Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 85
Filter
Add more filters

Publication year range
1.
Hepatology ; 78(4): 1092-1105, 2023 10 01.
Article in English | MEDLINE | ID: mdl-37055018

ABSTRACT

BACKGROUND AND AIMS: Chronic liver disease is a growing epidemic, leading to fibrosis and cirrhosis. TGF-ß is the pivotal profibrogenic cytokine that activates HSC, yet other molecules can modulate TGF-ß signaling during liver fibrosis. Expression of the axon guidance molecules semaphorins (SEMAs), which signal through plexins and neuropilins (NRPs), have been associated with liver fibrosis in HBV-induced chronic hepatitis. This study aims at determining their function in the regulation of HSCs. APPROACH AND RESULTS: We analyzed publicly available patient databases and liver biopsies. We used transgenic mice, in which genes are deleted only in activated HSCs to perform ex vivo analysis and animal models. SEMA3C is the most enriched member of the semaphorin family in liver samples from patients with cirrhosis. Higher expression of SEMA3C in patients with NASH, alcoholic hepatitis, or HBV-induced hepatitis discriminates those with a more profibrotic transcriptomic profile. SEMA3C expression is also elevated in different mouse models of liver fibrosis and in isolated HSCs on activation. In keeping with this, deletion of SEMA3C in activated HSCs reduces myofibroblast marker expression. Conversely, SEMA3C overexpression exacerbates TGF-ß-mediated myofibroblast activation, as shown by increased SMAD2 phosphorylation and target gene expression. Among SEMA3C receptors, only NRP2 expression is maintained on activation of isolated HSCs. Interestingly, lack of NRP2 in those cells reduces myofibroblast marker expression. Finally, deletion of either SEMA3C or NRP2, specifically in activated HSCs, reduces liver fibrosis in mice. CONCLUSION: SEMA3C is a novel marker for activated HSCs that plays a fundamental role in the acquisition of the myofibroblastic phenotype and liver fibrosis.


Subject(s)
Hepatic Stellate Cells , Semaphorins , Animals , Humans , Mice , Hepatic Stellate Cells/metabolism , Liver/pathology , Liver Cirrhosis/pathology , Phosphorylation , Semaphorins/genetics , Semaphorins/metabolism , Transforming Growth Factor beta/metabolism
2.
Appl Opt ; 63(4): 1015-1021, 2024 Feb 01.
Article in English | MEDLINE | ID: mdl-38437399

ABSTRACT

We demonstrate a mode-locked erbium-doped fiber laser (EDFL) utilizing copper phthalocyanines (CuPc) as a saturable absorber (SA) for the first time, to the best of our knowledge. The investigated SA was prepared using a simple, low-cost and straightforward technique, whereby the CuPc powder was embedded into polyvinyl alcohol (PVA) to form a thin film. The thin film acted as a mode-locker when it was incorporated into the EDFL cavity to produce output pulses at a repetition rate of 1.8 MHz with a pulse duration of 1.98 ps. The frequency spectrum showed a signal-to-noise ratio as high as 55 dB, which indicates the stability of the mode-locking operation. To the best of our knowledge, this is the first work to report using CuPc as a mode-locker.

3.
Int J Mol Sci ; 24(9)2023 Apr 30.
Article in English | MEDLINE | ID: mdl-37175808

ABSTRACT

Sepsis affects millions of people worldwide and is associated with multiorgan dysfunction that is a major cause of increased morbidity and mortality. Sepsis is associated with several morbidities, such as lung, liver, and central nervous system (CNS) dysfunction. Sepsis-associated CNS dysfunction usually leads to several mental problems including depression. IL-17A is one of the crucial cytokines that is expressed and secreted by Th17 cells. Th17 cells are reported to be involved in the pathogenesis of depression and anxiety in humans and animals. One of the protein tyrosine kinases that plays a key role in controlling the development/differentiation of Th17 cells is ITK. However, the role of ITK in sepsis-associated neuroinflammation and depression-like symptoms in mice has not been investigated earlier. Therefore, this study investigated the efficacy of the ITK inhibitor, BMS 509744, in sepsis-linked neuroinflammation (ITK, IL-17A, NFkB, iNOS, MPO, lipid peroxides, IL-6, MCP-1, IL-17A) and a battery of depression-like behavioral tests, such as sucrose preference, tail suspension, and the marble burying test. Further, the effect of the ITK inhibitor on anti-inflammatory signaling (Foxp3, IL-10, Nrf2, HO-1, SOD-2) was assessed in the CNS. Our data show that sepsis causes increased ITK protein expression, IL-17A signaling, and neuroinflammatory mediators in the CNS that are associated with a depression-like state in mice. ITK inhibitor-treated mice with sepsis show attenuated IL-17A signaling, which is associated with the upregulation of IL-10/Nrf2 signaling and the amelioration of depression-like symptoms in mice. Our data show, for the first time, that the ITK inhibition strategy may counteract sepsis-mediated depression through a reduction in IL-17A signaling in the CNS.


