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Biomedical subjects

Tong Zhao

Publications and source records attributed to Tong Zhao.

At least 37 records · Page 2Linked to original sources
PubMed2005

[Differential expression of 63 novel genes located on chromosome 3p21-22 in nasopharyngeal carcinoma].

OBJECTIVE: To identify novel genes that may participate in the pathogenesis of nasopharyngeal carcinoma (NPC). METHODS: Sixty-three single copies of expressed sequence tag (EST) clusters mapped in the region of D3S1609-D3S1295 on chromosome 3p21-22 were obtained and assembled into long or full-length cDNA consensus sequence by in silico cloning strategy. Accordingly, these unigene consensus were studied by semi-quantitative reverse transcriptional (RT)-PCR with poorly differentiated squamous cell carcinoma tissues from 32 patients with primary nasopharyngeal carcinoma (NPC) and inflammatory tissues from 1b noncancerous individuals with chronic nasopharyngitis, as well as 4 NPC cell lines (CNE1bCNE2bHNE1 and HNE2). RESULTS: Forty-nine unigene ESTs were expressed equally in both NPC and NP, 8 were expressed neither in NPC nor in NP, 2 had higher expression in NPC than in NP, and 4 had lower expression (or undetectable) in NPC than in NP. The expression of Hs.27566 gene was detected in none of the NPC cell lines, and was significantly reduced or undetectable in NPC biopsies in comparison with NP (P<0.001). CONCLUSION: The differential expression of 63 novel genes located on chromosome 3p21-22 in NPC is mapped and 6 novel genes with differential expression in NPC tissues are identified.

Adult↗
PubMed2005

[Cloning of human KIAA1173 gene and biological characterization of transfected 6-10B cells].

OBJECTIVE: To establish a 6-10B cell line with stable expression of KIAA1173 gene and study the biological behaviors of the cells. METHODS: The total RNA was extracted from normal skeletal muscular tissues for cloning of KIAA1173 gene by means of RT-PCR which was subsequently introduced into pcDNA3.1 (+) vector. The recombinant eukaryotic expression vector pcDNA 3.1(+)-KIAA1173 was constructed and identified by endonuclease digestion and sequencing before transfection into 6-10B cells via lipofectamine with the empty vector as the control. The positive cell clones were obtained by G418 selection. Stable expression of KIAA1173 gene in the transfected 6-10B cells was determined by RT-PCR, in situ hybridization and immunocytochemistry, and the biological behaviors of the transfected cells were observed by MTT assay, cell invasion assay and tumorigenesis assay in nude mice. RESULTS: High expression of KIAA1173 at both mRNA and protein levels was observed in the transfected 6-10B cells. The capability of proliferation, invasion and tumorgenicity of the KIAA1173-transfected cells in nude mice was lowered in comparison with those of the cells transfected with pcDNA3.1 (+) vector (P<0.05). CONCLUSIONS: KIAA1173 genes may function as a potential tumor suppressor of nasopharyngeal carcinoma both in vitro and in vivo. The 6-10B cell line expressing KIAA1173 has been obtained, which can be helpful for further study of KIAA1173 gene.

Animals↗
PubMed2005

[Detection of bcl-2/IgH gene rearrangement in diffuse large B cell lymphoma by hemi-nested PCR].

OBJECTIVES: To explore a sensitive and specific method for detection of bcl-2/IgH gene rearrangement in diffuse large B cell lymphoma (DLBCL), and verify the credibility of the established method. METHODS: bcl-2/IgH hemi-nested PCR primers were designed using the professional primer design software. Fifty-two samples of pathologically diagnosed DLBCL and 10 fresh tonsil tissues were amplified using hemi-nested touch down-PCR to detect bcl-2/IgH gene rearrangement. The PCR products were cloned and sequenced. RESULTS: bcl-2/IgH gene rearrangement was detected in 6 of 52 DLBCL samples and 2 of 10 fresh tonsil tissues using one-way method. By using the hemi-nested PCR for the second round amplification, 5 of DLBCL were positive, but all of the fresh tonsil tissues were negative. The positive PCR products were sequenced and analyzed on the Internet, 3 of 8 cases obtained by one-way method were false positive, 5 positive cases amplified using hemi-nested PCR were all bcl-2/IgH gene rearrangement. PCR products of 3 false positive cases were homologous to BAC331191 and LLNLR-245D11 in human chromosome 19 and RP11-498P10 in chromosome 1. CONCLUSION: There are false positive results using common primers for detecting bcl-2/IgH gene rearrangement. The mechanism may be that highly homologous sequences to human genome exist in commonly used primers. The specificity of the diagnosis could be improved by hemi-nested PCR using the combination of primers we designed and the traditional ones.

