[Establishing the hemodialysis channel by vein-vein puncture with the aid of a sleeve band of child sphygmomanometer].
Explore the source record for details and available documents.
Blood Pressure Monitors↗
Biomedical subjects
H Xiao
Publications and source records attributed to H Xiao.
Effect of age on marrow macrophage number and function.
Employing flow cytometry and a monoclonal antibody against the murine macrophage antigen, Mac-1, we found a significant increase in the number of marrow macrophages in aged mice. This was reflected as significant increase with age in the number of alpha-naphthyl acetate esterase positive cells, as well as in colony forming unit-macrophage (CFU-M) progenitor cells. Macrophages from the marrow of old mice generated significantly less tumor necrosis factor alpha (TNF alpha) than did macrophages from young mice, either spontaneously or when activated by granulocyte-macrophage colony stimulating factor (GM-CSF). Furthermore, conditioned medium (CM) derived from either marrow or peritoneal macrophages of old mice caused less suppression of burst forming unit-erythroid (BFU-E) colony growth than did CM obtained from young mice. Aging, therefore, is associated with an increase in the number of marrow macrophages that have an impaired ability to generate or release cytokines. The increase in macrophage number may reflect a compensation for their reduced function. Altered macrophage number and function may contribute to the age-related decline in hematopoietic reserve capacity.
Aging↗
Targeting foreign proteins to human immunodeficiency virus particles via fusion with Vpr and Vpx.
The human immunodeficiency virus type 1 (HIV-1) and HIV-2 Vpr and Vpx proteins are packaged into virions through virus type-specific interactions with the Gag polyprotein precursor. To examine whether HIV-1 Vpr (Vpr1) and HIV-2 Vpx (Vpx2) could be used to target foreign proteins to the HIV particle, their open reading frames were fused in frame with genes encoding the bacterial staphylococcal nuclease (SN), an enzymatically inactive mutant of SN (SN*), and chloramphenicol acetyltransferase (CAT). Transient expression in a T7-based vaccinia virus system demonstrated the synthesis of appropriately sized Vpr1-SN/SN* and Vpx2-SN/SN* fusion proteins which, when coexpressed with their cognate p55Gag protein, were efficiently incorporated into virus-like particles. Packaging of the fusion proteins was dependent on virus type-specific determinants, as previously seen with wild-type Vpr and Vpx proteins. Particle-associated Vpr1-SN and Vpx2-SN fusion proteins were enzymatically active, as determined by in vitro digestion of lambda phage DNA. To determine whether functional Vpr1 and Vpx2 fusion proteins could be targeted to HIV particles, the gene fusions were cloned into an HIV-2 long terminal repeat/Rev response element-regulated expression vector and cotransfected with wild-type HIV-1 and HIV-2 proviruses. Western blot (immunoblot) analysis of sucrose gradient-purified virions revealed that both Vpr1 and Vpx2 fusion proteins were efficiently packaged regardless of whether SN, SN*, or CAT was used as the C-terminal fusion partner. Moreover, the fusion proteins remained enzymatically active and were packaged in the presence of wild-type Vpr and Vpx proteins. Interestingly, virions also contained smaller proteins that reacted with antibodies specific for the accessory proteins as well as SN and CAT fusion partners. Since similar proteins were absent from Gag-derived virus-like particles and from virions propagated in the presence of an HIV protease inhibitor, they must represent cleavage products produced by the viral protease. Taken together, these results demonstrate that Vpr and Vpx can be used to target functional proteins, including potentially deleterious enzymes, to the human or simian immunodeficiency virus particle. These properties may be exploitable for studies of HIV particle assembly and maturation and for the development of novel antiviral strategies.
Amino Acid Sequence↗
Recruiting TATA-binding protein to a promoter: transcriptional activation without an upstream activator.
The binding of TATA-binding protein (TBP) to the TATA element is the first step in the initiation of RNA polymerase II transcription from many promoters in vitro. It has been proposed that upstream activator proteins stimulate transcription by recruiting TBP to the promoter, thus facilitating the assembly of a transcription complex. However, the role of activator proteins acting at this step to stimulate transcription in vivo remains largely speculative. To test whether recruitment of TBP to the promoter is sufficient for transcriptional activation in vivo, we constructed a hybrid protein containing TBP of the yeast Saccharomyces cerevisiae fused to the DNA-binding domain of GAL4. Our results show that TBP recruited by the GAL4 DNA-binding domain to promoters bearing a GAL4-binding site can interact with the TATA element and direct high levels of transcription. This finding indicates that binding of TBP to promoters in S. cerevisiae is a major rate-limiting step accelerated by upstream activator proteins.
Base Sequence↗
[A study of c-src gene express product pp60c-src in esophageal carcinoma].
