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Biomedical subjects

B Hu

Publications and source records attributed to B Hu.

At least 199 records · Page 11Linked to original sources
PubMed1997

Immunofluorescence in situ hybridization (IFISH) in neurones retrogradely labelled with rhodamine latex microspheres.

The method of non-radioactive in situ hybridization was developed as an alternative to radioactive assay because of the difficulties and disadvantages of the safety measures required, extensive time required for autoradiography (especially with 3H-labelled probes) and limited cellular resolution obtained using 32P- and 35S-labelled probes. This method holds great potential for studying functional anatomy of specific neuronal pathways if it can be used in conjunction with conventional tract tracing techniques. In this article we describe a simple method by which immunofluorescence in situ hybridization (IFISH) was jointly used with rhodamine latex microspheres (RLM) to trace the origin of the thalamic cholecystokininergic input in rat. RLM is a widely used retrograde fluorescence tracer and seems ideal for IFISH because: (1) it lacks aversive effect on the hybridization and immunocytochemical reactions, (2) it is resistant to the rather harsh tissue treatment required for IFISH, and (3) both the RLM and mRNA hybrids give fluorescence signals; therefore, the extent of signal co-localization can be conveniently and more accurately verified under an epifluorescence microscope. Success of the IFISH-RLM combination is chiefly limited by the quantity and availability of mRNA signals in the tissue. In our case, we used a digoxigenin (DIG)-labelled oligonucleotide probe, which through immunological amplification significantly enhanced the sensitivity of mRNA detection.

Animals↗
PubMed1997

2',3'-Dideoxyinosine-induced Mallory bodies in patients with HIV.

Didanosine (ddI) that inhibits the reverse transcriptase of human immunodeficiency virus (HIV) causes steatosis and fulminant hepatitis in some patients with HIV. We studied hepatic histopathologic changes with particular attention to ddI-induced Mallory body formation. Three liver biopsies were performed on three patients with HIV who were treated with ddI; an autopsy was performed on a patient with HIV who was also treated with ddI. All hepatic specimens were studied with a routine liver immunohistochemical panel including antibodies to ubiquitin and cytokeratin (CAM 5.2). Morphologically, all hepatic specimens showed focal to diffuse steatosis with a predominance of macrovesicular fatty change. Fibrosis was minimal in three cases. No secondary bacterial and fungal infections were noted. Single or clusters of "empty cells" were present, and some contained Mallory bodies validated by ubiquitin stain. Empty cells are hepatocytes that fail to stain positive for cytokeratin. The Mallory bodies were different from the others because they were randomly distributed and occurred in noncirrhotic hepatic tissue. In the autopsy specimen, the Mallory bodies had a centrilobular location with central fibrosis (central sclerosing hyaline necrosis).

Adult↗
PubMed1997

Ig S gamma-specific DNA binding protein SNAP is related to the helix-loop-helix transcription factor E47.

SNAP, a DNA-binding protein, is specific for the S gamma switch regions. Two E-2 box consensus binding motifs are located within the SNAP recognition site. Direct- and competition-binding analyses demonstrate that a truncated form of the E47 transcription factor, E47S, is capable of specific interactions with the SNAP binding motif. The methylation interference pattern for E47S binding on the pl.S gamma 3.A.1 probe was similar to that previously obtained for SNAP binding activity and was also related to that found for E47S on the microE5 probe. The interaction of purified E47S with the SNAP recognition motif was cooperative and formed complexes which migrated more slowly than the E47S homodimer complex. SNAP is distinguished from full-length E47 homodimers, found in BCF-1, by its migration position in the gel shift assay, differences in the competition-binding results and its unique reactivity with anti-E47 antibodies. SNAP is related to E47 as judged by a similar methylation interference pattern on S gamma 3 A site DNA and by its reactivity with anti-E47 mAb. The anti-E47 antibodies block SNAP binding to its cognate site, whereas anti-E47 antibodies supershift E47 homodimers bound to the microE5 recognition site. Thus, SNAP may be a hetero-oligomeric species containing E47 or highly related proteins.

Animals↗
PubMed1997

A communication server for telemedicine applications.

