Isolation and characterization of starch obtained from Brosimum alicastrum Swarts seeds.

In this paper, the Ramon starch was isolated and its chemical composition and physical and microscopic characteristics were determined. Corn starch was used as reference. In general, the proximal composition was similar between starches studied. Ramon starch granules were oval-spherical and rounded with sizes between 6.5 and 15 µm. Starch purity was high (92.57%) with amylose content of 25.36%. The gelatinization temperature was 83.05°C and transition enthalpy was 21.423 J/g. At 90°C, solubility was 20.42%, swelling power 17.64 g water/gstarch and water absorption capacity was 13 gwater/gstarch. The pH, clarity and color (Hue angle) of Ramon starch were higher to those reported for corn starch. The results achieved suggest that Ramon starch has potential for application in food systems requiring high processing temperatures and it is also a promising option for use in the manufacture of biodegradable materials.

Incidence trends of acute leukemia among the children of Mexico City: 1982-1991.

The objective of this study was to identify the tendency of acute leukemia among children in Mexico City from 1982 to 1991. A hospital survey was performed. Medical records of children under 15 years of age with a diagnosis of acute leukemia were reviewed. The cases were chosen from hospitals which provide medical attention to children with cancer in Mexico City. The annual incidence rate (AIR) was calculated in general, by sex, age groups (under 1 year of age, from 1 to 4 years, 5 to 9 years and 10 to 14 years) and standardized with the world population. The trend was evaluated with Spearman's correlation method. Acute lymphoblastic leukemia showed a significantly increasing trend during the study period. The AIR was 7.75 (per million) in 1982 and 22.19 (per million) in 1991. For age groups a tendency to increase was observed in females of age group 1 to 4 years and in males of age group 10 to 14 years. Acute non-lymphoblastic leukemia did not display a specific trend. In conclusion, acute lymphoblastic leukemia shows a tendency to increase in the children of Mexico City.

[Risk factors associated with the development of leukemia in children]. / Factores de riesgo asociados al desarrollo de leucemia en niños.

INTRODUCTION: Leukemia is the most frequent neoplasia in children; in our country it is the main cause of medical attention in children with cancer. The are different risk factors associated with the development of this kind of cancer. OBJECTIVE: To identify which of the already known factors described in the literature associated with the development of leukemia are most frequent in the pediatric population of Mexico City. MATERIAL AND METHODS: A protective case-control study was carried out using prevalent and incident cases. In two third level hospitals of Mexico City, a total of 81 children who had been diagnosed as suffering from different kind of leukemia, confirmed by biopsy of bone marrow, were select and studied. The control were 154 children from two different sources: 77 of them came from the same hospital where the cases received medical care, the selection criteria was not to have any kind of neoplasia; and 77 came from the same community where those diagnosed children cases lived, the selection criteria for this group was that they were healthy children. Both cases and community controls were visited at home and interview to complete precoded questionnaire with the different variables of the study. The information from the hospital controls was obtained during the time they stayed in the hospital. Odds ratio (OR's) for the different associations were calculated, as well as its confidence intervals at 95% (IC) accord to Cornfield and unconditioned logistic regression was carried out to control confounding variables. RESULTS: OR greater than 1 was found in those with familiar cancer background 1.93 (1.2-3.63); the mother being exposed to X-ray during pregnancy 1.89 (0.84-4.22); previous abortions before the child with leukemia was born 2.44 (1-06-5.68); being born from full term birth 2.42 (0.47-16.65); being born with weight greater that 3500 g 2.21 (1.04-4.33); being exposed to fertilizers 4.73 (1.04-24.14) and insecticides 1.93 (1.05-3.56). OR smaller than 1 was found in those who have been in a hospital because of an infectious disease during the first year of life 0.57 (0.17-1.74); to have suffered from chicken pox 0.59 (0.32-1.08). No association to parent's age or job was found. Multivariated analysis shows that the exposure to insecticide is the most important risk factor associated with the development of leukemia in children. CONCLUSIONS: We obtained positive associations to different risk factors described in the literature, having found that exposure to fertilizers is the most important risk factor and finding no association with the parent's occupation. This leads to the need of carrying out further studies to investigate, in more detail, the occupation of the father to confirm whether or not this is a risk factor.