Assessment of indicators of vitamin A status in non-cirrhotic chronic hepatitis C patients.

Subjects with chronic liver disease are susceptible to hypovitaminosis A due to several factors. Therefore, identifying patients with vitamin deficiency and a requirement for vitamin supplementation is important. Most studies assessing vitamin A in the context of hepatic disorders are conducted using cirrhotic patients. A cross-sectional study was conducted in 43 non-cirrhotic patients with chronic hepatitis C to evaluate markers of vitamin A status represented by serum retinol, liver retinol, and serum retinol-binding protein levels. We also performed the relative dose-response test, which provides an indirect estimate of hepatic vitamin A reserves. These vitamin A indicators were assessed according to the stage of liver fibrosis using the METAVIR score and the body mass index. The sample study was predominantly composed of male subjects (63%) with mild liver fibrosis (F1). The relative dose-response test was <20% in all subjects, indicating vitamin A sufficiency. Overweight or obese patients had higher serum retinol levels than those with a normal body mass index (2.6 and 1.9 µmol/L, respectively; P<0.01). Subjects with moderate liver fibrosis (F2) showed lower levels of serum retinol (1.9 vs 2.5 µmol/L, P=0.01) and retinol-binding protein levels compared with those with mild fibrosis (F1) (46.3 vs 67.7 µg/mL, P<0.01). These results suggested an effect of being overweight on serum retinol levels. Furthermore, more advanced stages of liver fibrosis were related to a decrease in serum vitamin A levels.

Assessment of indicators of vitamin A status in non-cirrhotic chronic hepatitis C patients

Subjects with chronic liver disease are susceptible to hypovitaminosis A due to several factors. Therefore, identifying patients with vitamin deficiency and a requirement for vitamin supplementation is important. Most studies assessing vitamin A in the context of hepatic disorders are conducted using cirrhotic patients. A cross-sectional study was conducted in 43 non-cirrhotic patients with chronic hepatitis C to evaluate markers of vitamin A status represented by serum retinol, liver retinol, and serum retinol-binding protein levels. We also performed the relative dose-response test, which provides an indirect estimate of hepatic vitamin A reserves. These vitamin A indicators were assessed according to the stage of liver fibrosis using the METAVIR score and the body mass index. The sample study was predominantly composed of male subjects (63%) with mild liver fibrosis (F1). The relative dose-response test was <20% in all subjects, indicating vitamin A sufficiency. Overweight or obese patients had higher serum retinol levels than those with a normal body mass index (2.6 and 1.9 µmol/L, respectively; P<0.01). Subjects with moderate liver fibrosis (F2) showed lower levels of serum retinol (1.9 vs 2.5 µmol/L, P=0.01) and retinol-binding protein levels compared with those with mild fibrosis (F1) (46.3 vs 67.7 µg/mL, P<0.01). These results suggested an effect of being overweight on serum retinol levels. Furthermore, more advanced stages of liver fibrosis were related to a decrease in serum vitamin A levels.

Efficacy of the dietary histone deacetylase inhibitor butyrate alone or in combination with vitamin A against proliferation of MCF-7 human breast cancer cells

The combined treatment with histone deacetylase inhibitors (HDACi) and retinoids has been suggested as a potential epigenetic strategy for the control of cancer. In the present study, we investigated the effects of treatment with butyrate, a dietary HDACi, combined with vitamin A on MCF-7 human breast cancer cells. Cell proliferation was evaluated by the crystal violet staining method. MCF-7 cells were plated at 5 x 10(4) cells/mL and treated with butyrate (1 mM) alone or combined with vitamin A (10 µM) for 24 to 120 h. Cell proliferation inhibition was 34, 10 and 46% following treatment with butyrate, vitamin A and their combination, respectively, suggesting that vitamin A potentiated the inhibitory activities of butyrate. Furthermore, exposure to this short-chain fatty acid increased the level of histone H3K9 acetylation by 9.5-fold (Western blot), but not of H4K16, and increased the expression levels of p21WAF1 by 2.7-fold (Western blot) and of RARβ by 2.0-fold (quantitative real-time PCR). Our data show that RARβ may represent a molecular target for butyrate in breast cancer cells. Due to its effectiveness as a dietary HDACi, butyrate should be considered for use in combinatorial strategies with more active retinoids, especially in breast cancers in which RARβ is epigenetically altered.

