2-min Step Research Articles

Comparison of Isokinetic Muscle Power and Physical Fitness by Using Body Mass Index in Women Over 70 Years of Age

The purpose of study was to compare isokinetic muscle power and senior fitness test in women over 70 years of age. Subjects were divided into 2 groups: normal-weight group (BMI < 18.5 - 24.9 kg/m2, n = 20, 72.4 ± 1.8yrs) and overweight group (BMI > 25 kg/m2, n = 20, 72.8 ± 1.8yrs). Main results were as follows: 1) Isokinetic peak torque was higher in the left extensor and right flexor at 60o/sec and in the left extensor, right extensor, and right flexor at 180o/sec in the normal-weight group than in the overweight group. 2) Peak torque %BW was higher in the normal-weight group than in the overweight group for all items. 3) Bilateral strength ratio of the quadriceps femoris muscle was higher in the overweight group than in the normal-weight group, which implies a greater susceptibility to injury. 4) SFT revealed greater physical function in the chair stand, 2-min step test, and 8-foot up-and-go test in the normal-weight group than in the overweight group. Therefore, high BMI decreases leg function and limits physical activity. Further studies on the characteristics of leg function in elderly individuals should be performed to ensure systematic health management.

Association between out‐of‐home trips and older adults' functional fitness

To explore the purposes of older adults' out-of-home trips, and to investigate the association between the frequency of these trips and older adults' functional fitness. A total of 412 older adults in Taiwan were recruited from 2009 to 2010. Participants were asked to fill out questionnaires on out-of-home trips, and trained volunteers assessed the functional fitness of respondents using objective measures. Descriptive statistics, univariate analysis, multivariate regression analysis and canonical correlation analysis were then used to analyze the resulting data. Results show that exercise is most frequently the purpose for going out at least once a day, and that parks are the most preferred places to visit. Sex and age are the significant variables explaining variance in older adults' flexibility and physical power, respectively. Canonical correlation analysis showed one significant variate pair (R(2)(c) = 8.80) between the frequency of out-of-home trips (engaging in exercise and participating in religious activities) and fitness measure test scores including the chair stand, arm curl, 2-min step, and 8-foot up-and-go. The relationship did not exist for the back scratch, nor chair sit-and-reach test scores. The present study provides empirical and objective evidence on older adults' purposes for taking out-of-home trips, and for the positive association between the frequency of these trips, and the muscular strength and cardiovascular endurance, but not flexibility, of older adults.

A structural equation model relating physical function, pain, impaired mobility (IM), and falls in older adults

The current study used a structural equation model to investigate the interrelationships among physical function, pain, IM, and falls in 511 American older adults. The model included 11 measurement variables (tandem stance, single leg stance, 360° turn, chair stand, arm curl, sit and reach, back scratch, normative score of 6-min walk or 2-min step, timed up and go, pain, and fall) and four latent variables (balance, strength, flexibility, and IM). The final model with the combined sample demonstrated good fit with the participant data (χ2(31)=30.0, N=499, p=0.52; Goodness of Fit Index (GFI)=0.99). Balance had a significant and the largest effect on IM (standardized regression weights=−1.05, p<0.001). Strength, endurance, flexibility, and pain had small effects on IM (standardized regression weights<0.2). The findings suggest that balance and mobility testing should be a priority in fall screening and prevention programs.

Effect of Group Stretching Training on Functional Fitness for Elderly in Long-Term-Care

