Extracellular components in enteroaggregative Escherichia coli biofilm and impact of treatment with proteinase K, DNase or sodium metaperiodate.

Enteroaggregative E. coli (EAEC) is a major cause of diarrhea worldwide. EAEC are highly adherent to cultured epithelial cells and make biofilms. Both adherence and biofilm formation rely on the presence of aggregative adherence fimbriae (AAF). We compared biofilm formation from two EAEC strains of each of the five AAF types. We found that AAF type did not correlate with the level of biofilm produced. Because the composition of the EAEC biofilm has not been fully described, we stained EAEC biofilms to determine if they contained protein, carbohydrate glycoproteins, and/or eDNA and found that EAEC biofilms contained all three extracellular components. Next, we assessed the changes to the growing or mature EAEC biofilm mediated by treatment with proteinase K, DNase, or a carbohydrate cleavage agent to target the different components of the matrix. Growing biofilms treated with proteinase K had decreased biofilm staining for more than half of the strains tested. In contrast, although sodium metaperiodate only altered the biofilm in a quantitative way for two strains, images of biofilms treated with sodium metaperiodate showed that the EAEC were more spread out. Overall, we found variability in the response of the EAEC strains to the treatments, with no one treatment producing a biofilm change for all strains. Finally, once formed, mature EAEC biofilms were more resistant to treatment than biofilms grown in the presence of those same treatments.

Removal of tetramethylammonium hydroxide (TMAH) by cold plasma treatment combined with periodate oxidation: Degradation, kinetics, and toxicity study.

Tetramethylammonium hydroxide (TMAH), which is a chemical used in the electronic industry, is classified as a hazardous material (HAZMAT class 8) that threatens aquatic ecosystems and human health. Consequently, numerous studies have attempted to remove TMAH using various treatment methods, including advanced oxidation processes such as ozone, UV, or Fenton oxidation. However, prior research has indicated a low kinetic rate of TMAH removal. In this context, we proposed an alternative to TMAH degradation by combining a cold plasma (CP) process with periodate oxidation. As for the kinetics of TMAH removal, the kinetic constant was improved by 5 times (0.1661 and 0.0301 for 40.56 and 2.2 W, respectively) as the electric power of a CP system increased from 2.2 to 40.56 W. The kinetic constant of a 40.56 W CP system further increased by 54 times (1.6250) than a 2 W CP system when 4 mM periodate was used simultaneously. As a result, the integrated CP/periodate system represented 2 times higher TMAH removal efficiency (29.5%) than a 2 W CP system (14.4%). This excellent TMAH degradation capability of the integrated CP/periodate system became pronounced at pH 10 and 25 °C. Overall, the integrated CP/periodate system is expected to be a viable management option for effectively controlling hazardous TMAH chemicals.

Periodate oxidation of nanofibrillated cellulose films for active packaging applications.

An alternative packaging material based on cellulose that possesses excellent barrier properties and is potentially useful for active packaging has been developed. Cellulose nanofibril was efficiently and selectively oxidized with sodium periodate generating reactive aldehyde groups. These groups formed hemiacetal and hemialdal bonds during film formation and, consequently, highly transparent, elastic and strong films were created even under moisture saturation conditions. The periodate oxidation treatment additionally decreased the polarity of the films and considerably enhanced their water barrier properties. Thus, the water contact angle of films treated for 3 and 6 h was 97° and 102°, their water drop test value was higher than in untreated film (viz., 138 and 141 min with 3 and 6 h of treatment) and their water vapour transmission rate was substantially better (3.31 and 0.78 g m-2 day-1 with 3 and 6 h, respectively). The presence of aldehyde groups facilitated immobilization of the enzyme laccase, which efficiently captures oxygen and prevents food decay as a result. Laccase-containing films oxidized 80 % of Methylene Blue colorant and retained their enzymatic activity after storage for 1 month and 12 reuse cycles, opening the door to the possible creation of a reusable packaging to replace the single-use packaging.

Effects of cold plasma pretreatment combined with sodium periodate on property enhancement of dialdehyde starch prepared using native maize starch.

