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Biomedical subjects

Yan Yu

Publications and source records attributed to Yan Yu.

At least 55 records · Page 3Linked to original sources
PubMed2005

[Effects of ethyl pyruvate on splenocyte proliferation and apoptosis in burn rats with delayed resuscitation].

OBJECTIVE: To investigate the effects of ethyl pyruvate (EP) on splenocyte proliferation and apoptosis in burn rats with delayed resuscitation, and its potential underlying mechanism. METHODS: Seventy two male Wistar rats were randomly divided into sham-scalded control group (n=24), scald group (n=24), and scald with EP treatment group (n=24). Animals were sacrificed on days 1, 3, and 5 postburn, and spleen samples were collected to determine splenocyte proliferation and apoptosis. RESULTS: Splenic lymphocyte proliferation response to T cell mitogen, concanavalin A (Con A), as significantly depressed from 1 to 5 days after burn injury (all P<0.05). Meanwhile, burn injury resulted in a marked increase in splenic CD3(+)CD4(+)T lymphocyte apoptosis in comparison with that in sham-scalded controls on day 1 postburn (P<0.05). Treatment with EP after burns resulted in a dramatic restoration of lymphocyte proliferation response and reduction of splenic CD3(+)CD4(+)T lymphocyte apoptosis compared with scald group (P<0.05). CONCLUSION: Administration of EP can markedly improve the splenocyte proliferation response and inhibit splenic CD3(+)CD4(+)T lymphocyte apoptosis in thermally injured rats.

Animals↗
PubMed2005

[Influence of Xinqin tablets on guinea-pig nasal hypersensitivity].

OBJECTIVE: To study the influence of Xinqin tablets on guinea-pig nasal hypersensitivity. METHOD: 2,4-Toluene Diisocyanate (TDI) was selected as antigen and used in nose to establish guinea-pig allergic rhinitis. The effects of Xinqin tablets on symptoms of nasal hypersensitivity in guinea-pigs, histamine content of nasal mucosa and activity of nitric oxide synthase (NOS) were examined. RESULT: Xinqin tablets could significantly relieve the pathological symptoms of nasal hypersensitivity in guinea-pig, reduce histamine content of nasal mucosa and inhibit the activity of nitric oxide synthase. CONCLUSION: Xinqin tablets have significant effect on nasal hypersensitivity, and prevent the occurrence of allergic rhinitis.

Animals↗
PubMed2005

[Association of gene HLA-class I with leukemia].

This study was aimed to investigate the corelation between the HLA (human leukocyte antigen) genes and susceptibility of leukeamia. 605 patients with leukeamia including 189 ALL, 184 AML and 232 CML were selected for this investigation. 900 normal umbilical cord blood samples from umbilical cord blood bank were used as control population compared to the leukemia patients. HLA-A, B, C typing was done by polymerase chain reaction with sequence-specific primers (SSP-PCR). The results showed that frequencies of HLA-A*26, A*68, B*56 in ALL patients were higher (4.46%, 2.65%, 1.17%), as compared with controls (2.31%, 0.95%, 0.22%), HLA-CW*06 in ALL patients was lower (3.64%), as compared with control (11.65%). In AML patients HLA-A*01 (9.41%), B*37 (3.60%) was higher and A*33 (3.60%), B*51 (4.73%) were lower than those in controls (3.57%, 1.75% and 7.64%, 7.93%). HLA-A*32, B*27, B*44, B*54, B*55 (2.18%, 3.96%, 5.06%, 4.63%, 2.84%) in CML patients were higher than those in control (0.84%, 2.04%, 3.07%, 2.44%, 1.29%). These results suggested that positive association may exist between certain HLA-class I genes and leukemias. These preliminary data may be useful for further study on the mechanisms of leukemia pathogenesis.

Adolescent↗
PubMed2005

[Effect of heat shock protein 70 on nuclear factor-KappaB/inhibitor protein-alpha of nuclear factor-KappaB in brain edema induced by infection in rat].

