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Dive into the research topics where Ken Kazahaya is active.

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Featured researches published by Ken Kazahaya.


Journal of Clinical Investigation | 1998

CD8 positive T cells influence antigen-specific immune responses through the expression of chemokines.

Jong J. Kim; Liesl K. Nottingham; Jeong I. Sin; Anthony Tsai; Lake Morrison; Jim Oh; Kesen Dang; Yin Hu; Ken Kazahaya; Mosi Bennett; Tzvete Dentchev; Darren M. Wilson; Ara A. Chalian; Jean D. Boyer; Michael G. Agadjanyan; David B. Weiner

The potential roles of CD8(+) T-cell-induced chemokines in the expansion of immune responses were examined using DNA immunogen constructs as model antigens. We coimmunized cDNA expression cassettes encoding the alpha-chemokines IL-8 and SDF-1alpha and the beta-chemokines MIP-1alpha, RANTES, and MCP-1 along with DNA immunogens and analyzed the resulting antigen-specific immune responses. In a manner more similar to the traditional immune modulatory role of CD4(+) T cells via the expression of Th1 or Th2 cytokines, CD8(+) T cells appeared to play an important role in immune expansion and effector function by producing chemokines. For instance, IL-8 was a strong inducer of CD4(+) T cells, indicated by strong T helper proliferative responses as well as an enhancement of antibody responses. MIP-1alpha had a dramatic effect on antibody responses and modulated the shift of immune responses to a Th2-type response. RANTES coimmunization enhanced the levels of antigen-specific Th1 and cytotoxic T lymphocyte (CTL) responses. Among the chemokines examined, MCP-1 was the most potent activator of CD8(+) CTL activity. The enhanced CTL results are supported by the increased expression of Th1 cytokines IFN-gamma and TNF-alpha and the reduction of IgG1/IgG2a ratio. Our results support that CD8(+) T cells may expand both humoral and cellular responses in vivo through the elaboration of specific chemokines at the peripheral site of infection during the effector stage of the immune response.


The American Journal of Surgical Pathology | 2007

Hamartomatous tongue lesions in children

Portia A. Kreiger; Linda M. Ernst; Lisa Elden; Ken Kazahaya; Faizan Alawi; Pierre Russo

The incidence and spectrum of tongue lesions in children, in particular tongue hamartomas, is relatively unknown. We report a retrospective review of all tongue lesions seen at a major tertiary care childrens hospital over an 18-year period with an emphasis on describing tongue hamartomas. A total of 135 tongue lesions were identified. Vascular/lymphatic lesions (36/135) were the most common followed by mucus extravasation phenomenon (22/135). Interestingly, hamartomatous lesions (18/135) were the third most common lesion category identified. Lingual hamartomas were predominantly submucosal in location and were classified histologically by tissue composition as follows: neurovascular (2/18), smooth muscle predominant (5/18), fat predominant (1/18), and smooth muscle and fat containing (10/18). All 5 smooth muscle predominant hamartomas also contained vasculature, and 1 case additionally contained salivary gland tissue. The single fat predominant hamartoma additionally contained vessels and salivary gland. The final 10 hamartomas contained varying amounts of both smooth muscle and fat, and also admixed combinations of vessels, nerves, and salivary glands. Two of these 10 cases additionally contained foci of choristomatous elements, including cutaneous adnexal structures and cartilage. Most patients with hamartomatous lesions were young, 2 years or less. Eight cases were congenital in origin. Females outnumbered males by 2:1. The majority of lesions (16/18) were dorsal in location, and 4 patients had a syndromic association, all oral-facial-digital syndrome.


Laryngoscope | 2005

Trends in the management of pediatric chronic sinusitis: survey of the American Society of Pediatric Otolaryngology.

Steven E. Sobol; Daniel S. Samadi; Ken Kazahaya; Lawrence W. C. Tom

Background: The management of chronic sinusitis (CS) in children has yet to be fully elucidated. The objective of this study is to assess practice trends within the pediatric otolaryngology community for the management of children with CS.