Subject(s)
Interleukin-10 , Sepsis , Animals , Mice , Depression/drug therapy , Depression/etiology , Interleukin-17/metabolism , Neuroinflammatory Diseases , NF-E2-Related Factor 2 , Sepsis/complications
4.
Am J Physiol Lung Cell Mol Physiol ; 323(1): L14-L26, 2022 07 01.
Article in English | MEDLINE | ID: mdl-35608267

ABSTRACT

Critically ill patients manifest many of the same immune features seen in coronavirus disease 2019 (COVID-19), including both "cytokine storm" and "immune suppression." However, direct comparisons of molecular and cellular profiles between contemporaneously enrolled critically ill patients with and without severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) are limited. We sought to identify immune signatures specifically enriched in critically ill patients with COVID-19 compared with patients without COVID-19. We enrolled a multisite prospective cohort of patients admitted under suspicion for COVID-19, who were then determined to be SARS-CoV-2-positive (n = 204) or -negative (n = 122). SARS-CoV-2-positive patients had higher plasma levels of CXCL10, sPD-L1, IFN-γ, CCL26, C-reactive protein (CRP), and TNF-α relative to SARS-CoV-2-negative patients adjusting for demographics and severity of illness (Bonferroni P value < 0.05). In contrast, the levels of IL-6, IL-8, IL-10, and IL-17A were not significantly different between the two groups. In SARS-CoV-2-positive patients, higher plasma levels of sPD-L1 and TNF-α were associated with fewer ventilator-free days (VFDs) and higher mortality rates (Bonferroni P value < 0.05). Lymphocyte chemoattractants such as CCL17 were associated with more severe respiratory failure in SARS-CoV-2-positive patients, but less severe respiratory failure in SARS-CoV-2-negative patients (P value for interaction < 0.01). Circulating T cells and monocytes from SARS-CoV-2-positive subjects were hyporesponsive to in vitro stimulation compared with SARS-CoV-2-negative subjects. Critically ill SARS-CoV-2-positive patients exhibit an immune signature of high interferon-induced lymphocyte chemoattractants (e.g., CXCL10 and CCL17) and immune cell hyporesponsiveness when directly compared with SARS-CoV-2-negative patients. This suggests a specific role for T-cell migration coupled with an immune-checkpoint regulatory response in COVID-19-related critical illness.


Subject(s)
COVID-19 , Respiratory Insufficiency , B7-H1 Antigen , Chemokines , Critical Illness , Humans , Prospective Studies , SARS-CoV-2 , Tumor Necrosis Factor-alpha
5.
J Infect Dis ; 224(12 Suppl 2): S228-S236, 2021 09 01.
Article in English | MEDLINE | ID: mdl-34469563

ABSTRACT

BACKGROUND: In 2013, the Dominican Republic introduced 13-valent pneumococcal conjugate vaccine (PCV13) using a 3-dose schedule (at 2, 4 and 12 months of age). We evaluated the impact of PCV13 on serotypes causing pneumococcal pneumonia with pleural effusion. METHODS: Surveillance data after PCV13 introduction (July 2014 to June 2016) were compared with data before PCV13 introduction (July 2009 to June 2011). Cases were defined as radiologic evidence of pneumonia with pleural effusion in a child aged <15 years. Pneumococcus was detected in pleural fluid by either culture or polymerase chain reaction, and serotyping was performed. The Ministry of Health's PCV13 uptake data for 2014-2016 were obtained. RESULTS: The prevalence of pneumococcus among cases was similar before and after PCV13 introduction (56.4% and 52.8%, respectively). The proportion of pneumococcal cases caused by vaccine serotypes was 86% for children <2 years old both before and PCV13 introduction. Compared with before PCV13, serotype 14 accounted for a smaller (28% vs 13%, respectively; P = .02) and serotype 1 for a larger (23% vs 37%; P = .09) proportion of pneumococcal cases after PCV13 introduction. National uptake for the first, second, and third PCV13 doses was 94%, 81%, and 28%, respectively, in 2014 and 75%, 61%, and 26% in 2015. DISCUSSION: While the decrease in pneumococcal pneumonia with pleural effusion caused by serotype 14 may reflect an early effect of PCV13 implementation, other vaccine serotypes, including serotype 1, are not well controlled. Better PCV13 coverage for all 3 doses is needed.


