Search PubMed⌕ Search

Biomedical subjects

S Li

Publications and source records attributed to S Li.

At least 1,099 records · Page 61Linked to original sources
PubMed1997

[Analysis on speciems of serum and urine in 66 cases of early leptospirosis by PCR and biotin-AMPPD hybridization].

We used polymerase chain reaction (PCR) and Biotin-AMPPD hybridization to detect leptospiral DNA in blood and urine samples in 66 patients at the early stage of leptospirosis. The results showed that PCR and Biotin-AMPPD hybridization not only ruled out the non-specific PCR amplification and increased the reliability for clinical specineus of leptospirosis but also raised the detecting sensibility (from 71.3% to 86.1%). The positive rates of PCR resulted from serum and urine showed no statistical difference; therefore urine sample is worthy of application and dissemination for detecting leptospires at the early stage of leptospirosis. Urine sample is easier for one to collect, preserve and has less intervention. The primers G1, G2 are optimal opplication of PCR in epdemic areas in China.

Biotin↗
PubMed1997

[p53 gene mutations in BALB/c 3T3 cells transformed by crocidolite].

This study sought to address the relationship between crocidolite and p53 gene mutation. The mutations of p53 gene in 8 BALB/c 3T3 cell lines transformed by crocidolite were analysed. Altogether 11 exons of the gene from 8 cell lines were detected by PCR-SSCP. 7 alterations were found; 2 of them were located in exon 4-6, and 5 in 9-11. Most of the mutations (5/7) were of one more band than that of wild cell from SSCP, and alterations were randomly scattered among the crocidolite doses groups. The results suggest that the presence of a p53 alteration is not related to the dose of crocidolite used. Besides, p53 mutation may occur in a relatively later period of the growth of the transformed cell lines. The results also showed that the mutations occurred predominantly in exons 9-11. This was different from that seen in human mesothelioma where mutations in the exon 5-8 of p53 gene were more frequently observed.

3T3 Cells↗
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

[Construction of genomic library of L. interrogans serovar lai using lambda gt11 as the vector and a study of recombiant plasmid pDL121].

A genomic library of L. interrogans serovar lai strain 017 has been constructed using lambda gt11 as the vector. DNA was partially digested by two blunt-end restriction enzymes, then methylated with EcoR I methylase; after EcoR I linker was added to the DNA, the linker-ended DNA was ligated to the dephosphorylated EcoR I digested lambda gt11 arms. The recombined DNA was packaged in vitro, and used to transduct E. coli Y1090 for amplification. There were 2.1 x 10(6) recombinant bacteriophages as recognized by their ability to form white plaques plated on Lac host in the presence of both IPTG and X-Ga1. A positive clone, designated lambda DL12, was screened with a rabbit anti-serum against L. interrogans serovar lai from the genomic library. The DNA from lambda DL12 was subcloned into plasmid pUC18. A recombinant (designated as pDL121) was obtained. SDS-PAGE analysis indicated that a 23 kd was expressed in E. coli JM 103 harboring pDL121. Western blotting analysis showed that a specific protein band molecular weight of 23 kd could be recognized by the rabbit antiserum against L. interrogans serovar lai strain 017.

Cloning, Molecular↗
PubMed1997

[On the mechanism of hemilaryngeal fixation in pyriform sinus carcinoma and its clinical significance].

To approach the mechanism of hemilaryngeal fixation in pyriform sinus carcinoma (PSC), surgical specimens from total laryngectomy and partial hypopharyngectomy in 43 cases of pyriform sinus carcinoma were studied using organ subserial sections. Invasion of intralaryngeal muscles and the upper and outer aspects of arytenoid cartilage via paraglottic space was found to be the main cause of hemilaryngeal fixation in these cases. Presence of tumor on the medial wall of the pyriform sinus makes involvement of intralaryngeal structures easy, and thus is more frequently seen with hemilaryngeal fixation. Clinical T3 lesion of the sinus may infiltrate laryngeal cartilages and adjacent soft tissue to become pathologic T4 lesion. For PSC appearing hemilaryngeal fixation, total laryngectomy is safer to thoroughly remove cancer.

