Procainamide therapy, physical performance and energy expenditure in the Schwartz-Jampel syndrome

The effects of procainamide administration were assessed in a 5-yr-old boy with Schwartz-Jampel syndrome (chondrodystrophic myotonia). Without procainamide the resting metabolic rate was found to be significantly higher than in an age-matched control group. With a serum level of 3.8 mg l-1 procainamide a reduction of the resting metabolic rate of 22% was observed, and times needed to climb stairs and to re-open eyes after forceful contraction (blepharospasm) were significantly reduced.     

Gastric emptying of carbohydrate--medium chain triglyceride suspensions at rest.

Nine male volunteers participated in 4 gastric emptying (GE) tests of liquid equicaloric mixtures of CHO (maltodextrins) and MCT of the following composition (% CHO-% MCT): Drink (Dr) 1:70%-30%, Dr2: 80%-20%, Dr3: 90%-10%, Dr4: 100%-0%. GE was measured at rest for 90 min according to the modified double sampling technique. GE rate, expressed as t1/2 (SEM), was 23 (2.3), 24 (1.6), 27 (2.2) and 36 (2.9) min, respectively, from drink 1 to drink 4. Statistical analysis showed that all MCT containing drinks emptied faster than the 100% CHO drink. Two mechanisms may explain this observation: 1) the CHO content and osmolality increases from Dr 1 to Dr 4 (both are regulators of GE); 2) MCT may not inhibit GE as common fat does, due to a better water solubility and absorption in the small intestine, resulting in a decreased duodenal-gastric feedback.     

Dynamic pressure transmission through agarose gels

In biomedical research, agarose gel is widely used in tissue culture systems because it permits growing cells and tissues in a three-dimensional suspension. This is especially important in the application of tissue engineering concepts to cartilage repair because it supports the cartilage phenotype. Mechanical loading, especially compression, plays a fundamental role in the development and repair of cartilage. It would be advantageous to develop a system where cells and tissues could be subjected to compression so that their responses can be studied. There is currently no information on the pressure response of agarose gel when pressure is applied to the gas phase of a culture system. To understand the transmission of pressure through the gel, we set up an apparatus that would mimic an agarose suspension tissue culture system. This consisted of a sealed metal cylinder containing air as well as a layer of agarose submerged in culture medium. Pressure responses were recorded in the air, fluid, gel center, and gel periphery using various frequencies, pressures, gel volumes, and viscosities. Regression analyses show an almost perfect linear relation between gas and gel pressures (r(2) = 0.99987, p < 0.0001, f(x) = 0.9982 x - 0.0286). The pressure transmission was complete and immediate, throughout the range of the applied pressures, frequencies, volumes, and viscosities tested. Applying dynamic pressure to the gas phase results in reproducible pressure in the agarose and, therefore, validates the use of agarose tissue culture systems in studies employing dynamic pressurization in cartilage tissue engineering.     

Increase in fat oxidation on a high-fat diet is accompanied by an increase in triglyceride-derived fatty acid oxidation

The aim of this study is to investigate the mechanism behind the slow increase in fat oxidation on a high-fat diet. Therefore, we determined 24-h substrate oxidation using respiration chambers and the rate of appearance and oxidation of plasma-derived fatty acids in seven healthy nonobese men (age 23 +/- 2 years, height 1.85 +/- 0.03 m, weight 70.4 +/- 2.3 kg, % body fat 13 +/- 1). Before testing, they consumed a low-fat diet (30% fat, 55% carbohydrate) at home for 3 days. Measurements were performed after 1 day consumption of either a low-fat diet (LF), a high-fat diet (HF1, 60% fat, 25% carbohydrate), or a high-fat diet preceded by a glycogen-lowering exercise test (HF1+EX), and after 7 days on a high-fat diet (HF7). After an overnight fast, an infusion of [U-13C]palmitate (0.00806 micromol x min(-1) x kg(-1)) was started and continued for 2 h at rest followed by 1 h of exercise at 50% of maximal power output (Wmax). Whole-body fat oxidation was measured using indirect calorimetry, and plasma-derived fatty acid oxidation was evaluated by measuring breath 13CO2 enrichment and corrected with the acetate recovery factor. Twenty-four-hour fat oxidation gradually increased on the high-fat diet. Both at rest and during exercise, there was no change in rate of appearance of fatty acids and plasma-derived fatty acid oxidation. Triglyceride-derived fatty acid oxidation tended to be higher after 7 days of high-fat diet at rest (P < 0.07). This difference was significant during exercise (P < 0.05). In conclusion, the results from this study suggest that triglyceride-derived fatty acid oxidation (VLDL or intramuscular triglycerides) plays a role in the increase in fat oxidation on a high-fat diet, but plasma-derived fatty acids remain the major source for fat oxidation.     

Infestation of Tunga penetrans in villages near Zomba Central Hospital

An outbreak of Tunga Penetrans (Jigger Flea) infestation affecting a number of villages near to a Central Hospital in Malawi is described. Due to the large number of affected individuals, high parasitic load, and extended duration of infection an alternative to the recommended approach of surgical removal of the flea was required. Benzyl benzoate paint and liquid paraffin had been used in local Primary Healthcare settings previously and topical treatment with antiparasitic agents has been advocated in the literature, particularly for severe infestation. Benzyl benzoate and liquid paraffin were applied topically to four adults with numerous jigger flea burrows, and their progress assessed regularly. After completion of 7 days of treatment patients noted that fleas were dislodging spontaneously, and that embedded parasites had not increased in size to the same extent that untreated fleas had in previous infestations. Following confirmation of the viability of its implementation in a resource-poor setting, this treatment regimen has subsequently been adopted by the local branch of the District Health Office for distribution to infected communities.     

Daily variation in gastric emptying when using the double sampling technique.

The purpose of this study was to establish the intra-individual variation in the rate of gastric emptying (GE) by using the double sampling technique of George. Eight healthy male volunteers, all familiar with gastric intubation and testing, participated in four GE tests, using an isotonic fluid as a test meal. Conditions were kept constant during all four tests, and each test was separated by at least 48 h. The within-subjects coefficient of variation proved to be 29%. The findings demonstrate that, given standard conditions, GE is reproducible from day to day.