Towards high-quality peri-operative care: a global perspective.

Article 25 of the United Nations' Universal Declaration of Human Rights enshrines the right to health and well-being for every individual. However, universal access to high-quality healthcare remains the purview of a handful of wealthy nations. This is no more apparent than in peri-operative care, where an estimated five billion individuals lack access to safe, affordable and timely surgical care. Delivery of surgery and anaesthesia in low-resource environments presents unique challenges that, when unaddressed, result in limited access to low-quality care. Current peri-operative research and clinical guidance often fail to acknowledge these system-level deficits and therefore have limited applicability in low-resource settings. In this manuscript, the authors priority-set the need for equitable access to high-quality peri-operative care and analyse the system-level contributors to excess peri-operative mortality rates, a key marker of quality of care. To provide examples of how research and investment may close the equity gap, a modified Delphi method was adopted to curate and appraise interventions which may, with subsequent research and evaluation, begin to address the barriers to high-quality peri-operative care in low- and middle-income countries.

Analysis of Stable Isotope Assisted Metabolomics Data Acquired by High Resolution Mass Spectrometry.

Stable isotope assisted metabolomics (SIAM) uses stable isotope tracers to support studies of biochemical mechanisms. We report a suite of data analysis algorithms for automatic analysis of SIAM data acquired on a high resolution mass spectrometer. To increase the accuracy of isotopologue assignment, metabolites detected in the unlabeled samples were used as reference metabolites to generate possible isotopologue candidates for analysis of peaks detected in the labeled samples. An iterative linear regression model was developed to deconvolute the overlapping isotopic peaks of isotopologues present in a full MS spectrum, where the threshold for the weight factor was determined by a simulation study assuming different levels of Gaussian white noise contamination. A normalization method enabling isotope ratio-based normalization was implemented to study the difference of isotopologue abundance distribution between sample groups. The developed method can analyze SIAM data acquired by direct infusion MS and LC-MS, and can handle metabolite tracers containing different tracer elements. Analysis of SIAM data acquired from mixtures of known compounds showed that the developed algorithms accurately identify metabolites and quantify stable isotope enrichment. Application of SIAM data acquired from a biological study further demonstrated the effectiveness and accuracy of the developed method for analysis of complex samples.

ORMOCHALCs: organically modified chalcogenide polymers for infrared optics.

A novel method combining elemental sulfur and selenium was developed, yielding crystalline sulfur-selenium compounds. The compounds were melted, and an organic comonomer added. Once the organic comonomer was consumed, the viscous compound was vitrified and allowed to cool yielding organic-inorganic hybrid polymers that are termed Organically Modified Chalcogenide (ORMOCHALC) polymers.

Akt inhibition upregulates FasL, downregulates c-FLIPs and induces caspase-8-dependent cell death in Jurkat T lymphocytes.

In T lymphocytes, the role of Akt in regulating Fas/Fas ligand (FasL)-mediated apoptotic signaling and death is not clearly understood. In this study, we observed that inhibition of Akt causes enhanced expression of FasL mRNA and protein and increased death-inducing signaling complex (DISC) formation with Fas-associated death domain (FADD) and procaspase-8 recruitment. Also, caspase-8 was activated at the DISC with accompanying decrease in c-FLIPs expression. FasL neutralizing antibody significantly decreased apoptotic death in the Akt-inhibited T cells. Additionally, Akt inhibition-induced Fas signaling was observed to link to the mitochondrial pathway via Bid cleavage. Further, inhibition of caspase-8 activity effectively blocked the loss of mitochondrial membrane potential and DNA fragmentation, suggesting that DISC formation and subsequent caspase-8 activation are critical initiating events in Akt inhibition-induced apoptotic death in T lymphocytes. These data demonstrate yet another important survival function governed by Akt kinase in T lymphocytes, which involves the regulation of FasL expression and consequent apoptotic signaling.

The green tea polyphenol (-)-epigallocatechin-3-gallate blocks nuclear factor-kappa B activation by inhibiting I kappa B kinase activity in the intestinal epithelial cell line IEC-6.

