Biomedical subjects

D Damiani

Publications and source records attributed to D Damiani.

At least 55 records · Page 3Linked to original sources

PubMed1998

Adjuvant treatment with cyclosporin A increases the toxicity of chemotherapy for remission induction in acute non-lymphocytic leukemia.

P-glycoprotein (Pgp)-related multidrug resistance (MDR) is frequently observed in acute non-lymphocytic leukemia (ANLL) and is associated with a poor response to standard chemotherapy. Cyclosporin A (CsA) is an effective downmodulator of Pgp-related MDR in vitro and has already been tested for that purpose in vivo also. Since Pgp is expressed in several normal cells and tissues, the modulation of Pgp can also modify total body exposure to antileukemic drugs and can alter and increase the toxicity of the antileukemic treatment. We report here the results of a study where 46 consecutive adult patients with ANLL were assigned to receive the same standard chemotherapy regimen of arabinosyl cytosine and idarubicin (IDA) for remission induction or consolidation, without or with CsA. Twenty-eight patients received 36 courses of chemotherapy without CsA and 18 patients received 32 courses of chemotherapy with CsA. CsA dose was 10-12.5 mg/kg/day and was given as a continuous i.v. infusion for 72 h. Whole blood CsA steady-state concentration ranged between 0.61 and 1.14 microM. The IDA area-under-the-curve was about twice as high in the cases that received CsA than in the other cases. CsA had no detectable effects on renal function and fluid balance, but significantly increased systemic blood diastolic pressure and conjugated bilirubine concentration. Furthermore, CsA-treated patients had greater, and more severe, oral and intestinal mucosal toxicity, with more severe adverse events, including more cases of gram-negative bacteremia, and with a delayed hemopoietic recovery. In conclusion, this study showed that an attempt at an effective downmodulation of Pgp-mediated MDR would substantially increase the hemopoietic and mucosal toxicity of antileukemic treatment and that the increase is accounted for, at least in part, by an increase of total body exposure to IDA.

Adult↗

PubMed1998

Central diabetes insipidus as a complication of neonatal pathology: report of three cases.

Three patients, 11, 17 and 41 days old with various degrees of central nervous system (CNS) lesions developed central diabetes insipidus as a complication of hypothalamic damage. Two of the children had congenital CNS malformations including meningomyelocele, hydrocephalus, and prosencephaly, while the third child presented Streptococcus agalactiae meningitis, complicated with CNS hemorrhage and hypertensive dilatation of the lateral ventricles. All of them fulfilled the criteria for central diabetes insipidus, reaching high levels of serum sodium and osmolality, along with hypotonic urine. The responses to intranasal arginine-vasopressin were prompt, normalizing the serum levels of sodium and increasing urinary osmolality, allowing a better metabolic balance, avoiding continuing damage to the already compromised CNS. The neonatologist must be aware of the possibility of this kind of complication even in a normal child with CNS infection. Imaging studies showing hemorrhage in the region of the posterior hypothalamus must be a sign that this type of complication is able to occur.

Adolescent↗

PubMed1998

BCL-2 immunohistochemical evaluation in B-cell chronic lymphocytic leukemia and hairy cell leukemia before treatment with fludarabine and 2-chloro-deoxy-adenosine.

Bcl-2 overexpression has been shown to be associated with several malignancies, including B-cell chronic lymphocytic leukemia (CLL) and non-Hodgkin's lymphomas (NHL), mainly low-grade and follicular in type. It has as yet not been described in hairy cell leukemia (HCL). In 30 patients with CLL and 14 with HCL who were consecutively selected for treatment with purine analogues (Fludarabine in CLL and 2-chloro-deoxy-adenosine in HCL), we evaluated bcl-2 oncoprotein expression in leukemic cells on marrow sections that were taken before treatment and stained immunohistochemically with a monoclonal antibody (Dakopatts 124 clone), by the avidin-biotin-peroxidase method. All samples were found to be bcl-2 positive, with a staining intensity that was moderate to strong in CLL and weak to moderate in HCL. 83% of CLL and 100% of HCL patients were responsive to purine analogues. These findings show that bcl-2 is overexpressed in almost all cases CLL and HCL and that bcl-2 overexpression does not predict a poor response to purine analogues, which are believed to induce apoptosis.

