PubMed Health⌕ Search

Biomedical subjects

A Antonucci

Publications and source records attributed to A Antonucci.

At least 19 recordsLinked to original sources
PubMed1992

Leukemic evolution in three patients with myelodysplastic syndrome and unusual chromosome changes.

The authors describe three patients with myelodysplastic syndrome without a history of exposure to chemical agents and who showed many chromosome rearrangements not previously reported in this hematologic disorder, and a rapid outcome of the disease. The authors discuss the significance of the chromosome changes, suggesting, in agreement with others, that patients with complex rearrangements have a poor prognosis.

Acute Disease↗
PubMed1992

Age-related events in active T subpopulation. Changes in polyphosphoinositide metabolism during mitogenic activation.

The active E rosette test allows the characterisation of a lymphocyte subset with high affinity receptors for sheep red blood cells. In this study, we compared active T lymphocytes of healthy subjects over 65 and under 30 years of age after mitogenic stimulation. Active E rosettes increased in both age groups after 48 h of phytohemoagglutinin (PHA) stimulation, mainly in young subjects. In addition, analysing the in vitro phosphorylation of inositol lipids, changes occurred in the incorporation of radioactivity in both phosphatidylinositol 4-phosphate (PIP) and phosphatidylinositol 4,5-bis phosphate (PIP2) in the early steps of the mitotic response in the elderly subjects as compared to young ones, hinting that modifications of this signal transduction system are related to mitogenic stimulation in this peculiar T subpopulation.

Adult↗
PubMed1992

Cytogenetic survey of 80 patients with acute nonlymphocytic leukemia.

The authors report a cytogenetic survey of 80 patients with acute nonlymphocytic leukemia. The prognostic value of chromosome aberrations has been evaluated with three methods. The first one showed that patients with NN or AN bone marrow cellularity have a significantly better prognosis than those with AA cellularity; the second method confirmed the relatively good prognosis for patients with t(8;21) and abnormal 16 and a poor one for those with rearrangements of chromosomes 5 and/or 7. The authors also noted, surprisingly, that patients with hyperdiploidy had a significantly poorer prognosis than those with hypodiploidy and especially pseudodiploidy. The third method showed that patients with very complex karyotypes and a worse outcome than those with simple changes. Finally, they discuss the prognostic value of unusual and/or undeciphered chromosome changes detected in 18 patients, with a mean survival of 9.6 months, showing that these changes have a negative prognostic significance.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1991

Sulfur-containing cyclic ketimines and imino acids. A novel family of endogenous products in the search for a role.

Aminoethylcysteine, lanthionine, cystathionine and cystine are mono-deaminated either by L-amino-acid oxidase or by a transaminase exhibiting the properties described for glutamine transaminase. The deaminated products cyclize producing the respective ketimines. Authentic samples of each ketimine were prepared by reacting the appropriate aminothiol compound with bromopyruvate, except cystine ketimine which required the interaction of thiopyruvate with cystine sulfoxide. Reduction of the first three mentioned ketimines with NaBH4 yields the respective derivatives with the saturated rings of thiomorpholine and hexahydrothiazepine. The same reduction is carried out enzymically by a reductase extracted from mammalian tissues. Properties of the members of this family of compounds are described. Gas chromatography followed by mass spectrometry permits the identification of most of these products. HPLC is very useful for the determination of the ketimines by taking advantage of specific absorbance at 380 nm obtained by prior derivatization with phenylisothiocyanate. Adaptation of these and other analytical procedures to biological samples disclosed the presence of most of these compounds in bovine brain and in human urine. By using [35S]lanthionine ketimine as a representative member of the ketimine group, the specific, high-affinity, saturable and reversible binding to bovine brain membranes has been demonstrated. The binding is removed by aminoethylcysteine ketimine and by cystathionine ketimine indicating the occurrence in bovine brain of a common binding site for ketimines. The reduced ketimines are totally ineffective in competing with [35S]lanthionine ketimine. Alltogether these findings are highly indicative for the existence in mammals of a novel class of endogenous sulfur-containing cyclic products provided with a possible neurochemical function to be investigated further.

