The mechano-biology of the epiphysis of the long bones as revealed by photoelastic models

Stress contours have been generated in photoelastic models simulating cartilaginous and bony epiphyses. According to the findings, the secondary centre of ossification is formed in areas of the cartilaginous epiphysis shown to have reduced mechanical stress. The bony epiphysis appears to have been developed as a more mechanically efficient structure.

Clinical findings of a myoclonus-dystonia family with two distinct mutations

Myoclonus-dystonia has recently been associated with mutations in the epsilon-sarcoglycan gene (SCGE) on 7q21. Previously, the authors reported a patient with myoclonus-dystonia and an 18-bp deletion in the DYT1 gene on 9q34. The authors have now re-evaluated the patient harboring this deletion for mutations in the SGCE gene and identified a missense change. In the current study, the authors describe the clinical details of this family carrying mutations in two different dystonia genes. Further analysis of these mutations separately and together in cell culture and in animal models should clarify their functional consequences.

An economic analysis of specialist heart failure nurse management in the UK; can we afford not to implement it?

AIMS

Hospital activity represents the major component of health care expenditure related to heart failure. This study evaluated the economic impact of applying specialist nurse management programmes that limit heart failure-related hospital readmissions within a whole population.

METHODS

Using a reliable and validated estimate of the current level and cost of heart failure-related hospital activity in the U.K., we determined the thresholds at which the actual cost of establishing and applying a national service based on three different models of specialist nurse management would be equal to the 'cost' of bed utilization associated with preventable hospital readmissions in the year 2000. The three models of care examined were home-based, clinic-based or a combination of home plus clinic-based, post-discharge follow-up. The potential impact of this service was based on a U.K.-wide caseload of 122,000 patients discharged to home with a discharge diagnosis of congestive heart failure in that year.

RESULTS

Based on heart failure-specific patterns of hospital activity, we estimate that 47,000 of these 122,000 patients would normally accumulate a total of 594000 days of associated hospital stay from 49,000 readmissions (for any reason) within 1 year of hospital discharge. The cost of these admissions to the National Health Service was calculated at 166.2 million pounds sterling. Taking into account other costs associated with such hospital activity (e.g. general practice and hospital outpatient visits) each 10% reduction in recurrent bed utilization would be associated with 18.0 million ponds sterling in cost savings. Alternatively, the cost of applying a U.K.-wide programme of home-, clinic- or home plus clinic-based follow-up was calculated to be 69.4 pounds sterling, 73.1 pounds sterling and 72.5 million pounds sterling per annum, respectively. The relative thresholds at which generated 'cost-savings' would equal the cost of applying these programmes of care would therefore be a 38.5%, 40.6% and 40.3% reduction in recurrent bed utilization, respectively. If, as expected, a home-based programme of specialist nurse management reduced recurrent bed utilization by 50% or more, annual savings equivalent to 169,000 pounds sterling per 1000 patients treated would be generated.

CONCLUSIONS

This is the first study to examine the economic consequences of applying a specialist nurse-mediated, post-discharge management service for heart failure within a whole population. Our findings suggest that such a service will not only improve quality of life and reduce readmissions in patients with congestive heart failure, but also reduce costs and improve the efficiency of the health care system in doing so.

An audit of activity and outcome from a daily and a weekly "one stop" rapid assessment chest pain clinic

OBJECTIVES

The recent National Service Framework for coronary heart disease advocates the establishment of rapid assessment clinics for chest pain. But how should these clinics be organised and do they fulfil their objectives? The aim of this study was to compare referral patterns to a daily and a weekly "one stop" rapid access chest pain clinic (RACPC), and to examine clinical outcome in patients attending these clinics.

DESIGN

Patients were prospectively categorised into one of the following subgroups: "acute coronary syndrome", "stable coronary heart disease", or "low risk/non-coronary chest pain". Fatal and non-fatal outcomes were audited over eight months.

SETTING

Both RACPCs were situated within the cardiology departments of two large Glasgow teaching hospitals. Patients were seen by a cardiologist, and underwent non-invasive testing.

