Purification of Human Complement Component C4 and Sample Preparation for Structural Biology Applications

Activated complement component C4 (C4b) is the nonenzymatic component of the classical pathway (CP) convertases of the complement system. Preparation of C4 and C4b samples suitable for structural biology studies is challenging due to low yields and complexity of recombinant C4 production protocols reported so far and heterogeneity of C4 in native sources. Here we present a purification protocol for human C4 and describe sample preparation methods for structural investigation of C4 and its complexes by crystallography, small angle X-ray scattering, and electron microscopy.

Functional implications of MIR domains in protein O-mannosylation

Protein O-mannosyltransferases (PMTs) represent a conserved family of multispanning endoplasmic reticulum membrane proteins involved in glycosylation of S/T-rich protein substrates and unfolded proteins. PMTs work as dimers and contain a luminal MIR domain with a β-trefoil fold, which is susceptive for missense mutations causing α-dystroglycanopathies in humans. Here, we analyze PMT-MIR domains by an integrated structural biology approach using X-ray crystallography and NMR spectroscopy and evaluate their role in PMT function in vivo. We determine Pmt2- and Pmt3-MIR domain structures and identify two conserved mannose-binding sites, which are consistent with general β-trefoil carbohydrate-binding sites (α, β), and also a unique PMT2-subfamily exposed FKR motif. We show that conserved residues in site α influence enzyme processivity of the Pmt1-Pmt2 heterodimer in vivo. Integration of the data into the context of a Pmt1-Pmt2 structure and comparison with homologous β-trefoil – carbohydrate complexes allows for a functional description of MIR domains in protein O-mannosylation.

Risk factors for African swine fever incursion in Romanian domestic farms during 2019

African swine fever (ASF) entered Georgia in 2007 and the EU in 2014. In the EU, the virus primarily spread in wild boar (Sus scrofa) in the period from 2014-2018. However, from the summer 2018, numerous domestic pig farms in Romania were affected by ASF. In contrast to the existing knowledge on ASF transmission routes, the understanding of risk factors and the importance of different transmission routes is still limited. In the period from May to September 2019, 655 Romanian pig farms were included in a matched case-control study investigating possible risk factors for ASF incursion in commercial and backyard pig farms. The results showed that close proximity to outbreaks in domestic farms was a risk factor in commercial as well as backyard farms. Furthermore, in backyard farms, herd size, wild boar abundance around the farm, number of domestic outbreaks within 2 km around farms, short distance to wild boar cases and visits of professionals working on farms were statistically significant risk factors. Additionally, growing crops around the farm, which could potentially attract wild boar, and feeding forage from ASF affected areas to the pigs were risk factors for ASF incursion in backyard farms.

α-Helix or β-Turn? An Investigation into N-Terminally Constrained Analogues of Glucagon-like Peptide 1 (GLP-1) and Exendin-4

Peptide agonists acting on the glucagon-like peptide 1 receptor (GLP-1R) promote glucose-dependent insulin release and therefore represent important therapeutic agents for type 2 diabetes (T2D). Previous data indicated that an N-terminal type II β-turn motif might be an important feature for agonists acting on the GLP-1R. In contrast, recent publications reporting the structure of the full-length GLP-1R have shown the N-terminus of receptor-bound agonists in an α-helical conformation. To reconcile these conflicting results, we prepared N-terminally constrained analogues of glucagon-like peptide 1 (GLP-1) and exendin-4 and evaluated their receptor affinity and functionality in vitro; we then examined their crystal structures in complex with the extracellular domain of the GLP-1R and used molecular modeling and molecular dynamics simulations for further investigations. We report that the peptides' N-termini in all determined crystal structures adopted a type II β-turn conformation, but in vitro potency varied several thousand-fold across the series. Potency correlated better with α-helicity in our computational model, although we have found that the energy barrier between the two mentioned conformations is low in our most potent analogues and the flexibility of the N-terminus is highlighted by the dynamics simulations.

Solution Structures of Complement C2 and Its C4 Complexes Propose Pathway-specific Mechanisms for Control and Activation of the Complement Proconvertases

The lectin (LP) and classical (CP) pathways are two of the three main activation cascades of the complement system. These pathways start with recognition of different pathogen- or danger-associated molecular patterns and include identical steps of proteolytic activation of complement component C4, formation of the C3 proconvertase C4b2, followed by cleavage of complement component C2 within C4b2 resulting in the C3 convertase C4b2a. Here, we describe the solution structures of the two central complexes of the pathways, C3 proconvertase and C3 convertase, as well as the unbound zymogen C2 obtained by small angle x-ray scattering analysis. We analyzed both native and enzymatically deglycosylated C4b2 and C2 and showed that the resulting structural models were independent of the glycans. The small angle x-ray scattering-derived models suggest a different activation mode for the CP/LP C3 proconvertase as compared with that established for the alternative pathway proconvertase C3bB. This is likely due to the rather different structural and functional properties of the proteases activating the proconvertases. The solution structure of a stabilized form of the active CP/LP C3 convertase C4b2a is strikingly similar to the crystal structure of the alternative pathway C3 convertase C3bBb, which is in accordance with their identical functions in cleaving the complement proteins C3 and C5.

Structural Basis for the Function of Complement Component C4 within the Classical and Lectin Pathways of Complement

Complement component C4 is a central protein in the classical and lectin pathways within the complement system. During activation of complement, its major fragment C4b becomes covalently attached to the surface of pathogens and altered self-tissue, where it acts as an opsonin marking the surface for removal. Moreover, C4b provides a platform for assembly of the proteolytically active convertases that mediate downstream complement activation by cleavage of C3 and C5. In this article, we present the crystal and solution structures of the 195-kDa C4b. Our results provide the molecular details of the rearrangement accompanying C4 cleavage and suggest intramolecular flexibility of C4b. The conformations of C4b and its paralogue C3b are shown to be remarkably conserved, suggesting that the convertases from the classical and alternative pathways are likely to share their overall architecture and mode of substrate recognition. We propose an overall molecular model for the classical pathway C5 convertase in complex with C5, suggesting that C3b increases the affinity for the substrate by inducing conformational changes in C4b rather than a direct interaction with C5. C4b-specific features revealed by our structural studies are probably involved in the assembly of the classical pathway C3/C5 convertases and C4b binding to regulators.

