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Biomedical subjects

J Qiu

Publications and source records attributed to J Qiu.

At least 145 records · Page 8Linked to original sources
PubMed1997

[Alterations of retinoblastoma gene and its protein expression in aggressive bone tumors].

OBJECTIVE: To study the association between RB gene and the oncogenesis of bone tumors. METHODS: Southern blot and immunohistochemical techniques were used to detect the structural anomalies of RB gene in 34 cases of bone tumors and the expression of RB protein in 99 paraffin-embedded bone neoplasma. RESULTS: The deletion and/or rearrangement of RB gene were detected only in 42.9% (9/21) of osteosarcoma; lack of RB protein expression was noticed in 12 cases including 7 cases of osteosarcoma (7/26, 26.9%) and 5 cases of chondrosarcoma (5/23, 21.7%). Beniga giant cell tumor of bone and chondroblastoma showed positive RB protein expression; osteosarcoma cells presenting poor differentiation and apparent atypia all showed no expression of RB protein. Most of the high-grade chondrosarcoma also had no RB protein expression. CONCLUSION: The alterations of RB gene and loss of RB protein may play a role in the pathogenesis and progression of malignant bone neoplasms.

Bone Neoplasms↗
PubMed1997

[A study on TF no-mix orthodontic adhesive].

A no-mix orthodontic adhesive composed of primer and paste was developed. The adhesive eliminated the spatulation procedure to which most commercially available products were imperative, could quickly polymerize and cure by means of contact and slight compression of the primer with the paste. It featured high bond strength, convenient handling, enough working time, easy removal of extra adhesive around the bracket and no objectionable odour. The biological tests showed it was safe to use in orthodontic practice, and the results of clinical trials certified the reliable performance, effective bond and convenient use of the adhesive.

Adhesives↗
PubMed1997

[An observation of the percutaneous absorption of total alkaloids and terpenoid lactones of Tripterygium wilfordii].

The main ingredients of Tripterygium wilfordii are total alkaloids and terpenoid lactones. The authors studied the percutaneous absorption of these compounds on mice by means of ultravillet spectrophotometry. The results showed that these alksloids and lactones could pass through the skin of the mice. The rate of 12-hour percutaneous absorption was 13.40% for the former and 17.60% for the latter. After the application of Tripterygium wilfordii adhesive plaster to the human skin for 12 hours, the two ingredients were absorbed 17.34% and 22.13% respectively. This suggests that Tripterygium wilfordii can really be administered through the skin.

Administration, Topical↗
PubMed1997

[Study on enterovirus aetiology of CNS infection in Shantou].

Enterovirus isolation and serological assay were done in 236 cases of CNS infection in Shantou. 62 strains of virus (from 55 cases) were isolated from 257 samples of 236 cases (24.1%). 48 cases were positive among 57 cases (84.2%) by serological assay. 78 cases were positive for virus isolation and/or serological assay (33.1%). Virus infection included 33 cases of poliovirus (including 6 polio-I, 18 polio-II, 4 polio-III, 5 mixed infections), 21 cases of Coxsackie virus (including 6 CoxA24,7 CoxB1,2 CoxB4 and 6 CoxB5), 11 cases of ECHO virus (including 5 ECHO-7,2 ECHO-24 and each one of ECHO-11, 12, 15, 27), 10 cases of Enterovirus (including 3 EV-70, 7 EV-71), and 3 cases of mixed viral infection.

Adolescent↗
PubMed1997

[Study of dominant negative effect of the PLZF-RARalpha against the wild-type RARalpha in acute promyelocytic leukemia].

OBJECTIVE: To explore the role of promyelocytic leukemia zinc finger (PLZF) gene on 11q23 and RARalpha gene on 17q21. METHODS: Eight PLZF/RARalpha expression plasmids with deletions of different PLZF motifs were constructed by using PCR based-method. RESULTS AND CONCLUSION: By transient co-transfection, it was confirmed that PLZF/RARalpha had a dominant negative effect against the wild-type RARalpha, the POZ domain of PLZF/RARalpha was responsible for the dominant negative effect and the PLZF/RARalpha may play certain role through a spatial interaction with POZ.

Animals↗
PubMed1997

[Enrichment and determination of trace chlorobenzene compounds in water].

In this work, by using GDX-402 porous polymer beads as adsorbent and carbon disulfide as eluent, the conditions for enriching trace chlorobenzene compounds in water were investigated. Enriched eluate was directly injected into a column packed with 3.0% dihexyl sulfonic acid sodium/101 white support to be separated, and then detected by flame ionization detector under constant temperature. The method has been used successfully for the determination of trace of chlorobenzene compounds in water.

Chlorobenzenes↗
PubMed1997

[A technique of PVC detection in QRS wave].