Adult↗
PubMed1997

[Voice rehabilitation with double-valve voice prosthesis after laryngectomy].

Between March 1993 and November 1996, 97 laryngectomized patients underwent voice rehabilitation with prostheses designed by ourselves. Of these patients, 84 were males and 13 females. The age ranged from 35 to 78 years. 20 cases had the prosthesis inserted during the laryngectomy operation (first stage), while other 77 cases were inserted after the laryngectomies (second stage). The results showed that all of the patients had clear voice with their own local dialect. 34 of them could even sing songs. 68 cases had been followed-up for 2 years. All could speak during the effective time of the prosthesis and no misswallow occurred.

Adult↗
PubMed1997

[Immunohistochemical study of c-erbB-2 and p53 protein in breast papillomatosis and its malignant transformation].

OBJECTIVE: To evaluate the levels of c-erbB-2 and p53 protein in different stages of papillomatosis of breast and its malignant transformation and value for early diagnosis. METHODS: Levels of c-erbB-2 and p53 protein were detected by immunohistochemistry in 184 paraffin-embeded blocks. RESULTS: c-erbB-2 protein expression was seen in all stages of papillomatosis with different degrees of proliferation and in tissues undergone malignant transformation. The rate of overexpression increased with the degree of proliferation. The p53 protein expression was not found in papillomatosis with mild to severe proliferation. It was only overexpressed in 3.5% of carcinoma arising from papillomatosis, but increased to 25% when invasion occurred. CONCLUSION: c-erbB-2 assay may be helpful for detection of early malignant change of the highly proliferative papillomatosis, especially when histopathological evidence of malignancy is still lacking. p53 protein is of no significant diagnostic value in these lesions.

Breast Neoplasms↗
PubMed1997

[Pathological study of en bloc breast sections in papillomatosis and its malignant transformation].

OBJECTIVE: To investigate the characteristics of breast papillomatosis, its malignant transformation and relation with main ductal papilloma. METHODS: A histopathological study by en bloc breast subserial sections was performed on 14 cases of highly proliferative papillomatosis and 22 cases of carcinoma arising from the highly proliferative papillomatosis. RESULTS: The two types of lesions were widely scattered over the sections, covering more than two quadrants in 71.4% (10/14) and 63.3% (14/22) of the breast, respectively. Crisscross and histological transition of the two lesions were observed frequently in the sections of carcinoma arising from the highly proliferative papillomatosis. These two kinds of lesion often coexisted with main ductal papilloma. CONCLUSION: Papillomatosis is a breast precancerous lesion and it may have similar pathogenetic mechanism as main ductal papilloma.

Breast Neoplasms↗
PubMed1997

[Analysis of malate dehydrogenase isozymes in Taihe negro fowl by thin-layer isoelectric focusing polyacrylamide gel electrophoresis].

The isozyme patterns of malate dehydrogenase (MDH) from six tissues (liver, kidney, eye, muscle, brain and heart) of the Taihe negro fowl (Gallus gallus domesticus Brission) were analysed by thin-layer isoelectric focusing polyacrylamide gel electrophoresis. It was found that there were twelve MDH isozyme bands in the tissues of the fowl, and these isozymes displayed a tissue-specific distribution.

Animals↗
PubMed1997

[Ultrastructural morphological observation on the plasma cells in periodontitis-affected human gingival tissue].

The transmission electron microscope was used to demonstrate the mechanism of immunoreaction in periodontitis-affected gingival tissue. The result showed that the number of plasma cells (PC) was the highest in infiltrated inflammatory cells and with degeneration. According to the variation of ultrastructural features of nuclei; plasma membrane (PM) and cisternae (Ci) of rough endoplasmic reticulum (RER), PC were classified into 4 stages. The chromatin of their nuclei varied from normal, to marginal concentrated, pyknosis, and karyorrhexis. The PM appeared intact, partial loss, to complete loss. The Cisternae showed varying degree of dilatation and the RER was broken into numerous discrete vesicles. The electron density of cisternae varied from low to high, and again low. The number of Russell's bodies varied from rare to increase, and then rare again. At last degenerated PC underwent apoptosis. The results show that the adult periodontitis is related to humoral immunity.

