Platelet storage lesion: a new understanding from a proteomic perspective

Platelet storage and availability for the purposes of transfusion are currently restricted by a markedly short shelf life of 5 to 7 days owing to an increased risk of bacterial growth and storage-related deterioration called the platelet storage lesion. Because most bacteria grow to confluence within 5 days during storage at room temperature, there is little increased risk of bacterial overgrowth with testing in place, and the only remaining issue is the quality of platelets during the extended storage. Although the manifestations of the storage lesion have been well studied using a variety of in vitro measures, the precise biochemical pathways involved in the initiation and progression of this process have yet to be identified. Proteomics has emerged as a powerful tool to identify and monitor changes during platelet storage and, in combination with biochemical and physiologic studies, facilitates the development of a sophisticated mechanistic view. In this review, we summarize recent experimental work that has led to a detailed overview of protein changes linked to platelet functions and signaling pathways, providing potential targets for inhibitors to ameliorate the storage lesion.     

Cellular Uptake of Cationic Polymer-DNA Complexes Via Caveolae Plays a Pivotal Role in Gene Transfection in COS-7 Cells

Purpose Knowledge about the uptake mechanism and subsequent intracellular routing of non-viral gene delivery systems is important for the development of more efficient carriers. In this study we compared two established cationic polymers pDMAEMA and PEI with regard to their transfection efficiency and mechanism of cellular uptake. Materials and Methods The effects of several inhibitors of particular cellular uptake routes on the uptake of polyplexes and subsequent gene expression in COS-7 cells were investigated using FACS and transfection. Moreover, cellular localization of fluorescently labeled polyplexes was assessed by spectral fluorescence microscopy. Results Both pDMAEMA- and PEI-complexed DNA showed colocalization with fluorescently-labeled transferrin and cholera toxin after internalization by COS-7 cells, which indicates uptake via the clathrin- and caveolae-dependent pathways. Blocking either routes of uptake with specific inhibitors only resulted in a marginal decrease in polyplex uptake, which may suggest that uptake routes of polyplexes are interchangeable. Despite the marginal effect of inhibitors on polyplex internalization, blocking the caveolae-mediated uptake route resulted in an almost complete loss of polyplex-mediated gene expression, whereas gene expression was not negatively affected by blocking the clathrin-dependent route of uptake. Conclusions These results show the importance of caveolae-mediated uptake for successful gene expression and have implications for the rational design of non-viral gene delivery systems.     

Anesthetic considerations for intraoperative management of cerebrovascular disease in neurovascular surgical procedures

Despite new surgical methods and interventions a considerable number of patients who undergo neurovascular procedures emergently or electively have substantial mortality, morbidity, and disability. Sound knowledge of pathophysiology of cerebral hypoperfusion, reliable and timely information from monitoring devices, and appropriate choice of therapeutic intervention is essential for successful anesthetic management of these patients. The management of perioperative vasospasm and temporary ischemia during aneurysm clipping require an understanding of cerebral vascular pathophysiology and neuroprotective measures.     

Abnormal hippocampal neurochemistry in smokers: evidence from proton magnetic resonance spectroscopy at 3 T

OBJECTIVE: In animals, nicotine, the primary psychoactive constituent of tobacco smoke, reduces neurogenesis and increases cell loss in both hippocampus and cortex. Accordingly, tobacco smoking has been linked to reduced performance on cognitive paradigms requiring attention and working memory in humans. However, few prior studies have tested for evidence of structural brain alterations in human tobacco smokers. In this study, proton magnetic resonance spectroscopy was used to assess the effects of chronic smoking on neuronal integrity of the hippocampus and anterior cingulate cortex (ACC). METHODS: Absolute concentrations of N-acetylaspartate, total choline (tCho), and total creatine were measured in the left hippocampus and ACC in 13 chronic tobacco smokers and 13 nonsmokers matched for age, sex, and education. RESULTS: The N-acetylaspartate concentration was significantly reduced in smokers relative to nonsmokers in the left hippocampus but not in the ACC. There were no group differences in the tCho and total creatine concentrations in either voxel. However, ACC tCho concentration was positively correlated with magnitude of lifetime exposure to tobacco smoke (pack-years). CONCLUSION: The results are consistent with prior observations of hippocampal neuronal damage in rodents receiving nicotine and working memory deficits in human tobacco smokers. The positive relationship between tCho and lifetime tobacco exposure suggests that a component of tobacco smoke, presumably nicotine, may increase cortical membrane turnover or modify cell density. Together, these results add to growing evidence that nicotine exerts neurotoxic effects in human brain, although an a priori nature of the findings cannot be ruled out.     

