the complex formation between E6 and p53 is not mediated through the C-terminus of p53 and that binding and degradation are separable.

Animals↗
PubMed1995

Simultaneous assessment of cell kinetics and programmed cell death in bone marrow biopsies of myelodysplastics reveals extensive apoptosis as the probable basis for ineffective hematopoiesis.

Despite hypercellular bone marrows (BM), peripheral cytopenias are the rule in patients with myelodysplastic syndromes (MDS). This study examined the roles played by cell birth and cell death rates in generating this paradox. Cell kinetics from BM biopsies of 35 MDS patients were measured using intravenous infusions of either iododeoxyuridine or bromodeoxyuridine, or both. Degree of apoptosis or programmed cell death (PCD) was estimated using in situ end-labeling of DNA directly from BM biopsies, which were simultaneously double-labeled from proliferation/PCD. MDS were found to be highly proliferative disorders with large numbers of myeloid, erythroid, and megakaryocytic cells synthesizing DNA. Median cycling time (Tc) of myeloblasts was more rapid than that of patients with acute myeloid leukemia (44.1 hr vs. 56.0 hr). Interestingly, most marrow cells of all three lineages in 32 of 34 evaluable cases were undergoing PCD. In 19 of 32 patients, greater than 75% cells were apoptotic. Surprisingly, large numbers of S-phase cells were found to be simultaneously undergoing PCD, as were stromal cells of the BM microenvironment. We conclude that the extensive apoptosis in hematopoietic cells effectively cancels the high birth rate resulting in ineffective hematopoiesis and accounting for deficient bone marrow function.

Acute Disease↗
PubMed1995

Successful use of transesophageal echocardiography during extracorporeal membrane oxygenation in infants after cardiac operations.

We report the use of transesophageal echocardiography in infants after cardiac operations while supported on extracorporeal membrane oxygenation. In all patients transesophageal echocardiography provided valuable information when standard transthoracic echocardiographic evaluation was limited by poor acoustic windows. This report describes the application of transesophageal echocardiography during extracorporeal membrane oxygenation after cardiac operations.

Cardiac Surgical Procedures↗
PubMed1995

A multivariate study of non Hodgkin's lymphoma involving proliferation, apoptosis, bcl-2 and the microenvironment.

The study was carried out on 22 patients with non-Hodgkin's lymphoma (NHL) who had received sequential infusions of two thymidine analogues iododeoxyuridine (IUdR) and bromodeoxyuridine (BrdU). Cell cycle kinetic studies seemed to differentiate distinctly between low grade lymphoma (n = 8, LI = 2.6%) compared to that of intermediate grade (n = 9, LI = 13%, p = 0.0001) and high grade NHL (n = 5, LI = 16.3%, p = 0.0062). While the majority of 14 intermediate and high grade lymphomas had a high labeling index there were 3/14 patients with a LI of 5.5%, 5.5% and 4.1% respectively. A decrease in the rate of programmed cell death (PCD) or apoptosis due to the overexpression of bcl-2 has been implicated as the possible pathogenesis for follicular lymphoma. We determined the presence of bcl-2 protein immunohistochemically and apoptosis by in situ end labeling of DNA which detects cells in early stages of PCD not recognized morphologically. Nine NHL patients demonstrated PCD ranging from 1%-40%, while it was undetectable in 13/22 patients. Of these 13 cases, 6 showed the presence of bcl-2 expression. To understand the relationship of the microenvironment to the lymphoma cells, the presence of transforming growth factor beta (TGF-beta) was determined immunohistochemically. TGF-beta was present in all the cases where bcl-2 was present, except one. This study highlights some of the key biological features of NHL cells and their microenvironment.

Apoptosis↗
PubMed1994

Transesophageal echocardiography in the postoperative child with an open sternum.

We report the use of transesophageal echocardiography in 3 children whose sternums remained open for several days postoperatively. In these patients transesophageal echocardiography provided critical information when transthoracic echocardiography was ineffective due to limited acoustic windows. This report points out the application of transesophageal echocardiography in children with chest wall distortion.

Cardiac Tamponade↗
PubMed1994

Novel in situ double labeling for simultaneous detection of proliferation and apoptosis.

