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Biomedical subjects

G Barrera

Publications and source records attributed to G Barrera.

At least 19 recordsLinked to original sources
PubMed2004

Effects of nutritional supplementation and resistance training on muscle strength in free living elders. Results of one year follow.

PURPOSE: To assess the effects of a one year nutritional supplementation and resistance training program on muscle strength and walking capacity in the elderly. MATERIAL AND METHODS: Elderly subjects from two outpatient clinics received a nutritional supplement, that provided 400 Kcal, 15 g/protein and 50% of vitamin DRVs per day. Half the subjects receiving and not receiving the supplement were randomly assigned to a resistance exercise training program with two sessions per week. Every six months, body composition using DEXA, limb muscle strength, maximal inspiratory and expiratory pressures and walking capacity were assessed. RESULTS: One hundred forty nine subjects were considered eligible and 101 (31 supplemented and trained, 28 supplemented, 16 trained and 26 without supplementation nor training) completed the year of follow up. Overall compliance with the supplement was 48 22 % and trained subjects attended 56 21% of programmed sessions. No changes in fat free mass were observed in any of the groups, but fat mass increased from 22.5 7.3 to 23.2 7.3 kg in all groups (p < 0.001). Upper and lower limb strength and walking capacity increased significantly in trained subjects whether supplemented or not. Maximal inspiratory pressure and right hand grip strength increased only in the supplemented and trained group. CONCLUSIONS: Resistance training improved muscle strength and walking capacity.

Aged↗
PubMed2004

Lean and fat mass as determinants of muscle strength and insulin sensitivity in Chilean elderly subjects.

PURPOSE: To report the association of lean body mass with nutritional, social and economic factors and its functional consequences in free living healthy elderly subjects. MATERIAL AND METHODS: Healthy elderly subjects of low socioeconomic level were studied. Monthly income, marital status, anthropometric measures and fall risk were assessed. Mini Nutritional Assessment score was calculated. Body composition and bone mineral density were measured by double beam X ray absorptiomentry. Fasting serum lipids, fasting and postprandial insulin and glucose levels were measured. Hand grip, quadriceps and biceps strengths and maximal inspiratory and expiratory pressures were measured. RESULTS: One hundred and nine subjects (56 women), aged 75 +/- 4 years old were studied. Lean body mass was 34.1 +/- 4 and 49.2 +/- 5.4 kg in women and men respectively (p < 0.001), fat mass was 22.8 +/- 7.1 and 20.7 +/- 6.4 kg in women and men respectively (p= NS). Lean body mass correlated with hand grip, quadriceps and biceps muscle strengths in men and with quadriceps and biceps strength in women. Men that exercised regularly had higher quadriceps strength and maximal expiratory pressure. Total body fat correlated positively with fasting and postprandial serum insulin levels. CONCLUSIONS: In this sample, lean body mass is directly related to muscle strength mostly in men. On the other hand, total fat mass is related to serum insulin levels.

Absorptiometry, Photon↗
PubMed2001

Growth inhibition and differentiation induction in murine erythroleukemia cells by 4-hydroxynonenal.

4-Hydroxynonenal (HNE) is one of the major end products of lipid peroxidation. Here we show that the exposure of murine erythroleukemia (MEL) cells to 1 microM HNE, for 10.5 h over 2 days, induces a differentiation comparable with that observed in cells exposed to DMSO for the whole experiment (7 days). The exposure of MEL cells for the same length of time demonstrates a higher degree of differentiation in HNE-treated than in DMSO-treated MEL cells. The protooncogene c-myc is down-modulated early, in HNE-induced MEL cells as well as in DMSO-treated cells. However, ornithine decarboxylase gene expression first increases and then decreases, during the lowering of the proliferation rate. These findings indicate that HNE, at a concentration physiologically found in many normal tissues and in the plasma, induces MEL cell differentiation by modulation of specific gene expression.

Aldehydes↗
PubMed2001

The impact of nutritional supplementation and resistance training on the health functioning of free-living Chilean elders: results of 18 months of follow-up.

