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Biomedical subjects

A Sanches

Publications and source records attributed to A Sanches.

5 recordsLinked to original sources

Standardized uptake value in pediatric patients: an investigation to determine the optimum measurement parameter.

Although the standardized uptake value (SUV) is currently used in fluorine-18 fluorodeoxyglucose positron emission tomography (FDG-PET) imaging, concerns have been raised over its accuracy and clinical relevance. Dependence of the SUV on body weight has been observed in adults and this should be of concern in the pediatric population, since there are significant body changes during childhood. The aim of the present study was to compare SUV measurements based on body weight, body surface area and lean body mass in the pediatric population and to determine a more reliable parameter across all ages. Sixty-eight pediatric FDG-PET studies were evaluated. Age ranged from 2 to 17 years and weight from 11 to 77 kg. Regions of interest were drawn at the liver for physiologic comparison and at FDG-avid malignant lesions. SUV based on body weight (SUV(bw)) varied across different weights, a phenomenon less evident when body surface area (SUV(bsa)) normalization is applied. Lean body mass-based SUV (SUV(lbm)) also showed a positive correlation with weight, which again was less evident when normalized to bsa (SUV(bsa-lbm)). The measured liver SUV(bw) was 1.1+/-0.3, a much lower value than in our adult population (1.9+/-0.3). The liver SUV(bsa) was 7.3+/-1.3. The tumor sites had an SUV(bw) of 4.0+/-2.7 and an SUV(bsa) of 25.9+/-15.4 (65% of the patients had neuroblastoma). The bsa-based SUVs were more constant across the pediatric ages and were less dependent on body weight than the SUV(bw). These results indicate that SUV calculated on the basis of body surface area is a more uniform parameter than SUV based on body weight in pediatric patients and is probably the most appropriate approach for the follow-up of these patients.

Adolescent↗

Activation of the growth plates on three-phase bone scintigraphy: the explanation for the overgrowth of fractured femurs.

Children with an uncomplicated femoral fracture, treated with superimposition of fragments and intentional shortening, usually develop overgrowth of the fractured femur and the ipsilateral tibia which may compensate for the initial shortening and enable the limb in question to reach a length similar to that on the normal side. The overgrowth is evaluated clinically and by scanography. The increased metabolic activity of the growth plates that support this overgrowth has not been documented by any laboratory method. In order to evaluate the metabolic activity of the growth plates, 18 patients (11 males, seven females; mean age 6.1 years) with fractures of the femur were studied at three different time intervals (2-5 months, 6-12 months and 18-24 months). Three-phase bone scintigraphy was performed in all patients. Ten children (five males, five females; mean age 7.5 years) who had had bone imaging for other reasons were used as the control group. Visual analysis of the flow and equilibrium phases was performed for the distal femoral and proximal tibial growth plates. Visual and semi-quantitative analyses of the delayed images were performed for the distal femoral and proximal and distal tibial growth plates. Semi-quantitative analyses yielded the following activity ratios: (a) the distal femoral growth plate of the fractured femur to the contralateral one (FR); (b) the proximal growth plate of the tibia on the side of the fractured femur to the contralateral one (TpR); (c) the distal growth plate of the tibia on the side of the fractured femur to the contralateral one (TdR); and (d) in the control group, the distal growth plates of both femora (FCG) and the proximal (TCGp) and distal (TCGd) growth plates of the tibiae. Visual analysis of the blood flow, equilibrium and delayed images showed increased activity in the distal femoral growth plates during the first and second time intervals, but not during the third. No significant activity changes were found in the proximal and distal tibial growth plates during any of the phases analysed. The mean and standard deviation for FR in the three time intervals were: FRI=1.22+/-0.27, FRII=1.17+/-0.16 and FRIII=1.09+/-0.20. FR values were significantly higher than in the control group (FCG=0.99+/-0.03) (P=0.033). The mean and standard deviation for TpR in the three time intervals were: TpRI=1.08+/-0.18, TpRII=0.94+/-0.09 and TpRIII=0.96+/-0.20. TpR values were not significantly different from those in the control group (TCGp=1.00+/-0.05). However, TpRI was significantly higher than TpRII (P=0.043). The mean and standard deviation for TdR in the three time intervals were: TdRI=1.10+/-0.41, TdRII=1.05+/-0.15 and TdRIII=1.13+/-0.36. TdR values were not significantly higher than in the control group (TCGd=1.00+/-0.04) (P=0.777). These results support the concept that three-phase bone imaging is able to quantify and determine that activation occurs in the distal femoral and proximal tibial growth plates of fractured femora. This phenomenon may explain the overgrowth observed in this injured bone structure.

