Drug Repurposing: An Effective Tool in Modern Drug Discovery.

Drug repurposing is using an existing drug for a new treatment that was not indicated before. It has received immense attention during the COVID-19 pandemic emergency. Drug repurposing has become the need of time to fasten the drug discovery process and find quicker solutions to the over-exerted healthcare scenario and drug needs. Drug repurposing involves identifying the drug, evaluating its efficiency using preclinical models, and proceeding to phase II clinical trials. Identification of the drug candidate can be made through computational and experimental approaches. This approach usually utilizes public databases for drugs. Data from primary and translational research, clinical trials, anecdotal reports regarding off-label uses, and other published human data information available are included. Using artificial intelligence algorithms and other bioinformatics tools, investigators systematically try to identify the interaction between drugs and protein targets. It can be combined with genetic data, clinical analysis, structure (molecular docking), pathways, signatures, targets, phenotypes, binding assays, and artificial intelligence to get an optimum outcome in repurposing. This article describes the strategies involved in drug repurposing and enlists a series of repurposed drugs and their indications.

Biomechanical analyses of one-piece dental implants composed of titanium, zirconia, PEEK, CFR-PEEK, or GFR-PEEK: Stresses, strains, and bone remodeling prediction by the finite element method.

This work aimed to assess the biomechanics, using the finite element method (FEM), of traditional titanium Morse taper (MT) dental implants compared to one-piece implants composed of zirconia, polyetheretherketone (PEEK), carbon fiber-reinforced PEEK (CFR-PEEK), or glass fiber-reinforced PEEK (GFR-PEEK). MT and one-piece dental implants were modeled within a mandibular bone section and loaded on an oblique force using FEM. A MT implant system involving a Ti6Al4V abutment and a cp-Ti grade IV implant was compared to one-piece implants composed of cp-Ti grade IV, zirconia (3Y-TZP), PEEK, CFR-PEEK, or GFR-PEEK. Stress on bone and implants was computed and analyzed while bone remodeling prediction was evaluated considering equivalent strain. In comparison to one-piece implants, the traditional MT implant revealed higher stress peak (112 MPa). The maximum stresses on the one-piece implants reached ~80 MPa, regardless their chemical composition. MT implant induced lower bone stimulus, although excessive bone strain was recorded for PEEK implants. Balanced strain levels were noticed for reinforced PEEK implants of which CFR-PEEK one-piece implants showed proper biomechanical behavior. Balanced strain levels might induce bone remodeling at the peri-implant region while maintaining low risks of mechanical failures. However, the strength of the PEEK-based composite materials is still low for long-term clinical performance.

In vivo predation and modification of the Mediterranean fruit fly Ceratitis capitata (Wiedemann) gut microbiome by the bacterial predator Bdellovibrio bacteriovorus.

AIMS: The Mediterranean fruit fly (the medfly) causes major losses of agricultural fruits. Its microbiome is mainly composed of various Enterobacteriaceae that contribute to nutrient acquisition and are associated with the fly's development. Moreover, the performance of males produced by the sterile insect technique is improved by providing mass-reared insects with specific gut bacteria. Bdellovibrio and like organisms (BALOs) are obligate predators of Gram-negative bacteria that efficiently preys upon diverse Enterobacteriaceae, making it a potential disruptor of the fly's microbiome. We hypothesized that the fly's microbiome can be targeted to control the insect. METHODS AND RESULTS: Inoculation of B. bacteriovorus as free-swimming or encapsulated cells into gut extracts significantly reduced gut bacterial abundance, sustaining predator survival. Similar treatments applied to adult flies showed that the predators also survived in the gut environment. While addition of the predators did not affect total gut bacterial abundance and end-point fly mortality, a shift in the gut community structure, measured by high-throughput community sequencing was observed. CONCLUSIONS: The bacterial predator of bacteria B. bacteriovorus can prey and survive in vivo in the medfly gut. SIGNIFICANCE AND IMPACT OF THE STUDY: This study establishes the potential of BALOs to affect the microbiome of insect hosts.

Environmental persistence and virulence of Salmonella spp. Isolated from a poultry slaughterhouse.

