Temporomandibular disorders among Brazilian adolescents: reliability and validity of a screening questionnaire

Temporomandibular disorders (TMD) screeners assume significant item overlap with the screening questionnaire proposed by the American Academy of Orofacial Pain (AAOP).

Objective

To test the reliability and validity of the Portuguese version of AAOP questions for TMD screening among adolescents.

Material and Methods

Diagnoses from Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) Axis I were used as reference standard. Reliability was evaluated by internal consistency (KR-20) and inter-item correlation. Validity was tested by sensitivity, specificity, predictive values, accuracy and receiver operating characteristic (ROC) curves, the relationship between the true-positive rate (sensitivity) and the false-positive rate (specificity). Test-retest reliability of AAOP questions and intra-examiner reproducibility of RDC/TMD Axis I were tested with kappa statistics.

Results

The sample consisted of 1307 Brazilian adolescents (56.8% girls; n=742), with mean age of 12.72 years (12.69 F/12.75 M). According to RDC/TMD, 397 [30.4% (32.7% F/27.3% M)] of adolescents presented TMD, of which 330 [25.2% (27.6% F/22.2% M)] were painful TMD. Because of low consistency, items #8 and #10 of the AAOP questionnaire were excluded. Remaining items (of the long questionnaire version) showed good consistency and validity for three positive responses or more. After logistic regression, items #4, #6, #7 and #9 also showed satisfactory consistency and validity for two or more positive responses (short questionnaire version). Both versions demonstrated excellent specificity (about 90%), but higher sensitivity for detecting painful TMD (78.2%). Better reproducibility was obtained for the short version (k=0.840).

Conclusions

The Portuguese version of AAOP questions showed both good reliability and validity for the screening of TMD among adolescents, especially painful TMD, according to RDC/TMD.     

Inherited thrombophilias and pre-eclampsia in Brazilian women

OBJECTIVE: The aim of the present study was to compare the distribution of G1691A, G20210A and C677T mutations in pre-eclamptic Brazilian women and in matched control women with an uncomplicated normal pregnancy. STUDY DESIGN: these mutations were investigated by PCR-RFLP in 83 normal pregnancies (control group) and in 30 pre-eclamptic pregnant women (severe form). RESULTS: G1691A mutation was detected neither in the control group nor in pre-eclamsia women. G20210A mutation was detected in heterozygosis in 3 (3.61%) control subjects, but not in pre-eclampsia group. C677T mutation was detected in homozygosis in 6 (7.23%) control subjects and 2 (6.67%) pre-eclamptic women and in heterozygosis in 31 (37.3%) control subjects and 12 (40%) pre-eclamptic women. Differences in the mutation frequencies detected in the two groups were not statistically significant. CONCLUSION: No correlation was observed between pre-eclampsia and presence of G1691A, G20210A and C677T mutations in Brazilian women.     

Preeclampsia: the role of tissue factor and tissue factor pathway inhibitor

Preeclampsia (PE) is a multi-system disorder of human pregnancy, whose etiology remains poorly understood. Preeclamptic women are known to have an increased hypercoagulable state that result in excess fibrin deposition in several organs, which compromises their function. Tissue factor (TF) is the main physiological initiator of blood coagulation and its activity is regulated by a specific inhibitor known as Tissue factor pathway inhibitor (TFPI). Based on the important role of TF and TFPI in hemostasis, we hypothesize that their levels may change in the severe PE contributing to exacerbate hypercoagulable state. Some studies have assessed the balance between TF and TFPI in preeclamptic women, but results are inconsistent. Therefore, the aim of this study was to examine these inconsistencies and to assess TF and TFPI plasma levels in three groups of age matched women; pregnant with severe PE (n = 60), normotensive pregnant (n = 50) and normotensive non-pregnant women (n = 50). There was not significantly different among the three groups for TF plasma levels; severe PE women: 338.4 pg/mL (248.1-457.6), normotensive pregnant women: 301.5 pg/mL (216.4-442.9) and normotensive non-pregnant women 393 pg/mL (310.3-522.9). TFPI plasma levels were higher in severe PE comparing to normotensive pregnant women and normotensive non-pregnant women, 115.8 ng/mL (75-149.8); 80.3 ng/mL (59.6-99.7) and 74.5 ng/mL (47.1-98.0), respectively No difference was found between normotensive pregnant women and normotensive non-pregnant women. As for gestational age, a significant difference in TFPI levels was found between severe PE and normotensive pregnant women up to the 33rd week of pregnancy (p = 0.001), and severe PE and non-pregnant women up to the 34th (p = 0.01). In summary, our results indicated that TF plasma levels did not vary in the studied groups, while TFPI plasma levels were significantly increased in severe PE compared to normotensive pregnant and normotensive non-pregnant women. So, our data do not explain the exacerbated hypercoagulability state observed in severe PE. Further studies evaluating genes expression, TF activity and antigen, total and free TFPI and TFPI-2, both in plasma and obstetric tissues, throughout the pregnancy in PE (mild and severe forms) are required.     