The I kappa B kinase complex (IKK) mediates activation of the transcription factor nuclear factor-kappa B (NF-kappa B). We previously showed that green tea polyphenols inhibited endotoxin-mediated tumor necrosis factor-alpha (TNF alpha) production by blocking NF-kappa B activation. In this study, we evaluated whether green tea polyphenols inhibit NF-kappa B by blocking IKK activity. We assessed IKK activity by detecting changes in phosphorylation of an I kappa B alpha-glutathione S-transferase (GST) fusion protein. IEC-6 cells pretreated with an extract of green tea polyphenols (GrTPs; 0--0.4 mg/ml) had diminished TNF alpha-induced IKK and NF-kappa B activity. Of the various GrTPs, (-)-epigallocatechin-3-gallate (EGCG) was the most potent inhibitor. We next examined whether EGCG inhibited activated IKK. In cytosolic extracts of TNF alpha-stimulated cells, EGCG inhibited phosphorylation of I kappa B alpha-GST (IC(50) > 18 microM) consistent with inhibition of IKK activity. Using other polyphenols, we showed that the gallate group was essential for inhibition, and antioxidants were ineffective in blocking activated IKK. Importantly, EGCG decreased IKK activity in cytosolic extracts of NIK transiently transfected cells. This latter finding showed that our findings were not related to nonspecific kinase activity. In conclusion, EGCG is an effective inhibitor of IKK activity. This may explain, at least in part, some of the reported anti-inflammatory and anticancer effects of green tea.

Green tea polyphenol extract attenuates inflammation in interleukin-2-deficient mice, a model of autoimmunity.

Green tea polyphenols (GrTP) have been previously shown to decrease endotoxin-induced tumor necrosis factor-alpha production and lethality in mice. Our present studies demonstrate that GrTP inhibit inflammatory responses and may be useful in treating chronic inflammatory states, such as inflammatory bowel disease. In this preliminary study, we examined whether GrTP decrease disease activity in interleukin-2-deficient (IL-2(-/-) mice. Eight-week old IL-2(-/-) C57BL/6J mice who were fed nonpurified diet were randomly assigned to receive water with GrTP (5 g/L) or water alone (control) for up to 6 wk. After 1 wk, explant colon and lamina propria lymphocyte (LPL) cultures were established from a subgroup of mice and supernatants collected. Culture supernatants from GrTP-treated mice showed decreased spontaneous interferon-gamma and tumor necrosis factor-alpha secretion compared with that of controls. At 6 wk, the GrTP group had less severe colitis as demonstrated by lower histologic scores and wet colon weights. This was associated with lower plasma levels of serum amyloid A, increased weight gain and improved hematocrits. These results show that GrTP attenuated inflammation in IL-2(-/-) mice and suggest a role for GrTP in treating chronic inflammatory diseases such as inflammatory bowel disease.

Inhibition of caspases in vivo protects the rat liver against alcohol-induced sensitization to bacterial lipopolysaccharide.

