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Biomedical subjects

L Page

Publications and source records attributed to L Page.

At least 19 recordsLinked to original sources

Characterizing the peak in the cosmic microwave background angular power spectrum

A peak has been unambiguously detected in the cosmic microwave background angular spectrum. Here we characterize its properties with fits to phenomenological models. We find that the TOCO and BOOM/NA data determine the peak location to be in the range 175-243 and 151-259, respectively (at 95% confidence) and determine the peak amplitude to be between approximately 70 and 90 &mgr;K. The peak shape is consistent with inflation-inspired flat, cold dark matter plus cosmological constant models of structure formation with adiabatic, nearly scale invariant initial conditions. It is inconsistent with open models and presents a great challenge to defect models.

Journal Article↗

Developmental characterization of the gene for laminin alpha-chain in sea urchin embryos.

We describe the isolation and characterization of a cDNA clone encoding a region of the carboxy terminal globular domain (G domain) of the alpha-1 chain of laminin from the sea urchin, Strongylocentrotus purpuratus. Sequence analysis indicates that the 1.3 kb cDNA (spLAM-alpha) encodes the complete G2 and G3 subdomains of sea urchin a-laminin. The 11 kb spLAM-alpha mRNA is present in the egg and declines slightly in abundance during development to the pluteus larva. The spLAM-alpha gene is also expressed in a variety of adult tissues. Whole mount in situ hybridization of gastrula stage embryos indicates that ectodermal and endodermal epithelia and mesenchyme cells contain the spLAM-alpha mRNA. Immunoprecipitation experiments using an antibody made to a recombinant fusion protein indicates spLAM-alpha protein is synthesized continuously from fertilization as a 420 kDa protein which accumulates from low levels in the egg to elevated levels in the pluteus larva. Light and electron microscopy identify spLAM-alpha as a component of the basal lamina. Blastocoelic microinjection of an antibody to recombinant spLAM-alpha perturbs gastrulation and skeleton formation by primary mesenchyme cells suggesting an important role for laminin in endodermal and mesodermal morphogenesis.

Animals↗

Clinical interventions and outcomes of One-to-One midwifery practice.

BACKGROUND: Changing Childbirth became policy for the maternity services in England in 1994 and remains policy. One-to-One midwifery was implemented to achieve the targets set. It was the first time such a service had been implemented in the Health Service. An evaluation was undertaken to compare its performance with conventional maternity care. METHODS: This was a prospective comparative study of women receiving One-to-One care and women receiving the system of care that One-to-One replaced (conventional care) to compare achievement of continuity of carer and clinical outcomes. The evaluation took place in The Hammersmith Hospitals NHS Trust, the Queen Charlotte's and Hammersmith Hospitals. This was part of a larger study, which included the evaluation of women's responses, cost implications, and clinical standards and staff reactions. The participants were all those receiving One-to-One midwifery practice (728 women), which was confined to two postal districts, and all women receiving care in the system that One-to-One replaced, in two adjacent postal districts (675 women), and expecting to give birth between 15 August 1994 and 14 August 1995. Main outcome measures were achievement of continuity of care, rates of interventions in labour, length of labour, maternal and infant morbidity, and breastfeeding rates. RESULTS: A high degree of continuity was achieved through the whole process of maternity care. One-to-One women saw fewer staff at each stage of their care, knew more of the staff who they did see, and had a high level of constant support in labour. One-to-One practice was associated with a significant reduction in the use of epidural anaesthesia (odds ratio (OR) 95 per cent confidence interval (CI) = 0.59 (0.44, 0.80)), with lower rates of episiotomy and perineal lacerations (OR 95 per cent CI = 0.70 (0.50, 0.98)), and with shorter second stage labour (median 40 min vs 48 min). There were no statistically significant differences in operative and assisted delivery or breastfeeding rates. CONCLUSIONS: This study confirms that One-to-One midwifery practice can provide a high degree of continuity of carer, and is associated with a reduction in the rate of a number of interventions, without compromising safety of care. It should be extended locally and replicated in other services under continuing evaluation.

Adult↗

The use of clinical audit in evaluating maternity services reform: a critical reflection.

The clinical evaluation described here, using a casenote study, was part of a larger study evaluating the changes made to part of the maternity services in one NHS Trust, in response to the recommendations of Changing Childbirth (Department of Health 1993a). Results of the audit showed no evidence of a lowering of clinical standards within the study group and provided reassurance that a radical change in the model of care, with greatly enhanced continuity of career, an emphasis on community-based and midwifery-led care, and some reductions in labour interventions, could be implemented without compromising safety of care. The audit process raised a number of methodological problems which will need to be addressed in developing audit approaches which are able to reflect quality of care. It is important to recognize that the record of care is not a direct mirror of the care provided but a secondary source, kept for different purposes and designed to cover a different set of priorities from those which audit may seek to capture. The audit approach used in this study will be modified in continuing evaluation of the service as it moves from a pilot stage towards providing a mainstream service. Additional methods, including direct observation of care, will be employed in a sample of cases in order to assist in interpretation of audit findings.

Continuity of Patient Care↗

Evaluation of one-to-one midwifery: women's responses to care.

