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Biomedical subjects

B Du

Publications and source records attributed to B Du.

At least 55 records · Page 3Linked to original sources
PubMed1997

[Clinical study of systemic inflammatory response syndrome and multiple organ dysfunction syndrome in critically patients].

We defined the epidemiology of systemic inflammatory response syndrome (SIRS) and multiple organ dysfunction syndrome (MODS) in critically ill patients, and evaluated the procession from SIRS to MODS and the therapeutic strategies. 230 patients were studied prospectively until discharge or death. On admission, the morbidity rate of SIRS was 71.3%. The mortality rate of the patients with SIRS was 18.9%. MODS was developed in 65 patients (28.3%), and 33 patients dided (50.8%). In SIRS patients with non-infectious SIRS, sepsis and septic shock, the morbidity rates of MODS were 22.8%, 61.1% and 85.7%, and the mortality rates were 11.4%, 30.6% and 50.0% respectively. The outcome of critically ill patients may be improved if SIRS is early diagnosed and the body inflammatory response is reglulated properly.

China↗
PubMed1997

[Primary study on the sensitivity of cytokinesis blocked micronucleus assay in CHL cells].

Studies were performed to determine the cytochalasin B induced binucleated cell percentage influenced by clastogens and aneuploidgens and to compare the efficacy of cytokinesis blocked binucleated cells for scoring micronuclei with that of the conventional mononucleated method following the treatment with mitomycin C, methyl methanesulforate, colchicin and chloral hydrate. The results showed that mitomycin C decreased the binucleated cell percentage induced by cytochalasin B, whereas colchicin increased the frequencies of binucleated cells. The frequencies of micronuclei in binucleated cells were not significantly higher than those in the conventional mononucleated cells. The results suggest that cytokinesis blocked method is not more sensitive than the conventional method for scoring micronuclei. The factors that may influence the cytokinesis blocked micronucleus assay have been discussed.

Animals↗
PubMed1997

[Quantitative observation of expression of proliferation cell nuclear antigen in nasopharyngeal carcinoma].

Eighty-two cases of nasopharyngeal squamous cell carcinoma and twenty-five cases of nasopharyngitis were studied by means of LAS-SP immunohistochemical method with monoclonal anti-PCNA antibody and using image pattern analysis technique; correlation analysis was performed on expression of PCNA and five-year survival rate. It was shown: 1. The cell proliferative index and pathological grading of NPC were positively correlated, and the cell proliferative index and five-year survival rate negatively correlated. 2. PCNA expression level and pathological grading of NPC were positively correlated, and PCNA expression levels and five years survival rate negatively correlated in all pathological gradings of NPC except the vesicular nucleus cell carcinoma. The results indicate that PCNA affects proliferation activity of NPC and there are bright prospects for their application in the clinic. Expression of PCNA may also become a good indicator of the prognosis of NPC and the choice of treatment.

Carcinoma, Squamous Cell↗
PubMed1997

[Relationship between nasal airflow sensation and nasal patency].

The relationship between nasal airflow sensation and nasal patency was evaluated by means of visual analogue test and anterior rhinomanometry. It was demonstrated that there is no significant correlation between the subjective sensation of nasal airflow and objective assessment of nasal airflow resistance. The site responsible for sensing airflow is located in the nasal vestibule. The volatile agents used in traditional Chinese medicine for nasal obstruction, such as camphor and menthol, could only improve the nasal sensation of airflow without alteration of nasal airway resistance. Our results suggested that the nasal sensation of airflow could not reflect real patency completely. Therefore, assessment of subjective sensation of airflow and measurement of nasal airway resistance combined must be used in the diagnosis and treatment of nasally obstructed patients.

Adult↗
PubMed1997

[Recombinant AAV-LMP-induced LMP specific cytotoxic response to autologous lymphoblastoid cell lines tranformed by Epstein-Barr virus].

Epstein-Barr virus is believed to be controlled in normal host by virus specific cytotoxic T lymphocytes (CTL). Although unable to eliminate EBV from the body, CTL seems to be essential in control of latently infected cells. Infusion of autologous EBV specific CTL, which can be produced in laboratory by separating lymphocytes from patients and stimulating them with EBV antigen, will provide an effective method of preventing and treating EBV-related diseases. We inserted the LMP gene of EB virus into an AAV vector pACP and packed it in Ad2 infected 293 cells by co-transfecting with plasmid Ad8, which produced the recombinant virus rAAV-LMP. The recombinant virus was used to infect stimulating cells and LMP antigen was expressed on the surface of these cells. Then the stimulating cells were irradiated and co-cultured with T lymphocytes. The EBV specific CTLs were obtained. The target cells were autologous LCLs from EBV-transformed B lymphocytes. The CTL activity was assayed by BLT activity method. The result indicated that all the four CTL strains could recognize and kill their target cells. This study has laid the technical basis for us to prevent and treat nasopharyngeal carcinoma in China with molecular biological methods.