This study examined the effect of twelve-week group stretching training on functional fitness of elderly in long term care. Twenty subjects were in long term care were volunteered for this study. Subjects were randomly assigned into an exercise group (n = 9; 83 ± 4.41 years old) or control group (n = 11; 82 ± 3.59 years old). The exercise group participated in group stretching training twice a week for twelve-week. All subjects were undergone for functional fitness test and health medicine status questionnaire before and after twelve-week training. Independent t-test was used to analyze the data. The results showed that 30-s chair stand (2.89 ± 2.20 vs. -1.64 ± 1.80 times), grip strength (1.74 ± 2.83 vs. -2.59 ± 4.20 kilogram), 30-s arm curl (2.67 ± 4.03 vs. -2.81 ± 4.24 times), single-foot standing test with eyes-opened (3.26 ± 1.80 vs. -3.83 ± 7.87 sec), functional reach (6.71 ± 7.48 vs. -4.78 ± 3.88 cm), five-meter gait speed (-1.33 ± 1.41 vs. 1.49 ± 1.66 sec) and 2-min step test (23.78 ± 20.17 vs. -17.36 ± 17.19 times) significantly increased after twelve-week group stretching training (TWGST). Therefore, our study results conclude that TWGST may effectively helpful against the decline of strength, flexibility, balance, mobility and cardiorespiratory endurance of elderly individuals in long term care.

Efeito da adição de 1kg de sobrecarga em um programa de exercício físico na aptidão física de mulheres de meia-idade e idosas

The objective of this study was to analyze the effects of 1 kg of overload in a community-based exercise program in physical fitness in older and middle-aged women. Twenty-one middle aged and elderly women were randomly divided into two groups: workload (WG n=12) and control (CG n=9). Both groups performed 16 sessions of the same exercise program, however, the WG performed the exercises with 1kg of overload. Before and after the training program both groups performed fitness test battery. After the training program the improvements in 30-s chair stand, arm curl, 2-min step test, 8-ft up-and-go, chair sit-and-reach, back scratch were similar between groups. In conclusion, the inclusion of a 1kg overload did not promote further increases in physical fitness in older and middle-age women.

Characterization of bacterial lipid profiles by using rapid sample preparation and fast comprehensive two‐dimensional gas chromatography in combination with mass spectrometry

The bacteria fatty acid profile has been extensively studied for taxonomic classification purposes, since bacteria, in general, contain particular and rare fatty acids, compared with animal and plant tissues. As for any real-world sample type, the development of rapid and reliable methods for (i) sample identification (in this case, bacterium type), and (ii) constituent identification (in this instance, the fatty acid profile) is desirable. In this research, a half-an-hour procedure, to analyze bacteria, was developed: a 2-min one-step sample preparation step was followed by a relatively fast comprehensive 2D GC-MS separation (25 min). Furthermore, dedicated MS libraries were constructed for the identification of bacteria and fatty acids. Finally, data processing, only qualitative at this stage, was carried out with the support of a novel comprehensive 2D GC software.

Maintaining The Benefits Of A 'Real-world' Diabetes Prevention Program: Effect Of A Supplementary Lifestyle Program

PURPOSE: To determine the effectiveness of a supplementary lifestyle program to maintain the benefits previously achieved in a 'real-world' intervention by adults at risk of developing type 2 diabetes. METHODS: 37 adults (31 f, 6 m) participated in the 1-y program 2-y after the completion of an initial 1-y group-based lifestyle (diet and exercise) intervention for individuals at high risk of developing type 2 diabetes. The intervention and program were based upon self management principles. The program was designed to meet the participant needs. It included 2, 2-h face-to-face 'refresher' sessions and individualised written support. Data were gathered at baseline, completion of the 1-y intervention, and at the beginning and end of the 1-y program. Variables measured included: Fasting Plasma Glucose (FPG) (mmol·L-1), 2-h Plasma Glucose (2h-PG) (mmol·L-1), Systolic (SBP) and Diastolic (DBP) blood pressure (mmHg), body weight (BW) (kg), physical activity (PA) (weighted min·week-1), total energy intake (kJ·day-1), dietary saturated fat (%), sit to stand (total count) and 2-min step test (total count). Data were analysed using ANOVA with Intention-to-treat (p<0.05). RESULTS: In the 2-y period after the 1-y intervention, significant partial reversals occurred in FPG, BW, total energy intake, sit to stand and 2-min step test. Notable exceptions were 2h-PG, SBP, DBP and PA. During the program, significant improvements occurred in most variables except 2-min step test. A notable exception was 2h-PG, for which very little change occurred in the mean value following the initial intervention. Overall, significant improvements from baseline were sustained throughout the 4-y period in SBP and DBP, BW, total energy intake and dietary saturated fat. The significant reduction in 2h-PG achieved during the initial program was also sustained, although significance was only attained after the program. For a further 3 measures (FPG, PA, sit to stand) significant improvement was achieved in the initial intervention, lost in the intervening period and regained in the supplementary program. CONCLUSIONS: A 12-month program can effectively maintain or re-establish the reduction in diabetes risk factors initially gained in a 'real-world' diabetes prevention program.

