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Biomedical subjects

A Baldini

Publications and source records attributed to A Baldini.

At least 109 records · Page 6Linked to original sources
PubMed1994

Mapping of the gene coding for a paraneoplastic encephalomyelitis antigen (HuD) to human chromosome site 1p34.

A cDNA clone coding for a human brain protein (HuD), which is highly homologous to the Drosophila neuronal determination protein Elav and elicits antibody formation in a high proportion of patients with paraneoplastic encephalomyelitis, was used to isolate a lambda phage recombinant clone, including a large fragment of the relevant human genomic region. The fragment proved to be an efficient probe for the precise subregional mapping of the gene by molecular in situ hybridization onto extended human prometaphase chromosomes. Analysis of banded metaphases with clear hybridization signals pointed unequivocally to the localization of the HuD gene to human chromosome band 1p34.

Chromosome Mapping↗
PubMed1994

Concurrent mapping of an adenovirus 5/SV40 integration site and the U1 snRNA cluster (RNU1) within 400 kb of the chromosome region 1p36.1.

Previous reports from our group suggested the preferential integration of the viral construct Ad5/SV40 at the short arm subtelomeric region of human chromosome 1. The present study narrows the region of viral integration to site 1p36.1 in a close cytogenetic overlap with the U1 snRNA gene cluster (RNU1) within a distance necessarily smaller than 400 kb as suggested by the size of the YAC in which the two markers were found to coexist. This finding supports the hypothesis that the chromosomal site in question may have a constitutional propensity to genetic recombination.

Adenoviruses, Human↗
PubMed1993

Family with 22-derived marker chromosome and late-onset dementia of the Alzheimer type: II. Further cytogenetic analysis of the marker and characterization of the high-level repeat sequences using fluorescence in situ hybridization.

We have further characterized an unusual 22p+ marker chromosome with a double nucleolus organizer region (dNOR) previously identified in a family with late-onset dementia of the Alzheimer type. G-banding and morphology of the marker's q arm were typically normal. However, the p+ arm had a terminal cytological satellite and a GT-positive region at the midpoint. Standard C-banding documented 2 C-positive regions: one was associated with the primary centromere; the other, which was at the midpoint of the p arm, was not associated with a constriction. With replication-banding, there was a darkly staining region in the middle of the p+ arm that resembled the pericentromeric region of a chromosome 21 or 22. Fluorescence in situ hybridization with pXlr 101, a probe recognizing the full repeating unit of rDNA, indicated that the marker had an unusually larger rDNA region; with pU 1.2, a probe recognizing the human rDNA promoter, the signal was a doublet. The marker had 2 signals with a beta-satellite probe, and a second signal in addition to that present at the primary centromere under low stringency with alpha-satellite probes and a classic satellite probe. Immunostaining of chromosome spreads after R-banding and ultraviolet (UV) denaturation showed that the major portion of the marker's p arm was highly methylated.

Aged↗
PubMed1993

Mapping on human and mouse chromosomes of the gene for the beta-galactoside-binding protein, an autocrine-negative growth factor.

The structural gene for beta-galactoside-binding protein (Lgals-1), a cell growth regulatory molecule and cystostatic factor, is assigned to the E-region of mouse chromosome 15 and to the region q12-q13.1 of human chromosome 22. The evolutionary conservation of these two regions has been previously suggested from comparative mapping of several loci. These include the murine SIS oncogene (Pdgfb) and its human homolog, the platelet-derived growth factor-beta polypeptide, PDGFB. The findings presented here extend the genetic homology of the two regions.

Animals↗
PubMed1993

Molecular cytogenetic characterization of the DiGeorge syndrome region using fluorescence in situ hybridization.

