Browsing by Author "LEON, A"

Now showing 1 - 9 of 9
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    CONSERVATIVE TREATMENT OF EARLY BREAST-CANCER
    (1988) BAEZA, MR; SOLE, J; LEON, A; ARRAZTOA, J; RODRIGUEZ, R; CLAURE, R; CORNEJO, S; CORNEJO, J
    At our institution, and treatment policy for early carcinoma of the breast (T1-2, NO, AJC) is lumpectomy followed by radiotherapy to the breast and peripheral lymphatics. From October 1976 until December 1982, 171 patients have been admitted and treated. Radiotherapy was administered with 60 Co, 5.000 cGy in 5 weeks to the breast and lymphatics plus a boost to the scar giving q.s.p. 6.400 cGy at maximum tumor depth. With a minimum followup of 3 years and a median follow-up of 61.7 months the locoregional control was 94.2% and survival at 8 years with no evidence of disease (NED) was 77.2% with an overall survival rate of 90%. No difference in NED survival rate was found between Stage I and II. There was a tendency to better survival rate in those patients older than 50 years and also for post menopausal patients, however the difference did not reach statistical significance (66.7% NED survival at 8 years for premenopausal and 81.8% NED survival for post menopausal, also at 8 years, p = 0.056 Gehan). The time elapsed between surgery and radiation therapy (between 1 and 2 months) was found to be nonsignificant. Only 1 out of 171 patients has had axillary dissection. The importance or lack of it, is discussed.
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    SIZE-EXCLUSION CHROMATOGRAPHY OF POLY(NORMAL-ALKYL ITACONATE)S - NONEXCLUSION EFFECTS
    (1992) RADIC, D; GARGALLO, L; LEON, A; HORTA, A
    Poly(n-alkyl itaconates) containing long alkyl side chains (comb polymers) are eluted through PS gel in THF at 298 K. Their retention volumes are higher than those predicted by universal calibration, indicating affinity of the polymers for the gel. The distribution coefficient for solute-gel interactions, Kp(Kp > 1), increases with polymer molecular weight. This increase is larger for the polymer bearing the longest n-alkyl side chain and is scarcely sensitive to the presence or absence of free carboxylic groups in the polymer (monoitaconates). This might be due to a balance of the solute-gel and solute-solvent interactions.
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    SYNTHESIS AND SOLUTION PROPERTIES OF COMB-LIKE POLY(MONO-NORMAL-ALKYL-ITACONATES) .2. POLY(MONODODECYL ITACONATE)
    (1991) LEON, A; GARGALLO, L; RADIC, D; HORTA, A
    The monoester of itaconic acid with n-dodecyl alcohol was synthesized and polymerized. Polymer fractions were characterized by viscometry, size exclusion chromatography (s.e.c.) and light scattering. Thermodynamic and dimensional parameters were determined and calculated. The results found are 67 angstrom for the statistical segment length l and 8 angstrom for the chain diameter d. These results are compared with those reported previously for a similar compound.
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    SYNTHESIS, DILUTE-SOLUTION PROPERTIES AND CHAIN FLEXIBILITY OF POLY(DIESTERS) OF ITACONIC ACID .2. POLY(METHYL DECYL ITACONATE)
    (1992) LEON, A; GARGALLO, L; RADIC, D; BRAVO, J; HORTA, A
    The diester of itaconic acid with decyl and methyl groups was prepared and polymerized. The dilute solution behaviour of poly(methyl decyl itaconate) poly[1-(decyloxycarbonylmethyl)-1-(methoxycarbonyl)ethylene] (PMeDI) was studied in tetrahydrofuran and 1-butanol at 298 K, by light scattering, size-exclusion chromatography, and viscometric measurements. The empirical Kuhn-Mark-Houwink-Sakurada relationships were established. The molecular parameters were calculated using one theory of the excluded volume.
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    SYNTHESIS, SOLUTION PROPERTIES, AND CHAIN FLEXIBILITY OF POLY (METHYL DODECYL ITACONATE)
    (TAYLOR & FRANCIS INC, 1990) LEON, A; LOPEZ, M; GARGALLO, L; RADIC, D; HORTA, A
    The dilute solution behavior of poly(methyl dodecyl itaconate) (PMeDoI) has been studied in THF and n-butanol at 298 K, by intrinsic viscosity, light scattering, and size-exclusion chromatography (SEC) measurements. The Kuhn-Mark-Houwink-Sakurada relationships were established. The flexibility factors sigma and C infinity and the thermodynamic parameters B were calculated using the Stockmayer-Fixman equation. The A2 and the B values are indicative of the presence of the excluded volume effect. The results obtained are compared with those previously found for poly(mono dodecyl itaconate) (PMDoI) and discussed in terms of specific influence of the free carboxylic group in the poly(monoester).
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    TREATMENT OF BREAST-CANCER IN MALES
    (SOC MEDICA SANTIAGO, 1995) WAUGH, E; BAEZA, R; LEON, A
    Breast cancer is an unusual disease in males. We report the treatment results in 12 male patients with breast cancer and without distant metastases at the moment of diagnosis, treated between 1978 and 1993. All were subjected to surgical resection and radiotherapy; chemotherapy was not used. In four patients with local lymph node involvement, tamoxifen was used. Clinical staging at the moment of diagnosis was stage I in one patient stage II in seven and stage III in four. Subjects were followed for a mean of 67 months and a median of 56 months. Local control of the tumour was achieved in 100% of patients and five years survival was 90%. Two patients presented with distant metastases at nine and 106 months of follow up. It is concluded that breast cancer in men has a similar survival rate than in women.