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Biomedical subjects

Yu Wang

Publications and source records attributed to Yu Wang.

At least 109 records · Page 6Linked to original sources
PubMed2006

Local disruption of the celiac ganglion inhibits substance P release and ameliorates caerulein-induced pancreatitis in rats.

Primary sensory neurons of the C and Adelta subtypes express the vanilloid capsaicin receptor TRPV1 and contain proinflammatory peptides such as substance P (SP) that mediate neurogenic inflammation. Pancreatic injury stimulates these neurons causing the release of SP in the pancreas resulting in pancreatic edema and neutrophil infiltration that contributes to pancreatitis. Axons of primary sensory neurons innervating the pancreas course through the celiac ganglion. We hypothesized that disruption of the celiac ganglion by surgical excision or inhibition of C and Adelta fibers through blockade of TRPV1 would reduce the severity of experimental pancreatitis by inhibiting neurogenic inflammation. Resiniferatoxin (RTX) is a specific TRPV1 agonist that, in high doses, selectively destroys C and Adelta fibers. Sprague-Dawley rats underwent surgical ganglionectomy or application of 10 microg RTX (vs. vehicle alone) to the celiac ganglion. One week later, pancreatitis was induced by six hourly intraperitoneal injections of caerulein (50 microg/kg). The severity of pancreatitis was assessed by serum amylase, pancreatic edema, and pancreatic myeloperoxidase (MPO) activity. SP receptor (neurokinin-1 receptor, NK-1R) internalization in acinar cells, used as an index of endogenous SP release, was assessed by immunocytochemical quantification of NK-1R endocytosis. Caerulein administration caused significant increases in pancreatic edema, serum amylase, MPO activity, and NK-1R internalization. RTX treatment and ganglionectomy significantly reduced pancreatic edema by 46% (P < 0.001) and NK-1R internalization by 80% and 51% (P < 0.001 and P < 0.05, respectively). RTX administration also significantly reduced MPO activity by 47% (P < 0.05). Neither treatment affected serum amylase, consistent with a direct effect of caerulein. These results demonstrate that disruption of or local application of RTX to the celiac ganglion inhibits SP release in the pancreas and reduces the severity of acute secretagogue-induced pancreatitis. It is possible that selectively disrupting TRPV1-bearing neurons could be used to reduce pancreatitis severity.

Acute Disease↗
PubMed2006

Prostate cancer treatment is enhanced by genistein in vitro and in vivo in a syngeneic orthotopic tumor model.

Pretreatment with genistein, a bioactive component of soy isoflavones, potentiated cell killing induced by radiation in human PC-3 prostate cancer cells in vitro. Using an orthotopic xenograft in nude mice, we demonstrated that genistein combined with prostate tumor irradiation caused greater inhibition of primary tumor growth and increased control of spontaneous metastasis to para-aortic lymph nodes, increasing mouse survival. Paradoxically, treatment with genistein alone increased metastasis to lymph nodes. This observation is of concern in relation to soy-based clinical trials for cancer patients. To address whether this observation is because nude mice have an impaired immune system, these studies were repeated in orthotopic RM-9 prostate tumors in syngeneic C57BL/6 mice. The combination of genistein with radiation in this model also caused a greater inhibition of primary tumor growth and spontaneous metastasis to regional para-aortic lymph nodes, whereas treatment with genistein alone showed a trend to increased lymph node metastasis. Data from the syngeneic and xenograft models are comparable and indicate that the combination of genistein with radiotherapy is more effective and safer for prostate cancer treatment than genistein alone, which promotes metastatic spread to regional lymph nodes.

Animals↗
PubMed2006

The cardioprotective peptide, urocortin, activates cardiac KATP channels in adult rat.

Urocortin (UCN), an endogenous cardioprotective peptide, has been reported to activate several ion channels but its effects on the cardiac KATP channels are unknown. In this paper, we showed that adult rat cardiac myocytes had small KATP currents that could be increased 20-fold by pinacidil. UCN also concentration-dependently activated the KATP current and this effect was influenced by ATP and PKA inhibitor peptide, Rp-cAMPS.

