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Biomedical subjects

M Li

Publications and source records attributed to M Li.

At least 217 records · Page 12Linked to original sources
PubMed2001

[Study on the mode of inheritance for familial polycystic ovary syndrome].

OBJECTIVE: To investigate the mode of inheritance of polycystic ovary syndrome(PCOS). METHODS: The first female relatives with irregular cycle and the first male relatives with premature balding in each nuclear family were designated the affected. Their prevalence rates in families were respectively calculated. Analyses of segregation ratio were carried out among 139 nuclear families with PCOS by the methods of simple segregation and complex segregation of genetic epidemiology, respectively. RESULTS: The prevalence rates of irregular cycle among mothers and sisters with PCOS were 37.4% and 33.1% respectively, and the prevalence rates of premature balding among fathers and brothers of patients were 19.4% and 6.5%, respectively. The simple segregation analysis indicated that the segregation ratio of PCOS trait in siblings was 0.3023, the complex segregation analysis indicated that it fitted in with the inheritance model of co-dominant disorder with full penetrance and sporadic cases. The frequency of homozygote of disease gene in population was 0.046. CONCLUSION: PCOS presents the mode of co-dominant inheritance with complete penetrance.

Female↗
PubMed2001

The role of Kupffer cells in non-alcoholic steatohepatitis of rats chronically fed with high-fat diet.

OBJECTIVE: To explore the role of Kupffer cells in non-alcoholic steatohepatitis (NASH) by means of rat model. METHODS: Nineteen male SD rats were randomized into model group (n=10) and normal group (n=9), with a high-fat diet and standard diet for 12 weeks, respectively. Routine histologic features of hepatic section were observed by HE staining. The number and shape of Kupffer cells in the liver were detected by immunohistochemistry and penetrated electron microscope, respectively. RESULTS: All rats of model group developed NASH, which was characterized by obesity and hyperlipidemia. Histopathological examination showed hepatocellular macrovesicular steatosis, lobular inflammatory cell infiltration and necrosis. Compared with normal group, the count of Kupffer cells in the liver was largely increased, and the Kupffer cells in the model group were activated to some extent. Furthermore, these changes of Kupffer cells were in accordance with the degree of steatosis, inflammation and necrosis in the liver of the model group. CONCLUSION: The number and activity of Kupffer cells are increased significantly in NASH induced by high-fat diet, and Kupffer cells might be involved in the pathogenesis of steatohepatitis.

Animals↗
PubMed2001

A simplified method to prepare PCR template DNA for screening of transgenic and knockout mice.

Polymerase chain reaction (PCR) amplification of DNA is the most widely used technique for screening of large numbers of genetically engineered transgenic or knockout mice (Mus musculus). In this report, we present a new DNA preparation procedure for running diagnostic PCR. In this procedure, mouse ear tissue was used directly for PCR after the tissue underwent brief digestion in a solution containing only proteinase K. Using this method, we have successfully screened several lines of single, double, and triple transgenic and knockout mice. The results are reliable and reproducible. The advantage of this new method is that DNA purification by organic extraction or isolation kit was omitted. DNA purification is the limiting factor in terms of time and money when screening transgenic and knockout mice by PCR. In addition, using ear instead of tail tissue can reduce distress of animals because the samples can be obtained when the mice are labeled by ear punch.

Animal Identification Systems↗
PubMed2001

Induction of apoptosis in colon cancer cells by cyclooxygenase-2 inhibitor NS398 through a cytochrome c-dependent pathway.

Nonsteroidal anti-inflammatory drugs (NSAIDs) have shown cancer preventive activity in patients who took them frequently. These drugs can induce tumor cells to undergo apoptosis in vitro. NS398, a cyclooxygenase-2 (COX-2)-selective inhibitor, has been reported to cause apoptosis in cancer cell lines. Therefore, we examined its effect on 15 human colon cancer cell lines and investigated its mechanism of action. NS398 decreased cell viability in all of the cell lines. Tumor cells that expressed COX-2 were shown to be more sensitive to NS398 treatment. In three selected colon cancer cell lines, NS398-induced apoptosis was mediated by the release of cytochrome c from mitochondria and, consequently, by the activation of caspase-9 and caspase-3 and by the cleavage of poly(ADP-ribose) polymerase. In contrast, caspase-8 was not involved in NS398-induced apoptosis, which suggested that the cytochrome c pathway may play an important role in NS398-induced apoptosis in colon cancer cell lines. Therefore, the combination of NS398 with apoptosis-inducing drugs through cytochrome c-independent pathways may be warranted.

