A psychophysiological comparison of on-sight lead and top rope ascents in advanced rock climbers.

Research suggests that lead climbing is both physiologically and psychologically more stressful than top rope climbing for intermediate performers. This observation may not be true for advanced climbers, who train regularly on lead routes and are accustomed to leader falls. The aim of this study was to compare the psychophysiological stresses of lead and top rope on-sight ascents in advanced rock climbers. Twenty-one climbers (18 men and three women) ascended routes near or at the best of their ability (22 Ewbank). Psychological stress was measured preclimb using the Revised Comparative State Anxiety Inventory (CSAI-2R). Plasma cortisol was sampled at six intervals. The volume of oxygen (VO2 ) and heart rate (Hr) were measured throughout the climbs. No significant differences were found in self-confidence, somatic, or cognitive anxiety between the conditions lead and top rope. No significant differences in plasma cortisol concentration were found between any time points. No significant relationships were found between cortisol and any CSAI-2R measures. No significant differences were found between conditions for VO2 or blood lactate concentration. During the lead climb, Hr was significantly elevated during the last part of the route. Findings suggest that advanced rock climbers do not find lead climbing to be more stressful than top rope climbing during an on-sight ascent.

Plasma cortisol concentrations and perceived anxiety in response to on-sight rock climbing.

Previous research suggested plasma cortisol concentrations in response to rock climbing have a cubic relationship with state anxiety and self-confidence. This research, however, was conducted in a situation where the climbers had previously climbed the route. The purpose of our study was to examine this relationship in response to on-sight climbing. Nineteen (13 male, 6 female) intermediate climbers volunteered to attend anthropometric and baseline testing sessions, prior to an on-sight ascent (lead climb or top-rope) of the test climb (grade 19 Ewbank/6a sport/5.10b YDS). Data recorded included state anxiety, self-confidence and cortisol concentrations prior to completing the climb. Results indicated that there were no significant differences in state anxiety, self-confidence and plasma cortisol concentration regardless of the style of ascent (lead climb or top-rope) in an on-sight sport climbing context. Regression analysis indicated there was a significant linear relationship between plasma cortisol concentrations and self-confidence (r= - 0.52, R2=0.267, p=0.024), cognitive (r=0.5, R2=0.253, p=0.028), and somatic anxieties (r=0.46, R2=0.210, p=0.049). In an on-sight condition the relationships between plasma cortisol concentrations with anxiety (cognitive and somatic) and self-confidence were linear.

Sport-specific power assessment for rock climbing.

AIM: The popularity of rock climbing has resulted in a growing research base for the sport. However, at present there is a lack of sport-specific measures of performance in the field. The aim of this study was to examine the use of the powerslap test as a sport specific power measure. METHODS: The participants in this study were categorised into four different ability groups (novice, intermediate, advanced and elite) based on self reported lead grade. Two separate experiments were conducted to determine validity and reliability. The powerslap test was conducted on a revolution board with two variations - wide and narrow grip, for both sides of the body. The test started with the climber hanging at full extension from two holds from which a pull up movement was made releasing one hand to slap a scaled score board above. RESULTS: There was a significant relationship between powerslap scores and climbing ability (Left Wide: r=0.7, P<0.0005; right wide: r=0.69, P<0.0005; left narrow: r=0.73, P<0.0005; right narrow: r =0.72, P<0.0005). Further to this, scores on the powerslap narrow test were significantly differentiated by climber ability (LEFT: F(3,37)=15.74, P<0.0005; right: F(3,37)=12.16, P<0.0005). Limits of agreement and intra-class correlation indicated that the powerslap test is a reliable performance measure. CONCLUSION: According to the present findings the narrow grip variation of the powerslap test is a useful sport-specific power test that is related to climbing performance.

Comparison of lactate sampling sites for rock climbing.