2-Chloroadenosine↗

PubMed1998

P170 (Pgp) expression in leukemic cells after therapeutic exposure to arabinosyl cytosine.

The expression of the mdr-1 gene coding for a transmembrane 170 KD glycoprotein (P170 or PGP) is an important cause of multidrug resistance (MDR). In tumor cells the expression of the gene may vary and there is experimental evidence that it can be induced by exposure to MDR-unrelated agents. We investigated if the therapeutic exposure to Arabinosyl Cytosine (AC) could affect the level of P170 expression in the blast cells of acute non-lymphocytic leukemia (ANLL). The reactivity to the P170-directed MRK 16 monoclonal antibody of the marrow blast cells from 27 patients with ANLL prior and after treatment with standard dose AC was evaluated by flow cytometry. After treatment with AC the MRK 16 mean fluorescence index (MFI) was increased in 5/18 cases of primary and previously untreated ANLL and in 7/9 cases of relapsed or secondary leukemia. Overall, the mean value of the MFI was 6.8+/-3.6 before and 9.0+/-3.8 after AC (P=0.001, Wilkoxon matched pairs test). Therapeutic exposure to AC in vivo may increase P170 expression in leukemic cells. This may influence the definition and the quantitation of resistance and may have therapeutic implications, concerning the association with other cytotoxics and the use of MDR modifiers.

Journal Article↗

PubMed1998

Autologous stem cell transplantation for multiple myeloma: a single centre experience.

Thirty-two patients with multiple myeloma (MM) were autografted in our Centre over a 3-year period. Twenty-three patients had a newly diagnosed MM submitted to one induction regimen and 9 had a refractory or relapsing disease treated with at least two different chemotherapy lines: 15 out of 32 patients were sensitive to conventional treatment. In 2 patients BM was harvested while in the majority PBSC were collected after administration of 7 g/m2 Cyclophosphamide plus G-CSF (in 25 patients) or G-CSF alone at the dose of 16 microg/Kg/daily for 5-7 days (in 5 patients). Conditioning regimen was busulfan 16 mg/Kg plus melphalan 120 mg/m2. One patient died of cerebral hemorrhage after reinfusion of PBSC. Out of 31 evaluable patients, 24 (77%) had a response which was complete in 6 patients (19%) and partial in 18 patients (58%), 5 cases (17%) had no response, and 2 (6%) showed myeloma progression. There was a statistical difference in the outcome between newly diagnosed and pretreated patients (p = 0.003). At a median follow-up of 9 months (range 5-37), two patients had died for progression and 3 out of the 29 alive, relapsed after 17, 18 and 36 months respectively. Although median overall survival was not reached, there was a significant survival benefit for autografted patients in comparison with a matched control group conventionally treated in our Centre before 1994 (p = 0.02).

Journal Article↗

PubMed1998

P-glycoprotein (PGP), and not lung resistance-related protein (LRP), is a negative prognostic factor in secondary leukemias.

