Marked variation in the cardiomyopathy associated with Friedreich's ataxia

OBJECTIVE

To document the cardiac phenotype associated with Friedreich's ataxia, a recessively inherited disorder characterised by spinocerebellar degeneration.

SETTING

Individuals with Friedreich's ataxia who accepted the invitation to participate in the study.

HYPOTHESIS

The cardiomyopathy associated with Friedreich's ataxia may offer a human model for the study of factors modulating cardiac hypertrophy.

METHODS

55 patients (mean (SD) age 30 (9) years) with a clinical diagnosis of Friedreich's ataxia were studied by clinical examination, electrocardiography, cross sectional and Doppler echocardiography, and analysis of the GAA repeat in the first intron of the frataxin gene.

RESULTS

A wide variety of cardiac morphology was documented. Subjects with normal frataxin alleles had no evidence of cardiomyopathy. In homozygous subjects, a relation was found between the thickness of the interventricular septum (r = 0.53, p < 0.005), left ventricular mass (r = 0.48, p < 0.01), and the number of GAA repeats on the smaller allele of the frataxin gene. No relation was shown between the presence of electrocardiographic abnormalities (mainly repolarisation changes) and either the pattern of ventricular hypertrophy (if present) and degree of neurological disability or the length of time since diagnosis. No tendency to ventricular thinning or dilatation with age was found. Although ventricular systolic function appeared impaired in some cases, Doppler studies of ventricular filling were within the normal range for age.

CONCLUSIONS

The cardiomyopathy associated with Friedreich's ataxia shows a variable phenotype which is not concordant with the presence of ECG abnormalities or the neurological features of the condition. As the genetic basis for Friedreich's ataxia has been established, further studies will help to clarify the molecular mechanisms of the cardiac hypertrophy.

90Yttrium-labeled complementarity-determining-region-grafted monoclonal antibodies for radioimmunotherapy: radiolabeling and animal biodistribution studies

90Yttrium-labeled monoclonal antibodies (mAbs) are likely to be important to radioimmunotherapy (RAIT) of a variety of cancers. The goal of this study was to select and evaluate a form of [90Y]mAb suitable for RAIT and determine conditions for high-yield, reproducible radiolabelings. 90Y-Labelings, at 2-40 mCi levels, of cdr-grafted versions of anti-B-cell lymphoma (hLL2) and anti-CEA (hIMMU-14) mAbs were optimized to >90% incorporations using the macrocyclic chelator DOTA as the metal carrier. In in vitro challenge assays, the stability of mAbs labeled with [90Y]DOTA was better than that of the corresponding [90Y]benzyl-DTPA conjugates. The retention of [90Y]DOTA-hLL2 on Raji tumor cells in vitro was similar to that of the same mAb labeled with [90Y]benzyl-DTPA and was about twice as much as with [125I]hLL2, indicating residualization of metalated mAb. Both [90Y]hLL2 conjugates, prepared using DOTA and Bz-DTPA, had similar maximum tolerated doses of 125 muCi in BALB/c mice and showed no discernible chelator-induced immune responses. Animal biodistribution studies in nude mice bearing Ramos human B-cell lymphoma xenografts revealed similar tumor and tissue uptake over a 10 day period, with the exception of bone uptake which was up to 50% lower for [88Y]DOTA-hLL2 compared to [88Y]Bz-DTPA-hLL2 at time points beyond 24 h. With [90Y]DOTA-hLL2 fragments, in vivo animal tumor dosimetries were inferior to those for the IgG, and kidney uptake was relatively high even with D-lysine administration. The ability of [111In]DOTA-hLL2 to accurately predict [90Y]DOTA-hLL2 biodistribution was established. These preclinical findings demonstrate that [90Y]DOTA-(CDR-grafted) mAbs are suitable for examination in clinical RAIT.

The effect of exercise intensity on the slow component of VO2 in persons of different fitness levels

OBJECTIVES

To evaluate the slow component of VO2 in persons of different fitness levels exercising at different intensities and the contribution of proposed mediators to the slow component of VO2 using equations from the literature.

EXPERIMENTAL DESIGN

Cross-sectional.

SETTING

University.

PARTICIPANTS

Low (N = 15) and high (N = 15) fitness (VO2max of 37 vs 62 ml.min-1.kg-1).

INTERVENTIONS

None.

MEASURES

Each subject completed, in random order, a series of 12 min cycle ergometer exercise trials corresponding to 50, 60, 70 and 80% of VO2max. VO2, minute ventilation (MV), blood lactate (BL), rectal temperature (RT), heart rate and blood pressure were measured.

