PubMed Health⌕ Search

Biomedical subjects

R Kolb

Publications and source records attributed to R Kolb.

At least 37 records · Page 2Linked to original sources

Effects of atenolol alone, nifedipine alone and their combination on ambulant myocardial ischemia.

The effects of atenolol (100 mg/day) and nifedipine (20 mg 3 times daily) and their combination on ambulant myocardial ischemia were investigated using a randomized, double-blind, placebo-controlled, crossover trial. Eighteen men with symptomatic coronary artery disease, exercise-induced ischemia and minimal symptoms, underwent 4 blinded treatment periods of 2 weeks' duration (2 placebo, 1 atenolol, 1 nifedipine). Those that did not have ischemia eliminated by monotherapy received combination therapy with both drugs. Forty-eight-hour ambulatory electrocardiographic monitoring was used to quantitate ischemic parameters at the end of each period. Both nifedipine and atenolol as monotherapy reduced the number of ischemic episodes and the average duration of each episode compared with placebo (p less than 0.05). Compared with placebo, nifedipine reduced the total duration of ischemia (p less than 0.05) but the effect of atenolol on ischemia duration was of borderline significance (p = 0.066). There were no differences in reduction of ischemic parameters when atenolol was compared with nifedipine (difference not significant). In the 9 patients who continued to have ischemia with monotherapy, combination therapy eliminated it in 2 and reduced the duration by greater than 50% in the remaining patients compared with placebo. In conclusion, monotherapy with nifedipine or atenolol is similarly effective in eliminating or reducing ambulant ischemia. Combination therapy can provide additional benefit in those with continued ischemia.

Adult↗

[Steroid hormone receptors in mammary carcinoma. Immunohistochemical detection and prognostic significance].

Estrogen and progesterone receptors were immunohistochemically recorded from 426 cases of primary mammary carcinoma. Immunohistochemical detection was based on monoclonal antibodies to estrogen receptor (H222) and progesterone receptor (KD68). Immunohistochemical and biochemical tests were correlated to each other with significance (p less than 0.0001) for either receptor. Some of the histological parameters exhibited relationships with the immunohistochemical receptor status. Receptor positivity of lobular, mucoid, tubular, and papillary carcinomas was more frequent than that of ductal carcinoma, whereas that of medullary carcinoma fell below ductal cases. A straight forward correlation of statistical significance was found to exist between histological tumor grade and steroid hormone receptor status. Receptor positivity of carcinomas with sizeable stroma components proved to be more frequent than that of carcinomas with lower stroma levels. Steroid hormone receptors can be immunohistochemically identified from cytological specimens, as well, though some limiting factors are implied in the latter. Thirteen percent of fine-needle aspirates provided falsely negative steroid hormone receptor findings, as compared to histological biopsy. This problem was encountered primarily in cases of low receptor positivity and high stroma content of carcinoma, factors for which only minor amounts of cell material could be obtained from puncturing. Clinical follow-up checks and evaluation of survival data revealed the immunohistochemically determined steroid hormone receptor status to be of significant importance to prognostication (ER-ICA p less than 0.00001; PgR-ICA p = 0.004). The prognosis of patients with negative estrogen and progesterone receptors was found to be worse than that of patients with positive receptor status. These studies are likely to confirm immunohistochemical determination of steroid hormone receptors, using monoclonal antibodies, to be a reliable method of great prognostic importance.

Adenocarcinoma↗

[Androgen receptors in primary breast carcinoma. Relation to prognostic factors in comparison with estrogen and progesterone receptors].

Androgen receptor content was correlated with various prognostic factors in 274 patients with breast cancer. Receptor content was determined by the dextran-coated charcoal method (DCC). No direct relationship was found between androgen receptor content and age of patient, menstruation status, TN status and number of affected lymph nodes. But in 232 patients in whom tumour differentiation could be determined, there was a highly significant relationship between it and androgen receptor content (P less than 0.01). Similar correlations were found also between these prognostic factors and oestrogen or progesterone receptors. The percentage distribution of tumours of different degrees of differentiation was independent of the kind of demonstrable steroid-hormone receptor. However, the frequency of highly differentiated tumours rose with the number of different receptors that were determined. Thus steroid-hormone receptors can be considered as markers for differentiation. It seems possible that the additional determination of androgen receptors allows for a more exact selection of patients who should receive hormonal treatment.

