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Biomedical subjects

G Mathé

Publications and source records attributed to G Mathé.

At least 91 records · Page 5Linked to original sources
PubMed1993

The in vivo effect of ellipticine analogues on the blood concentration of Friend virus: a murine model for studying anti-HIV drugs.

The viremia of a mouse carrying a murine retrovirus, the Friend virus, was taken as a model for screening drugs which could be active on the human HIV retrovirus. Ellipticine and two of its analogues injected ip at appropriate doses drastically reduced the viremia of the Friend virus-injected mice, as measured by transfer of their serum on day 8 of the treatment to secondary recipients and numeration, in the spleens of the latter, of the foci the remaining virus had induced. Since phase I and II trials have already been published (for leukemia treatment), the efficacy of those drugs on HIV-1 positive AZT-resistant patients can be tested directly.

Acquired Immunodeficiency Syndrome↗
PubMed1992

Radical tumor excision and cosmetic balance in the surgical treatment of breast carcinoma: biquadrantectomy.

The present trend in favor of conservative surgery is in contrast with histopathological findings of multicentric breast carcinoma, which may be responsible for the occurrence of relapses in spite of the use of radiation therapy. As a consequence, conservative surgery appears to be inadequate, especially when tumor size exceeds 2 cm. Therefore for tumors up to 4 cm in size, which are not adherent to the pectoral fascia, we propose the excision of two quadrants with concomitant operation on the contralateral breast resulting in a more symmetrical and therefore cosmetic effect. This is a more radical procedure than the removal of the one quadrant.

Breast Neoplasms↗
PubMed1992

Retrospective study correlating clinical infectious history and peripheral blood T-cell subpopulations in cancer, GvH and HIV+ patients.

The CD4+ CD8- inducer helper cell and the CD4- CD8+ cytotoxic/suppressor cell absolute numbers were measured in the peripheral blood of patients with various pathological conditions: with leukemia-lymphomas or solid tumors, patients with bone marrow grafts suffering from GvH, HIV-1 asymptomatic carriers, ARC and AIDS patients. The study was carried out during observation periods when they were not suffering from opportunistic infections and were untreated. In all the groups a decrease of the CD4+ CD8- cell absolute number was observed. In the leukemia-lymphoma and solid tumor bearing patients the CD4- CD8+ absolute value was lower than normal, while in the GvH- and HIV-infected patients, it was significantly higher. The clinical follow-up of each group indicates that GvH, ARC and AIDS patients developed infection in 40-68% of the cases, ie the only groups at risk of infection are those in which the CD4- CD8+ absolute values are high: we suggest that the balance CD4+ versus CD8+ should be considered rather the absolute CD4+ when discussing appropriate use of immuno-regulators.

AIDS-Related Opportunistic Infections↗
PubMed1992

Phase I trial of Perrimustine, a new cysteamine (2-chloroethyl) nitrosourea: an intrapatient escalation scheme.

The recently synthesized nitrosourea, N-[N'-chloro-2-ethyl-N'-nitrosocarbamoyl]-S-methyl cysteamine sulfoxide (Perrimustine), is water soluble and has a high alkylating activity, similar to that of the widely used nitrsoureas BCNU and CCNU, and a low carbamoylating activity. Preclinical studies with a broad spectrum of murine tumors indicate that this new compound may be clinically useful. The maximally efficient dose range (MEDR) in L1210 bearing mice was 45 mg/m2 (subcurative dose) to 67 mg/m2 (subtoxic dose). The present phase I trial used an intrapatient escalation schedule, so that each patient entering the study received a potentially active dose. The first dose injected was 1:100 of the MEDR suboptimal dose to check for anaphylactic sensitivity. Patients were then given increasing doses at increasing time intervals until toxicity was observed. The highest dose was given on day 150-230. The main toxic effect was myelosuppression [five out of the 24 patients evaluated: one grade 4 thrombocytopenia, two grade 3 thrombocytopenia; anemia and leucopenia were milder (grade 1 to 2 on OMS scale)]. Of the 19 patients evaluated for clinical response, one showed response after the 45 mg/m2 dose (disappearance of the cerebral metastasis with persistence of hepatic localizations in a patient with melanoma) and the disease was stabilized in two cases (a pleural mesothelioma and a renal carcinoma with lung metastases) after 26 and 37 weeks, with total cumulative doses per m2 of 232 and 196 mg, respectively.

