Risk factors, confounding, and the illusion of statistical control.

When experimental designs are premature, impractical, or impossible, researchers must rely on statistical methods to adjust for potentially confounding effects. Such procedures, however, are quite fallible. We examine several errors that often follow the use of statistical adjustment.

Pseudoaneurysm of profunda femoris artery following intertrochanteric fracture of the hip.

The authors report a case of pseudoaneurysm of the profunda femoris artery following fixation of an intertrochanteric hip fracture with a dynamic hip screw. Diagnosis and treatment of this rare complication are described.

Determining the effects of eyewear fogging on visual task performance.

The effect of fog on eyewear was evaluated by having individuals perform a target detection task in environments that typically cause eyewear to fog while wearing either eyewear that had been treated with anti-fog coating, eyewear not treated, or no eyewear. Detection was higher with eyewear that had been treated with anti-fog coating compared to uncoated lenses and no difference was observed between wearing coated eyewear and wearing no eyewear. The study concluded that fogging of lenses has a significant effect on visual detection and the use of anti-fog coating is relatively effective.

Fetal heart rate reactivity differs by women's psychiatric status: an early marker for developmental risk?

Objective: To determine whether there are differences in fetal heart rate (FHR) reactivity associated with women's psychiatric status.

Method: In 57 women in their 36th to 38th week of pregnancy (mean age 27 +/- 6 years), electrocardiogram, blood pressure (BP), respiration (RSP), and FHR were measured during baseline and a psychological challenge (a Stroop color-word matching task). Subjects underwent the Structured Clinical Interview for DSM-IV (SCID) and completed the Spielberger State-Trait Anxiety Inventory prior to testing.

Hostility, interpersonal interactions, and ambulatory blood pressure.

Objective: This study examined aspects of the transactional model of hostility and health by investigating relationships among hostility, interpersonal interactions, and ambulatory blood pressure in a healthy community sample.

Materials And Methods: Participants included 65 female and 39 male healthy adults between the ages of 18 and 46 years. Ambulatory blood pressure (ABP) and diary data on mood and social interactions were obtained every 20 minutes for 1 day.

Deriving heart period variability from blood pressure waveforms.

International standards for calculating heart period variability (HPV) from a series of R-wave intervals (R-R) in an electrocardiographic (ECG) recording have been widely accepted. It is possible, and potentially useful in various settings, to use systolic blood pressure waveform intervals to estimate HPV, but the validity of HPV derived from blood pressure (BP) waveforms has not been established. To test the reliability between BP- and ECG-derived HPV indexes, we evaluated data from 234 healthy adults in four studies of HPV reactivity to stress.

Evaluation of blood pressure and baroreflex sensitivity by radial artery tonometry versus finger arteriolar photoplethysmography.

Background: Published normative data of noninvasive blood pressures (BPs) and autonomic modulations have been primarily derived from the finger arteriole using the Finapres (Ohmeda Co., Englewood, CO), a device that is no longer manufactured. Currently, beat-to-beat BP are obtained from the radial artery using the Colin tonometer.

Low arterial compliance in young African-American males.

Hypertension remains a common public health challenge because of its prevalence and increase in co-morbid cardiovascular diseases. Black males have disproportionate pathophysiological consequences of hypertension compared with any other group in the United States. Alterations in arterial wall compliance and autonomic function often precede the onset of disease.

Effects of women's stress-elicited physiological activity and chronic anxiety on fetal heart rate.

This study examined the effects of pregnant women's acute stress reactivity and chronic anxiety on fetal heart rate (HR). Thirty-two healthy third trimester pregnant women were instrumented to monitor continuous electrocardiography, blood pressure, respiration, and fetal HR. Subjects completed the trait anxiety subscale of the State Trait Anxiety Index, then rested quietly for a 5-minute baseline period, followed by a 5-minute Stroop color-word matching task and a 5-minute recovery period.

The carboxyl side chain of glutamate 681 interacts with a chloride binding modifier site that allosterically modulates the dimeric conformational state of band 3 (AE1). Implications for the mechanism of anion/proton cotransport.

Glutamate 681 is thought to be located within the transport channel of band 3 (AE1, the chloride/bicarbonate exchanger), where it acts as a proton donor for the anion/proton cotransport function. Here we show that neutralization of the negative charge on glutamate 681 by chemically modifying band 3 with Woodward's reagent K plus sodium borohydride (i.e.

