Biomedical subjects

Y Guo

Publications and source records attributed to Y Guo.

At least 397 records · Page 22Linked to original sources

PubMed1998

[The use of laparoscopy in urology: report of 141 cases].

OBJECTIVE: To modify laparoscopy in urology. METHOD: From May 1992 to Nov. 1996, 141 patients (110 males and 31 females) were subjected to laparoscopy in the treatment of urological diseases. The age of the patients ranged from 9 to 76 years (mean 39 years). Five patients had nephrectomy, 12 adrenalectomy, 48 renal cyst resection, 61 high ligation of internal spermatic vein, 5 pelvic staging lymphadenectomy, 9 orchiectomy, and 1 removal of bladder diverticulum. RESULT: The rate of successful operation was 95.7% and that of complications was 2.22%. The mean hospitalization was 4.9 +/- 4.1 days. CONCLUSION: Laparoscopy can be used widely in clinical practice.

Adolescent↗

PubMed1998

[A monoclonal antibody that reacts with an antigen on both normal and malignant prostate cells].

OBJECTIVE: To study the YDPC--a monoclonal antibody that reacts with an antigen on both normal and malignant prostate cell. METHOD: A murine monoclonal antibody (MAb) designated YDPC was generated by treating the primed spleen cells with leucine methyl ester (LeuOMe) following immunization of mice with prostate cancer cell line PC-3M. RESULT: YDPC reacted uniformly with all adenocarcinomas of the prostate examined. It also reacted with the surface antigen on normal prostate epithelial cells and on cells from benign prostate hyperplasia. YDPC reacted with a limited number of normal tissues including renal tubules, adrenal and sweat gland. In addition, three lymph nodes metastasis and one bladder metastasis were found to be strongly positive, while four transitional cell carcinomas of the prostate negative. Preliminary experiments showed that this antibody does specifically localize to prostate cancer xenografts in nude mice. CONCLUSION: YDPC reacts with a differentiation antigen and this antigen continues to be expressed on all adenocarcinomas of the prostate. This antibody may be useful in the diagnosis of or therapy for prostate cancer.

Adenocarcinoma↗

PubMed1998

[Expression and significance of Fas/APO-1 and bcl-2 protein in renal cell carcinoma].

OBJECTIVE: To investigate the role of Fas/APO-1 and bcl-2 in occurrence and progression of renal cell carcinoma. METHOD: Immunohistochemistry method was used to detect the expression of Fas/APO-1 and bcl-2 protein in 35 cases of renal cell carcinoma tissues and 26 cases of normal renal tissues. RESULT: The expression rate of Fas/APO-1 protein in renal cell carcinoma tissues was 57.14%, significantly lower than that in normal renal tissues (84.62%) (P < 0.05), and the intensity of expression was also lower. The expression rate of bcl-2 protein reached 80.00%, much higher than that in normal renal tissues (53.85%) (P < 0.05). CONCLUSION: Both Fas/APO-1 and bcl-2 take part in the occurrence and progression of renal cell carcinoma.

Adult↗

PubMed1998

[Expression of intercellular adhesion molecules in nasal polyps tissue and its significance].

OBJECTIVE: To study the expression of intercellular adhesion molecule-1/lymphocyte function-associated antigen-1 in nasal polyps tissue and its significance. METHODS: Frozen sections of 9 normal nasal mucosa and 19 nasal polyp samples were studied with immunohistochemical technique and immunohistochemical and MGG dual staining method with ICAM-1 and LFA-1 monoclone antibodies. RESULTS: Expression of ICAM-1 and LFA-1 were stronger in nasal polyps tissue than in the normal nasal mucosa, and there is positive relationship between the expression of ICAM-1 and the expression of LFA-1 on eosinophils. CONCLUSION: High expression of ICAM-1 and LFA-1 in nasal polyps tissue showed that interaction of ICAM-1/LFA-1 may participate in the inflammatory reaction and prompt adhesion and migration of eosinophils. High expression of LFA-1+ on eosinophils may play an important role in the pathogens of nasal polyps.

Adult↗

PubMed1998

[Configuration in solution and activity mechanism studies on the anticancer Fe(II)-pingyangmycin (PYM) complex].

