A systematic review and meta-analysis of human population studies on the association between exposure to toxic environmental chemicals and left ventricular dysfunction (LVD)

BACKGROUND

Exposure to environmental chemicals has been associated with an elevated risk of heart failure (HF). However, the impact on early markers of HF, such as left ventricular dysfunction (LVD), remains limited.

OBJECTIVE

To establish a foundation of evidence regarding early HF markers and their association with environmental pollutants, a systematic review and meta-analysis was conducted.

METHODS

The search, conducted on October 13th, 2023, encompassed PubMed, Embase, and Web of Science without filters, focusing on observational studies reporting myocardial geometrical, structural, or functional alterations in individuals without a history of heart disease. This included the general adult population, workers, young people, and the elderly. The risk of bias was assessed using the ROBINS-I tool at both study and item levels.

RESULTS

The systematic review included 17 studies involving 43.358 individuals exposed to air pollution and 2038 exposed to heavy metals. Approximately 41% of the effect measures of associations reported significant abnormalities in myocardial structure or function. The metanalyses by pollutants categories indicated positive associations between LV systolic and diastolic abnormalities and exposure to PM2.5 [-0.069 (-0.104, -0.033); -0.044 (-0.062, -0.025)] and PM10 [-0.055 (-0.087, -0.022); -0.030 (-0.050, -0.010)] and NO2 [-0.042 (-0.071, -0.013); -0.021 (-0.037, -0.004)], as well as positive associations between lead exposure and LV systolic abnormalities [-0.033 (-0.051, -0.016)].

CONCLUSIONS

Existing evidence shows that specific early markers of HF may be associated with exposure to chemical pollutants. It is recommended to include such endpoints in new longitudinal and case-control studies to confirm further risk associations. These studies should consider co-exposures, account for vulnerable groups, and identify cardiotoxic compounds that may require regulation. When examining the link between myocardial abnormalities and environmental exposure, it is also advisable to explore the supportive use of Adverse Outcome Pathway (AOP) approaches to confirm a causal relationship.

Regulation of sensory perception and motor abilities by brain-specific action of chromatin remodeling factor CHD1

The ATP-dependent chromatin remodeling factor CHD1 (chromodomain-helicase-DNA binding protein 1) is involved in both the de novo assembly and the remodeling of chromatin. Recently, we discovered a crucial role of CHD1 in the incorporation of the histone variant H3.3 in the fly brain illustrated by widespread transcriptional upregulation and shortened lifespan in Chd1-mutant animals. Because many genes linked to sensory perception were dysregulated in Chd1-mutant heads, we studied the role of CHD1 in these processes. Here we show that Chd1-mutant flies have severe defects in their response behavior to olfactory and gustatory but not visual stimuli. Further analyses suggested that poor performance in gustatory response assays was caused by reduced motivation for foraging and feeding rather than defects in taste perception. Moreover, we show that shortened lifespan of Chd1-mutant flies is accompanied by indications of premature functional aging as suggested by defects in negative geotaxis and exploratory walking assays. The latter phenotype was rescued by neuronal re-expression of Chd1, while the olfactory defects were not. Interestingly, we found evidence for indirect regulation of the non-neuronal expression of odorant binding proteins (Obp) by neuronal expression of Chd1. Together, these results emphasize the crucial role of CHD1 activity controlling diverse neuronal processes thereby affecting healthy lifespan.

Modeling the migration of chemicals from food contact materials to food: The MERLIN-expo/VERMEER toolbox

Evaluating the migration of chemicals from food contact materials (FCM) into food is a key step in the safety assessment of such materials. In this paper, a simple mechanistic model describing the migration of chemicals from FCM to food was combined with quantitative property-property relationships (QPPRs) for the prediction of diffusion coefficients and FCM-Food partition coefficients. The aim of the present study was to evaluate the performance of these operational models in the prediction of a chemical's concentration in food in contact with a plastic monolayer FCM. A comparison to experimental migration values reported in literature was conducted. Deterministic simulations showed a good match between predicted and experimental values. The tested models can be used to provide insights in the amount and the type of toxicological data that are needed for the safety evaluation of the FCM substance. Uncertainty in QPPRs used for describing the processes of both diffusion in FCM and partition at the FCM-Food interface was included in the analysis. Combining uncertainty in QPPR predictions, it was shown that the third quartile (75th percentile) derived from probabilistic calculations can be used as a conservative value in the prediction of chemical concentration in food, with reasonable safety factors.

Occurrence of (suspected) genotoxic flavoring substances in Belgian alcohol-free beers

The regulatory landscape of flavorings is evolving, thereby putting pressure on control laboratories to develop analytical methods for a wide range of compounds in various types of food and drinks. In order to improve the monitoring of flavoring substances, a versatile and accurate analytical method using the solvent-assisted flavor evaporation (SAFE) technique coupled to GC-MS(SIM) was developed and validated. Focus was put on authorized flavoring substances requiring specific attention due to a genotoxic concern based on information from European risks assessment reports. Thirty-seven (suspected) genotoxic flavoring substances were analyzed in a selection of ten alcohol-free beers. Five suspected genotoxic compounds (i.e. 1-(2-furyl)-2-propanone, 2-acetylfuran, 2-acetyl-5-methylfuran, 2-acetyl-3,5-dimethylfuran, hex-2-eno-1,4-lactone) as well as two confirmed genotoxic flavoring substances (p-mentha-1,8-dien-7-al, 2,4-pentanedione) were identified and quantified among the selected samples. Low concentrations and natural occurrences of the identified compounds suggested that these were not added as such but rather originated from heat-treatments or from plant-based extracts.

