Monitoring to detect changes in water quality to meet policy objectives

Detecting change in water quality is key to providing evidence of progress towards meeting water quality objectives. A key measure for detecting change is statistical power. Here we calculate statistical power for all regularly (monthly) monitored streams in New Zealand to test the effectiveness of monitoring for policy that aims to decrease contaminant (phosphorus and nitrogen species, E. coli and visual clarity) concentrations to threshold levels in 5 or 20 years. While > 95% of all monitored sites had sufficient power and samples to detect change in nutrients and clarity over 20 years, on average, sampling frequency would have to double to detect changes in E. coli. Furthermore, to detect changes in 5 years, sampling for clarity, dissolved reactive phosphorus and E. coli would have to increase up to fivefold. The cost of sampling was predicted to increase 5.3 and 4.1 times for 5 and 20 years, respectively. A national model of statistical power was used to demonstrate that a similar number of samples (and cost) would be required for any new monitoring sites. Our work suggests that demonstrating the outcomes of implementing policy for water quality improvement may not occur without a step change in investment into monitoring systems. Emerging sampling technologies have potential to reduce the cost, but existing monitoring networks may also have to be rationalised to provide evidence that water quality is meeting objectives. Our study has important implications for investment decisions involving balancing the need for intensively sampled sites where changes in water quality occur rapidly versus other sites which provide long-term time series.

A Global Database of Soil Plant Available Phosphorus

Soil phosphorus drives food production that is needed to feed a growing global population. However, knowledge of plant available phosphorus stocks at a global scale is poor but needed to better match phosphorus fertiliser supply to crop demand. We collated, checked, converted, and filtered a database of c. 575,000 soil samples to c. 33,000 soil samples of soil Olsen phosphorus concentrations. These data represent the most up-to-date repository of freely available data for plant available phosphorus at a global scale. We used these data to derive a model (R² = 0.54) of topsoil Olsen phosphorus concentrations that when combined with data on bulk density predicted the distribution and global stock of soil Olsen phosphorus. We expect that these data can be used to not only show where plant available P should be boosted, but also where it can be drawn down to make more efficient use of fertiliser phosphorus and to minimise likely phosphorus loss and degradation of water quality.

1294 ASSESSMENT AND MANAGEMENT OF FRAILTY: A SURVEY OF HEALTHCARE PROFESSIONALS

Introduction

By 2030, it is estimated that 25% of Europeans will be aged over 65. [Dugarova; UN Development Programme; 2017] Frailty in this group is a key contributor to poorer outcomes. [Eamer; BMC Anesthesiology; 2017; 17:99] The term is common in healthcare but research into the issues faced by staff around assessment and management of frailty has been limited. We undertook a survey to identify challenges faced in providing care to those living with frailty and considered potential interventions.

Method

The survey was across three hospitals in our health board (which serves a population of around 390,000 with a range of services). [SBUHB;2022] It was developed iteratively through consultation in a multidisciplinary group and adapted questions from other similar validated surveys. [Eamer; BMC Anesthesiology; 2017; 17:99][Taylor; Future Healthcare Journal; 2017; 4(3):207-212].

Results

218 responses were received covering a variety of medical and surgical specialties. Participants showed a strong (80%) self-reported understanding of frailty as a clinical concept, but only 46% felt confident in their ability to assess patients for frailty. 74% stated they would benefit from more education on frailty. Other barriers included systemic challenges such as staffing and social care, but also a lack of understanding of frailty by patients and relatives which impacted shared decision-making.

Conclusions

The survey showed a significant demand for more education, especially awareness of pathways and assessment methods. It also highlighted the issue of patients’ (and relatives’) lack of understanding of frailty. In response, we are planning a targeted multi-disciplinary educational programme on frailty across the health board, as well as introducing patient information leaflets.

Casemix, management, and mortality of patients rreseceiving emergency neurosurgery for traumatic brain injury in the Global Neurotrauma Outcomes Study: a prospective observational cohort study

BACKGROUND

Traumatic brain injury (TBI) is increasingly recognised as being responsible for a substantial proportion of the global burden of disease. Neurosurgical interventions are an important aspect of care for patients with TBI, but there is little epidemiological data available on this patient population. We aimed to characterise differences in casemix, management, and mortality of patients receiving emergency neurosurgery for TBI across different levels of human development.

METHODS

We did a prospective observational cohort study of consecutive patients with TBI undergoing emergency neurosurgery, in a convenience sample of hospitals identified by open invitation, through international and regional scientific societies and meetings, individual contacts, and social media. Patients receiving emergency neurosurgery for TBI in each hospital's 30-day study period were all eligible for inclusion, with the exception of patients undergoing insertion of an intracranial pressure monitor only, ventriculostomy placement only, or a procedure for drainage of a chronic subdural haematoma. The primary outcome was mortality at 14 days postoperatively (or last point of observation if the patient was discharged before this time point). Countries were stratified according to their Human Development Index (HDI)-a composite of life expectancy, education, and income measures-into very high HDI, high HDI, medium HDI, and low HDI tiers. Mixed effects logistic regression was used to examine the effect of HDI on mortality while accounting for and quantifying between-hospital and between-country variation.

