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Biomedical subjects

G Calabrese

Publications and source records attributed to G Calabrese.

At least 73 records · Page 4Linked to original sources
PubMed1996

cDNA characterization and chromosomal mapping of two human homologues of the Drosophila dishevelled polarity gene.

The Drosophila dishevelled gene (dsh) encodes a secreted glycoprotein, which regulates cell proliferation, acting as a transducer molecule for developmental processes, including segmentation and neuroblast specification. We have isolated and characterized cDNA clones from two different human dsh-homologous genes, designated as DVL-1 and DVL-3. DVL-1 and DVL-3 putative protein products show 64% amino acid identity. The DVL-1 product is 50% identical to dsh and 92% to a murine dsh homologue (Dvl-1). Both human DVL genes are widely expressed in fetal and adult tissues, including brain, lung, kidney, skeletal muscle and heart. DVL-1 locus maps to chromosome 1p36 and DVL-3 to chromosome 3q27. DVL-1 locus on chromosome 1 corresponds to the murine syntenic region where Dvl-1 is located. DVL-1 and DVL-3 are members of a human dsh-like gene family, which is probably involved in human development. Although the precise role of these genes in embryogenesis is only conjectural at present, the structural and evolutionary characteristics suggest that mutations at their loci may be involved in neural and heart developmental defects.

Adaptor Proteins, Signal Transducing↗
PubMed1996

Microdeletions in interval 6 of the Y chromosome detected by STS-PCR in 6 of 33 patients with idiopathic oligo- or azoospermia.

It has been proposed that interval 6 of the human Y chromosome contains the gene or genes that control spermatogenesis (AZF, azoospermia factor). We have studied this region in 33 patients with oligo- or azoospermia, using PCR amplification of the YRRM1 (RBM1) gene and of 13 sequence-tagged sites (STSs), all mapping within interval 6. Six of the 33 patients showed no amplification of specific STSs, whereas there was no failure of amplification in normal male controls. We deduce that these six patients had microdeletions in interval 6 of the Y chromosome that correlated with the oligo- or azoospermia of these individuals. On biopsy of the testis, two of these patients showed a low number of germ cells, and four showed arrest with spermatides. We conclude that PCR amplification of Y-specific regions is a powerful and very sensitive tool for screening infertile men.

Adult↗
PubMed1996

FISH detection of mixed chimerism in 33 patients submitted to bone marrow transplantation.

Fluorescence in situ hybridization (FISH) and cytogenetic analysis were carried out in 33 transplanted patients suffering from different hematologic disease using probes for X and Y chromosomes and ABL and BCR genes. FISH showed that recipient cells were invariably present during post-transplant follow-up. Stable minimal residual disease was associated with clinical and hematologic remission, while a progressive increase of host cells was strictly related with disease relapse. Cytogenetic investigation on the same samples showed recipient cells only in few cases. It was concluded that FISH analysis is useful for: (1) characterizing cases in which standard cytogenetic analysis has failed; (2) detecting host cells in sex-mismatched transplanted patients; and (3) evaluating Ph-negative CML with the BCR/ABL rearrangement. The possibility of detecting chromosome rearrangements in interphase nuclei using FISH analysis improves diagnosis and prediction of disease evolution and prompts earlier therapeutic approaches.

Adolescent↗
PubMed1996

Human homologue sequences to the Drosophila dishevelled segment-polarity gene are deleted in the DiGeorge syndrome.

DiGeorge syndrome (DGS) is a developmental defect of some of the neural crest derivatives. Most DGS patients show haploinsufficiency due to interstitial deletions of the proximal long arm of chromosome 22. Deletions of 22q11 have also been reported with patients with the velocardio-facial syndrome and familial conotruncal heart defects. It has been suggested that the wide phenotype spectrum associated with 22q11 monosomy is a consequence of contiguous-gene deletions. We report the isolation of human cDNAs homologous to the Drosophila dishevelled (dsh) segment-polarity gene. Sequences homologous to the 3' UTR of these transcripts (DVL-22) were positioned within the DGS critical region and were found to be deleted in DGS patients. Human DVL mRNAs are expressed in several fetal and adult tissues, including the thymus and, at high levels, the heart. Two transcripts, 3.2 and 5kb, were detected, in northern blot analysis, with different expression patterns in the surveyed tissues when different cDNAs were used. The isolated cDNAs exhibit high amino acid homology with the mouse and Xenopus Dvl-1 gene, the only other vertebrate dsh homologues so far isolated. The pivotal role of dsh in fly development suggests an analogous key function in vertebrate embryogenesis of its homologue genes. Since DGS may be due to perturbation of differentiation mechanisms at decisive embryological stages, a Dsh-like gene in the small-region overlap (SRO) might be a candidate for the pathogenesis of this disorder.