Otolaryngology-Head and Neck Surgery | 2003

Revisiting Outpatient Tonsillectomy in Young Children

Adam T. Ross; Ken Kazahaya; Lawrence W. C. Tom

OBJECTIVE: Postoperative same-day discharge is safe for most children undergoing tonsillectomy. However, young children with upper airway obstruction have a higher risk of postoperative complications. We review our tonsillectomy experience in children under 36 months to evaluate the safety of outpatient tonsillectomy in this population. STUDY DESIGN AND SETTING: We conducted a retrospective study of all children under 36 months who underwent tonsillectomy during a recent 2-year period at The Childrens Hospital of Philadelphia. RESULTS: The indication for tonsillectomy in 96% of 421 children was upper airway obstruction. Eighteen percent required postoperative treatment to prevent respiratory compromise; 56% of these patients had no associated medical comorbidity. Patients younger than 24 months and those with medical comorbidities were more likely to require intervention. CONCLUSION AND SIGNIFICANCE: It is not possible to preoperatively anticipate which children will have postsurgical complications. We recommend planning an overnight admission for children younger than 36 months undergoing tonsillectomy.


Otology & Neurotology | 2004

Endolymphatic sac tumor in a 4-year-old boy.

Michael E. Kupferman; Douglas C. Bigelow; David F. Carpentieri; Larissa T. Bilaniuk; Ken Kazahaya

Introduction: Endolymphatic sac tumors (ELST) are rare, low-grade, locally aggressive papillary neoplasms. We present a case of a 4-year-old boy with an ELST, the youngest described in the literature. Case: A boy presented with a right-sided serous otitis media and sudden-onset right facial nerve palsy. An audiogram revealed right-sided profound sensorineural hearing loss. Radiographic imaging demonstrated a 3-cm expansile lytic lesion along the posterior face of the petrous bone. Intervention/Results: The patient initially underwent a right transmastoid–infralabyrinthine biopsy. Pathologic examination revealed a papillary lesion suspicious for an ELST. Subsequently, a transtemporal–transcochlear approach with intra-and extradural resection of the tumor was performed. The facial nerve was dissected and transposed anteriorly and preserved. Histopathologic and immunohistochemical studies confirmed the ELST. At his 6-month follow up, there is no evidence of recurrence and the facial nerve function has returned to Grade II palsy. Conclusion: ELST are rare tumors of the temporal bone. This is the youngest case of ELST reported. Presentation, evaluation, and management of ELST is discussed.


The Journal of Comparative Neurology | 1998

Morphometric changes in the chick nucleus magnocellularis following acoustic overstimulation.

James C. Saunders; Henry J. Adler; Yale E. Cohen; Sean Smullen; Ken Kazahaya

The present investigation considered the effects of cochlear damage caused by exposure to intense sound on the nucleus magnocellularis of the chick. Neonatal chicks exposed to intense sound were separated into four groups with post‐exposure recovery durations of 0, 15, 27, and 43 days. Four age‐matched, non‐exposed control groups were also formed. At each recovery interval, the control and exposed birds were sacrificed and their brains prepared for paraffin embedding. The brain stem region containing the nucleus magnocellularis (NM) was serially sectioned in the coronal plane. All sections containing NM cells were identified and then coded in terms of their percentile distance from the most caudolateral section. Sections along the nucleus at the 15th, 30th, 50th, 65th, 80th, and 95th percentile positions were selected for evaluation, and the cross‐sectional areas of individual NM cells in these sections were then measured. Cell areas were corrected for the bias introduced by eccentricity of the nucleus. The number of NM cells per 1,000 μm2 was also calculated at the 50th and 65th percentile positions. These procedures were repeated for the age‐matched, non‐exposed control animals.


Annals of Otology, Rhinology, and Laryngology | 2004

Cellular Neurothekeoma of the Maxilla

Noam A. Cohen; Bruce R. Pawel; Daniel S. Samadi; Ken Kazahaya

Neurothekeomas are uncommon benign soft tissue tumors of nerve sheath origin. They occur predominately in the head and neck or upper trunk of children and young adults. A 15-month-old boy presented with an enlarging mass of the right maxilla. Radiologic imaging demonstrated an expansile lesion of the nasomalar region. An incisional biopsy resulted in the diagnosis of neurothekeoma. This lesion should be considered as part of the differential diagnosis of pediatric soft tissue head and neck masses. We discuss the presentation, evaluation, and treatment of these rare benign lesions.


