Estimating peak oxygen uptake in adolescents with cystic fibrosis.

OBJECTIVES: To predict peak oxygen uptake (VO2 peak) from the peak work rate (W peak) obtained during a cycle ergometry test using the Godfrey protocol in adolescents with cystic fibrosis (CF), and assess the accuracy of the model for prognostication clustering. METHODS: Out of our database of anthropometric, spirometric and maximal exercise data from adolescents with CF (N=363; 140 girls and 223 boys; age 14.77 ± 1.73 years; mean expiratory volume in 1 s (FEV1%pred) 86.82 ± 17.77%), a regression equation was developed to predict VO2 peak (mL/min). Afterwards, this prediction model was validated with cardiopulmonary exercise data from another 60 adolescents with CF (28 girls, 32 boys; mean age 14.6 ± 1.67 years; mean FEV1%pred 85.43 ± 20.01%). RESULTS: We developed a regression model VO2 peak (mL/min)=216.3-138.7 × sex (0=male; 1=female)+11.5 × W peak; R(2)=0.91; SE of the estimate (SEE) 172.57. A statistically significant difference (107 mL/min; p<0.001) was found between predicted VO2 peak and measured VO2 peak in the validation group. However, this difference was not clinically relevant because the difference was within the SEE of the model. Furthermore, we found high positive predictive and negative predictive values for the model for prognostication clustering (PPV 50-87% vs NPV 82-94%). CONCLUSIONS: In the absence of direct VO2 peak assessment it is possible to estimate VO2 peak in adolescents with CF using only a cycle ergometer. Furthermore, the regression model showed to be able to discriminate patients in different prognosis clusters based on exercise capacity.

Decreasing incidence and severity of cerebral palsy in prematurely born children.

OBJECTIVE: To examine incidence and severity of cerebral palsy (CP), and associated factors among preterm survivors (gestational age <34 weeks), admitted to a neonatal intensive care unit from 1990-2005. STUDY DESIGN: Eighteen antenatal, perinatal and postnatal factors were analyzed. The cohort was divided in four birth periods: 1990-1993 (n=661), 1994-1997 (n=726), 1998-2001 (n=723), and 2002-2005 (n=850). The Gross Motor Function Classification System was used as primary outcome measure (mean age: 32.9 ± 5.3 months). Logistic regression analyses were used. RESULTS: CP incidence decreased from 6.5% in period I, to 2.6%, 2.9% and 2.2% (P<.001) in period II-IV, respectively. Simultaneously, cystic periventricular leukomalacia (c-PVL) decreased from 3.3% in period I to 1.3% in period IV (P=.004). Within the total cohort (n=3287), c-PVL grade III decreased from 2.3% in period I to 0.2% in period IV (P=.003). The number of children with Gross Motor Function Classification System levels III-V decreased from period I to IV (P=.035). Independent risk factors for CP were c-PVL and severe intraventricular hemorrhage, whereas antenatal antibiotics, presence of an arterial line, Caesarean section, and gestational age were independent protective factors. CONCLUSION: CP incidence and severity decreased from 1990-1993 onward, which could be attributed to a reduction of 93% in severe c-PVL.

The Utrecht approach to exercise in chronic childhood conditions: the decade in review.

PURPOSE: To summarize and discuss current evidence and understanding of clinical pediatric exercise physiology focusing on the work the research group at Utrecht and others have performed in the last decade in a variety of chronic childhood conditions as a continuation of the legacy of Dr Bar-Or. KEY POINTS: The report discusses current research findings on the cardiopulmonary exercise performance of children (and adolescents) with juvenile idiopathic arthritis, osteogenesis imperfecta, achondroplasia, hemophilia, cerebral palsy, spina bifida, cystic fibrosis, and childhood cancer. Exercise recommendations and contraindications are provided for each condition. Implications for clinical practice and future research in this area are discussed for each of the chronic conditions presented. CLINICAL IMPLICATIONS: The authors provide a basic framework for developing an individual and/or disease-specific training program, introduce the physical activity pyramid, and recommend a core set of clinical measures to be used in clinical research.

Supramaximal verification of peak oxygen uptake in adolescents with cystic fibrosis.