Body composition changes and loss of functionality in the elderly are related to substandard diets and progressive sedentariness. The aim of this study was to assess the impact of an 18-mo nutritional supplementation and resistance training program on health functioning of elders. Healthy elders aged > or = 70 y were studied. Half of the subjects received a nutritional supplement. Half of the supplemented and nonsupplemented subjects were randomly assigned to a resistance exercise training program. Every 6 mo, a full assessment was performed. A total of 149 subjects were considered eligible for the study and 98 (31 supplemented and trained, 26 supplemented, 16 trained and 25 without supplementation or training) completed 18 mo of follow-up. Compliance with the supplement was 48%, and trained subjects attended 56% of programmed sessions. Activities of daily living remained constant in the supplemented subjects and decreased in the other groups. Body weight and fat-free mass did not change. Fat mass increased from 22.2 +/- 7.6 to 24.1 +/- 7.7 kg in all groups. Bone mineral density decreased less in both supplemented groups than in the nonsupplemented groups (ANOVA, P < 0.01). Serum cholesterol remained constant in both supplemented groups and in the trained groups, but it increased in the control group (ANOVA, P < 0.05). Upper and lower limb strength, walking capacity and maximal inspiratory pressure increased in trained subjects. In conclusion, patients who were receiving nutritional supplementation and resistance training maintained functionality, bone mineral density and serum cholesterol levels and improved their muscle strength.

Aged↗
PubMed2001

[Biological, familial and metabolic characteristics of infantile and juvenile obesity].

BACKGROUND: Obesity is the most prevalent nutritional disease in people of less than 20 years old. AIM: To report biological, familial and metabolic characteristics in obese children. PATIENTS AND METHODS: A retrospective review of 187 children seen at obesity clinics and that had a complete metabolic study. RESULTS: Ninety five prepuberal and 92 puberal children, aged 8.7 +/- 2.2 and 12.6 +/- 2.2 years old respectively, were studied. Body mass index was over 4 standard deviations in 48.4% of prepuberal children and in 39.1% of puberal children. Paternal obesity was twice more prevalent (30.2%) than in the general population. The daily caloric intake and basal metabolic rate (BMR) were within the normal range; nevertheless there was a positive caloric balance due to minimal physical activity. The mean daily fat intake was normal (26.4 +/- 8.5 and 25.3 +/- 9.1% of total calories in prepuberal and puberal children respectively). The daily fiber intake was under 70% of recommendation. The total cholesterol was over 200 mg/dl in 26.6 and 23.9% of prepuberal and puberal children. LDL cholesterol was over 130 mg/dl in 27.3 and 26.6% and triacylglycerol was over 150 mg/dl in 16.9 and 25% of prepuberal and puberal children respectively. Basal serum insulin was over 20 uIU/ml in 27.7 and 42.2% of prepuberal and puberal children, respectively. Post glucose serum insulin was over 60 uIU/ml in 40 and 63% of prepuberal and puberal children, respectively. CONCLUSIONS: Infantile and juvenile obesity is a chronic disease with a high incidence of metabolic alterations.

Adolescent↗
PubMed2000

4-Hydroxynonenal-induced MEL cell differentiation involves PKC activity translocation.

4-Hydroxynonenal (HNE) is a highly reactive aldehyde, produced by cellular lipid peroxidation, able to inhibit proliferation and to induce differentiation in MEL cells at concentrations similar to those detected in several normal tissues. Inducer-mediated differentiation of murine erythroleukemia (MEL) cells is a multiple step process characterized by modulation of several genes as well as by a transient increase in the amount of membrane-associated protein kinase C (PKC) activity. Here we demonstrate that a rapid translocation of PKC activity from cytosol to the membranes occurs during the differentiation induced by HNE. When PKC is completely translocated by phorbol-12-myristate-13-acetate (TPA), the degree of HNE-induced MEL cells differentiation is highly decreased. However, if TPA is washed out from the culture medium before the exposition to the aldehyde, HNE gradually resumes its differentiative ability. The incubation of cells with a selective inhibitor of PKC activity, bisindolylmaleimide GF 109203X, partially prevents the HNE-induced differentiation in MEL cells. In conclusion, our results demonstrate that HNE-induced MEL cell differentiation is preceded by a rapid translocation of PKC activity, and that the inhibition of this phenomenon prevents the onset of terminal differentiation.

