Biomedical subjects

R Serafini

Publications and source records attributed to R Serafini.

At least 19 recordsLinked to original sources

PubMed2003

Efficacy of granulocyte transfusions for neutropenia-related infections: retrospective analysis of predictive factors.

BACKGROUND: The transfusion of G-CSf-primed granulocytes (GTX) might represent an important treatment option for neutropenia-related infections unresponsive to conventional antimicrobial therapies and to recombinant hematopoietic growth factors. However, few studies to date have identified the factors that can predict clinical outcome and the patient populations who are likely to benefit most from GTX. The primary endpoint of the present retrospective study was to evaluate the efficacy of GTX in 22 patients with hematological malignancies who developed neutropenia-related bacterial and fungal infections that were unresponsive to appropriate antimicrobial therapies. METHODS: Peripheral blood granulocytes were collected by continuous-flow leukapheresis from HLA-identical siblings after priming with G-CSF. The response to GTX was classified as 'favorable' if clinical symptoms and signs of infection resolved or 'unfavorable' if clinical symptoms and signs of infection were unchanged or worsened. Control of infection at Day 30 after the enrollment in the GTX program was considered as the outcome variable in multiple regression analysis. RESULTS: Two patients died of infection before receiving the granulocyte concentrates. Bacterial infections (monomicrobial or mixed bacteremias) were documented in 11 patients, whereas fungal infections (fungemia or focal fungal infections) were diagnosed in seven patients. In two patients, no infecting agent could be isolated (clinical infection). Control of infection at Day 30 after the first GTX was achieved in 10 of 20 assemble patients. Overall, 54% of patients with bacterial infections had a favorable response, compared with 57% of patients with fungal infections. No differences in terms of survival were found when comparing patients with bacterial and those with fungal infections at a median follow-up 90 days from the first GTX. In univariate analysis, disease status before GTX, e.g., complete or partial remission, and spontaneous recovery of the neutrophil count were significantly associated with control of infection. when multivariate regression models were formed, the recovery 0.5 x 10 (9)/L PMN was the only parameter that significantly and independently correlated with a favorable response to GTX. DISCUSSION: GTX can be used to successfully treat bacterial as well as fungal infections in severely neutropenic patients when administered early after the onset of febrile neutropenia in patients with remission of the underlying disease and who are likely to recover marrow function.

Adult↗

PubMed2001

Molecular and clinical follow-up after stem cell transplantation for multiple myeloma.

Molecular follow-up has been carried out using immunoglobulin heavy-chain (IgH) gene finger-printing, a polymerase chain reaction (PCR)-based technique with a sensitivity of 0.1-0.01% (10(-3)-10(-4)), in 22 patients affected by multiple myeloma and submitted to stem cell transplantation (SCT). Twelve patients were submitted to either single or double autologous unselected peripheral blood progenitor cell transplantation, eight patients were submitted to autologous CD34+ immunoselected transplantation and two patients were submitted to allogeneic bone marrow (one patient) or peripheral blood CD34+ stem cell (one patient) transplantation. At diagnosis, all patients showed clonal CDIII rearrangement. The molecular analysis performed on leukapheresis products and CD34+ purified fractions proved to be contaminated by myeloma cells. During follow-up after autografting, all but one patient retained clonal rearrangement despite clinical complete remission (CR) in ten of them. These ten patients either relapsed (Rel) or showed progressive disease (PD) after transplantation; four of them died. Only one patient did not retain clonal rearrangement after autologous transplantation; she is currently alive in CR after a follow-up of 100 months. One patient submitted to allogeneic transplantation is currently alive with no evidence of the disease, but still retains clonal rearrangement after a follow-up of 47 months. Another patient died 4 months after transplantation after succumbing to fatal pneumonia showing myeloma progression.

Adult↗

PubMed2001

Peripheral blood progenitor cell collection after epirubicin, paclitaxel, and cisplatin combination chemotherapy using EPO-based cytokine regimens: a randomized comparison of G-CSF and sequential GM-/G-CSF.