The telemedicine applications, in some cases, need multipoint-to-multipoint communication. To meet the requirement of telemedicine communication, the development of a medical communication server is proposed in this paper. To make a working, as well as cost-effective, communication platform for the telemedicine applications, a specially designed communication server model is proposed in this work. This server is able to provide an effective multipoint-to-multipoint communication service for any level applications in telemedicine. The implementation program of this server is developed in a Windows'95 environment by using a winsocket. The trial application testing in a telemonitoring system is also presented to demonstrate the feasibility of taking such a structure with the server. By using the architecture of such a communication server in telemedicine applications, the multipoint-to-multipoint communication is easily managed and the communication processes are simplified and well controlled by the server.

Blood Pressure Monitoring, Ambulatory↗
PubMed1997

In vivo analysis of DNA-protein interactions on the human erythropoietin enhancer.

The erythropoietin (EPO) gene is one of the best examples of a mammalian gene controlled by oxygen tension. The DNA elements responsible for hypoxia-induced transcription consist of a short region of the proximal promoter and a <50-bp 3' enhancer. The elements act cooperatively to increase the transcriptional initiation rate approximately 100-fold in response to low oxygen tension in Hep3B cells. Two distinct types of transactivating proteins have been demonstrated to bind the response elements in the human EPO enhancer in vitro: one shows hypoxia-inducible DNA binding activity, while the other activity binds DNA under normoxic and hypoxic conditions. We have investigated the DNA-protein interactions on the human EPO enhancer in living tissue culture cells that produce EPO in a regulated fashion (Hep3B) and in cells that do not express EPO under any conditions tested (HeLa). We have identified in vivo DNA-protein interactions on the control elements in the human EPO enhancer by ligation-mediated PCR technology. We show that the putative protein binding sites in the EPO enhancer are occupied in vivo under conditions of normoxia, hypoxia, and cobalt exposure in EPO-producing cells. These sites are not occupied in cells that do not produce EPO. We also provide evidence for a conformational change in the topography of the EPO enhancer in response to hypoxia and cobalt exposure.

Base Sequence↗
PubMed1997

[The evaluation of endoscopic biliary drainage for 288 patients with malignant hilar obstruction].

Hilar tumors are extremely difficult to manage with a considerably lower resection rate. We performed endoscopic biliary drainage for 288 patients with hilar tumors (Klatskin tumor 184, gallbladder carcinoma 23, HCC 47 and other metastases 34) in the past 3 years. 162 patients underwent endoscopic nasobiliary drainage, 80 plastic biliary stenting, and 46 expandable metal stent implantation. 4 patients were given double stents insertion simultaneously, 43.1% of patients received good drainage with the total effective rate of 67.0%, but postprocedure cholangitis took place in 13.8% of patients within one month and 3 died of cholangitis and sepsis. In the long-term follow-up patients without surgical treatment, the median sruvival was 5.3 months. The outcome was closely related to Bismuth types, and jaundice could be relieved if more than about 40% of the liver was drained. The double stents for the left and right intrahepatic duct in the meantime could enlarge drainage area and improve the theraputic effectiveness. To get highest benefit, the 3 endoscopic biliary drainage methods should be choosen properly and exchanged flexibly. We conclude that endoscopic biliary drainage is a safe and useful management for the hilar tumor and should be the treatment of choice for palliating jaundice in the inoperable patients.

Adolescent↗
PubMed1997

[Enzynology of infected part of red skin ginseng].

By means of polyacrylaminde gel eletrothoresis and thin layer scanning, the paper semi-quantitatively studies some relation between component and activity of isoenayme of Ginseng infecting red skin desease. The results show activity of esterase increases 100% than that of normal Ginseng; activity of polyphenol oxidase increases 60-30% and represent new isoenzyme bands in the early infection in juxtapose transolant experiment.

Catechol Oxidase↗
PubMed1997

[Effects of antisense oligodeoxynucleotides targeting multidrug resistance gene on resistant cell line K562/ AO2].

