Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 41
Filtrar
Más filtros

Bases de datos
Tipo del documento
Intervalo de año de publicación
1.
Langmuir ; 39(46): 16637-16647, 2023 Nov 21.
Artículo en Inglés | MEDLINE | ID: mdl-37934700

RESUMEN

Studying the interplay between the electrochemical performance and the electrolyte conditioning process is crucial for building an efficient magnesium battery. In this work, we use halogen-free electrolyte (HFE) based on Mg(NO3)2 in acetonitrile (ACN) and tetraethylene glycol dimethyl ether (G4) to study the effect of the aging time calendar on its electrochemical properties. The characterization techniques confirm apparent changes occurring in the bulk speciation and the Mg2+ solvation barrier of the aging HFE relative to the as-prepared fresh HFE. The overpotential of Mg plating/stripping and bulk resistance of the aging HFE is reduced relative to the as-prepared fresh HFE. Mg-S cells using aged HFE deliver high specific capacities (586 mA h/g), higher Coulombic efficiencies, and higher cycle life (up to 30 cycles at 25 °C) relative to Mg-S cells with fresh HFE that deliver a specific capacity of ∼535 mA h g-1, low Coulombic efficiency, and short cycle life at a current density of 0.02 mA cm-2. The present findings provide a new concept describing how the aging process regulates the electrochemical performance of the HFE and enhances the cycle life of Mg-S batteries.

2.
Langmuir ; 39(37): 13038-13049, 2023 Sep 19.
Artículo en Inglés | MEDLINE | ID: mdl-37661715

RESUMEN

Copper selenide (Cu-Se) and copper sulfide (Cu-S) are promising cathodes for magnesium-ion batteries. However, the low electronic conductivity of Cu-Se system results in a poor rate capability and unsatisfactory cycling performance. Mg-ion batteries based on the Cu-S cathode exhibited large kinetic barriers during the recharging process owing to the presence of polysulfide species. This work attempts to circumvent this dilemma by doping Cu1.8Se by sulfur, which replaces the selenium in the CuSe lattice to form Cu1.8Se0.6S0.4 nanocrystalline powder. The presence of sulfur will increase the electronic conductivity, and the presence of selenium will mitigate the effect of polysulfide species that hinder the kinetics of Mg2+. Herein, a Cu1.8Se0.6S0.4 nanocrystalline powder was synthesized by the solid-state reaction, yielding a highly pure and stoichiometric powder. The crystallographic structure of the nanopowder and the conversion-type storage mechanism have been attested via ex situ X-ray diffraction and energy-dispersive X-ray analysis. The nanocrystalline feature of Cu1.8Se0.6S0.4 was demonstrated by high-resolution transmission electron microscopy. An apparent surface morphology change during the charging/discharging process has been visualized by a field emission scanning electron microscope. Diffuse reflectance spectroscopy has discussed the variation of the band gap during charging and discharging. The full Mg/Cu1.8Se0.6S0.4 cells presented an initial discharge capacity of 387.99 mAh g-1 at a current density of 0.02 mA cm-2; moreover, they show moderate diffusion kinetics with DMg2+ ≈ 10-15 cm-2 s-1.

3.
Virol J ; 19(1): 185, 2022 11 12.
Artículo en Inglés | MEDLINE | ID: mdl-36371185

RESUMEN

BACKGROUND: Equine influenza is an important cause of respiratory disease in equids. The causative virus; EIV, is highly variable and can evolve by accumulation of mutations, particularly in the haemagglutinin (HA) gene. Currently, H3N8 is the sole subtype circulating worldwide with Florida clade 1 (FC1) is most prevalent in the Americas and FC2 in Asia and Europe. In Egypt, EIV was detected in two occasions: subtype H7N7 in 1989 and subtype H3N8 (FC1) in 2008. No data is available on the circulation pattern of EIV during the last decade despite frequent observation of suspected cases. METHODS: Twenty-two nasal swabs were collected from vaccinated and non-vaccinated horses showing respiratory signs suggestive of EIV infection in 2017-18. Three additional swabs were retrieved during a national race event in January 2018 from Arabian mares with high fever, gait stiffness and dry cough. Samples were screened by RT-qPCR and HA1 domain of the hemagglutinin gene was amplified and sequenced for sequence and phylogenetic analysis. RESULTS: RT-qPCR screening revealed that only the 3 samples from the race were positive with cycle thresholds ranging from 16 to 21 indicating high viral load. Isolation attempts in hen's eggs were unsuccessful. Sequence analysis of the HA1 domain gene has revealed two identical nucleotide sequences, while the third contained 3 synonymous mutations. Phylogenetic analysis clustered study sequences with recent FC2 sequences from Europe. Amino acid alignments revealed 14 and 13 amino acid differences in the study sequences compared to A/equine/Egypt/6066NANRU-VSVRI/08 (H3N8) and A/equine/Kentucky/1997 (H3N8), respectively, available as EIV vaccines in Egypt. Nine amino acids were different from A/equine/Richmond/1/2007 (H3N8), the recommended FC2 vaccine strain by the world organization of animal health expert surveillance panel (OIE-ESP), two of which were unique to the Egyptian sequences while the remaining 7 changes were shared with the FC2-144V subgroup detected in the United Kingdom from late 2015 to 2016. CONCLUSIONS: The study represents the first reported detection of FC2-144V related EIV from Arabian mares in Egypt, and probably from the entire middle east region. The presented information about EIV epidemiology and spread may require reconsideration of the vaccine strains used in the national vaccination programs.


