Opposing roles of gp130-mediated STAT-3 and ERK-1/ 2 signaling in liver progenitor cell migration and proliferation

Gp130-mediated IL-6 signaling may play a role in oval cell proliferation in vivo. Levels of IL-6 are elevated in livers of mice treated with a choline-deficient ethionine-supplemented (CDE) diet that induces oval cells, and there is a reduction of oval cells in IL-6 knockout mice. The CDE diet recapitulates characteristics of chronic liver injury in humans. In this study, we determined the impact of IL-6 signaling on oval cell-mediated liver regeneration in vivo. Signaling pathways downstream of gp130 activation were also dissected. Numbers of A6(+ve) liver progenitor oval cells (LPCs) in CDE-treated murine liver were detected by immunohistochemistry and quantified. Levels of oval cell migration and proliferation were compared in CDE-treated mouse strains that depict models of gp130-mediated hyperactive ERK-1/2 signaling (gp130(deltaSTAT)), hyperactive STAT-3 signaling (gp130(Y757F) and Socs-3(-/deltaAlb)) or active ERK-1/2 as well as active STAT-3 signaling (wild-type). The A6(+ve) LPC numbers were increased with IL-6 treatment in vivo. The gp130(Y757F) mice displayed increased A6(+ve) LPCs numbers compared with wild-type and gp130(deltaSTAT) mice. Numbers of A6(+ve) LPCs were also increased in the livers of CDE treated Socs-3(-/deltaAlb) mice compared with their control counterparts. Lastly, inhibition of ERK-1/2 activation in cultured oval cells increased hyper IL-6-induced cell growth. For the first time, we have dissected the gp130-mediated signaling pathways, which influence liver progenitor oval cell proliferation.

CONCLUSION

Hyperactive STAT-3 signaling results in enhanced oval cell numbers, whereas ERK-1/2 activation suppresses oval cell proliferation.

Engaging women from South Asian communities in cardiac rehabilitation

This study sought to describe experiences and perceptions of cardiac rehabilitation among a sample of women from South Asian communities. Data were collected via eight semi-structured interviews with staff and a focus group discussion with nine clients from a community-based, culturally sensitive cardiac rehabilitation service. A number of individual, cultural and practical barriers to participation were identified. Facilitators centred on whether the format and content of the sessions could be considered "appropriate". For example, a women's dance group proved to be successful through the selection of a familiar local venue, supportive session leader, and activity that was felt to be both enjoyable and beneficial. This study has shown that it is possible to engage hard-to-reach groups in cardiac rehabilitation and physical activity. Further work is needed to explore whether this research is applicable in other ethnic groups and whether the lessons learned could be successfully incorporated into mainstream health services.

Optimisation of systems to locate discrete gamma-ray sources within a large search area

Most systems used to locate discrete gamma-ray sources involve systematically passing a detector over the search area while seeking a significant increase in the observed count-rate. This paper discusses the ways in which such systems may be designed to maximise the probability of locating a source. It is shown that optimised systems use a collimated, energy-discriminating detector and overlapping counting intervals determined by the scanning geometry and speed.

Telomerase reverse transcriptase (TERT) expression and proliferation in canine brain tumours

Telomerase is a ribonucleoprotein enzyme complex that synthesizes telomere DNA. It is detected in 85-90% of malignant tumours in humans, but not in most somatic cells. Because telomerase plays a critical role in cell immortality, it represents an important target for anticancer therapies. We have previously shown that the dog is a potentially useful model for evaluating telomerase-based therapeutics. In this present study we analysed 93 canine brain tumours for telomerase reverse transcriptase (TERT) expression by immunohistochemistry. TERT immunoreactivity was detected in 16 of 50 grade 1 (32%) and 29 of 43 grade 2 tumours (67.4%), demonstrating a statistically significant association with histological grade (P = 0.00012). A subset of 51 tumours was also assessed for MIB-1 expression. The MIB-1 labelling index (LI) was found to correlate significantly with tumour grade, with a mean MIB-1 LI of 1.5% for grade 1 tumours, as compared with a mean MIB-1 LI of 21.7% for grade 2 tumours (P << 0.001). The MIB-1 LI was also significantly associated with TERT expression in all brain tumours (P << 0.001). These data further support the dog as a model for the preclinical development of telomerase-based therapeutics in brain tumours.

