Heterocyclic chalcone (E)-1-(2-hydroxy-3,4,6-trimethoxyphenyl)-3-(thiophen-2-yl) prop-2-en-1-one derived from a natural product with antinociceptive, anti-inflammatory, and hypoglycemic effect in adult zebrafish

Diabetes is a disease linked to pathologies, such as chronic inflammation, neuropathy, and pain. The synthesis by the Claisen-Schmidt condensation reaction aims to obtain medium to high yield chalconic derivatives. Studies for the synthesis of new chalcone molecules aim at the structural manipulation of aromatic rings, as well as the replacement of rings by heterocycles, and combination through chemical reactions of synthesized structures with other molecules, in order to enhance biological activity. A chalcone was synthesized and evaluated for its antinociceptive, anti-inflammatory and hypoglycemic effect in adult zebrafish. In addition to reducing nociceptive behavior, chalcone (40 mg/kg) reversed post-treatment-induced acute and chronic hyperglycemia and reduced carrageenan-induced abdominal edema in zebrafish. It also showed an inhibitory effect on NO production in J774A.1 cells. When compared with the control groups, the oxidative stress generated after chronic hyperglycemia and after induction of abdominal edema was significantly reduced by chalcone. Molecular docking simulations of chalcone with Cox -1, Cox-2, and TRPA1 channel enzymes were performed and indicated that chalcone has a higher affinity for the COX-1 enzyme and 4 interactions with the TRPA1 channel. Chalcone also showed good pharmacokinetic properties as assessed by ADMET.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13205-023-03696-8.

Assessing the effect of antimony pressure on trypanothione reductase activity in Leishmania (Viannia) braziliensis

Leishmania parasites have an oxidative and chemical defense mechanism called trypanothione system (T[SH]₂), the most abundant thiol system in trypanosomatids. This system has a central role in processing pentavalent antimony and resistance has been related to a better capacity to metabolize it through the activation of T[SH]₂ enzymatic cascade. A biochemical approach was applied to assess the effect of trivalent (Sb^III) and pentavalent antimony (Sb^V) on Trypanothione Reductase (TR) activity of two Leishmania (Viannia) braziliensis clinical isolates, which were labeled as responder (R) and non-responder (NR) after patient treatment with Glucantime®. Both isolates were characterized based on in vitro susceptibility to Sb^III and Sb^V and trypanothione reductase (TR) activity. Sb^III and Sb^V discriminated susceptibility profiles in all parasite forms, since isolate NR had significantly higher EC₅₀ values than isolate R. Differences were observed in TR activity between promastigotes, axenic amastigotes and intracellular amastigotes: R (0.439 ± 0.009, 0.103 ± 0.01 and 0.185 ± 0.01AU.min^-1.μg of protein^-1) and NR (1.083 ± 0.04, 0.914 ± 0.04 and 0.343 ± 0.04 AU. min^-1.μg of protein^-1), respectively. Incubation with Sb^III and Sb^V using each form EC₅₀ value caused a time-dependent differential effect on TR activity suggesting that oxidative defense is related to the antimony susceptibility phenotype. Data gathered here shows a biochemical approach able to discriminate two L. (V.) braziliensis clinical isolates measurements TR activity of promastigotes, axenic amastigotes and intracellular amastigotes.

Methods of Microencapsulation of Vegetable Oils: Principles, Stability and Applications - A Minireview

In addition to being used in food, fuel and lubricants, vegetable oils are promising in many other applications such as food additives, nutritional supplements, cosmetics and biomedicine; however, their low oxidative stability can limit their use. Microencapsulation is a well-established method for the preservation of oil against degradation, controlled release of active ingredients, protection against external factors during storage, and enhanced durability. In this article, microencapsulation methods for vegetable oil are reviewed, including physical methods (spray-drying and freeze-drying), physicochemical methods (complex coacervation, ionic gelation and electrostatic layer-by-layer deposition), and chemical methods (interfacial/in situ polymerization). This article also provides information on the principles, parameters, advantages, disadvantages and applications of these methods.

Carnauba (Copernicia prunifera) palm tree biomass as adsorbent for Pb(II) and Cd(II) from water medium

Plant-based biomass (CFB (carnauba fruit biomass)) obtained from the fruit exocarp of the species Copernicia prunifera (Mill.) H.E. Moore (carnauba) was evaluated for its viability as an adsorbent of potentially toxic metals in aqueous medium. The CFB was characterized by powder X-ray spectroscopy (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and zeta potential to investigate the morphology of the biosorbent and its interaction with water soluble metal ions of Pb and Cd. The biomass presents an amorphous structure, with negative zeta potential (- 2.59 mV), and the presence of functional groups such as O-H, C-O-C, C-H, and C=O. The removal potential of Pb(II) and Cd(II) was performed in a batch system, and monoelement solutions were tested to assess the effects of adsorbent dose and initial metal ion concentration, pH at the point of zero charge (pH_PZC), sorption kinetics, and adsorption capacity. The most appropriate adsorbent concentration was 5 g/L, and sorption studies were carried out at pH 5.0 (pH_PZC = 4.68), in which the surface of the adsorbent shows negative charges and favors the adsorption of metal ions. Kinetic studies showed that the pseudo-second order model best fit the experimental data, and equilibrium was reached at 120 min of contact time. The experimental sorption capacity (SC_exp) for Pb and Cd was around 28 and 34 mg/g, respectively, and six different non-linear isotherm models were used to describe the sorption phenomena, among them, four with 2 parameters, i.e., Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich (DR), respectively, and two with 3 parameters, namely, SIPS and Hill. The non-linear Temkin and Freundlich isotherm models best fit the experimental data for Pb(II) and Cd(II), respectively. According to the Langmuir model, Q_max was 26 mg/g and 58 mg/g for Pb(II) and Cd(II), respectively, indicating the efficiency of CFB as a new alternative to conventional methods for the removal of potentially toxic metals from aqueous medium.

