[Laminin, a component of the basement membrane].
Explore the source record for details and available documents.
Basement Membrane↗
Biomedical subjects
R Albrechtsen
Publications and source records attributed to R Albrechtsen.
Heparan sulfate proteoglycans made by different basement-membrane-producing tumors have immunological and structural similarities.
Using immunological assays, we determined the relationship between the heparan sulfate proteoglycans produced by two different murine basement-membrane-producing tumors, i.e., the mouse Engelbreth-Holm-Swarm (EHS) tumor and the L2 rat yolk-sac tumor. Antibodies prepared against the heparan sulfate proteoglycans obtained from these two sources immunoprecipitated the same precursor protein with a molecular mass of 400,000 daltons from 35S-methionine pulse-labeled cells of both tumors. Immunohistochemistry showed the heparan sulfate proteoglycan to be distributed in the extracellular matrix and also in the native basement membrane of surrounding normal murine tissues. Blocking and ELISA assays demonstrated that the antibodies recognized both antigens. Using techniques involving the chemical and enzymatic degradation of 35S-sulfate-labeled glycosaminoglycans, the mouse EHS tumor cells were found to produce mainly heparan sulfate (75%) along with smaller amounts of chondroitin sulfate (19%), whereas the L2 rat yolk-sac tumor produced mainly chondroitin sulfate (76%) with smaller amounts of heparan sulfate (21%). We conclude that these two murine basement-membrane-producing tumors elaborate an immunologically and structurally similar type of high-molecular-weight heparan sulfate proteoglycan which subsequently becomes incorporated into basement-membrane-like material.
Animals↗
The pattern of distribution of laminin in neurogenic tumors, granular cell tumors, and nevi of the oral mucosa.
Oral tumors of presumably neuroectodermal origin were stained with anti-laminin antibody by a double layered immunofluorescence technique. A marked positive staining for laminin was found in neurofibromas and neurilemmomas although the pattern of laminin distribution was slightly different. Accentuated staining was seen in Verocay bodies. In granular cell myoblastomas (GCM), small groups of tumor cells were encircled by laminin-positive material, whereas individual tumor cells were unstained. In nevi, diffusely spread nevus cells were surrounded by a rim of laminin, whereas when arranged in nests whole groups of cells were encircled by laminin as seen in the GCM. Ordinary oral fibromas included as controls were negative except for the expected positive staining of basement membranes normally occurring in the tissues. Immunohistochemical demonstration of laminin seems to be a valuable aid in differential diagnosis of soft tissue tumors and may provide useful information about the pathogenesis of various lesions.
Basement Membrane↗
Immunochemical and ultrastructural assessment of the nature of the pericellular basement membrane of human decidual cells.
Human decidual cells of early and late pregnancy were studied immunochemically and ultrastructurally with respect to the presence and nature of pericellular basement membrane material. The most prominent cell type in decidual tissue of both early and late pregnancy were large, mature epithelioid decidual cells (greater than 25 micron) with a distinct pericellular basement membrane, containing at least laminin, type IV collagen, heparan sulfate proteoglycan, and fibronectin. Laminin was extracted from the decidual tissue at a concentration of 3 micrograms/gm as measured by enzyme-linked immunosorbent assay. Biosynthesis of laminin was shown by [35S]methionine labeling of short term organ cultures of decidual tissue followed by immunoprecipation, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and fluorography. The laminin chains migrated with the apparent molecular weights of 300 and 200 kilodaltons under reducing conditions. Two other separate populations of cells were apparent in the decidual tissue of early pregnancy. A smaller group of rounded intermediate sized (15 to 25 micron) decidual cells had focal deposits basement membrane immunoreactive material scattered at the cell surfaces. Ultrastructurally, clumps of electron dense basement membrane material were present in close vicinity to the cell membrane. Occasional populations of small (greater than 15 micron) elongated fibroblastic-like cells were identified which did not display any immunoreactivity for any of the investigated basement membrane components. The two latter populations of decidual cells were not observed in the decidual tissue investigated from the placental bed of late pregnancy. It is suggested that these three types of decidual cells might represent various stages of the sequential differentiation of stromal cells into decidual cells of the pregnant endometrium. Predecidualization of the human endometrium, which is seen in the late secretory phase of the normal menstrual cycle and in some states of hyperplasia, was also shown to be accompanied by the presence of deposits of laminin-positive material at the cell surfaces. In the latter case, these cells resembled the intermediate sized decidual cells of the pregnant endometrium. In conclusion, the results suggest that the process of decidualization and predecidualization can be characterized morphologically and immunochemically by the accumulation of basement membrane material in specific decidua cell subpopulations.
Adult↗
Basement membrane heparan sulfate proteoglycan from the L2 rat yolk sac carcinoma.
Heparan sulfate proteoglycan from the L2 rat yolk sac carcinoma has been purified and partially characterized. The proteoglycan has an apparent Mr of 750 000, 35% of which represents the core protein. The core protein seems to be homogeneous, whereas the heparan sulfate chains are heterogeneous with an Mr of about 50 000-70 000, with 30% of the glucosamine being N-sulfated. Antibodies raised against the core protein of the heparan sulfate proteoglycan reacted with basement membranes of various rat and human tissue.