Measurement of forces inside a three-dimensional pile of frictionless droplets

We present systematic and detailed measurements of interparticle contact forces inside three-dimensional piles of frictionless liquid droplets. We measured long-range chainlike correlations of the directions and magnitudes of large forces, thereby establishing the presence of force chains in three dimensions. Our correlation definition provides a chain persistence length of 10 mean droplet diameters, decreasing as load is applied to the pile. We also measured the angles between contacts and showed that the chainlike arrangement arises from the balance of forces. Moreover, we found that piles whose height was comparable to the chain persistence length exhibited substantially greater strain hardening than did tall piles, which we attributed to the force chains. Together, the results establish a connection between the microscopic force network and the elastic response of meso- or macroscopic granular piles. The conclusions drawn here should be relevant in jammed systems generally, including concentrated emulsions and piles of sand or other heavy particles.

The involvement of the plasma membrane in the development of Dictyostelium discoideum. I. Purification of the plasma membrane

A method for the isolation and purification of plasma membranes of Dictyostelium discoideum by equilibrium centrifugation on sucrose followed by Renografin continuous density gradients has been developed and monitored both with electron microscopy and a number of enzyme assays. On electron microscopy, the final plasma membrane fractions are judged to be freethe basis of of nuclei, rough endoplasmic reticulum, lysosomes and peroxisomes. Some profiles of the mitochondrial inner membranes are found within the plasma membrane fractions, but this contamination has been estimated to be only 5%. On the basis on enzyme assays, the plasma membrane fractions contain all the 5'-nucleotidase activity in the final gradients and are free of catalase, acid phosphatase and malate dehydrogenase activity (markers for peroxisomes, lysosomes, soluble enzymes and the matrix of mitochondria). Their content of glucose-6-phosphatase is reduced by more than 70%. The large majority of RNA and DNA have been removed from the preparation.

Regression of NMU-induced mammary tumors with the combination of melatonin and 9-cis-retinoic acid

A significant increase in tumor regression was induced in N-nitroso-N-methylurea-induced mammary tumors in rats treated with the combination of melatonin and 9-cis-retinoic acid (9cRA). Treatment groups included: control (ethanolic saline), 9cRA (30 mg/kg chow/day), melatonin 500 microg/day, melatonin 1000 microg/day, melatonin 500 microg/day+9cRA and melatonin 1000 microg/day+9cRA. Rats treated with the lower dose of melatonin 500 microg+9cRA show the greatest degree of tumor regression (78%), with 54% undergoing complete regression and a significant increase in apoptotic cells observed by TUNEL Assay. Furthermore, tumor multiplicity and burden were significantly decreased by the combination of melatonin and 9cRA.

The canine telomerase catalytic subunit (dogTERT): Characterisation of the gene promoter and identification of proximal core sequences necessary for specific transcriptional activity in canine telomerase positive cell lines

Telomerase biology is complicated by studies that show that telomere expression and telomere biology differs between species, and that existing animal models do not closely resemble the human situation. We have previously reported a description of telomere/telomerase biology in the dog and have suggested this as an alternative model system. To further elucidate telomerase biology in this species we have cloned and characterised the canine reverse transcriptase (dogTERT) promoter. We demonstrate that core promoter activity is contained within a region extending approximately 300 bp upstream of the ATG codon. Transient transfections in telomerase-positive canine cell lines and telomerase negative fibroblasts showed that the promoter is only active in telomerase positive cell lines. Sequence analysis demonstrated that the 5' regulatory region is GC-rich and contains no TATA or CAAT box, similar to the human TERT promoter. Motif searches revealed the presence of multiple transcription factor binding sites common to both the human and canine TERT promoters, including a single E-box, Sp1, AP1, MZF-2 and ER/Sp1 binding sites. These findings suggest that the dogTERT gene shares similar transcriptional control to hTERT. Identification of the core promoter necessary for activity may allow the use of naturally occurring cancers in dogs as a preclinical testing ground for telomerase targeted therapies in human cancer patients.

The pharmacist's role in primary care within an integrated health system

I read, with interest, the paper by Rosser and Kasperski. I was struck by how similar and applicable the problems and issues identified for family physicians are to those pharmacists face today in Canada's health system. There is a need for a coordinated and systematic approach to address infrastructure support for all primary-care providers. In this companion article, I will provide evidence to support the Ontario College of Family Physicians' position on strengthening family physicians' abilities to provide excellent primary care. In addition, I will make a case for support of greater involvement of pharmacists in community-based primary-care teams.

