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Biomedical subjects

Li Li

Publications and source records attributed to Li Li.

At least 667 records · Page 37Linked to original sources
PubMed2002

[Laparoscopic total mesorectal excision for low or ultralow anterior resection of rectal cancer with anal sphincter preservation].

OBJECTIVE: To assess the feasibility of laparoscopic total mesorectal excision (TME) for low or ultralow anterior resection of rectal cancer. METHODS: Excision of the mesorectum and low (ultralow) colo-anal anastomoses were performed laparoscopically in 62 patients with low rectal cancer based on the concept of TME and double stapling technique (DST). RESULTS: Sixty-two operations with TME and DST were performed in a totally laparoscopic manner, and only one was converted to open procedures because of dysfunction of coagulation. The operative time was 125 min (110-210 min) and the operative blood loss 20 ml (5-80 ml). The time for bowel function recovery and post-operatively dietary intake was 1-2 days. Twenty-eight patients received postoperative analgesics. Average hospital stay was 8 days (5-14 days). Complications were observed in only 2 of the 62 patients, one had suffered from urinary retention and the other, anastomotic leakage. CONCLUSIONS: Totally laparoscopic excision of the mesorectum for low or ultralow anterior resection of rectal cancer is a minimally invasive technique with sphincter preservation, less postoperative pain, and rapid recovery.

Adult↗
PubMed2002

[Screening and cloning gene of hepatocyte protein interacting with hepatitis C virus core protein].

OBJECTIVE: To clone the unknown gene of hepatocyte protein interacting with hepatitis C virus core protein. METHODS: Using the yeast dual hybrid system 3, bait plasmids of hepatitis C virus core were constructed. After identifying hepatitis C virus core protein that could stably expressed in AH109 yeast strains, we performed yeast two hybrid by mating AH109 with Y187 that transformed with liver cDNA library plasmids pACT2 and then plated on quadrople dropout (QDO) medium and assayed for alpha-gal activity. The genes of yeast colonies that could grow on QDO and had alpha-gal activity were sequenced. RESULTS: Among the 30 positive colonies, we blasted the gene of the sixth colony; we coined human hepatitis C virus binding protein 6(Hu Hcbp6) with Genbank, realized that the Hu Hcbp6 shares as much as 98% homology with two cDNA without knowing functions. We have proved that Hu Hcbp6 could interact with hepatitis C virus core protein. CONCLUSIONS: Hepatitis C virus core binding protein (Hu Hcbp 6 Genbank number: AY032594) was successfully cloned and identified. The study partly paved the way for investigating physiological function of the Hu Hcbp6.

Cloning, Molecular↗
PubMed2002

[Famciclovir treatment of patients with chronic hepatitis B virus infection].

OBJECTIVE: To evaluate the effects of famciclovir treatment of patients with chronic hepatitis B virus (HBV) infection. METHODS: Eighty-nine patients with chronic HBV infection were randomly divided into three groups. Thirty-two patients were treated with famciclovir, 29 patients and 28 patients with chronic HBV infection were treated with interferon (IFN) alpha and lamivudine, respectively, as the control. RESULTS: The serum HBV DNA became negative after treatment in 40.62% (13/32) of patients treated with famciclovir, 37.93% (11/29) of patients treated with IFN alpha, and 67.90% (19/28) of patients treated with lamivudine. The rate of serum HBeAg loss for the three groups were 21.88% (7/32), 41.38% (12/29) and 21.43% (6/28), respectively. The average time for patients to become serum HBV DNA negative was 1.3 months. CONCLUSIONS: Famciclovir is an effective and safe nucleoside drug for the treatment of patients with chronic HBV infection.

2-Aminopurine↗
PubMed2002

[Screening and application of human-derived HBsAg bacteriophage single chain antibody in clinical diagnosis].

OBJECTIVE: To identify human single chain Fv antibody (ScFv) against hepatitis B viral surface antigen. METHODS: The recombinant phages were panned by HBsAg which was coated in a microtiter plate, after five rounds of biopanning, 56 phage clones were identified specific to HBsAg. The specificity of ScFv was evaluated by ELISA and immunohistochemistry, respectively. RESULTS: The data of HB sAg-ScFv DNA digestion and DNA sequencing showed that the ScFv gene is composed of 750 bp. ELISA and immunohistochemistry demonstrated that the human single chain Fv antibody against hepatitis B surface antigen has a specific combination character with hepatitis B surface antigen of different sources and paraffin-embedded patients tissue specimens, it did not react with normal liver tissue and HCV. CONCLUSIONS: The application of HBsAg specific ScFv in immunohistochemistry was successfully achieved.