Subject(s)
Pneumococcal Infections/epidemiology , Pneumococcal Vaccines/administration & dosage , Pneumococcal Vaccines/adverse effects , Pneumonia, Pneumococcal/epidemiology , Vaccines, Conjugate/adverse effects , Child , Child, Preschool , Dominican Republic/epidemiology , Female , Humans , Infant , Male , Pleural Effusion/epidemiology , Pleural Effusion/etiology , Pneumococcal Infections/complications , Pneumococcal Infections/prevention & control , Pneumococcal Vaccines/immunology , Pneumonia, Pneumococcal/complications , Pneumonia, Pneumococcal/prevention & control , Postoperative Complications , Prevalence , Serogroup , Streptococcus pneumoniae/immunology , Streptococcus pneumoniae/isolation & purification , Vaccination , Vaccines, Conjugate/administration & dosage , Vaccines, Conjugate/immunology
6.
Crit Care ; 25(1): 148, 2021 04 19.
Article in English | MEDLINE | ID: mdl-33874973

ABSTRACT

BACKGROUND: Analyses of blood biomarkers involved in the host response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) viral infection can reveal distinct biological pathways and inform development and testing of therapeutics for COVID-19. Our objective was to evaluate host endothelial, epithelial and inflammatory biomarkers in COVID-19. METHODS: We prospectively enrolled 171 ICU patients, including 78 (46%) patients positive and 93 (54%) negative for SARS-CoV-2 infection from April to September, 2020. We compared 22 plasma biomarkers in blood collected within 24 h and 3 days after ICU admission. RESULTS: In critically ill COVID-19 and non-COVID-19 patients, the most common ICU admission diagnoses were respiratory failure or pneumonia, followed by sepsis and other diagnoses. Similar proportions of patients in both groups received invasive mechanical ventilation at the time of study enrollment. COVID-19 and non-COVID-19 patients had similar rates of acute respiratory distress syndrome, severe acute kidney injury, and in-hospital mortality. While concentrations of interleukin 6 and 8 were not different between groups, markers of epithelial cell injury (soluble receptor for advanced glycation end products, sRAGE) and acute phase proteins (serum amyloid A, SAA) were significantly higher in COVID-19 compared to non-COVID-19, adjusting for demographics and APACHE III scores. In contrast, angiopoietin 2:1 (Ang-2:1 ratio) and soluble tumor necrosis factor receptor 1 (sTNFR-1), markers of endothelial dysfunction and inflammation, were significantly lower in COVID-19 (p < 0.002). Ang-2:1 ratio and SAA were associated with mortality only in non-COVID-19 patients. CONCLUSIONS: These studies demonstrate that, unlike other well-studied causes of critical illness, endothelial dysfunction may not be characteristic of severe COVID-19 early after ICU admission. Pathways resulting in elaboration of acute phase proteins and inducing epithelial cell injury may be promising targets for therapeutics in COVID-19.


Subject(s)
COVID-19/blood , Endothelial Cells/virology , Epithelial Cells/virology , Host Microbial Interactions , Inflammation/virology , Adult , Aged , Biomarkers/blood , COVID-19/epidemiology , COVID-19/therapy , Case-Control Studies , Female , Humans , Inflammation/blood , Intensive Care Units , Male , Middle Aged , Prospective Studies
7.
Clin Infect Dis ; 70(12): 2484-2492, 2020 06 10.
Article in English | MEDLINE | ID: mdl-31402387

ABSTRACT

BACKGROUND: The 13-valent pneumococcal vaccine (PCV13) was introduced for US children in 2010 and for immunocompromised adults ≥19 years old in series with the 23-valent polysaccharide vaccine (PPSV23) in 2012. We evaluated PCV13 indirect effects on invasive pneumococcal disease (IPD) among adults with and without PCV13 indications. METHODS: Using Active Bacterial Core surveillance and the National Health Survey, using Active Bacterial Core surveillance and the National Health Interview Survey, we estimated and compared IPD incidence in 2013-2014 and 2007-2008, by age and serotype group (PCV13, PPSV23-unique, or nonvaccine types [NVTs]), among adults with and without PCV13 indications. RESULTS: IPD incidence declined among all adults. Among adults 19-64 years, PCV13-type IPD declined 57% (95% confidence interval [CI], -68% to -43%) in adults with immunocompromising conditions (indication for PCV13 use), 57% (95% CI, -62% to -52%) in immunocompetent adults with chronic medical conditions (CMCs, indications for PPSV23 use alone), and 74% (95% CI, -78% to -70%) in adults with neither vaccine indication. Among adults aged ≥65 years, PCV13-type IPD decreased 68% (95% CI, -76% to -60%) in those with immunocompromising conditions, 68% (95% CI, -72% to -63%) in those with CMCs, and 71% (95% CI, -77% to -64%) in healthy adults. PPSV23-unique types increased in adults 19‒64 years with CMCs, and NVTs did not change among adults with or without PCV13 indications. From 2013 to 2014, non-PCV13 serotypes accounted for 80% of IPD. CONCLUSIONS: IPD incidence among US adults declined after PCV13 introduction in children. Similar reductions in PCV13-type IPD in those with and without PCV13 indications suggest that observed benefits are largely due to indirect effects from pediatric PCV13 use rather than direct use among adults.