Asunto(s)
Enfermedades de los Caballos , Subtipo H3N8 del Virus de la Influenza A , Subtipo H7N7 del Virus de la Influenza A , Infecciones por Orthomyxoviridae , Caballos , Animales , Femenino , Subtipo H3N8 del Virus de la Influenza A/genética , Egipto/epidemiología , Filogenia , Pollos , Infecciones por Orthomyxoviridae/epidemiología , Infecciones por Orthomyxoviridae/veterinaria , Infecciones por Orthomyxoviridae/prevención & control , Hemaglutininas , Aminoácidos/genética
4.
Virol J ; 18(1): 90, 2021 04 30.
Artículo en Inglés | MEDLINE | ID: mdl-33931099

RESUMEN

BACKGROUND: The Middle East Respiratory Syndrome-related Coronavirus (MERS-CoV) continues to exist in the Middle East sporadically. Thorough investigations of the evolution of human coronaviruses (HCoVs) are urgently required. In the current study, we studied amplified fragments of ORF1a/b, Spike (S) gene, ORF3/4a, and ORF4b of four human MERS-CoV strains for tracking the evolution of MERS-CoV over time. METHODS: RNA isolated from nasopharyngeal aspirate, sputum, and tracheal swabs/aspirates from hospitalized patients with suspected MERS-CoV infection were analyzed for amplification of nine variable genomic fragments. Sequence comparisons were done using different bioinformatics tools available. RESULTS: Several mutations were identified in ORF1a/b, ORF3/4a and ORF4b, with the highest mutation rates in the S gene. Five codons; 4 in ORF1a and 1 in the S gene, were found to be under selective pressure. Characteristic amino acid changes, potentially hosted and year specific were defined across the S protein and in the receptor-binding domain Phylogenetic analysis using S gene sequence revealed clustering of MERS-CoV strains into three main clades, A, B and C with subdivision of with clade B into B1 to B4. CONCLUSIONS: In conclusion, MERS-CoV appears to continuously evolve. It is recommended that the molecular and pathobiological characteristics of future MERS-CoV strains should be analyzed on regular basis to prevent potential future outbreaks at early phases.


Asunto(s)
Infecciones por Coronavirus/virología , Coronavirus del Síndrome Respiratorio de Oriente Medio/genética , Glicoproteína de la Espiga del Coronavirus/genética , Secuencia de Aminoácidos , Codón/genética , Biología Computacional , Infecciones por Coronavirus/fisiopatología , Infecciones por Coronavirus/prevención & control , Evolución Molecular , Genómica , Humanos , Coronavirus del Síndrome Respiratorio de Oriente Medio/aislamiento & purificación , Mutación , Sistemas de Lectura Abierta/genética , Filogenia , Reacción en Cadena en Tiempo Real de la Polimerasa , Arabia Saudita , Esputo/virología
5.
J Med Virol ; 92(8): 1133-1140, 2020 08.
Artículo en Inglés | MEDLINE | ID: mdl-31777964

RESUMEN

Lower respiratory tract infections caused by Human orthopneumovirus are still a threat to the pediatric population worldwide. To date, the molecular epidemiology of the virus in Saudi Arabia has not been adequately charted. In this study, a total of 205 nasopharyngeal aspirate samples were collected from hospitalized children with lower respiratory tract symptoms during the winter seasons of 2014/15 and 2015/16. Human orthopneumovirus was detected in 89 (43.4%) samples, of which 56 (27.3%) were positive for type A and 33 (16.1%) were positive for type B viruses. The fragment that spans the two hypervariable regions (HVR1 and HVR2) of the G gene of Human orthopneumovirus A was amplified and sequenced. Sequence and phylogenetic analyses have revealed a genotype shift from NA1 to ON-1, which was prevalent during the winter seasons of 2007/08 and 2008/09. Based on the intergenotypic p-distance values, ON-1 was reclassified as a subgenotype of the most predominant genotype GA2. Three conserved N-glycosylation sites were observed in the HVR2 of Saudi ON-1 strains. The presence of a 23 amino acid duplicated region in ON-1 strains resulted in a higher number of O-glycosylation sites as compared to other genotypes. The data presented in this report outlined the replacement of NA1 and NA2 subgenotypes in Saudi Arabia with ON-1 within 7 to 8 years. The continuous evolution of Human orthopneumovirus through point mutations and nucleotide duplication may explain its ability to cause recurrent infections.