Amino Acids, Sulfur↗
PubMed1991

Technical improvements for flow karyotyping by standard FACS 440 flow cytometer.

Chromosomal DNA measurements represent the most accurate methodology for the quantitative analysis of human karyotype. A modified FACS 440 signal collection is described here. The FSC signal voltage coming from the optical bench has been split in two equal parts by a T-connector placed at the preamplifier entrance. The side scatter channel that is not employed during chromosome analysis has been used for the half-FSC signal. This modification allowed the contemporary use of FSC signal both for gating and analysis leading to a better discrimination of background, and therefore to a more accurate definition of sorting windows.

Cell Line↗
PubMed1991

Dental pulp lipids from Bos taurus during odontogenesis.

During the fetal development of the dental pulp, the various lipid classes show no substantial differences in their relative ratios but differences occur between deciduous and permanent teeth. By chromatography, the amount of free cholesterol was found decreased in deciduous and permanent teeth as compared to fetal teeth. Esterified cholesterol increased in permanent teeth and triglyceride levels were high only in developing permanent teeth. Phosphatidylcholine, sphingomyelin and phosphatidylserine were present in higher concentration in permanent unerupted teeth, while phosphatidylethanolamine was at first constant but then decreased during development in the permanent unerupted teeth. These data suggest that lipid changes are related to the assembly of plasma membranes and to the establishment of the innervation during ontogeny and postnatal development of dental pulp.

Aging↗
PubMed1991

Dimerization and other changes of aminoethylcysteine ketimine.

High performance liquid chromatography and gas liquid chromatography have been used for the study of the stability of aminoethylcysteine-ketimine (AECK) in different experimental conditions. Concentration and acidic pH lead to the formation of the dimer of AECK which is very sensitive to temperature and is slowly converted to the corresponding decarboxylated dimer even at room temperature. In the presence of air at neutral and alkaline pH AECK is converted to an unknown compound having spectral characteristics similar to AECK and to other compounds not detectable by HPLC. Under nitrogen at neutral pH AECK is more stable and only undergoes the dimerization reaction to some extent.

Amino Acids, Sulfur↗
PubMed1990

[35S]Lanthionine ketimine binding to bovine brain membranes.

2H-1,4-Thiazine-5,6-dihydro-3,5-dicarboxylic acid (trivial name: lanthionine ketimine) is a cyclic sulfur-containing imino acid detected in bovine brain extracts. This compound has been synthesized in a heavily labeled form starting from L-[35S]cysteine and purified by high performance liquid chromatography. We demonstrate the existence of a saturable and reversible binding of [35S]lanthionine ketimine to bovine brain membranes. A single population of binding sites with a concentration of 260 +/- 12 fmol/mg protein and a dissociation constant of 58 +/- 14 nM is present. Specific binding is competitively inhibited by other structurally similar imino acids, namely S-aminoethyl-L-cysteine ketimine and cystathionine ketimine. These results suggest a possible functional role for these ketimines in nervous system.

Amino Acids, Sulfur↗
PubMed1990

Detection of 2H-1,4-thiazine-5,6-dihydro-3-carboxylic acid (aminoethylcysteine ketimine) in the bovine brain.

2H-1,4-Thiazine-5,6-dihydro-3-carboxylic acid (trivial name: aminoethylcysteine ketimine) is a cyclic sulfur-containing imino acid detected in bovine brain extracts by means of three different procedures. Gas liquid chromatography of protein-free extracts of five bovine brains revealed the presence of this compound at concentrations ranging from 2 to 3 nmol/g wet weight of tissue. The enzymatic method based on the inhibition of D-amino acid oxidase activity by aminoethylcysteine ketimine together with an high-performance liquid chromatography procedure confirm the identification and quantitations obtained with gas liquid chromatography. The discovery of this compound structurally similar to pipecolic acid opens the question of its physiological role in the central nervous system.

Amino Acids, Sulfur↗
PubMed1990

Detection of cystathionine ketimine in bovine cerebellum.

