Potential uses of silkworm pupae (Bombyx mori L.) in food, feed, and other industries: a systematic review.

The increasing pressures imposed on ecosystems by the growing needs of the human population are stimulus for research into innovative and unconventional sources of raw materials for different industries. This systematic review was carried out to investigate the available literature on the possible industrial uses of silkworm (Bombyx mori L.) pupae, a residue of silk production. The review was conducted using an adapted version of PRISMA. After a screening process, 105 articles were obtained and subjected to a detailed quantitative and qualitative analysis. It was found that in the last decade there has been a significant increase in the number of papers devoted to the study of the potential use of silkworm pupae in different applications, with a significantly higher number in the last three years of the scope of this review, indicating a growing interest in the subject. From the analysis of the information collected, promising uses in human and animal food, such as fish, mammalian, poultry, swine and companion animals, as well as potential uses for the pharmaceutical industry, were identified. The evaluated research identified compounds with antioxidant activity and important contents of unsaturated fatty acids, which are related to beneficial effects on cardiovascular health, diabetes control, reduction of the risk of developing certain types of cancer and inflammatory activity, among other benefits. One of the most relevant findings is that many studies report a significant concentration of α-linolenic acid in silkworm pupae oil, which is attributed with anticancer, anti-inflammatory, antioxidant, anti-obesity and neuroprotective properties, among others.

A Comprehensive Review of Silver and Gold Nanoparticles as Effective Antibacterial Agents.

The increasing threat from antibiotic-resistant bacteria has necessitated the development of novel methods to counter bacterial infections. In this context, the application of metallic nanoparticles (NPs), especially gold (Au) and silver (Ag), has emerged as a promising strategy due to their remarkable antibacterial properties. This review examines research published between 2006 and 2023, focusing on leading journals in nanotechnology, materials science, and biomedical research. The primary applications explored are the efficacy of Ag and Au NPs as antibacterial agents, their synthesis methods, morphological properties, and mechanisms of action. An extensive review of the literature on NPs synthesis, morphology, minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and effectiveness against various Gram(+/-) bacteria confirms the antibacterial efficacy of Au and Ag NPs. The synthesis methods and characteristics of NPs, such as size, shape, and surface charge, are crucial in determining their antibacterial activity, as these factors influence their interactions with bacterial cells. Furthermore, this review underscores the urgent necessity of standardizing synthesis techniques, MICs, and reporting protocols to enhance the comparability and reproducibility of future studies. Standardization is essential for ensuring the reliability of research findings and accelerating the clinical application of NP-based antimicrobial approaches. This review aims to propel NP-based antimicrobial strategies by elucidating the properties that enhance the antibacterial activity of Ag and Au NPs. By highlighting their inhibitory effects against various bacterial strains and relatively low cytotoxicity, this work positions Ag and Au NPs as promising materials for developing antibacterial agents, making a significant contribution to global efforts to combat antibiotic-resistant pathogens.

Use of Residual Malt from an Artisanal Beer Brewing Process in the Biosynthesis of Silver Nanoparticles Mediated by Nucleating and Structure-Directing Agents.

Biosynthesized silver nanoparticles (AgNPs) are widely used in varied applications, which are morphology dependent. Consequently, a morphology-controlled synthesis is mandatory. Although there are several studies focused on the plant extract-based biosynthesis of metallic nanoparticles, the use of extracts obtained from agro-wastes is scant. Furthermore, information regarding morphology modification through the use of additional agents is even more scarce. Thus, in this study, AgNPs were synthesized using a malt extract (ME) obtained from an artisanal beer brewing process residue. Additionally, sodium chloride (NaCl), gum arabic (GA), and talc (T) were used in an attempt to modify the morphology of AgNPs. XRD, DLS, SEM, and TEM results demonstrate that stable AgNPs of different sizes and shapes were synthesized. FTIR, HPLC analysis, and the quantification of total proteins, free amino acids, reducing sugars, and total polyphenols before and after AgNPs synthesis showed that ME biomolecules allowed them to act as a source of reducing and stabilizing agents. Therefore, this study provides evidence that ME can be successfully used to biosynthesize AgNPs. Additionally, the antibacterial activity of AgNPs against Gram-negative and Gram-positive bacteria was evaluated. Results indicate that AgNPs show a higher antibacterial activity against Gram-positive bacteria.

