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Biomedical subjects

Tong Zhao

Publications and source records attributed to Tong Zhao.

49 records · Page 3Linked to original sources
PubMed2003

Expression of RASSF1A gene in nasopharyngeal carcinoma.

OBJECTIVE: To investigate the role of RASSF1A gene in the pathogenesis of nasopharyngeal carcinoma (NPC). METHODS: RASSF1A gene expression was examined by semi-quantitative reverse transcriptional-polymerase chain reaction (RT-PCR) in 32 specimens of poorly differentiated squamous cell carcinoma from patients with primary NPC, 16 specimens of histologically normal nasopharyngeal epithelia, and 4 NPC cell lines (CNE1, CNE2, HNE1, HNE2). The loss of heterozygosity (LOH) on chromosome 3p21.3 was detected using D3S4604 microsatellite marker in NPC. RESULTS: Reduction in the expression level of RASSF1A was significantly lower in NPC than in normal nasopharyngeal epithelium(P=0.001). Allelic delection (LOH) on 3p21.3 was assessed in 43.75% of the NPC specimens. However, there was no evidence to demonstrate the relationship between RASSF1A expression and the patient's age, gender, and some clinical features such as lymph node metastasis, TNM stage and serum titer of EBV (VCA/IgA) antibody (P>0.05). The expression of RASSF1A was reduced in NPC specimens from NPC patients with distant metastasis compared with that of patients without distant metastasis (P=0.014). CONCLUSION: Down-regulated RASSF1A gene expression might be an event in the later stages of the tumorigenesis of NPC, and the 3p21 region may contain tumor suppressor genes that are could be deeply involved in the tumorigenesis of NPC.

Adult↗
PubMed2003

Immunohistochemical detection of Kikuchi's lymphadenitis.

OBJECTIVE: To evaluate significance of immunohistochemistry in Kikuchi's lymphadenitis (KFD). METHODS: Biopsy specimens were obtained from 42 KFD cases for microscopic examination after the sections were stained with haematoxylin and eosin, and the immunohistochemical features were analyzed by monoclonal antibodies (CD20, CD8, CD45RO, CD57, CD68) and polyclonal antibody (myeloperoxidase, MPO). RESULTS: Morphologically, the lymph node lesions comprised various histiocytes, plasmacytoid monocytes, immunoblasts, small lymphocytes and nuclear fragments. In all the cases, the histiocytes were invariably observed and most of them were positive for CD68 and MPO. Immunoblasts and plasmacytoid monocytes were easily observed in proliferative stage. Immunohistochemical examination revealed strong focal T-cell positivity for the antibodies but with scarce B cell (CD20) and NK cell (CD57) positivity in the lesion area, where few or virtually no neutrophils were seen. CONCLUSION: Immunohistochemical analysis can be crucial for the differential diagnosis of KFD.

Adolescent↗
PubMed2003

[Explore the origin of H/RS cells on protein and gene].

OBJECTIVE: To explore the origin and clonality of H/RS cells. METHODS: Immunohistochemical method was used to detect the expression of B-cell-specific activator protein (BSAP) and CD(20) in 33 paraffin-embedded tissues of classical Hodgkin lymphoma (cHL). IgH gene rearrangement was detected in 33 paraffin-embedded cHL tissue and 6 microsectioned H/RS cell samples. The PCR products of a case of cHL and its microsectioned cells were sequenced. RESULTS: H/RS cells were positive for BSAP in 30 of 33 (90.91%) cHL cases and positive for CD(20) in 10/33 (30.30%) cases. There was a significant difference between the expression of BSAP and CD(20) in H/RS cells (P = 0.000). BSAP and CD(20) were positive in almost all B cells of lymph node reactive hyperplasia and malignant cells in B-cell lymphomas while were negative in all malignant cells of T-cell lymphomas. 16 of 33 cHL were positive for gene rearrangement, and microsectioned H/RS cells in 14 of 19 tubes displayed clonal bands of rearrangement. There was no significant difference among the rearrangement rates in tubes containing different numbers of H/RS cells (P = 0.280). Sequencing analyses of the PCR products from both paraffin-embedded tissue and microsection of the same patient revealed the rearranged V segments, but the sequences were not identical. CONCLUSION: H/RS cells were originated from B cells of different differentiation stage.

Adolescent↗
PubMed2002

[CoCl2-induced enhancement of glucose transport activity in mediating hypoxic tolerance in cultured hippocampal neurons].

The effect of CoCl(2) pretreatment on glucose transport activity of cultured newborn rat hippocampal neurons and its role in neuronal hypoxic tolerance were observed. The results showed that the 2-deoxy-D-[1-(3)H ]glucose uptake rate and the mRNA expressions of glucose transporters (GLUT1 and GLUT3) in the hippocampal neurons were significantly increased after a 24-hour pretreatment with CoCl(2). The cell injury induced by 6-hour or 8-hour hypoxic exposure was also greatly reduced by CoCl(2) pretreatment. The protective effect of CoCl(2) on the neurons was largely abolished by cytochalasin B, a specific inhibitor of glucose transporters. The results suggest that CoCl(2) can increase mRNA expressions of GLUT1 and GLUT3 and glucose transporter activity of the neurons, which may be an important mechanism for the increased tolerance of the neurons to hypoxia.

