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Biomedical subjects

F G Ondrey

Publications and source records attributed to F G Ondrey.

At least 19 recordsLinked to original sources
PubMed2001

Recommendations for cancer prevention trials using potentially ototoxic test agents.

PURPOSE: Preventive oncology applies pharmacologic agents to reverse, retard, or halt progression of neoplastic cells to invasive malignancy, a process that may require administration of agents over long periods of time. Although ototoxicity may be a tolerable side effect of anticancer or antimicrobial therapy, even modest ototoxicity may not be acceptable in agents developed for preventive oncology that are routinely administered to subjects who neither are, nor necessarily will become, clinically ill. MATERIALS AND METHODS: Age-related shifts in hearing may occur over the course of longterm or open-ended therapy; consequently, age-adjusted norms enable researchers to better distinguish hearing loss caused by drugs from that caused by aging. Norms for hearing sensitivity are derived from the Baltimore Longitudinal Study of Aging and are the basis for the proposed audiologic monitoring recommendations. RESULTS: Audiologic monitoring recommendations are presented that standardize patient selection, adverse event reporting, posttreatment follow-up, and audiologic testing for potentially ototoxic investigational agents. CONCLUSION: These recommendations are applicable to trials of investigational agents as well as various classes of drugs used in routine clinical care.

Adult↗
PubMed2001

Concurrent paclitaxel and radiation in the treatment of locally advanced head and neck cancer.

PURPOSE: To determine the feasibility of an organ preservation regimen consisting of infusional paclitaxel administered concurrently with radiotherapy to patients with locally advanced head and neck squamous cell carcinoma (HNSCC). PATIENTS AND METHODS: Thirty-three previously untreated patients with stage III or IV tumors were enrolled onto the study. Paclitaxel was administered as a 120-hour continuous infusion every 3 weeks during the course of radiation therapy. Sixteen patients received a paclitaxel dose of 105 mg/m(2), and 17 patients received 120 mg/m(2). Radiation was delivered in a standard format at 1.8 Gy/d to a total dose of 70.2 to 72 Gy. RESULTS: Three months after therapy, a 76% complete response (CR) at the primary site and a 70% overall CR was achieved. At 36 months, locoregional control was 55.7%, overall survival was 57.8%, and disease-free survival was 51.1%. The median survival duration for all 33 patients was greater than 50 months at the time of this report. Local toxicities including mucositis, dysphagia, and skin reactions were severe but tolerable. All patients retained functional speech, and all but four patients were swallowing food 3 months after treatment. Steady-state plasma concentrations for paclitaxel were not achieved during a 120-hour infusion, suggesting a nonlinear process. Tumor volume quantified by pretreatment computerized tomography imaging was associated with likelihood of response and survival. CONCLUSION: Paclitaxel administered as a 120-hour continuous infusion in combination with radiotherapy is a feasible and promising treatment for patients with advanced HNSCC.

Adult↗
PubMed2001

Auditory dysfunction in Stickler syndrome.

