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 46 毫秒
1.
Monoclonal antibodies (mAb) were prepared against conjugated transforming growth factor 1 (TGF1) peptides: amino acid positions 48–60 and positions 86–101. Two antibodies, mAb 16-3G1 [anti-(48–60)] and mAb 5-2G6 [anti-(86–101)] cross-reacted with native TGF1,-2 and-3 (16-3G1) or only with native TGF1 (5-2G6). Both mAb were used to characterize TGF-mediated effects on the metastatic potential in nude mice of human carcinoma cell line SLU-1 and its metastatic subline SLU-M1. Autocrine TGF1-mediated up-regulation of cell proliferation and its suppression by anti-TGF antibodies in vitro was recorded for SLU-M1 cells whereas SLU-1 cell proliferation in vitro appeared to be refractory to anti-TGF antibodies and exogenous TGF-1. However, the potential of s.c. tumours to develop distant metastases in nude mice was about the same for both cell lines. Development of primary tumours and distant metastases could be suppressed by treatment of mice with anti-TGF antibodies. Thus we assume that the metastatic potential of tumour cells is independent of TGF-mediated growth-regulation effects in vitro. The anti-TGF-induced suppression of tumour progression and metastasis in nude mice might rather result from stimulation of the immune surveillance. TGF-mediated autocrine down-regulation of MHC-unrestricted cytotoxicity of activated human monocytes and CD56+ LAK cells and its reversion by anti-TGF antibodies could be readily demonstrated. In all our experimental series, the neutralizing potential of both anti-TGF antibodies, though directed against opposite sites of the TGF1 molecule, was very similar.  相似文献   

2.
The roles of transforming growth factor-beta (TGF) in heart or skeletal muscle development and physiology are still the subject of controversies. Our aim was to block, in transgenic mice, the TGF signalling pathway by a dominant negative mutant of the TGF type II receptor fused to the enhanced green fluorescent protein (TRII-KR-EGFP) under the control of a 7.1 kbp mouse beta-myosin heavy chain (MHC) promoter to investigate the roles of TGF in the heart and slow skeletal muscles. First, we generated two transgenic lines overexpressing EGFP under the control of the 7.1 kbp MHC promoter. In embryos, EGFP was detectable as early as 7.5 days post coitum. In embryos, newborns and adults, EGFP was expressed mainly in the cardiac ventricles and in slow skeletal muscles. EGFP expression was intense in the bladder but weak in the intestines. In contrast to the endogenous MHC promoter, the activity of the 7.1 kbp MHC promoter in the transgene was not repressed after birth and remained high in adult transgenic mice. We obtained two founders with the transgene comprising the TRII-KR-EGFP sequence under the control of the 7.1 kbp MHC promoter. These founders were generated at a very low frequency and expressed barely detectable levels of TRII-KR-EGFP mRNA. Our failure to obtain transgenic lines overexpressing the dominant negative receptor suggests that the blocking of the TGF signalling pathway in the heart and slow skeletal muscles could be embryonically lethal. To conclude, the 7.1 kbp MHC promoter directs high levels of transgene expression in the cardiac ventricles and in slow skeletal muscles of the mouse. Analysis of the consequences of the blocking of the TGF signalling pathway in the heart will require the use of tissue specific means of conditional gene invalidation.  相似文献   