Left ventricular volumes at baseline and outcome in heart failure patients undergoing cardiac resynchronization therapy

Background

Studies evaluating the relationship between baseline left ventricular (LV) volumes and long-term prognosis in heart failure (HF) patients undergoing cardiac resynchronization therapy (CRT) are lacking.

Purpose

To evaluate the association of LV end-systolic and end-diastolic volumes (ESV and EDV) with long-term prognosis in patients with HF treated with CRT.

Methods

Patients from an ongoing institutional HF registry who received CRT according to contemporary guidelines were included. All patients underwent standard transthoracic echocardiography. LV volumes were measured using the biplane method during off-line analysis. Primary end-point included all-cause mortality, implantation of left ventricular assist device or heart transplantation, which were assessed according to the national death registry and case records.

Results

In total, 1165 patients with feasible LV volume assessment were included (mean age 67±10 years; 74.8% males; 55.3% with non-ischemic aetiology of HF). After a median follow-up of 75 (40; 123) months, the primary end-point occurred in 708 (60.8%) patients. Median baseline LV ESV was 151 (108; 198) ml and EDV was 202 (156; 258) ml. All patients were divided into quartiles according to the baseline EDV and ESV: those with larger volumes were significantly younger, more frequently male and had longer QRS durations (p<0.001). Heart failure aetiology, glomerular filtration rate, quality of life and 6-minute walking test distance did not differ significantly between the groups (p>0.05). To investigate the association between long-term prognosis and baseline LV volumes (EDV and ESV), a Cox proportional hazards model was constructed with variables known to influence the mortality of HF patients (age, gender, aetiology, QRS duration, and estimated glomerular filtration rate). When separately included in a multivariate analysis, baseline LV ESV and LV EDV were both independently associated with the primary end-point (p<0.001). To demonstrate hazard change across the range of LV ESV and EDV as continuous variables, an adjusted (for covariates influencing HF mortality) spline curve was drawn, showing an increased mortality risk when the baseline LV ESV and EDV are larger than 100 ml and 200 ml, respectively (Figure).

Conclusion

LV volumes before CRT implantation are independently associated with prognosis during long-term follow-up. Our findings indicate the importance of taking baseline LV remodelling into consideration to identify patients at high mortality risk after CRT implantation.

Funding Acknowledgement

Type of funding source: Public grant(s) – EU funding. Main funding source(s): The author acknowledges funding received from the European Society of Cardiology in form of an ESC Training Grant

Short-term health effects in the general population following a major train accident with acrylonitrile in Belgium

BACKGROUND

Following a train derailment, several tons of acrylonitrile (ACN) exploded, inflamed and part of the ACN ended up in the sewage system of the village of Wetteren. More than 2000 residents living in the close vicinity of the accident and along the sewage system were evacuated. A human biomonitoring study of the adduct N-2-cyanoethylvaline (CEV) was carried out days 14-21 after the accident.

OBJECTIVES

(1) To describe the short-term health effects that were reported by the evacuated residents following the train accident, and (2) to explore the association between the CEV concentrations, extrapolated at the time of the accident, and the self-reported short-term health effects.

METHODS

Short-term health effects were reported in a questionnaire (n=191). An omnibus test of independence was used to investigate the association between the CEV concentrations and the symptoms. Dose-response relationships were quantified by Generalized Additive Models (GAMs).

RESULTS

The most frequently reported symptoms were local symptoms of irritation. In non-smokers, dose-dependency was observed between the CEV levels and the self-reporting of irritation (p=0.007) and nausea (p=0.007). Almost all non-smokers with CEV concentrations above 100pmol/g globin reported irritation symptoms. Both absence and presence of symptoms was reported by non-smokers with CEV concentrations below the reference value and up to 10 times the reference value. Residents who visited the emergency services reported more symptoms. This trend was seen for the whole range of CEV concentrations, and thus independently of the dose.

DISCUSSION AND CONCLUSION

The present study is one of the first to relate exposure levels to a chemical released during a chemical incident to short-term (self-reported) health effects. A dose-response relation was observed between the CEV concentrations and the reporting of short-term health effects in the non-smokers. Overall, the value of self-reported symptoms to assess exposure showed to be limited. The results of this study confirm that a critical view should be taken when considering self-reported health complaints and that ideally biomarkers are monitored to allow an objective assessment of exposure.

Bakers' cyst and tibiofemoral abnormalities are more distinctive MRI features of symptomatic osteoarthritis than patellofemoral abnormalities

OBJECTIVE

To investigate which structural MR abnormalities discriminate symptomatic knee osteoarthritis (OA), taking co-occurrence of abnormalities in all compartments into account.

METHODS

The Netherlands Epidemiology of Obesity (NEO) study is a population-based cohort aged 45-65 years. In 1285 participants (median age 56 years, 55% women, median body mass index (BMI) 30 kg/m(2)), MRI of the right knee were obtained. Structural abnormalities (osteophytes, cartilage loss, bone marrow lesions (BMLs), subchondral cysts, meniscal abnormalities, effusion, Baker's cyst) at 9 patellofemoral and tibiofemoral locations were scored following the knee OA scoring system. Symptomatic OA in the imaged knee was defined following the American College of Rheumatology criteria. Logistic ridge regression analyses were used to investigate which structural abnormalities discriminate best between individuals with and without symptomatic OA, crude and adjusted for age, sex and BMI.

RESULTS

Symptomatic knee OA was present in 177 individuals. Structural MR abnormalities were highly frequent both in individuals with OA and in those without. Baker's cysts showed the highest adjusted regression coefficient (0.293) for presence of symptomatic OA, followed by osteophytes and BMLs in the medial tibiofemoral compartment (0.185-0.279), osteophytes in the medial trochlear facet (0.262) and effusion (0.197).

