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Chao Chen

Publications and source records attributed to Chao Chen.

At least 19 recordsLinked to original sources
PubMed2026

Evaluation of the SLC11A1 non-synonymous variant rs17235409 and tuberculosis susceptibility in a multi-ethnic population from southwestern China.

Tuberculosis (TB) remains a major infectious disease burden, and inter-individual heterogeneity in progression from exposure to active disease suggests contributions from host genetic factors. SLC11A1 (formerly NRAMP1) encodes a phagosomal divalent cation transporter implicated in macrophage-mediated antimicrobial defense; the non-synonymous rs17235409 polymorphism (D543N) has been evaluated in multiple populations with inconsistent results. We conducted a retrospective matched case-control study in Qiandongnan, Guizhou Province, China, including 50 patients diagnosed with TB (2022-2023) and 50 healthy controls frequency-matched by ethnicity and selected demographics. Participants were drawn from Miao, Dong, and other minority groups. Among TB cases, the frequencies of the GG, GA, and AA genotypes were 80.0%, 20.0%, and 0%, respectively, compared with 74.0%, 18.0%, and 8.0% among controls. The overall genotype distribution did not differ significantly between the 2 groups (P = .124). Under the dominant model, no significant association was observed between rs17235409 and TB susceptibility (OR = 0.71, 95% CI: 0.28-1.82; P = .635). Allelic analysis showed that the frequency of the A allele was lower in cases than in controls (10.0% vs 17.0%), but this difference was not statistically significant (OR = 0.54, 95% CI: 0.24-1.25; P = .214). Ethnicity-stratified analyses similarly showed no statistically detectable associations in Miao, Dong, or other groups. The minor allele frequency was 0.095, lower than the Han Chinese reference from 1000 Genomes. In this pilot study of multi-ethnic populations from southwestern China, no statistically significant association was identified between the SLC11A1 rs17235409 polymorphism and tuberculosis susceptibility. Although the A allele appeared less frequent among cases, the limited sample size and statistical power preclude definitive conclusions regarding modest or ethnic-specific effects. These findings provide preliminary genetic data from underrepresented ethnic minority populations and warrant validation in larger multicenter studies.

Adult↗
PubMed2026

Age-related genomic characterization and therapeutic targets in Chinese breast cancer: insights from prospective targeted sequencing and clinical data analysis.

BACKGROUND: In China, breast cancer occurs at a much younger age and has a higher recurrence and mortality rate. However, with changes in lifestyle, there has been a trend towards an older age of breast cancer incidence in Chinese women. There is a paucity of large-scale next-generation sequencing cohorts for the analysis of genomic characterization in these populations and the identification of potential therapeutic targets. METHODS: To address this gap, we performed prospective targeted sequencing of tumor and blood samples from Chinese patients and collected detailed clinical information. We then categorized patients into two groups based on age (<&#x2009;40&#xa0;years, n&#x2009;=&#x2009;637;&#x2009;&#x2265;&#x2009;40&#xa0;years, n&#x2009;=&#x2009;3442) and proceeded to provide comprehensive descriptions of somatic and germline mutations in both groups. RESULTS: The somatic mutation analysis revealed that PIK3CA, FOXA1, and TBX3 mutations were more prevalent in elderly patients. By leveraging the aforementioned mutational characteristics, we employed our institution's FUTURE-SUPER clinical trial, an umbrella study targeting metastatic breast cancer, to confirm the potential benefits of PI3K-AKT-mTOR pathway inhibitors among elderly patients with breast cancer. Furthermore, TP53 and ERBB2 were more likely to be co-mutated in young women. Patients with TP53 and ERBB2 co-mutation tend to have a poorer prognosis, but through investigation of the SPARK cohort, patients carrying the TP53 and ERBB2 co-mutation are more likely to benefit from immune checkpoint inhibitor combination with tyrosine kinase inhibitor therapy. In our study, we observed a higher frequency of mutations in the DNA homology-dependent recombination pathway in young patients with breast cancer, which was associated with an elevated Ki67 index. Additionally, we confirmed a significant prevalence of germline breast cancer susceptibility gene 1 (gBRCA1) mutations in young patients, whereas germline checkpoint kinase 2 (gCHEK2) mutations are more common in elderly patients. CONCLUSIONS: Our study, which makes use of the largest Chinese breast cancer sequencing cohort, sought to characterize the age-related genomic profile of breast cancer patients and identify novel therapeutic opportunities for individuals with breast cancer.