Aldehydes↗
PubMed2000

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

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.

Aged↗
PubMed2000

Effect of bioactive aldehydes on cell proliferation and c-myc expression in HL-60 human leukemic cells.

Lipid peroxidation produces several toxic carbonyls, including biologically active aldehydes. In previous studies, we demonstrated that 4-hydroxynonenal (HNE), one of the major products of lipoperoxidation, inhibited growth and c-myc expression in K562 and HL-60 human leukemic cells. In this study, we compared the HNE effects with those of 4-hydroxyoctenal (HOE), 4-hydroxyundecenal (HUE; different lengths of the lipophilic tail), and the analogous aldehydes 2-trans-nonanal (lacking the OH group) and nonenal (lacking the OH group and the trans CC double bond), on HL-60 cell proliferation and c-myc expression. HUE and HOE inhibited growth and c-myc expression in a dose-dependent fashion, with an effectiveness comparable with that of HNE, whereas 2-nonenal and nonanal did not affect these parameters. Our results showed that different aldehydes produced from lipid peroxidation may contribute to growth inhibition by c-myc downregulation and that the molecular features involved seem to be the hydroxy group and the trans CC double bond.

Aldehydes↗
PubMed1999

Inhibition of D1, D2, and A-cyclin expression in HL-60 cells by the lipid peroxydation product 4-hydroxynonenal.

4-Hydroxynonenal (HNE), a product of lipid peroxidation, is an highly reactive aldehyde that, at concentration similar to those found in normal cells, blocks proliferation and induces a granulocytic-like differentiation in HL-60 cells. These effects are accompained by a marked increase in the proportion G0/G1 cells. The mechanisms of HNE action were investigated by analyzing the expression of the cyclins and cyclin-dependent protein kinases (CDKs), controlling the cell cycle progression. Data obtained by exposing cells to dimethyl sulfoxide (DMSO) were used for comparison. 4-Hydroxynonenal downregulated both mRNA and protein contents of cyclins D1, D2, and A until 24 h from the treatments, whereas DMSO inhibited cyclin D1 and D2 expression until the end of experiment (2 days) and induces an increase of cyclin A until 1 day. Cyclins B and E, and protein kinase CDK2 and CDK4 expressions were not affected by HNE, whereas DMSO induced an increase of cyclin E, B, and CDK2 from 8 h to 1 day. These data are in agreement with previous results indicating a different time-course of accumulation in G0/G1 phases of cells treated with HNE and DMSO and suggest that the HNE inhibitory effect on proliferation and cell cycle progression may depend by the downregulation of D1, D2, and A cyclin expression.

Aldehydes↗
PubMed1999

Nutritional support in alcoholic cirrhotic patients improves host defenses.

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.

Adipose Tissue↗
PubMed1999

4-Hydroxynonenal as a biological signal: molecular basis and pathophysiological implications.

Reactive oxygen intermediates (ROI) and other pro-oxidant agents are known to elicit, in vivo and in vitro, oxidative decomposition of omega-3 and omega-6 polyunsaturated fatty acids of membrane phospholipids (i.e, lipid peroxidation). This leads to the formation of a complex mixture of aldehydic end-products, including malonyldialdehyde (MDA), 4-hydroxy-2,3-nonenal (HNE), and other 4-hydroxy-2,3-alkenals (HAKs) of different chain length. These aldehydic molecules have been considered originally as ultimate mediators of toxic effects elicited by oxidative stress occurring in biological material. Experimental and clinical evidence coming from different laboratories now suggests that HNE and HAKs can also act as bioactive molecules in either physiological and pathological conditions. These aldehydic compounds can affect and modulate, at very low and nontoxic concentrations, several cell functions, including signal transduction, gene expression, cell proliferation, and, more generally, the response of the target cell(s). In this review article, we would like to offer an up-to-date review on this particular aspect of oxidative stress--dependent modulation of cellular functions-as well as to offer comments on the related pathophysiological implications, with special reference to human conditions of disease.

