Tumor cell seeding in the biopsy tract and its clinical significance in osteosarcomas.

BACKGROUND AND OBJECTIVES: The reasons behind the removal of the biopsy tract in osteosarcomas are not well known, and studies about tumor seeding in the biopsy tract have generated conflicting results. This study is designed to evaluate the presence and possible clinical significance of tumor cell seeding in the biopsy tract of osteosarcomas. METHODS: We prospectively evaluated 55 cases of osteosarcomas for tumor cell seeding and other clinical and pathologic prognostic parameters. RESULTS: Eleven cases (20%) involved microscopic tumor foci in the biopsy tract. The higher local recurrence rates (P = 0.005) and worse recurrence-free survivals ( P = 0.009) were observed in patients with tumor cell foci in the biopsy tract. Mitotic rate, tumor cell pleomorphism, and matrix production in main tumor foci were higher in cases with tumor seeding ( P = 0.047, P = 0.012, and P = 0.005, respectively) CONCLUSIONS: Tumor seeding in the biopsy tract is a fact in osteosarcomas. The higher local recurrence rates are more likely to occur in cases with tumor seeding.

Effects of different recruitment maneuvers on bacterial translocation and ventilator- induced lung injury.

BACKGROUND: Investigated in the present study were the effects of various recruitment maneuvers (RMs) using the same inflation pressure-time product on bacterial translocation from lung to blood, and ventilator-induced lung injury (VILI). METHODS: Tracheotomy was performed on anesthetized rats, and ventilation was initiated using pressure-controlled mode. Subsequently, Pseudomonas aeruginosa was inoculated through the tracheotomy tube and ventilated for 30 minutes before rats were randomly separated into 4 groups. Group 1 underwent sustained inflation (SI), Group 2 underwent low-pressure SI, Group 3 underwent modified sigh, and Group 4 was a control group. Blood cultures were taken at baseline, 15 minutes after randomization (after each RM for the first hour), and finally at 75 minutes after the last RM. The rats were euthanized and the lungs were extirpated. The left lung was taken for measurement of wet:dry weight ratio, and the right lung was used for pathologic evaluation. RESULTS: Positive blood cultures were found to be higher in Group 3 at early study periods. Total pathological scores were also higher in Group 3. CONCLUSION: Higher severity of ventilator-induced lung injury occurred in the modified sigh group, evidenced by bacterial translocation and results of histopathological evaluation.

Effects of body temperature on ventilator-induced lung injury.

PURPOSE: To evaluate the effects of body temperature on ventilator-induced lung injury. MATERIAL AND METHODS: Thirty-four male Sprague-Dawley rats were randomized into 6 groups based on their body temperature (normothermia, 37 +/- 1 degrees C; hypothermia, 31 +/- 1 degrees C; hyperthermia, 41 +/- 1 degrees C). Ventilator-induced lung injury was achieved by ventilating for 1 hour with pressure-controlled ventilation mode set at peak inspiratory pressure (PIP) of 30 cmH2O (high pressure, or HP) and positive end-expiratory pressure (PEEP) of 0 cmH2O. In control subjects, PIP was set at 14 cmH2O (low pressure, or LP) and PEEP set at 0 cmH2O. Systemic chemokine and cytokine (tumor necrosis factor alpha , interleukin 1 beta , interleukin 6, and monocyte chemoattractant protein 1) levels were measured. The lungs were assessed for histological changes. RESULTS: Serum chemokines and cytokines were significantly elevated in the hyperthermia HP group compared with all 3 groups, LP (control), normothermia HP, and hypothermia HP. Oxygenation was better but not statistically significant in hypothermia HP compared with other HP groups. Cumulative mean histology scores were higher in hyperthermia HP and normothermia HP groups compared with control and normothermia HP groups. CONCLUSIONS: Concomitant hyperthermia increased systemic inflammatory response during HP ventilation. Although hypothermia decreased local inflammation in the lung, it did not completely attenuate systemic inflammatory response associated with HP ventilation.