PARTICIPANTS

A total of 633 patients with chest pain who were referred by their general practitioner; 500 came to the daily and 133 to the weekly clinic. Forty four (7%) were categorised as having an acute coronary syndrome, 267 (42%) as stable coronary artery disease, and 322 (51%) as low risk/non-coronary chest pain.

RESULTS

Referral patterns to the two clinics differed significantly. Compared with the weekly clinic, more patients with an acute coronary syndrome (7.8 v. 3.8%) and low risk/non-coronary chest pain (55.2 v. 35.6%), but fewer patients with stable coronary disease (37.0 v. 61.6%) were referred to the daily clinic (p<0.00001). During follow up eight (1.3%) patients died from a cardiac cause, and eight (1.3%) patients suffered a myocardial infarction. None of these patients were classified as low risk/non-coronary chest pain.

CONCLUSIONS

(1) RACPCs do provide an effective tool for the early assessment of patients with possible angina. (2) The frequency with which clinics are scheduled may be an important factor in determining how the service is utilised in practice.

Scc1/Rad21/Mcd1 is required for sister chromatid cohesion and kinetochore function in vertebrate cells

Proteolytic cleavage of the cohesin subunit Scc1 is a consistent feature of anaphase onset, although temporal differences exist between eukaryotes in cohesin loss from chromosome arms, as distinct from centromeres. We describe the effects of genetic deletion of Scc1 in chicken DT40 cells. Scc1 loss caused premature sister chromatid separation but did not disrupt chromosome condensation. Scc1 mutants showed defective repair of spontaneous and induced DNA damage. Scc1-deficient cells frequently failed to complete metaphase chromosome alignment and showed chromosome segregation defects, suggesting aberrant kinetochore function. Notably, the chromosome passenger INCENP did not localize normally to centromeres, while the constitutive kinetochore proteins CENP-C and CENP-H behaved normally. These results suggest a role for Scc1 in mitotic regulation, along with cohesion.

Genetic analysis of the DNA-dependent protein kinase reveals an inhibitory role of Ku in late S-G2 phase DNA double-strand break repair

Two major complementary double-strand break (DSB) repair pathways exist in vertebrates, homologous recombination (HR), which involves Rad54, and non-homologous end-joining, which requires the DNA-dependent protein kinase (DNA-PK). DNA-PK comprises a catalytic subunit (DNA-PKcs) and a DNA-binding Ku70 and Ku80 heterodimer. To define the activities of individual DNA-PK components in DSB repair, we targeted the DNA-PKcs gene in chicken DT40 cells. DNA-PKcs deficiency caused a DSB repair defect that was, unexpectedly, suppressed by KU70 disruption. We have shown previously that genetic ablation of Ku70 confers RAD54-dependent radioresistance on S-G(2) phase cells, when sister chromatids are available for HR repair. To test whether direct interference by Ku70 with HR might explain the Ku70(-/-)/DNA-PKcs(-/-/-) radioresistance, we monitored HR activities directly in Ku- and DNA-PKcs-deficient cells. The frequency of intrachromosomal HR induced by the I-SceI restriction enzyme was increased in the absence of Ku but not of DNA-PKcs. Significantly, abrogation of HR activity by targeting RAD54 in Ku70(-/-) or DNA-PKcs(-/-/-) cells caused extreme radiosensitivity, suggesting that the relative radioresistance seen with loss of Ku70 was because of HR-dependent repair pathways. Our findings suggest that Ku can interfere with HR-mediated DSB repair, perhaps competing with HR for DSB recognition.