Pequi oil microencapsulation by complex coacervation using gelatin-cashew gum

New functional foods and beverages can be developed using bioactive compounds present in pequi oil. Complex coacervation is an encapsulation method used for preserving bioactive molecules, especially those that are hydrophobic or sensitive to high temperatures. The objective of this work was to produce and characterize pequi oil microparticles using cashew gum/gelatin matrix (CG/GE) through complex coacervation. Gum Arabic (GA) was also studied in comparison with CG. The coacervation process was performed withoutpequi oil to determine the ideal proportions of the matrix components, followed by the embedding of the oil inthe microparticles for evaluation. Satisfactory microparticles were produced at pH 4.5 in the weight ratios of CG/GE = 2:1 and GA/GE = 1:3. Pequi oil release was greater in acidic pH, especially at pH 2 for the CG/GE matrix. The encapsulation efficiency for CG/GE and GA/GE was 72.53% (±4.80) and 82.77% (±6.09), respectively. The results showed that the CG/GE combination seemed very promising as anencapsulation matrix, especially for food applications involving pH values higher than 3.

Preparation and characterization of carboxymethyl cashew gum grafted with immobilized antibody for potential biosensor application

This report details the design of carboxymethylated cashew gum (CG) as a platform for antibody (Ab) immobilization, which can then be used as a biosensor for bacteria detection. The CG was isolated and characterized, followed by conversion to carboxymethyl cashew gum (CMCG). The CMCG film was a viable support for antibody immobilization; it was electrodeposited on gold surface using the cyclic voltammetry technique, applying a potential sweep from -1.0 V to 1.3 V with a scan rate of 50 mV s^-1 and 10 scans. The COOH groups on the surface of the film were critical in promoting Ab bonding. The immobilization of the Ab was mediated by protein A (PrA) for recognition of the antigen. Voltammetry studies were used to monitor the antibody immobilization. Finally, the analytical response of the CMCG-PrA-Ab system was evaluated with the chronoamperometry technique and was found to detect Salmonella Typhimurium bacteria rapidly and efficiently.

Biossensor amperométrico para determinação de peróxido de hidrogênio em leite

Um biossensor amperométrico foi desenvolvido para detecção de peróxido de hidrogênio em amostras de leite. O biossensor foi construído a partir da imobilização de enzima peroxidase sobre eletrodo impresso de carbono. Parâmetros de otimização visando um melhor desempenho do biossensor foram avaliados. O biossensor apresentou linearidade no intervalo de 5,0 a 40,0 µ mol L-1 de H2O2 em tampão fosfato. Em amostras de leite sem diluição, os limites de detecção e quantificação foram de 0,42 µmol L-1 e 1,39 µmol L-1, respectivamente. O biossensor mostrou-se uma alternativa sensível e de baixo custo na detecção de H2O2 em amostras adulteradas de leite.

Resistance of Klebsiella Pneumoniae clinical isolates: linkage of outer membrane proteins (omps) with production esbls

Three isolates of Klebsiella pneumoniae, collected from the University Hospital in Fortaleza, Brazil, were analyzed to determine their resistance to multiple antibiotics. The results of this study showed that the resistance of the clinically isolated bacteria is associated with the production of extended-spectrum beta-lactamases (ESLBs) and loss of outer membrane proteins.

[Spatial distribution and breeding site characteristics of Aedes albopictus and Aedes aegypti in Fortaleza, State of Ceará]

INTRODUCTION

Since the registration of Aedes albopictus in the municipality of Fortaleza in 2005, it has shown rapid dispersion. A study aiming to identify its occurrence areas, breeding sites and associations with Aedes aegypti and other culicids was carried out during 2008.

METHODS

Between January and July 2008, samples of immature forms of culicids were gathered from properties located in districts of Fortaleza. Certain features of the breeding sites were highlighted, such as location (indoors or outdoors), presence of covering (protection against impact of sunlight and rain), water turbidity (water clear or not clear), constituent material, volume, height above ground level and simultaneous presence of different species of culicids in the same breeding site.

