Array-based profiling of ragweed and mugwort pollen allergens

BACKGROUND

Ragweed (Ambrosia artemisiifolia) and mugwort (Artemisia vulgaris) pollen is the main cause of allergic reactions in late summer and autumn. The differential diagnosis between ragweed and mugwort pollen allergy is a frequent problem encountered by allergologists in areas where both plants are present due to shared antigenic structures and overlapping flowering seasons.

OBJECTIVE

To evaluate the sensitization pattern of weed allergic patients towards a large panel of purified allergens in the microarray format and by enzyme-linked immunosorbent assay (ELISA).

METHODS

Eight ragweed and six mugwort pollen allergens were purified from natural source or expressed as recombinant proteins in Escherichia coli. Allergens were spotted on protein microarray slides or coated onto ELISA plates. Sera from 19 ragweed and/or mugwort allergic individuals were used to determine the reactivity towards single molecules in both assays.

RESULTS

All ragweed allergic individuals were sensitized to Amb a 1, among them 30% were monosensitized to the major ragweed allergen. Art v 1 and Art v 3 were recognized by 89% of mugwort pollen-allergic patients. Extensive cross-reactivity was observed for both patient groups mainly involving the pan-allergens profilin and nonspecific lipid transfer proteins. Comparable IgE profiles were obtained with both allergen microarray and ELISA methods.

CONCLUSIONS

Molecule-based diagnosis provides essential information for the differential diagnosis between ragweed and mugwort pollen allergy and for the selection of the appropriate allergen source for specific immunotherapy.

Molecular and immunological characterization of novel weed pollen pan-allergens

BACKGROUND

Pan-allergens like profilins, calcium-binding proteins (CBPs), and nonspecific lipid transfer proteins have been suggested as possible specific markers for multiple pollen sensitizations, and could be used to predict cross-sensitization/poly-sensitization to several pollen allergens. Therefore, the purification and characterization of cross-reacting allergens in pollen is an extremely important task towards correct allergy diagnosis.

METHODS

New pan-allergens were identified by screening a ragweed pollen cDNA library with sera of patients allergic to mugwort pollen. Resulting proteins were cloned, expressed, purified and characterized.

RESULTS

We report complete cDNA sequences of two profilin isoforms (Amb a 8.01 and Amb a 8.02), two isoforms of a 2EF-hand CBP (Amb a 9.01 and Amb a 9.02), a new 3EF-hand CBP (Amb a 10) from ragweed pollen and a 2EF-hand CBP from mugwort (Art v 5). All these proteins were expressed in Escherichia coli, purified to homogeneity and characterized by biochemical and immunological means.

CONCLUSIONS

The identified proteins are novel pan-allergens and can be used as diagnostic markers for polysensitization and used in component-resolved diagnosis.

The CREATE project: development of certified reference materials for allergenic products and validation of methods for their quantification

Allergen extracts have been used for diagnosis and treatment of allergy for around 100 years. During the second half of 20th century, the notion increasingly gained foothold that accurate standardization of such extracts is of great importance for improvement of their quality. As a consequence, manufacturers have implemented extensive protocols for standardization and quality control. These protocols have overall IgE-binding potencies as their focus. Unfortunately, each company is using their own in-house reference materials and their own unique units to express potencies. This does not facilitate comparison of different products. During the last decades, most major allergens of relevant allergen sources have been identified and it has been established that effective immunotherapy requires certain minimum quantities of these allergens to be present in the administered maintenance dose. Therefore, the idea developed to introduce major allergens measurements into standardization protocols. Such protocols based on mass units of major allergen, quantify the active ingredients of the treatment and will at the same time allow comparison of competitor products. In 2001, an EU funded project, the CREATE project, was started to support introduction of major allergen based standardization. The aim of the project was to evaluate the use of recombinant allergens as reference materials and of ELISA assays for major allergen measurements. This paper gives an overview of the achievements of the CREATE project.

Immunologic analysis of monoclonal and immunoglobulin E antibody epitopes on natural and recombinant Amb a 1

BACKGROUND

Amb a 1 is the major allergen from ragweed pollen and more than 90% of ragweed-allergic patients react with this protein. Although Amb a 1 was cloned and sequenced in 1991, little is known of the specificity of anti-Amb a 1 antibodies or of the immunologic properties of the recombinant allergen.

OBJECTIVE

To compare binding of monoclonal antibodies (mAb) and IgE antibodies to purified natural Amb a 1 (nAmb a 1) and recombinant Amb a 1 (rAmb a 1).

METHODS

Binding of a panel of anti-Amb a 1 mAb and IgE antibodies to nAmb a 1 or rAmb a 1 was compared by immunoblotting. Chimeric ELISA was used to measure specific IgE to these allergens using 89 ragweed-allergic sera from Austria, Italy, Canada and the United States.

RESULTS

The 8 mAb bound to a 38 kDa Amb a 1 band in ragweed pollen extract and a subset of 5 mAb also bound to the 26 kDa chain of nAmb a 1. A two-site ELISA was developed using a mAb pair, which was approximately 10-fold more sensitive to rAmb a 1. There was a significant correlation between IgE antibody binding to nAmb a 1 and rAmb a 1 (n=89, r=0.79, P<0.001). A subset of approximately 40% of patients showed greater reactivity to nAmb a 1 than to rAmb a 1.

CONCLUSIONS

The data suggest that there is less reactivity of human IgE to rAmb a 1 compared with nAmb a 1. The development of more sensitive, quantitative ELISA for Amb a 1 will require the production of new mAb especially directed against nAmb a 1.

Prevalence of IgE-binding to Art v 1, Art v 4 and Amb a 1 in mugwort-allergic patients

BACKGROUND

Mugwort (Artemisia vulgaris) represents an important source of weed pollen allergens. The objectives of the present study were (i) to analyze the IgE binding profiles in a group of mugwort-allergic patients, (ii) to identify individual marker allergens crucial for the diagnosis of mugwort allergy and (iii) to identify potential crossreactive allergens present in ragweed (Ambrosia artemisiifolia) pollen extract.

METHODS

Sera from 100 pediatric mugwort-allergic patients were analyzed for their IgE binding pattern to natural mugwort and ragweed pollen proteins, purified natural and recombinant Art v 1, recombinant Art v 4 and recombinant Amb a 1 using immunoblots and ELISA.

