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Biomedical subjects

J Raus

Publications and source records attributed to J Raus.

125 records · Page 7Linked to original sources
PubMed1981

Cytotoxic estrogens in hormone receptive tumors.

A high proportion of human mammary cancers contain a measurable amount of estrogen receptors. The presence of estrogen receptors correlates well with the response of patients to endocrine therapy, but not with their response to chemotherapy. However, receptor-mediated chemotherapy should result in more selective and efficient treatment of receptor-positive tumors. Several agents containing an estrogenic and a cytotoxic moiety have been synthesized in the past. It is not surprising that the affinity of these compounds for the estradiol receptor is very low, since most of them were synthesized before our knowledge of hormone receptor mechanisms. An international workshop on cytotoxic estrogens was held on September 27-28, 1979, in Diepenbeek, Belgium, to celebrate the opening of the Dr. L. Willems-Instituut. The purpose of the workshop was to determine the structural requirements for binding to the estrogen receptor and to obtain a consensus on screening techniques for selecting potential drugs of this type.

Animals↗
PubMed1981

The pharmacokinetics of some aminoglycoside antibiotics in the horse.

The disposition kinetics and bioavailability of streptomycin, kanamycin and neomycin were determined following their administration as parenteral preparations to horses. Single doses (10 mg/kg) of each aminoglycoside were given by the intravenous (i.v.) and intramuscular (i.m.) routes and, at a later time, seven intramuscular doses were injected at 12-h intervals. The pharmacokinetic behaviour of the three aminoglycosides was similar, in that a rapid distribution phase was followed by a relatively short half-life. The half-life (mean +/- SD, n = 6) of kanamycin (1.80 +/- 0.17 h) was significantly (P less than 0.01; t test, 10 d.f.) shorter than that of streptomycin (3.40 +/- 0.42 h), while neomycin half-life (2.10 +/- 0.97 h) was of an intermediate length. The apparent volume of distribution of neither kanamycin nor neomycin varied significantly (P greater than 0.05) from that of streptomycin and numerically (V1 d congruent to 230 ml/kg) was the same as the extracellular fluid volume. The body clearance of kanamycin (88.5 +/- 11.3 ml/kg.h) was significantly (P less than 0.01) larger than that of streptomycin (47.5 +/- 7.9 ml/kg.h), while a significant difference in this parameter did not exist (P greater than 0.05) between neomycin and streptomycin. Following intramuscular injection, each aminoglycoside was rapidly and completely absorbed from the injection site, although neomycin showed wide individual variation in the fraction absorbed. The administration of multiple doses did not change either the bioavailability or the apparent half-life from the values obtained after a single dose. The only pharmacokinetic difference between these aminoglycosides that is of clinical importance lies in the rate of their elimination. A dosage interval of 8 h would be appropriate for kanamycin compared with a 12-h interval for streptomycin. The dosage interval for neomycin based on half-life should be 8 h but, due to the relatively greater toxicity of this aminoglycoside, an interval of 12 h might be recommended. The height of the peak serum concentration is determined by the size of the dose.

Aminoglycosides↗
PubMedDate not supplied

Pituitary and adrenal hormone responsiveness to Synacthen in melancholic subjects versus subjects with minor depression.

Increased adrenal cortex responsiveness to adrenocorticotropic hormone (ACTH) has been suggested to contribute to increased cortisol secretion in dexamethasone nonsuppression and melancholia. To further examine this hypothesis, the following variables were examined in 68 patients with unipolar depression (minor, n = 24; simple major, n = 25; melancholic, n = 19): basal or post-Synacthen [ACTH(1-24), 250 micrograms IV] intact ACTH(1-39), beta-endorphin/beta-lipotropin, cortisol, and androstenedione concentrations, as well as the postdexamethasone (DST) plasma ACTH(1-39) and cortisol values. Melancholic subjects showed significantly higher baseline ACTH(1-39), beta-endorphin/beta-lipotropin, and androstenedione values compared with subjects with minor depression. No significant differences in post-Synacthen cortisol or androstenedione secretion between any of the groups or between [ACTH(1-39) or cortisol] DST nonsuppressors and suppressors were found. No significant relationships between DST and ACTH test results were observed. Abnormally increased post-DST cortisol values in melancholic subjects were highly predicted (> 68% of the variance) by post-DST intact ACTH levels. ACTH(1-39) values were significantly lower after Synacthen administration in melancholic subjects than in subjects with minor depression. These results are not consistent with the hypothesis that melancholia is characterized by an increased adrenocortical responsivity to exogenous ACTH compared with minor depression or that DST nonsuppression is due to adrenal hyperresponsiveness.