Comparisons of capillary blood lactate concentrations pre and post climb have featured in the protocols of many rock climbing studies, with most researchers obtaining samples from the fingertip. The nature of rock climbing, however, places a comparatively high physiological loading on the foreaand fingertips. Indeed, the fingertips are continually required for gripping and this makes pre-climb sampling at this site problematic. The purpose of our study was to examine differences in capillary blood lactate concentrations from samples taken at the fingertip and first (big) toe in a rock climbing context. 10 participants (9 males and 1 female) completed climbing bouts at 3 different angles (91°, 100° and 110°). Capillary blood samples were taken simultaneously from the fingertip and first toe pre and post climb. A limit of agreement plot revealed all data points to be well within the upper and lower bounds of the 95% population confidence interval. Subsequent regression analysis revealed a strong relationship (R (2)=0.94, y=0.940x + 0.208) between fingertip and first toe capillary blood lactate concentrations. Findings from our study suggest that the toe offers a valid alternative site for capillary blood lactate concentration analysis in a rock climbing context.

Depth of cure and compressive strength of dental composites cured with blue light emitting diodes (LEDs).

OBJECTIVE: The primary objective of this pilot study was to test the hypotheses that (i) depth of cure and (ii) compressive strength of dental composites cured with either a light emitting diode (LED) based light curing unit (LCU) or a conventional halogen LCU do not differ significantly. The second objective of this study was to characterise irradiance and the emitted light spectra for both LCUs to allow comparisons between the units. METHODS: Dental composite (Spectrum TPH, shades A2 and A4) was cured for 40 s with either a commercial halogen LCU or a LED LCU, respectively. The LED LCU uses 27 blue LEDs as the light source. The composites' depth of cure was measured for 10 samples of 4 mm diameter and 8 mm depth for each shade with a penetrometer. The results were compared using a Student's t-test. Compressive strengths were determined after 6 and 72 h, for six samples of 4 mm diameter and 6 mm depth for each shade after being polymerised for 40 s from each end of the mould. Groups were compared using a three way ANOVA. RESULTS: The conventional halogen LCU cured composites significantly (p < 0.05) deeper (6.40 mm A2, 5.19 mm A4) than did the LED LCU (5.33 mm A2, 4.27 mm A4). Both units cured the composite deeper than required by both ISO 4049 and the manufacturer. A three way ANOVA showed that there were no significant differences in the compressive strengths of samples produced with either the LED LCU or the halogen LCU (p = 0.460). Significant differences in compressive strength of samples stored for 6 and 72 h (p = 0.0006) and of samples of different shades (p = 0.035) were found as confirmed by the three way ANOVA. The light spectra of both units differed strongly. While the halogen LCU showed a broad distribution of wavelengths with a power peak at 497 nm, the LED LCU emitted most of the generated light at 465 nm. The LED LCU produced a total irradiance of 350 mW cm-2 whereas the halogen LCU produced a total irradiance of 755 mW cm-2. SIGNIFICANCE: The results showed that both units provided sufficient output to exceed minimum requirements in terms of composites' depth of cure according to ISO 4049 and the depth of cure and the composites' compressive strength stated by the manufacturer. Compressive strengths of dental composites cured under laboratory conditions with a LED LCU were statistically equivalent to those cured with a conventional halogen LCU. With its inherent advantages, such as a constant power output over the lifetime of the diodes, LED LCUs have great potential to achieve a clinically consistent quality of composite cure.

Changes in left ventricular mass and volumes in patients receiving angiotensin-converting enzyme inhibitor therapy for left ventricular dysfunction after Q-wave myocardial infarction.

OBJECTIVES: We evaluated global and segmental left ventricular (LV) mass and LV mass/volume ratio in patients with LV dysfunction receiving angiotensin-converting enzyme (ACE) inhibitor therapy after acute myocardial infarction (MI). BACKGROUND: ACE inhibitors attenuate LV dilatation and compensatory hypertrophy after acute MI in animal models. However, LV remodeling in patients after acute MI has been largely defined on the basis of changes in chamber volume alone. METHODS AND RESULTS: Twenty-nine patients with LV ejection fraction <40% received the ACE inhibitor ramipril (range 2.5 to 20 mg/day) within 5 days of their first Q-wave MI. Magnetic resonance imaging was performed at baseline and at 3 months, providing global and regional LV volumes and mass from summated serial short-axis slices. Mean arterial blood pressure was unchanged from baseline to 3-month follow-up (89 +/- 10 to 92 +/- 17 mm Hg). LV mass decreased (90 +/- 25 to 77 +/- 21 gm/m2, p < 0.0005) as LV end-diastolic volumes increased (65 +/- 13 to 73 +/- 22 ml/m2, p < 0.01). Global LV mass to volume ratio decreased from 1.40 +/- 0.28 to 1.08 +/- 0.18 gm/ml (p < 0.0001), as did circumferential wall thickness to volume ratio of noninfarcted myocardium at the base of the LV (0.06 +/- 0.02 to 0.05 +/- 0.02 mm/ml, p < 0.001). LV ejection fraction increased from 35 +/- 6 to 40 +/- 9% (p < 0.001) in the presence of an increase in calculated end-systolic wall stress (185 +/- 57 to 227 +/- 54 gm/cm2, p < 0.01). CONCLUSIONS: ACE inhibitor therapy was associated with improved LV function in the face of a decrease in mass to volume ratio of the LV as well as a decrease in wall thickness to volume ratio of noninfarcted myocardium. Whether ACE inhibitor therapy had direct or indirect effects on these changes in LV mass and function are open questions that require further investigation.

