Non-Invasive Prediction of Histologic Chorioamnionitis in Women with Preterm Premature Rupture of Membranes

PURPOSE: To develop a model based on non-invasive clinical and ultrasonographic parameters for predicting the likelihood of subsequent histologic chorioamnionitis in women with preterm premature rupture of membranes (PPROM) and to determine whether the inclusion of invasive test results improves the predictive value of the model. MATERIALS AND METHODS: This retrospective cohort study included 146 consecutive women presenting with PPROM (20-33 weeks). Transvaginal ultrasonographic assessment of cervical length was performed. Maternal serum C-reactive protein (CRP) levels and white blood cell (WBC) counts were measured after amniocentesis. Amniotic fluid (AF) obtained by amniocentesis was cultured, and interleukin-6 (IL-6) levels and WBC counts were determined. The primary outcome measure was histologic chorioamnionitis. RESULTS: Risk scores based on serum CRP concentrations and gestational age (model 1) were calculated for each patient. The model was shown to have adequate goodness of fit and an area under the receiver operating characteristic curve (AUC) of 0.742. When including AF test results (e.g., AF IL-6 levels) in model 1, serum CRP concentrations were found to be insignificant, and thus, were excluded from model 2, comprising AF IL-6 levels and gestational age. No significant difference in AUC was found between models 1 and 2. CONCLUSION: For women with PPROM, the newly developed model incorporating non-invasive parameters (serum CRP and gestational age) was moderately predictive of histologic chorioamnionitis. The inclusion of invasive test results added no predictive information to the model in this setting.

Proposal of non-invasive experimental model to induce scoliosis in rats / Proposta de modelo experimental não-invasivo para indução de escoliose em ratos

BACKGROUND: In the literature, there are several experimental models that induce scoliosis in rats; however, they make use of drugs or invasive interventions to generate a scoliotic curve. OBJECTIVES: To design and apply a non-invasive immobilization model to induce scoliosis in rats. METHODS: Four-week old male Wistar rats (85±3.3g) were divided into two groups: control (CG) and scoliosis (SG). The animals in the SG were immobilized by two vests (scapular and pelvic) made from polyvinyl chloride (PVC) and externally attached to each other by a retainer that regulated the scoliosis angle for twelve weeks with left convexity. After immobilization, the abdominal, intercostal, paravertebral, and pectoral muscles were collected for chemical and metabolic analyses. Radiographic reports were performed every 30 days over a 16-week period. RESULTS: The model was effective in the induction of scoliosis, even 30 days after immobilization, with a stable angle of 28±5º. The chemical and metabolic analyses showed a decrease (p<0.05) in the glycogenic reserves and in the relationship between DNA and total protein reserves of all the muscles analyzed in the scoliosis group, being lower (p<0.05) in the convex side. The values for the Homeostatic Model Assessment of Insulin Resistance indicated a resistance condition to insulin (p<0.05) in the scoliosis group (0.66±0.03), when compared to the control group (0.81±0.02). CONCLUSIONS: The scoliosis curvature remained stable 30 days after immobilization. The chemical and metabolic analyses suggest changes in muscular homeostasis during the induced scoliosis process.

CONTEXTUALIZAÇÃO: Encontram-se na literatura diversos modelos experimentais de indução de escoliose em ratos, porém evidencia-se o uso de drogas ou intervenções invasivas para a geração da curvatura escoliótica. OBJETIVOS: Projetar e aplicar um modelo de imobilização não-invasiva para a indução de escoliose em ratos. MÉTODOS: Ratos Wistar machos com idade inicial de quatro semanas (85±3,3g) foram divididos nos grupos controle (GC) e escoliose (GE). Os animais do GE foram imobilizados por dois cintos (escapular e pélvico) de policloreto de vinila (PVC), interligados externamente por um limitador que regulava o ângulo da escoliose durante 12 semanas, com convexidade à esquerda. Após a imobilização, os músculos abdominais, intercostais, paravertebrais e peitorais bilateralmente foram coletados para as análises químio-metabólicas. Os registros radiológicos foram realizados a cada 30 dias, num total de 16 semanas. RESULTADOS: O modelo foi eficiente e eficaz na indução da escoliose, mesmo após 30 dias da desmobilização, mantendo um ângulo estável de 28±5 graus. Quanto às análises químio-metabólicas, observou-se diminuição (p<0,05) nas reservas glicogênicas e na relação proteína total/DNA de todos os músculos analisados do GE, sendo menores (p<0,05) no lado da convexidade. Os valores do HOMA-IR indicaram um quadro de resistência à insulina (p<0,05) no GE (0,66±0,03) quando comparado ao GC (0,81±0,02). CONCLUSÕES: A curvatura escoliótica manteve-se estável após 30 dias da desmobilização, e as alterações químio-metabólicas sugeriram a ocorrência de modificações na homeostasia muscular durante o processo indutor da escoliose.