Leishmanicidal activity of fractions rich in aporphine alkaloids from amazonian unonopsis species

In vitro evaluation of alkaloidal fractions of twigs, barks and leaves from two Unonopsis species, Unonopsis guatterioides R.E. Fr. and Unonopsis duckei R.E. Fr., Annonaceae, against promastigote forms of Leishmania amazonensis revealed these species as sources of substances with promising leishmanicidal potential. All alkaloidal fractions from twigs, barks and leaves of U. guatterioides were classified as highly active, with IC50 1.07, 1.90, and 2.79 mg/mL, respectively. Only the alkaloidal fraction from the twigs of U. duckei was classified as inactive2261368137

Seroconversion in asymptomatic COVID-19 pediatric patients with rheumatic diseases of one tertiary referral hospital

Objectives: To evaluate seroconverted asymptomatic COVID-19 in pediatric Autoimmune Rheumatic Diseases (ARDs) patients and to identify the risk factors related to contagion. Methods: A cross-sectional study was conducted in March 2021, before vaccination of children and adolescents in Brazil, including 77 pediatric ARDs patients, followed at a tertiary hospital and 45 healthy controls, all of them without a previous diagnosis of COVID-19. Data was obtained by a questionnaire with demographic data, symptoms compatible with COVID-19 over the previous year, and contact with people with confirmed COVID-19. Patient's medical records were reviewed to access data regarding disease and current medications. A qualitative immunochromatographic SARS-CoV-2 test was performed on all participants. Results: Patients and controls were similar in terms of female gender (70.1% vs. 57.8%, p = 0.173), age (14 vs. 13 years, p = 0.269) and SARS-CoV-2 positive serology (22% vs. 15.5%, p = 0.481). 80.5% of rheumatic patients were in use of immunosuppressive drugs: 27.3% of them used corticosteroids (33.3% in high doses), and 7.8% on immunobiologicals. No statistical differences were found between positive (n = 17) and negative serology (n = 60) patients regarding demographic/socioeconomic data, contact with people with confirmed COVID-19, use and number of immunosuppressive drugs, use and dose of corticosteroids, use of hydroxychloroquine and immunobiological drugs (p > 0.05). Conclusions: Pediatric rheumatic disease patients were infected at the same rate as healthy ones. Neither the underlying pathology nor its immunosuppressive treatment seemed to interfere with contagion risk

Quinquangulin and Rubrofusarin: A Spectroscopy Study

In this work, excitation and emission spectra were evaluated in order to elucidate the properties of quinguangulin and rubrofusarin in water/ethanol mixture. The study demonstrates that the maximum excitation wavelength can be significantly modulated changing the proportion of organic solvent in the water/organic solvent system. Quinquangulin presented the higher wavelength of maximum excitation in an ethanol-water mixture containing 70% of water. Probably, the organization between ethanol and water molecules in this condition favors the formation of strong polar interactions with the π* orbitals of naphthopyrones. It is interesting to register that the additional methyl group in quinquangulin seems to develop a decisive function related to the ability to formation of hydrogen bonds, altering significantly the mechanism of solute-solvent interaction. This work, which involves theoretical and experimental analyses, demonstrates the relevance of the studies focused on solvent mixtures as well as emphasizes the potential of quinguangulin and rubrofusarin as photosensitizers. DOI: http://dx.doi.org/10.17807/orbital.v9i4.104

Protection against tuberculosis by a single intranasal administration of DNA-hsp65 vaccine complexed with cationic liposomes

<p>Abstract</p> <p>Background</p> <p>The greatest challenges in vaccine development include optimization of DNA vaccines for use in humans, creation of effective single-dose vaccines, development of delivery systems that do not involve live viruses, and the identification of effective new adjuvants. Herein, we describe a novel, simple technique for efficiently vaccinating mice against tuberculosis (TB). Our technique consists of a single-dose, genetic vaccine formulation of DNA-hsp65 complexed with cationic liposomes and administered intranasally.</p> <p>Results</p> <p>We developed a novel and non-toxic formulation of cationic liposomes, in which the DNA-hsp65 vaccine was entrapped (ENTR-hsp65) or complexed (COMP-hsp65), and used to immunize mice by intramuscular or intranasal routes. Although both liposome formulations induced a typical Th1 pattern of immune response, the intramuscular route of delivery did not reduce the number of bacilli. However, a single intranasal immunization with COMP-hsp65, carrying as few as 25 μg of plasmid DNA, leads to a remarkable reduction of the amount of bacilli in lungs. These effects were accompanied by increasing levels of IFN-γ and lung parenchyma preservation, results similar to those found in mice vaccinated intramuscularly four times with naked DNA-hsp65 (total of 400 μg).</p> <p>Conclusion</p> <p>Our objective was to overcome the significant obstacles currently facing DNA vaccine development. Our results in the mouse TB model showed that a single intranasal dose of COMP-hsp65 elicited a cellular immune response that was as strong as that induced by four intramuscular doses of naked-DNA. This formulation allowed a 16-fold reduction in the amount of DNA administered. Moreover, we demonstrated that this vaccine is safe, biocompatible, stable, and easily manufactured at a low cost. We believe that this strategy can be applied to human vaccines to TB in a single dose or in prime-boost protocols, leading to a tremendous impact on the control of this infectious disease.</p

Occupational exposure of workers to pesticides: Toxicogenetics and susceptibility gene polymorphisms

Farm workers are often exposed to pesticides, which are products belonging to a specific chemical group that affects the health of agricultural workers and is mostly recognized as genotoxic and carcinogenic. The exposure of workers from Piauí, Brazil, to these hazardous chemicals was assessed and cytogenetic alterations were evaluated using the buccal micronucleus assay, hematological and lipid parameters, butyrylcholinesterase (BChE) activity and genetic polymorphisms of enzymes involved in the metabolism of pesticides, such as PON1, as well as of the DNA repair system (OGG1, XRCC1 and XRCC4). Two groups of farm workers exposed to different types of pesticides were evaluated and compared to matched non-exposed control groups. A significant increase was observed in the frequencies of micronuclei, kariorrhexis, karyolysis and binucleated cells in the exposed groups (n = 100) compared to controls (n = 100). No differences were detected regarding the hematological parameters, lipid profile and BChE activity. No significant difference was observed either regarding DNA damage or nuclear fragmentation when specific metabolizing and DNA repair genotypes were investigated in the exposed groups