Biomedical subjects

R Serafini

Publications and source records attributed to R Serafini.

At least 19 recordsLinked to original sources

PubMed1995

Depolarizing GABA-activated Cl- channels in embryonic rat spinal and olfactory bulb cells.

1. We have compared the electrical properties of the Cl- channels activated by GABA in cells acutely dissociated from embryonic (E) spinal cord (SC) and olfactory bulb (OB) regions at E15 using different configurations of the patch-recording technique. By in situ analysis these cells express GABAA receptor mRNAs encoding a common set of subunits (alpha 2, beta 2, and beta 3). SC cells also express alpha 3, alpha 5 and gamma 2s transcripts. 2. Whole-cell recordings revealed current responses to GABA (0.5 microM to 1 mM) in 242 out of 294 cells. In both SC and OB cells, currents evoked by 2 microM GABA could be potentiated by diazepam (DZP) in a dose-dependent manner with an EC50 of approximately 50 nM in both SC and OB. The maximal effect was approximately 300%. Both SC and OB cells exhibited GABA-activated currents that were only partially sensitive to zinc even at high micromolar concentrations. The effect of DZP and the relatively modest sensitivity to zinc suggest the presence of gamma subunits in both preparations. 3. Spectral analysis of current responses in twenty-six cells showed that power spectra could be fitted by three exponential components (tau 1-3) in the cells of both areas. The tau of the longest-lasting component (tau 3) was significantly different in the cells of the two areas: approximately 50 ms in OB and 80-100 ms in SC. No statistically significant differences in the average inferred unitary conductance between the two cell types could be resolved. 4. Single-channel properties were examined directly using the cell-attached configuration. GABA-activated channels could be recorded in only 89 out of well-sealed 984 patches and most of them exhibited multiple channel activity. The mean open time in the response to 10 microM GABA was significantly shorter in OB cells (12 ms) compared to SC cells (25 ms) while the average conductance values were not significantly different between the two cell types. 5. On average, Cl- channels reversed polarity when the on-cell patch pipette potential was approximately -30 mV. Thus, in these embryonic neurons, micromolar GABA activates Cl- channels, which, when open, effectively depolarize cells by approximately 30 mV. 6. Cl- channels activated by GABA are open longer in embryonic SC cells than in OB cells. This statistically significant difference in native GABAA receptor Cl- channel properties correlates with, and may be related to differences in subunit mRNA expression.

Action Potentials↗

PubMed1995

Very high-dose chemotherapy with autologous peripheral stem cell support in advanced ovarian cancer.

20 patients with stage III-IV ovarian cancer were submitted to induction chemotherapy (ICT) (40 mg/m2 cisplatin, days 1-4; 1.5 g/m2 cyclophosphamide, day 4; every 4 weeks for 2 cycles) followed by intensified CT (100 mg/m2 cisplatin, day 1; 650 mg/m2 etoposide, day 2; 1.8 g/m2 carboplatin by 24 h infusion, day 3). Haematological support consisted of autologous peripheral stem cells (APSC) and bone marrow (ABM) transplant (T) in 16 and 4 patients, respectively. All patients were evaluable for toxicity and 19 for pathological response (PR), one patient dying of systemic mycosis after ABMT. Severe (grade 3-4) non-haematological toxic effects were gastrointestinal (100%), neurological (10%) and hepatic (10%). PR was observed in 84% of patients (complete response 37%, partial response with microscopic residual disease 26%, partial response with macroscopic residual disease 21%). Five year overall survival was 60% and progression-free survival was 51% with 9 patients still disease-free (DFS). APSCT significantly reduced the duration of aplasia compared with ABMT, and toxicity was acceptable in those patients undergoing APSCT. The prolonged DFS in patients showing PCR suggests that this new approach may have a therapeutic impact.

Adenocarcinoma↗

PubMed1995

The low efficacy gamma-aminobutyric acid type A agonist 5-(4-piperidyl)isoxazol-3-ol opens brief Cl- channels in embryonic rat olfactory bulb neurons.

