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Biomedical subjects

A Tapparo

Publications and source records attributed to A Tapparo.

17 recordsLinked to original sources
PubMed2001

Aluminum promotes neuronal plasticity events in a mouse neuroblastoma cell line.

The effects of aluminum(III) on microtubular meshwork have been investigated using cultured murine neuroblastoma cells grown in a medium containing aluminum lactate at defined metal concentrations (10-20 microM). A role of aluminum(III) in promoting neuronal plasticity events is suggested. These events including sprouting and neurite outgrowth are associated with an increased tyrosine-tubulin (Tyr-Tub) expression, which can be due to the enhanced needs of recently formed, highly dynamic microtubules typical of neuronal plasticity. After 48 and 72 h aluminum exposure, an upregulation of Tyr-Tub expression is detected and this is concentration-dependent. A high amount of Tyr-Tub is observed also in non-treated cells, although later than in aluminum-exposed cells. Thus, it is possible that aluminum(III) accelerates neuronal plasticity events, for which Tyr-Tub is confirmed to be a useful marker.

Aluminum↗
PubMed2001

Headspace gas chromatographic determination of 2-alkyl-5,5-dimethyl-1,3-dioxane derivatives in wastewaters of a polyester resin plant.

The static headspace gas chromatographic technique can be conveniently employed to check the presence and amount of the odorous side-products, 2-R-1,3-dioxanes (R = H, CH3, C2H5, i-C3H7, n-C3H7), directly from the wastewaters flowing from the reactors during the synthesis of polyester resins. By the optimisation of a simple and direct analytical method, the amounts of these compounds may be continuously monitored and controlled. This method is characterized by good repeatability (3-4%) and does not seem to suffer from matrix effects. The detection limits for the determination of the five dioxanes fall in the range 400-700 micrograms dm-3 (alpha = beta = 0.05).

Journal Article↗
PubMed2000

Direct determination of t,t-muconic acid in human urine by two-dimensional liquid chromatography.

The accurate determination of E,E-2,4-hexadiendioic acid (t,t-muconic acid), an important urinary biomarker of benzene exposure, is directly performed in human urine by a new two-dimensional liquid chromatographic method. After a first partial separation of urine components by a reversed-phase mechanism and the focalisation of the anionic analytes on a small anion-chromatographic column, a conventional ion-chromatographic analysis with UV detection is carried out. The analytical procedure is fully controlled by the HPLC instrumentation software using an eight-port switch valve. If compared with conventional one-dimensional procedures, the new method produces chromatograms containing a limited number of well resolved peaks and consequently allows better analytical performances: no interfering peaks, absence of bias, repeatability better than 5% in the concentration range 0.09-5 mg dm-3 and a detection limit of 4.0 micrograms dm-3 (alpha = beta = 0.05) for the analysis of real samples.

Chromatography, Liquid↗
PubMed1999

The multigene immunophilin family of Dictyostelium discoideum. Characterization of microsomal and mitochondrial cyclophilin isoforms.

The sequences of two cyclophilin (Cyp) isoforms from Dictyostelium discoideum have been determined. cyp2 is expressed as a 197 amino acid protein, which contains a 22 amino acid-long signal sequence, characteristic of endoplasmic reticulum localization signals, and that is cleaved in the mature protein. Mature Cyp2 has a molecular mass of 18 986 Da. The cyp3 gene encodes a 174 amino acid protein with a predicted molecular mass of 19 016 Da. Its sequence reveals no targeting sequence. From the MS analysis of affinity-purified cyclophilins from different subcellular compartments, we localized the previously described Cyp1 (Barisic K. et al., Dev. Genet. 12 (1991) 50-53) in cytosol, Cyp2 in microsomes and Cyp3 in mitochondria, respectively. The expression of cyp1 mRNA is constant during differentiation, whereas the mRNA level of both cyp2 and cyp3 is regulated and decreases steadily during development.

Amino Acid Sequence↗
PubMed1998

Cloning, sequencing and developmental expression of the genes encoding S4 and S10 ribosomal proteins in the cellular slime mould Dictyostelium discoideum.

The sequences of the rps4 and rps10 genes encoding the Dictyostelium discoideum homologues of the basic ribosomal proteins S4 and S10 were determined from cDNA and genomic DNA clones. They are expressed respectively as 266 and 153 amino-acid-long proteins. In both cases, the N-terminal methionine is cleaved in the mature proteins. S4 contains two putative nuclear targeting signals and displays a strong overall identity (around 60%) to eukaryotic S4 homologues. The rps10 gene harbours a 314-bp intron located close to its 5'-coding end. The overall identity between D. discoideum S10 and eukaryotic homologues is around 38% and rises to 53% in the N-terminal domain. Southern blots suggest that both S4 and S10 are encoded by single genes that are regulated during development. The corresponding mRNAs decrease sharply after 8 h of differentiation.

Amino Acid Sequence↗
PubMed1992

Weight Loss and Complications After Vertical Banded Gastroplasty.