BACKGROUND: The peripheral blood progenitor cell (PBPC) mobilization capacity of EPO in association with either G-CSF or sequential GM-CSF/G-CSF was compared in a randomized fashion after epirubicin, paclitaxel, and cisplatin (ETP) chemotherapy. STUDY DESIGN AND METHODS: Forty patients with stage IIIB, IIIC, or IV ovarian carcinoma were enrolled in this randomized comparison of mobilizing capacity and myelopoietic effects of G-CSF + EPO and GM-/G-CSF + EPO following the first ETP chemotherapy treatment. After ETP chemotherapy (Day 1), 20 patients received G-CSF 5 microg per kg per day from Day 2 to Day 13 and 20 patients received GM-CSF 5 microg per kg per day from Day 2 to Day 6 followed by G-CSF 5 microg per kg per day from Day 7 to Day 13. EPO (150 IU per kg) was given every other day from Day 2 to Day 13 to all patients in both arms of the study. Apheresis (two blood volumes) was performed during hematologic recovery. RESULTS: The magnitude of CD34+ cell mobilization and the abrogation of patients' myelosuppression were comparable in both study arms; however, GM-/G-CSF + EPO patients had significantly higher CD34+ yields because of a higher CD34+ cell collection efficiency (57.5% for GM-/G-CSF + EPO and 46.3% for G-CSF + EPO patients; p = 0.0009). Identical doses of PBPCs mobilized by GM-/G-CSF + EPO and G-CSF + EPO drove comparable hematopoietic recovery after reinfusion in patients treated with identical high-dose chemotherapy. CONCLUSION: The sequential administration of GM-CSF and G-CSF in combination with EPO is feasible and improves the PBPC collection efficiency after platinum-based intensive polychemotherapy, associating high PBPC mobilization to high collection efficiency during apheresis.

Adult↗

PubMed2001

Immune reconstitution after autologous selected peripheral blood progenitor cell transplantation: comparison of two CD34+ cell-selection systems.

BACKGROUND: Selection of CD34+ PBPCs has been applied as a method of reducing graft contamination from neoplastic cells. This procedure seems to delay lymphocyte recovery, while myeloid engraftment is no different from that with unselected PBPC transplants. STUDY DESIGN AND METHODS: Lymphocyte recovery was studied in two groups of patients who underwent autologous CD34+ PBPC transplant with two different technologies (Ceprate SC, Cellpro [n = 17]; CliniMACS, Miltenyi Biotech [n = 13]). The median number of CD34+ cells transfused was 3.88 x 10(6) per kg and 3.32 x 10(6) per kg, respectively. Residual CD3 cells x 10(6) per kg were 4.97 and 0.58, respectively (p = 0.041). Residual CD19 cells x 10(6) per kg were 1.33 and 0.73, respectively (NS). RESULTS: No differences were found between the two groups in total lymphocyte recovery to >0.5 x 10(9) per L, which achieved a stable count by Day 30. During the study period, the CD4+ cell count remained below 0.2 x 10(9) per L, and the B-cell subset showed a trend toward normalization. CD3/HLA-DR+ and CD16/56 increased markedly in both groups by Day 30. An increase in CMV (13%) and adenovirus (17.4%) infection was found in both groups. CONCLUSION: Both CD34+ cell selection technologies used here determined an excellent CD34+ cell purity and an optimal depletion of T cells. The high rate of viral complications is probably due to the inability of residual T cells left from the CD34+ cell selection to generate, immediately after transplant, an adequate number of virus-specific lymphocytes.

Adolescent↗

PubMed2001

A new blood donation strategy: automated blood collection (ABC).

BACKGROUND: The aim of this study was to find out if Cobe Trima, a blood cell separator that automatically collects RBC, PLT and plasma, is adequate for routine multiple blood donation by apheresis. MATERIALS AND METHODS: Eighty donors underwent multiple blood component donations by Cobe Trima. Blood counts were determined on the apheresis products to analyze their quality. RESULTS: Eighty procedures were performed collecting 193 products. The average platelet yield was 3.5x10(11) (+/- 0.46) in the 54 single product (SP) procedures and 7x10(11) (+/- 0.88) in the 26 double product (DP) procedures. WBC contamination of the PLT products was 1.7 x 10(5) (1.2-4.2). The mean platelet efficiency was 60 +/- 8.35% for SP and 66 +/- 9.59% for DP. The hemoglobin (Hb) content per unit was 46.21 g (+/- 7.84) in 8 DP and 40.82 g (+/- 6.41) in 34 SP procedures. CONCLUSION: The production of standardized blood components with good PLT yield and low WBC contamination plus high efficiency makes Trima one of the best blood cell separators of the new generation.

