External RF-EMF alters cell number and ROS balance possibly via the regulation of NADPH metabolism and apoptosis.

The influence of weak radio-frequency electromagnetic field (RF-EMF) on living organisms raises new concern because of the Industrial, Scientific, and Medical (ISM) frequency band at 6.78 MHz being promoted by the AirFuel Alliance for mid-range wireless power transfer (WPT) applications and product development. Human exposure to the RF-EMF radiation is unavoidable. In this study, we employed in vitro cell culture and molecular biology approach coupled with integrated transcriptomic and proteomic analyses to uncover the effects of RF-EMF on cells at molecular and cellular levels. Our study has demonstrated that weak RF-EMF is sufficient to exert non-thermal effects on human umbilical vein endothelial cells (HUVEC). Exposure of weak RF-EMF promotes cell proliferation, inhibits apoptosis and deregulates ROS balance. Alteration of several signaling pathways and key enzymes involved in NADPH metabolism, cell proliferation and ferroptosis were identified. Our current study provide solid evidence for the first time that the present safety standards that solely considered the thermal effect of RF-EMF on cell tissue are inadequate, prompt response and modification of existing Guidelines, Standards and Regulation are warranted.

Free posterior tibial flap for head and neck reconstruction after tumor expiration.

BACKGROUND: Similar to the radial forearm flap, free tissue transfer of a fasciocutaneous flap is possible if the septocutaneous perforators of the posterior tibial vessels are preserved. OBJECTIVE: The authors report their clinical experience on using the free posterior tibial flap for primary reconstruction of head and neck defects after tumor extirpation. METHODS: Eleven patients were included between October of 2005 and March of 2007. Patients' clinical and demographic data were collected. The flap harvesting results and outcomes were retrospectively reviewed. Representative cases are presented for illustration. RESULT: There were nine men and two women, and their ages ranged from 34 to 83 (mean, 60.3) years. The flaps measured from 6 x 9 cm to 8 x 12 cm. Two cutaneous perforators were included in the majority of cases. The average flap thickness was 0.7 cm, and the average pedicle length was 14 cm. Flap survival was 100%. Skin grafts of all donor sites healed well. All patients were ambulatory early in the postoperative period, and there was no distal limb ischemia or cold intolerance on follow-up. Four patients needed postoperative adjuvant radiotherapy. CONCLUSION: Our study demonstrates that the posterior tibial flap is a safe and reliable flap for reconstruction of head and neck defects after tumor expiration. It has all the comparable properties of a radial forearm flap. In addition, a larger area of skin can be removed, and the graft donor site is less conspicuous.

Clinical implications of anterolateral thigh flap shrinkage.

OBJECTIVE: To evaluate anterolateral thigh flap shrinkage after elevation and to develop a predictive model for flap design. METHOD: A prospective study was conducted in a university teaching hospital. The skin islands from anterolateral thigh flaps were outlined on a transparent sheet before and after the reconstruction procedure. Dimensions of the stretched flaps were also recorded. These three outlines were scanned and the surface areas computed and compared by tracing and use of AutoCAD. Age, sex, flap dimension, and flap thickness were investigated for association with flap shrinkage. RESULTS: Forty-five anterolateral thigh flaps harvested for head and neck soft tissue reconstruction after tumor resection were studied. Flap size ranged from 4 to 14 cm in width and 8 to 22 cm in length; flap area ranged from 30.6 to 151.0 cm. On average, the flaps shrunk by 25.0% (6.2%-52.6%), a highly significant change (P < .01). Flap width and thickness correlated with the reduction in flap size. The average stretched-flap area was 10.1% (0.4%-29.4%) less than the preflap area, a significant reduction (P < .01). The difference between stretched-flap and preflap areas was independent of all variables. We developed a predictive model using a stepwise multiple linear regression method with a coefficient of determination of 0.495. CONCLUSIONS: Anterolateral thigh flaps shrink after harvesting, and flap width and thickness are significant contributing variables. These findings indicate that flap size must take shrinkage into account to ensure sufficient coverage.

A modification of technique to cover a large posterior thigh defect using an anterolateral thigh flap.

Anterolateral thigh (ALT) flap is one of the popular flaps for soft-tissue reconstruction. It is a versatile flap which commonly used to resurface external skin defect and internal mucosal lining. In addition if raised as musculocutaneous flap, the muscle portion provides bulk to fill up any potential space. With increase knowledge on the vascular anatomy of this flap, it is possible to harvest 2 skin paddles base on more than one branches of the supplying vessel. This technique is commonly employed to provide coverage of more than one epithelial surfaces such as the complex facial defect after maxillectomy where both the cheek skin and oral mucosa reconstruction are required. Using similar concept, we report a case in which a large external skin defect was successfully covered with an ALT flap and the donor site could be closed primarily without skin grafting.