A foot and mouth disease simulation exercise involving the five Nordic countries

Simulation exercises are considered a very valuable tool for testing contingency plans established for the control and eradication of rapid spreading animal diseases such as foot and mouth disease, classical swine fever and avian influenza. An inter-Nordic simulation exercise was conducted in 2005 with the objective of testing the national foot and mouth disease contingency plans adopted respectively by Denmark, Finland, Iceland, Norway and Sweden. The Central Veterinary Administrations of the five countries jointly prepared a scenario which involved about 40 livestock holdings, 4 reindeer flocks, 6 slaughterhouses and approximately 500 people. An Excel spreadsheet with information on the events to take place and the timetable to follow during the exercise was a valuable tool for ensuring that the exercise was kept on track. The evaluation of the exercise dealt both with inter-Nordic activities and the activities of individual countries.

Comparison of different culture conditions for human mesenchymal stromal cells for clinical stem cell therapy

OBJECTIVE

Mesenchymal stromal cells (MSCs) from adult bone marrow (BM) are considered potential candidates for therapeutic neovascularization in cardiovascular disease. When implementing results from animal trials in clinical treatment, it is essential to isolate and expand the MSCs under conditions following good manufacturing practice (GMP). The aims of the study were first to establish culture conditions following GMP quality demands for human MSC expansion and differentiation for use in clinical trials, and second to compare these MSCs with MSCs derived from culture in four media commonly used for MSC cultivation in animal studies simulating clinical stem cell therapy.

MATERIAL AND METHODS

Human mononuclear cells (MNCs) were isolated from BM aspirates by density gradient centrifugation and cultivated in a GMP-accepted medium (EMEA medium) or in one of four other media.

RESULTS

FACS analysis showed that the plastic-adherent MSCs cultured in EMEA medium or in the other four media were identically negative for the haematopoietic surface markers CD45 and CD34 and positive for CD105, CD73, CD90, CD166 and CD13, which in combined expression is characteristic of MSCs. MSC stimulation with vascular endothelial growth factor (VEGF) increased expression of the characteristic endothelial genes KDR and von Willebrand factor; the von Willebrand factor and CD31 at protein level as well as the capacity to develop capillary-like structures.

CONCLUSIONS

We established culture conditions with a GMP compliant medium for MSC cultivation, expansion and differentiation. The expanded and differentiated MSCs can be used in autologous mesenchymal stromal cell therapy in patients with ischaemic heart disease.

Pathophysiological Aspects of Nocturia in a Danish Population of Men and Women Age 60 to 80 Years

PURPOSE

We applied the International Continence Society Guidelines and categorized men and women with nocturia 2 or more times a night in pathophysiological groups based on selected lower urinary tract symptoms, clinical examination, frequency volume charts and urodynamics, and categorized the most likely pathophysiological causes of nocturia.

MATERIALS AND METHODS

Participants were randomly selected among respondents in a population study of 4,000 individuals 60 to 80 years old living in Copenhagen County. Nocturia was assessed using the new and validated Nocturia, Nocturnal Enuresis, and Sleep-interruption Questionnaire. Nocturic (2 or more voids) or control (less than 1 void) status was assessed by a 3-day frequency volume chart. Participants were interviewed regarding lower urinary tract symptoms, and physical examination was performed. Nocturia pathophysiology was divided in 4 groups according to frequency volume chart variables, that is nocturnal polyuria, low bladder capacity, nocturnal polyuria and low bladder capacity in combination, and polyuria. Spontaneous flow rate and post-void residual urine were determined, and invasive urodynamic examination was performed in patients.

RESULTS

Of 1,111 eligible individuals 75 patients and 75 controls were included. More patients vs controls had daytime frequency, urgency and urge incontinence. However, the difference was not significant in men. Nocturnal polyuria was the only pathophysiological finding that differed significantly in prevalence between patients and controls. The most prevalent urodynamic finding in patients was detrusor overactivity incontinence (26%) in women and detrusor overactivity (64%) in men.

CONCLUSIONS

Urgency in women, and symptoms suggestive of bladder outlet obstruction in men were the major complaints. Frequency volume charts demonstrated that 55% of patients had nocturnal polyuria which was significantly more than controls. From frequency volume chart variables alone we could categorize 84% of the patients. When symptoms and urodynamic examination were added to the assessment, the most likely cause of nocturia was categorized in 96% of participants.

Risk factors for Actinobacillus pleuropneumoniae serotype 2 infection in Danish genetic specific pathogen-free pig herds

Between 1994 and 1998, 297 genetic specific pathogen-free (spf) pig herds participated in a monthly clinical and serological monitoring programme for infection with Actinobacillus pleuropneumoniae serotype 2 (ap-2). The average annual herd-level incidence was 3.4 per cent but there was a significant decreasing trend. A risk index, summing up the exposure from ap-2-infected neighbouring pigs within a 3 km radius, was derived from a geographical information system. A survival analysis indicates that the risk of ap-2 infection increased in proportion to the risk index, suggesting that local spread of ap-2 from infected neighbours was a significant factor. However, herd-specific purchase policies were not apparently associated with the risk of ap-2 infection.