Banco de donantes voluntarios de células progenitoras hematopoyéticas. Proyecto Panama Dono

Introducción; El Trasplante de Células Progenitoras Hematopoyéticas es actualmente un tratamiento para diferentes desordenes hematológicos malignos y no malignos, que se efectúa cuando existe un receptor con un donante idéntico o haploidéntico para los genes del Complejo Mayor de Histocompatibilidad. En ausencia de donante familiar compatible, hemos creado el Programa de Donantes Voluntarios con tipificación del Sistema HLA. que han expresado su consentimiento de ser donantes y comparten los alelos del Sistema de linfocitos humanos codificados en el brazo corto del cromosoma seis. Materiales y métodos: El presente estudio es un estudio descriptivo, observacional y transversal que presenta los resultados de la búsqueda de donantes voluntarios para receptores sin donante familiar en el Programa Panamá Dono y su aplicación en Panamá. Resultado: De los grupos familiares estudiados que incluye receptor y donantes familiares, un total de 783 personas estudiadas aceptaron voluntariamente ser donantes no relacionados y sus tipificaciones HLA incorporadas al Programa Panamá Dono. Un total de 321 pacientes sin donante idéntico o haploidentico en su grupo familiar, se les ha buscado donante no relacionado en el Programa y se logró Trasplantar el primer receptor con un donante voluntario compatible en 16 genes del Complejo Mayor de Histocompatibilidad en el Hospital del Niño. Conclusión: El Laboratorio Nacional de Trasplante de la Caja de Seguro Social ha logrado crear el Programa de Donantes Voluntarios de Células Progenitoras Hematopoyéticas denominado PANAMA DONO, que consta de 788 panameños que han expresado su consentimiento. En la actualidad una paciente del Hospital del Niño fue trasplantada en 2022 con esta modalidad de donante compatible no relacionado. La compatibilidad idéntica de la receptora con el donante voluntario fue de 16 alelos idénticos del Complejo Mayor de Histocompatibilidad. (provisto por Infomedic International)

Introduction: Hematopoietic Progenitor Cell Transplantation is currently a treatment for different malignant and non-malignant hematological disorders, which is performed when there is a recipient with an identical or haploidentical donor for the genes of the Major Histocompatibility Complex. In the absence of a compatible family donor, we have created the Volunteer Donor Program with HLA System typing, who have expressed their consent to be donors and share the alleles of the human lymphocyte system encoded on the short arm of chromosome six. Materials and methods: The present study is a descriptive, observational, and cross-sectional study that presents the results of the search for volunteer donors for recipients without a family donor in the Panama Dono Program and its application in Panama. Results: Of the family groups studied, which included recipients and family donors, a total of 783 persons studied voluntarily accepted to be unrelated donors and their HLA typing incorporated into the Panama Dono Program. A total of 321 patients without an identical or haploidentical donor in their family group have been searched for unrelated donors in the Program and the first recipient was transplanted with a voluntary donor compatible in 16 genes of the Major Histocompatibility Complex in the Hospital del Niño. Conclusion: The National Transplant Laboratory of the Social Security Fund has managed to create the Program of Voluntary Donors of Hematopoietic Progenitor Cells called PANAMA DONO, which consists of 788 Panamanians who have expressed their consent. Currently a patient from the Hospital del Niño was transplanted in 2022 with this unrelated compatible donor modality. The identical compatibility of the recipient with the volunteer donor was 16 identical alleles of the Major Histocompatibility Complex. (provided by Infomedic International)

Exploring the Antioxidant Potential of Tragia volubilis L.: Mitigating Chemotherapeutic Effects of Doxorubicin on Tumor Cells.

