Elevated expression of exogenous Rad51 leads to identical increases in gene-targeting frequency in murine embryonic stem (ES) cells with both functional and dysfunctional p53 genes

The Rad51 gene is the mammalian homologue of the bacterial RecA gene and catalyses homologous recombination in mammalian cells. In some cell types Rad51 has been shown to interact with p53, leading to inhibition of Rad51 activity. Here, we show a two- to four-fold increase in gene-targeting frequency at the HPRT locus using murine ES clones preengineered to overexpress Rad51, and a twofold increase in targeting frequency when a Rad51 expression cassette was cointroduced to wild-type ES cells with the targeting construct. In addition to its effect on homologous recombination, we show that Rad51 may down-regulate illegitimate recombination. We investigated the dependence of these phenomena upon p53 and found no evidence that the Rad 51-mediated increase is affected by the functional status of p53, a conclusion supported by the observed cytoplasmic localisation of p53 in ES cells following electroporation. Furthermore, in the absence of additional Rad51, p53-deficient ES cells do not have elevated rates of homologous recombination with extrachromosomal DNA. These findings demonstrate that Rad51 levels modify both homologous and illegitimate recombination, but that these phenomena are independent of p53 status.

Psychosocial distress associated with disfiguring eye conditions

PURPOSE OF STUDY

Visible disfigurement is associated with a range of psychosocial difficulties; however, the problems encountered by patients with eye conditions are under-researched. This study aimed to establish the extent and type of psychosocial distress in this patient population, and to explore the extent to which patients' needs are currently met.

METHOD

Standardised measures (anxiety, depression, appearance-related distress, and quality of life) and a semistructured interview (exploring individual experiences and satisfaction with care) were administered to 153 consecutive attenders at outpatient eye clinics in three different hospitals. Responses were analysed using descriptive statistics, multiple regression, and cluster analyses.

RESULTS

Between 10 and 49% of the patient sample scored unfavourably on standardised measures in comparison with normative values. Cluster analyses revealed that more distressed patients typically exhibited higher levels of anxiety, depression, social anxiety, self-consciousness, and social avoidance. Quality of life scores were also less favourable. Distressed patients felt less well informed, less involved in their treatment, and less well supported in the clinic setting. Variability within the sample was high; however, the effects of the cause and duration of the condition were not significantly related to distress. Clinic staff identified a variety of constraints to meeting patients' need, including patient numbers, the lack of appropriate training, and the lack of referral possibilities.

CONCLUSIONS

A considerable proportion of patients with disfiguring eye conditions experience high levels of psychosocial distress. Several options exist for ways in which patients' needs might more effectively be met within the constraints currently facing care providers.

A prospective study of the prevalence of undiagnosed coeliac disease in laboratory defined iron and folate deficiency

AIMS

To determine the prevalence of coeliac disease in a group of patients in the community who have been shown in the laboratory to have iron and/or folate deficiency. To assess the cost efficiency of this laboratory based case finding strategy.

METHODS

The study was undertaken in a large general hospital in the UK serving a population of 300 000. Three hundred and thirty three eligible patients with iron and/or folate deficiency were identified and contacted over an 18 month period. Case finding was by testing for coeliac disease using serological methods and subsequent histological confirmation.

RESULTS

Of the 333 eligible and contactable patients with iron and/or folate deficiency, 258 (77%) consented to coeliac disease antibody testing. Twenty eight patients (10.9%) were positive for coeliac disease antibodies. Of these, 24 patients proceeded to endoscopy and biopsy, resulting in 12 cases of histologically confirmed coeliac disease (4.7% (95% confidence interval, 2.1% to 6.8%) of patients tested for coeliac disease antibodies).

CONCLUSIONS

This laboratory based methodology detected a considerable number of new coeliac disease cases in the community. Many of these patients did not present with clinical findings suggestive of malabsorption and might not otherwise have been diagnosed. Laboratory based methodologies should be considered in conjunction with other strategies for the early identification and treatment of coeliac disease.

