Biomedical subjects

Ping Wang

Publications and source records attributed to Ping Wang.

At least 19 recordsLinked to original sources

PubMed2026

Low-Dose Radiation-Induced Expression of Exosomal miRNAs in the Serum of Medical Radiation Workers.

Objective: Long-term low-dose ionizing radiation may alter genomes and cause diseases. This study examined serum exosomal miRNA differences among radiation-exposed medical workers by work types. Methods: High-throughput sequencing screened serum exosomal miRNAs in diagnostic radiologists, interventional radiologists, and nuclear medicine doctors. qRT-PCR validated differentially expressed miRNAs. Results: 410 differentially expressed miRNAs, including 102 downregulated and 308 upregulated miRNAs, enriched in 15 KEGG pathways. Four miRNAs were validated. miR-30e-5p, miR-155-5p and miR-486-5p differed significantly among groups(P<0.01).The expression levels of these three miRNAs were lower in the nuclear medicine group than in the diagnostic group (0.25±0.05vs3.89±8.62,0.10±0.15vs7.03±15.75,0.37±0.39vs4.46±9.64;Z=3.542,3.335,9.859;P<0.01), whereas miR-155-5p was lower in the interventional group than in the diagnostic group(1.32±2.43vs 7.03±15.75;H=11.889,P=0.003), miR-486-5p was higher(9.54±19.39vs4.46±9.64; H=9.859,P=0.007). All four miRNAs showed higher expression in the 14-31-year work-experience group, and all four also showed age-dependent differences, with miR-30d-5p and miR-486-5p showing the age-related differences (P<0.01). Combined detection of the four miRNAs improved discrimination among occupational categories (AUC=0.784). Multiple linear regression analysis showed that sex was associated with all four miRNAs, whereas work type was associated with miR-30d-5p and miR-155-5p (P<0.05). Conclusion: Serum exosomal miR-30e-5p, miR-155-5p, and miR-486-5p are promising biomarkers for monitoring radiation-induced damage, supporting occupational protection and health management.

exosomes↗

PubMed2026

Integrated salivary proteomic and metabolomic analyses reveal molecular characterization and novel biomarker panels of chronic obstructive pulmonary disease.

Chronic obstructive pulmonary disease (COPD) is a respiratory disorder characterized by chronic inflammation, oxidative stress, and metabolic dysregulation. The lack of convenient and easily-accessible non-invasive diagnostic approaches remains a major clinical challenge. This study applied an integrated saliva-based proteomic and untargeted metabolomic strategy to identify potential biomarkers for COPD classification. Comprehensive multi-omics analyses identified 225 differentially abundant proteins and 60 differentially abundant metabolites between patients with COPD and healthy controls, including 24 biologically relevant endogenous metabolites. Functional enrichment analyses revealed pronounced dysregulation of mitochondrial energy metabolism, redox homeostasis, lipid remodeling, and inflammatory-related pathways in COPD. By integrating salivary proteomic and metabolomic biomarkers, a stepwise feature selection combined with LASSO logistic regression was used to construct diagnostic models, yielding an optimized biomarker panel consisting of 11 proteins and 2 endogenous metabolites. This integrated model achieved excellent diagnostic performance, with an area under the ROC curve of 0.96. Collectively, these findings demonstrate that integrated salivary proteomic and metabolomic profiling provides a robust, non-invasive approach for COPD classification and offers a promising foundation for the development of biosensor-based diagnostic platforms and early disease detection. SIGNIFICANCE: Chronic obstructive pulmonary disease (COPD) remains a major global health burden. Current diagnostic approaches rely largely on spirometry and clinical assessment, which are limited in sensitivity for early-stage disease and unsuitable for large-scale screening. This study employs an integrated saliva-based proteomic and metabolomic strategy to identify non-invasive biomarkers for COPD classification. Our findings reveal coordinated dysregulation of mitochondrial energy metabolism, redox homeostasis, and lipid remodeling in COPD, highlighting the interconnected roles of metabolic reprogramming, oxidative stress, and inflammation in disease pathophysiology. Notably, a robust diagnostic panel comprising 11 proteins and 2 endogenous metabolites was established, achieving excellent classification performance (AUC of 0.96). To our knowledge, the integrated application of salivary proteomics and metabolomics for COPD diagnosis remains largely unexplored, underscoring the significance and translational potential of our findings.

