Multiple copies of beta-lactoglobulin promoter do not function as LCR

Increasing the number of transcription factor binding sites within a construct can enhance expression. In an attempt to create a synthetic locus control region for mammary expression, we have generated beta-lactoglobulin-reporter constructs with multiple copies of the cluster of transcription sites normally located within the proximal promoter. These constructs were functionally tested by stable transfection of mammary epithelial cells in vitro and in transgenic mice in vivo. Rather than enhancing expression, multimerisation of the promoter region acted neither in vivo nor in vitro to enhance expression. Indeed, its presence reduced expression. This failure to enhance expression was reflected in the inability of this region to form a DNaseI hypersensitive site autonomously in mammary chromatin in vivo. It is implicit from our study that not all combinations of transcription factor binding sites will enhance transcription.

Calcium channel blockers, ACE inhibitors, and the risk of cancer in hypertensive patients: a report from the Department of Health Hypertension Care Computing Project (DHCCP)

OBJECTIVE

Recent studies have shown inconsistent results on the risk of cancer in hypertensive patients using calcium channel blockers (CCBs) and angiotensin-converting enzyme (ACE) inhibitors. We investigated a large number of patients from the Department of Health Hypertension Care Computing Project (DHCCP) observational database treated with these drugs for hypertension to see whether the use of CCBs for hypertension is associated with an increased risk of cancer mortality and the use of ACE inhibitors with a reduction.

DESIGN

Matched case-control study and a longitudinal study of survival from 1 year after presentation.

PATIENTS

A total of 11663 patients treated for hypertension from 1971 through 1987. They were recruited on presentation to one of the hospital hypertension clinics or general practices involved.

MAIN OUTCOME MEASURES

Death with any mention of cancer on the death certificate in patients treated with an Index drug group; CCBs, ACE inhibitors, beta adrenergic blocking drugs (BBs), or receiving a diuretic. The treatment groups were mutually exclusive.

RESULTS

A total of 391 cases of cancer were matched with 1050 controls. In this case-control study the adjusted relative risk estimate in comparison to diuretic treatment for CCBs was 0.79 (95% CI 0.37 to 1.69), and for CCBs plus a diuretic, 1.05 (0.65 to 1.69). Non-significant results were also observed for ACE inhibitors (1.48 (0.43 to 5.1), and 1.40 (0.56 to 3.50) with a diuretic), and also for the BB and methyldopa groups. In the longitudinal survival study, the adjusted relative risk estimate for CCBs was 1.1 (0.60 to 1.94) and 1.0 (0.53 to 1.86) for CCBs plus a diuretic, and for ACE inhibitors 1.33 (0.37 to 4.76) and 1.47 (0.67 to 3.23), respectively.

CONCLUSIONS

In this population there was no increased cancer mortality with the use of CCBs and a relative risk greater than 1.7 to 2.0 was excluded with 95% confidence. The suggestion that ACE inhibitors reduce cancer mortality was not supported with best estimates of relative risk of 1.3 to 1.5 and exclusion of values less than 0.4 to 0.7.

Nurse-led weaning from ventilation and extubation in the paediatric cardiothoracic intensive care unit

An idea involving the expansion of the role of the paediatric intensive care nurse and the promotion of enhanced quality patient care is presented. A point prevalence study was conducted to investigate practices in weaning from ventilation in children after cardiac surgery. The development of a clinical protocol, audit of practice, education and training and implementation of a change in practice are discussed. Recommendations for future research are made.

Development of a district Cord Blood Bank: a model for cord blood banking in the National Health Service

The Bristol Cord Blood Bank was established as a pilot project within existing health services to establish cost-effective recruitment, collection and processing suitable for use in the NHS should cord blood become a routine source of haemopoietic stem cells for transplantation in the UK. An important aim of the project was to evaluate the feasibility of establishing a midwifery-based collection network, thus utilising expertise already in place. Collection was performed on the delivery suite immediately after the placenta was delivered. The clinical experience of the midwife collector/counsellors allowed rapid pre-collection assessment of the condition of the cord and placenta. This prevented collection attempts from diseased or otherwise damaged placentas, leading to conservation of resources by preventing collection of most small volume donations. The bank was established within the National Blood Service, Bristol Centre to achieve Good Manufacturing Practice standards and ensure that processing was subject to the same stringency required for other sources of haemopoietic stem cells. Cord blood is an expensive resource. By utilising existing expertise in district Obstetric and National Blood Services, the Bristol Cord Blood Bank may serve as a model for health economic evaluation of cord blood banking of volunteer donations within the NHS.

