PubMed Health⌕ Search

Biomedical subjects

M M Liu

Publications and source records attributed to M M Liu.

17 recordsLinked to original sources
PubMed2006

Immunocapture UPPCR combined with DGGE for rapid detection of Shigella species.

AIMS: To develop an immunocapture universal primer PCR (iUPPCR) combined with denaturing gradient gel electrophoresis (DGGE) and evaluate it as a method permitting rapid detection of Shigella species and their serotypes. METHODS AND RESULTS: This method amplifying the conserved regions of bacterial 16S rRNA genes of different species or serotypes of Shigella dysentery bacilli captured and enriched by polyvalent antibodies can detect and distinguish causative pathogens rapidly. Four serotypes from three Shigella species including Shigella dysenteriae serotype 1, Shigella boydii serotype 1, Shigella flexneri serotypes 1a and 3a were examined. CONCLUSION: Our approach could be adopted for not only axenic bacterial population but also mixed communities and achieve rapid detection of various bacteria from the same genus or species in one sample. SIGNIFICANCE AND IMPACT OF THE STUDY: The iUPPCR-DGGE method was shown to be more convenient than serotype-specific-antibody-based method of iUPPCR for Shigella species detection and it could be also applied to the quick detection for other kinds of pathogens with many serotypes.

Electrophoresis, Polyacrylamide Gel↗
PubMed2000

[Cloning of human TRAIL cDNA and its expression in COS-7 cells].

The human TRAIL cDNA was amplified with the total RNA from the human acute promyelocytic leukemia cell line HL-60 by means of RT-PCR, and was cloned into the pGEM-T vector. The DNA sequence analysis showed that it was consistent with the published sequence. Then, the insert of human TRAIL cDNA was subcloned into the mammalian expression vector pcDNA3. The hybrid plasmid pcDNA3-hTRAIL was transformed into COS-7 cells, and transiently expressed in the COS-7 cells. The activity of the expressed product could induce apoptosis in U937 cell line.

Animals↗
PubMed1999

Dynamic muscle force predictions from EMG: an artificial neural network approach.

EMG signals of dynamically contracting muscle have never been used to predict experimentally known muscle forces across subjects. Here, we use an artificial neural network (ANN) approach to first derive an EMG-force relationship from a subset of experimentally determined EMGs and muscle forces; second, we use this relationship to predict individual muscle forces for different contractile conditions and in subjects whose EMG and force data were not used in the derivation of the EMG-force relationship; and third, we validate the predicted muscle forces against the known forces recorded in vivo. EMG and muscle forces were recorded from the cat soleus for a variety of locomotor conditions giving a data base from three subjects, four locomotor conditions, and 8-16 steps per subject and condition. Considering the conceptual differences in the tasks investigated (e.g. slow walking vs. trotting), the intra-subject results obtained here are superior to those published previously, even though the approach did not require a muscle model or the instantaneous contractile conditions as input for the force predictions. The inter-subject results are the first of this kind to be presented in the literature and they typically gave cross-correlation coefficients between actual and predicted forces of >0.90 and root mean square errors of <15%, thus they were considered excellent. From the results of this study, it was concluded that ANNs represent a powerful tool to capture the essential features of EMG-force relationships of dynamically contracting muscle, and that ANNs might be used widely to predict muscle forces based on EMG signals.

Algorithms↗
PubMed1999

Prevalence and impact of upper gastrointestinal symptoms in the Canadian population: findings from the DIGEST study. Domestic/International Gastroenterology Surveillance Study.

OBJECTIVE: The prevalence and impact of upper gastrointestinal (GI) symptoms in the general population are poorly defined. Most data are obtained from selected samples derived from patients presenting to health care providers. As part of a larger international effort (The DIGEST study), we examined the prevalence of upper GI symptoms among the general Canadian population, as well as their psychosocial and economic impact. METHODS: A sample of 1036 adults was studied, its demographic characteristics closely matching those of the general Canadian population. A validated detailed questionnaire measured the prevalence, severity, and frequency of 15 digestive symptoms, as well as demographic information, use of medication and medical resources, other illnesses, and dietary habits. The Psychological General Well-Being Index, a self-administered questionnaire, assessed the individual's subjective sense of well-being. RESULTS: Of the sample population, 28.6% reported substantial symptoms in the preceding 3 months, the majority (111/153 subjects) for >1 yr; 34.1% reported having never experienced significant GI symptoms. The most bothersome symptoms were primarily related to dysmotility-like symptoms in 54.9% of those with chronic symptoms, ulcer-like symptoms in 12.4%, and related to heartburn in 42.5%. Chronic upper GI symptoms were associated with a highly significant (p < 0.001) decrease in all facets of the Psychological General Well Being Index. CONCLUSIONS: Upper GI symptoms are very prevalent in the general Canadian population and substantially affect the quality-of-life and psychological well-being of those affected. Dysmotility-like symptoms, rather than heartburn, are the most common chronic upper gastrointestinal symptoms in the general population.

