Public Key-Based Authentication and En-Route Filtering Scheme in Wireless Sensor Networks.

The existing public key-based en-route filtering schemes are vulnerable to report disruption attacks or selective forwarding attacks, and they fail to consider any measure to detect and punish the malicious nodes. The authors propose a series of public key-based security mechanisms for wireless sensor networks (WSNs) in this paper, including a mechanism for verifying the partial signatures, a substitution mechanism, an effective report forwarding protocol, and a trust value-based mechanism to identify and punish the malicious nodes. Finally, the authors develop a public key-based authentication and en-route filtering scheme (PKAEF), which can resist false data injection attacks, report disruption attacks and selective forwarding attacks, and can mitigate the impact of malicious nodes. Detailed performance analysis and evaluation show that, in most cases, PKAEF outperforms previous works in terms of safety, filtering efficiency, and data availability.

[Segmental schwannomatosis in upper-extremity: 5 cases report and literature review].

OBJECTIVE: Multiple schwannomas localized in a single body part not crossing the midline constitute a rare variant of neurofibromatosis, segmental schwannomatosis. We report our experience with 5 cases of segmental schwannomatosis of the upper extremity and review the related literature to improve our skills in diagnosis and differentiation. METHODS: Five patients with segmental schwannomatosis received surgical treatment in our department from 2003 to 2012, of whom 4 were female and the other one male. The mean age was 38 years, ranging from 29 to 48 years. In retrospect, we discussed the clinical appearance, histologic characteristics, genetic data and surgical management. RESULTS: A total of 351 patients with schwannomas were treated in the recent decade. There were 326 patients with solitary schwannoma, accounting for 92.88%, 25 with neurofibromatosis type 2 (NF-2), occupying 7.12% and 5 with segmental schwannomatosis representing 1.42% of the total. Schwannomas are limited in one upper extremity and randomly located at ulnar nerve, median nerve and radial nerve and their branches, with no obvious predisposition. Their family history was negative for cutaneous tumors or central nervous system disease. Neurological examinations did not reveal symptoms related to vestibular nerves or optic nerves, which excluded NF-2 preliminarily. The prior symptom of three cases was pain which could be irradiated to the nerve distribution area. No pain but slight numbness was found in two cases. MRI disclosed multiple masses along the course of the nerves. They were isointense to muscle on T1-weighed images and hyperintense to subcutaneous fat on T2-weighed images. All schwannomas were resected and histological sections exhibited a characteristic feature of schwannoma. Follow-up work of 4.5 years was done to 4 cases and no recurrence or impairment of nerves was found. CONCLUSION: Segmental schwannomatosis is characterized by multiple schwannomas localized in one limb (upper extremity in our cases) without vestibular nerve tumors, most frequently seen in females at the age of 30-60 years. Segmental schwannomatosis is rarely seen in the previous literature. We found around 20 cases in English articles and no cases in domestic articles. In consideration of the clinical appearances of these 5 cases and the genetic research in the related literature, we recommend that segmental schwannomatosis is a distinct form of neurofibromatosis which needs to be more studied. We should also pay more attention to differentiating this disease from other forms of neurofibromatosis.

[An epidemiological investigation of acute occupational hand injuries].

OBJECTIVE: To study composition, distribution and causes of acute occupational hand injuries in Beijing Jishuitan Hospital. METHODS: From April 1st 2005 to September 30th 2005, all patients with acute hand injuries were investigated by questionnaire focusing on all related epidemiological elements. RESULTS: Two thousand six hundred fifty eight cases with acute hand injuries were about 17.3 % of patients with acute orthopedic injuries. Their mean age was (30.4 +/- 10.8) years old. The radio of males to females in cases with acute hand injuries was 57:1. The cutting and crushing injuries were the main causes of acute hand injuries. Most of cases with acute hand injuries were engaged in work related to machines. The acute hand injuries were mainly involved in index and middle figures of both hands, 94.9 % of acute hand injuries were opening, and 87.6% of acute hand injuries were involved in the deep tissues. CONCLUSION: Acute hand injuries are the common occupational severe injuries for young male workers. The acute hand injuries occur in patients engaged in work related to machines. The prevention of acute hand injuries should be emphasized.

[LONG-TERM RESULTS OF DELAYED REPAIR OF MEDIAN NERVE INJURY].