Salmonella spp. is responsible for severe foodborne disease, and is one of the main agents involved in foodborne outbreaks worldwide. Contamination occurs mainly as a result of poultry and egg consumption since they can carry some serotypes pathogenic to humans. The aim of the study was to evaluate the persistence and pathogenic potential of Salmonella spp. (n = 40) isolated from poultry slaughterhouse mats, using adhesion and invasion assays, antimicrobial susceptibility by disc diffusion, and biofilm production as phenotypic tests and genotypic analyses. Polystyrene mats presented 3.2 times greater chance of isolating Salmonella than canvas mats. Besides, we observed resistance to tetracycline (17.5%), ampicillin (10%), cefotaxime (7.5%), trimethoprim-sulfamethoxazole (5%), and chloramphenicol (2.5%). All strains possessed the invA, sipB, sipD, ssaR, sifA, sitC, iroN, tolC, flgK, fljB, and flgL genes. The genes sopB and sipA were both present in 92.5% of the isolates, while sopD and spvB were observed in 90% and 32.5% of strains, respectively. All strains adhered to and invaded HeLa cells. Regarding biofilm production, 31 (77.5%) strains were able to produce biofilm on polystyrene microplates. Using PFGE, we detected the persistence of clones in the environment for up to 18 fromthe 20 weeks. The ability of these strains to produce a biofilm and thus persist in the environment and disperse through contact surfaces in the processing plant favors the contamination of food, aggravated by the pathogenic potential of these isolates demonstrated by their adhesion capacity, invasion and resistance to various antibiotic agents.

Bioderived ionic liquid-based pretreatment enhances methane production from Agave tequilana bagasse.

In recent years, bioderived ionic liquids have gained attention as a new promising approach for lignocellulosic biomass pretreatment. In this work, Agave tequilana bagasse (ATB), an attractive bioenergy feedstock in Mexico, was pretreated with a bioderived ionic liquid (cholinium lysinate) for the first time. Optimization of the pretreatment conditions, in-depth biomass characterization and methane generation via anaerobic digestion are the main contributions of this work. The results indicated optimized pretreatment conditions of 124 °C, 205 min and 20% solids loading by applying a central composite design. The optimized pretreated ATB was able to produce an elevated sugar yield of 51.4 g total sugars per g ATB due to their high delignification (45.4%) and changes in their chemical linkages although an increase in cellulose crystallinity was found (0.51 untreated vs. 0.62 pretreated). Finally, the mass balance showed that 38.2 kg glucose and 13.1 kg xylose were converted into 12.5 kg of methane per 100 kg of untreated ATB, representing 86% of the theoretical methane yield and evidencing the potential of this biorefinery scheme.

Organometallic Gold(III) Complex [Au(Hdamp)(L14)]+ (L1 = SNS-Donating Thiosemicarbazone) as a Candidate to New Formulations against Chagas Disease.

Chagas disease remains a serious public health concern with unsatisfactory treatment outcomes due to strain-specific drug resistance and various side effects. To identify new therapeutic drugs against Trypanosoma cruzi, we evaluated both the in vitro and in vivo activity of the organometallic gold(III) complex [Au(III)(Hdamp)(L14)]Cl (L1 = SNS-donating thiosemicarbazone), henceforth denoted 4-Cl. Our results demonstrated that 4-Cl was more effective than benznidazole (Bz) in eliminating both the extracellular trypomastigote and intracellular amastigote forms of the parasite without cytotoxic effects on mammalian cells. In in vivo assays, 4-Cl in PBS solution loses the protonation and becomes the 4-neutral. 4-Neutral reduced parasitaemia and tissue parasitism in addition to protecting the liver and heart from tissue damage at 2.8 mg/kg/day. All these changes resulted in the survival of 100% of the mice treated with the gold complex during the acute phase. Analyzing the surviving animals of the acute infection, the parasite load after 150 days of infection was equivalent to those treated with the standard dose of Bz without demonstrating the hepatotoxicity of the latter. In addition, we identified a modulation of interferon gamma (IFN-γ) levels that may be targeting the disease's positive outcome. To the best of our knowledge, this is the first gold organometallic study that shows promise in an in vivo experimental model against Chagas disease.