4-PIOL is a structural analog of GABA that has low efficacy at GABAA receptor CI- channels and activates a nondesensitizing CI- conductance in central neurons. We investigated the biophysical mechanisms of its low efficacy in embryonic olfactory bulb neurons, which express a limited number of GABAA receptor subunit transcripts. Spectral analysis of GABA- and 4-PIOL-induced current fluctuations evoked in whole-cell recordings showed that three components with mean durations of approximately 0.7, 5, and 50 msec adequately describe the kinetics of the responses induced by both ligands. The contribution of the longest-lasting component was approximately 60% in the spectra of GABA-evoked responses but < 3% in the spectra of 4-PIOL-evoked responses. This is interpreted as a low incidence of long-lasting bursts in 4-PIOL-evoked responses. No difference was evident between the average inferred unitary conductances for 4-PIOL- and GABA-induced channels. These results at the level of the whole cell were confirmed and extended in outside-out single channel recordings. Taken together, the results indicate that the mechanism responsible for the low efficacy of 4-PIOL is the inability to produce frequent bursts of long duration.

Animals↗

PubMed1994

In vitro and in vivo effects of recombinant human erythropoietin plus recombinant human G-CSF on human haemopoietic progenitor cells.

We tested in vitro the effect of recombinant human erythropoietin (rhEPO) plus recombinant human G-CSF (rhG-CSF) on purified human CD34+ haemopoietic progenitors (HP) and in vivo in patients who had undergone anti-cancer chemotherapy for advanced ovarian cancer. In this preliminary experience we found that, in vitro, rhEPO potentiates the effect of rhG-CSF on HP growth and differentiation toward the granulocyte-macrophage lineage. rhEPO plus rhG-CSF produced in vitro a proliferative stimulus of HP which represents 26% of the maximum stimulation obtained using IL-1, IL-3, IL-6, G-CSF, GM-CSF and stem cell factor in combination. In the patients treated with rhEPO plus rhG-CSF after chemotherapy, we observed a favourable trend for platelet and neutrophil recoveries compared with a control group treated with rhG-CSF alone and a significantly higher haematocrit nadir was observed in the rhEPO plus rhG-CSF series. In the patients treated with rhEPO plus rhG-CSF we observed a significant increase of circulating colony-forming unit granulocyte-macrophage (CFU-GM) and burst forming unit-erythroid (BFU-e) compared with the rhG-CSF series. Our results, in vitro and in vivo, encourage the in vivo use of rhEPO plus rhG-CSF to improve blood cell recoveries of patients who have undergone conventional or high-dose chemotherapy. Moreover, rhEPO plus rhG-CSF was demonstrated to be a good HP mobilising treatment for blood stem cell collection after chemotherapy.

Adult↗

PubMed1994

Low-dose cyclophosphamide in combination with cisplatin or epirubicin plus rhG-CSF allows adequate collection of PBSC for autotransplantation during adjuvant therapy for high-risk cancer.

Six patients with advanced ovarian carcinoma (OvCa), and six patients with stage II or III resectable breast cancer (BrCa) were treated with low-dose CY (LD-CY, 1500 mg/m2) and cisplatin (CDDP) 100 mg/m2 (OvCa) or epirubicin (EPR) 120 mg/m2 (BrCa) plus recombinant human G-CSF (rhG-CSF). Twelve days after chemotherapy, all patients underwent PBSC collection on an outpatient basis. Following the completion of the induction programme, all patients underwent high-dose chemotherapy (HDC) with carboplatin 1200 mg/m2, etoposide 900 mg/m2 and melphalan 100 mg/m2 with the reinfusion of PBSC. LD-CY plus rhG-CSF in combination with CDDP or EPR mobilised a very large number of PBSC. After a median of 13 days from chemotherapy, the concentration of PBSC in the peripheral blood was 40-fold higher than the same patient's baseline value. Each collection yielded a median of 10.8 x 10(4)/kg colony-forming unit granulocyte-macrophage. Severe myelosuppression occurred in all patients following HDC, but the infusion of PBSC produced a rapid and sustained haemopoietic recovery. After a median of 11 days from reinfusion, haemopoietic engraftment was complete and 80% of the patients had platelets > 100 x 10(9)/l and PMN > 1 x 10(9)/l within 14 days after reinfusion. We can conclude that the present therapeutic approach is an excellent option for mobilisation, collection and transplantation of PBSC during intensive dose adjuvant polychemotherapy of high-risk cancer.