Genetic polymorphisms modulate the folate metabolism of Brazilian individuals with Down syndrome.

Individuals with Down syndrome (DS) carry three copies of the Cystathionine ß-synthase (CßS) gene. The increase in the dosage of this gene results in an altered profile of metabolites involved in the folate pathway, including reduced homocysteine (Hcy), methionine, S-adenosylhomocysteine (SAH) and S-adenosylmethionine (SAM). Furthermore, previous studies in individuals with DS have shown that genetic variants in genes involved in the folate pathway influence the concentrations of this metabolism's products. The purpose of this study is to investigate whether polymorphisms in genes involved in folate metabolism affect the plasma concentrations of Hcy and methylmalonic acid (MMA) along with the concentration of serum folate in individuals with DS. Twelve genetic polymorphisms were investigated in 90 individuals with DS (median age 1.29 years, range 0.07-30.35 years; 49 male and 41 female). Genotyping for the polymorphisms was performed either by polymerase chain reaction (PCR) based techniques or by direct sequencing. Plasma concentrations of Hcy and MMA were measured by liquid chromatography-tandem mass spectrometry as previously described, and serum folate was quantified using a competitive immunoassay. Our results indicate that the MTHFR C677T, MTR A2756G, TC2 C776G and BHMT G742A polymorphisms along with MMA concentration are predictors of Hcy concentration. They also show that age and Hcy concentration are predictors of MMA concentration. These findings could help to understand how genetic variation impacts folate metabolism and what metabolic consequences these variants have in individuals with trisomy 21.

Efficacy of the dietary histone deacetylase inhibitor butyrate alone or in combination with vitamin A against proliferation of MCF-7 human breast cancer cells.

The combined treatment with histone deacetylase inhibitors (HDACi) and retinoids has been suggested as a potential epigenetic strategy for the control of cancer. In the present study, we investigated the effects of treatment with butyrate, a dietary HDACi, combined with vitamin A on MCF-7 human breast cancer cells. Cell proliferation was evaluated by the crystal violet staining method. MCF-7 cells were plated at 5 x 10(4) cells/mL and treated with butyrate (1 mM) alone or combined with vitamin A (10 µM) for 24 to 120 h. Cell proliferation inhibition was 34, 10 and 46% following treatment with butyrate, vitamin A and their combination, respectively, suggesting that vitamin A potentiated the inhibitory activities of butyrate. Furthermore, exposure to this short-chain fatty acid increased the level of histone H3K9 acetylation by 9.5-fold (Western blot), but not of H4K16, and increased the expression levels of p21WAF1 by 2.7-fold (Western blot) and of RARß by 2.0-fold (quantitative real-time PCR). Our data show that RARß may represent a molecular target for butyrate in breast cancer cells. Due to its effectiveness as a dietary HDACi, butyrate should be considered for use in combinatorial strategies with more active retinoids, especially in breast cancers in which RARß is epigenetically altered.

Proinflammatory and oxidative stress markers in patients submitted to Roux-en-Y gastric bypass after 1 year of follow-up.

BACKGROUND/OBJECTIVES: This study examined the effect of weight loss after 3, 6 and 12 months of Roux-en-Y Gastric Bypass (RYGB) on energy intake and on several biomarkers of oxidative stress such as levels of vitamin C, beta-carotene, vitamin E (diet/blood), nitric oxide metabolites (NOx), myeloperoxidase (MPO), thiobarbituric acid reactive substances (TBARS), reduced glutathione (GSH) and activity of catalase (CAT). SUBJECTS/METHODS: Study with a control group (CG), assessed once, and a bariatric group (BG) assessed at the basal period as well as at 3, 6 and 12 months post-surgery; both groups were composed of 5 men and 31 women (n=36). Age was 38.7 ± 9.4 and 39.6 ± 9.2 years old and body mass index (BMI) was 22.2 0 ± 2.1 and 47.6 ± 9.1 kg/m(2), respectively. The variance measure quoted was SEM. RESULTS: The body weight at 12 months was 35.8 ± 1.0% (P<0.001) lower than that of the basal period. At the basal period BG showed higher levels of NOx (P=0.007) and TBARS (P<0.001) and lower levels of vitamins C and E (P<0.001) compared with CG. After 3 months the activity of MPO was decreased (P<0.001). Six months after surgery GSH levels were decreased (P=0.037), whereas CAT activity was increased (P=0.029). After 12 months levels of NOx (P=0.004), TBARS (P<0.001), beta-carotene (P<0.001) and vitamin E (P<0.001) were decreased, whereas those of vitamin C (P<0.001) were increased compared with controls. CONCLUSION: RYGB followed by a daily vitamin supplement apparently attenuated pro-inflammatory and oxidative stress markers 1 year after surgery, but additional antioxidant supplementation appears necessary.