BACKGROUND: One-to-one midwifery was a demonstration project introduced into a London-based maternity service in 1993 to put into practice the new government policy for maternity services in England. Evaluation was integral to the development of the project. METHODS: The evaluation of women's responses was conducted between August 1994 and August 1995 based on a longitudinal, self-completion questionnaire, interviews, and focus groups. Women in the study group (n = 728) received the new service and women in the control group (n = 675) received conventional care. The study design integrated quantitative and qualitative methods and went beyond a simple estimation of satisfaction with care. RESULTS: Satisfaction with antenatal and birth care was generally high, but study group women showed more positive responses overall. Both groups showed a preference for continuity of caregiver, but expectations were higher in the study group (72% of the study group and 42% of the control group preferred to see one caregiver). Both groups had less satisfied responses to hospital postnatal care (50% study and 54% control group were very satisfied). Study group women showed greater preparedness for birth than control group women (18% vs 12% "very well prepared") and for the time after the baby's birth (26% vs 15% "very prepared"). CONCLUSIONS: The study demonstrated that women were more satisfied with the one-to-one model of care. Taken together with the results of clinical and economic audit and professional responses, the evaluation suggests that this model should be developed and evaluated further to gain a greater understanding of women's needs of the maternity service.

Adult↗

Bladder augmentation can be problematic with renal failure and transplantation.

Ten consecutive patients with failure of urinary bladder augmentation (UBA) performed either prior to or after reaching end-stage renal disease (ESRD) were studied. Seven patients developed increased hydroureteronephrosis, infectious complications, and advanced to ESRD after UBA. The mean time to development of ESRD in patients who had UBA performed with moderate chronic renal failure (CRF) was 1.8 years. The UBAs in all seven patients were taken down prior to transplantation. Subsequently, five of these UBA-takedown patients have received kidney grafts and all have stable, good renal function. Three patients had their UBA performed after they reached ESRD, in preparation for renal transplantation. All three of these patients experienced recurrent urosepsis following transplantation, resulting in death in one patient and loss of graft in another. The third patient will undergo takedown of the UBA. This study suggests that UBA may possibly not be the best option for patients with moderate CRF and those awaiting transplantation.

Adolescent↗

Reclaiming midwifery.

Explore the source record for details and available documents.

Continuity of Patient Care↗

Quantitative cell line based bioassays for human cytokines.

Research in cytokine biology is ever increasing and it is clear that cytokines are involved in a wide range of pathological and physiological processes. The validity of such research relies heavily on the appropriate measurement of levels of cytokines in various biological samples. Amongst the currently available methods for measuring cytokine levels, it is only the biological assay of samples that can directly provide estimates of biologically active cytokines present in test samples. Of the several bioassay systems available for detecting cytokines, cell line based bioassays are the easiest to perform and provide the most precise and accurate data. The suitability of any cell line for bioassaying a particular cytokine depends on several criteria such as sensitivity, ease of growth maintenance, and cytokine specificity. The design and analysis of cell line bioassays is also important in providing valid estimates of cytokine levels. We review the most useful cell lines currently available for bioassaying cytokines and discuss the design advantages and limitations of cytokine bioassays.

Animals↗

Change and power in midwifery.

Midwives are experiencing problems in playing their full part in the maternity services and the communities in which they practice. Mothers, babies, and families require greater care from these caregivers for healthier pregnancy and birth outcomes. Change to renew the power, skills, and knowledge of midwives is evident in many parts of the world. Processes of change require an examination of the purpose of midwifery. The starting point of change is an awareness of the meaning of birth to individuals and society, and of the role of midwives in supporting families around the time of birth. Midwives should use their power to resolve the considerable problems facing childbearing families, and to enrich the event.

Female↗

Transforming growth factor-beta 1 blocks interleukin 4 induced cell proliferation by inhibiting a protein tyrosine phosphatase essential for signal transduction.

Transforming growth factor-beta 1 (TGF-beta 1) is a cytokine which exhibits pleiotropic effects on many cell types and cellular systems. TGF-beta 1 has been shown to play a modulatory role in haematopoiesis and immunoregulation, expressed through its ability to inhibit the activities induced by other cytokines; however, the mechanisms underlying this activity are currently unclear. The potency of this activity varies according to the selected stimulatory cytokine and we have found that the proliferation of leukaemic cell lines induced by interleukin 4 (IL-4) is particularly sensitive to inhibition by TGF-beta 1 and provides a useful model to study the mechanism of action of TGF-beta. We have previously shown that IL-4 mediated mitogenic signal transduction in human systems involves the induction of phosphatase activity leading to the dephosphorylation of an 80-kDa protein (p80). We now show that TGF-beta 1 inhibits IL-4 induced dephosphorylation of p80 in a dose responsive manner closely correlated with its ability to inhibit the biological activity of IL-4. This suggests that TGF-beta 1 is inhibiting the same protein-tyrosine-phosphatase required by IL-4 to transduce its mitogenic signal. The biochemical mechanism underlying the biological activity of TGF-beta 1 in inhibiting IL-4 bioactivity is therefore the blocking of post receptor binding signal transduction processes.

Amino Acids↗