3.
The effect of transforming growth factor beta-1 (TGF1) expression on fatty acid binding proteins was examined in control and two strains of gene targeted TGF1-deficient mice. Homozygous TGF1-deficient 129 × CF-1, expressing multifocal inflammatory syndrome, had 25% less liver fatty acid binding protein (L-FABP) when compared to control mice. The decrease in L-FABP expression was not due to multifocal inflammatory syndrome since homozygous TGF1-deficient/immunodeficient C3H mice on a SLID background had 36% lower liver L-FABP than controls. This effect was developmentally related and specific to liver, but not the proximal intestine, where L-FABP is also expressed. Finally, the proximal intestine also expresses intestinal-FABP (1-FABP) which decreased 3-fold in the TGF1-deficient/immunodeficient C3H mice only. Thus, TGF1 appears to regulate the expression of L-FABP and I-FABP in the liver and the proximal intestine, respectively.Abbreviations L-FABP liver fatty acid binding protein - I-FABP intestinal fatty acid binding protein - TGF1 transforming growth factor beta-1 - TNF- tumor necrosis factor- - MIP- macrophage inflammatory protein- - PMSF phenylmethyl sulfonyl fluoride - PBS phosphate buffered saline  相似文献   

4.
Barrier-raised transforming growth factor 1 (TGF1)-deficient mice consistently die before 35 days of age of a severe multiorgan inflammatory disease that can affect the skeletal muscle, heart, liver, pancreas, salivary gland, lung, oesophagus and stomach. The underlying cause of this disease is not known. To determine whether abnormal responsiveness of the immune system to the presence of enteric flora plays a causative role, a colony of TGF1-deficient and wild-type mice were raised in a sterile environment. Seven germ-free TGF1-deficient and 5 germ-free TGF1 wild-type mice were examined. Lesion development was analysed and compared with historical data on 50 barrier-raised TGF1 mutant mice and 32 barrier-raised wild-type mice. All germ-free TGF1-deficient mice died shortly after weaning, as do their barrier-raised counterparts. There was a significant delay in death in germ-free TGF1-deficient mice compared with barrier-raised mutant mice. However, there was no difference in the type, severity or incidence of lesions between TGF1 mutant mice raised under germ-free or barrier conditions. Germ- free wild-type mice had no lesions. It is concluded that microorganisms play a minimal role in disease induction in TGF1-deficient mice  相似文献   

5.
《Glycoconjugate journal》1995,12(5):721-728
The expression of neutral glycosphingolipids (GSLs) and gangliosides was investigated in cryosections of normal mouse skeletal muscle and in muscle of mice with neuromuscular diseases using indirect immunofluorescence microscopy. Transversal and longitudinal sections were immunostained with specific polyclonal antibodies against lactosylceramide, lacto-N-neotetraosylceramide, globoside, GM3(Neu5Ac), GM3(Neu5Gc) and GM1(Neu5Ac) as well as monoclonal anti-Forssman GSL antibody. In normal CBA/J mouse muscle (control) the main immunohistochemically detected ganglioside was GM3(Neu5Ac) followed by moderately expressed GM3(Neu5Gc) and GM1. The neutral GSLs lactosylceramide and globoside were stained with almost identical, high fluorescence intensity. Low amounts of lacto-N-neotetraosylceramide and trace quantities of Forssman GSL were immunostained. All GSLs were detected in the sarcolemma, but also in considerable amounts at the intracellular level. Mice with neuromuscular diseases were the A2G-adr mouse mutant (a model for human recessive myotonia of Becker type), the BL6-wr mutant (a model for motor neuron disease) and the BL10-mdx mouse mutant (a model for human Duchenne muscular dystrophy). No changes in GSL expression were found in the A2G-adr mouse, while muscle of the BL6-wr mouse showed increased intensity of immunofluorescence in stainings with anti-lactosylceramide and anti-GM3(Neu5Ac) antibodies. Muscle of BL10-mdx mice showed the most prominent changes in GSL expression with reduced fluorescence intensity for all antibodies. Major differences were not observed in the intensities of GSLs, but there were significant differences in the patterns of distribution on plasma membrane and at the subcellular level. The exact nature and pathogenesis of these changes should be elucidated since such investigations could furnish advances in understanding the functional role of neutral GSLs and gangliosides in normal as well as in diseased muscle. Abbreviations: BSA, bovine serum albumin; DAPI, 4, 6-diamidine-2-phenylindole-dihydrochloride; DTAF, dichlorotriazinylamino-fluorescein; GSL(s), glycosphingolipid(s); Neu5Ac,N-acetylneuraminic acid; Neu5Gc,N-glycolylneuraminic acid [53]; PBS, phosphate buffered saline. The designation of the following glycosphingolipids follows the IUPAC-IUB recommendations [54] and the nomenclature of Svennerholm [55]. Lactosylceramide or LacCer, Gal1-4Glc1-1Cer; gangliotriaosylceramide or GgOse3Cer, GalNAc1-4Gal1-4Glc1-1Cer; globotriaosylceramide or GbOse3Cer, Gal1-4Gal1-4Glc1-1Cer; gangliotetraosylceramide or GgOse3Cer, Gal1-3GalNAc1-4Gal1-4Glc1-1Cer; globotetraosylceramide or GbOse4Cer, GalNAc1-3Gal1-4Gal1-4Glc1-1Cer; lacto-N-neotetraosylceramide or nLcOse4Cer, Gal1-4GlcNAc1-3Gal1-4Glc1-1Cer; Forssman GSL or GbOse5Cer, GalNAc1-3GalNAc1-3GAl1-4Gal1-4Glc1-1Cer; GM3, II3Neu5Ac-LacCer; GM1, II3Neu5Ac-GgOse4Cer.  相似文献   

