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Biomedical subjects

G Sirchia

Publications and source records attributed to G Sirchia.

At least 109 records · Page 6Linked to original sources
PubMed1995

The BEST Working Party of the International Society of Blood Transfusion: an international effort to improve the quality of blood components.

BACKGROUND: The Biomedical Excellence for Safer Transfusion (BEST) Working Party of the International Society of Blood Transfusion was formed with the aim of improving the quality and safety of blood components. An outline of the aims, working methodology, and results after the first 4 years of activity of the BEST Working Party is presented. RESULTS: Seven studies have been performed, evaluating techniques for counting residual white cells in white cell-reduced red cells, platelet quality control, and cellular harvests in blood components prepared with different methods. Areas of possible interest in the near future include stem cells, platelet crossmatching, and virus inactivation of blood components. An important BEST feature is the sharing of information gathered through collections of large sets of data from routine settings, so as to produce a reliable picture of the "real world." CONCLUSION: Such information could prove useful to those in charge of developing recommendations and guidelines.

Blood Component Transfusion↗
PubMed1995

Transfusion-transmitted human parvovirus B19 infection in a thalassemic patient.

BACKGROUND: Human parvovirus (HPV) B19 infection has been shown to be transmissible by clotting factor concentrates, most often resulting in asymptomatic seroconversion. So far, no case of B19 transmission due to single-donor transfusion has been documented. CASE REPORT: A case of transfusion-transmitted HPV B19 infection in a 22-year-old female thalassemia major patient is described. She presented with an aplastic crisis; this was followed 1 week later by transitory heart failure and acute tricuspid incompetence. The echocardiogram revealed a grade III tricuspid regurgitation and a floating vegetation on the atrial face of the tricuspid lateral leaflet. The tricuspid regurgitation and vegetation spontaneously disappeared within 15 days. Blood cultures for bacteria were repeatedly negative. IgM anti-HPV B19 seroconversion was documented in the acute phase. B19 DNA was detected by polymerase chain reaction and remained detectable up to 4 months after diagnosis. High-titer IgM anti-HPV and B19 DNA were also found in serum samples collected at the time of donation from one of the donors of the blood transfused before the onset of clinical symptoms. CONCLUSION: This case documents the transmission of HPV B19 by the transfusion of 1 red cell unit and the occurrence of possible transient cardiac involvement in this infectious complication.

Adult↗
PubMed1995

Comparative study of different procedures for the collection and banking of umbilical cord blood.

Different procedures for umbilical cord blood (CB) collection, separation, and cryopreservation were compared to evaluate the feasibility of large-scale CB banking for unrelated transplant. CB collection using an open system was associated with a 12.5% rate of bacterial contamination, whereas this rate fell to 3.3% using a closed collection system. When the umbilical cord was clamped within 30 s after delivery, on 378 occasions it was possible to collect 77 +/- 23 ml of CB without risk to mother or infant. Considering that engraftment can be obtained in recipients of 20 x 10(3) CFU-GM/kg, 86% and 28% of CB samples with a volume larger than 50 ml were found to contain a sufficient number of CFU-GM to engraft patients of 20 and 70 kg, respectively. Both Ficoll and gelatin purification procedures were associated with a recovery of 86-92% of CFU-GM, BFU-E, CFU-GEMM, and HPP-CFC, but the gelatin method appears to be more suitable for large-scale CB banking in vials. After cryopreservation, the recovery of clonogenic progenitors was similar for both CB samples stored as whole blood or as mononuclear cells separated using Ficoll or gelatin. In conclusion, large-scale CB banking seems feasible, and CB cell separation could allow storage of a large number of CB samples in a limited liquid nitrogen space.

Blood Banks↗
PubMed1995

The effect of interleukin-12 in ex-vivo expansion of human haemopoietic progenitors.

We evaluated progenitor cell proliferation in cultures supplemented by different cytokine combinations in the presence or absence of IL-12. In cultures of low density cells, cytokine combinations including IL-12 were associated to a greater proliferation (up to 6.7 +/- 2.5 CFU-GM fold expansion). However, in cultures of purified CD34+ cells the more efficient cytokine combination (147 +/- 49 CFU-GM fold expansion) was SCF, IL-3, IL-11 and MIP-1 alpha, and the addition of IL-12 did not further enhance expansion of progenitors. These results indicate that accessory cells, lost in CD34+ cell purification, could be in part responsible for IL-12 effect on progenitor cell proliferation. In CD34+ cell cultures the addition of IL-12 led to CD19 mRNA generation, suggesting that IL-12 acts on haemopoietic cells with both myeloid and lymphoid potential.

