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1.
Mol Oral Microbiol ; 2024 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-38511906

RESUMO

BACKGROUND: Considered the second largest and most diverse microbiome after the gut, the human oral ecosystem is complex with diverse and niche-specific microorganisms. Although evidence is growing for the importance of oral microbiome in supporting a healthy immune system and preventing local and systemic infections, the influence of craniomaxillofacial (CMF) trauma and routine reconstructive surgical treatments on community structure and function of oral resident microbes remains unknown. CMF injuries affect a large number of people, needing extensive rehabilitation with lasting morbidity and loss of human productivity. Treatment efficacy can be complicated by the overgrowth of opportunistic commensals or multidrug-resistant pathogens in the oral ecosystem due to weakened host immune function and reduced colonization resistance in a dysbiotic oral microbiome. AIMS: To understand the dynamics of microbiota's community structure during CMF injury and subsequent treatments, we induced supra-alveolar mandibular defect in Hanford miniature swine (n = 3) and compared therapeutic approaches of immediate mandibullar reconstructive (IMR) versus delayed mandibullar reconstructive (DMR) surgeries. METHODS: Using bacterial 16S ribosomal RNA gene marker sequencing, the composition and abundance of the bacterial community of the uninjured maxilla (control) and the injured left mandibula (lingual and buccal) treated by DMR were surveyed up to 70-day post-wounding. For the injured right mandibula receiving IMR treatment, the microbial composition and abundance were surveyed up to 14-day post-wounding. Moreover, we measured sera level of biochemical markers (e.g., osteocalcin) associated with bone regeneration and healing. Computed tomography was used to measure and compare mandibular bone characteristics such as trabecular thickness between sites receiving DMR and IMR therapeutic approaches until day 140, the end of study period. RESULTS: Independent of IMR versus DMR therapy, we observed similar dysbiosis and shifts of the mucosal bacteria residents after CMF injury and/or following treatment. There was an enrichment of Fusobacterium, Porphyromonadaceae, and Bacteroidales accompanied by a decline in Pasteurellaceae, Moraxella, and Neisseria relative abundance in days allotted for healing. We also observed a decline in species richness and abundance driven by reduction in temporal instability and inter-animal heterogeneity on days 0 and 56, with day 0 corresponding to injury in DMR group and day 56 corresponding to delayed treatment for DMR or injury and immediate treatment for the IMR group. Analysis of bone healing features showed comparable bone-healing profiles for IMR vs. DMR therapeutic approach.

2.
Elife ; 122024 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-38391176

RESUMO

Neuroblasts in Drosophila divide asymmetrically, sequentially expressing a series of intrinsic factors to generate a diversity of neuron types. These intrinsic factors known as temporal factors dictate timing of neuroblast transitions in response to steroid hormone signaling and specify early versus late temporal fates in neuroblast neuron progeny. After completing their temporal programs, neuroblasts differentiate or die, finalizing both neuron number and type within each neuroblast lineage. From a screen aimed at identifying genes required to terminate neuroblast divisions, we identified Notch and Notch pathway components. When Notch is knocked down, neuroblasts maintain early temporal factor expression longer, delay late temporal factor expression, and continue dividing into adulthood. We find that Delta, expressed in cortex glia, neuroblasts, and after division, their GMC progeny, regulates neuroblast Notch activity. We also find that Delta in neuroblasts is expressed high early, low late, and is controlled by the intrinsic temporal program: early factor Imp promotes Delta, late factors Syp/E93 reduce Delta. Thus, in addition to systemic steroid hormone cues, forward lineage progression is controlled by local cell-cell signaling between neuroblasts and their cortex glia/GMC neighbors: Delta transactivates Notch in neuroblasts bringing the early temporal program and early temporal factor expression to a close.


Assuntos
Proteínas de Drosophila , Drosophila , Animais , Drosophila/genética , Proteínas de Drosophila/metabolismo , Neurogênese/genética , Hormônios/metabolismo , Esteroides/metabolismo , Drosophila melanogaster/genética , Regulação da Expressão Gênica no Desenvolvimento
3.
Heliyon ; 9(12): e22341, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38076159