Humans↗

PubMed2026

Integrated Multi-omics Profiling of 2,4-dinitrochlorobenzene (DNCB)-induced Atopic Dermatitis in Mice Reveals a Coordinated Network of Barrier Dysfunction, Immune Activation, and Metabolic Reprogramming.

Atopic dermatitis (AD) is caused by a combination of epidermal barrier defect and immune imbalance. However, the molecular networks between these structural abnormalities and metabolic variations are unclear. This study aim of this research was to examine the concurrent molecular alterations in skin barrier damage and metabolic disorders in an AD-like mouse model by a multi-omics strategy. A 2,4-dinitrochlorobenzene (DNCB)-induced AD-like mouse model was established and the skin tissues were examined through the combination of transcriptomic, quantitative proteomic, and metabolomic analyses. Cross-omics correlation and network analyses were performed to identify consistently abnormal molecular pathways and crucial regulatory molecules. DNCB treatment caused severe epidermal hyperplasia, and prominent infiltration of CD3⁺ T cells, F4/80⁺ macrophages, and mast cells. Transcriptomic and proteomic analysis indicated significant disruption in keratinocyte differentiation, extracellular matrix organization, and cornified envelope formation pathways. Combined analysis detected 171 molecules which were simultaneously altered at both mRNA and protein levels, and network analysis identified FLG2 and KRT6B as central barrier-related molecules. Pathway enrichment analysis consistently showed the participation of AMPK and PPAR signaling pathways. Metabolomic analysis also revealed coordinated changes in lipid and amino acid metabolism which were closely associated with cornified envelope-associated genes and collagen-modifying enzymes. These findings indicate a close relationship between barrier, immune and metabolic regulation in DNCB-induced dermatitis and provide a multi-omics resource for future mechanistic studies of atopic skin inflammation.

Animals↗

PubMed2026

Pedigree-assisted genotype imputation enables cost-effective genomic prediction in Penaeus vannamei.

Genomic selection in Penaeus vannamei has long been constrained by the high cost of dense genotyping. To address this limitation, we evaluated genotype imputation from a low-density 1 K panel to a medium-density 55 K panel of the "Yellow Sea Array No. 1" and examined its impact on genomic prediction for harvest body weight in P. vannamei. A four-generation pedigree including 30 great-grandparents, 39 grandparents, 100 parents, and 608 offspring was genotyped using the 55 K panel. A two-step experimental design was implemented to (i) assess the performance of different imputation algorithms under reference population scenarios with varying proportions of siblings, and (ii) compare six alternative reference population structures incorporating parents, ancestors, and siblings. Genotype imputation using the pedigree-based method FImpute v3.0 consistently achieved higher accuracy than the population-based method Beagle v5.5. Using this pedigree-assisted approach, imputation accuracy increased from 0.73 when only parental genotypes were used to 0.84 with the inclusion of 10% siblings, and subsequently plateaued at 0.87-0.90 when sibling representation reached 20%. Across the six reference population structures, imputation accuracy was primarily driven by the availability of parental genotypes, ranging from 0.50 to 0.56 in the absence of parents to 0.88-0.89 when both parents and ancestral generations were included. Accuracy remained high when both parents were available (0.84-0.87 with siblings; 0.73 without siblings) but declined substantially when only one parent was genotyped (0.65-0.68). Imputation accuracy was positively associated with both minor allele frequency (MAF) and linkage disequilibrium (max r2LD), with LD exerting the stronger influence. Heritability estimates derived from imputed 55 K genotypes were highly consistent with those obtained from the original 55 K data (0.39 ± 0.14 vs. 0.41 ± 0.14), indicating that genotype imputation did not compromise variance component estimation. In predictive ability analyses, pedigree-based BLUP (PBLUP) achieved higher predictive ability than genomic BLUP (GBLUP) based on the 1 K panel, with predictive abilities of 0.42-0.44 for PBLUP compared with 0.34-0.35 for GBLUP. Using imputed genotypes for genomic prediction further improved predictive ability relative to the true 1 K panel, yielding values ranging from 0.35 to 0.47. Notably, when parental genotypes were included in the reference population, GBLUP based on imputed genotypes surpassed the predictive ability of PBLUP and approached that achieved with the original 55 K genotypes (0.45-0.47). Collectively, these results provide the first empirical evidence that low- to medium-density genotype imputation, combined with pedigree information, can effectively support genomic prediction in P. vannamei. This study establishes a cost-efficient and scalable framework for implementing genomic selection in P. vannamei and provides a practical reference for the application of genomic selection in other aquaculture species with constrained breeding budgets.

