Biomedical subjects
Publications and source records attributed to Qun He.
Suggested a new blocking method for DNA microarray: 1-iodo-propane. We compared the difference between the two block reagents and the blocking results in different blocking time. The results showed that 1-I-propane is batter-blocking reagent than succinic anhydride in DNA chip. 1h blocking time is enough for blocking.
OBJECTIVE: To determine the effects of an antioxidant (An7845) on the proliferation inhibition and apoptosis induction of a human leukemia cell line (K562). METHODS: We evaluated the effects of An7845 on K562 cell proliferation by cellular enumeration in liquid culture assay, MTT assay and colony formation assay. We also verified the effects of An7845 on K562 cell apoptosis by cellular morphology and the DNA fragments appeared in agarose gel electrophoresis. RESULTS: The proliferation of K562 leukemia cells was inhibited by An7845 (5 x 10(-8) - 5 x 10(5) mol/L) in a dose-dependent manner. K562 cells were induced toward apoptosis by An7845 (5 x 10(-7) mol/L). CONCLUSION: An7845 can effectively inhibit the proliferation and induce the apoptosis of K562 leukemia cells.
Phosphorylation of the Neurospora circadian clock protein FREQUENCY (FRQ) regulates its degradation and the proper function of the clock. The mechanism by which FRQ undergoes degradation has not been established. Here we show that FRQ is likely ubiquitylated in vivo, and its proper degradation requires FWD1, an F-box/WD-40 repeat-containing protein. In the fwd1 disruption strains, FRQ degradation is severely impaired, resulting in the accumulation of hyperphosphorylated FRQ. Furthermore, the circadian rhythms of gene expression and the circadian conidiation rhythms are abolished in these fwd1 mutants. Finally, FRQ and FWD1 interact physically in vivo, suggesting that FWD1 is the substrate-recruiting subunit of an SCF-type ubiquitin ligase responsible for FRQ ubiquitylation and degradation. Together with the recent finding that Slimb (the Drosophila homolog of FWD1) is involved in the degradation of the Period protein in flies, our results indicate that FWD1 regulates the degradation of FRQ in Neurospora and is an evolutionarily conserved component of the eukaryotic circadian clock.
OBJECTIVE: To investigate the effects of lithium chloride on the proliferation and apoptosis of human leukemia cell line (K562). METHODS: The effects of lithium chloride on the proliferation of K562 leukemia cells were evaluated by liquid culture assay, MTT assay, and colony formation assay. The effects of lithium chloride on the apoptosis of K562 leukemia cell were verified by cellular morphology and the agarose gel electrophoresis of DNA fragments. RESULTS: 1. The proliferation of K562 leukemia cells was inhibited by lithium chloride (10-50 mmol/L) in a dose-dependent manner. 2. With lithium chloride (30 mmol/L), the apoptosis cells could be observed in cellular morphology, and DNA ladder was also observed in agarose gel electrophoresis. CONCLUSION: Lithium chloride can inhibit the proliferation of K562 cells and cause the apoptosis of K562 cells.
To optimize and screen the most suitable target gene length,concentration and printing solution in cDNA microarray, housekeeping genes, such as beta actin and GAPDH, were selected as targets and hepatitis B virus gene as negative control. The RT-PCR primers that spanned at least one intron and whose products were at between 189 bp and 1078 bp were designed with primer premier 5.0, so did the hepatitis B virus gene PCR primer. After polymerase chain reaction, the products were purified with ethanol and dissolved in 3xSSC, 50% DMSO and 0.5 mol/L carbonate buffer(pH=9.0)respectively. The concentrations of target genes were adjusted at 0.5 microg/microL, 1.0 microg/microL and 1.5 microg/microL. The hybridization signals had a good specificity. No signal showed in either negative control (HBV) or blank control (printing solution only). There was no significant difference in target gene lengths. The P value of beta actin (189 bp,491 bp,974 bp) and GAPDH (227 bp,552 bp,1078 bp) was 0.378 and 0.866 respectively. There was no significant difference among concentrations(P=0.648),too. However, the higher the concentration was, the stronger the signals would be. Among the three kinds of printing solution, 50% DMSO was the best (P=0.0001), while the other two had no difference by multi-comparison (P=0.142). The target gene at length between 200 bp and 1000 bp has got the same hybridization signals.50% DMSO printing solution and the target gene concentration of 0.5 microg/microl are suitable for good hybridization.