Adenosine Triphosphate↗
PubMed2006

Dynamic CT Evaluation of Tumor Vascularity in Renal Cell Carcinoma.

OBJECTIVE: The purpose of our study was to evaluate the correlation between the enhancement parameters of dynamic CT; the carcinoma tissue microvessel density (MVD, a hotspot method to provide a histologic assessment of tumor vascularity); and tumor nuclear grade in renal cell carcinomas. SUBJECTS AND METHODS: Twenty-four patients with histologically diagnosed renal cell carcinoma underwent dynamic enhanced CT. Enhancement parameters, slope of the time-density curve, the density difference before and after tissue enhancement (deltaH), tissue blood ratio (TBR), and area under the time-density curve (AR), were calculated for all lesions. Pathology slides corresponding to the CT plane were stained using mouse antihuman CD34 monoclonal antibody and H and E. Fuhrman nuclear grade was used. Vascular hot spots of microvessels were recorded. Spearman's rank correlation was performed to determine the strength of the relationship between enhancement parameters, MVD determinations, and tumor nuclear grade. RESULTS: MVD with CD34 staining revealed uneven distribution of positively stained vascular endothelial cells in renal cell carcinoma lesions. Heterogeneous distribution of contrast enhancement was seen among and within individual tumors. The tumors appeared as uneven patterns on time-density curves of renal cell carcinoma lesions. Enhancement parameters of H (median, 21.0 H; range, 2.2-105.8 H), TBR (median, 39%; range, 10.7-154.7%), AR (median, 1.58 H x sec; range, 0.23-3.67 H x sec), and slope (median, 2.76; range, 0.53-6.76) varied greatly. Renal cell carcinoma tissue MVD significantly correlated with all enhancement parameters of dynamic CT. The correlation coefficients (r) were 0.62, 0.54, 0.55, and 0.44, respectively, for delta H, slope, TBR, and AR (p < 0.0 5). All enhancement parameters did not significantly correlate with tumor nuclear grade. They were not predictive of nuclear grade. CONCLUSION: Enhancement parameters of dynamic CT may be suited to evaluate tumor vascularity in vivo. Dynamic enhanced CT images may reflect the heterogeneity of tumor angiogenesis on the basis of the correlation between enhancement parameters and MVD of renal cell carcinoma.

Adolescent↗
PubMed2006

Human Streptococcus suis outbreak, Sichuan, China.

From mid-July to the end of August 2005, a total of 215 cases of human Streptococcus suis infections, 66 of which were laboratory confirmed, were reported in Sichuan, China. All infections occurred in backyard farmers who were directly exposed to infection during the slaughtering process of pigs that had died of unknown causes or been killed for food because they were ill. Sixty-one (28%) of the farmers had streptococcal toxic shock syndrome; 38 (62%) of them died. The other illnesses reported were sepsis (24%) and meningitis (48%) or both. All isolates tested positive for genes for tuf, species-specific 16S rRNA, cps2J, mrp, ef, and sly. A single strain of S. suis caused the outbreak, as shown by the identification of a single ribotype. The high death ratio was of concern; prohibiting backyard slaughtering ended the outbreak.

Adult↗
PubMed2006

Streptococcus suis sequence type 7 outbreak, Sichuan, China.

An outbreak of Streptococcus suis serotype 2 emerged in the summer of 2005 in Sichuan Province, and sporadic infections occurred in 4 additional provinces of China. In total, 99 S. suis strains were isolated and analyzed in this study: 88 isolates from human patients and 11 from diseased pigs. We defined 98 of 99 isolates as pulse type I by using pulsed-field gel electrophoresis analysis of SmaI-digested chromosomal DNA. Furthermore, multilocus sequence typing classified 97 of 98 members of the pulse type I in the same sequence type (ST), ST-7. Isolates of ST-7 were more toxic to peripheral blood mononuclear cells than ST-1 strains. S. suis ST-7, the causative agent, was a single-locus variant of ST-1 with increased virulence. These findings strongly suggest that ST-7 is an emerging, highly virulent S. suis clone that caused the largest S. suis outbreak ever described.