RESULTS

There was a significant (p < 0.05) increase in the slow component of VO2 for each level of fitness across time and at each workrate. There were no between group differences for any variable. The increase in the slow component of VO2 ranged from 70 ml.min-1 for the lighter workrates to 543 ml.min-1 for the high fitness group at 80% of maximal VO2 (both p < 0.05). The oxygen cost of MV, RT and rate pressure product accounted for about 50% of the observed increase in the slow component of VO2. MV appears to increase in a pattern most similar to the slow component of VO2 and the oxygen cost of MV generally accounted for the highest percentage of the observed increase.

CONCLUSIONS

The slow component of VO2 needs to be considered when prescribing exercise. These results are not conclusive concerning the primary mediators of the slow component of VO2.

Management of dyslipidemia in adults

The importance of treating dyslipidemias based on cardiovascular risk factors is highlighted by the National Cholesterol Education Program guidelines. The first step in evaluation is to exclude secondary causes of hyperlipidemia. Assessment of the patient's risk for coronary heart disease helps determine which treatment should be initiated and how often lipid analysis should be performed. For primary prevention of coronary heart disease, the treatment goal is to achieve a low-density lipoprotein (LDL) cholesterol level of less than 160 mg per dL (4.15 mmol per L) in patients with only one risk factor. The target LDL level in patients with two or more risk factors is 130 mg per dL (3.35 mmol per L) or less. For patients with documented coronary heart disease, the LDL cholesterol level should be reduced to less than 100 mg per dL (2.60 mmol per L). A step II diet, in which the total fat content is less than 30 percent of total calories and saturated fat is 8 to 10 percent of total calories, may help reduce LDL cholesterol levels to the target range in some patients. A high-fiber diet is also therapeutic. The most commonly used options for pharmacologic treatment of dyslipidemia include bile acid-binding resins, HMG-CoA reductase inhibitors, nicotinic acid and fibric acid derivatives. Other possibilities in selected cases are estrogen replacement therapy, plasmapheresis and even surgery in severe, refractory cases.

The effects of long-term, moderate intensity, intermittent exercise on aerobic capacity, body composition, blood lipids, insulin and glucose in overweight females

OBJECTIVE

To test the hypotheses that the accumulation of 30 min of moderate intensity, intermittent exercise, 5d/week-1, for 32 weeks, will increase aerobic capacity, alter body composition and improve blood lipids, insulin and glucose. Secondly, to identify individuals who may respond to moderate intensity, intermittent exercise.

SUBJECTS

Thirteen sedentary, moderately obese females, aged 43 +/- 11 (y), body mass index (BMI) 32.7 +/- 7.7 (kg/M2), body fat 40.6 +/- 8.8 (%), VO2max 24.0 +/- 4.6 (ml/kg-1/min-1).

MEASUREMENTS

Aerobic capacity, body composition, blood lipids, fasting insulin and glucose, energy intake.

RESULTS

Group data showed no significant changes for aerobic capacity, body composition, blood lipids, insulin or glucose. However, 7 of the 13 subjects increased aerobic capacity, lost fat weight and improved insulin. Adherence to the exercise regimen was excellent with 82.6 +/- 10.0% of the exercise completed.

CONCLUSIONS

Moderate intensity, intermittent exercise for a total of 30 min, 5d/week,-1 for 32 weeks duration, was not a sufficient stimulus to significantly increase aerobic capacity, and alter weight, body composition or improve blood lipids, insulin or glucose for the entire group. However, those subjects who increased aerobic capacity and decreased fat weight were significantly older, had lower maximal aerobic capacity and greater body fat at baseline compared to the six subjects who did not increase aerobic capacity and decrease fat weight. For both groups, moderate intensity, intermittent exercise showed excellent adherence and this may be a useful model for future research studies.

Differences in myocardial velocity gradient measured throughout the cardiac cycle in patients with hypertrophic cardiomyopathy, athletes and patients with left ventricular hypertrophy due to hypertension

OBJECTIVES

We sought to compare the myocardial velocity gradient (MVG) measured across the left ventricular (LV) posterior wall during the cardiac cycle between patients with hypertrophic cardiomyopathy (HCM), athletes and patients with LV hypertrophy due to systemic hypertension and to determine whether it might be used to discriminate these groups.

BACKGROUND

The MVG is a new ultrasound variable, based on the color Doppler technique, that quantifies the spatial distribution of transmyocardial velocities.

