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A Riccardi

Publications and source records attributed to A Riccardi.

At least 55 records · Page 3Linked to original sources

Treatment of multiple myeloma according to the extension of the disease: a prospective, randomised study comparing a less with a more aggressive cystostatic policy. Cooperative Group of Study and Treatment of Multiple Myeloma.

The purpose of the study was to ascertain whether the prognostic significance of staging in multiple myeloma (MM) is influenced by the aggressiveness of effective induction treatment and/or by continuing or discontinuing maintenance chemotherapy. Patients with untreated stage I MM (defined according to Durie and Salmon) were randomised between being followed without cytostatics until the disease progressed and receiving six courses of melphalan and prednisone (MP-P) just after diagnosis; stage II patients were uniformly treated with MPH-P and stage III patients were randomised between MPH-P and four courses of combination chemotherapy with Peptichemio, vincristine and prednisone (PTC-VCR-P). Within each stage, responsive patients were randomised between receiving additional therapy only until maximal tumour reduction was reached (plateau phase) and continuing induction therapy indefinitely until relapse. With resistant, progressive or relapsing disease, patients originally treated with MPH-P for induction received combination chemotherapy and vice versa. The overall first response rate was 43.8% (42.2% in 206 stage I, II and III patients treated with MPH-P and 48.0% in 75 stage III patients treated with combination chemotherapy, P = NS). Combination chemotherapy was more myelotoxic than MPH-P and, in particular, caused more non-haematological side-effects. Both the less and the more aggressive induction policies gave the same disease control. Progression of disease was statistically similar in stage I patients who were initially left untreated and in t hose who received MPH-P just after diagnosis; median duration of first response was similar in stage III patients receiving MPH-P and in those on combination chemotherapy. In all stages, discontinuing or continuing maintenance did not alter the median duration of first response. The overall second response rate was 28.5% (34.0% to MPH-P and 25.3% to combination chemotherapy, P = NS). Median survival was greater than 78 months in stage I, was 46.3 months in stage II and was 24.3 months in stage III patients, still independent of both induction and post-induction policies. In MM, the significance of staging for survival is independent of both the aggressiveness of induction and of continuing or discontinuing maintenance chemotherapy after the maximal tumor reduction has been achieved. Both MPH-P and and the association of PTC, VCR and P are effective in inducing first response and also second response in patients failing on the alternative regimen, but PTC-VCR-P causes more side effects. Thus, the overwhelming majority of patients with MM can safely be given MPH-P as first therapy, and this treatment may be delayed in early diseases.

Antineoplastic Agents↗

Cell cycle kinetic effects of tamoxifen on human breast cancer cells. Flow cytometric analyses of DNA content, BrdU labeling, Ki-67, PCNA, and statin expression.

Tamoxifen is known to inhibit the growth of some human mammary carcinoma cells; this effect is accompanied by a decrease in the proportion of cells synthesizing DNA. In this work, flow cytometry of DNA and of bromodeoxyuridine labeling and the evaluation of the cell cycle-related antigens Ki-67, PCNA, and statin were used to investigate the changes in the proliferation kinetics of MCF-7 cells before and after treatment with 10(-7) M TAM. The treatment with TAM induced a significant decrease in the fraction of S-phase cells and an increase in those with a DNA content typical of G0/1 phase. The TAM-induced block in G0/1 is paralleled by a decrease in the frequency of cells expressing Ki-67 and PCNA, and by an increase in statin-positive (G0) cells. These results confirmed that the TAM-induced inhibition of cell growth is associated with major changes in the cell cycle parameters of MCF-7 cells, and provide the first experimental evidence that two main mechanisms are operating: the accumulation of cells in G1, before the onset of S-phase, and the exit of some cells from the cycling compartment.

Biomarkers, Tumor↗

Granulocyte-macrophage colony-stimulating factor increases dose intensity of chemotherapy in small cell lung cancer. Relationship between clinical results, peripheral blood cell modifications, and bone marrow kinetics.

