Publications by authors named "Valdivia H"

Malaria continues to be a major threat to public health in tropical regions, primarily affecting sub-Saharan Africa but also Asia, the Middle East, and Latin America. Malaria cases in Honduras have seen a significant decline and the country aims to eliminate the disease by 2030. This study examines the genetic diversity of and in Honduras using four molecular markers (, , , and ), and the chloroquine resistance marker in the context of the elimination phase.

View Article and Find Full Text PDF

Background: Amazonas is a region in northern Peru with the second-highest incidence of malaria. Approximately 95% of the cases are reported in the Condorcanqui province, where native communities living along the banks of Santiago River lack access to potable water, sewage, and electricity. This study aimed to analyse malaria's spatial, temporal, and climatic characteristics in Condorcanqui to guide future studies and prevention strategies.

View Article and Find Full Text PDF

In Colombia, human leishmaniasis is endemic in rural areas, with increasing reports of outbreaks and cases in urban areas. Cartagena, an urban city in the Colombian Caribbean with a wildland-urban interface, faced its first local cases between 2011 and 2015. Despite reports, visceral leishmaniasis (VL) remains neglected and understudied and almost devoid of active surveillance.

View Article and Find Full Text PDF

Background: Federal guidelines and equitable care mandate that patients who use a language other than English receive interpretation in their preferred language. Substantial variability exists in interpreter use in intensive care settings. We aimed to increase the rate of interpretations in our pediatric intensive care unit (PICU) through a series of targeted interventions.

View Article and Find Full Text PDF
Article Synopsis
  • Plasmodium vivax is increasingly problematic in tropical regions, particularly where Plasmodium falciparum is declining, due to its ability to cause relapse infections that hinder treatment efforts.
  • Researchers developed four specialized molecular inversion probe (MIP) genotyping panels targeting key genetic variations in P. vivax, aiming to better understand its population structure and resistance mechanisms.
  • Analysis using these panels on 866 infections in the Peruvian Amazon revealed significant findings, including transmission networks, gene mutations related to drug resistance, and potential vaccine targets, suggesting these tools can enhance research and control of P. vivax globally.
View Article and Find Full Text PDF

Plasmodium falciparum infection threatens military populations deployed to highly malaria-endemic regions, such as Peruvian Army peacekeepers deployed to Central African Republic. During deployment, malaria cases were identified by microscopy and rapid diagnostic tests. After deployment, we performed malaria diagnosis by malachite green loop-mediated isothermal amplification and photo-induced electron transfer PCR assays.

View Article and Find Full Text PDF

Leishmaniasis is a diverse group of clinical diseases caused by protozoan parasites of the Leishmania genus. Species-specific identification of Leishmania spp. is challenging due to the high number of different pathogenic species that sometimes co-circulate in the same foci, hampering efforts to effectively control the disease.

View Article and Find Full Text PDF

Sleeve gastrectomy is a common bariatric procedure known for its safety and effectiveness, but postoperative complications like abscess formation, though rare, can occur. We report the case of a 37-year-old female who presented with atypical abdominal pain following a sleeve gastrectomy. Imaging revealed an abscess located away from the staple line.

View Article and Find Full Text PDF

During exercise or stress, the sympathetic system stimulates cardiac contractility via β-adrenergic receptor (β-AR) activation, resulting in phosphorylation of the cardiac ryanodine receptor (RyR2). Three RyR2 phosphorylation sites have taken prominence in excitation-contraction coupling: S2808 and S2030 are described as protein kinase A specific and S2814 as a Ca/calmodulin kinase type-2-specific site. To examine the contribution of these phosphosites to Ca signalling, we generated double knock-in (DKI) mice in which Ser2808 and Ser2814 phosphorylation sites have both been replaced by alanine (RyR2-S2808A/S2814A).

View Article and Find Full Text PDF

In polymicrobial sepsis, the extracellular histones, mainly released from activated neutrophils, significantly contribute to cardiac dysfunction (septic cardiomyopathy), as demonstrated in our previous studies using Echo-Doppler measurements. This study aims to elucidate the roles of extracellular histones and their interactions with Toll-like receptors (TLRs) in cardiac dysfunction. Through ex vivo assessments of ECG, left ventricle (LV) function parameters, and in vivo Echo-Doppler studies in mice perfused with extracellular histones, we aim to provide comprehensive insights into the mechanisms underlying sepsis-induced cardiac dysfunction.

View Article and Find Full Text PDF

Background: Efforts on a global scale for combating malaria have achieved substantial progress over the past twenty years. Two Central American nations have accomplished their goal of eliminating malaria: El Salvador and Belize. Honduras has decreased the incidence of malaria and now reports fewer than 4000 malaria cases annually, aspiring to reach elimination by 2030.

View Article and Find Full Text PDF

Background: Ryanodine receptor 2 (RyR2) is one of the first substrates undergoing phosphorylation upon catecholaminergic stimulation. Yet, the role of RyR2 phosphorylation in the adrenergic response remains debated. To date, three residues in RyR2 are known to undergo phosphorylation upon adrenergic stimulation.