A technique of PVC detection is described in this paper. The procedures of PVC analysis include noise detection, QRS detection, feature extraction and QRS wave classification. The interference is detected in hierarchy ways. A new non-linear transformation of ECG waveform is given to be taken as the QRS detection function. Taking this QRS detection function, the influence of noise and interference can be reduced greatly. By the technique of QRS template matching, QRS waveforms are sorted into different clusters in QRS wave form space. Then a linear classifier is used to identify the medical meaning of these clustes. Before the linear classifier is applied, the QRS waveforms are classified according to some special decision rules. 38 half-hour standard database is used to test the technique presented in this paper. The result shows t hat accuracy rate of PVC detection is better than 95%.

Cluster Analysis↗
PubMed1997

[The effect of substance P upon middle ear effusion of secretory otitis media and the mode of action].

This experiment aimed to explore the effects of substance P (SP) on secretory otitis media (SOM). Both immunohistochemistry ABC-GDN and image pattern analysis technique were adopted to investigate the relation between SP content of SOM middle ear mucosa and middle ear effusion, and observe the effect of SP receptor antagonist spantide and histamine H2 receptor blocker cimetidin on middle ear effusion. The findings showed: middle ear mucosa SP content tended to increase, and had positive correlation with middle ear effusion, intra-abdominally injecting 1 mg/ml Spantide and 1 mg/ml Cinetidin per day could have middle ear effusion decreased obviously, but the quantities of reduction were more significant. The results suggest that SP plays a role in SOM, might accelerate vasodilation and increase the permeability of cupillary in middle ear mucosa mediated by histamine.

Animals↗
PubMed1996

Formation of topoisomerase II alpha complexes with nascent DNA is related to VM-26-induced cytotoxicity.

Several clinically active anticancer drugs are known to interfere with DNA topoisomerase II activity. However, the importance of the individual alpha (170 kDa) and beta (180 kDa) isozymes as targets of topoisomerase II-active drugs is not clear. To address this question, human CCRF-CEM leukemia cells were incubated with bromodeoxyuridine, and either the nascent DNA or bulk DNA not undergoing replication was purified by immunoprecipitation with an anti-bromodeoxyuridine antibody. The topoisomerase II isozymes that coprecipitated with either the nascent DNA or bulk DNA were analyzed by Western blotting. The alpha isozyme formed complexes with nascent DNA in cells pretreated with either VM-26 or mitoxantrone, while the beta isozyme was only bound to bulk DNA. At moderately cytotoxic concentrations, VM-26 enhanced the binding of topoisomerase II alpha to nascent DNA at least 5.2-fold compared to bulk DNA. However, in VM-26 resistant CEM/VM-1 cells incubated with equitoxic concentrations of VM-26, topoisomerase II alpha complex formation with nascent DNA was decreased at least 5.5-fold compared to bulk DNA. Drug-induced binding of topoisomerase II beta with bulk DNA in CEM/VM-1 cells did not correlate with cytotoxicity. Collectively, these results indicate that the formation of VM-26 stabilized complexes of topoisomerase II alpha with nascent DNA are critical to the development of cytotoxicity, and that resistance of CEM/VM-1 cells to VM-26 is related to impaired formation of these complexes. The results also provide indirect evidence that topoisomerase II alpha is involved in DNA, replication.

Antineoplastic Agents, Phytogenic↗
PubMed1996

4-Hydroxyphenyl retinamide is a highly selective activator of retinoid receptors.

Retinoids have shown promise as anti-cancer and cancer preventative agents. All-trans-N-(4-hydroxyphenyl)retinamide (4HPR) belongs to a new group of retinoids that not only inhibit the proliferation of cancer cells but also can induce apoptosis in certain cancer cells. Because of its increased efficacy against cancer cells and its low toxicity it has been entered into a number of clinical trials. However, its mechanism of action is not known, and it had been assumed that it is not a true retinoid. Here we analyze its ability to function as an activator of nuclear retinoid receptors (RARs and RXRs). We observe that, in transactivation assays, 4HPR is a potent transactivator with RARgamma and a moderate activator with RARbeta but is not an activator with RARalpha and RXRalpha. Furthermore, RARgamma-selective transactivation by 4HPR is enhanced on some response elements and reduced on others when compared to natural retinoids. In contrast to transactivation, 4HPR in transrepression assays functions mostly with RARalpha, RARbeta, and RXRalpha. Optimal receptor activation is seen at 4HPR concentrations at which it is a potent growth inhibitor and inducer of apoptosis. We conclude that 4HPR is a highly selective activator of retinoid receptors. We propose that this selective activation of the nuclear receptors is likely to be the basis for its specific biological activities and its favorable pharmaceutical properties.

Anticarcinogenic Agents↗
PubMed1996

A rapid polarographic immunoassay based on the anodic current of metal labeling.

A heterogeneous voltammetric immunoassay of human serum albumin (HSA) based on the anodic current of metal labeling was studied. HSA was covalently coupled to diethylenetriaminepentaacetic anhydride and labeled with In3+. A heterogeneous competitive immunochemical reaction was carried out in the wells of a microtiter plate. The In3+ label was released in 1 M HCl solution and determined by simplified anodic stripping neopolarography. HSA could be detected in the concentration range of 4.0-50 microg ml-1. The method was used to determine HSA in serum specimens, and the results were in good agreement with those obtained with dye binding spectrophotometry.

Chelating Agents↗