BACKGROUND AND OBJECTIVE: In cell lines, there is an ongoing debate about the role of the lung resistance-related protein (LRP) whereas the role played by P-glycoprotein (PGP) in determining a multidrug resistance is well known. The aim of this study was to evaluate the frequency and the role of a PGP and an LRP overexpression in affecting the intracellular daunorubicin accumulation (IDA) and in predicting the therapy outcome on a subset of overt secondary acute non lymphocytic leukemias (ANLL). An adjunctive point was to evaluate the efficacy of the reversal agent SDZ PSC 833 (PSC) in counteracting impaired IDA. DESIGN AND METHODS: By flow cytometry, PGP and LRP expression and the IDA were evaluated on 54 overt secondary ANLL PGP and LRP overexpressions were respectively defined by an MRK-16 mean fluorescence index (MFI) > or = 6 (PGP+) and by an LRP-56 MFI > or = 5 i.e. by MRK-16 and LRP-56 MFIs higher than the one observed in normal leukocytes. The blasts' IDA was studied after a two-hour incubation in 1000 ng/mL daunorubicin in the presence or in the absence of the MDR reversal agent SDZ PSC 833 (PSC) 1.6 mumol. RESULTS: A PGP overexpression was detected in 40/54 (74%) cases while an LRP overexpression was observed on 33/54 (61%) cases. No differences were found in terms of PGP and LRP expressions between ANLL developing after chemo/radiotherapy (therapy-related ANLL) or evolving from a myelodysplastic syndrome (MDS-related ANLL). Compared to the PGP-, the PGP+ cases showed a significantly lower mean IDA (DNR NMFI 196 +/- 46 vs. 267 +/- 53, p < 0.001). The co-incubation of DNR with the PSC significantly increased only the mean IDA of the PGP+ cases, that grew from a DNR NMFI of 196 +/- 46 to a DNR NMFI of 284 +/- 67 (p < 0.0001). With respect to normal leukocytes, even the PGP- cases had an impaired IDA suggesting that other mechanisms, including an LRP overexpression, could affect the IDA. A strongly negative correlation was observed between PGP overexpression and therapy outcome, in fact, 8/10 (80%) PGP- but only 2/27 (7%) PGP+ patients obtained complete remission (p = 0.0002). Moreover, 7/33 (21%) cases showing an impaired IDA (NMFI < 280) but 4/4 (100%) with NMFI > 280 had complete remission (p = 0.006). No correlation was found between therapy response and LRP or CD34 expression. INTERPRETATION AND CONCLUSIONS: This data suggests that an important role in determining therapy outcome is played by PGP in secondary leukemias. Even if the LRP is frequently overexpressed in secondary leukemias and is likely to contribute to the reduction of the intracellular drug accumulation, the role played by LRP in determining the therapy-outcome has still to be cleared.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed1998

Autologous stem cell transplantation in multiple myeloma: a single center experience.

This study shows the feasibility and safety of autologous stem cell transplantation in 32 of 98 multiple myeloma patients referred to our institution over a 3-year period. Complete response rate was 19% and partial response rate 58%. A significantly better outcome was shown among newly diagnosed patients in comparison with pretreated patients.

Adult↗

PubMed1997

Randomized trial of autologous filgrastim-primed bone marrow transplantation versus filgrastim-mobilized peripheral blood stem cell transplantation in lymphoma patients.

Although a large amount of data is available on the effects of filgrastim (granulocyte colony-stimulating factor [G-CSF]) on the mobilization of stem cells in the circulation, data concerning its effects on bone marrow (BM) harvesting is scarce and controversial. We have designed a randomized trial comparing filgrastim-mobilized peripheral blood stem cell (PBSC) transplantation with filgrastim-primed autologous bone marrow transplantation (ABMT). Fifty-five patients affected by non-Hodgkin's (n = 38) or Hodgkin's (n = 17) lymphoma, selected for autologous transplantation over a 12-month period in a single institution, were randomized 2:1 to undergo BM or PB harvest/collection after priming for 3 days with filgrastim, 16 microg/kg body weight daily subcutaneously. BM priming with G-CSF allowed the harvest of a significantly higher number of mononuclear cells (MNC) (0.53 x 10(8)/kg, range, 0.32 to 1.40), as compared with a historical control of unprimed BM harvests (0.43 x 10(8) MNC/kg, range, 0.15 to 0.72, P = .001). After high-dose ablative therapy, median time to neutrophil recovery above 0.5 x 10(9)/L was 12 days for BM and 11 days for PB (P = .219); median time to platelet recovery above 20 x 10(9)/L was 13 days for BM and 11 days for PB (P = .242). The same number of red blood cells, platelet transfusions, and posttransplant G-CSF doses were required in the two groups of patients. Less patients (50% v 70%) became febrile in the group transplanted with mobilized PB, but days of fever/patient and days on antibiotics were overlapping. The median time spent in the hospital after reinfusion was 16.5 and 15.5 days after primed BM and primed PB, respectively (P = .134). These data suggest that in patients with lymphoma submitted to autologous transplantation, the reinfusion of filgrastim-primed BM or filgrastim-mobilized PB leads to similar results, with an advantage of only 1 day in the neutrophil recovery and 1 day on the time spent in the hospital in favor of primed PB. Either option can be chosen on the basis of the availability of a surgery room or cell separator facilities and considering the patients' characteristics and wishes.

