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Chloride ingress profiles do almost always have a peak at some depth but most prediction models are missing this peak. Some prediction models, such as the fib model, simply “cut off” a slice of the concrete up to the peak in further predictions. Other prediction models use data only from the profiles beyond the peak but include the concrete up to the peak as if it has the same properties as the rest of the concrete. A physical model has been developed to quantify the local changes because of leaching and the consequences of these changes with time. The model uses Fick’s 1st law for chloride diffusion and linear chloride binding. The depth of leaching with time is modelled with a simple square-root equation. The consequences of leaching are assumed to be linear from the surface into the maximum depth of leaching. The consequences of leaching are modelled as depth-dependent changes of porosity, chloride binding and the diffusion coefficient in Fick’s first law.

Traditional methods for measuring moisture transport properties of concrete are time-consuming, especially since thick specimens are required, and steady-state methods are preferred. Non-steady state methods may be an alternative but the conditioning to uniform initial conditions is extremely difficult. The tin can method is, however, a good alternative under certain conditions and for certain concretes. Concrete is poured into a tin can and sealed cured in this way for at least a month. The can is opened, and the concrete is dried in a constant climate. Weight changes are recorded for several weeks. From these weight changes, the initial RH at start of drying, the drying climate and the desorption isotherm, the moisture transport coefficient or the moisture diffusion resistance factor are derived. The paper describes the theory behind the method and the unique conditions available for certain concretes that makes the method applicable. Examples of measurements are shown for a number of concretes and verification is done with the cup method on the very same concretes, with excellent results.

Flooring materials and adhesives can be degraded by high pH moisture from e.g. concrete. One way to avoid this degradation, is to dry the concrete and the screed to a sufficient moisture state prior to application of the flooring material. One way to evaluate the moisture state in the materials sensitive to high pH moisture is to calculate the redistribution of moisture in the flooring system from application and onwards. The calculations require substantial knowledge in both moisture related material properties and mass transport calculations in porous materials. The availability of more user-friendly calculations tools stresses the need for a common methodology for both performance and documentation of the calculations. Several input parameters are needed for the calculation, such as boundary conditions, initial moisture distribution and material properties. The most important material properties are the water vapor sorption isotherms (desorption, absorption and scanning) and moisture transport coefficients. This study is investigating the sensitivity of the moisture redistribution calculations to different input parameters, and assumptions needed for the calculation. It is also clarifying what relative humidity intervals that are relevant for different materials in the system and identifying a required accuracy in the different material properties. A first part of round-robin studies with selected cases has been performed to evaluate difference between calculations tools and users.

Abstract Background The transcription factors CCAAT/enhancer binding proteins (C/EBP) α, β and δ have been shown to be expressed in brain and to be involved in regulation of inflammatory genes in concert with nuclear factor κB (NF-κB). In general, C/EBPα is down-regulated, whereas both C/EBPβ and δ are up-regulated in response to inflammatory stimuli. In Alzheimer's disease (AD) one of the hallmarks is chronic neuroinflammation mediated by astrocytes and microglial cells, most likely induced by the formation of amyloid-β (Aβ) deposits. The inflammatory response in AD has been ascribed both beneficial and detrimental roles. It is therefore important to delineate the inflammatory mediators and signaling pathways affected by Aβ deposits with the aim of defining new therapeutic targets. Methods Here we have investigated the effects of Aβ on expression of C/EBP family members with a focus on C/EBPδ in rat primary astro-microglial cultures and in a transgenic mouse model with high levels of fibrillar Aβ deposits (tg-ArcSwe) by western blot analysis. Effects on DNA binding activity were analyzed by electrophoretic mobility shift assay. Cross-talk between C/EBPδ and NF-κB was investigated by analyzing binding to a κB site using a biotin streptavidin-agarose pull-down assay. Results We show that exposure to fibril-enriched, but not oligomer-enriched, preparations of Aβ inhibit up-regulation of C/EBPδ expression in interleukin-1β-activated glial cultures. Furthermore, we observed that, in aged transgenic mice, C/EBPα was significantly down-regulated and C/EBPβ was significantly up-regulated. C/EBPδ, on the other hand, was selectively down-regulated in the forebrain, a part of the brain showing high levels of fibrillar Aβ deposits. In contrast, no difference in expression levels of C/EBPδ between wild type and transgenic mice was detected in the relatively spared hindbrain. Finally, we show that interleukin-1β-induced C/EBPδ DNA binding activity to both C/EBP and κB sites is abolished after exposure to Aβ. Conclusions These data suggest that both expression and function of C/EBPδ are dysregulated in Alzheimer's disease. C/EBPδ seems to be differently regulated in response to different conformations of Aβ. We propose that Aβ induces an imbalance between NF-κB and C/EBP transcription factors that may result in abnormal responses to inflammatory stimuli.

