Feasibility and Safety of Percutaneous Kidney Biopsy in Small Kidneys: Breaking the Paradigm.

INTRODUCTION: The percutaneous kidney biopsy (PKB) is an essential tool in nephrology, small kidney size has been a relative contraindication to PKB and there is limited data on the safety and utility of performing PKB in this setting. Our aim was to describe the complications of PKB in small kidneys and to assess if kidney biopsy results have an impact on medical decisions and outcomes. METHODS: This was a retrospective, descriptive, and observational study. Patients older than 16 years of age with a decreased kidney size (≤ 8 cm), and undergoing PKB of native kidneys from July 2019 to December 2022 were included. RESULTS: Twenty-five patients were included, 19 women and 6 men. The mean age was 42.3 ± 18.04. The mean kidney length was 7.56 ±0.33 and the mean width was 4.2 cm. All patients received only one puncture, obtaining an average of 12 glomeruli. The mean BUN and serum creatinine were 36 mg/dl and 1.94 mg/dl, respectively and the mean Hgb (hemoglobin) was 12.87 ±2.81g/dL. Minor complications occurred in 5 patients, perirenal hematoma in 3 patients, hematuria in 1 patient, and hematoma plus hematuria in 1 patient. Histological examination showed FSGS, lupus nephritis, other Glomerular disease (GD), crescentic glomerulonephritis (GN), and tubulointerstitial nephritis in 36%, 20%, 16%, 16%, and 12% of the cases, respectively. Biopsy resulted in management modification in 64% of cases. In a bivariate analysis, kidney size was not associated with higher complication rates. CONCLUSIONS: Percutaneous kidney biopsy in small kidneys is a feasible and safe procedure when properly planned, providing an adequate sample in all cases, with an insignificant number of minor complications, and that is clinically relevant.

Genetic analyses verify sexually mature escaped farmed Atlantic cod and farmed cod eggs in the natural environment.

Elucidating the effects of domesticated organisms escaping into the natural environment represents a topic of importance in both evolutionary and conservation biology. However, when excluding the abundant data on salmonids, there is a lack of knowledge on this topic for marine fish aquaculture, which continues to expand globally. In order to bridge this empirical gap, we investigated a suspected escape of sexually mature domesticated Atlantic cod from a commercial marine fish farm in northern Norway. This involved genotyping samples of fish from cages on the farm, putatively identified escapees and wild cod captured in the region and samples of recently spawned eggs collected in the sea. Genetic analyses confirmed a farmed ancestry of the suspected escapees, and significantly, 27% of the sampled cod eggs. Furthermore, statistical analyses revealed a strong reduction in genetic variation in all samples of the farmed cod, including low effective population size and high degree of siblingship. These results thus document the escape of sexually mature adult cod and the release of fertilized domesticated cod eggs into the natural environment. Although it is possible that some of the mature escapees spawned post-escape, the fact that only a single egg of potential hybrid farmed × wild origin was identified, together with the high number of mature cod in the farm, points to within cage spawning as the primary source of these eggs. This suggestion is supported by oceanic particle-drift modelling, verifying that transport of eggs between the farm and the egg sampling locations was plausible. This study represents a rare documentation of interaction between domesticated and wild populations for a marine fish, pointing towards potential impacts on the local wild population.

Underlying Mechanisms and Treatment of Hypertension in Glomerular Diseases.

PURPOSE OF REVIEW: This review aims to explore the underlying mechanisms that lead to hypertension in glomerular diseases and the advancements in treatment strategies and to provide clinicians with valuable insights into the pathophysiological mechanisms and evidence-based therapeutic approaches for managing hypertension in patients with glomerular diseases. RECENT FINDINGS: In recent years, there have been remarkable advancements in our understanding of the immune and non-immune mechanisms that are involved in the pathogenesis of hypertension in glomerular diseases. Furthermore, this review will encompass the latest data on management strategies, including RAAS inhibition, endothelin receptor blockers, SGLT2 inhibitors, and immune-based therapies. Hypertension (HTN) and cardiovascular diseases are leading causes of mortality in glomerular diseases. The latter are intricately related with hypertension and share common pathophysiological mechanisms. Hypertension in glomerular disease represents a complex and multifaceted interplay between kidney dysfunction, immune-mediated, and non-immune-mediated pathology. Understanding the complex mechanisms involved in this relationship has evolved significantly over the years, shedding light on the pathophysiological processes underlying the development and progression of glomerular disease-associated HTN, and is crucial for developing effective therapeutic strategies and improving patients' outcomes.

