Association of K121Q Polymorphism in Ectonucleotide Pyrophosphatase/Phosphodiesterase 1 with Clinical Characteristics of Metabolic Syndrom

PURPOSE

This study aimed to investigate the relationships between K121Q polymorphism of ectonucleotide pyrophosphatase/phosphodiesterase 1 (ENPP1) and clinical characteristics of metabolic syndrome (MS) in northern Han Chinese.

MATERIALS AND METHODS

A total of 209 MS patients and 248 healthy controls of Han ethnic group in northern China were enrolled in this study. Various clinical parameters of these participants were firstly collected and compared, including age, sex, body mass index (BMI), waist circumference (WC), systolic and diastolic blood pressures (SBP/DBP), fasting plasma glucose (FPG), fasting insulin (FINS), homeostasis model assessment of insulin resistance index (HOMA-IR), total cholesterol (TC), triglycerides (TG), high-density and low-density lipoprotein cholesterol (LDL-C/HDL-C). Then K121Q polymorphism of ENPP1 was determined by PCR and restriction enzyme digestion, and its relations with related clinical parameters were finally analyzed.

RESULTS

When compared with healthy controls, the age, BMI, WC, SBP, DBP, FPG, FINS, HOMA-IR, TC, TG and LDL-C were all significantly increased in MS patients (P<0.001). The allele frequencies of K and Q alleles in ENPP1 were 90.19% and 9.81% in MS patients, and 91.73% and 8.27% in healthy controls, respectively. Besides, only BMI and WC were significantly increased in MS patients carrying Q alleles (P<0.001), while no significant relations were found between K121Q polymorphism and other clinical parameters in either MS patients or healthy controls.

CONCLUSION

The K121Q polymorphism of ENPP1 showed no direct correlation with MS, although it showed some correlation with BMI and WC in MS patients.

Analysis of uridine diphosphate glucuronosyl transferase 1A1 gene mutations in neonates with unconjugated hyperbilirubinemia

This study was carried out to analyze uridine diphosphate (UDP)-glucuronosyltransferase 1A1 (UGT1A1) gene mutations in neonates with unconjugated hyperbilirubinemia, from two different ethnic groups. Polymerase chain reaction and gene sequencing were used to analyze the differences in genotypes and allele frequencies of different gene mutations among the ethnic groups; this was followed by checking their correlation with the serum bilirubin level and the occurrence of unconjugated hyperbilirubinemia in neonates. Our results reveal that the UGT1A1 mutant genotype, 211G>A, is distributed differently in the case vs control groups, as well as in the Zhuang vs Han ethnic groups. Moreover, this difference is statistically significant (P < 0.05); the total serum bilirubin (TSB) and unconjugated bilirubin (UCB) levels in patients carrying the single homozygous mutation, 211G>A, were markedly higher than that in patients without the mutation (P < 0.05). Furthermore, the TSB and UCB levels were significantly different between patients carrying single or compound 211G>A heterozygous mutation, (TA)6/7, and 1941C>G/2042C>G heterozygous mutation, and patients without mutation (P > 0.05). Our findings suggest that the 211G>A mutation in the first exon may be a risk factor for unconjugated hyperbilirubinemia in Zhuang and Han neonates. The serum bilirubin levels seem to be affected by the homozygosity or heterozygosity of the UGT1A1 gene mutation; 211G>A homozygous mutation is an important factor that causes a rise in bilirubin in neonates with unconjugated hyperbilirubinemia.

Dietary Influence on Calcitropic Hormones and Adiposity in Caucasian and African American Postmenopausal Women Assessed by Structural Equation Modeling (SEM)

OBJECTIVES

To examine differences in hydroxycholecalciferol (25(OH)D) and parathyroid hormone (PTH) concentrations between Caucasian and African American (AA) postmenopausal women, as well as the effects of dietary calcium, protein and vitamin D intakes on 25(OH)D, PTH, and body adiposity using structural equation modeling (SEM).

DESIGN

Population-based prospective cohort study.

SETTING

Academic research using the baseline data from two longitudinal studies. Participants Included n=113 Caucasian and n=40 African American, postmenopausal women who completed the baseline data collection and met inclusion criteria (dietary calcium intake <900 mg/day and being generally healthy) between 2006 and 2010.

MAIN OUTCOME

Dietary intake of calcium and vitamin D, assessed by dietary records, were examined in relation to calcitropic hormones concentrations and adiposity markers. Independent t-tests, confirmatory factor analysis, SEM and multi-group analyses were conducted to examine the aforementioned relationships as well as group differences among hormones, dietary intake, anthropometrics, age and other factors.

RESULTS

Dietary calcium and protein intakes were significantly lower in AA women. Years since menopause were significantly higher in AA compared to Caucasian women. PTH and 25(OH)D levels were significantly lower in AA compared to Caucasian women. Dietary calcium and protein intakes did not influence body adiposity in either group of women. Dietary vitamin D had minimal indirect (via 25(OH)D levels) influence on adiposity.

CONCLUSION

The study confirmed the positive relationship of 25(OH)D with adiposity markers and both AA and Caucasian women. The study provides a unique example of the use of SEM in nutrition research within a clinical context. This model should be further tested in other populations.

A role of 1,25(OH)2D3 supplementation in rats with nonalcoholic steatohepatitis induced by choline-deficient diet

BACKGROUND AND AIMS

It has been reported that 1,25(OH)2D3 (1,25-VD3) ameliorates the progression of nonalcoholic steatohepatitis (NASH). However, it is unclear whether 1,25-VD3 plays a role in NASH induced by a choline-deficient (CD) diet. In this study, we investigated the roles of 1,25-VD3 in the development and progression of NASH in rats induced by a CD diet.

METHODS AND RESULTS

Wistar rats with NASH induced by a CD diet were subjected to intraperitoneal injections of 1, 5, or 10 μg/kg of 1,25-VD3 twice weekly for 12 weeks. The administration of 1,25-VD3 decreased free fatty acids (FFAs), triglycerides (TGs), thiobarbituric acid-reactive substances (TBARS), the number of apoptotic cells, and the expression of tissue inhibitor of metalloproteinase-1 (TIMP-1) in the liver, and it improved liver histology, but it did not change the total antioxidant capacity (TAOC) in the liver. Interestingly, the level of CK18-M30 was decreased in the liver of model animals. Treatment with 1,25-VD3 may restrain the downregulation of CK18-M30 in the liver and its release into the bloodstream, thus decreasing the level of serum CK18-M30. 1,25-VD3 supplementation elevated the serum level of 25(OH)D3 and the expression of VDR in the liver. The dose-effect relationship of 1,25-VD3 indicated that 1,25-VD3 slows down the development and progression of NASH induced by a CD diet, but higher doses of 1,25-VD3 may lead to adverse effects.