METHODS

A cohort of 158 subjects was subdivided by age into two groups: Group I (mean [+/-SD] 30 +/- 7 years) and Group II (58 +/- 8 years). Within each group there were three categories of subjects: Group Ia consisted of patients with HCM (n = 25), Group Ib consisted of athletes (n = 21), and Group Ic consisted of normal subjects; Group IIa consisted of patients with HCM (n = 19), Group IIb consisted of hypertensive patients (n = 27), and Group IIc consisted of normal subjects (n = 33).

RESULTS

The MVG (mean [+/-SD] s-1) measured in systole was lower (p < 0.01) in patients with HCM (Group Ia 3.2 +/- 1.1; Group IIa 2.9 +/- 1.2) compared with athletes (Group Ib 4.6 +/- 1.1), hypertensive patients (Group IIb 4.2 +/- 1.8) and normal subjects (Group Ic 4.4 +/- 0.8; Group IIc 4.8 +/- 0.8). In early diastole, the MVG was lower (p < 0.05) in patients with HCM (Group Ia 3.7 +/- 1.5; Group IIa 2.6 +/- 0.9) than in athletes (Group Ib 9.9 +/- 1.9) and normal subjects (Group Ic 9.2 +/- 2.0; Group IIc 3.6 +/- 1.5), but not hypertensive patients (Group IIb 3.3 +/- 1.3). In late diastole, the MVG in patients with HCM (Group Ia 1.3 +/- 0.8; Group IIa 1.4 +/- 0.8) was lower (p < 0.01) than that in hypertensive patients (Group IIb 4.3 +/- 1.7) and normal subjects (Group IIc 3.8 +/- 0.9). An MVG < or = 7 s-1, as a single diagnostic approach, differentiated accurately (0.96 positive and 0.94 negative predictive value) between patients with HCM and athletes when the measurements were taken during early diastole.

CONCLUSIONS

In both age groups, the MVG was lower in both systole and diastole in patients with HCM than in athletes, hypertensive patients or normal subjects. The MVG measured in early diastole in a group of subjects 18 to 45 years old would appear to be an accurate variable used to discriminate between HCM and hypertrophy in athletes.

Energy and macronutrient consumption of elementary school children served modified lower fat and sodium lunches or standard higher fat and sodium lunches

OBJECTIVE

To determine the energy and macronutrient consumption of elementary school children served modified lower fat and sodium or typical higher fat and sodium school lunches.

DESIGN

The intervention school received lunches with < 30% of energy from fat and < 1000 mg sodium. The control school received typical lunches with 35% of energy from fat and > 1000 mg sodium. Served lunches were analyzed from menus and consumed lunches were analyzed using USDA plate waste methodology.

SUBJECTS

Eighty intervention and 80 control subjects matched for ethnicity and economic status.

RESULTS

Intervention school menus were significantly lower for energy, sodium, and fat compared to the control school. From analysis of plate waste, children from both schools consumed approximately 25% less energy than served (p < 0.05). Consumption of fat as a percentage of total energy and consumption of sodium was significantly less for the intervention compared to the control school. Compensation for the lower fat meals by the intervention school children (eating greater portions of high fat items) was not evident as the percentage of energy from fat consumed was only 1.3% greater than the percentage which was served.

CONCLUSIONS

Lunch meals in this study were consumed as served. Intervention school children served lower fat and sodium meals consumed less fat and sodium than control school children and did not selectively eat only higher fat and sodium items.

Nutrition and physical activity program to attenuate obesity and promote physical and metabolic fitness in elementary school children

Obesity and low levels of physical and metabolic fitness are risk factors for cardiovascular disease and diabetes. The purpose of this investigation was to attenuate obesity and improve physical and metabolic fitness in elementary school children. Schools have the opportunity, mechanisms, and personnel in place to deliver nutrition education, fitness activities, and a school food service that is nutritious and healthy. Cohorts from grades 3 to 5 in two school districts in rural Nebraska (Intervention/Control) participated in a 2-year study of physical activity and modified school lunch program. Data collection for aerobic capacity, body composition, blood chemistry, nutrition knowledge, energy intake, and physical activity was at the beginning and end of each year. Int received enhanced physical activity, grade specific nutrition education, and a lower fat and sodium school lunch program. Con continued with a regular school lunch and team sports activity program. At year 2, Int lunches had significantly less energy (9%), fat (25%), sodium (21%), and more fiber (17%). However, measures of 24-hour energy intake for Int and Con showed significant differences for sodium only. Physical activity in the classroom was 6% greater for Int compared to Con (p < 0.05) but physical activity outside of school was approximately 16% less for Int compared to Con (p < 0.05). Body weight and body fat were not different between schools for normal weight or obese children. No differences were found for cholesterol, insulin, and glucose; however, HDL cholesterol was significantly greater and cholesterol/HDL was significantly less for Int compared to Con (p < 0.05). It appears that compensation in both energy intake and physical activity outside of school may be responsible for the lack of differences between Int and Con.

