Phosphorylation of an envelope-associated Hsp70 homolog in amyloplasts isolated from cultured cells of sycamore (Acer pseudoplatanus L.)

The presence of Hsp70 and Hsp60 molecular chaperones in amyloplasts isolated from cultured sycamore cells was analyzed by immunoblotting. Hsp70 homologs were located in both amyloplast envelope and stromal fractions, but no Hsp60 homologs were detected in any of the different suborganellar fractions. Incubation of whole amyloplasts or their envelope fraction with Mg2+ gamma-32P-ATP resulted in a rapid phosphorylation of the envelope-associated Hsp70 homolog, which constitutes a major target of phosphorylation in these plastids.     

Chemoenzymatic synthesis of the branched oligosaccharides which correspond to the core structures of N-linked sugar chains

Synthetic routes are described to a partial structure common to all high mannose-type sugar chains and complex-type sugar chains based on a chemoenzymatic strategy which incorporates, (a) enzymatic synthesis of oligosaccharide blocks using glycosidases, and (b) chemical synthesis of the branching oligosaccharides via regioselective coupling. All reaction products correspond to key intermediates necessary for the construction of N-linked oligosaccharides and we have synthesized the branched tetra-manno-oligosaccharide high mannose-type sugar chain and the branched hexa-oligosaccharide complex-type sugar chain using this simple and direct method.     

Biochemical maturation of Spam1 (PH-20) during epididymal transit of mouse sperm involves modifications of N-linked oligosaccharides

Indirect immunofluorescence of mouse caput and caudal sperm shows distinctly different distributions of Spaml protein, which is associated with structural and functional differences of the molecule. Spam1 is uniformly distributed over the surface of the head of caput sperm while in caudal sperm, light and confocal microscopy demonstrate that it is localized to the anterior and posterior regions. The hyaluronidase activity of Spaml in acrosome-intact caput sperm was significantly lower (4.3-fold; P < 0.0001) than that of caudal sperm. The increase in enzymatic activity in caudal sperm is accompanied by a reduction in the molecular weight (MW): in extracts from caput sperm there was a major band at approximately 74 kDa and a minor band at approximately 67 kDa; while for the cauda there was a major band at approximately 67 kDa and minor bands at approximately 70 and -56 kDa. Additionally, the bands from caput sperm were 4.9 to 7.7-fold less intense than those from caudal sperm. This decreased affinity for the polyclonal anti-Spaml suggests the presence of different surface characteristics of the molecule from the two epididymal regions. Computer analysis of the protein structure from Spam1 cDNA sequence reveals four putative N-linked glycosylation sites, and enzymatic deglycosylation suggests that all sites are functional. After endoglycosidase activity of extracts from caput and caudal sperm, both show a major band with a MW of approximately 56 kDa, the size of the membrane-anchored polypeptide backbone. Based on the difference in size and intensity of the Spaml bands and hyaluronidase activities from caput and caudal sperm, the data suggest that the activation of Spaml during epididymal maturation is regulated by deglycosylation.     

Conserved N-linked oligosaccharides of the C-terminal portion of human immunodeficiency virus type 1 gp120 and viral susceptibility to neutralizing antibodies

We have constructed a mutated infectious HIV variant lacking the signals for addition of three N-linked glycans situated in the V4, C4 and V5 regions of HIV gp120. When comparing mutated virus with wildtype virus we found essentially no differences in the phenotypic characteristics of the two viruses except for the expected electrophoretic mobility shift of radioimmuno-precipitated mutated gp120, resulting from the missing N-glycans. Thus, the infectivity titer and the capacity to induce syncytia were similar for the two viruses. The sensitivity of mutant and wildtype virus to a number of neutralizing agents was determined. As expected, the mutant virus was significantly less sensitive to neutralization by Con A, with affinity for the N-glycans eliminated. We found, however, that antibodies to the V3 loop and sCD4 neutralized wild-type virus as efficiently as mutant virus, whereas 2G12, a monoclonal antibody, binding to a discontinuous neutralization epitope, and GP13, binding to the CD4-binding domain, neutralized wildtype virus better than mutant virus. Altogether the data suggest that the three conserved N-linked glycans, despite their location in immediate association with the CD4-binding domain, which is an important neutralization epitope, are not essential for virus replication in cell culture and they are not engaged in shielding neutralization epitopes of gp120 from neutralizing antibodies. However, the glycans evidently influence the three-dimensional conformation of gp120, since their presence increases the availability of the neutralization epitope of 2G12.     

豹斑毒鹅膏菌毒素粗品对黄粉虫的毒性研究

[目的]探讨豹斑毒鹅膏菌毒素粗品对黄粉虫的毒性.[方法]测定了5种大型真菌子实体及毒素粗品对黄粉虫的毒杀活性,并对筛选出的豹斑毒鹅膏菌进行了致死效应研究.[结果]随着豹斑毒鹅膏菌毒素粗品浓度的增大,防治效果越来越明显.当豹斑毒鹅膏菌毒素粗品浓度为17.5 mg/ml时,黄粉虫死亡率为93.3%,效果显著.[结论]豹斑毒鹅膏菌毒素粗品对黄粉虫有较显著的毒杀作用.     

