Search PubMed⌕ Search

Biomedical subjects

M Kan

Publications and source records attributed to M Kan.

At least 127 records · Page 7Linked to original sources
PubMed1986

A weaker gelatin-binding affinity and increased glycosylation of amniotic fluid fibronectin than plasma fibronectin.

Human amniotic fluid fibronectin had different carbohydrate moieties from plasma fibronectin. Nearly 90% of glycopeptides released from amniotic fluid fibronectin was not bound by concanavalin A-Sepharose, whereas 75% of glycopeptides from plasma fibronectin was bound. Amniotic fluid fibronectin showed a significantly lower gelatin-binding affinity than plasma fibronectin at 25 degrees C. When the incubation temperature was lowered to 4 degrees C, no significant difference in this activity was found. Cell-attachment promoting activity of the two fibronectins was not significantly different.

Amniotic Fluid↗
PubMed1986

Establishment of six human pancreatic cancer cell lines and their sensitivities to anti-tumor drugs.

Six human pancreatic cancer cell lines PK-1, -8, -9, -12, -14 and -16, were established. They originated from either primary pancreatic cancer biopsy or liver metastasis biopsy, or xenografts of these biopsy specimens in athymic nude mice. The primary tumors were all well differentiated adenocarcinomas of pancreatic duct origin. The six established PK cell lines were all CEA positive and had tumorigenicity in athymic nude mice. Morphology of the xenografted tumors was closely similar to that of the original tumor. PK cells grew slowly with the doubling time of 41.3 to 82 hr and showed aneuploid chromosome pattern. High levels of glucose-6-phosphate dehydrogenase (G6PDH) and lactic dehydrogenase (LDH) were found in each cell extract. Trypsin was not detected in cell extracts except PK-8 and PK-9. In chemosensitivity test, all of PK cell lines were sensitive to aclacinomycin A (ACM), and PK-1 and PK-8 were sensitive to 5-Fluorouracil (5-Fu) at concentrations of 0.02 microgram/ml, ACM and 1 microgram/ml, 5-Fu, when the drugs were used for over 48 hr. At higher concentrations, they showed time independent sensitivity to mitomycin C (MMC). PK-9 was resistant to 5-Fu and MMC.

Adenocarcinoma↗
PubMed1986

Orosomucoid as the accelerator of hepatic fibrosis.

The administration of orosomucoid to rats with chronic liver injury accelerated hepatic fibrosis. An increase of hepatic fibres was seen histologically and the content of hydroxyproline in the liver collagen fraction increased. Moreover, the incorporation of 3H-proline into the collagen fraction of injured liver was increased by the administration of orosomucoid.

Animals↗
PubMed1985

Fibroblast products adsorb to the culture substrate and stimulate growth of human umbilical vein endothelial cells.

Human umbilical vein endothelial cells grew with a doubling time of approximately 20 hr in medium conditioned by human diploid fibroblasts and supplemented with 10% fetal bovine serum, whereas the cells did not grow substantially in the non-conditioned serum supplemented medium. Production of the fibroblast-derived activity required the presence of insulin, EGF, or PDGF. The fibroblast derived-factor adsorbed to native culture dishes or dishes coated with gelatin and collagen. The adsorbed activity was resistant to treatment with 1% Triton X-100, and was abolished by treatment with serine proteases. Further, the extracellular matrix produced by the fibroblasts also showed growth-stimulating activity. Fibroblast-derived factors may play a role in vascularization processes during wound healing, inflammation and normal development.

Adsorption↗
PubMed1985

Long-term serial cultivation and growth requirements for human umbilical vein endothelial cells.

Human umbilical vein endothelial cells (HUV-EC) grew rapidly in vitro in medium supplemented with epidermal growth factor, fetal bovine serum (FBS) and human diploid fibroblast-conditioned medium. The effect of FBS could be replaced partially by bovine serum albumin, cholesterol, and vitamin E, and completely by further addition of serum dialysate or refeeding every other day. Among these components, fibroblast-conditioned medium is essential for HUV-EC growth. The HUV-EC were cultured serially for over 50 population doublings in the 10% FBS containing fibroblast-conditioned medium and for over 40 population doublings in the serum-free medium. Mitogenic factor(s) present in the medium conditioned by fibroblasts may be related to endothelial cell growth factor and play an important role in angiogenesis and regeneration of vascular endothelium in vitro.

Cell Division↗
PubMed1984

Characterization of fibronectin from fetal human plasma in comparison with adult plasma fibronectin.

