Latest Advances on Bacterial Cellulose‐Based Materials for Wound Healing,Delivery Systems,and Tissue Engineering

Bacterial cellulose (BC) is a nanocellulose form produced by some nonpathogenic bacteria. BC presents unique physical, chemical, and biological properties that make it a very versatile material and has found application in several fields, namely in food industry, cosmetics, and biomedicine. This review overviews the latest state‐of‐the‐art usage of BC on three important areas of the biomedical field, namely delivery systems, wound dressing and healing materials, and tissue engineering for regenerative medicine. BC will be reviewed as a promising biopolymer for the design and development of innovative materials for the mentioned applications. Overall, BC is shown to be an effective and versatile carrier for delivery systems, a safe and multicustomizable patch or graft for wound dressing and healing applications, and a material that can be further tuned to better adjust for each tissue engineering application, by using different methods.     

Habitat use of the ocelot (Leopardus pardalis) in Brazilian Amazon

Amazonia forest plays a major role in providing ecosystem services for human and sanctuaries for wildlife. However, ongoing deforestation and habitat fragmentation in the Brazilian Amazon has threatened both. The ocelot is an ecologically important mesopredator and a potential conservation ambassador species, yet there are no previous studies on its habitat preference and spatial patterns in this biome. From 2010 to 2017, twelve sites were surveyed, totaling 899 camera trap stations, the largest known dataset for this species. Using occupancy modeling incorporating spatial autocorrelation, we assessed habitat use for ocelot populations across the Brazilian Amazon. Our results revealed a positive sigmoidal correlation between remote‐sensing derived metrics of forest cover, disjunct core area density, elevation, distance to roads, distance to settlements and habitat use, and that habitat use by ocelots was negatively associated with slope and distance to river/lake. These findings shed light on the regional scale habitat use of ocelots and indicate important species–habitat relationships, thus providing valuable information for conservation management and land‐use planning.     

Role of Astrocytes in Manganese Neurotoxicity Revisited

Neurochemical Research - Manganese (Mn) overexposure is a public health concern due to its widespread industrial usage and the risk for environmental contamination. The clinical symptoms of Mn...     

24-Epibrassinolide Mechanisms Regulating Blossom-End Rot Development in Tomato Fruit

Blossom-end rot (BER) is a physiological disorder believed to be triggered by low Ca²⁺ content in the distal fruit tissue. However, many other factors can also determine fruit susceptibility to BER. It is possible that during fruit growth, Ca²⁺ imbalance can increase membrane leakiness, which may trigger the accumulation of reactive oxygen species, leading to cell death. Brassinosteroids are a class of plant hormones involved in stress defenses, specially increasing the activity of antioxidant enzymes and the accumulation of antioxidant compounds, such as ascorbic acid. The objective of this study was to understand the mechanisms by which 24-epibrassinolide (EBL) reduces fruit susceptibility to BER. Tomato plants ‘BRS Montese’ were cultivated in a greenhouse and were weekly sprayed with water (control) or EBL (0.01 µM) after full bloom. Plants and fruits were evaluated at 15 days after pollination (DAP). According to the results, EBL treatment inhibited BER development, increased fruit diameter, length, and fresh weight. EBL-treated fruit showed higher concentrations of soluble Ca²⁺ and lower concentrations of cell wall-bound Ca²⁺. EBL-treated fruit also had higher concentrations of ascorbic acid and lower concentrations of hydrogen peroxide, compared to water-treated fruit. EBL treatment increased the activity of the three main antioxidant enzymes known as ascorbate peroxidase, catalase, and superoxide dismutase. According to the results, EBL treatment maintained higher soluble Ca²⁺ and antioxidant capacity, reducing fruit susceptibility to BER.