Using the specific monoclonal antibody of c-src gene express product, pp60c-src (McAb 327), we studied immunohistochemically in this experiment 35 cases of the esophageal squamous cell carcinomas and 22 adjacent carcinoma tissues. The positive rates of pp60c-src in the squamous cell carcinomas of the esophaguses, the proliferative and the normal squamous epithelis adjacent to the carcinoma were 65.7% (23/35), 100.0% (15/15), and 57.1% (4/7), respectively. There was significant difference among them statistically (P < 0.05). And the express amount of pp60c-src in the esophageal squamous cell carcinoma was higher than those in the proliferative and normal squamous epithelia adjacent to the carcinoma. The positive rates of pp60c-src of the esophageal squamous cell carcinoma with different differentiation grades I, II and III were 80.0% (8/10), 68.4% (13/19), and 33.3% (2/6), respectively. No significant difference was found among them statistically (P > 0.05). The higher the differentiation grade of the esophageal squamous cell carcinoma, the more the express amount of pp60c-src (P < 0.005). The results suggested that the activation and express of c-src gene be associated with the initiation and development of the esophageal squamous cell carcinoma; the express amount of pp60c-src increased in the process and was associated with the differentiation of esophageal squamous cell carcinoma.
Antibodies, Monoclonal↗
[A study on serum autoantibodies against inner ear tissue in the blood of patients with inner ear disorders of unknown etiology].
Membranous labyrinth antigen of guinea pigs was prepared. The sera of 33 patients with inner ear disorders of unknown etiology were examined by immunoblotting assay. The autoantibodies against inner ear antigen were found in patient's sera (30.3%). This indicated that the autoimmune activity may play a role in the development of some cases of these diseases. The detection of autoantibodies to inner ear antigen will be of great value to further study on the action of autoimmunological factor contributing to inner ear disorders of unknown etiology.
Adolescent↗
[Ultrastructural observation of tendonization of artificial tendon 109HH in rabbit].
Ten New Zealand rabbits were divided into 5 groups at random. Calcaneal tendons were cut bilaterally, then atificial tendon 109HH was used to connect the two ends of the cut tendon. Ultrastructural changes of control group and experimental groups at 2, 6, 12, 28 weeks after section were observed. The results showed that fibroblast proliferated and a lot of ribosome and RER appeared in plasm during 2 approximately 6 weeks, indicating artificial tendon caused fibroblast proliferation. During this period, fibroblast over synthesized collagenous protein and the synthesis of collagenous fibers peaked. During 12-28 weeks, the number of fibroblasts and the synthesis of collagenous protein decreased. Finally, fibroblasts became inactive tendon cells. With the formation of new tendons, the artificial tendens were degradated and absorbed, and disappeared after 12 weeks. The new tendon fibers became thicker and had the correct direction through reconstruction. The structure and function of new tendons could be restored to be consistent with normal values.
Animals↗
[Western blot analysis of serum autoantibodies against inner ear antigens in patients with systemic lupus erythematosus].
The purpose of this study was to identify the cross-reacting autoantibodies against inner ear antigens in patients with systemic lupus erythematosus (SLE). Inner ear antigens of guinea pigs were prepared. The sera from 18 patients with SLE without hearing loss and 11 normal subjects were analysed by immunoblotting assay. The results showed that 16 patients with SLE had cross-reacting autoantibodies, while 11 normal objects were all negative (P < 0.01), these suggested that the inner ear may be one of the targets involved by SLE. To further investigate the correlation between hearing status of SLE and autoantibodies against inner ear antigens will be of great value to explore the pathogenesis of inner ear insults resulted from certain systemic autoimmune diseases.
Adolescent↗
Interleukin-6 prevents dexamethasone-induced myeloma cell death.
The effects of dexamethasone on the growth of four human multiple myeloma cell lines were studied. In addition, the effects on the expression of interleukin-6 (IL-6) and IL-6 receptor (IL-6R) genes were investigated by the use of reverse-transcriptase polymerase chain reaction. Dexamethasone (Dex) concentrations of 10(-7) to 10(-6) mol/L inhibited IL-6 gene expression in three of four cell lines studied, whereas the higher concentration of the hormone inhibited also IL-6R gene expression. Dex effects were modulated through the glucocorticoid receptor (GR). Dex treatment resulted in killing of sensitive cells associated with DNA fragmentation, which could be reversed by concomitant treatment with IL-6. The reversal of Dex-mediated effects by IL-6 did not result from an inhibition of GR function as measured by receptor nuclear translocation or Dex-regulated reporter gene function. These results indicate that blockage of the IL-6 signaling pathway is essential for effective myeloma cell kill by Dex.
