Parathyroid surgery can be safely performed in a community hospital by experienced parathyroid surgeons: A retrospective cohort study.

Background: There is ongoing debate about the effectiveness and safety of performing parathyroid surgery in low-volume community hospitals.

Study Design/methods: Cases performed at community hospital by a group of 4 parathyroid surgeons (group 1) were reviewed. Cure and complication rates were analyzed in light of outcomes of an expert endocrine surgeon from high-volume academic center (group 2) as point of reference.

Fidelity of enzymatic ligation for DNA computing.

We describe a convenient assay for rapid qualitative evaluation of hybridization/ligation fidelity. The approach uses randomized probe strands of DNA and restriction enzyme digestion after amplification of reaction products by the polymerase chain reaction (PCR). We report ligation efficiencies and fidelities of two DNA ligases, T4 DNA ligase and Thermus aquaticus (Taq) DNA ligase, over a range of temperatures.

Molecular computation: RNA solutions to chess problems.

We have expanded the field of "DNA computers" to RNA and present a general approach for the solution of satisfiability problems. As an example, we consider a variant of the "Knight problem," which asks generally what configurations of knights can one place on an n x n chess board such that no knight is attacking any other knight on the board. Using specific ribonuclease digestion to manipulate strands of a 10-bit binary RNA library, we developed a molecular algorithm and applied it to a 3 x 3 chessboard as a 9-bit instance of this problem.

Counting DNA: estimating the complexity of a test tube of DNA.

We consider the problem of estimation of the 'complexity' of a test tube of DNA. The complexity of a test tube is the number of different kinds of strands of DNA in the test tube. It is quite easy to estimate the number of total strands in a test tube, especially if the strands are all the same length.

Chess games: a model for RNA based computation.

Here we develop the theory of RNA computing and a method for solving the 'knight problem' as an instance of a satisfiability (SAT) problem. Using only biological molecules and enzymes as tools, we developed an algorithm for solving the knight problem (3 x 3 chess board) using a 10-bit combinatorial pool and sequential RNase H digestions. The results of preliminary experiments presented here reveal that the protocol recovers far more correct solutions than expected at random, but the persistence of errors still presents the greatest challenge.

DNA solution of hard computational problems.

DNA experiments are proposed to solve the famous "SAT" problem of computer science. This is a special case of a more general method that can solve NP-complete problems. The advantage of these results is the huge parallelism inherent in DNA-based computing.

Botulinum toxin injection for adductor spastic dysphonia: patient self-ratings of voice and phonatory effort after three successive injections.

Ten patients (aged 35 to 70 years) with neurologic adductor spastic dysphonia rated themselves on a 7-point scale of severity for degree of voice improvement and physical effort after a series of three injections of botulinum toxin. Symptoms were noticeably reduced 24 and 48 hours after injection; this improvement was followed by considerable fluctuations in voice quality and phonatory effort. With successive injections, patients differed in their post-injection experiences, the time required to reach optimal voice, and the total duration of benefit.

Noninvasive technique for estimating subglottic pressure and laryngeal efficiency.

The clinical assessment of aerodynamic parameters is important in the physiology and pathophysiology of laryngeal function. Vocal efficiency is among these objective measurements and can be calculated from simultaneous recordings of subglottic pressure, airflow, and sound intensity. Modern techniques allow us to accurately determine sound intensity and airflow.

Phonatory vocal fold function in the excised canine larynx.

The development of valid objective measurements of vocal cord vibration during phonation is a goal of current research in laryngeal physiology. An excised canine larynx was used to study the effects of vocal cord tension, air flow rate, and glottic width on glottographic parameters. The electroglottographic and photoglottographic wave-forms were simultaneously recorded as the vocal cord tension, glottic width, and air flow rate were systematically varied.

Rhinolift operation in the treatment of the aging nose.

Disturbance of the normal relationship between the caudal border of the upper lateral cartilage and the cephalic margin of the lobular cartilage--the so-called "cul-de-sac" area--can result in alar collapse and nasal airway obstruction. This may be caused by either the aging process or trauma, both surgical and nonsurgical. Rhinolift is a surgical procedure that was developed for the treatment of the aging ptotic nasal tip.

Thyroid carcinoma invading the upper aerodigestive system.

Well-differentiated thyroid carcinoma infrequently invades the upper aerodigestive tract. However, when invasion occurs it is the source of significant morbidity and excess mortality. The most common structures invaded by thyroid carcinoma are the recurrent laryngeal nerves, larynx, pharynx, and esophagus, which can produce symptoms of airway insufficiency, dysphagia, and hemoptysis.

Physiologic assessment of Isshiki type III thyroplasty.

Isshiki type III thyroplasty is a laryngeal framework surgical procedure that lowers a patient's pitch. To objectively assess the procedure, preoperative and postoperative voice recordings, as well as electroglottography and photoglottography were performed. Jitter, shimmer, and glottographic quotients were measured to assess changes in vibratory pattern.

Glottographic analysis of phonation in the excised canine larynx.

An excised canine larynx model of phonation was developed to assess the effect of vocal fold length and tension on glottographic waveforms. The canine larynx in an experimentally produced phonatory model vibrated in a two-mass system comparable to human voice production. The recorded glottographic waveforms for the excised canine larynx were similar to signals recorded in humans in the chest register.

Sectional anatomy of the larynx: implications for the transcutaneous approach to endolaryngeal structures.

A transcutaneous, transcricothyroid membrane approach to endolaryngeal structures is used for several techniques such as placement of electrodes for laryngeal electromyography and transcutaneous Teflon injection of the paralyzed vocal fold. The purpose of this study is to examine the sectional anatomy of the larynx with respect to the cricothyroid membrane and describe a suitable transcutaneous approach to endolaryngeal structures. Sixteen whole organ cadaveric larynges were frozen in clear gelatin to facilitate sectioning.

Intraoperative electrophysiologic monitoring of laryngeal muscle during thyroid surgery.

A technique is described for intraoperative electrophysiologic monitoring of laryngeal muscles. This technique has been used to identify the laryngeal nerves during surgery for recurrent tumors of the thyroid gland, when direct visualization of the nerves is difficult or impossible. Laryngeal muscle electrical activity is monitored with endoscopically placed wire-hook electrodes inserted into the vocal folds bilaterally.

Surgical treatment of invasion of the upper aerodigestive tract by well-differentiated thyroid carcinoma.

Forty-eight patients with well-differentiated thyroid carcinoma invading upper aerodigestive tract structures have been described. Age at diagnosis was found to be a negative prognostic factor, and duration of disease before invasion was found to be a positive prognostic factor. Treatment with radical surgery and adjuvant therapy provided no improvement in survival over treatment with near-total (skeletonizing) excisions combined with adjuvant therapy.

Exercise-induced reversal of age-related declines of oxidative reactions, mitochondrial yield, and flavins in skeletal muscle of the rat.

The ability of gastrocnemius muscle homogenates to catalyze the oxidation of succinate, glutamate + malate, pyruvate + malate, palmitoyl-coenzyme A, decanoylcarnitine and palmitoylcarnitine in the presence of ADP decreased by approximately 32% in sedentary male Sprague-Dawley rats between the ages of 9 and 25 months. Following 21 weeks of treadmill training (running), such homogenates from 25-month-old animals catalyzed oxidations 55% more rapidly than those from 25-month-old sedentary rats, and 17% faster than those from 9-month-old sedentary rats. Total and peptide-bound flavin of gastrocnemius muscles also declined between 9 and 25 months of age and were elevated in the 25-month-old endurance trained rats to levels greater than both 9- and 25-month-old sedentary animals.