ABSTRACT A model is made for the dynamics of the transmission of the new SARS-CoV-2 coronavirus, which caused the COVID-19 pandemic. This model is based on the Susceptible-Infectious-Recovered model with heterogeneity in the susceptible population and in the infectious population. The susceptible population is divided into two subpopulations: individuals who are health professionals and individuals who are not. The infectious population is also divided into two subpopulations: individuals who are hospitalized and individuals who are not. A qualitative analysis of the theoretical model is performed, as well as simulations with official data regarding COVID-19 in the city of Manaus, Amazonas, Brazil, which corroborate the profile of the solution curves defined by the model.

RESUMO Objetivos: Avaliar a sensibilidade ao contraste em pacientes virgens de tratamento com retinopatia diabética proliferativa de não alto risco, submetidos a panfotocoagulação retiniana com injeções intravítreas de ranibizumabe versus panfotocoagulação isolada. Métodos: Sessenta olhos de 30 pacientes foram randomizados em dois grupos: um submetido a panfotocoagulação com injeções de ranibizumabe (grupo estudo), e o outro submetimedo a panfotocoagulação isolada (grupo controle). Todos olhos foram tratados em 3 sessões de laser, seguindo recomendação do Early Treatment Diabetic Retinopathy Study (ETDRS). Avaliação da sensibilidade ao contraste foi realizada sob condições fotópicas (85 cd/m2) com tabela Visual Contrast Test Sensitivity 6500, permitindo avaliação de cinco frequências espaciais medidas com redes senoidais: 1.5, 3.0, 6.0, 12.0 e 18.0 ciclos por grau de ângulo visual (cpd). Foram realizadas medidas dos limiares de sensibilidade ao contraste intra e entre grupos na visita inicial, no 1º, 3º, e 6º mês de seguimento. Resultados: Cinquenta e oito olhos, 28 do grupo estudo e 30 do grupo controle, atingiram o término do estudo. Análise comparativa da SC entre os grupos mostrou diferença estatisticamente significante, nas baixas frequências espaciais, no 1º mês em 1.5 cpd (p=0,001) e 3.0 cpd (p=0,04), no 3º mês em 1.5 cpd (p=0,016) e no 6º mês em 3.0 cpd (p=0,026) a favor do grupo estudo. Conclusão: O tratamento com panfotocoagulação associada a injeção de ranibizumabe parece causar menos danos a sensibilidade ao contraste quando comparada com panfotocoagulação isolada em olhos com retinopatia diabética proliferativa de não alto risco. Dessa forma, os resultados apresentados podem justificar a associação do ranibizumabe à panfotocoagulação nestes pacientes.

ABSTRACT Purpose: To evaluate contrast sensitivity in non-high-risk, treatment-naïve proliferative diabetic retinopathy patients treated with panretinal photocoagulation and intravitreal injections of ranibizumab) versus panretinal photocoagulation alone. Methods: Sixty eyes of 30 patients with bilateral proliferative diabetic retinopathy were randomized into two groups: one received panretinal photocoagulation and ranibizumab injections (study group), while the other received panretinal photocoagulation alone (control group). All eyes were treated with panretinal photocoagulation in three sessions according to the Early Treatment Diabetic Retinopathy Study guidelines. Contrast sensitivity measurements were performed under photopic conditions (85 cd/m2) with the Visual Contrast Test Sensitivity 6500 chart, allowing for the evaluation of five spatial frequencies with sine wave grating charts: 1.5, 3.0, 6.0, 12.0, and 18.0 cycles per degree (cpd). Outcomes were measured in contrast sensitivity threshold scores among and within groups, from baseline to 1, 3, and 6 months. Results: Fifty-eight eyes (28 in the study group and 30 in the control group) reached the study endpoint. A comparative analysis of changes in contrast sensitivity between the groups showed significant differences mainly in low frequencies as follows: at month 1 in 1.5 cpd (p=0.001) and 3.0 cpd (p=0.04); at month 3 in 1.5 cpd (p=0.016), and at month 6 in 1.5 cpd (p=0.001) and 3.0 cpd (p=0.026) in favor of the study group. Conclusions: In eyes of patients with non-high-risk proliferative diabetic retinopathy, panretinal photocoagulation treatment with ranibizumab appears to cause less damage to contrast sensitivity compared with panretinal photocoagulation treatment alone. Thus, our evaluation of contrast sensitivity may support the use of ranabizumab as an adjuvant to panretinal photocoagulation for the treatment of proliferative diabetic retinopathy.

