PubMed Health⌕ Search

Biomedical subjects

S Rossini

Publications and source records attributed to S Rossini.

At least 19 recordsLinked to original sources
PubMed2005

Amotosalen photochemical inactivation of severe acute respiratory syndrome coronavirus in human platelet concentrates.

A novel human coronavirus causing severe acute respiratory syndrome (SARS) emerged in epidemic form in early 2003 in China and spread worldwide in a few months. Every newly emerging human pathogen is of concern for the safety of the blood supply during and after an epidemic crisis. For this purpose, we have evaluated the inactivation of SARS-coronavirus (CoV) in platelet concentrates using an approved pathogen inactivation device, the INTERCEPT Blood System. Apheresis platelet concentrates (APCs) were inoculated with approximately 10(6) pfu mL(-1) of either Urbani or HSR1 isolates of SARS-CoV. The inoculated units were mixed with 150 microm amotosalen and illuminated with 3 J cm(-2) UV-A light. The viral titres were determined by plaque formation in Vero E6 cells. Mixing SARS-CoV with APC in the absence of any treatment decreased viral infectivity by approximately 0.5-1 log10. Following photochemical treatment, SARS-CoV was consistently inactivated to the limit of detection in seven independent APC units. No infectious virus was detected after treatment when up to one-third of the APC unit was assayed, demonstrating a mean log10-reduction of >6.2. Potent inactivation of SARS-CoV therefore extends the capability of the INTERCEPT Blood System in inactivating a broad spectrum of human pathogens including recently emerging respiratory viruses.

Blood Platelets↗
PubMed2004

Rapid detection of all HLA-B*27 alleles (B*2701-B*2725) by group-specific polymerase chain reaction.

Human leucocyte antigen-B*27 is strongly associated with a number of rheumatic diseases, including ankylosing spondylitis and reactive arthritis. Targeted detection of the B*27 group by molecular methods is hampered by the extreme heterogeneity of the serological B*27 group. Here, we describe a simple, rapid sequence-specific primer-based method for detection of all 28 B*27 alleles defined to date. The method involves an initial screening with two sequence-specific polymerase chain reactions (PCRs), which has to be followed by two additional PCR amplifications in samples carrying a few rare subtypes of B*27, B*4202 or B*7301. The described protocol should be useful for laboratories involved in diagnostics and research of rheumatoid diseases.

Alleles↗
PubMed2000

Acquisition of intact allogeneic human leukocyte antigen molecules by human dendritic cells.

In an attempt to transduce monocyte-derived dendritic cells (DCs) by a retroviral vector coding for a cell surface marker, we were confronted by the observation of high transfer of the surface molecule in the absence of vector proviral DNA in the treated cells. Indeed, DCs acquired the surface marker by a mechanism independent of the vector machinery, requiring cell-to-cell contact and involving transfer of lipids and a variety of intact membrane proteins. Most important, this property of DCs also includes acquisition of foreign human leukocyte antigen (HLA) molecules. Consequently, DCs become immunological hybrids as they display their own and foreign HLA molecules. The newly acquired HLA is fully functional because it allows recognition by allo-specific T lymphocytes and the binding and presentation of antigen peptides.

Cell Communication↗
PubMed1997

HSV-TK gene transfer into donor lymphocytes for control of allogeneic graft-versus-leukemia.

In allogeneic bone marrow transplantation (allo-BMT), donor lymphocytes play a central therapeutic role in both graft-versus-leukemia (GvL) and immune reconstitution. However, their use is limited by the risk of severe graft-versus-host disease (GvHD). Eight patients who relapsed or developed Epstein-Barr virus-induced lymphoma after T cell-depleted BMT were then treated with donor lymphocytes transduced with the herpes simplex virus thymidine kinase (HSV-TK) suicide gene. The transduced lymphocytes survived for up to 12 months, resulting in antitumor activity in five patients. Three patients developed GvHD, which could be effectively controlled by ganciclovir-induced elimination of the transduced cells. These data show that genetic manipulation of donor lymphocytes may increase the efficacy and safety of allo-BMT and expand its application to a larger number of patients.