Several plants of the genus Tragia L. have shown antibacterial, fungicidal, and antiproliferative activity, among other types of activities; however, most species of the genus have not been investigated. Tragia volubilis L. is native to tropical America and Africa, and although it has been reported as medicinal in the literature, it has not been thoroughly investigated. In this study, the phytochemical screening, isolation, and identification of compounds and the determination of the antioxidant activity of the aqueous extract of Tragia volubilis L. and its partitions were carried out. Ethyl acetate and n-butanol partitions of the extract present high antioxidant activity according to the Antioxidant Activity Index. Due to their activity, these partitions were tested on RKO cells as a representative model, both individually and in combination with Doxorubicin. It was found that the partitions significantly reduced the effect of Doxorubicin, as well as the expression of proteins involved in DNA damage and cell death. While the reduction of the chemotherapeutic effect of Doxorubicin on tumor cells may not be a desired outcome in therapeutic settings, the findings of the study are valuable in revealing the antioxidant potential of Tragia volubilis L. and its partitions. This highlights the importance of carefully regulating the application of antioxidants, especially in the context of cancer chemotherapy.

HPLC-UV evaluation of a microwave assisted method as an active drug loading technique for exosome-based drug delivery system.

This paper evaluates the potential of a microwave radiation (MR) assisted method as an active drug loading technique for exosomes using polyphenolic nutraceuticals as model drugs (i.e. resveratrol (RV), rosmarinic acid (RA), pterostilbene (PT) and epigallocatechin gallate (EG)). MR is evaluated as a single step method and as part of a two-step method consisting of incubation (IN) followed by MR. The effect of exposure time, loading method and type of nutraceutical on the loading efficiency were investigated using high performance liquid chromatography (HPLC), X-ray diffraction (XRD) and flow cytometry. Additionally, dynamic light scattering (DLS) was used to determine the size of exosomes. Loading efficiency results indicated that MR is a promising method to be used as loading process. Results also suggested that due to different levels of hydrophobicity, related to the number of OH groups, the absorption of polyphenols into the bilayer of EVs is different for each molecule. According to XRD results, MR could not be used with any cargo drug since radiation could affect the chemical composition and the degree of crystallinity of such molecules, consequently affecting their performance. Flow cytometry results indicated that loading methods negatively affect exosome concentration.

Comparative effect of antihypertensive drugs in improving arterial stiffness in adults with hypertension (RIGIPREV study). A network meta-analysis.

Aims: To synthesize and evaluate the available scientific evidence on the efficacy of antihypertensive drugs on arterial stiffness in patients with hypertension by using a network meta-analysis approach. Methods: A systematic search of the MEDLINE (via PubMed), Scopus, and Web of Science databases was conducted to identify experimental studies addressing the effect of different antihypertensive drugs on arterial stiffness parameters (pulse wave velocity [PWV] and augmentation index [AIx]) in adults with hypertension. Comparative evaluation of the effect of antihypertensive drugs was performed by conducting a standard pairwise meta-analysis and a network meta-analysis for direct and indirect comparisons between antihypertensive drugs and placebo/other antihypertensive drugs. Analyses were performed including studies of any duration and only studies longer than 6 months length. Results: Seventy-six studies were included in the main analysis and considering only studies longer than 6 months length, thiazide diuretics, ACEIs, ARBs, the ACEI/ARB combination, the ACEI/CCB combination, and the ARB/CCB combination showed a higher effect on reducing PWV, and ACEIs and ARBs on reducing AIx. Conclusion: Our research provides evidence that antihypertensive medications are an effective way to treat arterial stiffness in adults with hypertension. Based on our findings, patients with hypertension who have greater levels of arterial stiffness may benefit from using thiazide diuretics, ACEIs, ARBs, the ACEI/ARB combination, the ACEI/CCB combination, and the ARB/CCB combination. Systematic Review Registration: PROSPERO (CRD42021276360).

A Novel Approach to Obtain Vaccine Effectiveness Continuous Profiles. Example Case: COVID-19 in Elderly Mexicans.