CONCLUSION

The results suggest the presence of both antagonistic and adverse dose-dependent effects of the long-term supplementation of 1,25-VD3 on NASH induced by a CD diet.

Association of TUSC3 gene polymorphisms with non-syndromic mental retardation based on nuclear families in the Qinba mountain area of China

TUSC3 interacts with the protein phosphatase 1 and magnesium ion transport system, which plays an important role in learning and memory. Abnormal conditions of learning and memory are common clinical characteristics of mental retardation (MR). However, the association of TUSC3 genetic polymorphisms with MR remains unknown. A total of 456 DNA samples including 174 nuclear families containing MR were collected in the Qinba mountain area of China. The genotypes of eight tag single nucleotide polymorphisms of TUSC3 were evaluated with traditional genetic methods. Family-based association tests, transmission disequilibrium tests (TDTs), and haplotype relative risk (HRR) analyses were performed to investigate the association between genetic variants of the TUSC3 gene and MR. The genetic polymorphisms rs10093881, rs6530893, and rs6994908 were associated with MR (all P values <0.05) based upon the results of single-site TDT and HRR analyses. The haplotype block consisting of rs6530893 and rs6994908, harboring the sixth exon of TUSC3, was also associated with MR (all P values <0.05). This study demonstrated an association between genetic polymorphisms of the TUSC3 gene and MR in the Qinba mountain area, the sixth exon of which might contribute to the risk of MR. However, further studies are needed on the causal mechanisms in this association.

[Relationship between serum histamine levels and ST-segment resolution in patients with acute myocardial infarction treated with primary percutaneous coronary intervention]

OBJECTIVE

To investigate the dynamic changes in serum histamine levels and their association with ST-segment resolution in patients with acute ST-segment elevation myocardial infarction (STEMI) treated with primary percutaneous coronary intervention (PCI).

METHODS

A total of 84 consecutive STEMI patients who received primary PCI were enrolled in this study. The dynamic changes in serum histamine levels were observed from before PCI to 1 week after PCI. Factors associated with ST-segment resolution were identified by multivariate regression analysis.

RESULTS

The serum histamine levels of STEMI patients decreased during the first week after PCI. Multivariate regression analysis showed that the factors associated with ST-segment resolution 2 h after PCI were: the histamine level 2 h after PCI (r=-0.361, P=0.001), pain to balloon time, infarct related artery, and thrombolysis in myocardial infarction (TIMI) flow grade after PCI.

CONCLUSION

The higher histamine level 2 h after PCI was independently associated with poor myocardial reperfusion in STEMI patients.

Effect of codon optimization on expression levels of human cystatin C in Pichia pastoris

Human cystatin C (CysC) is a cysteine proteinase inhibitor with many potential applications. To facilitate further studies of the functions and applications of CysC, we improved the heterologous expression of CysC using a basic codon optimization method. In this study, we cloned the high-GC content wild-type sequence of the CysC gene and also designed a slightly AT-biased sequence, with codons optimized for expression in the Pichia pastoris GS115 strain. Our results showed that the optimized coding sequence of human CysC increased the expression and secretion of the CysC protein by approximately 3- to 5-fold (90-96 mg CysC/L) in yeast, compared with the expression levels of the native CysC gene (17.9-18.4 mg CysC/L). We designed, constructed, and applied an optimized version of the CysC gene for the Pichia expression system. Our results demonstrate that the optimized coding sequence provides a higher yield of secreted CysC than that produced using the wild-type gene. Our data also serve as a practical example demonstrating a rational design strategy for the heterologous expression of secreted proteins.

Surgicel application in intracranial hemorrhage surgery contributed to giant-cell granuloma in a patient with hypertension: case report and review of the literature

BACKGROUND

Surgicel is an oxidized cellulose preparation that is widely applied in neurosurgery due to its hemostatic effect and good tissue compatibility. Tumor-like lesions induced by Surgicel application in cerebral surgery have been rarely reported, especially for intracranial hemorrhage debridement surgery in patients with hypertension.

CASE PRESENTATION

This case report describes a rare case in which Surgicel application led to a foreign body reaction, contributing to the development of an intracranial giant-cell granuloma. A 49-year-old female hypertensive patient was diagnosed with intracranial hemorrhage. She was treated with debridement surgery that employed Surgicel application. Although a satisfactory hemostatic effect was achieved, the patient was diagnosed with epilepsy 6 months later. Subsequent magnetic resonance imaging revealed an intracranial space-occupying lesion. After undergoing en bloc resection of the lesion, the patient was diagnosed with a Surgicel-related intracranial giant-cell granuloma by histopathology.

CONCLUSIONS

Application of Surgicel during intracranial hemorrhage debridement surgery may be associated with a risk of granuloma development due to formation of a tumor-like space-occupying lesion in the surgery bed. Even a low risk of tumor development implies a need for caution when applying Surgicel, especially when solely used to achieve a hemostatic effect.

Association between metabolic syndrome and white matter lesions in middle-aged and elderly patients

BACKGROUND AND PURPOSE

Metabolic syndrome (MetS) has been reported to be associated with silent lacunar infarction, which is highly related to white matter lesions (WMLs). However, little is known about the relationship between MetS and the prevalence of WMLs. The association between MetS, its components and WMLs in middle-aged and elderly patients was investigated.

METHODS

Consecutive patients aged 50 years and older were prospectively enrolled in this study. All participants underwent magnetic resonance imaging scans to assess the presence and severity of WMLs. The MetS was defined according to the updated National Cholesterol Education Program's Adult Treatment Panel III criteria. Multivariate logistic regression analyses were performed to examine the relationship between MetS, its components and WMLs.

RESULTS

A total of 852 patients were enrolled in the study. MetS was present in 38.4%. MetS was associated with an increased risk of periventricular WMLs (PVWMLs) and deep WMLs (DWMLs) after multivariable adjustment (odds ratio 3.21, 95% confidence interval 2.26-4.55 for PVWMLs; odds ratio 2.93, 95% confidence interval 2.09-4.09 for DWMLs). Amongst MetS components, elevated blood pressure, elevated fasting blood glucose and low high density lipoprotein cholesterol were associated with PVWMLs, whilst elevated blood pressure and low high density lipoprotein cholesterol were related to DWMLs.

