Quantitative Multiplex Immunohistochemistry Reveals Myeloid-Inflamed Tumor-Immune Complexity Associated with Poor Prognosis.

Here, we describe a multiplexed immunohistochemical platform with computational image processing workflows, including image cytometry, enabling simultaneous evaluation of 12 biomarkers in one formalin-fixed paraffin-embedded tissue section. To validate this platform, we used tissue microarrays containing 38 archival head and neck squamous cell carcinomas and revealed differential immune profiles based on lymphoid and myeloid cell densities, correlating with human papilloma virus status and prognosis. Based on these results, we investigated 24 pancreatic ductal adenocarcinomas from patients who received neoadjuvant GVAX vaccination and revealed that response to therapy correlated with degree of mono-myelocytic cell density and percentages of CD8+ T cells expressing T cell exhaustion markers. These data highlight the utility of in situ immune monitoring for patient stratification and provide digital image processing pipelines to the community for examining immune complexity in precious tissue sections, where phenotype and tissue architecture are preserved to improve biomarker discovery and assessment.

Difficult airway response team: a novel quality improvement program for managing hospital-wide airway emergencies.

BACKGROUND: Difficult airway cases can quickly become emergencies, increasing the risk of life-threatening complications or death. Emergency airway management outside the operating room is particularly challenging. METHODS: We developed a quality improvement program-the Difficult Airway Response Team (DART)-to improve emergency airway management outside the operating room. DART was implemented by a team of anesthesiologists, otolaryngologists, trauma surgeons, emergency medicine physicians, and risk managers in 2005 at The Johns Hopkins Hospital in Baltimore, Maryland. The DART program had 3 core components: operations, safety, and education. The operations component focused on developing a multidisciplinary difficult airway response team, standardizing the emergency response process, and deploying difficult airway equipment carts throughout the hospital. The safety component focused on real-time monitoring of DART activations and learning from past DART events to continuously improve system-level performance. This objective entailed monitoring the paging system, reporting difficult airway events and DART activations to a Web-based registry, and using in situ simulations to identify and mitigate defects in the emergency airway management process. The educational component included development of a multispecialty difficult airway curriculum encompassing case-based lectures, simulation, and team building/communication to ensure consistency of care. Educational materials were also developed for non-DART staff and patients to inform them about the needs of patients with difficult airways and ensure continuity of care with other providers after discharge. RESULTS: Between July 2008 and June 2013, DART managed 360 adult difficult airway events comprising 8% of all code activations. Predisposing patient factors included body mass index >40, history of head and neck tumor, prior difficult intubation, cervical spine injury, airway edema, airway bleeding, and previous or current tracheostomy. Twenty-three patients (6%) required emergent surgical airways. Sixty-two patients (17%) were stabilized and transported to the operating room for definitive airway management. There were no airway management-related deaths, sentinel events, or malpractice claims in adult patients managed by DART. Five in situ simulations conducted in the first program year improved DART's teamwork, communication, and response times and increased the functionality of the difficult airway carts. Over the 5-year period, we conducted 18 airway courses, through which >200 providers were trained. CONCLUSIONS: DART is a comprehensive program for improving difficult airway management. Future studies will examine the comparative effectiveness of the DART program and evaluate how DART has impacted patient outcomes, operational efficiency, and costs of care.

Inhaled triamcinolone with proton pump inhibitor for treatment of vocal process granulomas: a series of 67 granulomas.