BACKGROUND: Until now, no dose-response correlation has been clearly defined in small cell lung cancer (SCLC). METHODS: Forty-one consecutive patients with SCLC entered this study, 21 (limited [L]/extensive [E] = 10/11) patients (group A) received cisplatin 60 mg/m2, etoposide 120 mg/m2 x 3, and escalating epirubicin (5 mg/m2) starting from 45 mg/m2, every 3 weeks for six courses. RESULTS: The maximum tolerated dose (MTD) was reached at epirubicin 60 mg/m2. In 15 (L/E = 9/6) patients (group B), who were submitted to the same combination plus granulocyte-macrophage colony-stimulating factor (GM-CSF) 10 micrograms/kg on days 4 to 14, the MTD was reached at the epirubicin dose of 70 mg/m2. In five (L/E = 4/1) patients (group C) treated as in group B, but with a GM-CSF priming from day -17 to -7 before the first cycle, the MTD was again at 70 mg/m2. Group A patients received 73% of the planned cycles; groups B and C, 86% (P < 0.015). Twenty-five percent of group A cycles versus 6% of groups B and C were delayed (P = 0.0018). The chemotherapy dose was reduced in 15% versus 1.5% of cycles (P = 0.0072). A significant difference was observed in the delivered dose intensity (DI) and in the relative DI with an increase of 29% for cisplatin and etoposide (P < 0.0005; P = 0.0017) and of 63% for epirubicin (P < 0.0000). In group A, the response rate was 72% (24% complete response [CR]), and in groups B and C, 95% (40% CR). Bone marrow myeloid precursor (BMMP) proliferative activity was determined in 21 patients after in vivo bromodeoxyuridine infusion. In GM-CSF-treated patients the production rate evaluated before the starting of the second, fourth, and fifth cycle was significantly higher than the corresponding value of the first cycle. CONCLUSIONS: GM-CSF induces a significant increase of dose intensity by a long-lasting and cumulative enhancement of BMMP proliferation.

Aged↗

Cell kinetics with in vivo bromodeoxyuridine assay, proliferating cell nuclear antigen expression, and flow cytometric analysis. Prognostic significance in acute nonlymphoblastic leukemia.

BACKGROUND: The proliferative characteristics of acute nonlymphoblastic leukemia (ANLL) were studied in vivo, and data were correlated with response to chemotherapy and survival. METHODS: Sixty-five patients with untreated ANLL and 15 patients with solid tumors and normal bone marrow (BM) received 250 mg/m2 of bromodeoxyuridine (BUdR); bivariate flow cytometric (FCM) analysis then was used to measure cell BUdR incorporation and DNA content to obtain a complete set of kinetic parameters (i.e., BM BUdR-labeling index, DNA-synthesis time, potential doubling time [Tpot], and cell production rate). The percentage of blasts with positive results for proliferating cell nuclear antigen (PCNA) also was obtained by FCM analysis on the same BM samples, and these kinetic parameters were derived specifically for the ANLL proliferating compartment (growth fraction). Induction therapy, consisting of vincristine, arabinosylcytosine, and daunomycin, was administered subsequently to the patients with ANLL. RESULTS: Overall ANLL proliferative activity was lower than normal myelopoiesis, and a short Tpot was found to be a favorable factor for achieving complete remission (CR), the duration of CR, and survival. When the growth fraction was considered, however, ANLL proliferative activity was higher and more like that of normal BM. The kinetic differences detected in the PCNA-positive cells of patients with CR and no response and those with CR and survival durations above and below the median values for the entire series were highly significant in univariate analysis and retained a strong independent prognostic value when multivariate analysis was performed. CONCLUSIONS: These data show the clinical feasibility of a detailed study of cell kinetics by means of new FCM-based techniques and reinforce the clinical value of pretreatment proliferative activity in ANLL.

Adult↗

Bone marrow myeloid cell kinetics during treatment of small cell carcinoma of the lung with chemotherapy not associated and associated with granulocyte-macrophage colony-stimulating factor.