This study represents the inaugural investigation into the effect of cold plasma (CP) pretreatment combined with sodium periodate on the preparation of dialdehyde starch (DAS) from native maize starch and its consequent effects on the properties of DAS. The findings indicate that the maize starch underwent etching by the plasma, leading to an increase in the particle size of the starch, which in turn weakened the rigid structure of the starch and reduced its crystallinity. Concurrently, the plasma treatment induced cleavage of the starch molecular chain, resulting in a decrease in the viscosity of the starch and an enhancement of its fluidity. These alterations facilitated an increased contact area between the starch and the oxidising agent sodium periodate, thereby augmenting the efficiency of the DAS preparation reaction. Consequently, the aldehyde group content was elevated by 9.98 % compared to the conventional DAS preparation methodology. Therefore, CP could be an efficient and environmentally friendly non-thermal processing method to assist starch oxidation for DAS preparation and property enhancement.

Natural pyrite-stimulative periodate activation: efficiency and mechanism study.

Natural pyrite (NP) is an alternative catalyst for wastewater purification via advanced oxidation processes (AOPs). However, the activation performance and mechanism of periodate (PI) by NP have not yet been revealed. Herein, this work examines the activation performance of NP towards PI and its application in the degradation of antibiotic wastewater. Interestingly, 95.69% of chlortetracycline (CTC) was degraded by NP within 20 min via PI activation. Besides, NP shows effective degradation of various pollutants such as rhodamine B (65.81%), sulfamethoxazole (89.04%), and sodium butylxanthate (99.77%) within 20 min. The active species quenching experiment suggested that the active species ∙ OH , IO 3 ∙ , 1O2 and the active complex of PI bonded with NP surface participated in CTC degradation. In addition, Fe(II) on NP surface is the main active site for PI activation, while Sn2- species accelerates the reduction of Fe(III) to Fe(II) and promotes sustained PI activation. This work provides new ideas for the application of NP in environmental pollution control.

Sustainable bioelectric activation of periodate for highly efficient micropollutant abatement.

The periodate (PI)-based advanced oxidation process is valued for environmental remediation, but current activation methods involve high costs, secondary contamination risks, and limited applicability due to external energy inputs (e.g., UV), catalyst incorporation (e.g., Fe2+), or environmental modifications (e.g., freezing). In this work, novel bioelectric activation of PI using the electrons generated by electroactive bacteria was developed and investigated for rapid removal of carbamazepine (CBZ), achieving 100 %, 100 %, and 76 % removal efficiency for 4.22 µM of CBZ in 20 min at pH 2, 120 min at pH 6.4, and HRT of 30 min at pH 8.5, respectively, with a 1 mM PI dose and without an input voltage. It was deduced that electrons derived from bacteria could directly activate PI using Ti mesh electrodes and generate •IO3 via single electron transfer under strongly acidic conditions (e.g., pH 2). Nevertheless, under weak alkaline conditions (e.g., pH 8.5), biogenic electrons indirectly activated PI by generating OH-via 4e-reduction at the Ti mesh cathode, resulting in the formation of •O2- and 1O2. In addition to the metal cathode, a carbon-based cathode finely modulates the 2e-reduction, yielding H2O2 and activating PI to mainly form •OH. Moreover, primarily non-toxic IO3- was produced during treatment, while no detectable reactive iodine species (HOI, I2, and I3-) were observed. Furthermore, the bioelectric activation of PI demonstrated its capability to remove various micropollutants present in secondary-treated municipal wastewater, showcasing its broad-spectrum degradation ability. This study introduces a novel, cost-effective, and environmentally friendly PI activation technique with promising applicability for micropollutant elimination in water treatment.

Simulated sunlight/periodate-triggered formation of toxic halogenated bisphenols in highly saline water.

Periodate (PI)-based oxidation using the activators, such as metal ions and light irradiation, has emerged as a feasible treatment strategy for the effective remediation of contaminated water and wastewater. Given the pervasive nature of PI residues and solar exposure during application, the role of solar light in remediating the challenging highly saline water matrices needs to be elucidated. In this study, bisphenol A (BPA) was selected as the targeted micropollutant, which can be efficiently eliminated by the simulated sunlight (SSL)/PI system in the presence of high-level Cl- (up to 846.0 mM) at pH 7.0. The presence of different background constituents of water, such as halides, nitrate, and dissolved organic matter, had no effect, or even accelerated BPA abatement. Particularly, the ubiquitous Br- or I- appreciably enhanced the BPA transformation efficiency, which may be ascribed to the generation of high-selective reactive HOBr or HOI. The in silico predictions suggested that the transformation products generated by halide-mediated SSL/PI systems via halogen substitutions showed greater persistence, bioaccumulation, and aquatic toxicity than BPA itself. These findings highlighted a widespread phenomenon during PI-based oxidative treatment of highly saline water, which needs special attention under solar light illumination.

