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Biomedical subjects

Y Deng

Publications and source records attributed to Y Deng.

At least 163 records · Page 9Linked to original sources
PubMed1997

[Construction of human genomic YAC clones with "terminal modification"].

A human YAC genomic pool with more than 4,000 clones was constructed by means of "terminal modification" of YAC vector and genomic inserts, as well as optimization of relevant experimental parameters. The transformation rate is approximately 400-500 transformants per microgram DNA. Preliminary characterization of randomly sampled clones demonstrates that YAC-specific inserts, in the average size of 450 kb and ranging 150-750 kb, were detected from 80% of the clones. The vector ligation experiment indicates the efficient reduction of "coligation" by terminal modification.

Chromosomes, Artificial, Yeast↗
PubMed1997

[Immunobiological significance of S-100 protein positive dendritic cells (S-100+DC) in patients with oral squamous cell carcinoma].

The purpose of this study is to investigate the role and clinical significance of S-100+DC in oral squamous cell carcinoma. Distribution of S-100+DC in the tumor tissues and regional lymph nodes (LN) of 60 patients with oral squamous cell carcinoma was detected by immunohistochemistry (ABC). The results showed that the S-100+DC density in tumor tissues was correlated with the tumor histologic grade (P < 0.05). The density of S-100+DC was significantly higher in regional LN without tumor than those with metastases (P < 0.05). However, there was no difference of S-100+DC in tumor tissues between patients with and without regional LN metastases. The distribution of S-100+DC in tumor tissues and regional LN could be considered as a reference indicator of tumor histologic grade and clinical prognosis of patients.

Adult↗
PubMed1997

[A three-month follow-up study of excimer laser photorefractive keratectomy for myopia].

In order to evaluate the efficacy of photorefractive keratectomy (PRK) in the treatment of myopia, we summed up and analysed the 3-month follow-up data on 145 cases treated in our hospital. Prior to PRK, refractive dioptal was -1.5 to -11.5; visual acuity was less than 0.1 in 137 cases (94%) and less than 0.5 in 8 cases(6%). One month after operation, the mean refractive dioptal was +0.98 +/- 0.88; visual acuity increased to > or = 1.0 in 95 cases (66%) and to > or = 0.5 in 142 cases(98%). Three months after operation, the mean refractive dioptal was -0.13 +/- 1.09; visual acuity increased to > or = 1.0 in 104 cases(72%) and to > or = 0.5 in 135 cases(93%). There was no severe complication noted in all cases. The results demonstrate that PRK is and effective, safe and predictable treatment for myopia.

Adolescent↗
PubMed1997

[Long-term effects of stapes elevation].

To assess the clinical value of stapes elevation, 38 cases had been followed-up for 1-12 years (average 6.7 years). The results revealed that hearing improvement rate (over 10 dB) was 94.7% in short term and 86.8% in long term follow-up. The long term regression rate was similar to that in stapedectomy, and no severe sensorineural hearing loss occurred. In addition, the vestibular reaction was slight, especially in reoperated cases. The stapes elevation was easy to perform as compared with stapedectomy. Therefore, this technique may be the first choice for stapes surgery.

Adolescent↗
PubMed1997

[Clinical and pathological observation of recurrent nasal polyp formation].

To investigate the mechanism of nasal polyp recurrence, 19 patients with recurrent nasal polyp were retrospectively analysed. In 4 patients, nasal polyp specimens had been sent for pathological examination more than three times, and in 6 patients, bacteria culture was performed. There were two types of recurrent nasal polyp: water-cyst type (fast recurrence) and edematous granulation type (slow recurrence). Both types were the result of inflammatory reaction, perhaps related to trauma of operation. Water-cyst formation indicated stronger inflammatory reaction. During follow-up, 10 patients were cured and 9 recurred. Preventive measures against nasal polyp recurrence were discussed.

Adult↗
PubMed1997

[Expression of Epstein-Barr virus latent membrane protein (EBV-LMP) in human laryngeal carcinoma].

In order to investigate the expression of Epstein-Barr virus in human laryngeal carcinoma, immunohistochemical study for Epstein-Barr virus latent membrane protein (EBV LMP) was performed on 90 laryngeal specimens taken from laryngeal carcinoma patients. The results showed that LMP was localized on the cell membrane and in cytoplasm. LMP was detected in 41 of 90 (45.5%) laryngeal squamous cell carcinoma, among them the positive rates of poorly differentiated, middle differentiated and well differentiated squamous carcinoma were 44% (12/27), 52% (25/47) and 26.6% (4/15) respectively. This study indicated that EB virus was not only presented in poorly differentiated carcinoma, it was also presented in well differentiated carcinoma. The development of laryngeal squamous carcinoma is related to the infection of EB virus.

