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Biomedical subjects

G Perini

Publications and source records attributed to G Perini.

At least 37 records · Page 2Linked to original sources
PubMed1995

Recognition of bZIP proteins by the human T-cell leukaemia virus transactivator Tax.

Human T-cell leukaemia virus type I (HTLV-I) Tax protein increases the DNA binding of many cellular transcription factors that contain a basic region-leucine zipper (bZIP) DNA-binding domain. bZIP domains comprise a leucine-rich dimerization motif and a basic region that mediates DNA contact. How Tax recognizes diverse bZIPs is not understood. Here we show that no specific sequence of the leucine zipper is required for a Tax response. In contrast, the basic region is essential for the Tax-mediated DNA-binding increase, which can be eliminated by single substitutions of several conserved amino acids. Surprisingly, Tax alters the relative affinity of a bZIP for different DNA binding sites. Thus, through recognition of the conserved basic region. Tax increases DNA binding and modifies DNA site selection. Tax provides a model for how a single auxiliary factor can regulate multiple sequence-specific DNA-binding proteins.

Amino Acid Sequence↗
PubMed1994

Fine mapping of a replication origin of human DNA.

A highly sensitive procedure was developed for the identification of the origin of bidirectional DNA synthesis in single-copy replicons of mammalian cells. The method, which does not require cell synchronization or permeabilization, entails the absolute quantification, by a competitive PCR procedure in newly synthesized DNA samples, of the abundance of neighboring DNA fragments distributed along a given genomic region. This procedure was utilized for mapping the start site of DNA replication in a 13.7-kb region of human chromosome 19 coding for lamin B2, which is replicated immediately after the onset of S phase in HL-60 cells. Within this region, DNA replication initiates in a 474-bp area corresponding to the 3' noncoding end of the lamin B2 gene and the nontranscribed spacer between this gene and the 5' end of another highly transcribed one. This localization was obtained both in aphidicolin-synchronized and in exponentially growing HL-60 cells.

Animals↗
PubMed1994

Imipramine in alopecia areata. A double-blind, placebo-controlled study.

Alopecia areata (AA) is a dermatologic disease whose onset is significantly associated to life events. Its course may often be characterized by high levels of anxiety and depression. These observations suggested a rationale for using an antidepressant in AA. Thirteen patients were enrolled in a double-blind, placebo-controlled study of efficacy of imipramine in alopecia. After six months clinically significant hair regrowth occurred in 5 of the 7 patients on imipramine, whereas no response was observed in the placebo group. An improvement in psychic symptomatology was present in both groups. Our preliminary results indicate the potential efficacy of imipramine in patients with AA, not acting directly through a reduction of anxiety or depression.

Adult↗
PubMed1993

Searching for replication origins in mammalian DNA.

The attempts at identifying precise replication origins (ori) in mammalian DNA have been pursued mainly through physico-chemical and biochemical approaches, in view of the essential failure of the search for autonomously replicating sequences in cultured cells. These approaches involve the mapping of short stretches of nascent DNA, the identification of the regions where either leading or lagging strands switch polarity, or the localization of replication intermediates by two-dimensional gel electrophoresis. Due to the complexity of animal cell genomes, most of these studies have been performed on amplified domains and with the use of synchronization procedures. The results obtained have been controversial. In order to avoid the use of experimental procedures potentially affecting the physiological mechanism of DNA replication, we have developed a method for the localization of ori in single-copy loci in exponentially growing cells. This method entails the absolute quantification of the abundance of selected DNA fragments along a genomic region within samples of newly synthesized DNA by competitive polymerase chain reaction (PCR); the latter is immune to all the uncontrollable variables which severely affect the reproducibility of conventional PCR. The application of this method to SV40 ori-driven plasmid replication precisely identifies the known ori localization. Using the same approach, we have mapped an ori for bi-directional DNA replication in a 13.7-kb locus of human chromosome 19 encoding lamin B2.

Animals↗
PubMed1992

A human DNA replication origin: localization and transcriptional characterization.