Population-wide vaccination is the most promising long-term COVID-19 disease management strategy. However, the protection offered by the currently available COVID-19 vaccines wanes over time, requiring boosters to be periodically given, which represents an unattainable challenge, especially if it is necessary to apply several doses per year. Therefore, it is essential to design strategies that contribute to maximizing the control of the pandemic with the available vaccines. Achieving this objective requires knowing, as precisely and accurately as possible, the changes in vaccine effectiveness over time in each population group, considering the eventual dependence on age, sex, etc. Thus, the present work proposes a novel approach to calculating realistic effectiveness profiles against symptomatic disease. In addition, this strategy can be adapted to estimate realistic effectiveness profiles against hospitalizations or deaths. All such time-dependent profiles allow the design of improved vaccination schedules, where each dose can be administrated to the population groups so that the fulfillment of the containment objectives is maximized. As a practical example for this analysis, vaccination against COVID-19 in Mexico was considered. However, this methodology can be applied to other countries' data or to characterize future vaccines with time-dependent effectiveness values. Since this strategy uses aggregated observational data collected from massive databases, assumptions about the data validity and the course of the studied epidemic could eventually be necessary.

Psychometric Properties of the Multidimensional Assessment of Interoceptive Awareness (MAIA) Questionnaire in Colombian University Students.

INTRODUCTION: The university student population is influenced by multiple factors that affect body awareness. Identifying the body awareness status of students is crucial in creating self-care and emotion management programs to prevent diseases and promote health. The Multidimensional Assessment of Interoceptive Awareness (MAIA) questionnaire evaluates interoceptive body awareness in eight dimensions through 32 questions. It is one of the few tools that enable a comprehensive assessment of interoceptive body awareness by involving eight dimensions of analysis. METHOD: The objective of this study is to present the psychometric properties of the Multidimensional Assessment of Interoceptive Awareness (MAIA) to observe to what extent the hypothesized model fits the population of university students in Colombia. A descriptive cross-sectional study was conducted with 202 students who met the inclusion criterion of being undergraduate university students. Data were collected in May 2022. RESULTS: A descriptive analysis of the sociodemographic variables of age, gender, city, marital status, discipline, and history of chronic diseases was performed. JASP 0.16.4.0 statistical software was used to conduct confirmatory factor analysis. A confirmatory factor analysis was performed based on the proposed eight-factor model of the original MAIA, giving a significant p-value and 95% confidence interval. However, when performing loading factor analysis, a low p-value was found for item 6 of the Not Distracting factor, and for the entire Not Worrying factor. DISCUSSION: A seven-factor model with modifications is proposed. CONCLUSIONS: The results of this study confirmed the validity and reliability of the MAIA in the Colombian university student population.

Association between Feelings of Trust and Security with Subjective Health among Mexican Migrants in the New York City Area.

The size of the foreign-born population living in the United States makes migrants' health a substantive policy issue. The health status of Mexican immigrants might be affected by the level of social capital and the social context, including the rhetoric around immigration. We hypothesize that a diminished perception of trust and safety in the community has a negative impact on self-reported health. In a cross-sectional study, we conducted a survey among 266 Mexican Immigrants in the New York City Area who used the Mexican Consulate between May and June 2019 for regular services provided to documented and undocumented immigrants. A univariate and bivariate descriptive analysis by trust and security items first shows the diversity of the Mexican population living in the US and the conditions of vulnerability. Then, logistic regression models estimate the association between trust and security items with self-reported health status. Results show that safety is consistently associated with good self-rated health, especially when rating the neighborhood, and trust showed mixed results, more reliant to the way it is operationalized. The study illustrates a pathway by which perceptions of the social context are associated with migrants' health.

Potential contributions of the intrinsic retinal oscillations recording using non-invasive electroretinogram to bioelectronics.

Targeted electric signal use for disease diagnostics and treatment is emerging as a healthcare game-changer. Besides arrhythmias, treatment-resistant epilepsy and chronic pain, blindness, and perhaps soon vision loss, could be among the pathologies that benefit from bioelectronic medicine. The electroretinogram (ERG) technique has long demonstrated its role in diagnosing eye diseases and early stages of neurodegenerative diseases. Conspicuously, ERG applications are all based on light-induced responses. However, spontaneous, intrinsic activity also originates in retinal cells. It is a hallmark of degenerated retinas and its alterations accompany obesity and diabetes. To the extent that variables extracted from the resting activity of the retina measured by ERG allow the predictive diagnosis of risk factors for type 2 diabetes. Here, we provided a comparison of the baseline characteristics of intrinsic oscillatory activity recorded by ERGs in mice, rats, and humans, as well as in several rat strains, and explore whether zebrafish exhibit comparable activity. Their pattern was altered in neurodegenerative models including the cuprizone-induced demyelination model in mice as well as in the Royal College of Surgeons (RCS-/-) rats. We also discuss how the study of their properties may pave the way for future research directions and treatment approaches for retinopathies, among others.

