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The 3rd central IDL Event in Spain probably gathered the largest number of activities for the 16th May commemoration in 2021. Conferences, debates, workshops, exhibitions, light shows, and photo contests, adapted to severe constraints due to the pandemic, achieved the participation of a wide and diverse audience.

Information security and authentication are important challenges facing society. Recent attacks by hackers on the databases of large commercial and financial companies have demonstrated that more research and development of advanced approaches are necessary to deny unauthorized access to critical data. Free space optical technology has been investigated by many researchers in information security, encryption, and authentication. The main motivation for using optics and photonics for information security is that optical waveforms possess many complex degrees of freedom such as amplitude, phase, polarization, large bandwidth, nonlinear transformations, quantum properties of photons, and multiplexing that can be combined in many ways to make information encryption more secure and more difficult to attack. This roadmap article presents an overview of the potential, recent advances, and challenges of optical security and encryption using free space optics. The roadmap on optical security is comprised of six categories that together include 16 short sections written by authors who have made relevant contributions in this field. The first category of this roadmap describes novel encryption approaches, including secure optical sensing which summarizes double random phase encryption applications and flaws [Yamaguchi], the digital holographic encryption in free space optical technique which describes encryption using multidimensional digital holography [Nomura], simultaneous encryption of multiple signals [Pérez-Cabré], asymmetric methods based on information truncation [Nishchal], and dynamic encryption of video sequences [Torroba]. Asymmetric and one-way cryptosystems are analyzed by Peng. The second category is on compression for encryption. In their respective contributions, Alfalou and Stern propose similar goals involving compressed data and compressive sensing encryption. The very important area of cryptanalysis is the topic of the third category with two sections: Sheridan reviews phase retrieval algorithms to perform different attacks, whereas Situ discusses nonlinear optical encryption techniques and the development of a rigorous optical information security theory. The fourth category with two contributions reports how encryption could be implemented at the nano- or micro-scale. Naruse discusses the use of nanostructures in security applications and Carnicer proposes encoding information in a tightly focused beam. In the fifth category, encryption based on ghost imaging using single-pixel detectors is also considered. In particular, the authors [Chen, Tajahuerce] emphasize the need for more specialized hardware and image processing algorithms. Finally, in the sixth category, Mosk and Javidi analyze in their corresponding papers how quantum imaging can benefit optical encryption systems. Sources that use few photons make encryption systems much more difficult to attack, providing a secure method for authentication., Centro de Investigaciones Ópticas, Consejo Nacional de Investigaciones Científicas y Técnicas

