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Objective: To evaluate whether an intensive, medically supervised exercise intervention improved maternal glycemia and gestational weight gain in obese pregnant women when compared with routine prenatal care., Methods: This randomized controlled trial compared a medically supervised exercise intervention with routine prenatal care. The primary outcome was a reduction in mean maternal fasting plasma glucose in the intervention group by 6.9 mg/dL at the time of a 75-g oral glucose tolerance test at 24-28 weeks of gestation. Secondary outcomes included excessive gestational weight gain. The intervention consisted of 50-60 minutes of exercise: warm-up, resistance or weights, aerobic exercises, and cool-down. All women received routine prenatal care. Power calculation determined that 24 women were required per group to detect a difference of 6.9 mg/dL in fasting plasma glucose between groups based on an independent-sample t test for statistical power of 80% at a type I error rate of 0.05. A sample size of 44 per group was planned to allow a dropout rate of 33%., Results: From November 2013 through August 2015, 88 women were randomized: 44 each to the exercise and control groups. Eight women in the control group and 11 in the intervention group did not complete the trial at 6 weeks postpartum (P=.61), but 43 in each group attended the 24- to 28-week glucose screen. There were no baseline maternal differences between groups. Classes commenced at a mean of 13 4/7±1 2/7 weeks of gestation. In early pregnancy, 51.1% (n=45/88) had an elevated fasting plasma glucose (92-125 mg/dL). There was no difference in the mean fasting plasma glucose at 24-28 weeks of gestation: 90.0±9.0 mg/dL (n=43) compared with 93.6±7.2 mg/dL (n=43) (P=.13) or in the incidence of gestational diabetes mellitus at 24-28 weeks of gestation: 48.8% (n=21/43) compared with 58.1% (n=25/43) (P=.51) in the control and exercise groups, respectively. At 36 weeks of gestation, excessive gestational weight gain greater than 9.1 kg was lower in the exercise group, 23.5% compared with 45.2% in the control group (P<.05)., Conclusion: An intensive, medically supervised exercise intervention for obese women from early pregnancy did not improve maternal glycemia. Pregnant women who are obese, however, should be advised to exercise because it attenuates excessive gestational weight gain., Clinical Trial Registration: International Standard Randomised Controlled Trials (ISRCTN) registry, ISRCTN 31045925.

Introduction: Ankle sprains are the most common orthopedic pathology experienced during sport and physical activity and often result in chronic ankle instability (CAI). Understanding how to prevent CAI is difficult because of the costs and logistics associated with clinical trials aimed at preventing the heterogeneous symptoms associated with CAI. Thus, a need exists to develop an animal model that presents similar long-term consequences as CAI to assess preclinical data. Thus, the purpose was to determine whether surgically transecting the lateral ligaments of a mouse hind limb results in the development of CAI-like symptoms 12 months after injury., Methods: Thirty male mice (CBA/J) were randomly placed into a SHAM (control), CFL (calcaneofibular ligament; mild ankle sprain), or ATFL/CFL (anterior talofibular ligament/CFL; severe) ankle sprain group and housed individually. Three days after surgically transecting the respective lateral ligaments, mice were given a solid surface running wheel and daily running wheel measurements were recorded. Outcome measures of balance and gait were obtained before and at 4, 48, 54, and 60 wk after injury., Results: The ATFL/CFL group had significantly more hind foot slips than the CFL and SHAM groups (P < 0.05). The CFL also had more hind foot slips relative to the SHAM group (P < 0.05). The ATFL/CFL group was significantly less physically active relative to the SHAM and CFL groups (P < 0.05). A cut score of 4.75 foot slips had a sensitivity of 0.68 and specificity of 1.00 and indicates that 70% (14/20) of mice with an ankle sprain had developed CAI., Conclusions: The results of this study indicate that an acute ankle sprain in mice can result in the development of CAI-like symptoms 12 months after injury.

