A peptide fraction from hardened common beans (Phaseolus vulgaris) induces endothelium-dependent antihypertensive and renal effects in rats

Beans reached the research spotlight as a source of bioactive compounds capable of modulating different functions. Recently, we reported antioxidant and oxidonitrergic effect of a low molecular weight peptide fraction (<3 kDa) from hardened bean (Phaseolus vulgaris) in vitro and ex vivo, which necessitate further in vivo assessments. This work aimed to evaluate the hypotensive effect and the involved physiological mechanisms of the hardened common bean peptide (Phaseolus vulgaris) in normotensive (Wistar) and hypertensive (SHR) animals. Bean flour was combined with a solution containing acetonitrile, water and formic acid (25: 24: 1). Protein extract (PV3) was fractioned (3 kDa membrane). We assessed PV3 effects on renal function and hemodynamics of wistar (WT-normotensive) and spontaneously hypertensive rats (SHR) and measured systemic arterial pressure and flow in aortic and renal beds. The potential endothelial and oxidonitrergic involvements were tested in isolated renal artery rings. As results, we found that PV3: I) decreased food consumption in SHR, increased water intake and urinary volume in WT, increased glomerular filtration rate in WT and SHR, caused natriuresis in SHR; II) caused NO- and endothelium-dependent vasorelaxation in renal artery rings; III) reduced arterial pressure and resistance in aortic and renal vascular beds; IV) caused antihypertensive effects in a dose-dependent manner. Current findings support PV3 as a source of bioactive peptides and raise the potential of composing nutraceutical formulations to treat renal and cardiovascular diseases.

SWATH proteomic analysis from the standard care versus celecoxib outcome trial identifies renal biomarkers are associated with early cardiovascular events amongst NSAID users

Background

Despite being one of the most commonly used and readily available drugs worldwide, we still do not understand why non-steroidal anti-inflammatory drugs (NSAIDs) increase cardiovascular risk. A proteomics approach may provide mechanistic insight into how COX-2 protects the cardiovascular system.

Purpose

To use SWATH proteomics to identify cardiovascular biomarkers in NSAID users who go onto have a cardiovascular event.

Methods

A case control study was designed using the Standard Care Versus Celecoxib Outcome Trial (SCOT) biobank (1). Serum samples from 228 NSAID users with osteoarthritis were analysed. From these, an exploratory analysis of 15 individuals who had a cardiovascular event within 6 months were compared to 213 individuals who did not. SWATH proteomics was used to identify biomarkers and findings were validated by immunoassay.

Results

Seventy-eight proteins were detected at significantly different levels in serum from participants who did or did not have an event within 6 months of enrolment. Of these the greatest increase in the event group was in levels of the renal dysfunction marker, cystatin C (Log Fold difference 1.4, p&lt;0.001). Validation using a renal biomarker immunoassay panel confirmed a higher level of cystatin C (Z-score 0.6 vs −0.04, p: 0.02) as well as a lower level of uromodulin (Z-score −0.5 vs 0.03, p: 0.036) in the event group. In agreement, mass spectrometry analysis identified a higher level of the cardio-renal biomarker asymmetric dimethylarginine (ADMA) in the event group (Z-score 0.4 vs −0.03, p: 0.07) (Figure 1).

Conclusion

Renal biomarkers are associated with early cardiovascular events amongst NSAID users in the SCOT cohort. Thus, changes in renal function should be investigated as a mechanistic or predictive factor in this population at elevated cardiovascular risk.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): British Heart Foundation

Dysregulation in erythrocyte dynamics caused by SARS-CoV-2 infection: possible role in shuffling the homeostatic puzzle during COVID-19

Introduction

The evolving COVID-19 pandemic became a hallmark in human history, not only by changing lifestyles, but also by enriching scientific knowledge on viral infection and its consequences.

Objective

Although the management of cardiorespiratory changes is pivotal to a favorable prognosis during severe clinical findings, dysregulation of other systems caused by SARS-CoV-2 infection may imbalance erythrocyte dynamics, such as a bidirectional positive feedback loop pathophysiology.

Method and Results

Recent evidence shows that SARS-CoV-2 is capable of affecting the genetics and dynamics of erythrocytes and this coexists with a non-homeostatic function of cardiovascular, respiratory and renal systems during COVID-19. In hypothesis, SARS-CoV-2-induced systematical alterations of erythrocytes dynamics would constitute a setpoint for COVID-19-related multiple organ failure syndrome and death.

Conclusion

The present review covers the most frequent erythrocyte-related non-homeostatic findings during COVID-19 capable of providing mechanistic clues of SARS-CoV-2-induced infection and inspiring therapeutic-oriented scientific evidence.

