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Biomedical subjects

S Guidi

Publications and source records attributed to S Guidi.

At least 37 records · Page 2Linked to original sources
PubMed1998

Evaluation of breast tumour cell contamination in the bone marrow and leukapheresis collections by RT-PCR for cytokeratin-19 mRNA.

There is considerable interest in an autologous transplantation (AT) programme for patients with high-risk breast cancer; however, the issue of the incidence of occult bone marrow (BM) micrometastasis at diagnosis, and the cancer contamination of peripheral blood stem cell (PBSC) collections used for haematological rescue, is still debated. The presence of BM micrometastasis was evaluated in bilateral BM biopsies obtained at diagnosis of 33 patients with stage II/IIIA breast cancer using: (i) a 'nested' reverse transcriptase-polymerase chain reaction (RT-PCR) assay for cytokeratin 19 (K19) mRNA, (ii) histology, and (iii) immunohistochemistry (IHC) analysis with a panel of three monoclonal antibodies. The RT-PCR assay only was used to determine contamination of PBSC collections obtained after priming with recombinant human granulocyte-colony stimulating factor (rhG-CSF). K19 transcripts in one or both BM samples were detected in 48% of patients at diagnosis, with an overall 85% concordance with the results of IHC analysis. On the other hand, 56% of PCR- and IHC-positive BM samples were diagnosed as 'normal' on histological analysis. 57% of patients showed K19 mRNA in at least one PBSC collection; the possibility to have contaminated PBSC collections was significantly higher in patients with K19 positivity in BM at diagnosis. In four patients who had shown K19 positivity in BM and in PBSC collections, immunoselected CD34+ cells used for haematological rescue were K19-negative. There was a trend towards longer relapse free survival (RFS) in patients transplanted with K19-negative PBSC collections as compared to the others. In conclusion, a substantial proportion of patients with high-risk non-metastatic breast cancer present occult BM micrometastasis at diagnosis and also show cancer contamination of PBSC collections used for AT. These might represent a category of patients with poorer prognosis after AT, and possible candidates for more intensive and/or alternative therapeutic regimens, including AT with purged PBSCs.

Adult↗
PubMed1997

A method for the extraction of genomic DNA from human brain tissue fixed and stored in formalin for many years.

We report a method providing access to high molecular weight, polymerase chain reaction (PCR)-amplifiable genomic DNA from brains stored in formalin for many years. It consists mainly of an intensive proteinase K treatment of ground tissue previously embedded in agarose plugs, followed by a washing and an elution step. The method was tested on brains fixed and stored in formalin for up to 46 years. All extracted DNA show an identical pattern of degradation ranging from well-preserved (more than 20 kb) to 400-bp-long fragments. This was demonstrated for DNA extracted from the cerebellums of elderly psychiatric and geriatric patients (of more than 60 years of age), male and female, demented or not, with postmortem delays longer than 1 h and shorter than 1 day. In all these cases PCR amplification of a 838-bp-long beta-actin product was successfully performed when proteinase K treatment was sufficiently effective to generate pure DNA. Thus, high molecular weight, PCR-amplifiable genomic DNA can be extracted from brains stored in formalin for almost half a century.

Aged↗
PubMed1997

Randomized trial comparing netilmicin plus imipenem-cilastatin versus netilmicin plus ceftazidime as empiric therapy for febrile neutropenic bone marrow transplant recipients.

The aim of this study was to compare the clinical and microbiological efficacy of netilmicin plus imipenem-cilastatin (Net + Imi) vs netilmicin plus ceftazidime (Net + Cef) as empiric antimicrobial therapy in bone marrow transplant (BMT) febrile neutropenic patients (pts). Sixty-six pts undergoing BMT for hematological malignancies and solid tumors were randomized to receive Net + Imi or Net + Cef as first-line antibiotic therapy. A lasting return of temperature to normal and complete disappearance of either clinical or cultural signs of infection without any modification of therapy was considered as improvement; the persistence of fever after 72 hours, the addition of a third antibiotic or a protocol change was considered as failure. Sixty-nine episodes were randomized during the course of the trial; bacteriological evidence of infection was obtained in 17 (25%) febrile episodes. Overall outcome based on clinical responses was as follows: 80% of pts on Net + Imi responded compared to 73% of those on Net + Cef. For microbiologically documented infections response rates were 70% in Net + Imi group and 43% in the Net + Cef group (p = ns). Neither septic death nor toxicity were observed. Both empiric regimens were shown to be effective; Net + Imi appeared to be more effective in microbiologically documented infections but there was no statistical significance. In conclusion, both Net + Imi and Net + Cef are active and safe as empirical treatment of febrile episodes in neutropenic BMT pts.

