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Biomedical subjects

S M Parnes

Publications and source records attributed to S M Parnes.

At least 37 records · Page 2Linked to original sources

External rhinoplasty approach to transsphenoidal hypophysectomy.

The external rhinoplasty approach is a modification of the well recognized transseptal transsphenoidal hypophysectomy technique first introduced by Cushing in 1910. Our approach has been used successfully in 75 cases over a six year period, demonstrating its efficacy and safety. It provides a simple, reliable, rapid technique for exposing the septum and the floor of the nose with excellent exposure to the sphenoid sinus and pituitary gland. There has been no loss of nasal tip projection or other cosmetic deformity.

Adolescent↗

Predictive value of the Glasgow Coma Scale for tracheotomy in head-injured patients.

Patients with severe head trauma often require prolonged intubation and subsequent tracheotomy. The Glasgow Coma Scale (GCS), an indicator of the severity of head injury, may help identify that subpopulation of trauma victims who will ultimately undergo tracheotomy. This retrospective study demonstrates through discriminant analysis that the likelihood of tracheotomy is significantly greater in patients with a GCS rating less than or equal to 7 than it is in patients with a GCS rating greater than 7 (p = .0001). Conversely, the presence of thoracoabdominal or maxillofacial injury is associated with but not predictive of eventual tracheotomy. In the hope of minimizing complications and enhancing the utilization of hospital resources, this study argues for early tracheotomy in patients with a GCS score less than or equal to 7 who do not undergo craniotomy and are otherwise stable.

Adolescent↗

Asbestos and cancer of the larynx: is there a relationship?

A head and neck examination was conducted on 322 personnel in a plant that manufactures brake linings and disks where asbestos is a major component. The personnel were categorized according to occupational risk, duration of employment, and smoking and alcohol habits. Thirty-nine percent had abnormalities, the most common being laryngitis (15%), deviated nasal septum (13%), and neck mass (5.3%). Six members required a biopsy, but no cancer was discovered. Of 47 personnel with laryngitis, 46 were smokers (P less than .01). In regard to asbestos exposure, 20% of the high-risk group had laryngitis, compared to 11% in the low-risk group (P less than .05). The data were compared to a previously prepared longitudinal study of plant personnel (2057 individuals and 37,361.5 person years), where three cases of laryngeal cancer had been observed (0.77 expected). As these cases involved smokers with limited asbestos exposure, neither the longitudinal or cross-sectional data could support asbestos as an etiologic factor for laryngeal cancer, but it may act as an irritant.

Adult↗

Early complications of airway management in head-injured patients.

Head-injured patients are frequently young, healthy individuals whose excellent medical condition is suddenly altered by trauma. The purpose of this study is to evaluate the early complications of airway management which occur in head-injured patients and to determine if these are different from what has been reported in patients with chronic illnesses (i.e., diabetes, atherosclerosis, or immunosuppression). Chart review of 52 head-injured patients reveals an early complication rate of 61% for endotracheal intubation and 20% for tracheotomy. Discriminant analysis shows that increasing duration of intubation is the most significant factor in predicting airway management complications (P less than 0.008). The incidence of complications seen in head-injured patients is similar to that of the chronically ill. Complications of endotracheal intubation are judged to be more severe than those of tracheotomy. Data from this study supports the early tracheotomy of severely head-injured patients who are likely to require prolonged airway management.

Adolescent↗

Comparison of computed tomography and magnetic resonance imaging in chronic otitis media with cholesteatoma.

We prospectively studied 10 patients with chronic otitis media suspected of having cholesteatoma with computed tomography and magnetic resonance imaging to assess which imaging modality would be most specific in predicting the presence of cholesteatoma. The interpretation of images was then correlated with the operative findings. In 9 of the 10 cases, computed tomography accurately predicted the extent and destructiveness of the disease but did not consistently differentiate between cholesteatoma and associated granulation tissue. In 2 of the 10 cases, the T1-weighted magnetic resonance imaging demonstrated high signal, suggestive of cholesteatoma. In one case, magnetic resonance imaging predicted cholesteatoma on the basis of bony destruction. However, in 7 of 10 cases the scan was nonspecific for cholesteatoma. We conclude that high-resolution computed tomography remains the primary imaging modality for chronic otitis media.

