The administration to Indonesians of monosodium L-glutamate in Indonesian foods: an assessment of adverse reactions in a randomized double-blind, crossover, placebo-controlled study.

Monosodium L-glutamate (MSG) has been suggested to cause postprandial symptoms after the ingestion of Chinese or oriental meals. Therefore, we examined whether such symptoms could be elicited in Indonesians ingesting levels of MSG typically found in Indonesian cuisine. Healthy volunteers (n = 52) were treated with capsules of placebo or MSG (1.5 and 3.0 g/person) as part of a standardized Indonesian breakfast. The study used a rigorous, randomized, double-blind, crossover design. The occurrence of symptoms after MSG ingestion did not differ from that after consumption of the placebo.

Monosodium L-glutamate: a double-blind study and review.

71 healthy subjects were treated with placebos and monosodium L-glutamate (MSG) doses of 1.5, 3.0 and 3.15 g/person, which represented a body mass-adjusted dose range of 0.015-0.07 g/kg body weight before a standardized breakfast over 5 days. The study used a rigorous randomized double-blind crossover design that controlled for subjects who had MSG after-tastes. Capsules and specially formulated drinks were used as vehicles for placebo and MSG treatments. Subjects mostly had no responses to placebo (86%) and MSG (85%) treatments. Sensations, previously attributed to MSG, did not occur at a significantly higher rate than did those elicited by placebo treatment. A significant (P < 0.05) negative correlation between MSG dose and after-effects was found. The profound effect of food in negating the effects of large MSG doses was demonstrated. The common practice of extrapolating food-free experimental results to 'in use' situations was called into question. An exhaustive review of previous methodologies identified the strong taste of MSG as the factor invalidating most 'blind' and 'double-blind' claims by previous researchers. The present study led to the conclusion that 'Chinese Restaurant Syndrome' is an anecdote applied to a variety of postprandial illnesses; rigorous and realistic scientific evidence linking the syndrome to MSG could not be found.

Delayed pharyngoesophageal perforation: a complication of anterior spine surgery.

Stabilization of the cervical spine is often accomplished via an anterior cervical approach. Bone grafts and/or plates and screws are used to achieve stabilization. Injuries to the pharynx and esophagus are known complications in anterior exposure of the cervical spine. These injuries are manifest in the early postoperative period. Reports of late perforations are very rare. We present four cases of delayed injury to the pharynx and esophagus that resulted in abscess or fistula. We postulate that graft displacement with resulting erosion was responsible for these serious complications. Postoperative odynophagia in patients who undergo anterior cervical fusion warrants evaluation of the bone graft location. Early surgical intervention and repair may decrease prolonged morbidity in these patients.

Neural network classification of myoelectric signal for prosthesis control.

An alternate approach to deriving control for multidegree of freedom prosthetic arms is considered. By analyzing a single-channel myoelectric signal (MES), we can extract information that can be used to identify different contraction patterns in the upper arm. These contraction patterns are generated by subjects without previous training and are naturally associated with specific functions. Using a set of normalized MES spectral features, we can identify contraction patterns for four arm functions, specifically extension and flexion of the elbow and pronation and supination of the forearm. Performing identification independent of signal power is advantageous because this can then be used as a means for deriving proportional rate control for a prosthesis. An artificial neural network implementation is applied in the classification task. By using three single-layer perceptron networks, the MES is classified, with the spectral representations as input features. Trials performed on five subjects with normal limbs resulted in an average classification performance level of 85% for the four functions.

The application of neural networks to myoelectric signal analysis: a preliminary study.

Two neural network implementations are applied to myoelectric signal (MES) analysis tasks. The motivation behind this research is to explore more reliable methods of deriving control for multidegree of freedom arm prostheses. A discrete Hopfield network is used to calculate the time series parameters for a moving average MES model. It is demonstrated that the Hopfield network is capable of generating the same time series parameters as those produced by the conventional sequential least squares (SLS) algorithm. Furthermore, it can be extended to applications utilizing larger amounts of data, and possibly to higher order time series models, without significant degradation in computational efficiency. The second neural network implementation involves using a two-layer perceptron for classifying a single site MES based on two features, specifically the first time series parameter, and the signal power. Using these features, the perceptron is trained to distinguish between four separate arm functions. The two-dimensional decision boundaries used by the perceptron classifier are delineated. It is also demonstrated that the perceptron is able to rapidly compensate for variations when new data are incorporated into the training set. This adaptive quality suggests that perceptrons may provide a useful tool for future MES analysis.

