James, S. J., Cutler, P., Melnyk, S., Jernigan, S., Janak, L., Gaylor, D. W., & Neubrander, J. A. (2004). Metabolic biomarkers of increased oxidative stress and impaired methylation capacity in children with autism. The American journal of clinical nutrition, 80(6), 1611-1617.
Article Summary
Introduction
Autism covers complex neurodevelopmental disorder usually evident in the early stages of childhood and is believed to be influenced by genetic and environmental factors. Abnormal metabolism regarding methionine and homocysteine are linked with another neurologic disease although the evaluation of this fact in persons with autism is underway.
Hypothesis
The purpose of the study aims at evaluating plasma concentrations of metabolites present in the methionine transmethylation and transsulfuration pathways amongst children diagnosed with autism.
Design and Procedure
Levels of methionine, S-adenosylmethionine (SAM), adenosine, homocysteine, cystathionine, cysteine, and oxidized and reduced glutathione were measured in 20 children with autism and 33 control children. Conversely, abnormal metabolic profile entailed a targeted nutritional intervention trial encircling folinic acid, betaine, and methylcobalamin was introduced in a subsection of kids with autism.
Results
Children with autism experienced lower baseline plasma concentrations of methionine, SAM, homocysteine, cystathionine, cysteine, and grand glutathione. Moreover, higher levels observed on SAH, adenosine, and oxidized glutathione. Notably, the metabolic profile showed consistency with impaired capacity for methylation, lower ratio of SAM to SAH but increased oxidative stress in children with autism. The intervention trial normalized the metabolic imbalance in the autistic children.
Critique
Hypothesis
The study conclusively indicated the area of research, which entailed the assessment of plasma concentration relating to the children with autism.
Design and Procedure
The study put forth all the significant levels and the right process to realize the hypothesis. Further, the nutritional intervention trial was included in the subdivision of the autistic children, which facilitated the goal realization.
Results
Every content of the plasma concentration showed positive results highlighting proper processes such as lower baseline plasma concentrations of methionine, SAM, homocysteine, cystathionine, cysteine, and grand glutathione.
Discussion (recommendation and conclusion)
The research purposefully concentrated on the appraising plasma concentrations of metabolites in the methionine transmethylation and transsulfuration pathways in children with autism. Therefore, increased vulnerability to oxidative stress and decreased capacity for methylation should be encouraged as it contributes to the development and clinical manifestation of autism (James et al., 2004).
Secondary Internet Sources
http://www.nejm.org/doi/full/10.1056/NEJMoa021134#t=article
Article Summary
The study centers on the children born in Denmark between 1991 and 1998 after disapproving Measles-Mumps-Rubella (MMR) vaccine use in the country in 1987. The research compares a cohort of unvaccinated kids a population of approximately half a million children who received the vaccine and experienced insignificant relative risk of autism spectrum disorders in the vaccinated population.
Article Critique
The data is inconsistent, which raises a question about the employed methodology. For instance, table one reports 269 vaccinated children with ASD (Autism Spectrum Disorder) and 47 unvaccinated kids with ASD. Table two indicates that 263 vaccinated children with ASD and 53 unvaccinated children with ASD. Finally, the authors admit that the study does not rule out that subpopulation could be vulnerable to the MMR vaccine, making it less efficient.
Secondary Internet Sources
http://www.sciencedirect.com/science/article/pii/S0140673699012398
Article Summary
Research provides a comparison between autism rates before and after administration of MMR vaccine in the UK in 1988. Data indicated a sharp increase in autism diagnosis’s in early 1990s but does not correlate with MMR vaccine uptake, which leveled immediately after introduction. Mostly, the evidence did not show a temporal association between MMR vaccine timing and autism onset but highlighted information concerning the age of first parental concern clustering between zero and six months of diagnosis of MMR. Lastly, authors discredit the finding by saying that parents chose an age of first concern including 18 months since it was a whole figure.
Critique
The assertion that parents embraced an age of concern over 18 months since it was a round number is unproven. Hence, not a valid explanation for the cluster of data that shows otherwise.
Secondary Scientific sources
DeWilde, S., Carey, I. M., Richards, N., Hilton, S. R., & Cook, D. G. (2001). Do children who become autistic consult more often after MMR vaccination?. Br J Gen Pract, 51(464), 226-227
Article Summary
According to DeWilde, Carey, Richards, Hilton, & Cook (2001), the researcher stated that since MMR vaccine was responsible for autism, then children with symptoms would have a significant increase in general practitioner visits post-immunization. Data was used to compare PCP visits of autistic children against visits by non-autistic kids within six months of receiving MMR vaccine. No significant increase in doctor visits were found.
Critique
The source vividly touches on the post-immunization MMR vaccine visits amongst children. However, the article based on the presumption that in case the MMR causes autism, then the number of general practitioner visits would hike for autistic children after the administration of first MMR vaccine. Ideally, it does not include the number of specialist visits. As such, the practitioners would not have autistic children frequently but would make referrals to specialists to examine the signs of adverse reaction. Additionally, the information does not show the number of kids getting treatment outside the six months’ window period.
Mäkelä, A., Nuorti, J. P., & Peltola, H. (2002). Neurologic disorders after measles-mumps-rubella vaccination. Pediatrics, 110(5), 957-963.
Summary of the Article
The study focused on determining whether there was a relationship between MMR vaccination and hospitalization of kids. The research settled on encephalitis of three months of MMR vaccine, aseptic meningitis within three months of treatment, and autism, which included the period of analysis. The author asserted that no temporal relationship exists between MMR vaccine and any of the three diagnoses. There was no grouping of hospitalizations for autism at any intervals regarding immunization (Mäkelä, Nuorti, & Peltola, 2002).
Article Critique
The study indicates that peak rates of autism diagnoses resulted after MMR vaccine administration, involving 0-6 month window period. The data revolves around autism hospitalization, which may lead to under-ascertainment of autism cases since many diagnosis instances are done in an outpatient setting. Besides, the diagnoses do not reflect the actual onset of symptoms encompassing regression.
References
- DeWilde, S., Carey, I. M., Richards, N., Hilton, S. R., & Cook, D. G. (2001). Do children who become autistic consult more often after MMR vaccination?. Br J Gen Pract, 51(464), 226-227
- James, S. J., Cutler, P., Melnyk, S., Jernigan, S., Janak, L., Gaylor, D. W., & Neubrander, J. A. (2004). Metabolic biomarkers of increased oxidative stress and impaired methylation capacity in children with autism. The American journal of clinical nutrition, 80(6), 1611-1617.
- Mäkelä, A., Nuorti, J. P., & Peltola, H. (2002). Neurologic disorders after measles-mumps-rubella vaccination. Pediatrics, 110(5), 957-963.