A mechanism for improved talc pleurodesis via foam delivery.

Talcum powder is recognized as the leading drug for pleurodesis, a treatment of choice for malignant pleural effusions. Recently, it was shown that hydrogel foam delivery systems significantly enhanced the number of adhesions between the chest wall and the lung in a New Zealand rabbit model due to the sol-gel transition. However, many questions still remain regarding the cause of improved efficacy, such as: (1) Would only hydrogel foams improve the efficacy of talc pleurodesis? (2) Is it possible to achieve the same efficacy of hydrogels using non-hydrogel foams? 3) What are the physicochemical properties that can be correlated to the efficacy of talc pleurodesis? In this study, we use non-hydrogel foam formulations to determine the efficacy of pleurodesis. Foam stability and rheology of the formulations were correlated to adhesion formation. The results clearly suggest a correlation of pleurodesis efficacy to the viscosity and modulus of the foam delivery system.

Ectoparasites infesting animals living in close contact with human beings: a real trouble for One Health perspective? / [Ectoparasitos infestando animais que vivem em contato próximo com seres humanos: um problema real para a perspectiva Saúde Única?]

The number of domestic animals living with human beings is rapidly increasing in parallel with an enhanced risk of transmission of their parasites and the pathogens they might carry. The aim of this study was to assess the occurrence of hematophagous arthropods infesting domestic animals from Northeastern Brazil and to remark the implications of their occurrence on the epidemiology and control of selected veterinary and human diseases. From January 2017 to April 2019, ectoparasites infesting domestic cats, dogs and horses were collected for their respective hosts and identified. Overall, ectoparasites were sampled from 86 domestic animals, living in different anthropic settings. A total of 401 specimens (344 ticks and 57 fleas) were collected from different hosts [i.e., 10 (2.49%), 96 (23.94%) and 295 (73.57%) from cats, dogs and horses, respectively]. Two flea (i.e., Ctenocephalides canis and Ctenocephalides felis) and 5 tick species (i.e., Amblyomma ovale, Amblyomma sculptum, Dermacentor nitens, Rhipicephalus microplus and Rhipicephalus sanguineus sensu lato) were identified. This study provides data on the ectoparasite fauna infesting domestic animals from Northeastern Brazil. The diagnosis and treatment of these parasites should not be underestimated, considering the role that hematophagous arthropods display as vectors of pathogens of medical and veterinary concern.(AU)

O número de animais domésticos infestados por ectoparasitos vivendo em estreito contato com seres humanos está aumentando, elevando o risco de infecção pelos patógenos transmitidos por vetores. Objetivou-se neste estudo avaliar a ocorrência de ectoparasitos infestando animais do nordeste do Brasil e discutir as implicações desse parasitismo na epidemiologia e no controle de doenças de importância médico-veterinária. De janeiro de 2017 a abril de 2019, artrópodes foram coletados de gatos, cães e cavalos, e identificados morfologicamente. Ectoparasitos foram removidos de 86 animais infestados provenientes de áreas urbanas e rurais. Foram identificados 401 espécimes (344 carrapatos e 57 pulgas) coletados de diferentes hospedeiros (10 (2,49%), 96 (23,94%) e 295 (73,57%) de gatos, cães e cavalos, respectivamente. Duas espécies de pulgas (Ctenocephalides canis e Ctenocephalides felis) e cinco espécies de carrapatos (Amblyomma ovale, Amblyomma sculptum, Dermacentornitens, Rhipicephalus microplus e Rhipicephalus sanguineus sensu lato) foram identificadas. Este estudo fornece informações sobre a ectofauna de animais domésticos do nordeste do Brasil. Portanto, o diagnóstico e o tratamento desses parasitos não devem ser subestimados, considerando que os artrópodes aqui relatados podem veicular patógenos de importância médico-veterinária.(AU)

Unusual specific heat of almost dry L-cysteine and L-cystine amino acids.

