M P de la Maza

Effects of a nutritional supplement on the immune response and cytokine production in free-living Chilean elderly.

BACKGROUND Immune response is impaired in the elderly. Our aim was to study the effects of a special nutritional formula on the immune response and response to influenza and pneumococcal vaccination in elderly subjects. METHODS Sixty healthy subjects aged > or = 70 years, with a Mini Mental score > or = 22 were studied. Half of the subjects received a special nutritional formula (in addition to the regular diet) providing, among other nutrients, 480 kcal, 31 g proteins, 120 IU vitamin E, 3.8 microg vitamin B12, 400 microg folic acid, 10(9) cfu Lactobacillus paracasei (NCC 2461), and 6 g of fructo-oligosaccharides. At 4 months of follow-up, subjects were vaccinated against influenza and pneumococcus. Lymphokine production by mononuclear cells (PBMC), lymphocyte subpopulations, and natural killer cell (NK) activity were measured at baseline and 4 months of follow-up (before vaccination). Antibodies against influenza and pneumococcal antigens and flu-stimulated production of interferon gamma and interleukin-2 by PBMC were measured at 4 and 6 months. Skin response to 7 recall antigens and body composition were assessed at baseline and at 4 and 12 months. All infections occurring during the study period were recorded. RESULTS NK activity increased in supplemented subjects and decreased in nonsupplemented individuals. Interleukin-2 production by PBMC and the proportion of T cells with NK activity decreased in controls and did not change in supplemented subjects. Supplemented subjects reported less infections than nonsupplemented individuals (in 13% and 22% of scheduled visits, respectively; p = .02). CONCLUSIONS This nutritional supplement increased innate immunity and protection against infections in elderly people.

Effects of prebiotics on the immune response to vaccination in the elderly

BACKGROUND Prebiotics stimulate the growth of bifidogenic bacteria in the gut. The aim of this work was to assess the effects of a prebiotic mixture on the immune response in healthy elderly people. METHODS Healthy free-living elderly people (age, > or = 70 years), receiving a nutritional supplement that provided 1.6 MJ, 15 g of protein, and 50% of vitamin daily reference values per day, were randomly assigned to receive a prebiotic mixture (6 g/d of a 70% raftilose and 30% raftiline mixture) or placebo (6 g of maltodextrin powder) for 28 weeks. At week 2 of the study, all subjects were vaccinated with influenza and pneumococcal vaccines. At weeks 0, 2, and 8 of the study, serum total proteins, albumin, immunoglobulins, saliva secretory immunoglobulin A (IgA), and serum titers of influenza A and B and pneumococcal antibodies were measured. At week 8, cultured peripheral monocyte cell secretion of interleukin-4, interferon-gamma, and lymphocyte proliferation, stimulated with phytohemagglutinin and influenza antigen, were measured. RESULTS Sixty-six subjects were considered eligible for the study, and 43 (20 receiving prebiotics and 23 receiving placebo) were considered for final analyses on a per protocol basis. No changes in serum proteins, albumin, immunoglobulins, and secretory IgA were observed. Antibodies against influenza B and pneumococcus increased significantly from weeks 0 to 8, with no significant differences between groups. Antibodies against influenza A did not increase. No effects of prebiotics on interleukin-4 and interferon-gamma secretion by cultured monocytes were observed. CONCLUSIONS No immunological effects of prebiotics were observed in this study.

Effects of long-term vitamin E supplementation in alcoholic cirrhotics.

OBJECTIVE Alcohol ingestion promotes lipoperoxidation and alters cellular antioxidant mechanisms. Alpha-tocopherol levels decrease in alcoholics as severity of liver damage increases. The aim of this protocol was to study the effects of a long-term oral 500 mg vitamin E daily supplementation in decompensated ambulatory alcoholic cirrhotics. PATIENTS AND METHODS 67 subjects were included in this double blind trial; 33 patients received vitamin E and 34 patients received placebo tablets of identical appearance during 1 year. Each month, the patients were seen by a nurse practitioner who was in charge of detecting alcohol ingestion and checking adherence to treatment. Every 3 months, the patients underwent a medical examination, and blood samples were taken for clinical laboratory analysis and serum vitamin E measurement. RESULTS Alpha-tocopherol levels were significantly lower in patients with more severe liver disease. This difference was not significant when vitamin E levels were corrected by cholesterol. Oral supplementation significantly increased serum vitamin E levels in the experimental group. Alcohol ingestion and hospitalization rates were similar in both groups. Life table analysis did not show significant differences in mortality between the two groups. DISCUSSION Vitamin E supplementation with adequate doses of an alpha-tocopheryl acetate formulation during 1 year did not influence hepatic laboratory parameters, mortality or hospitalization rates of decompensated alcoholic cirrhotics, although serum levels of the vitamin significantly increased.