Prescription of exercise intensity for the obese patient: the relationship between heart rate, VO2 and perceived exertion

OBJECTIVE

It has been suggested that relative heart rate reserve (% HRR), relative oxygen uptake (% VO2peak), and rating of perceived exertion (RPE) can be used interchangeably to prescribe exercise intensity. The purpose of this study was to examine the relationship between % HRR, % VO2peak, and RPE in obese females prior to and following substantial weight loss.

SUBJECTS

122 obese females (% Body fat = 45.9 +/- 5.0%) who participated in a weight loss intervention program.

METHOD

Functional aerobic capacity was measured at baseline and following 12 weeks of exercise training and weight loss using a multi-stage Modified Balke treadmill protocol. The VO2, heart rate (HR), and RPE were measured at each stage, with VO2 and HR data converted to the percentages of the peak levels attained. These multi-stage data were then analyzed using mixed-model regression procedures to examine the relationship between % HRR, % VO2, and RPE.

RESULTS

With RPE as the dependent variable, results indicated that % HRR and % VO2, corresponded to RPE values consistent with existing guidelines (70% = 13-14 RPE), and this was true for analyses performed at baseline and following weight loss. Further, baseline results indicated that % HRR and % VO2 corresponded to similar levels of exercise intensity (40-70% HRR = 40-70% VO2peak). However, following weight loss, % HRR represented a higher level of intensity than its corresponding % VO2peak.

CONCLUSIONS

The results of this study suggest that RPE can be used as subjective marker of exercise intensity in an obese female population. However, despite adhering to existing guidelines prior to weight loss, there may be a discrepancy in the relationship between % HRR and VO2max following severe weight loss, possibly due to the decrease in resting HR following exercise training and weight loss. These findings directly impact the prescription and monitoring of exercise intensity for obese patients.

Influence of degree of obesity on loss of fat-free mass during very-low-energy diets

This study examined the influence of initial degree of obesity on loss of fat-free mass (FFM). One hundred twelve obese females participated in a series of very-low-energy diet (VLED) clinical trials. Obesity groups were determined by three common methods: percent body fat, body mass index, and weight. Within each group, subjects were classified into low-, intermediate-, and high-obesity groups. As expected, the high-obesity group lost comparable amounts or more weight and more fat weight than the low- and intermediate-obesity classifications for each group. The high-obesity group lost approximately 2% more FFM (P < 0.05) compared with the low and intermediate group when subjects were grouped by body mass index and weight and showed no differences between classifications when subjects were grouped by percent body fat. No differences were found between classifications for ratios of FFM to weight loss regardless of how subjects were grouped. Thus, the degree of obesity does not seem to affect loss of FFM.

Very low calorie diet with concurrent versus delayed and sequential exercise

Obese females undergoing very-low-calorie diet (VLCD) were studied for 12 weeks to determine the effects of concurrent vs delayed and sequential exercise. Subjects were assigned to one of six groups: control (C) n = 28; endurance exercise (EE) n = 18; weight training (WT) n = 26; endurance exercise plus weight training (EEWT) n = 21; control for 4 weeks with subsequent EE (C4EE) n = 10; WT for 4 weeks with sequential EE (WT4EE) n = 12. EE was performed 3 days a week using five weight lifting exercises. Loss in body weight did not differ between groups. Expressed as a ratio of fat-free mass (FFM) to weight loss WT4EE showed a 8.1%, 9.7%, and 11.4% difference compared to EE, C4EE, and C, respectively (P < 0.05). WT4EE also showed significant increases from baseline of 8.2% in aerobic capacity (L/min) and 12.5% in the strength index (SI/kg FFM). WT4EE showed the smallest decrease of all groups in resting metabolic rate of 6.1% of the baseline value; however, this decrease was significant. Although WT4EE showed some favorable changes from baseline, the magnitude of the changes between groups was small. There were no significant differences found between C4EE and the other study groups. Thus, the delay or sequential use of exercise during VLCD provided only small differences for WT4EE compared to the other groups and any clinical significance for the individual is presently unknown.

