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Biomedical subjects

M D'Aquino

Publications and source records attributed to M D'Aquino.

At least 19 recordsLinked to original sources
PubMed2005

Antimicrobial activity on glass materials subject to disinfectant xerogel coating.

The antimicrobial compound dodecyl-di(aminoethyl)-glycine was immobilized in a silicon oxide xerogel matrix and used for glass surface coating. Coated glasses were tested for surface antimicrobial activity. The utilization of tetraethoxysilane (TEOS) as a silicon oxide polymer precursor, using the dip-coating process, allowed for the generation of transparent thin films over glass surfaces. Different concentrations of the antimicrobial compound were used to generate the coatings. The presence of dodecyl-di(aminoethyl)-glycine on coated and uncoated slides was analyzed by FT-IR spectra. Coated glass slides were exposed to suspensions of Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus for 24 h. Surface contamination was evaluated by the microbial plate count technique. When antimicrobial-coated glasses were compared with antimicrobial-free coated glasses, the former showed greater than 99% reduction of colony-forming units (cfu) for E. coli and P. aeruginosa, when 1% of antimicrobial was present in the coating solution. The same percentage of reduction for S. aureus was achieved when 1.5% of the antimicrobial was present in the coating solution. In a direct inhibition test on agar plates, no inhibitory zone was observed, indicating that the antimicrobial did not diffuse into the media.

Anti-Infective Agents↗
PubMed2005

Immune response in relation to zinc status, sex and antioxidant defence in Italian elderly population: the ZENITH study.

OBJECTIVE: Evaluation of some immune markers in Italian elderly population in relation to zinc status, gender and antioxidant defence. DESIGN: Observational study. SETTING: Italian population. SUBJECTS: Apparently healthy, free-living subjects, 56 men and 52 women, aged 70-85 y, enrolled in Italy. METHODS: Lymphocytes were unstimulated or stimulated with the mitogen phytohemoagglutinin (PHA). The proliferative capacity was measured as incorporation of [3H]-thymidine and reported as stimulation index (SI). Cytokine secretion by lymphocytes was determined by ELISA. The antioxidant enzyme activities were measured using commercial kits. RESULTS: Dietary zinc intake, as well as zinc in serum, red blood cells and urine were on the normal range of values and did not show any difference between men and women. The proliferative response showed a high variability without significant differences between men and women. The amount of secreted pro- and anti-inflammatory cytokines was similar in men and women. No differences were found in the activity of antioxidant enzymes in lymphocytes, namely superoxide dismutase, glutathione peroxidase and catalase, between men and women. An association between SI and serum zinc level in men was found. SI resulted negatively correlated with interleukin (IL)-1beta (R2 = 0.036 and P = 0.012) and IL-10 (R2 = 0.34 and P = 0.040) only in men. IL-10 of PHA-stimulated lymphocytes was negatively correlated with red blood zinc in men (R2 = 0.41 and P = 0.008), while IL-10 of unstimulated and PHA-stimulated lymphocytes were negatively correlated with serum zinc in women (R2 = 0.38 and P = 0.020; R2 = 0.31 and P = 0.040, respectively). No correlation was observed between immune markers and antioxidant enzyme activities. CONCLUSIONS: Only weak differences on immune response between men and women were observed. However, zinc status appears to have more influence on the ability of lymphocytes to proliferate in men than in women.

Aged↗
PubMed2003

What is the scope of bioluminiscence in pharmaceutical clean rooms monitoring?

By means of bioluminiscence ATP present in a sample can be quantified. Thus, it would be a method able to evaluate microbiological or organic matter (from vegetal or animal origin) contamination. The present work analyzes the possibility to assess--from the microbiological point of view--the air of pharmaceutical clean rooms by means of bioluminiscence, using the luminomiter HY-LITE 2 [Merck]. It is thought that the use of this methodology versus microbiological classical methods, will allow to obtain results in the working day. Classical methods demand a minimum of 72 hs incubation to read results. But the real conclusion is that with the used technology, it is not possible to evaluate microbiologically the air of pharmaceutical clean rooms.

Bacteria↗
PubMed1995

Inhibition of human low-density lipoprotein oxidation by caffeic acid and other hydroxycinnamic acid derivatives.

