Role of adipose tissue in melanoma cancer microenvironment and progression.

BACKGROUND: An epidemiological association between excess weight and increased risk of cancer has been described in melanoma, for which the physiopathological mechanisms are still unknown. The study of tumor microenvironment and of the role of adipocytes in cancer development, progression and metastasis has recently received great interest. However, the role of peritumoral adipocytes has been characterized only in a few types of cancer, and in melanoma it still remains to be defined. METHODS: We investigated the interactions between adipocytes and melanoma cells using an in vitro co-culture system. We studied the morphological and functional properties of 3T3-L1 adipocytes before and after co-culture with A375 melanoma cells, in order to assess the role of adipocytes on melanoma migration. RESULTS: Morphological analysis showed that after 6 days of co-culture 3T3-L1 adipocytes were reduced in number and size. Moreover, we observed the appearance of dedifferentiated cells with a fibroblast-like phenotype that were not present in controls and that had lost the expression of some adipocyte-specific genes, and increased the expression of collagen, metalloproteinases and genes typical of dedifferentiation processes. Through the Matrigel Invasion Test, as well the Scratch Test, it was possible to observe that co-culture with adipocytes induced in melanoma cells increased migratory capacity, as compared with controls. In particular, the increase in migration observed in co-culture was suppressed after adding the protein SFRP-5 in the medium, supporting the involvement of the Wnt5a pathway. The activation of this pathway was further characterized by immunofluorescence and western blot analysis, showing in melanocytes in co-culture the activation of ß-catenin and LEF-1, two transcription factors involved in migration processes, neo-angiogenesis and metastasis. CONCLUSIONS: These data allow us to hypothesize a dedifferentiation process of adipocytes toward fibroblast-like cells, which can promote migration of melanoma cells through activation of Wnt5a and the intracellular pathways of ß-catenin and LEF-1.

Evaluation of three different manual techniques of sharpening curettes through a scanning electron microscope: a randomized controlled experimental study.

OBJECTIVE: The purpose of this study was to compare the effectiveness of three different techniques for manually sharpening of periodontal curettes (PCs) by examining the blades with the aid of scanning electron microscope (SEM). METHODS: Three groups were considered based on three sharpening methods used: group A (moving a PC over a stationary stone); group B (moving a stone over a stationary PC) and group C (moving a PC over a stone fixed, placed on a 'sharpening horse'). After the sharpening, the blades were examined using SEM. The SEM images were assessed independently by five different independent observers. An evaluation board was used to assign a value to each image. A preliminary pilot study was conducted to establish the number of samples. Pearson's correlation test was used to assess the correlations between measurements. anova test with Bonferroni's post hoc test was used to compare the three groups. RESULTS: Sixty PCs (20 PCs per group) were used in this study. Statistically significant differences emerged between the three groups (P-value = 0.001). Bonferroni's test showed that the difference between groups A and B was not statistically significant (P-value = 0.80), while it was significant for the comparisons between groups A and C (P-value = 0.005) and between groups B and C (P-value = 0.001). CONCLUSIONS: The sharpening technique used in group C, which involved the use of the sharpening horse, proved the most effective.

Pancreatic fat accumulation and its relationship with liver fat content and other fat depots in obese individuals.

BACKGROUNDS AND AIMS: We assessed the associations between pancreatic fat accumulation and other fat compartments, including liver fat and visceral adipose tissue as well as insulin resistance and other metabolic abnormalities in obese individuals. SUBJECTS AND METHODS: We studied 42 Caucasian adults with obesity [20 men and 22 women; mean body mass index (BMI) 35.2±4 kg/m(2)], who had no history of liver diseases or excessive alcohol consumption, in which subcutaneous, visceral, liver, and pancreatic fat contents were quantified by an in-opposed-phase magnetic resonance imaging (MRI) technique. RESULTS: Compared with patients in the lower tertile (<5.6%, no.=15), those in the upper tertile of liver fat content had more visceral adipose tissue, greater insulin resistance and had higher values of BMI, blood pressure, triglycerides and lower HDL-cholesterol and adiponectin. Notably, pancreatic fat accumulation also significantly increased across tertiles of liver fat content. In univariate analysis, the strongest correlates of pancreatic fat were visceral and liver fat contents (r=0.80 and r=0.54, p<0.001- 0.0001, respectively). Pancreatic fat accumulation was also moderately associated with insulin resistance and other metabolic syndrome features. However, when adjusted for age, gender and visceral adipose tissue, the associations of pancreatic fat accumulation with liver fat and other metabolic abnormalities were no longer significant. CONCLUSIONS: There are significant associations between pancreatic fat accumulation and liver fat content as well as insulin resistance and other metabolic abnormalities in obese, but otherwise healthy, individuals. However, these associations are largely mediated by the amount of visceral adipose tissue.