Background & aim: Immunosenescence can increase morbi-mortality. Lactic acid producing bacteria may improve immunity and reduce morbidity and mortality in the elderly. We aimed to investigate the effects of a mixture of two new probiotic strains of Lactobacillus plantarum-CECT 7315 and 7316- on systemic immunity in elderly. Methods: 50 institutionalized elderly subjects were randomized, in a double-blind fashion, to receive for 12 weeks 1) 5·10(8) cfu/day of L. plantarum CECT7315/7316 ("low probiotic dose") (n = 13), 2) 5·10(9) cfu/day of the probiotic mixture ("high probiotic dose") (n = 19), or 3) placebo (n = 15). Leukocyte subpopulations, and cytokine levels (IL-1 , IL-10, TGF-β1) were measured in venous blood at baseline, end of treatment (week 12), and end of follow-up (week 24). Infection and survival rates were recorded. Results: After treatment, high probiotic dose resulted in significant increases in the percentages of activated potentially T-suppressor (CD8+CD25+) and NK (CD56+ CD16+) cells, while low probiotic dose increased activated T-helper lymphocytes (CD4+CD25+), B lymphocytes (CD19+), and antigen presenting cells (HLA-DR+). Also, plasma TGF-β1 concentration significantly decreased after treatment with both probiotic doses. Most of these changes remained 12 weeks after probiotic discontinuation. Incidence of infections during treatment showed a significant trend to be lower in the high probiotic dose group. In addition, there was a significant trend for mortality to be greater in the placebo group vs. both probiotic groups. Conclusions: Depending on the dose, L. plantarum CECT7315/7316 have different immune-enhancing effects in elderly subjects. These effects might result in a better clinical outcome. Introducción y objetivos: La inmunosenescencia puede aumentar la morbi-mortalidad. Las bacterias productoras de ácido láctico pueden mejorar la inmunidad y disminuir la morbilidad y mortalidad en los ancianos. Nuestro objetivo fue investigar los efectos de una mezcla de dos nuevas cepas probióticas de Lactobacillus plantarum -CECT 7315 y 7316- sobre la inmunidad sistémica en ancianos. Métodos: 50 ancianos institucionalizados se aleatorizaron, en un diseño a doble-ciego, para recibir durante 12 semanas 1) 5·10(8) ufc/día de L. plantarum CECT7315/ 7316 ("dosis baja de probiótico") (n = 13), 2) 5·10(9) ufc/día de la mezcla probiótica ("dosis alta de probiótico") (n = 19), o 3) placebo (n = 15). Se determinaron las subpoblaciones leucocitarias y los niveles de citokinas (IL-1 , IL-10, TGF-β1) en sangre venosa periférica basalmente, al final del tratamiento (sem. 12) y al final del seguimiento (sem. 24). Se registró la tasa de infecciones y la mortalidad. Resultados: Tras el tratamiento, la dosis alta de probiótico indujo aumentos significativos en los porcentajes de células potencialmente T-supresoras (CD8+CD25+) y NK (CD56+CD16+) activadas, en tanto que la dosis baja aumento los linfocitos T-colaboradores activados (CD4+CD25+), los linfocitos B (CD19+), y las células presentadoras de antígeno (HLA-DR+). Asimismo, la concentración plasmática de TGF-β1 disminuyó tras el tratamiento con ambas dosis de probiótico. La mayor parte de estos cambios se mantuvieron 12 semanas después de suspender el tratamiento. La incidencia de infecciones durante el tratamiento mostró una tendencia significativa a ser menor con la dosis alta de probiótico, mientras que se observó una tendencia significativa a que la mortalidad fuera mayor el grupo placebo vs. ambos grupos tratados con probiótico. Conclusiones: Dependiendo de la dosis, L. plantarum CECT7315/7316 tiene distintos efectos inmunoestimulantes en ancianos. Dichos efectos podrían contribuir a una mejor evolución clínica.

Background & aim: Immunosenescence can increase morbi-mortality. Lactic acid producing bacteria may improve immunity and reduce morbidity and mortality in the elderly. We aimed to investigate the effects of a mixture of two new probiotic strains of Lactobacillus plantarum-CECT 7315 and 7316- on systemic immunity in elderly. Methods: 50 institutionalized elderly subjects were randomized, in a double-blind fashion, to receive for 12 weeks 1) 5·10(8) cfu/day of L. plantarum CECT7315/7316 ("low probiotic dose") (n = 13), 2) 5·10(9) cfu/day of the probiotic mixture ("high probiotic dose") (n = 19), or 3) placebo (n = 15). Leukocyte subpopulations, and cytokine levels (IL-1 , IL-10, TGF-β1) were measured in venous blood at baseline, end of treatment (week 12), and end of follow-up (week 24). Infection and survival rates were recorded. Results: After treatment, high probiotic dose resulted in significant increases in the percentages of activated potentially T-suppressor (CD8+CD25+) and NK (CD56+ CD16+) cells, while low probiotic dose increased activated T-helper lymphocytes (CD4+CD25+), B lymphocytes (CD19+), and antigen presenting cells (HLA-DR+). Also, plasma TGF-β1 concentration significantly decreased after treatment with both probiotic doses. Most of these changes remained 12 weeks after probiotic discontinuation. Incidence of infections during treatment showed a significant trend to be lower in the high probiotic dose group. In addition, there was a significant trend for mortality to be greater in the placebo group vs. both probiotic groups. Conclusions: Depending on the dose, L. plantarum CECT7315/7316 have different immune-enhancing effects in elderly subjects. These effects might result in a better clinical outcome.