Adolescent↗

PubMed2000

Structural domains of the human GABAA receptor 3 subunit involved in the actions of pentobarbital.

This study was conducted to search for the residues of the beta3 subunit which affect pentobarbital action on the gamma-aminobutyric acid type A (GABAA) receptor. Three chimeras were constructed by joining the GABAA receptor beta3 subunit to the rho1 subunit. For each chimera, the N-terminal sequence was derived from the beta3 subunit and the C-terminal sequence from the rho1 subunit, with junctions located between the membrane-spanning regions M2 and M3, in the middle of M2, or in M1, respectively. In receptors obtained by the coexpression of alpha1 with the chimeric subunits, in contrast with those obtained by the coexpression of alpha1 and beta3, pentobarbital exhibited lower potentiation of GABA-evoked responses, and in the direct gating of Cl- currents, an increase in the EC50 together with a marked decrease in the relative maximal efficacy compared with that of GABA. Estimates of the channel opening probability through variance analysis and single-channel recordings of one chimeric subunit showed that the reduced relative efficacy for gating largely resulted from an increase in gating by GABA, with little change in efficacy of pentobarbital. A fit of the time course of the response by the predictions of a class of reaction schemes is consistent with the conclusion that the change in the concentration dependence of activation by pentobarbital is due to a change in pentobarbital affinity for the receptor. Therefore, the data suggest that residues of the beta3 subunit involved in pentobarbital binding to GABAA receptors are located downstream from the middle of the M2 region.

Animals↗

PubMed2000

Autologous graft-versus-host disease after CD34+-purified autologous peripheral blood progenitor cell transplantation.

Autologous graft-versus-host disease (GVHD) has been frequently reported after cyclosporine A (CsA) administration in the autologous setting. This complication is related to the disruption of self-tolerance mechanisms induced by CsA and may exert an antitumor effect. We report the spontaneous occurrence of autologous GVHD after CD34+-purified peripheral blood progenitor cell transplantation (PBPCT) in 5 out of 24 consecutive patients (20.8%). The syndrome was characterized by skin rash (5/5), pruritus (5/5), eosinophilia (5/5), and fever (2/5) occurring at a median of 37 days (range 22-60) after transplantation. Diagnosis was confirmed by skin biopsy in all patients. The syndrome was self-limiting, lasted a median of 25 days, and did not require treatment. The rate of autologous GVHD was high after CD34+-purified autologous PBPCT. In fact, no autologous GVHD was documented in an historical control of 100 consecutive patients submitted to unmanipulated PBPCT at the same institution. The manipulation of the graft by the purging procedure causes a profound T lymphocyte depletion, thus possibly perturbing the equilibrium between autoregulatory cells and autocytotoxic T cells. These observations add new interest to the antitumor efficacy of autologous GVHD and suggest new questions regarding the role of transplantation for autoimmune diseases.

Adolescent↗

PubMed2000

Stem cell collection using the dideco excel continuous flow blood cell separator: parameters for optimal stem cell collection timing.

This study evaluates stem cell collection procedures performed with the Dideco Excel blood cell separator, with particular attention given to yields and separator collection efficiencies. Patients' blood precounts and yield parameters related to the harvest capacity of the collection system were investigated. Fifty-five collection procedures were analyzed in 32 patients suffering from hematological malignancies and solid tumors and mobilized with chemotherapy plus G-CSF. The median blood volume processed in each procedure was 15.8 liters (12-19.750), with a blood flow rate of 70 ml/min. Patients had the following median blood precount value: NC 7.81x10(9)/L, CD34+ cells 49.08x10(3)/ml. Leukapheresis procedures gave the following yields: NC 14.95x10(9), MNC 10.83x10(9), CD34+ cells 4.37x10(6); yields/kg, NC 0.21x10(9)kg, MNC 0. 15x10(9)/kg CD34+ cells 4.26x10(6)/kg. Procedures show the following collection efficiencies: NC 10.79%, MNC 29.06%, CD34+ 42.33%, PLT 26.5%. The RBC (red blood cell) contamination of the product was (median value) 20.9 ml for each procedure, and for platelets 1.76x10(11) per procedure. The CD34+ cell precounts strongly correlated with the CD34+ yields/kg (r=0.82. p=0.000). Furthermore the NC and MNC precounts correlated with the CD34+ yields/kg but only the MNC precount correlation is notable (r=0.57, p=0.000). The logistic regression analysis shows that CD34+ (p=0.008) but not NC (po=0.14), MNC (p=0.09), or PLT (p=0.53) precounts significantly influenced the collection of a sufficient dose of CD34+ cells for transplantation (> or =2.5x10(6)/kg). Eleven of the thirty-two patients have been transplanted till now, and all had a prompt and lasting trilineage engraftment NC >1x10(9)/L on day 12 (10-17). Our data show that the collection system analyzed in this report is able to collect large amounts of progenitor cells, harvesting >2.5x10(6)/kg CD34+ cells with a single procedure in 68.8% of patients and assuring complete recovery after stem cell transplantation.