OBJECTIVES: To characterize the natural history and possible mechanisms of hearing loss in Stickler syndrome (OMIM 108300; or hereditary progressive arthro-ophthalmopathy) and to determine if the auditory phenotype is a useful discriminating feature for the differential diagnosis of this group of disorders. DESIGN: Multifamily study. SETTING: Outpatient audiology and otolaryngology clinics at the Warren Grant Magnuson Clinical Center of the National Institutes of Health, Rockville, Md. SUBJECTS: Forty-six affected individuals from 29 different families segregating Stickler syndrome. INTERVENTIONS: Clinical audiologic and otolaryngological examinations were performed on all individuals, including pure-tone audiometry, speech audiometry, and middle ear immittance testing. Otoacoustic emissions, auditory brainstem response, infrared video electronystagmography, and temporal bone computed tomography were performed on a subset of participants. RESULTS: The hearing loss was most often sensorineural in adults, and approximately 28 (60%) of the 46 adult patients had 2 or more thresholds greater than the corresponding 95th percentile values for an age-matched, otologically normal population. The hearing loss most often affected high frequencies (4000-8000 Hz) and was generally no more progressive than that due to age-related hearing loss. Type A(D) tympanograms (classification using the Jerger model), indicating hypermobile middle ear systems, were observed in 21 (46%) of the 46 affected individuals. Computed tomography of the temporal bones revealed no inner ear malformations in 19 affected individuals. CONCLUSIONS: The hypermobile middle ear systems observed in ears with normal-appearing tympanic membranes represent a novel finding for Stickler syndrome and are likely to be a useful diagnostic feature for this disorder. The overall sensorineural hearing loss in type I Stickler syndrome is typically mild and not significantly progressive. It is less severe than that reported for types II and III Stickler syndrome linked to COL11A2 (OMIM 120290) and COL11A1 (OMIM 120280) mutations, respectively, or the closely related Marshall syndrome. This difference will be a useful discriminatory feature in the differential diagnosis of this group of disorders.

Adolescent↗
PubMed2001

Prospective comparison of panoramic tomography (zonography) and helical computed tomography in the diagnosis and operative management of mandibular fractures.

This prospective study compared the sensitivity of panoramic tomography (zonography) and helical computed tomography (CT) in diagnosing 73 mandibular fractures in 42 consecutive patients and correlated the results with known surgical findings. The purpose of the study was to determine the optimal radiologic examination for the diagnosis and operative management of mandibular fractures. The attending surgeons' interpretations of panoramic tomograms and helical CT images in the axial plane were compared with the patients' known surgical findings. A series of questions assessed the relative contribution of these two radiologic examinations in formulating an optimal operative plan for each patient. In the 42 patients studied, the sensitivity of helical CT was 100 percent in diagnosing mandibular fractures; this compared with 86 percent (36 of 42) for panoramic tomography, in which significantly more fractures were missed (p = 0.0412). In the six patients with fractures not visualized, the operative management was altered because of the new fracture visualized on helical CT. Of the seven missed fractures, six were in the posterior portion of the mandible. Comparing fracture detection by region, seven fractures found on helical CT were not visualized on panoramic tomography. Helical CT improved the understanding of the nature of mandibular fractures by providing additional information regarding fracture displacement and comminution and by locating injuries missed using panoramic tomography. This study suggests that helical CT alone may be more diagnostic than panoramic tomography alone in evaluating mandibular fractures. Helical CT sufficiently demonstrated details of fractures in 41 of 42 patients; in one patient, the nature of a dental root fracture was better delineated by panoramic tomography.

Humans↗
PubMed2000

Cisplatin and radiation sensitivity in human head and neck squamous carcinomas are independently modulated by glutathione and transcription factor NF-kappaB.

BACKGROUND: Response to neoadjuvant cisplatin-based chemotherapy has been used to predict overall response to chemoradiation therapy and to select patients with head and neck squamous cell carcinoma (HNSCC) for organ preservation therapy in NCI and VA cooperative group trials. However, different molecular determinants have been reported to contribute to sensitivity of cells to cisplatin and radiation, including glutathione (GSH), and activation of nuclear factor-kappaB (NF-kappaB), a transcription factor that regulates cytoprotective genes. We have reported that NF-kappaB is constitutively activated in HNSCC, but the relationship of NF-kappaB to GSH and to cisplatin and radiation sensitivity in HNSCC is unknown. METHODS: We examined human HNSCC lines to define the relationship of cisplatin and radiation sensitivity to intracellular GSH and NF-kappaB and determined whether HNSCC could be sensitized to these modalities by lowering the concentration of glutathione with L-buthionine sulfoximine or inhibiting activation of NF-kappaB by expression of a degradation-resistant mutant inhibitor-kappaBalpha. RESULTS: Cisplatin resistance did not predict radiation resistance in three HNSCC cell lines, UM-SCC-9, 11B, and, 38. Resistance to cisplatin correlated with intracellular GSH, and depletion of GSH by treatment with L-BSO sensitized UM-SCC-9 cells to cisplatin but not radiation. Conversely, radiation resistance was correlated with activation of NF-kappaB. Expression of a mutant Inhibitor-kappaB after gene transfer inhibited NF-kappaB and sensitized UM-SCC-9 cells to radiation but not cisplatin. CONCLUSIONS: GSH and transcription factor NF-alphaB can contribute independently to cisplatin and radiation sensitivity of human HNSCC. These results highlight the need to define molecular determinants of chemotherapy and radiation sensitivity for use in the selection of patients and as novel targets for therapy in future chemoradiation therapy trials for organ preservation in patients with HNSCC.

