Search PubMed⌕ Search

Biomedical subjects

J C Irish

Publications and source records attributed to J C Irish.

54 records · Page 3Linked to original sources
PubMed1996

Tobacco, alcohol, and oral cancer: the patient's perspective.

It is well known that smoking, chewing tobacco, and alcohol play a significant role in the etiology of oral cancer. Although this is common knowledge in the medical community, it appears that patients are not aware of this association. We performed a prospective study on all patients newly diagnosed with oral cancer and a control group without any head and neck cancer. Patients completed a questionnaire assessing their awareness of these causative factors. Other parameters measured as possible influences of patient perception included patient age, sex, smoking status, education level, occupation, and place of residence. Patients were also questioned about their knowledge of the causes of lung cancer to allow for comparison. A total of 134 patients were questioned, with 22 of the patients assigned to the oral cancer group and the second group being comprised of 112 patients without head and neck cancer. Only 20 patients (14.9%) were aware of the causative factors of oral cancer. There was no significant difference in the knowledge of causation when comparing the cancer and control group. The patient age, sex, smoking status, or place of residence did not affect their knowledge of the causes of oral cancer. There was a highly significant difference between patients of different education levels and occupations, with the more educated and higher level occupations being better informed about the causes of oral cancer. In contrast, the majority of patients were aware of smoking as a causative factor in the development of lung cancer. The results from this study demonstrate a serious lack of knowledge in the general population of known causes of oral cancer. The relevant issues are discussed and recommendations are made.

Adolescent↗
PubMed1996

Evaluation of vocal function in unilateral vocal fold paralysis following thyroplastic surgery.

Perceptual, acoustic, and aerodynamic measures of vocal function were examined, pre- and post-treatment, in nine patients who had received thyroplastic (type I) surgery for unilateral vocal fold paralysis. Following thyroplasty, the patients showed significant improvements in the following perceptual and acoustic measures of vocal function: perceived breathiness, maximum phonation time, s/z ratio, vocal shimmer, and signal-to-noise ratio. Significant post-treatment changes were also observed in the following aerodynamic measures of phonation: air pressure, average airflow, laryngeal resistance, and breath group duration. These findings suggest that a combination of perceptual, acoustic, and aerodynamic measures of vocal function may be useful for comparing the relative effectiveness of different treatment procedures (i.e., thyroplasty vs. Teflon injection) in unilateral vocal fold paralysis.

Adult↗
PubMed1995

The free flap and plate in oromandibular reconstruction: long-term review and indications.

The purpose of this study was to define the role of reconstruction plates as bone replacement in oromandibular reconstruction. From 1987 through 1991, 71 consecutive oral cancer patients underwent composite resection and reconstruction and were entered into one of two studies. In the first study of 31 patients, 15 underwent oromandibular reconstruction using a radial forearm osteocutaneous flap, while the remainder (16) received a radial forearm fasciocutaneous flap together with a mandibular reconstruction plate. The second study involved 40 subsequent patients, all receiving the latter form of reconstruction. Twenty-one of the plates were stainless steel, and the remaining 19 were of the titanium hollow screw (THORP) type. We followed the patients prospectively. We defined success as a reconstruction that we did not have to remove. Additionally, since the patients had limited life expectancy, we developed the idea of days of life lost and incorporated it into our definition of a successful outcome. Vascularized autogenous bone proved to be more successful than metallic plates used alone in terms both of reconstruction survival and of minimizing days of life lost. The overall success rate of mandibular plate reconstruction was 78.9 percent, but analysis by defect type revealed a failure rate of 35 percent when the defects were anterior and only 5 percent when they were lateral. THORP plates demonstrated a trend towards more durability. We would now recommend plate reconstruction only in lateral defects in patients with a poor prognosis.

Bone Plates↗
PubMed1995

Primary mandibular reconstruction with the titanium hollow screw reconstruction plate: evaluation of 51 cases.

Fifty-one patients undergoing surgical reconstruction of mandibular defects with the titanium hollow screw reconstruction plate over a 4-year period were analyzed. Plate failure was defined as flap necrosis, plate extrusion, or plate fracture necessitating a further surgical procedure and occurred in 12 patients (24 percent). The incidence was highest for patients who had more than three mandibular regions resected. It was not affected by the primary site of the tumor or whether the patient had received radiation therapy. Although the failure rate was the same whether the patient attained full oral function or was fed by gastrostomy, plate fracture was limited to the former group. The overall cause-specific survival rate for this group of patients was 68 and 56 percent at 1 and 2 years, respectively. In addition, 81 percent of patients attained a full oral diet.