CONCLUSIONS

Our findings demonstrate that MetS is associated with the prevalence of PVWMLs and DWMLs independent of other risk factors in middle-aged and elderly patients. The association between MetS as a cluster and WMLs was not driven by MetS components.

Identification of microRNAs and target genes involved in serous ovarian carcinoma and their influence on survival

AIMS

To identify the expression of key microRNAs and their predicted target genes involved in serous ovarian carcinoma (SOC) and correlation between miRNAs and prognosis.

MATERIALS AND METHODS

The authors used quantitative polymerase chain reaction (qPCR) to detect the expression of miR-145, miR-143, miR-146a, miR-93, miR-29a, miR-18a, and miR-200a in tissues of 56 primary SOC patients and 30 benign lesion patients. Four protein (MUC1, FAP, MMP2, MMP9) expressions were identified by western blotting and immunohistochemical stain. The Kaplan-Meier method was used to estimate the relationship of these miRNAs with overall survival rate.

RESULTS

In SOC tissue, expression of miR-200a, miR-93, miR-146a, and miR-18a were up-regulated, while miR-145, miR-143, miR-29a were down-regulated. MUC1, FAP, MMP2, and MMP9 were overexpressed in SOC. MiR-143 or miR-145 higher expressed patients had significantly higher overall survival (OS) rates, while miR-93 or miR-200a lower expressed patients also had higher OS rates.

DISCUSSION

These results suggested that several miRNAs and their regulated target transcripts may have important roles in the initiation and development of SOC. MiR-145/miR-143, miR-200a, and miR-93 could be used as prognostic biomarkers.

Characteristics of diagnosis and therapy of adolescent malignant ovarian tumors

BACKGROUND

To improve the early diagnosis rate of adolescent malignant ovarian tumors, avoid misdiagnosis, select proper therapy, avoid excessive therapy, and render therapy more tolerable.

MATERIALS AND METHODS

A comprehensive review of adolescent malignant ovarian tumors, such as types, difficulties of early diagnosis, therapeutic principles, prognosis, fertility preserving through the authors' clinical experience, with reference to Chinese and international literatures.

RESULTS AND CONCLUSION

The majority of adolescent malignant tumors are malignant germ cell, the malignancy is high and it is difficult to diagnose in the early stage, likely to be ignored. Their diagnosis is therefore fundamental, while selecting the most appropriate therapeutic approach that also considers fertility-sparing without compromising prognosis and avoiding over-treatment.

Abstract P2-05-19: Pathway-based analysis of breast cancer

Objective: Although HER2 and ER pathways are predominant pathways altered in breast cancer, it is now well accepted that many other signaling pathways are also involved in the pathogenesis of breast cancer, especially in triple negative breast cancer. The understanding of these additional pathways may assist in identifying new therapeutic approaches for breast cancer.

Methods: 13 invasive ductal carcinoma tissues and 5 benign breast tissues were analyzed for the mRNA expression level of 1243 cancer pathway-related genes using SmartChip (WaferGen, CA), a real-time PCR-base method. In addition, the levels of 154 cancer pathway-related proteins and phosphoproteins were measured using our innovative Protein Pathway Array.

Results: Out of 1,243 mRNAs, 68.7% were detected in breast cancer and 73 mRNAs were statistically significant between benign and cancer tissues. Of these mRNAs, 105 only expressed in breast cancer tissues and 33 mRNAs only expressed in normal breast tissues. Out of 154 proteins and phosphoproteins, 39% were detected in cancer tissues and 50 proteins were significantly differentiated between tumor and normal tissues. Interestingly, only 3 genes (CDK6, Vimentin and SLUG) showed decrease of both protein and mRNA. Six proteins (BCL6, CCNE1, PCNA, PDK1, SRC and XIAP) showed differentially expressed between tumor and normal tissues but no differences were observed at mRNA levels. Analyses of mRNA and protein data using Ingenuity Pathway Analysis showed more 15 pathways were altered in breast cancers and 6 of them shared between mRNAs and proteins, including p53, IL17, HGF, NGF, PTEN and PI3K/AKT.

Conclusion: There is a broad dysregulation of various pathways in breast cancer both at protein levels and mRNA levels. It is important to note that mRNA expression does not correlate with protein level, suggesting that different regulation mechanisms between proteins and mRNAs.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P2-05-19.

Terahertz wavefronts measured using the Hartmann sensor principle

We demonstrate for the first time that the Hartmann wavefront sensor (HWS) principle can be applied for characterizing the wavefronts of terahertz (THz) electromagnetic radiation. The THz Hartmann wavefront sensor consists of a metallic plate with an array of holes and a two-dimensional scanable pyro-electric detector. The THz radiation with different wavefronts was generated by a far-infrared gas laser operated at 2.5 THz in combination with a number of objects that result in known wavefronts. To measure the wavefront, a beam passing through an array of holes generates intensity spots, for which the positions of the individual spot centroids are measured and compared with reference positions. The reconstructed wavefronts are in good agreement with the model expectations.

Synthesis of solasodine glycoside derivatives and evaluation of their cytotoxic effects on human cancer cells

Solasodine glycosides, such as solamargine, have been proved to be very important anti-cancer agents. In order to discover more potent cytotoxic agents and explore the preliminary structure activity relationship, a new series of solasodine glycosides 2-9 were synthesized via a transglycosylation strategy, and their cytotoxic activity against a panel of human cancer cell lines (MCF-7, KB, K562, and PC3 cells) were evaluated by MTT assays. The results indicated that compounds 2, 8, and 9 with the substitute moiety of rhamnose, 2-hydroxyethoxymethyl, and 1,3-dihydroxypropan-2-yloxy-methyl, respectively, exhibited quite strong anticancer activity. The underlying mechanism tests demonstrated that these compounds could induce apoptosis detected by DAPI staining, and Annexin V and propidium iodide binding. Cell cycle analysis indicated that the cancer cells were predominantly arrested at the G2/M phase when exposure to these compounds was examined by flow cytometry. These compounds may serve as lead candidates in the development of novel chemotherapeutics for cancer treatment.

