Achievement of Target Gain Larger than Unity in an Inertial Fusion Experiment

On December 5, 2022, an indirect drive fusion implosion on the National Ignition Facility (NIF) achieved a target gain G_{target} of 1.5. This is the first laboratory demonstration of exceeding "scientific breakeven" (or G_{target}>1) where 2.05 MJ of 351 nm laser light produced 3.1 MJ of total fusion yield, a result which significantly exceeds the Lawson criterion for fusion ignition as reported in a previous NIF implosion [H. Abu-Shawareb et al. (Indirect Drive ICF Collaboration), Phys. Rev. Lett. 129, 075001 (2022)PRLTAO0031-900710.1103/PhysRevLett.129.075001]. This achievement is the culmination of more than five decades of research and gives proof that laboratory fusion, based on fundamental physics principles, is possible. This Letter reports on the target, laser, design, and experimental advancements that led to this result.

Lawson Criterion for Ignition Exceeded in an Inertial Fusion Experiment

For more than half a century, researchers around the world have been engaged in attempts to achieve fusion ignition as a proof of principle of various fusion concepts. Following the Lawson criterion, an ignited plasma is one where the fusion heating power is high enough to overcome all the physical processes that cool the fusion plasma, creating a positive thermodynamic feedback loop with rapidly increasing temperature. In inertially confined fusion, ignition is a state where the fusion plasma can begin "burn propagation" into surrounding cold fuel, enabling the possibility of high energy gain. While "scientific breakeven" (i.e., unity target gain) has not yet been achieved (here target gain is 0.72, 1.37 MJ of fusion for 1.92 MJ of laser energy), this Letter reports the first controlled fusion experiment, using laser indirect drive, on the National Ignition Facility to produce capsule gain (here 5.8) and reach ignition by nine different formulations of the Lawson criterion.

Effects of Sodium Thiosulfate During Resuscitation From Trauma-and-Hemorrhage in Cystathionine-γ-Lyase Knockout Mice With Diabetes Type 1

Background

Sodium thiosulfate (STS) is a recognized drug with antioxidant and H2S releasing properties. We recently showed that STS attenuated organ dysfunction and injury during resuscitation from trauma-and-hemorrhage in CSE-ko mice, confirming its previously described organ-protective and anti-inflammatory properties. The role of H2S in diabetes mellitus type 1 (DMT1) is controversial: genetic DMT1 impairs H2S biosynthesis, which has been referred to contribute to endothelial dysfunction and cardiomyopathy. In contrast, development and severity of hyperglycemia in streptozotocin(STZ)-induced DMT1 was attenuated in CSE-ko mice. Therefore, we tested the hypothesis whether STS would also exert organ-protective effects in CSE-ko mice with STZ-induced DMT1, similar to our findings in animals without underlying co-morbidity.

Methods

Under short-term anesthesia with sevoflurane and analgesia with buprenorphine CSE-ko mice underwent DMT1-induction by single STZ injection (100 μg⋅g-1). Seven days later, animals underwent blast wave-induced blunt chest trauma and surgical instrumentation followed by 1 h of hemorrhagic shock (MAP 35 ± 5 mmHg). Resuscitation comprised re-transfusion of shed blood, lung-protective mechanical ventilation, fluid resuscitation and continuous i.v. norepinephrine together with either i.v. STS (0.45 mg⋅g-1) or vehicle (n = 9 in each group). Lung mechanics, hemodynamics, gas exchange, acid-base status, stable isotope-based metabolism, and visceral organ function were assessed. Blood and organs were collected for analysis of cytokines, chemokines, and immunoblotting.

Results

Diabetes mellitus type 1 was associated with more severe circulatory shock when compared to our previous study using the same experimental design in CSE-ko mice without co-morbidity. STS did not exert any beneficial therapeutic effect. Most of the parameters measured of the inflammatory response nor the tissue expression of marker proteins of the stress response were affected either.

Conclusion

In contrast to our previous findings in CSE-ko mice without underlying co-morbidity, STS did not exert any beneficial therapeutic effect in mice with STZ-induced DMT1, possibly due to DMT1-related more severe circulatory shock. This result highlights the translational importance of both integrating standard ICU procedures and investigating underlying co-morbidity in animal models of shock research.

Effects of Sodium Thiosulfate During Resuscitation From Trauma-and-Hemorrhage in Cystathionine Gamma Lyase (CSE) Knockout Mice

BACKGROUND

Sodium thiosulfate (Na2S2O3) is a clinically established drug with antioxidant and sulphide-releasing properties. Na2S2O3 mediated neuro- and cardioprotective effects in ischemia/reperfusion models and anti-inflammatory effects in LPS-induced acute lung injury. Moreover, Na2S2O3 improved lung function during resuscitation from hemorrhagic shock in swine with pre-existing atherosclerosis, characterized by decreased expression of cystathionine γ-lyase (CSE), a major source of hydrogen sulfide (H2S) synthesis in the vasculature. Based on these findings, we investigated the effects of Na2S2O3 administration during resuscitation from trauma-and-hemorrhage in mice under conditions of whole body CSE deficit.

METHODS

After blast wave-induced blunt chest trauma and surgical instrumentation, CSE knockout (CSE-/-) mice underwent 1 h of hemorrhagic shock (MAP 35 ± 5 mm Hg). At the beginning of resuscitation comprising retransfusion, norepinephrine support and lung-protective mechanical ventilation, animals received either i.v. Na2S2O3 (0.45 mg g-1, n = 12) or vehicle (saline, n = 13). Hemodynamics, acid-base status, metabolism using stable isotopes, and visceral organ function were assessed. Blood and organs were collected for analysis of cytokines, mitochondrial respiratory capacity, and immunoblotting.

RESULTS

Na2S2O3 treatment improved arterial paO2 (P = 0.03) coinciding with higher lung tissue glucocorticoid receptor expression. Norepinephrine requirements were lower in the Na2S2O3 group (P < 0.05), which was associated with lower endogenous glucose production and higher urine output. Na2S2O3 significantly increased renal tissue IκBα and heme oxygenase-1 expression, whereas it lowered kidney IL-6 and MCP-1 levels.

CONCLUSION

Na2S2O3 exerted beneficial effects during resuscitation of murine trauma-and-hemorrhage in CSE-/- mice, confirming and extending the previously described organ-protective and anti-inflammatory properties of Na2S2O3. The findings make Na2S2O3 a potentially promising therapeutic option in the context of impaired CSE activity and/or reduced endogenous H2S availability.

Cross-feeding between Bifidobacterium infantis and Anaerostipes caccae on lactose and human milk oligosaccharides

The establishment of the gut microbiota immediately after birth is a dynamic process that may impact lifelong health. At this important developmental stage in early life, human milk oligosaccharides (HMOs) serve as specific substrates to shape the gut microbiota of the nursling. The well-orchestrated transition is important as an aberrant microbial composition and bacterial-derived metabolites are associated with colicky symptoms and atopic diseases in infants. Here, we study the trophic interactions between an HMO-degrader, Bifidobacterium infantis and the butyrogenic Anaerostipes caccae using carbohydrate substrates that are relevant in the early life period including lactose and total human milk carbohydrates. Mono- and co-cultures of these bacterial species were grown at pH 6.5 in anaerobic bioreactors supplemented with lactose or total human milk carbohydrates. A. caccae was not able to grow on these substrates except when grown in co-culture with B. infantis, leading to growth and concomitant butyrate production. Two levels of cross-feeding were observed, in which A. caccae utilised the liberated monosaccharides as well as lactate and acetate produced by B. infantis. This microbial cross-feeding points towards the key ecological role of bifidobacteria in providing substrates for other important species that will colonise the infant gut. The progressive shift of the gut microbiota composition that contributes to the gradual production of butyrate could be important for host-microbial crosstalk and gut maturation.