Enzymatic synthesis of N-linked oligosaccharides terminating in multiple sialyl-Lewis(x) and GalNAc-Lewis(x) determinants: clustered glycosides for studying selectin interactions

Galactosyltransferase, sialyltransferase, and fucosyltransferase were used to create a panel of complex oligosaccharides that possess multiple terminal sialyl-Le(x) (NeuAc alpha 2-3Gal[Fuc alpha 1-3] beta 1-4GlcNAc) and GalNAc-Le(x) (GalNAc[Fuc alpha 1-3]beta 1-4GlcNAc). The enzymatic synthesis of tyrosinamide biantennary, triantennary, and tetraantennary N-linked oligosaccharides bearing multiple terminal sialyl-Le(x) was accomplished on the 0.5 mumol scale and the purified products were characterized by electrospray MS and 1H NMR. Likewise, biantennary and triantennary tyrosinamide oligosaccharides bearing multiple terminal GalNAc-Le(x) determinants were synthesized and similarly characterized. The transfer kinetics of human milk alpha 3/4-fucosyltransferase were compared for biantennary oligosaccharide acceptor substrates possessing Gal beta 1-4GlcNAc, GalNAc beta 1-4GlcNAc, and NeuAc alpha 2-3Gal beta 1-4GlcNAc which established NeuAc alpha 2-3Gal beta 1-4GlcNAc as the most efficient acceptor substrate. The resulting complex oligosaccharides were chemically tethered through the tyrosinamide aglycone to the surface of liposomes containing phosphatidylthioethanol, resulting in the generation of glycoliposomes probe which will be useful to study relationships between binding affinity and the micro- and macro-clustering of selectin ligand.     

Ultrastructural modifications of renal cells in the three-spined stickleback (Gasterosteus aculeatus L.) after castration

The mechanisms of cellular autophagy have been studied in the renal epithelium of male sticklebacks (Gasterosteus aculeatus L.) following castration. Two main types of alteration are described at the level of the proximal tubule cells. At first, the formation of endoplasmic reticulum whorls is observed, followed immediately by the secretion of lacunar progranules and by nucleolar modifications. These alterations lead to a progressive decrease of the glandular activity of the cells. The other main effect of castration is a general involution of the secretory granules still present in the cells. The involutive processes which lead to the complete destruction of the secretory material and, sometimes, of entire proximal cells, are described. In the collecting tubules, a marked and rapid decrease in glandular activity occurs, followed by disappearance of the mucous secretions. Small dense granules, supposedly lysosomes, are present. The processes described also appear to be characteristic of the normal involution of the renal cells occurring at the end of the breeding period. The findings strongly suggest that the male sex hormone may exert a double control on the renal cells in the stickleback, at both the cytoplasmic and nucleolar levels.     

Acute and subacute toxicity of atrazine to carp (Cyprinus carpio L.)

Investigations of acute and subacute atrazine toxicity in carp (Cyprinus carpio L.) were carried out. Acute toxicity was investigated in a semi-static test during a 96-hr exposition. The estimated LC-50 value was 18.8 mg/l. Subacute toxicity was investigated by exposing fish (carp) to different atrazine concentrations (1.5, 3.0, and 6.0 mg/l) for 14 days. Biochemical and histopathological changes in certain organs and tissues were investigated. The results show that atrazine leads to changes of varying intensity depending on the parameter tested, the organs and tissues examined, as well as the atrazine concentration. Biochemical changes were most prominent in the alkaline phosphatase, glutamic-oxaloacetic transaminase, and glutamic-pyruvic transaminase activities whereas the most severe histopathological changes were observed in the gills.     

Occurrence of somatostatin and insulin immunoreactivities in the stomach of sea bass (Dicentrarchus labrax L.): light and electron microscopic studies

Somatostatin (SST)- and insulin (INS)-immunoreactive (ir) cells were identified in the gut of sea bass (Dicentrarchus labrax) by immunofluorescence double staining and peroxidase-antiperoxidase (PAP) techniques for light microscopy and by immunogold method for electron microscopy using antisera to mammalian and fish peptides. SST-14 and SST-25 immunoreactivities coexisted in cells mainly located among the mucous neck cells of the gastric glands. Preabsorption controls showed that some SST-25- and, possibly, some SST-14-like peptides appeared in these cells. Immunoreactivity to fish INS, but not to mammalian INS (mINS) or insulin-like growth factor I (mIGF-I), was observed in all the SST-ir cells. The preabsorption controls suggest a cross-reaction of the fish INS antisera with SST-containing or type I cells. These cells displayed ovoid or round secretory granules with fibrous, medium electron-dense or homogeneous osmiophilic materials. Some gastric cells (type II) with round secretory granules of variable electron density, which were gold immunolabeled with bonito INS but not with mINS, mIGF-I, or SST antisera, were also found. INS-related peptide in type II cells of the sea bass stomach is suggested.     

