Interleukin-10 gene-deficient mice develop a primary intestinal permeability defect in response to enteric microflora

The normal intestinal epithelium provides a barrier relatively impermeable to luminal constituents. However, patients with inflammatory bowel disease experience enhanced intestinal permeability that correlates with the degree of injury. IL-10 gene-deficient mice were studied to determine whether increased intestinal permeability occurs as a primary defect before the onset of mucosal inflammation or is secondary to mucosal injury. At 2 weeks of age, IL-10 gene-deficient mice show an increase in ileal and colonic permeability in the absence of any histological injury. This primary permeability defect is associated with increased mucosal secretion of interferon-gamma and tumor necrosis factor-alpha, and does not involve an increase in nitric oxide synthase activity. Colonic permeability remains elevated as inflammation progresses, while ileal permeability normalizes by 6 weeks of age. IL-10 gene-deficient mice raised under germ-free conditions have no inflammation, and demonstrate normal permeability and cytokine levels. This data suggests that the intestinal permeability defect in IL-10 gene-deficient mice occurs due to a dysregulated immune response to normal enteric microflora and, furthermore, this permeability defect exists prior to the development of mucosal inflammation.

Interleukin-10 gene-deficient mice develop a primary intestinal permeability defect in response to enteric microflora

The normal intestinal epithelium provides a barrier relatively impermeable to luminal constituents. However, patients with inflammatory bowel disease experience enhanced intestinal permeability that correlates with the degree of injury. IL-10 gene-deficient mice were studied to determine whether increased intestinal permeability occurs as a primary defect before the onset of mucosal inflammation or is secondary to mucosal injury. At 2 weeks of age, IL-10 gene-deficient mice show an increase in ileal and colonic permeability in the absence of any histological injury. This primary permeability defect is associated with increased mucosal secretion of interferon-gamma and tumor necrosis factor-alpha, and does not involve an increase in nitric oxide synthase activity. Colonic permeability remains elevated as inflammation progresses, while ileal permeability normalizes by 6 weeks of age. IL-10 gene-deficient mice raised under germ-free conditions have no inflammation, and demonstrate normal permeability and cytokine levels. This data suggests that the intestinal permeability defect in IL-10 gene-deficient mice occurs due to a dysregulated immune response to normal enteric microflora and, furthermore, this permeability defect exists prior to the development of mucosal inflammation.

Dendritic cell-derived IL-12 promotes B cell induction of Th2 differentiation: a feedback regulation of Th1 development

B cells convert what are normally conditions for Th1 differentiation into an environment suitable for Th2 development. This capacity is dependent on CD40 as B cells from CD40-/- mice do not elicit Th2 differentiation. To elucidate the basis of this effect, we surveyed cytokine RNA made by naive B cells after activation with anti-Ig and anti-CD40. Resting B cells make TGF-beta message only, however, 4 days after activation, RNA encoding IL-6, IL-10, and TNF-alpha was found. The expression of these messages was accelerated by 2 days in the presence of IL-12. The relevance of these observations to T cell differentiation was investigated: addition of OVA peptide to splenic cells from DO.11.10 transgenic mice causes most T cells to make IFN-gamma. Coactivation of B cells in these cultures reduces the number of IFN-gamma-producing T cells and increases the number synthesizing IL-4. Abs to IL-6 and IL-10 block the IL-4 enhancement. Dissection of the component APC demonstrated that interaction of B cells with IL-12-producing dendritic cells is crucial for B cell-mediated IL-4 enhancement: Thus, B cells preactivated in the presence of dendritic cells from IL-12-/- mice show little IL-4-inducing activity when used to activate T cells. This immune regulation is initiated by IL-12 and therefore represents a feedback loop to temper its own dominant effect (IFN-gamma induction).

Cardiac rehabilitation: socially deprived patients are less likely to attend but patients ineligible for thrombolysis are less likely to be invited

OBJECTIVE

To identify factors associated with the uptake of cardiac rehabilitation following acute myocardial infarction.

DESIGN

Retrospective analysis using multivariate logistic regression modelling.

SETTING

Two large teaching hospitals in Nottingham.

PATIENTS

Cohorts of patients admitted with acute myocardial infarction in 1992 and 1996.

INTERVENTIONS

None.

MAIN OUTCOME MEASURES

Factors in multivariate analysis found to be associated with attendance at cardiac rehabilitation. Use of secondary prevention in those who were and were not invited and those who did and did not attend cardiac rehabilitation.

RESULTS

58% of all patients were offered cardiac rehabilitation. Attendance rates were 60% in 1992 and 74% in 1996. Invitations were more likely to be offered to younger patients, those who had received thrombolysis, and to patients admitted to one of the two Nottingham hospitals. Use of secondary prevention was only 48% in 1992 but this increased to 80% in 1996. Patients not receiving secondary prevention were less likely to be invited to cardiac rehabilitation. Social deprivation was the only factor significantly associated with poor uptake of cardiac rehabilitation in both years. There was no difference in the use of secondary prevention between those who did and did not attend cardiac rehabilitation.

CONCLUSION

Those invited to attend a cardiac rehabilitation programme are likely to be in a good prognosis group, comprising those who are young and have received thrombolysis. Those at greatest risk, particularly patients from socially deprived areas, seem to be missing out on the potential benefits of cardiac rehabilitation. High risk patients should be specifically targeted to ensure that they are invited to, and encouraged to, attend a programme of cardiac rehabilitation.

A YAC-based physical map of the mouse genome

A physical map of the mouse genome is an essential tool for both positional cloning and genomic sequencing in this key model system for biomedical research. Indeed, the construction of a mouse physical map with markers spaced at an average interval of 300 kb is one of the stated goals of the Human Genome Project. Here we report the results of a project at the Whitehead Institute/MIT Center for Genome Research to construct such a physical map of the mouse. We built the map by screening sequenced-tagged sites (STSs) against a large-insert yeast artificial chromosome (YAC) library and then integrating the STS-content information with a dense genetic map. The integrated map shows the location of 9,787 loci, providing landmarks with an average spacing of approximately 300 kb and affording YAC coverage of approximately 92% of the mouse genome. We also report the results of a project at the MRC UK Mouse Genome Centre targeted at chromosome X. The project produced a YAC-based map containing 619 loci (with 121 loci in common with the Whitehead map and 498 additional loci), providing especially dense coverage of this sex chromosome. The YAC-based physical map directly facilitates positional cloning of mouse mutations by providing ready access to most of the genome. More generally, use of this map in addition to a newly constructed radiation hybrid (RH) map provides a comprehensive framework for mouse genomic studies.

