Resistin: A reappraisal.

From a biological point of view, aging can be considered a progressive inability of an organism to react to stress, maintain homeostasis, and survive unfavourable changes during post-maturational life. The expression of several adipokines changes during aging and for some changes, a role in the onset of chronic disease and frailty has been proposed. Among adipokines, resistin was shown in recent studies to play a key role in aging. Resistin is a small secreted protein that regulates glucose metabolism in mammalians. High resistin levels induce insulin resistance and exert proinflammatory effects. Consistently, resistin has been shown to play a pivotal role in various metabolic, inflammatory, and autoimmune diseases. Herein, the role of resistin as a molecular link between aging and age-related conditions was reviewed and the clinical implications of this knowledge discussed.

Validation of the Photography Method for Nutritional Intake Assessment in Hospitalized Elderly Subjects.

OBJECTIVE: The aim of the present study was to validate the photographic indirect method as an accurate and specific tool to assess nutritional intake in a cohort of elderly hospitalized patients. DESIGN: this is a prospective observational study. SETTING: hospital (geriatric acute ward and transitional care of IRCCSS AUO San Martino Hospital, Genoa, Italy). PARTICIPANTS: 255 consecutive elderly hospitalized patients. MEASUREMENTS: assessment of malnutrition by: Mini nutritional assessment (MNA) and abbreviated Comprehensive geriatric assessment (CIRS; Barthel index, SPMSE). The direct method (Gold standard): food dish weight (before lunch) and residual (after lunch) food dish weight and estimation of the percentage of eaten food and of residual food for each dish. The percentages of food intake and residual food were calculated according to the following formula: intake %= initial weight of the dishes- residual food weight)/ initial weight dish x100. The unit of variable was the percentage. The indirect photographic method with extrapolation of the lunch food intake by photographic method confronting initial meal and residual meal (25% quartile food dish estimation). RESULTS: The results showed a significant correlation between the direct method (weighing residual food) and the indirect photographic method(n=255; r=0.9735; p<0.001) as well as a significant positive correlation between the indirect photographic method and the food caloric estimation calculated by the direct method (n=255; r= 0.6489, p<0.001). Intraclass coefficient (ICC), showed a highly significant degree of agreement between the gold standard and the indirect photographic method (ICC: 0.69; p<0.0001). Additionally, the results showed a good inter rater agreement of the indirect photographic method (kappa-statistic measure of interrater agreement: (Z=13.04; p<0.001); agreement 70.29% e Kappa=0.5965) and a good specificity of the indirect method as it was independent on the single food item. CONCLUSIONS: The study originally provided the validation of the indirect photographic method for the assessment of nutritional intake in a vast cohort of hospitalized elderly subjects. The present results moved a step forward in the appropriate assessment of nutrition intake in frail elderly, providing an easy to use tool that may be incorporate in routine clinical practice for early and targeted therapeutic interventions.

Physician assisted suicide and clinical vulnerability: a slippery slope.

AIMS: The Belgian case of a 24 years' woman affected by resistant depression, who obtained the legal right to assisted suicide rehearsed ethical issues. From the famous Chabot case of the Dutch court in 1994, accumulating legal evidence indicates that the unbearable psychiatric suffering may be equate to the physical struggle of end of life patients. The Belgian law has addressed assisted suicide as an option in case of unbearable psychic suffering with no future prospective. DESIGN: It is unlikely that the practice of euthanasia may be mechanistically reduced to the provision of a suicide as alleviating the burden of suffering in depression is a long life commitment; moreover, the principle of patient's self determination and autonomy is highly debatable: the closure to the future, the hopelessness and the suicidal ideation represent per se core features of depression. Might they be discriminated as non pathological in assessing patients' competence and how? DISCUSSION: The slippery slopes is even more upsetting when dealing with elderly affected by chronic disability. Some body of evidence justified suicide in elderly as the final auto determination to preserve the person's dignity, and quality of life. The growing scenario of economic shortages in heath care system seems to further legalize the social prejudice and the ageistic discrimination towards elderly with disability. The silver tsunami will face the challenge of true self determination; will it be acted through assisted suicide or through a rebuilding of western heath care policies to fulfill the emergent needs of an aging population?

