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P Wu

Publications and source records attributed to P Wu.

At least 145 records · Page 8Linked to original sources
PubMed1998

Promoter-associated displacement of hypermutations.

The distribution of somatic hypermutations around the rearranged V(D)J in antigen-selected B cells is asymmetrical. At the 5' end of the gene a high frequency of mutations does not occur until approximately 200 bp downstream of the V gene promoter in the leader intron. This finding seems inconsistent with recently proposed, transcription-coupled models of hypermutation. Here we describe studies on extensively mutated copies of a kappa light chain transgene which appear to exist as passenger genes for a significant portion of their mutational history. These transgenes contain between one and four in-frame stop codons, and have a ratio of replacement to silent mutations in framework regions that is near random; the ratio in their functional counterparts is clearly non-random. When non-functional passenger and functional transgenes are compared, the patterns of mutation in the leader intron are not significantly different; the frequency 3' is greater in the passenger transgenes. This result indicates that the low level mutational activity immediately 3' of the promoter followed by rapid rise in activity is an intrinsic feature of the mutational process. One inference from this finding is that there is a structural feature in V region DNA or one induced during transcription which is critical to a functioning mutator.

Animals↗
PubMed1998

Longitudinal investigation of bacterium-specific synovial lymphocyte proliferation in reactive arthritis and lyme arthritis.

BACKGROUND: Antigen-specific lymphocyte proliferation of synovial fluid mononuclear cells (SF MNC) has been reported repeatedly in reactive arthritis and Lyme arthritis; however, less information is available on serial investigations of SF MNC in the same patients. METHODS: In this study, the synovial lymphocyte proliferation to Yersinia, Chlamydia, Shigella and Borrelia burgdorferi was investigated sequentially at different time points in 28 patients with reactive arthritis, undifferentiated oligoarthritis or Lyme arthritis responding to one of these bacteria. RESULTS: The same bacterium was always recognized in arthritis triggered by Chlamydia, Shigella or Borrelia, with much variation in the proliferative response. Only the Yersinia-specific responses changed specificity, suggesting that the proliferative response to Yersinia is non-specific in some patients. CONCLUSIONS: Our data support the concept of a local antigen-specific T-cell response in reactive arthritis or Lyme arthritis but not the concept suggested by others that a switch to an autoimmune response takes place in long-standing disease.

Antigens, Bacterial↗
PubMed1998

The clinical importance of free prostate-specific antigen (PSA).

The proportion of free prostate-specific antigen (PSA) in serum relative to total PSA (F/T) is lower in patients with prostate cancer than in those with elevated levels of PSA due to benign prostatic disease. When applied to early diagnosis and screening for prostate cancer, the proportion of free PSA can be used to reduce the number of false-positive results by 20-40%. The utility of F/T is better in men with a small prostate volume, i.e. in relatively young men, who are most likely to benefit from early diagnosis and treatment of prostate cancer. The concentrations of PSA and especially free PSA are affected by considerable intra-individual variation and sample stability. Assay standardization is variable and it is therefore important to establish reference values for the methods used. Better control of these factors is likely to improve the diagnostic accuracy. The utility of determining free PSA can be improved by evaluating the combined impact of free and total PSA by logistic regression analysis or neural networks.

Journal Article↗
PubMed1998

Adeno-associated virus vector-mediated transgene integration into neurons and other nondividing cell targets.

The site-specific integration of wild-type adeno-associated virus (wtAAV) into the human genome is a very attractive feature for the development of AAV-based gene therapy vectors. However, knowledge about integration of wtAAV, as well as currently configured recombinant AAV (rAAV) vectors, is limited. By using a modified Alu-PCR technique to amplify and sequence the vector-cellular junctions, we provide the first direct evidence both in vitro and in vivo of rAAV-mediated transgene integration in several types of nondividing cells, including neurons. This novel technique will be highly useful for further delineating the mechanisms underlying AAV-mediated integration, including issues of frequency, site preference, and DNA rearrangement in human as well as animal cells. Results from these studies should be beneficial for the development of the next generation of gene delivery vectors.

Animals↗
PubMed1998

Aldosterone overproduction and CYP11B2 mRNA overexpression in vessels of spontaneously hypertensive rats.

