A 4-wk high-fructose diet alters lipid metabolism without affecting insulin sensitivity or ectopic lipids in healthy humans

BACKGROUND: High fructose consumption is suspected to be causally linked to the epidemics of obesity and metabolic disorders. In rodents, fructose leads to insulin resistance and ectopic lipid deposition. In humans, the effects of fructose on insulin sensitivity remain debated, whereas its effect on ectopic lipids has never been investigated. OBJECTIVE: We assessed the effect of moderate fructose supplementation on insulin sensitivity (IS) and ectopic lipids in healthy male volunteers (n = 7). DESIGN: IS, intrahepatocellular lipids (IHCL), and intramyocellular lipids (IMCL) were measured before and after 1 and 4 wk of a high-fructose diet containing 1.5 g fructose . kg body wt(-1) . d(-1). Adipose tissue IS was evaluated from nonesterified fatty acid suppression, hepatic IS from suppression of hepatic glucose output (6,6-2H2-glucose), and muscle IS from the whole-body glucose disposal rate during a 2-step hyperinsulinemic euglycemic clamp. IHCL and IMCL were measured by 1H magnetic resonance spectroscopy. RESULTS: Fructose caused significant (P < 0.05) increases in fasting plasma concentrations of triacylglycerol (36%), VLDL-triacylglycerol (72%), lactate (49%), glucose (5.5%), and leptin (48%) without any significant changes in body weight, IHCL, IMCL, or IS. IHCL were negatively correlated with triacylglycerol after 4 wk of the high-fructose diet (r = -0.78, P < 0.05). CONCLUSION: Moderate fructose supplementation over 4 wk increases plasma triacylglycerol and glucose concentrations without causing ectopic lipid deposition or insulin resistance in healthy humans.

Musculoskeletal spectroscopy

Magnetic resonance spectroscopy (MRS) of skeletal muscle has been successfully applied by physiologists over several decades, particularly for studies of high-energy phosphates (by (31)P-MRS) and glycogen (by (13)C-MRS). Unfortunately, the observation of these heteronuclei requires equipment that is typically not available on clinical MR scanners, such as broadband capability and a second channel for decoupling and nuclear Overhauser enhancement (NOE). On the other hand, (1)H-MR spectra of skeletal muscle can be acquired on many routine MR systems and also provide a wealth of physiological information. In particular, studies of intramyocellular lipids (IMCL) attract physiologists and endocrinologists because IMCL levels are related to insulin resistance and thus can lead to a better understanding of major health problems in industrial countries. The combination of (1)H-, (13)C-, and (31)P-MRS gives access to the major long- and short-term energy sources of skeletal muscle. This review summarizes the technical aspects and unique MR-methodological features of the different nuclei. It reviews clinical studies that employed MRS of one or more nuclei, or combinations of MRS with other MR modalities. It also illustrates that MR spectra contain additional physiological information that is not yet used in routine clinical applications.

[Periodontitis and cardiovascular disease]

The prevalence of periodontitis and cardiovascular disease (CVD) is high. A mixed infectious biofilm etiology of periodontitis is known but not fully established in CVD. Cofactors; smoking habits, stress, ethnicity, genetics, socioeconomics and age contribute to both diseases. The objectives of this report are to summarize factors in regards to CVD and periodontitis that are clinically relevant. The hypothesis behind a relationship between the two conditions can be founded in (I) shared infections etiology, (II) shared inflammatory response, (III) epidemiological and case-control studies, and (IV) periodontal studies demonstrating improvements of CVD markers. Streptococcus species in the S. mitis group, and S. anginosus group have been identified in periodontitis and are known as pathogens in endocarditis possibly transported from the oral cavity to the heart through bacteremia during dental therapies, and tooth brushing. Other periodontal bacteria such as Porphyromonas gingivalis, Fusobacterium nucleatum and Parvimonas micra are beta-lactamase producing and may contribute to antibiotic resistance (extended spectrum beta-lactamases). Other bacteria in CVD and periodontitis include Staphylococcus aureus, and Pseudomonas aeruginosa. Chlamydia pneumoniae and P. gingivalis lipopolyysaccharide capsels share homology and induce heat-shock protein activity and a cascade of proinflammatory cytokines. Associations between periodontitis and CVD have been presented in many studies when controlling for confounders. Other studies have demonstrated that periodontal therapies increase brachial artery flow rate and reduce serum inflammatory cytokine levels. Thus, physicians caring for subjects at CVD risk should consult with dentists/periodontists. Dentists must improve their medical knowledge and also learn to consult with physicians when treating patients at CVD risk.