CONCLUSIONS

Baker's cysts discriminate best between individuals with and without symptomatic knee OA. Structural MR abnormalities, especially in the medial side of the tibiofemoral joint and effusion, add further in discriminating symptomatic OA. Baker's cysts may present as a target for treatment.

[Knowledge, attitude, and practice concerning measles vaccination. Approaches for national vaccination education]

Achievement of the goal to eliminate measles by 2015 set by the European region of the World Health Organization (WHO) necessitates an increase in the willingness of German nationals to get vaccinated. To identify influential factors on vaccination behavior as the basis for communication measures specific to target groups, the Federal Centre for Health Education (BZgA) has conducted two representative surveys on attitude, knowledge, and practice concerning vaccination among parents of children between 0 and 13 years as well as among adolescents and adults. The parents' survey (n = 3,002) revealed that more than one-third see measles as a harmless disease. The survey of adolescents and adults (n = 4,483, 16-85 years) also shows that about one-quarter of the interviewees between 16 and 44 years regarded vaccination against measles as not very important. Moreover, 81 % of adults born after 1970 without sufficient existing vaccine protection were not aware of the new measles vaccination recommendation for this age group. Personal consultation with the physician was regarded as the major source of vaccination information in both surveys. About half of all persons interviewed intended to obtain information about vaccinations on the Internet. The results of these studies were used for the development of a nationwide multilevel BZgA campaign on vaccination protection against measles, its goal being to support medical professionals with comprehensive information and to enable adolescents and young adults via different communication measures to make well-informed vaccination decisions.

Reduction of Bacillus subtilis, Bacillus stearothermophilus and Streptococcus faecalis in meat batters by temperature-high hydrostatic pressure pasteurization

People have a growing preference for fresh, healthy, palatable and nutritious meals and drinks. However, as food deterioration is a constant threat along the entire food chain, food preservation remains as necessary now as in the past. High pressure processing is one of the emerging technologies being studied as an alternative to the classical pasteurization and sterilization treatments of food. Samples of fried minced pork meat were inoculated with strains of Streptococcus faecalis and with sporulating microorganisms like Bacillus subtilis and stearothermophilus. The samples were subjected to several combined temperature-high pressure treatments predicted by the mathematical model applied in Response Surface Methodology. Using the "Box-Behnken" concept, the number of tests for a whole area of pressure-temperature-time-combinations (pressure variation: 50-400 MPa, temperature variation 20-80°C, time variation 1-60 min) could be limited to 15. In the center point of the model, the experimental combination was performed in triple to estimate the experimental variance. All the tests were executed in a randomized order to exclude the disturbing effect of environmental factors. Microbial analysis revealed for each microorganism an important reduction in total plate count, demonstrating a superior pressure resistance of the sporulating microorganisms in comparison with the most pressure resistant vegetative species Streptococcus faecalis. The effect of the medium composition could be neglected, showing little protective effect of, e.g. the fat fraction as seen in heat preservation techniques.

Investigation into the genotoxicity of water extracts from Hypoxis species and a commercially available Hypoxis preparation

We performed an in vitro evaluation of the genotoxic potential of water extracts from four Hypoxis species (Hypoxis hemerocallidea, H. colchicifolia, H. rigidula, H. acuminata) and a commercial preparation thereof using the neutral red uptake (NRU) assay, the alkaline comet assay and the cytome assay in human hepatoma HepG2 cells. The relative cytotoxicity of these samples was established by determining their NI50 values (50% inhibition of NRU), and these results were used for dose-finding in genotoxicity tests. None of the tested extracts were identified as genotoxic in both the alkaline comet assay and cytome assay.

Clinical differentiation between acute appendicitis and acute mesenteric lymphadenitis in children

INTRODUCTION

Acute mesenteric lymphadenitis in children has a clinical presentation very similar to that of acute appendicitis. The aim of this study was to evaluate whether it is possible to clinically differentiate between acute appendicitis and acute mesenteric lymphadenitis in children.

METHODS

A prospective cohort analysis was performed for all children (<17 years) presenting to the emergency department of our institution with acute abdominal pain between June 2005 and July 2006. The relevant clinical parameters, clinical and radiological diagnoses and all management decisions were scored prospectively. Ultrasound was the primary imaging modality for the majority of patients. All patients were re-evaluated until a final diagnosis was attained. The Alvarado score was calculated retrospectively, and a logistic regression model was used to analyze the diagnostic potential of clinical parameters.

RESULTS

289 patients were eligible for analysis. 38 patients had acute mesenteric lymphadenitis, and 69 patients had acute appendicitis as a final diagnosis. The positive predictive values of the clinical diagnosis, the Alvarado score and the logistic regression model were 0.62, 0.81 and 0.79 respectively. Ultrasound had a positive predictive value of 96% for acute appendicitis.

CONCLUSION

It is not possible to accurately distinguish acute mesenteric lymphadenitis from acute appendicitis in children using clinical evaluation alone. Ultrasound should be performed in equivocal cases.

Rehabilitation Programs for Cystic Fibrosis - View from a CF Center

Background:

Rehabilitation programs are comprehensive interventions which effectively improve the health status and reduce costs in chronic respiratory illnesses. Because patients with cystic fibrosis have been discouraged to participate for concerns of microbial cross infection, the efficacy of systematic rehabilitation is unknown for this group.

Methods:

We retrospectively studied 142 cystic fibrosis patients aged 2-46 years who participated in rehabilitation programs taking place in Germany/Switzerland and in Israel, focusing on changes in lung function and weight.

Results:

During 172 stays in 97 patients in Israel and 68 stays in 45 patients rehabilitating in Germany/Switzerland, overall lung function and weight improved. Outcome did not differ between Israel and German/Swiss sites. Interestingly, lung function improved during the initial phase of the stay, whereas weight gain was sustained throughout. The study uncovered gaps in reporting sufficient individual outcome information back to the admitting centre.