Mild reaction conditions induce high sugar yields during the pretreatment of Agave tequilana bagasse with 1-ethyl-3-methylimidazolium acetate.

Sequential 2k factorial and central composite designs were used to optimize Agave tequilana bagasse (ATB) pretreatment by using 1-ethyl-3-methylimidazolium acetate ([Emim][OAc]). Reaction time, temperature and solids loading were the studied factors while sugar yield was the response variable. Results indicated that optimal conditions (119 °C, 142 min) using high solids loading (30%) were achieved at lower temperatures and reaction times than those previously reported in the literature. It was also revealed that solid recovery after pretreatment with [Emim][OAc] is a key factor. The increase in enzymatic digestibility of pretreated ATB was correlated to a decrease in crystallinity and lower lignin content as observed using microscopy techniques and weaken chemical bonds by Fourier transform infrared spectroscopy. Yields of glucose and xylose in the hydrolysate were 41.3, and 13.0 kg per 100 kg of untreated ATB, which are equivalent to glucan and xylan conversions of 75.9% and 82.9%, respectively.

Dopaminergic Immunofluorescence Studies in Kidney Tissue.

The kidney is a highly integrated system of specialized differentiated cells that are responsible for fluid and electrolyte balance in the body. While much of today's research focuses on isolated nephron segments or cells from nephron segments grown in tissue culture, an often overlooked technique that can provide a unique view of many cell types in the kidney is slice culture. Here, we describe techniques that use freshly excised kidney tissue from rats to perform a variety of experiments shortly after isolating the tissue. By slicing the rat kidney in a "bread loaf" format, multiple studies can be performed on slices from the same tissue in parallel. Cryosectioning and staining of the tissue allow for the evaluation of physiological or biochemical responses in a wide variety of specific nephron segments. The procedures described within this chapter can also be extended to human or mouse kidney tissue.

Frequency, serotyping and antimicrobial resistance pattern of Salmonella from feces and lymph nodes of pigs / Isolamento, sorotipagem e padrões de resistência a antimicrobianos de Salmonella em fezes e linfonodos de suínos

Salmonellosis is a foodborne disease caused by bacteria of the genus Salmonella, being pigs and pork-products potentially important for its occurrence. In recent decades, some serovars of Salmonella have shown increase of resistance to conventional antimicrobials used in human and animal therapy, with serious risks for public health. The aim of this study was to evaluate feces (n=50), mediastinal (n=50), mesenteric (n=50) and mandibular (n=50) lymph nodes obtained from slaughter houses for Salmonella spp. Positive samples were serotyped and subjected to an in vitro antimicrobial susceptibility test, including the extended-spectrum beta-lactamase (ESBL) production. Salmonella species were identified in 10% (20/200) of total samples. From these, 20% (10/50) were identified in the submandibular lymph nodes, 18% (9/50) in the mesenteric lymph nodes, 2% (1/50) in feces and 0% (0/50) in the mediastinal lymph nodes. The serotypes found were Salonella Typhimurium (55%), S. enterica subsp. enterica 4,5,12: i: - (35%), S. Brandenburg and S. Derby with 5% (5% each). All strains showed resistance to at least one antimicrobial; 90% were resistant to four or more antimicrobials, and 15% were multidrug-resistant. Resistance to ciprofloxacin, tetracycline and nalidixic acid was particularly prevalent amongst the tested serovars. Here, we highlighted the impact of pigs in the epidemiological chain of salmonellosis in domestic animals and humans, as well as the high antimicrobial resistance rates of Salmonella strains, reinforcing the necessity for responsible use of antimicrobials for animals as an emergent One Health issue, and to keep these drugs for human therapy approaches.(AU)

