Long-term memory in Staphylococcus aureus α-hemolysin ion channel kinetics.

The kinetics of an ion channel are classically understood as a random process. However, studies have shown that in complex ion channels, formed by multiple subunits, this process can be deterministic, presenting long-term memory. Staphylococcus aureus α-hemolysin (α-HL) is a toxin that acts as the major factor in Staphylococcus aureus virulence. α-HL is a water-soluble protein capable of forming ion channels into lipid bilayers, by insertion of an amphipathic  ß-barrel. Here, the α-HL was used as an experimental model to study memory in ion channel kinetics. We applied the approximate entropy (ApEn) approach to analyze randomness and the Detrended Fluctuation Analysis (DFA) to investigate the existence of long memory in α-HL channel kinetics. Single-channel currents were measured through experiments with α-HL channels incorporated in planar lipid bilayers. All experiments were carried out under the following conditions: 1 M NaCl solution, pH 4.5; transmembrane potential of + 40 mV and temperature 25 ± 1 °C. Single-channel currents were recorded in real-time in the memory of a microcomputer coupled to an A/D converter and a patch-clamp amplifier. The conductance value of the α-HL channels was 0.82 ± 0.0025 nS (n = 128). The DFA analysis showed that the kinetics of α-HL channels presents long-term memory ([Formula: see text] = 0.63 ± 0.04). The ApEn outcomes showed low complexity to dwell times when open (ApEno = 0.5514 ± 0.28) and closed (ApEnc = 0.1145 ± 0.08), corroborating the results of the DFA method.

From random point processes to hierarchical cavity master equations for stochastic dynamics of disordered systems in random graphs: Ising models and epidemics.

We start from the theory of random point processes to derive n-point coupled master equations describing the continuous dynamics of discrete variables in random graphs. These equations constitute a hierarchical set of approximations that generalize and improve the cavity master equation (CME), a recently obtained closure for the usual master equation representing the dynamics. Our derivation clarifies some of the hypotheses and approximations that originally led to the CME, considered now as the first order of a more general technique. We tested the scheme in the dynamics of three models defined over diluted graphs: the Ising ferromagnet, the Viana-Bray spin-glass, and the susceptible-infectious-susceptible model for epidemics. In the first two, the equations perform similarly to the best-known approaches in literature. In the latter, they outperform the well-known pair quenched mean-field approximation.

Kahweol, a natural diterpene from coffee, induces peripheral antinociception by endocannabinoid system activation.

Kahweol is a compound derived from coffee with reported antinociceptive effects. Based on the few reports that exist in the literature regarding the mechanisms involved in kahweol-induced peripheral antinociceptive action, this study proposed to investigate the contribution of the endocannabinoid system to the peripheral antinociception induced in rats by kahweol. Hyperalgesia was induced by intraplantar injection of prostaglandin E2(PGE2) and was measured with the paw pressure test. Kahweol and the drugs to test the cannabinoid system were administered locally into the right hind paw. The endocannabinoids were purified by open-bed chromatography on silica and measured by LC-MS. Kahweol (80 µg/paw) induced peripheral antinociception against PGE2-induced hyperalgesia. This effect was reversed by the intraplantar injection of the CB1 cannabinoid receptor antagonist AM251 (20, 40, and 80 µg/paw), but not by the CB2 cannabinoid receptor antagonist AM630 (100 µg/paw). Treatment with the endocannabinoid reuptake inhibitor VDM11 (2.5 µg/paw) intensified the peripheral antinociceptive effect induced by low-dose kahweol (40 µg/paw). The monoacylglycerol lipase (MAGL) inhibitor, JZL184 (4 µg/paw), and the dual MAGL/fatty acid amide hydrolase (FAAH) inhibitor, MAFP (0.5 µg/paw), potentiated the peripheral antinociceptive effect of low-dose kahweol. Furthermore, kahweol increased the levels of the endocannabinoid anandamide, but not of the other endocannabinoid 2-arachidonoylglycerol nor of anandamide-related N-acylethanolamines, in the plantar surface of the rat paw. Our results suggested that kahweol induced peripheral antinociception via anandamide release and activation of CB1 cannabinoid receptors and this compound could be used to develop new drugs for pain relief.