Bacteriophages↗
PubMed2002

[Quasispecies and variations of hepatitis B virus: core promotor region as an example].

OBJECTIVE: To investigate the HBV quasispecies groups in the patients with chronic HBV infection. METHODS: A set of specific primers was synthesized according to DNA sequence of HBV strain found in China. The whole core promoter (CP) region was amplified by PCR method from the sera of 3 patients with chronic HBV infection, and the PCR products were subcloned into pGEM Teasy vectors. The clones were randomly selected to be sequenced. Sequence comparison of the selected clones was made to find the difference. RESULTS: By comparison, it was found that each sequence of selected clones was different. The point mutation always occurred in TATA-like boxes, especially from T to C replacement on 184 site. There is a hot region (33.3% 5/15) in basic core promoter where deletion mutation frequently happened. CONCLUSIONS: There is a hot deletion region near DR I in CP. The replacement at 184 nt (T to C) in the third TATA-like box may influence the expression of pre-C/C protein. The sequencing results suggest that there are HBV quasispecies groups in chronically infected patients.

DNA, Viral↗
PubMed2002

[Study on the incidence and risk factors for in-hospital stroke in patients with acute myocardial infarction].

OBJECTIVE: To determine the incidence and risk factors for in-hospital stroke in patients with acute myocardial infarction (AMI). METHODS: Two thousand one hundred and thirty-three patients with acute myocardial infarction were studied retrospectively. History, demographic, clinical, thrombolytic and anticoagulant data of AMI were obtained through review of the medical record. The relative risk of in-hospital stroke in patients with AMI was estimated using multiple nonconditional logistic regression to adjust for potential confounding factors. RESULTS: Among 2,133 consecutive patients admitted with acute myocardial infarction to hospitals in Shandong and Hubei provinces, 98 (4.59%) experienced strokes during hospitalization. In our analysis, anterior infarction was the most important risk factor for in-hospital stroke (ischemic and hemorrhagic) in patients with AMI (RR = 7.04), followed by history of hypertension (RR = 3.41), previous stroke (RR = 1.69), atrial fibrillation (RR = 2.22), advanced age (RR = 1.04), and higher heart rate at enrollment (RR = 1.03). CONCLUSIONS: The incidence of in-hospital stroke in patients with AMI increased with lower rate of using thrombolytic agents. Thrombolytic therapy was noticed as a protective factor for stroke after AMI. The risk factors for in-hospital stroke with AMI were history of hypertension, previous stroke, atrial fibrillation, advanced age, anterior infarction, and higher heart rate at enrollment.

Adult↗
PubMed2002

[Studies on chemical constituents of effective part of Gastrodia elata].

OBJECTIVE: To study the chemical constituents of effective part of Gastrodia elata. METHOD: The constituens were isolated by column chromatographies with silica gel and ODS, and identified by NMR, MS spectra. RESULT: Six compounds were isolated and identified. CONCLUSION: Three compounds were isolated from this plant for the first time.

Gastrodia↗
PubMed2002

[Studies on chemical constituents of the rhizomae of Ligusticum chuanxiong].

OBJECTIVE: To study the chemical constituents of Ligusticum chuanxiong. METHOD: The constituents were separated and purified by column chromatography with silica gel and ODS, and identified by NMR, MS spectral data. RESULT: Eight compounds were isolated and identified as Ligustilide(I), 4,5-dihydro-3-butylphthalide(II), Z, Z'-6,6',7,3 alpha-diligustili-de(III), Z-6,8',7,3'-diligustilide(IV), Z'-3,8-dihydro-6,6'7,3' alpha-diligustilide(V), 4-hydroxy-3-butylphthalide(VI), ferulic acid(VII) and Xiongterpene(VIII). CONCLUSION: Compound VIII is a new compound.

4-Butyrolactone↗
PubMed2002

Diagnosis and surgical management for retrosternal thyroid mass.