Activation of periodate by biocarbon-supported multiple modified nanoscale iron for the degradation of bisphenol A in high-temperature aqueous solution.

As reported, the persistent toxic and harmful pollutant bisphenol A (BPA) from industrial emissions has been consistently found in aquatic environments inhabited by humans. Periodate (PI)-based advanced oxidation processes (AOPs) have been employed to degrade BPA, although activating PI proves more challenging compared to other oxidants. A novel nano iron metal catalyst, sulfided nanoscale iron-nickel bimetallic nanoparticle supported on biocarbon (S-(nFe0-Ni)/BC) was synthesized and utilized to activate PI for the removal of BPA. The morphology, structure, and composition of S-(nFe0-Ni)/BC were characterized using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy-energy dispersive spectrometer (SEM-EDS), and fourier-transform infrared spectrum (FTIR). The catalyst demonstrates an excellent ability to activate PI, achieving a BPA removal efficacy of 86.4%, accompanied by a 33% reduction in total organic carbon (TOC) in the {S-(nFe0-Ni)/BC}/PI system. BPA degradation exhibited a significant change at the 5-min mark. In the first stage (0-5 min), nonlinear dynamic fitting research, combined with scavenging experiments, unveiled the competitive degradation of pollutants primarily driven by iodate radical ( IO 3 · ), singlet oxygen 1 O 2 , and hydroxyl radical ( · OH ). The competitive dynamics aligned with the ExpAssoc model. The contribution rates of different active species during the second stage (5-120 min) were calculated. The contributions of main species to BPA removal follow the order of IO 3 · > 1 O 2 > · OH throughout the entire process. The influence of various parameters, such as the dosage of S-(nFe0-Ni)/BC, initial PI concentration, BPA concentration, pH, temperature, and the presence of coexisting anions, was also examined. Finally, a plausible reaction mechanism in the system is proposed, suggesting that the {S-(nFe0-Ni)/BC}/PI system involves a heterogeneous synergistic reaction occurring primarily on the surface of S-(nFe0-Ni)/BC. Therefore, this study proposes a promising approach for PI-based AOPs to degrade organic pollutants, aiming to mitigate the irreversible harm caused by such pollutants to organisms and the environment.

Structural characterization of a glycoprotein from white jade snails (Achatina Fulica) and its wound healing activity.

Snail mucus is rich in proteins and polysaccharides, which has been proved to promote wound healing in mice in our previous research. The aim of this study was to investigate the effective component in snail mucus that can exert the wound healing potential and its structural characterization. Here, the glycoprotein from the snail mucus (SM1S) was obtained by DEAE-Sepharose Fast Flow and Sephacryl S-300 columns. The structural characteristics of SM1S were investigated via chromatographic techniques, periodic acid oxidation, FT-IR spectroscopy and NMR spectroscopy. Results showed that SM1S was a glycoprotein with a molecular weight of 3.8 kDa (83.23 %), consists of mannose, glucuronic acid, glucose, galactose, xylose, arabinose, fucose at a ratio of 13.180:4.875:1043.173:7.552:1:3.501:2.058. In addition, the periodic acid oxidation and NMR analysis showed that SM1S contained 1,6-glycosidic bonds, and might also contain 1 â†’ 4 and 1 â†’ 2 glycosidic or 1 â†’ 3 glycosidic bonds. Furthermore, the migration experiment of human skin fibroblasts in vitro suggested that SM1S had a good effect to accelerate the scratch healing of cells. This study suggested that SM1S may be a prospective candidate as a natural wound dressing for the development of snail mucus products.

Specialized digestive mechanism for an insect-bacterium gut symbiosis.

