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Biomedical subjects

C Colin

Publications and source records attributed to C Colin.

At least 55 records · Page 3Linked to original sources
PubMed1992

[Cytological and histological studies in stereotactic punctures of non-palpable solid breast lesions].

Cytologic aspiration and core biopsy were performed on 50 nonpalpable breast lesions by using a stereotactic localization technique. Cytologic and histologic results were correlated with mammographic findings and therapeutic decisions were based on the results of both procedures. Representative material was obtained in 100% of the lesions. The sensitivity was 90% and specificity was 97.5%. The predictive values were high except for the predictive value of a negative histologic finding in a suspicious cluster of microcalcifications (50%).

Biopsy, Needle↗
PubMed1991

Lipid peroxidation and benzo[a]pyrene activation to mutagenic metabolites: in vivo influence of vitamins A, E and C and glutathione in both dietary vitamin A sufficiency and deficiency.

Rats fed with either a sufficient-vitamin A or a vitamin A-free diet were pretreated with 750 mg/kg body weight of retinyl palmitate, alpha-tocopherol acetate, ascorbic acid or glutathione. Benzo[a]pyrene (BaP) metabolism and BaP-induced mutagenesis in Salmonella typhimurium TA98 were investigated and related to lipid peroxidation activities in postmitochondrial (S9) liver fraction. The microsomal mixed-function oxidase activities were decreased by vitamin A deficiency and weakly affected by scavenger treatment. The rate of lipid peroxidation of microsomal membranes was unaffected by vitamin A deficiency because of decreased polyunsaturated fatty acids and increased vitamin E contents. However, lipid peroxidation was decreased by pretreatment with fat-soluble vitamins (chiefly vitamin E) and increased by ascorbic acid. Within each experimental group both BaP metabolism and BaP mutagenic activity were closely correlated with the rate of lipid peroxidation. In vitamin A deficiency, the increased BaP metabolism and mutagenicity could be related to a decrease in cytosolic contents of scavengers (vitamin A and glutathione). In Ames test conditions, the free radical pathway became a route for BaP metabolism and thus the BaP activation to mutagenic metabolites is related to the cellular status in free radical scavengers.

Animals↗
PubMed1991

Descriptive analysis of a series of operations for prostatic adenomas in inhabitants of Lyon, France, in 1988. Urological College of Lyon.

A retrospective, population-based study was conducted in Lyon, France, to elucidate the benefits and risks of a treatment for prostatic adenoma (benign prostatic hyperplasia). Case records were reviewed for all prostatectomies performed on patients in Lyon in 1988 for benign prostatic hyperplasia. Data were obtained from all records of public and private hospitals. Of 408 procedures, 312 involved endourethral resection (transurethral resection) and 96 open surgery. The mean weight of resected tissue was 20.3 +/- 0.9 g after endourethral resection and 71.7 +/- 6.4 g after open surgery. About 20% of the resections took place in a university hospital center, 43% in a not-for-profit private hospital, and 37% in a private clinic; there were eight deaths in the first 3 postoperative months, and 11 patients required hospitalization for urologic complications. Length of hospital stay uniquely correlated with age and type of surgery.

Aged↗
PubMed1991

[Hormone substitution therapy in menopause and risk of breast cancer].

If the administration of an estrogen alone increases the risk of breast and endometrium cancer, the addition of a progesterone derivative does not seem to change completely the risk of breast cancer whilst it clearly decreases that of the uterine one. One must be careful in making a large extrapolation of the data on the endometrium (progestogens inhibit the mitotic action of estrogens) to that on the mammary epithelium (inhibition of the estrogen activity at the canal level but synergy with estrogens at the lobe level). The high tissue concentrations of oestradiol at the mammary gland level after menopause could partly explain the small influence of exogenous estrogens administered alone and/or in combination with progestogens on the transformation of a gland already oversaturated with estrogens.

Breast Neoplasms↗
PubMed1990

Influence of early neonatal phenobarbital exposure on cerebral energy metabolism and behavior.

The influence of an early chronic phenobarbital (PhB) exposure on local cerebral glucose utilization (LCGU) and on behavior was studied in the rat. The animals were treated from Postnatal Day 2 to Postnatal Day 35 by a daily injection of 50 mg/kg PhB or by saline and tested between 10 and 35 days for short-term effects of the drug on LCGU and between 70 and 90 days for long-term effects of PhB on LCGU and behavior. PhB induced short- and long-lasting reductions in the overall rates of LCGU in hippocampal and cerebellar areas, but no significant changes in LCGU in the different cell layers of these two cerebral areas. PhB also changed the pattern of maturation of the rates of LCGU as compared to control subjects. The barbiturate treatment induced a decrease in the exploratory behavior of PhB- as compared to saline-treated rats in the open field, as well as a significant 25% decrease in the rate of spontaneous alternation with delay. In addition, PhB-treated rats needed significantly more time than control animals to perform their trials in the nonrewarded T maze testing. However, the neonatal barbiturate exposure did not induce changes in performances of adult rats in the rewarded eight arm maze. The results of the present study show that there is no apparent correlation between the rates of energy metabolism in the hippocampus and the impairment of learning abilities of adult rats in behavioral tests related to the hippocampus.

Animals↗
PubMed1990

Immunodetection of the metastasis-associated laminin receptor in human breast cancer cells obtained by fine-needle aspiration biopsy.

