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B Wang

Publications and source records attributed to B Wang.

At least 793 records · Page 44Linked to original sources
PubMed1994

[A primary clinical trial of genital warts treated with domestic highly purified podophyllotoxin].

Genital warts (condyloma accunimata) are a kind of sexually transmitted disease (STD) caused by human papillomavirus (HPV). In this article, we report 75 cases of genital warts treated with highly purified podophyllotoxin. All volunteers were selected in our clinic and diagnosed according to typical skin lesions and positive 0.5% acetic acid test. Of the 74 cases 48 were male and 26 were female, with a mean age of 28.4 years (21-54). The average duration of disease was 4.4 months (2 weeks-3 years). All lesions were treated with 0.5% podophyllotoxin-ethanal solution topically 2 times per day for 3 successive days. The treatment was repeated if any warts persisted, but not more than 3 therapies in total were applied. The results showed that 41/48 (85.4%) of male and 23/26 (88.5%) of female patients were cured, the overall cure rate was 86.5% and the effectiveness rate (more than 50% lesions disappeared) was 96.15%. During another 3 months of follow-up, 9 male and 4 female patients (17.6% in total) experienced relapsed warts; these were cured with another treatment. Side effects including slight local irritation and erythema or superficial erosions were common, but 3 male and 2 female patients complained of sever pain and local swelling. All side effects were tolerable. It is concluded that our domestically produced highly purified podophyllotoxin is an effective, comparatively safe drug for the treatment of genital warts. It is also very simple to apply, and can be used for self-treatment.

Adult↗
PubMed1994

[Application of nitrous oxide in labor analgesia].

Labor analgesia with nitrous oxide was studied in 34 parturients, and another 50 women taking no drug as the control group. The analgesic effect was satisfactory. By Mulleetr's pain in labor score, 91.18% women had score of 0-1, and their respiratory and circulatory functions were not affected. During inhalational analgesia the parturients remained conscious. Uterine contraction, progress of labor and neonatal Apgar score were not interferred, and postpartum bleeding was not increased. There was no complications in the treatment group. This study suggests that nitrous oxide with enough oxygen inhalation is one of the good drug for obstetric analgesia, but its concentration must be strictly controlled.

Adult↗
PubMed1994

[Cloning and DNA sequencing of the gene encoding trichosanthin].

A gene encoding Trichosanthin (TCS) was amplified by means of DNA polymerase chain reaction (PCR) and cloned from the genomic DNA of Trichosanthes kirilowii. Its DNA sequence has been determined. Nucleotide sequence analysis indicates that the cloned TCS gene includes 5'-flanking region and the encoding sequence for TCS preproprotein. Comparison of its encoding sequence with the published nucleotide sequences of three TCS genes demonstrates that they have the sequence homologies of 99.20%, 98.74% and 98.64% respectively. Comparing its deduced amino acid sequence with four reported amino acid sequences of TCS demonstrates that they have the sequence homologies of 98.62%, 97.62%, 97.41% and 98.38% respectively. A new TATA-like box sequence was found in the 5'-flanking region of cloned TCS gene. In order to further study the structure, expression, regulating mechanism of TCS gene and the structure-functional relationship of TCS, a series of mutants of TCS gene has been constructed. The expression of these mutants in bacteria and transgenic plant has being studied.

Amino Acid Sequence↗
PubMed1994

[Establishment and characterization of a SV40 transformed human fetal gastric epithelial cell line-GES-1].

9 month human fetal gastric epithelial cells were primarily cultured and infected with SV40 virus. About 3 weeks after infection the transformed-like cells showed up and were isolated when most of the normal cells senesced. One transformed clone named GES-1 were analyzed biologically. The results indicated integration of the SV40 T gene and its expression in the cell nuclei and the cells became hyperploid in chromosomes. This cells also maintained a normal cytoskeleton, positive in PAS reaction and were non-tumorigenic in nude mice. The established cell line may be served as an important model system in study of human gastric carcinogenesis.

Animals↗
PubMed1994

A comparison of the binding and functional properties of alpha-1 adrenoceptors and area density of smooth muscle in the human, canine and rat prostates.