Fibronectin was purified from fetal human plasma and characterized in comparison with fibronectin from adult human plasma. Fetal plasma fibronectin had an amino-acid composition, immunological properties, and cell-attachment-promoting activity similar to those of adult plasma fibronectin. However, fetal plasma fibronectin was shown to have a distinct carbohydrate composition which is characterized by the presence of fucose. To ascertain the differences in the carbohydrate moiety, 14C-labeled glycopeptides were prepared and sequentially analyzed with columns of immobilized concanavalin A and lentil lectin. Glycopeptides from fetal plasma fibronectin contained a population of glycopeptides which bound to both lectin gels. Almost all of the glycopeptides in this population lost their ability to bind to lentil lectin upon fucosidase digestion, indicating that fetal plasma fibronectin possesses a substantial amount of fucosylated biantennary glycans. In contrast, glycopeptides from adult plasma fibronectin practically lacked such glycopeptides. Another difference observed was that fetal plasma fibronectin had a larger amount of concanavalin A-unbound glycopeptides than did adult plasma fibronectin. These results indicate the presence of age-related variation in glycosylation of human plasma fibronectin.

Adult↗
PubMed1984

Ferritin-bearing lymphocytes in the diagnosis of breast cancer.

Four hundred forty-seven women attending a breast clinic because of either suspicious lesions, anxiety about breast cancer, follow-up after the removal of a benign breast lesion, or a family history of breast cancer had a routine test for percentage of ferritin-bearing lymphocytes ( FBL ) in their peripheral blood. Among patients who received surgery following physical examination in the clinic and/or mammography, the test was positive in 40 of the 45 (89%) with Stage I;II carcinoma, 3 of 3 with Stage IV carcinoma, and only in 29 of the 97 (37%) with benign breast disease. The possible reasons for the poorer detection rate in Stage III carcinoma are discussed. The test, however, identified 2 cases of Stage I carcinoma, 1 of breast lymphoma, and 12 with premalignant lesions in those who were found normal on physical examination and mammography. Ferritin-bearing lymphocyte results tended to become negative after surgical removal of the lesion, and became positive on recurrence of the tumor and appearance of metastases. The detection rate was maximized by combining the FBL test with the clinical modes of detection.

Adult↗
PubMed1984

Further characterization of porcine plasma fibronectin which contains fucosylated carbohydrate chains.

Porcine plasma fibronectin and its functional four fragments produced by cathepsin B digestion were examined for biological, immunochemical and biochemical properties. Native fibronectin, 150-kDa and 130-kDa fragments exhibited similar cell attachment-promoting activity to each other. In an Ouchterlony double immunodiffusion system, these three polypeptides formed a precipitin line with anti-fibronectin antiserum, while the 50-kDa and 30-kDa fragments did not. The 150-kDa and 130-kDa fragments contained free sulfhydryl(s). The glycopeptide fractions were prepared by pronase digestion of porcine and human plasma fibronectin, and radiolabeled with [14C]acetic anhydride. The results of affinity chromatography with concanavalin A and lentil lectin immobilized on agarose indicated that the porcine glycopeptide fraction was different from the human fraction in that a larger part (58%) of the former was bound to lentil lectin. About 90% of this lentil lectin-reactive glycopeptides lost this reactivity upon alpha-L-fucosidase digestion. The glycopeptide fractions were also prepared from three carbohydrate-containing domains. Less than 30% of the radioactivity of the glycopeptide fractions of 150-kDa and 130-kDa fragments was retained on the lentil lectin-agarose, while about 90% of that from the 50-kDa fragment was retained. These results indicate that porcine plasma fibronectin has characteristics very similar to those of human plasma fibronectin and others, but is unique in that it contains fucosylated carbohydrate chains which unevenly distribute through functional domains.

Animals↗
PubMed1984

Biochemical and immunochemical comparison of fibronectin and polynectin from porcine plasma.

Polynectin, a glycoprotein of porcine blood plasma (also known as glycine-rich gelatin-binding protein (Isemura, M., Sato, N., and Yosizawa, Z. (1982) J. Biol. Chem. 257, 14854-14857] is similar to fibronectin with respect to binding characteristics to affinity gels. However, no immunoprecipitation reaction was observed either between polynectin and anti-fibronectin antiserum, or between fibronectin and anti-polynectin antiserum prepared in the present experiments. No cross-reaction was found between fibronectin and polynectin by enzyme-linked immunosorbent assays. Immunohistochemical studies revealed the presence in abundance of polynectin in intestinal and gastric glands. It was found that the pattern of distribution of polynectin was entirely different from that of fibronectin. Polynectin, in contrast to fibronectin, exhibited no cell attachment-promoting effects on BHK-21, a baby hamster kidney cell line, and a cell line of human embryonic lung fibroblasts. In addition, changes in binding characteristics to affinity gels after reduction and alkylation differed between polynectin and fibronectin. Although both proteins appear to have similar carbohydrate chains in view of the similar reactivities with lectins, the results of the present experiments demonstrated that polynectin is entirely different from fibronectin.

