Site-specific associations of muscle thickness with bone mineral density in middle-aged and older men and women.

It is unknown whether age-related site-specific muscle loss is associated with areal bone mineral density (aBMD) in older adults. To examine the relationships between aBMD and whole-body muscle thickness distribution, 97 healthy adults (46 women and 51 men) aged 50-78 years volunteered. Total and appendicular lean soft tissue mass, aBMD of the lumbar spine (LS-aBMD) and femoral neck (FN-aBMD) were determined using dual-energy X-ray absorptiometry. Muscle thickness (MT) was measured by ultrasound at nine sites of the body (forearm, upper arm, trunk, upper leg, and lower leg). Relationships of each co-variate with aBMD were tested partialling out the effect of age. aBMD was not correlated with either MT of the trunk or anterior lower leg in either sex. In men, significant and relatively strong correlations were observed between anterior and posterior upper arms, posterior lower leg, and anterior upper leg MT and LS-aBMD or FN-aBMD. In women, significant correlations were observed between anterior and posterior upper legs, posterior lower leg, and anterior upper arm MT and FN-aBMD. LS-aBMD was only correlated with forearm and posterior upper leg MT in women. In conclusion, the site-specific association of MT and aBMD differs between sexes and may be associated with the participants' daily physical activity profile.

The use of letter communication for patients enrolled in a pharmacist managed anticoagulation clinic.

WHAT IS KNOWN AND OBJECTIVE: It is unknown how letter communication vs. telephone communication compares in terms of affecting outcomes in patients followed in a busy anticoagulation clinic. This study was performed to determine if sending letters to communicate laboratory results and future appointments with patients enrolled in a pharmacy managed anticoagulation clinic is an effective alternative to telephone communication. METHODS: A retrospective review of quality assurance data currently collected at our facility was performed. Data were analyzed 4 months before and 4 months after the implementation of the letter notification. Data on percent international normalized ratio (INR) in therapeutic range, missed laboratory draw frequency and major bleeding events were collected daily, compiled monthly and then compared between the telephone and letter groups. RESULTS: There was no statistical difference in the percentage of INRs that were within goal range before and after letter initiation. There was a slight increase in the percentage of INR laboratory draws that were missed after the implementation of the letters (23% vs. 26%, P = 0·002). There were more major bleeding events after letter initiation, but this did not reach statistical significance. Approximately 80% of the patients received letters as the method of communication in the letter group. WHAT IS NEW AND CONCLUSION: The use of letters to notify warfarin patients with laboratory results is an effective method of communication without adversely affecting patient outcomes.

Bone densitometry in assessment of bone mineral density.

Osteoporosis is a serious disease characterized by low bone mineral density. Osteoporosis affects 24 million people annually and may be responsible for devastating hip, wrist and spinal fractures. Bone mineral density is considered the best predictor for osteoporotic fracture. Progress has been made toward noninvasive assessment of bone mineral density to provide early diagnosis of osteoporosis. A variety of methods are used to assess bone mineral density. These methods are presented and dual energy X-ray absorptiometry is discussed in detail.

Achieving a healthy lifestyle among United States adults: a long way to go.

OBJECTIVE: The United States population has been advised to engage in various healthy lifestyle factors known to be associated with reduced morbidity and mortality from various chronic conditions. These include not smoking, adequate fruit and vegetable intake, adequate physical activity, and normal body weight. Little is known about the prevalence of United States adults who engage in all four of these behaviors, however. DESIGN: Cross-sectional analysis. SETTING: The third National Health and Nutrition Examination Survey (1988-1994). PARTICIPANTS: 16,176 participants aged > or = 21 years. MAIN OUTCOME MEASURES: Percentage of participants engaging in four healthy lifestyle factors. RESULTS: Overall, 6.8% of the US population engaged in all four healthy lifestyle factors. Women were more likely than men (P = .001), and Whites and participants of "other race or ethnicity" were more likely than African Americans and Mexican Americans to engage in all four healthy lifestyle factors. A significant positive educational gradient was also evident (P for linear trend <.001). The highest percentages of participants engaging in all four lifestyle factors occurred among men (15.8%) and women (18.4%) of "other" race who had at least 13 years of education. The lowest percentages were observed for White men (1.1%) and African-American women (0.9%) with little education. CONCLUSIONS: The small proportion of US adults engaging in four healthy lifestyle factors demonstrates the enormity of the task that awaits the public health community in persuading Americans to adopt a multidimensional healthy lifestyle.

Fibrinogen, fibrin and crosslinking in aging arterial thrombi.