Skills training versus psychosocial occupational therapy for persons with persistent schizophrenia.

OBJECTIVE: The authors compared the community functioning of outpatients with persistent forms of schizophrenia after treatment with psychosocial occupational therapy or social skills training, with the latter conducted by paraprofessionals. METHOD: Eighty outpatients with persistent forms of schizophrenia were randomly assigned to receive either psychosocial occupational therapy or skills training for 12 hours weekly for 6 months, followed by 18 months of follow-up with case management in the community. Antipsychotic medication was prescribed through "doctor's choice" by psychiatrists who were blind to the psychosocial treatment assignments. RESULTS: Patients who received skills training showed significantly greater independent living skills during a 2-year follow-up of everyday community functioning. CONCLUSIONS: Skills training can be effectively conducted by paraprofessionals, with durability and generalization of the skills greater than that achieved by occupational therapists who provide their patients with psychosocial occupational therapy.

Evaluation of complex mediastinal masses by magnetic resonance imaging.

MRI was used to diagnose a mediastinal mass in a elderly patient with previous repair of aortic coarctation. MRI excluded aneurysm by demonstrating a homogeneous mass encasing aorta and the bypass graft. A second thoracotomy was avoided. Moreover, outpatient testing was performed, without exposure to contrast agents, ionizing radiation, or an invasive procedure.

Angiotensin-converting enzyme inhibitor therapy affects left ventricular mass in patients with ejection fraction > 40% after acute myocardial infarction.

OBJECTIVES: We tested the hypothesis that angiotensin-converting enzyme (ACE) inhibitor therapy decreases left ventricular (LV) mass in patients with a left ventricular ejection fraction (LVEF) > 40% and no evidence of heart failure after their first acute Q wave myocardial infarction (MI). BACKGROUND: Recently, ACE inhibitor therapy has been shown to have an early mortality benefit in unselected patients with acute MI, including patients without heart failure and a LVEF > 35%. However, the effects on LV mass and volume in this patient population have not been studied. METHODS: Thirty-five patients with a LVEF > 40% after their first acute Q wave MI were randomized to titrated oral ramipril (n = 20) or conventional therapy (control, n = 15). Magnetic resonance imaging (MRI) performed an average of 7 days and 3 months after MI provided LV volumes and mass from summated serial short-axis slices. RESULTS: Left ventricular end-diastolic volume index did not change in ramipril-treated patients (62 +/- 16 [SD] to 66 +/- 17 ml/m2) or in control patients (62 +/- 16 to 68 +/- 17 ml/m2), and stroke volume index increased significantly in both groups. However, LV mass index decreased in ramipril-treated patients (82 +/- 18 to 73 +/- 19 g/m2, p = 0.0002) but not in the control patients (77 +/- 15 to 79 +/- 23 g/m2). Systolic arterial pressure did not change in either group at 3-month follow-up. CONCLUSIONS: In patients with a LVEF > 40% after acute MI, ramipril decreased LV mass, and blood pressure and LV function were unchanged after 3 months of therapy. Whether the decrease in mass represents a sustained effect that is associated with a decrease in morbid events requires further investigation.

Adherence enhancers in pill-related clinical trials: a health behavior in cancer prevention model-based approach.

