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M C Dias

Publications and source records attributed to M C Dias.

11 recordsLinked to original sources
PubMed2006

Lack of chemopreventive effects of ginger on colon carcinogenesis induced by 1,2-dimethylhydrazine in rats.

Ginger (Zingiber officinale Roscoe) has been proposed as a promising candidate for cancer prevention. Its modifying potential on the process of colon carcinogenesis induced by 1,2-dimethylhydrazine (DMH) was investigated in male Wistar rats using the aberrant crypt foci (ACF) assay. Five groups were studied: Groups 1-3 were given four s.c. injections of DMH (40 mg/kg b.w.) twice a week, during two weeks, whereas Groups 4 and 5 received similar injections of EDTA solution (DMH vehicle). After DMH-initiation, the animals were fed a ginger extract mixed in the basal diet at 0.5% (Group 2) and 1.0% (Groups 3 and 4) for 10 weeks. All rats were killed after 12 weeks and the colons were analyzed for ACF formation and crypt multiplicity. The rates of cell proliferation and apoptosis were also evaluated in epithelial colonic crypt cells. Dietary consumption of ginger at both dose levels did not induce any toxicity in the rats, but ginger meal at 1% decreased significantly serum cholesterol levels (p<0.038). Treatment with ginger did not suppress ACF formation or the number of crypts per ACF in the DMH-treated group. Dietary ginger did not significantly change the proliferative or apoptosis indexes of the colonic crypt cells induced by DMH. Thus, the present results did not confirm a chemopreventive activity of ginger on colon carcinogenesis as analyzed by the ACF bioassay and by the growth kinetics of the colonic mucosa.

1,2-Dimethylhydrazine↗
PubMed1996

In vitro reassembly of the malolactic fermentation pathway of Leuconostoc oenos (Oenococcus oeni).

The mechanism of metabolic energy generation by malolactic fermentation was studied with artificial membrane vesicles of Leuconostoc oenos (Oenococcus oeni). (Note that although L. oenos was recently reclassified as O. oeni [L. M. T. Dicks, F. Dellaglio, and M. D. Collins, Int. J. Syst. Bacteriol. 45:395-397, 1995], the old designation was kept in the present work.) Purified malolactic enzyme was entrapped in artificial membrane vesicles prepared from L. oenos cells able to transport L-malate. We show that the in vitro reconstituted system, including an electrogenic L-malate carrier and the decarboxylating malolactic enzyme, generated a proton motive force that was able to drive intravesicular accumulation of leucine.

Biological Transport↗
PubMed1994

Uniport of monoanionic L-malate in membrane vesicles from Leuconostoc oenos.

L-malate transport was studied in membrane vesicles from Leuconostoc oenos MLE(-) (mutant lacking malolactic enzyme) which were fused with liposomes containing beef heart cytochrome c oxidase as a proton-motive-force-generating system. In these hybrid membranes, accumulation of L-malate was observed in response to a pH gradient (delta pH), with the inside alkaline, but was strongly inhibited by a membrane potential (delta psi) of normal polarity (inside negative). Imposition of a delta psi, with the inside positive, by means of valinomycin-mediated potassium influx, resulted in a rapid accumulation of L-malate, indicating that L-malate was taken up in an anionic form. The results are consistent with a uniport mechanism facilitating the uptake of monoanionic L-malate, the dominant species at the low pH of the experiments. Kinetic analysis of delta pH-driven L-malate uptake in the pH range 3.0-5.8, yielded apparent affinity constants that varied less than twofold when calculated on the basis of the concentrations of monoanionic L-malate, whereas the values differed 2-3 orders of magnitude for the other species. At L-malate concentrations above 1 mM, a non-saturable transport component became apparent which may reflect passive influx of L-malic acid. Substrate specificity studies indicated that citrate and L-malate (and possibly D-lactate and L-lactate) compete for a single general carboxylate transport system. The carboxylate transport system catalysed homologous L-malate and heterologous L-malate/citrate exchange with rates similar to the rate of L-malate efflux. Since metabolic energy is conserved during malolactic fermentation in L. oenos, the underlying mechanism most likely involves electrogenic monoanionic L-malate uptake, in combination with H+ consumption in the cytoplasm, followed by diffusion outwards of lactic acid plus carbon dioxide.

Animals↗
PubMedDate not supplied

[Black grain mycetoma caused by Madurella grisea].

