Stochastically modulated inter-pulse intervals to increase the efficiency of functional electrical stimulation cycling.

INTRODUCTION: Functional electrical stimulation cycling has various health benefits, but the mechanical power output and efficiency are very low compared to volitional muscle activation. Stimulation with variable frequency showed significantly higher power output values in experiments with a knee dynamometer. The aim of the present work was to compare stochastic modulation of inter-pulse interval to constant inter-pulse interval stimulation during functional electrical stimulation cycling. METHODS: Seventeen able-bodied subjects participated (n = 17). Quadriceps and hamstring muscle groups were stimulated with two activation patterns: P1-constant frequency, P2-stochastic inter-pulse interval. Power output was measured on functional electrical stimulation ergometer. RESULTS: Overall, mean power output with the stochastically modulated pattern P2 was lower than with P1 (12.57 ± 3.74 W vs. 11.44 ± 3.81 W, P1 vs. P2, p = 0.022), but no significant differences during the first 30 s and the last 30 s were observed. CONCLUSIONS: This study showed that stimulation strategies that use randomized modulation of inter-pulse intervals can negatively affect power output generation during functional electrical stimulation cycling. To minimise voluntary contractions, power measurement and assessment should be focused on the periods where only the quadriceps are stimulated.

Comparative plasma and milk dispositions, faecal excretion and efficacy of per os ivermectin and pour-on eprinomectin in horses.

The horse milk gains increasing interest as a food product for sensitive consumers, such as children with food allergies or elderly people. We investigated the plasma and milk disposition, faecal excretion and efficacy of per os ivermectin (IVM) and pour-on eprinomectin (EPM) in horses. Ten mares were divided into two groups. The equine paste formulation of IVM and bovine pour-on formulation of EPM were administered orally and topically at dosage of 0.2 and 0.5 mg/kg bodyweight. Blood, milk and faecal samples were analysed using high-performance liquid chromatography. The plasma concentration and persistence of IVM were significantly greater and longer compared with those of EPM. Surprisingly, EPM displayed a much higher disposition rate into milk (AUCmilk/plasma : 0.48) than IVM (AUCmilk/plasma : 0.19). IVM exhibited significantly higher faecal excretion (AUCfaeces : 7148.54 ng·d/g) but shorter faecal persistence (MRTfaeces : 1.17 days) compared with EPM (AUCfaeces : 42.43 ng·d/g and MRTfaeces : 3.29 days). Faecal strongyle egg counts (EPG) were performed before and at weekly intervals after treatment. IVM reduced the EPG by 96-100% for up to 8 weeks, whereas the reduction in the EPM group varied from 78 to 99%. In conclusion, due to the relatively low excretion in milk, EPM and IVM may be used safely in lactating mares if their milk is used for human consumption. Nevertheless, much lower plasma and faecal availabilities of EPM could result in subtherapeutic concentrations, which may increase the risk of drug resistance in nematodes after pour-on EPM administration compared with per os IVM.

Plasma disposition and faecal excretion of eprinomectin following topical and subcutaneous administration in non-lactating dairy cattle.