Antigens, CD↗
PubMed1995

Cadaver kidney transplantation in the north Italy transplant program in the nineties.

The most relevant changes which have taken place in the NITp in the nineties include the introduction of HLA-DRB1 matching, the extension of both recipient and donor selection criteria, and an increase in donor procurement and consequently, in transplantation activity. Some of the changes in policy resulted from extensive analysis of our previous experience. For the future years, the NITp has set the following priorities: Consolidate the increase of donor procurement activity registered in the past 15 months by educational campaigns for health workers and the public, and organizational measures aimed at strengthening ICUs, nominating transplant coordinators and introducing a system of reimbursement for organs procured. Improve the quality of results in terms of patient rehabilitation and cost-benefit through: continued evaluation of protocols for patient admission on the waiting lists and careful selection of donors; and prospective use of genomic HLA Class II matching and also consider genomic typing for HLA Class I which is almost a reality. Establish a single pool of patients on the waiting list evaluated according to common protocols with the possibility of performing the transplant in each of the authorized centers in turn, respecting the best HLA match and the local use of organs. Finally, standards for donor treatment, organ procurement, histocompatibility testing and transplantation must be established. For this purpose, accreditation programs which have begun to be applied in Europe seem to be the adequate tool.

Adolescent↗
PubMed1994

Photochemical conjugation of mammalian cells to polymeric supports and membranes: a kinetic study.

A commercial polyester acrylate prepolymer, to which a 2:3 wt/wt ratio of tripropyleneglycol diacrylate was added to increase photopolymerization rate, was employed as photochemical conjugating agent, through photografting. 1,2-Diphenyl,2,2-dimethoxyethanone was added as standard photoinitiator (7.0 wt/wt%), together with varying amounts (0.003-4.0 wt/wt%) of some proprietary photocatalytic systems, based on the following photocatalysts: mu-peroxo-bis[N,N'-ethylene-bis(salicylideneiminato)cobalt(I II) (I), vanadium(V) triethoxide (II), and a synergic mixture of vanadium(V) tri-t-butoxide and tri-i-propoxide (III). A homogeneous suspension containing (10 +/- 2) x 10(5) human thyroid follicular cells per milliliter of photochemically reacting medium was photografted, at a surface density of 6.5 +/- 0.7 mg.cm-2 of diacrylate prepolymer mixture, onto polystyrene plates or onto commercial microfiltration and ultrafiltration membranes consisting of nonwoven cellulose tissues with known porosities varying between 5 and 30 microns and in photografted polyester acrylate-based membranes with a cutoff of 50 +/- 5 KD. Bioconjugation yields, as a function of photografting time, were measured gravimetrically and by multiple internal reflection IR spectroscopy. Three series of experiments were performed: 1) measurements of graft yields of the prepolymer, and of the parallel disappearance of double bonds, in the absence of mammalian cells; 2) the same as 1), in the presence of thyroid follicular cells; 3) the same as 2), but with the photoinitiating system formed by the standard photoinitiator alone, with no photocatalyst. Results show that if a suitable photocatalyst is not added, no practical conjugation is possible. An appropriate choice of the photocatalytic system and of its concentration allows reduction of irradiation times (e.g., by a factor of about 2 x 10(4) calculated as the mean lifetime ratio, between the uncatalyzed system and that with 0.1 wt% of [III]), thus minimizing cell inactivation and/or improving responsiveness to the bioassay. From this point of view, photoactivity of (III) is outstanding. The very small, but clearly perceptible, influence of polymeric support on bioconjugation is also commented upon.

Animals↗
PubMed1994

Quality control of red cell filtration at the patient's bedside.

