Lysosomes as a possible target of enniatin B-induced toxicity in Caco-2 cells.

Enniatins are cyclic hexadepsipeptidic mycotoxins with ionophoric, antibiotic, and insecticidal activity. Enniatin B (EnnB), the most important analogue, is produced by many Fusarium species and is a common contaminant in grain-based foods. The compound's cytotoxic potential has been shown in different experiments; however, the mode of action has not been detailed so far. In the present study, several mutually confirmative experiments have been performed indicating that EnnB-initiated cytotoxicity could be connected with lysosomal membrane permeabilization (LMP). Lysosomal functionality, as assessed by the Neutral Red assay, was already affected after 3 h of toxin exposure. After 24 h, cell proliferation was decreased, and there was indication for a cell cycle arrest in the G(2)/M phase leading to the initiation of apoptosis or necrosis. Intracellular ROS-production was observed. However, antioxidants did not alter the observed EnnB-induced loss of lysosomal functionality leading to the conclusion that ROS was not an initial factor but one produced later in the event cascade. The collected data suggested that lysosomal destabilization is an upstream event in EnnB-initiated cytotoxicity followed by a certain extent of translocation of cathepsins into the cytosol, which was observed using immunological and proteomic methods. It appeared that cell death induced by EnnB was delayed and occurred not as a massive lysosomal breakdown but was probably progressing and leading to partial and selective LMP, starting a nonapoptotic cell death pathway with morphological features that had been previously considered as necrotic. The molecular mechanism of EnnB-triggered lysosomal destabilization, and the cellular processes leading to mitochondrial permeabilization and cell death are still unknown. They may, however, be connected to the compound's ionophoric properties.

Autologous breast reconstruction with use of transverse rectus abdominis musculocutaneous flap: Mayo clinic experience with 147 cases.

OBJECTIVE: To assess the results of transverse rectus abdominis musculocutaneous (TRAM) flap reconstructions of the breast. DESIGN: We retrospectively reviewed 147 consecutive cases of TRAM reconstructions of the breast performed at the Mayo Clinic between 1981 and 1992. MATERIAL AND METHODS: The median patient age was 47 years, and the median duration of follow-up was 29 months. In 25 patients, both rectus pedicles were used, 15 of those for bilateral reconstruction. The other 122 patients had unipedicled unilateral reconstruction. Only 9% of the breast reconstructions were immediate. Analysis of risk factors in the patient population revealed smoking in 16%, preoperative irradiation of the chest wall in 20%, preoperative chemotherapy in 27%, and both radiotherapy and chemotherapy in 12%. RESULTS: The mean overall operative time was 4 hours and 43 minutes (4 hours and 20 minutes for unipedicled flaps and 5 hours and 46 minutes for bipedicled reconstructions). No blood transfusion was needed in 47% of patients; of those who received transfusions, 78% required 2 units or less. In 58 of the 147 patients (39%), an operation was performed on the contralateral breast. Follow-up operations were necessary in 71% of patients. The overall frequency of complications was as follows: hernia that necessitated surgical repair, 7.5%; full TRAM ischemic loss, 3.7%; partial TRAM loss, 9.9%; and fat necrosis, 11.7%. No pattern of increased complications was noted in subgroups of patients who smoked or who had received preoperative irradiation, chemotherapy, or both. In comparison with our early cases, the last 50 TRAM procedures were generally associated with fewer complications. The rates of occurrence of complications in our series of patients were similar to those reported in the literature. CONCLUSION: The TRAM flap provides satisfactory results for reconstruction of the breast.

Massive abdominal-wall hernia reconstruction with expanded external/internal oblique and transversalis musculofascia.

We describe a technique for expansion and primary closure of massive and large recalcitrant abdominal-wall hernias in the middle and lower abdomen utilizing expanders placed in the lateral abdominal wall between the external oblique and the deeper complex of the internal oblique and transversalis fasciae. Since this technique describes expansion of the lateral abdominal wall, insertion incisions are made in the lateral abdominal wall away from the primary zone of injury surrounding the abdominal hernia and without interrupting the blood supply or innervation to the abdominal-wall muscle, fascia, or skin. This technique, described in four patients with massive abdominal-wall hernias, has been used successfully for primary closure with vascularized autogenous abdominal-wall fascia, obviating the need for interposition of prosthetic material or extraabdominal flaps.

Closed blunt chest trauma causing mediastinal abscess.

Posttraumatic bacterial mediastinal abscess resulting from closed blunt trauma without penetrating injury or tracheal or esophageal rupture is, to our knowledge, previously unreported. We report a case of a patient injured in a motor vehicle collision that resulted in closed blunt chest trauma and mediastinal abscess 14 days after injury. Initial chest roentgenogram revealed a widened mediastinum. Computed tomographic scan of the chest revealed comminuted fractures of the upper sternum, manubrium, and the 3rd and 4th left anteriolateral ribs and a retrosternal hematoma. Transesophageal echocardiography was negative. The patient was dismissed 2 days after injury and returned to the hospital 14 days after injury with a fluctuant, pulsatile, upper midline chest wall and anteriolateral chest wall staphylococcal abscesses. The abscesses were drained and the sternomanubrial wound debrided in stages. The mediastinal defect was reconstructed with a pectoralis major muscle flap. This most likely represents bacterial seeding of the mediastinal hematoma from a distant source.

Safety and efficacy of combined upper blepharoplasties and open coronal browlift: a consecutive series of 600 patients.

Surgical rejuvenation of the upper face involves the correction of excess and lax forehead, eyelid, and periorbital skin. Improving the appearance by correcting the effects of aging involves a combination of blepharoplasty and open coronal foreheadplasty. Many surgeons and several reports question the safety of both procedures being performed concomitantly. The difficulty arises in precisely balancing the skin excision from the frontal forehead and upper eyelid areas. Over-resection of skin may result in incomplete closure of the eyelid and dry-eye syndrome, while an inadequate resection may produce a poor aesthetic result. There is no large series that documents the safety and effectiveness of these two procedures being performed concomitantly. Furthermore, with the recent and rapid development of complex multiplanar endoscopic facial rejuvenation techniques, the basic open foreheadplasty has become increasingly overlooked as a legitimate, efficacious technique for rejuvenation of the upper face. The technique utilized in this series is presented in detail. The consistently excellent results obtained satisfy the aesthetic goals of patients as well as the goals of surgeons, and suggest a renewed interest in the technique based upon its simplicity and easily reproducible results.

Lag-screw technique in free osseous mandibular reconstruction.

The surgical registry was reviewed for mandibular reconstruction from 1988 to 1992. During this time, 51 patients underwent mandibular reconstruction. Of this group, 17 patients had their microvascular bone grafts secured with lag-screw fixation. An AO technique, utilizing 2.7-mm cortical screws, was used to provide rigid fixation. Mandibular defects ranged from 6 to 20 cm. AO vascularized bone grafts were studied with bone scans and remained viable. Follow-up revealed no flap losses or oral cutaneous fistulae. Lag-screw fixation, in conjunction with mandibular reconstruction, results in rigid fixation, obviates the need for mandibulamaxillary fixation, has the advantage of ease of application, and is safe to use.