Analysis of Fifty Years of Severe Malaria Worldwide Research.

This study analyzed fifty years of severe malaria research worldwide. Malaria is a parasitic disease that continues to have a significant impact on global health, particularly in sub-Saharan Africa. Severe malaria, a severe and often fatal form of the disease, is a major public health concern. The study used different bibliometric indicators such as the number of publications, citations, authorship, and keywords to analyze the research trends, patterns, and progress made in the field of severe malaria. The study covers the period from 1974 to 2021 and includes articles from Scopus. The results of the study indicated that there has been a steady increase in the number of publications on severe malaria over the past fifty years, with a particular increase in the last decade. The study also showed that most of the publications are from USA and Europe, while the disease occurs in Africa, South-East Asia, and the Americas. The study also identified the most frequent keywords used in the publications, and the most influential journals and authors in the field. In conclusion, this bibliometric study provides a comprehensive overview of the research trends and patterns in the field of severe malaria over the past fifty years and highlights the areas that need more attention and research efforts.

Transfer of parasitology research to patents worldwide.

Mankind has known about different parasitic diseases since ancient times. There is no doubt that parasites are the infectious agents that have caused the most deaths throughout history. But even today, parasitic diseases affect more than one billion people worldwide. In this paper, the relationship between articles published in the area of parasitology and international patents in this field from 1996 to 2019 was analyzed. For this purpose, Scopus has been used. This is a database developed by Elsevier, which, in addition to having numerous indexed journals and books, has developed SciVal, an analysis tool with which the publications that have been cited in the patents of the 5 largest patent offices in the world have been analyzed. The analysis has allowed us to study 2814 publications, to know their time trend, their Authors, Affiliations, and Countries, as well as the journals in which they have been published. Also, the topics and topic clusters related to parasitology that appear in publications cited in international patents have been known. Thus, the existence of six Topic Clusters that group 94% of all publications has been discovered. Of all of them, the Topic Cluster referring to malaria stands out above all others, with 968 articles (34% of the total), probably due to the fact that malaria continues to be, to this day, one of the great challenges for both industry and basic research throughout the world.

Plasmodium vivax Cysteine-Rich Protective Antigen Polymorphism at Exon-1 Shows Recombination and Signatures of Balancing Selection.

Plasmodium vivax Cysteine-Rich Protective Antigen (CyRPA) is a merozoite protein participating in the parasite invasion of human reticulocytes. During natural P. vivax infection, antibody responses against PvCyRPA have been detected. In children, low anti-CyRPA antibody titers correlated with clinical protection, which suggests this protein as a potential vaccine candidate. This work analyzed the genetic and amino acid diversity of pvcyrpa in Mexican and global parasites. Consensus coding sequences of pvcyrpa were obtained from seven isolates. Other sequences were extracted from a repository. Maximum likelihood phylogenetic trees, genetic diversity parameters, linkage disequilibrium (LD), and neutrality tests were analyzed, and the potential amino acid polymorphism participation in B-cell epitopes was investigated. In 22 sequences from Southern Mexico, two synonymous and 21 nonsynonymous mutations defined nine private haplotypes. These parasites had the highest LD-R2 index and the lowest nucleotide diversity compared to isolates from South America or Asia. The nucleotide diversity and Tajima's D values varied across the coding gene. The exon-1 sequence had greater diversity and Rm values than those of exon-2. Exon-1 had significant positive values for Tajima's D, ß-α values, and for the Z (HA: dN > dS) and MK tests. These patterns were similar for parasites of different origin. The polymorphic amino acid residues at PvCyRPA resembled the conformational B-cell peptides reported in PfCyRPA. Diversity at pvcyrpa exon-1 is caused by mutation and recombination. This seems to be maintained by balancing selection, likely due to selective immune pressure, all of which merit further study.

Analysis of Global Research on Malaria and Plasmodium vivax.