The present study was designed to compare the binding and functional properties of alpha-1 adrenoceptors and the area density of smooth muscle in the human, canine and rat prostates. Chloroethylclonidine (CEC)-sensitive and -insensitive alpha-1 adrenoceptors were characterized on slide-mounted prostatic tissue sections using the ligand [3H]prazosin. The mean equilibrium dissociation constants (Kd) for [3H]prazosin binding sites were not significantly different among the three different species. The densities (Bmax) of CEC insensitive [3H]prazosin binding sites in the human, canine and rat prostates were 1.71 +/- 0.32, 0.35 +/- 0.04 and 0.84 +/- 0.11 fmol/mg of wet weight, respectively. The Bmax of CEC-sensitive [3H]prazosin binding sites in the human, canine and rat prostates were 1.32 +/- 0.83, 0.44 +/- 0.11 and 0.25 +/- 0.10 fmol/mg of wet weight, respectively. The contractile response elicited by the rat prostate in the presence of phenylephrine was consistently negligible. The mean maximal force after phenylephrine challenge (phenylephrine Emax) in the human and canine prostates were 0.125 +/- 0.025 g of force/mm2 cross-sectional area and 0.096 +/- 0.014 g of force/mm2 cross-sectional area, respectively. CEC inactivated 80 and 53% of the phenylephrine contractile response in man and dog, respectively. The mean percentage of area densities of smooth muscle in the human, canine and rat prostates were 38.8, 12.9 and < 1%, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Binding and functional properties of endothelin receptor subtypes in the human prostate.

The objective of the present study was to characterize the binding and functional properties of endothelin (ET) receptor subtypes in the human prostate. Human prostatic tissue was obtained from male subjects undergoing radical prostatectomy for low-volume prostate cancer. The optimal assay conditions for characterizing human prostatic ET-1 binding sites on slide-mounted tissue sections were defined. Maximal specific 125I-ET-1 binding was achieved after a 10-min preincubation, a 120-min incubation, and a washing procedure that consisted of a brief rinse and a 1-min wash. The mean equilibrium dissociation constant (Kd) and density (Bmax) of ET-1 binding sites determined from six saturation studies were 0.72 +/- 0.13 nM and 40.4 +/- 6.9 fmol/mg of wet weight, respectively. The mean Hill coefficient was 0.99 +/- 0.01, indicating that 125I-ET-1 identifies a single population of binding sites. The pharmacology of 125I-ET-1 binding sites was characterized using competitive binding experiments. The competition plots for ET-1 were best fit by a one-binding site model, whereas the plots for sarafotoxin 6C (S6C) and BQ123 were consistently best fit by a two-site model. The mean Ki value of ET-1 was 0.34 +/- 0.12 nM. The mean Ki values for the high and low affinity S6C binding sites were 0.50 +/- 0.09 nM and 0.84 +/- 0.28 microM, respectively. The mean Ki values for the high and low affinity BQ123 binding sites were 5.51 +/- 1.05 nM and 24.9 +/- 6.5 microM, respectively. The ratio of ETA to ETB binding sites was approximately 2:1. The ET receptor subtype mediating prostatic smooth muscle tension was investigated using agonist-antagonist competition studies. ET-1, a nonselective ET agonist, elicited a potent contraction of prostate smooth muscle. The pA2 of BQ123 for inhibiting ET-1-mediated contraction was 6.84. S6C, a selective ETB agonist, also elicited a potent contraction of prostate smooth muscle. BQ123 at concentractions between 0.1 and 10 microM did not shift the S6C dose-response curve. These functional studies suggest that both ETA and ETB receptors mediate the tension of prostate smooth muscle. Endogenous ETS may be involved in the pathophysiology of bladder outlet obstruction in men with benign prostatic hyperplasia. If this is the case, then ET antagonists may represent effective treatment for benign prostatic hyperplasia.

Binding, Competitive↗
PubMed1993

Following a diabetogenic T cell from genesis through pathogenesis.

Nonobese diabetic (NOD) mice spontaneously develop a disease very similar to type 1 diabetes in humans. We have generated a transgenic mouse strain carrying the rearranged T cell receptor genes from a diabetogenic T cell clone derived from a NOD mouse. Self-reactive T cells expressing the transgene-encoded specificity are not tolerized in these animals, resulting in rampant insulitis and eventually diabetes. Features of the disease process emphasize two so-called check-points, recognized previously in the NOD and human diseases but easily misinterpreted. Although NOD mice are protected from insulitis and diabetes by expression of the E molecule encoded in the major histocompatibility complex, the transgenics are not, permitting us to exclude some possible mechanisms of protection.

