Caracterização de cubossomos não-iônicos em presença de proteínas modelo: uma abordagem estrutural e funcional / Characterization of non-ionic cubosomes in the presence of model pro­teins: a structural and functional approach

Uma área de pesquisa que vem ganhando muita atenção nos últimos anos é a nanome­dicina, com especial atenção para os sistemas com entrega controlada de fármacos, ou drug delivery. Dentre as diversas nanopartículas utilizadas para este fim, destacam-se os sistemas formados por lipídeos e polímeros, como por exemplo os lipossomos e os cubossomos. Neste trabalho, é estudada a influência estrutural da lisozima e da curcumina, proteínas modelo. A lisozima é uma enzima antimicrobiana produzida por animais e que faz parte do sistema imunológico. Ela é uma hidrolase glicosídica que catalisa a hidrólise dos componentes da parede celular de bactérias gram-positivas. Esta hidrólise, por sua vez, compromete a integridade das paredes celulares, causando a lise (e como consequência a morte) das bactérias. Curcumina é um composto cristalino de cor amarelada brilhante, encontrada no caule da Curcuma longa (ou açafrão), que tem sido utilizada como corante ou até mesmo como aditivo alimentar. Este composto tem sido uma grande aposta no tratamento de doenças crônicas como inflamação, artrite, síndrome metabólica, doença hepática, obesidade, doenças neurodegenerativas e principalmente canceres, sendo também utilizada em estudos como potencial agente antibacteriano. O principal objetivo deste trabalho é construir sistemas nanoestruturados com potencial de atuarem como sistemas antimicrobianos, com a liberação controlada de ambos dos fármacos. Estes sistemas são compostos por cubossomos de fitantriol (PHY) em ausência e presença da lisozima, da curcumina e de suas combinações, a fim de analisar ação antimicrobiana conjunta da lisozima e da curcumina. As técnicas biofísicas utilizadas para caracterizar essas partículas são SAXS (espalhamento de raios-X em baixos ângulos), DLS (espalhamento dinâmico de luz), Cryo-TEM (criomicroscopia eletrônica de transmissão) e NTA (análise de rastreamento de nanopartículas). Foi possível verificar que as formulações lipídicas são eficazes na formação de estruturas cúbicas com estabilidade desejável. As nanopartículas cúbicas demonstraram alta capacidade de encapsulação da lisozima e da curcumina. A cinética de liberação desses medicamentos mostrou-se promissora, sugerindo que a encapsulação dos fármacos é eficaz, bem como a liberação controlada e direcionada. Duas linhagens de bactérias foram estudadas, sendo que a E. coli, não sofreu nenhum dano citotóxico, enquanto a Bacillus subtilis sim. Tal resultado indica o potencial antimicrobiano do sistema para alguns tipos de bactérias

An area of research that has gained significant attention in recent years is nanomedicine, with a particular focus on drug delivery systems. Among the various nanoparticles used for this purpose, lipid and polymer-based systems, such as liposomes and cubosomes stand out. This study investigate the structural influence of encapsulating lysozyme and curcumin, model compounds. Lysozyme is an antimicrobial enzyme produced by animals and is part of the immune system. It is a glycosidic hydrolase that catalyzes the hydrolysis of components in the cell walls of gram-positive bacteria. This hydrolysis compromises the integrity of cell walls, leading to the lysis (and consequently the death) of bacteria. Curcumin is a bright yellow crystalline compound found in the stem of Curcuma longa (or turmeric), commonly used as a dye or even as a food additive. It has been a significant focus in the treatment of chronic diseases such as inflammation, arthritis, metabolic syndrome, liver disease, obesity, neurodegenerative diseases, and especially cancers. It is also studied as a potential antibacterial agent. The main objective of this study is to construct nanostructured systems with the potential to act as antimicrobial agents, with controlled release of both drugs. These systems consist of phytantriol (PHY) cubosomes in the absence and presence of lysozyme, curcumin, and their combinations to analyze the joint antimicrobial action of lysozyme and curcumin. Biophysical techniques used for characterization include Small-Angle X-ray Scattering (SAXS), Dynamic Light Scattering (DLS), Cryo-Transmission Electron Microscopy (Cryo-TEM), and Nanoparticle Tracking Analysis (NTA). It was observed that lipid formulations are effective in forming cubic structures with desirable stability. Cubic nanoparticles have demonstrated a high encapsulation capacity for lysozyme and curcumin. The release kinetics of these drugs have shown promise, suggesting that drug encapsulation is effective, as well as their controlled and targeted release. Two bacterial strains were studied, with E. coli showing no cytotoxic damage, while Bacillus subtilis did. This result indicates the antimicrobial potential of the system against types of bacteria

