Biomedical subjects

Ning Wu

Publications and source records attributed to Ning Wu.

At least 19 recordsLinked to original sources

PubMed2026

miR-2116-5p functions as a tumor suppressor in lung adenocarcinoma by targeting ADAM12 and serves as a prognostic biomarker.

BACKGROUND: MicroRNAs play key roles in tumor progression. miR-2116-5p is downregulated in lung adenocarcinoma (LUAD), and this study investigated its prognostic value and functional role in the disease. MATERIALS AND METHODS: A total of 125 LUAD patients contributed tissue samples. miR-2116-5p and ADAM12 expression in tissues and cell lines were detected by RT‑qPCR. Clinicopathological correlations of miR-2116-5p were analyzed using the chi-square test. Kaplan‑Meier and Cox regression were employed to assess prognostic significance. CCK‑8, Transwell, and dual‑luciferase reporter assays were performed to investigate miR‑2116-5p function and its targeting of ADAM12. Rescue experiments validated the functional involvement of ADAM12. RESULTS: Significant downregulation of miR-2116-5p was observed in LUAD tissues and cell lines. Low expression was markedly linked to lymph node metastasis (P = 0.013) and advanced TNM stage (P = 0.002). Patients exhibiting reduced miR-2116-5p levels showed worse overall survival, and it was identified as an independent prognostic factor (HR = 2.521, 95% CI: 1.129-5.628, P = 0.020). Functional experiments showed that increasing miR-2116-5p expression suppressed LUAD cell proliferation, migration, and invasion, whereas its knockdown promoted these processes. ADAM12 was confirmed as a direct target, with expression inversely correlated in LUAD tissues (r = -0.749, P < 0.001). ADAM12 overexpression effectively counteracted the ability of miR-2116-5p to suppress proliferation, migration, and invasion. CONCLUSION: miR‑2116-5p suppresses LUAD progression by targeting ADAM12, suggesting it may serve as a prognostic biomarker and therapeutic target.

Humans↗

PubMed2025

Systematic mining and quantification reveal the dominant contribution of non-HLA variations to acute graft-versus-host disease.

Human leukocyte antigen (HLA) disparity between donors and recipients is a key determinant triggering intense alloreactivity, leading to a lethal complication, namely, acute graft-versus-host disease (aGVHD), after allogeneic transplantation. Moreover, aGVHD remains a cause of mortality after HLA-matched allogeneic transplantation. Protocols for HLA-haploidentical hematopoietic cell transplantation (haploHCT) have been established successfully and widely applied, further highlighting the urgency of performing panoramic screening of non-HLA variations correlated with aGVHD. On the basis of our time-consecutive large haploHCT cohort (with a homogenous discovery set and an extended confirmatory set), we first delineated the genetic landscape of 1366 samples to quantitatively model aGVHD risk by assessing the contributions of HLA and non-HLA genes together with clinical factors. In addition to identifying multiple loss-of-function (LoF) risk variations in non-HLA coding genes, our data-driven study revealed that non-HLA genetic variations, independent of HLA disparity, contributed the most to the occurrence of aGVHD. This unexpected major effect was verified in an independent cohort that received HLA-identical sibling HCT. Subsequent functional experiments further revealed the roles of a representative non-HLA LoF gene and LoF gene pair in regulating the alloreactivity of primary human T cells. Our findings highlight the importance of non-HLA genetic risk in the new era of transplantation and propose a new direction to explore the immunogenetic mechanism of alloreactivity and to optimize donor selection strategies for allogeneic transplantation.

Humans↗

PubMed2006

Involvement of phosphatidylcholine-selective phospholipase C in activation of mitogen-activated protein kinase pathways in imidazoline receptor antisera-selected protein.

