Knowledge of the importance of docosahexaenoic acid (DHA), arachidonic acid (AA), and long-chain polyunsaturated fatty acids (LCPUFAs) in neurodevelopment was originally obtained from animal studies. These fatty acids are rapidly accreted in brain during the first postnatal year in animal and human infants, and they are found in high concentrations in breast milk. Reports of enhanced intellectual development in breast-fed children, and reports linking LCPUFA deficiency with neurodevelopmental disorders have stressed the physiological importance of DHA in visual and neural systems. In addition to high concentrations of fatty acids in breast milk, they are also present in fish and algae oil and have recently been added to infant formulas. Esterified poplyunsaturated fatty acids act in cellular membranes, in signal transduction, in neurotransmission, and in the formation of lipid rafts. Nonesterified polyunsaturated fatty acids can modulate gene expression and ion channel activities, thus becoming neuroprotective agents. The conversion of linoleic acid and alpha-linolenic acid into ARA and DHA have led to randomized clinical trials that have studied whether infant formulas supplemented with DHA or both DHA and ARA would enhance visual and cognitive development. This review gives an overview of fatty acids and neurodevelopment, focusing on the findings from these studies.

Shwachman-Diamond Syndrome (SDS) is an inherited condition with multisystemic abnormalities including pancreatic exocrine dysfunction, neutropenia, short stature, and skeletal abnormalities. In this report, we describe the case of a 14-year-old female with a history of neutropenia, pancreatic exocrine insufficiency and pancreatic endocrine sufficiency, pancreatic lipomatosis (10), and the development of myeloid leukemia. Postmortem examination revealed a high probability of SDS. We also describe the clinical findings in the patient's six siblings, suggesting this as a familial form of SDS. Because the gene(s) responsible for this syndrome have not yet been identified, genetic confirmation is not yet possible. This is the first report in the literature of a Mexican family with probable SDS.

OBJECTIVE: To study the incidence of Helicobacter pylori infection in infants from the State of Morelos, Mexico. MATERIAL AND METHODS: A cohort of 110 healthy infants was studied between 1997 and 1999. Serum samples were collected from mothers and their infants at 2, 6, 18, and 24 months of life. All serum samples were tested for antibodies against Helicobacter pylori with the ELISA test. A questionnaire was used to collect socio-economic and clinical data. Associations among selected variables and Helicobacter pylori infection were determined using Fisher's exact test. RESULTS: Two thirds of mothers and six (5.5%) infants tested positive. Two of the six positive infants were born to positive mothers; both of them became negative before age two. The other four infants remained positive. Although not statistically significant, a vaginal birth and more than five people living in the household are possible risk factors for infant H. pylori infection. CONCLUSIONS: Despite the previously reported high prevalence of infection by H. pylori in Mexican children, in this population we found a low incidence of infection in infants up to two years of age. The English version of this paper is available at: http://www.insp.mx/salud/index.html.