Subject(s)
Pneumococcal Infections , Streptococcus pneumoniae , Adult , Child , Humans , Incidence , Pneumococcal Infections/epidemiology , Pneumococcal Infections/prevention & control , Pneumococcal Vaccines , Serogroup , United States/epidemiology , Vaccines, Conjugate
8.
Trop Anim Health Prod ; 52(1): 301-308, 2020 Jan.
Article in English | MEDLINE | ID: mdl-31338729

ABSTRACT

The aim was to explore the impact of periconceptional folic acid or flaxseed oil (FXO) supplementation on fertility, progesterone profile, and blood chemistry in pregnant ewes during the breeding season. In total, 54 Ossimi ewes were divided into three groups (18 animals each). The control treatment (CON) fed a basal diet only, while the others fed the basal diet and supplemented every other day with a single bolus of folic acid (FO 500 µg/head) or flaxseed oil (FX 50 ml/head). During the early stage of pregnancy, the FO and FX groups showed significantly higher serum antioxidant activity (glutathione and superoxide dismutase) as compared with the control CON group (P = 0.012 and 0.007, respectively). Although no significant variations were detected in the serum nitric oxide levels during the early stage and mid-stage of pregnancy, the FO and FX groups showed significantly lower serum nitric oxide concentration in the late stage of pregnancy (P = 0.001). The FO and FX groups showed significantly higher serum progesterone concentrations during the early stage (10.9 and 11.4 ng/ml, respectively) and mid-stage (22.2 and 23.4 ng/ml, respectively) of pregnancy as compared with the CON group (7.72 and 13.9 ng/ml, respectively). The FX group exhibited a significantly higher lambing rate (P = 0.034), as well as the proportion of female lambs (P = 0.029) as compared with the CON group. In conclusion, supplementing Ossimi ewes with folic acid or FXO significantly improved the progesterone profile during pregnancy. Moreover, the FXO supplementation significantly increased the lambing rate and the female lamb rate as compared with the control group.


Subject(s)
Dietary Supplements , Folic Acid , Linseed Oil , Pregnancy, Animal , Sheep, Domestic , Animals , Body Weight , Diet/veterinary , Female , Fertility , Pregnancy , Progesterone/blood , Sheep
9.
J Biol Regul Homeost Agents ; 32(2): 269-274, 2018.
Article in English | MEDLINE | ID: mdl-29685005

ABSTRACT

Toxigenic potential of different candidate fungi, isolated from rice straw feed of Degnala disease affected bovines was analyzed along with species, age, gender and seasonal prevalence. Of 1,536 cases, 104 (6.77%) showed positive signs with a significant association (p less than 0.05) between this disease and rice straw feeding, in buffaloes, and bovine aged over 1 year in the winter season. Complete blood count showed a marked increase in erythrocyte sedimentation rate and all white blood cells numbers, except lymphocytes in positive cases. There was a significant increase (p less than 0.05) in alanine amino transferase, aspirate amino transferase and alkaline phosphatase in the liver function test. At the same time, an increased value of creatinine was noted in the renal function test. For isolation and screening of toxigenic fungi, rice straw samples (n=40) being fed to the positive cases were processed further, and 85 fungal isolates were found, mainly of Aspergillus (57), Penicillium (10), Fusarium (04), Zygomycetes (03), Curvularia (01) and unidentified (10). All isolated fungi were subjected for mycotoxin production and only 11 showed mycotoxin-producing capability (including Aspergillus, Penicillium and Fusarium isolates) analyzed by thin layer chromatography and quantified through high performance liquid chromatography. It is concluded that all the fungi contaminating rice straw feed of Degnala affected animals were not toxigenic. This work will help in establishing major mycotoxin-producing fungi leading to the probable cause of Degnala disease in bovine.