Muscle hypertrophy with large-scale weight loss and resistance training

The combined effects of exercise and energy restriction on changes in body fat and fat-free mass (FFM) are controversial. This study was conducted to determine whether muscle hypertrophy is possible during weight loss. Fourteen obese females received a 3360-kJ/d liquid diet for 90 d. Seven subjects received a weight training (WT) regimen and seven subjects remained sedentary (C). Biopsy samples were obtained from the vastus lateralis muscle at baseline and after 90 d of treatment. The average weight loss over the 90-d period was 16 kg with approximately 24% of the weight loss from FFM and 76% from fat. The amount and composition of the weight loss did not differ between WT and C groups. The cross-sectional area of slow twitch and fast twitch fibers was unchanged by treatment in C subjects but significantly increased in WT subjects. It appears that weight training can produce hypertrophy in skeletal muscle during severe energy restriction and large-scale weight loss.

Association between blood lipids and different measures of body fat distribution: effects of BMI and age

The waist-to-hip ratio (WHR) and the waist circumference have been correlated with blood lipid parameters. However, both the WHR and the waist circumference have been measured in numerous ways by researchers, and it appears that standardization of the anatomical sites used in this measurement is necessary. The present study investigated the associations between five different WHR measurements and blood lipid parameters across age and BMI. Three hundred and twenty-four (324) males were assessed for cholesterol, HDL, LDL, VLDL, cholesterol/HDL ratio, and triglycerides. The waist was identified by three different sites which included the midpoint between the lower rib and iliac crest (ABAB), level of the umbilicus (UMB), and iliac crest (IC). The hip was measured at both the iliac crest (IC) and the greatest girth at the gluteus (GL). A total of five WHRs were calculated from these anatomical measurements. Partial correlation coefficients, controlling for age and BMI, indicated that the ABAB/GL, UMB/GL, ABAB and UMB have the greatest association with all of the blood lipid parameters examined (P < 0.05). However, after stratifying by BMI, partial correlations controlling for age indicated that these significant relationships are only present in the upper quartile of the BMI distribution, indicating that obesity is necessary for these relationships to exist. In addition, risk classification varied according to the WHR which was used. The results indicate that the ABAB/GL, UMB/GL, ABAB and UMB are similar for the prediction of blood lipid parameters. However, the ABAB/GL and ABAB may be the preferred methods because of the consistency in locating the necessary anatomical landmarks.(ABSTRACT TRUNCATED AT 250 WORDS)

Estimation of peak oxygen consumption from a sub-maximal half mile walk in obese females

This study compared peak oxygen consumption estimated from a half mile sub-maximal walk test with oxygen consumption determined from a maximal treadmill test with 96 obese females. A half mile walk was completed as quickly as possible without running. Retests on 71 subjects were completed to determine the reliability of the half mile walk. Hearts rates were obtained for 15 s immediately upon completion of the walks. Stepwise regression to estimate peak VO2 was used with the following variables: walk time (TM), body weight, height, BMI, age, and heart rate (HR). The best equation was peak VO2 (ml/kg/min) = 53.23 - (1.98 x TM) - (0.32 x BMI) - (0.08 x age), r = 0.76, s.e.e. = 2.89 ml/kg/min. The mean difference between determined and estimated peak VO2 in a cross-validation group of subjects who were not included in the validation group was 0.15 ml/kg/min (n.s.), r = 0.77, s.e.e. = 3.01 ml/kg/min, E = 3.09. Reliability for time to complete the half mile walk was r = 0.87 with 0.1 min difference (n.s.). This study indicated the half mile walk to provide an accurate, reliable estimate of peak VO2 which should be useful in the clinical setting.

