ABSTRACT
OBJECTIVE/BACKGROUND: To describe and characterize insomnia symptoms and nightmare profiles in Portugal during the first six weeks of a national lockdown due to COVID-19. PATIENTS/METHODS: An open cohort study was conducted to collect information of the general population during the first wave of SARS-CoV-2/COVID-19 pandemic in Portugal. We analyzed data from 5011 participants (≥16 years) who answered a weekly questionnaire about their well-being. Two questions about the frequency of insomnia and nightmares about COVID-19 were consecutively applied during six weeks (March-May 2020). Latent class analysis was conducted and different insomnia and nightmare profiles were identified. Associations between individual characteristics and both profiles were estimated using odds ratios (ORs) and 95% confidence intervals (CI). RESULTS: Five insomnia (No insomnia, Stable-mild, Decreasing-moderate, Stable-severe, Increasing-severe) and three nightmares profiles (Stable-mild, Stable-moderate, Stable-severe) were identified. Being female, younger, perceiving their income as insufficient and feelings of fear towards COVID-19 were associated with higher odds of insomnia (Women: OR = 6.98 95%CI: 4.18-11.64; ≥60 years: OR = 0.30 95%CI: 0.18-0.53; Insufficient income: adjusted OR (aOR) = 8.413 95%CI: 3.93-16.84; Often presenting fear of being infected with SARS-CoV-2 infection: aOR = 9.13 95%CI: 6.36-13.11), and nightmares (Women: OR = 2.60 95%CI: 1.74-3.86; ≥60 years: OR = 0.45 95%CI: 0.28-0.74; Insufficient income: aOR = 2.60 95%CI: 1.20-5.20; Often/almost always presenting fear of being infected with SARS-CoV-2 infection: aOR = 6.62 95%CI: 5.01-8.74). Having a diagnosis of SARS-CoV-2 virus infection was associated with worse patterns of nightmares about the pandemic. CONCLUSIONS: Social and psychological individual factors are important characteristics to consider in the development of therapeutic strategies to support people with sleep problems during the COVID-19 pandemic.
Subject(s)
COVID-19 , Sleep Initiation and Maintenance Disorders , COVID-19/epidemiology , Cohort Studies , Communicable Disease Control , Dreams , Female , Humans , Pandemics , Portugal/epidemiology , SARS-CoV-2 , Sleep Initiation and Maintenance Disorders/epidemiologyABSTRACT
Objective. Recent technological advances are revealing the complex physiology of the axon and challenging long-standing assumptions. Namely, while most action potential (AP) initiation occurs at the axon initial segment in central nervous system neurons, initiation in distal parts of the axon has been reported to occur in both physiological and pathological conditions. The functional role of these ectopic APs, if exists, is still not clear, nor its impact on network activity dynamics.Approach. Using an electrophysiology platform specifically designed for assessing axonal conduction we show here for the first time regular and effective bidirectional axonal conduction in hippocampal and dorsal root ganglia cultures. We investigate and characterize this bidirectional propagation both in physiological conditions and after distal axotomy.Main results.A significant fraction of APs are not coming from the canonical synapse-dendrite-soma signal flow, but instead from signals originating at the distal axon. Importantly, antidromic APs may carry information and can have a functional impact on the neuron, as they consistently depolarize the soma. Thus, plasticity or gene transduction mechanisms triggered by soma depolarization can also be affected by these antidromic APs. Conduction velocity is asymmetrical, with antidromic conduction being slower than orthodromic.Significance.Altogether these findings have important implications for the study of neuronal functionin vitro, reshaping our understanding on how information flows in neuronal cultures.