Gene Rearrangement, B-Lymphocyte, Heavy Chain↗
PubMed2005

[Detection of KIAA1173 gene expression in nasopharyngeal carcinoma tissues and cell lines on tissue microarray].

BACKGROUND & OBJECTIVE: Although the molecular etiology of nasopharyngeal carcinoma (NPC) is still unknown, studies showed that there are NPC-associated tumor suppressor genes residing in chromosome 3p21-22. KIAA1173 gene, locates at 3p22.1, was characterized as a new carcinoma-related gene, while its correlation to tumorigenesis of NPC hasn't been reported yet. This study was to detect the expression of KIAA1173 gene in NPC tissues and cell lines, and investigate its involvement in NPC. METHODS: KIAA1173 gene fragment (354 bp) was cloned, and the cDNA probe was prepared. The expression of KIAA1173 gene in 73 nasopharyngeal tissue samples (including 41 specimens of NPC, 18 atypical hyperplasia epithelia, and 14 normal nasopharyngeal mucosa epithelia) and 6 NPC cell lines (including CNE1, CNE2, HNE1, HNE2, 6-10B, and 5-8F) were examined using tissue microarray technique by in situ hybridization (ISH). RESULTS: The positive rates of KIAA1173 mRNA were 21.9% (9/41) in NPC, 83.3% (15/18) in atypical hyperplasia epithelia, 92.8% (13/14) in normal nasopharyngeal mucosa epithelia, and 0 in all NPC cell lines. Its strongly positive rate was significantly lower in NPC than in atypical hyperplasia epithelia and normal mucosa epithelia (0 vs. 38.9% and 64.3%, P < 0.001). In 38 specimens of NPC with infiltrated lymphocytes, the positive rate of KIAA1173 mRNA was significantly lower in cancer cells than in tumor infiltrating lymphocytes (23.7% vs. 44.7%, P < 0.05); the expression of KIAA1173 in cancer cells was negatively related to that in tumor infiltrating lymphocytes (kappa = -0.337, P < 0.05). CONCLUSIONS: KIAA1173 gene is strongly expressed in normal nasopharyngeal mucosa epithelia, but down-regulated in NPC. It may be associated with the tumorigenesis of NPC. Tissue microarray;

Adult↗
PubMed2004

Investigation of T-cell receptor-gamma gene rearrangement in gastrointestinal lymphomas by PCR-SSCP analysis.

AIM: To analyze the characterization of T-cell receptor-gamma (TCR-gamma) gene rearrangement in the gastrointestinal lymphomas and evaluate the value of PCR-SSCP analysis in gastrointestinal lymphomas investigation. METHODS: TCR-gamma gene rearrangement segments of gastrointestinal lymphomas were cloned and sequenced. Single clone plasmid and mixed clone plasmids were subsequently submitted to PCR-SSCP analysis to investigate the relationship between the number of amplified clones and band patterns of the amplified products. The PCR products of TCR-gamma gene rearrangement of 40 gastrointestinal lymphomas were electrophoresed on agarose gels and the positive cases on agarose gels were studied by SSCP analysis. RESULTS: The sequencing showed that TCR-gamma gene rearrangement of the gastrointestinal lymphomas included functional gene and pseudogene with extensive variety in the junctional regions. In SSCP analysis, the number of the single-stranded bands was about two times of the number of amplified clones, and double-stranded band became broad with the increased number of the amplified clones. Thirteen of the 25 B-cell gastrointestinal lymphomas and 14 of the 15 gastrointestinal T-cell lymphomas were positive detected on agarose gel electrophoresis. Of the positive cases detected by SSCP analysis, 3 B-cell lymphomas and 13 T-cell lymphomas showed positive bands. The other cases showed only smears. The rearranged pattern included 13 monoallelic gene rearrangements and 3 biallelic or oligoclonal gene rearrangements. CONCLUSION: The pattern of TCR-gamma gene rearrangement in gastrointestinal lymphomas are similar to that of the nodular lymphomas. PCR-SSCP analysis for TCR-gamma gene rearrangement can be applied both for adjuvant diagnosis of gastrointestinal lymphomas and analysis of the gene rearrangement pattern. The ratio of TCR-gamma gene rearrangements occurred in T-cell gastrointestinal lymphomas is significantly higher than that in B-cell gastrointestinal lymphomas. The gene rearrangement pattern involves monoallelic and biallelic (or oligoclonal) gene rearrangement.

