Arthritis induces early bone high turnover, structural degradation and mechanical weakness.

BACKGROUND: We have previously found in the chronic SKG mouse model of arthritis that long standing (5 and 8 months) inflammation directly leads to high collagen bone turnover, disorganization of the collagen network, disturbed bone microstructure and degradation of bone biomechanical properties. The main goal of the present work was to study the effects of the first days of the inflammatory process on the microarchitecture and mechanical properties of bone. METHODS: Twenty eight Wistar adjuvant-induced arthritis (AIA) rats were monitored during 22 days after disease induction for the inflammatory score, ankle perimeter and body weight. Healthy non-arthritic rats were used as controls for compar-ison. After 22 days of disease progression rats were sacrificed and bone samples were collected for histomorphometrical, energy dispersive X-ray spectroscopical analysis and 3-point bending. Blood samples were also collected for bone turnover markers. RESULTS: AIA rats had an increased bone turnover (as inferred from increased P1NP and CTX1, p = 0.0010 and p = 0.0002, respectively) and this was paralleled by a decreased mineral content (calcium p = 0.0046 and phos-phorus p = 0.0046). Histomorphometry showed a lower trabecular thickness (p = 0.0002) and bone volume (p = 0.0003) and higher trabecular sepa-ration (p = 0.0009) in the arthritic group as compared with controls. In addition, bone mechanical tests showed evidence of fragility as depicted by diminished values of yield stress and ultimate fracture point (p = 0.0061 and p = 0.0279, re-spectively) in the arthritic group. CONCLUSIONS: We have shown in an AIA rat model that arthritis induc-es early bone high turnover, structural degradation, mineral loss and mechanical weak-ness.

Noise rich in low frequency components, a new comorbidity for periodontal disease? An experimental study.

INTRODUCTION: Exposure to noise rich in low frequency components induces abnormal proliferation of extracellular matrix and collagens. The previous studies have shown alterations in the periodontium of both humans and animals. Our objective was the evaluation of collagens I, IV and V of the periodontium of Wistar rats exposed to noise rich in low frequency components. MATERIALS AND METHODS: 5 groups (each with 10 animals) were exposed to continuous low frequency noise (LFN). The LFN, from previously recorded white noise, frequency filtered and amplified, was applied in growing periods of 1, 3, 5, 9 and 13 weeks, in order to characterize the alterations with exposure time. A control group of ten animals was kept in silence. These animals were used in groups of 2 as aged-matched controls. After exposure, sections were obtained including teeth, alveolar bone and periodontium and observed after immunollabeling for collagens I, IV and V. RESULTS: A significant increase in collagen I was observed in exposed groups (P < 0.001) (Kruskal-Wallis test). Post-hoc comparisons (Mann-Whitney test with Bonferroni correction) showed an increase in collagen I in animals exposed for 3 weeks or more (P < 0.001). The same test was applied to collagen V where significant differences were found when comparing control and exposed groups (P ≤ 0.004). The t-test for independent samples was applied to collagen type IV where no significant differences were found (P = 0.410), when comparing to the control group. DISCUSSION: As in other organs, we can observe fibrosis and the newly formed collagen is likely to be "nonfunctional", which could have clinical impact. CONCLUSION: Noise may constitute a new comorbidity for periodontal disease.

Risk factors for surgical site infection in cervico-facial oncological surgery.

INTRODUCTION: Infection after head and neck oncological surgery is relatively frequent, and is associated with significant morbidity and mortality. AIM: The primary objective of this prospective study was to determine risk factors for Surgical Site Infection (SSI) in major head and neck cancer surgery. PATIENTS AND METHODS: A population of 137 head and neck cancer patients, of the Portuguese Institute of Oncology Francisco Gentil (Lisbon, Portugal), was prospectively studied in order to ascertain the correlation between 31 known risk factors and the presence of SSI. RESULTS: The rate of SSI was 10.9%, with all of the infections being of the deep incisional type. A discriminant analysis and multiple logistic regression methods identified pre-surgical tracheostomy (p < 0.001), previous surgery (p = 0.001) and length of pre-operative hospital stay (p < 0.001) as the most significant risk factors for surgical site infections. CONCLUSION: In order to minimize the risk of post-operative SSI in the context of head and neck cancer patients, particular attention should be paid to patients submitted to tracheostomy before surgery, to those submitted to previous oncological surgery, and to patients who are forced to remain in the hospital for prolonged periods of time before surgery.