Apoptosis↗
PubMed2001

Abnormal desmin protein in myofibrillar myopathies caused by desmin gene mutations.

Muscle proteins were extracted in various sodium dodecyl sulfate buffers from 6 patients with myofibrillar myopathy (MFM) and previously identified with mutations in the desmin gene (desmin myopathy; DesM), 6 with MFM without mutations, and 14 disease controls to search for alterations in biochemistry and solubility of mutated desmin filaments. In the 1% posthigh-speed pellet fraction, desmin was detected with immunoblots only in DesM and not the other MFM. We conclude that mutant desmin forms insoluble aggregates that are specific for the DesM and can be detected with Western blots.

Blotting, Western↗
PubMed2001

[Gene chimeric fusion and expression of nucleocapsid NS3 regions and NS4 regions of hepatitis C virus genome].

Genes encoding HCV core and NS4 antigen epitopes and C33c antigen were cloned from HCV genome by PCR, respectively. Two fused genes were constructed. One contained these three genes, another contained genes encoding C33c antigen and NS4 antigen epitopes. These fused genes were cloned into expression plasmid pET-24(a)+ and pET-22(b)+ under T7 promoter and transformed into E. coli BL21 (DE3) respectively. SDS-PAGE analysis revealed that these fused antigens CCN, CN were highly expressed after the induction by 1 mmol/L IPTG. These Expression products were detected by western blotting with anti-HCV serum.

Escherichia coli↗
PubMed2001

[Kinetics of in vitro drug release from chitosan and N-alkyl chitosan membranes].

By using the so-called "lag-time" method, we studied the effect of membrane thickness(h), initial drug concentration(Co) and flow rate(V) on the difusion coefficient(D) of model drug in membranes. The experiment indicates that D increases as h and v increase; D Keeps constant when C0 changes; Under the same condition, the D value of N-alkyl chitosan membrane is bigger than that of pure chitosan membrane.

Chitin↗
PubMed2001

[Antidepressant effect of water decoction of Rhizoma acori tatarinowii in the behavioural despair animal models of depression].

OBJECT: To assess the antidepressant effect of the water decoction of Rhizoma acori tatarinowii. METHODS: By using the rat forced swimming test and mouse tail suspension test models of depression, the antidepressant effect of Rhizoma acori tatarinowii was observed. RESULTS: The water decoction of Rhizoma acori tatarinowii and Fluoxetine significantly shortened motionless time of rat forced swimming and despair time of mouse tail suspension in the two behavioural despair animal models of depression. Antidepressant effect of water decoction of Rhizoma acori tatarinowii showed dose-dependence in the certain degree. The effect of water decoction of Rhizoma acori tatarinowii was weaker than that of Fluoxetine. There was a significant difference between every dose group of Rhizoma acori tatarinowii and saline control group. CONCLUSION: The water decoction of Rhizoma acori tatarinowii possessed obviously antidepressant effect in the behavioural despair animal models of depression.

Animals↗
PubMed2001

[Establishment of ELISA with TT virus(TTV) and its application to patients with hepatitis and healthy people].

