Histochemical techniques in plant science: more than meets the eye

Histochemistry is an essential analytical tool interfacing extensively with plant science. The literature is indeed constellated with examples showing its use to decipher specific physiological and developmental processes, as well as to study plant cell structures. Plant cell structures are translucent unless they are stained. Histochemistry allows the identification and localization, at the cellular level, of biomolecules and organelles in different types of cells and tissues, based on the use of specific staining reactions and imaging. Histochemical techniques are also widely used for the in vivo localization of promoters in specific tissues, as well as to identify specific cell wall components such as lignin and polysaccharides. Histochemistry also enables the study of plant reactions to environmental constraints, e.g. the production of reactive oxygen species (ROS) can be traced by applying histochemical staining techniques. The possibility of detecting ROS and localizing them at the cellular level is vital in establishing the mechanisms involved in the sensitivity and tolerance to different stress conditions in plants. This review comprehensively highlights the additional value of histochemistry as a complementary technique to high-throughput approaches for the study of the plant response to environmental constraints. Moreover, here we have provided an extensive survey of the available plant histochemical staining methods used for the localization of metals, minerals, secondary metabolites, cell wall components, and the detection of ROS production in plant cells. The use of recent technological advances like CRISPR/Cas9-based genome-editing for histological application is also addressed. This review also surveys the available literature data on histochemical techniques used to study the response of plants to abiotic stresses and to identify the effects at the tissue and cell levels.The authors would like to thank Head of the Department, University of Allahabad, Allahabad, India, for providing the necessary facilities to carry out the work

A text mining tool to support reading and authorial writing

Este artigo apresenta um estudo sobre o potencial de uma ferramenta de mineração de texto para auxiliar no processo de leitura e escrita autoral. No mundo letrado, a leitura e escrita estão diretamente ligadas aos processos de aprendizagem, favorecendo a formação do pensamento crítico e argumentativo. Dados estatísticos mostram que em países em desenvolvimento, como o Brasil, os estudantes demonstram grande dificuldade em escrever ou interpretar textos. Visando minimizar tais dificuldades, este estudo apresenta uma proposta que alia práticas pedagógicas e recursos tecnológicos para contribuir com os processos de leitura e escrita. O artigo apresenta um estudo envolvendo 22 estudantes que participaram de atividades de leitura e escrita em um curso semi-presencial de 30 horas. Os resultados do estudo, realizado por uma perspectiva qualitativa, permitiram concluir que as ferramentas e estratégias propostas contribuíram para o desenvolvimento de uma escrita autoral pelos participantes.This article presents a study on the potential of a text mining tool to assist students in reading and writing. In the literate world, reading and writing are directly linked to learning processes, favoring the development of critical and argumentative thinking. Statistics show that in developing countries, such as Brazil, students show great difficulty writing or interpreting texts. In order to minimize these difficulties, this study presents a proposal that combines teaching practices and technology to contribute to the processes of reading and writing. The article presents a study in which 22 students participated in reading and writing activities, in a 30 hours course. The results of the study, based on a qualitative perspective, allowed us to conclude that the tools and strategies proposed contributed to the development of an authorial presence in their writing

Transcatheter aortic valve implantation with the novel-generation Navitor device. Procedural and early outcomes

Transcatheter aortic valve implantation (TAVI) has proved beneficial in patients with severe aortic stenosis, especially when second-generation devices are used. We aimed at reporting our experience with Navitor, a third-generation device characterized by intrannular, large cell, and cuffed design, as well as high deliverability and minimization of paravalvular leak. Between June and December 2021, a total of 39 patients underwent TAVI with Navitor, representing 20% of all TAVI cases. Mean age was 80.0 +/- 6.7 years, and 14 (36.8%) women were included. Severe aortic stenosis was the most common indication to TAVI (37 [97.4%] cases), whereas 2 (5.3%) individuals were at low surgical risk. Device and procedural success was obtained in all patients, with a total hospital stay of 6.6 +/- 4.5 days. One (2.9%) patient required permanent pacemaker implantation, but no other hospital events occurred. At 1-month follow-up, a cardiac death was adjudicated in an 87-year-old man who had been at high surgical risk. Echocardiographic follow-up showed no case of moderate or severe aortic regurgitation, with mild regurgitation in 18 (47%), and none or trace regurgitation in 20 (53%). The Navitor device, thanks to its unique features, is a very promising technology suitable to further expand indications and risk-benefit profile of TAVI