A single-copy 13.7 kb human DNA region (L30E) located on Ch. 19 p13.3 contains an origin of DNA replication in myeloid HL-60 cells. The origin was localized, by means of quantitative PCR within approximately 3000 bp, in a highly transcribed region containing at least two closely spaced genes with the same polarity of transcription, one encoding lamin B2 and the other an unidentified protein. The origin region overlaps an undermethylated "CpG island" at the 5'-end of the second transcription unit. A binding site (CACGTG) for basic helix-loop-helix (bHLH) DNA binding proteins such as USF/MLTF or MYC-MAX was located by DNase I footprinting analysis in the promoter of the second gene. DMSO differentiation of HL-60 cells, that completely shuts off replication, also drastically reduces the transcription of L30E region. On the other hand such treatment does not modify the methylation pattern of the CpG island and does not abolish the DNase I protection of the bHLH binding site.

Base Sequence↗
PubMed1992

Expression of doxorubicin-daunorubicin resistance genes in different anthracycline-producing mutants of Streptomyces peucetius.

Two DNA fragments, ric1 and ric2, were isolated from the Streptomyces peucetius 7600 mutant, which produces daunorubicin and doxorubicin, on the basis of their abilities to confer doxorubicin and daunorubicin resistance to Streptomyces lividans. These two fragments are unrelated by restriction mapping and do not show any homology by Southern analysis, yet both of them increase the level of resistance 10-fold in transformed S. lividans. Functional analysis revealed that ric1 also contains two genes of daunorubicin biosynthesis: one coding for the aklavinone C-11 hydroxylase and the other corresponding to the putative dnrR2 regulatory gene of wild-type S. peucetius ATCC 29050 (K. J. Stutzman-Engwall, S. L. Otten, and C. R. Hutchinson, J. Bacteriol. 174:144-154, 1992). Northern (RNA) blot experiments, performed with a ric1 fragment containing daunorubicin-doxorubicin resistance gene(s), revealed a transcript of about 2,100 nucleotides that is present only during the phase of anthracycline metabolite production. The amount of this transcript is higher in strain 7600 than in strain 7900, a mutant which produces 5-fold more daunorubicin and 10-fold less doxorubicin than 7600. Furthermore, two 7900-derived blocked mutants, 8600 and 9700, do not express the 2,100-nucleotide transcript in spite of the absence of gross rearrangements in the ric1 region such as occur with the 7900 parental strain.

Cloning, Molecular↗
PubMed1992

The gene for a novel human lamin maps at a highly transcribed locus of chromosome 19 which replicates at the onset of S-phase.

A previously described human DNA fragment which is replicated early in S-phase of HL-60 cell DNA (C. Tribioli, G. Biamonti, M. Giacca, M. Colonna, S. Riva, and A. Falaschi, Nucleic Acids Res. 15:10211-10232, 1987) was used to screen a genomic library in lambda Ch28. A clone which contained a 13.7-kb insert (L30E) found to code for several transcripts was isolated. The transcription of L30E DNA exhibited a complex pattern and a tissue-specific and proliferation-dependent type of regulation. The data were consistent with two tandemly arranged transcription units, the 3' end of one separated from the 5' end of the other by a sequence of about 600 bp containing an active promoter. The isolation and sequencing of L30E-specific cDNAs permitted identification of two genes, one of which encoded a B-type human lamin (analogous to mouse lamin B2). L30E DNA was mapped by in situ hybridization at the G-negative subtelomeric band p13.3 of chromosome 19. Interestingly, in synchronized HL-60 cells, L30E DNA is replicated in the first minute of S-phase. Replication of the lamin gene early in S-phase may reflect a coupling between early replication and transcription of genes for S-phase-specific proteins such as lamins.

Amino Acid Sequence↗
PubMed1992

[Anti-rubella vaccine coverage in women 11-28 years of age: data on 5 local socio-health units of Veneto].

Selective rubella vaccination in the 11 years old girls, has been carried out in the Regione Veneto (Venetian Land) since 1974. The rubella immunization rate in teh women born between 1962 and 1978, in five sanitary districts, is 68.25%; the trend of increasing vaccination is continuing. Important differences in the organization of vaccination campaign were found among the five districts.

Adolescent↗
PubMed1988

Presence of transcription signals in two putative DNA replication origins of human cells.