Subject(s)
Axons , Neurons , Action Potentials/physiology , Axons/physiology , Ganglia, Spinal , Synapses/physiologyABSTRACT
The incorporation of thiourethane prepolymer (TU) into either the organic phase or as a surface treatment for filler particles in composites reduces polymerization stress and improves fracture toughness. The aim of this study was to gain insight into the influence of the inclusion of thiourethanes on the resulting network of methacrylate-based materials polymerized via free-radical mechanisms. Dynamic mechanical analysis was used to elucidate network parameters and potential stress relaxation behavior of these networks. TU oligomers were synthesized using a combination of trimethylol-tris-3-mercaptopropionate and dicyclohexylmethane 4,4'-diisocyanate and added into composite formulations at 20 wt% replacing part of the organic matrix and/or as TU-silanes used to functionalize filler particles (TU-matrix, TU-Sil or TU-matrix/sil). Materials not containing any form of TU were used as the control (in those cases, 3-(trimethoxysilyl)propyl methacrylate was used as the silane agent). Filler was added at 50 wt%. Degree of conversion was evaluated by near-IR spectroscopy, mechanical properties by 3-point bending and rotational rheometry. Dynamic mechanical analysis was used to obtain network parameters (glass transition temperature (Tg), storage modulus, cross-link density, and breadth of tan delta a proxy for network homogeneity - temperature sweep experiments) and to evaluate the potential for network relaxation (stress relaxation). TU-containing formulations showed 10% higher DC than the control. The time to reach storage/loss modulus crossover in the rheometer experiments was significantly longer for TU-matrix and TU-matrix/sil in comparison with the control (21.6, 27.9, and 5.1 s, respectively). TU-matrix and TU-matrix/sil presented significant lower Tg than the control (151.5, 153.8, and 161.3 °C, respectively). There were no statistical differences among the groups in terms of shear modulus, cross-link density, breadth of tan delta, flexural strength/modulus, and toughness. For at least one group (TU-matrix/sil), the relaxation time was four times faster than for the control at 105 °C. The addition of TU additives into dental polymers resulted in a stark reduction in the stress relaxation time. This behavior, in tandem with the network characterization and mechanical properties seems to indicate the TU networks undergo a variety of reversible associative and dissociative chemical reactions which facilitate enhanced stress relief.
Subject(s)
Carbamates/chemistry , Methacrylates/chemistry , Sulfhydryl Compounds/chemistry , Glass/chemistry , Stress, Mechanical , TemperatureABSTRACT
OBJECTIVES: Thio-urethane oligomeric additives have been shown to improve the mechanical properties of dental composites and resin cements. To try to harness those same properties in dental adhesives, in this study, these oligomers (TU) were added to the matrix and/or as filler functionalization of experimental adhesives, and the effects on conversion and mechanical properties were analyzed. METHODS: BisGMA and HEMA (60/40 wt%) were used as the monomer matrix, made polymerizable by the addition of 0.2 wt% 2,2-dimethoxy-2- phenylacetophenone. 2,6-di-tert-butyl-4-methylphenol was added at 0.5 wt% as the inhibitor. This material was used as the unfilled control (BH). TU oligomers were added at 20 wt % to the matrix (BH+20%TU, unfilled) and/or used as filler functionalization (TF, 10 wt%). Fillers functionalized with methacrylate (MF, 10 wt%) served as the control. The experimental adhesives groups containing fillers were: BH+10%MF; BH+10%TF; BH+20%TU+10%MF; BH+20%TU+10%TF. Flexural properties were tested in three-point bending (wet and dry). Polymerization kinetics was followed in real-time in near-IR. Water Sorption/Solubility (WS/SL, ISO 4049) and Viscosity (rotational rheometry) were also evaluated. For Microtensile bond strength 40 vol% ethanol was added to adhesives, which was applied onto sound dentin from third human molars. The data were analyzed with one-way ANOVA and Tukey post-hoc test, and test t for the comparison between storage time of the microtensile bond strength test (alpha = 0.05). RESULTS: There was no significant difference between groups when yield strength (YS) and flexural modulus (FM) were evaluated in dry conditions. After water storage, all the groups containing TU in the matrix showed statistically lower YS/FM values. This was true in spite of the statistically higher conversion for those same groups. The maximum rate of polymerization (Rpmax) was higher for BH+10%TF and no significant difference was found for the groups BH and BH+10% MF. The lowest Rpmax values were found for BH+20%TU+10%TF and BH+20%TU. BH+20%TU+10%TF showed the highest viscosity values followed by BH+20%TU+10%MF and BH+20%TU, with statistically significant difference between them. For the microtensile bond strength test at 24h (p = 0.13) and 6 months (p = 0.11) and WS/SL (p > 0.05), no significant difference was found among groups. The storage time (24 h and 6 months) did not affect the microtensile bond strength results. CONCLUSION: In spite of improving the conversion, the addition of TU in the matrix reduced the mechanical properties of the adhesives tested after water storage. This did not affect the bond strength at 24 h or 6 months.