6.
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   

7.
Ehrlich ascites tumor cells incorporate [methyl-3H]thymidine into DNA independently of exogenous growth factors or fetal calf serum. Using an acid/ethanol extraction procedure we have obtained from these tumor cells a fraction that induces both the proliferation and the formation of cell foci by Swiss 3T3 mouse fibroblasts in the presence of insulin; inhibits the proliferation of Mv1Lu mink lung epithelial cells; and stimulates the growth of NRK rat kidney fibroblasts in soft-agar in the presence of epidermal growth factor. An antibody against transforming growth factor- (TGF) prevents both the tumor extract-induced proliferation of Swiss 3T3 fibroblasts and the tumor extract-induced proliferative arrest of Mv1Lu cells. The tumor cells secrete a TGF-like activity to the extracellular medium in a partially-activated form. However, authentic TGF does not affect their proliferation, and no TGF receptors were detected using [125I]TGF as a ligand. Therefore, the absence of TGF receptors with ligand-binding capacity in these tumor cells may bypass the negative control that this factor exerts on the proliferation of their normal cell counterparts.  相似文献   

8.
Zusammenfassung Es wird ein simultanes Azokupplungsverfahren zur intrazellulären Darstellung der sauren (Hetero-) und neutralen -Galactosidase (Lactase) in verschiedenen Organen von Ratte, Maus und Meerschweinchen beschrieben.Das Inkubationsmedium enthält 4,5–9mg 1-Naphthyl--galactopyranosid (gelöst in 0,4ml NN-Dimethylformamid) und 0,5–0,8ml 2% Hexazonium-p-rosanilin in 9 ml 0,1 M Citrat-Puffer, pH 5 (Hetero--galactosidase) oder 5,5 (Lactase).Unter allen Organen reagiert die saure -Galactosidase am kräftigsten in den Lysosomen von Nebenhoden, Niere, Nebenniere, Schilddrüse, Glandula präputialis und inguinalis, Milz, Colon und Plexus chorioideus; die neutrale -Galactosidase kommt in mittlerer Aktivität nur im intestinalen Stäbchensaum vor.Die intralysosomale Darstellung der löslichen Hetero--galactosidase erfordert Blockfixation in Glutaraldehyd; die Lactase kann an frischen oder gefriergetrockneten Schnitten untersucht werden. Im proximalen Tubulus der Rattenniere wird die saure -Galactosidase durch Formol unabhängig von der Konzentration des Fixans verglichen mit Glutaraldehyd stärker gehemmt. Spätestens 10 min nach Beginn der Fixation hat das Enzym seine Basisaktivität erreicht. Spülen in hypertoner Zuckerlösung macht die Inhibition der Hetero--galactosidase teilweise rückgängig.Die mit dem Azokupplungs- und Indigogen-Verfahren gewonnenen Befunde sind weitgehend identisch.
On the histochemical and microchemical demonstration of -galactosidase by means of 1-naphthyl--galactopyranoside
