首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
Summary The expression of antigens on 33 human melanoma cells obtained directly from surgically excised tumours was investigated by means of antibody-dependent cell-mediated cytotoxic assays. Antisera used in the study were two antisera from human melanoma patients against different tumour-associated antigens on melanoma cells and antisera against carcinoembryonic antigen (CEA) and 2 microglobulin (2M). Considerable heterogeneity was observed in the expression of both melanoma-associated and non-melanoma antigens on melanoma cells from 33 different patients.Patients whose tumours were reactive with the melanoma-associated antiserum (CHI) had a significantly longer remission period to stage 2 melanoma. The period to development of stage 3 melanoma also appeared longer, but this was not statistically significant with the number of patients available for study. The expression of CEA, 2M, and the tumour-associated antigen TIN was not significantly related to the recurrence-free interval. There appeared to be a reciprocal expression of the two melanoma-associated antigens, and patients with tumours expressing CHI but not TIN had a significantly longer recurrence-free interval than patients whose tumours had the opposite antigenic pattern.In the limited number of patients available for study the expression of the antigen CHI did not appear related to thickness of the primary tumour or to immune response of the patients to melanoma cells in leucocyte-dependent antibody and natural killer cell assays. Although the nature of the association between expression of this antigen and longer remission-free period is unknown these results suggest that the expression of certain melanoma antigens on the cell surface may be an important additional variable which has prognostic and therapeutic importance.  相似文献   

2.
Summary Administration of interferon as a single therapeutic regimen in cancer patients with various neoplasias has had only limited efficacy in ameliorating the negative clinical course of their disease. In the present study, we have evaluated the effect of recombinant human fibroblast (IFN) and immune (IFN) interferon, alone and in combination, on growth, differentiation and the expression of class I and II histocompatibility locus antigens (HLA) and melanoma-associated antigens on the human melanoma cell line H0-1. The effect of combinations of interferons on the antigenic profile of human melanoma cells displaying different organ colonization and spontaneous metastatic potential in athymic nude mice was also determined. H0-1 cells were more sensitive to the antiproliferative activity of IFN than to IFN and the combination of interferons resulted in a potentiation of growth suppression. The antiproliferative effect of both interferons was greater in later-passage than in earlier-passage H0-1 cells, possibly reflecting alterations in the evolving tumor cell population as a result of long-term in vitro propagation and/or the selective outgrowth of cells with an increased growth rate. The enhanced growth suppression observed in H0-1 cells treated with the combination of IFN plus IFN was not associated with a significant increase in the level of melanin, a marker of melanoma differentiation, above that observed with either interferon used alone. IFN and IFN differentially modulated the expression of class I and II HLA and melanoma-associated antigens in H0-1 cells and a series of melanoma cells with different organ colonization and metastatic potential, including MeWo, MeM 50-10, MeM 50-17, 3S5 and 70W. No consistent potentiation or antagonism in the expression of any specific antigen was observed in any of the melanoma cell lines exposed to the combination of interferons. The present study demonstrates that the combination of IFN plus IFN can potentiate growth suppression in H0-1 human melanoma cells and that this effect is not associated with an increase in differentiation or a potentiation in antigenic modulation. In addition, no direct correlation between the expression of any specific antigen or its modulation by IFN or IFN, alone or in combination, and organ colonization and metastatic potential in nude mice was observed in the different melanoma cell lines.  相似文献   

3.
-N-Acetyl-d-hexosaminidase from Aspergillus oryzae catalysed the stereo- and regiospecific formation of the 6-O-benzylated disaccharide derivatives GalNAc1-3(6- OBn)Gal-SEt and GlcNAc1-3(6-OBn)Gal-SEt, which were obtained in transglycosylation reactions employing ethyl 6- O-benzyl-1-thio--d-galactopyranoside as acceptor. Preparative amounts of the chitobiose derivative GlcNAc1- 3GlcNAc-OPhNO2-p was prepared as well. - N-Acetyl-d-hexosaminidase from bovine testes catalysed the specific synthesis of GlcNAc1-3(6-OBn)GlcNH2-SEt and GalNAc1-3(6-OBn)GlcNH2-SEt, employing ethyl 2-amino-6-O-benzyl-2-deoxy-1-thio--d-glucopyranoside as acceptor. -d-Glucuronidase from E. coli was found to catalyse the formation of GlcA1-3(6-OBn)GlcNH2- SEt employing the same acceptor.  相似文献   