Purpose: The purpose of this study was to investigate the age-related changes in diastolic filling parameters in the aging hearts of active C57Bl/6J mice throughout the life span to indicate optimal age periods for improvements in resting diastolic parameters., Methods: Fourteen C57Bl/6J mice (seven males and seven females) were individually housed at 8 wk of age in cages with a running wheel, magnetic sensor, and digital odometer. Duration, distance, and running velocity were recorded daily. Fourteen additional mice C57Bl/6J mice (seven males and seven females) were placed in individual cages without running wheels at 8 wk of age. Pulsed-wave Doppler transmitral inflow recordings with a SONOS 5500 ultrasound and 15-6L ultrasound probe were used to image the left ventricle every 4 wk throughout the life span., Results: Peak E wave filling velocities were significantly greater by the start of the second quarter of the life span in the mice with access to running wheels (P < 0.0001). Peak E wave velocities improved in both groups during the first half of the life span (P < 0.0001) and declined throughout the second half of the life span (P < 0.0001). Early-to-late (E:A) filling ratio was significantly greater for the physically active mice by the start of the second quarter of the life span (P < 0.0001) and continued throughout most of the remainder of the life span (P < 0.0001). No differences were observed between the two groups of mice with peak A wave filling velocities (P > 0.05). Similar findings were observed when corrected for resting heart rate., Conclusions: Lifelong physical activity resulted in greater diastolic filling parameters by the second quarter of the life span, highlighting the clinical importance of regular aerobic activity in young adulthood as a mechanism for improved left ventricular performance with aging.

Introduction: Ankle sprains remain the most common orthopedic pathology. Conducting long-term studies in humans is difficult and costly, so the long-term consequences of an ankle sprain are not entirely known., Purpose: The objective of this study is to develop and test a mechanical ankle instability model in mice., Methods: Thirty male mice (CBA/2J) were randomly placed into one of three groups: the transected calcaneal fibular ligament (CFL) group, the transected anterior talofibular ligament (ATFL)/CFL group, and a SHAM group. Three days after surgery, all of the mice were individually housed in a cage containing a solid surface running wheel, and daily running wheel measurements were recorded. Before and after surgery, measures of balance and gait were measured on all mice for 4 wk., Results: The mice in the ATFL/CFL group had significantly decreased duration (P = 0.0239), distance (P = 0.013), and speed (P = 0.003) compared with the SHAM group during week 1. During weeks 2 and 3, the ATFL/CFL group had significantly less distance (P = 0.0001) and duration (P = 0.002) compared with the SHAM and CFL-only group. The transection of the lateral ankle ligaments did affect the number of slips experienced during the balance test. The ATFL/CFL group had greater slips at 1 and 4 wk postsurgery (P = 0.05), whereas the CFL-only group had greater slips at 3 d and 1 wk postsurgery (P = 0.05). Relative to the SHAM group, the ATFL/CFL group and CFL-only group had smaller right-stride lengths (involved limb) at 3 d postsurgery (P = 0.05). The ATFL/CFL group also had smaller right-side stride lengths at 1 and 4 wk postsurgery (P = 0.05)., Conclusions: The results of this study indicate that a mouse model can be used to induce mechanical instability in the ankle.