FINDINGS

Our study included 1635 records from 159 hospitals in 57 countries, collected between Nov 1, 2018, and Jan 31, 2020. 328 (20%) records were from countries in the very high HDI tier, 539 (33%) from countries in the high HDI tier, 614 (38%) from countries in the medium HDI tier, and 154 (9%) from countries in the low HDI tier. The median age was 35 years (IQR 24-51), with the oldest patients in the very high HDI tier (median 54 years, IQR 34-69) and the youngest in the low HDI tier (median 28 years, IQR 20-38). The most common procedures were elevation of a depressed skull fracture in the low HDI tier (69 [45%]), evacuation of a supratentorial extradural haematoma in the medium HDI tier (189 [31%]) and high HDI tier (173 [32%]), and evacuation of a supratentorial acute subdural haematoma in the very high HDI tier (155 [47%]). Median time from injury to surgery was 13 h (IQR 6-32). Overall mortality was 18% (299 of 1635). After adjustment for casemix, the odds of mortality were greater in the medium HDI tier (odds ratio [OR] 2·84, 95% CI 1·55-5·2) and high HDI tier (2·26, 1·23-4·15), but not the low HDI tier (1·66, 0·61-4·46), relative to the very high HDI tier. There was significant between-hospital variation in mortality (median OR 2·04, 95% CI 1·17-2·49).

INTERPRETATION

Patients receiving emergency neurosurgery for TBI differed considerably in their admission characteristics and management across human development settings. Level of human development was associated with mortality. Substantial opportunities to improve care globally were identified, including reducing delays to surgery. Between-hospital variation in mortality suggests changes at an institutional level could influence outcome and comparative effectiveness research could identify best practices.

FUNDING

National Institute for Health Research Global Health Research Group.

O8: DIRECT MANIPULATION OF THE INTESTINAL MICROBIOME TO INFLUENCE POST-OPERATIVE OUTCOMES

Introduction

Distal feeding (DF) involves intubation of the distal limb of a loop ileostomy to feed with a prebiotic mix. Studies suggest that distally feeding patients following anterior resection prior to ileostomy closure may be beneficial as a form of bowel pre-habilitation. These pilot data examine the adaptive immune response to DF.

Method

Ten healthy controls with an intact GI tract were compared with 10 patients following rectal cancer resection and chemo/radiotherapy, prior to closure of ileostomy over 8 weeks of DF. We examined B and T cell memory responses from peripheral blood using cell proliferation assays. Cells were cultured with dead antigen to reflect the microbiota in the small and large bowel. Two negative and two positive controls were used to assess minimal and maximum cell proliferation.

Result

B cell responses prior to DF were increased in the defunctioned group compared to the normal controls to significance (p=0.0014). After 8 weeks of DF the groups were comparable. T cell responses to bacteria had significant differences in proliferation rate following DF commencement, CD4 week 0 vs 3 p=0.0001, week 3 vs 8 p=0.000034, CD8 week 0 vs 3 p=0.0001, week 3-8 p=0.00024). In individual patients, CD4 responses were shown to shift from responses to facultative aerobic species, to strict anaerobes.

Conclusion

These data suggest that distal feeding fundamentally resets peripheral circulating memory and it may be of use in pre-habilitating the bowel prior to restoration of continuity. Early clinical data suggests that distal feeding improves post-operative outcomes.

Take-home message

distal feeding is an easy pre-operative intervention that has a significant effect on cell proliferation and antigen response, which may contribute to improved post operative outcomes.

Global mapping of freshwater nutrient enrichment and periphyton growth potential

Periphyton (viz. algal) growth in many freshwater systems is associated with severe eutrophication that can impair productive and recreational use of water by billions of people. However, there has been limited analysis of periphyton growth at a global level. To predict where nutrient over-enrichment and undesirable periphyton growth occurs, we combined several databases to model and map global dissolved and total nitrogen (N) and phosphorus (P) concentrations, climatic and catchment characteristics for up to 1406 larger rivers that were analysed between 1990 and 2016. We predict that 31% of the global landmass contained catchments may exhibit undesirable levels of periphyton growth. Almost three-quarters (76%) of undesirable periphyton growth was caused by P-enrichment and mapped to catchments dominated by agricultural land in North and South America and Europe containing 1.7B people. In contrast, undesirable periphyton growth due to N-enrichment was mapped to parts of North Africa and parts of the Middle East and India affecting 280 M people. The findings of this global modelling approach can be used by landowners and policy makers to better target investment and actions at finer spatial scales to remediate poor water quality owing to periphyton growth.