Radiation ulcers of the neck should not be neglected: a case of vertebral artery blowout.

Radiotherapy for head and neck malignancies can result in late complications. Here, we report a patient with a rare vascular complication caused by radiation-induced ulcer of the head and neck region. The clinical presentation, its diagnosis, treatment and outcome are discussed.

Quality of life of patients with recurrent nasopharyngeal carcinoma treated with nasopharyngectomy using the maxillary swing approach.

OBJECTIVE: To investigate factors affecting the quality of life (QOL) of patients with recurrent nasopharyngeal carcinoma who underwent a nasopharyngectomy using the maxillary swing approach. DESIGN: Cross-sectional study using self-administered questionnaire data and medical chart review. SETTING: Tertiary cancer referral center. PATIENTS: Patients with recurrent nasopharyngeal carcinoma who underwent a nasopharyngectomy using the maxillary swing approach between January 1998 and December 2003, had a minimal follow-up of 3 months, and completed the questionnaire. INTERVENTIONS: We measured QOL using the validated traditional Chinese version of the European Organization for Research and Treatment of Cancer core questionnaire and head and neck module. MAIN OUTCOME MEASURES: Descriptive analysis of the results and comparison of scores for each QOL domain, stratified by presence of postoperative trismus, presence of postoperative palatal fistula, sex, age (< or = 45 years and > 45 years), duration of treatment (< or = 1 year and > 1 year), and disease status at follow-up, were performed using nonparametric tests. RESULTS: Of the 50 eligible patients, 41 (32 men and 9 women; mean [SD] age, 51.5 [10.4] years) participated in the study. The mean +/- SD global QOL scale score of the participants was 68.7 +/- 24.2. Social functioning score was the lowest (64.6 +/- 25.9) of the 5 functioning scales. Fatigue and financial difficulties were the most common general concerns. Dryness of mouth, sticky saliva, and limited mouth opening were the most common head and neck problems. Women were found to have significantly lower QOL scores in the fatigue (P = .03), diarrhea (P = .03), and emotional functioning (P = .05) domains than men. The presence of severe trismus after the maxillary swing approach was significantly associated with a low QOL score in the mouth opening (P = .001), sticky saliva (P = .006), mouth dryness (P = .02), and social eating (P = .05) domains. However, the presence of palatal fistula, age, duration of treatment, and disease status at follow-up did not result in any significant differences on the QOL scores. CONCLUSIONS: The QOL of patients treated with nasopharyngectomy using the maxillary swing approach to treat recurrent nasopharyngeal carcinoma was good. Female sex and the presence of postoperative trismus were factors significantly related to some of the QOL domain differences after surgery.

Significance of MAD2 expression to mitotic checkpoint control in ovarian cancer cells.

Chromosome instability is a commonly observed feature in ovarian carcinoma. Mitotic checkpoint controls are thought to be essential for accurate chromosomal segregation, and MAD2 is a key component of this checkpoint. In this study, we investigated the competence of the mitotic checkpoint and its relationship to the expression of MAD2 protein in seven ovarian cancer cell lines. We found that a significant number (43%, three of seven cell lines) of the tested ovarian cancer cells failed to arrest in the G(2)-M phase of the cell cycle in response to microtubule disruption. This loss of mitotic checkpoint control was associated with reduced expression of the MAD2 protein. To additionally understand the significance of the MAD2 to mitotic checkpoint control, we established an inducible expression system in which MAD2 was induced by the addition of ponasterone A. Notably, the induced expression of MAD2 in two checkpoint-defective ovarian cancer cell lines led to the restoration of mitotic checkpoint response to spindle-disrupting agents. Taken together, our findings suggest that the steady-state amount of MAD2 inside cells may represent a molecular switch for mitotic checkpoint control. This provides a novel insight into the molecular basis of CIN in ovarian carcinoma and has implications for effective use of checkpoint-targeting drugs.

Differential expression, localization and activity of two alternatively spliced isoforms of human APC regulator CDH1.