Strength changes induced by extreme dieting and exercise in severely obese females

Strength changes, induced by very low-calorie diet (VLCD, 520 kcal/day) alone and in combination with exercise, were determined in 109 severely obese females (46.8 +/- 4.69% fat). Experimental treatments included VLCD alone (LC, n = 40), VLCD with endurance exercise (EE, n = 23), VLCD with endurance exercise and resistance strength training (EERST, n = 23), and VLCD with resistance strength training (RST, n = 23). All subjects participated in the study for 90 days while EE, EERST, and RST exercised four times/week according to specified schedules. Results indicated significant differences for the change scores (baseline to 90 days) for bench press, knee flexion, upper body and lower body composite strength scores between RST and all other groups. RST was the only treatment that increased upper and lower body strength. No differences between groups were found for body mass losses, decrease in percent fat and fat mass. In contrast, these variables showed significant change scores for all groups. Decreases in fat-free mass (FFM) were 5.18 +/- 3.40 kg, 4.79 +/- 4.15 kg (p = 0.001), 4.64 +/- 4.23 kg, and 3.26 +/- 2.67 kg for EE, LC, RST, and EERST, respectively. These data suggest that the combination of resistance strength training and VLCD increases strength despite a loss of FFM. However, endurance exercise and VLCD do not seem to affect body mass loss or FFM loss per se. Moreover, it seems that these increases in strength may represent a training effect which might imply improved central neuromuscular function rather than muscular hypertrophy since FFM decreased in all groups.

Pregnancy outcome and Ebstein's anomaly

BACKGROUND

Ebstein's anomaly is an uncommon congenital cardiac abnormality that may be associated with cyanosis and arrhythmias. For those female patients with the anomaly who survive to adult life there is little information available about pregnancy, maternal complications, and fetal outcome. This study was designed to address this issue so that these patients can receive appropriate advice and management.

METHODS AND RESULTS

Forty two pregnancies in 12 women with Ebstein's anomaly were studied. The mothers' cardiac lesions were assessed on the basis of symptoms, the presence of cyanosis or arrhythmia, and by echocardiographic grading of severity. In the absence of important maternal cyanosis or arrhythmia, pregnancy was well tolerated. Neonatal outcome was good though there was an increased risk of prematurity and dysmaturity in the babies born to mothers with cyanosis.

CONCLUSIONS

This study indicates that women with Ebstein's anomaly who reach child-bearing age can be advised that pregnancy is likely to be well tolerated with good fetal outcome. Maternal arrhythmia or cyanosis are indications for closer maternal and fetal observation.

Diet and body composition. Effect of very low calorie diets and exercise

Obesity is the presence of excess body fat and is associated with a variety of medical conditions which increase morbidity and mortality. Millions of individuals participate in weight-reduction programmes which include reduced calorie diets and may also include exercise. Very low calorie diets (VLCD) of 400 to 800 kcal/day appear attractive as they generally show an increase in weight loss from 0.2 to 0.5 kg/week found with the traditional diet to 1.5 to 2.0 kg/week. Early use of very low calorie diets with poor quality protein and loose medical supervision resulted in about 60 deaths, many of which were attributed to loss of lean body mass and in particular, cardiac muscle atrophy. Although current very low calorie diets are presumed safe, concern regarding preservation of lean body mass (LBM) remains. Investigators have used exercise to slow the depletion of lean body mass during very low calorie diets; however, the results are not conclusive. A host of different methodologies and questionable documentation and design of exercise protocols precludes a definitive statement for the benefits of exercise during very low calorie diets for the purpose of LBM retention.

Effects of a very-low-calorie diet and physical-training regimens on body composition and resting metabolic rate in obese females

Sixty-nine obese females received 90 d of a liquid diet providing 2184 kJ/d in clinical trials. Groups were diet only (C), diet plus endurance exercise (EE), diet plus weight training (WT), or diet plus endurance exercise and weight training (EEWT). Changes in body weight, percent fat, fat weight, and fat-free mass were not different between groups. Declines in resting metabolic rate (RMR) were approximately 7% to approximately 12% of baseline values with no differences among groups. A significant increase in work capacity (approximately 16%) was shown for EEWT. Strength index showed declines of approximately 6% for C and EE and gains of approximately 3% and approximately 10% for EEWT and WT, respectively. These clinical trials did not show advantages of any exercise regimen over diet alone for weight loss, body-composition changes, or declines in RMR. Improvements in work capacity were limited and strength improved in groups that participated in strength training.

Comparison between two methods of hydrostatic weighing without head submersion in morbidly obese females

This study compared two methods of hydrostatic weighing without head submersion to conventional hydrostatic weighting in morbidly obese females. We concluded that hydrostatic weighing without head submersion is a valid alternative to conventional hydrostatic weighing especially when subjects are apprehensive in the water. The use of anthropometric head measures (HWNS-A) did not significantly improve the accuracy of the body composition assessment; therefore, elimination of these time consuming measurements in favor of the direct correction of head above Db is recommended.