Bone Marrow Transplantation↗

PubMed1997

Effects of homoharringtonine alone and in combination with alpha interferon and cytosine arabinoside on 'in vitro' growth and induction of apoptosis in chronic myeloid leukemia and normal hematopoietic progenitors.

Homoharringtonine (HHT) is a cephalotaxine alkaloid that showed clinical efficacy in the chronic phase of chronic myeloid leukemia (Ph1+CML). As a single agent, it resulted in effectively controlling leukocytosis and in producing sporadic karyotypic conversions; its clinical use in combination with interferon (IFN-alpha) for the treatment of CML could thus be considered. In this study we evaluated the growth inhibition and the induction of apoptosis determined by HHT alone and in combination with IFN-alpha and cytosine arabinoside (Ara-C) on normal and CML (both in chronic, CML-CP and in blastic phase; CML-BP) hematopoietic progenitors. HHT is able to determine a dose-dependent cell growth inhibition; evaluation of cytotoxic activity on semisolid cultures showed an activity significantly higher on CML-CP than on normal cells (P = 0.02 for HHT 50 ng/ml and P = 0.01 for HHT 200 ng/ml). HHT exerted a synergistic effect with IFN-alpha, Ara-C and IFN-alpha + Ara-C in inhibiting CML-CP colony growth; the same activity was demonstrated by the combination of HHT with Ara-C and by the triple combination, but not by HHT + IFN-alpha, on normal myeloid progenitors. The triple combination only was able to exert a synergistic effect in CML-BP. The induction of apoptosis resulted HHT dose-dependent in CML-CP and normals; at higher drug concentrations (100-200-1000 ng/ml), HHT induced a significant increase of apoptotic cells (for normals: P = 0.04, P = 0.02 and P = 0.04; for CML-CP: P = 0.01, P = 0.01 and P = 0.04, respectively); no significant changes were observed in CML-BP. In conclusion, the differences in cytotoxic effect and apoptosis induction observed, depending on the various phases of CML, add experimental evidence to the different clinical results between the chronic phase, where the clone is responsive to HHT, and the acute phase, where the drug is ineffective. The in vitro synergism of HHT with Ara-C and IFN-alpha in CML-CP suggests further evaluation in the clinical setting.

Adult↗

PubMed1997

P-glycoprotein (PGP) and lung resistance-related protein (LRP) expression and function in leukaemic blast cells.

