Interaction between the impact of the Coronavirus disease 2019 pandemic and demographic characteristics on sexual/erectile dysfunction in Latin America: cross-sectional study

Aim:

Our objective was to investigate whether there is an interaction between the COVID-19 pandemic, demographic characteristics and erectile/sexual (E/S) function in individuals from Latin America.

Materials and Methods:

Cross-sectional study which included Latin American individuals over 18 years old, recruited through social media and interviewed between July and August 2020 by online surveys (Google Forms) in Portuguese and Spanish languages. The E/S function was evaluated through the following questionnaires: Simplified International Index of Erectile Function (IIEF-5) and Female Sexual Function Index (FSFI); while post-traumatic stress disorder (PTSD) triggered by the COVID-19 pandemic was assessed through the Impact of Event Scale Revised (IES-R). The data was analyzed by T Student, bivariate and multivariate logistic regression, with significance determined by the Wald test (p<0.05), using the R software v4.0.

Results:

Out of the 2016 individuals that responded to the survey, 1986 were included and 743 of them presented E/S dysfunction. PTSD occurrence was greater among people with E/S dysfunction when compared to those without E/S dysfunction, in the total score (males: IES-R=26.54[±19.17] and females: IES-R=35.92[±19.25]) and also in the three domains. It was found that those who do not live with a partner were 74% more likely to have E/S dysfunction, but living with a partner during the pandemic had a greater impact on E/S function.

Conclusion:

A negative interaction between the impact of the COVID-19 pandemic and erectile/sexual function of the Latin American population was observed, with greater implications among the individuals who live with their partners.

Enamel Mineral Content Changes After Bleaching With High and Low Hydrogen Peroxide Concentrations: Colorimetric Spectrophotometry and Total Reflection X-ray Fluorescence Analyses

The purpose of this study was to evaluate the calcium (Ca) and phosphorous (P) content in enamel bleached with high and low concentrations of hydrogen peroxide (HP) using Total Reflection X-Ray Fluorescence (TXRF) and colorimetric spectrophotometry (SPEC). Forty-eight sound human third molars were used. Their roots were embedded in polystyrene resin and immersed for seven days in an artificial saliva solution. Then they were distributed into six groups to receive the bleaching treatments. The agents of high HP concentration (for in-office use) evaluated were Whiteness HP Maxx/FGM (35% HP), Whiteness HP Blue/FGM (35% HP, 2% calcium gluconate), Pola Office+/SDI (37.5% HP, 5% potassium nitrate), and Opalescence Boost/Ultradent (38% HP, 1.1% ion fluoride, 3% potassium nitrate); these agents were applied to enamel in three sessions. The agents of low HP concentration (for home use) evaluated were Pola Day/SDI (9.5% HP) and White Class 10%/FGM (10% HP, potassium nitrate, calcium, fluoride), and these agents were applied for 14 days. Enamel microbiopsies were evaluated by TXRF and SPEC analysis before the bleaching treatment (baseline), during the treatment, and 14 days after the end of the treatment. For TXRF, the Kruskal-Wallis test showed that Ca and P were not influenced by agent (p>0.05). For SPEC, Pola Office+, Opalescence Boost, Pola Day, and White Class 10% caused a decrease of Ca over time; there was a significant decrease of P over time to Pola Office+ and White Class 10%. The Spearman test showed no correlation between the Ca (p=0.987; r²=-0.020) and P (p=0.728, r²=0.038) obtained by SPEC and TXRF. For TXRF and SPEC, changes in Ca and P during bleaching occurred independently of the HP concentration used.

Heavy Metal Content in Chilean Fish Related to Habitat Use, Tissue Type and River of Origin

In this study, we analyze the concentration of ten metals in two freshwater fish-the benthic catfish Trichomycterus areolatus and the limnetic silverside Basilichthys microlepidotus-in order to detect possible accumulation differences related to fish habitat (benthic or pelagic), tissue type (gill, liver and muscle), and the river of origin (four different rivers) in central Chile. The MANOVA performed with all variables and metals, revealed independent effects of fish, tissue and river. In the case of the fish factor, Cu, Cr, Mo and Zn showed statistically higher concentrations in catfish compared with silverside for all tissues and in all rivers (p < 0.05). In the case of the tissue factor, Al, Cr, Fe and Mn had statistically higher concentrations in liver and gills than in muscle (p  < 0.05). For the river effect, the analysis showed higher concentrations of Cr, Mn and Pb in the Cogoti river and the lower concentrations in the Recoleta river. These results suggest that not all metals have the same pattern of accumulation; however, some metals tend to accumulate more in readily catfish, probably due to their benthic habit, and in liver and gill tissue, probably as a result of accumulation from food sources and respiration.

