PubMed Health⌕ Search

Biomedical subjects

F Pasquali

Publications and source records attributed to F Pasquali.

At least 19 recordsLinked to original sources

Phage types, ribotypes and tetracycline resistance genes of Salmonella enterica subsp. enterica serovar Typhimurium strains isolated from different origins in Italy.

The tetracycline resistance (tet) gene patterns of 52 tetracycline resistant Salmonella enterica subsp. enterica (S.) serovar Typhimurium isolates collected from animals, food of animal origin, and humans in Italy, were investigated to evaluate whether the tet gene patterns could be used for strain differentiation in addition to phage typing and ribotyping. The detection of tet genes was performed by specific PCR assays. Ribotyping was performed automatically using PvuII as restriction enzyme. Ten different ribotyping patterns were detected. All isolates were positive for at least one of the tet genes studied and six different tet gene patterns were observed. Ribotyping and tet gene patterns showed discriminatory indices of 0.741 and 0.812, respectively. Multiple tet genes were commonly found among tetracycline resistant S. typhimurium isolates from various sources. The resulting tet gene patterns allowed further discrimination of strains which were otherwise indistinguishable by their phage type, ribotype and origin. Thus, the analysis of tet gene patterns might represent an additional tool for the differentiation of S. typhimurium isolates.

Animals↗

Familial partial monosomy 7 and myelodysplasia: different parental origin of the monosomy 7 suggests action of a mutator gene.

Two sisters are reported, both with a myelodysplastic syndrome (MDS) associated with partial monosomy 7. A trisomy 8 was also present in one of them, who later developed an acute myeloid leukemia (AML) of the M0 FAB-type and died, whereas the other died with no evolution into AML. Besides FISH studies, microsatellite analysis was performed on both sisters to gather information on the parental origin of the chromosome 7 involved in partial monosomy and of the extra chromosome 8. The chromosomes 7 involved were of different parental origin in the two sisters, thus confirming that familial monosomy 7 is not explained by a germ-line mutation of a putative tumor-suppressor gene. Similar results were obtained in two other families out of the 12 reported in the literature. Noteworthy is the association with a mendelian disease in 3 out of 12 monosomy 7 families, which suggest that a mutator gene, capable of inducing both karyotype instability and a mendelian disorder, might act to induce chromosome 7 anomalies in the marrow. We postulate that, in fact, an inherited mutation in any of a group of mutator genes causes familial monosomy 7 also in the absence of a recognized mendelian disease, and that marrow chromosome 7 anomalies, in turn, lead to MDS/AML.

Adult↗

17q21-qter trisomy is an indicator of poor prognosis in acute myelogenous leukemia.

A reciprocal translocation (9;11) is often found in acute myeloid leukemia (AML), mostly of the M5a type. We report a case of a child with AML, in whom t(9;11) was observed at diagnosis as the sole structural abnormality, together with trisomies 19 and 21. The diagnosis was AML evolving from a myelodysplastic syndrome (MDS), and the blast morphology was undifferentiated. Chemotherapy failed to induce morphological remission and the patient's condition soon worsened. A subclone appeared and expanded during the course of the disease, with an additional unbalanced translocation (1;17) leading to trisomy of the long arm of chromosome 17 (17q). The data available from the literature on acquired anomalies involving 17q and our observation led us to postulate a specific link between the gain of 17q and complete chemoresistance.

Acute Disease↗

Meiotic origin of trisomy in neoplasms: evidence in a case of erythroleukaemia.

Trisomic cells in neoplasms may represent abnormal clones originated from a tissue-confined mosaicism, and arise therefore by a meiotic error. We report on a 16-month-old child with erythroleukaemia (AML-M6), whose marrow karyotype at onset was 48,XX,del(13)(q12q14),del(14)(q22q32),+21,+21. The parental origin of the supernumerary chromosomes 21 was investigated by comparing 10 polymorphic loci scattered along the whole chromosome on the patient's marrow and her parents' leukocytes. Three loci were informative for the presence of three alleles, two of which were of maternal origin; two further loci showed a maternal allele of higher intensity. Lymphocytes and skin fibroblasts showed a normal karyotype, and molecular analysis on leukocytes at remission, buccal smear and urinary sediment cells consistently showed only one maternal allele, whereas neonatal blood from Guthrie spot showed two maternal alleles as in the marrow. An accurate clinical re-evaluation confirmed a normal phenotype. Our results indicate that tetrasomy 21 arose from a marrow clone with trisomy 21 of meiotic origin. To the best of our knowledge, this is the first evidence that supernumerary chromosomes in neoplastic clones may in fact be present due to a meiotic error. This demonstrates that a tissue-confined constitutional mosaicism for a trisomy may indeed represent the first event in multistep carcinogenesis.