Bone Marrow Transplantation↗
PubMed1994

Peripheral blood lymphocytes as target cells of retroviral vector-mediated gene transfer.

Peripheral blood lymphocytes (PBLs) are key target cells for gene therapy of a number of inherited and acquired blood disorders. We have systematically compared four retroviral vectors, designed according to different strategies, for their efficiency in transfer and expression in human PBLs of the same reporter gene. The receptor gene used in the study codes for the human low-affinity nerve growth factor receptor (LNGFR), and is not expressed on the majority of human hematopoietic cells, thus allowing quantitative analysis of the transduced gene expression by immunofluorescence, with single cell resolution. Peripheral blood mononuclear cells (PBMCs), as well as human hematopoietic cell lines of myeloid and lymphoid origin, were transduced with the four vectors and analyzed for efficiency of gene transfer, integration and stability of vector proviruses, and LNGFR expression at both RNA and protein level. Fluorescence-activated cell sorter analysis of coexpression of LNGFR and lineage-specific cell surface markers was performed in transduced cell lines, PBLs, and T-cell clones to study gene expression on specific cell subpopulations. Although crucial differences were observed among different constructs, all retroviral vectors could transduce, under appropriate infection conditions, T-cell populations representative of the normal immune repertoire. Gene transfer and expression could be demonstrated also in circulating progenitors of mature T cells. Expression of the transduced gene was heterogeneous among cell populations infected with the different vectors, with optimal results obtained by two of the four constructs. Finally, we have devised a simple protocol based on vector-mediated gene transfer and positive immunoselection of the transduced cells that produces virtually 100% gene-modified cells. This may represent a crucial improvement in the way of designing efficacious protocols involving the use of gene-modified T lymphocytes in clinical studies.

Cell Line↗
PubMed1993

Mitomycin C, 5fluorouracil and folinic acid in combination with alpha 2b interferon for advanced colorectal cancer.

AIMS AND BACKGROUND: This study was conducted to investigate the activity and toxicity of 5fluorouracil folinic acid+mitomycin C combined with alpha 2b interferon in advanced colorectal cancer based upon recent studies suggesting a possible biochemical modulation of 5fluorouracil by interferon. PATIENTS AND METHODS: Between June 1990 and April 1991 25 previously untreated patients with advanced colorectal carcinoma were treated with mitomycin C 10 mg/m2 iv bolus on day 1, 5fluorouracil 375 mg/m2 on days 1 to 4 and folinic acid 200 mg/m2 on days 1 to 4 every 4 weeks, combined with alpha 2b interferon 3 million U day continuously. RESPONSE: Of the 25 patients entered into the study, 20 were evaluable for response as 5 patients withdrew due to toxicity (grade 3-4 thrombocytopenia in 4 cases and fatigue in 1). No complete response was recorded, 6 patients had partial remission (30%; 95% confidence interval, 10% to 50%), 4 experienced no change and 10 showed progressive disease. The toxicity of this regimen was significant, particularly myelosuppression. CONCLUSIONS: This combination showed a significant toxicity and low response rate compared with other 5fluorouracil based regimens in advanced colorectal cancer.

Aged↗
PubMed1993

Expression and modulation of a mononuclear phagocyte differentiation antigen (PAM-1) during in vitro maturation of peripheral blood monocytes.