Subject(s)
Animal Feed/microbiology , Cattle Diseases/epidemiology , Mycotoxicosis/veterinary , Oryza/microbiology , Animals , Buffaloes , Cattle , Cattle Diseases/microbiology , Food Contamination/analysis , Mycotoxicosis/epidemiology , Prevalence
10.
Trop Anim Health Prod ; 50(4): 845-850, 2018 Apr.
Article in English | MEDLINE | ID: mdl-29274055

ABSTRACT

Milk yield (MY), composition, and fatty acid profiles of purebred Holstein (HO) cows, Brown Swiss (BS), and their F1 crossbreds (HS) were compared under subtropical climate in Egypt. Pure HO had significantly greater 305-MY, total-MY, and daily-MY (p < 0.05) than pure BS and crossbred HS. Furthermore, HO and HS had significantly higher peak-MY (44.2 and 43.3 kg, respectively) than BS (36.1 kg). In comparison with HO, BS had significantly higher milk fat, protein, total solids, and solid-not-fat % (p < 0.05); however, no significant differences were observed between BS and HS for milk fat %. The milk fat of BS had higher concentrations of saturated (C17:0 and C18:0) fatty acids (FA) than that of the HO and HS (p = 0.001 and 0.008, respectively). Content of C4:0, C6:0, C8:0, C12:0, and C15.0 FA did not differ between genotypes. Milk from HO and BS had significantly higher concentrations of unsaturated (C20:1 and C20:5) FA than that from HS (p < 0.05). C14:1 (myristoleic), C16:1 (palmitoleic), and C18:2 (linoleic) FA contents were similar for all genotypes. In conclusion, BS surpassed HO for all milk composition traits and some FA components; however, HS had comparable milk fat percentage with BS. There appears to be an opportunity to modify the concentration of certain FA by breeding.


Subject(s)
Dairying , Fatty Acids/analysis , Hybridization, Genetic , Lactation/genetics , Milk/chemistry , Animals , Breeding , Cattle , Egypt , Female , Phenotype
11.
Clin Gastroenterol Hepatol ; 14(3): 421-428.e2, 2016 Mar.
Article in English | MEDLINE | ID: mdl-26499928

ABSTRACT

BACKGROUND & AIMS: Quality measures are used to standardize health care and monitor quality of care. In 2011, the American Gastroenterological Association established quality measures for inflammatory bowel disease (IBD), but there has been limited documentation of compliance from different practice settings. METHODS: We reviewed charts from 367 consecutive patients with IBD seen at academic practices, 217 patients seen at community practices, and 199 patients seen at private practices for compliance with 8 outpatient measures. Records were assessed for IBD history, medications, comorbidities, and hospitalizations. We also determined the number of patient visits to gastroenterologists in the past year, whether patients had a primary care physician at the same institution, and whether they were seen by a specialist in IBD or in conjunction with a trainee, and reviewed physician demographics. A univariate and multivariate statistical analysis was performed to determine which factors were associated with compliance of all core measures. RESULTS: Screening for tobacco abuse was the most frequently assessed core measure (89.6% of patients; n = 701 of 783), followed by location of IBD (80.3%; n = 629 of 783), and assessment for corticosteroid-sparing therapy (70.8%; n = 275 of 388). The least-frequently evaluated measures were pneumococcal immunization (16.7% of patients; n = 131 of 783), bone loss (25%; n = 126 of 505), and influenza immunization (28.7%; n = 225 of 783). Only 5.8% of patients (46 of 783) had all applicable core measures documented (24 in academic practice, none in clinical practice, and 22 in private practice). In the multivariate model, year of graduation from fellowship (odds ratio [OR], 2.184; 95% confidence interval [CI], 1.522-3.134; P < .001), year of graduation from medical school (OR, 0.500; 95% CI, 0.352-0.709; P < .001), and total number of comorbidities (OR, 1.089; 95% CI, 1.016-1.168; P = .016) were associated with compliance with all core measures. CONCLUSIONS: We found poor documentation of IBD quality measures in academic, clinical, and private gastroenterology practices. Interventions are necessary to improve reporting of quality measures.


Subject(s)
Ambulatory Care/methods , Guideline Adherence , Inflammatory Bowel Diseases/diagnosis , Inflammatory Bowel Diseases/drug therapy , Medical Records , Academic Medical Centers , Adolescent , Adult , Aged , Aged, 80 and over , Health Services Research , Humans , Inflammatory Bowel Diseases/pathology , Male , Middle Aged , Private Practice , Public Health Practice , Young Adult
12.
Cancer Cell Int ; 16: 11, 2016.
Article in English | MEDLINE | ID: mdl-26889092