The influence of freezing and storage on the characteristics and functions of human mesenchymal stromal cells isolated for clinical use

BACKGROUND

Studies have shown that stem cell therapy could be a novel option for improving neovascularization and cardiac function in patients with ischemic heart disease. Human mesenchymal stromal cells (MSC) have generated wide interest in the clinical setting because of their ability to regenerate tissue. The aim of the study was to test whether freezing and storage of human BM mononuclear cells (BM-MNC) and ex vivo-expanded MSC influenced their phenotypic and functional characteristics as well as proliferation capacity.

METHODS

MNC were isolated from BM and divided into two portions: one part was immediately cultured (MSC P0) whereas the second part was frozen for a week before cultivation and analysis (F-MSC P1). Confluent MSC (P0) were harvested and divided: one was analyzed as MSC P1 and the other was frozen for a week before further cultivation and analysis as F-MSC P2.

RESULTS

MSC P1, F-MSC P1 and F-MSC P2 had similar proliferation capacities and demonstrated almost identical expression levels of markers characteristic for MSC. The capacity to form endothelial vascular structures was independent of freezing.

DISCUSSION

The proliferation and differentiation capacity as well as the cellular characteristics were identical in cultivated MSC derived from freshly isolated BM-MNC and MSC derived after freezing and storage of either freshly isolated BM-MNC or ex vivo-cultivated MSC. This highlights the potential clinical use of MSC in patients with cardiac and degenerative diseases, as it would be possible to inject MSC obtained from the same BM aspiration at different time points.

Network analysis of Danish cattle industry trade patterns as an evaluation of risk potential for disease spread

Trade patterns of animal movements in a specific industry are complex and difficult to study because there are many stakeholders, premises that are heterogeneously spread over the country, and a highly dynamic flow of animals exists among them. The Danish cattle industry was defined as a network of animal movements and graph theory was used to analyse the movements of cattle within this network. A premise was defined as a farm, an abattoir or a market. These premises constituted the network nodes in the graph and the animal movements between them were the links. In this framework, each premise had a sub-network of other premises to which it was linked by these animal movements. If no movement of animals were registered for a specific farm, then the sub-network for that premise consisted of only that premise. Otherwise, the sub-network linked the premise of interest to all premises from which and to which animals were moved, as long as there was a path linking animal movements to that specific premise. This approach allowed visualization and analyses of four levels of organization that existed in Denmark animal registers: (1) the animal that was moved, (2) the movements of all animals between two premises, (3) the specific premise network, and (4) the overall industry network. When contagious animals are moved from one premise to another, then to a third and so forth, these movements create a path for potential transfer of pathogens. The paths within which pathogens are present identify the transmission risks. A network of animal movements should provide information about pathogen transmission and disease spread. The network of the Danish cattle industry network was a directed scale-free graph (the direction of a movement was known), with an in-degree power of 2 an out-degree power of 1.46, consisted of 29,999 nodes, and 130,265 movements during a 6-month period. The in clustering coefficient was calculated to be 0.52 for the inward direction (movement to), while it was 0.02 for the outward direction (movement from). In Denmark, the cattle movements between premises demonstrated a large degree of heterogeneity. This heterogeneity in movements between farms should be used to evaluate the risk potential of disease transmission for each premise and must be considered when modelling disease spread between premises. The objective of this research was to describe the network of animal movements and not just the animal movements per se.

Labelling of human mesenchymal stem cells with indium-111 for SPECT imaging: effect on cell proliferation and differentiation

PURPOSE

Stem cell therapy seems to be a new treatment option within cardiac diseases to improve myocardial perfusion and function. However, the delivery and traceability of the cells represent a problem. Radioactive labelling with 111In could be a method for tracking mesenchymal stem cells (MSCs). However, 111In could influence the viability and differentiation capacity of MSCs, which would limit its use. Therefore, the aim of this study was to evaluate the influence of 111In labelling in doses relevant for SPECT imaging in humans on the viability and differentiation capacity of human MSCs.

METHODS AND RESULTS

Human MSCs isolated from bone marrow were incubated with 111In-tropolone (15-800 Bq/cell). The labelling efficiency was approximately 25% with 30 Bq/cell 111In. The MSC doubling time was 1.04+/-0.1 days and was not influenced by 111In within the range 15-260 Bq/cell. Using 30 Bq 111In/cell it was possible to label MSCs to a level relevant for clinical scintigraphic use. With this dose, 111In had no effect on characteristic surface and intracellular markers of cultured MSCs analysed both by flow cytometry and by real-time polymerase chain reaction. Further, the labelled MSCs differentiated towards endothelial cells and formed vascular structures.

CONCLUSION

It is possible to label human MSCs with 111In for scintigraphic tracking of stem cells delivered to the heart in clinical trials without affecting the viability and differentiation capacity of the MSCs. This creates an important tool for the control of stem cell delivery and dose response in clinical cardiovascular trials.

Biosecurity in 121 Danish sow herds

Herds are under constant risk of introducing new pathogens from different sources. In this article we describe biosecurity practices in Danish sow herds. Between December 1, 1999 and February 29, 2000, 121 sow units were interviewed regarding biosecurity on the site. The questionnaire contained 62 questions. The 121 units were situated in three areas with different swine densities. Sow units were described by their sizes (units with >110 sows were regarded as large herds) and health status (SPF herds or conventional herds). Of the 121 sow herds, 63 (52%) sold weaners. Most sow units (71%) used delivery facilities for the picking up of weaners, but half of these did not have a barrier between the loading area and the stable while loading. In 19% of the units, weaners were picked up directly from the stable, and in 10% the truck driver had access to the stables. Most units required the vehicle to be cleaned (16%) or cleaned and disinfected (48%) before the transport; large sites and SPF sites more often required stricter biosecurity measures, for example a quarantine period before the transport of weaners.