Satisfying the patient in primary care: a postal survey following a recent consultation

BACKGROUND

Factors over and above the skills of the health care professional appear to impact on how well patients can cope with an illness following a consultation in general practice. These other factors appear to relate to the organisation and fabric of the doctor's practice. This study reports a systematic analysis of responses to a questionnaire survey of patients following a telephone consultation in a general practice setting. This study aims to explore how views on specific aspects of a general practice service contrast among patients.

METHODS

A structured anonymised postal questionnaire was sent to 916 patients within 24 h of a telephone consultation with a doctor or nurse in five general practices in North Trent, UK. No reminders were sent. Included on the questionnaire were free-text questions that invited opinions on areas for improvement for the patients' registered practice. These were analysed qualitatively using content analysis by two independent researchers.

RESULTS

The overall response rate was 52% although responses from young men were under-represented in the survey. One in three responders expressed a need for improvements in the appointments, more access and less delay before practice. Five themes and a number of sub-themes were identified. Patients wanted more appointments. Other themes included a desire for better communication, more patient friendly policies and facilities. Analysis suggests that it would be very difficult to satisfy the contrasting and divergent needs of all patients.

CONCLUSIONS

Communication with patients in general practice is influenced by the fabric, policies and reception staff in the practice as much as by the skills and resources of the care provider. Seeking patients' opinions about the practice within the context of a recent telephone consultation unearthed conflicting desires that cannot be satisfied given existing resources in the National Health Service (NHS). Patients favour a speedy, convenient and above all, tailored service. This may be impossible to deliver universally. Attention to the non-doctor aspects of the service may enhance the ability of practitioners to enable patients to cope with illness. The data suggest that patients are not universally satisfied with the service provided and that it would be naive to attempt to please them all.

A Southpaw Joins the Roster: The Role of the Zebrafish nodal-related Gene Southpaw in Cardiac LR Asymmetry

The establishment of the left-right (LR) asymmetry of the zebrafish heart involves at least two discrete events: cardiac jogging and cardiac looping. The nodal-related gene southpaw is required for both aspects of heart LR asymmetry as well as for LR patterning of other visceral organs. Reductions in southpaw activity abolish the normal LR biases of jogging and looping and uncouple the normal correlation between jogging and looping polarities. These loss-of-function experiments also reveal that southpaw is required for organizing at least the initial phase of diencephalic LR asymmetry and suggest that heart and brain LR patterning may be coordinated by southpaw signaling originating within the anterior, left lateral plate mesoderm.

Guidelines on the management of secondary prophylaxis of vascular events in stable patients in primary care

Atherothrombosis, thrombus formation superimposed on an existing atherosclerotic plaque, is an acute process leading to ischaemic events such as myocardial infarction, stroke and critical limb ischaemia. Patients presenting with clinical conditions associated with atherothrombosis are at increased risk of subsequent vascular events. The beneficial effect of antiplatelet therapies for short-term and long-term secondary prevention of atherothrombotic events has been established. These guidelines aim to provide evidence-based recommendations that will assist in the antiplatelet-mediated secondary prophylaxis of vascular events in patients with stable cardiovascular disease treated in the primary healthcare setting. Medline and the Cochrane library were accessed using free-text strategies in the domains of antiplatelet agents and antithrombotics. Development of the guidelines was driven by a series of Steering Committee meetings, in which the quality of relevant studies was assessed and identified using narrative summary. These guidelines present evidence and recommendations for the treatment of numerous atherothrombotic indications depending on individual patient circumstances.

Preconception care: practice and beliefs of primary care workers

BACKGROUND

A number of lifestyle modifications and medical interventions can be of benefit to maternal and neonatal health, when applied prior to conception. These include smoking cessation, supplementation with folic acid, cessation or moderation of alcohol intake and improvement of diabetic control. However, preconception care (PCC) is not widely practised in the UK, despite being apparently acceptable to health professionals and to women of childbearing age.

OBJECTIVES

The aims of the study were to describe the current practice of PCC in Barnsley and to assess the beliefs and attitudes of primary health care practitioners. This information would help direct appropriate educational and clinical governance intervention to this service in the locality in the light of other evidence about the effectiveness of PCC.