Asunto(s)
Filogenia , Infecciones por Virus Sincitial Respiratorio/epidemiología , Virus Sincitial Respiratorio Humano/clasificación , Virus Sincitial Respiratorio Humano/genética , Preescolar , Femenino , Genotipo , Humanos , Lactante , Masculino , Mutación , Nasofaringe/virología , Prevalencia , ARN Viral/genética , Infecciones por Virus Sincitial Respiratorio/virología , Arabia Saudita/epidemiología , Estaciones del Año , Análisis de Secuencia de ADN , Factores Sexuales
6.
Arch Virol ; 164(8): 1981-1996, 2019 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-31139937

RESUMEN

Acute lower respiratory tract infection is a major health problem that affects more than 15% of the total population of Saudi Arabia each year. Epidemiological studies conducted over the last three decades have indicated that viruses are responsible for the majority of these infections. The epidemiology of respiratory viruses in Saudi Arabia is proposed to be affected mainly by the presence and mobility of large numbers of foreign workers and the gathering of millions of Muslims in Mecca during the Hajj and Umrah seasons. Knowledge concerning the epidemiology, circulation pattern, and evolutionary kinetics of respiratory viruses in Saudi Arabia are scant, with the available literature being inconsistent. This review summarizes the available data on the epidemiology and evolution of respiratory viruses. The demographic features associated with Middle East respiratory syndrome-related coronavirus infections are specifically analyzed for a better understanding of the epidemiology of this virus. The data support the view that continuous entry and exit of pilgrims and foreign workers with different ethnicities and socioeconomic backgrounds in Saudi Arabia is the most likely vehicle for global dissemination of respiratory viruses and for the emergence of new viruses (or virus variants) capable of greater dissemination.


Asunto(s)
Infecciones por Coronavirus/epidemiología , Infecciones del Sistema Respiratorio/epidemiología , Animales , Infecciones por Coronavirus/virología , Humanos , Islamismo , Coronavirus del Síndrome Respiratorio de Oriente Medio/aislamiento & purificación , Infecciones del Sistema Respiratorio/virología , Arabia Saudita/epidemiología , Viaje
7.
J Physiol ; 595(23): 7167-7183, 2017 12 01.
Artículo en Inglés | MEDLINE | ID: mdl-29044528

RESUMEN

KEY POINTS: Chronic limb ischaemia, characterized by inflammatory mediator release and a low extracellular pH, leads to acid-sensing ion channel (ASIC) activation and reflexively increases mean arterial pressure; endomorphin release is also increased under inflammatory conditions. We examined the modulation of ASIC currents by endomorphins in sensory neurons from rats with freely perfused and ligated femoral arteries: peripheral artery disease (PAD) model. Endomorphins potentiated sustained ASIC currents in both groups of dorsal root ganglion neurons, independent of mu opioid receptor stimulation or G protein activation. Intra-arterial administration of lactic acid (to simulate exercising muscle and evoke a pressor reflex), endomorphin-2 and naloxone resulted in a significantly greater pressor response than lactic acid alone, while administration of APETx2 inhibited endomorphin's enhancing effect in both groups. These results suggest a novel role for endomorphins in modulating ASIC function to effect lactic acid-mediated reflex increase in arterial pressure in patients with PAD. ABSTRACT: Chronic muscle ischaemia leads to accumulation of lactic acid and other inflammatory mediators with a subsequent drop in interstitial pH. Acid-sensing ion channels (ASICs), expressed in thin muscle afferents, sense the decrease in pH and evoke a pressor reflex known to increase mean arterial pressure. The naturally occurring endomorphins are also released by primary afferents under ischaemic conditions. We examined whether high affinity mu opioid receptor (MOR) agonists, endomorphin-1 (E-1) and -2 (E-2), modulate ASIC currents and the lactic acid-mediated pressor reflex. In rat dorsal root ganglion (DRG) neurons, exposure to E-2 in acidic solutions significantly potentiated ASIC currents when compared to acidic solutions alone. The potentiation was significantly greater in DRG neurons isolated from rats whose femoral arteries were ligated for 72 h. Sustained ASIC current potentiation was also observed in neurons pretreated with pertussis toxin, an uncoupler of G proteins and MOR. The endomorphin-mediated potentiation was a result of a leftward shift of the activation curve to higher pH values and a slight shift of the inactivation curve to lower pH values. Intra-arterial co-administration of lactic acid and E-2 led to a significantly greater pressor reflex than lactic acid alone in the presence of naloxone. Finally, E-2 effects were inhibited by pretreatment with the ASIC3 blocker APETx2 and enhanced by pretreatment with the ASIC1a blocker psalmotoxin-1. These findings have uncovered a novel role of endomorphins by which the opioids can enhance the lactic acid-mediated reflex increase in arterial pressure that is MOR stimulation-independent and APETx2-sensitive.