PURPOSE: To study whether peak oxygen uptake ((Equation is included in full-text article VO2 peak), attained in traditional cardiopulmonary exercise testing (CPET) in adolescents with cystic fibrosis (CF), could be verified by a supramaximal exercise test. METHODS: Sixteen adolescents with CF (forced expiratory volume in 1 second as % of predicted [range, 45%-117%]) volunteered and successively performed CPET and a supramaximal test (Steep Ramp Test [SRT] protocol). RESULTS: Cardiopulmonary exercise testing and the SRT resulted in comparable cardiorespiratory peak values. We found no significant difference in oxygen uptake ((Equation is included in full-text article VO2 peak/kg) between CPET and the SRT (38.9 ± 7.4 and 38.8 ± 8.5 mL min kg, respectively; P = .81). We found no systemic bias for CPET and SRT measurements of (Equation is included in full-text article VO2 peak/kg and no differences between CPET and SRT (Equation is included in full-text article VO2 peak values within and between the maximal and non-maximal effort groups (P > .4). CONCLUSION: The (Equation is included in full-text article VO2 peak measured in CPET seems to reflect the true (Equation is included in full-text article.)O2 peak in adolescents with CF.

Development, feasibility and efficacy of a community-based exercise training program in pediatric cancer survivors.

OBJECTIVE: The aim of this study was to develop a 12-week exercise training program (comprising aerobic and strength exercises), and to study the feasibility and efficacy of this exercise program in children who survived acute lymphoblastic leukemia. SAMPLE AND METHODS: A 12-week exercise program was developed and tested for feasibility in nine children who survived cancer. RESULTS: From the 16 eligible children for the intervention, 9 participated, while 4 were able to complete the entire program. Feasibility of the program was scored by five children, two of them reported the program as being too demanding. The participating physiotherapists were satisfied with training methodology and training progress. The efficacy of the program on muscle strength, exercise capacity, functional mobility and fatigue showed no significant differences between pre and post training. CONCLUSION: In designing a community-based exercise training program, not only the stage of the disease needs to be considered, but more so the age of the children, the variety of exercises, the location of implementation and even more importantly the views and motivation of the parents concerning the execution of an exercise training program. A careful balance between these parameters could lead to a greater adherence and by that, to a better outcome of these programs.

Validation of a simple method for measuring cranial deformities (plagiocephalometry).

Craniofacial measuring is essential for diagnosis or evaluation of growth and therapies. Skull deformities in children are mainly caused by craniosynostosis or by external pressure in positional skull deformations. Traditional anthropometry does not sufficiently analyze craniofacial shape. In computed tomography (CT) scanning, radiation loads are considerable. Both CT and magnetic resonance imaging (MRI) scanning require anaesthesia in children for accurate imaging, due to their long acquisition time. This makes CT and MRI unsuitable for long term follow-up of pediatric patients unless there is a compelling reason. Other noninvasive three-dimensional (3D) surface scanners still have limited practical use. van Vlimmeren et al presented plagiocephalometry (PCM) as a simple and versatile instrument to quantify skull deformities with high intrarater and interrater reliability, but no comparison was made with the actual skull shape. At the Erasmus University Medical Center Rotterdam, Sophia Children's Hospital PCM was compared to 3D-CT scanning in 21 children with craniosynostosis early in life. The PCM ring proved to fit closely to the skin with mean differences less than 1 mm (P < 0.05). The shape of the PCM ring was not significantly changed when taken off the head (P > 0.05). Finally, no significant differences are shown between measurements on the skull (CT-scan) and PCM ring off the head (P > 0.05). This study proves that PCM is a reliable method for analysis of skull deformities. The measurements are in agreement with 3D-CT scanning as golden standard. Although only 2-dimensional measurements are performed by PCM, the combination of simplicity, reliability, and validity make it a promising tool for daily practice.

No deterioration in epilepsy and motor function in children with medically intractable epilepsy ineligible for surgery.

