The Handover and Performance Analysis of LTE Network with Traditional and SDN Approaches

The mobility of user equipment (UE) in cellular network is a challenging issue in terms of its management. Current traditional handover in Long-Term Evolution (LTE) network is managed by evolved Node B or eNodeB (eNB) which is a decentralized solution. In contrast to existing technology, software defined network (SDN) has the capability of serving the packets of the switching equipment without involving the SDN controller except for the first one. We have proposed an SDN-based centralized solution for handover management in LTE network. Based on our solution, the handover is being managed by SDN controller which keeps track of the overall network management and dictates the flow entries to the OpenFlow switches in the network. In our testbed, two UEs are connected to two eNBs, and one of the UE performs a handover from one eNB to other eNB. It enhances the performance of the network in terms of reducing the delay while performing the handover and increasing the data rate of the running application. The initial delay will be bit higher due to the initial flow entry absence in the flow tables of the switches; later, the delay will be reduced. It is evident from the results that our approach keeps track of the overall network at centralized controller with improved performance.

Doxorubicin-induced apoptosis in caspase-8-deficient neuroblastoma cells is mediated through direct action on mitochondria

The induction of p53 expression and stimulation of the Fas/caspase-8 pathway represent major mechanisms by which cytotoxic drugs induce apoptosis, but in neuroblastomas, the caspase-8 gene is often not expressed.

PURPOSE

The aim of this study was to determine whether doxorubicin could induce apoptosis in caspase-8-deficient neuroblastoma cells and to define its mechanism of action.

METHODS

The caspase-8-deficient human neuroblastoma cell line, SKN-SH, was incubated with doxorubicin and the apoptotic response, as well as expression of apoptotic molecules in the p53/ Fas/caspase-8 pathway, were determined.

RESULTS

SKN-SH cells incubated with doxorubicin readily underwent apoptosis in a concentration-dependent manner. Western blot analyses with specific antibodies demonstrated that both p53 and Fas ligand were endogenously expressed in SKN-SH cells, but their expression was not stimulated by doxorubicin. Fas receptor was not detected in these cells and caspase-8 was totally absent. Electron microscopic analyses of SKN-SH cells treated with doxorubicin revealed pronounced alterations in mitochondrial structure. This treatment also induced the release of cytochrome c from mitochondria and activated the downstream apoptotic intermediate, caspase-3.

CONCLUSION

These results indicate that the p53/Fas/caspase-8 system does not play a role in mediating the apoptotic action of doxorubicin in the human neuroblastoma cell line SKN-SH. Thus, mitochondria and downstream apoptotic signaling intermediates may be considered as key targets for doxorubicin-induced apoptosis in neuroblastoma tumors having deficiencies in the Fas/caspase-8 system.

Use of endoscopy in the management of postoperative ureterovaginal fistula

The aim of the study was to evaluate endourological techniques in the management of iatrogenic ureterovaginal fistula. Seventeen patients referred to us after gynecologic surgery were diagnosed as having iatrogenic ureterovaginal fistula. First, retrograde double-J stenting was tried. If this failed, percutaneous nephrostomy using an antegrade double-J stent was performed. If this also failed, open surgical repair was performed. The retrograde double-J stent bypassed the fistula in 2 patients (11.8%). Percutaneous nephrostomy was performed in the remaining 15. The antegrade double-J stent bypassed the fistula in another 2 of these patients (11.8%). Open surgical repair was performed in the remaining 13 patients (67.5%) (direct ureteroneocystostomy) with nipple valve in 11 patients and Boari flap with psoas hitch in 2 patients). Of all patients, 2 had ureteral stricture, one after antegrade double-J stenting and the other after open repair. It was concluded that early intervention is recommended in the treatment of iatrogenic uretrovaginal fistula, causing minimal morbidity and discomfort, and being less expensive.

Experience with penile fractures in Egypt: long-term results of immediate surgical repair

We present our experience in the management of 14 patients with fracture of the penis. The time between the injury and hospital arrival ranged from 2 to 12 hours. All the patients were managed by emergency surgical repair. Surgery consisted of complete evacuation of the hematoma and repair of the tear in the tunica albuginea. Urethral injury associated with penile fracture was not seen in this series. Follow-up time ranged from 12 to 78 months (average, 42.3 +/- 18.3). The results were excellent, with complete early recovery of erectile function. Slight penile curvature during erection was observed in two patients, but this did not affect their sexual activity. Because of these encouraging results and the reported high complication rate of conservative treatment, the need for immediate surgical repair is emphasized.