Liquid Chromatographic Determination of Glyphosate in Water-Soluble Granular Formulations: Collaborative Study

A liquid chromatographic (LC) method for the determination of glyphosate in various water-soluble granular formulations was tested by 28 laboratories. Samples were dissolved in mobile phase and injected directly into an LC system with a 25 cm SAX column and a mobile phase of 96% aqueous buffer solution, 0.0062M KH2PO4, and 4% methanol. Detection was by UV absorption at 195 nm. Manual or automated injections were made via fixed-volume loops. Calculations were based on peak area comparisons with external standards. The collaborative study analyzed 5 matched pairs of 4 water-soluble granular formulations, with one determination per sample. The study generated 138 matched pairs, which were analyzed by using the AOAC spreadsheet and Youden’s matched-pair calculations. Coefficients of variation for the 4 formulations ranged from 0.65 to 1.37%. The LC method for the determination of glyphosate in water-soluble granular formulations has been adopted first action by AOAC INTERNATIONAL.

Innovations in Practice: Evaluating clinical outcome and service utilization in an AMBIT-trained Tier 4 child and adolescent mental health service

BACKGROUND

To present clinical outcome data of the Adolescent Mentalization-based Integrative Treatment (AMBIT)-trained NHS Lothian Tier 4 child and adolescent mental health service in the context of service utilization and engagement.

METHOD

Data were obtained for a 2-year period that included details of all face-to-face contacts between young people and clinicians along with routinely collected clinical outcomes data relating to anxiety, depression, symptoms of psychosis and quality of life.

RESULTS

Improvements were observed in quality of life, symptoms and distress across the course of the intervention. Overall attendance rates were high (80%). Relative to those who were better engaged, the less well-engaged group received the same number of appointments but spent longer in the service (χ² (1) = 5.26, p = .022), had more professionals involved in their care (χ² (1) = 4.91, p = .027) and showed a nonsignificant trend to more inpatient admissions. Later engagement was not associated with distress or symptoms at entry into the service with the exception of negative symptoms in the Early Psychosis Support Service cohort. Age and two quality of life factors were associated with later engagement (p < .05).

CONCLUSIONS

Our AMBIT-trained Tier 4 CAMH service demonstrates change over the course of intervention consistent with the service model's theoretical expectations. Engagement with the service may be associated more with factors related to social circumstance and functioning than with key symptoms and distress. Less well-engaged young people utilize increased service resource. AMBIT's mentalizing focus may improve service provision for young people who are poorly engaged with mental health services.

Towards Attosecond High-Energy Electron Bunches: Controlling Self-Injection in Laser-Wakefield Accelerators Through Plasma-Density Modulation

Self-injection in a laser-plasma wakefield accelerator is usually achieved by increasing the laser intensity until the threshold for injection is exceeded. Alternatively, the velocity of the bubble accelerating structure can be controlled using plasma density ramps, reducing the electron velocity required for injection. We present a model describing self-injection in the short-bunch regime for arbitrary changes in the plasma density. We derive the threshold condition for injection due to a plasma density gradient, which is confirmed using particle-in-cell simulations that demonstrate injection of subfemtosecond bunches. It is shown that the bunch charge, bunch length, and separation of bunches in a bunch train can be controlled by tailoring the plasma density profile.

Follicular helper T cells are responsible for IgE responses to Der p 1 following house dust mite sensitization in mice

BACKGROUND

Th2 cells have long been considered responsible for the switching of B cells to production of IgE during cognate interaction, primarily due to their expression of CD40L and secretion of IL-4. This concept has been challenged by the more recent definition of follicular helper T cells (Tfh) as the key T cell subset in B cell isotype switching, due to their physical location at the boundary of T cell:B cell areas in lymphoid follicles and ability to express IL-4 and CD40L.

OBJECTIVE

To determine whether Tfh cells are responsible for IgE responses to Der p 1 allergen after house dust mite (HDM)-induced allergic sensitization.

METHODS

Mice deficient in Tfh cells were sensitized to HDM and Der p 1-specific IgE measured by ELISA.

RESULTS

Mice with a mutation in T cell-expressed IL-6R were unable to expand Tfh populations after HDM sensitization, and their anti-Der p 1 IgE, IgG1 and total IgE responses were reduced by 80-90% compared with wild-type mice. These animals displayed unaltered lung Th2 and eosinophilic responses after intranasal HDM challenge and normal IL-4 production, but B cell infiltration of the airways was abrogated.

CONCLUSIONS AND CLINICAL RELEVANCE

Our data indicate that Tfh cells are largely responsible for switching B cells to IgE synthesis, most likely via an IgG1(+) intermediate. However, Th2 cells are the major source of IL-4 during HDM sensitization and this might contribute to IgE synthesis at a stage distal to Tfh-mediated isotype switching. The IL-6/follicular helper T cell pathway is a potential therapeutic target in allergic disease.

