Search PubMed⌕ Search

Biomedical subjects

A Minelli

Publications and source records attributed to A Minelli.

At least 91 records · Page 5Linked to original sources
PubMed1990

Adenosine metabolizing enzymes in seminal plasma of bull and man: a comparative study.

1. Adenosine metabolizing enzymes in seminal plasma of man and bull have been investigated. 2. A different level of 5'-nucleotidase activity has been found in two seminal plasmas: in bull 5'-nucleotidase represents 80% of the total AMP dephosphorylating enzymes while in man 5'-nucleotidase represents only 1.3% of the total AMP dephosphorylating activities. 3. Apart from the different levels of 5'-nucleotidase activity, different kinetic parameters have been reported for 5'-nucleotidase, acid prostatic phosphatases, ADA and PNP. 4. Adenosine kinase, xanthine oxidase and AdoHcy-hydrolase have not been detected in the seminal plasma of man and bull.

5'-Nucleotidase↗
PubMed1989

Cytogenetic and molecular analysis of an unbalanced translocation (X;7) (q28;p15) in a dysmorphic girl.

A severely retarded and dysmorphic girl, carrying an unbalanced X/7 translocation with breakpoints at Xq28 and 7p14, was analyzed by cytogenetic, biochemical and molecular techniques. The X/7 translocated chromosome was found to replicate consistently late in the 105 metaphases analyzed. In 83 of these cells, late replication was limited to the X portion of the abnormal chromosome, whereas in 22 cells incomplete spreading into the autosomal fragment was observed. Southern blot and in situ hybridization experiments with probe G80 (locus D7S373) (previously localized to 7p13-15) and G98 (localized to 7p14-15) assigns the former to 7p15 and the latter to 7p14, thus suggesting the order 7ter-G80-G98-cen. The activity of the enzyme phosphoserine phosphatase localized to 7pter-p14 was increased. Southern blotting experiments with 19 probes spanning the entire X chromosome demonstrated that the translocated chromosome had lost a portion of Xq28 (locus DXS51) but still retained part of Xq27 (F9 locus). The results confirm that the proband is trisomic for the region 7p15-pter and monosomic for the region Xq28-qter. Comparing her phenotype with those of other cases of partial trisomy or monosomy 7p, we confirm that band 7q21 is probably involved in skull development.

Abnormalities, Multiple↗
PubMed1988

First trimester prenatal diagnosis of Sanfilippo disease (MPSIII) type B.

Two pregnancies of a family at risk for Sanfilippo disease type B were monitored in the first trimester. In one case an affected fetus was diagnosed on chorionic villi by the assay of N-acetyl-alpha-D-glucosaminidase and confirmed on cultured fibroblasts from the aborted fetus. Pathological findings are also reported and compared with changes observed later in life. The disease was excluded in the second pregnancy.

Acetylglucosaminidase↗
PubMed1987

De novo complex autosomal translocation involving chromosomes 8, 13 and 15 in a girl with a sporadic retinoblastoma.

We report a case of a 5-month-old female with sporadic monolateral retinoblastoma (RB) with a constitutional de novo complex autosomal translocation involving chromosomes 8, 13 and 15 resulting in a deletion of chromosome 13q14 confirmed by esterase D assay. The translocation of the terminal portion of chromosome 8 has been observed by in situ hybridization with c-myc and thyroglobulin probes.

Chromosome Banding↗
PubMed1986

Concanavalin A induced inhibition of 5'-nucleotidase from guinea pig skeletal muscle and bull seminal plasma: a comparative study.

Both purified and membrane-bound 5'-nucleotidases (EC 3.1,3.5) from guinea pig skeletal muscle and bull seminal plasma are inhibited by Concanavalin A (Con A). 5'-Nucleotidase purified from skeletal muscle is inhibited by Con A by an apparent uncompetitive process (K'i = 160 nM), while the lectin inhibits the particulate enzyme by an apparent non-competitive process (Ki = K'i = 50 nM). 5'-Nucleotidase purified from bull seminal plasma is inhibited by Con A by an apparent non-competitive process (K'i = Ki = 270 nM), while the membrane-bound enzyme is subjected to a mixed type inhibition by the lectin (K'i greater than Ki; 30 and 14 nM, respectively). The enzyme purified from skeletal muscle exhibits a significant cooperativity in the interaction with Con A. The inhibition of bull seminal plasma particulate 5'-nucleotidase brought about by Con A is not completely reversed by addition of alpha-methyl-D-mannoside.

