Congenital hypothyroidism as a risk factor for hearing and parents' knowledge about its impact on hearing.

AIM: To evaluate the hearing of children with congenital hypothyroidism (CH) and to analyze the knowledge that parents' have on the possible auditory impacts of the disease. METHODS: A total of 263 parents/guardians were interviewed about aspects of CH and hearing. Audiological evaluation was performed on 80 participants, divided into two groups: with CH (n= 50) and without CH (n=30). Clinical and laboratory CH data were obtained from medical records, pure tone auditory thresholds and acoustic reflexes were analyzed. The auditory data was compared between groups. Student's t-test and Chi-square were used for statistical analysis at a significance level of 5% (p ≤0.05). RESULTS: The majority (78%), of the parents were unaware that CH when not treated early is a potential risk to hearing. There was no correlation between socioeconomic class and level of information about CH and hearing (p>0,05; p=0.026). There was a statistically significant difference between the auditory tone thresholds of the groups and between the levels of intensity necessary for the triggering of the acoustic reflex. The group with CH presented the worst results (p≤0.05) and absence of acoustic reflex in a normal tympanometric condition. CONCLUSIONS: Children with CH are more likely to develop damage to the auditory system involving retrocochlear structures when compared to healthy children, and that the disease may have been a risk factor for functional deficits without deteriorating hearing sensitivity. The possible impacts of CH on hearing, when not treated early, should be more publicized among the parents/guardians of this population.

Cloning, expression, purification, crystallization and preliminary structure determination of glucose-1-phosphate uridylyltransferase (UgpG) from Sphingomonas elodea ATCC 31461 bound to glucose-1-phosphate.

The cloning, expression, purification, crystallization and preliminary crystallographic analysis of glucose-1-phosphate uridylyltransferase (UgpG) from Sphingomonas elodea ATCC 31461 bound to glucose-1-phosphate are reported. Diffraction data sets were obtained from seven crystal forms in five different space groups, with highest resolutions ranging from 4.20 to 2.65 A. The phase problem was solved for a P2(1) crystal form using multiple isomorphous replacement with anomalous scattering from an osmium derivative and a SeMet derivative. The best native crystal in space group P2(1) has unit-cell parameters a = 105.5, b = 85.7, c = 151.8 A, beta = 105.2 degrees . Model building and refinement are currently under way.