Adrenal Cortex Hormones↗
PubMedDate not supplied

Immune cell parameters in severely depressed patients: negative findings.

Cross-sectional population studies reported decreased mitogen-induced lymphocyte responsiveness in severely depressed patients. This immunologic impairment, indicative of T- and/or B-cell dysfunction, was related to disturbances in the dexamethasone suppression test (DST) and to age effects. Glucocorticoid overdrive, a hallmark for severe depression, exerts immunosuppressive effects through the impact on neutrophils, lymphocytes, and monocytes and natural killer cells (NKC). This paper has analyzed the relation of peripheral blood immune parameters to severe depression, DST results and age. The population consisted of 37 inpatients categorized according to DSM-III as minor depression (300.40, 309.00), simple major depression (296.X2) or major depression with melancholia and/or with psychotic features (296.X3, 296.X4). The number of leukocytes, neutrophils, lymphocytes and monocytes was counted. T-cell (total T-cell, T-helper, T-suppressor, HLA-DR), B-cell (LN1 and immunoglobulin (Ig) receptors), monocytes (M1 and M3 membrane antigens) and NKC activity were identified by phenotype using monoclonal antibodies. No differences were detected between the depressive subgroups for any of the parameters examined. There were no relationships between these immune variables and the severity of illness, DST results or age.

Adult↗
PubMedDate not supplied

Immune disturbances during major depression: upregulated expression of interleukin-2 receptors.

We determined the following immune parameters in drug-free, major depressed patients and in age- and sex-matched healthy controls: the number and percentage of interleukin-2 receptor (IL-2R) bearing cells (CD25+, anti-TAC), serum circulating levels of soluble (s)IL-2Rs, the pre- and postdexamethasone phytohemagglutinin (PHA)-induced accumulation of sIL-2Rs in culture supernatant, and the number of T helper (CD4+) and T suppressor (CD8+) cells. In comparison with normal volunteers, patients with major depression had a higher number and percentage of CD25+ cells, higher concentrations of serum circulating sIL-2Rs, higher supernatant sIL-2Rs after stimulation with PHA, and a higher number of CD4+ cells. The CD4+/CD8+ ratio and the number of CD4+ cells were significantly and positively related to the number of cells expressing the CD25+ antigen. These results may indicate that depressed patients display an increased number of T cells in an early phase of activation.

Adult↗
PubMedDate not supplied

Phenotypic analysis of tumor-infiltrating lymphocytes from human breast cancer.

Suspensions of fresh tumor-infiltrating lymphocytes (TIL) were prepared from 30 human breast ductal adenocarcinomas. To evaluate the phenotypic pattern of the isolated TIL, lymphocyte surface markers including CD19, CD3, CD4, CD8, CD16 and HLA-DR were examined by flow cytometry. Lymphocyte recovery ranged from 1.1% to 44%, independent of tumor size. TIL most often scored high for CD3+ with a varying number of CD4+ and CD8+ cells. Three samples out of 30 expressed up to 44% of CD19+ B cells, while CD3-CD16+ NK cells were rare. CD4 and CD8 expression was significantly different between the lymph node metastases group and the lymph node negative group (p < 0.01). 67% of the TIL with a CD4/CD8 ratio greater than 1 showed lymph node metastases. Furthermore, the CD4 expression of TIL and CD4/CD8 ratio correlated with tumor size (p < 0.01), but not with tumor differentiation and hormone receptor expression. Although there was considerable diversity of TIL among breast tumors, our data suggest that a high expression of CD4+ T cells may imply progression of the tumor, and an increased CD4/CD8 ratio of the TIL isolated from human breast adenocarcinoma may indicate development of metastases.