Adult↗

PubMed1993

Immunological reconstitution after high-dose chemotherapy and autologous blood stem cell transplantation for advanced ovarian cancer.

We evaluated the immunological reconstitution of patients who underwent high-dose chemotherapy and autologous blood stem cell transplantation (ABSCT) for advanced ovarian cancer. Sixty days after transplantation a complete reconstitution of lymphocytes and of the CD3, CD4, CD8, CD19, and CD16/56 subsets was observed in this series. A significant increase in the count of interleukin-2 receptor expressing lymphocyte (CD25) was found on day +60 after transplantation compared to that obtained at diagnosis and before transplantation. A significantly higher lymphokine-activated killer (LAK) precursor activity was seen on day +60 compared to the values obtained at diagnosis and before transplantation while natural killer activity did not show any significant variation. We conclude that ABSCT gives prompt and complete immunohaematopoietic reconstitution after high-dose treatment. Moreover, our data support the feasibility of interleukin-2/LAK therapy as consolidative therapy after ABSCT.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed1993

Evaluation of a novel automated protocol for the collection of peripheral blood stem cells mobilized with chemotherapy or chemotherapy plus G-CSF using the Fresenius AS104 cell separator.

Forty-seven peripheral blood stem cell (PBSC) collections were carried out on patients mobilized with chemotherapy and 63 on patients mobilized with chemotherapy plus G-CSF (Filgrastim), using the Fresenius AS104 cell separator and a novel automated PBSC collection protocol. As expected, cell yields were significantly higher in the series mobilized using chemotherapy plus G-CSF. The low platelet and red blood cell contamination permitted freezing of the apheresis product without further manipulation, other than plasma removal in both series. In patients mobilized with chemotherapy we obtained a MNC and a hemopoietic progenitor (CFU-GM, BFU-e, and CD34+ cells) collection efficiency comparable or superior to those reported by Bender (1992) with the Baxter CS3000 Plus after mobilization with cyclophosphamide. A significant decrease in MNC, BFU-e, and CD34+ cell collection efficiency was found in patients mobilized with chemotherapy plus G-CSF compared to those obtained in patients mobilized with chemotherapy alone. Ten patients achieved a prompt and stable engraftment after high dose chemotherapy and the infusion of cryopreserved PBSC collected using this protocol. Studies are in progress in order to improve MNC and hemopoietic progenitor collection efficiency in patients mobilized with G-CSF to obtain a graft in no more than one or two procedures.

Adolescent↗

PubMed1993

Five-year experience in PBSC collection: results of the Catholic University of Rome.

Several authors have reported a faster immunological and hemopoietic post-transplant reconstitution using autologous peripheral blood stem cell (PBSC) than using autologous bone marrow stem cells. A large number of PBSC can be collected by leukapheresis during the hematological recovery after induction or salvage chemotherapy. In our experience we demonstrated that several separators, even if they have different results in mononuclear cell (MNC) yields, red blood cell and platelet contaminations, are able to collect PBSC for autotransplantation in patients with several malignant diseases and different status of disease. Eighty three patients were submitted to 590 leukapheresis procedures using 4 different blood cell separators: the results showed that all employed protocols are efficient in the collection of peripheral MNC even if after the widespread use of granulocytecolony stimulating factor (G-CSF) in the harvesting phase, the blood cell separator efficiency in terms of MNC is reduced. The use of GCSF in combination with other growth factors, during chemotherapy mobilization could simplify, in the future, this therapeutical program even if improvements in the efficiency of PBSC collection protocols are required.