Galvanic effect of pyrite on arsenic release from arsenopyrite dissolution in oxygen-depleted and oxygen-saturated circumneutral solutions

Arsenopyrite (FeAsS), the most common arsenic-bearing mineral, is usually found associated with pyrite (FeS₂) in gold mining tailings. This work examined the galvanic effect of FeS₂ on As release from FeAsS oxidation in circumneutral media under oxygen-depleted and oxygen-saturated conditions. The oxidation experiments were conducted with a flow-through reactor in the absence of FeS₂ particles and in the presence of different contents of this sulfide. The results indicated that the permanent, physical contact between FeAsS and FeS₂ particles causes an increase in the accumulated As release, mainly under O₂-saturated conditions. At 30% wt. FeS₂, the increases relatively to FeS₂-free conditions were 82% and 117% in O₂-depleted and O₂-saturated solutions, respectively. At steady-state, the As release rates increased from (4.9 ± 0.5)× 10^-4 µmol m^-2 s^-1 (0% wt. FeS₂) to (1.1-1.9)× 10^-3 µmol m^-2 s^-1 (5-30% wt. FeS₂) under O₂-saturated conditions. Analysis of FeAsS samples after oxidation revealed oxidized particles partially or entirely covered by precipitates with different sizes, shapes and compositions (e.g., As-S-bearing ferrihydrite, elemental sulfur, and As-O phases). A fine (3-4 nm thick) amorphous layer of S-As-bearing ferric oxy-hydroxide was also identified on oxidized FeAsS, with Fe(III) and As(III) species.

COVID-19 and HIV/AIDS in a cohort study in Sao Paulo, Brazil: outcomes and disparities by race and schooling

Studies describing characteristics and outcomes of COVID-19 among people living with HIV are currently limited, lacking detailed evaluation of the interplay among demographics, HIV-related variables, and comorbidities on COVID-19 outcomes. This retrospective cohort study describes mortality rates overall and according to demographic characteristics and explores predictors of admission to intensive care unit and death among 255 persons living with HIV with severe acute respiratory syndrome and confirmed SARS-CoV-2 infection in the State of Sao Paulo, Brazil. We found that the overall mortality rate was 4.1/1,000 person-days, with a case-fatality of 34%. Higher rates occurred among older adults, Black/Mixed skin color/race patients, and those with lower schooling. In a multivariable analysis adjusted for age, sex, CD4 count, viral load and number of comorbidities, skin color/race, and schooling remained significantly associated with higher mortality. Although tenofovir use was more frequent among survivors in the univariable analysis, we failed to find a statistically significant association between tenofovir use and survival in the multivariable analysis. Our findings suggest that social vulnerabilities related to both HIV and COVID-19 significantly impact the risk of death, overtaking traditional risk factors such as age, sex, CD4 count, and comorbidities.

Mode of induction of platelet-derived extracellular vesicles is a critical determinant of their phenotype and function

Platelet-derived extracellular vesicles (PDEVs) are the most abundant amongst all types of EVs in the circulation. However, the mechanisms leading to PDEVs release, their role in coagulation and phenotypic composition are poorly understood. PDEVs from washed platelets were generated using different stimuli and were characterised using nanoparticle tracking analysis. Procoagulant properties were evaluated by fluorescence flow cytometry and calibrated automated thrombography. EVs from plasma were isolated and concentrated using a novel protocol involving a combination of size exclusion chromatography and differential centrifugation, which produces pure and concentrated EVs. Agonist stimulation enhanced PDEV release, but did not alter the average size of EVs compared to those produced by unstimulated platelets. Agonist stimulation led to lower negatively-charged phospholipid externalization in PDEVs, which was reflected in the lower procoagulant activity compared to those generated without agonist stimulation. Circulating EVs did not have externalized negatively-charged phospholipids. None of the 4 types of EVs presented tissue factor. The mechanism by which PDEV formation is induced is a critical determinant of its phenotype and function. Importantly, we have developed methods to obtain clean, concentrated and functional EVs derived from platelet-free plasma and washed platelets, which can be used to provide novel insight into their biological functions.