Matrix attachment region regulates basal beta-lactoglobulin transgene expression

Nuclear matrix attachment regions (MAR) have been implicated in the regulation of gene expression. We have identified a region within the proximal 3'-flanking sequences of the ovine beta-lactoglobulin (betalg) gene that interacts with the nuclear matrix in vitro. No equivalent region was detected in the 5' flanking region. We have investigated the role of this element in regulating betalg expression in vitro and in vivo. Removal of the MAR did not affect the frequency of betalg transgene expression at the mRNA level, but betalg transgenes that lacked the MAR were expressed at a lower level than wild-type betalg transgenes. In neither in-vitro HC11 transfection experiments nor transgenic mice was hormonal induction of betalg expression significantly affected by MAR removal. Nuclear run-on analysis demonstrated that the impaired basal expression of betalg transgene loci lacking the MAR was due to a reduced transcription rate. Thus, the single MAR enhances the basal transcriptional potential of the betalg gene.

The carvedilol hibernation reversible ischaemia trial, marker of success (CHRISTMAS) study. Methodology of a randomised, placebo controlled, multicentre study of carvedilol in hibernation and heart failure

BACKGROUND

Carvedilol reduces mortality and improves symptoms and ejection fraction in ischemic heart failure, but its mode of action is not well defined and not all patients respond to treatment. The aim of the CHRISTMAS (Carvedilol Hibernation Reversible Ischaemia Trial, Marker of Success) study is to examine whether hibernation may be a significant factor determining this response. This paper describes the methodology and the rationale for the choice of the nuclear cardiology and echocardiography imaging techniques used in the study.

METHODS AND RESULTS

The CHRISTMAS study is a double-blind, randomised, parallel group, multinational study of oral carvedilol versus placebo in patients with chronic stable heart failure due to left ventricular systolic dysfunction from coronary artery disease. The study aims to randomise 400 patients who are on optimal treatment. Two parallel groups will be randomised to carvedilol or placebo, namely 200 with hibernating myocardium at baseline and 200 matched patients without. The presence of hibernation is defined from a mismatch between regional contractile function and regional viability, measured by echocardiography (severe segmental asynergy) and nitrate prepared resting Tc99m-MIBI myocardial perfusion imaging (segmental activity >60%). The primary treatment-related end-point of the study is the comparison of the mean change, from baseline to the final visit, in radionuclide-determined left ventricular ejection fraction in patients on placebo with those on carvedilol, between the groups designated as hibernating and non-hibernating. Other end-points being examined include the prevalence of hibernation in heart failure, the relationship between the volume of hibernating myocardium and the ejection fraction response, the prevalence of reversible ischemia in heart failure, and the comparison of echo with gated SPECT. To date, 303 patients have been screened and 251 patients randomised in the study. The study aims to report in 2000.

CONCLUSIONS

The CHRISTMAS study addresses the issue of whether the presence of hibernation is a predictor of the ejection fraction response to carvedilol in heart failure. It also examines the potential role of medical therapy in hibernation as well as a number of other end-points. The study may potentially lead to an important new role for nuclear cardiology in heart failure, and demonstrates important synergy between cardiac imaging and the pharmaceutical industry.

Implementation of an oral care standard for leukemia and transplantation patients

The purpose of this project was to develop an oral care standard on two nursing units in a university hospital where care was given to patients undergoing bone marrow or stem cell transplantation (BMSCT) and other treatments for leukemia. Strategies used in this interdisciplinary effort included collaboration, consultation, education, and evaluation. In the collaboration phase, a core group of nurses talked with staff about current practices, reviewed literature and published standards, examined protocols from other institutions, decided on goals, and developed the standard. Consultation with a dentist, pharmacist, and physician occurred before completion of the standard. The education phase included in-service sessions for nurses and technicians. The evaluation phase, which occurred in two phases, focused on checking to see if the goals had been met, including tolerability and adherence. The first phase allowed identification of problem areas and subsequent revisions, whereas the second phase evaluated adherence at a later time point. Overall, most of the patients adhered to the standard. Future implications include specific recommendations such as an emphasis on oral care, documentation, and patient and staff education. This project is an example of how nurses addressed the challenge of implementing an acceptable oral care standard to decrease patients' oral complications and distress.