Molecular cloning and expression analysis of heat-shock protein 70 in orange-spotted grouper Epinephelus coioides following heat shock and Vibrio alginolyticus challenge

In this study, the complementary (c)DNA encoding heat-shock protein 70 (Hsp70) of orange-spotted grouper Epinephelus coioides (OsgHsp70) was cloned. OsgHsp70 was 2206 bp and encoded 652 amino acids with predicted molecular mass of 70·89 kDa and theoretical isoelectric point of 5·48. Three Hsp70 family signatures, bipartite nuclear localization signal sequence (NLS) and cytoplasmic characteristic motif (EEVD) were observed in the OsgHsp70, which shared high similarity in amino-acid sequences with the Hsp70 gene of other vertebrates. The results indicated that the OsgHsp70 is a member of the heat-shock protein 70 family. The Hsp70 messenger (m)RNA expressions were quantified by real-time PCR following heat shock, bacterial infection and immunization with formalin-killed Vibrio alginolyticus, a kind of bacterial pathogen that causes septicaemia. Hsp70 mRNA expression in gill, kidney, spleen, thymus gland, muscle and total-blood samples increased at first and then decreased gradually following heat shock. A similar time-dependent pattern was observed following V. alginolyticus pathogen challenge, in which Hsp70 mRNA expression peaked at 24 h after live bacterial infection and 3 days after dead bacterial vaccination. The results indicated that the Hsp70 gene was inducible and involved in the fish immune response.

Long distance measurement with femtosecond pulses using a dispersive interferometer

We experimentally demonstrate long distance measurements with a femtosecond frequency comb laser using dispersive interferometry. The distance is derived from the unwrapped spectral phase of the dispersed interferometer output and the repetition frequency of the laser. For an interferometer length of 50 m this approach has been compared to an independent phase counting laser interferometer. The obtained mutual agreement is better than 1.5 μm (3×10(-8)), with a statistical averaging of less than 200 nm. Our experiments demonstrate that dispersive interferometry with a frequency comb laser is a powerful method for accurate and non-incremental measurement of long distances.

Time-frequency distribution of interferograms from a frequency comb in dispersive media

We investigate general properties of the interferograms from a frequency comb laser in a non-linear dispersive medium. The focus is on interferograms at large delay distances and in particular on their broadening, the fringe formation and shape. It is observed that at large delay distances the interferograms spread linearly and that its shape is determined by the source spectral profile. It is also shown that each intensity point of the interferogram is formed by the contribution of one dominant stationary frequency. This stationary frequency is seen to vary as a function of the path length difference even within the interferogram. We also show that the contributing stationary frequency remains constant if the evolution of a particular fringe is followed in the successive interferograms found periodically at different path length differences. This can be used to measure very large distances in dispersive media.

Abstract P6-05-05: Signaling Pathways Activated in Her 2 and ER Negative Breast Cancers

Introduction: Breast cancer is the most common cancer in women (192,370 new cases in 2009) and the second leading cause of cancer death (40,000) among women in USA. Current multimodality treatment of breast cancer is based on the level of ER expression and Her 2 gene amplification. However, no effective treatment is currently available for breast cancers with low level expression of ER and no amplification of Her 2 gene. The aim of this study is to identify protein pathways activated in the breast cancer with negative expression of ER and Her 2. Method: Protein Pathway Array was used to assess the level of protein expression and phosphorylation in 71 paired fresh frozen breast samples (tumor and adjacent benign tissue). A total 159 antibodies were evaluated which represent most important signal transduction pathways involved in proliferation, apoptosis, angiogenesis, invasion and metastasis. Several potential therapeutic kinase proteins were also assessed. Results: A total 20 proteins (PCNA, phospho-PTEN, cyclin B1 cyclin E1, CDK6, E-cadherin, NFkB, ect) were differentially expressed between normal and tumor tissues based on the statistical analysis. In Her 2 negative tumors (n=37), 3 proteins were differentially expressed and among them, 2 were up-regulated (CDK6 and HSD1) and 1 was down-regulated (IGF). In ER negative tumors (n=18), 4 proteins (HSD, SK, TDP and Slug) was up-regulated and 1 proteins were down-regulated (E-cadherin). In triple negative tumors (n=13), one protein (E-cadherin) down-regulated and 2 proteins (TDP and HSD) were up-regulated. Furthermore, based on the expression pattern of these proteins, tumors negative for both ER and Her 2 (n=15) can be clustered into 3 groups

Figure 1: Subclassification of breast cancers negative for ER and Her-2 based protein pattern.

Hierarchical clustering analysis of 20 differentially expressed proteins in

15 ER/Her-2 negative breast cancers. The cancers can be separated into 3 subtypes. Red indicates overexpression, green underexpression, black no change, and gray no expression. Each column represents a protein. Each row represents a sample.

Conclusion: Our study showed that distinct sets of signaling pathways activated in ER and Her 2 negative breast cancers. The increased expression of cell cycle progression proteins in Her 2 negative tumors suggests activation of cell proliferation via different growth promotion pathway. Similarly, different cell proliferation pathways are also activated in ER negative tumors. This finding may be used to design future clinical trial based on the activation of different signaling pathways.

Receptor for advanced glycation end products (RAGE) soluble form (sRAGE): a new biomarker for lung cancer

Receptor for advanced glycation end products (RAGE) may be involved in the pathogenesis of cancer progression. Pathological effects mediated via RAGE are physiologically inhibited by soluble RAGE (sRAGE). The aim of this study was to identify sRAGE and RAGE expression profile in lung cancer patients. An ELISA method was used to quantify serum sRAGE in 45 individuals. Additionally, surgical specimens of 28 lung cancer patients were also included for RAGE expression by immunohistochemistry. Serum sRAGE was significantly decreased in lung cancer patients compared with controls (vs. healthy donors, P=0.034; vs. pulmonary tuberculosis patients, P=0.010). Lower sRAGE concentration was negative correlated with lymph node involvement (N0 vs. N1-2, P=0.028). Down regulation of membranous and cytoplasmic expression for RAGE was also lower in lung cancer tissue than in nearby normal lung tissue. Correlation with serum sRAGE concentration and RAGE expression in lung cancer tissue was existed by CV values. The results indicate that serum sRAGE levels are decreased during lung cancer progression and could reflect decreased RAGE expression in tissue. Serum sRAGE may serve as an effective and convenient diagnostic biomarker for lung cancer.

KEYWORDS

sRAGE, serum, RAGE, tissue, lung cancer.