Adult↗
PubMed1995

Laryngeal image analysis following botulinum toxin injections in spasmodic dysphonia.

The injection of botulinum toxin (BT) into laryngeal muscles has proven to be an effective treatment for spasmodic dysphonia (SD), a neurologic disorder characterized by intermittent vocal spasms during speech. BT treatment has reduced abnormal laryngeal muscle hyperactivity in SD patients, when measured by subjective visual rating scales. This paper utilizes images obtained from endoscopic laryngeal video recordings to quantify changes in pre- and post-injection parameters of 17 patients following bilateral BT injections. A previous study, utilizing perceptual, acoustic, and laryngeal aerodynamic measures, showed significant improvements following treatment with BT. In addition, post-injection vocal rest, rather than vocalization, enhanced therapeutic responses. Results of these measures are compared with data from the image analyses and those parameters that proved to be the most useful are highlighted.

Adult↗
PubMed1995

Effect of neuromuscular activity on the response to botulinum toxin injections in spasmodic dysphonia.

Spasmodic dysphonia (SD), a neurologic disorder characterized by involuntary vocal spasms during speech, has been effectively treated by injections of botulinum toxin (BT) into the laryngeal muscles. The aim of the present study was to determine if the therapeutic response to BT is enhanced by immediate and continuous activation of the injected muscles. Twenty SD patients were randomized into two groups following bilateral injections: vocal rest for 30 minutes and continuous vocalization for 30 minutes. Evaluations consisted of voice ratings by expert observers, acoustic measurements using computer analyses, and laryngeal aerodynamic measurements. The findings suggest that vocal rest, rather than vocalization, produces a superior and longer lasting response in SD patients receiving BT injections. It is recommended that SD patients refrain from post-injection vocalization to maximize the therapeutic effects of BT.

Adult↗
PubMed1995

Comparison of botulinum toxin injection procedures in adductor spasmodic dysphonia.

This study compares the effects of unilateral and bilateral thyroarytenoid muscle injections of botulinum toxin in 50 patients with adductor spasmodic dysphonia. Patients were randomly assigned to two treatment groups of 25 patients each and a group of 15 normal control subjects was also included. Using a standard electromyographic guidance procedure, one patient group received unilateral thyroarytenoid muscle injections of 15 units of botulinum toxin, while the second patient group received bilateral thyroarytenoid muscle injections of 2.5 units of botulinum toxin on each side. Follow-up data were obtained at 2- and 6-week intervals. Acoustic and perceptual measures of vocal performance included maximum phonation time, fundamental frequency, standard deviation of fundamental frequency, jitter, shimmer, signal/noise ratio, voice break frequency, spasm severity rating, and vocal breathiness rating. Unilateral and bilateral group comparisons at 2-weeks postinjection revealed no significant difference on any of the measures examined. At 6-weeks postinjection, maximum phonation time was significantly lower in the bilateral group. All other measures failed to differentiate the two patient groups. These results suggest that standard unilateral and bilateral botulinum toxin injections provide equivalent degrees of improvement in the symptoms of spasmodic dysphonia. However, bilateral injections appear to be associated with a longer period of excessive phonatory airflow than do unilateral injections.

Adolescent↗
PubMed1994

H-ras oncogene mutation and human papillomavirus infection in oral carcinomas.

OBJECTIVE: Previous in vitro studies have demonstrated that transfection of an activated ras gene induces malignant transformation in epithelial cell lines infected with the human papillomavirus (HPV). The results of these studies support the hypothesis that HPV may cooperate with an activated ras gene in epithelial tumor carcinogenesis. To test this hypothesis in head and neck cancers, we screened 35 oral carcinomas for the presence of HPV DNA and for a mutated H-ras gene. DESIGN: The design of the study was screening survey type. Twenty-seven oral squamous cell carcinomas and eight verrucous carcinomas were analyzed for the presence of HPV DNA using the polymerase chain reaction, followed by Southern blot and probe hybridization. The tumors were also screened for point mutations of the H-ras gene using the polymerase chain reaction and restriction fragment length polymorphism analysis. RESULTS: Six (22%) of the 27 oral squamous cell carcinomas demonstrated point mutation in the H-ras gene. In addition, six tumors (22%) were positive for HPV DNA, with three tumors (11%) demonstrating both HPV DNA and H-ras gene point mutation. While the rate of simultaneous HPV infection and ras gene activation by point mutation was 11% in oral squamous cell carcinomas, 25% of oral verrucous carcinomas contained both HPV DNA and mutation in the H-ras gene. CONCLUSIONS: These results suggest a stronger association between HPV infection and activation of the H-ras gene in oral verrucous carcinomas. These results continue to confirm the multihit hypothesis of tumorigenesis and suggest that in some cases of oral cancer at least two of these events are H-ras gene mutation and HPV infection.