Development and preliminary evaluation of a clinical guidance programme for the decision about prophylactic oophorectomy in women undergoing a hysterectomy

OBJECTIVES

To develop a decision analysis based and computerised clinical guidance programme (CGP) that provides patient specific guidance on the decision whether or not to undergo a prophylactic oophorectomy to reduce the risk of subsequent ovarian cancer and to undertake a preliminary pilot and evaluation.

SUBJECTS

Women who had already agreed to have a hysterectomy who otherwise had no ovarian pathology.

SETTING

Oophorectomy decision consultation at the outpatient or pre-admission clinic.

METHODS

A CGP was developed with advice from gynaecologists and patient groups, incorporating a set of Markov models within a decision analytical framework to evaluate the benefits of undergoing a prophylactic oophorectomy or not on the basis of quality adjusted life expectancy, life expectancy, and for varying durations of hormone replacement therapy. Sensitivity analysis and preliminary testing of the CGP were undertaken to compare its overall performance with established guidelines and practice. A small convenience sample of women invited to use the CGP were interviewed, the interviews were taped and transcribed, and a thematic analysis was undertaken.

RESULTS

The run time of the programme was 20 minutes, depending on the use of opt outs to default values. The CGP functioned well in preliminary testing. Women were able to use the programme and expressed overall satisfaction with it. Some had reservations about the computerised formal and some were surprised at the specificity of the guidance given.

CONCLUSIONS

A CGP can be developed for a complex healthcare decision. It can give evidence-based health guidance which can be adjusted to account for individual risk factors and reflects a patient's own values and preferences concerning health outcomes. Future decision aids and support systems need to be developed and evaluated in a way which takes account of the variation in patients' preferences for inclusion in the decision making process.

How to do safe sternal reentry and the risk factors of redo cardiac surgery: a 21-year review with zero major cardiac injury

OBJECTIVES

Resternotomy is a common part of cardiac surgical practice. Associated with resternotomy are the risks of cardiac injury and catastrophic hemorrhage and the subsequent elevated morbidity and mortality in the operating room or during the postoperative period. The technique of direct vision resternotomy is safe and has fewer, if any, serious cardiac injuries. The technique, the reduced need for groin cannulation and the overall low operative mortality and morbidity are the focus of this restrospective analysis.

METHODS

The records of 495 patients undergoing 546 resternotomies over a 21-year period to January 2000 were reviewed. All consecutive reoperations by the one surgeon comprised patients over the age of 20 at first resternotomy: M:F 343:203, mean age 57 years (range 20 to 85, median age 60). The mean NYHA grade was 2.3 [with 67 patients (I), 273 (II), 159 (III), 43 (IV), and 4 (V classification)] with elective reoperation in 94.6%. Cardiac injury was graded into five groups and the incidence and reasons for groin cannulation estimated. The morbidity and mortality as a result of the reoperation and resternotomy were assessed.

RESULTS

The hospital/30 day mortality was 2.9% (95% CI: 1.6%-4.4%) (16 deaths) over the 21 years. First (481), second (53), and third (12) resternotomies produced 307 uncomplicated technical reopenings, 203 slower but uncomplicated procedures, 9 minor superficial cardiac lacerations, and no moderate or severe cardiac injuries. Direct vision resternotomy is crystalized into the principle that only adhesions that are visualized from below are divided and only sternal bone that is freed of adhesions is sewn. Groin exposure was never performed prophylactically for resternotomy. Fourteen patients (2.6%) had such cannulation for aortic dissection/aneurysm (9 patients), excessive sternal adherence of cardiac structures (3 patients), presurgery cardiac arrest (1 patient), and high aortic cannulation desired and not possible (1 patient). The average postop blood loss was 594 mL (95% CI:558-631) in the first 12 hours. The need to return to the operating room for control of excessive bleeding was 2% (11 patients). Blood transfusion was given in 65% of the resternotomy procedures over the 21 years (mean 854 mL: 95% CI 765-945 mL) and 41% over the last 5 years.