An Ang1-Tie2-PI3K axis in neural progenitor cells initiates survival responses against oxygen and glucose deprivation

Neural progenitor cells (NPCs) have the potential to survive brain ischemia and participate in neurogenesis after stroke. However, it is not clear how survival responses are initiated in NPCs. Using embryonic mouse NPCs and the in vitro oxygen and glucose deprivation (OGD) model, we found that angiopoietin-1 (Ang1) could prevent NPCs from OGD-induced apoptosis, as evidenced by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling and annexin V labeling. Ang1 significantly elevated tunica intima endothelial kinase 2 (Tie2) autophosphorylation level, suggesting the existence of functional Tie2 receptors on NPCs. NPCs under OGD conditions exhibited reduction of Akt phosphorylation, decrease of the Bcl-2/Bax ratio, activation of caspase-3, cleavage of PARP, and downregulation of beta-catenin and nestin. Ang1 reversed the above changes concomitantly with significant rising of survival rates of NPCs under OGD, but all these effects of Ang1 could be blocked by either soluble extracellular domain of Tie2 Fc fusion protein (sTie2Fc) or the phosphoinositide 3-kinase (PI3K) inhibitor 2-(4-morpholinyl)-8-phenyl-1(4H)-benzopyran-4-one (LY294002). Our findings suggest the existence of an Ang1-Tie2-PI3K signaling axis that is essential in initiation of survival responses in NPCs against cerebral ischemia and hypoxia.

High-accuracy long-distance measurements in air with a frequency comb laser

We experimentally demonstrate that a femtosecond frequency comb laser can be applied as a tool for long-distance measurement in air. Our method is based on the measurement of cross correlation between individual pulses in a Michelson interferometer. From the position of the correlation functions, distances of up to 50 m have been measured. We have compared this measurement to a counting laser interferometer, showing an agreement with the measured distance within 2 microm (4x10(-8) at 50 m).

Herpes simplex virus type 2 infection among commercial sex workers in Kunming, Yunnan Province, China

A cross-sectional survey was conducted to determine the sociodemographic correlates of herpes simplex virus type 2 (HSV-2) infection among male and female commercial sex workers in Kunming, Yunnan Province of China. HSV-2 prevalence was 33.0%, human immunodeficiency virus (HIV) infection was 2.4% and hepatitis C virus (HCV) infection was 6.8%. Subjects who were positive for HSV-2 had a significantly higher prevalence of HIV infection (5.5% versus 0.9%, P = 0.002; odds ratio [OR]: 6.4, P = 0.006) and HCV infection (18.7% versus 2.4%, P < 0.001; OR: 7.6, P < 0.001) compared with HSV-2-negative individuals. Risk factors that increased the odds of HSV-2 infection were HIV infection, HCV infection, being female, and having a steady sex partner within the last six months (P < or = 0.01). In a multivariate analysis, being female (OR: 6.6, P < 0.001), having HCV infection (OR: 5.9, P < 0.001) and having a sex partner within the last six months (OR: 2.2, P < 0.05) showed greater odds of being infected with HSV-2. A strong relationship was found between HSV-2, HIV and HCV infections.

TRPV1 receptors in the CNS play a key role in broad-spectrum analgesia of TRPV1 antagonists

Vanilloid receptor type 1 (TRPV1) is a ligand-gated nonselective cation channel that is considered to be an important integrator of various pain stimuli such as endogenous lipids, capsaicin, heat, and low pH. In addition to expression in primary afferents, TRPV1 is also expressed in the CNS. To test the hypothesis that the CNS plays a differential role in the effect of TRPV1 antagonists in various types of pain, the analgesic effects of two TRPV1 antagonists with similar in vitro potency but different CNS penetration were compared in vivo. Oral administration of either A-784168 (1-[3-(trifluoromethyl)pyridin-2-yl]-N-[4-(trifluoromethylsulfonyl)phenyl]-1,2,3,6-tetrahydropyridine-4-carboxamide) (good CNS penetration) or A-795614 (N-1H-indazol-4-yl-N'-[(1R)-5-piperidin-1-yl-2,3-dihydro-1H-inden-1-yl]urea) (poor CNS penetration) blocked capsaicin-induced acute pain with the same potency. In complete Freund's adjuvant (CFA)-induced chronic inflammatory pain, oral administration of either compound blocked thermal hyperalgesia with similar potency. Furthermore, intraplantar or intrathecal administration of A-784168 blocked CFA-induced thermal hyperalgesia, suggesting that both peripheral and CNS TRPV1 receptors may play a role in inflammatory thermal hyperalgesia. The effects of the two TRPV1 antagonists were further assessed in models presumably mediated by central sensitization, including CFA- and capsaicin-induced mechanical allodynia and osteoarthritic pain. In these models, the potency of the two compounds was similar after intrathecal administration. However, when administered orally, A-784168, with good CNS penetration, was much more potent than A-795614. Together, these results demonstrate that TRPV1 receptors in the CNS play an important role in pain mediated by central sensitization. In addition, these results demonstrate that significant CNS penetration is necessary for a TRPV1 antagonist to produce broad-spectrum analgesia.

[Relationship between soil water content and water use efficiency of apple leaves]

The relationship between soil water content and water use efficiency (WUE) of apple tree leaf was examined, and the mechanism of WUE variation was also studied by using pot-culture. The results showed that the WUE was upmost when soil water relative content (SWC) reached 52.0%. The increase of WUE when SWC decreased from 77.2% to 52.0% was mainly caused by the change of stomatal conductance. The decline of carboxylation efficiency resulted in the decrease of WUE when SWC decreased from 52.0% to 20.1%. The WUE returned up after being rewatered, but could not reach the control level within a week. The WUE decreased when the soil was waterlogged, but reached the control level in three days after being waterlogged. After the third day, the WUE decreased gradually with the extending of the time being waterlogged. On the sixth day being waterlogged, the carboxylation efficiency decreased.