BACKGROUND: The mechanisms of liver sensitization by alcohol to Gram-negative bacterial lipopolysaccharide (LPS) remain elusive. The purpose of this study was two-fold: (1) to test the hypothesis that alcohol-enhanced liver apoptosis may be a sensitizing mechanism for LPS and (2) to further characterize the liver apoptotic response to alcohol. METHODS: Rats were fed a high-fat, alcohol-containing liquid diet for 14 weeks, treated with LPS (1.0 mg/kg of body weight, intravenously) or saline, followed by injection of a pan-caspase inhibitor IDN1965; N-[(1,3-dimethylindole-2-carbonyl)-valinyl]-3-amino-4-oxo-5-fluoropentanoic acid; 10 mg/kg of body weight, intraperitoneally or vehicle, and killed. The following parameters were assessed: plasma aspartate: 2-oxoglutarate aminotransferase activity (AST); liver histology and terminal deoxyribonucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) response; caspase-3, -8, and -9 activity; and mRNA and protein expression for two apoptosis-signaling molecules: Fas receptor and Fas ligand; and three apoptosis adaptors: Bax, Bcl-XL, and Bcl-2. RESULTS: Alcohol-feeding-induced liver steatosis, slightly increased caspases' activity, the number of TUNEL-positive nuclei, and facilitated the LPS necrotic effect without affecting mRNA expression of apoptosis signals and adaptors. LPS induced a significant increase in AST and the number of TUNEL-positive nuclei, both effects being more pronounced in alcohol-treated rats. LPS produced hepatic necrosis only in alcohol-treated rats. LPS effects were associated with up-regulation of mRNA expression for both apoptosis adaptors and signaling molecules. IDN1965 administration 3 hr after LPS injection strongly inhibited caspases' activity, particularly that of caspase-3. IDN1965 also abolished the increase in TUNEL-positive nuclei, reversed the effect of LPS on plasma AST in alcohol-treated rats, and prevented LPS-induced necrosis. CONCLUSIONS: (1) Alcohol-enhanced liver apoptosis may not involve regulatory steps at the transcriptional level. LPS-induced liver apoptosis seems to involve transcriptional regulation of several apoptosis adaptors. Therefore, alcohol and LPS may enhance liver apoptosis through different mechanisms. (2) Alcohol-enhanced liver apoptosis precedes and may facilitate the hepatic effects of LPS. LPS superimposed on alcohol further elevates the rate of apoptosis in the liver. This may exceed the phagocytosing capacity of the liver so that all the apoptotic cells are not phagocytosed, but rather die of necrosis.

How is the liver primed or sensitized for alcoholic liver disease?

This article represents the proceedings of a symposium at the 2000 ISBRA Meeting in Yokohama, Japan. The chairs were Hidekazu Tsukamoto and Yoshiyuki Takei. The presentations were (1) Tribute to Professor Rajendar K. Chawla, by Craig J. McClain; (2) Dysregulated TNF signaling in alcoholic liver disease, by Craig J. McClain, S. Joshi-Barve, D. Hill, J Schmidt, I. Deaciuc, and S. Barve; (3) The role of mitochondria in ethanol-mediated sensitization of the liver, by Anna Colell, Carmen Garcia-Ruiz, Neil Kaplowitz, and Jose C. Fernandez-Checa; (4) A peroxisome proliferator (bezafibrate) can prevent superoxide anion release into hepatic sinusoid after acute ethanol administration, by Hirokazu Yokoyama, Yukishige Okamura, Yuji Nakamura, and Hiromasa Ishii; (5) S-adenosylmethionine affects tumor necrosis factor-alpha gene expression in macrophages, by Rajendar K. Chawla, S. Barve, S. Joshi-Barve, W. Watson, W. Nelson, and C. McClain; (6) Iron, retinoic acid and hepatic macrophage TNFalpha gene expression in ALD, by Hidekazu Tsukamoto, Min Lin, Mitsuru Ohata, and Kenta Motomura; and (7) Role of Kupffer cells and gut-derived endotoxin in alcoholic liver injury, by N. Enomoto, K. Ikejima, T. Kitamura, H. Oide, Y. Takei, M. Hirose, B. U. Bradford, C. A. Rivera, H. Kono, S. Peter, S. Yamashina, A. Konno, M. Ishikawa, H. Shimizu, N. Sato, and R. Thurman.

Should indirect calorimetry be used as part of nutritional assessment?

The use of indirect calorimetry in the design of nutritional support regimens is poorly appreciated by clinicians, who fail to recognize the importance of providing a sufficient volume of enteral feeding to critically ill patients. In contrast to the overfeeding that routinely occurred in the past with the provision of total parenteral nutrition, patients placed on the enteral route of support tend to be underfed because of problems with intolerance and frequent cessation. Clearly identifying and coming as close as possible to the caloric goal may be required to achieve the therapeutic endpoints of enteral tube feeding (which include maintenance of gut integrity, attenuation of the stress response, prophylaxis against stress-induced gastropathy, and stimulation of immune function). Indirect calorimetry is a convenient, accessible, and highly accurate instrument for the measurement of caloric requirements and is a valuable tool for the optimization of nutritional support in the intensive care unit.

