Human endogenous retroviral sequences: possible roles in reproductive physiopathology.
Explore the source record for details and available documents.
Biomedical subjects
Publications and source records attributed to D Taruscio.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Central neurocytoma is a benign, slow-growing neoplasm with favourable prognosis. Biomolecular analysis has failed to demonstrate significant alterations, and no cytogenetic alterations have been reported. In this study we demonstrate chromosome 7 gain in three of nine neurocytomas (33%). Traditional cytogenetic analysis performed in four of the nine cases identified trisomy 7 as the sole chromosomal abnormality in one case. Interphase cytogenetics utilizing fluorescent in situ hybridization (FISH) on cell suspensions from formalin-fixed paraffin-embedded tumour tissue performed in all nine cases detected trisomy 7 in two more cases and tetrasomy in another. Our results suggest that chromosome 7 gain is a feature of neuroectodermal tumorigenesis, possibly conferring growth advantage on the neoplastic cells. FISH on interphase nuclei is a valuable adjunct in the genetic evaluation of rare central nervous system neoplasms with low baseline proliferative activity.
Explore the source record for details and available documents.
Double fluorescence in situ hybridization with DNA probes specific for the (peri)centromeric regions of chromosomes 3, 7, 9, 11, 12, 18, and X was performed on fresh isolated nuclei and frozen tissue sections prepared from 2 nodular hyperplasias, 2 adenomas, and 7 papillary carcinomas of the thyroid in order to detect numerical chromosomal changes. Numerical chromosomal aberrations were found in all malignant specimens examined. A consistent presence of at least two trisomies was detected in most cases, especially in the follicular variant specimens; the highest degree of trisomy was observed for chromosome 12. Isolated monosomies of moderate degree for different chromosomes were found in 1 adenoma and 2 papillary carcinomas. Severe monosomy of chromosome 9 was the only significant feature observed in the single metastatic papillary carcinoma.
Fluorescence in situ hybridization and 3-D image analysis were combined to study the distribution of specific chromosome subdomains through the course of the cell cycle in cultured mouse lymphocytes. DNA probes specific for major satellite DNA, minor satellite DNA, telomeric DNA and to chromosome X-, 8-, and 14-specific subsatellite DNA sequences were used. We demonstrate that a redistribution of the chromatin occurs during the cell cycle in the interphase nucleus, and that the profile of the rearrangement is highly dependent on the nature of the domain considered (centromeres, telomeres, or subsatellite regions). However, the relative arrangement of chromosome homologs to each other does not appear to be spatially defined or regulated.
Trisomy of chromosome 12 has been frequently described in various neoplasms, particularly in tumors of the female genitourinary tract. Fluorescence in situ hybridization with a centromeric repetitive DNA probe, specific for chromosome 12, was done to detect such cytogenic changes on frozen-tissue sections from 10 cases of ovarian sex cord stromal tumors. The case series was composed by granulosa cell tumors (four cases), fibromas (four cases), thecoma (one case), and Sertoli-Leydig cell tumor (one case). In granulosa cell tumors, the range of trisomy was 12 to 32% and in fibromas 8 to 22%, whereas in the single case of thecoma trisomy was present in 8% and in the Sertoli-Leydig cell tumor in 4% of the nuclei examined. These results represent an additional series of cases of trisomy 12 in ovarian neoplasms, namely, in ovarian sex cord stromal tumors.
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.
A region of chromosome 9, surrounding the interferon-beta (IFNB1) locus and the interferon-alpha (IFNA) gene cluster on 9p13-p22, has been shown to be frequently deleted or rearranged in a number of human cancers, including leukemia, glioma, non-small-cell lung carcinoma, and melanoma. To assist in better defining the precise region(s) of 9p implicated in each of these malignancies, a combined genetic and physical map of this region was generated using the available 9p markers IFNB1, IFNA, D9S3, and D9S19, along with a newly described locus, D9S126. The relative order and distances between these loci were determined by multipoint linkage analysis of CEPH (Centre d'Etude du Polymorphisme Humain) pedigree DNAs, pulsed-field gel electrophoresis, and fluorescence in situ hybridization. All three mapping approaches gave concordant results and, in the case of multipoint linkage analysis, the following gene order was supported for these and other closely linked chromosome 9 markers present in the CEPH database: pter-D9S33-IFNB1/IFNA-D9S126-D9S3-D9S19 -D9S9/D9S15-ASSP3-qter. This map serves to extend preexisting chromosome 9 maps (which focus primarily on 9q) and also reassigns D9S3 and D9S19 to more proximal locations on 9p.