Ausência de mutagenicidade e antimutagenicidade do extrato obtido das flores do ipê roxo [Tabebuia impetiginosa (Mart. ex DC.) Standl.] / Absence of mutagenicity and antimutagenicity of the extract obtained from the flowers of "ipê roxo" Tabebuia impetiginosa (Mart. ex DC.) Standl

A Tabebuia impetiginosa, conhecida popularmente como ipê-roxo, é uma planta nativa das florestas tropicais chuvosas da América do Sul e Central. Componentes químicos obtidos da casca têm mostrado efeito terapêutico, como antiinflamatório, antifúngico e antibacteriano. Porém, pela falta de dados na literatura, pouco se sabe sobre os efeitos do extrato das flores. Assim, o objetivo do presente trabalho foi avaliar o potencial mutagênico e antimutagênico do extrato obtido das flores da T. impetiginosa, em três diferentes concentrações (100, 300 e 500 mg kg-1 p.c.) pelo teste do micronúcleo. Para o teste de mutagenicidade, a doxorrubicina (DXR, 90 mg kg-1 p.c.) foi utilizada como indutor de danos no DNA e para o teste de antimutagenicidade, os tratamentos com o extrato foram realizados simultaneamente com este agente químico. O sangue periférico dos animais foi coletado 24 horas após os tratamentos. A comparação da frequência de eritrócitos policromáticos (PCEs) em 400 eritrócitos/animal entre os diferentes grupos não demonstrou qualquer citotoxicidade do extrato. Em relação às frequências de micronúcleos em PCEs (PCEMNs), não foram observadas diferenças significativas entre os grupos tratados com as diferentes concentrações de extrato e o controle negativo. Da mesma forma, todos os grupos de animais que receberam os tratamentos simultâneo do extrato (100, 300 ou 500 mg kg-1 p.c.) com a DXR, apresentaram valores de PCEMNs muito próximos quando comparados com os dados observados no grupo de animais que recebeu somente a DXR. Esses resultados apresentados indicam ausência de efeito mutagênico e antimutagênico do extrato obtido das flores da T. impetiginosa em sistema teste in vivo.

T. impetiginosa, known as "ipê-roxo", is a plant native to tropical rain forests of Central and South Americas. Chemical compounds obtained from its bark have shown anti-inflammatory, antifungal and antibacterial therapeutic effect. However, due to the lack of data in the literature, little is known about the effects of its flower extract. Thus, the aim of this study was to evaluate the mutagenic and antimutagenic potential of the extract obtained from T. impetiginosa flowers at three different concentrations (100, 300 and 500 mg kg-1 p.c.) by the micronucleus test. For the mutagenicity test, doxorubicin (DXR, 90 mg kg-1 p.c.) was used as DNA-damage inducer, while for the antimutagenicity test, treatments with the extract were performed simultaneously with this chemical agent. The peripheral blood of animals was collected 24 hours after the treatments. The frequency of polychromatic erythrocytes (PCEs) in 400 erythrocytes/animal was compared among the different groups and showed no extract cytotoxicity. As regards the frequency of micronuclei in PCEs (PCEMNs), there were no significant differences between the groups treated with different concentrations of extract and the negative control. Similarly, all groups of animals that received the simultaneous extract treatments (100, 300 or 500 mg kg-1 p.c.) with DXR showed very similar values of PCEMNs when compared with the data observed for the group of animals that received DXR alone. These results indicate no mutagenic and antimutagenic effect of the extract obtained from T. impetiginosa flowers in the testing system in vivo.

Impact of maternal vitamin A supplementation on the mother-infant pair in Brazil.