Short chain fatty acids in human gut and metabolic health

Evidence is accumulating that short chain fatty acids (SCFA) play an important role in the maintenance of gut and metabolic health. The SCFA acetate, propionate and butyrate are produced from the microbial fermentation of indigestible carbohydrates and appear to be key mediators of the beneficial effects elicited by the gut microbiome. Microbial SCFA production is essential for gut integrity by regulating the luminal pH, mucus production, providing fuel for epithelial cells and effects on mucosal immune function. SCFA also directly modulate host metabolic health through a range of tissue-specific mechanisms related to appetite regulation, energy expenditure, glucose homeostasis and immunomodulation. Therefore, an increased microbial SCFA production can be considered as a health benefit, but data are mainly based on animal studies, whereas well-controlled human studies are limited. In this review an expert group by ILSI Europe’s Prebiotics Task Force discussed the current scientific knowledge on SCFA to consider the relationship between SCFA and gut and metabolic health with a particular focus on human evidence. Overall, the available mechanistic data and limited human data on the metabolic consequences of elevated gut-derived SCFA production strongly suggest that increasing SCFA production could be a valuable strategy in the preventing gastro-intestinal dysfunction, obesity and type 2 diabetes mellitus. Nevertheless, there is an urgent need for well controlled longer term human SCFA intervention studies, including measurement of SCFA fluxes and kinetics, the heterogeneity in response based on metabolic phenotype, the type of dietary fibre and fermentation site in fibre intervention studies and the control for factors that could shape the microbiome like diet, physical activity and use of medication.

Human milk fatty acid profile across lactational stages after term and preterm delivery: A pooled data analysis

BACKGROUND

Lipids in human milk (HM) provide the majority of energy for developing infants, as well as crucial essential fatty acids (FA). The FA composition of HM is highly variable and influenced by multiple factors. We sought to increase understanding of the variation in HMFA profiles and their development over the course of lactation, and after term and preterm delivery, using a pooled data analysis.

OBJECTIVE

To review the literature and perform a pooled data analysis to qualitatively describe an extensive FA profile (36 FAs) in term and preterm colostrum, transitional - and mature milk up to 60 days postpartum.

DESIGN

A Medline search was conducted for HMFA profile data following term or preterm delivery. The search was confined to English language papers published between January 1980 and August 2018. Studies reporting original data, extensive FA profiles in HM from healthy mothers were included. Weighted least squares (WLS) means were calculated from the pooled data using random or fixed effect models.

RESULTS

Our pooled data analysis included data from 55 studies worldwide, for a total of 4374 term milk samples and 1017 preterm milk samples, providing WLS means for 36 FAs. Patterns in both term and preterm milk were apparent throughout lactation for some FAs: The most abundant FAs (palmitic, linoleic and oleic acid) remained stable over time, whereas several long-chain polyunsaturated FAs (including ARA and DHA) seemed to decrease and short- and medium-chain FAs increased over time.

CONCLUSIONS

High heterogeneity between individual studies was observed for the reported levels of some FAs, whereas other FAs were remarkably consistent between studies. Our pooled data suggests that specific FA categories fluctuate according to distinct patterns over the course of lactation; many of these patterns are comparable between term and preterm milk.

The Mitochondria-Targeted H2S-Donor AP39 in a Murine Model of Combined Hemorrhagic Shock and Blunt Chest Trauma

Hemorrhagic shock (HS) accounts for 30% to 40% of trauma-induced mortality, which is due to multi-organ-failure subsequent to systemic hyper-inflammation, triggered by hypoxemia and tissue ischemia. The slow-releasing, mitochondria-targeted H2S donor AP39 exerted beneficial effects in several models of ischemia-reperfusion injury and acute inflammation. Therefore, we tested the effects of AP39-treatment in a murine model of combined blunt chest trauma (TxT) and HS with subsequent resuscitation.

METHODS

After blast wave-induced TxT or sham procedure, anesthetized and instrumented mice underwent 1 h of hemorrhage followed by 4 h of resuscitation comprising an i.v. bolus injection of 100 or 10 nmol kg AP39 or vehicle, retransfusion of shed blood, fluid resuscitation, and norepinephrine. Lung mechanics and gas exchange were assessed together with hemodynamics, metabolism, and acid-base status. Blood and tissue samples were analyzed for cytokine and chemokine levels, western blot, immunohistochemistry, mitochondrial oxygen consumption (JO2), and histological changes.

RESULTS

High dose AP39 attenuated systemic inflammation and reduced the expression of inducible nitric oxide synthase (iNOS) and IκBα expression in lung tissue. In the combined trauma group (TxT + HS), animals treated with high dose AP39 presented with the lowest mean arterial pressure and thus highest norepinephrine requirements and higher mortality. Low dose AP39 had no effects on hemodynamics, leading to unchanged norepinephrine requirements and mortality rates.

CONCLUSION

AP39 is a systemic anti-inflammatory agent. In our model of trauma with HS, there may be a narrow dosing and timing window due to its potent vasodilatory properties, which might result in or contribute to aggravation of circulatory shock-related hypotension.

Prebiotic oligosaccharides in early life alter gut microbiome development in male mice while supporting influenza vaccination responses

Beneficial modulation of the gut microbiota is an attractive therapeutic approach to improve the efficacy of vaccine-induced immunity. In this study, mice were supplemented with the prebiotic milk oligosaccharide 2'-fucosyllactose (2'FL) as well as a complex mixture of immune modulatory prebiotic short-chain galacto-oligosaccharides and long-chain fructo-oligosaccharides (scGOS/lcFOS) from different stages in early life. Adult mice were vaccinated with trivalent influenza vaccine (TIV) and both development of the gut microbiota and antibody-mediated vaccine responses were followed over time. Within the control group, female mice demonstrated a larger antibody response to TIV vaccination than male mice, which was accompanied by enhanced cytokine production by splenocytes and a higher percentage of plasma cells in skin draining lymph nodes. In addition, the prebiotic diet improved vaccine-specific antibody responses in male mice. Introduction of prebiotics into the diet modulated the gut microbiota composition and at the genus level several bacterial groups showed a significant interaction effect which potentially contributed to the immunological effects observed. This study provides insight in the effect of scGOS/lcFOS/2'FL in influenza vaccination antibody production.

Probiotic or synbiotic alters the gut microbiota and metabolism in a randomised controlled trial of weight management in overweight adults

The gut microbiota contributes to host energy metabolism, and altered gut microbiota has been associated with obesity-related metabolic disorders. We previously reported that a probiotic alone or together with a prebiotic controls body fat mass in healthy overweight or obese individuals in a randomised, double-blind, placebo controlled clinical study (ClinicalTrials.gov NCT01978691). We now aimed to investigate whether changes in the gut microbiota may be associated with the observed clinical benefits. Faecal and plasma samples were obtained from a protocol compliant subset (n=134) of participants from a larger clinical study where participants were randomised (1:1:1:1) into four groups: (1) placebo, 12 g/d microcrystalline cellulose; (2) Litesse® Ultra™ polydextrose (LU), 12 g/day; (3) Bifidobacterium animalis subsp. lactis 420™ (B420), 10¹⁰ cfu/d in 12 g microcrystalline cellulose; (4) LU+B420, 1010 cfu/d of B420 in 12 g/d LU for 6 months of intervention. The faecal microbiota composition and metabolites were assessed as exploratory outcomes at baseline, 2, 4, 6 months, and +1 month post-intervention and correlated to obesity-related clinical outcomes. Lactobacillus and Akkermansia were more abundant with B420 at the end of the intervention. LU+B420 increased Akkermansia, Christensenellaceae and Methanobrevibacter, while Paraprevotella was reduced. Christensenellaceae was consistently increased in the LU and LU+B420 groups across the intervention time points, and correlated negatively to waist-hip ratio and energy intake at baseline, and waist-area body fat mass after 6 months treatment with LU+B420. Functional metagenome predictions indicated alterations in pathways related to cellular processes and metabolism. Plasma bile acids glycocholic acid, glycoursodeoxycholic acid, and taurohyodeoxycholic acid and tauroursodeoxycholic acid were reduced in LU+B420 compared to Placebo. Consumption of B420 and its combination with LU resulted in alterations of the gut microbiota and its metabolism, and may support improved gut barrier function and obesity-related markers.