Modified pectin with anticancer activity in breast cancer: A systematic review.

Breast cancer is the most commonly diagnosed cancer among women worldwide. The current pharmacological treatments for breast cancer have numerous adverse effects and are not always effective. Recently, the anticancer activity of modified pectins (MPs) against various types of cancers, including breast cancer, has been investigated. This systematic review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) model, including scientific articles from the last 22 years that measured the anticancer activity of MPs on breast cancer. The articles were searched in four databases with the terms: "modified pectin" and "breast cancer". Nine articles were included, five in vitro and four mixed (in vitro and in vivo). Different models and methods by which anticancer activity was measured were analyzed. All the studies reported positive results in both cell lines and in vivo murine models of breast cancer. The extracted data suggest a positive effect and provide mechanistic evidence of MPs in the treatment of breast cancer. However, as limited number of studies were included, further in vivo studies are required to obtain more conclusive preclinical evidence.

Influence of Topography and Composition of Commercial Titanium Dental Implants on Cell Adhesion of Human Gingiva-Derived Mesenchymal Stem Cells: An In Vitro Study.

The topography and composition of dental implant surfaces directly impact mesenchymal cell adhesion, proliferation, and differentiation, crucial aspects of achieving osseointegration. However, cell adhesion to biomaterials is considered a key step that drives cell proliferation and differentiation. The aim of this study was to characterize characterize the topography and composition of commercial titanium dental implants manufactured with different surface treatments (two sandblasted/acid-etched (SLA) (INNO Implants, Busan, Republic of Korea; BioHorizonsTM, Oceanside, CA, USA) and two calcium phosphate (CaP) treated (Biounite®, Berazategui, Argentina; Zimmer Biomet, Inc., Warsaw, IN, USA)) and to investigate their influence on the process of cell adhesion in vitro. A smooth surface implant (Zimmer Biomet, Inc.) was used as a control. For that, high-resolution methodologies such as scanning electron microscopy (SEM), X-ray dispersive spectroscopy (EDX), laser scanning confocal microscopy (LSCM), and atomic force microscopy (AFM) were employed. Protein adsorption and retromolar gingival mesenchymal stem cells (GMSCs) adhesion to the implant surfaces were evaluated after 48 h. The adherent cells were examined by SEM and LSCM for morphologic and quantitative analyses. ANOVA and Tukey tests (α = 0.05) were employed to determine statistical significance. SEM revealed that INNO, BioHorizonsTM, and Zimmer implants have an irregular surface, whereas Biounite® has a regular topography consisting of an ordered pattern. EDX confirmed a calcium and phosphate layer on the Biounite® and Zimmer surfaces, and AFM exhibited different roughness parameters. Protein adsorption and cell adhesion were detected on all the implant surfaces studied. However, the Biounite® implant with CaP and regular topography showed the highest protein adsorption capacity and density of adherent GMSCs. Although the Zimmer implant also had a CaP treatment, protein and cell adhesion levels were lower than those observed with Biounite®. Our findings indicated that the surface regularity of the implants is a more determinant factor in the cell adhesion process than the CaP treatment. A regular, nanostructured, hydrophilic, and moderately rough topography generates a higher protein adsorption capacity and thus promotes more efficient cell adhesion.

Terahertz photodiode integration with multi-octave-bandwidth dielectric rod waveguide probe.

Photonic integrated circuits play a vital role in enabling terahertz (THz) applications that require multi-octave bandwidth. Prior research has been limited in bandwidth due to rectangular waveguide (WRs) interconnects, which can only support single octave at low loss. To overcome this fundamental limitation, we exploit the ultra-wideband (UWB) near-field coupling between planar waveguides and silicon (Si)-based subwavelength dielectric rod waveguides (DRWs) to interconnect THz bandwidth uni-traveling-carrier photodiodes (UTC-PDs) at 0.08-1.03 THz. In a proof-of-concept experiment, the on-chip integrated UTC-PDs demonstrate a UWB operation from 0.1 THz to 0.4 THz. Furthermore, by employing Si DRWs as probes, multi-octave device-under-test characterization of UTC-PDs integrated with UWB transition is enabled with only one DRW probe. The proposed UWB interconnect technology is distinct from previously used WR-based ground-signal-ground probes or quasi-optical free-space coupling since it can provide multi-octave bandwidth and enable on-chip THz circuit integration.