OBJECTIVES: We sought to analyze the outcomes of vocal process granulomas treated with proton pump inhibitors and inhaled triamcinolone acetonide. METHODS: We reviewed the medical records of patients with a diagnosis of contact granuloma or vocal process granuloma between 1995 and 2008. Data included age, gender, intubation history, reflux history, lesion location, previous treatment methods, treatment course, and recurrence. All patients were treated with daily or twice-daily protein pump inhibitors and inhaled triamcinolone acetonide (300 microg 3 times a day). RESULTS: Sixty-seven granulomas were diagnosed in 54 patients: 13 bilateral and 41 unilateral. Twenty patients, including all 11 women, had a recent history of intubation. Sixty-two granulomas in 50 patients were treated with triamcinolone and a proton pump inhibitor. Of the 57 granulomas that completed treatment, 5 (9%) did not respond (mean follow-up, 50 weeks; range, 30.3 to 78.3 weeks), 13 (22%) partially responded (mean follow-up, 11 weeks; range, 3 to 30 weeks), and 40 (69%) completely responded (mean follow-up, 21 weeks; range, 5.9 to 84.6 weeks). Three cases had recurrence: 2 nonresponders and 1 complete responder. One patient developed oral thrush. CONCLUSIONS: In this study, vocal process granulomas occurred more frequently in men, whereas women developed granulomas only after intubation. The anti-inflammatory action of inhaled triamcinolone combined with antireflux proton pump inhibitors successfully treats most vocal process granulomas with low rates of side effects and recurrence.

Characterization of human papillomavirus type 11-specific immune responses in a preclinical model.

OBJECTIVES/HYPOTHESIS: Human papillomavirus (HPV) types 6 and 11 are associated with recurrent respiratory papillomatosis (RRP). Although a prophylactic vaccine has been developed that protects against HPV infection, a therapeutic vaccine is still needed for those patients infected with and/or suffering from persistent disease. Therefore, we developed a novel, therapeutic DNA vaccine targeting HPV-11 and characterized the in vivo immunologic responses generated against HPV-11 E6 and E7 after DNA vaccination in a preclinical model. METHODS: We generated a DNA vaccine that encodes the HPV-11 E6 and E7 genes in a pcDNA3 backbone plasmid. We then vaccinated C57BL/6 mice with the pcDNA3-HPV11-E6E7 DNA plasmid. Splenocytes were harvested from these vaccinated animals and were incubated with overlapping peptides spanning either the HPV-11 E6 or E7 protein. The frequency of interferon-gamma-releasing CD8(+) T cell responses was then analyzed by flow cytometry. RESULTS: Vaccinated mice with the HPV11-E6E7 DNA generated strong CD8(+) T cell responses against the E6(aa44-51) peptide. We determined that the epitope is presented by the MHC class I H2-K(b) molecule. No significant E7 peptide-specific T cell responses were observed. CONCLUSIONS: We developed a novel DNA vaccine that targets the E6 gene of HPV-11. Characterization of the immunologic responses elicited by this DNA vaccine reveals that the E6(aa44-51) peptide contains the most immunogenic region for the HPV-11 viral type. Knowledge of this specific T cell epitope and generation of a RRP preclinical model will allow for the development and evaluation of novel vaccine strategies targeting the RRP patient population.

Complications that affect postlaryngectomy voice restoration: primary surgery vs salvage surgery.

OBJECTIVE: To assess the effect of primary treatment on tracheoesophageal voice prosthesis (TEP) complications. DESIGN: Retrospective cohort study. SETTING: The Johns Hopkins Medical Institutions, Baltimore, Maryland. PATIENTS: Patients who underwent total laryngectomy and TEP between January 1, 1998, and December 31, 2008, were divided into 3 subgroups according to primary treatment: surgery (n = 81), radiotherapy (n = 61), and chemoradiotherapy (n = 32). MAIN OUTCOME MEASURES: Number of weeks before leakage through the TEP, occurrence of leakage around the TEP, TEP dislodgement, and size changes 6 months or longer after laryngectomy. RESULTS: A total of 174 patients met the study criteria. Of the 81 patients who underwent primary surgery, 81% (n = 66) underwent adjuvant therapy with postoperative radiotherapy or chemoradiotherapy. The incidence of leakage around the prosthesis, prosthesis dislodgement, and size changes 6 months or longer after laryngectomy were significantly higher for patients who required salvage total laryngectomy after chemoradiotherapy or radiotherapy (P < .05). In addition, significantly more patients who underwent salvage total laryngectomy required extended laryngectomy or free tissue reconstruction. CONCLUSIONS: Voice prosthesis complications are more frequently encountered in those who require salvage laryngectomy. Understanding the potential for such complications reinforces the need for close communication and follow-up with these patients by the speech language pathologist.