Abstract Background Protein aggregation plays important roles in several neurodegenerative disorders. For instance, insoluble aggregates of phosphorylated tau and of Aβ peptides are cornerstones in the pathology of Alzheimer's disease. Soluble protein aggregates are therefore potential diagnostic and prognostic biomarkers for their cognate disorders. Detection of the aggregated species requires sensitive tools that efficiently discriminate them from monomers of the same proteins. Here we have established a proximity ligation assay (PLA) for specific and sensitive detection of Aβ protofibrils via simultaneous recognition of three identical determinants present in the aggregates. PLA is a versatile technology in which the requirement for multiple target recognitions is combined with the ability to translate signals from detected target molecules to amplifiable DNA strands, providing very high specificity and sensitivity. Results For specific detection of Aβ protofibrils we have used a monoclonal antibody, mAb158, selective for Aβ protofibrils in a modified PLA, where the same monoclonal antibody was used for the three classes of affinity reagents required in the assay. These reagents were used for detection of soluble Aβ aggregates in solid-phase reactions, allowing detection of just 0.1 pg/ml Aβ protofibrils, and with a dynamic range greater than six orders of magnitude. Compared to a sandwich ELISA setup of the same antibody the PLA increases the sensitivity of the Aβ protofibril detection by up to 25-fold. The assay was used to measure soluble Aβ aggregates in brain homogenates from mice transgenic for a human allele predisposing to Aβ aggregation. Conclusions The proximity ligation assay is a versatile analytical technology for proteins, which can provide highly sensitive and specific detection of Aβ aggregates - and by implication other protein aggregates of relevance in Alzheimer's disease and other neurodegenerative disorders.

Abstract Background Previous research shows that surgeon-performed ultrasound for patients presenting with abdominal pain in the emergency department leads both to higher diagnostic accuracy and to other benefits. We have evaluated the level of patient satisfaction, health condition and further health care consumption after discharge from the emergency department. Methods A total of 800 patients who attended the emergency department for abdominal pain were randomized to surgeon-performed ultrasound or not as a complement to standard examination. All patients were interviewed by telephone six weeks after the visit to the emergency department using a structured questionnaire including information about health condition, satisfaction and medical examinations. A regional health register was used to check health care consumption over two years and mortality was checked for in the personal data register. Results We found a higher self-rated patient satisfaction in the ultrasound group when leaving the emergency department. After six weeks the figures were equal. There were fewer patients in the ultrasound group with completed or planned complementary examinations after six weeks (31.1%) compared with the control group (41.4%), p = 0.004. There was no difference found in the two-year health care consumption or mortality between the groups. Conclusion For patients with acute abdominal pain, bedside ultrasound examination is related to higher satisfaction and decreased short-term health care consumption. No major effects were revealed when evaluating effects on a long-term basis, including mortality. The previously proven benefit together with the lack of adverse effects from the method makes ultrasound well worth considering for implementation in emergency departments. Trial registration The study has been registered in ClinicalTrials.gov ID NCT00550511.

