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Biomedical subjects

S Zhao

Publications and source records attributed to S Zhao.

At least 397 records · Page 22Linked to original sources
PubMed1996

Reliability and procedural validity of UM-CIDI DSM-III-R phobic disorders.

We evaluate the long-term test-retest reliability and procedural validity of phobia diagnoses in the UM-CIDI, the version of the Composite International Diagnostic Interview, used in the US National Co-morbidity Survey (NCS) and a number of other ongoing large-scale epidemiological surveys. Test-retest reliabilities of lifetime diagnoses of simple phobia, social phobia, and agoraphobia over a period between 16 and 34 months were K = 0.46, 0.47, and 0.63, respectively. Concordances with the Structured Clinical Interview for DSM-III-R (SCID) were K = 0.45, 0.62, and 0.63, respectively. Diagnostic discrepancies with the SCID were due to the UM-CIDI under-diagnosing. Post hoc analysis demonstrated that modification of UM-CIDI coding rules could dramatically improve cross-sectional procedural validity for both simple phobia (K = 0.57) and social phobia (K = 0.95). Based on these results, it seems likely that future modification of CIDI questions and coding rules could lead to substantial improvements in diagnostic validity.

Adolescent↗
PubMed1996

CD30 ligand is expressed on resting normal and malignant human B lymphocytes.

CD30, a member of the tumour necrosis receptor superfamily, is physiologically expressed on a subpopulation of T helper cells in normal individuals but is also expressed on several malignant and virally transformed cells. Its ligand (CD30L) is a pleiotropic cellular transmembrane protein that can induce cell death in several CD30+ cell lines. CD30L expression has been reported on activated human peripheral blood T lymphocytes and macrophages but not on B cells. Here we show that the CD30L is expressed on resting normal and on malignant B cells in addition to both CD4+ and CD8+ subsets of activated T cells, making it the second tumour necrosis family member, in addition to the CD27 ligand, that can be expressed on both T and B cells. These findings raise the possibility that the CD30L has a role in B-cell/T-cell communication and that B and T cells are likely to be involved in the growth regulation of CD30+ tumours.

B-Lymphocytes↗
PubMed1996

A protein class database organized with ProSite protein groups and PIR superfamilies.

A protein class (ProClass) database is developed as a "value-added" "second-generation" database organized according to family relationships. The database collects non-redundant protein sequence entries from SwissProt and PIR databases, and classifies them in families defined collectively by the ProSite protein groups and PIR superfamilies. The major objectives of the database are to maximize family information retrieval, to provide speedy family identification, and to help organizing existing protein sequence databases. The database has two sub-databases: PCFam (ProClass Family) to define protein families and provide links to ProSite patterns and PIR superfamilies, and PCSeq (ProClass Sequence) to describe sequence entries and provide links to PCFam, SwissProt, PIR, and ProSite databases. The current ProClass release has a total of 85,165 sequence entries, about half of which are classified in 3072 ProClass families; it also contains 10,431 newly established SwissProt-PIR links. The database can help reveal domain structures of related families, define new ProSite and PIR families, and provide family assignments for unclassified sequence entries. New ProSite and PIR family members are readily identified via database cross-reference, including 9437 SwissProt entries and 8522 PIR entries. False negative family members missed by both ProSite and PIR are detected using a neural network family identification system. The newly identified superfamily memberships are being incorporated into the current PIR database releases in a collaborative effort with the PIR. The ProClass database is accessible through anonymous FTP and on-line search on the World Wide Web.

Amino Acid Sequence↗
PubMed1996

Motif identification neural design for rapid and sensitive protein family search.

A new method, the motif identification neural design (MOTIFIND), has been developed for rapid and sensitive protein family identification. The method is an extension of our previous gene classification artificial neural system and employs new designs to enhance the detection of distant relationships. The new designs include an n-gram term weighting algorithm for extracting local motif patterns, an enhanced n-gram method for extracting residues of long-range correlation, and integrated neural networks for combining global and motif sequence information. The system has been tested and compared with several existing methods using three protein families, the cytochrome c, cytochrome b and flavodoxin. Overall it achieves 100% sensitivity and > 99.6% specificity, an accuracy comparable to BLAST, but at a speed of approximately 20 times faster. The system is much more robust than the PROSITE search which is based on simple signature patterns. MOTIFIND also compares favorably with BLIMPS, the Hidden Markov Model and PROFILESEARCH in detecting fragmentary sequences lacking complete motif regions and in detecting distant relationships, especially for members of under-represented subgroups within a family. MOTIFIND may be generally applicable to other proteins and has the potential to become a full-scale database search and sequence analysis tool.

Algorithms↗
PubMed1996

Carboxymethyl-dextran-gadolinium-DTPA as a blood-pool contrast agent for magnetic resonance angiography. Experimental study in rabbits.