Asunto(s)
Canales Iónicos Sensibles al Ácido/metabolismo , Analgésicos Opioides/farmacología , Presión Sanguínea , Ácido Láctico/farmacología , Oligopéptidos/farmacología , Enfermedad Arterial Periférica/metabolismo , Bloqueadores del Canal Iónico Sensible al Ácido/farmacología , Potenciales de Acción , Analgésicos Opioides/administración & dosificación , Animales , Línea Celular , Células Cultivadas , Sinergismo Farmacológico , Ganglios Espinales/efectos de los fármacos , Ganglios Espinales/metabolismo , Miembro Posterior/irrigación sanguínea , Isquemia/metabolismo , Isquemia/fisiopatología , Ácido Láctico/administración & dosificación , Masculino , Ratones , Naloxona/administración & dosificación , Naloxona/farmacología , Oligopéptidos/administración & dosificación , Enfermedad Arterial Periférica/fisiopatología , Ratas , Ratas Sprague-Dawley , Reflejo , Células Receptoras Sensoriales/efectos de los fármacos , Células Receptoras Sensoriales/metabolismo
8.
J Neurophysiol ; 115(3): 1577-86, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-26843606

RESUMEN

The mechanisms by which G proteins modulate voltage-gated Ca(2+)channel currents (CaV), particularly CaV2.2 and CaV2.3, are voltage dependent (VD) or voltage independent (VI). VD pathways are typically mediated by Gαi/oand GαSsubfamilies. On the other hand, VI inhibition modulation is coupled to the Gαqsubfamily and signaling pathways downstream of phospholipase C stimulation. In most studies, this latter pathway has been shown to be linked to Gαqand/or Gα11protein subunits. However, there are no studies that have examined whether natively expressed Gα14subunits (Gαqsubfamily member) couple G protein-coupled receptors (GPCR) with CaV2.2 channels. We report that Gα14subunits functionally couple the substance P (SP)/neurokinin-1 (NK-1) receptor pathway to CaV2.2 channels in acutely dissociated rat celiac-superior mesenteric ganglion (CSMG) neurons. Exposure of CSMG neurons to SP blocked the CaV2.2 currents in a predominantly VD manner that was pertussis toxin and cholera toxin resistant, as well as Gαq/11independent. However, silencing Gα14subunits significantly attenuated the SP-mediated Ca(2+)current block. In another set of experiments, exposure of CSMG neurons to SP led to the inhibition of KCNQ K(+)M-currents. The SP-mediated M-current block was significantly reduced in neurons transfected with Gα14small-interference RNA. Finally, overexpression of the GTP-bound Gαq/11binding protein RGS2 did not alter the block of M-currents by SP but significantly abolished the oxotremorine methiodide-mediated M-current inhibition. Taken together, these results provide evidence of a new Gα14-coupled signaling pathway that modulates CaV2.2 and M-currents via SP-stimulated NK-1 receptors in CSMG neurons.


Asunto(s)
Canales de Calcio Tipo R/metabolismo , Subunidades alfa de la Proteína de Unión al GTP/metabolismo , Ganglios Simpáticos/metabolismo , Canales de Potasio KCNQ/metabolismo , Neuronas/metabolismo , Receptores de Neuroquinina-1/metabolismo , Potenciales de Acción , Animales , Células Cultivadas , Ganglios Simpáticos/citología , Masculino , Neuronas/fisiología , Proteínas RGS/metabolismo , Ratas , Ratas Sprague-Dawley , Sistemas de Mensajero Secundario
9.
J Med Virol ; 88(6): 1086-91, 2016 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-26595650

RESUMEN

Respiratory tract infections are a principal cause of illness and mortality in children worldwide and mostly caused by viruses. In this study, the epidemiology of 11 respiratory RNA viruses was investigated in a cohort of hospitalized children at a tertiary referral center in Riyadh from February 2008 to March 2009 using conventional and real-time monoplex RT-PCR assays. Among 174 nasopharyngeal aspirates, respiratory syncytial virus (RSV) was detected in 39 samples (22.41%), influenza A virus in 34 (19.54%), metapneumovirus (MPV) in 19 (10.92%), coronaviruses in 14 (8.05%), and parainfluenza viruses (PIVs) in 11 (6.32%). RSV, PIVs and coronaviruses were most prevalent in infants less than 6 months old, whereas MPV and influenza A virus were more prominent in children aged 7-24 and 25-60 months, respectively. The majority of the viruses were identified during winter with two peaks observed in March 2008 and January 2009. The presented data warrants further investigation to understand the epidemiology of respiratory viruses in Saudi Arabia on spatial and temporal basis.


Asunto(s)
Niño Hospitalizado , Infecciones por Virus ARN/epidemiología , Infecciones por Virus ARN/virología , Infecciones del Sistema Respiratorio/epidemiología , Infecciones del Sistema Respiratorio/virología , Preescolar , Coronavirus/genética , Coronavirus/aislamiento & purificación , Estudios Transversales , Femenino , Humanos , Lactante , Recién Nacido , Virus de la Influenza A/genética , Virus de la Influenza A/aislamiento & purificación , Masculino , Metapneumovirus/genética , Metapneumovirus/aislamiento & purificación , Nasofaringe/virología , Virus de la Parainfluenza 1 Humana/genética , Virus de la Parainfluenza 1 Humana/aislamiento & purificación , Virus Sincitial Respiratorio Humano/genética , Arabia Saudita/epidemiología , Estaciones del Año
10.
J Neurophysiol ; 112(12): 3104-15, 2014 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-25231620