Validation of the sperm chromatin dispersion (SCD) test in the amphibian Xenopus laevis using in situ nick translation and comet assay

The integrity of sperm DNA is becoming increasingly recognised as an important parameter of semen quality, but there are no published reports of this procedure for any amphibian. The primary aim of this study was to apply a modified sperm chromatin dispersion (SCD) test (Halomax) to an amphibian sperm model (African clawed frog; Xenopus laevis) and to validate the assay against in situ nick translation (ISNT) and the double-comet assay procedure. Inactivated spermatozoa were collected from fresh testes (n = 3). Sperm DNA fragmentation (SDF) for each sperm sample was conducted immediately following activation (T0) and again after 1 h (T1) and 24 h (T24) of incubation at room temperature in order to produce a range of spermatozoa with differing levels of DNA damage. The SCD procedure resulted in the production of three nuclear morphotypes; amphibian sperm morphotype 1 (ASM-1) and ASM-2 showed no evidence of DNA damage, whereas ASM-3 spermatozoa were highly fragmented with large halos of dispersed DNA fragments and a reduced nuclear core. ISNT confirmed that ASM-3 nuclei contained damaged DNA. There was a significant correlation (r = 0.9613) between the levels of ASM-3 detected by the SCD test and SDF revealed by the double-comet assay.

Patient Reported Experience Measures (PREMs) in chronic heart failure

BACKGROUND

Patient Reported Experience Measures (PREMs) is an essential tool for assessing the quality of chronic disease management. The optimal method for delivering a PREMs survey however is unknown. This study reports two methods for assessing PREMs in patients with chronic heart failure (CHF).

METHODS

A bespoke online and postal survey delivered to community-based CHF patients in Scotland.

RESULTS

A total of 121 patients (73 postal and 48 online) completed the survey. The online cohort were younger, had less contact with a CHF nurse, were more likely to see a CHF doctor and seemed less satisfied with the quality of clinical services. The postal cohort returned fewer negative comments (20 [27.4%] vs 28 [58.3%]; p<0.0001). Several recurring themes were identified.

CONCLUSIONS

There are differences in participation rates and responses between postal and online surveys; the accuracy of the feedback gathered using these methods is therefore difficult to determine. Clinicians should consider offering a range of options to enable patients to reflect and 'voice' their opinions regarding clinical services.

Can an epilepsy nurse specialist-led self-management intervention reduce attendance at emergency departments and promote well-being for people with severe epilepsy? A non-randomised trial with a nested qualitative phase

Objectives

To (1) describe the characteristics and service use of people with established epilepsy (PWE) who attend the emergency department (ED); (2) evaluate the economic impact of PWE who attend the ED; (3) determine the effectiveness and cost-effectiveness of an epilepsy nurse specialist (ENS)-led self-management intervention plus treatment as usual (TAU) compared with TAU alone in reducing ED use and promoting well-being; (4) describe patients' views of the intervention; and (5) explore their reasons for attending the ED.

Design

Non-randomised trial with nested qualitative study.

Setting

The EDs of three inner London hospitals. The EDs each offer similar services and support a similar local population, which made a comparison of patient outcomes reasonable.

Participants

Adults diagnosed with epilepsy for ≥ 1 year were prospectively identified from the EDs by presenting symptom/discharge diagnosis. We recruited 85 of 315 patients with 44 forming the intervention group and 41 the comparison group.

Intervention

Intervention participants were offered two one-to-one outpatient sessions delivered by an ENS who aimed to optimise self-management skills and knowledge of appropriate emergency service use. The first session lasted for 45–60 minutes and the second for 30 minutes.

Main outcome measures

The primary outcome was the number of ED visits that participants reported making over the 6 months preceding the 12-month follow-up. Secondary outcomes were visits reported at the 6-month follow-up and scores on psychosocial measures.

Results

In the year preceding recruitment, the 85 participants together made 270 ED visits. The frequency of their visits was positively skewed, with 61% having attended multiple times. The mean number of visits per participant was 3.1 [standard deviation (SD) 3.6] and the median was two (interquartile range 1–4). Mean patient service cost was £2355 (SD £2455). Compared with findings in the general epilepsy population, participants experienced more seizures and had greater anxiety, lower epilepsy knowledge and greater perceived stigma. Their outpatient care was, however, consistent with National Institute for Health and Clinical Excellence recommendations. In total, 81% of participants were retained at the 6- and 12-month follow-ups, and 80% of participants offered the intervention attended. Using intention-to-treat analyses, including those adjusted for baseline differences, we found no significant effect of the intervention on ED use at the 6-month follow-up [adjusted incidence rate ratio (IRR) 1.75, 95% confidence interval (CI) 0.93 to 3.28] or the 12-month follow-up (adjusted IRR 1.92, 95% CI 0.68 to 5.41), nor on any psychosocial outcomes. Because they spent less time as inpatients, however, the average service cost of intervention participants over follow-up was less than that of TAU participants (adjusted difference £558, 95% CI –£2409 to £648). Lower confidence in managing epilepsy and more felt stigma at baseline best predicted more ED visits over follow-up. Interviews revealed that patients generally attended because they had no family, friend or colleague nearby who had the confidence to manage a seizure. Most participants receiving the intervention valued it, including being given information on epilepsy and an opportunity to talk about their feelings. Those reporting most ED use at baseline perceived the most benefit.