First Report of Rust Caused by Puccinia psidii on Eucalyptus dunnii in Uruguay

Eucalypt rust caused by Puccinia psidii Winter represents a major disease affecting eucalypt production in South America, and is threatening myrtaceous hosts worldwide. In Uruguay, it was first detected infecting Eucalyptus globulus in 2001 (4) and later on E. grandis, Myrrhinium atropurpureum, and Myrcianthes pungens, two myrtaceae hosts native to Uruguay (3). Over the summer 2013, bright orange-yellowish pustules were detected on stock plants of E. dunnii in a nursery located in western Uruguay, province of Paysandú. A severe and explosive epidemic was readily observed. Affected leaves were taken to the laboratory and examined under the microscope. Uredinia and urediniospores were similar with those described previously in Uruguay on other hosts (3,4). Uredioniospores were 18 to 25 × 15 to 21 μm, yellow, unicellular, spherical to elliptical, base truncate, finely and uniformly echinulate with spines up to 1 μm long, with an evident bald patch without spines. To confirm identity of this fungus, genomic DNA was extracted from single-pustule urediniospores, and ITS region was amplified using primers PR1 and PR2 (1) with PCR conditions previously described (3). Forward and reverse sequences from three single pustules were obtained, assembled, and compared with those available in GenBank using BLAST searches. Obtained sequences showed to be identical to those analyzed by Pérez et al. (2011) collected from E. grandis and E. globulus, with no variation found in the analyzed region. A 100% identity was found with isolates UY1374 and UY1375 obtained from E. globulus, and with isolate UY1731 obtained from E. grandis (FJ710805, FJ710806, and FJ710807, respectively). Sequences were deposited in GenBank with accession numbers KM083129, KM083130, and KM083131. Even though this pathogen is known to occur in a wide variety of myrtaceous species, to our knowledge, this is the first natural infection record of P. psidii on E. dunnii in Uruguay and worldwide. This report confirms previous studies that indicated the susceptibility of E. dunnii when inoculated under controlled conditions (2,5). E. dunnii is being widely planted in Uruguay, eastern Argentina, and southern Brazil, with increasing significance to the pulp industry. Although the consequences of this finding have yet to be realized, scouting plantations is essential to estimate the real impact of this pathogen on this tree species. Our study contributes to expand the host range known for this globally important pathogen. References: (1) S. R. H. Langrell et al. Plant Pathol. 57:687, 2008. (2) L. Morin et al. PLoS ONE 7:e35434, 2012. (3) C. A. Pérez et al. Mycol. Progress 10:273, 2011. (4) N. Telechea et al. Plant Pathol. 52:427, 2003. (5) E. A. V. Zauza et al. Australas. Plant Pathol. 39:406, 2010.

Brownian dynamics simulation of monolayer formation by deposition of colloidal particles: a kinetic study at high bulk particle concentration

Brownian dynamics simulations (BDS) of sedimentation and irreversible adsorption of colloidal particles on a planar surface were carried out at bulk particle volume fractions (φ) in the range 0.05 to 0.25. The sedimentation and adsorption of colloidal particles were simulated as a non-sequential process that allows simultaneous settling and adsorption of particles. A kinetic model for the formation of particle monolayers based on the available surface fraction (θ(A)) is proposed to predict simulation results. The simulations show a value of 0.625 for the maximum fractional surface coverage (θ(∞)) and a monolayer structure insensitive to φ. However, the kinetic order of the monolayer formation process has a strong dependence with φ, changing from a value close to a unit, at low φ, to a value around two at high φ. This change in the kinetic reaction order is associated to differences of particle adsorption mechanism on the surface. At low φ values, the monolayer formation is achieved by independent adsorption of single particles and the reaction order is close to 1. At high φ values, the simultaneous adsorption of two particles on the surface leads to an increase of the reaction order to values close to 2.