Importance of maternal diet in the training of the infant's immune system during gestation and lactation

Latest forecasts predict that half of the European population will be allergic within the coming 15 years, with food allergies contributing substantially to the total burden; preventive measures are urgently needed. Unfortunately, all attempted alimentary strategies for primary prevention of allergic diseases through allergen avoidance so far have failed. This also holds true for the prevention of food allergies in breastfed infants by the common practice of excluding certain foods with allergenic potential from the maternal diet. As a preventive measure, therefore, exclusion diets should be discouraged. They can exhaust nursing mothers and negatively impact both their nutritional status as well as their motivation to breastfeed. A prolonged exclusion diet may be indicated solely in cases of doctor-diagnosed food allergy following rigid medical tests (e.g. double-blind placebo-controlled food challenges). Indicated cases usually involve exclusion of only a few food items. Continued breastfeeding is generally important for many aspects of the infant's health, including the training of the infant's immune responses to foreign compounds and avoidance of overshooting inflammatory responses. Recent studies suggest that the presence of maternal dietary proteins in amniotic fluid, cord blood, and human milk might support the induction of tolerance towards solid foods in infants. These are exactly the same species of proteins or remnants thereof that, in comparatively few cases, trigger allergic responses. However, the insight that the proteins of maternal dietary origin in human milk are more likely to be cure (or, more precise, directing prevention) than curse has still largely evaded the attention of health care professionals consulted by worried breastfeeding mothers. In this paper, we summarize recent literature on the importance of exposure to dietary proteins in the establishment of immunological tolerance and hence prevention of allergic disease. Multiple organizations have used the scientific knowledge to build (local) guidelines (e.g. AAAAI, EAACI, BSACI) that can support health care professionals to provide the best strategy to prevent the onset of allergic diseases. We thus hope to clarify existing confusion about the allergenic propensities of dietary proteins during early life, which has contributed to exaggerated fears around the diet of pregnant and breastfeeding mothers.

New approach shows no association between maternal milk fatty acid composition and childhood wheeze or asthma

BACKGROUND

Previous observational studies have implied breastmilk fatty acid composition may play a role in the development of atopic eczema or atopic sensitization in breastfed infants and toddlers. However, studies investigating associations with wheeze and asthma in later childhood are scarce and did not account for inherent correlation of compositional data. Our aim was to explore the association of maternal milk fatty acid composition with childhood wheezing phenotypes and asthma up to age 13 years using a new statistical approach.

METHODS

Breastmilk was collected 6 weeks and 6 months postdelivery in the Ulm Birth Cohort Study (n=720 and n=454, respectively). Concentrations of 28 fatty acids were measured by high-resolution capillary gas-liquid chromatography. To control for constant-sum constraint, concentration data were transformed using the centered log ratio method. Compositional biplots and correlation matrices were used to group centered log ratio transformed fatty acids. Adjusted risk ratios with parent-reported wheezing phenotypes and doctor-diagnosed asthma were computed using a modified Poisson regression.

RESULTS

We observed no straightforward evidence of associations between overall breastmilk fatty acid composition and specific wheeze phenotypes or doctor-diagnosed asthma.

CONCLUSION

Using appropriate statistical methodology, we report null associations. These findings may partly be attributable to several cohort-specific factors associated with breastfeeding and breastmilk collection. Further studies could improve on ours by analyzing samples of breastmilk and formula and by including all children for whom these are exclusively or together the major source of fatty acids in the first months of life.

Blunt Chest Trauma in Mice after Cigarette Smoke-Exposure: Effects of Mechanical Ventilation with 100% O2

Cigarette smoking (CS) aggravates post-traumatic acute lung injury and increases ventilator-induced lung injury due to more severe tissue inflammation and apoptosis. Hyper-inflammation after chest trauma is due to the physical damage, the drop in alveolar PO₂, and the consecutive hypoxemia and tissue hypoxia. Therefore, we tested the hypotheses that 1) CS exposure prior to blunt chest trauma causes more severe post-traumatic inflammation and thereby aggravates lung injury, and that 2) hyperoxia may attenuate this effect. Immediately after blast wave-induced blunt chest trauma, mice (n=32) with or without 3-4 weeks of CS exposure underwent 4 hours of pressure-controlled, thoraco-pulmonary compliance-titrated, lung-protective mechanical ventilation with air or 100 % O₂. Hemodynamics, lung mechanics, gas exchange, and acid-base status were measured together with blood and tissue cytokine and chemokine concentrations, heme oxygenase-1 (HO-1), activated caspase-3, and hypoxia-inducible factor 1-α (HIF-1α) expression, nuclear factor-κB (NF-κB) activation, nitrotyrosine formation, purinergic receptor 2X₄ (P2XR₄) and 2X₇ (P2XR₇) expression, and histological scoring. CS exposure prior to chest trauma lead to higher pulmonary compliance and lower PaO₂ and Horovitz-index, associated with increased tissue IL-18 and blood MCP-1 concentrations, a 2-4-fold higher inflammatory cell infiltration, and more pronounced alveolar membrane thickening. This effect coincided with increased activated caspase-3, nitrotyrosine, P2XR₄, and P2XR₇ expression, NF-κB activation, and reduced HIF-1α expression. Hyperoxia did not further affect lung mechanics, gas exchange, pulmonary and systemic cytokine and chemokine concentrations, or histological scoring, except for some patchy alveolar edema in CS exposed mice. However, hyperoxia attenuated tissue HIF-1α, nitrotyrosine, P2XR₇, and P2XR₄ expression, while it increased HO-1 formation in CS exposed mice. Overall, CS exposure aggravated post-traumatic inflammation, nitrosative stress and thereby organ dysfunction and injury; short-term, lung-protective, hyperoxic mechanical ventilation have no major beneficial effect despite attenuation of nitrosative stress, possibly due to compensation of by regional alveolar hypoxia and/or consecutive hypoxemia, resulting in down-regulation of HIF-1α expression.

Effects of glycemic control on glucose utilization and mitochondrial respiration during resuscitated murine septic shock

Background

This study aims to test the hypothesis whether lowering glycemia improves mitochondrial function and thereby attenuates apoptotic cell death during resuscitated murine septic shock.

Methods

Immediately and 6 h after cecal ligation and puncture (CLP), mice randomly received either vehicle or the anti-diabetic drug EMD008 (100 μg · g^-1). At 15 h post CLP, mice were anesthetized, mechanically ventilated, instrumented and rendered normo- or hyperglycemic (target glycemia 100 ± 20 and 180 ± 50 mg · dL^-1, respectively) by infusing stable, non-radioactive isotope-labeled ¹³C₆-glucose. Target hemodynamics was achieved by colloid fluid resuscitation and continuous i.v. noradrenaline, and mechanical ventilation was titrated according to blood gases and pulmonary compliance measurements. Gluconeogenesis and glucose oxidation were derived from blood and expiratory glucose and ¹³CO₂ isotope enrichments, respectively; mathematical modeling allowed analyzing isotope data for glucose uptake as a function of glycemia. Postmortem liver tissue was analyzed for HO-1, AMPK, caspase-3, and Bax (western blotting) expression as well as for mitochondrial respiratory activity (high-resolution respirometry).