Adult↗
PubMed1997

[Transduction of antisense RNA of MHC-II gene into CD3+ cord blood stem/progenitor cells inhibits the expression of HLA-DR antigen].

OBJECTIVE: To explore whether the antisense RNA of HLA-DR gene could modulate the expression of the gene and reduce the immunogenicity of cord blood (CB) cells. METHODS: A retroviral vector encoding antisense RNA of HLA-DR gene was constructed and transducted into packaging cell line PA317 by lipofectin. CD34+ hematopoietic stem cells/progenitors were sorted and enriched by MACS. RESULTS: A high titer (1 x 1095) cfu/ml) helper-free,virus producing cell PA317 was obtained. The vector was identified by blot hybridization and mapping of restriction points. The CD3+ CB cells were infected by the supernatant of the viral cultures. The G418-resistant clone was demonstrated to express the antisense RNA of HLA-DR gene by RT-PCR technique. The expression rate of HLA-DR antigen on CB cells was 28%, which was apparently lower than that of the control (45%) with an inhibition rate of 38.25%. CONCLUSION: The introduction of antisense RNA of HLA-DR gene into CB hematopoietic stem cells can successfully decrease the expression of HLA-DR antigen. These studies provide evidences for the prevention and treatment of GVHR in clinical CB transplantation.

Animals↗
PubMed1997

Extremely low awareness of AIDS, sexually transmitted diseases and condoms among Dai ethnic villagers in Yunnan province, China.

OBJECTIVE: To assess the awareness of AIDS, other sexually transmitted diseases (STDs), condoms, sources of health information and HIV-related societal risks among Dai villagers in southern Yunnan Province, China. SUBJECTS AND METHODS: In November-December 1994, a cross-sectional descriptive study, comprising a questionnaire-based survey and focus group discussions, was conducted in three Dai villages in Mengla county; a total of 177 Dai villagers were interviewed in the survey and eight focus group discussions were held. Ethnographic observations provided a composite picture of HIV risks in the area. RESULTS: Only 18% of respondents had heard of AIDS, and only 25 and 28%, respectively, had heard of STDs or condoms. Furthermore, among these more aware groups, the level of knowledge was low and misconceptions were common. An ability to understand the official language (Mandarin) was the most important predictor of awareness of AIDS, other STDs or condoms. The sources of information in the three Dai villages sampled included TV, videos, radio and magazines, but only TV and videos had a large audience. Even so, these media were mostly in Mandarin and were not used in AIDS education. Travel outside of China was frequent; most villagers (77%) had traveled to Laos and 9% had traveled to Thailand. Societal risks of HIV transmission, such as an increasing incidence of STDs and an active sex industry, were observed in this area. CONCLUSIONS: Dai villagers in southern Yunnan Province had an extremely low awareness and knowledge of AIDS, other STDs and condoms. Given the high mobility of ethnic villagers to neighboring countries in Southeast Asia and the societal risks of HIV transmission in this area, there is an urgent need to provide accessible education about AIDS and other STDs. Suggestions regarding such health education and the implications of HIV policy-making are discussed.

Acquired Immunodeficiency Syndrome↗
PubMed1997

[Effects of glycated protein on the expression of plasminogen activator inhibitor-1 of cultured human mesangial cells].

OBJECTIVE: To investigate whether nonenzymatic glycated end products (AGEs) have effects on the expression and bioactivity of plasminogen activator inhibitor-1 (PAI-1), one of the seripin proteinases, which lead to extracellular matrix (ECM) degradation in cultured human mesangial cells. METHODS: Human mesangial cells (HMC) were cultured. Cell proliferation, fibronectin production, mRNA expression and bioactivity of PAI-1 were determined after exposure to AGE-BSA for 24 hours and 48 hours in vitro. RESULTS: HMC stimulated by AGE-BSA exhibited inhibition in HMC proliferation, increase in fibronectin production, and PAI-1 bioactivity. These changes were pronounced with prolongation of experimental time. PAI-1 mRNA expression increased significantly at 24 hr (0.45% +/- 0.06% vs 0.65% +/- 0.08%, P < 0.05), however more marked increase of PAI-1 mRNA expression at 48 hr (0.51 +/- 0.08% vs 0.92 +/- 0.10%, P < 0.01). CONCLUSIONS: Increase of mRNA expression and bioactivity of PAI-1 induced by AGEs decreased ECM degradation and play an important role in the pathogenesis of ECM accumulation and glomerulosclerosis.

