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Biomedical subjects

Wei Hong

Publications and source records attributed to Wei Hong.

At least 19 recordsLinked to original sources
PubMed2026

A fluorescent reporter system for tracking Lactobacillus casei T1 in the murine gastrointestinal tract.

BACKGROUND: Fluorescent reporter systems are useful for studying probiotic colonization and host-microbe interactions. However, their use in lactic acid bacteria is still limited by relatively weak fluorescence signals, insufficient expression stability, and limited resolution during in vivo imaging. In particular, efficient strain-specific tracking systems remain scarce. METHODS: Here, we developed a red fluorescent reporter system for Lactobacillus casei T1 (L.c T1). Lactate dehydrogenase (LDH) promoters identified from the L.c T1 genome were compared with the constitutive P32 promoter to drive expression of the red fluorescent proteins mCherry and mKate. The different promoter-reporter combinations were evaluated in both Escherichia coli DH5α and L.c T1. Fluorescence expression was further examined under different environmental pH conditions. The optimized reporter strains were then evaluated by whole-body fluorescence imaging in living mice and ex vivo imaging of gastrointestinal tissues following oral administration. RESULTS: Among the constructs tested, P32-mKate produced the strongest and most stable fluorescence signal in L.c T1. Fluorescence intensity was influenced by environmental pH, with higher signals observed under mildly alkaline conditions. Whole-body fluorescence imaging showed that the engineered strain could be detected in living mice following oral administration. Ex vivo imaging of gastrointestinal tissues provided clearer localization of fluorescence, with signals mainly detected in the stomach and upper small intestine. CONCLUSION: We established a stable and efficient red fluorescent reporter system for L.c T1. The P32-mKate system enables detection of the engineered strain both in vitro and in vivo and provides a practical approach for tracking probiotic distribution and studying host-microbe interactions in preclinical animal models.

Lactobacillus casei T1↗
PubMed2026

Efficacy and safety of microwave ablation for the treatment of pulmonary osteosarcoma oligometastases.

PURPOSE: Evaluate efficacy and safety of microwave ablation (MWA) for pulmonary osteosarcoma oligometastases. METHODS: Twenty-two patients (median age, 16 years [range, 9-41 years]; 15 male) with pulmonary osteosarcoma oligometastases who underwent MWA from January 2018 to December 2023 were included, with 27 MWA sessions for 36 lung metastases. Technical success and complications were evaluated in all 22 patients, while efficacy and survival were evaluated in 19 patients with 24 MWA sessions in treatment of 32 tumors. Technical success was assessed for each tumor. Local tumor control, progression-free survival (PFS) and overall survival (OS) were estimated using Kaplan-Meier method. Complications were classified using Common Terminology Criteria for Adverse Events version 5.0. RESULTS: Technical success was achieved in all 36 tumors (100.0%). Local tumor progression occurred in five of 32 tumors (15.6%). The estimated local tumor control rates at 12, 24 and 36 months were 96.9%, 86.1% and 81.5%, respectively. No significant difference in local control was found between tumors ≤ 10 mm and > 10 mm (p = .470). Twelve of 19 patients (63.2%) developed new lung metastases outside the ablation area, including one with concurrent newly developed bone metastases and one with recurrence of primary osteosarcoma. The median PFS was 21.5 months. The estimated OS rates at 12, 24 and 60 months were 100.0%, 94.4% and 94.4%, respectively. Major complications occurred in five of 27 sessions (18.5%). CONCLUSIONS: MWA preliminarily demonstrates a high technical success rate, notable local tumor control, promising overall survival and acceptable safety for pulmonary osteosarcoma oligometastases.

Adolescent↗
PubMed2006

Multiscale hybrid linear models for lossy image representation.

In this paper, we introduce a simple and efficient representation for natural images. We view an image (in either the spatial domain or the wavelet domain) as a collection of vectors in a high-dimensional space. We then fit a piece-wise linear model (i.e., a union of affine subspaces) to the vectors at each downsampling scale. We call this a multiscale hybrid linear model for the image. The model can be effectively estimated via a new algebraic method known as generalized principal component analysis (GPCA). The hybrid and hierarchical structure of this model allows us to effectively extract and exploit multimodal correlations among the imagery data at different scales. It conceptually and computationally remedies limitations of many existing image representation methods that are based on either a fixed linear transformation (e.g., DCT, wavelets), or an adaptive uni-modal linear transformation (e.g., PCA), or a multimodal model that uses only cluster means (e.g., VQ). We will justify both quantitatively and experimentally why and how such a simple multiscale hybrid model is able to reduce simultaneously the model complexity and computational cost. Despite a small overhead of the model, our careful and extensive experimental results show that this new model gives more compact representations for a wide variety of natural images under a wide range of signal-to-noise ratios than many existing methods, including wavelets. We also briefly address how the same (hybrid linear) modeling paradigm can be extended to be potentially useful for other applications, such as image segmentation.

Algorithms↗
PubMed2006

[Eco-value level classification model of forest ecosystem based on modified projection pursuit technique].