Mechanisms of adipose tissue extracellular matrix alterations in an in vitro model of adipocytes hypoxia and aging.

Fibrosis has been considered as a hallmark of dysfunctional adipose tissue (AT), however the role and mechanisms of fibrosis in the age related AT dysfunction are not yet well characterized. The aim of the study was to investigate the mechanisms of extracellular matrix (ECM) alterations and the role of caveolins, using an in vitro model of adipocyte aging and hypoxia. Hypoxic adipocytes, but also aged adipocytes, were characterized by a significant increase in gene expression of pro-inflammatory cytokines and ECM components. Immunofluorescence analysis confirmed an increase in collagen VI-A3 in hypoxic and also in aged adipocytes. However aged adipocytes were characterized by only a slight increase in HIF1α immunofluorescence and by a more relevant increase in senescence compared to hypoxic and mature adipocytes, with an increase in p-53 protein and a decrease in SIRT 1 protein. Immunofluorescence and western blot analysis revealed a significant decrease in caveolin-1 expression in hypoxic adipocytes and even more in aged adipocytes. In conclusions, aging adipocytes are associated to alteration of ECM and fibrosis, by modulation of the caveolins through complex mechanisms where inflammation, hypoxia and cellular senescence are coexisting.

Body composition and pulmonary function in the elderly: a 7-year longitudinal study.

OBJECTIVE: To evaluate over a 7-year follow-up period the relationships between changes in body composition, fat distribution and pulmonary function in a sample of elderly men and women. DESIGN: Longitudinal clinical study. SUBJECTS: A total of 47 women and 30 men aged 71.6+/-2.3 and 71.7+/-2.2 years, respectively, at baseline with body mass index (BMI) values of 24.96+/-3.28 and 27.04+/-3.35 kg m(-2) were followed for 7 years. MEASUREMENTS: Body weight, waist circumference, sagittal abdominal diameter (SAD), fat-free mass (FFM) and fat mass as measured by dual energy X-ray absorptiometry (DXA) and forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC) by spirometry were evaluated at baseline and after a 7-year mean follow-up. RESULTS: In women as in men there were no significant changes in weight, SAD and BMI. A significant decrease in height and FFM was observed in both women and men. Height-adjusted FEV1 and FVC decreased significantly in women and men over the 7-year follow-up. Changes in SAD were the most powerful predictors of 7-year follow-up of FEV1 and FVC after taking into account, respectively, baseline FEV1 and FVC. Linear regression analysis, performed by using 7-year follow-up lung function variables as dependent variables and changes in body composition variables as independent variables, showed that 1 cm SAD increase predicted a decrease in FEV1 and FVC of 31 and 46 ml, respectively, and 1 kg FFM decrease predicted a decrease in FVC of 38 ml. After subdividing our study population into four categories of change in FFM and SAD, patients with decreased FFM and increased SAD showed the highest probability of having a worsening in FEV1 and FVC. CONCLUSION: Increase in abdominal fat and FFM decline are significant predictors of lung function decline in the elderly. Old subjects developing both abdominal fat gain and FFM loss show the highest probability of developing worsening in lung function.

Relation between adiponectin and bone mineral density in elderly post-menopausal women: role of body composition, leptin, insulin resistance, and dehydroepiandrosterone sulfate.