Mechanical Design and Modeling of a Manipulator Tool for a Compact Multiple-Tool Single Port Laparoscopic Robot Platform

Laparoendoscopic single-site surgery (LESS) has been shown to reduce the invasiveness of surgery by requiring only one incision to access the abdominal cavity. However, single-site surgery integrating with a compact robotic surgical platform remains as a unique challenge. To address this challenge, we have designed a comprehensive robotic surgery platform that consists of three 6-DOF manipulators and a laparoscope camera can all be inserted into the operation field through a single 18 mm cannula holding by one 4 degrees of freedom light-weight supporting frame. Each dexterous manipulator is 5+1 degree-of-freedom (DOF), serially inserted and removable, and remotely driven by 12 actuation tendons and is composed of rigid links joined by hybrid flexure hinges. This paper introduces the compact multiple-tool single port laparoscopic robot platform for the first time. Details of the mechanical design of the trocar and manipulator including joint design and tendon routing are presented. The forward and inverse kinematics of the manipulator are also discussed along with an analysis and simulation of the cooperative workspace of two manipulators. A preliminary dynamic model of the manipulator was also constructed to study the effect of tendon-sheath friction forces at various joint configurations. Future work will illustrate the existing supporting frame mechanism for posing tools and trocar.

Behavioral effects of Bj-PRO-7a, a proline-rich oligopeptide from Bothrops jararaca venom

The heptapeptide Bj-PRO-7a, isolated and identified from Bothrops jararaca (Bj) venom, produces antihypertensive and other cardiovascular effects that are independent on angiotensin converting enzyme inhibition, possibly relying on cholinergic muscarinic receptors subtype 1 (M1R). However, whether Bj-PRO-7a acts upon the central nervous system and modifies behavior is yet to be determined. Therefore, the aims of this study were: i) to assess the effects of acute administration of Bj-PRO-7a upon behavior; ii) to reveal mechanisms involved in the effects of Bj-PRO-7a upon locomotion/exploration, anxiety, and depression-like behaviors. For this purpose, adult male Wistar (WT, wild type) and spontaneous hypertensive rats (SHR) received intraperitoneal injections of vehicle (0.9% NaCl), diazepam (2 mg/kg), imipramine (15 mg/kg), Bj-PRO-7a (71, 213 or 426 nmol/kg), pirenzepine (852 nmol/kg), α-methyl-DL-tyrosine (200 mg/kg), or chlorpromazine (2 mg/kg), and underwent elevated plus maze, open field, and forced swimming tests. The heptapeptide promoted anxiolytic and antidepressant-like effects and increased locomotion/exploration. These effects of Bj-PRO-7a seem to be dependent on M1R activation and dopaminergic receptors and rely on catecholaminergic pathways.

Quenched phonon drag in silicon nanowires reveals significant effect in the bulk at room temperature

Existing theory and data cannot quantify the contribution of phonon drag to the Seebeck coefficient (S) in semiconductors at room temperature. We show that this is possible through comparative measurements between nanowires and the bulk. Phonon boundary scattering completely quenches phonon drag in silicon nanowires enabling quantification of its contribution to S in bulk silicon in the range 25-500 K. The contribution is surprisingly large (∼34%) at 300 K even at doping of ∼3 × 10(19) cm(-3). Our results contradict the notion that phonon drag is negligible in degenerate semiconductors at temperatures relevant for thermoelectric energy conversion. A revised theory of electron-phonon momentum exchange that accounts for a phonon mean free path spectrum agrees well with the data.

Gold nanoparticles functionalised with stable, fast water exchanging Gd3+ chelates as high relaxivity contrast agents for MRI

Gold nanoparticles functionalized with Gd(3+) chelates displaying fast water exchange, superb pH stability and inertness towards transmetalation with Zn(2+) have been prepared and characterized as a new high relaxivity (29 mM(-1) s(-1), 30 MHz, 25 °C) contrast agent potentially safe for in vivo MRI applications. The Lipari-Szabo treatment for internal rotation was used to evaluate the effect of linker flexibility on the relaxivity of the gold nanoparticles. The effect of fast water exchange on the relaxivity of gold nanoparticles functionalized with Gd(3+) chelates is also addressed in this communication.

Solid-state superionic stamping with silver iodide-silver metaphosphate glass

This paper demonstrates and analyzes the new use of the glassy solid electrolyte AgI-AgPO(3) for direct nanopatterning of thin silver films with feature resolutions of 30 nm. AgI-AgPO(3) has a high room temperature ionic conductivity with Ag( + ) as the mobile ion, leading to silver etch/patterning rates of up to 20 nm s( - 1) at an applied bias of 300 mV. The glass can be melt-processed at temperatures below 200 °C, providing a facile and economical pathway for creating large area stamps, including the 25 mm(2) stamps shown in this study. Further, the glass is sufficiently transparent to permit integration with existing tools such as aligners and imprint tools, enabling high overlay registration accuracy and facilitating insertion into multi-step fabrication recipes.