Animals↗

PubMed2025

Cancer-testis antigen ACRBP: Cytotoxic response to its HLA-A2 restricted peptide and immune features in ovarian cancer.

While our prior study identified the HLA-A *0201-restricted ACRBP epitope peptide and demonstrated its capacity to generate cytotoxic T lymphocytes (CTLs) in vitro, the clinical relevance of the peptide-induced T cell reactivity in ovarian cancer (OC) patients and the in vivo anti-tumor efficacy of these CTLs remain unexplored. In this study, dendritic cells were sensitized with ACRBP peptide (ALLVLCYSI) and co-cultured with autologous CD8+T cells to induce the production of specific cytotoxic T lymphocytes (Pep-CTLs). The anti-tumor effects of Pep-CTLs were evaluated in SCID mice bearing human ovarian cancer (OC) OVCAR-3 cells. Concurrently, we co-cultured ALLVLCYSI peptide with peripheral blood mononuclear cells (PBMCs) from OC patients (HLA-A2+, ACRBP+) and assessed the number of specific T cells using ELISPOT assays. The immunological impact of the ACRBP peptide against human OC was validated through both in vitro and in vivo experiments. These findings establish a preclinical foundationfor developing ACRBP peptide-based vaccines in OC immunotherapy. To further elucidate ACRBP's role in OC treatment, the study analyzed single-cell RNA sequencing data from 8 OC patients and bulk RNA sequencing data from the Cancer Genome Atlas Project (TCGA) comprising 308 ovarian cancer cases. This analysis aimed to explore the heterogeneity among ACRBP-expressing tumor cell populations and to investigate the correlation between ACRBP expression and immune molecule expression (including MHC and chemokines) alongside chemotherapy response. These insights furnish a theoretical framework supporting the future application of ACRBP in tumor immunotherapy and strategies to prevent immune escape.

Humans↗

PubMed2007

Crosslinked enzyme aggregates in hierarchically-ordered mesoporous silica: a simple and effective method for enzyme stabilization.

alpha-chymotrypsin (CT) and lipase (LP) were immobilized in hierarchically-ordered mesocellular mesoporous silica (HMMS) in a simple but effective way for the enzyme stabilization, which was achieved by the enzyme adsorption followed by glutaraldehyde (GA) crosslinking. This resulted in the formation of nanometer scale crosslinked enzyme aggregates (CLEAs) entrapped in the mesocellular pores of HMMS (37 nm), which did not leach out of HMMS through narrow mesoporous channels (13 nm). CLEA of alpha-chymotrypsin (CLEA-CT) in HMMS showed a high enzyme loading capacity and significantly increased enzyme stability. No activity decrease of CLEA-CT was observed for 2 weeks under even rigorously shaking condition, while adsorbed CT in HMMS and free CT showed a rapid inactivation due to the enzyme leaching and presumably autolysis, respectively. With the CLEA-CT in HMMS, however, there was no tryptic digestion observed suggesting that the CLEA-CT is not susceptible to autolysis. Moreover, CLEA of lipase (CLEA-LP) in HMMS retained 30% specific activity of free lipase with greatly enhanced stability. This work demonstrates that HMMS can be efficiently employed as host materials for enzyme immobilization leading to highly enhanced stability of the immobilized enzymes with high enzyme loading and activity.