Aldehydes↗
PubMed1999

[Nutritional status and energy expenditure in elders of differing socioeconomic level].

BACKGROUND: Income and socioeconomic status can influence nutritional status of individuals. Since elders are a more vulnerable group to nutritional deficiencies, socioeconomic status could have a special relevance on nutrition of elderly people. AIM: To assess the influence of socioeconomic status on the nutritional status of elders. MATERIAL AND METHODS: Elders of both sexes of high socioeconomic level and age and sex matched elders of low socioeconomic status were studied. Anthropometry, body composition using double beam X ray absorptiometry, resting energy expenditure using an open circuit indirect calorimeter, routine biochemistry, blood levels of folic acid, vitamin B12 and homocysteine were measured in all subjects. RESULTS: Fourteen female elders of high socioeconomic level, 14 females of low level and 12 males of each level were studied. Mean age of females and males was 71.5 +/- 3.7 and 73.9 +/- 4.2 years old respectively. Males and females of high socioeconomic status were taller than their counterparts of low status. Females of high socioeconomic status had a lower body mass index than their pairs of low status (26.3 +/- 3.8 and 30.2 +/- 5.6 kg/m2 respectively p < 0.02). Men of high economic status had a higher fat mass than their pairs of low level (20.3 +/- 3.5 and 15.1 +/- 5.5 kg respectively, p < 0.005). No differences in resting energy expenditure in women of differing socioeconomic level were observed. Men of high level had a higher energy expenditure that their counterparts of low level (36.0 +/- 4.9 and 32.8 +/- 2.2 Kcal/kg lean body mass/day respectively, p < 0.02). Low level male elders had higher serum total cholesterol and triglycerides. Folic acid, vitamin B12 and homocysteine levels were within normal limits. Dietary intake showed deficiencies in calorie, protein and vitamin intake in all subjects. CONCLUSIONS: In this group of elders, low socioeconomic level did not produce a significant impact on nutritional status.

Absorptiometry, Photon↗
PubMed1999

4-Hydroxy-2,3-nonenal as a signal for cell function and differentiation.

4-Hydroxy-2,3-nonenal (HNE) is a biologically active aldehydic end product of oxidative decomposition of omega-3 and omega-6 polyunsaturated fatty acids of membrane phospholipids, a process referred to as lipid peroxidation. HNE has been detected in several experimental and clinical conditions in which oxidative stress has been reported to occur and several authors have suggested that HNE and related 4-hydroxy-2,3-alkenals (HAKs) of different chain length may act not only as toxic and mutagenic mediators of oxidative stress-related injury but also as biological signals in normal and pathological conditions. In this paper we will review the literature supporting the concept that HNE and HAKs may act as signal molecules able to modulate biological events such as chemotaxis, signal transduction, gene expression, cell proliferation and cell differentiation.

Aldehydes↗
PubMed1998

[Quality control of bone densitometry: precision, reproducibility, and clinical application].

Dual energy x-ray absorptiometry (DEXA) is one of the most widely used methods for bone mineral density (BMD), total body mass (TBM), total body fat (TBF), percentage of total body fat (%TBF) and total body fat-free mass (TBFFM) measurements. We investigated the in vitro and in vivo accuracy and precision of DEXA in repeated measurements of a lumbar spine phantom and in 30 healthy volunteers. Based on precision, the minimal significant variability (MSV) at 95% confidence level between 2 measurements of the same object or subject was calculated. In vitro accuracy and MSV were 99.8 and 0.9% respectively. In vivo indexes were 99.4 and 0.9% for whole-body BMD, 98.6 and 2% for lumbar spine BMD, 96.6 and 4.8% for femoral neck BMD, 98 and 2.8% for major trochanter BMD, 96 and 5.7% for Ward's triangle BMD, 99.5 and 0.7% for TBM, 98 and 2.9% for TBF, 97.9 and 3% for %TBF and 99 and 1.4% for TBFFM. Our findings indicate that DEXA is a very reliable instrument and in order to be 95% confident of a real change between 2 scans a difference of at least the calculated MSV must be measured.