Background and Aims: Plant-pollinator interactions are thought to have shaped much of floral evolution. Yet the relative importance of pollinator shifts and coevolutionary interactions for among-population variation in floral traits in animal-pollinated species is poorly known. This study examined the adaptive significance of spur length in the moth-pollinated orchid Platanthera bifolia., Methods: Geographical variation in the length of the floral spur of P. bifolia was documented in relation to variation in the pollinator fauna across Scandinavia, and a reciprocal translocation experiment was conducted in south-east Sweden between a long-spurred woodland population and a short-spurred grassland population., Key Results: Spur length and pollinator fauna varied among regions and habitats, and spur length was positively correlated with the proboscis length of local pollinators. In the reciprocal translocation experiment, long-spurred woodland plants had higher pollination success than short-spurred grassland plants at the woodland site, while no significant difference was observed at the grassland site., Conclusions: The results are consistent with the hypothesis that optimal floral phenotype varies with the morphology of the local pollinators, and that the evolution of spur length in P. bifolia has been largely driven by pollinator shifts.

Prolactin is best known for its involvement in lactation, where it regulates mechanisms that supply nutrients for milk production. In individuals with pathological hyperprolactinemia, glucose and fat homeostasis have been reported to be negatively influenced. It is not previously known, however, whether prolactin regulates lipogenesis in human adipose tissue. The aim of this study was to investigate the effect of prolactin on lipogenesis in human adipose tissue in vitro. Prolactin decreased the concentration of malonyl-CoA, the product of the first committed step in lipogenesis, to 77+/-6% compared to control 100+/-5% (p=0.022) in cultured human adipose tissue. In addition, prolactin was found to decrease glucose transporter 4 ( GLUT4) mRNA expression, which may cause decreased glucose uptake. In conclusion, we propose that prolactin decreases lipogenesis in human adipose tissue as a consequence of suppressed malonyl-CoA concentration in parallel with decreased GLUT-4 expression. In the lactating woman, this regulation in adipose tissue may enhance the provision of nutrients for the infant instead of nutrients being stored in adipose tissue. In hyperprolactinemic individuals, a suppressed lipogenesis could contribute to an insulin resistant state with consequences for the health., (Georg Thieme Verlag KG Stuttgart.New York.)

Background: We have recently found a correlation between contact allergy to gold sodium thiosulphate (GSTS) and gold concentration in the blood (B-Au) in a stented population: the higher the B-Au, the stronger the patch-test reaction., Objectives: To further investigate the correlation between B-Au and patch-test reactivity to gold., Methods: In this provocation control cross-over trial of 24 patients with dermatitis with a known contact allergy to gold, the patients were randomized into two groups where one was topically provoked to gold (15 mg GSTS) and one to the control. All patients were simultaneously patch tested with GSTS in 10 aqueous dilutions (1.1 mg GSTS). Patch-test readings were performed and blood was drawn. After 6 weeks, the experiment was repeated and the group that had previously been provoked with gold was now provoked with the control and vice versa., Results: B-Au was higher after gold provocation whereas no treatment effect was discerned for minimal eliciting concentration (MEC) or summarized test score (STS). Instead, significant differences in period effect were observed implying higher B-Au and STS and lower MEC on test occasion II. The most likely explanation is the increased B-Au and /or booster effect from test occasion I. There was a correlation between B-Au and MEC: the higher the B-Au, the lower the MEC., Conclusions: The correlation between B-Au and MEC indicates that the B-Au is of importance for the skin reactivity to gold.

Organ-specific homing of lymphoid cells depends on the expression of tissue-specific adhesion molecules and production of specific chemokines. CCL25 (TECK) and CCL28 (MEC) have been reported to direct circulating memory/effector B cells to mucosal tissues. Here, we examined if differential responsiveness to mucosal and systemic chemokines could explain the differential migration pattern of circulating human antibody-secreting cells (ASC), induced by mucosal and systemic immunization. There was a robust migration of specific IgA- and IgM-ASC induced by Salmonella vaccination toward the mucosal chemokines CCL25 and CCL28. In contrast, tetanus-specific ASC migrated to the systemic chemokine CXCL12 (SDF-1alpha) and showed no response to CCL25 or CCL28, not even tetanus-specific IgA-ASC. Cell sorting experiments demonstrated that Salmonella-specific ASC co-expressed CCR9 and CCR10. Our results show that induction site, rather than isotype commitment, determines the chemokine responsiveness and migration pattern of human effector B cells.