Criteria to verify attainment of maximal exercise tolerance test with obese females

This study compared criteria used to determine attainment of maximal ETT used with normal subjects to results shown by obese subjects. Results indicated that obese subjects do not show the values that normal subjects show for plateau in oxygen consumption, respiratory exchange ratio, predicted maximal heart rate, or perceived exertion. Generally, less than 60% of the obese subjects met criteria for maximal ETT. These findings suggest that alternate criteria and/or alternate testing are needed to ascertain that ETT was maximal. Suggestions include longer treadmill stage times and the use of blood lactate.

Hydrostatic weighing without head submersion in morbidly obese females

This study tests the validity of hydrostatic weighing without head submersion (HWNS) for determining the body density (Db) of morbidly obese (MO) females. Eighty MO females who were able to perform traditional hydrostatic weighing at residual volume (HW) underwent four counterbalanced trials for each procedure (HW and HWNS) to determine Db. Residual volume was determined by oxygen dilution. Twenty subjects were randomly excluded from the experimental group (EG) and assigned to a cross-validation group (CV). Simple linear regression was performed on EG data (n = 60, means = 36.8 y, means % fat = 50.1) to predict Db from HWNS (Db = 0.569563 [Db HWNS] + 0.408621, SEE = 0.0066). Comparison of the predicted and actual Db for CV group yielded r = 0.69, SEE = 0.0066, E statistic = 0.0067, mean difference = 0.0013 kg/L. The SEE and E statistic for body fat were 3.31 and 3.39, respectively. Mean difference for percent fat was 0.66%. Results indicate that HWNS is a valid technique for assessing body composition in MO females.

Inadequate parental understanding of asthma medications

The parents of 128 children with asthma were interviewed about their knowledge of asthma medications. Simple understanding of the modes of action of these drugs was present in only 42.2% (for beta 2-agonists), 12.1% (methylxanthines), 11.7% (cromoglycate), 0% (inhaled corticosteroids), and 3.6% (oral corticosteroids) of parents. Simple understanding of when to use these drugs was present in 13.4% (beta 2-agonists), 4% (methylxanthines), 50% (cromoglycate), 47.1% (inhaled corticosteroids), and 0% (oral corticosteroids). Some understanding of the side effects was observed in 51.6% (beta 2-agonists), 40.4% (methylxanthines), 10% (cromoglycate), 5.9% (inhaled corticosteroids), and 25% (oral corticosteroids). Poor parental knowledge about the pharmacology of asthma was underlined by the inclusion of antibiotics, antihistamines, and decongestants as medications used in asthma. This study also uncovered the continuing misuse of compound methylxanthine preparations and non-selective sympathomimetics in a small percentage of patients.

Nutrition education and social learning interventions for type II diabetes

Two diabetes education programs were compared to a control condition. Seventy-eighty type II (non-insulin-dependent) diabetic outpatients were randomly assigned to nutrition education, nutrition education plus social learning intervention, or wait-list control conditions. Both interventions involved five weekly meetings that focused on reducing calorie intake, increasing dietary fiber, and decreasing fat consumption. The social learning condition also included individualized goal setting and feedback and training in problem-solving and relapse prevention. Within-group analyses and between-group comparisons generally revealed greater improvement in targeted goals (e.g., calorie intake, fat reduction) among intervention conditions than the control condition. There were few differences in more distal measures of outcome such as weight or glycosylated hemoglobin. The social learning component did not improve outcome more than the nutrition education program. Possible reasons for the observed findings and the advantages and limitations of focused time-limited diabetes education efforts are discussed.

Hydrostatic weighing without head submersion: description of a method

Hydrostatic weighing (HW) was performed at residual volume (RV) and total lung capacity without head submersion (TLCNS). Ninety-five males (25.6 +/- 4.9 yr) and 87 females (22.6 +/- 5.2 yr) were studied at two laboratory sites using identical protocols. Twenty males and 20 females were separated from the original group and randomly assigned to cross-validation groups. RVs were determined by the oxygen dilution method. Vital capacity was determined with the subject submerged in water to the shoulders. Underwater weight was determined using 10 trials at RV and 5 trials at TLCNS, with the order of methods randomly assigned. Regression analysis provided an equation to predict body density (pDb) at RV from body density (Db) at TLCNS. The equation for males was pDb (HW at RV) = 0.5829 (DbHW at TLCNS) + 0.4059, r = 0.88, SEE = 0.0067. The equation for females was pDb (HW at RV) = 0.4745 (DbHW at TLCNS) + 0.5173, r = 0.85, SEE = 0.0061. Cross-validation showed no significant differences using Db from HW at RV (males = 1.0626 g.ml-1, females = 1.0493 g.ml-1 and pDb from HW at TLCNS (males = 1.0625 g.ml-1, females = 1.0479 g.ml-1). The correlation coefficient SEE and total error for males were r = 0.95, 0.0043, and 0.0041, respectively and for females r = 0.82, 0.0084, and 0.0085, respectively. Mean percent fat for RV and TLCNS was identical for males and differed by 0.7% for females. Test-re-test data indicated the TLCNS procedure was reliable (r = 0.98).(ABSTRACT TRUNCATED AT 250 WORDS)