LONG-PULSED ND:YAG LASER TO TREAT TELANGIECTASIA OF THE NOSE: A COMPREHENSIVE 5-YEAR SINGLE CENTER STUDY.

Telangiectases of the nose are of esthetic concern and treatment is warranted. The study provides the results of 5 years of treatment of telangiectases of the nose region with the long-pulsed Nd:YAG 1,064 nm laser. A retrospective analysis was conducted in patients of Fitzpatrick skin type II-V. Exclusion criteria were patients with a previous history of treatment of the nose region, pregnant or lactating patients or patients with unrealistic expectations regarding the treatment risks, limitations and results. Standardized photographs were obtained before each session and at least 2 months after the last treatment session. A long-pulsed Nd:YAG 1,064 nm laser was used with a spot size of 2.5mm, fluence of 100 - 175 J/cm2, pulse duration of up to 135ms and repetition rate of 2-4 Hz. The follow-up ranged from 2 months to 5 years. The number of laser sessions varied from 1 to 5 monthly. Assessment was made by comparing pre-treatment and post-treatment photographs by two independent specialists and also by the patients' own assessment. All patients presented improvement of the vascular alterations. Evaluation of independent specialists as well as the evaluation of the patients themselves showed a high degree of satisfaction with the treatment. The treatment presented only few transitory side effects. Treatment of telangiectasia on the nose skin with the long-pulsed Nd:YAG 1,064 nm laser demonstrated to be safe and effective even in darker pigmented skin. The major limitation of this study is its retrospective nature.

A new SYBR Green real-time PCR to detect SARS-CoV-2.

Phylogenetic analysis has demonstrated that the etiologic agent of the 2020 pandemic outbreak is a betacoronavirus named SARS-CoV-2. For public health interventions, a diagnostic test with high sensitivity and specificity is required. The gold standard protocol for diagnosis by the Word Health Organization (WHO) is RT-PCR. To detect low viral loads and perform large-scale screening, a low-cost diagnostic test is necessary. Here, we developed a cost-effective test capable of detecting SARS-CoV-2. We validated an auxiliary protocol for molecular diagnosis with the SYBR Green RT-PCR methodology to successfully screen negative cases of SARS-CoV-2. Our results revealed a set of primers with high specificity and no homology with other viruses from the Coronovideae family or human respiratory tract pathogenic viruses, presenting with complementarity only for rhinoviruses/enteroviruses and Legionella spp. Optimization of the annealing temperature and polymerization time led to a high specificity in the PCR products. We have developed a more affordable and swift methodology for negative SARS-CoV-2 screening. This methodology can be applied on a large scale to soften panic and economic burden through guidance for isolation strategies.

Saccharomyces boulardii as therapeutic alternative in experimental giardiasis.

AIMS: The objective of this study was to evaluate the effect of treatment with the probiotic Saccharomyces boulardii with or without metronidazole in experimental giardiasis. METHODS AND RESULTS: The effect of treatment with S. boulardii with or without metronidazole on the intestinal mucosa, the antioxidant defence system and the parasitic load was determined in experimental giardiasis. Eight groups of animals with infection and/or treatment with the probiotic and/or drugs for 1 week after infection with Giardia lamblia were used. A reduction of approximately 90% in the parasitic load was observed in all the treated groups. Saccharomyces boulardii attenuated the damage caused by infection in the intestinal mucosa preserving its architecture and inhibiting the oxidative stress induced by parasite and metronidazole. CONCLUSIONS: Saccharomyces boulardii was effective alone or in combination with metronidazole in resolving already established G. lamblia infection. SIGNIFICANCE AND IMPACT OF THE STUDY: These results suggest the use of S. boulardii as an alternative treatment for giardiasis mainly in cases of resistance or intolerance to conventional treatment.

