Estudo do metabolismo energético hepático e da via de sinalização da grelina na obesidade induzida por dieta ocidental

A obesidade é um dos maiores problemas de saúde pública que cresce em todo o mundo, resultante de um desequilíbrio entre ingestão alimentar e gasto energético. Pode-se dizer que a obesidade é o principal fator de risco para o desenvolvimento de doenças crônicas de maior prevalência como dislipidemias, doenças cardiovasculares, diabetes do tipo 2 e esteatose hepática não alcóolica, acarretando na redução da qualidade e expectativa de vida. A Grelina é um hormônio sintetizado pelo estômago, que atua em diferentes tecidos através de um receptor específico (GHS-R1a), incluindo hipotálamo e tecidos periféricos, como o fígado. Esse hormônio está envolvido no comportamento alimentar e adiposidade, modulando o armazenamento ou utilização dos substratos energéticos no coração, músculo esquelético, adipócitos e fígado, além disso, revela-se de grande importância na manutenção do metabolismo energético hepático. Estes dados suportam a hipótese de que as vias de sinalização responsivas à grelina são um importante componente da regulação do metabolismo energético hepático e da homeostase glicêmica. O objetivo deste trabalho, foi estudar o metabolismo energético hepático e a sinalização da grelina em camundongos Swiss adultos obesos submetidos a dieta ocidental rica em gordura saturada e carboidratos simples. Avaliamos o efeito desta dieta a partir do 21 dia de idade (desmame) até o 133 dia destes animais, através de parâmetros biométricos e bioquímicos, avaliação histomorfológica, respirometria de alta resolução, conteúdo de glicogênio hepático e conteúdo de algumas proteínas envolvidas na sinalização de insulina e grelina, além do metabolismo energético hepático. Baseado em nossos resultados observamos que o consumo de dieta ocidental rica em gordura saturada e carboidrato simples durante 16 semanas causa hiperfagia, levando ao quadro de obesidade na idade adulta e prejuízo nas vias de sinalização dos hormônios insulina e grelina, que são importantes moduladores do metabolismo energético hepático, favorecendo o desenvolvimento de esteatose hepática não alcoólica.

Utilização de marcadores salivares para avaliação e controle do desempenho físico e cognitivo em atletas de futebol

A elaboração de um programa de treinamento físico depende do controle de diferentes parâmetros bioquímicos, que se relacionam com fatores como a intensidade do exercício, imunidade e com o estado redox. Além disso, estudos recentes também começaram a apontar a relevância da função executiva como componente determinante para o alcance de um alto nível de desempenho esportivo. Por outro lado, poucos estudos foram realizados em atletas até o momento utilizando estes marcadores na saliva juntamente com os testes de função cognitiva. O objetivo desse trabalho foi estudar a capacidade discriminatória das análises bioquímicas realizadas em saliva para avaliação do desempenho físico e sua relação com a função cognitiva em atletas de futebol. Trinta e dois atletas foram submetidos ao Bangsbo Sprint Test (BST) para avaliação da capacidade física e 48 horas depois ao Teste de Stroop (TSt) e Torre de Hanoi (ToH) para avaliação da função executiva. Os níveis de lactato na saliva aumentaram quando comparados aos valores Pré-BST (6,9 vezes; p<0,05). A proteína total salivar seguiu o mesmo padrão com aumento observado após o BST (+34%; p<0,05). As concentrações de imunoglobulina-A salivar (IgA-s) não mostraram diferença significativa após o BST. Os níveis de GSH e TBARs na saliva não mostraram diferença significativa, enquanto que a concentração de ácido úrico diminuiu após o BST (-26%; p<0,05). Interessantemente, a superóxido dismutase (SOD) salivar aumentou (3,6 vezes; p<0,05), enquanto que os níveis de catalase (CAT) na saliva não alteraram significativamente. Não houve correlação de nenhum dos parâmetros analisados com o desempenho no TSt, entretanto atletas localizados no percentil superior (P90) de cortisol na saliva (11,2 ng/ mL à 32,7 ng/ mL) apresentaram tempos mais longos para a resolução do ToH. A eletroforese 2D mostrou que 215 spots só apareceram no momento Pré-BST, 63 spots aumentaram e 108 diminuíram a sua expressão após o BST. Concluindo, a saliva é sensível às modificações induzidas pelo BST. A manutenção dos níveis salivares de TBARs após o BST parece ocorrer em função da diminuição dos níveis de ácido úrico, componente este que possui uma expressiva ação antioxidante. Neste sentido, o aumento de SOD pós-exercício parece agir como uma segunda linha de defesa antioxidante contra a produção de ROS induzidas pelo BST. Além disso, os resultados dos testes de função executiva indicam que níveis elevados de cortisol salivar possuem um efeito deletério no tempo de resolução da ToH, que se refere à memória de trabalho, o planejamento e solução de problemas. No entanto o TSt, que envolve a atenção seletiva e a velocidade de processamento de informações parecem não ser afetados pelos níveis de cortisol em repouso. E finalmente, a eletroforese 2D mostrou que o BST induziu a expressão diferencial de proteínas, visto que não surgiram proteínas novas após o teste, e dezenas de proteínas foram up-reguladas e down-reguladas após o BST. Estes dados sugerem que após uma análise proteômica, estas proteínas possam ser candidatas a marcadores de desempenho físico e/ou cognitivo em futuros estudos.