Conclusions

At baseline, > 60% of participants who had attended an ED in the previous year had reattended in the same year. In total, 50% of their health service costs were accounted for by ED use and admissions. Low confidence in their ability to manage their epilepsy and a greater sense of stigma predicted frequent attendance. The intervention did not lead to a reduction in ED use but did not cost more, partly because those receiving the intervention had shorter average hospital stays. The most common reason reported by PWE for attending an ED was the lack of someone nearby with sufficient experience of managing a seizure. Those who attended an ED frequently and received the intervention were more likely to report that the intervention helped them. Our findings on predictors of ED use clarify what causes ED use and suggest that future interventions might focus more on patients' perceptions of stigma and on their confidence in managing epilepsy. If addressed, ED visits might be reduced and efficiency savings generated.

Trial registration

Current Controlled Trials ISRCTN06469947.

Funding

This project was funded by the NIHR Health Services and Delivery Research programme and will be published in full inHealth Services and Delivery Research; Vol. 1, No. 9. See the HSDR programme website for further project information.

The biology of platelet-rich plasma and its application in trauma and orthopaedic surgery: a review of the literature

Although mechanical stabilisation has been a hallmark of orthopaedic surgical management, orthobiologics are now playing an increasing role. Platelet-rich plasma (PRP) is a volume of plasma fraction of autologous blood having platelet concentrations above baseline. The platelet alpha granules are rich in growth factors that play an essential role in tissue healing, such as transforming growth factor-beta, vascular endothelial growth factor, and platelet-derived growth factor. PRP is used in various surgical fields to enhance bone and soft-tissue healing by placing supraphysiological concentrations of autologous platelets at the site of tissue damage. The easily obtainable PRP and its possible beneficial outcome hold promise for new regenerative treatment approaches. The aim of this literature review was to describe the bioactivities of PRP, to elucidate the different techniques for PRP preparation, to review animal and human studies, to evaluate the evidence regarding the use of PRP in trauma and orthopaedic surgery, to clarify risks, and to provide guidance for future research.

Association between human cases and poultry outbreaks of highly pathogenic avian influenza in Vietnam from 2003 to 2007: a nationwide study

This study quantifies the spatio-temporal association between outbreaks of highly pathogenic avian influenza H5N1 in domestic poultry (n = 3050) and human cases (n = 99) in Vietnam during 2003-2007, using rare events logistic regression. After adjusting for the effect of known confounders, the odds of a human case being reported to authorities increased by a factor of 6.17 [95% confidence interval (CI) 3.33-11.38] and 2.48 (95% CI 1.20 - 5.13) if poultry outbreaks were reported in the same district 1 week and 4 weeks later respectively. When jointly considering poultry outbreaks in the same and neighbouring districts, occurrence of poultry outbreaks in the same week, 1-week later, and 4 weeks later increased the odds of a human case by a factor of 2.75 (95% CI 1.43-5.30), 2.56 (95% CI 1.31-5.00) and 2.70 (95% CI 1.56-4.66) respectively. Our study found evidence of different levels of association between human cases and poultry outbreaks in the North and the South of the country. When considering the 9-week interval extending from 4 weeks before to 4 weeks after the week of reporting a human case, in the South poultry outbreaks were recorded in 58% of cases in the same district and 83% of cases in either the same or neighbouring districts, whereas in the North the equivalent results were only 23% and 42%. The strength of the association between human and poultry cases declined over the study period. We conclude that owner reporting of clinical disease in poultry needs to be enhanced by targeted agent-specific surveillance integrated with preventive and other measures, if human exposure is to be minimized.