RESUMEN

The exercise pressor reflex, a crucial component of the cardiovascular response under physiological and pathophysiological states, is activated via metabolic and mechanical mediators that originate from contracting muscles and stimulate group III and IV afferents. We reported previously that stimulation of mu opioid receptors (MOR), expressed in both afferents, led to a significant attenuation of the reflex in rats whose femoral arteries had been occluded for 72 h. The present study examined the effect of arterial occlusion on the signaling components involved in the opioid-mediated modulation of Ca(2+) channels in rat dorsal root ganglion neurons innervating the triceps surae muscles. We focused on neurons that were transfected with cDNA coding for enhanced green fluorescent protein whose expression is driven by the voltage-gated Na(+) channel 1.8 (Na(V)1.8) promoter region, a channel expressed primarily in nociceptive neurons. With the use of a small interference RNA approach, our results show that the pertussis toxin-sensitive Gα(i3) subunit couples MOR with Ca(2+) channels. We observed a significant leftward shift of the MOR agonist [D-Ala2-N-Me-Phe4-Glycol5]-enkephalin concentration-response relationship in neurons isolated from rats with occluded arteries compared with those that were perfused freely. Femoral occlusion did not affect Ca(2+) channel density or the fraction of the main Ca(2+) channel subtype. Furthermore, Western blotting analysis indicated that the leftward shift did not result from either increased Gα(i3) or MOR expression. Finally, all neurons from both groups exhibited an inward current following exposure of the transient potential receptor vanilloid 1 (TRPV1) agonist, 8-methyl-N-vanillyl-6-nonenamide. These findings suggest that sensory neurons mediating the exercise pressor reflex express Na(V)1.8 and TRPV1 channels, and femoral occlusion alters the MOR pharmacological profile.


Asunto(s)
Canales de Calcio/metabolismo , Señalización del Calcio , Receptores Opioides mu/metabolismo , Células Receptoras Sensoriales/metabolismo , Animales , Arteria Femoral/lesiones , Subunidades alfa de la Proteína de Unión al GTP/metabolismo , Ganglios Espinales/citología , Ganglios Espinales/metabolismo , Proteínas Fluorescentes Verdes/análisis , Masculino , Músculo Esquelético/inervación , ARN Mensajero/metabolismo , Ratas , Ratas Sprague-Dawley
11.
Arch Virol ; 159(1): 73-81, 2014 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-23884633

RESUMEN

Human respiratory syncytial virus (HRSV) is a frequent cause of hospitalization and mortality in children worldwide. The molecular epidemiology and circulation pattern of HRSV in Saudi Arabia is mostly uncharted. In the current study, the genetic variability and phylogenetic relationships of HRSV type A strains circulating in Riyadh Province were explored. Nasopharyngeal aspirates were collected from hospitalized children with acute respiratory symptoms during the winter-spring seasons of 2007/08 and 2008/09. Among 175 samples analyzed, 39 (22.3 %) were positive for HRSV by one-step RT-PCR (59 % type A and 41 % type B). Propagation of positive samples in HEp-2 cells permitted the recovery of the first Saudi HRSV isolates. Genetic variability among Saudi HRSV-A strains was evaluated by sequence analysis of the complete attachment (G) protein gene. The nucleotide sequence was compared to representatives of the previously identified HRSV-A genotypes. Sequence and phylogenetic analysis showed that the strains examined in this study were very closely related at both the nucleotide and amino acid level, and all of them are clustered in the GA2 genotype (and mostly belonged to the NA-1 subtype). A total of 23 mutation sites, 14 of which resulted in an amino acid change, were recorded only in Saudi strains. This is the first report on genetic diversity of HRSV-A strains in Saudi Arabia. Further analysis of strains on a geographical and temporal basis is needed to fully understand HRSV-A circulation patterns in Saudi Arabia.


Asunto(s)
Variación Genética , Infecciones por Virus Sincitial Respiratorio/virología , Virus Sincitial Respiratorio Humano/aislamiento & purificación , Proteínas del Envoltorio Viral/genética , Secuencia de Aminoácidos , Preescolar , Femenino , Humanos , Lactante , Masculino , Datos de Secuencia Molecular , Mutación , Filogenia , Infecciones por Virus Sincitial Respiratorio/epidemiología , Virus Sincitial Respiratorio Humano/clasificación , Virus Sincitial Respiratorio Humano/genética , Arabia Saudita/epidemiología , Estaciones del Año , Alineación de Secuencia
12.
Virus Genes ; 48(2): 252-9, 2014 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-24370974