Suitability of sodium lactate as cryoprotectant and its effect on gel forming ability and protein denaturation of croaker fish surimi during frozen storage

The effect of sodium lactate is compared with sucrose + sorbitol + sodium tri-poly phosphate as cryoprotectant on gel forming ability & protein denaturation of croaker surimi during frozen storage at -20±2°C for 90 days was evaluated. The quality of Croaker surimi with 6% (w/v) sodium lactate was examined in terms of biochemical parameters of muscle protein, thaw drip, gel strength and calcium ATPase activity :.omparing with those of surimi added with sucrose/sorbitol & without additive as control. Both the cryoprotectants minimized the negative effects of frozen storage on physico-chemical traits of myofibrillar proteins which was evident from the biochemical and sensory parameters. The residual Ca2+ ATPase activity and gel strength of surimi with sodium lactate were higher than those of control throughout 90 days of storage. Ca2+ A TPase activity and gel strength found a high positive correlation. From the results, it was found that sodium lactate was equally effective in preservation of croaker muscle protein native structure during frozen storage as the sucrose/ sorbitol and also less sweet without any risk of maillard browning.

Effect of nitrite, ammonia, and temperature on P. monodon larvae

P. monodon larvae were studied for the effects of temperature, ammonia, and nitrite on survival. Toxicity levels of nitrite were found to vary with larval stage. Larvae could tolerate ammonia up to about 10 ppm, with the effect more clearly shown by the zoea stage. Survival and growth were not significantly affected by temperature, although moulting was enhanced at temperatures higher than 29 C. Larvae of P. monodon have lower tolerance toward nitrite and ammonia compared to postlarvae. Although high survival was obtained at low levels of nitrite and ammonia, it is still necessary to know their effects on metabolism, in order to examine possible biochemical parameters for diagnosing sublethal toxicity or stress.

The survey on determination of malathion biomarker with genotoxicity and ecophysiological reactions in the Caspian roach (Rutilus rutilus caspicus)

In the present study possibility of Malathion biomarker with Genotoxicity and Ecophysiological reactions were determined in Caspian Roach (Rutilus rutilus caspicus). At fist LC50 value of Malathion, an organophosphate insecticide was determined. Then four groups of experimental fish (containing 30 fish in each group) were exposed to different concentrations of Malathion. e. 0, 0.01, 0.05 and 0/1 ppm respectively for 23 days and effects of Malathion on Hematological (RBC, WBC, Hb and Hct) and biochemical parameters (Glucose, triglyceride, urea, total protein and Albumin), some enzymes (SGPT, SGOT and ALP), Cortisol level, plasma cations (Na+ and K+) , histological changes (gill and liver) and finally DNA destruction were examined. Sampling was done in 3rd, 13th, 23rd days during exposure and also 30 days after recovery. Data analysis was done by SPSS (Ver.13) and graphs were drawn by Excel 2007. Results showed that WBC, RBC, Hb, Hct, some biochemical parameters and K+ of Mallation treatments were decreased significantly in compare to control group (P<0.05). Changes in enzyme were many different. No significant changes were observed in Na+ and cortisol levels (except in groups treated with 0.01 Mallation) (P>0.05). LC50 value of Malathion in Caspian Roach was 6.5 ppm. Histological examinations showed that Mallation cause tissue damages and there were more damages in longer times and in higher concentrations. Apoptotic cell and comet were observed as DNA destruction and they were more in treatments with higher Mallation concentrations for longer times.