Estabilidade das variáveis de aptidão física e capacidade funcional de mulheres fisicamente ativas de 50 a 89 anos.

The objective of this study was to evaluate the effect of a physical activity program and the stability of physical fitness and functional capacity in physically active adult women. Thirty-four adult women aged 50-89 years, who participated in a physical activity group at Camilo Castelo Branco University, were studied. Criteria for inclusion were attendance of at least 75% of the classes (3x/week) and undergoing at least one assessment per year between 2005 and 2007. All evaluations were conducted in June. Anthropometric (body weight, height, waist-hip ratio), neuromotor (rising from a chair in seconds, rising from a chair in 30 seconds, elbow flexion, shuttle-run, static and dynamic balance), and metabolic parameters (2-min step in place test according to the CELAFISCS standard) were evaluated. One-way ANOVA followed by the post hoc Scheffe test, delta percentage and Spearman’s rho correlation were used for data analysis, with the level of significance set at p&lt;0.05. In the three evaluations, body weight, body mass index and waist-hip ratio indicated overweight. Analysis of functional capacity showed a significant increase in upper (42%) and lower (5.2%) limb strength and in balance (14.1%) when comparing the results from 2005 to 2007. The same was not observed for agility (2.1%). For body mass index, waist-hip ratio, strength and static balance, stability ranged from 0.26 to 0.91 (p&lt;0.05. The physical activity program contributed to the maintenance of physical fitness and functional capacity in adult women.

Physical fitness of post-menopausal women submitted to a physical activities programme

Physical fitness of post-menopausal women submitted to a physical activities programme Study aim: To evaluate the effects of the ‘Menopause-in-Shape Programme’ on physical fitness of elderly women. Material and methods: A group of 323 elderly women lodged in the House for the Elderly participated in a 10-month programme (dancing or walking) and formed the experimental group. Another group of 289 elderly women (control) were sedentary throughout the study. All of them aged 60 - 89 years. Both groups were subjected to the Fullerton Functional Fitness Test battery: chair stand test (CST), arm curl test (ACT), 6-min walk test (6-WT), 2-min step test (2-ST), chair sit and reach test (SRT), scratch test (SCT) and 8-foot up and go test (8-UG). Results: In the experimental group, improvements were noted in CST (by 11.7%; p&lt;0.001), ACT (by 9%; p&lt;0.001), 2-ST (by 2.2%; p&lt;0.001) and 8-UG (by 0.4%; p&lt;0.05) but not in somatic variables. No significant changes were noted in the control group. Conclusions: The Menopause-in-Shape Programme is an efficient tool in improving physical fitness of elderly women even if no somatic effects can be expected.

The falling risk and physical fitness in older people

Aims of this study was to analyze the correlation between the falling risk and their physical fitness, determining the top parameters affecting the falling risk, and preparing an evaluation procedure for the medical department working on this issue for the old people in retirement homes. This study includes 60 persons whose mean age was 73.3 ± 6.6 years. Their demographic characteristics, cognitive function, their balance, falling risk and their physical fitness level have been evaluated. A survey has been done to determine their demographic features. The cognitive function was determined using mini-mental state examination (MMSE) test; for falling risk the Berg balance test (BBT) and balance by standing on one foot test were used, and the physical fitness was determined by senior fitness test (SFT). While the BBT correlation between chair stand, arm curl and 2-min step test are positive; but the correlation between BBT and ‘8-foot up-and-go test’ were negative. However, there was no correlation between the BBT and chair sit-and-reach test, back scratch test ( p > 0.05). Due to the results of logistic regression models in order to find out the variations affecting the falling risk most, it has been showed that ‘8-foot up-and-go test’ was reliable. Additionally the subjects probability performing the ‘8-foot up-and-go’ before 8.14 s was OR = 11 (95% confidence interval = 95%CI = 2.25–53.84) times more with maximum 56 points in BBT. We have shown that the falling risk increases with declining of upper and lower extremity muscle strength, aerobic endurance, agility and dynamic balance performance. Agility and dynamic balance performance were mostly relevant with falling risk. We concluded that the old persons’ falling risk and physical fitness level should be evaluated in some intervals. According to their falling risks and physical fitness level, the rehabilitation programs should be programmed to decrease their falling risk, and to increase lower and upper extremity muscle strength, aerobic endurance and especially their agility and dynamic balance performance.