Tetradenia riparia leaves, flower buds, and stem essential oils to control of Aedes aegypti larvae

Abstract Tetradenia riparia (Hochst.) Codd (Lamiaceae) is a species native to the African continent and used as an insect repellent. The objective of the study was to evaluate the larvicidal potential of essential oils (EOs) from the leaves, flower buds, and stem of T. riparia, collected in winter against Aedes aegypti larvae. The EOs were extracted by hydrodistillation (3 h) and identified by GC/MS. The EOs were tested against larvae of A. aegypti at concentrations ranging from 12500 to 1.5 µg/mL for 24 h. The insecticide activity was evaluated by probit analysis, and the anticholinesterase activity was determined by bioautographic method. The results of the class projection indicated sesquiterpenes as the majority class, corresponding to 60.66% (leaves), 64.70% (flower buds) and 83.99% (stem), and the bioassays on A. aegypti larvae indicated LC50 of 1590, 675 and 665 µg/mL, respectively. The anticholinesterase activity indicated that the EO of the leaves inhibited the enzyme at a concentration of 780 µg/mL, and those from the flower buds and stem inhibited up to 1560 µg/mL. The results indicated weak activity of essential oils against A. aegypti larvae.

Essential Oil from the Stem Bark of Casuarina equisetifolia Exerts Anti-inflammatory and Anti-nociceptive Activities in Rats

Abstract Herein the chemical constituents and the anti-pain properties of the essential oil from the stem bark of Casuarina equisetifolia L. (Casuarinaceae) grown in Nigeria were evaluated. The essential oil was obtained by hydrodistillation method in an all glass Clevenger-type apparatus, and characterized by gas chromatography (GC-FID) and gas chromatography-mass spectrometry (GC-MS). The hot plate method was used to determine the anti-nociceptive property whereas the anti-inflammatory activity was evaluated by carrageenan-induced and formalin experimental models. The pale-yellow essential oil was obtained in yield of 0.21% (v/w), calculated on a dry weight basis. The main constituents of the essential oil were methyl salicylate (30.4%), a-zingiberene (15.5%), (E)-anethole (9.5%), b-bisabolene (8.6%), b- sesquiphellandrene (6.9%), and ar-curcumene (6.2%). In the anti-nociceptive study, the rate of inhibition increases as the doses of essential oil increases with optimum activity at the 30th and 60th min for all tested doses. The essential oil displayed anti-nociceptive activity independently of reaction time at the highest tested dose (200 mg/kg). The essential oil of C. equisetifolia moderately reduced pain responses in early and late phases of the formalin test. The oil inhibited the paw licking in the neurogenic phase (60-63%) compared to the late phase of the formalin test. The carrageenan- induced oedema model revealed the suppression of inflammatory mediators within the 1st - 3rd h. Thus, C. equisetifolia essential oil displayed both anti-nociceptive and anti-inflammatory activities independent of the dose tested. The anti-inflammatory and anti-nociceptive activities of C. equisetifolia essential oil are herein reported for the first time

Trasplante de progenitores hematopoyéticos alogénico haploidéntico en aplasia medular, reporte del primer caso en Cuba / Allogenic hematopoietic stem-cell transplantation in marrow aplasia: the first case report in cuba