OBJECTIVE: To study the effect of heat shock protein 70 (HSP70) on activation of nuclear factor-KappaB (NF-KappaB) and degradation of inhibitor KappaB-alpha protein (I-Kappa B alpha) in brain edema induced by Pertussis bacilli infection in rats. METHODS: Brain edema was induced by injection of Pertussis bacilli suspension via the left internal carotid artery. Seventy-two Sprague-Dawley rats were divided randomly into brain edema group, pretreatment with heat shock group, and normal saline control group. The rats were sacrificed 4, 8 and 24 hours after injection of Pertussis bacilli and normal saline, respectively. HSP70 expression and the degradation of I-Kappa B alpha were assayed in all animals with Western blot analysis. Electrophoretic mobility shift assay (EMSA) was performed to assess NF-KappaB activation of nuclear extract of neurones. RESULTS: The results showed that HSP70 expression was significantly increased in heat shock group compared with control group and brain edema group. The activity of NF-KappaB started to increase at 2 hours in brain edema group and peaked at 24 hours. The expression of I-Kappa B alpha began to decrease at 2 hours and reached the lowest level at 24 hours. In heat shock group the activity of NF-KappaB complexes was lower than that in brain edema group, and the expression of I-Kappa B alpha higher than that in brain edema group at corresponding time points. CONCLUSION: HSP70 shows a protective effect on development of brain edema as its expression increases. The mechanism might be associated with its inhibitory effect on degradation of I-Kappa B alpha and activation of NF-KappaB.

Animals↗
PubMed2005

[The new progress of the study about volatile oil of the angelica].

To summarize the new progress of the study about volatile oil of the angelica, including the distillable methods, the analysis of the chemical components, the pharmacological effects and the clinical applications. We tracked and searched the correlative references and study reports about volatile oil of the angelica in CNKI data base(1994-2004) and Medline data base (1997-2004). We summarized and compared the different distillable methods of volatile oil of the angelica, meanwhile we summarized many study reports about the analysis of the chemical components of volatile oil of the angelica and it's pharmacological effects, including the toxicity of the volatile oil and it's effects on the uterus smooth muscle, cardiovascular system, respiratory system, central nerve system and immune system. Finally we summarized the clinical application of the volatile oil of the angelica. There are three distillable methods of volatile oil of the angelica . The harvest efficiency of volatile oil is different with different distillable methods. The chemical components are very complicated and the new chemical components are separated and identified. The volatile oil has bidirectional effects on the uterus smooth muscle. It can inhibit the contraction of the uterus smooth muscle induced by different mechanisms. Meanwhile it can depress the blood pressure and ameliorate the cardiac ischemia. The volatile oil can resist the arrhythmia and asthma, restrain the central system, improve the immune function. Nowadays the volatile oil of the angelica is applied to therapy the dysmenorrhea and disorder of the catamenia. The chemical components of the volatile oil of the angelica are very complicated, moreover the pharmacological effects of the volatile oil are comprehensive. People make the new progress of the study about volatile oil of the angelica.

4-Butyrolactone↗
PubMed2005

[The role of Janus kinase-signal transducer and transcription activator pathway in the regulation of synthesis and release of lipopolysaccharide-induced high mobility group box-1 protein].

OBJECTIVE: To investigate the role of Janus kinase-signal transducer and transcription activator (JAK-STAT) pathway in the regulation of synthesis and release of lipopolysaccharide-induced high mobility group box-1 protein (HMGB1). METHODS: Peritoneal macrophages harvested from male Wistar rats were incubated for 3 days before the experiment. The activation of Janus kinase-2 (JAK2), signal transducer and activator of transcription-1 (STAT1) and STAT3 was observed before and 10, 30, 60 and 120 mins after LPS stimulation (4 determinations at each time point) and it was expressed as A value (absorption). In addition, the cells were divided into normal control, LPS stimulation, JAK2 inhibition (with AG490 treatment 2 hours before LPS stimulation), STAT1 inhibition (with fludarabine treatment 2 hours before LPS stimulation) and STAT3 inhibition (with rapamycin treatment 2 hours before LPS stimulation) groups. The cells in all groups except control group were stimulated with LPS 3 days after culture. The expression of HMGB1 gene and its protein release in each group were determined for 4 times and were expressed as A value. RESULTS: LPS could activate JAK2, STAT1 and STAT3 within 2 hours, especially the activation of STAT3 appeared more quickly, peaking at 10 minutes after LPS stimulation (7.47 +/- 0.56). Pretreatment with the inhibitors of JAK-STAT pathway could markedly reduce the expression of HMGB1 mRNA (P < 0.01), but exerted no effect on HMGB1 release. CONCLUSION: JAK-STAT pathway can be activated early during endotoxin challenge, and it may play a role in the regulation of HMGB1 synthesis.

Animals↗
PubMed2005

[Study on the effect of embryo extraction of chicken on improving the hemophthisis of malnutrition in rat].