RATIONALE AND OBJECTIVES: The authors evaluate the efficiency of various doses of a paramagnetic macromolecular contrast agent, a gadolinium (Gd)-DTPA-dextran conjugate, as a blood-pool contrast media, in a transverse three-dimensional time-of-flight (TOF) magnetic resonance (MR) angiography sequence of the abdominal aorta in rabbits. METHODS: Imaging experiments were performed on a 1.5-T magnet, using a transverse three-dimensional TOF tilted optimized nonsaturating excitation (TONE) sequence. The macromolecular contrast media used was a carboxymethyl-dextran-Gd-DTPA (CMD-Gd-DTPA). Different concentrations of CMD-Gd-DTPA (0.005, 0.01, 0.03, 0.05 mmol Gd/kg) were evaluated. A comparative study using Gd-DOTA (0.01 and 0.1 mmol/kg) was performed. A visual analysis based on the gain in the visualized length of small arteries (renal arteries), and a quantitative analysis based on the percent contrast enhancement of the aorta plotted against distance in the slab from the top edge of the acquisition volume were obtained. RESULTS: A signal-to-noise ratio enhancement of the distal part of the aorta and an improvement in the visualized length of the renal arteries were noted for concentrations of CMD-Gd-DTPA ranging form 0.01 to 0.05 mmol Gd/kg. Venous enhancement was noted for concentrations greater than 0.01 mmol Gd/kg when using CMD-Gd-DTPA or Gd-DOTA. CONCLUSION: Carboxymethyl-dextran-Gd-DTPA reduced, in part, the saturation effect in a three-dimensional transverse TOF TONE MR angiography in rabbits. To prevent venous enhancement, observed with the higher concentrations used in this study, a decrease in the polydispersity of the polymer should be a goal in the future. Rapid extravasation of the low-molecular weight fraction of the polymer could explain the venous enhancement.

Animals↗
PubMed1996

A low molecular weight outer-membrane protein of Escherichia coli O157:H7 associated with adherence to INT407 cells and chicken caeca.

Enterohaemorrhagic Escherichia coli (EHEC) O157:H7 and O26:H11 have been shown to produce a low mol.wt outer-membrane protein (OMP) that is unique to a few serotypes of E. coli. A mutant (A10) of E. coli O157:H7 strain HA1 deficient in the OMP was constructed by TnphoA mutagenesis and assayed for its adherent ability. Adherence of A10 to intestinal epithelial cells (INT407) was significantly less than that of its parent strain (HA1). Adherence of HA1 to INT407 cells was significantly decreased by treatment with a monoclonal antibody (4E8C12) that specifically binds to the OMP. When chickens were infected experimentally with E. coli O157:H7 strains, the average number of cfu of strain A10 recovered from chicken caeca was significantly less than those of strain HA1 and wild-type strain 932 at 14 and 21 days after peroral inoculation. These data suggest that the OMP of EHEC is associated with adherence of E. coli O157:H7 to epithelial cells in vitro and chicken caeca in vivo.

Animals↗
PubMed1996

Monoclonal antibodies specific for rat relaxin. IX. Evidence that endogenous relaxin promotes growth of the vagina during the second half of pregnancy in rats.

It is established that endogenous relaxin promotes the growth and development of the cervix, mammary glands, and nipples in pregnant rats. Additionally, the observation that porcine relaxin promotes growth of the vagina in both nonpregnant and pregnant rats provides indirect evidence that endogenous relaxin may effect growth of the vagina during rat pregnancy. The purpose of this study was to determine whether endogenous relaxin promotes growth of the vagina in pregnant rats. To that end, a monoclonal antibody, specific for rat relaxin, designated MCA1, was used to passively neutralize endogenous relaxin throughout the second half of pregnancy in intact rats. Five milligrams of highly purified MCA1 were injected iv to rats daily from days 12-22 of pregnancy. Controls received either a monoclonal antibody for fluorescein or PBS. The vaginal wet weight, dry weight, length, diameter, inner surface area, DNA content, and percent water content were determined. No differences were found between monoclonal antibody for fluorescein and PBS controls for any of the measured vaginal parameters. In contrast, values for all physical parameters, except percent water content, were significantly lower in MCA1-treated rats than in controls. Vaginal DNA content was also lower in MCA1-treated rats than in controls; and this observation supports the view that relaxin induces vaginal growth at least in part by promoting cell proliferation. To examine the mechanism of relaxin's apparent action on the vagina, specific relaxin-binding sites were localized immunohistochemically. Relaxin-binding sites were found in epithelial and smooth muscle cells, and the binding was specific for relaxin. We conclude that endogenous relaxin promotes growth of the vagina in pregnant rats.

Animals↗
PubMed1996

Semi-automated PCR method for quantitating MDR1 expression.

