The Mechanical Response and Tolerance of the Anteriorly-Tilted Human Pelvis Under Vertical Loading.

Military vehicle underbody blast (UBB) is the cause of many serious injuries in theatre today; however, the effects of these chaotic events on the human body are not well understood. The purpose of this research was to replicate UBB loading conditions on the human pelvis and investigate the resulting response in a controlled laboratory setting. In addition to better understanding the response of the human pelvis to high rate vertical loading, this test series also aimed to identify high rate injury thresholds. Twenty-seven post mortem human surrogate (PMHS) component pelvis tests were completed using the University of Virginia's (UVa) simulated blast rig under a range of loading conditions and postures. Of those tests, 17 were in the anteriorly-tilted posture and used to construct the human injury probability curve. Average seat pan (rigid) accelerations for this subset of tests ranged from 300 to 2400 g over 2 to 3 ms of positive phase duration. Post-test computed tomography (CT) scans and necropsies were performed to determine injuries and revealed a frequent occurrence of anterior and posterior injuries, resulting in unstable pelvis ring fractures. The resulting Human Injury Probability Curve (HIPC) yielded mean forces of 5529, 8516, and 12431 N as measured by mass compensated seat platen loadcells applied through the rigid seat to the bilateral ischium are associated with a 10, 25, and 50% risk for unstable pelvic ring sacrum fractures in an anteriorly-tilted pelvis (28° from vertical), respectively.

Effects of emissions from different type of residential heating upon cyclic guanosine monophosphate (cGMP) in blood platelets of residents.

We hypothesized that different types of residential heating would be associated with different levels of indoor carbon monoxide (CO) and further that this might result in a differential in the concentration of cyclic 3':5' guanosine monophosphate (cGMP) in blood platelets in exposed residents. Individuals, who were recruited from homes using different fuel for heating, donated a venous blood sample in the winter and in the summer. In the winter the median blood platelet cGMP value for the group using liquid propane gas (LPG) was 65% higher than for the group using piped natural gas for heating (p <0.001). Also in the group using LPG, the median concentration of cGMP in the winter was 39% higher than the summer median (p < 0.003). The mean indoor concentrations of CO were measured over a period of 1 week during the winter and were <1 ppm. We conclude that observed differences were associated with emissions from different types of heating but that CO exposure alone is too low to explain these.

Occupational exposure of midwives to nitrous oxide on delivery suites.

AIMS: To compare environmental and biological monitoring of midwives for nitrous oxide in a delivery suite environment. METHODS: Environmental samples were taken over a period of four hours using passive diffusion tubes. Urine measurements were taken at the start of the shift and after four hours. RESULTS: Environmental levels exceeded the legal occupational exposure standards for nitrous oxide (100 ppm over an 8 hour time weighted average) in 35 of 46 midwife shifts monitored. There was a high correlation between personal environmental concentrations and biological uptake of nitrous oxide for those midwives with no body burden of nitrous oxide at the start of a shift, but not for others. CONCLUSIONS: Greater engineering control measures are needed to reduce daily exposure to midwives to below the occupational exposure standard. Further investigation of the toxicokinetics of nitrous oxide is needed.

Evaluation of personal, environmental and biological exposure of paediatric anaesthetists to nitrous oxide and sevoflurane.

Paediatric anaesthetists are at higher risk of exposure to waste anaesthetic gases, which often exceed set safety limits. Recommended personal diffusive sampling techniques for monitoring exposure to waste anaesthetic gases may not give a true profile of exposure and hence biological sampling may also be necessary. We evaluated the exposure of paediatric anaesthetists to nitrous oxide and sevoflurane as assessed by personal environmental and biological samples. The influence of venue and technique, and the strength of the relationship among the various sampling techniques were analysed. The study found that exposure to nitrous oxide during paediatric anaesthetic inductions is still a major problem, although exposure to sevoflurane was usually within the accepted limits. The type of breathing system used and the presence of scavenging seem to influence this exposure, though surprisingly, the induction technique or the methods of airway control do not. No significant relationship was found between the various biological indicators measured.

