Divergence in three newly identified Arthrospira species from Mexico.

Arthrospira (Spirulina) is a microalgae that has a unique set of biological characteristics which are very useful for a broad range of applications. Based on its worldwide requirements, this investigation was conducted to collect, isolate and identify the local Arthrospira strains in the central and western part of Mexico. We have successfully collected, isolated and identified (morphologically as well as molecularly) three Arthrospira strains from different regions in Mexico. Morphological studies were conducted by analyzing the size and shape of the helix, the spiral pattern, cell length and width with the help of light microscopy and for molecular analysis, the 16S rRNA and internally transcribed spacer (ITS, 16S-23 rRNA) gene partial sequence were used followed by phylogenetic analysis. The three species were completely different in their filament size and width whereas their ITS sequences were the same in size and more than 87 % similar in nucleotide sequence. The resulted morphological and phylogenetic analysis concluded that the three stains were identified as Arthrospira platensis. Inspite of their morphological variations and differences they were grouped genetically into one cluster along with the A. platensis of reported strains of Gene Bank database (NCBI). One of the isolated strains NPS-0, is probably the biggest Arthrospira strains ever reported and can be suitable for industrial scale biomass and protein production.

Comparative Studies for Cryopreservation of Agave Shoot Tips by Droplet-Vitrification.

The objective of this work was to assess the suitability of the Droplet-vitrification protocol previously developed with Agave peacockii shoot tips for the cryopreservation of six Agave species. Shoot tips were precultured for 1 day on a medium with 0.3 M sucrose in the dark, loaded in a solution with 1.6 M glycerol and 0.4 M sucrose for 20 min, and dehydrated by exposure to Plant Vitrification Solution 2 (PVS2) at 0 °C for 20 min. Complementary studies using histological analysis, Differential scanning calorimetry (DSC), and evaluation of morphological characteristics in cryo-derived plants were performed. Survival rates ranged from 84% to 100% and from 76% to 97% before and after cryopreservation regardless of the Agave species belonging to two taxonomic subgenera. Thermal analysis of shoot tips subjected to the successive steps of the Droplet-vitrification protocol identified ice crystal formation after loading treatment and glass transition after osmotic dehydration with PVS2. The average glass transition temperature (Tg) was -55.44 °C based on the results of four Agave species. The histological studies showed the anatomical differences that could be found in the meristematic structures depending on the loss of apical dominance. This is the most advanced research on cryopreservation of Agave shoot tips.

PGPB Consortium Formulation to Increase Fermentable Sugar in Agave tequilana Weber var. Blue: A Study in the Field.

Agave tequilana Weber var. Blue is used as the primary raw material in tequila production due to its fructans (inulin) content. This study evaluates the formulation of a plant-growth-promoting bacteria (PGPB) consortium (Pseudomonas sp. and Shimwellia sp.) to increase sugars in A. tequilana under field conditions. A total of three doses were tested: low (5 L ha-1), medium (10 L ha-1), and high (15 L ha-1), with a cellular density of 1 × 108 CFU mL-1 and one control treatment (without application). Total reducing sugars (TRS), inulin, sucrose, glucose, fructose, and plant growth were measured in agave plants aged 4-5 years at 0 (T0), 3 (T3), 6 (T6), and 12 (T12) months. Yield was recorded at T12. The TRS increased by 3%, and inulin by 5.3% in the high-dose treatment compared to the control at T12. Additionally, a low content of sucrose, glucose, and fructose (approximately 1%) was detected. At T12, the weight of agave heads increased by 31.2% in the medium dose and 22.3% in the high dose compared to the control. The high dose provided a higher inulin content. The A. tequilana plants were five years old and exhibited growth comparable to the standards for 6-7-year-old plants. This study demonstrates a sustainable strategy for tequila production, optimizing the use of natural resources and enhancing industry performance through increased sugar content and yield.

The Spanish Fabry women study: a retrospective observational study describing the phenotype of females with GLA variants.