Base Sequence↗
PubMed2000

Inhibition of transcription factor nuclear factor-kappaB by a mutant inhibitor-kappaBalpha attenuates resistance of human head and neck squamous cell carcinoma to TNF-alpha caspase-mediated cell death.

Tumour necrosis factor-alpha (TNF-alpha) is a cytokine that can induce cell death of different cancers via a cellular cascade of proteases, the caspases. However, TNF-alpha has been detected in tumour and serum of patients with head and neck squamous cell carcinoma (HNSCC), and tumour cell lines derived from this environment often exhibit resistance to TNF-alpha-induced cell death. Cell death mediated by TNF-alpha and caspases may be inhibited by cytoprotective genes regulated by transcription factor nuclear factor-kappaB (NF-kappaB). We recently showed that NF-kappaB is constitutively activated in HNSCC, and that inhibition of NF-kappaB by expression of a nondegradable mutant inhibitor of NF-kappaB, IkappaBalphaM, markedly decreased survival and growth of HNSCC cells in vivo. In the present study, we examined the TNF-alpha sensitivity and response of HNSCC with constitutively active NF-kappaB, and of HNSCC cells in which NF-kappaB is inhibited by stable expression of a dominant negative mutant inhibitor, IkappaBalphaM. Human lines UM-SCC-9, 11B and 38, previously shown to exhibit constitutive activation of NF-kappaB, were found to be highly resistant to growth inhibition by up to 10(4)U/ml of TNF-alpha in 5 day MTT assay. These TNF-alpha resistant HNSCC lines expressed TNF receptor I, and exhibited constitutive and TNF-alpha-inducible activation of NF-kappaB as demonstrated by nuclear localization of NF-kappaB p65 by immunohistochemistry. UM-SCC-9 I11 cells which stably expressed an inhibitor of NF-kappaB, IkappaBalpham, were susceptible to TNF-alpha-induced growth inhibition. DNA cell cycle analysis revealed that TNF-alpha induced growth inhibition was associated with accumulation of cells with sub-G0/G1 DNA content. Cell death was demonstrated by trypan blue staining, and was blocked by caspase inhibitor. We conclude that HNSCC that exhibit constitutive and TNF-alpha-inducible activation of transcription factor NF-kappaB are resistant to TNF-alpha, and that inhibition of NF-kappaB sensitizes HNSCC to TNF-alpha caspase-mediated cytotoxicity. The demonstration of the role of activation of NF-kappaB in resistance of HNSCC to TNF-alpha may be helpful in the identification of potential targets for pharmacological, molecular and immune therapy of HNSCC.

Apoptosis↗
PubMed2000

Cyclooxygenase regulates human oropharyngeal carcinomas via the proinflammatory cytokine IL-6: a general role for inflammation?