The excess of genetic information in patients with Down's syndrome (DS) produces an increase in the catalytic activity of superoxide dismutase (SOD1), an antioxidant enzyme coded on chromosome 21. It has been suggested that an increase in oxidative stress in DS patients may cause adverse effects in the cell membranes through the oxidation of polyunsaturated fatty acids (PUFAs). The aim of this study was to evaluate the cellular antioxidant system by determining the catalytic activity of the SOD1, glutathione peroxidase (GPx), catalase (CAT), and glutathione reductase (GR) enzymes and the concentrations of alpha-tocopherol in red blood cells (RBCs) in a group of 72 DS patients. The profile of fatty acids in the phospholipids of RBC membranes was also evaluated. The activity of the erythrocyte antioxidant enzymes is significantly higher in the DS group than in the control group (SOD1, 635 +/- 70 U/g Hb vs 476 +/- 67 U/g Hb; CAT, 1843 +/- 250 U/g Hb vs 1482 +/- 250 U/g Hb; GPx, 23.2 +/- 5.3 U/g Hb vs 21.5 +/- 3.6 U/g Hb; and GR, 9.32 +/- 1.4 U/g Hb vs 6.9 +/- 1.3 U/g Hb, respectively). No differences were observed in RBC alpha-tocopherol concentrations between the two groups studied. Long-chain n6 PUFA (C20:3n6, C20:4n6) concentrations were increased in DS patients, suggesting enhanced delta-6-desaturase activity. The long-chain n3 PUFA (docosahexenoic acid) does not appear to be affected by increased oxidative stress, probably because of the existence of compensatory antioxidant mechanisms.

Total plasma fatty acids were measured in 101 cirrhotic inpatients (64 men, 37 women, aged 64.3 +/- 1.2 (SEM) yr; range, 34-80) who were subsequently followed for survival for a mean of 14.8 +/- 1.0 months. Data on plasma fatty acids have been published elsewhere. Individual values of these variables were categorized in a binary fashion using the 5th or the 95th percentiles of a group of 44 well-nourished healthy controls (24 men, 20 women, aged 51.3 +/- 2.1 yr; range, 32-76) as the cutoff limit. Forty-nine patients died during follow-up (2-yr cumulative probability of survival, 52%). Deficiency of palmitate, dihomo-tau-linolenate, and arachidonate (values below the 5th percentile) were univariately associated with death (long-rank test). However, after a multivariate analysis (Cox's proportional hazards regression), only the existence of plasma arachidonate deficiency was included in the final model (beta, 0.62; relative risk, 1.86; 95% CI, 1.06-3.25; p0.05). We conclude that arachidonic acid deficiency significantly increases the mortality risk in patients with advanced liver cirrhosis.

In order to identify the predictive factors of hospital mortality in cirrhotics with spontaneous bacterial peritonitis (SBP), we studied 64 patients who fulfilled the accepted diagnostic criteria. All cases were treated with cefotaxime up to 2 days after the infection was considered cured (7.7 +/- 2.9 days). Eleven patients (17%) died while in hospital, six of them before SBP was cured. After uni- and multivariate analyses, only seven routine clinical, biological, and bacteriological variables studied were independently associated with hospital mortality. These were: the presence of upper gastrointestinal bleeding at admission (beta = 2.01), the absence of abdominal pain as presenting symptom (beta = -1.29), the polymorphonuclear count (%) in the ascites (beta = 0.48), prothrombin rate (beta = -0.22), and serum Na (beta = -0.64), creatinine (beta = 0.50), and cholesterol (beta = -0.68). When the equation obtained was computed in a randomly selected sample of the patients studied, it correctly predicted the outcome in 92.3% of the cases. We conclude that short-term outcome of SBP patients depends on the existence of recent gastrointestinal bleeding, the severity of SBP, and the degree of liver and renal failure. The prognostic value of this model needs prospective validation in a new series of patients.