The MDR1 gene is involved in drug resistance in many hematopoietic and solid tumors. The Quantitative PCR System 5000 (QPCR-5000; Perkin-Elmer) is a new instrument system that uses electrochemiluminescence to automatically quantitate polymerase chain reaction (PCR) products. A comparative study between radioactively labeled PCR (32P-PCR) and QPCR was performed to analyze the MDR1 gene expression in the drug-resistant (Doxorubicin) cell lines Dox40, Dox6, the parental cell line 8226/S, CEM Dox1 and three acute myeloid leukemia (AML) patient samples. Using the Dox40 and Dox6 resistant cell lines, we compared the sensitivities of QPCR and 32P-PCR. A strong signal was obtained from QPCR at 20 to 25 cycles (which is in the linear range for quantitation), while a weak signal was obtained using 32P-PCR at the same cycle number. Dilution experiments gave better precision with the QPCR than with the radioactive method. AML samples were studied with the MDR1-specific MAbs MRK16 and 4E3, and the efflux function was analyzed using Rh-123 retention in the absence or presence of verapamil. The three samples showed high (D = 0.79), medium (D = 0.52) and negative (D = 0.08) p-glycoprotein (P-gp) levels and correlated with efflux function. The MDR1/beta 2-M mRNA ratios for 32P-PCR were 0.41, 0.40 and 0.12, respectively, and were 0.127, 0.097 and 0.028, respectively, for QPCR. There were significant differences between the samples with high and medium P-gp levels comparing the two methods. Very low levels of MDR1 in CEM Dox1 cells could be detected only by QPCR. In conclusion, QPCR was found to be more reproducible, accurate and sensitive than 32P-PCR.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1996

[Sixty years of study on history of special medical disciplines].

By history of special medical disciplines, it refers to history of many subjects in special medicine, basic medicine, clinical medicine, and preventive medicine. Being an important field in the research of medical history, it made its first appearance around 1911. For the period beginning from 1930's-1960's, it passes through 3 stages, viz. the beginning, the flourishing and the profound development. The first period includes the publication of over 400 papers, the 2nd period, over 440 articles, and that in the 3rd period, over 1300 papers. It has been estimated that over one hundred journals and newspapers published articles in this special field.

China↗
PubMed1996

Preliminary study on the molecular structure of 3' region of Duchenne muscular dystrophy (DMD) gene in Chinese.

Number and order of HindIII exon-containing fragments (Hd) at 3' region of DMD gene were studied systematically using 16 partly-overlapping cDNA subprobes which were produced from dystrophin cDNA 9-14 with each of 9 restriction endonucleases. There are 25 Hd fragments corresponding to cDNA 9-14 in DMD gene. Since then, the exact length and the new order of Hd fragments are established. A new 2.1 kb fragment (Hd 55) is revealed; a 5.2 kb fragment (formerly designated as Hd 59) is excluded and the existence of a controversial 3.2 kb fragment (Hd 64) is confirmed. Besides, three new exons were revealed by comparing the PvuII and the XbaI hybridization patterns with the HindIII hybridization patterns for these cDNA subprobes. It is concluded that there are at least 66 Hd fragments, or 79 exons in DMD gene basing on the discovery of three additional exons. The corresponding relationship between the 66 Hd fragments and the SfiI large scale physical map has been studied, and at least 17 Hd fragments or 19 exons were shown to be distributed in the last fragment (IJ fragment) of the SfiI map of DMD gene.

DNA, Complementary↗
PubMed1996

[The establishment of a three dimensional PCR screening system and quality evaluation of human YAC library].

In order to screen out YAC clones in the CEPH YAC library related to a definite gene, DNA fragment or locus, we need to establish a screening system. This paper includes the establishment of this system and the evaluation of its feasibility. According to the experiments, we suggest that it is better to screen the Mega YAC part of the library at first and put five culture plates as a group. Meanwhile, FISH experiments to assess the quality of CEPH YAC library and the first generation physical map of human genome, Were conducted FISH experiments on 26 YAC clones were carried out. There were 13 clones that were chimeric (about 50%), 6 clones that were mapped by mistake (about 23%). So, there were only 9 clones that were mapped correctly and were not chimeric (about 35%).

Chromosomes, Artificial, Yeast↗
PubMed1996

[Effects of capsules on attachment of human periodontal ligament fibroblasts to root surface].

Inhibition of attachment of human periodontal ligament fibroblasts to root surface by three capsules were determined with the methods of trypan blue and L*a*b* color difference measurement. The results showed that capsule from porphyromonas gingivalis was the strongest one in inhibiting attachment and followed by the one from provotalla intermedia. Capsule from porphyromonas endodontolis was the weakest one. The values of color difference from that of control root surface were 11, 13, 8.28 and 4.09 respectively. Inhibitory mechanism of capsules may include a direct growth inhibition of fibroblasts and a decrease in attachment due to changes of root surface properties. There were a few fibroblasts attached to root surface with progressive periodontitis, this was a sharp contrast with that of control root surface. We deduce that long term affections of toxins including capsules and other substances led to changes of root surface with periodontitis, which made fibroblasts difficult to attach.

Bacterial Capsules↗
PubMed1996

239 cases of high fever in viral upper respiratory infection (URI) treated with xiang shi qing jie (XSQJ) bag tea.

XSQJ bag tea was used to treat 239 cases of high fever caused by viral upper respiratory infection, widely spreading in summer and autumn. For comparison, a control group treated by penicillin combined with Ganmao Qingre Chongji or Banlangen Chongji was set up. The results showed the effect of XSQJ bag tea on the time of abating fever, resolving symptoms and physical signs were significantly better than that of the control group.

Adenovirus Infections, Human↗