Base Sequence↗
PubMed2004

Involvement of increased stability of mitochondrial membrane potential and overexpression of Bcl-2 in enhanced anoxic tolerance induced by hypoxic preconditioning in cultured hypothalamic neurons.

The effects of hypoxic preconditioning (HP) on changes in mitochondrial membrane potential (MMP) and Bcl-2 expression in cultured hypothalamic neurons after severe anoxia were investigated. In the HP group, hypothalamic neurons, after a 4-day culture, were preconditioned daily under a hypoxic condition (1% O(2), 10 min) for 8 days; subsequently, the HP neurons and those in the control group (similarly cultured, but without HP) were exposed to 6 h of severe anoxia (0% O(2)). The preconditioned neurons had a higher survival rate and a lower lactate dehydrogenase leakage, compared with the control group. Although HP did not prevent the degradation of MMP during severe hypoxia, preconditioned neurons exhibited a higher level of MMP than that of the control group. Increased expression of Bcl-2 was also observed in the preconditioned hypothalamic neurons. These results suggest that HP enhances the hypoxic tolerance of hypothalamic neurons, and the underlying mechanisms may be related to the increased stability of MMP and the overexpression of Bcl-2 induced by HP.

Animals↗
PubMed2004

Control of Listeria monocytogenes in a biofilm by competitive-exclusion microorganisms.

Biofilms from drains in food processing facilities with a recent history of no detectable Listeria monocytogenes in floor drains were cultured for microorganisms producing antilisterial metabolites. A total of 413 microbial isolates were obtained from 12 drain biofilm samples and were assayed at 15 and 37 degrees C for activities that were bactericidal or inhibitory to L. monocytogenes, by two agar plate assays. Twenty-one of 257 bacterial isolates and 3 of 156 yeast isolates had antilisterial activity. All 24 isolates which produced metabolites inhibitory to L. monocytogenes were assayed for antilisterial activity in coinoculated broth cultures containing tryptic soy broth with yeast extract (TSB-YE). A five-strain mixture of 10(3) CFU of L. monocytogenes/ml and 10(5) CFU of the candidate competitive-exclusion microorganism/ml was combined in TSB-YE and incubated at 37 degrees C for 24 h, 15 degrees C for 14 days, 8 degrees C for 21 days, and 4 degrees C for 28 days. Substantial inhibition of L. monocytogenes growth (4 to 5 log CFU/ml) was observed for nine bacterial isolates at 37 degrees C, two at 15 and 8 degrees C, and three at 4 degrees C. The inhibitory isolates were identified as Enterococcus durans (six isolates), Lactococcus lactis subsp. lactis (two isolates), and Lactobacillus plantarum (one isolate). The anti-L. monocytogenes activity of these isolates was evaluated in biofilms of L. monocytogenes on stainless steel coupons at 37, 15, 8, and 4 degrees C. Results revealed that two isolates (E. durans strain 152 and L. lactis subsp. lactis strain C-1-92) were highly inhibitory to L. monocytogenes (growth inhibition of >5 log(10) CFU of L. monocytogenes/cm(2)). These two bacterial isolates appear to be excellent competitive-exclusion candidates to control L. monocytogenes in biofilms at environmental temperatures of 4 to 37 degrees C.

Biofilms↗
PubMed2004

Influence of freezing and freezing plus acidic calcium sulfate and lactic acid addition on thermal inactivation of Escherichia coli O157:H7 in ground beef.