Base Sequence↗
The upstream activator CTF/NF1 and RNA polymerase II share a common element involved in transcriptional activation.
The carboxy-terminal domain (CTD) of the largest subunit of RNA polymerase II consists of tandem repeats of a heptapeptide with the consensus YSPTSPS. It has been shown that the heptapeptide repeat interacts directly with the general transcription factor TFIID. We report here that the CTD activates transcription when fused to the DNA-binding domain of GAL4. More importantly, we find that the proline-rich transcriptional activation domain of the CCAAT-box-binding factor CTF/NF1 contains a sequence with striking similarity to the heptapeptide repeats of the CTD. We show that this CTD-like motif is essential for the transcriptional activator function of the proline-rich domain of CTF/NF1. Deletion of and point mutations in this CTD-like motif abolish the transcriptional activator function of the proline-rich domain, while natural CTD repeats from RNA polymerase II are fully functional in place of the CTD-like motif. We further show that the proline-rich activation domain of CTF/NF1 interacts directly with the TATA-box-binding protein (TBP), and that a mutation in the CTD-like motif that abolishes transcriptional activation reduces the affinity of the proline-rich domain for TBP. These results demonstrate that a class of proline-rich activator proteins and RNA polymerase II possess a common structural and functional component which can interact with the same target in the general transcription machinery. We discuss the implications of these results for the mechanisms of transcriptional activation in eucaryotes.
Amino Acid Sequence↗
Fine structure analyses of the Drosophila and Saccharomyces heat shock factor--heat shock element interactions.
Heat shock genes are activated by the binding of the heat shock transcription factor (HSF) to heat shock elements (HSEs), consisting of arrays of the 5-bp unit NGAAN arranged as inverted repeats. Here, we have investigated the interaction of the 5-bp unit with HSFs of Drosophila and Saccharomyces. Mutations within the conserved, central trinucleotide GAA reduce the relative binding affinity of both HSFs. In addition, the base at position 1 (N1) also influences binding, with a strong preference for an A at this position. Methylation interference initially indicated that HSF contacts A1 in the minor groove, but interacts with the immediately adjacent base G2 in the major groove. Further characterization of this apparently abrupt minor to major groove transition by substitution of A1 with an inosine, shows that HSF contacts A1 in the major groove. We offer an explanation for this apparent contradiction and propose that HSF recognizes the HSE primarily through contacts within the major groove of the DNA helix. Finally, based on these observations and a re-evaluation of the base frequencies and criteria for consensus sequence assignment, we propose that the sequence AGAAN more accurately represents the consensus HSE motif.
Animals↗
Optical remote sensing for air pollutants--review.
Air monitoring techniques need to be simple, unobtrusive, acquire real-time data, have increased sensitivity, and the ability to analyze many compounds simultaneously. Optical remote sensing techniques address many of these criteria for air monitoring methods. Optical remote sensing uses light energy between ultraviolet and midinfrared to detect and measure contaminants in situ. While optical remote monitoring techniques provide similar monitoring accuracy compared to conventional monitoring methods, they also provide certain unique advantages. Advantages and disadvantages of specific optical remote sensing techniques is discussed in this review, which focuses on the techniques most useful to the industrial hygiene profession. Detailed information about every technique will not be supplied; rather the review attempts to provide an understanding of the development of the remote sensing techniques, and briefly explains typical applications, so that readers can understand and evaluate applications appropriate to their work.
Air Pollutants↗
Genes encoding general initiation factors for RNA polymerase II transcription are dispersed in the human genome.
General transcription factors are required for accurate initiation of transcription by RNA polymerase II. Human cDNAs encoding subunits of these factors have been cloned and sequenced. Using fluorescence in situ hybridization (FISH), we show here that the genes encoding the TATA-box binding protein (TBP), TFIIB, TFIIE alpha, TFIIE beta, RAP30, RAP74 and the 62 kDa subunit, of TFIIH are located at the human chromosomal bands 6q26-27, 1p21-22, 3q21-24, 8p12, 13q14, 19p13.3 and 11p14-15.1, respectively. This dispersed localization of a group of functionally related gene provides insights into the molecular mechanism of human genome evolution and their possible involvement in human diseases.
Cells, Cultured↗
Abundant but inactive-state gp140proto-trk is expressed in neuroblastomas of patients with good prognosis.
Steady-state levels of gp140proto-trk in cell lines and tumor tissues of neuroblastoma were examined by immunoblotting with anti-gp140proto-trk. The level of gp140proto-trk varied but showed good correlations with the stage of the tumor and the age of the patients at the time of diagnosis. Moreover, patients with higher expression of gp140proto-trk clearly had a far better survival rate than those with lower expression, suggesting that suppression of gp140proto-trk strongly correlates with the malignant conversion of the tumor. However, we found that neither autophosphorylation of gp140proto-trk nor tyrosine phosphorylation of cellular proteins was elevated in tumors of the higher expression group. These results suggest that gp140proto-trk does not actively participate in the process of transformation or the suppression of malignant conversion. Rather, the higher level of gp140proto-trk may reflect the greater level of differentiation of tumor cells.
