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Biomedical subjects

A Lodi

Publications and source records attributed to A Lodi.

At least 19 recordsLinked to original sources
PubMed2003

Nitrate and phosphate removal by Spirulina platensis.

The cyanobacterium Spirulina platensis was used to verify the possibility of employing microalgal biomass to reduce the contents of nitrate and phosphate in wastewaters. Batch tests were carried out in 0.5 dm3 Erlenmeyer flasks under conditions of light limitation (40 micromol quanta m(-2) s(-1)) at a starting biomass level of 0.50 g/dm3 and varying temperature in the range 23-40 degrees C. In this way, the best temperature for the growth of this microalga (30 degrees C) was determined and the related thermodynamic parameters were estimated. All removed nitrate was used for biomass growth (biotic removal), whereas phosphate appeared to be removed mainly by chemical precipitation (abiotic removal). The best results in terms of specific and volumetric growth rates (mu=0.044 day(-1), Qx=33.2 mg dm(-3) day(-1)) as well as volumetric rate and final yield of nitrogen removal (Q(N-NO3-)=3.26 mg dm(-3) day(-1), Y(N-NO3-)=0.739) were obtained at 30 degrees C, whereas phosphorus was more effectively removed at a lower temperature. In order to simulate full-scale studies, batch tests of nitrate and phosphate removal were also performed in 5.0 dm3 vessels (mini-ponds) at the optimum temperature (30 degrees C) but increasing the photon fluence rate to 80 micromol quanta m(-2) s(-1) and varying the initial biomass concentration from 0.25 to 0.86 g/dm3. These additional tests demonstrated that an increase in the inoculum level up to 0.75 g/dm3 enhanced both NO3- and PO4(3-) removal, confirming a strict dependence of these processes on biomass activity. In addition, the larger surface area of the ponds and the higher light intensity improved removal yields and kinetics compared to the flasks, particularly concerning phosphorus removal (mu=0.032-0.050 day(-1), Qx=34.7-42.4 mg dm(-3) day(-1), Q(N-NO3-)=3.24-4.06 mg dm(-3) day(-1), Y(N-NO3-)=0.750-0.879, Q(P-PO4(3-))=0.312-0.623 mg dm(-3) day(-1), and Y(P-PO4(3-))=0.224-0.440).

Biomass↗
PubMed2003

The control of nitrilotriacetic acid in edetic acid and its salts by liquid chromatography.

Two liquid chromatographic methods have been developed and validated for the determination of nitrilotriacetic acid (NTA) in edetic acid (EDTA) and its salts. In one method NTA and EDTA are separated on a polymer column without pretreatment, and are detected amperometrically using a glassy-carbon electrode. In the other method NTA and EDTA are complexed with ferric ions and the complexes separated on a porous graphite carbon stationary phase with ultraviolet detection at 215 nm. Both methods were sufficiently selected and sensitive to allow the control of NTA (0.1% m/m) in sample of EDTA and its salts.

Chromatography, Liquid↗
PubMed2002

Bioleaching of zinc and aluminium from industrial waste sludges by means of Thiobacillus ferrooxidans.

Biological solubilisation of heavy metals contained in two different kinds of industrial wastes was performed in batches employing a strain of Thiobacillus ferroxidans. The wastes tested were: a dust coming from the iron-manganese alloy production in an electric furnace (sludge 1) and a sludge coming from a process treatment plant of aluminium anodic oxidation (sludge 2). The experimental results pointed out the ability of the used strain to maintain the environment, that initially has a pH about 8, at strongly acid conditions (pH 2.5-3.5), producing sulphuric acid that is the chemical agent responsible for the metals solubilisation. At wastes initial concentration of 1%, the percentage of solubilised metals was 76 and 78% for the wastes 1 and 2, respectively, but the lag phase was considerably longer for sludge 2 than for sludge 1, indicating a different affinity of microorganisms for the solid phase. Increasing the initial slurry concentration, the percentage of removed metal reached 72-73% for the sludge 1, while in case of sludge 2, the total amount of solubilized metal progressively decreased. Two kinetic models are proposed to describe the trends of metals solubilization curves.

Aluminum↗
PubMed2001

Treatment of effluent containing micropollutants by means of activated carbon.

Different amounts of granular activated carbon (GAC) have been tested for the removal of aliphatic and aromatic micropollutants contained in a liquid stream coming from an industrial plant. Tests have been carried out in a JAR-Test apparatus, using plugged flasks, in order to eliminate the oxygen influence on the adsorption process and to obtain information for studying the process in a pilot plant. The removal of aliphatic compounds resulted better than aromatic ones, probably because these substances are enveloped by water molecules which make adsorption on the GAC surface easier; in contrast, aromatic compounds show a lower affinity for the GAC, owing to their steric conformation. The good results obtained confirm that the proposed system is applicable to the examined effluent, even when the concentration of the pollutant load varies. In the latest part of this work, a plan for the construction of a full-scale plant to treat the examined wastewater has been developed.

