[Drug resistance genes]

Among the different mechanisms of multidrug resistance, the overexpression of the mdr1 gene has been actively investigated during the last 5 years. This gene encodes a 170 kDa protein, named P-gp, a member of a transporter superfamily, the ABC (ATP Binding Cassette) proteins. P-gp actively expels out of the tumoral cell different drugs like anthracyclins, vinca alkaloids, epipodophyllotoxins. The involvement of mdr1 gene in clinical drug resistance is now demonstrated, and several trials using P-gp modulators and chemotherapy are going on in resisting tumors. Other intrinsic drug resistance mechanisms, such as increase of intracellular glutathione content or decrease of topoisomerase activity, could be involved in clinical drug resistance.

In vitro effect of P-glycoprotein (P-gp) modulators on drug sensitivity of leukemic progenitors (CFU-L) in acute myelogenous leukemia (AML)

Cyclosporine A (CyA), a potent reversant of multidrug resistance (mdr), was studied for its effects on the sensitivity of leukemic progenitors (leukemia colony-forming units, CFU-L) to daunorubicin (DNR) and mitoxantrone. CyA was first compared to verapamil and cefoperazone for reversion of mdr in the mdr1+ cell line K562/DOX. A dramatic increase of sensitivity to 10(-6) M DNR was noted with CyA (0.5 and 1 microgram/ml) and verapamil (1 and 5 micrograms/ml), but not for cefoperazone (0.3 and 0.6 mg/ml). The sensitivity of K562/DOX to 10(-6) M mitoxantrone was also slightly enhanced by CyA. The change in CFU-L drug sensitivity in the presence of CyA was then tested in 12 relapsing/resisting patients and in 3 untreated patients with acute myelogenous leukemia (AML). No change in CFU-L sensitivity to DNR was noted, despite the presence of a subset of P-glycoprotein positive (P-gp+) cells in three out of the ten evaluable cases. Among the six evaluable cases tested with mitoxantrone and CyA, an increase of 50% in CFU-L sensitivity to mitoxantrone was noted in one (of three) P-gp+ patient. These data suggest that the CFU-L in AML rarely expressed the P-gp and that other mechanisms of drug resistance could be involved in AML.

[Caustic stenoses of the esophagus]

Oesophageal stenosis is a frequent complication of caustic burns, especially when deep injuries are present, due to the presence of scar tissue. After the treatment of initial complications and after an initial endoscopic evaluation, a few preventive measures can be decided to protect the upper part of the gastrointestinal tract. These measures include complete parenteral nutrition for some, and calibrating nasogastric tube for others; corticosteroid treatment is discussed. When stenosis is present, endoscopic dilatations can be performed. If they failed or instead of them, surgical replacement can be proposed with gastro or coloplasty. Resection of burned oesophagus prevents the risk of mucocele or cancer.

[Ingestion of caustics by children. Report of 23 deep lesions. Therapeutic attitude and long-term results]

In children, 23 caustic injuries of oesophagus with deep lesions (second or third degree of burn) were treated in pediatric ENT department (Pr ANDRIEU--Rouen) during a 19 years long period. Endoscopy in emergency, nasogastric tube for stent and repeated dilatations were the bases of the treatment. 14 second degree burns and 7 third degree burns were complicated of 9 stenosis and one death. The mean duration of total treatment was 43 months. The mean number of dilatations was 38 months. 4 stenosis were definitely cured. 8 children had normal feeding. Mean following was 8 years with good long term results.

Enhancement of anti-neoplastic activity of cytosine arabinoside against human HL-60 myeloid leukemic cells by 3-deazauridine

Drug resistance is one of the major reasons for failure of chemotherapy of acute leukemia with cytosine arabinoside (ARA-C). In order to overcome this problem we have investigated the interaction of ARA-C with 3-deazauridine (3-DU) against HL-60 myeloid leukemic cells. 3-DU is an interesting agent to use in combination with ARA-C, since drug-resistant cells that are deficient in deoxycytidine kinase are very sensitive to this uridine analogue. We have observed that for both short and long drug exposure there was a potent synergistic interaction between ARA-C and 3-DU with respect to their cytotoxic effects on HL-60 leukemic cells. This synergy could be explained by an increased cellular uptake of ARA-C to ARA-CTP by the leukemic cells in the presence of 3-DU, due to the reduction in the pool of dCTP produced by this latter analogue. Since dCTP is a potent feedback inhibitor of the phosphorylation of ARA-C by deoxycytidine kinase, the reduction in the dCTP produced by 3-DU results in an increased rate of phosphorylation of the arabinosyl analogue. Our results suggest that ARA-C and 3-DU may be an interesting drug combination to circumvent drug resistance in the chemotherapy of acute leukemia.