     

Follow-up assessment of patients with Pure Neural Leprosy in a reference center in Rio de Janeiro—Brazil

IntroductionPure Neural Leprosy (PNL) is a rare clinical form of leprosy in which patients do not present with the classical skin lesions but have a high burden of the disability associated with the disease. Clinical characteristics and follow up of patients in PNL are still poorly described in the literature.ObjectiveThis paper aims to describe the clinical, electrophysiological and histopathological characteristics of PNL patients, as well as their evolution after multidrug therapy (MDT).MethodsFifty-two PNL patients were selected. Clinical, nerve conduction studies (NCS), histopathological and anti-PGL-1serology were evaluated. Patients were also assessed monthly during the MDT. At the end of the MDT, all of the patients had a new neurological examination and 44 were submitted to another NCS.ResultsParesthesia was the complaint most frequently reported by patients, and in the neurological examination the most common pattern observed was impairment in sensory and motor examination and a mononeuropathy multiplex. Painful nerve enlargement, a classical symptom of leprosy neuropathy, was observed in a minority of patients and in the motor NCS axonal injuries, alone or in combination with demyelinating features, were the most commonly observed. 88% of the patients did not present any leprosy reaction during MDT. There was no statistically significant difference between the neurological examinations, nor the NCS pattern, performed before and after the MDT.DiscussionThe classical hallmarks of leprosy neuropathy are not always present in PNL making the diagnosis even more challenging. Nerve biopsy is an important tool for PNL diagnosis as it may guide therapeutic decisions. This paper highlights unique characteristics of PNL in the spectrum of leprosy in an attempt to facilitate the diagnosis and management of these patients.     

Short Note on a Culture Experiment on Monthly Captured Glass Eels from the Rio Minho,Portugal

A recycling system combining biofiltration and hydroponics was used for rearing glass eels. Growth rates varied between 0.1 and 1.4% of body weight per feeding day. A large range of mortalities (9.4—93 %) after two months was mainly due to ectoparasitic infections.     

DNA barcode reveals candidate species of Scinax and Ololygon (Anura: Hylidae) in Atlantic Forest

Molecular species delimitation methods are efficient tools to identify species, including the discovery of new taxa and cryptic organisms, thus being useful to biodiversity studies. In the present work, 16S mitochondrial sequences and cytochrome oxidase I (COI) were used to evaluate the richness of species in the genus Scinax and Ololygon from a biodiversity hotspot in Atlantic Forest. A total of 109 specimens formally belonging to eight species of Scinax and three species of Ololygon were collected in 13 localities along the state of Bahia (northeastern Brazil) and one site in Espírito Santo (southeastern Brazil). Of the Scinax species collected in this study, three were morphologically differentiated from other described species and identified as putative new species (Scinax sp.1, Scinax sp.2 and Scinax sp.3). The species delimitations were inferred using three different methods: ABGD, PTP and mPTP which allowed recognizing 11 Scinax species and five Ololygon species. Scinax sp. 1, Scinax sp. 2 and Scinax sp. 3, have been confirmed as new putative species and Ololygon argyreornata possibly contains cryptic species. We suggest additional studies, including morphological and bioacoustic data to validate these new putative species.     

Stability of immobilized D-hydantoinase from Vigna angularis and repeated cycles of highly enantioenriched production of N-carbamoyl-D-phenylglycines

Summary. D-hydantoinase from Vigna angularis was immobilized by covalent linkage to aminopropyl glass beads. Thermal stability, resistance to storage at different pH values and temperatures of this biocatalyst were studied. This enzyme preparation was used as a catalyst to prepare enantioenriched N-carbamoyl-D-phenylglycine, N-carbamyl-D-p-fluorophenylglycine and N-carbamoyl-D-p-trifluoromethylphenylglycine, using a stirred batch reactor. Reactions were conducted during eight repeated reaction cycles, without loss of enzymatic activity or variation of the enantiomeric excess of the respective product (>98%).     

N-t-Boc-amino acid esters of isomannide Potential inhibitors of serine proteases

Summary. Hepatitis C, Dengue and West Nile virus are some of the most important flaviviruses, that share one important serine protease enzyme. Serine proteases are the most studied class of proteolytic enzyme and, in these cases, a primary target for drug discovery. In this paper, we describe the synthesis and preliminary molecular modeling studies of a novel class of N-t-Boc amino acid esters derived of isomannide as potential serine proteases inhibitors.