PubMed Health⌕ Search

Biomedical subjects

F Porta

Publications and source records attributed to F Porta.

At least 91 records · Page 5Linked to original sources

Analysis of X-chromosome inactivation and presumptive expression of the Wiskott-Aldrich syndrome (WAS) gene in hematopoietic cell lineages of a thrombocytopenic carrier female of WAS.

We report on a thrombocytopenic female belonging to a pedigree with the Wiskott-Aldrich syndrome (WAS). Restriction fragment length polymorphism (RFLP) analysis with probe M27 beta, closely linked to the WAS gene, demonstrated that she is a carrier of WAS. Both small-sized and normal-sized platelets were present, suggesting that, unlike the vast majority of WAS carriers, she does not manifest nonrandom X-chromosome inactivation in the thrombopoietic cell lineage. Study of X-chromosome inactivation by means of RFLP and methylation analysis demonstrated that the pattern of X-chromosome inactivation was nonrandom in T lymphocytes, but random in granulocytes. While this is the first complete report on the occurrence of thrombocytopenia in a carrier female of WAS as the result of atypical lyonization, it also suggests that expression of the WAS gene occurs at (or extends up to) a later stage than the multipotent stem cell along the hematopoietic differentiation pathway.

Dosage Compensation, Genetic↗

Long term survival after heart transplantation for doxorubicin induced cardiomyopathy.

A 10 year old child developed severe cardiomyopathy after combined, multicycle chemotherapy for Ewing's sarcoma and was treated by heart transplantation with good results. Long term azathioprine and cyclosporin caused only mild impairment of immune function and there were no recurrent infections, local recurrences of the tumour, or distant metastases.

Cardiomyopathy, Dilated↗

Allogeneic bone marrow transplantation in children from other than HLA-identical sibling donor.

Optimal allogeneic bone marrow transplantation (BMT) presupposes the use of a HLA-identical sibling as donor. Unfortunately, only about 30% of patients have an HLA-matched donor, so that the use of alternative donors has been increasingly used. We report an analysis of 13 children transplanted using an HLA-partially matched donor as source of haemopoietic stem cells. They suffered of ALL (3 pts), ANLL (1 pt), SAA (2 pts), Osteopetrosis (1 pt), Wiskott-Aldrich Syndrome (2 pts), Severe Combined Immunodeficiency Disease (2 pts) and Familial Haemophagocitic Lymphohistiocytosis (2 pts). Full engraftment was obtained in all 11 of the patients who survived longer than 14 days and, globally, a moderate incidence of acute GvHD (grade II-IV) was observed in the evaluable patients (3 out of 11 with a percentage of 27%); only a patient of the six survivors more than one hundred days after BMT had severe chronic GvHD (16.6%). Four pts (31%) are actually alive and well (mean follow-up 358 days) with a mean Karnofsky score of 95%. Our data suggest that BMT from HLA-partially matched donors could represent a possible alternative therapeutic strategy in children when a compatible donor is not available. This is especially due to the reduced severity of GvHD in childhood and because of T-cell depleted marrow transplants could obtain more satisfactory results when employed in typical pediatric non-malignant disorders (i.e. immunodeficiencies) rather than in leukemia.

Adolescent↗

Autologous bone marrow transplantation for acute lymphoblastic leukemia: the high dose vincristine study of AIEOP BMT group.

This study was performed in 5 pediatric centers. It considered a group of children affected by acute lymphoblastic leukemia (ALL) treated with ABMT. 56 patients were considered, 35 males and 21 females, with a median age of 11 years. The children were transplanted in 2nd (36) or subsequent (20) complete remission. The mean of 1st remission duration was 32 months. Analysis of the sites of relapse before transplantation showed that 39 patients had bone marrow relapses, 17 patients had CNS and/or testicular isolated relapses only. 32 harvests were purged in vitro by 1 mcgr/ml Vincristine and 30 mcgr/ml Prednisone, 16 by 100 mcgr/ml Mafosfamide, 8 were not cleaned. 29 patients received high dose Vincristine (4 mg/m2), TBI (1200 cGy), Cyclophosphamide (3600 mg/m2) as standard conditioning regimen before transplant. 27 patients received other conditioning treatments with (14) or without (13) TBI. Of the 56 children 25 relapsed from 1 to 42 months after ABMT, 7 toxicity related deaths were registered and 1 death for second tumor was observed. 23 children remained in continuous complete remission from 1 to 49 months after transplantation. The probability of EFS at 4 years was 21%. High dose Vincristine did not statistically improve the EFS, but a trend was observed (44% versus 0%). Vincristine, Asta-Z or none purging did not show any significant effect on EFS (37% vs 32% vs 0%). On the contrary when the EFS was related to the site of relapse, isolated or sistemic, the difference was almost statistically significant (46% vs 18%). The analysis of our results indicates the isolated relapse as good prognostic factor in ABMT for ALL and high dose Vincristine associated to conditioning regimen as worthy of further investigations.

Adolescent↗

Bone marrow transplantation in childhood: a report from the AIEOP-BMT group registry.