Nasogastric versus nasojejunal tube feeding for severe acute pancreatitis: A systematic review of randomized controlled trials.

Early enteral nutrition through a feeding tube is essential for the management of severe acute pancreatitis (SAP). Nasojejunal tube nutrition has been preferred on the assumption that it provided pancreatic rest in comparison to the nasogastric tube. However, nasojejunal tube placement is complex, may delay feeding initiation and can increase hospital costs. Our aim was to compare the efficacy and safety of enteral feeding with a nasogastric tube versus nasojejunal tube in patients with SAP. We searched four databases (PubMed, Web of Science, Scopus, and Embase) until December 1, 2022. We included randomized controlled trials (RCTs) comparing enteral feeding by nasogastric and nasojejunal tubes in patients with SAP. Primary outcome was all-cause mortality. Secondary outcomes were organ failure, infection, complications, surgical intervention, duration of tube feeding and length of hospital stay. Risk of bias assessment was completed independently by two investigators using the Cochrane RoB 2.0 tool. We performed random effects model meta-analyses using the inverse variance method. Effect measures were reported as relative risks (RR) and their 95% CIs for dichotomous outcomes and mean differences (MD) and their 95% CIs for continuous outcomes. We included four RCTs involving 192 patients with SAP. The mean ages ranged between 36 and 62 years old. There was no significant difference in all-cause mortality between the nasogastric and nasojejunal feeding arms (18/98 vs. 23/93; RR 1.34, 95%CI 0.77-2.30; p=0.30). There were no significant differences in all secondary outcomes between feeding arms. There were three RCTs with some concerns of bias, in the randomization process. In conclusion, in patients with SAP, enteral feeding delivered by nasogastric tube was as efficacious and safe as nasojejunal tube. Further randomized controlled trials with more participants and better design are needed to confirm these findings.

Sub-oclusión intestinal y desnutrición severa en esclerosis sistémica sin esclerodermia

La esclerosis sistémica sin escleroderma es una forma no común de compromiso sistémico de esta enfermedad, con ausencia de manifestaciones cutáneas. Presentamos el caso de una mujer de 71 años con índice de masa corporal (IMC) en 16,9 kg/m2, con historia de hipotiroidismo y estreñimiento crónico, quien acude a emergencia por dolor y distensión abdominal, asociado a náuseas. Se realizó una tomografía abdomino-pélvica encontrándose cámara gástrica colapsada, asas intestinales con algunos segmentos distendidos, con signos de fecalización de asa delgada. La colonoscopía describió dolicocolon severo. Se observaron placas induradas en codo derecho y en ambos glúteos. Los exámenes auxiliares: ANA 1/640 patrón centromérico, anticuerpos anticentrómero = 227 U/mL (valor normal - VN: 0-25), Anti SCL-70 = 1,9 U/mL (VN 0-25) y anti RNP = 0,1 U/mL (VN 0-25). La capilaroscopía de borde ungueal a 200x mostró megacapilares. El diagnóstico clínico fue esclerosis sistémica sin esclerodermia. Se inició tratamiento con dieta rica en fibra y nutrición parenteral por 1 semana. La evolución de la paciente fue favorable.

Systemic sclerosis sine Scleroderma is an uncommon form of systemic compromise of this disease, in the abscense of cutaneous manifestations. We present the case of a 71 years-old woman, body mass index (BMI) in 16.9 kg/m2, with history of hypothyroidism and chronic constipation, who goes to the emergency with pain, abdominal bloating, and nausea. An abdominopelvic tomography was made, reporting a collapse of the gastric chamber, some segments of intestinal loops distended with signs of fecalization in the small intestine. A colonoscopy described severe dolicocolon. We observed indurated plaques in left elbow and in both buttocks. Lab tests: ANA 1/640 with anticentromeric pattern, anticentromere antibodies = 227 U/mL (0-25), Anti-SCL-70 = 1.9 U/mL (0-25), anti-RNP = 0.1 U/mL (0-25). Peri-ungueal cappilaroscopy 200x showed mega capillaries. Clinical diagnosis was systemic sclerosis sine scleroderma. We initiated treatment with a high-fiber diet and parenteral nutrition for a week. The patient evolution was favorable.