CONCLUSIONS

The technique of direct vision resternotomy has been associated with zero moderate or major cardiac injury/catastrophic hemorrhage at reoperation. Few patients have required groin cannulation. In the postoperative period, there was acceptable blood loss, transfusion rates, reduced morbidity, and moderate low mortality for this potentially high risk group.

Experiences with redo aortic valve surgery

OBJECTIVES AND METHODS

Reoperations are an integral part of a cardiac surgeon's practice. We share our experience of 546 reoperations over the last 21 years to January 2000, with the focus directed towards the timing of reoperation, reducing the mortality and morbidity of reoperation and rereplacement aortic valve surgery, and understanding the important risk factors. In addition, the precise technical steps that facilitate careful successful explantation of various devices (allograft, stented and stentless xenografts, and mechanical valves) are detailed.

RESULTS

Optimal planned reoperation before deterioration to New York Heart Association Class III/IV levels and before unfavorable cardiac and comorbidity general system failure occurs has produced low mortality and morbidity as compared with first operation results. However, unfavorable delays and late rereferral result in mortality rates of up to 22% for emergency redo AVR for degenerated bioprostheses.

CONCLUSION

Cardiac surgical units have the opportunity to establish a closer patient-surgeon relationship, which favors, when necessary, the optimal timing of reoperation. Knowledge of the more important risk factors and adherence to specific technical steps at explantation of various devices enhances satisfactory reoperation outcomes.

Pyroclastic flows and surges generated by the 25 June 1997 dome collapse, Soufrière Hills Volcano, Montserrat

On 25 June 1997, an unsteady, retrogressive, partial collapse of the lava dome at Soufrière Hills Volcano lasted 25 minutes and generated a major pulsatory block-and-ash flow, associated pyroclastic surges and a surge-derived pyroclastic flow that inundated an area of 4 km2 on the north and NE flanks of the volcano. Three main pulses are estimated to have involved 0.78, 2.36 and 2.36 x 106m3 of debris and the average velocities of the fronts of the related block-and-ash flow pulses were calculated to be 15 ms-1, 16.1 ms-1 and 21.9 ms-1 respectively.

Deposits of block-and-ash flow pulses 1 and 2 partially filled the main drainage channel so that material of the third pulse spilled out of the channel at several places, inundating villages on the eastern coastal plain. Bends and constrictions in the main drainage channel, together with depositional filling of the channel, assisted detachment of pyroclastic surges from the pulsatory block-and-ash flow. The most extensive pyroclastic surge detached at an early stage from the third block-and-ash flow pulse, swept down the north flank of the volcano and then climbed 70 m in elevation before dissipating. Rapid sedimentation from this surge generated a high-concentration granular flow (surge-derived pyroclastic flow) that drained westwards into a valley not anticipated to be at high risk.

Observations support the hypothesis that the interior of the Soufrière Hills Volcano lava dome was pressurized and that pyroclastic surge development became more substantial as deeper, more highly pressurized parts of the dome were incorporated into the pyroclastic flow. Surge development was at times so violent that expanded clouds detached from the block-and-ash flow within a few tens of metres of the lava dome.

Economic impact of lupus

Current cost analyses that have been conducted on systemic lupus erythematosus (SLE) have not been thorough economic evaluations of the disease and treatment; they have not considered the broad treatment effects such as quality of life and productivity. They have however examined healthcare resource use (ie, direct costs) and time loss (ie, indirect costs) and at minimum provide some perspective on the societal impact of this disease. Incorporating all of the above factors into an analysis is extremely important in SLE and it is hoped that future analyses will include them. Also, any new economic analyses that are conducted will need to compare the cost of new or alternative SLE therapies with existing standard treatments because new treatments are on the horizon.