Information on the kinetics of bone marrow (BM) myeloid precursors (BMMP) is required for integrating cancer chemotherapy with granulocyte-macrophage colony-stimulating factor (rhGM-CSF), with the aim of reducing neutropenia. Using bivariate flow-cytometric analysis of the in vivo incorporation of bromode-oxyuridine (BUDR) vs DNA content we have studied the kinetics of BMMP in 21 patients with SCLC during the first of six chemotherapy courses (etoposide, epirubicin, and cis-platinum, days 1-3, every 21 days), given alone (eight patients) or followed by rhGM-CSF (10 micrograms/kg/day s.c., days 4-14) as BM rescue (eight patients) or both preceded (days -17 to -7, as BM priming) and followed by rhGM-CSF (five patients). At 11-14 days after the start of these therapies there was an increase in the baseline proliferative activity of proliferating BMMP and a shortening in the time needed by the metamyelocyte to mature and to leave the marrow. Both effects were greater and were maintained to a significantly greater degree a week later in patients who received chemotherapy plus rhGM-CSF rescue than in those who received chemotherapy alone or rhGM-CSF priming alone. At day 11-14 the pretreatment median cell production rate of pBMMP was increased by 340%, 150%, and 183% and the maturation time was reduced by 80%, 45%, and 57%, respectively, in the three groups. A week later, the corresponding figures were 206%, 111%, and 157% and 50%, 18%, and 45%. Hence, an identical rhGM-CSF schedule is more effective in increasing the neutrophil production by BMMP when given following chemotherapy as BM rescue than before it as BM priming. In both the rescue and the priming schedule, the increase in proliferative activity of BMMP just at the end of rhGM-CSF stimulation was linked to both an increase in the labeling index and a reduction in duration of S-phase (TS), while a week later it was linked solely to reduction in TS. This could actually reduce one of the two kinetic targets of subsequently administered cytostatics, i.e., a high LI and a long time spent in S phase. From this study, accurate kinetic data can be obtained with the in vivo BUDR technique that are useful in scheduling rhGM-CSF.

Aged↗

Sustained complete hematological remission in essential thrombocythemia after discontinuation of long-term alpha-IFN treatment.

In essential thrombocythemia patients alpha-IFN rapidly reduces platelet count, and it is also able to maintain a low count during long-term treatment. In order to verify if long-term IFN treatment can produce sustained remission in selected patients, we decided to suspend IFN treatment in two subsets of 21 patients on long-term alpha-IFN treatment: (a) all six patients who had shown a platelet count below 450 x 10(9)/l for at least 2 months with 3 MU once a week; (b) three patients who had shown the same platelet count for at least 2 months with 3 MU three times a week. After withdrawal of alpha-IFN treatment, a rapid increase in the platelet count was observed in all three patients requiring 3 MU three times a week. Three of the six patients treated with 3 MU once a week are still free of symptoms and have been in complete hematological remission (platelet count below 450 x 10(9)/l) for 9+, 13+, and 14+ months, respectively. As far as the three remaining cases are concerned, one was not assessable because of loss to follow-up, while the other two relapsed after 1 and 2 months. We believe that the three cases of sustained remission might be the result of a long-term tumor load reduction produced by the alpha-IFN treatment. Finally, the factor best able to predict sustained, unmaintained remission seems to be the clinical response to a low dose of alpha-IFN during the maintenance phase, rather than disease features prior to treatment.

Humans↗

Presenting features of monoclonal gammopathies: an analysis of 684 newly diagnosed cases. Cooperative Group for the Study and Treatment of Multiple Myeloma.