INTRODUCTION: Adipocytokines have been proposed as new mediators of the protective effects of fat mass on the skeleton. The aim of this study was to test the relationship between adiponectin, leptin, and bone mineral density (BMD), independently of body composition, insulin resistance, and other factors known to affect bone metabolism. METHODS: Thirty-six post-menopausal non-diabetic elderly women, with ages ranging from 66 to 77 yr took part in the study. In all subjects we evaluated body weight, height, body mass index (BMI), waist circumference, adiponectin, leptin, insulin, DHEAS, and homeostasis model assessment of insulin resistance (HOMA), as well as yr since menopause. Total body fat mass (FM) and BMD at whole body and femoral level were measured with Dual energy X-ray Absorptiometry (DXA). Volumetric BMD was defined as the ratio between total body BMD and height. RESULTS: Leptin was positively and adiponectin negatively related with whole body and femoral BMD. Positive associations between insulin, HOMA, DHEAS, and BMD measures were also found. After adjusting for FM, only adiponectin maintained a significant relation with whole body and femoral BMD; the strength of this association was reduced after adjustment for insulin resistance, estimated by HOMA. In stepwise multiple linear regression analyses adiponectin explained 11.7% of total BMD variance, 17.4% of femoral neck BMD variance, and 30.7% of volumetric BMD variance, independently of BMI, FM, leptin, HOMA, and DHEAS. CONCLUSIONS: The present study may suggest possible involvement of adiponectin in bone metabolism, independently of FM and insulin resistance even in elderly post-menopausal women.

Individual versus group therapy for obesity: comparison of dropout rate and treatment outcome.

AIMS: To compare outcome and dropout rates of an individual nutritional counselling (IT) and a cognitive behavioural group therapy (GT) after 6 months of treatment. METHODS: One hundred and twenty-nine women (72 in the IT and 57 in the GT group) aged 18-65 years, with body mass index (BMI) > or =25 kg/m(2). Body weight, height and waist circumference were measured. Obesity Related Well Being 97 questionnaire (ORWELL 97), Body Uneasiness Test (BUT), Symptom Check List 90 (SCL 90) and Binge Eating Scale (BES) tests were used to evaluate psychometrical variables. RESULTS: After 6 months, 37.2% (54.2% of initial IT sample and 15.8% of initial GT sample) of subjects abandoned the treatment programme. Completers were older (p<0.03) and had a worse BUTa General Severity Index score (p<0.04) than non-completers. IT had a higher dropout rate than GT. After 6 months of treatment completers lost 6.39% of initial weight and obtained improvements in all studied variables, except scores of SCL 90 and BUTb Positive Symptom Distress Index questionnaires. IT and GT groups did not differ significantly. CONCLUSIONS: Outcomes of IT and GT were comparable in all studied variables, whereas dropout rate of IT was higher than that of GT, suggesting that some characteristics of GT can contribute to the reduction of attrition. Younger age and better body image (measured by BUT) were associated to dropout. After weight loss we observed improvements in almost all variables in both groups without differences.

Role of Anti-Inflammatory Cytokines on Muscle Mass and Performance Changes in Elderly Men and Women.

OBJECTIVES: Investigate the presence of a correlation between systemic inflammatory profile of community-dwelling individuals and the loss of muscular mass and performance in old age over a 4.5y follow-up, focusing on the role of anti-inflammatory cytokines in muscular changes in elderly. DESIGN: Longitudinal clinical study. SETTING: Subjects were randomly selected from lists of 11 general practitioners in the city of Verona, Italy. PARTICIPANTS: The study included 120 subjects, 92 women and 28 men aged 72.27±2.06 years and with BMI of 26.52±4.07 kg/m2 at baseline. MEASUREMENTS: Six minutes walking test (6MWT), appendicular and leg fat free mass (FFM) as measured with Dual Energy X-ray absorptiometry, were obtained at baseline and after 4.5 years (4.5y) of mean follow-up. Height, weight, body mass index (BMI), and circulating levels of TNFα, IL-4, IL-10, and IL-13 were evaluated at baseline. RESULTS: A significant reduction of appendicular FFM, leg FFM and 6MWT performance (all p<0.001) was observed after 4.5 y follow-up. In a stepwise regression model, considering appendicular FFM decline as dependent variable, lnIL-4, BMI, baseline appendicular FFM, lnTNFα and lnIL-13 were significant predictors of appendicular FFM decline explaining 30.8% of the variance. While building a stepwise multiple regression considering leg FFM as a dependent variable, lnIL-4, BMI and leg FFM were significant predictors of leg FFM decline and explained 27.4% of variance. When considering 6MWT decline as a dependent variable, baseline 6MWT, lnIL-13 and lnTNFα were significant predictors of 6MWT decline to explain 22.9% of variance. CONCLUSIONS: Our study suggest that higher serum levels of anti-inflammatory markers, and in particular IL-4 and IL-13, may play a protective role on FFM and performance maintenance in elderly subjects.

