24-Epibrassinolide alleviates drought effects in young Carapa guianensis plants, improving the hydraulic safety margin, gas exchange and antioxidant defence.

Climate change is increasing the frequency of extreme events such as droughts, limiting plant growth and productivity. Exogenous application of plant growth regulators, such as 24-epibrassinolide (EBR), might be a solution as this molecule is organic, eco-friendly, and biodegradable. This is the first research to examine possible roles of EBR on the hydraulic safety margin, physiological behaviour, and metabolism in Carapa guianensis Aubl. (Meliaceae) exposed to drought. C. guianensis is a widely distributed tree in tropical forests of the Amazon. The objective was to determine whether EBR can improve tolerance to water deficit in young C. guianensis by measuring hydraulic traits, nutritional, biochemical and physiological responses, and biomass. The experiment had four randomized treatments: two water conditions (control and water deficit) and two concentrations of EBR (0 and 100 nM EBR). EBR increased the water potential and hydraulic safety margin, increased CO2 fixation, and improved stomatal performance. EBR also stimulated antioxidant defences (SOD, CAT, APX, and POX). Overall, tretreatment with EBR improved drought tolerance of young C. guianensis plants.

Ionic homeostasis and redox metabolism upregulated by 24-epibrassinolide are crucial for mitigating nickel excess in soybean plants, enhancing photosystem II efficiency and biomass.

Nickel (Ni) excess often generates oxidative stress in chloroplasts, causing redox imbalance, membrane damage and negative impacts on biomass. 24-Epibrassinolide (EBR) is a plant growth regulator of great interest to the scientific community because it is a natural molecule extracted from plants, is biodegradable and environmentally friendly. This study aimed to determine whether EBR can improve ionic homeostasis, antioxidant enzymes, PSII efficiency and biomass by evaluating nutritional, physiological, biochemical and morphological responses of soybean plants subjected to Ni excess. The experiment used four randomized treatments, with two Ni concentrations (0 and 200 µm Ni, described as -Ni2+ and +Ni2+ , respectively) and two concentrations of EBR (0 and 100 nm EBR, described as -EBR and +EBR, respectively). In general, Ni had deleterious effects on chlorophyll fluorescence and gas exchange. In contrast, EBR enhanced the effective quantum yield of PSII photochemistry (15%) and electron transport rate (19%) due to upregulation of SOD, CAT, APX and POX. Exogenous EBR application promoted significant increases in biomass, and these results were explained by improved nutrient content and ionic homeostasis, as demonstrated by increased Ca2+ /Ni2+ , Mg2+ /Ni+2 and Mn2+ /Ni2+ ratios.

Anatomical changes in stem and root of soybean plants submitted to salt stress.

The soybean is a legume that is widely cultivated in many countries due to the high levels of protein and oil contained in its seed, and is used for human and animal nutrition. However, salinity affects more than 800 million hectares worldwide, limiting global agricultural production. The aim of this research was to evaluate the structural behaviour of the roots and stems under progressive salt stress, detailing the possible anatomical modifications to these organs in soybean plants during this stress. The plants were randomized into five treatments (0, 50, 100, 150 and 200 mm NaCl). All the root regions studied and exposed to 100 mm Na+ exhibited increases in the epidermis and endodermis and formation of lysogenic aerenchyma with increasing salinity, revealing the protective roles of these structures in reducing Na+ influx. In the stem, increases in the cortex and pith in the first internode subject to 100 mm Na+ suggest anatomical responses that aim to minimize oxidative stress. Soybean plants subjected to progressive salt stress (>50 mm Na+ ) avoided cavitation and loss of function linked to vessel elements, reducing the metaxylem in all the root and stem regions analysed. Finally, our results confirm anatomical changes to the roots and stems.

The applicability of fingernail lead and cadmium levels as subchronic exposure biomarkers for preschool children.