Adsorption↗
PubMed2000

Epidemiology of occupational contact dermatitis in a North Italian population.

Occupational contact dermatitis (OCD) is a very important skin disease both for its high frequency and for its social and economic implications. The aim of our work is to evaluate the epidemiology of occupational contact dermatitis in a north-Italian population and the possibility of a correct etiological diagnosis using the patch test standard series of GIRDCA (Italian Group of Resarch on Contact Dermatitis). We patch tested 1,565 out-patients affected by dermatitis with standard series GIRDCA and with other specific professional haptens. The manifestations were suspected of being of occupational origin by a dermatologist on the basis of clinical and anamnestic data. Of all the recorded professions we have considered only the more numerically significant: food industry, building industry, textile industry, employees, cleaners, hospital personnel, hairdressers, housewives, mechanics and metallurgists. Sixty-nine percent of contact dermatitis was found in women, the hairdressers had the greatest number of patients in the younger group (68.7% in the 11-20 years age group) and the textile industry workers in older group (100% in the 41-50 years age group). A positive allergological anamnesis emerged in 32.3% of allergic contact dermatitis. Irritant contact dermatitis (10.6%) was more frequent than allergic contact dermatitis (8.4%). The hands are the most common localization (94. 4%). The allergen with the highest frequency of positive reactions is p-phenylenediamine (25.3%). We discuss the frequency of positives to various groups of allergens in each profession and the principal means of contact. Because of the frequency of this type of occupational skin disease, we stress the importance of prevention. The standard series GIRDCA was found to be adequate for recognizing occupational contact dermatitis in most of our patients (74%).

Adolescent↗
PubMed1999

Relationship between intrathyroid calcifications and thyroglobulin in endemic goiter.

Intrathyroid calcifications represent a common finding within simple or nodular goiters, but, as far as they can be found also inside papillary and medullary thyroid carcinomas, an ultrasonographic detection of intrathyroid calcifications stands as a different diagnosis problem. We have been looking for the presence of parameters associated with thyroid calcifications in patients affected by simple or nodular goiter, either sporadic or endemic. We studied 284 euthyroid subjects, 250 females, ageing from 24 to 90 years, affected by a simple goiter, in the 9.51% of the cases, and by a nodular goiter in the remaining part. 69.37% of the patients came from an endemic goiter area, while the others were affected by sporadic goiter. We tested fT3, fT4, TSH, hTG, Ab-TG, Ab-TPO and performed an ultrasonography in all the subjects, 57.75% of patients shown intrathyroid calcifications in the 57.75% of them. We applied a multistep discriminant analysis taking for the presence/absence of calcifications as dependent variable and we tried to find which variable, by itself or in combination with others, could foretell its presence. We also created a new variable (TG1) to differentiate normal from supraphysiologic concentrations of hTG (< 60 ng/ml). The variable with the highest significance F originated from endemic goiter area (F = 96.36), followed by TG1 (F = 24.46) and age (F = 10.61). On the contrary hTG did not relate to calcifications, due to non-proportionally direct relationship between these two parameters, afterwards we used the multistep logistic regression that gave overlapping significances. This means that supraphysiologic hTG rates are sufficient to predict the possible presence of intrathyroid calcifications. In conclusion, as far as a follicular hyperstimulation can be assumed, especially if long-lasting, the presence of intrathyroid calcifications should rise a clinical suspect toward an old goiter rather than a neoplastic lesion.

Adult↗
PubMed1999

Morphological and functional evaluation of isolated rat hepatocytes in three dimensional culture systems.

Various three-dimensional configurations, such as polyester tissue and woven-nonwoven, hydrophilic polyester fabric, either collagen-coated or uncoated, were investigated as potential scaffold for hepatocyte culture, in view of their use in bioreactors for hybrid liver support systems. Attachment, morphology and ultrastructure of primary adult rat hepatocytes were evaluated, as well as urea production and ammonium detoxification during a 24h incubation period in serum-free tissue culture medium. As control, hepatocytes were also plated onto collagen-coated dextran microcarriers and on plastic petri dishes, either collagen-coated or uncoated. In all the three-dimensional cultures, hepatocytes appeared morphologically intact without any statistically significant difference in metabolic activity. Collagen-coating did not influence cell attachment to polyester substrates, whereas woven-nonwoven hydrophilic polyester fabric may offer some potential advantages as three-dimensional system for hepatocyte culture in hybrid liver support systems.