Validity and Reliability of a Questionnaire for Evaluating Nocturia, Nocturnal Enuresis and Sleep-Interruptions in an Elderly Population

OBJECTIVES

To validate a new questionnaire evaluating nocturia, nocturnal enuresis and sleep-interruptions in an elderly population of men and women in Denmark.

METHODS

The Nocturia, Nocturnal Enuresis and Sleep-interruption Questionnaire (NNES-Q) emerged from review of the literature and expert consensus. The questionnaire was a subset of a larger questionnaire comprising several domains on health status and voiding. Convergent and discriminatory validity was assessed in an unselected population of 2000 men and 2000 women 60-80 years old. To test reproducibility, 400 respondents were mailed a separate questionnaire 2 weeks apart. A subgroup of men and women with and without nocturia was used for evaluating reliability of number of nocturia episodes.

RESULTS

A total of 2825 (70.6%) filled in the questionnaire. A decrease in health status was correlated with increasing bother (range: -0.25 to -0.36, p<0.001, Spearman's r). These findings indicate acceptable convergent validity. Significant discriminatory validity was proven in separate groups of symptom severity (p<0.0001, Kruskal-Wallis test). Median kappa was 0.70 (range 0.58-0.86) indicating substantial agreement in the retest analysis. Number of nocturia episodes in questionnaires correlated with frequency volume charts (Spearman's rho 0.88; p<0.001).

CONCLUSION

These data support that the NNES-Q has a good discriminatory and convergent validity, and is reliable over time. The NNES-Q may be useful in epidemiological studies and may also have a potential in daily clinical work up in patients with nocturia and nocturnal enuresis.

Changes in circulating mesenchymal stem cells, stem cell homing factor, and vascular growth factors in patients with acute ST elevation myocardial infarction treated with primary percutaneous coronary intervention

OBJECTIVE

To investigate the spontaneous occurrence of circulating mesenchymal stem cells (MSC) and angiogenic factors in patients with ST elevation acute myocardial infarction (STEMI) treated with primary percutaneous coronary intervention (PCI).

DESIGN

In 20 patients with STEMI, blood samples were obtained on days 1, 3, 7, 14, 21, and 28 after the acute PCI. Fifteen patients with a normal coronary angiography formed a control group. MSC (CD45-/CD34-), plasma stromal derived factor 1 (SDF-1), vascular endothelial growth factor A (VEGF-A), and fibroblast growth factor 2 (FGF-2) were measured by multiparametric flow cytometry and enzyme linked immunosorbent assay (ELISA).

RESULTS

Circulating CD45-/CD34- cells were significantly decreased on day 7 compared with day 3. Cell counts normalised one month after the acute onset of STEMI. The changes were mainly seen in patients with a large infarction. Plasma SDF-1 increased significantly from day 3 to day 28, and VEGF-A and FGF-2 increased significantly from day 7 to day 28.

CONCLUSIONS

Spontaneous sequential fluctuations in MSC and the increase in vascular growth factor concentrations after STEMI suggest that the optimal time for additional stem cell therapy is three weeks after a myocardial infarction to obtain the maximum effects by stimulating endogenous growth factors on the delivered stem cells.

Lower Urinary Tract Symptoms in the Danish Population: A Population-Based Study of Symptom Prevalence, Health-Care Seeking Behavior and Prevalence of Treatment in Elderly Males and Females

OBJECTIVE

To estimate the prevalence of LUTS in the elderly Danish population. Furthermore to evaluate the quality of life, the health-care seeking behavior and the prevalence of treatment with relation to LUTS.

METHODS

A mailed questionnaire was sent to a random sample of 8700 men and 1000 females above 50-years. The questionnaire included five demographic questions, the I-PSS and questions concerning previous physician contact and treatment with relation to LUTS.

RESULTS

The questionnaire was returned by 61.5% of the males and 47.7% of the females. The median I-PSS was 4 in males and 3 in females. Overall 28% of males and 20% of females had significant LUTS (I-PSS>7). A significant increase in the total burden of symptoms with increasing age was found in males whereas a clear age-trend was not found in females. Overall 9.2% of males and 8.2% of females had seen a physician within the last two years for voiding problems. A high proportion of subjects with moderate or even severe symptoms had not seen a physician within two years due to voiding problems. Of males 13.3% had previous been or were currently being treated for voiding problems while the corresponding number in females was 10.9%. These subjects had significantly more symptoms than untreated age-matched subjects.

CONCLUSION

Lower urinary tract symptoms are common in elderly Danish males and females. Overall the same pattern for health-care seeking behavior with regard to LUTS is seen in males and females and the overall treatment prevalence is similar. For both genders it is worth noting that a substantial proportion of subjects with a high symptom burden had not visited their physician within two years and further that subjects who have been treated for LUTS have a higher symptom levels than their untreated peers.

Biosecurity in 116 Danish fattening swineherds: descriptive results and factor analysis

Biosecurity measures are important for the herd's protection against diseases and also to provide nationwide protection against the introduction of exotic diseases. In this paper, we describe the farmers' choices and routines regarding biosecurity in Danish fattening herds. Overall, 116 Danish swine fattening herds in three areas of different pig density were interviewed. Of these herds, 78% purchased weaners from one sow herd only, whereas 10% purchased from >5 sow herds during 1 year. Large herds (>500 finishers) purchased weaners more often than smaller herds (< or =500 finishers). Only two swine producers purchased weaners from a market. Almost all herds (95%) received weaners from one sow herd at one time, and only one herd received from >5 sow herds in one batch. Twenty-one percent did not use an effective barrier between the loading area and the stables when delivering pigs for slaughter. Entry rooms (in which clothing and boots are changed) were common at the farm, and the numbers of visitors were generally low (<10 visitors a year). Factor analysis was performed to find underlying structures of the biosecurity measures in the herd; four factors were chosen (eigenvalue > 3.10). A site scoring high on factor 1 was a large SPF herd, which received weaners from a single source, had biosecurity requirements for the transport vehicles, and had a high level of biosecurity for visitors. A site scoring high on factor 2 was a multi-site farm, which had personnel working on more than one of the sites, only received weaners from one sow herd, had delivering herds placed close to the participating site, and transported animals themselves. A site scoring high on factor 3 was a site which hired commercial transport for slaughter, was situated far from the abattoir and had a high level of biosecurity when loading pigs. A production site scoring high on factor 4 was a large site, which used all-in/all-out management, washed and disinfected between each group, and purchased many weaners.