In order to elucidate the micro-configuration and mechanism of anticancer activity of Fe(II)-PYM complex in solution, the coordination of high spin paramagnetic ferrous ion, Fe(II), and Pingyangmycin, (PYM) was studied in D2O solution by using the paramagnetic ion probe principle and PMR technique and compared with the inactive complexes, e.g., Cu(II)-PYM and Fe(III)-PYM. The basic configuration parameter of the complexes were determined. When the pyrimidine methyl proton was close to the central ion, 6.5 x 10(-10) m was taken as standard, the absolute distance between the central ion and other protons or ligand could be calculated. Results showed that, in Fe(III) solution, the proton of pyrimidine methyl and the terminal acyl group of the sugar moiety were closer to the central ion, but other protons were relaxed and the distance was between 7.0 x 10(-10) m and 15 x 10(-10) m. In the case of Fe(II) complex, the distance of the central ion and the ligand group was between 4.91 x 10(-10) m and 8.85 x 10(-10) m. The distinctive structure diversity with those of inactive complexes was observed and the relationship of the activity mechanism was postulated.

Antibiotics, Antineoplastic↗

PubMed1998

[Effects of isorhapotigenin and resveratrol on function of peripheral blood polymorphonuclear leukocytes from rabbits].

In effects of isorhapotigenin and resveratrol on chemotaxis and release of beta-glucuronidase from rabbit peripheral blood polymorphonuclear leukocytes stimulated with formylmethionyl-leucyl-phenyl-phenylalanine (fMLPP) were studied. The optimal concentration of fMLPP for the induction of chemotaxis of polymorphonuclear leukocytes was approximately at 5 x 10(-10) mol.L-1. fMLPP, at the concentration range of 10(-10)-10(-6) mol.L-1, dose-dependently increased the release of beta-glucuronidase from polymorphonuclear leukocytes. Isorhapotigenin and resveratrol both inhibited the chemotaxis of polymorphonuclear leukocytes stimulated with fMLPP(5 x 10(-10) mol.L-1). Isorhapotigenin, at the concentration range of 10(-5)-10(-4) mol.L-1, dose-dependently inhibited the release of beta-glucuronidase from polymorphonuclear leukocytes stimulated with fMLPP(10(-8) mol.L-1). Resveratrol, at the concentrations of 1 x 10(-5) and 3 x 10(-5) mol.L-1, was shown to dose-dependently inhibit beta-glucuronidase release from polymorphonuclear leukocytes stimulated with fMLPP(10(-8) mol.L-1).

Animals↗

PubMed1998

[Studies on chemical constituents of Tinospora hainanesis].

Tinospora hainanesis is a new species of Menispermaceae plant. It is used as folk remedy for joint pain and physical injury. Five compounds were isolated from the vine stalk of Tinospora hainanesis. By spectral analysis and chemical methods, the structures of the compounds were identified as makisterone A (I), 2,3-dimethoxy-9,10-dihydroxy-N-methyltetrahydroproto-berberine quaternary salt (II), palmatine (III), beta-amyrin (IV) and docosyl ferulate (V). II is a new quaternary alkaloid named as haitinosporine. I, IV and V were isolated for the first time from the plants of Tinospora genus.

Berberine Alkaloids↗

PubMed1998

[Application of improved western blot method in diagnosis of cysticercosis].

AIM: To evaluate the diagnostic value of four specific antigens from cDNA of Cysticercus cellulosae. cC1, cC2, and cP1 and cH1 (28 kDa, 18 kDa, 14 kDa and 34 kDa), mixing in equal proportions for the diagnosis of cysticercosis. METHODS: Taking the FP (fusion proteins) as antigen to make IWB (improved Western blot) analysis basing on the detection of antibody responses against FP, and making ELISA/IHA-crude antigen(CA) analysis. They were evaluated comparatively while using 107 infected sera of cysticercosis cases, 40 infected sera of clonorchiasis cases, 24 infected sera of echinococcosis cases and 34 sera of healthy persons. The FP are encoded by cDNAs of beta-galactosidase-specific antigens of Cysticercus cellulosae isolated from the cDNA library. RESULTS: 94(87.9%) sera from 107 cysticercosis cases recognized FP in IWB and could not cross-react with the sera of echinococcosis cases, clonorchiasis cases and healthy persons, the specific rates were 100%, whereas ELISA, IHA using CA were 84.1% and 74.8%, respectively and could cross-react with the sera of echinococcosis cases, the false positive rates were 2.5% and 12.5% respectively; CA-ELISA/IHA could cross-react with the sera of clonorchiasis patients, the false positive rates were 8.3% and 16.7%, respectively; and they could also cross-react with the sera of healthy persons, the false positive rates were 8.8% and 11.8%, respectively. CONCLUSION: The recombinant FP used in the immunodiagnosis of cysticercosis is specific and sensitive.