Aldosterone is synthesized in extra-adrenal tissues such as blood vessels and brain. Damage to blood vessels could play a crucial role in perpetuating hypertension. In this study, we determined both aldosterone production and aldosterone synthase gene-CYP11B2 mRNA expression in vessels of spontaneously hypertensive rats (SHR). The results showed that aldosterone was overproduced in the vasculature of SHR, by means of ex vivo mesenteric artery perfusion, HPLC, and RIA, and that CYP11B2 mRNA expression was upregulated in aortas of SHR, confirmed by RT-PCR and Southern blot.

Aldosterone↗
PubMed1998

Increase of vitamin E content in LDL and reduction of atherosclerosis in cholesterol-fed rabbits by a water-soluble antioxidant-rich fraction of Salvia miltiorrhiza.

Antioxidants that prevent LDL from oxidation may reduce atherosclerosis. Salvia miltiorrhiza Bunge is a Chinese herb widely used for the treatment of atherosclerosis-related disorders. Salvianolic acid B (Sal B), a water-soluble polyphenolic antioxidant isolated from the roots of this plant, was found to scavenge 1,1-diphenyl-2-picrylhydrazyl radicals and inhibit LDL oxidation more effectively than probucol. In order to evaluate the antiatherogenic potential, New Zealand White rabbits were fed for 12 weeks a normal diet, a high cholesterol diet, a high cholesterol diet containing 1% probucol, or a high cholesterol diet containing a 5% water-soluble extract of S miltiorrhiza (SM). Both SM and probucol feeding reduced plasma cholesterol. LDLs from the SM-treated group were more resistant to Cu2+-induced oxidation and contained more vitamin E (21.7+/-2.1 mmol/micromol LDL cholesterol) than did LDLs from the high cholesterol diet group (9.6+/-1.8 nmnol/micromol LDL cholesterol) (P<.005). Endothelial damage, determined at week 6, was reduced by 53% in the SM group (P<.01). SM treatment reduced the atherosclerotic area in the abdominal aorta by 56% (P<.005) and cholesterol deposition in the thoracic aorta by 50% (P<.005). The severity of atherosclerosis in the SM group was significantly reduced after adjustment by using cholesterol exposure as an index of the cholesterol-lowering effect. This study concludes that the reduction of atherosclerosis by SM relies not only on its cholesterol-lowering effect but more heavily on its antioxidant potential to prevent endothelial damage and inhibit LDL oxidative modification in hypercholesterolemic animals.

Animals↗
PubMed1998

[Observation of inducing effect of five kinds of soft wood dust in micronucleus test].

The authors investigated the micronucleus frequencies (MP) in peripheral lymphocytes in 584 workers exposed to five kinds of soft wood dust and found that all kinds of soft wood dust could increase the micronucleus frequency. As the control's 95% confidential upper limit > or = 0.4% is defined as the standard for positivity the micronucleus positive frequency (MPF) in the exposure group is much higher than that in the control group (P < 0.01). Meanwhile the increase of exposure years may increase the MP, and the time-response relationship is evident (r = 0.90, P < 0.01). For different exposures, the MPFs are: 36.2% for linden, 26.3% for fir. 15.7% for lacebark pine, 9.6% for birch and 2.1% for polar. The positive rate of linden and fir exposure are significantly higher than that of the control group (P < 0.01). Water extract of these five kinds of soft wood dust can increase the frequencies of micronucleus in polychromatic red blood cell in mice's sternum marrow, which also showed a dose-response. The correlation coefficients are: 0.86 for linden 0.6 for fir, 0.39 for lacebark pine, 0.76 for birch and 0.73 for polar. All but the lacebark pine have the P value less than 0.01 (P < 0.01). At the dose of 15 g/kg body weight, micronucleus frequency induced by linden was the highest (0.8%), next were fir (0.71%), birch (0.65%), lacebark pine (0.63%), and polar (0.43%). The results from animal test are consistent with those from the exposure workers. These results suggest that there are some substances in soft wood which can induce chromosome aberration.

Adolescent↗
PubMed1998

[Transcatheter arterial chemo-embolization combined with CT-guided percutaneous intratumoral injection of lipiodol-ethanol for the treatment of primary hepatocellular carcinoma].

