AI-Assisted Real-Time Immunoassay Improves Clinical Sensitivity and Specificity.

Real-time biosensing systems can interrogate the association between the analyte and the biorecognition element across time. Typically, the resulting data are preprocessed to offer valuable bioanalytical information obtained at a single optimal point of such a real-time response; for instance, a diagnosis of certain medical conditions can be established depending on a biomarker (analyte) concentration measured at an optimal time, that is, a threshold. Exploiting this conventional approach, we previously developed a nanophotonic immunoassay for bacterial vaginosis diagnosis exhibiting a clinical sensitivity and specificity of ca. 96.29% (n = 162). Herein, we demonstrate that a real-time biosensing platform assisted by artificial intelligence not only obviates biomarker concentration (i.e., a threshold) determination but also increases sensitivity and specificity in the targeted diagnostic, thereby reaching values of up to 100%.

Temporal and Spatial Trends of Adverse Pregnancy and Birth Outcomes in a Sample of Births from a Public Hospital in Chile.

Understanding temporal and spatial trends in pregnancy and birth outcomes within an urban area is important for the monitoring of health indicators of a population. We conducted a retrospective cohort study of all births in the public hospital of Temuco, a medium-sized city in Southern Chile between 2009 and 2016 (n = 17,237). Information on adverse pregnancy and birth outcomes, as well as spatial and maternal characteristics (insurance type, employment, smoking, age, and overweight/obesity), was collected from medical charts. Home addresses were geocoded and assigned to neighborhood. We tested whether births and prevalence of adverse pregnancy outcomes changed over time, whether birth events were spatially clustered (Moran's I statistic), and whether neighborhood deprivation was correlated to outcomes (Spearman's rho). We observed decreases in eclampsia, hypertensive disorders of pregnancy, and small for gestational age, while gestational diabetes, preterm birth, and low birth weight increased over the study period (all p < 0.01 for trend), with little changes after adjusting for maternal characteristics. We observed neighborhood clusters for birth rate, preterm birth, and low birth weight. Neighborhood deprivation was negatively correlated with low birth weight and preterm birth, but not correlated with eclampsia, preeclampsia, hypertensive disorders of pregnancy, small for gestational age, gestational diabetes, nor stillbirth. Several encouraging downward trends and some increases in adverse pregnancy and birth outcomes, which, overall, were not explained by changes in maternal characteristics were observed. Identified clusters of higher adverse birth outcomes may be used to evaluate preventive health coverage in this setting.

Measurement of Protein Kinetics Using a Liquid Phase-Based Biosensing Platform.

Macromolecular association is crucial to many fields in biomedical sciences, including drug development, gene editing, and diagnostics. In particular, protein-protein association and dissociation rate constants are typically determined using surface plasmon resonance systems, which require costly instrumentation and cumbersome procedures (e.g., blocking, washing, and separation). Herein, we demonstrate that protein-binding constants can be readily determined using a real-time biosensing platform facilitated by graphene oxide-modified microwell plates and fluorophore-labeled proteins, where the fluorescent probes remain highly fluorescent during protein association, whereas fluorescent bioprobes that are not associated with their counterparts are quenched by graphene oxide. Binding data of three pairs of proteins were systematically determined employing this single-step platform and compared with those data reported by the suppliers or the literature, suggesting that this approach is comparable and consistent with the existing ones. Such pairs include (i) human immunoglobulin G (H-IgG)-fluorophore-labeled anti-H-IgG, (ii) prostate-specific antigen (PSA)-quantum dot-labeled anti-PSA, and (iii) anti-RBD-fluorophore-labeled SARS-CoV-2 spike receptor-binding domain recombinant protein. We also offer an open-source software that automatically determines the binding kinetics constants of proteins. This Technical Note introduces a simple, yet effective, platform to determine relevant information on protein kinetics, which can be performed using a microwell plate reader and economical materials like graphene oxide. We foresee a new generation of diagnostics based on our affordable protein kinetics analysis.

High altitude exposure affects male reproductive parameters: could it also affect the prostate?†.