P-glycoprotein (PGP) lung resistance protein (LRP) and multidrug resistance associated protein (MRP) expressions and function were evaluated by flow cytometry in 65 leukaemic patients (38 acute non-lymphocytic leukaemias, eight acute lymphocytic leukaemias, 19 Ph-positive chronic myeloid leukaemias in blastic phase). By using the MRK-16, the LRP-56 and the MRPm6 MoAbs, 34% of the cases did not over-express any proteins (-); 24.5% over-expressed (+) only PGP, 11% only LRP, 1.5% only MRP, 24.5% both PGP and LRP, and 4.5% both PGP and MRP. The mean intracellular daunorubicin accumulation (IDA) and rhodamine 123 (Rh123) retention in the presence or absence of the reversal agent SDZ PSC 833 (PSC) of the PGP-/LRP-/MRP- cases were comparable to the ones observed in normal leucocytes. With respect to the non-over-expressing cases, the PGP-/LRP+/MRP- cases showed only an impaired IDA (mean 204 +/- 29; P < 0.001). The PGP+/ LRP+/MRP- cases had a defect both in IDA (mean 166 +/- 47, P < 0.001) and Rh123 retention (mean 0.42 +/- 0.14: P < 0.001), which were both corrected by PSC. All the PGP+/LRP+/MRP- cases had a defect in IDA (mean daunorubicin (DNR) accumulation 192 +/- 44; P < 0.001). However, only in 8/16 of them an evident defect in Rh123 retention was found. In conclusion, both PGP and LRP over-expression were common in leukaemia. An impaired IDA was found in all cases over-expressing PGP, LRP or both. The study of Rh123 retention could give incorrect information about the blast cells' ability to accumulate cytotoxic drugs in patients over-expressing both PGP and LRP.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed1997

True hermaphroditism: clinical aspects and molecular studies in 16 cases.

Although true hermaphroditism (TH) accounts for less than 10% of intersex patients, it stands as a diagnostic challenge and has allowed a better understanding of the mechanisms involved in sexual differentiation. In this paper we review the clinical and laboratory data as well as molecular biology findings on 16 TH patients followed up at the Pediatric Endocrine Unit, Instituto da Criança, Hospital das Clínicas. São Paulo University Medical School. They were of a mean age of 3 years 8 months and nine of them were black. All the patients had ambiguous external genitalia as the main complaint. The 46,XX karyotype accounted for 50% of the cases and the ovotestis was the most frequent gonad found (59%). In the eight TH patients with a 46,XX karyotype, the sex-determining region of the Y chromosome (SRY) was negative, posing an intriguing question about the testicular differentiation mechanisms involved in these cases. In 7/19 ovotestes, the ovarian portion of the gonad has been preserved, keeping open the possibility of fertility. The female sex option was made in 10/16 cases (62.5%) and three patients exhibited spontaneous puberty. The mechanism through which testicular tissue develops without SRY has not yet been completely clarified, suggesting the involvement of the X chromosome as well as autosomal genes in the process.

Child↗

PubMed1997

Sequential intensive treatment with the F-MACHOP regimen (+/- radiotherapy) and autologous stem cell transplantation for primary systemic CD30 (Ki-1)--positive anaplastic large cell lymphoma in adults.

Most of the adult patients with primary systemic CD30 (Ki-1)-positive anaplastic large cell lymphoma (ALCL) reported in the literature have been treated with combination chemotherapy (CHT), with only an occasional patient being autotransplanted, mostly after relapse. Here we report a series of 19 patients treated at our Institution with a sequential intensive therapeutic program including CHT (the F-MACHOP regimen given for 6 cycles), radiotherapy (RT), and autologous stem cell transplantation (ASCT) after conditioning with the BAVC regimen. Eleven of 19 (58%) patients achieved a complete remission (CR) after CHT; 3 after RT and 4 after ASCT (1 patient is still not evaluable for response to ASCT). The actuarial overall survival is 100% at a median of 49 months from diagnosis and the actuarial disease free survival is 100% at a median of 41 months from the time CR was reached. These data suggest that ALCL can be successfully managed with a sequential intensive treatment that prevents early relapses and projects these patients as long-term survivors.

Adolescent↗

PubMed1997

Treatment intensification of malignant lymphomas with autologous bone marrow transplantation and granulocyte colony stimulating factor.

