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We examined the ability of patients with spinal cord injury to undergo adaptations to chronic exercise training (cycle ergometry) invoked by functional electrical stimulation (FES) of the legs. Nine such patients performed incremental and constant work rate exercise before and after exercise training. Exercise sessions averaged 2.1 +/- 0.4/wk, and consisted of 30 min/session of continuous FES recumbent cycling with increasing work rate as tolerated. Peak VO2 and peak work rate significantly improved with training. Peak VO2 was significantly correlated with peak heart rate both before and after training (r = 0.97 pre and 0.85 post, P < 0.01 for both). The time course of the VO2, VCO2 and VE responses to constant-load exercise (unloaded cycling) and in recovery (mean response time MRT) were very long prior to training, and became significantly faster following training. However, there was no correlation between percentage improvement in either MRTon or MRToff for VO2 and the percentage increase in peak VO2. Exercise tolerance in these patients with spinal cord injury appears to be a direct function of the ability to increase heart rate. Further, exercise training can elicit significant improvements in both exercise tolerance and in gas exchange kinetics, even when performed only twice per week. However, these improvements may be accomplished by different mechanisms.

Eight males with spinal cord injury (SCI) participated in an exercise training program using neuromuscular electrical stimulation (NMES) leg cycle ergometry. Each subject completed a minimum of 24 (mean +/- SD = 38.1 +/- 17.2) 30-minute training sessions over a 19-week period. The initial work rate (WR) of 0 watts (W) of unloaded cycling was increased when appropriate with subjects exercising at 11.4 +/- 3.7 W (range = 6.1 W-18.3 W) at the end of the training program. Randomized block repeated measures ANOVA was used to compare pretraining and posttraining peak physiologic responses during graded NMES leg cycle tests and subpeak physiologic responses during 10 minutes of NMES leg cycle exercise at an absolute WR (0 W). A significant (P < or = 0.05) increase was observed for peak VO2; (+10%, 1.29 +/- 0.30 to 1.42 +/- 0.39 1.min-1). No other statistically significant differences were noted for any other peak variable (VCO2, VO2 ml.kg-1 min-1, VE, WR, HR, RER) pre- to posttraining. During submaximal NMES leg cycle testing, a significant decrease was noted for RER (-9.2%, 1.19 +/- 0.14 to 1.08 +/- 0.09). No other submaximal variable (VO2 1.min-1, ml.kg-1.min-1, VCO2, HR, VE) showed significant changes as a result of the training. Although the improvement in peak VO2 was not as dramatic as those reported in previous studies, it appears that NMES leg cycle training performed two times per week can significantly enhance cardiorespiratory fitness.

The pregnancy outcomes on cases of Down syndrome diagnosed prenatally in which the mother did not elect termination were evaluated in data reported to a comprehensive Register of Down syndrome for England and Wales for 1989-94. In the 168 cases in which placental biopsy was not used, the overall rate of spontaneous loss was 35%, but this figure masks considerable heterogeneity by gestational stage at ascertainment. Data on ages at diagnostic procedure and on pregnancy termination enabled a more precise survival analysis. The loss rates were approximately 50% for those fetuses ascertained at 15-17 completed wk, 43% at 18 wk, 31% at 19 wk, 25% at 20 wk, and then a leveling off at approximately 20%-25% for fetuses ascertained at 21-28 completed wk. For fetuses ascertained prior to 18 wk, there was no evidence that maternal age was associated with fetal loss, consistent with earlier reports. At 18 wk and after, however, maternal age was on the average approximately 3 years greater in fetuses that were lost. Comparison of successive gestational birth cohorts provided no evidence in these 168 cases that the diagnostic procedure itself had any effect on loss or that selective ascertainment of mothers in risk of loss had any effect on the results. In contrast, in the 21 cases in which placental biopsy had been undertaken, the overall loss rates were not only higher when appropriate comparisons could be made, but there was some evidence for selective ascertainment and/or procedure-associated losses.(ABSTRACT TRUNCATED AT 250 WORDS)

We examined the kinetics of VO2, VCO2, and VE following the onset of unloaded leg cycling, and in recovery, in six patients with spinal cord injury (SCI). Exercise was produced by functional electrical stimulation (FES) of the quadriceps, hamstrings, and gluteal muscles. End-exercise VO2 (1.03 +/- 0.16 l.min-1), VCO2 (1.20 +/- 0.22 l.min-1) and VE (41 +/- 10 l.min-1) were elevated compared to values typically seen in healthy ambulatory subjects performing similar unloaded cycling. Mean response times for the on transients (MRTon) were both long and variable across subjects for VO2 (165 +/- 62 s), VCO2 (173 +/- 58 s), and VE (202 +/- 61 s). Recovery kinetics showed much less intersubject variability, and for five of six subjects were faster than the equivalent exercise MRT for all three variables (MRToff for VO2 of 103 +/- 28 s, VCO2 136 +/- 20 s, and VE 144 +/- 34 s), but P > 0.05 for all three. Size of the O2 deficit (1.96 +/- 0.90 l) and end-exercise lactate (7.05 +/- 1.65 mmol.l-1) were similar to values reported for healthy sedentary subjects performing maximal voluntary exercise, but the end-exercise heart rate (102 +/- 16 bpm) was lower than expected for this intensity of exercise. In conclusion, FES-induced unloaded cycling leads to exaggerated responses of pulmonary gas exchange and long time constants in patients with SCI. The delayed kinetics may be due in part to a blunted increase in heart rate in addition to severe deconditioning.