Vitamins D3 and K2 may partially counterbalance the detrimental effects of pentosidine in ex vivo human osteoblasts.

Osteoporosis is a metabolic multifaceted disorder, characterized by insufficient bone strength. It has been recently shown that advanced glycation end products (AGEs) play a role in senile osteoporosis, through bone cell impairment and altered biomechanical properties. Pentosidine (PENT), a wellcharacterized AGE, is also considered a biomarker of bone fracture. Adequate responses to various hormones, such as 1,25-dihydroxyvitamin D3, are prerequisites for optimal osteoblasts functioning. Vitamin K2 is known to enhance in vitro and in vitro vitamin D-induced bone formation. The aim of the study was to assess the effects of Vitamins D3 and K2 and PENT on in vitro osteoblast activity, to convey a possible translational clinical message. Ex vivo human osteoblasts cultured, for 3 weeks, with vitamin D3 and vitamin K2 were exposed to PENT, a well-known advanced glycoxidation end product for the last 72 hours. Experiments with PENT alone were also carried out. Gene expression of specific markers of bone osteoblast maturation [alkaline phosphatase, ALP; collagen I, COL Iα1; and osteocalcin (bone-Gla-protein) BGP] was measured, together with the receptor activator of nuclear factor kappa-B ligand/osteoproteregin (RANKL/OPG) ratio to assess bone remodeling. Expression of RAGE, a well-characterized receptor of AGEs, was also assessed. PENT+vitamins slightly inhibited ALP secretion while not affecting gene expression, indicating hampered osteoblast functional activity. PENT+vitamins up-regulated collagen gene expression, while protein secretion was unchanged. Intracellular collagen levels were partially decreased, and a significant reduction in BGP gene expression and intracellular protein concentration were both reported after PENT exposure. The RANKL/OPG ratio was increased, favouring bone reabsorption. RAGE gene expression significantly decreased. These results were confirmed by a lower mineralization rate. We provided in vitro evidence that glycoxidation might interfere with the maturation of osteoblasts, leading to morphological modifications, cellular malfunctioning, and inhibition of the calcification process. However, these processes may be all partially counterbalanced by vitamins D3 and K2. Therefore, detrimental AGE accumulation in bone might be attenuated and/or reversed by the presence or supplementation of vitamins D3 and K2.

Effects of competition on acute phase proteins and lymphocyte subpopulations - oxidative stress markers in eventing horses.

The aim of the study was to evaluate markers of the acute phase response (APR) in eventing horses by measuring acute phase proteins (APP) (haptoglobin, Hp, and serum amyloid A, SAA), lysozyme, protein adducts such as pentosidine-like adducts (PENT), malondialdehyde adducts (MDA), hydroxynonenal adducts (HNE) and total advanced glycation/glycoxidation end products (AGEs), complete blood count and lymphocyte subpopulations (CD4+, CD8+ and CD21+) both at rest and at the end of an eventing competition. Blood samples were collected from eight Warmblood horses (medium age 10 ± 3) during an official national 2-day event competition at rest (R) and 10 min after the arrival of the cross-country test on the second day. Exercise caused a significant increase in red blood cell number, haemoglobin, packed cell volume, neutrophils, white blood cell and lymphocyte number; however, these values remained within the normal range. The CD4+ and CD8+ cells significantly increased, whereas the CD21+ lymphocytes decreased; a significant increase in serum SAA, lysozyme and protein carbonyl derivates was also observed. Two-day event causes significant changes in APR markers such as lysozyme, protein carbonyl derivates (HNE, AGEs, PENT) and lymphocyte subpopulations. The data support the hypothesis that 2-day event may alter significantly APR markers. Limitations of the study were the relatively small sample size and sampling time conditioned by the official regulations of the event. Therefore, further studies are needed to investigate the time required for recovery to basal values in order to define the possible effects on the immune function of the athlete horse.