Cell Line↗
PubMed1997

[The effects of vibratory acoustic stimulation on fetal heart rate and body movement of normal fetuses at different gestational ages].

OBJECTIVE: To study the effects of vibratory acoustic stimulation (VAS) on fetal heart rate (FHR) and fetal movement (FM) of normal fetu at different gestational ages. METHOD: 435 normal second and third-trimester pregnancies were studied using real time ultrasonography. FHR baseline was recorded. Then a five-second VAS was given and FM and (or) FHR was observed. The results of vibroacoustic stimulation testing (VAS-T), sound-provoked fetal movement (SPFM) and the amplitude of FHR acceleration were evaluated. RESULTS: (1) The fetus started to response to VAS from the 24th gestational week, but most could not reach the diagnostic criteria of VAS-T. The responses of FM were normal. (2) From 28 week on, 90% of the fetu showed marked FM and acceleration of FHR after VAS. Over 98% of the term babies were reactive. (3) The detective rates of SPFM appeared significantly earlier than that of VAS-T. CONCLUSION: It suggested that the development of fetal nervous system was matured at 28 weeks, and the development of motor nerves was earlier than that of the autonomic nerves.

Acoustic Stimulation↗
PubMed1996

Direct cytotoxicity of HIV-1 envelope protein gp120 on human NT neurons.

A new in vitro system comprising a pure population of neurons, human NT cells, was used to characterize the direct neurotoxic effect of HIV-1 envelope protein gp120. Cytotoxicity was monitored by a quantitative assay after exposure to recombinant gp120 in the presence or absence of other reagents. Treatment of mature NT neurons with various doses of gp120 for 24 h caused a decrease of up to 27% in the number of viable cells. This neurotoxicity was abolished by co-treatment with either D-2-amino-5-phosphonopentanoic acid (APV), MK801 or nimodipine, or by culturing cells in a Ca(2+)-free environment. Taken together, these data indicate that gp120 exerts a direct neurotoxic effect by acting through NMDA receptors and Ca2+ channels.

2-Amino-5-phosphonovalerate↗
PubMed1996

Efficient transduction of human neurons with an adeno-associated virus vector.

An adeno-associated virus vector containing a lacZ gene driven by a CMV immediate-early promoter (AAV beta-gal) was evaluated with respect to its transduction efficiency and integration ability in nondividing human NT neurons. A dose-dependent pattern in transduction efficiency of the AAV beta-gal was demonstrated immunocytochemically, with up to 100% of the neurons expressing the gene product. No neurotoxic effects of the vector were detected. Quantitative PCR analyses of high molecular weight cellular DNA from the transduced neurons indicated that the copy number of the AAV beta-gal genome increased gradually in a time dependent manner, suggesting a slow but progressive rate of vector integration over a period of approximately 1 week following transduction. Equal or greater transduction efficiency of the AAV beta-gal into NT neurons than into a standard target cell line indicated that the NT neurons were readily susceptible to AAV-mediated gene transfer. This study demonstrates that AAV-based vectors can efficiently transduce and stably express a foreign gene in post-mitotic human neurons.

Base Sequence↗
PubMed1996

[Nosocomial bacterial infection in comprehensive intensive care unit].

OBJECTIVE: To establish the prevalence of nosocomial bacterial infection and changes in resistance in a comprehensive intensive care unit. METHODS: We retrospectively analyzed all the bacterial isolates of ICU, PUMC Hospital from 1989 to 1994, such as the species and resistance pattern. RESULTS: Among all bacterial isolates, the percentage of Gram-positive cocci steadily increased (16% in 1989, 33% in 1994), while that of Gram-negative bacilli decreased (84% in 1989, 67% in 1994). The most prevalent isolates of Gram-negative pathogens were Pseudomonas aeruginosa, Acinetobacter baumanii, inducible Enterobacteriaceae and Xanthomonas maltophilia, with imipenem and amikacin as the most susceptible antibiotics. Enterococci, oxacillin-resistant Staphylococcus epidermidis and oxacillin-resistant Staphylococcus aureus accounted for 44%, 21% and 10%, respectively. The resistant rate of these three Gram-positive bacteria to vancomycin were 19%, 0% and 0%. CONCLUSION: Understanding of the epidemiological data and changes of bacterial resistance profile is prerequisite to rational use of antibiotics, which is crucial to reducing the resistance of nosocomial infection pathogens.