4.
Summary Antisera were raised in rabbits against dopamine or noradrenaline conjugated to thyroglobulin with glutaraldehyde. These antisera, tested in enzyme linked immunosorbent assay and immunohistochemistry specifically recognized their homologous antigens.With the aid of anti-tyrosine hydroxylase, anti-aromatic aminoacid decarboxylase, anti-dopamine--hydroxylase, anti-dopamine, and anti-noradrenaline antisera, immunohistochemical reactions were performed on glutaraldehyde fixed sections of sheep diencephalon in order to determine the presence of dopamine in the catecholaminergic group A15. Perikarya of this nucleus were stained with anti-tyrosine hydroxylase, anti-aromatic aminoacid decarboxylase and anti-dopamine, but not with anti-dopamine--hydroxylase or anti-noradrenaline. Both of these latter antisera stained fibers within this area. So as recently found in the rat, we could conclude that dopamine is present in group A15 of the sheep.  相似文献   

5.
Luteinizing hormone beta (LH) and follicle stimulating hormone beta (FSH) subunits and their mRNAs were studied in the ram pars tuberalis following different seasonal (winter vs summer) and experimental (intact vs castrated animals) conditions. Hormone-containing cells were identified by immunohistochemistry, and mRNAs for LH and FSH by in situ hybridization using homologous double-stranded 35S-cDNAs. The labelling was quantified by image analysis. Immunohistochemical staining showed that cells containing LH and FSH were localized mainly in the ventral part of the pars tuberalis but that, in the summer, additional LH-containing cells were present in the dorsal part in intact rams. On the other hand, LH-mRNA labelling was found in the whole pars tuberalis in wethers but only in the ventral part in intact rams. The magnitude of LH-mRNA labelling was significantly greater in summer than in winter rams, and in castrated than in intact animals (P<0.001). However, the number of labelled cells was found to be the greatest in the winter (P<0.001) and was not affected by castration. FSH-mRNA expression was similar to that of LH-mRNA except that the level and extent were considerably lower. Thus, our results show an increase in the magnitude of gonadotropin subunit-mRNA in the summer and following castration; this increase appears to involve the entire pars tuberalis.  相似文献   

6.
Summary Malignant transformation of melanocytes may be associated with changes in the expression of HLA antigens and melanoma-associated antigens (MAA). To determine whether these changes reflect the differential expression of HLA antigens and MAA by melanocytes at different stages of differentiation, we have studied the effect of the reversible induction of differentiation by fibroblast interferon (interferon ) and/or 12-O-tetradecanoyl-phorbol 13-acetate (TPA) on the expression of HLA antigens and MAA by the melanoma cell lines DU-2, FO-1 and HO-1. The three melanoma cell lines differed in their sensitivity to the differentiating and antiproliferative activity of these two compounds and displayed an increased growth suppression and induction of differentiation, when incubated with the combination of TPA and interferon . Incubation of the three melanoma cell lines with interferon , TPA or their combination resulted in a differential modulation of the expression of membrane-bound high-molecular-mass melanoma-associated antigen, 115-kDa MAA, 100-kDa MAA, intercellular adhesion molecule 1, HLA class I antigens and gene products of the HLA-D region. Each melanoma cell line displayed a unique pattern of antigenic modulation when exposed to the two differentiating agents alone or in combination. No direct relationship was found between the effects of interferon and/or TPA on the growth and differentiation of the three melanoma cell lines and the expression of HLA antigens or the MAA evaluated in the present study. These findings argue against a direct role of any of the antigens tested in the reversible induction of human melanoma cell differentiation in the in vitro system.  相似文献   