Animals↗
PubMed2002

[Expression and significance of B-cell-specific activator protein of H/RS cell in classical Hodgkin's Lymphoma].

OBJECTIVE: To explore the expression of B-cell-specific activator protein (BSAP) of H/RS cell in classical Hodgkin's lymphoma (cHL). METHODS: Immunohistochemical method was used to detect the expression of BSAP in 33 samples of formalin-fixed, paraffin-embedded tissues of cHL. Nine samples of lymph node of reactive hyperplasia, 10 samples of B-cell lymphoma, and 10 samples of T-cell lymphoma were also detected as BSAP controls. Mouse-anti-human monoclonal antibodies CD20, CD30 and CD15 were detected among the cHL cases as routine comparison. RESULTS: 30 of 33 (90.91%) cases of cHL were BSAP expression positive in H/RS cells, while all of the 33 (100%) cases of background B-lymphocytes were BSAP positive. Almost all B cells of lymph node reactive hyperplasia were BSAP positive. All malignant cells in B-cell lymphoma were BSAP positive, while all malignant cells in T-cell lymphoma were BSAP negative. Among the 33 cases of cHL there was a significant difference between the expression of BSAP and the expression of CD20 (30.30%) in H/RS cells (P = 0.000), and no significant difference between the expression of CD30 (93.94%) and CD15 (75.75%, P = 0.082). CONCLUSION: The frequent expression of BSAP in H/RS cells of classical Hodgkin's disease provides further evidence for its B-cell origin and helps to identify H/RS cells. The expression of BSAP in H/RS cells can be used to distinguish HL from anaplastic large cell lymphoma (ALCL).

Adolescent↗
PubMed2002

Gastrin, somatostatin, G and D cells of gastric ulcer in rats.

AIM: To investigate the relationship among gastrin, somatostatin, G and D cells in gastric ulcer and in its healing process in rats. METHODS: Fourty-nine Wistar rats were divided into 7 groups. The gastric ulcer model was induced by acetic acid successfully. The gastrin and the somatostatin in rat plasma, gastric fluid and antral tissue were measured by radioimmunoassay(RIA). G and D cells in antral mucosa were analyzed with polyclonal antibody of gastrin and somatostatin by immunohistochemical method and Quantimet 500 image analysis system. RESULTS: In gastric ulcer, the level of gastrin in plasma, gastric fluid, and antral tissue increased, that of somatostatin declined, and the disorder gradually recovered to the normal level in the healing process. Immunohistochemical technique of G and D cells in antral mucosa demonstrated that the number of G cells increased and that of D cells decreased, both areas of G and D cells declined, the ratio of number and area of G/D increased in gastric ulcer, and the disorder gradually recovered in the healing process. CONCLUSION: In gastric ulcer, the increased gastrin secreted by G cells, the declined somatostatin secreted by D cells, and the disordered G/D cell ratio can lead to gastrointestinal dysfunction.

Animals↗
PubMed2002

[Detection of Mycobacterium tuberculosis in lung cancer tissue by indirect in situ nested PCR].

OBJECTIVE: To localize Mycobacterium tuberculosis DNA (TB-DNA) in lung cancer tissue and to investigate the possible relationship of this bacterial infection with the development of lung cancer. METHODS: A sensitive and specific indirect in situ nested PCR (ISNPCR) was used to identify and localize TB-DNA in 15 formalin fixed paraffin-embedded lung cancer tissue specimens, which had been demonstrated to be positive for TB-DNA by conventional PCR. RESULTS: Positive granules of TB-DNA in brown color was found mainly in the cytoplasm of the alveolar epithelial cells, pulmonary macrophages, inflammatory cells and a few tumor cells within lung cancer tissues. CONCLUSION: Mycobacterium tuberculosis infection may play a role in the pathogenesis of lung cancer.

Humans↗
PubMed2002

[Immunohistochemical detection of micrometastases in cervical lymph nodes from squamous cell carcinoma of tongue in neck dissection specimens].

OBJECTIVE: The purpose of this study was to explore a feasible method to detect the micrometastases. METHODS: Totally 152 cases of negative cervical lymph nodes (CLNs) from 30 patients with squamous cell carcinoma in tongue were included in this study. The HE-stained slices of the CLN were reexamined by two experienced pathologists and, conformed that no carcinoma cells were found. Two slices were made from each paraffin specimen and, the slices were stained with the microwave immunohistochemical technique with monoclonal antibody CK (AE1/AE3) (DAKO Co. Denmark, 1:100). RESULTS: Among these 152 cases 7 (4.6%) positive lymph nodes were found in 4(13.3%) patients, and CLN metastases were found in all the patients before the surgical treatment. Most of the micro-metastatic nodes appeared in the upper deep cervical area, except that one of them was found in the submandibular triangle. CONCLUSION: The results suggest that micrometastases frequently occurred in negative lymph nodes. The present method may be useful in detecting the micrometastases of lymph nodes and in evaluating clinical stages of patients with oral cancers.