Fine-needle aspiration biopsy of the breast is a very useful technique for the evaluation of a suspect lesion before surgical removal. Increased expression of the 67-kd laminin receptor has been associated with the metastatic phenotype of cancer cells, particularly in colon and breast cancers. In this study, the expression of laminin receptor was evaluated using the immunoperoxidase technique in 81 breast aspirates (26 benign and 55 neoplastic lesions). Cells obtained from benign samples exhibited a low level of laminin receptor antigen detected by affinity-purified antibody raised against a cDNA-derived laminin receptor peptide. In contrast, 71% of smears obtained from malignant breast lesions contained cells that were strongly stained by the antibody. Heterogeneous expression of the laminin receptor was noted in both breast aspirates and fixed tissue specimens. These data suggest that the immunodetection of laminin receptor in cells obtained by fine-needle aspiration of breast lesions could be a valuable adjunct in the prognostic evaluation of breast lesions.

Antibodies↗
PubMed1990

Lymphokine-activated killer cell expansion for clinical trials of adoptive immunotherapy with interleukin-2: optimization of the culture technique.

On leukopheresis products obtained from patients included in a protocol interleukin-2/lymphokine-activated killer (IL-2/LAK) cell therapy, we analyzed, in parallel with the standard culture and on large volumes of these products, different parameters which could either improve LAK cell enhancement or simplify the procedure. We demonstrated first that purification of the mononuclear cells from the leukopheresis product before its culture is not required. An excess of red blood cells and granulocytes (up to 50%) in nonpurified samples improved both the mononuclear cell recovery in short-term culture (4 days) and the activation of LAK cells when the total nuclear cell concentration did not exceed 3 X 10(6)/ml. Different factors can contribute to this enhancing effect: the presence of red blood cells, the liberation of cytokines by granulocytes, or the loss of a population of activated lymphocytes, with liberation of cytokines by granulocytes, or the loss of a population of activated lymphocytes, with larger size and density than resting lymphocytes, during the separation. Supplementation of the medium with 2% heat-inactivated autologous plasma obtained before any treatment rather than with 2% pooled human AB serum does not modify the mononuclear cell recovery in 4-day culture, but it does enhance LAK activity. The inhibitory effect of heat-inactivated autologous plasma on proliferation and activation of LAK cells was never observed, suggesting the absence of suppressive factors in the plasma of the 23 analyzed patients. Similarly, autologous plasma did not modify natural killer and LAK cell functions when added during the cytotoxic assay.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

Possible role of human natural anti-Gal antibodies in the natural antitumor defense system.

Expression of Gal alpha 1-3Gal cell surface residues has been correlated with the metastatic potential of murine tumor cells. We report that Gal alpha 1-3Gal residues are expressed at the cell surface of malignant human cancer cells, including four cell lines and 50% of the malignant breast specimens obtained by aspiration biopsy. In contrast, all benign breast biopsies and normal cells were Gal alpha 1-3Gal negative. Affinity-purified anti-alpha-galactosyl IgG (anti-Gal) antibody, which specifically recognizes Gal alpha 1-3Gal residues, significantly inhibited cell attachment in two in vitro assays thought to indicate tumor cell extravasation of the circulatory system during the metastatic process: attachment to perfused human umbilical vein endothelium, and attachment to isolated laminin. Since anti-Gal antibody is a natural component of all human sera, we propose that it may be part of the natural antitumor defense system in humans.

Antigens, Surface↗
PubMed1989

Analysis of parameters for maximal in vitro proliferation and activation of lymphokine-activated killer cells (LAK).

In 15 patients (11 adults, 4 children) who received IL-2 and LAK cell therapy, we analyzed the different culture conditions which could either improve LAK cell activation and proliferation or which could simplify the procedure. Each parameter was assayed on a large scale and compared to standard culture conditions. Indomethacin had no effects, either positive or negative, on proliferation and activation of the cells. Culturing with 10% AB serum increased proliferation but did not modify total lytic activity compared to 2% AB serum. When cells were cultured in a medium with 2% autologous plasma obtained before any treatment, their proliferation was similar to that obtained in medium supplemented with 2% AB serum but the LAK activity was significantly higher. Autologous plasma obtained at day 8 of treatment (48 h after the first cycle of IL-2 and the day of the first cytapheresis) gave similar results to 2% AB serum. None of the 12 patients showed negative effects suggesting the presence of suppressive factors in the sera. Culturing with autologous plasma in clinical trials will lead to a 25% decrease in the total cost of culture and suppress the risk of viral contamination. Excess of granulocytes in the culture (greater than 30%), if the total nuclear cell concentration did not exceed 3 . 10(6) per ml, induced a better proliferation of mononuclear cells without modification of the activation. These results could be due to the liberation of factors by polynuclear cells, or to the loss during elimination of the granulocytes by the Ficoll separation of cells with similar density supporting LAK activity.

Adult↗
PubMed1988

[Current results of intensive chemotherapy as salvage with bone marrow graft in highly malignant T lymphomas. Apropos of 10 cases].

Eleven autologous bone marrow transplantations (ABMT) were performed in 10 patients with T lymphoblastic lymphoma. All patients were grafted because of a very bad prognosis: 2 cases of progressive disease (1 primary failure, 1 resistant relapse): 0/2 alive, 2 late complete remissions: 1/2 alive, 7 sensitive relapses (2/7 alive). Finally, 3 out of 10 patients are survived. This salvage therapy for a failure of a front line strategy with 78% disease-free survival without ABMT seems of interest. ABMT is still indicated as salvage therapy for 20% of these patients.

Adolescent↗