Multidrug resistance (mdr1) gene expression in adult acute leukemias: correlations with treatment outcome and in vitro drug sensitivity

Resistance to multiple chemotherapeutic agents has been related to the production of P-glycoprotein, a trans-membrane drug efflux pump that is encoded by the multidrug resistance (MDR) gene mdr1. To investigate whether mdr1 could be involved in clinical resistance to chemotherapy in acute leukemias, we have analyzed retrospectively the RNA from adult acute leukemia cells by slot-blot hybridization with a human mdr1 probe. Units of mdr1 expression were defined by reference to drug-sensitive human sarcoma and K562 leukemia cell lines (1 U) and the highly resistant doxorubicin selected leukemia cells K562/R7 (50 U). We studied 41 adult patients with acute leukemias: 5 acute lymphoblastic leukemias, 23 acute myeloid leukemias, and 13 secondary leukemias or blast crisis of chronic myelogenous leukemia. Expression of 10 U or more of mdr1 was found in 6 of 31 (19%) leukemias at diagnosis, versus 5 of 10 (50%) after relapse from therapy, P = .06. The complete remission rate and in vitro sensitivity to daunorubicin were both correlated with low expression (1 U, v 2 U or more) of mdr1. Among 36 evaluable attempts to induce remission, the complete remission rate was 67% (8 of 12) for patients with undetectable or minimal mdr1 expression (1 U), versus 29% (7 of 24) in patients with 2 U or more of expression, P = .03. In vitro resistance to daunorubicin or other MDR-related drugs was associated with expression of 2 U or more of mdr1 in 11 of 11 cases, while specimens that were sensitive to these agents were negative for mdr1 expression in 5 of 11 cases, P = .03. These data suggest that mdr1 expression contributes to chemoresistance in acute leukemia. Determination of mdr1 gene expression may be useful in designing therapy for patients with leukemia.

Effect of in vivo therapy with a CD8 monoclonal antibody on delayed engraftment after autologous bone marrow transplantation

Very long delay to engraftment (or non-engraftment) was observed in eight patients presenting common immunological features, i.e. excess of blood and bone marrow lymphocytes coexpressing CD8 and CD57 (HNK1) antigens. They were therefore treated by CD8 immunotherapy. Such treatment induced a complete clearance of CD8+, CD57+ cells from the blood and bone marrow in five cases, a partial clearance in one, the absence of clearance in one and a modulation in the last case. No toxic side effects were observed. Platelet recovery was observed in only two patients, but long-lasting granulocyte recovery was seen in six of the cases from day 6 to day 30 after the beginning of CD8 infusion (median = 17 days).

Epidemic Pseudomonas aeruginosa serotype O16 bacteremia in hematology-oncology patients

From 1 August 1978 through 31 December 1982, 98 hematology-oncology patients had positive cultures for Pseudomonas aeruginosa serotype O16; 22 of these patients developed bacteremia, and this bacteremia was associated with the occurrence of extensive perineal cellulitis in 10 patients (45.5%). Seventeen bacteremic patients died. The epidemic strain differed from other P. aeruginosa organisms isolated at the hospital by its resistance to all antibiotics available at that time (ticarcillin, piperacillin, azlocillin, tobramycin, ceftizoxime, ceftriaxone, moxalactam, ceftazidime, and fosfomycin). Univariate analysis showed the following factors to be significantly associated with P. aeruginosa O16 bacteremia: the severity of granulocytopenia at the time of the bacteremia, more days with fever, the administration of ticarcillin or an aminoglycoside, the receipt of a greater number of antimicrobial agents for a longer period of time before documentation of the bacteremia, and the occurrence of cellulitis. Logistic regression analysis showed that duration of fever, duration of bacteremia, and the number of antimicrobial agents administered before documentation of the bacteremia were the best predictors of P. aeruginosa O16 bacteremia. In a prospective study of the acquisition of P. aeruginosa by hematology-oncology patients, 1,149 specimens (throat and rectal swabs) from 270 patients and 201 specimens from their washbasin drains were collected. On only three occasions was the epidemic strain isolated from both the patient and his or her washbasin, but in each case the colonization of the patient preceded the isolation of the strain from the washbasin. The transmission of any P. aeruginosa organism from washbasin drain to patient could not be documented. Contact isolation precautions from the Centers for Disease Control were used for all hematology-oncology patients colonized or infected with P. aeruginosa after 7 January 1983. No case of P. aeruginosa O16 bacteremia has occurred at Hotel Dieu since July 1984.

