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Biomedical subjects

Bo Jiang

Publications and source records attributed to Bo Jiang.

70 records · Page 4Linked to original sources
PubMed2003

[Pit pattern and endoscopic mucosal resection in diagnosis and treatment of colorectal tumors].

OBJECTIVE: To explore the effective methods to diagnose and treat colorectal cancer in its early stage. METHODS: 1 205 patients were examined by colonoscopy and mucosa staining with indigocarmine. The pit patterns were observed with magnifying endoscope and stereomicroscope according to the Kudo classification. The pathological diagnoses of the lesions were compared with their pit patterns. Electrocoagulation resection was performed on the prominent lesions and endoscopic mucosal resection (EMR) or endoscopic partial mucosal resection (EPMR) was performed on the flat lesions. RESULTS: In the 282 patients 478 prominent and flat lesions were found. There were 16 cases of laterally spreading tumor (LST), including I case of pit pattern II, 6 of pit pattern IIIL, 8 of pit pattern IV, and 1 of pit pattern Va, with 2 cases of intramembrane cancer and 1 case of IIa + IIc lesions invading the superficial myometrium among them. EMR and EPMR were performed on 14 LST lesions, 22 IIa lesions, and 14 IIb lesions. CONCLUSION: The examination of pit pattern is very important in early diagnosis of colorectal cancer and differentiation tumorous from non-tumorous lesions. V type pit pattern is an indicator of colorectal cancer. EMR and EPMR are safe and effective for flat lesions.

Colonoscopy↗
PubMed2003

Growth inhibitory signalling by TGFbeta is blocked in Ras-transformed intestinal epithelial cells at a post-receptor locus.

The transforming growth factor beta (TGFbeta) family of growth regulatory peptides plays an important role in the regulation of gastrointestinal epithelial cell homeostasis. Loss of growth inhibitory signalling by TGFbeta is common in the context of Ras-transformation and it has been hypothesized that loss of TGFbeta receptor II (TGFbetaRII) expression accounts for the emergence of TGFbeta resistance. Here we examine the functional significance of reduced TGFbetaRII expression in intestinal epithelial cells transformed by oncogenic Ras. TGFbeta-induced signalling events downstream of TGFbetaRII were examined in Ras-transformed RIE-1 cells (RIE-Ras) and compared to the parental RIE-1 line. RIE-Ras cells were resistant to growth inhibition by TGFbeta. Neither overexpression of TGFbetaRII in RIE-Ras cells nor expression of constitutively active TGFbetaRI restored sensitivity to TGFbeta. TGFbeta-mediated phosphorylation of Smad2 occurred in TGFbeta-resistant RIE-Ras cells, as well as other TGFbeta-resistant cells lines (HT-29, SW620) expressing low levels of TGFbetaRII. Nuclear translocation of Smad2 and Smad4 occurred equally in RIE-Ras and parental RIE cells. The activity of TIEG2, a TGFbeta-inducible SP1-like transcription factor, was reduced in RIE-Ras cells, implying that resistance in Ras-transformed RIE cells occurs by a transcriptional mechanism.

Active Transport, Cell Nucleus↗
PubMed2003

Large-scale essential gene identification in Candida albicans and applications to antifungal drug discovery.

Candida albicans is the primary fungal pathogen of humans. Despite the need for novel drugs to combat fungal infections [Sobel, J.D. (2000) Clin Infectious Dis 30: 652], antifungal drug discovery is currently limited by both the availability of suitable drug targets and assays to screen corresponding targets. A functional genomics approach based on the diploid C. albicans genome sequence, termed GRACETM (gene replacement and conditional expression), was used to assess gene essentiality through a combination of gene replacement and conditional gene expression. In a systematic application of this approach, we identify 567 essential genes in C. albicans. Interestingly, evaluating the conditional phenotype of all identifiable C. albicans homologues of the Saccharomyces cerevisiae essential gene set [Giaever, G., Chu, A.M., Ni, L., Connelly, C., Riles, L., Veronneau, S., et al. (2002) Nature 418: 387-391] by GRACE revealed only 61% to be essential in C. albicans, emphasizing the importance of performing such studies directly within the pathogen. Construction of this conditional mutant strain collection facilitates large-scale examination of terminal phenotypes of essential genes. This information enables preferred drug targets to be selected from the C. albicans essential gene set by phenotypic information derived both in vitro, such as cidal versus static terminal phenotypes, as well as in vivo through virulence studies using conditional strains in an animal model of infection. In addition, the combination of phenotypic and bioinformatic analyses further improves drug target selection from the C. albicans essential gene set, and their respective conditional mutant strains may be directly used as sensitive whole-cell assays for drug screening.