Cylinder wall waste heat recovery from liquid-cooled internal combustion engines utilizing thermoelectric generators

This report is a dissertation proposal that focuses on the energy balance within an internal combustion engine with a unique coolant-based waste heat recovery system. It has been predicted by the U.S. Energy Information Administration that the transportation sector in the United States will consume approximately 15 million barrels per day in liquid fuels by the year 2025. The proposed coolant-based waste heat recovery technique has the potential to reduce the yearly usage of those liquid fuels by nearly 50 million barrels by only recovering even a modest 1% of the wasted energy within the coolant system. The proposed waste heat recovery technique implements thermoelectric generators on the outside cylinder walls of an internal combustion engine. For this research, one outside cylinder wall of a twin cylinder 26 horsepower water-cooled gasoline engine will be implemented with a thermoelectric generator surrogate material. The vertical location of these TEG surrogates along the water jacket will be varied along with the TEG surrogate thermal conductivity. The aim of this proposed dissertation is to attain empirical evidence of the impact, including energy distribution and cylinder wall temperatures, of installing TEGs in the water jacket area. The results can be used for future research on larger engines and will also assist with proper TEG selection to maximize energy recovery efficiencies.

Long-term maternal imprinting of the specific B cell repertoire by maternal antibodies

Maternal antibodies protect newborns whilst they are immunologically immature. This study shows that maternal antibodies can also shape the B cell repertoire of the offspring long after the maternal antibodies themselves become undetectable. V(H)DJ(H) gene-targeted (VI10) mice expressing a heavy chain specific for vesicular stomatitis virus (VSV) produce a 20-fold increased spontaneous titer of VSV-neutralizing antibodies. When transferred from mother to offspring, these antibodies prevented accumulation of Ag-specific transitional type 2 and marginal zone B cells with an activated phenotype and favored selection to the B cell follicles. This effect was B cell-intrinsic and lasted up to adulthood. The pups nursed by mothers producing specific antibodies developed higher endogenous antibody titers of this specificity which perpetuated the effects of specific B cell selection into the mature follicular compartment, presumably by blocking auto-Ag-dependent development of transitional type 2 B cells in the spleen. This repertoire change was functional, as following infection of adult mice with VSV, those pups that had received specific maternal antibodies as neonates had increased pre-immune titers and mounted strong early IgG neutralizing antibodies.

Effects of four-week high-fructose diet on gene expression in skeletal muscle of healthy men

AIMS: A high-fructose diet (HFrD) may play a role in the obesity and metabolic disorders epidemic. In rodents, HFrD leads to insulin resistance and ectopic lipid deposition. In healthy humans, a four-week HFrD alters lipid homoeostasis, but does not affect insulin sensitivity or intramyocellular lipids (IMCL). The aim of this study was to investigate whether fructose may induce early molecular changes in skeletal muscle prior to the development of whole-body insulin resistance. METHODS: Muscle biopsies were taken from five healthy men who had participated in a previous four-week HFrD study, during which insulin sensitivity (hyperinsulinaemic euglycaemic clamp), and intrahepatocellular lipids and IMCL were assessed before and after HFrD. The mRNA concentrations of 16 genes involved in lipid and carbohydrate metabolism were quantified before and after HFrD by real-time quantitative PCR. RESULTS: HFrD significantly (P<0.05) increased stearoyl-CoA desaturase-1 (SCD-1) (+50%). Glucose transporter-4 (GLUT-4) decreased by 27% and acetyl-CoA carboxylase-2 decreased by 48%. A trend toward decreased peroxisomal proliferator-activated receptor-gamma coactivator-1alpha (PGC-1alpha) was observed (-26%, P=0.06). All other genes showed no significant changes. CONCLUSION: HFrD led to alterations of SCD-1, GLUT-4 and PGC-1alpha, which may be early markers of insulin resistance.