Brownian dynamics simulations of interaction between scorpion toxin Lq2 and potassium ion channel

The association of the scorpion toxin Lq2 and a potassium ion (K(+)) channel has been studied using the Brownian dynamics (BD) simulation method. All of the 22 available structures of Lq2 in the Brookhaven Protein Data Bank (PDB) determined by NMR were considered during the simulation, which indicated that the conformation of Lq2 affects the binding between the two proteins significantly. Among the 22 structures of Lq2, only 4 structures dock in the binding site of the K(+) channel with a high probability and favorable electrostatic interactions. From the 4 candidates of the Lq2-K(+) channel binding models, we identified a good three-dimensional model of Lq2-K(+) channel complex through triplet contact analysis, electrostatic interaction energy estimation by BD simulation and structural refinement by molecular mechanics. Lq2 locates around the extracellular mouth of the K(+) channel and contacts the K(+) channel using its beta-sheet rather than its alpha-helix. Lys27, a conserved amino acid in the scorpion toxins, plugs the pore of the K(+) channel and forms three hydrogen bonds with the conserved residues Tyr78(A-C) and two hydrophobic contacts with Gly79 of the K(+) channel. In addition, eight hydrogen-bonds are formed between residues Arg25, Cys28, Lys31, Arg34 and Tyr36 of Lq2 and residues Pro55, Tyr78, Gly79, Asp80, and Tyr82 of K(+) channel. Many of them are formed by side chains of residues of Lq2 and backbone atoms of the K(+) channel. Thirteen hydrophobic contacts exist between residues Met29, Asn30, Lys31 and Tyr36 of Lq2 and residues Pro55, Ala58, Gly79, Asp80 and Tyr82 of the K(+) channel. These favorable interactions stabilize the association between the two proteins. These observations are in good agreement with the experimental results and can explain the binding phenomena between scorpion toxins and K(+) channels at the level of molecular structure. The consistency between the BD simulation and the experimental data indicates that our three-dimensional model of Lq2-K(+) channel complex is reasonable and can be used in further biological studies such as rational design of blocking agents of K(+) channels and mutagenesis in both toxins and K(+) channels.

Metal ion adducts in the structural analysis of ginsenosides by electrospray ionization with multi-stage mass spectrometry

The effect of metal (Li+, Na+, K+, Ag+) cationization on collision-induced dissociation of ginsenosides was investigated by electrospray ionization mass spectrometry combined with multi-stage mass spectrometry (ESI-MS(n)). The fragments of sodiated and lithiated molecules give valuable structural information regarding the nature of the aglycone and the sequence and linkage information of sugar moieties. However, the number and relative abundances of fragment ions from lithiated ginsenosides are significantly greater than for the sodiated species. The K+ adducts undergo glycosidic cleavages and very limited cross-ring reactions. The silver ion adducts fragment mainly through glycosidic cleavages.

Efficient shoot regeneration from hairy roots of Antirrhinum majus L. transformed by the rol type MAT vector system

 Eleven independent GUS-positive hairy roots were induced by co-cultivation of leaf explants of Antirrhinum majus L. with Agrobacterium tumefaciens strain GV2260 containing the rol type MAT vector pNPI702. The MAT vector pNPI702 possesses a GUS gene under the 35 S promoter and a removal element in which the 7.6-kb DNA fragments containing the rolA, B, C and D genes and recombinase gene with a 35 S promoter are located between two directly oriented recombination site sequences. A total of 326 adventitious shoots regenerated from 11 independent hairy root lines cultured on 1/2MS medium without plant growth regulators at 25  °C under a 16/8 h (day/night) photoperiod after 8 weeks of stock-culture of hairy roots and 4 weeks of culture of the green segments of hairy roots. Regenerated plants showed either a normal or dwarf morphology. GUS activity was observed in the hairy roots and regenerated shoots. The presence of the GUS gene in the regenerated, morphologically normal plants was confirmed by PCR analysis.

Competence in early adult romantic relationships: a developmental perspective on family influences

The present prospective, longitudinal study of 193 young adults (85 men, 108 women, M = 20.7 years old) and their partners in ongoing romantic relationships in 1997 was initiated in 1989, when the 193 target youths were in the 7th grade. On the basis of the model for the development of early adult romantic relationships (DEARR; C. Bryant & R. D. Conger, in press), the authors hypothesized that interactional processes in the family of origin would predict interpersonal skills by the target youths, which would be positively related to the early adult couple's relationship quality. Observational ratings showed that nurturant-involved parenting in the family of origin predicted behaviors by the target youth to a romantic partner that were warm, supportive, and low in hostility. These competent behaviors of the target youth were positively associated with relationship quality for the early adult couple and also mediated or explained the connection between parenting and relationship quality.

Competence in early adult romantic relationships: a developmental perspective on family influences

The present prospective, longitudinal study of 193 young adults (85 men, 108 women, M = 20.7 years old) and their partners in ongoing romantic relationships in 1997 was initiated in 1989, when the 193 target youths were in the 7th grade. On the basis of the model for the development of early adult romantic relationships (DEARR; C. Bryant & R. D. Conger, in press), the authors hypothesized that interactional processes in the family of origin would predict interpersonal skills by the target youths, which would be positively related to the early adult couple's relationship quality. Observational ratings showed that nurturant-involved parenting in the family of origin predicted behaviors by the target youth to a romantic partner that were warm, supportive, and low in hostility. These competent behaviors of the target youth were positively associated with relationship quality for the early adult couple and also mediated or explained the connection between parenting and relationship quality.

Competence in early adult romantic relationships: a developmental perspective on family influences

The present prospective, longitudinal study of 193 young adults (85 men, 108 women, M = 20.7 years old) and their partners in ongoing romantic relationships in 1997 was initiated in 1989, when the 193 target youths were in the 7th grade. On the basis of the model for the development of early adult romantic relationships (DEARR; C. Bryant & R. D. Conger, in press), the authors hypothesized that interactional processes in the family of origin would predict interpersonal skills by the target youths, which would be positively related to the early adult couple's relationship quality. Observational ratings showed that nurturant-involved parenting in the family of origin predicted behaviors by the target youth to a romantic partner that were warm, supportive, and low in hostility. These competent behaviors of the target youth were positively associated with relationship quality for the early adult couple and also mediated or explained the connection between parenting and relationship quality.

Rapid identification of saponins in plant extracts by electrospray ionization multi-stage tandem mass spectrometry and liquid chromatography/tandem mass spectrometry

Electrospray ionization multi-stage tandem mass spectrometry (ESI-MS(n)) and liquid chromatography coupled with on-line mass spectrometry (LC/MS/MS) were applied to characterize saponins in crude extracts from Panax ginseng. The MS(n) data of the [M - H](-) ions of saponins can provide structural information on the sugar sequences of the saccharide chains and on the sapogins of saponins. By ESI-MS(n), non-isomeric saponins and isomeric saponins with different aglycones can be determined rapidly in plant extracts. LC/MS/MS is a good complementary analytical tool for determination of isomeric saponins. These approaches constitute powerful analytical tools for rapid screening and structural assignment of saponins in plant extracts.