We describe a novel double-labeling method to simultaneously investigate proliferation and apoptosis from plastic-embedded biopsy specimens (PEBs). Infusions of bromo- and/or iododeoxyuridine (BrdU/IudR) were given to 10 patients, five with acute myeloid leukemia (AML) and five with myelodysplastic syndromes (MDS), and S-phase cells were measured in PEBs using a monoclonal anti-IudR/BrdU antibody. Apoptosis was measured by in situ end-labeling (ISEL) of DNA. The results demonstrate that both AML and MDS are highly proliferative disorders but that there is almost no apoptosis in the former, whereas extensive apoptosis was observed in the latter. Double labeling revealed that large numbers of S-phase cells in MDS were simultaneously undergoing apoptosis. We conclude that the high cell death in MDS cancels the high cell birth, resulting in a functionally aplastic marrow and thus accounting for the observed ineffective hematopoiesis. On the other hand, AML is rapidly fatal, probably owing to high cell birth with no or minimal cell death. Therapeutic strategies to prevent intramedullary programmed cell death of hematopoietic precursors should be evaluated in MDS, and efficacy of chemotherapy in AML can be assessed by measuring the induction of apoptosis in post-treatment biopsy specimens.

Acute Disease↗
PubMed1991

Electrophysiologic evaluation of sinus node dysfunction in postoperative children and young adults utilizing combined autonomic blockade.

Sinus node dysfunction is a recognized problem following surgery for congenital heart disease. Seven postoperative patients with sinus node dysfunction (5 Mustard, 1 tetralogy of Fallot, 1 Fontan) underwent electrophysiology study of sinus node function during combined autonomic blockade (CAB) utilizing propranolol 0.2 mg/kg i.v. and atropine 0.04 mg/kg i.v. to evaluate intrinsic sinus node function isolated from autonomic control. During CAB, intrinsic heart rate, intrinsic corrected sinus node recovery time, and intrinsic sinoatrial recovery time were measured. These results were compared with age-matched normal intrinsic data from our lab [normal (n = 7, mean age 9 years) IHR 128 +/- 24, intrinsic corrected sinus node recovery time 135 +/- 40 ms, intrinsic sinoatrial conduction time 86 +/- 19 ms]. Among postoperative Mustard patients (n = 5, mean age 13 years, mean years postoperative 11) 2 of 5 had clearly abnormal intrinsic sinus node function with nonsinus rhythm during CAB; 3 of 5 had sinus rhythm during CAB with normal or mildly abnormal intrinsic sinus node function. The postoperative case of tetralogy of Fallot (age 20 years, postoperative 14 years) had mildly abnormal intrinsic sinus node electrophysiology study. The postoperative case of Fontan (age 16 years, postoperative 1.5 years) had sinus rhythm at rest but left atrial rhythm during CAB. Different aspects of sinus node dysfunction may be expressed during resting electrophysiology study vs. electrophysiology study utilizing CAB. The pathophysiology of sinus node dysfunction among postoperative pediatric patients is not homogeneous with regard to the contribution of intrinsic sinus node dysfunction. In those patients with normal or mildly abnormal intrinsic sinus node function, an important pathophysiologic influence of the autonomic nervous system is implicated.

Adolescent↗
PubMed1991

A new model for objective assessment of cervical ripening: the effect of prostaglandin E2 and prelabor contractility.

A rabbit cervix preparation designed to evaluate the effects of locally administered substances and those of prelabor contractility on cervical ripening is described. In one experiment, one of the two cervices was exposed to prostaglandin E2 gel and the contralateral cervix was exposed to plain gel. In another experiment, one cervix was completely isolated from prelabor contractility, whereas the contralateral cervix remained intact. Cervical ripening was assessed by measurement of the stretch modulus and rate of creep 2 days later. Treatment with prostaglandin E2 gel and exposure to prelabor contractility resulted in significant unilateral cervical changes, suggesting that at least part of the prostaglandin E2 effect is locally mediated and that spontaneous prelabor contractility may play a role in cervical preparation for labor. Furthermore, because of its simplicity, this animal preparation can be useful in the investigation of the effects of other locally administered substances on cervical ripening.

Animals↗