Background: Simultaneous recordings of arterial blood pressure (ABP) and middle cerebral artery blood velocity can be used to calculate the apparent zero flow pressure (aZFP). The inverse of the slope of the pressure-velocity relationship is known as resistance area product (RAP) and is an index of cerebrovascular resistance. There is little information available regarding the effects of vasoactive drugs, arterial carbon dioxide (Paco(2)), and impaired cerebral autoregulation on aZFP and RAP during general anesthesia. During isoflurane anesthesia, we investigated the effects of hypocapnia and the effects of a phenylephrine infusion, on aZFP and RAP., Methods: Radial ABP and transcranial Doppler middle cerebral artery blood velocity signals were recorded in 11 adults undergoing isoflurane anesthesia. A phenylephrine infusion was used to increase ABP and ventilation was adjusted to control Paco(2). Cerebral hemodynamic variables were compared at two levels of mean ABP (approximately 80 and 100 mm Hg) and at two levels of Paco(2): normocapnia (Paco(2) 38-43 mm Hg) and hypocapnia (Paco(2) 27-34 mm Hg). Two aZFP analysis methods were compared: one based on linear regression and one based on Fourier analysis of the waveforms., Results: At the lower ABP, aZFP was 23 +/- 11 mm Hg and 30 +/- 13 mm Hg (mean +/- sd) with normocapnia and hypocapnia, respectively (P < 0.001) and RAP was 0.76 +/- 0.97 mm Hg x s x cm(-1) and 1.16 +/- 0.16 mm Hg x s x cm(-1) with normocapnia and hypocapnia, respectively (P < 0.001). Similar effects of hypocapnia were seen at the higher ABP. With normocapnia, isoflurane impaired cerebral autoregulation and aZFP did not change with the increase in ABP. With hypocapnia, cerebral autoregulation was not significantly impaired and increasing ABP was associated with increased aZFP (from 30 +/- 13 to 35 +/- 13 mm Hg, P < 0.01) and increased RAP (from 1.16 +/- 0.16 to 1.52 +/- 0.20 mm Hg x s x cm(-1), P < 0.001). Calculation of the relative contributions of aZFP and RAP to the cerebral hemodynamic responses indicated that changes in RAP appeared to have a greater influence than changes in aZFP. The mean difference between the two methods of determining aZFP (Fourier-regression) was 0.5 +/- 3.6 mm Hg (mean +/- 2sd)., Conclusions: During isoflurane anesthesia, two interventions that increase cerebral arteriolar tone, hypocapnia and the autoregulatory response to increasing ABP, were associated with increased RAP and increased aZFP. The effect of changes in RAP appeared to be quantitatively greater than the effects of changes in aZFP. These results imply that arteriolar tone influences cerebral blood flow by controlling both resistance and effective downstream pressure.

Objective: To quantify overdetection and underdetection of hypertension caused by systematic sphygmomanometer errors permitted by the current European standard (EN 1060 'noninvasive sphygmomanometers')., Methods: We carried out Monte Carlo simulation of measurement of blood pressure (BP) of the adult Australian population using sphygmomanometers showing systematic errors compliant with the EN 1060 standard. We repeated the simulations limiting systematic sphygmomanometer errors to +/-1 mmHg. Simulated BP measurements included systematic sphygmomanometer error, random intraindividual BP variability and random measurement error., Results: After three visits, underdetection of hypertension is common owing to variability of BP measurements and systematic errors of sphygmomanometers. After three visits, the wide tolerances of EN 1060 are responsible for approximately 4.9 and 11% of underdetection of systolic and diastolic hypertension, respectively. Underdetection is worse in some groups, for example, permitted sphygmomanometer error causes 20% of all undetected systolic hypertension in 18-24 year-old women. The current standard also results in overdetection of hypertension. Permitted sphygmomanometer error causes 5.8 and 14% of the overdetection of systolic and diastolic hypertension, respectively, after three visits. Overdetection is worse in some groups, for example, after three visits, permitted sphygmomanometer error causes 19% of falsely detected diastolic hypertension in 18-24 year-old men. For all adults, reduction of permitted sphygmomanometer error to +/-1 mmHg achieves approximately the same improvement in hypertension detection as at least one additional visit to the clinician., Conclusion: Systematic sphygmomanometer errors permitted by the current standard are a preventable cause of clinically significant overdetection and underdetection of hypertension. The standard should be revised to make the effects of equipment related systematic errors negligible compared with the effects of physiological variability.