RESULTS

Indoor location was an important factor for the breeding sites for Aedes albopictus [PR = 0.52; 95% CI: 0.33-0.81]. On the other hand, water turbidity and reservoir covering were not shown to be differentiators regarding infestation [p > 0.05]. Absence of water turbidity was significant for Aedes aegypti infestation in breeding sites [PR = 1.14; 95% CI: 1.06-1.22].

CONCLUSIONS

Absence of one of the species from the breeding sites enhanced the infestation by another species. Breeding sites that had not been infested by Aedes albopictus had a prevalence of infestation by Aedes aegypti that was 2.05 times greater [95% CI: 1.72-2.44]. There was no significant association between volume and height of the breeding sites and infestation by both species. Both species were found to be dispersed throughout the municipality, occupying a wide diversity of breeding sites. However, a slight physical separation could be identified, with higher infestation with Aedes albopictus outdoors.

Heparin binding proteins from Leishmania (Viannia) braziliensis promastigotes

We have examined the heparin binding proteins from Leishmania (Viannia) braziliensis promastigotes (HBP-Lb) by chromatography assays. The proposed strategy to isolate an enriched fraction of the HBP-Lb consisted of an association of the Triton X-114 method with affinity chromatography in heparin-Sepharose 4B column. SDS-PAGE analysis of the eluted proteins showed two main protein bands (65.0 and 54.5 kDa), while a single protein band was observed in native electrophoresis gel. The hemagglutination property of HBP-Lb over rabbit erythrocytes was confirmed up to 6.3+/-0.5 microg of protein mL(-1). Additionally, we have assayed the potential of HBP-Lb labeled with sulfo-NHS-LC-biotin in binding to nitrocellulose-immobilized gut proteins extracted of Lutzomyia intermedia and Lutzomyia whitmani. The results indicated a similar profile of five ligands (67.0, 62.1, 59.5, 56.0 and 47.5 kDa) in both studied Lutzomyia species. This is the first direct description of this class of protein in L. (V.) braziliensis with a suggestion of its biological activity in the interaction of Leishmania with Lutzomyia gut cells, which maybe a crucial step during this parasite's life cycle.

The main proteinases in Dermatobia hominis second and third instars larvae are serine-proteinases

We performed a combination of proteinase assay, either in solution or immobilized in sodium dodecyl sulfate-polyacrylamide gel copolymerized with gelatin, to detect and quantify proteinases of Dermatobia hominis second (L2) and third (L3) instar larvae. In the quantitative assay, we examined proteinase activity by hydrolysis of a panel of peptide bonds specific for the main proteinase classes. We verified that the pGlu-Phe-Leu p-nitroanilide substrate was hydrolyzed by crude extracts of L2 (3.0+/-0.2 nmol h(-1)mg of protein(-1)) and L3 (7.7+/-0.1 nmol h(-1)mg of protein(-1)) and that both activities were partially inhibited by trans-epoxysuccinyl-l-leucylamido-(4-guanidino)butane, 15% and 3%, respectively. Also, we demonstrated that the Nalpha-p-Tosyl-l-Arg methyl ester substrate was hydrolyzed by crude extracts of L2 (117+/-24 nmol h(-1)mg of protein(-1)) and L3 (111+/-10 nmol h(-1)mg of protein(-1)), suggesting a predominance of esterase activity in the crude larval preparation. Interestingly, the specific activity of serine-proteinases was totally inhibited by phenylmethylsulphonyl fluoride in the L3 crude extract, while only 10% of this enzyme class activity was inhibited in the L2 crude extract. The results of the qualitative assays with substrate gels suggested that L2 and L3 larvae express serine-proteinases with similar (13 and 22 kDa) and distinct (50 kDa in L2 and 30 kDa in L3) relative molecular masses. These findings contribute to the biochemical characterization of D. hominis L2 and L3 larvae.

Trypanosoma cruzi: attachment to perimicrovillar membrane glycoproteins of Rhodnius prolixus

Studies were carried out to identify proteins involved in the interface of Trypanosoma cruzi with the perimicrovillar membranes (PMM) of Rhodnius prolixus. Video microscopy experiments demonstrated high level of adhesion of T. cruzi Dm 28c epimastigotes to the surface of posterior midgut cells of non-treated R. prolixus. The parasites however were unable to attach to gut cells obtained from decapitated or azadirachtin-treated insects. The influence of carbohydrates on the adhesion to insect midgut was confirmed by inhibition of parasite attachment after midgut incubation with N-acetylgalactosamine, N-acetylmannosamine, N-acetylglucosamine, D-galactose, D-mannose or sialic acid. We observed that hydrophobic proteins in the surface of epimastigotes bind to polypeptides with 47.7, 45.5, 44, 43, 40.5, 36, 31 and 13kDa from R. prolixus PMM and that pre-incubation of lectins specifically inhibited binding to 31, 40.5, 44 and 45.5kDa proteins. We suggest that glycoproteins from PMM and hydrophobic proteins from epimastigotes are important for the adhesion of the parasite to the posterior midgut cells of the vector.