7.
Summary A -1,3-glucan-binding protein (GBP) was purified from crayfish plasma, and incubated with laminarin (L), a -1,3-glucan. The GBP reacted with laminarin (GBP-L) induced strong spreading and partial degranulation of isolated and separated crayfish granular haemocytes. However, neither the GBP nor laminarin alone induced any changes in the crayfish granular cells. When monolayers of granular haemocytes were incubated with 20 g of GBP-L, more than 82% of the haemocytes were affected. The activity of GBP-L on granular cells was dose-dependent and a plateau was reached at 10 g of GBP-L. The degranulation of crayfish haemocytes induced by GBP-L seemed to occur by a regulated exocytosis, since it was strongly inhibited by specific blockers of this process such as SITS or calmidazolium. Monospecific anti-GBP antibodies also totally blocked the effect of GBP-L on crayfish granular cells. Indirect immunofluoresence staining demonstrated that the GBP-L could bind to the surface of granular cells, whereas GBP did not bind or bound very weakly to the haemocyte surface.  相似文献   

8.
Radiolabeled human 2-microglobulin (2m) can bind to mouse histocompatibility (H-2) antigens on the cell surface or to partially purified H-2 antigens in solution. The complexes containing human 2m and H-2 antigens from C3H (H-2k) mice could be immunoprecipitated specifically with alloantisera, rabbit anti-H-2 xenoantisera, and with monoclonal H-2-specific antibodies. Specific association with H-2 antigens was also observed with other haplotypes. The only exception was B10.D2 (H-2 d ) from which complexes containing human 2M could only be precipitated with anti-H-2 xenosera. Thus radiolabeled human 2M can be used as a specific label for mouse H-2 antigens in precipitation and radioimmunoassays. The application of this finding extends to major histocompatibility complex antigens of other species, and to differentiation antigens with primary association with 2m.Abbreviations used in this paper MHC major histocompatibility complex - 2m 2-microglobulin - LcH Lens culinaris hemagglutinin  相似文献   

9.
Summary The oligosaccharide-producing activity of -galactosidase-1, one of the isomers of -galactosidase (-d-galactoside galactohydrolase, EC 3.2.1.23) from Bacillus circulans was changed after immobilization onto porous silica gel (Merckogel) by crosslinkage with glutaraldehyde. The reason for this modification was studied by treating the free enzyme with glutaraldehyde. Glutaraldehyde of 0.025% to 3% modified 40% to 90% of the free amino groups with or without intermolecular crosslinking. The maximum yield of oligosaccharides increased from 12% to 40% depending upon degree of modification, while native enzyme gave only 6% trisaccharides during hydrolysis of 127 mM lactose. The K m value for the enzyme treated with glutaraldehyde was also increased.  相似文献   

10.
Deposition of amyloid peptide in human brain in the form of senile plaques is a neuropathological hallmark of Alzheimers disease (AD). Levels of a phospholipid breakdown product, glycerophosphocholine (GPC), also increase in AD brain. The effect of GPC on amyloid (1–40) peptide (A) aggregation in PBS buffer was investigated by circular dichroism and fluoresence spectroscopy; interactions of A and GPC with the intact erythrocyte membrane was examined by fluoresence spectroscopy. Fluorescamine labeled A studies indicate GPC enhances A aggregation. CD spectroscopy reveals that A in the presence of GPC adopts 14% more -sheet structure than does A alone. Fluorescamine anisotropy measurements show that GPC and A interact in the phospholipid head-group region of the erythrocyte membrane. In summary, both soluble A and GPC insert into the phospholipid head-group region of the membrane where they interact leading to -sheet formation in soluble A which enhances A aggregation.  相似文献   