High levels of prostaglandins are produced in human oropharyngeal carcinoma (OPC). Five human OPC cell lines tested expressed both isoforms of cyclooxygenases (COX). The pan-COX inhibitor ketorolac continuously and significantly decreased PGE(2) production and IL-6 and IL-8 levels in all OPC cell lines tested, but did not affect IL-1alpha, GM-CSF levels, or in vitro tumor cell growth. In contrast, ketorolac reduced OPC growth in vivo. The OPC cell lines used express the IL-6 receptor, and IL-6 stimulation of these cells causes transduction to occur via STAT3 pathway activation. Coincubation with OPC cell lines with conditioned medium from a TPA-exposed HL-60 cells stimulated growth proportional to the IL-6 levels measured in the conditioned medium. This growth effect was specifically inhibited by anti-IL-6 antibody. These results are consistent with cytokine products of inflammatory cells having paracrine growth effects on OPC. If chronic inflammation plays a role in promoting the development of OPC, this mechanism may also apply to other epithelial tumor systems modulated by COX activity.

Animals↗
PubMed2000

Contribution of conventional axial computed tomography (nonhelical), in conjunction with panoramic tomography (zonography), in evaluating mandibular fractures.

Previous studies comparing the sensitivity between different radiological exams have concluded that conventional axial computed tomography (CT; nonhelical) is unsuitable in the assessment of mandibular fractures. Axial CT was shown to have a reduced sensitivity compared with plain radiographs and panoramic tomography because it missed nondisplaced fractures in the posterior portion of the mandible. Because the resolution of CT has improved from the time of these previous studies, the authors were interested in assessing whether axial CT (nonhelical) could now provide additional clinically useful information and enhance our understanding of mandibular fractures, beyond that obtained from panoramic tomography alone. In their study, 5 staff surgeons initially evaluated the panoramic tomograms and then the CT scans of 39 patients with 66 fractures. A series of four questions assessed the relative contribution of these two radiological exams in formulating an optimal operative plan for each patient. The authors found that axial CT provided supplementary information regarding missed fractures, comminution, and the exact size and degree of displacement of fracture fragments. This additional data could have changed the operative plan in a substantial proportion of patients (17 of 39). Axial CT demonstrated two missed parasymphyseal fractures (2 of 39 patients) that were not seen on these patients' panoramic tomograms. Axial CT also revealed undiscovered comminution or demonstrated fracture displacement more precisely in 39% of patients (15 of 39) and 24% of fractures (16 of 66). This study demonstrates that axial CT was clinically useful as an additional investigation to panoramic tomography. Axial CT helped elucidate further the nature of suspected mandibular fractures.

Humans↗
PubMed2000

Radiation dose to otologic structures during head and neck cancer radiation therapy.

BACKGROUND: Otologic structures are often contained within head and neck cancer radiation treatment ports. The dosimetry to otologic structures has not been routinely analyzed and radiation treatment planning does not currently attempt to specifically avoid the inner ear structures when dosimetry is calculated. Recent studies demonstrate that up to 30% of patients experience sensorineural hearing loss on multimodality therapy with cisplatin and radiation. METHODS: In the current case series, radiation dosimetry to otologic structures was calculated from computed tomogram treatment plans on patients. Fifteen nasopharyngeal, oral cavity, oropharyngeal, and hypopharyngeal cancer patients were analyzed. RESULTS: Between 8% and 102% of the total dose is delivered to the petrous bone/cochlea, with 4 of 15 patients getting more than 50% of the dose to at least one cochlea The mastoid air cells received between 3% and 75% of the total dose, with higher doses being delivered to patients with bulky high neck metastases or nasopharyngeal tumors. The eustachian tubes received between 20% and 102% of the total dose, with 10 of 15 patients receiving more than 50% of the dose to this anatomic site. CONCLUSION: We conclude that the cochlea and eustachian tubes receive significant radiation during treatment, particularly in nasopharyngeal cancer patients. Careful design of radiation treatment ports may allow for the reduction of radiation to hearing structures.

Carcinoma, Squamous Cell↗
PubMed1999

Expression of a dominant-negative mutant inhibitor-kappaBalpha of nuclear factor-kappaB in human head and neck squamous cell carcinoma inhibits survival, proinflammatory cytokine expression, and tumor growth in vivo.