The timely destruction of key regulators through ubiquitin-mediated proteolysis ensures the orderly progression of the cell cycle. The APC (anaphase-promoting complex) is a major component of this degradation machinery and its activation is required for the execution of critical events. Recent studies have just begun to reveal the complex control of the APC through a regulatory network involving WD40 repeat proteins CDC20 and CDH1. In the present paper, we report on the identification and characterization of human CDH1beta, a novel alternatively spliced isoform of CDH1. Both CDH1alpha and CDH1beta can bind to the APC and stimulate the degradation of cyclin B1, but they are differentially expressed in human tissues and cells. CDH1alpha contains a nuclear localization signal which is absent in CDH1beta. Intracellularly, CDH1alpha appears in the nucleus whereas CDH1beta is a predominantly cytoplasmic protein. The forced overexpression of CDH1alpha in cultured cells correlates with the reduction of nuclear cyclin A, but the steady-state amount of cyclin A does not change noticeably in CDH1beta-overexpressed cells. In Xenopus embryos, ectopic overexpression of human CDH1alpha, but not of CDH1beta, induces cell-cycle arrest during the first G(1) phase at the mid-blastula transition. Taken together, our findings document the differential expression, subcellular localization and cell-cycle-regulatory activity of human CDH1 isoforms.

Insertion of Provox2 voice prosthesis using the anterograde technique immediately after the secondary tracheoesophageal puncture.

Insertion of a voice prosthesis through the tracheoesophageal puncture (TEP) is one way to restore the voice after total laryngectomy. The second generation Provox voice prosthesis is presently one of the most popular devices. Although TEP can be done primarily, there are many centres that prefer it to be done at a second stage for various reasons. However, secondary TEP for retrograde replacement of prosthesis can be difficult and general anaesthesia is very often necessary. Moreover, the presence of neck stiffness and fibrosis from the surgery or previous radiotherapy could affect the neck extension for proper positioning of the trocar. Similarly, it is difficult to insert the prosthesis if there is stenosis at the pharyngoesophageal segment. We describe a technique in which creation of secondary TEP and insertion of Provox2 is done with local anaesthesia under the same setting. The procedure is well tolerated and can be safely performed on an out-patient basis.

Pharyngeal entry through the vallecula.

The authors describe a technique of entry into the vallecula with the guide of a small Deaver retractor inserted transorally, beyond the tongue base, into the vallecula. The tip of the Deaver directs the surgeon to the pharyngotomy site and allows pharyngeal entry and access without damaging structures in the region. This technique is particularly useful in total laryngectomy with or without pharyngectomy and is applicable whenever entry to the pharynx through the vallecula is indicated.

Safe tracheostomy for patients with severe acute respiratory syndrome.

OBJECTIVES/HYPOTHESIS: Severe acute respiratory syndrome (SARS) caused by coronavirus has become an epidemic affecting many regions worldwide. Fourteen percent to 20% of patients require endotracheal intubation and ventilator support. Some of these patients may require tracheostomy subsequently. This procedure, when performed without protection, may lead to infection of the medical and nursing staff taking care of the patient. STUDY DESIGN: Based on clinical information of three patients. METHODS: The authors carried out an emergency tracheostomy and changed the tracheostomy tube for one patient and performed elective tracheostomy in another two patients. RESULTS: No medical or nursing staff member was infected after carrying out the procedure while taking all the precautions and wearing the appropriate protective apparel. CONCLUSION: The authors have prepared guidelines for performing a safe tracheostomy under both elective and emergency conditions. Surgeons who might be involved in performing the tracheostomy should become familiar with these guidelines and the appropriate protective apparel.

Microvascular free tissue reconstruction following extirpation of head and neck tumour: experience towards an optimal outcome.

Familiarity with four types of free tissues transfers allows appropriate reconstruction of most defects in the head and neck region functionally and aesthetically. These include jejunal graft, radial forearm, rectus abdominus myocutaneous and fibula osteocutaneous flaps. Free colonic and gastric patches were used occasionally. We report our experience of 215 free tissue transfers for reconstruction of defects in the head and neck region after tumour extirpation. The overall success rate was 94 per cent. The commonest cause of failure was related to arterial inflow (70 per cent). Three patients died in hospital, but their mortality was not related to the tissue transfers. Complications due to free tissue transfer at both the donor and recipient sites were few and manageable. The co-operation between the two surgical teams, together with the timely application of suitable salvage procedures, contribute to an optimal outcome.

Aesthetic considerations in the cervicofacial management of Madelung syndrome.

The most common concern in patients with Madelung syndrome who are seeking cosmetic improvement is the deposition of fat in the cervicofacial region. Surgical experience in a series of 15 patients was summarised to provide guidelines for a rational approach to a better aesthetic outcome. The records and clinical photographs of these patients were reviewed. Outcome was assessed in terms of adequacy of debulking, final overall symmetry, smoothness of contour, prominence of scar, and necessity for multiple sessions. Open excision was the preferred primary treatment. A long mid-neck, transverse skin crease incision provided good exposure and was superior to multiple local incisions. Other surgical details worth noting include subplatysmal dissection, thick skin flaps, dissection around instead of into lipomas, appropriate removal of redundant skin, adequate reduction of tumour size instead of total excision, haemostasis, suction drainage, and layered skin closure. Liposuction was a useful adjunct for contouring the sides of the jaws in selected patients.