We have previously reported that there is an immunological cross-reactivity between Schistosoma mansoni and cholera toxin (CT). In this study, using an immunofluorescence technique with anti-CT antibody, we provide further evidence for this cross-reactivity by demonstrating an antigen, localized in the tegument of S. mansoni adult worms which is cross-reactive with a CT antigen. Anti-CT antibodies also reacted with structures in S. mansoni cercariae and eggs. Additionally, CT itself was found to bind strongly to the gut of the adult worm, gut cells of cercaria and the egg shell. The binding of CT to the parasite was blocked when parasite sections were incubated with CT which had been incubated with the ganglioside GM1. Lipid extraction and isolation of gangliosides demonstrated the presence of GM1 in adult worms. For further analysis of CT-binding structures, the possible interaction of CT with two major schistosome gut antigens, circulating cathodic antigen (CCA) and circulating anodic antigen (CAA), was studied. We found that CT blocked the binding of anti-CCA antibody to the gut of adult worms and that anti-CCA blocked the binding of CT to the worm gut. These findings indicate that CT binds to CCA present in the gut of the parasite and thus has, in addition to GM1, a second binding specificity.

Coeliac disease (CD) is known to have a strong genetic background. We analyzed the association between serological markers of CD and the -1087 IL10 and -308 TNFA gene polymorphisms in Swedish patients. A higher frequency of the TNF2 allele was present in the patients compared with the controls (p < 0.0001). The frequency of the AA genotype of the IL10 gene in the patients was unexpectedly higher in comparison with the controls (p < 0.05). The levels of IgA anti-endomysium and antitissue transglutaminase antibodies were associated with IL10 but not with TNFA genotype. The patients with the AA or GG -1087 IL10 genotypes had significantly lower levels of antibodies in comparison with those with the AG genotype (p < 0.05 to p < 0.0005). However, when divided according to potential level of IL-10 production, the group of potentially high IL-10 producers among the CD patients demonstrated significantly lower levels of antitissue transglutaminase antibodies compared to potentially low IL-10 producers (p = 0.01). Our results show a relationship between the levels of IgA antibodies involved in CD with the IL10 genotypes. This suggests a possible involvement of IL-10 in the development of the disease.

Objective: The aim of the present study was to investigate whether adult patients with coeliac disease in remission could include large amounts of oats in their daily gluten-free diet for an extended period of time without adverse effects., Design, Subjects and Methods: Twenty adult coeliac patients in remission included large amounts of uncontaminated rolled oats in their daily diet for a prolonged period. The examinations, performed four times during the study period, included small bowel endoscopy with biopsies, blood samples (nutritional status, serological analysis), height and body weight, gastrointestinal symptoms and dietary records. Gastrointestinal symptoms and diet were also investigated through unannounced telephone interviews once a month during the study period., Results: No adverse effects of a large intake of oats were seen in small bowel histology, serology nor in nutritional status in the 15 subjects who completed the whole study period. Two of the subjects dropped out because of gastrointestinal symptoms and three for non-medical reasons. The median intake of oats was 93 g/day and the compliance to the oat diet was found to be good. Examinations of the patients after drop-out did not show any deterioration in small bowel histology or nutritional status nor raised levels of antibodies., Conclusion: Results from this study indicate that adult patients with coeliac disease in remission can include large amounts of controlled wheat-free rolled oats for an extended period of time without adverse effects.