Adolescent↗
PubMed1996

Unrelated donor marrow transplantation: initial experience of the Italian bone marrow transplant group (GITMO).

From 1 September 1988 to 30 September 1993, a search for an unrelated donor (URD) was started for 633 Italian patients. Eighty-five of them (13%) were transplanted. Despite the introduction of more strict criteria for the selection of compatible donors, the percentage of patients who reached transplant increased significantly after December 1992. For patients who started a search before and after January 1993, respectively the probability of transplant by 8 and 16 months from search activation was 4 and 10%, compared to 22 and 37% (P = 0.0001). The average intervals between search activation and graft were 15 and 8 months respectively, for the first and second group (P = 0.0001). Data of 75 consecutive transplants performed up to March 1994 were analyzed. Actuarial 2-year survival was 15% for patients grafted before 1992 and 40% for those grafted after January 1992. In this latter period, survival of patients with malignant and non-malignant disorders was 32 and 67%, respectively. In univariate analysis, patients younger than 16 years (P = 0.01), patients grafted after 1992 (P = 0.01) and patients receiving the marrow from a 6-antigen matched donor (P = 0.01) showed a higher survival probability. Multivariate analysis did not show any difference, probably due to the low number of patients and to short follow-up. The adoption of stricter and more accurate HLA-matching criteria and the consequent reduction of deaths related to acute GVHD were the main reasons for the improvement of survival observed in patients grafted after 1992.

Adolescent↗
PubMed1996

Combination therapy with G-CSF and erythropoietin after autologous bone marrow transplantation for lymphoid malignancies: a randomized trial.

Previous studies have shown that, unlike in patients submitted to allogeneic BMT, administration of recombinant erythropoietin (Epo) after autologous BMT (ABMT) had no significant effect on erythroid recovery and transfusional requirements. On the other hand, it has also been shown that combining Epo with recombinant granulocyte colony-stimulating factor (G-CSF) in patients with the acquired immunodeficiency syndrome (AIDS) and with myelodysplastic syndromes resulted in additive effects on erythropoiesis. To test the effects of combined G-CSF + Epo therapy on erythroid recovery after autologous bone marrow transplantation a pilot randomized, three-arm trial was designed. Thirty patients suffering from lymphoid malignancies submitted to ABMT were randomly assigned to receive G-CSF alone (5 micrograms/kg, from day + 1 up to reaching an ANC > or = 10(9)/1), G-CSF + Epo (150 U/kg, from day +1 to +21), or neither of these (controls). Patients receiving G-CSF + Epo had significantly more reticulocytes on day +21 and reached 30 x 10(9)/1 reticulocytes earlier when compared to both G-CSF and control patients; however, the number of red blood cell (RBC) transfusions was not modified by the addition of Epo to G-CSF, although both groups had significantly fewer units transfused than controls. No effect on platelet recovery or platelet transfusional requirements was observed. Myeloid recovery was comparable in the G-CSF and G-CSF+Epo groups, and significantly accelerated as compared to controls. We conclude that the addition of Epo to G-CSF causes a slight acceleration of erythroid recovery after ABMT, but is not associated with transfusional benefits. Therefore, the present data do not support the use of Epo in association with G-CSF to hasten erythroid recovery after ABMT.

Anemia↗
PubMed1995

Circulating CFU-E during hematopoietic recovery after allogeneic bone marrow transplantation: relationship to erythroid engraftment.