Doloplus-2 pain assessment: an effective tool in patients over 85 years with advanced dementia and persistent pain.

Persistent pain in the elderly with dementia is neglected and effective pain diagnostic tools still lack. The aim of the study was to re-assess pain after 1 year in a group of elderly with dementia, resident in a Nursing Home. Doloplus-2 scale was adopted to detect pain and to evaluate its adequacy to address analgesia. Thirty-six out of 90 residents were affected by moderate-severe dementia and 23 patients with persistent pain were enrolled in the study. The results showed a significant reduction of Doloplus-2 score in the observational period (p <0.001) and of its mean score below the pain threshold (p <0.0001). This case analysis confirmed the clinical utility of Doloplus-2 to detect pain in patients with very advanced age and with severe dementia. The tool also confirmed its handiness and clinical applicability by nurses in order to support a systematic pain assessment in long term care.

Association of the glycoxidative stress marker pentosidine with equine laminitis.

Ponies suffering from recurrent episodes of laminitis when grazed at pasture (pasture-associated laminitis) exhibit phenotypes similar to those associated with human metabolic syndrome. In humans, evidence suggests that the obesity-related morbidities associated with metabolic syndrome, including diabetes and cardiovascular disease, are caused by an increase in the production of advanced glycoxidation end-products (AGEs). These end-products have been recognised as putative pro-inflammatory mediators and are considered a 'risk factor' for human health. However, the evaluation of AGEs in laminitic ponies has not been explored. The aim of this study was to compare plasma concentrations of the AGE pentosidine (PENT) in ponies presenting with clinical features of equine metabolic syndrome (EMS) with a history of recent laminitis and/or showing signs of laminitis at the time of sampling (LP) with those with no prior history of clinical laminitis (NL). Age, body condition score (BCS) and bodyweight were recorded and blood samples collected for the measurement of plasma concentrations of PENT, glucose, insulin, triglycerides (TG), non-esterified fatty acids (NEFA) and cortisol. Insulin sensitivity was assessed by the reciprocal of the square root of insulin (RISQI) and the insulin:glucose ratio. Plasma PENT concentrations were twofold higher (P<0.005) in LP than in NL ponies. Significant (P<0.05) correlations were also evident between PENT and insulin, RISQI, TG and age. These preliminary findings are consistent with the hypothesis that glycoxidation in laminitis is associated with EMS.

Metalloproteinases and advanced glycation end products: coupled navigation in atherosclerotic plaque pathophysiology?

Matrix metalloproteinases (MMPs), their inhibitors (TIMPs) and inflammatory cytokines, such as interleukin-1 (IL-1), are considered markers of evolution and/or instability of atherosclerotic plaques. Accumulation of Advanced Glycation Endproducts (AGE) is a well known phenomenon in diabetes and has also been considered in the pathogenesis of atherosclerosis. Aim of the present study was to analyse the levels of pentosidine, a fluorescent AGE, and to evaluate the expression of MMP-2, TIMP-3, and IL-1 in an ex vivo model of human advanced atherosclerotic plaques. We intended to test the possible correlation between pentosidine and markers of ECM remodelling and inflammation in the atherosclerotic process, and to investigate if classic risk factors, such as diabetes and hypertension, influenced these biochemical parameters. We found that diabetic plaques showed higher level of pentosidine, as expected, but much lower, or even undetectable, expression levels of MMP-2 and TIMP-3; IL-1 expression was not different between diabetic and non diabetic plaques. Hypertension did not influence any of these parameters. Although the statistical correlations between the expression of the considered genes and pentosidine did not reach significance, slight negative trends were noted between TIMP-3 and IL-1 expression vs. pentosidine content. We suggest that in mature diabetic plaques AGE accumulation can exert stabilizing effects on matrix proteins, while scanty cell presence leads to poor capacity of reactive responses, such as remodelling and inflammation.

Preoperative risk factors for postoperative delirium (POD) after urological surgery in the elderly.