High-energy diets, fatty acids and endothelial cell function: implications for atherosclerosis.

Diets high in fat and/or calories can lead to hypertriglyceridemia and postprandial lipemia and thus are considered a risk factor for the development of atherosclerosis. Plasma chylomicron levels are elevated in humans after consuming a high-fat meal, and hepatic synthesis of VLDL is increased when caloric intake is in excess of body needs. High lipoprotein lipase activity and subsequent hydrolysis of triglyceride-rich lipoproteins may be an important source of elevated concentrations of fatty acid anions in the proximity to the endothelium and hence a major risk factor for atherosclerosis. We have shown that selected fatty acids, as well as lipoprotein lipase-derived remnants of lipoproteins isolated from hypertriglyceridemic subjects, can activate vascular endothelial cells and disrupt endothelial integrity. Our studies suggest that omega-6 fatty acids, and especially linoleic acid, cause endothelial cell dysfunction most markedly as well as can potentiate TNF-mediated endothelial cell injury. We propose that high-energy diets, and especially diets rich in linoleic acid, are atherogenic by contributing to an imbalance in cellular oxidative stress/antioxidant status of the endothelium, which can lead to activation of oxidative stress-responsive transcription factors, inflammatory cytokine production and the expression of adhesion molecules. Our data also suggest that nutrients, which have antioxidant and/or membrane stabilizing properties, can protect endothelial cells. These findings contribute to the understanding of the interactive role of high fat/calorie diets and subsequent hypertriglyceridemia with inflammatory components and nutrients that exhibit antiatherogenic properties in the development of atherosclerosis. Moreover, results from our research further support the concept that high-fat/calorie diets and associated postprandial hypertriglyceridemia are significant risk factors for atherosclerosis.

Biospheric primary production during an ENSO transition.

The Sea-viewing Wide Field-of-view Sensor (SeaWiFS) provides global monthly measurements of both oceanic phytoplankton chlorophyll biomass and light harvesting by land plants. These measurements allowed the comparison of simultaneous ocean and land net primary production (NPP) responses to a major El Niño to La Niña transition. Between September 1997 and August 2000, biospheric NPP varied by 6 petagrams of carbon per year (from 111 to 117 petagrams of carbon per year). Increases in ocean NPP were pronounced in tropical regions where El Niño-Southern Oscillation (ENSO) impacts on upwelling and nutrient availability were greatest. Globally, land NPP did not exhibit a clear ENSO response, although regional changes were substantial.

Chronic alcohol exposure of rats exacerbates apoptosis in hepatocytes and sinusoidal endothelial cells.

Background/aims: The liver apoptotic response to chronic alcohol consumption remains poorly characterized. The purpose of this study was to determine in rats the effects of chronic alcohol consumption on the relative magnitude of apoptosis in two major targets of alcohol-induced liver injury: the hepatocyte (Hep) and sinusoidal endothelial cell (SEC). Methods: Rats were fed a liquid diet containing either alcohol or isocaloric amounts of maltose-dextrin for 14 weeks. Hep and SEC were isolated by liver perfusion with collagenase followed by centrifugal elutriation. The state of the liver was assessed on the basis of light microscopic appearance, plasma liver enzymes (alanine and aspartate:2-oxoglutarate amino transferases), and the content of malondialdehyde in Hep. Apoptosis was assessed on the basis of DNA fragmentation in the whole organ (TUNEL), and caspase-3 and -8 activity in isolated cells. A mechanistic approach was also undertaken by measuring mRNA expression and the amount of protein for Fas/CD95, Fas ligand, caspase-3, Bax, Bcl-X(L), and Bcl-2 in the isolated Hep and SEC. Results: The livers of alcohol-fed rats displayed prominent steatosis. Oxidative stress was also present as reflected by an increase in the malondialdehyde content of Hep. Alcohol consumption increased apoptosis in the whole liver assessed on the basis of TUNEL procedure and in Hep and SEC as reflected by significant increase in caspase-3 activity. Of the multiple pro- and anti-apoptotic factors determined in this study, significant changes as assessed by both mRNA expression and the amount of proteins, were observed only in the SEC compartment. Conclusions: The data presented in this study indicate that: (1) chronic alcohol consumption in rats leads to a moderate augmentation of apoptosis in the whole liver and in two liver cell types which are targets for injury in alcoholic liver disease: Hep and SEC; (2) the mechanisms recruited/activated by these two types of liver cells to initiate and execute apoptosis in response to alcohol vary with the cell type.