ABSTRACT

BACKGROUND: Previous reports showed that the Steroidal Glycoalkaloid Solamargine inhibited proliferation of non-melanoma skin cancer cells. However, Solamargine was not tested systematically on different types of melanoma cells and was not simultaneously tested on normal cells either. In this study we aimed to investigate the effect of Solamargine and the mechanism involved in inhibiting the growth of different types of melanoma cells. METHODS: Solamargine effect was tested on normal cells and on another three melanoma cell lines. Vertical growth phase metastatic and primary melanoma cell lines WM239 and WM115, respectively and the radial growth phase benign melanoma cells WM35 were used. The half inhibitory concentration IC50 of Solamargine was determined using Alamarblue assay. The cellular and subcellular changes were assessed using light and Transmission Electron Microscope, respectively. The percentage of cells undergoing apoptosis and necrosis were measured using Flow cytometry. The different protein expression was detected and measured using western blotting. The efficacy of Solamargine was determined by performing the clonogenic assay. The data collected was analyzed statistically on the means of the triplicate of at least three independent repeated experiments using one-way ANOVA test for parametric data and Kruskal-Wallis for non-parametric data. Differences were considered significant when the P values were less than 0.05. RESULTS: Hereby, we demonstrate that Solamargine rapidly, selectively and effectively inhibited the growth of metastatic and primary melanoma cells WM239 and WM115 respectively, with minimum effect on normal and benign WM35 cells. Solamargine caused cellular necrosis to the two malignant melanoma cell lines (WM115, WM239), by rapid induction of lysosomal membrane permeabilization as confirmed by cathepsin B upregulation which triggered the extrinsic mitochondrial death pathway represented by the release of cytochrome c and upregulation of TNFR1. Solamargine disrupted the intrinsic apoptosis pathway as revealed by the down regulation of hILP/XIAP, resulting in caspase-3 cleavage, upregulation of Bcl-xL, and Bcl2, and down regulation of Apaf-1 and Bax in WM115 and WM239 cells only. Solamargine showed high efficacy in vitro particularly against the vertical growth phase melanoma cells. CONCLUSION: Our findings suggest that Solamargine is a promising anti-malignant melanoma drug which warrants further attention.

13.
Infect Immun ; 83(7): 2966-75, 2015 Jul.
Article in English | MEDLINE | ID: mdl-25964472

ABSTRACT

Staphylococcus aureus is a leading cause of prosthetic joint infections, which, as we recently showed, proceed with the involvement of biofilm-like clusters that cause recalcitrance to antibiotic treatment. Here we analyzed why these clusters grow extraordinarily large, reaching macroscopically visible extensions (>1 mm). We found that while specific S. aureus surface proteins are a prerequisite for agglomeration in synovial fluid, low activity of the Agr regulatory system and subsequent low production of the phenol-soluble modulin (PSM) surfactant peptides cause agglomerates to grow to exceptional dimensions. Our results indicate that PSMs function by disrupting interactions of biofilm matrix molecules, such as the polysaccharide intercellular adhesin (PIA), with the bacterial cell surface. Together, our findings support a two-step model of staphylococcal prosthetic joint infection: As we previously reported, interaction of S. aureus surface proteins with host matrix proteins such as fibrin initiates agglomeration; our present results show that, thereafter, the bacterial agglomerates grow to extremely large sizes owing to the lack of PSM expression under the specific conditions present in joints. Our findings provide a mechanistic explanation for the reported extreme resistance of joint infection to antibiotic treatment, lend support to the notions that Agr functionality and PSM production play a major role in defining different forms of S. aureus infection, and have important implications for antistaphylococcal therapeutic strategies.


Subject(s)
Bacterial Toxins/metabolism , Biofilms/growth & development , Staphylococcus aureus/physiology , Synovial Fluid/microbiology , Humans , Prosthesis-Related Infections/microbiology , Staphylococcal Infections/microbiology , Staphylococcus aureus/metabolism , Surface-Active Agents/metabolism
14.
Antimicrob Agents Chemother ; 59(4): 2122-8, 2015 Apr.
Article in English | MEDLINE | ID: mdl-25624333

ABSTRACT

Antibiotic prophylaxis is standard for patients undergoing surgical procedures, yet despite the wide use of antibiotics, breakthrough infections still occur. In the setting of total joint arthroplasty, such infections can be devastating. Recent findings have shown that synovial fluid causes marked staphylococcal aggregation, which can confer antibiotic insensitivity. We therefore asked in this study whether clinical samples of synovial fluid that contain preoperative prophylactic antibiotics can successfully eradicate a bacterial challenge by pertinent bacterial species. This study demonstrates that preoperative prophylaxis with cefazolin results in high antibiotic levels. Furthermore, we show that even with antibiotic concentrations that far exceed the expected bactericidal levels, Staphylococcus aureus bacteria added to the synovial fluid samples are not eradicated and are able to colonize model implant surfaces, i.e., titanium pins. Based on these studies, we suggest that current prophylactic antibiotic choices, despite high penetration into the synovial fluid, may need to be reexamined.