Amino Acid Sequence↗
PubMed1993

Structure of the product from a novel cyclization reaction involving a C(6)-substituted uridine analog.

5,6,7,7a,9,10,14b,14c-Octahydro-4-[2,3-O-(1-methylethylidene )-beta-D- ribofuranosyl]cyclopenta-[4,5]pyrimido[5',4':3,4]pyrrolo[2,1- a]isoquinoline-1,3(2H,4H)-dione, C25H31N3O6, M(r) = 469.54, tetragonal, P4(3)2(1)2, a = 12.577 (2), b = 12.577 (2), c = 29.893 (4) A, V = 4729 (1) A3, Z = 8, Dx = 1.319 g cm-3, lambda (Cu K alpha) = 1.5418 A, mu = 7.9 cm-1, F(000) = 2000, T = 298 K, final R = 0.038, wR = 0.064 for all 1884 independent reflections and 432 variables. The crystal structure shows a syn conformation around the N(1)--C(1') single bond, consistent with other C(6)-substituted uridine analogs, and an unusual O(1') endo conformation of the ribose ring. The stereochemistries of the three newly created chiral centers are 14cR, 4aR, 7aS.

Crystallography, X-Ray↗
PubMed1993

Preparation and characterization of a bifunctionally spin-labeled mutant of murine epidermal growth factor for saturation-transfer electron paramagnetic resonance studies of the growth factor/receptor complex.

In this report we describe the production of a [Lys3,Tyr22] murine epidermal growth factor (mEGF) mutant for spin-labeling with bis(sulfo-N-succinimidyl)-[15N,2H16]doxyl-2-spiro-4'-pimelate ([15N,2H16]BSSDP) in order to study the rotational dynamics of the EGF/EGF receptor complex by saturation-transfer electron paramagnetic resonance (ST-EPR). Previous results [Faulkner-O'Brien et al. (1991) Biochemistry 30,8976-8985] indicated that the reaction of [15N,2H16]BSSDP with wild-type mEGF did not yield a product useful for ST-EPR studies of the EGF/EGF receptor complex because the major product, in which [15N,2H16]BSSDP was attached only at the amino terminus of mEGF, lacked rigid motional coupling of the spin probe to the protein, and the more tightly coupled bidentate product was unstable. Using oligonucleotide-mediated site-directed mutagenesis of a synthetic gene for mEGF, we replaced Tyr3 with Lys and His22 with Tyr in wild-type mEGF to produce a mutant mEGF suitable for [15N,2H16]BSSDP labeling. The [Lys3,Tyr22] mEGF was expressed in Escherichia coli HB101 transformed with a pIN-III-ompA3-[Lys3,Tyr22] mEGF plasmid and was purified from the bacterial periplasm using a simple two step purification method. The [15N,2H16]BSSDP reacted with [Lys3,Tyr22]mEGF in high yield, and EPR analysis of the major product revealed tight motional coupling between the spin probe and the protein. Biological activity, as assessed by stimulation of EGF receptor autophosphorylation and dimerization, was not affected by either the mutations or the addition of the spin label. The [15N,2H16]BSSDP-modified [Lys3,Tyr22] mEGF was shown to be equipotent with mEGF in EGF receptor competition binding assays using A431 cells; in EPR studies, mEGF also was shown to specifically block [15N,2H16]BSSDP-modified [Lys3,Tyr22]mEGF binding to the EGF receptor in A431 membrane vesicles. Using the [15N,2H16]BSSDP-modified [Lys3,Tyr22]mEGF, we now report the first measurement of the rotational dynamics of the EGF/EGF receptor complex in A431 membrane vesicles by ST-EPR.

Amino Acid Sequence↗
PubMed1993

Localization of an immunologically functional region of the streptococcal superantigen pepsin-extracted fragment of type 5 M protein.