In vitro sensitivity of normal and leukemic myeloid clonogenic cells to hyperthermia: absence of selective effect

The in vitro heat sensitivity of myeloid clonogenic cells was tested in 22 normal marrows (granulo-monocytic progenitors) and in 40 marrows of patients with acute myelogenous leukemia (leukemic progenitors). Cells were treated for 1 h at 42 degrees, 43 degrees, 44 degrees, or 45 degrees C prior to plating. A temperature-dependent inhibition of growth was seen without a selective effect on the two kinds of progenitors. Because these two kinds of progenitors have the same heat sensitivity, hyperthermia should not be used alone as a technique for in vitro depletion of residual myeloid leukemic cells.

Comparison of in vitro inhibition of etoposide (VP16) on leukemic and normal myeloid, erythroid clonogenic cells

We have compared in various clonogenic assays the in vitro sensitivity to etoposide (VP16) of 1) human leukemic precursors (leukemia colony-forming units; L-CFU), 2) normal erythroid progenitors (erythroid burst-forming units; BFU-E, and 3) normal committed myeloid progenitors (granulocyte-macrophage colony-forming units; CFU-GM and more primitive hemopoietic precursors (PPC) that adhere to cultured marrow stromal cells. Bone marrow samples were obtained from 15 normal subjects and 16 leukemic patients: 9 in the acute phase of acute nonlymphoblastic leukemia (ANLL) and 7 in complete remission. VP16 was tested at concentrations ranging from 10(-8) to 10(-3) M. The median recoveries at 10(-3) M VP16 were respectively 0%, 0.5%, 0%, and 0% for leukemic progenitors, CFU-GM from leukemic patients in complete remission, normal CFU-GM, and BFU-E, and 23% for PPC. This indicates that CFU-GM, BFU-E, and L-CFU are highly sensitive to VP16, whereas PPC, more primitive myeloid precursors, are spared. These results suggest that VP16 may be used as an "ex vivo" purging agent for autologous bone marrow.

Selective reinnervation of the abductor and adductor muscles of the canine larynx after recurrent nerve paralysis

Functional rehabilitation of the larynx after unilateral vocal cord paralysis was attempted in the dog by selective reinnervation of the laryngeal muscles. The intralaryngeal branches of the right recurrent nerve were dissected. The adductor branch was anastomosed with the ansa cervicalis; the abductor branch was anastomosed with the trunk of the phrenic nerve either within the larynx or through the recurrent nerve, the adductor branch of which was sectioned. Results could be analyzed in seven dogs: mobility of the vocal cord was checked, and electromyography, stimulation of the nerves, and histologic studies were performed. Functional reinnervation of both the adductor and abductor muscles was obtained in only one case, with good abduction. Adduction was recorded in five cases. False-positive results emphasize the necessity of collecting several types of data before concluding that functional reinnervation has been accomplished. The reliability of the procedure can and must be improved.

Multivariate analysis of prognostic factors in acute myeloid leukemia: value of clonogenic leukemic cell properties

The initial clinical and biological parameters, including clonogenic leukemic cell (CFU-L) assay, were reviewed for their prognostic significance in a cohort of 188 adult patients with newly diagnosed untreated acute myeloid leukemia (AML). Almost all patients received induction therapy with daunorubicin (DNR) and cytarabine (Ara-C) according to the European Organization for Research and Treatment of Cancer (EORTC) AML 5 to AML 9 trials. Bone marrow samples from 116 representative patients were obtained for CFU-L assay with an efficiency percentage of 89.6%; 76 patients had a measurement of the CFU-L self-renewal capacity (second plating efficiency [PE2]) and 91 patients had CFU-L inhibition test after exposure to DNR and/or Ara-C. The prognostic significance of parameters such as age, hematological antecedent, WBC count, liver enlargement, and Auer rods is confirmed in the present study. Moreover, high platelet and polymorphonuclear counts appeared to be related to resistance to induction course. However, through multivariate analysis, CFU-L sensitivity to drugs and self-renewal capacity appeared to be major independent prognostic factors in AML. A low CFU-L inhibition in the presence of the DNR and Ara-C combination correlates with a poorer complete remission (CR) rate, but not with CR duration. Patients with the lower PE2 values experienced both higher CR rate and longer CR duration. The practical interest of CFU-L study remains to be defined but, at least, PE2 measurement could be considered in the future as a major variable in determining therapeutic aggressiveness.

In vitro sensitivity of clonogenic cells in resisting and relapsing patients with acute myelogenous leukaemia

The evolution of in vitro bone marrow clonogenic leukaemic cells (CFU-L) drug sensitivity was studied in 23 patients with acute myeloid leukaemia treated with anthracycline and cytosine arbinoside (ara-C). In 12 patients tested before and after first induction treatment failure (interval: 6 +/- 4 weeks), the sensitivity remained stable for daunorubicin and showed little variation for ara-C. Among eleven patients tested before treatment and at first relapse (interval: 13 +/- 7 months), in vitro CFU-L sensitivity revealed no correlation between the two measurements, and a trend in decreased sensitivity to daunorubicin and ara-C. These findings suggest that induction failures could be related to factors other than simple selection of a resistant CFU-L subclone.

