Preparation of Crosslinked Poly(2‐bromoethyl methacrylate) Microspheres and Decoration of Their Surfaces with Functional Polymer Brushes

Synthesis and crosslinking copolymerization of 2‐bromoethylmethacrylate in aqueous suspension is described for preparing bromoalkyl‐functional microbeads (125–420 µm). Highly transparent microspheres with a density of accessible bromoethyl groups of 1.55 mmol · g^?1 were prepared in the suspension, stabilized with poly(N‐vinyl pyrrolidone), by using methyl methacrylate as diluting co‐monomer and ethylene glycol dimethacrylate as crosslinker. Bromoalkyl groups on the microparticles were employed as initiation sites for either surface‐initiated ATRP of glycidyl methacrylate or ring‐opening polymerization of 2‐methyl‐2‐oxazoline to generate epoxy‐ and N‐acetylethyleneimine‐functional hairy grafts, tethered to the particle surfaces with hydrolytically stable linkages.

     

Renal safety and extrahepatic defluorination of sevoflurane in hepatic transplantations

BACKGROUND: The main metabolic pathway for defluorination of sevoflurane in the liver produces inorganic fluoride (Fl). The metabolism and effect of sevoflurane on the kidney is not clear during anhepatic phase in liver transplantation. The goal of the present study was to investigate the metabolism and renal effect of sevoflurane by measuring plasma and urine inorganic fluoride, urinary N-acetyl-glucosaminidase (NAG), and plasma creatinine levels in patients undergoing liver transplantations. METHODS: After institutional approval and informed consent, we studied nine cases of orthotopic liver transplantation after anesthesia was induced with 5 mg . kg(-1) thiopental, 1 mug . kg(-1) fentanyl intravenously, the trachea was intubated after vecuronium bromide 0.1 mg . kg(-1). Anesthesia was maintained with sevoflurane (2%), O(2), and N(2)O at a total gas flow of 6 L . min(-1) using a semiclosed circle system with a sodalime canister. Blood and urine samples were obtained to measure plasma and urine fluoride concentrations and urinary NAG excretions before induction (P0), hourly during resection (P1, P2, P3), every 15 minutes during anhepatic phase (A1, A2, A3), hourly after reperfusion (neohepatic phase) (N1, N2, N3), and postoperative first hour (Po1). Preoperative (T0) and postoperative day 1 (T1), 3 (T3), 7 (T7) plasma blood urea nitrogen (BUN) and creatinine (Cr) levels were also recorded. RESULTS: Mean duration of surgery was 9:06 +/- 0:09 hours. Mean inorganic fluoride concentrations in plasma were in the range of 0.71 +/- 0.30 to 28.73 +/- 3.31 mumole . L(-1). In P3, N1, N2, N3, increases in plasma inorganic fluoride concentrations were significant (P < .05) and reached a peak value at Po1. The mean urine inorganic fluoride concentrations were 12.49 +/- 2.04 to 256.7 +/- 49.62 mumole . L(-1). In A2, A3, N1, N2, and N3, mean urine inorganic fluoride concentrations were significantly increased (P < .05) and the peak value was observed at Po1. Mean NAG concentrations in urine varied (5.6 +/- 1.6 IU . L(-1) to 12.5 +/- 1.14 IU . L(-1)) and peak level was observed at 30 minutes of the anhepatic phase (A2), which did not exceed the normal values for urine NAG levels (1.5 to 6.1 U . L(-1)). No impairment was observed in serum BUN and creatinine levels at any time. While there was only a slight increase in NAG during anhepatic phase, there was no change in plasma F1. CONCLUSIONS: Sevoflurane seemed to have minimal effect on kidney functions of BUN and Cr levels during liver transplantation. Although urine F1 and NAG levels increased during the anhepatic phase plasma F1, BUN, and Cr levels did not, suggesting that renal F1 production may occur in the absence of hepatic function. The renal effect of sevoflurane in chronic liver disease is controversial and must be investigated in further studies.     