Nas últimas décadas, o aumento de cepas circulante de Salmonella concomitantemente a resistência microbiana tem despertado a preocupação dos órgãos de Saúde Pública. Deste modo, o objetivo do presente trabalho foi pesquisar a presença de Salmonella a partir de fezes (n=50), linfonodos mediastinos (n=50), mesentéricos (n=50) e submandibular (n=50) oriundos de um abatedouro suíno. As cepas isoladas foram sorotipadas e testadas quanto a resistência antimicrobiana. A presença de Salmonella isolada foram em 10% (20/200) do total de amostras, sendo 20% dos linfonodos submandibulares, 18% dos linfonodos mesentéricos e 2% das fezes. Os sorotipos encontrados foram S. Typhimurium (55%), S. enterica subsp. enterica 4,5,12: i: - (35%), S. Brandenburg (5%) e S. Derby (5%). Todas a cepas apresentaram resistência a pelo menos um antimicrobiano testado, sendo 90% resistente pelo menos quatro antimicrobianos. Destes, 15% foram classificadas como multidrogas resistentes. Os antimicrobianos mais resistentes entre os sorovares isolados foram a ciprofloxacina, tetraciclina e o ácido nalidixico. A presença de cepas de Salmonella resistente a antimicrobianos na espécie suína tem gerado um grande impacto epidemiológico entre homem e animal, reforçando cada vez mais a necessidade do uso adequado de drogas principalmente relacionado com o tema "One Health".(AU)

Common variants of the G protein-coupled receptor type 4 are associated with human essential hypertension and predict the blood pressure response to angiotensin receptor blockade.

Non-synonymous GRK4 variants, R65L, A142V and A486V, are associated with essential hypertension in diverse populations. This study replicated the association of GRK4 variants, including GRK4(142V), with human essential hypertension in a Japanese population (n=588; hypertensive, n=486 normotensive controls) and determined whether the presence of GRK4 variants predicted the blood pressure (BP) response to angiotensin receptor blockers (ARBs) in patients with essential hypertension. We analyzed 829 patients and compared the response to ARBs between individuals with no GRK4 variants (n=136) and those with variants at one or any of the three loci (n=693). Carriers of hGRK4(142V) had a greater decrease in systolic BP in response to ARBs than non-carrier hypertensive patients. By contrast, those with variants only at GRK4(486V) were less likely to achieve the BP goal in response to an ARB than those with no variants. These studies showed for the first time the association between GRK4(142V) and a larger decrease in BP with ARBs in hypertensive patients.

Dopamine D1 and D5 receptors differentially regulate oxidative stress through paraoxonase 2 in kidney cells.

BACKGROUND: The renal dopaminergic system plays an important role in the pathogenesis of hypertension. Dopamine D1-like receptors (D1R and D5R) decrease reactive oxygen species (ROS) production via inhibition of pro-oxidant enzymes such as NADPH oxidase. Paraoxonase 2 (PON2) is also involved in the inhibition of NADPH oxidase activity. Therefore, we tested the hypothesis that D1R and D5R inhibit ROS production by increasing the expression of PON2, including those in membrane microdomains. METHODS AND RESULTS: PON2 colocalized with D1R and D5R in mouse renal proximal tubules (RPTs), human RPT (hRPT) cells, and HEK293 cells heterologously expressing human D1R (HEK-hD1R) or D5R (HEK-hD5R). Fenoldopam, an agonist for both D1R and D5R, increased PON2 co-immunoprecipitation with D1R and D5R in HEK-hD1R and HEK-hD5R cells, respectively. Silencing PON2 increased ROS production and NADPH oxidase activity, and impaired the inhibitory effect of fenoldopam. Fenoldopam increased PON2 protein in both lipid rafts (LRs) and non-LRs in HEK-hD1R cells, but only in non-LRs in HEK-hD5R and hRPT cells. Long-term (hrs) fenoldopam stimulation increased PON2 protein in a time-dependent manner in HEK-hD5R, but not in HEK-hD1R cells. Because the effects of fenoldopam on non-LR and total PON2 expressions were similar in HEK-hD5R and hRPT cells, additional studies were performed to determine the relationship between D5R and PON2. Renal PON2 protein was decreased in D5(-/-) mice. In hRPT cells, silencing D5R decreased PON2 expression and increased ROS production. CONCLUSIONS: We conclude that D1-like receptors inhibit ROS production by altering PON2 distribution in membrane microdomains in the short-term, and by increasing PON2 expression in the long-term.

Effects of chronic red wine consumption on the expression of vascular endothelial growth factor, angiopoietin 1, angiopoietin 2, and its receptors in rat erectile tissue.