The fibre-web technique for sampling, storing and transport of venous or capillary blood has been evaluated, in 84 schoolchildren from the Mwanza region of Tanzania, with regard to diagnostic efficacy for determination of the schistosome circulating anodic antigen (CAA) under conditions similar to those prevailing in the field. Although the average concentrations determined in fibre-web eluates were only about half of those determined in serum, the prevalences of CAA-positive individuals for the 2 sample materials were approximately the same. The average coefficient of variation calculated on determination of CAA in venous-blood fibre-web eluates amounted to 7%. The study shows that the fibre-web technique is well suited for use under field conditions.

Patients with malabsorption and histological findings consistent with celiac disease, who are unresponsive to gluten free diet, and in whom other causes of flat mucosa have been excluded, are considered to suffer from so called unclassified or refractory sprue. Although the true nature of this condition needs to be further elucidated, it is known to represent a difficult therapeutical problem with potentially fatal course. Herein, we report a patient with refractory sprue-like disease who after failing to respond to corticosteroids and TPN was in a critical condition. He responded promptly to cyclosporine and made a remarkable recovery. In contrast to previous reports, the cyclosporine treatment in this patient was pursued only for 1 month, whereupon the patient turned responsive to steroids. Subsequent treatment with azathioprine allowed corticosteroids to be reduced to a low maintenance dose and eventually all drugs could be discontinued without reappearance of symptoms. Cyclosporine therapy might be lifesaving in occasional patients with refractory sprue-like disease and it may result in reversal of steroid resistance. Moreover, azathioprine seems to have a steroid sparing effect in this setting. Short term immunosuppressive treatment may have an advantage of lower risk for drug related side effects.

Intranasal administration of schistosome antigens in combination with appropriate adjuvant may be an effective route for immunization against schistosomes, since the lungs represent an important site of elimination of schistosomulae. Our previous studies have shown that in mice intranasal administration of cholera toxin (CT) before infection with Schistosoma mansoni results in an enhancement of the worm burden in comparison to nontreated infected animals. In the present study, it was shown that mice treated intranasally with CT displayed high numbers of schistosome-reactive IgM-secreting cells in the spleen as well as high levels of schistosome-reactive serum IgM antibodies, whereas no significant immunological response against two other antigens, ovalbumin (OVA) or keyhole limpet haemocyanin (KLH) was noted. Sera from mice treated intranasally with CT recognized a 22 kDA antigen on SWAP blots. This band was not demonstrable after absorption of the sera with SWAP. These findings indicate a possible cross reactivity between cholera toxin and schistosome antigens. Further analysis by Western blot revealed that a 22 kDa antigen was detected on CT blots by sera from mice and humans infected with S. mansoni. This band was not demonstrable after absorption of the mouse or the human sera with CT. The 22 kDa cross reactive antigen was heat-stable. The antibodies against the 22 kDa antigen were only found within the IgM class but not within other Ig isotypes. Our findings also indicate that the 22 kDa antigen detected by anti-S. mansoni antibodies represents the A1 fragment of the cholera toxin.

Blood sampling on filter paper is widely used for immunodiagnostic and epidemiological purposes. However, elution of conventional filter papers impregnated with sera containing Schistosoma mansoni circulating anodic antigen (CAA) recovered only a small fraction of the antigen, thereby reducing the sensitivity of the assay. Polypropylene-based non-woven fibre web is a new sampling material with a low density of fibres and with a small surface area of contact. When it was impregnated with serum containing CAA, approximately 90% of the antigen could be extracted. The yield of antibodies against S. mansoni from the new sampling material did not differ from that from conventional filter papers.

Mice immunized with soluble adult worm antigen (SWAP) in combination with cholera toxin (CT) displayed significantly larger numbers of IgG1, IgM and IgA secreting cells in the spleen and in the lungs as compared to mice which had received SWAP only. The ratio of SWAP-specific IgG1 to IgG2a antibody-secreting spleen cells was also significantly higher in the SWAP-CT group. Analysis of cytokine responses revealed that SWAP-stimulated spleen and lung cells from the SWAP-CT group produced lower levels of IFN-gamma but higher levels of IL-4 and IL-5 as compared to cells from the SWAP group. These findings indicate that intranasal administration of SWAP-CT induces a Th2 cell response in the spleen and in the lungs. Our findings also suggest that CT was responsible for induction of this Th2 cell response, since intranasal administration of SWAP alone induced a Th1 type response in the spleen and in the lungs.