BACKGROUND: Fabry disease (FD) is an X-linked condition caused by variants in the GLA gene. Since females have two X chromosomes, they were historically thought to be carriers. Although increased knowledge has shown that females often develop the disease, data from Spain and other countries reported that females were undertreated. The aim of this study was to provide a wider and more recent description of the disease characteristics and associated management of females with a GLA variant in a Spanish cohort. RESULTS: Ninety-seven females from 12 hospitals were included in this retrospective study. Mean age was 50.1 ± 17.2 years. Median follow-up time from GLA variant identification was 36.1 months, and most (70.1%) were identified through family screening. Variants associated with classic/non-classic phenotypes were similarly distributed (40.2%/53.6%). Missense variants were the most prevalent (n = 84, 86.6%). In the overall group, 70.4% had major organ involvement (i.e., cardiac, renal, cerebrovascular, peripheral nervous system or gastrointestinal), and 47.3% also had typical Fabry signs (angiokeratoma, cornea verticillata or increased plasma lyso-Gb3). Cardiac involvement was the most prevalent (49.5%) and the main reason for treatment initiation. A total of 33 (34%) patients received disease-specific therapy, 55% of whom were diagnosed by family screening. Females carrying variants associated with a classic phenotype had higher frequencies of clinical manifestations (92.3%) and were predominant in the treated subgroup (69.7%). Despite this, there were 34 untreated females (56.7% of total untreated), with both phenotypes represented, who had major organ involvement, with 27 of cardiac, renal or cerebrovascular nature. Age or comorbidities in this subgroup were comparable to the treated subgroup (P = 0.8 and P = 0.8, respectively). CONCLUSIONS: Efforts have been made in recent years to diagnose and treat timely Fabry females in Spain. A high percentage of females with pathogenic variants, regardless of their associated phenotype, will likely develop disease. A proportion of females with severe disease in this cohort received specific treatment. Still a significant number of females, even with same profile as the treated ones, who may be eligible for treatment according to European recommendations, remained untreated. Reasons for this merit further investigation.

An F-Actin Mega-Cable Is Associated With the Migration of the Sperm Nucleus During the Fertilization of the Polarity-Inverted Central Cell of Agave inaequidens.

Asparagaceae's large embryo sacs display a central cell nucleus polarized toward the chalaza, which means the sperm nucleus that fuses with it during double fertilization migrates an atypical long distance before karyogamy. Because of the size and inverted polarity of the central cell in Asparagaceae, we hypothesize that the second fertilization process is supported by an F-actin machinery different from the short-range F-actin structures observed in Arabidopsis and other plant models. Here, we analyzed the F-actin dynamics of Agave inaequidens, a classical Asparagaceae, before, during, and after the central cell fertilization. Several parallel F-actin cables, spanning from the central cell nucleus to the micropylar pole, and enclosing the vacuole, were observed. As fertilization progressed, a thick F-actin mega-cable traversing the vacuole appeared, connecting the central cell nucleus with the micropylar pole near the egg cell. This mega-cable wrapped the sperm nucleus in transit to fuse with the central cell nucleus. Once karyogamy finished, and the endosperm started to develop, the mega-cable disassembled, but new F-actin structures formed. These observations suggest that Asparagaceae, and probably other plant species with similar embryo sacs, evolved an F-actin machinery specifically adapted to support the migration of the fertilizing sperm nucleus within a large-sized and polarity-inverted central cell.

Predictive factors for cardiac conduction abnormalities with hydroxychloroquine-containing combinations for COVID-19.

This longitudinal, prospective cohort study aimed to assess risk of QTc interval prolongation and its predicting factors in subjects treated with combinations containing hydroxychloroquine (HCQ) for COVID-19. Moderate-to-severe QTc prolongation during therapy was defined as a QTc interval >470 ms in men or >480 ms in women. Patients were treated under strict cardiac supervision. A total of 105 adults were included [56% male; median (IQR) age 69 (57-79) years]. All patients received therapy with HCQ in combination with azithromycin (AZM), and 95 (90%) also with lopinavir/ritonavir (LPV/r). Concomitant medications classified as having risk of developing torsades de pointes (TdP) were simultaneously used in 81 patients (77%). Moderate-to-severe QTc prolongation was observed in 14 patients (13%), mostly at Days 3-5 from baseline, with 6 (6%) developing severe prolongation (>500 ms). There was no evidence of TdP arrhythmia or TdP-associated death. Adding LPV/r to HCQ+AZM did not significantly prolong the QTc interval. Multivariable Cox regression revealed that comedications with known risk of TdP (HR = 11.28, 95% CI 1.08-117.41), higher neutrophil-to-lymphocyte (NLR) ratio (HR = 1.10, 95% CI 1.03-1.18 per unit increase) and higher serum hs-cardiac troponin I (HR = 4.09, 95% CI 1.36-12.2 per unit increase) were major contributors to moderate-to-severe QTc prolongation. In this closely screened and monitored cohort, no complications derived from QTc prolongation were observed during pharmacological therapy containing HCQ for COVID-19. Evidence of myocardial injury with elevated troponin and strong inflammatory response, specifically higher NLR, are conditions requiring careful QTc interval monitoring.

Application of in Casa Pollination and Embryo Rescue Techniques for Breeding of Agave Species.