Living at high altitudes and living with prostatic illness are two different conditions closely related to a hypoxic environment. People at high altitudes exposed to acute, chronic or intermittent hypobaric hypoxia turn on several mechanisms at the system, cellular, and molecular level to cope with oxygen atmosphere scarcity maintaining the oxygen homeostasis. This exposure affects the whole organism and function of many systems, such as cardiovascular, respiratory, and reproductive. On the other hand, malignant prostate is related to the scarcity of oxygen in the tissue microenvironment due to its low availability and high consumption due to the swift cell proliferation rates. Based on the literature, this similarity in the oxygen scarcity suggests that hypobaric hypoxia, and other common factors between these two conditions, could be involved in the aggravation of the pathological prostatic status. However, there is still a lack of evidence in the association of this disease in males at high altitudes. This review aims to examine the possible mechanisms that hypobaric hypoxia might negatively add to the pathological prostate function in males who live and work at high altitudes. More profound investigations of hypobaric hypoxia's direct action on the prostate could help understand this exposure's effect and prevent worse prostate illness impact in males at high altitudes.

Effects of chronic intermittent hypobaric hypoxia on prostate-specific antigen (PSA) in Chilean miners.

OBJECTIVE: The aim was to determine the effects of chronic intermittent hypobaric hypoxia (CIHH) on prostate-specific antigen (PSA) levels in Chilean miners who work at different altitudes. METHODS: A cross-sectional study was conducted between April and July 2019. Miners from five mines (N=338) at different altitudes were evaluated. We recorded sociodemographic, working and altitude information. Haemoglobin oxygen saturation (SaO2) and haemoglobin (Hb) were measured in situ, while PSA and testosterone were analysed at a low level. Linear mixed-effect models were used to evaluate the association between PSA level and two CIHH exposures: composite CIHH (with four descriptors) and ChileStd-CIHH (CIHH Chilean standard; based on the Chilean technical guide for occupational exposure to CIHH). All models were adjusted by age, body mass index and day of the work the samples were taken. RESULTS: Highest and lowest PSA levels were found in mines ≥3000 m above sea level (mine 3: median=0.75, IQR=-0.45; mine 4: median=0.46, IQR=-0.35). In the multilevel models, the wider altitude difference between mining operation and camp showed lower PSA levels (model D: ßPSA=-0.93 ng/mL, ßlogPSA=-0.07, p<0001), adjusted for other CIHH descriptors, SaO2, Hb and testosterone. The descriptors of composite CIHH explained better PSA variations than ChileStd-CIHH (model D: marginal R2=0.090 vs model A: marginal R2=0.016). CONCLUSIONS: Occupational health regulations and high altitude medicine should consider these results as initial evidence on the inclusion of new descriptors for CIHH and the possible effect of this exposure on PSA levels in this male-dominated occupational sector.

Real-Time Photoluminescent Biosensing Based on Graphene Oxide-Coated Microplates: A Rapid Pathogen Detection Platform.

Pathogenic bacterial contamination is a major threat to safety, human health, and ecosystems. Herein, we report an advantageous single-step, wash-free, and real-time bacterial detection platform operating with a single antibody. Escherichia coli was detected as a model analyte. This technology is based on graphene oxide-coated microplates (GOMs) and photoluminescent bioprobes (PLBs). On the one hand, using nonradiative energy transfer, GOMs are conceived to deactivate the photoluminescence of those PLBs that are not experimenting immunoreactions via antibody-bacterial membrane affinity. On the other hand, those PLBs experimenting immunoreactions preserve their photoluminescence because of both (i) the distance between the complex (PLBs-bacteria) and GOMs and (ii) the low affinity between the same complex and GOMs. With an optimal analytical performance of ∼30 min, the resulting bacterial detection platform was demonstrated to be fast and highly sensitive, exhibiting a limit of detection of ∼2 CFU mL-1. Industrial real samples were also successfully analyzed in a widely used format that is amenable to high-throughput applications. Moreover, the proposed technology is highly transformative, as graphene oxide is able to quench different fluorophores, and other analytes can be detected by simply changing the specific antibody.

Heart rate variability, salivary cortisol and competitive state anxiety responses during pre-competition and pre-training moments.