OBJECTIVES: The clinical, laboratory and radiologic features at diagnosis of 684 newly diagnosed patients with monoclonal gammopathy were revised in order to underline the differences between monoclonal gammopathies of undetermined significance (MGUS) and stage I multiple myeloma (MM). DESIGN: Patients were screened for inclusion in a prospective controlled protocol for treatment of MM. Those having serum or urine monoclonal component (MC) were diagnosed as MM when they demonstrated osteolysis and/or bone marrow plasma cells (BMPC) > 20%; patients not fulfilling these criteria were considered MGUS. SETTING: Patients were recruited from 24 general or university hospitals from the departments of internal medicine, haematology and medical oncology. SUBJECTS: Seven-hundred-and-fifty were enrolled between January 1986 and March 1990; 684 (343 MGUS and 341 MM) were able to be evaluated for this study and 78 were stage I MM. INTERVENTIONS: Complete clinical, radiologic and laboratory work-up was carried out at the referral centres. MAIN OUTCOME MEASURES: The main outcome expected was the confirmation that BMPC > 20% could reliably differentiate stage I MM from MGUS. RESULTS: At a median follow-up of 36 months (minimum follow-up: 18 months), MGUS had a lower progression rate to overt MM, longer overall survival and different causes of death than stage I MM. Further differences concerned erythrocyte sedimentation rate (28 vs. 47, P < 0.001), per cent reduction of normal immunoglobulin (86 vs. 60%, P < 0.001), serum MC (1.6 vs. 2.2 g dl-1, P < 0.001) and thymidine kinase level (3.3 vs. 4.5 mU ml-1, P < 0.05). CONCLUSIONS: The study suggests that 20% BMPC can be taken as a safe cut-off point at which to differentiate MGUS from early MM and outlines a few simple parameters which can be of diagnostic aid.

Aged↗

Serum thymidine kinase in monoclonal gammopathies. A prospective study. The Cooperative Group for Study and Treatment of Multiple Myeloma.

Between January 1986 and March 1990, the serum levels of thymidine kinase (TK) were evaluated at diagnosis in 97 patients with monoclonal gammopathy of undetermined significance (MGUS) and 149 patients with multiple myeloma (MM) enrolled in a prospective protocol for treatment of MM. At presentation, patients with MGUS had lower TK levels than those with Stage I MM (P less than 0.05) and the overall population of those with MM (P less than 0.0005). TK levels were increased in advanced stages in comparison with earlier ones (P less than 0.01). The TK level was related to survival. With a median follow-up of 29 months, patients with TK levels greater than 7.0 U/microliters had shorter survival times than those with lower levels (medians, 23 and 42 months; P less than 0.0001). In a multivariate analysis, TK explained most of the variability of survival (P less than 0.0001), the remaining being accounted for by serum creatinine and beta-2 microglobulin. No changes in TK levels occurred during follow-up of patients with stable MGUS, whereas TK levels increased in two patients at time of progression to overt MM. In patients with MM, TK levels decreased (P less than 0.01) in those who responded to treatment but increased in those having relapses (P less than 0.03) and those with progressive disease (P less than 0.03). These results indicate that TK has clinical and prognostic relevance in monoclonal gammopathies, and additional investigations are warranted to determine whether it is a useful tool for the clinical evaluation, staging, and follow-up of patients with MM.

Aged↗

Cerebrospinal fluid pharmacokinetics of carboplatin in children with brain tumors.

The pharmacokinetics of carboplatin in cerebrospinal fluid (CSF) and plasma was studied in five children with brain tumors (four medulloblastomas and one ependimoblastoma) who underwent preirradiation treatment with carboplatin. Carboplatin pharmacokinetics was studied following the administration of 600 mg/m2 as a 1-h infusion. Four children were treated a few weeks after surgery, whereas one child with an unresectable tumor was treated prior to surgery. All patients had a ventricular-peritoneal CSF shunt connected to a subcutaneous reservoir. Total platinum and free carboplatin were measured. The mean AUC values for free carboplatin in CSF and plasma were 2.29 +/- 1.20 and 8.18 +/- 1.27 mg ml-1 min, respectively. The mean ratio of CSF AUC to plasma AUC was 0.28 (range, 0.17-0.46). Both plasma peak levels and AUC values showed limited interpatient variability. On the other hand, carboplatin levels in CSF showed substantial interpatient variability, with a greater than 5-fold difference in peak levels and a 3-fold difference in AUC values being recorded. The interpatient difference in CSF pharmacokinetics may have been related at least in part to the different anatomical alterations induced by the surgical procedures or by the presence of a large tumor mass. In the four evaluable patients exhibiting macroscopic residual tumor, we observed one complete remission (CR) and two partial remissions (PR) following two cycles that consisted of two doses of 600 mg/m2 carboplatin given on 2 consecutive days (total dose, 1200 mg/m2) and were separated by a 1-month interval. These results may give some indication as to the optimal dose and schedule for carboplatin administration in the treatment of primitive neuroectodermic tumors (PNET).