Conclusions:

Rehabilitation programs specified for cystic fibrosis patients need to be assessed prospectively to optimize treatment of this life limiting condition.

Mobile bearing knee kinematics change over time. A fluoroscopic study in rheumatoid arthritis patients

BACKGROUND

In a previous fluoroscopy study the motion of a mobile bearing total knee prosthesis was evaluated. That study showed that the axial rotation of the insert was limited. Three possible explanations are given for the limited rotation: low conformity between the femoral component and insert, the fixed anterior position of the insert-tibia pivot point leading to impingement and fibrous tissue formation. While the effect of the conformity on the axial rotation will not change over time, the effect of impingement and fibrous tissue is likely to increase, and thereby further decreasing the axial rotation.

METHODS

In order to accurately assess changes in axial rotation over time in a mobile bearing total knee prosthesis rheumatoid arthritis patient group, patients were evaluated 8 months and 3 years postoperatively using fluoroscopy.

FINDINGS

In comparison with the 8 months evaluation, the rotation of the femoral component (range: -10.8 degrees to 2.8 degrees) and the insert (range: -5.9 degrees to 1.4 degrees) were further limited at 3 years (respectively, -5.9 degrees to 4.9 degrees and -2.8 degrees to 5.4 degrees). Patterns of axial rotation for the femoral component and insert varied considerably between the trials within patients while at the 8 months evaluation no significant difference within patients was observed.

INTERPRETATION

This study shows the importance of re-evaluating knee kinematics over time. The axial rotation of both the femoral component as the insert decreased over time, indicating a kinematic change caused by intrinsic factors. The decline in rotation of the insert could be explained by increased impingement and the formation of fibrous tissue.

Surgical treatment of sigmoid diverticulitis--analysis of predictive risk factors for postoperative infections, surgical complications, and mortality

BACKGROUND AND AIMS

Sigmoid diverticular disease has great clinical importance due to its increasing incidence in the Western world and a broad spectrum of clinical features with potential fatal complications after surgery. The definition of risk factors associated with postoperative infections, surgical complications and mortality could be helpful in clinical decision-making and optimizing perioperative treatment.

MATERIALS AND METHODS

Based on a prospective database, 168 consecutive patients undergoing surgery for sigmoid diverticulitis were included in this study. The association of different potential risk factors such as age, Hinchey classification, type and duration of operation, surgeons' experience, blood loss, comorbidities, and hospital course with perioperative complications and mortality were tested by univariate and multivariate analysis.

RESULTS

Of the 168 patients enrolled in this study, there were 84 male and 84 female. A third of patients were operated as emergency cases (within 24 h after surgical evaluation); 62% underwent open surgery, 35% were treated laparoscopically with a conversion rate of 3%. A blood transfusion received 14% of patients, a surgical infection occurred in 20%, surgical complications appeared in 24% with a necessity for re-exploration in 9.5%. Leakage of the primary anastomosis was seen in 3.3%, whereas a leakage of the Hartmann's stump occurred in 4.3%. Overall in-hospital mortality was 4.1%. Multivariate analysis demonstrated Hinchey classification and intraoperative blood transfusion to be independently associated with postoperative infections, complications and mortality.

CONCLUSION

Hinchey classification and intraoperative blood transfusion are independently associated with a worse perioperative outcome in patients undergoing surgery for sigmoid diverticular disease. While Hinchey classification cannot be influenced per se by the surgeon, outcome might be influenced by reducing the need for intraoperative blood transfusion.

Elevated alpha-amylase but not cortisol in generalized social anxiety disorder

Stress-system dysregulation is thought to increase the risk for anxiety disorders. Here we describe both hypothalamic pituitary adrenal (HPA) axis and autonomic nervous system (ANS) activity in basal non-challenging conditions and after 0.5mg dexamethasone in generalized social anxiety disorder (gSAD) patients. To ensure stress-free sampling we collected saliva and determined cortisol and alpha-amylase (sAA), the latter a relative new marker of autonomic activity. Forty-three untreated gSAD patients without comorbidity were compared with 43 age and gender matched controls in non-stressed conditions on sAA and cortisol after awakening, during the day (including late evening), and after a low dose (0.5mg) of dexamethasone. Cortisol and sAA were analyzed with mixed models. Additional analyses were done with paired t-tests. Apart from the assessments in the morning, gSAD patients had significantly higher diurnal and post-dexamethasone 1600h sAA levels. No differences between gSAD and controls in any cortisol measurements were found. In conclusion, in gSAD in basal, non-stimulated conditions and after dexamethasone, we found hyperactivity of the ANS, as measured with sAA, but not of the HPA-axis. This suggests a relative increased activity of the ANS as compared to the HPA-axis, in line with the observed hyperarousal in gSAD.

Soft-tissue artefact assessment during step-up using fluoroscopy and skin-mounted markers

When measuring knee kinematics with skin-mounted markers, soft tissue and structures surrounding the knee hide the actual underlying segment kinematics. Soft-tissue artefacts can be reduced when plate-mounted markers or marker trees are used instead of individual unconstrained mounted markers. The purpose of this study was to accurately quantify the soft-tissue artefacts and to compare two marker cluster fixation methods by using fluoroscopy of knee motion after total knee arthroplasty during a step-up task. Ten subjects participated 6 months after their total knee arthroplasty. The patients were randomised into (1) a plate-mounted marker group and (2) a strap-mounted marker group. Fluoroscopic data were collected during a step-up motion. A three-dimensional model fitting technique was used to reconstruct the in vivo 3-D positions of the markers and the implants representing the bones. The measurement errors associated with the thigh were generally larger (maximum translational error: 17mm; maximum rotational error 12 degrees ) than the measurement errors for the lower leg (maximum translational error: 11mm; maximum rotational error 10 degrees ). The strap-mounted group showed significant more translational errors than the plate-mounted group for both the shank (respectively, 3+/-2.2 and 0+/-2.0mm, p = 0.025) and the thigh (2+/-2.0 and 0+/-5.9mm, p = 0.031). The qualitative conclusions based on interpretation of the calculated estimates of effects within the longitudinal mixed-effects modelling evaluation of the data for the two groups (separately) were effectively identical. The soft-tissue artefacts across knee flexion angle could not be distinguished from zero for both groups. For all cases, recorded soft-tissue artefacts were less variable within subjects than between subjects. The large soft-tissue artefacts, when using clustered skin markers, irrespective of the fixation method, question the usefulness of parameters found with external movement registration and clinical interpretation of stair data in small patient groups.