Animals↗
PubMed2006

[Cloning, sequence analysis and expression of alanine racemase gene in Pseudomonas putida].

Two distinct alanine racemase genes from Pseudomonas putida 200 were cloned and sequenced. DadX encodes a peptide of 357 amino acids with a calculated molecular weight of 38.82kDa. The putative product of alr gene is a peptide of 409 amino acids with molecular weight of 44.182kDa. A homology comparison revealed identities of 96.64%, 71.99%, 44.88% and 47.37% of the DadX alanine racemase to those from P. putida KT2440, Pseudomonas aeruginosa, Salmonella typhimurium and Escherichia coli, respectively. The amino acids sequence deduced from alr gene showed the homologies of 94.38%, 22.89%, 25.72% and 26.44% to those from the microorganisms above, respectively. Two motifs believed essential to the enzyme activity are found both in DadX and Alr, such as pyridoxal-5'-phosphate binding site. Both dadX and alr were expressed in E. coli TG1. Neither alanine racemase activity or serine racemase activity was detected in the host strain. Only alanine racemase activity was found in E. coli TG1/pCTD. But both E. coli TG1/pCTA and TG1/pCBA exhibit activity toward L-alanine and L-serine. Transcription of alr gene in E. coli is independent from extraneous promoter, a result confirmed by the significant enzyme activity observed in the E. coli TG1/pCBA, which indicates the presence of a possible promoter upstream the structure gene.

Alanine Racemase↗
PubMed2006

[Cloning, sequence analysis and expression of N-acetylglutamate kinase gene in Corynebacterium crenatum].

N-Acetylglutamate kinase (EC 2.7.2.8;NAGK) genes from wild-type Corynebacterium crenatum AS 1.542 and a L-arginine-producing mutant C. crenatum 971.1 were cloned and sequenced. Analysis of argB sequences revealed that only one ORF existed, which used ATG as the initiation codon and coded a peptide of 317 amino acids with a calculated molecular weight of 33.6kDa. Only one nucleotide difference was found in the structure gene and the difference did not cause a change of amino acid by comparison of the gene sequences between the wild type C. crenatum AS 1.542 and the mutant 971.1. The ORF sequence of argB from C. crenatum AS 1.542 showed homologies of 99.89%, 76.62%, 37.94% to those from Corynebacterium glutamicum ATCC 13032, Corynebacterium efficient YS-314 and Escherichia coli k12. And the amino acid sequence deduced from ORF displayed homologies of 100%, 78.55%, 25.25% to those from microorganisms above, respectively. An internal promoter was found in the upstream of the argB gene from C. crenatum. The argB gene from C. crenatum AS 1.542 was expressed both in C. crenatum AS 1.542 and 971.1. The NAGK activity of transformed C. crenatum AS 1.542 was greatly increased by the induction of IPTG. The NAGK activity of transformed C. crenatum 971.1 was almost twice as much as that of C. crenatum 971.1 under the same induction. The amplification of the NAGK activity yielded 25% increase of L-arginine production in C. crenatum 971.1.

Amino Acid Sequence↗
PubMed2006

[Status and influencing factors of mercury exposure in neonates and their mothers in Zhoushan].

OBJECTIVE: To investigate the status of mercury exposure of neonates and their mothers in Zhoushan City, and analyze the related influencing factors. METHODS: From Aug to Sep, 2004, 408 neonate-mother pairs were cluster sampled at the Third People's Hospital in Dinghai region, Zhoushan City, and a further investigation for the neurobehavioral development of these children was followed up in a year. The contains of mercury of 14 kinds of fish, 5 pieces of each kind bought in markets of Dinghai region were detected. RESULTS: The geometric mean of cord-blood Hg was 27.81 nmol/L (5.58 microg/L), while that of hair Hg of mothers was 1246.56 microg/kg. 69.9% of pregnant women had surpassed the RfD (reference dose, 0.1 microg/kg/day) for Hg intake. There was a strong correlation between hair and cord blood Hg levels (r = 0.821). The factors influencing cord-blood Hg levels were fish dinners, dwelling time, and fathers smoking or not, while those of hair Hg were fish dinners and dwelling time. The correlation between fish dinners and the cord blood Hg as well as hair Hg were of significance (r = 0.539, 0.481 respectively), the Hg levels were higher in more fish dinners (H = 119.805, 94.384 respectively). The mean fish Hg level at Dinghai region was low (< 0.1 mg/kg), and no samples were higher than 0.5 mg/L. Two samples of cutlassfish and dried eel contained higher Hg than the others, belonging to a middle level (0.1-0.5 mg/kg). CONCLUSIONS: Hg levels in neonates and pregnant women were generally below those considered hazardous, but the safety margin was narrow for some women and supporting efforts should be made to reduce mercury exposure. The main resource of Hg was from eating fish, and it is necessary to investigate the Hg levels in large samples, as to developing the fish advisories for susceptible people.

