Publications by authors named "Leonardo Abreu"

Carbohydrate metabolism not only functions in supplying cellular energy but also has an important role in maintaining physiological homeostasis and in preventing oxidative damage caused by reactive oxygen species. Previously, we showed that arthropod embryonic cell lines have high tolerance to HO exposure. Here, we describe that Rhipicephalus microplus tick embryonic cell line (BME26) employs an adaptive glucose metabolism mechanism that confers tolerance to hydrogen peroxide at concentrations too high for other organisms.

View Article and Find Full Text PDF

In the present work, we established two novel embryonic cell lines from the mosquito Aedes fluviatilis containing or not the naturally occurring symbiont bacteria Wolbachia, which were called wAflu1 and Aflu2, respectively. We also obtained wAflu1 without Wolbachia after tetracycline treatment, named wAflu1.tet.

View Article and Find Full Text PDF

We compare the relative efficacy of virtual reality therapy exposure (VRET) versus in vivo therapy exposure among individuals suffering from phobias. A systematic search was completed up to 03 April 2020, using the following databases: ACM Digital Library, ResearchGate, IEEE, Science Direct, MIT PressJournals, Center for Direct Scientific Communication (CCSD) and Mary Ann Liebert Publishers. Five authors searched the databases using the following terms: Virtual Reality, Phobia, Mental health, Computing, Therapy, HMD, CAVE, Virtual ambient, in virtuo, Avoidance, Exposure, VRET, in vivo, Anxiety, Agoraphobia, Social Phobia, Stimuli, Cognitive-behaviour.

View Article and Find Full Text PDF

The recent outbreak caused by SARS-CoV-2 continues to threat and take many lives all over the world. The lack of an efficient pharmacological treatments are serious problems to be faced by scientists and medical staffs worldwide. In this work, an approach based on the combination of molecular docking, dynamics simulations, and quantum biochemistry revealed that the synthetic peptides -PepI, PepGAT, and PepKAA, strongly interact with the main protease (Mpro) a pivotal protein for SARS-CoV-2 replication.

View Article and Find Full Text PDF

Several research groups around the world have studied diverse aspects of energy metabolism in arthropod disease vectors, with the aim of discovering potential control targets. As in all oviparous organisms, arthropod embryonic development is characterized by the mobilization of maternally-derived metabolites for the formation of new tissues and organs. Glycogen synthase kinase-3 (GSK-3) is a serine-threonine kinase described as an important regulator of metabolism and development in a wide range of organisms.

View Article and Find Full Text PDF

Embryogenesis is a metabolically intensive process carried out under tightly controlled conditions. The insulin signaling pathway regulates glucose homeostasis and is essential for reproduction in metazoan model species. Three key targets are part of this signaling pathway: protein kinase B (PKB, or AKT), glycogen synthase kinase 3 (GSK-3), and target of rapamycin (TOR).

View Article and Find Full Text PDF

Reactive oxygen species (ROS) are natural byproducts of metabolism that have toxic effects well documented in mammals. In hematophagous arthropods, however, these processes are not largely understood. Here, we describe that Rhipicephalus microplus ticks and embryonic cell line (BME26) employ an adaptive metabolic compensation mechanism that confers tolerance to hydrogen peroxide (HO) at concentrations too high for others organisms.

View Article and Find Full Text PDF

Small renal masses have been diagnosed increasingly in recent decades, allowing surgical treatment by partial nephrectomy. This treatment option is associated with better renal function preservation, in comparison with radical nephrectomy. However, for obtaining a bloodless field during surgery, occlusion of renal artery and veins is often required, which results in transitory ischemia.

View Article and Find Full Text PDF

Objective: To evaluate the microscopic characteristics and quantify the volume of a radiofrequency ablation (RFA) lesion.

Methods: Ten male pigs were submitted to laparoscopic RFA. An RFA needle was introduced in the lower pole of the left kidney to create a lesion expected to be a sphere of 2.

View Article and Find Full Text PDF

Background: Mannitol has been employed to ameliorate renal warm ischemia damage during partial nephrectomy, however, there is limited scientific evidence to support the use of mannitol during partial nephrectomy. The objective of the present study was to investigate the glomerular number after renal warm ischemia, with and without the use of mannitol in a Pig Model.

Methods: Twenty-four male pigs were assigned into three groups.

View Article and Find Full Text PDF

Objective: The study aimed to evaluate the ischemic and non-ischemic areas after selective arterial occlusion by using stereological analysis of glomeruli, and to compare them with main arterial clamping and sham-operated animals.

Materials And Methods: Twenty-four male pigs were used in the study. The animals were divided into 3 groups with 8 animals in each as follows: group sham, submitted to laparoscopic dissection of the renal pedicle but not submitted to ischemia; group arterial (A), submitted to left renal artery clamping; and group selective (S), submitted to left renal artery caudal branch occlusion.

View Article and Find Full Text PDF

Purpose: To compare, with stereological methods, the glomerular loss in kidneys submitted to radiofrequency ablation (RFA) or warm ischemia.

Materials And Methods: Twenty-six male pigs were divided into three groups. Eight animals were allocated in the sham group, which was submitted to laparoscopic dissection of the left renal hilum, without renal ischemia.

View Article and Find Full Text PDF

Purpose:: To evaluate the glomerular loss after arteriovenous or arterial warm ischemia in a swine model.

