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Biomedical subjects

J Ju

Publications and source records attributed to J Ju.

At least 37 records · Page 2Linked to original sources
PubMed1999

[Studies on chemical constituents of seeds of Desmos chinensis Lour].

OBJECTIVE: To investigate the chemical constituents of Desmos chinensis. METHOD: Various column chromatographic techniques were employed for the isolation and purification of constituents from the ethanol extract. The structures were elucidated by spectral analysis. RESULT: Eleven compounds were isolated and identified as lawinal(1), desmosal(2), desmethoxymatteucinol(3), unonal(4), isounonal(5), desmosflavone(6), allantoic acid(7), succinic acid(8), daucosterol(9), beta-sitosterol(10) and stearic acid(11). The structures of compounds 1 and 2 were reconfirmed by NOEDS technique. CONCLUSION: Compound 2 is a new natural product and 7, 8 and 9 were found from this plant for the first time.

Annonaceae↗
PubMed1999

[Dynamic observation of serological and histological changes of Chinese rhesus monkeys infected by hepatitis G virus].

OBJECTIVE: To study the genesis, development and pathogenesis of hepatitis G. METHODS: The Chinese Rhesus monkeys were intravenously injected with the serum from a hepatitis G patient only with HGV RNA positive. The dynamic changes of serum and liver tissues of the animals were observed before and after infection. Also the immunohistochemical study were done with monocolonal antibody against NS5 gene antigen of HGV. One male monkey was dissected and the internal organs were taken for histological examination 18 months after infection. RESULTS: Serum ALT and AST became increasing 30 days after infection and showed abnormal continuously for 9 months. Spotty and focal necrosis and piecemeal necrosis were found in liver tissue from 2 to 18 months after infection. Positive staining of HGV antigen was present in cytoplasm of liver cells by immunohistochemistry. Histological observation showed that the internal organs were normal except the liver tissue in which the damages were similar with that in hepatitis. CONCLUSION: The successful infection of Chinese Rhesus monkey by serum from hepatitis G patient can used as a good animal model for the study of hepatitis G.

Animals↗
PubMed1999

Isoaspartyl bond formation within N-terminal sequences of collagen type I: implications for their use as markers of collagen degradation.

An ELISA was developed for the measurement of N-telopeptides of the alpha2(I) collagen chain containing an isomerized Asp-Gly bond (beta-peptide) using polyclonal antibodies raised against the synthetic peptide. The presence of this isomerized form in bone was confirmed by positive immunostaining of sections from human femoral head. The ELISA was used to measure isomerized peptide in both human bone digests and urine samples, showing that an isoaspartyl rearrangement occurs in the Asp-Gly sequence at the N-terminus of the alpha2(I) chain in an analogous fashion to that found in the C-terminal telopeptide of the alpha1(I) chain of collagen. Using this assay in conjunction with a monoclonal antibody ELISA to the non-isomerized alpha2(I) N-telopeptide (alpha-peptide), ratios of isomerized to normal peptides were estimated in the bone and urine samples. Urinary alpha2(I) N-telopeptides showed a higher degree of isomerization than the peptides derived from a human bone digest. This is possibly due to relative enrichment of the isoaspartyl-bonded peptide during metabolic processing due to the proximity of the isoaspartyl bond to a cross-link site. Urinary concentrations of isomerized and normal peptides were determined in normal adults, children, post-menopausal control subjects and subjects with osteoporosis. A lower ratio of beta-peptide to alpha-peptide was observed in children's urine, indicative of a higher rate of bone metabolism allowing less time for the isomerization to occur. No significant differences were found between the post-menopausal control and osteoporotic populations although the trends observed supported the hypothesis that a lower degree of isomerization may be associated with faster bone turnover.

Adult↗
PubMed1998

Antioxidant action via p53-mediated apoptosis.

The biological effects of antioxidants are often considered in terms of their effects on oxygen or lipid radicals. However, antioxidants can also exert their effects through altering the cellular redox potential. Herein, we report that sulfur-containing antioxidants such as N-acetylcysteine and dimercaptopropanol induced apoptosis in several transformed cell lines and transformed primary cultures but not in normal cells. In contrast, chain-breaking antioxidants such as vitamin E lacked this activity. An increased glutathione level was not required for apoptosis; however, all apoptosis-inducing antioxidants elevated the total cellular thiol levels. Antioxidant-induced apoptosis required the p53 tumor suppressor gene. N-Acetylcysteine elevated p53 expression posttranscriptionally by increasing the rate of p53 mRNA translation rather than by altering the protein stability. The p53 induction occurred in normal cells. These observations indicate a redox sensor for p53 induction in vivo, with additional transformation-specific information being required for apoptosis. Manipulating p53-dependent apoptosis with nontoxic antioxidants may have a direct clinical application.

