Diet and exercise profiles of 30- to 60-year-old male smokers: Implications for community heart health programs

The aim of this study was to estimate the prevalence of diet and exercise behaviors in middle-aged male smokers and identify their determinants of behaviors, with the ultimate goal of designing more effective interventions in a community heart health program. Self-administered, postal questionnaires produced a sample of n = 671 male smokers, 30 to 60 years of age residing in Laval, Quebec's second most populous city. Variables for the study were derived from the theory of planned behavior. Correspondence analysis explained 65% of the variance, classifying smokers into five groups based on diet and exercise behavior. Group 1, smokers with diet and exercise behaviors deemed inadequate for heart health, comprised 43% of the total. Groups 2 and 3, smokers with a diet deemed inadequate or needing improvement respectively, and Group 4, smokers with inadequate exercise, comprised 42% of the total. Group 5, smokers with neither of the other high-risk behaviors, comprised 15% of the total. Four significant variables contrasted Groups 1 to 4 with group 5∶ age, number of cigarettes smoked daily, and perceived behavioral control (PBC) in both diet and exercise. However, coefficients for age and smoking were weak for all groups. Coefficients for PBC in diet were high and negative only for smokers with an inadequate one. For PBC in exercise, they were high and negative only for smokers who exercised inadequately. Intervention groups based on specific deficiencies in diet and exercise behaviors were then identified. Therefore, the results suggest that smoking cessation programs may be made more effective by targeting specific sub-groups and by providing resources and opportunities to counteract the lack of perceived behavioral control in middle-aged male smokers vis-a-vis diet and exercise.     

Inhibition of heparin activity in plasma by soluble fibrin: evidence for ternary thrombin-fibrin-heparin complex formation

The ability of heparin to dramatically enhance the inactivation of thrombin (IIa) by antithrombin III (ATIII) in buffer is negated through formation of a IIa-fibrin-heparin ternary complex (Hogg and Jackson, Proc Natl Acad Sci USA 86:3619, 1989; Hogg and Jackson, J Biol Chem 265:241, 1990). IIa, in this ternary complex, is protected from inactivation by ATIII. Our aim was to determine whether fibrin also compromises heparin efficacy in plasma. We found that soluble fibrin ablated the heparin-mediated prolongation of the thrombin time with half-maximal effect at 60 nmol/L fibrin. The heparin-mediated prolongation of the activated partial thromboplastin time (APTT) was also reduced by fibrin with half-maximal effects at 140 nmol/L fibrin using 0.12 U/mL heparin and 500 nmol/L fibrin using 0.25 U/mL heparin. The mechanism of inhibition of heparin activity by fibrin in plasma was determined by measuring IIa-ATIII complexes by enzyme-linked immunosorbent assay (ELISA). Fibrin was found to inhibit the heparin- catalyzed inactivation of IIa by ATIII with half-maximal effect at 97 +/- 19 nmol/L fibrin. Fibrin had no effect on the heparin-catalyzed inactivation of factor Xa by ATIII in plasma, using either standard heparin, a heparinoid preparation (Orgaran; Organon, Lane Cove, Sydney, Australia), or low-molecular weight heparin. These findings imply that fibrin is a potent modulator of heparin activity in vivo by inhibiting heparin-catalyzed IIa-ATIII complex formation through formation of ternary IIa-fibrin-heparin complexes.     

Recurrent carotid artery stenosis following endarterectomy.

Spectral analysis was used to examine 257 carotid arteries in 227 patients who had undergone carotid endarterectomy at 1, 3, 6, and 12 months after surgery and annually thereafter. Routine intraoperative completion angiography ensured that the operations were technically satisfactory. Postoperative restenoses were identified in 38 patients (15%). In 23 arteries (9%), the restenosis exceeded a 50% diameter reduction while in 15 arteries (6%) the stenosis was less than 50% of the diameter. Restenosis developed in 24/96 women (25%) and 14/161 men (9%). Twenty-nine (70%) stenotic lesions occurred within 12 months. In three patients early lesions regressed. Reoperation with patch angio-plasty was required in six patients. When the 219 carotid arteries that remained widely patent were compared to the 38 that restenosed , no differences were noted for age, diabetes mellitus, hypertension, smoking, or degree of preoperative stenosis. Early stenotic lesions appear to be due to myointimal hyperplasia, which is probably platelet mediated. The predominant female sex distribution may be explained by differences in platelet responsiveness in men and women.     