Direct metal nano-imprinting using an embossed solid electrolyte stamp

In this paper, we report direct patterning of metal nanostructures using an embossed solid electrochemical stamp. Microforming of solid superionic stamps using Si templates--analogous to polymer patterning in nano-imprint lithography--is explored. Silver sulfide (Ag₂S)--a superionic conductor with excellent microforming properties--is investigated as a candidate material. Important parameters of the superionic stamp, including mechanical behavior, material flow during forming and feature recovery after embossing, are studied. Excellent feature transferability during embossing as well as etching is observed. To illustrate the capability of this approach silver nano-antennas with gaps < 10 nm were successfully fabricated. The possibility for large area patterning with stamp diameters > 6 mm is also demonstrated. Embossing-based metal patterning allows fabrication beyond two-dimensional nanofabrication and several patterning schemes are reported.

Evidence for a role of AT(2) receptors at the CVLM in the cardiovascular changes induced by low-intensity physical activity in renovascular hypertensive rats

In the present study, we evaluated the involvement of the rennin-angiotensin system (RAS) in the control of the blood pressure (BP), baroreceptor-mediated bradycardia and the reactivity of caudal ventrolateral medulla (CVLM) neurons to Ang II and to AT(2) receptor antagonist in sedentary or trained renovascular hypertensive rats. Physical activity did not significantly change the baseline mean arterial pressure (MAP), heart rate (HR) or the sensitivity of the baroreflex bradycardia in normotensive Sham rats. However, in 2K1C hypertensive rats, physical activity induced a significant fall in baseline MAP and HR and produced an improvement of the baroreflex function (bradycardic component). The microinjections of Ang II into the CVLM produced similar decreases in MAP in all groups, Sham and 2K1C, sedentary and trained rats. The hypotensive effect of Ang II at the CVLM was blocked by previous microinjection of the AT(2) receptors antagonist, PD123319, in all groups of rats. Unexpectedly, microinjection of PD123319 at the CVLM produced a depressor effect in 2K1C sedentary that was attenuated in 2K1C trained rats. No significant changes in MAP were observed after PD123319 in Sham rats, sedentary or trained. These data showed that low-intensity physical activity is effective in lowering blood pressure and restoring the sensitivity of the baroreflex bradycardia, however these cardiovascular effects are not accompanied by changes in the responsiveness to Ang II at CVLM in normotensive or hypertensive, 2K1C rats. In addition, the blood pressure changes observed after AT(2) blockade in 2K1C rats suggest that hypertension may trigger an imbalance of AT(1)/AT(2) receptors at the CVLM that may be restored, at least in part, by low-intensity physical activity.

Association between CYP2E1 polymorphisms and susceptibility to prostate cancer

Several genetic alterations have been associated with sporadic prostate cancer (PCa). In this study, the association between RsaI and DraI polymorphisms of CYP2E1 and PCa risk was analysed in a case-control study of 227 individuals using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Regarding DraI polymorphisms, the DD genotype is over-represented in PCa cases when compared with the control group (odds ratio (OR) 2.12; 95% confidence interval (CI) 1.11-4.05; P=0.022). Regarding the RsaI polymorphism, no significant differences were found. The results of this study indicate that DraI polymorphisms of the CYP2E1 gene may be associated with a twofold increased risk for the development of PCa.

Anti-in?ammatory effect ofSolanum lycocarpum fruits

The croton oil-induced mouse ear oedema test, acetic acid-induced abdominal writhing, and carrageenan-induced peritonitis were used to study the anti-inflammatory effects of the crude ethanol extract and its alkaloid fraction from Solanum lycocarpum fruits. The alkaloid fraction induced a dose-dependent reduction in ear oedema formation and leukocyte migration, suggesting that S. lycocarpum fruits may contain steroidal alkaloids accounting for the anti-inflammatory effect of the crude ethanol extract.