Repeatability of cystometry and pressure-flow parameters in female patients

The repeatability of cystometric and pressure-flow data was studied in 31 female patients. The measured parameters had poor correlation coefficients, and logarithmic transforming of the data was generally not warranted. Previous studies and statistical methods of reliability measurement are reviewed. It is suggested as a subject for future studies, that urodynamic measurements are repeated in each patient so that confidence limits can be established within disease entities.

Monitoring porcine reproductive and respiratory syndrome virus infection status in swine herds based on analysis of antibodies in meat juice samples

An indirect ELISA test was developed as a novel tool aimed at monitoring the herd infection status of swine herds. Meat juice samples from pig carcasses were analysed for the presence of antibodies against porcine reproductive and respiratory syndrome virus (PRRSV). A study of samples from herds with known PRRS status was undertaken. The PRRS status of the herds was evaluated based on the analysis of blood samples by another serological test (blocking ELISA) capable of differentiating between infection with PRRSV of the American type and European type. The specificity of the indirect ELISA test on meat juice samples was 0.98. The sensitivity of the test depended on the type of the PRRSV strain involved. The apparent prevalence in herds infected with the American type of PRRSV was 0.44. The apparent prevalence in herds infected with the European type of PRRSV was 0.64. Herd level sampling and herd level criteria for assessing the PRRS status of herds by the new test were developed. Herds were classified as PRRS negative or PRRS seropositive based on 10 meat juice samples collected randomly at slaughter throughout a 3-month-period. Herd PRRS status classification by the indirect ELISA was validated in 47 herds by collection of blood samples from the herds. Eighteen herds were classified as PRRS negative by both test systems. Twenty-nine herds were classified as PRRS seropositive by both test systems. Acceptable herd classification was achieved using this test.

Designing serological surveillance programmes to document freedom from disease with special reference to exotic viral diseases of pigs in Denmark

Surveillance programmes based on laboratory screening tests are increasingly used to document freedom from disease in order to facilitate trade. The following aspects must be considered when designing such programmes: diseases to be selected; epidemiology of the diseases; unit of analysis (animal or herd); target age group (or target farm type); test characteristics and sample size. Issues related to these aspects are discussed and illustrated using the example of serological surveillance for exotic viral diseases in the pig population of Denmark. Sampling designs based on individual animal samples are compared with herd-based sampling (two-stage sampling). While the latter is likely to require a larger sample size, the increased level of information and the reliability of the results obtained are considered to be worth the expense. Issues related to the development of international standards for declaring freedom from disease are discussed. The authors conclude that international standards are desirable, providing that these standards represent scientifically valid principles.

Comparison of a partially hydrolyzed infant formula with two extensively hydrolyzed formulas for allergy prevention: a prospective, randomized study

The aim of this study was to compare the allergy-preventive effect of a partially hydrolyzed formula with two extensively hydrolyzed formulas, in infants with a high risk for development of allergic disease. High-risk infants from four Danish centres were included in the period from June 1994 to July 1995. Five-hundred and ninety-five high-risk infants were identified. High-risk infants were defined as having biparental atopy, or a single atopic first-degree relative combined with cord blood immunoglobulin E (IgE)> or =0.3 kU/l. At birth all infants were randomized to one of three different blinded formulas. All mothers had unrestricted diets during pregnancy and lactation and were encouraged to breast-feed exclusively. If breast-feeding was insufficient, one of the three formulas, according to randomization, was given during the first 4 months. It was recommended not to introduce cow's milk, cow's milk products. and solid foods until the age of 4 months. After the age of 4 months a normal unrestricted diet and conventional cow's milk-based formula were given when needed. All infants were followed-up prospectively with interview and physical examination at the age of 6, 12, and 18 months, and if any possible atopic symptoms were reported. If food allergy was suspected, controlled elimination/challenge procedures were performed in a hospital setting. Of 550 infants included in the study, 514 were seen at all visits and 36 were excluded owing to noncompliance. Of 478 infants who completed the study, 232 were exclusively breast-fed, 79 received an extensively hydrolyzed casein formula (Nutramigen), 82 an extensively hydrolyzed whey formula (Profylac), and 85 a partially hydrolyzed whey formula (Nan HA), during the first 4 months of life. These four groups were identical in regard to atopic predisposition, cord blood IgE, birthplace, and gender. Exclusively breast-fed children were exposed less to tobacco smoke and pets at home and belonged to higher social classes, whereas the three formula groups were identical concerning environmental factors. The frequency of breast-feeding was high; only eight (2%) children were not breast-fed at all. The three formula groups were identical in regard to duration of breast-feeding and age at introduction of formula and solid foods. No significant differences were found in the three groups of infants receiving formula milk regarding the cumulative incidence of atopic dermatitis or respiratory symptoms. The cumulative incidence of parental-reported cow's milk allergy was significantly higher in children fed partially hydrolyzed formula (Nan HA) compared with extensively hydrolyzed formula (Nutramigen or Profylac) at 12 and 18 months (NanHA, 7.1%; Nutramigen, 2.5%; Profylac, 0%; p=0.033). The cumulative incidence of confirmed cow's milk allergy was 1.3% (three of 232) in exclusively breast-fed infants, 0.6% (one of 161) in infants fed extensively hydrolyzed formula (Nutramigen or Profylac), and 4.7%(four of 85) in infants fed partially hydrolyzed formula (Nan HA). Partially hydrolyzed formula was found to be less effective than extensively hydrolyzed formula in preventing cow's milk allergy, 0.6% vs. 4.7% (p=0.05), but because of the small number of cases the results should be interpreted with caution. Compared with other similar studies the frequency ofatopic symptoms was low, even though the dietetic intervention did not include either maternal diet during lactation or dietary restrictions to the children after the age of 4 months.