RESUMEN

The genetic variability and circulation pattern of human respiratory syncytial virus group B (HRSV-B) strains, identified in Riyadh during the winters of 2008 and 2009, were evaluated by partial sequencing of the attachment (G) protein gene. The second hypervariable region (HVR-2) of G gene was amplified by RT-PCR, sequenced and compared to representatives of different HRSV-B genotypes. Sequence and phylogenetic analysis revealed that all Saudi strains belonged to the genotype BA, which is characterized by 60-nucleotide duplication at HVR-2. Only strains of 2008 were clustered with subgroup BA-IV, while those isolated at 2009 were clustered among the most recent subgroups (particularly BA-X and CB-B). Amino acid sequence analysis demonstrated 18 amino acid substitutions in Saudi HRSV-B strains; among which five are specific for individual strains. Furthermore, two potential N-glycosylation sites at residues 230 and 296 were identified for all Saudi strains, and an additional site at amino acid 273 was found only in Riyadh 28/2008 strain. O-glycosylation was predicted in 42-43 sites, where the majority (no = 38) are highly conserved among Saudi strains. The average ratio between non-synonymous and synonymous mutations (ω) implied stabilizing selection pressure on G protein, with evidences of positive selection on certain Saudi strains. This report provides preliminary data on the circulation pattern and molecular characteristics of HRSV-B strains circulating in Saudi Arabia.


Asunto(s)
Filogenia , Virus Sincitiales Respiratorios/aislamiento & purificación , Genes Virales , Glicosilación , Humanos , Virus Sincitiales Respiratorios/genética , Arabia Saudita
13.
Heliyon ; 10(7): e28350, 2024 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-38560213

RESUMEN

Respiratory tract infections due to a variety of viruses continue to threaten the human population worldwide, particularly in developing countries. Among the responsible viruses, Human Bocavirus (HBoV), a novel discovered virus, causes respiratory tract and gastroenteritis disorders in young children. In Saudi Arabia, data regarding virus molecular epidemiology and evolution and its implication in respiratory tract infection are scarce. In the current study, genetic diversity and circulation pattern of HBoV-1 among hospitalized children due to acute respiratory tract infection (ARTI) during two consecutive years were charted. We found that 3.44% (2014/2015) and 11.25% (2015/2016) of children hospitalized due to ARTI were infected by HBoV-1. We have shown that HBoV was detected year-round without a marked seasonal peak. HBoV-1 also was co-detected with one or multiple other respiratory viruses. The multisequence analysis showed high sequence identity (∼99%) (few point mutation sites) between strains of each genotype and high sequence variation (∼79%) between HBoV-1 and the other 3 genotypes. Phylogenetic analysis showed the clustering of the study's isolates in the HBoV-1 subclade. Our data reveal that genetically conserved HBoV-1 was circulating among admitted children during the course of the study. Further epidemiological and molecular characterization of multiple HBoV-1 strains for different years and from all regions of Saudi Arabia are required to understand and monitor the virus evolution.

14.
Tissue Eng Regen Med ; 2024 Jun 24.
Artículo en Inglés | MEDLINE | ID: mdl-38913224

RESUMEN

BACKGROUND: Skin alterations are among the most prominent signs of aging, and they arise from both intrinsic and extrinsic factors that interact and mutually influence one another. The use of D-galactose as an aging model in animals has been widely employed in anti-aging research. Adipose tissue-derived mesenchymal stem cells (Ad-MSCs) are particularly promising for skin anti-aging therapy due to their capacity for effective re-epithelization and secretion of various growth factors essential for skin regeneration. Accordingly, we aimed to examine the potential utility of Ad-MSCs as a therapy for skin anti-aging. METHODS: In this study, we isolated and characterized adipose-derived mesenchymal stem cells (Ad-MSCs) from the epididymal fat of male Sprague Dawley rats. We assessed the in vitro differentiation of Ad-MSCs into epidermal progenitor cells (EPCs) using ascorbic acid and hydrocoritsone. Additionally, we induced skin aging in female Sprague Dawley rats via daily intradermal injection of D-galactose over a period of 8 weeks. Then we evaluated the therapeutic potential of intradermal transplantation of Ad-MSCs and conditioned media (CM) derived from differentiated EPCs in the D-galactose-induced aging rats. Morphological assessments, antioxidant assays, and histopathological examinations were performed to investigate the effects of the treatments. RESULTS: Our findings revealed the significant capability of Ad-MSCs to differentiate into EPCs. Notably, compared to the group that received CM treatment, the Ad-MSCs-treated group exhibited a marked improvement in morphological appearance, antioxidant levels and histological features. CONCLUSIONS: These results underscore the effectiveness of Ad-MSCs in restoring skin aging as a potential therapy for skin aging.