Brain Neoplasms↗

Flow cytometric analysis of multidrug-resistance-associated antigen (P-glycoprotein) and DNA ploidy in human colon cancer.

In many cell systems, resistance to cytotoxic drugs is acquired by the amplification and/or overexpression of the multidrug resistance (mdr) gene, which codes for the glycoprotein, p170 (P-glycoprotein). Moreover, in a variety of malignant tumours there is increasing evidence of the relationship between the DNA ploidy pattern of patients and their prognosis. In this study we aimed to evaluate these two potential indicators of constitutive drug resistance in human colorectal tumours. We employed a method to quantify simultaneously, on a per cell basis, mdr gene expression (using the C219 monoclonal antibody for P-glycoprotein) and nuclear DNA content with high-resolution bivariate flow cytometry. The study was performed on a human colon-carcinoma-derived cell line (LoVo) and its doxorubicin-resistant variant (LoVo/Dx) and on tumour samples and adjacent normal mucosa from 35 untreated patients with colon cancer. The P-glycoprotein was found in both LoVo and LoVo/Dx cells with levels slightly lower in the parental than in the resistant subline (P, NS). A multi-drug-resistant specific probe for mRNA expression and Western blot assay confirmed the specificity of p170 expression. All of the colon cancer with unimodal diploid DNA distribution and all the normal colonic mucosa samples showed P-glycoprotein expression, without a statistically significant difference in median values between tumours and normal samples. Tumours with bimodal DNA distribution showed median values of P-glycoprotein expression of their hyperdiploid cell clones significantly higher than those of their diploid clones and of the tumours with unimodal DNA distribution (P less than 0.005). Our results show the feasibility of bivariate flow-cytometric analysis of P-glycoprotein expression and DNA content on clinical material and support the hypothesis that the MDR phenotype and DNA ploidy together may influence the biological behaviour of colon cancer in vivo.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

HER-2/neu oncogene expression and DNA ploidy in normal human kidney and renal cell carcinoma.

Using flow cytometry (FCM), we have investigated both the DNA content (stained with propidium iodide) and HER-2/neu oncogene expression (revealed by means of an anti-HER-2/neu monoclonal antibody) in neoplastic and non-neoplastic kidney samples from 20 patients with renal cell carcinoma. All the non-neoplastic samples and 15/20 (75%) renal cell cancers showed diploid modal DNA content while the remaining 5 neoplastic sample (25%) showed both diploid and hyperdiploid cell populations. In normal kidney the level of HER-2/neu oncoprotein was low (median fluorescence values in arbitrary units = 7.5 AU, range: 4-10 AU). In diploid renal cancers the level of HER-2/neu was slightly increased (median fluorescence values = 20 AU, range: 9.5-30 AU) (p < .005). The relationship of HER-2/neu expression to the cell cycle in these tumor samples is not clear since most of the cells express the antigen in all phases of the cell cycle. On the other hand, there is an association between HER-2/neu expression and abnormal DNA content suggesting that aneuploid pattern may be biologically related to overexpression of the HER-2/neu gene.

Aneuploidy↗

Prognostic significance of nuclear DNA content in human neuroepithelial tumors.