Comparison of the Danish Prostatic Symptom Score with the International Prostatic Symptom Score, the Madsen-Iversen and Boyarsky symptom indexes. ALFECH Study Group

OBJECTIVE

To compare the Danish Prostatic Symptom Score (DAN-PSS) with the International Prostatic Symptom Score (IPSS). Madsen-Iversen and Boyarsky symptom indexes in a clinical setting, and to evaluate the potential significance of any differences in information obtained from these questionnaires.

PATIENTS AND METHODS

The study comprised two substudies: in the first, 205 patients with lower urinary tract symptoms (LUTS) suggestive of bladder outlet obstruction (BOO), a Madsen-Iversen score > 6 and a maximum flow rate of < 10 mL/s were randomized to receive either placebo or alfuzosin in a double-blind study of 16 weeks. The symptoms were assessed using the Madsen-Iversen, DAN-PSS and the IPSS questionnaires. In the second, 138 patients with LUTS suggestive of BOO were selected for treatment with transurethral microwave thermotherapy (TUMT, 52 degrees C for 60 min, microwave energy 200 kJ) and their symptoms assessed using the Boyarsky and the DAN-PSS questionnaires. Patients were then followed for one year. Rank correlation coefficients and regression lines were calculated using Spearman's non-parametric test. The relative changes, i.e. responsiveness, calculated for the DAN-PSS, IPSS and Boyarsky indexes were compared pairwise using the Wilcoxon-Pratt test.

RESULTS

The DAN-PSS, IPSS and Madsen-Iversen indexes were correlated on a pairwise basis. The DAN-PSS and IPSS indexes have significant construct validity in terms of correlation with the Madsen-Iversen system (Spearman's correlation coefficient, rs = 0.51 and rs = 0.45, respectively). The DAN-PSS and the IPSS indexes were correlated (rs = 0.61). The DAN-PSS was more sensitive than the IPSS to changes after pharmacological treatment, with scores decreasing 70% and 29% (P < 0.05), respectively, after treatment with an alpha-blocker for 4 months, and 50% and 29% (P < 0.05), respectively, after 4 months on placebo treatment. Finally, the responsiveness of the Boyarsky and DAN-PSS indexes to TUMT showed that the DAN-PSS system was significantly more responsive than the Boyarsky index, with scores decreasing 57% and 15% (P < 0.05), respectively, after one year.

CONCLUSIONS

The DAN-PSS index is more sensitive than the IPSS, Madsen-Iversen and Boyarsky symptom indexes, incorporates important outcome events, includes a patient-weighting of each symptom, thereby reflecting better the patients' global assessment of outcome.

Epididymo-orchitis and Reiter's disease. Two infrequent complications after intravesical bacillus Calmette-Guérin therapy

Two cases of adverse reactions to intravesical treatment with bacillus Calmette-Guérin are reported. The first patient presented with a severe suppurating epididymo-orchitis three months after his last treatment. The second patient developed Reiter's disease with arthritis of one knee and conjunctivitis 1 week after the fourth instillation.

A case-control questionnaire survey of risk factors for porcine reproductive and respiratory syndrome (PRRS) seropositivity in Danish swine herds

Sixty-eight case herds seropositive to porcine reproductive and respiratory syndrome (PRRS) were compared to 128 seronegative controls in a double-blinded questionnaire survey. The study indicated no increased risk of PRRS seropositivity for herds using artificial insemination with semen from PRRS seropositive AI-stations. Also the herd-size was non-related to the risk of PRRS seropositivity, indicating that air-borne spread of PRRS may not have been a predominant feature in Denmark. Introduction of replacement breeding animals from seropostive breeding- and multiplying herds significantly increased the risk of a herd being PRRS seropositive, as did introduction of 25 kg pigs for feeding. PRRS seropositivity was in the farmers' opinions associated with abortions in sows, early farrowing, high postweaning mortality and low weight gain in fattening pigs. However, the reported frequencies of probelms were relatively low.

Clinical effects of anticoagulant therapy in suspected acute myocardial infarction: systematic overview of randomised trials

OBJECTIVES

Most randomised trials of anticoagulant therapy for suspected acute myocardial infarction have been small and, in some, aspirin and fibrinolytic therapy were not used routinely. A systematic overview (meta-analysis) of their results is needed, in particular to assess the clinical effects of adding heparin to aspirin.

DESIGN

Computer aided searches, scrutiny of reference lists, and inquiry of investigators and companies were used to identify potentially eligible studies. On central review, 26 studies were found to involve unconfounded randomised comparisons of anticoagulant therapy versus control in suspected acute myocardial infarction. Additional information on study design and outcome was sought by correspondence with study investigators.

SUBJECTS

Patients with suspected acute myocardial infarction.

INTERVENTIONS

No routine aspirin was used among about 5000 patients in 21 trials (including half of one small trial) that assessed heparin alone or heparin plus oral anticoagulants, and aspirin was used routinely among 68,000 patients in six trials (including the other half of one small trial) that assessed the addition of intravenous or high dose subcutaneous heparin.

MAIN OUTCOME MEASUREMENTS

Death, reinfarction, stroke, pulmonary embolism, and major bleeds (average follow up of about 10 days).