Neurochemical organization of inferior pulvinar complex in squirrel monkeys and macaques revealed by acetylcholinesterase histochemistry, calbindin and Cat-301 immunostaining, and Wisteria floribunda agglutinin binding

To investigate whether the inferior pulvinar complex has a common organization in different primates, the chemoarchitecture of the visual thalamus was re-examined in squirrel monkeys (Saimiri sciureus) and macaques (Macaca mulatta). The inferior pulvinar (PI) complex consisted of multiple subdivisions and encompassed the classic PI, and adjacent ventral parts of the lateral and medial pulvinar (PL and PM, respectively). In keeping with nomenclature suggested previously for macaques, the PI subdivisions were termed the posterior, medial, central, lateral, and lateral-shell (PI(P), PI(M), PI(C), PI(L), and PI(L-S)). In both species, PI(P) was intense for calbindin, light for acetylcholinesterase (AChE), and very light for Wisteria floribunda agglutinin (WFA) histochemistry. The PI(M) was calbindin poor, AChE rich, and moderate for WFA. The PI(C) was calbindin intense, lighter for AChE, and exhibited little WFA binding. PI(L) and PI(L-S) contained populations of large calbindin or WFA cells that were more numerous in PI(L-S). Although staining with the monoclonal antibody Cat-301 differed between macaques and squirrel monkeys, the same subdivisions were displayed. Moderately dense, patchy Cat-301 stain was found in PI(M) of macaques, whereas in squirrel monkeys PI(M) was light. Connections of the rostral dorsolateral (DLr) and middle temporal (MT) areas of visual cortex in squirrel monkeys were compared with PI subdivisions revealed by the newer histochemical methods in the same cases. The major connections of DLr were with PI(C) and of MT were with PI(M).

Relevance of clinical trial results in myocardial infarction to medical practice: comparison of four year outcome in participants of a thrombolytic trial, patients receiving routine thrombolysis, and those deemed ineligible for thrombolysis

OBJECTIVE

To assess the medium to long term outcome of patients ineligible for thrombolysis compared to those enrolled in a clinical trial of thrombolysis and patients receiving non-trial thrombolysis.

DESIGN

Cohort study based on the Nottingham heart attack register.

SETTING

Two district general hospitals serving a defined urban/rural population.

SUBJECTS

All patients admitted with a confirmed acute myocardial infarction during 1992 categorised as either participants of a thrombolytic trial (group A, n = 140), receiving non-trial thrombolysis (group B, n = 329), or deemed ineligible for lytic treatment (group C, n = 431).

MAIN OUTCOME MEASURES

Background characteristics, inhospital treatment, patterns of follow up, referrals to cardiologists, revascularisation rates, and short and long term survival.

RESULTS

Clinical trial recruits were younger by almost 10 years, were less likely to have a previous history of myocardial infarction, and more likely to be in Killip class 1 on admission than those ineligible for thrombolysis. Cardiology follow up was mandatory for all surviving trial participants but 22% of patients in group B and 31% of patients in group C received no follow up, and during four years less than 50% ever saw a cardiologist. Revascularisation was performed in 17.2% of patients in group A, 13.6% of patients in group B, and 7.5% of patients in group C. Cumulative mortality at a median of four years was 24.3% in group A, 36.8% in B, and 59.6% in group C. Adjusting for age, sex, previous myocardial infarction, type of infarction, and Killip class in a logistic regression model the odds ratios (OR) of death at four years for groups B and C were 1.60 (95% confidence intervals (CI) 0.97 to 2.63, p = 0.065) and 2.64 (95% CI 1.61 to 4. 32, p < 0.001), respectively, when compared to group A (OR 1).

CONCLUSIONS

Patients enrolled into thrombolytic trials are at low risk. Patients deemed ineligible for thrombolysis are high risk, receive less surveillance, are less likely to be revascularised or receive trial proven treatments, have a poor long term outcome not entirely explained by increased age or severity of infarction, and deserve further evaluation.

Moving beyond information: evaluation of a nutrition education tool based on a theoretical model

OBJECTIVE

This study investigated the relative effectiveness of a nutrition education brochure based on a theoretical model versus a more traditional information-based brochure in getting subjects to accurately assess daily calcium intake, make a plan to increase intake if needed, and to implement the plan.

DESIGN

A randomized trial involving 216 women between the ages of 19-49y. Subjects were randomly assigned to a group which received educational materials containing an interactive brochure designed using the Motivation Generating model (Calcium CalculatorS), or to a group which received a calcium information brochure (An Appetite for Good Health). Within a two week period the women were contacted by telephone to assess use of materials, calcium intake assessment information, and plans for dietary change.

SETTING

Subjects were recruited at five fitness centres in the Vancouver area. The research was conducted by the Institute of Health Promotion Research at the University of British Columbia.

RESULTS

Results indicated significantly greater numbers of subjects conducting self- assessment and increased group accuracy for calcium intake assessment in subjects using the interactive brochure.

CONCLUSION

Use of a theoretical model designed to create behaviour change such as the Motivation Generating Model can increase specific behaviours which may lead to improvements in dietary consumption.

Pressure ulcer prevention and treatment: the Transair range

The Transair range has been updated as a result of clinical and technical advances. The Transair 500 cushion system utilizes foam and air technology to minimize disturbance to the user. Clinical trials suggest that this cushion is of benefit in both the prevention and treatment of pressure ulcers. The Transair 1001 alternating pressure air overlay and the Transair 2002 mattress replacement have both been revised to provide improved performance and both have been subjected to clinical trials. The results of these trials suggest that both have a role in the prevention and treatment of pressure sores in the individual in the high/very high risk group. This article examines these innovations in the Transair mattress and seating systems.

