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C T Sasaki

Publications and source records attributed to C T Sasaki.

At least 19 recordsLinked to original sources
PubMed1992

Squamous cell carcinoma arising in a thyroglossal duct cyst.

Carcinoma arising in a thyroglossal duct cyst is a rare event, occurring in less than 1% of abnormalities of the thyroglossal duct. To date, there have been approximately 100 cases reported, with papillary carcinoma accounting for the vast majority. Squamous cell carcinoma, on the other hand, is an even rarer event. Its clinical course in the elderly, consisting of recurrent drainage and suppuration, may distinguish it from other neoplastic conditions of thyroglossal duct cyst. We present a 65-year-old man with squamous cell carcinoma in a recurrently discharging thyroglossal duct cyst to illustrate important distinguishing clinical features of this condition.

Aged↗
PubMed1991

Effective head and neck tumor markers. The continuing quest.

To evaluate the clinical value of two serologic tumor markers, squamous cell carcinoma-associated antigen and plasma lipid-bound sialic acid, for identifying cancers of the head and neck, plasma specimens were obtained from patients receiving care for untreated newly diagnosed cancers of the head and neck, routine surveillance for recurrence, or treatment for chronic nonmalignant otolaryngologic conditions. Using identical methods at two institutions, levels of both markers were determined blind to diagnoses for patients with biopsy-proven cancers of the head and neck (n = 134) and for those defined as cancer free based on clinical evaluation for 6 months (n = 140). Disease status was determined blind to tumor marker level results. Cancer prevalence was 48.9%. Applying standard normal limits used alone, plasma lipid-bound sialic acid test sensitivity was 63.4% and specificity was 77.9%. For squamous cell carcinoma-associated antigen alone, test sensitivity was 27.6% and specificity was 85.0%. Neither test alone appears sensitive enough to effectively detect early cancers of the head and neck. When the results of both tests in series combination were positive, sensitivity was 18.7% and specificity was 95.0%. If either was positive in parallel combination, sensitivity was 72.4% and specificity was 68.0%. Further evaluation is required that applies different definitions of normal and determines longitudinal changes with disease status.

Antigens, Neoplasm↗
PubMed1991

Posterior cricoarytenoid muscle denervation.

Vocal fold paralysis most commonly results from injury to the recurrent laryngeal nerve. The length of time required for denervation atrophy would be useful in planning reinnervation procedures. Given the absence of long-term data on the status of the canine posterior cricoarytenoid muscle following denervation, this study was undertaken. The results indicate that muscle atrophy does not occur for at least 1 year following denervation.

Animals↗
PubMed1991

Quinine-induced tinnitus in rats.

Quinine ingestion reportedly induces tinnitus in humans. To expand our salicylate-based animal model of tinnitus, a series of conditioned suppression experiments was performed on 54 male-pigmented rats using quinine injections to induce tinnitus. Quinine induced changes in both the extent of suppression and recovery of licking, which followed a pattern that paralleled those produced after salicylate injections, and which may be interpreted as the result of tinnitus perception in animals. These changes depended on the dose and time schedule of quinine administration. Additionally, the calcium channel blocker, nimodipine, abolished the quinine-induced effect in a dose-dependent manner.

Animals↗
PubMed1991

Pacing parameters of the canine posterior cricoarytenoid muscle.

The electrical pacing of laryngeal tissue consists of many uncharted parameters. We carried out several acute experiments in the canine model to narrow parametric ranges to serve future research and development in this field. Our findings were as follows. Stimulation intensities greater than 6 V caused tissue damage. Optimum stimulation frequency ranged from 60 to 90 Hz. Optimum pulse duration was 2.0 milliseconds. Biphasic stimulation reduced accumulation of electrical charge at the electrodes.

Animals↗
PubMed1991

Laryngeal anatomy and physiology.

Much has been learned about the normal function of the larynx. As is perhaps obvious from our article, much, much more needs to be learned about its function in altered and disease states.

Adult↗
PubMed1990

Spontaneous trigeminal-facial reinnervation.

Although spontaneous recovery of denervated facial muscles has been anecdotally recorded in the clinical setting, it has never been fully documented. The establishment of anastomoses between the terminal trigeminal and facial nerves provides a possible explanation of this phenomenon. Mechanisms of myoneurotization have also been described, by which regenerating branches of severed peripheral motor nerves directly reach motor end plates of denervated muscles, with variable recovery of function. A case demonstrating unequivocal clinical evidence of trigeminal-facial cross-innervation is presented, and the pertinent literature is reviewed as it applies to the mechanisms of this phenomenon.