Undercooked ground beef is a leading vehicle for acquiring Escherichia coli O157:H7 infections through consumption of foods. Studies have been performed to determine the effect of freezing and the combined effect of freezing and addition of a mixture of 20% acidic calcium sulfate (final concentration of 0.4% in ground beef) and 10% lactic acid (final concentration of 0.2% in ground beef) (ACS-LA) on the thermal sensitivity of E. coli O157:H7 in ground beef. Five strains of E. coli O157: H7 were separately inoculated into ground beef and held at 5 degrees C for up to 10 days or -20 degrees C for up to 3 weeks then heated at 57, 60, 62.8, 64.3, and 68.3 degrees C to determine rates of thermal inactivation. Results revealed that D-values (decimal reduction times) at equivalent temperatures for four of five E. coli O157:H7 strains were less in the previously frozen than in the refrigerated ground beef and that strains isolated from ground beef in 1993 and 1994 were generally more sensitive to thermal inactivation than those isolated in 1999 and 2000. Only one strain of E. coli O157:H7 was used to determine the effect of ACS-LA in previously frozen or refrigerated ground beef on rates of thermal inactivation. The addition of ACS-LA to ground beef at 20 ml/kg increased the thermal sensitivity of E. coli O157:H7 in both previously frozen and refrigerated ground beef, with greatest rates of inactivation occurring in previously frozen ground beef containing ACS-LA. D-values at 57 degrees C obtained for E. coli O157:H7 in previously refrigerated and frozen ground beef containing ACS-LA and ACS-LA diluted by half were significantly (P < 0.05) less than those obtained in ground beef with no ACS-LA added. D-values at 60 and 62.8 degrees C were consistently less in ACS-LA treated ground beef, but for most treatments the results were not significantly (P > 0.05) different than the controls. Results revealed that the addition of ACS-LA to ground beef, whether frozen or refrigerated, can reduce the temperature or time required to kill E. coli O157:H7 during heating.

Animals↗
PubMed2004

Touch-down PCR and single-strand conformation polymorphism for detecting clonal T cell receptor gamma gene rearrangement in lymphoid leukemia.

OBJECTIVE: To explore the value of detecting clonal T cell receptor gamma (TCR-gamma) gene rearrangement with touch-down PCR and single-strand conformational polymorphism analysis (SSCP) in the diagnosis of lymphoid leukemia. METHODS: The DNA of peripheral blood leucocytes from lymphoid leukemia patients were extracted for amplification of the TCR-gamma gene rearrangement with the consensus primers and touch-down PCR. The PCR products were analyzed by agarose gel electrophoresis, direct DNA sequencing and SSCP analysis. The positive control cell line DNA was mixed in different proportions with the DNA extracted from reactive lymphoid tissue to test the sensitivity of the touch-down PCR. RESULTS: Fifteen of 18 T lymphoid leukemia and 2 of the 4 B lymphoid leukemia patients were identified to be positive by agarose electrophoresis. The positive PCR products were further analyzed by SSCP analysis, which showed discrete bands. Direct DNA sequencing confirmed the clones to be TCR-gamma gene rearrangement, and the sensitivity of touch-down PCR was 1%. CONCLUSION: Consensus primers for studying TCR-gamma gene rearrangement in combination with touch-down PCR can effectively amplify the clonal TCR-gamma gene rearrangement in T lymphoid leukemia.

Gene Rearrangement, gamma-Chain T-Cell Antigen Rec↗
PubMed2004

[Detection of IgH gene rearrangement in Reed-Sternberg cells microdissected from classical Hodgkin's lymphoma].