Adult↗
PubMed2026

Twisting the End Game: How Telomere Chromatin Modifications Shape Telomere Maintenance.

Cell division inevitably shortens telomeric DNA owing to the end-replication problem. Eukaryotic chromosomes possess specialized telomere structures to maintain genomic stability. In most proliferative cells, telomerase adds telomeric repeats during S-phase. In differentiated cells where telomerase is silenced, telomeres shorten progressively, thereby compromising genomic integrity. Consequently, cancer cells universally activate alternative telomere maintenance mechanisms during malignant transformation: ~80% reactivate telomerase, while a portion of the rest rely on BIR (break-induced replication)-mediated homologous recombination-based ALT (alternative lengthening of telomeres). Although these mechanisms are stable once established, the initial determinants influencing a cancer cell's choice remain poorly understood. This review discusses recent molecular insights into how telomeric chromatin properties profoundly impact this choice. After briefly introducing telomere chromatin characteristics and key players in its maintenance and dynamics, we discuss the mechanisms by which cancer cells acquire distinct telomere replication capabilities. In particular, we present an in-depth analysis linking telomere heterochromatin status to ALT. Furthermore, based on recent advances, we propose a coupled feedforward loop model explaining how the ALT state becomes "locked in" once initiated. Finally, we offer novel perspectives on rational, telomere-centric therapeutic interventions for ALT-positive cancers, focusing on strategies designed to disrupt such feedforward loops by manipulating telomeric chromatin structure.

Humans↗
PubMed2026

Robotic Needle Insertion for CT-guided Percutaneous Biopsy of Thoracoabdominal Lesions: A Prospective Multicenter Randomized Trial.

Purpose To compare safety and feasibility between a novel CT-guided robotic system and the conventional freehand technique for puncture biopsy of thoracoabdominal lesions. Materials and Methods In this prospective multicenter randomized trial, individuals with suspected lesions were enrolled between July 2023 and April 2024 across three university teaching hospitals and randomized to the robot-assisted group (n = 82) or the freehand group (n = 83). Procedure outcomes included the technical success rate, targeting error, number of CT scans and needle adjustments, puncture time, and complications. Descriptive and inferential statistics were calculated. Results A total of 165 participants (mean age, 60 years &#xb1; 10 [SD]; 83 male) were included. Compared with the freehand group, the robot-assisted group demonstrated a higher technical success rate (97.56% [80 of 82] vs 62.65% [52 of 83], P < .001), lower targeting error (mean Euclidean deviation: 1.7 mm &#xb1; 1.1 vs 4.5 mm &#xb1; 3.9, P < .001), and fewer CT scans (mean, 4.3 &#xb1; 1.9 vs 5.2 &#xb1; 2.3; P = .002) and needle adjustments (mean, 0.7 &#xb1; 0.7 vs 1.6 &#xb1; 1.6; P = .003). Despite differences in geometric precision, both groups achieved 100% (82 of 82 and 83 of 83) diagnostic yield. The median puncture time was comparable between groups (5.5 minutes &#xb1; 4.3 vs 4.8 minutes &#xb1; 7.0, P = .50). During lung biopsies, the robot-assisted approach yielded fewer complications compared with the freehand approach (4.88% [four of 82] vs 16.87% [14 of 83], P = .014). Conclusion Compared with the freehand approach, robot-assisted biopsy yielded greater precision and reduced adjustments and complications while demonstrating noninferior diagnostic efficacy and comparable duration. Keywords: Robotic Needle Insertion, Biopsy, Thoracoabdominal Lesions, Robot-assisted Biopsy, CT-guided Intervention, Percutaneous Needle Biopsy, Randomized Controlled Trial, Algorithm Development, CT, Clinical Testing, Interventional-Body, Biopsy/Needle Aspiration, Percutaneous, Thorax, Abdomen/GI, Liver, Lung, Kidney &#xa9;RSNA, 2026.

Humans↗
PubMed2007

Core-controlled polymorphism in virus-like particles.