11.
The aim of this investigation was to study the putative role of protein phosphorylation in interleukin-1 (IL-1) induced signal transduction in insulin producing cells. For this purpose, insulin producing RINm-5F cells were exposed to IL-1 for 7 hours with or without different agonists and antagonists to protein kinases and phosphatases and the production of nitrite was subsequently determined. It has been shown earlier that IL-1 will stimulate the production of nitrite in such cells. It was found that EDTA, TPA and staurosporine did not affect IL-1 induced nitrite production. However, the tyrosine kinase antagonist tyrphostin inhibited, whereas sodium orthovanadate, okadaic acid and cyclosporin A, all inhibitors of protein phosphatases, potentiated IL-1 induced nitrite release to the medium. The tyrosine kinase antagonist genistein potentiated at a low concentration and inhibited at a high concentration the IL-1 effect. It is concluded that protein phosphorylation events, mediated either by protein kinases or phosphatases on both tyrosine and serine/threonine residues, may mediate or antagonize IL-1 induced signal transduction in insulin producing cells.  相似文献   

12.
A loss of sarcolemmal dystrophin was observed by immuno-fluorescence studies in rabbit hearts subjected to in situ myocardial ischemia and by immuno-blotting of the Triton soluble membrane fraction of isolated rabbit cardiomyocytes subjected to in vitro ischemia. This ischemic loss of dystrophin was a specific event in that no ischemic loss of sarcolemmal -sarcoglycan, -sarcoglycan, DG, or DG was observed. The maintenance of sarcolemmal DG (43 Kd) during ischemia was interesting in that dystrophin binds to the C-terminus of DG. However, during late in vitro ischemia, a 30 Kd band was observed that was immuno-reactive for DG. Additionally, this 30 Kd-DG band was observed in rabbit myocardium subjected to autolysis. Finally, the 30 Kd-DG was observed in the purified sarcolemmal fraction of rabbit cardiomyocytes subjected to a prolonged period of in vitro ischemia, confirming the sarcolemmal localization of this band. The potential patho-physiologic significance of this band was indicated by the appearance of this band at 120–180 min of in vitro ischemia, directly correlating with the onset of irreversible injury, as manifested by osmotic fragility. Additionally the appearance of this band was significantly reduced by the endogenous cardioprotective mechanism, in vitro ischemic preconditioning, which delays the onset of osmotic fragility. In addition to dystrophin, DG binds caveolin-3 and Grb-2 at its C-terminus. The presence of Grb-2 and caveolin-3 in the membrane fractions of oxygenated and ischemic cardiomyocytes was determined by Western blotting. An increase in the level of membrane Grb-2 and caveolin-3 was observed following ischemic preconditioning as compared to control cells. The formation of this 30 Kd-DG degradation product is potentially related to the transition from the reversible to the irreversible phase of myocardial ischemic cell injury and a decrease in 30 Kd-DG might mediate the cardioprotection provided by ischemic preconditioning.  相似文献   

13.
Summary The eye lens-crystallins in cow and chicken are encoded by a family of at least six genes. In order to assess the distribution of the corresponding genes among other vertebrates we hybridized -crystallin sequences (A2, A3/A1, A4, B1, B2, B3), isolated from a bovine lens cDNA library, to Southern blots on whichEcoR1-digested chromosomal DNA was blotted from different vertebrate species. These included human, chimpanzee, calf, rat, pigeon, duck, monitor lizard, toad, trout, and lamprey. Positive hybridization signals were found in the representatives of virtually all classes of vertebrates. The basic B-crystallins gave hybridization signals in more species than the acidic A ones. In monitor lizard and toad the weakest hybridization signals for basic crystallin probes were found. For acidic crystallin probes the distribution pattern was more simple; among cold-blooded vertebrates a signal for A2 was found in trout and lamprey, for A4 in trout, and for A3/A1 only in toad. The results demonstrate that the duplications leading to the -crystallin gene family occurred before or during the earliest stages of vertebrate evolution.  相似文献   