The more mature erythroid progenitor assayable in vitro, the colony-forming unit-erythroid (CFU-E), is normally found in the bone marrow (BM) but is virtually absent from peripheral blood (PB), unlike the more immature progenitor, the burst-forming unit-erythroid (BFU-E). We report on the detection of CFU-E in the PB of six of 18 patients during hematopoietic recovery following allogeneic bone marrow transplantation (BMT); three of six patients with PB CFU-E were under treatment with recombinant human erythropoietin (rhEpo) as well as six of 12 who did not present with PB CFU-E. PB CFU-E were found as early as day 14 following BMT, reached a peak on day 28, and were still detectable on day 60. The presence of PB CFU-E was associated with signs of stimulated erythroid engraftment--an accelerated reticulocyte recovery, an increased number of reticulocytes, higher levels of serum transferrin receptor, and a reduction in transfusional requirements were found in these patients compared to those without PB CFU-E. The numbers of PB and BM BFU-E were similar in the two groups, as well as the numbers of PB and BM CFU-granulocyte/macrophage (CFU-GM) and multipotential CFU (CFU-GEMM); on the other hand, the percentage of BM BFU-E in S phase of the cell cycle was higher in the group of patients with PB CFU-E. While there was no difference between the two groups in serum Epo levels assayed on days 14 and 28 after BMT, patients with PB CFU-E had higher Epo levels in serum samples collected before starting the BMT procedure. These data suggest that the appearance of circulating CFU-E early after BMT is characteristic of a group of patients with an accelerated erythroid engraftment, although the mechanisms leading to the circulation of CFU-E after BMT remain unclear.

Bone Marrow Transplantation↗
PubMed1994

Monitoring of polyomavirus BK viruria in bone marrow transplantation patients by DNA hybridization assay and by polymerase chain reaction: an approach to assess the relationship between BK viruria and hemorrhagic cystitis.

An association between long-lasting hemorrhagic cystitis (HC) in bone marrow transplantation (BMT) patients and viral infections, mostly with reactivation of the human polyomavirus BK (BKV), is suggested by several previous reports. We have carried out a prospective study in 55 (30 allogeneic, 24 autologous, 1 syngeneic) BMT recipients with the aim of evaluating the role of BKV in this frequent complication after BMT. To overcome the well known difficulties in BK virus isolation in cell cultures, a DNA hybridization assay and the polymerase chain reaction (PCR) were used for the detection and monitoring of viral urinary shedding, respectively. The presence of human polyomavirus JC and adenovirus DNA was also sought in urine specimens. BK viruria was demonstrated in 52.7% of patients (in 53.3% allogeneic and in 54.1% autologous BMT), whereas JCV and adenovirus were seldom present. Seven cases of HC (20% in allogeneic and 4% in autologous BMT) occurred and in all cases the clinical event was associated with BKV urinary shedding. This study suggests that BKV infection alone does not invariably lead to HC in BMT patients; for HC to occur the presence of other, at present unidentified, factors seems to be necessary.

Adolescent↗
PubMed1993

Effects of cyclosporin A on erythropoietin production by the human Hep3B hepatoma cell line.

There is evidence that the inadequate erythropoietin (Epo) production observed in patients undergoing allogeneic bone marrow transplantation (BMT) might be ascribed to an inhibitory effect caused by the immunosuppressive drug cyclosporin A (CsA). In this in vitro study, we have evaluated the effects of CsA on the release of Epo in the culture medium by the human Hep3B hepatoma cell line. In cultures incubated with both CsA and the nonimmunosuppressive CsA analog MeAla-6, but not with the CsA-unrelated immunosuppressive agent FK-506, the levels of Epo in the medium were significantly reduced in comparison with controls, at concentrations (0.01 to 1.6 mumol/L) not affecting total protein synthetic rate nor the constitutive secretion of alpha-fetoprotein. Hep3B cells were found to contain a CsA-binding molecule, with an M(r) of 18 Kd, as assessed by high performance liquid chromatography (HPLC) and ligand-blotting analysis. CsA did not affect the expression of the Epo gene, as judged by Northern blot analysis, but caused a significant amount of Epo to remain unsecreted within the cells; almost all (97% of total) of the intracellular Epo was associated with the plasma membrane subcellular fraction. We conclude that: (1) CsA is able to inhibit Epo release in vitro by Hep3B cells, further supporting the hypothesis that the drug might have a role in the inappropriately low Epo levels observed in BMT patients; (2) the inhibitory effect appears to be specific and not caused by a general impairment of protein synthesis and/or secretion; and (3) the reduced Epo levels found in the medium of CsA-treated Hep3B cultures are supposed to be the consequence of an inability of the cells to correctly process Epo molecules for the secretory pathway.