The assumption that fibrin and crosslinked fibrin impart irreversibility to arterial thrombi is explored with procedure developed for measuring changes in platelet function, morphology and fibrinogen metabolism in aging occlusive thrombi, in which the condition of stasis is imposed uniformly. Arterial thrombi containing autologous (111)In labeled platelets were generated in vivo by bilateral mechanical injury of porcine carotid arteries. Vessels containing the platelet-rich thrombi were harvested and incubated intact (37 degrees C) for intervals ranging from 30 min to 12 h. The isolated vessels were then bisected and agitated in culture medium containing tick anticoagulant and hirudin for 60 min. Disaggregated platelets were evaluated for yield (from (111)In radioactivity) viability (dense body ATP secretion) and morphology (electron microscopy). Western analysis of fibrin(ogen) in thrombus extracts was performed using anti-fibrinogen Bbeta- and gamma-chain monoclonal antibodies for thrombi at each time point. A stable recovery of nearly 50% of platelets was observed during 12 h of thrombus aging. As thrombi aged, viability of disaggregated platelets gradually decreased with platelet necrosis the predominant feature beyond 6 h. By western analysis of thrombus extracts, nearly 50% of fibrinogen was cleaved to fibrin and extensively crosslinked within 30 min of injury with no evidence of fibrinolysis. With the exception of a declining proportion of gamma-monomer, these features remain relatively constant during 12 h of thrombus maturation. It is concluded that neither fibrin nor crosslinked fibrin are dominant factors imparting cohesion within platelet thrombi. Furthermore, under conditions of complete arterial occlusion imposed by this experimental design, there is no evidence of endogenous fibrinolysis.

Health insurance status and cardiovascular disease risk factors among 50-64-year-old U.S. women: findings from the Third National Health and Nutrition Examination Survey.

To examine the cardiovascular disease risk factors profile and use of preventive health services for cardiovascular disease among uninsured women aged 50-64 years, we studied data from the National Health and Nutrition Examination Survey III (NHANES III), conducted from 1988 to 1994. Insured women (n = 1308) and uninsured women (n = 303) had similar levels of blood pressure and lipids, but uninsured women were more likely to be current smokers, sedentary, and overweight and to consume less fiber, vitamin C, folate, calcium, and potassium than insured women. Compared with insured women, uninsured women were less likely to have had their blood pressure checked during the previous 6 months, to have had their cholesterol level checked, and to be aware of hypercholesterolemia. Insured women (24.9%) were three times more likely to use estrogen replacement therapy than uninsured women (7.9%). NHANES III data suggest that women without health insurance have a worse cardiovascular disease risk factor profile and use healthcare services less frequently than women with health insurance.

Grapefruit juice and the response to warfarin.

The effect if any of prepared frozen grapefruit juice on prothrombin times (PTs) in patients undergoing stabilized warfarin therapy was studied. Patients receiving low-intensity warfarin therapy (targeted International Normalized Ratio [INR], 2-3) who had two consecutive baseline PTs within 10% of each other were recruited. Patients who regularly consumed grapefruit juice or alcohol or who were taking drugs known to interact with grapefruit juice were excluded. A one-week supply of freshly prepared frozen grapefruit juice in individual 8-oz containers was given to all the subjects, who were told to drink the entire contents of on container three times a day for one week. PTs were measured and INRs calculated on the day before grapefruit juice ingestion began (day 0) and a days 2, 6, and 8. Ten men (mean age, 66 years) were enrolled; one withdrew because of diarrhea. Compliance in consuming the juice was reported to range from 85.7% to 100% among patients. There was no significant difference among PT or INR values over the course of the study in any of the nine subjects. Ingestion of grapefruit juice prepared from frozen concentrate did not change PTs in patients treated with warfarin.

On the role of selective attention in visual perception.

What is the role of selective attention in visual perception? Before answering this question, it is necessary to differentiate between attentional mechanisms that influence the identification of a stimulus from those that operate after perception is complete. Cognitive neuroscience techniques are particularly well suited to making this distinction because they allow different attentional mechanisms to be isolated in terms of timing and/or neuroanatomy. The present article describes the use of these techniques in differentiating between perceptual and postperceptual attentional mechanisms and then proposes a specific role of attention in visual perception. Specifically, attention is proposed to resolve ambiguities in neural coding that arise when multiple objects are processed simultaneously. Evidence for this hypothesis is provided by two experiments showing that attention-as measured electrophysiologically-is allocated to visual search targets only under conditions that would be expected to lead to ambiguous neural coding.

Bridging the gap between monkey neurophysiology and human perception: an ambiguity resolution theory of visual selective attention.