Species of the genus Agave are distributed originally in the tropical and subtropical areas of the American continent with about 200 taxa and 136 species, and its center of origin is probably limited to México. These kind of plants usually grow and live in extreme environmental conditions such as heat and drought where their CAM pathway for fixing CO2 allow them to survive in conditions where other plants cannot survive. Although this kind of plants resist harsh environmental conditions, climate change is imposing stronger kinds of stress that diminish their productive potential and in some cases are cause of death. Because of this, genetic improvement becomes a need of fundamental importance in this kind of species. Despite their economic importance, Agave species have received scarce attention with regard to its genetic improvement, probably due to their unique botanical features such as plant architecture, spines, long life span, and monocarpy, among others, which make hybridization a difficult task for the intra- and interspecific gene transfer and creation of genetic variability among many other breeding techniques.The protocol here presented is a combination of a novel hybridization technique and biotechnological tools, and allows the use of several procedures for the genetic improvement of agaves such as pollen selection, clonal selection, and somatic cell selection, among others, since the rescued embryos can be used for micropropagation, for phenotype/genotype selection or the production of cell lineages for diverse genetic improvement purposes.

Micropropagation of Agave salmiana: Means to Production of Antioxidant and Bioactive Principles.

Maguey, Agave salmiana, is an important plant for the "pulque" beverage and functional food industries; however, it has several constraints for elite and homogeneous plant production. In this study, a micropropagation process was established to generate in vitro plants. The effect of the method on metabolite content and antioxidant (AOX) activity in regenerated plants was evaluated. Young germinated plantlets were micropropagated from axillary shoots using Murashige and Skoog medium supplemented with L2 vitamins, 0.04 mg/L 2,4-dichlorophenoxyacetic acid and 10 mg/L 6-benzylaminopurine. Total soluble sugars from the aqueous fraction and total phenolic acids, total saponins, and AOX activity of the methanol fraction were determined in wild-type (WT) plants, in in vitro (IN) plants, and ex vitro acclimated plants (EN). The results showed that IN plants have a 50% lower soluble sugar content compared to WT, and EN. The total phenolic acids content was at least 30% higher in micropropagated (IN) and regenerated (EN) plants compared to WT. The total saponin content in IN, and EN plants was 36 and 25 times higher compared to WT. The AOX capacity of IN plants was on average three times higher compared to other treatments. However, no correlation was found between the AOX activity and total phenolic acids or total saponins. A negative and significant correlation (r = -0.927; p = 0.003) was found between the AOX activity and the total soluble sugars content. Micropropagated plants of A. salmiana have a different phytochemical content and bioactivity after the in vitro process compared to WT plants. The micropropagation process could be used as a platform for phytochemical enhancement of Agave plants.

[Factors associated with resistance to human immunodeficiency virus protease inhibitors]. / Factores asociados a la resistencia a los inhibidores de la proteasa del virus de la inmunodeficiencia humana.

BACKGROUND: To assess the risk factors associated with genotypic resistance to protease inhibitors (PI) in HIV-infected subjects with virologic failure despite highly active antiretroviral treatment (HAART). PATIENTS AND METHOD: Retrospective chart review including 47 consecutive patients with virologic failure despite PI-based HAART who had undergone a genotypic HIV-1 testing. The prevalence of genotypic resistance to PI was determined and several demographic, clinical and laboratory variables were compared between patients with and without genotypic resistance to those drugs. RESULTS: The entire nucleotide sequence of the protease gene was obtained in 43 of the 47 patients; 18 of them had genotypic resistance to PI. Genotypic resistance to PI was associated with a previous therapy with suboptimal antiretroviral regimens (OR = 10.2; 95% CI, 1.05-245.1; P = 0.02), duration of antiretroviral therapy longer than 18 months (OR = 13.3; 95% CI, 1.23-340.85; P = 0.01), greater number of antiretroviral regimens and drugs before the virologic failure (p < 0.01) and presence of the 184V mutation in the reverse transcriptase gene (OR = 5.6; 95% CI, 1.2-29.2; P = 0.02). There was no relationship between PI resistance and the risk group, viral load or CD4 cell count. In the multivariate analysis, previous therapy with suboptimal antiretroviral regimens was the better predictor of PI resistance (OR = 11.1; 95% CI, 1.04-117.47; P = 0.046). CONCLUSIONS: Patients treated with suboptimal antiretroviral activity regimens before starting HAART can be at greater risk of developing genotypic resistance to protease inhibitors.

Embryo sac formation and early embryo development in Agave tequilana (Asparagaceae).

Agave tequilana is an angiosperm species that belongs to the family Asparagaceae (formerly Agavaceae). Even though there is information regarding to some aspects related to the megagametogenesis of A. tequilana, this is the first report describing the complete process of megasporogenesis, megagametogenesis, the early embryo and endosperm development process in detail. The objective of this work was to study and characterize all the above processes and the distinctive morphological changes of the micropylar and chalazal extremes after fertilization in this species. The agave plant material for the present study was collected from commercial plantations in the state of Jalisco, Mexico. Ovules and immature seeds, previously fixed in FAA and kept in ethanol 70%, were stained based on a tissue clarification technique by using a Mayer's-Hematoxylin solution. The tissue clarification technique was successfully used for the characterization of the megasporogenesis, megagametogenesis, mature embryo sac formation, the early embryo and endosperm development processes by studying intact cells. The embryo sac of A. tequilana was confirmed to be of the monosporic Polygonum-type and an helobial endosperm formation. Also, the time-lapse of the developmental processes studied was recorded.