Chymotrypsin↗

PubMed2007

Association of interleukin-1 gene polymorphisms with gastric cancer: a meta-analysis.

Previous studies on the association between interleukin-1 (IL-1) genetic polymorphisms and the risk of gastric cancer have produced conflicting results. The purpose of this study was to examine the association between IL-1 genotype and gastric cancer by systematically reviewing the risk of the original studies. Thirty-nine studies, which included 6,863 gastric cancer cases and 8,434 controls, met the inclusion criteria and were included in the meta-analysis. By pooling all the studies identified, the summary odds ratio (OR) of gastric cancer risk associated with IL-1B-511T, -31C, +3954T and IL-1RN*2 was 1.26 (95% confidence interval (CI): 1.03-1.55), 1.00 (95% CI: 0.82-1.22), 1.37 (95% CI: 0.94-2.00) and 1.20 (95% CI: 1.01-1.41), respectively. A stratified analysis showed that IL-1B-511T was associated with an increased risk of gastric cancer (intestinal type) (OR = 1.76, 95% CI: 1.12-2.57). Moreover, IL-1RN*2 was also associated with an increased risk of gastric cancer among Caucasians (OR = 1.30, 95% CI: 1.09-1.54). In conclusion, IL-1B-511 and IL-1RN genetic polymorphisms are associated with an increased risk of developing gastric cancer.

DNA, Neoplasm↗

PubMed2007

Polycyclic aromatic hydrocarbons in the surface sediments from Yellow River, China.

Fourteen surface sediment samples were collected from Lanzhou Reach of Yellow River, China in July 2005. The concentrations of 16 priority polycyclic aromatic hydrocarbons (PAHs) were determined by gas chromatography equipped with a mass spectrometry detector (GC-MS). Total concentrations of the PAHs ranged from 464 to 2621 ng/g dry weight. Sediment samples with the highest PAH concentrations appeared at the downstream of Lanzhou City, where there was the biggest wastewater discharge pipeline from Lanzhou Oil Refinery Factory and Lanzhou Chemical Industry Company. Municipal sewage also contributed to the PAH contamination in the sediments. A correlation existed between the sediment organic carbon content (f(oc)) and the total PAH concentrations (r(2)=0.57), suggesting that sediment organic carbon content played an important role in controlling the PAHs levels in the sediments. According to the observed molecular indices, PAHs contamination in Lanzhou Reach of Yellow River originated both from the high-temperature pyrolytic processes and from the petrogenic source, showing a mixed PAH input pattern, which was also confirmed by the results of a principal component analysis (PCA). According to the numerical effect-based sediment quality guidelines (SQGs) of the United States, the levels of PAHs at most studied sites in Lanzhou Reach of Yellow River should not exert adverse biological effects. Although at some sites (such as S10, S12, etc.) one PAH may exceed the effects range low (ERL), individual PAH did not exceed the effects range median (ERM). The results indicated that sediments in all sites should have potential biological impact, but should have no impairment.

China↗

PubMed2007

The lysophosphatidic acid (LPA) receptors their expression and significance in epithelial ovarian neoplasms.