View Article and Find Full Text PDF
Article Synopsis
  • * A study conducted from November 2019 to May 2020 found persistent malaria cases, with high infection rates and limited genetic diversity among the local parasite populations.
  • * Notably, resistance to anti-malarial drugs was identified, emphasizing the need for targeted strategies to address unique mobility patterns and prevent imported malaria infections in these remote areas.
View Article and Find Full Text PDF
Article Synopsis
  • Transmission of malaria is on the rise in tropical regions and poses challenges for treatment, leading to relapse infections.
  • Researchers developed four specialized molecular inversion probe (MIP) genotyping panels to analyze genetic variations related to antimalarial resistance and vaccines, focusing on specific SNPs.
  • The study analyzed 866 malaria infections in the Peruvian Amazon, identifying key transmission networks and genetic features that could enhance malaria control efforts in other affected areas.
View Article and Find Full Text PDF

Background: Accuracy of molecular tools for the identification of parasites that cause human cutaneous leishmaniasis (CL) could largely depend on the sampling method. Non-invasive or less-invasive sampling methods such as filter paper imprints and cotton swabs are preferred over punch biopsies and lancet scrapings for detection methods of Leishmania based on polymerase chain reaction (PCR) because they are painless, simple, and inexpensive, and of benefit to military and civilian patients to ensure timely treatment. However, different types of samples can generate false negatives and there is a clear need to demonstrate which sample is more proper for molecular assays.

View Article and Find Full Text PDF

Objectives: The accuracy of malaria rapid diagnostic tests is threatened by Plasmodium falciparum with pfhrp2/3 deletions. This study compares gene deletion prevalence determined by multiplex real time polymerase chain reaction (qPCR) and conventional polymerase chain reaction (cPCR) using existing samples with clonality previously determined by microsatellite genotyping.

Methods: Multiplex qPCR was used to estimate prevalence of pfhrp2/3 deletions in three sets of previously collected patient samples from Eritrea and Peru.

View Article and Find Full Text PDF
Article Synopsis
  • Hard-to-reach communities in Peru pose significant challenges for malaria elimination due to insufficient data on transmission patterns; a study conducted in Nueva Jerusalén (NJ), a remote indigenous community, aimed to address this gap through sample collection and analysis.
  • The study found that active case detection did not significantly reduce malaria cases, with a continuous presence of infections, particularly Plasmodium vivax (Pv) and Plasmodium falciparum (Pf), showing low genetic diversity and distinct genetic differences from parasites in other areas.
  • Resistance markers for chloroquine and sulfadoxine-pyrimethamine were present in NJ's Pf parasites, alongside common gene deletions, indicating the need for customized interventions that consider population mobility and imported infections to
View Article and Find Full Text PDF
Article Synopsis
  • Researchers explored how type II ryanodine receptors (RyR2) respond to phosphorylation, highlighting its role in structural changes.
  • Using the β-agonist isoproterenol and specific mouse mutations, they measured dyad lengths and RyR2 distribution via advanced imaging techniques.
  • The study found that certain mutations affected dyad size and tetramer organization, revealing a connection between the phosphorylation state of RyR2 and its structural behavior in response to stimulation.
View Article and Find Full Text PDF

Calcins are a group of scorpion toxin peptides specifically binding to ryanodine receptors (RyRs) with high affinity, and have the ability to activate and stabilize RyR in a long-lasting subconductance state. Five newly calcins synthesized compounds exhibit typical structural characteristics of a specific family through chemical synthesis and virtual analysis. As the calcins from the same species, Petersiicalcin1 and Petersiicalcin2, Jendekicalcin2 and Jendekicalcin3, have only one residue difference.

View Article and Find Full Text PDF

Calcin is a group ligand with high affinity and specificity for the ryanodine receptors (RyRs). Little is known about the effect of its acidic residues on the spacial structure as well as the interaction with RyRs. We screened the opicalcin1 acidic mutants and investigated the effect of mutation on activity.

View Article and Find Full Text PDF

The intensive care unit (ICU) Liberation "ABCDEF" Bundle improves outcomes in critically ill adults. We aimed to identify common barriers to Pediatric ICU Liberation Bundle element implementation, to describe differences in barrier perception by ICU staff role, and to describe changes in reported barriers over time. A 91-item survey was developed based on existing literature, iteratively revised, and tested by the PICU Liberation Committee at Seattle Children's Hospital, a tertiary free-standing academic children's hospital.

View Article and Find Full Text PDF

Background: Reducing Ca content in the sarcoplasmic reticulum (SR) through ryanodine receptors (RyRs) by calcin is a potential intervention strategy for the SR Ca overload triggered by β-adrenergic stress in acute heart diseases.

Methods: OpiCal-PEG-PLGA nanomicelles were prepared by thin film dispersion, of which the antagonistic effects were observed using an acute heart failure model induced by epinephrine and caffeine in mice. In addition, cardiac targeting, self-stability as well as biotoxicity were determined.

View Article and Find Full Text PDF

The epidermal growth factor receptor (EGFR) is one of the main tumor drivers and is an important therapeutic target for many cancers. Calcium is important in EGFR signaling pathways. Sorcin is one of the most important calcium sensor proteins, overexpressed in many tumors, that promotes cell proliferation, migration, invasion, epithelial-to-mesenchymal transition, malignant progression and resistance to chemotherapeutic drugs.

View Article and Find Full Text PDF

This study presents the first case report of canine trypanosomiasis caused by Trypanosoma evansi in Peru. The case was admitted to a veterinary clinic in the Peruvian Amazon region of San Martin with severe clinical symptomatology which resulted in the dog's death. Microscopy screening showed the presence of trypomastigotes in blood and bone marrow and postmortem histopathology found damage at the cardiac, lung, kidney and spleen levels.

View Article and Find Full Text PDF

Unlabelled: We have previously demonstrated that type II ryanodine receptors (RyR2) tetramers can be rapidly rearranged in response to a phosphorylation cocktail. The cocktail modified downstream targets indiscriminately making it impossible to determine whether phosphorylation of RyR2 was an essential element of the response. We therefore used the β-agonist isoproterenol and mice with one of the homozygous mutations, S2030A , S2808A , S2814A , or S2814D , to address this question and to elucidate the role of these clinically relevant mutations.

View Article and Find Full Text PDF