Diagnostic accuracy of clinical criteria for identifying systolic and diastolic heart failure: cross-sectional study.

OBJECTIVE: To determine the validity and clinical usefulness of clinical criteria in the diagnosis of systolic and diastolic heart failure. DESIGN: Cross-sectional diagnostic study. METHODS: 216 patients admitted consecutively to the cardiology section of an academic hospital with a suspected diagnosis of heart failure in a period of 12 months. A definite diagnosis of heart failure (echocardiographic diagnostic criteria of left ventricular dysfunction) was cross-matched with the results obtained using the test under investigation (Framingham clinical diagnostic criteria for heart failure). Sensitivity, specificity, positive predictive value, negative predictive value, likelihood ratio for positive test result (LR+) and likelihood ratio for negative test result (LR-) were calculated and used to construct clinical decision-making diagrams. RESULTS: The Framingham clinical criteria are very sensitive (92%) and moderately specific (79%). The diagnosis of heart failure was ruled out with a good LR- (0.1) but the diagnosis was confirmed with only a low level of evidence as the LR+ was 4.3. The main difference found between systolic and diastolic heart failure is that in the case of systolic failure the disease is ruled out conclusively (0.04), whereas in the case of diastolic failure the change in probability generated is at the borderline between conclusive and moderate (0.1). CONCLUSION: The absence of the Framingham clinical criteria rules out the diagnosis of heart failure, particularly in the case of systolic heart failure. However, the presence of these criteria do not necessarily confirm the diagnosis, which may be based in echocardiography.

Analysis of laser-induced fluorescence spectra of in vitro plant tissue cultures.

We demonstrate the effectiveness of laser-induced fluorescence (LIF) for monitoring the development and stress detection of in vitro tissue cultures in a nondestructive and noninvasive way. The changes in LIF spectra caused by the induction of organogenesis, the increase of the F690/F740 ratio as a result of the stress originated in the organogenic explants due to shoot emergence, and the relationship between fluorescence spectra and shoot development were detected by LIF through closed containers of Saintpaulia ionantha.

Factores asociados a la resistencia a los inhibidores de la proteasa del virus de la inmunodeficiencia humana / Factors associated with resistance to human immunodeficiency virus protease inhibitors

FUNDAMENTO: Evaluar los factores asociados con la presencia de resistencia genotípica frente a los inhibidores de la proteasa (IP) en sujetos infectados por el virus de la inmunodeficiencia humana (VIH) en situación de fracaso virológico a pesar del tratamiento antirretroviral de gran actividad (TARGA). PACIENTES Y MÉTODO: Estudio retrospectivo en 47 pacientes consecutivos con fracaso virológico con TARGA con IP a quienes se realizó un análisis genotípico del VIH. Se determinó la prevalencia de resistencia genotípica a los IP y se comparó la frecuencia de diversas variables demográficas, clínicas y analíticas en los pacientes con y sin resistencia frente a estos fármacos. RESULTADOS: Se obtuvo la secuencia nucleotídica completa del gen de la proteasa en 43 de los 47 pacientes; 18 de ellos presentaban resistencia genotípica a los IP. La presencia de resistencia se asoció con haber recibido tratamiento previo con pautas de actividad antirretroviral subóptima (odds ratio [OR] = 10,2; intervalo de confianza [IC] del 95 por ciento, 1,05-245,1; p = 0,02), con una duración del tratamiento superior a 18 meses (OR = 13,3; IC del 95 por ciento, 1,23-340,85; p = 0,01), con un mayor número de pautas y agentes antirretrovirales recibidos antes del fracaso terapéutico (p < 0,01) y con la presencia de la mutación 184V en el gen de la transcriptasa inversa (OR = 5,6; IC del 95 por ciento, 1,2-29,2; p = 0,02). No se encontró relación entre la resistencia a los IP y el grupo de riesgo, la carga viral o el recuento de linfocitos CD4. En el análisis multivariado el tratamiento previo con pautas de actividad antirretroviral subóptima fue el mejor predictor de resistencia a los IP (OR = 11,1; IC del 95 por ciento, 1,04-117,47; p = 0,046). CONCLUSIONES: Los pacientes tratados con pautas antirretrovirales de actividad subóptima antes del inicio del TARGA pueden tener un mayor riesgo de desarrollar resistencia genotípica a los IP. (AU)