RESULTS

91% of the patients' sera tested displayed IgE binding to one or more mugwort pollen allergens in ELISA and 88% were positive in immunoblot. Purified natural Art v 1 was recognized by 79%, the recombinant protein by 39% of the patients tested and purified recombinant Art v 4 by 34% of the patients' sera. 67% of the sera displayed crossreactive IgE to one or more ragweed pollen allergens. Recombinant Amb a 1 was noted in only 14% of the mugwort-allergic sera.

CONCLUSIONS

Allergen-specific in vitro diagnosis was performed in 100 pediatric mugwort-allergic serum samples. Using two allergens (Art v 1 and Art v 4), 91% of the patients could be identified as mugwort pollen-sensitized patients by IgE in vitro tests. Crossreactivity to ragweed pollen allergens was demonstrated by in vitro experiments, suggesting a new important and potent allergen source expanding across Europe.

Successful HAART is associated with high B-chemokine levels in chronic HIV type 1-infected patients

Chemokine receptors are used by HIV-1 for entry into CD4+ T cells. The beta-chemokines are capable of inhibiting HIV replication. This study measured beta-chemokine macrophage inflammatory protein (MIP)-1alpha and MIP-1beta levels and determined the CCR5 and CXCR4 expression on T cells in HIV-1-infected patients treated with HAART. The time of known HIV infection and time of HAART use were similar between failure and successful groups. The CD4+ T cell nadir was 163 vs. 251 cells/mm3, p = 0.07, for failure and successful groups, respectively. The successfully treated group, when compared with the failure group, had a higher median CD4+ T cells count (667 vs. 257 cells/mm3; p = 0.003) as well as higher spontaneous MIP-1alpha (median of 4390 vs. 802 pg/ml, p = 0.03) and MIP-1beta (median of 2416 vs. 1117 pg/ml, p = 0.001) levels. The untreated patients had a higher number and intensity of CCR5- and CXCR4-expressing T cells. Higher levels of chemokines were not related to nadir CD4+ T and current CD8+ T cell counts. Successfully treated patients were able to produce higher amounts of beta-chemokines and normalize the coreceptor overexpression on T cells. These findings may have clinical implications, such as a new strategy of using chemokines as adjuvants in anti-HIV therapy.

Characterization of recombinant Mal d 4 and its application for component-resolved diagnosis of apple allergy

BACKGROUND

Profilins are ubiquitous panallergens that have been extensively characterized; yet, their clinical relevance is still unclear.

OBJECTIVE

The aim of the present study was to produce recombinant apple profilin (rMal d 4) and to evaluate its allergenic activity and its potency for component-resolved allergy diagnosis.

METHODS

Complementary DNA-derived Mal d 4 was cloned, expressed in Escherichia coli and subsequently purified via poly (l-proline) sepharose. A total of 28 sera from apple-allergic patients were used for IgE-ELISA, immunoblot, RAST and basophil histamine release (BHR) test. In addition, skin prick tests (SPTs) were performed in five patients.

RESULTS

Four different complementary DNA coding for apple profilin, Mal d 4, each with an open reading frame of 393 nucleotides, were identified. One isoform Mal d 4.0101 was expressed in Escherichia coli and subsequently purified. Mass spectroscopy revealed the expected mass of 13.826 for rMal d 4.0101, and circular dichroism analysis data were typical for a folded protein and small-angle X-ray scattering measurement identified the protein as a monomer. All the serum samples displayed IgE binding to rMal d 4.0101 in IgE ELISA, immunoblot and RAST. In immunoblotting, IgE binding to natural Mal d 4 was partially/completely inhibited by preincubation with rMal d 4.0101, and RAST values to apple extract were significantly reduced upon serum pretreatment with rMal d 4.0101. SPTs and BHR assays using purified rMal d 4.0101 were positive. Purified rMal d 4.0101 was destroyed within seconds when subjected to pepsin digestion.

CONCLUSIONS

Apple profilin complementary DNAs were identified. The physicochemical and allergenic properties of purified recombinant Mal d 4.0101 were evaluated showing that the recombinant protein was equal to the natural protein as shown by inhibition assays. Thus, Mal d 4 represents another example suitable for component-resolved diagnosis of food allergy.

Cross-reactive and species-specific immunoglobulin E epitopes of plant profilins: an experimental and structure-based analysis

BACKGROUND

Profilins are cross-reactive plant allergens responsible for multiple pollen sensitization and pollen-associated food allergy. While it is assumed that profilins from different species are immunologically equivalent, some studies suggest partial or even lacking IgE cross-reactivity between certain profilins.

OBJECTIVE

We aimed to obtain a semi-quantitative assessment of the contributions of conserved and species-specific epitopes to IgE binding of plant profilins.

METHODS

We compared model structures of profilins from timothy, mugwort, celery and bell pepper with crystal structures of birch and latex profilins. We predicted potential conformational epitopes that consisted of contiguous patches of at least 20% surface-exposed residues. Celery and timothy profilins were purified from their natural sources, and profilins from birch, mugwort, bell pepper and latex were expressed in Escherichia coli. The structural integrity of all purified proteins was confirmed by circular dichroism spectroscopy. IgE ELISAs and ELISA inhibitions using sera from 22 profilin-sensitized allergic patients were carried out.

RESULTS

Peptide backbone conformations of all six profilins were highly similar. Nine variable epitopes and two containing high proportions of conserved residues were predicted. IgE from all sera bound to all tested profilins and the amounts were highly correlated. However, IgE inhibition experiments revealed that up to 60% of total IgE binding was mediated by species-specific epitopes. The extent of cross-reactivity among profilins from timothy, birch, latex and celery was greater than cross-reactivity to mugwort and bell pepper profilins. This pattern was mirrored by sequence similarities among one of the predicted variable epitopes. Patients with IgE to cross-reactive epitopes displayed allergic reactions to a greater number of plant foods than patients having IgE directed to species-specific epitopes.

CONCLUSION

The large extent of cross-reactivity among plant profilins justifies using a single profilin for diagnosis. However, the fine specificity of IgE directed to variable epitopes may influence the clinical manifestation of profilin sensitization.

A recombinant allergen chimer as novel mucosal vaccine candidate for prevention of multi-sensitivities

BACKGROUND

As conventional immunotherapy is less efficacious in patients with allergic multi-sensitivities compared with mono-sensitized subjects, new intervention strategies are needed. Therefore, an allergen chimer was genetically engineered for treatment of multi-sensitization with birch and grass pollen on the basis of mucosal tolerance induction.

METHODS

The major birch pollen allergen Bet v 1 served as a scaffold for N- and C-terminal linkage of the immunodominant peptides of the grass pollen allergens Phl p 1 and Phl p 5 and this new construct was cloned and expressed in Escherichia coli. After purification, physicochemical and immunological characterization the chimer was used for intranasal tolerance induction prior to poly-sensitization with Bet v 1, Phl p 1 and Phl p 5.