OBJECTIVE: To study the effect of embryo extraction of chicken on improving the hemophthisis of malnutrition in rats. METHODS: The rats model of hemophthisis was established with the method of feeding the low iron feed and blood letting in caudal vein. The effect of embryo extraction of chicken on the biochemistry index of hemoglobin, serum transferrin saturation, serum ferritin, serum iron and organize iron were observed after the model rats were fed with the embryo extraction of chicken four weeks. RESULTS: The hemoglobin, serum transferrin saturation, serum ferritin, and serum iron can be increased remarkably by embryo extraction of chicken in the model of hemophthisis of rats. There is no side effect on the weight in rats. CONCLUSION: The embryo extraction of chicken holds a good function on improving the hemophthisis of malnutrition in rats.

Anemia, Iron-Deficiency↗
PubMed2004

Structural flexibility in the Burkholderia mallei genome.

The complete genome sequence of Burkholderia mallei ATCC 23344 provides insight into this highly infectious bacterium's pathogenicity and evolutionary history. B. mallei, the etiologic agent of glanders, has come under renewed scientific investigation as a result of recent concerns about its past and potential future use as a biological weapon. Genome analysis identified a number of putative virulence factors whose function was supported by comparative genome hybridization and expression profiling of the bacterium in hamster liver in vivo. The genome contains numerous insertion sequence elements that have mediated extensive deletions and rearrangements of the genome relative to Burkholderia pseudomallei. The genome also contains a vast number (>12,000) of simple sequence repeats. Variation in simple sequence repeats in key genes can provide a mechanism for generating antigenic variation that may account for the mammalian host's inability to mount a durable adaptive immune response to a B. mallei infection.

Animals↗
PubMed2004

[Effects of escharectomy during shock stage on tissue high mobility group box-1 expression and balance of pro-/anti-inflammatory response in rats after severe thermal injury].

OBJECTIVE: To investigate the effects of escharectomy during shock stage on tissue high mobility group box-1 protein (HMGB1) expression and balance of pro-/anti-inflammatory cytokines, and to elucidate the potential mechanism underlying beneficial effect of early escharectomy after severe burns. METHODS: Wistar rats inflicted by 30% full-thickness thermal injury were randomly divided into thermal injury group, 24 h escharectomy group and 72 h escharectomy group, in which escharectomy were performed at 24 and 72 h postburn, respectively. Gene expression of HMGB1, interleukin-10 (IL-10), and tumor necrosis factor-alpha (TNF-alpha) in liver and lungs was detected with reverse-transcription PCR, and protein levels of IL-10 and TNF-alpha in liver and lung tissues were measured by ELISA. The plasma AST and ALT contents, and pulmonary myeloperoxidase (MPO) activity were also assayed. RESULTS: The mRNA expression of HMGB1 and TNF-alpha in liver and lungs was up-regulated on postburn day 2, with IL-10 over-expression on postburn day 8. In the 24 h escharectomy group, HMGB1 and TNF-alpha mRNA expression in liver and lungs was down-regulated on postburn day 4, and IL-10 expression returned to normal range on postburn day 8, while the down-regulation of HMGB1, TNF-alpha and IL-10 were not noted in the 72 h escharectomy group. There were two peaks in liver TNF-alpha protein levels appearing on postburn days 2 and 8, respectively, with an unexpected marked decrease on day 4 in thermal injury controls, yet liver TNF-alpha levels maintained in normal range in animals of 24 h and 72 h escharectomy groups. The ratios of TNF-alpha to IL-10 protein levels in liver tissue were significantly increased on postburn days 2 and 4 (P = 0.0001 and 0.002, respectively), while escharectomy during shock stage markedly reduced hepatic TNF-alpha to IL-10 ratios (P = 0.0008 and 0.040, respectively). No significant changes in TNF-alpha protein levels in lung tissue were observed. Additionally, plasma AST as well as ALT contents, and pulmonary MPO activity were markedly decreased on postburn days 4 and 8 in the 24 h escharectomy group compared to the 72 h escharectomy group or thermal injury controls (P < 0.05). CONCLUSIONS: Escharectomy during burn shock stage could inhibit the over-expression of both early and late inflammatory mediators, and maintain the balance of pro-/anti-inflammatory response, thereby improving multiple organ functions in rats following severe burns.

Alanine Transaminase↗
PubMed2004

Differential expression of osteogenic factors associated with osteoinductivity of human osteosarcoma cell lines.