ABSTRACT
The composition of cerebrospinal and brain interstitial fluids is ensured by barriers between the blood and the brain parenchyma (the blood-brain barrier) and between the blood and the cerebrospinal fluid (the blood-cerebrospinal fluid barrier). Barrier function results from the combination of tight junctions between cells that impair solute flux via the paracellular pathway, cell membrane transporters that enable selective transcellular solute passage, and intracellular metabolizing enzymes that transform molecules in transit. Collectively, they comprise a chemical surveillance system, essential to protect the brain from toxicants, microorganisms, and other harmful compounds. Conversely, this chemical surveillance system compromises the brain delivery of many pharmacologic agents against brain cancer and brain metastasis, neurodegenerative diseases, and brain infections. Despite their importance, the mechanisms underlying the regulation of the components of this chemical surveillance system in response to alterations in the composition of blood and brain fluids are still poorly understood. We propose that odorant receptors, vomeronasal receptors and taste receptors, recently identified at brain barriers might be upstream components of this surveillance system. These chemosensory receptors are strategically placed to monitor the composition of blood, cerebrospinal and brain interstitial fluids. Upon ligand-binding, they may deploy the action of transporters and detoxifying enzymes or other unprecedented functions in brain barrier cells, to cope with alterations in the composition of blood and brain cerebrospinal and interstitial fluids, working as guardians of the central nervous system.
Subject(s)
Blood-Brain Barrier/metabolism , Brain/metabolism , Cerebrospinal Fluid/metabolism , Choroid Plexus/metabolism , Animals , Humans , Neurons/metabolism , Tight Junctions/physiologyABSTRACT
The aim of this study was to evaluate the influence of different concentrations of hydrofluoric acid (HF) associated with varied etching times on the microshear bond strength (µSBS) of a resin cement to a lithium disilicate glass ceramic. Two hundred seventy-five ceramic blocks (IPS e.max Press [EMX], Ivoclar Vivadent), measuring 8 mm × 3 mm thickness, were randomly distributed into five groups according to the HF concentrations (n=50): 1%, 2.5%, 5%, 7.5%, and 10%. Further random distribution into subgroups was performed according to the following etching times (n=10): 20, 40, 60, 120, and 20 + 20 seconds. After etching, all blocks were treated with a silane coupling agent followed by a thin layer of an unfilled resin. Three resin cement cylinders (∅=1 mm) were made on each EMX surface, which was then stored in deionized water at 37°C for 24 hours before testing. The µSBS was in a universal testing machine at a crosshead speed of 1 mm/min until failure. Data were submitted to two-way analysis of variance, and multiple comparisons were performed using the Tukey post hoc test (α=0.05). One representative EMX sample was etched according to the description of each subgroup and evaluated using scanning electron microscopy for surface characterization. The HF concentrations of 5%, 7.5%, and 10% provided significantly higher µSBS values than 1% and 2.5% (p<0.05), regardless of the etching times. For 1% and 2.5% HF, the etching times from 40 to 120 seconds increased the µSBS values compared with 20 seconds (p<0.05), but etching periods did not differ within the 5%, 7.5%, and 10% HF groups (p>0.05). The effect of re-etching was more evident for 1% and 2.5% HF (p<0.05). Different HF concentrations/etching times directly influenced the bond strength and surface morphology of EMX.