BACKGROUND/OBJECTIVES: Vitamin A deficiency (VAD) is a major public health problem. The supplementation of lactating women could be an effective strategy to combat it. The objective of this study was to assess the impact of maternal vitamin A supplementation on the mother-infant pair. SUBJECTS/METHODS: This was a double blind, placebo-controlled randomized clinical assay in which 33 women received 200 000 IU of vitamin A and 33 women received soy oil between 20th and 30th postpartum days. Maternal blood and milk samples were collected immediately before supplementation and 3 months after delivery, when blood was also collected from the babies. Retinol concentrations 0.70 µmol/l in serum and 1.05 µmol/l in milk were considered to indicate VAD. RESULTS: Increase in serum retinol level was observed in the supplemented group compared with the pre-supplementation levels (1.05 and 1.17 µmol/l, respectively; P=0.026) and to the post-supplementation levels of the control group (1.02 µmol/l; P=0.032). Reduction in breast milk retinol was observed in the control group compared with the pre-supplementation levels (1.93 and 1.34 µmol/l, respectively; P<0.0001) and to the post-supplementation levels of the supplemented group (1.56 µmol/l; P=0.0003). There was significant difference in the prevalence of VAD in breast milk after supplementation, 55.6% (15/27) in the control group and 16.1% (5/31) in the supplemented group (P=0.002). VAD was present in 66.1% (39/59) of infants, with mean serum retinol levels of 0.64±0.30 µmol/l in the control group and of 0.69±0.26 µmol/l in the supplemented group. CONCLUSIONS: Supplementation had a positive impact on maternal vitamin A status. No effect on infant status was detectable 2 months after supplementation with a single dose.

Water extracts of cabbage and kale inhibit ex vivo H(2)O(2)-induced DNA damage but not rat hepatocarcinogenesis.

The chemopreventive potential of water extracts of the Brassica vegetables cabbage and kale was evaluated by administering their aqueous extracts in drinking water ad libitum to Wistar rats submitted to Ito's hepatocarcinogenesis model (CB group and K group, respectively - 14 rats per group). Animals submitted to this same model and treated with water were used as controls (W group - 15 rats). Treatment with the vegetable extracts did not inhibit (P > 0.05) placental glutathione S-transferase-positive preneoplastic lesions (PNL). The number of apoptotic bodies did not differ (P > 0.05) among the experimental groups. Ex vivo hydrogen peroxide treatment of rat livers resulted in lower (P < 0.05) DNA strand breakage in cabbage- (107.6 +/- 7.8 microm) and kale- (110.8 +/- 10.0 microm) treated animals compared with control (120.9 +/- 12.7 microm), as evaluated by the single cell gel (comet) assay. Treatment with cabbage (2 +/- 0.3 microg/g) or kale (4 +/- 0.2 microg/g) resulted in increased (P < 0.05) hepatic lutein concentration compared with control (0.5 +/- 0.07 microg/g). Despite the absence of inhibitory effects of cabbage and kale aqueous extracts on PNL, these Brassica vegetables presented protection against DNA damage, an effect possibly related to increased hepatic lutein concentrations. However, it must be pointed out that the cause-effect relationship between lutein levels and protection is hypothetical and remains to be demonstrated.

Water extracts of cabbage and kale inhibit ex vivo H2O2-induced DNA damage but not rat hepatocarcinogenesis

The chemopreventive potential of water extracts of the Brassica vegetables cabbage and kale was evaluated by administering their aqueous extracts in drinking water ad libitum to Wistar rats submitted to Ito’s hepatocarcinogenesis model (CB group and K group, respectively - 14 rats per group). Animals submitted to this same model and treated with water were used as controls (W group - 15 rats). Treatment with the vegetable extracts did not inhibit (P > 0.05) placental glutathione S-transferase-positive preneoplastic lesions (PNL). The number of apoptotic bodies did not differ (P > 0.05) among the experimental groups. Ex vivo hydrogen peroxide treatment of rat livers resulted in lower (P < 0.05) DNA strand breakage in cabbage- (107.6 ± 7.8 µm) and kale- (110.8 ± 10.0 µm) treated animals compared with control (120.9 ± 12.7 µm), as evaluated by the single cell gel (comet) assay. Treatment with cabbage (2 ± 0.3 µg/g) or kale (4 ± 0.2 µg/g) resulted in increased (P < 0.05) hepatic lutein concentration compared with control (0.5 ± 0.07 µg/g). Despite the absence of inhibitory effects of cabbage and kale aqueous extracts on PNL, these Brassica vegetables presented protection against DNA damage, an effect possibly related to increased hepatic lutein concentrations. However, it must be pointed out that the cause-effect relationship between lutein levels and protection is hypothetical and remains to be demonstrated.