Blockade of chronic graft-versus-host disease by alloantigen-induced CD4+CD25+Foxp3+ regulatory T cells in nonlymphopenic hosts

CD4(+)CD25(+) regulatory T cells (Tregs) are well known to suppress immunopathology induced in lymphopenic animals following T cell reconstitution, including acute graft-versus-host disease (GVHD) post-bone marrow transplantation. The regulatory potential of this subset in nonlymphopenic hosts and in chronic, Th2-mediated GVHD is less clear. We have generated alloantigen-specific cells from CD4(+)CD25(+) populations stimulated with MHC-disparate dendritic cells and found them to express a stable Treg forkhead box p3(+) phenotype with enhanced suppressive activity mediated by cell contact. When transferred into nonlymphopenic F1 hosts, nonspecific Tregs proliferated as rapidly as CD4(+)CD25(-) cells but displayed distinct growth kinetics in vitro. Tregs, expanded in response to alloantigen in vitro, displayed greatly enhanced suppressive activity, which was partially antigen-specific. They were effective inhibitors of chronic GVHD, blocking donor cell engraftment, splenomegaly, autoantibody production, and glomerulonephritis. CD25(+) and CD25(-) cells were equally susceptible to inhibition by immunosuppressive drugs targeting TCR signaling and rapamycin, but Tregs were resistant to inhibition by dexamethasone. The data indicate that alloantigen-driven expansion, rather than homeostatic proliferation, is key to the effectiveness of CD4(+)CD25(+) Tregs in GVHD and suggest that cellular therapy with alloantigen-induced Tregs in combination with glucocorticoid treatment would be effective in prevention of chronic GVHD after immune reconstitution.

Additional nucleoli and NOR activity during meiotic prophase I in larch (Larix decidua Mill.)

Transcriptional activity was investigated in successive stages of prophase I (male meiosis) of larch meiocytes. Br-UTP incorporated into RNA was detected by light and electron microscopy. Two peaks of RNA synthesis were identified in the nucleolus. The first occurred during the zygotene-pachytene stage and the second (not previously described in plant meiocytes) in the diplotene. These processes correlated with a considerable increase in nucleolus volume during these periods. At the end of the zygotene, several perinucleolar structures lying close to each other and containing rRNA, argyrophilic proteins, U3 small nucleolar RNA, and fibrillarin were observed. The occurrence of newly formed RNA was also observed in these structures. This suggests that the observed perinucleolar structures correspond to the additional nucleoli known from animals.

Preferences for aspects of a dermatology consultation

BACKGROUND

General practitioners with special interests (GPSIs) are increasingly being used to provide dermatology services in the U.K. Little is known about U.K. dermatology patient attitudes to proposed variations in secondary care service delivery or the values they attach to aspects of the care they receive.

OBJECTIVES

To quantify preferences for different attributes of care within dermatology secondary care services.

METHODS

Attributes of care that are important to dermatology patients were derived using in-depth qualitative interviews with 19 patients at different points in the care pathway. A discrete choice experiment using 'best-worst scaling' was sent by post to 119 patients referred to secondary care dermatology services and suitable for GPSI care who had agreed to participate in research.

RESULTS

Four attributes were derived from the qualitative work: waiting, expertise, thorough care and convenience. For the discrete choice experiment, 99 patients returned questionnaires, 93 of which contained sufficient data for analysis. All attributes were found to be quantitatively important. The attribute of greatest importance was expertise of the doctor, while waiting time was of least importance. Respondents were willing to wait longer than the current 3 months maximum to receive care that was thorough, 2.1 months to see a team led by an expert and 1.3 months to attend a consultation that is easy to get to.

CONCLUSIONS

Although the need to reduce outpatient waiting times is a key policy driver behind the expansion of GPSI services, this does not appear to be the most important issue for patients. The thoroughness with which the consultation is provided and the expertise of the clinician seen are higher priorities.

Preterm delivery risk in relation to maternal HIV infection, history of malaria and other infections among urban Zimbabwean women

OBJECTIVE

To examine preterm delivery risk in relation to maternal HIV infection, malaria history, and other infections among Zimbabwean women.

DESIGN

Hospital based, cross sectional study.

SETTING

Harare Maternity Hospital, Harare, Zimbabwe.

SUBJECTS

A convenient sample of 500 pregnant women.

MAIN OUTCOME MEASURE

Preterm delivery. THE STUDY FACTORS: Maternal socio-demographic information, and infectious disease history (during the year before pregnancy).

METHOD

Between July 1998 and March 1999 data were collected for a cross sectional study of pregnant women who delivered at the Harare Maternal Hospital. The association of maternal HIV infection, history of malaria, and other infections with preterm delivery were determined using multivariate analysis.

RESULTS

Overall, 497 women were studied, 444 (89.3%) delivered at term and 53 women (10.7%) delivered preterm. Women who delivered preterm were less likely to be HIV seropositive compared with others (odds ratio [OR] = 0.75. 95% confidence interval (CI): 0.38 to 21.48). Preterm delivery was associated with having tuberculosis infections in the year prior to the pregnancy (OR = 10.15, 95% CI: 1.15 to 89.87). Other infections associated with preterm delivery were malaria (OR = 2.39, 95% CI: 1.07 to 5.31), chest infections (OR = 2.63, 95% CI: 0.76 to 9.17), and Herpes (shingles) infection (OR = 2.58, 95% CI: 0.56 to 11.85). Overall, a positive history of any of the non-sexually transmitted infections (in aggregate) was associated with a 3.20 fold increase risk for preterm delivery (OR = 3.20. 95% CI: 1.59 to 6.43). Women with a history of infection and who did not use iron supplements during pregnancy, compared with women without such an history and who used iron supplements, experienced the highest risk for preterm delivery (OR = 8.34, 95% CI: 3.30 to 21.07).

