Associations between CD36 gene polymorphisms, fat tolerance and oral fat preference in a young-adult population.

BACKGROUND/OBJECTIVES: CD36 is known to be an orosensory receptor for dietary long-chain fatty acids, as well as being involved in the chemosensory mechanisms within the human gut. Recent data have demonstrated an association between CD36 single-nucleotide polymorphisms (SNPs) and lipid consumption behaviours in humans. This study aimed to test for associations between CD36 SNPs and response to a high-fat meal in a young healthy Australian cohort. Secondary associations were tested between CD36 gene variants and fasting lipid parameters, body composition, cardiovascular disease (CVD) risk factors and measures of oral fat preference. SUBJECTS/METHODS: Two SNPs (rs1527479 and rs1984112) were assessed for associations with response to a 75 g saturated fat oral fat tolerance test (OFTT), whole-body substrate oxidation, fasting plasma lipids, CVD risk factors and self-reported habitual diet questionnaires. Genotyping was performed using real-time polymerase chain reaction. RESULTS: Cross-sectional data were collected on 56 individuals (28 m, 28 f; 24.9±3.3 years), with 42 completing participation in a high-fat OFTT. No genotypic associations were evident in anthropometric data or self-reported fat preference measures. AA SNP carriers at rs1984112 exhibited significantly elevated fasting triglyceride when compared with non-carriers (P=0.024). This group also tended to have an elevated response to a high-fat meal (P=0.078). CONCLUSIONS: Although these data show the potential pleiotropic influence of CD36 SNP rs1984112 on lipoprotein accumulation in a young healthy cohort, further assessment in a larger cohort is warranted.

Cardiorespiratory responses during functional electrical stimulation cycling and electrical stimulation isometric exercise.

STUDY DESIGN: Prospective experimental. OBJECTIVES: To compare the cardiorespiratory responses with electrical stimulation (ES) producing either dynamic leg cycling or intermittent isometric leg contractions using the same ES protocol. SETTING: Sydney, Australia. METHODS: Eight paraplegics (T4-T11) performed ES exercise sessions on two separate days. On day 1, cardiorespiratory responses were measured during 5 min of rest followed by 35 min of cycling, and finally 15 min of intermittent isometric exercise using the same ES parameters. On the second day, after 5 min of rest, 35 min of isometric exercise was performed followed by 15 min of cycling. RESULTS: There were no significant differences during the first 35 min of exercise on each day comparing the two modes of exercise for average rate of oxygen consumption (cycling, 534±128 ml min(-1); isometric 558±146 ml min(-1); P=0.451), the average heart rate (cycling, 93±15 b.p.m.; isometric 95±17 b.p.m.; P=0.264) or minute ventilation (cycling, 23.0±6.5 l min(-1); isometric 23.8±6.7 l min(-1); P=0.655). In addition, there were no significant differences between exercise modes for any peak cardiorespiratory values recorded during the initial 35 min of exercise or the following 15 min crossover exercise phase. CONCLUSION: The current data found that intermittent ES leg isometric exercise elicited a similar cardiorespiratory response compared with functional ES leg cycling, suggesting it should be investigated as a viable alternative intervention for increasing whole body metabolic rate during sustained exercise training sessions for individuals with paralyzed muscles.

Spray characterization of thermal fogging equipment typically used in vector control.

Droplet size spectra from different sprayers used to generate insecticide-laden fogs for controlling flying insects were measured by a laser diffraction instrument and Teflon-coated slides. The objectives of this work were to present not only information on spray-system droplet size generated by different sprayers, but to compare methodologies by which other similar systems can be evaluated and give applicators sprayer-system performance data. Data from 45 replicated spray tests, comprising 11 sprayers and 5 pesticides, showed a wide range in the droplet size spectra produced. The volume median diameter measurements ranged from 2.6 to 75.5 microm for diesel-diluted sprays and from 27.9 to 59.9 microm for water-diluted sprays. Similarly, the percent volume <20 microm ranged between 12.0-100% and 8.5-30.7%, for diesel- and water-diluted sprays, respectively. The droplet sizes measured by the swinging slide and laser diffraction methods were not consistent. The information presented aids users in sprayer selection and operation to produce the specific droplet size spectra required for a particular application.

Characterization of truck-mounted atomization equipment typically used in vector control.