The transfer of a LC-UV method for the determination of fenofibrate and fenofibric acid in Lidoses: Use of total error as decision criterion

Two new statistical approaches to assess the validity of the transfer of a LC-UV method for the determination of fenofibrate and fenofibric acid were investigated and compared to the conventional approaches generally used in this domain. These new approaches, namely the Tolerance Interval and the Risk approaches, are based on the simultaneous evaluation of the systematic (or trueness) and random (or precision) errors of the transfer into a single criterion called total error (or accuracy). The results of the transfer showed that only the total error based approaches fulfilled the objective of an analytical method transfer, i.e. to give guarantees that each future measurement made by the receiving laboratory will be close enough to the true value of the analyte in the sample. Furthermore the Risk approach was the most powerful one and allowed the estimation of the risk to have future measurements out of specification in the receiving laboratory, therefore being a risk management tool.

Prediction of the impact of logging activities on forest cover: a case-study in the east province of Cameroon

The objective of this study was to test the value of the concept of the net commercial value of standing timber in predicting the impact of logging activities on forest-cover modifications. A study area was selected in the East province of Cameroon which contains major primary forests and which contributes strongly to national timber production. A Geographic Information System containing ecological and economic variables was used in combination with remote sensing data to define the net commercial value of standing timber in the East province. Taking account of the potential commercial value of standing timber improves our understanding of the spatial determinants of logging activities and of the resulting forest-cover modifications. The occurrence of logging-induced forest-cover modifications increases with the value of forest rent. In one of the study sites, half of the very high rent areas have already been logged. In that site, therefore, it is mostly the low rent or marginal forest areas that remain unlogged. This was not the case, however, throughout the study area as shown by the observations at another site.

Transcription of the unique ruminant class II major histocompatibility complex-DYA and DIB genes in dendritic cells

Dendritic cells (DC) constitute the most effective immune cell population for priming and recalling T cell responses to foreign antigens. DC patrol the peripheral tissues collecting foreign antigen for subsequent presentation by classical class II MHC molecules to T cells in the draining lymph nodes. Since the description of the DYA and DIB class II MHC genes, which are unique to ruminants, no transcript or protein have been reported. Here we provide evidence that these genes are transcribed in cattle and that paired transcription is restricted in afferent lymph to a functionally distinct population of DC. Analysis of lymph node, lung and thymus suggests that tissue DC also transcribe both genes. Cytokine-induced differentiation of cultured monocytes to a DC phenotype is linked with induction of both DYA and DIB transcription. This is consistent with an association of their products with the potent antigen presenting capacity of these cells in cattle.

Cloning, sequence and mRNA expression of bovine interleukin-16

A lambda gt11 cDNA library was constructed using mRNA isolated from Theileria parva-infected bovine lymphocytes. Sequencing of random clones of this library resulted in the identification of a cDNA encoding bovine interleukin-16 (IL-16). The cDNA has an open reading frame of 1134 bp, and a 3' untranslated region of 275 nucleotides with a polyadenylation signal 16 bases upstream from the poly (A) tail. The protein predicted by the cDNA sequence contains 378 amino acids and the level of amino acid homology with the corresponding part of human precursor IL-16 is 79 %. No information is available about the tissue distribution of IL-16 in cattle, therefore we investigated the expression of IL-16 mRNA in bovine lymphoid tissues by reverse-transcription polymerase chain reaction assays. To investigate the potential of IL-16 as an immunoregulatory molecule we also analysed IL-16 mRNA expression in CD4+ and CD8+T-cell clones derived from T. parva-immunised cattle.

Flt-3 ligand, in combination with bovine granulocyte-macrophage colony-stimulating factor and interleukin-4, promotes the growth of bovine bone marrow derived dendritic cells

Culture of bone marrow precursor cells with cytokines, including granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin-4 (IL-4) and the tyrosine kinase receptor binding proteins Flt-3 ligand (Flt-3L) and stem-cell factor (SCF), has previously been shown, in both mouse and human, to result in the generation of large numbers of dendritic cells. We extend these findings to bovine dendritic cells. Culture of bovine bone marrow cells with GM-CSF, IL-4 and either Flt-3L or SCF enhanced the generation of low buoyant-density dendritic cells. However, only the addition of Flt-3L to cells cultured with GM-CSF and IL-4 was shown to increase the number of dendritic cells and induce the differentiation of dendritic cells with potent capacity to stimulate allogeneic T cells and resting CD4+ memory T cells. The effective ability to stimulate T cells was associated with the expression of major histocompatibility complex (MHC) class II molecules and CD80/86 by dendritic cells. Bovine bone marrow derived dendritic cells appeared to be exclusively of myeloid origin because they expressed the myeloid-related antigens CD14, MyD-1 and CD11b.