Adult↗
PubMed1990

Laryngeal chondrosarcoma: incidence, pathology, biological behavior, and treatment.

Chondrosarcoma is the most common mesenchymal tumor of the larynx and approximately 200 cases have been collected in the world medical literature. It is less aggressive in the larynx than elsewhere: cervical or distant metastases are rare (8.5%), and although local recurrences are not uncommon, they are not catastrophic. A retrospective study was made on eight cases of laryngeal chondrosarcoma. Three cases had originally been diagnosed as idiopathic vocal cord paralysis, possibly because of early involvement of the cricoarytenoid joint or the distal portion of the recurrent nerve. This fact emphasizes the need for accurate laryngeal computed tomography in cases of vocal cord paralysis of unknown origin. Surgical excision is the treatment of choice for laryngeal chondrosarcoma, and conservative techniques may sometimes be appropriate. Supraglottic laryngectomy may be the technique of choice in the rare cases of epiglottic involvement.

Adult↗
PubMed1990

Allogeneic (homograft) reconstruction of the mandible.

Reconstruction of the tumor-ablated patient remains one of the most challenging problems for the head-and-neck surgeon. Various methods have been described, including alloplastic reconstruction, free vascularized flaps, osteomyocutaneous flaps, and allogeneic reconstruction with particulate marrow grafts. Sixteen patients who have undergone homograft mandibular replacement at the Yale New Haven Hospital are described. Eighty-one percent of these grafts were successful in restoring form and function to a high degree of patient satisfaction. Eleven of the sixteen patients had radiation therapy after initial tumor surgery; 91% of these grafts were successful.

Adult↗
PubMed1990

Longitudinal voice quality changes following Isshiki thyroplasty type I: the Yale experience.

Longitudinal voice quality changes following Isshiki thyroplasty type I were investigated in a group of 13 patients exhibiting unilateral vocal fold paralysis. Thyroplasty type I medializes the paralyzed fold by using a Silastic implant for external lateral compression of the abducted fold. No perioperative complications were experienced. We observed significantly higher voice fundamental frequency, significantly louder voice intensity, and significantly longer maximum phonation time, both immediately following phonosurgery and up to 3 months postoperatively. Surgical refinements of thyroplasty type I are described.

Adult↗
PubMed1990

Le Fort I osteotomy approach to the skull base.

Horizontal osteotomy allows the surgeon to safely down-fracture the maxilla for wide exposure of the central skull base. This surgical approach is easily extended posteriorly in the midline to include the clivus and the arch of C1, providing 8 cm of horizontal anterior exposure and 5 cm of posterior. Wide operative exposure and a low rate of complications afford superior functional and cosmetic preservation in removing tumors of the central cranial base.

Adolescent↗
PubMed1989

Anatomic foramina in the thyroid cartilage: incidence and implications for the spread of laryngeal cancer.

Anatomic openings in the posterosuperior portion of the thyroid lamina of the larynx were first described in the 19th century. In the present study of 121 coronally sectioned larynges, such openings were found in 47 (39%), appearing bilaterally in 15 and unilaterally in 32. In a separate study of 69 cadaver larynges, the openings were found in 39 (57%), appearing bilaterally in 16 and unilaterally in 23. In 51 laryngectomy specimens removed for squamous cell cancer and showing foramina, tumor was not observed to invade or traverse the foramen in a single case, even in those specimens with tumor overlying the foramen and displaying framework invasion at other sites. Invasion by cancer through the foramen appears to be prevented by a layer of fibroelastic tissue overlying the medial surface of the foramen, parallel to the inner surface of the thyroid lamina. This layer of fibroelastic tissue may represent perichondrium.

Adenocarcinoma↗
PubMed1989

Delayed diagnosis and treatment of acoustic neuroma.