China↗
PubMed2006

[A clinical analysis of 32 cases of POEMS syndrome].

OBJECTIVE: To compare the clinical features of POEMS (polyneuropathy, organomegaly, endocrinopathy, M protein and skin changes) syndrome patients from Peking Union Medical College Hospital (PUMCH) with those of patients in previous reports. METHODS: Thirty-two patients with POEMS syndrome were identified in PUMCH over the last two decades. The clinical features of these patients were compared with those in other large series from Japan, China, and the United States. RESULTS: The average age at presentation was 45.8 years; 22 were men. All 32 patients had polyneuropathy and decreased knee-jerk reflex. Organomegaly was present in 31 patients. Nine patients underwent lymph node biopsy and 5 of them were proven to have Castleman's disease. Twenty-six patients had at least one endocrine abnormality at time of presentation, not including more commonly prevalent diseases like diabetes mellitus or hypothyroidism. Seventy-two percent (18/25) of the patients had a detectable monoclonal protein with serum immunofixation, but only 16.7% (4/24) had positive results with serum protein electrophoresis. Skin changes were documented in 30 patients. In comparison with other series, we found a higher prevalence of organomegaly and papilloedema. The rates of M protein level, however, were similar. CONCLUSIONS: Most features of our series are similar to those from previous foreign series. The prevalence of M protein in our study was similar to that in previous foreign series, but was not as low as reported in previous Chinese studies. Immunofixation and immunohistochemical staining of bone marrow biopsies are probably more sensitive in detecting M protein as compared with serum protein electrophoresis.

Adult↗
PubMed2006

[Analyzing differentially expressed genes in the brain of rat exposed to mercury chloride using cDNA microarray].

This study is to determine differentially expressed genes in the brain of rat exposed to mercury chloride and investigate the molecular mechanism of mercury neurotoxicity using cDNA microarray. The experimental group of rats were treated with 0.5 mg/kg weight of mercury chloride via hypodermic injection. The differentially expressed genes in rat brains after I h of injection were scanned by the cDNA microarray. The gene expression profiles show that there are 742 genes, in which 562 are upregulated and 180 are downregulated. Further analysis by bioinformatic technique disclosed that the differentially expressed genes were involved in many biological processes, which included immuno-response and detoxifcation, transfer and expression of genetic information, cell signalling, neurotransduction, cell proliferation and cell differentiation, apoptosis, etc. The result of analysis indicated these genes might be related to the neurotoxicity of mercury. The investigation of differentially expressed genes using cDNA microarray provides a new approach to further disclose the neurotoxic mechanism of mercury.

Animals↗
PubMed2006

[Comparison of reliability of bispectral index and sedation-agitation scale in assessing the depth of sedation in patients treated with mechanical ventilation].