New reporter cell lines to study macrophage-tropic HIV envelope protein-mediated cell-cell fusion

The infection of human cells by HIV-1 virus can be mimicked by a fusion process between cells expressing the HIV envelope protein (Env) and cells expressing both human CD4 (huCD4) and appropriate human chemokine receptors. In this study, a macrophage-tropic (M-tropic) HIV cell-cell fusion assay was established that utilized huCD4, human CCR5 (huCCR5), and HIV ADAgpl60 as fusion components and a Gal4/VP16-activated luciferase as a reporter system. By combining CHO cells expressing huCD4 and huCCR5 with CHO cells expressing HIV ADAgpl60, a 300-fold increase in luciferase activity could be elicited relative to control. No luciferase activity was detected when HXB2gpl60 (T-tropic) was used instead of ADAgpl60 (M-tropic) as the fusion partner in the assay. Addition of anti-huCD4 (RPA-T4) or anti-huCCR5 (2D7) monoclonal antibodies in the assay significantly inhibited the fusion event; in contrast, an anti-CXCR4 (12G5) monoclonal antibody had little effect, indicating that the fusion assay was huCD4 and huCCR5 dependent. The cell-cell fusion occurred in a time-dependent manner; the maximum luciferase activity was detected about 8 hr after mixing the cells. The fusion events could also be monitored by another reporter system in which Gal4/VP16 activated green fluorescent protein (GFP) was used as the reporter instead of luciferase. In combination with fluorescence microscopy, the GFP reporter system allowed visualization of the fusion events in real time. Compared with previously described HIV fusion models, this system has several advantages, including simplicity, sensitivity, and the ability to allow continuous monitoring of the HIV cell-cell fusion event. Finally, this cell-cell fusion system is easily adapted to study other HIV fusion events.

Ionizing radiation-induced alterations in the electrophysiological properties of Aplysia sensory neurons

It is clear that ionizing radiation can alter neuronal function. Recently it has been suggested that radiation can directly influence neurons and/or the neuronal microenvironment. We have developed a simple in vitro model system utilizing the marine mollusc Aplysia californica to test this hypothesis. We show that ionizing radiation at doses of 5, 10 or 15 Gy produces complex effects on the electrophysiological properties of a population of Aplysia nociceptive sensory neurons at 24 and 48 h post irradiation. These results add support to the notion that ionizing radiation can directly influence neurons and/or the neuronal microenvironment. Furthermore, they demonstrate that Aplysia may be used as a useful model system to study radiation-induced neuronal plasticity.

Simultaneous determination of lipo-alkaloids extracted from Aconitum carmiechaeli using electrospray ionization mass spectrometry and multiple tandem mass spectrometry

Electrospray ionization mass spectrometry (ESI-MS) combined with multiple tandem mass spectrometry (MS (n)) has been applied for simultaneously determining lipo-alkaloids from the aconite tubers. ESI-MS can give a very good mass separation for lipo-alkaloid mixture and MS (n) can provide structural information. Accordingly, structures were assigned to 12 known lipo-alkaloids including lipoaconitines, lipomesaconitines, lipodeoxyaconitines, and lipohypaconitines on the base of the information obtained using MS ( n). Also, four new lipo-alkaloids were found and their structures were interpreted using the MS (n) data.

Periaqueductal gray stimulation-induced inhibition of nociceptive dorsal horn neurons in rats is associated with the release of norepinephrine, serotonin, and amino acids

The stimulation of the periaqueductal gray (PAG) produces behavioral analgesia in rats, cats, monkeys, and humans. This analgesia is believed to be mediated by several neurotransmitter systems, including the serotonergic, noradrenergic, glycinergic, gamma-aminobutyric acidergic, and opiatergic systems. The present study was designed to determine whether PAG stimulation produces the release of serotonin (5-HT), norepinephrine (NE), Gly, and gamma-aminobutyric acid in the spinal cord dorsal horn and whether the release of these neurotransmitters by PAG stimulation is associated with a long-lasting inhibition of the evoked nociceptive responses of dorsal horn neurons. The effect of different frequencies of stimuli on the release of neurotransmitters in the spinal cord was also examined. Microdialysis in combination with HPLC was used to measure the concentrations of neurotransmitters in the lumbar dorsal horn before, during, and after electrical stimulation of the PAG. The PAG was stimulated with electrical pulses at 333 Hz first and then at 67 Hz with the same intensity for 27 min, respectively. Both stimulus frequencies produced a significant increase in the release of 5-HT, NE, Gly, and Asp in the spinal dialysate, but the low-frequency stimulus was more potent in causing the release of neurotransmitters. Low-frequency stimulation also significantly increased the release of Glu. The time course of inhibition of dorsal horn neurons induced by long-lasting PAG stimulation corresponded to the time course of neurotransmitter release. Therefore, the results suggest that the long-lasting inhibition induced by PAG stimulation is mediated in part by the release of 5-HT, NE, and inhibitory amino acids in the spinal cord.

Nitric oxide mediates the central sensitization of primate spinothalamic tract neurons

Nitric oxide (NO) has been proposed to contribute to the development of hyperalgesia by activating the NO/guanosine 3',5'-cyclic monophosphate (cGMP) signal transduction pathway in the spinal cord. We have examined the effects of NO on the responses of primate spinothalamic tract (STT) neurons to peripheral cutaneous stimuli and on the sensitization of STT cells following intradermal injection of capsaicin. The NO level within the spinal dorsal horn was increased by microdialysis of a NO donor, 3-morpholinosydnonimine (SIN-1). SIN-1 enhanced the responses of STT cells to both weak and strong mechanical stimulation of the skin. This effect was preferentially on deep wide dynamic range STT neurons. The responses of none of the neurons tested to noxious heat stimuli were significantly changed when SIN-1 was administered. Intradermal injection of capsaicin increased dramatically the content of NO metabolites, NO-2/NO-3, within the dorsal horn. This effect was attenuated by pretreatment of the spinal cord with a nitric oxide synthase (NOS) inhibitor, NG-nitro-L-arginine methyl ester (L-NAME). Sensitization of STT cells induced by intradermal injection of capsaicin was also prevented by pretreatment of the dorsal horn with the NOS inhibitors, L-NAME or 7-nitroindazole. Blockade of NOS did not significantly affect the responses of STT cells to peripheral stimulation in the absence of capsaicin injection. The data suggest that NO contributes to the development and maintenance of central sensitization of STT cells and the resultant mechanical hyperalgesia and allodynia after peripheral tissue damage or inflammation. NO seems to play little role in signaling peripheral stimuli under physiological conditions.

