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Biomedical subjects

A Rejthar

Publications and source records attributed to A Rejthar.

At least 55 records · Page 3Linked to original sources
PubMed1988

Occurrence of carcinoembryonic antigen in tumor tissue and serum of breast cancer patients.

In 116 breast cancer patients, the levels of carcinoembryonic antigen (CEA) were determined before operation in the serum using RIA, and after operation in sections of breast tumor tissue using the immunohistological PAP technique. CEA circulating in the serum was found in 49 patients (42%). Elevated values (over 10 micrograms/l) were found in only 12 patients (10%). In histological specimens CEA positivity was found in 94 tumors (81%), however, in a majority of them the number of positive cells per section was low (1-10%). A comparison of positive and negative findings both in the serum and in the tumor specimens of individual patients showed that both serum and tumor sections were CEA positive in 40 patients (35%) and both localizations were CEA negative in 13 patients (12%). Although most patients had positive histological sections but negative sera (46%). Only 7% of patients had negative sections and positive sera. In 41 patients CEA could be examined both qualitatively (immunohistologically), and quantitatively in the cytosol of the same homogenized tumor. Of them, 30 patients (72%) had in the cytosol a CEA concentration exceeding 5 micrograms/g proteins, in 11 of the 41 patients (28%) no CEA was found. Immunohistological examination of CEA in this group gave positive results in 35 out of the 41 patients (85%), and only 6 tumors (15%) were completely negative. CEA was shown to be present in each histological type of the tumors studied, invasive ductal tumors being slightly more frequent and more positive than the lobular ones. No relation was observed to the structure of the tumors, nor to the degree of their differentiation. Thus, the examination of CEA levels can hardly contribute to the improvement of histological classification.

Adenocarcinoma↗
PubMed1987

Expression of HLA-DR antigens on tumour cells does not contribute to skin reactivity to autologous cholesteryl hemisuccinate (CHS)-treated tumour cells in patients with metastatic melanoma.

Skin tests with autologous cholesteryl hemisuccinate (CHS)-treated and untreated cells were performed in ten metastatic melanoma patients. In the majority of cases evident reaction was noted with CHS-treated cells (9/10) while the reaction with untreated cells was mostly negative (7/10). Tumour cell suspensions used for skin tests were characterized for reactivity with monoclonal antibody TAL 1B5 detecting the HLA-DR alpha chain. There were no differences between CHS-treated and untreated cells with respect to HLA-DR expression and no correlation was found between grade of skin reaction to CHS-treated cells and the proportion of HLA-DR positive cells in the injected cell sample.

Antigens, Neoplasm↗
PubMed1987

Lack of beta-casein production by human breast tumours revealed by monoclonal antibodies.

An immunohistochemical study with four monoclonal antibodies to human beta-casein was carried out to examine the expression of this milk protein in a wide range of normal tissues, in 127 breast tumours and in a heterogeneous panel of 42 malignancies of other histogenesis. The only normal tissue stained positively by the antibodies was the mammary gland in late pregnancy, during lactation and in the post-lactational regression period. None of the tumours of non-mammary origin showed any staining. Furthermore, only two of 40 benign breast lesions and one anaplastic primary carcinoma with its metastasis (among 87 breast carcinomas) showed any reactivity. The immunohistochemical results were supported by immunoblotting data and suggested beta-casein expression has no role to play as a marker in the diagnosis or monitoring of human breast cancer.

Antibodies, Monoclonal↗
PubMed1987

HLA-DR antigens on differentiating human mammary gland epithelium and breast tumours.