Results

Hyperglycemia lowered mitochondrial respiratory capacity; EMD008 treatment was associated with increased mitochondrial respiration. Hyperglycemia decreased AMPK phosphorylation, and EMD008 attenuated both this effect as well as the expression of activated caspase-3 and Bax. During hyperglycemia EMD008 increased HO-1 expression. During hyperglycemia, maximal mitochondrial oxidative phosphorylation rate was directly related to HO-1 expression, while it was unrelated to AMPK activation. According to the mathematical modeling, EMD008 increased the slope of glucose uptake plotted as a function of glycemia.

Conclusions

During resuscitated, polymicrobial, murine septic shock, glycemic control either by reducing glucose infusion rates or EMD008 improved glucose uptake and thereby liver tissue mitochondrial respiratory activity. EMD008 effects were more pronounced during hyperglycemia and coincided with attenuated markers of apoptosis. The effects of glucose control were at least in part due to the up-regulation of HO-1 and activation of AMPK.

Electronic supplementary material

The online version of this article (doi:10.1186/2197-425X-2-19) contains supplementary material, which is available to authorized users.

Effects of the PPAR-β/δ agonist GW0742 during resuscitated porcine septic shock

Background

In un-resuscitated rodent models of septic shock, the peroxisome proliferator-activated receptor-β/δ (PPAR-β/δ) agonist GW0742 improved visceral organ function. Therefore, we tested the hypothesis whether GW0742 would attenuate kidney injury during long-term, resuscitated, porcine polymicrobial septic shock.

Methods

Six, 12, and 18 h after the induction of fecal peritonitis by inoculation of autologous feces, anesthetized, mechanically ventilated, and instrumented male pigs with pre-existing atherosclerosis resulting from familial hypercholesteremia and atherogenic diet randomly received either vehicle (dimethyl sulfoxide, n = 12) or GW0742 (n = 10). Resuscitation comprised hydroxyethyl starch and norepinephrine infusion titrated to maintain mean arterial pressure at baseline values.

Results

Despite aggressive fluid resuscitation, fecal peritonitis was associated with arterial hypotension requiring norepinephrine infusion, ultimately resulting in progressive lactic acidosis and acute kidney injury. GW0742 did not beneficially affect any parameter of systemic and regional hemodynamics, gas exchange, metabolism, or organ function. The parameters of inflammation, oxidative and nitrosative stress, and organ injury (post-mortem analysis for histomorphology and markers of apoptosis) were not influenced either. Immunohistochemistry of pre-shock kidney biopsies from a previous study in this swine strain showed markedly lower PPAR-β/δ receptor expression than in healthy animals.

Conclusions

In swine with pre-existing atherosclerosis, the PPAR-β/δ agonist GW0742 failed to attenuate septic shock-induced circulatory failure and kidney dysfunction, most likely due to reduced receptor expression coinciding with cardiovascular and metabolic co-morbidity.

Electronic supplementary material

The online version of this article (doi:10.1186/2197-425X-1-9) contains supplementary material, which is available to authorized users.

Adrenomedullin binding improves catecholamine responsiveness and kidney function in resuscitated murine septic shock

Purpose

Adrenomedullin (ADM) has been referred to as a double-edged sword during septic shock: On one hand, ADM supplementation improved organ perfusion and function, attenuated systemic inflammation, and ultimately reduced tissue apoptosis and mortality. On the other hand, ADM overproduction can cause circulatory collapse and organ failure due to impaired vasoconstrictor response and reduced myocardial contractility. Since most of these data originate from un-resuscitated shock models, we tested the hypothesis whether the newly developed anti-ADM antibody HAM1101 may improve catecholamine responsiveness and thus attenuate organ dysfunction during resuscitated murine, cecal ligation and puncture (CLP)-induced septic shock.

Methods

Immediately after CLP, mice randomly received vehicle (phosphate-buffered saline, n = 11) or HAM1101 (n = 9; 2 μg·g⁻¹). Fifteen hours after CLP, animals were anesthetized, mechanically ventilated, instrumented, and resuscitated with hydroxyethylstarch and continuous i.v. norepinephrine to achieve normotensive hemodynamics (mean arterial pressure > 50 to 60 mmHg).

Results

HAM1101 pretreatment reduced the norepinephrine infusion rates required to achieve hemodynamic targets, increased urine flow, improved creatinine clearance, and lowered neutrophil gelatinase-associated lipocalin blood levels, which coincided with reduced expression of the inducible nitric oxide synthase and formation of peroxynitrite (nitrotyrosine immunostaining) in the kidney and aorta, ultimately resulting in attenuated systemic inflammation and tissue apoptosis.

Conclusions

During resuscitated murine septic shock, early ADM binding with HAM1101 improved catecholamine responsiveness, blunted the shock-related impairment of energy metabolism, reduced nitrosative stress, and attenuated systemic inflammatory response, which was ultimately associated with reduced kidney dysfunction and organ injury.

Electronic supplementary material

The online version of this article (doi:10.1186/2197-425X-1-2) contains supplementary material, which is available to authorized users.

Carbamylated erythropoietin-FC fusion protein and recombinant human erythropoietin during porcine kidney ischemia/reperfusion injury

PURPOSE

To test the hypothesis that a carbamylated EPO-FC fusion protein (cEPO-FC) or recombinant human erythropoietin (rhEPO) would protect against kidney ischemia/reperfusion (I/R) injury in pigs with atherosclerosis.

METHODS

Anesthetized and mechanically ventilated animals received cEPO-FC (50 μg kg(-1)), rhEPO (5,000 IU kg(-1)), or vehicle (n = 9 per group) prior to 120 min of aortic occlusion and over 4 h of reperfusion. During aortic occlusion, mean arterial pressure (MAP) was maintained at 80-120 % of baseline values by esmolol, nitroglycerin, and ATP. During reperfusion, noradrenaline was titrated to keep MAP at pre-ischemic levels. Blood creatinine and neutrophil gelatinase-associated lipocalin (NGAL) levels, creatinine clearance, fractional Na(+) excretion, and HE and PAS staining were used to assess kidney function and histological damage. Plasma interleukin-6, tumor necrosis factor-α, nitrate + nitrite and 8-isoprostane levels were measured to assess systemic inflammation, and nitrosative and oxidative stress.

RESULTS

I/R caused acute kidney injury with reduced creatinine clearance, increased fractional Na(+) excretion and NGAL levels, moderate to severe glomerular and tubular damage and apoptosis, systemic inflammation and oxidative and nitrosative stress, but there were no differences between the treatment groups. Pre-ischemia nitrate + nitrite and 8-isoprostanes levels were lower and higher, respectively, than in healthy animals of a previous study, and immune histochemistry showed higher endothelial nitric oxide synthase and lower EPO receptor expression in pre-ischemia kidney biopsies than in biopsies from healthy animals.

CONCLUSIONS

In swine with atherosclerosis, rhEPO and cEPO-FC failed to attenuate prolonged ischemia-induced kidney injury within an 8-h reperfusion period, possibly due to reduced EPO receptor expression resulting from pre-existing oxidative stress and/or reduced NO release.

Early neutral prebiotic oligosaccharide supplementation reduces the incidence of some allergic manifestations in the first 5 years of life

BACKGROUND

A mixture of neutral prebiotic oligosaccharides has been shown to reduce the incidence of atopic dermatitis (AD) and allergy associated symptoms during the first 2 years of life.

OBJECTIVE

To evaluate if this protective effect against allergy lasted beyond the intervention period until 5 y of age.

METHODS

In a prospective, double blind, placebo-controlled fashion, healthy term infants at risk of atopy were fed either a prebiotic-supplemented (0.8 g/100 ml scGOS/lcFOS) or placebo-supplemented (0.8 g/100 ml maltodextrin) hypoallergenic formula during the first 6 mo of life. Following this intervention period, follow-up continued until 5 y of life. The present study evaluated (i) the cumulative incidence of allergic manifestations during 5 y, and (ii) the prevalence of allergic and persistent allergic manifestations at 5 y. Monitored allergic manifestations were AD, recurrent wheezing, allergic rhinoconjunctivitis and urticaria.