Ten overlapping synthetic peptides, spanning the entire amino acid sequence of pepsin-extracted type 5 M protein, (pep M5), were used to delineate regions within this molecule that are important for the mitogenic activity of this streptococcal superantigen. Two of the overlapping peptides, SM5-8 and SM5-10, blocked the response of T cells to pep M5 in a dose-dependent manner. Neither peptide was toxic to T cells, but SM5-8 exhibited nonspecific inhibition of the T-cell response to either superantigen or polyclonal mitogens. In contrast, the inhibition by SM5-10 was pep M5-specific. Analysis of TCR V beta gene usage of the pep M5 response in the presence and absence of SM5-10 revealed that this peptide preferentially blocks the expansion of pep M5-specific V beta elements. The degree of inhibition of V beta expansion varied from one individual to the other, reflecting their TCR repertoire. SM5-10 did not significantly inhibit the response of T cells to other streptococcal superantigens. The data suggest that the region represented by SM5-10 of the pep M5 is important for superantigenic activity. In addition, the ability of this synthetic peptide to inhibit the response to pep M5 provides evidence that the mitogenic response is indeed mediated by this superantigen and is not a result of contamination with other streptococcal superantigens.

Amino Acid Sequence↗
PubMed1993

Increased expression of specific protein tyrosine phosphatases in human breast epithelial cells neoplastically transformed by the neu oncogene.

Protein tyrosine phosphorylation/dephosphorylation is a fundamental mechanism in the regulation of cell proliferation and neoplastic transformation; this metabolic process is modulated by the opposing activities of protein tyrosine kinases and protein tyrosine phosphatases (PTPases). While the role of protein tyrosine kinases has been examined extensively in human breast tumorigenesis, the role of PTPases in this process is virtually unknown. To address this issue, an activated neu oncogene was introduced into an immortalized nontumorigenic human breast epithelial cell line (184B5). This resulted in a substantial increase in P185neu expression, which led to the formation of progressively growing carcinomas after such cells were inoculated into athymic nude mice. Importantly, a striking increase in the expression of specific PTPases, LAR and PTP1B, was observed in 3 independently neu transformed cell lines and their derived tumors. This elevation was verified at both the mRNA and protein levels. TC-PTP PTPase expression was only slightly increased in these neu transformed cells, and no expression of CD45 PTPase was observed. The level of neu expression, as well as the differential expression between P185neu and LAR/PTP1B, directly correlated with tumorigenicity. Furthermore, rat mammary carcinomas with elevated neu expression (neu-induced) also had sharply elevated LAR-PTPase expression when compared to rat mammary carcinomas with little or no neu expression (7,12-dimethylbenzanthracene induced); the level of expression of LAR PTPase was directly correlated with the level of neu expression. Thus, our results provide the first evidence that, in human breast carcinoma cells and in rat mammary carcinomas that have an induced increase in neu expression, a consistent and substantial increase in the expression of specific PTPases occurs. The relationship between P185neu-protein tyrosine kinase expression and specific PTPase expression may play a critical role in human breast tumorigenesis.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1993

Gene inoculation generates immune responses against human immunodeficiency virus type 1.

Recently, immunization techniques in which DNA constructs are introduced directly into mammalian tissue in vivo have been developed. In theory, gene inoculation should result in the production of antigenic proteins in a natural form in the immunized host. Here we present the use of such a technique for the inoculation of mice with a human immunodeficiency virus type 1 (HIV-1) envelope DNA construct (pM160). Mice were injected intramuscularly with pM160 and were subsequently analyzed for their anti-HIV envelope immune responses. Antisera collected from inoculated animals reacted with the recombinant HIV-1 envelope in ELISA and immunoprecipitation assays. The antisera also contained antibodies that were able to neutralize HIV-1 infection and inhibit HIV-1-mediated syncytium formation in vitro. Furthermore, splenic lymphocytes derived from pM160-inoculated animals demonstrated HIV-envelope-specific proliferative responses. The gene inoculation technique mimics features of vaccination with live attenuated viruses and, therefore, may ultimately prove useful in the rapid development of safe and efficacious vaccines as it provides for production of relevant antigen in vivo without the use of infectious agents.

Amino Acid Sequence↗
PubMed1993

Structural and functional domains of Escherichia coli ribosomal protein L7/L12. The hinge region is required for activity.