OBJECTIVE: To study the clinical and pathologic features of aggressive angiomyxoma (AAM) and its occurrence, treatment and prognosis. METHODS: The 8 cases of AAM were analyzed retrospectively, among which 6 cases in vulva, 2 cases in perineum, vagina and pelvis. As well we performed immunohistochemical studies. RESULTS: The neoplastic cells were at least focally immunoreactive for vimentin (7/7), smooth muscle actin (7/7), factor 8 (7/7), proliferating cell nuclear antigen (4/7), estrogen (3/7) and progesterone (4/7) receptors. All of the examined tumors were negative for S100 protein and cluster designation 68. CONCLUSIONS: AAM is an uncommon mesenchymal tumor that preferentially involves the pelvic and perineal regions of females. In immunohistochemical investigation the neoplastic cells of AAM exhibit fibroblastic and myofibroblastic features. They are characterized by slow growth, infiltration of adjacent structures, absence of distant metastases, a tendency to recur locally and a fairly good prognosis. Treatment should consist of wide surgical excision, as complete as technically possible.
Certain minisatellites exhibit hypervariability with respect to the number of repeat units and, thus, allele length. Such polymorphism is generated by germline-specific recombinational events that occur at high frequencies and lead to the gain or loss of repeat units. In order to elucidate the molecular details of mutagenesis in minisatellites, we have integrated human minisatellites into the yeast genome in the vicinity of a hotspot for meiotic double-strand breaks (DSBs). Here, we describe the results of tetrad analyses of mutations in the human MS205 minisatellite in yeast strains heterozygous for alleles composed of 51 and 31 repeat units, as well as in a strain homozygous for the same 51 repeat unit allele. The length-mutation rate was twice as high in the heterozygous strain as in the homozygous strain, suggesting that sequence divergence between alleles enhances the generation of length mutations. In the case of heterozygotes, the frequency of length mutants resulting from inter-allelic exchange was significantly higher in tetrads with three viable spores than in tetrads with four viable spores, indicating that there is a higher probability for spore mortality in tetrads originating from meioses during which inter-allelic exchange of repeat units occurs. In an attempt to explain these findings, we propose a model for minisatellite mutation involving recombination, in which sequence divergence between alleles results in a heteroduplex containing numerous mismatches. We suggest that convergent mismatch-repair tracts in this heteroduplex give rise to a DSB that may be repaired by an additional round of recombination resulting in mutation of a third allele, or be lethal if such recombination fails. It appears probable that the formation of such additional mutants is the major explanation for the difference in meiotic length-mutation rates between the heterozygous and homozygous yeast strains, and that this phenomenon contributes to high germline length-mutation frequencies at minisatellites in humans.
Preprophase bands in the neck canal mother cell and the central cell of the archegonium of the fern Dryopteris crassirhizoma are observed with immunofluorescence microscopy. No phragmoplast is found during mitosis of the neck canal mother cell; however, the phragmoplast develops very well in the central cell. The neck canal mother cell undergoes karyokinesis but not cytokinesis and finally produces only one binucleate neck canal cell. However, the central cell undergoes cytokinesis and produces an egg cell and a ventral canal cell. These observations suggest that the preprophase band in the neck canal mother cell loses its function as a cytokinetic apparatus and becomes an evolutionary vestige in the development of the archegonium.
OBJECTIVE: To deepen the understanding of patients with complete necrosis of the ureter after renal transplantation for early diagnosis and treatment. METHODS: Of 5 patients with complete necrosis of the ureter after renal transplantatioin between January 1991 and April 2001 in our hospital, 4 were male and 1 was female (mean age, 35 years). Seven to 12 days after renal transplantation, native pyeloureterestomy was performed for 1 patient, and the remaining 4 patients received the cutting of the diatal necrosis ureter and vesicoureterostomy because of urine leakage. Six to seven weeks later when the ureter stents were pull out, native pyeloureterestomy or pyeloureteroplasty was performed for the 4 patients because of uropenia and hydronephrosis. RESULTS: Five patients showed normal function of the kidney postopcreation (follow up: 6 - 12 months) without hydronephrosis. CONCLUSIONS: When distal necrosis of the ureter is observed after renal transplantation, complete necrosis of the ureter may occur. Native pyeloureterostomy or pyeloureteroplasty is an effective treatment.