Adolescent↗

PubMed1999

GABAA receptor subunit composition and functional properties of Cl- channels with differential sensitivity to zolpidem in embryonic rat hippocampal cells.

Using flow cytometry in conjunction with a voltage-sensitive fluorescent indicator dye (oxonol), we have identified and separated embryonic hippocampal cells according to the sensitivity of their functionally expressed GABAA receptors to zolpidem. Immunocytochemical and RT-PCR analysis of sorted zolpidem-sensitive (ZS) and zolpidem-insensitive (ZI) subpopulations identified ZS cells as postmitotic, differentiating neurons expressing alpha2, alpha4, alpha5, beta1, beta2, beta3, gamma1, gamma2, and gamma3 GABAA receptor subunits, whereas the ZI cells were neuroepithelial cells or newly postmitotic neurons, expressing predominantly alpha4, alpha5, beta1, and gamma2 subunits. Fluctuation analyses of macroscopic Cl- currents evoked by GABA revealed three kinetic components of GABAA receptor/Cl- channel activity in both subpopulations. We focused our study on ZI cells, which exhibited a limited number of subunits and functional channels, to directly correlate subunit composition with channel properties. Biophysical analyses of GABA-activated Cl- currents in ZI cells revealed two types of receptor-coupled channel properties: one comprising short-lasting openings, high affinity for GABA, and low sensitivity to diazepam, and the other with long-lasting openings, low affinity for GABA, and high sensitivity to diazepam. Both types of channel activity were found in the same cell. Channel kinetics were well modeled by fitting dwell time distributions to biliganded activation and included two open and five closed states. We propose that short- and long-lasting openings correspond to GABAA receptor/Cl- channels containing alpha4beta1gamma2 and alpha5beta1gamma2 subunits, respectively.

Animals↗

PubMed1999

Large volume leukapheresis for collecting hemopoietic progenitors: role of CD 34+ precount in predicting successful collection.