Subject(s)
Ceramics/therapeutic use , Dental Bonding/methods , Dental Etching/methods , Dental Porcelain/therapeutic use , Hydrofluoric Acid/therapeutic use , Dental Stress Analysis , Hydrofluoric Acid/administration & dosage , In Vitro Techniques , Shear StrengthABSTRACT
The choroid plexus (CP) epithelium is a unique structure in the brain that forms an interface between the peripheral blood on the basal side and the cerebrospinal fluid (CSF) on the apical side. It is a relevant source of many polypeptides secreted to the CSF with neuroprotective functions and also participates in the elimination and detoxification of brain metabolites, such as ß-amyloid (Aß) removal from the CSF through transporter-mediated influx. The CP is also a target tissue for sex hormones (SHs) that have recognised neuroprotective effects against a variety of insults, including Aß toxicity and oxidative stress in the central nervous system. The present study aimed to understand how SHs modulate Aß-induced oxidative stress in a CP cell line (Z310 cell line) by analysing the effects of Aß1-42 on oxidative stress, mitochondrial function and apoptosis, as well as by assessing how 17ß-oestradiol (E2 ) and 5α-dihydrotestosterone (DHT) modulated these effects and the cellular uptake of Aß1-42 by CP cells. Our findings show that E2 and DHT treatment reduce Aß1-42 -induced oxidative stress and the internalisation of Aß1-42 by CP epithelial cells, highlighting the importance of considering the background of SHs and therefore sex-related differences in Aß metabolism and clearance by CP cells.
Subject(s)
Amyloid beta-Peptides/metabolism , Choroid Plexus/metabolism , Gonadal Steroid Hormones/metabolism , Oxidative Stress , Peptide Fragments/metabolism , 5-alpha-Dihydroprogesterone/metabolism , Amyloid beta-Peptides/toxicity , Animals , Apoptosis , Cell Line , Choroid Plexus/drug effects , Electron Transport Complex IV/metabolism , Estradiol/metabolism , Neuroprotective Agents , Peptide Fragments/toxicity , Prealbumin/metabolism , Rats, Wistar , Reactive Oxygen Species , Receptors, Estrogen/metabolismABSTRACT
The purpose of this study was to evaluate the influence of various concentrations of hydrofluoric acid (HF) on the surface/interface morphology and µ-shear bond strength (µSBS) between IPS Empress Esthetic (EST) (Ivoclar Vivadent) and IPS e.max Press (EMX) (Ivoclar Vivadent) ceramics and resin cement. Ceramic blocks were divided into 12 groups for each kind of ceramic. Six different HF concentrations were evaluated: 1%, 2.5%, 5%, 7.5%, 10%, and 15%. All groups were silanated after etching, and half of the specimens within each group received a thin layer of unfilled resin (UR). Three resin cement cylinders were prepared on each ceramic block for µSBS testing. The specimens were stored in distilled water at 37°C for 24 hours. The µSBS test was carried out in a universal testing machine at a crosshead speed of 0.5 mm/min until fracture. The data were submitted to three-way analysis of variance and multiple comparisons were performed using the Tukey post hoc test (p<0.05). The etched surfaces and bonded interfaces were evaluated using scanning electron microscopy. µSBS means (MPa) for 1%, 2.5%, 5%, 7.5%, 10%, and 15% HF concentrations were, respectively, 25.2, 27.2, 30.1, 31.4, 33.3, and 31.8. µSBS means with or without UR application measured 32.24 and 27.4, respectively; EST and EMX measured 29.8 and 29.9, respectively. For the HF concentrations, 10% and 15% showed higher µSBS means than did 1% and 2.5% (p<0.05); 7.5% was higher than 1% (p<0.05); and no statistical differences were found among the other concentrations (p>0.05). When evaluating UR, µSBS mean was significantly higher and better infiltration was observed on the etched surfaces. No statistical difference was found between the ceramics. The HF concentration and UR influenced the bond strength and surface/interface morphology.