Clinical use of a pedicled anterolateral thigh flap.

BACKGROUND: Anterolateral thigh flap is a safe and reliable flap for soft tissue reconstruction. It has successfully been used as free flap reconstruction for defects in the head and neck region, the upper extremities and lower extremities. However, there were only a few reports in the literature concerning the clinical application of this flap for regional reconstruction. METHODS: The authors describe their experience of using the pedicled island anterolateral thigh flap for reconstruction of soft tissue defects in neighbouring areas. Representative cases are presented for illustration. RESULT: Between July 2005 and September 2006, seven patients underwent an immediate reconstruction with pedicled anterolateral thigh flap. The patients were between 49 and 69 years old. The size of the flaps measured from 5 x 8 cm to 15 x 15 cm. They were prepared as myocutaneous flaps in three cases and as perforator flaps in four cases. One patient, who had the largest flap harvested, needed skin grafting of the donor site. Primary closure was performed for all other cases. All flaps survived without any vascular compromise and the donor site healed without complication. CONCLUSION: Our study has shown that the pedicled anterolateral thigh flap is a safe and reliable flap for repair of defects at the internal pelvis, lateral thigh, groin, and genitoperineal region. The long vascular pedicle and having no restriction to the arc of rotation are keys to the successful transposition of the flap for immediate reconstruction of soft tissue defects in neighbouring areas.

Complications of resection of malignant tumours of the skull base: outcome and solution.

The results of surgical resection of malignant tumours located at the skull base have improved significantly over the years. There are however still some complications associated with these procedures. For central skull base lesions, the anterolateral approach exposes the region adequately for an oncological resection to be carried out. The development of palatal fistula in irradiated patient has been a nuisance. With modification of the palatal incision, this problem is now eliminated. For the management of osteoradronecrosis of the skull base, an uncommon late complication, a microvascular free muscle flap is required. For malignant pathologies located at the anterior skull base, a combined craniofacial resection is the treatment of choice. Our experience as well as those reported in the literature showed that when the skull base defect was small, the pericranial and the galeofrontalis flap were adequate for reconstruction. For larger defects, a microvascular free flap would be used. When the internal carotid artery is included in the resection, an extracranial-intracranial arterial bypass should be created before the resection of tumour. The most serious complication is the development of cerebral spinal fluid leakage. Conservative treatment is applicable for small leakage while for large leakage; the exact location of the leak must be identified before the defect can be closed successfully.

Elimination of palatal fistula after the maxillary swing procedure.

BACKGROUND: The maxillary swing procedure has been used as an anterolateral approach to expose the nasopharynx, the central skull base, and its vicinity. The reported incidence of postoperative palatal fistula has ranged from 20% to 25%. The oronasal incompetence especially associated with a large fistula has adversely affected normal speech, eating, and swallowing functions. We describe a modified palatal incision to reduce the incidence of palatal fistula associated with the maxillary swing procedure. METHODS: Fifteen consecutive patients who underwent maxillary swing procedures for salvage resection of recurrent nasopharyngeal carcinoma after radiotherapy had the modified palatal incision. The flap was raised as described, and the outcome was analyzed. RESULTS: Fourteen patients' palatal wound healed uneventfully. One patient experienced partial flap necrosis, which healed with conservative treatment. All 15 patients tolerated oral feeding 1 week after the surgery. No palatal fistulas occurred. CONCLUSION: The modified palatal incision as described has effectively prevented palatal fistula formation after the maxillary swing procedure.

The APC regulator CDH1 is essential for the progression of embryonic cell cycles in Xenopus.

The orderly progression of cell cycle depends on timely destruction of key regulators through ubiquitin-mediated proteolysis. The anaphase-promoting complex (APC) is a major component of this degradation machinery and its activation is regulated by CDC20 and CDH1. We demonstrate here that CDH1 mRNA is ubiquitously expressed in Xenopus embryos of all developmental stages. Loss of CDH1 function during early embryonic cell cycles leads to an immediate and prolonged arrest with low cyclin-dependent kinase activity. In contrast, ectopic overexpression of CDH1 induces cell cycle arrest during the first G(1) phase at the midblastula transition. CDH1-dependent degradation of cyclin A is likely involved in this G(1) arrest. Our findings establish the essential roles of CDH1 in embryonic cell cycles.