Mouse Toxicity of Anabaena flos-aquae from Lake Dianchi, China

Some species of the genera Anabaena can produce various kinds of cyanotoxins, which may pose risks to environment and human health. Anabaena has frequently been observed in eutrophic freshwater of China in recent years, but its toxicity has been reported only in a few studies. In the present study, the toxicity of an Anabaena flos-aquae strain isolated from Lake Dianchi was investigated. Acute toxicity testing was performed by mouse bioassay using crude extracts from the lyophilized cultures. The mice exposed to crude extracts showed visible symptoms of toxicity and died within 10-24 h of the injection. Serum biochemical parameters were evaluated by the use of commercial diagnostic kits. Significant alterations were found in the serum biochemical parameters: alkaline phosphatase (AKP), gamma-glutamyl transpepticlase (gamma-GT), aspartate amino transferase (AST), alanine amino transferase (ALT), AST/ALT ratio, total protein content, albumin content, albumin/globulin (A/G) ratio, blood urea nitrogen (BUN), serum creatinine (Ssr), and total antioxidative capacity (T-AOC). Histopathological observations were carried out with hematoxylin and eosin (HE) stain under light microscope. Severe lesions were seen in the livers, kidneys, and lungs of the mice injected with crude extracts. The alterations of biochemical parameters were in a dose-dependent manner, and the severities of histological lesions were in the same manner. Based on biochemical and histological studies, this research firstly shows the presence of toxin-producing Anabaena species in Lake Dianchi and the toxic effects of its crude extracts on mammals. (C) 2008 Wiley Periodicals, Inc. Environ Toxicol 24: 10-18, 2009.

Microcystin-RR-induced accumulation of reactive oxygen species and alteration of antioxidant systems in tobacco BY-2 cells

Microcystins are cyclic heptapeptide hepatoxins produced by cyanobacteria. It has been shown that microcystins have adverse effects on animals and on plants as well. Previous researches also indicated that microcystins were capable of inducing oxidative damage in animals both in vivo and in vitro. In this study, tobacco BY-2 suspension cell line was applied to examine the effects of microcystin-RR on plant cells. Cell viability and five biochemical parameters including reactive oxygen species (ROS), superoxide dismutase (SOD), catalase (CAT), glutathione peroxide (GPX) and peroxide dismutase (POD) were investigated when cells were exposed to 50 mg/L microcystin-RR. Results showed that microcystin-RR evoked decline of the cell viability to approximately 80% after treating for 144 h. ROS levels, POD and GPX activities of the treated cells were gradually increased with a time dependent manner. Changes of SOD and CAT activities were also detected in BY-2 cells. After 168 h recovery, ROS contents, POD, GPX and CAT activities returned to normal levels. These results suggest that the microcystin-RR can cause the increase of ROS contents in plant cells and these changes led to oxidant stress, at the same time, the plant cells would improve their antioxidant abilities to combat mirocystin-RR induced oxidative injury. (c) 2005 Elsevier Ltd. All rights reserved.

Growth and antioxidant system of the cyanobacterium Synechococcus elongatus in response to microcystin-RR

Microcystins, one type of the cyanobacterial toxins, show a broad range of hazardous effects on other organisms. Most of the researches on the toxic effects of microcystins have involved in animals and higher plants. Little work, however, has been done on evaluating the mechanisms of microcystin toxicity on algae. In this study, the toxicological effects of microcystin-RR (MC-RR) on the cyanobacterium Synechococcus elongatus were investigated. For this purpose, six physio-biochemical parameters (cell optical density, reactive oxygen species (ROS), malondialdehyde (MDA), glutathione (GSH), glutathione peroxidase (GSH-Px) and glutathione S-transferase (GST)) were tested in algal cells when exposed to 100 mug(-1) microcystin-RR. The results showed that the growth of Synechococcus elongatus ( expressed as optical density) was significantly inhibited compared with the control. At the same time, the treated algae exhibited a pronounced increase in production of ROS and MDA after 6 days exposure to microcystin-RR. Signi. cant changes in GSH levels and GSH-Px, GSH activities were also detected in algal cells, with higher values being observed in the toxin treated algae after 6 days exposure. GST activities in the treated algae exhibited a decline after exposure and rapid augmentation on day 3, thereafter, they kept at a high level when compared to the control group. GSH contents and GSH-Px activities were also significantly raised in the toxin-treated algae cells from day 3, but they showed a sharp decrease on day 4, which was the onward of cell proliferation. These results suggested that oxidative stress manifested by elevated ROS levels and MDA contents might be responsible for the toxicity of microcystin to Synechococcus elongatus and the algal cells could improve their antioxidant ability through the enhancement of enzymatic and non-enzymatic preventive substances.