[Antibiotic therapy protocol using ceftazidime 3g/day alone or in combination with vancomycin or amikacin. In febrile episodes in neutropenic patients]

In a preliminary study of 21 febrile episodes in neutropenic patients ceftazidime used as empirical treatment in doses of 3 grams per day succeeded in controlling fever in 74 per cent of the cases. Laboratory studies performed in patients with Gram-negative septicaemia showed clinically effective plasma concentrations of the antibiotic. A trial of ceftazidime (3 g/day) administered alone or combined with amikacin or vancomycin is currently in progress in two medical centres. No statistically significant conclusions could be reached from an intermediate study.

Detection of residual disease in acute myeloid leukemia using light density gradients and culture assay

For monitoring the effect of chemotherapy in acute myeloid leukemia (AML), we attempt to detect minimal numbers of AML clonogenic cells (CFU-L) during remission using light density gradients combined with PHA-LCM methyl cellulose assay. Fifteen patients in complete remission (CR) of AML were studied: 8 patients with Auer Rods (AR+), and 7 without Auer Rods (AR-). The cluster/colonies ratio and the granulocytic maturation of cells from pooled colonies were not significantly different whatever the density cut used (1077, 1062 or 1059). In all the AR+ patients, few AR+ cells (.06% +/- .03) were observed in bone marrow cultures during remission, without differences between density gradients, but not before plating. These AR+ cells were not found in culture of AR- patient bone marrows nor in normal marrows. The serial studies performed in 6 patients (4 AR+, 2 AR-) were not contributive for relapse prediction. In 2 cases, the second examination failed to detect AR+ cells: one was performed after an autologous bone marrow transplantation and the other in a patient with prolonged CR (54+ months). A quantitative analysis of residual CFU-L with our technique requires a cytological examination of each colony, that is very time consuming and limits its routine use.

[Culture of clonogenic stem cells in human acute myeloid leukemia]

The properties of leukaemic progenitor cells can be evaluated from cultures of fresh clonogenic cells in a semi-solid medium. The major obstacle is the lack of selectivity of stimulating growth factors, which requires constant verification that the colonies obtained are made up of leukaemic cells. The in vitro sensitivity of leukaemic progenitors to cytostatic drugs is one of the best prognostic factors of response to treatment, and studies are in progress to determine the most appropriate multiple chemotherapeutic regimen according to these in vitro tests in patients who failed to respond to a first conventional therapy.

In vitro depletion of clonogenic cells in adult acute lymphoblastic leukemia with a CD10 (anti-cALLA) monoclonal antibody

A semi-solid medium colony assay was used in common acute lymphoblastic leukemia (cALL) to test growth inhibition of leukemic progenitors (CFU-L) after exposure to monoclonal antibodies (MoAbs) directed against CD10 and CD9 antigens. Peripheral or bone marrow cells from 15 patients were plated after exposure to various concentrations of ALB2, a CD10 cytotoxic MoAb, followed by complement lysis. CFU-L inhibition was complete (no residual colony) in 5 cases (33%), marked (greater than or equal to 95%) in 4 cases (27%), but only moderate (64% +/- 28) in 6 cases (40%). This inhibition was not related to the percentage of cALLA positive cells before exposure to MoAb. In addition, cells of 5 patients were exposed to BA1 (CD24) + complement. In these cases, the proportion of CFU-L inhibition was equal to or higher than with ALB2. In 3 cases, cells were exposed to an association of ALB2 and SB4 (CD19) MoAbs followed by complement lysis, with a marked inhibition (greater than or equal to 99%) in 2/3 cases. These observations give supplementary support to the use of several MoAbs directed against various antigens present at early stages of B differentiation.

Prognostic value of in vitro uptake and retention of cytosine arabinoside in acute myelogenous leukemia

In vitro uptake and retention of 3H-cytosine arabinoside (ara-C) was studied in 68 acute myelogenous leukemia (AML) patients (ten were studied twice) treated with a regimen containing conventional (54 patients) or high doses (24) of ara-C. Drug uptake and retention after four hours were measured following 30 minutes exposure to 1 and 50 micrograms/mL of ara-C. A good correlation was observed between high uptake in the acid soluble (AS) fraction (P less than .01), or high retention in the acid insoluble (Al) fraction (P less than .03) of 1 microgram, but not 50 micrograms, of the drug and obtainment of complete remission (CR) in patients treated with conventional doses of ara-C. Patients with a high percentage of ara-C retained in the AS fraction (greater than 26%) have a significantly longer CR duration than patients with a lower level of retention (P less than .02). In 17 patients who achieved a CR in spite of a low tritiated ara-C uptake, the clonogenic leukemic (CFU-L) cells were especially sensitive to drugs (15 of 17 v three of 11 among resisting patients).