Imidazoline receptor antisera-selected protein (IRAS) is considered as a candidate for the I1-imidazoline receptor (I1R), but the signaling pathway mediated by IRAS remains unknown. In our study, the signal transduction pathways of IRAS were investigated in CHO cells stably expressing IRAS (CHO-IRAS), and compared to the native I1R signaling pathways. Rilmenidine or moxonidine (10 nM-100 microM), I1R agonists, failed to stimulate [35S]-GTPgammaS binding in CHO-IRAS cell membrane preparations, suggesting that G protein may not be involved in IRAS signaling pathway. However, incubation of CHO-IRAS with rilmenidine or moxonidine for 5 min could induce an upregulation of phosphatidylcholine-selective phospholipase C (PC-PLC) activity, and an increase in the accumulation of diacylglycerol (DAG), the hydrolysate of PC-PLC, in a concentration-dependent manner. The elevated activation of PC-PLC by rilmenidine or moxonidine (100 nM) could be blocked by efaroxan, a selective I1R antagonist. Cells treated with rilmenidine or moxonidine showed an increased level of extracellular signal-regulated kinase (ERK) phosphorylation in a concentration-dependent manner, which could be reversed by efaroxan or D609, a selective PC-PLC inhibitor. These results suggest that the signaling pathway of IRAS in response to I1R agonists coupled with the activation of PC-PLC and its downstream signal transduction molecule, ERK. These findings are similar to those in the signaling pathways of native I1R, providing some new evidence for the relationship between I1R and IRAS.

Animals↗

PubMed2006

Modulation of agmatine on calcium signal in morphine-dependent CHO cells by activation of IRAS, a candidate for imidazoline I1 receptor.

The present study investigated the effects of agmatine action on imidazoline I1 receptor antisera-selected protein (IRAS), a candidate for imidazoline I1 receptor, on prolonged morphine-induced adaptations of calcium signal and long-lasting alterations in gene expression to further elucidate the role of IRAS in opioid dependence. Two cell lines, Chinese hamster ovary cells expressing mu opioid receptor alone (CHO-mu) and expressing mu opioid receptor and IRAS together (CHO-mu/IRAS), were used. After chronic treatment with morphine for 48 h, naloxone induced a significant elevation of intracellular calcium concentration ([Ca2+]i) in CHO-mu and CHO-mu/IRAS cells. Agmatine (0.01-3 microM) concentration-dependently inhibited the naloxone-precipitated [Ca2+]i elevation when co-pretreated with morphine in CHO-mu/IRAS, but not in CHO-mu. Efaroxan, an imidazoline I1 receptor-preferential antagonist, completely reversed the effect of agmatine in CHO-mu/IRAS. Agmatine (1-10 microM) administration after chronic morphine exposure for 48 h partially decreased the [Ca2+]i elevation in CHO-mu/IRAS which was entirely antagonized by efaroxan, but not in CHO-mu. In addition, agmatine (1 microM) co-pretreated with morphine attenuated the naloxone-precipitated increases of cAMP-responsive element binding protein and extracellular signal-regulated kinase 1/2 phosphorylations and c-Fos expression in CHO-mu/IRAS. These effects were blocked by efaroxan as well. Taken together, these results indicate that the agmatine-IRAS action system attenuates the up-regulations of Ca2+ signal and its downstream gene expression in morphine-dependent model in vitro, providing additional evidence to support the contribution of IRAS to opioid dependence.

Agmatine↗

PubMed2006

A genetically encoded fluorescent amino acid.

The ability to introduce fluorophores selectively into proteins provides a powerful tool to study protein structure, dynamics, localization, and biomolecular interactions both in vitro and in vivo. Here, we report a strategy for the selective and efficient biosynthetic incorporation of a low-molecular-weight fluorophore into proteins at defined sites. The fluorescent amino acid 2-amino-3-(5-(dimethylamino)naphthalene-1-sulfonamide)propanoic acid (dansylalanine) was genetically encoded in Saccharomyces cerevisiae by using an amber nonsense codon and corresponding orthogonal tRNA/aminoacyl-tRNA synthetase pair. This environmentally sensitive fluorophore was selectively introduced into human superoxide dismutase and used to monitor unfolding of the protein in the presence of guanidinium chloride. The strategy described here should be applicable to a number of different fluorophores in both prokaryotic and eukaryotic organisms, and it should facilitate both biochemical and cellular studies of protein structure and function.

Alanine↗

PubMed2006

In-Gel Stable-Isotope Labeling (ISIL): a strategy for mass spectrometry-based relative quantification.