The aim of this study was to examine whether severity of epilepsy, motor functioning, and epilepsy-related restrictions change in children with medically intractable epilepsy who are ineligible for epilepsy surgery. The study was a prospective, longitudinal, 2-year follow-up of 28 children (14 females, 14 males). Their median age was 6 years 1 month (range 7mo-15y 4mo). Seizure types were: complex partial seizures (n=16), secondary generalized seizures (n=7), simple partial seizures (n=2), and mixed seizures (n=3). Severity of seizures, motor impairments, motor development, activities of daily life, and epilepsy-related restrictions were rated at baseline and 6, 12, and 24 months thereafter. Seizure severity did not change significantly, nor did muscle strength, range of motion, or muscle tone. Motor retardation was ubiquitous but did not increase in 20 children without spasticity. Motor function of eight children with spasticity improved (Gross Motor Function Measure: baseline 70.5 [SD 35.5]; 24 months later 81.6 [SD 29.6], p < 0.05) but remained below reference values in four children. In the entire group, functional skills increased and caregiver assistance lessened. Restrictions did not change significantly. We conclude that during a 2-year follow-up period, in children with medically intractable epilepsy who do not have surgical intervention, seizure severity does not deteriorate, motor impairments do not increase, motor development does not deflect negatively, and activities of daily living and restrictions do not worsen.

Cardiopulmonary exercise capacity, muscle strength, and physical activity in children and adolescents with achondroplasia.

OBJECTIVE: To study in children with achondroplasia the response to exercise and muscle strength compared with healthy peers and to describe the relation between exercise capacity, anthropometric factors, and physical activity. STUDY DESIGN: Patients (7 boys and 10 girls; mean age, 11.8 +/- 3.3 years) with achondroplasia performed a maximal treadmill exercise test. Anthropometric variables and muscle strength were measured and compared with the general population. The level of everyday physical activity was measured by using a diary. Functional ability was measured by using the Activity Scale for Kids. RESULTS: The exercise capacity of the children with achondroplasia was significantly reduced compared with reference values. All anthropometrical measurements differed significantly from reference values. There was a decrease in muscle strength in almost all muscle groups. We found a reduced physical activity level and impairments in functional ability. CONCLUSIONS: Cardiopulmonary exercise capacity and muscle strength in children with achondroplasia was reduced compared with reference values. Children with achondroplasia have a unique response to exercise. Clinicians should take these characteristic differences into account when the exercise capacity of subjects with achondroplasia is being tested.

Feasibility of preoperative inspiratory muscle training in patients undergoing coronary artery bypass surgery with a high risk of postoperative pulmonary complications: a randomized controlled pilot study.

OBJECTIVE: To determine in a pilot study the feasibility and effects of preoperative inspiratory muscle training in patients at high risk of postoperative pulmonary complications who were scheduled for coronary artery bypass graft surgery. DESIGN: Single-blind, randomized controlled pilot study. SETTING: University Medical Centre Utrecht, the Netherlands. SUBJECTS: Twenty-six patients at high risk of postoperative pulmonary complications were selected. INTERVENTION: The intervention group (N = 14) received 2-4 weeks of preoperative inspiratory muscle training on top of the usual care received by the patients in the control group. MAIN MEASURES: Primary outcome variables of feasibility were the occurrence of adverse events, and patient satisfaction and motivation. Secondary outcome variables were postoperative pulmonary complications and length of hospital stay. RESULTS: The feasibility of inspiratory muscle training was good and no adverse events were observed. Treatment satisfaction and motivation, scored on 10-point scales, were 7.9 (+/- 0.7) and 8.2 (+/- 1.0), respectively. Postoperative atelectasis occurred in significantly fewer patients in the intervention group than in the control group (kappa(2)(DF1) = 3.85; P = 0.05): Length of hospital stay was 7.93 (+/- 1.94) days in the intervention group and 9.92 (+/- 5.78) days in the control group (P = 0.24). CONCLUSION: Inspiratory muscle training for 2-4 weeks before coronary artery bypass graft surgery was well tolerated by patients at risk of postoperative pulmonary complications and prevented the occurrence of atelectasis in these patients. A larger randomized clinical trial is warranted.

Physical function and fitness in long-term survivors of childhood leukaemia.

OBJECTIVE: To evaluate the physical function and fitness in survivors of childhood leukaemia 5-6 years after cessation of chemotherapy. MATERIALS AND METHODS: Thirteen children (six boys and seven girls; mean age 15.5 years) who were treated for leukaemia were studied 5-6 years after cessation of therapy. Physical function and fitness were determined by anthropometry, motor performance, muscle strength, anaerobic and aerobic exercise capacity. RESULTS: On motor performance, seven of the 13 patients showed significant problems in the hand-eye co-ordination domain. Muscle strength only showed a significantly lower value in the mean strength of the knee extensors. The aerobic and the anaerobic capacity were both significantly reduced compared to reference values. CONCLUSION: Even 5-6 years after cessation of childhood leukaemia treatment, there are still clear late effects on motor performance and physical fitness. Chemotherapy-induced neuropathy and muscle atrophies are probably the prominent cause for these reduced test results. Physical training might be indicated for patients surviving leukaemia to improve fitness levels and muscle strength.