Preschool children are exposed daily to metals in their homes and at daycare centers (DCC). Metal exposure and health effects are associated even at low levels, and children comprise a group of public health concern. Nail metals have been studied for exposure biomonitoring and compared to other biological media. The aim of this study was to explore the applicability of preschool fingernail lead and cadmium as subchronic exposure biomarkers. Nail lead and cadmium levels (NLL and NCL) of 602 preschool children (age: 1-4 years) who attended 21 DCC in São Paulo, Brazil, in 2013 were analyzed. Results were compared against blood lead and cadmium levels (BLL and BCL) found in a previous study. Inductively coupled plasma mass spectrometry (ICP-MS) analyses were performed for both samples. DCC and metal contaminated sites (MCS) were georeferencing. Logistic regression tests were applied to verify associations between nail metal levels and risk factors (sex, age, maternal education, secondary smoking, DCC geographic district, vehicle flow density, relative altitude and distance between DCC and nearest MCS) (p < 0.05). BLL was stratified by exposure level (low: <5 µg.dL-1; high: >13.9 µg.dL-1; medium: ≥5 µg.dL-1 and ≤13.9 µg.dL-1) and also tested the associations in order to verify if nail lead levels are affected by exposure intensity defined by blood metals concentrations. Radius distance and relative altitude of DCC to nearest MCS were associated with high NLL and NCL. Abnormal appearance of nails was associated with high NLL and low NCL. Lead and cadmium exposure magnitude had no significant impact on NLL. NLL should only be used for initial screening, and when financial resources are scarce, especially in areas located near contaminated sites. Preschool children were co-exposed to both lead and cadmium, reinforcing the need for broader studies evaluating exposure to environmental pollutants for more than one chemical element.

In vitro susceptibility and multilocus sequence typing of Fusarium isolates causing keratitis.

Fungal keratitis is recognized as a significant cause of ocular morbidity and blindness especially in developing countries. In this study, we aimed to present the molecular identification and susceptibility of Fusarium isolates causing fungal keratitis in a university hospital in southern Brazil. The samples were identified using the second largest subunit of the RNA polymerase gene (RPB2) and the translation elongation factor 1-alpha (TEF1), while the antifungal susceptibility was tested by the broth microdilution method according to the Clinical and Laboratory Standards Institute (CLSI) methodology. The majority of the isolates belonged to the Fusarium solani species complex (F. solani, F. keratoplasticum and F. falciforme) and Fusarium oxysporum species complex. Antifungal susceptibility has shown that amphotericin B and natamycin were the most effective antifungals across all isolates, followed by voriconazole. Variation among Fusarium complexes in their antifungal sensitivities was observed in our study. The identification of Fusarium species from human samples is important not only from an epidemiological viewpoint, but also for choosing the appropriate antifungal agent for difficult-to-treat Fusarium infections such as keratitis.

Graphite exfoliation in cellulose solutions.

Shaking graphite powder dispersed in an aqueous alkaline cellulose solution produces stable dispersions of hydrophilic, thin graphite sheets with lateral dimensions reaching many micrometers. The X-ray diffractogram and Raman spectrum of the exfoliated graphite differ from the well-known graphite patterns. Analytical transmission electron micrographs show cellulose bound to the surface of thin lamellae and this is confirmed by scanning probe micrographs. The dispersant properties of dissolved cellulose are assigned to its adsorption on graphite by juxtaposition of the hydrophobic planes on both substances, forming hydrophilic particles. This method uses only simple and easily accessible chemicals, processed under mild conditions. The resulting nanographite-cellulose dispersions are suitable for making conductive lignocellulosic nanocomposites and coatings.

Trace metal levels in serum and urine of a population in southern Brazil.

This study aimed to evaluate serum and urine concentrations of several trace metals of a non-directly exposed population in southern Brazil and establish reference values. Serum and urine samples were obtained from 240 volunteers (175 males and 65 females, age ranging from 18 to 74 years old). Levels of arsenic, chromium, cobalt, copper, lead, nickel, manganese and zinc were determined by means of dynamic reaction cell inductively coupled plasma mass spectrometry (DRC-ICP-MS). Comparison between genders resulted in no significant difference for all metals but serum copper, as concentrations are higher in females than males. For most metals assessed, a negative correlation between serum concentrations and age was found, but no significant correlation was found between urine concentrations and age.

Arsenic-induced responses in Pityrogramma calomelanos (L.) Link: Arsenic speciation, mineral nutrition and antioxidant defenses.