Effects of Spectral Bandpass on SeaWiFS-Retrieved Near-Surface Optical Properties of the Ocean.

A simple correction method to remove the spectral bandpass effects of the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) on the derived normalized water-leaving radiances and ocean-near-surface chlorophyll concentration is developed and implemented in the SeaWiFS data-processing system. SeaWiFS has not only in-band response structures but also significant sensor out-of-band contributions. The effects of the SeaWiFS out-of-band contribution at the green bands is particularly significant for the derived normalized water-leaving radiances and therefore for the retrieved ocean-near-surface chlorophyll concentration. With the sensor spectral bandpass corrections, the low chlorophyll concentration is even lower in the clear ocean regions, whereas there are almost no changes for the oceans with a chlorophyll concentration of >0.2 mg/m(3).

Calibration of SeaWiFS. I. Direct techniques.

We present an overview of the calibration of the Sea-viewing Wide Field-of View Sensor (SeaWiFS) from its performance verification at the manufacturer's facility to the completion of its third year of on-orbit measurements. These calibration procedures have three principal parts: a prelaunch radiometric calibration that is traceable to the National Institute of Standards and Technology; the Transfer-to-Orbit Experiment, a set of measurements that determine changes in the instrument's calibration from its manufacture to the start of on-orbit operations; and measurements of the sun and the moon to determine radiometric changes on orbit. To our knowledge, SeaWiFS is the only instrument that uses routine lunar measurements to determine changes in its radiometric sensitivity. On the basis of these methods, the overall uncertainty in the SeaWiFS top-of-the-atmosphere radiances is estimated to be 4-5%. We also show the results of comparison campaigns with aircraft- and ground-based measurements, plus the results of an experiment, called the Southern Ocean Band 8 Gain Study. These results are used to check the calibration of the SeaWiFS bands. To date, they have not been used to change the instrument's prelaunch calibration coefficients. In addition to these procedures, SeaWiFS is a vicariously calibrated instrument for ocean-color measurements. In the vicarious calibration of the SeaWiFS visible bands, the calibration coefficients are modified to force agreement with surface truth measurements from the Marine Optical Buoy, which is moored off the Hawaiian Island of Lanai. This vicarious calibration is described in a companion paper.

Calibration of SeaWiFS. II. Vicarious techniques.

We present an overview of the vicarious calibration of the Sea-Viewing Wide Field-of-view Sensor (SeaWiFS). This program has three components: the calibration of the near-infrared bands so that the atmospheric correction algorithm retrieves the optical properties of maritime aerosols in the open ocean; the calibration of the visible bands against in-water measurements from the Marine Optical Buoy (MOBY); and a calibration-verification program that uses comparisons between SeaWiFS retrievals and globally distributed in situ measurements of water-leaving radiances. This paper describes the procedures as implemented for the third reprocessing of the SeaWiFS global mission data set. The uncertainty in the near-infrared vicarious gain is 0.9%. The uncertainties in the visible-band vicarious gains are 0.3%, corresponding to uncertainties in the water-leaving radiances of approximately 3%. The means of the SeaWiFS/in situ matchup ratios for water-leaving radiances are typically within 5% of unity in Case 1 waters, while chlorophyll a ratios are within 1% of unity. SeaWiFS is the first ocean-color mission to use an extensive and ongoing prelaunch and postlaunch calibration program, and the matchup results demonstrate the benefits of a comprehensive approach.