Aquaculture-driven evolution of the salmon louse mtDNA genome.

Resistance toward the antiparasitic pyrethroid, deltamethrin, is reported in the Atlantic salmon louse (Lepeophtheirus salmonis salmonis), a persistent ectoparasite of farmed and wild salmonids. The resistance mechanism is linked to mitochondrial DNA (mtDNA), where genetic markers for resistance have been identified. Here, we investigated how widespread pyrethroid use in aquaculture may have influenced mtDNA variation in lice, and the dispersion of resistant haplotypes across the North Atlantic, using historical (2000-2002 "pre-resistance") and contemporary (2014-2017 "post-resistance") samples. To study this, we sequenced ATPase 6 and cytochrome b, genotyped two genetic markers for deltamethrin resistance, and genotyped microsatellites as "neutral" controls of potential population bottlenecks. Overall, we observed a modest reduction in mtDNA diversity in the period 2000-2017, but no reduction in microsatellite variation was observed. The reduction in mtDNA variation was especially distinct in two of the contemporary samples, fixed for one and two haplotypes, respectively. By contrast, all historical samples consisted of close to one mtDNA haplotype per individual. No population genetic structure was detected among the historical samples for mtDNA nor microsatellites. By contrast, significant population genetic differentiation was observed for mtDNA among some of the contemporary samples. However, the observed population genetic structure was tightly linked with the pattern of deltamethrin resistance, and we therefore conclude that it primarily reflects the transient mosaic of pyrethroid usage in time and space. Two historically undetected mtDNA haplotypes dominated in the contemporary samples, both of which were linked to deltamethrin resistance, demonstrating primarily two origins of deltamethrin resistance in the North Atlantic. Collectively, these data demonstrate that the widespread use of pyrethroids in commercial aquaculture has substantially altered the patterns of mtDNA diversity in lice across the North Atlantic, and that long-distance dispersion of resistance is rapid due to high level of genetic connectivity that is observed in this species.

Nasogastric versus nasojejunal tube feeding for severe acutepancreatitis: A systematic review of randomized controlled trials

Early enteral nutrition through a feeding tube is essential for the management of severe acute pancreatitis (SAP). Nasojejunal tube nutrition has been preferred on the assumption that it provided pancreatic rest in comparison to the nasogastric tube. However, nasojejunal tube placement is complex, may delay feeding initiation and can increase hospital costs. Our aim was to compare the efficacy and safety of enteral feeding with a nasogastric tube versus nasojejunal tube in patients with SAP. We searched four databases (PubMed, Web of Science, Scopus, and Embase) until December 1, 2022. We included randomized controlled trials (RCTs) comparing enteral feeding by nasogastric and nasojejunal tubes in patients with SAP. Primary outcome was all-cause mortality. Secondary outcomes were organ failure, infection, complications, surgical intervention, duration of tube feeding and length of hospital stay. Risk of bias assessment was completed independently by two investigators using the Cochrane RoB 2.0 tool. We performed random effects model meta-analyses using the inverse variance method. Effect measures were reported as relative risks (RR) and their 95% CIs for dichotomous outcomes and mean differences (MD) and their 95% CIs for continuous outcomes. We included four RCTs involving 192 patients with SAP. The mean ages ranged between 36 and 62 years old. There was no significant difference in all-cause mortality between the nasogastric and nasojejunal feeding arms (18/98 vs. 23/93; RR 1.34, 95%CI 0.77-2.30; p=0.30). There were no significant differences in all secondary outcomes between feeding arms. There were three RCTs with some concerns of bias, in the randomization process. In conclusion, in patients with SAP, enteral feeding delivered by nasogastric tube was as efficacious and safe as nasojejunal tube. Further randomized controlled trials with more participants and better design are needed to confirm these findings.