The study aimed to investigate physiological and psychological states prior to competition and prior to training in three different demanding activities. Eighteen canoe athletes, 18 street runners and 18 jiu-jitsu fighters were included in this study (n=54). The Competitive State Anxiety Inventory-2 (CSAI-2), salivary cortisol and heart rate variability (HRV) were measured at two time points (pre-training and pre-competition). Somatic anxiety (F1,42 = 15.29, p = 0.0003), HRV (F1,42 = 23.24, p < 0.0001) and salivary cortisol (F1,42 = 22.96, p < 0.0001) were significantly greater at the pre-competition measurement point than at the pre-training point, but without a main effect of the type of athlete on these variables. A main effect of the type of athlete was found on somatic anxiety (F2,42 = 6.58, p = 0.0033), cognitive anxiety (F2,42 = 10.69, p = 0.0002) and self-confidence (F2,42 = 5.42, p = 0.0080). Correlations between most CSAI-2 and physiological parameters were not significant (p > 0.05). In conclusion, the results indicated that both emotional indices and psychophysiological indices of stress are higher before competition than before training, with differences between emotional states between these sports. Although correlations between emotional states and psycho-physiological states before competition and before training were largely non-significant, these findings reinforce the importance of psychological monitoring of athletes in association with traditional physiological markers such as cortisol and HRV in sportive training programmes as complementary resources to improve both competition performance and the training routine.

Association of serum hepcidin with prostate-specific antigen levels in men from high Andean cities of Peru.

Objective: The prostate-specific antigen (PSA) is the primary biomarker to diagnose prostate cancer. Hepcidin has been reported as an alternative for this diagnosis; however, it is unclear how PSA and hepcidin function at high altitude (HA). This study aims to assess the association between hepcidin with PSA in HA residents chronically exposed to hypobaric hypoxia. Methods: We retrospectively examined data of 70 healthy males (aged 18-65-years-old) from four different altitudes cities in Peru: Lima (<150 m), Huancayo (2380 m), Puno (3800 m), and Cerro de Pasco (4320 m). Serum hepcidin, testosterone, and PSA were analyzed by chemiluminescence immunoassay. HA parameters (hemoglobin [Hb], pulse oxygen saturation [SpO2], and chronic mountain sickness [CMS] score) were also included in the study. Bivariate analyses and a multivariate linear mixed model were used to evaluate the association between hepcidin and PSA, adjusted by HA parameters, age, and body mass index (BMI). Results: Cases of excessive erythrocytosis (EE) (Hb >21 g/dL) were observed in the three highest cities. Hepcidin was positively correlated with Hb, CMS score, and BMI (P ≤ 0.05). Hepcidin was higher in Huancayo with respect to Puno, while PSA was lower in Cerro de Pasco in regard to Puno and Lima (P ≤ 0.05). Neither hepcidin nor PSA was increased by altitude in each city (P > 0.05). We did not find an association between hepcidin and PSA, even adjusted by age, BMI, Hb, and SpO2 (P ≤ 0.05). Conclusion: These findings showed no association between hepcidin and PSA levels in healthy residents at HA.

Varicocele at High Altitude; Venous Outflow Restriction by Hypobaric Hypoxia.

BACKGROUND: Testicular aches have been reported to occur on exposure to high altitude (HA). As a painful expression of venous congestion at the pampiniform plexus, varicocele (VC) might be a consequence of cardiovascular adjustments at HA. Chile's National Social Security Regulatory Body (SUSESO) emphasized evaluating this condition in the running follow-up study "Health effects of exposure to chronic intermittent hypoxia in Chilean mining workers." OBJECTIVES: This study aimed at investigating the prevalence of VC in a population usually shifting between sea level and HA, thereby intermittently being exposed to hypobaric hypoxia. METHODOLOGY: Miners (n=492) agreed to be examined at their working place by a physician, in the context of a general health survey, for the presence of palpable VC, either visible or not. Among them was a group exposed to low altitude (LA) <2,400 m; n=123; another one exposed to moderate high altitude (MHA) working 3,050 m; n=70, and a third one exposed to very high altitude (VHA) >3,900 m, n=165. The Chi2 test and Kruskal-Wallis test were used for the descriptive analyses, and logistic regression was applied to evaluate the association of VC with exposure to HA. The Ethics Committee for Research in Human Beings, Faculty of Medicine, University of Chile, approved this project. RESULTS: VC prevalence (grades 2 and 3) was found to be 10% at LA, 4.1% at MHA, and 16.7% at VHA (p≤0.05). Hemoglobin oxygen saturation (SaO2) was lower, and hemoglobin concentrations were higher in workers with high-grade VC at VHA compared to LA and MHA (Wilcoxon tests, p<0.001). Odds ratios (OR) for the association of VC with HA were 3.7 (95%CI: 1.26 to 12.3) and 4.06 (95%CI: 1.73 to 11.2) for MHA and VHA, respectively. CONCLUSION: Association of VC with HA, a clinically relevant finding, may be related to blood volume centralization mediated by hypobaric hypoxia.