Benzodiazepines and related drugs for insomnia in palliative care.

Background: Insomnia, a subjective complaint of poor sleep and associated impairment in daytime function, is a common problem. Currently, benzodiazepines are the most used pharmacological treatment for this complaint. They are considered helpful for occasional short-term use up to four weeks but longer term use is not advised due to potential problems regarding tolerance, dosing escalation, psychological addiction and physical dependence.

Temporal stability of acute stress-induced changes in leukocyte subsets and cellular adhesion molecules in older adults.

This study investigated the temporal stability of enumerative immune and catecholamine responses to acute psychosocial stress in 67 Alzheimer's caregivers ages 56-82 years (45 women and 22 men) who were required to prepare and deliver two 3-min speeches on three occasions at 2-week and 6-week intervals. All leukocyte subsets and adhesion molecules (CD62L and CD11a) changed significantly from rest to postspeak at each of the three testing sessions (p's <.0005).

Claims about religious involvement and health outcomes.

Claims about religion, spirituality, and health have recently appeared with increasing frequency, in both the popular media and professional journals. These claims have asserted that there are a great many studies in the literature that have examined relations between religious involvement and health outcomes and that the majority of them have shown that religious people are healthier. We examined the validity of these claims in two ways: (a) To determine the percentage of articles in the literature that were potentially relevant to such a claim, we identified all English-language articles with published abstracts identified by a Medline search using the search term religion in the year 2000, and (b) to examine the quality of the data in articles cited as providing supportfor such a claim, we examined all articles in the area of cardiovascular disease and hypertension cited by two comprehensive reviews of the literature.

Percutaneous endoscopic gastrostomy feeding in a district rehabilitation service.

Objectives: To examine gender, diagnosis, age, reasons for feeding, nutritional status, complications, outcome and duration of feeding in patients who have required a percutaneous endoscopic gastrostomy (PEG) for nutritional support at a district rehabilitation unit in the six years since the service was established. To identify potential for improvements in the management of future patients.

Design: Retrospective case note review of cases from 1992 to 1998.

Relation between depression after coronary artery bypass surgery and 12-month outcome: a prospective study.

Background: The association of depression with cardiac events has been investigated mainly in community cohorts, in patients undergoing catheterisation, or in patients who have had myocardial infarction. We have assessed the effect of depression on outcomes after coronary artery bypass graft (CABG) surgery.

Methods: In a prospective study, we followed up for 1 year 207 men and 102 women, who had undergone coronary artery bypass graft surgery.

Vagal rebound and recovery from psychological stress.

Objective: To characterize cardiovascular recovery and examine the possible relationship of vagal activity and reflexes to risk for heart disease.

Methods: Subjects performed cold pressor and mental arithmetic tasks. Heart rate, heart period variability, and pre-ejection period were obtained for 1 minute before, during, and after each task (Experiment 1).

Structure of pyruvate dehydrogenase kinase. Novel folding pattern for a serine protein kinase.

The structure of mitochondrial pyruvate dehydrogenase kinase isozyme 2 is of interest because it represents a family of serine-specific protein kinases that lack sequence similarity with all other eukaryotic protein kinases. Similarity exists instead with key motifs of prokaryotic histidine protein kinases and a family of eukaryotic ATPases. The 2.

Enhanced stress reactivity in paediatric anxiety disorders: implications for future cardiovascular health.

The aim was to clarify the developmental nature of associations between psychiatric illness and risk for cardiovascular disease by investigating differences in cardiac functioning between youth with anxiety disorders and healthy controls. Twenty-two children meeting DSM-IV criteria for either separation anxiety disorder, overanxious disorder, panic disorder/panic attacks, or social phobia and 12 healthy controls underwent continuous electrocardiogram and respiration rate monitoring during a 15 min baseline period and 15 min of exposure to 5% CO(2). Heart rate (HR) and high frequency heart rate variability (HRV), a non-invasive measure of cardiac parasympathetic control, were calculated.

Hostility, gender, and cardiac autonomic control.

Objective: Although considerable evidence implicates hostility in the development of coronary artery disease (CAD), the pathogenic mechanisms remain poorly understood. We have developed a psychophysiological model that holds that altered autonomic nervous system function links psychological traits with CAD outcomes. In laboratory studies, stressors reduce high-frequency (HF) heart period variability, an index of cardiac vagal modulation.