Adaptor Proteins, Signal Transducing↗
PubMed1995

Asymmetry of temporal lobe phosphorous metabolism in schizophrenia: a 31phosphorous magnetic resonance spectroscopic imaging study.

In vivo 31Phosphorous magnetic resonance spectroscopic imaging (31P MRSI) was performed on 18 chronic schizophrenic patients and 14 normal controls to determine if there was asymmetry of high-energy phosphorous metabolism in the temporal lobes of schizophrenic patients. Temporal lobe phosphorous metabolites were also correlated with severity of psychiatric symptomatology as assessed by the Brief Psychiatric Rating Scale (BPRS). Schizophrenics demonstrated significantly higher right relative to left temporal phosphocreatine/adenosine triphosphate (PCr/ATP), phosphocreatine/inorganic phosphate (PCr/Pi), and PCr as well as significantly lower right relative to left temporal ATP. There were no asymmetries of temporal lobe phosphorous metabolites in the control group. In addition, both left temporal PCr and the degree of asymmetry of temporal lobe PCr were highly correlated with the thinking disturbance subscale of the BPRS. This study provides further support for temporal lobe metabolic asymmetry in schizophrenia and its possible association with clinical symptoms.

Adult↗
PubMed1995

Identification of multiple transcribed sequences from the spinal muscular atrophy region of human chromosome 5.

We report the isolation and characterization of novel expressed sequences from the spinal muscular atrophy (SMA) region on human chromosome 5q13. Based on the sequence homology studies these cDNAs were grouped in four classes, one of which shows extensive homologies with the beta-glucuronidase (BG) gene, differing in exon arrangement. The other cDNAs do not show any strong homology with known DNA sequences.

Base Sequence↗
PubMed1995

Fetal translocation between chromosomes 2, 18, and 21 resolved by fish.

An apparently balanced t(2q;21q) translocation was discovered in fetal blood and amniocytes of a 22-week fetus, monitored because of ultrasonographic evidence of a heart disease. FISH (fluorescence in situ hybridization) analysis disclosed a complex translocation between chromosomes 2q, 18q, and 21q, which was inherited from the healthy mother. This observation corroborates the usefulness of molecular cytogenetic techniques in raising the quality of prenatal diagnosis and detecting subtle rearrangements not resolved by standard cytogenetics.

Adult↗
PubMed1995

Retrospective investigation of hematopoietic chimerism after BMT by PCR amplification of hypervariable DNA regions.

We report on nine patients submitted to BMT with sex-matched donors and investigated by means of PCR amplification of the VNTRs ApoB, D1S80, DXS52, and D17S5. In all cases it was possible to detect a polymorphism able to distinguish between donor and patient cells, thus allowing us to recognize the presence of complete or mixed chimerism. In eight patients PCR analysis showed a complete chimerism during the entire follow-up. Only one of these patients relapsed, while the others are alive and without any sign of relapse 56.2 months (mean) after BMT. Mixed chimerism was detected in only one patient, who relapsed 3 months after this finding. These results confirm the usefulness of the study of PCR-amplified VNTRs in the assessment of marrow engraftment after BMT, mostly in sex-matched transplants where, in the absence of specific chromosome rearrangements, cytogenetic or FISH analysis cannot be used.

Adolescent↗
PubMed1995

Recovery functions of early cortical median nerve SSEP components: normative data.

The recovery functions of parietal P14-N20, N20-P27 and frontal P22-N30 amplitudes were assessed in 17 healthy controls aged 20-50 years by means of the paired stimulus technique. One unpaired and 4 paired stimuli with interstimulus intervals (ISIs) of 25, 50, 75 and 100 msec were cyclically presented in a single run. Responses to the unpaired stimulus were subtracted off-line from paired stimulus responses. The highest suppression was reached at shorter ISIs for components with shorter latencies. The mean suppression of P22-N30 was influenced by the subject's age, being greater in younger subjects. Normative data are reported.