A new sulfur-containing cyclic imino acid, cystathionine ketimine, has been detected in bovine cerebellum by gas chromatography, gas chromatography-mass spectrometry, and high pressure liquid chromatography procedures. Gas chromatography and gas-mass analyses are based on derivatization of endogenous cystathionine ketimine with diazomethane after a simple enrichment procedure. The high pressure liquid chromatography procedure takes advantage of the selective absorbance at 380 nm of the phenyl isothiocyanate-ketimine interaction product. The concentration of this new sulfur imino acid found in a pool of four bovine cerebella is approximately 0.5 nmol/g.

Animals↗
PubMed1989

Lipid phosphorylation in isolated rat liver nuclei. Synthesis of polyphosphoinositides at subnuclear level.

Isolated rat liver nuclei and subnuclear fractions synthesize polyphosphoinositides in vitro in a mode dependent on the presence of nuclear membrane, detergent and exogenous substrates. The nuclear membrane is not essential as a source of lipid kinases, since the addition of exogenous phosphatidylinositol or phosphatidylinositol monophosphate to reaction mixtures lacking membranes restores the synthesis of phosphatidylinositol mono- and bisphosphate, respectively. Inositide phosphorylation is best accomplished by high-salt extracted nuclei and pre-detergent lamina. These data suggest that the nucleus, and especially the nuclear periphery, is a cell compartment in which polyphosphoinositide synthesis occurs; this might be related to the progression of phosphatidylinositol metabolism-dependent signals to the genetic apparatus.

Adenosine Triphosphate↗
PubMed1989

Improved bromodeoxyuridine/DNA analysis by anti-BudR monoclonal antibody versus right angle light scatter.

Dynamic cell cycle analysis is based on the incorporation of labelled precursors into DNA. Although antibodies to BrdU are very useful for analysing in flow cells which synthesize DNA, this approach has two main limitations. First, the detection of low incorporating cells is often difficult; second, four parameter flow cytometry is not able to correlate cell cycle to any other cellular marker. We have developed a methodology that, employing an IgGH + L as a second antibody and side scatter instead of propidium iodide fluorescence, allows a better discrimination of BudR+ cells. This approach allows the collection of an extra-fluorescent signal, and the analysis of specific cellular markers within the cell cycle.

Antibodies, Monoclonal↗
PubMed1989

Phospholipase C digestion induces the removal of nuclear RNA: a cytochemical quantitative study.

It has been reported that the incubation of isolated rat liver nuclear matrices with phospholipase C causes the digestion of the matrix-bound phospholipids and the release of most matrix-linked RNAs (Cocco et al., 1980). In this paper, the presence of phospholipids in nuclear substructures and the effects of their removal by phospholipase C digestion have been investigated by means of enzyme-colloidal gold cytochemistry. The nuclear phospholipids appear to be localized in the interchromatin areas and in the nucleolus and are virtually absent in the heterochromatin, when labelled with phospholipase C-colloidal gold. The double labelling test with ribonuclease A and phospholipase C conjugated with gold particles of different diameters shows that the nuclear phospholipids are co-localized with RNA-containing structures. The enzymatic digestion of phospholipids on thin sections of either isolated nuclei or pancreas embedded in LR White resin results in the decrease of the RNase-A colloidal gold labelling of nuclear RNA-containing structures, but not of the rough endoplasmic reticulum. The data confirm the presence of phospholipids in the nucleus in the absence of possible translocation due to isolation procedures and strengthen the hypothesis that they are involved in interactions between nucleic acids and proteins of the nuclear matrix.

Animals↗
PubMed1979

[Chromatographic determination of arylsulfatases A and B in human gastric mucosa].

In continuation of a previous work, we have confirmed the occurrence of arylsulfatase A in 4 samples of human gastric mucosa analysed by the chromatographic procedure described by Stevens et all. By using the chromatographic method we have also evidentiated the occurrence of arylsulfatase B, which was not detected by using the method of Baum et all. The B form was lower than the A form in 3 samples while it was higher in another sample. In the latter sample of gastric mucosa it was also detected the unusual form Bm of arylsulfatase. It was concluded that both forms A and B of arylsulfatase are present in human gastric mucosa, in variable amounts and that the simple procedure developed by Baum et all., although suitable for the analysis of these enzymes in the urine, is not useful for the determination of arylsulfate B in the gastric mucosa.

Aged↗