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In vivo selection of phage display libraries have been exploited successfully in the past to isolate various high affinity conformationally strained cyclic peptide ligands (CX(5-7)C, peptides flanked by a cysteine residue on each ...
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In vivo selection of phage display libraries have been exploited successfully in the past to isolate various high affinity conformationally strained cyclic peptide ligands (CX(5-7)C, peptides flanked by a cysteine residue on each side) for integrin receptors capable of selectively homing to tumor vasculatures. Previously, such phase display library studies have shown that integrin alpha 5 beta 1 binds with high affinity to cyclic peptides containing CRGDGWC motif. Herein we show that a lipopeptide with just the RGDGW motif (without the flanking cysteine groups) covalently attached to the lysine residue of a monolysinylated cationic amphiphile (RGDGWK-lipopeptide 1) delivers genes to cultured cells preferably via alpha 5 beta 1 integrins. Importantly, remarkable tumor growth inhibition was observed when the electrostatic complex of the RGDGWK-lipopeptide 1 and the anti-cancer p53 gene was intravenously administered in C57BL/6J mice bearing the aggressive B16F10 tumor. Immunohistochemical staining of mice tumor cryosections with vasculature markers combined with monitoring expression of the green fluorescence protein in the same tumor cryosections revealed that the RGDGWK-lipopeptide 1 targets genes to tumor vasculatures. The colocalization of the TUNEL (terminal deoxyuridine triphosphate nick-end labeling, a widely used marker of apoptosis) and VE-cadherin (markers of tumor endothelial cells) positive cells in tumor cryosections support the notion that the remarkable tumor growth inhibition property of the RGDGWK-lipopeptide 1:p53 complex is initiated through apoptosis of the tumor endothelial cells.
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BACKGROUND & AIMS: Protease activation within the pancreatic acinar cell is a key early event in acute pancreatitis and may require low pH intracellular compartments. Clinical studies suggest that acidosis may affect the risk for developing pancreatitis. We hypothesized that exposure to an acid load might sensitize the acinar cell to secretagogue-induced pancreatitis. METHODS: Secretagogues (cerulein, carbachol, and bombesin) can induce protease activation in acinar cells at high (100 nmol/L, 1 mmol/L, and 10 micromol/L, respectively) but not at physiologically relevant concentrations. The effects of decreasing extracellular pH (pHe) in early secretagogue-induced pancreatitis (zymogen activation and injury) were examined in rats (1) in vitro with isolated acini and (2) in vivo with an acid challenge. RESULTS: In acini, lowering pHe from 7.6 to 6.8 enhanced secretagogue-induced zymogen activation and injury, but did not affect secretion. For cerulein, this sensitization was seen over a range of concentrations (0.01-100.00 nmol/L). However, reduced pHe alone had no effect on zymogen activation, amylase secretion, or cell injury. We have reported that zymogen activation is mediated by the vacuolar ATPase (vATPase), a proton transporter. vATPase inhibition, using concanamycin (100 nmol/L), blocked the low pHe effects on zymogen activation. An acute acid load given in vivo enhanced cerulein-induced (50 microg/kg) trypsinogen activation and pancreatic edema. CONCLUSION: These studies suggest that acid challenge sensitizes the pancreatic acinar cell to secretagogue-induced zymogen activation and injury and may increase the risk for the development and severity of acute pancreatitis....
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BACKGROUND & AIMS: Protease activation within the pancreatic acinar cell is a key early event in acute pancreatitis and may require low pH intracellular compartments. Clinical studies suggest that acidosis may affect the risk for developing pancreatitis. We hypothesized that exposure to an acid load might sensitize the acinar cell to secretagogue-induced pancreatitis. METHODS: Secretagogues (cerulein, carbachol, and bombesin) can induce protease activation in acinar cells at high (100 nmol/L, 1 mmol/L, and 10 micromol/L, respectively) but not at physiologically relevant concentrations. The effects of decreasing extracellular pH (pHe) in early secretagogue-induced pancreatitis (zymogen activation and injury) were examined in rats (1) in vitro with isolated acini and (2) in vivo with an acid challenge. RESULTS: In acini, lowering pHe from 7.6 to 6.8 enhanced secretagogue-induced zymogen activation and injury, but did not affect secretion. For cerulein, this sensitization was seen over a range of concentrations (0.01-100.00 nmol/L). However, reduced pHe alone had no effect on zymogen activation, amylase secretion, or cell injury. We have reported that zymogen activation is mediated by the vacuolar ATPase (vATPase), a proton transporter. vATPase inhibition, using concanamycin (100 nmol/L), blocked the low pHe effects on zymogen activation. An acute acid load given in vivo enhanced cerulein-induced (50 microg/kg) trypsinogen activation and pancreatic edema. CONCLUSION: These studies suggest that acid challenge sensitizes the pancreatic acinar cell to secretagogue-induced zymogen activation and injury and may increase the risk for the development and severity of acute pancreatitis.