When the visual system must process multiple objects simultaneously, as in the visual search paradigm, the neural coding of individual objects can become ambiguous due to the visual system's extensive use of coarse coding and distributed representations. Here we propose that the primary role of visual selective attention within the ventral object recognition pathway is to resolve these ambiguities. We begin by reviewing previous studies of the effects of attention on neural responses in monkeys, which provide the basis for this hypothesis, and then describe a new set of experiments showing that similar attentional mechanisms operate in the human brain. In these new experiments, event-related potentials (ERPs) were recorded from normal human observers while they performed tasks analogous to those used previously in monkeys. The central finding was that an attention-related ERP wave called the "N2pc component" was present under the same conditions that led to attentional modulations of neural responses in monkey visual cortex. These human electrophysiological results provide a bridge between cognitive-level theories of visual attention and the behavior of individual neurons in visual cortex.

Lack of effect of fluoxetine on the hypoprothrombinemic response of warfarin.

The purpose of this study was to assess the effect of fluoxetine on the hypoprothrombinemic response of warfarin in patients chronically anticoagulated. Patients receiving low-intensity anticoagulation with warfarin were recruited. All patients were taking stable dosages of warfarin and had two baseline prothrombin times (PTs) within 10% of each other. Each patient received fluoxetine (20 mg daily) for 21 days. PTs were measured on days 2, 5, 8, 12, 15, 19, and 22 of fluoxetine administration. Six patients completed the study. There was no significant difference in mean PTs before and during fluoxetine administration. Fluoxetine at the dosage studied does not predictably effect the hypoprothrombinemic response of warfarin.

Low-dose fluconazole therapy potentiates the hypoprothrombinemic response of warfarin sodium.

BACKGROUND: Fluconazole has been reported to interact with many medications. This study examined the effect of low-dose fluconazole therapy on the hypoprothrombinemic response of warfarin sodium in patients. METHODS: Patients receiving low-intensity anticoagulation therapy with warfarin were recruited. All patients were taking stable doses of warfarin and had two baseline prothrombin times (PTs) within 10% of each other. Each patient received 100 mg of fluconazole daily for 7 days. Prothrombin times were measured on days 2, 5, and 8 during fluconazole administration. RESULTS: All patients had a progressive increase in PTs. Mean (+/- SD) of PTs increased from 15.8 +/- 1 seconds before the administration of fluconazole to 18.9 +/- 1.9 seconds on day 5 and 21.9 +/- 2.2 seconds on day 8. Fluconazole therapy was stopped early in the three patients due to high PTs. The largest change in PT was 9.7 seconds. No bleeding was noted during the study. CONCLUSION: Fluconazole predictably potentiates the hypoprothrombinemic response of warfarin. Prothrombin times must be monitored when fluconazole is administered to patients taking warfarin.

Delayed psyllium allergy in three nurses.

The use of psyllium has been associated with various allergic reactions. Three nurses at the Prescott Veterans Affairs Medical Center had differing degrees of psyllium allergy. The reactions ranged from sneezing to chest congestion and wheezing. Two nurses were available for skin testing, and both had a positive wheal reaction. Psyllium allergic reactions have been reported rarely in the literature; however, they may be more prevalent than previously realized.

Predicting survival after stroke: a three-year follow-up.

We examined characteristics associated with a high risk of mortality within 3 years after a stroke. Analyses are based on data from a population-based register of stroke events that occurred in Auckland (total population 829,545), New Zealand during a 1-year period in 1981-1982 and a 3-year follow-up study of all survivors (97% complete). Statistical techniques that allow for the simultaneous evaluation of multiple factors indicated that retention of consciousness, decreasing age, and place of residence at the onset of the stroke were the strongest predictors of survival over 3 years. The survival rate for those living at home at the onset of the stroke who did not lose consciousness was 58% compared with 5% for people in institutional care who lost consciousness. Marital status, history of stroke, and ethnic group also predicted survival. Most of the important prognostic factors we identified in our study cannot be modified, testifying to the importance of the prevention of stroke in the first place.

Underestimation of relative weight by use of self-reported height and weight.

Self-reported and measured height and weight were obtained from a representative sample of 1,598 persons in Auckland, New Zealand during 1982. The accuracy of the self-reported data and its effect on the misclassification of relative weight, as measured by Quetelet index, were examined. The finding that for most participants (75%), self-reported measures were no more than 3.5 cm from their measured height and 2.4 kg from their measured weight indicates that self-reports have a high degree of accuracy. However, the participants consistently overestimated their height and underestimated their weight, resulting in an underestimation of relative weight. This would have little effect on analyses using the self-reported relative weight measures as a continuous covariate, but misclassification would occur when using relative weight as a categorical variable. The sensitivities and specificities associated with categorized self-reported relative risks that have been calculated from relative weight derived from self-reported height and weight.