Differential expression of multiple osteogenic factors may be responsible for the different osteoinductivity of osteosarcoma cell lines. We compared in vivo osteoinductivity of human osteosarcoma cell lines (Saos-2 vs. U-2 OS) in nude mice, and their in vitro expression of various osteogenic factors of protein level by quantitative immunocytochemistry and mRNA level by RT-PCR and/or in situ hybridization. Saos-2 cells, but not U-2 OS, were osteoinductive in vivo. Significantly higher expression (independent t-test, all p < 0.005) of osteogenic factors were observed in Saos-2 cells compared with U-2 OS, which included bone morphogenetic proteins (particularly BMPs-2, 3, 4, and 7), transforming growth factor-beta (TGF-beta), BMP receptor (BMPR)-1A, receptor-regulated Smads (R-Smads), Smads 1, 2, and 5, and common-mediator Smad (Co-Smad), Smad 4. In contrast, U-2 OS cells expressed higher levels of inhibitory Smad 6 (I-Smad) protein than Saos-2 cells (p < 0.001). These results suggest that a combination of osteogenic factors (BMPs, TGF-beta, BMPRs, and R/Co-Smads) against I-Smad may play important roles in the Saos-2 cell osteoinductivity. This may have a clinical implication in selecting key osteogenic factors for combined therapy for bone defect diseases. The characterized cell lines can be used as positive and negative controls for the assessments of both in vitro and in vivo bone formation capabilities of designed tissues or biomaterials.

Animals↗
PubMed2004

[Effects of extracellular signal-regulated kinase inhibition by AG126 on tissue tumor necrosis factor-alpha expression and multiple organ dysfunction in rats with postburn Staphylococcus aureus sepsis].

OBJECTIVE: To investigate the effects of extracellular signal-regulated kinase (ERKs) inhibition by AG126 on tissue tumor necrosis factor-alpha (TNF-alpha) expression and multiple organ dysfunction in rats with postburn Staphylococcus aureus sepsis and its potential signal regulating mechanism. METHODS: To reproduce postburn sepsis model, male Wistar rats were inflicated with 20% total body surface area third-degree scald followed by Staphylococcus aureus challenge. 34 rats were randomly divided into four groups as follows: normal control group (n = 6), scald control group (n = 6), postburn sepsis group (n = 12), and AG126 treatment group (n = 10). Tissue samples from the liver, kidneys and lungs were collected to determine phosphorylated ERKs by Western blot analysis, and TNF-alpha mRNA expression as well as its protein levels. RESULTS: It was revealed that phosphorylated ERKs in the liver, lungs, and kidneys from postburn septic animals were up-regulated rapidly at 0.5 - 2.0 hours, being 1.94-fold (P < 0.05), 2.86-fold (P < 0.01), and 1.41-fold at 2.0 hours compared to normal controls, respectively. Treatment with AG126 could significantly reduce phosphorylated ERKs in lung tissue by 70.6% (P < 0.01) at 2.0 hours postburn sepsis, and almost completely inhibited ERKs activation in the liver and kidneys at various time points. Meanwhile, both TNF-alpha mRNA and protein expressions in the liver, lungs, and kidneys were significantly decreased in AG126-treated group following septic challenge (P < 0.05 or 0.01). In addition, 2.0 hours after Staphylococcus aureus infection, treatment with AG126 markedly improved hepatic and renal function parameters, including serum ALT, AST, Cr, as well as BUN levels (P < 0.05 or 0.01), together with significant decrease in pulmonary myeloperoxidase activity, compared to those without AG126 treatment. CONCLUSION: These data suggested that ERKs signal transduction might be involved in the pathogenesis of systemic inflammatory response and multiple organ dysfunction in postburn gram-positive bacterial sepsis. Early treatment with AG126 could significantly down-regulate TNF-alpha mRNA expression as well as protein levels in vital organs and attenuate multiple organ dysfunction induced by scald injury combined with Staphylococcus aureus challenge.

Animals↗
PubMed2004

Spinal fusion using an autologous growth factor gel and a porous resorbable ceramic.

Augmenting healing through a single application of an exogenous growth factor or bone morphogenetic protein is not a new concept. The use of autologous growth factors through platelet isolation and concentration provides multiple endogenous growth factors to the healing site. A posterolateral fusion model in aged sheep (5- to 6-year-old ewes) was used to examine the effects of the addition of growth factors through autologous platelet isolation on the biomechanic and histologic properties of the fusion using a resorbable coral bone graft substitute. At 6 months the combination of autologous growth factors to the Pro Osteon 500R plus aspirated bone marrow resulted in the greatest bending stiffness but not ultimate load. Autologous growth factors can be isolated from platelets and concentrated to provide multiple growth factors to the fusion site to aid in spinal fusion.

Animals↗
PubMed2004

The limits of log-ratios.

BACKGROUND: DNA microarray assays typically compare two biological samples and present the results of those comparisons gene-by-gene as the logarithm base two of the ratio of the measured expression levels for the two samples. RESULTS: Because of the fixed dynamic range of fluorescence and other detection systems, there is a limit to the range of comparisons that can be made using any array technology, and this must be taken into account when interpreting the results of any such analysis. CONCLUSIONS: The dynamic range of microarray data collection systems results in limits in the comparative analyses that can be derived from such measurements and suggests that optimal results can be obtained by making measurements that avoid the boundaries of that dynamic range.