Need for emergency surgical airway reduced by a comprehensive difficult airway program.

BACKGROUND: Inability to intubate and ventilate patients with respiratory failure is associated with significant morbidity and mortality. A patient is considered to have a difficult airway if an anesthesiologist or other health care provider experienced in airway management is unable to ventilate the patient's lungs using bag-mask ventilation and/or is unable to intubate the trachea using direct laryngoscopy. METHODS: We performed a retrospective review of a departmental database to determine whether a comprehensive program to manage difficult airways was associated with a reduced need to secure the airway surgically via cricothyrotomy or tracheostomy. The annual number of unplanned, emergency surgical airway procedures for inability to intubate and ventilate reported for the 4 yr before the program (January 1992 through December 1995) was compared with the annual number reported for the 11 yr after the program was initiated (January 1996 through December 2006). RESULTS: The number of emergency surgical airways decreased from 6.5 +/- 0.5 per year for 4 yr before program initiation to 2.2 +/- 0.89 per year for the 11-yr period after program initiation (P < 0.0001). During the 4-yr period from January 1992 through December 1995, 26 surgical airways were reported, whereas only 24 surgical airways were performed in the subsequent 11-yr period (January 1996 through December 2006). CONCLUSIONS: A comprehensive difficult airway program was associated with a reduction in the number of emergency surgical airway procedures performed for the inability of an anesthesiologist to intubate and ventilate, a reduction that was sustained over an 11-yr period. This decrease occurred despite an increase in the number of patients reported to have a difficult airway and an overall increase in the total number of patients receiving anesthesia per year.

A practical framework for patient care teams to prospectively identify and mitigate clinical hazards.

BACKGROUND: One of the greatest challenges facing both practitioners and risk managers is the identification of previously unknown clinical hazards and defects. With the rapid proliferation of new health care services, unknown hazards may propagate as new therapies are integrated into the existing health care system. The main goal of risk analysis is to make these hazards visible by proactively searching and probing the system. Yet, a comprehensive approach by which to safely integrate new therapies into the existing clinical environment has yet to be clearly articulated. Patient care teams can use the proposed framework when introducing new therapies. A PRACTICAL FRAMEWORK: The framework includes a background investigation and literature search; an in situ simulation (in the actual clinical setting used for patients); a Failure Mode and Effects Analysis to determine the severity, probability, and risk of the potential hazards; and a multidisciplinary protocol and safety checklist to standardize practice and ensure provider accountability. CASE EXAMPLES: Application of this framework to three operative scenarios--intraoperative radiation therapy (IORT), hyperthermic intraperitoneal chemotherapy (HIPEC), and an interventional pulmonology program--demonstrates its flexibility. Its use prospectively identified and mitigated 20 IORT, 5 HIPEC, and 18 interventional pulmonology hazards/defects. Subsequent patient cases were largely uneventful. All cases and patient safety reporting systems are monitored to identify any new defects in an effort to continuously improve patient care. CONCLUSION: The use of a comprehensive framework to identify and mitigate hazards in an on-site simulated environment promotes safer care for target patient populations; results in familiarity with procedures, amelioration of staff concerns, and standardization of practice; and facilitates teamwork and communication.

Evolution of endoscopic surgical therapy for Zenker's diverticulum.