Amino Acids↗
Human laminin isolated in a nearly intact, biologically active form from placenta by limited proteolysis.
A protein with properties of laminin has been isolated from human placental extracts by using monoclonal antibodies. Placental tissue was extracted with 0.5 M NaCl and high molecular weight proteins were isolated from the extract by salt precipitation and gel filtration on Sepharose 6B. The resulting protein fraction which contained material cross-reactive with anti-sera to rat laminin was used as immunogen to prepare hybridomas. Thirteen hybrids produced antibodies which reacted with basement membrane-associated antigens in indirect immunofluorescence of tissues. One of these, 4E10, was characterized in detail. This monoclonal antibody reacted with human laminin as shown by several lines of evidence. Immunoprecipitation from metabolically labeled culture media of a human amniotic epithelial cell line with the 4E10 antibody followed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed polypeptides with Mr similar to those of rat laminin. Immunochromatography of placental extracts obtained by limited pepsin digestion yielded material with main polypeptides at 160 and 130 kilodaltons in sodium dodecyl sulfate-polyacrylamide gel electrophoresis after reduction. These peptic fragments cross-reacted with rat laminin in immunodiffusion and enzyme immunoassay, and a polyclonal antiserum against the fragments reacted with basement membranes in tissues in a manner identical with the 4E10 antibody. Electron microscopic images of the human peptic fragments showed structures similar to the cross-shaped images of murine laminins, although the short arms were truncated to various degrees or even absent. The isolated peptic fragments also displayed biological activity similar to that of murine laminins in that the outgrowth of neurites by neuronal cells was promoted on plates coated with the fragments.
Antibodies, Monoclonal↗
The basement membrane component laminin in breast carcinomas and axillary lymph node metastases.
The occurrence of the basement membrane (BM) glycoprotein laminin was investigated in 91 malignant breast tumors and in 359 axillary lymph nodes of which 70 contained metastases. The indirect double-layer immunoperoxidase technique was applied using rabbit anti-rat laminin. Positive cytoplasmic staining for laminin was found in all breast carcinomas. BM could be demonstrated around in situ carcinomas and in the higher differentiated carcinomas around islands of infiltrating tumor cells. Lymph node metastases resembled the primary tumors in the cytoplasmic staining reaction for laminin, but no BM staining was found. Tissue from 50 benign breast lesions showed cytoplasmic staining for laminin in both the secretory and the myoepithelial cells, but consistently weaker than in the carcinomas. BM was always present.
Adolescent↗
[Alpha-fetoprotein and human chorionic gonadotropin as tumor markers in intracranial and intraspinal germ cell tumors].
Explore the source record for details and available documents.
Adolescent↗
Carcinoma in situ of the testis. Some ultrastructural characteristics of germ cells.
The two cytoplasmic organelles, dense-cored vesicles and "nuages" have been considered to allow positive identification of primordial germ cells in rodents, but no use of these potential markers has been applied to human material. We have observed dense-cored vesicles and "nuages" in the abnormal germ cells of carcinoma in situ of the testis and thus brought further evidence for the germ cell origin of this lesion. These organelles may be useful cytoplasmic markers in the study of germ cell tumors.
Adult↗
Laminin, a noncollagenous component of epithelial basement membranes synthesized by a rat yolk sac tumor.
Laminin, a glycoprotein antigenically similar or identical to a component of epithelial basement membranes, was identified as a major component of the abundant extracellular matrix synthesized by an experimentally induced rat yolk sac tumor. Immunocytochemical staining revealed laminin in cultured tumor cells as well as in their extracellular matrix. The presence of soluble laminin in the culture media of the tumor cells was demonstrated using metabolic labeling followed by identification by immunoprecipitation and sodium dodecyl sulfate:polyacrylamide gel electrophoresis. This revealed two polypeptides with molecular weights of approximately 200,000 and 400,000. These comigrated with the polypeptides of mouse laminin isolated previously. The yolk sac tumor tissue grown in vivo contained laminin in the tumor cells and in the extracellular material as evidenced by immunofluorescence and immunoperoxidase staining. Immunization with the tumor matrix resulted in an antiserum that contained antilaminin and natifibronectin and was made specific for laminin by absorption with fibronectin. This antiserum precipitated laminin polypeptides from culture medium of yolk sac tumour cells and stained basement membranes in rat tissues in a manner indistinguishable from antilaminin. The presence of laminin in rat yolk sac cells, the presumed origin of our yolk sac tumor, was studied in some detail. Laminin was found to be present in normal cells of the visceral as well as the parietal yolk sac layer and in their basement membranes suggesting, but not proving, that both types of cells have ability to synthesize laminin. Production of laminin and the presence of laminin-containing basement membrane material may be important for the biological behavior of the yolk sac tumor. This tumor will also be a useful source of laminin for chemical and biological characterization of this basement membrane protein.