Northeast Yucatan hurricane activity during the Maya Classic and Postclassic periods.

The collapse of the Maya civilization in the late 1st/early 2nd millennium CE has been attributed to multiple internal and external causes including overpopulation, increased warfare, and environmental deterioration. Yet the role hurricanes may have played in the fracturing of Maya socio-political networks, site abandonment, and cultural reconfiguration remains unexplored. Here we present a 2200 yearlong hurricane record developed from sediment recovered from a flooded cenote on the northeastern Yucatan peninsula. The sediment archive contains fine grain autogenic carbonate interspersed with anomalous deposits of coarse carbonate material that we interpret as evidence of local hurricane activity. This interpretation is supported by the correlation between the multi-decadal distribution of recent coarse beds and the temporal distribution of modern regional landfalling storms. In total, this record allows us to reconstruct the variable hurricane conditions impacting the northern lowland Maya during the Late Preclassic, Classic, and Postclassic Periods. Strikingly, persistent above-average hurricane frequency between ~ 700 and 1450 CE encompasses the Maya Terminal Classic Phase, the declines of Chichén Itza, Cobá, and subsequent rise and fall of the Mayapán Confederacy. This suggests that hurricanes may have posed an additional environmental stressor necessary of consideration when examining the Postclassic transformation of northern Maya polities.

Influence of Acacia Mearnsii Fodder on Rumen Digestion and Mitigation of Greenhouse Gas Production.

In recent years, the worrying generation of GHG from ruminant production has generated widespread interest in exploring nutritional strategies focused on reducing these gases, presenting the use of bioactive compounds (tannins) as an alternative in the diet. The aim of this research was to determine the effect of the addition of different levels of Acacia mearnsii on ruminal degradation, nutrient digestibility, and mitigation of greenhouse gas production. A completely randomized design with four treatments and six repetitions was used. The treatments were: T1, T2, T3, and T4 diets with, respectively, 0%, 20%, 40%, and 60% A. mearnsii. The rumen degradation kinetic and in vitro digestibility, and the production of gas, CH4, and CO2 were evaluated. In situ rumen degradation and in vitro digestibility of DM and OM showed differences between treatments, with T1 being higher (p < 0.05) in the degradation of the soluble fraction (A), potential degradation (A + B), and effective degradation for the different passage rates in percent hour (0.02, 0.05, and 0.08), compared to the other treatments. Rumen pH did not show differences (p > 0.05) between treatments. The lowest (p < 0.05) gas, CH4, and CO2 production was observed in treatments T1 and T2 with an approximate mean of 354.5 mL gas/0.500 g fermented DM, 36.5 mL CH4/0.500 g fermented DM, and 151.5 mL CO2/0.500 g fermented DM, respectively, compared to treatments T3 and T4. Under the conditions of this study, it was concluded that it is possible to replace traditional forages with up to 20% of A. mearnsii, without observing changes in the production of greenhouse gases with respect to the control treatment (0% of A. mearnsii); however, A. mearnsii is not usable because it significantly decreases rumen degradability of DM and OM, which would considerably affect the production in animals.

Characteristics of Medically Transported Critically Ill Children with Respiratory Failure in Latin America: Implications for Outcomes.

Several challenges exist for referral and transport of critically ill children in resource-limited regions such as Latin America; however, little is known about factors associated with clinical outcomes. Thus, we aimed to describe the characteristics of critically ill children in Latin America transferred to pediatric intensive care units for acute respiratory failure to identify risk factors for mortality. We analyzed data from 2,692 patients admitted to 28 centers in the Pediatric Collaborative Network of Latin America Acute Respiratory Failure Registry. Among patients referred from another facility (773, 28%), nonurban transports were independently associated with mortality (adjusted odds ratio = 9.4; 95% confidence interval: 2.4-36.3).