RESUMO

The significant increase in energy consumption has facilitated a rapid increase in offensive greenhouse gas (GHG) and CO2 emissions. The consequences of such emissions are one of the most pivotal concerns of environmental scientists. To protect the environment, they are conducting the necessary research to protect the environment from the greenhouse effect. Among the different sources of CO2 emission, power plants contribute the largest amount of CO2 and as the number of power plants around the world is rising gradually due to increasing energy demand, the amount of CO2 emission is also rising subsequently. Researchers have developed different potential technologies to capture post-combustion CO2 capture from powerplants among which membrane-based, cryogenic, absorption and adsorption-based CO2 processes have gained much attention due to their applicability at the industrial level. In this work, adsorption-based CO2 technologies are comprehensively reviewed and discussed to understand the recent advancements in different adsorption technologies and several adsorbent materials. Researchers and scientists have developed and advanced different adsorption technologies including vacuum swing adsorption, temperature swing adsorption, pressure swing adsorption, and electric swing adsorption, etc. To further improve the CO2 adsorption capacity with a compact CO2 adsorption unit, researchers have integrated different adsorption technologies to investigate their performance, such as temperature vacuum swing adsorption, pressure vacuum swing adsorption, electric temperature pressure swing adsorption, etc. Different adsorbent materials have been tested to evaluate their applicability for CO2 adsorption and among these adsorbents, advanced carbonaceous, non-carbonaceous, polymeric, and nanomaterials have achieved much attention due to their suitable characteristics that are required for adsorbing CO2. Researchers have reported that higher CO2 adsorption capacity can be achieved by integrating different adsorption technologies and employing suitable adsorbent material for that system. This comprehensive review also provides future directions that may assist researchers in developing novel adsorbent materials and gaining a proper understanding of the selection criteria for effective CO2 adsorption processes with suitable adsorbents.

4.
bioRxiv ; 2023 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-37034719

RESUMO

Neuroblasts in Drosophila divide asymmetrically, sequentially expressing a series of intrinsic factors to generate a diversity of neuron types. These intrinsic factors known as temporal factors dictate timing of neuroblast transitions in response to steroid hormone signaling and specify early versus late temporal fates in neuroblast neuron progeny. After completing their temporal programs, neuroblasts differentiate or die, finalizing both neuron number and type within each neuroblast lineage. From a screen aimed at identifying genes required to terminate neuroblast divisions, we identified Notch and Notch pathway components. When Notch is knocked down, neuroblasts maintain early temporal factor expression longer, delay late temporal factor expression, and continue dividing into adulthood. We find that Delta, expressed in cortex glia, neuroblasts, and after division, their GMC progeny, regulates neuroblast Notch activity. We also find that Delta in neuroblasts is expressed high early, low late, and is controlled by the intrinsic temporal program: early factor Imp promotes Delta, late factors Syp/E93 reduce Delta. Thus, in addition to systemic steroid hormone cues, forward lineage progression is controlled by local cell-cell signaling between neuroblasts and their cortex glia/GMC neighbors: Delta transactivates Notch in neuroblasts bringing the early temporal program and early temporal factor expression to a close.

5.
J Oleo Sci ; 71(5): 685-692, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35491094

RESUMO

This paper presents a feasible and reliable phase transfer protocol for polyoxyethylene alkyl amine surfactant (AMIET)-coated gold nanoparticles (AuNPs) in aqueous media to chloroform using a pH-triggered method, through the liquid-liquid interface. In the initial stage, the colloidal aqueous dispersion is destabilized by pH adjustment towards the isoelectric pH of the nanoparticle, which promotes the separation of the particles from water. We further explored a mechanistic view of this phase transfer phenomenon, considering the orientation of hydrophilic and hydrophobic moieties depending on the nature of the surrounding solvent. It was proposed that the AMIET molecules bound to the AuNPs undergo conformational changes through phase transfer. Ultraviolet visible absorption spectra before and after the phase transfer reveal that the original morphology and dispersion states of the particles were preserved.


Assuntos
Ouro , Nanopartículas Metálicas , Ouro/química , Interações Hidrofóbicas e Hidrofílicas , Nanopartículas Metálicas/química , Solventes/química , Água/química
6.
Access Microbiol ; 4(12): acmi000410, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36644734

RESUMO

Introduction: Haemophilus species are gram-negative, non-motile, facultative anaerobic coccobacilli in the larger family of Pasteurellaceae . Implicated in a variety of human diseases, Haemophilus species are also included in the 'HACEK' group of organisms, which are fastidious gram-negative bacteria, a well-described but uncommon cause of endocarditis. Among the Haemophilus species responsible for endocarditis, Haemophilus parainfluenzae is the most frequently isolated. However, novel species of Haemophilus have recently been described, and their clinical significance remains uncertain. Case presentation: A 35-year-old man was admitted to the hospital after presenting with a 3 month history of nightly fevers, night sweats and unintentional weight loss, with a new murmur detected on cardiac auscultation. Blood cultures returned positive for Haemophilus sputorum identified by matrix assisted laser desorption ionization - time of flight MS, and confirmed with whole genome sequencing. Echocardiography revealed the presence of an aortic valve vegetation, with aortic and mitral valve leaflet perforations. He was successfully treated with surgical bioprosthetic valve replacements and pathogen-directed antibiotics without complications. Conclusion: We describe a case of infective endocarditis due to H. sputorum , a newly identified Haemophilus species, which to the best of our knowledge has yet to be reported, and discuss the available literature regarding this organism.