OBJECTIVE: To establish the EIA method for detection of antibody to TT virus (anti-TTV) and to investigate the distribution of anti-TTV in patients with hepatitis and in healthy people. METHODS: The ELISA method using the recombinant expressed product of truncated gene of TTV ORF1 as antigen was developed and was applied to detect anti-TTV in patients with hepatitis and in healthy control. The TTV DNA were detected by nested-PCR. RESULTS: The positive rates of anti-TTV antibodies in different populations were as follows: 1.3% in healthy people, 10.5% in patients with hepatitis A, 12.5% in patients with hepatitis B, 8.3% in patients with hepatitis C, 7.7% in patients with hepatitis D, 12.0% in patients with hepatitis E, 6.5% in patients with hepatitis G, 32.3% in patients with hepatitis non-A to G. The positive rate of TTV DNA was significantly related to that of anti-TTV (P < 0.05). CONCLUSION: The anti-TTV antibodies were detected positive in patients with hepatitis and healthy people, however, its positive rate in patients with hepatitis non-A to G was significantly higher than that in other groups. The fact that anti-TTV antibodies coexist with TTV DNA suggests that the antibody to TTV ORF1 antigen may be an infectious marker of TTV similar to that of anti-HCV.

Antibodies, Viral↗
PubMed2001

[Mutations of genes affecting heart development of Drosophila].

Recent studies suggest that the basic molecular control mechanisms of early heart development are remarkably conserved in Drosophila, vertebrate and human being. Drosophila can be used as a prototype to explore the genetic basis of cardiogenesis in human being. Here, mutations of genes affecting heart development of Drosophila are produced by chemical mutagen methanesulfonicaeid ethyl. With staining of antibody expressed in heart precussor cells of Drosophila, 112 lethal lines were observed to show mutant phenotypes in pericardial cells. Of them, 32 lines differ in their mutant phenotypes from those of known genes. Analysis of cytogenetic mapping shows that they are located in 13 chromosomal regions without known heart-related genes, which implies that these loci contain genes probably involved in the heart development.

Animals↗
PubMed2001

Contribution of endogenously expressed Trp1 to a Ca2+-selective, store-operated Ca2+ entry pathway.

Heterologous expression of the transient receptor potential-1 gene product (Trp1) encodes for a Ca2+ entry pathway, though it is unclear whether endogenous Trp1 contributes to a selective store-operated Ca2+ entry current. We examined the role of Trp1 in regulating both store-operated Ca2+ entry and a store-operated Ca2+ entry current, I(SOC), in A549 and endothelial cells. Twenty different 'chimeric' 2'-O-(2-methoxy)ethylphosphothioate antisense oligonucleotides were transfected separately using cationic lipids and screened for their ability to inhibit Trp1 mRNA. Two hypersensitive regions were identified, one at the 5' end of the coding region and the second in the 3' untranslated region beginning six nucleotides downstream of the stop codon. Antisense oligonucleotides stably decreased Trp1 at concentrations ranging from 10 to 300 nM, for up to 72 h. Thapsigargin increased global cytosolic Ca2+ and activated a I(SOC), which was small (-35 pA @ -80 mV), reversed near +40 mV, inhibited by 50 microM La3+, and exhibited anomalous mole fraction dependence. Inhibition of Trp1 reduced the global cytosolic Ca(2+) response to thapsigargin by 25% and similarly reduced I(SOC) by 50%. These data collectively support a role for endogenously expressed Trp1 in regulating a Ca2+-selective current activated upon Ca2+ store depletion.

Base Sequence↗
PubMed2001

[The genotype analysis of glucose-6-phosphate dehydrogenase deficiency in Yunnan province].

OBJECTIVE: To identify glucose-6-phosphate dehydrogenase (G6PD) gene mutations in 23 patients with G6PD deficiency and to gain further understanding of the molecular and genetic background of G6PD gene in Yunnan province, China. METHODS: The mutations located in exons 2-12 and in parts of introns of G6PD gene were analyzed by amplification refractory mutation system(ARMS), natural and mis-match primer PCR/restrict enzyme, polymerase chain reaction-single strand conformation polymorphism(PCR-SSCP ) analysis and automatic DNA sequencing. RESULTS: Among these 23 samples, 5 different point mutations in G6PD gene were identified, and they constituted 5 genotypes. There were 7 Han and 3 Dai patients with G487A mutation, 7 cases with both intron 11 T93C and C1311T mutations, 4 cases with intron 5 636 or 637 T-->del mutation, 1 case with G871A mutation, and 1 case with G487A/T93C/C1311T mutation. Two haplotypes, 93C/1311T and 93C/1311T/487A were identified in Yunnan. A strong association was observed between C1311T and the Nla III restriction site produced by intron 11 T93C. The findings of the investigators on IVS-5 636 or 637T-->del in Chinese, on G871A in mainland of China, and on G487A in the Han people of Yunnan have not been reported previously. CONCLUSION: G6PD deficiency is very heterogenous in Yunnan; G487A is one of the common mutations in that province and may be of different origins. Possibly IVS-11 T93C mutation is of non-African origin. IVS-11 T93C and C1311T might jointly result in G6PD deficiency. The above data on G6PD gene mutation types could be useful for clinical diagnosis, prevention of G6PD deficiency, and researches in the origin and migration of minorities in Yunnan or other regions.