Kahweol, a natural diterpene from coffee, induces peripheral antinociception by endocannabinoid system activation

Kahweol is a compound derived from coffee with reported antinociceptive effects. Based on the few reports that exist in the literature regarding the mechanisms involved in kahweol-induced peripheral antinociceptive action, this study proposed to investigate the contribution of the endocannabinoid system to the peripheral antinociception induced in rats by kahweol. Hyperalgesia was induced by intraplantar injection of prostaglandin E2(PGE2) and was measured with the paw pressure test. Kahweol and the drugs to test the cannabinoid system were administered locally into the right hind paw. The endocannabinoids were purified by open-bed chromatography on silica and measured by LC-MS. Kahweol (80 µg/paw) induced peripheral antinociception against PGE2-induced hyperalgesia. This effect was reversed by the intraplantar injection of the CB1 cannabinoid receptor antagonist AM251 (20, 40, and 80 μg/paw), but not by the CB2 cannabinoid receptor antagonist AM630 (100 μg/paw). Treatment with the endocannabinoid reuptake inhibitor VDM11 (2.5 μg/paw) intensified the peripheral antinociceptive effect induced by low-dose kahweol (40 μg/paw). The monoacylglycerol lipase (MAGL) inhibitor, JZL184 (4 μg/paw), and the dual MAGL/fatty acid amide hydrolase (FAAH) inhibitor, MAFP (0.5 μg/paw), potentiated the peripheral antinociceptive effect of low-dose kahweol. Furthermore, kahweol increased the levels of the endocannabinoid anandamide, but not of the other endocannabinoid 2-arachidonoylglycerol nor of anandamide-related N-acylethanolamines, in the plantar surface of the rat paw. Our results suggested that kahweol induced peripheral antinociception via anandamide release and activation of CB1 cannabinoid receptors and this compound could be used to develop new drugs for pain relief.

Effects of dietary counseling on sodium restriction in patients with chronic kidney disease on hemodialysis: A randomized clinical trial.

Reducing dietary sodium has the potential to benefit patients with chronic kidney disease on hemodialysis (HD). This study was aimed to evaluate the effects of dietary counseling on sodium restriction and its relationship with clinical, dietary, and quality of life parameters in patients on HD treatment. This study was designed as a randomized clinical trial. The study included 87 patients on HD, divided into intervention (n = 47) and control (n = 40) groups. Anthropometric, clinical, sodium intake, and quality of life data were evaluated in both groups at four-time points: baseline (T0), 90 days (T3), 180 days (T6), and 365 days (T12). The intervention group received dietary counseling at the beginning and throughout the study. There were no between-group differences regarding anthropometric, clinical, and quality of life data at any of the time points. The mean age was 59 ± 14 years, and most of the patients were men (61%) and had hypertension (90%). Total sodium (g) and processed meat (mg sodium) intake significantly decreased in both groups [intervention: T0 = 3.5 (2.3-4.7); T12 = 2.0 (0.7-2.5); P <0.0001; control: T0 = 3 (1.5-4.9); T12 = 2.0 (0.8-3.3); P = 0.001; and intervention: T0 = 78 (25-196); T12 = 21 (0-78); P = 0.003; control: T0 = 97 (31-406); T12 = 44 (0-152); P = 0.004, respectively] . There was a significant decrease in the consumption of packaged seasonings (mg sodium) [T0 = 130 (0-854); T12 = 0 (0-0); P = 0.015] and instant noodles [T0 = 19 (0-91); T12 = 0 (0-0); P = 0.017] in the intervention group. Dietary counseling was effective in changing dietary habits. In both groups, there was a reduction in total sodium intake, which was greater in the intervention group. Moreover, a decrease in the intake of salty foods, such as packaged seasonings and instant noodles, was only observed in the intervention group.

Invasive Lactococcus lactis producing mycobacterial Hsp65 ameliorates intestinal inflammation in acute TNBS-induced colitis in mice by increasing the levels of the cytokine IL-10 and secretory IgA.