Cross Infection↗
PubMed1996

Translocation of protein kinase C-delta by PDGF in cultured vascular smooth muscle cells: inhibition by TGF-beta 1.

The migration and proliferation of vascular smooth muscle cells (SMC) into the neointima are important early events in the development of atherosclerosis and post-angioplasty restenosis. The stimulation of SMC migration by platelet derived growth factor (PDGF) involves the induction of protein kinase C activity. Using immunoblot techniques, we demonstrated that rat aortic SMC express a pattern of PKC isoforms which includes PKC-alpha, delta, epsilon, zeta and eta. Upon exposure to PDGF-BB, a fraction of PKC-delta was rapidly translocated from the cytosol to the post-nuclear particulate fraction at 15 seconds and reached an apparent maximum at 30 minutes. In contrast, PKC-alpha and zeta were not translocated by PDGF-BB, TGF-beta 1, which inhibits PDGF-induced DNA synthesis and chemotaxis, reduced the immunoreactive levels of PKC-delta and blocked the PDGF-induced translocation of PKC-delta to the particulate fraction. This suggests that the activation of PKC-delta by translocation to the particulate fraction may play an important role in the control of vascular smooth muscle cell migration by PDGF and TGF-beta 1.

Amino Acid Sequence↗
PubMed1996

[Invasive fungal infection in 3447 autopsy cases].

OBJECTIVE: To evaluate the prevalence of invasive fungal infection at autopsy. METHOD: To retrospectively analyse 3447 autopsy cases in Peking Union Medical College Hospital from 1953 to 1993. RESULTS: There were 85 cases of invasive fungal infection at autopsy among 3447 cases. The prevalence steadily increased, especially during the recent 20 years. Among the 85 cases, only 5 patients were diagnosed clinically (5.9%). The primary diseases were mainly leukemia, cancer, and sepsis. Lung was involved in 70% of the cases, and 85% of the pathogens were fungi. CONCLUSIONS: Fungus has become a major pathogen in nosocomial infection. The prophylactic use of antifungal agents is recommended in high-risk patients because of the difficulty to establish the clinical diagnosis of invasive fungal infection.

China↗
PubMed1996

[The correlation between gastric intramucosal pH and oxygen delivery in patients with septic shock].

We studied the correlation of intramucosal pH (pHi), oxygen delivery (DO2) and oxygen consumption (VO2) in 21 patients with septic shock, and found that pHi decreased dramatically (P < 0.05) in nonsurvivors while it had no significant change in survivors. In survivors, there was a positive correlation between pHi and DO2 (r = 0.71, P < 0.001), pHi and VO2 (r = 0.63, P < 0.001) when DO2 was below the critical level of 641 ml/min/m2. We concluded that the change of pHi is related with the prognosis of septic shock. The correlation between pHi and DO2 proves the oxygen supply dependency of VO2. The hypoxia in tissue level is the main factor which results in a high mortality of septic shock patients. pHi is a reliable and useful parameter not only for prognosis, but also for titrating the therapy in septic shock if pHi is monitored serially together with DO2.

Adult↗
PubMed1996

[The relationship of non-Hodgkin's lymphoma with P16 protein expression].

The expression of P16 protein was examined in 45 cases of non-Hodgkin's lymphoma (NHL), 4 cases of reactive hyperplasia of lymph node (RHLN) and 6 cases of normal spleen with immunohistochemical staining. Positive reaction of P16 protein was observed in some lymphocytes of RHLN and splenic nodule and around splenic sinus. The positive rate of P16 protein expression in NHL was 37.8% (17/45). The positive rates of P16 protein expression for the low intermadiate- and high-grade malignancy groups were 66.7% (10/15), 37.5% (6/16) and 7.1% (1/14) respectively. There was a significant difference between the low malignancy NHL and the high malignancy NHL (P < 0.005) in expression rate of P16 protein. It suggests that P16 protein expression may be one of the important parameters in estimating the prognosis of patients with NHL.

Adolescent↗
PubMed1995

HIV-1 Tat modulates invasion by a bacterial enteric pathogen into a human intestinal cell line.

