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Biomedical subjects

C Santoro

Publications and source records attributed to C Santoro.

At least 37 records · Page 2Linked to original sources
PubMed1991

In vitro activity of clarithromycin alone or in combination with other antimicrobial agents against Mycobacterium avium-intracellulare. Complex strains isolated from AIDS patients.

The activity of clarithromycin and five other antimicrobial agents, namely amikacin, rifampicin, rifabutin, clofazimine and ciprofloxacin, was assessed both by an agar dilution and a radiometric method in broth on 11 Mycobacterium avium-intracellulare complex (MAC) strains, recently isolated from AIDS patients. Minimum inhibitory concentrations (MICs) radiometrically determined were, in general, several times lower than MICs assessed in agar, probably because of a partial degradation of antimicrobials during the long incubation period needed for tests in solid medium. When tested in broth, rifabutin and clofazimine showed very low MICs 90 (0.24 and 0.78 microgram/ml, respectively). Ciprofloxacin and clarithromycin also had MICs90 in the range of peak serum levels (1.93 and 3.76 micrograms/ml, respectively). Moreover, all these antimicrobials are known to concentrate several times in macrophages. MICs90 were higher for amikacin (11 micrograms/ml) and for rifampicin (8 micrograms/ml). When clarithromycin was tested against three MAC strains in combination with another drug, it showed a synergistic effect only when combined with rifampicin. Some synergistic effect was observed also when combining clarithromycin with rifampicin and amikacin, whereas in combination with rifabutin and clofazimine there was only an additive effect.

Acquired Immunodeficiency Syndrome↗
PubMed1990

Characterization of two classes of opioid binding sites in Drosophila melanogaster head membranes.

Opioid receptors have been characterized in Drosophila neural tissue. [3H]Etorphine (universal opioid ligand) bound stereospecifically, saturably, and with high affinity (KD = 8.8 +/- 1.7 nM; Bmax = 2.3 +/- 0.2 pmol/mg of protein) to Drosophila head membranes. Binding analyses with more specific ligands showed the presence of two distinct opioid sites in this tissue. One site was labeled by [3H]dihydromorphine ([3H]DHM), a mu-selective ligand: KD = 150 +/- 34 nM; Bmax = 3.0 +/- 0.6 pmol/mg of protein. Trypsin or heat treatment (100 degrees C for 15 min) of the Drosophila extract reduced specific [3H]DHM binding by greater than 80%. The rank order of potency of drugs at this site was levorphanol greater than DHM greater than normorphine greater than naloxone much greater than dextrorphan; the mu-specific peptide [D-Ala2,Gly-ol5]-enkephalin and delta-, kappa-, and sigma-ligands were inactive at this site. The other site was labeled by (-)-[3H]ethylketocyclazocine ((-)-[3H]EKC), a kappa-opioid, which bound stereospecifically, saturably, and with relatively high affinity to an apparent single class of receptors (KD = 212 +/- 25 nM; Bmax = 1.9 +/- 0.2 pmol/mg of protein). (-)-[3H]EKC binding could be displaced by kappa-opioids but not by mu-, delta-, or sigma-opioids or by the kappa-peptide dynorphin. Specific binding constituted approximately 70% of total binding at 1 nM and approximately 50% at 800 nM for all three radioligands ([3H]etorphine, [3H]EKC, and [3H]DHM). Specific binding of the delta-ligands [3H][D-Ala2,D-Leu5]-enkephalin and [3H][D-Pen2,D-Pen5]-enkephalin was undetectable in this preparation.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

Joubert syndrome. Review of the fifty-three cases so far published.

Joubert's syndrome (JS) is an autosomal recessive disorder, which is characterised by a variable combination of central nervous, respiratory and eye anomalies. We review the clinical characteristics of the 53 so far reported children with Joubert's syndrome, stressing the importance of recognising the syndrome in the neonatal period, in order that specific and effective therapeutic measures be started as soon as possible.

Abnormalities, Multiple↗
PubMed1989

Increased Sp1 binding mediates erythroid-specific overexpression of a mutated (HPFH) gamma-globulin promoter.