The relationship between survival and flow cytometric DNA-ploidy and other prognostic factors such as histological subtype, anatomical tumor site, patient sex and age was investigated in 153 patients with intracranial neuroepithelial tumors who underwent surgical treatment. We found a trend toward poorer survival from anaplastic astrocytomas and glioblastomas with respect to low-grade (I and II) astrocytomas (which did not differ significantly); accordingly, patients were grouped into these 3 histologic subgroups. Thirty-seven of the 153 tumors (24.2%) were aneuploid with a median DNA-index (DI) of 1.3 (range: 1.2-2.0). DNA-ploidy correlated with histology, since anaplastic astrocytomas and glioblastomas were significantly (p = 0.041) more frequently aneuploid (around 30%) than low-grade astrocytomas (around 10%). Patients with DNA-aneuploid tumors (i.e., with DI not equal to 1.00) survived for a shorter time (31.4 weeks) than patients with DNA diploid tumors (75.1 weeks) (p less than 0.001). This difference was confirmed by Cox's multivariate analysis. Aneuploid tumors were associated with a poorer survival (p = .0002) when compared with diploid tumors, resulting in a relative risk point estimate (RR) of 2.41, 95% confidence interval (Cl) = 1.55-3.74. Histological subtype was also significantly associated with survival (p less than 0.0001), with RRs of 2.09, 95% Cl = 1.13-3.86 and 3.59, 95% Cl = 1.96-6.59 for anaplastic astrocytomas and glioblastomas, respectively, compared to low-grade astrocytomas. We therefore suggest that the flow cytometric measurement of DNA-ploidy has relevant significance in predicting survival in patients treated for intracranial neuroepithelial tumors.

Age Factors↗

Flow cytometric DNA index in the prognosis of colorectal cancer.

The authors investigated the relationship between flow cytometric DNA index (DI, defined as the ratio of the DNA content of malignant cells to that of normal cells) and other prognostic factors (grade and stage, anatomical site, age and sex) with the survival of 115 patients with colorectal cancer. Multiple biopsy specimens from 62 patients were taken during colonoscopy before surgery. Additional samples from 53 patients were obtained from paraffin-embedded material. All patients were treated with surgery only. Fresh-frozen material gave higher incidence of DNA aneuploidy than paraffin-embedded material (79% versus 41%). The patients with DNA diploid tumors (DI = 1) had a better overall survival than those with DNA aneuploid tumors (DI = 1). Among DNA aneuploid tumors, those with DI greater than 1.2 (excluding DI = 2) were worse than those with DI = 1.2 (excluding DI = 1) and DI = 2. Cox's regression analysis showed that pathologic stage was more important for prognosis than DNA index, whereas age, sex, histologic grade, and anatomic site were removed from the analysis as not relevant for prognosis. Relative risk of death (RR), in reference to patients with DI = 1 and Stages A + B (RR = 1), were RR = 1.8 for patients with carcinomas with Stage C. RR = 2.7 for patients with carcinomas with DNA near-diploid and DNA tetraploid tumors. RR = 3.5 for those with DI greater than 1.2 (excluding DI = 2), and RR = 8.0 for those with Stage D. These data indicate that flow cytometrically evaluated DI values have a relevant independent power for predicting the clinical outcome of colorectal cancer patients.

Aged↗

A study on the biological behavior of human brain tumors. Part I. Arachidonic acid metabolism and DNA content.

The study of proliferative characteristics and biochemical aspects seem to be of great importance in order to define brain neoplastic behavior. The purpose of this study is to verify the existence of any possible correlation between Arachidonic Acid (AA) metabolism and proliferative characteristics in 30 meningiomas and 30 neuroepithelial tumors. The most represented metabolite in neuroepithelial tumors is TxB2, while 6-Keto-PGF1 alpha is the lowest represented product. Unimodal DNA distribution was observed in 66% of neuroepithelial tumors and in 87% of meningiomas. Aneuploidy was more frequent in glioblastomas and anaplastic meningiomas as previously reported; AA overall synthesis capacity and profile were similar between unimodal and bimodal cases of neuroepithelial tumors. Total AA metabolite, as well as TxB2 and PGD2, synthesis capacity are significantly higher in cases with S-phase cell percentage greater than or equal to 3% than in cases with S-phase % less than 3%. Total production of AA metabolites via the cyclooxygenase pathway is significantly higher in meningiomas with bimodal DNA distribution than in cases with unimodal DNA content; when considering S-phase cell percentage, similarly to what observed in neuroepithelial tumors, meningiomas with S% greater than 3% shows a significantly higher overall synthesis capacity for AA. AA metabolism capacity well correlates with proliferative patterns in neuroepithelial tumors: the relationship depends preferentially on TxB2 and PGD2 synthesis capacity. In cases of meningiomas, the amount of AA metabolites seem to be related to DNA content and proliferative activity when anaplastic features are histologically demonstrated.

