High-intensity interval training prevents muscle mass loss in overweight Chilean young adults during a hypocaloric-Mediterranean diet: a randomized trial

The hypocaloric Mediterranean diet (MD) mainly reduces fat mass but inevitably causes a loss of skeletal muscle mass. High-intensity interval training (HIIT) seems to have advantages in preserving muscle mass during a hypocaloric regime. Our study compares body composition and metabolic changes in overweight and obese Chilean women and men after 3 months of weight loss treatment with a Mediterranean-type hypocaloric diet, HIIT, or a combination of both. The study included 83 overweight or obese women and men between the ages of 25 and 50. The subjects were randomly assigned to one of the three intervention groups: (1) MD, (2) EX, and (3) MD + EX. Baseline and post-intervention measurements included: (a) body composition by dual-beam densitometry, muscle, and fat measurements by thigh ultrasound and computed tomography; (b) handgrip and quadriceps muscle strength; (c) exercise performance by peak oxygen consumption, peak load, work efficiency, and exercise energy expenditure; and (d) metabolic parameters. Out of 83 participants, the retention rate was 49% due to low compliance with the interventions. As expected, the MD group resulted in significantly greater weight loss (MD -7%, EX -0.6% and MD + EX -5.3%) and appendicular fat mass loss (MD -11.1%, EX -2.9, MD + EX -10.2%) but was associated with significant lean tissue loss (2.8%), which was prevented by HIIT (EX -0.1 and MD + EX -0.6%). Metabolic and glycoxidative parameters remained unchanged, irrespective of changes in body composition. Hypocaloric diets remain the most effective means to lose weight and body fat. However, it induces a loss of lean body mass when not accompanied by exercise training. This study shows that HIIT prevents the loss of muscle mass caused by a hypocaloric Mediterranean diet.

Ultrasound assessment of rectus femoris pennation angle and echogenicity. Their association with muscle functional measures and fat infiltration measured by CT scan

BACKGROUND & AIMS

Ultrasound can be used to measure the pennation angle between muscle fiver and the presumed axis of force generation and muscle echogenicity as an indicator of muscle fat infiltration. We aimed to assess the association of the rectus femoris pennation angle and echogenicity with muscle functional measures. Also, to assess the concordance of rectus femoris echogenicity with muscle fat infiltration as determined by CT scan.

METHODS

Rectus femoris ultrasound pennation angle and thickness were measured in 78 participants aged 69 (65,73) years (37 women). Also hand grip strength, gait speed in 4 m, the 12 min' walk and body composition by DEXA were measured. In a different group of 114 participants aged 44 (31,52) years (80 females), non-dominant rectus femoris echogenicity and thickness were measured by ultrasound and muscle fat infiltration was assessed by CT scan. Handgrip strength and quadriceps torque were also measured.

RESULTS

There was a weak correlation between the pennation angle and rectus femoris thickness in men (r = 0.31 p = 0.05) but not in women (r = 0.29 NS). Women, but not men with a low pennation angle covered a longer distance during the 12 min' walk. The concordance between the z scores of rectus femoris echogenicity and CT radiological density was 0.43 (p < 0.01) and 0.01 (NS) in men and women, respectively. Men and women with an echogenicity below the 25th percentile had a higher quadriceps torque. Men with an echogenicity 25th percentile below 25th percentile had also a higher handgrip strength.

CONCLUSIONS

Rectus femoris pennation angle had a weak or absent association with muscle performance. Rectus femoris echogenicity had a moderate overall concordance with radiological density by CT scan and was inversely associated with quadriceps torque. Therefore, echogenicity was associated with muscle strength, but pennation angle measurement did not contribute to the assessment of muscle function.

MEDICINE ON THE EDGE OF THE HABSBURG TERRITORIES

Designed as a defensive system against the Ottoman Empire, the Austrian military border was doubled by a sanitary cordon, which served as a defense shield against epidemics. In order for this system to function adequately, the border patrol troops that served the House of Habsburg also needed protection against the diseases that threatened the empire. The present study brings into discussion the health problems that border guards from the Banat region experienced, a topic that remains largely unaddressed in the existing literature. By building on original archival research and the specialized work of the epoch, this article traces the main conditions, the means of tackling diseases, the remedies that were specifically local or those found within the European repertoire. It also sheds light on the support that the administrative apparatus offered to the troops, namely medical care in its material form (hospitals, quarantines, pharmacies, medicine, monetary assistance) and human form (the personnel hired at the borders: military doctors, surgeons, midwives, veterinarians). This article concludes that the entire correspondence from the center directed at the local authorities in Banat and vice versa reflects in a unique and subtle way the level of medical knowledge of the time.

Current recommendations for clinical surveillance and genetic testing in rhabdoid tumor predisposition: a report from the SIOPE Host Genome Working Group

The rhabdoid tumor (RT) predisposition syndromes 1 and 2 (RTPS1 and 2) are rare genetic conditions rendering young children vulnerable to an increased risk of RT, malignant neoplasms affecting the kidney, miscellaneous soft-part tissues, the liver and the central nervous system (Atypical Teratoid Rhabdoid Tumors, ATRT). Both, RTPS1&2 are due to pathogenic variants (PV) in genes encoding constituents of the BAF chromatin remodeling complex, i.e. SMARCB1 (RTPS1) and SMARCA4 (RTPS2). In contrast to other genetic disorders related to PVs in SMARCB1 and SMARCA4 such as Coffin-Siris Syndrome, RTPS1&2 are characterized by a predominance of truncating PVs, terminating transcription thus explaining a specific cancer risk. The penetrance of RTPS1 early in life is high and associated with a poor survival. However, few unaffected carriers may be encountered. Beyond RT, the tumor spectrum may be larger than initially suspected, and cancer surveillance offered to unaffected carriers (siblings or parents) and long-term survivors of RT is still a matter of discussion. RTPS2 exposes female carriers to an ill-defined risk of small cell carcinoma of the ovaries, hypercalcemic type (SCCOHT), which may appear in prepubertal females. RT surveillance protocols for these rare families have not been established. To address unresolved issues in the care of individuals with RTPS and to propose appropriate surveillance guidelines in childhood, the SIOPe Host Genome working group invited pediatric oncologists and geneticists to contribute to an expert meeting. The current manuscript summarizes conclusions of the panel discussion, including consented statements as well as non-evidence-based proposals for validation in the future.