In this work we evaluated the efficacy of stem cell collection with Large Volume Procedures. (LVP), and analysed the importance of the CD34+ cell precount in promoting the collection of a sufficient number of CD34+ cells for transplantation, using the Univariate Logistic Regression analysis. Eighty-nine leukapheresis were performed in 49 patients with hematological malignancies and solid tumors, mobilized with chemotherapy plus Granulocyte Colony Stimulating Factor (G-CSF). For each procedure 15.8 liters of blood were processed. The median value of Nucleated Cells (NC) and CD34+ cells precount was respectively 8.29 x 10(9)/ml (range 1.13/45.4) and 43.08 x 103/ml (range 1.06/795.2). Results show the capability of LVP to collect large quantities of hemopoietic progenitors with a median CD34+ cell total yield of 215.02 x 10(6) (range 5.03/2210). The yields per patients' body weight were: CD34+ cells 3.23 x 10(6)/kg (range 0.081/41.58). The regression analysis between blood cell precounts and collection yields gave the following correlations: the CD34+ cell precount correlates with CD34+ yield (r = 0.78 p < 0.00) and with CD34+ cell yield/kg (r = 0.76 p < 0.00). The number of CD34+ cells processed correlated with the number of CD34+ cells collected/kg (r = 0.83 p < 0.000). To investigate the importance of CD 34+ cell precount in promoting CD34+ cell yields > or =2.5 x 10(6)/kg we performed a Univariate Logistic Regression analysis that showed in our patients a probability of collecting > or =2.5 x 10(6) CD34+/kg that rose from 0.6 to 0.95 for CD 34+ precounts that oscillated from 30 to 40 x 10(3) CD34+ cells/ml, respectively. The Univariate Logistic Regression gave a probability of collecting > or =2.5 x 10(6) CD34+ cells/kg that oscillated between 0.64/0.98 for values of CD34+ cells processed from 6 x 10(6)/kg to 8 x 10(6)/kg, p < 0.000. Sixty-three percent of patients reached the target dose of 2.5 x 10(6) CD34+ cells/kg with only one LVP. Until now 12 patients have been transplanted and all have had a prompt and complete lasting recovery. These results confirm the efficacy of LVP in harvesting hemopoietic progenitors and their ability in reconstituting hemopoiesis of transplanted patients, enabling the estimation of CD34+ precounts and CD34+ cells processed values, highly predictive for the collection of > or =2.5 x 10(6) CD34+ cells/kg. Furthermore, the Logistic Model suggests that the best strategy to plan a successful CD34+ cell collection procedure is to identify for each patient the amount of CD34+ cells/kg to be processed rather than the fixed processing of 3/5 blood volumes in all patients.

Adolescent↗

PubMed1999

The application of two different blood cell separators to harvest CD34+ cells in patients suffering from non Hodgkin's lymphoma.

From January 1996 until now, thirty-eight PBSC procedures were carried out on 20 patients suffering from NHL, mobilized by polichemotherapy regimens plus recombinant human Granulocyte-Growth Factor (rhG-CSF). Patients were enrolled in PBSC procedures using Dideco Excel (group A) and Cobe Spectra v.4.7 (group B) blood cell separators. Twelve patients were enrolled in group A (6 males and 6 females, median age 33) and 9 patients in group B (5 males and 4 females, median age 55). The mean White Blood Cell (WBC) and Mononuclear Cells Fraction (MNC) peripheral blood counts were not statistically different in either group and neither were blood CD34+ cell peripheral counts. CD34+ cell peripheral value was predictive of the CD34+ yield while mean values of harvested CD34+ cells were not significantly different. CD34+ cell efficiencies were statistically the same. The CD34+ cell purity of the apheresis harvest was statistically different between the two groups (group A = 3.0+/-2.2%; group B = 1+/-0.9%) p = 0.001. High CD34+ cell yields were observed in both groups which confirms that both blood cell separators are able to harvest hematopoietic progenitor cells from peripheral blood.

Adolescent↗

PubMed1998

"No allogeneic blood transfusion" protocol for the surgical correction of craniosynostoses. I. Rationale.

Improved anesthesiological and surgical care has resulted in a progressively declining need for allogeneic blood transfusion. In infants with craniosynostosis, however, allogeneic blood transfusion is still performed as a routine procedure. In the present paper, the authors describe a protocol they have devised with the aim of limiting or even avoiding allogeneic blood transfusion even in very young patients, consequently avoiding the risks of infective or immunologic reactions associated with the procedure. The protocol is based on stimulation of the hematopoietic system with erythropoietin, selection of an appropriate age for operation when a favorable balance between fetal and adult-type hemoglobin is established (that is after 4-6 months), preoperative preparation of the autologous blood supply, and intraoperative blood salvage.

Age Factors↗

PubMed1998

"No allogeneic blood transfusion" protocol for the surgical correction of craniosynostoses. II. Clinical application.

The authors describe the results obtained in 13 consecutive cases of craniosynostosis operated on according to a protocol devised at avoiding allogeneic blood transfusion. The protocol is based on pre- and postoperative treatment with erythropoietin, preoperative autologous blood donation, preoperative normovolemic hemodilution and intraoperative blood salvage. Nine subjects were affected by simple forms of craniosynostosis, whereas the remaining 4 presented with oxycephaly or craniofacial syndromes. Five of the 13 children were under 7 months and a further 3, under 10 months of age at the time of the surgical operation. Seven children weighed less than 10 kg. Allogeneic blood transfusion was avoided in 11 of the 13 children considered. Two failures - defined as the necessity to reinfuse the patient with an allogeneic blood transfusion - were recorded, 1 of them resulting from an unexpected hemorrhage during surgery. The results obtained indicate that this protocol designed to avoid allogeneic blood transfusion can be safely applied in the great majority of children with craniosynostosis, even when the surgical correction is carried out early in life.