Alleles↗

Full cytogenetic characterization of a new neuroblastoma cell line with a complex 17q translocation.

Recent studies have shown that structural abnormalities of chromosome 17 resulting in gain of material are the most frequent genetic changes in neuroblastoma. We have established a new neuroblastoma cell line from a patient whose disease had evolved from stage 4s to 4, without evidence of deletion of the short arm of chromosome 1 and MYCN amplification, which are considered the most typical genetic indicators of aggressive disease. The cytogenetic study allowed a full characterization of the chromosome changes, and revealed a complex translocation of chromosome 17 leading to a derivative marker which may be described as follows: der(11)t(11;17)(p15;q12)t(11;17) (q22;q12). This resulted in a gain of part of the long arms of chromosome 17, which was recently associated with poor prognosis.

Animals↗

Isochromosome (7)(q10) in Shwachman syndrome without MDS/AML and role of chromosome 7 anomalies in myeloproliferative disorders.

Shwachman syndrome (SS) is an autosomal recessive disorder in which bone marrow dysfunction is observed, with development of myelodysplastic syndromes (MDS) and acute myeloid leukemias (AML) in up to one third of the cases. Inconclusive data are available as to increased chromosome breakage in SS, while chromosome 7 anomalies, and often an isochromosome (7)(q10), are frequent in cases with MDS/AML. We report on the consistent presence of an i(7)(q10) in the bone marrow and blood lymphocytes in one of two sisters affected with SS without any clinical or cytological signs of MDS/AML. Thus, this patient was either a case of constitutional mosaicism for the i(7)(q10), or this had to be acquired in a nondysplastic and non-neoplastic marrow clone. DNA polymorphism analysis demonstrated the paternal origin of the i(7q). We postulate that the SS mutation acts as a mutator gene, and causes karyotype instability; abnormal clones would thus arise in the marrow, and chromosome 7 anomalies, i(7q) in particular, will in turn lead to MDS/AML. If this interpretation is correct, it would be also an indication to consider chromosome 7 anomalies in general, out of SS, as primary changes in MDS/AML pathogenesis.

Bone Marrow Diseases↗

Ph-positive CML in blastic phase with monosomy 7 in a Down syndrome patient. Monitoring by interphase cytogenetics and demonstration of maternal allelic loss.

We report a case of Ph-positive chronic myelocytic leukemia in blastic phase in an 11-year-old boy with Down syndrome. Monosomy 7 was the only additional chromosomal anomaly in the blastic clone. Fluorescence in situ hybridization analysis on interphase nuclei with a centromeric probe specific to chromosome 7 proved to be efficient in disease monitoring, and showed, together with the results of chromosome analysis on metaphases, that B-lymphocytes at the origin of an EBV-established line were not part of the leukemic clone. The study of DNA polymorphisms showed that the origin of the constitutional trisomy 21 was a maternal anaphase I nondisjunction, that the chromosome 7 lost in the blastic marrow clone was the maternal one, and led us to postulate that the mother's chromosomes are prone to impairment of normal disjunction. The study of allelic losses of chromosome 7 loci proved to be a further possibility for disease monitoring.

Adult↗

Constitutional trisomy 8 as first mutation in multistep carcinogenesis: clinical, cytogenetic, and molecular data on three cases.