Adolescent↗
PubMed1998

[Assignment of a novel zinc finger gene ZNF191 to human chromosome 18Q12.1 by human/rodent somatic cell hybrid panel and fluorescent in situ hybridization].

A novel human zinc finger gene, ZNF191, was assigned to chromosome 18 by hybridization of human/rodent hybrid cell panel to a full-length cDNA as a probe. Meanwhile, a human genomic DNA lambda/DASH library was screened using this cDNA probe and several positive clones were obtained. Fluorescence in situ hybridization (FISH) was performed by using one of these positive clones, 16-1, as a probe. Thus, the ZNF191 gene was precisely mapped in 18q12. 1. To date, some hereditary diseases and tumors have been found to be associated with this region by analysis of genetic linkage and loss of heterozygosity. Hence, it suggested that the gene ZNF191 can be taken as a candidate gene responsible for those diseases and tumors.

Chromosome Mapping↗
PubMed1997

Cloning of a gene (RIG-G) associated with retinoic acid-induced differentiation of acute promyelocytic leukemia cells and representing a new member of a family of interferon-stimulated genes.

In a cell line (NB4) derived from a patient with acute promyelocytic leukemia, all-trans-retinoic acid (ATRA) and interferon (IFN) induce the expression of a novel gene we call RIG-G (for retinoic acid-induced gene G). This gene codes for a 58-kDa protein containing 490 amino acids with several potential sites for post-translational modification. In untreated NB4 cells, the expression of RIG-G is undetectable. ATRA treatment induces the transcriptional expression of RIG-G relatively late (12-24 hr) in a protein synthesis-dependent manner, whereas IFN-alpha induces its expression early (30 min to 3 hr). Database search has revealed a high-level homology between RIG-G and several IFN-stimulated genes in human (ISG54K, ISG56K, and IFN-inducible and retinoic acid-inducible 58K gene) and some other species, defining a well conserved gene family. The gene is composed of two exons and has been mapped by fluorescence in situ hybridization to chromosome 10q24, where two other human IFN-stimulated gene members are localized. A synergistic induction of RIG-G expression in NB4 cells by combined treatment with ATRA and IFNs suggests that a collaboration exists between their respective signaling pathways.

Amino Acid Sequence↗
PubMed1997

Use of arsenic trioxide (As2O3) in the treatment of acute promyelocytic leukemia (APL): I. As2O3 exerts dose-dependent dual effects on APL cells.

Recent clinical studies in China showed that As2O3 is an effective and relatively safe drug in the treatment of acute promyelocytic leukemia (APL). We found previously that As2O3 can trigger apoptosis of APL cell line NB4 cells, which is associated with downregulation of bcl-2 gene expression and modulation of PML-RAR alpha chimeric protein. To further understand the mechanisms of this alternative therapy for APL, we investigated in this report the effects of a wide range of concentrations of As2O2 on cultured primary APL cells, all-trans retinoic acid (ATRA)-susceptible (NB4 cells) and ATRA-resistant (MR2 subclone) APL cell lines. The results indicated that As2O3 had dose-dependent dual effects on APL cells: inducing preferentially apoptosis at relatively high concentrations (0.5 to 2 micromol/L) and inducing partial differentiation at low concentrations (0.1 to 0.5 micromol/L). The rapid modulation and degradation of PML-RAR alpha proteins, which was induced by As2O3 at 0.1 to 2 micromol/L, could contribute to these two effects. Bone marrow and peripheral blood examination showed that myelocyte-like cells, probably as a result of partial in vivo differentiation, and degenerative cells increased after 2 to 3 weeks of continuous in vivo As2O3 treatment when leukemic promyelocytes decreased. In conclusion, combination of induction of apoptosis and partial differention could be the main cellular mechanisms of As2O3 in the treatment of APL, and PML-RAR alpha could play an important role in determining the specific effects of As2O3 on APL cells.

Antineoplastic Agents↗
PubMed1997

EEN encodes for a member of a new family of proteins containing an Src homology 3 domain and is the third gene located on chromosome 19p13 that fuses to MLL in human leukemia.