Adult↗
PubMed1997

Cellular response and membrane formation on the surface of implanted posterior chamber intraocular lens in rabbit.

PURPOSE: In order to study the cellular response and membrane formation on the surface of intraocular lens after cataract surgery and lens implantation, this study was designed to observe the deposits on the surface of implanted posterior chamber intraocular lens (PC-IOL) for 4, 7, 15, 30 and 90 days in rabbits. METHODS: 30 rabbits had undergone ECCE with PC-IOL implantation. PC-IOLs were removed at different stages after operation. 20 PC-IOLs were stained by HE to demonstrate cells on the surface of PC-IOL under light microscopy. 5 PC-IOLs for scanning electron microscopy were observed. 5 membranes were studied by transmission electron microscopy. RESULTS: On 25 implanted PC-IOLs, the incidence of cell adhesion was 100%. The cells adherent to lens included macrophages, fibroblast-like cells, epithelioid cells, giant cells, ultralarge giant cells and lymphocytes. It was seen that there was a thin proteinaceous film on the surface of the implanted PC-IOLs and the membrane was composed of fibrin collagen fibrils, macrophages, fibroblast-like cells, giant cells and fibroblasts. CONCLUSION: The cellular response on the surface of implanted PC-IOL is a chronic foreign-body inflammatory reaction and the membrane on the surface of implanted PC-IOL is a reactive membrane of the foreign-body. However, the reaction described in this study might be applicable to human since cellular elements and membranes have been frequently reported finding in human.

Animals↗
PubMed1997

Non-trans-scleral suture fixation of posterior chamber intraocular lenses in the absence of posterior capsular support.

PURPOSE: To develop a new technique for fixation of posterior chamber intraocular lens (IOL) in the absence of posterior capsule support. MATERIALS AND METHODS: We performed non-trans-scleral fixation of intraocular lenses on 24 cases (24 eyes) without posterior capsule support. Two scleral flaps with limbal incisions and two peripheral iridectomies were made at 1 o'clock and 7 o'clock positions respectively. A suture-leading needle was used to lead the prolene suture from the limbal incision and iridectomy on one side through the iridectomy and limbal incision on the other side. Intraocular lens (IOL) was then fixed in the ciliary sulcus. RESULTS: After a mean follow-up of 6.6 months (range from 3 to 14 months), corrected visual acuity of 16 cases (16 eyes, 66.7%) got 0.5 or better. Postoperative complications included discoria (4 eyes), surface membrane formation (1 eye), choroidal detachment (1 eye) and tilt of IOL (1 eyes), but all were not severe. CONCLUSION: In some situations such as low intraocular pressure, non-penetration scleral fixation may be a good way to implant IOL in the absence of posterior capsule support.

Adolescent↗
PubMed1997

Exon-by-exon screening for RB germline mutations using Heteroduplex-SSCP analysis.

OBJECTIVE: To disclose the nature of RB1 germline mutations in Chinese and to develop a practical and effective way for mutational screening. METHODS: Leukocyte DNA was prepared from 8 Chinese patients with hereditary retinoblastoma. PCR combined with nonisotopic heteroduplex-SSCP analysis was used to screen leukocyte DNA for RB1 germline mutations, exon-by-exon, without the use of restriction endonuclease digestion. The mutations were finally identified by sequencing. In order to testify the effectiveness of this method, the same method was used to detect other 17 samples which have been previously analyzed by other methods. RESULTS: Heterozygous germline mutations were detected in the leukocyte DNA of 6 out of 8 Chinese patients: G del/codon 46, T del/codon 131, CAGAA del/codon 257-258, GCAgta-->GCAgca/donor of exon 16, C-->T/codon 661, and C-->T/codon 787. Heteroduplex-SSCP analysis may detect RB1 germline mutations in 68% (17/25) unselected patients, which is more effective than SSCP(56%) or heteroduplex analysis(64%) alone. The corrected RB1 mutation detection rate may be 80% if the samples were previously analyzed by Southern blotting, which is much higher than those reported on literature. CONCLUSION: Mutations involving a few base pairs in RB1 gene are common in Chinese. Heteroduplex-SSCP analysis is more useful and effective than SSCP or heteroduplex analysis alone for the rapid screening for unknown mutations.