Molecular cloning studies have now identified five structurally homologous genes encoding the biosynthesis of the human dopamine receptors, DRD1, DRD2, DRD3, DRD4, and DRD5. Two of these dopamine receptors (DRD1 and DRD5) are encoded by intronless genes. To ascertain whether there are other intronless genes that share identity with the gene (DRD5) encoding the DRD5 receptor, we used a cloning method based on the polymerase chain reaction (PCR). Human genomic DNA was amplified by PCR with oligodeoxyribonucleotides (oligos) based on the DRD5 nucleotide (nt) sequence. Amplification of nt sequences between these oligos allowed the isolation of two independent intronless genes that share identity with DRD5. The full-length clones have also been isolated by screening human genomic libraries. The deduced amino acid sequences for these genes, PG-1 and PG-2, share 91% and 92% identity to DRD5, respectively. However, each of the genes contains differences in the coding regions that would render these genes incapable of encoding functional receptors. Thus, the human genome contains at least two DRD5 pseudogenes, consistent with in situ human chromosomal hybridization analysis which reveals the presence of two pseudogenes.
To verify how the components of the capillary wall are modified in the course of AIDS we studied the brain cortex from nine cases with AIDS. Cellular and extracellular components were delineated using antibodies for laminin and collagen IV for basement membranes and glial fibrillary acidic protein for astrocyte foot processes. We found a marked increase in reactivity for laminin in the basement membranes of capillary walls and hypertrophy and hyperplasia of astrocyte foot processes around vessels, when compared to control cortical tissue. We suggest that modifications of brain capillary wall may have a role in the pathogenesis of neurological disfunction in AIDS.
Retroviruses have the ability to integrate into the genome of their host, in many cases with little apparent sequence or site specificity. However, relatively few studies have addressed more general features of chromosomal integration. In this study we directly visualized the chromosomal organization of three representative endogenous retroviruses by in situ hybridization. Because there are 50-1000 copies of each of these retroviruses in the genome, it was possible to evaluate repeated integration events. Each retroviral sequence exhibited a unique and markedly different integration pattern. In order to characterize more precisely the chromosomal domains targeted by each retrovirus, later replicating domains were differentially labeled. Additionally, prototypic SINES and LINES (short and long interspersed reiterated sequences), which are inhomogeneously distributed on chromosome arms, were simultaneously detected. Retroviral copies of greater than or equal to 2 kb were found (i) exclusively in a discrete set of later replicating domains, most of which have the staining characteristics of constitutive heterochromatin, (ii) widely represented in disparate types of chromosome domains, or (iii) almost completely confined to CpG Alu-rich regions that are known to be early replicating. Retroviral elements in Alu-rich domains would be expected to be actively transcribed in all cells. Surprisingly, hybridization to blots of brain RNA showed an approximately 25 fold lower level of transcripts from these Alu associated elements than from retroviral sequences restricted to later replicating, heterochromatic domains. Retroviral insertions may subvert more typical transcriptional characteristics of a domain. The present results indicate that there are highly specific integration patterns for each endogenous retrovirus that do not readily relate to their sequence or particle classification. Each host genome may utilize these elements for contrary, and possibly beneficial functions.
To improve the devices used in dental implantology, a new experimental supporting element has been developed. The device, made of titanium, poly(methylmethacrylate) and Dacron tissue, has been tested for the osteointegrability of its outer Dacron coat by implants in mandibular bone of rabbits. The Dacron filamentous tissue became incorporated by the bone at 3 month post-implantation. This might provide a reliable mechanical anchorage of the device and a barrier against epithelial proliferation and microbial contamination. Preliminary results relating to in vitro evaluation of the poly(methyl methacrylate)-Dacron fixation strength predict favourable mechanical behaviour at this interface and in the complete implanted device.
