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Biomedical subjects

G Mathe

Publications and source records attributed to G Mathe.

At least 19 recordsLinked to original sources
PubMed2001

Interaction of GM(1) glycolipid in phospholipid monolayers with wheat germ agglutinin: effect of phospholipidic environment and subphase.

Mixed monolayers of GM(1) glycolipid and stearoyl-oleoyl-phosphatidylcholine (SOPC) or dipalmitoyl-phosphatidycholine (DPPC) phospholipids were studied by surface pressure measurements. The effects induced by GM(1) on the mean molecular areas of mixtures and DPPC phase transition were followed for GM(1) concentrations ranging from 1 to 20 mol.%. Under our experimental conditions, one main parameter influencing the behavior of phospholipid-GM(1) monolayers is the ionic strength of the subphase. Mixed monolayers are in a more expanded state on buffer than on pure water. This could be due to a change of GM(1) orientation at the interface. The interaction of wheat germ agglutinin (WGA), a lectin recognizing specifically GM(1), with these monolayers was quantified in terms of the Gibbs equation. Specific WGA-GM(1) interactions are clearly reduced in the presence of DPPC as compared with SOPC, probably because of the higher packing density of these monolayers. Phospholipid-GM(1) monolayers could also undergo some rearrangements induced by WGA binding.

Binding Sites↗
PubMed1991

Elliptinium, norcantharidin and tetrachlordecaoxide in combined chemo-immunotherapy prolong the survival of Friend-virus-infected mice.

The association of several drugs with different target specificities has long been proven to be more efficient than one single agent in the treatment of cancer. This strategy might also be of benefit in the cure of retrovirus-induced diseases. The effectiveness of several drug combinations was evaluated on DBA/2 mice injected with Friend leukaemia virus (FLV). Elliptinium (ELP), a known chemotherapeutic agent with possible antiviral activity, was given in association with norcantharidin (NCTD) (shown previously to increase the cytotoxic potential of human lymphocytes) and/or in association with tetrachlordecaoxide (TCDO), which augments both humoral and cellular immune responses. ELP alone at a dose of 0.2 mg/kg in long-term treatment significantly increased the survival of mice infected by FLV. When ELP, TCDO (2 micrograms/kg) and NCTD (2 mg/kg) were given together, the survival time was prolonged 1.6 times and 2 times as compared to the group treated by ELP alone or to non-treated controls, respectively. Moreover, the combined treatment gave more effective inhibition of hepatomegaly than ELP alone, suggesting that this protocol might have an organ-specific effect and might suppress the leukaemogenesis induced by FLV in some erythropoietic organs. These results indicate that a chemotherapeutic agent (ELP) associated with two immunomodulatory substances (NCTD and TCDO) is more effective than chemotherapy alone in controlling retroviral infection and in the prolongation of survival. These data taken together suggest that the role of the two immunomodulatory agents might be to suppress the retroviral infection synergistically with ELP and enhance immune functions. Possible modes of action are discussed and are under investigation.

Adjuvants, Immunologic↗
PubMed1989

The prognostic implications of an immunological classification of acute lymphoblastic leukemia.

Thirty-one patients with newly diagnosed acute lymphoblastic leukemia were examined before receiving any treatment and their clinical and laboratory data were analyzed in order to determine the possible correlation between clinical presentation, morphologic sub-classes, cytochemical reactions, immunological phenotypes and cytogenetic findings. Each of the previous parameters and response to therapy were also examined for correlation. The analysis of clinical and laboratory characteristics of patients according to their immunological phenotype did not show any significant male sex bias, age distribution, hepatomegaly or splenomegaly at diagnosis. The analysis of clinical response of patients did not demonstrate any significant influence of sex, age, initial WBC count or the presence of a big tumor mass at diagnosis. There were no significant differences between our two major immunological subclasses Non-T CALLA+ ALL, and Pre-T ALL regarding proportions of patients in continuous remission, and relapse-free survival durations. The analysis of clinical and laboratory characteristics of patients on the basis of their chromosome categories did not show any significant sex bias, age distribution, initial WBC count, tumoral presentation or morphological subtypes at diagnosis, although there was an apparent male predominance in the pseudodiploid category and female predominance in the hyperdiploid category. Our results concerning the prognostic implication of CALLA were contradictory to those of several other investigators.