Adolescent↗

PubMed1991

Increased preproneuropeptide Y mRNA in the rat hippocampus during the development of hippocampal kindling: comparison with the expression of preprosomatostatin mRNA.

The levels of preproneuropeptide Y (ppNPY) mRNA and preprosomatostatin (ppSOM) mRNA were analyzed in different brain regions during the development of hippocampal kindling in rats. ppNPY mRNA levels were markedly elevated in the dorsal hippocampus bilaterally, two days after stage 2 (preconvulsive stage) and stage 5 (full seizure expression). The contents of ppSOM mRNA were slightly, although not significantly, increased in the dorsal hippocampus at stage 2 whereas a significant increase was observed in the ipsilateral hippocampus of fully kindled rats. ppNPY and ppSOM mRNA levels were unchanged in the cortex and striatum at both stages of kindling. These results show that an increased synthesis of somatostatin and neuropeptide Y, with a greater effect for the latter, occurs during hippocampal kindling in rats. The relative role of the two peptides in the development and expression of kindling phenomenon remains to be elucidated.

Animals↗

PubMed1991

Changes in pre- and postsynaptic components of noradrenergic transmission in hippocampal kindling in rats.

We investigated whether modifications in noradrenergic neurotransmission occurred during the development of hippocampal kindling in rats. We measured the release of [3H]norepinephrine (NE) induced by field-electrical stimulation, NE-stimulation of inositol phosphates [( 3H]IP) accumulation in the presence of LiCl and isoproterenol-induced accumulation of cAMP in hippocampal slices taken from rats electrically kindled at stages 2 and 5 in the dorsal hippocampus. One week after the last of at least 3 consecutive stage 5 seizures or 48 h after the last stage 2 stimulation, 2 min electrical stimulation of stratum pyramidale CA1-CA3 or dentate gyrus (DG) slices from kindled and contralateral hippocampi induced frequency-dependent NE release (respectively 2, 4 and 8 times spontaneous release measured at 2, 5 and 10 Hz) which did not significantly differ from that observed in shams (implanted with electrodes but not stimulated). Basal release of NE from kindled and sham-treated rats did not differ either. Isoproterenol induced a dose-dependent increase above basal cAMP concentration ranging from 40% at 0.01 microM to 180% at 10 microM (P less than 0.01, Dunnett's test) which did not differ between stages 2 and 5 and sham-hippocampi. NE (1-1000 microM) induced a dose-dependent, prazosin-sensitive increase in [3H]IP accumulation in the hippocampal slices. A significantly higher increase was found at stages 2 (P less than 0.05, Tukey's test) and 5 (P less than 0.05 and P less than 0.01, Tukey's test) compared to shams at all doses studied.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1991

A peptidase-resistant cyclic octapeptide analogue of somatostatin (SMS 201-995) modulates seizures induced by quinolinic and kainic acids differently in the rat hippocampus.

Electroencephalographic (EEG) seizures were measured in rats after intrahippocampal injection of 120 nmol quinolinic acid into the stratum radiatum CA1 or 0.19 nmol kainic acid in the dentate gyrus or in the stratum radiatum. Injection of 5 micrograms SMS 201-995, a peptidase-resistant cyclic octapeptide analogue of somatostatin, into the stratum radiatum, 15 min before quinolinic acid, did not significantly modify the number of seizures and the total time in seizures. Five micrograms SMS 201-995 injected into the stratum radiatum reduced the number of seizures induced by kainic acid in the same area and the total time spent in seizures by 58% and 75%, respectively (Student's t-test; P less than 0.01). In both instances the latency to the first ictal episode was not significantly modified. Lesions of the medial septum, which reduced the activity of choline-o-acetyl-transferase (CAT) in the dorsal hippocampus by greater than 90% after one week did not significantly affect seizures induced by quinolinic acid. In rats lesioned in the medial septum, 5 micrograms SMS 201-995 reduced the total time spent in seizures by 43%, without changing the number of ictal episodes and raised the latency to the first quinolinic acid-induced seizure by 53% (ANOVA 2 x 2, P less than 0.05) but had no effect on these measures in the corresponding sham-operated group.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1991

Autologous blood stem cell harvesting and transplantation in patients with advanced ovarian cancer.