OBJECTIVE: To study the origins and clonality of Hodgkin and Reed-Sternberg (H/RS) cells and their relations with the background lymphocytes in classical Hodgkin's lymphoma. METHOD: IgH gene rearrangement was detected in paffin-embedded tissues from 33 patients with Hodgkin's lymphoma and a further analysis of the gene rearrangement was conducted in 6 of the positive cases identified after immunostaining of the sections with B-cell-specific activator protein (BSAP) followed by microdissection of the positivity labeled H/RS cells and background lymphocytes. RESULTS: IgH gene rearrangement was identified in 16 of the 33 cases. Microdissection of the lymphoma tissues was successfully performed in the 6 positive cases, and of the 19 tubes of H/RS cells obtained, 14 presented clonal bands of the rearrangement, and difference in cell numbers did not significantly influence the positive rate (P=0.290); in the 12 tubes of microdissected background lymphocytes obtained, 2 were positive for the rearrangement, and the positive rates for the rearrangement significantly differed between H/RS cells and the background lymphocytes (P=0.002). CONCLUSION: The results appear to support the hypothesis that H/RS cells originates from B cells, and a part of the background lymphocytes may possess neoplastic proliferation potentials to function as the precursors of H/RS cells.

Adolescent↗
PubMed2004

Transcatheter arterial chemoembolization of oral squamous-cell carcinoma: a clinicopathological observation.

OBJECTIVE: To evaluate the therapeutic efficacy of transcatheter arterial chemoembolization (TACE) for advanced oral carcinoma by observing the pathological changes of the carcinoma tissues after the interventional therapy. METHODS: Twenty cases of advanced oral carcinoma involving the tongue (16 cases), gingiva (2 cases) and the floor of the mouth (2 cases) were enrolled in this study. Intubation with Seldinger's technique from the femoral artery to the external carotid artery was performed in all the cases. With the assistance of digital subtracting angiography (DSA), cisplatin, adriacin and mitomycin C were injected through the branches of the external carotid artery into the involved tissues with embolization using gelatin sponge. Surgical resection of the tumor was performed 1 to 4 weeks after TACE, and the specimens were observed under light microscope and transmission electron microscope. RESULTS: Significant changes occurred in the carcinoma tissues, manifested by reduced carcinoma cells, karyopyknosis, vacuolar degeneration and focal coagulation necrosis. The disintegrated carcinoma nests were encapsulated and underwent organization by hyperplastic fibrous connective tissues with inflammatory cell infiltration. The connective structures between the carcinoma cells disappeared and resulted in broadened intercellular space. CONCLUSION: Preoperative administration of arterial chemoembolization may cause degeneration and necrosis of oral carcinoma, which can be helpful to distinguish intraoperatively the carcinoma from normal tissues; as for the inoperable cases, TACE may inhibit the tumor growth and prolong the survival of the patients.

Adult↗
PubMed2004

[Expressions of Fas/FasL and granzyme B in oral lichen planus and their significance].

OBJECTIVE: To define the association of the expressions of Fas/FasL and granzyme B with cell apoptosis in oral lichen planus (OLP) and progression of the disease. METHOD: Immunohistochemical method and TUNEL were employed to study the expressions of Fas, FasL and granzyme B and cell apoptosis in 50 OLP cases (including 20 cases of atrophic-erosive OLP and 30 nonerosive OLP cases) and 10 normal oral mucosa specimens. RESULTS: Compared with the control group, the OLP cases showed increased apoptotic index (AI, 95.32+/-28.99) in the epithelial layer and the decreased AI (35.12+/-9.89) in the lamina propria (P<0.05), with the apoptotic cells confined within the basal or suprabasal cell layer instead of the superficial cell layer in the control group. The positivity rates of FasL and granzyme B expression were both 68/ in the lamina propria of the OLP cases, remarkably higher than those in the normal control group (P<0.05); significantly higher rates were noted in atrophic-erosive than in nonerosive OLP cases (P<0.05). CONCLUSIONS: The AI significantly differs between the epithelial layer and lamina propria in OLP cases, for which the expressions of Fas, FasL and granzyme B might be held responsible. The over-expressions of FasL and granzyme B are closely related to the progression of OLP.

Adult↗
PubMed2003

Molecular diagnosis of primary mediastinal B cell lymphoma identifies a clinically favorable subgroup of diffuse large B cell lymphoma related to Hodgkin lymphoma.