Responses of antioxidant systems in the hepatocytes of common carp (Cyprinus carpio L.) to the toxicity of microcystin-LR

The freshwater, bloom-forming cyanobacterium (blue-green alga) Microcystis aeruginosa produces a peptide hepatotoxin, which causes the damage of animal liver. Recently, toxic Microcystis blooms frequently occur in the eutrophic Dianchi Lake (300 km(2) and located in the South-Westem of China). Microcystin-LR from Microcystis in Dianchi was isolated and purified by high performance liquid chromatography (HPLC) and its toxicity to mouse and fish liver was studied (Li et al., 2001). In this study, six biochemical parameters (reactive oxygen species, glutathione, superoxide dismutase, catalase, glutathione peroxide and glutathione S-transferase) were determined in common carp hepatocytes when the cells were exposed to 10 mug microcystin-LR per litre. The results showed that reactive oxygen species (ROS) contents increased by more than one-time compared with the control after 6 h exposure to the toxin. In contrast, glutathione (GSH) levels in the hepatocytes exposed to microcystin-LR decreased by 47% compared with the control. The activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxide (GSH-Px) increased significantly after 6 h exposure to microcystin-LR, but glutathione S-transferase (GST) activity showed no difference from the control. These results suggested that the toxicity of microcystin-LR caused the increase of ROS contents and the depletion of GSH in hepatocytes exposed to the toxin and these changes led to oxidant shock in hepatocytes. Increases of SOD, CAT and GSH-Px activities revealed that these three kinds of antioxidant enzymes might play important roles in eliminating the excessive ROS. This paper also examined the possible toxicity mechanism of microcystin-LR on the fish hepatocytes and the results were similar to those with mouse hepatocytes. (C) 2003 Elsevier Science Ltd. All rights reserved.