Predictors of positive axillary lymph nodes in breast cancer patients with metastatic sentinel lymph node.

INTRODUCTION: Breast cancer with metastatic sentinel lymph nodes (SLN) may have clinico-pathologic factors associated with the presence of positive non-sentinel axillary nodes (NSLN). The aim of the present study was to determine factors that predict involvement of NSLN in breast cancer patients with positive SLN. MATERIAL AND METHODS: A prospective database search identified 80 patients who underwent SLN biopsy for invasive breast cancer between January 1999 and August 2002. Clinico-pathologic data was analyzed to determine factors that predicted additional positive axillary nodes. RESULTS: A total of 23 patients had positive SLN and underwent conventional axillary lymph node dissection. Statistical analysis revealed that lympho-vascular invasion (p~0.00000), SLN metastasis >2 mm (p=0.002), and the presence of extra-nodal involvement (p=0.002), were positive predictors of the metastatic involvement of NSLN. CONCLUSIONS: The likelihood of positive NSLN correlates with pathologic parameters such as the presence of lympho-vascular invasion, size of the SLN metastasis, and extra-nodal involvement. These data may be helpful with the regard to the decision to undertake axillary dissection in breast cancer patients with metastatic sentinel lymph nodes.

Predictors of positive axillary lymph nodes in breast cancer patients with metastatic sentinel lymph node

Introducción. El cáncer de mama con ganglio centinela (GC) metastásico podría estar asociado a factores clínico-patológicos relacionados con la presencia de ganglios linfáticos axilares no-centinela (GLANC) positivos. El objetivo de este trabajo es determinar los factores que predicen la implicación de los GLANC en los pacientes con cancer de mama con GC positivos. Material y métodos. Se procede a análisis retrospectivos de una base de datos que incluyen pacientes con carcinoma de mama invasivo sometidos a biopsia del ganglio centinela, correspondiente a enero de 1999 a agosto de 2002 (n=80). Los factores clínico-patológicos fueron analizados con el objetivo de determinar los factores predictivos de los ganglios axilares positivos adicionales. Resultados. En el análisis global de la población, se verificó que existían 23 pacientes con GC positivos, que fueron sometidos a disección ganglionar axilar convencional. El análisis estadístico reveló que la invasión linfovascular (p~0,00000), la dimensión de la metástasis mayor de 2 mm (p=0,002) y la presencia de extensión extranodal (p=0,002), correspondieron a factores predictivos positivos de desarrollo metastásico de los GLANC. Conclusiones. La probabilidad de la existencia de GLANC positivos se correlaciona con parámetros patológicos como la presencia de invasión linfovascular, el tamaño de metástasis de los GC, y la extensión extranodal. Estos datos podrán ser útiles en lo que concierne a la decisión terapéutica de efectuar la disección ganglionar axilar convencional en los pacientes con cáncer de mama con GC metastásico

Introduction. Breast cancer with metastatic sentinel lymph nodes (SLN) may have clinico-pathologic factors associated with the presence of positive non-sentinel axillary nodes (NSLN). The aim of the present study was to determine factors that predict involvement of NSLN in breast cancer patients with positive SLN. Material and methods. A prospective database search identified 80 patients who underwent SLN biopsy for invasive breast cancer between January 1999 and August 2002. Clinico-pathologic data was analyzed to determine factors that predicted additional positive axillary nodes. Results. A total of 23 patients had positive SLN and underwent conventional axillary lymph node dissection. Statistical analysis revealed that lympho-vascular invasion (p~0.00000), SLN metastasis >2 mm (p=0.002), and the presence of extra-nodal involvement (p=0.002), were positive predictors of the metastatic involvement of NSLN. Conclusions. The likelihood of positive NSLN correlates with pathologic parameters such as the presence of lympho-vascular invasion, size of the SLN metastasis, and extra-nodal involvement. These data may be helpful with the regard to the decision to undertake axillary dissection in breast cancer patients with metastatic sentinel lymph nodes