Spectrophotometric measurement of experimental brain injury

Freshly sampled brain tissue exposed to 2,3,5-triphenyltetrazolium chloride (TTC) acquires a red color because mitochondrial enzymes reduce the colorless TTC to a red, water-insoluble formazan deposit. Pan-necrotic areas remain uncolored, which enables quantitation of experimental brain injury by optical scanning and image analysis of serial slices to determine the relative volume of red versus infarcted, non-stained, tissue. The accuracy of this method can be challenged, however, when infarction is accompanied by areas of partial, scattered injury where differences in coloration are difficult to see or quantify. We tested the feasibility of measuring scattered injury using a principle which underlies standard assays for in vitro cell survival, namely extracting deposited formazan with a solvent and measuring its level by spectrophotometry. Anesthetized, adult Sprague Dawley rats were subjected to 12 min of cerebral ischemia to produce selective, delayed neuronal death in hippocampus, striatum and cortex. Some rats also received 6 h of whole-body hypothermia treatment (31.5-32.5 degrees C) immediately after ischemia. Ischemia rats and non-operated controls were sacrificed 1 week later. Hippocampus and portions of cerebrum were incubated 90 min in a 2% TTC solution and then soaked in a measured volume of 50:50 ethanol and dimethylsulfoxide to extract the red formazan product. Spectrophotometric measurements of the extract showed a diminished formazan coloration (absorbance/g brain) in all samples from the untreated ischemia group compared to non-operated controls. This apparent brain injury was attenuated in the group of ischemia rats that received hypothermia treatment. We conclude that solvent extraction and spectrophotometric quantitation of formazan has potential utility as an objective way to index experimental brain injury even if this is diffuse in nature and not amenable to measurement by conventional image analysis techniques.

Dopamine agonist therapy in hyperprolactinemia

Introduction of the dopamine agonist bromocriptine heralded a major advance in the management of hyperprolactinemic disorders. Although its side effects of nausea, dizziness and headache and its short elimination half-life are limiting factors, its efficacy established it as a reference compound against the activity of which several dopamine agonists, like pergolide, lysuride, metergoline, terguride and dihydroergocristine, fell by the wayside. More recently, two new agents, cabergoline and quinagolide, have been introduced and appear to offer considerable advantages over bromocriptine. Cabergoline, an ergoline D2 agonist, has a long plasma half-life that enables once- or twice-weekly administration. Quinagolide, in contrast, is a nonergot D2 agonist with an elimination half-life intermediate between those of bromocriptine and cabergoline, allowing the drug to be administered once daily. Comparative studies indicate that cabergoline is clearly superior to bromocriptine in efficacy (prolactin suppression, restoration of gonadal function) and in tolerability. In similar studies, quinagolide appeared to have similar efficacy and superior tolerability to that of bromocriptine. Results of a small crossover study indicate that cabergoline is better tolerated, with a trend toward activity superior to that of quinagolide. In hyperprolactinemic men and in women not seeking to become pregnant, cabergoline may be regarded as the treatment of choice.

Practitioner-centred research: an evaluation of the implementation of the bedside hand-over

A practitioner-based enquiry (PBE) or 'practitioner-centred-research' (Rolfe 1998), was undertaken using action research to examine the concept of 'nursing hand-over'. The move away from the traditional style of hand-over (which involved either one or two people verbally relaying 'all' information to those nurses coming onto duty) to a hand-over that is based at the bedside with the patient and involves the patient and only those nurses accountable for that individual's care, was the focus of the study reported here. The study was carried out on a medical ward for people aged 65 and over and aimed to identify whether after 6 months (post-implementation of the new style of hand-over) all staff felt that key issues identified in a 3-month evaluation based primarily on quantitive data collection, had been addressed by using an action research methodology. Although reference will be made to the 3-month evaluation as it formed a vital part of the process of assessing the change to practice, the focus of the analysis will be the evaluation that took place after 6 months. The key objective was to assess the effectiveness of the planned implementation of hand-over at the bedside and the subsequent change to current nursing practice.