CONCLUSION

Maternal non-STD infections, (i.e., tuberculosis, malaria, and chest infections) occurring in the year prior to pregnancy were associated with an increased risk of preterm delivery. The association of non-sexually transmitted infections and preterm delivery was particularly strong among women who did not use iron supplements during pregnancy.

Resolution of allergic airways inflammation but persistence of airway smooth muscle proliferation after repeated allergen exposures

BACKGROUND

Chronic inflammation in asthmatic airways can lead to characteristic airway smooth muscle (ASM) thickening and pathological changes within the airway wall.

OBJECTIVE

We investigated the long-term effects of repeated allergen exposure.

METHODS

Brown-Norway (BN) rats sensitized to ovalbumin (OVA) were exposed to OVA or saline aerosol every third day on six occasions and studied 24 h, 7 days and 35 days after the final exposure. We measured airway inflammation, ASM cell proliferation (by incorporation of bromodeoxyuridine; BrdU) and bronchial responsiveness to acetylcholine.

RESULTS

At 24 h, in OVA-exposed rats, we detected elevated OVA-specific serum IgE, increased numbers of macrophages, eosinophils, lymphocytes and neutrophils in the bronchoalveolar lavage (BAL) fluid and increased numbers of MBP+ (major basic protein) eosinophils and CD2+ T cells within the bronchial submucosa. This coincided with increased numbers of ASM cells expressing BrdU and with bronchial hyper-responsiveness (BHR). At 7 days, BHR was detected in OVA-exposed rats, coincident with increased numbers of macrophages and lymphocytes in BAL fluid together with increased numbers of CD2+ T cells within the bronchial submucosa. This coincided with increased numbers of ASM cells expressing BrdU. By day 35, the number of ASM cells expressing BrdU remained elevated in the absence of cellular infiltration and BHR.

CONCLUSION

Repeated OVA-challenge results in persistent ASM cell proliferation in the absence of bronchial inflammation and BHR, which lasts for at least 1 week following cessation of exposure.

Activation-induced cell death of human T-cell subsets is mediated by Fas and granzyme B but is independent of TNF-alpha

Human primary effector T cells were analyzed for their susceptibility to anti-CD3-induced activation-induced cell death (AICD). Th1 and Tc1 cells were more susceptible to AICD than their type 2 counterparts. Type 1 and type 2 subsets were also found to be differentially susceptible to CD95-mediated apoptosis, although cell-surface expression of CD95 and CD95L was at similar levels on all subsets. A role for CD95 in AICD was confirmed by the addition of anti-CD95L antibodies that partially abrogated AICD. Residual apoptosis could not be accounted for by TNF-alpha/TNFR interactions because although type 1 cells secreted more TNF-alpha than type 2 cells, the addition of TNFR:Fc fusion protein did not inhibit AICD. Instead, a reduction in AICD was observed in the presence of EGTA or concanamycin A. The inhibition of apoptosis by a granzyme B inhibitor z-AAD-CMK in Tc1 cells further indicated an involvement of the granule exocytosis mechanism in AICD.

Early Th1/Th2 cell polarization in the absence of IL-4 and IL-12: T cell receptor signaling regulates the response to cytokines in CD4 and CD8 T cells

Differentiation of developing T cells into the type 1 (IFN-gamma-producing) or type 2 (IL-4-producing) subsets is a central theme of immune regulation. The balance of IL-4 and IL-12 present during T cell activation has been considered the major influence on type 1 versus type 2 development. Here we show that CD4 T cells can become biased towards type 1 or type 2 phenotypes during their initial activation in the absence of IL-4 or IL-12. This type of regulation is dependent on the balance of MAPkinase, protein kinase C, and calcineurin signaling after TCR engagement. Later maturation of Th1 or Th2 effectors is dependent on IL-12 or IL-4. However Tc1 CD8 effector development is independent of IL-12, and Tc2 cell generation requires both appropriate TCR signals and IL-4 early in effector development. Using an altered peptide ligand to stimulate TCR transgenic T cells, we show that altered signaling regulates the numbers of CD8 cells capable of developing into Tc2 effectors, and also their responsiveness to IL-4. Together, the results support a two-stage model of differentiation in which intermediate cells biased towards the type 1 or type 2 pathways after activation, are subsequently matured in response to IL-12 or IL-4, respectively.