Assessing the Risk of Sarcopenia in the Elderly: The Mini Sarcopenia Risk Assessment (MSRA) Questionnaire.

OBJECTIVES: to validate the MSRA questionnaire proposed as prescreening tool for sarcopenia, in a population of community-dwelling elderly subjects. DESIGN: observational study. SETTING: community dwelling elderly subjects. PARTICIPANTS: 274 community dwelling elderly subjects, 177 women and 97 men, aged 66-78 years. MEASUREMENTS: Based on EWGSOP diagnostic criteria subjects were classified as sarcopenic and non-sarcopenic. The Mini Sarcopenia Risk Assessment (MSRA) questionnaire, is composed of seven questions and investigates anamnestic and nutritional characteristics related to risk of sarcopenia onset (age, protein and dairy products consumption, number of meals per day, physical activity level, number of hospitalizations and weight loss in the last year). RESULTS: 33.5% of the study population, were classified as sarcopenic. With the 7-item MSRA score, subjects with a score of 30 or less, had a 4-fold greater risk of being sarcopenic than subjects with a score higher than 30 (OR:4.20;95% CI:2.26-8.06); area under the ROC curve was 0.786 (95% CI:0.725-0.847). In a logistic regression, considering as dependent variable the probability of being sarcopenic, and as independent variables the 7 items of the questionnaire, two items (number of meals and milk and dairy products consumption) showed non-significant diagnostic power. A 5-item score was then derived and the area under the ROC curve was 0.789 (95% IC:0.728-0.851). Taking into account the cost of false positive and false negative costs and the prevalence of sarcopenia, the "optimal" threshold of the original MSRA score (based on 7 items) is 30, with a sensitivity of 0.804 and a specificity of 0.505, while the "optimal" threshold of the MSRA score based on 5 items, is 45, with a sensitivity of 0.804 and a specificity of 0.604. CONCLUSION: this preliminary study shows that the MSRA questionnaire is predictive of sarcopenia and can be suggested as prescreening instrument to detect this condition. The use of a short form of the MSRA questionnaire improves the capacity to identify sarcopenic subjects.

Arterial compliance may be reduced by ingestion of red wine.

The aim of this study was to assess the effect of alcohol on blood pressure and arterial compliance over 24 h in a group of volunteers, comparing the same group of subjects on two consecutive but separate days, one with alcohol intake (alcohol day) and one free of alcohol (control day). We studied 18 healthy subjects (mean age 34.2 years, range 25-53). The subjects received the two days in random order. On the alcohol day, the subjects were asked to drink two glasses of red wine (12% ethanol) between 1830 hours and 0430 hours. Measurements of heart rate, blood pressure and QKD interval (Q wave to Korotkoff (K) sound, diastolic phase (D) using Diasys Integra (Novacor, France)) were recorded (usually 1500 hours to 1500 hours). Three 'ingestion' periods were defined, from 1500 hours to 1830 hours ('before'), 1900 hours to 0430 hours ('during') and from 0430 hours to the following afternoon ('after') on both the alcohol day and on the control day. Red wine increased heart rate during alcohol ingestion and reduced arterial compliance after ingestion. The significant effect of interaction between day and ingestion period on heart rate, diastolic blood pressure and QKD were found, suggesting that the differences in response among the ingestion periods depended on whether alcohol has been consumed that day. For the first time our study indicates the effect of alcohol on 24 h arterial stiffness in a healthy group of volunteers.

Inflammation and nutritional status as predictors of physical performance and strength loss during hospitalization.