Altered whole kidney blood flow autoregulation in a mouse model of reduced beta-ENaC.

Renal blood flow (RBF) autoregulation is mediated by at least two mechanisms, the fast acting myogenic response (approximately 5 s) and slow acting tubuloglomerular feedback (TGF; approximately 25 s). Previous studies suggest epithelial Na(+) channel (ENaC) family proteins, beta-ENaC in particular, mediate myogenic constriction in isolated renal interlobar arteries. However, it is unknown whether beta-ENaC-mediated myogenic constriction contributes to RBF autoregulation in vivo. Therefore, the goal of this investigation was to determine whether the myogenic mediated RBF autoregulation is inhibited in a mouse model of reduced beta-ENaC (m/m). To address this goal, we evaluated the temporal response of RBF and renal vascular resistance (RVR) to a 2-min step increase in mean arterial pressure (MAP). Pressure-induced changes in RBF and RVR at 0-5, 6-25, and 110-120 s after step increase in MAP were used to assess the contribution of myogenic and TGF mechanisms and steady-state autoregulation, respectively. The rate of the initial increase in RVR, attributed to the myogenic mechanism, was reduced by approximately 50% in m/m mice, indicating the speed of the myogenic response was inhibited. Steady-state autoregulation was similar between beta-ENaC +/+ and m/m mice. Although the rate of the secondary increase in RVR, attributed to TGF, was similar in beta-ENaC +/+ and m/m mice, however, it occurred over a longer period (+10 s), which may have allowed TGF to compensate for a loss in myogenic autoregulation. Our findings suggest beta-ENaC is an important mediator of renal myogenic constriction-mediated RBF autoregulation in vivo.

Recombinant Expression and Biochemical Characterization of the Unique Elongating β-Ketoacyl-Acyl Carrier Protein Synthase Involved in Fatty Acid Biosynthesis of Plasmodium falciparum Using Natural and Artificial Substrates

The human malaria parasite Plasmodium falciparum synthesizes fatty acids by using a type II synthase that is structurally different from the type I system found in eukaryotes. Because of this difference and the vital role of fatty acids, the enzymes involved in fatty acid biosynthesis of P. falciparum represent interesting targets for the development of new antimalarial drugs. beta-Ketoacyl-acyl carrier protein (ACP) synthase (PfFabBF), being the only elongating beta-ketoacyl-ACP synthase in P. falciparum, is a potential candidate for inhibition. In this study we present the cloning, expression, purification, and characterization of PfFabBF. Soluble protein was obtained when PfFabBF was expressed as a NusA fusion protein in Escherichia coli BL21(DE3)-CodonPlus-RIL cells under conditions of osmotic stress. The fusion protein was purified by affinity and ion exchange chromatography. Various acyl-P. falciparum acyl carrier protein (PfACP) substrates were tested for their specific activities, and their kinetic parameters were determined. Activity of PfFabBF was highest with C(4:0)- to C(10:0)-acyl-PfACPs and decreased with use of longer chain acyl-PfACPs. Consistent with the fatty acid synthesis profile found in the parasite cell, no activity could be detected with C(16:0)-PfACP, indicating that the enzyme is lacking the capability of elongating acyl chains that are longer than 14 carbon atoms. PfFabBF was found to be specific for acyl-PfACPs, and it displayed much lower activities with the corresponding acyl-CoAs. Furthermore, PfFabBF was shown to be sensitive to cerulenin and thiolactomycin, known inhibitors of beta-ketoacyl-ACP synthases. These results represent an important step toward the evaluation of P. falciparum beta-ketoacyl-ACP synthase as a novel antimalaria target.