Cell Division↗
PubMed1996

Mechanism of enantioseparation of salsolinols, endogenous neurotoxins in human brain, with ion-pair chromatography using beta-cyclodextrin as a mobile phase additive.

A novel method for direct separation of the enantiomers of salsolinol and N-methylsalsolinol was devised. The enantiomers were completely separated with ion-pair chromatography on a reversed-phase column with beta-cyclodextrin as a chiral mobile phase additive and sodium 1-heptanesulfonate as a counterion. The mechanism for enantioseparation with this ion-pair system containing beta-cyclodextrin was discussed. The effects of beta-cyclodextrin, counterions, pH, ionic strength, and organic solvent on retention were investigated, and a retention model was proposed and proved to be consistent with the experimental data. A preliminary study of the enantiomeric composition of salsolinol and N-methylsalsolinol in banana and in human brain was made as an example of the application of this assay.

Brain Chemistry↗
PubMed1996

Intravenous somatic gene transfer with antisense tissue factor restores blood flow by reducing tumor necrosis factor-induced tissue factor expression and fibrin deposition in mouse meth-A sarcoma.

Fibrin is deposited on the endothelial cell surface in the vasculature of murine methylcholanthrene A-induced sarcomas after injection of tumor necrosis factor (TNF). Capillary endothelial cells of the tumor vascular bed become positive for tissue factor after TNF injection, based on immunocytochemistry and in situ hybridization. Intravascular clot formation was not dependent on tissue factor derived from tumor cells, since in vessels of tumors not expressing tissue factor, TNF also induced fibrin/fibrinogen deposition. However, the time course of fibrin/fibrinogen deposition after TNF differed in tumors expressing no, little, or greater amounts of tissue factor. Fibrin/fibrinogen deposition was more rapid in tumors in which the neoplastic cells expressed tissue factor than in tumors not expressing tissue factor. In the tumors not expressing tissue factor, activation of coagulation was dependent on TNF-induced synthesis of tissue factor by host cells, i.e., endothelium or monocytes/macrophages. Intravenous somatic gene transfer with tissue factor cDNA in the antisense orientation (but not sense or vector alone) reduced intravascular fibrin/fibrinogen deposition and restored blood flow to the tumor, showing that de novo tissue factor expression is central in TNF-induced activation of the coagulation mechanism.

Animals↗
PubMed1996

Influence of atrial natriuretic factor on fluid efflux from the splenic circulation of the rat.

1. Atrial natriuretic factor (ANF) causes a reduction in plasma volume that is abolished by splenectomy. Experiments were conceived to investigate whether ANF acts within the spleen to increase efflux of fluid from the intravascular to the extravascular space. 2. ANF, infused into the splenic artery of anaesthetized rats at rates of 1, 5 and 20 ng min -1, caused a dose-dependent increase in the arteriovenous difference in haematocrit as blood flowed through the spleen (basal difference, 0.18 +/- 0.10%; difference after 10 min at 20 ng min -1 ANF, 1.5 +/- 0.18%; n = 6). There was no such change in plasma protein concentration. 3. ANF (20 ng min -1) did not alter splenic arterial blood flow. However, splenic venous blood flow fell so that the arteriovenous difference increased significantly (basal difference, 0.34 +/- 0.19 ml min -1; difference at 60 min, 1.1 +/- 0.20 ml min-1, n = 7). There was no change in mean arterial pressure. 4. These data confirm our hypothesis that ANF acts within the spleen to increase fluid efflux from the intravascular to the extravascular space. Since there is no change in total splenic blood flow, we propose that the effects of ANF are mediated by dilatation of the splenic afferent arterioles and constriction of the efferent venules, thus increasing filtration pressure.

Animals↗
PubMed1996

The VP3 gene of human group C rotavirus.

The complete nucleotide sequence of genome segment 4 from the human group C rotavirus (Bristol strain) was determined. Comparison of the nucleotide sequences of the genome termini with the consensus 5' and 3' terminal non-coding sequences of the human group C rotavirus genome revealed characteristic 5' and 3' sequence motifs. Human group C rotavirus genome segment 4 is 2,166bp long and encodes a single open reading frame of 2,082 nucleotides (693 amino acids) starting at nucleotide 55 and terminating at nucleotide 2,136 giving a 3' untranslated region of 30 nucleotides. Alignment with the porcine group C VP3 equivalent gene showed the human gene is one amino acid longer, and that the proteins have 84.1% amino acid sequence identity. A conserved potential nucleotide binding motif shared with the porcine VP3 sequence was identified. Analogy with the group A rotaviruses suggested that the genome segment 4 encodes the group C rotavirus guanylyltransferase.