Meeting the Challenges of Transdisciplinary Knowledge Production for Sustainable Water Governance

Increasing pressure on mountain water resources is making it necessary to address water governance issues in a transdisciplinary way. This entails drawing on different disciplinary perspectives, different types of knowledge, and different interests to answer complex governance questions. This study identifies strategies for addressing specific challenges to transdisciplinary knowledge production aiming at sustainable and reflective water governance. The study draws on the experiences of 5 large transdisciplinary water governance research projects conducted in Austria and Switzerland (Alp-Water-Scarce, MontanAqua, Drought-CH, Sustainable Water Infrastructure Planning, and an integrative river management project in the Kamp Valley). Experiences were discussed and systematically analyzed in a workshop and subsequent interviews. These discussions identified 4 important challenges to interactions between scientists and stakeholders—ensuring stakeholder legitimacy, encouraging participation, managing expectations, and preventing misuse of data and research results—and explored strategies used by the projects to meet them. Strategies ranged from key points to be considered in stakeholder selection to measures that enhance trustful relationships and create commitment.

The effect of a single 2 h bout of aerobic exercise on ectopic lipids in skeletal muscle, liver and the myocardium.

AIMS/HYPOTHESIS Ectopic lipids are fuel stores in non-adipose tissues (skeletal muscle [intramyocellular lipids; IMCL], liver [intrahepatocellular lipids; IHCL] and heart [intracardiomyocellular lipids; ICCL]). IMCL can be depleted by physical activity. Preliminary data suggest that aerobic exercise increases IHCL. Data on exercise-induced changes on ICCL is scarce. Increased IMCL and IHCL have been related to insulin resistance in skeletal muscles and liver, whereas this has not been documented in the heart. The aim of this study was to assess the acute effect of aerobic exercise on the flexibility of IMCL, IHCL and ICCL in insulin-sensitive participants in relation to fat availability, insulin sensitivity and exercise capacity. METHODS Healthy physically active men were included. [Formula: see text] was assessed by spiroergometry and insulin sensitivity was calculated using the HOMA index. Visceral and subcutaneous fat were separately quantified by MRI. Following a standardised dietary fat load over 3 days, IMCL, IHCL and ICCL were measured using MR spectroscopy before and after a 2 h exercise session at 50-60% of [Formula: see text]. Metabolites were measured during exercise. RESULTS Ten men (age 28.9 ± 6.4 years, mean ± SD; [Formula: see text] 56.3 ± 6.4 ml kg(-1) min(-1); BMI 22.75 ± 1.4 kg/m(2)) were recruited. A 2 h exercise session resulted in a significant decrease in IMCL (-17 ± 22%, p = 0.008) and ICCL (-17 ± 14%, p = 0.002) and increase in IHCL (42 ± 29%, p = 0.004). No significant correlations were found between the relative changes in ectopic lipids, fat availability, insulin sensitivity, exercise capacity or changes of metabolites during exercise. CONCLUSIONS/INTERPRETATION In this group, physical exercise decreased ICCL and IMCL but increased IHCL. Fat availability, insulin sensitivity, exercise capacity and metabolites during exercise are not the only factors affecting ectopic lipids during exercise.

Serotype distribution and antimicrobial susceptibility of group B streptococci in pregnant women: results from a Swiss tertiary centre.