The Neurofibromatosis Type 1 Gene Product Neurofibromin Enhances Cell Motility by Regulating Actin Filament Dynamics via the Rho-ROCK-LIMK2-Cofilin Pathway

Neurofibromin is a neurofibromatosis type 1 (NF1) tumor suppressor gene product with a domain that acts as a GTPase-activating protein and functions, in part, as a negative regulator of Ras. Loss of neurofibromin expression in NF1 patients is associated with elevated Ras activity and increased cell proliferation, predisposing to a variety of tumors of the peripheral and central nervous systems. We show here, using the small interfering RNA (siRNA) technique, that neurofibromin dynamically regulates actin cytoskeletal reorganization, followed by enhanced cell motility and gross cell aggregation in Matrigel matrix. NF1 siRNA induces characteristic morphological changes, such as excessive actin stress fiber formation, with elevated negative phosphorylation levels of cofilin, which regulates actin cytoskeletal reorganization by depolymerizing and severing actin filaments. We found that the elevated phosphorylation of cofilin in neurofibromin-depleted cells is promoted by activation of a Rho-ROCK-LIMK2 pathway, which requires Ras activation but is not transduced through three major Ras-mediated downstream pathways via Raf, phosphatidylinositol 3-kinase, and RalGEF. In addition, the exogenous expression of the NF1-GTPase-activating protein-related domain suppressed the NF1 siRNA-induced phenotypes. Neurofibromin was demonstrated to play a significant role in the machinery regulating cell proliferation and in actin cytoskeletal reorganization, which affects cell motility and adhesion. These findings may explain, in part, the mechanism of multiple neurofibroma formation in NF1 patients.

Effects Of Muscular Strength And Endurance Training On Ambulatory Blood Pressure Responses In Hypertensive Elderly

PURPOSE To examine whether a 10-week elastic band exercise program would change an ambulatory blood pressure (BP) reponses during exercise in hypertensive elderly women. METHODS A total of 43 community dwelling women were recruited in the study. They were randomly assigned to either exercise group (EG; n = 24, 72 ± 5, 152 ± 5, 58 ± 6, 130 ± 14, 76 ± 14) or control group (CG; n = 19, 72 ± 5 yrs, 150 ± 6 cm, 53 ± 10 kg, 125 ± 13 systolic BP mmHg, 80 ± 14 diastolic BP mmHg). All have took prescribed anti-hypertensive drugs. The exercise program for EG consisted of upper and lower body muscular strength and endurance training using elastic band at an intensity of 12–14 RPE, 70 min/session, 3 times/wk for 10 weeks, while no treatments were given for CG. Before and after the period, their resting and two types of ambulatory BP were measured. While they performed arm curl on one hand, BP and heart rate (HR) were measured on the other arm. On the other occasion, their BP was measured immediately after 2-min step test (20 cm height). RESULTS The systolic BP (SBP) and diastolic BP (DBP), mean arterial pressure, pulse pressure, rate-pressure product, and HR during resting and exercise did not change after the exercise program (2-way ANOVA, P>0.05). However the magnitude of reduction were greater in resting SBP in EG (5.7) than CG (2.0), and resting DBP in EG (5.2) than CG (−2.0 mmHg) (P<0.05). During arm curl exercise, the magnitude of reduction was greater in SBP in EG (4.5) than CG (−6.1) and in DBP in EG (16.4) than CG (0.0 mmHg) (P<0.05). After the step test, the magnitude of reduction in SBP was greater in EG (5.5) than CG (−4.1 mmHg) (P<0.05). CONCLUSION Ten weeks of muscular strength and endurance training did not result in reduction of absolute values of blood pressure parameters. However, the magnitude of reduction was greater after the exercise program both at rest and during exercise in hypertensive elderly women. This study was supported by the Korean Research Foundation, Brain Korea 21 Programs.

