Purpose At 14:28 hours on May 12, 2008, a massive earthquake wracked most areas of Sichuan, China, causing catastrophic human loss. The aim of this study was to delineate the characteristics of ...victims with maxillofacial fractures in this disaster. Patients and methods A descriptive analysis was conducted based on the medical records of earthquake maxillofacial injuries casualties transferred to West China Hospital of Stomatology, Sichuan University, after the earthquake. Data regarding demographic details, psychological status, patterns, anatomic sites, etiology, concomitant injuries, and management of earthquake maxillofacial fractures were evaluated. Results A total of 46 maxillofacial fracture patients' records of 28 (60.9%) males and 18 (39.1%) females were included in this study, with peak incidence (32.6%) in the elderly age group (older than 50 years). The most common etiology of earthquake maxillofacial fractures was building collapse (71.7%). The mandible (65.2%) was the most frequent site of the maxillofacial fracture, followed by the zygomatic complex (21.7%) and maxilla (13.0%). The most prevalent of maxillofacial fracture pattern was multiple and/or comminuted fractures (56.5%), which accounted for 72.7% (24/33) in building collapse injury group. There were 9 (19.6%) patients with significant concomitant injuries and the most common site of concomitant injuries was the head (4 cases) and extremity (4 cases). Four (8.7%) patients' maxillofacial fractures were treated conservatively, 16 (34.8%) underwent closed reduction and fixation, and 26 (56.5%) underwent open reduction and rigid internal fixation (RIF). Apart from 3 patients (6.5%) who showed infection, all patients with facial fractures achieved successful bony union with an acceptable occlusion and facial form. Additionally, it is noteworthy that all patients in our study presented the symptoms of posttraumatic stress disorder (PTSD). Conclusion There is a variation of mechanism of injuries, age group, severity, patterns, concomitant injuries, and management of earthquake maxillofacial fractures. Knowledge of these characteristics provides useful strategies for patient care and prevention of further complications. A multidisciplinary and coordinated approach is important for optimum stabilization and ongoing treatment of victims of building collapse injury. The high percentage of PTSD confirms that psychologists should form an integral part of this multidisciplinary team.
The variable (V) regions of immunoglobulin heavy and light chains undergo high rates of somatic mutation during the immune response. Although point mutations accumulate throughout the V regions and ...their immediate flanking sequences, analysis of large numbers of mutations that have arisen in vivo reveal that the triplet AGC appears to be most susceptible to mutation. We have stably transfected B cell lines with γ 2a heavy chain constructs containing TAG nonsense codons in their V regions that are part of either a putative (T)AGC hot spot or a (T)AGA non-hot spot motif. Using an ELISA spot assay to detect revertants and fluctuation analysis to determine rates of mutation, the rate of reversion of the TAG nonsense codon has been determined for different motifs in different parts of the V region. In the NSO plasma cell line, the (T)AGC hot spot motif mutates at rates of ≈ 6 × 10-4/bp per generation and ≈ 3 × 10-5/bp per generation at residues 38 and 94 in the V region. At each of these locations, the (T)AGC hot spot motif is 20-30 times more likely to undergo mutation than the (T)AGA non-hot spot motif. Moreover, the AGA non-hot spot motif mutates at as high a rate as the hot spot motif when it is located adjacent to hot spot motifs, suggesting that more extended sequences influence susceptibility to mutation.
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