This study concerns the self-assembly of virus-like particles (VLPs) composed of an icosahedral virus protein coat encapsulating a functionalized spherical nanoparticle core. The recent development of efficient methods for VLP self-assembly has opened the way to structural studies. Using electron microscopy with image reconstruction, the structures of several VLPs obtained from brome mosaic virus capsid proteins and gold nanoparticles were elucidated. Varying the gold core diameter provides control over the capsid structure. The number of subunits required for a complete capsid increases with the core diameter. The packaging efficiency is a function of the number of capsid protein subunits per gold nanoparticle. VLPs of varying diameters were found to resemble to three classes of viral particles found in cells (T=1, 2, and 3). As a consequence of their regularity, VLPs form three-dimensional crystals under the same conditions as the wild-type virus. The crystals represent a form of metallodielectric material that exhibits optical properties influenced by multipolar plasmonic coupling.

Crystallization↗
PubMed2006

Quasiclassical trajectory calculations of the reaction C+C2H2-->l-C3H, c-C3H+H, C3+H2 using full-dimensional triplet and singlet potential energy surfaces.

Full-dimensional, density functional theory (B3LYP/6-311g(d,p))-based potential energy surfaces (PESs) are reported and used in quasi-classical calculations of the reaction of C with C(2)H(2). For the triplet case, the PES spans the region of the reactants, the complex region (with numerous minima and saddle points) and the products, linear(l)-C(3)H+H, cyclic(c)-C(3)H+H and c-(3)C(3)+H(2). For the singlet case, the PES describes the complex region and products l-C(3)H+H, c-C(3)H+H and l-(1)C(3)+H(2). The PESs are invariant under permutation of like nuclei and are fit to tens of thousands of electronic energies. Energies and harmonic frequencies of the PESs agree well the DFT ones for all stationary points and for the reactant and the products. Dynamics calculations on the triplet PES find both l-C(3)H and c-C(3)H products, with l-C(3)H being dominant at the energies considered. Limited unimolecular reaction dynamics on the singlet PES find both products in comparable amounts as well as the C(3)+H(2) product.

Journal Article↗
PubMed2006

Predicting protein structural class with pseudo-amino acid composition and support vector machine fusion network.

Because a priori knowledge of a protein structural class can provide useful information about its overall structure, the determination of protein structural class is a quite meaningful topic in protein science. However, with the rapid increase in newly found protein sequences entering into databanks, it is both time-consuming and expensive to do so based solely on experimental techniques. Therefore, it is vitally important to develop a computational method for predicting the protein structural class quickly and accurately. To deal with the challenge, this article presents a dual-layer support vector machine (SVM) fusion network that is featured by using a different pseudo-amino acid composition (PseAA). The PseAA here contains much information that is related to the sequence order of a protein and the distribution of the hydrophobic amino acids along its chain. As a showcase, the rigorous jackknife cross-validation test was performed on the two benchmark data sets constructed by Zhou. A significant enhancement in success rates was observed, indicating that the current approach may serve as a powerful complementary tool to other existing methods in this area.

Algorithms↗
PubMed2006

Using pseudo-amino acid composition and support vector machine to predict protein structural class.

As a result of genome and other sequencing projects, the gap between the number of known protein sequences and the number of known protein structural classes is widening rapidly. In order to narrow this gap, it is vitally important to develop a computational prediction method for fast and accurately determining the protein structural class. In this paper, a novel predictor is developed for predicting protein structural class. It is featured by employing a support vector machine learning system and using a different pseudo-amino acid composition (PseAA), which was introduced to, to some extent, take into account the sequence-order effects to represent protein samples. As a demonstration, the jackknife cross-validation test was performed on a working dataset that contains 204 non-homologous proteins. The predicted results are very encouraging, indicating that the current predictor featured with the PseAA may play an important complementary role to the elegant covariant discriminant predictor and other existing algorithms.

Amino Acid Sequence↗
PubMed2006

Statistical morphological skull stripping of adult and infant MRI data.

This paper describes a novel automatic statistical morphology skull stripper (SMSS) that uniquely exploits a statistical self-similarity measure and a 2-D brain mask to delineate the brain. The result of applying SMSS to 20 MRI data set volumes, including scans of both adult and infant subjects is also described. Quantitative performance assessment was undertaken with the use of brain masks provided by a brain segmentation expert. The performance is compared with an alternative technique known as brain extraction tool. The results suggest that SMSS is capable of skull-stripping neurological data with small amounts of over- and under-segmentation.