Most proteomics approaches for relative quantification of protein expression use a combination of stable-isotope labeling and mass spectrometry. Traditionally, researchers have used difference gel electrophoresis (DIGE) from stained 1D and 2D gels for relative quantification. While differences in protein staining intensity can often be visualized, abundant proteins can obscure less abundant proteins, and quantification of post-translational modifications is difficult. A method is presented for quantifying changes in the abundance of a specific protein or changes in specific modifications of a protein using In-gel Stable-Isotope Labeling (ISIL). Proteins extracted from any source (tissue, cell line, immunoprecipitate, etc.), treated under two experimental conditions, are resolved in separate lanes by gel electrophoresis. The regions of interest (visualized by staining) are reacted separately with light versus heavy isotope-labeled reagents, and the gel slices are then mixed and digested with proteases. The resulting peptides are then analyzed by LC-MS to determine relative abundance of light/heavy isotope pairs and analyzed by LC-MS/MS for identification of sequence and modifications. The strategy compares well with other relative quantification strategies, and in silico calculations reveal its effectiveness as a global relative quantification strategy. An advantage of ISIL is that visualization of gel differences can be used as a first quantification step followed by accurate and sensitive protein level stable-isotope labeling and mass spectrometry-based relative quantification.

Chromatography, Liquid↗

PubMed2006

Detection of small pulmonary nodules using direct digital radiography and picture archiving and communication systems.

PURPOSE: To evaluate the detection of small pulmonary nodules, in the diameter range of 5.4 to 15 mm, using direct digital chest imaging and soft copy interpretation on picture archiving and communication systems. MATERIALS AND METHODS: The results of clinical computed tomography (CT) scans of the thorax were retrospectively reviewed from our radiology information system and picture archiving and communication systems archives. Patients with CT studies containing between 1 and 6 nodules, who also had a digital chest examination within 1 month of the CT scan were selected. Thirty patients with suitable nodules and 30 without nodules were included and form the data base for this study. The nodules were between 5.4 and 15 mm in average diameter. Four separate observers independently viewed the frontal and lateral chest studies of the 60 patients. The presence or absence of nodules was determined. Data were analyzed with Kappa, McNemar and Fischer exact tests for agreement and differences between observers, nodule size, and nodule zone. RESULTS: A total of 42 nodules between 5.4 and 15 mm were present. The overall detection rate for the 4 observers was 41.7%. For nodules between 5.4 and 8 mm the detection rate was 26.2%. Agreement between observer's detection was poor to moderate. Differences between observers for both nodule size and zone were not significant. Only 1 observer had a relationship between nodule detection and nodule size. CONCLUSIONS: Observer detection of pulmonary nodules in the range of 5 to 15 mm using current digital radiography systems is not reliable in the confusing environment of the lung. Additional modification of these systems is required to increase nodule conspicuity.

Adult↗

PubMed2006

CT screening for lung cancer: prevalence and incidence of mediastinal masses.

PURPOSE: To determine the frequency and natural course of mediastinal masses in asymptomatic people at high risk for lung cancer who were undergoing computed tomographic (CT) screening. MATERIALS AND METHODS: Informed consent and institutional review board approval for this HIPAA-compliant study were obtained at each participating institution. All documented mediastinal masses among the 9263 baseline and 11 126 annual repeat screenings performed in the Early Lung Cancer Action Project (ELCAP) and its successor project, the New York ELCAP, were identified. Two radiologists confirmed all cases, identified the location and measured the diameter (average of length and width) of each mass, and reviewed all subsequent CT and clinical and surgical results. The prevalence and incidence of mediastinal masses were then determined. RESULTS: Of the 9263 individuals, 71 had a mediastinal mass seen at baseline screening (prevalence of 0.77%). Of the 71 masses, 41 were thymic, 16 were thyroidal, two were esophageal cancers, six were tracheal-esophageal diverticula, and six were other masses. Among the 11 126 annual repeat screenings, only one new mediastinal mass was identified (incidence of 0.01%). This suggests a long average duration for mediastinal masses in asymptomatic people. Among the 41 thymic masses, five were larger than 3.0 cm in diameter, and all five were resected; of these five, one was a thymic carcinoma and four were noninvasive thymomas. Of the remaining 36 thymic masses, 25 were evaluated at follow-up CT 1 year later: Five had increased in diameter, two had decreased, and 18 remained unchanged. All 16 thyroid masses were due to goiter; none of these were changed at follow-up CT 1 year later. CONCLUSION: Mediastinal masses found in the context of CT screening for lung cancer in asymptomatic people should be approached in a "conservative" manner; this includes thymic masses smaller than 3 cm in diameter, as most of these remain unchanged or even decrease in size.