Trends in drug resistance, serotypes, and molecular types of Streptococcus pneumoniae colonizing preschool-age children attending day care centers in Lisbon, Portugal: a summary of 4 years of annual surveillance

Of the nasopharyngeal cultures recovered from 942 day care center (DCC) attendees in Lisbon, Portugal, 591 (62%) yielded Streptococcus pneumoniae during a surveillance performed in February and March of 1999. Forty percent of the isolates were resistant to one or more antimicrobial agents. In particular, 2% were penicillin resistant and 20% had intermediate penicillin resistance. Multidrug resistance to macrolides, lincosamides, and tetracycline was the most frequent antibiotype (17% of all isolates). Serotyping and molecular typing by pulsed-field gel electrophoresis were performed for 202 out of 237 drug-resistant pneumococci (DRPn). The most frequent serotypes were 6B (26%), 14 (22%), 19F (16%), 23F (10%), and nontypeable (12%). The majority (67%) of the DRPn strains were representatives of nine international clones included in the Pneumococcal Molecular Epidemiology Network; eight of them had been detected in previous studies. Fourteen novel clones were identified, corresponding to 26% of the DRPn strains. The remaining 7% of the strains were local clones detected in our previous studies. Comparison with studies conducted since 1996 in Portuguese DCCs identified several trends: (i) the rate of DRPn frequency has fluctuated between 40 and 50%; (ii) the serotypes most frequently recovered have remained the same; (iii) nontypeable strains appear to be increasing in frequency; and (iv) a clone of serotype 33F emerged in 1999. Together, our observations highlight that the nasopharynxes of children in DCCs are a melting pot of successful DRPn clones that are important to study and monitor if we aim to gain a better understanding on the epidemiology of this pathogen.

Leishmania amazonensis: early proteinase activities during promastigote-amastigote differentiation in vitro

Leishmania proteinase activity is known as parasite differentiation marker, and has been considered relevant for leishmanial survival and virulence. These properties suggest that Leishmania proteinases can be promising targets for development of anti-leishmania drugs. Here, we analyze the activities of four proteinases during the early phase of the Leishmania amazonensis promastigotes differentiation into amastigotes induced by heat shock. We have examined activities of cysteine-, metallo-, serine-, and aspartic-proteinase by hydrolysis of specific chromogenic substrates at pH 5.0 and at the optimal pH for each enzyme. Our results show that metallo-, serine-, and aspartic-proteinases activities were down-regulated during the shock-induced transformation of promastigotes into amastigotes. In contrast, cysteine-proteinase activity increased concomitantly with the promastigote differentiation. Immunocytochemical localization using two anti-cysteine-proteinase monospecific rabbit antibodies detected the enzyme in several cell compartments of both parasite stages. Our results show different proteinase activity modulation and expression during the early phases of the shock-induced parasite transformation.

Subcellular localization of an extracellular serine protease in Leishmania (Leishmania) amazonensis

Extracellular proteolytic activity was detected in a Leishmania ( L.) amazonensis culture supernatant and a 56-kDa protein was purified using (NH4)2SO4 precipitation followed by affinity chromatography on aprotinin-agarose. A rabbit serum obtained against the 56-kDa extracellular serine protease was used in order to analyze its location in L. ( L.) amazonensis parasites. Immunocytochemistry studies revealed that the enzyme is mainly found in the flagellar pocket and cytoplasmic vesicles of promastigote forms, whereas in amastigotes, it is located in electron-dense structures resembling megasomes. These results indicate that the 56-kDa serine protease is released into the extracellular environment through the flagellar pocket; and its intracellular location suggests either a correlated enzymatic activity or intracellular trafficking.

Th1 and Th2 immunological profile induced by cysteine proteinase in murine leishmaniasis

This study evaluated the immune response to three synthetic peptides (pI, VMVEQVICFD; pII, VGGGLCFE; pIII, PYFLGSIMNTCHYT) from the COOH-terminal region of Leishmania amazonensis cysteine proteinases, in BALB/c- and CBA-infected mice with this parasite. Only BALB/c mice, previously inoculated with pI, showed a distinct exacerbation of the lesion. Blastogenesis assays were performed with lymph node cells from the group of mice infected with L. amazonensis, but not inoculated with the peptides, and we detected lymphoproliferative responses in BALB/c and CBA mice with a 5.0x and 2.5x stimulation index, respectively. Cell phenotypes were evaluated and in both mouse strains CD8(+)cells proliferated more extensively than CD4(+)cells. INF-gamma and nitric oxide were detected only in supernatants obtained from CBA mouse lymph node cell cultures, whereas IL-4 was detected in supernatant cultures from both strains of mice. Our results indicate a preferential stimulation of CD8(+)T-cell subsets by the pI cysteine proteinase peptide and the induction of both Th1 and Th2 phenotypes during L. amazonensis infections in both BALB/c and CBA mice. We suggest that the pI peptide from the COOH-terminal region of the cysteine proteinase induces immune responses different from those elicited by the whole molecule.