OBJECTIVE: To study the therapeutic effect of transcatheter arterial chemoembolization (TACE) combined with CT-guided percutaneous intratumoral injection of lipiodol-ethanol(ITLE) for primory hepatocellular carcinoma. METHODS: One hundred and two patients with primary hepatocellular carcinoma (PHC) were divided into two groups. In group A, 52 patients treated with TACE, and in group B, 50 patients were treated with TACE and ITLE. RESULTS: In group A 1-, 2-, and 3-year survival rate of the treated patients was 68.3%, 41.2%, and 21.4%, respectively. Histologic examination of cancer specimens obtained from hepatectomy and biopsy showed that TACE caused complete necrosis in only 26.1% of the treated cases. In contrast, in group B patients treated with TACE combined with ITLE, the 1-, 2-, and 3-year survival rate was 100%, 85.2% and 68.4%, respectively. Combination therapy resulted in complete histologic necroses in 86.4% of the treated cases. CONCLUSION: The therapeutic effect of TACE combined with CT-guided ITLE is much better than that of TACE alone.

Adult↗
PubMed1998

[Study on mechanism of bushen yugong granule in treating uterine dysgenesia].

OBJECTIVE: To explore the effective mechanism of Bushen Yugong Granule (BSYGG, a Chinese medicine preparation) in treating infertility due to uterine dysgeneia. METHODS: (1) Clinical study: Serum level of sex hormone and endometrial content of estradial receptor (ER) and progesterone receptor (PR) in follicle period of 60 patients (the tested group) were measured and compared before and after treatment, and the data were also compared with those of 70 normal women (the control group). (2) Experimental study: Rats were divided into the control group and 3 tested groups fed with different dose of BSYGG. Pathologic examination of pituitary, ovary and uterus of rats after BSYGG treatment, and serum levels of ER, PR were measured. Also, an estrogen activity experiment was adopted in some young cophorectomized rats. RESULTS: (1) Clinical study, the difference of serum sex hormone levels between the tested and the control group was insignificant. The percentage of patients in tested group with endometrial ER content over ++ was lower than that in the control group (46.9% vs 72.4%) significantly (P < 0.05), after treatment, it arised to 65.4% in test group, the change after treatment was significant (P < 0.05). (2) Experimental study: The number of follicle, weight of uterus and serum E2 level increased significantly after BSYGG treatment. The endometrial content of ER in the control group was 29.25 +/- 17.03%, while in the tested group, it was 67.75 +/- 24.56%-83.00 +/- 9.87% after treatment, the difference between the two groups was significant (P < 0.005). CONCLUSION: BSYGG has an estrogen-like activity, it could increase the endometrial content of ER, enhance the effect of estrogen on uterus and promote the uterine development, so as to elevate the fertilization rate.

Adult↗
PubMed1998

[Molecular genetic marker identification of traditional Chinese drug hippocampus].

Ancient DNA technique was used to extract DNA from 5 species of Chinese traditional drugs Hippocampus. The 12S rRNA gene fragment and cytochrome b gene fragment were amplified from DNA extract using Polymerase Chain Reaction (PCR) method. Restriction Fragment Length Polymorphism (RFLP) analysis and DNA sequence analysis were performed. The RFLP analysis method can identify 2 species of Hippocampus. The molecular genetic markers produced by DNA sequence method can identify all 5 species of Hippocampus. This method will be valuable for the identification of other animal drugs.

Cytochrome b Group↗
PubMed1998

[Molecular identification of the Chinese drug turtle shells].

This paper reports a new method to identify the Chinese drug turtle shells using PCR product direct sequencing method. DNA was extracted from tissues of the Chinese three-keeled pond turtle Chinemys reevesii and 20 other species of turtles occurring in China and Southeast Asian countries. One hundred and ten base pairs of mitochondrial 12S rRNA gene fragment were amplified from the extract using PCR technique and obtained sequences. These sequences were used to construct 12S rRNA gene fragment sequence database for the 21 turtle species. Comparison of these sequences indicated that the sequence from the Chinese three-keeled pond turtle is different from that of all the other 20 turtle species. The sequence divergence is 3.7-15.7%. DNA was extracted from 0.1-0.5 g of shell from 19 turtle shells provided by the Jiangsu Institute for Drug Control and 12S rRNA gene fragment was amplified and sequenced. Comparison of the sequences from the 19 turtle shells and 12S rRNA gene fragment sequence database indicated that only 3 samples are shells of the Chinese three-keeled pond turtle specified in the Phamacopoeia of the People's Republic of China and the others are substitutes. The technique used in the present paper was found to be effective and reliable for the identification of turtle shells.

Animals↗
PubMed1998

Further validation of SV40-like DNA in human pleural mesotheliomas.

We have confirmed in a second set of patients having human pleural mesothelioma that DNA for regions of the amino terminus of SV40 Tag can be amplified by the polymerase chain reaction. Moreover, other regions, including the carboxy terminus for Tag, and the regulatory region of SV40, are present in these specimens.