Serum levels of zinc, copper, and selenium, and alkaline phosphatase activity were prospectively studied in 29 patients with inflammatory bowel disease. Fifteen patients had extensive active colitis (active colitis group). Seven patients had active, and seven cases inactive small bowel or ileocecal Crohn's disease (small bowel disease group). Ninety-three healthy subjects acted as controls. Serum trace element levels were considered in relation to vitamin A and E levels, nutritional parameters, the activity of the disease, and the recent intake of steroids. The effect of total enteral nutrition on serum trace elements was studied in seven cases. Serum zinc levels were lower and serum copper levels higher in the active colitis group than in controls (p = 0.0007, and p = 0.02, respectively). More than 50% of patients with active colonic or small bowel disease showed zinc levels below the 15th percentile of the control group. Serum zinc levels correlated with plasma vitamin A in acute colitis (r = 0.67; p = 0.006), and with both serum albumin concentration (r = 0.76; p = 0.002) and disease activity score (r = -0.67, p = 0.009) in patients with small bowel disease. The copper:zinc ratio was higher in the active colitis group than in controls (p = 0.002). In spite of the increase in serum albumin levels and the decrease in disease activity, serum zinc levels remained low after total enteral nutrition. The implications of the abnormal trace element status in patients with inflammatory bowel disease are discussed.

Fatty acid (FA) profile of plasma total lipids, phospholipids (PL), cholesteryl esters (CE), and triglycerides (TG) were measured in 101 patients with advanced liver cirrhosis and in 44 age- and sex-matched healthy controls. Plasma levels of lipidic phosphorus, esterified cholesterol, and TG also were measured, and the unsaturation index (UI) was calculated for each fraction. Total plasma concentrations of saturated FA, linoleate, and polyunsaturated FA (PUFA) were lower in cirrhotics than in controls. This profile was also found in plasma levels of PL- and CE-associated FA. No detectable amounts of C20:3n9 were found in cirrhotic patients. Percent FA distribution of lipid fractions showed a lower percentage of linoleate and PUFA and a higher relative amount of saturated and monoenoic FA in cirrhotics than in controls. As a consequence, the UI of PL and CE was diminished in liver cirrhosis. Linoleate and PUFA deficiency was more marked in CE than in PL, as shown by the number of patients with values below the 5th percentile of the control group, suggesting an attempt to maintain the unsaturation of PL as the most important component of cell membranes. Hepatic failure, poor essential FA intake, and malnutrition are some of the possible etiologic factors for PUFA deficiency in cirrhosis. Their relative contribution to plasma FA abnormalities, as well as the clinical and pathophysiological consequences of PUFA deficit in cirrhotic patients, requires further investigation.

To assess the fatty acid pattern in plasma and synovial fluid (SF) in rheumatoid arthritis (RA) and to determine clinical factors related to possible abnormalities.Thirty-nine patients with RA were included. SF samples were obtained from 9 patients. Disease activity was assessed using the Ritchie Articular Index and erythrocyte sedimentation rate. Fatty acids were assayed with gas liquid chromatography.Decreased levels of eicosapentaenoic acid (p0.0001) and total n3 polyunsaturated fatty acids (p0.05) were observed in plasma and in joint fluid, respectively. An increase of the substrates of delta-5-desaturase (C20:3n6 and C20:2n6) and decrease of their products (C20:4n6 and C22:4n6) was observed in plasma total lipids and phospholipids. The long chain mono-unsaturated fatty acids (C20: 1n9, C22: 1n9, C24: ln9) were increased in the joint fluid and in plasma phospholipids. Patients with active disease showed a mild decrease of several saturated fatty acids, n3, and n6 polyunsaturated fatty acids. Minor abnormalities or no changes in fatty acid profile were found related to use of steroids, nonsteroidal antiinflammatory drugs, and gold salts, or malnutrition.The fatty acid pattern found in RA (decreased levels of n3 polyunsaturated fatty acids) may explain the beneficial effect of fish oil. Changes in n6 polyunsaturated fatty acids suggest that delta-5 desaturation is decreased and this might facilitate the antiinflammatory effect of botanical lipids in RA.