Adult↗

PubMed2006

CT screening for lung cancer: the value of short-term CT follow-up.

BACKGROUND: Although CT screening for lung cancer results in a diagnosis of stage I > 80% of the time, benign noncalcified nodules are also found. We recognized that some nodules appeared to represent infectious bronchopneumonia or other inflammatory processes, as they resolved on follow-up CT, sometimes after antibiotic therapy. To determine the extent to which short-term CT radiographic follow-up might shorten the workup of nodules, we reviewed our experience with baseline and annual repeat CT screenings performed subsequent to the original Early Lung Cancer Action Project series. METHODS: The initial CT of 1,968 consecutive baseline and 2,343 annual repeat screenings performed from 1999 to 2002 was reviewed. We identified all those recommended for antibiotics on the initial CT who had a follow-up CT within 2 months and determined whether the nodule(s) resolved, decreased in size, remained unchanged, or grew. We then determined whether further follow-up resulted in a diagnosis of cancer. RESULTS: At baseline, among the 41 individuals who had follow-up CT within 2 months of the initial CT, 12 patients (29%) had complete or partial resolution; none of them subsequently received a diagnosis of lung cancer. On annual repeat screening, among the 39 individuals who had follow-up CT within 2 months of the initial CT, 29 patients (74%) had complete or partial resolution; none of them subsequently received a diagnosis of lung cancer. Among the 29 patients with nodules at baseline that were unchanged or grew, a total of 15 cancers were subsequently diagnosed; among the 10 patients on annual repeat scanning, there were 2 cancers. CONCLUSIONS: In asymptomatic individuals undergoing CT screening for lung cancer, short-term follow-up CT within 2 months with or without antibiotics may circumvent the need for further evaluation in some individuals, particularly on annual repeat screening.

Anti-Bacterial Agents↗

PubMed2006

[Eco-anatomical characteristics of Sophora davidii leaves along an elevation gradient in upper Minjiang River dry valley].

This paper studied the eco-anatomical characteristics of Sorphora davidii leaves at the elevations of 1,650, 1,750, 1,850 and 1,950 m in the upper reaches of Minjiang River dry valley. The indices investigated were leaf length (LL), leaf width (LW), LL/ LW, leaf area, leaf thickness, leaf epidermal thickness, leaf palisade mesophyll thickness (P), leaf spongy mesophyll thickness (S), P/S, leaf cutin membrane thickness, leaf stomatal density and area, leaf epidermis cell density and area, and leaf pubescence length and density. The results showed that the leaves of S. davidii were elliptic, with an area 0.144 approximately 0.208 cm2 and a thickness 171.58 approximately 195.83 microm. The mesophyll was significantly differentiated into palisade and spongy. The thickness of palisade mesophyll was 69.83 approximately 82.42 microm, that of spongy mesophyll was 62.00 approximately 80.67 microm, and P/S was 1.14 approximately 1.01. Upper epidermal thickness was 14.03 approximately 15.33 microm, while lower epidermal thickness was 13.88 approximately 16.17 microm. The stomatal density, stomatal area, epidermis cell density, epidermis cell area, pubescence length, and pubescence density were 13.71 approximately 15.02 mm(-2), 249.86 approximately 280.43 microm2, 160.54 approximately 178.43 mm(-2), 557.43 approximately 626.85 microm2, 186.51 approximately 260.99 microm, and 18.29 approximately 32.27 mm(-2), respectively. With increasing elevation, the leaf area, leaf thickness, palisade mesophyll thickness, spongy mesophyll thickness, stomatal area, epidermis cell area and pubescence density were increased, while cutin membrane thickness, epidermis cell density, pubescence length, and stomatal density were decreased. There was no significant difference in LL/LW, P/S, epidermal thickness and stomatal density along the elevation gradient.

Altitude↗

PubMed2006

[Relationship between endostatin and vascular cell adhesion molecule-1 expressions on bone marrow stromal cells in BMT-mice].