Development of a Method for Detecting and Estimating Moniliophthora roreri Spore Loads Based on Spore Traps and qPCR.

Frosty pod rot, caused by Moniliophthora roreri, is the most damaging disease of cacao in Latin America and, to better comprehend its epidemiology, we must understand its dissemination and proliferation. However, we do not know how M. roreri spores loads fluctuate in time and space due to the lack of a reliable technique to quantify M. roreri spores in the fields. Therefore, we developed a method that relies on spore traps and qPCR to detect and quantify M. roreri spore loads. This study demonstrated that the qPCR protocol can detect down to 0.025 ng of M. roreri DNA and quantify between 0.006 ng and 60 ng. Moreover, it demonstrated that qPCR protocol can detect and quantify DNA extracted from spore suspension and spore traps containing at least 2.9 × 104 M. roreri spores. However, the variability of the estimates for spore samples was high. Finally, we described a spore-trap device designed to carry spore traps in the field. The qPCR protocol and spore-trap device here developed will help in the understanding of the M. roreri dissemination patterns since they can be used to assess the environmental loads of M. roreri spore in cacao fields.

Long-term tillage effect on with-in season variations in soil conditions and respiration from dryland winter wheat and soybean cropping systems.

Soil respiration from agricultural soils is a major anthropogenic source of CO2 to the atmosphere. With-in season emission of soil CO2 from croplands are affected by changes in weather, tillage, plant row spacing, and plant growth stage. Tillage involves physical turning of soils which accelerate residue decomposition and CO2 emission. No-tillage lacks soil disturbance and residues undergo slower decomposition at the surface. In this study, we compared with-in season soil conditions (temperature and moisture) and soil respiration from two major crops (soybean and winter wheat) by making high temporal frequency measurements using automated chambers at half-hourly intervals. The experiment lasted for 179 days. Total number of measurements made from conventional and no-tillage soybean and winter wheat plots were 6480 and 4456, respectively. Average flux after the winter-dormancy period of wheat was 37% higher in tilled soil compared to no-till soil. However, average flux during the soybean growing season was 8% lower in conventional till compared to no-till soil. This differential response of soil respiration in wheat and soybean was primarily due to tillage-induced changes in surface characteristics (residue cover) and soil environmental conditions (soil temperature and soil moisture). Results from this study can help elucidate relationships for modeling and assessment of field-scale soil CO2 emissions from dryland wheat and soybean crops grown in sub-tropics.

Health Effects of Chronic Intermittent Hypoxia at a High Altitude among Chilean Miners: Rationale, Design, and Baseline Results of a Longitudinal Study.

OBJECTIVES: This study aims to assess the health effects on mining workers of exposure to chronic intermittent hypoxia (CIH) at high- and very high-altitude mining compared with similar work at lower altitudes in Chile, and it also aims to constitute the baseline of a 5-year follow-up study. METHODS: We designed a cross-sectional study to assess health conditions in 483 miners working at 2 levels of altitude exposure: 336 working at a very high or high altitude (HA; 247 above 3900-4400 m, and 89 at 3000-3900 m), and 147 below 2400 m. Subjects were randomly selected in two stages. First, a selection of mines from a census of mines in each altitude stratum was made. Secondly, workers with less than 2 years of employment at each of the selected mines were recruited. The main outcomes measured at the baseline were mountain sickness, sleep alterations, hypertension, body mass index, and neurocognitive functions. RESULTS: Prevalence of acute mountain sickness (AMS) was 28.4% in the very high-altitude stratum (P = 0.0001 compared with the low stratum), and 71.7% experienced sleep disturbance (P = 0.02). The adjusted odds ratio for AMS was 9.2 (95% confidence interval: 5.2-16.3) when compared with the very high- and low-altitude groups. Motor processing speed and spatial working memory score were lower for the high-altitude group. Hypertension was lower in the highest-altitude subjects, which may be attributed to preoccupational screening even though this was not statistically significant. CONCLUSIONS: Despite longer periods of acclimatization to CIH, subjects continue to present AMS and sleep disturbance. Compromise of executive functions was detected, including working memory at HA. Further rigorous research is warranted to understand long-term health impacts of high-altitude mining, and to provide evidence-based policy recommendations.