The use of metal chelate affinity chromatography on the isolation of Leishmania chagasi promastigote hydrophobic proteinases

In this work, we have assessed the possibility of isolating metalloproteinase fractions from infective Leishmania chagasi promastigotes. Our strategy was the association of the Triton X-114 method with iminodiacetic chromatography enriched with Zn2+. Thus, by using acid conditions, it was possible to isolate two fractions containing two polypeptides, 59 and 63 kDa. The enzymatic activity assay indicated that the two fractions and the two polypeptides had proteinase activities. In addition, it was proposed that those proteinase activities were affected by the presence of 1,10-phenanthroline, a metalloproteinase inhibitor. With this gentle chromatography strategy proposed it is possible to obtain metalloproteinases from L. chagasi in folding that preserve the enzyme activity. This is important for further studies on pathological complications observed in visceral leishmaniasis.

Effect of Trypanosoma cruzi released antigens binding to non-infected cells on anti-parasite antibody recognition and expression of extracellular matrix components

It has been proposed that antigens released by Trypanosoma cruzi sensitize vertebrate cells leading to their destruction by the immune response raised against the parasite. Here, we characterized antigens released by trypomastigotes of T. cruzi that bind to non-infected cells and investigated biological consequences of this adsorption. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis of antigens released by [(35)S]-methionine-labeled parasites revealed the presence of polypeptides mainly ranging from 85 to 170 kDa that were specifically recognized by sera from chronically T. cruzi infected rabbits. Polypeptides of 85-110 and 160-170 kDa bound to non-infected epithelial, fibroblast and muscle mammalian cell lines, which thus became targets for anti-T. cruzi antibody binding. Cysteine-proteinase, but not trans-sialidase, was detected among the cell-bound antigens, and purified cysteine-proteinase was adsorbed to non-infected cells. Immunoelectron microscopic studies showed that parasite antigens were mainly released as membrane vesicles that adhered to membrane microvilli and were internalized by mammalian cells. We provide evidence that adsorption of parasite antigens induced an increase in expression of extracellular matrix (ECM) components (fibronectin, laminin and type I collagen) by sensitized cells. Thus, our data reinforce the idea that in vivo T. cruzi released antigens might be involved in the establishment of inflammation, sensitizing non-infected host cells and triggering an immune response against parasite antigens. Further, our data showed that antigen sensitization modulates biological cell functions as ECM expression that could mediate cell-cell or parasite-host cell interactions, contributing to the establishment of inflammation.

Low prevalence of methicillin-resistant strains among Staphylococcus aureus colonizing young and healthy members of the community in Portugal

Recent reports suggest that methicillin-resistant Staphylococcus aureus (MRSA) may be emerging as a community pathogen. In Portuguese hospitals, the incidence of MRSA among disease causing isolates is extremely high (48-50%). To determine the prevalence of MRSA in the Portuguese community, nasal samples were obtained from 823 draftees, 484 nonmedical university students, and 107 high-school students. In addition, throat samples were obtained from the 823 draftees and S. aureus isolates were also recovered from 283 (13%) nasopharyngeal samples obtained from 2,111 children attending day-care centers. The rate of nasal colonization of S. aureus was 34%, 25%, and 46% for draftees, nonmedical university students, and high-school students, respectively. The rate of pharyngeal colonization of the draftees was 33%. Of the 1,001 S. aureus isolates obtained, seven were MRSA and eight were borderline oxacillin-resistant S. aureus (BORSA). By molecular typing techniques, five of the seven MRSA were identified as belonging to one of three highly epidemic clones, the Brazilian, Iberian, and Pediatric clones of MRSA, which were identified as endemic in Portuguese hospitals. The eight BORSA were all members of clones previously identified in international samples. In spite of the extremely high prevalence of MRSA in Portuguese hospitals, the carriage rate of MRSA in healthy and young individuals remains low.

The use of primary stenting or balloon percutaneous transluminal coronary angioplasty for the treatment of acutely occluded saphenous vein grafts. Results from the Brazilian National Registry--CENIC. Central Nacional de Intervenções Cardiovasculares

OBJECTIVE

We conducted a comparative analysis of the in-hospital outcomes of patients who underwent primary percutaneous transluminal angioplasty (PTCA) or stent implantation because of an acute myocardial infarction (AMI) related to an acute vein graft occlusion.

METHODS

Since 1991 the Brazilian Society of Hemodynamic and Interventional Cardiology has maintained a large database (CENIC). From these, we selected all consecutive patients, who underwent primary PTCA or stenting in the first 24 hours of AMI, with the target vessel being an occluded vein graft. Immediate results and major coronary events occurring up until hospital discharge were analyzed.

RESULTS

During this period, 5,932 patients underwent primary PTCA or stenting; 158 (3%) of the procedures were performed because of an acute vein graft occlusion. Stenting was performed in 74 (47%) patients. Patients treated with stents had a higher success rate and lower mean residual stenosis compared with those who underwent primary balloon PTCA. The incidence of reinfarction and death were similar for stenting and balloon PTCA.

CONCLUSION

Primary percutaneous treatment of AMI related to acute vein graft occlusion is still an uncommon practice. Primary stenting improved luminal diameter and offered higher rates of success; however, this strategy did not reduce the in-hospital reinfarction and death rate, compared with that occurring with PTCA treatment.