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

INTRODUCTION Advanced glycation end products are produced endogenously, in association with hyperglycemia and oxidative stress. They can also be generated during cooking or food processing and, once absorbed, alter protein function and promote inflammation. METHODS We selected 40 healthy male subjects, 17 patients with type 2 diabetes of both sexes and 15 patients with type 1 diabetes of both sexes. Each participant underwent both a food frequency questionnaire (FFQ) and 24-hour dietary recall specially adapted for measuring CML intake, anthropometry, measurement of blood pressure and biochemical parameters in blood and urine. RESULTS Serum CML levels were significantly higher in patients with diabetes compared to healthy subjects (p 0.04), showing a direct relationship between dietary intake and serum levels of CML in T2D patients (r 0.53 p 0.03). sCML levels correlated positively with length of diabetes mellitus, and inversely with body mass index (BMI). The most important dietary factor contributing to raise CML levels in these patients with diabetes was the consumption of milk powder. CONCLUSION Serum levels of CML were found to be higher among diabetic subjects, associated to length of diabetes as expected, but also with the ingestion of foods containing higher amounts of ML. The consumption of milk powder in this group is a major determinant of increased serum levels.

Protein turnover in abstinent and non-abstinent patients with alcoholic cirrhosis.

OBJECTIVE This study was designed to measure the effect of chronic alcohol intake on leucine turnover in outpatients with stable alcoholic liver cirrhosis. METHODS Protein turnover rate was measured using L [1-14C] leucine in ten outpatients with proven alcoholic cirrhosis and in five healthy controls. After the performance of the turnover, the patients were divided in two groups depending on the evidence of alcohol ingestion in the previous month. RESULTS Non-abstinent patients had a significantly higher leucine flux and non-oxidative disposal (73.8 +/- 25.4 and 65.9 +/- 21.6) than abstinent cirrhotic patients (48.9 +/- 9.5 and 43.7 +/- 9.0) and normal controls 37.3 +/- 8.9 and 31.1 +/- 7.6 mumol/m2/min (p < 0.01). Leucine oxidation and serum leucine levels were similar in the three groups. CONCLUSION Alcohol intake in alcoholic cirrhotic patients has a catabolic effect that could be associated with the nutritional imbalances observed in alcoholic liver disease.

Proliferation and differentiation of human adipocyte precursor cells: differences between the preperitoneal and subcutaneous compartments.

Human adipocyte precursor cells (APC) have been characterized in their proliferation and differentiation potential from subcutaneous, omental, and mesenteric depots, mostly from morbidly obese patients. Cells from the preperitoneal adipose compartment have not been characterized yet, least of all when obtained from normal weight subjects. The aim was to compare proliferation and differentiation of subcutaneous (SC) and preperitoneal (PP) APC derived from adipose tissue in healthy subjects with different body mass. SC and PP adipose tissue was obtained during surgery of inguinal hernias in five healthy non‐obese subjects and three obese otherwise healthy men. APC, obtained by collagenase digestion, were cultured. Proliferation was assayed by cell counting and differentiation by oil red O staining and flow cytometry using Nile Red staining. Proliferation of SC was higher than PP APC. Such differences between both compartments were even higher in APC obtained from obese patients. Conversely PP APC differentiated earlier in vitro compared with SC cells. These results agree with published data on fat cell proliferation. However regarding differentiation, our data show that APC from deeper depots (in this case PP) differentiate earlier than subcutaneous APC. This is different to previous studies performed in mesenteric or omental adipose tissue. J. Cell. Biochem. 111: 659–664, 2010.

Functional changes in the gastrointestinal system.

Aging is associated with a higher risk for nutritional deficiencies which cause adverse functional consequences. Functional and anatomic changes in the gastrointestinal system could explain part of the nutritional alterations observed in the elderly. However, for every study that indicates a decline in gastrointestinal tract efficiency with advancing age, there is another that argues for no age-related effect. Consequently, despite the vast number of studies conducted on this issue, there is no consensus whether healthy old individuals have a reduced capacity for nutrient assimilation.