Approach for oxygenation of the newborn with airway obstruction due to a cervical mass.

Large congenital cervical neck masses present major difficulties in management of the neonatal airway at delivery and in the perinatal period. With ultrasound, these lesions can be predicted prenatally. An airway treatment plan can then be formulated and modified in relation to the airway presentation at birth. We describe a case of a massive cervical-mediastinal teratoma and our management plan. Preparation involved a multidisciplinary approach including endoscopy to secure the airway while the neonate remained on fetal circulation and an extracorporeal membrane oxygenation system was available. Once the infant's condition was stable, a cervical approach with resection of the massive teratoma with mediastinal dissection without sternotomy was successful. A differential diagnosis of cervical neck masses and review of cervical teratomas is presented.

Myoelectric signal analysis using neural networks.

It is shown that the capacity of a discrete Hopfield network for functional minimization allows it to extract the time-series parameters from a myoelectric signal (MES) at a faster rate than the previously used SLS algorithm. With a two-dimensional signal space consisting of one of the parameters and the signal power, a two-layer perceptron trained using back-propagation has been used to classify MES signals from different types of muscular contractions. The results suggest that neural networks may be suitable for MES analysis tasks and that further research in this direction is warranted.

Diagnosis and treatment of congenital choanal atresia.

Choanal atresia is the developmental failure of the posterior nasal cavity to communicate with the nasopharynx. Because of its rare incidence, otolaryngologists have limited experience in treating this unusual congenital anomaly. We report the case of a seventeen year old female with bilateral membrano-osseous choanal atresia who miraculously survived her anomaly and was not definitively diagnosed and surgically treated until she was seventeen. Definitive surgical correction of choanal atresia is challenging. The various methods advocated include the transnasal, transpalatal, trans-septal and sublabial approaches. We will discuss the various treatment options and relate our own personal experience in the management of choanal atresia. A review of the literature on the various modalities available for surgery, stenting and rehabilitation will be discussed also.

Light-wire treatment of a Class II, division 1 subdivision malocclusion. An American Board of Orthodontics case report.

A case report of a Class II, Division 1 subdivision malocclusion with a deep overbite and a marked overjet is presented. The patient was a 14-year-old boy with the potential for continued growth. The lip positions imposed by the teeth and the facial skeleton increased the labioversion of the maxillary incisors. A Begg light-wire appliance was used throughout the course of treatment. Since the maxilla and mandible were retrognathic to the cranial base, the malocclusion was treated by nonextraction methods.

The elimination of tritiated doxycycline in normal subjects and in patients with severely impaired renal function.

Tritiated doxycycline was administered to four normals, four patients with renal failure interdialysis, and three patients in renal failure who were not on dialysis. Elimination was followed by collection of urine and feces up to eight days. It was demonstrated that renal failure reduced the urinary excretion of doxycycline. In normal individuals the total of 86% of the radioactivity was eliminated in five days, half in the urine and half in the feces. In patients, with renal failure on dialysis, 32% of the radioactivity was eliminated in that time, 9.3% in the urine and 23% in the feces. In renal failure patients not on dialysis 49% was eliminated in that time, 4% in the urine and 45% in the feces; when followed up to eight days a total of almost 70% of the radioactivity was eliminated and the increase elimination was accounted for by fecal elimination such that 64% was eliminated in the feces and 5% in the urine. The disappearance from the plasma compartment in all three groups was similar. Thus, although the plasma half-life of doxycycline is not significantly prolonged in renal failure, it appears likely that the drug is taken up into a compartment from which it may slowly be eliminated and when followed for a continual period of time a significant percentage can be recovered from the feces. There remains however, up to 30% of the administered dose which was not recovered and it must be assumed that a significant per cent of doxycycline would accumulate in a compartment, as yet unidentified, in patients with renal failure.