Based on assumptions about the pathophysiology of egg-related lesions in the lower reproductive tract, putative indirect disease markers were investigated in vaginal fluids from 54 Malawi adolescent girls and women infected with S. haematobium. These women received a careful gynecological examination during which biopsies were taken from the cervix, and, if present, also from suspicious lesions in the vagina and the vulva. If the biopsies, either in wet crushed preparations or in histological sections, contained eggs the patients were considered to have female genital schistosomiasis (FGS; n = 33). The remainder (n = 21) were classified as having urinary schistosomiasis only. Eosinophil cationic protein (ECP), a cytotoxic granule protein of eosinophils, neopterin, a second messenger molecule generated during the activation of macrophages, and IgA as an indicator of local B-cell activation were quantitatively determined in vaginal fluid. To clarify the origin of ECP, this protein was also looked for in histological sections by an immunohistochemical method. In order to explore whether such disease markers can be detected after absorption to a tampon-like material, ECP and IgA were also assessed after elution from a non-porous, polypropylene fibre web impregnated with vaginal fluid. The concentration of ECP in vaginal fluid and the degree of immunohistochemical staining in histological sections were significantly higher in patients with FGS than in women with urinary schistosomiasis only. The amount of ECP detected in histological sections correlated to the number of eggs/mm2 of compressed genital tissue (rho = 0.36, P = 0.02), and the concentration of ECP in vaginal fluid correlated to the concentration of neopterin as well as to that of IgA (rho = 0.52, P = 0.004 and rho = 0.37, P = 0.02, respectively). Median neopterin concentration in vaginal fluid was also higher in the FGS group, but the difference was not statistically significant. ECP could also be detected in eluates from impregnated fibre webs, but the concentration was approximately one power of 10 less than in the original vaginal fluid. These results demonstrate that indicators of immunological mechanisms related to the egg-granuloma might be useful as indirect disease markers for women with FGS if assessed in vaginal washings or swab eluates.

A baseline study to evaluate the prevalence of Schistosoma mansoni infection as well as the diagnostic efficacy of serodiagnostic tests was performed in Kabaganga village, Kome island, Lake Victoria, Tanzania. A total of 1108 individuals were examined parasitologically and clinically. Egg excretion was demonstrated by one-sample Kato-Katz test. Specific IgG1 and IgG4 antibodies against S. mansoni adult worm (SAWA) and egg (SEA) antigens as well as circulating anodic antigen (CAA) were determined in serum samples from 250 of these subjects. As a control population 41 individuals from a non-endemic area were examined parasitologically, clinically and serologically. In the parasitologically examined Kabaganga population 45% were excreting eggs. The pattern of egg excretion was typical for an endemic area with a peak in the age group 10-14 years. Sixty-five percent of the serologically tested villagers were positive in the CAA test. A total of 80% were positive in either of the two tests, indicating an active infection. In 67-95% of these individuals the levels of isotype specific antibodies were increased. The prevalence of CAA positivity corresponded fairly well with that of Kato-Katz results in the age groups 10-29 years, but in the younger age groups a considerably greater number of individuals were positive in the CAA test than in the Kato-Katz test. The results obtained indicate that virtually all of the Kabaganga villagers, regardless of age, had an ongoing, active infection or had previously been infected with S. mansoni. This population, therefore, may be useful for evaluation of the diagnostic efficacy of various antibody tests. The highest degree of discrimination between the endemic and the non-endemic village populations was noted for anti-egg IgG4 antibodies. It is concluded that the combined determination of parasite eggs in faeces and CAA in serum provides high sensitivity as regards active infection. Increased levels of isotype-specific antibodies, particularly of the IgG4 subclass, is a sensitive indicator of past or present infection, and the prevalence of individuals with such increased levels may be a simple and reliable indicator of the frequency of schistosomiasis in a community.