OBJECTIVE: To investigate the lysophosphatidic acid (LPA) receptors expression situation and their biological significance in human ovarian cancer cell lines and in human epithelial ovarian neoplasms. METHODS: The reverse transcription-polymerase chain reaction (RT-PCR) and Western blotting were employed to measure the expression levels of LPA(1), LPA(2) and LPA(3) mRNA, LPA(2) and LPA(3) protein expression in cultured human ovarian cancer cell lines (3AO, SKOV3 and OVCAR3) and in human epithelial ovarian neoplasms. The immunocytochemical method was used to detect LPA(2) and LPA(3) protein expression in cultured human ovarian cancer cell lines. RESULTS: RT-PCR revealed that all ovarian cancer cell lines expressed LPA(1), LPA(2) and LPA(3) mRNA. The positive rates (100%; 86.4%; 88.2%) of LPA(1) mRNA in normal ovarian tissue, benign tumor and ovarian cancer were no significant difference (p>0.05). The expression level of LPA(1) mRNA was significantly higher in normal ovarian tissue compared with that in benign tumor and in ovarian cancer tissue (p<0.01). LPA(1) expression level was no significant difference in both benign tumor and ovarian cancer tissue (p>0.05). LPA(2) mRNA-positive rates (92.6%) and expression level were significantly higher in ovarian cancer compared with that in benign tumor (31.8%) and in normal ovarian tissue (31.3%) (p<0.01); LPA(2) mRNA-positive rates and expression level were no significant difference in both benign tumor and normal ovarian tissue (p>0.05). LPA(3) mRNA-positive rates (92.6%) and expression level were significantly higher in ovarian cancer compared with that in benign tumor (31.8%) and in normal ovarian tissue (31.3%) (p<0.01), LPA(3) mRNA-positive rates and expression level were no significant difference in both benign tumor and normal ovarian tissue (p>0.05). LPA(1) mRNA expression level was significantly decreased compared with that of LPA(2) and LPA(3) in ovarian cancer (p<0.01); Western blotting clearly revealed that all ovarian cancer cell lines showed LPA(2) and LPA(3) protein. The positive rates and expression level of LPA(2) and LPA(3) protein were significantly increased in ovarian cancer (92.6%; 92.6%) compared with that in benign tumor (45.5%; 45.5%) and that in normal ovarian tissue (43.8%; 43.8%) (p<0.01); LPA(2) and LPA(3) protein-positive rates and expression level were no significant difference in both benign tumor and normal ovarian tissue (p>0.05). Correlation of clinicopathological parameters showed that LPA receptors mRNA and protein expression were associated with FIGO stage and histological grade, except pathologic types and age. The mRNA and protein expression of LPA(2) and LPA(3) in stages III and IV was significantly higher than that in stages I and II epithelial ovarian cancer (p<0.05). The mRNA and protein expression of pathologic grade G(3) was significantly higher compared with grade G(1) (p<0.05). CONCLUSION: LPA(1), LPA(2) and LPA(3) mRNA and protein expressed widely in human epithelial ovarian neoplasms. LPA(2) and LPA(3) may be involved in the development and progression of human ovarian cancer. There was a significant correlation between LPA(2), LPA(3) and invasion and metastasis of epithelial ovarian cancer. LPA(2) and LPA(3) may be a prognostic indicator in patients with epithelial ovarian cancer.

Adolescent↗

PubMed2007

Screening and analysis of the multiple absorbed bioactive components and metabolites of Dangguibuxue decoction by the metabolic fingerprinting technique and liquid chromatography/diode-array detection mass spectrometry.

Based on the metabolic fingerprinting technique and liquid chromatography/diode array detection mass spectrometry (LC/DAD-MS), a method for rapid screening and analysis of the multiple absorbed bioactive components and metabolites of an oral solution of Dangguibuxue decoction (ODD) in rabbit plasma after oral administration of ODD was developed. The results obtained from a comprehensive comparative analysis of the fingerprints of the ODD and its metabolic fingerprints in rabbit plasma indicated that 46 components in the ODD were absorbed into the rabbit's body. Of them, ten components were tentatively identified from their MS and UV spectra and retention behaviors by comparing the results with the reported literature. They were calycosin-7-O-beta-D-glycoside, (6aR,-11aR)-hydroxy-9,10-dimethoxypterocarpan-3-O-beta-D-glycoside, ononin, L-3-hydroxy-9,10-dimethoxypterocarpan, formononetin, (3R)-7,2'-dihydroxy-3',4'-dimethoxyisoflavan, sedanenolide, E-ligustilide, Z-ligustilide, and Z-butylidenephthalide. In addition, 21 components were only found in the metabolic fingerprints, which suggested that they might be metabolites of some components in the ODD. The findings demonstrated that the proposed method could be used to rapidly and simultaneously analyze and screen the multiple absorbed bioactive constituents and metabolites in a formula of traditional Chinese medicines (TCMs) by comparing and contrasting the chromatographic fingerprints with its metabolic fingerprints. This is very important not only for the pharmaceutical discovery process and the quality control of crude drugs, but also to explain the curative mechanism of TCMs.