FUNCTIONAL FITNESS IS NOT ASSOCIATED WITH METABOLIC FITNESS IN OLDER WOMEN

Functional fitness is of special relevance for older people since it specifies the physiologic capacity to perform daily activities safely and independently. Metabolic fitness is related to cardiovascular disease risk factors. The relationship between these two parameters is not well established in older women. PURPOSE The aim of this study was to analyze the association between major cardiovascular disease risk factors that characterize metabolic fitness – triglycerides (Tg), high density lipoprotein cholesterol (HDL-chol), insulin, low density lipoprotein cholesterol (LDL-chol) and apolipoprotein CIII -, and functional abilities, included in the Functional Fitness Test battery (Rikli & Jones, 1999), in a sample of postmenopausal women. METHODS Subjects were 136 postmenopausal sedentary women (age: 61.3±6.4 years; weight: 66.5±10.6 kg; height: 154.2±5.7 cm; BMI: 27.9±3.8 kg/m2). Plasma insulin was determined by RIA, HDL-chol and Tg were quantified by enzymatic colorimetric methods, LDL-chol was estimated with the Friedwald equation, and apo C-III was assessed with a immunoturbidimetric assay. The Functional Fitness Test battery included the 30-s chair stand, arm curl, chair sit-and-reach, back scratch, 2-min step, 8-ft up-and-go, and BMI. RESULTS Significant correlations (p < 0.05), controlling for age, were only observed between back scratch and BMI (r=0.31), LDL-chol (r=−0.22) and apo CIII (r=0.26). No differences (p > 0.05) were observed between all other tests included in Functional Fitness Test battery and the metabolic fitness markers studied. CONCLUSIONS These results suggest that functional abilities that support functional mobility in older women are not related with cardiovascular health. Therefore, it seems plausible to consider functional fitness and metabolic fitness as two different components of any disability model identifying relevant parameters for healthy aging. Supported by Foundation for Science and Technology, Portugal.

COMPARISONS OF PHYSICAL CHARACTERISTICS AND FITNESS LEVELS BETWEEN KOREAN AND USA ELDERLY

A lack of standardization in measuring instruments and methods of evaluation has prevented a direct comparison of physical fitness and performance of older Asian and Western populations. PURPOSE: This study used common methods and instrumentation to enable a direct comparison of fitness levels between Korean and USA elderly. METHODS: A total of 1046 Korean elderly (443 men and 603 women) divided into four age groups; 65–69, 70–74, 75–79, and 80–84, participated in a battery of physical fitness tests which consisted of strength (chair stand and arm curl), aerobic endurance (2-min step), flexibility (chair sit-and-reach and back scratch), and agility (8-ft up-and-go). The results were compared to Rikli and Jones's study (J. Aging. Phys. Act., 1999, 7:162-181) from which the instruments and protocol of this study were adapted. RESULTS: In general, Korean elderly men and women were shorter and lighter than USA elderly in all groups (P < 0.05). The tendency of reduced fitness levels with advancing age was similar in both populations. However, upper and lower limb muscular strength was higher in Korean than USA elderly in all age groups and in both sexes (P < 0.001). Korean men were more flexible than USA elderly in the younger two age groups. Korean women showed higher scores in chair sit-and-reach in all ages (P < 0.05) but lower scores for back-scratch in the two older age groups (P < 0.001). Korean men and women were more agile than their USA counterpart. While no differences in endurance were found in men between populations, Korean women showed higher endurance levels in the two younger age groups. USA women demonstrated higher endurance in the oldest age group. CONCLUSION: These data suggest that the Korean elderly was more physically fit than their USA counterpart. However, Korean women showed a greater rate of los of endurance capacity and upper body flexibility in the oldest groups than the USA elderly. Perhaps, the increased emphasis upon fitness and health among USA elderly may account for this reduced decline.