To optimize the projection function and direction of projection pursuit technique, predigest its realization process, and overcome the shortcomings in long time calculation and in the difficulty of optimizing projection direction and computer programming, this paper presented a modified simplex method (MSM), and based on it, brought forward the eco-value level classification model (EVLCM) of forest ecosystem, which could integrate the multidimensional classification index into one-dimensional projection value, with high projection value denoting high ecosystem services value. Examples of forest ecosystem could be reasonably classified by the new model according to their projection value, suggesting that EVLCM driven directly by samples data of forest ecosystem was simple and feasible, applicable, and maneuverable. The calculating time and value of projection function were 34% and 143% of those with the traditional projection pursuit technique, respectively. This model could be applied extensively to classify and estimate all kinds of non-linear and multidimensional data in ecology, biology, and regional sustainable development.

Ecosystem↗
PubMed2006

[Changes of species diversity in gap gradient of mid-subtropical evergreen broad-leaved forest in Wanmulin Forest].

Based on the investigation of gap and non-gap stands in the mid-subtropical evergreen broad-leaved forest in Wanmulin Nature Reserve of Fujian Province, this paper studied the changes of species diversity in gap gradient and in gaps with different sizes. The results showed that the species richness and diversity decreased gradually from gap center to non-gap, ecological dominance was higher in center and lower in edges, and species evenness was in adverse to ecological dominance. The species diversity in all areas of gap was the maximum when the gap size was 200 to approximately 300 m2.

Biodiversity↗
PubMed2006

[Experimental study of soft X-ray radiation in the interaction of circularly polarized femtosecond-laser-pulse with low pressure xenon].

Using flat-field grating Spectrometer, the ions lines with wavelength between 5 and 60 nm were measured, which were produced by the interaction of circularly polarized 35 femtosecond ultraintense and ultrashort laser-pulse with 5 mm length xenon at the pressure 2 and 3 kPa respectively. The highest transition is the XeVIII: 4d10 5s(2 S1/2)--4d9 5s5p('P3/2) line at wavelength 17.0856 nm at 2 kPa and 3 kPa, the highest transition is 11.343 nm line of XeVII 4d10 5s2(1S0)--4d9 5s5f(3P1) transition. The xenon is ionized to XeVII, XeVIII and XeIX at both pressure.

English Abstract↗
PubMed2006

[The expression of HIF-1 in the early diabetic NOD mice].

PURPOSE: To study the retinal expression of HIF-1 alpha in the diabetic NOD mice. METHODS: NOD mice were divided into normal control group and diabetes group randomly, sacrificed at 2, 4, 6, 8 or 12 weeks. Eyes were enucleated and retinas were isolated and used for western blot, or eyes were sectioned for immunohistochemical staining for HIF-1 alphal. RESULTS: Compared to the normal control group, blood sugar of diabetes mice increased significantly but the weights decreased significantly (P < 0.01). Western blot of retinal lysates showed low levels of HIF-1 alpha at the 6th weeks that were markedly increased at the 12th weeks in the diabetes group. Immunohistochemistry showed increased staining for HIF-1 in the inner retina, but not in the outer retina. CONCLUSION: The retinal HIF-1 alpha levels increasing showed that retinal ischemia happening in the early diabetes. HIF-1 alpha may participate in the secondary damage of retinal ischemia induced by early diabetes.

Animals↗
PubMed2005

Persistent step-flow growth of strained films on vicinal substrates.

We propose a model of persistent step flow, emphasizing dominant kinetic processes and strain effects. Within this model, we construct a morphological phase diagram, delineating a regime of step flow from regimes of step bunching and island formation. In particular, we predict the existence of concurrent step bunching and island formation, a new growth mode that competes with step flow for phase space, and show that the deposition flux and temperature must be chosen within a window in order to achieve persistent step flow. The model rationalizes the diverse growth modes observed in pulsed laser deposition of SrRuO3 on SrTiO3.

Journal Article↗
PubMed2005

FOG-1 recruits the NuRD repressor complex to mediate transcriptional repression by GATA-1.

Transcription factor GATA-1 and its cofactor FOG-1 coordinate erythroid cell maturation by activating erythroid-specific genes and repressing genes associated with the undifferentiated state. Here we show that FOG-1 binds to the NuRD corepressor complex in vitro and in vivo. The interaction is mediated by a small conserved domain at the extreme N-terminus of FOG-1 that is necessary and sufficient for NuRD binding. This domain defines a novel repression module found in diverse transcriptional repressors. NuRD is present at GATA-1/FOG-1-repressed genes in erythroid cells in vivo. Point mutations near the N-terminus of FOG-1 that abrogate NuRD binding block gene repression by FOG-1. Finally, the ability of GATA-1 to repress transcription was impaired in erythroid cells expressing mutant forms of FOG-1 that are defective for NuRD binding. Together, these studies show that FOG-1 and likely other FOG-like proteins are corepressors that link GATA factors to histone deacetylation and nucleosome remodeling.