Double aneuploidy (48,XXY,+21) of maternal origin in a child born to a 13-year-old mother: evaluation of the maternal folate metabolism.

The occurrence of non-mosaic double trisomy is exceptional in newborns. In this paper, a 48,XXY,+21 child, the parental origin of the extra chromosomes and the evaluation of the maternal folate metabolism are presented. The infant was born to a 13-year-old mother and presented with the typical clinical features of Down syndrome (DS). The origin of the additional chromosomes was maternal and most likely resulted from errors during the first meiotic division. Molecular analysis of 12 genetic polymorphisms involved in the folate metabolism revealed that the mother is heterozygous for the MTHFR C677T and TC2 A67G polymorphisms, and homozygous for the mutant MTRR A66G polymorphism. The maternal homocysteine concentration was 4.7 miromol/L, a value close to the one considered as a risk factor for DS in our previous study. Plasma methylmalonic acid and serum folate concentrations were 0.17 micromol/L and 18.4 ng/mL, respectively. It is possible that the presence of allelic variants for the folate metabolism and Hey concentration might have favored errors in chromosomal disjunction during gametogenesis in this young mother. To our knowledge, this is the first patient with non-mosaic Down-Klinefelter born to a teenage mother, resulting from a rare fertilization event combining an abnormal 25,XX,+21 oocyte and a 23,Y spermatozoon.

Increased folate intake with no changes in serum homocysteine and decreased levels of C-reactive protein in patients with inflammatory bowel diseases.

In order to increase dietary folic acid intake and to improve nutritional status regarding folate by controlling homocysteine concentrations, ten patients with inflammatory bowel diseases (Crohn's disease in the colon and ulcerative colitis) received individualized nutritional guidance and were followed up as outpatients for 2 months. The following procedures were performed at the beginning of the study (T0), after 1 month (T1) and at the end of the study (T2): collection of anthropometric data (weight and height), dietary data (24 h diet recall), and blood under fasting condition for the determination of serum folic acid, homocysteine, C-reactive protein, and vitamin B12. Plasma folic acid deficiency was not detected but hyperhomocysteinemia was present in six individuals and C-reactive protein (CRP) was increased (>0.5 mg/dl) in seven patients. After the patients were instructed there was a significant increase in vitamin B6 intake (about 35%) and in folate intake (49.6%). Mean plasma levels of folic acid, homocysteine, and vitamin B12 did not change, but there was a significant decrease of CRP at T1, 0.36 mg dl(-1) on average (P = 0.01), which was maintained at T2. We conclude that the increased folate intake reported by this group of patients was not reflected in improved serum concentrations of folic acid and homocysteine. However, the guidelines for the patients probably induced them to choose a more adequate diet, providing nutrients that help control the inflammatory process.

Vitamin A deficiency among Brazilian school-aged children in a healthy child service.

BACKGROUND/OBJECTIVES: Vitamin A deficiency (VAD) is a world public health problem contributing to the increase in childhood morbidity and mortality in developing countries and severe deficiency of vitamin A may lead to xerophthalmia and blindness. The objective of this study was to determine the prevalence of VAD among Brazilian school-aged children attended at a primary health unit and to verify if some considered risk factor was associated with VAD in this group. SUBJECTS/METHODS: A descriptive prospective transverse study was conducted on 103 randomly selected children. A total of 54 boys and 49 girls aged 5.5-11 years had the relative dose-response (RDR) test performed on. Possible ocular alterations related to vitamin A and the status of anemia, serum zinc, some acute-phase proteins, and anthropometric situation were determinate by an analytic design. RESULTS: No child presented xerophthalmia. Serum retinol values lower than 1.05 and 0.7 micromol l(-1), respectively were found in 26.2 and 5.8% of the children. The prevalence of hypovitaminosis detected by RDR test was 20.4%. The following variables and their relationship with VAD were evaluated: sex (P=0.33; 95% confidence interval 0.61-4.34), weight and height (P> or =0.5), hemoglobin (P=0.15), C-reactive protein (P=0.56; 95% confidence interval 0.75-18.26), alpha-1-acid-glycoprotein (P=0.56; 95% confidence interval 0.15-15.42) and serum zinc (P=0.31). None of these variables was related to VAD. CONCLUSIONS: In this population, the prevalence of VAD detected could be considered a public health problem. School-aged children can be considered at risk for VAD mainly of a subclinical level, even without some associated risk factors.