Preventing non-adherence and treating adherence failure are important to consider in designing community-based clinical trials. The approach and methods for managing adherence are vital. This paper describes a practical and theoretically-based strategy for managing adherence in a small cancer prevention trial with subjects (n = 40) taking a non-steroidal anti-inflammatory drug, piroxicam. Average daily pill intake adherence was exceptionally high (97.4%) as measured by self-report calendar. Thus, the generalized adherence enhancement approach used in this study may have been a related factor, although statistical model-testing was not possible in this small trial. The generalized intervention took into account factors such as the potential barriers and benefits of being in the study, self-efficacy and satisfaction with the participant/staff relationship. These and other theoretical variables were incorporated into an overall adherence strategy that is discussed.

Accuracy of biplane long-axis left ventricular volume determined by cine magnetic resonance imaging in patients with regional and global dysfunction.

Left ventricular (LV) volumes and ejection fraction can be obtained by applying Simpson's rule to multiple short-axis tomographic planes. A simpler method for determining LV volumes using the area-length equation is widely accepted and requires less time to acquire and analyze. Its accuracy, however, is questionable in deformed or asymmetrically contracting ventricles. This study compares biplane long-axis to serial short-axis computed LV volumes obtained by cine gradient-echo magnetic resonance imaging (MRI) in 2 distinct patient populations: (1) patients with global LV dysfunction, and (2) patients with regional LV dysfunction. A total of 114 patients were studied using both methods. Among 37 patients with global LV dysfunction, there was no statistically significant difference between methods (long axis vs short axis) for determining LV end-diastolic volume (203 +/- 91 vs 201 +/- 90 ml), end-systolic volume (142 +/- 81 vs 141 +/- 82 ml), and ejection fraction (33 +/- 12 vs 33 +/- 13%). However, in the 77 patients with regional dysfunction, LV end-diastolic volume was statistically slightly higher when obtained using the long-axis approach (157 +/- 53 vs 152 +/- 51 ml; p=0.004). Otherwise, end-systolic volume (97 +/- 49 vs 95 +/- 49 ml) and ejection fraction (40 +/- 13 vs 40 +/- 13%) were similar (p=NS). The correlation between LV volumes and ejection fractions for both groups was excellent (r >0.91). Thus, in this study group, biplane long-axis and serial short-axis computed LV volumes and ejection fractions were similar in patients with global or regional LV dysfunction. In critically ill patients unable to complete a comprehensive MRI examination, the biplane long-axis-derived volumes provide adequate data.

Optimizing the method to calculate right ventricular ejection fraction from first-pass data acquired with a multicrystal camera.

BACKGROUND: The advantage of radionuclide angiographic techniques used to measure right ventricular ejection fraction (RVEF) is geometry independence, but the weakness is right atrial (RA) overlap. To minimize the effect of RA counts on right ventricular time activity curve (TAC), two regions of interest (ROI), one drawn for the end-diastolic image and one for the end-systolic image, are used for the calculation of RVEF from equilibrium gated blood pool scans (GBPS) and from gated first-pass studies with an Anger camera. A multicrystal camera offers both temporal separation of the bolus to the right side of the heart and good count statistics; therefore first-pass studies performed on a multicrystal camera theoretically should yield the most accurate measurements of RVEF, but few studies have been performed to validate RVEF against a reliable gold standard. METHODS AND RESULTS: To develop and validate an accurate method to measure RVEF from multicrystal first-pass data, 25 patients underwent sequential cine-MRI, first-pass radionuclide angiography, and gated equilibrium imaging. Five additional healthy volunteers underwent cine-MRI alone. Right and left ventricular volumes were measured from serial short axis cine-MRI views according to Simpson's rule. Three methods were used to calculate RVEF from first-pass data: a single ROI method, a dual ROI method, and a method in which a single ROI is applied to RA subtracted first-pass dynamic data. Five additional healthy volunteers underwent cine-MRI alone. When right ventricular stroke volume was plotted versus left ventricular stroke volume for the 5 volunteers and the 15 patients without valvular regurgitation, the regression line was not significantly different from the line of identity, supporting the accuracy of cine-MRI to measure RVEF. The RVEF by cine-MRI ranged from 34% to 59%; first-pass RVEF with a single ROI from 26% to 48%; first-pass RVEF with two ROIs from 31% to 59%; first-pass RVEF with RA subtracted single ROI from 29% to 60%; and RVEF from GBPS with multiple ROIs from 28% to 55%. The regressions for all three of the first-pass methods versus cine-MRI were significant (p < 0.01) as was the regression for the equilibrium GBPS versus cine-MRI but the correlation was weaker. The regressions for the 2-ROI method and for the RA subtracted single ROI method were not significantly different from the line of identity, whereas the regressions for both the single ROI method and for equilibrium GBPS were significantly different from the line of identity (p < 0.01). CONCLUSIONS: Cine-MRI can be used to validate radionuclide algorithms. Of the four radionuclide methods for measuring RVEF that were assessed, the first-pass 2-ROI method and the first-pass RA subtracted single ROI are the most accurate, the first-pass single ROI method underestimates RVEF, and the RVEF values measured from GBPS are less accurate.