OBJECTIVE: To review and analyze the long-term results of delayed repair of median nerve injury. METHODS: Between January 2004 and December 2008, 228 patients with median nerve injury undergoing delayed repair were followed up for more than 4 years, and the clinical data were retrospectively analyzed. There were 176 males (77.19%) and 52 females (22.81%), aged 2-71 years (median, 29 years). The main injury reason was cutting injury in 159 cases (69.74%); 203 cases had open injury (89.04%). According to the injury level, injury located at area I (upper arm) in 38 cases (16.67%), at area II (elbow and proximal forearm) in 53 cases (23.25%), at area III (anterior interosseous nerve) in 13 cases (5.70%), and at area IV (distal forearm to wrist) in 124 cases (54.39%). The delayed operations included delayed suture (50 cases, 21.93%), nerve release (149 cases, 65.35%), and nerve graft (29 cases, 12.72%). RESULTS: For patients with injury at area I and area II, the results were good in 23 cases (25.27%), fair in 56 cases (61.54%), and poor in 12 cases (13.18%) according to modified Birch and Raji's median nerve grading system; there was significant difference in the results between 3 repair methods for injury at area II (χ2 = 6.228, P = 0.044), but no significant difference was found for injury at area I (χ2 = 2.241, P = 0.326). Twelve patients (13.18%) needed musculus flexor functional reconstruction. Recovery of thenar muscle was poor in all patients, but only 5 cases (5.49%) received reconstruction. Thirteen cases of nerve injury at area III had good results, regardless of the repair methods. For patients with injury at area IV, the results were excellent in 6 cases (4.84%), good in 22 cases (17.74%), fair in 72 cases (58.06%), and poor in 24 cases (19.35%) according to Birch and Raji's grading system; there was significant difference in the results between 3 repair methods (χ2 = 12.646, P = 0.002), and the result of delayed repair was better. CONCLUSION: The results of delayed repair is poor for all median nerve injuries, especially for high level injury. The technique of repair methods vary with injury level. For some delayed median nerve injuries, early nerve transfer may be a better choice for indicative patients.

Schwannomatosis: a new member of neurofibromatosis family.

BACKGROUND: Schwannomatosis is a recently recognized peripheral nerve polyneoplasm with clinical characteristics and a genetic background that differ from those of neurofibromatosis 2 (NF2). The diagnostic and treatment criteria of this rare disorder are herein discussed. METHODS: The data of 180 patients who underwent operations for benign schwannomas from 2003 to 2012 in our center were reviewed. Eight of them were classified as schwannomatosis according to the diagnostic criteria suggested by MacCollin. The demographic characteristics were documented and compared between the two groups of patients. The patients' clinical presentations, imaging characteristics, histological features, and treatment results were retrospectively investigated and summarized. RESULTS: Of the 180 cases of benign schwannomas we reviewed this time, eight patients presented with schwannomatosis (4.44%). The mean age of the two groups was not significantly different (40.0 vs. 44.7 years, t = 0.88, P = 0.378). However, schwannnomatosis seems to more generally occur in females (75% vs. 48% were females, P = 0.162), although the difference was not statistically significant. The initial main symptom was pain. The neurological examination was otherwise normal. Magnetic resonance imaging (MRI) revealed multiple discrete, well-defined round, or oval lesions distributed along the course of the peripheral nerves in the extremities with low-to-intermediate signal intensity on T1-weighted images and high-signal intensity on T2-weighted images. Vestibular schwannomas were excluded in four patients by cranial MRI. The lesions in all patients were resected and were pathologically proven to be schwannomas. The average follow-up period was 26 months. Six individuals obtained a good result without symptoms or function loss. CONCLUSIONS: Schwannomatosis is characterized by the development of multiple schwannomas without evidence of the vestibular tumors that are diagnostic for NF2. It commonly occurs in middle-aged females. It has similar demographic features to solitary benign schwannoma. Surgical resection always results in a good outcome.

[Epidemiological features of acute hand injuries in daily life in Beijing area].

OBJECTIVE: To study the composition, distribution, and influencing factors of acute hand injuries in daily life in the Beijing area by analyzing the clinical data from patients with acute hand injuries. METHODS: Between April 1st 2005 to September 30th 2005, 2575 patients with acute hand injuries in daily life from Beijing area were investigated by questionnaire. The epidemiological factors were analyzed, including gender, age, injury time, injury cause, accident place, injury mechanism, and location. RESULTS: The 2 575 patients injuried in daily life accounted for 49.2% of all. Most of them were young males, and the male to female ratio was 3.3:1. Most of the patients were 21-30 years old. The most common accident place was resting place (43.3%), and next was outdoors (28.8%) and leisure place (20.0%). Accidental injury was the major injury cause, accounted for 51.0%, followed by injury after drinking (16.1%) and violence (15.5%). The major injury mechanism was cutting (52.23%), followed by collision (16.04%) and falling (15.18%). A total of 2 405 patients were right hander, and handedness affected the distribution of injured hands significantly. Open injuries accounted for 70.7% of the patients, and the tissues in deep layer were involved in the injury in 54.4% of all. CONCLUSION: Hand injury in daily life is a common problem, which has its own epidemiological features. More appropriate measures should be taken to decrease the incidence.

Impaired nerve regeneration and Schwann cell activation after repair with tension.

The aim was to investigate the relation between axonal outgrowth (neurofilaments) and Schwann cell activation (activating transcription factor 3) and apoptosis (caspase 3) 10 days after nerve repair with no, minor (3 mm defect) and moderate (6 mm defect) tension in rat sciatic nerve using immunohistochemistry. After repair with no tension, axons grew 11.75 mm, but repair with minor and moderate tension impaired axonal outgrowth by 29 and 48%, respectively, with a reduced number of activating transcription factor 3 stained and an increased number of caspase 3 stained Schwann cells. Axonal outgrowth correlated with activation of and inversely with apoptosis of Schwann cells. Tension induces impaired activation of Schwann cells, and a higher amount of apoptotic Schwann cells, with a subsequent deteriorated axonal outgrowth.