Cytosine arabinoside for induction, salvage, and consolidation therapy of adult acute lymphoblastic leukemia

During A-ALL induction treatment, HD-ara-C (2.5 g/m2 IV, day 1), does not produce any beneficial effect, whereas the hematologic toxicity is increased. A 3-month consolidation phase comprising intermittent MTX, ara-C and 6-TG is not significantly affecting either DFI or survival in A-ALL. The association of HD-ara-C and m-AMSA appears to be a promising salvage therapy for the 20% A-ALL refractory to first induction therapy. The quality of autologous bone marrow graft, harvested after HD-ara-C, seems to be impaired as suggested by a delayed recovery of PMN and platelets. HD-ara-C (3 g/m2 X N) given the days before cyclophosphamide and TBI as conditioning treatment for BMT does not seem to induce prohibitory additional toxicity. Whether HD-ara-C was given four to six times or eight to 12 times gave no significant difference in early toxicity.

Prognostic value of clonogenic assay for induction and duration of complete remission in acute myelogenous leukemia

The validity of an in vitro clonogenic drug sensitivity assay to predict the induction and the duration of complete remission was evaluated in a group of 81 patients with acute myelogenous leukemia treated with chemotherapy including an anthracycline drug (daunorubicin or adriamycin) and cytosine arabinoside (Ara-C). The inhibition of bone marrow clonogenic leukemic cells by in vitro exposure to anthracyclines 10(-5) and 10(-6) M, Ara-C 10(-5) M, and daunorubicin 10(-6) M + Ara-C 10(-7) M was significantly correlated with the achievement of a complete remission, but not with the duration of remission. A high second plating efficiency was correlated with short duration of complete remission, reflecting the poor prognosis of a high self-renewal capacity.

[In vitro inhibition of granulopoiesis by beta-lactam antibiotics. Comparison of piperacillin, mezlocillin, ceftriaxone and ceftazidime]

The mechanism of neutropenia induced by beta-lactam antibiotics was explored by studying the action of these drugs on granulopoiesis in vitro. Normal bone marrows were cultivated in the presence of increasing concentrations of piperacillin (10 marrows), mezlocillin, ceftriaxone and ceftazidime (5 marrows each) in order to find out whether these antibiotics exhibited toxicity to granulocyte-monocyte precursors. A dose-dependent inhibition of granulopoiesis was found in all cases. When the doses used were equivalent to maximum plasma concentrations in vivo, inhibition was minimal with piperacillin and mezlocillin and much more pronounced with the cephalosporins. This dose-dependent inhibition suggests that toxicity is involved in the mechanism of neutropenia induced by beta-lactam antibiotics.

Persistence of bone marrow lymphocytosis after induction treatment in common acute lymphoblastic leukemia. Marker analysis and significance

In a series of 22 adult acute lymphoblastic leukemias expressing the common acute lymphoblastic leukemia antigen (cALLA +), eight had marrow lymphocytosis greater than 30% (43 +/- 12%) with disappearance of marrow lymphoblasts and correction of bone marrow insufficiency at the end of the induction treatment. Four of these patients were studied for the cALL antigen at this time and had persistence of this immunological marker (62 +/- 15% of the mononuclear bone marrow cells). The evolution of these patients suggests that these patients were not in complete remission and emphasizes the usefulness of cALLA determination in cases with borderline excess of marrow lymphocytes.

Peroxidase activity in circulating mast cells in blast crisis of chronic granulocytic leukemia. Comparative studies with basophils and cutaneous mast cells

Although the hematopoietic origin of mast cells is very probable, the cell from which they originate is still a matter of speculation. The description of "transitional basophil/mast cells" in myeloproliferative disorders has suggested a common origin for basophils and mast cells. In a case of mast cell transformation of chronic granulocytic leukemia, the authors have studied the morphology and peroxidase activity by three classical technics, of circulating mast cells and transitional "basophil/mast cells." These results were compared with those of blood and bone marrow basophils and those of cutaneous mast cells. In both mast cells and "transitional basophil/mast cells," peroxidase activity was revealed in the nuclear envelope, endoplasmic reticulum, and granules. This activity was detected in unfixed cells and in tannic acid-aldehyde-fixed cells but not in 1.25% glutaraldehyde-fixed cells, where the staining appeared only in the granules. The comparison of this activity with that of normal basophils and mast cells suggests that the proliferating cells in this case possess at the same time the peroxidase activity of basophils and mast cells.