Using current diagnostic criteria, primary mediastinal B cell lymphoma (PMBL) cannot be distinguished from other types of diffuse large B cell lymphoma (DLBCL) reliably. We used gene expression profiling to develop a more precise molecular diagnosis of PMBL. PMBL patients were considerably younger than other DLBCL patients, and their lymphomas frequently involved other thoracic structures but not extrathoracic sites typical of other DLBCLs. PMBL patients had a relatively favorable clinical outcome, with a 5-yr survival rate of 64% compared with 46% for other DLBCL patients. Gene expression profiling strongly supported a relationship between PMBL and Hodgkin lymphoma: over one third of the genes that were more highly expressed in PMBL than in other DLBCLs were also characteristically expressed in Hodgkin lymphoma cells. PDL2, which encodes a regulator of T cell activation, was the gene that best discriminated PMBL from other DLBCLs and was also highly expressed in Hodgkin lymphoma cells. The genomic loci for PDL2 and several neighboring genes were amplified in over half of the PMBLs and in Hodgkin lymphoma cell lines. The molecular diagnosis of PMBL should significantly aid in the development of therapies tailored to this clinically and pathogenetically distinctive subgroup of DLBCL.

Adult↗
PubMed2003

Reduction of Campylobacter jejuni on poultry by low-temperature treatment.

Campylobacter jejuni is a leading cause of acute bacterial gastroenteritis in the United States, with epidemiologic studies identifying poultry as a leading vehicle in human infection. Studies were conducted to determine rates of C. jejuni inactivation on poultry exposed to different cooling and freezing temperatures. A mixture of three strains of C. jejuni originally isolated from poultry was inoculated onto chicken wings at ca. 10(7) CFU/g. The results of the study revealed that the storage of wings at -20 and -30 degrees C for 72 h reduced the population of C. jejuni on wings by 1.3 and 1.8 log10 CFU/g, respectively. The results with regard to long-term freezing for 52 weeks revealed C. jejuni reductions of ca. 4 and 0.5 log10 CFU/g on wings held at -20 and -86 degrees C, respectively. Protocols were developed to superchill wings in Whirl-Pak bags with liquid nitrogen at -80, -120, -160, and -196 degrees C such that the internal portion of each wing quickly reached -3.3 degrees C but did not freeze. The results with regard to the superchilling of wings at different temperatures for 20 to 330 s (the time required for the wings to reach an internal temperature of -3.3 degrees C) revealed C. jejuni reductions of 0.5 log10 CFU/g for wings held at -80 degrees C, 0.8 log10 CFU/g for wings held at -120 degrees C, 0.6 log10 CFU/g for wings held at -160 degrees C, and 2.4 log10 CFU/g for wings held at -196 degrees C. The superchilling of wings to quickly cool meat to -3.3 degrees C (internal temperature) can substantially reduce C. jejuni populations at -196 degrees C when the wings are submerged in liquid nitrogen, but not at -80 to -160 degrees C when the wings are treated with vapor-state liquid nitrogen. The results of this study indicate that freezing conditions, including temperature and holding time, greatly influence the rate of inactivation of C. jejuni on poultry. The conditions used in the poultry industry to superchill poultry to a nonfrozen-state internal temperature are not likely to substantially reduce Campylobacter populations on fresh products.

Animals↗
PubMed2003

Pathogenicity of enterohemorrhagic Escherichia coli in neonatal calves and evaluation of fecal shedding by treatment with probiotic Escherichia coli.

The pathogenicity and fecal shedding of enterohemorrhagic Escherichia coli (EHEC) O26:H11, O111:NM, and O157:H7 were compared in calves (< 1 week of age) with or without prior treatment with probiotic bacteria (competitive exclusion E. coli). Three groups of 12 to 14 calves were used for these treatments. Half of the calves in each group were perorally administered 10(10) CFU of probiotic bacteria per calf, and, 2 days thereafter, 10(8) CFU of a five-strain mixture with one of the three EHEC serotypes per calf were administered to each calf. None of the EHEC serotypes caused clinical disease,and neither gross nor microscopic lesions attributable to EHEC were detected in control or probiotic-treated calves at necropsy. In calves administered E. coli O157:H7, fecal shedding was greatly reduced (> 6 log10 CFU/g) by 8 days after administration, and there was no significant difference (P > 0.05) in fecal shedding of E. coli O157:H7 between probiotic-treated and untreated control groups at that time. In contrast, control calves perorally administered E. coil of serotypes O111:NM or O26:H11 continued to shed substantial populations (10(2.1) to 10(6) CFU/g of feces and 10(2.5) to 10(4.9) CFU/g of feces, respectively) throughout 7 days postadministration of EHEC. In both groups administered either E. coli O111:NM or O26:H11, significantly less (P < 0.05) EHEC was isolated from feces at 7 days postadministration of EHEC and at necropsy from theprobiotic-treated group than from the untreated control group. Overall, neonatal calves shed in the feces from 1 to 7 days following peroral administration of EHEC greater populations of E. coli O111:NM and O26:H111 than E. coli O157:H7. In addition, treatment of calves with probiotic E. coli reduced fecal shedding of E. coli O111:NM and O26:H11 in most calves.