METHODS

A questionnaire was devised to explore the beliefs about, and practice in providing, PCC in primary care in the Barnsley Health Authority area and sent to all known GPs, practice nurses (PNs), health visitors (HVs) and midwives (MWs) in practices in the area in July 2000. A total of 163 completed questionnaires were received (one reminder, response rate 60.1%).

RESULTS

Few practices had a written policy on PCC. Most respondents were providing it mainly on an opportunistic basis and had done so less than five times in the previous 3 months; GPs and PNs were most commonly involved. They agreed that advice about smoking, drug use, folic acid, genetic counselling, chronic disease, alcohol, and maternity care and screening for rubella, genital infections, hepatitis, human immunodeficiency virus and cervical cytology were important. They felt that advice about diet, exercise, supplements, food safety, occupational hazards and State benefits, and screening for nutritional status were less important. Although respondents felt that PCC was effective, and important to women of childbearing age, it was not a high priority in their workload. They indicated that this care was best provided in general practice and that they had the appropriate skills. Barriers to providing PCC included lack of resources and lack of contact with women planning to conceive. Few had received any training on PCC since qualifying in their discipline.

CONCLUSIONS

The practitioners who responded to this survey agreed to a large extent about the importance of the subject, and about the content and effectiveness of PCC. Factors hindering the delivery of this service include resource constraints, lack of training and practice policies and procedures, and difficulty in targeting couples planning conception. Further research is needed into ways to increase the provision and uptake of PCC.

Development and performance of the vehicle-mounted radiation monitoring equipment used in the Maralinga rehabilitation project

The rehabilitation of the former nuclear test site at Maralinga involved (among other processes) the removal of contaminated soil from an area of approximately 2.5 km2. The two most stringent rehabilitation criteria required measurements to ensure that no radioactive particle exceeding 100 kBq of 241Am activity, and no area of 1 ha exceeding 3 kBq/m2 of 241Am activity, remained in the rehabilitated area. The project timetable required that the area be scanned at the rate of approximately 3 ha/day. Two vehicle-mounted detection systems were developed and constructed to obtain the necessary measurements in the available timeframe. The scientific basis for the designs are presented, together with details of the selected equipment and technical solutions found. The performance of this equipment in the field is discussed in terms of both its scientific and technical operation. Based on the experience gained at Maralinga, improved versions of this equipment were produced under contract for the People's Republic of China.

Molecular identification and expression analysis of tumor necrosis factor in channel catfish (Ictalurus punctatus)

A tumor necrosis factor (TNF) alpha-like gene, encoding a propeptide of 230 amino acids and a mature (soluble) peptide of 162 amino acids, was identified in channel catfish (Ictalurus punctatus). While the catfish protein shared features in common with both mammalian TNFalpha and TNFbeta homologs, overall sequence identity/similarity was slightly higher vs. TNFalpha genes when mature TNF sequences were compared. Phylogenetic analysis placed catfish and other fish TNF sequences within their own cluster apart from mammalian TNFalpha and beta genes, and supported the suggestion that TNFalpha and beta genes separated after the divergence of mammals and teleosts. In contrast to trout and carp, but similar to flounder, catfish TNF was present as a single copy gene. Expression studies demonstrated that catfish TNFalpha mRNA was present in all tested tissues (i.e. liver, spleen, head kidney, mesonephros, gill, thymus, and PBLs) from an unstimulated fish. Moreover, catfish TNF was constitutively expressed in actively proliferating, but otherwise unstimulated, macrophage (42TA) and T cell (G14D; TS32.17) lines, but not in B cell (1G8 or 3B11) or fibroblast lines. TNF expression was upregulated in PBLs, and in G14D and 42TA cells, but not in 3B11 cells, by PMA/calcium ionophore treatment. These results demonstrate that a catfish homolog of TNFalpha has been identified, and indicate that catfish TNFalpha is expressed in catfish in a manner similar to that seen in mammals.