CB.Hep-1 hybridoma growth and antibody production using protein-free medium in a hollow fiber bioreactor

The protein-free medium TurboDoma HP.1 (THP.1) was used to produce the CB.Hep-1 monoclonal antibody (mAb) in a CP-1000 hollow fiber bioreactor (HFB). This mAb is used for the immunopurification of recombinant hepatitis B surface antigen (rHBsAg), which is included in a vaccine preparation against the Hepatitis B Virus. By using the experimental conditions tested in this work we were able to generate more than 433 mg of IgG in 43 days. The maximum antibody concentration obtained was about 2.4 mg ml(-1)and the IgG production per day was approximately 11 mg of monoclonal antibody, which constitutes a good concentration value in comparison to the results obtained in ascitic fluid, where concentration for this hybridoma was around 3 mg ml(-1). We used different analytical methods to control the quality of mAbs, obtained from the in vitro system. They included affinity constant determination, analysis of N-glycan structures, immunoaffinity chromatography and antigen binding properties. The results obtained suggest that no significant changes occurred in the mean characteristics of the mAb harvested from the bioreactor during the 43 days of cultivation.

Biological tissues analysis by XRF microtomography

The main of this work is to determine the elemental distribution in breast and prostate tissue samples in order to verify the concentration of some elements correlated with characteristics and pathology of each tissue observed by the X-ray transmission microtomography (microCT). The experiments were performed at the X-ray fluorescence beamline of the Brazilian Synchrotron Light Laboratory. The microCT images were reconstructed using a filtered-back-projection algorithm and the XRF microtomographies were reconstructed using a filtered-back-projection algorithm with absorption corrections.

Metal-binding proteins scanning and determination by combining gel electrophoresis, synchrotron radiation X-ray fluorescence and atomic spectrometry

In the present work, protein bands from in vitro embriogenic callus (Citrus sinensis L. Osbeck) were investigated using micro-synchrotron radiation X-ray fluorescence (muSR-XRF) after sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) separation. Metal-binding protein quantification was done after microwave oven decomposition of gel by synchrotron radiation total reflection X-ray fluorescence (SR-TXRF), flame atomic absorption spectrometry (FAAS) and flame atomic emission spectrometry (FAES). According to the analysis of the protein bands, it is possible to observe that both 81 and ca. 14 kDa proteins present different Fe signal intensity at different positions. The analysis of 53 kDa protein, showed even more interesting results. Besides Fe, the muSR-XRF experiments indicate the presence of Ca, Cu, K and Zn. Chemical elements such as Cu, K, Fe and Zn were determined by SR-TXRF, Mg by FAAS and Na by FAES. Ca was determined by SR-TXRF and FAAS only for accuracy check. In the mineralised protein bands of 81 and around 14 kDa band, only Fe was determined (105 and 21.8 microg g(-1)). For those protein bands (86-ca. 14 kDa) were determined, Ca, K, Cu and Zn in a wide concentration range (42.4-283, 2.47-96.8, 0.91-15.9 and 3.39-29.7 microg g(-1), respectively).

Genetic polymorphism at position-308 in the promoter region of the tumor necrosis factor (TNF): implications of its allelic distribution on susceptibility or resistance to diseases in the Chilean population

Several single-nucleotide polymorphisms have been identified in the human TNF gene promoter. The polymorphism at position-308 (TNF-308), which involves substituting G for A and designing the TNF2 allele, leads to a higher rate of TNF gene transcription than the wild-type TNF1 allele in in vitro expression studies. It has also been linked to increased susceptibility to a variety of illnesses. Using PCR-RFLP analysis we detected significant differences in the TNF-308 genotypes of Chilean and other populations. We conclude that there is a gradient in the distribution of the TNF2 allele according to ethnicity; we have also hypothesized that populations bearing a higher proportion of the TNF2 allele may have an increased predisposition toward or incidence of several chronic metabolic, degenerative, inflammatory and autoimmune diseases.

Zinc incorporation in human dental calculus

We present here the first study of the local environment of zinc ions in biological calcium phosphates. It was suggested from in vitro studies that zinc inhibits the formation of hydroxyapatite and promotes the formation of more soluble phases, like tricalcium phosphate. Several mechanisms of zinc - calcium phosphate interaction were proposed, yielding either to the adsorption or to the incorporation of zinc ions into the phosphate structure. The results obtained here show that, under in vivo conditions, the zinc atoms are fully incorporated into the crystalline structure of the calcium phosphates.