Animals↗
Basement membrane changes in breast cancer detected by immunohistochemical staining for laminin.
The distribution of the basement membrane glycoprotein laminin was studied by the immunoperoxidase technique in benign and malignant human breast tissue and in axillary lymph nodes from patients with breast cancer. An antiserum prepared against rat laminin was used. The specificity of this antiserum against human laminin was studied using the FL cell line of human epithelial-like cells derived from normal amniotic membrane. The antiserum reacted with these cells in immunoperoxidase staining and precipitated metabolically labeled secreted polypeptides which comigrated with polypeptides with molecular weights of 400,000 and 200,000 of rat laminin in sodium dodecyl sulfate:polyacrylamide gel electrophoresis. The neoplastic cells in malignant breast tissues showed strong cytoplasmic staining for laminin, and a positive reaction was aslo found in lymph node metastases. In some cases in which only micrometastases were present, these cells also stained strongly for laminin. In nonmalignant breast tissues, the epithelial cells of the duct were positive for laminin, but the staining was weaker than in the carcinomas. Pretreatment of the fixed tissue sections with trypsin markedly enhanced the staining of basement membranes for laminin. In trypsin-treated sections of normal breast tissue and benign lesions, the laminin staining delineated continuous basement membranes. In carcinomas representing the more differentiated types, basement membranes presumably produced by the tumor cells could be revealed by laminin staining, but they were thinner and discontinuous. The poorly differentiated carcinomas lacked organized basement membranes detectable by laminin staining. Our studies suggest that staining for laminin may be a useful adjunct test for detection of micrometatases in lymph nodes. The correlation of disintegration of the laminin-containing basement membranes of tumors with increasingly anaplastic appearance supports the notion that basement membranes may play a role in tumor invasion.
Basement Membrane↗
Immunohistochemical demonstration of a hitherto undescribed localization of hemoglobin A and F in endodermal cells of normal human yolk sac and endodermal sinus tumor.
In this study of 4 human yolk sacs, the presence of hemoglobin A and F (HbA and HbF) is demonstrated for the first time in epithelial cells (type 1) and erythroid-like cells (type 2) in the endodermal layer by immunoperoxidase technique. Our findings strongly support the hypothesis previously proposed that the red blood cells formed in the yolk sac are of endodermal origin. Tumor with yolk sac differentiation (8 endodermal sinus tumors and 1 embryonal carcinoma with vitelline areas) similarly showed HbA and HbF localisation in endodermal cells. None of 59 germ cell tumors of other types contained these hemoglobins in the neoplastic cells.
Endoderm↗
Granular cell myoblastoma in the parotid gland.
Granular cell myoblastomas develop most commonly in the head and neck region, but their occurrence in the salivary glands has been reported in only one case, in the submaxillary gland. The authors report a case of granular cell myoblastoma in a previously undescribed localization, the parotid gland.
Female↗
Carcinoma of the parotid gland following sialography with thorotrast. Report of two cases.
Two cases are presented of malignant tumour of the parotid gland following sialography with Thorotrast, 28 and 45 years previously. Both cases were histologically established as squamous cell carcinoma and the presence of Thorotrast in the tumours was confirmed by autohistoradiography. It is suggested that the tumours may have developed from metaplastic ductal epithelium after many years of exposure to the alpha radiation from Thorotrast deposits in the gland.
Autoradiography↗
Alpha-fetoprotein and human chorionic gonadotropin in a patient with a primary intracranial germ cell tumor.
A 17 year old man with a primary intracranial germ cell tumor in the pituitary region is reported. Both serum alpha-fetoprotein (AFP) and serum human chorionic gonadotropin (hCG) were found elevated preoperatively. Normal levels of serum AFP and hCG were found after operation and radiotherapy. By indirect immunofluorescence staining of the tumor tissue a slight staining for AFP was localized to the endodermal vesicles, whereas a more intensive staining for hCG could be identified in the giant cells.
Adolescent↗
High densities of benzodiazepine receptors in human cortical areas.
Explore the source record for details and available documents.
Adolescent↗
Parathyroid adenomas induced by radiation.
Explore the source record for details and available documents.
Adenoma↗
The pathogenesis of acute selective necrosis of the granular layer of the human cerebellar cortex.
PH determinations by means of a sturdy, spear-electrode inserted in the cerebellar tissue immediately after necropsy were carried out in 60 patients suffering from different disorders and dying in hospital, and from 25 individuals killed instantly by violent accidents. A correlation was found between the presence of NGL and low pH levels in the cerebellum (average pH 5.56); subjects without NGL changes showed an average pH OF 6.08. No correlation was found between the pH levels and the time after death, or between pH and any specific disease. The so-called acute selective necrosis of the granular layer of the human cerebellar cortex (NGL), is considered from the present studies to be a phenomenon of postmortem origin. Its relationship to certain specific diseases can be explained by the fact that in these conditions there is a higher postmortem acidity, known to promote autolysis.
Aged↗