有机碳对混合菌群亚硝酸盐氮氧化的影响

自养硝化过程在自然界氮素循环和污水处理系统脱氮过程中起着关键作用。因此，了解有机碳对硝化的影响和硝化菌与异养菌之间的竞争对微生物生态学和污水处理系统设计都很重要。目前对氨氧化到硝酸盐氮过程的研究文献很多，但对亚硝酸盐氧化过程在异养菌的存在下如何受到有机碳影响的研究甚少。本文从生理生化指标、基因组学、蛋白组学三方面考察了在实验室条件下有机碳（乙酸钠）对硝化细菌和异养菌组成的混合菌群的硝化性能、菌群结构及代谢功能的变化的影响。 全文分为两大部分： 第一部分为乙酸钠对游离态硝化混合菌群的硝化性能和菌群结构的短期影响。混合菌株先在自养条件下进行连续培养，两个月后硝化速率达到20 mg N/(L·d)；而后离心收集菌体进行批式实验。在批式反应器中，初始亚硝氮均为126mg N/ L，乙酸钠-C 与亚硝酸盐-N 的比分别为0，0.44，0.88，4.41，8.82。结果表明：在低C/N 比（0.44 和0.88）时，亚硝酸盐去除速率比C/N=0 下高，细菌呈现一次生长；而在高C/N 比（4.41 和8.82）时，出现连续的硝化反硝化，亚硝酸盐去除率仍比对照下高，细菌呈现二次生长。不同C/N 比下微生物群落明显不同，优势菌群从自养和寡营养细菌体系（包括亚硝酸盐氧化菌，拟杆菌门,α-变形菌纲,浮霉菌门和绿色非硫细菌下的一些菌株）过渡到异养和反硝化菌体系 （γ-变形菌纲的菌株尤其是反硝化菌Pseudomonas stutzeri 和P. nitroreducens 占主导）。 第二部分为乙酸钠对硝化混合菌群生物膜的硝化性能和菌群结构的长期影响。接种富集的硝化混合菌群于装有组合式填料的三角瓶中，于摇床中自养培养；两个月后填料上形成生物膜的硝化速率达到20 mg N/ (L·d)；而后进行长期实验，每12 小时更换混合营养培养基（亚硝氮约200 mg N/ L，C/N 比同上）。结果显示：相较于C/N 比=0 时的亚硝酸盐氧化反应来说，低C/N 比出现了部分的反硝化，而高C/N 比则是几乎完全的反硝化。与对照比，C/N=0.44 时亚硝酸盐氧化速率并未受乙酸钠的影响，反而上升了，但C/N=0.88 时亚硝酸盐氧化速率有所下降。菌群结构分析表明自养对照与混合营养下微生物群落的不同；PCR-DGGE未检测出混合营养下硝化杆菌的存在，而显示异养菌尤其是反硝化菌的大量存 在。荧光定量PCR 结果表明随C/N 比上升，硝化杆菌数量从2.42 × 104 下降到1.34× 103 16S rRNA gene copies/ ng DNA，反硝化菌由0 增加至2.51 × 104 nosZgene copies/ ng DNA。SDS-PAGE 的结果表明不同C/N 比下的蛋白组较为复杂且呈现一定的差异性。 有机碳对亚硝氮氧化及微生物群落的影响很复杂，本文分别讨论了对游离态和生物膜固定态两种状态的混合菌群相应的短期和长期影响研究。研究发现，有机碳并非一定带来硝化的负影响，如果控制在适当的C/N 比范围，有机碳是有利于亚硝氮氧化的。这些发现阐明了有机碳和硝化反硝化的关系，填补了硝化微生物生态学上的空白，对污水处理系统中减少异养菌的影响并提高氮去除率有一定理论指导意义。 Nitrification plays a key role in the biological removal of nitrogen in both nature and wastewater treatment plant (WWTP). So, understanding of the effect of organic carbon on nitrification and the competition between nitrifying bacteria and heterotrophic bacteria is important for both microbial ecology and WWTP design and operation. Despite the fact that the nitrification process of ammonia to nitrate has been extensively investigated, it is not known how the process of nitrite oxidization is affected by organic carbon when heterotrophic bacteria are present. By measuring different physiological and biochemical parameters, as well as using genomic DNA and proteome analysis, we investigated the influence of organic (acetate) on nitrite oxidizing performance, community structure and metabolic function of nitrite-oxidizing and heterotrophic bacteria under laboratory conditions. The dissertation involves two parts: Part one deals with the effect of organic matter on functional performance and bacterial community shift of nitrite-oxidizing and heterotrophic bacteria under suspended state. The bacteria were prepared in a continuous-flow stirred reactor under autotrophic condition; after two months, the nitrification rate of the culture reached about 20 mg N/ (L·d); then the bacteria were harvested for the next batch experiments. The initial concentrations of nitrite were 126 ± 6 mg N/ L in all flasks, and sodium acetate (C) to nitrite (N) ratios were 0, 0.44, 0.88, 4.41, and 8.82, respectively. The results showed that at low C/N ratios (0.44 or 0.88), the nitrite removal rate was higher than that obtained under autotrophic condition and the bacteria had single growth phase, while at high C/N ratios (4.41 or 8.82), continuous aerobic nitrification and denitrification occurred besides higher nitrite removal rates, and the bacteria had double growth phases. The community structure of total bacteria strikingly varied with the different C/N ratios; the dominant populations shifted from autotrophic and oligotrophic bacteria (NOB, and some strains of Bacteroidetes, Alphaproteobacteria, Actinobacteria, and green nonsulfur bacteria) to heterotrophic and denitrifying bacteria (strains of Gammaproteobacteria, especially Pseudomonas stutzeri and P. nitroreducens). Part two describes the influence of acetate on nitrite oxidizing performance, community structure and metabolic function of nitrite-oxidizing and heterotrophic bacteria in biofilms. Bacterial enrichments was transferred into flasks with polypropylene carriers and cultured under agitated and autotrophic condition. After two month, the biofilms grown on the carriers had a nitrification rate of about 20 mg N/ (L·h); then the biofilms were refreshed with mixotrophic medium (nitrite were 200 mg N/ L in all flasks, and C/N ratios was the same as above) every 12 h. the results show: normal nitrite oxidization reactions were performed when C/N = 0, but nitrite oxidization and partial denitrification occurred with low C/N ratios (0.44 or 0.88). At high C/N ratios (4.41 or 8.82), we mainly observed denitrification. In contrast to C/N = 0, the nitrite oxidization rate was unaffected when C/N = 0.44, but decreased with C/N = 0.88. The structure of bacterial communities varied significantly between autotrophic and mixotrophic conditions. Nitrobacter was hard to detect by PCR-DGGE while heterotrophs and especially denitrifiers were in the majority under mixotrophic conditions. Real-time PCR indicated that the Nitrobacter population decreased from 2.42 × 104 to 1.34 × 103 16S rRNA gene copies/ ng DNA, while the quantity of denitrifiers obviously increased from 0 to 2.51×104 nosZ gene copies/ ng DNA with an increasing C/N ratio. SDS-PAGE indicated the complexity of and a certain difference between the proteome of nitrite-oxidizing and heterotrophic bacteria at different C/N ratios. We conclude that the influence of organic matter on nitrite oxidation and the community structure of NOB and heterotrophic bacteria is complex. In this dissertation, we focused on how sodium acetate influenced the system both under suspended state and in biofilms. We observed that acetate did not necessarily have a negative impact on nitrification. Instead, an appropriate amount of acetate benefited both nitrite oxidization and denitrification. These findings provide a greater understanding about the relationship between organics and nitrification; they fill the gaps in the field of microbial ecology of nitrifying bacteria; they also provide insight into how to minimize the negative impact of heterotrophic bacteria and maximize the benefit of nitrogen removal in biological treatment systems.