Subject(s)
Anti-Bacterial Agents/pharmacology , Antibiotic Prophylaxis , Biofilms/drug effects , Cefazolin/pharmacology , Staphylococcus aureus/drug effects , Synovial Fluid/microbiology , Alloys , Bacterial Adhesion , Bone Nails/microbiology , Drug Resistance, Bacterial , Humans , Microbial Sensitivity Tests , Titanium
15.
Biomacromolecules ; 16(2): 650-9, 2015 Feb 09.
Article in English | MEDLINE | ID: mdl-25585173

ABSTRACT

A stimuli-responsive, controlled release bilayer for the prevention of bacterial infection on biomaterials is presented. Drug release is locally controlled by the pH-responsiveness of the bilayer, comprised of an inner poly(acrylic acid) (PAA) monolayer grafted to a biomaterial and cross-linked with an outer chitosan (CH) brush. Tobramycin (TOB) is loaded in the inner PAA in part to minimize bacteria resistance. Because biofilm formation causes a decrease in local pH, TOB is released from PAA and permeates through the CH, which is in contact with the biofilm. Antibiotic capacity is controlled by the PAA thickness, which depends on PAA brush length and the extent of cross-linking between CH and PAA at the bilayer interface. This TOB-loaded, pH-responsive bilayer exhibits significantly enhanced antibacterial activity relative to controls.


Subject(s)
Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/metabolism , Drug Delivery Systems/methods , Staphylococcus aureus/metabolism , Tobramycin/chemistry , Tobramycin/metabolism , Anti-Bacterial Agents/administration & dosage , Hydrogen-Ion Concentration , Staphylococcus aureus/drug effects , Tobramycin/administration & dosage
16.
Clin Orthop Relat Res ; 473(9): 2865-73, 2015 Sep.
Article in English | MEDLINE | ID: mdl-25894811

ABSTRACT

BACKGROUND: Allograft bone is commonly used to augment bone stock. Unfortunately, allograft is prone to bacterial contamination and current antimicrobial therapies are inadequate. Photoactivated porphyrins combat bacterial growth by production of reactive oxygen species (ROS); however, to our knowledge, they have not been tested in the setting of allograft bone. QUESTIONS/PURPOSES: We asked: (1) Does 5,10,15,20-tetrakis-(4-aminophenyl)-porphyrin (TAPP) stably adsorb to morselized, mineralized allograft? (2) Does Staphylococcus aureus acquire TAPP from TAPP-allograft? (3) Is TAPP-allograft antibacterial to S. aureus? (4) Is ROS production critical for antimicrobial activity? (5) Does illuminated TAPP-allograft dislodge biofilm? (6) Could other photoactive dyes (TAPP, TMPyP, TSP, THP, and methylene blue) confer antimicrobial properties to allograft? METHODS: TAPP adsorption to allograft (TAPP-allograft), its localization in S. aureus, and TAPP-allograft long-term stability were determined spectrophotometrically. Antimicrobial activity was measured while activated with light or in the dark during incubation with S. aureus or after allograft biofilm formation. Glutathione was added to illuminated TAPP-allograft to quench ROS and antimicrobial activity was determined. Light-dependent antimicrobial activity of other photoactive dyes (TMPyP, TSP, THP, and methylene blue) adsorbed to allograft was also tested. RESULTS: We found (1) porphyrins strongly adhere to bone allograft; and (2) the bacteria are not able to sequester TAPP from the TAPP-allograft; (3) when illuminated, TAPP-allograft is resistant to bacterial adherence; (4) the effects of TAPP are inhibited by the radical scavenger glutathione, indicating ROS-dependent antimicrobial activity; (5) illumination of TAPP-allograft disrupts biofilms; and, (6) other photoactive dyes impede biofilm formation on allograft bone in the presence of light. CONCLUSIONS: Porphyrins stably associate with allograft and are inactive until illuminated. Illuminated TAPP-allograft markedly reduces bacterial colonization, which is restored in the presence of radical scavengers. Finally, illuminated TAPP-allograft disrupts biofilms. CLINICAL RELEVANCE: The findings of this in vitro study suggest that loading bone allograft with biocompatible porphyrins before surgery might allow increased sterility of the allograft during implantation. Future testing in an animal model will determine if these in vitro activities can be used to prevent allograft-based infection in an establishing osteomyelitis.


Subject(s)
Allografts/drug effects , Anti-Bacterial Agents/pharmacology , Biofilms/drug effects , Bone Transplantation/methods , Coated Materials, Biocompatible , Porphyrins/pharmacology , Staphylococcal Infections/prevention & control , Staphylococcus aureus/drug effects , Adsorption , Allografts/microbiology , Allografts/radiation effects , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/radiation effects , Biofilms/growth & development , Bone Transplantation/adverse effects , Drug Stability , Equipment Design , Humans , Photochemical Processes , Porphyrins/chemistry , Porphyrins/radiation effects , Reactive Oxygen Species/metabolism , Staphylococcal Infections/microbiology , Staphylococcus aureus/growth & development , Time Factors
17.
Clin Gastroenterol Hepatol ; 12(5): 749-55, 2014 May.
Article in English | MEDLINE | ID: mdl-24632348

ABSTRACT

Cells can innately recognize generic products of viruses, bacteria, fungi, or injured tissue by engagement of pattern recognition receptors. Innate immune cells rapidly respond to this engagement to control commensals, thwart pathogens, and/or prompt repair. Insufficient or excessive activation of the innate immune response results in disease. This review focuses on pattern recognition receptors and cells of the innate immune system that are important for intestinal function. Our improving knowledge pertaining to this important aspect of our immune response is opening potential important new therapeutic opportunities for the treatment of disease.