Animals↗
PubMed1998

In vitro stability of polymerase chain reaction-generated DNA fragments in serum and cell extracts.

The potential use of polymerase chain reaction (PCR)-generated DNA fragments (PCR-DNAs) as pharmaceutical agents has previously been suggested, with the demonstration of the in vitro cellular internalization and biologic activity of PCR-DNA decoy molecules targeted to human estrogen receptor gene. In order to provide information on the stability of these double-stranded DNA molecules, the nuclease resistance of PCR-DNAs of different sizes was studied in different conditions and experiments. Simulating in vitro and in vivo transfection protocol, we demonstrated that PCR-DNAs exhibited good stability toward fetal bovine serum (FBS) and adult human serum nuclease digestion. In addition, when the protective activity of liposome-based formulations toward nuclease digestion was tested, it was shown that the stability of PCR-DNAs could be further increased (up to 7 days) when a liposome-mediated delivery system was employed.

Adult↗
PubMed1998

An immunohistochemical study of progesterone receptor in thyroidal Hürthle cells tumors.

Estrogen (ER) and progesterone (PgR) receptors are commonly represented on normal and neoplastic thyroid tissues, while a few data are available about their expression in Hürthle cells tumors. Seventeen patients who underwent thyroidectomy for a neoplasia that showed oxyphilic elements were studied by an immunohistochemical method and the presence of PgR in the 30% of them, was demonstrated, while no ER expression could be found. We tried, therefore, to establish a correlation between these proteins and age, sex or indexes of the supposed estro-progestinic concentration of our patients. None of these factors resulted significantly related to the receptors expression. Since PgR are expressed in the oxyphilic cells neoplasms, further studies on both ER, and PgR are needed in order to point out their possible biological importance.

Adenocarcinoma, Follicular↗
PubMed1997

[Formulation and stability of suspensions for preclinical study].

In preclinical studies, poorly soluble drugs are usually administered orally to experimental animals as suspensions. The present study was aimed at providing data allowing predictive estimations of the stability of such suspensions. To this purpose aqueous suspensions of three drugs (griseofulvin, ibuprofen and indomethacin) were prepared at different concentrations using four different suspending agents: sodium carboxymethylcellulose (CMC), microcrystalline cellulose/carboxymethylcellulose (MC/CMC), hydroxypropylmethylcellulose (HPMC) and jota carragenaan (CJ). The physical and physico-chemical characteristics of the drugs, the rheological properties of the suspending media and of the corresponding drug suspensions, and the physical and chemical stability of the suspensions was then evaluated. The type of suspending agent, rather than the physical characteristics of the drug, appeared to exert the main influence on the physical stability of suspensions. The most stable formulations were produced by suspending agents with low-temperature gelation characteristics (CJ) or with thixotropic flux (MC/CMC).

Chemical Phenomena↗
PubMed1994

Hepatic conversion of amino-nitrogen to urea in thyroid diseases. II. A study in hyperthyroid patients.

Conflicting data have been reported on the influence of thyroid hormones on hepatic nitrogen metabolism and on liver metabolic activity. We studied the urea-nitrogen synthesis rate (UNSR) and the kinetics of the process of hepatic amino-nitrogen to urea-nitrogen conversion in response to constant alanine infusion (ie, the functional hepatic nitrogen clearance [FHNC]) in five hyperthyroid female patients before and after the achievement of a stable euthyroid status. In the same patients, galactose elimination capacity and antipyrine clearance were also measured as quantitative indices of hepatic function. The basal urea synthesis rate was nearly doubled in hyperthyroid patients (35.6 +/- 8.5 mmol.h-1 v 17.6 +/- 7.7 in euthyroid patients, P < .05) and increased linearly with increasing alpha-amino-nitrogen (alpha-AN) concentrations in both conditions. The urea synthesis rate during alanine infusion was still higher by approximately 30 mmol.h-1 in hyperthyroid subjects. The FHNC, calculated as the slope of the linear relation between the UNSR in each time interval and the corresponding average alpha-AN concentration, was not different (hyperthyroidism, 30.6 +/- 7.2 L.h-1; euthyroidism, 28.5 +/- 4.4; normal values > 25). The hepatic microsomal and cytosolic activities (antipyrine clearance and galactose elimination) were normal in hyperthyroid patients and did not change significantly after therapy. Our data show that the hepatic nitrogen metabolism of hyperthyroid patients is characterized by an upregulation of amino-nitrogen catabolism and loss of the sparing mechanism at low plasma amino acid levels, without any change in different metabolic activities.

Adult↗