OBJECTIVE: To investigate the reversal effect of antisense oligodeoxynucleotide on human multidrug-resistant leukemic cell line K562/AO2. METHODS: Antisense oligodeoxynucleotides (AOD) targeting-6 approximately 9 sites of exon 2 in human multidrug resistance gene(mdr-1), one of which is sequence-strict-complied and linked with polyethyleneglycol (PEG) at 5' end (AP, 15 mer), the other lacks nucleotide complied site-1 (AP', 14mer), were synthesized. AP, AP' and verapamil were simultaneously added to human mdr-1-mRNA positive leukemia cell line K562/AO2 and, mdr-1-mRNA and p170 were detected. AS' and AP'were labelled by FITC and designated as ASF' and APF', respectively. In addition, the intracellular concentration of them was detected by FACS. RESULTS: AP' significantly enhanced the sensitivity of K562/AO2 to DOX, down-regulated the expression of mdr-1 and MRP-mRNA and p170, elevated the intracellular concentration of the two AOD, while AP had no effect. The uptake of APF' was significantly higher than that of ASF' in K562/AO2, and the fluorescence was observed in the plasma and nuclear of K562/AO2 cells. CONCLUSION: (AOD targeting mdr-1 promoted the drug sensitivity of drug-resistant tumor cells. 2 AOD had no cytotoxicity to tumor cells. 5 Low molecule PEG enhanced significantly the uptake of AOD by tumor cells.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1997

The construction and expression of deletion mutant of human pro-urokinase cDNA.

The human pro-urokinase mutant deleting 150-156 amino acids was constructed by overlap-extension PCR and other molecular cloning techniques. The mutant was expressed transiently in COS-7 cells and constitutively in CHO cells; the expression level is 450-500 IU/10(6) cells/24 h. SDS-PAGE and Western blotting analysis showed that the molecular weight of the expression product is 54 kDa, which is similar to that of the mature pro-UK and recombinant pro-UK (rPro-UK) expressed by full-length cDNA. Most of the products exist in the form of single chain; the percentage of single chain is much higher than that of rPro-UK. In addition, the mutant product is more resistant to proteinases and its affinity to fibrin is also improved slightly.

Animals↗
PubMed1997

[Ageing changes of the cardiac conduct system].

This paper reviews the ageing changes of the human cardiac conduction system according to the ever published literature. In ageing process, the cardiac conduction system shows typical physiological changes: (1) differentiation, development and maturation in fetal and postnatal period, (2) reduction of the specific conduction cells and the changes of the whole node volumes. (3) fibrosis and fat infiltration. It is stressed that while explaining the causes of sudden death with the knowledge of cardiac conduction system diseases, the forensic pathologist should be able to distinguish the pathological changes from that of the normal ageing.

Age Factors↗
PubMed1996

Isolation and sequence of a novel human chondrocyte protein related to mammalian members of the chitinase protein family.

We describe the isolation of a novel protein from the conditioned medium of human articular cartilage chondrocytes in primary culture. This 39-kDa protein has the N-terminal sequence YKL, which we have termed YKL-39. The 1434-nucleotide sequence of the YKL-39 cDNA predicts a 385-residue initial translation product and a 364-residue mature YKL-39. The amino acid sequence of YKL-39 is most closely related to YKL-40, followed by macrophage chitotriosidase, oviductal glycoprotein, and macrophage YM-1. All five proteins share significant sequence identity with bacterial chitinases and have the probable structure of an (alphabeta)8 barrel. YKL-39 lacks the active site glutamate, which is essential for the activity of chitinases, and as expected has no chitinase activity. The highest level of YKL-39 mRNA expression is seen in chondrocytes, followed by synoviocytes, lung, and heart. YKL-39 accounts for 4% of the protein in chondrocyte-conditioned medium, prostromelysin accounts for 17%, and YKL-40 accounts for 33%. In contrast to YKL-40, YKL-39 is not a glycoprotein and does not bind to heparin.

Adipokines↗
PubMed1996

Peptides corresponding to CD4-interacting regions of murine MHC class II molecules modulate immune responses of CD4+ T lymphocytes in vitro and in vivo.