Influence of alpha-helices on the emulsifying properties of proteins

A peptide derived from apomyoglobin by cyanogen bromide cleavage was found to be an active emulsifier. This molecule, peptide 1-55, has two potential amphipathic alpha-helices and a hydrophilic C-terminal domain. The importance of each of these domains to the emulsifying properties of this molecule was investigated by testing the products of gene constructs based on the sequence of peptide 1-55, but lacking one of the three domains. The emulsifying activity of the peptides lacking either of the alpha-helices was correlated with the hydrophobic moments of their respective helices. The hydrophobic moment is a measure of the amphipathicity of alpha-helices; a hydrophobic moment analysis of other emulsifying peptides supports the hypothesis that a high hydrophobic moment contributes to good emulsifying properties in a molecule which contains alpha-helices.

The influence of formulation variables on the properties of pellets containing a self-emulsifying mixture

A method of converting self-emulsifying drug delivery systems to a pellet form has been studied. Formulations with varied relative quantities of an oil/surfactant mixture, water, microcrystalline cellulose (MCC), and lactose were chosen in a statistical design after preliminary ranging experiments. Pellets were produced by extrusion/spheronization. The characteristics of the pellets were studied by sieving, disintegration testing, diametral compression, image analysis, non-contact laser profilometry, and scanning electron microscopy. The effects of the formulation variables on pellet properties were evaluated by analysis of variance. It was possible to relate the formulation variables to all the quantified pellet properties except the shape. The relative quantities of oil/surfactant and water had an effect on the amount of liquid and oil/surfactant that could be incorporated into the powder, extrusion force, median diameter, size spread, disintegration time, tensile strength, and surface roughness. The relative quantities of lactose and MCC had an effect on the amount of liquid and oil/surfactant that could be incorporated into the powder, tensile strength, and roughness only. Water was an essential element of the formulations. The maximum quantity of the specific oil/surfactant combination studied that can be incorporated was 42% of the dry pellet weight.

Hirschsprung disease, mental retardation and dysmorphic facial features in five unrelated children

We report five patients with Hirschsprung disease, severe mental retardation and dysmorphic facial features including hypertelorism, prominent forehead and dysmorphic ears. All four boys had hypospadias. All had postnatally retarded growth. One of them had a de novo apparently balanced translocation 46,XY,t(2;11)(q22.2;q21). There are several reports on patients with Hirschsprung disease, mental retardation and various dysmorphic features. Some of them, especially those reported by Tanaka et al. [(1993) Pediatr Neurol 9:479-481], Lurie et al. [(1994) Genet Couns 5:11-14] and Mowat et al. [(1998) J Med Genet 35:617-623] closely resemble our patients suggesting that they have the same malformation syndrome.

Guidelines for reporting clinical features in cases with MECP2 mutations

An international group recommends that papers relating phenotypes to genotypes involving mutations in the X chromosome gene MECP2 should provide a minimum data set reporting the range of disturbances frequently encountered in Rett Syndrome. A simple scoring system is suggested which will facilitate comparison among the various clinical profiles. Features are described which should prompt screening for MECP2 mutations.

Length of stay. How short should hospital care be?

BACKGROUND

Reducing length of hospital stay (LOS) is a policy aim for many health care systems and is thought to indicate efficiency.

METHODS

A MedLine search was undertaken for articles relating to 'LOS', 'early discharge' or 'patient discharge' between 1983 and 1997 and a selective search was undertaken for material published before 1983.

RESULTS

Routine data showed that there were variations in LOS between countries, regions and hospitals. The trends in LOS showed a decrease over time in all regions. Research consistently fails to show an adverse effect on health outcomes of reducing LOS, but there may nevertheless be an ethical or moral minimum LOS. Two recent examples illustrate this. There has been an outcry at some ultrashort stays, for example 'drive-through mastectomy' and 'lunchtime abortion' and these are discussed in the review.

CONCLUSIONS

There are a number of reasons for the perceived lack of relationship between LOS and health outcomes. Clearly reducing days of care at the low-intensity end of a hospital stay may not necessarily affect health outcomes. There is a case to be made for tailoring care more exactly to an individual's needs by looking at the actual components of care rather than the place of care--within or outside hospital walls.