Adolescent↗
PubMed1992

Combined differentiation therapy in myelodysplastic syndrome with retinoid acid, 1 alpha,25 dihydroxyvitamin D3, and prednisone.

The myelodysplastic syndrome (MDPS) provides an opportunity for identifying host factors (genetic, endocrine, immune) involved in initiation and progression of preleukemia into frank acute myeloid leukemia. The aim of this study was to identify bone marrow (BM) cellular and humoral dysfunctions central to the development of MDPS and useful in therapeutic follow-up studies. Our preclinical studies have shown that (1) the characteristic stromal cell composition of the normal BM microenvironment was impaired in MDPS and in AML in 67 and 86% of the cases, respectively; (2) the 1 alpha,25(OH)2D3 concentration in BM plasma was abnormal in 50% of MDPS and 30% of AML; and (3) an inverse correlation existed in MDPS between the 1 alpha,25(OH)2D3 concentration and the frequency of F-CFU, (r = 0.41, p < 0.02), suggestive of a regulatory interaction between this secosteroid hormone and BM stromal cells. The analysis of clonal extinction of BM blast cells in response to all trans retinoic acid (RA), 1 alpha,25(OH)2D3, and colony stimulating factors (PHA-LCM), either alone or in various combinations, revealed individual patterns of responses in the cases of MDPS or AML. The results indicate the necessity for preclinical studies to select patients for combined differentiation therapy. Our ongoing clinical trials suggest that RA (Roaccutan, 20 mg/day continuously) as induction therapy, followed at weeks 6 to 8 by prednisone (40 mg/day for 15 days) and 1 alpha,25(OH)2D3 (Rocaltrol, 3 x 0.25 micrograms/day for 3 months) may induce a long-lasting hematological remission in MDPS.

Bone Marrow↗
PubMed1991

Retinoic acid in mono- or combined differentiation therapy of myelodysplasia and acute promyelocytic leukemia.

Myelodysplastic preleukemic syndromes (MDPS) and acute promyelocytic leukemia (APL) share a surprising in vivo sensitivity to the hormonally acting 13 cis or all trans retinoic acids (transRA). Here we show that transRA as a monotherapeutic agent induced a stable remission in APL at the third relapse. In MDPS, treatment with prednisone and 1 alpha,25-dihydroxyvitamin D3 (1 alpha,25D3) 13 cis RA induced a long-lasting hematological remission. Initially both patients had an impaired BM microenvironment which regenerated on retinoid therapy as judged by reappearance of the Hematon fraction in the BM aspirates. Our preclinical experiments using long-term liquid BM cultures (LTBMC) indicated that several individual patterns of growth and differentiation responses can be induced by combinations of transRA, 1 alpha,25D3 and hemopoietic growth factors (HGFs). The biological responses may vary from complete clonal extinction to a significant growth stimulation of the leukemic blast cell populations. These results further support the importance of preclinical studies in selecting "good" responders for, and excluding "poor" responders from protocols using differentiation therapy.

Bone Marrow↗
PubMed1991

Bestatin, an aminopeptidase inhibitor with a multi-pharmacological function.

Bestatin, the dipeptide N-((2S, 3R)-3-amino-2-hydroxy-4-phenyl butanyl) L-leucine is a leucine aminopeptidase and aminopeptidase-B inhibitor. It exerts a direct stimulating effect on lymphocytes (and monocytes) via its fixation on cell surface leucine-aminopeptidase, and an indirect effect on monocytes (and lymphocytes) via aminopeptidase B inhibition of tuftsin catabolism. Thus it is an immuno-modifier as shown by the Japanese and also our groups: a) immuno-modifier, especially stimulator, in normal young mice; b) immunorestorator and spontaneous tumor preventive agent in aged mice; c) immunorestorator in the elderly and in cancer patients and HIV infected subjects. It stimulates granulocytopoiesis and thrombocytopoiesis in vitro, and can restore them in vivo in myelo-hypoplastic man. The anti-aminopeptidase action of Bestatin also protects enkephalins against their catabolism, which encouraged us, with good preliminary results, to study its analgesic action and search for a preventive effect on "desaddicted" toxicomaniac relapses.