The records of 25 patients who underwent excision of acoustic neuroma between 1980 and 1987 were reviewed. All patients originated from southern New England. Facial nerve function was preserved in 92% of all patients, and 42% of patients with tumors less than 2.0 cm retained residual hearing postoperatively. These rates compare favorably with those found in larger series. Our series demonstrated that 60% of patients complained of hearing loss for longer than 2 years prior to tumor diagnosis. The mean duration of hearing loss prior to diagnosis was 4.2 years. Although sophisticated diagnostic methods were generally available, early detection of tumors did not occur, despite the early onset of auditory symptoms. The emergence of sophisticated computer-assisted diagnostic tests and the development of technologically advanced operative methods have reduced operative morbidity, but interestingly, have had little influence on early tumor diagnosis. Late detection of acoustic neuroma in an otherwise medically sophisticated community suggests the need for improved awareness among patients and their primary care providers. Failure of early detection may occur more commonly than generally appreciated, despite the availability of technologically advanced methods of diagnosis.

Adult↗
PubMed1988

Pigmentation, anesthesia, behavioral factors, and salicylate uptake.

In four experiments, 54 pigmented rats were used to examine the time course of sodium salicylate uptake in serum, cerebrospinal fluid, and perilymph. Subjects were tested under sodium pentobarbital anesthesia or while conscious. Compared with previously reported data from albino rats, pigmented subjects generally showed increased salicylate uptake. Moreover, the data suggested two different, time-dependent clearance mechanisms in conscious animals not observed in anesthetized rats. Daily injections of salicylate did not produce an accumulation of salicylate in serum. Systematically higher levels of salicylate were observed in perilymph compared with cerebrospinal fluid. Behavioral procedures, including water deprivation and conditioned suppression of ongoing drinking levels, had no effect on salicylate levels.

Anesthesia↗
PubMed1988

Phantom auditory sensation in rats: an animal model for tinnitus.

In order to measure tinnitus induced by sodium salicylate injections, 84 pigmented rats, distributed among 14 groups in five experiments, were used in a conditioned suppression paradigm. In Experiment 1, all groups were trained with a conditioned stimulus (CS) consisting of the offset of a continuous background noise. One group began salicylate injections before Pavlovian training, a second group started injections after training, and a control group received daily saline injections. Resistance to extinction was profound when injections started before training, but minimal when initiated after training, which suggests that salicylate-induced effects acquired differential conditioned value. In Experiment 2 we mimicked the salicylate treatments by substituting a 7 kHz tone in place of respective injections, resulting in effects equivalent to salicylate-induced behavior. In a third experiment we included a 3 kHz CS, and again replicated the salicylate findings. In Experiment 4 we decreased the motivational level, and the sequential relation between salicylate-induced effects and suppression training was retained. Finally, no salicylate effects emerged when the visual modality was used. These findings support the demonstration of phantom auditory sensations in animals.

Animals↗
PubMed1988

The use of topical oral antibiotics in head and neck prophylaxis: is it justified?

Systemic antibiotic therapy is widely used for prophylaxis in major head and neck surgery, but the efficacy of topical oral antibiotic therapy has not been adequately investigated. A pilot, placebo-controlled, double-blind crossover study using six healthy adult male volunteers was performed to assess the influence of topical clindamycin on oral flora. Samples of saliva were cultured for aerobic and anaerobic bacteria immediately before, and at 1- and 4-hour intervals after, rinsing the mouth with a solution of either placebo or clindamycin. Quantitative analysis demonstrated significantly reduced levels of both aerobic and anaerobic bacteria after use of the topical antibiotic at both the 1- and 4-hour intervals. It is postulated that topical clindamycin, by reducing concentrations of oral flora, may also reduce the incidence of regional infection following major upper aerodigestive tract surgery.

Administration, Oral↗
PubMed1988

An animal model for tinnitus.

Subjective tinnitus remains obscure, widespread, and without apparent cure. In the absence of a suitable animal model, past investigations took place in humans, resulting in studies that were understandably restricted by the nature of human investigation. Within this context, the development of a valid animal model would be considered a major breakthrough in this field of investigation. Our results showed changes in the spontaneous activity of single neurons in the inferior colliculus, consistent with abnormally increased neuronal activity within the auditory pathways after manipulations known to produce tinnitus in man. A procedure based on a Pavlovian conditioned suppression paradigm was recently developed that allows us to measure tinnitus behaviorally in conscious animals. Accordingly, an animal model of tinnitus is proposed that permits tests of hypotheses relating to tinnitus generation, allowing the accommodation of interventional strategies for the treatment of this widespread auditory disorder.

Animals↗