Beneficial Effect of Melatonin Alone or in Combination with Glatiramer Acetate and Interferon ß-1b on Experimental Autoimmune Encephalomyelitis.

Experimental autoimmune encephalomyelitis (EAE) is a relevant animal model of multiple sclerosis (MS). Oxidative stress and chronic inflammation play a major role in the pathogenesis of MS and EAE. Melatonin, a neurohormone, has potent anti-inflammatory properties. The aim of our study was to assess the therapeutic properties of melatonin alone or in combination with interferon ß-1b (IFNß-1b) or glatiramer acetate (GA) on EAE. EAE was induced in male Sprague-Dawley rats with an intraperitoneal injection of a homogenate of spinal cord and pig brain. At day 10 post immunization, rats were euthanized, and their brains were immediately excised and processed to measure oxidative stress markers and membrane fluidity. In addition, proinflammatory cytokines were quantified in plasma. Melatonin alone or in combination with GA and IFNß-1b inhibited the disease process of EAE and the synthesis of proinflammatory cytokines, caused a significant decrement in oxidative stress markers, and preserved the membrane fluidity in the motor cortex, midbrain, and spinal cord. The cumulative index score was significantly reduced in EAE rats treated with melatonin alone or in combination with GA and IFNß-1b. In conclusion, our findings provide preclinical evidence for the use of melatonin as an adjuvant therapeutic treatment for MS.

Radiology Education and Clinical Service during the COVID-19 Pandemic - the Puerto Rico Medical Center Experience.

Residency training programs have faced the dual challenge of providing continuous and effective clinical services and graduate medical education during the Coronavirus Disease 2019 (COVID-19) pandemic. This article outlines the changes incorporated by the University of Puerto Rico School of Medicine Diagnostic Radiology Program during the COVID-19 pandemic, including incorporating a virtual approach for read-out sessions, didactic conferences and additional learning experiences for the radiology residents. By means of collaboration and unity in the noble goal of public service, the faculty and residents of the Diagnostic Radiology Program at UPR-SOM have shown resilience throughout the many challenges faced during the current COVID-19 pandemic.

Lamotrigine Extraction and Quantification by UPLC-DAD in Plasma from Patients with Bipolar Disorder.

A sensitive and efficient analytical process for detecting lamotrigine in acidic solution based in ultra-high-performance liquid chromatography-diode array detector (UPLC-DAD) was developed; the stationary phase used was a C8, 150 × 4.6 mm, 2.6 µm. The mobile phase consisted of acetonitrile/acidified water (0.01% H3PO4 and 0.005% triethylamine, pH 2.4) (25 : 75 v/v). Limits of detection and quantification were 0.02 µg/mL and 0.05 µg/mL, respectively. The working interval for the evaluation of the method ranged from 0.05 to 12 µg/mL, and the linear fit of the experimental data has a value of r2≥0.98. Before quantifying lamotrigine in plasma of patients with bipolar disorder, lamotrigine was released from plasma proteins with a 0.2 M sodium hydroxide solution, and then proteins were removed by precipitation with acetonitrile. Afterward, the lamotrigine base was dissolved in ethyl acetate. This extract was reconstituted in potassium phosphate solution (pH 2.4) to obtain more than 98% of lamotrigine protonated in N2, which was detected and quantified as indicated above. The absolute percentage of lamotrigine recovery is ≥80% for all tested concentration levels. The accuracy and precision of the method have %CV values <4% for the lamotrigine levels of 3, 6, and 9 µg/mL. The correlation coefficient for the used concentration range is 0.99. The analytical method is precise and sensitive to measure lamotrigine levels expected in plasma of BD patients and these levels were in the therapeutic dose range.

Prevalence of Metabolic Syndrome Among Mexican Adults.