Administration, Oral↗

PubMed2007

Cell death after co-administration of cisplatin and ethacrynic acid.

Ethacrynic acid (EA) significantly enhances the ototoxic effects of cisplatin. To gain insights into the mechanisms underlying Cis/EA ototoxicity, cochleas were labeled with several apoptotic markers. Cis/EA treatment caused extensive outer hair cell (OHC) and inner hair cell (IHC) damage; OHC lesions decreased from the base towards apex of the cochlea whereas the IHC lesion was relatively constant (25-60%) along the length of the cochlea. Propidium iodide labeled OHC nuclei appeared relatively normal at 6h post-treatment, were condensed and fragmented at 12h post-treatment and were frequently missing 48 h post-treatment. Initiator caspase 8, associated with membrane death receptors, and TRADD, a protein that recruits caspase 8, were present in OHC at 6h post-treatment. Caspase 8 labeling increased from 6 to 24h, but was largely absent at 48 h post-treatment. Executioner caspase 3 and caspase 6, which lie downstream of caspase 8, were expressed in OHC 12-24h post-treatment. Initiator caspase 9, associated with mitochondrial damage, was only expressed at low levels at 48 h post-treatment. These results suggest that the rapid onset of Cis/EA induced programmed cell death is initiated by membrane death receptors associated with TRADD and caspase 8.

Animals↗

PubMed2006

Aluminum tolerance of two wheat cultivars (Brevor and Atlas66) in relation to their rhizosphere pH and organic acids exuded from roots.

Phytotoxicity of aluminum (Al) has become a serious problem in inhibiting plant growth on acid soils. Under Al stress, the changes of rhizosphere pH, root elongation, absorption of Al by wheat roots, organic acids exuded from roots, and some main factors related to Al-tolerant mechanisms have been studied using hydroponics, fluorescence spectrophotometry, and high performance liquid chromatography (HPLC). Two wheat cultivars, Brevor and Atlas66, differing in Al tolerance are chosen in the study. Accordingly, the rhizosphere pH has a positive effect on Al tolerance. Atlas66 (Al-tolerant) has higher capability to maintain high rhizosphere pH than Brevor (Al-sensitive) does. High pH can reduce Al3+ activity and toxicity, and increase the efficiency of exuding organic acids from the roots. More inhibition of root elongation has been found in Brevor because of the exposure of roots to Al3+ solution at low pH. Brevor accumulate more Al in roots than Atlas66 even at higher pH. Al-induced exudation of malic and citric acids has been found in Atlas66 roots, while no Al-induced organic acids have been found in Brevor. These results indicate that the Al-induced secretion of organic acids from Atlas66 roots has a positive correlation with Al tolerance. Comprehensive treatment of Al3+ and H+ indicates that wheat is adversely influenced by excess Al3+, rather than low pH.

Aluminum↗

PubMed2006

Variation of wheat root exudates under aluminum stress.

The wheat (Triticum aestivum L.) cultivar Yangzhou 158 was used as a reference. The wheat root exudates were collected using a hydroponic mode. The changes of the electrolytes, H+, sugar, organic acids, amino acids, and secondary metabolites in wheat root exudates induced by aluminum (Al) were studied. The research results show that Al stress affects wheat root exudation. The secreted electrolytes and sugar increase with the increasing of the external Al3+ concentration. The total amount of secreted amino acids has a specific correlation with the external Al3+ concentration. At first, the amino acids secrete normally, but when Al3+ concentration is over 10 mg.L-1, the amino acid constitution varies obviously. Under Al stress, some original secondary metabolites disappear gradually, and other new secondary metabolites release simultaneously. Increasing the external Al3+ concentration gradually stimulates the exudation of organic acids. The organic acid levels in the wheat root zone increase in response to Al treatments. Active Al ions are accumulated in wheat roots. This Al-dependent variation in wheat root exudates suggests a specific Al-induced response of the wheat.