Summary A simultaneous azo coupling method for the intracellular demonstration of acid (hetero-) and neutral -galactosidase (lactase) in various organs of rats, mice and guinea-pigs is described.The recommended incubation medium consists of 4.5–9 mg 1-naphthyl--galactopyranoside (dissolved in 0.4 ml NN-dimethylformamide) and 0.5–0.8 ml 2% hexazonium-p-rosaniline in 9 ml 0.1 M citrate buffer, pH 5.0 (hetero--galactosidase) or 5.5 (lactase).Among all organs investigated the strongest acid -galactosidase reaction regularly occurs in the lysosomes of the epididymis, kidney, adrenal, thyroid, preputial and inguinal gland, spleen, colon and chorioid plexus; the neutral -galactosidase can only be detected in the intestinal brush border exhibiting a moderate activity.Because hetero--galactosidase is a highly soluble enzyme bloc-fixation using glutaraldehyde becomes necessary to achieve a precise intralysosomal localization; for the demonstration of lactase fresh or freeze-dried cryostat sections are suitable. —In the proximal tubule of the rat kidney independent of their concentration the inhibition of acid -galactosidase following treatment with formol surpasses that of glutaraldehyde. Within the first ten minutes of fixation the enzyme reaches its basis activity. The recovery rate of renal hetero--galactosidase considerably increases in the course of washing in hypertonic sugar solution.In comparison with the indigogenic technique nearly identical results can be obtained with the azo coupling procedure.
  相似文献   

9.
The conformational properties of the oligosaccharide chain of GM1 ganglioside containingN-glycolyl-neuraminic acid, -Gal-(1-3)--GalNAc-(1-4)-[-Neu5Gc-(2-3)]--Gal-(1-4)--Glc-(1-1)-Cer, were studied through NMR nuclear Overhauser effect investigations on the monomeric ganglioside in dimethylsulfoxide, and on mixed micelles of ganglioside and dodecylphosphocholine in water. Several interresidual contacts for the trisaccharide core--GalNAc-(1-4)-[-Neu5Gc-(2-3)]--Gal-were found to fix the relative orientitation of the three saccharides, while the glycosidic linkage of the terminal -Gal-was found to be quite mobile as the -Gal-(1-3)--GalNAc-disaccharide exists in different conformations. These results are similar to those found for two GM1 gangliosides containingN-acetyl-neuraminic acid and neuraminic acid [1].Abbreviations Ganglioside nomenclature is in accordance with Svennerholm [23] and the IUPAC-IUB Recommendations [24] GM3(Neu5Ac) II3Neu5AcLacCer, -Neu5Ac-(2-3)--Gal-(1-4)--Glc-(1-1)-Cer - GM3(Neu5Gc) II3Neu5GcLacCer, -Neu5Gc-(2-3)--Gal-(1-4)--Glc-(1-1)-Cer - GM1(Neu5Ac) II3Neu5AcGgOse4Cer, -Gal-(1-3)--GalNAc-(1-4)-[-Neu5Ac-(2-3)]--Gal-(1-4)--Glc-(1-1)-Cer - GM1(Neu5Gc) II3Neu5GcGgOse4Cer, -Gal-(1-3)--GalNAc-(1-4)-[-Neu5Gc-(2-3)]--Gal-(1-4)--Glc-(1-1)-Cer - GM1(Neu) II3NeuGgOse4Cer, -Gal-(1-3)--GalNAc-(1-4)-[-Neu-(2-3)]--Glc-(1-1)-Cer - GD1a IV3Neu5AcII3Neu5AcGgOse4Cer, -Neu5Ac-(2-3)--Gal-(1-3)--GalNAc-(1-4)-[-Neu5Ac-(2-3)]--Gal-(1-4)--Glc-(1-1)-Cer - GalNAc-GD1a IV4GalNAcIV3Neu5AcII3Neu5AcGgOse4Cer, -GalNAc-(1-4)-[-Neu5Ac-(2-3)]--Gal-(1-3)--GalNAc-(1-4)-[-Neu5Ac-(2-3)]--Gal-(1-4)--Glc-(1-1)-Cer - Neu neuraminic acid - Neu5Ac N-acetyl-neuraminic acid - Neu5Gc N-glycolyl-neuraminic acid - Cer ceramide  相似文献   