This study was aimed to investigate the relationship between endostatin and vascular cell adhesion molecule-1 (VCAM-1) expressions on bone marrow stromal cells (BMSC) in mice after bone marrow transplantation (BMT) and effect of ligustrazine on their expressions. The mice were randomly divided into 3 groups: normal group (without treatment), saline group (control of BMT) and ligustrazine group (BMT + ligustrazine). BMT mouse models were established. The normal group was not treated, the saline group was given normal saline (0.2 ml/mouse, twice a day) through gastric tube, while the ligustrazine group was given ligustrazine (0.2 ml/mouse, twice a day) also through gastric tube. On day 7, 14, 21 and 28 after BMT, mice were killed by euthanasia. The expression levels of endostatin and VCAM-1 in bone marrow stromal cells were detected by immunohistochemistry and RT-PCR analysis respectively. The results showed that the endostatin protein mainly expressed in nuclei of BMSCs, the VCAM-1 protein mainly expressed in plasma of BMSCs. On day 7, 14, 21 after BMT the expression levels of endostatin mRNA and protein in ligustrazine and saline groups were significantly lower than that in normal group (P < 0.01 or P < 0.05), while their expression levels in ligustrazine group were lower than that in saline group. On day 28 the expression levels in saline group returned to normal, while the expression levels in ligustrazine group not were normalized. On day 7, 14, 21 after BMT the expression levels of VCAM-1 mRNA and protein in ligustrazine and saline groups were significantly lower than that in normal group (P < 0.01 or P < 0.05), but their expression levels in ligustrazine group were significantly lighter than that in saline group (P < 0.01 or P < 0.05). On day 28 the VCAM-1 expression level in ligustrazine group returned to normal, while its expression level in saline group not were normalized. The difference between these two groups was significant (P < 0.01). Correlation analysis revealed that there was a negative correlation between endostatin and VCAM-1 expression in saline group, there was a positive correlation between endostatin and VCAM-1 expression in ligustrazine group. It is concluded that the endostatin can influence hematopoiesis in bone marrow by affecting VCAM-1 expression on BMSC and hindering connection between stromal cells and hematopoietic cells as well as extracellular stroma and hematopoietic cells, while ligustrazine can enhance the adhesion molecule expression on stromal cell surface of bone marrow in BMT-mice, accelerate the homing and proliferation of HSPC in bone marrow after BMT, meanwhile can promote the repair of bone marrow microenvironment, accelerate hematopoietic reconstitution of bone marrow after BMT through feedback regulation of endostatin expression of BMSC in BMT-mice.

Animals↗

PubMed2006

[Effect of ligustrazine on the expression of bFGF in bone marrow stromal cells of mice after BMT].

This study was purposed to investigate the effect of ligustrazine on the expression of bFGF in bone marrow stromal cells (BMSC) and to explore the mechanism of hematopoietic reconstitution after bone marrow transplantation (BMT). The mice were randomly divided into 3 groups: normal group, saline group and ligustrazine group. BMT mouse models were established. The mice of normal group were not treated, the mice of saline group were given normal saline (0.2 ml/mouse, twice a day) through gastric tube, while the mice of ligustrazine group were given ligustrazine (0.2 ml/mouse, twice a day) through gastric tube. On day 7, 14, 21 and 28 after BMT, the femora were taken and the bone marrow mononuclear cell (BMMNC) suspensions were used for the cultivation of bone marrow stromal cells according to Dexter's culture method. The mRNA and protein expressions of bFGF in BMSC were assayed by RT-PCR and Western blot respectively. The results showed that the expression of bFGF in BMSC on the level of mRNA and protein were all reduced significantly after BMT, and increased slowly with the time. On day 7, 14 and 21 after BMT, the expressions of bFGF mRNA and protein in bone marrow stromal cells of ligustrazine group and saline group were lower than that in bone marrow stromal cells of normal group, but the expressions of bFGF mRNA and protein in ligustrazine group were obviously higher than that in saline group (P < 0.01 or P < 0.05). On day 28 after BMT, the expressions of bFGF mRNA and protein in ligustrazine group returned to normal level, while the expressions of bFGF mRNA and protein in saline group not returned to normal level, there was significant difference between these two groups. It is concluded that ligustrazine can enhance bFGF expression level in bone marrow stromal cells after syngeneic bone marrow transplantation in mice, which confirms that ligustrazine can enhance the repair of bone marrow microvessels, improve bone marrow microenvironment and promote hematopoietic reconstitution.