Carcinoma, Squamous Cell↗
PubMed2002

[Study of DLC1 gene expression in nasopharyngeal carcinoma].

OBJECTIVE: To elucidate the role of DLC1 gene in nasopharyngeal carcinoma (NPC). METHODS: The expression of DLC1 was studied by means of RT-PCR combined with sequencing in 32 cases non-keratinizing carcinoma, 16 cases of histologically normal nasopharyngeal epithelia, and 4 NPC cell lines (CNE1, CNE2 and HNE1, HNE2). RESULTS: The expression of functional transcript of DLC1 was undetected in all NPC cell lines, and it was significantly reduced or undetected in NPC biopsies in comparison with normal nasopharyngeal mucosae (P < 0.001). The expression of DLC1 was significantly reduced in T3, T4 stages of NPC biopsies, compared with that in T1, T2 stages (P = 0.01). However, there was no relationship between the expression of DLC1 and other clinical features in NPC patients, such as age, sex, lymph node metastasis, distant metastasis, TNM clinical stages and the serum titer of EBV (VCA/IgA) antibody (P > 0.05). An aberrant transcript of DLC1, which lacked exon 8, was found in 7 cases of NPC and only in 1 case of normal nasopharyngeal mucosae. CONCLUSION: DLC1 gene may play a critical role in the tumorgenesis of NPC. The down-expression of DLC1 may be associated with the local invasion of NPC. The aberrant isoform may be related with the dysfunction of DLC1 gene.

Adult↗
PubMed2001

Expression of cyclin D1 in small cell lymphoma and its clinical implications.

OBJECTIVE: To observe the expression of cyclin D1 and explore its clinical significance in small cell lymphoma. METHODS: Immunohistochemical method was used to detect the expression of CD20, CD45RO and cyclin D1 in 31 formalin- fixed and paraffin-embedded tissue samples of human small cell lymphomas. RESULTS: Twenty-eight cases were categorized into B cell lymphoma and 3 into T cell lymphoma. Only 5 cases of B cell lymphoma had cyclin D1 expression (17.86%) that did not significantly differ between nodal and extranodal lymphomas (P>0.05), indicating the presence of mantle cell lymphoma. CONCLUSION: The overexpression of cyclin D1 is a highly characteristic and specific indicator that discriminates mantle cell lymphoma from other small cell lymphomas, and this protein may offer critial guidance for therapeutic protocol and prognostic estimation.

Journal Article↗
PubMed1997

cDNA Sequences of Two Anti-mammals Neurotoxins from Scorpion Buthus martensii Karsch.

The total mRNA was prepared and purified from the venom gland of scorpion Buthus martensii Karsch (BmK). The cDNA library of this venom gland was then constructed using reverse transcription. Two cDNAs encoding the anti-mammalian neurotoxins, named as BmK M1 and BmK M9, were selectively amplified by PCR and sequenced. Both have open reading frames of 252 bp encoding 84 residues of the toxin precursors, including a 19 amino acid signal peptide, the mature toxin with 64 residues, and an additional Arg tail at the carboxyl-terminus which was removed during post-protein processing. The deduced amino acid sequence of BmK M1 was completely identical with the known sequence of the natural toxin BmK M4, whereas the other BmK M9 shared a high homology with the natural toxin BmK M4, differing only in two residues. The cDNA of BmK M1 showed 87.2% homology with that of the African scorpion Lqh alphaIT.

Journal Article↗
PubMedDate not supplied

Aberrations in the fragile histidine triad(FHIT) gene may be involved in lung carcinogenesis in patients with chronic pulmonary tuberculosis.

It has been suggested that pulmonary tuberculosis (PT) is associated with lung carcinogenesis. To identify the genetic characteristics of precancerous PT lesions in lung, 20 patients were selected with a 1-month to 36-year history of PT and 20 lung cancer patients with a 2- to 53-year history of previous PT that had undergone lung resection at the Nanfang Hospital from 1999 to 2003; PCR-based microsatellite analysis with DNA extracted from microdissected tissues and immunohistochemical analysis of FHIT protein expression in samples of hyperplasia and cancer obtained from 40 patients were performed. Three microsatellite markers of the FHIT gene for loss of heterozygosity (LOH) analysis were used. LOH of the FHIT locus was frequently found among the lesions of hyperplasia and atypical hyperplasia obtained from 6 patients with a 1- to 36-year history of PT (12 of 30 informative lesions, 40%); none of 70 hyperplastic lesions obtained from 14 patients with a 1- to 11-month history of PT showed LOH at the FHIT gene; 17 of 20 (85%) cancer lesions obtained from 20 lung cancer patients with a 2- to 53-year history of previous PT showed LOH at the FHIT gene, which was significantly higher than hyperplasia and atypical hyperplasia obtained from patients with a 1- to 36-year history of PT in FHIT LOH (Fisher's exact test p = 0.003). Additionally, the level of FHIT protein expression was frequently reduced in the hyperplastic lung epithelial cells of PT with a 1- to 36-year history and cancer tissue. Our findings suggest that allelic loss of the FHIT gene may be involved in carcinogenesis in the lung of patients with PT.

Acid Anhydride Hydrolases↗