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D Ren

Publications and source records attributed to D Ren.

63 records · Page 4Linked to original sources
PubMed1995

[Expression of chemically synthesized hybrid genes of Plasmodium falciparum and preliminary characterization of expressed products].

The chemically synthesized hybrid genes HGFC and HGFCAC were respectively recombinated with expression vector pWR450-1 and transferred into Escherichia coli. After adding IPTG to the cultural media, the bacteria harboring recombinant plasmid expressed the fusion proteins of exogenous gene products and partial amino acid of beta-galactosidase. The molecular weights of the two fusion proteins were 65 kDa and 77 kDa, respectively. The expressed fusion proteins could be recognized by antibodies of rabbit anti-RESA peptide EENVEHDA by Western blotting, indicating that the fusion proteins harbored the antigenic epitopes of Plasmodium falciparum.

Animals↗
PubMed1995

Cloning and characterization of a calcium channel alpha 1 subunit from Drosophila melanogaster with similarity to the rat brain type D isoform.

We report the complete sequence of a calcium channel alpha 1 subunit cDNA cloned from a Drosophila head cDNA library. This cDNA encodes a deduced protein containing 2516 amino acids with a predicted molecular weight of 276,493. The deduced protein shares many features with vertebrate homologs, including four repeat structures, each containing six transmembrane domains, a conserved ion selectivity filter region between transmembrane domains 5 and 6, and an EF hand in the carboxy tail. The Drosophila subunit has unusually long initial amino and terminal carboxy tails. The region corresponding to the last transmembrane domain (IVS6) and the adjacent cytoplasmic domain has been postulated to form a phenylalkylamine-binding site in vertebrate calcium channels. This region is conserved in the Drosophila sequence, while domains thought to be involved in dihydropyridine binding show numerous changes. The Drosophila subunit exhibits 78.3% sequence similarity to the rat brain type D calcium channel alpha 1 subunit, and so has been designated as a Drosophila melanogaster calcium channel alpha 1 type D subunit (Dmca1D). In situ hybridization shows that Dmca1D is highly expressed in the embryonic nervous system. Northern analysis shows that Dmca1D cDNA hybridizes to three size classes of mRNA (9.5, 10.2, and 12.5 kb) in heads, but only two classes (9.5 and 12.5 kb) in bodies and legs. PCR analysis suggests that the Dmca1D message undergoes alternative splicing with more heterogeneity appearing in head and embryonic extracts than in bodies and legs.

Amines↗
PubMed1995

[The inhibitory effects of immune sera against two recombinant hybrid antigens on the growth of Plasmodium falciparum in vitro].

The inhibitory effects of rabbit immune sera against two recombinant hybrid antigens (C and CAC) of Plasmodium falciparum to the multiplication and development of in vitro cultured P. falciparum parasites were tested. Although both of anti-C and anti-CAC immune sera had inhibitory effect on parasites, the anti-CAC serum showed much greater effect than that of anti-C serum (P < 0.05). The inhibitory capacities in the sera to parasites were enhanced with the increase in the serum concentration as well as with the prolongation of the incubation time of the sera with the parasites. It was shown that after 72 h incubation of the anti-CAC serum with the parasites at the concentration of 1%, 10% and 20%, the inhibition rates were 15%, 54% and 82%, respectively. The immune sera caused the dispersion of parasite cytoplasm, atrophy of parasites, agglutination of free merozoites and degeneration of schizonts, suggesting that the hybrid antigen could produce multi-functional protective antibodies against antigens of Plasmodium falciparum.

Animals↗
PubMed1995

[Study on neuropeptide Y-containing innervation of cerebral small arteries and arterioles in spontaneously hypertensive rat].

To comprehend the relationship between the distribution of perivascular neuropeptides and remodified structure of arterioles in hypertension, we applied the technique of sheeting from pia matter of spontaneously hypertensive rats (SHR) to reveal branches at all levels of the vascular network so as to make an overall and stereoscopic observation of the vasculature. In addition, immunohistochemical technique and image analyser were applied to analyse qualitatively and quantitatively neuropeptide Y(NPY)-containing innervation in the vasculature. Findings revealed that the surface density of NPY-containing innervation and integral luminous density of positive reaction particle for anti-NPY in middle cerebral artery and its branches -small arteries and arterioles of SHR were significantly increased as compared with findings in Wistar Kyoto. The results reveal that an increase in density of NPY-containing innervation of cerebral small arteries and arterioles intensifies action of nutritive adjustment of vascular smooth muscle and is clearly related with increase of contractive excitability of artery, hypertrophy of artery, smooth muscle cells and the development of hypertension.

Animals↗
PubMed1994

Cloning and functional expression of a neuronal calcium channel beta subunit from house fly (Musca domestica).