We demonstrated recently that constitutive expression of proinflammatory cytokines interleukin (IL)-1alpha, IL-6, IL-8, and granulocyte-macrophage colony-stimulating factor in head and neck squamous cell carcinoma is correlated with activation of transcription factor nuclear factor (NF)-kappaB/Rel A (p50/p65), which binds the promoter region within each of the genes encoding this repertoire of cytokines. NF-kappaB can be activated after signal-dependent phosphorylation and degradation of inhibitor-kappaBalpha and has been reported to promote cell survival and growth. In the present study, we expressed a phosphorylation site mutant of inhibitor-kappaBalpha (IkappaBalphaM) in head and neck squamous cell carcinoma lines UM-SCC-9, -11B, and -38 to determine the effect of inhibition of NF-kappaB on cytokine expression, cell survival in vitro, and growth in vivo. After transfection with IKBalphaM, only a few UM-SCC-9 clones were obtained that stably expressed the mutant IkappaB, suggesting that expression of a mutant IkappaBalpha may affect survival of the transfected UM-SCC cell lines. After cotransfection of IkappaBalphaM with a Lac-Z reporter, we found that the number of surviving beta-galactosidase-positive cells in the three cell lines was reduced by 70-90% when compared with controls transfected with vector lacking the insert. In UM-SCC-9 cells that stably expressed IkappaBalphaM, inhibition of constitutive and tumor necrosis factor-a induced NF-kappaB activation, and production of all four cytokines was observed. Although UM-SCC-9 IkappaBalphaM-transfected cells proliferated at the same rate as vector-transfected cells in vitro, a significant reduction in growth of tumor xenografts was observed in SCID mice in vivo. The decreased growth of UM-SCC-9 IkappaBalphaM-transfected tumor cells accompanied decreased immunohistochemical detection of the activated form of NF-kappaB in situ. These results provide evidence that NF-KB and IkappaBalpha play an important role in survival, constitutive and inducible expression of proinflammatory cytokines, and growth of squamous cell carcinoma. NF-kappaB could serve as a potential target for therapeutic intervention against cytokine and other immediate-early gene responses that contribute to the survival, growth, and pathogenesis of these cancers.

Animals↗
PubMed1999

Constitutive activation of transcription factors NF-(kappa)B, AP-1, and NF-IL6 in human head and neck squamous cell carcinoma cell lines that express pro-inflammatory and pro-angiogenic cytokines.

We previously reported that human head and neck squamous cell carcinomas (HNSCCs) express the pro-inflammatory and pro-angiogenic cytokines interleukin (IL)-1alpha, IL-6, IL-8, and granulocyte-macrophage colony-stimulating factor in vitro and in vivo. The promoter region of the genes encoding these cytokines include binding sites for the transcription factors nuclear factor (NF) kappaB/Rel A, activator protein-1 (AP-1), and CCAAT enhancer-binding protein beta (C/EBPbeta, or NF-IL6), which have been reported to contribute to activation of these cytokine genes. In the study presented here, we examined the activation, composition, and function of these transcription factors in HNSCC cell lines that express pro-inflammatory cytokines, by using electrophoretic mobility shift and reporter-gene assays. Constitutive activation of NF-kappaB, AP-1, and NF-IL6 DNA-binding proteins was detected. Supershift analysis with antibodies specific for NF-kappaB, AP-1, and NF-IL6 binding proteins showed that the NF-kappaB-binding protein included p65/Rel A and p50; AP-1 activity included c-jun, junB, junD, and Fra-1; and NF-IL6 included C/EBPbeta. Mutational analysis of the NF-kappaB, AP-1, and NF-IL6 sites in the IL-8 promoter region showed that NF-kappaB and AP-1 sites contributed to constitutive IL-8 reporter activity in HNSCC. HNSCC lines that exhibited increased IL-8 secretion relative to simian virus 40-immortalized and primary keratinocyte cell lines also demonstrated a concordant increase in NF-kappaB reporter activity relative to nonmalignant keratinocytes. We concluded that the early transcription factors NF-kappaB, AP-1, and NF-IL6 are constitutively activated in human HNSCC cell lines and that NF-kappaB and AP-1 promote expression of the pro-inflammatory and pro-angiogenic cytokine IL-8 in HNSCC. The demonstration of the activation of these transcription factors will be helpful in defining the identity and role of these and other early gene products that contribute to pathogenesis of the malignant phenotype in HNSCC and in defining potential targets for pharmacologic and molecular therapy of HNSCC. Mol. Carcinog. 26:119-129, 1999. Published 1999 Wiley-Liss, Inc.