DNA, Viral↗
PubMed1997

A single nonamer from the Yersinia 60-kDa heat shock protein is the target of HLA-B27-restricted CTL response in Yersinia-induced reactive arthritis.

The reason for the high association of HLA-B27 with diseases such as ankylosing spondylitis and reactive arthritis is not clear. In reactive arthritis, the triggering bacteria are known, thus allowing investigation of their interaction with HLA-B27. CTL lines derived from five patients with Yersinia-induced reactive arthritis were raised by repeated stimulation in vitro with either Yersinia-infected autologous macrophages (four patients) or pooled peptides (three patients) having the HLA-B27-binding motif. The peptides were derived from five Yersinia proteins and from the chlamydial 57-kDa heat shock protein (hsp). Cytotoxicity of T cell lines was then tested against these peptides. Lytic activity was obtained with T cells stimulated with viable Yersinia or pooled peptides. Targets successfully used for lysis were cells pulsed with peptides from the Yersinia 60-kDa hsp, but not cells pulsed with peptides from other Yersinia proteins or the chlamydial hsp. T cell lines raised with 60-kDa peptides also lysed targets infected with Yersinia. Most interestingly, all three CTL lines tested (one raised with Yersinia; two with pool of peptides) recognized only one single peptide (321-329) of seven tested from the Yersinia hsp60. Cytotoxicity occurred only when target cells were matched for HLA-B27. This identification of an immunogenic peptide derived from an arthritogenic bacterium and presented by HLA-B27 opens the way for future investigation of the role of T cells specific for this peptide or cross-reacting peptides, in the immunopathology of HLA-B27-associated diseases.

Arthritis, Infectious↗
PubMed1997

Dihydrolipoamide dehydrogenase-binding protein of the human pyruvate dehydrogenase complex. DNA-derived amino acid sequence, expression, and reconstitution of the pyruvate dehydrogenase complex.

Protein X, recently renamed dihydrolipoamide dehydrogenase-binding protein (E3BP), is required for anchoring dihydrolipoamide dehydrogenase (E3) to the dihydrolipoamide transacetylase (E2) core of the pyruvate dehydrogenase complexes of eukaryotes. DNA and deduced protein sequences for E3BP of the human pyruvate dehydrogenase complex are reported here. With the exception of only a single lipoyl domain, the protein has a segmented multi-domain structure analogous to that of the E2 component of the complex. The protein has 46% amino acid sequence identity in its amino-terminal region with the second lipoyl domain of E2, 38% identity in its central region with the putative peripheral subunit-binding domain of E2, and 50% identity in its carboxyl-terminal region with the catalytic inner core domain of E2. The similarity in the latter domain stands in contrast to E3BP of Saccharomyces cerevisiae, which is quite different from its homologous transacetylase in this region. The putative catalytic site histidine residue present in the inner core domains of all dihydrolipoamide acyltransferases is replaced by a serine residue in human E3BP; thus, catalysis of coenzyme A acetylation by this protein is unlikely. Coexpression of cDNAs for E3BP and E2 resulted in the formation of an E2.E3BP subcomplex that spontaneously reconstituted the pyruvate dehydrogenase complex in the presence of native E3 and recombinant pyruvate decarboxylase (E1).

Amino Acid Sequence↗
PubMed1997

Nesting and shredding behavior as an indicator of hippocampal ischemic damage.

Mongolian gerbils were subjected to bilateral carotid artery occlusion, exposed to nesting material and examined daily. Five minutes of ischemia significantly reduced nesting behavior for 3 days; while 10 min attenuated nesting 6 days. Semi-novel re-exposure to nesting material also resulted in deficits. These disruptions in nesting behavior directly correlate to the amount of ischemic morphological damage and thus serve as a behavioral indicator of tissue damage.

Animals↗
PubMed1997

A high-throughput STAT binding assay using fluorescence polarization.

STAT (signal transducers and activators of transcription) is a class of transcription factors that are activated upon cytokine or growth factor binding to cell surface receptors. Activated STAT proteins dimerize, translocate into the nucleus, and activate transcription, leading to various immune responses. The inhibition of STAT binding to cell receptors might provide a means to modulate these immune responses. We developed a high-throughput biochemical assay to measure the interaction between an interferon-gamma receptor-derived phosphotyrosine-containing peptide and STAT1, using fluorescence polarization as the detection method. This assay can be used to screen for small molecules capable of disrupting receptor-STAT interactions.

Binding, Competitive↗