In Burkholderia-Riptortus symbiosis, the host bean bug Riptortus pedestris harbors Burkholderia symbionts in its symbiotic organ, M4 midgut, for use as a nutrient source. After occupying M4, excess Burkholderia symbionts are moved to the M4B region, wherein they are effectively digested and absorbed. Previous studies have shown that M4B has strong symbiont-specific antibacterial activity, which is not because of the expression of antimicrobial peptides but rather because of the expression of digestive enzymes, mainly cathepsin L protease. However, in this study, inhibition of cathepsin L activity did not reduce the bactericidal activity of M4B, indicating that there is an unknown digestive mechanism that renders specifically potent bactericidal activity against Burkholderia symbionts. Transmission electron microscopy revealed that the lumen of symbiotic M4B was filled with a fibrillar matter in contrast to the empty lumen of aposymbiotic M4B. Using chromatographic and electrophoretic analyses, we found that the bactericidal substances in M4B existed as high-molecular-weight (HMW) complexes that were resistant to protease degradation. The bactericidal HMW complexes were visualized on non-denaturing gels using protein- and polysaccharide-staining reagents, thereby indicating that the HMW complexes are composed of proteins and polysaccharides. Strongly stained M4B lumen with Periodic acid-Schiff (PAS) reagent in M4B paraffin sections confirmed HMW complexes with polysaccharide components. Furthermore, M4B smears stained with Periodic acid-Schiff revealed the presence of polysaccharide fibers. Therefore, we propose a key digestive mechanism of M4B: bacteriolytic fibers, polysaccharide fibers associated with digestive enzymes such as cathepsin L, specialized for Burkholderia symbionts in Riptortus gut symbiosis.

Highly efficient degradation of acetaminophen via nano zero-valent iron biochar with periodate system at low temperature.

The development of more efficient advanced oxidation systems for serving various advanced treatment of wastewater is quite necessary and urgent. In this study, a nano-zero valent iron/periodate (nZVI-BC/PI) advanced oxidation system has been constructed, achieving a rapid degradation of acetaminophen (ACT, 1 mg/L) within 1 min (100 % at pH = 11) at low temperature (5℃). This system shows a great degradation in a wide range of pH (1 âˆ¼ 11), improving the pH limitation of PI oxidation system. During the reaction process, ·OH as the main active species collaborate with 1O2, Fe (IV), ·O2- and electron transfer to degrade ACT. In this system, iron ion leaching is low (0.019 mg/L), ACT was effectively degraded (74.36 %∼97.32 %) under different water, moreover, the material has an expected recyclability. The research provides a significant guidance for the advanced treatment of wastewater especially in cold regions.

Efficient degradation of antibiotic wastewater by biochar derived from water hyacinth stems via periodate activation: pyridinic N and carbon structures improved the electron transfer process.

Biochar-activated periodate (PI) is a promising technology toward antibiotic wastewater purification. However, the mechanism of pyrolysis temperature on PI activation efficiency by biochar has not yet been revealed. Herein, this work selected water hyacinth stems as raw materials to prepare biochar with different pyrolysis temperatures (400, 500, 600, and 700 °C), and applied it to degrade tetracycline (TC) wastewater through PI activation. The results show that biochar with a pyrolysis temperature of 700 °C (BC-700) possesses the best TC degradation performance (∼100% within 30 min). Besides, the degradation of TC by BC-700 is less interfered by coexisting anions and water matrix, and exhibits good reusability. Quenching experiments and open circuit voltage tests verified that IO3•, 1O2, and reactive complex BC-PI* are active species involved in TC degradation. In addition, by constructing the relationship between biochar surface properties and degradation rate kobs, it was revealed that the dominant role of pyridinic N in PI adsorption and formation of reactive complexes as well as the promotion of sp2-hybridized carbon in the electron transfer process. This work provides novel insights into the application of biochar in antibiotic wastewater treatment via PI activation.

Recent advances on the preparation conditions, structural characteristics, physicochemical properties, functional properties and potential applications of dialdehyde starch: A review.

Starch, a natural storage polysaccharide of plant kingdom, has many industrial applications. However, native starch has some inherent shortages, which can be overcome by structural modification. Dialdehyde starch, one kind of oxidized starch produced by periodate oxidation, has good physical properties and bioactivities with wide applications in different fields. Dialdehyde starch is typically achieved by oxidizing native starch slurry through periodate oxidation under controlled reaction conditions. Several factors including the source of starch, the type of oxidant, the molar ratio of oxidant to starch, reaction temperature, reaction time and solution pH value can influence the synthesis of dialdehyde starch. Dialdehyde starch shows different spectroscopic/chromatographic characters and physicochemical properties from native starch. Moreover, dialdehyde starch exhibits good antioxidant activity, antimicrobial activity and cross-linking property. Based on these functional properties, dialdehyde starch has shown application potentials in food packaging, thermoplastic production, enzyme immobilization, heavy metal ion adsorption, drug delivery, wood adhesion and leather tanning. In this review, the preparation conditions, structural characteristics, physicochemical properties, functional properties and potential applications of dialdehyde starch are summarized for the first time. The future research and development prospects of dialdehyde starch are also discussed.

o-Semiquinone Radical and o-Benzoquinone Selectively Degrade Aniline Contaminants in the Periodate-Mediated Advanced Oxidation Process.