Animals↗
PubMed2003

Fecal shedding of enterohemorrhagic Escherichia coli in weaned calves following treatment with probiotic Escherichia coli.

The fecal shedding and pathogenicity of enterohemorrhagic E. coli (EHEC) O26:H11, EHEC O111:NM, and EHEC O157:H7 in weaned calves (8 to 10 weeks of age) were compared with and without treatment with a three-strain mixture of probiotic bacteria (competitive-exclusion E. coli). Three groups of 12 calves were each perorally given a five-strain mixture of one of the EHEC serotypes (10(10) CFU of total bacteria per calf). Seventy-two hours later, six calves from each group were each administered 10(10) CFU of probiotic bacteria. None of the EHEC serotypes caused significant clinical disease, although a few calves developed mild transient diarrhea or pyrexia. Gross or microscopic lesions attributable to EHEC were not detected in control or probiotic-treated calves at necropsy. For probiotic-treated calves given E. coli O157:H7 and for probiotic-treated calves given E. coli O111:NM, fecal shedding was reduced compared with that for untreated calves. For the probiotic-treated calves given E. coli O157:H7, the reductions in fecal shedding on days 8, 12, 14, 16, 20, 22, 28, and 30 after peroral administration were statistically significant (P<0.05). For probiotic-treated calves given E. coli O111:NM, there were statistically significant reductions (P<0.05) in fecal shedding on days 6, 8, 10, and 12. In contrast, there was no reduction in fecal shedding for calves administered E. coli O26:H11 and treated with the probiotic bacteria. In fact, calves in both the treated and the nontreated groups continued to shed large populations of E. coli O26:H11 throughout the 32-day trial. At necropsy, E. coli O157:H7 was isolated from five of six untreated calves and from only two of six probiotic-treated calves. E. coli O111:NM was isolated from four of six untreated calves at necropsy and from two of six probiotic-treated calves. However, E. coli O26:H11 was isolated from five of six untreated calves and from all six probiotic-treated calves. The results obtained in this study indicate that probiotic E. coli substantially reduced or eliminated fecal shedding of E. coli O157:H7 and E. coli O111:NM 8 to 30 days and 6 to 12 days after the administration of the probiotic culture, respectively, and reduced the persistence of E. coli O157:H7 in the gastrointestinal tract at necropsy (31 to 33 days after the administration of the probiotic culture). The probiotic E. coli did not reduce fecal shedding or gastrointestinal persistence of E. coli O26:H11.

Animals↗
PubMed2003

Expressions of latent membrane protein 1, p53 and bcl-2 proteins and their significance in Hodgkin's lymphoma.

OBJECTIVE: To study the expressions of latent membrane protein 1 (LMP1), p53 and bcl-2 proteins and investigate their significance in the pathogenesis of Hodgkin's lymphoma. METHODS: Immunohistochemical staining was used to examine the expressions of LMP1, bcl-2, and p53 proteins in 31 paraffin-embedded tissue samples from Hodgkin's lymphoma. RESULT: The positivity rates of LMP1, p53 and bcl-2 proteins were 58.1% (18/31), 61.3% (19/31) and 35.5% (11/31), respectively, showing a statistically significant difference between the expressions of the former 2 proteins. CONCLUSION: p53 may be involved as an important agent in the pathogenesis of Hodgkin's lymphoma induced by LMP1, whereas bcl-2 appears unrelated to the development of this disease.

Adult↗