Subject(s)
Gastrointestinal Diseases/immunology , Gastrointestinal Diseases/pathology , Immunity, Innate , Cytokines/metabolism , Humans , Leukocytes/immunology , Receptors, Pattern Recognition/metabolism
18.
Cureus ; 16(1): e52666, 2024 Jan.
Article in English | MEDLINE | ID: mdl-38249656

ABSTRACT

Angina bullosa hemorrhagica (ABH) is a rare, benign condition that is characterized by a blood-filled blister in the oropharynx. This report describes the case of a 27-year-old male who developed a blister in the oral cavity that ruptured abruptly and resolved spontaneously. The diagnosis of ABH was made according to the diagnostic criteria of Ordioni et al. The core motive of this report is to demonstrate the clinical features and course of ABH to avoid misdiagnosis.

19.
J Taibah Univ Med Sci ; 19(3): 500-515, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38571699

ABSTRACT

Background: Oral health is linked to physical and mental well-being. Oral disease is common among poor and socioeconomically disadvantaged people in developing and industrialized countries. Objectives: This study assessed the oral health disease burden among people with multimorbidity in marginalized populations. Methods: This cross-sectional study was conducted across 16 locations in the slums of Karachi, Pakistan, to assess oral health disease problems among adults aged 18 to 70 with comorbidity or multimorbidity. The questionnaire covered the socioethnic, demographic, and disease status of people with oral health status. Data analyses were performed using SAS version 9.4. Results: Of the 16 designated slum locations, 870 individuals were considered for oral health screening. Gingivitis was highly prevalent, 29% among slum dwellers with multimorbidity of diabetes, hepatitis, and hypertension. Dandasa was widely used as a tooth-cleansing agent in 35% of the study population. By contrast, 45.4% of people showed unsatisfactory oral hygiene conditions. Pathan ethnicity showed the highest prevalence (i.e., 29.8% of dental problems with disease multimorbidity in 26.8% of Baldia Town residents of Karachi). Of the 870 individuals, the highest frequency of dental problems was found in the age group of 18-38 years (28-42.9%) and among female participants (53.8%). Conclusion: There is an urgent need for the global enhancement of public health programs, specifically focusing on implementing effective strategies to prevent oral illnesses, promote oral health, and address other chronic diseases in basic healthcare settings. Enhancing oral health poses significant difficulties, especially in less developed nations.

20.
Adv Radiat Oncol ; 9(5): 101456, 2024 May.
Article in English | MEDLINE | ID: mdl-38550376

ABSTRACT

Purpose: The purpose of this study was to evaluate the feasibility and safety of dose-escalated proton beam therapy for treating chordomas and chondrosarcomas of the skull base and spine. Methods: A prospective cohort of 54 patients (42 with chordomas and 12 with chondrosarcomas) was enrolled between 2010 and 2018. The primary endpoints were feasibility and <20% rate of acute grade ≥3 toxicity, and secondary endpoints included cancer-specific outcomes and toxicities. Patients were followed with magnetic resonance imaging or computed tomography at 3-month intervals. Proton beam therapy was delivered with doses up to 79.2 Gy using protons only, combination protons/intensity modulated radiation therapy (IMRT), or IMRT only. Results: Feasibility endpoints were met, with only 2 out of 54 patient radiation therapy plans failing to meet dosimetric constraints with protons, and 4 out of 54 experiencing a delay or treatment break >5 days, none for toxicities related to treatment. There were no grade 4 acute toxicities and 1 grade 3 acute toxicity (sensory neuropathy). The only 2 grade 3 late toxicities recorded, osteoradionecrosis and intranasal carotid blowout (mild and not emergently treated), occurred in a single patient. We report overall survival as 83% at 5 years, with local failure-free survival and progression-free survival rates of 72% and 68%, respectively. Five patients developed distant disease, and among the 9/54 patients who died, 4 deaths were not attributed to treatment or recurrence. Conclusions: Our findings suggest that high-dose proton therapy alone or in combination with IMRT is a safe and effective treatment option for chordomas and chondrosarcomas of the skull base and spine.

SELECTION OF CITATIONS
SEARCH DETAIL