Magnetic Resonance Imaging Clinics of North America | 2012

Magnetic Resonance Imaging of the Pediatric Neck : An Overview

Karuna Shekdar; David M. Mirsky; Ken Kazahaya; Larissa T. Bilaniuk

Evaluation of neck lesions in the pediatric population can be a diagnostic challenge, for which magnetic resonance (MR) imaging is extremely valuable. This article provides an overview of the value and utility of MR imaging in the evaluation of pediatric neck lesions, addressing what the referring clinician requires from the radiologist. Concise descriptions and illustrations of MR imaging findings of commonly encountered pathologic entities in the pediatric neck, including abnormalities of the branchial apparatus, thyroglossal duct anomalies, and neoplastic processes, are given. An approach to establishing a differential diagnosis is provided, and critical points of information are summarized.


International Journal of Pediatric Otorhinolaryngology | 2011

Management of isolated sphenoid sinus disease in children: a surgical perspective.

Lisa Elden; Megan Reinders; Ken Kazahaya; Lawrence W. C. Tom

OBJECTIVE To determine the spectrum of diseases and optimal timing of surgical drainage for the opacified sphenoid sinus in children. METHODS Ten year retrospective chart review of children with isolated sphenoid sinus disease. RESULTS Fourteen patients (mean age 11 ± 2.8 years, range 6.5-15.1 years) were diagnosed with isolated sphenoid sinus disease. Five patients had acute, severe bacterial sphenoiditis, four had sphenoid mucoceles, three had suspected tumors involving the sphenoid bone, clivus or sella, and two were identified incidentally when imaging studies were obtained for unrelated reasons. Headache was the most common symptom. Cranial nerve or other intracranial complications were present in all of those referred because of infection, but in none of the other patients. Computed tomography (CT) revealed the presence of disease in all cases. Compared with CT, magnetic tomography (MRI) was more helpful in identifying the extent of disease spread in two patients with acute bacterial sphenoiditis and in three patients with suspected tumors. All improved with surgical drainage or biopsy of the suspected tumor. In two cases, children were treated conservatively with antibiotics and the primary symptoms resolved. CONCLUSIONS Isolated sphenoid sinus disease is rare in children. Those with clinically significant disease presented with progressive, severe headaches and minimal sinus symptoms. MRI studies were important to identify the source of headache and evolving complications in several of these patients.


Otolaryngology-Head and Neck Surgery | 2013

Endolaryngeal Hookwire Electrodes for Intraoperative Recurrent Laryngeal Nerve Monitoring during Pediatric Thyroid Surgery

Jeffrey Cheng; Ken Kazahaya

Objective To describe the senior author’s surgical technique and discuss his experience with endolaryngeal hookwire electrodes for intraoperative, recurrent laryngeal nerve monitoring during pediatric thyroid surgery. Study Design Consecutive case series. Setting Tertiary-care, academic, children’s hospital. Subjects and Methods A consecutive case series review of pediatric patients (age <16 years) who underwent thyroid surgery with intraoperative, endolaryngeal hookwire recurrent laryngeal nerve monitoring. Nerve injury was defined as vocal cord dysfunction present >12 months postoperatively. Results Seventeen patients were identified. There were 5 males and 12 females, and the average age was 11.7 years (range, 4-15 years). Nineteen procedures were performed—4 hemithyroidectomies, 2 completion thyroidectomies, and 13 total thyroidectomies—with 32 nerves at risk. One patient had a recurrent laryngeal nerve injury with a nerve paresis that persisted longer than 12 months postoperatively, making our recurrent laryngeal nerve injury rate 3.1% (1/32). Fortunately, the nerve eventually recovered to normal function. Conclusion Thyroid nodules and surgery in children consist of higher rates of malignancy and potentially higher risks for recurrent laryngeal nerve complications. Our injury rate was 3.1%. Intraoperative recurrent laryngeal nerve monitoring with endolaryngeal hookwire electrodes in pediatric thyroid surgery may be helpful in nerve identification and is very sensitive. This technique can be used in situations in which endotracheal tubes with surface electrodes cannot be accommodated by the smaller size of the pediatric airway.

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Andrew J. Bauer

Children's Hospital of Philadelphia

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Brian Dunham

Children's Hospital of Philadelphia

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Jeffrey Cheng

Massachusetts Eye and Ear Infirmary

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Luv Javia

Children's Hospital of Philadelphia

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N. Scott Adzick

Children's Hospital of Philadelphia

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Sogol Mostoufi-Moab

Children's Hospital of Philadelphia

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Daniel S. Samadi

University of Pennsylvania

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Ara A. Chalian

University of Pennsylvania

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