Background: Metabolic syndrome (MetS) has increased worldwide, and since 2012, prevalence of obesity, hypertension, diabetes, and dyslipidemia has increased in Mexico. Objective: To assess the prevalence of MetS, and its relationship with sociodemographic and lifestyle factors among Mexican adults. Methods: Analytical cross-sectional study nationally representative, carried out on Mexican adults (≥20-year-old adults of both sexes; n = 4595). Socioeconomic factors, geographic area, health care coverage and previous medical diagnoses of diabetes and hypertension, and smoking were assessed. Anthropometrics, and triglyceride, total cholesterol, high-density lipoprotein cholesterol (HDL-chol), creatinine, and glucose plasma levels were measured. The ATP III MetS definition was applied. Results: A MetS prevalence of 44.2% was observed, which was higher in males than females, and increased with age, lower school level, and overweight. Hyperglycemia, hypertriglyceridemia, low HDL-chol, abdominal obesity, and hypertension were higher in people with MetS, and were associated with obesity. Conclusions: The prevalence of MetS in the Mexican adult observed in the ENSADER 2007 was high, and mainly in men than women. Specific associations of MetS with age, scholar level, and body mass index have been found. Obesity and MetS were associated.

High prevalence of SARS-CoV-2 detection and prolonged viral shedding in stools: A systematic review and cohort study.

OBJECTIVES: To: 1. Describe the frequency of viral RNA detection in stools in a cohort of patients infected with SARS-CoV-2, and 2. Perform a systematic review to assess the clearance time in stools of SARS-CoV-2. METHODS: We conducted a prospective cohort study in two centers between March and May 2020. We included SARS-CoV-2 infected patients of any age and severity. We collected seriated nasopharyngeal swabs and stool samples to detect SARS-CoV-2. After, we performed a systematic review of the prevalence and clearance of SARS-CoV-2 in stools (PROSPERO-ID: CRD42020192490). We estimated prevalence using a random-effects model. We assessed clearance time by using Kaplan-Meier curves. RESULTS: We included 32 patients; mean age was 43.7±17.7 years, 43.8% were female, and 40.6% reported gastrointestinal symptoms. Twenty-five percent (8/32) of patients had detectable viral RNA in stools. The median clearance time in stools of the cohort was 11[10-15] days. Systematic review included 30 studies (1392 patients) with stool samples. Six studies were performed in children and 55% were male. The pooled prevalence of viral detection in stools was 34.6% (twenty-four studies, 1393 patients; 95%CI:25.4-45.1); heterogeneity was high (I2:91.2%, Q:208.6; p≤0.001). A meta-regression demonstrates an association between female-gender and lower presence in stools (p=0.004). The median clearance time in stools was 22 days (nineteen studies, 140 patients; 95%CI:19-25). After 34 days, 19.9% (95%CI:11.3-29.7) of patients have a persistent detection in stools. CONCLUSIONS: Detection of SARS-CoV-2 in stools is a frequent finding. The clearance of SARS-CoV-2 in stools is prolonged and it takes longer than nasopharyngeal secretions.

Mitigation of ruminal methane production with enhancing the fermentation by supplementation of different tropical forage legumes.

The aim of this research was to evaluate the influence of forage species adapted to the tropical region of Ecuador on gas production, enteric methane, digestion, and ruminal fermentation. The tree forage evaluated were C. arborea, E. fusca, B. forficata, E. poeppigiana, C. argentea, G. sepium, C. tora, and F. macrophylla. Ruminal fluid of four adult sheep fistulated with permanent cannulas in the rumen was used in the in vitro gas production technique. The in vitro gas production parameters were lower (P < 0.05) in the C. arborea (A = 41.68 mL gas/g DM, c = 0.044%/h and Lag = 1.654 h) and the average gas production rate for B. forficata was 1.017 mL/h (P < 0.05). C. arborea presented higher (P = 0.0001) effective degradation and real DM digestibility (40.461 g/kg and 82.51 mg/g, respectively). With respect to VFA, the highest (P < 0.05) proportion of acetic, propionic, and butyric was observed in C. arborea, G. sepium, and E. poeppigiana (72.52, 23.09, and 7.44 mol/100 mol, respectively) and the lowest (P = 0.0001) ratio: acetic/propionic was observed in G. sepium (2.92 mol/100 mol). The content of NH3-N (mg/L) showed no difference. The lowest (P = 0.0001) methane production was observed in C. arborea (1.23 mL CH4/g DM). The use of forage species of tropical climate rich in secondary metabolites in ruminant diets has the capacity to reduce the gas production and enteric methane; however, this is at the expense of the reduction of the fermentation of organic matter in the rumen.