Animals↗

PubMed2006

[Antisense oligonucleotide targeting endostatin enhances hematopoiesis reconstitution in BMT mice].

OBJECTIVE: To explore the effect of antisense oligonucleotide targeting endostatin (endostatin-ASON) transfecting bone marrow stromal cells ( BMSC) on hematopoiesis reconstitution in BMT mice. METHODS: Inhibition of endostatin / VCAM-1 protein and mRNA expression was investigated by transfection of antisense oligonucleotide targeting endostatin with confocal microscopy, Western blot and RT-PCR. Bone marrow stromal cells were cultured and divided into 4 groups: group (1) without any treatment; group (2) BMT only; group (3) BMT + endostatin-ASON transfection; group (4) BMT + endostatin scrambled sequence transfection. RESULTS: (1) Endostatin-ASON was successfully introduced into BMSC in vitro, and the transfecting rate was 86% ;(2) After Endostatin-ASON transfected into BMSC, the expression of Endostatin mRNA and its protein on the BMSC was signficantly inhibited at different time point after BMT [the grey value of Endostatin was (0.09 +/- 0.03) - (1.44 +/- 1.19) and (0.02 + 0.02) - (0.14 +/- 0.05), respectively] (P < 0.01 and P < 0.05); (3) Transfecting with Endostatin-ASON effectively promoted the expression of VCAM-1 mRNA and its protein on the BMSC [the gray value of VCAM-1 was (1.60 +/- 0. 92) - (8.05 +/- 0.87) and (0.07 +/- 0.02) - (0.67 +/- 0.09) , respectively] (P <0.01 and P <0.05) ; (4) There was no effects of transfecting Endostatin scrambled sequence on the expression of Endostatin and VCAM-1 on the BMSC (P > 0.05). CONCLUSION: Endostatin-ASON could inhibit Endostatin expression and enhance VCAM-1 expression in BMSC after syngeneic-BMT in mice, which might be one of the mechanisms underlying the endostatin-ASON accelerating hematopoiesis reconstitution after allogeneic-BMT.

Animals↗

PubMed2005

Electric-field-induced patterns in thin polymer films: weakly nonlinear and fully nonlinear evolution.

A thin polymer melt on a substrate can be unstable to an electric field normal to the interface, a phenomenon that can be harnessed as a patterning technique with a range of potential applications. Motivated by the variety of patterns observed in experiments for polymers under both unpatterned and patterned masks, we describe here, from theoretical and numerical analyses, how nonlinear effects govern the growth of the instability and determine the final patterns. In particular, we discuss the nonlinear growth in terms of interactions among different Fourier modes and show that the second- and third-order nonlinearities favor the growth of hexagonal patterns under a featureless mask, in agreement with experimental observations. Also, numerical simulations based on the fully nonlinear model validate the prediction of the weakly nonlinear analysis: hexagonal patterns do emerge under an unpatterned mask. Furthermore, in one-dimensional simulations, we demonstrate the energetic evolution of this patterning process and reveal several "kinetically stable structures" along the path to the thermodynamically stable state. Two-dimensional simulations allow us to study the effects of both mask patterns and the initial film thickness. Generally, patterns on the mask guide the growth such that the pattern conforms to the geometric shapes. Interestingly, a small cylindrical protrusion at the center of the mask can produce exactly the same pattern as a large, flat, circular protrusion. The initial film thickness or the thickness ratio of the polymer layer to the air gap plays an important role in determining the final pattern formed. Finally, we demonstrate, by two simple examples, that the simulations can provide insights on "smart" mask designs for producing large areas of well-ordered patterns.

Journal Article↗

PubMed2005

IRAS, a candidate for I1-imidazoline receptor, mediates inhibitory effect of agmatine on cellular morphine dependence.

