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1.
Treatment of posterior eye diseases is more challenging than the anterior segment ailments due to a series of anatomical barriers and physiological constraints confronted by drug delivery to the back of the eye. In recent years, concerted efforts in drug delivery have been made to prolong the residence time of drugs injected in the vitreous humor of the eye. Our previous studies demonstrated that poly(ortho ester) (POE) nanoparticles were biodegradable/biocompatible and were capable of long-term sustained release. The objective of the present study was to investigate the safety and localization of POE nanoparticles in New Zealand white rabbits and C57BL/6 mice after intravitreal administration for the treatment of chronic posterior ocular diseases. Two concentration levels of POE nanoparticles solution were chosen for intravitreal injection: 1.5?mg/ml and 10?mg/ml. Our results demonstrate that POE nanoparticles were distributed throughout the vitreous cavity by optical coherence tomography (OCT) examination 14 days post-intravitreal injection. Intraocular pressure was not changed from baseline. Inflammatory or adverse effects were undetectable by slit lamp biomicroscopy. Furthermore, we demonstrate that POE nanoparticles have negligible toxicity assessed at the cellular level evidenced by a lack of glia activation or apoptosis estimation after intravitreal injection. Collectively, POE nanoparticles are a novel and nontoxic as an ocular drug delivery system for the treatment of posterior ocular diseases. 相似文献
2.
Harshini K. Ashar Sivasami Pulavendran Jennifer M. Rudd Prasanthi Maram Mallika Achanta Vincent T.K. Chow Jerry R. Malayer Timothy A. Snider Narasaraju Teluguakula 《The American journal of pathology》2021,191(4):669-685
Excessive neutrophil influx, their released neutrophil extracellular traps (NETs), and extracellular histones are associated with disease severity in influenza-infected patients. Neutrophil chemokine receptor CXC chemokine receptor 2 (CXCR2) is a critical target for suppressing neutrophilic inflammation. Herein, temporal dynamics of neutrophil activity and NETosis were investigated to determine the optimal timing of treatment with the CXCR2 antagonist, SCH527123 (2-hydroxy-N,N-dimethyl-3-[2-([(R)-1-(5-methyl-furan-2-yl)-propyl]amino)-3,4-dioxo-cyclobut-1-enylamino]-benzamide), and its efficacy together with antiviral agent, oseltamivir, was tested in murine and piglet influenza-pneumonia models. SCH527123 plus oseltamivir markedly improved survival of mice infected with lethal influenza, and diminished lung pathology in swine-influenza–infected piglets. Mechanistically, addition of SCH527123 in the combination treatment attenuated neutrophil influx, NETosis, in both mice and piglets. Furthermore, neutrophils isolated from influenza-infected mice showed greater susceptibility to NETotic death when stimulated with a CXCR2 ligand, IL-8. In addition, CXCR2 stimulation induced nuclear translocation of neutrophil elastase, and enhanced citrullination of histones that triggers chromatin decondensation during NET formation. Studies on temporal dynamics of neutrophils and NETs during influenza thus provide important insights into the optimal timing of CXCR2 antagonist treatment for attenuating neutrophil-mediated lung pathology. These findings reveal that pharmacologic treatment with CXCR2 antagonist together with an antiviral agent could significantly ameliorate morbidity and mortality in virulent and sublethal influenza infections.Influenza virus infections during pandemic outbreaks and yearly seasonal epidemics cause significant morbidity and mortality rates globally.1 Seasonal influenza-associated deaths have increased in recent years, with an estimated of >600,000 fatalities annually.2 A significant proportion of