Guidelines for maintenance treatment of childhood asthma: development of a score card system by multivariate cluster analysis

Multivariate cluster analysis of data on 128 asthmatic children resulted in the identification of 8 major discriminating variables. Stepwise divisions by this computer programme resulted in the formation of 6 grades of severity. There was significant correlation between higher grades of severity and early onset of the disease (P less than 0.02). There was also significant correlation between higher grades of severity and greater use of interval medications (P less than 0.002). However, 27.3% were receiving inadequate interval medications in respect of their grade of severity. Assignation of a 5-point scale to each of the 8 major discriminating variables resulted in the generation of computer-designated scores commensurate with each grade of severity. This was coupled to current recommendations for stepwise maintenance medications appropriate for each grade. This Score Card system for maintenance management of childhood asthma may prove useful in busy clinical settings.

Parental perceptions and attitudes toward asthma and its treatment: a controlled study

We compared the attitudes of parents of 128 asthmatic children with those of 110 control children. The majority of both groups of parents had negative perceptions of the impact of asthma on children, but control parents were significantly more pessimistic. Control parents were also significantly more pessimistic than asthma parents about the impact of asthma on family lifestyle and relationships. In contrast, both groups were remarkably concordant in their ambivalence towards compliance with medication, recognising the necessity and efficacy of drug therapy, and yet worried about its long term effects on children. Both groups were also concordant in their readiness to give up household pets but not cigarette smoking for the sake of asthmatic children. Physician awareness of parental and community perceptions of childhood asthma may contribute to improved compliance with medications.

Chronologic analysis of variations in retinal damage in two strains of rats after short-term illumination

In order to determine whether an optimal period existed for evaluating retinal photodamage in rats, a chronologic analysis was made of quantifiable changes in the outer nuclear layer (ONL) and retinal thicknesses in Sprague-Dawley (SD) and Wag/Rij rats after a single, 24 hr exposure to fluorescent light. A gradual reduction in ONL and retinal thicknesses occurred between postexposure days 0 and 10 and appeared to stabilize by day 14 in both strains. The percent difference in both ONL and retinal thickness in unexposed and exposed rats was greater in Wag/Rij than in SD rats. That the superior hemisphere of the retina was more susceptible to photodamage than the inferior was substantiated, and the difference was greater in the Wag/Rij than in SD rats. This finding emphasizes a significant variability between rat strains and is possibly a manifestation of the slowly progressing genetic retinopathy in the Wag/Rij rats. Results indicated that the optimal period for assessing photodamage under these experimental conditions was not sooner than 10 to 14 days after exposure. Quantifiable analyses prior to that time would not provide an accurate evaluation of the total influence of a short-tern exposure period.

Antagonistic effects of adrenalectomy and ether/surgical stress on light-induced photoreceptor damage

Light-induced damage to retinal photoreceptors in influenced by the endocrine status of the animal during the period of exposure. Experimental manipulation of the pituitary gland and of prolactin levels has been shown to affect retinal damage in rats exposed to visible light. When rats are experimentally stressed, prolactin secretion from the pituitary gland occurs as does secretion of adrenocorticotropic hormone (ACTH), which stimulates the release of adrenal cortical hormones. Since prolactin appears to influence retinal damage and since stressed animals have increased serum levels of prolactin, a comparison of photoreceptor damage in animals in which the adrenal glands were removed or which had been experimentally stressed was undertaken in this study. Adrenalectomized rats had thicker outer nuclear layer (ONL) measurements than those found in sham-operated animals. Stressed rats had severely damaged retinas with cystic degeneration and significantly reduced ONL thickness measurements as compared to retinas of unstressed and adrenalectomized rats. Therefore hormones of the pituitary-adrenal system appear to be involved in the damage to the retina by light, and this response may be related to an interaction or synergism between the adrenal gland, stress, and prolactin secretion.