RESULTS

The immunological characterization revealed that the conformation of Bet v 1 within the chimer was comparable to that of natural as well as recombinant Bet v 1. The chimer was immunogenic in mice for T and B cell responses to the three allergens. Intranasal application of the chimer prior to poly-sensitization significantly suppressed humoral and cellular allergen-specific Th2 responses and prevented development of airway inflammation upon allergen challenge. Moreover, local allergen-specific IgA antibodies were induced by the chimer. The mechanisms of poly-tolerance induction seemed to be mediated by regulatory cytokines, since TGF-beta and IL-10 mRNA in splenocytes were upregulated and tolerance was transferable with these cells.

CONCLUSION

The data indicate that such allergen chimers harboring several unrelated allergens or allergen peptides could serve as mucosal polyvalent vaccines for prevention of multi-sensitivities.

Collaborative monitoring of chlorine flavours in drinking water

Sensory data have always been used by concerned citizens to evaluate environmental variables within volunteer monitoring initiatives. The work presented in this paper intends to explore the possibility of using human sensory data as a source of information to monitor environmental quality variables within a public participation context. A case study that uses untrained citizens to monitor chlorine flavour of tap water is presented. Two collaborative monitoring tests were developed: (1) the one-sample one-trial test and (2) the Chlorine@Home test. The tests intended to address the participatory context required by collaborative monitoring initiatives. The development of the collaborative tests was supported by two tests that were designed for a laboratory context and explored sensory methodologies. The sensory tests implemented were: (1) the paired comparison test, (2) the forced-choice triangle test (ASTM Method E679-04). The collaborative experiments showed that the ability to detect chlorine flavours on a participatory context was independent on chlorine concentrations. The use of sensors by citizens may be a way to increase the credibility of the information. Nevertheless, this case study suggested that more research should be carried out to explore ways to involve citizens while increasing data reliability.

Artemisia and Ambrosia hypersensitivity: co-sensitization or co-recognition?

BACKGROUND

Ragweed and mugwort have nearly identical flowering periods. Clinical and serological studies showed that ragweed and mugwort sensitization are often associated and this poses relevant clinical problems in patients for whom specific immunotherapy is warranted.

OBJECTIVE

To establish whether the concurrent ragweed and mugwort pollen hypersensitivity is the result of co-sensitization or of co-recognition by using purified recombinant allergens.

METHODS

Sensitization to ragweed and mugwort pollen was assessed by skin prick test (SPT) in all patients reporting allergic symptoms in August and September. IgE reactivity of sera from 42 patients (26 Amb+/Art+, 14 Amb+/Art-, and two Amb-/Art+) to ragweed and mugwort pollen extract as well as to several recombinant ragweed (rAmb a 1, rAmb a 5, rAmb a 6, rAmb a 8, rAmb a 9, and Amb a 10) and mugwort (rArt v 1, rArt v 4, rArt v 5, rArt v 6, and three EF-hand calcium-binding protein) allergens was detected by dot-blot and ELISA analyses.

RESULTS

IgE reactivity of 372 weed pollen-allergic patients was studied. Mugwort reactivity was strongly associated with ragweed hypersensitivity: only 10/147 (7%) mugwort-hypersensitive patients were not sensitized to ragweed, whereas 225/362 (62%) ragweed-hypersensitive patients were not sensitized to mugwort. In vitro, 90% of ragweed-allergic patients reacted with rAmb a 1. Reactivity to other ragweed allergens ranged between 20% and 35%. Forty-six percent of the mugwort-sensitized patients recognized rArt v 1%, 25% reacted to Art v 4, Art v 5, and Art v 6, and 7% recognized the three-EF hand calcium-binding protein. Immunoblot inhibition experiments showed that pre-incubation with ragweed pollen extract only weakly decreased IgE reactivity to mugwort allergens.

CONCLUSION

Patients showing both ragweed- and mugwort-positive SPT and/or RAST are co-sensitized. Future studies will establish whether IgE reactivity translates into clinical symptoms and, hence, if co-sensitized patients should undergo specific immunotherapy with extracts of both mugwort and ragweed pollen.

Parâmetros fisiológicos de bovinos cruzados submetidos ao estresse calórico

Caracterizaram-se as respostas fisiológicas de termorregulação em conforto e estresse calórico de bovinos cruzados F2 (½ Gir x ½ Holandês), machos e fêmeas, com idade entre 14 e 20 meses. Os animais foram alocados, em número de cinco, e submetidos ao conforto térmico (22°C a 70% de umidade relativa) por 12 horas e ao estresse calórico (42ºC e 60% de umidade relativa) durante seis horas, logo após o período de conforto, nas estações de verão e inverno, em câmara bioclimática. Nas duas etapas, foram registradas a temperatura retal (TR), a freqüência respiratória (FR) e a temperatura de superfície corporal (TSC) às 6 e 16 horas. Os animais apresentaram aumento da TR, da FR e da TSC no período de estresse calórico (P<0,05). O aumento da TR e FR foi mais acentuado no verão (P<0,05). A TSC não apresentou diferença entre as estações (P<0,05).

Allergenicity assessment of apple cultivars: hurdles in quantifying labile fruit allergens

BACKGROUND

Assessment of allergenicity of foods is important for allergic consumers and regulators. Immunoassays to measure major food allergens are widely applied, often giving variable results. Using the major apple allergen Mal d 1 as a model, we aimed to establish at the molecular level why different immunoassays for assessing allergenicity of apple cultivars produce conflicting outcomes.

METHODS

Mal d 1 was measured in 53 cultivars from Italy and 35 from The Netherlands, using four different immunoassays. Purified Mal d 1 standards were molecularly characterized by size-exclusion chromatography (SEC) and mass spectrometry (MS).

RESULTS

Three immunoassays using an identical standard gave similar results. Minor differences in sample preparation already resulted in significant loss of allergenicity. The fourth assay, using a different Mal d 1 standard, gave 10- to 100-fold lower outcomes. By SEC, this standard was shown to be almost fully aggregated. This aggregation was accompanied by a decrease of the mass of the Mal d 1 molecule by approximately 1 kDa as analyzed by MS. The deviating immunoassay was shown to selectively recognize this aggregated form of Mal d 1, whereas the other three assays, including the one based on IgE antibody recognition, preferentially bound non-aggregated allergen.