7.
J Patient Exp ; 8: 2374373521997735, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34179391

RESUMO

Transmission of coronavirus (COVID-19) is a considerable risk during the perioperative period of emergency surgery. A prospective observational study was performed between March 30, 2020, and June 30, 2020, at a large District General Hospital in England. The primary outcome was perioperative COVID-19-related complications, and secondary outcome measures included incidence of COVID-19 infections among the acute surgical patients, doctors, and healthcare workers. A total of 584 patients admitted through the emergency surgical pathway and 43% (n = 253) underwent surgical intervention. Approximately 5% (n = 30) patients contracted COVID-19 during the perioperative period and 6 of them died. Eight surgical doctors and 11 theater staff were confirmed for COVID-19 by swab test. Acute surgical emergencies and perioperative management of the urgent surgical patients during the COVID-19 pandemic is a global challenge, but adequate preparedness and strategic plan to adjust the surgical services can reduce the exposures to this highly contagious virus.

8.
Infect Drug Resist ; 14: 1-10, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33442271

RESUMO

PURPOSE: The biology of chronic wounds is complex and many factors act concurrently to impede healing progress. In this study, the dynamics of microflora changes and their antibiotic susceptibility patterns were evaluated longitudinally over 30 days using data from 28 patients with a total of 47 chronic lower extremity wounds. MATERIALS AND METHODS: In this study, colonized wound isolates were characterized using cultural, biochemical, and VITEK 2 methods. Antibiotic susceptibility patterns of the wound isolates were analyzed using various phenotypic assays. Furthermore, antimicrobial resistance patterns and the presence of mutations were evaluated by a genotypic assay, whole-genome sequencing (WGS). RESULTS: Staphylococcus aureus and Pseudomonas aeruginosa were found to be the most common strains at early time points, while members of Enterobacteriaceae were prevalent at later stages of infection. Antimicrobial resistance testing and whole-genome sequencing revealed that the molecular and phenotypic characteristics of the identified wound pathogens remained relatively stable throughout the study period. It was also noted that Enterobacter and Klebsiella species may serve as reservoirs for quinolone resistance in the Pacific region. CONCLUSION: Our observations showed that wounds were colonized with diverse bacteria and interestingly their numbers and/or types were changed over the course of infection. The rapid genetic changes that accompanied the first 4 weeks after presentation did not directly contribute to the development of antibiotic resistance. In addition, standard wound care procedures did not appear to select for resistant bacterial strains. Future efforts should focus on defining those genetic changes associated with the wound colonizing microorganisms that occur beyond 4 weeks.

9.
Results Appl Math ; 10: 100145, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-38620615

RESUMO

In this study based on Bangladesh, a modified SIR model is produced and analysed for COVID-19. We have theoretically investigated the model along with numerical simulations. The reproduction number (R0) has been calculated by using the method of the next-generation matrix. Due to the basic reproduction number, we have analysed the local stability of the model for disease-free and endemic equilibria. We have investigated the sensitivity of the reproduction number to parameters and calculate the sensitivity indices to determine the dominance of the parameters. Furthermore, we simulate the system in MATLAB by using the fourth-order Runge-Kutta (RK4) method and validate the results using fourth order polynomial regression (John Hopkins Hospital (JHH), 2020). Finally, the numerical simulation depicts the clear picture of the upward, and the downward trend of the spread of this disease along with time in a particular place, and the parameters in the mathematical model indicate this change of intensity. This result represents, the effect of COVID-19 from Bangladesh's perspective.