A novel, fast, low-cost and scalable methodology to prepare stable magnetoliposomes (MGLs), without the use of organic solvents, is described. The concept of the work is based on the dual use of soy lecithin associated to a new liposome preparation methodology. Soy lecithin was used to coat the nanoparticles of magnetite (Fe3 O4 @lecithin) and for encapsulation of Fe3 O4 @lecithin (Lip-Fe3 O4 @lecithin). Liposomes with size less than 160 nm, polydispersity index of 0.25 and zeta potential of -41 mV, were prepared with the use of autoclave and sonication. The liposomal formulations containing magnetite and stigmasterol (Lip-Fe3 O4 @lecithin, Lip-Stigma and Lip-Stigma-Fe3 O4 @lecithin) were shown to be promising for the application as antibacterial. The liposomal formulation and magnetite were characterized by the following techniques: conventional and high-resolution transmission electron microscopy (TEM/HRTEM), energy-filtered transmission electron microscopy (EFTEM), proton nuclear magnetic resonance (1H NMR), Fourier transform infrared spectroscopy (FTIR), X-ray powder diffraction (XRPD), dynamic light scattering (DLS) and zeta potential. The Lip-Fe3 O4 @lecithin had a minimum inhibitory concentration (MIC) of 8.4 µg mL-1 in the presence of 200 Oe magnetic field against S. aureus.

ABSTRACT The phytochemical study of the extract leaves from Maytenus distichophylla Mart. and Salacia crassifolia (Mart. ex Schult.) G. Don, Celastraceae, resulted in the isolation of 3-oxofriedelane, 3β-hydroxyfriedelane, 3β,24-dihydroxyfriedelane, 3-oxo-28,29-dihydroxyfriedelane, two mixtures of pentacyclic triterpenes (α-amyrin with β-amyrin and 3β-stearyloxy-urs-12-ene with 3β-stearyloxy-olean-12-ene), 3β-palmityloxy-urs-12-ene, the steroid β-sitosterol and its glycosylated derivative β-glucosyl-β-sitosterol, tritriacontanoic acid and the natural polymer gutta percha. The chemical structures of these constituents were established by IR, 1H and 13C NMR spectral data. Crude extracts, the mixtures of triterpenes and the isolated constituents were subjected to in vitro acetylcholinesterase inhibitory evaluation. Acetylcholinesterase inhibitory effect was observed for crude chloroform extract leaves from M. distichophylla (100%) and S. crassifolia (97.93 ± 5.63%) and for the triterpenes 3β,24-dihydroxyfriedelane (99.05 ± 1.12%), 3-oxo-28,29-dihydroxyfriedelane (90.59 ± 3.76%) and 3β-palmityloxy-urs-12-ene (97.93 ± 1.47%). The percent inhibitions induced by these natural products were very similar to those produced by physostigmine (93.94 ± 2.10%) a standard acetylcholinesterase inhibitor. Therefore, these results open perspectives for the use of these species as source of compounds with similar physostigmine pharmacological effect.