NMR-based metabonomic study on the subacute toxicity of aristolochic acid in rats

The subacute toxicity of aristolochic acid (AA) was investigated by H-1 NMR spectroscopic and pattern recognition (PR)-based metabonomic methods. Model toxins were used to enable comparisons of the urinary profiles from rats treated with known toxicants and AA at various time intervals. Urinary H-1 NMR spectra were data-processed and analyzed by pattern recognition method. The result of visual comparison of the spectra showed that AA caused a renal proximal tubular and papillary lesion and a slight hepatic impair. Pattern recognition analysis indicated that the renal proximal tubule lesion was the main damage induced by AA, and the renal toxicity induced by AA was a progressive course with the accumulation of dosage by monitoring the toxicological processes from onset, development and part-recovery. These results were also supported by the conventional clinical biochemical parameters.

Blood and urinary abnormalities induced during and after 24-hour continuous running: A case report

In this reported clinical case, a healthy and well-trained male subject [aged 37 years, maximal oxygen uptake (V[Combining Dot Above]O2max) 64 mL·kg·min] ran for 23 hours and 35 minutes covering 160 km (6.7 km/h average running speed). The analysis of hematological and biochemical parameters 3 days before the event, just after termination of exercise, and after 24 and 48 hours of recovery revealed important changes on muscle and liver function, and hemolysis. The analysis of urine sediments showed an increment of red and white blood cells filtrations, compatible with transient nephritis. After 48 hours, most of these alterations were recovered. Physicians and health professionals who monitor such athletic events should be aware that these athletes could exhibit transient symptoms compatible with severe pathologies and diseases, although the genesis of these blood and urinary abnormalities are attributable to transient physiological adaptations rather to pathological status.

Safety profile of L-arginine infusion in moderately severe falciparum malaria.

BACKGROUND: L-arginine infusion improves endothelial function in malaria but its safety profile has not been described in detail. We assessed clinical symptoms, hemodynamic status and biochemical parameters before and after a single L-arginine infusion in adults with moderately severe malaria. METHODOLOGY AND FINDINGS: In an ascending dose study, adjunctive intravenous L-arginine hydrochloride was infused over 30 minutes in doses of 3 g, 6 g and 12 g to three separate groups of 10 adults hospitalized with moderately severe Plasmodium falciparum malaria in addition to standard quinine therapy. Symptoms, vital signs and selected biochemical measurements were assessed before, during, and for 24 hours after infusion. No new or worsening symptoms developed apart from mild discomfort at the intravenous cannula site in two patients. There was a dose-response relationship between increasing mg/kg dose and the maximum decrease in systolic (rho = 0.463; Spearman's, p = 0.02) and diastolic blood pressure (r = 0.42; Pearson's, p = 0.02), and with the maximum increment in blood potassium (r = 0.70, p<0.001) and maximum decrement in bicarbonate concentrations (r = 0.53, p = 0.003) and pH (r = 0.48, p = 0.007). At the highest dose (12 g), changes in blood pressure and electrolytes were not clinically significant, with a mean maximum decrease in mean arterial blood pressure of 6 mmHg (range: 0-11; p<0.001), mean maximal increase in potassium of 0.5 mmol/L (range 0.2-0.7 mmol/L; p<0.001), and mean maximal decrease in bicarbonate of 3 mEq/L (range 1-7; p<0.01) without a significant change in pH. There was no significant dose-response relationship with blood phosphate, lactate, anion gap and glucose concentrations. All patients had an uncomplicated clinical recovery. CONCLUSIONS/SIGNIFICANCE: Infusion of up to 12 g of intravenous L-arginine hydrochloride over 30 minutes is well tolerated in adults with moderately severe malaria, with no clinically important changes in hemodynamic or biochemical status. Trials of adjunctive L-arginine can be extended to phase 2 studies in severe malaria. TRIAL REGISTRATION: ClinicalTrials.gov NCT00147368.