La nutrición enteral temprana a través de una sonda de alimentación es esencial para el tratamiento de la pancreatitis aguda severa (PAS). Se ha preferido la nutrición por sonda nasoyeyunal, bajo el supuesto de que proporciona descanso pancreático en comparación con la sonda nasogástrica. Sin embargo, la colocación de la sonda nasoyeyunal es compleja, puede retrasar el inicio de la alimentación y aumentar los costos hospitalarios. Nuestro objetivo fue comparar la eficacia y seguridad de la alimentación enteral con sonda nasogástrica versus sonda nasoyeyunal en pacientes con PAS. Se realizaron búsquedas en cuatro bases de datos (PubMed, Web of Science, Scopus y Embase) hasta el 1 de diciembre de 2022. Se incluyeron ensayos controlados aleatorios (ECA) que compararon la alimentación enteral mediante sondas nasogástricas y nasoyeyunales en pacientes con PAS. El resultado primario fue la mortalidad por todas las causas. Los resultados secundarios fueron insuficiencia orgánica, infección, complicaciones, intervención quirúrgica, duración de la alimentación por sonda y duración de la estancia hospitalaria. Dos investigadores completaron de forma independiente la evaluación del riesgo de sesgo mediante la herramienta Cochrane RoB 2.0. Realizamos metanálisis de modelos de efectos aleatorios utilizando el método de varianza inversa. Las medidas del efecto se informaron como riesgos relativos (RR) y sus IC del 95% para resultados dicotómicos y diferencias de medias (DM) y sus IC del 95% para resultados continuos. Se incluyeron cuatro ECA con 192 pacientes con PAS. La edad media osciló entre 36 y 62 años. No hubo diferencias significativas en la mortalidad por todas las causas entre los brazos de alimentación nasogástrica y nasoyeyunal Cambiar lo resaltado por: (18/98 vs. 23/93; RR 1.34, 95%CI 0.77-2.30; p=0.30). No hubo diferencias significativas en todos los resultados secundarios entre los brazos de alimentación. Hubo tres ECA con algunas preocupaciones de sesgo en el proceso de asignación aleatorizado. En conclusión, en pacientes con PAS, la alimentación enteral administrada por sonda nasogástrica fue tan eficaz y segura como la sonda nasoyeyunal. Se necesitan más ensayos controlados aleatorios con más participantes y mejor diseño para confirmar estos hallazgos.

Polarimetric imaging for the detection of synthetic models of SARS-CoV-2: A proof of concept.

Objective: To conduct a proof-of-concept study of the detection of two synthetic models of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) using polarimetric imaging. Approach: Two SARS-CoV-2 models were prepared as engineered lentiviruses pseudotyped with the G protein of the vesicular stomatitis virus, and with the characteristic Spike protein of SARS-CoV-2. Samples were prepared in two biofluids (saline solution and artificial saliva), in four concentrations, and deposited as 5-µL droplets on a supporting plate. The angles of maximal degree of linear polarization (DLP) of light diffusely scattered from dry residues were determined using Mueller polarimetry from87 samples at 405 nm and 514 nm. A polarimetric camera was used for imaging several samples under 380-420 nm illumination at angles similar to those of maximal DLP. Per-pixel image analysis included quantification and combination of polarization feature descriptors in 475 samples. Main results: The angles (from sample surface) of maximal DLP were 3° for 405 nm and 6° for 514 nm. Similar viral particles that differed only in the characteristic spike protein of the SARS-CoV-2, their corresponding negative controls, fluids, and the sample holder were discerned at 10-degree and 15-degree configurations. Significance: Polarimetric imaging in the visible spectrum may help improve fast, non-contact detection and identification of viral particles, and/or other microbes such as tuberculosis, in multiple dry fluid samples simultaneously, particularly when combined with other imaging modalities. Further analysis including realistic concentrations of real SARS-CoV-2 viral particles in relevant human fluids is required. Polarimetric imaging under visible light may contribute to a fast, cost-effective screening of SARS-CoV-2 and other pathogens when combined with other imaging modalities.

Contactless Ultrasonic Cavitation for the Prevention of Shunt Obstruction in Hydrocephalus: A Proof-of-Concept Study.