Background: Malaria is one of the infectious diseases of greatest interest to the scientific community and of greatest concern to international health authorities. Traditionally, the focus has been on Plasmodium falciparum, the parasite that causes the most severe form of the disease in Africa. However, in the last twenty years, the Plasmodium vivax parasite, responsible for a large number of cases in Latin America, the Middle East, South and Southeast Asia, the Horn of Africa, and Oceania, has also generated enormous interest due, among other things, to the published evidence that it can cause severe malaria. Methods: In this paper, the international scientific publication on malaria and P. vivax has been analyzed using the Scopus database to try to define global trends in this field of study. Results: It has been shown that events such as the emergence of resistance to certain drugs can break a trend. The important role of non-malaria-endemic countries such as the USA or Switzerland in malaria research is also evident. Conclusions: International cooperation will be essential for the eradication of the disease. Moreover, in this sense, the general vision given by the bibliometric analysis of malaria caused by P. vivax is fundamental to paint the picture regarding the current situation and encourage international cooperation and control efforts.

Plasmodium genomics: an approach for learning about and ending human malaria.

Malaria causes high levels of morbidity and mortality in human beings worldwide. According to the World Health Organization (WHO), about half a million people die of this disease each year. Malaria is caused by six species of parasites belonging to the Plasmodium genus: P. falciparum, P. knowlesi, P. vivax, P. malariae, P. ovale curtisi, and P. ovale wallikeri. Currently, malaria is being kept under control with varying levels of elimination success in different countries. The development of new molecular tools as well as the use of next-generation sequencing (NGS) technologies and novel bioinformatic approaches has improved our knowledge of malarial epidemiology, diagnosis, treatment, vaccine development, and surveillance strategies. In this work, the genetics and genomics of human malarias have been analyzed. Since the first P. falciparum genome was sequenced in 2002, various population-level genetic and genomic surveys, together with transcriptomic and proteomic studies, have shown the importance of molecular approaches in supporting malaria elimination.

The Identification of Scientific Communities and Their Approach to Worldwide Malaria Research.

It is essential to establish a pattern to detect the strengths and weaknesses of working groups publishing on malaria, to promote coordination to facilitate the eradication of the disease. Given the complexity of the scientific network of groups and institutions studying malaria, it is necessary to use a mathematical algorithm that allows us to know the real structure of research on the disease in the world. In this work, articles with the word "malaria" in the title or author keywords gathered from Elsevier Scopus database were analyzed. By means of specific software, graphs were created. The analysis of the data allowed established different scientific communities, among which two were very diverse: one formed by those groups concerned about the vector transmission and control, and another one focused on the drug resistance of the parasite. Basic, applied, and operational research to eradicate malaria is an ambitious goal of the international institutions and the scientific community. The combination of effort and the establishment of a worldwide-scientific network that allows an effective interconnection (exchange) of knowledge, infrastructure technology, collaborators, financial resources, and datasets will contribute more effectively to end the disease.

Genetic approach towards a vaccine against malaria.

Malaria is a major concern for international health authorities. Millions of people contract it every year in the world due to a parasite of the Plasmodium genus. Due to the complexity of the parasite biology and genetics, there is currently no vaccine against the disease. However, due to the great resistance both to the medicines and to the insecticides used to combat the disease, it has become essential to obtain a vaccine as the necessary tool to prevent transmission and eliminate the disease. The bibliometric data indicate that interest in vaccines has been growing steadily since the 1980s. But nowadays, a powerful tool is used: the Plasmodium genome. This allows us to improve the fight against the disease. Knowing the sequences of the genes that favor the appearance of drug resistance, or those that encode for proteins with greater antigenic response, is a tool that can become fundamental. This article reviews the state of the art on vaccines and genetics, in the fight against malaria, and analyzes the fixed photo that the worldwide research on the disease poses.

Human parasitology worldwide research.

In this article, the trends in human parasitology have been studied through the analysis of the number of publications in this area. The parameters studied were: number of articles, language, countries and institutions with the highest number of publications, and keywords with greater presence in the articles of human parasitology. The results of the analysis confirm the growing interest in this area, observing an exponential growth in the number of publications in the last decades. We also verified that the main country in terms of scientific production is the USA, although among the most important institutions, we find non-US centres such as the Oswaldo Cruz Foundation and the London School of Hygiene and Tropical Medicine. For observing the relative importance of the journals that publish articles in this specific topic, an index has been created based on the h-index of the journal with publications related to human parasitology and divided by every 100 items. This rank is led fist by 'Journal of Medical Entomology' closely followed by 'Parasitology'. The analysis of the keywords allows to draw conclusions about the great importance of malaria in the current world research. A change in analytical methodology is also observed, and molecular techniques are now being imposed. These techniques, in the near future, have to influence in an improvement in the treatments and prevention of the diseases caused by parasites. Finally, it can be seen that diseases traditionally studied as helminthiasis and amebiasis are currently as well studied as others such as toxoplasmosis or leishmaniasis.