Expert-system classification of sleep/waking states in infants

This work is part of a project to develop an expert system for automated classification of the sleep/waking states in human infants; i.e. active or rapid-eye-movement sleep (REM), quiet or non-REM sleep (NREM), including its four stages, indeterminate sleep (IS) and wakefulness (WA). A model to identify these states, introducing an objective formalisation in terms of the state variables characterising the recorded patterns, is presented. The following digitally recorded physiological events are taken into account to classify the sleep/waking states: predominant background activity and the existence of sleep spindles in the electro-encephalogram; existence of rapid eye movements in the electro-oculogram; and chin muscle tone in the electromyogram. Methods to detect several of these parameters are described. An expert system based on artificial ganglionar lattices is used to classify the sleep/waking states, on an off-line minute-by-minute basis. Algorithms to detect patterns automatically and an expert system to recognise sleep/waking states are introduced, and several adjustments and tests using various real patients are carried out. Results show an overall performance of 96.4% agreement with the expert on validation data without artefacts, and 84.9% agreement on validation data with artefacts. Moreover, results show a significant improvement in the classification agreement due to the application of the expert system, and a discussion is carried out to justify the difficulties of matching the expert's criteria for the interpretation of characterising patterns.

Acetylcholinesterase accelerates assembly of amyloid-beta-peptides into Alzheimer's fibrils: possible role of the peripheral site of the enzyme

Acetylcholinesterase (AChE), an important component of cholinergic synapses, colocalizes with amyloid-beta peptide (A beta) deposits of Alzheimer's brain. We report here that bovine brain AChE, as well as the human and mouse recombinant enzyme, accelerates amyloid formation from wild-type A beta and a mutant A beta peptide, which alone produces few amyloid-like fibrils. The action of AChE was independent of the subunit array of the enzyme, was not affected by edrophonium, an active site inhibitor, but it was affected by propidium, a peripheral anionic binding site ligand. Butyrylcholinesterase, an enzyme that lacks the peripheral site, did not affect amyloid formation. Furthermore, AChE is a potent amyloid-promoting factor when compared with other A beta-associated proteins. Thus, in addition to its role in cholinergic synapses, AChE may function by accelerating A beta formation and could play a role during amyloid deposition in Alzheimer's brain.

Acetylcholinesterase, a senile plaque component, affects the fibrillogenesis of amyloid-beta-peptides

Acetylcholinesterase (AChE) colocalizes with amyloid-beta peptide (A beta) deposits present in the brain of Alzheimer's patients. Recent studies showed that A beta 1-40 can adopt two different conformational states in solution (an amyloidogenic conformer, A beta ac, and a non-amyloidogenic conformer, A beta nac) which have distinct abilities to form amyloid fibrils. We report here that AChE binds A beta nac and accelerates amyloid formation by the same peptide. No such effect was observed with A beta ac, the amyloidogenic conformer, suggesting that AChE acts as a 'pathological chaperone' inducing a conformational transition from A beta nac into A beta ac in vitro.

Sensitivity of acetylcholinesterase molecular forms to inhibition by high MgCl2 concentration

Previous studies have shown that the asymmetric (A12) and the dimeric (G2), but not the tetrameric (G4), acetylcholinesterase (AChE) forms are inactivated by high MgCl2 concentration (Perelman and Inestrosa (1989) Anal. Biochem. 180, 227-230). Here we show that the effect of MgCl2 on AChE activity corresponds to an irreversible inhibition and is not due to environmental effects related to the different extraction media. The anchor domain in each AChE form was not involved in the differential MgCl2 sensitivity. Monomers derived from the various AChE forms behave in a way similar to that of the original assembled forms. Purified AChE molecular forms showed the same sensitivity to MgCl2, than the same enzyme forms studied in tissue extracts. Neither the affinity for the substrate nor the inhibition by excess substrate of the residual AChE activity were affected by high MgCl2 concentration. Results indicate that the differences between the tetrameric enzyme and the other two AChE molecular forms occur at the level of the catalytic subunit, probably due to differential post-translational processing.

Radiation therapy in the management of cancer of the cervix

Patients with stage IB or IIA carcinoma of the uterine cervix can be treated with comparable results using either radical surgery or definitive radiotherapy. The treatment of choice for stage IIB and III tumors is radiotherapy alone. Although the efficacy of adjuvant chemotherapy has not been documented, several trials are evaluating the potential use of combined chemotherapy and irradiation in bulky or extensive lesions. In most patients, radiotherapy consists of a combination of external-beam irradiation of the pelvis and two intracavitary radioactive source insertions. This article reviews the basic principles of management of patients with cervical cancer and describes the radiotherapy techniques employed.