To identify those clinical and nutritional factors associated with plasma lipid unsaturation deficiency in cirrhosis.Fatty acid profiles of plasma phospholipids (PL) and cholesteryl esters (CE) were measured in 101 inpatients with advanced cirrhosis and in 44 age- and sex-matched healthy controls. Double-bond index (DBI) was calculated for each fraction and binarily categorized in each patient using the 5th percentile of the control group as the cut-off limit. The association of 12 routine clinical, biological, and nutritional variables with derangement of each DBI was multivariately assessed by means of stepwise logistic regression analysis.The DBI of PL and CE were below the 5th percentile of the control group in 60 and 68 of 101 cirrhotic patients, respectively. After multivariate analyses, the variables found to be independent predictors of impaired unsaturation were: 1) The presence of moderate/severe malnutrition (odds ratio: 1.3-8.0 (95% CI); p0.05) and serum tau-GT1 mukat/L (odds ratio: 0.2-1.0; NS) for plasma PL, and 2) the presence of moderate/severe malnutrition (odds ratio: 1.8-17.4; p0.05), serum bilirubin50 mumol/L (odds ratio 1.7-14.5; p0.05) and serum tau-GT1 mukat/L (odds ratio 0.1-1.1; NS) for CE.Malnutrition appears to be a major factor for impaired lipid unsaturation in advanced cirrhosis. Thus, the possibility of improving plasma lipid unsaturation in these patients by means of nutritional support should be further investigated.

To ascertain the role of total enteral nutrition, compared with total parenteral nutrition, as adjunct therapy to steroids in patients with severe acute ulcerative colitis, a prospective randomized trial was conducted in 42 of such patients. Inclusion criteria were the persistence of a moderate or severe attack of the disease (Truelove's index) after 48 h on full steroid treatment (prednisone 1 mg/kg/day). Patients were randomized to receive polymeric total enteral nutrition or isocaloric, isonitrogenous total parenteral nutrition as the sole nutritional support. Remission rate and need for colectomy were similar in both groups. No significant changes in anthropometric parameters were observed in either nutritional group at the end of the study. Median increase in serum albumin was 16.7% (-0.5% to +30.4%) in the enteral feeding group, and only 4.6% (-12.0% to +13.7%) in the parenteral nutrition patients (p = 0.019). Adverse effects related to artificial nutritional support were less frequent (9% vs. 35%, p = 0.046) and milder in enterally fed patients. Postoperative infections occurred more often with parenteral nutrition (p = 0.028). These results suggest that total enteral nutrition is safe and nutritionally effective in severe attacks of ulcerative colitis. It is also cheaper and associated with fewer complications than parenteral nutrition. Total enteral nutrition should be regarded as the most suitable type of nutritional support in these patients.

Twenty-five patients with abdominopelvic malignant tumors receiving irradiation were studied. The following items were assessed before, during, and at the end of the radiation period: 1) clinical symptoms, scored on the basis of their severity; 2) orocecal transit time (lactulose-H2 breath test); and 3) absorption of lactose and bile salts. Ninety-two percent of the patients showed clinical symptoms suggestive of acute radiation enteropathy, mainly diarrhea. A significant acceleration of the orocecal transit was observed during the study: 70 +/- 6.9 min vs 63.3 +/- 6.3 min vs 44.3 +/- 5.1 min (F = 5.49, p = 0.008), being faster in patients with severe diarrhea (F = 3.25, p = 0.05). Forty-four percent and 57% of the patients developed lactose and bile salt malabsorption, respectively. A decrease in the transit time was observed, independent of the absorption or malabsorption of such substances. However, the orocecal transit was faster in those lactose malabsorbers with severe diarrhea, than in those with mild diarrhea (F = 4.2, p = 0.03). The results suggest that acceleration of orocecal transit may be a major factor in the pathophysiology of radiation-induced diarrhea, whereas lactose malabsorption may contribute to the severity of the diarrhea.