The -198 T----C mutation in the promoter of the A gamma-globin gene increases 20-30 fold the expression of this gene in adult erythroid cells of patients (Hereditary Persistence of Fetal Hemoglobin, HPFH). We show here that this mutation creates a strong binding site, resembling a CACCC box, for two ubiquitous nuclear proteins, one of which is Sp1. The mutated promoter is four to five-fold more efficient than a normal gamma-globin promoter in driving expression of a CAT reporter plasmid when transfected into erythroid cells. The overexpression of the mutant is abolished by the introduction of an additional mutation disrupting the new binding site. No overexpression of the mutant is observed in non-erythroid cells, indicating that the ubiquitous factors bound on the mutated sequence must cooperate with erythroid specific factors.

Base Sequence↗
PubMed1988

A family of human CCAAT-box-binding proteins active in transcription and DNA replication: cloning and expression of multiple cDNAs.

The CTF/NF-I group of cellular DNA binding proteins recognizes the sequence GCCAAT and is implicated in eukaryotic transcription as well as DNA replication. Molecular analysis of human CTF/NF-I complementary DNA clones reveals multiple messenger RNA species containing alternative coding regions, apparently as a result of differential splicing. Expression and functional analysis establish that individual gene products can bind to GCCAAT recognition sites and serve both as promoter-selective transcriptional activators and as initiation factors for DNA replication.

Adenoviridae↗
PubMed1988

A comparison of peer-directed and teacher-directed employment interview training for mentally retarded adults.

Interview skills deficits may limit employment prospects of mentally retarded adults. Although numerous papers highlight the importance of interview skills, few have validated effective strategies for use with mentally retarded persons. Further, there has been a lack of research contrasting rival interview skills training strategies. The present study was conducted with two mentally retarded young adults. It contrasted peer-directed instruction, in which both participants were equally deficient in the target skills, with teacher-directed instruction. Results of the investigation indicated that instruction, rehearsal, and feedback may be effective strategies regardless of who provides instruction. Comparisons of teacher-directed and peer-directed instruction indicated little or no difference in the effectiveness of the two procedures. However, the peer-directed procedure involved considerably less staff time than did the teacher-directed procedure.

Adult↗
PubMed1987

Visualization of multiple opioid-receptor types in rat striatum after specific mesencephalic lesions.

In order to gain insight into a possible modulatory role for mu, delta, and kappa opioid receptors of the nigrostriatal dopaminergic pathway, we investigated the topographical organization of the receptors with respect to pre- and postsynaptic membranes. Dopaminergic terminals projecting from the substantia nigra to the corpus striatum were destroyed by unilateral injection of 6-hydroxydopamine into the substantia nigra. Quantitative receptor assays using highly specific radioligands were used to measure the density of striatal mu, delta, and kappa receptors before and after denervation. Denervation caused a 34 +/- 2% loss of striatal mu receptors and a 32 +/- 1% loss of striatal delta receptors on the lesioned side of the brain; in contrast, kappa receptors did not change significantly in density. Quantitative in vitro autoradiography was used to visualize the neuroanatomical pattern of receptors on lesioned and nonlesioned sides of the brain under the light microscope. Loss of mu receptors in striatal patches was striking in the ventrolateral areas of the striatum, whereas the most notable loss of delta receptors was found in the central striatum. Other brain areas did not differ significantly in mu receptor density between the lesioned and nonlesioned sides, as determined by autoradiography. These findings suggest that a high percentage of mu and delta receptors in the striatum are located on the nigrostriatal dopaminergic terminals and support the concept of a modulatory role for mu and delta opioid peptides in the nigrostriatal dopaminergic pathway.

Animals↗
PubMed1986

Cloning of the gene coding for human L apoferritin.