Background: Intravenous and inhalational anesthetic agents have differing effects on cerebral hemodynamics: Sevoflurane causes some vasodilation, whereas propofol does not. The authors hypothesized that these differences affect internal carotid artery pressure (ICAP) and the apparent zero flow pressure (critical closing pressure) during carotid endarterectomy. Vasodilation is expected to increase blood flow, reduce ICAP, and reduce apparent zero flow pressure., Methods: In a randomized crossover study, the gradient between systemic arterial pressure and ICAP during carotid clamping was measured while changing between sevoflurane and propofol in 32 patients. Middle cerebral artery blood velocity, recorded by transcranial Doppler, and ICAP waveforms were analyzed to determine the apparent zero flow pressure., Results: ICAP increased when changing from sevoflurane to propofol, causing the mean gradient between arterial pressure and ICAP to decrease by 10 mmHg (95% confidence interval, 6-14 mmHg; P<0.0001). Changing from propofol to sevoflurane had the opposite effect: The pressure gradient increased by 5 mmHg (95% confidence interval, 2-7 mmHg; P=0.002). Ipsilateral middle cerebral artery blood velocity decreased when changing from sevoflurane to propofol. Cerebral steal was detected in one patient after changing from propofol to sevoflurane. The apparent zero flow pressure (mean+/-SD) was 22+/-10 mmHg with sevoflurane and 30+/-14 mmHg with propofol (P<0.01). There was incomplete drug crossover due to the limited duration of carotid clamping., Conclusions: Compared with sevoflurane, ipsilateral ICAP and apparent zero flow pressure are both higher with propofol. Vasodilatation associated with sevoflurane can cause cerebral steal.

Purpose: It is currently unknown whether the age of wheel exposure influences running wheel activity in mice. The purpose of this study was to determine whether the age at which a running wheel was introduced affected running wheel activity for a subsequent 15-wk period., Methods: Twenty female C57Bl/6J mice (age 7 wk) were assigned to one of four experimental groups. Group 1 received a running wheel at 7 wk of age. Thereafter, groups 2, 3, and 4 received running wheels at 10, 13, and 16 wk of age, respectively. Daily running wheel activity (duration, distance, and velocity) was recorded from the time of running wheel exposure until 30 wk of age., Results: A repeated-measures MANOVA found significant differences between groups for distance (P = 0.02), duration (P = 0.04), and velocity (P = 0.001) during the 15-wk concurrent running period (age 16-30 wk). Post hoc tests revealed significantly greater distance and duration in group 4 compared with group 2 and significantly greater velocity in group 4 compared with each of the other groups. Significant interactions were found between groups over time for distance (P = 0.01) and duration (P = 0.05). No significant difference between groups was observed for body weight over the 24-wk period (P > 0.05)., Conclusion: Although differences were found between groups 2 and 4, these data suggest that the age at which physical activity is introduced has little influence on the subsequent level of physical activity in C57Bl/6J mice. However, it appears that introduction of the running wheel at 16 wk of age results in greater within group variance, suggestive of a greater environmental influence on daily running wheel activity.

Objective: To estimate the effects of systematic errors in measurements of blood pressure on the diagnosis of hypertension., Methods: We fitted regression curves to distributions of diastolic and systolic BP from recent Canadian and UK surveys and calculated the effect of systematic measurement errors on changes in the numbers of patients who would be classified hypertensive at thresholds of 85, 90 and 95 mmHg diastolic and 140 and 160 mmHg systolic pressure respectively., Results: Overestimation of diastolic BP by 5 mmHg increases the number of patients whose diastolic BP exceeds 85, 90 and 95 mmHg by 102, 132 and 166% respectively. Equivalent underestimation causes 57, 62 and 67% respectively of hypertensive patients to be missed. If systematic error in diastolic pressure is limited to +/-1 mmHg the diagnosis errors are between -15 and +23%. Overestimation of systolic BP by 3 and 5 mmHg increases the number classified as hypertensive by 24 and 43% respectively. Equivalent underestimation causes 19 and 30% of patients with systolic hypertension to be missed., Conclusions: Small systematic errors in BP measurements may cause large variations in the proportion of patients diagnosed as hypertensive. To limit over- or under-diagnosis of diastolic hypertension to approximately 20%, systematic errors in diastolic BP measurements should be limited to 1 mmHg. An uncertainty of 3 mmHg may be adequate for detecting systolic hypertension.