Influence of ambulance crew's length of experience on the outcome of out-of-hospital cardiac arrest

AIMS

To investigate whether an ambulance crew's length of experience affected the outcome of out-of-hospital cardiac arrest.

METHODS AND RESULTS

This was a population-based, retrospective observational study of attempted resuscitations in 1547 consecutive arrests of cardiac aetiology by Nottinghamshire Emergency Ambulance Service crew. One thousand and seventy-one patients were managed by either a paramedic or a technician crew without assistance from other trained individuals at the scene of arrest. Overall, the chances of a patient surviving to be discharged from hospital alive did not appear to be affected by the paramedic's length of experience (among survivors, 18 months experience vs non-survivors 16 months experience, P = 0.347) but there appears to be a trend in the effect of a technician's length of experience on survival (among survivors, 60 months experience vs non-survivors 28 months experience, P = 0.075). However, when a technician had 4 years of experience or more and a paramedic 1 year's experience, survival rates did improve. Logistic regression analysis, adjusted for factors known to influence outcome, revealed that chances of survival increased once technicians had over 4 years of experience after qualification (odds ratio 2.71, 95% CI 1.17 to 6.32, P = 0.02) and paramedics after just 1 year of experience (odds ratio 2.68, 95% CI 1.05 to 6.82, P = 0.04).

CONCLUSIONS

Survival from out-of-hospital cardiac arrest varies with the type of ambulance crew and length of experience after qualification. Experience in the field seems important as paramedics achieve better survival rates after just 1 year's experience, while technicians need to have more than 4 years' experience to improve survival.

Quality of life four years after acute myocardial infarction: short form 36 scores compared with a normal population

OBJECTIVES

To assess the impact of myocardial infarction on quality of life in four year survivors compared to data from "community norms", and to determine factors associated with a poor quality of life.

DESIGN

Cohort study based on the Nottingham heart attack register.

SETTING

Two district general hospitals serving a defined urban/rural population.

SUBJECTS

All patients admitted with acute myocardial infarction during 1992 and alive at a median of four years.

MAIN OUTCOME MEASURES

Short form 36 (SF 36) domain and overall scores.

RESULTS

Of 900 patients with an acute myocardial infarction in 1992, there were 476 patients alive and capable of responding to a questionnaire in 1997. The response rate was 424 (89. 1%). Compared to age and sex adjusted normative data, patients aged under 65 years exhibited impairment in all eight domains, the largest differences being in physical functioning (mean difference 20 points), role physical (mean difference 23 points), and general health (mean difference 19 points). In patients over 65 years mean domain scores were similar to community norms. Multiple regression analysis revealed that impaired quality of life was closely associated with inability to return to work through ill health, a need for coronary revascularisation, the use of anxiolytics, hypnotics or inhalers, the need for two or more angina drugs, a frequency of chest pain one or more times per week, and a Rose dyspnoea score of >/= 2.

CONCLUSIONS

The SF 36 provides valuable additional information for the practising clinician. Compared to community norms the greatest impact on quality of life is seen in patients of working age. Impaired quality of life was reported by patients unfit for work, those with angina and dyspnoea, patients with coexistent lung disease, and those with anxiety and sleep disturbances. Improving quality of life after myocardial infarction remains a challenge for physicians.

Statin prescribing in Nottingham general practices: a cross-sectional study

BACKGROUND

The aim of the study was to determine the effect of deprivation on variations in statin prescribing in Nottingham general practices. Deprivation is used as a measure of population cardiovascular morbidity and need for statin treatment. The setting was all 118 general practices in contract with Nottingham Health Authority.

METHODS

A cross-sectional study was undertaken. Statin prescribing in general practice during 1996 was related to indices of practice deprivation based on enumeration district (ED) level data from the 1991 Census. The relationship between statin prescribing per 1000 patients aged 35-69 and practice deprivation (measured both as Townsend score and as Jarman UPA(8) score) with additional adjustment for practice characteristics (number of partners, training status, total list size, fundholding status) cardiovascular prescribing costs net of lipid prescribing and hospital activity (total and medical admissions and new general practitioner total and medical out-patient referrals) for each practice.

RESULTS

The prescription of statins during 1996 varied between nil and 14.1 'statin-years' of prescribing per 1000 patients aged 35-69. There was a significant inverse relationship between the rate of statin prescribing and the level of deprivation of that practice (p < 0.0001). Deprivation, as measured by Townsend index, accounted for 13 per cent of the total variability in statin prescribing, which rose to 19 per cent after adjustment. The prescribing of other lipid lowering agents of the fibrate class was positively associated with statin prescribing (p=0.001) and this association persisted after adjusting for deprivation. None of the other practice characteristics were found to be significantly associated with rates of statin prescribing.

CONCLUSIONS

General practices with high deprivation indices serve more deprived populations with a higher prevalence of cardiovascular disease, and may be assumed to have a greater need for statins. Despite this, practices with higher deprivation indices prescribed fewer statins to their patients than less deprived practices. It was not possible to identify whether the more deprived general practices had successfully identified at risk individuals but it is likely that special efforts are needed to increase the uptake of effective health care in their patients.

Subdivisions of the motor and somatosensory thalamus of primates revealed with Wisteria floribunda agglutinin histochemistry

We obtained well-differentiated staining of thalamic subdivisions in rhesus macaques and squirrel monkeys using a lectin, Wisteria floribunda agglutinin (WFA), that labels extracellular matrix proteoglycans. Regional variations in staining were observed within the motor and somatosensory thalamic regions that bear on current interpretations of the organization of these regions. The pattern of WFA staining was generally similar to that obtained with Cat-301 antibody, which also stains proteoglycans. However, WFA reliably produced selective staining in both squirrel monkeys and macaques, whereas Cat-301 stained macaques more consistently than squirrel monkeys.

Resuscitation from out-of-hospital cardiac arrest: is survival dependent on who is available at the scene?

OBJECTIVE

To determine whether survival from out-of-hospital cardiac arrest is influenced by the on-scene availability of different grades of ambulance personnel and other health professionals.

DESIGN

Population based, retrospective, observational study.