We have determined the levels of IgG subclasses and IgE as well as specific antibodies of these isotypes in sera from 22 patients with clinical visceral leishmaniasis (VL) from Somalia. The results are compared with those obtained from 30 Somali and 23 Swedish controls. We found markedly increased concentrations of IgG1 in the VL sera, indicating that the pronounced increase in IgG in VL which is generally considered to be due to polyclonal B-cell activation is mainly restricted to this subclass. The IgG2 concentrations were significantly decreased. The IgG3 and IgG4 concentrations, on the other hand, did not differ between the two groups of Somali sera. The Somali control sera contained higher concentrations of IgG1 and IgG3, but significantly lower concentrations of IgG2 as compared to Swedish controls. The IgG4 values, on the other hand, were not different between the two groups of control sera. Anti-leishmania antibodies belonging to all IgG subclasses, were found in the patients' sera. There was no significant difference in total IgE between sera from VL patients and controls and specific IgE antibodies were only detected in a few patients. The Western blot assay (WB), revealed the presence of two bands corresponding to 74 kDa and 88 kDa in all patients' sera, indicating a possible diagnostic role for WB in this particular population.

Studies of vaccine-induced immunity in experimental schistosomiasis in mice have suggested that interferon-gamma (IFN-gamma) is an important factor for the induction of protective immunity against schistosomiasis. The present study compares some parameters during primary schistosome infection in IFN-gamma receptor deficient mice and wild type mice. No significant difference in worm burden between the two groups was found. Almost the same number of eggs in the liver as well as typical granulomas with numerous macrophages and eosinophils were observed in both groups of mice. Furthermore, IFN-gamma receptor deficient mice infected with S. mansoni displayed a significant reduction in the number of IgG2a secreting cells in the spleen and a significant enhancement of IgA secreting cells in the spleen and in the lungs. These findings suggest that the lack of IFN-gamma activity may result in an enhanced dominance of Th2 cells which, however, does not influence the development of a primary schistosome infection.

Background: There is a need for serologic markers in selecting patients with symptoms compatible with coeliac disease for intestinal biopsy and for population screening. Few comparative studies have been done., Methods: Sera from 55 patients with coeliac disease and 65 referents, aged between 8 months and 79 years, were investigated. Anti-gliadin, anti-reticulin, anti-endomysium, and anti-jejunal antibodies were measured. The sensitivities, specificities, and positive predictive values for different disease prevalence levels were calculated. Confidence intervals, rarely used in this type of study, were calculated., Results and Conclusions: In most tests the antibody levels were age-correlated. The highest sensitivities in combination with high specificities were found for IgA anti-gliadin antibodies in children less than 5 years of age and IgA anti-endomysium antibodies in older children and adults. These tests were most useful for testing a population with a high disease prevalence, such as patients with gastrointestinal symptoms, although the results for many tests had overlapping confidence intervals. For screening unselected populations with a low disease prevalence, in which a test with maximum specificity is desired, only anti-endomysium antibodies had sufficiently high predictive value to be of practical use.

Prevalence and disease manifestations of visceral leishmaniasis (VL) were studied in a Somali village in an area which has long been known to be endemic for VL. Demographic data were collected from 102 households, comprising 438 inhabitants. Clinical examination was performed of 306 individuals, 72% of the 426 eligible persons. Of these, 276 (90%) agreed to give blood and 246 (80%) to be skin tested with leishmanin. Leishmanin reactions were positive; in 26% anti-Leishmania antibodies were detected in 11%, and splenomegaly was recorded in 14% (23% of those who were seropositive). Malaria was hypoendemic and therefore unlikely to be responsible for more than 10% of the cases with splenomegaly. Three of the seropositive villagers with splenomegaly complained of feeling ill. The remaining 91 sero- and/or leishmanin-positive individuals had no complaint regarding their health and had not experienced any long period of illness. There was a slight over-representation of males in the group of sero- and/or leishmanin-positive villagers, possibly due to a gender-associated difference in exposure to the parasite. Among the patients with clinical VL treated at Mogadishu hospitals during 1989 and 1990, the male/female ratio was 3.3:1, which may indicate a selection of male patients for hospital care. Most patients were < or = 15 years old, suggesting that the highest risk of becoming clinically ill was among children.