Nitric oxide-mediated spinal disinhibition contributes to the sensitization of primate spinothalamic tract neurons

This study concentrated on whether an increase in spinal nitric oxide (NO) diminishes inhibition of spinothalamic tract (STT) cells induced by activating the periaqueductal gray (PAG) or spinal glycinergic and GABAergic receptors, thus contributing to the sensitization of STT neurons. A reduction in inhibition of the responses to cutaneous mechanical stimuli induced by PAG stimulation was seen in wide dynamic range (WDR) STT cells located in the deep layers of the dorsal horn when these neurons were sensitized during administration of a NO donor, 3-morpholinosydnonimine (SIN-1), into the dorsal horn by microdialysis. In contrast, PAG-induced inhibition of the responses of high-threshold (HT) and superficial WDR STT cells was not significantly changed by spinal infusion of SIN-1. A reduction in PAG inhibition when STT cells were sensitized after intradermal injection of capsaicin could be nearly completely blocked by pretreatment of the dorsal horn with a NO synthase inhibitor, 7-nitroindazole. Moreover, spinal inhibition of nociceptive activity of deep WDR STT neurons elicited by iontophoretic release of glycine and GABA agonists was attenuated by administration of SIN-1. This change paralleled the change in PAG-induced inhibition. However, the inhibition of HT and superficial WDR cells induced by glycine and GABA release did not show a significant change when SIN-1 was administered spinally. Combined with our recent results, these data show that the effectiveness of spinal inhibition can be reduced by the NO/cGMP pathway. Thus disinhibition may constitute one mechanism underlying central sensitization.

Inhibition of primate spinothalamic tract neurons by spinal glycine and GABA is modulated by guanosine 3',5'-cyclic monophosphate

Our recent work has suggested that the nitric oxide/guanosine 3', 5'-cyclic monophosphate (NO/cGMP) signal transduction system contributes to central sensitization of spinothalamic tract (STT) neurons in part by influencing the descending inhibition of nociception resulting from stimulation in the periaqueductal gray. This study was designed to examine further whether activation of the NO/cGMP cascade reduces the inhibition of the activity of STT neurons mediated by spinal inhibitory amino acid (IAA) receptors. Responses of STT cells to noxious cutaneous stimuli were inhibited by iontophoresis of glycine and GABA agonists in anesthetized monkeys. Administration of 8-bromoguanosine-3',5'-cyclophosphate sodium (8-bromo-cGMP), a membrane permeable analogue of cGMP, either by microdialysis or by iontophoresis reduced significantly the IAA-induced inhibition of wide dynamic range (WDR) STT cells in the deep layers of the dorsal horn. The reduction in inhibition lasted for up to 1-1.5 h after the cessation of drug infusion. In contrast, IAA-induced inhibition of WDR STT cells in the superficial dorsal horn and high-threshold (HT) cells in superficial or deep layers was not significantly changed during 8-bromo-cGMP infusion. Iontophoresis of 8-bromo-cGMP onto STT cells produced the same actions as produced by microdialysis of this agent, but the effect was not as long-lasting nor as potent. Finally, an attenuation of the IAA receptor-mediated inhibition of STT cells produced by iontophoretic release of a NO donor, 3-morpholinosydnonimine, could be blocked by pretreatment of the spinal cord with a guanylate cyclase inhibitor, 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one. These results suggest that an increased spinal cGMP level contributes to the sensitization of WDR STT neurons in the deep dorsal horn in part by down-regulating spinal IAA receptors. However, no evidence is provided in this study that the NO/cGMP cascade regulates IAA receptors on HT and superficial WDR neurons. Combined with the preceding studies, our data support the view that NO and cGMP function in the same signal transduction cascade and play an important role in central sensitization.

Quantitative analysis of pethidine using liquid secondary ion and tandem mass spectrometry

A method for the quantatitive determination of pethidine in human urine by liquid secondary ion and tandem mass spectrometry is presented. Quantification was carried out by using ketamine as internal standard. It was found that the collision-induced dissociation (CID) spectrum of the [M + H]+ ion of pethidine exhibited a prominent daughter ion at m/z 220 and ketamine also yielded the same daughter ion at m/z 220. For ((quadrupole)) quantitative analysis, the first quadrupole mass filter was set to transmit m/z 220 and a narrow-range magnet scan yielded a spectrum of parents, including m/z 238 and 248, correspending to ketamine and pethidine, respectively.

Inhibitors of protein-RNA complexation that target the RNA: specific recognition of human immunodeficiency virus type 1 TAR RNA by small organic molecules

TAR RNA represents an attractive target for the intervention of human immunodeficiency virus type 1 (HIV-1) replication by small molecules. We now describe three small molecule inhibitors of the HIV-1 Tat-TAR interaction that target the RNA, not the protein. The chemical structures and RNA binding characteristics of these inhibitors are unique for each molecule. Results from various biochemical and spectroscopic methods reveal that each of the three Tat-TAR inhibitors recognizes a different structural feature at the bulge, lower stem, or loop region of TAR. Furthermore, one of these Tat-TAR inhibitors has been demonstrated, in cellular environments, to inhibit (a) a TAR-dependent, Tat-activated transcription and (b) the replication of HIV-1 in a latently infectious model.

Epigastric antinociception by cervical dorsal column lesions in rats

BACKGROUND

Previous clinical evidence and electrophysiologic studies in the authors' laboratory have implicated the dorsal column (DC) as an important pathway for the transmission of visceral colorectal pain. This study examined, behaviorally and electrophysiologically, the role of the DC in mediating epigastric nociception using a visceral pain model involving duodenal distension in rats.

METHODS

For behavioral testing, the writhing-like responses produced in awake rats by graded intraduodenal balloon distension (0.1 to 0.7 ml) were tested. A DC mechanical lesion at the C2 level or a sham operation (SH, same spinal cord segment exposed but no DC lesion) was performed. The writhing-like responses to duodenal distension were tested again and the rats were compared with other rats with no lesions and with SH rats. For electrophysiologic testing, the extracellular activity of single neurons was recorded in the ventrobasal nucleus of the thalamus in anesthetized rats. The ventrobasal cells that responded to duodenal distension were tested further with this visceral stimulus before and after a lesion of the DC.

RESULTS

The mechanical DC lesion significantly reduced the intensity of the writhing-like responses and increased the threshold volume that would elicit writhing-like responses compared with rats with no lesions and SH rats without any observable neurologic deficit. A lesion of the DC also significantly reduced the responses of ventrobasal cells to duodenal distension.

CONCLUSIONS

The DC plays an important role in signaling epigastric nociception in this experimental model. A mechanical DC lesion can produce significant visceral antinociception in rats.