Blood Transfusion, Autologous↗

PubMed1998

Highly fluorescent reticulocytes after CD34+ peripheral blood progenitor cell transplantation.

Highly fluorescent reticulocyte (HFR) counts were evaluated in 13 consecutive patients affected by hematological malignancies and submitted to autologous selected CD34+ peripheral blood progenitor cell (PBPC) transplantation. Results were compared with a historical group of patients comparable for age, disease and conditioning regimen submitted to unfractionated PBPC transplantation. HFR counts of the CD34+ group declined to an undetectable level from day +4 to day +10 when they became detectable and reached 5% of total reticulocyte count by day +12. In the historical group, the nadir was identical but the recovery was faster (day +9). Total reticulocyte count > 1% was achieved at days +17 and +11, respectively. The absolute neutrophil count (ANC) recovery was identical in both groups, achieving a value > 0.5 x 10(9)/l at day +13 after reinfusion. Hence, in the historical group, HFR count gave advance notice of complete and stable hemopoietic engraftment while in the CD34+ group HFR and ANC count showed almost simultaneous recovery.

Adult↗

PubMed1998

Dominant GABA(A) receptor/Cl- channel kinetics correlate with the relative expressions of alpha2, alpha3, alpha5 and beta3 subunits in embryonic rat neurones.

The embryonic appearance of GABAergic cells and signals in the rat nervous system coincides with the appearance of transcripts encoding some but not all of the subunits forming GABA(A) receptor/Cl- channels. Quantitative in situ hybridization studies reveal higher variabilities in alpha2 and alpha3 subunit transcripts relative to others examined (alpha5, beta2, beta3 and gamma2) in six spinal and supraspinal regions. Immunocytochemistry of cells dissociated from the embryonic CNS shows that alpha2 and alpha3 subunits are detectable in differentiating neurones. FACS analyses of dissociated cells immunostained with alpha2- or alpha3- antibodies reveal immunopositive subpopulations of variable size in each region. Whole-cell recordings of acutely adherent neurones show that GABA activates Cl- currents whose fluctuations characteristically vary depending on a neurone's region of origin. Spectral analyses indicate a predominance of the low frequency (< 5 Hz) components, which vary regionally. Regression analyses reveal that (i) channel properties correlate with subunit transcript levels and (ii) dominant channel kinetics correlate with alpha2 and alpha3 subunit transcripts indexed as a ratio and with coexpressions of alpha5 and beta3. The correlations strongly suggest that alpha3 subunits in embryonic neurones are expressed in native receptor/channel complexes with slower kinetics than those containing alpha2 without alpha3 subunits. Thus, GABA(A) receptor/Cl- channels in these embryonic neurones may be encoded by the six transcripts (alpha2, alpha3, alpha5, and beta2, beta3, and gamma2) with proportions of alpha2, alpha3, alpha5, and beta3 subunits critical in determining their dominant kinetics.

Animals↗

PubMed1998

Initially expressed early rat embryonic GABA(A) receptor Cl- ion channels exhibit heterogeneous channel properties.

We have studied the earliest expression of GABA-induced CI- channels in the rat embryonic dorsal spinal cord (DSC) using in situ hybridization, immunocytochemistry, flow cytometry and electrophysiology. At embryonic day 13 (E13) cells in the dorsal region are still proliferating. In situ hybridization consistently showed transcripts encoding only three GABAA receptor subunits (alpha4, beta1 and gammal); immunocytochemistry both in tissue sections and in acutely isolated cells in suspension demonstrated the expression of the corresponding proteins and also revealed staining for other subunits (alpha2, alpha3, beta3, gamma2). In patch-recordings performed in cells acutely isolated from the dorsal cord, responses to GABA were detected in 356 out of 889 cells. GABA-evoked responses, which often displayed the opening of a few channels, were mediated by CI- ions, were inhibited by bicuculline and picrotoxin, and potentiated by benzodiazepines. Taken together, these observations indicate that CI- channels likely involve GABAA type receptors. Fluctuation analysis revealed channel kinetics consisting of three exponential components (Ts: approximately 1,9 and 90 ms) and a wide variety of inferred unitary conductance values, ranging between 4 and 40 pS. A comparison of these results with observations in other, later embryonic cell types and recombinant receptors suggests that most of the earliest E13 DSC GABAA receptors may include alpha3 subunit. These GABAA receptor Cl- channels may be activated physiologically as both GABA synthesizing enzymes and GABA are present in the E13 dorsal cord.