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BACKGROUND: Antibodies (Ab) responses to major and minor human leukocyte antigen loci may impact graft survival after organ transplantation. METHODS: A ProtoArray platform was used to study 37 serum samples from 15 renal transplan...
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BACKGROUND: Antibodies (Ab) responses to major and minor human leukocyte antigen loci may impact graft survival after organ transplantation. METHODS: A ProtoArray platform was used to study 37 serum samples from 15 renal transplant patients with (n=10) and without (n=5) acute rejection (AR) and seven normal controls, and the clinical relevance of major histocompatibility complex class I chain-related gene-A (MICA)-Ab measurements were investigated. Biopsy immunohistochemistry was conducted for localization of the MICA antigen. RESULTS: De novo MICA-Ab were detected in 11 of the 15 transplant patients in this study, irrespective of interval acute graft rejection. Mean MICA-Ab signal intensity was higher in transplant patients with C4d+AR (121.4) versus C4d-AR (4.3), correlated with donor-specific Ab to human leukocyte antigens (r=0.66, P=0.0078), was not elevated in cellular rejections, and correlated with decline in graft function over the subsequent year (r=0.73, P=0.0022). Integrative genomics accurately predicted localization of the MICA antigen to the glomerulus in the normal kidney (Li et al. Proc Natl Acad Sci USA 2009; 106: 4148), because this was confirmed subsequently by immunohistochemistry. CONCLUSIONS: Integrative genomics analysis of ProtoArray data is a powerful tool to ascertain de novo antibody responses after renal transplantation and to accurately predict the anatomical location of the target renal antigens. This proof-of-concept study on MICA measurements by ProtoArray demonstrates that antibody responses modulated to MICA after transplantation in patients, irrespective of graft rejection, may be high at the time of humoral rejection and may not be elevated in cellular rejection. Understanding that MICA is preferentially localized to the glomerulus may explain both immunoregulatory and pathogenic roles for MICA after transplantation.
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Over the past decade, it has been shown that glucose induces oxidative and inflammatory stress and that insulin inhibits oxidative and inflammatory stress. Thus, glucose causes an increase in reactive oxygen species generation by ...
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Over the past decade, it has been shown that glucose induces oxidative and inflammatory stress and that insulin inhibits oxidative and inflammatory stress. Thus, glucose causes an increase in reactive oxygen species generation by polymorphonuclear and mononuclear cells and an increase in plasma concen-tration of thiobarbituric acid-reducing substances, in addition to inducing an increase in intranuclear nuclear factor kappa-B binding and a reduction in inhibitor kappa B-alpha (1).
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Vascular complications of hypoglyce-mia have to be tackled with greater urgency now because two recent trials of intensified diabetes treatment with insulin, the Action to Control Cardiovascular Risk in Diabetes (ACCORD) trial and...
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Vascular complications of hypoglyce-mia have to be tackled with greater urgency now because two recent trials of intensified diabetes treatment with insulin, the Action to Control Cardiovascular Risk in Diabetes (ACCORD) trial and Veteran's Affairs Diabetes Trial (VADT), did not demonstrate a reduction in cardiovascular events (1,2). In fact, the intensified insulin treatment arm of the ACCORD trial had to be halted because of an increase in overall mortality, despite a reduction in acute myocardial infarction. The rate of hypoglycemia in both trials was significantly increased with intensified insulin treatment. Although the analysis of the ACCORD data did not support the hypothesis that the increased mortality in the study was a result of hypoglycemia, the fact that hypoglycemia may often be asymptomatic leaves us with the possibility that it may be responsible.
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Minimally invasive, open-access surgical techniques are being increasingly applied to facilitate recovery and reduce post-operative complications, such as pain, which are inherently associated with large incisions. These technique...
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Minimally invasive, open-access surgical techniques are being increasingly applied to facilitate recovery and reduce post-operative complications, such as pain, which are inherently associated with large incisions. These techniques aim to combine the benefits of small incisions with three-dimensional appreciation of the anatomy. We describe a mini-open modification of anterior, open-approach hernio-plasty for repair of small-to-medium reducible inguinal hernias.
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