CONCLUSIONS

Variable and poorly controllable major allergen modification in both extracts and standards hamper accurate allergenicity assessments of fruits.

Inhibition of type I allergic responses with nanogram doses of replicon-based DNA vaccines

BACKGROUND

Allergic diseases have become a major public health problem in developed countries; yet, no reliable, safe and consistently effective treatment is available. DNA immunization has been shown to prevent and balance established allergic responses, however, the high dose of conventional DNA vaccines necessary for the induction of anti-allergic reactions and their poor immunogenicity in primates require the development of new allergy DNA vaccines. We evaluated protective and therapeutic effects of a Semliki-Forest Virus replicase-based vs a conventional DNA vaccine in BALB/c mice using the model allergen beta-galactosidase.

METHODS

Immunoglobulin (Ig)E suppression was determined by a basophil release assay as an in vitro correlate for allergen-specific crosslinking capacity of IgE reflecting the in vivo situation in an allergic individual. Th1 memory responses were measured by cytokine detection via enzyme-linked immunosorbent assay (ELISA) and enzyme-linked immunospot assay (ELISPOT).

RESULTS

Nanogram amounts of a replicase-based vector triggered a Th1 response comparable with that achieved with the injection of 20,000-times more copies of a conventional DNA plasmid, and induced IgE suppression in both a protective and a therapeutic setting.

CONCLUSIONS

Replicase-based DNA vaccines fulfill the stringent criteria for an allergy DNA vaccine, i.e. low dose, strong Th1 immunogenicity and memory, lack of 'therapy-induced' IgE production and anaphylactic side effects. Moreover, by triggering apoptosis in transfected cells, their unique 'immunize and disappear' feature minimizes the hypothetical risks of genomic integration or induction of autoimmunity.

Profiling preparations of recombinant birch pollen allergen Bet v 1a with capillary zone electrophoresis in pentamine modified fused-silica capillaries

Three preparation batches of the recombinant birch pollen allergen Bet v 1a have been analyzed by capillary zone electrophoresis (CZE) using a separation electrolyte consisting of 100 mmol L(-1) phosphate at pH 6.50 with 2.0 mmol L(-1) tetraethylenepentamine (TEPA) added. TEPA improved the resolution by wall shielding and selective attachment to allergens, but reduced migration repeatability at concentrations >2.0 mmol L(-1). Heterogeneity of preparations determined by CZE and electrospray ionization-quadrupole-time-of flight-MS were in accordance and revealed chemically modified (carbamylated) allergens in one of the preparations. The method was validated according to the ICH-guidelines. Repeatability of effective electrophoretic mobility (mu(eff)) was <0.55% R.S.D. (n = 5). Migration time corrected peak areas were used for quantification. Limit of quantification (LOQ) was 25 microg mL(-1) for the major isoform Bet v 1a, based on a signal-to-noise ratio of 10, and detector response was linear between LOQ and 0.90 mg mL(-1). Purity of the different rBet v 1a preparations was determined to be between 40 and 92% depending on the manufacturing protocol.

A mutant of the major apple allergen, Mal d 1, demonstrating hypo-allergenicity in the target organ by double-blind placebo-controlled food challenge

BACKGROUND

Allergen-specific immunotherapy for food allergy has been hindered by severe side-effects in the past. Well-characterized hypo-allergenic recombinant food allergens potentially offer a safe solution.

OBJECTIVE

To demonstrate hypo-allergenicity of a mutated major food allergen from apple, Mal d 1, in vitro and in vivo.

METHODS

A mutant of the major apple allergen, Mal d 1, was obtained by site-directed mutagenesis exchanging five amino acid residues. Fourteen patients with combined birch pollen-related apple allergy were included in the study. Hypo-allergenicity of the mutant rMal d 1 (rMal d 1mut) compared with rMal d 1 was assessed by in vitro methods, i.e. RAST (inhibition), immunoblotting and basophil histamine release (BHR) and in vivo by skin prick test and double-blind placebo-controlled food challenge (DBPCFC).

RESULTS

RAST analysis (n = 14) revealed that IgE reactivity to rMal d 1mut was twofold lower than that of the wild-type molecule (95% confidence interval (CI): 1.7-2.4). RAST inhibition (n = 6) showed a 7.8-fold decrease in IgE-binding potency (95% CI: 3.0-12.6). In contrast to this moderate decrease in IgE-binding potency, the biological activity of rMal d 1mut assessed by SPT and BHR decreased 10-200-fold. Hypo-allergenicity was confirmed by DBPCFC (n = 2) with both recombinant molecules.

CONCLUSION

A moderate decrease in IgE-binding potency translates into a potent inhibition of biological activity. This is the first study that confirms by DBPCFC that a mutated recombinant major food allergen is clinically hypo-allergenic. This paves the way towards safer immunotherapy for the treatment of food-allergic patients.

Pollen-food syndromes associated with weed pollinosis: an update from the molecular point of view

Pollinosis patients often display adverse reactions upon the ingestion of plant-derived foods as a result of immunoglobulin E (IgE) cross-reactive structures shared by pollen and food allergen sources. The symptoms of such pollen-food syndromes (PFS) or class 2 food allergies range from local oral allergy syndrome to severe systemic anaphylaxis. Two clinical syndromes, the celery-mugwort-spice syndrome and the mugwort-mustard-allergy syndrome have been described in association with weed pollinosis. However, other associations between weed pollinosis and hypersensitivity to certain kinds of food have also been observed, like the mugwort-peach, the ragweed-melon-banana, the plantain-melon, the pellitory-pistachio, the goosefoot-fruit, the Russian thistle-saffron, and the hop-celery association. The number of allergen sources involved, the allergens, and influencing factors including geography, diet, and food preparation contribute to the high clinical complexity of PFS. So far, known causative cross-reactive allergens include profilins, lipid transfer proteins, and high-molecular weight allergens and/or glycoallergens. The current usage of nonstandardized allergen extracts poses additional problems for both diagnosis and therapy of PFS patients. Further identification and characterization of involved allergens is inescapable for better understanding of PFS and vaccine development. Panels of recombinant allergens and/or hypo-allergens are promising tools to improve both PFS diagnostics and therapy.

Structural changes in calcium-binding allergens: use of circular dichroism to study binding characteristics

BACKGROUND

Several studies showed that calcium-binding proteins have a fixed place in the spectrum of allergenic substances. Often the binding of a calcium ion induces conformational changes and affects immunoglobulin E-binding to the allergen. Hence, the quantitative characterization of the binding to calcium is of importance to understand both the biologic and allergenic activity of these proteins.