Adolescent↗
PubMed1988

CNS prophylaxis using a triple intrathecal drug therapy without cranial irradiation in acute lymphoblastic leukaemia.

After remission-induction chemotherapy in 31 patients with acute lymphoblastic leukaemia, patients immediately received CNS prophylaxis. Thirteen patients received triple intrathecal drug therapy, while 18 patients received intrathecal methotrexate and cranial irradiation; systematic chemotherapy was administered as well to both groups. Six patients developed CNS leukaemia during complete remission, 2 in the non-radiated patients and 4 in patients who had received cranial irradiation. Drug chemoprophylaxis may therefore substitute cranial radiotherapy when effective systemic regimens are used. Such CNS chemoprophylaxis will result in fewer, long-term CNS side-effects.

Adolescent↗
PubMed1987

Circannual rhythm in natural killer activity and mitogen responsiveness of murine splenocytes.

Seasonal variations were observed in murine splenic natural killer (NK) cell activity and also in murine lymphocyte responsiveness to mitogens, namely, concanavalin A, phytohemagglutinin, and lipopolysaccharide. The maximum and minimum splenic NK cell activities were observed in January-February and July-August, respectively. Conversely, maxima and minima of lymphoproliferative responses to all the three mitogens occurred in April-June and January-February, respectively. Such variations, when inferential statistics are used, appeared to be accounted for by circannual and other low-frequency (infradian) bioperiodicities. More specifically, the circannual rhythm in murine NK cell activity was demonstrated in data from a total of 356 mice collected over a period of 5 years. The various components of the immune system are characterized by a multifrequency time structure. The understanding of the organization of the immune system along the yearly scale may have bearings on that of the seasonal incidence of numerous infectious diseases and on the success/failure of immunotherapy.

Animals↗
PubMed1987

Circadian time dependence of murine tolerance for the alkylating agent peptichemio.

Since the extent of host toxicity of cytostatics is considerably affected by dosing time, a chronopharmacologic approach was undertaken for optimizing the therapeutic index of the alkylating agent, peptichemio (PTC). In 4 studies involving a total of 463 male B6D2F1 mice, a highly statistically significant circadian rhythm characterized murine tolerance for PTC (8 or 10 mg/kg/day i.v. X 3 days). Six circadian stages were explored (3, 7, 11, 15, 19 and 23 Hours After Light Onset--HALO). Day-40 survival rate varied between 20% (PTC at 3 HALO) and 55% (PTC at 15 HALO) (chi 2 = 16.7; P less than 0.01). In each study, body weight loss was maximal in mice injected with PTC at 3 HALO and minimal in those treated at 15 HALO (P less than 0.01). In a further study involving 96 male B6D2F1 mice, the toxicity of PTC on several target tissues (bone marrow, spleen, small bowel, colon, liver, kidney and lungs) was investigated by histology and leukocyte count as a function of drug dosing time. A circadian rhythm in the susceptibility of the bone marrow, the spleen and the intestinal tract was demonstrated. Optimal murine tolerance for PTC resulted from dosing it at 15 HALO, e.g. in the first half of the activity span.

Animals↗
PubMed1987

Abnormal proliferation of T-colony-forming cells from peripheral blood of patients with T-cell acute lymphoblastic leukaemias and lymphomas in complete remission: potential prognostic value.

Peripheral blood T-colony-forming cells (T-CFC) from most patients with T-cell acute lymphoblastic leukaemias (T-ALL) and T-cell non-Hodgkin's lymphomas (T-NHL), can proliferate in vitro in methylcellulose in the absence of added growth factors or mitogens. We now report that spontaneous T-cell colonies could also be obtained during complete remission of 13 out of 21 patients with T-ALL and T-NHL, but none of eight patients with common (pre-B) ALL (cALL). Colony cells were mainly E+T3+, with a variable expression of other T cell markers. Spontaneous T-CFC did not possess self-renewal capacity in the absence of added growth factors. Moreover, incubation of spontaneous colonies with colchicine yielded mitoses in only two out of seven patients, with one normal and one abnormal karyotype. In five patients tested, recombinant interleukin 2 (IL2) could also induce the proliferation of some T-CFC. Both spontaneous and IL2-induced colonies were inhibited by an anti-IL2 receptor monoclonal antibody, suggesting that interaction of IL2 with its receptor may be involved in the proliferation of some T-CFC from these patients. A study of 14 T-ALL patients tested during their first remission indicated that patients who developed no or few spontaneous colonies during their first remission (less than 20 colonies/10(5) mononuclear cells) seemed to relapse later and to have a significantly longer survival than patients with a high number of spontaneous colonies. These data suggest that the spontaneous proliferation capacity of T-CFC might be of prognostic value in the clinical evaluation of T-ALL.