OBJECTIVE To evaluate the rates of penicillin, clindamycin and erythromycin resistance and the serotype distribution among isolates of group B streptococcus (GBS) obtained from pregnant women at the University Hospital of Bern in Switzerland. METHODS We prospectively collected screening samples for GBS colonisation at the University Women's Hospital Bern, Switzerland, between March 2009 and August 2010. We included 364 GBS isolates collected from vaginal, cervical or vaginal-perianal swabs at any gestation time. The minimal inhibitory concentrations for penicillin, clindamycin and erythromycin were established using Etest with 24 hours of incubation, and inducible clindamycin resistance was tested with double disk diffusion tests. Serotyping was done with a rapid latex agglutination test or, if not conclusive, with polymerase chain-reaction (PCR) testing. We looked for significant associations between resistance patterns, age groups, serotype and ethnicity. RESULTS All isolates were susceptible to penicillin. Resistance rates were 14.5% for erythromycin and 8.2% for clindamycin. Of 364 isolates, 5.8% were susceptible to clindamycin but not to erythromycin, although demonstrating inducible clindamycin resistance. Hence, the final reported clindamycin resistance rate was 14%. Serotype III was the most frequent serotype (29%), followed by V (25%) and Ia (19%). Serotype V was associated with erythromycin resistance (p = 0.0007). In comparison with all other ethnicities, patients from Asia showed a higher proportion of erythromycin and clindamycin resistance (p = 0.018). No significant association between resistance patterns and age groups was found. CONCLUSION In pregnant women with GBS colonisation, penicillin is the antibiotic of choice for intrapartum prophylaxis to prevent neonatal early-onset GBS sepsis. In women with penicillin allergy and at high risk for anaphylactic reaction, clindamycin may be an alternative. The resistance rate for clindamycin at our institution was 14%; therefore, susceptibility must be tested before administration.

Therapeutic Targeting of ATP7B in Ovarian Carcinoma.

PURPOSE: Resistance to platinum chemotherapy remains a significant problem in ovarian carcinoma. Here, we examined the biological mechanisms and therapeutic potential of targeting a critical platinum resistance gene, ATP7B, using both in vitro and in vivo models. EXPERIMENTAL DESIGN: Expression of ATP7A and ATP7B was examined in ovarian cancer cell lines by real-time reverse transcription-PCR and Western blot analysis. ATP7A and ATP7B gene silencing was achieved with targeted small interfering RNA (siRNA) and its effects on cell viability and DNA adduct formation were examined. For in vivo therapy experiments, siRNA was incorporated into the neutral nanoliposome 1,2-dioleoyl-sn-glycero-3-phosphatidylcholine (DOPC). RESULTS: ATP7A and ATP7B genes were expressed at higher levels in platinum-resistant cells compared with sensitive cells; however, only differences in ATP7B reached statistical significance. ATP7A gene silencing had no significant effect on the sensitivity of resistant cells to cisplatin, but ATP7B silencing resulted in 2.5-fold reduction of cisplatin IC(50) levels and increased DNA adduct formation in cisplatin-resistant cells (A2780-CP20 and RMG2). Cisplatin was found to bind to the NH(2)-terminal copper-binding domain of ATP7B, which might be a contributing factor to cisplatin resistance. For in vivo therapy experiments, ATP7B siRNA was incorporated into DOPC and was highly effective in reducing tumor growth in combination with cisplatin (70-88% reduction in both models compared with controls). This reduction in tumor growth was accompanied by reduced proliferation, increased tumor cell apoptosis, and reduced angiogenesis. CONCLUSION: These data provide a new understanding of cisplatin resistance in cancer cells and may have implications for therapeutic reversal of drug resistance.

Chondrosarcoma of the mobile spine and sacrum.