The MLL gene, the closest human homologue to the Drosophila trithorax gene, undergoes chromosomal translocation with a large number of different partner genes in both acute lymphoid and acute myeloid leukemias. We have identified a new partner gene, EEN, fused to MLL in a case of acute myeloid leukemia. The gene is located on chromosome 19p13, where two other MLL partner genes, ENL and ELL/MEN have also been identified. The deduced protein of 368 aa contains a central alpha-helical region and a C-terminal Src homology 3 (SH3) domain most similar to the C-terminal SH3 domain found in the Grb2/Sem-5/Drk family of genes. Sequence analysis of the fusion MLL/EEN transcript in our patient reveals that exon 6 of MLL is fused to the N-terminal end of EEN, a fusion that would create a chimeric protein that includes the major functional domain of EEN. EEN is expressed in a variety of tissue types and encodes a protein of approximately 46 kDa. The EEN protein is the human homologue of a member of a recently described murine SH3 domain-containing protein family. It is also highly related to a putative gene identified in Caenorhabditis elegans, and a number of similar sequences are present in the EST databases of several species.

Amino Acid Sequence↗
PubMed1996

A short CIC-2 mRNA transcript is produced by exon skipping.

CIC-2 is a voltage- and volume-regulated chloride channel expressed in many tissues. We have shown that CIC-2 in rat lung airways is significantly down-regulated after birth [Murray,C.B. et al. (1995) Am. J. Respir. Cell Mol. Biol., 12, 597-604]. During PCR amplification from rat lung cDNA, a second transcript was identified which is 60 bp shorter than the full length sequence. The peptide translated from this 60 bp sequence contains many positively charged amino acid residues. Rat genomic DNA sequencing showed that the 60 bp sequence is an intact exon. A 71% pyrimidine content and an AAG 3'-end splice site in the intron immediately upstream from the 60 bp sequence were identified which may account for the alternative splicing of the following exon. Human genomic sequence analyses demonstrated similar intron-exon arrangement. A high CT content and an AAG 3' acceptor site were conserved in the intron corresponding to the rat upstream intron. The presence of the full length short form transcript was confirmed in rat kidney by RT-PCR, and the ratio of the long and the short form transcripts varied significantly according to the tissues examined, with the lowest long/short form ratio found in the lung among the tissues studied. Our data demonstrated that the alternatively spliced short form (CIC-2S) is transcribed in many rat tissues, the ratio of the long/short form transcripts is lower in the lung compared with the brain, and the genomic organization in this area is conserved in rat and human.

Alternative Splicing↗
PubMed1994

Unicornuate uterus with rudimentary horn.

OBJECTIVES: To identify the effects of unicornuate uterus with rudimentary horn on reproductive function and analyze the diagnosis and treatment of the condition. METHODS: The study was based in the gynecological unit of a city based Medical Center in Mainland China. Twenty-two cases of this anomaly were selected from a group of 130 cases of uterine abnormalities and were retrospectively analyzed. RESULTS: This kind of anomaly can cause hematometra and endometriosis leading to acute abdominal pain, infertility, rupture of pregnant rudimentary horn and obstetrical complications with pregnant semi-uterus. CONCLUSIONS: Rudimentary horn should be removed if detected.

Abdominal Pain↗
PubMed1993

[Removal of incarcerated intrauterine devices by combined methods].

Incarcerated IUDs are difficult to manage. Through clinical analysis of 41 cases with incarcerated IUDs, the value of X-ray, ultrasonographic and hysteroscopic examinations in combined use was assessed, especially in locating and describing the concrete shape of the incarcerated IUD before and during the removal operations. With the aid of these diagnostic methods 39 IUDs (95.12%) were removed through the vaginal route, while the remaining 2 (4.88%) were taken out by laparotomy, one had hyperplasia of the endometrium accompanied by retained broken pieces of the IUD, the other had uterine anomaly (uterus didelphys) with an incarcerated IUD. 40 out of the 41 IUDs were stainless steel rings, and only 1 was a Cu V IUD. The advantages and drawbacks of the three above-mentioned diagnostic were discussed as well as the effect of use. The different method of IUD removal were described.

Adult↗
PubMed1988

Fibromyoma of the vagina.

Fibromyoma of the vagina is a rare condition. The earliest reference contributed to such a tumor is attributed to Deneys De Leyden in 1733, although Phillips gives the distinction to Jacobs Denys in 1773. In 1882, Kleinwaechter published an authoritative review of 53 cases. Scheffrey and Farell collected 163 cases in 1934. Bennet and Ehrlich estimated in 1941 that approximately 200 cases had been reported and added another 9 cases of their own. Since then there had been only case reports, until 1965 Kettle described another six cases. In the Chinese literature five cases were collected since 1949. At Gu-Lou (Drum Tower Hospital) another 11 cases were seen which will be reported below. The estimated number of this tumor will probably not exceed 250 cases.

Adult↗
PubMed1987

[Is rotation in vacuum extraction possible?].

Vacuum extraction is a traction instrument and hardly suitable for accomplishing rotation. This assumption is disproved by means of two new suction cups that are being used in China. These suction cups and their use are described together with the relevant indication.

Delivery, Obstetric↗