Advanced oxidation processes (AOPs) often employ strong oxidizing inorganic radicals (e.g., hydroxyl and sulfate radicals) to oxidize contaminants in water treatment. However, the water matrix could scavenge the strong oxidizing radicals, significantly deteriorating the treatment efficiency. Here, we report a periodate/catechol process in which reactive quinone species (RQS) including the o-semiquinone radical (o-SQ•-) and o-benzoquinone (o-Q) were dominant to effectively degrade anilines within 60 s. The second-order reaction rate constants of o-SQ•- and o-Q with aniline were determined to be 1.0 × 108 and 4.0 × 103 M-1 s-1, respectively, at pH 7.0, which accounted for 21% and 79% of the degradation of aniline with a periodate-to-catechol molar ratio of 1:1. The major byproducts were generated via addition or polymerization. The RQS-based process exhibited excellent anti-interference performance in the degradation of aniline-containing contaminants in real water samples in the presence of diverse inorganic ions and organics. Subsequently, we extended the RQS-based process by employing tea extract and dissolved organic matter as catechol replacements as well as metal ions [e.g., Fe(III) or Cu(II)] as periodate replacements, which also exhibited good performance in aniline degradation. This study provides a novel strategy to develop RQS-based AOPs for the highly selective degradation of aniline-containing emerging contaminants.

Clear cell urothelial carcinoma of bladder: Case report of a rare and aggressive variant with review of literature.

Clear cell urothelial carcinoma is a rare variant of urothelial carcinoma. It's recognition and accurate diagnosis are essential in deciding appropriate treatment protocols considering the prognosis of this variant. A 57-year-old male presented with a history of hematuria and lower urinary tract symptoms for 6 months. Microscopically, the tumor was arranged in sheets and had a nested pattern. The tumor was composed of round to polygonal cells with abundant clear cytoplasm (>90% clear cell differentiation), resembling a conventional clear renal cell carcinoma. On special stain, the tumor was positive for periodic acid-Schiff (PAS) and negative for periodic acid-Schiff with diastase (PAS-D) and mucicarmine stain. The urothelial origin of clear cells was confirmed by positivity for GATA Binding protein 3(GATA3) and High Molecular Weight Cytokeratin (HMWCK) immunohistochemistry and negativity for NK3 homeobox 1(NKX3.1), Prostate specific antigen (PSA) and Paired box gene 8 (PAX8) immunohistochemistry.

Characterization and bioactivities of a novel polysaccharide obtained from Gracilariopsis lemaneiformis

ABSTRACT Gracilariopsis lemaneiformis is a type of red alga that contains seaweed polysaccharide agar. In this study, a novel non-agar seaweed polysaccharide fraction named GCP (short of crude polysaccharide obtained from Gracilariopsis lemaneiformis) was isolated from Gracilariopsis lemaneiformis. Structural analysis showed that GCP shows triple helical chain conformation when dissolved in water and has many branches and long side chains. Also, 1→3 linkage is the major linkage and the sugar structures are galactopyranose configurations linked by β-type glycosidic linkages. Two macromolecular substance fractions (GCP-1 and GCP-2) were purified by DEAE Sepharose Fast Flow column chromatography. Moreover, a splenocyte damage assay and splenocyte proliferation assay were used to analyse the bioactivities of GCP, GCP-1 and GCP-2. It was demonstrated that polysaccharides could protect splenocyte damaged by H2O2; GCP-2 shows a greatest protection rate, that is, 92.8%, which significantly enhanced the splenocyte proliferation, and GCP showed the highest proliferation rate, 9.30%. The results suggested that this type of novel non-agar polysaccharide displayed remarkable antioxidant and immunomodulatory activities and early alkali treatment could decrease the activities. It may represent a potential material for health food and clinical medicines.