Chondrosarcoma is a rare malignant tumor of bone. This family of tumors can be primary malignant tumors or a secondary malignant transformation of an underlying benign cartilage tumor. Pain is often the initial presenting complaint when chondrosarcoma involves the spine. In the mobile spine, chondrosarcoma commonly presents within the vertebral body and shows a predilection for the thoracic spine. Due to the resistance of chondrosarcoma to both radiation and chemotherapy, treatment is focused on surgery. With en bloc excision of chondrosarcoma of the mobile spine and sacrum patients can have local recurrence rates as low as 20%.

PURINERGIC SIGNALING REGULATES FILOPODIA-INDUCED ZIPPERING

The molecular mechanisms that mediate endometrial cancer invasion and metastasis remain poorly understood. This is a significant clinical problem, as there is no definitive cure for metastatic disease. The purinergic pathway’s generation of adenosine and its activation of the adenosine receptor A2B (A2BR) induces cell-cell adhesion to promote barrier function. This barrier function is known to be important in maintaining homeostasis during hypoxia, trauma, and sepsis. Loss of this epithelial barrier function provides a considerable advantage for carcinoma progression, as loss of cell-cell adhesions supports proliferation, aberrant signaling, epithelial-to-mesenchymal transition, invasion, and metastasis. The present work provides strong evidence that CD73-generated adenosine actively promotes cell-cell adhesion in carcinoma cells by filopodia-induced zippering. Adenosine-generating ecto-enzyme, CD73, was down-regulated in moderately- and poorly-differentiated, invasive, and metastatic endometrial carcinomas. CD73 expression and enzyme activity in normal endometrium and endometrial carcinomas was significantly correlated to the epithelial phenotype. Barrier function in normal epithelial cells of the endometrium was dependent on stress-induced generation of adenosine by CD73 and adenosine’s activation of A2BR. This same mechanism inhibited endometrial carcinoma cell migration and invasion. Finally, adenosine’s activation of A2BR induced the formation of filopodia that promoted the re-forming of cell-cell adhesions in carcinoma cells. Overall, these studies identified purinergic pathway-induced filopodia to be a novel mechanism of adenosine’s barrier function and a mechanism that has to be avoided/down-regulated by endometrial carcinoma cells attempting to lose attachment with their neighboring cells. These results provide insight into the molecular mechanisms of endometrial cancer invasion. In addition, because loss of cell-cell adhesions has been closely linked to therapy resistance in cancer, these results provide a rational clinical strategy for the re-establishment of cell-cell adhesions to potentially increase therapeutic sensitivity. In contrast to other molecular mechanisms regulating cell-cell adhesions, the purinergic pathway is clinically druggable, with agonists and antagonists currently being tested in clinical trials of various diseases.

Chapter Six – Individual Trait Variation and Diversity in Food Webs

In recent years, there has been a renewed interest in the ecological consequences of individual trait variation within populations. Given that individual variability arises from evolutionary dynamics, to fully understand eco-evolutionary feedback loops, we need to pay special attention to how standing trait variability affects ecological dynamics. There is mounting empirical evidence that intra-specific phenotypic variation can exceed species-level means, but theoretical models of multi-trophic species coexistence typically neglect individual-level trait variability. What is needed are multispecies datasets that are resolved at the individual level that can be used to discriminate among alternative models of resource selection and species coexistence in food webs. Here, using one the largest individual-based datasets of a food web compiled to date, along with an individual trait-based stochastic model that incorporates Approximate Bayesian computation methods, we document intra-population variation in the strength of prey selection by different classes or predator phenotypes which could potentially alter the diversity and coexistence patterns of food webs. In particular, we found that strongly connected individual predators preferentially consumed common prey, whereas weakly connected predators preferentially selected rare prey. Such patterns suggest that food web diversity may be governed by the distribution of predator connectivity and individual trait variation in prey selection. We discuss the consequences of intra-specific variation in prey selection to assess fitness differences among predator classes (or phenotypes) and track longer term food web patterns of coexistence accounting for several phenotypes within each prey and predator species.