BACKGROUND: Obstructive failure of implanted shunts is the most common complication in the treatment of hydrocephalus. Biological material and debris accumulate in the inner walls of the valve and catheters block the normal flow of the drained cerebrospinal fluid causing severe symptoms with high morbidity and mortality. Unfortunately, at present, there is no effective preventive protocol or cleaning procedure available. OBJECTIVE: To assess whether externally applied, focused ultrasound beams can be used to resuspend deposits accumulated in brain shunts safely. METHODS: A computational model of an implanted brain shunt was implemented to test the initial design parameters of a system comprising several ultrasound transducers. Under laboratory conditions, configurations with 3 and 4 transducers were arranged in a triangle and square pattern with their radiation axis directed towards a target model of the device, 2 catheters and a brain shunt filled with water and deposited graphite powder. The ultrasound beams were then concentrated on the device across a head model. RESULTS: The computational model revealed that by using only 3 transducers, the acoustic field intensity on the valve was approximately twice that on the brain surface suggesting that acoustic cavitation could be selectively achieved. Resuspension of graphite deposits inside the catheters and the valve were then physically demonstrated and video-recorded with no temperature increase. CONCLUSION: The technology presented here has the potential to be used routinely as a noninvasive, preventive cleaning procedure to reduce the likelihood of obstruction-related events in patients with hydrocephalus treated with an implanted shunt.

Implications of Neural Plasticity in Retinal Prosthesis.

Retinal degenerative diseases such as retinitis pigmentosa cause a progressive loss of photoreceptors that eventually prevents the affected person from perceiving visual sensations. The absence of a visual input produces a neural rewiring cascade that propagates along the visual system. This remodeling occurs first within the retina. Then, subsequent neuroplastic changes take place at higher visual centers in the brain, produced by either the abnormal neural encoding of the visual inputs delivered by the diseased retina or as the result of an adaptation to visual deprivation. While retinal implants can activate the surviving retinal neurons by delivering electric current, the unselective activation patterns of the different neural populations that exist in the retinal layers differ substantially from those in physiologic vision. Therefore, artificially induced neural patterns are being delivered to a brain that has already undergone important neural reconnections. Whether or not the modulation of this neural rewiring can improve the performance for retinal prostheses remains a critical question whose answer may be the enabler of improved functional artificial vision and more personalized neurorehabilitation strategies.

Cross-modal activation of the primary visual cortex by auditory stimulation in RCS rats: considerations in visual prosthesis.

An important brain re-wiring, the so-called cross-modal plasticity, occurs during progression of retinal degenerative diseases to compensate for lack of visual input. The visual cortex does not go 'unused', instead it is devoted to processing other sensory modalities. In this study we recorded, in the visual cortex, visual- and auditory-evoked potentials in an anesthetized murine model of retinal degeneration. The latency to the first peak of the recorded local field potentials was used to assess the speed of the response. Visual responses occurred significantly faster in the control group. Conversely, auditory responses appeared significantly faster in animals with retinal degeneration. This suggests the compensatory neural rewiring is optimizing the performance of other sensory modalities, hearing in this case. This phenomenon may play an important role in visual neuro-rehabilitation. Whether or not it can promote or deter the interpretation of artificially encoded neural signals from a visual prosthesis remains to be studied.

Time-Slotted Spreading Factor Hopping for Mitigating Blind Spots in LoRa-Based Networks.

It has been demonstrated that LoRa-based wide area networks (WANs) can cover extended areas under harsh propagation conditions. Traditional LoRaWAN solutions based on single-hop access face important drawbacks related to the presence of blind spots. This paper aims to tackle blind spots and performance issues by using a relaying approach. Many researchers investigating multi-hop solutions consider a fixed spreading factor (SF). This simplifies synchronization and association processes, but does not take advantage of the orthogonality between the virtual channels (i.e., frequency, SF) that help to mitigate blind spots. This paper proposes a time-slotted spreading factor hopping (TSSFH) mechanism that combines virtual channels and time slots into a frame structure. Pseudo-random scheduling is used inside blind spots, which simplifies the end-devices' communication process and network organization. The results show how collisions decrease inside blind spots when more communication opportunities become available as more relaying nodes can be listening in different cells (i.e., frequency, SF-offset, time-offset). This has a direct impact on the collision-free packet delivery ratio (PDR) metric, which improves when more listening windows are opened, at the expense of faster battery depletion.