Long-term consumption of red wine (RW) apparently confers some protection against cardiovascular diseases due to antiatherosclerotic properties of polyphenols and ethanol (EtOH). There is some evidence indicating that they do so by regulating angiogenesis, but the mechanism and the modulator factors involved are largely unknown. The aim of this study was to evaluate the effects of chronic ingestion of RW in vascular structure and in the pattern of expression of vascular growth factors in the rat corpus cavernosum. Male Wistar rats aged 6 mo were treated with RW or an equivalent EtOH solution, as the only liquid source for 6 mo. Expression of vascular endothelial growth factor (VEGF), angiopoietin 1 and angiopoietin 2, and their receptors (VEGFR1, VEGFR2, and Tie2) in cavernous tissue was assayed by immunofluorescence and Western blotting. A reduction of VEGF and VEGFR2 expression, respectively, in smooth muscle and endothelial cells was observed in RW-treated animals, which was balanced by an increase in angiopoietins/Tie2 expression. In EtOH rats, only a decrease in expression of the receptors VEGFR2 and Tie2 was observed. These results, taken together, suggest that antioxidants present in RW activate selected mechanisms for the maintenance of cavernous tissue vascularization. However, functional studies will be necessary to elucidate if RW is of benefit in the prevention of deleterious vascular events associated with ED.

Increased responsiveness to JNK1/2 mediates the enhanced H2O2-induced stimulation of Cl-/HCO3- exchanger activity in immortalized renal proximal tubular epithelial cells from the SHR.

We have previously demonstrated that exogenous H2O2 stimulates Cl(-)/HCO3(-) exchanger activity in immortalized renal proximal tubular epithelial (PTE) cells from both the Wistar-Kyoto (WKY) rat and the spontaneously hypertensive rat (SHR), this effect being more pronounced in SHR cells. The aim of the present study was to examine the mechanism of H2O2-induced stimulation of Cl(-)/HCO3(-) exchanger activity in WKY and SHR cells. It is now reported that the SHR PTE cells were endowed with an enhanced capacity to produce H2O2, comparatively with WKY cells and this was accompanied by a decreased expression of SOD2, SOD3, and catalase in SHR PTE cells. The stimulatory effect of H2O2 on the exchanger activity was blocked by SP600125 (JNK inhibitor), but not by U0126 (MEK1/2 inhibitor) or SB203580 (p38 inhibitor) in both cell lines. Basal JNK1 and JNK2 protein expression was higher in SHR PTE cells than in WKY PTE cells. H2O2 had no effect on p-JNK1/2 in WKY PTE cells over time. By contrast, H2O2 treatment resulted in a rapid and sustained increase in JNK1/2 phosphorylation in SHR PTE cells, which was completely abolished by apocynin. Treatment of SHR PTE cells with apocynin significantly decreased the H2O2-induced stimulation of Cl(-)/HCO3(-) exchanger activity. It is concluded that H2O2-induced stimulation of Cl(-)/HCO3(-) exchanger activity is regulated by JNK1/2, particularly by JNK2, in SHR PTE cells. The imbalance between oxidant and antioxidant mechanisms in SHR PTE cells enhances the response of JNK1/2 to H2O2, which contributes to their increased sensitivity to H2O2.

Caracterização de sorotipos em linhagens do gênero Salmonella isoladas de diferentes afecções em animais domésticos / Serotype characterization of Salmonella strains isolated from different affections in domestic animals

Foram caracterizados os sorotipos, o perfil de sensibilidade microbiana e os achados clínico-epidemiológicos em 53 linhagens do gênero Salmonella isoladas de 41 cães, nove equinos e três bovinos, acometidos por diferentes manifestações clínicas entre 1997 e 2007. Salmonella Typhimurium (45,3 por cento), Salmonella enterica (22,6 por cento), Salmonella Enteritidis (7,5 por cento), Salmonella enterica subsp enterica 4,5,12i (5,7 por cento), Salmonella Newport (5,7 por cento), Salmonella Dublin (3,8 por cento), Salmonella Agona (3,8 por cento), Salmonella Glostrup (3,8 por cento), Salmonella Saintpaul (1,8 por cento) foram os sorotipos encontrados. Ciprofloxacina (100,0 por cento), norfloxacina (100,0 por cento) e gentamicina (100,0 por cento) foram os antimicrobianos mais efetivos, enquanto a maior resistência das linhagens foi observada para ceftiofur (28,5 por cento) e florfenicol (7,0 por cento). As linhagens foram isoladas de animais com enterite, infecção do trato urinário, septicemia, piometra, pneumonia e conjuntivite. Ressalta-se para o predomínio do sorovar Typhimurium nas diferentes manifestações da salmonelose nos animais. Destaca-se, também, a identificação de sorotipos nos animais que também são observados em casos de salmonelose em humanos