Amino Acid Motifs↗
PubMed2005

[Experience model for self-thinning process of even-aged pure stands].

Based on the famous -3/2 power rule and generalized Schumacher growth equation, a mathematical model for the density change of even-aged pure stands with time during self-thinning process was presented, and the genetic algorithms was used to fit this nonlinear model. With the collected data from Populus tremula var. davidiana, Pinus yunnanensis and Cunninghamia lanceolata even-aged pure stands, the new model was verified and compared with other models. The results showed that the new model could fit observed data very well, and was very useful in practice. The surplus square, mean relative error, mean absolute error and surplus standard deviation of the new model were all smaller than those of other models, indicating its good qualification in describing stand density change during self-thinning process and its useness in studying forest self-thinning rules. The study also showed that genetic algorithms could give a better global convergence, and be used to estimate the parameters of nonlinear models in ecology, biology and forestry.

Algorithms↗
PubMed2005

[Population structure and its dynamics of rare and endangered plant Alsophila spinulosa].

This paper analyzed the population structure of Alsophila spinulosa in seven plots by the method of spatial sere substituting for time sere, and measured its spatial distribution pattern and dynamics by applying five aggregate indices, C, K, m*, m*/m and Idelta. The spatial distribution pattern with different quadrat scale was examined, according to the map of individual location. The results indicated that the population structure of Alsophila spinulosa in the seven plots presented growing, stable, adult or senescent type, and the spatial distribution pattern was changed from clump to random with the development of Alsophila spinulosa population. The values of dispersion index Idelta of the population decreased with increasing quadrat scale.

Callicarpa↗
PubMed2005

[Dynamics of litterfall and its decomposition and nutrient return of shoot-used Dendrocalamus latiflorus in Mountainous areas of Fujian Province].

This paper studied the dynamics of nutrients in the litters of shoot-used Dendrocalamus latiflorus planted Nanjing State-owned Forest Farm of Fujian Province. The results showed that the litterfall as well as its nutrient concentration and return varied obviously with seasons, and had a double-peak curve change. The weight loss during litter decomposition was very fast at first, and then slowed down. There was a negative exponent correlation between remained weight and decomposition time. During decomposition, the concentrations of N and P in litter showed a trend of increase-decrease-increase, while the K loss was intensive at the early stage, gently at mid-stage, and slight at late stage.

Biomass↗
PubMed2005

[Effect of stand condition improvement on surface soil nutrient losses of hilly land Dendrocalamus latiflorus plantations].

A comparative study on the soil nutrient losses of hilly land shoot-used Dendrocalamus lati florus plantations at the Nanjing stated-owned forest farm, Fujian Province showed that the losses of soil N, P and K under three treatments of stand condition improvement varied with season, and 90% or more of these losses appeared from April to September, with the order of overall ploughing > strip ploughing > control. There was no significant difference of N and P losses among the three treatments, while the K loss was markedly higher under overall ploughing than the control.

China↗
PubMed2004

Evolution of wrinkles in hard films on soft substrates.

A compressively strained film on a substrate can wrinkle into intricate patterns. This Rapid Communication studies the evolution of the wrinkle patterns. The film is modeled as an elastic nonlinear plate and the substrate a viscoelastic foundation. A spectral method is developed to evolve the nonlinear system. When the initial film strains are isotropic, the wrinkles evolve into a pattern with a motif of zigzag segments, in random orientations. When the initial film strains are anisotropic, the wrinkles evolve to an array of herringbones or stripes. The zigzag segments select a width, a length, and an elbow angle that minimize the total elastic energy.

Journal Article↗
PubMed2004

An ste20 homologue in Ustilago maydis plays a role in mating and pathogenicity.

The mitogen-activated protein kinase (MAPK) pathways are conserved from fungi to humans and have been shown to play important roles in mating and filamentous growth for both Saccharomyces cerevisiae and dimorphic fungi and in infectivity for pathogenic fungi. STE20 encodes a protein kinase of the p21-activated protein kinase family that regulates more than one of these cascades in yeasts. We hypothesized that an Ste20p homologue would play a similar role in the dimorphic plant pathogen Ustilago maydis. The full-length copy of the U. maydis gene was obtained from a genomic library; it lacked introns and was predicted to encode a protein of 826 amino acids, whose sequence confirmed its identity as the first Ste20p homologue to be isolated from a plant pathogen. The predicted protein contained both an N-terminal regulatory Cdc42-Rac interactive binding domain and a C-terminal catalytic kinase domain. Disruption of the gene smu1 resulted in a delayed mating response in a mating-type-specific manner and also in a severe reduction in disease production on maize. Unlike the Ustilago bypass of cyclase (ubc) mutations previously identified in genes in the pheromone-responsive MAPK cascade, mutation of smu1 does not by itself act as an extragenic suppressor of the filamentous phenotype of a uac1 mutant. Thus, the direct connection of Smu1p to MAPK cascade function has yet to be established. Even so, Smu1, though not absolutely required for mating, is necessary for wild-type mating and pathogenicity.

Blotting, Northern↗