Anti-herpes simplex virus activity of sulfated galactans from the red seaweeds Gymnogongrus griffithsiae and Cryptonemia crenulata

This study presents the chemical composition and antiviral activity against herpes simplex virus type 1 (HSV-1) and 2 (HSV-2) of sulfated galactan crude extracts and main fractions obtained from two red seaweeds collected in Brazil, Gymnogongrus griffithsiae and Cryptonemia crenulata. Most of the eighteen tested products, including homogeneous kappa/iota/nu carrageenan and DL-galactan hybrid, exhibited antiherpetic activity with inhibitory concentration 50% (IC50) values in the range 0.5-5.6 microg/ml, as determined in a virus plaque reduction assay in Vero cells. The galactans lacked cytotoxic effects and showed a broad spectrum of antiviral activity against HSV-1 and HSV-2. No direct virus inactivation was observed after virion treatment with the galactans. The mode of action of these compounds could be mainly ascribed to an inhibitory effect on virus adsorption. Most importantly, a significant protection against a murine vaginal infection with HSV-2 was afforded by topical treatment with the sulfated galactans.     

“One feels anger to know there is no one to help us!”. Perceptions of mothers of children with Zika virus-associated microcephaly in Caribbean Colombia: A qualitative study

BackgroundThe epidemic of Zika virus (ZIKV) was associated with a sudden and unprecedented increase in infants born with microcephaly. Colombia was the second most affected country by the epidemic in the Americas. Primary caregivers of children with ZIKV-associated microcephaly, their mothers mainly, were at higher risk of suffering anxiety and depression. Often, these women were stigmatized and abandoned by their partners, relatives, and communities.Methodology/Principal findingsThis study aimed to understand the perceptions about ZIKV infection among mothers of children born with microcephaly during the ZIKV epidemic in Caribbean Colombia, and the barriers and facilitators affecting child health follow-up. An exploratory qualitative study, based on Phenomenology and Grounded Theory, was conducted in Caribbean Colombia. Data were collected through In-Depth Interviews (IDI) from women who delivered a baby with microcephaly during the ZIKV epidemic at Clínica Salud Social, Sincelejo, Sucre District (N = 11). The themes that emerged during the interviews included experiences from their lives before pregnancy; knowledge about ZIKV; experiences and perceptions when diagnosed; considering a possible termination of pregnancy, and children’s clinical follow-up. In some cases, women reported having been told they were having a baby with microcephaly but decided not to terminate the pregnancy; while in other cases, women found out about their newborn’s microcephaly condition only at birth. The main barriers encountered by participants during children’s follow-up included the lack of psychosocial and economic support, the stigmatization and abandonment by some partners and relatives, and the frustration of seeing the impaired development of their children.ConclusionsThis study contributed to identifying the social, medical, psychological, and economic needs of families with children affected by the ZIKV epidemic. Commitment and action by local and national governments, and international bodies, is required to ensure sustained and quality health services by affected children and their families.     

Carbohydrate metabolism in thyrotoxicosis: studies on insulin secretion before and after remission from the hyperthyroid state.

The effects of thyrotoxicosis on insulin secretion were studied in 11 patients with Graves' disease and compared with the results obtained in 6 of the patients after they had attained clinical remission. Constant glucose infusion (CGI) and acute tolbutamide infusion (AIT) tests were chosen to investigate beta-cell function. For similar means of fasting plasma glucose, basal plasma insulin mean was significantly higher during thyrotoxicosis. During AIT, mean peak insulin was obtained earlier in the hyperthyroid state (2 min) than after remission (4 min), being its level higher in the hyperthyroid state. During CGI, early insulin responses to similar plasma glucose increments, were comparable for both hyper and euthyroid subjects. After 10 minutes of CGI, insulin concentrations in the hyperthyroid state did not increase as in the euthyroid state in spite of comparable increments of plasma glucose, being similar plateau insulin levels attained thereafter. These results suggest the presence of an insulin-resistant state in hyperthyroidism which may either disappear during a chronic glucose infusion and/or be accompanied by a deficient late glucose-induced insulin release.     

Outbreak of Rocky Mountain spotted fever in Córdoba, Colombia

Rocky Mountain spotted fever (RMSF) is a tick-borne disease caused by the obligate intracellular bacterium Rickettsia rickettsii. Although RMSF was first reported in Colombia in 1937, it remains a neglected disease. Herein, we describe the investigation of a large cluster of cases of spotted fever rickettsiosis in a new area of Colombia.     