We have investigated the influence of hypoxia on the radiosensitivity of 4 early-passage tumor cell lines that were established from malignant glioma patients at our Institute. These cell lines were M006, M059J (a highly radiosensitive line), M059K (a radioresistant line derived from the same biopsy as M059J), and M010b. The GM637 human fibroblast cell line was used as a normal control. The oxygen enhancement ratios (OERs) for these cell lines, determined using a clonogenic survival assay, were approximately 3.6 (GM637), approximately 3.7 (M006), approximately 2.5 (M010b), approximately 2.1 (M059K), and approximately 3.5 (M059J). The broad range of OERs for these glioma lines was not related to cellular glutathione levels or to differences in intrinsic cellular radiosensitivity. Because studies with rodent cell lines indicate that defects in certain DNA repair genes, including ERCC1, can greatly influence cellular OERs, and because several such repair genes, including ERCC1, localize to a region of chromosome 19q that is close to a common deletion in human glioma, we reasoned that such deletions might contribute to the diverse OERs of these tumor cell lines. However, measurements of ERCC1 protein levels using immunofluorescence staining or Western blotting, of ERCC1 mRNA levels using Northern blotting, and of functional nucleotide excision repair capability using the UV/adenovirus reactivation assay, failed to indicate any deficit in these activities. Thus, although the effect of hypoxia on the radiosensitivity of different human glioma cell lines can vary widely, the mechanism of this effect remains unknown. The potential implications of this finding for radiation therapy, and especially for hypoxia imaging-guided intensity-modulated radiation therapy (IMRT) treatment planning, are discussed.

Background: Partial rebreathing is a noninvasive method for measuring pulmonary blood flow (PBF). This study examines the systematic errors produced by the partial rebreathing technique utilizing a comprehensive mathematical model of the cardiorespiratory system of a healthy, 70-kg adult male., Methods: The model simulates tidal breathing through a branched respiratory tree and incorporates the effects on carbon dioxide dynamics of lung tissue mass, vascular transport delays, multiple body compartments, and realistic blood-gas dissociation curves. Four studies were performed: (1) errors produced under standard conditions, (2) effects of recirculation, (3) effects of alveolar-proximal airway partial pressure of carbon dioxide (Pco(2)) differences, and (4) effects of rebreathing time., Results: Systematic errors are less than 10% when the simulated PBF is between 3 and 6 l/min. At 2 l/min, PBF is overestimated by approximately 35%. At 14 l/min, PBF is underestimated by approximately 40%. At PBF of greater than 6 l/min, recirculation causes approximately 60% of the systematic error, alveolar-proximal airway differences cause approximately 20%, and alveolar-arterial differences cause approximately 20%. The standard rebreathing time of 50 s is shown to be excessive for PBF of greater than 6 l/min. At PBF of less than 3 l/min, errors are caused by inadequate rebreathing time and alveolar-arterial gradients., Conclusions: Systematic errors in partial rebreathing cardiac output measurements have multiple causes. Our simulations suggest that errors can be reduced by using a variable rebreathing time, which should be increased at low PBF so that quasi-equilibrium in the alveoli can be achieved and decreased at high PBF to reduce the effects of recirculation.

Purpose: The contribution of genetic factors to aerobic capacity is unknown. The purpose of this study was to measure maximal aerobic performance among inbred strains of mice to provide basic heritability estimates., Methods: Eight female mice, 8 to 10 wk old, in 10 inbred strains (A/J, AKR/J, Balb/cJ, C(3)H/HeJ, C57Bl/6J, C57L/J, C(3)Heb/FeJ, CBA/J, DBA/2J, and SWR/J) were run on a treadmill until exhaustion. The protocol started at 22 m.min(-1) and increased in speed approximately 6 m.min(-1) every 4 min. After 4 min at 42.4 m.min(-1), the grade was increased 2% every 4 min thereafter until the mouse could not run off of the shock grid (150 V; 1.5 mA)., Results: There were significant differences between inbred strains in maximal duration of exercise accomplished (P < 0.0001). The order of strain-specific exercise duration was Balb/cJ > SWR/J > CBA/J > C57L/J > C3H/HeJ > C3Heb/FeJ > C57Bl/6J > AKR/J > DBA/2J > A/J. Two measures of heritability in the broad sense, intraclass correlation (0.73), and the coefficient of genetic determination (0.58) were both significant., Conclusion: These data indicate that there is a strong genetic contribution to aerobic capacity in mice.