Methods:: Twenty four pigs were divided into Group Sham (submitted to all surgical steps except the renal ischemia), Group AV (submitted to 30 minutes of warm ischemia by arteriovenous clamping of left kidney vessels), and Group A (submitted to 30 minutes of ischemia by arterial clamping). Right kidneys were used as controls.

View Article and Find Full Text PDF

Rhodnius prolixus is a blood-feeding insect that transmits Trypanosoma cruzi and Trypanosoma rangeli to vertebrate hosts. Rhodnius prolixus is also a classical model in insect physiology, and the recent availability of R. prolixus genome has opened new avenues on triatomine research.

View Article and Find Full Text PDF

RNA interference-mediated gene silencing was shown to be an efficient tool for validation of targets that may become anti-tick vaccine components. Here, we demonstrate the application of this approach in the validation of components of molecular signaling cascades, such as the Protein Kinase B (AKT)/Glycogen Synthase Kinase (GSK) axis during tick embryogenesis. It was shown that heptane and hypochlorite treatment of tick eggs can remove wax, affecting corium integrity and but not embryo development.

View Article and Find Full Text PDF

The main goals for urinary stone treatment are to preserve renal function, reduce or avoid complications related to calculi, and to render the patient free of calculi as soon as possible. Anatrophic nephrolithotomy (ANL) is a valid and useful alternative for conventional staghorn calculi excision. Although excellent stone free rates can be achieved with ANL there are some drawbacks that may be of concern.

View Article and Find Full Text PDF

In this work we evaluated several genes involved in gluconeogenesis, glycolysis and glycogen metabolism, the major pathways for carbohydrate catabolism and anabolism, in the BME26 Rhipicephalus microplus embryonic cell line. Genetic and catalytic control of the genes and enzymes associated with these pathways are modulated by alterations in energy resource availability (primarily glucose). BME26 cells in media were investigated using three different glucose concentrations, and changes in the transcription levels of target genes in response to carbohydrate utilization were assessed.

View Article and Find Full Text PDF

Molecular dynamics (MD) simulations associated with the thermodynamic integration (TI) scheme and the polarizable continuum model (PCM) in combination with the SMD solvation model were used to study the hydration free energy of the homologous series of polyols, C(n)H(n+2)(OH)n (1 ≤ n ≤ 7). Both solvation models predict a nonlinear behavior for the hydration free energy with the increase of the number of hydroxyl groups. This study also indicates that there is a sizable solute polarization in aqueous solution and that the inclusion of the polarization effect is important for a reliable description of the free energy differences considered here.

View Article and Find Full Text PDF

Lithiasis after urinary diversion is an uncommon condition that poses therapeutic challenges. The authors report the case of a patient submitted to cystectomy and ureterosigmoidostomy 35 years ago due to bladder endometriosis. The patient presented with a ureteral stone and was treated by retrograde endoscopic extraction.

View Article and Find Full Text PDF
Article Synopsis
  • The study investigates the role of AKT (protein kinase B) in glycogen metabolism and cell viability in the tick species Rhipicephalus microplus during embryogenesis.
  • Results show that inhibiting AKT decreases glycogen levels and cell viability, while inhibiting GSK3 increases glycogen levels, highlighting an antagonistic relationship between the two proteins.
  • Understanding the AKT/GSK3 signaling pathway in ticks could lead to new strategies for tick control, given the conserved nature of this axis in their embryonic development.
View Article and Find Full Text PDF

Mobile phones obtained large popularization in Brazil thanks to pre-paid (pay as you go) contracts. This kind of contract represents 82% of mobile phone connections in Brazil, corresponding to 143 million in a total of 174 million mobile phone accesses in the country. In this scenario, a research about the usability of mobile phones with 17 to 24 year old youngsters, living in poor communities, enrolled in the NGO Spectaculu.

View Article and Find Full Text PDF

Purpose: The aim of the study was to compare the effects of renal ice slush hypothermia and the use of trimetazidine in the protection against ischemia/reperfusion (I/R) injury.

Materials And Methods: Fifteen farm pigs were submitted to left kidney ischemia and right nephrectomy during the same procedure. Animals were divided into three groups.

View Article and Find Full Text PDF
Article Synopsis
  • A. aegypti mosquitoes, which transmit dengue and other viruses, require improved vector control methods that can be informed by a deeper understanding of their embryonic development, particularly regarding energetic metabolism.
  • Research focused on glucose metabolism during A. aegypti embryogenesis revealed significant changes in enzyme activities, notably high glucose 6-phosphate dehydrogenase (G6PDH) levels initially, which decreased as development progressed, indicating its role in producing nucleotide precursors.
  • The study concluded that glucose metabolic processes evolve as the embryo develops, with distinct shifts in enzyme activity and carbohydrate utilization during critical milestones like the germ band retraction, highlighting the importance of metabolic regulation in mosquito development.
View Article and Find Full Text PDF

Glycogen synthase kinase 3 (GSK-3) is classically described as a key enzyme involved in glycogen metabolism in mammals. GSK-3 belongs to a highly conserved family of serine/threonine protein kinases, whose members are involved in hormonal regulation, nuclear signaling, and cell fate determination in higher eukaryotes. We have cloned and characterized the RmGSK-3 gene from Rhipicephalus (Boophilus) microplus tick embryos.

View Article and Find Full Text PDF