Proposed preliminary core set measures for disease outcome assessment in adult and juvenile idiopathic inflammatory myopathies

In order to develop a preliminary core set of disease outcome measures for use in clinical trials of idiopathic inflammatory myopathies (IIM), we evaluated those measures used in previous trials, assessed the validation of published instruments and discussed these at an international consensus conference. The initial proposals were further refined by a multidisciplinary group of adult and paediatric specialists experienced in IIM using the Delphi method. The proposed preliminary core set of disease activity measures consists of five domains: physician and patient/parent global assessments of disease activity; muscle strength; physical function; serum activity of muscle enzymes; and an assessment tool to capture extra-skeletal muscle disease activity. The group recommended further development of a core set of disease damage measures for assessment of persistent changes in anatomy, pathology and function of at least 6 months' duration. The group recommended that patient-reported outcomes should include generic health-related quality of life assessments using the Medical Outcomes Study 36-item Short Form (SF-36) health survey in adult IIM patients and a validated quality of life instrument for paediatric patients. We propose the core set of outcome measures as a minimum group of assessments to include in all IIM therapeutic studies. The use of this core set should assist in standardizing outcome measurement and in optimizing therapeutic trials in myositis.

Women report being more likely than men to model their relationships after what they have seen on TV

Students (21 men and 50 women) anonymously answered questions about imitating relationships seen on TV. The women were more likely than men to report trying to model family life after what they saw on TV situational comedies and to expect their significant other to act as those seen on TV. They also more frequently reported experiencing a significant other acting as those on TV. There was no difference by sex in current age, parents' marital status during the students' formative years, or age of separation, divorce, or widowing if any occurred. For neither women nor men did a broken home during the formative years correlate with looking to TV for information on relationships.

Highly differentiated keratinizing squamous cell cancer of the cervix: a rare, locally aggressive tumor not associated with human papillomavirus or squamous intraepithelial lesions

The purpose of this study is to report an unusual variant of cervical squamous cell carcinoma, not associated with either human papillomavirus infection or antecedent squamous intraepithelial lesions. Five women had a diagnosis of invasive cervical cancer discovered at hysterectomy performed for prolapse (two cases), leiomyoma (one case), or a vaginal fistula (two cases). The women ranged in age from 47 to 78 years (mean 59 years). Four of the five had a history of normal Papanicolaou (Pap) smears; the other had a Pap smear diagnosis of atypical squamous cells of undetermined significance (ASCUS). All had large cervical tumors (two with parametrial involvement and one with vaginal involvement) that showed extensive keratin formation, an inverted pattern of growth, and, except for one case, minimal cytologic atypia. There was extensive hyperkeratosis and parakeratosis adjacent to each tumor; none had evidence of squamous intraepithelial lesion. Human papillomavirus testing by polymerase chain reaction in situ hybridization and reverse-transcribed polymerase chain reaction in situ was negative in each case, compared with a detection rate of 107 of 108 (99%) for squamous intraepithelial lesion-associated cervical squamous cell and adenocarcinomas. Two of the women died of extensive local recurrence; two other women were recently diagnosed. We conclude that highly differentiated keratinizing squamous cell carcinoma of the cervix is a rare entity not associated with human papillomavirus infection or squamous intraepithelial lesion and thus difficult to detect on routine cervical cancer screening.

In situ determination of B-cell heavy chain and kappa/lambda light chain expression patterns: methodology and clinical utility

The authors describe a reverse transcriptase in situ polymerase chain reaction (RT in situ PCR) method that allows the determination of B-cell clonality as defined by expression of kappa and lambda mRNA as well as the different VH families that comprise the entire heavy chain (IgH) sequence using paraffin-embedded, formalin-fixed tissue. Polyclonal expression of B-cell light and heavy chains was documented in two reactive lymph nodes and a spleen in the same histologic distribution as the B-cell marker CD20. Monoclonal expression of kappa versus lambda mRNA was documented in 11 cases of B-cell lymphoma and was corroborated in 5 cases by flow cytometry; each case showed monoclonal expression of IgH. The authors analyzed seven additional tissues where a definitive diagnosis of B-cell lymphoma could not be rendered based on histologic, immunohistologic. and clinical analysis. RT in situ PCR for IgH and kappa versus lambda expression differentiated the B-cell lymphomas (n = 2) from reactive B-cell processes (n = 3) and from two cases of B-cell-rich T-cell lymphoma. The described RT in situ PCR methodology allows routine determination of the monoclonal versus multiclonal expression patterns of B cells, which will facilitate the diagnosis of B-cell lymphomas and aid in understanding the pathogenesis of B-cell malignancies using archival, paraffin-embedded tissues.

