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D Belletti

Publications and source records attributed to D Belletti.

14 recordsLinked to original sources
PubMed2000

QED v 1.0: a software package for quantitative electron diffraction data treatment.

A new software package for quantitative electron diffraction data treatment of unknown structures is described. No "a priori" information is required by the package which is able to perform in successive steps the 2-D indexing of digitised diffraction patterns, the extraction of the intensity of the collected reflections and the 3-D indexing of all recorded patterns, giving as results the lattice parameters of the investigated structure and a series of data files (one for each diffraction pattern) containing the measured intensities and the relative e.s.d.s of the 3-D indexed reflections. The software package is mainly conceived for the treatment of diffraction patterns taken with a Gatan CCD Slow-Scan Camera, but it can also deal with generic digitised plates. The program is designed to extract intensity data suitable for structure solution techniques in electron crystallography. The integration routine is optimised for a correct background evaluation, a necessary condition to deal with weak spots of irregular shape and an intensity just above the background.

Algorithms↗
PubMed1997

Immunohematological study in newborn infants with erythroblastosis fetalis transfused in utero.

The present study reports immunohematological data (anti-erythrocyte titer, anti-erythrocyte functional activity, percentage of sensitized erythrocytes) in 11 patients with erythroblastosis fetalis transfused in utero (IUTd). At birth it was possible to define two groups of newborns: one with low (group 1) and one with high (group 2) percentage of circulating sensitized erythrocytes, respectively. The presence of a low rate of sensitized red cells at birth in IUTd infants did not reduce the number of exchange transfusions required postnatally. On the contrary, babies of this group were affected by a more severe disease as shown by higher anti-erythrocyte maternal titer, higher anti-erythrocyte functional activity and a higher degree of fetal hemolysis. The persistence of hemolysis after birth, in spite of the absence of sensitized circulating erythrocytes, may be due to intramedullary hemolysis.

Blood Transfusion, Intrauterine↗
PubMed1995

Detection of platelet-associated antibodies by flow cytometry in hematological autoimmune disorders.

We describe our experience in the evaluation of platelet-associated immunoglobulins (PAIg) by flow cytometry in comparison to solid-phase assay in patients affected by idiopathic thrombocytopenic purpura and by Evans syndrome. Results show that the analysis of PAIg by flow cytometry is easy and reliable and correlates well with data obtained by the solid-phase technique. In addition, flow cytometry allows the evaluation of samples containing small numbers of platelets (< 20,000/mm3); the analysis is objective, not influenced by personal experience. Moreover, flow cytometry appears simple enough to be performed in a routine laboratory, and data might be retrieved to perform batch analysis. Our results appear to indicate that PAIg flow cytometry might be a sensitive tool for the evaluation of patients with autoimmune thrombocytopenia.

Autoantibodies↗
PubMed1995

Cell adhesion molecules CD11a and CD18 in blood monocytes in old age and the consequences for immunological dysfunction. Preliminary results.

Adhesion molecules, such as leukocyte-function-associated antigen (LFA-1 or CD11a/CD18), intercellular adhesion molecule 1 (ICAM-1 or CD54) and Hermes antigen (HCAM or CD44), have important roles in many adhesive interactions involving cells of the immune system. Since it has been shown that many immunological alterations were present in aged subjects, we studied the expression and density of these molecules on peripheral blood lymphocytes and monocytes from healthy old subjects. A decrease in monocyte subpopulations bearing CD11a/CD18 and an increase in CD11a/CD18 and and CD44 antigen density on lymphocytes and on monocytes, respectively, were observed. These changes might be an event in the mechanism leading to the decreased lymphocyte proliferative response in vitro and to other immunological dysfunctions reported in old subjects.

Aged↗
PubMed1994

Flow cytometry: a tool in immunohematology for D+W (Du) antigen evaluation?

We performed a flow-cytometric analysis of the expression of D antigen in D+W samples (previously termed Du). We also analysed a series of D-positive and D-negative (cde phenotype) samples to obtain positive and negative controls, respectively. The evaluation was carried out by immunofluorescence and the intensity of positivity was expressed as mean channel value (MCV) of fluorescence. Results demonstrated that D+W samples have lower expression (less than 1 log) than D-positive cases (p > 0.001, Student t test), while cde samples show the same MCVs as negative controls. Moreover, it was also possible to set a grading of D antigen expression and to analyze cases difficult to assess by agglutination only.

Blood Grouping and Crossmatching↗
PubMed1993

Plasmic levels of trace elements and immune functions in the healthy elderly.

Healthy elderly persons were selected according to an admission protocol which included clinical, hematological and biochemical parameters. Plasmic levels of zinc in these subjects were in the normal range, while plasmic copper was higher than that of young controls. The number of circulating lymphocytes and CD3+ cells was decreased; however, the absolute number of CD4+, CD8b, CD8d, CD20+ and CD57+ cells did not differ from that of controls. A decreased lymphocyte response to PHA in serum-free medium cultures was also observed in the healthy elderly persons.

Aging↗
PubMed1992

Synthesis and structure of new bronchospasmolytic agents. I.