Treatment intensification with autologous bone marrow transplantation (ABMT) was administered to 37 cases of Hodgkin's and non-Hodgkin's lymphoma (HL and NHL) who were in complete or partial remission (CR or PR) after chemotherapy (MOPP/ABVD or F-MACHOP respectively) and to 12 cases of HL and NHL who were in relapse. ABMT treatment was BAVC for NHL and BEAM for HL. Marrow cells were harvested from the marrow and cryopreserved. The number of mononuclear marrow cells that was reinfused ranged between 0.19 and 0.80 x 108/Kg b.w. (median 0.39). All the patients were treated with granulocyte colony stimulating factor (G-CSF, Filgrastim) at a dose of 5 mg/Kg b.w. from day +4 until the absolute neutrophil count exceeded 1 x109/L for 3 consecutive days. Engraftment was observed in all cases, and no transplant-related deaths occurred. The patients with NHL and HL received a median of 12 (range 2-19) and 14.5 (range 9-27) doses of G-CSF respectively. Median time to 20 x 109/L platelet count was 14 to 17 days. Median time to an absolute neutrophil count 0.5x109/L was 13 days. A febrile episode during the period of post-transplant aplasia was documented in 35 patients (71%). Fever was associated with Gram+ bacteraemia in 31% of the cases and with Gram- bacteraemia in 11% of cases. Herpes Simplex infection was documented in two cases. No fungal infections were recorded. Median hospitalisation time from reinfusion ranged between 19.5 days (NHL) and 23 days (HL). Thirty-four of 37 cases (92%) who were transplanted in CR or in PR are currently alive and in continuous CR with a median follow-up time of 37 months after ABMT. Three of 12 cases (25%) who were transplanted in relapse are alive and in CR. Our data point out that ABMT followed by G-CSF is a safe and a very effective procedure for high risk malignant lymphomas, when ABMT is planned and is performed not as a rescue procedure but when it is integrated in the treatment strategy from the very beginning.

Journal Article↗

PubMed1996

Modulation of phosphoinositide turnover by chronic nicergoline in rat brain.

Basal and agonist-stimulated phosphoinositide (PI) turnover and inositol 1,4,5 -trisphospate (InsP3) content in rat brain were investigated after chronic nicergoline (SERMION) treatment. Oral administration of nicergoline (5 mg/kg b.i.d. for 7 weeks) enhanced the basal turnover of PI in the cerebral cortex compared to controls. This effect was paralleled by a significant rise of cortical InsP3 levels. No significant changes of noradrenaline- or carbachol-induced accumulation of [3H]-inositol-I-phophate ([3H]-InsP1) were found in cortices from nicergoline-treated rats. On the contrary, in the striatum nicergoline significantly potentiated the responsiveness of noradrenaline- and carbachol-stimulated PI turnover, leaving unchanged the basal production of [3H]-InsP1 and InsP3 levels. The results suggest that the interaction of nicergoline with PI transducing pathway might have relevance to the mechanisms of action of nicergoline.

Animals↗

PubMed1996

Primary systemic CD30 (Ki-1)-positive anaplastic large cell lymphoma of the adult: sequential intensive treatment with the F-MACHOP regimen (+/- radiotherapy) and autologous bone marrow transplantation.

Few series of adult patients with primary systemic CD30 (Ki-1)-positive anaplastic large cell lymphoma (ALCL) are reported in the literature; most of them have been treated with combination chemotherapy (CHT), with only an occasional patient being autotransplanted, mainly after relapsing. The remission rate ranges from 60% to 90%, but relapses are frequent (up to 60%) and precocious (mainly in the first 24 months). The aim of our study was to analyze the outcome of a series of adult patients affected by primary systemic ALCL that were treated at our institution with a sequential intensive therapeutic program including CHT, radiotherapy (RT), and autologous bone marrow transplantation (ABMT). Sixteen consecutive, unselected patients with ALCL were identified. All of them were treated with the 5-fluorouracil, methotrexate, cytosine arabinoside, cyclophosphamide, doxorubicin, vincristine, and prednisone (F-MACHOP) regimen; 9 of 16 (56.2%) reached a complete remission (CR). In six cases with residual mediastinal disease, involved-field RT was performed, allowing three additional patients to become free of disease. All 16 were then autotransplanted with bone marrow stem cells after conditioning with the cytosine arabinoside, etoposide, cyclophasphamide, and carmustine (BAVC) regimen. A present, 16 of 16 patients are alive and in CR. The actuarial overall survival is 100% at a median of 45.5 months, and the actuarial disease-free survival is 100% at a median of 33.5 months. These data suggest that ALCL can be successfully managed with a sequential intensive treatment (CHT +/- RT + ABMT) that prevents early relapses and projects these patients as long-term survivors.