DiGeorge syndrome (DGS) is a developmental defect characterized by cardiac defects, facial dysmorphism, and mental retardation. Several studies have described a critical region for DGS at 22q11, within which the majority of DGS patients have deletions. We have isolated nine cosmid and three YAC clones using previously described and newly isolated probes that have been shown to be deleted in many DGS patients. Using fluorescence in situ hybridization and digital imaging, we have mapped and ordered these clones relative to the breakpoints of two balanced translocations at 22q11 (one in a DGS patient and one in the unaffected parent of a DGS child). Our data indicate that the breakpoint in the unaffected individual distally limits the DGS critical region (defined as the smallest region of overlap), while proximally the region is limited by repeat-rich DNA. The critical region includes the balanced translocation breakpoint of the DGS patient that presumably disrupts the gene causing this syndrome.

Animals↗
PubMed1993

An alphoid DNA sequence conserved in all human and great ape chromosomes: evidence for ancient centromeric sequences at human chromosomal regions 2q21 and 9q13.

Using vector-CENP-B box polymerase chain reaction (PCR) we isolated and cloned from a human chromosome 21-specific plasmid library, a 1 kb DNA sequence, named p alpha H21. In in situ hybridization experiments, p alpha H21 hybridized, under high stringency conditions, to the centromeric region of all the human, chimpanzee, gorilla and orangutan chromosomes. On human chromosomes p alpha H21 also identified non-centromeric sequences at 2q21 (locus D2F33S1) and 9q13 (locus D9F33S2). The possible derivation of these sequences from ancestral centromeres is discussed. Sequence analysis confirmed the alphoid nature of the whole p alpha H21 insert.

Animals↗
PubMed1993

MULTIPRINS: a method for multicolour primed in situ labelling.

With this fast and simple MULTIPRINS protocol we show simultaneous mapping of multiple repetitive sequences by sequential cycles of primed in situ (PRINS) labelling with various primers and reporter molecules. Differentially labelled DNA sequences synthesized in situ were visualized by directly incorporated rhodamine-4-dUTP, by fluorescein isothiocyanate and Cy5 using digital imaging microscopy. This further development of the PRINS method enhances its potential as an alternative to traditional in situ hybridization.

Base Sequence↗
PubMed1993

Combined treatment with growth hormone and luteinizing hormone releasing hormone-analogue (LHRHa) of pubertal children with familial short stature.

We evaluated the 12 month growth of 18 pubertal children with familial short stature randomly assigned to clinical follow-up (group A), GH treatment alone (group B) and GH+LHRH analogue (LHRHa) treatment (group C). Height velocity increased significantly compared to baseline in groups A and B (4.7 +/- 0.4 vs 6.6 +/- 0.6 and 4.4 +/- 0.3 vs 8 +/- 1 respectively), but not in C (5 +/- 0.5 vs 6.5 +/- 0.4). Moreover in group B height and height prognosis standard deviation score SDS) also were higher (-2.2 +/- 0.2 vs -1.7 +/- 0.2 and 1.8 +/- 0.3 vs -1 +/- 0.2, respectively). Comparisons among the groups showed a significant increase in group B vs the other groups of height velocity SDS (3.9 +/- 1.3 vs 0.4 + 1 and 0.3 +/- 0.7) and of height prognosis SDS (-1 +/- 0.2 vs -2.4 +/- 0.3 and -2.4 +/- 0.3). In conclusion, after one-year treatment, GH seems to be more effective in stimulating growth than GH +/- LHRHa, even if studies of longer duration and/or follow-up are needed.

Adolescent↗
PubMed1993

Isolation of a putative transcriptional regulator from the region of 22q11 deleted in DiGeorge syndrome, Shprintzen syndrome and familial congenital heart disease.

A wide spectrum of birth defects are caused by deletions of the DiGeorge syndrome critical region (DGCR) at human chromosome 22q11. Over one hundred such deletions have now been examined and a minimally deleted region of 300kb defined. Within these sequences we have identified a gene expressed during human and murine embryogenesis. The gene, named TUPLE1, and its murine homologue, encodes a protein containing repeated motifs similar to the WD40 domains found in the beta-transducin/enhancer of split (TLE) family. The TUPLE1 product has several features typical of transcriptional control proteins and in particular has homology with the yeast Tup1 transcriptional regulator. We propose that haploinsufficiency for TUPLE1 is at least partly responsible for DiGeorge syndrome and related abnormalities.