Preoperative intensive inspiratory muscle training to prevent postoperative pulmonary complications in high-risk patients undergoing CABG surgery: a randomized clinical trial.

CONTEXT: Postoperative pulmonary complications (PPCs) after coronary artery bypass graft (CABG) surgery are a major source of morbidity and mortality, and increase length of hospital stay and resource utilization. The prehospitalization period before CABG surgery may be used to improve a patient's pulmonary condition. The efficacy of preoperative inspiratory muscle training (IMT) in reducing the incidence of PPCs in high-risk patients undergoing CABG surgery has not yet been determined. OBJECTIVE: To evaluate the prophylactic efficacy of preoperative IMT on the incidence of PPCs in high-risk patients scheduled for elective CABG surgery. DESIGN, SETTING, AND PATIENTS: A single-blind, randomized clinical trial conducted at the University Medical Center Utrecht, Utrecht, the Netherlands, with enrollment between July 2002 and August 2005. Of 655 patients referred for elective CABG surgery, 299 (45.6%) met criteria for high risk of developing PPCs, of whom 279 were enrolled and followed up until discharge from hospital. INTERVENTION: Patients were randomly assigned to receive either preoperative IMT (n = 140) or usual care (n = 139). Both groups received the same postoperative physical therapy. MAIN OUTCOME MEASURES: Incidence of PPCs, especially pneumonia, and duration of postoperative hospitalization. RESULTS: Both groups were comparable at baseline. After CABG surgery, PPCs were present in 25 (18.0%) of 139 patients in the IMT group and 48 (35.0%) of 137 patients in the usual care group (odds ratio [OR], 0.52; 95% confidence interval [CI], 0.30-0.92). Pneumonia occurred in 9 (6.5%) of 139 patients in the IMT group and in 22 (16.1%) of 137 patients in the usual care group (OR, 0.40; 95% CI, 0.19-0.84). Median duration of postoperative hospitalization was 7 days (range, 5-41 days) in the IMT group vs 8 days (range, 6-70 days) in the usual care group by Mann-Whitney U statistic (z = -2.42; P = .02). CONCLUSION: Preoperative IMT reduced the incidence of PPCs and duration of postoperative hospitalization in patients at high risk of developing a pulmonary complication undergoing CABG surgery. TRIAL REGISTRATION: isrctn.org Identifier: ISRCTN17691887.

Effectiveness of exercise therapy: a best-evidence summary of systematic reviews.

The purpose of this project was to summarise the available evidence on the effectiveness of exercise therapy for patients with disorders of the musculoskeletal, nervous, respiratory, and cardiovascular systems. Systematic reviews were identified by means of a comprehensive search strategy in 11 bibliographic databases (08/2002), in combination with reference tracking. Reviews that included (i) at least one randomised controlled trial investigating the effectiveness of exercise therapy, (ii) clinically relevant outcome measures, and (iii) full text written in English, German or Dutch, were selected by two reviewers. Thirteen independent and blinded reviewers participated in the selection, quality assessment and data-extraction of the systematic reviews. Conclusions about the effectiveness of exercise therapy were based on the results presented in reasonable or good quality systematic reviews (quality score > or = 60 out of 100 points). A total of 104 systematic reviews were selected, 45 of which were of reasonable or good quality. Exercise therapy is effective for patients with knee osteoarthritis, sub-acute (6 to 12 weeks) and chronic (> or = 12 weeks) low back pain, cystic fibrosis, chronic obstructive pulmonary disease, and intermittent claudication. Furthermore, there are indications that exercise therapy is effective for patients with ankylosing spondylitis, hip osteoarthritis, Parkinson's disease, and for patients who have suffered a stroke. There is insufficient evidence to support or refute the effectiveness of exercise therapy for patients with neck pain, shoulder pain, repetitive strain injury, rheumatoid arthritis, asthma, and bronchiectasis. Exercise therapy is not effective for patients with acute low back pain. It is concluded that exercise therapy is effective for a wide range of chronic disorders.

