Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Margarita Petermann is active.

Publication


Featured researches published by Margarita Petermann.


Journal of Parenteral and Enteral Nutrition | 1993

Controlled Trial on Nutrition Supplementation in Outpatients With Symptomatic Alcoholic Cirrhosis

Sandra Hirsch; Daniel Bunout; Pia de la Maza; Hernán Iturriaga; Margarita Petermann; Gloria Icazar; Vivian Gattás; G. Ugarte

A controlled trial on nutrition supplementation in ambulatory patients with decompensated alcoholic liver disease was carried out during 1 year. Fifty-one patients were studied; 26 were assigned to an experimental group receiving a daily supplement of 1000 kcal and 34 g of proteins given as a casein-based enteral nutrition product and 25 to a control group receiving one placebo capsule. Patients were examined in a special clinic once a month or more if required. Sixty-eight percent of patients admitted to alcohol ingestion or had alcohol in urine samples on at least one occasion. Dietary recalls showed a significantly higher protein and caloric intake in case patients subjects (p < .0001). Nine patients died during the study, three case patients and six control patients (p = NS). The frequency of hospitalizations was significantly less in the experimental group. This difference was attributed to a reduction in severe infections. Mid-arm circumference, serum albumin concentration, and hand grip strength improved earlier in case patients, although both groups had a significant improvement in these parameters. Bilirubin and aspartate aminotransferase decreased and prothrombin time increased significantly in both groups during the study period, without differences between groups. It is concluded that nutrition support decreases nutrition-associated complications in patients with alcoholic liver disease.


Journal of Parenteral and Enteral Nutrition | 2004

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

Daniel Bunout; Gladys Barrera; Sandra Hirsch; Vivien Gattas; M P de la Maza; F Haschke; Philippe Steenhout; Petra Klassen; Corinne Hager; Maritza Avendaño; Margarita Petermann; Carlos Muñoz

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.


Journal of Parenteral and Enteral Nutrition | 2002

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

Daniel Bunout; Sandra Hirsch; M P de la Maza; Carlos Muñoz; F Haschke; Philippe Steenhout; Petra Klassen; Gladys Barrera; Vivien Gattas; Margarita Petermann

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.


Journal of The American College of Nutrition | 1995

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

M P de la Maza; Margarita Petermann; Daniel Bunout; Sandra Hirsch

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.


Nutrition | 2000

Effects of supplementation with folic acid and antioxidant vitamins on homocysteine levels and LDL oxidation in coronary patients.

Daniel Bunout; Argelia Garrido; Myriam Suazo; Ronald Kauffman; Paz Venegas; Pia de la Maza; Margarita Petermann; Sandra Hirsch

Hyperhomocysteinemia is an important cardiovascular risk factor. Serum homocysteine levels are specially dependent on folate nutritional status. In addition, the oxidative modification of low-density lipoproteins (LDLs) in the endothelial microenvironment is a damaging factor that can be modified with fat-soluble antioxidant vitamins. The present study was done to assess the effect of a supplementation of folic acid and antioxidant vitamins on homocysteine levels and in vitro LDL oxidation in patients with coronary artery disease. Twenty-three patients with angiographically proven coronary artery disease were given supplements for 15 d consisting of one capsule twice a day of a multivitamin preparation containing 0.65 mg folic acid, 150 mg alpha-tocopherol, 150 mg ascorbic acid, 12.5 mg beta-carotene, and 0.4 microgram vitamin B12. Serum lipids, vitamin and homocysteine levels, and in vitro LDL oxidation were measured before and after the supplementation period. During the supplementation period, serum folate levels increased from 5.0 +/- 1.5 to 10.8 +/- 3.8 ng/mL (P < 0.001), vitamin B12 increased from 317.4 +/- 130.4 to 334.5 +/- 123.8 pg/mL (P < 0.05), and alpha-tocopherol increased from 8.2 +/- 5.1 to 13.7 +/- 7.9 mg/L (P < 0.001). Serum homocysteine levels decreased from 8.7 +/- 4.3 to 6.3 +/- 2.2 mumol/L (P < 0.001). In vitro LDL oxidation decreased from 2.6 +/- 1.1 to 1.6 +/- 1.1 nmol malondialdehyde/mg protein (P < 0.001). In comparing patients with healthy controls, basal levels of folate were lower in the patients, whereas vitamin B12, alpha-tocopherol, and homocysteine levels were similar. No changes in serum lipid levels or body weight were observed. In conclusion, a short-term supplementation with folic acid and antioxidant vitamins can reduce serum homocysteine levels and in vitro LDL oxidation in patients with coronary artery disease.