Abnormalities, Multiple↗
PubMed1993

Low-copy-number repeat sequences flank the DiGeorge/velo-cardio-facial syndrome loci at 22q11.

DiGeorge syndrome and velo-cardio-facial syndrome are associated with deletions within 22q11. In attempting to refine the shortest region of overlap for these syndromes we have employed fluorescence in situ hybridisation. The results obtained for some probes indicate the presence of low-copy-number repeat families dispersed through proximal 22q. Several primate species have been examined for the presence or absence of two sequences mapping to pter-22q11. The results suggest a relatively recent evolutionary origin for these sequences and the loss of one sequence during the course of primate evolution.

Animals↗
PubMed1992

Simultaneous visualization of seven different DNA probes by in situ hybridization using combinatorial fluorescence and digital imaging microscopy.

Combinatorial labeling of probes (i.e., with two or more different reporters) increases the number of target sequences that can be detected simultaneously by fluorescence in situ hybridization. We have used an epifluorescence microscope equipped with a digital imaging camera and computer software for pseudocoloring and merging images to distinguish up to seven different probes using only three fluorochromes. Chromosome-specific centromere repeat clones and chromosome-specific "composite" probe sets were generated by PCR in which different mixtures of modified nucleotides, including fluorescein-conjugated dUTP, were incorporated. Cosmid clones were labeled similarly by nick-translation. The technique has been used to delineate the centromeres of seven different human chromosomes, on both 4',6-diamidino-2-phenylindole-stained metaphase spreads and interphase nuclei, to map six cosmid clones in a single hybridization experiment and to detect chromosome translocations by chromosome painting. Multiparameter hybridization analysis should facilitate molecular cytogenetics, probe-based pathogen diagnosis, and gene mapping studies.

Centromere↗
PubMed1992

Methylation of the 5' flanking sequences of the ribosomal DNA in human cell lines and in a human-hamster hybrid cell line.

In a human lymphoblastoid cell line (Z83) in which rDNA genes on chromosome 22 are amplified but transcribed at a low level, immunocytological studies with antibodies to 5 methylcytidine provided evidence for hypermethylation of the rDNA. The extent of methylation of the 5' flanking sequences of the ribosomal DNA was examined by comparing the size of restriction fragments obtained by digestion of genomic DNA with EcoRI and HpaII or EcoRI and MspI. Southern blots indicated hypermethylation of the 5' flanking sequences of many copies of rRNA genes in these cells, but not in a control lymphoblastoid cell line without rDNA amplification. Results obtained with a somatic hybrid human-hamster cell line, in which the rRNA genes on the single human chromosome 22 are inactive, showed that only a small fraction of the CCGG sites in the 5' flanking sequences of the transcriptionally silent rRNA genes in this hybrid were methylated. Since inactive rRNA genes can show such a minimal level of methylation, it is likely that the extreme hypermethylation of the amplified rRNA genes in Z83 occurred in association with their inactivation rather than following it.

Animals↗
PubMed1992

Generation and characterization of a human chromosome 9 cosmid library.

A cosmid library has been constructed from the hamster-human hybrid cell line PK-87-9, which contains chromosome 9 as its sole known human component. Ten thousand colonies were produced, of which approximately 200, or 2%, contain human material. Fifty of these 200 were regionally mapped by an Alu-primed PCR product hybridization procedure. These cosmids were localized to all regions of chromosome 9, but were especially concentrated in the distal portion of 9q. The map location derived by the Alu-primed PCR product hybridization procedure was compared to the map location derived by fluorescent in situ hybridization. Assignment of chromosomal location by the two methods was correspondent in all but a few cases. The presumptive presence of HTF islands was investigated for 130 cosmids by digestion with the restriction enzyme NotI. Twenty percent of cosmids contained at least one NotI site. A number of simple sequence repeat polymorphisms identified from the cosmid set were characterized and will provide a link between the genetic and physical maps for this chromosome.

Animals↗