Adolescent↗
PubMed2001

[Therapeutic potential of recombinant adenovirus expressing p53 in hepatocellular carcinoma cell lines].

OBJECTIVE: To investigate the effects of the recombinant adenoviral vector Ad-p53 on the biological behavior of hepatocellular carcinoma (HCC) cells in vitro and in vivo. METHODS: With recombinant adenoviral vector expressing WT-p53 (Ad-p53), p53 gene was transfected into the HCC cell line, PLC/PRF/5. The cytotoxicities of Ad-p53 to cells were measured by MTT assay. Cell growth properties and cell cycle patterns were assessed with flow cytometry. The animal model was developed by injecting HCC cells into the dorsum of nude mice. Ad-p53 was injected intratumorally. The animals were killed, and then excised tumors were weighed and analyzed for p53 and p21 protein expression using western blot assay. RESULTS: The introduction of exogenous wild-type p53 resulted in the inhibition of cell growth, high G2/M ratio and cell apoptosis, and low S ratio in PLC/PRF/5. The expression of both p53 and p21 proteins was upregulated in the cells. CONCLUSIONS: Replication-deficient adenoviral vector expressing WT-p53 may be useful for gene therapy of HCC.

Adenoviridae↗
PubMed2001

Do P1 and N1 evoked by the ERP task reflect primary visual processing in Parkinson's disease?

OBJECTIVES: To evaluate whether P1 and N1 evoked by ERP tasks could appropriately reflect primary visual processing in Parkinson's disease (PD). METHODS: We recorded ERPs in 13 PD patients with duration of illness less than 5 years and 18 age-matched normal control subjects. P1 and N1 from Oz were evoked by a visual oddball and a delayed matching S1-S2 task. The effect of different events on P1 and N1 was studied. All patients were given an ECD-SPECT examination, and the SPECT images were overlaid on the 3D-MRI. The correlation of P1 or N1 to the regional cerebral blood flow (rCBF) was studied. RESULTS: P1 was not influenced by different events. There was no significant P1 differences between the PD and the normal group. N1 was significantly shorter and smaller in the patients than that in the normal group. N1 amplitude after the waveform subtraction (target-frequent) in the PD group did not show significant difference with that in the normal controls, nor with the N1 before the subtraction. Nd, the subcomponent of N1 after the subtraction in the patients was significantly earlier and smaller than that in the normal controls. P1 only weakly correlated with the rCBF in the occipital lobe. N1 was correlated with the rCBF in a global region. CONCLUSIONS: The results provided some evidence that P1 might reflect the primary visual processing, and N1 might be involved in both primary and cognitive visual processing. The altered N1 in the PD patients might be due to the deformed Nd.

Aged↗
PubMed2001

Evaluation of angiogenesis in non-small cell lung cancer: comparison between anti-CD34 antibody and anti-CD105 antibody.