The control of medically important arthropod vectors of human and animal disease is a high priority for both public health and military officials. Because droplet size of pesticide spray material is a critical factor affecting vector control applications, the droplet-size spectra produced by 11 sprayers and 3 spray formulations were evaluated. Droplet-size spectra were measured by a laser diffraction instrument, a hot-wire system, and rotating slides. There were considerable differences in the droplet-size spectra produced by the different sprayers tested. The volume median diameter (Dv0.5) for the water-based sprays ranged from 4.7 to 211 microm, depending on the sprayer, and the percent of spray volume contained in droplets less than 20 microm (%vol <20 microm) ranged between 0.5% and 98.9%. The Dv0.5 measurements for the oil-based sprays ranged from 9.4 to 125.3 microm and the %vol <20 microm ranged between 2.4% and 97.9%. The correlations between the Dv0.5 measured by the laser system (Dv0.5-laser) and the mass median diameter, Sauter diameter, and Dv0.5 measured by the AIMS probe were all significant. Generally, the slide Dv0.5s were numerically similar to the Dv0.5 from the laser system and the Sauter diameter from the Army Insecticide Measuring System probe. There was less consistent agreement between the % <32 microm values obtained from the slides and those from the other 2 samplers. The information presented can be used by applicators to select the sprayer that produces the droplet-size spectra needed for their particular application situation.

Operational note indoor low-volume spray trials: handheld equipment evaluation.

Four handheld aerosol-mist generators and 1 thermal fog generator were evaluated initially for their ability to deliver low flow rates (< or = 5 ml/min) of resmethrin insecticide. Two generators, the London Fog Eliminator and Clarke Pl, were then selected from that group to conduct a treatment of a block of 16 residences (4 x 4 grid) vs. direct treatment of individual residences to determine the most efficacious method of treating a group of small dwellings or a village. Data are presented on droplet density, volume median diameter, and mortality of caged mosquitoes treated with the P1 and Eliminator in residences treated as a group; and mortality for caged Aedes aegypti L. in residences treated individually with the P1 at various flow control settings and spray-on times.

Aerobic work capacity in elite wheelchair athletes: a cross-sectional analysis.

OBJECTIVE: To give a descriptive analysis of aerobic capacity among elite wheelchair athletes in association with various personal characteristics and sprint or anaerobic capacity. DESIGN: Sixty-eight wheelchair athletes who participated in the World Games and Championships for the Disabled were included. Parameters for aerobic capacity were evaluated in a standardized wheelchair exercise test on a computer-controlled wheelchair ergometer at the games. The ergometer setting was individually tuned according to standardized procedures. RESULTS: Mean maximum power output was 72.2 +/- 36.7 W. Peak oxygen uptake showed similar strong variations among different subject groups. High values were seen in a group of six subjects with amputations. Results stressed that, apart from sex, functionality and training status had a strong influence on aerobic capacity. Anaerobic and aerobic capacity were strongly associated. CONCLUSIONS: Functionality, training status, and sex are important determinants of aerobic capacity. The functional classification used at international sports events is represented in the data, and further study into the possible contribution of standardized exercise tests within the issue of classification must be considered. The use of standardized exercise tests for the evaluation of training and for rehabilitation progress must be advocated, with power output being an important outcome measure at the level of ability, whereas oxygen uptake represents outcome at the level of organ systems.

Human skeletal sarcoplasmic reticulum Ca2+ uptake and muscle function with aging and strength training.

This study investigated the adaptations of skeletal muscle sarcoplasmic reticulum (SR) Ca2+ uptake, relaxation, and fiber types in young (YW) and elderly women (EW) to high-resistance training. Seventeen YW (18-32 yr) and 11 EW (64-79 yr) were assessed for 1) electrically evoked relaxation time and rate of the quadriceps femoris; and 2) maximal rates of SR Ca2+ uptake and Ca2+-ATPase activity and relative fiber-type areas, analyzed from muscle biopsies of the vastus lateralis. EW had significantly slower relaxation rates and times, decreased SR Ca2+ uptake and Ca2+-ATPase activity, and a larger relative type I fiber area than did YW. A subgroup of 9 young (YWT) and 10 elderly women (EWT) performed 12 wk of high-resistance training (8 repetition maximum) of the quadriceps and underwent identical testing procedures pre- and posttraining. EWT significantly increased their SR Ca2+ uptake and Ca2+-ATPase activity in response to training but showed no alterations in speed of relaxation or relative fiber-type areas. In YWT none of the variables was altered after resistance training. These findings suggest that 1) a reduced SR Ca2+ uptake in skeletal muscle of elderly women was partially reversed with resistance training and 2) SR Ca2+ uptake in the vastus lateralis was not the rate-limiting mechanism for the slowing of relaxation measured from electrically evoked quadriceps muscle of elderly women.