CCAAT-Enhancer-Binding Proteins↗
PubMed1999

Expression of proinflammatory and proangiogenic cytokines in patients with head and neck cancer.

Altered immune, inflammatory, and angiogenesis responses are observed in patients with head and neck squamous cell carcinoma (HNSCC), and many of these responses have been linked with aggressive malignant behavior and a decrease in prognosis. In this study, we examined the hypothesis that HNSCC cells produce cytokines that regulate immune, inflammatory, and angiogenesis responses. We identified important regulatory cytokines in supernatants of well-defined and freshly cultured HNSCC cell lines by ELISA and determined whether these cytokines are detected in tumor cell lines and tissue specimens by immunohistochemistry. The serum concentration of the cytokines and cytokine-dependent acute phase inflammatory responses (i.e., fibrinogen, C-reactive protein, and erythrocyte sedimentation rate) from patients with HNSCC was determined, and the potential relationship of serum cytokine levels to tumor volume was analyzed. Cytokines interleukin (IL)-1alpha, IL-6, IL-8, granulocyte-macrophage colony-stimulating factor (GM-CSF), vascular endothelial growth factor (VEGF), and basic fibroblast growth factor were detected in similar concentration ranges in the supernatants of a panel of established University of Michigan squamous cell carcinoma (UM-SCC) cell lines and supernatants of freshly isolated primary HNSCC cultures. Evidence for the expression of IL-1alpha, IL-6, IL-8, granulocyte-macrophage colony-stimulating factor, and VEGF in HNSCC cells within tumor specimens in situ was obtained by immunohistochemistry. In a prospective comparison of the cytokine level and cytokine-inducible acute-phase proteins in serum, we report that cytokines IL-6, IL-8, and VEGF were detected at higher concentrations in the serum of patients with HNSCC compared with patients with laryngeal papilloma or age-matched control subjects (at P < 0.05). The serum concentrations of IL-8 and VEGF were found to be weakly correlated with large primary tumor volume (R2 = 0.2 and 0.4, respectively). Elevated IL-1- and IL-6-inducible acute-phase responses were also detected in cancer patients but not in patients with papilloma or control subjects (at P < 0.05). We therefore conclude that cytokines important in proinflammatory and proangiogenic responses are detectable in cell lines, tissue specimens, and serum from patients with HNSCC. These cytokines may increase the pathogenicity of HNSCC and prove useful as biomarkers or targets for therapy.

Acute-Phase Reaction↗
PubMed1998

Arachidonic acid metabolism: a primer for head and neck surgeons.

The arachidonic acid metabolites, or eicosanoids, are a large series of lipid-derived mediators capable of producing a multitude of physiologic effects in the local environment. They play important roles in a variety of signaling pathways in endocrinology, immunology, and oncology. A significant body of work in this area has occurred in squamous cell carcinomas of the head and neck over the past 15 years. This review will attempt to familiarize the head and neck surgical oncologist with the basic biochemical steps in the formation of these compounds, newer developments in the field of eicosanoid biochemistry, and related experimental evidence of the roles of these substances in head and neck cancer.

Animals↗
PubMed1998

Early-response cytokine expression in adult middle ear effusions.