RESULTS

In the absence of aspirin, anticoagulant therapy reduced mortality by 25% (SD 8%; 95% confidence interval 10% to 38%; 2P = 0.002), representing 35 (11) fewer deaths per 1000. There were also 10 (4) fewer strokes per 1000 (2P = 0.01), 19 (5) fewer pulmonary emboli per 1000 (2P < 0.001), and non-significantly fewer reinfarctions, with about 13 (5) extra major bleeds per 1000 (2P = 0.01). Similar sized effects were seen with the different anticoagulant regimens studied. In the presence of aspirin, however, heparin reduced mortality by only 6% (SD 3%; 0% to 10%; 2P = 0.03), representing just 5 (2) fewer deaths per 1000. There were 3 (1.3) fewer reinfarctions per 1000 (2P = 0.04) and 1 (0.5) fewer pulmonary emboli per 1000 (2P = 0.01), but there was a small non-significant excess of stroke and a definite excess of 3 (1) major bleeds per 1000 (2P < 0.0001).

CONCLUSIONS

The clinical evidence from randomised trials dose not justify the routine addition of either intravenous or subcutaneous heparin to aspirin in the treatment of acute myocardial infarction (irrespective of whether any type of fibrinolytic therapy is used).

Symptomatic outcome of transurethral prostatectomy, alpha-blockade and placebo in the treatment of benign prostatic hyperplasia. Evaluation of treatment with the Danish Prostatic Symptom Score (DAN-PSS-1) system. The ALFECH Study Group

To assess the symptomatic outcome following transurethral prostatectomy (TURP), alpha-blockade and placebo treatment in uncomplicated benign prostatic hyperplasia (BPH), 260 patients were evaluated with the recently formulated Danish Prostatic Symptom Score (DAN-PSS-1) system: 205 were randomized to either the selective alpha-blocker alfuzosin or placebo and 55 underwent TURP. Following TURP, the DAN-PSS-1 score was reduced by 80% after 6-10 weeks (visit 2) and by 100% after 12-16 weeks (visit 3). In the alfuzosin group the corresponding reductions were 40% and 65% (p < 0.02 vs. placebo). In the placebo group the reduction was 25% at visit 2, with no further fall demonstrated thereafter. During alfuzosin treatment the bother score (impact of symptoms on quality of life) fell more than the symptom score. During placebo treatment there was no reduction in symptom score. We conclude that the DAN-PSS-1 questionnaire sensitively identifies clinically important responses to treatment of BPH.

The symptomatic outcome of transurethral prostatectomy evaluated with the DAN-PSS-1 score system

We assessed the symptomatic outcome of transurethral prostatectomy with the newly developed self-administered questionnaire, Danish Prostate Symptom Score (DAN-PSS-1), in men suffering from uncomplicated benign prostatic hyperplasia (BPH). The questionnaire was filled in adequately by 53 men, median age 69 (range 52-82), preoperatively and 2, 4 and 6 months after transurethral prostatectomy (TUR-P). The DAN-PSS-1 symptom score showed a high degree of sensitivity as the preoperative total score was median 20 (quartiles 14-36) and decreased to 4, 0 and 1 (quartiles from 0-4) at the 2, 4, and 6-month control respectively. The symptoms related to voiding were relieved totally after 2 months while symptoms related to storage were first relieved completely at 4-month control. Bother from symptoms was relieved after 2 months, although some symptoms still remained. The questionnaire was internally consistent with a reliability coefficient, Cronbach's alpha (alphaCr), of 0.73. We conclude that the DAN-PSS-1 questionnaire is an efficient tool among others in the indication and evaluation of treatment of uncomplicated BPH.

Assessment of lower urinary tract symptoms in women by a self-administered questionnaire: test-retest reliability

A self-administered questionnaire assessing female lower urinary tract symptoms and their impact on quality of life is described and validated, on 56 females in six participating departments. The patients answered two identical questionnaires on separate occasions before treatment. Test-retest reliability of the questionnaire, correlation between the symptoms and their troublesomeness, and the reproducibility of this correlation were assessed. The percentage of mistakes in answers to each of the questions varied from 1.8% to 49.1%, mainly owing to missing answers in the item groups: appliances, sexual function and social activities. Test-retest showed a repeat frequency of 50.0%-91.0% for symptoms and 44.6%-82.1% for trouble. A highly significant positive correlation was found between symptoms and trouble, which was most pronounced for questions concerning pain and incontinence. This correlation was consistent within time. The primary validation of this questionnaire is good. Its relevance as a basis for medical priority and clinical decision making remains to be investigated.

Validation of the self-administered Danish Prostatic Symptom Score (DAN-PSS-1) system for use in benign prostatic hyperplasia

OBJECTIVE

To validate the Danish Prostatic Symptom Score (DAN-PSS-1), a self-administered quality-of-life questionnaire comprising 12 questions related to voiding problems and the perceived bother of each individual symptom.

METHODS

Using published results from several comparisons of other symptom scoring systems with DAN-PSS-1, the test-retest reliability, internal consistency, construct and content validity, and responsiveness of the DAN-PSS-1 system were assessed.

RESULTS

The system was internally consistent (Cronbach's alpha = 0.73), the median test-retest reliability of answers to each question was 83.5% (range 0-99.7%) and the questionnaire was well understood by the patients. The DAN-PSS-1 system demonstrated a high degree of construct validity, correlating with the extensively used Madsen-Iversen score system (Spearman's correlation coefficient, rs = 0.51) and with the patients' answers to questions about how bothersome their symptoms were (rs = 0.71). The DAN-PSS-1 system discriminated clearly between patients with benign prostatic hyperplasia (BPH) and control subjects (an area under the receiver operating characteristic curve of 0.94). Finally, the DAN-PSS-1 was sensitive to changes following intervention, with scores decreasing from a median of 20 to zero 4 months after patients underwent transurethral prostatectomy and from a median of 11.5 to 7.5 (65%) after patients had received 4 months treatment with an alpha-blocker.