Subject(s)
Ceramics , Dental Bonding , Hydrofluoric Acid , Resin Cements , Acrylic Resins , Ceramics/chemistry , Composite Resins , Dental Porcelain , Dental Stress Analysis , Hydrofluoric Acid/chemistry , Materials Testing , Microscopy, Electron, Scanning , Polyurethanes , Resin Cements/chemistryABSTRACT
SUMMARY Objectives : The aim of this present study was to investigate the effect of two surface treatments, fatigue and thermocycling, on the microtensile bond strength of a newly introduced lithium disilicate glass ceramic (IPS e.max Press, Ivoclar Vivadent) and a dual-cured resin cement. Methods : A total of 18 ceramic blocks (10 mm long × 7 mm wide × 3.0 mm thick) were fabricated and divided into six groups (n=3): groups 1, 2, and 3-air particle abraded for five seconds with 50-µm aluminum oxide particles; groups 4, 5, and 6-acid etched with 10% hydrofluoric acid for 20 seconds. A silane coupling agent was applied onto all specimens and allowed to dry for five seconds, and the ceramic blocks were bonded to a block of composite Tetric N-Ceram (Ivoclar Vivadent) with RelyX ARC (3M ESPE) resin cement and placed under a 500-g static load for two minutes. The cement excess was removed with a disposable microbrush, and four periods of light activation for 40 seconds each were performed at right angles using an LED curing unit (UltraLume LED 5, Ultradent) with a final 40 second light exposure from the top surface. All of the specimens were stored in distilled water at 37°C for 24 hours. Groups 2 and 5 were submitted to 3,000 thermal cycles between 5°C and 55°C, and groups 3 and 6 were submitted to a fatigue test of 100,000 cycles at 2 Hz. Specimens were sectioned perpendicular to the bonding area to obtain beams with a cross-sectional area of 1 mm(2) (30 beams per group) and submitted to a microtensile bond strength test in a testing machine (EZ Test) at a crosshead speed of 0.5 mm/min. Data were submitted to analysis of variance and Tukey post hoc test (p≤0.05). Results : The microtensile bond strength values (MPa) were 26.9 ± 6.9, 22.2 ± 7.8, and 21.2 ± 9.1 for groups 1-3 and 35.0 ± 9.6, 24.3 ± 8.9, and 23.9 ± 6.3 for groups 4-6. For the control group, fatigue testing and thermocycling produced a predominance of adhesive failures. Fatigue and thermocycling significantly decreased the microtensile bond strength for both ceramic surface treatments when compared with the control groups. Etching with 10% hydrofluoric acid significantly increased the microtensile bond strength for the control group.
Subject(s)
Ceramics/chemistry , Dental Bonding , Dental Porcelain/chemistry , Resin Cements/chemistry , Acid Etching, Dental/methods , Adhesiveness , Aluminum Oxide/chemistry , Bisphenol A-Glycidyl Methacrylate/chemistry , Composite Resins/chemistry , Curing Lights, Dental , Dental Etching/methods , Dental Stress Analysis/instrumentation , Humans , Hydrofluoric Acid/chemistry , Materials Testing , Microscopy, Electron, Scanning , Polyethylene Glycols/chemistry , Polymethacrylic Acids/chemistry , Radiation Dosage , Self-Curing of Dental Resins , Silanes/chemistry , Stress, Mechanical , Surface Properties , Temperature , Tensile Strength , Time Factors , Water/chemistryABSTRACT
AIM: The aim of this paper was to evaluate the influence of modulated photoactivation methods and volume of composite on Knoop hardness (KHN) and push-out bond strength (PBS) of Filtek Z350 to root dentin. METHODS: Three volumes (small, medium and large) of composite were bulk inserted in cavities prepared in 90 premolars. The specimens were photoactivated with continuous light, pulse-delay, or soft-start methods and submitted to PBS and KHN tests. The failure pattern was evaluated in stereomicroscope after the bond strength test. The data were submitted to two-way ANOVA and Tukey's test (P<0.05). RESULTS: Modulated photoactivation methods showed a higher PBS than continuous method (P<0.05). Medium volume of composite showed higher PBS than small and large volumes when photoactivated with continuous method (P<0.05). Pulse-delay significantly increased KHN for medium and large volumes in comparison to continuous method (P<0.05). Medium volume of composite showed KHN significantly higher than small and large volumes (P<0.05). CONCLUSION: The volume of composite influenced the PBS and KHN of resin composites. Pulse-delay showed the highest bond strength to dentin, as well KHN similar to the conventional method. The analysis of the failure pattern showed predominance of adhesive failure.