Agmatine, an endogenous ligand for the I1-imidazoline receptor, has previously been shown to prevent morphine dependence in rats and mice. To investigate the role of imidazoline receptor antisera-selected protein (IRAS), a strong candidate for I1R, in morphine dependence, two CHO cell lines were created, in which mu opioid receptor (MOR) was stably expressed alone (CHO-mu) or MOR and IRAS were stably co-expressed (CHO-mu/IRAS). After 48 h administration of morphine (10 microM), naloxone induced a cAMP overshoot in both cell lines, suggesting cellular morphine dependence had been produced. Agmatine (0.1-2.5 microM) concentration-dependently inhibited the naloxone-precipitated cAMP overshoot when co-pretreated with morphine in CHO-mu/IRAS, but not in CHO-mu. Agmatine at 5-100 microM also inhibited the cAMP overshoot in CHO/mu and CHO-mu/IRAS. Efaroxan, an I1R-preferential antagonist, completely blocked the effect of agmatine on the cAMP overshoot at 0.1-2.5 microM in CHO-mu/IRAS, while partially reversing the effects of agmatine at 5-100 microM. L-type calcium channel blocker nifedipine entirely mimicked the effects of agmatine at high concentrations on forskolin-stimulated cAMP formation in CHO-mu and naloxone-precipitated cAMP overshoot in morphine-pretreated CHO-mu. Therefore, IRAS, in the co-transfected CHO-mu/IRAS cell line, appears necessary for low concentrations of agmatine to cause attenuation of cellular morphine dependence. An additional effect of agmatine at higher concentrations seems to relate to both transfected IRAS and some naive elements in CHO cells, and L-type voltage-gated calcium channels are not ruled out. This study suggests that IRAS mediates agmatine's high affinity effects on cellular morphine dependence and may play a role in opioid dependence.

Agmatine↗

PubMed2005

Rotationally invariant pattern recognition by use of linear and nonlinear cascaded filters.

We discuss the merits of using single-layer (linear and nonlinear) and multiple-layer (nonlinear) filters for rotationally invariant and noise-tolerant pattern recognition. The capability of each approach is considered with reference to a two-class, rotation-invariant, character recognition problem. The minimum average correlation energy (MACE) filter is a linear filter that is generally accepted to be optimal for detecting signals that are free from noise. Here it is found that an optimized MACE filter cannot differentiate between the characters E and F in a rotation-invariant manner. We have found, however, that this task is possible when a single optimized linear filter is used to achieve the required response when a nonlinear threshold function is included after the filter. We show that this structure can be cascaded to form a multiple-layer, cascaded filter and that the capability of such a system is enhanced by its increased noise tolerance in the character recognition problem. Finally, we show the capability of a two-layer cascade as a means to detect different species of bacteria in images obtained from a phase-contrast microscope.

Algorithms↗

PubMed2005

The C2 domain of PKCdelta is a phosphotyrosine binding domain.

In eukaryotic cells, the SH2 and PTB domains mediate protein-protein interactions by recognizing phosphotyrosine residues on target proteins. Here we make the unexpected finding that the C2 domain of PKCdelta directly binds to phosphotyrosine peptides in a sequence-specific manner. We provide evidence that this domain mediates PKCdelta interaction with a Src binding glycoprotein, CDCP1. The crystal structure of the PKCdelta C2 domain in complex with an optimal phosphopeptide reveals a new mode of phosphotyrosine binding in which the phosphotyrosine moiety forms a ring-stacking interaction with a histidine residue of the C2 domain. This is also the first example of a protein Ser/Thr kinase containing a domain that binds phosphotyrosine.

Amino Acid Sequence↗

PubMed2005

Mathematical modeling and in vitro study of controlled drug release via a highly swellable and dissoluble polymer matrix: polyethylene oxide with high molecular weights.

A mathematical model is developed to describe the transport phenomena of a water-soluble small molecular drug (caffeine) from highly swellable and dissoluble polyethylene oxide (PEO) cylindrical tablets. Several important aspects in drug release kinetics were taken into account simultaneously in this theoretical model: swelling of the hydrophilic matrix and water penetration, three-dimensional and concentration-dependent diffusion of drug and water, and polymer dissolution. The moving boundary conditions are explicitly derived, and the resulting coupled partial differential equations are solved numerically. In vitro study of swelling, dissolution behavior of PEOs with different molecular weights and drug release are also carried out. When compared with experimental results, this theoretical model agrees with the water uptake, dimensional change and polymer dissolution profiles very well for pure PEO tablets with two different molecular weights. Drug release profiles using this model are predicted with a very good agreement with experimental data at different initial loadings. The overall drug release process is found to be highly dependent on the matrix swelling, drug and water diffusion, polymer dissolution and initial dimensions of the tablets. Their influences on drug release kinetics from PEO with two different molecular weights are also investigated.

Delayed-Action Preparations↗