Age Factors↗
Binding of basal transcription factor TFIIH to the acidic activation domains of VP16 and p53.
Acidic transcriptional activation domains function well in both yeast and mammalian cells, and some have been shown to bind the general transcription factors TFIID and TFIIB. We now show that two acidic transactivators, herpes simplex virus VP16 and human p53, directly interact with the multisubunit human general transcription factor TFIIH and its Saccharomyces cerevisiae counterpart, factor b. The VP16- and p53-binding domains in these factors lie in the p62 subunit of TFIIH and in the homologous subunit, TFB1, of factor b. Point mutations in VP16 that reduce its transactivation activity in both yeast and mammalian cells weaken its binding to both yeast and human TFIIH. This suggests that binding of activation domains to TFIIH is an important aspect of transcriptional activation.
Fungal Proteins↗
A highly conserved domain of RNA polymerase II shares a functional element with acidic activation domains of upstream transcription factors.
We report here that the largest subunit of yeast RNA polymerase II contains an acidic domain that is similar to acidic activators of transcription. This domain includes the highly conserved homology box H. A hybrid protein containing this acidic domain fused to the DNA-binding domain of GAL4 is a potent activator of transcription in the yeast Saccharomyces cerevisiae. Interestingly, mutations that reduce the upstream activating activity of this acidic domain also abolish the normal function of RNA polymerase II. Such functional defects can be rescued by the acidic activation domains of VP16 and GAL4 when inserted into the mutant derivatives of RNA polymerase II. We further show that this acidic domain of RNA polymerase II interacts directly with two general transcription factors, the TATA-binding protein and TFIIB, and that the acidic activation domain of VP16 can compete specifically with the acidic domain of the RNA polymerase for these interactions. We discuss the implications of this finding for the mechanisms of transcriptional activation in eucaryotes.
Amino Acid Sequence↗
A search for gli expression in tumors of the central nervous system.
The gli gene was originally isolated from DNA amplified in double minutes in a glioblastoma (D259MG). Using a sensitive RNA-RNA hybridization, we tested a series of central nervous system tumors for expression of the gli gene. These included 8 glioblastoma cell lines, plus cell cultures of 5 glioblastomas, 4 anaplastic astrocytomas, 3 different ependymal tumors, a malignant meningioma, and a medulloblastoma. Two normal glial cell cultures were also examined. There was no gli expression in any of these specimens. In glioblastoma D259MG, approximately 130 molecules of gli mRNA per cell were present and the half-life of the mRNA was approximately 5 h. By reverse transcription and PCR, gli mRNA was observed in 4 cell lines and in normal human glial cells, but the level was estimated to be less than one five hundredth of that in the D259MG cell line. The results suggest that gli expression in central nervous system tumors is a rare event and mostly likely associated with amplification of the gene.
Central Nervous System Neoplasms↗
The identification of four protein kinase C isoforms in human glioblastoma cell lines: PKC alpha, gamma, epsilon, and zeta.
Levels of protein kinase C (PKC) isoforms in eight human glioblastoma cell lines and two normal human glial cell cultures were determined. Earlier studies identified PKC-alpha and PKC-gamma in these cell lines but PKC-beta was not present. In this study, PKC-epsilon and PKC-zeta are demonstrated immunologically in these cell lines and also in two normal human glial cell cultures. Protein kinase C-delta was not present. When levels of the four isoforms in the tumor cells were compared to levels in the normal cells, no increase was observed in PKC-alpha or PKC-gamma, but PKC-epsilon was elevated three to 30 times in six of the eight tumors, and PKC-zeta was elevated approximately two times in all of the tumors. Incubation of cell line A172 with phorbol ester for 6 hours resulted in a 48-fold maximum increase in the nuclear PKC-epsilon and a sevenfold increase in the plasma membrane fraction with no change in the cytoplasmic fraction. A similar incubation for 4 hours produced a 0.5- to onefold increase of PKC-zeta in cytoplasmic, nuclear, and plasma membrane fractions. Other researchers have shown that overexpression of PKC-epsilon in fibroblasts results in tumorigenesis, and that blocking PKC-zeta function inhibits deoxyribonucleic acid synthesis. These data suggest that alteration in the expression of PKC-epsilon and PKC-zeta could be a factor in the conversion of normal glial cells to glioblastomas.
Cell Line↗