Kinin receptors mediating the effect of bradykinin on gastric acid secretion

Kinins, and bradykinin in particular, can affect electrolyte transport in different segments of the intestine, thus being able to stimulate chloride secretion. Since the stomach is the main chloride secretory unit in the gastrointestinal tract, we have investigated the effect of bradykinin on acid secretion in the isolated frog (Rana catesbeiana) gastric mucosa. Bradykinin [2 x 10(-8) to 2 x 10(-6) M] and des-Arg9-bradykinin [2 x 10(-9) to 2 x 10(-7) M] were able to stimulate acid secretion in a dose-dependent manner. The bradykinin [2 x 10(-7) M] and des-Arg9-bradykinin (2 x 10(-8) M]-induced acid secretion was unaffected by Thi5,8,D-Phe7-bradykinin [2 x 10(-7) to 2 x 10(-5) M], a B2-kinin receptor antagonist. Interestingly, the B1-kinin receptor antagonist, des-Arg9-(Leu8)-bradykinin [2 x 10(-7) to 2 x 10(-5) M] blocked both bradykinin- and des-Arg9-bradykinin-stimulated acid secretion. Although the kininase I inhibitor, D-L-mercapto-methyl-3-guanidino-ethyl-propanoic acid [2 x 10(-6) and 2 x 10(-5) M] had no effect on des-Arg9-bradykinin-induced acid secretion, it inhibited the response to bradykinin. We conclude that bradykinin requires, at least in part, hydrolysis to des-Arg9-bradykinin to increase gastric acid secretion and that its effect is mediated by B1-kinin receptors.

A cross-sectional study of prevalence and etiology of signs and symptoms of temporomandibular disorders in high school and university students

The aim of this study was to evaluate the prevalence and need for treatment of temporomandibular disorders (TMD) in students living in Bauru, Brazil. The role of occlusal and emotional factors was also addressed. The presence and severity of TMD was determined by using a self-reported anamnestic questionnaire composed of 10 questions regarding common TMD symptoms. The symptoms were transposed into a severity classification according to the number and frequency of positive responses. Occlusal evaluation included an analysis of retruded contact position, intercuspal position, anterolateral guidance, and nonworking side contacts during mandibular movements. Palpation of the muscles and temporomandibular joints were performed to detect clinical signs of TMD. A chi square test was used to compare clinical and occlusal data with the presence and severity of TMD. A total of 0.65% of the subjects had severe TMD symptoms, 5.81% had moderate symptoms, and 34.84% had mild symptoms. Those with severe and moderate symptom levels were interpreted to be in need of treatment. Symptoms were found significantly more frequently in females than in males (P < .01). Self-reported emotional tension and parafunctional habits demonstrated strong associations with TMD (P < .01). Occlusion did not seem to influence the presence or severity of TMD. Based on these results, the efficacy of some traditional TMD treatments should be reconsidered, and reversible and conservative procedures should be the first choice for managing TMD patients.

A comparison of tensile bond strengths of resin-retained prostheses made using five alloys

This in vitro study evaluated the bond strength of metal frameworks cast using Ni-Cr, Ni-Cr-Be, Cu-Al, type IV gold, and noble metal ceramic alloy with and without tin electroplating. The castings were luted to human teeth using Panavia Ex resin. It was found that tin electroplating had a negative effect for the Cu-Al and type IV gold alloys and a positive effect for gold for metal ceramic restorations. The best results were obtained using the Ni-Cr alloy.

Stress response of yeast

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Structure and expression of the ABF1-regulated ribosomal protein S33 gene in Kluyveromyces

The abundant multifunctional protein ABF1 of Saccharomyces cerevisiae binds to the upstream region of several genes, including some ribosomal protein genes like the one encoding protein S33. Deletion of the ABF1-binding sequence lowers the transcription of these genes three- to more than ten-fold. We have isolated the S33 genes of two related yeast species, Kluyveromyces lactis and Kluyveromyces marxianus. Comparison of the nucleotide sequences of these S33 genes with their counterpart from S. cerevisiae shows a strong sequence similarity covering the whole of the coding regions. In contrast, little or no sequence similarity is found in the 5'-flanking regions of the three genes. Also the trailer regions differ considerably in both length and sequence from one species to another. An ABF1-binding site is present in the upstream region of the S33 gene of K. marxianus. Retardation analyses showed that this sequence is able to bind a protein present in Kluyveromyces cells with a molecular mass somewhat lower than that of S. cerevisiae ABF1. Functional analyses, using a beta-glucuronidase reporter system, showed that the ABF1-binding site is indeed involved in transcription activation of the K. marxianus S33 gene in Kluyveromyces cells. A S. cerevisiae ABF1-gene-specific probe showed only weak hybridization with Kluyveromyces DNA and Northern blots did not show a signal. These results indicate that S. cerevisiae and Kluyveromyces contain functionally related but structurally dissimilar ABF1-type proteins.

[Surface roughness of investment samples and their metal castings]

Three phosphate bonded investments and three calcium type were studied observing the influence of investment on the final cast surface roughness. Increased dilution also incremented roughness for the phosphate investments. Between the two types of investments there was only significant difference concerning two specific commercial brands, but there were differences in the same type of investment among these different brands.