Infliximab in paediatric inflammatory bowel disease

AbstractInfliximab has been widely used in paediatric Crohn's disease, mainly in luminal and fistulous disease refractory to standard treatment and for extraintestinal manifestations. Moreover, there is growing experience with its use in refractory ulcerative colitis. Infliximab has shown similar efficacy and safety in children as in adult population. It is postulated that its early use in paediatric inflammatory bowel disease, as a bridging treatment until the onset of action of other immunomodulators, could reduce the use of steroids and change the natural history of the disease as well. The effect of infliximab on mucosal healing could also contribute to the normal growth and sexual maturation in these patients

Biochemical assessment of red blood cells during storage by 1H nuclear magnetic resonance spectroscopy. Identification of a biomarker of their level of protection against oxidative stress

Background. Blood transfusion is an established therapeutic practice. The characteristics of blood components at different storage times are expected to affect the efficacy of transfusion therapy. Metabolic profiling by nuclear magnetic resonance (NMR) spectroscopy requires little or no sample treatment and allows identification of more than 50 soluble metabolites in a single experiment. The aim of this study was to assess the metabolic behaviour of red blood cells during 42 days of storage in blood bank conditions. Materials and methods. Red blood cells (RBC), collected from eight healthy male donors, aged 25-50 years, were prepared as prestorage leukoreduced erythrocyte concentrates and stored under standard blood bank conditions. Samples taken at various storage times were separated in two fractions: the supernatant, recovered after centrifugation, and the red blood cell lysate obtained after protein depletion by ultrafiltration. The metabolic profile of the red blood cells was determined from analysis of 1H-NMR spectra. Results. The red blood cell supernatant was studied to track the consumption of the preservative additives and to detect and quantify up to 30 metabolites excreted by the erythrocytes. The NMR spectra of the RBC lysate provided complementary information on some biochemical pathways and set the basis for building a time-dependent red blood cell metabolic profile. Discussion. We proved the analytical power of 1H-NMR spectroscopy to study red blood cell metabolism under blood bank conditions. A potential biomarker able to provide information on the level of cellular oxidative stress protection was identified. Our data support the hypothesis that a more detailed knowledge of metabolic modifications during storage opens the way to the development of new and more effective protocols for red blood cell conservation and patient-oriented transfusion therapy

All-trans to 11-cis conversion of endogenous retinoids in nuclear membrane preparations from bovine retinal pigment epithelium

not avalaibl

Lipoproteins as Drug Carriers for Cyclosporine A: Optimization of the Entrapment

Lipoproteins are natural nanostructures responsible for the transport of cholesterol and other lipids in the blood. They are characterized by having a lipophilic core surrounded by an amphiphilic shell composed of phospholipids, cholesterol and one or more apolipoproteins. Being endogenous carriers makes them suitable for drug delivery purposes. Here, we investigate the effect of lipoproteins’ intricate composition on the entrapment efficiency of a model drug “Cyclosporine A” into the different types of lipoproteins, namely, HDL, LDL and VLDL. It was observed that the protein content of the lipoproteins had the highest effect on the entrapment of the drug with a correlation coefficient of 0.80, 0.81 and 0.96 for HDL, LDL and VLDL respectively. This was even confirmed by the effect of plasma on the association rate of lipoproteins and the drug. The second effective factor is the cholesterol concentration, while triglycerides and phospholipids had a negligible effect