Adult↗
PubMed2006

Low ligand loading, highly enantioselective addition of phenylacetylene to aromatic ketones catalyzed by Schiff-base amino alcohols.

[reaction: see text] Schiff-base amino alcohols 7a,b derived from L-phenylglycine through three simple steps are found to be highly effective for the enantioselective addition of phenylacetylene to aromatic ketones. When the loading of 7b was 1 mol %, an ee value of up to 95% was obtained. However, when 7b was lowered to 0.1 mol %, a high ee value of 85% was still achieved. A practical solution to synthesize the optically active tertiary propargylic alcohols was described.

Journal Article↗
PubMed2006

Association between a functional COMT polymorphism, mental retardation and cognition in Qinba area children.

Catechol-O-methyl transferase (COMT) plays an important role in the metabolism of neurotransmitters. Two alleles of the COMT gene as a result of a G/A transition in the exon 4 can lead to different COMT enzymatic activities. Much genetic research has revealed that this COMT functional polymorphism was related to human psychiatric disorders. Polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) methods were used to discern the relationships among the functional polymorphism of COMT, mental retardation (MR), and general cognitive ability of children. The results of the case-control analysis showed that there was no association between the frequencies of genotypes of COMT and MR (chi2=0.776, P>0.05) or between the frequency of COMT alleles and MR (chi2=0.335, P>0.05). COMT polymorphism was found in children whose intelligence quotient (IQ) was above 55. In normal children (IQ> or =85), the frequencies of high-activity allele COMTH and the homozygote genotype COMTHH were 60.98% and 79.28%, respectively. Both were higher than those of the borderline group (46.67% and 70.67%, 0.10 > P>0.05). Therefore, the result of this study suggests that this functional polymorphism is not an important risk factor for MR, but the COMTHH genotype may have a positive effect on cognitive performance in normal children in the Qinba area.

Adolescent↗
PubMed2006

Nanoparticle-templated assembly of viral protein cages.

Self-assembly of regular protein surfaces around nanoparticle templates provides a new class of hybrid biomaterials with potential applications in medical imaging and in bioanalytical sensing. We report here the first example of efficiently self-assembled virus-like particles (VLPs) having a brome mosaic virus protein coat and a functionalized gold core. The present study indicates that functionalized gold particles can initiate VLP assembly by mimicking the electrostatic behavior of the nucleic acid component of the native virus. These VLP constructs are symmetric, with the protein stoichiometry and packaging properties indicating similarity to the icosahedral packing of the capsid. Moreover, a pH-induced swelling transition of the VLPs is observed, in direct analogy to the native virus.

Biomimetic Materials↗
PubMed2006

[Distribution of STR locus DXS8027 polymorphism in the Han population in Qinba mountain areas].

To investigate the genetic polymorphism at DXS8027 STR locus for Han population in Qinba Mountain Areas and construct a preliminary population genetics database for this locus. We collected 550 venous blood samples from unrelated Han individuals of the Qinba Mountain Areas, Blood was treated with anticoagulant EDTA, and genomic DNA was obtained by phenol-chloroform extraction. Target fragments for the DXS8027 were amplified by PCR, separated on 8% non-denaturing polyacrylamide gel. electrophoresis and stained with 0.1% silver nitrate (AgNO3). Nine alleles were observed among the total samples, and the allele frequencies were in accordance with Hardy-Weinberg equilibrium (P>0.05) with relatively high heterozygosity (Het=0.7968). The results showed that there was a significant difference in the distribution of DXS8027 allele frequency between males and females (Chi 2=30.242, P<0.01), but the difference was not significant in the same gender groups of the two areas (Chi 2=4.703, P >0.05; Chi 2=14.952, P >0.05), or between the two areas regardless of gender (Chi 2=15.2, P >0.05). There was a very significant difference in DXS8027 allele frequency in populations of the Qinba Mountain Areas and the European populations, (Chi 2=37.572, P<0.01). It provides database to further study this STR locus in different population.

Asian People↗
PubMed2006

[Simultaneous control of microorganism, disinfection by-products and bio-stability by sequential chlorination disinfection].