10.
Six tetrasaccharide fractions were isolated from shark cartilage chondroitin sulfate D by gel filtration chromatography followed by HPLC on an amine-bound silica column after exhaustive digestion with testicular hyaluronidase. Their structures were determined unambiguously by one- and two-dimensional 500 MHz1H NMR spectroscopy in conjunction with HPLC analysis of chondroitinase AC-II digests of the tetrasaccharides. One fraction was found to contain two tetrasaccharide components. All the seven tetrasaccharides shared the common core structure GlcA1-3GalNAc1-4GlcA1-3GalNAc with various sulfation profiles. Four were disulfated comprising of two monosulfated disaccharide units GlcA1-3GalNAc(4-sulfate) and/or GlcA1-3GalNAc(6-sulfate), whereas the other three were hitherto unreported trisulfated tetrasaccharides containing a disulfated disaccharide unit GlcA(2-sulfate)1-3GalNAc(6-sulfate) and a monosulfated disaccharide unit GlcA1-3GalNAc(4-or 6-sulfate). These sulfated tetrasaccharides were demonstrated to serve as appropriate acceptor substrates for serum -N-acetylgalactosaminyltransferase, indicating their usefulness as authentic oligosaccharide substrates or probes for the glycobiology of sulfated glycosaminoglycans.Abbreviations NFU National formulary unit - COSY correlation spectroscopy - HOHAHA homonuclear Hartmann-Hahn - 1D or 2D one- or two-dimensional - IdoA l-iduronic acid - GlcA d-gluco-4-enepyranosyluronic acid - Di-0S GlcA1-3GalNAc - Di-4S GlcA1-3GalNAc(4-sulfate) - Di-4S GlcA1-3GalNAc(4-sulfate) - Di-6S GlcA1-3GalNAc(6-sulfate) - Di-6S GlcA1-3GalNAc(6-sulfate) - Di-diS d GlcA(2-sulfate)1-3GalNAc(6-sulfate) - Di-diSE GlcA1-3GalNAc(4, 6-disulfate) - U G, U, 2S, 4S, and 6S represent GlcA, GalNAc, GlcA, 2-O-sulfate, 4-O-sulfate, and 6-O-sulfate, respectively  相似文献   

11.
The genes were cloned for the two apoprotein subunits, and ,of phycocyanin from the cyanobacterium Spirulina maxima = Arthrospiramaxima) strain F3. The - and -subunit gene-coding regionscontain 489 bp and 519 bp, respectively. The -subunit gene is upstreamfrom the -subunit gene, with a 111-bp segment separating them.Similarities between the -subunits of S. maxima and nine othercyanobacteria were between 58% and 99%, as were those between the -subunits. The maximum similarity between the - and -subunits from S. maxima was 27%.  相似文献   

12.
Unlike classical -1,4-galactosyltransferase (-1,4-GalT I), -1,4-GalT V (formerly IV*) has little activity towards 1 mM N-acetylglucosamine [Sato et al. (1998) Proc Natl Acad Sci USA 95: 472-477]. The human -1,4-GalTs I and V were expressed individually in Sf-9 cells by transfection of the full coding sequences, and their N-acetyllactosamine synthetase activities were determined towards different N-acetylglucosamine concentrations. Kinetic studies using the cell homogenates as an enzyme source revealed that -1,4-GalTs I and V possess Km values of 0.6 mM and 33 mM towards N-acetylglucosamine, and of 48 µM and 41 µM towards UDPGal, respectively. No significant inhibition of N-acetyllactosamine synthesis with -lactalbumin was observed for -1,4-GalT V but the significant inhibition with -lactalbumin was observed for -1,4-GalT I.  相似文献   

