Evaluation of possible battlefield suction pumps for the far-forward setting

Medical personnel use suction pumps to clear a patient's airway of mucous, blood, and emesis. Because of size, weight, and durability, many commercially available suction pumps are not suited for battlefield application. The objective of this study was to identify a well-designed suction pump for use in the far forward environment. We report on the performance of seven candidate battlefield suction pumps, all of which are human-powered devices and intended to be carried by medics. Three commercially available pumps, one modified device, a syringe, and two new prototypes are evaluated and compared. We show that all of the devices are capable of generating suction pressure, but one pump stands out in terms of size, weight, and performance.     

Specific aspects of contemporary triathlon: implications for physiological analysis and performance

Triathlon competitions are performed over markedly different distances and under a variety of technical constraints. In 'standard-distance' triathlons involving 1.5km swim, 40km cycling and 10km running, a World Cup series as well as a World Championship race is available for 'elite' competitors. In contrast, 'age-group' triathletes may compete in 5-year age categories at a World Championship level, but not against the elite competitors. The difference between elite and age-group races is that during the cycle stage elite competitors may 'draft' or cycle in a sheltered position; age-group athletes complete the cycle stage as an individual time trial. Within triathlons there are a number of specific aspects that make the physiological demands different from the individual sports of swimming, cycling and running. The physiological demands of the cycle stage in elite races may also differ compared with the age-group format. This in turn may influence performance during the cycle leg and subsequent running stage. Wetsuit use and drafting during swimming (in both elite and age-group races) result in improved buoyancy and a reduction in frontal resistance, respectively. Both of these factors will result in improved performance and efficiency relative to normal pool-based swimming efforts. Overall cycling performance after swimming in a triathlon is not typically affected. However, it is possible that during the initial stages of the cycle leg the ability of an athlete to generate the high power outputs necessary for tactical position changes may be impeded. Drafting during cycling results in a reduction in frontal resistance and reduced energy cost at a given submaximal intensity. The reduced energy expenditure during the cycle stage results in an improvement in running, so an athlete may exercise at a higher percentage of maximal oxygen uptake. In elite triathlon races, the cycle courses offer specific physiological demands that may result in different fatigue responses when compared with standard time-trial courses. Furthermore, it is possible that different physical and physiological characteristics may make some athletes more suited to races where the cycle course is either flat or has undulating sections. An athlete's ability to perform running activity after cycling, during a triathlon, may be influenced by the pedalling frequency and also the physiological demands of the cycle stage. The technical features of elite and age-group triathlons together with the physiological demands of longer distance events should be considered in experimental design, training practice and also performance diagnosis of triathletes.     

Telephone triage in Western Australia

We describe the development and operations of the first large-scale Australian medical telephone triage centre. Studies have commenced to evaluate efficacy and safety of the service, as well as gauge the impact on demand for healthcare services.     

Progestin-induced apoptosis in the Macaque ovarian epithelium: differential regulation of transforming growth factor-beta.

BACKGROUND: Oral contraceptive (OC) use is associated with a reduced risk of ovarian cancer. An OC component, progestin, induces apoptosis in the primate ovarian epithelium. One regulator of apoptosis is transforming growth factor-beta (TGF-beta). We determined the effect of progestin on TGF-beta expression in the primate ovarian epithelium and examined the relationship between TGF-beta expression and apoptosis. METHODS: Female cynomolgus macaques were randomly assigned to receive a diet for 35 months containing no hormones (n = 20); the OC Triphasil (n = 17); or each of its constituents, ethinyl estradiol (estrogen, n = 20) or levonorgestrel (progestin, n = 18 ), alone. Ovarian sections were immunostained with monoclonal antibodies against TGF-beta1 or TGF-beta2 plus TGF-beta3 (TGF-beta2/3) isoforms. The expression of TGF-beta isoforms in four ovarian compartments (epithelium, oocytes, granulosa cells, and hilar vascular endothelium) was compared among treatment groups. The association between TGF-beta expression and apoptosis, as determined by morphology and histochemistry, was examined in ovarian epithelium. All statistical tests were two-sided. RESULTS: Compared with ovaries from the control and estrogen-only-treated monkeys, the ovaries of progestin-treated monkeys showed 1) a marked decrease in the expression of TGF-beta1 and a concomitant increase in the expression of the TGF-beta2/3 isoforms in the ovarian epithelium (P<.001), 2) an increase in the expression of TGF-beta2/3 in the hilar vascular endothelium (P<.001), and 3) a marked decrease in TGF-beta2/3 expression in granulosa cells (P<.001). The apoptotic index of the ovarian epithelium was highly associated with the change in expression from TGF-beta1 (P<.001) to TGF-beta2/3 (P相似文献   