The aim of the present study was to describe the spectrum of liver disease in isolated infection by the human immunodeficiency virus and in the acquired immunodeficiency syndrome as well as evaluate whether clinical and/or biological data exist to permit specific diagnosis in liver biopsy.Liver biopsy was performed in 39 patients with the human immunodeficiency virus (34 via parenteral drug addicts), 22 of whom had established acquired immunodeficiency syndrome.In 29 cases (74%) a specific histologic diagnosis was obtained with the changes most frequently found being the presence of granulomas (11 patients), mainly in patients with stablished AIDS, and chronic active hepatitis non A non B (10 patients), specially in the cases with isolated infection by the human immunodeficiency virus. Obtaining of a specific diagnosis was associated with an increase in GOT and a decrease of the CD4 lymphocytes and the CD4/CD8 quotient (p = 0.002 in all cases). The existence of established AIDS or prolonged fever was associated with the finding of hepatic granulomas (p = 0.02 and p = 0.002, respectively). The increase in GPT, the absence of stablished AIDS and the absence of prolonged fever was associated to the presence of chronic active hepatitis (p = 0.01, p = 0.002 and p = 0.0002, respectively).In patients with infection by the human immunodeficiency virus liver biopsy provides diagnostic information in a high percentage of cases. The presence of established AIDS, prolonged fever, and hypertransaminasemia may point towards possible histologic diagnosis.

Serum selenium levels were determined in 92 healthy subjects [40 men, 52 women; mean age 33.5 +/- 1.6 (s.e.m.) years, range 16-71 years] living in the province of Barcelona, Catalunya, Spain. Only well-nourished individuals with unremarkable clinical history, normal blood chemistry and haematological tests were selected. The subjects were divided into 6 age groups for each sex. Serum samples were analysed using a modification of the standard electrothermal graphite furnace atomic absorption spectrophotometry method to shorten the procedure while maintaining its accuracy. A significant correlation (y = -1.31 + 1.51 x; r = 0.9967, P less than 0.001) was observed between our method and the standard assay method. The mean serum selenium concentration was 60.39 micrograms/l, 95 per cent CI 53.35-67.45 micrograms/l. There were age- but no sex-group differences (P less than 0.001). This result is similar to that found in countries whose low selenium levels have been related to an increased risk of some disease states. Clinical and health implications of this suboptimal selenium status are discussed.

The aim of this study was to investigate the effect of total paracentesis plus albumin or dextran-70 infusion on the nutritional status in cirrhotics with tense ascites. Seventeen patients were studied. Eight patients (group I) were treated with total paracentesis and albumin infusion, and in 9 cases (group II) dextran-70 infusion was associated to total paracentesis. The nutritional status was assessed before and two days after the procedure by measuring triceps skinfold thickness, mid-arm muscle circumference and serum albumin. No changes in anthropometric parameters were observed in either group. Patients in group I showed a significant increase in serum albumin levels (from 26.6 +/- 1.4 to 28.9 +/- 1.3 g/l; p = 0.007), whereas this parameter decreased in group II (from 25.5 +/- 1.3 to 23.1 +/- 1.4 g/l; p = 0.005). However, serum albumin levels returned to initial values in both groups one month after total paracentesis. There were no differences between both groups regarding the appearance of complications and mortality rate during admission. These results suggest that total paracentesis plus either i.v. albumin or dextran-70 has no long-term effect on the protein-energy nutritional status.

Levels of vitamins A, E, C, B1, B2, B6, B12, folate and beta-carotene were assessed in plasma or whole blood in a group of 114 healthy adults. Biochemical vitamin status was classified into acceptable or suboptimal (moderate or severe). The independent association of various factors with the finding of a suboptimal vitamin status was studied by means of logistic regression analyses. Seventy seven per cent of subjects had suboptimal vitamin status for vitamin B2, 20% for vitamin A, and 84% for beta-carotene. Although few subjects had suboptimal biochemical levels for vitamin E, plasma levels of this vitamin were significantly lower in smokers than in non-smokers (p0.01). Likewise, plasma folate levels were significantly related to body mass index and the season of blood sampling (p0.05). Old age was protective (OR 0.15; 95% CI 0.03-0.67), whereas current smoking was harmful (OR 3.63; 95% CI 1.09-12.1) for riboflavin status. Age group of 25-59 years was independently associated to a low risk of suboptimal vitamin A status (OR 0.29; 95% CI 0.09-0.88). On the other hand, female sex had a negative effect on plasma vitamin A levels (OR 2.39; 95% CI 0.82-6.92) and smoking had a harmful effect on biochemical beta-carotene status (OR 2.72; 95% CI 0.82-8.99). This cross sectional study provides information about the determinants of vitamin inadequacy, and may be the basis for further pathophysiological studies.