A multicenter cooperative group has been activated in Italy in 1986, with the aim of focusing on the following issues: to standardize perspectively the approach to bone marrow transplantation (BMT) in pediatric centers granting the recommendations of the Associazione Italiana di Ematologia e Oncologia Pediatrica (AIEOP); to study effects and toxicity of preparative regimens to BMT; to evaluate the special features of BMT in children, such as clinical management, care and late effects, as peculiar issues of a pediatric setting. Indeed, one of the major aims of the group is to attempt to address in the most appropriate ways, such as in children only and at a nation-wide level, the most crucial questions about the real role of BMT, taking advantage from the fact that most of the children with cancer undergoing BMT in Italy have been treated homogeneously before transplant, i.e. according to AIEOP protocols (70%). Accordingly, specific information were recorded by means of problem oriented forms, aimed to generate a full registry. The registry has been collecting the experiences of 10 pediatric hematology and oncology centers where children eligible for BMT were registered and/or where BMT was performed. This paper was meant both to summarize the 4 years activity of the registry and to analyze what we have learnt so far, as well as what may be suggested to design our future strategies by presently available although retrospective data. It is concluded that the pediatric BMT registry we set up appears useful and of growing interest and potential relevance.

Adolescent↗

European experience of bone-marrow transplantation for severe combined immunodeficiency.

The outcome of bone-marrow transplantations (BMT) carried out between 1968 and March 1, 1989, in 183 patients with severe combined immunodeficiency (SCID) was analysed. Recipients of HLA-identical BMTs (70) had a 76% probability of survival (median follow-up 73 months). Of the 32 treated since 1983, 97% have been cured (median follow-up 41 months). This good prognosis was associated with rapid development of T and B cell function. HLA-non-identical, T-cell-depleted, BMT (n = 100) gave significantly lower survival (52%; median follow-up 47 months). Factors associated with poor prognosis were the presence of a lung infection before BMT, absence of a protected environment, and use of female donors for male recipients. Use of a conditioning regimen significantly increased the frequency of sustained engraftment (86% vs 50% for non-conditioned BMT) and resulted in more frequent engraftment of donor B lymphocytes and myeloid cells. Donor B-cell chimerism was strongly associated with the development of normal B-cell function.

Actuarial Analysis↗

Severe acute encephalopathy following inadvertent intrathecal doxorubicin administration.

In a female with acute lymphoblastic leukemia, inadvertent doxorubicin administration intrathecally caused severe, life-threatening, acute encephalopathy with high-pressure hydrocephalus. Ventriculo-peritoneal shunting led to complete reversal of hydrocephalus with progressive disappearance of the acute encephalopathy.

Antineoplastic Combined Chemotherapy Protocols↗

Mutations in genetic variants of human serum albumin found in Italy.

A long-term electrophoretic survey of genetic variants of serum albumin has identified an alloalbumin in 589 unrelated individuals in Italy. The alloalbumins were classified electrophoretically into 17 types. The number of unrelated carriers for each type varied from 1 for several variants reported here to 103 for albumin B. The structural change in 8 of these types has previously been determined, and the amino acid substitutions in 3 additional types are reported here. Albumin Varese has a substitution, -2 arginine to histidine (-2 Arg----His), the same as that reported for proalbumin Lille; albumin Torino has the substitution 60 Glu----Lys; and albumin Vibo Valentia has the substitution 82 Glu----Lys. The ability to distinguish so many alloalbumin types by electrophoresis at several pH values indicates that similar substitutions at different sites produce variants with different electrophoretic mobilities. Except for chain terminations in two Italian variants, all the mutations thus far determined for alloalbumins are attributable to a single-base change in the structural gene, and there is a preponderance of transitions and purine mutations. Seven alloalbumins for which the structural change has been established have been ascertained only in Italy. Several of these are clustered in specific geographic regions of Italy, which suggests an origin through a founder individual. Other variants that occur worldwide are nonetheless clustered in geographic regions within Italy. In these cases an independent mutation probably occurred at a hypermutable site such as a CpG dinucleotide.

Amino Acid Sequence↗

The molecular defect in a COOH-terminal-modified and shortened mutant of human serum albumin.

Albumin Venezia is a fast migrating genetic variant of human serum albumin which, in heterozygous subjects, represents about 30% of the circulating protein. The molecular defect in this variant was studied in a subject possessing an atypical level of the mutant (80% of the total protein) and in other members of his family. Albumins, isolated from the sera of the propositus and his heterozygous relatives, were treated with CNBr and the resulting fragments analyzed by isoelectric focusing. The peptides were then isolated in a homogeneous form by reverse-phase high performance liquid chromatography and submitted to sequence analysis. The results show that albumin Venezia possesses a shortened polypeptide chain, 578 residues instead of 585, completely variant from residue 572 to the COOH-terminal end: sequence: (see text). This extensive modification may be accounted for by the deletion of exon 14 and translation to the first terminator codon of exon 15, which normally does not code for protein. The absence of a basic COOH-terminal dipeptide in the mature molecule can be explained by the probable action of serum carboxypeptidase N. Additional support for such action comes from examination of the remaining 20% of the total albumin of the propositus, which is found to contain an extra Arg at its COOH terminus, probably due to partial digestion by carboxypeptidase N. The low serum level of the variant in heterozygous subjects suggests that the COOH-terminal end of the molecule is critical for albumin stability.

Amino Acid Sequence↗

Primary rib tumours in children (report of 27 cases with short literature review).

27 cases of primary malignant and benign rib tumours are reported. The most common malignant rib tumour in childhood is Ewing sarcoma (20 cases). Some other rare bone tumours and tumorous conditions (reticulosarcoma, aneurysmal bone cyst, monostotic rib eosinophilic granuloma, osteoid osteoma and lymphangioma) are also described. In the authors' opinion Ewing sarcoma presents with characteristic clinico-radiographic findings in most of the cases. Other monostotic, primary rib tumours and tumorous conditions in childhood--with the exception of exchondroma and enchondroma--rarely show diagnostic radiographic features.

Adolescent↗