Vascular endothelial growth factor (VEGF), matrix metalloproteinase-9 (MMP-9), and thrombospondin-1 (TSP-1) expression in urothelial carcinomas

Angiogenesis is a multistep process that depends on the balance of proangiogenic factors and inhibitors as well as on interactions with the extracellular matrix. We examined the immunohistochemical expression of the defining angiogenic agents, vascular endothelial growth factor (VEGF) and matrix metalloproteinase-9 (MMP-9), and the antiangiogenic agent thrombospondin-1 (TSP-1) in 131 patients with urethelial carcinoma and correlated their expression levels with clinicopathological parameters. VEGF and MMP-9 expression was higher in high-grade tumors than in low-grade tumors (p=0.000 and p=0.001, respectively), whereas the reverse was true for TSP-1 (p=0.000). VEGF and MMP-9 expression was higher in deeper tumors compared to superficial tumors and in invasive tumors compared to non-invasive tumors (p=0.001 and p=0.001, respectively), while TSP-1 was lower (p=0.000). We could differentiate 22 of 41 muscle-invasive (T2) cases as superficial (T2a; n=7) or deep (T2b; n=15), but no difference was found between them regarding VEGF, MMP-9, or TSP-1 expression (p=0.783, p=0.289, and p=0.783, respectively). There was a positive correlation between VEGF and MMP-9 expression (p=0.008, r=0.23) but a negative correlation between MMP-9 and TSP-1 expression (p=0.014, r=-0.21). Increased VEGF and MMP-9 expression as well as decreased TSP-1 expression may play considerable roles in the invasion and differentiation of urothelial carcinoma.     

Matrix metalloproteinase-2 (MMP-2) and MMP-9 expression in invasive ductal carcinoma of the breast

Matrix metalloproteinase-2 (MMP-2) and MMP-9 are gelatinases that play a role in the invasion and metastasis of cancer through the destruction of the basal membrane and extracellular matrix. In this study, we investigated the immunohistochemical expression of MMP-2 and MMP-9 and the correlation between the expression levels and prognostic clinicopathological parameters in 140 patients with invasive ductal carcinoma (IDC). The staining scores for MMP-9 were negative in 21 cases (15%), mild in 27 cases (19%), and strong in 92 cases (66%). MMP-9 expression was increased in high-grade (p=0.001), triple-negative (ER, PR, HER2 negative) (p=0.006), and ER-negative tumors (p=0.004) and tumors with distant metastases (p=0.028). MMP-9 expression was increased in cases with HER2 over-expression/amplification, but no statistically significant difference was found (p=0.215). No correlation was found between lymph node metastasis or tumor size and MMP-9 expression (p=0.492 and p=0.448, respectively). The staining scores for MMP-2 in 140 cases were negative in 10 cases (7%), mild in 25 cases (18%), and strong in 105 cases (75%). MMP-2 expression was increased in ER-negative and high-grade tumors in the lymph node-negative group (p=0.025 and 0.026, respectively). High MMP-9 expression was associated with a shorter disease-free survival and overall survival times (p=0.042 and p=0.046, respectively). In conclusion, increased MMP-9 expression is related to poor prognostic clinicopathological factors in IDC, and hence, it can be utilized as a supplementary prognostic marker. The role of MMP-2 expression in the prognosis of IDC is rather limited.     

Stimulation of cysteinyl leukotriene production in mast cells by heat shock and acetylsalicylic acid

Immunoglobulin (Ig) E-dependent activation of mast cells is central to the allergic response. The engagement of IgE-occupied receptors initiates a series of molecular events that causes the release of preformed, and de novo synthesis of, allergic mediators. Cysteinyl leukotrienes are able to contract airway smooth muscle and increase mucus secretion and vascular permeability and recruit eosinophils. Mast cells have also recently been recognized as active participants in innate immune responses. Heat stress can modulate innate immunity by inducing stress proteins such as heat-shock proteins (HSPs). We previously demonstrated that treatment of mast cells with heat shock or acetylsalicylic acid results in an increase of TNF-alpha and IL-6 release. This effect was paralleled by expression of HSP70. In the current study, we further investigated the effects of heat shock and acetylsalicylic acid on the activation of mast cells and the release of cysteinyl leukotrienes. In mouse mast cells, derived from a culture of bone marrow cells, responsiveness to heat shock, acetylsalicylic acid and exogenous or endogenous HSP70 was monitored by measuring leukotriene C4 release. We show that after heat shock treatment and exposure to acetylsalicylic acid leukotriene production was increased. Moreover, exogenous rHSP70 also induced leukotriene production. Because it has been reported that leukotriene production in mast cells may be mediated by Toll like receptor (TLR) activation, and HSP70 also activates TLRs signaling, we further explored these issues by using mast cells that are not able to produce HSP70, i.e. heat shock factor-1 (HSF-1) knockout cells. We found that in HSF-1 knockout bone marrow derived mast cells, heat shock and acetylsalicylic acid failed to induce release of leukotrienes. Moreover, in wild type cells the surface expression of TLR4 was attenuated, whereas the intracellular expression was up-regulated. We conclude that heat shock and acetylsalicylic acid induce the production and release of heat shock proteins from mast cells, which in turn stimulate leukotriene synthesis through activation of TLR4.