CONCLUSIONS

The DAN-PSS-1 system is reliable, valid and responsive, and therefore can be recommended for assessing the severity of symptoms among patients presenting with lower urinary tract complaints suggestive of BPH and in the follow-up after intervention.

[Pseudocroup treated with inhaled steroid (budesonide). A double-blind placebo-controlled trial]

The aim of this prospective, randomised, double blind study was to evaluate whether inhaled nebulized corticosteroid is effective in the treatment of croup. Thirty-seven children (aged 0.4-4.9 years) admitted to hospital with moderate to severe croup were allocated to treatment with either 2 mg nebulized budesonide (20) or saline (17). Disease severity was assessed by a clinical croup score based on stridor, cough, retractions, dyspnoea and cyanosis, and the overall clinical assessment was scored on a visual log scale (0-100). Two hours after treatment there was a significant improvement in croup score in the group treated with budesonide (8 to 4.5), but not in the group treated with saline (8 to 8). Furthermore, the overall clinical assessment score decreased significantly (50 to 25) in the group treated with budesonide, whereas it remained constant in the placebo group (60 to 62). The results indicate that nebulised budesonide can be used as a safe and effective alternative treatment in children with moderate to severe croup.

Characterization of pressure changes in the lower urinary tract during coughing with special reference to the demands on the pressure recording equipment

The exact demands on urodynamic equipment for measurement of coughs and cough associated pressure changes in the lower urinary tract have been analyzed from high-speed pressure recordings using a double microtip transducer and a storage oscilloscope. The equipment was tested in vitro by the step-test method. The natural frequency response was 175.6 Hz and the rise-time 2.5 ms, resulting in accurate measurements of frequencies up to about 60 Hz, which is way above the clinically measured frequencies. Four men and 2 women, all of whom were healthy volunteers, were examined in the supine position with an empty bladder. Pressures were measured in the bladder and in the external sphincter zone of the urethra. The spectral power density of the bladder and urethral pressures were calculated by Fourier analysis. The pressure changes in the urethra were in all volunteers equal to or slower than in the bladder. The analysis of the spectral power density showed that 99% of the pressure changes could be recorded with an instrument capable of recording 9 Hz frequencies, i.e., with a sampling rate of 18 Hz or more.

Further evidence of long distance airborne transmission of Aujeszky's disease (pseudorabies) virus

In spite of the eradication of Aujeszky's disease in Denmark a single outbreak was recorded in December 1988 and another severe epizootic took place during the winter and spring of 1989/90. The epizootic occurred in nearly the same areas as the preceding epizootic during the winter of 1987/88. Identification of the strains of virus involved eliminated the possibility that the latest epizootic was due to the persistence of virus in the pig population. Furthermore, as during the preceding epizootic, initial recordings of the new strains were found to coincide with periods with southerly winds. It was concluded from circumstantial evidence that the concurrent introductions of virus to several farms played a major role during the epizootic.

Treatment of croup with nebulised steroid (budesonide): a double blind, placebo controlled study

The aim of this prospective, randomised, double blind study was to evaluate whether nebulised local steroid treatment is effective in the treatment of croup. Thirty six infants and children (0.4-4.9 years of age) admitted to hospital with moderate to severe croup were allocated to receive either 2 mg nebulised budesonide (20 children) or saline (16 children). Disease severity was assessed by a clinical total croup score based on stridor, cough, retractions, dyspnoea, and cyanosis. In addition the overall clinical impression was evaluated (0-100). Two hours after treatment there was a significant improvement in the total croup score in the group treated with budesonide (8 to 4.5), but not in the group treated with saline (8 to 8). Furthermore, the overall clinical impression assessment score decreased significantly (50 to 25) in the group treated with budesonide, whereas it remained constant in the placebo group (60 to 62). The total croup score and overall clinical severity were significantly better in the group treated with budesonide than in the placebo group. No side effects were observed. The results indicate that nebulised budesonide can be used as a safe and effective alternative treatment in children and infants with moderate to severe croup.

Use of different inhalation devices in children

Many studies in which patient's inhaler use technique has been studied have shown that one of the major problems patients have, in using an inhaler correctly, is that of poor coordination of inhaler actuation with inspiration. We have studied a new breath-actuated inhaler ("Autohaler" 3M Riker) which is designed to ensure correct coordination automatically. This study involves 100 children (aged 3-10 years) and includes both normal children and asthmatic patients. None of these children have previous experience using any type of inhaler. Each child is taught to use the "Autohaler" containing a placebo only. A video film is employed in order to standardize the teaching technique. Once the child is able to operate the new inhaler correctly, he or she inspires through an "Autohaler" unit specially modified so that the inspiratory flow rate and the volume of air inhaled is measured by a pneumotachograph in series with the inhaler. The time point, within the inspiratory cycle, at which the inhaler is triggered is also recorded. The majority of children older than 7 years were able to use the "Autohaler" after a few minutes instruction. Therefore, this is a valuable alternative in this age group.

Evidence of long distance airborne transmission of Aujeszky's disease (pseudorabies) virus

Aujeszky's disease has been the subject of an eradication campaign in Denmark since 1980. A detailed knowledge of the virus strains present in the country was provided by restriction fragment analyses of older clinical isolates, and of isolates from all the virologically confirmed outbreaks since 1985. The introduction of foreign strains into southern border areas was demonstrated during the winters of 1984/85, 1986/87 and 1987/88. An epizootic during the winter of 1987/88 was shown to correlate with an unusual predominance of southerly winds. Both conventional and specific pathogen free herds became infected. A herd level case-control analysis of the outbreaks during the winter of 1987/88 revealed that there was a positive correlation between the risk of infection and the size of the herd. The observations support the hypothesis of airborne transmission of the disease.