Association between maximum temperature and PM2.5 with pregnancy outcomes in Lima, Peru.

BACKGROUND: We have previously documented an inverse relationship between PM2.5 in Lima, Peru, and reproductive outcomes. Here, we investigate the effect of temperature on birth weight, birth weight-Z-score adjusted for gestational age, low birth weight, and preterm birth. We also explore interactions between PM2.5 and temperature. METHODS: We studied 123,034 singleton births in three public hospitals of Lima with temperature and PM2.5 during gestation between 2012 and 2016. We used linear, logistic, and Cox regression to estimate associations between temperature during gestation and birth outcomes and explored possible modification of the temperature effect by PM2.5. RESULTS: Exposure to maximum temperature in the last trimester was inversely associated with both birth weight [ß: -23.7; 95% confidence interval [CI]: -28.0, -19.5] and z-score weight-for-gestational-age (ß: -0.024; 95% CI: -0.029, -0.020) with an interquartile range of 5.32 °C. There was also an increased risk of preterm birth with higher temperature (interquartile range) in the first trimester (hazard ratio: 1.04; 95% CI: 1.001, 1.070). The effect of temperature on birthweight was primarily seen at higher PM2.5 levels. There were no statistically significant associations between temperature exposure with low birth weight. CONCLUSIONS: Exposition to maximum temperature was associated with lower birth weight and z-score weight-for-gestational-age and higher risk of preterm birth, in accordance with much of the literature. The effects on birth weight were seen only in the third trimester.

Facile Determination of COVID-19 Seroconversion via Nonradiative Energy Transfer.

Serological tests are crucial in a pandemic scenario, since they are a valuable tool to spot those citizens with potential immunity, specific regions with herd immunity or particular at-risk populations, as well as acquired immunity after vaccination. Hence, high-throughput, fast, cost-effective, and straightforward technologies facilitating interrogation of COVID-19 seroconversion are an existing need. Herein, we developed an innovative assay for the determination of COVID-19 seroconversion. Fluorophore-labeled SARS-CoV-2 spike receptor-binding domain recombinant protein (F-RBD) was discovered to operate as a bioprobe that emits a strong fluorescence upon COVID-19 antibody detection; however, F-RBD fluorescence was deactivated by graphene oxide-decorated surfaces when COVID-19 antibodies are absent in the sample. With a cost of less than 0.5 USD per test (at laboratory scale), the biosensing system offers optimum results within 42 min. To demonstrate that this technology is technically sound in a relevant environment, 34 human serum samples were analyzed and clearly differentiated, requiring a tiny amount of serum (1 µL to be later diluted in saline buffer).

Two Homologues of the Global Regulator Csr/Rsm Redundantly Control Phaseolotoxin Biosynthesis and Virulence in the Plant Pathogen Pseudomonas amygdali pv. phaseolicola 1448A.

The widely conserved Csr/Rsm (carbon storage regulator/repressor of stationary-phase metabolites) post-transcriptional regulatory system controls diverse phenotypes involved in bacterial pathogenicity and virulence. Here we show that Pseudomonas amygdali pv. phaseolicola 1448A contains seven rsm genes, four of which are chromosomal. In RNAseq analyses, only rsmE was thermoregulated, with increased expression at 18 °C, whereas the antagonistic sRNAs rsmX1, rsmX4, rsmX5 and rsmZ showed increased levels at 28 °C. Only double rsmA-rsmE mutants showed significantly altered phenotypes in functional analyses, being impaired for symptom elicitation in bean, including in planta growth, and for induction of the hypersensitive response in tobacco. Double mutants were also non-motile and were compromised for the utilization of different carbon sources. These phenotypes were accompanied by reduced mRNA levels of the type III secretion system regulatory genes hrpL and hrpA, and the flagellin gene, fliC. Biosynthesis of the phytotoxin phaseolotoxin by mutants in rsmA and rsmE was delayed, occurring only in older cultures, indicating that these rsm homologues act as inductors of toxin synthesis. Therefore, genes rsmA and rsmE act redundantly, although with a degree of specialization, to positively regulate diverse phenotypes involved in niche colonization. Additionally, our results suggest the existence of a regulatory molecule different from the Rsm proteins and dependent on the GacS/GacA (global activator of antibiotic and cyanide production) system, which causes the repression of phaseolotoxin biosynthesis at high temperatures.