Aneuploidy↗

Interferon alpha-2b in the long-term treatment of essential thrombocythemia.

We treated 35 patients affected with essential thrombocythemia (ET) with interferon (IFN) alpha-2b. Our treatment scheme consisted of (a) a 6-month induction phase and (b) a continuous maintenance phase. During the induction phase, our results showed that using 21 million units (mu) of IFN weekly platelet counts fell below 600 x 10(9)/1 in about 90% of patients. These data demonstrate that well-tolerated doses of IFN can rapidly correct excessive thrombocytosis. During the continuous maintenance phase, 61% of patients required 3 mu three times a week, 15% once a week, and 24% daily. Thus the minimal IFN doses able to maintain platelet count below 600 x 10(9)/l varied between 3 and 21 mu per week. During long-term treatment, subjective side effects were tolerable, especially using 3 mu three times a week. We conclude that IFN alpha-2b is an effective drug in the long-term treatment of ET.

Adult↗

Cranial irradiation and cerebrospinal fluid levels of 6-mercaptopurine in children with acute leukemia.

We measured 6-mercaptopurine levels in the cerebrospinal fluid and plasma of 15 children undergoing treatment for acute leukemia. Plasma and cerebrospinal fluid samples obtained by lumbar puncture were collected before, during, and after cranial irradiation in order to evaluate a possible change in blood-brain barrier permeability to orally administered 6-mercaptopurine. Considerable interpatient variability has been observed in both plasma and cerebrospinal fluid 6-mercaptopurine levels. No statistical differences in the 6-mercaptopurine cerebrospinal fluid levels under the three different conditions could be detected. Our data suggest that cranial irradiation does not significantly influence the cerebrospinal fluid levels.

Administration, Oral↗

Proliferating cell nuclear antigen (PCNA)/cyclin expression during the cell cycle in normal and leukemic cells.

Bivariate flow cytometric analysis of the cell proliferation-associated nuclear protein, identified as the "proliferating cell nuclear antigen" (PCNA)/cyclin and of nuclear DNA content, was performed in quiescent and mitogen-stimulated human peripheral blood lymphocytes, in EUE (human embryonic epithelium) cells, before and after a long-term exposure to a hypertonic (HT) medium, in 4 human leukemic cell lines and in fresh bone marrow (BM) cells from 10 patients with untreated acute non-lymphoblastic leukemia (ANLL). The PCNA/cyclin was detected using both an autoantibody extracted from sera of systemic lupus erythematosus patients and the recently produced mouse monoclonal antibody (MoAb) IgG, named 19F4. The distribution of cells in the different phases of the cycle and the percentage of S-phase cells were obtained in duplicate samples, by DNA flow cytometry (FCM) and by dual parameter FCM of DNA content and bromodeoxyuridine (BUDR) incorporation. In all cell types, the non-specific cytoplasmic background fluorescence was significantly lower with the MoAb compared to that obtained with the polyclonal Ab. The percentage of PCNA-positive cells (both with the autoantibody and the 19F4 MoAb) was always higher than that of S-phase cells by DNA FCM and of BUDR-labeled cells. The pattern of PCNA-expression in both normal proliferating cells and acute leukemia cells, showed that most G0/G1 cells did not express significant amounts of PCNA; an increase in PCNA immunofluorescence was found in late G1 cells, and further increases were observed in S- and G2-M phase cells. PCNA/cyclin, as revealed both with autoantibodies and with the 19F4 MoAb, is associated with all actively or potentially dividing (i.e. G1, S and G2-M) cells thus identifying the proliferative cellular compartment. Combined with the use of multiparameter FCM techniques, the PCNA immunolocalization offers a useful tool to study cell kinetics in normal and leukemic human cell populations.

Antibodies, Monoclonal↗