OBJECTIVE: To explore the possibility that an HIV-1 gene product may modulate entry of an invasive enteric pathogen into a terminally differentiated human intestinal cell line. HIV-1 Tat was selected for investigation because of its unique ability to cross cell membranes. METHODS: After transient transfection of HT29-C1 cells with plasmids containing HIV-1 long terminal repeat (LTR)-lacZ plus a Tat expression cassette, or with a pSR-lacZ control plasmid, bacterial invasion assays were performed on both groups of cells utilizing a clinical Salmonella isolate. Assays were performed concurrently on a control group of non-transfected cells. A second series of experiments compared bacterial invasion into cells transfected with the Tat expression vector alone versus cells transfected with either an isogenic expression vector that did not make Tat, or with pSR-lacZ. Finally, the ability of exogenous Tat protein to transactivate an HIV-1 LTR-chloramphenicol acetyltransferase (CAT) plasmid which had been transfected into HT29-C1 cells and to modulate Salmonella invasion was also assessed. RESULTS: HT29-C1 cells transfected with a Tat expression vector, either alone or in combination with another plasmid, were significantly less susceptible to bacterial invasion than cells that either did not undergo transfection, were transfected with an otherwise isogenic expression vector without Tat, or transfected with an unrelated plasmid. Duplicate experiments also demonstrated that exogenous purified Tat protein transactivated an HIV-1 LTR-CAT plasmid which had been transfected into HT29-C1 cells and inhibited Salmonella invasion compared with unexposed cells. CONCLUSION: HIV-1 Tat inhibits Salmonella invasion of a human enterocyte cell line whether the protein is expressed intracellularly or provided exogenously.

Animals↗
PubMed1995

Specific inhibition of eIF-5A and collagen hydroxylation by a single agent. Antiproliferative and fibrosuppressive effects on smooth muscle cells from human coronary arteries.

Restenosis occurs in 35% of patients within months after balloon angioplasty, due to a fibroproliferative response to vascular injury. These studies describe a combined fibrosuppressive/antiproliferative strategy on smooth muscle cells cultured from human primary atherosclerotic and restenotic coronary arteries and from normal rat aortas. L-Mimosine suppressed the posttranslational hydroxylation of the precursors for collagen and for eukaryotic initiation factor-5A (eIF-5A) by directly inhibiting the specific protein hydroxylases involved, prolyl 4-hydroxylase (E.C. 1.14.11.2) and deoxyhypusyl hydroxylase (E.C. 1.14.99.29), respectively. Inhibition of deoxyhypusyl hydroxylation correlated with a dose-dependent inhibition of DNA synthesis. Inhibition of prolyl hydroxylation caused a dose-dependent reduction in the secretion of hydroxyproline-containing protein and decreased the formation of procollagen types I and III. The antifibroproliferative action could not be attributed to nonspecific or toxic effects of mimosine, appeared to be selective for the hydroxylation step in the biosynthesis of the procollagens and of eIF-5A, and was reversible upon removal of the compound. The strategy of targeting these two protein hydroxylases has important implications for the pathophysiology of restenosis and for the development of agents to control fibroproliferative diseases.

Angioplasty, Balloon↗
PubMed1995

Decreased type II/type I TGF-beta receptor ratio in cells derived from human atherosclerotic lesions. Conversion from an antiproliferative to profibrotic response to TGF-beta1.

Atherosclerosis and postangioplasty restenosis may result from abnormal wound healing. The present studies report that normal human smooth muscle cells are growth inhibited by TGF-beta1, a potent wound healing agent, and show little induction of collagen synthesis to TGF-beta1, yet cells grown from human vascular lesions are growth stimulated by TGF-beta1 and markedly increase collagen synthesis. Both cell types increase plasminogen activator inhibitor-1 production, switch actin phenotypes in response to TGF-beta1, and produce similar levels of TGF-beta activity. Membrane cross-linking of 125I-TGF-beta1 indicates that normal human smooth muscle cells express type I, II, and III receptors. The type II receptor is strikingly decreased in lesion cells, with little change in the type I or III receptors. RT-PCR confirmed that the type II TGF-beta1 receptor mRNA is reduced in lesion cells. Transfection of the type II receptor into lesion cells restores the growth inhibitory response to TGF-beta1, implying that signaling remains responsive. Because TGF-beta1 is overexpressed in fibroproliferative vascular lesions, receptor-variant cells would be allowed to grow in a slow, but uncontrolled fashion, while overproducing extracellular matrix components. This TGF-beta1 receptor dysfunction may be relevant for atherosclerosis, restenosis and related fibroproliferative diseases.

Actins↗
PubMed1995

[Experimental research of middle ear implant].

Click and tone burst were used to evoke the auditory brainstem responses of experimental animals. The stimulations of different sound intensities were used. Amplitudes, latencies and thresholds of normal ear were measured and the incus of right ear was removed and Nd-Fe-B middle ear implanted. The thresholds of normal ears were 14.74 +/- 4.12 dB nHL on average. The thresholds of removed incus were 57.00 +/- 8.64 dB nHL on average. The thresholds of the implanted middle ears were 16.25 +/- 8.56 dB nHL. It was found that the characterstics of frequency responses of the implanted middle ear cover the whole area of language frequency in the experiment. It accorded with the features of audibility of human ear.

Animals↗