Multislice first-pass myocardial perfusion imaging on a conventional clinical scanner.

A technique is demonstrated for the acquisition and processing of multislice, first-pass contrast-enhanced perfusion images in the myocardium. The acquisition is a modification of "keyhole" imaging in which time series images are acquired by sampling a limited segment of k-space, corresponding to the low spatial frequencies. In the modification demonstrated here, keyhole samples are divided into two groups that are sampled on alternate cardiac cycles. The alternate "missing" k-space portions are synthesized by Fourier interpolation. Visualization of contrast agent accumulation by image subtraction is demonstrated. A motion artifact reduction process using time domain Fourier filtering is used to reduce artifacts from respiration. Studies were performed on 46 patients at 1.5 T using gadoteridol (0.05-0.1 mmol/kg) injected into the right antecubital vein in conjunction with radionuclide imaging. Fully concordant studies were noted in 27 of these patients. Remaining studies were either partially or completely discordant for reasons relating to the differing natures of radionuclide versus MR contrast agent characteristics.

Right and left ventricular volumes and function after acute pulmonary hypertension in intact dogs.

A canine model was developed to record right (RV) and left ventricular (LV) volumes and high-fidelity pressures during acute pulmonary hypertension without the need for major surgery. In this study, new methodology was applied to record high-fidelity RV and LV pressures during cinemagnetic resonance imaging of the heart before and after acute pulmonary hypertension in six anesthetized intact dogs in which the pericardium and thorax were never disturbed by any surgical procedure. After pulmonary embolus, RV systolic pressure increased from 27 + 2 (SD) to 43 +/- 8 mmHg (P < 0.01) as LV systolic pressure decreased (97 +/- 17 to 76 +/- 3 mmHg; P < 0.05). Stroke volume (26 +/- 7 to 21 +/- 5 ml; P < 0.05) and RV ejection fraction (45 +/- 9 to 28 +/- 3%; P < 0.01) decreased as LV ejection fraction was unchanged (50 +/- 5 to 52 +/- 5%; P = NS). LV end-diastolic pressure decreased from 11 +/- 4 to 7 +/- 3 mmHg (P < 0.05), and RV end-diastolic pressure increased from 6 +/- 3 to 11 +/- 3 mmHg (P < 0.01). RV end-diastolic volume increased from 57 +/- 14 to 75 +/- 20 ml (P < 0.01) as LV end-diastolic volumes decreased from 53 +/- 11 to 42 +/- 10 ml (P < 0.01), resulting in no change in total ventricular volume at end diastole (111 +/- 24 to 116 +/- 28 ml). The observed mean decrease of 4.0 mmHg and 11 ml in LV end-diastolic pressure and volume, respectively, was associated with no change in total ventricular volume.(ABSTRACT TRUNCATED AT 250 WORDS)

Development of a novel series of trialkoxyaryl derivatives as specific and competitive antagonists of platelet activating factor.

The synthesis and structure-activity relationship (SAR) analysis of a novel series of trialkoxyaryl derivatives, as specific and competitive inhibitors of platelet activating factor (PAF), are described. Molecular modeling comparisons of PAF with the known antagonists Ginkgolide B and L-652731 led to the selection of N-[2-[(3,4,5-trimethoxybenzoyl)oxy]ethyl]-N,N,N-trimethylammonium iodide (1) from the Wellcome registry of compounds and to the synthesis of the lead compound N-[2-[[4-(hexyloxy)-3,5-dimethoxybenzoyl]oxy]ethyl]-N,N,N- trimethylammonium iodide (3, pKb 5.43). Further SAR considerations directed the design to 2-(hexyloxy)-1,3-dimethoxy-5-[4-(4-methylthiazol-5-yl)butyl] benzene (38) (pKb 7.14), a novel, specific, and competitive inhibitor of the PAF receptor in rabbit-washed platelets.