10.
J Microbiol Methods ; 169: 105833, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31904440

RESUMO

Virulence is the relative capacity of a pathogenic microorganism to cause damage in susceptible host cells such as those found in airway passages and the gut. In this study, the effect of clinical bacterial isolates on the monolayer integrity of cultured human alveolar basal epithelial cells (A549) was evaluated using the Electric Cell-Substrate Impedance Sensing (ECIS) system. ECIS is a morphological biosensor which records electrical properties of cell-covered microelectrodes in an AC circuit including impedance (ohm), resistance (ohm), and capacitance (µFarad). In the current study, fluctuations in the electrical properties of cell-covered microelectrodes reflect dynamic changes in cell morphology resulting from disrupted cell monolayers following exposure to bacteria. Using the ECIS system, real-time changes of cell morphology and disruption of monolayer integrity of cell-cultures in vitro were revealed for A549 cells infected with either Pseudomonas aeruginosa, ESBL Escherichia coli, Staphylococcus aureus (MRSA), or Enterococcus (VRE). We determined empirically that the optimal signal response was obtained for resistance (ohm) measurements at 4000 hertz. Following infection of A549 cells, the data revealed that Pseudomonas aeruginosa resulted in little change in microelectrode resistance (ohm @4 kHz) as compared to pathogen-free controls within the first 12 h. In contrast, E. coli, MRSA, and VRE caused significant changes in electrode resistance (ohm @4 kHz) values in the infected cells compared to controls over the first 5 h. Resistance (ohm @4 kHz) changes were also observed in cell monolayers infected with different bacterial concentrations for all isolates over 24 h. The highest concentration of bacteria caused the measured resistance (ohm @4 kHz) to drop faster than its' immediate lower concentration, suggesting a dose-dependent effect. Compared to live bacteria, cells exposed to heat-killed bacteria did not show significant changes in resistance (ohm @4 kHz) over 48 h post-exposure. Functionally, cytokine responses were different between cells treated with live and heat-killed bacteria. Of note, live bacteria induced IFNγ, IL-13, and IL-1ß production in A549 cells, whereas heat-killed bacteria induced IL-8 production suggesting a differential interaction with cells that could reveal the underlying causes of resistance (ohm @4 kHz) changes. Our findings indicate that ECIS provides a means to quantify, automate, and measure bacterial virulence, which may have broader implications governing the course of treatment compared to traditional methods alone.


Assuntos
Bactérias/metabolismo , Fenômenos Fisiológicos Celulares/fisiologia , Impedância Elétrica , Células Epiteliais/microbiologia , Células A549 , Técnicas Biossensoriais/métodos , Linhagem Celular , Citocinas/metabolismo , Enterococcus/isolamento & purificação , Enterococcus/metabolismo , Enterococcus/patogenicidade , Escherichia coli/isolamento & purificação , Escherichia coli/metabolismo , Escherichia coli/patogenicidade , Humanos , Microeletrodos , Pseudomonas aeruginosa/isolamento & purificação , Pseudomonas aeruginosa/metabolismo , Pseudomonas aeruginosa/patogenicidade , Staphylococcus aureus/isolamento & purificação , Staphylococcus aureus/metabolismo , Staphylococcus aureus/patogenicidade , Junções Íntimas/microbiologia
11.
BMJ Case Rep ; 12(7)2019 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-31300606

RESUMO

De Garengeot hernia describes a rare phenomenon in which a vermiform appendix is found in a femoral hernia sac. We describe a case of De Garengeot hernia presenting as a groin lump associated with loss of appetite, weight loss and fatigue. A 72-year-old woman was referred to our rapid access 2-week clinic as isolated lymphadenopathy with a 4-week history of a gradual right groin swelling accompanied by an unintentional weight loss, lethargy and anorexia. An urgent excisional lymph node biopsy was performed preceding the CT scan of the chest, abdomen and pelvis. The biopsy showed a shaving of appendix wall, and the CT scan revealed a right-sided femoral hernia with appendix as its content. The patient was urgently contacted for a laparoscopic appendicectomy and an open right femoral hernia repair. The patient recovered well postoperatively, and her systemic symptoms fully resolved when reviewed 10 weeks after the operation.


Assuntos
Apêndice/patologia , Virilha/patologia , Hérnia Femoral/diagnóstico , Linfadenopatia/patologia , Tomografia Computadorizada por Raios X , Idoso , Apendicectomia , Apêndice/diagnóstico por imagem , Fadiga , Feminino , Virilha/diagnóstico por imagem , Hérnia Femoral/cirurgia , Herniorrafia , Humanos , Doenças Raras , Resultado do Tratamento , Redução de Peso
12.
J Emerg Nurs ; 45(2): 169-177.e1, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30573161