Adult↗

Natural killer cell activities of patients with breast cancer against different target cells.

Natural killer (NK) cell activity against K 562 erythroleukemic- and MCF-7 breast carcinoma-derived cells was monitored in short-term (3 h/K 562) and long-term (18 h/MCF-7) chromium release tests for 60 patients with untreated primary breast disease. Target cell lysis was the same for patient groups with benign (n = 13) and malignant (n = 47) breast disease (27% versus 36% mean chromium release; target:effector ratio 40:1 for K 562 and 28% versus 40% for MCF-7 cells). NK activity as defined by short-term lysis of K 562 cells did not correlate with MCF-7 cell lysis in long-term assays for the carcinoma patients. This functional heterogeneity of natural cytotoxic activities of breast cancer patients was confirmed by a different age distribution for K 562 and MCF-7 cell lysis and high levels of MCF-7-directed NK activity in the grade I tumor group (56.2%). Our results indicate that measurement of peripheral blood NK activity against a breast carcinoma-derived cell line (MCF-7) defines a disease-related natural cytotoxic activity which correlates better with prognostic tumor parameters (tumor grading) than NK activity as defined by the lysis of K 562 erythroleukemic cells. NK activity testing against breast carcinoma cell lines should be used to monitor natural cytotoxic activities in breast cancer patients and its modulation by different routes of treatment.

Adult↗

Possible adverse effect of failed adjuvant chemotherapy on the prognosis of women receiving consecutive chemotherapy for recurrent breast cancer.

This study tried to evaluate the impact of adjuvant chemotherapy on the induction of chemoresistance in radically operated upon breast cancer patients. Remission rate, remission duration and survival of a group of women (n = 22) treated with combination chemotherapy (adriamycin and cyclophosphamide, AC) for recurrent breast cancer after failed adjuvant therapy (cyclophosphamide, methotrexate, fluorouracil, vinblastine) were retrospectively compared with the clinical data of non-pre-treated patients (n = 28) receiving the same regimen (AC). The two groups of patients were comparable with regard to their risk factors. In the group of women with prior adjuvant chemotherapy only 3 out of 22 had a partial response, lasting 3, 8, and 16 months; the median survival was 50 months. In the group without prior adjuvant therapy 3 complete and 7 partial remissions with a median remission duration of 15.5 months (range 2-54 months) were found; the median survival was 104 months. The percentage of objective responses among the non-pre-treated patients at 36% was almost significantly higher than that of the pretreated women with 14% (p less than 0.1). Responders to chemotherapy after relapse profited in terms of survival within the first 3 years after radical mastectomy, although no statistically significant difference was observed. The survival data shown assume a "shifting" of women from a group with better prognosis to a group with unfavourable prognosis following failed adjuvant chemotherapy.

Antineoplastic Combined Chemotherapy Protocols↗

Prognostic significance of steroid hormone receptors and histopathological characterization of human breast cancer.

Since breast cancer is a heterogeneous disease, evaluation of prognosis is an obvious problem. The prognostic significance of several pathological criteria including tumor grading according to WHO, steroid hormone receptor status, histological tumor type, tumor size, and axillary lymph node involvement have been investigated. The single parameters with the strongest prognostic significance were axillary lymph node status, tumor grading, and estrogen receptor status. A significant direct correlation exists between tumor grading and steroid hormone receptors, but nevertheless on stratified analysis both factors independently affected the risk of death. Tumor size had weak prognostic importance and histological tumor types failed to show any statistically significant differences with regard to survival.

Adult↗

Estrogen receptor immunocytochemistry for preoperative determination of estrogen receptor status on fine-needle aspirates of breast cancer.

Fine-needle aspirates (FNAs) of 84 primary breast carcinomas were analyzed immunocytochemically for estrogen receptor (ER) using (ER-ICA) monoclonal antireceptor antibodies. ER-ICA in FNAs was concordant to ER-ICA in histologic biopsies in 87% (P less than 0.0001). In most of the carcinomas, biochemically determined ER status also correlated to ER-ICA. There was no false positive ER-ICA in FNAs compared with ER-ICA in histologic biopsies. In 11 FNAs, ER-ICA was negative, whereas it showed positivity in histologic specimens. The most frequent contributing factors to false negative ER-ICAs of FNAs were ER-ICA-low results in histologic biopsies, a prominent stroma component in these tumors, and low cellularity of FNAs. The biochemical ER values in these cases never exceeded 90 fmol/mg protein. In a minority of cases, false negative results were inexplicable.