The antioxidant activity of the major phenols derived from hydroxycinnamic acid (caffeic, ferulic, and p-coumaric acids) on in vitro LDL oxidation was screened, using Cu2+ as catalyst. The presence of the second phenolic hydroxy group enhanced the inhibitory effect of these compounds. In fact, at 5 microM concentration, only caffeic acid completely protected LDL from modification as measured as conjugated dienes formation and apo B-100 fragmentation, also preserving alpha-tocopherol. The effect of caffeic acid in inhibiting LDL oxidative modification induced by three different oxidant systems was tested. Using both Cu2+ and 2,2'-azobis (2-amidinopropane)-hydrochloride (AAPH), the inhibitory effect of caffeic acid was dose-dependent. Yet, the better protection was achieved in the metal-ion dependent system. Also the murine macrophages-mediated LDL oxidation was efficiently inhibited by 5 microM caffeic acid. UV-VIS spectra of caffeic acid incubated with cupric ions show the formation of a caffeic acid:copper complex, responsible for a transient chelating activity. This mechanism, coupled with its free radical scavenging property, accounts for the higher inhibitory activity exhibited by caffeic in Cu(2+)-catalyzed reaction.

Analysis of Variance↗
PubMed1994

Lemon juice as a natural biocide for disinfecting drinking water.

The natural biocidal activity of lemon juice was studied in order to explore its possible use as a disinfectant and inhibitor of Vibrio cholerae in drinking water for areas lacking water treatment plants. From January through July 1993, water samples of varying alkalinity and hardness were prepared artificially, and underground and surface water samples were obtained from a number of different rural and urban areas in Argentina's Buenos Aires Province. After measuring the latter samples' hardness and alkalinity, a range of concentrations of lemon juice and other acidifiers were added to each sample, and the resulting pH as well as the samples' ability to destroy V. cholerae were determined. The results show that lemon juice can actively prevent survival of V. cholerae but that such activity is reduced in markedly alkaline water. For example, treatment of underground drinking water, which is characterized as having the greatest degree of alkalinity in our area, will typically destroy V. cholerae if the alkalinity of the water is the equivalent of that produced by 200 mg CaCO3 per liter, if enough lemon juice is added to bring the lemon juice concentration to 2%, and if the lemon juice is allowed to act for 30 minutes. All this points up the need to determine the alkalinity of water from any local source to be treated in the process of assessing the minimum concentration of lemon juice required.

Argentina↗
PubMed1993

Antimicrobial effect of chlorine on Yersinia enterocolitica.

The effects of chlorine at varying pH, culture media and incubation temperatures on one type and two wild type strains of Yersinia enterocolitica were studied. Exposure to 1 and 5 mg 1(-1) did not diminish viability, even after prolonged exposure. A level of 10 mg 1(-1) was required to achieve a 5-log reduction in 120 s for the type strain and 80 s for the wild strains. There was an increase of more than 30% in the rate of disinfection with a 10 degrees C rise, a remarkable increase in antimicrobial activity at pH 5-log reduction in 20 s, as well as marked neutralization of the effect in the presence of 0.1% peptone. Younger cells were more susceptible than older ones, and those from liquid medium more resistant than those from solid medium. Incubation temperature of a 24-h inoculum failed to show any influence. Lastly, there was a noteworthy demand for free chlorine by bacterial biomass, with agreement of the curve depicting the drop in free chlorine in the presence of inoculum with biphasic kinetics of survival curves.

Cell Survival↗
PubMed1992

Genotoxic action of an aqueous extract of Heliotropium curassavicum var. argentinum.

Heliotropium curassavicum var. argentinum is widely employed in gout, rheumatism, neuralgias, arteriosclerotic disorders, muscular algias, phlebitis, varix and other illnesses. In order to analyze the genotoxic effect produced in vitro by this medicinal plant, chromosomal aberrations (CA), mitotic index (MI) and anaphase delay (AD) were studied in the CHO cell line, with and without the addition of S9 mix. Prepared according to the Argentine pharmacopeia 0.1, 1, 10 and 100 micrograms/ml plant decoction (aqueous extract) were assayed. One hundred cells per culture were studied for CA and AD, while MI was calculated for 2000 nuclei. The results revealed a significant increase in the percentage of abnormal metaphases (p less than 0.001) and in total aberrations (p less than 0.001). Both the MI and the AD affected the cell cycle. All results were enhanced by the addition of an S9 fraction. The toxic effect could be associated with pyrrolizidine alkaloids and their N-oxides, which through a process of in vitro metabolism become activated by microsomal oxidation and change into pyrrolic derivatives.

Analysis of Variance↗
PubMed1992

Effect of dietary oils on lipid peroxidation and on antioxidant parameters of rat plasma and lipoprotein fractions.