13.
We have carried out a comparative functional analysis of the rat TGF-1 and Xenopus laevis TGF-5 promoters across several mammalian and amphibian cell lines. Progressive deletion constructs of both the promoters have been made using a PCR based approach and the basal promoter activities studied in Xenopus tadpole cell line (XTC), Xenopus adult kidney fibroblast cell line (A6), human hepatoma cell line (HepG2), normal rat kidney cell line (NRK), and Chinese hamster ovary cell line (CHO). Data suggests that the basal promoter activity of TGF-1 is low as compared to TGF-5 promoter in XTC cells but comparable in A6 cells, while TGF-5 promoter shows nearly negligible activity as compared to TGF-5 promoter in all the tested mammalian cell lines. Moreover, TGF-5 promoter is found to be repressed in XTC cells on treatment with TGF-5 protein. Thus, the regulation of TGF-1 and TGF-5 promoters is distinct in amphibian and mammalian species. We therefore suggest that contrary to the suggested functional equivalence of TGF-1 and TGF-5 proteins, TGF-1 and TGF-5 genes have distinct functions in their respective species. Present address (Kartiki V. Desai): Laboratory of Cell Regulation and Carcinogenesis, NCI, NIH Bldg 41, Room C619, Bethesda, MD 20892, USA  相似文献   

14.
This study reports a novel splice variant form of the voltage-dependent calcium channel 2 subunit (2g). This variant is composed of the conserved amino-terminal sequences of the 2a subunit, but lacks the -subunit interaction domain (BID), which is thought essential for interactions with the 1 subunit. Gene structure analysis revealed that this gene was composed of 13 translated exons spread over 107 kb of the genome. The gene structure of the 2 subunit was similar in exon-intron organization to the murine 3 and human 4 subunits. Electrophysiological evaluation revealed that 2a and 2g affected channel properties in different ways. The 2a subunit increased the peak amplitude, but failed to increase channel inactivation, while 2g had no significant effects on either the peak current amplitude or channel inactivation. Other subunits, such as 3 and 4, significantly increased the peak current and accelerated current inactivation.  相似文献   