Antibodies, Monoclonal↗

[Value of rapid biopsy studies in the intraoperative assessment of axillary lymph node involvement in breast cancer].

In a prospective, randomized trial in breast-cancer patients, the surgical procedure and the adjuvant regimen were determined intraoperatively, depending on the axillary lymph node involvement. Therefore, it was necessary to perform frozen section examinations on axillary lymph nodes. In this context it was important to analyze the value of the frozen section technique of lymph nodes in predicting axillary node involvement. In 162 patients with primary breast cancer we compared the results of the frozen sections and the paraffin histology. In 96% the intraoperative diagnosis was correct and in 4% (7 cases) the results were wrong. In 6 cases we observed a sampling error and in one case a small metastasis was misinterpreted as sinus histiocytosis. In these 7 cases less than 4 lymph nodes were examined in frozen sections and the total axillary node involvement was small (less than 4 involved nodes). There was no false positive report in this series. We conclude that frozen section examinations of axillary lymph nodes are suitable for intraoperative lymph node assessment, if at least 4 of the macroscopically most suspicious lymph nodes are observed. The final histological axillary staging (number of involved lymph nodes) has to be performed on paraffin-embedded material.

Biopsy↗

Heterogeneity of cholesterol homeostasis in man. Response to changes in dietary fat quality and cholesterol quantity.

Studies were carried out to examine the effects of dietary fat and cholesterol on cholesterol homeostasis in man. 75 12-wk studies were carried out during intake of 35% of calories as either saturated or polyunsaturated fat, first low and then high in dietary cholesterol. Dietary fat and cholesterol intakes, plasma lipid and lipoprotein levels, cholesterol absorption and sterol synthesis in isolated blood mononuclear leukocytes were measured during each diet period. In 69% of the studies the subjects compensated for the increased cholesterol intake by decreasing cholesterol fractional absorption and/or endogenous cholesterol synthesis. When an increase in plasma cholesterol levels was observed there was a failure to suppress endogenous cholesterol synthesis. Plasma cholesterol levels were more sensitive to dietary fat quality than to cholesterol quantity. The results demonstrate that the responses to dietary cholesterol and fat are highly individualized and that most individuals have effective feedback control mechanisms.

Cells, Cultured↗

Differential effect of adenosine on pre- and postsynaptic calcium fluxes.

In rat hippocampal slices, stimulus-evoked field potentials and the concomitant decrease of the extracellular concentration of free Ca ions [Ca2+]o were measured with combined reference/ion-sensitive microelectrodes. By reducing [Ca2+]o from 2.0 mM to 0.2 mM, evoked synaptic transmission was blocked, but orthodromic repetitive stimulation of CA1 afferents still elicited a marked decrease of [Ca2+]o. This Ca2+ signal is attributed predominantly to Ca2+ entry into the activated axon terminals. It was significantly depressed by adenosine. The adenosine agonist, L-phenylisopropyl adenosine (L-PIA) was more effective than D-PIA, indicating that the adenosine depression of presynaptic Ca2+ entry is mediated via the A1 receptor. 4-Aminopyridine (4-AP) enhanced decreases in [Ca2+]o without restoring synaptic transmission. Adenosine depressed also these Ca2+ signals. Adenosine deaminase was even more effective in the presence of 4-AP and enhanced the orthodromic Ca2+-signal by a factor of two. Antidromic stimulation of hippocampal pyramidal cells also evoked reductions in [Ca2+]o. These were less affected by adenosine and the other treatments under the conditions tested.

Adenosine↗

Estrogen receptor analysis on biopsies and fine-needle aspirates from human breast carcinoma. Correlation of biochemical and immunohistochemical methods using monoclonal antireceptor antibodies.

Monoclonal antibodies against estrogen receptor (ER) were used for determination of ER status immunocytochemically in histologic specimens from 192 primary breast carcinomas. All tumors were also assayed biochemically for ER with the dextran-coated charcoal method (DCC). The comparison of biochemically and immunocytochemically determined ER status showed concordant results in 80% (P less than 0.0001). In only 2 cases (1%) with low ER levels (less than 20 fmol/mg protein) immunocytochemistry failed to detect ER. ER positivity determined with a semiquantified approach based on intensity and heterogeneity of immunocytochemical staining correlated significantly with biochemically determined ER levels (P = 0.0001). In a series of fine-needle aspirates of 34 breast carcinomas sufficient cell material was available for ER immunocytochemistry (ER-ICA). Overall, the results of ER-ICA in fine-needle aspirates were concordant with ER-ICA in histologic specimens in 88% of the samples. In a few cases with weak positivity of ER-ICA in histologic specimens, ER-ICA was negative in fine-needle aspirates. In no case was there a false-positive immunocytochemical ER determination in a tumor aspirate. Thus, ER-ICA seems to be a reliable assay which can be performed in histologic and cytologic specimens.