14.
Zusammenfassung Pantothensäurebedürftige Hefezellen können ihren Bedarf an diesem Vitamin nicht allein aus -Alanin decken, sondern auch aus Benzoyl--Alanin, -Alanyl-d,l-Norleucin und -Alanyl-l-Histidin. Der Antagonist Asparagin hemmt die Verwertung dieser Peptide genauso wie diejenige der freien Aminosäure. Durch höhere Konzentrationen an -Alanin oder -Alanyl-d,l-Norleucin läßt sich die Hemmwirkung nicht allein kompensieren, es kommt sogar zu einer Förderung des Hefewachstums. Der Antagonist wird dann zum Synergisten.
Summary The -alanine containing peptides benzoyl--alanine, -alanyl-d,l-norleucine and -alanyl-l-histidine can substitute for the amino acid -alanine in a pantothenic acid requiring yeast. Asparagine, an antagonist of -alanine, affects these peptides in a similar manner. In combination with an overdose of -alanine or -alanyl-d,l-norleucine, asparagine is no longer an antagonist but becomes a synergist.
  相似文献   

15.
Using isoenzyme-specific antisera, we have studied the distribution of protein kinase C isoforms in fetal mouse organs at the developmental age of 17 days. Two different sets of antibodies, produced by different manufacturers, were employed in this study. The specificity of the antisera was tested by immunoblotting experiments using whole fetal mouse extracts. Immunohistochemistry was carried out by means of an alkaline phosphatase-conjugated secondary antibody. Analysis of fetal mouse longitudinal cryostat sections stained with the antibodies demonstrated a distinct distribution of protein kinase C isoforms in the tissues. Protein kinase C- and C-I were present in all tissues examined, whereas the C-II isoform was absent in the lung and the liver. Protein kinase C- was identified in brain, spinal ganglia, and adrenal gland. The C- isoenzyme was abundantly expressed in spinal ganglia and in the smooth muscle cells of the bronchial wall. Antisera to C- and C- isoforms heavily stained liver, kidney, and spinal ganglia, whereas the C- isozyme was mainly detected in brain, stomach and kidney. Thus, protein kinase C-, C-I, C-II, C-, C- and C- were the isoforms present in many of the organs investigated. The two sets of antibodies gave slightly different results that might be ascribed to the different epitopes recognized by the antisera. One set of antisera was employed to investigate the distribution of the isoforms in selected organs from an earlier developmental age (15 days) and from adult animals. Both qualitative and quantitative differences were seen in comparison with the same organs from a 17-day fetus.  相似文献   

16.
Summary The ultrastructural immunocytochemical peroxidase-antiperoxidase technique used on serial sections reveals that certain corticotropic cells contain both ACTH and FSH, but not LH (ACTH/FSH cells). To determine the specificity of the anti-FSH staining in these cells, immunocytochemical absorption experiments were performed. The results indicate that (1) anti-FSH and -ACTH antisera are bound to different antigens in the corticotropic cell, and (2) anti-FSH staining is specific for a FSH-like antigen. In the ACTH/FSH cells both hormones are stored in the same secretory granules, distributed among other granules that contain only ACTH.  相似文献   

17.
Summary With growing cells of a Nocardia sp., isolated from soil, the degradation of 5-pregnene-3, 20-diol into 3-[5-oxo-7a-methyl-1 (1-hydroxo)-ethyl-3a-perhydroindane-4]-propionic acid was investigated. The results show that iron is essential for production of the perhydroindanpropionic acid, that this production is greatly enhanced by the presence of calcium and that it is maximal in the pH range 7.0–7.5.Abbreviations used in the text PD 5-pregnene-3, 20-diol (pregnendiol) - PDSA 3-[5-oxo-7a-methyl-1(1-hydroxo)-ethyl-3a-perhydroindane-4]-propionic acid (pregnendiol-secoacid) - PSA 3-[5-oxo-7a-methyl-1-acetyl-3a-perhydroindane-4]-propionic acid (progesterone-secoacid) - EDTA Ethylendiamintetracetic acid - DMSO Dimethylsulfoxide  相似文献   