The ultrastructural expression of laminin and fibronectin was studied in human colonic mucosa with a pre-embedding immunoperoxidase technique. Both antigens were present in epithelial basement membrane. The lamina densa was uniformly and homogeneously immunostained by both fibronectin and laminin, while the lamina rara showed discrete, positive sites occasionally connecting the lamina densa with the epithelial plasma membrane. In the lamina reticularis, fibronectin was diffusely positive, while laminin showed a discontinuous positivity only in the uppermost region in vicinity of the lamina densa. Collagen fibrils were regularly decorated by fibronectin-positive material. Basement membranes in the capillary wall showed a similar pattern of reactivity both with laminin and fibronectin. These results point out that laminin as well as fibronectin are integral components of intestinal mucosa basement membranes.
The subcellular localization of sulphated glycoconjugates was determined at the ultrastructural level by using the high iron diamine (HID) technique for sulphate groups in the absorptive cells of human colonic mucosa. Stained material was observed on the apical plasma membrane, in intracytoplasmic vesicles and in the Golgi complex. In this organelle, the last two or three cisternae of the trans side and the trans-Golgi network (TGN) were labelled, as well as a variable number of coated and noncoated vesicles facing the trans side and surrounding trans-Golgi network. These findings point to the trans side of the Golgi apparatus and trans-Golgi network as the subcompartments functionally involved in the sulphation of glycoconjugates.
The glycocalyx of absorptive cells in large intestinal hyperplastic polyp was characterized histochemically at the electron microscope level by the use of the Alcian Blue pH 2.5 and high iron diamine techniques with the aim of comparing their ability in preserving the fine reticular network of the structure. Both the reagents stained glycocalyx, indicating the presence of sulphated acidic glycoconjugates. However, they showed different degrees of condensation of the reactive sites. Alcian Blue preserved its filamentous appearance better.
The clinical features of our cases demonstrated some of the already known characteristics of the variable spectrum of HIV infection. DA are the most important risk category in Italy. 10% of the ARC cases evolved into AIDS during a 12-month follow-up, on average. The most frequent OI in our AIDS cases were PCP, C. albicans esophagitis and chronic mucocutaneous ulcers. An high percentage of neurologic involvement from HIV was observed, and malignancies were encountered in AIDS (3 KS and 1 undifferentiated B lymphoma) as well as in ARC (1 Hodgkin's lymphoma). Statistically, significant worsening of the immunologic situation is evident as the disease progresses from LAS to AIDS. Activated B lymphocytes represent most of the cells of the germinal center during the hyperplastic stage of lymphadenopathy. Reversal of the T4/T8 ratio appears early during the initial stage of lymphadenopathy and is due to a decrease of CD4 and a relative increase of CD8. Also, destruction of the follicular dendritic cells is an early feature which becomes more evident as the disease advances and the lymph node evolves toward progressive involution. Activated B-lymphocyte augmentation with polyclonal Ig secretion appears to be related to T-independent B stimulation by coinfection such as CMV, EBV and HBV. The increase of cytotoxic/suppressor lymphocytes seems to be partly related to the excessive activation of B lymphocytes and partially directed to the cells infected by HIV or coated with its proteins (6,7,8,9). The destruction of follicular dendritic cells has been interpreted not only as a killer effect of the virus but also as a result of the intervention of CTL sensitized to the cells containing the virus (10,11). Their destruction may contribute to the impaired recognition of soluble antigen which is one of the main features of the immune deficiency of HIV infection (9,13,16).
Twenty-five cases originally diagnosed as malignant histiocytosis/true histiocytic lymphoma were reviewed according to both pathological and clinical criteria. Microscopically, they were characterized by large, pleomorphic tumour cells showing variable degrees of atypia and phagocytic activity. The growth more often appeared as diffuse, being limited to the sinuses in only two cases. Cytochemistry on touch imprints showed tumour cells strongly positive for acid phosphatase and alpha-naphthyl-acetate esterase in all the samples tested. Immunohistochemistry on paraffin embedded sections using specific antisera showed tumour cell positivity for lysozyme in 12 of 25 cases, for alpha 1-antitrypsin in 24 of 25 cases and for alpha 1-antichymotrypsin in all 25 cases. Immunophenotyping on frozen-sections in three cases displayed a clear-cut reactivity of the neoplastic cells with the monoclonal antibody OKM1. Clinically, the disease more often presented with B-symptoms, lymphadenopathy and mediastinal involvement. In the majority of the patients (18/25) it had a fatal and rapid course, despite therapy (median survival: 9 months; mean survival: 12 months). The presence of B-symptoms and bulky disease appeared as the only factors influencing the prognosis, both suggesting a more aggressive course of the tumour.