The staining pattern of a monoclonal antibody directed to the monomorphic determinant of HLA-DR antigens was examined on sections of human mammary gland tissues at various stages of differentiation as well as on 50 benign and 72 malignant breast lesions. Normal resting breast epithelium lacked HLA-DR, whereas late-pregnant and lactating epithelia expressed high levels of HLA-DR antigens, followed by a decline in the post-weaning regression period. Most benign breast lesions revealed heterogeneous staining ranging from very few up to 20-25% positive epithelial Greater variability was observed among carcinomas, where a small group (approximately 7%) of cases showing 40-95% positive tumour cells was found, in addition to negative tumours and those with the minority of HLA-DR expressing carcinoma cells. The density of the leukocytic infiltrate was higher in carcinomas than in either normal breast tissue or benign lesions, the HLA-DR phenotype of the mononuclear infiltrating cells lacking any obvious correlation with the HLA-DR status of the epithelial component. Immunoblotting analyses of whole-tissue lysates separated by SDS-PAGE confirmed the immunohistochemical data and demonstrated the reactivity with only one protein band predicted for HLA-DR alpha-chain. The combination of immunohistochemistry and autoradiography on sections of human reduction mammoplasty organoids cultured in collagen gels and labelled with tritiated thymidine revealed a lack of HLA-DR expression on proliferating breast epithelial cells suggesting factors other than cell kinetics must be responsible for induction of HLA-DR antigens seen in pregnant and lactating breast epithelium and some tumours.

Antibodies, Monoclonal↗
PubMed1987

Differentiation patterns of testicular germ-cell tumours as revealed by a panel of monoclonal antibodies.

A panel of monoclonal antibodies against different keratin polypeptides, epithelial glycoproteins, placental alkaline phosphatase and collagen type IV was used to evaluate immunohistochemically the expression of the target antigens in 30 different human testicular germ-cell tumours of various types. Antikeratin antibodies detecting markers of different routes of epithelial differentiation revealed remarkable similarity of differential expression of various keratins in epithelial structures of teratomas and combined tumours as compared with normal human epithelial tissues. A considerable proportion of embryonal carcinoma cells stained positively for keratins 8, 18 and 19, while a minor subpopulation of tumour cells in embryonal carcinomas, some seminomas and many atypical intratubular cells expressed keratins 8 and 18 but usually lacked keratin 19. Antibody RICEO-MFG-06.3, specific for epithelial glycoproteins, gave negative results with seminomas as opposed to positivity in all but two nonseminomatous tumours. All but two neoplasms showed positivity for placental alkaline phosphatase, thus supporting its reliability as a marker of germ-cell tumours. It is concluded that the monoclonal antibody RICEO-MFG-06.3 and especially the keratin-19-specific antibodies BA16 and BA17 can be helpful in distinguishing embryonal carcinoma from seminoma and, together with antibodies to other keratins, in the study of the origin and histogenesis of testicular germ-cell tumours.

Alkaline Phosphatase↗
PubMed1987

Heterogeneity of lymphocytic colonies in agar culture.

Cytochemical methods and electron microscopy were employed to examine lymphocytic colonies grown in semisolid media for the presence of a heterogeneous cell population consisting mainly of T lymphoblasts with an admixture of B-series elements and monocytoid-macrophagic cells.

Agar↗
PubMed1986

Differential expression of keratin 19 in normal human epithelial tissues revealed by monospecific monoclonal antibodies.

Three monospecific monoclonal antibodies (BA16, BA17 and A53-B/A2) recognizing different epitopes of the human keratin 19 were used to determine tissue distribution of this 40 kDa keratin polypeptide. Immunohistochemical methods revealed four different staining patterns among normal human epithelial tissues: firstly, complete negativity of the epidermis, sebaceous glands, hepatocytes and other tissues; secondly, homogeneous positivity as seen for example in the gall bladder and urinary bladder epithelium, endometrium and many other epithelia; thirdly, a mosaic of positive and negative cells among mammary gland luminal cells, prostate epithelia and some other epithelia and fourthly, a more complex heterogeneous pattern found in non-keratinizing squamous epithelia and hair follicles with generally the basal layer being the most strongly or sometimes exclusively stained. The pattern seen in non-keratinizing squamous epithelia varied considerably according to the fixation method and the antibody used as well as among different donors and in different areas of the same organ. The other three staining patterns were on the other hand nearly identical with all three antibodies on both frozen sections and sections of methacarn-fixed paraffin-embedded tissues. Our results provide evidence for differential expression of the human keratin 19 at the single cell level, an observation which could be exploited in the study of epithelial differentiation and pathology.

Antibodies, Monoclonal↗
PubMed1986

Expression of monoclonal antibody-defined epitopes of keratin 19 in human tumours and cultured cells.