Objective: To establish whether fetal DNA can be identified in the maternal circulation in first-trimester spontaneous abortions., Methods: Women with confirmed spontaneous abortions and no histories of previous pregnancy were recruited. Peripheral venous blood samples were obtained and DNA extracted. Real-time quantitative polymerase chain reaction was done using SRY and beta-actin systems for calculating fetal and total DNA, respectively., Results: Of 25 women, SRY-specific signals were detected in 11 indicating that the abortions were male. The remaining 14 were negative for the SRY gene. Women with positive results were of similar gestational age to those who were negative (mean 68.4 and 69.0 days). Fetal:total DNA ratio was calculated for positive samples and ranged from 15.8 to 360.1 x 10(+3). Mean ratio was 99.4 x 10(+3) and median was 67.5 x 10(+3)., Conclusion: Fetal DNA is present in the maternal circulation of first-trimester spontaneous abortions.

Background: Dynamic intraesophageal pressure (Pes) is used to estimate intrapleural pressure (Ppl) to calculate lung compliance and resistance. This study investigated the nonhuman primate Ppl-Pes tissue barrier frequency response and the dynamic response requirements of Pes manometers., Methods: In healthy monkeys and monkeys with acute lung injury undergoing ventilation, simultaneous Ppl and Pes were measured directly to determine the Ppl-Pes tissue barrier amplitude frequency response, using the swept-sine wave technique. The bandwidths of physiologic Pes waveforms acquired during conventional mechanical ventilation were calculated using digital low-pass signal filtering., Results: The Ppl-Pes tissue barrier is amplitude-uniform within the bandwidth of conventional Pes waveforms in healthy and acute lung injury lungs, and does not significantly attenuate Ppl-Pes signal transmission between 1 and 40 Hz. At Pes frequencies higher than conventional clinical regions of interest the Ppl-Pes barrier resonates significantly, is pressure amplitude dependent at low-pressure offsets, and is significantly altered by acute lung injury. Allowing for 5% or less Pes waveform error, the maximum Pes bandwidths during conventional ventilation were 1.9 Hz and 3.4 Hz for physiologic and extreme-case waveforms in healthy lungs and 4.6 Hz and 8.5 Hz during acute lung injury., Conclusions: In monkeys, the Ppl-Pes tissue barrier has a frequency response suitable for Ppl estimation during low-frequency mechanical ventilation, and Pes manometers should have a minimum uniform frequency response up to 8.5 Hz. However, the Ppl-Pes tissue barrier adversely affects the accurate estimation of dynamic Ppl at high frequencies, with varied airway pressure amplitudes and offsets, such as the Ppl encountered during high-frequency oscillatory ventilation.

Objective: To determine if measuring fetal abdominal fat antenatally using ultrasound can predict fetal growth restriction (FGR)., Methods: One hundred thirty-seven unselected women with singleton pregnancies had serial ultrasound scans at 20, 26, 31, and 38 weeks' gestation. Subcutaneous fat in the fetal abdomen was measured using the same section as the abdominal circumference (AC). Outcome measures were birth weight, neonatal morbidity, and ponderal index., Results: Infants with subcutaneous fat less than 5 mm at 38 weeks (n = 51) were almost five times more likely to have a birth weight below the 10th centile than those with subcutaneous fat of 5 mm or more (n = 75). The incidence of neonatal morbidity was significantly higher in infants with subcutaneous fat less than 5 mm, compared with those with subcutaneous fat of 5 mm or more (20% versus 8%, P < .05). Decreased subcutaneous fat was also associated with a high prevalence of low ponderal index, regardless of birth weight category., Conclusion: Measurement of fat in the abdominal wall is a simple technique with a sensitivity for predicting low birth weight similar to that of conventional sonography and might potentially predict FGR irrespective of fetal weight.

