Clinical Profile of Autism Spectrum Disorder in a Pediatric Population from Northern Mexico.

Autism spectrum disorder (ASD) is a neurodevelopmental condition classified based on needs of support, in order to address impairments in the areas of social communication and restricted and repetitive behavior. The aim of this work is to describe the main clinical features of the ASD severity levels in a group of Mexican pediatric patients. The results show firstly that this condition was more frequent in males than females. Secondly, an inverse relationship was found between the intellectual coefficient and the level of severity of the disorder. Thirdly, deficits in social reciprocity and communication were more evident in Level 3, than in Levels 1 and 2, while the difference was less evident in restricted and repetitive patterns of behavior.

Neurodegeneration, demyelination, and astrogliosis in rat spinal cord by chronic lead treatment.

Early exposure to lead (Pb) has been associated with an elevated risk of developing neurodegenerative diseases. There is evidence that neuronal damage in chronic Pb exposure can be caused by the convergence of glial damage. Apoptosis may be a possible mechanism of Pb-induced cell death in the central nervous system. We tested cellular damage and apoptosis in the spinal cord of Wistar rats treated with Pb. Twelve rats were divided into two groups (n = 6): the control group was treated with only drinking water and the other group received 500 ppm of Pb acetate. After 3 months of Pb treatment, all animals were euthanized and spinal cords were extracted. Morphology was evaluated by Nissl and Kluver-Barrera stainings. Apoptosis was detected by terminal deoxynucleotidyl transferase dUTP nick end labeling assay. Specific antibodies were used to evaluate Pb damage in oligodendrocytes, astrocytes, and microglia. A large number of apoptotic bodies was observed in the white matter of the Pb-treated group. The Pb-treated group also showed a reduced number of neurons and oligodendrocytes but had an increased number of astrocytes compared with the nontreated group. Our results demonstrate that chronic Pb treatment induces neurodegeneration, demyelination, and astrogliosis in the rat spinal cord.

Ovulatory activity of female goats adapted to the subtropics is responsive to photoperiod.

The objective of this study was to determine whether reproductive seasonality of local well-fed female goats from subtropical Mexico (26 degrees N) can be controlled by photoperiod. The control group (n=12) remained in an open pen under natural photoperiod variations. The two experimental groups (n=8 each) were placed in light-proof rooms and exposed for 2 yr to alternations of 3 months of long days and 3 months of short days. One group was first exposed to long days, Group 1, and the other one to short days, Group 2. Blood samples were obtained twice a week to determine ovulation status by progesterone plasma concentrations. Goats from the control group displayed a seasonality of ovulations. The mean (+/-SEM) dates of the onset and end of the ovulations were September 10+/-5 d and February 16+/-4 d, respectively. In contrast, in both experimental groups, ovulations were modified (P<0.05) by the photoperiodic treatments such that ovulations started and ended during short and long days, respectively. In Groups 1 and 2, ovulations started 67+/-2 and 66+/-2 d (P>0.05), respectively, after the transfer from long to short days. In contrast, the timing of the cessation of ovulations after the transfer from short to long days differed (P<0.05) between groups (19+/-3 and 31+/-3 d for Groups 1 and 2, respectively). Local female goats from subtropical Mexico are, therefore, sensitive to photoperiodic changes that they are exposed to at this latitude and this environmental cue may control the timing of the breeding season in natural conditions.