SETTING

County of Nottinghamshire with a population of one million.

SUBJECTS

All 2094 patients who had resuscitation attempted by Nottinghamshire Ambulance Service crew from 1991 to 1994; study of 1547 patients whose arrest were of cardiac aetiology.

MAIN OUTCOME MEASURES

Survival to hospital admission and survival to hospital discharge.

RESULTS

Overall survival from out-of-hospital cardiac arrest remains poor: 221 patients (14.3%) survived to reach hospital alive and only 94 (6.1%) survived to be discharged from hospital. Multivariate logistic regression analysis showed that the chances of those resuscitated by technician crew reaching hospital alive were poor but were greater when paramedic crew were either called to assist technicians or dealt with the arrest themselves (odds ratio 6.9 (95% confidence interval 3.92 to 26.61)). Compared to technician crew, survival to hospital discharge was only significantly improved with paramedic crew (3.55 (1.62 to 7.79)) and further improved when paramedics were assisted by either a health professional (9.91 (3.12 to 26.61)) or a medical practitioner (20.88 (6.72 to 64.94)).

CONCLUSIONS

Survival from out-of-hospital cardiac arrest remains poor despite attendance at the scene of the arrest by ambulance crew and other health professionals. Patients resuscitated by a paramedic from out-of-hospital cardiac arrest caused by cardiac disease were more likely to survive to hospital discharge than when resuscitation was provided by an ambulance technician. Resuscitation by a paramedic assisted by a medical practitioner offers a patient the best chances of surviving the event.

CD40 ligand signals optimize T helper cell cytokine production: role in Th2 development and induction of germinal centers

The role of CD40 in the development of germinal centers (GC) is not simply to initiate the B cell response, as rudimentary GC can develop in CD40-/- mice that are injected with CD40-immunoglobulin (Ig) fusion protein. This indicates that CD40 ligand (CD40L) transduces a signal to T cells that is important in the process. In this study we have used an in vitro model of GC development to investigate the role of CD40L, cytokines and other co-stimuli. The model involves the specific induction of an H-2E transgene in GC B cells (in Sma58 mice). We find that Th2 cytokines together with Ig and CD40 cross-linking are the most efficient means of induction of the GC phenotype. Although IL-4 plays some inductive role, it is not the sole active ingredient in the mix of cytokines made by Th2 cells. Our studies on primary T cells and T cell clones activated in the absence of CD40 on antigen-presenting cells or CD40L on T cells indicate that the CD40L co-stimulus does not directly bias the response to Th2 cells, as previously reported, but that it augments terminal effector T cell differentiation or the level of secretory activity. However, both in vitro and in vivo, the CD40L co-stimulus is crucially important for Th2 development as in its absence IL-4 production is suboptimal and does not compete with a larger, more rapid IFN-gamma response.

T cell-dependent immune response in C1q-deficient mice: defective interferon gamma production by antigen-specific T cells

The role of the classical complement pathway in humoral immune responses was investigated in gene-targeted C1q-deficient mice (C1qA-/-). Production of antigen-specific immunoglobulin (Ig)G2a and IgG3 in primary and secondary responses to T cell-dependent antigen was significantly reduced, whereas IgM, IgG1, and IgG2b responses were similar in control and C1qA-/- mice. Despite abnormal humoral responses, B cells from C1qA-/- mice proliferated normally to a number of stimuli in vitro. Immune complex localization to follicular dendritic cells within splenic follicles was lacking in C1qA-/- mice. The precursor frequency of antigen-specific T cells was similar in C1qA-/- and wild-type mice. However, analysis of cytokine production by primed T cells in response to keyhole limpet hemocyanin revealed a significant reduction in interferon-gamma production in C1qA-/- mice compared with control mice, whereas interleukin 4 secretion was equivalent. These data suggest that the classical pathway of complement may influence the cytokine profile of antigen-specific T lymphocytes and the subsequent immune response.

Operative outcomes of minimally invasive saphenous vein harvest

BACKGROUND

The longest incision used in surgery is the standard incision for harvesting the greater saphenous vein for arterial grafting. This long incision is associated with significant pain and morbidity. We present a comparative study between two relatively less invasive techniques: the standard bridge technique (BT) and the endoscopic saphenous vein harvest (ESVH).

PATIENTS AND METHODS

This is a prospective, nonrandomized, case-matched study of contemporaneous minimally invasive saphenous vein harvest in patients undergoing multiple vessel coronary artery bypass grafting (CABG). Data points include operative time, total wound length, length of vein harvested, intraoperative complications, conversions to open, injury to the graft, postoperative complications and hospital length of stay. Follow-up continued for 8 weeks postdischarge.

RESULTS

Within a 10-month period (July 1996 to May 1997), 60 saphenous vein harvests were performed, with 29 by BT and 31 by ESVH. Patient demographics were well matched, except for a larger number of patients with peripheral vascular disease in the ESVH group. ESVH only required 2.3 incisions versus 5 for the BT (P = 0.000001), whereas ESVH produced on average longer veins of 53.9 cm versus 47.7 cm for BT (P = 0.05). Harvest times were comparable in the two groups. However, mean vein preparation times, incision closure times, and total vein operative times for the BT were, respectively, 18.5 minutes, 35.1 minutes, and 94 minutes versus significantly less times of 11.3 minutes (P = 0.009), 10.6 minutes (P = 0.000001), and 73 minutes (P = 0.0001), respectively, for ESVH. The early, minor wound complication rate was 32% for the ESVH group versus 3% for the BT group (P = 0.0048). However, excluding small wound hematomas, the wound complication rate in the ESVH group fell to 13%. Graft quality was acceptable in both groups.

CONCLUSIONS

ESVH was demonstrated to be a useful procedure to harvest saphenous veins for CABG surgery. The ESVH technique allowed the harvesting of a longer vein, via shorter and fewer incisions and in less time. However, for maximum operating room efficiency with the new technology, staff education is essential. There was a greater incidence of minor wound complications in the ESVH group; however, the majority of these ESVH complications were small wound hematomas, which did not occur as surgeon experience with the technique increased.