A strategy for the identification of T-cell epitopes on Leishmania cysteine proteinases

In this study computational analysis was used to compile sequence alignments, construct a dendrogram and calculate physical data in order to predict potential T-cell epitopes of the Leishmania cysteine proteinase. Using multiple alignment of human and Leishmania proteinase sequences deposited on data bank sequences, it was possible to predict that the extreme C-terminus of cysteine proteinase (Cyspep, 355-444) contained three peptides (pI 361-370, pII 415-422 and pIII 431-444) with charge score, hydrophobicity and isoelectric points compatible for human leucocyte-associated antigen (HLA) class II binding. The prediction was confirmed in vitro through the ability of synthetic peptides corresponding to the predicted regions to stimulate peripheral blood mononuclear cells of patients with leishmaniasis.

Facilitation of latent inhibition by the atypical antipsychotic risperidone

The action of the atypical antipsychotic risperidone on latent inhibition (LI), an animal model of schizophrenia, was investigated. The parameters of the procedure were set at values insufficient to generate LI in control rats. On the first day, rats administered 0.5, 1.0, or 2.0 mg/kg ip risperidone or vehicle were preexposed (PE) to 10 tone presentations. On the second day, they were again injected with drug or vehicle and then submitted to two conditioned stimulus (CS; tone)-unconditioned stimulus (US; shock) pairings. On the third day, suppression of their drinking response under the CS was measured. Nonpreexposed (NPE) animals were submitted to the same procedure except for the tone preexposure. On the suppression test, LI was not observed in control rats as well as in animals given 0.5 mg/kg risperidone. Animals given 1.0 and 2.0 mg risperidone, however, displayed an LI effect. The facilitation of LI by risperidone gives additional support to the LI paradigm as an animal model of schizophrenia.

Comparison of DNA sequencing of the protein A gene polymorphic region with other molecular typing techniques for typing two epidemiologically diverse collections of methicillin-resistant Staphylococcus aureus

The aim of this study was to compare the recently developed typing approach for methicillin-resistant Staphylococcus aureus (MRSA) based on the DNA sequencing of the protein A gene polymorphic region (spaA typing) with a combination of three well-established molecular typing techniques: ClaI-mecA vicinity polymorphisms, ClaI-Tn554 insertion patterns, and SmaI pulsed-field gel electrophoresis (PFGE) profiles. In order to evaluate the applicability of this typing technique in different types of studies, two groups of MRSA clinical isolates were analyzed: a collection of 185 MRSA isolates circulating in Hungary recovered from 17 hospitals in seven cities during a 3-year period (1994 through 1996), and a selection of 53 MRSA strains isolated in a single hospital in Hungary between 1997 and 1998. The 238 MRSA clinical strains from Hungary were first classified in clonal types (defined as ClaI-mecA::ClaI-Tn554::SmaI-PFGE patterns), and 65 of the 238 strains, representing major MRSA clones and some sporadic clones, were further analyzed by spaA typing. Our results showed that the lineages most recently introduced in the hospital setting showed little variability in spaA types, whereas the MRSA clones circulating for a longer period of time and spread among several hospitals showed a higher degree of variability. The implementation of the spaA typing method was straightforward, and the results obtained were reproducible, unambiguous, and easily interpreted. This method seems to be adequate for outbreak investigations but should be complemented with other techniques in long-term surveillance or in studies comparing distant clonal lineages.

Genetic diversity and clonal patterns among antibiotic-susceptible and -resistant Streptococcus pneumoniae colonizing children: day care centers as autonomous epidemiological units

Characterization by antibiotype of the 1,096 Streptococcus pneumoniae recovered from 2,111 nasopharyngeal samples of children attending 16 day care centers (DCCs) in Lisbon, Portugal, and molecular typing of 413 drug-resistant pneumococci (DRPn) and 89 fully drug-susceptible pneumococci (DSPn) has allowed several conclusions. (i) There was an increase in the frequency of DRPn colonizing children in DCCs from 40% in 1996 to 45% in 1997 to 50% in 1998. (ii) Drug resistance spread by cross-transmission of DRPn clones. A few (8 out of 57) DRPn clones were repeatedly isolated from a large number of children in several DCCs and during each period of surveillance, suggesting the epidemic nature of these clones, which included lineages representing internationally spread S. pneumoniae clones. (iii) Dissemination of resistance determinants among pneumococci colonizing the nasopharynx occurred. Association of identical pulsed-field gel electrophoresis patterns with diverse antibiotypes among pneumococci colonizing children suggests that the high prevalence of DRPn involves not only cross-transmission of resistant strains but also dispersal of resistance genes through recombinational mechanisms. (iv) DCCs are autonomous epidemiological units. Among the 413 DRPn, 57 different lineages were detected; these lineages were dispersed among the 16 DCCs to produce unique microbiological profiles for each of the DCCs. Higher genetic diversity and less sharing of clonal types were observed among the DSPn.