Absorptiometry, Photon↗
PubMed1996

4-hydroxynonenal specifically inhibits c-myb but does not affect c-fos expressions in HL-60 cells.

4-Hydroxynonenal, an aldehyde produced from lipid peroxidation of cellular membranes, inhibits growth and induces differentiation of HL-60 human leukemic cell line. Since it is highly unstable in the culture medium, its effectiveness is increased when added repeatedly to the cell suspension. We have previously demonstrated that HNE inhibits c-myc but not N-ras expression in HL-60 cells. Here we investigate its effect on the expression of c-myb and c-fos, two early genes involved in the induction of myeloid and monocytic differentiation. Moreover, since c-fos is directly correlated with the intracellular level of cAMP, we also analysed the cAMP concentration after aldehyde treatment. HNE significantly inhibits c-myb expression during and after repeated treatments. A single administration of 1 microM HNE decreases c-myb mRNA at 1 hour whereas 10 microM HNE inhibits c-myb expression from 3 to 6 hours after treatment, and then the expression returns to the control level. By contrast, c-fos expression and intracellular cAMP concentration do not show any significant change after HNE treatments.

Aldehydes↗
PubMed1996

Enzymatic pattern of aldehyde metabolism during HL-60 cell differentiation.

A number of metabolic changes, including modification of different enzyme activities, are linked to the acquisition of differentiated phenotype in HL-60 cells. Enzymes metabolizing aldehydes contribute to maintaining the intracellular steady-state concentration of aldehydes derived from lipid peroxidation. 4-Hydroxynonenal is one of the most important aldehydes produced by this process, and it is able to inhibit proliferation and induce differentiation of HL-60 human leukemic cells. We have now demonstrated that, after induction of HL-60 cell differentiation by 4-hydroxynonenal or DMSO, glutathione transferase activity increases in parallel to the degree of differentiation induction. Moreover, in 4-hydroxynonenal- or DMSO-treated cells, the concentration of reduced glutathione decreases five days after treatment. The rise of glutathione transferase activity, as well as the decrease of reduced glutathione, are possibly linked to the increase of detoxification capability of differentiated cells.

Alcohol Dehydrogenase↗
PubMed1996

Effect of 4-Hydroxynonenal on cell cycle progression and expression of differentiation-associated antigens in HL-60 cells.

4-Hydroxynonenal (HNE) is a highly reactive aldehyde produced by lipid peroxidation of cellular membranes that inhibits growth and induces differentiation in HL-60 cells. Its mechanisms of action were investigated by analyzing the cell cycle distribution and the appearance of differentiated phenotypes in HL-60 cells. Data obtained by exposing cells to DMSO for 7.5 h (same time as for HNE treatment) or for the whole length of the experiments (5 d) were used for comparison. HNE induced a marked increase in the proportion of G0/G1 cells after 1 and 2 d. The brief DMSO treatment did not affect the distribution, whereas continuous exposure led to a progressive accumulation of cells in G0/G1 (maximal at day 5). The proportion of phagocytic cells gradually increased in HNE-treated and DMSO long-exposed cultures from day 2 and peaked at day 5 (35 and 63%, respectively), whereas the effect of the brief DMSO treatment was negligible. The expression of CD11b and CD67 increased in cells treated with HNE or continuously exposed to DMSO, whereas CD36 was expressed at low levels on both treatments. These results indicate that the pathway of the granulocytic differentiation induced by HNE in HL-60 cells differs from that of DMSO: with HNE, growth inhibition precedes the onset of differentiation, whereas in DMSO-treated cells the two processes are chronologically associated.

Aldehydes↗