5'-Nucleotidase↗
PubMed1985

Effects of dithiothreitol, dithioerythritol and chelating agents on 5'-nucleotidase from bull seminal plasma.

5'-Nucleotidase from bull seminal plasma is inhibited by dithiothreitol and dithioerythritol. These reactives proved to dissociate the dimeric glycoprotein 5'-nucleotidase of Mr 160 000 into two subunits of apparent Mr 80 000, indicating that the subunits are held together by interchain disulfide bridges. HPLC determinations of cysteic acid and carboxymethylcysteine protein derivatives resulted in 50 +/- 3 half-cystine plus cysteine residues, while 1.9 +/- 0.4 free cysteine residues were estimated by HPLC analysis. The enzyme is inhibited by EDTA and EGTA, and the inhibition appears to be of the non-competitive type for both the chelating agents. Experiments for the enzyme activity recovery by MgCl2 and CaCl2 additions, after the EDTA and EGTA treatments in the presence of 8 M urea, are reported.

5'-Nucleotidase↗
PubMed1984

Inhibition of pig kidney dopa decarboxylase by coenzyme-5-hydroxytryptophan adducts.

The effect of N-(5'-phosphopyridoxyl)-L-5-hydroxytryptophan, N-(5'-phosphopyridoxyl)-D-5-hydroxytryptophan and N-(5'-phosphopyridoxyl)-5-hydroxytryptamine on the reactivation of apoDopa decarboxylase to holoenzyme has been investigated. The different degree of inhibition exerted by these adducts has been interpreted on the basis of a different orientation of the 2 isomers of 5-HTP at the active of Dopa decarboxylase.

Animals↗
PubMed1984

Incidence of childhood cancer in the province of Perugia (Italy).

This paper reports the incidence of childhood cancer in the Province of Perugia (Italy) in 1975-1979 and compares it with that reported in other areas in Italy and other western countries. Over the period studied the new cases of cancers in children under 15 years of age, recorded in the Province of Perugia, were 51 in males and 36 in females. The mean annual incidence rates per 100,000 were 17.93 in males and 13.51 in females so that the male to female ratio of rates was 1.33. The most common neoplasms were leukemia (4.92 per 100,000 in males and 5.25 in females), brain tumours (3.87 in males and 1.50 in females), nephroblastomas (1.40 in males and 1.50 in females), lymphomas (2.81 in males and 0.37 in females). This distribution, in general, is the same as that observed in many other white populations. However some differences in the incidence value rates between the Province of Perugia and other areas of western countries are pointed out both for the cancers as a whole and for certain histologic types.

Adolescent↗
PubMed1982

Inhibitors binding to L-aromatic amino acid decarboxylase.

The effect of a number of inhibitors of L-aromatic amino acid decarboxylase activity on the absorption spectrum of the enzyme-bound coenzyme has been studied. It has been observed that the compounds tested, even if devoid of the amino function and therefore unable to form the Schiff base with the coenzyme, modify significantly the enzyme spectrum, indicating their binding to the coenzyme active site. Spectral modifications suggest that at least two kinds of binding of inhibitors to L-aromatic amino acid decarboxylase may occur, depending on their structural features. Moreover, from the spectra obtained at different concentrations of the inhibitors their affinity constants have been determined: data indicate that the cathecol ring gives the largest contribution to the binding, while the presence of the carboxyl group, the aminic group and the aliphatic chain are responsible for a decrease in the binding, which could be relevant for the efficiency of the catalysis.

Aromatic Amino Acid Decarboxylase Inhibitors↗
PubMed1979

Reactions of DOPA (3,4-dihydroxyphenylalanine) decarboxylase with DOPA.

The study of DOPA (3,4-dihydroxyphenylalanine) decarboxylase by steady-state methods is difficult because multiple reactions occur. The reaction with DOPA was studied at enzyme concentrations between 20 and 50 micrometer by direct observation of the bound coenzyme by using stopped-flow and conventional spectrophotometry. Four processes were observed on different time scales and three of these were attributed to stages in the decarboxylation. The fourth was attributed to an accompanying transamination that renders the enzyme inactive. It was clear that much, if not all, of the 330 nm-absorbing coenzyme present in the free enzyme plays an active part in the decarboxylation, since it is converted into 420 nm-absorbing material in the first observable step. An intermediate absorbing maximally at 390 nm is formed in a slower step. Rate and equilibrium constants have been determined and the ratio of decarboxylation to transamination was estimated to be 1200:1.

Amination↗