Pleural fluid penetration of moxifloxacin and doripenem: An experimental model of empyema.

OBJECTIVE: This study aimed to evaluate the penetration of moxifloxacin and doripenem into the pleural fluid (PF) using a rabbit model of empyema. METHODS: An empyema was induced using the intrapleural injection of turpentine (1 mL), followed 24 h later by instillation of 5 mL Klebsiella Pneumoniae (ATCC 33495), Fusobacterium nucleatum (ATCC 25586) and Streptokok Pneumoniae (ATCC 6305) into the pleural space. After an empyema was corroborated, Moxifloxacin (25 mg/kg-1) and Doripenem (20 mg/kg-1) were administered intraperitoneally. To determine the levels of antibiotics measured by High-Performance Liquid Chromatography in pleural and blood samples were obtained serially at 8, 24, 48 and 72nd hour. RESULTS: The penetration of both antibiotics into the PF was very good. The penetration rate of doripenem (area under the curve (AUC) for PF/blood (AUCPF/AUCblood) ratio=1.68) was better than moxifloxacin (ratio=0.78). Equalization time between the PF and blood concentration of doripenem was more quickly than moxifloxacin. Peak PF concentration of moxifloxacin was 0,81 µg/mL-1 and occurred 8 h after infusion and then gradually decreased; at the beginning of the blood and pleural fluid concentrations of doripenem were equal. While the pleura concentration was increasing, blood concentration was almost the same. Doripenem reached a peak concentration (0.54 µg/ml) 24 h post-administration. CONCLUSION: Differences were found in the penetration of the two antibiotics. Doripenem had convenient penetration PF compared to moxifloxacin. Due to the differences between human and rabbit pleural thickness, doripenem's pleural penetration should be examined in infection models in animals with equal pleura thickness and clinical trials.

Effects of topical mitomycin-C on the tracheal epithelia of rabbits following tracheostomy

Background/aim: We aimed to investigate the topical application of mitomycin-C (MMC) after the conventional tracheostomy in a rabbit model. Materials and methods: Twenty-four male New Zealand White rabbits were randomly divided among 3 equal groups (n: 8). Trache- ostomies were performed on 16 subjects. Group 1 which served as a control for all tracheal measurements. After tracheostomy, we applied sterile saline (group 2) or MMC at 0.8 mg/mL (group 3) around the tracheotomy site for 5 min. At the 3rd week after surgery, all tracheas were subjected to morphometric and histopathological examinations, including tracheal lumen diameter (LD), number of capillary vessels (CV), subepithelial tissue thickness (SETT), fibroblasts, and inflammatory cells (IC). Results: There was a statistically significant difference between the two tracheostomy groups themselves and the control group for LD (p = 0.035), CV (p = 0.006), SETT, fibroblasts, and IC (p < 0.001). Histopathological analysis showed the decreased LD, CV, SETT, IC, and fibroblasts compared to MMC with tracheostomy groups. MMC was more effective than saline for LD, CV, SETT, IC, and fibroblasts. Conclusion: Wound healing modulation may prevent scar formation. Fibrosis decreased following tracheostomy in the group treated with MMC. Fibroblasts appear to be key cells mediating these effects.

How successful is "pleural sound sign" in the identification of pneumothorax?

OBJECTIVE: In the present study, in thorax ultrasonography (USG) Doppler images obtained from cases with occult pneumothorax, we investigated the status of pulsatile pleural sounds over the pleural line and called these as the pleural sound sign (PSS). The purpose of the present study was to identify the efficacy of the proposed PSS in diagnosing pneumothorax and to compare it with the other USG findings including the sliding lung sign (SLS) and seashore sign (SSS). METHODS: The present study included 66 consecutive patients who were referred to the emergency unit with a blunt trauma from October 2009 to January 2010 at a tertiary university hospital. RESULTS: Of the 66 patients, 34 were in the patient group, and 32 were in the control group. Males accounted for 66.7% (n=44) of the study population. In predicting pneumothorax, the areas under receiver operating characteristic (ROC) curves of PSSmax and PSSdifference were 0.989 and 0.990, respectively. While the sensitivity of the SLS was 88% and the sensitivity of the SSS was 56%, the specificities of the SLS and SSS were 100%. Based on our findings, accuracy ranking was as follows: PSSmax = PSSdifference > SLS > SSS. CONCLUSION: New applications of thorax USG are rapidly growing. Our findings have to be confirmed in a large patient series. PSS is not a novel method, but it enhanced the importance of USG in the diagnosis of pneumothorax. We can stipulate that it can replace thorax computed tomography imaging particularly for the diagnosis of occult pneumothoraxes.

Ectopic Cushing's syndrome due to adrenocorticotropic hormone secreting atypical thymic carcinoid tumor.

Cushing's syndromes (CS) due to thymic carcinoids are rarely seen. In this text, a case with CS due to ectopic adrenocorticotropic hormone (ACTH) secreting atypical thymic carcinoid tumor is presented. A 50-year-old Turkish male patient was admitted to our emergency department with typical CS features. Basal hormone profile, low- and high-dose dexamethasone suppression tests, and inferior petrosal sinus sampling results were consistent with ectopic ACTH secretion. Thorax computerized tomography showed an upper mediastinal mass, and trans-thoracic biopsy showed atypical thymic carcinoid with positive ACTH staining. Since the vascular invasion was detected, tumor was accepted inoperable; somatostatine receptor analogs, chemotherapy, and radiotherapy were planned. Ectopic CS can be derived from atypical thymic carcinoid. In this case, ACTH staining was used to confirm ACTH secretion from thymic tissue, and positive staining was detected. ACTH staining routinely was not performed for extra hypophyseal tissue tumors. In suspicious and difficult cases, ACTH staining can be helpful to confirm the presence of ACTH in tumor tissues.