The zebrafish nodal-related gene southpaw is required for visceral and diencephalic left-right asymmetry

We have identified and characterized a new zebrafish gene, southpaw, that is required for visceral and diencephalic left-right asymmetry. southpaw encodes a new member of the nodal-related class of proteins, a subfamily within the transforming growth factor beta superfamily of secreted factors. southpaw is expressed bilaterally in paraxial mesoderm precursors and then within the left lateral plate mesoderm. At late somite stages, left-sided southpaw expression transiently overlaps the left-sided expression domains of other genes that mark the developing heart, such as lefty2. We have injected morpholinos to block the translation of the southpaw mRNA or to block splicing of the southpaw pre-mRNA. These morpholinos cause a severe disruption of early (cardiac jogging) and late (cardiac looping) aspects of cardiac left-right asymmetry. As the left-right asymmetry of the pancreas is also affected, southpaw appears to regulate left-right asymmetry throughout a large part of the embryo. Consistent with the morphological changes, the left-sided expression domains of downstream genes (cyclops, pitx2, lefty1 and lefty2) are severely downregulated or abolished within the lateral plate mesoderm of Southpaw-deficient embryos. Surprisingly, despite the absence of southpaw expression in the brain, we find that early diencephalic left-right asymmetry also requires Southpaw activity. These observations lead to a model of how visceral organ and brain left-right asymmetry are coordinated during embryogenesis.

Effects of high-calorie supplements on body composition and muscular strength following resistance training

BACKGROUND

Seventy-three healthy, male subjects randomly divided into 3 groups participated in a study to determine the effects of 2 high-calorie nutritional supplements on body composition, body segment circumferences, and muscular strength following a resistance-training (RT) program.

METHODS

In addition to their normal diets group 1 (CHO/PRO; n=26) consumed a 8.4 Mj x day(-1) (2010 kcal) high calorie, high protein supplement containing 356 g carbohydrate and 106 g protein. Group 2 (CHO; n=25) consumed a carbohydrate supplement that was isocaloric with CHO/PRO. Group 3 (CTRL; n=22) received no supplement and served as a control. All subjects were placed on a 4-day x week(-1) RT program for 8 weeks.

RESULTS

Dietary analysis revealed no significant differences in total energy consumption or nutrients at any time in the non-supplemented diets of the 3 groups. Significant (p= or <0.05) increases in body mass (BM) and fat-free mass (FFM) were observed in CHO/PRO and CHO compared to CTRL. Mean (+/- SD) increases in BM were 3.1+/-3.1 kg and 3.1+/-2.2 kg, respectively. Fat-free mass significantly (p= or <0.05) increased 2.9+/-3.4 kg in CHO/PRO and 3.4+/-2.5 kg in CHO. Muscular strength, as measured by a one-repetition maximum in the bench press, leg press, and lat-pull down increased significantly (p= or <0.05) in all groups. No significant differences in strength measures were observed among groups following training.

CONCLUSIONS

Results indicate that high-calorie supplements are effective in increasing BM and FFM when combined with RT. However, once individual protein requirements are met, energy content of the diet has the largest effect on body composition.

Improving the quality of care of musculoskeletal conditions in primary care

OBJECTIVE

To determine the support services general practitioners (GPs) need when working with patients who have musculoskeletal problems and their educational needs in order to deliver an improved service.

METHODS

GPs (n=446) on the Sheffield and Barnsley principal lists were sent a questionnaire (53.8% response rate). Semistructured interviews of a purposive sample of 10 GPs were analysed qualitatively to increase understanding of the research objectives.

RESULTS

GPs were self-confident in managing common musculoskeletal conditions such as gout (86% of GPs who replied), back pain (69%), osteoarthritis (62%) and sporting injuries (58%) entirely within the surgery. Despite high levels of confidence in diagnosing non-specific pain syndromes, 68% of GPs would refer to a rheumatologist. Most GPs (68%) were happy with their current referral rates to physiotherapists and 65% of GPs in this sample provided a personal injection service. Reduction of inappropriate prescribing of non-steroidal anti-inflammatory drugs would be helped by better patient education materials on treatments (90%) and more resources for the primary care physiotherapy service (85%). Half of the GPs had had specific musculoskeletal training within the last 5 yr. Half of the GPs planned to update their knowledge and skills in the next year, 64% of these preferring a taught interactive course, 50% wanting to sit in with a consultant in clinic and 46% preferring to learn as part of a personal learning plan.

CONCLUSIONS

GPs feel confident managing the majority of musculoskeletal conditions within the surgery provided they have adequate support in terms of opportunities for appropriate education, particularly joint injection techniques, ongoing consultant support for complex cases with poor outcomes, particularly non-specific pain syndromes, adequate access to physiotherapy, and a multidisciplinary approach to pain control and inappropriate prescribing.