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61.
Nine species of marine algae have been assessed for the presence of novel hemagglutinins not extractable with buffer, unless the algal tissue was pretreated with Pronase. All species examined contained hemagglutinins, indicating the existence of a novel group of hemagglutinins which differed from those reported previously in marine algae.  相似文献   
62.
63.
Previously we suggested that four proteins including aldolase and triose phosphate isomerase (TPI) evolved with approximately constant rates over long periods covering the whole animal phyla. The constant rates of aldolase and TPI evolution were reexamined based on three different models for estimating evolutionary distances. It was shown that the evolutionary rates remain essentially unchanged in comparisons not only between different classes of vertebrates but also between vertebrates and arthropods and even between animals and plants, irrespective of the models used. Thus these enzymes might be useful molecular clocks for inferring divergence times of animal phyla. To know the divergence time of Parazoa and Eumetazoa and that of Cephalochordata and Vertebrata, the aldolase cDNAs from Ephydatia fluviatilis, a freshwater sponge, and the TPI cDNAs from Ephydatia fluviatilis and Branchiostoma belcheri, an amphioxus, have been cloned and sequenced. Comparisons of the deduced amino acid sequences of aldolase and TPI from the freshwater sponge with known sequences revealed that the Parazoa–Eumetazoa split occurred about 940 million years ago (Ma) as determined by the average of two proteins and three models. Similarly, the aldolase and TPI clocks suggest that vertebrates and amphioxus last shared a common ancestor around 700 Ma and they possibly diverged shortly after the divergence of deuterostomes and protostomes.  相似文献   
64.
Ninety-six alleles (36 alleles of Japanese and 60 of Caucasian origin) from forty-eight patients with mucopolysaccharidosis IVA were investigated for structural gene alterations using Southern blot analysis. All patients had a previously demonstrated deficiency of N-acetylgalactosamine-6-sulfate-sulfatase and exhibited a wide spectrum of clinical severity. Initially, using the fulllength cDNA as a probe, five of 36 chromosomes from the Japanese patients revealed similar rearrangements with respect to DNA digested with BamHI, SacI, and XhoI. Subsequent analysis using seven genomic fragments, covering the entire gene, enhanced the detection of aberrant fragments produced by the above restriction enzymes. Conversely, the 60 chromosomes of Caucasian origin revealed no evidence of large structural rearrangements when analyzed by these methods. There was a statistically significant difference between the two populations (P < 0.01). A severely affected Japanese patient showed structural rearrangements on both chromosomes by means of BamHI blots. An 8.0-kb fragment and a highly polymorphic 7.0-kb to 11.0-kb fragment present in normal individuals disappeared and two aberrant fragments of 11.5 kb and 12.0 kb were observed. Three other Japanese patients also showed these two aberrant fragments, in addition to the normal fragment pattern, and were thus heterozygous for this rearrangement. Interpretation of Southern blots was difficult because of the complexity of polymorphic bands resulting from variable number of tandem repeat elements. However, by utilizing these aberrant fragments or polymorphic bands, carrier detection was effective, even in families with poorly characterized mutations. Hybridization with probe MG-A (5end genomic probe in intron 1) showed a 8.4-kb fragment in BamHI blots of one Japanese and one Caucasian patient; XhoI, SacI, and EcoRI blots were normal. Since this BamHI alteration was also observed in one normal control, it appears to be a rare nonpathological polymorphism.  相似文献   
65.
Seven different restriction fragment length polymorphisms (RFLPs) at the N-acetylgalactosamine-6-sulfate sulfatase (GALNS) locus were analyzed using Southern blotting and polymerase chain reaction based techniques to search for the frequency of each RFLP produced by StyI, SphI, HaeIII, StuI, HapII, XhoI, and BamHI restriction endonucleases, respectively, in 36 mutant alleles, including two sibling cases and 100 normal alleles. Calculation of heterozygosity indexes showed that these RFLPs were polymorphic, ranging from 0.31 to 0.69 in mucopolysaccharidosis IVA (MPS IVA) patients compared with 0.21 to 0.65 in normal individuals. There was some significant difference in several RFLPs and in the combination with four kinds of RFLPs (SphI, StuI, HapII, XhoI polymorphisms). The normal alleles were composed of 13 different RFLPs haplotypes; the most common among the Japanese population carrying normal alleles was haplotype 8 (bDEF1) (31.3%), the others being dispersed. The same haplotype 8 was the most frequent in the mutant alleles (44.4%), with seven further haplotypes. These findings revealed the striking variety of polymorphic haplotypes in the MPS IVA gene. By using these five kinds of RFLPs, we examined the theoretical informativity of haplotype analysis in heterozygote detection in nine unrelated MPS IVA families and ten unrelated normal families. All the members of the MPS IVA families studied were diagnosed as a patient, carrier, or noncarrier. We propose that prenatal diagnosis or family analysis in cases in which mutations have not been characterized is now feasible.  相似文献   
66.