Changes in the process of care for Medicaid patients with schizophrenia in Utah's Prepaid Mental Health Plan

OBJECTIVE

Changes in the process of psychiatric care received by Medicaid beneficiaries with schizophrenia were examined after the introduction of capitated payments for enrollees of some community mental health centers (CMHCs) under the Utah Prepaid Mental Health Plan.

METHODS

Data from the medical records of 200 patients receiving care in CMHCs participating in the prepaid plan were compared with data from the records of 200 patients in nonparticipating CMHCs, which remained in a fee-for-service reimbursement arrangement. Using the Process of Care Review Form, trained abstracters gathered data characterizing general patient management, social support, medication management, and medical management before implementation of the plan in 1990 and for three follow-up years. Using regression techniques, differences in the adjusted changes between third-year follow-up and baseline were examined by treatment site.

RESULTS

By year 3 at the CMHCs participating in the plan, psychotherapy visits decreased, the probability of a patient's terminating treatment or being lost to follow-up increased, the probability of having a case manager increased, the probability of a crisis visit decreased (but still exceeded that at the nonplan sites), and the probability of treatment for a month or longer with a suboptimal dosage of antipsychotic medication increased. Only modest changes in the process of care were observed at the nonplan CMHCs.

CONCLUSIONS

Change in the process of psychiatric care was more evident at the sites participating in the plan, where traditional therapeutic encounters were de-emphasized in response to capitation. The array of changes raises questions about the vigor of care provided to a highly vulnerable group of patients.

Therapeutic potential of recombinant p53 overexpression in breast cancer cells expressing endogenous wild-type p53

Reconstitution of the p53-dependent apoptotic pathway by gene transfer of a recombinant wild-type p53 minigene leads to rapid apoptotic cell death in breast and other cancer cell types expressing null or mutant p53. Tumour cells expressing wild-type p53 have been reported to be more resistant to this treatment strategy, presumably as a result of mutations in downstream regulators of p53-dependent apoptotic signalling. The MCF-7 breast cancer cell line is representative of this class of tumour cell. Our recent observation of a p53-dependent apoptotic response following adenovirus-mediated HSV thymidine kinase gene transfer and gancyclovir treatment led us to reexamine recombinant p53 cytotoxicity in MCF-7 cells. Infection with a recombinant adenovirus expressing wild-type p53 resulted in a dramatic increase in p53 protein levels and was accompanied by an increase in p21WAF/CIP1 protein levels and G1 arrest within 24 hours post-infection. A significant decrease in MCF-7 cell viability was first observed at 5 days post-infection and coincided with the appearance of morphological and biochemical changes consistent with apoptotic cell death. By day 7 post-treatment, cell viability decreased to 45% and clonogenic survival was reduced to 12% of controls. The results demonstrate that persistent, high level expression of recombinant p53 can induce programmed cell death in MCF-7 cells. While the mechanism by which p53 overexpression overcomes the defect in downstream apoptotic signalling is not clear, our data suggests that this treatment strategy may be beneficial for the class of tumour cells represented by the MCF-7 cell line.

Regulation of cytoplasmic, surface and soluble forms of CD40 ligand in mouse B cells

CD40 and CD40 ligand (CD40L) form one of most important receptor-ligand pairs that dock during T-B cell interactions as part of T-dependent antibody responses. It has been reported that among other cell types, B cells can express CD40L. Here we show that a large proportion of mouse B cells express CD40L in their cytoplasm, but not on the surface and that this is readily released as a soluble molecule. Thus, in their resting state up to 50% of mouse B cells express CD40L within their cytoplasm and both the proportion of cells expressing and the amount of CD40L is increased by signaling through immunoglobulin (Ig) or CD38. In contrast, T cell-derived signals such as CD40L (anti-CD40) or Th2-type cytokines cause a decrease in CD40L expression that is related to a release of a soluble form of the molecule from the cell. Supernatants from B cells activated with anti-Ig and anti-CD40 contain CD40L in a variety of forms (18 kDa, 33 kDa and 66 kDa) that are readily detectable by immunoprecipitation with CD40-Fc gamma fusion protein (CD40-Ig) followed by Western blotting with anti-CD40L antibody (MR1). The 33-kDa species is distinct from the 39-kDa membrane-bound molecule found in activated T cells or in resting B cells and appears to be a novel soluble form of CD40L. Inhibition of T cell-independent in vitro stimulation of B cells with CD40-Ig or anti-CD40L suggests that the B cell-derived soluble CD40L or CD40L expressed on the B cell surface can play a positive role in B cell proliferation.

Healthy or druggy? Self-image, ideal image and smoking behaviour among young people

Recent research indicates that there is an important, though complex, relationship between the social image of smoking and young people's self- and aspirational images. This study explored how young people see themselves (self-image), how they would like to be (ideal image), and whether these differ according to age, gender and smoking status. Focus groups were used to elicit attributes which young people use to describe smoking and non-smoking images taken from fashion pages in youth magazines. These attributes were incorporated into a self-completion questionnaire which was administered to 897 young people from three age groups (12-13 years, 15-16 years and 18-19 years). The respondents rated their self- and ideal images on each of these attributes. Overall, there were few differences between the rank order of attributes by age, sex or smoking status. However, there were differences in the trait scores, with males and smokers tending to rate themselves more positively. The two traits which most clearly differentiated smokers and non-smokers were druggy/takes drugs (self- and ideal image) and healthy (self-image). It appears that smokers in general, and male smokers in particular, embraced certain dimensions of self- and aspirational image of which druggy, tough and tarty are signifiers. In contrast, the differences between female smokers and non-smokers were less consistent and differed with age. The implications for health promotion are discussed.

