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Biomedical subjects

J Sleep

Publications and source records attributed to J Sleep.

10 recordsLinked to original sources
PubMed1992

Uncoupling of actin-activated myosin ATPase activity from actin binding by a monoclonal antibody directed against the N-terminus of myosin light chain 1.

The role of the N-terminal region of myosin light chain 1 (LC1) in actomyosin interaction was investigated using an IgG monoclonal antibody (2H2) directed against the N-terminal region of LC1. We defined the binding site of 2H2 by examining its cross-reactivity with myosin light chains from a variety of species and with synthetic oligopeptides. Our findings suggest that 2H2 is directed against the N-terminal region of LC1 which includes the trimethylated alanine residue at the N-terminus. In the presence of 2H2, the rate of actomyosin superprecipitation was reduced, although the extent was not. 2H2 caused a reduction in the Vmax of both myosin and chymotryptic S1(A1) actin-activated ATPase activity, while the Km appeared to be unaltered. The Mg(2+)-ATPase activity of myosin alone was also unaffected. Binding studies revealed that 2H2 did not prevent the formation of acto-S1 complex, either in the presence or in the absence of ATP, nor did it affect the ability of ATP to dissociate S1 from F-actin. Our findings suggest that the N-terminal region of LC1 is not essential for actin binding but is involved in modulating actin-activated ATPase activity of myosin.

Actins↗
PubMed1992

Research and the practice of midwifery.

During the past decade, the professional journals have contained numerous papers authored by nurses and nurse-researchers describing the gap which persists between research and clinical practice. Problems have been highlighted and challenges explored in the quest to discover ways of encouraging practitioners to become more aware of research evidence as a knowledge base for practice. Many of the identified issues may be transposed into a midwifery setting but other factors may be recognized which are specific to the practice of midwifery. This paper considers both conceptual and pragmatic issues in an attempt to explore the complexity of the influences which may affect the integration of research into midwifery practice.

Attitude of Health Personnel↗
PubMed1992

A randomized controlled trial to compare three types of fetal scalp electrode.

OBJECTIVES: To compare three scalp electrodes in respect of need for reapplication, trace quality and scalp trauma. DESIGN: Randomized controlled trial. SETTING: Maternity Unit, Royal Berkshire Hospital, Reading. PARTICIPANTS: 780 women in labour at term, with cephalic fetal presentation, deemed to require electronic fetal heart rate monitoring using a scalp electrode. INTERVENTIONS: Three types of fetal scalp electrode: Rocket-Rolon (double-helix spiral); Hewlett-Packard (double-helix spiral); and Surgicraft-Copeland (clip). MAIN OUTCOME MEASURES: Need for more than one electrode; reason for replacement; trace quality; scalp trauma; direct financial costs. RESULTS: Reapplication was significantly least likely in the Surgicraft-Copeland group (odds ratio vs Hewlett-Packard = 0.61, 95% CI 0.41-0.90; odds ratio vs Rocket-Rolon = 0.43, 95% CI = 0.29-0.62). This reflected a much lower rate of replacement because of detachment. The Hewlett-Packard was, however, least likely to be replaced because of poor trace quality. Interpretable traces were equally common, but trace quality tended to be superior in the Hewlett-Packard group. There was no serious scalp trauma. Difficulty removing the electrode was least often reported in the Hewlett-Packard group, and a mark on the scalp persisted least often in the Rocket-Rolon group. CONCLUSIONS: The Surgicraft-Copeland performed the best overall, and particularly in respect of attachment to the scalp. It appears to be the electrode of choice of the three tested.

Adult↗
PubMed1991

Nurse Education Tomorrow Conference 1990. The what and how of teaching research.

Within the last decade nurse educators have been required to introduce research into the curriculum of every pre- and post-registration programme. This has lead to a debate concerning what practitioners need to know about research and about the best way to teach the research component of any educational programme. Two main approaches may be identified: facilitating research awareness and learning research by 'doing'. Both approaches raise a number of logistical and ethical problems. Certain of these problems are compounded by the large numbers of nurses who may be required to undertake a research project as a course component. Moreover, the absence of research evidence about the most effective means of educating nurses to become discerning consumers of research leaves the teacher without a sound framework to guide educational practice. In the light of recent educational reforms, this paper considers the unprecedented opportunities for nurse and midwife teachers to explore the role of research in the curriculum and in teaching.

Attitude of Health Personnel↗
PubMed1989

Ultrasound and pulsed electromagnetic energy treatment for perineal trauma. A randomized placebo-controlled trial.

Ultrasound and pulsed electromagnetic energy therapies are increasingly used for perineal trauma sustained during childbirth. The study included 414 women with moderate or severe perineal trauma randomly allocated to receive active ultrasound, or active pulsed electromagnetic energy, or corresponding placebo therapies; the allocation was double-blind for each machine. Overall, more than 90% thought that treatment made their problem better. There were no clear differences between the groups in outcome either immediately after treatment, or 10 days or 3 months postpartum, other than more pain associated with pulsed electromagnetic energy treatment at 10 days. Bruising looked more extensive after ultrasound therapy but then seemed to resolve more quickly. Neither therapy had an effect on perineal oedema or haemorrhoids. The place of these new therapies in postnatal care should be clarified by further controlled trials before they become part of routine care.

Adult↗
PubMed1987

Activation of myosin ATPase by actin isolated from cultured BHK cells and the effect of gelsolin.

Activation of skeletal muscle myosin and myosin subfragment-1 (S1) by actin purified from the cytoplasm of cultured BHK cells was studied using the fluorescence of pyrene-labelled BHK F-actin and its quenching by S1 and by an enzyme-linked ATPase assay. At non-saturating concentrations, both muscle and BHK actin activated skeletal muscle myosin to the same degree: at 30 degrees C and an ionic strength of 108 mM, 1 microM actin approximately doubled the ATPase of myosin or of S1. The association between BHK actin and S1 was also followed in a fluorescence stop flow: the rate of ATP binding monitored by the loss of light scattering upon dissociation of actin was again the same for BHK and muscle actin. The similarity of activation of myosin ATPase by BHK and muscle actin at low actin concentrations (i.e. the similarity of Vmax/Km) suggests that both Vmax and Km are similar for the two types of actin. The effect of varying filament length on actin activation of myosin ATPase was examined using pig plasma or BHK gelsolin to regulate the length. For both types of actin, maximum enhancement of the actomyosin ATPase activity was observed at an actin/gelsolin ratio of about 30:1, whereas inhibition was observed at lower ratios. Both activation and inhibition of actomyosin ATPase were apparent in the absence or presence of calcium; differences were observed only in the extent and the time course of the effect.

Actins↗