Objective: To investigate changes in the numbers of Down's syndrome births and terminations of pregnancies from 1989 to 1993., Design: Data from a national register of cytogenetic diagnoses of karyotypes associated with Down's syndrome were analysed to obtain observed numbers of births and terminations of pregnancies known to be affected. Allowance was made for those cases diagnosed prenatally for whom the eventual outcome of the pregnancies had not yet been ascertained., Results: There has been an increase over the study years in the number of cytogenetic diagnoses of Down's syndrome from 1063 in 1989 to 1137 in 1993, despite an overall fall in births in England and Wales. This is largely due to the increase in antenatal screening and diagnosis, but in part also due to the rise in numbers of pregnancies at increased maternal ages. The rise in prenatally diagnosed cases, of which 92% end in termination, has been accompanied by a fall in both the estimated numbers of affected live births, from 764 in 1989 to 615 in 1993, and the rate per 1000 total live births in the same years from 1.1 to 0.9., Conclusions: Better and speedier information on the outcome of prenatally diagnosed cases of congenital anomalies such as Down's syndrome would improve the quality of information available for those auditing genetic services or those planning for the care of survivors.

The national register of chromosomal anomalies that lead to Down's syndrome has enabled the monitoring of change in prenatal diagnosis for this condition, and the factors which affect the change. The proportion of cases of cytogenetically diagnosed Down's syndrome in England and Wales detected prenatally rose to 46% in 1991-2 from 31% in 1988-9, a 1.5-fold increase (95% confidence interval 1.3 to 1.7). The increase was confined to mothers under 40 years and was due to the introduction of screening by maternal serum analysis and ultrasound. Over a quarter of affected pregnancies in women aged 25-29 were detected prenatally in 1991-2 compared with less than 10% in 1988-9. Analysis of the data showed regional differences in prenatal diagnosis rates, and in the length of time elapsing between the diagnostic test and termination of an affected pregnancy. An inexplicable finding was that this period varied with the sex of the fetus, being on average a day longer for females than for males.

The effects of 5 wk of equivalent intensity, 85-90% maximum heart rate (MHR), run-only (N = 6) vs cycle/run (N = 5) training were evaluated in moderately fit runners, mean VO2max of 55.2 ml.kg-1.min-1, 19-35 yr old, on maximal treadmill (TM) and cycle ergometer (CE) testing, 5000-m and 1609-m run performances, and submaximal measures while treadmill running. Subjects participated in either 4 d.wk-1 of run-only or alternating run and cycle training. Both groups significantly improved TM VO2max (P < 0.05), CE VO2peak (P < 0.01), and 5000-m (P < 0.01) and 1609-m (P < 0.05) run times with no significant differences between the groups. The TM VO2max pre/post values were 55.3 +/- 3.0 to 58.2 +/- 3.0 and 55.6 +/- 3.8 to 58.9 +/- 2.4 ml.kg-1.min-1 for the run group and cross-trained group, respectively. Posttraining submaximal treadmill running showed statistically significant pace increases of 18.7 (run) and 16.1 (cycle/run) m.min-1 with similar heart rate, blood lactate, and RQ values as pretraining. Results indicate that 5 wk of either mode of training can significantly improve aerobic capacity and run performance.

Physically active college age women were evaluated to determine the effects of 9 wk of stair-climbing (Stairmaster Gauntlet) vs run training on 2414-m run time and treadmill measured aerobic capacity (VO2max) and submaximal physiological parameters. Subjects were randomly assigned to a stair-climbing (STAIR N = 11) (43.8 +/- 1.5 ml.kg-1.min-1) (mean +/- SEM) or run training (RUN N = 12) (44.2 +/- 1.8) group, training 4 d.wk-1 at 70-80% of maximum heart rate (MHR) for 30 min progressing to 85-90% MHR for 45 min. The STAIR group significantly increased (P < 0.01) their VO2max by 12% and decreased (P < 0.01) their 2414-m run time of 12.8 min by 8%. The RUN group increased (P < 0.01) their VO2max 16% and decreased run time (P < 0.01) 11% from 13.1 min. Submaximal treadmill runs at the same speed and grade demonstrated significant decreases in %VO2max and % MHR (P < 0.01) for both groups. The data support the use of stair-climbing exercise as an alternative mode to running with similar treadmill and running performance results subsequent to 9 wk of training.

Flow cytometry has been used to detect in vivo expression of rubella antigens on human leucocytes. Sequential samples of peripheral blood were obtained from four volunteers with naturally acquired rubella and five persons immunised with RA27/3 rubella vaccine. Leucocytes were stained for rubella antigens using a pool of rubella monoclonal antibodies. Rubella antigens were detected on the leucocytes of all four volunteers with naturally acquired rubella between 1 and 13 days after onset of illness. Viral antigens were expressed more frequently on the monocyte (9-51%) than the lymphocyte (less than 1-4%) and granulocyte (less than 1-3%) populations. Among the vaccines, rubella antigens were detected on the leucocytes of four of the five volunteers between 5 and 12 days after immunisation. The expression of viral antigens was more transient and the proportion of cells exhibiting rubella-specific fluorescence considerably lower following vaccination (1-12%) than natural infection (9-51%). Our results demonstrate that flow cytometry provides a rapid and sensitive analytical technique for detecting viral antigens on leucocytes from infected persons. Leucocytes may play an important role in the pathogenesis of rubella infection.