Various cytokines are presently known to be associated with the regulation of inflammatory responses. In pediatric otitis media, cytokines that correlate with various degrees of inflammation are present in middle ear effusions as inflammatory mediators. The present study was undertaken to examine the potential role of the early-response cytokines, interleukin-1beta and tumor necrosis factor-alpha, in adult otitis media. Fifty-nine adults with otitis media underwent tympanocentesis, and the effusion specimens were analyzed for the presence of both cytokines by enzyme-linked immunosorbent assay methods. Eighty-eight percent of the effusions were serous in nature. Sixty-seven percent of the patients had a known history of head and neck malignancy and radiation to the temporal bone. Twelve percent of the effusions were positive for interleukin-1beta expression, compared with 85% of effusions in children with otitis media. Eight percent of the effusions contained tumor necrosis factor-alpha, compared with 85% of those collected in pediatric otitis media. All of the specimens that contained tumor necrosis factor-alpha also contained interleukin-1beta. In the present study, there was no correlation with head and neck malignancy/radiation or the clinical degree of inflammation with the presence of either cytokine. We conclude that adult otitis media is associated with lower expression of an acute inflammatory response, as judged by the levels of interleukin-1beta and tumor necrosis factor-alpha in the effusions. Additionally, adult otitis probably represents a less severe and more chronic inflammatory state in comparison with pediatric otitis media. Further analysis of inflammatory mediators in adult otitis media is necessary to evaluate the contribution of cytokines in relation to various etiologic factors.

Adult↗
PubMed1998

Histopathology of human temporal bone after cis-platinum, radiation, or both.

Preserving organs by use of multiple modalities has become protocol in treating squamous cell carcinomas of the head and neck, but cis-platinum and radiation can impair hearing. To determine the effect of cis-platinum, radiation, or a combination of these treatments on the temporal bone, we studied histopathologic slides of 15 human temporal bones: four after cis-platinum, five after radiation, two after combined treatment, and four from normal controls. Hair cells and cells in spiral ganglia were counted in reconstructed organs of Corti. Lumen-to-diameter indexes in arterioles near facial nerves were quantified for four normal controls and seven irradiated patients. Available audiograms were compared. Decreased spiral ganglion cells, loss of inner and outer hair cells, and atrophy of stria vascularis were demonstrated in groups receiving cis-platinum, radiation, and combinations, compared with age-matched controls. Arterioles around facial nerves demonstrated fibrinous clots within the intima, endothelial proliferation, and hypertrophy and fibrosis of vascular walls in smooth muscle. Fibrosis in connective tissue was clearly progressive after radiation. Cis-platinum and radiation can contribute to otologic sequelae, including sensorineural hearing losses, vascular changes, serous effusion, or fibrosis. Prophylactic treatments and techniques to deliver them should be considered for protection of temporal bones and preservation of hearing after oncologic modalities.

Adult↗
PubMed1996

Inhibition of head and neck tumor cell growth with arachidonic acid metabolism inhibition.

Head and neck tumors are known to synthesize arachidonic acid metabolites. The authors have postulated that these substances may confer growth advantage to cancer cells, and by interfering with arachidonic acid metabolism squamous cancer growth may be altered. The tongue derived squamous carcinoma cell line, SCC-25, was treated with three leukotriene synthesis inhibitors and indomethacin. A dose-dependent decrease in DNA synthesis occurred with leukotriene inhibition, but not prostaglandin inhibition. All leukotriene synthesis inhibitors produced a dramatic and immediate effect ( > 70% inhibition by 4 hours) without cytotoxicity ( > 90% trypan blue exclusion). Cell populations at 96 hours were decreased when compared to control populations. In conclusion, leukotrienes or other lipoxygenase products may play a role as growth factors for squamous cell carcinoma, and arachidonic acid inhibition may be a novel target for chemotherapeutic intervention.

Arachidonic Acid↗