RESULTS

Ninety-two children (50 in placebo group, 42 in intervention group) completed the 5-y follow-up. The 5-y cumulative incidences of any allergic manifestation and atopic dermatitis were significantly lower in the scGOS/lcFOS group (30.9, 19.1 %, respectively) compared to placebo group (66, 38 %, respectively) (p< 0.01 and< 0.05). Children in the scGOS/lcFOS group tended to have a lower incidence of allergic rhinoconjunctivitis, and allergic urticaria (4.8 vs 16% for both manifestations, p=0.08). There was no difference in the cumulative incidence of recurrent wheezing. With regard to the prevalences at 5 y, intervention group had significantly lower prevalence of any persistent allergic manifestation and rhinoconjunctivitis (4.8, 2.4 %, respectively) compared to placebo (26, 14 %, respectively) (p < 0.01 and =0.05). Prevalence of persistent AD tended to be lower in the intervention group (2.4 vs 12%, p= 0.09). Although intervention group had 75% reduction in the prevalence of persistent wheezing (4.8 vs 14 %), no significance was shown.

CONCLUSION

Oligosaccharide prebiotics (scGOS/lcFOS), when started early in life have a protective effect against allergic manifestations in high risk infants. The protection lasts beyond infancy until 5 y of life, for AD and allergic rhinoconjunctivitis. Long-term follow-up studies in larger populations are warranted to evaluate the potential preventive effect of this mixture on asthma.

Long-term outcome following selective serotonin reuptake inhibitor induced neonatal abstinence syndrome

OBJECTIVE

To assess the long-term neurodevelopment of children exposed in utero to selective serotonin reuptake inhibitors (SSRIs) that developed a neonatal abstinence syndrome (NAS).

STUDY DESIGN

Neurodevelopmental evaluation was performed at the age of 2 to 6 years. Children who developed NAS were compared with those who did not using univariate and logistic regression analyses.

RESULT

Thirty children with NAS and 52 without NAS participated in the study. Both groups were similar in mean cognitive ability (106.9±14.0 vs 100.5±14.6, P=0.12) and developmental scores (98.9±11.4 vs 95.7±9.9, P=0.21). However, there was a trend towards small head circumference in the NAS group (20 vs 6%, P=0.068). NAS was associated with an increased risk of social-behavior abnormalities (odds ratio (OR) 3.03, 95% confidence interval (CI) 1.07 to 8.60, P=0.04) and advanced maternal age (OR 1.12, 95% CI 1.00 to 1.25, P=0.04).

CONCLUSION

Infants who developed NAS had normal cognitive ability, but were at an increased risk for social-behavioral abnormalities. Follow-up evaluation of symptomatic neonates should be considered.

A Depth Selective Mössbauer Study of ion Implanted Stainless Steel

High austenitic stainless steel of composition Fe62Ni2OCrl8 was implanted with Eu ions and analyzed with Depth Selective Conversion Electron Mössbauer Spectroscopy (DCEMS). DCEMS gives information about the depth profile of phases, in this case about implantation induced changes in phase composition as function of depth. The samples were complementary analyzed with Rutherford Backscattering Spectrometry (RBS) to get the element profile of the implanted ions. The main experimental result is a martensitic transformed depth region that coincides with the Eu depth distribution. The potential of DCEMS for application in the field of materials modification by implantation techniques is demonstrated.

Effects of television modeling on residential energy conservation

A combination of social marketing, communications, social learning (particularly modeling), and behavior analysis may provide an effective framework for behavior change via films and television. We used this approach in developing special television programs about residential energy conservation. The programs were tailored and directed to preselected middle-class homeowners (N = 150), and delivered over a public access channel of a cable TV system. The results indicated that after one program exposure (about 20 minutes), viewers adopted simple strategies modeled in the programs which led to savings of approximately 10% on their home energy use for a substantial part of the cooling and heating season. Although the potential benefits to costs of large-scale media efforts seemed great, institutional barriers for such programs were identified. Less expensive, more local programs seem more viable.

A specific mixture of short-chain galacto-oligosaccharides and long-chain fructo-oligosaccharides induces a beneficial immunoglobulin profile in infants at high risk for allergy

BACKGROUND

It has been suggested that human breast milk oligosaccharides play a role in the development of the immune system in infants, and may consequently inhibit the onset of allergy. A specific prebiotic mixture of short-chain galacto-oligosaccharides and long-chain fructo-oligosaccharides (GOS/FOS) has been shown to reduce the incidence of atopic dermatitis (AD) at 6 months of age in infants at risk for allergy.

AIM OF THE STUDY

This study was aimed to analyze the effect of GOS/FOS on the immune response in these infants.

METHODS

In a double-blind randomized placebo-controlled study, infants received a hypoallergenic whey formula with either 8 g/l GOS/FOS in a 9 : 1 ratio (IMMUNOFORTIS) or 8 g/l maltodextrine (placebo) for 6 months. At 3 months of age, children were vaccinated with Hexavac against a.o. diphteria, tetanus, polio (DTP). At 6 months of age, plasma samples were collected from 84 infants (verum group n = 41, placebo group n = 43). Levels of total immunoglobulins (Ig) and of cow's milk protein (CMP-) and DTP-specific Ig were measured.

RESULTS

GOS/FOS supplementation led to a significant reduction in the plasma level of total IgE, IgG1, IgG2 and IgG3, whereas no effect on IgG4 was observed. CMP-specific IgG1 was significantly decreased. DTP-specific Ig levels were not affected.

CONCLUSIONS

This study shows that GOS/FOS supplementation induces a beneficial antibody profile. GOS/FOS reduces the total Ig response and modulates the immune response towards CMP, while leaving the response to vaccination intact. This suggests that oral GOS/FOS supplementation is a safe method to restrain the atopic march.

Dietary supplementation with specific oligosaccharide mixtures decreases parameters of allergic asthma in mice

Specific mixtures of prebiotic oligosaccharides showed immune modulatory effects in previous murine vaccination experiments, suggesting a shift towards T-helper 1 (Th1) immunity. These mixtures consisted of short-chain galacto-oligosaccharides (scGOS) and long-chain fructo-oligosaccharides (lcFOS) in a 9:1 ratio (Immunofortis), with or without pectin-derived acidic oligosaccharides (pAOS). To investigate whether these mixtures could suppress Th2-related responses, they were tested in an ovalbumin (OVA)-induced model for experimental allergic asthma in BALB/c mice. Supplementation with two mixtures of scGOS/lcFOS and scGOS/lcFOS/pAOS at approximately 1% (w/w% net oligosaccharides) in the diet, starting two weeks before OVA sensitization and lasting until the end of the experiment, decreased of several parameters of allergic asthma. The OVA-induced airway inflammation and hyperresponsiveness was significantly suppressed by both mixtures. Moreover, OVA-specific IgE titers were decreased by more than 25%, although this effect was not significant. The effects of the oligosaccharide mixture with pAOS appeared to be more pronounced than the effects of the scGOS/lcFOS mixture without pAOS, but a direct comparison between the mixtures was not made. Overall, the results further support the hypothesis that specific mixtures of oligosaccharides modulate the Th1/Th2 balance by enhancing Th1-related and suppressing Th2-related parameters.