Adult↗
PubMed1994

Kimura's disease: an unusual cause of head and neck masses.

This article presents a case report of a patient who presented with Kimura's disease. Kimura's disease is an unusual condition with predilection to involve the head and neck. Since Kimura's disease often imitates a neoplastic or inflammatory process of the head and neck it behooves the otolaryngologist-head and neck surgeon to be able to recognize this entity.

Adult↗
PubMed1994

Complications associated with rigid fixation of mandibulotomies.

The complications associated with the use of rigid internal fixation in 31 consecutive patients who had undergone a mandibulotomy for the treatment of pathology of the oral cavity or oropharynx were reviewed. Rigid fixation was accomplished with two major types of systems: compression plates and reconstruction plates. Complications occurred in 11 patients (35%) with an average of 1.7 complications per patient. Most complications were minor in nature, and were treated successfully with conservative measures. Patients who had preoperative radiotherapy were more likely to develop nonunion and osteoradionecrosis. Plate exposure was the single, most common complication, accounting for 13% of the complications. No major differences were noted in the complication rates between the two systems.

Adult↗
PubMed1993

Oncogenes in head and neck cancer.

Primary head and neck squamous cell carcinomas from 58 patients were analyzed for the presence of alterations in the K-ras, raf, and erb-B oncogenes. Analysis of 17 fresh tumor specimens using sequence analysis of target sequences amplified by the polymerase chain reaction showed no evidence of mutations in the K-ras oncogene. Thirty fresh tumor specimens were analyzed for the presence of raf gene activation using Southern blot analysis. Under these conditions, no mutations in the c-raf oncogene were detected. In this study, 6 (13%) of the 47 tumors studied displayed epidermal growth factor receptor (EGFR) gene amplification and/or gene rearrangement. Overexpression of the erb-B gene was observed in 18 (67%) of the 27 head and neck tumors studied. Those patients expressing high levels of EGFR or showing EGFR amplification had tumors that were clinically more advanced. These data suggest that amplification and over-expression of the EGFR gene may be a useful diagnostic and prognostic marker in head and neck squamous cell carcinomas.

Adult↗
PubMed1993

Classification of mandibular defects.

A classification of mandibular defects based on functional as well as aesthetic factors is presented. By taking into account the difficulties in restoring form and function and not simply relying on traditional anatomic landmarks, it is hoped that this method will allow different types of reconstructions to be fairly evaluated. It also should help surgeons to tailor individual reconstructive techniques to specific clinical situations. Major difficulties in mandibular reconstruction arise when a condyle requires replacement, when there is a mucosal and/or skin component to the defect, and when the area to be reconstructed involves the anterior arch. The classification is based on three upper-case and three lower-case characters: H, C, L and o, m, s. H defects are lateral defects of any length, including the condyle but not significantly crossing the midline; L defects are the same only without the condyle; C defects consist of the entire central segment containing the four incisors and the two canines. Combinations of these letters are possible (an angle-to-angle defect, for example, is represented as LCL). Thus H and L defects may reach or even extend slightly beyond the midline but are not referred to as LC or HC unless they contain the entire central segment. The letters o (neither a skin nor a mucosal component), s (skin), m (mucosa), and sm (skin plus mucosa) are added to denote the epithelial requirement.

Bone Plates↗
PubMed1992

Accuracy of pathologic diagnosis in thyroid lesions.

Although there is much literature devoted to the role that fine-needle biopsy plays in the management of the thyroid mass, only a handful of studies deal with the diagnostic accuracy of the frozen section and final paraffin section of thyroid lesions. Fine-needle biopsy results, frozen-section diagnoses, final paraffin-section diagnoses, and panel review diagnoses were recorded for 137 consecutive patients who underwent thyroidectomy procedures. The overall accuracy of fine-needle biopsy, frozen-section, and paraffin-section diagnoses was 81%, 87%, and 94%, respectively. The high positive predictive value and specificity of both the fine-needle and frozen-section modalities suggests that intraoperative pathology consultation, given that the preoperative needle aspirate is positive for malignant neoplasia, can offer little further in the treatment of the patient. Statistical analysis of the accuracy of the three modalities suggests strategies for accurate treatment of the thyroid nodule.