Health-related quality of life and self-perceived competence of children assessed before and up to two years after epilepsy surgery.

PURPOSE: To measure outcome of epilepsy surgery in terms of health-related quality of life (HrQoL) and self-perceived competence of children and adolescents. METHODS: Prospective longitudinal follow-up study of 21 patients (aged 6.2 to 16.8 years). Frequency and severity of seizures and epilepsy-related restrictions, HrQoL, and self-perceived competence were rated before and 6, 12, and 24 months after epilepsy surgery. Data were analysed nonparametrically and using analysis of variance for repeated measures. RESULTS: Group-wise, seizure parameters had almost normalized 6 months after surgery (p<0.001) and remained so. Two years after surgery, 15 (72%) patients were free of seizures. At the first postsurgical assessment, parents and children evaluated the frequency of activities as improved and that of seizures as diminished (p<0.05). Parents evaluated their children as having positive emotions more frequently (p<0.05). Children started to feel better about seizure variables in the second year after surgery. Two years after surgery, children perceived themselves as being socially more competent and having greater self-worth (p=0.05). In the adolescent group, several aspects of self-perceived competence improved shortly after surgery (p<0.05), whereas 2 years after surgery, athletic competence and romance had improved (p<0.05). CONCLUSIONS: In children and adolescents, epilepsy surgery sets the stage for improvement in HrQoL and in competence to participate in social and societal domains. Most improvement occurs in the first 6 months after surgery.

Effects of anaerobic training in children with cystic fibrosis: a randomized controlled study.

BACKGROUND: Children's physical activity patterns are characterized by short-term anaerobic activities. Anaerobic exercise performance in children with cystic fibrosis (CF) has received little attention compared to aerobic performance. This study investigated the effects of anaerobic training in children with CF. DESIGN AND METHODS: Twenty patients were randomly assigned to the training group (TG) [11 patients; mean (+/- SD) age, 13.6 +/- 1.3 years; mean FEV(1), 75.2 +/- 20.7% predicted] or the control group (CG) [9 patients; mean age, 14.2 +/- 2.1 years; FEV(1), 82.1 +/- 19.1% predicted]. The TG trained 2 days per week for 12 weeks, with each session lasting 30 to 45 min. The training program consisted of anaerobic activities lasting 20 to 30 s. The control subjects were asked not to change their normal daily activities. Body composition, pulmonary function, peripheral muscle force, habitual physical activity, aerobic and anaerobic exercise performance, and quality of life were reevaluated at the end of the training program, and again after a 12-week follow-up period. RESULTS: Patients in the TG significantly improved their anaerobic performance, aerobic performance, and quality of life. No significant changes were seen in other parameters, and no improvements were found in CG. After the follow-up period, only anaerobic performance and quality of life in TG were significantly higher compared to pretraining values. CONCLUSIONS: Anaerobic training has measurable effects on aerobic performance (although not sustained), anaerobic performance, and health-related quality of life in children with CF. Therefore, anaerobic training could be an important component of therapeutic programs for CF patients.

Pediatric generalized joint hypomobility and musculoskeletal complaints: a new entity? Clinical, biochemical, and osseal characteristics.

OBJECTIVE: To describe the clinical features, osseal characteristics, and collagen biochemistry in children who attended our clinic with predominantly generalized hypomobility of the joints, in combination with musculoskeletal complaints or abnormal walking, and no known syndrome or known rheumatic, neurologic, skeletal, metabolic, or connective tissue disorder was present. METHODS: Nineteen children who attended the Children's Hospital of the University Medical Center Utrecht for generalized hypomobility of the joints (mean age: 11.6; standard deviation: 2.7), in combination with musculoskeletal complaints or abnormal walking as primary complaints (symptomatic generalized hypomobility [SGH]), were compared with an age-matched reference group of 284 healthy children with normal mobility of the joints. Anthropometrics, range of joint motion, muscle strength, exercise tolerance, motor development, quantitative ultrasound measurements of bone, and degradation products of collagen in urine were studied. Collagen modifications were determined in skin biopsies of 3 children and in hypertrophic scar tissue of another child, all with SGH. RESULTS: The range of joint motion was significantly decreased in almost all joints of all 19 children and after adjustment for age, gender, body weight, and height, significantly lower than that of the reference group (-108.3 degrees; 95% confidence interval [CI]: -136.9 to -79.8). Quantitative ultrasound measurements as well as urinary pyridinoline cross-link levels were, after adjustment for possible confounders, significantly lower in SGH children (broad-band ultrasound attenuation: -9.6 dB/MHz [95% CI: -17.4 to -1.9]; speed of sound: -25.0 m/s [95% CI: -39.7 to -10.3]; hydroxylysylpyridinoline: -50.1 micromol/mmol [95% CI: -87.6 to -12.6], lysylpyridinoline: -21.3 micromol/mmol [95% CI: -34.0 to -8.6]). An increased amount of pyridinoline cross-links per collagen molecule was observed in skin and hypertrophic scar tissue, in combination with increased amounts of collagen. CONCLUSION: SGH in children is considered a new clinical entity with specific clinical characteristics and might be related to an increased stiffness of connective tissue as a result of higher amounts of collagen with increased cross-linking.