AIMS OF THE STUDY

In the present study we describe a procedure for determining the stoichiometry and dissociation constant (K(D)) of calcium-binding allergens using circular dichroism (CD) techniques. For the experiments, we used recombinant Bet v 4, a two EF-hand allergen from birch pollen.

METHODS

Solutions of Bet v 4 were titrated with calcium and the change in molar ellipticity at 222 nm was monitored with a CD spectropolarimeter.

RESULTS

The determination of the binding stoichiometry as well as of the K(D) for one EF-hand (4 microM) demonstrated the applicability of the method.

CONCLUSIONS

CD-monitored calcium-titration of protein solutions represents a fast and easy method for determining the binding characteristics of calcium-binding allergens.

Genotoxic evaluation of a vinifera skin extract that present pharmacological activities

Toxicity of an alcohol-free hydro-alcoholic grape skin extract (GSE) obtained from red grapes Vitis labrusca (Isabel varietal) that present antihypertensive, vasodilator and antioxidant effects was estimated by different bioassays. Using the Salmonella/microsome assay for strains TA97, TA98, TA100 and TA102 no mutagenicity was detected for all tested concentrations (0.1-100 microg/ml), even with metabolization. Nevertheless, cytotoxicity was observed for TA97 and TA102 with and without metabolization and for TA100 with metabolization. The measurement of beta-galactosidase induction in the SOS-chromotest was positive only for Escherichia coli PQ37 when metabolization enzymes were present. Using Balb/c 3T3 fibroblasts, DNA strand breaks induction by GSE was also investigated by the comet assay and no significative difference was detected for treated and no treated DNA for 60 min. Our data suggest that GSE although no mutagenic presents cytotoxic activity.

Allergic cross-reactivity: from gene to the clinic

A large number of allergenic proteins have now their complete cDNA sequences determined and in some cases also the 3D structures. It turned out that most allergens could be grouped into a small number of structural protein families, regardless of their biological source. Structural similarity among proteins from diverse sources is the molecular basis of allergic cross-reactivity. The clinical relevance of immunoglobulin E (IgE) cross-reactivity seems to be influenced by a number of factors including the immune response against the allergen, exposure and the allergen. As individuals are exposed to a variable number of allergenic sources bearing homologous molecules, the exact nature of the antigenic structure inducing the primary IgE immune response cannot be easily defined. In general, the 'cross-reactivity' term should be limited to defined clinical manifestations showing reactivity to a source without previous exposure. 'Co-recognition', including by definition 'cross-reactivity', could be used to describe the large majority of the IgE reactivity where co-exposure to a number of sources bearing homologous molecules do not allow unequivocal identification of the sensitizing molecule. The analysis of reactivity clusters in diagnosis allows the interpretation of the patient's reactivity profile as a result of the sensitization process, which often begins with exposure to a single allergenic molecule.

Characterization of the protective and therapeutic efficiency of a DNA vaccine encoding the major birch pollen allergen Bet v 1a

BACKGROUND

An estimated 100 million individuals suffer from birch pollen allergy. More than 95% of birch pollen-allergic subjects react with the major birch pollen allergen Bet v 1a, and almost 60% of them are sensitized exclusively to this allergen.

OBJECTIVE

DNA immunization using the Bet v 1a gene was evaluated with respect to its prophylactic and therapeutic efficacy.

METHODS

A DNA vaccine containing the entire Bet v 1a cDNA under the control of a CMV-promoter was constructed. In order to estimate the protective efficiency, animals received three injections of this vaccine prior to sensitization with recombinant Bet v 1a. Vice versa, in a therapeutic approach, sensitization was followed by treatment with the DNA vaccine.

RESULTS

The Bet v 1a DNA vaccine induced strong Bet v 1-specific antibody responses with a Th1-biased response type. Animals which received the DNA vaccine were protected against a following allergic sensitization with Bet v 1a. The protective effect was characterized by suppression of Bet v 1-specific immunoglobulin (Ig)E production, lack of basophil activation and enhanced interferon (IFN)-gamma expression. In a therapeutic situation, treatment of sensitized animals with DNA vaccines decreased IgE production, IgE-mediated basophil release and drastically reduced anaphylactic activity as measured by passive cutaneous anaphylaxis assays. Concerning the cellular immune response, DNA immunization induced a sustaining and dominant shift from a Th2 type response towards a balanced Th1/Th2 type response as indicated by increased IFN-gamma but unchanged IL-5 levels in lymphoproliferation assays.

CONCLUSION

The results demonstrate the allergen-specific protective and therapeutic efficacy of a DNA vaccine encoding the clinically highly relevant allergen Bet v 1a indicating the suitability of this concept for the treatment of allergic diseases.

Fagales pollen sensitization in a birch-free area: a respiratory cohort survey using Fagales pollen extracts and birch recombinant allergens (rBet v 1, rBet v 2, rBet v 4)

BACKGROUND

Birch allergy is one of the most common pollinosis in areas where exposure to high levels of birch pollen is common. Little is known about birch sensitivity in areas without birch pollen exposure and reactivity to birch-related species within the Fagales order.

OBJECTIVE

the aim was to evaluate Fagales reactivity within a population not exposed to birch pollen using epidemiological, diagnostic, and laboratory approaches by means of extracts and allergenic molecules.

METHODS

A cohort of 5335 respiratory allergic patients was screened by means of skin testing birch, hazel, and oak pollen extracts. Patients were from a birch-free area, but exposed to other Fagales pollen species. A subset of patients was from an intensively cultivated hazel area. A sample of the Fagales allergic population was tested with other Fagales pollen extract (alder, hornbeam, beech, chestnut) and with apple and hazelnut. IgE detection was performed with birch, hazel, oak, apple, and hazelnut extracts, and with Bet v 1, Bet v 2, Bet v 4, and bromelain. IgE immunoblots were performed using birch and hazel extracts. Epidemiological, clinical, and laboratory data were analysed by stratifying the allergic population.

RESULTS

Twenty-five percent of the pollen allergic cohort was skin test positive to at least one of the three Fagales species. Combined reactivity to the three species was recorded in 80% of this cohort. Isolated hazel pollen reactivity was recorded in 13.5% of the Fagales allergic patients. Sixty-six percent of these subjects were from the intensively cultivated hazel area. Reactivity to apple and hazelnut was detected by skin test (40%) and IgE reactivity (60%), but only 19% of the positive patients reported symptoms related to at least one of the two foods. Reactivity to Bet v 1 was recorded in 84% of the birch/hazel/oak co-reactivity group, and in 28% of the subjects with the same co-reactivity, but associating a multiple pollen sensitization. IgE to Bet v 2 (50%) and Bet v 4 (23%) panallergens were recorded positive in the latter subset. Bet v 1 prevalence ranged between 48% and 21% among subgroups of patients coming from different areas. Furthermore, an IgE reactivity to hazel-restricted allergenic components was detected among subjects coming from the same area and having a hazel isolated reactivity.