Introducción: La aplasia medular adquirida grave es una enfermedad hematológica infrecuente caracterizada por una disminución o ausencia de precursores hematopoyéticos en la médula ósea, lo cual se expresa con distintos grados de citopenias. Varios factores, infecciosos o no, pueden incidir en su origen. Su manejo es complejo y puede incluir tratamiento inmunosupresor y trasplante de progenitores hematopoyéticos alogénico. Objetivo: Demostrar la utilidad de la realización del trasplante de progenitores hematopoyéticos alogénico haploidéntico en pacientes con aplasia medular grave. Caso clínico: Paciente masculino de 21 años de edad, con antecedentes de salud, que en octubre del 2018 debutó con íctero, pancitopenia, lesiones purpúrico hemorrágicas en piel y mucosas, en el curso de una hepatitis aguda seronegativa. La biopsia de médula ósea mostró aplasia medular severa. Se inició tratamiento inmunosupresor con globulina antitimocίtica, ciclosporina A y metilprednisolona. Al cabo de los 6 meses mantenía trombocitopenia severa con necesidades transfusionales y en octubre de 2019 se decide realizar trasplante de progenitores hematopoyéticos alogénico con donante haploidéntico y empleando como tratamiento acondicionante globulina antitimocίtica, fludarabina, ciclofosfamida y bajas dosis de irradiación corporal total. En evaluación clίnica de julio de 2020 (dίa + 280 del trasplante) el paciente estaba asintomático y con parámetros hematológicos normales. Conclusiones: Se demostró que el trasplante de progenitores hematopoyéticos alogénico haploidéntico es un proceder realizable y útil en pacientes con aplasia medular grave, lo cual corrobora el beneficio clínico que puede aportar su ejecución en pacientes con esta enfermedad(AU)

Introduction: Acquired severe marrow aplasia is a rare hematological disease characterized by decrease or absence of hematopoietic precursors in bone marrow, which is expressed with different degrees of cytopenias. Several factors, infectious or not, can influence its origin. Its management is complex and may include immunosuppressive treatment and allogeneic hematopoietic stem-cell transplantation. Objective: To demonstrate the usefulness of performing haploidentical allogeneic hematopoietic stem-cell transplantation in patients with severe medullary aplasia. Clinical case: A 21-year-old male patient, with medical history, who first presented, in October 2018, with icterus, pancytopenia, as well as purpuric hemorrhagic lesions on the skin and mucosa, in the course of acute seronegative hepatitis. The bone marrow biopsy showed severe marrow aplasia. Immunosuppressive treatment was started with antithymocytic globulin, cyclosporine A, and methylprednisolone. After six months, he maintained severe thrombocytopenia under transfusion requirements and, in October 2019, the decision was to perform allogeneic hematopoietic stem-cell transplantation with a haploidentical donor and using antithymocyte globulin, fludarabine, cyclophosphamide, and low doses of total body irradiation as conditioning treatment. In the clinical assessment carried out in July 2020 (day +280 after transplantation), the patient was asymptomatic and with normal hematological parameters. Conclusions: Transplantation of haploidentic allogeneic hematopoietic progenitors was shown to be a feasible and useful procedure in patients with severe marrow aplasia, which corroborates the clinical benefit that its execution can bring in patients with this disease(AU)

Phytochemical and morpho-anatomical study of the vegetative organs of Psychotria fractistipula L. B.Sm., R.M. Klein & Delprete (Rubiaceae)

Psychotria fractistipula L.B.Sm, R.M. Klein & Delprete (Rubiaceae) is found in the existing Atlantic Forest in the South of Brazil, in the Paraná and Santa Catarina States. The members of Rubiaceae are characterized chemically by the presence of alkaloids, some pharmacological properties of which include antifungal, antibacterial, analgesic, antioxidant, antimutagenic, and antiviral activities. In this study, we report the results of anatomical, morphological, and histochemical analyses of the leaves and stems of the Rubiaceae family member, P. fractistipula. The anatomical analysis involved of light microscopy and scanning electron microscopy. Morpho-anatomical and histochemical characterization were made using standard methodology. The isolated compounds were identified by Nuclear Magnetic Resonance spectroscopic analysis. The following structures are highlighted as the distinctive features of the species: presence of petiolate leaves and a petiole base, leaf blade with smooth cuticle on both surfaces, paracytic stomata, and, dorsiventral mesophyll and presence of trichomes on the leaves and stems. Phytosteroids, identified as β-sitosterol and campesterol, were observed in the hexane fraction of the stem. Future studies should focus on the isolation of other fractions of interest and their characterization through specific biological and cytotoxicity assays.