Parenteral nutrition (PN) offers the possibility to increase or to ensure nutrient intake in patients, in whom sufficient nutrition by oral or enteral alone is insufficient or impossible. Complementary to the ESPEN guideline on enteral nutrition of liver disease (LD) patients the present guideline is intended to give evidence-based recommendations for the use of PN in LD. For this purpose three paradigm conditions of LD were chosen: alcoholic steatohepatitis (ASH), liver cirrhosis and acute liver failure. The guideline was developed by an interdisciplinary expert group in accordance with officially accepted standards and is based on all relevant publications since 1985. The guideline was presented on the ESPEN website and visitors’ criticism and suggestions were welcome and included in the final revision. PN improves nutritional state and liver function in malnourished patients with ASH. PN is safe and improves mental state in patients with cirrhosis and severe HE. Perioperative (including liver transplantation) PN is safe and reduces the rate of complications. In acute liver failure PN is a safe second-line option to adequately feed patients in whom enteral nutrition is insufficient or impossible.

Permeable vesicles containing the proto-ring anchoring ZipA protein shrink when FtsZ, the main cell division protein, polymerizes in the presence of GTP. Shrinkage, resembling the constriction of the cytoplasmic membrane, occurs at ZipA densities higher than those found in the cell and is modulated by the dynamics of the FtsZ polymer. In vivo, an excess of ZipA generates multilayered membrane inclusions within the cytoplasm and causes the loss of the membrane function as a permeability barrier. Overproduction of ZipA at levels that block septation is accompanied by the displacement of FtsZ and two additional division proteins, FtsA and FtsN, from potential septation sites to clusters that colocalize with ZipA near the membrane. The results show that elementary constriction events mediated by defined elements involved in cell division can be evidenced both in bacteria and in vesicles. Background: Before constriction ZipA anchors FtsZ to the E. coli inner membrane as part of the cell division proto-ring. Results: Dynamic FtsZ polymers shrink ZipA-containing vesicles whereas excess of ZipA invaginates the E. coli membrane destroying the permeability barrier. Conclusion: Constriction forces can be evidenced both in bacteria and in vesicles. Significance: Defined bacterial elements reproduce division functions when assembled in vitro.

Enteral nutrition has a primary therapeutic effect in active Crohn's disease. It is unknown which nutrient(s) account for this action, but a role for both the amount and type of dietary fat has been postulated. Some clinical and experimental data suggest that medium-chain triglycerides (MCT) may reduce intestinal inflammation. We aimed to assess the effect of replacing part of the dietary fat with MCT on the incidence and severity of colitis in interleukin (IL)-10(-/-) mice under specific pathogen-free conditions. Twenty-four IL-10(-/-) 4-wk-old mice were randomized to receive a control diet based on sunflower oil [(n-6) fatty acids (FA)] and an experimental isocaloric, isonitrogenous diet with 50% sunflower and 50% coconut oil (MCT diet). When the mice were 12 wk old, they were killed and the colon was examined for the presence of colitis, lymphocyte subpopulations and apoptosis, ex vivo cytokine production in supernatant of colon explants, toll-like receptor (TLR)-2 and TLR-9 mRNA, and FA profile in colonic tissue homogenates. Colitis incidence was lower in the IL-10(-/-) mice fed the MCT diet (1/12) than in the mice fed the control diet (8/12; P = 0.03). The histological damage score was also lower in the former (P < 0.0005). Feeding the MCT diet resulted in fewer total and apoptotic intraepithelial CD3+ and lamina propria CD3+CD4+ lymphocytes, as well as downregulated production of IL-6 and interferon-gamma, and reduced TLR-9 mRNA. We conclude that partial replacement of dietary (n-6) FA with MCT decreases the incidence of colitis in a model of spontaneous intestinal inflammation and provide experimental arguments for a possible primary therapeutic effect of MCT in human Crohn's disease.