The use of nitrous oxide in anaesthetic practice: a questionnaire survey.

Where practicable, exposure to a hazardous substance should be eliminated or adequately controlled. A postal questionnaire survey was sent to 10% of consultants from the Association of Anaesthetists of Great Britain and Ireland, to identify the level of use of nitrous oxide in current anaesthetic practice and identify any change of practice over the last 5 years. Details of anaesthetic practice were requested in three areas: nitrous oxide usage, availability of medical air on anaesthetic machines and the use of total intravenous anaesthesia. Replies were received from 320 consultants (75%). Of these, 49% felt that, over the last 5 years, their use of nitrous oxide had decreased. Twenty per cent of anaesthetists felt that there should be some restriction in availability of nitrous oxide. Where medical air was available, 32% felt that they would use it frequently. A total of 263 (83%) stated that they use total intravenous anaesthesia to some extent. The results showed that, although 49% of consultant anaesthetists had reduced their use of nitrous oxide, this was due to medical considerations rather than concerns over health and pollution issues arising from the use of nitrous oxide.

Biological monitoring of midwives' exposure to N(2)O using the Bio-VOC breath sampler.

The use of exhaled breath as a biological monitoring tool is still not widely used. Although there are now commercially available kits, there are limited data on biological guidance values for all but a few substances for breath monitoring. The study investigated the possibility of using an indirect breath sampler to measure the levels of nitrous oxide in the exhaled breath of midwives at a midpoint during their shift. Levels of nitrous oxide in the exhaled breath were measured at (0-727 ppm) with a mean level of 64 ppm. The correlation between the established personal environmental monitoring and exhaled breath monitoring was generally poor as was the correlation between duration of nitrous oxide exposure and levels in the exhaled breath. Clearly the use of exhaled breath as a tool for biological monitoring is more appropriate than other invasive procedures. The breath sampler used has been a readily acceptable tool for occupational hygiene monitoring in a busy hospital ward.

Enablers and constraints to walking for older African American and American Indian women: the Cultural Activity Participation Study.

Walking is a significant physical activity undertaken by a range of women from different ages, economic backgrounds, and family situations. The purpose of this analysis was to examine what conditions enabled walking to occur and what constraints prevented some older African American and American Indian women from walking as a physical activity. A descriptive analysis emerged related to three dimensions: the context of walking, how walking was enabled, and constraints to walking more or achieving greater satisfaction with walking as a physical activity. As more is known about how and why a behavior such as walking occurs, more can be done to raise the physical and mental quality of life for all people, regardless of race or gender.

Sociocultural perspectives on physical activity in the lives of older African American and American Indian women: a cross cultural activity participation study.

Illuminating the diversity and sociocultural specificity of women's experiences may be important if healthy lifestyles and quality of life are to be achieved. The incidence of cardiovascular disease linked to physical inactivity is high among African American and American Indian women. If more is understood about the experience of physical activity involvement, healthier living might be encouraged. Therefore, the purpose of this study was to explore the sociocultural meanings of physical activity for older (over the age of 40 years) African American and American Indian women who participated in the Cross Cultural Activity Participation Study (CAPS). Through qualitative in-depth interviews, we explored how sociocultural perspectives are related to perceptions about physical activity. Gender and other sociocultural factors influenced physical involvement on a continuum from negligible to significant. Both groups interviewed showed evidence that opportunities for physical activity in their free time did not always exist for them. For African American women, history and daily living issues were important factors limiting their involvement. Marginality limited American Indian women, but their cultural pride was often a source of physical activity. The juxtaposition of cultural and personal values emerged as a determinant of physical activity involvement among the women in this study. A further expansion of cultural and personal life situation perspectives is recommended to help understand the complex dimensions of physical activity as it relates to healthy living.

Environmental monitoring of nitrous oxide during dental anaesthesia.