A Randomized, Double-Blind, Placebo-Controlled Clinical Trial of an Omega-3 Fatty Acid Supplement in Patients With Predialysis Chronic Kidney Disease

OBJECTIVE

Omega-3 fatty acids may reduce albuminuria and cardiovascular risk factors in patients with chronic kidney disease (CKD). We aimed to assess the effects of omega-3 fatty acid supplementation on albuminuria, blood pressure, pulse wave velocity, and inflammatory markers in patients with CKD.

METHODS

Patients with CKD and a urine albumin excretion of at least 30 mg/g creatinine were supplemented for 3 months with 3,666 mg/day of docosahexaenoic and eicosapentaenoic acids or a corn oil supplement. The study was double blind. At baseline, 6 weeks, and 12 weeks, fasting blood and morning spot urine samples were obtained. Blood pressure, carotid intima media thickness, and pulse wave velocity were measured. The main outcome measure was a reduction of ≥20% in urine albumin.

RESULTS

One hundred patients were randomized (50 received omega-3 fatty acids and 50 received corn oil). Four patients who received omega-3 fatty acids and 5 who received vegetable oil were lost to follow-up. In patients receiving omega-3 fatty acids, the omega-3 index increased from 3.08 (2.32-3.81) to 5.48 (3.045-7.04) percent. A 20% reduction in urine albumin excretion was observed in 13 participants of the control group and 19 participants of omega-3 group (Fisher's exact P = .274). However, the supplement had a significant and positive effect on pulse wave velocity and triglyceride level.

CONCLUSION

An omega-3 fatty acid supplement of 3,666 mg/day did not modify urine albumin excretion in patients with CKD but did improve pulse wave velocity and serum triglyceride levels.

THU0263 LUNG INVOLVEMENT IN PRIMARY SJÖGREN SYNDROME – AN UNDER-DIAGNOSED ENTITY

Background:

Interstitial lung disease (ILD) represents a frequent extra-glandular manifestation of primary Sjögren’s Syndrome (pSS). Limited published data regarding phenotyping and treatment exists. Advances in managing specific ILD phenotypes have not been comprehensively explored in patients with coexisting pSS.

Objectives:

This retrospective study aimed to phenotype lung diseases occurring in a well-described pSS cohort and describe treatment course and outcomes.

Methods:

Between April 2018 and September 2019, all pSS patients attending our Outpatient clinic were screened for possible lung involvement. Clinical, laboratory and computer tomography (CT) findings were analysed. Patients were classified according to CT findings into 5 groups: usual interstitial pneumonia (UIP), non-specific interstitial pneumonia (NSIP), desquamative interstitial pneumonia (DIP), combined pulmonary fibrosis and emphysema (CPFE) and unspecific-ILD.

Results:

Lung involvement was confirmed in 24/240 patients (10%). Clinically manifest pSS occurred later in patients with ILD vs. non-ILD (53.2 [42.0-61.7]vs.62.3 [55.6-68.8] years; p=0.0016). The commonest phenotype was UIP n=10 (41%), followed by NSIP n=7 (29%), DIP n=2 (8%), CPFE n=2 (8%) and unspecific-ILD n=3 (13%). Forced vital capacity (FVC) and carbon monoxide diffusion capacity (DLCO) appeared lower in UIP and DIP, without reaching a significant difference. Treatment focused universally on intensified immunosuppression, with 12/24 patients (50%) receiving cyclophosphamide. No anti-fibrotic treatments were used. Follow-up was median 13.2 [7.9-72.3] months, during which 6/24 (25%) patients exhibited a further decline in FVC. No deaths occurred.

Conclusion:

Lung involvement in pSS is heterogeneous. Better phenotyping and tailored treatment may improve outcomes and requires further evaluation in larger prospective studies.

Disclosure of Interests:

None declared

Association between activity energy expenditure and peak oxygen consumption with sarcopenia

Background

Sedentariness may be an important risk factor for sarcopenia. The aim of this work was to assess the association between muscle mass and strength and markers of usual physical activity such as activity energy expenditure and peak oxygen uptake.

Methods

Young and old participants were assessed measuring body composition by DEXA (double beam X ray absorptiometry), handgrip strength, peak oxygen consumption and workload during an exercise calorimetry in a braked cycle ergometer and a 72 h activity energy expenditure using Actiheart actigraphs. A heart rate/energy expenditure curve derived from the exercise calorimetry was used to calibrate each actigraph. Sarcopenia was defined as having an appendicular fat free mass index below 7.5 kg/m² and 5.6 kg/m² in men and women respectively, or a handgrip strength z score below 1, using local normal data or having both parameters below the cutoff points.

Results

We analyzed data from 192 assessments performed in participants aged 22 to 88 years (106 women). Sarcopenic participants (as determined by muscle mass, strength or both) had a significantly lower peak oxygen uptake and work load and a significantly lower activity energy expenditure. When analyzing lean mass and strength as continuous variables, peak oxygen consumption was a significant predictor of fat free mass in men. Among women, the association was observed only when percentage of muscle mass was expressed as a z score.

Conclusions

Activity energy expenditure and peak oxygen consumption are associated with a lower muscle mass and the presence of sarcopenia and should be considered as risk factors for this condition.

Deficient mitochondrial biogenesis in IL-2 activated NK cells correlates with impaired PGC1-α upregulation in elderly humans

Immunosenescence has been described as age-associated changes in the immune function which are thought to be responsible for the increased morbidity with age. Human Natural Killer (NK) cells are a specialized heterogeneous subpopulation of lymphocytes involved in immune defense against tumor and microbial diseases. Interestingly, aging-related NK cell dysfunction is associated with features of aging such as tumor incidence, reduced vaccination efficacy, and short survival due to infection. It is known that NK cell effector functions are critically dependent on cytokines and metabolic activity. Our aim was to determine whether there is a difference in purified human NK cell function in response to high concentration of IL-2 between young and elder donors. Here, we report that the stimulation of human NK cells with IL-2 (2000 U/mL) enhance NK cell cytotoxic activity from both young and elderly donors. However, while NK cells from young people responded to IL-2 signaling by increasing mitochondrial mass and mitochondrial membrane potential, no increase in these mitochondrial functional parameters was seen in purified NK cells from elderly subjects. Moreover, as purified NK cells from the young exhibited an almost three-fold increase in PGC-1α expression after IL-2 (2000 U/mL) stimulation, PGC-1α expression was inhibited in purified NK cells from elders. Furthermore, this response upon PGC-1α expression after IL-2 stimulation promoted an increase in ROS production in NK cells from elderly humans, while no increase in ROS production was observed in NK cells of young donors. Our data show that IL-2 stimulates NK cell effector function through a signaling pathway which involves a PGC-1α-dependent mitochondrial function in young NK cells, however it seems that NK cells from older donors exhibit an altered IL-2 signaling which affects mitochondrial function associated with an increased production of ROS which could represent a feature of NK cell senescence.