Adult↗
PubMedDate not supplied

Large scale expansion of human tumor infiltrating lymphocytes with surface-modified stimulator cells for adoptive immunotherapy.

Expansion of tumor infiltrating lymphocytes (TIL) in vitro is hampered by several factors, including a limited amount of lymphocytes obtained from different tumors, unknown target antigens and limited supply of antigen-presenting cells (APC) which are generally believed to be essential in the classical way of T cell stimulation and expansion. In approaching these difficulties, we have recently used surface-oxidized allogeneic PBL to stimulate the TIL periodically in the presence of a low dose of rIL-2 (200 IU/ml). TIL derived from 22 (out of 23) tumor specimens could be expanded with 20 -10(7) fold increases over 6-16 weeks to a sufficient amount of 10(9) -10(11) cells for adoptive immunotherapy. In contrast, only 2-100 fold increase were observed in six tumor specimens (out of 23) when 200 IU/ml rIL-2 was used only. The phenotypes, autologous tumor reactivity and cytolytic capability of TIL propagated with surface-oxidized stimulators were similar to those expanded in the presence of IL-2 alone. These data suggest that expanding TIL with surface-modified stimulator cells could be a useful alternative method to obtain a large amount of tumor specific cytolytic T cells for clinical immunotherapeutic use, irrespective of tumor-antigen stimulation and MHC restriction.

Breast Neoplasms↗
PubMedDate not supplied

Production of immunohistochemical reactivity of mouse anti-epithelial monoclonal antibodies raised against human breast cancer cells.

Mouse monoclonal antibodies (Mabs) against the human breast cancer cell line MCF-7 were obtained by fusing spleen cells from immunized mice with SP2/0 myeloma cells. The Mabs obtained show a high degree of specificity for epithelial cells. They react in a heterogeneous way with neoplastic and non-neoplastic tissues. Mabs 5D10, 2B4, and 3B7 recognize the same antigen (MW 80,000-90,000) in fresh tissue and in paraffin embedded sections. Mab 11F9 recognizes another antigen which can only be detected in unfixed tissue and not in paraffin sections. A preliminary study suggests a glycolipid nature of all recognized antigens. At least one of the monoclonal antibodies (5D10) developed can be used in an in vitro and in vivo model for the study of the invasiveness of MCF-7 cells.

Animals↗
PubMedDate not supplied

Specific monoclonal antibodies reacting with human breast cancer cells.

Spleen cells from Balb/c mice immunized with human breast cancer cells (MCF-7) were fused with murine myeloma SP2/0 cells. Screening of the monoclonal antibodies produced was carried out on glutaraldehyde fixed cells coated on microtiterplates. An initial evaluation of the specificity was obtained by comparing the binding of the monoclonal antibodies to MCF-7 cells with the binding to human peripheral blood lymphocytes. Eight monoclonal antibodies reacting with different epitopes on the MCF-7 cells were obtained. On the basis of their clonal origin, isotype and reaction pattern towards the MCF-7 cells these monoclonal antibodies were subdivided into two classes. Both groups of antibodies reacted with fixed and unfixed MCF-7 cells. The cellular distribution of the antigens recognized by the monoclonal antibodies was determined. To check for specificity a panel of different cells (of human and animal origin) was evaluated by immunocytochemical techniques.

Antibodies, Monoclonal↗
PubMedDate not supplied

In vivo distribution of radio-labeled tumor infiltrating lymphocytes in cancer patients.

Tumor-infiltrating lymphocytes have proven effective in murine tumor models and preliminary clinical trials. To evaluate the efficacy of these lymphocytes in treatment attempts were made to study the in vivo migration and distribution of these lymphocytes. Tumor-infiltrating lymphocytes isolated from five patients with malignant metastatic breast cancer or melanoma cultured and expanded in vitro with low-dose of recombinant interleukin-2 were labeled with 111Indium-oxine and infused to the patients. A large view gamma camera was used to evaluate the distribution and localization of the infused TIL. Localization of 111In-labeled TIL in the lungs was seen within two hours after infusion and high levels of radioactivity were observed at 24 hours in lungs, liver and spleen. The activity in the lungs diminished after 72 hours. No specific localization of 111In-labeled TIL was observed in the metastatic sites.

Adolescent↗