Absorption and attenuation of visible and near-infrared light in water: dependence on temperature and salinity

We have measured the absorption coefficient of pure and salt water at 15 wavelengths in the visible and near-infrared regions of the spectrum using WETLabs nine-wavelength absorption and attenuation meters and a three-wavelength absorption meter. The water temperature was varied between 15 and 30 degrees C, and the salinity was varied between 0 and 38 PSU to study the effects of these parameters on the absorption coefficient of liquid water. In the near-infrared portion of the spectrum the absorption coefficient of water was confirmed to be highly dependent on temperature. In the visible region the temperature dependence was found to be less than 0.001 m-1 degrees C except for a small region around 610 nm. The same results were found for the temperature dependence of a saltwater solution. After accounting for index-of-refraction effects, the salinity dependence at visible wavelengths is negligible. Salinity does appear to be important in determining the absorption coefficient of water in the near-infrared region. At 715 nm, for example, the salinity dependence was -0.00027 m-1 /PSU. Field measurements support the temperature and salinity dependencies found in the laboratory both in the near infrared and at shorter wavelengths. To make estimates of the temperature dependence in wavelength regions for which we did not make measurements we used a series of Gaussian curves that were fit to the absorption spectrum in the visible region of the spectrum. The spectral dependence on temperature was then estimated based on multiplying the Gaussians by a fitting factor.

Determination of HLA-A*02 antigen status in Hodgkin's disease and analysis of an HLA-A*02-restricted epitope of the Epstein-Barr virus LMP-2 protein

There is good evidence for an association between Epstein-Barr virus (EBV) and Hodgkin's disease (HD). In approximately one-third of cases, the EBV genome is detectable in Reed-Sternberg (RS) cells and there is expression of the viral nuclear antigen EBNA-1 and the latent membrane protein LMP-1. Expression of LMP-2 has been demonstrated at the mRNA level, and it is presumed that the protein is expressed alongside LMP-1. The LMP-2 protein is known to contain an epitope presented to cytotoxic T-cells which is restricted through the HLA class I antigen A*0201 in healthy seropositive individuals. Since most HLA-A*02-positive Caucasians are HLA-A*0201-positive, it was hypothesized that HLA-A*02-positive individuals would be under-represented among Caucasians with EBV-associated HD. HLA-A*02 status was determined, using flow cytometry and/or the polymerase chain reaction, for 276 individuals including 176 cases of HD. There was no significant difference between the frequency of HLA-A*02 positivity in HD cases and controls, and between EBV-associated and non-associated cases of HD. The A*02 alleles of 14 cases of EBV-associated HD were further subtyped using nested PCR; all except one case were found to be A*0201-positive. We therefore investigated whether there was any evidence for mutation of the epitope representing amino acids 426-434 of LMP-2a which is restricted through HLA-A*0201. In 10/11 cases the nucleotide sequence encoding this epitope was identical to the published sequence; in the remaining case there was a mutation which would not be expected to alter the conformation of the epitope. Overall, our data suggest that other mechanisms of immune escape must be operative in EBV-associated HD.

Observations on memory B-cell development

We dissect in this article the roles of CD40 and its ligand in memory B-cell formation. Our data indicate that CD40 ligation does not directly lead to GC formation but it plays an indirect role related to maturation of helper T cells; signalling is bidirectional, to B cells, via CD40, upregulating cytokine receptor expression and to T cells, via CD40L, causing secretion of cytokines necessary for GC initiation. Later in the GC, CD40 selects mutated B cells for entry into the memory pool. This second T-cell-mediated CD40 ligation has consequences distinct from the first (rescue versus proliferation) that arise from rewiring of CD40 signal transduction pathways.

Inpatient deaths from acute myocardial infarction, 1982-92: analysis of data in the Nottingham heart attack register

OBJECTIVE

To assess longitudinal trends in admissions, management, and inpatient mortality from acute myocardial infarction over 10 years.

DESIGN

Retrospective analysis based on the Nottingham heart attack register.

SETTING

Two district general hospitals serving a defined urban and rural population.

SUBJECTS

All patients admitted with a confirmed acute myocardial infarction during 1982-4 and 1989-92 (excluding 1991, when data were not collected).

MAIN OUTCOME MEASURES

Numbers of patients, background characteristics, time from onset of symptoms to admission, ward of admission, treatment, and inpatient mortality.

RESULTS

Admissions with acute myocardial infarction increased from 719 cases in 1982 to 960 in 1992. The mean age increased from 62.1 years to 66.6 years (P < 0.001), the duration of stay fell from 8.7 days to 7.2 days (P < 0.001), and the proportion of patients aged 75 years and over admitted to a coronary care unit increased significantly from 29.1% to 61.2%. A higher proportion of patients were admitted to hospital within 6 hours of onset of their symptoms in 1989-92 than in 1982-4, but 15% were still admitted after the time window for thrombolysis. Use of beta blockers increased threefold between 1982 and 1992, aspirin was used in over 70% of patients after 1989, and thrombolytic use increased 1.3-fold between 1989 and 1992. Age and sex adjusted odds ratios for inpatient mortality remained unchanged over the study period.

CONCLUSIONS

Despite an increasing uptake of the "proved" treatments, inpatient mortality from myocardial infarction did not change between 1982 and 1992.

The use of tobacco, alcohol and other drugs by young Aboriginal people in Albany, Western Australia

This paper describes patterns of tobacco, alcohol and other drug use among Aboriginal people aged 8 to 17 years in the town of Albany, Western Australia. Of a total of 110 young Aboriginal people residing in the town at the time of the study, 105 were interviewed by two trained Aboriginal research assistants using interview schedules that included questions based on the national guidelines for the comparability of studies of drug use among young people. The most commonly used drugs were tobacco, alcohol and cannabis. Use of other substances was usually experimental, The majority (57 per cent) of this population had not used any drugs, 13 per cent made some use of alcohol and/or tobacco, 15 percent were polydrug users, and 15 per cent were frequent polydrug users. Use of drugs increased with age: 48 per cent of those aged 15 to 17 were frequent polydrug users. Tobacco consumption was greater and alcohol use less than that reported among Western Australian secondary school children of comparable age.

Laparoscopic versus open appendectomy: a prospective randomized trial of 81 patients

OBJECTIVE

To compare the efficacy of laparoscopic appendectomy (LA) and open appendectomy (OA) in the treatment of acute appendicitis.

DESIGN

A prospective randomized trial.

SETTING

A university teaching hospital.

PATIENTS

Eighty-one patients with a diagnosis of acute appendicitis were prospectively randomized to undergo either LA or OA. The two groups were matched for age and sex.