Antioxidant compounds and oxidative stress in female dogs during pregnancy.

Pregnancy is a physiological period during which different metabolic pathways are altered, resulting in greater oxygen consumption and modifications of the consumption of energy substrates, with a consequent greater exposure to oxidative stress. The objective of the present study was to determine and describe the serum profile of some antioxidant biomarkers and of oxidative stress markers during pregnancy in healthy dogs. Twenty nonpregnant (NP) and 20 pregnant (P) female dogs were studied. Serum samples were obtained from the animals during the 1st, 3rd, 5th and 7th weeks of pregnancy or during diestrus for the dosage of antioxidant molecules (vitamin E, vitamin A, zinc and magnesium) and oxidative stress markers (TBARS and carbonyl protein). The results revealed a statistically significant difference (p<0.05) between the P and NP groups during the 3rd and 5th week for vitamins A and E (NP>P), and between the 1st and 3rd week for magnesium (NP>P). The other parameters did not differ between weeks within the same group or between groups. The present study shows that the levels of antioxidant molecules of pregnant dogs differed from that of nonpregnant dogs. These mechanisms may represent a protection against oxidative stress during this period for this species, a fact that definitely deserves further study. Also, the participation of other protective mechanisms and the interference of the fetal-placental unit with oxidative stress are still unknown.

Serum vitamin A levels in patients with ocular lesions attributable to non-complicated malaria in the Brazilian Amazon region.

In order to evaluate the association between serum vitamin A levels and ocular lesions attributable to non-complicated malaria, 200 patients seen consecutively at the Malaria Outpatient Clinic of FUNASA, Manaus, Amazonas, Brazil were included in this study. Ophthalmologic examination consisted of indirect binocular ophthalmoscopy under medicamentous mydriasis, biomicroscopy with a portable slit lamp and measurement of central visual acuity. Vitamin A serum concentration was determined by HPLC, and deficiency was defined as serum values equal to or lower than 0.35 micromol/l. Serum vitamin A values between 0.36 and 0.70 micromol/l were considered as marginal levels. Hypovitaminosis A (

Detection of vitamin A deficiency in Brazilian preschool children using the serum 30-day dose-response test.

BACKGROUND: Vitamin A deficiency (VAD) is endemic in Brazil and health professionals have difficulty in recognizing its subclinical form. In addition, serum retinol concentrations do not always represent vitamin A status in the organism. OBJECTIVE: To identify VAD in preschool children by the serum 30-day dose-response test (+S30DR) and to examine its potential as a tool for the assessment of vitamin A status in the community. DESIGN: A prospective transverse study in which blood samples were obtained from 188 preschool children for the determination of serum retinol concentrations and the children were submitted to ocular inspection and anthropometric measurements. Information about the presence of diarrhea and/or fever during the 15 days preceding the study was also obtained. The children received an oral dose of 200,000 IU vitamin A immediately after the first blood collection. A second blood sample was obtained 30-45 days after supplementation in order to determine the +S30DR. RESULTS: In all, 74.5% (140/188; 95% confidence interval: 68.3-80.7%) of the children presented +S30DR values indicative of low hepatic reserves. The mean serum retinol concentration was significantly lower before supplementation (0.92 and 1.65 micromol/l, respectively; P < 0.0001). No child presented xerophthalmia; 3.7% (7/188) of the children were malnourished. The presence of fever and/or diarrhea during the 15 days preceding the first blood collection did not affect the +S30DR value. CONCLUSIONS: The prevalence of VAD in the study group was elevated. +S30DR proved to be a good indicator of subclinical VAD in children from an underdeveloped country.

Effect of beta-carotene supplementation on rats submitted to chronic ethanol ingestion.