Photoperiodic regulation of the reproductive axis in male zebra finches, Taeniopygia guttata

In arid central Australia, breeding of zebra finches (Taeniopygia guttata) tends to take place immediately after the aperiodic rainfall-this being irrespective of the time of year. As a result, zebra finches have traditionally been considered nonphotoperiodic. Despite this, there are some published reports of photoperiodic effects on behavior in zebra finches. Therefore, we transferred singly housed male zebra finches from a photoperiod of 14 h light and 10 h dark per day (14L:10D) to either 20L:4D or 8L:16D. Control birds remained exposed to 14L:10D. Plasma LH, testicular volume, and body mass were assessed at the start of the experiment and at intervals for a period of 56 days. Testicular mass was measured at the end of the 56-day period. Plasma LH increased significantly in the 20L:4D group after 14 days, but decreased again by 56 days, presumably an effect of increased gonadal steroid negative feedback. Plasma LH did not change significantly in the other two groups. Testicular volume increased steadily in the 20L:4D group during the treatment period and it was significantly higher than that of the 8L:16D group at the end of the experiment. After 56 days of treatment, combined testicular mass in the 20L:4D group was much greater than that of the 8L:16D group, but not quite statistically different from the 14L:10D group. There was no statistical difference in testicular mass between the 14L and 8L groups. Body mass did not differ between any of the groups at any time in the experiment. Our results are consistent with zebra finches being photoperiodic to some degree, despite their opportunistic breeding strategy. When considered in conjunction with recent reports of photoperiodic responses in tropical avian species, these data suggest that the ability to respond to changing photoperiod is more common among avian species than previously hypothesized.     

Influence of cyclodextrin complexation on the in vitro permeation and skin metabolism of dexamethasone

The influence of complexation of a model drug, dexamethasone acetate (DMA), with beta-cyclodextrin (beta-CyD) and hydroxypropyl-beta-cyclodextrin (HP-beta-CyD) on the in vitro permeation through hairless mouse skin and on skin metabolism have been investigated. Complexation with CyDs increased the amount of DMA permeated in the order of 2.0 and 3.0 times for beta-CyD and HP-beta-CyD, respectively. The partition coefficient, between stratum corneum and buffer (K(SC/buffer)), for DMA decreased when the drug was an inclusion complex, being greatest for DMA/HP-beta-CyD complex. Complexation protected the drug against skin metabolism. The increase of skin permeation and stability of the model drug in the skin suggest that the complexation with beta-CyD and HP-beta-CyD is a rational way to improve the physical-chemical properties of drugs for use in transdermal delivery systems.     

The apoptotic pathway: a target for therapy in chronic lymphocytic leukemia

Cell division and apoptosis (programmed cell death) are the two major physiological processes which control the size of cell populations. Chronic lymphocytic leukaemia arises as a result of the clonal expansion of, usually B-, lymphocytes in which a dysregulation of apoptosis leads to prolonged cell survival. The same process becomes exaggerated with increasing drug resistance, the usual cause of treatment failure in this condition. The identification of points in the apoptotic pathway at which dysregulation occurs is beginning to open up new therapeutic opportunities where the conventional cytotoxic chemotherapy approach is found to fail. Although these strategies are still in their infancy they may increase understanding of the pathogenesis of the disorder and overcome the problem of drug resistance.