Algorithms↗
PubMed2004

Tissue lipopolysaccharide-binding protein expression in rats after thermal injury: potential role of TNF-alpha.

Recent studies have suggested that levels of lipopolysaccharide-binding protein (LBP) might play a harmful role by up-regulating the host's sensitivity to endotoxin. Our previous studies demonstrated that local endotoxin could up-regulate LBP expression after acute insults, however, the definite molecular mechanisms downstream of endotoxin action remain unclear. This study investigates whether tumor necrosis factor (TNF-alpha) might be responsible for the LBP formation during endogenous endotoxemia postburn. Wistar rats were anesthetized, and a 35% TBSA full-thickness burn was created. Animals were randomly divided into normal control, thermal injury and anti-TNF-alpha mAb treatment group. A significant elevation of plasma endotoxin concentration was observed after acute insults. TNF-alpha levels in plasma also rapidly increased after thermal injury. Meanwhile, LBP mRNA expression markedly increased in liver, lungs, kidneys and intestine postburn. There was no detectable TNF-alpha in the plasma of anti-TNF-alpha mAb treated animals. Treatment with anti-TNF-alpha mAb also resulted in significantly lower concentrations of LBP mRNA in local tissues. Additionally, several organ function parameter levels in plasma significantly decreased in treatment group. These results demonstrated that an increase of plasma TNF-alpha levels caused by burns might be associated with a marked elevation of tissue LBP mRNA expression, which could contribute to the development of multiple organ damage.

Acute-Phase Proteins↗
PubMed2004

Genetic regulation of endotoxin-induced airway disease.

To identify novel genes regulating the biologic response to lipopolysaccharide (LPS), we used a combination of quantitative trait locus (QTL) analysis and microarray-based gene expression studies of C57BL/6J x DBA/2J(BXD) F2 and recombinant inbred (RI) mice. A QTL affecting pulmonary TNF-alpha production was identified on chromosome 2, and a region affecting both polymorphonuclear leukocyte recruitment and TNF-alpha levels was identified on chromosome 11. Microarray analyses of unchallenged and LPS-challenged BXD RI strains identified approximately 500 genes whose expression was significantly changed by inhalation of LPS. Of these genes, 28 reside within the chromosomal regions identified by the QTL analyses, implicating these genes as high priority candidates for functional studies. Additional high priority candidate genes were identified based on their differential expression in mice having high and low responses to LPS. Functional studies of these genes are expected to reveal important molecular mechanisms regulating the magnitude of biologic responses to LPS.

Animals↗
PubMed2004

The role of bone morphogenetic proteins BMP-2 and BMP-4 and their related postreceptor signaling system (Smads) in distraction osteogenesis of the mandible.

Distraction osteogenesis has become a widely used clinical approach in the treatment of craniofacial and orthopedic disorders. The exact biological mechanism of bone formation remains illusive, however. The aim of this study was to evaluate the role of bone morphogenetic protein-2, bone morphogenetic protein-4, and transforming growth factor-beta superfamily-related postreceptor signaling glycoproteins Smads 1 through 5 in distraction osteogenesis. Twelve sheep randomly divided into two groups were distracted to 24 mm at 1 or 4 mm/d using a submandibular osteotomy and an external distractor. After a 5-week fixation period, the mandibles were harvested. Employing immunohistochemical techniques, the sections were investigated for the previous antigens. Osteoblasts and periosteal lining cells were strongly positive. The matrix did not stain for the antigens investigated. Osteocytes demonstrated weak staining for the antigens. No significant difference between the groups was noted. In fracture healing, bone morphogenetic proteins 2 and 4 have been localized to the cambial layer of the periosteum, where healing occurs by intramembranous ossification. Their diffuse staining of the osteoblasts in the distracted region supports a similar role in distraction osteogenesis, where bone formation is predominantly through intramembranous ossification. Furthermore, bone morphogenetic proteins 2 and 4 have been demonstrated to promote mesenchymal cell conversion to osteoblasts. This is similar to the process observed in distraction osteogenesis. The presence of related Smads confirms postreceptor activity of these bone morphogenetic proteins in the process of distraction osteogenesis. This study supports induction of bone morphogenetic proteins 2 and 4, their related postreceptor signaling system (Smads), and intramembranous bone formation associated with mechanical strain in distraction osteogenesis.

Animals↗