Animals↗

PubMed1998

[Studies on the basis of molecular biology of the phase change of influenza A(H3N2) viruses].

The analysis of nucleotide sequences on HA1 domain of 35 strains of influenza A(H3N2) virus showed that their HA1 genes all were 984 nucleotides in length coding for a HA1 protein with 328 amino acids and there was not any occurrence of insertion or deletion of nucleotides on HA1 genes among them. The appearance of "O" phase strain of influenza A (H3N2) virus was closely related with substitution at 226 position of amino acid on HA1 protein molecule and the three-dimensional structural change of HA protein. The results in this paper indicated that the positions with multiple changes on HA1 protein molecule located at the top of HA protein, especially at antigenic determinant B site or receptor binding site. These further demonstrated that the substitution of amino acid on HA1 protein molecule was caused mainly by suppress of herd immunity. This study also showed that the position of the cysteine and proline residues on the HA1 protein molecule were conservative and that the glycosylation sites located at N and C terminals, especially at N terminal of the HA1 protein The significance of such a distribute delta of glycosylation sites in the evolution of viral genes and epidemiology still remain unknown.

Amino Acid Sequence↗

PubMed1998

[Seroepidemiologic survey for A/PR/8/34 (H1N1) virus from Chinese residents].

A total of 414 serum specimens were collected from the residents with ages of < or = 20 year old in eight different parts of China for detecting antibody to A/PR/8/34(H1N1) influenza virus with HI test. Of them, 24 had antibody with HI titers > or = 20 to A/PR/8/34(H1N1) virus. These 24 specimens were tested with the same method using A/swine/Iowa/15/30 (H1N1), A/Guangxi/10/94(H1N1) and A/Beijing/53/97(H1N1) viruses. The results showed that except 5 of them had antibody with HI titers 20-40 to A/Beijing/53/97(H1N1) virus, the rest had antibodies with titers < 20 to the viruses for checking test. Therefore, the antibody to A/PR/8/34(H1N1) virus in the tested sera was not caused by cross reaction of antibodies against another H1N1 viruses. The results in this paper also further demonstrated that the A/PR/8/34(H1N1) like virus was circulating in residents in China.

Adolescent↗

PubMed1998

[Genetic characterization of an avian influenza A (H5N1) virus isolated from a sick goose in China].

Genetic analysis of viral HA gene showed that there were 22 nucleotide differences in HA gene between goose and human H5N1 viruses. The sequence analysis of amino acid on viral protein molecules indicated that there were 7 and 9 position differences between goose and human, chicken H5N1 viruses, respectively. All the three viruses share multiple basic amino acids (R-E-R-R-R-K-K-R) at the cleavage site between HA1 and HA2 domain, that is associated with highly pathogenic H5 avian viruses. Except one more glycosylation site located at 156 position in the chicken strain, there were 7 glycosylation sites at same positions in three virus HA protein molecules. The analysis of NA protein molecule indicated that the stalk region which extends from the viral membrane up to amino acid 85, human and chicken viruses had a 19 amino-acid deletion as compared with that of goose virus, while the goose NA gene was closely related to A/Parrot/Ulster/73 (H7N1) virus. Therefore, goose H5N1 virus HA and NA genes were avian in origin and were different from those of human and chicken H5N1 viruses. In our knowledge, this is the first time that the avian H5N1 virus was found causing influenza outbreak in goose. Why was A/Goose/Guangdong/2/96(H5N1) virus virulent for geese? It might be related to the substitution of amino acid located at 138 position near by RBS on HA protein molecule and 19 amino acids insertion on NA protein molecule as compared with those of human and chicken H5N1 viruses.