Immune-Modulatory Effects and Potential Working Mechanisms of Orally Applied Nondigestible Carbohydrates

Orally applied nondigestible carbohydrates (NDC) have been associated with immune-modulating effects and other health benefits. The effects of prebiotic carbohydrates have recently received much attention, but other NDC have been reported to induce immune modulation as well. Many different effects have been shown on parameters of innate and specific immunity, mostly in animal experiments or in vitro. Data from clinical trials are limited, but promising studies have reported beneficial effects on mucosal and systemic immunity in humans. NDC are fermented to various degrees by the intestinal microbiota. Therefore, immune-modulatory properties have often been attributed to microbiota-dependent effects, especially in the case of prebiotic NDC. However, some NDC have been reported to bind to specific receptors on cells of the immune system, suggesting microbiota-independent, immune-modulatory effects play a role as well. This review aims to provide an overview of the published immune-modulatory effects in vitro and in vivo induced by NDC such as fructans, galactooligosaccharides, beta-glucans, pectins, and resistant starch. In addition, issues related to the underlying mechanisms are discussed: interaction between bacteria, their metabolites and the immune system, as well as direct effects of NDC via lectin receptors.

A mixture of prebiotic oligosaccharides reduces the incidence of atopic dermatitis during the first six months of age

BACKGROUND

Oligosaccharides may alter postnatal immune development by influencing the constitution of gastrointestinal bacterial flora.

AIMS

To investigate the effect of a prebiotic mixture of galacto- and long chain fructo-oligosaccharides on the incidence of atopic dermatitis (AD) during the first six months of life in formula fed infants at high risk of atopy.

METHODS

Prospective, double-blind, randomised, placebo controlled trial; 259 infants at risk for atopy were enrolled. A total of 102 infants in the prebiotic group and 104 infants in the placebo group completed the study. If bottle feeding was started, the infant was randomly assigned to one of two hydrolysed protein formula groups (0.8 g/100 ml prebiotics or maltodextrine as placebo). All infants were examined for clinical evidence of atopic dermatitis. In a subgroup of 98 infants, faecal flora was analysed.

RESULTS

Ten infants (9.8%; 95 CI 5.4-17.1%) in the intervention group and 24 infants (23.1%; 95 CI 16.0-32.1%) in the control group developed AD. The severity of the dermatitis was not affected by diet. Prebiotic supplements were associated with a significantly higher number of faecal bifidobacteria compared with controls but there was no significant difference in lactobacilli counts.

CONCLUSION

Results show for the first time a beneficial effect of prebiotics on the development of atopic dermatitis in a high risk population of infants. Although the mechanism of this effect requires further investigation, it appears likely that oligosaccharides modulate postnatal immune development by altering bowel flora and have a potential role in primary allergy prevention during infancy.

Acidic oligosaccharides from pectin hydrolysate as new component for infant formulae: effect on intestinal flora, stool characteristics, and pH

OBJECTIVES

To come even closer to the functional composition of human milk, acidic oligosaccharides (AOS) from pectin were added to well known neutral prebiotics (galacto-oligosaccharides (GOS) and long-chain fructo-oligosaccharides (FOS)). The effect of AOS and GOS/FOS/AOS on intestinal flora, stool characteristics as well as acceptance and tolerance was investigated.

METHODS

Human milk contains 75% to 85% neutral and 15% to 25% acidic oligosaccharides. In this prospective, randomized, double blind study, a mixture of 80% neutral oligosaccharides (from long-chain galacto- and long-chain fructo-oligosaccharides) with 20% acidic oligosaccharides derived from pectin hydrolysis was investigated. Forty-six term infants were fed a standard formula supplemented with either maltodextrin as control (n=15), or with 0.2 g acidic oligosaccharides (n=16), or with the latter plus 0.6 g neutral oligosaccharides (mixture of galacto- and fructo-oligosaccharides; n=15). Fecal flora using plating technique and pH were measured. Stool characteristics and possible side effects (crying, vomiting, and regurgitation) were recorded.

RESULTS

There was no difference in the bifidobacteria counts between the control and the group supplemented with acidic oligosaccharides alone (8.75+/-0.50 vs. 8.58+/-0.94 log colony forming units [CFU]/g stool). In infants fed the combination of acidic and neutral oligosaccharides, bifidobacteria were increased (9.61+/-0.70 log CFU/g stool; P<0.01). The same pattern was observed with lactobacilli. Stool consistency was softest in infants fed the complete oligosaccharide mixture, but also in those fed formula supplemented with acidic oligosaccharides alone, the stool consistency was significantly softer compared with the control group. Fecal pH increased in the controls, remained constant in acidic oligosaccharides alone, and decreased in the complete mixture of oligosaccharides group.

CONCLUSION

There was no difference in growth, crying, vomiting, and regurgitation patterns between the groups. In summary, acidic oligosaccharides from pectin hydrolysate are well tolerated as ingredient in infant formulae but do not affect intestinal microecology.

Prebiotics in infant formulas

BACKGROUND

The intestinal flora of breast-fed infants is an important physiologic factor in the function of the gut and in the development of the immune system. The current research is part of a group of studies performed to answer the question whether a bovine milk formula supplemented with a prebiotic mixture from galactooligosaccharides and fructooligosaccharides can stimulate an intestinal flora similar to that of breast-fed infants.

METHODS

The prebiotic effect of the oligosaccharide mixture was tested in preterm and term infants by measuring fecal flora using plating as well as fluorescent in situ hybridization techniques. The effect of the oligosaccharides on the bacterial metabolism was studied by measuring short-chain fatty acid production in vitro and the short-chain fatty acid pattern in the stools of a group of term infants.

RESULTS

The oligosaccharide mixture increases significantly the number of bifidobacteria and reduces the number of pathogens in term as well as in preterm infants when compared with a group of infants fed an unsupplemented formula. Using a concentration of 0.8 g oligosacchrides/100 mL formula, the amount of bifidobacteria is similar to that typical of breast-fed infants. In vitro, the short-chain fatty acids produced by the mixture of oligosaccharides under study were similar to those produced by the human milk oligosaccharides fraction. In clinical trials the pattern of fecal short-chain fatty acids in infants fed the oligosaccharide mixture was similar to that of breast-fed infants but was significantly different from that of a group of infants fed with an unsupplemented formula. Additionally, the fecal pH was significantly higher in the group fed an unsupplemented formula than in the groups fed either breast milk or a supplemented formula.

CONCLUSION

The data obtained indicate that the prebiotic mixture under study is able to stimulate the development of a microbial flora similar to that of breast-fed infants. Several biota, whose growth is enhanced by this prebiotic mixture, represent important factors in the postnatal development of the immune system. On this evidence it can be suggested that prebiotics may play a role as modulators of the postnatal development of the immune system.

Prebiotic concept for infant nutrition

In the neonatal period, the intestine is colonised in a stepwise process that depends on mode of delivery, environmental factors, bacterial interactions, and the host itself resulting in a colonisation with a complex heterogeneous bacterial flora. Oligosaccharides have been identified as an important prebiotic factor of human milk As long as analogues of human milk oligosaccharides are not available now and in the near future it is aimed to resemble the prebiotic effect of human milk by oligosaccharides from available sources. In the present study in preterm infants, a mixture of 90% galacto-oligosaccharides and 10% fructo-oligosaccharides has been tested. The mixture of GOS/FOS was composed to mimic the molecule size distribution of human milk oligosaccharides. Microbiological analysis of the faces was performed before and 7, 14, and 28 days after start of supplementation and stool characteristics have been recorded. Maltodextrin was used as placebo and infants fed human milk have been used as reference. After a 28 days feeding period, the number of bifidobacteria of the group fed the oligosaccharide supplemented formula was in the upper range of the reference group whereas the numbers of the group fed the formula supplemented with the placebo were in the lower range of the reference group (placebo: 7.9 +/- 0.83 and GOS/FOS mixture: 10,0 +/- 2.05 log 10 CFU/g wet stool; reference (M +/- SD): 7.14-10.7 log 10 CFU/g wet stool). Stool characteristics in the group fed the supplemented formula were close to those found in the human milk fed infants. In summary, supplementation of a preterm formula with a mixture of galacto- and fructo-oligosaccharides has a stimulating effect on the growth of bifidobacteria in the intestine and results in more frequent produced and softer stools. Thus, prebiotic mixtures such like the studied oligosaccharide mixture might help in improving intestinal tolerance to enteral feeding in preterm infants.