Ethanol enhances TNF-alpha-inducible NFkappaB activation and HIV-1-LTR transcription in CD4+ Jurkat T lymphocytes.

During the latent phase of human immunodeficiency virus type 1 (HIV-1) infection, CD4+ T cells carrying replication-competent proviral HIV-1 DNA play an important role in persistence of the virus. Several cofactors can induce and or amplify HIV-1 replication and negatively affect disease progression and pathogenesis. Ethanol consumption is an important risk factor for HIV-1 infection, and it has been implicated in increased HIV-1 replication and progression of infection. Because tumor necrosis factor-alpha (TNF-alpha) is an important modulator of HIV-1 replication, in the present study we examined the possible effects of ethanol on TNF-alpha-inducible signaling associated with HIV-1 replication in human CD4+ T cells (Jurkat E6-1). We demonstrate that clinically relevant ethanol concentrations significantly potentiate TNF-alpha-inducible NFkappaB. Although ethanol effectively collaborated with TNF-alpha, by itself it did not have a direct effect on NFkappaB activation. The ethanol-dependent potentiation of TNF-alpha-inducible NFkappaB nuclear translocation was observed to involve the enhanced degradation of IkappaBalpha. Additionally, the ethanol-mediated potentiation of TNF-alpha-inducible NFkappaB activation was abrogated by the known antioxidant pyrrolidinedithiocarbamate, suggesting an important mechanistic role for reactive oxygen species in this process. In correspondence with its effect on NFkappaB, ethanol was also observed to significantly enhance HIV-1 long terminal repeat-dependent transcription induced by TNF-alpha. Overall, the data provide a molecular basis for the possible role of ethanol as a cofactor that can adversely affect HIV-1 infection and pathogenesis.

Apoptosis and dysregulated ceramide metabolism in a murine model of alcohol-enhanced lipopolysaccharide hepatotoxicity.

BACKGROUND: The role of apoptosis in EtOH-induced liver injury has not been investigated much. Therefore, the question whether apoptosis is a contributory factor to alcoholic liver disease remains to be answered. The purpose of this study was to characterize the liver apoptotic response in a murine model of alcohol-enhanced lipopolysaccharide (LPS) hepatotoxicity. METHODS: Mice were fed an alcohol-containing liquid diet for 49 days followed by an acute LPS challenge. The liver state was judged on the basis of histological appearance, plasma liver enzyme activity (alanine:2-oxoglutarate and aspartate:2-oxoglutarate aminotransferases, as markers of hepatocytolysis), and plasma hyaluronan levels (as a marker of the sinusoidal endothelial cell scavenging function). The liver apoptotic response was assessed by DNA fragmentation (TUNEL procedure), and caspases-3 and -8 activity. To determine if ceramide played a role in the liver apoptotic response, the activity of acidic sphingomyelinase and tissue content of ceramide were also quantified. RESULTS: Alcohol exposure induced fat accumulation and sensitized the liver to LPS injurious effects. Plasma liver enzyme activity was elevated by alcohol and this effect was potentiated by LPS. Liver apoptosis was augmented by both alcohol and LPS treatment as reflected by high frequency of positive TUNEL staining nuclei and by an increased activity of caspase-3 and -8. Acidic sphingomyelinase activity was also increased and it was associated with an elevated tissue content of ceramide. In addition, LPS also increased plasma TNF-alpha levels. These changes were accompanied by elevated plasma hyaluronan, reflecting an impaired sinusoidal endothelial cell scavenging function. CONCLUSIONS: These results provide a more complete description of the liver apoptotic response to both alcohol and LPS and may constitute the basis for further mechanistic studies on a possible role apoptosis may play in alcoholic liver injury.