PubMed Health⌕ Search

Biomedical subjects

C Rumi

Publications and source records attributed to C Rumi.

100 records · Page 6Linked to original sources
PubMed1986

Eosinophil-mediated cellular cytotoxicity induced by zymosan-activated serum.

The aim of the present work was to develop an in vitro model of eosinophil cytotoxicity which mimics numerous in vivo situations characterized by complement activation through the alternative pathway. Our results demonstrate that eosinophilic granulocytes from patients with parasitic diseases and blood eosinophilia were able to damage chicken red blood cells when incubated with zymosan-activated serum (ZAS) as assessed by a 51Cr release assay. The phenomenon was independent of the presence of antibodies directed against the target cells and related to the quantity of ZAS added to the wells. As target cell lysis is totally or partially inhibited by catalase, sodium azide and potassium cyanide, an involvement of toxic oxygen derivatives as cytolytic mediators was suggested.

Azides↗
PubMedDate not supplied

Vernal keratoconjunctivitis: a model of 5q cytokine gene cluster disease.

Clinical studies of vernal keratoconjunctivitis (VKC) patients show that total IgE serum levels are increased even in the absence of IgE antibodies to common allergens. Activated eosinophils are also a constant feature of VKC at both the circulation (cytofluorimetry) and tissue (tear cytology and conjunctival scrapings) levels. Moreover, allergen challenge induces a prolonged inflammatory reaction with a prevalent participation of eosinophils, lymphocytes and possibly basophils. Immunohistochemical studies of VKC biopsies show a multicellular inflammatory infiltrate with prevalence of activated eosinophils, mast cells and CD4 lymphocytes in both epithelium and subepithelium. Mediator studies indicate that eosinophil products (eosinophil peroxidase, eosinophinal cationic protein and eosinophil-derived neurotoxin/eosinophil protein X) are increased in both serum and tears, where tryptase and interleukin (IL)-5 are also detectable in higher amounts than in controls. On the basis of these findings, we postulate that VKC can represent a phenotypic model of up-regulation of the cytokine gene cluster on chromosome 5q which through its products (IL-3, IL-4, IL-5 and granulocyte/macrophage-colony-stimulating factor) regulates Th2 prevalence, IgE production as well as mast cell and eosinophil growth and function in VKC.

Allergens↗
PubMedDate not supplied

Transplantation of autologous peripheral blood progenitor cells: impact of CD34-cell selection on immunological reconstitution.

Peripheral blood progenitor cells (PBPC) represent an ideal source of stem cells for autologous transplantation because of technical advantages and more favourable engraftment kinetics. The reconstituion of a functional immune system occurs earlier in patients transplanted with cytokine-mobilized autologous PBPC compared with bone marrow; because of the greater T-cell content in PBPC products, donor-derived antigen-specific T-cells transferred with the graft might contribute to short-term immunity in transplant recipients. Despite a prompt reconstitution of B- and T-cell numbers, both B- and T-cell function are profoundly impaired for a prolonged period of time after PBPC infusion. The positive selection of CD34+ cells might provide effective tumor cell purging without compromising hematopoietic recovery in patients with acute leukemia, multiple myeloma, breast cancer and non-Hodgkin's lymphoma, whose autografts have been reported to contain malignant cells which might promote disease relapse. However, the incidence of viral infections in the early posttransplant period might be increased after CD34-selected compared with unmanipulated PBPC transplants, as a result of the lack of accessory and immune cells in the graft. The purpose of this review is to provide an update on immunological reconstitution after transplantation of autologous PBPC; in particular, emphasis will be placed on the mechanisms of immune dysfunction after the infusion of unmanipulated and CD34-selected autografts.

Antigens, CD34↗
PubMedDate not supplied

[Allergy to beta-lactam antibiotics in childhood. Diagnostic problems].

This study reports about 126 children with an age ranging from 12 months to 12 years having RA to beta-lactamase. More children with an age ranging from 7-12 years (59.5%), and more male (65.9%) than female subjects were studied. 76 patients (60.3%) showed a familial anamnesis of allergic diseases or similar diseases and a personal anamnesis of allergic diseases (45.2%). Among the RA responsible substances the more frequent were semisynthetic penicillin (44.6%) followed by cephalosporin and penicillin. Most clinical manifestations (87.3%) were cutaneous reactions and in smaller number of cases it was possible to observe gastroenteric or respiratory reactions. In 121 patients cutaneous tests were undertaken (Prick tests and intradermoreactions), patch tests, employing: PPL, MDM, Penicillin, Ampicillin, Cephaloridine. 5.8% of the studied subjects showed an allergy. Particularly 2.4% showed a "early" positivity. RAST was carried out in 92 patients and 3 of them showed a positive result (3.2%). This study stresses the opportunity to carry out allergologic tests within 6 months since the beginning of RA. In fact especially in children this test result can soon become negative. Furthermore the reduced percentage of positive allergologic tests can be due to the inclusion in other studies of patients with "coincidental reactions". A certain number of RA can be caused by additive to "per os" products. Finally it will be possible to use "tests dose" even in selectioned cases. These tests can frequently exclude the etiopathogenetic responsibility of beta-lactamic substances.