hospitalized patients with influenza develop complications of acute respiratory distress syndrome, characterized by widespread alveolar-capillary injury, inflammation, edema, and parenchymal hemorrhage.3, 4, 5, 6, 7, 8 These pathologic manifestations are driven by virus-inflicted cytopathic effects as well as exaggerated host immune responses.9, 10, 11 Vaccination is the logical choice for controlling the virus. However, because of unrelenting emergence of new strains and their mutative ability, vaccination presents a major challenge during influenza outbreaks.12,13 In such cases, treatment primarily depends on antiviral therapy. Administration of antiviral drugs may not always be effective, as considerable lung pathology is mediated by exaggerated host-immune responses in addition to virus-inflicted cytotoxicity.14, 15, 16, 17Previously, we established that massive neutrophil influx, their induced neutrophil extracellular traps (NETs), and extracellular histones (ECHs) aggravate pulmonary pathology in severe influenza.18, 19, 20, 21, 22, 23 Aberrant neutrophil activity and accumulation of NETs are also documented in patients with severe influenza.24,25 Neutrophils are recruited to the site of injury/infection via chemokine signaling, mediated through chemokine receptors. Among various chemokine receptors, CXC chemokine receptor 2 (CXCR2) plays a critical role in modulating neutrophil functionality during influenza.26 Numerous clinical studies have also tested CXCR2 antagonists for their efficacy in reducing inflammation and organ injuries in acute and chronic diseases.27, 28, 29, 30, 31 Recently, human phase 2 trials evaluated the safety and efficacy of a CXCR2 antagonist, danirixin, alone or in combination with oseltamivir in influenza-infected patients.27,28 Although administration of danirixin was found to be safe and well-tolerated, no differences in the clinical scores were observed between patients given oseltamivir alone and those given danirixin plus oseltamivir.27 Furthermore, there was inconsistency in neutrophil numbers among different treatment groups. This inconsistency may be attributed to the absence of rational determination of the optimal timing and dosing of danirixin, to achieve the fine balance of suppressing excessive neutrophil influx, without compromising the beneficial host immunity by neutrophils. Moreover, the underlying mechanistic roles of targeting CXCR2 and its pathogenic association with influenza pneumonia have not been established.NETs are large extracellular web-like chromatin strands that were initially proposed to have a defense mechanism against invading pathogens.32 However, excessive release of NETs aggravates tissue injury and death, as reported in several disease conditions.33, 34, 35, 36 NETosis is regulated by various granule and nuclear proteins.37 Myeloperoxidase (MPO) and neutrophil elastase (NEs) are released from azurophilic granules, anchor chromatin scaffolds in NETs, and mediate histone degradation during NETosis.38 We reported earlier that blocking MPO decreases NETs, but signaling mechanisms in influenza-induced NETosis remain unclear.17,18 Herein, we evaluated the therapeutic efficacy of a CXCR2 antagonist, SCH527123 (2-hydroxy-N,N-dimethyl-3-[2-([(R)-1-(5-methyl-furan-2-yl)-propyl]amino)-3,4-dioxo-cyclobut-1-enylamino]-benzamide) alone or in combination with antiviral agent, oseltamivir (which inhibits viral neuraminidase and prevents progeny virus release from infected cells), in models of lethal influenza-infected mice and sublethal swine influenza-infected piglets. SCH527123 plus oseltamivir significantly improved survival in lethal influenza-challenged mice, and attenuated lung pathology in swine influenza-infected piglets. Thus, SCH5277123 plus oseltamivir represents a promising combination treatment against influenza pneumonia. 相似文献
3.