Amino Acid Sequence↗

PubMed1998

Peripheral nerve and transgene cells transplantation in the treatment of experimental neuropathy of SD rats.

PURPOSE: To observe whether optic nerve can regenerate by peripheral nerve transplantation and GDNF gene transfer. METHODS: Optic nerve was transected about 2 mm posterior to the eye to establish experimental models of optic neuropathy. Sciatic nerve was sutured to the sheath of injury optic nerve by a 10-0 nylon, pcDNA3-GDNF was smeared to the joint and injected to the vitreous cavity. The regenerated retinal ganglion cells axons were observed by HRP. The retina and optic nerve were observed by pathohistological methods. RESULTS: Some retinal ganglion cells with regenerated axons could be seen a week after transplantation with large cell bodies. The cells could be identified by HRP. The regenerated nerve fibers grew to the transplanted sciatic nerve. Then the number of retinal ganglion cells with regenerated axons increased with time going. Only a few regenerated retinal ganglion cells could be seen two months after transplantation. The large retinal ganglion cells were seen to have plenty of cytoplasms and be in an active state under electron microscope. Some nerve fibers could be seen in the joint. Sciatic nerve transplantation combined with GDNF gene therapy could increase the amount of retinal ganglion cells with regenerated axons compared with those without GDNF transgene. CONCLUSIONS: Optic nerve could regenerate by peripheral nerve transplantation and GDNF gene transfer.

Animals↗

PubMed1998

Characterization of glucocorticoid receptor on lymphocytes in Chinese patients with glucocorticoid-induced glaucoma.

PURPOSE: We studied the pathogenesis of glucocorticoid-induced glucoma (GIG) through characterization of glucocorticoid receptor (GR) on lymphocytes in Chinese patients with GIG. METHODS: By radioligand receptor binding followed by Scatchard analysis, the specific binding sites were characterized and quantitated for glucocorticoid receptors on peripheral blood lymphocytes obtained from patients with GIG and the control group. RESULTS: The binding sites we detected were as follows: 12.7 +/- 1.47 x 10(3) receptors per cell with a KD of 3.02 +/- 0.62 nmol/L in patients with GIG, 7.26 +/- 0.45 x 10(3) receptors per cell with a KD of 3.03 +/- 0.56 nmol/L in the control group. The statistical difference of receptors per cell is significant between two groups (p < 0.05), patients with GIG having more GR binding sites, while the difference of Kd is not significant (p > 0.05). CONCLUSION: The preliminary findings suggest that patients with GIG are more sensitive to glucocorticoid and the increase of binding sites of GR may be the receptor and molecular basis of the pathogenesis of GIG.

Adolescent↗

PubMed1998

[The preliminary experiment of gene transfer into cultured rat retinal neural cells].

PURPOSE: To investigate the possibility of gene transfer into retina neural cells. METHODS: pcDNA3-LacZ and pcDNA3-GDNF were transferred into rat retinal neural cells with cationic lipofectin. The gene transfer and expression of GDNF were detected by means of RT-PCR and SDS-PAGE. RESULTS: pcDNA3-LacZ and pcDNA3-GDNF could be transferred into retinal neural cells and the expressive product of GDNF gene, a 32 KD protein band, was detected. CONCLUSION: The preliminary results suggest that LacZ gene could be a marker to identify gene transfer into the target tissue and cells; GDNF gene could be transferred into cultured retinal neural cells of SD rats, and express 32 KD protein.

Animals↗

PubMed1998

[The application of antisense technology in ophthalmology].

The research of gene regulation become more and more important with the advancement of the technology of molecular biology and gene study. Antisense molecules can regulate and modify gene expression. By using antisense technology, antisense RNA or artificial antisense oligonucleotides can be made to inhibit or block the transcription and translation of genes. These molecules are highly specific in gene regulation. The application of antisense technology in ophthalmology is introduced briefly in the review. This may be helpful to the studies in ophthalmic research field.

DNA, Antisense↗

PubMed1998

[Study of soft X-ray radiation in 8-20 nm region from a laser plasma source].