Amino Acid Isomerases↗
PubMed1993

Chemoprophylaxis of bacterial infections in granulocytopenic patients with ciprofloxacin vs ciprofloxacin plus amoxicillin.

Ciprofloxacin was compared to ciprofloxacin plus amoxicillin as antibacterial prophylaxis in 53 evaluable patients with neutropenic episodes, because an oral penicillin may help to decrease the incidence of gram-positive infections. The two groups were randomized and evaluated in a number of febrile episodes, in days at fever/at risk, in mean interval of first febrile episode, in duration of antibiotic therapy and in causative organisms in febrile episodes. In conclusion, no significant difference was observed between the two groups in prevention of gram-positive bacteremias.

Adolescent↗
PubMed1993

Ondansetron versus chlorpromazine for preventing emesis in bone marrow transplant recipients: a double-blind randomized study.

Ondansetron, a selective 5-HT3 antagonist, is known to be effective for preventing emesis induced by cisplatin and other antineoplastic agents. We undertook a randomized double-blind study in a series of bone marrow transplantation (BMT) recipients to assess the antiemetic efficacy and the safety of ondansetron in comparison with chlorpromazine, which was being used at our institution, as the standard antiemetic agent for the conditioning regimen. Forty patients submitted to BMT (21 autologous, 19 allogeneic) were included in the study. Patients were randomly assigned to receive ondansetron (as a loading dose of 8 mg iv one hour before the beginning of the conditioning regimen followed by a continuous infusion of 1 mg per hour for the whole treatment period) or chlorpromazine 60 mg/m2/day given by continuous infusion for the same period (maximum 8 days). Twenty patients were assigned to ondansetron, while 20 were assigned to chlorpromazine. The response rate in terms of antiemetic efficacy and in nausea control was similar between the two treatment groups. On the contrary the two groups differed significantly in regard to side-effects: patients receiving ondansetron experienced significantly less sedation (p = 0.002), the absence of extrapyramidal reactions (p < 0.001) and no need for dose reduction (p < 0.001) as compared with patients treated with chlorpromazine.

Adolescent↗
PubMed1993

The use of erythropoietin in the treatment of post-bone marrow transplantation anemia.

The issue of the role of erythropoietin (Epo) in the erythroid reconstitution after bone marrow transplantation (BMT) has been addressed in several recent studies. A defective Epo production in response to anemia has been shown to occur in patients undergoing allogeneic BMT unlike in most of those subjected to an autologous rescue. The factors involved in the inadequate Epo production in BMT are discussed, with particular attention to the role of the immunosuppressive drug cyclosporin-A, which has been shown to inhibit Epo production in both in vivo and in vitro models. The observation of defective Epo production eventually led to the development of clinical trials of recombinant human Epo (rhEpo) administration in BMT patients; the aims of these studies were to stimulate erythroid engraftment, hence reducing blood transfusion exposure. Although the number of patients studied up to now is relatively small, a benefit from rhEpo administration in terms of accelerated erythroid engraftment seems very likely, and it may also be associated with decreased transfusional needs in most treated patients. However, further studies are needed to better define indications, dosages and schedules of rhEpo in BMT patients.

Anemia↗
PubMed1992

PKRD: a pharmacokinetic program for least-squares and bayesian analysis of repeated-dose pharmacokinetic curves.

A microcomputer program is presented which analyses multiple-dose pharmacokinetic curves using either a least-squares nonlinear analysis or a bayesian fit. The least-squares subroutine is designed to fit retrospective pharmacokinetic curves and can generate the so-called population pharmacokinetic parameters using the Standard Two-Stage method. The bayesian subroutine can instead be used prospectively to individualise the dosage regimen of a patient based on the concentrations measured in the initial phases of the drug treatment. All the pharmacokinetic subroutines of the program use the one-compartment model with either constant-rate intravenous infusion or oral route with zero-order absorption. The program was tested in a series of ten bone marrow transplantation patients treated with cyclosporine. The least-squares estimates of the one-compartment parameters, calculated by the program, were compared with those generated by the SIMKIN program.

