Faculty Bibliography

As advanced signal processing algorithms have been proposed to enhance hearing protective device (HPD) performance, it is important to determine how directional microphones might affect the localization ability of users and whether they might cause safety hazards. The effect of in-the-ear microphone directivity was assessed by measuring sound source identification of speech in the horizontal plane. Recordings of speech in quiet and in noise were made with Knowles Electronic Manikin for Acoustic Research wearing bilateral in-the-ear hearing aids with microphones having adjustable directivity (omnidirectional, cardioid, hypercardioid, supercardioid). Signals were generated from 16 locations in a circular array. Sound direction identification performance of eight normal hearing listeners and eight hearing-impaired listeners revealed that directional microphones did not degrade localization performance and actually reduced the front-back and lateral localization errors made when listening through omnidirectional microphones. The summed rms speech level for the signals entering the two ears appear to serve as a cue for making front-back discriminations when using directional microphones in the experimental setting. The results of this study show that the use of matched directional microphones when worn bilaterally do not have a negative effect on the ability to localize speech in the horizontal plane and may thus be useful in HPD design

Objective: To examine speech perception outcomes and determine the impact of length of deafness and time between implants on performance in the sequentially bilateral implanted population. STUDY DESIGN: Retrospective review. SETTING: Tertiary academic referral center. PATIENTS: Forty-three children (age, <18 yr) and 22 adults underwent sequential bilateral implantation with at least 6 months between surgeries. The mean age at the time of the second implant in children was 7.83 years, and mean time between implants was 5.16 years. Five children received the first side implant (C1) below 12 months of age; 16, at 12 to 23 months; 9, between the ages of 24 and 35 months; and 11, at 36 to 59 months; 2 were implanted above the age of 5 years. In adults, mean age at second implant was 46.6 years, and mean time between implants was 5.6 years. INTERVENTION: Sequential implantation with 6 months or more between implantations. MAIN OUTCOME MEASURES: Speech perception tests were performed preoperatively before the second implantation and at 3 months postoperatively. RESULTS: Results revealed significant improvement in the second implanted ear and in the bilateral condition, despite time between implantations or length of deafness; however, age of first-side implantation was a contributing factor to second ear outcome in the pediatric population. CONCLUSION: Sequential bilateral implantation leads to significantly better speech understanding. On average, patients improved, despite length of deafness, time between implants, or age at implantation

Spike timing-dependent synaptic plasticity (STDP) plays an important role in neural development and information processing in the brain; however, the mechanism by which spike timing information is encoded into STDP remains unclear. Here, we show that a novel allosteric kinetics of NMDA receptors (NMDARs) is required for STDP. We developed a detailed biophysical model of STDP and found that the model required spike timing-dependent distinct suppression of NMDARs by Ca(2+)-calmodulin. This led us to predict an allosteric kinetics of NMDARs: a slow and rapid suppression of NMDARs by Ca(2+)-calmodulin with prespiking --> postspiking and postspiking --> prespiking, respectively. We found that the allosteric kinetics, but not the conventional kinetics, is consistent with specific features of amplitudes and peak time of NMDAR-mediated EPSPs in experiments. We found that the allosteric kinetics of NMDARs was also valid for synaptic plasticity induced by more complex spike trains in layer II/III of visual cortex. We extracted an essential synaptic learning rule by reduction of the allosteric STDP model and found that spike timing-dependent bidirectional role of postspiking in synaptic modification, which depends on the allosteric kinetics, is the essential principle in STDP. Thus, we propose a simple hypothesis of the allosteric kinetics of NMDARs that can coherently explain critical features of spike timing-dependent NMDAR-mediated EPSPs and synaptic plasticity

We investigated the cannabinoid receptor (CBr) agonists Win55,212-2 (non-selective) and AM1241 (CBr2 selective) and the peripheral receptor (CBr1) in carcinoma-induced pain using a mouse model. Tumors were induced in the hind paw of female mice by local injection of a human oral squamous cell carcinoma (SCC). Significant pain, as indicated by reduction in withdrawal thresholds in response to mechanical stimulation, began at 4 days after SCC inoculation and lasted to 18 days. Local administration of Win55,212-2 (10 mg/kg) and AM1241 (10 mg/kg) significantly elevated withdrawal thresholds, indicating an antinociceptive effect. Ipsilateral expression of CBr1 protein in L5 DRG was significantly upregulated compared to ipsilateral L4 DRG and in normal tissue. These findings support the suggestion that cannabinoids are capable of producing antinociception in carcinoma-induced pain