Zenker's diverticulum is a rare anatomic defect that physicians have confronted for almost 250 years. Its location at the interface of the pharynx, neck, and mediastinum makes surgical access difficult and risks severe morbidity. Minimally invasive endoscopic surgical repair of Zenker's diverticulum has been attempted for more than a century as an alternative to reduce morbidity of an open transcervical approach. However, limitations due to available antibiotics, instrumentation, and laryngoscopes, as well as a general discomfort with a sutureless closure of the mucosal excision, have delayed widespread adoption of minimally invasive repair until the last 10 to 15 years. This manuscript will detail the historical evolution of endoscopic surgical therapy for Zenker's diverticulum and highlight the work of two otolaryngologists, Chevalier Jackson and Gosta Dohlman, who were critical in advancing the surgical technique and reducing morbidity. Lastly, this manuscript will analyze the delay in widespread application of endoscopic surgical repair of Zenker's diverticulum.

Supracricoid laryngectomy outcomes: The Johns Hopkins experience.

OBJECTIVE: To report the oncologic and functional results from our experience in performing supracricoid laryngectomy (SCL) for selected patients with laryngeal cancer. STUDY DESIGN: Retrospective chart review. METHODS: Twenty-four consecutive patients who underwent SCL for laryngeal cancer in our institution from December 2000 to March 2006 have been reviewed. Reports of the site and extent of tumor, type of reconstruction, preoperative or postoperative radiotherapy, and the final histopathologic examination were reviewed. In addition, the reports of the preoperative examination, inpatient course, and postoperative follow-up were reviewed. RESULTS: A total of 24 patients were involved in the study; 19 had tumors involving the glottic region, and 5 patients had tumors involving both the glottic and supraglottic regions (transglottic). Ten patients had their SCL for postradiotherapy recurrence/persistence of disease. Eighteen patients underwent reconstruction through cricohyoidoepiglottopexy (CHEP), whereas six patients had cricohyoidopexy (CHP). Eleven patients had an arytenoid cartilage resected; 8 of 11 had CHEP, and 3 of 11 had CHP. All patients had a tracheostomy and percutaneous endoscopic gastrostomy (PEG) tube placement performed at the same time as the SCL. The median hospital stay period was 6 days. Twenty-three of 24 had successful tracheostomy tube decannulation, with a median time to decannulation of 37 days. The median time to removal of the PEG tube was 70 days. The complications with SCL were postoperative wound infection in two patients (SCL/CHP) and the need for completion total laryngectomy secondary to intractable aspiration in one patient with SCL/CHP. One patient with SCL/CHEP had a ruptured pexy and subsequently underwent a second reconstruction with successful tracheostomy and PEG tube removal. One of 24 patients is still PEG tube dependant, and he had postoperative radiotherapy. Fifteen patients underwent concurrent neck dissection. None of the patients had any local or regional recurrence, with a median follow-up period of 3 years. All final surgical margins were negative for tumor invasion. Three patients had postoperative radiotherapy, two patients because of nodal metastases in the excised lymph nodes and one because of perineural invasion on final histopathologic examination of the SCL specimen. There were no perioperative deaths. CONCLUSION: SCL with CHEP or CHP represents an effective technique that can be taught and effectively used to avoid a total laryngectomy while maintaining physiologic speech and swallowing in selected patients with advanced stage primary laryngeal cancer or recurrent/persistent laryngeal cancer after radiotherapy. There is a good functional recovery with acceptable morbidity and an excellent oncologic outcome when strict selection criteria are applied and a formal swallowing rehabilitation program is followed.

Importance of routine evaluation of the thyroid gland prior to open partial laryngectomy.