PURPOSE: Angiogenesis is an essential process in the progression of malignant tumors. Whereas pan-endothelial markers, such as CD34, are generally used in evaluation of angiogenesis, pan-endothelial antibodies react with not only "newly forming" vessels but also normal vessels just trapped within tumor tissues. It has been recently reported that anti-CD105 antibody preferentially reacts with "activated" endothelial cells in angiogenic tissues. Thus, the superiority of anti-CD105 monoclonal antibody (mAb) in evaluation of angiogenesis of non-small cell lung cancer (NSCLC) was assessed. EXPERIMENTAL DESIGN: A total of 236 patients with resected NSCLC were retrospectively reviewed. Intratumoral microvessel density (IMVD) was determined with an anti-CD34 mAb (CD34-IMVD) and with an anti-CD105 mAb (CD105-IMVD). RESULTS: The mean CD34-IMVD and CD105-IMVD were 179.9 and 41.6, respectively. Whereas CD34-IMVD was significantly correlated with the expression of vascular endothelial growth factor (P = 0.003), CD105-IMVD was more closely correlated with vascular endothelial growth factor expression (P < 0.001). The 5-year survival rate of the lower CD105-IMVD patients was 74.9%, significantly higher than that of the higher CD105-IMD patients (60.4%, P = 0.018). Whereas the 5-year survival rate of the lower CD34-IMVD patients seemed higher than that of the higher CD34-IMVD patients (63.7%), the difference did not reach a statistical significance (P = 0.137). Multivariate analysis confirmed that higher CD105-IMVD was a significant factor to predict poor prognosis (P = 0.029), whereas CD34-IMVD was not (P = 0.070). CONCLUSIONS: Anti-CD105 mAb proved to be superior to anti-CD34 mAb in evaluation of angiogenesis in NSCLC.

Aged↗
PubMed2001

[Community characteristics of benthonic animals and its relationship to environmental factors in the Nanhu Lake, Changchun].

There are only 21 species of benthonic animals in the Nanhu Lake, Changchun. The dominant species in the benthos community are obvious, and the individual quantity of Limnodrilus hoffmeisteri, Branchiura sowerbyi, and Tendipus plumosus accounts for 87% of the total individual quantity of all benthonic animals. It indicates that the water in the Nanhu Lake is suffering serious organic pollution, and belongs to an eutrophic lake. The peak values of benthos biomass and energy are found in July(48.23 g WW.m-2 and 241.16 kJ.m-2 respectively), while the maximum individual quantity is appeared in May(401 ind.m-2). The distribution of Oligochaeta and aquatic insects has a significant positive correlation to organic content in the sediment(alpha < 0.05). The community structure of benthonic animals reflects adequately the feature of the Nanhu Lake as an eutrophic lake in temperate zone.

Animals↗
PubMed2001

[Studies on the relationship between clinicopathological features and human papillomavirus types in female lower genital tract carcinoma].

OBJECTIVE: To investigate the relationship between clinicopathological features and human papillomavirus types in female lower genital tract carcinoma. METHODS: Clinicopathological features of 100 cases of female lower genital tract carcinoma (63 cervical carcinoma and 37 vulvar carcinoma) were studied retrospectively. Standard PCR (HPV type 6/11, 16, 18) was applied to formalin fixed, paraffin embedded sections. RESULTS: There were 54 cases of cervical carcinoma and 33 cases of vulvar carcinoma in the 87 cases of target DNA qualified samples. The HPV detection rate in cervical carcinoma was 83.3%. HPV16 (55.6%) and HPV 18(24.4%) were the predominant types. In vulvar carcinoma, HPVs, mainly HPV 16(70%, 7/10), were detected in basaloid (83.3%, 5/6) and warty carcinoma (83.3%, 5/6), but none in conventional type of keratinized squamous cell carcinoma (0.0%, 0/21). Three of the 6 women with basaloid carcinoma were associated with cervical squamous neoplasia, and the same HPV type was found in both lesions in 2 of the 3 patients with two primary tumors. Four patients with basaloid carcinoma recurred after simple vulvectomy or local excision, but no lymph node metastasis occurred and all were still alive at last follow-up, with a median follow-up of 6.3 years. In contrast, the majority of the women with keratinized squamous cell carcinoma were over 65 years of age, with histologic extensive keratinization and poorer prognosis. CONCLUSIONS: A high detection rate of HPV 16 and 18 was found in cervical carcinoma. However, the sensitivity of HPV in vulvar carcinoma seems to be more related to histologic type.

Adult↗