Microwell plates coated with graphene oxide enable advantageous real-time immunosensing platform.

Immunoassays are fundamental analytical tools in molecular diagnostics, therapy monitoring and drug discovery. Nevertheless, they often take around 6 h and require cumbersome procedures. We introduce a breakthrough in immunosensing based on the photoluminescence quenching capabilities of graphene oxide (GO) and the versatile format offered by the famous microwell plates. Taking advantage of the highly efficient non-radiative energy transfer occurring between photoexcited fluorophores (donors) and GO (acceptor), we discovered that flurophore-labelled antibodies (Fl-Abs) are quickly and strongly quenched by the studied GO-coated microwell, whereas Fl-Abs complexed with the respective analyte are weakly quenched by the same surface due to the low affinity between the GO-coated surface and the relatively long distance between these photoluminescent complexes and the GO-coated surface. In doing so, we developed a conceptually innovative single-step immunosensing platform, avoiding blocking, separation and washing steps and exploiting a single antibody. Importantly, the biosensing response can be interrogated in real time. This leads to an advantageous immunodetection phenomenon which is observable in few minutes (e.g. 5 min). The resulting highly transformative biosensing platform operates with different photoluminescent agents and different analytes. Besides, this biosensing platform was demonstrated to operate with real samples of human urine doped with different concentrations of prostate specific antigen.

[Bioethics and environmental justice in the health of the Andean residents of Peru]. / Bioética y justicia ambiental en la salud de los pobladores andinos de Perú.

This article attempts to capture the bioethical-environmental panorama of the health in the residents who live on the Peruvian highlands, highlighting the inequity in access to health services that exist in this region and reflecting on the possible historical and current contextual causes that have originated differences between Inca-Andean settler and modern-Andean settler. The change in the view of the world about the environment and natural resources, the decline of justice approach, loss of solidarity, welfare, and respect to human being and nature. Besides, we describe health from a historical scenario of this region, where Public health has and will have as a challenge the application of programs that respond to the specific needs of this population, with a focus on the environment.

Time-to-event analysis to evaluate dormancy status of single-bud cuttings: an example for grapevines.

BACKGROUND: The reduced growth of plants during the winter causes a lack in the perceptibility of the phenological events making challenging the study of dormancy. For deciduous crops, dormancy is generally determined by evaluating budbreak of single-node cuttings that are exposed to conditions suitable for growth. However, the absence of a statistical basis for analyzing and interpreting the budbreak behavior evaluated as the percent budbreak, the average time to budbreak and the time to reach 50% budbreak, has caused inconsistent and contradictory criteria to identify the dormancy status of different deciduous crops. RESULTS: In this study, a method was developed to analyze the duration between sampling and budbreak of single-node cuttings and to estimate the dormancy status for grapevines (Vitis vinifera L.) based on the time-to-event distribution of the observations. This method estimates the probability curve of budbreak for each sample and classifies each curve into paradormancy, endodormancy, and ecodormancy according to the significance when compared to a sample curve estimated from cuttings collected during paradormancy and referred to as "reference." CONCLUSION: The approach described in this study provided a comparison of the budbreak distribution of cuttings collected during distinct phases with a confidence of 95%. It also allowed the estimation of the date of occurrence of the dormancy stages for two grapevine cultivars 'Cabernet Sauvignon' and 'Chardonnay,' based on the variability within the sampling season rather than on fixed arbitrary criteria. This approach can also be used to analyze budbreak data of single-node cuttings from other common deciduous crops.