AIMS: To investigate the anti-inflammatory activity of an invasive and Hp65-producing strain Lactococcus lactis NCDO2118 FnBPA+ (pXYCYT:Hsp65) in acute 2,4,6-trinitrobenzene sulphonic acid (TNBS)-induced colitis in mice as an innovative therapeutic strategy against Crohn's disease (CD). METHODS AND RESULTS: The pXYCYT:Hsp65 plasmid was transformed into the L. lactis NCDO2118 FnBPA+ strain, resulting in the L. lactis NCDO2118 FnBPA+ (pXYCYT:Hsp65) strain. Then, the functionality of the strain was evaluated in vitro for Hsp65 production by Western blotting and for invasion into Caco-2 cells. The results demonstrated that the strain was able to produce Hsp65 and efficiently invade eukaryotic cells. Subsequently, in vivo, the anti-inflammatory capacity of the recombinant strain was evaluated in colitis induced with TNBS in BALB/c mice. Oral administration of the recombinant strain was able to attenuated the severity of colitis by mainly reducing IL-12 and IL-17 levels and increasing IL-10 and secretory immunoglobulin A levels. CONCLUSIONS: The L. lactis NCDO2118 FnBPA+ (pXYCYT:Hsp65) strain contributed to a reduction in inflammatory damage in experimental CD. SIGNIFICANCE AND IMPACT OF THE STUDY: This study, which used L. lactis for the production and delivery of Hsp65, has scientific relevance because it shows the efficacy of this new strategy based on therapeutic protein delivery into mammalian enterocytes.

Constraints on Light Dark Matter Particles Interacting with Electrons from DAMIC at SNOLAB.

We report direct-detection constraints on light dark matter particles interacting with electrons. The results are based on a method that exploits the extremely low levels of leakage current of the DAMIC detector at SNOLAB of 2-6×10^{-22} A cm^{-2}. We evaluate the charge distribution of pixels that collect <10e^{-} for contributions beyond the leakage current that may be attributed to dark matter interactions. Constraints are placed on so-far unexplored parameter space for dark matter masses between 0.6 and 100 MeV c^{-2}. We also present new constraints on hidden-photon dark matter with masses in the range 1.2-30 eV c^{-2}.

Hipoxemia real y espuria en un paciente con hiperleucocitosis extrema / Real and spurious hypoxemia in a patient with extreme hyperleukocytosis

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Características de carcaça e carne de novilhos Aberdeen Angus submetidos à castração cirúrgica ou imunológica / Carcass characteristics and meat of Aberdeen Angus steers submitted to surgical or immunological castration

Objetivou-se avaliar as características de carcaça e carne de novilhos Aberdeen Angus castrados cirurgicamente em duas idades ou imunocastrados com dois protocolos. Foram utilizados 48 bezerros, monitorados a partir do nascimento e desmamados, com idade e peso médio inicial de seis meses e de 160±16,54kg, respectivamente. Os animais foram distribuídos aleatoriamente nos seguintes tratamentos: castração cirúrgica ao nascer; castração cirúrgica ao desmame; imunocastração com três doses da vacina Bopriva® e imunocastração com quatro doses da vacina Bopriva®. O delineamento experimental utilizado foi o inteiramente ao acaso. Novilhos imunocastrados com três doses apresentaram maior quebra ao resfriamento e menor espessura de gordura ajustada para 100kg de carcaça fria que castrados cirurgicamente ao nascer (P<0,05). A imunocastração com três doses proporcionou incremento na participação de músculo, em relação às castrações cirúrgicas, mas reduziu a gordura em relação à castração cirúrgica ao nascimento (P<0,05). A relação músculo:osso foi superior nos imunocastrados com três doses em relação a castrados cirurgicamente no desmame (P<0,05). Apesar de variações na participação tecidual na carcaça, a castração imunológica mostrou-se viável em substituição à castração cirúrgica, não alterando os padrões qualitativos da carne.(AU)