Identification of the key amino acids of gliai cell line-derived neurotrophic factor family receptor alpha 1 involved in its biological function

Glial cell line-derived neurotrophic factor （GDNF） plays a critical role in neurodevelopment and survival of midbrain dopaminergic and spinal motor neurons in vitro and in vivo. The biological actions of GDNF are mediated by a two-receptor complex consisting of a glycosylphosphatidylinositol-linked cell surface molecule, the GDNF family receptor alpha 1 （GFR alpha 1）, and receptor protein tyrosine kinase Ret. Although structural analysis of GDNF has been extensively examined, less is known about the structural basis of GFR alpha 1 function. In this study, based on evolutionary trace method and relative solvent accessibility prediction of residues, a set of trace residues that are solvent-accessible was selected for site-directed mutagenesis. A series of GFR alpha 1 mutations was made, and PC12 cell lines stably expressing different GFR alpha 1 mutants were generated. According to the survival and differentiation responses of these stable PC12 cells upon GDNF stimulation and the GDNF- GFR alpha 1-Ret interaction assay, residues 152NN153, Arg259, and 316SNS318 in the GFR alpha 1 central region were found to be critical for GFR alpha 1 binding to GDNF and eliciting downstream signal transduction. The single mutation R259A in the GFR alpha 1 molecule simultaneously lost its binding ability to GDNF and Ret. However N152A/N153A or S316A/N317A/ S318A mutation in the GFR alpha 1 molecule still retained the ability to bind with Ret. These findings suggest that distinct structural elements in GFR alpha 1 may be involved in binding to GDNF and Ret.     

Computer graphics for digitally formatted images

The increasing use of digitally formatted imaging systems requires high-quality interactive gray-scale computer raster graphics systems for the management, display, and analog film recording of digital image and alphanumeric information. These systems are a combination of computer hardware and software and implement a set of graphics protocols. This paper describes a set of interactive graphics protocols that has been developed for clinical use.     

Predictive model for cocaine use in prisons in Rio de Janeiro, Brazil

OBJECTIVE: To identify predictors of and groups vulnerable to cocaine use in prison. METHODS: We selected 376 inmates with history of cocaine use in prison (cases) and 938 inmates with no history of drug use (controls) serving sentences in the Rio de Janeiro State prison system in 1998. The analysis included exposure variables divided into three hierarchical levels: distal, intermediate, and proximal. We performed bivariate analysis using logistic regression and multivariate analysis using hierarchized regression; results are given in odds ratios. RESULTS: Variables associated with cocaine use in prison in the proximal level were use of alcohol and marijuana and duration of imprisonment in years. The effect of social vulnerability variables (distal level) was intermediated by variables in the next levels. Considering only the distal and intermediate levels, use of marijuana prior to imprisonment (OR=4.50; 95% CI: 3.17-6.41) and offence in order to obtain drugs (OR=2.96; 95% CI: 1.79-4.90) showed the strongest association with the outcome. For every additional year spent in prison, the odds of cocaine use increase by 13% (OR=1.13; 95% CI: 1.06-1.21). CONCLUSIONS: Considering the distal and intermediate levels, use of marijuana prior to imprisonment and perpetration of offence in order to obtain drugs were the variables with greatest predictive value. The final model showed alcohol and marijuana use in prison and duration of imprisonment as important predictors of the outcome. The prison environment appears as a factor stimulating drug use.