Trends in plant research using molecular markers.

MAIN CONCLUSION: A deep bibliometric analysis has been carried out, obtaining valuable parameters that facilitate the understanding around the research in plant using molecular markers. The evolution of the improvement in the field of agronomy is fundamental for its adaptation to the new exigencies that the current world context raises. In addition, within these improvements, this article focuses on those related to the biotechnology sector. More specifically, the use of DNA markers that allow the researcher to know the set of genes associated with a particular quantitative trait or QTL. The use of molecular markers is widely extended, including: restriction fragment length polymorphism, random-amplified polymorphic DNA, amplified fragment length polymorphism, microsatellites, and single-nucleotide polymorphisms. In addition to classical methodology, new approaches based on the next generation sequencing are proving to be fundamental. In this article, a historical review of the molecular markers traditionally used in plants, since its birth and how the new molecular tools facilitate the work of plant breeders is carried out. The evolution of the most studied cultures from the point of view of molecular markers is also reviewed and other parameters whose prior knowledge can facilitate the approach of researchers to this field of research are analyzed. The bibliometric analysis of molecular markers in plants shows that top five countries in this research are: US, China, India, France, and Germany, and from 2013, this research is led by China. On the other hand, the basic research using Arabidopsis is deeper in France and Germany, while other countries focused its efforts in their main crops as the US for wheat or maize, while China and India for wheat and rice.

pH-dependent structural conformations of B-phycoerythrin from Porphyridium cruentum.

B-phycoerythrin from the red alga Porphyridium cruentum was crystallized using the technique of capillary counter-diffusion. Crystals belonging to the space group R3 with almost identical unit cell constants and diffracting to 1.85 and 1.70 Å were obtained at pH values of 5 and 8, respectively. The most important difference between structures is the presence of the residue His88α in two different conformations at pH 8. This residue is placed next to the chromophore phycoerythrobilin PEB82α and the new conformation results in the relocation of the hydrogen-bond network and hydration around PEB82α, which probably contributes to the observed pH dependence of the optical spectrum associated with this chromophore. Comparison with the structures of B-phycoerythrin from other red algae shows differences in the conformation of the A-ring of the chromophore PEB139α. This conformational difference in B-phycoerythrin from P. cruentum enables the formation of several hydrogen bonds that connect PEB139α with the chromophore PEB158ß at the (αß)(3) hexamer association interface. The possible influence of these structural differences on the optical spectrum and the ability of the protein to perform energy transfer are discussed, with the two pH-dependent conformations of His88α and PEB82α being proposed as representing critical structural features that are correlated with the pH dependence of the optical spectrum and transient optical states during energy transfer.

Binding properties of ferrocene-glutathione conjugates as inhibitors and sensors for glutathione S-transferases.

The binding properties of two electroactive glutathione-ferrocene conjugates that consist in glutathione attached to one or both of the cyclopentadienyl rings of ferrocene (GSFc and GSFcSG), to Schistosoma japonica glutathione S-transferase (SjGST) were studied by spectroscopy fluorescence, isothermal titration calorimetry (ITC) and differential pulse voltammetry (DPV). Such ferrocene conjugates resulted to be competitive inhibitors of glutathione S-transferase with an increased binding affinity relative to the natural substrate glutathione (GSH). We found that the conjugate having two glutathione units (GSFcSG) exhibits an affinity for SjGST approximately two orders of magnitude higher than GSH. Furthermore, it shows negative cooperativity with the affinity for the second binding site two orders of magnitude lower than that for the first one. We propose that the reason for such negative cooperativity is steric since, i) the obtained thermodynamic parameters do not indicate profound conformational changes upon GSFcSG binding and ii) docking studies have shown that, when bound, part of the first bound ligand invades the second site due to its large size. In addition, voltammetric measurements show a strong decrease of the peak current upon binding of ferrocene-glutathione conjugates to SjGST and provide very similar K values than those obtained by ITC. Moreover, the sensing ability, expressed by the sensitivity parameter shows that GSFcSG is much more sensitive than GSFc, for the detection of SjGST.