Guidelines for the diagnosis and treatment of hyperprolactinemia

Hyperprolactinemia is the most common endocrine disorder of the hypothalamic-pituitary axis. While it can occur in men, it occurs more commonly in women. The prevalence of hyperprolactinemia ranges from 0.4% in an unselected normal adult population to as high as 9-17% in women with reproductive disorders. There are many possible causes of hyperprolactinemia, falling into three general categories: physiologic, pharmacologic and pathologic. When specific treatable underlying causes have been eliminated and in cases of severe hyperprolactinemia, the most likely cause is a prolactin (PRL)-secreting pituitary adenoma. Microadenomas should be treated medically, with a dopamine agonist, if there is an indication for therapy (such as amenorrhea, infertility or bothersome galactorrhea). If there is no indication for therapy, microadenomas may be followed conservatively, as growth is uncommon. Macroadenomas may grow larger; medical therapy is recommended initially, with neurosurgical evaluation reserved for specific clinical situations, such as failure of medical therapy and evidence of mass effect despite medical therapy. In the United States, the dopamine agonists indicated for treatment of hyperprolactinemia are bromocriptine and cabergoline. Bromocriptine is usually given once or twice daily, while cabergoline has a long duration of action and is given once or twice weekly. Results of comparative studies indicate that cabergoline is clearly superior to bromocriptine in efficacy (PRL suppression, restoration of gonadal function) and tolerability.

Clinical management of prolactinomas

Prolactinomas are benign, sporadic pituitary tumours that typically present with amenorrhoea and galactorrhoea in women, and hypogonadism and space-occupying effects in men. Hyperprolactinaemic hypogonadism in either sex is associated with reduced bone mineral density, which may be progressive and only partially reversible. For most microprolactinomas, dopamine agonists are the treatment of choice, achieving normoprolactinaemia and restoring gonadal function in 80-90% of cases. Trans-sphenoidal surgery is curative in 60%, but may be complicated by hypopituitarism and is usually reserved for patients with dopamine agonist intolerance or resistance. A subgroup of patients with small tumours, mild symptoms and normal gonadal function may be monitored without specific treatment--the risk of tumour expansion is small. Macroprolactinomas should be treated medically, dopamine agonists controlling prolactin secretion and achieving significant tumour shrinkage in 80% of cases, whereas surgery is curative in only a quarter. Cabergoline is the dopamine agonist of choice in most situations, being better tolerated and more effective than bromocriptine. Quinagolide is an effective alternative. Dopamine agonist withdrawal or dose reduction should be considered after 2-5 years therapy. Oestrogens may be used with caution in women with prolactinomas.

Predicting cardiovascular risk using conventional vs ambulatory blood pressure in older patients with systolic hypertension. Systolic Hypertension in Europe Trial Investigators

CONTEXT

The clinical use of ambulatory blood pressure (BP) monitoring requires further validation in prospective outcome studies.

OBJECTIVE

To compare the prognostic significance of conventional and ambulatory BP measurement in older patients with isolated systolic hypertension.

DESIGN

Substudy to the double-blind placebo-controlled Systolic Hypertension in Europe (Syst-Eur) Trial, started in October 1988 with follow up to February 1999. The conventional BP at randomization was the mean of 6 readings (2 measurements in the sitting position at 3 visits 1 month apart). The baseline ambulatory BP was recorded with a noninvasive intermittent technique.

SETTING

Family practices and outpatient clinics at primary and secondary referral hospitals.

PARTICIPANTS

A total of 808 older (aged > or =60 years) patients whose untreated BP level on conventional measurement at baseline was 160 to 219 mm Hg systolic and less than 95 mm Hg diastolic.

INTERVENTIONS

For the overall study, patients were randomized to nitrendipine (n = 415; 10-40 mg/d) with the possible addition of enalapril (5-20 mg/d) and/or hydrochlorothiazide (12.5-25.0 mg/d) or to matching placebos (n = 393).

MAIN OUTCOME MEASURES

Total and cardiovascular mortality, all cardiovascular end points, fatal and nonfatal stroke, and fatal and nonfatal cardiac end points.