INTERVENTIONS

LA or OA.

MAIN OUTCOME MEASURES

Number of days in hospital and time to full recovery.

RESULTS

The mean hospital stay for LA was 3.23 days compared with 3.03 days for OA (p < 0.001). The mean number of narcotic injections required for patients in the LA group was 4.05 compared with 5.58 for patients in the OA group (p < 0.001). The mean time to complete recovery for patients in the LA group was 9.0 days compared with 16.2 days for patients in the OA group (p < 0.001). The mean operative time for LA was 73.8 minutes compared with 45.0 minutes for OA (p < 0.001). Three patients in the LA group had intra-abdominal abscesses (p > 0.25). No significant difference in wound infection rates was demonstrated (p > 0.05). Similarly, pain scores at 7 and 28 days showed no significant difference (p > 0.05).

CONCLUSIONS

With LA significantly fewer narcotic injections are required and there is a more rapid return to normal activities. LA takes longer to perform and was associated with three intra-abdominal abscesses. In cases of simple acute appendicitis the hospital stay for LA is significantly shorter.

Viral immunity: interferons jog old T-cell memories

The mechanism by which life-long immunity to viruses persists is a matter of some controversy. Interferons induced by subsequent unrelated viral infections may propagate existing memory T cells non-specifically.

Regulation of B cell growth and differentiation via CD21 and CD40

Stimulation in vitro of murine splenic B cells by lipopolysaccharide, anti-kappa Sepharose, anti-CD40 or allo-reactive T helper cells all up-regulated CD21 and CD23 surface expression. Neither anti-CD21 nor anti-CD23 antibodies induced B cell growth or differentiation when added in soluble form or coupled to Sepharose. However, anti-CD40-stimulated B cells showed increased proliferation in the presence of anti-CD21 antibodies coupled to Sepharose; co-stimulation via CD21 also induced differentiation to immunoglobulin secretion in a fraction of anti-CD40-stimulated B cells. Furthermore, anti-CD40 antibodies inhibited differentiation to immunoglobulin secretion induced by lipopolysaccharide and, hence, appears to be a dominant negative signal for B cell differentiation.

CD40-mediated regulation of interleukin-4 signaling pathways in B lymphocytes

The importance of cytokines in controlling immunoglobulin isotype switching is well known. Given the defect in switching to IgG, IgA and IgE isotypes in mice and humans that carry mutations in the CD40 and CD40 ligand genes, we have investigated the role of CD40 ligation in controlling B cell responses to interleukin (IL)-4. We have found that CD40-mediated signals cause a fivefold upregulation of IL-4 receptor (IL-4R) on the B cell surface and that this is associated with a 100-1000-fold increase in the cells' responsiveness to the cytokine. While we found no evidence of increased affinity or structural change of the receptor, we do find that prestimulation of B cells with anti-CD40 antibodies brings about several changes in the IL-4 signaling pathways. Subsequent delivery of IL-4 to CD40-prestimulated cells provokes intracellular signals distinct from those induced in resting B cells in response to IL-4. While resting B cells phosphorylate Jak3 kinase shortly after IL-4 activation, cells pre-incubated with anti-CD40 exhibit active dephosphorylation of this molecule and phosphorylation of proteins of around 45 kDa upon addition of IL-4. The common gamma chain, Jak3 and Jak1 can all be immunoprecipitated in normal amounts with the IL-4R chain after CD40 prestimulation. We show that the observed dephosphorylation of Jak3 may be due to a stable association with the src-homology protein tyrosine phosphatase SH-PTP2. In contrast, the enzyme appears to be inactive and to dissociate very quickly from the signaling complex in cells that are stimulated with IL-4 alone.

Immunological memory and protective immunity: understanding their relation

The immune system can remember, sometimes for a lifetime, the identity of a pathogen. Understanding how this is accomplished has fascinated immunologists and microbiologists for many years, but there is still considerable debate regarding the mechanisms by which long-term immunity is maintained. Some of the controversy stems from a failure to distinguish between effector and memory cells and to define their roles in conferring protection against disease. Here the current understanding of the cellular basis of immune memory is reviewed and the relative contributions made to protective immunity by memory and effector T and B cells are examined.

Somatic mutation of immunoglobulin V genes in vitro

The molecular mechanism behind affinity maturation is the introduction of point mutations in immunoglobulin (Ig) V genes, followed by the selective proliferation of B cells expressing mutants with increased affinity for antigen. An in vitro culture system was developed in which somatic hypermutation of Ig V genes was sustained in primed B cells. Cognate T cell help and cross-linking of the surface Ig were required, whereas the addition of lipopolysaccharide or a CD40 ligand to drive proliferation was insufficient. This system should facilitate understanding of the molecular and cellular mechanisms that regulate somatic mutation and B cell selection.

In vitro immunization of naive mouse B cells: establishment of IgM secreting hybridomas specific for souble protein or hapten from B cells cultured on CD40 ligand transfected mouse fibroblasts

CD40 has been shown to play an important role in the regulation of B cell survival, proliferation and Ig class switching. The natural partner for CD40 is CD40 ligand, gp 39, which is transiently expressed on activated T cells. In vitro, CD40 ligation leads to polyclonal B cell proliferation and, in the presence of appropriate cytokines, to the secretion of Ig of various isotypes. In the present study we show that naive B cells cultured in vitro on CD40L-transfected mouse fibroblasts in the presence of two different soluble antigens (beta-galactosidase and phenyloxazolone coupled to ovalbumin) can be specifically immunized as shown by direct single cell Elispot assays or after establishment of B cell hybridomas. However, under the conditions of in vitro immunization used, all hybridomas analysed produced specific IgM antibodies only and we failed to detect cells that had switched to other isotypes. The data suggests that CD40 ligation can be used for efficient in vitro immunization against soluble antigens for IgM production but that CD40 signals even in conjunction with cytokines are insufficient to induce high rate switching.