Adolescent↗
PubMed1992

Aztreonam versus colistin-neomycin for selective decontamination of the digestive tract in patients undergoing bone marrow transplantation: a randomized study.

Aztreonam (Az), a minimally absorbable monobactam antibiotic, was compared to colistin plus neomycin (CN), for intestinal decontamination during Bone Marrow Transplantation (BMT) in a controlled study. Thirty-four consecutive patients were randomized in two groups and evaluated for number of febrile episodes, days of fever, fecal cultures and clinical symptoms related to infections or colonizations. No significant differences were observed suggesting that Az is at least as effective as the CN regimen and may be considered as an alternative approach for intestinal decontamination in BMT patients.

Aztreonam↗
PubMed1992

Stimulation of erythroid engraftment by recombinant human erythropoietin in ABO-compatible, HLA-identical, allogeneic bone marrow transplant patients.

Recombinant human erythropoietin (rhEpo) was given i.v. at a dose of 50 U/kg/tid to eight patients undergoing an HLA-matched, ABO-compatible bone marrow transplantation (BMT), from day +1 up to day +30. Compared to the data recorded in 13 similar BMT patients who had not received the hormone, the administration of rhEpo resulted in a faster erythroid engraftment: in fact, the time required to reach a stable hematocrit value greater than or equal to 35% decreased from 123.0 to 58.0 days after BMT. Moreover, the number of blood reticulocytes on day +21 was about fourfold greater in the rhEpo group than in the controls, while the number of the most immature, high RNA content reticulocytes (HFR), as determined by a flow cytometric technique, was more than sixfold greater; finally, the recovery time of both total and HFR reticulocytes was significantly reduced by rhEpo. The stimulation of erythroid progenitors also resulted in a reduction in red blood cell (RBC) transfusion requirements: the number of RBC units delivered in the first 30 days following BMT decreased from 8.1 in the controls to 4.0, while the total number of RBC units before transfusion independence was about threefold lower than in the control. Finally, the time of transfusion dependence was significantly shortened by rhEpo. No clinically significant adverse effect directly attributable to rhEpo was recorded. These data suggest that the administration of rhEpo may be beneficial in hastening erythroid engraftment, and possibly in reducing RBC transfusion requirements following BMT.

ABO Blood-Group System↗
PubMed1991

Impaired erythropoietin production in mice treated with cyclosporin A.

Because recent data indicate that erythropoietin (Epo) production is defective in allogeneic bone marrow transplant (BMT) patients, we investigated the role of the immunosuppressant, nephrotoxic, agent cyclosporin A (CsA) on renal Epo production using an animal model. Mice were injected with 1.0 to 40.0 mg/kg/d CsA for 15 days. Thereafter, circulating Epo levels were evaluated in both intact animals and in mice made anemic with phenylhydrazine (PHZ). Serum Epo levels measured in CsA-treated animals were then compared with the predicted levels, which had been calculated in a reference population of normal, either intact or anemic, mice. In CsA-treated, intact animals both hematocrit and serum Epo levels were not significantly different from controls. However, serum Epo levels in CsA-treated, anemic mice were significantly lower than those expected in a control population of untreated, anemic mice with similar degrees of anemia. No significant increase in serum creatinine was recorded even at the highest doses of CsA used, nor were we able to document signs of renal toxicity by histologic examination of the kidneys. Therefore, therapeutical doses of CsA appear to affect the production of Epo under conditions in which the demand of the hormone is increased, as in response to anemia. We suggest that a subclinical kidney toxicity produced by CsA might have a role in the pathogenesis of the impaired Epo production observed in BMT patients, and may contribute to a delayed erythroid engraftment in at least some BMT patients.

Anemia↗
PubMed1991

[Minor donor of bone marrow graft: medico-legal aspects].

Bone marrow transplantation can provide long-term disease-free survival when used as therapy for a variety of lethal disorders. Authors discuss about the underage donor consent and review the literature. In conclusion they consider that Bone Marrow donation is too important to leave its decision only to parents; they suggest to institute professional committees that consider donor will and verify on which basis he expresses his consent.

Adolescent↗