Alkylation↗
PubMed1984

Effects of ferrous iron and transferrin on cell proliferation of human diploid fibroblasts in serum-free culture.

Iron-free RITC 80-7 defined medium was used to examine effects of ferrous iron and transferrin on cell proliferation of human diploid fibroblasts. Both ferrous iron and holo-transferrin stimulated cell proliferation in the medium, but apotransferrin did not. When 5 g/l human serum albumin (HSA) was added to the defined medium, excellent growth was obtained under hypoxic conditions, whereas a reduction of cellular growth during the culture periods was observed under aerobic conditions. When ferrous iron was added to the HSA medium alone, the reduction in growth increased in proportion to the concentrations, whereas the addition of transferrin prevented this reduction in a concentration-dependent manner. This suggests that the ferrous iron concentration in media causes a reduction in growth under aerobic conditions and transferrin prevents this reduction because it decreases the ferrous iron concentration. Further, serum albumin seems to be a source of iron in media.

Aerobiosis↗
PubMed1984

Isolation and characterization of human placenta fibronectin.

Fibronectin was isolated from human placenta tissues and compared with human plasma fibronectin. Placenta and plasma fibronectins had similar amino acid compositions, immunological properties, and cell attachment-promoting activities, but differed in apparent molecular weight on sodium dodecyl sulfate-polyacrylamide gel electrophoresis, which could be accounted for at least partly by the difference in carbohydrate composition. Unlike plasma fibronectin, placenta fibronectin failed to form a precipitin line with concanavalin A in a double diffusion system. The non- or low-reactivity of placenta fibronectin with this lectin was also demonstrated by affinity chromatography with concanavalin A-agarose, in which more than 90% of the radiolabeled glycopeptides derived from placenta fibronectin was not retained on the gel. The two fibronectins also differed in the reactivity with Lens culinaris agglutinin of their glycopeptide fractions. These data indicate that placenta and plasma fibronectins are different in their carbohydrate structures and, therefore, suggest the presence of a tissue- or cell-specific mechanism for processing the carbohydrates of this glycoprotein.

Amino Acids↗
PubMed1984

Primary culture of human esophageal epithelial cells.

Primary cultures and serial passages of nontumorous adult human esophageal epithelial cells derived from surgically resected esophagi of patients with esophageal cancer have been developed. Disaggregated cells obtained by means of tryptic digestion lasting for 90 min grew to confluency in medium RITC 80-7 supplemented with 10% fetal bovine serum (FBS). Such primary cultures were established from more than 20 donors, and could be passaged 3 to 5 times. Fibroblastic contamination was almost eliminated by careful sampling, and it was possible to perform the growth response or serial passages without fibroblastic overgrowth. Serum-free medium RITC 80-7 supplemented with fibronectin (FN) and bovine serum albumin (BSA) also supported the growth of esophageal epithelial cells, but was not sufficient for serial passages. Among growth promoting factors in medium RITC 80-7, the epidermal growth factor (EGF) was highly stimulatory to growth. Insulin, transferrin, FN and BSA also enhanced cell growth and/or attachment. The epithelial nature of the cultured cells was confirmed by transmission electron microscopy and indirect immunofluorescent staining with antikeratin antibody. The majority of the cultured cells were diploid.

Adult↗
PubMed1984

Establishment of a human pancreatic cancer cell line and detection of pancreatic cancer associated antigen.

We succeeded in an establishment of a human pancreatic cancer cell line (PK-1) from liver metastasis of pancreatic cancer. Primary pancreatic cancer cells grew as islands surrounded by fibroblastic cells. However, these fibroblastic cells were gradually omitted by the polygonal shaped cancer cells. This cell line contained neither zymogen granules nor trypsin indicating that this pancreatic cancer originated from pancreatic duct cells. Modal chromosome numbers of this cell line were 42 and 72 and the doubling time was 48 hr. This cell line was transplantable in athymic nude mice to form progressive tumors which had histology similar to that of the original cancer (papillotubular adenocarcinoma). Neither AFP nor ferritin but CEA was detected on the surface and in the cytoplasm of this cell line in indirect immunofluorescence. Rabbit antiserum against this pancreatic cancer cell line detected pancreatic cancer associated antigen besides CEA in the culture supernatant. This antiserum reacted with sera from patients with pancreatic cancer to form a distinct precipitin line in agarose gel which fused with the precipitin line formed between the culture supernatant of this cell line and the antiserum.

Animals↗