Validation of the use of Actigraph GT3X accelerometers to estimate energy expenditure in full time manual wheelchair users with spinal cord injury.

STUDY DESIGN: Cross-sectional validation study. OBJECTIVES: The goals of this study were to validate the use of accelerometers by means of multiple linear models (MLMs) to estimate the O2 consumption (VO2) in paraplegic persons and to determine the best placement for accelerometers on the human body. SETTING: Non-hospitalized paraplegics' community. METHODS: Twenty participants (age=40.03 years, weight=75.8 kg and height=1.76 m) completed sedentary, propulsion and housework activities for 10 min each. A portable gas analyzer was used to record VO2. Additionally, four accelerometers (placed on the non-dominant chest, non-dominant waist and both wrists) were used to collect second-by-second acceleration signals. Minute-by-minute VO2 (ml kg(-1) min(-1)) collected from minutes 4 to 7 was used as the dependent variable. Thirty-six features extracted from the acceleration signals were used as independent variables. These variables were, for each axis including the resultant vector, the percentiles 10th, 25th, 50th, 75th and 90th; the autocorrelation with lag of 1 s and three variables extracted from wavelet analysis. The independent variables that were determined to be statistically significant using the forward stepwise method were subsequently analyzed using MLMs. RESULTS: The model obtained for the non-dominant wrist was the most accurate (VO2=4.0558-0.0318Y25+0.0107Y90+0.0051YND2-0.0061ZND2+0.0357VR50) with an r-value of 0.86 and a root mean square error of 2.23 ml kg(-1) min(-1). CONCLUSIONS: The use of MLMs is appropriate to estimate VO2 by accelerometer data in paraplegic persons. The model obtained to the non-dominant wrist accelerometer (best placement) data improves the previous models for this population.

Force normalization in paraplegics.

The principal aim of our study was the determination of the effectiveness of a standardized ratio, allometric scaling model and a gamma function model in normalizing the isometric torque data of spinal cord patients and healthy subjects. For this purpose we studied a sample of 21 healthy males and 23 spinal cord injury males. The experiment consisted of the measurement of the force of the upper limb movement executed by all the subjects. We also determined anthropometric variables with dual-energy x-ray absorptiometry. The experimental data were analyzed with 3 force normalization methods. Our results indicate that the most important confounding variable was the fat free mass of the dominant upper limb (r>0.36, p<0.05). With the standardization by body mass and allometric scaling model, the normalized torque was influenced by body size variables. However, the normalized torque by the gamma function model was independent of body size measures. Paraplegics were weaker (p<0.05) in extension movements when the data were normalized by the gamma function model. In summary, this study shows that the gamma function model with fat free mass of the dominant upper limb was more effective than the standardized ratio in removing the influence of body size variables.

Evaluation of CD7 and terminal deoxynucleotidyl transferase (TdT) expression in CD34+ myeloblasts from patients with myelodysplastic syndrome.

There is an emerging use of flow cytometry to evaluate patients with myelodysplastic syndrome (MDS). We have studied CD7 and TdT expression in the CD34+ myeloid blast cell population in 55 bone marrow samples of patients with MDS. CD7 and/or TdT were detected in 38 out of 55 patients (69%). CD7 expression was not related to other bad prognosis data but conversely, we found an association between TdT+ CD34 myeloblasts and high-risk MDS patients according to the International Prognostic Scoring System. Therefore, CD7 and TdT may help to establish the diagnosis of MDS and, TdT expression also seems to be a useful marker in distinguishing risk groups.

Results of a pilot study of 40 patients using high-dose therapy with hematopoietic rescue after standard-dose adjuvant therapy for high-risk breast cancer.

The study was designed to determine the toxicity, feasibility, and effectiveness of high-dose cyclophosphamide (6 g/m2), thiotepa (500 mg/m2) and carboplatin (800 mg/m2 (CTCb) with hematopoietic rescue as consolidation after standard-dose adjuvant chemotherapy treatment of primary high-risk breast cancer. From October 1991 to September 1994, 40 patients with stage II or III breast cancer involving 10 or more nodes were treated with CTCb after six cycles of adjuvant therapy with an anthracycline-containing regimen. Bone marrow (BM) was used as the source hematopoietic stem cell in the first 23 patients and G-CSF-mobilized peripheral blood progenitor cells (PBPC) in the other 17. No therapy-related deaths occurred, but three life-threatening Complications were recorded which resolved: bilateral pulmonary hemorrhage, veno-occlusive disease of the liver and pulmonary thromboembolism. PBPC result in faster hemopoietic reconstitution with significantly lower transfusion requirements. With a median follow-up of 35 months (23-59) actuarial event-free survival for the study patients at 3 years is 72% (CI 95%: 66-81%). Even in patients over 50-60 years, CTCb is a relatively well tolerated regimen which appears, after a median follow-up of nearly 3 years, to decrease relapse frequency as compared with historical series, although a definite role of HDT in the treatment of high-risk primary breast cancer needs confirmation in prospective randomized trials.