Heat and moisture exchangers as a treatment option in the post-operative rehabilitation of laryngectomized patients

A multi-institutional, prospective clinical study was undertaken to investigate whether the use of a heat and moisture exchanger (HME) in the period following total laryngectomy could prevent the development or reduce the severity of respiratory symptoms. Fifty-nine patients from three hospitals were provided with HMEs, either immediately post-surgery or, in the case of post-surgical radiotherapy, upon completion of the radiotherapy. For the total sample (n= 59) statistically significant improvements over time (between 3 and 6 months) could be found in forced expectoration (P < 0.05), in the perceived voice quality (P < 0.001), social anxiety (P < 0.001), social interactions (P < 0.001) and in feelings of anxiety and depression (P < 0.05). Repeated measures analysis of variance indicated statistically significant group differences over time in forced expectoration and stoma cleaning (P < 0.05). No statistically significant differences over time were noted between the regular and non(regular) HME user groups in voice quality or in various aspects of daily living.     

Motor unit potential contribution to surface electromyography

The background of the bioelectric activity of muscle recorded from the surface of the skin (surface electromyography) in terms of the representation of single motor units of the underlying muscle(s) is not very well documented or understood. An insight into the composition of an electromyogram is essential for the proper interpretation of one of the most widely applied electrophysiological techniques. In the present paper, a study of the contribution of single motor unit potentials to the surface electromyogram is presented. To this end, the decline of different components of the motor unit potential with depth of the motor unit is quantified. Experimentally, the action potentials from motor units at several positions in the muscle were recorded by 30 skin surface electrodes. Simultaneous use of scanning electromyography provided information about the actual position and size of the motor unit. Observed linear log–log relationships between motor unit potential magnitudes and distance indicated the usefulness of a power function to describe the motor unit potential's dependence on recording distance. It is shown that different specific surface motor unit potential characteristics fall off differently with depth. The magnitude–distance relationship is shown to be dependent on the recording configuration (unipolar vs. bipolar recording, including the inter-electrode distance) and the chosen motor unit potential parameter (negative peak amplitude, positive peak amplitude and area).     

Effects of cholestyramine on gallbladder and gastric emptying in obese and lean subjects

Abstract. Gallbladder stasis is frequent in obese subjects and may contribute to their increased risk for gallstone formation. The bile salt sequestrant cholestyramine acutely enhances postprandial gallbladder emptying in lean subjects, through dis-inhibition of a negative feedback between intraluminal bile salts and CCK release. In this study the effect of cholestyramine on both gallbladder and gastric antrum dynamics were studied by realtime ultrasonography in 12 obese and 15 lean subjects. For the acute study, on different days, subjects ingested a liquid meal (two egg yolks plus water 200 mL, 50 kJ) or a meal with 4g cholestyramine. Gallbladder emptying was impaired in obese patients who had significantly larger fasting gallbladder volume (39.4 ± 6.9 vs. 21.6 ± l.7mL, P <0.02), larger residual volume (12.3 ± 1.8 vs. 4.0 ± 0.5ml, P < 0.0006) and slower emptying time ( T /2: 33 ± 2 vs. 21 ± 2 min, P < 0.05) than lean subjects. Integrated antral emptying was also less in obese than lean subjects (5521 ± 578 vs. 7908 ± 491 % 120min^-1, P <0.02). Cholestyramine enhanced postprandial gallbladder emptying in both obese and lean subjects. Gastric emptying was delayed with cholestyramine in lean but not obese subjects. For the chronic study, after 1 month therapy with cholestyramine (4 g every 2 days), the motility tests were repeated in nine obese subjects. Gallbladder and gastric responses to a test meal, with or without cholestyramine, were preserved. We conclude that both gallbladder and antral emptying of a liquid test meal are impaired in obese subjects. Gallbladder emptying improves after acute administration of a low dose cholestyramine with test meal. This effect is sustained after 1 month treatment with a low dose of cholestyramine and does not interfere with gastric emptying of obese patients. Cholestyramine may improve gallbladder hypomotility in obese people.     

Delayed sleep phase syndrome: A placebo-controlled cross-over study on the effects of melatonin administered five hours before the individual dim light melatonin onset

In a double-blind placebo-controlled cross-over study, 30 patients with Delayed Sleep Phase Syndrome (DSPS) were included, of whom 25 finished the study. Melatonin 5 mg was administered during two weeks in a double-blind setting and two weeks in an open setting successively or interrupted by two weeks of placebo. The study's impact was assessed by measurements of the 24-h curves of endogenous melatonin production and rectal temperature (n=14), polysomnography (n=22), actigraphy (n=13), sleep log (n=22), and subjective sleep quality (n=25). Mean dim light melatonin onset (DLMO) (±SD), before treatment, occurred at 23.17 hours (±138 min). Melatonin was administered five hours before the individual DLMO. After treatment, the onset of the nocturnal melatonin profile was significantly advanced by approximately 1.5 hour. Body temperature trough did not advance significantly. During melatonin use, actigraphy showed a significant advance of sleep onset and polysomnography, a significant decreased sleep latency. Sleep architecture was not influenced. During melatonin treatment patients felt significantly more refreshed in the morning. These results show that analysis of DLMO of patients suffering from DSPS is important both for diagnosis and therapy. These results are discussed in terms of the biochemistry of the pineal.