Immune response of cattle infected with African trypanosomes

Trypanosomosis is the most economically important disease constraint to livestock productivity in sub-Saharan Africa and has significant negative impact in other parts of the world. Livestock are an integral component of farming systems and thus contribute significantly to food and economic security in developing countries. Current methods of control for trypanosomosis are inadequate to prevent the enormous socioeconomic losses resulting from this disease. A vaccine has been viewed as the most desirable control option. However, the complexity of the parasite's antigenic repertoire made development of a vaccine based on the variable surface glycoprotein coat unlikely. As a result, research is now focused on identifying invariant trypanosome components as potential targets for interrupting infection or infection-mediated disease. Immunosuppression appears to be a nearly universal feature of infection with African trypanosomes and thus may represent an essential element of the host-parasite relationship, possibly by reducing the host's ability to mount a protective immune response. Antibody, T cell and macrophage/monocyte responses of infected cattle are depressed in both trypanosusceptible and trypanotolerant breeds of cattle. This review describes the specific T cell and monocyte/macrophage functions that are altered in trypanosome-infected cattle and compares these disorders with those that have been described in the murine model of trypanosomosis. The identification of parasite factors that induce immunosuppression and the mechanisms that mediate depressed immune responses might suggest novel disease intervention strategies.

Cytokine mRNA profiles in trypanotolerant and trypanosusceptible cattle infected with the protozoan parasite Trypanosoma congolense: protective role for interleukin-4?

African trypanosomes are important pathogens of both humans and livestock. We investigated the association of cytokine responses with disease susceptibility in Trypanosoma congolense-infected cattle. Changes in interleukin (IL)-1beta, IL-2, IL-4, IL-5, IL-6, IL-12 p40, tumor necrosis factor-alpha (TFN-alpha), CD40L, and transforming growth factor-beta (TGF-beta) gene expression were compared in peripheral blood mononuclear cells of infected trypanotolerant N'Dama (Bos taurus) and trypanosusceptible Boran (Bos indicus) cattle. Results revealed that IL-2 transcription was decreased in both breeds of cattle at 21 days after infection. IL-12 p40 mRNA expression was increased in N'Dama cattle at 21 days after infection and at a later time in Boran cattle. The highest IL-4 mRNA expression was observed at 32 days after infection in N'Dama cattle. IL-6 mRNA expression increased in Boran cattle at 11 days after infection and was elevated at 21 and 32 days after infection in both breeds. Transcripts for IL-5 were barely detectable throughout the experimental period in both Boran and N'Dama cattle. Expression of TNF-alpha, IL-1beta, and TGF-beta mRNA did not change notably during the course of infection. In summary, differences in the expression of IL-4 and IL-6 mRNA were identified between the two breeds of cattle during infection with T. congolense, suggesting a possible protective role for IL-4 and a disease-promoting role for IL-6 in bovine trypanosomosis.

Trypanosoma congolense infection of trypanotolerant N'Dama (Bos taurus) cattle is associated with decreased secretion of nitric oxide by interferon-gamma-activated monocytes and increased transcription of interleukin-10

The mechanisms whereby trypanotolerant N'Dama cattle control infection with Trypanosoma congolense are unknown. Previous studies have suggested that the monocytes of N'Dama cattle are more highly activated during infection than those of trypanosusceptible Boran cattle. However, we have recently reported that the monocytes of Boran cattle have a reduced capacity to secrete nitric oxide during trypanosome infection. We therefore evaluated the production of nitric oxide by monocytes of trypanotolerant N'Dama cattle infected with T. congolense in response to interferon-gamma, bacterial lipopolysaccharide or trypanosome antigens. Interferon-gamma-induced nitric oxide production was decreased between days 25 and 76 of infection, while lipopolysaccharide-induced secretion of nitric oxide was increased at days 13 and again at day 76 post-infection. Trypanosome antigens did not elicit nitric oxide production. Analysis of interleukin-10 mRNA transcription in peripheral blood leucocytes revealed an increase at time points that coincided with decreased interferon-gamma-induced nitric oxide synthesis. In contrast, interferon-gamma mRNA expression was not changed during infection while tumour necrosis factor-alpha was slightly reduced at day 32 post-infection. Recombinant interleukin-10 suppressed interferon-gamma-induced nitric oxide and tumour necrosis factor-alpha secretion, but not lipopolysaccharide-induced nitric oxide secretion in cultures of peripheral blood mononuclear cells and monocytes of uninfected cattle. These results suggest that the nitric oxide response of monocytes to IFN-gamma but not lipopolysaccharide, is suppressed during infection. The kinetics of the upregulation of interleukin-10 and its biological activity indicate a possible association with the depression of nitric oxide production and control of tumour necrosis factor-alpha.

Bovine stem cell factor: production of a biologically active protein and mRNA analysis in cattle infected with Trypanosoma congolense

The cDNA coding for the soluble form of bovine stem cell factor (boSCFAla165) was cloned and recombinant protein was produced in bacteria as a histidine tagged-protein. The protein was purified from the inclusion bodies in one step by metal chelation chromatography under denaturing conditions. Recombinant bovine SCF was shown to act synergistically with interleukin 3 (IL-3) and erythropoietin (EPO) in stimulating the growth of bone marrow progenitor cells such as colony forming units-granulocyte macrophage (CFU-GM) and burst forming units-erythroid (BFU-E). Analysis of SCF mRNA expression by reverse transcription-polymerase chain reaction (RT-PCR) revealed that the transcripts were detectable in bone marrow, lymph nodes and spleen of cattle, and that the level of transcription was upregulated in lymph nodes of cattle infected with Trypanosoma congolense. Two isoforms of SCF mRNA were amplified by RT-PCR. The availability of recombinant bovine SCF provides a valuable tool for studying the role of SCF in the development, growth and differentiation of bovine hematopoietic cells.