Journal of The American College of Nutrition | 1999

Nutritional Support in Alcoholic Cirrhotic Patients Improves Host Defenses

Sandra Hirsch; M. Pía de la Maza; Vivian Gattás; Gladys Barrera; Margarita Petermann; Martin Gotteland; Carlos Muñoz; Marcelo Lopez; Daniel Bunout

BACKGROUND Malnutrition is usual in patients with alcoholic liver disease and is associated with a poor outcome. Nutritional support decreases nutrition-associated complications. AIM To demonstrate that nutritional support in ambulatory alcoholic cirrhotic patients improves host defenses. METHODS Thirty-one male outpatients with alcoholic cirrhosis CHILD-PUGH B or C were included. Twenty-five subjects completed six months consuming daily a nutritional supplement (Ensure, 1000 Kcal and 35 g protein), in addition to their regular diet. At entrance and every three months, a clinical assessment, nutritional evaluation and indirect calorimetry were performed. Liver function tests and LPS-induced monocyte production of cytokines, salivary secretory IgA, lactulose/mannitol ratio and breath hydrogen tests were also measured in these intervals. Delayed cutaneous hypersensitivity and IgG and IgM antibody response to endotoxin were assessed at entrance and at the end of the study. RESULTS Patients drank 85% of the provided supplement as an average. REE, total body fat and serum albumin increased, basal breath hydrogen decreased and cellular immunity improved significantly during the follow up period (p< or =0.03). All the other parameters remained unchanged throughout the study. Six patients (16.2%) died during the study, five due to upper gastrointestinal bleeding. CONCLUSION Nutritional support in alcoholic cirrhotic patients improves nutritional status and cell mediated immunity.


Nutrition | 2000

Low serum folate but normal homocysteine levels in patients with atherosclerotic vascular disease and matched healthy controls

Daniel Bunout; Margarita Petermann; Sandra Hirsch; Pia de la Maza; Myriam Suazo; Gladys Barrera; Ronald Kauffman

Mild hyperhomocysteinemia has been considered a cardiovascular risk factor. However, recent prospective studies have not demonstrated that hyperhomocysteinemia or the underlying genetic defect on methylentetrahydrofolate reductase is associated with a higher risk of coronary or peripheral artery disease. We compared serum homocysteine, folate, and vitamin B(12) levels of patients with coronary and peripheral vascular disease with those of age- and sex-matched healthy individuals. Subjects taking multivitamins, with diabetes mellitus, or serum creatinine levels over 1.5 mg/dL were excluded from the study. Homocysteine was measured by fluorimetric high-performance liquid chromatography. Serum folate and vitamin B(12) levels were measured by an ion-capture method. We studied 32 patients with peripheral vascular disease (10 female), aged 69.6 +/- 11 y, 24 age- and sex-matched control subjects, 52 patients with coronary artery disease (7 female), aged 59.5 +/- 10.4 y, and 42 age- and sex-matched control subjects. Serum homocysteine levels were 11.7 +/- 7.4 and 9.3 +/- 4.5 micromol/L in vascular patients and in the control counterparts, respectively (not significant). The levels for coronary patients and the control counterparts were 9.0 +/- 3.9 and 8.6 +/- 3.6 micromol/L, respectively (not significant). Folate levels were 4.48 +/- 2.42 and 7.14 +/- 4.04 ng/mL in vascular patients and control subjects, respectively (P < 0.02); the levels in coronary patients and control counterparts were 5.15 +/- 1.9 and 6.59 +/- 2.49 ng/mL, respectively (P < 0.01). No differences in vitamin B(12) or tocopherol levels were observed between patients and control subjects. There were no differences in homocysteine levels, but lower serum folate levels were observed when comparing patients with atherosclerotic vascular disease and healthy control subjects.