Measurement of prostaglandin E2 in rectal mucosa in human subjects: a method study.

It has been demonstrated and confirmed that certain nonsteroidal anti-inflammatory drugs which inhibit cyclooxygenase and the synthesis of prostaglandins and other eicosanoids, can reduce the formation of both colon polyps and cancers in experimental animals given known carcinogens. Additionally, the results of several epidemiologic studies have suggested that nonsteroidal anti-inflammatory drugs may reduce the risk of colon polyp occurrence and/or colon cancer mortality. We have carried out a study to evaluate the methodology of the measurement of prostaglandin E2 (PGE2) in human colonic mucosa because its concentration may serve as a valuable intermediate marker of the pharmacological activity in Phase II studies of nonsteroidal anti-inflammatory drugs as colon cancer preventive agents. We studied all aspects of the actual measurement of PGE2 including the extraction efficiency of the PGE2 from the mucosa, the precision of the assay and calculation of the PGE2 content in terms of milligrams of protein in the sample, the inhibition of PGE2 by indomethacin over time, the reproducibility of the measurement within one homogenate, the rate of PGE2 production over time, the effect of adding indomethacin versus snap freezing on PGE2 production, the stability of PGE2 in tissues over time stored in liquid nitrogen, and the variability of the measurement of PGE2 in separate biopsies from one individual. Our studies indicated that the most reliable method for accurate and consistent measurements of PGE2 was to add the mucosal tissue instantly after biopsy to an indomethacin buffer that effectively inhibited the in vitro formation of PGE2.

The evolving role of MRI in the assessment of coronary artery disease.

Magnetic resonance imaging (MRI) methods are positioned to make a major impact in the care of patients with ischemic heart disease. Further advances are to be expected in the area of myocardial perfusion imaging and noninvasive MRI coronary "angiography." Work also continues in determining quantitative flow via MRI. Although expensive, the unique ability of MRI methods to provide multiple pieces of information in a single examination may make this technology cost effective. The concept of a "one-step shop" is progressing steadily toward a clinical reality.

Block regional interpolation scheme for k-space (BRISK): a rapid cardiac imaging technique.

We introduce an acquisition method, "block regional interpolation scheme for k-space" (BRISK), to reduce the acquisition time for cardiac imaging. The method exploits the high degree of correlation that exists between time-resolved cardiac images. For representative k-space data sets, Fourier analysis was applied along the cardiac phase dimension to reveal that different regions of k-space can be effectively sampled at different rates. A reduced sampling strategy was implemented, and unsampled points were generated by Fourier interpolation. Time savings of up to 75% are quite feasible and 25% BRISK scans compare well with 100% scans. Simulations and acquisitions using a normal volunteer and patients are presented.

Cardiac amyloidoma with IgM-kappa gammopathy.

A 73-year-old man presented with dyspnea and atrial flutter associated with an amyloid tumor in the heart. IgM-kappa gammopathy, hypercalcemia, and extensive cardiac and mediastinal invasion suggested a malignant lymphoid or plasma cell process. Although amyloidoma is generally considered to be a benign tumor, the aggressive features of this case mandated chemotherapy because the critical location rendered the tumor inoperable. This case provides noteworthy evidence in support of a possible pathogenic relationship between amyloidoma and plasmacytoma by virtue of dual representative features: localized amyloid infiltrated with plasma cells and the associated gammopathy. Local and systemic malignant features lend additional support to this hypothesis.

Adaptive Fourier threshold filtering: a method to reduce noise and incoherent artifacts in high resolution cardiac images.

We introduce an image processing method which reduces white noise and random artifacts in sets of high resolution, time resolved images. At each pixel, the processing consists of: 1) the isolation of a time intensity curve (TIC), 2) Fourier transformation of each TIC, 3) application of a threshold to remove low intensity coefficients, 4) inverse transformation to generate noise reduced TICs which are recombined to form images with improved signal-to-noise ratio (SNR). Noise filtering by Fourier thresholding is demonstrated on a set of cardiac images, resulting in a reduction of the noise energy by approximately 90%.