RESULTS

After adjusting for sex, age, previous cardiovascular complications, smoking, and residence in western Europe, a 10-mm Hg higher conventional systolic BP at randomization was not associated with a worse prognosis, whereas in the placebo group, a 10-mm Hg higher 24-hour BP was associated with an increased relative hazard rate (HR) of most outcome measures (eg, HR, 1.23 [95% confidence interval [CI], 1.00-1.50] for total mortality and 1.34 [95% CI, 1.03-1.75] for cardiovascular mortality). In the placebo group, the nighttime systolic BP (12 AM-6 AM) more accurately predicted end points than the daytime level. Cardiovascular risk increased with a higher night-to-day ratio of systolic BP independent of the 24-hour BP (10% increase in night-to-day ratio; HR for all cardiovascular end points, 1.41; 95% CI, 1.03-1.94). At randomization, the cardiovascular risk conferred by a conventional systolic BP of 160 mm Hg was similar to that associated with a 24-hour daytime or nighttime systolic BP of 142 mm Hg (95% CI, 128-156 mm Hg), 145 mm Hg (95% CI, 126-164 mm Hg) or 132 mm Hg (95% CI, 120-145 mm Hg), respectively. In the active treatment group, systolic BP at randomization did not significantly predict cardiovascular risk, regardless of the technique of BP measurement.

CONCLUSIONS

In untreated older patients with isolated systolic hypertension, ambulatory systolic BP was a significant predictor of cardiovascular risk over and above conventional BP.

Impact of obstetric factors on cord blood donation for transplantation

Recent reports have shown that low nucleated cell dose significantly decreases survival after cord blood transplantation. Prior to starting clinical cord blood banking we investigated the impact of obstetric factors on cell dose and volume of cord blood donations. Cord blood was obtained from 114 normal full-term deliveries. Mean volume collected was 93.5 ml, mean total nucleated cell count (TNC) was 13.1 x 108. Statistical analysis was by backwards stepwise regression. Significant factors affecting nucleated cell yield were volume of blood collected (P < 0.001), length of gestation (P < 0. 0001), time from delivery of the infant to cord clamping (P = 0.018) and total length of labour (P = 0.002). In clinical cord blood banking we have successfully used these findings for pre-collection assessment of placentae. Out of 476 cord blood donations subsequently collected for banking, only 29 (6.1%) have been discarded due to low volume. The mean TNC of the 409 banked units following volume reduction was 10.1 x 108. Despite careful optimization of collection, processing and storage techniques, cell dose still limits cord blood transplantation to smaller recipients.

An innovative professional nursing practice model

Nursing, as with health care delivery, is changing to meet the greater challenges brought about by managed care and the accompanying external forces in the marketplace. Nurses, with their vast resources of knowledge and experience, are crucial in achieving optimal quality care. Given the opportunity to redefine and strengthen the impact of nursing practice at Piedmont Medical Center in Atlanta, Georgia, a group of advanced practice nurses began developing a unique practice model. The resulting Professional Nursing Practice Model--a theoretical framework created for nurses by nurses--presents a common vision of human beings, health, and nursing in accordance with the values and beliefs of nursing. This model demonstrates the importance of a person-centered, value-driven nursing practice across the continuum of health from birth to death.

Studies with a growth hormone antagonist and dual-fluorescent confocal microscopy demonstrate that the full-length human growth hormone receptor, but not the truncated isoform, is very rapidly internalized independent of Jak2-Stat5 signaling

We have investigated trafficking of two negative regulators of growth hormone receptor (GHR) signaling: a human, truncated receptor, GHR1-279, and a GH antagonist, B2036. Fluorescent-labeled growth hormone (GH) was rapidly internalized by the full-length GHR, with >80% of the hormone internalized within 5 min of exposure to GH. In contrast, <5% of labeled GH was internalized by cells expressing truncated GHR1-279. Using another truncated receptor, GHR1-317 fused to enhanced green fluorescent protein (EGFP), we have exploited fluorescence energy transfer to monitor the trafficking of ligand-receptor complexes. The data confirmed that internalization of this truncated receptor is very inefficient. It was possible to visualize the truncated GHR1-317-EGFP packaged in the endoplasmic reticulum, its rapid movement in membrane bound vesicles to the Golgi apparatus, and subsequent transport to the cell membrane. The GH antagonist, B2036, blocked Jak2-Stat5-mediated GHR signaling but was internalized with a similar time course to native GH.

