contraction with that elicited by electrical stimulation during isokinetic releases. Two subjects were repeatedly tested. In the first series of experiments, exercising the quadriceps of one leg, the instantaneous power fell to about 50 % over the course of 2 min and remained constant for the rest of the exercise. For one subject the voluntary and electrically stimulated forces declined in parallel while for the second subject the voluntary force was 10 % less than the stimulated force at the end of the exercise. These results show that central fatigue represented a minor factor contributing no more than one-fifth of the total loss of power in these circumstances. 3. In a second series of experiments the subjects alternately contracted the quadriceps and the hamstrings of both legs in an exercise which had a high rating of perceived exertion and entailed considerable respiratory and cardiovascular effort. The time course and proportionate loss of power were very similar to those seen with the one-leg exercise and neither subject showed evidence of significant central fatigue. The pattern of force loss was very similar for the hamstrings. We conclude that, for determined subjects, afferent feedback from muscles, tendons and joints or from the respiratory and cardiovascular systems does not have a major role in inhibiting voluntary activation of the quadriceps during heavy exercise. 4. In both series of experiments the power output during electrically stimulated isokinetic contractions was reduced to 50% of the initial value after 2 min of exercise while the isometric force, measured immediately before the release, fell to only 75%. This suggests that fatigue affects isometric and shortening contractions to different extents and the loss of power may be due to a combination of factors, only one of which is evident in the loss of isometric force.
Early delivery is associated with prolonged ENT/LOS, suggesting elective delivery at <37weeks is not beneficial. Combined IABD/EABD or IABD/collapsed extra-abdominal bowel is suggestive of complex gastroschisis.
A modified Cybex II isokinetic dynamometer was used to evaluate the problems associated with measuring the concentric force-velocity characteristics of human knee extensor muscles. Three contraction protocols were investigated, simple voluntary contractions (VC); releases from maximal voluntary isometric contractions (VR) and releases from isometric femoral nerve stimulated contractions (FNR). Percutaneous stimulation of the quadriceps was unsuitable for dynamic contractions as the proportion of the muscle activated varied with the angle of knee flexion. Isometric length-tension relationships and isokinetic contractions at seven angular velocities between 0.5 and 5.2 rad.s-1 were recorded in five subjects. During isometric and slow dynamic contractions the voluntary forces were often greater than those obtained by femoral nerve stimulation, probably due to subjects stretching the rectus femoris during voluntary manoeuvres. It was found that the VC protocol produced acceptable isokinetic force recordings only at velocities below 3.1 rad.s-1 in most subjects whilst VR contractions resulted in unexpectedly low forces at velocities below 1.57 rad.s-1. Of the three techniques employed, FNR, although uncomfortable for subjects, provided the most accurate and reliable method of measuring force-velocity characteristics of knee extensor muscles. FNR contractions produced a force-velocity curve which showed a smooth decline in force with increasing velocity up to 5.2 rad.s-1. VC contractions appear to be an acceptable alternative for testing the muscles provided the angular velocity is less than 3.1 rad.s-1 and the subjects can be prevented from stretching the rectus femoris during the movement.
BackgroundWe report a process to identify and prioritise research questions in preterm birth that are most important to people affected by preterm birth and healthcare practitioners in the United Kingdom and Republic of Ireland.MethodsUsing consensus development methods established by the James Lind Alliance, unanswered research questions were identified using an online survey, a paper survey distributed in NHS preterm birth clinics and neonatal units, and through searching published systematic reviews and guidelines. Prioritisation of these questions was by online voting, with paper copies at the same NHS clinics and units, followed by a decision-making workshop of people affected by preterm birth and healthcare professionals.ResultsOverall 26 organisations participated. Three hundred and eighty six people responded to the survey, and 636 systematic reviews and 12 clinical guidelines were inspected for research recommendations. From this, a list of 122 uncertainties about the effects of treatment was collated: 70 from the survey, 28 from systematic reviews, and 24 from guidelines. After removing 18 duplicates, the 104 remaining questions went to a public online vote on the top 10. Five hundred and seven people voted; 231 (45%) people affected by preterm birth, 216 (43%) health professionals, and 55 (11%) affected by preterm birth who were also a health professional. Although the top priority was the same for all types of voter, there was variation in how other questions were ranked.Following review by the Steering Group, the top 30 questions were then taken to the prioritisation workshop. A list of top 15 questions was agreed, but with some clear differences in priorities between people affected by preterm birth and healthcare professionals.ConclusionsThese research questions prioritised by a partnership process between service users and healthcare professionals should inform the decisions of those who plan to fund research. Priorities of people affected by preterm birth were sometimes different from those of healthcare professionals, and future priority setting partnerships should consider reporting these separately, as well as in total.
The Foley catheter was found to be an effective agent for cervical ripening in both primiparas and multiparas and its use was not associated with any complications.
Human beta defensin 2 (HBD2) is an endogenous mucosal antimicrobial peptide (AMP) upregulated during infection and inflammation. HBD2 is encoded by the DEFB4 gene, which exhibits extensive copy number variation. Previous studies have demonstrated a relationship between HBD copy number and serum HBD2 protein levels; however, our current understanding of the influence of copy number on mucosal AMP function remains limited. This study explores the relationship between HBD copy number, cervicovaginal HBD2 protein levels and antimicrobial activity in 203 women with risk factors for preterm birth. We provide evidence that suggests HBD copy number modulates cervical antimicrobial immunity.
Spontaneous preterm birth (sPTB, delivery <37 weeks gestation), accounts for approximately 10% of births worldwide; the aetiology is multifactorial with intra-amniotic infection being one contributing factor. This study aimed to determine whether asymptomatic women with a history of sPTB or cervical surgery have altered levels of inflammatory/antimicrobial mediators and/or microflora within cervical fluid at 22–24 weeks gestation. External cervical fluid was collected from women with history of previous sPTB and/or cervical surgery at 22–24 weeks gestation (n = 135). Cytokine and antimicrobial peptides were measured on a multiplex platform or by ELISA. qPCR was performed for detection of 7 potentially pathogenic bacterial species. IL-8 and IL-1β levels were lower in women who delivered preterm compared to those who delivered at term (IL-8 P = 0.02; IL-1β P = 0.04). There were no differences in elafin or human beta defensin-1 protein levels between the two groups. Multiple bacterial species were detected in a higher proportion of women who delivered preterm than in those who delivered at term ( P = 0.005). Cervical fluid IL-8 and IL-1β and microflora have the potential to be used as biomarkers to predict sPTB in high risk women.
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