Adolescent↗
PubMed1992

Oncogenes, molecular biology and the head and neck surgeon.

Advances in the treatment of head and neck cancer in the last 15 years have been largely limited to those that impact on patient morbidity while patient mortality statistics remain static. The advent of new technologies in molecular biology and immunology may provide the head and neck oncologist with the tools to impact on patient survival. The head and neck surgeon of the future will be required to have a basic understanding of their potential applications and limitations.

Base Sequence↗
PubMed1992

Prevalence of RAS oncogene mutation in head and neck carcinomas.

RAS genes encode for a protein (p21) known to play an important role in the regulation of normal signal transduction and cell growth. Activation of RAS genes have been strongly implicated in the pathogenesis of cancer in cell line studies, animal models and in human tumors. RAS genes have been shown to be mutated in 10 to 15% of human solid tumors but the frequency of mutation varies widely depending on the tumor type. The prevalence of RAS mutation has not been well-established in head and neck squamous cell carcinomas (SCC). The purpose of our study was to screen a relatively large number (50) SCC tumors using a gene amplification technique, the polymerase chain reaction (PCR). H-RAS gene mutation is identified by diagnostic restriction length polymorphism, created by introducing specific mismatched primers in the PCR. The first 20 tumors were also amplified and directly sequenced for K-RAS codon 12 and 13. Four of the 50 screened tumors were positive for H-RAS codon 12 mutation. All tumor DNA screened normal at codon 61 and the first 20 tumors were also normal at K-RAS codon 12 and 13. The prevalence of RAS mutations appears to be low in head and neck squamous cell carcinomas. Tumors positive for point mutation in the H-RAS gene revealed some unusual clinical characteristics.

Adult↗
PubMedDate not supplied

A patient- and observer-rated analysis of the impact of lateral rhinotomy on facial aesthetics.

OBJECTIVE: To determine, using patient- and observer-rated facial disfigurement measures, whether a lateral rhinotomy imparts significant aesthetic morbidity. DESIGN: Retrospective and subject-controlled study in a large, tertiary-referral, academic otolaryngology department. Twenty-one consecutive patients who had undergone lateral rhinotomy for the treatment of inverted papilloma were studied in the long-term. MAIN OUTCOME MEASURES: Scores on the following: (1) the novel Patient-Rated Facial Disfigurement Analogue Scale questionnaire and (2) the reliable and validated Observer-Rated Facial Disfigurement 9-Point Likert Scale. RESULTS: Patients rated their facial appearance as minimally altered and significantly less apparent to others. The observers in this study, a surgeon (J.C.I.) and a psychiatrist (M.R.K.), rated the patients' facial disfigurement as minimally visible. Patients seem to rate how apparent their appearance is to others in a similar fashion to observers. The observer-rated facial disfigurement scale used is valid and reliable. CONCLUSION: Patient- and observer-rated facial disfigurement measures suggest that a lateral rhinotomy does not impart significant aesthetic morbidity.

Adult↗
PubMedDate not supplied

Tumors of the skull base: outcome and survival analysis of 77 cases.

We reviewed our experience with combined approaches to lesions that transcend the bones of the skull base. Seventy-seven skull base procedures were performed on 73 patients during a 10-year period from 1982 to 1992. There were 34 patients (44%) with region lesions (anterior), seven patients (9%) with region II lesions (anterior-lateral), 25 patients (32%) with region III lesions (lateral-posterior), and 11 patients (14%) with lesions that invaded more than one anatomic site. The histopathology in this series was quite variable, with 22 patients (29%) having squamous cell carcinoma and eight patients (10%) having basal cell carcinoma. Forty-one patients had surgery by an anterior approach and 38 patients had lateral approaches, with 18 undergoing an infratemporal approach and 29 undergoing temporal bone resections. Overall, 44% of the patients had a postoperative complication. Survival of this heterogeneous group of patients is 79% at 2 years and 71% at 4 years, with those patients with region II disease having a statistically significant poorer prognosis with no survivors at 4 years.

Adolescent↗