Agrobacterium rhizogenes-mediated transformation of Hypericum sinaicum L. for the development of hairy roots containing hypericin

Hypericum sinaicum L. is an endangered Egyptian medicinal plant of high importance due to the presence of naphthodianthrones (hypericins), which have photodynamic properties and pharmaceutical potential. We sought to assess H. sinaicum ability to develop hairy roots that could be cultured in contained conditions in vitro and used as a source for hypericin production. We used four A. rhizogenes strains differing in their plasmids and chromosomal backgrounds to inoculate excised H. sinaicum root, stem and leaf explants to induce hairy root development. Additionally, inoculum was applied to shoots held in Rockwool cubes supporting their stand after removal of the root system. All explant types were susceptible to A. rhizogenes although stem explants responded more frequently (over 90%) than other explant types. The A4 and A4T A. rhizogenes strains were highly, and equally effective in hairy root induction on 66-72% of explants while the LBA1334 strain was the most effective in transformation of shoots. Sonication applied to explants during inoculation enhanced the frequency of hairy root development, the most effective was 60 s treatment doubling the percentage of explants with hairy roots. However, shoot transformation was the most effective approach as shoots developed hairy roots within 10 days after inoculation. Molecular analyses confirmed that the established hairy root cultures in vitro were indeed obtained due to a horizontal gene transfer from bacteria. These cultures grew fast and the hypericin content in hairy roots was about two fold higher than in H. sinaicum plants as determined by HPLC.

Overview of chemical imaging methods to address biological questions.

Chemical imaging offers extensive possibilities for better understanding of biological systems by allowing the identification of chemical components at the tissue, cellular, and subcellular levels. In this review, we introduce modern methods for chemical imaging that can be applied to biological samples. This work is mainly addressed to the biological sciences community and includes the bases of different technologies, some examples of its application, as well as an introduction to approaches on combining multimodal data.

Estudo histopatológico da retina de coelhos após injeção intravítrea de lidocaína / Histopathologic study of the retina in rabbits after intravitreous injection of lidocaine

Objetivo: Estudar em olhos de coelhos as alterações retinianas após injeção intravítrea de lidocaína nas concentrações 0,5, 1,0 e 2,0 por cento por meio de análise histopatológica com microscopias de luz e eletrônica de transmissão. Métodos: Foram utilizados 40 olhos de 20 coelhos albinos da raça Nova Zelândia, submetidos à injeção intravítrea de lidocaína a 0,5 por cento (grupo II),1,0 por cento (grupo 111) e 2,0 por cento (grupo IV) nos olhos direitos e solução salina nos olhos esquerdos (grupo I-controle) após anestesia geral. Foi realizada oftalmoscopia binocular indireta, antes, durante, imediatamente e uma hora após a injeção intravítrea e nos dias primeiro , terceiro, sétimo e décimo quinto de evolução. Nos mesmos períodos um olho do grupo II, dois olhos do grupo III, um olho do grupo IV e todos olhos contralaterais (grupo I), foram enucleados e examinados sob microscopia de luz e eletrônica de transmissão. Resultados: A observação por oftalmoscopia binocular indireta antes e durante a injeção intravítrea não apresentou alteração em todos os olhos examinados. Após a injeção intravítrea observou-se a retina com aspecto esbranquiçado difuso, elevação da interface vítreo-retiniana, focal e próximo ao local de injeção, edema de retina e anel de condensação vítrea tanto no grupo controle quanto nos olhos com injeção de lidocaína. A análise histológica por microscopia de luz e eletrônica de transmissão não evidenciou alterações em nenhum dos olhos examinados. Conclusões: A injeção intravítrea de lidocaína nas concentrações de 0,5, 1,0 e 2,0 por cento demonstrou ser atóxica para a retina, considerando os estudos de microscopia de luz e eletrônica de transmissão.

Precipitate crystal structure determination in melt spun Mg-1.5wt%Ca-6wt%Zn alloy.

A melt-spun Mg-1.5%wtCa-6wt%Zn alloy was analyzed by means of transmission electron microscopy, energy dispersive X-ray spectroscopy, and scanning transmission electron microscopy. The as-solidified alloy exhibited both spherical matrix precipitates and elongated precipitates at the grain boundaries (grain-boundary films). After heat treatment, the alloy showed faceted precipitates (cuboidal shape), mostly on dislocations. It was found that the observed precipitates are the same compound, Ca2Mg6Zn3. As there was no crystallographic data for this compound in the literature, its crystal structure was investigated by comparison of experimental and simulated selected-area electron-diffraction patterns and high-resolution electron microscopy images. This study indicated that Ca2Mg6Zn3 is a trigonal compound with space group P 3 1c and lattice parameters a = 0.97 nm, c = 1.0 nm.