Arsenic (As) hyperaccumulation trait has been described in a limited number of fern species. The physiological basis of hyperaccumulation remains unclear, especially in non-Pteris species such as Pityrogramma calomelanos. Aiming at a better understanding of As-induced responses, P. calomelanos plants were exposed to 1 mM As for 21 days and compared with control plants. Chemical analyses revealed that As accumulation was ten times higher in pinnae then in roots and stipes. In pinnae, As was present mainly as arsenite, whereas arsenate was the dominant form in stipes and roots. Arsenic promoted an increase in antioxidant enzyme activities in both fern parts and several alterations in mineral nutrition, especially with regard to P and K. A higher content of non-protein thiols was observed in pinnae of plants exposed to As, whereas As induced the increase in lipid peroxidation in roots. The results showed that Pityrogramma calomelanos shares with Pteris vittata several aspects of As metabolism. High root-shoot As translocation showed to be essential to avoid toxic effects in roots, since the root is more sensitive to the metalloid. The higher capacity of P. calomelanos to sequester arsenite in the pinna and its efficient antioxidant system maintain the reactive oxygen species at a low level, thus enhancing the continuous accumulation of As. Molecular investigations are needed to elucidate the evolution of As-tolerance mechanisms in Pteridaceae species, especially with regard to membrane transporters and ROS signaling.

Biomarkers of exposure to metal dust in exhaled breath condensate: methodology optimization.

In occupational assessments where workers are exposed to metal dust, the liquid condensate of exhaled breath (EBC) may provide unique indication of pulmonary exposure. The main goal of this study was to demonstrate the quality of EBC to biological monitoring of human exposure. A pilot study was performed in a group of metal dust-exposed workers and a group of nonexposed individuals working in offices. Only metal dust-exposed workers were followed along the working week to determine the best time of collection. Metal analyses were performed with inductively coupled plasma mass spectrometry (ICP-MS). Analytical methodology was tested using an EBC sample pool for several occupationally exposed metals: potassium, chromium, manganese, copper, zinc, strontium, cadmium, antimony, and lead. Metal contents in EBC of exposed workers were higher than controls at the beginning of the shift and remained augmented throughout the working week. The results obtained support the establishment of EBC as an indicator of pulmonary exposure to metals.

Toxic and essential elements in conventional and home-produced eggs by ICP-MS analysis.

Concentrations of As, Ba, Cd, Co, Mn, Pb, Se, Sr, V, Cu, Fe, Mg, Zn and Mo were determined in conventional and home-produced eggs as sold in Brazil. Thirty-four conventional and 21 home-produced samples were obtained in different Brazilian cities. Elements were determined by inductively coupled plasma mass spectrometry (ICP-MS). Concentrations of Ba, Cd, Co, Pb, Se, Fe, Zn and Mo in conventional and home-produced eggs differed (statistically significant). Correlations were found among the other elements in both production systems. The estimated daily intake for toxic elements based on Brazilian egg consumption did not exceed the toxicological reference values. The results clearly demonstrated that eggs are an important source of essential elements such as Mo, Fe, Se and Zn.

Determination of trace elements in bovine semen samples by inductively coupled plasma mass spectrometry and data mining techniques for identification of bovine class.

The reproductive performance of cattle may be influenced by several factors, but mineral imbalances are crucial in terms of direct effects on reproduction. Several studies have shown that elements such as calcium, copper, iron, magnesium, selenium, and zinc are essential for reproduction and can prevent oxidative stress. However, toxic elements such as lead, nickel, and arsenic can have adverse effects on reproduction. In this paper, we applied a simple and fast method of multi-element analysis to bovine semen samples from Zebu and European classes used in reproduction programs and artificial insemination. Samples were analyzed by inductively coupled plasma spectrometry (ICP-MS) using aqueous medium calibration and the samples were diluted in a proportion of 1:50 in a solution containing 0.01% (vol/vol) Triton X-100 and 0.5% (vol/vol) nitric acid. Rhodium, iridium, and yttrium were used as the internal standards for ICP-MS analysis. To develop a reliable method of tracing the class of bovine semen, we used data mining techniques that make it possible to classify unknown samples after checking the differentiation of known-class samples. Based on the determination of 15 elements in 41 samples of bovine semen, 3 machine-learning tools for classification were applied to determine cattle class. Our results demonstrate the potential of support vector machine (SVM), multilayer perceptron (MLP), and random forest (RF) chemometric tools to identify cattle class. Moreover, the selection tools made it possible to reduce the number of chemical elements needed from 15 to just 8.