15.
Imidazole fungicides such as imazalil, prochloraz, and triflurnizole and the triazole growth retardant paclobutrazol promote the shoot-inducing effect of exogenous cytokinins in Araceae, such as Spathiphyllum floribundum Schott and Anthurium andreanum Schott. The mechanism of their action could partially be based on the inhibition of gibberellic acid (GA) biosynthesis, because administration of GA3 inhibits the phenomenon completely in S. floribundum. Not only is the suppression of GA biosynthesis involved, but also the metabolism of endogenous cytokinins is significantly altered. Although the balance between isopentenyladenine, zeatin, dihydrozeatin, and their derivatives was shifted to distinguished directions by administration of BA and/or imazalil and/or GA3, no correlation between these changes in metabolic pathways and the number of shoots could be found. The metabolism of BA was not significantly altered by adding imazalil to the micropropagation medium of S. floribundum.Abbreviations 2,4-D 2,4-dichlorophenoxyacetic acid - [9R-5P]DHZ 9--d-ribofuranosyl-dihydrozeatin-monophosphate - [9R-5P]iP 6-isopentenyl-9--d-ribofuranosyladenine-monophosphate - [9R-5P]Z 9--d-ribofuranosyl-zeatin-monophosphate - [9G]BA 6-benzyl-9--d-glucopyranosyladenine - [9G]DHZ 9--d-glucopyranosyl-dihydrozeatin - [9G]iP 6-isopentenyl-9--d-glucopyranosyladenine - [9G]Z 9--d-glucopyranosyl-zeatin - [9R]BA 6-benzyl-9--d-ribofuranosyladenine - [9R]DHZ 9--d-ribofuranosyl-dihydrozeatin - [9R]iP 6-isopentenyl-9--d-ribofuranosyladenine - [9R]Z 9--d-ribofuranosyl-zeatin - BA 6-benzyladenine - DHZ dihydrozeatin - ES+ LC-MS/MS HPLC coupled Electrospray Tandem Mass Spectrometry - f.m. fresh mass - mT 6-(3-hydroxybenzyl)adenine - IMA imazalil - iP isopentenyladenine - NAA 1-naphthalene acetic acid - NFT Nutrient Film Technique - (OG)[9R]DHZ O--glucopyranosyl-9--d-ribofuranosyl-dihydrozeatin - (OG)[9R]Z O--d-glucopyranosyl-9--d-ribofuranosyl-zeatin - (OG)DHZ O--d-glucopyranosyl-dihydrozeatin - (OG)Z O--d-glucopyranosyl-zeatin - PAR Photosynthetic Active Radiation - PBZ paclobutrazol - PRO prochloraz - TDZ thidiazuron - TRI triflurnizole - Z zeatin  相似文献   

16.
Summary The effect of long-term treatment (52 weeks) with high doses of 17-estradiol (1.28 mg/kg/week intramuscularly) on gonadotrophs was studied in the pituitary gland of the beagle bitch. For immunochemical staining the immunoperoxidase technique and antisera to the specific beta () subunits of FSH and LH were employed. For control purposes antisera to the following hormones were also used: bovine TSH, canine GH, canine PRL and porcine ACTH1. In the pars distalis and pars tuberalis of control bitches, in addition to the cells which react solely with antisera to either LH or FSH, most cells were reactive to both antisera. The cells stained for FSH were less numerous than those shown to contain LH. TSH, PRL, GH and ACTH/MSH were localized in distinctly different cell types in the pars distalis of all control animals. In the treated bitches, almost complete regression of cells classically identified as gonadotrophs and stained for LH was observed. On the other hand, using the antiserum to FSH, selective immunochemical staining was localized in cells fitting the morphological characteristics of TSH cells. All these cells were also stained for TSH. However, a few cells were also shown to react solely with the antiserum to TSH. These cells, which seem to contain both TSH and FSH, were further clearly differentiated from PRL, GH and ACTH/MSH cells on the basis of their cytological features, intraglandular distribution and by immunochemical double staining. These observations support the concept that the one cell-one hormone theory may not necessarily apply to the glycoprotein hormones of the dog pituitary gland.Abbreviations of Hormones cited in this Paper ACTH Adrenocorticotropin - FSH Follicle Stimulating Hormone - GH Growth Hormone - LH Luteinizing Hormone - MSH Melanocyte Stimulating Hormone - PRL Prolactin - TSH Thyrotropin The authors are grateful to Mrs. K. Oertel for carrying out the experimental work on animals, to Mrs. B. Schilk and Miss U. Tüshaus for their excellent technical assistance, and to Dr. P. Günzel for his advice and encouragement  相似文献   

17.
Transmannosylation from mannotriose (Man1-4Man1-4Man) to the 4-position at the nonreducing end N-acetylglucosaminyl residue ofN,N-diacetylchitobiose was regioselectively induced through the use of -d-mannanase fromAspergillus niger. The enzyme formed the trisaccharide Man1-4GlcNAc1-4GlcNAc (3.7% of the enzyme-catalysed net decrease ofN,N-diacetylchitobiose) from mannotriose as a donor andN,N-diacetylchitobiose as an acceptor. Mannobiose (Man1-4Man) was also shown to be useful as a donor substrate for the desired trisaccharide synthesis.Abbreviations Man d-mannose - (M n) (n=1–5) -linkedn-mer of mannose - GlcNAc2 2-acetamido-2-deoxy--d-glucopyranosyl-(1–4)-2-acetamido-2-deoxy-d-glucose  相似文献   