Effects of a new mixture of prebiotics on faecal flora and stools in term infants

A double-blind, randomized, controlled study was performed in 90 full term infants to evaluate dose-related bifidogenic effects of a new synergistic mixture of galacto-oligosaccharides (GOS) and fructo-oligosacharides (FOS). The GOS/FOS mixture showed a dose-dependent stimulatory effect on the intestinal growth of bifidobacteria. Also stool consistency and faecal pH were positively affected.

A human flora-associated rat model of the breast-fed infant gut

OBJECTIVES

Bacterial colonization of the infant gut may have important influences on the development of gastrointestinal, respiratory, and allergic disease. Early diet is a major determinant of the gut microflora. It is very difficult to carry out studies in human infants that can investigate the interaction of diet, flora, and mucosa. In this study we have developed an infant human flora-associated (IHFA) rat model to allow such investigation.

METHODS

Germ-free infant rats were infected with fecal bacteria from exclusively breast-fed infants and were maintained on a modified infant formula for 8 weeks. The fecal and cecal contents were collected and compared with feces of breast-fed infants for bacterial populations, bacterial metabolites, and enzymes and for the ability to inhibit adhesion of pathogenic bacteria to human mucosal cells.

RESULTS

The IHFA cecum and feces were dominated by lactic acid bacteria, Bifidobacterium, and lactobacilli, which were representative of the infant feces. The fecal short-chain fatty acid profile was dominated by acetic and lactic acid in a similar manner to human infant feces. Other bacterial metabolites were similar to those of the human infant. Rat intestinal samples were able to inhibit the adhesion of pathogens to mucosal cells, but to a lesser extent than the human samples.

CONCLUSIONS

This IHFA infant model of the intestinal flora of the breast-fed infant is considered valid for studying the effect of diet on bacterial colonization and metabolism.

Testing of endocrine active substances using an enhanced OECD test guideline 407: Experiences from studies on flutamide and ethinylestradiol

Groups of five male and five female Wistar rats were treated by gavage with 0, 1, 10, and 100 mg/kg body weight (b.w.) flutamide (FLU) or 0.01, 0.05, and 0.2 mg/kg b.w. of ethinylestradiol (EE2) for at least 28 days according to an enhanced Organization for Economic Cooperation and Development (OECD) test guideline (TG) 407 to investigate which of the current and/or additional parameters would detect effects on the endocrine system and to provide data on intralaboratory variability. Two identical studies were performed in parallel on each compound. Common enhancements were determination of thyroid hormones (T3, T4) and thyroid stimulating hormone (TSH), of the stage of the estric cycle to ensure necropsy of females in diestrus, of the number and morphology of epididymal sperm, and of additional organ weights (e.g., male accessory sex organs, MASO) and histopathology of additional organs (e.g., pituitary, vagina). Endocrine-mediated findings consistently observed in these studies were decreased relative weights of MASO at 100 mg/kg FLU and at 0.2 mg/kg EE2, histological changes in pituitary and testes at &gt; or = 10 mg/kg and in MASO, epididymis and adrenals at 100 mg/kg in FLU-treated males, histological changes in the mammary gland at &gt; or = 0.05 mg/kg and in testes, MASO and adrenals at 0.2 mg/kg in EE2-treated males, estrogenization of uterus and vagina (despite necropsy in diestrus) at &gt; or = 0.01 mg/kg EE2, and changes in the ovary at 0.2 mg/kg EE2. Spermatology was insensitive (EE2) or revealed changes only at the maximum tolerated dose (MTD). Determination of T3, T4, and TSH did not contribute to the detection of the endocrine effects (FLU) or provided equivocal results. Doubling the group size to 10 animals by combining the studies run in parallel did not increase the sensitivity of detection of endocrine-mediated effects above the level obtained by histopathological examination of groups of five animals. Only some of the proposed enhancements evaluated were helpful in detecting the endocrine-mediated effects of FLU and EE2. Evaluation of studies according to an enhanced TG 407 on 10 compounds with different endocrine activities will identify the most appropriate enhancements.

Mass spectrometric investigations of human milk oligosaccharides

Human milk oligosaccharides (OS) have been fractionated by gel permeation chromatography (GPC) and analyzed by mass spectrometry (MS). Matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF/MS) and electrospray ionization (ESI) ion trap/MS were used. Using a large human milk pool, the MALDI-TOF/MS analysis of high-molecular-mass GPC fractions showed that complex, multiply fucosylated and/or sialylated OS are present over a larger mass range than described previously Acidic oligosaccharides could be detected from low-retention-time GPC fractions with masses up to 4000 Da, which has not been reported before.

Detection of four human milk groups with respect to Lewis-blood-group-dependent oligosaccharides by serologic and chromatographic analysis

Oligosaccharides from human milk samples obtained from individual donors were analyzed using high-pH anion-exchange chromatography. Three patterns of neutral oligosaccharides were detected corresponding to milk groups already described. These oligosaccharide groups correspond to the Lewis blood types Le(a-b+), Le(a+b-), and Le(a-b-). A new carbohydrate pattern was detected in a milk sample from a Le(a-b-) person in which only nonfucosylated oligosaccharides and compounds bearing alpha1,3-linked fucosyl residues were found. This finding led to the hypothesis that there exist 4 different oligosaccharide milk groups that fit well to the genetic basis of the Lewis blood group system.

Supplementation of a bovine milk formula with an oligosaccharide mixture increases counts of faecal bifidobacteria in preterm infants

BACKGROUND

The establishment of a balanced intestinal microflora which may protect against infection is desirable for the preterm infant.

OBJECTIVE

To investigate the effect of a preterm formula milk supplement consisting of oligosaccharides in similar proportions to human milk on the faecal flora and stool characteristics of preterm infants.

STUDY DESIGN

To resemble the effect of human milk, an oligosaccharide mixture consisting of 90% galacto-oligosaccharides and 10% fructo-oligosaccharides was used to supplement a standard preterm formula at a concentration of 10 g/l. This supplemented formula was studied in 15 preterm infants, and the results were compared with those found in 15 infants fed a formula supplemented with maltodextrin as placebo. A group fed fortified mother's milk was investigated as a reference group (n = 12). On four days during a 28 day feeding period (1, 7, 14, and 28), the faecal flora was investigated, and stool characteristics, growth, and possible side effects were recorded.

RESULTS

During the study period, the number of bifidobacteria in the group fed the oligosaccharide supplemented formula increased to the upper range of bifidobacteria counts in the reference group. The difference between the supplemented and non-supplemented groups was highly significant (p = 0.0008). The stool characteristics were also influenced by the supplement: the stool frequency after 28 days was significantly lower in the control group than in the oligosaccharide supplemented group (p = 0.0079) and the reference group (p < 0.0001). Over the study period, the stool consistency in the control group became harder, but remained fairly stable in the other two groups. There was no effect of the different diets on the incidence of side effects (crying, regurgitation, vomiting) or on weight gain or length gain.

CONCLUSION

Supplementing preterm formula with a mixture of galacto- and fructo-oligosaccharides at a concentration of 10 g/l stimulates the growth of bifidobacteria in the intestine and results in stool characteristics similar to those found in preterm infants fed human milk. Therefore prebiotic mixtures such as the one studied may help to improve intestinal tolerance to enteral feeding in preterm infants.

Dosage-related bifidogenic effects of galacto- and fructooligosaccharides in formula-fed term infants

BACKGROUND

Human milk oligosaccharides have been shown to stimulate selectively the growth of Bifidobacteria and Lactobacilli in the intestine. In this study, the bifidogenic effect of an experimental prebiotic oligosaccharide mixture consisting of low-molecular-weight galactooligosaccharides and high-molecular-weight fructooligosaccharides was analyzed in 90 term infants.