Rapid sample preparation procedure for As speciation in food samples by LC-ICP-MS.

This paper describes a rapid method for arsenic (As) speciation by LC-ICP-MS in several types of food samples. Prior to analysis, samples were milled and the As species extracted from biological tissues by sonication in only 2 min with a solution containing MeOH (10%, v/v) plus HNO3 (2%, v/v). As species were separated by LC using an anion exchange column. Method detection limits for AsB, As³âº, DMA, MMA and As5⁺ were 1.3, 0.9, 0.6, 0.7 and 0.8 ng g⁻¹, respectively. Method accuracy and precision were traceable to Certified Reference Materials SRM1577 bovine liver from the National Institute of Standards and Technology, CE278 mussel tissue from the Institute of Reference Materials and Measurements and DOLT-3 dogfish liver tissue and DORM-3 fish protein from the National Research Council of Canada. Finally, the method was applied to speciate As in food samples (egg, fish muscle, beef and chicken) purchased in Brazilian markets.

Sex-dependent antidepressant effects of lower doses of progesterone in rats.

Major depression is more prevalent among women than men, and progesterone might be involved in the mechanisms that generate these differences. Progesterone is clinically used for women in several reproductive events, but its antidepressant effect is unclear. Animal studies showed the interference of progesterone on depressive behaviors of rodents, but they are inconclusive, and no study compared different treatment durations. This study investigated the antidepressant effect of low doses of progesterone in male and female rats under acute or chronic administration. Male and female Wistar rats in different phases of the estrous cycle were acutely administered different doses of progesterone (0.0, 0.4. 0.8 and 1.2mg/kg) and tested in the forced swimming test (FST). The lowest dose of progesterone (0.4 mg/kg) was chronically administered during two complete estrous cycles and diestrous II female and male rats were tested in the FST. Progesterone decreased depressive-like behaviors only in chronically treated diestrous II female rats and increased immobility in male rats. This low dose of progesterone did not interfere in the hormonal cycling in female rats. Results also showed that diestrous II female rats had greater immobility than male rats in the FST. The greater immobility of diestrous II female rats shows that rats in this estrous phase present more depressive-like behaviors that may be associated with their lower serum levels of progesterone. We showed that progesterone chronically administered at low doses reverses these depressive-like behaviors and has an antidepressant effect during the diestrous II phase of the estrous cycle.

Survey of 13 trace elements of toxic and nutritional significance in rice from Brazil and exposure assessment.

Twenty-seven rice samples from Brazil, four parboiled brown, seventeen white and six parboiled white were analysed by ICP-MS for trace element determination. Concentrations of arsenic varied from 58.8 to 216.9 ng g(-1), for cadmium from 6.0 to 20.2 ng g(-1), for antimony from 0.12 to 1.28 ng g(-1), and for uranium from 0.025 to 1.28 ng g(-1). The estimated daily intake through rice consumption was 9.5 µg for As, 2.4 µg for Cd, 0.029 µg for Sb, 0.013 µg for U, 3.1 µg for Co, 0.2 µg for Cu, 85.6 mg for Mg, 1.9 mg for Mn, 333 mg for P, 3.0 µg for Se, 1.6 mg for Zn, 0.9 mg for Rb, and 0.3 µg for V. Found values represent a considerable percentage of the dietary reference intakes and provisional tolerable daily intake for essential and toxic elements, respectively.

Laser therapy improves healing of bone defects submitted to autologous bone graft.

OBJECTIVE: The aim of the present study was to assess histologically the effect of low-level laser thrapy (LLLT) (lambda 830 nm) on the healing of bone defects associated with autologous bone graft. BACKGROUND DATA: LLLT has been used on the modulation of bone healing because of the photo-physical and photochemical properties of some wavelengths. The use of correct and appropriate parameters has been shown to be effective in the promotion of a positive biomodulative effect on the healing bone. METHODS: Sixty male Wistar rats were divided into four groups: G1 (control), G2 (LLLT on the surgical bed), G3 (LLLT on the graft), and G4 (LLLT on both the graft and the surgical bed). The dose per session was 10 J/cm(2), and it was applied to the surgical bed (G2/G4) and on the bone graft (G3/G4). LLLT was carried out every other day for 15 days (lambda 830 nm, phi = 0.5 cm(2), 50 Mw, 10 J/cm(2)). The dose was fractioned in four points. The animals were sacrificed 15, 21, and 30 days after surgery; specimens were taken and routinely processed (wax, cut, and stain with H&E and Sirius red stains). Light microscopic analysis was performed by a pathologist. RESULTS: In the groups in which the LLLT was used trans-operatively on the surgical bed (G2/G4), bone remodeling was both quantitatively and qualitatively more evident when compared to subjects of groups G1 and G3. CONCLUSION: The present study indicates that the use of LLLT trans-operatively resulted in a positive biomodulative effect on the healing of bone defects associated with autologous bone grafts.

