An evaluation of the reliability of time sampling versus continuous observation data collection

Thirty (10 male, 20 female) children, ages 41 to 71 months, were observed simultaneously in a freeplay setting by two observers using a validated assessment of physical activity in children (i.e. the FATS). One observer utilized a whole interval time sampling method of data recording and the second observer used a hand-held computer and continuously entered observations whenever a child's activity level changed, while the computer simultaneously calculated elapsed time (in tenths of seconds) spent in each behavioral category. Overall activity scores generated by the two approaches correlated 0.90 although the time sampling method produced lower estimates of physical activity. It is concluded that whole interval time sampling is a reliable cost-effective method of assessing physical activity levels in children and may be preferable to the continuous computer-assisted approach that was utilized.     

Results of minimally toxic nonmyeloablative transplantation in patients with sickle cell anemia and beta-thalassemia.

We describe previously transfused patients with sickle cell disease (n = 6) and thalassemia (n = 1) who received nonmyeloablative hematopoietic stem cell transplantation (HCT) to induce stable (full or partial) donor engraftment. Patients were 3 to 20 years (median, 9 years) old. All 7 received pretransplantation fludarabine and 200 cGy of total body irradiation; 2 patients also received horse antithymocyte globulin. Patients received bone marrow (n = 6) or peripheral blood stem cells (n = 1) from HLA-identical siblings, followed by a combination of mycophenolate mofetil and cyclosporine or tacrolimus for postgrafting immunosuppression. After nonmyeloablative HCT, absolute neutrophil counts were <0.5 x 10(9)/L and <0.2 x 10(9)/L for a median of 5 days (range, 0-13 days) and 0 days (range 0-13 days), respectively. A median of 0 (range, 0-9) platelet transfusions were administered. No grade IV nonhematologic toxicities were observed. One patient experienced grade II acute graft-versus-host disease. Two months after transplantation, 6 of 7 patients had evidence of donor chimerism (range, 25%-85%). Independent of red blood cell transfusions, these 6 patients initially had increased total hemoglobin and hemoglobin A concentrations and a reduction of reticulocytosis and transfusion requirements. There were no complications attributable to sickle cell disease during the interval of transient mixed chimerism. However, after posttransplantation immunosuppression was tapered, there was loss of the donor graft, and all patients experienced autologous hematopoietic recovery and disease recurrence. One patient did not engraft. The duration of transient mixed chimerism ranged from 97 to 441 days after transplantation in patients 4 and 6, respectively, and persisted until immunosuppressive drugs were discontinued after transplantation. In summary, the nonmyeloablative HCT regimens described here produced minimal toxicity and resulted in transient donor engraftment in 6 of 7 patients with hemoglobinopathies. Although complications from the underlying hemoglobinopathies did not occur during the period of mixed chimerism, these results suggest that stable (full or partial) donor engraftment after nonmyeloablative HCT is more difficult to achieve among immunocompetent pediatric patients with hemoglobinopathies than among adults with hematologic malignancies, perhaps in part because recipients may have been sensitized to minor histocompatibility antigens of their donor by preceding blood transfusions.     

Alarm settings for the Marquette 8000 pulse oximeter to prevent hyperoxic and hypoxic episodes

OBJECTIVE: To determine safe and appropriate alarm limits for the Marquette 8000 pulse oximeter to prevent hyperoxic and hypoxic episodes in neonates. It is necessary to define these limits for each brand of oximeter because of the variance in nonuser adjustable calibration algorithms used in pulse oximeters. METHODOLOGY: Oxygen saturation values obtained from a Marquette 8000 pulse oximeter (SpO2) were compared with simultaneous arterial blood gas PaO2 values obtained from blood gas analysis, for 322 samples in 24 consecutive neonates (median 30 weeks' gestation). RESULTS: In order to prevent 95% of hyperoxic episodes (PaO2 > 90 mmHg), the upper alarm limit was 95% SpO2. Similarly, to prevent 95% of hypoxic episodes (PaO2 < 40 mmHg), the lower alarm limit was 95% SpO2. A sensitivity lower than 95% had to be accepted to develop an alarm range which prevented both hyperoxic and hypoxic episodes. To maintain PaO2 values between 40 and 90 mmHg, an appropriate alarm range of 94-97% SpO2 (90% sensitivity, 28% specificity) was established. CONCLUSIONS: The relative merits of high sensitivity versus high specificity should be considered when determining appropriate alarm limits. Alarm limits which represent a balance between sensitivity and specificity will minimise false alarms and provide a clinically practical range. It would be useful for this type of information to be available for each brand of oximeter, to assist the user in determining appropriate alarm settings.     

Genetic implications and health consequences following the Chernobyl nuclear accident

Kozenko M, Chudley AE. Genetic implications and health consequences following the Chernobyl nuclear accident. It has been almost 25 years since the Chernobyl nuclear accident in Ukraine. We review relevant data derived from published reports originating in the Former Soviet Union. We cite census data from Ukraine and research studies from Western Europe that analyzed the effect of radiation on genetics and health outcome in the exposed populations. We also present philatelic materials that pictorially captured that fateful event in history.     

Treatment of vitiligo in children and adolescents by autologous cultured pure melanocytes transplantation with comparison of efficacy to results in adults

Background Transplantation of autologous cultured pure melanocytes is a well‐established procedure for the treatment of refractory and stabilized vitiligo. However, there was no report specifically comparing the efficacy with the regard to defined age groups (children‐adolescence‐adult). Objective We analysed the efficacy of this procedure in the treatment of vitiligo in children and adolescents and compare it with the results in adults treated during the same period and using identical procedures. Methods Melanocytes were isolated from the roof of suction blister, cultured and expanded with Hu16 medium in vitro, and transplanted to laser‐denuded receipt area. A total of 12 children (8–12 years), 20 adolescents (13–17 years) and 70 adults with vitiligo were treated using this procedure. Results The patients obtained satisfactory results (repigmentation of 50% or more) results in children, adolescents and adults were 83.3%, 95.0% and 84.0% respectively. The mean extent of repigmentation in children, adolescents and adults was 80.7%, 78.9% and 76.6% respectively. There was no statistical difference in repigmentation among these three groups. After adjusting for all factors (gender, type of vitiligo, period of stability, location of the lesion or transplanted cell density) individually or totally using multiple regression analysis, age still did not correlate to the extent of repigmentation. Conclusions The satisfactory results obtained in the treatment of vitiligo in children and adolescents by transplantation of cultured autologous pure melanocytes are comparable with the results in adults. Therefore, this procedure can be considered in refractory and stable vitiligo in children and adolescents, especially in patients with large vitiliginous lesions.