15.
J Neurophysiol ; 110(7): 1535-43, 2013 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-23843437

RESUMEN

Cardiovascular adjustments to exercise are partially mediated by group III/IV (small to medium) muscle afferents comprising the exercise pressor reflex (EPR). However, this reflex can be inappropriately activated in disease states (e.g., peripheral vascular disease), leading to increased risk of myocardial infarction. Here we investigate the voltage-dependent calcium (CaV) channels expressed in small to medium muscle afferent neurons as a first step toward determining their potential role in controlling the EPR. Using specific blockers and 5 mM Ba(2+) as the charge carrier, we found the major calcium channel types to be CaV2.2 (N-type) > CaV2.1 (P/Q-type) > CaV1.2 (L-type). Surprisingly, the CaV2.3 channel (R-type) blocker SNX482 was without effect. However, R-type currents are more prominent when recorded in Ca(2+) (Liang and Elmslie 2001). We reexamined the channel types using 10 mM Ca(2+) as the charge carrier, but results were similar to those in Ba(2+). SNX482 was without effect even though ∼27% of the current was blocker insensitive. Using multiple methods, we demonstrate that CaV2.3 channels are functionally expressed in muscle afferent neurons. Finally, ATP is an important modulator of the EPR, and we examined the effect on CaV currents. ATP reduced CaV current primarily via G protein ßγ-mediated inhibition of CaV2.2 channels. We conclude that small to medium muscle afferent neurons primarily express CaV2.2 > CaV2.1 ≥ CaV2.3 > CaV1.2 channels. As with chronic pain, CaV2.2 channel blockers may be useful in controlling inappropriate activation of the EPR.


Asunto(s)
Canales de Calcio/metabolismo , Músculo Esquelético/inervación , Neuronas Aferentes/fisiología , Potenciales de Acción , Adenosina Trifosfato/farmacología , Animales , Bario/farmacología , Bloqueadores de los Canales de Calcio/farmacología , Canales de Calcio/clasificación , Canales de Calcio/genética , Línea Celular Tumoral , Ganglios Espinales/citología , Ganglios Espinales/fisiología , Humanos , Masculino , Músculo Esquelético/fisiología , Neuronas Aferentes/efectos de los fármacos , Neuronas Aferentes/metabolismo , Ratas , Ratas Sprague-Dawley , Reflejo
16.
RSC Adv ; 13(31): 21182-21189, 2023 Jul 12.
Artículo en Inglés | MEDLINE | ID: mdl-37456546

RESUMEN

Magnesium metal batteries attract great attention for their high volumetric capacity and safety as a post-lithium choice. The strategy of adding organic plasticizer may bring new insights into designing halogen-free electrolytes for the further development of magnesium-sulfur batteries. The high charge density of Mg2+ results in a high desolvation barrier and low interfacial Mg2+ transfer kinetics due to the strong coulombic interactions of Mg2+ ions with anions and solvent molecules. In this study, we test the effect of the stoichiometric ratio of ethylene carbonate (EC) as an organic additive on the electrochemical performance of halogen-free electrolyte (HFE) based on Mg(NO3)2 in acetonitrile (ACN) and tetraethylene glycol dimethyl ether (G4). Through various characterization methods, the introduction of EC perturbs the bonding scheme of the HFE electrolyte, enhances the ionic conductivity, reduces the relaxation time, and forms a resistive solid electrolyte interphase (SEI). The assembled Mg-S full cell using modified HFE (HFE_EC) delivers initial specific capacities of 900 m Ag-1 with a cycle life of up to 10 cycles in the case of activating the cell with electrochemical conditioning. This study sheds light on the interplay of EC and the interfacial kinetics in Mg batteries and opens a door for designing novel magnesium electrolytes.

17.
Am J Cancer Res ; 13(3): 727-757, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37034228

RESUMEN

Due to heterogenetic-specific nature of the available biomarkers, the incidence of lung adenocarcinoma (LUAD) is on the rise worldwide. Previously reported LUAD-related hub genes were searched from the medical literature via literature mining and were processed to identify few top genes via degree method. Later, a comprehensive in silico methodology was applied on the selected real hub genes to identify their tumor driving, diagnostic, and prognostic roles in LUAD patients with divers clinicopathological variables. Out of total 145 extracted hub genes, six genes including CDC6, PBK, AURKA, KIF2C, OIP5, and PRC1 were identified as real hub genes. The expression analysis showed that all these genes were significantly up-regulated across LUAD samples of different clinicopathological variables. In addition, a variety of unique correlations among the expression and of real hub genes and some other parameters including promoter methylation status, overall survival (OS), genetic changes, tumor purity, and immune cell infiltration have also been explored in the present study. Moreover, via TFS-miRNA-mRNA regulatory network, one important TF (E2F1) and one important miRNAs (hsa-mir-34a-5p) that targeted all the real hub genes were also identified. Finally, a variety of drugs also predicted to be very useful in treating LUAD. The discovery of the real hub genes, TFS-miRNA-mRNA network, and chemotherapeutic drugs associated with LUAD provides new insights into underlying mechanisms and treatment of LUAD overcoming heterogeneity barriers.