AIM: The study was carried out to see if levels of nitrous oxide in dental theatres and community dental clinics were being controlled in accordance with the Control of Substances Hazardous to Health Regulations. SETTING: A multi-centre study looked at exposure levels in a dental teaching hospital and two community dental clinics in the South Wales area between 1997 and 1998. METHODS: A MIRAN infra-red spectrophotometer was used to measure static levels of nitrous oxide during general anaesthesia and conscious sedation. NIOSH method 6600 was used to collect personal samples of the individual administering the anaesthetic. RESULTS: The results showed compliance with the regulations when averaged out over an 8 hour time weighted average. However, over short periods of time peak concentrations of up to 1190 ppm were observed through static sampling, and up to 734 ppm through personal sampling. CONCLUSIONS: The results highlighted the need to provide adequate control measures such as anaesthetic gas scavenging, to reduce occupational exposure to dental staff in dental operating theatres and community dental clinics, therefore providing a safe working environment.

Staff exposure to anaesthetic gases in theatre and non theatre areas.

Environmental monitoring of anaesthetic gases was carried out in theatre areas in eight hospitals as well as in Delivery suites, radiology, radiotherapy and Dental suites. High staff exposures occurred in nontheatre areas although exposures in theatres were generally satisfactory. Environmental control measures are required where staff exposures exceed legal standards.

An environmental survey of compliance with Occupational Exposure Standards (OES) for anaesthetic gases.

Environmental monitoring of nitrous oxide and volatile agents was carried out between August 1996 and October 1997 within operating theatre areas in eight hospitals within the Bro Taf Health Authority. Static monitoring and personal sampling were undertaken to assess compliance with the Occupational Exposure Standards introduced in January 1996 by the Health and Safety Executive for anaesthetic agents. The monitoring concentrated on nitrous oxide with the results showing that compliance was being achieved. Limited monitoring was carried out of the volatile agents, which again were well below the Occupational Exposure Limits. Monitoring was also carried out in nontheatre areas in which anaesthetic agents were used. The results show that many of these locations, such as delivery suites and radiology units, have inadequate ventilation and no anaesthetic gas scavenging, both of which combined to produce levels that exceeded the standards.

Measuring physical activity in midlife, older, and minority women: issues from an expert panel.

This article summarizes the findings of an exploratory meeting of 53 experts brought together under the aegis of the Women's Health Initiative to identify important issues related to measuring physical activity in minority women, women in midlife (aged 40-75), and older women (aged > 75). The findings address five areas, three dealing with measurement and two concerning the design of surveys: (1) population characteristics to consider when measuring the physical activity of women and minority populations, (2) activity dimensions relevant to physical activity surveys, (3) measuring moderate and intermittent activities, (4) designing and administering physical activity surveys for older and minority women, and (5) establishing the reliability and validity of such physical activity surveys. Although the focus of the expert panel meeting was on identifying issues related to the measurement of physical activity in women, many issues summarized here can be generalized to children and men. The panel's findings concerning measuring physical activity are timely, as they directly bear on the challenges associated with the physical activity guidelines jointly issued by the Centers for Disease Control and Prevention and the American College of Sports Medicine and the recommendations made in the Surgeon General's 1996 report, Physical Activity and Health.

Environmental monitoring during gaseous induction with sevoflurane.

Recent research has shown that gaseous induction in adults with sevoflurane is an acceptable technique. This study was undertaken to assess if gaseous induction using sevoflurane carried in both oxygen alone, and in nitrous oxide and oxygen combined, would provide acceptable pollution levels. As an occupational exposure standard has not been set for sevoflurane, we used the target level of 20 ppm set by the manufacturer. Environmental monitoring was carried out in the anaesthetic room during eight lists where consecutive triple vital capacity sevoflurane inductions were performed. Time-weighted averages for both gases over the duration of the lists were well below the occupational exposure standards (mean 1.1 (range 0.6-1.7) for sevoflurane and 17.3 (12-23) for nitrous oxide). There were high peak concentrations during the induction process (8.3 (4.1-17) for sevoflurane and 172.4 (65-310) for nitrous oxide) although these decreased to low concentrations between anaesthetic inductions. Personal sampling was carried out from the anaesthetist's breathing zone and concentrations were also low (1.2 (0.8-2.1) for sevoflurane and 45.9 (10.1-261.6) for nitrous oxide.