Three patients, with constitutional trisomy 8 mosaicism (CT8M), who developed a malignancy are reported. The diagnoses were refractory anaemia, acute lymphoblastic leukaemia, and idiopathic myelofibrosis. In the child with acute leukaemia, the CT8M was diagnosed at birth due to severe dysmorphisms and malformations; the other two patients showed a milder phenotype, and the CT8M was diagnosed only after the finding of trisomy 8 in neoplastic cells. The review of eight similar, previously reported cases and the clinical, cytogenetic, and molecular studies performed in our patients led us to make the following observations: (I) CT8M predisposes to neoplasms, preferentially to myelo- or lymphoproliferative diseases; (2) a gene dosage effect for glutathione reductase in red blood cells was seen in two of our patients; (3) the wide phenotypic variation of CT8M was confirmed: trisomy 8 in neoplastic cells of phenotypically near-normal cases may be misinterpreted as acquired; and (4) molecular studies suggested a postzygotic origin of the trisomy in our three cases, with the supernumerary chromosome being of paternal origin in one case and of maternal origin in the other two. We postulate that the trisomy 8 in neoplasms may often occur by mitotic nondisjunction in an early embryonic multipotent cell and that what is usually interpreted as an acquired trisomy 8 may in fact be CT8M. The constitutional trisomy 8 would act as a pathogenetically important first mutation in multistep carcinogenesis. Whenever trisomy 8 is found in malignancies, the patient should be reevaluated clinically to exclude CT8M, and CT8M patients should be monitored for the possible development of malignancies.

Anemia, Refractory↗

Graft-versus-leukemia effects after allogeneic bone marrow transplantation are active also in the presence of clones with chromosomal anomalies in addition to the Ph chromosome.

Two male patients with Philadelphia-chromosome (Ph+) chronic myelogenous leukemia (CML) underwent allogeneic bone marrow transplantation (ABMT) in the first chronic phase after busulfan treatment. In both cases, the donor was a sister, and engrafting was demonstrated by chromosome analyses which showed only donor cells in the BM. Cytogenetic relapse occurred 29 and 30 months after ABMT, respectively, when host cells reappeared: in both cases, the Ph and additional anomalies typical of the blastic phase of CML were evident. We then monitored the chromosome picture for 52 and 39 months, respectively: no striking evolution occurred, and cells with the Ph and additional anomalies persisted together with donor cells, which were a minority in the first patient and a great majority in the second throughout the observation period. A clinical relapse was observed in the first patient, but the disease never progressed to a blastic phase, whereas the second patient has not relapsed 7 years after ABMT. We reviewed data from the literature on cytogenetic relapse after ABMT in CML without clinical relapse, especially the 12 patients in whom cytogenetic relapse included chromosome anomalies in addition to the Ph, as in our patients. We suggest that graft-versus-leukemia (GVL) reactions in such patients are able to arrest progression of the leukemic blastic clone and prevent a possible relapse in blastic phase.

Bone Marrow Transplantation↗

Clinical, cytogenetic and immunological aspects in 4 cases resembling ataxia telangiectasia.

Four cases resembling ataxia telangiectasia, all characterized by the absence of telangiectasias, are presented. Two are sisters while the other 2 are sporadic cases. The 2 sisters, aged 14 and 12 years, present a progressive neurological disease similar to that characterizing the Louis-Bar syndrome. The clinical picture in 1 of the sporadic cases, a girl aged 13 years, differs from the typical ataxia telangiectasia in having bilateral pyramidal signs in the lower limbs. The last case, a girl aged 8 years, presents an atypical clinical pattern characterized by a severe mental retardation, quite modest cerebellar signs and absence of involuntary movements. The results of the immunological and cytogenetic investigations are presented and discussed.

Adolescent↗

Heparin inhibits A431 cell growth independently of serum and EGF mitogenic signalling.

In several cell types heparin exerts an antiproliferative action; here we report that heparin inhibited the growth of human epidermoid carcinoma A431 cells. Heparin binding to the cell surface was necessary for growth inhibition; binding was influenced by the molecular weight of heparin. Inhibition of A431 cell proliferation was evident in the presence and in the absence of serum, thus indicating that heparin did not act by binding and 'subtracting' nutrients or other serum factors. In confluent A431 cells, EGF induced DNA synthesis, but heparin did not inhibit this effect; consistently, it did not affect inositol lipid turnover triggered by EGF or bradykinin.

Bradykinin↗