Metabolism-clinical and Experimental | 1987

Nitrogen economy in alcoholic patients without liver disease

Daniel Bunout; Margarita Petermann; G. Ugarte; Gladys Barrera; Hernán Iturriaga

Nitrogen balance was studied in five alcoholic patients during alcohol consumption and after 1 or 2 weeks of abstinence, under metabolic ward conditions. Patients had a history of excessive ethanol intake for five years or more. They were intoxicated and otherwise asymptomatic on admission and had been drinking 150 g or more of ethanol daily, for at least one month. Subjects consumed a diet providing vitamins and minerals exceeding RDA values, 45 kcal/kg of body weight and 0.6 g/kg of proteins (as egg protein), for 33 days. During the first 11 days patients received 200 g of ethanol that were isocalorically substituted later by dietary fat and carbohydrates. The results of this study show that, in alcoholic patients while drinking and after seven days of alcohol withdrawal, nitrogen balance is significantly decreased compared to that performed after two weeks of abstinence. Ethanol metabolic rate was found to be increased, compared to controls. It was lower in four of five patients after the second week of abstinence. These results suggest that alcohol abuse increases protein requirements in chronic alcoholic patients even without histologic liver disease or clinical signs of gastroenterologic disorders.


Journal of the American Geriatrics Society | 2002

Endothelial function in healthy younger and older hyperhomocysteinemic subjects

Sandra Hirsch; Pía De La Maza; Laura Mendoza; Margarita Petermann; Andrea Glasinovic; Paola Paulinelli; Gladys Barrera; Irwin H. Rosenberg; Daniel Bunout

OBJECTIVES: To compare endothelium‐dependent vasomotor response in healthy younger and older subjects without classic cardiovascular risk factors, with high and normal fasting homocysteine (tHcy) levels.


Metabolism-clinical and Experimental | 1986

Glucose tolerance and the insulin response in recently drinking alcoholic patients: possible effects of withdrawal.

Hernán Iturriaga; M. Kelly; Daniel Bunout; Pino Me; Tamara Pereda; R. Barrera; Margarita Petermann; G. Ugarte

To investigate possible effects of withdrawal on carbohydrate metabolism in chronic alcoholic patients, intravenous glucose tolerance tests were performed in three periods in 11 alcoholic patients: early abstinence (less than three days), early abstinence plus ethanol (1 g/kg/BW IV), and late abstinence (three weeks later). According to liver biopsy results and laboratory tests, patients were classified as a group with liver damage (four cases) and a group without it (seven cases). In the group without damage, glucose tolerance expressed as K% and compared to a control group, was significantly decreased in early and late abstinence but not after the infusion of ethanol. Cases with damage also had glucose intolerance at admission. Plasma insulin levels after the glucose load were significantly lower at ten and 30 minutes in the group without damage, in early or late abstinence. They were normal in the presence of ethanol. Patients with liver damage presented higher basal and postglucose plasma insulin concentrations. It was concluded that glucose intolerance in alcoholic patients is a common finding that occurs in the presence or absence of liver damage. In cases with liver damage it seems to be due to peripheral insulin resistance. In those without damage it is related to low peripherovenous insulin levels.

Collaboration


Dive into the Margarita Petermann's collaboration.

Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Researchain Logo
Decentralizing Knowledge