SrZn(VO)(PO4)2 und BaCd(VO)(PO4)2: Zum BaZn(VO)(PO4)2-Typ verwandte, jedoch nicht isotype Vanadylphosphate / SrZn(VO)(PO4)2 and BaCd(VO)(PO4)2: Vanadylphosphates Related but not Isotypic to the BaZn(VO)(PO4 )2 Type

Single crystals of the compounds SrZn(VO)(PO4)2 (I) and BaCd(VO)(PO4)2 (II) have been prepared by solid state reactions in evacuated quartz tubes. X-ray investigations confirmed orthorhombic symmetry, space group D152h-Pbca, lattice constants a/b/c (I): 9.066(1)/9.012(1)/17.513(1) Å and (II); 8.838(4)/8.915(4)/19.374(9) Å, Z = 8. Initially assumed isotypies of (I) and (II) to BaZn(VO)(PO4)2 proved to be erroneous considering significant details of the connectivity of the ZnO4 and PO4 tetrahedra (I) and the coordination sphere of cadmium (II), respectively. The similarities and differences of the crystal chemistry relation to (I) and (II) are discussed with respect to BaZn(VO)(PO4)2. The Coulomb terms of the lattice energies of vanadyl M2(VO)(PO4)2 and divanadyl M(VO)2(PO4)2 phosphates are shown.

Zum Mineral Johillerit verwandte Oxovanadate RbCd4V3O12 und TlCd4V3O12 / Oxovanadates RbCd4V3O12 and TlCd4V3 O12 Related to the Mineral Johillerite

Single crystals of I RbCd4V3O12 and TlCd4V3O12 II have been prepared by solid state reactions in closed iron tubes. The compounds crystallize closely related to the Johillerite structure in the space group C6 2h- C2/c with I: a = 13.058(3); b - 13.528(3), c = 7 .0 6 0 (2 )Å , β = 114.88(2)°; II: a = 12.999(6), b = 13.527(7), c = 7.055(3) Å , β = 114.88(4)°, Z = 4. Special features are the loss of Cu2+ in order to gain an additional Cd2+ position. The crystal structure is discussed with respect to related compounds of the Johillerite type.

Die zu BaMg2Cu8V6O26 isotypen Cadmium-Kupferoxovanadate KCd0,67Cu4,33V3O13, RbCd0,5Cu4,5V3O13 sowie TlCd0,5Cu4,5V3O13 /The BaMg2Cu8V6O26 isotypic Cadmium-Cooperoxovanadates KCd0,67Cu4,33V3O13, RbCd0,5Cu4,5V3O13 and TlCd0,5Cu4,5V3O13 /

Single crystals of KCd0,67Cu4,33V3O13 (I), RbCd0,5Cu4,5V3O13 (II) and TlCd0,5Cu4,5V3O13 (III) have been prepared by crystallization from melts. X-ray analysis led to monoclinic symmetry, space group C2 2h-P21/m (Nr. 11) and the lattice constants (I) - (III): a = 10.728(1), 10.746(3), 10.746(3), b = 6.155(1), 6 .163(2), 6.175(2), c = 8.363(2), 8.350(2), 8.337(3) Å , β = 97.69(2), 97.73(2), 97.61(5)°, Z = 2. The crystal structures are isotypic to the BaMg2CU8V6 O26 type. Cu2+ occurs in square pyramidal and unusual trigonal bipyram idal coordination by oxygen . The MgO6 octahedra of the aristo type BaMg2Cu8V6O26 are statisti­cally occupied by cadmium and copper. The distortion of the (Cd /Cu)O6 octahedra is discus­sed with respect to the polyhedra network.

Synthese und Röntgen-Strukturuntersuchung von Rb4Cd(VO)(V2O7)2Cl und Tl4Cd(VO)(V2O7)2Cl / Synthesis and X-Ray Structure Analysis of Rb4Cd(VO)(V2O7)2Cl und Tl4Cd(VO)(V2O7)2Cl

Single crystals of (I) Rb4Cd(VO)(V2O7)2Cl und Tl4Cd(VO)(V2O7)2Cl have been prepared by flux techniques. The compounds were examined by X-ray analysis. They crystallize with tetragonal symmetry, space group C1 4-P4 with (I): a=9.142(1); c=5.525(1), (II): a=9.150(1), c=5.405(1) A, Z = 4. Both compound belong to the K4CuV5O15Cl-Type. V (l) forms V2O7 double tetrahedra, connected by square V(2)O5 pyramids and CdO4Cl2 octahedra. The short V(2)-O distance indicates a vanadyl group.

The nucleotide sequence of the bovine interleukin-5-encoding cDNA

The nucleotide (nt) sequence encoding the bovine homologue of interleukin-5 (boIL-5) was determined. Total cDNA generated from stimulated bovine peripheral blood lymphocytes was used to amplify the boIL-5 gene using primers based on the 5' and 3' untranslated regions of the ovine IL-5 cDNA sequence. The boIL-5 coding sequence is 405 bp long, coding for a 15.2 kDa precursor protein of 134 amino acids (aa). Cleavage of a putative signal peptide of 19 aa yields a mature form of 13.1 kDa. Comparisons at the nt level revealed 96%, 81%, 74% and 73% identity with the ovine, human, mouse and rat IL-5 sequences, respectively, and 97%, 66%, 59% and 58% aa identity, respectively.