Chronic alcohol consumption is directly related to the induction of liver damage. The continuous use of ethanol induces the isoenzyme cytochrome P450CYP2E1, which promotes the formation of free radicals, resulting in lipid peroxidation. Among the main antioxidants are vitamin E, reduced glutathione (GSH), vitamin C, and beta-carotene. beta-Carotene has antioxidant activity per se, with a probable protective effect against different types of cancer. However, some studies have shown an increased number of cancer cells when beta-carotene is administered in the presence of chronic ethanol ingestion. On this basis, the objective of the present study was to assess the effect of beta-carotene supplementation on rats chronically treated with a hydroalcoholic solution by determining the levels of vitamin E, beta-carotene, GSH, and thiobarbituric acid reactive species (TBARS). Both the plasma and liver concentrations of beta-carotene were higher in the supplemented groups. Plasma vitamin E levels were decreased in the control group and liver vitamin E levels were significantly decreased (p < 0.05) in all groups compared to basal levels. GSH levels were increased over basal values in the group supplemented with beta-carotene for 14 days. TBARS values were increased as much as four-fold in the control group at 14 days, and declined again at 28 days, whereas they were increased in the supplemented group, with the increase remaining until the end of the experiment. The study indicates that beta-carotene had no beneficial effect as an antioxidant on rats submitted to chronic alcohol intake, and could be act as prooxidant when administered with ethanol.

Cytogenetic study of chronic ethanol consumption in rats.

Ethanol was supplied in the drinking water of Wistar rats at a concentration of 20% v/v for up to 30 days. The animals treated with ethanol demonstrated a nonsignificant increase in chromosomal aberration frequency when compared with control animals. The mitotic index values obtained indicated no significant differences between ethanol treatment and control groups. The final weights of control rats were significantly greater than those of the ethanol-treated group. Chronic administration of ethanol showed no clastogenic or cytotoxic effect. After chronic ethanol consumption, the cytochromes P450 activity increases, thus possibly preventing the ethanol that has entered the circulation from reaching excessive levels, leading to metabolic adaptation and/or tolerance.

[Survival and infectious processes in pacients with AIDS: analysis based on initial serum vitamin A levels]. / Sobrevida e processos infecciosos em pacientes com AIDS: análise de acordo com os níveis séricos iniciais de vitamina A.

Patients with Aids (n = 39) were followed up for a maximum period of 36 weeks, after which the types and topographies of infectious complications presented and patient survival were analyzed and correlated with the vitamin A levels presented by the patients at the beginning of clinical follow-up. Twenty-one (53,8%) patients presented serum retinol levels below 1.6 micromol/L, 12 (57%) of whom had values lower than 1.05 micromol/L. There was no correlation between low serum vitamin A levels and the types or topographies of the infectious complications that occurred during the follow-up period. Although mean survival at the end of the 36 months follow-up period was similar for the two groups, patients with retinol deficiency presented a lower probability of survival during the first 24 months of follow-up compared to patients without hypovitaminosis A (8.44 x 1.42 months; p = 0.003).

Effects of malnutrition during early lactation on development and feeding behavior under the self-selection paradigm.

Selection of food can be affected by several factors, and with the method of self-selection, qualitative changes in nutritional balance may be detected. The goal of the present study was to evaluate feeding preferences in weaning rats using three macronutrients (protein, carbohydrate, and fat), through a free-choice method, evaluating the alteration in their feeding patterns as compared with the previous nutritional status during the early lactation period. We analyzed the effects of protein restriction during lactation over the nitrogen balance after the weaning. The dams were assigned to one of two diet conditions (nourished or malnourished). At weaning, two pups from each litter were housed individually in metabolic cages, and they were maintained on self-selection under a free-choice paradigm and were provided with separate sources of macronutrients. The parameter for evaluating the nutritional effectiveness of the diets was nitrogen balance. We observed that protein intake tended to increase and consumption of carbohydrate and fat tended to decrease progressively during the 3 wk of experiment. In selecting their own food, growing rats and malnourished rats consumed a larger amount of protein than the other rats. Nourished rats selecting their diet had a larger nitrogen balance than nourished rats receiving a composed diet; no nitrogen balance difference was found between the self-selecting groups. Rats can choose an adaptive form when recovering from protein malnutrition.