Optical imaging spectroscopy for rapid, primary screening of SARS-CoV-2: a proof of concept.

Effective testing is essential to control the coronavirus disease 2019 (COVID-19) transmission. Here we report a-proof-of-concept study on hyperspectral image analysis in the visible and near-infrared range for primary screening at the point-of-care of SARS-CoV-2. We apply spectral feature descriptors, partial least square-discriminant analysis, and artificial intelligence to extract information from optical diffuse reflectance measurements from 5 µL fluid samples at pixel, droplet, and patient levels. We discern preparations of engineered lentiviral particles pseudotyped with the spike protein of the SARS-CoV-2 from those with the G protein of the vesicular stomatitis virus in saline solution and artificial saliva. We report a quantitative analysis of 72 samples of nasopharyngeal exudate in a range of SARS-CoV-2 viral loads, and a descriptive study of another 32 fresh human saliva samples. Sensitivity for classification of exudates was 100% with peak specificity of 87.5% for discernment from PCR-negative but symptomatic cases. Proposed technology is reagent-free, fast, and scalable, and could substantially reduce the number of molecular tests currently required for COVID-19 mass screening strategies even in resource-limited settings.

Generation and persistence of S1 IgG and neutralizing antibodies in post-COVID-19 patients.

BACKGROUND: Antibody-mediated immune response plays an important role in protection against reinfection. In the case of SARS-CoV-2 infection, the maximum duration of antibody response is still unknown. In this work, the generation of neutralizing  antibodies (NAbs) and IgG antibodies against the S1 subunit (S1 IgG ) of SARS-CoV-2 and their possible duration were determined through decay models. METHODS: 132 participants with SARS-CoV-2 infection were classified according to the severity of the disease. Seroconversion and persistence of S1 IgG antibodies and NAbs were determined by ELISA, samples were taken at two different times post-infection and duration of those antibodies was estimated using Linear Mixed Models (LMMs). RESULTS: The highest amount of S1 IgGs antibodies was associated with age (41 years or older), greater severity of COVID-19 and male gender. NAbs production was associated with the same variables, except for age. The percentage of NAbs decay is higher in the asymptomatic group (P = 0.033), while in S1 IgG antibodies decay, no statistical difference was found between the 4 severity groups. An exponential decay model was built by using a LMM and similarly, two dispersion regions where constructed. The duration of S1 IgG antibodies was 744 days (668-781) for first region and 744 days (453-1231) for the second. Regarding NAbs, an adaptative LMM was used to model a logistic function, determining a duration of 267 days (215-347). CONCLUSION: Humoral immunity to SARS-CoV-2 infection depends on the severity of the disease, gender and age. This immune response could be long-lasting as for other coronaviruses.

Advances in the eradication of foot-and-mouth disease in South America: 2011-2020.

For more than 70 years, the countries of South America have been attempting to eliminate foot-and-mouth disease (FMD), but a regional strategy had not been established by all the affected countries until 1988. The Action Plan 1988-2009 of the Hemispheric Program for the Eradication of Foot-and-Mouth Disease (PHEFA 1988-2009) resulted in an FMD-free status in 88.4% of the bovine population of South America. However, countries of the Andean sub-region maintained an FMD endemic. In addition, sporadic outbreaks in vaccinated cattle populations have been reported in countries of the Southern Cone, endangering the disease-free status in these countries. Within this context, the PHEFA 2011-2020 was approved to eliminate FMD from the subcontinent, and this review describes the most important milestones during its execution. FMD in Ecuador and sporadic outbreaks in the Southern Cone sub-region were effectively eliminated. The outbreaks that occurred in Colombia in 2017 and 2018 were successfully controlled. The type C virus was removed from the vaccines in use in most countries, based on a risk assessment. This review also describes the progress made by the countries advancing toward official recognition as FMD-free in all their territories, with Bolivia, Brazil, and Peru leading the progressive suspension of vaccination to achieve FMD-free status without vaccination. Consequently, at the end of PHEFA 2011-2020, Venezuela was, and still is, the only country in the region whose control program has suffered setbacks, and no evidence has suggested that the transmission and infection of the bovine population have been eliminated. At the end of 2020, a new PHEFA Action Plan 2021-2025 was approved with a five-year horizon, to complete the eradication of the disease in the Americas.