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Biomedical subjects

M Putzolu

Publications and source records attributed to M Putzolu.

27 records · Page 2Linked to original sources
PubMed1997

Dihydro(alkylthio)(naphthylmethyl)oxopyrimidines: novel non-nucleoside reverse transcriptase inhibitors of the S-DABO series.

Novel compounds related to 2-(cyclohexylthio)-3,4-dihydro-5-methyl-6-(3-methylbenzyl)-4-ox opyrimidine (3c, MC 639) have been synthesized and tested as inhibitors of human immunodeficiency virus type-1 (HIV-1). Reaction of thiourea with ethyl arylmethylacetoacetates furnished 5-alkyl-6-(arylmethyl)-3,4-dihydro-2-mercapto-4-oxopyrimidines which were then alkylated at the sulfur atom to afford the required 2-alkylthio or 2-cycloalkylthio derivatives (S-DABOs). Chemical modifications at N-3, C-4, and C-6 of the pyrimidine ring were attempted with the aim of improving antiretroviral activity. In particular, replacement of the benzyl group with the 1-naphthylmethyl moiety enhanced the activity of S-DABOs, whereas N-3 alkylation and C=O transformation into C=S at position 4 of the pyrimidine ring led to compounds devoid of anti-HIV-1 activity. Lower activity was generally observed when 1-naphthylmethyl was replaced by the isomeric 2-naphthylmethyl moiety. The most active compounds showed activity in the low micromolar range with EC50 values comparable to that of nevirapine.

Cell Line↗
PubMed1997

Role of cholesterol synthesis and esterification in the growth of CEM and MOLT4 lymphoblastic cells.

CEM and MOLT4 are human T-cell lines isolated from patients with acute cell leukaemia. In culture they show important differences in cholesterol metabolism, CEM being less efficient at synthesizing cholesterol and having a lower activity of 3-hydroxy-3-methylglutaryl-CoA (HMGCoA) reductase. To investigate further the relationship between regulation of intracellular cholesterol metabolism at various steps and rate of cell growth, cholesterol synthesis, esterification and efflux were evaluated in CEM and MOLT4 cells at different times during exponential and stationary growth in vitro. It was shown that, although CEM cells have a lower rate of cholesterol synthesis, they grow at a faster rate than MOLT4 cells. However, CEM cells exhibit an increased capacity to esterify cholesterol associated with a decreased efflux of newly synthesized cholesterol into the medium. These results provide evidence for an association between the capability to synthesize and retain cell cholesterol esters and the growth rate potential.

Acetates↗
PubMed1997

A homozygous nonsense mutation of the human growth hormone receptor gene in a Sardinian boy with Laron-type dwarfism.

Laron-type dwarfism (LTD) is an autosomal recessive disorder due to mutations in the GH receptor (GHR) gene. We report the case of a Sardinian boy affected by LTD in which we found by direct genomic sequencing a nonsense mutation in the fourth exon of the GHR gene (R43X) that determines a premature termination in the protein translation process. As the result of the absence of the extracellular portion of the GHR this patient had undetectable GH binding protein. This molecular defect is identical to that observed in other patients with LTD of mediterranean origin.

Base Sequence↗
PubMed1997

Sulfone derivatives with anti-HIV activity.

Following the discovery of anti-HIV properties of suramin great efforts were devoted to design novel NNRT agents with the aims to find novel drugs for the clinical therapeutic management of AIDS. Sulfone and sulfonamide derivatives were studied by NCI at Bethesda as potential anti-HIV-1 agents and nitrophenyl phenyl sulfone (NPPS) was selected as lead compound for further investigations. At the same time Merck Laboratories discovered L-737,126, a potent indolyl aryl sulfone with inhibitory activity against reverse transcriptase. These studies stimulated novel search in the sulfone series and both diarylsulfones and cyclic sulfone derivatives were investigated. Our decennial interest in chemotherapeutic agents containing a pyrrole ring pulsed us to synthesize and test as anti-HIV-1 agents a number of pyrryl aryl sulfones (PASs), pyrrolobenzothiadiazepine (PBTDs) and pyrrolobenzothiazepine related sulfones. The new sulfone derivatives inhibit selectively HIV-1 and were inactive against HIV-2. Most of them were as active as, if not more active than, nevirapine.

Anti-HIV Agents↗
PubMed1997

Glycosidopyrroles. Part 2. Acyclic derivatives: 1-(1,3-dihydroxy-2-propoxy)methylpyrroles as potential antiviral agents.

