Laura Vargas-Parada | Universidad Nacional Autónoma de México (original) (raw)

Papers by Laura Vargas-Parada

PubMed, Aug 10, 2000

Cysticercosis is a parasitic disease caused by the larval stage or cysticercus of the cestode tap... more Cysticercosis is a parasitic disease caused by the larval stage or cysticercus of the cestode tapeworm Taenia solium. Cysticerci are able to survive in the host tissues for long periods in the presence of an immune response. Tissues of cestodes contain mineral concretions termed calcareous corpuscles. These corpuscles might serve for the focal deposition of exceeding amounts of calcium protecting the larvae against calcification. Studies on the morphology and composition of calcareous corpuscles in cestodes have resulted in a number of hypotheses on their origin and function. Calcareous corpuscles are believed to form either intracellularly or extracellularly and the cell type involved, the place of formation and the mechanism of mineral deposition seem to be also diverse. This review intends to provide an updated guide to the published literature on calcareous corpuscles in cestodes, giving emphasis on their role in larval physiology. Understanding biomineralization might lead to novel ways for the treatment of diseases caused by cestode larvae.

Nature, Sep 23, 2020

Research roundup Highlights from research. By Laura Vargas-Parada reflect the clinical benefit of... more Research roundup Highlights from research. By Laura Vargas-Parada reflect the clinical benefit of a treatment. The highest priced drugs were not consistently the most effective treatments. The team compared the clinical value of a drug, as defined by the American Society of Clinical Oncology (ASCO) and the European Society for Medical Oncology (ESMO) criteria, to its monthly cost in each country. It found no significant association between price and clinical benefit in four of the countries, but in France an association was seen with the ASCO criteria. However, the team note that final prices in England might differ from those used in its study, because the National Health Service receives discounts on certain drugs that are not made public. Vokinger suggests that forming coalitions between countries could improve alignment of pricing and benefit.

Nature, May 13, 2020

In 2002, pneumologist María Victorina López Varela at the University of the Republic and Hospital... more In 2002, pneumologist María Victorina López Varela at the University of the Republic and Hospital Maciel in Montevideo, Uruguay, joined forces with researchers in five other Latin American countries to launch the first large-scale assessment of the prevalence of chronic obstructive pulmonary disease (COPD) in the region-the PLATINO study. What was the picture of COPD in Latin America in 2002? There was no data on COPD prevalence in the region. Scientists, including myself, had worked on the disease for many years in universities, yet we didn't know the reality of COPD on our continent. That's why we launched the PLATINO study.

Nature, Nov 1, 2013

President aims to boost spending and reform research laws. Mexican President Enrique Peña Nieto h... more President aims to boost spending and reform research laws. Mexican President Enrique Peña Nieto has resolved to improve the country's standing in science.

Parasitology Research, Mar 1, 2003

Paramyosin is a muscle protein that probably plays a role in the survival of the larval stage of ... more Paramyosin is a muscle protein that probably plays a role in the survival of the larval stage of Taenia solium during its prolonged host-parasite relationship. Here we describe the structure of the gene coding for the paramyosin of T. solium. The characterization of two clones obtained from a genomic library showed that the complete gene of paramyosin contains 13 introns delimited by conventional eukaryotic splice signals. Comparison with the paramyosin genes of Drosophila melanogaster and Caenorhabditis elegans showed a lack of conservation of the exon/intron organization in contrast to other muscle genes. No evidence of alternative splicing sites were found, excluding the possibility that T. solium expresses a mini-paramyosin like D. melanogaster.

Parasitology, May 1, 2001

Heat shock and stress responses are documented for the first time in larval stages of the cestode... more Heat shock and stress responses are documented for the first time in larval stages of the cestodes Taenia solium and Taenia crassiceps. Radioactive metabolic labelling after in vitro incubation of cysts at 43 °C, revealed the induction of heat shock proteins. In T. crassiceps, the major heat shock proteins were 80, 70 and 60 kDa. After prolonged incubation, a set of low molecular weight heat shock proteins (27, 31, 33 and 38 kDa), were also induced. In vitro incubation of cysts at 4 °C, induced the synthesis of stress proteins ranging from 31 to 80 kDa, indicating the parasite is also able to respond to cold shock. T. solium cysts exposure to temperature stress also resulted in an increased synthesis of 2 major heat shock proteins of 80 and 70 kDa. Western blots using the excretory–secretory products of T. solium showed that 2 heat shock proteins were recognized by antibodies in the sera of cysticercotic patients: one of 66 kDa and another migrating close to the run front. The T. solium 66 kDa protein was also recognized by specific antibodies directed to a 60 kDa bacterial heat shock protein, suggesting that it belongs to this family of proteins.