Prevention of retinal capillary basement membrane thickening in diabetic dogs by a non-steroidal anti-inflammatory drug

AIMS/HYPOTHESIS: To investigate the effect of treatment with the non-steroidal anti-inflammatory drug Sulindac on the early vascular pathology of diabetic retinopathy in the dog, and it's effect on recognised biochemical indices of hyperglycaemia-related pathophysiology. METHODS: Experimental diabetes (streptozotocin/alloxan) was induced in 22 male beagle dogs and 12 of the animals were assigned at random to receive oral Sulindac (10 mg/kg daily). Age- and sex-matched control animals were maintained as non-diabetic controls. After 4 years, several morphological parameters were quantified in the retinal microvasculature of each animal group using an established stereological method. Also, the following diabetes-associated biochemical parameters were analysed: accumulation of advanced glycation end products (AGEs), red blood cell polyol levels and antioxidant status. RESULTS: Diabetes increased red blood cell sorbitol levels when compared to non-diabetic controls (p<or =0.05), however, there was no difference in sorbitol levels between the untreated and the treated diabetic animals. No significant differences were found in red blood cell myoinositol levels between the three groups of animals. Pentosidine and other AGEs were increased two- to three-fold in the diabetic animals (p<or =0.001) although treatment with Sulindac did not affect their accumulation in diabetic skin collagen or alter diabetes-induced rises in plasma malondialdehyde. Retinal capillary basement membrane volume was significantly increased in the untreated diabetic dogs compared to non-diabetic controls or Sulindac-treated diabetic animals (p<or =0.0001). CONCLUSION/INTERPRETATION: This study has confirmed the beneficial effect of a non-steroidal anti-inflammatory drug on the early vascular pathology of diabetic retinopathy. However the treatment benefit was not dependent on inhibition of polyol pathway activity, advanced glycation, or oxidative stress.

PET-CT as a predictor of outcome in resectable colorectal liver metastases

Introduction
PET-computed tomography (PET-CT) is a useful staging imaging modality in colorectal liver metastases (CRLM). This study aimed to determine whether PET-CT parameters, standardized uptake value (SUV) and reconstructed tumour volume (RTV), are predictors of prognosis and survival.

Methods
A study of all resectable CRLM patients in the regional HPB unit from 2007–2009 was performed. Preoperative PET-CT scans were retrospectively reviewed; SUV, diameter and RTV for each lesion was recorded. Correlation analysis was performed with other pathological and biochemical parameters, by Pearson’s correlation analysis. Survival analysis was performed using Cox regression hazard model. A P value of less than 0.05 was considered statistically significant.

Results
A total of 79 patients were included. SUV moderately correlated with tumour diameter, both PET-CT (r=0.4927; P<0.0001) and histology (r=0.4513; P=0.0003); RTV (r=0.4489; P<0.001), preoperative carcinoembryonic antigen (CEA) (r=0.4977; P=0.0001), and postoperative CEA (r=0.3727; P=0.004). Multivariate analysis found that an independent predictor of SUVmax was preoperative CEA (P=0.03). RTV strongly correlated with preoperative CEA (r=0.9389; P<0.0001). SUV and RTV had a negative effect on survival.

Conclusion
PET-CT, in the setting of CRLM, may have a prognostic role in assessing survival. Although no definite conclusions can be drawn regarding the prognostic role of SUV and RTV, it acts to reinforce the need for further prospective studies to validate these findings.