OBJECTIVES: To determine the incidence and presentation of synchronous thyroid lesions in a patient population undergoing open partial laryngectomy (OPL), and to determine whether routine preoperative evaluation of the thyroid gland prior to OPL is useful to identify synchronous thyroid lesions in order to reduce the need for reoperation in this complex patient population. DESIGN: Retrospective medical chart review. SETTING: Academic institution. PATIENTS: Sixty-seven consecutive patients with laryngeal tumors who had undergone OPL from 1996 to 2005. INTERVENTIONS: Charts of 67 consecutive patients with laryngeal tumors who underwent OPL in 1996 to 2005 have been reviewed for synchronous thyroid lesions. For all patients, reports of (1) complete preoperative examination findings, (2) inpatient course, (3) postoperative follow-up, and (4) postoperative final histopathologic findings were reviewed. For patients with synchronous thyroid lesions, reports of (1) thyroid evaluation and imaging and (2) preoperative (fine-needle aspiration), (3) intraoperative (frozen section), and (4) postoperative (final) histopathologic results for the thyroid lesions were reviewed. MAIN OUTCOME MEASURES: Incidence of synchronous thyroid lesions and laryngeal cancer in patients undergoing OPL. RESULTS: Eight (11.9%) of 67 (95% confidence interval, 5.3%-22.2%) patients with laryngeal tumors who underwent OPL had evidence of synchronous thyroid lesions. All 8 patients had squamous cell carcinoma of the larynx and underwent either supracricoid or supraglottic laryngectomy. In these 8 patients, synchronous thyroid lesions were incidentally detected. Four patients had papillary thyroid carcinoma, 1 had squamous metaplasia, and 3 had follicular thyroid tissue that was negative for malignancy on final pathologic examination. In 2 patients, the thyroid lesions were detected preoperatively (prior to OPL); in another 2 patients, thyroid masses were detected intraoperatively; and in 4 patients, the thyroid disease was identified postoperatively on histopathologic examination of excised cervical lymph nodes. In 2 patients, thyroidectomy was performed as a second operation after the OPL, and 1 of them had transient vocal fold paralysis for 2 months. Thyroid ultrasonography was performed in 4 patients. In 3 patients, the ultrasonography was performed after the OPL final pathologic findings indicated the presence of metastatic thyroid disease in cervical lymph nodes. Ultrasonography revealed intrathyroidal lesions in all 3 patients. CONCLUSIONS: Patients with laryngeal tumors who will be undergoing OPL might have occult synchronous thyroid lesions. Thyroid surgery in patients with previous OPL may have an increased potential for complication owing to postsurgical changes in the central neck region. Routine preoperative evaluation of the thyroid gland, especially with ultrasonography, to screen for occult synchronous thyroid lesions is recommended for all patients with laryngeal tumors who will be undergoing OPL. Eradication of any thyroid cancer detected preoperatively by fine-needle aspiration should be performed at the same time as OPL. Pros and cons of total thyroidectomy for indeterminate thyroid nodules should be discussed with this patient population.

Neck management in patients undergoing postradiotherapy salvage laryngeal surgery for recurrent/persistent laryngeal cancer.

OBJECTIVE: To determine a plan for the management of cervical lymph nodes in patients undergoing salvage laryngeal surgery (SLS) for recurrent/persistent laryngeal cancer after primary radiotherapy (RT). STUDY DESIGN: : Retrospective chart review. METHODS: Charts of 51 consecutive patients who had salvage total or supracricoid laryngectomy with or without neck dissection for recurrent/persistent laryngeal squamous cell carcinoma after primary RT from 1988 to 2005 in our institution were reviewed. No patients received concomitant or neo-adjuvant chemotherapy. Thirty-four patients underwent SLS along with unilateral or bilateral neck dissection, whereas 17 patients underwent the SLS without neck dissection. Reports of preRT and preSLS staging of the primary tumor and the neck, recorded using the TNM system, were reviewed. Reports of the final histopathologic examination for the excised laryngeal cancer and cervical lymph nodes were reviewed. RESULTS: Thirty-four patients underwent SLS with unilateral or bilateral neck dissection. The preRT staging of the primary tumor for those 34 patients showed that 32 (94%) were staged T-1 (14) and T-2 (18), whereas the preSLS staging of the primary tumor for those 34 patients showed that 29 (85%) were staged T-3 and T-4. The postSLS final histopathologic examination of the excised lymph nodes in those 34 patients demonstrated that 30 (88%) did not have any evidence of nodal metastasis. On comparing patients with and without nodal metastasis (on their postSLS final histopathology), we found that the preSLS neck staging, based on computed tomographic (CT) scanning of the neck, was significantly associated with the negative/positive postSLS status of nodal metastasis (P = .006). Of 29 patients staged preSLS as N-0, 28 (97%) patients did not have nodal metastasis on their postSLS final pathology (negative predictive value = 97%, confidence interval, 82.2-99.9). PreRT neck staging, preRT and preSLS staging of the primary tumor, along with laryngeal subsite involvement (supraglottis, glottis, subglottis) did not significantly correlate with the status of neck metastasis on final postSLS histopathology (P = .68, 0.78, 0.49, and 0.42, respectively). None of the 34 patients had any neck tumor recurrence in the postSLS follow-up period (median, 3 yr). In addition, all 17 patients who underwent SLS without neck dissection were staged N-0 both before RT as well as preSLS, and none developed neck disease in the postSLS follow-up period (median, 2.5 yr). CONCLUSION: Management of the neck in patients undergoing salvage total or supracricoid laryngectomy for laryngeal cancer recurrence/persistence after primary RT should be based on the preSLS CT staging of the neck. Patients staged N-0 preSLS are not likely to harbor occult nodal metastasis and therefore may not require elective neck dissection.