A recently reported cDNA clone coding for human promyelocytic L apoferritin, shows some differences with a liver L apoferritin cDNA. We have investigated if these differences are due to the expression of different genes or to an alternative transcription of an unique gene. In this paper we report data suggesting that a single gene is mainly expressed in several tissues examined. This gene has been cloned and characterized. Its sequence shows three introns: the exon sequence is identical to that of cDNA clone isolated from human liver. A minimum of five related pseudogenes have been also analysed. One of them is a processed pseudogene interrupted by an intron-like fragment.

Amino Acid Sequence↗
PubMed1986

Structure of gene and pseudogenes of human apoferritin H.

Ferritin is composed of two subunits, H and L. cDNA's coding for these proteins from human liver (1,2,3), lymphocytes (4) and from the monocyte-like cell line U937 (5) have been cloned and sequenced. Southern blot analysis on total human DNA reveals that there are many DNA segments hybridizing to the apoferritin H and L cDNA probes (1,2,4,6). In view of the tissue heterogeneity of ferritin molecules (7,8), it appeared possible that apoferritin molecules could be coded by a family of genes differentially expressed in various tissues (1,2). In this paper we describe the cloning and sequencing of the gene coding for human apoferritin H. This gene has three introns; the exon sequence is identical to that of cDNA's isolated from human liver, lymphocytes, HeLa cells and endothelial cells. In addition we show that at least 15 intronless pseudogenes exist, with features suggesting that they were originated by reverse transcription and insertion. On the basis of these results we conclude that only one gene is responsible for the synthesis of the majority of apoferritin H mRNA in various tissues examined, and that probably all the other DNA segments hybridizing with apoferritin cDNA are pseudogenes.

Apoferritins↗
PubMed1984

Cloning and sequencing of a full length cDNA coding for a human apoferritin H chain: evidence for a multigene family.

We have cloned a segment of cDNA from human liver coding for an apoferritin subunit, probably an H chain. Sequence comparison with the available protein sequence shows that our clone corresponds to a ferritin subunit present as a minor species in human spleen and placenta, but as major species in HeLa cells. Northern blot analysis shows the existence of only one band of similar size in human liver, HeLa cells, Daudi lymphoma and Hep3B hepatoma cell lines. In contrast, Southern blot analysis provides evidence for a multigene family.

Amino Acid Sequence↗
PubMed1984

Inhibition of eukaryotic tRNA transcription by potential Z-DNA sequences.

The effect of d(CA/TG)n DNA segments on tRNA transcription has been examined. Alternating purine-pyrimidine tracts were cloned at a long distance from, adjacent to, or within the coding sequence of a tRNAPro gene from Caenorhabditis elegans and shown to be able to assume the A-DNA conformation in vitro in physiological salt concentrations. The transcriptional level of these constructs was compared to that of normal tDNAPro by micro-injection into Xenopus laevis oocytes. Our results show a strong inhibitory effect by potential Z-DNA sequences only when these are placed in the flanking regions of the gene or when they are located between the elements (Box A and Box B) of the split promoter. Transcription was studied in parallel with supercoiled and linear DNA molecules carrying a d(CA/TG) stretch 124-bp long in front of the tRNAPro gene. The results show the same level of inhibition of Po/III transcription regardless of the topological status of the injected DNA.

Animals↗
PubMed1983

Cloning and sequencing of a full length cDNA coding for human retinol-binding protein.

We have isolated and sequenced a cDNA clone coding for human Retinol Binding Protein. The sequence indicates that Retinol Binding Protein is synthesized as a single polypeptide chain precursor which is then matured to the secreted protein by removal of a leader peptide. Southern and Northern blot analysis suggest that the gene is present in one or few copies per haploid genome and is transcribed in a single mRNA species.

Amino Acid Sequence↗
PubMed1983

Sequence of human haptoglobin cDNA: evidence that the alpha and beta subunits are coded by the same mRNA.

We have isolated and sequenced a cDNA clone coding for human haptoglobin. Our sequence shows that haptoglobin is very likely synthesized as a single polypeptide chain which is then cleaved at an Arg residue to generate its two characteristic alpha and beta subunit. Southern blot analysis suggests that there are at least two copies of the haptoglobin gene per haploid genome.

Amino Acid Sequence↗