18.
Serological and immunochemical assays have shown that the monoclonal antibody Q1/28 recognizes an antigenic determinant which is expressed on the heavy chain of subsets of HLA-A, B antigens and is distinct from those defining the serological polymorphism of this system. Association of the HLA-A, B heavy chain with 2-microglobulin is not required for expression of the antigenic determinant recognized by the monoclonal antibody Q1/28, since this antibody can immunoprecipitate a 45 000 m. w. component from radiolabeled lymphoid-cell glycoproteins immunodepleted with either an anti-human 2-microglobulin xenoantiserum or the MoAb W6/32 to framework determinants of HLA-A, B, C antigens. Furthermore, the MoAb Q1/28 can immunoprecipitate a 45 000 m. w. component from an NP40lysate of radiolabeled Daudi cells, which lack the genetic information for 2-microglobulin. The determinant recognized by the MoAb Q1/28 is relatively resistant to denaturing treatments and does not appear to be carbohydrate in nature. The MoAb Q1/28 is the first example of an antibody which recognizes an antigenic determinant expressed on both the 2-microglobulin-associated and free HLA-A, B heavy chains.  相似文献   

19.
Summary In the brain of Rana temporaria, two distinct systems reactive with - and -endorphin antisera, respectively, and with a met-enkephalin antiserum, have been detected immunohistochemically.Neurons reacting with - and -endorphin antisera are located (1) in the preoptic nucleus, and (2) in the pars ventralis of the tuber cinereum. Immunoreactive nerve fibres of both groups of perikarya end in the infundibular floor near the capillaries and the preoptico-hypophysial tract. Control reactions have shown that the immunoreactivity is suppressed by the corresponding antigens, but also by -LPH. In view of these results the immunoreactive systems examined correspond to an /-endorphin system or a lipotropinergic system.Neurons reacting with the met-enkephalin antiserum are located in the paraventricular organ. Intense immunofluorescence was observed in the infundibular floor. Controls show that the labelling by met-enkephalin antiserum is exclusively suppressed by met-enkephalin.In the pituitary gland, on the other hand, - and -endorphin antisera reveal: 1) the MSH/ACTH-like cells of the pars intermedia and 2) the ACTH-like cells of the pars distalis.Supported by the D.G.R.S.T., Contrat no 77.7.0648  相似文献   

20.
Cinnamomin is a plant type II ribosome-inactivating protein (RIP) isolated from the seeds of Cinnamomum camphora. It consists of two nonidentical polypeptide chains (A- and B-chain) held together through one disulfide linkage. Its A- and B-chain contain 0.3% and 3.9% sugars respectively. The B-chain of cinnamomin was digested by pronase E and then the liberated glycopeptides were separated from non-glycopeptides by gel filtration chromatography on a Bio-Gel P-4 column. Three crude glycopeptides were obtained by continuing chromatography over anion-exchange resin (AG1-X2) in the buffer of 2% pyridine-acetic acid (pH 8.3) with a polygradient elution system. Through further purification by the gel filtration chromatography and HPLC, three major glycopeptides, GP1, GP2 and GP3 were obtained. Mainly by two-dimensional Nuclear Magnetic Resonance (NMR) including TOCSY, DQF-COSY, NOESY, HMQC and HMBC, their primary structures were analyzed as: Man1,3Man1,6(Man1,3)(Xyl1,2)Man1,4GlcNAc1,4GlcNAc1-(Gly-)Asn-Asn-Thr(GP1), Man1,6(Man1,3)(Xyl1,2)Man1,4GlcNAc1,4(Fuc1,3)GlcNAc1-Asn-Ala-Thr(GP2),Man1,6(Man1,3)Man1,6(Man1,2 Man1,3)Man1,4GlcNAc1,4GlcNAc1-(Ala-)Asn-Gly-Thr(GP3).  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号