Immune responses mediated by CD4+ T cells depend on Ag-specific alpha beta TCRs that recognize the specific antigenic peptide presented by MHC class II molecules. Interactions between CD4 coreceptors and monomorphic regions of MHC class II molecules contribute to these responses. To examine whether immune reactions could be modulated by specifically interfering with CD4-MHC class II interactions, we have used, in various in vitro and in vivo assays, peptides that correspond to a region of MHC class II molecules previously shown to control interaction with CD4. Depending on the chemical nature and concentration of these peptides, they modulated Ag-specific responses of CD4+ T cells. At high concentrations, these peptides inhibited T cell responses in vitro. However, under conditions that can cause Ag-induced unresponsiveness, the peptides enhanced T cell responses. Also, primary in vivo immune responses to systemically administered soluble protein Ag, keyhole limpet hemocyanin, were enhanced when mice were treated with peptides corresponding to the CD4-interacting region of MHC class II molecules but not when treated with control peptides. Lymphokine profiles suggested that the peptides may favor the differentiation of Th1 cells, because lymphocytes from peptide-treated mice secreted more IL-2 and IFN-gamma than lymphocytes from nontreated or control-peptide-treated mice upon restimulation with Ag in vitro. These results demonstrate that MHC class II-derived peptides can directly interfere with interactions with CD4 and modulate T cell responses in vitro and in vivo.

Adjuvants, Immunologic↗
PubMed1996

Occipital encephalocele and MURCS association: case report and review of central nervous system anomalies in MURCS patients.

The combination of MURCS association (Müllerian duct and renal agenesis, upper limb and rib anomalies) and occipital encephalocele occurred in a stillborn girl of 41 weeks gestation. The malformations are compatible with a defect in the organization of the paraxial mesoderm that gives rise to occipital, cervical, and thoracic somites and adjoining intermediate mesoderm. These structures contribute to the occipital bone, cervical spine, upper limbs, and urogenital system. Brain imaging may be useful in assessing MURCS patients, if cranial malformations prove to be clinically important in these individuals.

Abnormalities, Multiple↗
PubMed1996

Virus-like particles as a rotavirus subunit vaccine.

Rotavirus subunit vaccines are being evaluated for use in humans. The virus-like particles (VLPs) for these vaccines are produced in insect cells coinfected with combinations of baculovirus recombinants expressing bovine RIF VP2 and simian SA11, VP4, VP6, or VP7 rotavirus proteins. VLPs were administered parenterally to mice and rabbits, and the immunogenicity and protective efficacy of the vaccines were evaluated. Rabbits vaccinated with VP2/4/6/7 or VP2/6/7 VLP combinations developed high levels of rotavirus-specific serum antibody and fecal IgG but not fecal IgA. The induction of fecal IgG was associated with total or partial protection from oral challenge with ALA rotavirus. Heterotypic serum and fecal neutralizing antibody was induced in mice vaccinated parenterally with G1 VP2/6/7 or VP2/4/6n VLPs. VLPs were highly immunogenic when administered in QS21 adjuvant, inducing serum neutralizing antibody titers comparable to those induced by SA11 virus. VLPs are effective immunogens when administered parenterally and may be an effective subunit vaccine.

Animals↗
PubMed1996

Intracellular expression of single-chain variable fragments to inhibit early stages of the viral life cycle by targeting human immunodeficiency virus type 1 integrase.

Integration of viral DNA into a chromosome of the infected host cell is required for efficient replication of a retroviral genome, and this reaction is mediated by the virus-encoded enzyme integrase (IN). As IN plays a pivotal role in establishing infection during the early stages of the retroviral life cycle, it is an attractive target for therapeutic intervention. However, the lack of effective antiviral drug therapy against this enzyme has led to the testing of other novel approaches towards its inhibition. In these studies, a panel of anti-human immunodeficiency virus type 1 (anti-HIV-1) IN hybridomas has been used in the construction of single-chain variable antibody fragments (SFvs). The monoclonal antibodies produced by these hybridomas, and derived SFvs, bind to different domains within IN. We now demonstrate that intracellular expression of SFvs which bind to IN catalytic and carboxy-terminal domains results in resistance to productive HIV-1 infection. This inhibition of HIV-1 replication is observed with SFvs localized in either the cytoplasmic or nuclear compartment of the cell. The expression of anti-IN SFvs in human T-lymphocytic cells and peripheral blood mononuclear cells appears to specifically neutralize IN activity prior to integration and, thus, has an effect on the integration process itself. These data support our previous studies with an anti-HIV-1 reverse transcriptase SFv and demonstrate further that intracellularly expressed SFvs can gain access to viral proteins of the HIV-1 preintegration complex. This panel of anti-HIV-1 IN SFvs also provides the tools with which to dissect the molecular mechanism(s) directly involved in integration within HIV-1-infected cells.

Amino Acid Sequence↗