Major challenges in clinical management of TB/HIV co-infected patients in Eastern Europe compared with Western Europe and Latin America.

INTRODUCTION Rates of both TB/HIV co-infection and multi-drug-resistant (MDR) TB are increasing in Eastern Europe (EE). Data on the clinical management of TB/HIV co-infected patients are scarce. Our aim was to study the clinical characteristics of TB/HIV patients in Europe and Latin America (LA) at TB diagnosis, identify factors associated with MDR-TB and assess the activity of initial TB treatment regimens given the results of drug-susceptibility tests (DST). MATERIAL AND METHODS We enrolled 1413 TB/HIV patients from 62 clinics in 19 countries in EE, Western Europe (WE), Southern Europe (SE) and LA from January 2011 to December 2013. Among patients who completed DST within the first month of TB therapy, we linked initial TB treatment regimens to the DST results and calculated the distribution of patients receiving 0, 1, 2, 3 and ≥4 active drugs in each region. Risk factors for MDR-TB were identified in logistic regression models. RESULTS Significant differences were observed between EE (n=844), WE (n=152), SE (n=164) and LA (n=253) for use of combination antiretroviral therapy (cART) at TB diagnosis (17%, 40%, 44% and 35%, p<0.0001), a definite TB diagnosis (culture and/or PCR positive for Mycobacterium tuberculosis; 47%, 71%, 72% and 40%, p<0.0001) and MDR-TB prevalence (34%, 3%, 3% and 11%, p <0.0001 among those with DST results). The history of injecting drug use [adjusted OR (aOR) = 2.03, (95% CI 1.00-4.09)], prior TB treatment (aOR = 3.42, 95% CI 1.88-6.22) and living in EE (aOR = 7.19, 95% CI 3.28-15.78) were associated with MDR-TB. For 569 patients with available DST, the initial TB treatment contained ≥3 active drugs in 64% of patients in EE compared with 90-94% of patients in other regions (Figure 1a). Had the patients received initial therapy with standard therapy [Rifampicin, Isoniazid, Pyrazinamide, Ethambutol (RHZE)], the corresponding proportions would have been 64% vs. 86-97%, respectively (Figure 1b). CONCLUSIONS In EE, TB/HIV patients had poorer exposure to cART, less often a definitive TB diagnosis and more often MDR-TB compared to other parts of Europe and LA. Initial TB therapy in EE was sub-optimal, with less than two-thirds of patients receiving at least three active drugs, and improved compliance with standard RHZE treatment does not seem to be the solution. Improved management of TB/HIV patients requires routine use of DST, initial TB therapy according to prevailing resistance patterns and more widespread use of cART.

Salicylic Acid, a Plant Defense Hormone, Is Specifically Secreted by a Molluscan Herbivore

Slugs and snails are important herbivores in many ecosystems. They differ from other herbivores by their characteristic mucus trail. As the mucus is secreted at the interface between the plants and the herbivores, its chemical composition may play an essential role in plant responses to slug and snail attack. Based on our current knowledge about host-manipulation strategies employed by pathogens and insects, we hypothesized that mollusks may excrete phytohormone-like substances into their mucus. We therefore screened locomotion mucus from thirteen molluscan herbivores for the presence of the plant defense hormones jasmonic acid (JA), salicylic acid (SA) and abscisic acid (ABA). We found that the locomotion mucus of one slug, Deroceras reticulatum, contained significant amounts of SA, a plant hormone that is known to induce resistance to pathogens and to suppress plant immunity against herbivores. None of the other slugs and snails contained SA or any other hormone in their locomotion mucus. When the mucus of D. reticulatum was applied to wounded leaves of A. thaliana, the promotor of the SA-responsive gene pathogenesis related 1 (PR1) was activated, demonstrating the potential of the mucus to regulate plant defenses. We discuss the potential ecological, agricultural and medical implications of this finding.