The authors reported one case of eumycotic mycetoma due to Madurella grisea (black grains) occurred on the right foot of the patient studied. The structure, microscopic morphology and therapeutic evolution are also studied and reported.

Adult↗
PubMedDate not supplied

[Contamination of enteral diet solutions in nosocomial environment].

The gastrointestinal tract is comparatively resistant to food-born germs, but recent studies suggest that nosocomial infections may be triggered by this route. In a study with industrialized diets, prepared with aseptic technique and stored up to 24 hours, aerobic and anaerobic contaminants were searched. Samples were taken after 0.8 and 24 hours, whereas half of these last two analyses were carried out in material left at room temperature, and the other half in refrigerated diets. Initial examination revealed 50% of positive cultures, but part of this was due to non-pathogenic Bacillus germs. After 8 and 24 hours 90% of the samples grew organisms, again with a large proportion of Bacillus, but also with several Gram-negative bacteria, as well as rare Gram-positives. Diarrhea and fever were not registered in patients submitted to enteral nutrition during the study period, nor could any episodes of bacteremia or septic shock be attributed to contaminated feeding material. This lack of clinical consequences of the reported bacterial isolations is not unexpected, and suggests that low concentrations of microorganisms were probably present in the preparations, below a critical level. Nevertheless, attention will be required in the future for better quality control of enteral nutrition mixtures, specially when resistant strains of Gram-negative species are identified, and also in the management of debilitated or immunologically compromised hosts.

Bacteria, Aerobic↗
PubMedDate not supplied

[Papillary carcinoma of the male breast].

The authors described a breast intraductal papillary carcinoma, of a 73 year old man, with a Paget disease presentation. The pathological features of differential diagnosis were discussed and enunciated the literary review of the etiology and prognosis.

Aged↗
PubMedDate not supplied

[Nutritional support, free radicals, and antioxidants].

Antioxidants and free radical scavengers are molecules endowed with the ability of neutralizing reactive oxygen species that may accumulate in the organism during various pathologic processes. In circumstances of peroxidation of lipids and damage to enzymatic chains, cell membranes and other structures may be followed by functional losses and even cell death. Many antioxidants are normal constituents of the diet in the form of vitamins, trace elements and amino acids, and other useful properties cannot be easily distinguished from their free-radical scavenging abilities. Much controversy surrounds also the indications of these substances, both for prophylactic and therapeutic purposes. The first large-scale population studies have only recently been arranged, and additional investigations are required in many promising areas, including cancer patients undergoing chemo and radiotherapy.

Antioxidants↗
PubMedDate not supplied

[Nutritional assistance to patients during radiotherapy].

With the aim of assessing the possible benefits of nutritional therapy, 140 patients were prospectively studied during radiotherapy of the head and neck (81%) and esophageal cancer (19%). Mean age was 56.0 (17-80), with 114 males and 26 females. Duration of both nutrition and radiotherapy was 78.0 +/- 45 days. Tube feeding was the primary modality in 50.7% of the population, and oral regimens in the remaining 49.3%, but associations between the methods were also used. Enteral diets were supplied under the supervision of a specialized tem for home alimentation (PROSNED). Compliance to the program was 100%, and a lymphocyte count diminished along this period (1933 +/- 1033 vs 1265 +/- 688, p. 0.001). A subjective improvement was reported by 84% of the population, and total calorie intake, that was below 60% of estimated needs in 100% of the cases initially, significantly improved to just 40% inadequate at the end of the observations. Radiotherapy was associated with mucositis in 21% of the patients, taste changes in 79%, xerostomy in 81%, anorexia in 66% and odinophagia in 59%. In the individuals selected for enteral feeding, side-effects were represented by technical problems (20%) and gastrointestinal disorders (13%). All patients completed the nutritional support program and there was no mortality in this series. It is concluded that; 1) Early nutritional support during radiotherapy was able to maintain or improve the nutritional status; 2) Tube feeding, alone or in combination with oral diets, was indicated whenever appropriate and contributed to fulfillment of the energy requirements; 3) Reduction of total lymphocytes could not be prevented by the mentioned therapy; 4) Complications of enteral alimentation were mild and affected a small proportion of the population; 5) Troubles induced by radiotherapy were as frequent as expected, and tended to disturb the intake of food; 6) The compliance to the therapeutic plan was excellent and can be attributed to the efforts of the multidisciplinary team as well as to the help of the specialized home alimentation unit (PROSNED): Diet therapy. Cancer. Nutritional assessment. Radiotherapy. Nutritional support.

Adolescent↗