BACKGROUND: Concern has been raised about the quality of white cell (WBC) reduction in blood components when it is performed by filtration at the patient's bedside. Thus, the quality of red cell (RBC) filtration performed at the bedside through two new flatbed WBC-reduction filters was evaluated. STUDY DESIGN AND METHODS: In the laboratory, 25 and 10 RBC units suspended in additive solution were stored for 1 to 2 and 14 to 21 days, respectively, and filtered through each filter. At the end of filtration, an automated complete blood count and a manual WBC count (Nageotte chamber) were determined in two samples collected from 1) a segment clamped at 5 and 25 cm below the filter along the line connecting prefiltration and postfiltration bags and 2) the postfiltration bag. In addition, 10 of the 11 nurses of the hematology outpatient clinic administered to hematologic patients 25 RBC units stored for 1 to 2 days through each type of filter. At the end of transfusion, a segment was collected from the transfusion set and a WBC count was performed as described above. No filter priming or rinsing with saline was done. RESULTS: WBC counts obtained after laboratory filtration in the segments were similar to those obtained from the postfiltration bags and from the segments collected at the bedside in all cases, with the exception of 14- to 21-day-old RBCs filtered in the laboratory through one of the filters, which produced slightly higher WBC counts in the segments than were seen in the postfiltration bags. The difference was not significant. In no case was the count in the postfiltration bag higher than that in the segment. Nurse training was easy, and bedside filtration was associated with no untoward effects. CONCLUSION: The RBC filtration at the patient's bedside can be equal in quality to that performed in the laboratory, at least in such clinical settings as hematology and oncology departments in which blood transfusion is common practice, and if simple training is provided to the nursing staff. Under the conditions of this study, it seems that quality control of RBC bedside filtration is feasible and simple.

Blood Transfusion↗
PubMed1994

Frozen platelet plates for platelet antibody detection and cross-match.

We performed 2 studies aimed at developing a frozen platelet panel suitable for platelet cross-matching. The stability of the most important platelet membrane glycoproteins and the reactivity of antigens of the human platelet antigen (HPA) and of the human leukocyte antigen (HLA) systems were evaluated with the platelet suspension immunofluorescence test (PSIFT) in a panel of platelets frozen in microplates with 6% dimethylsulfoxide. In study No. 1 we evaluated platelet reaction with a broad-spectrum weak anti-HLA and a potent anti-HPA-1a antiserum and the expression of glycoproteins Ib and IIb/IIIa complex on platelet membrane before freezing and after 0.5, 1, 2, 3, 4, 5, 6 and 12 months of storage at -80 degrees C. In study No. 2 we examined platelet reactivity with anti-HPA-1b, -HPA-2a, -HPA-3a, -HLA-A2, -HLA-A3 of platelets stored frozen for 12 months in parallel with fresh platelets from the same donors. Study No. 1 showed that glycoprotein expression was stable and that the weak anti-HLA and the potent anti-HPA-1a antibodies were clearly detected during 12 months at -80 degrees C. Of the 35 paired PSIFT performed in study No. 2 with fresh and frozen/thawed platelets incubated with anti-HPA-1b, -HPA-2a, -HPA-3a, -HLA-A2, -HLA-A3 antisera and AB serum, concordant reactions were obtained in all cases with the exception of 1 case of HLA-A3-positive platelets incubated with anti-HLA-A3 antiserum, that was reactive with frozen/thawed platelets but nonreactive with fresh platelets from the same donor.(ABSTRACT TRUNCATED AT 250 WORDS)

Antigens, Human Platelet↗
PubMed1994

Cord blood plasma-mediated ex vivo expansion of hematopoietic progenitor cells.

Cord blood (CB) plasma has previously been found to augment the replating capacity of CB-derived hematopoietic progenitors. In the present study, we observed a 2.8 +/- 0.3 and a 1.8 +/- 0.2-fold expansion of CFU-GM in cultures of CB cells without growth factors but supplemented by CB plasma or maternal blood (MB) plasma, respectively. In the absence of growth factors, CFU-GM expansion did not occur in CB cell cultures supplemented with fetal calf serum (FCS), peripheral blood (PB) plasma, PB plasma plus concentrations of IL-6 similar to those previously reported in CB plasma and in bone marrow (BM) cell cultures supplemented with FCS, CB, MB or PB plasma. In the presence of stem cell factor (SCF), IL-3 and IL-11, an expansion of CFU-GM was observed in CB and BM cell cultures supplemented by either CB, MB or PB plasma or FCS. Nevertheless, progenitor expansion was significantly superior in CB cell cultures supplemented by CB plasma (8.7 +/- 0.7, 2.4 +/- 0.3 and 2.6 +/- 0.3-fold expansions for CFU-GM, BFU-E and CFU-Mix, respectively). In conclusion, an unknown factor(s) present in CB plasma, probably capable of crossing the placenta, has an effect alone and in the presence of growth factors in supporting ex vivo expansion of CB progenitors.

Adult↗