B cells solicit their own help from T cells

We have made use of T cell receptor (TCR)-transgenic mice with CD4+ T cells expressing a receptor specific for the self-antigen C5 (fifth component of complement) to study the role of different antigen-presenting cells in the determination of CD4+ T cell effector type. Contact of T cells from C5 TCR-transgenic mice with C5 protein or C5 peptide in vivo or in vitro induces biased T helper cell (Th) 1 type responses resulting in exclusive production of high levels of interferon gamma and interleukin (IL) 2. Transgenic mice, in contrast to nontransgenic littermates, do not generate an antibody response to C5. We show in this paper that B cell presentation in vitro induces a switch to the Th2 subset indicated by production of IL-4, and targetting C5 to B cells in vivo results in the generation of C5-specific antibodies.

Disaster plan education: how we made and tested a video

OBJECTIVE

To describe the making and testing of a 40 minute video to educate staff about a hospitals disaster plan.

METHODS

A disaster scene was created and 30 staff volunteers took part in the simulation of a major accident. The simulation was used to explain and demonstrate disaster triage. A multiple choice questionnaire was used to compare information recall in a group who had seen the video and a group who had read the written plan.

RESULTS

Large numbers of hospital staff voluntarily watched the video. The video group scored significantly higher than the reading group (P < 0.01), with mean scores of 72% and 45% respectively.

CONCLUSIONS

Videos have an impact lacking in written disaster plans and improve recall of emergency procedures.

CD40 ligand-transduced co-stimulation of T cells in the development of helper function

Mice that lack either CD40 (expressed on B cells) or CD40 ligand (expressed on activated T cells) are able neither to make IgG, IgA or IgE antibody responses, nor to generate germinal centres (the sites of formation of memory B cells). It has been assumed that these lesions were the result of an absence of signals to B cells through CD40. Here we show that the failure to signal T cells through CD40 ligand is an important contributory cause. Administration of soluble CD40 in vivo to CD40 knockout mice, restoring the missing signal through CD40 ligand initiates germinal centre formation. Furthermore, T cells primed in the absence of CD40 (in CD40 knockout mice) are unable to help normal B cells to class switch or to form germinal centres (GC). These results indicate that co-stimulation of T cells through CD40 ligand causes their differentiation into cells that help B cells to make mature antibody responses and to generate memory populations.

Evaluating government health and substance abuse programs for indigenous peoples: a comparative review

Most health and substance abuse programs for indigenous peoples in Australia are funded by government. Over the past decade there have been calls for greater accountability in the conduct of these programs. Initial attempts focused on the development of standardised performance indicators, an approach that has been criticised on both political and methodological grounds. Recently, some government agencies have sought to identify culturally appropriate models for the evaluation of programs for indigenous peoples. In a comparative review of the evaluation of indigenous programs in Australia and Canada, conducted for the Western Australian Aboriginal Affairs Department, the authors were not able to identify any generally applicable models. However, this literature review and our own research and experience in working with Aboriginal community organisations have identified some principles that should be an essential part of any attempts to evaluate health and substance abuse programs for indigenous peoples. Underlying these principles is the realisation that evaluation is not a politically or ideologically neutral activity. Theoretical and methodological considerations of the evaluation process must take into account the very real differences between the agendas of indigenous peoples and those who seek to evaluate programs for them.

How common is heart failure? Evidence from PACT (prescribing analysis and cost) data in Nottingham

BACKGROUND

The aim of the study was to determine the prevalence of heart failure in Nottinghamshire by an analysis of prescriptions for loop diuretics.

METHODS

An observational study was carried out in the Nottingham Health District, on the basis of Prescribing Analysis and Cost (PACT) data relating to nearly 400,000 kg of frusemide prescribed in the year 1991-1992 and general practitioner (GP) records on two groups of patients (total 903) prescribed frusemide.

RESULTS

The total amount of frusemide prescribed on a daily basis in Nottinghamshire in 1,048,566 mg. The mean daily dose of frusemide per patient is 60 mg and the median dose 40 mg. There are between 13,107 and 26,214 patients taking frusemide in Nottinghamshire. Fifty-six per cent of patients prescribed loop diuretics by their GP fulfil diagnostic criteria for heart failure.

CONCLUSION

The prevalence of heart failure in Nottinghamshire estimated from loop diuretic prescribing increases from 0.1 per cent in the age-group 30-39 years to 5.45 percent in patients aged over 90 years.

The effect of carrier and carrier priming on the kinetics and pattern of somatic mutation in the V chi Ox1 gene

Priming mice with a chicken gamma globulin (CGG) carrier protein significantly accelerated the onset of somatic mutation in the V chi Ox1 gene when the mice were subsequently immunized with 2-phenyl-5-oxazolone (phOx) coupled to CGG. The first mutations were already detected 7 days after immunization, while in the true primary response, they are not apparent until day 10. It was also found that comparing the mutation pattern of V chi Ox1 genes from hybridomas derived after immunization with phOx coupled to different carriers revealed quite distinct patterns of somatic mutation. Analysis of hybridoma sequences from the primary immune response to phOx-ovalbumin showed that the codons for Ser29, Ser31 and Lys45 were hot-spots for somatic mutation. Thus, the frequency and pattern of somatic mutations in the V chi Ox1 gene depends on the available T cell help as well as on the complex structure of the immunizing antigen.

Using telecommunication technology to manage children with diabetes: the Computer-Linked Outpatient Clinic (CLOC) Study

The purpose of this study was to evaluate the efficacy of using a telecommunication system to assist in the outpatient management of pediatric patients with insulin-dependent diabetes. Metabolic control, patients' psychosocial status, family functioning, perceived quality of life, patterns of parental/child responsibility for daily diabetes maintenance, and nursing time-on-task were evaluated. One hundred six pediatric patients (mean age = 13.3 years) were randomly assigned to an experimental or control outpatient clinic for 1 year. Experimental subjects transmitted self-monitoring blood glucose data by modem to the hospital every 2 weeks. Transmitted data were reviewed by nurse practitioners who telephoned subjects to discuss regimen adjustments. Control subjects received standard care with regimen adjustments made by physicians. There were no significant between-group differences for metabolic control, rates of hospitalization or emergency-room visits, psychological status, general family functioning, quality of life, or parent-child responsibility. A significant decrease was noted in nursing time-on-task for experimental subjects.