OBJECTIVE: To understand the clinical manifestations, diagnostic methods, surgical management and prognosis of retrosternal thyroid masses in various pathological types. METHODS: Sixty-four cases of retrosternal thyroid masses with surgical intervention were analyzed retrospectively. RESULTS: Trachea-compressed symptoms (65%) and shadows beside the trachea at thoracic inlet (94%) were the most common clinical findings, chest X-ray (70%) and CT scan (96%) had higher diagnostic rate. No death occurred during operation or hospitalization among these patients. Total complications occurred in 15.7% cases (11/70) (including 3 preoperative cases with hoarseness) and postoperative pathological results were mainly multinodular goiter (54.7%), thyroid adenoma (21.9%) and thyroid carcinoma (15.6%) (including local carcinomatous change). CONCLUSIONS: Diagnosis of retrosternal thyroid mass can be correctly made by chest X-ray and CT scan. Most operations on retrosternal thyroid masses can be performed safely through cervical incision with minimal morbidity and low recurrence rate. Retrosternal thyroid carcinoma was potentially invasive and could hardly be resected completely, hence with poor prognosis.

Adenoma↗
PubMed2002

[Alterations of DPC4/SMAD4/MADH4 gene detected in paraffin-embedded tissues of human pancreatic carcinomas].

OBJECTIVE: To demonstrate the alterations of DPC4/SMAD4/MADH4 gene in paraffin-embedded tissues of pancreatic carcinomas. METHODS: Forty-six cases of resected specimens containing carcinomatous tissue and normal pancreatic tissue were analysed for possible DPC4 gene mutations by polymerase chain reaction (PCR)and single-strand conformation polymorphism (SSCP). The DNA sequencing technique was applied to determine the patterns of gene mutation in the PCR-SSCP positive cases. Fifty-six cases of pancreatic carcinoma along with the specimens corresponding normal pancreatic tissues were studied by in situ hybridization (ISH) and immunohistochemistry (IHC) techniques for gene expression in mRNA and protein level. RESULTS: The homozygous deletion rate of exon 1, 2, 3, 4, 8, 11 of DPC4 gene in pancreatic carcinoma was 28.26%, while the mutation rate of DPC4 gene was 21.74%. In these tumors, there were 3 cases of nonsense mutation, 5 cases of missense mutation, 1 case of deletion and missense mutation, 1 case of insertion mutation. Positive rates of SMAD4 in carcinomatous tissues detected by the ISH and IHC were 53.57% and 58.93% respectively, whereas they were 91.07% and 89.29% in the matched normal tissue respectively. There were significant difference between cancer and normal tissue (P < 0.05). Thrity-two cases were positive of DPC4/SMAD4 with all methods mentioned above, the coincident rate was 87.50% (28/32). The coincidence between gene detection and ISH of SMAD4 was 87.50%, and it was 96.88% between gene detection and IHC of SMAD4. Of all 56 cases, the coincidence of the positive rates of SMAD4 detected by ISH and IHC was 91.07%. No significant difference among the positive rates of DPC4/SMAD4 as detected by the three different techniques (P > 0.05). CONCLUSIONS: The main mechanisms of inactivation of DPC4 gene in pancreatic carcinoma are homozygous deletion and mutation. The product of DPC4 expression is significantly decreased in cancer group compared with the normal tissues. As a tumor suppressor gene, DPC4 alteration is an important molecular event in pancreatic carcinoma, and probably plays a crucial role in cancer development and progression.

Adult↗
PubMed2002

A spectroscopic study of the 3(1) pi g Rydberg state of 7Li2.

With pulsed optical-optical double resonance (OODR) fluorescence excitation spectroscopy Rydberg states of 7Li2 in the energy region of 35,500-38,000 cm-1 were studied and 146 transitions into the 3(1) pi g state of 7Li2 were measured. They were assigned to 10 vibrational levels of the 3(1) pi g state. A new set of Dunham constants, RKR potential curve, and Franck-Condon factors for the transitions form the A 1 sigma u+ state are derived. The perturbations between the 4(F)1 sigma g+, 5 (1) sigma g+, 6 (1) sigma g+, 2 (G) 1 pi g Rydberg states with the 3 (1) pi g state are discussed. The lambda-doubling splitting of the observed levels can be ignored with our accuracy (0.2 cm-1).

Energy Transfer↗
PubMed2002

[Preparation and characterization of polymeric ultrafine particles on Hb-SDS-Ag hydrogeles (I)].