Detection of cysteine-proteinases in Leishmania amazonensis promastigotes using a cross-reactive antiserum

Rabbit serum against the cysteine-proteinases papain has been employed for the cellular localization of cysteine-proteinases of in Leishmania amazonensis promastigotes. By immunocytochemistry, immune complexes were found in the plasma membrane and in the flagella pocket of the parasite. The antiserum immunoprecipitated major iodinated proteins with molecular masses of 66, 45, 28 and 24 kDa and a wide partitioning of the Triton X-114 detergent phase. The presence of cysteine-proteinase at the cell surface membrane was also suggested by the detection of proteolytic activity in living cells (19.0 microg azocasein min(-1) 10(-7) promastigotes (1.0 S.D. )).

Primary coronary angioplasty and stent implantation in acute myocardial infarction. Comparative analysis of the in-hospital results in the CENIC/SBHCI registry. National Center of Cardiovascular Interventions members

OBJECTIVE

Comparative analysis of the in-hospital results after primary implantation of stents or coronary balloon angioplasty in patients with acute myocardial infarction (MI).

METHODS

CENIC (National Center of Cardiovascular Interventions) gathered data on 3, 924 patients undergoing coronary angioplasty (in the primary form, without the previous use of thrombolytic agents) in the first 24 hours after a MI, during the period of 1996-1998. From these 3,924 patients, 1,337 (34%) underwent stent implantation. We analyzed the success of the procedure and the occurrence of adverse cardiac events.

RESULTS

In patients undergoing stent implantation there were more males (77% vs 69%, p=0.001), previous by pass surgery (6. 3% vs. 4.5%, p=0.01), anterior MI and stent implantation in left descending artery (55% vs. 48% vs. p=0.009), and saphenous vein bypass grafts (3.3% vs. 1.9%). the procedure was more succesful in the group of stents (97% vs. 84%, p=0.001) and reinfarction rate (2. 5 vs. 4%, p=0.002). The need for emergency revascularization was similar (1% vs. 1.1%, NS). Total in-hospital mortality was lower in stent group (3.4% vs. 7. 2%, p=0.0001) and this effect was in patients Killip class III/V (19.5% vs. 32.5%, p= 0.002) because there was no difference in patients class I/II (1.7% vs. 2.8%, p=0. 9).

CONCLUSION

Primary stent implantation in acute myocardial infarction showed better early results than balloon angioplasty alome.

Evaluation of the stability and immunogenicity of autoclaved and nonautoclaved preparations of a vaccine against American tegumentary leishmaniasis

This study was designed to evaluate the immunogenicity of autoclaved and nonautoclaved preparations of a vaccine composed of whole antigens from killed promastigotes of Leishmania amazonensis. Leishmanin skin-test (LST)-negative volunteers were immunized with either autoclaved or nonautoclaved vaccine preparations (32 and 36 subjects, respectively) that had been maintained at 4 degrees C for one year before the onset of this trial. Immunological tests were performed two days before and 40 days after vaccination. The LST conversion rates induced by the autoclaved and nonautoclaved vaccines were significantly different: 59% and 83%, respectively. Leishmania antigen-stimulated proliferative responses of peripheral blood mononuclear cells (PBMC) were significantly higher after vaccination than before vaccination in both groups. The CD8+ subset was predominant over the CD4+ subset among the leishmania-reactive cells after vaccination in both groups. The production of IFN-gamma by the leishmania antigen-stimulated PBMC was significantly higher after vaccination than before vaccination in the group receiving the nonautoclaved vaccine but not in the autoclaved vaccine group. IL-2 was found both before and after vaccination with no differences between its levels in these time points in either group. IL-4 was not detected for either group during the study period.

Anxiogenic-like effect of acute and chronic fluoxetine on rats tested on the elevated plus-maze

The selective serotonin reuptake inhibitor fluoxetine (FLX) is widely prescribed for depression and anxiety-related disorders. On the other hand, enhanced serotonergic transmission is known to be classically related to anxiety. In this study, the effects of acute (5.0 mg/kg) and chronic (5.0 mg/kg, 22 days) FLX were investigated in both food-deprived and non-deprived rats tested in the elevated plus-maze. Significant main effects of the three factors (drug, food condition and administration regimen) were observed, but no interaction between them. The administration of either acute or chronic FLX resulted in an anxiogenic effect, as detected by a significant reduction in the percentage of time spent in the open arms and in the percentage of open arm entries. Food deprivation yielded an anxiolytic-like profile, probably related to changes in locomotor activity. The administration regimen resulted in an anxiolytic profile in chronically treated rats, as would be expected after 22 days of regular handling. The anxiogenic action of acute FLX is consistent with both its neurochemical and clinical profile. The discrepancy between the anxiogenic profile of chronic FLX and its therapeutic uses is discussed in terms of possible differences between the type of anxiety that is measured in the plus-maze and the types of human anxiety that are alleviated by fluoxetine.