Acetylcysteine↗
PubMed1998

Forespore expression and processing of the SigE transcription factor in wild-type and mutant Bacillus subtilis.

SigmaE is a mother cell-specific transcription factor of sporulating Bacillus subtilis that is derived from an inactive precursor protein (pro-sigmaE). To examine the process that prevents sigmaE activity from developing in the forespore, we fused the sigmaE structural gene (sigE) to forespore-specific promoters (PdacF and PspoIIIG), placed these fusions at sites on the B. subtilis chromosome which translocate into the forespore either early or late, and used Western blot analysis to monitor SigE accumulation and pro-sigmaE processing. sigE alleles, placed at sites which entered the forespore early, were found to generate more protein product than the same fusion placed at a late entering site. SigE accumulation and processing in the forespore were enhanced by null mutations in spoIIIE, a gene whose product is essential for translocation of the distal portion of the B. subtilis chromosome into the forespore. In other experiments, a chimera of pro-sigmaE and green fluorescence protein, previously shown to be unprocessed if it is synthesized within the forespore, was found to be processed in this compartment if coexpressed with the gene for the pro-sigmaE-processing enzyme, SpoIIGA. The need for spoIIGA coexpression is obviated in the absence of SpoIIIE. We interpret these results as evidence that selective degradation of both SigE and SpoIIGA prevent mature sigmaE from accumulating in the forespore compartment of wild-type B. subtilis. Presumably, a gene(s) located at a site that is distal to the origin of chromosome transfer is responsible for this phenomenon when it is translocated and expressed in the forespore.

Alleles↗
PubMed1998

[Diagnosis and treatment of thoracic outlet syndrome].

OBJECTIVE: Thoracic outlet syndrome (TOS) is clinically common, but liable to be misdiagnosed. We would like to emphasize the recognition of TOS, and through thorough examination for a complete relief from indicated operation. METHODS: 13 cases receiving surgical operations in PUMC hospital from 1982 to 1996 are reported and discussed the cause of misdiagnosis, investigate the various kinds of abnormalities and compare the result of operation. RESULTS: 92% of the patients had experence of being misdiagnosed for other diseases, the history may be as long as 10 years. In the operations we found 8 kinds of anatomic abnormalities that cause the symptoms and complete relief is satisfactory. CONCLUSIONS: We have to emphasize the recognition of TOS. The thorough physical examination is important to diagnosis. Patients with typical and apparent symptoms need an operation to relieve the thoracic outlet through the transaxillary approach.

Adolescent↗
PubMed1998

Desensitization and sensitization of cells to fluoropyrimidines with different antisenses directed against thymidylate synthase messenger RNA.

Previous studies have shown that the cytotoxicity of fluoropyrimidines is mediated, in large part, by inhibition of the enzyme thymidylate synthase (TS). The aim of this study was to determine whether the chemosensitivity of human cancer cells to fluoropyrimidines could be increased by decreasing TS expression with antisense oligodeoxyribonucleotides (ODNs). ODNs (18-mers) targeted at the AUG translational initiation site of TS mRNA inhibited translation in a sequence- and dose-dependent manner in a rabbit reticulocyte lysate in vitro translation system. Treatment of human colon cancer HT-29 cells with antisense ODNs decreased TS catalytic activity in the cells in a dose-dependent manner over a short period, but the longer-term effect of the TS antisense ODN treatment was actually to increase the amount of TS in the cells and to decrease their sensitivity to 5-fluoro-2'-deoxyuridine (FdUrd). However, when human nasopharyngeal cancer KB31 cells were transfected with a plasmid (pHaMAGRP) construct containing the TS antisense fragment (+ 1 to + 422) under the control of a glucose-regulated promoter, the expression of both TS protein and TS catalytic activity was decreased by nearly 30% (P = 0.014), and sensitivity of these cells to FdUrd was enhanced by approximately 8-fold (P = 0.021). No changes in the levels of expression of TS protein or FdUrd-associated cytotoxicity were observed in control, vector-transfected cells. No change was observed in the sensitivity of transfected cells toward either cisplatin or Adriamycin. These results show that the level of expression of TS in human malignant cells can be down-regulated with antisense TS RNA, and their sensitivity to fluoropyrimidines can, thereby, be increased.