Subject(s)
Composite Resins , Dental Bonding , Dental Stress Analysis , Hardness Tests , Materials Testing , Humans , In Vitro TechniquesABSTRACT
BACKGROUND: Evidence suggests that Candida can be sexually transmitted; however, the contribution of sexual transmission to the pathogenesis of genital candidosis needs further elucidation. OBJECTIVE: The aim was to evaluate genital candidosis and its transmissibility in heterosexual couples. METHODS: Heterosexual couples were recruited among attendees of an Sexually Transmitted Diseases clinic. Specimens for yeast culture were collected from the glans penis and inner preputial layer using direct impression on CHROMagar Candida medium; vaginal exudates were collected using a cotton swab with subsequent inoculation on CHROMagar Candida medium. Mitochondrial DNA restriction analysis was performed to compare Candida isolates from both partners. RESULTS: A total of 64 couples were enrolled in the study. Frequency of sexual intercourse was significantly higher in couples where both partners yielded positive cultures and with at least one having genital candidosis (Odds ratios: 6.844; 95% CI 1.408-33.266). The same Candida species was found in both partners in 25% (16/64) of all couples but only 17.2% (11/64) were genetically similar. In total 12 of the 34 women suffering from vulvovaginal candidosis (VVC) had recurrent VVC (RVVC); two sexual partners of RVVC women (16.7%) had candida positive cultures, compared with 15 (68.2%) sexual partners of non RVVC women (Odds ratios: 0.093; 95% CI 0.016-0.544). CONCLUSIONS: Only in a few heterosexual couples a genetic similarity of Candida species recovered from both partners was found. RVVC women were more likely to have an asymptomatic candida negative sexual partner. This study suggests that male genitalia do not represent a relevant reservoir for RVVC; thus, the relevance of sexual transmission should not be emphasized.
Subject(s)
Candidiasis, Cutaneous/epidemiology , Candidiasis, Cutaneous/transmission , Genital Diseases, Female/epidemiology , Genital Diseases, Male/epidemiology , Heterosexuality , Adult , Candida/genetics , Candida/isolation & purification , Candidiasis, Cutaneous/genetics , Female , Genital Diseases, Female/genetics , Genital Diseases, Male/genetics , Genotype , Humans , Male , Middle Aged , Penis/microbiology , Portugal , Prevalence , Retrospective Studies , Vagina/microbiology , Vulva/microbiologyABSTRACT
Atualmente o uso de métodos alternativos para o controle de doenças e pragas na agricultura, visando minimizar os danos ao meio ambiente e à saúde pública é uma prática reconhecida e necessária. Este trabalho objetivou investigar a ação do óleo essencial de Syzygium aromaticum (L.) Merr. & L.M.Perry sobre o crescimento micelial in vitro dos fungos fitopatogênicos Rhizoctonia solani, Fusarium solani, Fusarium oxysporum e Macrophomina phaseolina. A análise por cromatografia gasosa acoplada com espectrometria de massa possibilitou a identificação de eugenol (83,6 por cento), acetato de eugenila (11,6 por cento) e cariofileno (4,2 por cento). A avaliação microscópica dos micélios dos fungos evidenciou diversas alterações morfológicas, como a presença de vacúolos, desorganização dos conteúdos celulares, diminuição na nitidez da parede celular, intensa fragmentação e menor turgência das hifas. O óleo essencial de cravo apresentou atividade fungicida na concentração de 0,15 por cento sobre o crescimento de R. solani, F. oxysporum e F. solani, entretanto não demonstrou essa atividade sobre M. phaseolina. Esses resultados indicam perspectivas favoráveis para posterior uso do óleo de cravo no controle desses fitopatógenos na agricultura.