Clinical evaluation of the intraoral fluoride releasing system in radiation-induced xerostomic subjects. Part 2: Phase I study

Radiation-induced xerostomia can result in the rapid onset and progression of dental caries in head and neck cancer patients. Topically applied fluorides have been successfully used to inhibit the formation of dental caries in this population. However, because intensive daily self-application is required, compliance is an issue. The intraoral fluoride-releasing system (IFRS) containing a sodium fluoride core is a newly developed, sustained-release, passive drug delivery system that does not require patient involvement except for periodic replacement, thus reducing the effect of patient compliance on its effectiveness in dental caries prevention. Twenty-two head and neck cancer patients from U. T. M. D. Anderson Cancer Center, with radiation-induced xerostomia, were entered into a pilot study to contrast the daily home use of a 0.4% stannous fluoride-gel-containing tray (control group) to IFRS (study group) with respect to tolerability and adherence, and to obtain information on relative caries preventive efficacy. Participants were stratified on the basis of radiation exposure and randomly assigned to treatment with either IFRS or stannous fluoride gel. Patients in both groups were fitted with two IFRS retainers and also were instructed to use a 1100-ppm fluoride conventional sodium fluoride dentifrice twice daily. The study was conducted as a single-blinded, parallel-cell trial. Pre-existing carious lesions were restored prior to the beginning of the study. The efficacy variable was determined by the mean number of new or recurrent decayed surfaces. Patients were examined for caries 4, 8, 12, 24, 36, and 48 weeks after initiation of treatment. Reports of adverse reactions were based on information volunteered by patients and that were elicited during interviews. At baseline, the resting and stimulated salivary flow rates (g/5min) were significantly greater in the control group than in the study group (p<0.05). Patients in the control group had received significantly more radiation than those in the test group (68Gy vs. 60Gy; p=0.047). No marked differences in follow-up new and recurrent caries were found between the stannous fluoride gel control and IFRS groups during the study period. The rate of new or recurrent carious lesions in the group treated with the fluoride gel was slightly lower than in the IFRS group, based on carious lesions at the baseline examination (Poisson mean number of new or recurrent carious lesions for the control group=0.55 per year vs. 0.83 per year for the study group, p=0.705; odds ratio of the occurrence of any new or recurrent caries during follow-up for control group vs. the study group=0.80; p=0.781). This pilot study revealed that the IFRS was well-tolerated and safe in this study population associated with minimal complications during the duration of this study and was comparable in efficacy to a SnF(2) gel in preventing caries development. The IFRS provided similar rates of control for caries formation to a fluoride-gel-containing tray. The IFRS is designed to release a daily dose of 0.12mg of sodium fluoride, which can be evenly distributed throughout the oral cavity for a single application of 4 months. It would be more convenient than the daily home application of a tray of 0.4% stannous fluoride or 1.1% sodium fluoride gel, and avoids the problem of variable patient compliance.     

Anteroposterior tibiofemoral displacements during isometric extension efforts. The roles of external load and knee flexion angle

Rehabilitation of knee extensors is a major consideration in patients with cruciate injuries and repairs. Extension exercises, however, can produce undesirable loads on the injured or replaced anterior cruciate ligament (ACL) resulting in permanent stretch of this restraint. Our study measures the tibiofemoral displacements associated with proximal, middle, and distal locations of the external resisting force and knee flexion angles of 30 degrees, 60 degrees, and 90 degrees. Our results show that tibiofemoral displacements are dependent on both location of the external resisting force and knee flexion angle, with anterior displacements being associated with distal displacement of the resistance pad. The results suggest that patients with ACL injuries or repairs conduct extension exercises with a proximal position of the resistance pad to minimize loads and prevent stretching of this constraint.     

Transfer of nongenetic thermostability from genetically thermostable to genetically thermolabile poliovirus

Summary Adding the genetically thermostablecr ⁱ mutant of the Akron strain of type 1 poliovirus to the genetically thermolabile Akronca ³⁰ mutant before infection of monkey kidney tissue culture sheets resulted in an average 17-fold increase in the heat-surviving fraction of theca ³⁰ virus progeny. Mixing the 2 viruses after infection did not result in any increase. The progenies of at least most of these thermostable transferee particles were thermolabile. By this criterion the transferred thermostability was at least mainly nongenetic.Aided by grant from National Foundation.