Variant forms of Escherichia coli ribosomal protein L7/L12 were constructed, overexpressed, and purified. These included proteins that deleted residues 35-52 (delta 35-52) and 42 to 52 (delta 42-52), others that contained single cysteine substitutions at residues 63 and 89, and combinations of the deletions and cysteine substitutions. Chemical modification of the introduced cysteine residues with [14C]iodoacetamide was used to radiolabel the protein variants in order to quantify their binding to the ribosome. Neither of the deletions in the hinge domain, delta 35-52 and delta 42-52, had any effect on L7/L12 dimer formation as detected by cross-linking by dimethyl suberimidate. Perpendicular urea gradient gel electrophoresis showed that both deletion variants retained a compact structural element attributable to the globular C-terminal domain. Reconstitution of core particles depleted of wild type L7/L12 with the deletion proteins showed that delta 42-52 bound normally in 4 copies per particle, whereas delta 35-52 bound in only 2.5 copies following isolation of the particles by high speed centrifugation or gel filtration. Ribosomes mixed with an excess of the deletion variants and assayed directly for polyphenylalanine synthesis were completely inactive. The results suggest that the flexibility conferred by the hinge is required for activity, perhaps by allowing the C-terminal domain to occupy a location near the base of the L7/L12 stalk.

Amino Acid Sequence↗
PubMed1993

Abnormal T cell development in CD3-zeta-/- mutant mice and identification of a novel T cell population in the intestine.

The T cell antigen receptor (TCR)-associated invariable membrane proteins (CD3-gamma, -delta, -epsilon and -zeta) are critical to the assembly and cell surface expression of the TCR/CD3 complex and to signal transduction upon engagement of TCR with antigen. Disruption of the CD3-zeta gene by homologous recombination resulted in a structurally abnormal thymus which primarily contained CD4- CD8- and TCR/CD3very lowCD4+CD8+ cells. Spleen and lymph nodes of CD3-zeta-/- mutant mice contained a normal number and ratio of CD4+ and CD8+ single positive cells that were TCR/CD3very low. These splenocytes did not respond to antibody cross-linking or mitogenic triggering. The V beta genes of CD4-CD8- and CD4+CD8+ thymocytes and splenic T cells were productively rearranged. These data demonstrated that (i) in the absence of the CD3-zeta chain, the CD4- CD8- thymocytes could differentiate to CD4+CD8+ TCR/CD3very low thymocytes, (ii) that thymic selection might have occurred, (iii) but that the transition to CD4+CD8- and CD4-CD8+ cells took place at a very low rate. Most strikingly, intraepithelial lymphocytes (IELs) isolated from the small intestine or the colon expressed normal levels of TCR/CD3 complexes on their surface which contained Fc epsilon RI gamma homodimers. In contrast to CD3-zeta containing IELs, these cells failed to proliferate after triggering with antibody cross-linking or mitogen. In comparison to thymus-derived peripheral T cells in the spleen and lymph nodes, the preferential expression of normal levels of TCR/CD3 in intestinal IELs suggested they mature via an independent extrathymic pathway.

Animals↗
PubMed1993

Transcervical CVS sample size: correlation with placental location, cytogenetic findings, and pregnancy outcome.

Data from 2907 transcervical CVS cases performed on singleton pregnancies were reviewed retrospectively and villus sample size was correlated with cytogenetic results, placental location, maternal age at the expected date of confinement (EDC), gestational age at the time of sampling, birth weight, gestational age at the time of delivery, and pregnancy outcome. No correlation was noted between villus sample size and maternal age, gestational age at sampling, gestational age at delivery, birth weight, or pregnancy outcome. An inverse correlation between villus sample size and percentage of abnormal cytogenetic findings was statistically significant (chi 2 = 8.53, p < 0.01). The percentage of small samples was greater when the placenta was anterior, lateral, or fundal than when the placenta was posterior.

Adult↗
PubMed1993

High-level production of the mouse epidermal growth factor in a Bacillus brevis expression system.

In order to determine the three-dimensional structure, the folding pathways, and the residues which are critical for biological functions of the mouse epidermal growth factor (mEGF), large amounts of wild-type and site-specific mutants are needed for biological and physiochemical studies. Genes coding for mEGF and its mutants were expressed in a Bacillus brevis system in which the expressed foreign proteins were secreted into the culture medium. However, proteases were also secreted that resulted in partial degradation of the desired foreign proteins. One mutant with much less protease secretion was isolated by applying nitrosoguanidine mutagenesis on a B. brevis strain. A new vector to facilitate DNA mutagenesis and sequencing was also constructed for this system. Methodologies for the transformation of B. brevis and the purification of expressed mEGF were developed. Under the optimized conditions, the production of the mEGF and its mutants was about 50 mg per liter, and yielded up to 10 mg of purified mEGF. Several mEGF mutants have been produced and their receptor binding abilities have been measured.

Amino Acid Sequence↗