The aim of this observational study was to investigate the occurrence of postoperative delirium (POD) in elderly patients undergoing urological surgery and to identify those factors associated with delirium. Ninety consecutive patients (81 males and 9 females; average age of 74.3 ± 0.40 years), undergoing urological surgery in University-Hospital Urological Clinic were selected. Personal, medical, cognitive and functional data, biochemical parameters, preoperative medications, conduct of surgery and anesthesia and details of hemodynamic control were collected as predictors of delirium. After surgery, the subjects were divided on the basis of delirium onset within a week observation period. Delirium was diagnosed by the Confusion Assessment Method. Delirium started the first post-operative day (2F; 6 M) and lasted 3.0 ± 0.8 days. Subjects with POD were significantly older, had a previous history of delirium, were more impaired in the instrumental activities of daily living and had poorer clock drawing test (CDT) score. Interestingly, a significantly greater number of hypotensive events were recorded during anesthesia. Age, cognitive and functional status, previous history of delirium and hypotensive episodes intrasurgery are the best predictor of POD in this setting. Our findings have implications in preventing delirium in elderly by an early and targeted evaluation.

Glucagon-like peptide-1 counteracts the detrimental effects of Advanced Glycation End-Products in the pancreatic beta cell line HIT-T 15.

Advanced Glycation End-Products (AGEs), a group of compounds resulting from the non-enzymatic reaction of reducing sugars with the free amino group of proteins, are implicated in diabetic complications. We previously demonstrated that exposure of the pancreatic islet cell line HIT-T 15 to high concentrations of AGEs significantly decreases cell proliferation and insulin secretion, and affects transcription factors regulating insulin gene transcription. The glucagon-like peptide-1 (GLP-1) is an incretin hormone that increases proinsulin biosynthesis, stimulates insulin secretion, and improves pancreatic beta-cell viability. The aim of this work was to investigate the effects of GLP-1 on the function and viability of HIT-T 15 cells cultured with AGEs. HIT-T 15 cells were cultured for 5days in presence of AGEs alone, or supplemented with 10nmol/l GLP-1. Cell viability, insulin secretion, redox balance, and expression of the AGEs receptor (RAGE) were then determined. The results showed that GLP-1 protected beta cell against AGEs-induced cell death preventing both apoptosis and necrosis. Moreover, addition of GLP-1 to the AGEs culture medium restored the redox balance, improved the responsiveness to glucose, and attenuated AGEs-induced RAGE expression. These findings provide evidence that GLP-1 protects beta cells from the dangerous effects of AGEs.

Advanced glycation end-products affect transcription factors regulating insulin gene expression.

Advanced Glycation End-Products (AGEs) are generated by the covalent interaction of reducing sugars with proteins, lipids or nucleic acids. AGEs are implicated in diabetic complications and pancreatic beta-cell dysfunction. We previously demonstrated that exposure of the pancreatic islet cell line HIT-T15 to high concentrations of AGEs leads to a significant decrease of insulin secretion and content. Insulin gene transcription is positively regulated by the beta cell specific transcription factor PDX-1 (Pancreatic and Duodenal Homeobox-1). On the contrary, the forkhead transcription factor FoxO1 inhibits PDX-1 gene transcription. Activity of FoxO1 is regulated by post-translational modifications: phosphorylation deactivates FoxO1, and acetylation prevents FoxO1 ubiquitination. In this work we investigated whether AGEs affect expression and subcellular localization of PDX-1 and FoxO1. HIT-T15 cells were cultured for 5 days in presence of AGEs. Cells were then lysed and processed for subcellular fractionation. We determined intracellular insulin content, then we assessed the expression and subcellular localization of PDX-1, FoxO1, phosphoFoxO1 and acetylFoxO1. As expected intracellular insulin content was lower in HIT-T15 cells cultured with AGEs. The results showed that AGEs decreased expression and nuclear localization of PDX-1, reduced phosphorylation of FoxO1, and increased expression and acetylation of FoxO1. These results suggest that AGEs decrease insulin content unbalancing transcription factors regulating insulin gene expression.