Nitric oxide synthesis is depressed in Bos indicus cattle infected with Trypanosoma congolense and Trypanosoma vivax and does not mediate T-cell suppression

Infection with African trypanosomes causes the diseases sleeping sickness in humans and nagana in cattle in sub-Saharan Africa. Suppression of cellular immune responses is a feature of trypanosomiasis in bovine, human, and murine hosts. Some aspects of immunosuppression in the murine model are mediated by nitric oxide (NO) produced by gamma interferon (IFN-gamma)-activated macrophages. We have investigated whether a similar mechanism is responsible for T-cell unresponsiveness in bovine trypanosomiasis. Bovine monocytes and macrophages from uninfected cattle and activated in vitro with IFN-gamma produced NO; however, this response was down-regulated in infected cattle. Similarly, the expression of inducible NO synthase messenger RNA was depressed in macrophages of infected cattle. Proliferation of mononuclear cells of trypanosome-infected cattle cultured with mitogen or trypanosome antigens was unchanged by the addition of an NO synthase inhibitor. Lymphocytes of infected cattle secreted interleukins with T-cell growth factor activity after in vitro activation with mitogens but not after activation with trypanosome antigens. Although lymph node cells secreted IFN-gamma after in vitro activation, ex vivo expression of mRNA was depressed. In contrast, the level of expression of interleukin 10 mRNA was higher during infection. We conclude that NO is not involved in the loss of T-cell proliferative function associated with trypanosomiasis in cattle and that, in contrast to the mouse model, the capacity of monocytes and macrophages to produce NO is actually down-regulated in infected cattle.

Cloning of a cDNA encoding bovine erythropoietin and analysis of its transcription in selected tissues

A bovine cDNA encoding erythropoietin (Epo) was isolated by polymerase chain reaction (PCR) amplification and screening of a bovine kidney cDNA library. The sequenced cDNA has a length of 1312 bp and an open reading frame that encodes a predicted 192-amino-acid (aa) protein, including a putative signal sequence of 25 aa. A mature protein of 167 aa (18.4 kDa) results upon cleavage of the putative signal peptide. The deduced bovine mature Epo peptide exhibits 96, 88, 83, 82 and 79% sequence identity to that of sheep, swine, human, monkey and rat, respectively. The expression of the bovine Epo gene in tissues from a severely anemic calf, bovine fetus and a healthy steer was analysed by a competitive RT-PCR method. In kidneys of the severely anemic calf, Epo mRNA levels increased 60-fold relative to that from the kidneys of the healthy steer. Epo mRNA levels were threefold higher in the liver of the bovine fetus than that in its kidneys. Low levels of Epo transcripts were detected in RNA from spleen of the severely anemic calf and the bovine fetus. No Epo transcripts were detectable in spleen from the healthy steer.

A standardisation approach to the control of socioeconomic confounding in small area studies of environment and health

OBJECTIVE

To assess how effectively a routine adjustment can be made for socio-economic confounding in small area studies of environment and health using indirect standardisation and small area deprivation indices, including analysis of the appropriate size of population unit on which to base the deprivation index and the importance of region and urban/rural status as axes of stratification.

METHODS

Standardised morbidity ratios were calculated for cancers in Great Britain for 1981 and standardised mortality ratios for all cause mortality in Great Britain between 1982 and 1985. Deprivation indices were calculated for enumeration districts and wards from 1981 small area census statistics. Cancers and deaths were allocated to enumeration districts via their postcode. Standardised morbidity and mortality ratios were calculated by quintile of enumeration district according to the deprivation index. Standardised mortality ratios were further analysed by deprivation of ward, region, and urban/rural status.

RESULTS

Strong relationships were found between all cause mortality and the incidence of selected cancers and deprivation quintile-there was up to a twofold difference in lung cancer incidence between the highest and lowest quintile. The deprivation index can be used to measure gradients of deprivation according to the distance from industrial sites. The deprivation index for enumeration districts showed similar discrimination of mortality as the index forwards. There is some interaction between deprivation and region in their effect on the standardised mortality ratios, leading to a small bias in the estimation of expected numbers if this is not taken into account. The relationship between deprivation, urban/rural status, and mortality is complex and confounded by region, but mortality tends to be higher in urban than in rural areas within quintiles of deprivation.

DISCUSSION

Whether calculated for enumeration districts or wards, the main problems in the interpretation of the deprivation index may be its limited correlation with the risk factors of interest and its concentration on present rather than past socioeconomic status. Indirect standardisation based on stratification for deprivation and other variable involves a trade off between bias and precision in determining the fineness and the number of axes of stratification. Some bias may occur due to interaction between region and deprivation and the effects of urban/rural status. Complementary approaches including modeling and proportional mortality or morbidity analyses may be needed and the possibility of residual socioeconomic confounding must always be considered.

CONCLUSION

There is potential for important socioeconomic confounding in small area studies of environmental pollution and health where the health outcome under examination has a strong relationship to socioeconomic status and where the putative excess risk due to pollution may be small. One method of controlling for confounding is to use an ecological measurement of deprivation in small areas, and to adjust for deprivation by indirect standardisation. However, residual socioeconomic confounding can be expected, which may seriously complicate the interpretation of small area studies.

Cloning of the bovine interleukin-3-encoding cDNA

Interleukin-3 (IL-3) is one of the cytokines that act during the early and late stages of blood cell formation. To enable the study of the role of IL-3 in bovine haemopoietic stem cell differentiation, the polymerase chain reaction was used to amplify an IL-3 cDNA from first-strand cDNAs prepared from RNA isolated from 4- and 5-hour concanavalin-A-stimulated peripheral blood lymphocytes (PBL) from N'Dama cattle. An analysis of the cDNA sequence reveals that it contains a 432-nucleotide (nt) open reading frame which codes for 144 amino acids (aa). Cleavage of the putative signal peptide consisting of the first 17 aa yields the mature form of the protein (14.5 kDa). Comparisons of the bovine IL-3 sequence with the sheep, human and mouse IL-3 sequences show that the bovine sequence shares 90.7, 55.8 and 51.9% nt identity, respectively, in the coding region, and 85.4, 35 and 27.7% aa identity, respectively.