Physical findings and symptoms of depot medroxyprogesterone acetate use in adolescent females.

STUDY OBJECTIVE: To document physical and symptomatic changes in adolescent females using depot medroxyprogesterone acetate (DMPA) for contraception. DESIGN: A 30-month prospective experimental study using a convenience sample of subjects. SETTING: A pediatric primary care clinic in Milwaukee, Wisconsin that serves an urban population of low socioeconomic status. PARTICIPANTS: A mostly African-American group of 53 patients (mean age 16.5 +/- 1.3 years). INTERVENTIONS: Subjects received 150 mg DMPA intramuscularly in either the deltoid or gluteus muscle. The first two DMPA injections were given 6-8 weeks apart in an effort to decrease menstrual irregularity. Subsequent injections were given every 3 months. A questionnaire was administered at each visit to document physical and symptomatic changes. MAIN OUTCOME MEASURES: Included weight change, frequency and amount of menstrual bleeding, and perceived side effects and satisfaction both documented with a 5-point Likert scale. RESULTS: At 5, 11, and 17 months of DMPA use, 75%, 40%, and 19% of subjects continued DMPA. The most commonly perceived side effects were weight gain (27%), headache (25%), irregular periods (24%), fatigue (23%), abdominal pain (18%), and decreased sexual desire (15%). Significant weight gain was noted with an average increase of 6.0 +/- 6.0 kg at 11 months of DMPA use and 9.0 +/- 5.4 kg at 17 months. No menstrual bleeding was experienced by 30%-40% of adolescents in any 3-month injection period, and those who bled averaged 8-13 days of bleeding between injections. No pregnancies occurred and 87% of patients were either satisfied or very satisfied with DMPA as a method of contraception. CONCLUSION: Despite the documented side effects, DMPA is an effective, acceptable contraceptive for some adolescent females who are at high risk for pregnancy.

Late glacial stage and holocene tropical ice core records from huascaran, peru.

Two ice cores from the col of Huascarán in the north-central Andes of Peru contain a paleoclimatic history extending well into the Wisconsinan (Würm) Glacial Stage and include evidence of the Younger Dryas cool phase. Glacial stage conditions at high elevations in the tropics appear to have been as much as 8 degrees to 12 degrees C cooler than today, the atmosphere contained about 200 times as much dust, and the Amazon Basin forest cover may have been much less extensive. Differences in both the oxygen isotope ratio zeta(18)O (8 per mil) and the deuterium excess (4.5 per mil) from the Late Glacial Stage to the Holocene are comparable with polar ice core records. These data imply that the tropical Atlantic was possibly 5 degrees to 6 degrees C cooler during the Late Glacial Stage, that the climate was warmest from 8400 to 5200 years before present, and that it cooled gradually, culminating with the Little Ice Age (200 to 500 years before present). A strong warming has dominated the last two centuries.

"I have a soul that dances like Tina Turner, but my body can't": physical activity and women with mobility impairments.

The purpose of this study was to explore the experiences and meanings of physical activity for women with disabilities and to interpret the implications of physical activities specifically for women with mobility impairments. In-depth qualitative interviews were used to uncover data about how women with mobility impairments experienced physical activity and leisure. Emerging themes addressed the value of physical activity, attitudes toward one's disability and participation in physical activity, and conditions necessary for involvement in physical activity. Four values were associated with physical activities: leisure, therapy, maintenance, or perceived little value. Attitudes toward one's disability and physical activity resulted in conforming, resisting, or adjusting behavior. Energy/stamina/low pain level, transportation, removal of social fears, accessibility, and social support were the individual or combined conditions that influenced values and attitudes regarding physical activities. The results of this study highlighted the need to consider and improve opportunities for physical activity for women with mobility impairments.