Regressão da aterosclerose / Atherosclerosis regression

A doença aterosclerótica e suas complicações tromboembólicas correspondem à principal causa de morbidade e mortalidade no Brasile no mundo...

[Evaluation of the effectiveness of a new vaccine against human leptospirosis in groups at risk]. / Evaluación de la efectividad de una nueva vacuna contra la leptospirosis humana en grupos en riesgo.

In order to evaluate the effectiveness of a new vaccine against human leptospirosis, a prospective cohort study was done with persons in the Cuban province of Holguín who were at risk of becoming ill with leptospirosis. The study included 118,018 persons from 15 to 65 years old who were considered to face either permanent or temporary risk. The vaccinated cohort consisted of 101,137 persons. They received two vaccine doses, 6 weeks apart, of 0.50 mL via deep intramuscular injection into the deltoid muscle of the nondominant arm. The unvaccinated cohort consisted of 16,881 persons. Epidemiological surveillance began 21 days after the application of the second vaccine dose and continued for 1 year. The same criteria for suspected and confirmed cases were maintained throughout the study period. At the end of the surveillance period effectiveness was calculated as being higher than 97%. It is estimated that the vaccination program prevented eight out of ten cases that would have otherwise occurred. Vaccine reactogenicity was also measured in a subsample of 1,500 persons between 15 and 65 years old. The observed symptomatology was low. Slight pain at the injection site was the most frequent symptom (25%). The results of the study indicate the usefulness of the vaccine for disease prevention among people at risk, and its use is thus recommended.

Hipertensäo pulmonar primária e gravidez / Primary pulmonary hypertension in pregnancy: a case report

Esse é um caso de hipertensao pulmonar primária (HPP) associada a gestaçao em uma paciente de 26 anos, G(1) P(0') admitida no Hospital Barao de Lucena (HBL), Recife - PE, no curso do sexto mês de gestaçao, com descompensaçao cardíaca e hemoptóicos, que evoluiu satisfatoriamente, sendo realizada cesariana na 36( semana, com feto em boas condiçoes. Trata-se de patologia rara, de prognóstico reservado, mortalidade materna elevada, em torno de 56 por cento. Faz-se necessária uma assistência à gestaçao-parto e puerpério por profissionais especializadas e em serviço médico de nível terciário. Apesar da evoluçao satisfatória deste caso, há contra-indicaçao absoluta de gravidez nessas pacientes.

[Rhinosporidiosis: a study of 33 cases diagnosed using biopsies at the Central Hospital of Maputo, since 1944 through 1986]. / Rinosporidiosis: estudio de 33 casos diagnosticados por biopsias en el Hospital Central de Maputo, desde 1944 hasta 1986.

A statistical review of the archives of the Laboratory of Pathologic Anatomy of Maputo Central Hospital is made with the view to determine the frequency of occurrence of rhinosporidiosis in biopsies in the years 1944-86. Diagnosis was made based on the specific microscopic picture shown by the lesions induced by Rhinosporidium seeberi. Of 91,000 reports only 33 cases of the disease were found, which accounts for 0.036% of the total biopsies made in the department. Tissular examinations showed that lesions always appear as polypoid masses lined with hyperplastic epithelium, with an intense inflammatory reaction involving the sporangia, which in slides appear as double-membrane spheres with the occasional rupture-freed spores. It was found that in the series studied the disease appeared most frequently in the period ranging from 10 to 19 years of age, with no sex prevalence. General statistics indicate that the greatest damage was found in bulbar conjunctiva and that location in nostrils was the most frequently found in the age group with the youngest people.