Adult↗
PubMed1995

Duplication Xp22.2 and pseudoisodicentric Yq detected by FISH and PCR in a sterile male.

A chromosome mosaicism with two cell lines was diagnosed in a sterile man. One cell line had a 45, -Y, dup (X) (p22.2) karyotype and accounted for 83% of lymphocytes analyzed. Fluorescence in situ hybridization (FISH) analysis with specific X and Y probes excluded a translocation between the short arms of the X and Y chromosomes and showed that Xp duplication involved a region containing the DXS85 locus, distal to the ZFX and DSS sites. The other cell line consisted of a diploid karyotype with a rearranged Y chromosome, which was shown to be a pseudoisodicentric Yq by FISH. Moreover, FISH with a specific probe for the AZF locus and polymerase chain reaction using Yq SY108 and SY121 primers showed no signals for this region, possibly accounting for the azoospermia in this patient.

Adult↗
PubMed1995

Effects of chronic alcohol abuse and HIV infection on brain phosphorus metabolites.

We examined the effects of human immunodeficiency virus (HIV) infection and chronic alcohol consumption on cerebral phosphorus metabolites to determine if chronic alcohol abuse is a risk factor for the progression of neurological effects of HIV infection. We studied 15 HIV- alcoholics, 8 HIV- light/nondrinkers, 32 HIV+ alcoholics, and 41 HIV+ light/nondrinking men, with both HIV+ groups having similar CD4 lymphocyte counts. We used localized 31-phosphorus magnetic resonance spectroscopy after magnetic resonance imaging to examine two brain volumes in superior white matter and subcortical gray matter. Chronic alcohol consumption was associated with reduced white matter concentrations of phosphodiester (PDE) and phosphocreatine (PCr). Also in the white matter, acquired immune deficiency syndrome (AIDS) and AIDS-related complex (ARC) were associated with reduced concentrations of PDE and PCr, compared with both HIV- and clinically asymptomatic HIV+ subjects. Because no alcohol-by-HIV interactions were detected, the effects of HIV infection and alcohol abuse were cumulative. This is reflected in a successive decrease of white matter PDE and PCr concentrations in the order HIV- light/nondrinkers/HIV- alcoholics/HIV+ light/nondrinkers/HIV+ alcoholics. Subcortical gray matter PDE concentrations were lower in ARC/AIDS alcoholics than in HIV- light/nondrinking individuals. These findings suggest altered brain phospholipid metabolites and energy metabolites with alcohol abuse and HIV infection. They demonstrate that the adverse metabolic effects of HIV on the brain are augmented by chronic alcohol abuse.

AIDS Dementia Complex↗
PubMed1995

The gene (LGALS3BP) encoding the serum protein 90K, associated with cancer and infection by the human immunodeficiency virus, maps at 17q25.

Levels of a 90-kDa tumor associated protein, designated 90K (gene symbol LGALS3BP), have been found elevated in the serum of patients with cancer and in those infected by the human immunodeficiency virus (HIV). 90K appears to be implicated in immune response associated with natural killer (NK) and lymphokine-activated killer (LAK) cell cytotoxicity. Using fluorescence in situ hybridization the full length 90K cDNA has been localized to chromosome 17q25.

Blood Proteins↗
PubMed1995

Calcitriol pulse therapy for severe hyperparathyroidism or calcium salts as phosphate binders in renal dialysis patients?

The concurrent use of calcitriol (CAL) pulse therapy to reduce parathyroid hormone (PTH) secretion and of calcium (Ca) salts as the most appropriate phosphate binders was evaluated for over 1 year in a group of 14 patients with good divalent ion control on CaCO3 therapy but with increasing levels of serum intact PTH. CAL pulse therapy was effective and safe in only 2 patients; in the remaining subjects it resulted in hypercalcemia and/or hyperphosphatemia, not reversed by adjusting the dialysate Ca concentration and or CaCO3 dose, and had to be stopped. Therefore, CAL pulse therapy does not seem to be compatible with Ca salts which, in our opinion, deserve priority in the therapy of renal dialysis patients.

Alkaline Phosphatase↗