We investigated the feasibility of a programme of autologous blood stem cell (ABSC) harvesting and transplantation in 13 patients with advanced ovarian cancer, previously untreated by chemotherapy or radiotherapy and entering a phase II study of high-dose cisplatin, etoposide and carboplatin with haematopoietic stem cell rescue. Prior to high-dose treatment all patients underwent two courses of cisplatin and cyclophosphamide. An 8-fold increase of the peripheral colony forming unit granulocytic-macrophage (CFU-GM) was observed during recovery from myelosuppression after the first chemotherapy course. The second course determined a 2.5-fold increase of peripheral CFU-GM. In 70% of enrolled patients (nine patients) we were able to perform ABSC harvesting by leukaphereses; in the apheresed patients we harvested an average of 20.8 x 10(4)/kg CFU-GM (range 10.9-37.0). Haematopoietic trilineage engraftment, established as the number of days necessary to reach white blood cells (WBC) greater than 1.0 x 10(9)/l, polymorphonuclear leucocytes (PMN) greater than 0.5 x 10(9)/l and platelets (PLT) greater than 50 x 10(9)/l, occurred very promptly and was sustained in the same series after high-dose cisplatin, carboplatin and etoposide, followed by autologous blood stem cell transplantation (ABSCT). In our experience we found a significant correlation (r = 0.77; P less than 0.05) between CFU-GM infused dose and the engraftment speed of PMN. We conclude that the combination of cisplatin and cyclophosphamide is effective in mobilizing haematopoietic progenitors in the peripheral blood of patients with advanced ovarian cancer, previously untreated by chemoradiotherapy. Moreover, ABSCT is capable of rapidly restoring the haematopoietic function after high-dose treatment and for this reason it represents a particularly advisable therapeutic option for the treatment of solid tumours because these patients are commonly older than 50 and can be excluded from bone marrow transplantation.

Adult↗

PubMed1991

Semiautomated autologous bone marrow processing for transplantation.

This paper describes the development of a semiautomated procedure for autologous bone marrow processing, prior to ex vivo manipulation and/or cryopreservation. This procedure was employed with a pediatric bowl (125 ml Latham bowl) and the automated DuPont Stericell processor. We have obtained a mononuclear cell recovery of 85% and a hemopoietic progenitor cell recovery of 81% (CFU-GM; BFU-E), with a red cell removal of 84%. We believe that a reliable and standardized bone marrow processing procedure is the basic necessity for a bone marrow transplantation program.

Automation↗

PubMed1991

Rationale for large scale bone marrow hemopoietic stem cell manipulation.

Many years have passed since the first attempt in marrow grafting was performed (1939). During this period several techniques have been developed in marrow processing and manipulation to overcome bone marrow transplant complications: the ABO barrier in case of major incompatibility between donor and recipient, the graft-versus-host disease due to the presence of allogeneic mature T-lymphocytes in cellular suspension and the neoplastic cell residue in autografts. At the end, the final volume of autologous mononuclear cell suspension must be frozen and an optimized cryopreservation allows a cell viability and subsequently an adequate medullar repopulating capacity.

Blood Group Incompatibility↗

PubMed1991

High dose chemotherapy with cisplatin, VP16 and carboplatin with stem cell support in patients with advanced ovarian cancer.