Objective: To determine the factors associated with subsequent intraepithelial neoplasia among patients who had cervical intraepithelial neoplasia grade III (CIN III) diagnosed on a specimen from previous large-loop excision of the transformation zone., Methods: We studied all large-loop excisions of the transformation zone performed between May 1991 and December 1993, inclusive. All cases of CIN III were identified. We followed up patients with cytology and colposcopy for 2 years after treatment for high-grade CIN. Findings at follow-up were analyzed., Results: A histologic diagnosis of CIN III was made in 225 patients. The lesion appeared incompletely excised in 105 patients (48.2%). In 76 cases (34.9%), CIN III was found at the endocervical margin. Of the 211 patients reviewed at 6 months, 18 (8.5%) had histologically proven CIN. The incidence of CIN was 16.5% after a report of incomplete excision, compared with 1.9% after a report of complete excision (P < .001). Furthermore, there was no subsequent CIN III in the complete-excision group. Of the 183 patients reviewed at 24 months, seven (3.8%) had histologically proven CIN. All cases of subsequent CIN were associated with dyskaryosis on follow-up cervical cytology., Conclusions: Positive margins increase the risk of treatment failure. Cytology alone may be adequate for follow-up when CIN III is completely excised.

This study investigated whether whole body resistance training would increase tolerance to lower body negative pressure (LBNP). Twelve males (age = 19.6 +/- 0.4 yr; mean +/- SD) underwent an acute, 12-wk program of upper and lower body resistance training (ART). Pre- and posttraining, the ART group and a control group (CON; N = 8; age = 25.4 +/- 2.4 yr) underwent LBNP tolerance tests and neck pressure-suction testing. Additionally, a group of chronically resistance-trained individuals (CRT group; N = 5; age = 22.4 +/- 0.9 yr) were tested. LBNP tolerance was increased in the ART group after training and the CRT group exhibited a significantly higher LBNP tolerance than the other groups. The ART group exhibited a decreased leg circumference change at the same absolute negative pressure at which tolerance occurred pretraining. This indicated a decreased fluid pooling after ART. The CRT group exhibited a "flattened" hypotensive portion of the carotid sinus-heart rate baroreflex curve, but this appeared to be due to the increased neck muscle mass of the subjects. We conclude that whole body ART increases LBNP tolerance possibly mediated through alterations in vascular compliance. CRT results in even greater LBNP tolerance with the responsible mediating mechanisms unclear.

The purpose of this study was to examine the hypothesis that dystocia in nulliparas is directly related to birth weight. The study was confined to the first 1000 nulliparas delivered in 1988 who went into labor after 37 weeks' gestation with a single live fetus and cephalic presentation. The management of labor was standardized. As birth weight increased, there was an increase in the mean duration of labor and of the second stage of labor, in the incidence of oxytocin augmentation, and in the incidence of both cesarean and forceps delivery for dystocia. The direct relationship between birth weight and the mean duration of labor was independent of gestation and oxytocin augmentation. These findings suggest that birth weight is an important factor in the development of dystocia in nulliparas.

Active management of labor was introduced as the standard policy for the care of nulliparas in labor in a London maternity hospital. The basis of this management is, first, a strict diagnosis of labor and second, the early diagnosis and prompt treatment of dystocia. This study describes the outcome in 1000 consecutive nulliparas who were actively managed. In this multiracial population, active management was associated with a decrease in the cesarean section rate, without any evidence of an increase in perinatal mortality or morbidity. The results indicate that active management can be safely applied outside of Ireland to reduce the incidence of cesarean childbirth. It is suggested that this approach to the management of dystocia in labor be evaluated in the United States in a randomized controlled trial.

Placental separation in the third trimester of pregnancy may be associated with coagulopathy, fetal distress, or intrauterine death. We report a case of vaginal bleeding due to placental separation at 17 weeks' gestation associated with disseminated intravascular coagulation. After treatment with blood, fresh frozen plasma, and fibrinogen, the pregnancy progressed uneventfully for another 12 weeks, when delivery by emergency cesarean section was performed.

One hundred patients with histologically confirmed cervical intraepithelial neoplasia suitable for ablative therapy were randomly allocated to treatment by either laser vaporization or laser excision conization under local anesthesia in the outpatient colposcopy clinic. The two methods were compared with respect to the immediate surgical complications, ease of performance, and long-term complications. They were comparable in most respects, and both were well accepted by the patients. Laser excision had the added advantage of providing further material for histologic examination to confirm the absence of invasion and the completeness of excision of the lesion.