Aluminum↗

PubMed2006

Mechanism of resistance to Bacillus thuringiensis toxin Cry1Ac in a greenhouse population of the cabbage looper, Trichoplusia ni.

The cabbage looper, Trichoplusia ni, is one of only two insect species that have evolved resistance to Bacillus thuringiensis in agricultural situations. The trait of resistance to B. thuringiensis toxin Cry1Ac from a greenhouse-evolved resistant population of T. ni was introgressed into a highly inbred susceptible laboratory strain. The resulting introgression strain, GLEN-Cry1Ac-BCS, and its nearly isogenic susceptible strain were subjected to comparative genetic and biochemical studies to determine the mechanism of resistance. Results showed that midgut proteases, hemolymph melanization activity, and midgut esterase were not altered in the GLEN-Cry1Ac-BCS strain. The pattern of cross-resistance of the GLEN-Cry1Ac-BCS strain to 11 B. thuringiensis Cry toxins showed a correlation of the resistance with the Cry1Ab/Cry1Ac binding site in T. ni. This cross-resistance pattern is different from that found in a previously reported laboratory-selected Cry1Ab-resistant T. ni strain, evidently indicating that the greenhouse-evolved resistance involves a mechanism different from the laboratory-selected resistance. Determination of specific binding of B. thuringiensis toxins Cry1Ab and Cry1Ac to the midgut brush border membranes confirmed the loss of midgut binding to Cry1Ab and Cry1Ac in the resistant larvae. The loss of midgut binding to Cry1Ab/Cry1Ac is inherited as a recessive trait, which is consistent with the recessive inheritance of Cry1Ab/Cry1Ac resistance in this greenhouse-derived T. ni population. Therefore, it is concluded that the mechanism for the greenhouse-evolved Cry1Ac resistance in T. ni is an alteration affecting the binding of Cry1Ab and Cry1Ac to the Cry1Ab/Cry1Ac binding site in the midgut.

Animals↗

PubMed2006

Phonocardiographic signal analysis method using a modified hidden Markov model.

Auscultation is an important diagnostic indicator for cardiovascular analysis. Heart sound classification and analysis play an important role in the auscultative diagnosis. This study uses a combination of Mel-frequency cepstral coefficient (MFCC) and hidden Markov model (HMM) to efficiently extract the features for pre-processed heart sound cycles for the purpose of classification. A system was developed for the interpretation of heart sounds acquired by phonocardiography using pattern recognition. The task of feature extraction was performed using three methods: time-domain feature, short-time Fourier transforms (STFT) and MFCC. The performances of these feature extraction methods were then compared. The results demonstrated that the proposed method using MFCC yielded improved interpretative information. Following the feature extraction, an automatic classification process was performed using HMM. Satisfactory classification results (sensitivity > or =0.952; specificity > or =0.953) were achieved for normal subjects and those with various murmur characteristics. These results were based on 1398 datasets obtained from 41 recruited subjects and downloaded from a public domain. Constituents characteristics of heart sounds were also evaluated using the proposed system. The findings herein suggest that the described system may have the potential to be used to assist doctors for a more objective diagnosis.

Data Interpretation, Statistical↗

PubMed2006

Improved spatial localization of post-stimulus BOLD undershoot relative to positive BOLD.

The negative blood oxygenation level-dependent (BOLD) signal following the cessation of stimulation (post-stimulus BOLD undershoot) is observed in functional magnetic resonance imaging (fMRI) studies. However, its spatial characteristics are unknown. To investigate this, gradient-echo BOLD fMRI in response to visual stimulus was obtained in isoflurane-anesthetized cats at 9.4 T. Since the middle cortical layer (layer 4) is known to have the highest metabolic and cerebral blood volume (CBV) responses, images were obtained to view the cortical cross-section. Robust post-stimulus BOLD undershoot was observed in all studies, and lasted longer than 30 s after the cessation of 40-60 s stimulation. The magnitude of post-stimulus BOLD undershoot was linearly dependent on echo time with little intercept when extrapolating to TE = 0, indicating that the T2* change is the major cause of the BOLD undershoot. The post-stimulus BOLD undershoot was observed within the cortex and near the surface of the cortex, while the prolonged CBV elevation was observed only at the middle of the cortex. Within the cortex, the largest post-stimulus undershoot was detected at the middle of the cortex, similar to the CBV increase during the stimulation period. Our findings demonstrate that, even though there is significant contribution from pial vessel signals, the post-stimulus undershoot BOLD signal is useful to improve the spatial localization of fMRI to active cortical sites.