[Frequency of gastric lymphoma at 6 hospitals in Mexico City]

BACKGROUND

Gastric lymphoma has been traditionally considered a rare neoplasm that constitutes 1-5% of malignant gastric tumors. Two studies performed in Mexico in 1960 and 1966 found that only 1.9% and 1% of gastric neoplasms were lymphomas. Nevertheless, some studies made in the U.S. and in some European countries in recept decades have revealed an increase in the frequency of this neoplasm. A recent study made at two National Health Institutes in Mexico City (Instituto Nacional de Cancerología and Instituto Nacional de la Nutrición) revealed a remarkable increase in the frequency of gastric lymphoma (9.3% and 10.3%, respectively) in recent years.

AIM

To define whether there is an actual increase of lymphoma in our population and whether it includes other hospitals in Mexico City that provides attention to populations different from those who attend referral centers.

MATERIALS AND METHODS

Six hospitals in Mexico City were selected, including two National Health Institutes (Instituto Nacional de la Nutrición and Instituto Nacional de Cancerología), two private general hospitals used by patient with a high socioeconomic level (Hospital Español and Hospital Inglés), and two public general hospitals frequented by low-income patients (hospital Juárez and Hospital General de México). In each case, the gastric lymphomas diagnosed in each participant hospitals in the last 5 years were registered. For comparative purpose, diagnosed cases of gastric adenocarcinoma during the same period were also registered. Other types of gastric neoplasms were excluded from the study because they formed a very heterogeneous group and represented a minimal proportion of malignant gastric tumors. Age and sex of each patient were included for all lymphomas.

RESULTS

A total of 879 malignant gastric neoplasms were included in our study. The relative percentage for gastric lymphoma by institution in descendent order was Hospital Español 25.4%; Instituto Nacional de la Nutrición 13.7%, Hospital Inglés 11.5%, Hospital General de México 8.5%, Instituto Nacional de Cancerología 6%, and Hospital Juárez 6%. Mean general frequency taking into account the six hospitals was 9.1%.

CONCLUSIONS

Frequency of gastric lymphomas in all analyzed institutions was higher than that reported in most series in the medical literature (1-5%) and that reported for the Mexican population in 1960 and 1966. The increase was most remarkable in hospitals attended by patients with high incomes (Hospital Español, Hospital Inglés), although the total number of neoplasms reported by these institutions was smaller than that reported by hospitals were by patients with lower incomes (Hospital Juárez, Instituto Nacional de Cancerología). The reason for this increase is unknown, but one might speculate that some strains of Helicobacter pylori, nutritional factors, and ethnic differences could be involved. Both gastroenterologists and pathologists must recognize the increase of this neoplasm because unlike gastric adenocarcinoma, gastric lymphoma is a curable disease in a high percentage of cases.

Different forms of heroin and their relationship to cook-up techniques: data on, and explanation of, use of lemon juice and other acids

Recent reports of the use of lemon juice in the preparation of heroin for injection have failed to recognize the importance of the different forms of heroin (in the form of the salt or the base) and the impact of this on the chemical manipulation required before injection. One hundred and four opiate addicts in London were interviewed about the forms of heroin (white, brown, etc) and their relationship to cook-up techniques (use of heat and acid). White heroin was typically prepared with water and heat; brown heroin was prepared with acid (citric acid or Vitamin C (ascorbic acid) or lemon juice) and heat; pharmaceutical heroin was prepared with water only (i.e. neither acid nor heat). On the last occasion of heroin use, brown heroin had been the form most commonly used, with over 90% of the sample using citric acid or vitamin C. Lemon juice was rarely used, and heat was almost universally applied in conjunction with lemon juice.

T cytotoxic 1 and T cytotoxic 2 CD8 T cells both inhibit IgE responses

BACKGROUND

It is well recognized that CD8 T cells inhibit IgE responses. In this study, we investigated the mechanism of CD8 T cell-mediated IgE suppression by comparing the capacity of T cytotoxic 1 (Tc1) and T cytotoxic 2 (Tc2) CD8 T cells to inhibit IgE responses to ovalbumin (OVA).

METHODS

Tc1 and Tc2 CD8 T cells were generated from OVA(257-264)-specific Vbeta5.2 T cell receptor (TcR) transgenic mice by stimulation with anti-CD3 and anti-CD28 under Tc1 and Tc2 polarizing conditions. Tc1 and Tc2 Vbeta5.2 TcR CD8 T cells (10(6)) were adoptively transferred to syngeneic mice, and following immunization with 100 micro of OVA/alum, serum IgE antibodies were measured by passive cutaneous anaphylaxis and expressed as the highest dilution that gave a detectable skin response.

RESULTS

Both Tc1 and Tc2 CD8 T cells from OT-I mice inhibited IgE.

CONCLUSION

Both Tc1 and Tc2 CD8 T cells promote Th1 immunity and inhibit IgE responses. This process appears to be independent of CD8 T cell-derived IFN-gamma, as both Tc2 (IFN-gamma-) and Tc1 (IFN-gamma+) CD8 T cells inhibited IgE.