Three cases of preleukemic myelodysplastic disorders with the same translocation t(1;3)

The same translocation, t(1;3)(p36;q21), was observed in three patients with a preleukemic syndrome presenting as a myelodysplastic disorder. It was the only chromosomal abnormality in two patients; and the third patient had 12p- and 15q- as additional abnormalities. The three cases evolved into acute nonlymphocytic leukemia.

Spontaneous remission in adult acute leukemia

A spontaneous complete remission of 34 months' duration was observed in an adult patient with acute myeloblastic leukemia. The remission occurred after a severe febrile pneumonia, which was treated with leukocyte transfusions. At relapse, chromosomal abnormalities reappeared slowly. Such spontaneous complete remissions, almost always associated with bacterial infections and blood transfusions, are extremely rare, and are usually of short duration. Previous cases are summarized, and the role of etiologic factors, including those related to the leukemic proliferation, are discussed.

Spontaneous remission in adult acute leukemia

A spontaneous complete remission of 34 months' duration was observed in an adult patient with acute myeloblastic leukemia. The remission occurred after a severe febrile pneumonia, which was treated with leukocyte transfusions. At relapse, chromosomal abnormalities reappeared slowly. Such spontaneous complete remissions, almost always associated with bacterial infections and blood transfusions, are extremely rare, and are usually of short duration. Previous cases are summarized, and the role of etiologic factors, including those related to the leukemic proliferation, are discussed.

[Combination of AMSA-high dose cytosine arabinoside in acute leukemia]

Forty patients with refractory and/or relapsing acute leukaemia were treated with AMSA (90-120 mg/sq m/day) for 5 days combined with high dose cytosine-arabinoside (HDARAC) (3 g/sq m/12 hours) during the first 2 days. Complete remission was obtained in 46% of the 26 cases of acute myelogenous leukaemia, and the complete remission rate was fair (44%) in the 20 patients refractory to conventional induction treatments. The results were less satisfactory in the few patients with other cytological types: there were 2 complete remissions in 10 patients with acute lymphoblastic leukaemia and none in 4 patients with blast crisis of chronic myelocytic leukaemia. Haematological toxicity was severe, and 6 patients died during the aplastic phase. No cardiac toxicity associated with AMSA was observed, nor did the ocular, cutaneous or cerebellar side-effects described after longer courses of HDARAC develop. Complete remissions were relatively short, and 11 of 14 remitters relapsed after 2 to 11 months (median 4 months). However, 3 remitters underwent allogenic bone marrow transplantation with 2 surviving. Another patient has a prolonged fourth complete remission with AMSA + HDARAC maintenance treatment. It is concluded that the AMSA-HDARAC combination seems to be one of the best salvage induction regimens in acute myelogenous leukaemia.

Flow cytometric analysis of pentakis(aziridino)thiatriazadiphosphorine oxide (SOAz)-induced changes in cell cycle progression of HeLa and HL-60 cells

The treatment of HeLa and HL-60 cells with various concentrations of pentakis(arizidino)thiatriazadiphosphorine oxide results in inhibition of growth and modification of cell cycle distribution. These phenomena were observed at 10(-4) M and 5 X 10(-5) M for HeLa cells and 10(-5) M and 5 X 10(-6) M for HL-60 cells. The estimation of DNA content by flow cytometry showed an important shift in the distribution of cycling cells with a striking arrest in G2 for both cell lines with a concomitant late S-phase accumulation for HeLa cells. Incubation of cells in drug-free medium 3 days after treatment did not show any change in DNA distribution, suggesting the irreversibility of drug action.

[Acute nonmyeloid leukemia in adults. Study of membrane antigens and terminal transferase. Diagnostic and prognostic value]

Between January, 1982 and April, 1983, 92 adult patients with acute leukaemia were investigated in our department. According to classical criteria (cytology and optical cytochemistry), 34 were classified as "non-myeloid". These were further tested with a panel of monoclonal antibodies against cell membrane, including ALB1-2 (anti-CALLA), ALB6 (anti-p24), ALB7-8-9 (BA1), OKT and HLA DR; they were also tested for E rosettes, Slg and terminal transferase (TDT). When all these markers but HLA DR were negative, patients were investigated for ultrastructural peroxidases which were found to be present in 2 cases. Among all non-myeloid leukaemias, 18 (56%) were CALLA-positive and TDT-positive acute lymphoblastic leukaemias (ALL), 2 (6%) were ALL T, 7 (22%) were CALLA-negative and TDT-positive ALL and 5 (16%) were acute leukaemias null for our markers, a phenomenon the significance of which is discussed. Patients with the CALLA-negative TDT-positive phenotype were peculiar with regard to age (mean: 50 years), female predominance, L2 cytological pattern according to the FAB classification, good prognosis (complete remission in 100% of the cases) and median survival (p less than 0,03).