The series of 1-(1,3-dihydroxy-2-propoxy)methylpyrroles 2a-o were prepared in good overall yields according to Scheme I. When evaluated for antiviral activity against HIV-1, only compounds of the triphenyl series (R3 = NH2, N3, Br) were found to inhibit the HIV-1 replication at concentrations that were very not cytotoxic for MT-4 cells, with selectivity index 1.5-9.3. None of these compounds showed antibacterial or antifungal activity.

Animals↗
PubMed1996

5H-pyrrolo[1,2-b] [1,2,5]benzothiadiazepines (PBTDs): a novel class of non-nucleoside reverse transcriptase inhibitors.

With the aim of developing novel inhibitors of human immunodeficiency virus, various derivatives (10-17) related to 5H-pyrrolo[1,2-b] [1,2,5]benzothiadiazepine (PBTD) were prepared and tested in vitro. The title tricyclic derivatives were obtained by intramolecular cyclization of the open-chain intermediate arylpyrrylsulfones, followed by N-alkylation at position 10. Among test derivatives some 10-alkyl-5H-pyrrolo[1,2-b] [1,2,5]benzothiadiazepin-11(10H)-one-5,5-dioxides were found to exert potent and specific activity against HIV-1. In particular, 7-chloro derivatives 11i and j showed a potency comparable to that of nevirapine. However, when the chloro atom was shifted to the 8 position, the related products were scarcely active or totally inactive. Replacement of the pyrrole with pyrrolidine led to inactive products and the reduction of SO2 to S strongly diminished the antiviral potency. PBTD derivatives active in cell cultures were also inhibitory to the recombinant HIV-1 RT in enzyme assays, thus allowing the conclusion that PBTDs are a new class of non-nucleoside reverse transcriptase inhibitors (NNRTIs).

Anti-HIV Agents↗
PubMedDate not supplied

Assessment of risk for chromosomal abnormalities at 10-14 weeks of gestation by nuchal translucency and maternal age in 5,210 fetuses at a single centre.

OBJECTIVE: To evaluate the screening of chromosomal abnormalities by nuchal translucency (NT) measurement. METHODS: Assessment of risk for chromosomal abnormalities by NT and maternal age in 5,210 single fetuses with karyotype and outcome already known. RESULTS: Risk was > or =1 in 300 in 640 (12.2%) of all fetuses, in 575 (11.1%) of the normal fetuses, in 38 (80.8%) of the fetuses affected by trisomy 21, and in 65 (89%) of the fetuses affected by chromosomal abnormalities. Risk was > or =1 in 200 in 477 (9.1%) of all fetuses, in 418 (8.1%) of the normal fetuses, in 35 (74.4%) of the fetuses affected by trisomy 21, and in 59 (80.8%) of the fetuses affected by chromosomal abnormalities. Risk was > or =1 in 100 in 270 (5.1%) of all fetuses, in 216 (4.2%) of the normal fetuses, in 33 (70.2%) of the fetuses affected by trisomy 21, and in 54 (73.9%) of the fetuses affected by chromosomal abnormalities. CONCLUSIONS: Risk generated by NT and maternal age is effective in screening for chromosomal abnormalities.

Adult↗
PubMedDate not supplied

MDR1 gene expression in normal and atherosclerotic human arteries(1).

Recent studies have shown that a membrane p-glycoprotein, encoded by MDR1 gene, is involved in the transport of free cholesterol from the plasma membrane to endoplasmic reticulum, the site of cholesterol esterification by acyl-CoA:cholesterol acyltransferase (ACAT). Moreover, results deriving from our previous studies have shown that the rate of cell proliferation was positively correlated with cholesteryl ester levels as well as with ACAT and MDR1 gene expression. In this study, lipid content and the expression of the genes involved in cholesterol metabolism such as hydroxy-methylglutaryl coenzyme A reductase (HMGCoA-R), low-density lipoprotein receptor (LDL-R), ACAT and MDR1 have been investigated in control and atherosclerotic arteries. The results have shown that the levels of cholesteryl ester increase with the age of cadaveric donors in arteries prone to atherosclerosis (abdominal aorta, superficial femoral artery) and become predominant in advanced atherosclerotic lesions. The mRNA levels of ACAT and MDR1 showed the same age correlation, reaching the highest values in atherosclerotic specimens. These results suggest that MDR1 may be involved in the accumulation of intracellular cholesterol ester levels found in atherosclerotic lesions. Moreover, the levels of HMGCoA-R, LDL-R and ACAT gene expressions progressively increased with the age of cadaveric donors; conversely, in atherosclerotic specimens, the mRNA levels of HMGCoA-R and LDL-R drastically decreased while ACAT gene expression reached its maximum. These findings suggest a reactivation of normal homeostatic regulation of cholesterol in advanced and complicated lesions.

Adult↗