The crystal structures of two phenylethanolamines showing bronchospasmolytic activity have been determined at room temperature [293 (2) K]. Crystal data are as follows: 11-morpholinotricyclo[6.3.0.0(2,7)]undeca-2,4,6-trien-l-ol (3), C15H19NO2, M(r) = 245.3, triclinic, P1, a = 10.360 (5), b = 12.169 (5), c = 12.488 (4) A, alpha = 95.14 (10), beta = 108.49 (12), gamma = 114.69 (5) degrees, V = 1311 (2) A3, Z = 4, Dx = 1.243 Mg m-3, Cu K alpha 1 radiation, lambda = 1.540562 A, mu = 0.618 mm-1, F(000) = 528, R = 0.0537 for 3009 observed reflections; 4-morpholino-1,2-benzocyclononen-3-ol monohydrate (5), C17H25NO2.H2O, M(r) = 293.4, monoclinic, P2(1)/c, a = 10.063 (9), b = 19.398 (5), c = 8.670 (5) A, beta = 110.56 (1) degree, V = 1585 (2) A3, Z = 4, Dx = 1.230 Mg m-3, Mo K alpha 1 radiation, lambda = 0.709300 A, mu = 0.0778 mm-1, F(000) = 640, R = 0.0376 for 1407 observed reflections. The stereochemistry of compound (3) is found to be 'all cis', which allows the mechanism of formation of these compounds to be interpreted. The various aspects of the conformations of these molecules are discussed.

Bronchodilator Agents↗
PubMed1992

Absence of HTLV-I/II infection in blood donors with positive and inconclusive HTLV-I/II serology.

The pathogenetic potential and the true extent of human T leukemia/lymphotropic virus type I (HTLV-I) and type II (HTLV-II) infection are unknown. To find out more about HTLV-I/II seroepidemiology and the risks of iatrogenic transmission, we performed a serological study, screening 4086 healthy blood donors. A surprisingly high percentage of serum reactivity to HTLV-I/II antigens was observed by commercial ELISA (2.08%) and immunoblotting (IB) (0.85%) analysis, although none of the samples satisfied the (IB) criteria for positivity based on detection of gag protein p24 and at least one env gene product, either gp46 or gp61/68. To clarify these inconclusive results, we performed polymerase chain reaction (PCR) analysis for HTLV-I and HTLV-II provirus detection in peripheral blood lymphocytes, obtained from individuals with an apparent pattern of seropositivity. The data obtained by PCR failed to reveal evidence of HTLV-I/II provirus integration in peripheral blood cells, ruling out the possibility of a viral infection in these cases, and pinpointing the limitations of both serological methods used. Our observations suggest that serological assays alone are not a reliable tool for blood donor screening of HTLV-I/II infection and raise the important question of interpreting inconclusive results.

Base Sequence↗
PubMed1989

Analysis of natural killer cells in patients with idiopathic autoimmune hemolytic anemia.

A functional and phenotypic analysis of the circulating natural killer (NK) cell population was carried out in 9 patients with idiopathic autoimmune hemolytic anemia (IAHA). The NK-cell activity, assessed by a sensitive method based on the inhibition of target clone growth in plasma semisolid medium, was markedly decreased in all patients as compared with normal controls and was not restored by stimulation of the cells with recombinant alpha interferon (alpha-IFN). Analysis of peripheral blood phenotypic markers showed that cells bearing Leu7 and CD16 antigens numbered in the normal range. These findings suggest that IAHA patients exhibit a functional impairment of the NK compartment.

Anemia, Hemolytic, Autoimmune↗
PubMed1984

Serological screening for the prevention of transfusion-acquired cytomegalovirus infection.

The presence of antibodies against cytomegalovirus (CMV)-induced immediate-early antigens (IEA), early antigens (EA) and late antigens (LA) was sought in 500 healthy blood donors. Antibodies to late antigens were detected in 76% and antibodies to immediate-early and early antigens were detected in 9.6% and 10.2%, respectively. The incidence of antibodies to CMV-induced immediate-early and early antigens increased with age, was higher in females than in males and was related to high values for antibodies against CMV late antigens. Since antibodies to CMV immediate-early and early antigens are significantly associated with active CMV infection, criteria for choosing blood samples unlikely to transmit infective CMV are evaluated.

Adult↗
PubMedDate not supplied

Mixed lymphocyte reactions evaluated by means of bromodeoxyuridine incorporation.

The mixed lymphocyte reactions are usually performed by the uptake of 3H thymidine (3H TdR) in the study of histocompatibility for allogeneic bone marrow transplantation. Bromodeoxyuridine (BrdUrd), an analogue of thymidine, can be used as an alternative marker of proliferation. In this study we compared the evaluation of the proliferative activity of alloreactive lymphocytes in MLR by 3H TdR and BrdUrd incorporation in flow cytometry. The results show that BrdUrd is able to recognize proliferative activity at least 24-48 hours before 3H TdR, and allows discrimination of proliferation of a few cells despite its proximity to the autologous controls. However, the large quantity of cells needed for every combination is presently a disadvantage of the method.

Bromodeoxyuridine↗