Ravi A Mallika A Sama V Begum AS Khan RS Reddy BM 《Journal of ethnopharmacology》2011,137(3):1353-1359
Ethnopharmacological relevance
The bark of Tecomella undulata is primarily used in the treatment of syphilis, painful swellings and cancer by traditional healers. Also, it is claimed to be useful in treating urinary discharges, enlargement of spleen, leucorrhoea, leukoderma, tumors, liver disorders, gonorrhea, gout and promotes wound healing in Indian traditional system of medicine.Aim
To establish a scientific validation for the antitumor effects of Tecomella undulata bark and explore the mechanistic pathway in chronic myeloid leukemia cell line, K562. The study was further extended to standardize the extract using quercetin as biomarker.Methods
Induction of apoptosis by chloroform extract of Tecomella undulata bark (CTUB) was determined by MTT, Annexin V and caspase activation assays. The cell cycle analysis was done by flow cytometer and nuclear staining by DAPI. The standardization of the extract was performed through reverse phase-HPLC method under PDA detection.Result
Results clearly showed the induction of apoptosis by CTUB in K562 cells. The effect was found to be dose dependent, having IC50 of 30 μg/ml with activation of FAS, FADD, caspase 8, caspase 3/7 and fragmentation of DNA. The bioactive CTUB was determined to possess 0.03% (w/w) of quercetin.Conclusion
The investigation clearly demonstrated the potential antitumor effect of CTUB, thereby validating the traditional claim. Quercetin, known to have anticancer activity is being reported and quantified for the first time from the bark of Tecomella undulata. 相似文献4.
OBJECTIVE: To investigate how term and preterm labor (PTL) influence the balance between maternal proinflammatory and antiinflammatory responses as measured by expression of major histocompatibility complex (MHC) Class II on maternal monocytes and tumor necrosis factor-alpha (TNF-alpha) production by in vitro stimulation of whole blood by lipopolysaccharide (LPS). METHODS: Blood was taken from the following women (n=118): term elective cesarean delivery or in spontaneous labor, in premature labor, or with preterm premature rupture of the membranes (PROM) at less than 32 weeks, and gestation-matched reference group. Monocyte MHC Class II expression was measured by flow cytometry using a dual-staining technique. Plasma cytokine levels were assayed using a cytometric bead array system. In vitro whole blood stimulation with LPS was also performed, and cytokine production was measured. RESULTS: Term labor was associated with a fall in the percentage of monocytes expressing MHC Class II, compared with third trimester of pregnancy, P<.05 and a reduction in LPS-stimulated TNF-alpha production. This fall in MHC Class II was even more pronounced in PTL and preterm PROM groups compared with the reference group, P<.01. CONCLUSION: There was evidence of reduced expression of monocyte MHC Class II and LPS-stimulated TNF-alpha in term and preterm labor. This pattern of reduced MHC Class II expression and reduced TNF-alpha production is known as monocyte hyporesponsiveness or immune paresis. Detection of this state may provide insights into the maternal inflammatory status and be of use in the management of women with threatened PTL or preterm PROM. LEVEL OF EVIDENCE: II. 相似文献
5.
Maria Bindu Bagh Ishita Guha Thakurta Mallika Biswas Prajna Behera Sasanka Chakrabarti 《Biogerontology》2011,12(2):119-131
A combination of antioxidants (N-acetyl cysteine, α-lipoic acid, and α-tocopherol) was selected for long term oral supplementation
study in rats for protective effects on age-related mitochondrial alterations in the brain. Four groups of rats were chosen:
young control (6–7 months); aged rats (22–24 months); aged rats (22–24 months) on daily antioxidant supplementation from 18 month
onwards and young rats (6–7 months) on daily antioxidant supplementation from 2 month onwards. The brain mitochondrial functional
parameters, status of antioxidant enzymes and accumulation of oxidative damage markers were measured in the four groups of
rats. A significant decrease in complex IV activity and a loss of transmembrane potential and phosphorylation capacity along
with an increased accumulation of oxidative damage markers and compromised antioxidant enzyme status were noticed in aged
rat brain mitochondria as compared to that in young controls, but in aged rats supplemented with oral antioxidants the mitochondrial
alterations were largely prevented. Antioxidant supplementation in young rats had no effect on mitochondrial parameters investigated
in this study. The results have implications in biochemical and functional deficits of brain during aging as well as in neurodegenerative
disorders. 相似文献
6.