THE RESULTS

1) demonstrate the rapid internalization of GH when studied under physiological conditions; 2) confirm the hypothesis that internalization of cytoplasmic domain truncated human GHRs is very inefficient, which explains their dominant negative action; and 3) show that the antagonist action of B2036 is independent of receptor internalization.

Development of evidence-based guidelines in midwifery and gynaecology nursing

OBJECTIVE

To develop an effective and efficient method for basing nursing practice on research evidence.

SETTING

The Royal Women's Hospital, Brisbane, Australia.

METHOD

Nurses and midwives from various clinical areas were invited to participate in an evidence-based practice project. Standard procedures for retrieving relevant articles and evaluating their quality were observed. Where possible, raw data from studies with similar methods were summarised using appropriate statistical tests.

FINDINGS

Several guidelines have been developed, staff involved with the project have become 'research literate' and the project is contributing to the hospital-wide quality improvement activities.

CONCLUSIONS AND IMPLICATIONS FOR PRACTICE

It is possible to translate research findings into practice when small groups use systematic reviews to develop practice guidelines.

Systolic Hypertension in Europe (Syst-Eur) trial phase 2: objectives, protocol, and initial progress. Systolic Hypertension in Europe Investigators

The Systolic Hypertension in Europe (Syst-Eur) trial proved that blood pressure (BP) lowering therapy starting with nitrendipine reduces the risk of cardiovascular complications in older (> or = 60 years) patients with isolated systolic hypertension (systolic BP > or = 160 mm Hg and diastolic BP < 95 mm Hg). After the completion of the Syst-Eur trial on 14 February 1997, 3506 consenting patients (93.0% of those eligible) were enrolled in phase 2 of the Syst-Eur trial. This open follow-up study aims to confirm the safety of long-term antihypertensive therapy based on a dihydropyridine. To lower the sitting systolic BP below 150 mm Hg (target BP), the first-line agent nitrendipine (10-40 mg/day) may be associated with enalapril (5-20 mg/day), hydrochlorothiazide (12.5-25 mg/day), both add-on study drugs, or if required any other antihypertensive agent. On 1 November 1998, 3248 patients were still being followed, 86 patients had proceeded to non-supervised follow-up, and 43 had died. The median follow-up in Syst-Eur 2 was 14.3 months. At the last available visit, systolic/diastolic BP in the patients formerly randomised to placebo (n = 1682) or active treatment (n = 1824), had decreased by 13.2/5.2 mm Hg and by 4.6/1.6 mm Hg, respectively, so that the between-group BP difference was 1.7 mm Hg systolic (95% Ci: 0.8 to 2.6 mm Hg; P < 0.001) and 0.9 mm Hg diastolic (95% Cl: 0.4 to 1.5 mm mm Hg; P < 0.001). At the beginning of Syst-Eur 2, the goal BP was reached by 25.4% and 50.6% of the former placebo and active-treatment groups; at the last visit these proportions were 55.9% and 63.1%, respectively. At that moment, 45.9% of the patients were on monotherapy with nitrendipine, 29.3% took nitrendipine in combination with other study drugs. Until the end of 2001, BP control of the Syst-Eur 2 patients will be further improved. Cardiovascular complications and adverse events, such as cancer or gastro-intestinal bleeding, will be monitored and validated by blinded experts.

Lack of evidence for direct involvement of NMDA receptors or polyamines in blood-brain barrier injury after cerebral ischemia in rats

It is hypothesized that after various types of brain injury, blood-brain barrier (BBB) opening and vasogenic edema result from excessive neuronal release of glutamate and stimulation of capillary N-methyl-d-aspartate (NMDA) receptors linked to polyamine (putrescine) synthesis in endothelial cells. We produced cerebral ischemia in rats and measured BBB opening 6 h later as the increase in regional transfer constants (Ki) for blood to brain diffusion of [3H]sucrose. Such BBB opening was not mitigated by drugs which block NMDA receptors (MK801 or AR-R 15896AR) or polyamine synthesis (difluoromethylornithine). These results question generality of the capillary NMDA receptor/polyamine hypothesis.