Doenças do sistema nervoso de bovinos no semiárido nordestino / Diseases of the nervous system of cattle in the semiarid of Northeastern Brazil

Para determinar as doenças que ocorrem no sistema nervoso de bovinos no semiárido nordestino, foi realizado um estudo retrospectivo em 411 necropsias de bovinos realizadas no Hospital Veterinário da Universidade Federal de Campina Grande, Patos, Paraíba, entre janeiro de 2000 a dezembro de 2008. Dos 411 casos analisados 139 (33,81 por cento) apresentaram alterações clínicas do sistema nervoso e as fichas foram revisadas para determinar os principais achados referentes à epidemiologia, aos sinais clínicos e às alterações macroscópicas e microscópicas. Em 28 (20,14 por cento) casos o diagnóstico foi inconclusivo. As principais enfermidades foram raiva (48,7 por cento dos casos com sinais nervosos), abscessos cerebrais (7,2 por cento) incluindo três casos de abscesso da pituitária, febre catarral maligna (6,3 por cento), botulismo (6,3 por cento), alterações congênitas (4,5 por cento), traumatismo (4,5 por cento), tuberculose (2,7 por cento), tétano (2,7 por cento), infecção por herpesvírus bovino-5 (2,7 por cento), encefalomielite não supurativa (2,7 por cento), intoxicação por Prosopis juliflora (2,7 por cento), status spongiosus congênito de causa desconhecida (1,8 por cento) e polioencefalomalacia (1,8 por cento). Outras doenças diagnosticadas numa única oportunidade (0,9 por cento) foram criptococose, listeriose, encefalite tromboembólica, linfossarcoma, tripanossomíase e babesiose por Babesia bovis.

Diseases of the nervous system of cattle in the semiarid region of northeastern Brazil were evaluated by a retrospective study of 411 cattle necropsies performed in the Veterinary Hospital of the Federal University of Campina Grande, Patos, Paraíba, from January 2000 to December 2008. Of the 411 cases analyzed, 139 (33.81 percent) were from cattle that presented nervous signs and the records were reviewed to determine the epidemiological, clinical, and macroscopic and histologic main features. Diagnosis was inconclusive in 28 cases (20.14 percent). In cases with diagnosis the main diseases were rabies (48.7 percent of the cases with nervous signs), brain abscesses (7.2 percent) including three cases of pituitary abscesses, malignant catarrhal fever (6.3 percent), botulism (6.3 percent), congenital malformations (4.5 percent), trauma (4.5 percent), tuberculosis (2.7 percent), tetanus (2.7 percent), infection by bovine hervesvirus-5 (2.7 percent), non-suppurative encephalomyelitis (2.7 percent), intoxication by Prosopis juliflora (2.7 percent), congenital status spongiosus of unknown etiology (1.8 percent), and polioencephalomalacia (1.8 percent). Other diseases diagnosed only once (0.9 percent) were cryptococcosis, listeriosis, thromboembolic encephalitis, lymphosarcoma, trypanosso-miasis, and babesiosis by Babesia bovis.

Human serum antibody reactivity towards Paracoccidioides brasiliensis antigens treated with sodium metaperiodate / Reatividade de anticorpos de soros humanos a antígenos de Paracoccidioides brasiliensis tratados com metaperiodato sódico

In this study, we evaluated the profile of anti-Paracoccidioides brasiliensis immunoglobulin isotypes in serum from patients with the acute and chronic forms of paracoccidioidomycosis, using the whole Paracoccidioides brasiliensis antigen and the antigen treated with sodium metaperiodate. All the immunoglobulin isotypes present in the serum from patients with the acute and chronic forms of paracoccidioidomycosis presented higher reactivity towards the whole antigen than to the antigen treated with metaperiodate (P < 0.05). The reactivity of IgG and IgM to the antigen treated with metaperiodate was greater in serum from patients with the acute form of the disease (P < 0.05), while IgA was more reactive in serum from patients with the chronic form (P < 0.05). There was greater reactivity of IgG1 and IgG2 to the whole antigen and the antigen treated with metaperiodate in the serum from patients with paracoccidioidomycosis than there was in serum from patients with other parasitic infections (P < 0.05). Furthermore, IgG1 from patients with the acute form recognized the 19kDa, 27kDa and 31kDa antigens in the western blot test. Thus, the results suggest that modifications to the epitopes of Paracoccidioides brasiliensis antigens may help to improve the immunodiagnosis of paracoccidioidomycosis.