OBJECTIVE: To compare the reliability of bispectral index (BIS) with sedation agitation scale (SAS) in assessing the depth of sedation in ill patients on mechanical ventilation in intensive care unit (ICU). METHODS: Fifteen patients, aged 18-65 years old, who were receiving mechanical ventilation in ICU for longer than 72 hours and without brain dysfunction, were enrolled in this study. Sedatives and analgesics were suspended at 7:00 am. When patients fully woke up, propofol was infused till BIS score reaching 45-60. This was maintained for 10 minutes, then propofol dosage was decreased 10 microg . kg(-1) . min(-1) for every 10 minutes till all the drug was stopped. BIS was consecutively monitored and SAS was assessed in each interval. RESULTS: BIS score was markedly correlated with SAS (r=-0.6494, P<0.01). Although a significant correlation was still shown (r=-0.4566, P<0.01), there was wide variability in BIS scores when SAS reached 2-4. With decreasing of the propofol dosage, BIS score gradually increased. There was a satisfactory negative correlation between BIS scores and propofol dosage (r=-0.8076, P<0.01). SAS increased also following the decrease in propofol dosage, and a significant negative correlation was shown between SAS and the dosage of propofol (r=-0.6551, P<0.01). CONCLUSION: SAS is well correlated with BIS in assessing the depth of sedation in patients treated with mechanical ventilation in ICU. BIS is an objective, efficient tool for monitoring the depth of sedation in ICU critical patients who are receiving mechanical ventilation, and it is more reliable than SAS, especially when sedated levels reaching SAS 2-4.

Adult↗
PubMed2006

[An outbreak of human Streptococcus suis serotype 2 infections presenting with toxic shock syndrome in Sichuan, China].

OBJECTIVE: In mid-July 2005, five patients presented with septic shock to a hospital in Ziyang city in Sichuan, China, to identify the etiology of the unknown reason disease, an epidemiological, clinical, and laboratory study were conducted. METHODS: An enhanced surveillance program were established in Sichuan, the following activities were introduced: active case finding in Sichuan of (a) laboratory diagnosed Streptococcus suis infection and (b) clinically diagnosed probable cases with exposure history; supplemented by (c) monitoring reports on meningococcal meningitis. Streptococcus suis serotype 2 infection was confirmed by culture and biochemical reactions, followed by sequencing for specific genes for serotype and virulence factors. RESULTS: From June 10 to August 21, 2005, 68 laboratory confirmed cases of human Streptococcus suis infections were reported. All were villagers who gave a history of direct exposure to deceased or sick pigs in their backyards where slaughtering was performed. Twenty six (38%) presented with toxic shock syndrome of which 15 (58%) died. Other presentations were septicaemia or meningitis. All isolates were tested positive for genes for tuf, species-specific 16S rRNA, cps2J, mrp, ef and sly. There were 136 clinically diagnosed probable cases with similar exposure history but incomplete laboratory investigations. CONCLUSION: An outbreak of human Streptococcus suis serotype 2 infections occurred in villagers after direct exposure to deceased or sick pigs in Sichuan. Prohibition of slaughtering in backyards brought the outbreak to a halt. A virulent strain of the bacteria is speculated to be in circulation, and is responsible for the unusual presentation of toxic shock syndrome with high case fatality.

Animals↗
PubMed2006

[Laboratory diagnoses of the first confirmed human case of avian influenza A (H5N1) in the mainland of China].

BACKGROUND: To determine the etiologic agent of an atypical pneumonia human case admitted to Xiangtan City hospital, Hunan Province in Oct. 2005. METHODS: The patient's respiratory tract samples and serum were collected. Throat swabs were tested by microneutralization and hemagglutination-inhibition assays. RESULTS: The results of nucleic acid detection of all respiratory samples were negative and virus isolation was also negative. The H5-specific antibodies of convalescence showed a 4-fold greater rise than acute phase. CONCLUSION: The atypical pneumonias case was confirmed as the first human case of avian influenza A (H5N1) infection in the mainland of China.

Animals↗
PubMed2006

[Study on risk factors for early postoperative infection after orthotopic liver transplantation in adults].