In order to investigate the re-epithelialization process during wound healing, the hair on the back of guinea pigs was shaved and then excisional wounds were made through the entire thickness of the skin. Histological changes were observed and changes in the expression of different cytokeratin polypeptides were examined using an immunohistochemical technique. Immunohisto chemical study revealed that the proliferating and migrating keratinocytes expressed the same cytokeratins as the basal cells of normal epidermis. In addition, the entire epidermis of fairly remote areas from the edges of the wound where no thickening was observed showed a temporarily abnormal staining pattern. The suprabasal cells in the regenerating epidermis temporarily expressed cytokeratins not only specific for suprabasal cells but also specific for basal cells. The cytokeratins expressed in normal basal keratinocytes were also present in the thickened granular layers. These data indicate that the expression of cytokeratins in the epidermal keratinocytes (even in fairly remote areas from the wound edges) changes during wound healing, that the origin of the migrating keratinocytes from the remaining epidermis seems to be the basal cells in the epidermis, and that the appearance of keratohyalin granules is not related to changes in cytokeratin expression.  相似文献   
67.
Stimulation of synovial cell prostaglandin production by a factor obtained from casein-induced peritoneal polymorphonuclear (PMN) cells has been investigated. Both the extract and short time cultured medium of rat peritoneal PMN cells stimulate prostaglandin (PG)E2 production as well as collagenase production in the culture of rat synovial cells. PGE2 production by the cells in the presence of the PMN factor is much faster (5 to 24 hr) than collagenase production (24 hr or later, Biomedical Res. 3, 506-516, 1982). This stimulating factor is confirmed to be derived from PMN cells, based on the purification of the cells from peritoneal exudate cells by the Ficoll-Urographin method. Elution profile of the factor on gel filtration has indicated that both PGE2 and collagenase productions by synovial cells are stimulated by the same effluent fractions corresponding to molecular weights of 15,000 - 20,000 daltons and 30,000 - 40,000 daltons. These results suggest that PMN cells are involved in PG production as well as collagenase production in the inflamed tissue by stimulating connective tissue cells such as synovial cells.  相似文献   
68.
The effects of ionophoretically applied N-methyl-DL-aspartate (NMDA) and aspartate on identified pyramidal neurons in rat piriform cortex were examined in isolated, submerged, and perfused brain slices. NMDA was more potent than aspartate in eliciting neuronal discharge. Perfusion of the acidic amino acid antagonists, DL-2-amino-5-phosphonovalerate (APV), 10(-6) or 10(-5) M, DL-2-amino-7-phosphonoheptanoate (APH), 10(-5) M, and gamma-D-glutamylglycine (gamma DGG), 10(-5) M, selectively blocked the response to NMDA without effect on the response to aspartate. At higher concentrations which blocked responses to both NMDA and aspartate, gamma DGG blocked kainate responses and depressed glutamate and quisqualate responses. These results suggest that in piriform neurons NMDA and aspartate act at distinct receptor sites, not a common receptor site, and that both of these sites are distinct from those that mediate responses to glutamate, quisqualate, and kainate.  相似文献   
69.
Luciferase from the anthozoan coelenterate Renilla reniformis (Renilla luciferin:oxygen 2-oxidoreductase (decarboxylating), EC 1.13.12.5.) catalyzes the bioluminescent oxidation of Renilla luciferin producing light (lambdaB 480 nm, QB 5.5%), oxyluciferin, and CO2 (Hori, K., Wampler, J.E., Matthews, J.C., and Cormier, M.J. (1973), Biochemistry 12, 4463). Using a combination of ion-exchange, molecular-sieve, sulfhydryl-exchange, and affinity chromatography, luciferase has been purified, approximately 12 000-fold with 24% recovery, to homogeneity as judged by analysis with disc and sodium dodecyl sulfate-polyacrylamide gel electrophoresis, gel filtration, and ultracentrifugation. Renilla luciferase is active as a nearly spherical single polypeptide chain monomer of 3.5 X 10(4) daltons having a specific activity of 1.8 X 10(15) hp s-1 mg-1 and a turnover number of 111 mumol min-1 mumol-1 of enzyme. This enzyme has a high content of aromatic and hydrophobic amino acids such that it has an epsilon280nm 0.1% of 2.1 and an average hydrophobicity of 1200 cal residue-1. The high average hydrophobicity of luciferase, which places it among the more hydrophobic proteins reported, is believed to account, at least in part, for its tendency to self-associate forming inactive dimers and higher molecular weight species.  相似文献   
70.
Electron paramagnetic resonance (EPR) spectra of the glycosylated minor hemoglobins A1a-1, A1a-2, A1b and A1c and the major hemoglobin A0 in the nitrosyl form have been obtained in the absence and presence of inositol hexaphosphate. In the absence of inositol hexaphosphate, nitrosyl hemoglobins A1a-1, A1a-2 and A1b exhibited a triplet hyperfine structure centered at g = 2.009 which has been shown to be diagnostic of the low affinity (T) quaternary structure. Addition of inositol hexaphosphate to nitrosyl hemoglobins A0, A1c, A1b and A1a-2 developed a triplet hyperfine structure of the EPR spectra but the magnitude of the hyperfine was decreased in the order of hemoglobins A0, A1c, A1b and A1a-2. However, inositol hexaphosphate had essentially no effect on the EPR spectrum of nitrosyl hemoglobin A1a-1. The present results account qualitatively for the oxygen binding properties of these glycosylated minor hemoglobins in the framework of a two-state allosteric model.  相似文献   
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