Adolescent↗
PubMed1987

[Immunologic surveillance of liver transplant patients using monoclonal antibodies against lymphocyte subpopulations].

A precise immunological surveillance of liver graft recipients can allow the adaptation to each patient of an adequate immuno-suppressive treatment. In 11 liver-transplanted patients (7 primitive biliary cirrhoses, 2 post-hepatic cirrhoses, one bile duct atresia with one antitrypsin deficit) different lymphocyte subpopulations were tested before transplantation and at days 3, 5, 7, 15, 30, 60 and 120 after grafting using OKT3, OKT4, OKT8 (Orthoclone, France). In 6 patients presenting one or more rejections, the (T4+):(T8+) lymphocyte ratio was significantly increased during the days preceding rejection. In all cases, the (T4+):(T8+) ratio increase was linked to a (T4+) helper lymphocyte augmentation. In the 6 patients who did not present any rejection, the (T4+):(T8+) ratio did not increase at long term. A decrease of the (T4+):(T8+) ratio, along with an augmentation of (T8+) lymphocytes, was noticed at long term in patients free of chronic rejection. The evolution of T lymphocyte populations, followed using monoclonal antibodies and mainly the (T4+):(T8+) ratio, can provide a test for rejection predictability of for the prognosis of tolerance to liver allografts.

Antibodies, Monoclonal↗
PubMed1987

[Therapeutic trials of aclarubicin in previously treated acute leukemias and hematosarcomas].

In a phase I-II trial, 38 patients with acute myeloid leukemia (AML) were given single drug induction therapy with aclarubicin (ACM) according to two dosing schedules: treatment 1: 10 to 30 mg/m2/d to a maximum total dose of 300 mg/m2 or until development of unacceptable toxicity: treatment 2: 15 mg/m2/d in ten-day courses separated by ten-day intervals. Response rates were 15% with treatment 1 and 44% with treatment 2 (overall response rate 34%). Complete remission (CR) was achieved in 6 patients who had previously failed to respond to adriamycin (ADM). Toxicity was more frequent and more severe in those patients given more than 150 mg/m2 ACM per course. The main side effects were oropharyngeal mucositis and diarrhea. Three patients exhibited T wave inversion and one had an episode of auricular flutter. In a separate trial in 16 patients with AML we used cyclic chemotherapy combining ACM (20 mg/m2/d) and ARA-C (200 mg/m2/d) for seven consecutive days. Complete remission rate was 50%. Severe ventricular rhythm disorders were seen in two patients. In a phase I-II study, 19 patients with acute lymphoid leukemia (ALL) and 8 patients with non-Hodgkin lymphoma (NHL) were given ACM alone according to the regimen designated treatment 1 described above. Response rates were 11% (2/19) in ALL and 25% (2/8) in NHL. A review of the literature is presented in the discussion of the original trials reported herein.

Aclarubicin↗
PubMed1986

T-cell colony formation in patients with T-cell malignancies: growth factor requirements for in-vitro proliferation of peripheral blood T-cell colony-forming cells.