Cholesteatoma↗

Accuracy of the subrenal capsule xenograft assay in predicting the clinical growth and chemosensitivity of human squamous head and neck carcinomas.

Thirty-seven of 54 human squamous head and neck carcinomas were successfully grown as first transplant generation xenografts under the kidney capsule of conventional mice immunosuppressed by daily treatment with 60 mg/kg of cyclosporine. Of the 18 different tumors evaluated for chemosensitivity, 39% responded to cis-platinum, 19% to 5-fluorouracil, 33% to methotrexate, and 40% to Cis-Pt/5Fu. In comparing the assay results in nine patients who received the same chemotherapeutic drugs, two of three patients responded to their drug with xenograft shrinkage noted, whereas four of six patients who did not respond had tumor growth in the mouse. It is hoped that this model will become useful for new drug testing and, in certain cases, for selection of chemotherapy for patients with refractory tumors.

Animals↗

Growth and chemosensitivity of human head and neck cancers implanted under the kidney capsule of cyclosporine-immunosuppressed mice.

Thirty-seven of 54 human squamous cell head and neck carcinomas were grown successfully at first transplant generation xenografts under the kidney capsule of conventional mice immunosuppressed by daily treatment with 60 mg/kg of cyclosporine. Eighteen different tumors were evaluated for chemosensitivity to cis-diamminedichloroplatinum (cisplatin), 5-fluorouracil, and methotrexate. Thirty-nine percent of the tumors responded to cisplatin, 19% to 5-fluorouracil, and 33% to methotrexate. This assay response is consistent with the clinical response of human squamous head and neck carcinoma to these drugs used as single agents. It is hoped that this model will become useful for new drug testing and, in certain cases, for selection of chemotherapy for patients with refractory tumors.

Animals↗

Ciprofloxacin for the treatment of chronic ear disease.

The treatment of chronic ear disease is often difficult and frustrating. Patients typically present with a history of chronic, persistent otorrhea that has failed to respond to multiple topical and oral antibiotics. Organisms that are resistant to multiple antibiotics are common. Ciprofloxacin has been shown to be effective against a wide range of gram-negative and gram-positive organisms. To evaluate the role of ciprofloxacin in the treatment of chronic ear disease, 21 patients who failed routine therapy for chronic ear disease were prospectively treated with oral ciprofloxacin. Prior to therapy, all ear cultures grew Pseudomonas aeruginosa, Staphylococcus aureus or other gram-negative organisms. Ninety-five percent of patients completing therapy showed either improvement or cure. Only one patient failed to improve. Ciprofloxacin has been shown to be effective in the management of chronic ear disease.

Adult↗

Establishment and characterization of two new squamous cell carcinoma cell lines derived from tumors of the head and neck.

Two human cell lines were established from untreated squamous cell carcinomas of the head and neck. Line 183 was derived from a head and neck squamous cell carcinoma of the tonsil and 1483 from a head and neck squamous cell carcinoma of the retromolar trigone. Both lines grow in a cobblestone pattern demonstrating their epithelial heritage. Immunofluorescence studies and one-dimensional polyacrylamide gel electrophoresis indicated that both lines contain cytokeratins. Line 1483 is more aggressive in nude mice, has a higher efficiency for anchorage-independent growth, expresses p21ras (product of the ras oncogene) at a higher level, and is more aneuploid than 183. 1483 also grows as a multicellular tumor spheroid. Line 1483, which was established from the primary tumor of a patient with nodal metastasis, thus displays more progressed characteristics than line 183, which was established from a patient with no clinically positive nodes.

Aged↗

Noninvasive imaging of the normal temporal bone. Comparison of sagittal surface coil magnetic imaging and high-resolution computed tomography.

High-resolution computed tomography (HRCT) is a noninvasive technique for evaluating the middle ear for primary and recurrent cholesteatoma. However, a limitation of HRCT is that it cannot differentiate between cholesteatoma and granulation tissue. Magnetic resonance imaging (MRI) is a noninvasive, nonradiologic technique that has been effective in demonstrating histochemical differences between various soft tissues. We present images from a normal living subject's temporal bone in the sagittal plane obtained with both HRCT and MRI. Anatomic correlates in the same cut planes are presented. The HRCT provided excellent detail of the bony landmarks within the temporal bone and was used as the reference for the MRI. The soft-tissue structures such as cranial nerves, cochlea, vestibule, and semicircular canals were identified.