CONCLUSION

Fagales allergy can be found in birch-free areas caused by the exposure to other Fagales species. Birch allergens can be useful for mimicking the allergenic extract, but are also the exclusive tools for a fine diagnostic and epidemiological approach to Fagales pollen allergy. Allergenic molecules from the hazel family will increase the panel of available reagents for the molecule-based approach to allergy diagnosis and therapy.

Optimization of codon usage is required for effective genetic immunization against Art v 1, the major allergen of mugwort pollen

BACKGROUND

As the major allergen of mugwort pollen, Art v 1 is an important target for specific immunotherapy. However, both recombinant protein as well as a gene vaccine for Art v 1 failed to be immunogenic in mice. In order to improve immunogenicity we focused on genetic immunization because interspecific differences of codon usage have been shown as an obstacle for effective induction of immune responses with gene vaccines encoding infectious pathogens.

OBJECTIVE

In order to find out, whether codon usage might also be used to improve genetic immunization with allergen genes, the response against a gene vaccine expressing the wild-type gene of Art v 1 (pCMV-wtArt) was compared with a synthetic codon-optimized vector with human codon usage (pCMV-humArt).

METHODS

Balb/c mice were injected intradermally with pCMV-wtArt or pCMV-humArt. In vitro expression levels of both constructs were compared in transfection experiments. Total immunoglobulin G (IgG), IgG1, IgG2a and IgE antibodies were analyzed by enzyme-linked immunosorbent assay and the anaphylactic activity of the sera was determined by allergen-specific degranulation of rat basophil leukemia-2H3 cells.

RESULTS

No immune response was detectable with the gene vaccine expressing the wildtype Art v 1, but immunization with pCMV-humArt revealed a strong and allergen-specific induction of antibody responses. The antibodies recognized both the recombinant as well as the purified natural (glycosylated) Art v 1 molecule. The response type was Th1-biased, as indicated by high levels of IgG2a antibodies. Expression analysis with B16 mouse melanoma cells transfected with pCMV-humArt or pCMV-wtArt revealed an impaired expression of the wild-type vector but normal translation after recoding.

CONCLUSION

The results demonstrate that optimization of codon usage offers a simple way to improve immunogenicity and therefore should be routinely considered in the development of gene vaccines for the treatment of allergy.

Cloning and molecular and immunological characterisation of two new food allergens, Cap a 2 and Lyc e 1, profilins from bell pepper (Capsicum annuum) and Tomato (Lycopersicon esculentum)

BACKGROUND

Profilins are recognised by IgE of about 20% of patients allergic to birch pollen and plant foods. They are ubiquitous intracellular proteins highly cross-reactive among plant species. Therefore, they were called panallergens and are made responsible for cross-sensitisation between plant pollen and food.

OBJECTIVES

The aim of the present study was to clone the cDNAs encoding profilins from bell pepper and tomato, to produce and purify the recombinant proteins and to compare their IgE-binding capacities to those of the natural proteins.

METHODS

cDNA clones coding for profilin were obtained by RT-PCR from total RNA of tomato and bell pepper fruits, sequenced and expressed as non-fusion proteins in ESCHERICHIA COLI. The recombinant profilins were subsequently purified and tested for IgE-binding and inhibition capacity with sera from 34 food-allergic patients. Possible oligomerisation of recombinant profilins was investigated by HPLC analysis and its influence on IgE binding assayed by ELISA.

RESULTS

The open reading frame from both profilins encompasses 393 bp with a predicted molecular mass of 14,184 kD and a pI of 4.44 for bell pepper profilin (Cap a 2) and 14,257 kD and a pI of 4.46 for the profilin from tomato (Lyc e 1). The two protein sequences display 91% identity, whereas tomato profilin from pollen shares only 75% identity with tomato fruit profilin. Eleven out of 34 food-allergic patients (32%) display IgE binding to both purified profilins. Preincubation of a serum pool with either purified rCap a 2 or rLyc e 1 nearly abolished IgE binding to natural Cap a 2 and Lyc e 1, respectively. In addition, purified recombinant Cap a 2 was able to inhibit IgE-binding to rLyc e 1 by approximately 50%, whereas rLyc e 1 completely blocked IgE-binding to rCap a 2 in cross-inhibition assays. HPLC analysis showed that in solution Cap a 2 and Lyc e 1 can be found predominantly as dimers, which can be partially reduced to monomers by addition of dithiothreitol (DTT). In ELISA DTT-treated Lyc e 1 displayed a clearly lower IgE-binding capacity than untreated profilin.

CONCLUSIONS

Purified rCap a 2 and rLyc e 1 proved to be valuable tools for studying cross-reactivity to profilins in patients allergic to pollen and food.

Prevalence of Neospora caninum antibodies in dogs from dairy cattle farms in Parana, Brazil

Serum samples from 134 dogs from 22 cattle dairy farms in the northern region of Parana State, Brazil, were tested for antibodies to Neospora caninum in an indirect fluorescent antibody test. Antibodies (> or = 1:50) to N. caninum were found in 29 (21.6%) of the 134 dogs, and seropositive dogs were found on 14 (63.6%) of the 22 dairy cattle farrms. The antibody titers of dogs were 1:50 (3 dogs), 1:100 (7 dogs), 1:200 (7 dogs), 1:400 (6 dogs), and > or = 1:800 (6 dogs). The low prevalence (9%) in < 1-yr-old dogs compared with the 2- to 3-fold higher prevalence in older dogs (17-29%) suggests postnatal exposure to N. caninum infection.

Second and subsequent lines of chemotherapy for metastatic breast cancer: what did we learn in the last two decades?

Despite almost 30 years of clinical cancer research, the true impact of second and subsequent lines of chemotherapy on the outcome of metastatic breast cancer patients, especially on the duration of survival, is still unknown. In the virtually incurable metastatic setting, issues like quality of life and patients' preferences gain particular relevance. At the turn of the century, in-depth rethinking of the design of clinical trials run in this challenging disease setting appears to be warranted.