Longitudinal determinants of peak aerobic performance in children with cystic fibrosis.

BACKGROUND: Several cross-sectional studies in patients with cystic fibrosis (CF) have shown that nutritional status and lung function are important determinants of peak aerobic capacity (peak oxygen uptake [O(2)peak]). In order to account for individual changes, the aim of this study was to determine the longitudinal relationship of changes in nutritional status, lung function, and O(2)peak in children with CF. DESIGN AND METHODS: Fat-free mass (FFM), lung function, and O(2)peak were assessed in 65 children with CF at baseline (mean +/- SD age, 10.5 +/- 2.9 years; mean FEV(1), 92.6 +/- 20.5%) and again 2 years later. FFM was calculated using skinfold thickness, and O(2)peak was measured using an incremental treadmill test for children < 12 years old or an incremental cycle ergometry test for children > or =12 years old. Lung function was measured before the exercise test. RESULTS: Over the 2-year study period, an increase was found for absolute values of FFM (6.1 kg, p < 0.001), FEV(1) (229 mL, p < 0.001), and O(2)peak (240 mL, p < 0.001), while a decrease was found for predicted values of FEV(1) (- 8.9%, p < 0.001) and O(2)peak (- 4.4%, p < 0.05). DeltaO(2)peak over the 2-year period best correlated with DeltaFEV(1) (r = 0.619, p < 0.001) and to a lesser degree with DeltaFFM (r = 0.506, p < 0.001). Multiple regression analysis demonstrated that DeltaFEV(1) and DeltaFFM explained 47% of the variation of the DeltaO(2)peak over the 2-year period. CONCLUSIONS: Our results show that longitudinal changes in O(2)peak are associated with changes in lung function and to a lesser extent with changes in nutritional status in children with CF. Special consideration should be given to exercise training and nutritional intervention, which might improve long-term clinical outcome in children with CF.

Prediction of postoperative pulmonary complications on the basis of preoperative risk factors in patients who had undergone coronary artery bypass graft surgery.

BACKGROUND AND PURPOSE: Pulmonary complications are among the most frequently reported complications after coronary artery bypass graft (CABG) surgery. However, the risks of postoperative pulmonary complications (PPCs) are not equal for all patients. The aim of this study was to develop a model, based on preoperative factors, for classifying patients with high and low risks for PPCs in order to implement tailored interventions. SUBJECTS AND METHODS: Postoperative pulmonary complications were examined in 117 adult patients who had undergone elective CABG surgery at the University Medical Centre Utrecht, Utrecht, the Netherlands. The presence of preoperative risk factors (N=12) that have been described in the literature was noted for each patient. A risk model was developed by use of logistic regression analysis. RESULTS: Preoperative risk factors for developing PPCs were an age of (>/=70 years, productive cough, diabetes mellitus, and a history of cigarette smoking. Protective factors against the development of PPCs were a predicted inspiratory vital capacity of (>/=75% and a predicted maximal expiratory pressure of (>/=75%. These risk and protective factors were included in the model (sensitivity=87% and specificity=56%), and a sum score for its clinical use was generated. DISCUSSION AND CONCLUSION: Six factors that can be determined easily before surgery, with need for only simple pulmonary testing, can provide a model for identifying patients at risk of developing PPCs after CABG surgery.