We have performed 124 vertical banded gastroplasties (VBG) according to Mason, except that we used a collar 5.5 cm in circumference. We carried out a midline incision In 68 cases and a left subcostal incision in 56, with double application of a 2-row stapler with reinforcement In the first 69 cases and a single application of a 4-row stapler in 55 (15 with reinforcement, 40 without). We have followed 107 (86.2%) patients for a mean of 30 months (range 3-84). The mortality rate was nil. The intraoperative complications were three spleen lacerations (splenectomy), and the early complications were two gastric leaks (re-intervention) and one gastric bleeding. The late complications were one gastric perforation (re-intervention), four outlet stenoses (one re-intervention), one bleeding by collar erosion and nine ventral hernias (occurring only with the midline incision). The percentage excess weight loss was 46.3 +/- 16.4 at 6 months, 53.4 +/- 17.9 at 1 year, 47.8 +/- 19.6 at 3 years, and 45 +/- 23.3 at 5 years. In 12 cases the weight loss was unsatisfactory (less than 30% of the initial excess weight). Often such failures were due to staple-line disruption. We have had no staple-line disruptions since we stopped performing the reinforcement. VBG has a low incidence of complications, but sometimes these may be serious. In our opinion, the technical procedures which offer a stronger vertical partition give better results for weight loss.

Journal Article↗
PubMed1991

A long-term toxicological investigation on the effect of tris(maltolate)aluminum(III) in rabbits.

The toxicity of i.v. injected hydrophilic aluminum complex tris(maltolate)aluminum(III) was studied in New Zealand white rabbits for a period of time ranging from 5 to 63 wk. Animals were injected 3-5 times a week with 1 mL of 7.5 mM Al(malt)3 and one rabbit with a dose 10 times higher after 14 wk of treatment. Autopical examination was performed on all animals. Chemoclinical analysis (glucose, urea, creatinine, cholesterol, bilirubin, alanin aminotransferase, aspartate aminotransferase, alkaline phosphatase, gamma-glutamyl-transferase, LDH, CK, total protein, triglycerides, and Ca2+) gave no variation in treated animals with respect to the control. The toxicological data show a moderate systemic general toxicity at doses far higher than those used in similar previous experiments using Al(acac)3 (acac = 2,4 pentanedionate), a hydrolytically stable and more lipophilic aluminum(III) complex (1). The diversity of behavior is discussed in terms of metal speciation as well as respect to the thermodynamic and kinetic properties of the two complexes in aqueous solution. The toxicological model presented here emphasizes that neutral, water compatible aluminum(III) complexes are to be considered as promising tools for toxicological experiments providing biological models of human pathologies.

Aluminum↗
PubMed1990

Experimental aluminum pathology in rabbits: effects of hydrophilic and lipophilic compounds.

Aluminum lactate [Al(lact)3] (hydrophilic, hydrolytically unstable) and aluminum acetylacetonate [Al(acae)3] (lipophilic, hydrolytically stable) were tested as potential toxicants to rabbits upon IV administration both as aqueous solutions and as liposome suspensions. Both chemicals behaved as cardiotoxic agents when administered as aqueous solutions, but Al(acae)3 was at least two orders of magnitude more active than Al(lact)3. Al(acae)3, but not Al(lact)3, caused myocardial infarcts resembling those in humans (with contraction bands) at doses as low as 0.24 mg/kg body weight, as well as a prominent acanthocytosis. Al(lact)3, when administered as a liposome suspension, was about 300 times more toxic than in aqueous solution, although cardiac damage was not infarctual in character. Both chemical and physical speciation of aluminum(III) thus play an essential role in determining the toxicity of the metal.

Aluminum↗
PubMed1989

[Ano-rectal candidiasis].

The presence of candida and other fungi was investigated in 300 patients referred with anal problems of diverse aetiology. Candida was present in 13% and played a pathogenic role in about 50% of all positive cultures. It is concluded that cultural tests for fungal pathogens should always be performed in cases of anal itching or burning combined with other anal skin problems.

Adolescent↗
PubMed1989

[Cloacogenic carcinoma of the anus. Description of a clinical case].

A clinical case of cloacogenic anal carcinoma is reported. These neoplasms, deriving from embryonal residuals at different levels of the ano-rectal junction, have a better prognosis than squamous carcinomas; the surgical alternative to abdomino-perineal resection is a simple local exeresis for small tumours that do not invade the muscular layer, with a good radical result as reported by the literature.

Aged↗
PubMedDate not supplied

New possible chelating agents of clinical interest for iron(III): 2-hydroxynicotinic acid and 3-hydroxypicolinic acid. A thermodynamic study.

The formation of complexes between iron(III) and two ligands of possible relevance to chelation therapy, 2-hydroxynicotinic acid and 3-hydroxypicolinic acid, in aqueous 0.6 m (Na)Cl at 25 degrees C, has been investigated by means of potentiometric titrations and UV measurements. In both cases several mononuclear complexes and their deprotonation products are formed.

Chelating Agents↗