OBJECTIVE: To investigate the morphological features, immunohistochemical speciality of the gastrointestinal stromal tumors (GISTs), and its histogenesis as well. METHODS: The morphologic characteristics of GISTs were studied in 65 cases using light microscopy and 17 cases by electron microscopy. The expression of c-kit (CD117), CD34, vimentin, SMA, actin, desmin, S-100 and MBP were detected in all the cases with EnVision trade mark staining. RESULTS: Among 65 cases of GISTs, 46 were spindle cell type, 6 epithelioid cell type and 13 mixture type, equivalent to 85.5% (65 of 76) of all of the mesenchymal tumors of gastrointestinal tract admitted in the same period. The epithelioid cell type tumors composed of mainly the epithelioid cells, predominantly short spindle, oval or round in pattern, with an overall eosinophilic cytoplasm by hematoxylin-eosin stain. Focal cytoplasmic vacuolization was often seen. Sometimes signet-ring like cells and cells with a clear cytoplasm were seen in the epithelioid stromal tumor. The tumor cells arranged in interlacing fascicles forming whorls or sometimes cell clusters. Electronic microscopy showed the presence of interdigitating cell processes, in some areas, synapse-like structure and numerous desmosome-like junctions as well as a few gap junctions and small round neurosecretory granules. There were also abundant intermediate filaments and thin filaments of actin-type with longitudinal condensations (dense bodies). All of the 65 stromal tumors were strongly positive for vimentin (100%), 61 out of 65 tumors positive for CD117 (c-kit) (93.8%) and 51 out of 65 positive for CD34 (78.5%). Some cases also expressed SMA, actin, S-100 and MBP. CONCLUSIONS: GISTs were the most frequent mesenchymal tumor seen in the gastrointestinal tract. Under light microscope, the morphology of stromal tumors looks sometimes like a leiomyoma and Schwannoma. The application of immunohistochemical markers (particularly CD117 and CD34) and ultrastructural study are considered necessary for the differential diagnosis. GISTs may originate from the pluripotential precursor cells like the interstitial cells of Cajal.
OBJECTIVE: To optimize the aqueous extraction process for preparation of Yuxianling Granules in order to provide a basis for industrial-scale produce. METHODS: The amount of extract and the content of ferulic acid were used as indexes of the extraction process for Yuxianling Granules. The aqueous extract optimum condition of preparation was selected by orthogonal experimental design. RESULTS: The optimum extraction condition was adding ten, eight times amount of water into crude drug, soaking for 30 min, decocting for 1.5 h, 1.0 h. Both the content of ferulic acid and the amount of extract were the highest. CONCLUSION: The above extraction process gave the most rational, feasible and satisfactory results.
Using AAs method, we detected serum Zn, Cu, Mg, Cr in the women with barrenness and hysteromyoma disease. The results showed that the level of serum Cu and Cr of women with hysteromyoma were significantly higher than those in the healthy control group. (P < 0.01), the level of serum Zn of those were significantly lower than those in the control (P < 0.01). In the serum of those with barrenness disease, the level of Zn, Cr is significantly lower than the control group (P < 0.01). It is suggested that trace element Cu, Zn, Cr are interrelated with hysteromyoma disease, Zn, Cr are interrelated with women barrenness disease.
AIM:To investigate the effect of cytokines on the liver necrosis.METHODS: rIL (interleukin)-1, rIL-6, rIFN (interferon), rTNF (tumor necrosis factor) -alpha with or without D-galactosamine (D-GAL) were injected into the abdominal cavity of mice separately.ALT, TBIL (total bilirubin) and histological changes were observed.RESULTS: There was no effect on hepatocyte of normal mice after injection of rIL-1, rIL-6, rIFN alone or together. The serum total bilirubin (TBIL) and liver necrosis of mice increased after rTNF-alpha, rIL-6 or rIFN were used separately with D-GAL. The TBIL level (&mgr;mol/L)was 46.19 plus minus 10.62, 44.55 plus minus 12.9 and 41.94 plus minus 14.9, higher than that caused by D-GAL alone (TBIL, 26.67&mgr;mol/L plus minus 11.14&mgr;mol/L). The serum TBIL of mice and the degree of liver necrosis increased after injection of IL-1, IL-6 with D-GAL and rTNF-alpha.CONCLUSION: Cytokines, like IL-1, IL-6, IFN&agr and TNF-&agr;joined in the process of hepatocyte necrosis.They can enhance the degree of liver necrosis induced by D-GAL.
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