High levels of circulating folate concentrations are associated with DNA methylation of tumor suppressor and repair genes p16, MLH1, and MGMT in elderly Chileans

BACKGROUND

Changes in DNA methylation, one of the most studied epigenetic mechanisms, are considered an initial marker for early cancer detection. We evaluated how availability of dietary factors (folates and vitamin B12) involved in one-carbon metabolism may contribute to DNA methylation changes of cancer-related genes in human subjects.

METHODS

We studied, by pyrosequencing, the methylation of tumor suppressor gene p16, DNA repair genes MLH1 and MGMT, and the repetitive element LINE-1 (as a surrogate for global DNA methylation), in blood of elderly individuals (n = 249) who had been exposed to folic acid (FA) through FA-fortified wheat flour during the last 12 years.

RESULTS

We found that serum folate and to a lesser extent, vitamin B12 concentrations, were significantly correlated with DNA methylation of p16, MLH1, and MGMT, but not with LINE-1. High serum folate concentrations (>45.3 nmol/L) were present in 31.1% of the participants. Although the methylated fraction of CpG sites in p16, MLH1, and MGMT was low (1.17-3.8%), high folate concentrations were significantly associated with methylation at the 3rd tertile of specific CpG sites in all genes with OR between 1.97 and 4.17.

CONCLUSIONS

This study shows that a public policy, like food fortification with FA that increases circulating serum folate levels, could affect methylation levels of specific genes linked to cancer risk. Our present results deserve additional studies to clarify the real impact of high FA levels for risk of cancer in a whole population chronically exposed to a fortified food such as wheat flour.

TRIAL REGISTRATION

ISRCTN 48153354 and ISRCTN 02694183.

[Folate and Pregnancy, current concepts: It is required folic acid supplementation?]

Folate intake during pregnancy is essential for an adequate fetal and placental development and for the long time health of the individual. Its deficiency may induce fetal pathologies, including neural tube disease (NTD). Therefore, several countries implemented public policies to fortify foods with folic acid (FA). Chile started the fortification of wheat flour with FA in the year 2000, decreasing a 43% the prevalence of NTD. However, despite the high consumption of bread (the main fortified food with FA) by our population, a high number of pregnant women consume FA supplements, thus, over passing the maximal recommended FA intake. Additionally, if the diet is reduced in vitamin B12, the optimal ratio folates/vit B12 may be altered, thus inducing changes in the methylation of specific genes and other metabolic pathways, affecting fetal development and the long-term health of the neonates. We think that, after 16 years of the initiation of the fortification of wheat flour with FA, it is necessary to evaluate the possible side effects of a high intake of FA in the pregnant population and their offspring. This article shows antecedents about mechanisms of folates and vit B12 at cellular level, and their possible consequences of an elevated FA maternal intake on the offspring.

Chronic Intestinal Pseudo-obstruction: Clinical and Manometric Characteristics in the Chilean Population

Background/Aims

Chronic intestinal pseudo-obstruction (CIPO) is a rare syndrome characterized by a failure of the propulsion of intraluminal contents and recurrent symptoms of partial bowel obstruction in the absence of mechanical obstruction. Regional variations of the intestinal compromise have been described. Intestinal manometry can indicate the pathophysiology and prognosis. Our objective is to establish the demographic and clinical characteristics of group Chilean patients and analyze the motility of the small intestine and its prognostic value.

Methods

Patients with symptoms of intestinal pseudo-obstruction with dilated bowel loops were included, in all of whom a manometry of the small intestine was performed using perfused catheters.

Results

Of the 64 patients included, 51 women (average age 41.5 ± 17.6 years), 54 primary and 10 secondary CIPO were included. Dilatation of the small intestine was the only finding in 38 patients; in the remaining, the compromise was associated with other segments, primarily the colon. Forty-nine patients underwent 65 surgeries, mainly exploratory laparotomies and colectomies. Intestinal manometry was performed on all patients; 4 "patterns" were observed: neuropathic (n = 26), myopathic (n = 3), mixed (n = 24), and a group without motor activity (n = 11). The most relevant findings were the complex migrating motor disorders and decreased frequency and propagation of contractions. The 9 patients who died had a severe myopathic compromise.

Conclusions

In our series, isolated small bowel compromise was the most common disorder. Neuropathic motor compromise was observed in most of the patients. Mortality was associated with severe myopathic compromise.

Folate Transporters in Placentas from Preterm Newborns and Their Relation to Cord Blood Folate and Vitamin B12 Levels

Folate deficiency during pregnancy has been related to low birth weight, preterm (PT) birth and other health risks in the offspring; however, it is unknown whether prematurity is related to low folate transport through the placenta due to altered expression of specific folate transporters. We determined placental expression (mRNA and protein concentrations by RT-qPCR and WB respectively) of specific folate transporters: RFC, PCFT/HCP1 and FOLR1 in chorionic (fetal) and basal (maternal) plates of placentas of PT pregnancies (PT, 32–36 weeks, n = 51). Term placentas were used as controls (T, 37–41 weeks, n = 47). Folates and vitamin B12 levels were measured by electrochemiluminescence in umbilical cord blood of newborns. FOLR1 mRNA expression was lower and protein concentration higher in PT placentas (both plates) relative to the control group (p <0.05). In addition, gestational age was positively correlated with mRNA expression (Rho = 0.7), and negatively with protein concentration (Rho = -0.7 for chorionic and -0.43 for basal plate). PCFT/HCP1 mRNA was lower in PT placentas, without changes in protein levels. RFC did not differ in PT placentas compared to controls. PT newborns presented higher cord blood folate level (p = 0.049) along with lower vitamin B12 concentration compared to controls (p = 0.037).In conclusion, placental FOLR1 mRNA was positively associated with gestational age. Conversely, FOLR1 protein concentrations along with folate/vitamin B12 ratio in cord blood were negatively associated with gestational age. Placental FOLR1 is likely the main placental folate transporter to the fetus in newborns.