Parasitology Research, 1999

Platyhelminths, like many other organisms, are capable of producing mineral concretions. In cesto... more Platyhelminths, like many other organisms, are capable of producing mineral concretions. In cestodes these are referred to as calcareous corpuscles. Studies on these concretions in dierent cestodes both in vivo and in vitro have resulted in a number of hypotheses on their origin, formation, and structure. Calcareous corpuscles are believed to be of cellular origin, although the kind of cell involved and the mechanisms of mineralization remain under discussion. In the present paper we show that formation of calcareous corpuscles in cysticerci of Taenia solium is not of intracellular origin, as described for other cestodes, but occurs extracellularly in the lumen of protonephridial ducts in a way similar to that proposed for trematodes. This ®nding enhances the function of the protonephridial ducts, at least in the larvae of T. solium, to the roles formerly ascribed to the calcareous corpuscles.

Nature, Sep 14, 2022

The involvement of the prostate gland in sexual function, and the impact of treating tumours in i... more The involvement of the prostate gland in sexual function, and the impact of treating tumours in it, make cancer in this part of the body an especially difficult one to deal with psychologically. Miguel Ángel Jiménez-Ríos, a urological oncologist at Mexico's National Cancer Institute in Mexico City, spoke to Nature about how the psychology of the disease affects screening rates and patients' quality of life, and how best to address these issues.

Investigación y ciencia, 2006

Micrografía electrónica del escólex del parásito adulto en la cual se observa la doble corona de ... more Micrografía electrónica del escólex del parásito adulto en la cual se observa la doble corona de ganchos, el rostelo, y cuatro ventosas, que le permiten anclarse en la pared intestinal del huésped.

Nature, Jun 28, 2023

Most malaria researchers focus on the disease-causing parasite Plasmodium falciparum, the most pr... more Most malaria researchers focus on the disease-causing parasite Plasmodium falciparum, the most prevalent species of Plasmodium in Africa. But elsewhere, another parasite dominates: Plasmodium vivax. Efforts to address malaria caused by this species lag behind those of P. falciparum, including the development of effective vaccines. Arturo Reyes-Sandoval, a vaccinologist at the National Polytechnic Institute in Mexico City and the University of Oxford, UK, spoke to Nature about why a P. vivax malaria vaccine should be on researchers' most wanted list, and how close he and his colleagues are to developing one. How does P. vivax compare with other species of malaria parasite? There are around 200 species of malaria parasite that can infect mammals, birds and reptiles. P. vivax is the most widely distributed form of malaria parasite in humans, and it is dominant in the Western Pacific and in highly populated areas of Latin America and Asia. By comparison, P. falciparum is present mainly in Africa, and is responsible for high levels of mortality, especially in children. Two other species-Plasmodium malariae and Plasmodium ovale-are less prevalent. A fifth malaria parasite, Plasmodium knowlesi, infects monkeys in southeast Asia, and can be transmitted from animal hosts to people by mosquitoes, causing a special zoonotic form of malaria.

Nature, Jun 28, 2023

Hibernation might explain why mosquito populations rebound quickly after the dry season. Research... more Hibernation might explain why mosquito populations rebound quickly after the dry season. Research roundup Highlights from research. By Laura Vargas-Parada editing system CRISPR-Cas9 alongside the antimicrobial genes, which raises the probability of inheriting the modified genes from 50% to nearly 100% (see S29). Modelling suggests that these genetic modifications could break malaria transmission in sub-Saharan Africa, but no genedrive mosquitoes have yet been released in the wild.

Nature, Jul 14, 2021

Gluten, a protein found in cereals, damages the intestinal villi in people with coeliac disease. ... more Gluten, a protein found in cereals, damages the intestinal villi in people with coeliac disease. Research roundup Highlights from research. By Laura Vargas-Parada disease. Moreover, the disease can be reversed when the mouse receives a gluten-free diet, just as in people. The researchers think this unique model will provide a much-sought tool for trying new non-dietary treatments or preventive strategies in those with high-risk genetic profiles.

Nature, Oct 26, 2022

Numerous studies over more than two decades have demonstrated a robust relationship between clima... more Numerous studies over more than two decades have demonstrated a robust relationship between climate and the dynamics of human diseases, such as cholera, malaria and dengue. Changes in climate, including both long-term warming trends and short-term climate variability, might affect patterns of disease. Xavier Rodó, a computational ecologist and climate dynamics specialist at the Barcelona Institute for Global Health and the Catalan Institution for Research and Advanced Studies in Spain, spoke to Nature about how climate modelling could be used to help prepare for future disease outbreaks-and the obstacles he has faced in implementing such systems.