Reliability study in five languages of the translation of the pain behavioural scale Doloplus.

Non-verbal pain assessment scales are useful tools for pain evaluation in persons with communication disorders and moderate-severe dementia. The Doloplus was one of the first scales to be developed and validated as a pain assessment tool in older adults with dementia. This study aims at evaluating the translation of the Doloplus scale in five languages, as regards test-retest and inter-rater reliability. Results show that both tests are good or excellent for the English, Italian, Portuguese and Spanish versions and moderate for the Dutch version. These results bring a unique opportunity to include the translated Doloplus scale in daily assessment of elderly persons with communication disorders, and future studies should focus on enriching the validation of the scale in each language.

The epidemiology of domestic injurious falls in a community dwelling elderly population: an outgrowing economic burden.

In Italy, more than 3 million people annually sustain a domestic injury; the elderly experience it the most. From a healthcare perspective, elderly falls are a major clinical issue with an outgrowing socioeconomic burden. The aim of the study was to evaluate the epidemiology of injurious falls in a community dwelling population, admitted to the emergency room (ER) because of a domestic injury, to assess the socioeconomic burden. Seventy-four hospitalized patients among 227 were examined. Falls represented the main cause of admittance to the ER; the average cost for fall-related hospitalization was of €5479.09.

Correlation between pentosidine and endothelin-1 in subjects undergoing chronic hemodialysis.

Advanced glycation end-products (AGEs), which accumulate in the blood and tissues of patients with chronic renal failure (CRF) undergoing chronic hemodialysis, play an important role in the pathogenesis of uremic complications. Endothelin 1 (ET1), a 21-amino acid peptide with vasoconstricting and mitogenic properties, is an important factor in the endothelial dysfunction occurring in uremia. The circulating levels of both AGEs and ET1 have been reported to be increased in chronic renal failure. In the present study we evaluated the possible relationship between pentosidine and ET1 plasma levels in CRF patients undergoing chronic hemodialysis treatment. The plasma concentrations of "free" and bound pentosidine (HPLC methods) and endothelin-1 (RIA method) were measured before the hemodialysis session in 40 nondiabetic CRF patients (22 males and 18 females; 54+/-3 years) on chronic hemodialysis for at least 1 year. Forty age- and sex-matched normal subjects served as a control group. In hemodialyzed patients, the overall pentosidine residues and pentosidine-free adduct plus pentosidine-free adduct bound reversibly to protein levels (24.9+/-2.04 pmol/mg protein and 110.5+/-5.9 pmol/ml, respectively) were significantly higher than those recorded in normal subjects (2.0+/-0.2 pmol/mg protein and 0.7+/-0.2 pmol/ml, respectively ). Endothelin-1 was also significantly (p<0.01) increased in CRF patients (10.6+/-0.4 pmol/ml in CRF patients and 2.7+/-0.3 pmol/ml in normal subjects). A significant positive correlation (p<0.01) was seen between "total" pentosidine (pentosidine residues and pentosidine-free adduct plus pentosidine-free adduct bound reversibly to protein) levels and endothelin-1 plasma values. The correlation between pentosidine and endothelin-1 provides further evidence that some AGEs exert a detrimental effect on the vascular endothelium, thereby contributing to the hypertension and other cardiovascular damage seen in CRF patients.

Plasma levels of amyloid beta-protein 42 are increased in women with mild cognitive impairment.

BACKGROUND: Accumulation in the brain of small aggregates of amyloid beta-protein 42 (Abeta42) is the major pathogenic event of Alzheimer disease (AD). In familial early-onset AD this event is likely the result of Abeta42 overproduction; in the most common sporadic late-onset form of the disease the mechanisms of Abeta42 accumulation are unknown. METHODS: To address this issue the authors analyzed plasma levels of Abeta42 in 88 elderly patients with amnestic mild cognitive impairment (MCI), chosen as paradigm of preclinical sporadic AD. RESULTS: The authors found a significant increase of Abeta42 plasma levels in women with MCI, in comparison to the affected men and 72 cognitively normal age-matched subjects. The levels were independent of variables in education, apolipoprotein E genotype, cholesterol, and creatinine plasma concentrations, as well as hemoglobin content. CONCLUSIONS: The elevation of Abeta42 plasma levels in women with MCI may represent a biologic explanation for the sex-dependent increased incidence of late-onset AD in women identified by epidemiologic studies.