Animals↗

PubMed1998

Potentiometric study of resting potential, contributing K+ channels and the onset of Na+ channel excitability in embryonic rat cortical cells.

Resting membrane potential (RMP), K+ channel contribution to RMP and the development of excitability were investigated in the entire population of acutely dissociated embryonic (E) rat cortical cells over E11-22 using a voltage-sensitive fluorescent indicator dye and flow cytometry. During the period of intense proliferation (E11-13), two cell subpopulations with distinct estimated RMPs were recorded: one polarized at approximately -70 mV and the other relatively less-polarized at approximately -40 mV. Ca2+o was critical in sustaining the RMP of the majority of less-polarized cells, while the well-polarized cells were characterized by membrane potentials exhibiting a approximately Nernstian relationship between RMP and [K+]o. Analysis of these two subpopulations revealed that > 80% of less-polarized cells were proliferative, while > 90% of well-polarized cells were postmitotic. Throughout embryonic development, the disappearance of Ca2+o-sensitive, less-polarized cells correlated with the disappearance of the proliferating population, while the appearance of the K+o-sensitive, well-polarized population correlated with the appearance of terminally postmitotic neurons, immuno-identified as BrdU-, tetanus toxin+ cells. Differentiating neurons were estimated to contain increased K+i relative to less-polarized cells, coinciding with the developmental expression of Cs+/Ba2+-sensitive and Ca2+-dependent K+ channels. Both K+ channels contributed to the RMP of well-polarized cells, which became more negative toward the end of neurogenesis. Depolarizing effects of veratridine, first observed at E11, progressively changed from Ca2+o-dependent and tetrodotoxin-insensitive to Na+o-dependent and tetrodotoxin-sensitive response by E18. The results reveal a dynamic development of RMP, contributing K+ channels and voltage-dependent Na+ channels in the developing cortex as it transforms from proliferative to primarily differentiating tissue.

Animals↗

PubMed1998

Assessment of hematological and immunological function during long-term follow-up after peripheral blood stem cell transplantation.

BACKGROUND AND OBJECTIVE: Long-term hemopoietic and immunological profile after autologous peripheral blood progenitor cells transplantation (PBPCT), in patients affected by hematological malignancies is largely unknown. The aim of this work was to detect the impact of high dose chemotherapy and PBPCT on hemopoietic and immunological function compared to conventional chemotherapy. DESIGN AND METHODS: Patients had to fulfill the following criteria: continuous complete remission after PBPCT, follow-up longer than 12 months, no chemo or radiotherapy or biological response modifiers after PBPCT. Twenty-five patients were considered eligible for this analysis. Stable and complete hemopoietic reconstitution (Hb > 12 g/dL, WB > 4.0 x 10(9)/L, ANC > 1.5 x 10(9)/L and Pits count > 150 x 10(9)/L), morphological examination of peripheral blood and bone marrow, cytogenetic analysis and immunological profile were evaluated at 12 months and yearly thereafter. RESULTS: Immunological reconstitution showed a persistent reduction of CD4/CD8 ratio up to five years after PBPCT. This reduction was related to a persistent increase of CD8+ lymphocytes and a constant reduction of CD4+ lymphocytes. INTERPRETATION AND CONCLUSIONS: Defects observed in PBPCT patients are induced by the procedure itself, by the conditioning regimen or both. The different behavior in the immune reconstitution of CD8+ subset after PBPCT may be favored by an extrathymic origin of these cells while CD4+ subset recovery which is thymus-dependent is impaired after PBPCT in adult population. Long-term hemopoietic reconstitution after PBPCT is rapidly obtained and is stable over the years, long-term immunological function seems to be abnormal in these patients and these abnormalities are long-lasting.

Adult↗