OBJECTIVE: To characterize the background and outcomes of tonsillectomy malpractice claims. METHODS: Review of 69 New York State insurance claims (Part I) and 87 national court trials (Part II) alleging injury after tonsillectomy. RESULTS: Part I. New York State insurance cases were most commonly discontinued (44%) or settled (42%) before trial. Compensations with a settlement or verdict were made in 48 percent of cases. Part II. Death or major injury occurred in 52 percent of insurance cases, with a mean award of $403,656 being made to plaintiffs. Of cases reaching trial, 60 percent of plaintiffs were compensated. Awards against anesthesiologists were more frequent and higher than against surgeons ($5 million vs $839,650). Death or major injury occurred in 52 percent of court cases, resulting in mean indemnity of $3.8 million. Most cases of death or major injury were attributable to airway complications. CONCLUSIONS: Approximately half of both New York state claims and court cases involved death or devastating morbidity, mostly related to airway complications, resulting in large awards. Tonsillectomy is a source of uncommon but potentially high-dollar-value litigation exposure to the surgeon, often attributable to non-surgical complications

PURPOSE: Resecting oral squamous cell carcinoma (SCC) with an appropriate margin of uninvolved tissue is critical in preventing local recurrence and making the decision regarding postoperative radiation therapy. This task can be difficult due to the discrepancy between margins measured intraoperatively and those measured microscopically by the pathologist after specimen processing. The goal of this study is to quantify and compare the amount of margin discrepancy observed based on tumor location and staging. MATERIALS AND METHODS: Forty-one patients who underwent resective surgery with curative intent for primary oral SCC were included in this study. All patients underwent resection of the tumor with a measured 1 cm margin by one attending surgeon. Specimens were then submitted for processing and reviewing and histopathologic margins were measured. The closest histopathologic margin was compared with the in situ margin (1 cm) to determine percentage discrepancy. Percent discrepancies were grouped by locations (buccal mucosa, mandibular alveolar ridge, and retromolar trigone in group 1; maxillary alveolar ridge and palate in group 2; and oral tongue in group 3) and analyzed. Percent discrepancies grouped by stages T1/T2 or T3/T4 were compared. RESULTS: The mean discrepancy for all patients was a statistically significant 59.02% (P < .0001). The mean discrepancy was 71.90% for group 1, 53.33% for group 2, and 42.14% for group 3 (P = .0133). The mean discrepancy in T1/T2 tumors was 51.48% and in T3/T4 tumors was 75.00% (P = .0264). CONCLUSIONS: Oral SCC margin discrepancies after resection and specimen processing are highly significant. Tumors located in the buccal mucosa, retromolar trigone, and mandibular alveolar ridge show significantly greater discrepancies than tumors of the maxilla or oral tongue. Late stage tumors also show significantly greater margin discrepancies. These findings suggest that it might be prudent to consider oral site and staging when outlining margins to ensure adequacy of resection

OBJECTIVES: To determine the incidence of methicillin-resistant Staphylococcus aureus (MRSA)-positive surgical site infections after face-lift surgery and to discuss the screening, prevention, and treatment of such infections. METHODS: The patient charts of 780 patients who underwent a deep-plane rhytidectomy between 2001 and 2007 were reviewed for postoperative wound infections. Culture results and sensitivities were recorded. To our knowledge, this is the first study that documents MRSA-positive surgical site infections after face-lift surgery. RESULTS: Five of 780 patients (0.6%) who underwent face-lift surgery by the senior surgeon had postoperative surgical site infections. Four of the 5 patients had cultures that were positive for MRSA. Two of these patients (0.3%) required hospitalization and had collections that had to be opened or drained and developed wound breakdown. Both patients eventually responded to wound care along with intravenous and then oral antibiotic therapy. The other 2 MRSA-infected patients responded to oral antibiotic therapy and local wound care alone. The 2 complicated infections occurred on postoperative days 5 and 8. These 2 patients were the only ones among the 5 patients with positive cultures who had known recent contact with another physician or a hospital. All infections occurred in the year 2006, with 3 patients experiencing infection in the last 4 months of the year. Herein, we describe the incidence and sequelae of MRSA infections and colonization. The 2 major different subsets of MRSA are community-acquired MRSA and health care-associated MRSA. Surgical site infections that are positive for MRSA blur this division, which affects many aspects of the course of disease and treatment. We also discuss strategies for screening, preventing, and treating MRSA surgical site infections. CONCLUSIONS: Methicillin-resistant S aureus-positive surgical site infection is an increasingly problematic issue in all surgical fields. In the future, MRSA-positive infections will be more prevalent and will require well-developed screening, prevention, and treatment strategies