Premature loss of muscle mass and function in type 2 diabetes

INTRODUCTION

Muscle mass and function are among the most relevant factors that contribute to an optimal quality of life, and are strong predictors of mortality in the elderly. Loss of lean tissues and deterioration of muscle function have been described as one of the many complications of type 2 diabetes mellitus (DM2), but most studies do not isolate age as an intervening factor.

AIM

To study whether adult DM2 patients up to 60years of age have decreased muscle mass and function compared with healthy non-diabetic (ND) subjects of similar age.

METHODOLOGY

Appendicular fat-free mass (ApFFM) by dual X-ray absorptiometry (DEXA), handgrip strength (HS), quadriceps strength (QS), 12 min walking capacity (12MW) and the Timed Up and Go test (TUG) were measured in 100 DM2 patients and 39 ND controls. Muscle quality, or the ratio between lean mass and muscle strength of upper and lower limbs, and the functional limitations associated with pain and stiffness assessed according to the Western Ontario and McMaster Universities Arthrosis Index (WOMAC) were also recorded. Specific tests were performed to rule out microvascular diabetic complications (retinal and peripheral nerves), metabolic control, kidney function and vitamin D status and examine their association with ApFFM and function.

RESULTS

ApFFM was significantly higher among DM2 female patients and lower among diabetic men. However opposite results were obtained when individual values were corrected for body mass index (BMI), specifically among women, who were more likely to be obese. As for muscle strength and global functionality tests, significantly better performances in TUG, 12MW, QS and HS were observed among ND subjects of both sexes. These differences prevailed even after excluding diabetic patients with microvascular complications as well as those with more than 10years of diabetes. Muscle quality was also significantly better among ND women. Higher scores of pain and stiffness in the WOMAC scale correlated with 12MW and TUG in both groups but did not correlate with ApFFM.

CONCLUSIONS

We found a clear deterioration of lean mass and muscle functions among adult DM2 patients of up to 60years old, independent of length of disease, metabolic control, vitamin D status and presence of microvascular complications and pain.

Mathematical modeling of Myosin induced bistability of Lamellipodial fragments

For various cell types and for lamellipodial fragments on flat surfaces, externally induced and spontaneous transitions between symmetric nonmoving states and polarized migration have been observed. This behavior is indicative of bistability of the cytoskeleton dynamics. In this work, the Filament Based Lamellipodium Model (FBLM), a two-dimensional, anisotropic, two-phase continuum model for the dynamics of the actin filament network in lamellipodia, is extended by a new description of actin–myosin interaction. For appropriately chosen parameter values, the resulting model has bistable dynamics with stable states showing the qualitative features observed in experiments. This is demonstrated by numerical simulations and by an analysis of a strongly simplified version of the FBLM with rigid filaments and planar lamellipodia at the cell front and rear.

Estimated glomerular filtration rate, urine albumin excretion, and survival among patients consulting in public Chilean public primary care clinics

Chronic renal disease (CRD) in its pre-dialysis stage is an important risk factor for mortality among adults. The aim of this study was to assess the effects of CRD on mortality among consultants in Chilean public primary care clinics. We obtained information about serum creatinine, urinary albumin excretion (UAE), blood pressure, and body mass index of 5224 consultants [3379 females aged 67 (59-75) years and 1845 males aged 68 (59-75) years] in three clinics of Metropolitan Santiago. Kaplan-Meier curves and Cox proportional hazard regression models were used to determine risk factors for mortality, determined 41 months after obtaining the blood samples. During the follow-up period, 262 patients died (33% due to circulatory causes and 29% due to tumors). Kaplan-Meier curves showed that there was a significant association between survival, estimated glomerular filtration rate, and UAE. Cox models showed that serum creatinine, UAE, a lower body mass index, and a history of diabetes were significant mortality predictors. A sensitivity analysis performed eliminating extreme ages (less than 50 and more than 80 years), included high diastolic pressure as a predictor of survival. We conclude that among patients with CRD in its pre-dialysis stage, UAE is an important predictor of survival, along with serum creatinine. A low body mass index was associated with a higher mortality.

Relationship between folate transporters expression in human placentas at term and birth weights

BACKGROUND

Adequate folate levels are essential for successful pregnancy outcomes. We aimed to study the relationship between placental mRNA and protein levels of folate transporters to birth weight.

METHODS

Placental folate transporters (FOLR1, RFC1 and HCP1/PCFT) mRNA and protein levels in basal (BP) and chorionic plate (CP) of small (SGA), appropriate (AGA) and large (LGA) for gestational age term infants (≥37 weeks gestation, n = 111) were determined by real-time PCR and Western blot respectively.

RESULTS

FOLR1 and HCP1/PCFT mRNA were lower in both plates of SGA and LGA placentas compared to AGA (p < 0.01) and RFC1 mRNA was lower only in CP (p < 0.02). RFC1 protein levels were lower in BP of SGA (p < 0.05) and LGA (p < 0.01), and FOLR1 protein levels were lower in CP of SGA (p < 0.02) and LGA (p < 0.01) groups compared to AGA. HCP1/PCFT protein levels remained unchanged in all groups.

CONCLUSION

Placentas of SGA and LGA groups showed a reduced mRNA expression and protein levels of folate transporters, with some differences depending on the location within the placenta (BP or CP). This suggests the presence of specific placental regulation mechanisms in gene expression that may be associated to birth weight.

Is L-methionine a trigger factor for Alzheimer's-like neurodegeneration?: Changes in Aβ oligomers, tau phosphorylation, synaptic proteins, Wnt signaling and behavioral impairment in wild-type mice

BACKGROUND

L-methionine, the principal sulfur-containing amino acid in proteins, plays critical roles in cell physiology as an antioxidant and in the breakdown of fats and heavy metals. Previous studies suggesting the use of L-methionine as a treatment for depression and other diseases indicate that it might also improve memory and propose a role in brain function. However, some evidence indicates that an excess of methionine can be harmful and can increase the risk of developing Type-2 diabetes, heart diseases, certain types of cancer, brain alterations such as schizophrenia, and memory impairment.

RESULTS

Here, we report the effects of an L-methionine-enriched diet in wild-type mice and emphasize changes in brain structure and function. The animals in our study presented 1) higher levels of phosphorylated tau protein, 2) increased levels of amyloid-β (Aβ)-peptides, including the formation of Aβ oligomers, 3) increased levels of inflammatory response,4) increased oxidative stress, 5) decreased level of synaptic proteins, and 6) memory impairment and loss. We also observed dysfunction of the Wnt signaling pathway.

CONCLUSION

Taken together, the results of our study indicate that an L-methionine-enriched diet causes neurotoxic effects in vivo and might contribute to the appearance of Alzheimer's-like neurodegeneration.

FACTORS RELATED TO TOTAL ENERGY EXPENDITURE IN OLDER ADULTS (CHILE)

AIM

to asses Total Energy Expenditure (TEE) in healthy Chilean institutionalized or independently older people Methods: twenty seven young (27-30 years), 27 institutionalized (> 65 years old) and 27 free-living older (> 65 years old) participants were studied. Body composition was estimated by dual energy X-ray absorptiometry. Physical activity energy expenditure (AEE) and TEE were assessed using Actiheart accelerometers. The Mini Nutritional Assessment (MNA) was applied and Timed Up and Go (TUG) was measured.

RESULTS

AEE was 171, 320 and 497 kcal/day in institutionalized, free living older and young participants, respectively (p < 0.01 between young and older participants). Both absolute TEE and TEE/RMR was higher in young people. Multiple regression analysis accepted age, MNA and TUG as significant predictors of AEE (r2 = 0.24 p < 0.01).

CONCLUSION

AEE and PAL were lower among older people, with no differences by institutionalization.

[A role for the endocannabinoid system in hepatic steatosis]

The endocannabinoid system (SEC) is an important modulator of several metabolic functions. This system is composed by cannabinoid receptors type 1 and 2 (RCB1 and RCB2), their endogenous ligands, known as endocannabinoids, and the enzymes involved in their synthesis and degradation. A deregulated SEC originates metabolic alterations in several tissues, resulting in the typical manifestations of the metabolic syndrome. Liver steatosis of different origins constitutes a physiopathological condition where an altered hepatic SEC is observed. In this condition, there is an increased expression of RCB1 and/or higher endocannabinoid levels in different hepatic cells, which may exert an autocrine/paracrine hyperstimulation of RCB1/RCB2. Activation of RCB1 stimulate the expression of several hepatocyte lipogenic factors, thus leading to increased de novo fatty acids synthesis and consequently to an abnormal accumulation of triglycerides. The effect of RCB2 activity on hepatic function is still controversial because, on one side its stimulation has an interesting protective effect on alcoholic liver disease while, on the other, it may enhance the development of hepatic steatosis in experimental models of diet-induced obesity. In this review we discuss the proposed mechanisms by which SEC is involved in the etiology of hepatic steatosis, as well as the therapeutic possibilities involving peripheral RCB1/RCB2 antagonism/agonism, for the treatment of this condition.

Skeletal muscle ceramide species in men with abdominal obesity

BACKGROUND

Obesity is a risk factor for diabetes and its consequences, including accelerated ageing and mortality. The underlying factor could be accumulation of certain lipid moieties, such as ceramides (CER) and diacylgycerol (DAG) within muscle tissue, which are known to promote insulin resistance (IR), induce inflammation and oxidative injury, ultimately altering muscle function.

AIM

First, to study the relationship between body composition and age (independent variables) with skeletal muscle accumulation of lipid species, oxidative injury and strength. Second, to analyze the relationship between muscle tissue metabolites and insulin resistance, inflammation and lymphocyte telomere length, the latter as an indicator of ageing.

METHODOLOGY

The sample included 56 healthy sedentary males, scheduled for inguinal hernia surgery, aged 27 to 80 y. Each individual was subject to anthropometric measurements, body composition assessment through radiologic densitometry (DEXA), measurement of handgrip and quadriceps strength, serum biochemical parameters (lipoproteins, creatinine, high sensitivity C reactive protein [hsCRP], fasting and post glucose insulin and glucose concentrations for calculation of IR through the Matsuda and HOMA-IR indexes), and extraction of peripheral leukocytes for measurement of telomere length. During the surgical procedure, a sample of muscle tissue was obtained (anterior abdominal oblique) in order to measure CER and DAG (and sub species according to chain length and saturation) by mass spectrometry, 4 hydroxy-2-nonenal adducts (4-HNE) using electron microscopy immunohistochemistry, and carboxymethyl-lisine (CML) by immunohistochemistry, the latter as indicators of oxidative stress (OS).

RESULTS

Body mass index (BMI) of twenty six individuals was > 25 k/m2, while BMI of 7 was > 30 k/m2. Overweight/obese individuals, did not exhibit differences in skeletal muscle lipid metabolites, however total CER and specific long chain CER sub-species (20 and 22 carbon) increased significantly among individuals with a central fat distribution (n = 14) as well as in glucose intolerant subjects (n =23). A negative association was found between mononuclear leukocyte telomere length and 20 and 22 carbon CER (rho = - 0.4 and -0.5 0 p < 0.05). Muscle strength was not associated with any of the measured muscle metabolites or markers of OS. A multiple regression analysis accepted central abdominal fat and telomere length as significant predictors of CER (R2 = 0.28).

CONCLUSIONS

An association was found between accumulation of specific ceramide species in muscle tissue and abdominal obesity, glucose intolerance and shortening of leukocyte telomeres, although not with muscle oxidative injury or dysfunction.

Folates Induce Colorectal Carcinoma HT29 Cell Line Proliferation Through Notch1 Signaling

Folic acid (FA) consumption at high levels has been associated with colon cancer risk. Several mechanisms have been proposed to explain this association. The Notch signal pathway has been implicated in the regulation of cellular proliferation. Our aim was to demonstrate that high concentrations of FA or its reduced form, 5-methyltetrahydrofolic acid (5-MTHF), increase colorectal carcinoma HT29 cell proliferation through an increase of Notch1 activation and to prove if the inhibition of Notch1 activation by gamma secretase inhibitor, reduce the effect of folic acid. HT29 cells were cultured in high (400 nM), low (20 nM), or 0 nM FA or 5-MTHF concentrations during 96 h with or without DAPT (gamma secretase inhibitor). Cell proliferation was determined by the methylthiazole tetrazolium method, and Notch1-intracellular domain (NICD) was analyzed by flow cytometry. HT29 cells exposed to 400 nM FA or 5-MTHF showed higher proliferation rate than those exposed to 20 nM of FA or 5-MTHF (P < 0.01) during 96 h. NICD expression increased at higher FA or 5-MTHF concentrations compared with lower concentrations (P < 0.01). This effect on proliferation was partially reversible when we blocked Notch1 activation with the inhibitor of γ-secretase (P < 0.05).These data suggest that high concentration of FA and 5-MTHF induce HT29 cell proliferation activating Notch1 pathway.

Folic acid supplementation during pregnancy induces sex-specific changes in methylation and expression of placental 11β-hydroxysteroid dehydrogenase 2 in rats

In the placenta, 11β-hydroxysteroid dehydrogenase type 2 (11β-HSD2) limits fetal glucocorticoid exposure and its inhibition has been associated to low birth weight. Its expression, encoded by the HSD11B2 gene is regulated by DNA methylation. We hypothesized that maternal diets supplemented with folic acid (FA) during pregnancy modify the expression of placental HSD11B2 through gene methylation. Wistar rats were fed with high (8 mg/kg) or normal low (1mg/kg, control) levels of FA during pregnancy. Concentrations of mRNA and protein in placentas were determined by qRT-PCR and Western blot respectively. Methylation in five CpG sites of the placental HSD11B2 promoter (-378 to -275) was analyzed by bacterial cloning and subsequent sequencing. In the FA-supplemented group, mRNA and protein levels of 11β-HSD2 decreased by 58% and increased by 89%, respectively, only in placentas attached to males. In controls, most CpG sites were not methylated except for the CpG2 site which was 80% methylated. CpG2 methylation level increased under the FA treatment; however, only in placentas attached to females was this increase significant (113%). This change was not related to HSD11B2 expression. Fetal weight of females from FA- supplemented mothers was 6% higher than females from control mothers. In conclusion, this is the first study reporting that FA over supplementation during pregnancy modifies the placental HSD11B2 gene expression and methylation in a sex-dependent manner, suggesting that maternal diets with high content of FA can induce early sex-specific responses, which may lead to long-term consequences for the offspring.

Variability of formulas to assess insulin sensitivity and their association with the Matsuda index

OBJECTIVE

To assess the individual variability of HOMA and QUICKI indexes for the assessment of insulin resistance, using three fasting blood samples obtained within 30 minutes.

RESEARCH METHODS & PROCEDURES

Data from 80 participants aged 41.5 ± 15 years (26 females), who underwent an oral glucose tolerance test to calculate Matsuda index, were used. Every participant had three fasting blood samples obtained within 30 minutes and four blood samples obtained at 30, 60, 90 and 120 minutes after a 75 g oral glucose load. Insulin and glucose were measured in each sample. HOMA and QUICKI indexes were calculated using the nine possible combinations of the three fasting blood samples. Matsuda index was calculated with all samples obtained.

RESULTS

Median values of HOMA-IR, HOMA-β, QUICKI and Matsuda indexes were 1.9, 117.9, 0.35 and 3.71 arbitrary units, respectively. The individual variation coefficients of HOMA-IR, HOMA-β and QUICKI were 11.8 (7.8-18.9), 15 (10.2-22.9) and 1.8 (8.8-21.9) % respectively. When compared with Matsuda index, the R squared values of HOMA-IR, HOMA-β and QUICKI were 0.46, 0.2 and 0.71, respectively.

CONCLUSIONS

Among fasting indexes for insulin resistance, QUICKI had the lower variation coefficient and the higher correlation with Matsuda index.

Central obesity and not age increases skeletal muscle lipids, without influencing lean body mass and strength

BACKGROUND/AIMS

To measure skeletal muscle lipid infiltration, its association with insulin resistance (IR) lean mass and function, in Chilean men differing in age and body composition. Our hypothesis was that muscle lipid accumulation would be higher among older and heavier individuals and this would deteriorate insulin sensitivity (IS) and decrease muscle mass and function, both features of the ageing process.

METHODS

Healthy men (38 < 55 and 18 > 65 years), underwent anthropometric measurements, body composition assessment through radiologic densitometry, Nuclear Magnetic Resonance spectroscopy at the tibialis anterioris muscle to measure intra (IMCL) and extramyocellular lipids (EMCL), quadriceps and handgrip strength, 12 minute walking distance and serum biochemistry (haemoglobin, lipoproteins, creatinine, ultrasensitive C Reactive Protein, fasting and post glucose insulin and glucose concentrations, to assess IS). Physical activity was estimated by actigraphy.

RESULTS

23 men were eutrophic, 26 were overweight and 7 were obese and mostly sedentary, independent of age. Both IMCL and EMCL were higher in overweight/ obese men. Abdominal fat was negatively associated with IS and positively correlated with muscle lipid accretion (both IMCL and EMCL), but not with age. As expected, older individuals had lower muscle mass and strength, but not more adipose tissue nor intramyocellular lipids, yet were more glucose intolerant.

CONCLUSIONS

central obesity was associated with IMCL and EMCL infiltration and IR. This type of lipid accretion was not related with ageing nor age-related sarcopenia. Older individuals were more glucose intolerant, which was explained by a decrease of insulin secretion more than adiposity-related IR.

[Evaluation of a program for management of metabolic syndrome in adults with overweight and obesity]

BACKGROUND

The Chilean Ministry of Health developed a healthy lifestyles intervention directed to adults with overweight and cardiovascular risk factors, called "Program on Healthy Eating and Physical Activity" (PASAF).

AIM

To evaluate the impact of PASAF on nutritional status and metabolic parameters.

PATIENTS AND METHODS

We analyzed databases from three primary care centers belonging to a municipality of Metropolitan Santiago. We selected adults enrolled in the PASAF during three years (2007-2009). The program lasted four months and included an assessment of anthropometric and metabolic parameters at baseline and at the end, eight workshops with a nutritionist, seven with a psychologist and 32 sessions of physical activity.

RESULT

We evaluated 526 subjects aged ≥18 years (93% females), of whom 85.6% attended the last appointment for assessment. Analyzing available data, attendance to workshops was <50% of the scheduled sessions. Weight, body mass index and waist circumference decreased significantly (median: -1.4 kg, -0.6 kg/m² and -3 cm, respectively). The median weight loss was 1.8% of initial weight and 17.1% of participants experienced a decrease ≥5% of their initial weight. There were significant improvements in lipid levels and blood pressure among participants with lower initial excess weight. A reduction in fasting blood glucose was observed only among subjects who lost ≥5% of their initial weight.

CONCLUSIONS

The PASAF modestly reduced nutritional parameters. Correction of metabolic parameters was especially effective in less obese subjects. The attendance to workshops was low.

Bariatric surgery decreases carotid intima-media thickness in obese subjects

BACKGROUND

Obesity has long been associated with an increased risk of cardiovascular disease (CVD). The aim of this study was to evaluate the impact of substantial weight loss induced by bariatric surgery on carotid intima media thickness (C-IMT) (surrogate marker of early atherosclerosis) and classic factors of cardiovascular risk (CVRFs).

METHODS

thirty-one obesity patients were evaluated for bariatric surgery. Twenty-seven were undergone surgery, 14 Roux-en-Y gastric bypass surgery (GBS) and 13 sleeve gastrectomy. The four obese patients who did not undergo surgery, were performed the same evaluations.

MEASUREMENTS

Body weight, BMI, blood pressure, total cholesterol, TC levels, LDL-C, HDL-C, TG, fasting plasma glucose and insulin, HOMA IR, and US B-mode C-IMT was measured.

RESULTS

After 354 ± 92 days follow up, 27 patients that underwent bariatric surgery evidenced a mean body mass index decrease from 38 to 27 k/m² (p < 0.001), simultaneously was observed improvement in CVRFs, 10 years Framingham risk and a significant reduction of therapeutic requirements. C-IMT diminished from a mean of 0.58 ± 0.14 mm to 0.49 ± 0.09 mm (p = 0.0001). Four patients that did not undergo surgery increased C-IMT from 0.52 ± 0.12 to 0.58 ± 0.13 mm (p = 0.03) with no significant changes in CVRFs.

CONCLUSION

Weight loss, one year after bariatric surgery, GBS and sleeve gastrectomy, decreases C-IMT; improve CVRFs and 10 years Framingham risk.

Variability of glycemic and insulin response to a standard meal, within and between healthy subjects

AIM

To test the variability within and between subject of glycemic response test following the ingestion of a standard food.

MATERIAL AND METHODS

Glucose and insulin response of a standard meal (white bread) was performed in ten healthy volunteers and repeated under identical conditions for 6 times. Blood glucose and insulin levels were measured in the fasted state and over the 180 min following commencement of consumption of the foods The Area Under the Curve (AUC) for glucose and insulin was calculated for the values above baseline for the 3-hour period following the standard meal. Within and between coefficient of variation was calculated.

RESULTS

The total intra-individual variation of the gAUC was 51.8% range 24.9 to 91.4%. The inter-individual variation of the gAUC in the complete study was 75.2% . The total intra-individual variation of the iAUC was 51.9%. ranged: 7.7 to 103%. The inter-individual variation in the complete study was 86%.

CONCLUSION

Glucose and insulin response to a reference food has low reliability, therefore limits its clinical utility for individual dietary prescription.

Dietary intake increases serum levels of carboxymethil-lysine (CML) in diabetic patients

INTRODUCTION

Advanced glycation end products are produced endogenously, in association with hyperglycemia and oxidative stress. They can also be generated during cooking or food processing and, once absorbed, alter protein function and promote inflammation.

METHODS

We selected 40 healthy male subjects, 17 patients with type 2 diabetes of both sexes and 15 patients with type 1 diabetes of both sexes. Each participant underwent both a food frequency questionnaire (FFQ) and 24-hour dietary recall specially adapted for measuring CML intake, anthropometry, measurement of blood pressure and biochemical parameters in blood and urine.

RESULTS

Serum CML levels were significantly higher in patients with diabetes compared to healthy subjects (p 0.04), showing a direct relationship between dietary intake and serum levels of CML in T2D patients (r 0.53 p 0.03). sCML levels correlated positively with length of diabetes mellitus, and inversely with body mass index (BMI). The most important dietary factor contributing to raise CML levels in these patients with diabetes was the consumption of milk powder.

CONCLUSION

Serum levels of CML were found to be higher among diabetic subjects, associated to length of diabetes as expected, but also with the ingestion of foods containing higher amounts of ML. The consumption of milk powder in this group is a major determinant of increased serum levels.

Carotid ultrasound examination as an aging and disability marker

AIM

To explore the usefulness of carotid ultrasound examination as a marker of aging and predictor of disability among older people.

METHODS

Carotid ultrasound, measuring carotid intima media thickness (CIMT) and recording the presence of plaques, was carried out in 152 adults aged 29-59 years (47 women) and in 107 older adults aged 61-88 years (86 women). In all, clinical routine laboratory parameters and lymphocyte telomere length as T/S ratio were measured. Among older adults, 12-min walk, timed up and go, hand grip and quadriceps strength were determined.

RESULTS

CIMT was significantly higher among older people and T/S ratio was significantly higher in young women. Carotid plaques were found in one adult and 17 older people. A multiple regression analysis accepted age, systolic blood pressure and T/S ratios as independent predictors of CIMT (R(2) = 0.51). Among older people, a logistic regression accepted age and the presence of carotid plaques as significant predictors of a 12-min walk speed below 1 m/s.

CONCLUSIONS

An abnormal 12-min walk as an indicator of functional decline among older people is associated with the presence of carotid artery plaques. CIMT is independently associated with age.