Energy cost of sport rock climbing in elite performers.

OBJECTIVES: To assess oxygen uptake (VO2), blood lactate concentration ([La(b)]), and heart rate (HR) response during indoor and outdoor sport climbing. METHODS: Seven climbers aged 25 (SE 1) years, with a personal best ascent without preview or fall (on sight) ranging from 6b to 7a were assessed using an indoor vertical treadmill with artificial rock hand/foot holds and a discontinuous protocol with climbing velocity incremented until voluntary fatigue. On a separate occasion the subjects performed a 23.4 m outdoor rock climb graded 5c and taking 7 min 36 s (SE 33 s) to complete. Cardiorespiratory parameters were measured using a telemetry system and [La(b)] collected at rest and after climbing. RESULTS: Indoor climbing elicited a peak oxygen uptake (VO2climb-peak) and peak HR (HRpeak) of 43.8 (SE 2.2) ml/kg/min and 190 (SE 4) bpm, respectively and increased blood lactate concentration [La(b)] from 1.4 (0.1) to 10.2 (0.6) mmol/l (p < 0.05). During outdoor climbing VO2 and HR increased to about 75% and 83% of VO2climb-peak and HRpeak, respectively. [La(b)] increased from 1.3 (0.1) at rest to 4.5 mmol/l (p < 0.05) at 2 min 32 s (8 s) after completion of the climb. CONCLUSIONS: The results suggest that for elite climbers outdoor sport rock climbs of five to 10 minutes' duration and moderate difficulty require a significant portion of the VO2climb-peak. The higher HR and VO2 for outdoor climbing and the increased [La(b)] could be the result of repeated isometric contractions, particularly from the arm and forearm muscles.

Propulsion technique and anaerobic work capacity in elite wheelchair athletes: cross-sectional analysis.

Wheelchair sports and daily manual wheelchair propulsion are dominated by frequent short-term power demands. The purpose of the current cross-sectional study was to determine the variation in propulsion technique in association with sprint power production among elite wheelchair athletes. Therefore, 67 wheelchair athletes (different impairments; 17 female and 50 male athletes; age, 29.1+/-7 yr; body weight, 60.7+/-11.8 kg; training hours, 12.9+/-6.4 h x wk(-1); VO2 peak, 1.7+/-0.7 liter x min(-1); aerobic power output, 72.2+/-36.7 W) were studied during the World Championships and Games for the Disabled in Assen (1990) on propulsion technique and anaerobic work capacity in a 30-s sprint test on a computer controlled wheelchair ergometer. Mean power output (P30) (97+/-45.8 W; range, 8.3-195.3 W) and heart rate (158.6+/-23.6 b x min(-1)) were highly variable and seemed associated with impairment level: track athletes, classified in four different functional classes, showed a class-related P30 of 23, 68, 100, and 138 W for the male athletes (n=38). Sprint power relative to body weight varied between 0.36 W X kg BW(-1)+/-0.04 and 1.85 W X kg BW(-1)+/-0.43 for the different subject groups. Propulsion technique in terms of forces applied to the rim and timing showed significant differences between subject groups for the majority of parameters studied. Apart from the mediolateral force and the negative dip at the start of the push phase, the technique parameters were significantly related to power production. Fraction effective force, the ratio between the total force vector and the effective force applied to the hand rim, appeared low on average (especially for subjects with cerebral palsy and those with a high spinal lesion) but showed a significant correlation with power output (r=0.5). In general, propulsion technique parameters were related to both performance and functionality. The number of training hours showed a small but significant relation with peak power (r=0.31), peak torque (r=0.4), the amount of work per push (r=0.41) and the total force vector (r=0.31), stressing the role of training status, next to disability, as important mediating factor in both propulsion technique as well as performance capacity. No association between training hours and fraction effective force was seen. It can be concluded that propulsion technique and performance parameters are highly variable among wheelchair athletes. Also, propulsion technique is strongly associated with functionality and training hours and does clearly relate to performance. The current results on technique and performance and their possible causal relationship, but also with impairment and sports discipline, must be further substantiated in a longitudinal study design.