In order to investigate the influence of fatty acid pattern and antioxidants other than vitamin E on lipid peroxidation and antioxidant levels of plasma very low density and low density lipoproteins (VLDL + LDL), the effects of three diets (equalized for vitamin E) containing soybean oil, olive oil, or an oleate-rich mixture of triglycerides (triolein) were studied in rats. A significantly lower concentration of thiobarbituric acid-reactive substances (TBA-RS) in plasma and lipoproteins was found after the olive oil diet (soybean oil, 3.7 +/- 0.4 nmol/ml; triolein, 2.1 +/- 0.5 nmol/ml; olive oil, 1.5 +/- 0.3 nmol/ml, in plasma) (soybean oil, 0.99 +/- 0.16 nmol/ml; triolein, 0.96 +/- 0.13 nmol/ml; olive oil, 0.38 +/- 0.12 nmol/ml, in the VLDL + LDL fraction). Furthermore, the results from in vitro copper-induced lipid peroxidation, expressed in terms of conjugated dienes, lipid hydroperoxides, and TBA-RS content, showed that VLDL + LDL particles from olive olive oil-fed rats were remarkably resistant to oxidative modification. The results suggest that the fatty acid unsaturation of dietary oils is not the only determining factor of the antioxidant capacity of lipoproteins in this animal model. The maximal protection observed after the olive oil diet may be explained by the presence of other unidentified antioxidants in addition to vitamin E, derived from oil intake. Therefore, the optimal balance between the content of unsaturated fatty acids and natural antioxidants in dietary oils appears to be of major importance.

Animals↗
PubMed1991

Effect of fish oil and coconut oil on antioxidant defence system and lipid peroxidation in rat liver.

Diets high in fish oil containing polyunsaturated fatty acids of the n-3 family, have been suggested to decrease the risk of cardiovascular disease. However these lipids are highly susceptible to oxidative deterioration. In order to investigate the influence of n-3 fatty acids on oxidative status, the effect of feeding rats with fish oil or coconut oil diets was studied by measuring different parameters related to an oxidative free radical challenge. Synthetic diets containing 15% (w/v) fish oil or coconut oil were used to feed growing rats for 4 weeks. As compared to control diet, the fish oil containing diet produced a significant decrease of cholesterol and triglyceride concentration in serum, however there was a significant increase in lipid peroxidation products. In addition, in fish oil fed animals, there was also a decrease in vitamin E and A concentration. Furthermore, the rate of lipid peroxidation in isolated microsomes was three fold higher in rats fed fish oil as compared to rats with coconut oil diet. No significant differences between the two experimental groups were observed in superoxide dismutase (SOD) and phospholipid hydroperoxide glutathione peroxidase (PHGPX) activities. However, there was a decrease in glutathione peroxidase (GPX) activity. These results suggest that fish oil feeding at an amount compatible with human diet, although decreasing plasma lipids, actually challenge the antioxidant defence system, thus increasing the susceptibility of tissues to free radical oxidative damage.

Animals↗
PubMed1989

Vitamin A and glutathione-mediated free radical damage: competing reactions with polyunsaturated fatty acids and vitamin C.

Vitamin A (retinol reacts extremely rapidly (k = 1.4 x 10(9) M-1 s-1) with thiyl free radicals derived from glutathione to form a free radical with a very strong visible absorption (lambda max. = 380 nm, E max. = 4.0 x 10(4) M-1 cm-1). Arachidonate, linolenate, linoleate and ascorbate also react readily but much more slowly (k = 2.2 x 10(7), 1.9 x 10(7), 1.3 x 10(7) and 3.6 x 10(8) M-1 s-1 respectively). These results support the possibility that vitamin A might play a role in protecting lipid membranes against thiyl free radical mediated damage.

Arachidonic Acid↗
PubMed1989

Serum total and free tryptophan levels in term infants fed cow's milk formula or human milk.

We found no significant differences in mean total and free tryptophan concentrations in sera of healthy, full-term infants fed cow's milk formula and healthy, full-term infants who were breast-fed. Serum tryptophan concentrations were measured 1 h after feeding when the infants were 2 and 6 days of age. In this study cow's milk formula compared favourably with human milk as primary nutrition for full-term infants, despite a two-to-three fold higher level of free tryptophan in human colostrum.

Animals↗
PubMed1989

Antimicrobial activity of clove oil dispersed in a concentrated sugar solution.

Essential oil of clove, dispersed (0.4% v/v) in a concentrated sugar solution, had a marked germicidal effect against various bacteria and Candida albicans. Staphylococcus aureus (five strains), Klebsiella pneumoniae, Pseudomonas aeruginosa, Clostridium perfringens, and Escherichia coli inoculated at a level of 10(7) cfu/ml, and C. albicans (inoculum 4.0 x 10(5) cfu/ml) were killed (greater than 99.999%) after 2-7 min in a laboratory broth supplemented with 63% (v/w) of sugar, and containing 0.4% (v/w) of essential oil of clove. Added organic matter (i.e. human or bovine serum) did not impair its antimicrobial activity. Sugar was not necessary for the antimicrobial activity of clove oil, but the concentrated sugar solution provided a good vehicle for obtaining an oil dispersion that is relatively stable for certain practical applications.

Bacteria↗