Seroprevalence of Toxoplasma gondii in captive neotropical felids from Brazil

Seroprevalence of Toxoplasma gondii was determined in 865 captive neotropical felids from 20 states from Brazil, sampled from September 1995 to April 1997. Sera were tested by the modified agglutination test (MAT) using formalin-fixed whole tachyzoites and mercaptoethanol. Antibodies (MAT> or =1:20) to T. gondii were found in 472 of 865 (54.6%) cats: in 45 of 99 (45.9%) jaguarundis (Herpailurus yagouaroundi), in 97 of 168 (57.7%) ocelots (Leopardus pardalis), in 68 of 131 (51.9%) oncillas (L. tigrinus), in 35 of 63 (55.5%) margays (L. wiedii), in 1 of 8 (12.5%) Pampas-cat (Oncifelis colocolo), in 9 of 12 (75.0%) Geoffroys-cat (O. geoffroyi), in 134 of 212 (63.2%) jaguars (Panthera onca), and in 83 of 172 (48.2%) pumas (Puma concolor). Antibody titers were: 1:20 in 27 felids, 1:25 in 142 felids, 1:40 in 6 felids, 1:50 in 292 felids, and > or =1:500 in 5 felids. The high seroprevalence of T. gondii antibodies found in the present study suggested a widespread exposure of neotropical cats to T. gondii in zoos in Brazil. The results warrant an investigation on the mode of exposure and oocyst shedding by neotropical cats.

In vitro evaluation of the effects of some acaricides on life stages of Rhipicephalus sanguineus (Acari: Ixodidae)

The action of five acaricides was evaluated on eggs, larvae, nymphs and adults of the ixodid tick Rhipicephalus sanguineus. The acaricides tested were: high cis-cypermethrin (0.01%) + DDVP (0.11%), coumaphos (0.05%), deltamethrin (0.0025%), amitraz (0.025%) and cypermethrin (0.015%). Eggs treated with high cis-cypermethrin and cypermethrin showed eclosion inhibitions of 72.1% and 67.3%, respectively, whereas coumaphos was much less effective (only 11.7%). Except for coumaphos, which resulted in 63.3% and 80.0% mortality of nymphs and unfed females, respectively, all compounds tested killed 100% of all tick stages to which they were exposed.

Influence of the variable number of tandem repeats located in the promoter region of the thiopurine methyltransferase gene on enzymatic activity

BACKGROUND

The genetic polymorphism of thiopurine methyltransferase (TPMT) activity has a significant relevance in the clinical outcome of patients receiving thiopurine drugs as immunosupressive or anticancer therapies. Apart from several open reading frame mutations unequivocally associated with decreased TPMT activity, a variable number of tandem repeats (VNTR), located within the 5' untranslated region, was recently reported as also affecting gene expression.

AIMS AND METHODS

We have characterized both molecularly, by polymerase chain reaction-based techniques, and enzymatically, with an HPLC-based method, a sample of 143 Portuguese Caucasian individuals with the main objective of deepening the study of the TPMT genotype/phenotype relationship. Because two different repeated elements (A and B) do contribute to the overall VNTR variation, we set out to analyze their combined and individual effects on TPMT activity.

RESULTS

Allele VNTR*6 was found to be consistently associated with decreased levels of TPMT activity, supporting previous reports that the VNTR does affect levels of TPMT activity, although moderately and in a way not yet clearly defined. Furthermore, individual analysis of the A and B variations suggested that three B repeats was the likely motif influencing gene expression toward decreased transcription.

CONCLUSIONS

Our hypothesis, which emphasizes the number of particular motifs within the VNTR internal structure more than the undiscriminated number of repeats as the potential causative factor affecting TPMT activity, needs further support from future studies, namely, from enlarged population samples. However, the knowledge of the VNTR acting mechanism will represent an important step toward fully understanding how the phenotypic variability at the TPMT trait is modulated.

Thematic Roles Assigned along the Garden Path Linger

In the literature dealing with the reanalysis of garden path sentences such as While the man hunted the deer ran into the woods, it is generally assumed either that people completely repair their initial incorrect syntactic representations to yield a final interpretation whose syntactic structure is fully consistent with the input string or that the parse fails. In a series of five experiments, we explored the possibility that partial reanalyses take place. Specifically, we examined the conditions under which part of the initial incorrect analysis persists at the same time that part of the correct final analysis is constructed. In Experiments 1a and 1b, we found that both the length of the ambiguous region and the plausibility of the ultimate interpretation affected the likelihood that such sentences would be fully reanalyzed. In Experiment 2, we compared garden path sentences with non-garden path sentences and compared performance on two different types of comprehension questions. In Experiments 3a and 3b, we constructed garden path sentences using a small class of syntactically unique verbs to provide converging evidence against the position that people employ some sort of "general reasoning" or pragmatic inference when faced with syntactically difficult garden paths. The results from these experiments indicate that reanalysis of such sentences is not always complete, so that comprehenders often derive an interpretation for the full sentence in which part of the initial misanalysis persists. We conclude that the goal of language processing is not always to create an idealized structure, but rather to create a representation that is "good enough" to satisfy the comprehender that an appropriate interpretation has been obtained.

Risk factors to tick infestations and their occurrence on horses in the state of São Paulo, Brazil

From December 1998 to March 1999, 40 stud farms were studied in the state of São Paulo, Brazil. During visits to farms, horses reared under grazing conditions were examined for the presence of ticks. On each farm visit, horse pastures were closely inspected and a questionnaire was given to the farm supervisor with the purpose of gaining information about ecological and management variables (independent variables) that could be associated with the presence and infestation levels of ticks on the farm (dependent variables). Three tick species were found during the study. Anocentor nitens, Amblyomma cajennense and Boophilus microplus were present on horses from 38 (95%), 20 (50%) and four (10%) farms, respectively. All farms that had A. cajennense or B. microplus infestations also had A. nitens infestations. Only one of the four farms with B. microplus infestations on the horses also had A. cajennense infestations. Two farms had all horses free of ticks. There was a strong association between the presence of infestation by B. microplus on horses and the simultaneous use of a grazing area by cattle and horses (P = 0.000). There was no statistical association between any of the independent variables and the presence or infestation level of A. nitens on the horses (P > 0.20). The presence of A. cajennense was statistically associated with the presence of at least one mixed overgrowth pasture in the farm (P = 0.001). A mixed overgrowth pasture means the presence of undesired plants such as bushes and shrubs in the pasture. The presence of high levels of A. cajennense on horses was also associated with the presence of at least one mixed overgrowth pasture in the farm (P = 0.026). The regular use of acaricides was statistically associated with the presence of ticks on the horses (P < 0.05), making this procedure a result of the inefficacy of controlling ticks on the farms. The occurrence of human infestation by ticks was statistically associated with the presence of A. cajennense on the horses (P=0.000). The presence of at least one mixed overgrowth pasture on the farm was associated (P = 0.000) to either higher horse densities and to farms that did not mow all the pastures once a year, indicating that mowing all the pastures at least once a year can be considered a protective factor against the presence of mixed overgrowth pastures on the farm, and consequently, against the presence of A. cajennense on the horses.