Leucojum aestivum plants propagated in in vitro bioreactor culture and on solid media containing cytokinins

Cytokinins are growth regulators that stimulate cell division and control morphogenesis in plants, however their role in regulating secondary metabolism is not well studied. The influence of various cytokinins (benzyladenine, zeatin, kinetin, meta‐topolin, thidiazuron) and culture systems (solid and temporary immersion RITA® system) on the quality Leucojum aestivum plant regenerated from somatic embryos was investigated. The largest number of regenerated plants (181.6 and 168.8) was obtained from the embryos cultivated on media enriched with meta‐topolin and benzyladenine. Thidiazuron and meta‐topolin led to the highest number of normally developed plants (94.8 and 90.6). The random amplified polymorphic DNA analysis of in vitro and in vivo plants showed four clusters of similarity. The highest biomass (growth index: 2.49) was obtained with the temporary immersion RITA® system. Alkaloid extracts were analyzed by LC‐MS, leading to the quantification of galanthamine and lycorine both in plant materials and in liquid media. The highest contents of galanthamine (0.05% dry weight) were observed in plants cultivated in the presence of thidiazuron in bioreactor system. Galanthamine was accumulated (highest content 0.05% dry weight) in plants cultivated in the presence of thidiazuron in bioreactor system whereas lycorine was synthetized mainly in plants cultivated on solid media.     

Employing in vitro directed molecular evolution for the selection of α-amylase variant inhibitors with activity toward cotton boll weevil enzyme

Numerous species of insect pests attack cotton plants, out of which the cotton boll weevil (Anthonomus grandis) is the main insect in Brazil and must be controlled to avert large economic losses. Like other insect pests, A. grandis secretes a high level of α-amylases in the midgut lumen, which are required for digestion of carbohydrates. Thus, α-amylase inhibitors (α-AIs) represent a powerful tool to apply in the control of insect pests. Here, we applied DNA shuffling and phage display techniques and obtained a combinatorial library containing 10⁸α-AI variant forms. From this library, variants were selected exhibiting in vitro affinity for cotton boll weevil α-amylases. Twenty-six variant sequences were cloned into plant expression vectors and expressed in Arabidopsis thaliana. Transformed plant extracts were assayed in vitro to select specific and potent α-amylase inhibitors against boll weevil amylases. While the wild type inhibitors, used to create the shuffled library, did not inhibit the A. grandis α-amylases, three α-AI mutants, named α-AIC3, α-AIA11 and α-AIG4 revealed high inhibitory activities against A. grandis α-amylases in an in vitro assay. In summary, data reported here shown the potential biotechnology of new α-AI variant genes for cotton boll weevil control.     

<Emphasis Type="Italic">In vitro</Emphasis> morphogenesis and micropropagation of <Emphasis Type="Italic">Aechmea ramosa</Emphasis> var. <Emphasis Type="Italic">ramosa</Emphasis> Mart. ex Schult. f. (Bromeliaceae) from leaf explants

Aechmea ramosa Mart. ex Schult. f. is an endemic bromeliad of the Brazilian Atlantic Forest. The current habitat degradation of this hotspot biome threatens this species, which besides having an important ecological role, is also of invaluable ornamental interest. Plant tissue culture has been used in mass propagation and conservation of various bromeliads. We have established a micropropagation protocol for A. ramosa var. ramosa using leaf explants grown in MS medium supplemented with 2 μM of 1-naphthaleneacetic acid (NAA) and 2 μM of 6-benzylaminopurine (BAP) that showed higher values of shoot induction. NAA and BAP are associated with the production of proteins involved in stress response modulation, metabolic activity, and cell division, the latter being involved in inducing the differentiation of competent cells. After 120 d of culture, each explant presented 28.9 shoots with an average size of 27.8 mm, with no variation in either Stomatal Index or density of the regenerated shoots. Plantlets measuring above 15-mm height were successfully acclimatized, presenting 100% survival rate. Thus, this protocol can be used for mass propagation of A. ramosa, and to supply demand for the market of ornamental plants. Furthermore, it represents an important tool for the conservation of this species and maintenance of an in vitro germplasm.     

β-(1→6)-<Emphasis Type="SmallCaps">d</Emphasis>-glucan secreted during the optimised production of exopolysaccharides by <Emphasis Type="Italic">Paecilomyces variotii</Emphasis> has immunostimulatory activity

Paecilomyces variotii is a filamentous fungus that occurs worldwide in soil and decaying vegetation. Optimization of the fermentation process for exopolysaccharide (EPS) production from the fungus P. variotii, structure determination and immuno-stimulating activity of EPS were performed. Response surface methodology (RSM) coupled with central composite design (CCD) was used to optimize the physical and chemical factors required to produce EPS in submerged fermentation. Preliminary investigations to choose the three factors for the present work were made using a factorial experimental design. Glucose, ammonium nitrate (NH₄NO₃) and pH were used as variables for which, with constant temperature of 28 °C and agitation of 90 rpm, the optimal process parameters were determined as glucose values of 0.96%, NH₄NO₃ 0.26% and pH 8.0. The three parameters presented significant effects. In this condition of culture, the main composition of the isolated EPS was a linear β-(1 → 6)-linked-D-glucan, as determined by Nuclear Magnetic Resonance (NMR) and methylation analysis. This polysaccharide is a very unusual as an EPS from fungi, especially a filamentous fungus such as P. variotii. Murine peritoneal macrophages cultivated with β-glucan for 6 and 48 h showed an increase in TNF-α, IL-6 and nitric oxide release with increased polysaccharide concentrations. Therefore, we conclude that the β-(1 → 6)-linked-D-glucan produced in optimised conditions of P. variotii cultivation has an immune-stimulatory activity on murine macrophages.