Neste trabalho, foi avaliado o perfil de isotipos de imunoglobulinas anti-Paracoccidioides brasiliensis em soros de pacientes com formas crônica e aguda de paracoccidiodomicoses usando antígeno total e tratado com meta-periodato. Todos os tipos de imunoglobulinas presentes nos soros de pacientes com formas aguda e crônica apresentaram alta reatividade ao antígeno total quando comparado ao tratado com meta-periodato (P < 0,05). Houve maior reatividade de IgG e IgM anti-antígeno tratado com meta-periodato em soros de pacientes com forma aguda da doença (P < 0,05), enquanto IgA foi mais reativa em soros da forma crônica (P < 0,05). Houve maior reatividade de IgG1 e IgG2 com antígeno total e tratado com meta-periodato em soros de pacientes comparados aos com outras parasitoses (P < 0,05). Além disso, IgG1 de pacientes com a forma aguda reconhecem antígenos de 19kDa, 27kDa e 31kDa por western blot. Assim, os resultados sugerem que alterações nos epitopos de antígenos de Paracoccidioides brasiliensis podem auxiliar no aprimoramento do imunodiagnóstico da paracoccidioidomicose.

Immunization of Balb/c mice with modified auto-antigens for induction of autoimmune sialoadenitis

Sjögren's syndrome is an autoimmune disease characterized by sialoadenitis and elevated titers of autoantibodies. To assess whether it is possible to induce inflammatory changes in salivary gland tissues, a series of immunizations in Balb/c mice have been undertaken, using salivary gland extract, modified or not, added to several adjuvants. Mice's humoral immune response to salivary gland antigens was monitored by ELISA. Inflammatory cells infiltrating gland tissue were seen 3 months after immunization with salivary gland extract modified with pepsin (AgGp) and metaperiodate (AgGMp). Although pathological progression was not observed, the histopathological picture was similar to the initial phase of Sjõgren's syndrome. In addition, a monoclonal antibody reactive with 3 gland polypeptides and anhydrase carbonic II was rescued among B cells from immunized mice. Thus, immunizations with modified autoantigens were able to initiate pathological damage to glandular tissue and stimulate the proliferation of auto-reactive B cells.

A Síndrome de Sjögren é uma doença auto-imune caracterizada por desenvolvimento de sialoadenite e títulos elevados de auto-anticorpos. Com o objetivo de induzir alterações inflamatórias no tecido das glândulas salivares foram realizadas várias imunizações em camundongos BALB/c utilizando extratos de glândulas salivares, modificados ou não, em vários adjuvantes. A resposta humoral para antígenos salivares foi monitorada por ELISA. Células inflamatórias infiltrando o tecido glandular foram vistas 3 meses pós-imunização com extrato de glândula salivar modificado com pepsina (AgGp) e metaperiodato (AgGMp). Embora a evolução patológica não tenha sido observada, o quadro histopatológico foi semelhante à fase inicial da Síndrome de Sjõgren. Também foi possível notar, a partir das células B dos animais imunizados, a produção de anticorpos monoclonais reativos com 3 polipeptídeos glandulares e anidrase carbônica II. Assim, a imunização com auto-antígenos glandulares modificados foi capaz de iniciar o processo patológico no tecido glandular e induzir a proliferação de células B produtoras de auto-anticorpos.

Presença de fungos na dentina humana: implicações arqueológicas e forenses / Fungal infiltration in the human dentine: archaeology and forensic implications

Quando se encontram remanescentes humanos, algumas questões sobre a identificação são levantadas e uma das primeiras diz respeito à antiguidade do material. A distinção entre amostras recentes e arqueológicas pode ser feita pela identificação ou não de fungos na dentina humana através da técnica histoquímica do PAS (periodic acid Schiff). Para validar esta técnica, avaliamos três amostras diferentes. A primeira composta de dentes de um indivíduo com datação de 2640 anos antes da data presente. A segunda composta de dentes com idades de 69, 67, 48 e 36 anos. A terceira refere-se a dois dentes extraídos recentemente. Na amostra mais antiga observou-se a presença de inúmeras estruturas filamentosas compatíveis com hifas de fungos no interior dos túbulos dentinários. Estes resultados apontam a presença dessas estruturas na dentina como um indicativo de que o material não tem origem recente. A técnica utilizada é um recurso de baixo custo e rápidos resultados para uma primeira classificação e distinção dos remanescentes humanos.