Aminopeptidases↗
PubMed1990

Phase I trial of 5-day continuous venous infusion of oxaliplatin at circadian rhythm-modulated rate compared with constant rate.

The toxic effects and tissue uptake of both cisplatin and oxaliplatin--[(1R, 2R)-1,2-cyclohexanediamine-N,N'] [oxalato(2-)-O,O']platinum--were previously shown to vary similarly according to dosing time in mice. A 4-hour infusion of cisplatin resulted in fewer side effects and allowed administration of higher doses at 16 hours than at 4 hours in patients with cancer. We hypothesized that the continuous venous infusion of oxaliplatin for 5 days would be less toxic and would deliver a higher dose to the patient if the drug were infused at a circadian rhythm-modulated rate (peak at 16 hr; schedule B) rather than at a constant rate (schedule A). We tested this hypothesis in a randomized phase I trial. We escalated the dose of oxaliplatin to the patient by 25 mg/m2 per course. Courses were repeated every 3 weeks. An external, multichannel, programmable-in-time pump was used for the infusions. Toxicity was assessable for 94 courses in 23 patients (12 patients with breast carcinoma, nine with hepatocellular carcinoma, and two with cholangiocarcinoma). The incidence of neutropenia of World Health Organization grades II-IV and the incidence of distal paresthesias were 10 or more times higher (P less than .05) with schedule A than with schedule B. In addition, vomiting was 55% higher (P = .15) with schedule A than with schedule B. Furthermore, with schedule B, the mean dose of oxaliplatin (P less than .001) and its maximum tolerated dose (P = .06) could be increased by 15% over those doses with schedule A. An objective response was achieved in two of the 12 patients with previously treated breast cancer. We recommend that the dose of oxaliplatin for phase II trials be 175 mg/m2, delivered according to the circadian rhythm-modulated rate.

Adult↗
PubMed1990

Results of multidisciplinary limb salvage in 240 consecutive bone sarcomas.

From 1979 to 1989, 240 bone sarcomas of limbs were treated by a multidisciplinary limb salvage protocol. The tumors included 112 osteosarcomas, 71 chondrosarcomas, 3 fibrosarcomas, 10 malignant histiocytofibromas, 40 Ewing's sarcomas and 4 other rarer sarcomas. Patients mean age was 28.6 yr (range 4-91 yr). The average tumor size was 13.5 cm (3-43 cm). There were 2 grade IA, 21 IB, 1 IIA, 188 IIB, and 28 III B according to Enneking's classification. Extratumoral en bloc resection was performed in all cases (large in 113, marginal in 121, intrafocal in 6) by the same surgeon. In poor responders to preoperative chemotherapy with Ewing's sarcomas or osteosarcomas, 35 Grays postoperative radiotherapy was administered. Ewing's sarcomas and osteosarcomas received short preoperative and long postoperative chemotherapy. At last follow-up (median 60 months, range 6-120 months), 150 patients were disease-free; 4 were under treatment and had visible disease; 86 had died. Actuarial disease-free survival rate for patients seen with localized previously untreated disease was 83% at 2 yr and 77% at 3 yr. Fifteen local recurrences were observed (6%). Statistical analysis confirmed the poor prognosis factors of visible metastasis, proximal location and large tumor size, and pointed out the major prognostic value of therapeutic factors: the effectiveness of chemotherapy in Ewing's sarcoma and osteosarcomas, and the adequacy of surgery in all cases. Limb salvage can be performed by a well experienced multidisciplinary team in 96% of limb sarcomas without major risk of local recurrence. However, amputation is safer if the surgeon lacks experience.

Adolescent↗
PubMed1990

Virostatic in vivo effect of elliptinium on Friend's retrovirus (a model for HIV infection).

As we had discovered the virostatic effects of some analogues of acriflavine, a non-oncostatic intercalating agent, on HIV1 and on its best murine model, Friend's virus [7], we then studied other non- or poorly oncostatic intercalating agents, in particular ellipticins (whose negligible cytostatic effect with methoxy-9-ellipticin we first published. We report in this paper the in vivo virostatic effect of 2-methyl-9-hydroxy-ellipticinium (elliptinium) on Friend's virus.

Animals↗