Duangdao Nantakomol Attakorn Palasuwan Mallika Chaowanathikhom Suphan Soogarun Mallika Imwong 《European journal of haematology》2012,89(5):423-429
In response to oxidative stress and during apoptosis, cells often shed microparticles (MPs), submicron elements carrying phosphatidylserine and protein antigens. Glucose‐6‐phosphate dehydrogenase (G6PD)‐deficient cells are extremely sensitive to oxidative damage that may lead to the formation of MPs. To determine whether G6PD deficiency alters membrane phospholipid asymmetry and increases MPs production, we determined the concentrations and cellular origins of MPs in G6PD‐deficient individuals using flow cytometry. G6PD‐deficient individuals showed an increase in circulating MPs concentrations as compared with G6PD‐normal individuals [1051/μL (865–2532/μL) vs. 258/μL (235–575/μL), P < 0.01]. MPs concentrations were significantly increased with the severity of G6PD deficiency. Median MPs concentrations from individuals with severe G6PD deficiency, and individuals with moderate G6PD deficiency were 2567/μL (1216–2532/μL) and 984/μL (685–2107/μL), respectively (P < 0.01). Importantly, G6PD enzymatic activity was significantly correlated with MPs concentrations with r2 = 0.731. MPs found in G6PD deficiency individuals were largely derived from red blood cells (RBCs) (45%) and platelets (30%). Additionally, Atomic Force Microscopy was used to study the morphology and measures the diameter of MPs found in G6PD‐deficient individuals. The mean (SD) width and height of RMPs were 0. 41 (0.18) and 2.04 (0.14) μm, respectively. Together, these results indicate that MP concentration is significantly correlated with G6PD enzymatic activity and is increased in G6PD‐deficient as compared with G6PD‐normal individuals. Our data also provide an evidence for an alteration in cell membrane associated with a decreased in G6PD activity. However, the significance of MPs in G6PD deficiency needs further clarification. 相似文献
7.
Myles E. Lee Mallika Tamboli Anthony W. Lee 《Texas Heart Institute journal / from the Texas Heart Institute of St. Luke's Episcopal Hospital, Texas Children's Hospital》2014,41(2):195-197
One difficulty with external repair of left ventricular rupture after mitral valve replacement is collateral bleeding in friable myocardium adjacent to the rupture. The bleeding is caused by tension on the closing sutures, whether or not pledgets have been used.We report the case of a 69-year-old woman who underwent an uneventful mitral valve replacement. After cardiopulmonary bypass was terminated, brisk bleeding started from high in the posterior left ventricular wall, typical of a type III defect. We undertook external repair, placing a plug of Teflon felt into the cavity of the rupture and sandwiching it into place with pledgeted mattress and figure-of-8 sutures. The space occupied by the plug decreased the distance needed to obliterate the defect and thereby reduced the tension on the sutures necessary to achieve hemostasis. This simple technique enabled closure of the defect and avoided collateral tears that would have compromised an otherwise successful repair. Two years postoperatively, the patient had normal mitral valve function and no left ventricular aneurysm. In addition to reporting the patient''s case, we review the types of left ventricular rupture that can occur during mitral valve replacement and discuss the various repair options. 相似文献
8.
9.
Guthmann JP Pittet A Lesage A Imwong M Lindegardh N Min Lwin M Zaw T Annerberg A de Radiguès X Nosten F 《Tropical medicine & international health : TM & IH》2008,13(1):91-98
Objective To assess the efficacy of chloroquine in the treatment of Plasmodium vivax malaria in in Dawei District, southern Myanmar.
Methods Enrolled patients at Sonsinphya clinic >6 months of age were assessed clinically and parasitologically every week for 28 days. To differentiate new infections from recrudescence, we genotyped pre- and post-treatment parasitaemia. Blood chloroquine was measured to confirm resistant strains.