Animals↗
PubMed1997

Bacillus subtilis Pro-sigmaE fusion protein localizes to the forespore septum and fails to be processed when synthesized in the forespore.

Endospore formation in Bacillus subtilis begins with an asymmetric cell division that partitions the bacterium into mother cell and forespore compartments. Mother cell-specific gene expression is initiated by sigmaE, a transcription factor that is active only in the mother cell but which existed as an inactive precursor (pro-sigmaE) in the predivisional cell. Activation of pro-sigmaE involves the removal of 27 amino acids from its amino terminus. A chimera of pro-sigmaE and the green fluorescent protein (GFP) was expressed from either the normal sigE promoter (P(spoIIG)), which places pro-sigmaE::GFP in both mother cell and forespore compartments, or the forespore-specific promoter (P(dacF)), which produces pro-sigmaE::GFP only in the forespore compartment. The pro-sigmaE::GFP expressed from P(spoIIG), but not P(dacF), was converted to a lower-molecular-weight form by a mechanism dependent on gene products (SpoIIGA and sigmaF) that are essential for normal pro-sigmaE processing. This finding is consistent with the pro-sigmaE processing reaction occurring only in the mother cell compartment. In processing-deficient cells, pro-sigmaE::GFP was found to accumulate at the septal membrane, a location where its processing apparatus would be susceptible to triggering from the adjoining forespore.

Bacillus subtilis↗
PubMed1997

[Clonning and sequencing of partial gene of hepatitis G virus (HGV) from Nanjing of China].

Partial gene of hepatitis G virus (HGV) was cloned and sequenced from the serum of a patient with post-transfusion hepatitis C in Nanjing of China by reverse transcription-polymerase chain reaction (RT-PCR). The sequence showed 89.09%, 92.12%, 87.27%, 93.94% nucleotide identity over the corresponding region of HGU44402, HGU45966, HGU36380 in America and HGV isolate in Hebei Province of China respectively. Forty patients with post-transfusion hepatitis C and thirty patients with hepatitis non A-E were detected for HGV RNA by RT-PCR, the HGV RNA positive rate were 10.00% and 6.67% respectively.

Base Sequence↗
PubMed1996

Cyanine dyes with high absorption cross section as donor chromophores in energy transfer primers.

Energy transfer (ET) fluorescent primers are significantly superior to single dye-labeled primers for DNA sequencing and multiplex genetic analyses (Ju, J., Glazer, A. N., and Mathies, R. A. (1996) Nature Med. 2, 246-249). We describe here ET primers in which a donor chromophore with a large absorption cross section but a low fluorescence quantum yield is exploited to increase the Stokes-shifted fluorescence emission of acceptor dyes. The new ET primers have 3-(epsilon-carboxy-pentyl)-3'ethyl-5,5'-dimethyloxacarbocyanine (CYA; epsilon M488nm 142,000 M-1 cm-1) at the 5' -end as a common energy donor, and fluorescein or rhodamine derivatives (FAM, R6G, TAMRA, and ROX), attached to a modified thymidine 10 bases away within the primer sequence, as acceptors. With 488-nm excitation, the fluorescence emission intensity of these four ET primers is 1.4- to 24-fold stronger than that of the corresponding primers labeled only with the single acceptor dye. When compared with the corresponding ET primers with a fluorescein derivative (FAM; epsilon M488nm 60,000 M-1 cm-1) as donor, the fluorescence emissions of primers with CYA as donor and FAM, R6G, TAMRA, and ROX as acceptors are respectively 0.8-, 1.0-, 1.7-, and 1.7-fold as intense. The low fluorescence quantum yield of the CYA donor resulted in distinct fluorescence signals for the DNA-sequencing fragments with much lower crosstalk between the four detection channels than that seen with ET primers based on a FAM donor. With single-stranded M13mp18 DNA as the template, the CYA ET primers provided DNA sequences on a four-color capilary sequencer with 100% accuracy in the first 500 bases.