Human macrophages obtained by in vitro maturation of peripheral blood monocytes express a surface antigen, PAM-1, recognized by a monoclonal antibody and typical of pulmonary alveolar and tissue macrophages. PAM-1, undetectable in freshly isolated peripheral blood monocytes, was expressed in monocyte-derived macrophages after 3 days of in vitro adherent culture and was maximal after 14-15 days (50%-60% of positive cells). Similar levels of PAM-1 positivity were observed in non-adherent monocyte-derived macrophages suggesting that cell adhesion was not a critical requisite for the expression of this antigen. Bacterial lipopolysaccharide and a monocyte chemotactic protein preparation respectively suppressed and upregulated PAM-1 expression in monocyte-derived macrophages. In contrast, interferon-gamma, although enhancing the levels of class II HLA-DR antigen in monocyte-derived macrophages, did not influence the kinetics of appearance and the levels of PAM-1 in these cells. Thus, expression of PAM-1, which is restricted to certain stages of the monocyte-macrophage differentiation pathway, is also differentially modulated by activation signals, which can be present in the micro-environment of inflammed tissues.

Antigens, Differentiation↗
PubMed1993

Transfer of the ADA gene into bone marrow cells and peripheral blood lymphocytes for the treatment of patients affected by ADA-deficient SCID.

Severe combined immunodeficiency (SCID) caused by deficiency of the enzyme adenosine deaminase (ADA) is the first genetic disorder considered for human somatic cell gene therapy. ADA-SCID patients can be cured by HLA-matched sibling donor bone marrow transplantation. Alternative transplantation strategies as well as enzyme replacement are being tested in those patients who do not have a suitable matched sibling donor. Some ADA-SCID patients may not be candidates for cytoablation due to infectious damage to the lung or liver, or may have a milder phenotype that does not justify the risks associated with haploidentical bone marrow transplantation. Replacement therapy with PEG-ADA has resulted in improvement in growth, a variable increase in the number of peripheral blood lymphocytes, and a decrease in the incidence of severe infections. Another approach to the treatment of severe genetic diseases is now represented by somatic cell gene therapy. We and others have conducted experiments in vitro and in vivo that have documented that T-lymphocytes are suitable vehicles for gene transfer. Although the pluripotent stem cell remains the ideal target cell for somatic cell gene therapy of disorders of the hematopoietic system, the use of T-lymphocytes as gene therapy vehicles is specifically indicated for ADA-deficient patients where they represent the affected cells. Furthermore, the selective engraftment of T-cells only, following bone marrow transplantation, has resulted in reconstitution of cellular and humoral immunity. A model for the functional analysis in vivo of the human immune system has been utilized for the preclinical evaluation of this approach.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenosine Deaminase↗
PubMed1992

Transfer of the ADA gene into human ADA-deficient T lymphocytes reconstitutes specific immune functions.

Peripheral blood lymphocytes obtained from a patient affected by adenosine deaminase (ADA) deficiency and severe combined immunodeficiency were infected with a retroviral vector containing two copies of a human ADA minigene, and injected into bg/nu/xid (BNX) immunodeficient mice. Six to 10 weeks after injection, human T cells were cloned from the spleens of recipient animals and analyzed for proliferative potential, T-cell surface markers, expression of ADA activity, integration of retroviral sequences, T-cell receptor (TCR) beta gene rearrangement, and specificity of antigen recognition. Efficient gene transfer and expression restored proliferative potential in vitro and long-term survival in vivo. All clonable human T lymphocytes obtained from the spleen of recipient animals had high levels of vector-derived ADA enzyme activity and showed predominantly the CD4+ phenotype. Retroviral integrations and TCR-beta gene rearrangements demonstrated the presence of a variety of different clones in the spleens of recipient mice. Furthermore, the combined analyses of vector integration and TCR rearrangement provided evidence that a circulating progenitor cell was transduced by the retroviral vector, giving rise to different and functional TCRs. Evaluation of antigen-specificity demonstrated both alloreactive and foreign antigen specific immune responses. These results suggest that restoration of enzyme activity in human ADA-deficient peripheral blood T cells by retroviral-mediated ADA gene transfer allows in vivo survival and reconstitution of specific immune functions. Therefore, retroviral vector-mediated gene transfer into circulating mononuclear cells could be successful not only in maintaining the metabolic homeostasis, but also for the development of a functional immune repertoire. This is a fundamental prerequisite for the usage of genetically engineered peripheral blood lymphocytes for somatic cell gene therapy of ADA deficiency.