Results Between December 2002 and April 2003, 2661 patients were screened, of whom 252 were included and 235 analysed. Thirty-four per cent (95% CI: 28.1–40.6) of patients had recurrent parasitaemia and were considered treatment failures. 59.4% of these recurrences were with a different parasite strain. Two (0.8%) patients with recurrences on day 14 had chloroquine concentrations above the threshold of 100 ng/ml and were considered infected with chloroquine resistant parasites. 21% of failures occurred during the first 3 weeks of follow-up: early recurrence and median levels of blood chloroquine comparable to those of controls suggested P. vivax resistance.
Conclusions Plasmodium vivax resistance to chloroquine seems to be emerging in Dawei, near the Thai-Burmese border. While chloroquine remains the first-line drug for P. vivax infections in this area of Myanmar, regular monitoring is needed to detect further development of parasite resistance. 相似文献
Methods Enrolled patients at Sonsinphya clinic >6 months of age were assessed clinically and parasitologically every week for 28 days. To differentiate new infections from recrudescence, we genotyped pre- and post-treatment parasitaemia. Blood chloroquine was measured to confirm resistant strains.
Results Between December 2002 and April 2003, 2661 patients were screened, of whom 252 were included and 235 analysed. Thirty-four per cent (95% CI: 28.1–40.6) of patients had recurrent parasitaemia and were considered treatment failures. 59.4% of these recurrences were with a different parasite strain. Two (0.8%) patients with recurrences on day 14 had chloroquine concentrations above the threshold of 100 ng/ml and were considered infected with chloroquine resistant parasites. 21% of failures occurred during the first 3 weeks of follow-up: early recurrence and median levels of blood chloroquine comparable to those of controls suggested P. vivax resistance.
Conclusions Plasmodium vivax resistance to chloroquine seems to be emerging in Dawei, near the Thai-Burmese border. While chloroquine remains the first-line drug for P. vivax infections in this area of Myanmar, regular monitoring is needed to detect further development of parasite resistance. 相似文献
10.
Rebecca E. Conway Camilo Rojas Jesse Alt Zora Nováková Spencer M. Richardson Tori C. Rodrick Julio L. Fuentes Noah H. Richardson Jonathan Attalla Samantha Stewart Beshoy Fahmy Cyril Barinka Mallika Ghosh Linda H. Shapiro Barbara S. Slusher 《Angiogenesis》2016,19(4):487-500
Prostate-specific membrane antigen (PSMA) is a membrane-bound glutamate carboxypeptidase expressed in a number of tissues. PSMA participates in various biological functions depending on the substrate available in the particular tissue; in the brain, PSMA cleaves the abundant neuropeptide N-acetyl-aspartyl-glutamate to regulate release of key neurotransmitters, while intestinal PSMA cleaves polyglutamated peptides to supply dietary folate. PSMA expression is also progressively upregulated in prostate cancer where it correlates with tumor progression as well as in tumor vasculature, where it regulates angiogenesis. The previous research determined that PSMA cleavage of small peptides generated via matrix metalloprotease-mediated proteolysis of the extracellular matrix protein laminin potently activated endothelial cells, integrin signaling and angiogenesis, although the specific peptide substrates were not identified. Herein, using enzymatic analyses and LC/MS, we unequivocally demonstrate that several laminin-derived peptides containing carboxy-terminal glutamate moieties (LQE, IEE, LNE) are bona fide substrates for PSMA. Subsequently, the peptide products were tested for their effects on angiogenesis in various models. We report that LQ, the dipeptide product of PSMA cleavage of LQE, efficiently activates endothelial cells in vitro and enhances angiogenesis in vivo. Importantly, LQE is not cleaved by an inactive PSMA enzyme containing an active site mutation (E424S). Endothelial cell activation by LQ was dependent on integrin beta-1-induced activation of focal adhesion kinase. These results characterize a novel PSMA substrate, provide a functional rationale for the upregulation of PSMA in cancer cells and tumor vasculature and suggest that inhibition of PSMA could lead to the development of new angiogenic therapies. 相似文献