OBJECTIVES: Kaposi sarcoma (KS) is a vascular tumor that can affect the mucosa of the upper aerodigestive tract. Although KS is the most common malignancy in patients with acquired immunodeficiency syndrome, it is rare in immunocompetent persons. We describe an unusual presentation of KS in 2 related individuals and describe our attempts to determine whether oropharyngeal KS is associated with human herpesvirus 8 (HHV-8). METHODS: All relevant clinical and surgical information, including information on tumor histopathologic and human immunodeficiency virus (HIV) serologic tests, was abstracted from the patient charts and electronic databases. HHV-8 immunohistochemistry was performed on paraffin-fixed specimens. RESULTS: Both patient 1 and patient 2 (the nephew of patient 1) were referred for workup of a tonsillar mass that was pathologically confirmed to be KS. In each case, HIV serologic testing was negative, and a screening immunologic workup, including a quantitative natural killer cell count, a B- and T-lymphocyte count, and immunoglobulin analysis, also yielded findings that were within normal limits. Immunohistochemistry performed on 1 pathological specimen showed positive staining for the presence of HHV-8, the etiologic agent of KS. CONCLUSIONS: The presence of oropharyngeal KS in 2 related HIV-negative individuals supports a role for genetic factors in susceptibility to KS, a common exposure to an infectious agent such as HHV-8, or both. Whereas most KS cases in industrialized countries are associated with immunodeficiency, clinical and laboratory data do not suggest that either of the patients described in this report are immunodeficient. Their susceptibility to KS may be secondary to a subtle inherited defect in host resistance to HHV-8, or another unknown factor

OBJECTIVE: To determine the rate of hematoma formation in drainless deep-plane rhytidectomy and compare it with the rate using the same technique with the use of fibrin glue. METHODS: This is a retrospective review of 605 patients (78 male and 527 female) who, over a 6-year period, underwent deep-plane face-lift surgery (n = 544) or lateral superficial musculoaponeurotic system (SMAS)ectomy (n = 61) by the senior author (S.S.R.) without the use of surgical drains. One hundred forty-six consecutive patients underwent rhytidectomy without fibrin tissue glue, and the following 459 consecutive patients were sprayed with fibrin glue under the flap prior to flap closure. Pressure dressings were used on all patients for 24 hours. RESULTS: None of the patients in either group had major or expanding hematomas requiring operative intervention. In the group of patients treated without fibrin glue (n = 146), there were 5 minor, nonexpanding hematomas, all managed by needle aspiration. This is a minor hematoma rate of 3.4%. In the fibrin glue group (n = 459), there were 2 hematomas, for a rate of 0.4%. Using a Fisher exact test, we found a statistically significant decrease in the hematoma rate from 3.4% to 0.4% (P = .01). Male patients had a higher hematoma rate than female patients, and only men had significantly fewer hematomas when fibrin glue was applied (P = .01). All 7 hematomas were recognized in the first 24 hours after surgery. Of the 7 patients with hematomas, 2 (29%) had emesis in the recovery room despite medication. CONCLUSIONS: The use of fibrin glue demonstrates a significant decrease in the rate of hematoma formation. Fibrin glue may benefit male more than female patients. If meticulous hemostasis and pressure dressings are used, drains are not necessary. The prevention and prompt treatment of postoperative nausea may also help prevent hematoma formation

Adhesion of leukemic cells to vascular cells may confer resistance to chemotherapeutic agents. We hypothesized that disruption of leukemic cell cytoskeletal stability and interference with vascular cell interactions would promote leukemic cell death. We demonstrate that low and nontoxic doses of microtubule-destabilizing agent combretastatin-A4-phosphate (CA4P) inhibit leukemic cell proliferation in vitro and induce mitotic arrest and cell death. Treatment of acute myeloid leukemias (AMLs) with CA4P leads to disruption of mitochondrial membrane potential, release of proapoptotic mitochondrial membrane proteins, and DNA fragmentation, resulting in cell death in part through a caspase-dependent manner. Furthermore, CA4P increases intracellular reactive oxygen species (ROS), and antioxidant treatment imparts partial protection from cell death, suggesting that ROS accumulation contributes to CA4P-induced cytotoxicity in AML. In vivo, CA4P inhibited proliferation and circulation of leukemic cells and diminished the extent of perivascular leukemic infiltrates, prolonging survival of mice that underwent xenotransplantation without inducing hematologic toxicity. CA4P decreases the interaction of leukemic cells with neovessels by down-regulating the expression of the adhesion molecule VCAM-1 thereby augmenting leukemic cell death. These data suggest that CA4P targets both circulating and vascular-adherent leukemic cells through mitochondrial damage and down-regulation of VCAM-1 without incurring hematologic toxicities. As such, CA4P provides for an effective means to treat refractory organ-infiltrating leukemias