Animals↗

PubMed2006

The sodium ion affinities of simple di-, tri-, and tetrapeptides.

The sodium ion affinities (binding energies) of nineteen peptides containing 2-4 residues have been determined by experimental and computational approaches. Na(+)-bound heterodimers with amino acid and peptide ligands (Pep(1), Pep(2)) were produced by electrospray ionization. The dissociations of these Pep(1)-Na(+)-Pep(2) ions to Pep(1)-Na(+) and Pep(2)-Na(+) were examined by collisionally activated dissociation to construct a ladder of relative affinities via the kinetic method. The accuracy of this ladder was subsequently ascertained by experiments using several excitation energies for four peptide pairs. The relative scale was converted to absolute affinities by anchoring the relative values to the known Na(+) affinity of GlyGly. The Na(+) affinities of AlaAla, HisGly, GlyHis, GlyGlyGly, AlaAlaAla, GlyGlyGlyGly, and AlaAlaAlaAla were also calculated at the MP2(full)/6-311 + G(2d,2p) level of ab initio theory using geometries that were optimized at the MP2(full)/6-31G(d) level for AlaAla or HF/6-31G(d) level for the other peptides; the resulting values agree well with experimental Na(+) affinities. Increasing the peptide size is found to dramatically augment the Na(+) binding energy. The calculations show that in nearly all cases, all available carbonyl oxygens are sodium binding sites in the most stable structures. Whenever side chains are available, as in HisGly and GlyHis, specific additional binding sites are provided to the cation. Oligoglycines and oligoalanines have similar binding modes for the di- and tripeptides, but differ significantly for the tetrapeptides: while the lowest energy structure of GlyGlyGlyGly-Na(+) has the peptide folded around the ion with all four carbonyl oxygens in close contact with Na(+), that of AlaAlaAlaAla-Na(+) involves a pseudo-cyclic peptide in which the C and N termini interact via hydrogen bonding, while Na(+) sits on top of the oxygens of three nearly parallel C=O bonds.

Cations↗

PubMed2006

Stabilization of interface-binding chloroperoxidase for interfacial biotransformation.

The stability of an interface-binding chloroperoxidase (CPO) against the deactivation effect of H(2)O(2) was examined. Native CPO was conjugated with polystyrene and thus self-assembled at the water-oil interface. Although the interface-assembled CPO showed improved stability as compared to native CPO, enzyme deactivation as a result of the side effect of H(2)O(2), still limits the overall productivity of the enzyme. Two approaches to further improve the stability of CPO were examined in this work. In one approach, several stabilizers including poly(ethylene glycol) (PEG), PEI, glycerol, sugars and sucrose monododecanoate were used; while in a second approach, in situ generation of hydrogen peroxide (H(2)O(2)) by using glucose oxidase (GOx) was applied. PEG was found exceptional in that it increased both the operational and storage stability of CPO. The best improvement of enzyme productivity was obtained with addition of PEG which led to an increase of 57% for interface-bound CPO and 33% for native CPO. One interesting observation with PEI is that it enhanced the storage stability against H(2)O(2) deactivation, but did not affect the enzyme's operational stability. On the other hand, glucose enhanced the operational stability by two folds, but exhibited no significant effect on storage stability. It was also found that the extended operational lifetime of CPO with in situ generation of H(2)O(2) by GOx was a result that combines the stabilizing effect of glucose and lowered concentration of H(2)O(2). Interestingly, the addition of stabilizers could improve the enantioselectivity of CPO by as much as 10%.

Biotransformation↗