Reliability and Validity of the Fullerton Functional Fitness Test: An Independent Replication Study

A limiting factor in evaluating the functional status of older people is the lack of appropriate measurement tools for assessing functional mobility, muscle strength, aerobic endurance, agility, and flexibility. In this study, the reliability and validity of the seven-item Fullerton Functional Fitness Test (FFT) battery, designed for use with community-dwelling older adults, was examined. The test items were as follows: floor sit-and-reach, back scratch, 8-ft up-and-go, arm curl, 30-s chair stand. 2-min step, and 9-min walk. Seventy-nine participants (42 physically active, 37 sedentary) completed the FFT battery three times within a 2-week period. The test-retest reliability intraclass correlation coefficients were high. Construct validity analysis revealed that five of the seven FFT items discriminated between the physically active and sedentary groups. In conclusion, most of the evidence from the stability reliability and discriminant validity analyses supports the view that the Fullerton FFT battery is a reliable and valid test of functional fitness.

Electrochemical behaviour of dopamine and ascorbic acid at overoxidized polypyrrole(dodecyl sulphate) film-coated electrodes

The electrochemical behaviour of dopamine and ascorbic acid at overoxidized polypyrrole(dodecyl sulphate) film-coated glassy carbon electrodes was investigated. It was found that dopamine can be efficiently accumulated into the film and the voltammetric detection limit of dopamine is greatly improved by this procedure. The current response was linear in the concentration range 0.1–10 μM and a detection limit of 40 nM was achieved when a 2-min preconcentration step under open-circuit conditions was used. A high selectivity for dopamine was observed owing to the exclusion of anionic species by the negative charges in the film. Chronoamperometry and chronocoulometry were used to determined the concentration and diffusion characteristics of dopamine within the film as a function of dopamine concentration in the solution and the film thickness. The film was found to protect the substrate electrode surface from poisoning by the oxidation product of dopamine. Good reproducibility was observed for multiple measurements of dopamine in 0.1 M phosphate buffer solution (pH 7.4).

Effect of exercise testing protocol on parameters of aerobic function

Four different patterns of increasing work rate (ramp and 1-min, 2-min, and 3-min steps) to maximum tolerance were studied in eight normal male subjects during cycle ergometer exercise testing to determine the effect of the work rate protocol on the parameters of aerobic function. The overall rate of work rate increase was kept constant. Measurements included VO2max, anaerobic threshold (AT), and the O2 uptake increase with respect to work rate increase (delta VO2/delta WR). VO2, VCO2, VE, respiratory exchange ratio (R), PETCO2, and PETO2 were calculated breath-by-breath. No significant difference was found in VO2max, AT, AT/VO2max, and delta VO2/delta WR among the four work rate protocols. Other measurements such as total work, maximal work rate, VCO2, VE, R, HR, O2 pulse, and the VO2 at which VE increases disproportionately to VCO2 (ventilatory compensation point) were also similar among the four protocols. Both the ramp and 1-min step work rate tests had no step pattern in either VO2 or VCO2, and the step pattern for the 2-min and 3-min step tests was attenuated or disappeared at work rates above AT. We conclude that the parameters of aerobic function, and other physiological responses at maximum work rate, were independent of the pattern of work rate increase, provided that the overall rate of work rate increase was the same.

Evaluation of New Rapid Office Test for Microalbuminuria and Its Comparison to Fully Quantitative Radioimmunoassay

A novel enzyme-linked immunosorbent assay (ELISA [Dialbumin]) for rapid office measurement of microalbuminuria was evaluated and its performance compared with that of a commercially available radioimmunoassay (double-antibody albumin). Urine samples containing between 0.75 and 1800 micrograms/ml of albumin were obtained from 31 diabetic patients and assayed by both methods. A comparison of the paired values obtained from the two methods gave a correlation coefficient of greater than 0.99. The Dialbumin assay, which used detachable eight-well strips (1 strip/sample), 10-min incubation, tap water wash, and a 2-min color development step, was read on both an ELISA reader and a hand-held analytical device (Acc-U-Dial) designed specifically for this test. The findings of this study indicate that the Dialbumin assay, used in conjunction with the Acc-U-Dial device, affords a rapid, convenient, and sensitive method for quantitative determination of a broad range (0.3-1280 micrograms/ml) of urinary albumin levels in the office setting.