Carbocyanines↗
PubMed1996

Energy transfer primers with 5- or 6-carboxyrhodamine-6G as acceptor chromophores.

Energy-transfer (ET) fluorescent primers for DNA sequencing and multiplex genetic analysis (Ju, J., Ruan, C., Fuller, C. W., Glazer, A. N., and Mathies, R. A. (1995) Proc. Natl. Acad. Sci. USA 92, 4347-4351) are named according to the convention D-N-A, where D is the donor, N is the number of bases between the donor and the acceptor, and A is the acceptor. Thus, a primer that carries 6-carboxyfluorescein (FAM) at the 5'-end and 6-carboxy-4', 5'-dichloro-2',7'-dimethoxyfluorescein (JOE) attached to a modified thymidine 10 bases away is designated F10J. We describe here new ET primers, with 5- or 6-carboxyrhodamine-6G (G5 or G6) as acceptors (with FAM as the donor) in place of JOE, with improved match in the electrophoretic mobilities of the DNA fragments extended from the ET dye-labeled primers, and less overlap in the fluorescence emission of the various labeled DNA fragments. This reduced spectral overlap is most likely due to the narrower emission from G5 or G6 in F10G compared to that from JOE in F10J. With single-stranded M13mp18 DNA as the template, a typical run with F10G6 and three other ET primers on a capillary sequencer provided DNA sequences with 99% accuracy in the first 620 bases.

Base Sequence↗
PubMed1996

Cassette labeling for facile construction of energy transfer fluorescent primers.

DNA primer sets, labeled with two fluorescent dyes to exploit fluorescence energy transfer (ET), can be efficiently excited with a single laser line and emit strong fluorescence at distinctive wavelengths. Such ET primers are superior to single fluorophore-labeled primers for DNA sequencing and other multiple color-based analyses [J. Ju, C. Ruan, C. W. Fuller, A. N. Glazer and R. A. Mathies (1995) Proc. Natl. Acad. Sci. USA 92, 4347-4351]. We describe here a novel method of constructing fluorescent primers using a universal ET cassette that can be incorporated by conventional synthesis at the 5'-end of an oligonucleotide primer of any sequence. In this cassette, the donor and acceptor fluorophores are separated by a polymer spacer (S6) formed by six 1',2'-dideoxyribose phosphate monomers (S). The donor is attached to the 5' side of the ribose spacer and the acceptor to a modified thymidine attached to the 3' end of the ribose spacer in the ET cassette. The resulting primers, labeled with 6-carboxy-fluorescein as the donor and other fluorescein and rhodamine dyes as acceptors, display well-separated acceptor emission spectra with 2-12-fold enhanced fluorescence intensity relative to that of the corresponding single dye-labeled primers. With single- stranded M13mp18DNA as the template, a typical run with these ET primers on a capillary sequencer provides DNA sequences with 99% accuracy in the first 550 bases using the same amount of DNA template as that typically required using a four-color slab gel automated sequencer.

Base Sequence↗
PubMed1996

High-resolution capillary array electrophoretic sizing of multiplexed short tandem repeat loci using energy-transfer fluorescent primers.

Short tandem repeat regions (STRs) from the polymorphic loci VWFA, THO1, TPO and CSF were amplified by the multiplex polymerase chain reaction (PCR) and analyzed by capillary array electrophoresis with fluorescence detection of energy transfer (ET) labels. The fluorescent ET primers are labeled with one fluorescein at the 5' end and a second fluorescein at the position of the 7th or 9th (modified) base to produce fragments that fluoresce in the green (lambda max = 525 nm). M13 A-track sequencing fragments, used as an internal sizing standard, were generated with a universal primer that has a donor fluorescein at the 5' end and a rhodamine acceptor at the position of the 11th (modified) base to produce fragments fluorescing in the red (> 590 nm). The labeled DNA fragments were excited at 488 nm, and the fluorescence was detected with a two-color confocal fluorescence scanner. Separations were performed on arrays of hollow fused silica capillaries filled with denaturing and replaceable hydroxyethyl cellulose sieving matrices. Separations were complete in less than 50 min, and single base resolution as well as reproducible STR sizing was achieved. The relative standard deviation in sizing was below 0.6%. This work establishes the feasibility of high-resolution, high-speed and high-throughput STR typing of single-stranded DNA fragments using capillary array electrophoresis.

Bacteriophage M13↗