Female↗
PubMed1997

[Vision change and quality of life in the patients with cataract].

PURPOSE: We tried to assess the relationship between quality of life and visual impairment and restoring of patients with cataract and explore the factors which affect quality of life of patients with cataract. METHODS: The 142 cases of cataract with different visual impairment and the 33 cases of cataract prior to surgery and at 3 months after cataract extraction and intraocular lens implantation were measured by the scale of quality of life for diseases with visual impairment. RESULTS: The scores of quality of life and their subscores were significantly associated with the visual acuity of patients with cataract. The scores of quality of life between preoperation and after surgery had significantly difference. The factors which affect quality of life of patients with cataract included visual impairment, age and occupations. CONCLUSION: Visual impairment that caused by cataract would cause decline in quality of life. Cataract surgery was effective in improving visual acuity and quality of life of the patients. Measuring quality of life would afford a new method for evaluating visual impairment of cataract.

Adolescent↗
PubMed1997

PCR amplification, molecular cloning, DNA sequence analysis and immuno/protection in BALB/C mice of the 33 kDa endoflagellar protein of L. interrorgans serovar lai.

A pair of oligonucleotide primers were designed to amplify the endoflagella gene of L. interrogans serovar lai. An approximately 840 bp fragment was generated with PCR and inserted into plasmid pUC8, after the fragment and pUC8 were digested respectively with BamHI and PstI. A recombinant plasmid (designated as pLF1) was obtained. SDS-PAGE analysis indicated that a 33 kDa was expressed in E. coli JM103 harboring pLF1 and the expression level of the protein was 11% of the total bacterial soluble proteins. Western blot analysis showed that the protein band could be recognized by the antiserum against the endoflegella (Axial filament) of Leptospira interrogans serover lai. Nucleotide sequence data showed an open reading frame encoding 282 aminoacids residues, corresponding to a protein of molecular weight 33.6 kDa. Comparison of the deduced endoflagellar subunit protein (flaB) amino acid sequence with flagellins from other bacteria revealed a high level of identity with the Treponema pallidum flaB proteins. Immunization/protection experiment was performed on the model of BALB/C mice and showed that there was higher survival rate in the group JM103-pLE1 than in the group JM103-pUC8.

Amino Acid Sequence↗
PubMed1997

The clinical analysis of hypnotics and sedatives used in outpatient clinics in general hospital.

AIM: To statistic the usage of hypnotics and sedatives in outpatient and emergency clinics prescriptions in one day. METHOD: Check all prescriptions on April 29, 1987 and November 13, 1995 in order to know the quantity, kind and distribution of hypnotics and sedatives in different outpatient departments. RESULT: There were 1,319 prescriptions on April 29, 1987. Among them, hypnotics and sedatives were 122(9.24%); in comparing with 2,065 prescriptions on November 13, 1995, hypnotics and sedatives were 141 (6.82%). Benzodiazepine used more than 80% in all prescriptions. CONCLUSION: The possibility of long-term low-dosage using benzodiazepine is present. It must strengthen the control and education to avoid the drug-abuse.

Benzodiazepines↗
PubMed1997

Suppression of malignant phenotype of a transformed mouse mammary epithelial cell line (11A1) by tumor suppressor gene RB.

A malignant transformed mammary epithelial cell line (11A1) was transfected with liposome encapsulated eukaryotic expression plasmid pCMV-neo-RB, yielding 4 constant clones which have obvious phenotypic reversion changes, and named 11A1-R1-R4 respectively. Further experiments showed that the 11A1-R1 behaved like normal epithelial cells in both morphological and biological characteristics, with decreased clonogenicity in solid argar medium as well as decreased tumorigenicity. Northern blot hybridization showed increased expression of RB gene and decreased expression of c-myc gene in 11A1-R1, 11A1-R2 cells compared to 11A1 cells. This was an ideal phenotypic reversion model for epithelial transformed cell line and demonstrated that the RB gene can reexpress and suppress malignant phenotype in RB inactive cells.

Animals↗