The monoclonal antibodies BA16 and BA17, reacting specifically with human keratin 19 (40 kD) have been tested by immunohistochemical staining methods for their reaction with a wide range of human tumours and cultured cells. Primary adenocarcinomas and their metastases showed a homogeneously positive reaction with greater than 95% of the tumour cells staining. Non-epithelial tumours, basaliomas and squamous cell carcinomas were unstained, while benign breast lesions and a thyroid adenoma show a mosaic pattern of stained and unstained (5-40%) cells. These three staining patterns were also seen in cultured cells. Positive homogeneous staining was seen in all breast cancer cell lines examined with the exception of PMC42, which exhibits stem cell characteristics, and which showed the heterogeneous pattern of staining seen in milk cell cultures. Non-epithelial lines and strains, two cell lines from cervical carcinomas and three SV40 transformed breast epithelial lines were unstained. The antibodies BA16 and 17 are potentially useful reagents for distinguishing adenocarcinomas (and their metastases) from non-epithelial tumours and from squamous carcinomas. They may also discriminate between benign and malignant breast lesions, and identify a specific differentiation phenotype in the secretory cell lineage.

Antibodies, Monoclonal↗
PubMed1985

Skin tests with autologous cholesteryl hemisuccinate treated tumour cells in cancer patients.

Skin tests with autologous irradiated tumour cells were performed in 20 malignant melanoma, 7 breast and 6 ovarian cancer patients. In the majority of cases evident reaction was noted with cholesteryl hemisuccinate (CHS)-treated cells while the reaction with untreated cells was mostly negative. No correlation was found between this reactivity and the ability of patients to be sensitized to DNCB and to their reactivity to PPD. No correlation was found between reactivity to CHS-treated tumour cells and the stage and course of the disease.

Breast Neoplasms↗
PubMed1985

Isolation of two transforming viruses from sarcomas obtained in chickens inoculated intraembryonally with a transformation defective mutant of Prague strain Rous sarcoma virus.

Sarcomas appeared after long latency with a frequency of about 2% in Brown Leghorn and (CB X IC)F1 chickens after intraembryonic and neonatal inoculation of transformation-defective mutants of ASVs subgroup C. Only the freshly isolated td mutants, td daPR-C and td daPR-C morphf, exhibited the tumorigenic activity, whereas the standard td mutants induced no sarcomas. Two (862 and 2257) out of four tumours could be transplanted in young chickens and produced low titres of transforming virus. The other two tumours were not transplantable and devoid of any transforming virus. Viruses 862 and 2257 are clearly defective in replication, virus 2257 cannot be complemented efficiently by any helper virus in vitro. The low titre of virus 2257 is not caused by interference with a helper virus of the same subgroup specificity. Both viruses are highly tumorigenic in vivo.

Animals↗
PubMed1984

Biochemical and histochemical characteristics of target antigen detected by monoclonal antibody HBCA-12 against a membrane component of human mammary carcinoma cell line.

Monoclonal antibody HBCA-12 obtained by hybridoma procedure after immunization with human mammary adenocarcinoma cell line MDA-MB-231 immunoprecipitated a cell surface sialoglycoprotein gp80 (apparent molecular weight 80 000) from MDA-MB-231 cells and a glycoprotein gp78 from human myeloma cell line ARH 77. A protein of a similar electrophoretic mobility was immunoprecipitated also from 35S-methionine metabolically radiolabeled human melanoma cell line VUP 1. The expression of the antigen recognized by HBCA-12 monoclonal antibody could be detected neither on PHA-induced nor on EBV-transformed peripheral blood mononuclear cells from healthy donors.

Adenocarcinoma↗
PubMed1981

Alterations of plasma levels in malignant lymphoma.

Fibrinogen levels were investigated in the plasma of a group of patients with malignant lymphoma consisting of M. Hodgkin's and non-Hodgkin's lymphoma, and were found to be significantly higher in an acute onset of the disease and in relapses, than in a control group of healthy blood donors. In the terminal stages, fibrinogen levels in the plasma were observed to decline towards the upper normal limits. Plasma fibrinogen levels are considered to be a good indicator of the activity of the disease.

Adolescent↗