RESUMO

INTRODUCTION: The emergency department is a fast-paced, high-volume environment, serving patients with diverse and evolving acuities. Personnel providing direct care are continually exposed to pathogenic microorganisms from patients and everyday surfaces, to which the organisms may spread. Indeed, hospital items-such as electronic devices, stethoscopes, and staff clothing-have demonstrated high rates of contamination. Despite this, policies governing the use, disinfection, and wear of various environmental surfaces remain relaxed, vague, and/or difficult to enforce. This study aimed to examine the bacterial contamination on 2 hospital uniform types in a large military hospital within the emergency department. METHODS: Environmental sampling of military and civilian nursing staff uniforms was performed on 2 separate occasions. Emergency nurses wore hospital-provided freshly laundered scrubs on the first sampling day and home-laundered personally owned uniforms complicit with ED policy on the second sampling day. Samples were collected by impressing of contact blood agar growth medium at arrival (0 hour), 4 hours, and 8 hours of wear. Microbiological methods were used to enumerate and identify bacterial colonies. RESULTS: Bacterial contamination of personally owned uniforms was significantly higher than freshly laundered hospital-provided scrubs on 4 different sampling sites and across the span of an 8-hour workday. No significant differences were observed between military and civilian personally owned uniforms. However, several risk factors for nosocomial infection were increased in the military subgroup. DISCUSSION: Re-evaluating organizational factors (such as uniform policies) that increase the propensity for pathogenic contamination are critical for mitigating the spread and acquisition of multidrug-resistant organisms in the emergency department.


Assuntos
Vestuário , Infecção Hospitalar/microbiologia , Serviço Hospitalar de Emergência , Contaminação de Equipamentos/estatística & dados numéricos , Hospitais Militares , Recursos Humanos de Enfermagem Hospitalar , Adulto , Estudos Cross-Over , Feminino , Humanos , Controle de Infecções , Masculino , Pessoa de Meia-Idade , Militares
13.
Infect Control Hosp Epidemiol ; 39(11): 1316-1321, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30156175

RESUMO

OBJECTIVE: To compare bacterial contamination of military-approved uniforms and hospital-provided scrubs donned by nursing staff in an inpatient setting. DESIGN: Randomized experimental crossover study. SETTING: Large academic military medical center. METHODS: Inpatient units were randomized to predetermine the order of uniform sampling. Participants included nursing staff who provided direct patient care across 7 eligible inpatient units. Sampling of 6 designated sites on the uniform was completed on arrival to work, at ~4 hours into their shift, and at the 8-hour time point, for a total of 18 samples. Sampling of each participant occurred on 2 separate occasions, once in a military-approved uniform, and once in hospital-provided scrubs. After 24 hours of incubation, a colony-counting machine was used to calculate the total colony-forming units (CFU) of the sample. RESULTS: Across all time points, military-approved uniforms demonstrated a 2-fold bacterial increase at the abdominal site and 3-fold increases at the sleeve cuff and waist pocket regions compared to the same regions on hospital-provided scrubs. CONCLUSION: Nurses should be aware that bacteria are present at much higher levels on their personal military uniforms compared to hospital-provided scrubs. Additional research is needed to determine whether these findings are a function of wear, laundering, or environmental factors. Nurses should adhere to daily uniform washing to reduce bacterial load and minimize risk of nosocomial infections to the patients they care for.


Assuntos
Infecção Hospitalar/microbiologia , Contaminação de Equipamentos/estatística & dados numéricos , Hospitais Militares , Recursos Humanos de Enfermagem Hospitalar , Roupa de Proteção/microbiologia , Adulto , Carga Bacteriana/métodos , Contagem de Colônia Microbiana/métodos , Estudos Cross-Over , Feminino , Humanos , Controle de Infecções , Masculino , Militares , Assistência ao Paciente , Adulto Jovem
14.
Sci Rep ; 8(1): 11736, 2018 08 06.
Artigo em Inglês | MEDLINE | ID: mdl-30082843

RESUMO

Hawaii has one of the highest incidences of Campylobacteriosis in the United States, but there remains little published data on circulating strains or antimicrobial resistance. We characterized 110 clinical Campylobacter isolates (106 C. jejuni, 4 C. coli) processed at Tripler Army Medical Center in Honolulu, HI from 2012-2016. Twenty-five percent of C. jejuni isolates exhibited fluoroquinolone (FQ) resistance, compared with 16% for tetracycline (TET), and 0% for macrolides. Two of the four C. coli isolates were resistant to FQ, TET, and macrolides. C. jejuni isolates further underwent multilocus sequence typing, pulsed-field gel electrophoresis, and molecular capsular typing. Nineteen capsule types were observed, with two capsule types (HS2 and HS9) being associated with FQ resistance (p < 0.001 and p = 0.006, respectively). HS2 FQ-resistant isolates associated with clonal complex 21, possibly indicating clonal spread in FQ resistance. Macrolides should be considered for treatment of suspect cases due to lack of observed resistance.