Antibodies, Monoclonal↗

The human tumour cloning assay in the management of breast cancer patients.

A tumour cloning system was used to cultivate breast cancer specimens. Fifty-six percent of 87 samples were adequate for evaluation, showing clonal growth in about one third (35%). Effusions yielded significantly better growth than solid specimens, the median colony numbers being 64 and 18 respectively. An attempt was made to examine whether there was any association between parameters accepted as prognostic factors for breast cancer and clonal growth in vitro. No correlation was found between preoperative tumour burden, histopathologic grading, menopausal status or overall survival and clonal growth in vitro, whereas we observed an inverse trend between progesterone receptor content of the tumours and their growth potential (P less than 0.01). In those few cases where in vitro and in vivo data could be compared, a high accuracy of the predicted sensitivities was found with respect to chemotherapy, but not in relation to hormonal treatment. A statistically significant higher overall chemosensitivity was associated with the absence of oestrogen receptors (P less than 0.01).

Breast Neoplasms↗

Simultaneous and sequential determinations of steroid hormone receptors in human breast cancer. Influence of intervening therapy.

Estrogen (ER), progesterone (PgR), and androgen (AR) receptors were measured in two simultaneous or subsequent specimens taken each from 259 patients with breast cancer. We studied in 182 patients results from receptor assays, either from one tumor or from the primary tumor, and a lymph node metastasis, and in 77 sequential biopsies with or without intervening therapy. All assays were performed in a single laboratory, considering 10 fmol/mg cytosol protein bound ligand as receptor positive. The concordance rate in simultaneous ER assays was 85%; however, we found a considerable high discordance rate for PgR in primary tumor and lymph node metastasis (25%). The overall discordance rate in sequential biopsies for ER was 38% and for PgR 25%. This discordance rate was primarily dependent on the receptor quality of the first assay (ER+: 50%, ER-: 24%, PgR+: 68%, PgR-: 9%). Considering only the ER+ and PgR+ cases, we found the greatest discordance rate in the patients having endocrine treatment following the first biopsy (55% and 84%, respectively). We conclude that the receptor status of one tumor biopsy is highly representative for other tumor or lymph node biopsies. Because of the high discordance rate of primarily receptor + cases in subsequent recurrences, the receptor quality of these lesions should be analyzed whenever possible.

Biopsy↗

Enzyme activities in human breast tumor cells and sera.

Galactosyltransferase (GalTF), sialyltransferase (SiaTF), fucosyltransferase (FucTF), 5'-nucleotidase (5'Nucl), and ADP-ribosyltransferase (RibTF) were determined in three subcellular fractions of tumor cells and adjacent control tissue from 20 patients with small primary infiltrating ductal adenocarcinomas of the breast. Viable, as pure tumor cell populations as possible were isolated, subfractionated, and their enzyme levels compared to those in the patients' sera. The activities in tumor cells of the three glycosyltransferases were two- to seven-fold higher, whereas 5'-Nucl and RibTF showed reduced activities when compared to adjacent noninvolved tissue. Serum GalTF and SiaTF were slightly elevated in early mammary carcinoma, whereas FucTF, 5'Nucl, and RibTF were decreased in comparison with a control group. The proposed tumor origin of circulating enzymes could not be confirmed. Surprisingly, only for RibTF could a correlation between tumor and serum activity be established; a weak correlation was found for SiaTF. However, no such relationship could be determined for GalTF, FucTF, or 5'Nucl. In conclusion, the enzyme profile of the tumor cell does not, except for RibTF, appear in the serum. Serum enzyme profiles, therefore, do not permit detection of the early stages of breast cancer. A high correlation between RibTF activity and cytosol estrogen and progesterone receptor levels has been determined in tumor cells, possibly indicating slower growing, more differentiated types of breast tumors.

5'-Nucleotidase↗