Alleles↗
PubMed2003

[Role of phospholipase D in priming of rat peripheral leukocytes by lipopolysaccharide and antigen].

OBJECTIVE: To investigate whether or not lipopolysaccharide (LPS) and ovalbumin (OA) prime rat peripheral leukocytes, the effect of sensitization on priming and the role of phospholipase D in priming. METHODS: The peripheral leukocytes were separated and purified from sensitized or unsensitized rats. LPS or OA was used as a priming agent and formylmethionylphenylalanine (fMLP) as an activating agent. Degradation of leukocyte was determined by measurement of elastase release and myeloperoxidase (MPO) activity. Phospholipase D (PLD) activity was assayed by the generation of choline,which was measured by choline-oxidase-catalyzed formation of H(2)O(2) and Trinder reaction. RESULT: Compared with cells treated by fMLP alone,leukocytes from unsensitized rat challenged with fMLP after incubated with LPS released more elastase and MPO (P<0.05). But there was no significant difference between leukocytes challenged with fMLP after incubated with OA and fMLP treated alone. In sensitized rat,there was no difference between leukocytes challenged with fMLP after incubated with LPS and fMLP treated alone. But leukocytes challenged with fMLP after incubated with OA released significantly more elastase and MPO than fMLP treated alone (P<0.05). A significant correlation was obtained between the release of elastase and PLD activity (r(s)=0.51,P<0.01), and also between the release of MPO and PLD activity (r(s)=0.73,P<0.01) in unsensitized rat. In sensitized rat, it was 0.48 (P<0.01) and 0.37 (P<0.05) respectively. CONCLUSION: (1) LPS primes peripheral leukocytes from unsensitized rats; (2) OA primes peripheral leukocytes from actively sensitized rats; (3) PLD plays a role in priming of rat peripheral leukocytes.

Animals↗
PubMed2003

[Ecological feedback significance of polyphenols in organic layer of forest soil].

By comparing polyphenols (total polyphenols and condensed tannin) and other chemical and biological properties in soil organic layers during the transformation and regeneration of pure mature spruce stand in middle Europe, the functions of polyphenols in forest ecosystem were approached. The results showed that polyphenols concentration had a significant positive correlation with effective cation exchange capacity (ECEC), but no relation with organic C. The net N mineralization had no significant correlation with total polyphenols, organic C and C/N ratio, but had a significant negative correlation with condensed tannin. Polyphenols concentration also positively correlated with 1 mol.L.-1 KCl extractable C and N. It is suggest that although the polyphenols have no obvious physiological function in tree metabolism, it should be paid attention to its ecological feedback significance in the whole ecosystem.

Ecology↗
PubMed2002

Changes in ceramide levels upon catechins-induced apoptosis in LoVo cells.

It has been demonstrated that there is difference in the induction of apoptosis in LoVo cells by (-)-epigallocatechin-3-gallate (EGCG), (-)-epigallocatechin (EGC), and (-)-epicatechin (EC). In this study, we explored changes in ceramide levels upon the three catechins-induced apoptosis in LoVo cells. Addition of C2- and C6-ceramide to LoVo cells mimicked EGCG or EGC in leading to apoptotic death. Further measurement of intracellular ceramide content showed that the treatment of LoVo cells with EGCG or EGC resulted in a rapidly transient increase in ceramide content, and then back gradually to base line level, whereas the action of EC was just opposite to that of EGCG or EGC. These results suggest there is difference in the generation of intracellular ceramide by the three catechins and ceramide may take part in the regulation of EGCG- or EGC-induced apoptosis in LoVo cells.

Apoptosis↗
PubMed2002

[Comparison of curative effect for colon flat lesion between mucosa resection and fulguration with high frequency current after mucosa staining under magnifying endoscope].

OBJECTIVE: To observe the relationship between the pit patterns and pathology and compare the curative effect for colon flat lesion between endoscopic mucosa resection (EMR) and fulguration with high frequency current (FHFC). METHODS: They were divided to two groups. There were 37 cases for FHFC in group A, and 34 cases for EMR in Group B. The two groups were comparabal. Examining patients suffering with colon flat lesions with magnifying endoscope and observing the pit patterns of mucosa after staining with indicarmine. RESULTS: The pit patterns of inflammatory or hyperplastic lesions were mainly pit II, adenoma pit III and pit IV, and carcinomatous lesions pit IV and pit V. The worse the differentiation degree of lesions was, the higher the pit patterns were. There were no difference (P > 0.05) between group A and B in complication and quantity, classification and distribution of lesions. No canceration was detected in 21 cases with adenoma in group A, while 4 cases of canceration (all were adenocacinoma) was found in 20 cases whith adenoma in group B. There was significance in canceration between two groups (P < 0.05). CONCLUSIONS: The worse the differentiation degree of lesions was, the higher pit patterns were. EMR and FHFC share the same validity and security when treating the flat lesions, but by EMR, doctors could judge whether the lesions were resected completely, once the remained lesions were found, they could be resected immediately again lesion in case of omission of canceration.