Laparoscopic distal pancreatic resection: Our own experience in the treatment of solid tumors

A laparoscopic resection is a new treatment for pancreatic tumors. Articles by surgeons who are writing about their first experience in carrying out this treatment have appeared in the literature, reporting that laparoscopic surgery can be used for the treatment of pancreatitis, benign lesions, and solid tumors. This is a study of three patients with pancreatic tumors who were treated by means of a laparoscopic distal pancreatic resection with preservation of the spleen and splenic vessels. In three cases a laparoscopic distal resection was performed for the tumor. The histologic examinations showed one insulinoma and two mucinous cystadenomas. No patient suffered from intra- or postoperative complications. A laparoscopic resection of the distal pancreas is a new alternative for the treatment of pancreatic tumors. This method takes advantage of the benefits of minimally invasive surgery.     

Modulation of detoxification enzymes by watercress: in vitro and in vivo investigations in human peripheral blood cells

Background

Epidemiological studies indicate that consumption of cruciferous vegetables (CV) can reduce the risk of cancer. Supposed mechanisms are partly the inhibition of phase I and the induction of phase II enzymes.

Aim

The aim of this study was to investigate in vitro and in vivo effects of watercress (WC), a member of the CV family, on chemopreventive parameters using human peripheral blood mononuclear cells (PBMC) as surrogate cells. We investigated the hypothesis that WC reduces cancer risk by inducing detoxification enzymes in a genotype-dependent manner.

Methods

In vitro gene expression and enzyme activity experiments used PBMC incubated with a crude extract from fresh watercress (WCE, 0.1–10 μL/mL with 8.2 g WC per 1 mL extract) or with one main key compound phenethyl isothiocyanate (PEITC, 1–10 μM). From an in vivo perspective, gene expression and glutathione S-transferase (GST) polymorphisms were determined in PBMC obtained from a human intervention study in which subjects consumed 85 g WC per day for 8 weeks. The influence of WC consumption on gene expression was determined for detoxification enzymes such as superoxide dismutase 2 (SOD2) and glutathione peroxidase 1 (GPX1), whilst the SOD and GPX activities in red blood cells were also analysed with respect to GST genotypes.

Results

In vitro exposure of PBMC to WCE or PEITC (24 h) increased gene expression for both detoxification enzymes GPX1 (5.5-fold, 1 μL/mL WCE, 3.7-fold 1 μM PEITC) and SOD2 (12.1-fold, 10 μL/mL WCE, 7.3-fold, 10 μM PEITC), and increased SOD2 activity (1.9-fold, 10 μL/mL WCE). The WC intervention had no significant effect on in vivo PBMC gene expression, as high individual variations were observed. However, a small but significant increase in GPX (p = 0.025) and SOD enzyme activity (p = 0.054) in red blood cells was observed in GSTM1*0, but not in GSTM1*1 individuals, whilst the GSTT1 genotype had no impact.

Conclusion

The results indicate that WC is able to modulate the enzymes SOD and GPX in blood cells in vitro and in vivo, and suggest that the capacity of moderate intake of CV to induce detoxification is dependent in part on the GSTM1 genotype.     

Combined treatment with Denbinobin and Fas ligand has a synergistic cytotoxic effect in human pancreatic adenocarcinoma BxPC-3 cells

Background and purpose:

Human pancreatic carcinoma is a highly malignant cancer. Previous studies have shown that the decoy receptor 3 (DcR3) for Fas ligand (FasL) plays significant roles in tumour progression and immune suppression. In the present study, we evaluated the anti-cancer activity of a natural compound, denbinobin (5-hydroxy-3,7-dimethoxy-1,4-phenanthraquinone), through decreasing DcR3 levels in human pancreatic adenocarcinoma cell lines.

Experimental approach:

We used immunoprecipitation and ELISA assays to examine DcR3 levels, and used FACS to determine the percentage of cells with a sub-G1 DNA content.

Key results:

AsPC-1 and BxPC-3 human pancreatic cancer cells express high levels of DcR3. Denbinobin concentration-dependently decreased DcR3 levels in BxPC-3 cells. MTT and flow cytometry assays indicated that BxPC-3 was FasL-resistant because high concentrations (100 ng·mL⁻¹) of soluble FasL did not inhibit cell growth. However, combinations of denbinobin (3 µmol·L⁻¹) with lower concentrations of soluble FasL (10, 30 and 50 ng·mL⁻¹) or membrane-bound FasL, were synergistic on cell growth inhibition and apoptosis. Exogenous excess DcR3 reversed this synergistic effect. We observed no significant increase in the levels of surface Fas, cleaved forms of caspase-8, -3, -9, Bax, Bid, Bcl-xL, cytochrome c or mitochondrial membrane potentials following denbinobin treatment. However, denbinobin treatment increased the levels of apoptosis-inducing factor.

Conclusions and implications:

Denbinobin and FasL trigger a synergistic cytotoxic effect in human pancreatic adenocarcinoma cells. Denbinobin mediated a decrease in levels of DcR3, which played a major role in this synergistic effect, and also increased caspase-independent apoptosis, via apoptosis-inducing factor.