A detailed quantitative analysis of the specific heat in the 0.5- to 200-K temperature range for almost dry L-cysteine and its dimer, L-cystine, amino acids is presented. We report the occurrence of a sharp first-order transition at ∼76 K for L-cysteine associated with the thiol group ordering which was successfully modeled with the two-dimensional Ising model. We demonstrated that quantum rotors, two-level systems (TLS), Einstein oscillators, and acoustic phonons (the Debye model) are essential ingredients to correctly describe the overall experimental data. Our analysis pointed out the absence of the TLS contribution to the low temperature specific heat of L-cysteine. This result was similar to that found in other noncrystalline amorphous materials, e.g., amorphous silicon, low density amorphous water, and ultrastable glasses. L-cystine presented an unusual nonlinear acoustic dispersion relation ω(q)=vq0.95 and a Maxwell-Boltzmann-type distribution of tunneling barriers. The presence of Einstein oscillators with ΘE∼70 K was common in both systems and adequately modeled the boson peak contributions.

Boson peak as a probe of quantum effects in a glassy state of biomolecules: the case of L-cysteine.

Some physical properties of hydrated biomolecules, e.g., the occurrence of a boson peak, have been recognized to resemble those of glassy states. The present work shows that quantum fluctuations play a fundamental role in describing the glassy state of biomolecules, particularly at lower hydration levels. There is a linear relationship between the quantumness and the slope of the temperature dependence of the boson peak frequency, which is used to classify the extent of quantum contributions to the glassy state of glasses in general. Lastly, we demonstrate that the boson peak two-band spectral structure that is observed in some cases can be directly linked to the anisotropy of the elastic properties of the material. The amino acid L-cysteine is studied in detail. The findings are compared with previously reported data for other macromolecules.

Anharmonic transitions in nearly dry L-cysteine I.

Two special dynamical transitions of universal character have recently been observed in macromolecules (lysozyme, myoglobin, bacteriorhodopsin, DNA and RNA) at T* ~100-150 K and T(D) ~180-220 K. The underlying mechanisms governing these transitions have been the subject of debate. In the present work, a survey is reported on the temperature dependence of structural, vibrational and thermodynamical properties of a nearly anhydrous amino acid (orthorhombic polymorph of the amino acid l-cysteine at a hydration level of 3.5%). The temperature dependence of x-ray powder diffraction patterns, Raman spectra and specific heat revealed these two transitions at T* = 70 K and T(D) = 230 K for this sample. The data were analyzed considering amino acid-amino acid, amino acid-water, water-water phonon-phonon interactions and molecular rotor activation. Our results indicated that the two referred temperatures define the triggering of very simple and particular events that govern all the interactions of the biomolecular: activation of CH(2) rigid rotors (T < T* ), phonon-phonon interactions between specific amino acid and water dimer vibrational modes (T* < T < T(D)), and water rotational barriers surpassing (T > T(D)).

Distribution of human immunodeficiency virus type 1 subtypes in the state of Amazonas, Brazil, and subtype C identification

Few studies have reported the molecular epidemiological characterization of HIV-1 in the Northern region of Brazil. The present study reports the molecular and epidemiological characterization of 31 HIV-1 isolates from blood donors from the State of Amazonas who donated blood between April 2006 and March 2007. Serum/plasma samples from all donors were screened for HIV antibodies by ELISA and the results confirmed by Western blot analysis. Genomic DNA was extracted from the buffy coat using the Super Quik-Gene-DNA Isolation kit. Nested PCR was performed on the env, gag, and pol regions of HIV-1 using the Gene Amp PCR System 9700. Sequencing reactions were performed using the inner PCR primers and the DYEnamic™ ET Dye Terminator Kit, and phylogenetic analysis was performed using the gag, pol, and env gene sequences. We collected samples from 31 blood donors who tested positive for HIV-1 in confirmatory experiments. The male:female ratio of blood donors was 3.4:1, and the mean age was 32.4 years (range: 19 to 61 years). Phylogenetic analysis showed that subtype B is the most prevalent among Northern Brazilian HIV-1-seropositive blood donors. One HIV-1 subtype C and one circulating recombinant form (CRF_BF) of HIV-1 were identified in the State of Amazonas. This is the first study showing the occurrence of a possible "homogenous" subtype C in this region of Brazil. This finding could contribute to a better characterization of the HIV-1 strains that circulate in the country.