OBJECTIVES: The aim of this study was to examine changes in physical performance and handgrip strength during hospitalization as well as to evaluate their interrelationship with inflammatory and nutritional status. DESIGN: Data were available on 302 elderly patients with a mean age of 80.83±7.14 years. Handgrip strength, gait speed and chair-stand test were assessed at admission and before discharge. In all subjects, serum CRP values and Mini Nutritional Assessment scores were also evaluated. RESULTS: The risk of worsening in chair-stand test performance was 4.2 (95% confidence interval (CI): 1.574-11.310) for subjects with simultaneous presence of malnutrition and CRP⩾50 and 3.3 mg/dl (95% CI: 1.127-9.423) for subjects with CRP⩾50 mg/l not malnourished in comparison with subjects with Mini Nutritional Assessment (MNA)⩾24 and CRP⩽10 mg/l. The risk of handgrip strength loss was 8.8 (95% CI: 3.545-21.662) in subjects with simultaneous presence of malnutrition and CRP⩾50 and 2.9 mg/dl (95% CI: 1.223-6.783) in subjects with CRP⩾50 mg/l not malnourished in comparison with subjects with MNA⩾24 and CRP⩽10 mg/l. CONCLUSIONS: Simultaneous presence of high CRP values and malnutrition determines an additive effect on muscle strength loss and physical performance.

Effect of moderate weight loss on hepatic, pancreatic and visceral lipids in obese subjects.

OBJECTIVE: To compare the effects of weight loss on visceral and subcutaneous abdominal fat, liver and pancreas lipid content and to test the effects of these changes on metabolic improvement observed after weight loss. DESIGN: Weight-loss program designed to achieve a loss of 7-10% of the initial weight. SUBJECTS: 24 obese subjects (13 males and 11 females) with age ranging from 26 to 69 years and body mass index (BMI) 30.2-50.5 kg m(-2). MEASUREMENTS: weight, BMI, waist circumference, body composition as assessed by dual-energy X-ray absorptiometry, metabolic variables, leptin, adiponectin, visceral and subcutaneous abdominal fat, liver and pancreas lipid content as assessed by magnetic resonance were evaluated before and after weight loss achieved by hypocaloric diet. RESULTS: After a mean body weight decrease of 8.9%, BMI, waist circumference, fat mass, all metabolic variables, homeostasis model assessment of insulin resistance (HOMA), alanine amino transferase, gamma glutamyl transpeptidase, high-sensitivity C-reactive protein (hs-CRP) and leptin, but not adiponectin and high-density lipoprotein-cholesterol, significantly decreased (all P<0.01). Visceral and subcutaneos abdominal fat, liver and pancreas lipid content significantly decreased (all P<0.01). Percent changes in liver lipid content were greater (84.1±3%) than those in lipid pancreas content (42.3±29%) and visceral abdominal fat (31.9±15.6%). After weight loss, percentage of subjects with liver steatosis decreased from 75 to 12.5%. Insulin resistance improvement was predicted by changes in liver lipid content independently of changes in visceral fat, pancreas lipid content, systemic inflammation, leptin and gender. CONCLUSION: Moderate weight loss determines significant decline in visceral abdominal fat, lipid content in liver and pancreas. Reduction of liver lipid content was greater than that of pancreas lipid content and visceral fat loss. Liver lipid content is the strongest predictor of insulin resistance improvement after weight loss.

Adiponectin gene expression and adipocyte NF-kappaB transcriptional activity in elderly overweight and obese women: inter-relationships with fat distribution, hs-CRP, leptin and insulin resistance.

OBJECTIVE: The regulatory processes that modulate adiponectin production and the mechanisms involved in nuclear factor kB (NF-kB) transcriptional activity in human adipocytes are not yet fully known. The aim of our study was to evaluate the inter-relationships between body fat, fat distribution, systemic inflammation, insulin resistance, leptin and the serum and subcutaneous adipose tissue gene expression levels of tumor necrosis factor-alpha (TNF-alpha), adiponectin and the inhibitor kappa B-alpha (IkB-alpha), in subjects with a wide range of body mass index (BMI). We also wanted to determine which of these variables was most closely related to adiponectin gene expression and adipocyte NF-kB transcriptional power. METHODS: A total of 27 women aged between 50 and 80 years, with BMI ranging from 22.1 to 53.3 kg/m(2), were studied. In all subjects BMI, waist circumference, body composition by dual X-ray absorptometry, triglycerides, cholesterol, high-density lipoprotein cholesterol (HDL-Ch), glucose, insulin, homeostasis model assessment of insulin resistance (HOMA), high-sensitive C-reactive protein (hs-CRP), serum adiponectin, leptin and TNF-alpha were evaluated. Subcutaneous adipose tissue biopsies were taken from the abdomen of all subjects and the mRNA levels of adiponectin, TNF-alpha and IkB-alpha were determined. RESULTS: BMI and waist circumference were associated positively with leptin, HOMA, and hs-CRP, and negatively with HDL-Ch; waist was also associated with adiponectin and IkB-alpha mRNA. HOMA was negatively associated with serum adiponectin and adiponectin mRNA. Hs-CRP was negatively associated with IkB-alpha mRNA, and was positively associated with HOMA. Step-down multiple regression analysis was performed to determine the joint effects of BMI, waist circumference, triglycerides, HDL-Ch, HOMA, hs-CRP, leptin, serum and TNF-alpha mRNA on adiponectin gene expression: waist circumference and leptin were both included in the best fitting regression equation for predicting adiponectin gene expression (R(2)=0.403, P=0.006). Stepwise multiple regression analysis was performed, considering IkB-alpha mRNA as a dependent variable and BMI, waist, HDL-Ch, HOMA, hs-CRP and adiponectin mRNA as independent variables. Adiponectin mRNA was the only variable to enter the regression (R(2)=0.406, P<0.001). CONCLUSION: Our results suggest that abdominal adiposity and leptin are independent predictors of adiponectin gene expression and that in human adipocytes, adiponectin gene expression is strongly related to IkB-alpha mRNA.