Flit-gun sprayer characteristics.

Six flit-gun sprayers were tested for possible use in mosquito adulticide programs where inexpensive nonmotorized application technology may be required. An analysis of variance for differences in droplets < or = 24 microns (mu), droplets > or = 48 mu, droplets/cm2, volume median diameters, and mosquito mortality is provided. As shown by these data, good results can be achieved with this equipment.

Flit-gun sprayer characteristics / Atomizadores de compresión activados a mano

Six flit-gun sprayers were tested for possible use in mosquito adulticide programs where inexpensive nonmotorized application technology may be required. An analysis of variance for differences in droplets ≤ 24 microns (µ), droplets ≥ 48 µ, droplets/cm2, volume median diameters, and mosquito mortality is provided. As shown by these data, good results can be achieved with this equipment.

Se pusieron a prueba seis atomizadores de compresión activados a mano a fin de evaluar su utilidad para programas de exterminio de mosquitos adultos en que se necesiten tecnologías no motorizadas de bajo costo. Se hace un análisis de la varianza en cuanto a partículas ≤ 24 y ≥ 48 micras (µ), partículas/cm2, diámetro del volumen mediano, y número de mosquitos muertos. Los datos confirman que pueden obtenerse buenos resultados con aparatos de este tipo.

Anaerobic work capacity in elite wheelchair athletes.

To study the anaerobic work capacity in wheelchair athletes, 67 elite wheelchair athletes (50 male) were studied in a 30-second sprint test on a computer-controlled wheelchair ergometer during the World Championships and Games for the Disabled in Assen (1990). The experimental set-up (ergometer, protocol) proved to be adequate in terms of power output (P30, P5) velocity and heart rate. Male and female athletes were comparable with respect to personal characteristics (age, body weight, training hours). Track athletes (classified in 4 different functional classes) showed a class-related mean power output (P30: mean power produced during the 30-second sprint period) of 23, 68, 100, and 138 W for the male athletes (n = 38) and 38, 77, and 76 W for females in the upper three classes (n = 10). Sprint power was low for the group of subjects with cerebral palsy (35 W; mixed, n = 6) and relatively high for the amputee group (121 W; mixed, n = 6), female basketball players (81 W; n = 5), and two male field athletes (110 W). Significant differences between male and female athletes were found for P30 and P5 (highest mean power output over any of the six 5-second periods). As was to be expected, mean maximum heart rate in the sprint test varied significantly between the track groups from 112 (high lesion group) to 171 beats/minute(-1) (low lesion group) but not for both genders. The lower P30 in the T1 and T2 groups must be explained not only by the reduced functional muscle mass and impaired coordination but also by phenomena of cardiovascular dysfunction. Based on the performance parameters, the functional classification of the track athletes into four groups seems adequate. P30 was significantly associated with the personal characteristics of gender and hours of training. A significant correlation was found between P30 and sprint performance times for 200 meters (r = -0.79). No correlation was found between either of the forms of power output and the marathon times. Anaerobic wheelchair work capacity can be adequately studied with the 30-second sprint test that was used in this study. Anaerobic work capacity is highly variable among elite wheelchair athletes with different disabilities and from different sports disciplines and appeared quite strongly influenced by functionality, hours of training, and gender.

Impaired calcium pump function does not slow relaxation in human skeletal muscle after prolonged exercise.

This study examined the effects of prolonged exercise on human quadriceps muscle contractile function and homogenate sarcoplasmic reticulum Ca2+ uptake and Ca2+-adenosinetriphosphatase activity. Ten untrained men cycled at 75 +/- 2% (SE) peak oxygen consumption until exhaustion. Biopsies were taken from the right vastus lateralis muscle at rest, exhaustion, and 20 and 60 min postexercise. Peak tension and half relaxation time of the left quadriceps muscle were measured during electrically evoked twitch and tetanic contractions and a maximal voluntary isometric contraction at rest, exhaustion, and 10, 20, and 60 min postexercise. At exhaustion, homogenate Ca2+ uptake and Ca2+ adenosinetriphosphatase activity were reduced by 17 +/- 4 and 21 +/- 5%, respectively, and remained depressed after 60 min recovery (P

An electrostatic backpack sprayer: potential for mosquito control.