The objective of this study was to evaluate the carcass and meat characteristics of Aberdeen Angus steers surgically castrated at two ages or immunocastrated with two protocols. Forty-eight calves we used, monitored from birth and weaned, with age and initial mean weight of six months and 160±16.54kg, respectively. The animals were randomly assigned to the following treatments: surgical castration at birth; surgical castration at weaning; immunocastration with three doses of the Bopriva ® vaccine and immunocastration with four doses of the Bopriva ® vaccine. The experimental design was completely randomized. Immunocastrated steers with three doses had a greater cooling break and lower fat thickness adjusted for 100kg of cold carcass than surgically castrated at birth (P< 0.05). Immunocastration with three doses provided an increase in muscle participation in relation to surgical castration but reduced fat in relation to surgical castration at birth (P< 0.05). The muscle:bone ratio was higher in the immunocastrated with three doses compared to surgically castrated at weaning (P< 0.05). Despite variations in tissue involvement in the carcass, the immunological castration proved to be viable to replace surgical castration, not changing the quality of the meat standards.(AU)

Mycobacterium marinum lymphocutaneous infection.

Mycobacterium marinum is a nontuberculous mycobacteria with worldwide distribution that lives in fresh or salt water and is responsible for infections in fish, and sometimes in humans. Human disease consists mainly of cutaneous nodules, but deep structure involvement may also occur. Diagnosis of M. marinum infection remains a challenge, with a considerable time delay between onset of symptoms and diagnosis. We present a 33-year-old man with no immunosuppressive history who was seen in our department with skin nodules over his hand and forearm, distributed in a sporotrichoid pattern. His hobbies included maintaining an aquarium of tropical fish. Histological examination of the patient's skin biopsy was compatible with the diagnosis of mycobacterial infection, and the Ziehl-Neelsen staining revealed acid-fast bacilli. Molecular techniques confirmed the suspicion of M. marinum infection. A necropsy was performed on one of the patient's fish, more specifically, a Poecilia reticulata, and resulted in identification of M. marinum from its gut. The patient was treated with clarithromycin, ethambutol, and rifampicin for 9 months, with clearance of infection.

Late Cytomegalovirus Infection in Kidney Transplant Recipients after a Six-Month Prevention Protocol.

BACKGROUND: Despite a reduction in the incidence of cytomegalovirus (CMV) infections after kidney transplantation, less is known about late CMV infection in kidney transplant recipients. OBJECTIVE: To assess incidence of CMV infection in a cohort of patients under a high surveillance CMV prevention protocol and identify factors associated with late CMV infection. METHODS: Analysis of a consecutive cohort of 181 kidney allograft recipients between January 2012 and Aug 2015. CMV prevention-protocol consisted of 6-month universal prophylaxis and pre-emptive therapy for high-risk group (D+/R- or patients submitted to lymphocyte-depleting agent for induction or rejection treatment) and pre-emptive therapy for standard-risk group (D±/R+). Stopping valganciclovir was followed by CMV screening in the next two appointments. RESULTS: CMV infection was identified in 73 of 181 patients; the rate in high-risk group and standard-risk group was similar (p=0.443). However, in the latter group, the infection occurred mostly in the first 6 months. Late CMV infection occurred in 25 of 181 patients (5 of standard-risk group and 20 of high-risk group), after a median (IQR) of 253 (230.3-312.3) days after transplantation and 55 (41-89.5) days after the protocol period. Screening for CMV after valganciclovir discontinuation revealed 56% of late CMV infections. In high-risk group, D+/R- was associated with late CMV infection (HR 2.7, p=0.039) and in standard-risk group; lower age was associated with late CMV infection (HR 0.89, p=0.02). CONCLUSION: The incidence of CMV infection was similar to that reported in the literature. In high-risk patients, antigenemia surveillance during prophylaxis did not appear to reduce late CMV infections. Antigenemia screening after valganciclovir had limited results in the diagnosis of late CMV infection. D+/R- was associated to late CMV infection in high-risk group. Lower age appeared to influence late CMV infection in standard-risk group.

Notch signaling in human iPS-derived neuronal progenitor lines from Focal Cortical Dysplasia patients.