The occurrence of Campylobacter and enterotoxigenic E. coli (ETEC) was studied in faecal samples from Tanzanian children (< 5 years of age), adolescents and adults (only Campylobacter) with and without diarrhoea. The Campylobacter strains isolated were tested for subspecies, enterotoxigenicity and serotype. Out of 394 children with diarrhoea 18% were infected with Campylobacter and 20% with ETEC. In 278 samples tested for Campylobacter and 136 tested for ETEC from asymptomatic children the corresponding numbers were 12 and 5%, respectively. In children < 18 months with diarrhoea Campylobacter was noted in 22% and ETEC in 18%, whereas the figures were 11 and 4% respectively in asymptomatic children. In the age group 18 months to 5 years Campylobacter was demonstrated in 2% of the children with diarrhoea and 27% had ETEC, while the figures were 15 and 8% for asymptomatic children. Among adults the prevalence of Campylobacter-positive samples was 1% both for symptomatic and asymptomatic individuals. There were no seasonal differences in the prevalences of both Campylobacter and ETEC either in the symptomatic or the asymptomatic group. Campylobacter jejuni was the dominating Campylobacter species among both symptomatic and asymptomatic individuals. C. jejuni strains from patients with diarrhoea were significantly more often enterotoxigenic than were C. coli strains. The serotype pattern regarding Campylobacter was in general similar for symptomatic and asymptomatic individuals. We conclude that Campylobacter and ETEC are common causes of bacterial diarrhoea in Tanzanian children, and that Campylobacter infections are more important in children younger than 18 months, than in older ones.

Serum bactericidal activity and phagocytic killing are two important mechanisms involved in the host defence against bacteria. Using some in vitro methods, serum bactericidal assay, phagocytic killing by polymorphonuclear leukocytes (PMN) and chemiluminescence, we have evaluated the significance of these mechanisms in the killing of Haemophilus ducreyi bacteria. Furthermore, induction of C3 conversion and deposition of immunoglobulins, C1q and C3, on the surface of bacteria was studied by crossed immunoelectrophoresis and ELISA, respectively. Transmission electron microscopy was employed to study internalization of bacteria by PMN. H. ducreyi and lipooligosaccharide preparations from these bacteria were able to induce conversion of complement factor C3 in normal human serum (NHS). Exposure of bacteria to NHS resulted in deposition of IgG, IgM and complement factors C1q and C3 on the surface of bacteria. H. ducreyi bacteria lost their viability when incubated with fresh but not inactivated normal serum at high concentrations, indicating that the bacteria are sensitive to the complement-dependent bactericidal activity of serum. There were some variations between different strains regarding their susceptibility to the bactericidal activity of NHS, but for eight strains tested, all of the bacteria exposed were not killed in medium containing up to 70% of fresh serum. Complement-mediated opsonophagocytic killing of H. ducreyi by PMN was more effective than complement-dependent bactericidal activity of fresh normal sera. Bacteria treated with heat inactivated immune sera, on the other hand, were as sensitive to the bactericidal effect of PMN as those treated with non-inactivated immune sera, indicating the role of antibodies in opsonophagocytosis. H. ducreyi bacteria were also killed by PMN in the absence of serum antibodies and complement. Using the chemiluminescence assay, H. ducreyi was shown to activate PMN in the absence of serum as well as after opsonization with complement and antibodies. Our results therefore indicate that both opsonic- and non-opsonic mechanisms are involved in the phagocytosis and the subsequent killing of H. ducreyi bacteria. Although both complement and antibodies enhance the ability of phagocytes to kill H. ducreyi, neither component is sufficient for effective killing of H. ducreyi.