Efficacy of radiofrequency volumetric tissue reduction of the soft palate in the treatment of snoring.

Traditional surgery for snoring often leads to intolerable postoperative pain. A new surgical treatment, radiofrequency volumetric tissue reduction (RVTR) of the soft palate, was carried out and its effect and safety in the management of snoring were evaluated. Thirty-two patients received a single treatment of RVTR with a mean follow-up period of 4.5 months. All patients were assessed by a questionnaire using the Snore Outcomes Survey (SOS) and the Epworth Sleepiness Scale (ESS). Postoperative pain, speech and swallowing disturbances were also evaluated. The postoperative scores of SOS and ESS all significantly improved (p<0.05). Postoperative pain, speech and swallowing disturbances were all mild 1-3 days after treatment. With the success of treatment defined as a postoperative snoring index (SI) of <3 or a reduction of the SI by >5 points by the visual analogue scale, the success rate was 81.3% in patients with a respiratory disturbance index (RDI) of <20, and 50% in those with an RDI of >20. We conclude that RVTR of the soft palate is an effective treatment for snoring, resulting in only mild postoperative discomfort. A patient whose RDI was <20 had a higher success rate with a single RVTR treatment.

Comparative genomics of the eukaryotes.

A comparative analysis of the genomes of Drosophila melanogaster, Caenorhabditis elegans, and Saccharomyces cerevisiae-and the proteins they are predicted to encode-was undertaken in the context of cellular, developmental, and evolutionary processes. The nonredundant protein sets of flies and worms are similar in size and are only twice that of yeast, but different gene families are expanded in each genome, and the multidomain proteins and signaling pathways of the fly and worm are far more complex than those of yeast. The fly has orthologs to 177 of the 289 human disease genes examined and provides the foundation for rapid analysis of some of the basic processes involved in human disease.

Radical resection for naso-lacrimal duct tumour.

Naso-lacrimal duct tumours are uncommon and present with epiphora and swelling. Since the naso-lacrimal duct is embedded in bone for the majority of its anatomical length, the late presentation of proptosis is due to orbital extension of the tumour. Radical surgical treatment is necessary to establish clear margins and facilitate reconstruction.

Effect of histamine treatment on dopamine tachyphylaxis of canine tracheal smooth muscle.

In order to understand how histamine-sensitized airways may react to exogenous dopamine, we investigated the effect of histamine treatment on the dopamine-induced contractions of canine tracheal smooth muscle. The results showed that preconstricting muscle strips with histamine (10(-6) M to 10(-4) M) not only increased the amplitude of dopamine-induced contraction, but also lowered the concentration of dopamine required to provoke contraction from 10(-4) M to 10(-6) M. In muscle strips desensitized by repeated challenges of 10(-3) M dopamine, a 15-min treatment with 10(-4) M histamine transiently restored the response. The restored contractions were decreased by the dopaminergic antagonist, domperidone, and the alpha 2-adrenoceptor antagonist, yohimbine, and increased by the beta 1-adrenoceptor antagonist, atenolol. It is concluded that in addition to its role in mediating airway constriction, histamine can promote and enhance the contractile response of canine tracheal smooth muscle to dopamine. Histamine treatment restored the dopamine response of desensitized tracheal muscle with resensitization of the adrenoceptors.

The effect of exogenous dopamine on canine trachea.

The response of canine trachea to exogenous dopamine was studied in vivo. Pentobarbital-anesthetized dogs were treated with dopamine through i.v. injection and i.v. infusion. The dopamine-induced constriction of the trachea was evaluated from changes in the intraluminal pressure of a semi-isolated section. The respiratory flow was monitored with a pneumotachograph. Dopamine administered through i.v. infusion (4-12 micrograms/kg/min) increased the blood pressure but decreased the respiratory rate and flow. At infusion rate of 8 micrograms/kg/min or higher, the intraluminal pressure went up gradually and recovered at the end of infusion. Bolus i.v., injection of dopamine (10-100 micrograms/kg) increased the blood pressure and the intraluminal pressure of trachea, but decreased the respiratory rate and flow. The pressure change in the tracheal tube lasted 2 to 3 minutes. These results demonstrate that, in addition to its well known effect on raising blood pressure, exogenous dopamine can induce transient constriction of the trachea in living animals. The constriction is accompanied by changes of respiratory pattern.

The excitatory effect of dopamine on isolated canine tracheal smooth muscle.

The effect of exogenous dopamine on canine tracheal smooth muscle has been studied in-vitro. Dopamine at concentrations over 10(-5)M induced contractions of tracheal muscle strips and repeated exposures resulted in desensitization (tachyphylaxis) of the muscle. The sensitivity of the response varied dramatically among muscle strips. At lower concentrations, dopamine caused neither muscle relaxation nor inhibition of contractions evoked by 10(-6)M acetylcholine. Both a dopaminergic antagonist, haloperidol (10(-5) and 10(-4)M), and an alpha-adrenoceptor antagonist, phentolamine (10(-7) to 10(-5)M), attenuated the contraction to 10(-3)M dopamine. The beta-adrenoceptor antagonist, propranolol (10(-8) to 10(-6)M), enhanced the contraction. However, the contraction could only be abolished by phentolamine at 10(-4) M. Thus, in canine tracheal smooth muscle, the contractile response to dopamine is predominantly through the activity of alpha-adrenoceptors and the role of dopaminergic receptors is vague. It is suggested that the weakness of the dopamine-induced contraction results from an antagonism between alpha- and beta-adrenoceptor effects and the dopamine tachyphylaxis may reflect a gradually decreased activation of the alpha-adrenoceptor mechanism in comparison with the beta-adrenoceptor mechanism.

Histamine modulates dopamine-induced contraction in canine tracheal smooth muscle.

Since exogenous dopamine is commonly used to treat patients of cardiovascular failure, its action on the histamine-sensitized airways is critical for asthmatic subjects. In this study, in vitro canine airway smooth muscle preparation were employed to investigate whether histamine-treatment affects the responsiveness of airway smooth muscle to dopamine. The results of our study demonstrate that, at dopamine tachyphylaxis of canine tracheal smooth muscle, histamine treatment could recover the contraction to dopamine. In the muscle strips sensitized with histamine, the dopamine-induced contraction was decreased by the antagonist to alpha 2-adrenoceptors and increased by the antagonist to beta 1-adrenoceptors. It is concluded that histamine can modulate the dopamine response of canine tracheal smooth muscle by sensitizing, transiently, multiple receptors in the muscle which are responsible for the contractile response to dopamine.