Adenosine Deaminase↗
PubMed1991

An in vivo model of somatic cell gene therapy for human severe combined immunodeficiency.

Deficiency of adenosine deaminase (ADA) results in severe combined immunodeficiency (SCID), a candidate genetic disorder for somatic cell gene therapy. Peripheral blood lymphocytes from patients affected by ADA- SCID were transduced with a retroviral vector for human ADA and injected into immunodeficient mice. Long-term survival of vector-transduced human cells was demonstrated in recipient animals. Expression of vector-derived ADA restored immune functions, as indicated by the presence in reconstituted animals of human immunoglobulin and antigen-specific T cells. Retroviral vector gene transfer, therefore, is necessary and sufficient for development of specific immune functions in vivo and has therapeutic potential to correct this lethal immunodeficiency.

Adenosine Deaminase↗
PubMed1991

Clinical utility of fractionating erythrocytes into "Percoll" density gradients.

Two rapid methods for fractionating the RBC into five or nine layers of increasing density are reported. These procedures have been used to monitor the decline of glucose-6-phosphate dehydrogenase (G6PD) and 6-phosphogluconate dehydrogenase (6PGD) activity during the process of red cell aging in normal subjects and in beta-thal carriers, to study transfused patients with G6PD and pyruvate kinase (PK) deficiency and to test the effects of inositol hexaphosphate (IHP) encapsulation on RBC subpopulations.

Adult↗
PubMed1990

Decrease of CD4+CD45+ T-cells in chronic-progressive multiple sclerosis.

Circulating lymphocyte subpopulations defined by anti-CD45 and other more common T-cell-specific monoclonal antibodies were analysed in 77 patients with multiple sclerosis and 38 healthy controls. A selective decrease of CD4+CD45+ cell percentages and absolute numbers in chronic-progressive patients was found; in 13 out of 26 patients this subpopulation was less than 11% CD4+CD45+ cells. Similarly, the whole CD45+ cell subset, as well as CD45+ cells expressed as percentages of CD4+ cells, were significantly reduced in chronic-progressive multiple sclerosis. CD4+CD45+ cells, commonly termed "inducer of suppression" T-lymphocytes, did not correlate with percentages or numbers of CD8+ cells. It is concluded that suppressor inducer T-cells act on the CD8+ subset function rather than reducing CD8+ cell numbers. Since CD4+CD45+ cells represent an early stage of lymphocyte maturation (naive T-cells), an under-representation of this subpopulation in active multiple sclerosis might reflect an increased conversion of naive cells into memory cells. This concept may be relevant for a better understanding of the disease pathogenesis.

Adult↗
PubMed1988

Impairment of in vitro natural antibacterial activity in HIV-infected patients.

Circulating PBMC of healthy subjects possess an in vitro natural antibacterial (NA) against enteropathogenic bacteria, including Salmonella species. The effector cell of NA activity is a CD: 4+, 8-, Leu-8/TQ-1+ T lymphocyte acting against bacteria via cytophylic IgA in a mechanism similar to antibody-dependent cellular activity. Because AIDS is a profound immunodeficiency caused by HIV involving primarily CD4 lymphocytes and in particular the Leu-8/TQ-1 subset, it was of interest to assess NA activity of HIV+ subjects at various stages of the disease. Results indicate that NA activity against Salmonella typhi and Salmonella paratyphi C is significantly decreased in AIDS as well as in lymphadenopathy syndrome patients. Furthermore, sera containing IgA against salmonellae were not able to arm PBMC from HIV+ patients. The humoral response against S. typhi-LPS was also greatly decreased after HIV infection, in contrast to the known hypergammaglobulinemia seen in these subjects. Defective NA activity might contribute to the increased incidence of salmonellosis observed in AIDS.

AIDS-Related Complex↗