AIMS: To investigate the plasma disposition and faecal excretion of eprinomectin (EPM) in non-lactating dairy cattle following topical and S/C administration. METHODS: Holstein dairy cows, 3.5-5 years-old, were selected 20-25 days after being dried off and were randomly allocated to receive EPM either topically (n=5) or S/C (n=5) at dose rates of 0.5 and 0.2 mg/kg bodyweight, respectively. Heparinised blood and faecal samples were collected at various times between 1 hour and 30 days after treatment, and were analysed for concentrations of EPM using high performance liquid chromatography with a fluorescence detector. RESULTS: The maximum concentration of EPM in plasma (Cmax) and the time to reach Cmax were both greater after S/C administration (59.70 (SD 12.90) ng/mL and 1.30 (SD 0.27) days, respectively) than after topical administration (20.73 (SD 4.04) ng/mL and 4.40 (SD 0.89) days, respectively) (p<0.001). In addition, S/C administration resulted in greater plasma availability (area under the curve; AUC), and a shorter terminal half-life and mean residence time (295.9 (SD 61.47) ng.day/mL; 2.95 (SD 0.74) days and 4.69 (SD 1.01) days, respectively) compared with topical administration (168.2 (SD15.67) ng.day/mL; 4.63 (SD 0.32) days, and 8.23 (SD 0.57) days, respectively) (p<0.01). EPM was detected in faeces between 0.80 (SD 0.45) and 13.6 (SD 4.16) days following S/C administration, and between 1 (SD 0.5) and 20.0 (SD 3.54) days following topical administration. Subcutaneous administration resulted in greater faecal excretion than topical administration, expressed as AUC adjusted for dose (1188.9 (SD 491.64) vs. 311.5 (SD 46.90) ng.day/g; p<0.05). Maximum concentration in faeces was also higher following S/C than topical administration (223.0 (SD 63.96) vs. 99.47 (SD 43.24) ng/g; p<0.01). CONCLUSIONS: Subcutaneous administration of EPM generated higher plasma concentrations and greater plasma availability compared with topical administration in non-lactating cattle. Although the S/C route provides higher faecal concentrations, the longer faecal persistence of EPM following topical administration may result in more persistent efficacy preventing establishment of incoming nematode larvae in cattle.

In vitro effects of colchicine on human erythrocyte membranes: an ESR study.

Colchicine (CC) is an antimitotic and antitubular agent which is currently used in medicine as a drug to treat various diseases. In spite of its widespread use the interaction of this drug with membranes is not yet known clearly. To characterize alterations in membrane molecular dynamics produced by CC, human erythrocytes were spin-labeled with 5-doxylstearic acid (5-DSA) and 16-doxylstearic acid (16-DSA), and membrane fluidity was quantified by measuring the changes in the order parameter (S) which reflects the anisotropy due to restricted motional averaging, correlation time (tau c) representing the spin label tumbling rate in the sample and phase transitions derived from ESR measurements. CC induced significant changes in both order parameter and correlation time at the surface of 5-DSA labeled membrane, but this was not the case at the core of 16-DSA labeled membrane. Order parameter, S and rotational correlation time, tau c, showed a biphasic character in the temperature range of 5-50 degrees C. This fact was used to calculate phase transition temperatures and activation energies of untreated (control) and treated erythrocyte cells with CC.

[Production of polygalacturonase by Bacillus subtilis cultured with waste and residues as carbon sources]. / Bazi atik ve artiklar kullanarak Bacillus subtilis'den poligalakturonaz eldesi.

In the recent study, it was observed that if when the initial pH was 7.0, incubation temperature was 37 degrees C and aeration (150 rpm) was supplied polygalacturonase production by Bacillus subtilis reached to its maximum. Molasses, Vinase and Peach or Apricot pomace were used as carbon sources at differing concentrations and the highest differential rate of enzyme synthesis was detected in the medium prepared with Vinase having a 5% of total sugar content (6.74 delta U/delta O.D.). It also was detected that the waste or residues mentioned above could be used as carbon sources for the polygalacturonase enzyme production by Bacillus subtilis.

[Morphological and physiological properties of Phoma tracheiphila (mal secco) (author's transl)]. / Phoma tracheiphila'nin (uçkurutan) morfolojik ve fizyolojik özellikleri.

The morphological and physiological characteristics of Phoma tracheiphila, the cause of "Mal Secco" in Mediterranian lemons is discussed. The structure and the characteristics of the spore, mycelium and pigment of this fungus were investigated in liquid and solid media. The growth rate was examined in different media with different pH by dry weight determination. The growth curve of P. tracheiphila was first studied in YPG, (pH 5.6) medium in the stationary and shaking culture conditions. During the course of these studies the microscobic observations and measurements were recorded. The results established that in further studies, it will be necessary to incubate P. tracheiphila at least 5 days for its growth. The optimal pH and temperature scale were found between 5.5--6.0 and 20--25 degrees C respectively.