Peripheral blood T colony-forming cells (T-CFC) from patients with T-cell malignancies are capable of proliferation in methylcellulose, in the absence of added growth factors or mitogenic stimulation. We show here that based on the spontaneous plating efficiencies of their T-CFC, two groups of patients can be established: Group A (10 patients) with a high colony number (more than 100 colonies/10(5) seeded cells), and group B (12 patients) with less than 100 colonies/10(5) cells. The addition of interleukin 2-(IL2) containing PHA-leukocyte conditioned medium enhanced colony growth from group B but not group A patients. Moreover, both biochemically purified and recombinant IL2 induced the colony growth from group B but not group A patients without any other stimulation. In addition, a monoclonal antibody (moAb) against the IL2 receptor (IL2-R; anti-Tac) inhibited the spontaneous colony formation from T-CFC of both groups of patients. These observations strongly suggest that IL2-R are involved in the spontaneous colony growth of T-CFC. To determine whether IL2 is also involved in the spontaneous colony formation, media conditioned (LCM) by unstimulated leukemic cells were tested for IL2 activity. A constitutive release of IL2 was detected in LCM from only 2 out of 10 patients tested, and some of them were capable to inhibit thymidine incorporation by IL2-dependent cells cultured in the presence of highly purified IL2. However, most of these LCM contained a T-cell colony-promoting activity (TCPA) inducing colony formation from both normal resting and PHA-stimulated E+ clonogenic cells without added IL2 or mitogenic stimulation. TCPA-containing LCM induced the expression of functional IL2-R and IL2 release by normal resting lymphocytes. TCPA was constitutively released by blast-enriched cell fractions suggesting that it is released by the leukemic cells.

Antibodies, Monoclonal↗
PubMed1985

Mitoxantrone combined to vincristine, cyclophosphamide and fluorouracil in advanced breast cancer.

In our wide experience of treating advanced breast carcinoma with chemotherapy, the combination of doxorubicin (DOX), vincristine (VCR), cyclophosphamide (CPM) and fluorouracil (FU) gave a complete plus partial response rate of over 60%, with 100% alopecia and frequent cardiac toxicity depending on total dose. After the EORTC Clinical Screening Group phase II trial we have conducted an "expected difference method" comparative phase II trial using the combination DOX, VCR, CPM, FU and the combination of MTX (10mg/m2), VCR, CPM and FU on a population of 50 breast carcinoma patients similar to those taking part in the first study. The reasons for similarity of action will be presented and discussed.

Adult↗
PubMed1985

The effect of zinc on normal and neoplastic T-lymphocyte proliferation.

After 24-72 h of PHA-stimulation, T-cells expressed the transferrin receptor. This receptor facilitates zinc uptake. Zinc transferrin stimulated DNA synthesis in pre-activated or activated, but not in resting T-cells. The regulatory nuclear protein matrix fraction increased from 5 to 40% of the total nuclear protein material in lymphocytes simultaneously with the initiation of DNA synthesis. In contrast, optimal concentration (0.1-0.4 mM) of zinc salts induced a mitogenic response in transferrin-receptor negative resting, but not in PHA-activated or leukemic T-cells. Higher concentrations were toxic. These findings can explain earlier reports on the effect of zinc on immunocompetence in zinc deficient mice and enteropathic acrodermatitis as well as present findings of a normalization of the T-suppressor-cell number in immunosuppressed patients.

DNA Replication↗
PubMed1985

Circadian rhythm in tolerance of mice for the new anthracycline analog 4'-O-tetrahydropyranyl-adriamycin (THP).

A statistically significant circadian rhythm in tolerance of 226 male B6D2F1 mice synchronized with LD 12:12 for 4'-O-tetrahydropyranyl-adriamycin (THP) was demonstrated. Four intravenous dosages (18, 25, 32 and 40 mg/kg) and six different dosing times (3, 7, 10, 14, 19 and 23 hr after light onset-HALO) were compared. Survival rate, body weight loss and leukopenia depended on both the dose and time of injection. The overall survival rate varied between 83% (light-rest span) and 56% (dark-activity span) (chi2 = 17; d.f. = 2; P less than 0.001). Maximal body weight loss occurred 4-5 days after drug injection. Total leukocyte counts were determined on these days. Both body weight loss and leukopenia were reduced by approximately 100% in those mice injected in their late rest span (7-10 HALO) as compared to those treated in the middle of their activity span (19 HALO). Circadian rhythms in day-60 survival rate, body weight loss and leukopenia were statistically validated by cosinor analysis, with estimated peak times (acrophases) occurring respectively at 7:30, 9:20 and 8:40 HALO. Minor cardiac lesions consisting of diffuse vacuolization and loss of muscular striation were observed in histologic sections from 3/32 hearts (16 controls, 16 treated). All three corresponded to THP given at 19 (2/2 mice) or 23 HALO (1/4 mice). Thus lethal, hematologic and possibly cardiac tolerance for THP were largely optimized by administering the drug to mice in their late span (7-10 HALO).

Animals↗