18.
Diagnostics (Basel) ; 12(4)2022 Apr 06.
Artículo en Inglés | MEDLINE | ID: mdl-35453960

RESUMEN

Currently, the standard assay employed to diagnose human orthopneumovirus infection is real-time reverse transcriptase PCR assay (rRT-PCR), a costly and time-consuming procedure that requires the manipulation of infectious viruses. In addition to RT-PCR, serological tests can complement the molecular diagnostic methods and have proven to be important tools in sero-surveillance. In this study, we report the development, optimization, and validation of a novel and rapid in-house diagnostic ELISA kit to detect human orthopneumovirus in clinical samples. We developed three sensitive ELISA formats through the immunization of rats with novel recombinant pPOE-F or pPOE-TF vectors. The two vectors expressed either the full-length (pPOE-F) or the truncated form (pPOE-TF) of the fusion (F) protein. The developed ELISA kits were optimized for coating buffer, capture antibody, blocking buffer, sample antigen, detection antibodies, and peroxidase-conjugated antibody, and validated using 75 rRT-PCR-confirmed nasopharyngeal aspirate (NPA) human orthopneumovirus samples and 25 negative samples collected from hospitalized children during different epidemic seasons between 2014 and 2017. Our results indicate that rats immunized with pPOE-F or pPOE-TF showed significant induction of high levels of MPAs. Validation of the ELISA method was compared to the rRT-PCR and the sensitivity hierarchy of these developed ELISA assays was considered from highest to lowest: indirect competitive inhibition ELISA (93.3%) > indirect antigen-capture ELISA (90.6%) > direct antigen-capture ELISA (86.6%). The development of the rapid in-house diagnostic ELISA kits described in this study demonstrates that a specific, rapid and sensitive test for human orthopneumovirus antigens could be successfully applied to samples collected from hospitalized children during different epidemics and can help in the efficient diagnosis of respiratory syncytial viral infections.

19.
Am J Transl Res ; 14(12): 8843-8861, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36628250

RESUMEN

OBJECTIVES: Cervical Squamous Cell Carcinoma (CESC) is one of the most fatal female malignancies, and the underlying molecular mechanisms governing this disease have not been fully explored. In this research, we planned to conduct the analysis of Gene Expression Omnibus (GEO) cervical squamous cell carcinoma microarray datasets by a detailed in silico approach and to explore some novel biomarkers of CESC. METHODS: The top commonly differentially expressed genes (DEGs) from the GSE138080 and GSE113942 datasets were analyzed by Limma package-based GEO2R tool. The protein-protein interaction (PPI) network of the DEGs was drawn through Search Tool for the Retrieval of Interacting Genes (STRING), and top 6 hub genes were obtained from Cytoscape. Expression analysis and validation of hub genes expression in CESC samples and cell lines were done using UALCAN, OncoDB, GENT2, and HPA. Additionally, cBioPortal, Gene set enrichment analysis (GSEA) tool, Kaplan-Meier (KM) plotter, ShinyGO, and DGIdb databases were also used to check some important values of hub genes in CESC. RESULTS: Out of 79 DEGs, the minichromosome maintenance complex component 4 (MCM4), nucleolar and spindle-associated protein 1 (NUSAP1), cell division cycle associated 5 (CDCA5), cell division cycle 45 (CDC45), denticleless E3 ubiquitin protein ligase homolog (DTL), and chromatin licensing and DNA replication factor 1 (CDT1) genes were regarded as hub genes in CESC. Further analysis revealed that the expressions of all these hub genes were significantly elevated in CESC cell lines and samples of diverse clinical attributes. In this study, we also documented some important correlations between hub genes and some other diverse measures, including DNA methylation, genetic alterations, and Overall Survival (OS). Last, we also identify hub genes associated ceRNA network and 31 important chemotherapeutic drugs. CONCLUSION: Through detailed in silico methodology, we identified 6 hub genes, including MCM4, NUSAP1, CDCA5, CDC45, DTL, and CDT1, which are likely to be associated with CESC development and diagnosis.

20.
Viruses ; 14(12)2022 11 22.
Artículo en Inglés | MEDLINE | ID: mdl-36560596

RESUMEN

With the emergence of SARS-CoV-2, routine surveillance combined with sequence and phylogenetic analysis of coronaviruses is urgently required. In the current study, the four common human coronaviruses (HCoVs), OC43, NL63, HKU1, and 229E, were screened in 361 clinical samples collected from hospitalized children with respiratory symptoms during four winter seasons. RT-PCR-based detection and typing revealed different prevalence rates of HCoVs across the four seasons. Interestingly, none of the four HCoVs were detected in the samples (n = 100) collected during the winter season of the COVID-19 pandemic. HCoV-OC43 (4.15%) was the most frequently detected, followed by 229E (1.1%). Partial sequences of S and N genes of OC43 from the winter seasons of 2015/2016 and 2021/2022 were used for sequence and phylogenetic analysis. Multiple sequence alignment of the two Saudi OC43s strains with international strains revealed the presence of sequence deletions and several mutations, of which some changed their corresponding amino acids. Glycosylation profiles revealed a number of O-and N-glycosylation sites in both genes. Based on phylogenetic analysis, four genotypes were observed with Riyadh strains grouped into the genotype C. Further long-term surveillance with a large number of clinical samples and sequences is necessary to resolve the circulation patterns and evolutionary kinetics of OC43 in Saudi Arabia.


Asunto(s)
COVID-19 , Coronavirus Humano OC43 , Infecciones del Sistema Respiratorio , Humanos , Niño , Filogenia , Coronavirus Humano OC43/genética , Arabia Saudita/epidemiología , Prevalencia , Pandemias , COVID-19/epidemiología , SARS-CoV-2/genética , Estaciones del Año
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA