[Assessment of calf circumference as an indicator of the risk for hyponutrition in the elderly]

BACKGROUND

Undernutrition is a very common situation among elderly, that is associated with increased morbidity and mortality rates. On the other hand, calf circumference (CC) is a direct anthropometric measurement, related to fat free mass. An early detection of an elderly undernutrition situation, based on CC assessment, could contribute to prevent its development and consequences.

OBJECTIVE

To analyse the relationship between CC and a possible undernutrition situation, based on the application of the Mini Nutritional Assessment (MNA) test, among Spanish subjects of 65 or more years old, including the gender and age influences.

SUBJECTS AND METHODS

A cross-sectional study was carried out to assess the nutritional situation of an ambulatory population, from every area of Spanish geography (n = 22007), using the questionnaire MNA. Every subject surveyed was 65 or more years old when the test was done.

RESULTS

There were statistically significant differences between subjects with a CC < 31 cm and those with CC >or= 31 cm, both men and women, in weight, height, body mass index (BMI), MNA total score and undernutrition classification. On the other hand, it was found that those elders with lower CC showed a higher undernutrition risk, both men and women, in every age range studied.

CONCLUSIONS

It does exit an association between CC of Spanish subjects of 65 or more years old and the risk of developing undernutrition. That association is similar among men and women, and in all age ranges.

The - 11391 G/A polymorphism of the adiponectin gene promoter is associated with metabolic syndrome traits and the outcome of an energy-restricted diet in obese subjects

Adiponectin is an adipose tissue-specific hormone that is commonly decreased in obese subjects. Furthermore, single-nucleotide polymorphisms (SNPs) of the adiponectin gene have been associated with metabolic phenotypes. The present study investigated whether the adiponectin gene promoter variant -11391 G/A (rs17300539) could predict the risk of developing traits characterizing the metabolic syndrome (MetS) and the impact of weight management. The -11391 G/A SNP was genotyped in 180 Spanish volunteers (BMI: 31.4+/-3.2 kg/m (2); age: 35+/-5 years). Clinical measurements were determined at baseline, following an 8-week low-calorie diet (LCD), and at 32 and 60 weeks. At baseline, the GG genotype was associated with higher HOMA-IR, insulin and triacylglyceride concentrations than other genotypes (p<0.05) and was also related with a higher risk of insulin resistance (OR: 2.437, p=0.025) and MetS clinical manifestations (OR: 3.236, p=0.003). Following the LCD, the increased risk in GG subjects compared with others disappeared (p>0.05). By 32 weeks after dietary therapy (n=84), GG carriers had recovered the risk of metabolic comorbidities (OR: 2.420, p=0.043). This risk was even more evident after 60 weeks (OR: 2.875, p=0.014). These data show an increased risk of insulin resistance and MetS complications in obese subjects of the -11391 GG genotype. The risk was markedly reduced during an energy-restricted diet, but was not sustained. Carriage of the A allele therefore confers protection from weight regain, and the effect is particularly evident 32-60 weeks after the dietary intervention, when improvement in GG subjects had disappeared.

G allele of the -930A>G polymorphism of the CYBA gene is associated with insulin resistance in obese subjects

It has been shown that NADPH oxidase plays a role in oxidative stress which has been involved in the development of metabolic syndrome. The -930A/G polymorphism of the CYBA gene (that codes p22phox, a major component of the NADPH oxidase) has been associated with human hypertension and with a reduction in NADPH oxidase activity. In this work, we have examined the influence of the -930A/G polymorphism on obesity risk and insulin resistance in a case-control study of Spanish subjects (n=313). In the obese group (n=159), there was a statistically significant association between the GG genotype of the -930A/G polymorphism of the CYBA gene and fasting insulin levels and HOMA index. This outcome agrees with previous findings concerning functional analyses of this polymorphism and reinforces the hypothesis that insulin resistance is associated with oxidative stress. In conclusion, a protective effect in carriers of the -930A/G polymorphism of the p22phox gene against insulin resistance in a population of Spanish obese adults has been found.

Vitamin C supplementation influences body fat mass and steroidogenesis-related genes when fed a high-fat diet

An enhanced oxidative stress status has been documented in obese patients and animal models, and a depletion of the antioxidant mechanisms in these conditions is a common feature. Therefore, we have tested the hypothesis that food supplementation with an antioxidant molecule such as vitamin C could prevent fat deposition induced by a high-fat diet in rodents. Ascorbic acid dietary supplementation reduced body weight and the retroperitoneal and subcutaneous fat depots in cafeteria diet-induced obese rats, without affecting food intake. Microarray technology has been applied in rat subcutaneous fat to assess the molecular mechanisms underlying the depletion of fat stores induced by ascorbic acid. Thus, expression of genes involved in cell proliferation, regulation of transcription, and host response are upregulated while a number of genes participating in lipid metabolism, cell adhesion, differentiation, and steroidogenesis (such as steroidogenic acute regulatory protein and hydroxysteroid 11-beta dehydrogenase 2) are downregulated. These data provide new insights to understand that not only calories count in weight gain, but also that the antioxidant status and other mechanisms affecting energy conversion efficiency could participate in energy homeostasis, in which glucocorticoids could be involved.

Selenium intake reduces serum C3, an early marker of metabolic syndrome manifestations, in healthy young adults

OBJECTIVES

To evaluate the associations between serum complement factor 3 (C3) and several anthropometrical, biochemical and lifestyle features in healthy young adults, emphasizing on the putative effect of selenium intake on C3 concentrations.

METHODS

This study enrolled 100 healthy young adults aged 18-34 years. Anthropometric and blood pressure measurements and lifestyle features were analyzed. Fasting blood samples were collected for the measurement of glucose, total cholesterol, HDL-cholesterol, LDL-cholesterol, triacylglycerols and C3 concentrations. Nail samples were collected for the analysis of selenium concentrations.

RESULTS

Values of BMI (P=0.034), sum of skinfold thicknesses (STs) (P=0.021), body fat mass (BFM) (P=0.023), percentage of overweight subjects (P=0.007), serum triacylglycerols (P=0.012) and nail selenium (P=0.001) were significantly different between subjects above and below the median of serum C3 concentrations. The following correlations with serum C3 were identified tricipital ST (P=0.033), sum of STs (P=0.012), BMI (P=0.008), BFM (P=0.018), waist-to-height ratio (P=0.016), serum glucose (P=0.045), serum triacylglycerols (P=0.001) and nail selenium (P=0.006). Circulating C3 showed a positive association with several adiposity markers such as BMI (P=0.001), waist circumference (P=0.006), waist-to-height ratio (P=0.002), BFM (P=0.025), as well as serum glucose (P=0.027) and triacylglycerols (P<0.001), whereas nail selenium was a statistically significant negative predictor of C3 concentrations (P=0.018).

CONCLUSIONS

C3 seems to be related with selenium status and several anthropometrical and biochemical measurements linked to metabolic syndrome in apparently healthy young adults. These findings suggest a possible role for selenium intake in the modulation of C3, whose assessment may be an early marker of metabolic syndrome manifestations.

Sirtuin gene expression in human mononuclear cells is modulated by caloric restriction

BACKGROUND

Sirtuins may provide novel targets for treating some diseases associated with oxidative stress, such as obesity and its comorbidities. However, there are a few in vivo studies in humans about the potential role of sirtuins as therapeutic targets among obese patients undergoing caloric restriction. Therefore, the aim of this study was to assess if the gene expression of sirtuins is modulated in peripheral blood mononuclear cells (PBMC) by a hypocaloric diet devised to lose weight in humans.

MATERIALS AND METHODS

Gene expression of two sirtuins (SIRT1 and SIRT2) in the PBMC of obese subjects (32.3 +/- 5.5 kg m(-2)) before and following an 8-week hypocaloric diet was investigated. NADH-coenzyme Q reductase (NDUFS2) and cytochrome c oxidase assembly protein (COX15) gene expression was selected together with plasma antioxidant power and nitric oxide as markers of antioxidant status. A quantitative real-time polymerase chain reaction approach was performed to assess the nutrigenomics outcome. Moreover, 2-keto[1-(13)C]isocaproate breath test (KICA-BT) parameters were evaluated to study mitochondrial oxidation in vivo.

RESULTS

The intervention up-regulated the expression of both sirtuins, being inversely associated with total antioxidant capacity and directly related to nitric oxide, mitochondrial oxidation assessed by the KICA-BT and the expression of the mitochondrial proteins COX15 and NDUFS2.

CONCLUSION

SIRT1 and SIRT2 may serve as key regulators for some obesity comorbidities related to antioxidant status, while PBMC could be a model to study the effect of the sirtuin response in obesity therapy.

[Methicillin-resistant Staphylococcus aureus bacteremia. Predictor factors for an isolate with a vancomycin minimal inhibitory concentration > or =2 mg/l]

A greater rate of treatment failures with vancomycin in methicillin-resistant Staphylococcus aureus (MRSA) bacteremia has been reported recently when the minimum inhibitory concentration (MIC) is > or =2 mg/l. This study has aimed to evaluate if there are clinical and/or epidemiological factors that predict isolation of a MRSA strain with MIC of vancomycin of > or =2 mg/L in the bacteremia episodes collected during a 15 year period (January 1991 to December 2005) in a tertiary urban hospital. During the study period, a total of 478 episodes of MRSA bacteremia were studied prospectively. The following clinical variables were recorded for each one: age, gender, comorbidity, previous administration of vancomycin or another antibiotic, prognosis of baseline diseases, bacteremia focus, shock, empiric antibiotic received and mortality. The MIC of vancomycin of 419 strains (88%) was determined with the E-test. In 216 (52%) of the isolations the MIC of vancomycin was 1.50 mg/L, in 110 (26%) of the cases it was < or =1 mg/l and in 93 (22%) 2 mg/l. Uni-and multivariate analyses were made, comparing the clinical variables of the patients infected by strains with MIC of vancomycin > or =2 mg/l regarding the MIC strains < or =1 mg/l. In the last 3 years of the study (2003-2005) the proportion of the strains with MIC of vancomycin > or =2 mg/l was significantly greater than those isolated with MIC < or = 1 mg/L (44 % vs 3 %; p<0.001). In the multivariate analysis, the only clinical characteristic associated independently to the isolation of a strain with MIC > or =2 mg/l was the nosocomial-acquired infection OR (95 % CI): 1.94 (1.04-3.63); p=0.04. Although the isolation of a MRSA strain with MIC of vancomycin > or =2 mg/l is more frequent in the nosocomial-acquired bacteremia episodes, in the clinical practice, it is not a useful predictive parameter because the frequency of isolation of these strains in the community is also high.

Treatment of obesity in children and adolescents. How nutrition can work?

Overweight appears when persistent positive energy imbalances occur for long periods of time. Knowledge of dietary risk factors during childhood and adolescence is needed in order to design preventive measures against the increase in the prevalence of obesity and its consequences but is, however, largely missing. Longitudinal studies in children have not found clear causal associations between energy intake or diet composition and overweight development. Research has been ongoing to develop effective intervention studies for obese children but it is not clear which intervention is the most effective in assisting overweight/obese children to improve body composition without affecting growth rates. The objective of this article is to review the available knowledge on dietary risk factors for the development of childhood obesity, to discuss different dietary treatment strategies, and to propose an evidence-based approach to treat obese adolescents.

[Validity of self-reported body mass index in the National Health Survey]

OBJECTIVE

To assess the validity of self-reported body mass index in the National Health Survey.

METHODS

120 participants were selected and questioned about their weight and height with exactly the same questions that the National Health Survey uses. Afterwards, and once informed consent was obtained, participants were weighed and measured, and this data was used as the gold standard.

RESULTS

On average, participants underestimated their weight by 1.39 kg, overestimated their height by 0.55 cm and underestimated their body mass index by 0.71 kg/m2. The sensitivity of self-reported self reported body mass index (BMI) to detect overweight was 77%, the specificity was 97%, the positive predictive value was 0.95 and the negative predictive value was 0.86. The Kappa index was 0.76 and the quadratically weighted Kappa index was 0.85. The correlation coefficient between self-reported and measured BMI was 0.96 and the intra-class correlation coefficient was 0.97.

CONCLUSIONS

Self-reported data is an efficient way of obtaining information about BMI, although with limitations, because self-reported data tends to underestimate weight and overestimate height, thus underestimating BMI and the proportion of participants with elevated BMI.

Phenotypical differences among B. cinerea isolates from ornamental plants

B. cinerea is a common pathogenic fungus which causes Botrytis blight (Grey mould) in most ornamental plants. It may be responsible for serious preharvest diseases and postharvest losses in fruits, vegetables and flowers. In this work, several B. cinerea isolates from ornamental plants (Chamelaucium uncinatum, Pelargonium x hortorum, Euphorbia pulcherrima, Lantana camara, Lonicera japonica, Hydrangea macrophylla, and Cyclamen persicum) affected by Botrytis blight in the south of Spain were studied. All the isolates were confirmed as B. cinerea by PCR using a specific 750-bp molecular marker, which is present in all strains of this species but absent from other species of Botrytis. The isolates were evaluated by reference to mature conidia length, sclerotia production, and growth rate. Conidia, conidiophores and hyphae were described by light microscopy and some by cryogenic scanning electron microscopy (Cryo-SEM). Conidium length was measured by using an eyepiece micrometer at 400x power, whereas the growth rate was assessed from differences in colony diameter between the third and fourth day of growth in potato-dextrose agar culture medium at 26 degrees C. B. cinerea showed a high degree of phenotypical variability among isolates, not only as regards visual aspects of the colonies but also in some morphological structures such as conidium length, conidiophores, sclerotia production, and hyphae. Differences were also observed in the growth rates. Conidiation was insignificant in the isolates from H. macrophylla, and P. x hortorum, where the overall appearance was white in all the growing stages, whereas isolates from L. camara, C. persicum and C. uncinatum were mainly grey or brown in mature stages. The longest conidia were obtained in isolates from H. macrophylla and C. persicum (17-18 microm) and the lowest in C. uncinatum (9 microm). All the isolates, except L. camara, developed mature sclerotia after approximately 16 days in the conditions used. H. macrophylla had around 72 sclerotia per colony, whereas C. persicum had only nine after 28 days. The growth rate of isolates from L. camara was the highest (1.64 cm/day). Such phenotypical variability may result in a differential response to plant growth regulators if plants are infected by Botrytis in the early stages of growth. In this way, we confirm, as we have done in other published studies, that isolates show different responses to some plant hormones and inhibitors.

Decreasing gradient of antibiotic concentration in the lumen of catheters locked with vancomycin

The purpose of this study was to investigate if vancomycin concentration is maintained along the lumen of dialysis catheters after 48 h of lock therapy. Each lumen of nine catheters (three subclavian and six femoral) was locked with 2,500 mg/l of vancomycin for 48 h. After that period, the content of the lumen was aspirated with three different syringes of 0.4 ml each to measure the proximal, medial and distal vancomycin concentration. Vancomycin concentration was measured using a homogeneous particle-enhanced turbidimetric inhibition immunoassay. A non-parametric ANOVA, by means of a rank transformation on the antibiotic concentration, was used to assess the influence of the catheter segment (proximal, medial and distal) and the catheter type (femoral or subclavian). A significant decrease in vancomycin concentration from proximal to distal segments was observed (p < 0.001). In addition, the vancomycin concentration in subclavian catheters was significantly higher than in femoral catheters (p < 0.001). In our study there was a decreasing gradient in vancomycin concentration from proximal to distal segments of the catheter. This may explain the failure of antibiotic lock-therapy.

[Inflammatory biomarkers: the link between obesity and associated pathologies]

[corrected] of this article is to review biomarkers that have been suggested in recent years as the link between inflammation, obesity and associated co-morbidities, as well as some questions that yet remain unclear. Increasing evidence indicates the important role of inflammation in the etiology of major public health problems. In the last years, several studies have proposed that obesity might be a inflammatory disorder. In addition, oxidative stress has been suggested as a potential inductor of inflammatory status and susceptibility to obesity and related disorders. Several biomarkers are being suggested as the link between obesity, insulin resistance, cardiovascular disease and metabolic syndrome, such as tumor necrosis factor alfa, interleukin-6 and -18, angiotensinogen, transforming grow factor beta, plasminogen activator inhibitor-1, leptin, resistin, C-reactive protein, serum amyloid A, sialic acid, fibrinogen, markers of endothelial dysfunction (von Willebrand factor, ICAMs, VCAMs), complement factor 3, haptoglobin, Zinc-alpha2-glycoprotein, eotaxin, visfatin, apelin, alpha1-antitrypsin, vaspin, omentin, retinol binding protein 4, ceruloplasmin, adiponectin and desnutrin. Some of this biomarkers are good predictors of cardiovascular risk (plasminogen activator inhibitor-1, sialic acid, fribrinogen, complement factor 3, C-reactive protein), adiposity (leptin, visfatin, resistin, haptoglobin) and/or insulin resistance (sialic acid, C-reactive protein, plasminogen activator inhibitor-1, von Willebrand factor). However, it is currently unclear the role of many of them concerning inflammatory processes in humans, as well as the factors involved in their regulation.

Mitochondrial oxidative stress and inflammation: an slalom to obesity and insulin resistance

Mitochondria, in addition to energy transformation, play a role in important metabolic tasks such as apoptosis, cellular proliferation, heme/steroid synthesis as well as in the cellular redox state regulation. The mitochondrial phosphorylation process is very efficient, but a small percentage of electrons may prematurely reduce oxygen forming toxic free radicals potentially impairing the mitochondria function. Furthermore, under certain conditions, protons can reenter the mitochondrial matrix through different uncoupling proteins (UCPs), affecting the control of free radicals production by mitochondria. Disorders of the mitochondrial electron transport chain, overgeneration of reactive oxygen species (ROS) and lipoperoxides or impairments in antioxidant defenses have been reported in situations of obesity and type-2 diabetes. On the other hand, obesity has been associated to a low degree pro-inflammatory state, in which impairments in the oxidative stress and antioxidant mechanism could be involved. Indeed, reactive oxygen species have been attributed a causal role in multiple forms of insulin resistance. The scientific evidence highlights the importance of investigating the relationships between oxidative stress and inflammation with obesity/diabetes onset and underlines the need to study in mitochondria from different tissues, the interactions of such factors either as a cause or consequence of obesity and insulin resistance.

Linoleic acid decreases leptin and adiponectin secretion from primary rat adipocytes in the presence of insulin

Obesity rates have dramatically increased over the last few decades and, at the same time, major changes in the type of fatty acid intake have occurred. Linoleic acid, an n-6 polyunsaturated fatty acid, is an essential fatty acid occurring in high amounts in several western diets. A potential role of this fatty acid on obesity has been suggested. Controversial effects of linoleic acid on insulin sensitivity have also been reported. Thus, the aim of this study was to examine the direct effects of linoleic acid on leptin and adiponectin production, two adipokines known to influence weight gain and insulin sensitivity. Because insulin-stimulated glucose metabolism is an important regulator of leptin production, the effects of linoleic acid on adipocyte metabolism were also examined. For this purpose, isolated rat adipocytes were incubated with linoleic acid (1-200 microM) in the absence or presence of insulin. Linoleic acid (1-200 microM) significantly decreased insulin-stimulated leptin secretion and expression (P < 0.05), however, no changes in basal leptin production were observed. Linoleic acid also induced a significant decrease (approximately 20%) in adiponectin secretion (P < 0.05), but only in the presence of insulin and at the highest concentration tested (200 microM). This fatty acid did not modify either glucose uptake or lactate production and the percentage of glucose metabolized to lactate was not changed either. Together, these results suggest that linoleic acid seems to interfere with other insulin signalling pathway different from those controlling glucose uptake and metabolism, but involved in the regulation of leptin and adiponectin production.

[Efficiency and mitochondrial metabolism: an etiological axis for obesity?]

Obesity, an increasing prevalent disease, appears as a consequence of an energetic umbalance that might be related to the efficiency of the cellular energetic machinery involving the mitochondria. In this organelle takes place the oxidative phosphorylation, that ends with the transformation of the nutrients to energy and the ATP production. During this process, free radicals of high oxidative power maybe blocked by endogenous antioxidants like the glutathion, in collaboration with the contribution of antioxidants supplied by the diet. The discovery of mitochondrial uncoupling proteins (UCPs) opened a new field of investigation, emphasizing the role of UCP1 or thermogenin, which generates an energy dissipation as heat and diminishing the amount of formed ATP and ROS and forcing the cell that expresses the UCP1 to oxidize more nutrients to obtain energy. Also, genetic studies have been carried out about UCP2 and UCP3 polymorphisms that relate them to obesity.

Microbial and clinical determinants of time-to-positivity in patients with bacteraemia

Time-to-positivity is useful in the diagnosis of catheter-related bacteraemia and as a predictor of an endovascular source in patients with Staphylococcus aureus bacteraemia. However, this parameter has been evaluated for only a limited number of microorganisms. In the present study, time-to-positivity was recorded for 1872 episodes of significant monomicrobial bacteraemia diagnosed at a teaching hospital during a 2-year period, and the associated microbial and clinical variables were investigated. According to multivariate analysis, Streptococcus pneumoniae, beta-haemolytic streptococci, Escherichia coli, Klebsiella, Enterobacter, Citrobacter and Aeromonas were characterised by fast growth, with an endovascular source, shock, liver cirrhosis and neutropenia also predicting a short time-to-positivity. For patients not receiving appropriate antibiotics, detection of Gram-positive cocci in clusters within 14 h was predictive of Staph. aureus; a time-to-positivity of >21 h ruled out the possibility that a Gram-positive organism in chains was a beta-haemolytic streptococcus or Strep. pneumoniae, and a time-to-positivity of < or =12 h meant that it was very unlikely that a Gram-negative bacillus was a non-fermenter. A time-to-positivity of < or =8 h was predictive of a non-urinary tract source in patients with E. coli bacteraemia, and detection of growth within 13 h predicted an endovascular source in those with Staph. aureus bacteraemia. In conclusion, time-to-positivity depended on the microorganism, original source and clinical variables involved. Although this measurement may provide some early clues concerning the microorganisms involved and the source of bacteraemia, its clinical impact remains to be defined.

Sp1-mediated transcription is involved in the induction of leptin by insulin-stimulated glucose metabolism

We have previously demonstrated that insulin-stimulated glucose metabolism, and not insulin per se, mediates the effects of insulin to increase the transcriptional activity of the leptin promoter in adipocytes. Here, we sought to identify the specific cis-acting DNA elements required for the upregulation of leptin gene transcription in response to insulin-mediated glucose metabolism. To accomplish this, 3T3-L1 cells and primary rat adipocytes were transfected with a series of luciferase reporter genes containing portions of the mouse leptin promoter. Using this method, we identified an element between -135 and -95 bp (relative to the transcriptional start site) that mediated transcription in response to insulin-stimulated glucose metabolism in adipocytes. This effect was abolished by incubation with 2-deoxy-d-glucose, a competitive inhibitor of glucose metabolism. Gel shift electrophoretic mobility shift assays confirmed that the stimulatory effect of insulin-mediated glucose metabolism on leptin transcription was mediated by a previously identified Sp1 site. Consistent with these findings, incubation of primary rat adipocytes with WP631, a specific inhibitor of specificity protein (Sp)1-dependent transcription, inhibited glucose- and insulin-stimulated, but not basal, leptin secretion. Together, these findings support a key role for Sp1 in the transcriptional activation of the leptin gene promoter by insulin-mediated glucose metabolism.

A novel mutation Thr162Arg of the melanocortin 4 receptor gene in a Spanish children and adolescent population

OBJECTIVE

The melanocortin 4 receptor gene (MC4R) is involved in body weight regulation. While many studies associated MC4R mutations with childhood obesity, information on MC4R mutations in Spanish children and adolescents is lacking. Our objective was to screen a population of children and adolescents from the north of Spain (Navarra) for MC4R mutations and to study the phenotypes of carriers and their families. In addition, functional assays were performed for a novel MC4R mutation.

METHODS

The study was composed of 451 Spanish children and adolescents (49% boys), aged 5-18 year. According to the International Obesity Task Force (IOTF) criteria, the groups included 160 obese, 132 overweight and 159 normal-weight control subjects.

RESULTS

One novel (Thr162Arg) and three known nonsynonymous mutations in the MC4R gene (Ser30Phe, Thr150Ile, Ala244Glu) were detected heterozygously. The MC4R mutations were found in three male (one obese and two overweight) and two female subjects (one obese and one overweight). The novel mutation did not appear to lead to an impaired receptor function. An unequivocal relationship of MC4R mutations with obesity in pedigrees together with an impaired function of the encoded receptor could not be established for any of the mutations.

CONCLUSIONS

The presence of heterozygous MC4R mutations in obese and overweight subjects indicates that these mutations may be a susceptibility factor for obesity development, but lifestyle factors, such as exercise or sedentary activities, may modify their effect.

Usefulness of teicoplanin for preventing methicillin-resistant Staphylococcus aureus infections in orthopedic surgery

In order to gather more data on the use of teicoplanin for reducing MRSA infections in high-risk populations, the present study was conducted. At a hospital in Barcelona, Spain, there was a high prevalence of MRSA infections among patients who underwent surgery for femoral neck fracture during the first 5 months of 2002 (period A) when cefuroxime was the antibiotic prophylaxis. During the following 12 months (period B) 600 mg of teicoplanin was added to cefuroxime. The rates of overall and MRSA infection during period A were 5.07 and 2.73%, respectively. Pulsed-field gel electrophoresis demonstrated there was no clonal relationship among MRSA strains. No nasal carriers of MRSA were detected among health workers. During period B the rates of overall and MRSA infection were 2.36 and 0.19%, respectively. Both rates were statistically significantly lower than those in period A (p<0.05). These results suggest teicoplanin may be useful in patients undergoing orthopedic surgery when the prevalence of MRSA is high.

Conjugated linoleic acid inhibits glucose metabolism, leptin and adiponectin secretion in primary cultured rat adipocytes

Conjugated linoleic acid (CLA) supplementation has been reported to induce insulin resistance in animals and humans, however, the underlying mechanisms remain unclear. The aim of this study was to examine the direct effects of CLA on leptin and adiponectin secretion, two hormones with actions known to influence insulin sensitivity. Isolated rat adipocytes were incubated with CLA (1-200microM) in the absence and presence of insulin (1.6nM). CLA inhibited both basal and insulin-stimulated leptin gene expression and secretion (-30 to -40%, P<0.05-0.01). CLA also inhibited basal adiponectin production (-20 to -40%, P<0.05-0.01), but not in the presence of insulin. CLA (50-200muM) decreased basal glucose uptake (P<0.05-0.01) and significantly increased the proportion of glucose metabolized to lactate (P<0.01). Insulin treatment partially prevented the inhibitory effects of CLA on glucose uptake and induced a significant increase (P<0.05-0.01) in the percentage of glucose metabolized to lactate. A strong inverse relationship was observed between the increase in the anaerobic utilization of glucose and the decreases of both leptin and adiponectin secretion. In addition, lipolysis and the expression of the adipogenic transcription factor PPARgamma were decreased by CLA. These results indicate that CLA inhibits leptin and adiponectin secretion and suggest that increased anaerobic metabolism of glucose may be involved in these effects. The inhibition of PPARgamma could also mediate the inhibition of adiponectin induced by CLA. Furthermore, the inhibition of leptin and adiponectin production induced by CLA may contribute to insulin resistance observed in CLA-treated animals and humans.

Treatment of acute post-surgical infection of joint arthroplasty

The best antibiotic regimen for acute prosthetic joint infection, treated without removal of the implant, has not been well-defined. This study describes the use of a protocol based on oral rifampicin combinations to treat 47 cases that were followed prospectively for a 2-year period. The regimen used most commonly was levofloxacin 500 mg/24 h plus rifampicin 600 mg/24 h for a mean duration of 2.7 +/- 1 months. The cure rate was 76.9%, and the only independent risk-factor associated with treatment failure was infection caused by methicillin-resistant Staphylococcus aureus or Enterococcus spp. (OR 17.6, p 0.003). Overall, the results suggested that use of oral antibiotics, including rifampicin, for 2-3 months was a good treatment option.

Differences in short-term metabolic responses to a lipid load in lean (resistant) vs obese (susceptible) young male subjects with habitual high-fat consumption

OBJECTIVE

To determine the role of macronutrients oxidation ability in the postprandial response to a high lipid load in the mechanisms conferring resistance or susceptibility to obesity.

SUBJECTS AND DESIGN

Nine lean and nine obese young male subjects with habitual similar high-fat intake (>40 % of energy) and comparable physical activity were selected and categorized as 'resistant', those who remained lean (body mass index (BMI) <25 kg/m2), and 'susceptible', those who were obese (BMI>30 kg/m2). Fasting blood samples were taken for the evaluation of blood metabolic and hormonal variables. Resting metabolic rate (RMR) and substrates oxidation were measured by indirect calorimetry, in the fasting state and every 30 min for 3 h after a rich lipid meal (fat 94.7%) supplied to cover the 50% of the volunteers energy requirements. The study was performed at the Metabolic Unit of the University of Navarra.

RESULTS

Fasting RMR and lipid oxidation were higher in obese-susceptible subjects. However, similar values were found in both groups after adjustment for fat mass and free fat mass. The cumulative postprandial fat oxidation was also similar in both groups (despite having different tissue metabolic activity), whereas cumulative carbohydrate oxidation was lower in the obese-susceptible group. The thermic effect of food (% of dietary induced thermogenesis) was lower (P<0.05) in the susceptible-obese subjects. The energy and fat balance were more positive in the obesity-susceptible individuals after the high fat load, who also showed higher fasting homeostatic model assessment index, low-density lipoprotein-cholesterol and triacylglyceride levels, hyperleptinemia and hypoadiponectinemia.

CONCLUSION

Lean-resistant individuals came closer to achieving fat balance than obese-susceptible subjects. These metabolic and hormonal differences are probably genetically determined.

The nucleus tractus solitari (NTS) participates in peripheral ghrelin glucostatic hunger signalling mediated by insulin

Three extrahypothalamic areas, the nucleus of the tractus solitari (NTS), the central nucleus of the amygdala (CeA) and the dorsal raphe nucleus (DRN), all potentially involved in peripheral ghrelin signalling of appetite control mediated by the glucose levels were examined. Thus, a specific anti-ghrelin antibody (AGA) was intravenously administered in order to remove the ghrelin signalling and then, subsequently, 4-h food intake, plasma glucose levels and the brain c-fos expression in the NTS, CeA and DRN were assessed. Food intake significantly decreased when the AGA was administered. NTS c-Fos expression was significantly augmented by insulin, while it was significantly decreased by the AGA. These results suggest that the NTS is a part of the ghrelin pathway that regulates the orexigenic signalling cascade, which may be triggered by a drop in blood glucose levels mediated by insulin.

Effects of eicosapentaenoic acid (EPA) on adiponectin gene expression and secretion in primary cultured rat adipocytes

Adiponectin, a hormone produced by adipocytes, is involved in glucose metabolism and insulin sensitivity. The production of this adipokine is impaired in obesity and insulin resistance. Eicosapentaenoic acid (EPA) is a dietary n-3 polyunsaturated fatty acid that improves insulin sensitivity in several models of obesity and diabetes, which has been suggested to be related to adiponectin induction. An increase in adiponectin production has been also associated with an up-regulation of the transcriptional factor PPARgamma. The aim of this trial was to evaluate the direct effects of EPA on adiponectin gene expression and protein secretion in isolated rat adipocytes as well as to explore the potential mechanisms involved. A comparative study with troglitazone, a PPARgamma agonist, was also performed. For these purposes, primary rat adipocytes were cultured with EPA (100 and 200 microM) and with troglitazone (10 microM) for 96 hours. Both EPA and troglitazone improved glucose utilization by adipocytes. As expected, troglitazone enhanced adiponectin secretion and increased PPARgamma gene expression. However, EPA significantly decreased adiponectin gene expression and protein secretion and reduced PPARy mRNA levels, suggesting that the inhibition of adiponectin by EPA is likely to be secondary to the down-regulation of this adipogenic transcription factor. Moreover, these results suggest that other mechanisms different from the direct stimulation of adiponectin by the fatty acid are underlying the insulin-sensitizing properties observed after EPA treatment in vivo.

Diferential gene expression and adiposity reduction induced by ascorbic acid supplementation in a cafeteria model of obesity

Obesity is considered as an inflammatory disease, in which free radical-induced oxidative stress and excessive intake of macronutrients exacerbate their symptoms. In this context, we assessed in rats the possible preventive effect of the supplementation with an antioxidant molecule, ascorbic acid, in order to reduce the adiposity induced by the intake of a high-fat diet. For this purpose, during 56 days, three groups of male Wistar rats were fed on: a) standard pelleted diet, b) Cafeteria diet, c) ascorbate-supplemented (750 mg/kg of body weight) Cafeteria diet. At the end of the experimental period, microarray analysis was used to identify genes transcriptionally induced or repressed by both experimental dietary models (Cafeteria diet supplemented or not with ascorbic acid) in subcutaneous adipose tissue. Dietary ascorbic acid was able to protect against high fat diet effects, reducing the increase of body weight, total body fat and enlargement of different adipose depots induced by the Cafeteria diet without affecting food intake. An association analysis accurately and differentially allowed the detection of gene expression changes related with adiposity and insulin resistance. The genes that more strongly correlated with body fat and HOMA insulin resistance index were involved in adipocyte differentiation, lipid and glucocorticoid metabolism, cell cycle regulation, as well as in several insulin-induced processes. Some other transcripts are regulated by the vitamin C-mediated reduction of adiposity, such as genes that participate in glucocorticoid metabolism, adipogenesis, pentose phosphate pathway, or tricarboxylic acid cycle. This strategy was able to link variations in adipose tissue gene expression with markers of diet-induced obesity in rats, such as insulin resistance and body fat content.

Prospective evaluation of procalcitonin in adults with non-neutropenic fever after allogeneic hematopoietic stem cell transplantation

The aim of this study was to analyze whether procalcitonin (PCT) is a diagnostic marker of infectious diseases during the non-neutropenic period in patients who have received an allogeneic hematopoietic stem cell transplant (HSCT). We included 65 patients in whom an allogeneic HSCT was performed in a 2-year period (April 2002-July 2004). PCT levels were monitored in every febrile episode by an immunoluminometric assay. Febrile episodes were classified according to the final diagnosis in: fever of unknown origin, microbiologically or clinically documented infection and non-infectious fever. Fifty-two febrile episodes in the non-neutropenic period were included in the study. Out of these 52, 26 had an infectious etiology: 11 fulfilled criteria for probable or proven invasive aspergillosis (IA), three were classified as possible invasive fungal infection (IFI) and 12 episodes were caused by other infections. Mean values of PCT on the first day of admission were: 8.0 (+/- 4.9) in probable-proven IA (P = 0.013, Kruskall-Wallis), 4.5 (+/- 3.4) in possible IFI and 1.5 (+/- 0.9) in infections other than IFI. Therefore, we could conclude that during the non-neutropenic phases of allogeneic HSCT, a high PCT value is associated significantly with IA.

Inflammation and conjugated linoleic acid: mechanisms of action and implications for human health

Data from a number of studies and trials have shown that different conjugated linoleic acids (CLA's) may produce beneficial effects on cancer, atherosclerosis, hypertension, diabetes and changes in body composition. Despite the increasing knowledge about CLA's implications on health, the mechanism of action of these fatty acids is not completely understood. Moreover, human studies indicate that some of these beneficial effects are considerably less evident than anticipated from mice studies, while the efficacy and safety of dietary supplements containing CLA have been questioned in some intervention trials. Recently, it has been suggested that the anti-carcinogenic and anti-atherosclerosis effects of CLA's stem from its anti-inflammatory properties. Because inflammatory responses are associated with the pathophysiology of many diseases, including obesity and the metabolic syndrome, the investigation in this area is of growing interest in recent years.

Bacteremia and septic shock after solid-organ transplantation

BACKGROUND

Bacteremia and septic shock remain important causes of morbidity and mortality after solid-organ transplantation. The aim of this study was to assess the characteristics and risk factors for mortality among patients with bloodstream infections and shock.

METHODS

From January 1991 to December 2000, all episodes of bloodstream infection were prospectively examined, considering bacteremia or fungemia as significant according to the CDC criteria. Septic shock was diagnosed in a patient with systemic inflammatory response syndrome and persistent dysfunction of at least one organ caused by hypoperfusion despite hemodynamic support.

RESULTS

There were 466 episodes of bacteremia in 382 patients, with 66 of them developing septic shock. Risk factors for developing shock were age >50 (P = .006), liver transplant (P = .029), nosocomial infection (P = .034), pulmonary focus (P = .0001), P. aeruginosa infection (P = .001), and polymicrobial etiology (P = .039). On multivariate analysis, only age, nosocomial infection, and pulmonary source were significant. Among 66 shock patients, bacteremia was due to gram-negative bacteria in 53%, gram-positive bacteria in 24%, fungal in 7.5%, and polymicrobial in 12% of patients. The most frequent source was the lung (26%). Empiric antimicrobial therapy was correctly chosen in 79%; however, 36 patients died (54%), including 27 despite correct therapy. Urinary tract infections had less mortality than other foci.

CONCLUSIONS

Risk factors for developing septic shock in bacteremia were age more than 50 years, nosocomial acquisition, and pulmonary focus. Despite adequate empiric antibiotic therapy, the mortality remained high.

TV watching modifies obesity risk linked to the 27Glu polymorphism of the ADRB2 gene in girls

OBJECTIVE

A matched case-control study was conducted in a population of Spanish children and adolescents (5-18 years old), to assess the interaction between the Gln27Glu polymorphism of the ADRB2 and television (TV) watching on obesity risk.

PATIENTS

Obese (n=165) and control subjects (n=165) matched by sex and age were recruited and classified according to Spanish reference data. Results. Using conditional logistic regression, we calculated the obesity risk linked to the polymorphism. A statistically significant association was found for 27Glu carrier allele girls (OR = 1.95; 95% CI = 1.02-3.70), but no association was apparent among boys. In the fully adjusted model, the odds ratio for obesity linked to the genotype Glu27Glu in the female population rose to 4.84 (95% CI = 1.37-17.10). Moreover, we found a significant negative interaction between hours of TV watching and the Gln27Glu polymorphism for obesity risk in girls. Surprisingly, among 27Glu carrier subjects, even girls with a low level of TV watching ( < 12.5 h/week) had a high obesity risk (OR = 4.60; 95% CI = 1.01-20.02), which was not very different to the odds ratio values for sedentary girls carrying the 27 Glu allele watching TV more than 12.5 h/week (OR = 6.05; 95% CI = 1.31-27.71). Conclusion. A higher risk of obesity was found for girls carrying the 27Glu allele of the ADRB2 gene even when they spent less than 12.5 h/week watching TV. In addition, our results suggest that the effect of sedentary lifestyle on obesity risk may depend on the genotype of the subject.

[Influence of the -866G/A polymorphism of the UCP2 gene on an obese pediatric population]

OBJECTIVE

In the present study, our objectives were to evaluate the prevalence of -866G/A mutation of UCP2 gene and to study its influence on the phenotype of obese children (11-12 years old) from Navarra. BACKGROUND AND STUDY SETTING: Obesity is a disease with a multifactorial origin that may related be to the presence of mutations and polymorphisms in several candidate genes. The gene of the uncoupling protein UCP2 is one of the most studied ones in relation to obesity because it seems to participate in body composition and several metabolic processes control. Three polymorphisms have been described for this gene: an insertion/deletion of 45 nucleotides, a nucleotide change of guanine for adenine in -866 position, an another change that replaces alanine for valine at amino acid position 55. According to several studies, the -866G allele is related to an increased risk of developing obesity, although the results are contradictory about this association in the literature.

SUBJECTS

The study was carried out on 125 obese children (52% male), aged 11-12 years, selected through the Pediatric Endocrinology Departments of Clínica Universitaria and Hospital Virgen del Camino of Pamplona (Spain), the reported results on this association are contradictory.

INTERVENTIONS

After checking the inclusion criteria, anthropometrical data (weight, height, BMI, tricipital and subscapular skinfolds) were taken, and the percentage of fat mass was measured by bioelectrical impedance. Besides, plasma levels of total cholesterol, glucose, insulin, and leptin were measured. DNA was extracted from white blood cells to determine the genotype by PCR technique followed by BstUI digestion and further visualization in agarose gel with 2% ethidium bromide.

RESULTS

The genetic analysis revealed a 0.404 frequency of the allele A, with a percentage of individuals G/G, G/A, and A/A of 40.0%, 39.2%, and 20.8%, respectively. Carriers of the A allele had a significantly higher sum of tricipital and subscapular folds (p = 0.034). No significant differences between mutant and non-mutant subjects with regard to the studied biochemical variables were observed.

CONCLUSIONS

Subjects carrying the polymorphism present higher values of tricipital and subscapular skinfolds as compared to non-mutant subjects, which may indicate a relationship between the presence of the A allele in obese children and higher amounts of subcutaneous fat.

Serum and gene expression levels of leptin and adiponectin in rats susceptible or resistant to diet-induced obesity

The aim of the present study was to identify the role of leptin and adiponectin in the development of resistance or susceptibility to diet-induced obesity in rats. For this purpose, male Wistar rats were fed with standard laboratory diet (control group) or cafeteria diet. After 15 days, two groups of rats with different response respect to the cafeteria diet were identified, and were assigned as diet-induced obesity (DIO) and diet resistant (DR) rats. The high-fat diet induced a very significant increase in both body and fat mass weight in DIO group. However, DR rats, gained even less weight than control-fed animals. Food intake was increased in cafeteria-fed rats (both DIO and DR) in comparison to control group; but hyperphagia was higher in DIO rats. In addition, feed efficiency (the ratio of weight gained to calories consumed) was significantly decreased in DR as compared to DIO rats. Regarding leptin, a significant increase in both adipose tissue gene expression and serum levels was observed in DIO rats in comparison with other groups (control and DR). A significant increase in both adiponectin circulating levels and adipose tissue mRNA expression was also observed in DIO animals as compared with the other groups. These data suggest that the susceptibility to obesity of DIO rats might be secondary, at least in part, to an earlier development of leptin resistance, which could lead to alterations in food intake (hyperphagia) and energetic metabolism. However, neither changes in leptin or adiponectin seem to be involved in the adaptive mechanisms that confer resistance to high fat intake.

Ectopic UCP1 gene expression in HepG2 cells affects ATP production

The UCP1 is an uncoupling protein located in the inner mitochondrial membrane of brown adipocytes, which has a well-documented role in diet-induced thermogenesis. The current study assessed whether UCP1 transfected liver cells demand more fuel substrates in the oxidative phosphorylation processes. Therefore, the purpose of this experiment was to achieve an ectopic expression of UCP1 in HepG2 cells to significantly decrease the production of ATP. The UCP1 gene was transferred into the hepatic cells by using a calcium phosphate precipitation protocol. The efficiency of the transfection was tested, 48 hours later, by bioluminescence of luciferase previously transfected, while the expression of mRNA of UCP1 was demonstrated by RT-PCR. In addition, measuring the production of ATP by using a bioluminescence procedure assessed the functionality of this protein. Transfected liver cells with UCP1 showed a decrease of 23% in ATP production in comparison with control cells without expression of UCP1 (2.23 vs. 2.90 RLU/pg protein, p=0.015). In conclusion, the ectopic expression of UCP1 decreased the production of ATP, possibly uncoupling the oxidative phosphorylation, which could be a novel approach for understanding thermogenic processes and eventually for energy metabolism and body weight management.

[Comparison between two methods to estimate physical activity in obese women: accelerometry and self-administered questionnaire]

The aims of this study were to describe a female obese population according to their food intake and physical activity, and to compare two methods to estimate physical activity (PA). The study included a nutritional interview where a detailed dietary history was done, an initial clinical day in which measurements of body composition and basal metabolic rate (BMR) were carried out and an estimation of PA by means of a triaxial accelerometer and a PA questionnaire. The group of volunteers showed a mean BMI of 37.15 kg/m2, a waist/hip ratio of 0.82 and a mean body fat mass of 43.34%. The average of BMR was 1720 Kcal/d and the CRNP of 0.79. The total caloric intake was 3344 Kcal/d with a energy-distribution of 43.1% Carbohydrates, 16.4% Proteins, 40.3% Lipids. Weight and BMI showed a positive correlation (p < 0.05) with the sedentary index (SI). Also, weight presented a positive correlation with the heart rate (p < 0.05). The estimates of PA derived from the questionnaire showed a positive correlation with the triaxial accelerometer (p < 0.01); and this one, revealed a negative correlation with the SI (p < 0.01). Anthropometric, metabolic and food intake variables are comparable to the results found in obese women from similar socioeconomic background. The estimates of PA according to the questionnaire were significantly correlated to the results of the triaxial accelerometer, thus confirming the validity of the questionnaire to assess PA in an obese population.

Decreased splenic mRNA expression levels of TNF-alpha and IL-6 in diet-induced obese animals

Obesity could be considered as a systemic low-grade inflammatory condition affecting inflammation markers. Adipose tissue synthesizes cytokines whose degree of elevation may depend on the obesity status. Recently, new information is collected on the cross-talking between immune system and adipose tissue in obesity. We report hereby that tumor necrosis factor alpha (TNF-alpha) and interleukin 6 (IL-6) gene expression in spleen of diet-induced obese animals were markedly decreased (more than 50%) as a consequence of the high fat feeding during five weeks. Interestingly, a very significant negative correlation was found between splenic TNF-alpha mRNA levels and total fat pads (r = -0.806, p = 0.000). These findings support the hypothesis that TNF-alpha gene expression may follow different trends in obese animals adipocytes and splenocytes.

[Advances in molecular nutrition: nutrigenomics and/or nutrigenetics]

The application of molecular biology techniques and the success of the Human Genome Project have opened a new era for both Medicine and Nutrition. To date, at least 1,000 human genes causing disease have been identified and partially characterized, 97% of which we now know that are the cause of monogenic diseases. However, other diseases such as obesity, cardiovascular disease, diabetes, and cancer are due to complex interactions between several genes and environmental factors. In spite of the many association studies, over 600 published since 2002, the molecular base of chronic diseases is still uncertain. Information about nucleotide polymorphisms and haplotypes maps is an additional resource for identifying genes implicated in diseases. Genomic development gets close, however we frequently do not accurately know the dietary components and their mechanisms that importantly influence on genetic information expression and its pathologic impairments. The food industry has the opportunity for utilizing the bioactive components of foods to improve health and prevent diseases while considering the consumers' genetic constitution. This new era of molecular nutrition--gene-nutrient interactions--may evolve in several ways, although two of them are essential. On the one hand, the study of the influence of nutrients on gene expression (nutrigenomics) and, on the other hand, to know the influence of genetic variations in the organism response to nutrients (nutrigenetics).

Does weight loss prognosis depend on genetic make-up?

The prevalence of obesity is rising throughout the world. Indeed, obesity has reached epidemic proportions in many developed and transition countries. Obesity is a complex disease with multifactorial origin, which in many cases appears as a polygenic condition affected by environmental factors. Treatment or prevention of obesity is necessary to reverse or avoid the onset of type 2 diabetes and other obesity-related diseases. Weight loss is a complex trait that depends on many environmental, behavioural and genetic influences. An effective programme for the management of overweight and obesity must take into account all of these factors. Individual responses to weight loss interventions vary widely and reliable predictors of successful slimming are poorly understood. The individual genetic make-up participating in energy expenditure regulation, appetite control, lipid metabolism and adipogenesis, have been reported to affect the risk of treatment failure in some subjects. In addition, the genotype could also help to predict the changes in lipid profile, cardiovascular risk factors and insulin sensitivity in response to weight loss. Herein, the current evidence from human studies that support the existence of a genetic component and the participation of different polymorphisms in the prognosis of weight loss induced by interventions leading to a negative energy balance are reviewed.

Gene-gene interaction between PPAR gamma 2 and ADR beta 3 increases obesity risk in children and adolescents

AIMS

Multiple genes are likely to be involved in obesity and these genes may interact with environmental factors to influence obesity risk. Our aim was to explore the synergistic contribution of the two polymorphisms: Pro12Ala of the PPAR gamma 2 gene and Trp64Arg of the ADR beta 3 gene to obesity risk in a Spanish children and adolescent population.

METHODS

We designed a sex- and age-matched case-control study. Participants were 185 obese and 185 control children (aged 5-18 y) from the Navarra region, recruited through Departments of Pediatrics (Hospital Virgen del Camino, Navarra University Clinic and several Primary Health Centers). The obesity criterion (case definition) was BMI above the 97th percentile according to Spanish BMI reference data for age and gender. Anthropometric parameters were measured by standard protocols. The genotype was assessed by PCR-RFLP after digestion with BstUI for PPAR gamma 2 mutation and BstNI for ADR beta 3 variants. Face-to-face interviews were conducted to assess the physical activity. Using a validated physical activity questionnaire, we computed an activity metabolic equivalent index (METs h/week), which represents the physical exercise during the week for each participant. Statistical analysis was performed by conditional logistic regression, taking into account the matching between cases and controls.

RESULTS

Carriers of the polymorphism Pro12Ala of the PPAR gamma 2 gene had a significantly higher obesity risk than noncarriers (odds ratio (OR)=2.18, 95% CI=1.09-4.36) when we adjusted for sex, age and physical activity. Moreover, the risk of obesity was higher (OR=2.59, 95% CI=1.17-5.34) when family history of obesity was also taken into account in the model. The OR for obesity linked to both polymorphisms (PPAR gamma 2 and ADR beta 3) was 5.30 (95% CI=1.08-25.97) when we adjusted for sex, age and physical activity. After adjustment for family history of obesity, the OR for carriers of both polymorphisms was 19.5 (95% CI=2.43-146.8).

CONCLUSIONS

A synergistic effect between polymorphism Pro12Ala of the PPAR gamma 2 gene and Trp64Arg of the ADR beta 3 gene for obesity risk was found in a case-control study including children and adolescents.

Genes, lifestyles and obesity

OBJECTIVE

To review the role of genes and lifestyle factors, particularly dietary habits and physical activity patterns, in obesity risk as well as their potential interactions.

DESIGN AND MEASUREMENTS

A descriptive report of a number of genes definitely ascribed or potentially implicated in excessive fat accumulation leading to obesity as assessed by different research approaches (Mendelian transmission, genetic animal models, epidemiological association/linkage studies and genome-wide scans). Also, the involvement of macronutrient intake and composition (fat/carbohydrate) as well as the role of activity-linked energy expenditure in obesity onset is reviewed.

RESULTS

Examples of the role of the genotype as well as of the dietary macronutrient composition/intake and sedentary/low energy cost of physical activities in obesity prevalence are reported.

CONCLUSIONS

Both genes and everyday life environmental factors such as cultural and social mediated food intake and reduced domestic and living work activities are involved in the obesity pandemia. The occurrence of gene x gene and gene x environmental factors interactions makes it more difficult to interpret the specific roles of genetics and lifestyle in obesity risk.

Lower mortality among patients with community-acquired pneumonia treated with a macrolide plus a beta-lactam agent versus a beta-lactam agent alone

A cohort of 1,391 patients with community-acquired pneumonia of unknown etiology, atypical pneumonia, Legionella pneumophila pneumonia, viral pneumonia, or pneumococcal pneumonia was studied according to a standard protocol to analyse whether the addition of a macrolide to beta-lactam empirical treatment decreases mortality rates. Patients admitted to the intensive care unit were excluded. Severity was assessed using the PORT score. An etiological diagnosis was achieved in 498 (35.8%) patients (292 infections due to Streptococcus pneumoniae). Treatment was chosen by the attending physician according to his/her own criteria: beta-lactam agent in 270 and beta-lactam agent plus a macrolide in 918 cases. The mortality rate was 13.3% in the group treated with a beta-lactam agent alone and 6.9% in the group treated with a beta-lactam agent plus a macrolide (p=0.001). The percentage of PORT-group V patients was 32.6% in the group treated with a beta-lactam agent alone compared to 25.7% in the group who received a beta-lactam agent plus a macrolide (p=0.02). After controlling for PORT score, the odds of fatal outcome was two times higher in patients treated with a beta-lactam agent alone than in those treated with a beta-lactam agent plus a macrolide (adjusted OR = 2, 95%CI 1.24-3.23). The results suggest that the addition of a macrolide to an initial beta-lactam-based antibiotic regimen is associated with lower mortality in patients with community-acquired pneumonia, independent of severity of infection, thus supporting the recommendation of a beta-lactam-agent plus a macrolide as empirical therapy.

Is the combination of pyrazinamide plus rifampicin safe for treating latent tuberculosis infection in persons not infected by the human immunodeficiency virus?

SETTING

Nine public health care centres in four Spanish cities.

OBJECTIVE

To evaluate the efficacy and safety of 2 months of rifampicin (R) plus pyrazinamide (Z) therapy (2RZ) compared with a 6-month course of isoniazid therapy (6H) for treating latent tuberculosis infection (LTBI).

DESIGN

Multicentered, randomised, comparative and prospective trial conducted in HIV-seronegative contacts of infectious pulmonary TB cases.

RESULTS

Of 352 individuals, 199 received 6H and 153 2RZ; 73% of contacts receiving 6H and 71% receiving 2RZ completed treatment (P = 0.73). Treatment interruption due to hepatotoxicity (ALT/AST > 5 times upper limit of normal) was observed in 10% of contacts in the 2RZ group and in 2.5% of the 6H group (P = 0.007). This higher than expected rate of hepatotoxicity in the 2RZ arm led to premature termination of the study. Severe or fatal liver injury was not detected. Liver function tests normalised after discontinuation of treatment. We conclude that the use of RZ should only be considered when other regimens are unsuitable and intensive monitoring of liver function is feasible.

Postprandial insulin response and mitochondrial oxidation in obese men nutritionally treated to lose weight

Obesity, hyperglycemia, and insulin resistance have been associated to an oxidative mitochondrial dysfunction. The aim of this research was to evaluate the relation between carbohydrate metabolism and mitochondrial oxidation, as affected by the weight status and the weight loss induced by a calorie-restricted diet. Lean control men (BMI<25 kg/m2, n = 6) and obese men (BMI>30 kg/m2, n = 14), who were characterized as insulin resistant (n = 6) or insulin sensitive (n = 8) based on HOMA index values, participated in the trial. Plasma insulin levels and mitochondrial oxidation estimated by the 2-keto(1-13C)isocaproate breath test, were measured after ingestion of a test meal during 3 h. Obese subjects repeated the breath test protocol after a 10-week caloric restriction diet to lose weight. Postprandial insulin secretion tended to be marginally higher (P = 0.059) in both obese groups than in controls, while the rate of postprandial mitochondrial oxidation was markedly decreased (P = 0.019) in the obese subjects as compared with lean individuals. The nutritionally induced weight loss produced a rise in the postprandial oxidative process in volunteers initially considered as insulin resistant (P = 0.036), while no statistical differences in the insulin-sensitive obese (P = 0.241) were found. Interestingly, the percentage of oxidized tracer was inversely related to postprandial insulin secretion (r = -0.56; P = 0.001). In conclusion, these results support the hypothetized relation between carbohydrate metabolism and mitochondrial oxidation at a postprandial state in obese subjects, raising interest about mitochondria stimulation as a target in the therapy of obesity.

Prevalence of obesity in Spain

Obesity is a health problem affecting an important proportion of the Spanish population. Overweight is more common among men than women whereas, obesity is more prevalent among women. The most recent data (2001) from self-reported weight and height measurements of a Spanish representative sample (21120 subjects) revealed that the overall obesity prevalence in Spain was about 13%, while direct anthropometric data obtained from pooled surveys concerning eight Spanish regions (9885 subjects), which were carried out between 1990-2000 the obesity prevalence averaged 14.5%.

Basal and postprandial substrate oxidation rates in obese women receiving two test meals with different protein content

BACKGROUND & AIMS

Fuel utilisation and storage in lean and obese subjects seem to be differently affected by the macronutrient distribution intake. The aim of this intervention study was to explore the extent to which the fat mass status and the macronutrient composition of an acute dietary intake influence substrate oxidation rates.

METHODS

Fuel utilisation in 26 women, 14 obese (BMI = 37.1 +/- 1.1 kg/m2) and 12 lean (BMI = 20.6 +/- 0.5 kg/m2) was measured over 6 h to compare the metabolic effect of a single balanced protein (HC) meal and a high protein (HP) single meal, which were designed to supply similar energy contents (1672 kJ). The macronutrient composition as a percentage of energy of the HC meal was 55% carbohydrate, 15% protein and 30% fat, while the HP meal contained 40% carbohydrate, 30% protein and 30% fat. Nutrient oxidation rates and energy expenditure were calculated by indirect calorimetry (hood system), whereas exogenous amino acid oxidation was estimated from the 13C isotopic enrichment of breath after oral administration of L[1-13C]leucine.

RESULTS

Fasting lipid oxidation was higher in the obese than in the lean women (P < 0.05), and it was significantly correlated with body fatness (P < 0.01). A single HP meal consumption produced higher postprandial fat oxidation as compared with HC meal intake (P < 0.02), in both obese and lean subjects, with no apparent changes in glucose oxidation rates. Furthermore, postprandial fat utilisation after the test meal intake was higher in obese than in the lean women (P < 0.01). The time course of 13CO2 in breath followed a similar pattern in both dietary groups, although a non-statistically significant higher trend in protein and 13C-leucine oxidation was found in the HP group.

CONCLUSIONS

Net lipid oxidation depends on both short-term dietary composition intake and fat body mass, being significantly higher after a relatively high protein meal as compared to a balanced diet intake and in obese women as compared to lean controls.

Ketoconazole, an antifungal agent, protects against adiposity induced by a cafeteria diet

Ketoconazole, an anti-glucocorticoid agent, is widely used in humans as an antifungal agent. It inhibits ergosterol synthesis and reduces cortisol levels in the treatment of Cushing's Syndrome. The aim of this work was to study the drug's preventive potential against adiposity induced by a high-fat cafeteria diet in rats. Female Wistar rats were fed on standard pelleted diet or cafeteria diet during 42 days in the presence or absence of an oral treatment with ketoconazole (24 mg/kg of body weight). The cafeteria diet increased energy intake and body weight. In addition, this high-fat diet increased body-fat weight and adipose tissue depots analyzed. Interestingly, ketoconazole was able to protect against increased total body fat and adipose depot enlargement induced after cafeteria-diet feeding. Moreover, ex vivo isoproterenol-induced lipolysis was reduced in adipocytes from cafeteria-fed animals; this decrease was reverted by treatment with ketoconazole. Thus, ketoconazole was able to protect against adiposity induced by a cafeteria diet, revealing an interaction between fat intake and glucocorticoids on adipose deposition.

Gene expression changes in rat white adipose tissue after a high-fat diet determined by differential display

The differences in gene expression pattern of visceral white adipose tissue between control and high-fat-fed rats were compared using the mRNA differential display methodology. The results, confirmed by Northern blot, showed eight genes upregulated: adiponectin, fibrillin-1, transferrin, Y-box binding protein-1, IgE receptor beta chain (FcRIbeta), alpha-1 haemoglobin, and ribosomal proteins S10 and L7 and four genes downregulated: caveolin-2, lactate dehydrogenase-A, mitochondrial 16S rRNA, and mitochondrial cytochrome oxidase subunit I/serine tRNA. Two of these genes have been already related to obesity (adiponectin and caveolin-2) while the others are known to participate in metabolic, signalling or transcription regulation pathways that can be relevant in energy (lipid and/or carbohydrate) metabolism.

Daily ingestion of fermented milk containing Lactobacillus casei DN114001 improves innate defense capacity in healthy middle-aged people

Different lactic acid bacteria have often been administered as a dietary means to enhance immune system activity. Based on this statement, the aim of the current work was to test the effects of a Lactobacillus casei DN114001 fermented milk consumption on the immune response capacity in middle-age volunteers. Forty-five healthy volunteers, 24 women and 21 men (aged: 51-58 years), were randomized into two groups to receive three cups per day of a L. casei DN114001 (10(8)-10(10) ufc/g) fermented milk (n = 23), or placebo (n = 22), during an 8-week period. Measurements were performed before (day 0), and after the nutritional intervention (day 56). After the trial, no changes in immune cell proportions were detected, but the probiotic-treated group increased oxidative burst capacity of monocytes (probiotic group: p = 0.029; placebo group: p = 0.625), as well as NK cells tumoricidal activity (probiotic group: p = 0.023; placebo group: p = 0.125). Results showed that daily intake of fermented milk containing Lactobacillus casei DN114001 could have a positive effect in modulating the innate immune defense in healthy-middle-age people.

A procedure to determine the radiation isocenter size in a linear accelerator

Measurement of radiation isocenter is a fundamental part of commissioning and quality assurance (QA) for a linear accelerator (linac). In this work we present an automated procedure for the analysis of the stars-shots employed in the radiation isocenter determination. Once the star-shot film has been developed and digitized, the resulting image is analyzed by scanning concentric circles centered around the intersection of the lasers that had been previously marked on the film. The center and the radius of the minimum circle intersecting the central rays are determined with an accuracy and precision better than 1% of the pixel size. The procedure is applied to the position and size determination of the radiation isocenter by means of the analysis of star-shots, placed in different planes with respect to the gantry, couch and collimator rotation axes.

Effects of a beta3-adrenergic agonist on the immune response in diet-induced (cafeteria) obese animals

Molecules with affinity for beta3-adrenoceptors are not only effective anti-obesity agents in rodent models, but may play a role in the regulation of the immune response. The aim of the current investigation was to analyse the effects of trecadrine on the immune response in diet-induced (cafeteria) obese rats. Male Wistar rats were divided into 2 groups, the control group (C, n=9) was fed with the standard pelleted chow laboratory diet, while the other group was fed with a high-fat (cafeteria) diet. Cafeteria-fed rats were divided into two new subgroups (n=9 each), which received either i.p. saline (obese, O) or trecadrine (1mg/kg/day) (obese+trecadrine, O+T) daily for 5 weeks. Lymphocyte subpopulations and the proliferative response were determined by validated procedures. The administration of trecadrine was able to prevent the onset of obesity in cafeteria-fed rats. Trecadrine-treatment to obese animals appeared to improve the number of lymphocyte subpopulations (CD4+ and CD8+) as compared to those animals only receiving the high-fat diet, being the values of the trecadrine-treated animals on the high-fat diet similar to the control rats. However, the lymphoproliferative response when stimulated with several mitogens was markedly reduced by the cafeteria intake and was further decreased by the beta3-adrenergic administration. The spleen mRNA expression level of UCP2, PPARgamma and Ob-Rb were not affected by the trecadrine treatment. Summing up, at the immune system level, trecadrine administration increased the proportion of CD4+ spleen lymphocytes, although it was not able to restore the lymphocyte proliferative response which was depressed.