DNA ligases in human leukemia

Following partial purification on sucrose gradient and/or phosphocellulose chromatography, DNA ligase was tested in peripheral white blood and bone marrow cells of nearly 100 patients with various kinds of leukemias, mainly acute leukemias. Terminal deoxynucleotidyl transferase (TdT) was tested in parallel. DNA ligase of acute myeloblastic leukemia (AML) was extracted with the same sedimentation coefficient (5.5S) on sucrose gradient, and eluted with the same KCl molarity (0.3 M) than the one extracted from normal lymphocytes. Acute lymphoblastic leukemias (ALL) were characterized by no detectable DNA ligase activity--in most T or non T-non B-ALL, or a low activity in pre-B and B (Burkitt type) ALL, with levels similar to the one observed in chronic lymphocytic leukemia (CLL). An inverse relationship was observed between DNA-ligase and TdT in ALL, ligase being undetectable in cells positive for TdT and being present in some T or non T-non B, and in all pre-B and B-ALL negative for TdT. AML and chronic myelocytic leukemia (CML) were characterized by a markedly higher DNA-ligase activity. This activity was higher in the most differentiated subtypes--M2, M3 and M4 subtypes of FAB classification--and in CML. Moreover a high degree of correlation was observed in AML between the DNA ligase activity and the S phase fraction measured by 3 H-thymidine autoradiography or flow cytophotometry on the total cell sampling. Besides their clinical interest, these results are discussed in relation with the role of DNA-ligase in DNA replication and repair.

In vitro culture of clonogenic leukaemic cells in acute myeloid leukaemia: growth pattern and drug sensitivity

Bone marrow from 43 of 45 AML patients grew leukaemic colonies in culture with a technique using methyl-cellulose semi-solid medium and stimulation with PHA-leucocyte conditioned medium. Plating efficiency was significantly greater in M4FAB subtypes than in M1 or M2. The presence of Auer rods in cultured cells and the existence of cytogenetic abnormalities in both fresh and cultured blast cells in one patient confirmed the leukaemic origin of these colonies. These clonogenic cells were closely related to the growth fraction, as demonstrated by a high suicide index and a linear correlation between percentage of bone marrow blasts in S phase and plating efficiency. In vitro CFU-L sensitivity to cytosine-arabinoside (ARA-C) and to adriamycin (ADR) was tested in 22 patients treated with these two drugs. In the group sensitive in vitro to ARA-C (10 patients), 70% entered complete remission. In the resistant group (12 patients), only 25% had complete remission while 75% had resistant disease. Eight of 14 patients sensitive to ADR in vitro achieved complete remission, while five were resistant to chemotherapy. On the other hand, six of eight patients resistant in vitro were resistant in vivo. When drug sensitivities to ARA-C and ADR were cumulated, an excellent in vitro to in vivo correlation was found when the patient was sensitive or resistant to both drugs in vitro.

High-dose cytarabine in acute leukemia: toxicity and pharmacokinetics

High-dose cytarabine (HDARA-C) at doses ranging from 1000 to 3000 mg/m2 administered as 30-min iv infusions was used in 12 patients with acute leukemia. HDARA-C toxicity was marked by nausea, vomiting, and somnolence; fever occurred in one patient. Myelosuppression was brief and reversible; the wbc count nadir occurred between Days 10 and 15 after treatment. In this study of a limited number of patients, no reliable conclusions could be drawn about antileukemic activity. However, (a) HDARA-C appeared to be a well-tolerated regimen in acute myeloblastic leukemia in complete remission; (b) a clear improvement was obtained in a patient with central nervous system leukemia; and (c) a sharp but transient decrease in peripheral blast cell counts was seen in two patients with acute myeloblastic leukemia. Cytarabine distribution was bi- or tri-compartmental; plasma final half-life was greater than 4 hrs in six patients. Pharmacokinetic parameters were not correlated with serum deoxycytidine deaminase activity. HDARA-C crosses the blood-brain barrier and may be useful in the prophylaxis against and treatment of central nervous system leukemia.