Currently, the use of alternative methods to control diseases and pests in agriculture has been a recognized and necessary practice to minimize damages to the environment and public health. This study aimed to investigate the action of clove [Syzygium aromaticum (L.) Merr. & L.M.Perry] essential oil on the in vitro mycelial growth of the phytopathogenic fungi Rhizoctonia solani, Fusarium solani, Fusarium oxysporum and Macrophomina phaseolina. Analysis by gas chromatography-mass spectrometry allowed the identification of eugenol (83.6 percent), eugenyl acetate (11.6 percent) and caryophyllene (4.2 percent). Microscopic evaluation of mycelia showed several morphological changes such as presence of vacuoles, cell content disorganization, decreased cell wall clearness, intense fragmentation and lower turgescence of hyphae. Clove essential oil showed fungicidal activity at 0.15 percent on the growth of R. solani, F. oxysporum and F. solani, but not for M. phaseolina. These results indicate favorable perspectives for future use of clove essential oil to control these phytopathogens in agriculture.
Subject(s)
Eugenia/parasitology , Eugenia/chemistry , Fungi , Hyphae/isolation & purification , Oils, Volatile/analysis , Oils, Volatile/adverse effects , Antifungal Agents/analysis , Antifungal Agents/toxicityABSTRACT
In this work argon and nitrogen were implanted into ZnO single crystals in order to compare the influence of these non-magnetic elements in the magnetic and electrical behaviour of zinc oxide. The results indicate that both nitrogen and argon implantations induce magnetic defects in ZnO, although these do not remain stable upon annealing. The comparison between the electrical behaviour of argon and nitrogen implanted crystals indicates that mobile charge carriers exist in the argon implanted sample after annealing, but were not detected in the nitrogen implanted sample.
ABSTRACT
BACKGROUND AND PURPOSE: Adding spironolactone to standard therapy in heart failure reduces morbidity and mortality, but the underlying mechanisms are not fully understood. We analysed the effect of canrenone, the major active metabolite of spironolactone, on myocardial contractility and intracellular calcium homeostasis. EXPERIMENTAL APPROACH: Left ventricular papillary muscles and cardiomyocytes were isolated from male Wistar rats. Contractility of papillary muscles was assessed with force transducers, Ca(2+) transients by fluorescence and Ca(2+) fluxes by electrophysiological techniques. KEY RESULTS: Canrenone (300-600 micromol L(-1)) reduced developed tension, maximum rate of tension increase and maximum rate of tension decay of papillary muscles. In cardiomyocytes, canrenone (50 micromol L(-1)) reduced cell shortening and L-type Ca(2+) channel current, whereas steady-state activation and inactivation, and reactivation curves were unchanged. Canrenone also decreased the Ca(2+) content of the sarcoplasmic reticulum, intracellular Ca(2+) transient amplitude and intracellular diastolic Ca(2+) concentration. However, the time course of [Ca(2+)](i) decline during transients evoked by caffeine was not affected by canrenone. CONCLUSION AND IMPLICATIONS: Canrenone reduced L-type Ca(2+) channel current, amplitude of intracellular Ca(2+) transients and Ca(2+) content of sarcoplasmic reticulum in cardiomyocytes. These changes are likely to underlie the negative inotropic effect of canrenone.
Subject(s)
Calcium Channels, L-Type/drug effects , Calcium/metabolism , Canrenone/pharmacology , Mineralocorticoid Receptor Antagonists/pharmacology , Animals , Caffeine/pharmacology , Calcium Channels, L-Type/metabolism , Canrenone/administration & dosage , Dose-Response Relationship, Drug , Homeostasis , Male , Mineralocorticoid Receptor Antagonists/administration & dosage , Myocardial Contraction/drug effects , Myocytes, Cardiac/drug effects , Myocytes, Cardiac/metabolism , Papillary Muscles/drug effects , Papillary Muscles/metabolism , Rats , Rats, Wistar , Sarcoplasmic Reticulum/metabolism , Spironolactone/metabolismABSTRACT
The aim of this study was to determine the role of polysaccharide intercellular adhesin (PIA) in Staphylococcus epidermidis adhesion to host tissues and subsequent antibiotic tolerance. The adherence of S. epidermidis 1457 and the mutant defective in PIA production (1457-M10) to urinary epithelium and endothelium was estimated by colony counting. Minimum bactericidal concentration and mean reduction of cellular activity (XTT) following antibiotic exposure was determined for planktonic and adhered bacteria. S. epidermidis 1457 adhered to a greater extent to both cells than the mutant strain. The adhered strains had a significantly higher antimicrobial tolerance than their planktonic counterparts. The mutant strain was, in general, the most susceptible to the antibiotics assayed. In conclusion, PIA may influence S. epidermidis adherence to host tissues and their antimicrobial susceptibility. Initial adhesion may be the main step for the acquisition of resistance in S. epidermidis.