Evaluation of HER2, p53, bcl-2, topoisomerase II-alpha, heat shock proteins 27 and 70 in primary breast cancer and metastatic ipsilateral axillary lymph nodes

BACKGROUND

Breast cancer is a heterogeneous disease. Predictive biological markers (BM) of responsiveness to therapy need to be identified. Evaluation of BM is mainly done at the primary site. However, in the adjuvant therapy of breast cancer, the main goal is control of micrometastases. It is still unknown whether heterogeneity in the expression of BM between the primary site and its micrometastases exists.

OBJECTIVE

To evaluate the expression of some BM with potential predictive value from the primary breast cancer site and metastatic ipsilateral axillary lymph nodes.

PATIENTS AND METHODS

Focality (percentage of positive cells) and intensity staining scores were evaluated for each marker. Freshly cut sections (4 microm) from embedded blocks of breast cancer fixed in formalin or bouin were put onto superfrost slides (Menzel-Gläser). Protein expression was evaluated immunohistochemically (IHC) using monoclonal antibodies against: topo II-alpha (clone KiS1, 1 microg/ml, Roche) with a trypsine pre-treatment (P); HSP27 (clone G3.1, 1/60, Biogenex), HSP70 (clone BRM.22, 1/80, Biogenex) and HER2 (clone CB11, 1/40, Novocastra; without P); p53 (clone D07, 1/750, Dako) and bcl-2 (clone 124, 1/60, Dako) with citrate buffer as P.

RESULTS

Overall, the percentage of discordant marker status in the primary tumour and its metastatic lymph nodes was 2% for HER2, 6% for p53, 15% for bcl-2, 19% for topoisomerase II-alpha, 24% for HSP27 and 30% for HSP70. For the subgroup of patients with positive BM in the primary tumour, the percentage of discordance was 6% for HER2, 7% for p53, 14% for bcl-2, 19% for HSP70, 21% for topoisomerase II-alpha and 36% for HSP27. For the subgroup of patients with positive BM in the lymph nodes, the percentage of discordance was 9% for bcl-2, 15% for HER2 and p53, 21% for topoisomerase II-alpha, 22% for HSP27 and 25% for HSP70.

CONCLUSIONS

1) No biological marker had 100% concordant results. 2) Although some discordant cases might be explained by the limitations of the IHC technique, future studies aiming to evaluate the predictive value of BM in the adjuvant therapy of breast cancer should take into account a possible difference in BM expression between the primary and the metastatic sites.

Molecular and physiological characterisation of a 14-3-3 protein from lily pollen grains regulating the activity of the plasma membrane H+ ATPase during pollen grain germination and tube growth

A 14-3-3 protein has been cloned and sequenced from a cDNA library constructed from mRNAs of mature pollen grains of Lilium longiflorum Thunb. Monoclonal antibodies (MUP 5 or MUP 15) highly specific against 14-3-3 proteins recognised a 30-kDa protein in the cytoplasmic fraction of many various lily tissues (leaves, bulbs, stems, anther filaments, pollen grains, stigmas) and in other plants (Arabidopsis seedlings, barley recombinant 14-3-3). In addition, 14-3-3 proteins were detected in a microsomal fraction isolated from pollen grains and tubes, and the amount of membrane-bound 14-3-3 proteins as well as the amount of the plasma membrane (PM) H+ ATPase increased during germination of pollen grains and tube growth. No change was observed in the cytoplasmic fraction. A further increase in the amount of 14-3-3 proteins in the microsomal fraction was observed when pollen grains were incubated in germination medium containing 1 microM fusicoccin (FC) whereas the number of 14-3-3s in the cytoplasmic fraction decreased. Fusicoccin also protected membrane-bound 14-3-3 proteins from dissociation after washing with the chaotropic salt KI. Furthermore, FC stimulated the PM H+ ATPase activity, the germination frequency and the growth rate of pollen tubes, thus indicating that a modulation of the PM H+ ATPase activity by interaction with 14-3-3 proteins may regulate germination and tube growth of lily pollen.

[Prognosis of mitral commissurotomy. Study of 1134 mitral patients 20 years later]

With a test sample (n = 323), consisting of the answers to an inquiry about the patients with operated mitral stenosis (n = 1134), between 1952 and 1978, in "Hospital Pulido Valente", Lisbon, we compared the group of survivors with the decreased in the relation to sex, age, valvular lesion, type of surgery, valvular area before and after surgery and existence of incompetence. We concluded that mitral stenosis was more frequent in females (4/1), but it had a worse prognosis in males. The lower the age at the time of surgery the better long time prognosis. Digital and instrumental valvulotomy had similar mortality. Valvular incompetence had a worse prognosis and is associated with larger valvular area.

[Epidemiologic study of bovine and human leptospirosis in eastern Brazilian Amazon]

The seroprevalence study for leptospirosis in bovines and humans was realized in family holder farms along the Transamazon Highway. The prevalence of bovine leptospirosis was 97% [90.9 - 99.5%] of farms with at least one positive animal according to microscopic agglutination test for the leptospirosis diagnostic. In 61.2% of the tested herds, the serovar hardjo was the most common, followed by the serovar bratislava (9%) and the serovar shermani (4.5%). The serologic prevalence of leptospirosis in humans was 32.8% [23.4 - 43.5%] in family groups with at least one positive individual according to microscopic agglutination test for the leptospirosis diagnostic. In 9% of family groups, the serovar bratislava was the most common, while serovar hardjo and grippotyphosa accounted for 6% and 4.5%, respectively. The impact of these results is discussed in relation to animal production and public health. Suggestions have been proposed in order to improve the situation in the region.

Production of capsular polysaccharide of Streptococcus pneumoniae type 14 and its purification by affinity chromatography

We describe a rapid and efficient method for producing the capsular polysaccharide of Streptococcus pneumoniae by fermentation on tryptic soy broth and purification of this compound by using immobilized soybean lectin as an affinity adsorbent. In principle, the same strategy can be used to produce purified capsular polysaccharides from other streptococcal serotypes by selecting the appropriate lectin adsorbents.