The serotype characterization, antimicrobial susceptibility profile, and clinical-epidemiological findings were evaluated in 53 Salmonella spp. strains isolated from 41 dogs, nine horses and three cattle presenting different clinical manifestations between 1997 at 2007. Salmonella Typhimurium (45.3 percent), Salmonella enterica (22.6 percent), Salmonella Enteritidis (7.5 percent), Salmonella enterica subsp. enterica 4,5,12i (5.7 percent), Salmonella Newport (5.7 percent), Salmonella Dublin (3.8 percent), Salmonella Agona (3.8 percent), Salmonella Glostrup (3.8 percent), Salmonella Saintpaul (1.8 percent) were the more common serotypes. Ciprofloxacin (100.0 percent), norfloxacin (100.0 percent) and gentamicin (100.0 percent) were more effective drugs while resistance of isolates was observed to ceftiofur (28.5 percent) and florfenicol (7.0 percent). The strains were isolated from animals with enteritis, urinary tract infections, septicaemia, pyometra, pneumonia and conjuntivits. The results showed the high frequency of Salmonella Typhimurium serotype in different animals studied. The study highlighted also the presence of serotypes in our animals that also have been identified in humans with salmonellosis.

Comparison of inhibitors of superoxide generation in vascular smooth muscle cells.

BACKGROUND AND PURPOSE: We compared the dose-dependent reductions in cellular superoxide anion (O(2)(-)) by catalytic agents: superoxide dismutase (SOD), polyethylene glycol (PEG)-SOD and the nitroxide 4-hydroxy-2,2,6,6,-tetramethylpiperidine-1-oxyl (tempol) with uncharacterized antioxidants: 5,10,15,20-tetrakis (4-sulphonatophenyl) porphyrinate iron (III)(Fe-TTPS), (-)-cis-3,3',4',5,7-pentahydroxyflavane (2R,3R)-2-(3,4-dihydroxyphenyl)-3,4-dihydro-1(2H)-benzopyran-3,5,7-triol (-epicatechin), 2-phenyl-1,2-benzisoselenazol-3(2H)-one (ebselen) and N-acetyl-L-cysteine (NAC) with the spin trap nitroblue tetrazolium (NBT) and with the vitamins or their analogues: ascorbate, alpha-tocopherol and 6-hydroxy-2,5,7,8-tetramethylkroman-2-carboxy acid (trolox). EXPERIMENTAL APPROACH: O(2)(-) was generated in primary cultures of angiotensin II-stimulated preglomerular vascular smooth muscle cells from spontaneously hypertensive rats and detected by lucigenin-enhanced chemiluminescence. KEY RESULTS: SOD, PEG-SOD, NAC and tempol produced a similar maximum inhibition of O(2)(-) of 80-90%. -Epicatechin, NBT, ebselen and Fe-TTPS were significantly (P < 0.0125) less effective (50-70%), whereas trolox, alpha-tocopherol and ascorbate had little action even over 24 h of incubation (<31%). Effectiveness in disrupted and intact cells was similar for the permeable agents, PEG-SOD and tempol, but was enhanced for SOD. Generation of O(2)(-) was increased by NAC and NBT at low concentrations but reduced at high concentrations. CONCLUSIONS AND IMPLICATIONS: Maximum effectiveness against cellular production of O(2)(-) requires cell membrane permeability and catalytic action as exemplified by PEG-SOD or tempol. NAC and NBT have biphasic effects on O(2)(-) production. Vitamins C and E or analogues have low efficacy.