Takayasu's arteritis: a cause of prolonged arterial stiffness.

OBJECTIVES: Cardiovascular disease is a major cause of mortality and morbidity in patients with Takayasu's arteritis (TA). Increased arterial stiffness is an independent risk factor and predictor of cardiovascular mortality in a variety of diseases. Pulse wave velocity (PWV) and the augmentation index (AI) are used as clinical measurements of arterial stiffness. METHODS: Data are presented from 10 patients with TA and 11 normal controls obtained between 2000 and 2004. Arterial compliance was assessed non-invasively by measurement of PWV, using the Complior system, and calculation of the aortic AI. RESULTS: TA patients (mean age 40.8+/-13.2 yr) were compared with a control group of healthy women from a parallel study (mean age 32.3+/-5.5 yr). The mean carotid-femoral PWV (PWV-CF) was higher in TA patients (P = 0.03). In addition, both aortic AI derived from the radial artery (P = 0.002) and carotid AI (P = 0.03) were higher in TA patients compared with controls. PWV-CF did not correlate with CRP (r = - 0.23, P = 0.23) or ESR (r = - 0.19, P = 0.27). Similar results were obtained for the correlation of carotid-radial PWV with CRP (r = 0.15, P = 0.32) and ESR (r = 0.33, P = 0.14). CONCLUSIONS: Our data show that TA is associated with elevated arterial stiffness in the central aorta, which may persist when the disease is quiescent. These data suggest that PWV represents a means by which cardiovascular risk can be detected and monitored in TA, and highlights the importance of effective management of cardiovascular risk factors in these patients.

Health consequences of obesity in the elderly: a review of four unresolved questions.

Obesity prevalence is growing progressively even among older age groups. Controversy exists about the potential harms of obesity in the elderly. Debate persists about the relation between obesity in old age and total or disease-specific mortality, the definition of obesity in the elderly, its clinical relevance, and about the need for its treatment. Knowledge of age-related body composition and fat distribution changes will help us to better understand the relationships between obesity, morbidity and mortality in the elderly. Review of the literature supports that central fat and relative loss of fat-free mass may become relatively more important than BMI in determining the health risk associated with obesity in older ages. Weight gain or fat redistribution in older age may still confer adverse health risks (for earlier mortality, comorbidities conferring independent adverse health risks, or for functional decline). Evaluation of comorbidity and weight history should be performed in the elderly in order to generate a comprehensive assessment of the potential adverse health effects of overweight or obesity. The risks of obesity in the elderly have been underestimated by a number of confounders such as survival effect, competing mortalities, relatively shortened life expectancy in older persons, smoking, weight change and unintentional weight loss. Identification of elderly subjects with sarcopenic obesity is probably clinically relevant, but the definition of sarcopenic obesity, the benefits of its clinical identification, as well as its relation to clinical consequences require further study. Studies on the effect of voluntary weight loss in the elderly are scarce, but they suggest that even small amounts of weight loss (between 5-10% of initial body weight) may be beneficial. In older as well as in younger adults, voluntary weight loss may help to prevent the adverse health consequences of obesity.