High efficiency gene delivery into laryngeal muscle with bidirectional electroporation.

OBJECTIVE: The impact of polarity change on the efficiency of in vivo electroporative (EP) gene transfection was assessed in rat laryngeal muscle. STUDY DESIGN AND SETTING: High (HV) and low field voltage (LV) were combined with polarity changes to determine transfection in 5 different conditions: 1) without EP (EP[-]), 2) HV+LV (HL), 3) HV+LV followed by HV+LV with no change in polarity (HLHL unidirectional), 4) HV+LV followed by HV+LV with opposite polarity (HLHL bidirectional), 5) HV+LV followed by LV with opposite polarity (HLL bidirectional). RESULTS: HLL bidirectional sequence showed the best result with less interindividual variability and extended expression period. With the exception of repeated high voltage sequences, EP parameters were not likely to induce cell injury or inflammation. CONCLUSION: HLL bidirectional electroporative gene delivery produces high transfection rates with limited tissue trauma. SIGNIFICANCE: Bidirectional EP provides a safe and highly efficient method for therapeutic gene delivery into skeletal muscle.

The role of positron emission tomography and computed tomography fusion in the management of early-stage and advanced-stage primary head and neck squamous cell carcinoma.

OBJECTIVE: To evaluate the role of positron emission tomography and computed tomography (PET-CT) fusion in the management of early-stage and advanced-stage primary head and neck squamous cell cancer. DESIGN: Retrospective analysis, with a blinded evaluation of clinical data and formation of a treatment plan. SETTING: Single tertiary academic medical institution. Patients Thirty-six patients with previously untreated head and neck squamous cell carcinoma who underwent staging CT or magnetic resonance imaging of the neck prior to undergoing PET-CT as part of their initial diagnostic evaluation between July 2000 and January 2005. MAIN OUTCOME MEASURES: Confirmation or alteration of the treatment plan with the addition of the PET-CT information compared with traditional clinical and radiological data alone for early-stage and advanced-stage disease. When available, histopathological results were correlated with the PET-CT findings. RESULTS: Among the 36 patients, PET-CT provided additional information that confirmed the treatment plan in 25 patients (69%) and altered the treatment plan in 11 patients (31%). Six of 11 patients in the altered-treatment group had their tumors upstaged. Four of 8 patients with early-stage tumors had their treatment plan altered, compared with 7 of 28 patients with advanced-stage disease. Among 18 patients who underwent a surgical intervention for their primary tumor, PET-CT identified the primary tumor in all 18 patients and, based on histopathological findings, correctly staged the regional nodal disease in 9 of 16 patients who had their nodal disease addressed. CONCLUSION: The use of PET-CT is important in the initial treatment planning of early-stage and advanced-stage head and neck squamous cell carcinoma.