Assuntos
Campylobacter/efeitos dos fármacos , Adulto , Antibacterianos/farmacologia , Campylobacter/genética , Infecções por Campylobacter/prevenção & controle , Farmacorresistência Bacteriana/genética , Eletroforese em Gel de Campo Pulsado , Feminino , Fluoroquinolonas/farmacologia , Havaí , Humanos , Macrolídeos/farmacologia , Masculino , Tipagem de Sequências Multilocus , Estudos Retrospectivos , Tetraciclina/farmacologia , Adulto Jovem
15.
Artigo em Inglês | MEDLINE | ID: mdl-28070309

RESUMO

BACKGROUND: Bloodstream infections due to bacterial pathogens are a major cause of morbidity and mortality in Bangladesh and other developing countries. In these countries, most patients are treated empirically based on their clinical symptoms. Therefore, up to date etiological data for major pathogens causing bloodstream infections may play a positive role in better healthcare management. The aim of this study was to identify the bacterial pathogens causing major bloodstream infections in Dhaka, Bangladesh and determine their antibiotic susceptibility pattern. METHODS: From January 2005 to December 2014, a total of 103,679 single bottle blood samples were collected from both hospitalized and domiciliary patients attending Dhaka hospital, icddrb, Bangladesh All the blood samples were processed for culture using a BACT/Alert blood culture machine. Further identification of bacterial pathogens and their antimicrobial susceptibility test were performed using standard microbiological procedures. RESULTS: Overall, 13.6% of the cultured blood samples were positive and Gram-negative (72.1%) bacteria were predominant throughout the study period. Salmonella Typhi was the most frequently isolated organism (36.9% of samples) in this study and a high percentage of those strains were multidrug-resistant (MDR). However, a decreasing trend in the S. Typhi isolation rate was observed and, noticeably, the percentage of MDR S. Typhi isolated declined sharply over the study period. An overall increase in the presence of Gram-positive bacteria was observed, but most significantly we observed the percentage of MDR Gram-positive bacteria to double over the study period. Overall, Gram positive bacteria were more resistant to most of the commonly used antibiotics than Gram-negative bacteria, but the MDR level was high in both groups. CONCLUSIONS: This study identified the major bacterial pathogens involved with BSI in Dhaka, Bangladesh and also revealed their antibiotic susceptibility patterns. We expect our findings to help healthcare professionals to make informed decisions and provide better care for their patients. Also, we hope this study will assist researchers and policy makers to prioritize their research options to face the future challenges of infectious diseases.

16.
J Innate Immun ; 7(4): 428-40, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25896300

RESUMO

Unwarranted overproduction of cytokines, such as interleukin (IL)-1ß, can cause moderate to severe pathological complications, and thus elaborate mechanisms are needed to regulate its onset and termination. One such, well-known, mechanism is endotoxin tolerance, generally described as controlling lipopolysaccharide Toll-like receptor 4 (LPS-TLR4) signaling. Similarly, cytokine-induced tolerance plays an important role in regulating an overactive cytokine response. In this report, the capability of IL-1ß to induce tolerance and cross-tolerance to various inflammatory ligands was investigated. IL-1ß-stimulated THP-1 monocytes showed a gradual increase of microRNA (miR)-146a, reaching 15-fold expression by 24 h. miR-146a upregulation induced tolerance toward subsequent challenges of IL-1ß, LPS, peptidoglycan, Pam and flagellin in THP-1 cells. The induction of tolerance was dependent on the IL-1ß priming dose and associated increase of miR-146a expression. Moreover, IL-1ß-treated THP-1 cells showed sustained miR-146a upregulation that repressed IRAK1 and TRAF6 adaptor molecules. Transfection of miR-146a alone mimicked IL-1ß-induced tolerance in monocytes, while cells transfected with miR-146a inhibitor increased chemokine production. A comparable cytokine response regulated by miR-146a was also detected in lung epithelial A549 cells, purified human monocytes and mouse peritoneal macrophages. Thus, our studies showed that miR-146a was crucial for monocytic cell-based IL-1ß tolerance and cross-tolerance, and thus opens the way for future research in the development of therapeutics for inflammatory diseases.