Nurse led shared care for patients on the waiting list for coronary artery bypass surgery: a randomised controlled trial

OBJECTIVE

To evaluate the effectiveness of a nurse led shared care programme to improve coronary heart disease risk factor levels and general health status and to reduce anxiety and depression in patients awaiting coronary artery bypass grafting (CABG).

DESIGN

Randomised controlled trial.

SETTING

Community, January 1997 to March 1998.

STUDY GROUPS

98 (75 male) consecutive patients were recruited to the study within one month of joining the waiting list for elective CABG at Glasgow Royal Infirmary University NHS Trust. Patients were randomly assigned to usual care (control; n = 49) or a nurse led intervention programme (n = 49).

INTERVENTION

A shared care programme consisting of health education and motivational interviews, according to individual need, was carried out monthly. Care was provided in the patients' own homes by the community based cardiac liaison nurse alternating with the general practice nurse at the practice clinic.

OUTCOME MEASURES

Smoking status, obesity, physical activity, anxiety and depression, general health status, and proportion of patients exceeding target values for blood pressure, plasma cholesterol, and alcohol intake.

RESULTS

Compared with patients who received usual care, those participating in the nurse led programme were more likely to stop smoking (25% v 2%, p = 0.001) and to reduce obesity (body mass index > 30 kg/m(2)) (16.3% v 8.1%, p = 0.01). Target systolic blood pressure improved by 19.8% compared with a 10.7% decrease in the control group (p = 0.001) and target diastolic blood pressure improved by 21.5% compared with 10.2% in the control group (p = 0.000). However, there was no significant difference between groups in the proportion of patients with cholesterol concentrations exceeding target values. There was a significant improvement in general health status scores across all eight domains of the 36 item short form health survey with changes in difference in mean scores between the groups ranging from 8.1 (p = 0.005) to 36.1 (p < 0.000). Levels of anxiety and depression improved (p < 0.000) and there was improvement in time spent being physically active (p < 0.000).

CONCLUSIONS

This nurse led shared care intervention was shown to be effective for improving care for patients on the waiting list for CABG.

Characterization of polymorphic structure of cathepsin G gene: role in cardiovascular and cerebrovascular diseases

Cathepsin G (CTSG), a serine protease released from activated neutrophils, may cause platelet activation, leading to intravascular thrombosis, thus contributing to cardiovascular and cerebrovascular disease. Applying the candidate gene approach, we screened the 5'-flanking region and the entire coding region of the CTSG gene for genetic variation by using polymerase chain reaction/single-strand conformation polymorphism analysis from 96 patients at high risk for myocardial infarction (MI). We identified 4 polymorphisms in the 5'-flanking region (G-618C, G-315A, C-179T, and C-160T) and 1 polymorphism in the coding region (Asn125Ser) of the gene and genotyped the participants in the Etude Cas-Temoins sur l'Infarctus du Myocarde (ECTIM Study), a case-control study for MI, and in the Etude du Profil Génétique de l'Infarctus Cérébral (GENIC Study), a case-control study for brain infarction (BI), for all identified genetic variants. The potential in vitro functionality of the 4 variants in the 5'-flanking region was investigated with transient transfection analyses in U937 cells with different allelic promoter constructs by using a luciferase assay. Our in vitro analyses did not reveal any differences for the investigated allelic constructs with respect to promoter activity, and none of the polymorphisms in the 5'-flanking region was associated with the available phenotypes in either study. Allele and genotype distributions of all identified polymorphisms did not globally differ between cases and controls in the ECTIM Study. However, in patients from the ECTIM Study, the Ser125 allele was significantly associated with elevated plasma fibrinogen levels (P=0.006), but this effect was not seen in controls (case-control heterogeneity, P=0.04). There was a significant interaction between CTSG Asn125Ser and the beta-fibrinogen gene polymorphism G-455A on plasma fibrinogen levels (P=0.04). In the GENIC Study, the odds ratio for BI associated with CTSG Ser125 carrying was 1.82 (95% CI 1.16 to 2.84, P=0.008) in patients without a history of cardiovascular or cerebrovascular diseases. Our results indicate that the CTSG Ser125 allele is associated with plasma fibrinogen levels in MI patients from the ECTIM Study and with BI in the GENIC Study. Further studies should be carried out to define the underlying mechanisms.

Homologous DNA recombination in vertebrate cells

The RAD52 epistasis group genes are involved in homologous DNA recombination, and their primary structures are conserved from yeast to humans. Although biochemical studies have suggested that the fundamental mechanism of homologous DNA recombination is conserved from yeast to mammals, recent studies of vertebrate cells deficient in genes of the RAD52 epistasis group reveal that the role of each protein is not necessarily the same as that of the corresponding yeast gene product. This review addresses the roles and mechanisms of homologous recombination-mediated repair with a special emphasis on differences between yeast and vertebrate cells.

Platelet-activating factor antagonism and streptokinase-induced hypotension in clinical acute myocardial infarction

Continuing efforts are being made to improve thrombolytic therapy for acute myocardial infarction (AMI). The rate of streptokinase (SK) infusion is commonly limited by the hypotension that is induced. If this could be avoided, an accelerated regimen of SK could be given, analagous to that used for other thrombolytic agents such as alteplase. The mechanism of the SK-induced hypotension is unknown, but there is some evidence that platelet-activating factor (PAF) plays a role. The potent PAF receptor antagonist lexipafant (10 mg) (n=35), or matching placebo (n=36), was administered intravenously over 5 min, in a randomized double-blinded protocol, to consecutive patients about to receive SK for AMI; all but three had inferior MI, because of the preference for strategies other than SK therapy in patients with anterior MI. The rate of infusion of SK was set to give 1.5x10(6) units over 30 min, anticipating significant hypotension. Blood pressure fell sharply over the first 10 min of SK administration. The maximum fall in systolic blood pressure occurred between 8 and 12 min, and averaged 43+/-28 mmHg (mean+/-S.D.) and 40+/-26 mmHg in patients given placebo and lexipafant respectively. Systolic pressure having fallen to <90 mmHg, according to protocol the SK administration rate was reduced in 21 of 36 (58%) of patients given placebo and in 19 of 35 (54%) of patients given lexipafant. The total SK dose was given to all subjects over 40.3+/-17.5 and 40.2+/-13.4 min for the placebo and lexipafant groups respectively. Peak and time integrals of creatine kinase were not different in the two groups. There were no adverse effects attributable to lexipafant. It is concluded that the PAF receptor antagonist lexipafant has no significant effect on SK-induced hypotension and does not facilitate an accelerated regimen of administration.

Association studies between haemochromatosis gene mutations and the risk of cardiovascular diseases

BACKGROUND

Haemochromatosis is a common genetic disorder, inherited as an autosomal recessive trait that results in a progressive accumulation of iron in most tissues of the body. Positive association studies have been recently published between cardiovascular diseases and heterozygosity for the major mutation C282Y in the haemochromatosis gene HFE.

METHODS

In the present work, we have determined the HFE genotypes for C282Y and H63D in subjects from two case-control studies: the ECTIM and GENIC studies, designed to identify genetic variants associated with myocardial and brain infarction, respectively. In addition, we tested whether HFE mutations were associated with the degree of arteriosclerosis assessed non-invasively by Doppler ultrasonography on the carotid and femoral arteries, in a group of apparently healthy individuals (the AXA Study).

RESULTS

The prevalence of 282Y, and 63D allele carriers, did not differ between cases and controls in the ECTIM and in the GENIC studies, while 63D but not 282Y carriers were more numerous among subjects with atherosclerotic plaques in the AXA Study.

CONCLUSIONS

These three studies do not provide consistent evidence supporting the hypothesis that HFE mutations are associated with an increased risk of cardiovascular disease and with the development of arteriosclerosis.