Focal Cortical Dysplasia (FCD), a common type of Malformations of cortical development, may result from an early disturbance in the migration and final arrangement of the cortical architecture of immature neurons. FCD type II is now known to be due to a post-zygotic somatic mutation that involves the mTOR and AKT pathways. The aim of the present study was to investigate the possible differences in neurogenesis and neurodifferentiation of iPSCs (induced pluripotent stem cells) from fibroblasts of individuals affected by FCD type II (2) and normal individuals (2). iPSCs were generated from skin fibroblasts of FCD individuals and healthy individuals. The reprogramming was done through the fibroblasts exposure to viral vectors containing the OCT4, KLF4, SOX2, and c-MYC genes and the clones were characterized by immunohistochemistry. iPSCs were neurodifferentiated and analyzed at the 14th, 22nd and 35th days. We also analyzed the cerebral cortex tissue, fibroblasts and iPSCs cells from the individuals. Through qRT-PCR, the expression of 4 genes involved in Notch signaling process were quantified. In general, individuals with dysplasia presented increase and decrease in the relative quantification in the most genes analyzed compared to control individuals in all processes and study groups. We suggest that, during embryonic neurogenesis, the neural precursor cells of FCD type II individuals present increase and decrease in gene expression in the Notch signaling pathway causing cortical formation disorders and can be seen as a candidate for the developmental changes observed in the cerebral cortex of individuals with FCD type II. This altered gene expression may be related to brain formation with dysplasia.

Dietary Patterns in Secondary Prevention of Heart Failure: A Systematic Review.

BACKGROUND: Diet is an important factor in secondary prevention of heart failure (HF) but there is still no consensus as to which dietary model should be adopted by this population. This systematic review aims to clarify the relationship between dietary patterns and secondary prevention in HF. METHODS: We searched the Medline, Embase and Cochrane databases for studies with different dietary patterns and outcomes of secondary prevention in HF. No limitation was used in the search. RESULTS: 1119 articles were identified, 12 met the inclusion criteria. Studies with Dietary Approaches to Stop Hypertension (DASH), Mediterranean, Hyperproteic and Low-carb diets were found. The DASH pattern showed improvement in cardiac function, functional capacity, blood pressure, oxidative stress and mortality. The Mediterranean diet had a correlation with inflammation, quality of life and cardiac function but just on cross-sectional studies. Regarding the Hyperproteic and Low-carb diets only one study was found with each pattern and both were able to improve functional capacity in patients with HF. CONCLUSIONS: DASH pattern may have benefits in the secondary prevention of HF. The Mediterranean diet demonstrated positive correlation with factors of secondary prevention of HF but need more RCTs and cohort studies to confirm these effects. In addition, the Hyperproteic and Low-carb diets, despite the lack of studies, also demonstrated positive effects on the functional capacity in patients with HF.

Aggressive fluid and sodium restriction in decompensated heart failure with preserved ejection fraction: Results from a randomized clinical trial.

OBJECTIVES: Sodium and fluid restriction is commonly prescribed for heart failure patients. However, its role in the treatment of heart failure with preserved ejection fraction (HFpEF) remains unclear. The aim of this study was to compare the effect of a diet with sodium and fluid restriction with an unrestricted diet in patients admitted for decompensated HFpEF. METHODS: Patients were randomized to a diet with sodium (0.8 g/d) and fluid (800 mL/d) restriction (intervention group [IG]) or an unrestricted diet (control group [CG]) and followed for 7 d or hospital discharge. The primary outcome was weight loss. Secondary outcomes included clinical stability, perception of thirst, neurohormonal activation, nutrient intake, readmission, and mortality rate after 30 d. RESULTS: Fifty-three patients were included (30, IG; 23, CG). The mean ejection fraction was 62% ± 8% for IG and 60% ± 7% for CG (P = 0.44). Weight loss was similar in both groups, being 1.6 ± 2.2 kg in the IG and 1.8 ± 2.1 kg in CG (P = 0.49) as well as the reduction in the congestion score (IG = 3.4 ± 3.5; CG = 3.8 ± 3.4; P = 0.70). The daily perception of thirst was higher in the IG (P = 0.03). Lower energy consumption was seen in the IG (P <0.001). No significant between-group differences at 30 d were found. CONCLUSIONS: Aggressive sodium and fluid restriction does not provide symptomatic or prognosis benefits, but does produce greater perception of thirst, may impair the patient's food intake, and does not seem to have an important neurohormonal effect in patients admitted for decompensated HFpEF.