Authors treated 4 patients suffering from advanced ovarian cancer with high-dose chemotherapy and autologous peripheral blood stem cell (APBSC) or autologous bone marrow stem cell (ABM) as hematopoietic support. In three patients were collected peripheral blood stem cells using a fully automated blood cell separator during hematopoietic recovery following aplasia induced by non-intensive chemotherapy (cisplatin 200 mg/m2 and cyclophosphamide 1,500 mg/m2). Hemopoietic reconstitution of the four patients submitted to APBSC or ABM support after high-dose chemotherapy (cisplatin 100 mg/m2, VP16 650 mg/m2 and carboplatin 1,800 mg/m2) showed the low hematological toxicity of our treatment with APBSC support. Moreover, the drug combination of cisplatin and cyclophosphamide has clinical activity in ovarian cancer and it is an optimal association to mobilize and harvest large number of PBSC.

Adult↗

PubMed1991

A comparison between two different procedures for bone marrow processing: a semiautomated procedure vs manual starch sedimentation.

After high-dose chemotherapy, autologous cryopreserved bone marrow infusion is employed to restore rapidly the compromised hematopoietic function. An efficient bone marrow processing reduces the infusion toxicity produced by hemolized red cells, granulocytes and platelets clumping and DMSO amount; moreover it increases freezing efficacy, a critical step in autologous bone marrow grafting techniques. Gravity sedimentation technique with 6% hydroxyethyl-starch (HES) or a semiautomated procedure using a blood cell processor were used in our center to manipulate ex-vivo the collected bone marrow. In our experience we compared these two different procedure and we evaluated their efficiency.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed1991

Autologous bone marrow processing for autotransplantation using an automated cell processor and a semiautomated procedure.

Twenty bone marrow aspirates harvested for autotransplantation from 20 patients suffering from several oncohematological diseases were processed using the automated Du Pont SteriCell processor. In 15 bone marrow harvests, the interface buffy coat cells were collected using the SteriCell processor in manual mode with a semiautomated procedure. The procedure yielded an average red cell removal of 84% and an average mononuclear cell (MNC) recovery of 86%. Cloning efficiencies of hematopoietic progenitor cells (CFU-GM and BFU-e) did not differ between processed and recovered MNCs. Four cryopreserved bone marrow buffy coats were thawed and reinfused into four patients who had undergone high dose chemotherapy. Stable engraftment was observed in all cases. In five bone marrow harvests, the SteriCell automated density gradient MNC isolation procedure was performed after buffy coat collection. The whole two-step procedure allowed an average MNC recovery of 69%. CFU-GM and BFU-e assays did not show a significant difference in cloning efficiency between processed and recovered bone marrow MNCs. We conclude that the SteriCell processor offers rapid, safe and feasible procedures for the semiautomated processing of human bone marrow for transplantation. The clinical efficacy of density gradient separated bone marrow employing the automated step and the opportunity to use fully automated processing must be investigated.

Adult↗

PubMed1990

Autoradiographical analysis of excitatory amino acid binding sites in rat hippocampus during the development of hippocampal kindling.

Binding sites for excitatory amino acids have been determined by autoradiographical procedures in the rat hippocampus and striatum during hippocampal kindling. The binding sites measured were the N-methyl-D-aspartate (NMDA)-sensitive sites for L-[3H]glutamate and [3H]MK-801 sites (transmitter recognition site and ion channel of the NMDA receptor, respectively), [3H]alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA) sites (quisqualate receptor), [3H]kainate sites (kainate receptor) and NMDA-insensitive sites for L-[3H]glutamate. In general, little change was apparent in the hippocampus or striatum for any of these binding sites when assessed 48 h after attaining stages 1/2, 3 or 5 of kindling. These results suggest that hippocampal kindling does not bring about a change in the excitatory amino acid receptor binding sites examined, and that the appearance of an NMDA receptor-mediated component to synaptic responses in the hippocampus produced by kindling, cannot be explained on this basis.

Amino Acids↗