OBJECTIVE: To analyze risk factors related to infection during early postoperative period after orthotopic liver transplantation in adults. METHODS: Retrospective study of 400 cases of orthotopic liver transplantation in adults performed between 2003 and 2004. Pre-, intra- and postoperative variables of recipients were analyzed in two groups according to whether or not infection developed. RESULTS: Infection developed in 121 patients (30.3%). Bacterial infections were most common, accounting for 62.0% (75/121 cases), followed by fungal infection with the percentage of 20.6% (25/121 cases), and virus infection accounting for 12.4% (15/121 cases). The common infection sites were lung (63 cases, 52.1%), gallbladder (23 cases, 19.0%), peritoneal cavity (22 cases, 18.2%), and venous catheter (13 cases, 10.7%). Significant risk factors for infection as shown by the multivariate analysis were acute renal failure, graft dysfunction, acute lung injury, postoperative bleeding, pulmonary edema, history of diabetes mellitus or new onset diabetes mellitus, Child-Pugh stage>10, age>60. CONCLUSION: Early postoperative infection after orthotopic liver transplantation in adults is a common and serious complication that continues to be difficult to control. Certain risk factors can be improved with careful management such as acute kidney failure and graft dysfunction. Appropriate anti-infection remedy is very important to prevent drug resistance. However, immunosuppression agents acts as a real predisposing factor of infection with regard to both its development and its clinical manifestation.

Adolescent↗
PubMed2006

[The first confirmed human case of avian influenza A (H5N1) in mainland, China].

OBJECTIVE: To ascertain the causation of a family cluster involving two undefined pneumonia cases, a 12-year-old girl and her brother, reported October, 2005 in Xiangtan county, Hunan province. METHODS: Information on epidemiology and clinical manifestation of the cases was collected from interviewing the keyman and referring to related medical records. The environment exposure of the cases to their households and the timeline of the illness were reproduced, using this information. Medical check-up was undergone among the close contacts of the cases and on sick/dead poultry. Throat swab of the cases were collected and tested by both RT-PCR and real-time PCR to detect viral nucleic acids of A/H5N1, and were then inoculated into special pathogen free (SPF) embryonated hens' eggs. Serum of the cases including acute and convalescent phases were also collected and tested by microneutralization and haemagglutination-inhibition (HI) assays to detect H5-specific antibodies. RESULTS: Both the girl and her brother developed fever 2 and 4 days after sudden deaths of chickens being raised in the same house. Both of them had developed pneumonia and the girl died from acute respiratory distress syndrome (ARDS) complicated with multi-organ failure. The boy survived and subsequently discharged from hospital. An eighth-day serum from the girl tested H5 antibody negative, while 4-fold and greater increased in antibody titers were detected in serum from the boy using microneutralization and HI assays in sequential acute and convalescent sera. Of 192 cases, only one doctor who cared for the girl during hospitalization had upper respiratory symptoms but tested negative for H5N1 by microneutralization assay. CONCLUSION: The boy was the first confirmed human case of avian influenza A (H5N1) in the mainland of China and his sister was diagnosed clinically. The most probable explanation of these two cases was that the transmission of H5N1 virus from infected poultry within the same household environment. No evidence of human-to-human transmission was noted in the family cluster.

Animals↗
PubMed2006

[Study on a fatal pregnant woman died from by avian influenza (H5N1)].

OBJECTIVE: To ascertain the causation of a pregnant woman with undefined pneumonia reported from the People's Hospital of Tongling city in Anhui province on November 2005. METHODS: Epidemiological and clinical information of the case was collected from the keypersons close to the case and referring to the medical record. A medical observation was carried out on the close contacts of the case and sick or dead poultry. Tracheal aspirates being collected were tested by both RT-PCR and real-time PCR to detect viral nucleic acids of A/H5N1, and were inoculated into special pathogen free (SPF) embryonated hens' eggs. RESULTS: The pregnant woman was found to have been contacted with the sick/dead poultry directly on the 4th day before onset of illness. All the 122 close contacts were healthy after a 10-day medical observation. The major clinical features of the case were viral pneumonia with rapidly developed leukopenia and lymphopenia. The progress to acute respiratory distress syndrome and multiple organ dysfunction syndromes was found at clinical presentation. HA and NA gene of A/H5N1 virus were positive. The 8 gene fragments of A/Anhui/1/2005 (H5N1) isolated from the tracheal aspirates had not carried genes from a human virus through reassortment, and the receptor-binding site of the hemagglutinin was polybasic cleavage site. CONCLUSION: This was the first documented case of H5N1 infection in pregnant woman. The immunotolerant state of pregnancy might have predisposed to the fatal outcome of the patient.

Adult↗