Humans↗

Effects of lidocaine infusion in cats after unilateral labyrinthectomy.

In the auditory/vestibular system, intravenous lidocaine hydrochloride administration has been reported to provide transient relief from severe tinnitus, reduce dizziness and emesis accompanying Meniere's disease, and sometimes improve audiometric thresholds in sensorineural hearing loss. In this study, the labyrinth was destroyed unilaterally in a series of cats. Animals constantly fell and demonstrated prominent contralateral nystagmus and a rotary motion of the head. Within four hours of a 4-mg/kg intravenous lidocaine hydrochloride injection, the cats were able to ambulate freely without falling. The nystagmus was reduced, and there was virtual absence of the rotary head motion. In contrast, the controls had persistent signs of vestibular disturbance. These results demonstrate that lidocaine infusion ameliorates the effects of unilateral labyrinthectomy in cats and thus may be a potential antivertiginous agent.

Adaptation, Physiological↗

A multiple-baseline evaluation of the treatment of subjective tinnitus with relaxation training and biofeedback.

Six subjects with subjective tinnitus received training in relaxation techniques and EMG and thermal biofeedback in a multiple-baseline across-subjects design. Daily tinnitus disturbance and sleep disturbance diaries were kept throughout. Audiological and psychological evaluations were made at various treatment phases. At posttreatment assessment, subjects also completed global ratings of their perceived improvement in ability to cope with the tinnitus, stress caused by the tinnitus, and severity of the tinnitus, as well as their overall satisfaction with the treatment. Ratings on the global scales were generally very positive. By way of contrast, the daily diary results revealed little if any treatment effect. The implications of these disparate results are discussed.

Adult↗

External rhinoplasty approach to transsphenoidal hypophysectomy.

The history of transsphenoidal hypophysectomy demonstrates the soundness of the basic concept of approaching the sella turcica in a midline fashion through the nose. Conceptually, it has not been eclipsed since first evolved by Cushing in the early part of this century. The surgical advances since Cushing's time have been major refinements in instrumentation and minor refinements of his basic technique. The external rhinoplasty approach is such a refinement. We have used this technique in a two-year period between June 1982 and June 1984 on 14 patients. We have found this technique for transsphenoidal hypophysectomy to be a simple, reliable, rapid technique for exposing the septum and the floor of the nose. It provides excellent exposure to the sphenoid sinus and pituitary gland without loss of nasal tip projection or other cosmetic deformity.

Adult↗

In vitro modulation of differentiation by calcium in organ cultures of human and murine epithelial tissue.

The differentiation of epithelial tissue in organ cultures of murine buccal mucosa, various human oral mucosa, and human newborn foreskin was found to be dependent on the calcium concentration of the culture media. In low calcium medium (less than or equal to 0.07 mM) epithelial differentiation was inhibited. The original stratifying layers separate and can be removed, producing a destratified explant. Histologically such an explant consists of a dorsal epithelial layer of basal keratinocytes resting on an intact basal lamina with subjacent stroma. At 0.01 mM calcium, the epithelial layer was one to two cells thick whereas at 0.07 mM it could be three or more layers in thickness with the most superficial cells being spread over the underlying cells. In addition to differentiation, keratinocyte migration over the sides of the explant (epiboly) and epithelial proliferation as determined by [3H]thymidine autoradiography were reduced by culture in low calcium medium. Redifferentiation occurs upon return to normal calcium levels (1.8 mM); addition of hydrocortisone to low calcium media was found to facilitate this redifferentiation.

Adult↗

Congenital calcification of the larynx and trachea.

The fifth case of diffuse laryngeal and tracheal cartilage calcification in infancy is reported. The previously reported cases are briefly described. Differential diagnosis and potential etiologies are discussed. It is thought that these patients represent a rare but distinct clinical entity.

Calcinosis↗