In vitro steroidogenesis by granulosa cells from equine pre-ovulatory follicles.

Twenty-three follicles were collected from 14 mares on specific days and grouped to represent follicles from early (Group 1; n = 6), mid (Group 2; n = 11) and late (Group 3; n = 6) oestrus, as described previously (Tucker et al., 1988). Isolated granulosa cells (GC) from each follicle were cultured in multiwell plates containing either Eagle's Minimum Essential Medium (MEM) alone, eLH (300 ng/ml), eFSH (300 ng/ml) or eLH + eFSH (300 ng/ml each), in the presence or absence of 0.5 microM testosterone. Media were collected and replaced at 24 h of culture, and 24 h later, media were again collected and cultures terminated. Media were assayed for oestradiol-17 beta (E2), progesterone (P4), androstenedione (A) and testosterone (T) by radioimmunoassay (RIA). Media containing exogenous T were assayed for E2 and P4. There was no effect of exogenous gonadotrophins on steroid secretion by GC from any group, so these values were pooled and averaged. Steroid concentrations were expressed as ng/ml/1000 live cells seeded (mean +/- s.e.m.). Progesterone was the predominant steroid secreted by GC from all groups without added T after 24 h of culture, and was highest in media from Group 3 (7.86 +/- 1.19 ng/ml) 1000 cells; vs Group 1 (0.02 +/- 0.004 ng/ml/1000 cells) and Group 2 (0.15 +/- 0.03 ng/ml/1000 cells; P less than 0.001). Androstenedione was the predominant androgen secreted, but its levels did not change from group to group. Oestradiol and T levels were comparable in media from Group 1 cultures (E2: 0.003 +/- 0.0004 ng/ml/1000 cells; T: 0.003 +/- 0.0009 ng/ml/1000 cells), but E2 was highest in Group 2 media (0.17 +/- 0.11 ng/ml/1000 cells; P less than 0.001) and T levels were greatest in Group 3 (0.02 +/- 0.003 ng/ml/1000 cells; P less than 0.005). In the presence of exogenous T, E2 increased in media from all groups (P less than 0.0001). Oestradiol levels from Group 1 (0.52 +/- 0.12 ng/ml/1000 cells) and Group 3 (0.57 +/- 0.09 ng/ml/1000 cells) cultures were not different, but were highest in media from Group 2 (2.15 +/- 0.29 ng/ml/1000 cells; P less than 0.01). By 48 h, P4 secretion was higher in all groups (P less than 0.0001) and was the predominant steroid secreted by Group 3 GC. Progesterone levels were not affected by the addition of T. Androstenedione increased in Group 3 media (P less than 0.001), whereas E2 and T remained unchanged. These results suggest that the pattern of equine GC steroid secretion changes as follicular maturation proceeds.(ABSTRACT TRUNCATED AT 400 WORDS)

Acid and alkaline phosphatase in bovine antral follicles.

Acid and alkaline phosphatases were measured in the follicular fluid of 766 individual follicles from 96 cows. Follicles were obtained by bilateral ovariectomy or at slaughter from animals at various stages of the estrous cycle and pregnancy. Mean follicle size varied with the physiological state of the cow (P less than .0001). Acid phosphatase activity (U/microliters) varied inversely with follicle size (P less than .001) but not with stage of the estrous cycle or gestation. Total acid phosphatase activity per follicle increased with follicle size (P less than .05). Neither acid phosphatase nor alkaline phosphatase concentration was associated with atresia. Alkaline phosphatase activity (U/microliters) was greater in the smallest follicles (less than 50 microliters) than in other size groups (P less than .0001). Alkaline phosphatase activity (U/microliters) was greater (P less than .05) during the preovulatory phase of the estrous cycle than during other phases. A high concentration of follicular fluid phosphatases cannot be used as a marker for atresia but is characteristic of healthy small antral follicles.