Amino Acid Sequence↗
PubMed1996

Release of thrombomodulin from endothelial cells by concerted action of TNF-alpha and neutrophils: in vivo and in vitro studies.

Inflammatory cytokines decrease the expression of thrombomodulin (TM) on the endothelial cell surface by suppression of TM transcription and translation or internalization with subsequent degradation. Nevertheless, elevated serum TM levels are found in diseases associated with systemical or locally increased levels of inflammatory cytokines. To study directly the in vivo effects of tumour necrosis factor-alpha (TNF-alpha) we determined the course of serum TM after systemic recombinant human (rh)TNF-alpha therapy. The TM levels were determined by enzyme-linked immunosorbent assay (ELISA). Systemic rhTNF-alpha therapy resulted in a marked and significant increase of serum TM. Using a mouse model we studied whether increased serum TM is associated with a decreased expression of TM on the endothelial surface in vivo. The immunohistochemical staining of the vasculature of meth-A sarcoma transplanted in mice showed a loss of TM immunoreactivity 4 hr after intravenous TNF-alpha application. To study the mechanism of TNF-alpha mediated release of TM, cultured endothelial cells were incubated with neutrophils and TNF-alpha. Incubation with TNF-alpha alone did not lead to an increase of TM in vitro. However TM was released into the culture supernatant when endothelial cells pretreated with TNF-alpha were exposed to neutrophils. This was associated with morphological evidence of endothelial cell damage. Therefore, the concerted action of cytokine-stimulated endothelial cells and neutrophils results in release of TM from cultured endothelial cells after rhTNF-alpha therapy. This might explain the increased serum TM levels observed in diseases associated with increased systemic or local levels of inflammatory cytokines despite the induced internalization and the direct inhibitory effects of TNF-alpha on TM transcription and translation.

Adult↗
PubMed1996

[The expression of bcl-2, P53 and c-erbB-2 onco-proteins in breast cancer and their clinicopathological significance].

In order to study the interrelation between bcl-2, P53 and c-erbB-2 protein, their expression in 145 breast carcinomas were observed by immunohistochemical LSAB method. 19 cases were negative, 12 were positive for the three oncoproteins. 19 cases were positive for c-erbB-2 only. 20 positive for P53 only and 20 positive for bcl-2 only. 26 cases were positive for both P53 and c-erbB-2, 17 for both c-erbB-2 and bcl-2, 12 for both P53 and bcl-2. Strong inverse correlation was found between the expression of P53 and bcl-2 (P < 0.001). The P53 expression or the expression of both P53 and c-erbB-2 correlated with low histological grade, while the bcl-2 expression correlated with high histological grade (P < 0.05). The necrosis in tumors with only bcl-2 expression was less than those with c-erbB-2 or both c-erbB-2 and P53 expression (P < 0.02). Mitosis count was lower in tumors with only bcl-2 expression than those with expression of both c-erbB-2 and P53 (P < 0.05). The expression of c-erbB-2 and P53 proteins are associated with poor prognosis (P < 0.02, P < 0.05) but not affected by bcl-2. The results suggest that bcl-2, P53 and c-erbB-2 are involved in tumorigenesis and development of breast carcinoma with different biological effects.

Adult↗
PubMed1996

[Effects of electroacupuncture on the subcutaneous mast cells of zusanli acupoint in rat with unilateral sciatic nerve transection].

Electroacupuncture could induce the convergence and degranulation of subcutaneous mast cells in acupoints. After unilateral transection of sciatic nerve, we studied the numbers of subcutaneous mast cells and its degranulation in bilateral Zusanli and Xiajuxu acupoints with electroacupuncture in Zusanli. We found that sciatic nerve transection could reduce the total numbers of mast cells and the degranulation numbers of mast cells in Zusanli. The results suggested peripheral nerves play an important role in the convergence and degranulation of mast cells in acupoints by electroacupuncture induction.

Acupuncture Points↗
PubMed1996

[The influence of electroacupuncture on the mast cells in the acupoints of the stomach meridian].

Giving electroacupuncture at unilateral "Biguan" and "Zusanli" points, we observed the rat subcutaneous mast cells of "Tianshu", "Biguan", "Futu", "Zusanli" and "Xiajuxu" acupoints in bilateral Stamach Meridian. It was found that the numbers of mast cells in all the acupoints studied were higher than that in the non acupoint area. The numbers of mast cell in acupoints were increased under electroacupuncture, while that in non acupoint area was not changed. The results suggested the mast cells play an important role in the functions of the Meridian.

Acupuncture Points↗