Adolescent↗

PubMed1996

Screening for multidrug resistance in leukemia: cell reactivity to MRK-16 correlates with anthracycline retention and sensitivity of leukemic cells.

The biologic and clinical importance of the multidrug resistance (MDR) that is related with the overexpression of the P170 glycoprotein (Pgp) is widely recognized. However, a major issue that has not yet been solved is the definition of the degree of Pgp expression which is associated with a significant decrease of the sensitivity of the cells to chemotherapy. For this reason we studied the leukemic cells from 83 cases of acute leukemia. Leukemic cells were fixed in PLP and treated with saponine. Pgp expression was assayed by flow cytometry, using the anti Pgp monoclonal antibody MRK-16. Results were expressed both as the number of positive cells and by the intensity of the reaction as defined by the mean fluorescence index (MFI), i.e. the ratio between the mean fluorescence intensity of the MRK-16 incubated cells and of the IgG2a incubated cells. Thus, Pgp expression was compared with the results of two in vitro tests of cell sensitivity to anthracyclines, daunorubicin (DNR) cell retention and DNR cytotoxicity. We found that it was not the number of MRK-16 positive cells, but the degree of the reaction with MRK-16 (MFI) that significantly related to the anthracycline toxicity tests. Therefore, we propose that for clinical purposes a quick and cheap determination of Pgp-related MDR in leukemic cells may be obtained by measuring the MFI with MRK-16 in a standard flow cytometry assay and that the assay may indeed be sufficient to estimate Pgp expression as well as the influence of Pgp on cell sensitivity to anthracyclines.

Anthracyclines↗

PubMed1996

Molecular analysis of sex determination in sex-reversed and true hermaphroditism.

The SRY (sex region of Y) gene determines testis formation but not all cases of sex reversal in humans can be explained by alterations in this gene. We studied one 46,XY female, four 46,XX males, and nine true hermaphrodites (TH): three with an XY and six with an XX chromosomal constitution. The SRY gene was identified in the XX males and the TH with a Y chromosome but was not demonstrated in the XY female and the six XX TH. The Y-heterochromatin region was also identified in one 46,XX male, indicating a low grade mosaicism undetected by cytogenetics. The amplification of the amelogenin gene showed the presence of a 977-bp band that belongs to the short arm of chromosome X in all patients but the absence of a 780-bp band of the short arm of chromosome Y in three 46,XX males and in all the 46,XX TH. These studies demonstrate that the molecular study of sex-reversed patients and TH will help to understand the complex mechanisms of sex determination. The SRY gene is involved but other genes on the X chromosome and autosomes still remain to be studied.

Adolescent↗

PubMed1995

Modulation of hippocampal ACh release by chronic nicergoline treatment in freely moving young and aged rats.

The effects of nicergoline on basal and K(+)-stimulated release of ACh in the hippocampus of 3- and 19-month old rats has been studied by microdialysis. A significant decrease of basal ACh release (59%) was found in aged vehicle treated rats in comparison to young rats. High-K+ (100 mM) in the perfusate strongly increased the release of ACh by up to 6-fold over the baseline of both young and aged rats. Chronic oral administration of nicergoline to aged rats (5 mg/kg b.i.d. for 6 weeks) significantly reversed (93%) the age-related decrease of basal release of ACh, leaving the increase due to K+ depolarization unchanged. In young animals, nicergoline did not affect the basal output of ACh, but enhanced the K(+)-evoked release of ACh by 39%. Results from this study demonstrate that nicergoline treatment increases the ability of hippocampal cholinergic terminals to release ACh, and suggest that this drug can reset the cholinergic impairement associated with aging.

Acetylcholine↗