A repetitive-laser-produced-plasma (LPP) soft X-ray source with a pulse repetition rate up to 10 Hz was developed. Spectra ranging from 8 to 20 nm were obtained from plasmas generated respectively by a 100 mJ (lambda = 0.53 microm) and 800 mJ (lambda = 1.06 microm) Nd:YAG laser focused on the following different target materials: C, Mg, Al, Ti, Fe, Cu, Zn, Sn, W, Pb and Bi. The dependence of spectral distribution on the target materials and laser parameters, such as pulsed laser energy, laser focus power density etc. are analyzed. The intensities of the soft X-ray radiation with different atomic numbers are characterized.

English Abstract↗

PubMed1998

A role for amyloid precursor-like protein 2 in corneal epithelial wound healing.

PURPOSE: The authors previously showed that the mRNA encoding the amyloid precursor-like protein 2 (APLP2) was one of several genes with upregulated expression in healing corneal epithelium. To elucidate the physiological role of APLP2 in corneal epithelial cells, the expression, distribution, and posttranslational modification of APLP2 were investigated. METHODS: Alternative splicing was assessed by reverse transcription-polymerase chain reaction; translational expression and posttranslational modification were assessed by chondroitinase digestion and Western blotting. The differential distribution of APLP2 in corneal epithelium was examined by in situ hybridization and immunohistochemical analyses. RESULTS: In rat corneal epithelium, the majority of APLP2 mRNA generated from two alternative splicing sites was found to contain the exon encoding a Kunitz protease inhibitor domain in the first site but to lack the exon encoding a 12-amino acid insert in the second site. The absence of the 12-amino acid insert indicated that APLP2 could be modified by the addition of a chondroitin sulfate (CS) glycosaminoglycan chain. The CS proteoglycan nature of APLP2 was verified by chondroitinase digestion. After wounding, APLP2 mRNA and polypeptides were increased markedly in the basal epithelial cells that were actively migrating. Furthermore, APLP2 was observed in the denuded wound bed immediately adjacent to the leading edge of migratory cells and under the epithelial sheet after wound closure. CONCLUSIONS: The wound-induced, basal-cell-specific APLP2 expression correlates with epithelial cell migration. The spatial and temporal expression of Kunitz protease inhibitor-containing, CS-modified APLP2 in healing corneal epithelium is consistent with its hypothesized role(s) in mediating reorganization of the extracellular matrix and dynamic cell-matrix adhesion during reepithelialization.

Alternative Splicing↗

PubMed1998

Overexpression of transforming growth factor (TGF) beta1 type II receptor restores TGF-beta1 sensitivity and signaling in human prostate cancer cells.

TGF-beta1 is a potent negative regulator of cell growth that transduces signals through interaction with type I and type II receptors that form a heteroduplex. Abnormal expression and mutational alterations of these receptors have recently been shown in several human malignancies. In previous studies, we have demonstrated reduced expression of both types of transforming growth factor (TGF) beta1 receptors in human prostate tumors. In this study, using the human prostate cancer cell line, LNCaP, which is refractory to TGF-beta1 and lacks type II receptor (R-II), we investigated whether overexpression of the R-II receptor can restore sensitivity to the negative growth effects of TGF-beta1. LNCaP cells were transfected with plasmid containing the full length of human TGF-beta R-II receptor cDNA sequence. Stable transfectant clones were selected for R-II mRNA and protein expression by Northern and Western analyses, respectively. The effect of TGF-beta on LNCaP R-II overexpressing clones was examined on the basis of: (a) growth inhibition (cell number); (b) DNA synthesis using the [3H]thymidine incorporation assay; (c) induction of cyclin-dependent-kinase inhibitors, p21WAF-1/Cip1, p27Kip1, and p15; and (d) colony-forming ability in soft agar. Both the cell number and the rate of DNA synthesis of R-II-overexpressing clones were significantly suppressed by exogenous TGF-beta1 in a dose-dependent manner, compared with control cell lines. Treatment of R-II cloned transfectants with TGF-beta1 induced a G1 arrest, which was accompanied by a transient increase in p21WAF-1/Cip1 and p27Kip1 expression at the mRNA and protein level. Furthermore, the LNCaP R-II transfectants analyzed exhibited a markedly reduced colony-forming ability. Our results indicate that overexpression of TGF-beta1 R-II receptor in LNCaP prostate cancer cells caused tumor growth inhibition by restoring the TGF-beta signaling mechanism and TGF-beta1 sensitivity.

Carrier Proteins↗