Physical and psychological stressors linked with stress fractures in recruit training.

This study aimed to measure ambulation in infantry army basic training, and to evaluate if covering more distance can explain stress fractures in a stressor-stress model. Forty-four male combat recruits (18.7 ± 0.7 years) participated in a 6-month rigorous high intensity combat training program. Baseline data included anthropometric measurements, VO(2)max, and psychological questionnaires. Actual distance covered was measured using a pedometer over an 11-week training period. Psychological questionnaires were repeated after 2 months. Sixteen recruits were diagnosed with stress fractures by imaging (SFi = 36.4%). Statistical analysis included comparing measured variables between SFi and those without stress fractures (NSF). The recruits covered 796 ± 157 km, twofold the distance planned of 378 km (P < 0.001). The SFi group covered a distance 16.4% greater than that of the NSF group (866 ± 136 and 744 ± 161 km, respectively, P < 0.01), and also demonstrated greater psychological stress. These data reveal the importance of adherence to or enforcement of military training programs. In the light of these data, the Israeli Defense Forces program needs reappraisal. A stressor-stress response might explain the susceptibility of certain recruits for injury. Using advanced technology, monitoring ambulation may prevent stress fracture development by limiting subjects exceeding a certain level. Psychological profile may also play a role in predicting stress fracture development.

Effect of vaginal progesterone, administered to prevent preterm birth, on impedance to blood flow in fetal and uterine circulation.

OBJECTIVE: To evaluate the effect on the maternal and fetal circulation of progesterone administered to prevent preterm birth. METHODS: We used an observational cohort study design. The study group included 44 women at 18-32 weeks' gestation who presented with an episode of preterm labor, with or without history of delivery before 34 weeks' gestation, or an incidental finding of short cervix (≤ 25 mm). Doppler flow assessment of the umbilical artery, fetal middle cerebral artery and uterine arteries was performed before and 24 h after vaginal administration of progesterone. RESULTS: Seventeen (38.6%) women gave birth before term, but only nine (20.4%) did so before 34 weeks' gestation. Following progesterone treatment, there was a statistically significant decrease in the pulsatility index of the fetal middle cerebral artery (mean reduction, 18.2%; mean change in pulsatility index, 0.44 (95% CI, 0.25-0.63), P < 0.001), with no changes in the other vessels. Comparison of the women who gave birth before with those who delivered at term yielded no significant differences in Doppler flow parameters in any vessel examined, either before or after progesterone treatment. CONCLUSION: Treatment with vaginal progesterone is associated with a lower pulsatility index in the fetal middle cerebral artery, suggesting a vasodilatory effect on the fetal circulation.

Detection of growth-restricted fetuses using a patient-specific model.

Fetal growth restriction (FGR) is one of the major contributors to adverse perinatal outcome. The purpose of this work was to extend the use of Ultrasound Doppler measurements and allow early and accurate detection of FGR. To this end, a mathematical model was developed to represent the major fetal hemodynamic mechanisms involved. Based on model parameters' values, the forward model predicted flow waveforms at the locations where Doppler measurements are routinely performed. Blood velocity waveforms measured in 20 FGR and 20 normal fetuses were used as inputs to an inverse model solution to obtain the parameters' values of the specific fetus. Model predictions indicated significant changes in the circulation of FGR fetuses compared to normal fetuses. Estimated cardiac output was significantly lower in the FGR group compared to the control group (330 ± 52 ml min(-1) Kg(-1) compared to 396 ± 52 ml min(-1) Kg(-1), P<0.001). Also, estimated cardiac output distribution towards the placenta was lower for the FGR group (145 ± 49 ml min(-1) Kg(-1) compared to 181 ± 31 ml min(-1) Kg(-1), P<0.01). In the FGR group the model indicated also significant increase in estimated cardiac output distribution towards the brain (9.6 ± 0.7%, compared to 8.0 ± 1.6 %, P<0.01) and in the degree of blood shunted by the ductus venosus (60.6 ± 17.7 %, compared to 39.7 ± 14.8 %, P<0.01), indicating severe brain-sparing state in these fetuses. We conclude that patient-specific mathematical modeling is a promising direction for personalizing and optimizing the treatment options in pregnancies complicated by fetal growth-restriction.

Factors associated with self-evaluated severity of illness and quality of life in male Israeli asthmatic soldiers.

OBJECTIVE: To evaluate whether the asthmatic condition and quality of life of male asthmatic Israeli soldiers deteriorate during army service. METHOD: We retrospectively assessed 178 asthmatic soldiers during service using an adapted version of the Mini Asthma Quality of Life Questionnaire, and compared it to their condition before service. The participants responded additionally to questionnaires assessing psychosocial resources and adjustment to illness. RESULTS: The self-evaluated degree of asthma disease severity (SEDOAD) of the participants deteriorated in the army compared to before service. Soldiers with mild SEDOAD during service, compared to soldiers with severe (and in most cases also moderate) SEDOAD, had less severe medically evaluated and self-evaluated asthma before service. Mild SEDOAD participants showed, additionally, lower inclination towards active seeking of asthma-related information, more favorable health care-related attitudes, less unfavorable effects of their illness on military and extra-military functioning, greater reported pre-enlistment optimism, and a greater belief in their ability to cope successfully with their asthma during service. CONCLUSION: SEDOAD and the quality of life during service are associated not only with pre-enlistment asthma severity, but also with the manner in which the soldier perceives the influence of the illness on his health condition, and the manner in which he copes with this influence.