Adult↗
PubMed2002

Novel strategies in antifungal lead discovery.

There have been significant developments in fungal genomics over the past year. The recently released genome sequences of Aspergillus fumigatus and Cryptococcus neoformans have provided unprecedented opportunities for comparative genomics studies of many clinically relevant fungal pathogens. Emerging experimental analysis tools, such as fitness profiling and protein microarrays, have greatly enhanced our ability to conduct genome-wide functional studies.

Antifungal Agents↗
PubMed2002

Endogenous Kv channels in human embryonic kidney (HEK-293) cells.

The human embryonic kidney cells (HEK-293) have been widely used as one mammalian expression system in the study of voltage-gated K+ (Kv) channels. Understanding the endogenous Kv channels in these cells is the prerequisite for the characterization of the heterogeneously expressed Kv channels in these cells. In the present study we screened the transcriptional expression of different Kv genes in HEK-293 cells using reverse transcribed DNApolymerase chain reaction (RT-PCR) method. Among 16 Kv genes examined in native HEK-293 cells 10 Kv genes were reproducibly amplified, including those Kv a subunits encoding for the delayed rectifier (IK) [Kv1.1, Kv1.2, Kv1.3, Kv1.6, and Kv3.1], and for the transient outward Kv channels (IA) [Kv1.4, Kv3.3, Kv3.4, and Kv4.1] as well as a Kvbeta2 subunit. The whole-cell outward rectifier IK currents in the native HEK-293 cells were recorded (203 +/- 13 pA at +30 mV, n = 82) with the patch-clamp technique. In about 42% of the examined cells, IA coexisted with IK currents. IK currents were inhibited by tetraethylammonium chloride (TEA) at 1 and 10 mM by 39.5 and 48.4%, respectively. A 39.6% inhibition of IK currents was also observed in the presence of4-aminopyridine (4-AP, 5 mM). Interestingly, both TEAand 4-AP also inhibited IA currents. 4-acelamido-4'-isothiocyanalostilbene-2, 2'-disulfonic acid (1 mM), a Cl- channel blocker, had no effect on the endogenous outward currents. We concluded that multiple endogenous Kv genes were expressed in native HEK-293 cells, which possessed significant endogenous IK and IA currents with unique pharmacological properties.

Cell Line↗
PubMed2002

[PCR cloning of 3'-terminal repeat fragments of Clostridium difficile toxin A and toxin B gene].

OBJECTIVE: To explore a method to rapidly detect the presence of Clostridium difficile. METHODS: PCR was used to amplify DNA fragments from the highly conserved and repeated domains of the 3'-terminal of Clostridium difficile toxin A gene and toxin B genes. RESULTS: The fragments 960 bp and 1,851 bp in length were respectively amplified from toxin A and toxin B, while the control bacteria presented no distinct results. CONCLUSION: The 960 bp and 1,851 bp fragments are specific for Clostridium difficile and PCR can be used to detect Clostridium difficile from the stool. As the peptides encoded by these conserved domains have high hydrophobicity and strong antigenicity, manufacture of the protein vaccine by gene engineering is possible on the basis of these conserved domains.

Bacterial Proteins↗
PubMed2002

[Expression of Fas genes transduced into colorectal cancer cells].

OBJECTIVE: To construct colorectal cancer cells expressing exogenous Fas gene and observe the expression level of its mRNA and protein before and after transduction. METHODS: Fas cDNA was inserted into the multiple cloning site of the expression vector pBK-CMV with molecular cloning technique, and the resultant recombinant plasmid was transduced into colorectal cancer LoVo cells via lipofectamine. G418 was utilized to screen the positive clones containing the recombinant plasmid, where Fas mRNA and protein expression was determined with Western blotting and dot blotting. RESULTS: pBK-CMV Fas cDNA plasmid was successfully constructed. The transduced colorectal cancer cells were screened by G418 and a resistant cell line (LoVo Fas cells) was obtained. Fas expression was detected in both transduced and non-transducted cell lines, but the expression level of both Fas mRNA and protein was much higher in the former, which showed lowered proliferation rate and lengthened doubling time and logarithm growth period than the non-transducted cells, but the difference was not significant. Treatment of the transduced cells with Fas antibody produced significant difference (P<0.05), manifested by apparently inhibited cell growth. CONCLUSIONS: LoVo cells normally has only very low expression level of Fas gene, while transduction with pBK-Fas cDNA can enhance the efficiency of Fas mRNA and protein expressions. Fas antibody significantly inhibits the growth and proliferation of in vitro cultured Fas-expressing LoVo cells.