Laryngeal muscle surface receptors identified using random phage library.

OBJECTIVES: The ultimate goal of this study is to improve the efficiency of gene transfer in mammalian muscle by developing targeted adenoviral vectors. Altering the tropism of viral vectors to recognize tissue specific antigens is one method to achieve this goal. This approach requires identification of cell-surface receptors and the insertion of target peptide sequences into the adenoviral fiber protein. In this study, phage biopanning was performed on cultured rat skeletal and laryngeal muscle to identify cell-surface receptors. STUDY DESIGN: In vitro cell culture and in vivo animal model. METHODS: M-13 Phage biopanning was used for muscle cell-surface receptor analysis on cultured rat skeletal and laryngeal muscle. Nonbinding and binding phage to cultured skeletal and laryngeal muscle were screened for muscle specific surface peptides. In vivo studies were then performed using muscle specific phage. RESULTS: Skeletal muscle specific binding by the YASTNPM phage was observed by in vivo immunostaining. Phage titering demonstrated a 10(9)-fold increase in skeletal muscle binding compared with nontarget tissue. A peptide sequence (NPSQVKH) specific for laryngeal muscle yielded a 10(7)-fold increase in laryngeal muscle phage titer compared with nontarget tissue. CONCLUSIONS: These results identify muscle cell-surface receptors that may be used as potential targets for genetic modification of adenovirus tropism. Moreover, phage specificity for skeletal and laryngeal muscle indicates specific muscle groups may be targeted.

Evaluation of several two-dimensional gel electrophoresis techniques in cardiac proteomics.

Two-dimensional gel electrophoresis (2-DE) is currently the best method for separating complex mixtures of proteins, and its use is gradually becoming more common in cardiac proteome analysis. A number of variations in basic 2-DE have emerged, but their usefulness in analyzing cardiac tissue has not been evaluated. The purpose of the present study was to systematically evaluate the capabilities and limitations of several 2-DE techniques for separating proteins from rat heart tissue. Immobilized pH gradient strips of various pH ranges, parameters of protein loading and staining, subcellular fractionation, and detection of phosphorylated proteins were studied. The results provide guidance for proteome analysis of cardiac and other tissues in terms of selection of the isoelectric point separating window for cardiac proteins, accurate quantitation of cardiac protein abundance, stabilization of technical variation, reduction of sample complexity, enrichment of low-abundant proteins, and detection of phosphorylated proteins.

An electrophysiologic model for functional assessment of effects of neurotrophic factors on facial nerve reinnervation.

OBJECTIVES: To establish a sound objective model for assessing the effects of neurotrophic factors on facial nerve function after injury and to compare the effects of brain-derived neurotrophic factor (BDNF) with its neutralizing antibody on facial nerve function after injury. DESIGN: Prospective electrophysiologic analysis of recovery of function 4 weeks after axotomy involving facial nerve transection and primary end-to-end reanastomosis in adult rats and blind comparison with randomized intramuscular injection of either BDNF, monoclonal antibody to BDNF in neutralizing concentration, or control solution. RESULTS: There were no statistically significant differences between groups in latencies, duration, amplitude, area, or conduction velocity before axotomy, and recorded conduction velocities were consistent with previously reported values, which suggests that the recordings were reliable and reproducible. After transection, there was a mean increase in latency 1 and decreases in latency 2, integrated average area, muscle action potential duration, amplitude, and conduction velocity for all 3 groups. When the groups were compared after transection, the anti-BDNF group showed a significant decrease in conduction velocity and muscle action potential duration (Kruskal-Wallis P = .01 and P = .008, respectively) compared with the other groups. There were no statistically significant differences in latencies, amplitude, or area among the groups. CONCLUSIONS: We have established an electrophysiologic model for objective assessment of facial nerve function in the rat. Future studies should combine functional electrophysiologic assessment and histologic examination to provide a more robust model for studying the effects of neurotrophic factors on facial nerve reinnervation and synkinesis.