Assuntos
Tolerância Imunológica , Interleucina-1beta/imunologia , Macrófagos Peritoneais/imunologia , MicroRNAs/imunologia , Receptores Toll-Like/imunologia , Animais , Linhagem Celular Tumoral , Humanos , Quinases Associadas a Receptores de Interleucina-1/genética , Quinases Associadas a Receptores de Interleucina-1/imunologia , Interleucina-1beta/genética , Camundongos , MicroRNAs/genética , Fator 6 Associado a Receptor de TNF/genética , Fator 6 Associado a Receptor de TNF/imunologia , Receptores Toll-Like/genética
17.
J Immunol ; 190(3): 1250-63, 2013 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-23264652

RESUMO

Innate immune response is the first defense against pathogens via recognition by various conserved pattern recognition receptors, such as TLRs, to initiate a rapid and strong cytokine alarm. TLR signaling-mediated cytokine production must be properly regulated to prevent pathological conditions deriving from overproduction of cytokines. In this study, the role of specific microRNAs in TLR-signaling pathway was investigated to reveal the cross-interaction and -regulation in the MyD88 pathway. In peptidoglycan (PGN)/TLR2-stimulated THP-1 monocytes, PBMCs, and primary macrophages showed rapid and dramatic miR-132 and miR-212 (miR-132/-212) upregulation. This newly identified response appeared earlier in time than the characteristic miR-146a response in LPS-TLR4 stimulation. The rapid induction of miR-132/-212 was transcription factor CREB dependent, and the sustained expression of miR-132/-212 was responsible for inducing tolerance to subsequent PGN challenge. Cross-tolerance was observed by TLR5 ligand flagellin and heat-killed or live bacteria resulting from miR-132/-212 upregulation. Mechanistically, IRAK4 was identified and validated as a target of miR-132/-212 by luciferase reporter assay and seed-sequence mutagenesis of the reporter. Transfection of miR-132 or miR-212 alone mimicked PGN tolerance in monocytes, whereas transfected specific miRNA inhibitors tampered the tolerance effect. During bacterial infection, PGN-mediated TLR2 signaling induces miR-132/-212 to downregulate IRAK4, an early component in the MyD88-dependent pathway, whereas LPS/TLR4-induced miR-146a downregulates downstream components of the same MyD88-dependent pathway. The identification of miR-132/-212 and miR-146a together to prevent damaging consequences from the overproduction of proinflammatory cytokines by targeting a common signaling pathway is significant and will provide insights into future design and development of therapeutics.


Assuntos
Tolerância Imunológica/imunologia , Quinases Associadas a Receptores de Interleucina-1/imunologia , Macrófagos Peritoneais/imunologia , MicroRNAs/imunologia , Monócitos/imunologia , Peptidoglicano/imunologia , Transdução de Sinais/imunologia , Receptor 2 Toll-Like/imunologia , Animais , Proteínas de Bactérias/imunologia , Células Cultivadas/imunologia , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/imunologia , Feminino , Flagelina/imunologia , Flagelina/farmacologia , Regulação da Expressão Gênica , Genes Reporter , Lipopolissacarídeos/imunologia , Lipoproteínas/farmacologia , Ativação de Macrófagos , Camundongos , Camundongos Endogâmicos C57BL , MicroRNAs/antagonistas & inibidores , MicroRNAs/biossíntese , MicroRNAs/genética , Fator 88 de Diferenciação Mieloide/imunologia , RNA Interferente Pequeno/farmacologia , Fator de Necrose Tumoral alfa/metabolismo
18.
Vet Immunol Immunopathol ; 144(3-4): 255-8, 2011 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-22041600

RESUMO

The reactivity of different lectins with crude chromogranin A (CgA) obtained from different animals, namely, cow, horse, dog, pig, and dolphin, was examined to identify lectin(s) that would be useful as coating reagent(s) in a sandwich enzyme-linked immunosorbent assay (ELISA). Of the different lectins studied, the Amaranthus caudatus lectin (ACA), which is specific for the Thomsen-Friedenreich (T)-antigen (Galß1-3GalNAc), was found to react with the CgA from different animals by western blotting. Purified rabbit anti-bovine CgA antibody was also found to cross-react with the crude CgA preparations. On the basis of these findings, a sandwich ELISA was developed with ACA as the coating reagent and anti-bovine CgA antibody as the probing antibody. Using this method, concentration-dependent curves ranging from 0.003 µg/mL to 25 µg/mL and from 0.02 µg/mL to 25 µg/mL were obtained for bovine CgA and canine CgA, respectively. Similarly, concentration-dependent curves were obtained for the equine, swine, and dolphin crude CgA extracts. Thus, ACA is concluded to be a valuable reagent for CgA detection in crude extracts from different animal species, and for CgA isolation/purification.