Chemical constituents of Eclipta alba (L.) Hassk

Ecliptasaponin C (1), a new triterpenoid glucoside, was isolated together with daucosterol (2) and stigmasterol-3-O-glucoside (3) from Eclipta alba. Based on spectral analysis, chemical evidence and hydrolytic results, it's structure was deduced as 3-beta-O-beta-D-glucopyranosyl-19beta-hydroxy olean-12-ene-28-oic acid 28-O-beta-D-glucopyranoside, Compounds 2 and 3 were obtained from Eclipta for the fist time.     

Chemical constituents of Luffa cylindrica (L.) Roem

Six compounds were isolated from the fruits of Luffa cylindrica. They were identified as lucyosides C, E, F, H, a mixture of alpha-spinasterol and stigmasta-7,22,25-trien-3 beta-OH and a mixture of alpha-spinasteryl glucoside and delta 7,22,25-stigmasteryl-beta-D-glucoside by means of chemical evidence and spectral analysis.     

酸藤子化学成分的初步研究

[目的]初步研究酸藤子中可能含有的化学成分.[方法]采用常规化学反应鉴别方法检测酸藤子的化学成分.[结果]糖、多糖、苷类、鞣质、有机酸、黄酮、酚类、挥发油等检测项目出现正反应;其余项出现负反应现象.[结论]该研究为进一步进行该植物的生物活性成分研究提供了试验基础.     

Reproductive success after hibernation of the female water vole (Arvicola terrestris L.) of the different constitution types

Juvenile granulosa cell tumors (JGCTs) of the ovary are rare. They usually present in children and adolescents. About 90% are diagnosed in early stage (FIGO I) with a favorable prognosis. More advanced stages (FIGO II-IV) have a poor clinical outcome. We report two cases of short-term, disease-free survival of teenagers with Stage III JGCTs treated with aggressive debulking and thorough staging but conservative surgery relative to the uterus and contralateral tube and ovary plus carboplatin and etoposide chemotherapy. These results are encouraging, but the best treatment for extensive and recurrent disease has yet to be determined.     

Reactions of the goldfish (Carassius auratus auratus L.) to quantified mechanical and thermal stimuli

Goldfish can differentiate between mechanical and thermal stimuli components in combined stimulations. Reactions to heated thermode (deltaT = + 3 degrees C) differ from those to isotherm thermode by up to 30%. Additional pretension (0.5 p) increases the reaction more than double; at simultaneously varied temperature (deltaT = + 3 degrees C and + 5 degrees C), there is a further increase in reaction of 25% and 35%. The significance for the organism of the two stimuli components is discussed.     

High resolution RBA-banding comparison between early prometaphase chromosomes of cattle (Bos taurus L.) and goat (Capra hircus L.) at 700 band level

High resolution RBA-banded early prometaphase chromosomes of cattle (Bos taurus L.) and goat (Capra hircus L.), from thymidine synchronized lymphocyte cultures, are compared at a level of 700 bands per haploid genome, with the purpose of detecting the extent of banding homologies between the two species and improving the resolution level of the ISCNDA (1989) standardized RBA-banded karyotypes. The results demonstrate that, at this level of resolution, at least 10 autosomes can be fully homologized between the two species, namely chromosomes 11, 16, 17, 18, 20, 21, 22, 23, 24 and 26, whereas the remaining autosomes show variations in some regions which require further investigations on more elongated chromosomes. Such investigations should also involve the use of GTG, GBG and RBG-banding techniques. These variations concern basically the relative distance of the bands from the centromeres or telomeres, appearance of subbands, and clustering of some positive bands.     

Effect of total alkaloids of kudouzi (Sophora alopecuroides L.) on tolerance to anoxia in mice

To several anoxia mice models, total alkaloids of Kudouzi (TASa) can prolong their tolerance time (ip < 1/10, 1/5LD50/kg, P < 0.05-0.01). In the experiment of myocardial ischemia induced by pituitrin, TASa decreased significantly the ST change in ECG (P < 0.05). The acute LD50 of TASa by ip was found to be 130.66 +/- 22.64 mg/kg for mice.     

Oral glucose tolerance test with a mixture of oligosaccharides after partial gastrectomy (author's transl)

Fourteen non-diabetic male patients undergoing partial gastrectomy for ulcer disease were investigated with oral glucose tolerance test using a 100 g mixture of oligosaccharides. Partial gastrectomy had been performed between 1 and 3 years ago. Compared to seven healthy male control subjects, patients had significant higher blood glucose levels at 30 and 60 min and a more rapid descent, so that at 120 and 180 min no differences were found between patients and control subjects. With the usual criteria (blood glucose levels at 120 and 180 min) the non-diabetic patients with partial gastrectomy showed normal test results.