Subject(s)
Anti-Bacterial Agents/pharmacology , Bacterial Adhesion , Polysaccharides, Bacterial/physiology , Staphylococcus epidermidis/drug effects , Staphylococcus epidermidis/pathogenicity , Animals , Cell Line , Endothelial Cells/microbiology , Epithelial Cells/microbiology , Humans , Microbial Sensitivity Tests , Microbial Viability , Mutation , Polysaccharides, Bacterial/genetics , Tetrazolium Salts/metabolismABSTRACT
CASE: We report the rare case of a 39-year-old woman who had an intra-partum hemoperitoneum that resulted from spontaneous rupture of the utero-ovarian vessels. During the expulsive efforts, the patient repeatedly complained of bilateral shoulder discomfort and some respiratory difficulty. Because she had hemodynamic instability and an abdomino-pelvic ultrasound revealed the presence of extensive free fluid within the peritoneal cavity, the patient underwent an exploratory laparotomy. The surgery revealed an extensive laceration of the anterior leaf of the left broad ligament and vesico-uterine peritoneum, and active bleeding from the utero-ovarian vessels with no evidence of uterine rupture. CONCLUSION: Intra-partum haemoperitoneum resulting from rupture of the utero-ovarian vessels is a rare obstetrical emergency that needs rapid resuscitation with fluid and/or blood replacement and prompt surgical intervention.
Subject(s)
Broad Ligament/blood supply , Hemoperitoneum/surgery , Ovary/blood supply , Pregnancy Complications, Cardiovascular/surgery , Uterus/blood supply , Adult , Female , Hemoperitoneum/etiology , Humans , Pregnancy , Pregnancy Complications, Cardiovascular/etiology , Rupture, Spontaneous , Uterus/surgeryABSTRACT
Water samples (24 untreated water, 12 treated water and 24 served water) used in different stages of the slaughter process were examined to identify a possible source of pathogenic mycobacteria. The isolates were identified based on microscopy, morphological and biochemical features, mycolic acid analysis and molecular method--PCR-restriction-enzyme analysis. Eighteen mycobacterial strains were isolated from 60 water samples: 11 from untreated water, 5 from treated water and 2 from served water. All mycobacteria isolated were identified as Mycobacterium gordonae and showed the following PRA genotypes: III (27.8%), IV (38.9%) and V (33.3%).
Subject(s)
Abattoirs , Mycobacterium Infections, Nontuberculous/veterinary , Nontuberculous Mycobacteria/isolation & purification , Poultry Diseases/microbiology , Poultry/microbiology , Waste Disposal, Fluid , Water Microbiology , Animals , Brazil/epidemiology , Disease Vectors , Filtration , Food Contamination/prevention & control , Food Handling , Meat , Mycobacterium Infections, Nontuberculous/epidemiology , Mycobacterium Infections, Nontuberculous/microbiology , Nontuberculous Mycobacteria/genetics , Poultry Diseases/epidemiology , Water Pollution , Water Purification/methodsABSTRACT
Water samples (24 untreated water, 12 treated water and 24 served water) used in different stages of the slaughter process were examined to identify a possible source of pathogenic mycobacteria. The isolates were identified based on microscopy, morphological and biochemical features, mycolic acid analysis and molecular method--PCR-restriction-enzyme analysis. Eighteen mycobacterial strains were isolated from 60 water samples: 11 from untreated water, 5 from treated water and 2 from served water. All mycobacteria isolated were identified as Mycobacterium gordonae and showed the following PRA genotypes: III (27.8
) and V (33.3