A Southwest Electrostatic Sprayers, Inc., nozzle was configured to a Hudson PortaPak backpack. A test was run to compare deposition of BVA no. 13 oil by the electrostatic nozzle to a standard nonelectrostatic nozzle as collected by Teflon slides. Results indicate that 100% greater deposition occurred with the electrostatic nozzle.

Emergency control of Aedes aegypti in the Dominican Republic using the Scorpion 20 ULV forced-air generator.

In an effort to develop a more effective measure for use in emergency control of the dengue vector Aedes aegypti. applications of a combination of a larvicide (Bacillus thuringiensis israelensis [B.t.i.]) and an adulticide (permethrin) were made using a truck-mounted forced-air generator (Scorpion 20) and evaluated in the Dominican Republic. This method has the potential to simultaneously control adults and larvae. In bioassay cages placed in household water containers at the time of application, larval mortalities were 95.1 and 100% for 2 application rates of permethrin mixed with B.t.i. Adult mortalities were not as impressive, probably because of resistance to permethrin. Higher adult mortality in caged specimens (78.5%) and a substantial reduction in the natural population (68.4%) of Ae. aegypti were obtained following a 2.1-g AI/ha application of deltamethrin alone.

Malathion resistance in mosquitoes from Charleston and Georgetown counties of coastal South Carolina.

Susceptibility tests were conducted using the World Health Organization diagnostic test procedure on strains of Aedes taeniorhynchus, Aedes sollicitans, Aedes vexans, and Culex nigripalpus collected from several localities in Charleston and Georgetown counties of South Carolina. Aedes taeniorhynchus was resistant to malathion (mortality 1.0-54.4%) but not to propoxur, permethrin, or fenitrothion. There also were indications that Ae. sollicitans and Cx. nigripalpus were resistant to malathion, but to a lesser extent than Ae. taeniorhynchus (mortalities: 72.1-81.0%, and 46.2%, respectively). Aedes vexans was susceptible to malathion (mortality 98.6%). In field tests using ULV application of malathion and field-collected Ae. taeniorhynchus, and susceptible Ae. aegypti and Ae. taeniorhynchus, a noticeably lower mortality also was obtained in the wild mosquitoes.

First report of Ixodes (Ixodes) minor Neumann (Acari: Ixodidae) from South Carolina.

Previous reports from the literature have indicated the northernmost range of extension of Ixodes minor Neumann to be southern Georgia with the greatest number of collections having been made in the coastal regions of that state. An unpublished record in the U.S. National Tick Collection indicated that I. minor had been collected as far north as South Island, Georgetown County, S.C., as early as 1933. I. minor was collected on three separate occasions in Charleston County, S.C., between October 1990 and February 1991, thus verifying the northern extension of this tick's range and the probable existence of a stable population on the coast of South Carolina. The roof rat (Rattus rattus) is reported for the first time serving as a host for I. minor.

Insecticide susceptibility of Aedes aegypti from Santo Domingo, Dominican Republic.

The insecticide susceptibility of Aedes aegypti adults and larvae from Santo Domingo, Dominican Republic, was investigated using World Health Organization standard procedures. A field strain was more resistant to insecticides than a colony strain that originated from the same place. Larvae produced from ovitrap-collected eggs were resistant to temephos (78.2% mortality on exposure to 0.025 mg/liter). Mortality rates after exposure of adults to discriminating concentrations showed that wild populations were resistant to DDT, malathion, propoxur, permethrin and deltamethrin. The problem of resistance was considered serious enough to warrant consideration of control measures other than the use of chemicals.

Baseline data on Aedes aegypti populations in Santo Domingo, Dominican Republic.

Baseline field studies were conducted from April 1987 to July 1988 on Aedes aegypti in Santo Domingo, an endemic area for dengue fever. Premise, container and Breteau indices were measured in one treated area and 2 nearby control areas. These indices averaged 69.6, 46.3 and 142.1, respectively. The principal larval habitats of Ae. aegypti were 208-liter (55-gal) concrete-lined drums. The estimated daily adult production was approximately 60 per house. Adult mosquito populations were monitored using oviposition traps and by sweep net collections. There was no correlation between adult abundance and the larval indices. Monitoring the natural adult densities was more efficient for evaluating the impact of ULV malathion application than the use of standard bioassay procedures.