Colorectal Neoplasms↗
PubMed2002

Chromoendoscopy and high-magnification colonoscopy in early detection of colorectal cancer.

Flat and depressed lesions in the colons are difficult to detect with conventional colonoscopic techniques, and chromoendoscopy with high magnification has consequently gained wide application for early detection of colorectal cancer and its precursors. These techniques allow targeted in vivo luminal treatments and make possible earlier and more accurate diagnosis on the basis of pit pattern classification as proposed by Kudo Sinei. According to studies conducted by Japanese researchers, magnification chromoendoscopy can be used to assess the histology and invasive depth of the cancer, and thus help in the detection of flat and depressed colonic lesions and the subsequent surgical treatment of these lesions by way of endoscopic mucosal resection (EMR) or endoscopic piecemeal mucosal resection (EPMR). Due attention should be given to the clinical significance of high-magnification chromoendoscopy in the identification of the lesions.

Colonoscopy↗
PubMed2002

[Serrated adenoma of large intestine: report of 7 cases].

From December 2000 to April 2001, 859 patients were examined with coloscopy in our endoscopy centre and 188 cases of adenoma were diagnosed. Among the 188 patients, 7 were found with serrated adenoma that had been confirmed pathologically, including 6 male and 1 female patients, aged 32 to 53 with an average of 44.7 years. All the 7 cases were identified as having single focal lesion, among which 3 were found in the rectum, 1 in the transverse colon, 2 in the ascending colon and 1 in the cecum. The diameter of the lesions ranged from 8 to 27 mm with an average of 15.4 mm.

Adenoma↗
PubMed2002

[The diagnosis and treatment of 25 cases of laterally spreading tumor of the large intestine].

Laterally spreading tumor (LST) originates from the large intestine mucosa with prominent lesions that mainly extend laterally other than vertically. The pathological morphology and evolvement of this disease distinguish itself from other adenomas, and its close association with colorectal cancer has been noted. Up till now, no report on LST involving the large intestine has been available in China, therefore we presently report our experience in the diagnoses and treatment of 25 LST patients (26 lesions) identified with conventional endoscopy and mucosa staining during the period from Nov, 2000 to Oct, 2001. Among the 26 lesions, 11 were classified into granular homogeneous type, 15 into nodular mixed type, and 3 patients were found to have intramucosa carcinoma and 2 serrated adenoma. The biggest lesion was 60 mmx70 mm, the smallest being 11 mmx12 mm, and 6 lesions were within the range of 11 to 20 mm, 9 within 21 to 30 mm with the rest 11 lesions exceeding 31 mm in diameter. Type IV pit pattern was predominant in the the 26 lesions, accounting for a proportion of 61.54% (16/26). Two lesions with V(A) pit pattern and 1 with IV pattern were pathologically diagnosed to be intramucosa carcinoma, and 8 with type III(L) pit pattern were tubulovillous adenoma. Immediate or elective endoscopic mucosa resection or partitioned mucosa resection was performed in the 25 cases without incidences of the complications as bleeding or perforation.

Adult↗
PubMed2002

[Expression of tumor necrosis factor receptor on peripheral blood mononuclear cells from patients with primary hepatocellular carcinoma and effects of treatment on the expression].

OBJECTIVE: To conduct an intensive investigation of the abnormal immune status of patients with primary hepatocellular carcinoma and explore the possible mechanism of biotherapy for these patients. METHODS: The expression of tumor necrosis factor receptor (TNFR)I and TNFR II on peripheral blood mononuclear cells (PBMCs) obtained from 30 normal subjects and 31 patients with primary hepatocellular carcinoma were examined by flow cytometry and S-P staining assay. The effects of biotherapy and chemotherapy administered in the patients were also investigated in terms of the changes in the expressions. RESULTS: The TNFR I and TNFR II expressions in the patients were (28.35+/-9.09) % and (37.45+/-9.51) % respectively, significantly lower than those of normal subjects [(38.54+/-8.51) % and (44.89+/-9.08) %]. The biotherapy for the patients caused an increase of TNFR I expression to (42.86+/-9.02)%. CONCLUSION: There are significant immune abnormalities in patients with primary hepatocellular carcinoma, and this study may offer some theoretical basis for the implementation of biotherapy in such cases.

Adult↗