We describe the purification and cloning of human DNA replicated at the onset of S phase in HL60 cells synchronized with aphidicolin. A survey of the overall structural properties of these sequences did not show any distinctive features except for an enrichment in Cot0 DNA. The two longer fragments were completely sequenced and studied in more detail. Both were shown to contain transcriptional signals associated with promoters and/or enhancers, such as the binding sites of Sp1, T antigen and nuclear factor III. In one instance, a binding site for a known cellular transcription factor (USF/MLTF) was located inside the sequence by footprinting. Accordingly, by CAT assay and Northern blot, the same sequence was shown to contain an active promoter. The significance of these findings with respect to the role of transcription in initiation of DNA replication at the origin is discussed. None of the tested fragments exhibited autonomously replicating sequence (ARS) activity in transfected cells. The problems connected with the detection of ARS activity in human cells are critically examined.

Aphidicolin↗
PubMed1987

Aspartate aminotransferase and alanine aminotransferase serum activities in small-for-date newborns.

The aspartate aminotransferase (AST) and alanine aminotransferase (ALT) serum activities were evaluated in the first 12 hrs of life in 26 newborns small-for-gestational age, and correlated with birth weight and gestational age. We found a positive correlation between the ALT serum activity and both birth weight and gestational age of newborns small-for-gestational age. Therefore, the serum activity of neonatal ALT better reflects intrauterine fetal growth in relation to cellular enzymatic pool increase of small-for-date newborns.

Alanine Transaminase↗
PubMed1985

Serum glutamic-oxaloacetic transaminase and glutamic-pyruvic transaminase activity in premature and full-term asphyxiated newborns.

The serum activity of SGOT and SGPT is one of the more specific parameters of liver cell injury both in adults and in the pediatric age-group. The determination of serum transaminase activity could offer a routine and rapid laboratory test for establishing the presence of hepatic cellular damage following intrauterine or perinatal asphyxia. In fact, it appears that there is a correlation between hypoxia and the increase in serum activity of transaminases in full-term and premature asphyxiated newborns. However, this increase is reversible up to the 30th day of life. The behavior of transaminase enzymatic activity in premature asphyxiated newborns compared to full-term asphyxiated newborns suggests a higher resistance of membranes to hypoxic-ischemic injuries and a lower enzymatic pool of cellular metabolism in premature newborns. Therefore, knowledge of the behavior of SGOT and SGPT activity may have important implications in the diagnosis and early treatment of perinatal asphyxia.

Alanine Transaminase↗
PubMed1984

Depression and anxiety in complex partial seizures.

In order to evaluate the effect of lateralization of epileptogenic lesions on mood changes (depression-mania) and anxiety (state and trait), twenty patients with complex partial seizures and nineteen controls were assessed with depression scales (Beck, Columbia M-D) and the State and Trait Anxiety Inventory. Nine patients had left temporal foci, eight had right foci, as assessed by the side of seizure onset during closed-circuit television-EEG telemetry recording. Left patients scored significantly higher than both right and control groups on depression and trait anxiety. Our results are consistent with those of previous reports on patients with localized epileptogenic and nonepileptogenic lesions. Patients with left side involvement seem more prone to experience dysphoric changes and depressive symptoms than those with right involvement.

Adult↗
PubMed1983

Glutamic-oxalacetic transaminase (SGOT) and glutamic-pyruvic transaminase (SGPT) in newborns in relation to the gestational age.

The transaminase enzymatic activity (SGOT-SGPT) was measured in the first 72h. of life, within the 7th day and on the 30th day of life in two groups of new borns i.e. full-term and premature ones with a gestational age less than or equal to 37 weeks. The premature babies were divided into two sub-groups: babies with a gestational ager less than or equal to 32 and greater than 32 weeks. Our results on the SGOT and SGPT activity in healthy full-term newborns agree with literature data, but indicate a lowering of the SGOT mean values at the 30th day of life. A similar lowering occurs at the 7th day of life; in premature newborns; these have lower SGOT values during the first 72h. of life than full-term newborns. Newborns with a gestational age of less than or equal to 32 weeks have higher SGOT values than newborns with a gestational age of greater than 32 weeks. The mean values of SGPT during the first days of life are higher in full-term than in premature newborns; there are no significant differences in the sub groups with different gestational age.

Aging↗