Detrimental effect of nitric oxide on Trypanosoma cruzi and Leishmania major like cells

The production of nitric oxide (NO) by activated macrophages has been reported to be a non-specific immune-effect mechanism against several parasites. In this work we investigate whether the NO has a detrimental effect on the intracellular parasites of the genus Leishmania and as well as Trypanosoma cruzi. This was assessed by co-cultivating infective Leishmania promastigotes and T. cruzi trypomastigotes and non-infective T. cruzi epimastigotes forms of the parasites in the presence of the NO releasing molecule, S-nitroso-N-acetyl-DL-penicillamine (SNAP). We demonstrate that the NO has the ability to inhibits the growth of all parasites in a concentration dependent manner. In addition, by analysing purified protein and cell homogenates of L. major (promastigotes) and T. cruzi (epimastigotes and trypomastigotes) we demonstrated that the NO may regulate the glyceraldehyde-3-phosphate dehydrogenase (GAPDH) activity of both parasites.

Single-step purification of crotapotin and crotactine from Crotalus durissus terrificus venom using preparative isoelectric focusing

We describe the isolation of crotoxin, a presynaptic B-neurotoxin, as well as its subunits B (crotactine) and A (crotapotin) from lyophilized Crotalus durissus terrificus venom by a single-step preparative isoelectric focusing procedure. From 98 mg of dried venom protein 20.1 mg of crotactine and 13.1 mg of crotapotin were recovered in the first step of focalization and 4.2 mg in a second run. These values correspond to 35.7% of the total venom protein applied. Crotactine separated in the 9.3-7.0 pH range (tubes 1-6) and crotapotin in the 1.8-2.8 pH range (tubes 15-19) and both were homogeneous by SDS-PAGE and N-terminal amino acid analysis. Crotactine, a 12-kDA protein, presented hemolytic and phospholipase A2 activity. Thus, using isoelectric focusing we simultaneously purified both toxins in high yields. This method can be used as an alternative for the purification and characterization of proteins from other snake venoms under conditions in which biological activity is retained.

Purification and partial characterization of a thrombin-like/gyroxin enzyme from bushmaster (Lachesis muta rhombeata) venom

The acidic coagulating enzyme of the L. m. rhombeata venom was purified to homogeneity using one step on preparative isoelectric focusing followed by gel permeation on a high performance liquid chromatography system. The enzyme focused with pIs 3.1-5.0 and had a molecular mass of 47,000 mol. wt as determined by high performance liquid gel-filtration chromatography and about 45,000 mol. wt as judged by sodium dodecyl sulfate-polyacrylamide-gel electrophoresis. The enzyme is a glycoprotein containing sialic acid and 12.4% of neutral carbohydrates. The 30 N-terminal amino acid sequence of the L. m. rhombeata protein shows 100% identity with L. m. muta gyroxin and considerable sequence homology with gyroxin and thrombin-related proteins. The enzyme exhibits strong N-p-tosyl-L-arginine methyl esterase activity, hydrolyses tripeptide nitroanilide derivatives weakly or not at all, and cleaves specifically the fibropeptide A (alpha-chain).

[Comparative study of transthoracic Doppler echocardiogram, computed tomography and aortography in the diagnosis of thoracic aortic dissection]

PURPOSE

Comparative and prospective evaluation of three methods (transthoracic echo-Doppler (TTE), computerized tomography (CT) and aortography (AORT) utilized for aortic dissection diagnosis.

METHODS

The 39 patients with confirmed aortic dissection (surgery or autopsy) underwent, within a few hours of each other, all three methods scrutinized. There were 19 cases of type A and 20 of type B dissection.

RESULTS

In type A dissection the methods were equivalent (TTE = 73.7%, CT = 84.2%, AORT = 73.7% p = NS) but for type B, TTE was significantly inferior to the other two methods (TTE = 60%, TC 90%, AORT = 80%, p < 0.05 for TTE, for TC and AORT p = NS). In three occasions, even though all three methods were performed, the diagnosis was not obtained.

CONCLUSION

The methods which were evaluated make the diagnosis in the majority of cases. In type A all methods are similar, however, in type B, TC and AORT are superior to TTE. Even performing all three methods in each patient, in three instances the diagnosis was not made.

Heterogeneity of cysteine proteinases in Leishmania braziliensis and Leishmania major

Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) with acrylamide copolymerized with gelatin (substrate-SDS-PAGE) was used to compare promastigote proteinases from two Leishmania species (L. braziliensis and L. major-like). Substrate-SDS-PAGE resolved at least 6 distinct proteinase activities with relative molecular masses between 20 and 65 kDa. The profile of proteinase activity was the same for both species, although qualitative differences were observed. L. major-like expressed a low molecular weight (20 kDa) proteinase with maximum activity at pH 7.0, which was demonstrable from pH 5.0 to pH 8.0. The 20-kDa protease was recovered in the detergent phase of TX-114 and was inhibited by the sulfhydryl group-blocking reagent E-64 (2.5 mM) and the non-specific inhibitor iodoacetic acid (1 mM). Pepstatin (1 microM) and PMSF (2.5 mM) did not inhibit the 20-kDa enzyme. The present study suggests that both Leishmania species studied express hydrophobic cysteine proteases of different molecular weights, since about 2 x 10(7) parasites were analyzed in each lane and the proteolytic activity developed at 37 degrees C for 16 h.