Resumo Existem poucos estudos sobre características germinativas de espécies de cactos nativos, sendo a temperatura e a luz, os fatores que mais interferem nesse processo. Assim, objetivou-se caracterizar os frutos e avaliar a influência da temperatura e luminosidade na germinação de sementes de Rhipsalis floccosa, Rhipsalis pilocarpa and Rhipsalis teres. Testou-se temperaturas constantes de 15, 20, 25, 30 e 35 °C e alternadas de 20-30 °C e 25-35 °C com fotoperíodo de 10 horas, e com a determinação da temperatura mais adequada, testou-se a germinação na ausência de luz. A porcentagem de germinação, o índice de velocidade de germinação e o tempo médio de germinação foram avaliados. Para R. floccosa, a maior porcentagem de germinação foi obtida a 20 °C. Para R. pilocarpa e R. teres, as maiores porcentagens de germinação ocorreram a 15 °C e 20 °C. Verificou-se correlação entre as três espécies para a porcentagem de germinação, indicando comportamento semelhante entre essas. Na ausência de luz não ocorreu a germinação das sementes das espécies estudas. Em conclusão, a temperatura de 20 °C é a mais indicada para a germinação de sementes de R. floccosa. Para as espécies R. pilocarpa e R. teres, as temperaturas de 15 e 20 °C são as mais indicadas

Abstract The germination characteristics of the native cactus species are poorly known, being the temperature and the light the factors that the most interferes in that process. Thus, the objective of the present work was to characterize the fruits and evaluate the influence of the temperature and the light in the seed germination of Rhipsalis floccosa, Rhipsalis pilocarpa and Rhipsalis teres. The tested constant temperatures were 15, 20, 25, 30 and 35 °C and the alternate of 20-30 °C and 25-35 °C in a photoperiod of 10 hours, and with determination of the most appropriate temperature, the germination was tested in light absence. The germination percentage, the index of germination speed and medium time of germination were evaluated. For R. floccosa, the highest germination percentage was at 20 °C. For R. pilocarpa and R. teres, the highest germination percentages occurred in 15 °C and 20 °C. There was correlation to germination percentage between the three species, indicating that they had similar germination behavior. Total absence of germination was verified for the three species in condition of light absence. In conclusion, the temperature of 20 °C is the most suitable for the seed germination of R. floccosa. For the species R. pilocarpa and R. teres, the temperatures of 15 and 20 °C are the most suitable.

The phytochemical study of hexane extract from leaves of Salacia crassifolia resulted in the isolation of 3β-palmitoxy-urs-12-ene, 3-oxofriedelane, 3β-hydroxyfriedelane, 3-oxo-28-hydroxyfriedelane, 3-oxo-29-hydroxyfriedelane, 28,29-dihydroxyfriedelan-3-one, 3,4-seco-friedelan-3-oic acid, 3β-hydroxy-olean-9(11):12-diene and the mixture of α-amirin and β-amirin. β-sitosterol, the polymer gutta-percha, squalene and eicosanoic acid were also isolated. The chemical structures of these constituents were established by IR, 1H and 13C NMR spectral data. Crude extracts and the triterpenes were tested against Entamoeba histolytica, Giardia lamblia and Trichomonas vaginalis and no activity was observed under the in vitro assay conditions. The hexane, chloroform, ethyl acetate and ethanol crude extracts, and the constituent 3,4-seco-friedelan-3-oic acid and 28,29-dihydroxyfriedelan-3-one showed in vitro antimicrobial activity against Salmonella typhimurium, Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus cereus, Listeria monocytogenes, Streptococcus sanguinis and Candida albicans.

Três complexos inéditos do tipo [Cu(HL)Cl2] foram obtidos com N(4)-orto (H2Bz4oT, HL1), N(4)-meta (H2Bz4mT, HL2) e N(4)-para-toluil-2-benzoilpiridina tiossemicarbazona (H2Bz4pT, HL3), nos quais a tiossemicarbazona coordena-se ao metal por meio do sistema quelante Npy-N-S. H2Bz4pT (HL3) cristaliza-se no grupo espacial P1, a = 9,509(3) Å, b = 9,807(4) Å, c = 11,564(4) Å; alfa = 100,76(2)°, beta = 105,99(2)°, gama = 114,59(2)°. Tanto as tiossemicarbazonas quanto seus complexos de cobre(II) apresentaram atividade antifúngica pronunciada contra Candida albicans, com valores baixos de concentração inibitória mínima (CIM), entre 8 e 0,3 µg mL-1 (23 a 0,7 µmol L-1) para as tiossemicarbazonas e entre 1 e 0,1 µg mL-1 (2 a 0,3 µmol L-1) para os complexos. Nossos resultados sugerem que a coordenação ao cobre constitui estratégia interessante de redução da dose necessária à atividade.