Assuntos
Glândulas Suprarrenais/química , Amaranthus/imunologia , Antígenos Glicosídicos Associados a Tumores/imunologia , Cromogranina A/análise , Ensaio de Imunoadsorção Enzimática/métodos , Lectinas de Plantas/imunologia , Animais , Western Blotting , Bovinos , Cromogranina A/imunologia , Cães , Golfinhos , Eletroforese em Gel de Poliacrilamida , Cavalos , Coelhos/imunologia , Suínos , Extratos de Tecidos/química
19.
Cell Mol Immunol ; 8(5): 388-403, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21822296

RESUMO

Toll-like receptors (TLRs) in innate immune cells are the prime cellular sensors for microbial components. TLR activation leads to the production of proinflammatory mediators and thus TLR signaling must be properly regulated by various mechanisms to maintain homeostasis. TLR4-ligand lipopolysaccharide (LPS)-induced tolerance or cross-tolerance is one such mechanism, and it plays an important role in innate immunity. Tolerance is established and sustained by the activity of the microRNA miR-146a, which is known to target key elements of the myeloid differentiation factor 88 (MyD88) signaling pathway, including IL-1 receptor-associated kinase (IRAK1), IRAK2 and tumor-necrosis factor (TNF) receptor-associated factor 6 (TRAF6). In this review, we comprehensively examine the TLR signaling involved in innate immunity, with special focus on LPS-induced tolerance. The function of TLR ligand-induced microRNAs, including miR-146a, miR-155 and miR-132, in regulating inflammatory mediators, and their impact on the immune system and human diseases, are discussed. Modulation of these microRNAs may affect TLR pathway activation and help to develop therapeutics against inflammatory diseases.


Assuntos
Endotoxinas/farmacologia , Regulação da Expressão Gênica/imunologia , Tolerância Imunológica/genética , Imunidade Inata , MicroRNAs/imunologia , Transdução de Sinais/imunologia , Animais , Bactérias/crescimento & desenvolvimento , Infecções Bacterianas/imunologia , Infecções Bacterianas/microbiologia , Citocinas/genética , Citocinas/imunologia , Citocinas/metabolismo , Endotoxinas/imunologia , Humanos , Doenças do Sistema Imunitário/genética , Quinases Associadas a Receptores de Interleucina-1/genética , Quinases Associadas a Receptores de Interleucina-1/imunologia , Quinases Associadas a Receptores de Interleucina-1/metabolismo , Camundongos , MicroRNAs/genética , MicroRNAs/metabolismo , Fator 88 de Diferenciação Mieloide/genética , Fator 88 de Diferenciação Mieloide/imunologia , Fator 88 de Diferenciação Mieloide/metabolismo , Ratos , Transdução de Sinais/genética , Fator 6 Associado a Receptor de TNF/genética , Fator 6 Associado a Receptor de TNF/imunologia , Fator 6 Associado a Receptor de TNF/metabolismo , Receptor 4 Toll-Like/genética , Receptor 4 Toll-Like/imunologia , Receptor 4 Toll-Like/metabolismo
20.
Arthritis Res Ther ; 13(4): 229, 2011 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-21787439

RESUMO

MicroRNAs (miRNAs) are endogenous, non-coding, single-stranded RNAs about 21 nucleotides in length. miRNAs have been shown to regulate gene expression and thus influence a wide range of physiological and pathological processes. Moreover, they are detected in a variety of sources, including tissues, serum, and other body fluids, such as saliva. The role of miRNAs is evident in various malignant and nonmalignant diseases, and there is accumulating evidence also for an important role of miRNAs in systemic rheumatic diseases. Abnormal expression of miRNAs has been reported in autoimmune diseases, mainly in systemic lupus erythematosus and rheumatoid arthritis. miRNAs can be aberrantly expressed even in the different stages of disease progression, allowing miRNAs to be important biomarkers, to help understand the pathogenesis of the disease, and to monitor disease activity and effects of treatment. Different groups have demonstrated a link between miRNA expression and disease activity, as in the case of renal flares in lupus patients. Moreover, miRNAs are emerging as potential targets for new therapeutic strategies of autoimmune disorders. Taken together, recent data demonstrate that miRNAs can influence mechanisms involved in the pathogenesis, relapse, and specific organ involvement of autoimmune diseases. The ultimate goal is the identification of a miRNA target or targets that could be manipulated through specific therapies, aiming at activation or inhibition of specific miRNAs responsible for the development of disease.


Assuntos
MicroRNAs , Doenças Reumáticas/genética , Humanos , Doenças Reumáticas/imunologia
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