Anti-Bacterial Agents↗
PubMedDate not supplied

Interleukin 2 proliferative response by cord blood mononuclear cells of term and preterm neonates.

The results of previous studies on the proliferative response of resting cord blood mononuclear cells (CBMC) of term neonates to human recombinant interleukin 2 (hrIL-2) are contrasting. Some authors have reported a good and others a poor response. In our study we have obtained a significant reactivity, compared with the response of resting peripheral blood mononuclear cells (PBMC) of adult subjects, of resting CBMC to varying quantities of hrIL-2 in the absence of any known mitogenic or antigenic stimuli. Most responding cells was CD3 positive. Both CD4-positive and CD8-positive cells responded. However, we observed a more marked increase of the percentage of the CD4-positive T cells and a clear reduction of the percentage of the CD21-positive cells (B-lymphocytes) testing CBMC rather than PBMC of the adult subjects. The percentage of the NK cells was reduced in both the categories of subjects. Moreover, we have examined the reactivity to hrIL-2 of CBMC of preterm neonates. The results showed that this response is low. The peculiar level and kinetic of CBMC proliferative response to hrIL-2 are discussed.

Adult↗
PubMedDate not supplied

Indicative morphological myelodysplastic alterations of bone marrow in overt AIDS.

In HIV infection, numerous alterations of the hematopoietic system, with frequent cytopenias in peripheral blood and dysplasia of the bone marrow, have been observed. In order to assess the incidence of the myelodysplastic anomalies, 69 bone marrow aspirate smears from 47 patients with group IV HIV infection, as classified by CDC, have been studied. Various degrees of myelodysplastic alterations were found in all cases; however, dysgranulopoiesis was more frequent and more accentuated than other kinds of dyshematopoiesis. Intense vacuolization, especially in the granuloblastic series, was very frequent. It is felt that a bone marrow configuration that is highly indicative of overt AIDS can be sketched. The human immune deficiency virus may be either directly or indirectly responsible for myelodysplastic alterations.

Acquired Immunodeficiency Syndrome↗
PubMedDate not supplied

Lymphocyte subset counting by immunoperoxidase using an automated routine hematologic analyzer.

Using monoclonal antibodies against CD2, CD4, CD8 and CD19 antigens and an automated biotin-avidin immunoperoxidase technique on whole blood samples, we evaluated the technical performance and clinical usefulness of lymphocyte subset counting by the routine hematology analyzer Technicon H*1. Statistical evaluation demonstrated excellent precision and very good correlation with the immunofluorimetric flow cytometer Ortho Spectrum III. Correlation between manual immunofluorescence at the microscope and the H*1 method was much poorer, owing to the high intrinsic imprecision of the manual method. Reference ranges obtained with the H*1 immunoperoxidase method in 44 healthy subjects closely matched those obtained with the Spectrum III. In 46 subjects with or at risk for HIV infection, we found with the H*1 method a significant decrease in CD4+ cells and in the CD4+/CD8+ cell ratio, which was progressively more marked in HIV- negative patients with lymphadenopathic syndrome, AIDS-related complex, and in patients with full-blown AIDS.

Antibodies, Monoclonal↗
PubMedDate not supplied

Telomerase activity in human hematopoietic progenitor cells.

BACKGROUND AND OBJECTIVE: Telomerase is the enzyme that stabilizes and elongates the telomeric ends of chromosomes. It is expressed in germline and malignant cells and absent in most human somatic cells. The selective expression of telomerase has thus been proposed to be a basis for the immortality of germline and malignant cells. Recently, telomerase activity has been observed in human bone marrow (BM) and peripheral blood (PB) samples. The objective of our study was to further characterize the telomerase-expressing population in BM and PB. METHODS: CD34+ cells were isolated from BM and PB, cultured in vitro, and telomerase activity was assessed by the PCR-based TRAP assay. RESULTS: Telomerase activity in human BM and PB could be almost exclusively assigned to the hematopoietic progenitor cell fraction expressing the CD34 antigen. We observed telomerase activity in CD34+ cells from BM and cytokine-mobilized PB. CD34+ cells lacking co-expression of CD33 demonstrated higher levels of telomerase than myeloid committed CD34+/CD33+ cells. In vitro culture of CD34+ cells in the presence of a cocktail of growth factors inducing differentiation resulted in a decrease of telomerase activity. Telomerase activity increased in peripheral blood during cytokine-induced mobilization of hematopoietic progenitor cells. INTERPRETATION AND CONCLUSIONS: Our data demonstrate that at least a portion of the hematopoietic stem/progenitor cell fraction expresses telomerase and downregulates its expression through differentiation.

Antigens, CD34↗