The primary structure of a calcium channel beta subunit (beta M) from housefly (Musca domestica) has been deduced by cDNA cloning and sequence analysis. The open reading frame encodes a 441-amino acid polypeptide with a calculated molecular mass of 48,755 Da. Whole-mount in situ hybridization indicates that beta M mRNA is predominantly expressed in neuronal tissues. Transcription of beta M mRNA is evident from stage 13/14 of embryogenesis up to adulthood. Different expression patterns of splice variants were found in larvae and in adult fly heads. Amino acid identity between beta M and mammalian beta subunits is lower (66-68%) than within mammalian beta subunits (74-80%). Calculation of a phylogenetic tree indicates that beta M is an ancestral form of the four distinct beta subunit gene products identified in mammalian tissues so far. Despite these sequence differences, beta M is able to enhance endogenous calcium channel activity in Xenopus laevis oocytes as well as dihydropyridine binding to membranes from COS 7 cells transfected with rabbit heart alpha 1 cDNA in the same manner as was previously shown for mammalian beta subunits.

Alternative Splicing↗
PubMed1994

Identification and characterization of Marek's disease virus genes homologous to ICP27 and glycoprotein K of herpes simplex virus-1.

We have identified two Marek's Disease Virus (MDV) genes within the EcoRI-B fragment of MDV-GA genomic DNA. EcoRI-B is 11.3-kb long and maps within the long unique region of MDV genomes. A 3.2-kb fragment of EcoRI-B has been sequenced and contains two open reading frames, ORF53 and ORF54. ORF53 (MDV gK), a homolog to HSV-1 glycoprotein K (gK), is 1062 nucleotides long and encodes 354 amino acids (39.5 kDa). ORF54, designated MDV ICP27, based on significant similarity to HSV-1 ICP27, is 1419 nucleotides long and encodes 473 amino acids (54.5 kDa). In Northern blot hybridization, two overlapping transcripts (2.9 and 1.6 kb) were detected in MDV-infected DEF cells treated with cycloheximide, suggesting that both transcripts belong to the immediate-early gene family. Amino acid sequence analysis of MDV gK shows some common glycoprotein features, including a putative N-terminal signal sequence, four N-linked glycosylation sites, and four potential transmembrane domains. Comparison of the predicted amino acid sequence of MDV ICP27 with that of HSV-1 ICP27 and VZV ORF4 shows a high degree of conservation within the C-terminus. The C-terminal region of HSV-1 ICP27 has been demonstrated to be critical to its function. A conserved zinc finger metal-binding motif C(442)-X4-C(447)-X13-H(461)-C(467) was also found in the C-terminus of MDV ICP27. Furthermore, MDV ICP27 upstream sequences contain four copies of consensus sequence elements similar to the tegument protein target sequence TAATGARAT. TrpE-ICP27 fusion protein was expressed in Escherichia coli, and rabbit antisera were generated using purified fusion protein. A 55-kDa protein has been detected in both MDV-GA- and Md11-infected cells using immunoblot analysis.

Amino Acid Sequence↗
PubMed1993

Clinical and experimental studies of JPYS in reducing side-effects of chemotherapy in late-stage gastric cancer.

This article reports a research project undertaken for more than 16 years by the Cancer Department of Guang An Men Hospital. Tonic Jian Pi Yi Shen (JPYS), which nourishes the spleen and kidney, was used in combination with chemotherapy in the treatment of late stage gastric cancer patients for the purpose of promoting completion of the chemotherapeutic course, improving the general condition, ameliorating the reaction in the digestive system, protecting hemopoiesis and strengthening immunocompetence. The results of lab experiments were found to coincide with those of clinical application.

Adenocarcinoma↗
PubMedDate not supplied

In vivo tissue distribution of fibroblast growth factor-1 after intraarterial delivery.

The clinical applicability of fibroblast growth factor-1 (FGF-1) plus heparin delivery in optimizing the healing of both autogenous vein and synthetic vascular grafts has been suggested. The authors have reported enhanced endothelial cell proliferation, concurrent increased capillarization, and minimal intimal hyperplasia using suspensions of FGF-1 and heparin impregnated onto expanded polytetrafluoroethylene grafts. The current study characterizes the tissue distribution of 125I-FGF-1 delivered by continuous intraarterial infusion. 125I-FGF-1 delivered by continuous intraarterial infusion. 125I-FGF-1 (1.1 ng) and heparin (28 U) were continuously infused into the thoracic aorta via the proximal end of the ligated left carotid artery for 24 hr in four New Zealand white rabbits using an Alzet (Alza Corp., Palo Alto, CA) osmotically activated pumping device. Rabbits were sacrificed after 24 hr, exsanguinated, and biopsies taken from the liver, kidneys, spleen, lungs, heart, thyroid gland, muscle, and fat. These samples were assayed for radioactivity and results expressed as cpm 125I/gram of both wet and dry weight of tissue. 125I-FGF-1 uptake (cpm/g dry wt.) was greatest in the thyroid (551.1 +/- 131.4). This was 2.5-5.5 x greater (p < or = 0.01) than those organs with intermediate uptake (lungs, liver, kidneys, spleen, and heart). Lowest uptake was noted in the blood, muscle, and fat. A similar distribution pattern was found in wet weight comparisons. Total organ 125I-FGF-1 content was greatest in the liver at 818.1 +/- 176.3 cpm (p < or = 0.002) and intermediate in the lungs (204.7 +/- 38.5 cpm) and kidneys (191.2 +/- 11.9 cpm). Although no FGF-1-induced toxicity has yet been reported, these results will allow for future tissue-specific toxicology studies before clinical trials.

Animals↗