18.
The primary structure of adult marmoset hemoglobin has been determined. The - and -chains of HbA were separated on a CM23 column in 8 M urea using a sodium phosphate gradient. Tryptic digests of the - and -chains were fractionated on a Dowex 50W-X2 column using a pH and pyridine acetate gradient. Large peptide fragments were obtained by the cyanogen bromide cleavage of the - and -chains, as well as by tryptic digestion of the maleylated - and -chains. The sequence was derived from the amino acid compositions and sequences of the individual tryptic peptide, automated sequence determination of intact - and -chains, as well as automated sequence determination of cyanogen bromide fragments and tryptic maleylated peptides derived from the - and -chains. The complete structure of marmoset adult hemoglobin is closely homologous to that of other primate hemoglobins. The sequence of the marmoset -chain differs from the -chain of human HbA at positions 8, 19, 23, 68, and 116. The -chain from marmoset HbA differs from the -chain of human HbA at positions 5, 13, 21, 50, 87, and 125.This work was supported in part by funds from a Physicians' Medical Education and Research Foundation Grant of the University of Tennessee Memorial Research Hospital and by NIH General Research Support Grant FR-5541 to the institution.  相似文献   

19.
Chong  D.K.X.  Roberts  W.  Arakawa  T.  Illes  K.  Bagi  G.  Slattery  C.W.  Langridge  W.H.R. 《Transgenic research》1997,6(4):289-296
A 1177 bp cDNA fragment encoding the human milk protein -casein was introduced into Solanum tuberosum cells under control of the auxin-inducible, bidirectional mannopine synthase mas12) promoters using Agrobacterium tumefaciens-mediated leaf disc transformation methods. Antibiotic-resistant plants were regenerated and transformants selected based on luciferase activity carried by the expression vector containing the human -casein cDNA. The presence of human -casein cDNA in the plant genome was detected by PCR and DNA hybridization experiments. Human -casein mRNA was identified in leaf tissues of transgenic plants by RT-PCR analysis. Human - casein was identified in auxin-induced leaf and tuber tissues of transformed potato plants by immunoprecipitation and immunoblot analysis. Human -casein produced in transgenic plants migrated in polyacrylamide gels as a single band with an approximate molecular mass of 30 kDa. Immunoblot experiments identified approximately 0.01% of the total soluble protein of transgenic potato leaf tissue as -casein. The above experiments demonstrate the expression of human milk - casein as part of an edible food plant. These findings open the way for reconstitution of human milk inedible plants for replacement of bovine milk in baby foods for general improvement of infant nutrition, and for prevention of gastric and intestinal diseases in children  相似文献   

20.
A -carotene oxygenase is described which occurs in the Cyanobacterium Microcystis. It cleaves -carotene and zeaxanthin specifically at the positions 7,8 and 7,8, while echinenone and myxoxanthophyll are not affected. The oxidative cleavage of -carotene leads to the formation of -cyclocitral and crocetindial and that of zeaxanthin to hydroxy--cyclocitral and crocetindial in nearly stoichiometric amounts. Oxidant is dioxygen as has been demonstrated by high incroporation (86%) of 18O2 into -cyclocitral. -Carotene oxygenase is membrane bound, sensitive to sulfhydryl reagents, antioxidants and chelating agents. Iron seems to be an essential part of the enzyme activity. Cofactors necessary for the reaction could not be detected.Abbreviations TLC thin layer-chromatography - PIPES piperazine-N,N-bis-(2-ethanesulfonate) Na - TES 2{[tris-(hydroxymethyl)-methyl]-amino} ethanesulfonic acid Dedicated to Professor G. Drews on occasion of his 60th birthday  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