Three new copper complexes of general formula [Cu(HL)Cl2] have been obtained with N(4)-ortho (H2Bz4oT, HL1), N(4)-meta (H2Bz4mT, HL2) and N(4)-para-tolyl-2-benzoylpyridine thiosemicarbazone (H2Bz4pT, HL3), in which the thiosemicarbazone attaches to the metal through the Npy-N-S chelating system. H2Bz4pT (HL3) crystallizes in the P1 space group, with a = 9.509(3) Å, b = 9.807(4) Å, c = 11.564(4) Å; alpha = 100.76(2)°, beta = 105.99(2)°, gamma = 114.59(2)°. The thiosemicarbazones and their copper(II) complexes exhibit high antifungal activities against Candida albicans with low values of minimum inhibitory concentration (MIC), in the 8-0.3 µg mL-1 (23 - 0.7 µmol L-1) range for the free bases and in the 1-0.1 µg mL-1 (2 - 0.3 µmol L-1) range for the complexes. Our results suggest that coordination to copper(II) could be an interesting strategy for dose reduction.

Protein expression in transgenic plants is considered one of the most promising approaches for producing pharmaceutical proteins. As has happened with other recombinant protein production schemes, the downstream processing (dsp) of these proteins produced in plants is key to the technical and economic success of large-scale applications. Since dsp of proteins produced transgenically in plants has not been extensively studied, it is necessary to broaden the investigation in this field in order to more precisely evaluate the commercial feasibility of this route of expression. In this work, we studied the substitution of an IMAC chromatographic step, described in previous work (Azzoni et al., 2002), with ion-exchange chromatography on SP Sepharose Fast Flow resin as the second step in the purification of recombinant aprotinin from transgenic maize seed. The main goal of this second purification step is to separate the recombinant aprotinin from the native corn trypsin inhibitor. Analysis of the adsorption isotherms determined at 25°C under different conditions allowed selection of 0.020 M Tris pH 8.5 as the adsorption buffer. The cation-exchange chromatographic process produced a high-purity aprotinin that was more than ten times more concentrated than that generated using an IMAC step.

TTV é um vírus DNA recentemente descoberto no Japão a partir de um paciente portador de hepatite pós-transfusional de origem desconhecida. Neste estudo, avaliamos a presença deste vírus em pacientes com hepatopatias crônicas dos estados de São Paulo e do Pará, representando duas regiões geograficamente diferentes. O DNA do TTV foi encontrado em 21/105 (20%) e 9/20 (45%) dos casos de São Paulo e do Pará, respectivamente. O seqüenciamento do DNA amplificado confirmou a presença dos genótipos 1a e 2a , bem como de outros genótipos ainda não descritos até o momento. Em conclusão, TTV está presente em casos de hepatopatias crônicas do Sudeste e do Norte do Brasil. Por outro lado, maiores estudos ainda são necessários antes de se estabelecer relação causal entre o TTV e a hepatite em seres humanos.

TTV is a recently discovered DNA virus, isolated from a patient with post-transfusion hepatitis of unknown etiology by Japanese researchers. In the present study, we evaluated the presence of TTV among chronic liver diseases patients in São Paulo and Pará states, representing two geographically distinct Brazilian regions. TTV DNA was found in 21/105 (20%) and 9/20 (45%) cases from São Paulo and Pará States, respectively. DNA sequence data confirmed the presence of TTV genotypes 1a and 2a, as well as other genotypes not yet described. In conclusion, TTV is present in chronic liver diseases cases from Southeast and North Brazil. However, further studies involving healthy populations are necessary before establishing any causal relationship among TTV and human hepatitis.