[Ultrastructural peroxidases and immunological markers in acute adult leukaemia: therapeutic applications (author's transl)]

In a retrospective study of 112 adult patients with acute leukaemia (AL), the percentage of undifferentiated leukaemia was reduced to almost 1% by an analysis of routine cytochemical reactions (PAS, peroxidase, esterases and esterase inhibition), B and T lymphocyte markers (IgS, E-rosettes, HuTLA) cAll antigen and ultrastructural detection of peroxidase activity (PO-ME). A simultaneous study of cALL antigen and PO-ME showed reciprocal exclusion of these markers, except in one case of mixed leukaemia. Therapeutically, the value of these tests lies in that patients with typical PAS reaction and cALL antigen consistently respond to vincristine- corticosteroid treatment, whereas patients without cALL and with PO-ME are frequently resistant to that combination of drugs.

[Early evaluation of therapeutic response in acute lymphoblastic leukaemia. A study of cytoreduction in blood and bone marrow (author's transl)]

Cytoreduction was evaluated during the first week of induction treatment in 29 adult patients with acute lymphoblastic leukaemia. In 25 patients a slope of decrement of circulating blasts between the 1st and 7th days of treatment could be drawn on a semilogarithmic scale. The fall of the medullary blast index was calculated in bone marrow obtained by aspiration in 17 cases and by aspiration plus biopsy in 11 cases. The diminution of circulating and medullary blasts was more pronounced in patients who achieved complete remission than in those who failed to respond (p less than 0.001), irrespective of the induction treatment. Early therapeutic cytoreduction, as measured by these simple mathematical methods, therefore has a bearing on the prognosis, and the induction treatment should be reinforced in cases where cytoreduction is insufficient.

Determination of ultrastructural peroxidases and immunologic membrane markers in the diagnosis of acute leukemias

Detection of membrane markers and ultrastructural peroxidase activity was carried out on the blasts of 16 apparently nonmyeloid adult acute leukemias. These patients were selected from 73 adult leukemic patients by the negativity of their routine cytochemical myeloid markers: i.e., myeloperoxidase, chloresterase activity, and Sudan Black B staining. B and T acute lymphoid leukemias (ALL) were excluded from the study. After concurrent testing from human T lymphocyte antigen (HuTLA), common ALL antigen (cALL), la-like antigens, and peroxidase activity at the electron microscopic level (POEM), only two patients remained undifferentiated (cALL-, POEM-). The other cases were classified as following : 6 common ALL (cALL+, POEM-), 1 pre-T-ALL (cALL+, HuTLA+, POEM-), 5 very poorly differentiated acute myelogenous leukemia (AML) (cALL-, POEM+), and 2 mixed leukemias (cALL+, POEM+). Terminal deoxynucleotidyl transferase activity (TdT) was measured in 7 cases and was found to be present at high levels in 4 cases of cALL and in the 2 cases of acute undifferentiated leukemias (AUL): it was absent in two cases of AML. Cytogenetic analysis had showed that 2 of the cALLs, 3 of the AMLs, and the 2 mixed leukemias were PH1+. We conclude that POEM detection is useful in apparently nonmyeloid leukemias with negative immunologic lymphoid markers, and that the existence of a Ph1 chromosome should be investigated, particularly in the unusual case of mixed (lymphoid-myeloid) acute leukemia.

In vitro sensitivity of CFU-L to cytosine arabinoside (Ara-C)

The in vitro sensitivity of leukemic colony-forming cells to Cytosine arabinoside (Ara-C) was assessed in acute myeloid leukemia, by means of a clonogenic assay using methyl-cellulose with phyto-hemagglutinin (PHA)-leukocyte conditioned medium. Bone marrow clonogenic cells were more sensitive to Ara-C than blood clonogenic cells. Also a continuous exposure to Ara-C induced a higher reduction of the leukemic colonies than one hour exposure. Patients were, according to the in vitro results, divided into 3 groups: eight patients had a dose-responsive curve for all the tested drug concentrations and were characterized by a marked sensitivity to the induction treatment combining Ara-C and Adriamycin. Three patients had a = 50% reduction of colonies with the 3 concentrations; two achieved complete remissions. Seven patients were in vitro insensitive to the drug; four of them had a relative or absolute resistance to the induction treatment.

PHA-induced blast colonies and kinetic parameters in acute myeloid leukemia

The in vitro leukemic colony-forming ability of 30 acute myeloid leukemias tested after PHA stimulation was analyzed by comparing the CFU-GM growth pattern, the myeloblast [3H]thymidine index and the response to treatment. PHA-induced leukemic colonies were obtained in 15 out of 30 cases. No correlation was found between the FAB classification, the CFU-GM growth pattern and the PHA-induced colony growth. A significant correlation was observed between PHA-induced colony growth and [3H]thymidine labeling index (p less than 0.001). A correction was also noted between the presence of leukemic growth and the failure of the induction treatment (p less than 0.02). The proliferation of the clonogenic blastic subpopulation selected by this technique seems to be linked to a poor prognosis.