Bone Development↗

Mortality attributed to myocardial infarction in the male and female population of Salvador, BA, between 1981 and 1996.

OBJECTIVE: To describe according to gender the trend in mortality attributed to myocardial infarction (MI) in the population of Salvador, Bahia between 1981 and 1996. METHODS: This study was on mortality due to MI estimates by period and gender of the city of Salvador, Bahia. Data from 1981 to 1996 were stratified by quadrienia, and the percentage reduction in death rate due to MI relative to the preceding period (PRR) was determined. Comparisons between genders were expressed by the male/female death ratio (DR) based on the gender-related PPR. RESULTS: An overall increase of approximately 8% was observed in the death rate attributed to MI for the period 1985-1988 (89.2/10 5 individuals / year) versus the period 1981-1984 (82.1/10(5)/ year). In the subsequent periods, overall reductions of 10% and 20.3% were observed for the periods 1989-1992 and 1993-1996, respectively. For men, the PPRs were 11.1 in the period 1989-1992 and 22.7% in the period 1993-1996. The PPRs in women were lower: 8.6% and 17.4% between 1989 and 1992, and 1993 and 1996, respectively. Death rate reduction was greater for men than women, then the male/female DR decreased from 1.66 in 1981-1984 to 1.35 in 1993-1996. CONCLUSION: The results indicate a trend towards a reduction in the death rate attributed to myocardial infarction in the city of Salvador from the second half of the 1980s onwards, striking in men.

Adult↗

Comparative efficacy evaluation of moxidectin gel and ivermectin paste against internal parasites of equines in Brazil.

A total of 24 male and female equines of mixed breed, 10-20 months of age and naturally infected with internal parasites was utilized in a controlled test to evaluate the efficacy of a moxidectin 2% gel formulation at the dosage of 0.4 mg moxidectin per kg of live weight and an ivermectin 1.87% commercial paste formulation at the dosage 0.2 mg ivermectin per kg applied orally. Animals were allocated into three groups of eight horses each based on pre-treatment eggs per gram (EPG) counts and treatments were randomized among the groups. One group was kept as untreated controls. One animal in the moxidectin-treated group died before the end of the trial from a cause unrelated to treatment leaving a total of seven animals in this group. Fecal egg counts were performed three times post-treatment and the number of parasites remaining in each animal was determined. Statistical analyses using geometric means were performed at the 1% level of significance. Both moxidectin and ivermectin preparations reduced initial EPG from a mean of 1600 to 0 on Days 5, 7 and at the end of the trial on Day 14. Efficacy percentages of moxidectin and ivermectin against immature and adult nematodes were as follows: Trichostrongylus axei, Parascaris equorum, Strongylus edentatus, S. vulgaris, Triodontophorus spp. and Gyalocephalus capitatus, 100% for both products; Habronema muscae 99.5 and 99.6%, respectively, Strongyloides westeri, 100 and 99.2%, respectively; Oxyuris equi, 99.6 and 100%, respectively; small strongyles, 99.7% for both products. Of the latter, the most numerous were: Cylicocyclus insigne, Cylicostephanus longibursatus and Cyathostomum catinatum. No Gasterophilus nasalis were found in horses from either treated group, while two of eight control horses had infections with thisparasite. Moxidectin showed greater efficacy (84.9%) than ivermectin (67.8%) against Strongylus vulgaris larvae found in the mesenteric artery aneurisms, but the difference was not statistically significant. Total parasite counts for both treated groups were significantly lower (p<0.01) than in the non-treated group. No significant differences were noted between moxidectin and ivermectin. Efficacy against the 30 nematode species found in this study was very evident for both products. As expected, neither moxidectin nor ivermectin was effective in controlling the tapeworm Anoplocephala perfoliata. No adverse reactions were observed during the experimental period.

Animals↗