Damaging effects of advanced glycation end-products in the murine macrophage cell line J774A.1.

The interaction of reducing sugars, such as aldose, with proteins and the subsequent molecular rearrangements, produces irreversible advanced glycation end-products (AGEs), a heterogeneous class of non-enzymatic glycated proteins or lipids. AGEs form cross-links, trap macromolecules and release reactive oxygen intermediates. AGEs are linked to aging, and increase in several related diseases. The aim of this study was to assess, in a murine macrophage cell line, J774A.1, the effects of 48 h of exposure to glycated serum containing a known amount of pentosidine, a well-known AGE found in the plasma and tissues of diabetic and uremic subjects. Fetal bovine serum was incubated with ribose (50 mM) for 7 days at 37 degrees C to obtain about 10 nmol/ml of pentosidine. The cytotoxic parameters studied were cell morphology and viability by neutral red uptake, lactate dehydrogenase release and tetrazolium salt test. In the medium and in the intracellular compartment, bound and free pentosidine were evaluated by HPLC, as sensitive and specific glycative markers, and thiobarbituric acid reactive substances (TBARs), as index of the extent of lipid peroxidation. Our results confirm that macrophages are able to take up pentosidine. It is conceivable that bound pentosidine is degraded and free pentosidine is released inside the cell and then into the medium. The AGE increase in the medium was combined with an increase in TBARs, meaning that an oxidative stress occurred; marked cytotoxic effects were observed, and were followed by the release of free pentosidine and TBARs into the culture medium.

Induction of heme oxygenase 1 in liver of spontaneously diabetic rats.

It has been suggested that diabetes induces an increase in oxidative stress; the increased expression of heme-oxygenase 1 (HO-1) in liver is believed to be a sensitive marker of the stress response. The aim of this study was to examine whether diabetes is able to induce HO-1 expression in liver. The specific mRNA was amplified by RT/PCR and calibrated with amplified beta-actin mRNA. The mRNA HO-1 levels in the liver of spontaneously diabetic rats were increased by 1.8 fold compared with non diabetics; this supports the hypothesis of weak but significant oxidative damage due to chronic hyperglycaemia. This work represents the first in vivo study exploring the semi-quantitative expression of HO-1 in the liver of spontaneously diabetic rats.

Plasma protein oxidation and antioxidant defense during aging.

BACKGROUND: Oxidative stress is an important process that occurs in vivo during aging and is considered one of the main causes of molecular damage to cellular and tissue structures. These changes can accumulate in biological structures during aging. OBJECTIVE: The aim of this work is to evaluate plasma protein oxidative damage, measured as carbonyl groups content, and the concentration of some antioxidant molecules (vitamins and carotenoids) in 122 healthy volunteers (50 males and 72 females), 25 to 89 years old. RESULTS: Total plasma proteins slightly decreased with age, but the level of carbonyl groups was similar in the adult (< 65 years) and in the old, and was similar in both sexes. Plasma concentration of antioxidant molecules such as alpha-tocopherol, beta-carotene and other carotenoids, increased with age and correlated with the level of lipoproteins; plasma total cholesterol and triglycerides were significantly correlated with age as well. CONCLUSIONS: The surprisingly normal level of plasma protein carbonyl groups in our older subjects suggests two possibilities: a) the older people in our study are healthy and free from pathologies because of better protection against oxidative injury during their lifetimes, i.e., they maintained low-level oxidative damage on plasma proteins; or b) the level of carbonyl groups is normal because of the high turnover in plasma: the oxidized circulating proteins are preferentially and quickly removed; in this case oxidative damage is not discernible in plasma proteins but may proceed silently in other tissues.