Patient-activated three-dimensional multifrequency magnetic resonance elastography for high-resolution mechanical imaging of the liver and spleen

PURPOSE

To introduce a novel in-vivo three-dimensional multifrequency magnetic resonance elastography (3D-MMRE) method for high-resolution mechanical characterization of the liver and spleen.

MATERIALS AND METHODS

Ten healthy volunteers were examined by abdominal single-shot 3D-MMRE using a novel patient-activated trigger system with respiratory control. 10 contiguous slices with 2.5  mm cubic voxel resolution, 3 wave components, 8 time steps, and 2 averages were acquired at 7 mechanical excitation frequencies from 30 to 60  Hz. The total imaging time was approximately 15  min. For postprocessing, multifrequency dual elasto-visco (MDEV) inversion was used to calculate high-resolution mechanical parameter maps of the abdomen including the liver and spleen.

RESULTS

Two parameters maps were generated from each image slice to capture the magnitude and the phase angle of the complex shear modulus. Both parameters depicted the mechanical structures of the abdomen with unprecedented high spatial resolution. Spatially averaged group mean values of the liver and spleen are 1.27 ± 0.17 kPa and 2.01 ± 0.69 kPa, indicating a significantly higher asymptomatic stiffness of the spleen compared to the liver.

CONCLUSION

Patient-activated respiratory-gated 3D-MMRE combined with MDEV inversion provides highly resolved mechanical maps of the liver and spleen that are superior to previous elastograms measured by abdominal MRE.

Natural killer cell cytotoxicity is not regulated by folic acid in vitro

OBJECTIVES

Folate supplementation may be associated with an increased risk of developing several types of cancer and a derangement of immune function. Among the latter, Natural killer (NK) cells are involved in non-MHC-restricted natural immunity against malignant target cells. Abnormalities in NK cell number or function have been associated with a higher cancer risk. The aim of this study was to study in vitro the possible effect of different concentrations of 5-methyltetrahydrofolic acid (5-MTHF) or folic acid on NK cell cytotoxic function, and expression of the stimulatory and inhibitory receptors KIRDL4, KIRDL3, and NKG2D.

METHODS

Volunteer-derived peripheral mononuclear cells (PBMC) and highly enriched NK cells (95% CD56+ CD16+) were grown in folic acid free-RPMI 1640, supplemented either with folic acid or 5-MTHF (15-100 nM) during 72 h to 96 h.

RESULTS

No differences in the cytolytic activity of PBMC and enriched NK cells were observed. After 96 h of in vitro culture without folate or supplemented with FA or 5-MTHF (30 or 100 nM), there were no changes in the percentage of HPNK receptor-positive cells.

CONCLUSIONS

Our data indicate that a high dose of 5-MTHF or folic acid does not influence NK cell function in vitro.

Epigenetic variation, inheritance, and selection in plant populations

Plant populations show phenotypic diversity, which may be caused by genetic and epigenetic variation. It has recently been shown that new epigenetic variants are generated at a higher rate than genetic variants and several studies have shown that epigenetic variation can be influenced by the environment. Although the heritability of environmentally induced epigenetic traits has gained increasing interest in past years, it is still not clear whether and to what extent induced epigenetic changes have a role in ecology and evolution. Some reports on model and nonmodel species support the possibility of adaptive epigenetic alleles, indicating that epigenetic variants are subject to natural selection. However, most of these studies rely solely on phenotypic data and no information is available about the underlying mechanisms. Thus, the role of inherited epigenetic variation for plant adaptation is unclear and further investigations are required to gain insights into the significance of epigenetic variation for ecological and evolutionary processes. Here, we review mechanisms of epigenetic regulation, epigenetic responses to environmental challenges, their inheritance, and their implication for adaptation and plant evolution.

Quality of life of older Chilean subjects living in metropolitan Santiago, Chile. Influence of socioeconomic status

Quality of life (QOL) of older people is becoming an important public health concern and should be evaluated. The aim of this study was to evaluate socioeconomic and individual determinants of QOL of older subjects living in metropolitan Santiago, Chile. We first carried out a qualitative phase with focus groups of older people. According to the conclusions of the focus groups, a questionnaire about QOL was devised and added to the WhoQoL (World Health Organization Quality of Life) and WHOQoL-Old brief questionnarires. The final document with 85 questions was applied to healthy older subjects living in the community. A total of 1,676 subjects aged 71.8±7.4 years (1,189 women) took part in the survey. A multiple stepwise regression model showed that a higher socioeconomic level, a better educational level, performing voluntary work, having a partner, participating in groups with other older people, and being younger were factors independently associated with a higher QOL. A principal components analysis showed that psychological health and social relationships were the main domains that explained the total quality of life score. Psychological health and social relationships were the main determinants of QOL in this sample of older Chilean people living in metropolitan Santiago.

[A pilot study on physical training of patients in hemodialysis]

BACKGROUND

Exercise training during the dialytical procedure may have positive cardiovascular effects and prevent or revert muscle wasting in patients undergoing chronic hemodialysis.

AIM

To evaluate the effects of an exercise training program in patients undergoing chronic hemodialysis.

MATERIAL AND METHODS

Fifteen patients on chronic hemodialysis aged 21 to 69 years (three females) were included in the study. Nine of these were included in an exercise training program. During 16 weeks, exercise sessions were carried out during each dialytical procedure that included a warm-up period, aerobic exercises done using standing cycles, and resistance exercises, performed using Thera-Band(®) elastic bands and loops. Borg scale was used to control the intensity of training. At baseline and at the end of the study, a blood sample prior and after the dialytical procedure was obtained to measure C reactive protein, tumor necrosis factor α and interleukin 6. Quadriceps muscle strength, six minutes' walk and quality of life using the SF-36 questionnaire, were also measured.

RESULTS

Four experimental subjects did not complete the study period, two that withdrew before starting, one due to problems with the venous access and one that decided to withdraw after 1 month of training. Among the five patients that finished the training period, significant improvements in the six minutes' walk and quadriceps strength were observed in the experimental group. No significant changes were observed among controls. No changes were observed in either group in C reactive protein, tumor necrosis factor and interleukin 6 levels or quality of life.

CONCLUSIONS

Among patients undergoing chronic hemodialysis exercise training improves endurance and muscle strength.