METHODS

Two test formulas were supplemented with either 0.4 g/dL or with 0.8 g/dL oligosaccharides. In the control formula, maltodextrin was used as placebo. At study day 1 and study day 28, the fecal species, colony forming units (cfu) and pH were measured and stool characteristics, growth, and side effects were recorded.

RESULTS

At study day 1, the median number of Bifidobacteria did not differ among the groups (0.4 g/dL group, mean [interquartile range] 8.5 [1.9] cfu/g; 0.8 g/dL group, 7.7 [6.1] cfu/g; and the placebo group, 8.8 [6.1] cfu/g) (figures in square brackets are interquartile range). At the end of the 28-day feeding period, the number of Bifidobacteria was significantly increased for both groups receiving supplemented formulas (the 0.4 g/dL group, 9.3 [4.9] cfu/g; the 0.8 g/dL group, 9.7 [0.8] cfu/g) versus the placebo group (7.2 [4.9] cfu/g, P < 0.001). This effect was dose dependent (0.4 g/dL versus 0.8 g/dL, P < 0.01). The number of Lactobacilli also increased significantly in both groups fed the supplemented formulas (versus placebo, P < 0.001), but there was no statistically significant difference between the group fed formula with 0.4 g/dL oligosaccharides and the group fed formula with 0.8 g/dL oligosaccharides. The dosage of supplement significantly influenced the change in fecal pH (P < 0.05) (placebo, pH 5.5-6.1; 0.4 g/dL formula, pH 5.48-5.44; 0.8 g/dL formula, pH 5.54-5.19). Slight changes in the stool frequency resulted in a significant difference between the placebo group and the group fed the 0.8 g/dL formula at day 28 (P < 0.01). Supplementation had a significant dose-dependent influence on stool consistency (0.8 g/dL versus placebo, P < 0.0001; 0.8 g/dL versus 0.4 g/dL, P < 0.01). Supplementation had no influence on the incidence of side effects (crying, regurgitation, vomiting) or growth.

CONCLUSIONS

These data indicate that supplementation of a term infant's formula with a mixture of galacto- and fructooligosaccharides has a dose-dependent stimulating effect on the growth of Bifidobacteria and Lactobacilli in the intestine and results in softer stool with increasing dosage of supplementation.

A trimeric protein complex functions as a synaptic chaperone machine

We identify a chaperone complex composed of (1) the synaptic vesicle cysteine string protein (CSP), thought to function in neurotransmitter release, (2) the ubiquitous heat-shock protein cognate Hsc70, and (3) the SGT protein containing three tandem tetratricopeptide repeats. These three proteins interact with each other to form a stable trimeric complex that is located on the synaptic vesicle surface, and is disrupted in CSP knockout mice. The CSP/SGT/Hsc70 complex functions as an ATP-dependent chaperone that reactivates a denatured substrate. SGT overexpression in cultured neurons inhibits neurotransmitter release, suggesting that the CSP/SGT/Hsc70 complex is important for maintenance of a normal synapse. Taken together, our results identify a novel trimeric complex that functions as a synapse-specific chaperone machine.

Epiretinal membranes after extracapsular cataract surgery

PURPOSE

To determine whether uneventful extracapsular cataract extraction (ECCE) with posterior chamber intraocular lens (PC IOL) implantation induces epiretinal membranes (ERMs).

SETTING

Private practice, with statistical evaluation at a university department in Germany.

METHODS

This prospective study comprised 296 consecutive patients (332 eyes) who had uneventful ECCE with PC IOL implantation for senile cataract. Eyes were examined within 2 weeks preoperatively and 2 weeks and 6, 9, and 12 months postoperatively. The macula was examined with a 78.0 diopter Volk lens. The main outcome measure was the presence of ERM. The membranes were classified as present when cellophane macular reflex (CMR) or macular pucker (MP) was observed.

RESULTS

The median age of the patients was 78 years (range 50 to 97 years). At baseline, ERM was present in 49 of 332 eyes (14.8%), 40 (12.1%) with CMR and 9 (2.7%) with MP. Six months postoperatively, ERM was present in 84 of 332 eyes (25.3%), 72 (21.7%) with CMR and 12 (3.6%) with MP. The difference between the baseline and 6 month incidence was significant (P <.001). All new cases of ERM were of the CMR type. One year after surgery, ERM was present in 54 of 198 eyes (27.3%), 47 (23.7%) with CMR and 7 (3.5%) with MP. The ERMs rarely influenced visual acuity; however, 6 of 12 eyes (50.0%) with MP and 13 of 72 (18.1%) with CMR had metamorphopsia.

CONCLUSIONS

The prevalence of ERM increased by 71.4% during the first 6 months after uneventful ECCE with PC IOL implantation. Thereafter, the prevalence remained about the same. Newly formed ERMs were probably induced by the uneventful surgery. Although new-onset membranes usually do not preclude good visual acuity, they can cause metamorphopsia postoperatively.

The G protein-coupled receptor CL1 interacts directly with proteins of the Shank family

PDZ domains play a pivotal role in the synaptic localization of ion channels, receptors, signaling enzymes, and cell adhesion molecules. These domains mediate protein-protein interactions via the recognition of a conserved sequence motif at the extreme C terminus of their target proteins. By means of a yeast two-hybrid screen using the C terminus of the G protein-coupled alpha-latrotoxin receptor CL1 as bait, three PDZ domain proteins of the Shank family were identified. These proteins belong to a single protein family characterized by a common domain organization. The PDZ domain is highly conserved among the family members, significantly different from other known PDZ domains, and specifically binds to the C terminus of CL1. Shank1 and CL1 are expressed primarily in brain, and both proteins co-enrich in the postsynaptic density. Furthermore, Shank1 induces a clustering of CL1 in transfected cells, strongly supporting an interaction of both proteins in vivo.

Offline coupling of low-pressure anion-exchange chromatography with MALDI-MS to determine the elution order of human milk oligosaccharides

Pooled human milk oligosaccharides were separated into neutral and several acidic oligosaccharide fractions by preparative anion-exchange chromatography (AEC) using AG 1-X2. The oligosaccharides were eluted stepwise using deionized water and three different concentrations of ammonium acetate buffer, pH 6.8. The elution order of the compounds was determined directly by matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) analysis of the AEC effluent without any cleanup or concentration steps. Up to a concentration of 500 mM ammonium acetate, the masses of acidic oligosaccharides could be detected by screening the fractions in an automated mode. The combination of the improved chromatographic procedure, the applied MALDI matrices, and operating parameters is suitable for the detection of neutral oligosaccharides as well as acidic oligosaccharides. The method provides high sensitivity and mass accuracy, including for the high-molecular-weight monosialylated oligosaccharides up to 2751.5 Da. The applied ionic strength of the anion-exchange eluents enables a rapid and an unambiguous composition assignment by MALDI-MS for neutral, monosialylated, and disialylated oligosaccharides from human milk. The acidic fractions have to be desalted by electrodialysis and were finally analyzed by HPAEC-PAD to get a high-resolution "fingerprint" of structures present in each fraction. From these analyses, it can be concluded that the isomeric variety of monosialylated oligosaccharides occurring in human milk is higher than estimated before.

Magnetic phase in the near-surface region of an FeBO3 single crystal

An FeBO3 single crystal was studied from 291 K up to the Neel temperature T(N) = 348.35 K by depth selective conversion electron Mossbauer spectroscopy in ultrahigh vacuum (10(-9) mbar). A new magnetic near-surface phase was found. Its thickness D diverges on approaching T(N) and gives a critical exponent for the correlation length of nu = 0.59(4). The phase boundary between the bulk and near-surface phase could be identified.