Preparation and characterization of polymeric particles ultrafine on Hb-SDS-Ag have been reported. (Taking fixed quantity of Hb, SDS to be putting in a beaker, then Ag(NH3)2NO3 solution, pH--12 buffer, n-heptane and iso-amyl-alcohol were added. And fixed quantity formaldehyde, n-heptane and iso-amyl-alcohol were added in another beaker. They were stirred emulsification respectively, both of mixture were mixed in a three-well flask and which were reacted for 1.5 h at 60 +/- 0.5 degrees C. After cooling, the precipitation was separated and washed once and again, it was dried) The structure of surface have been investigated by XRD, TEM and FT-IR for this polymeric ultrafine particles, and size of diameter is about 120 nm. It is shown that Ag+ ion first formed chemical binding with Hb, then reduced to Ag particles and finally collected to a network polymers of coated by Hb.

Animals↗
PubMed2002

Cloning and expression of the gene of augmenter of liver regeneration in yeast cells.

OBJECTIVE: To study the function of augmenter of liver regeneration (ALR) as a regulatory factor that specifically stimulates hepatic cell regeneration, we constructed yeast expressive vector of ALR and expressed it in yeast cells. METHODS: Total RNA was extracted from HepG2 cells, and reverse transcription polymerase chain reaction (RT-PCR) was performed to amplify the coding region of ALR. The products were cloned into PGEM-T vector and sequenced, then cloned into PGBK T7 vector. The recombinant plasmid PGBK T7-ALR was transformed into yeast AH109. The yeast protein was extracted and analyzed by SDS-polyacrylamide gel electrophoresis (SDS-PAGE) and Western blotting hybridization technique. RESULTS: DNA sequencing results confirmed that the coding region of ALR was correctly inserted into the yeast expression vector, and Western blotting assay showed that recombinant ALR was successfully expressed in yeast. Its molecular weight was identical to the theoretical value of 15 000 Da; the protein was found inside the yeast cells. CONCLUSION: The successful expression of ALR in yeast cells makes it possible to study further on its biological function.

Blotting, Western↗
PubMed2002

Quasispecies groups in the core promoter region of hepatitis B virus.

OBJECTIVES: To investigate the mutation of the basic core promoter (BCP) of hepatitis B virus (HBV) and clarify the significance of HBV quasispecies groups in patients with chronic HBV infection. METHODS: A set of specific primers was synthesized according to the HBV DNA sequence of a Chinese strain. The BCP was amplified by PCR method from the serum of 40 patients with chronic HBV infection, and the PCR products of 2 patients were subcloned into pGEM Teasy vectors. Polyacrylamide gel electrophoresis (PAGE) was employed to display the deletion mutations, and clones with differential length were selected to be sequenced. Sequence comparison was made to find the difference. RESULTS: Two or three bands were displayed by PAGE in 60% patients. The results of sequence analysis showed that there are some kinds of mutations in the BCP region. The substitution always occurs in TATA-like boxes, especially from T to C on 140 site. The deletion mutations were detected in TA1, TA2 and TA3. The 8bp, 20bp deletion mutations frequently happened. CONCLUSIONS: There is a hot deletion region in the BCP. The deletion and the substitution in the TATA-like box may influence the expression of preC/C protein. The sequencing results indicate that there are HBV quasispecies groups in patients with chronic HBV infection.

Base Sequence↗
PubMed2002

[Lyophilized mixture of PCR ingredients and its application].

In this paper we introduce a new storage method of PCR ingredient. PCR mixture except DNA template has been frozen to dry powder by the DNA-Plus system. This kind of powder was stored at room temperature or 4 degrees. PCR has been run in different period of storage. It was discovered that the samples of lyophilization could keep activity for a long time.

English Abstract↗
PubMed2001

Phylogeny of the Simbu serogroup of the genus Bunyavirus.

The Simbu serogroup of the genus Bunyavirus, family Bunyaviridae contains 25 viruses. Previous serological studies provided important information regarding some but not all of the relationships among Simbu serogroup viruses. This report describes the nucleotide sequence determination of the nucleocapsid (N) gene of the small genomic segment of 14 Simbu serogroup viruses and partial nucleotide sequence determination of the G2 glycoprotein-coding region (encoded by the medium RNA segment) of 19 viruses. The overall phylogeny of the Simbu serogroup inferred from analyses of the N gene was similar to that inferred from analyses of the G2 protein-coding region. Both analyses revealed that the Simbu serogroup viruses have evolved into at least five major phylogenetic lineages. In general, these phylogenetic lineages were consistent with the previous serological data, but provided a more detailed understanding of the relatedness amongst many viruses. In comparison to previous phylogenetic studies on the California and Bunyamwera serogroups of the Bunyavirus genus, the Simbu serogroup displays much larger genetic variation in the N gene (up to 40% amino acid sequence divergence).

Nucleocapsid↗