A new safe chlorination disinfection process, the sequential disinfection process with short-term free chlorine plus chloramines was investigated its efficiency on control of indices of microorganism, disinfection by-products and bio-stability. This disinfection process may take the advantage of free chlorine's quick inactivation of microorganism and chloramines' low DBP yield and long-term residual. Thus, both control of microorganisms and DBPs can be achieved effectively and economically. The pilot test results show that safe chlorination disinfection process has a little better efficiency on total bacteria count, HPC and total coliform count than free chlorination disinfection, which indicate that free chlorine and chloramines might have the synergetic disinfection effect for their different attacking targets. It also had the same inactivation efficiency on polio virus and coliphage f2 as free chlorination in 120 minutes contact time. Sequential chlorination disinfection process could reduce 35.8% - 77.0% yield of trihalomethane and 36.6% - 54.8% yield of haloacetic acids. The poorer quality the water had, the more advantage the safe-chlorination disinfection had than free chlorination disinfection one. Moreover, sequential chlorination had better efficiency on bio-stability control than free chlorination.

Chloramines↗
PubMed2006

[Effects of different oxygen inhalation modes on retinal vessels development in neonatal mice].

OBJECTIVE: This study was designed to investigate the effects of different oxygen inhalation modes on retinal vessels development in neonatal mice in order to provide experimental data for proper oxygen therapy for premature infants. METHODS: A total of 144 postnatal day (P) 7 C57BL/6J mice were randomly assigned into 6 groups according to different oxygen inhalation modes (n=24). Experimental group 1 was exposed to 30%, 40%, 50%, 60% and 75% oxygen in turn for one day respectively, followed by room air exposure for 5 days. Experimental group 2 was exposed to 75%, 60%, 50%, 40% and 30% oxygen in turn for one day respectively, followed by room air exposure for 5 days. Experimental group 3 was exposed to 75% oxygen for 5 days, followed by room air exposure for 5 days. Experimental group 4 was exposed to 75% oxygen for 5 days, 50% oxygen for 2 days and 30% oxygen for 2 days, then room air exposure for 6 days. The supplemental 75% oxygen and room air recovering was performed alternately for the mice in Experimental group 5 for 3 times and then room air exposure for 5 days. The Control group was exposed to room air for consecutive 10 days. The retinal vascular development and proliferation were evaluated by the retinal flat-mounts (ADPase stained retina) and cross-section. RESULTS: The peripheral vascular pattern was clear, and a few avascular areas were seen in the Control group at P12. At P14 the avascular area disappeared. At P17, the entire vascular pattern became completely normal. In the Experimental groups 1, 3 and 5, the central vessels became tortuous and constricted and the central avascular area increased at P12. At P14, neovascularization was seen peaking at P17 in the Experimental groups 1, 3 and 5. In the Experimental group 4, the central avascular area increased and neovascularization was seen at P14, but the central avascular area was reduced and abnormal neovascularization disappeared, with slight constriction of the deep vessels, at P17. Five days later the vascular pattern became almost normal in the Experimental group 4. The retinal vascular form of the Experimental group 2 was similar to that of the Control group. The average number of neovascular nuclei extending into the vitreous per cross-section in the Experimental groups 1, 2, 3, 4, and 5 and the Control group was 49.50 +/- 1.36, 5.17 +/- 0.67, 47.68 +/- 4.70, 5.74 +/- 2.37, 29.15 +/- 2.48, and 1.22 +/- 0.20 respectively. There were significant differences between the Experimental groups 1, 3, 5 and the Control group (P < 0.05). CONCLUSIONS: The effects of different oxygen inhalation modes on the retinal vessels development in neonatal mice were different. The obvious fluctuation of inhaled oxygen concentration and abrupt stop of supplemental oxygen after high levels of supplemental oxygen may severely affect the development of retina vascular, leading to the pathologic changes similar to retinopathy of prematurity.

Animals↗
PubMed2006

[Study on the esophageal cancer incidence and mortality rate from 1974-2002 in Cixian, China].

OBJECTIVE: To describe the incidence and mortality rates of esophageal cancer from 1974-2002 in Cixian county of Hebei province. Basic information on comparative geographical, epidemiological, and clinical research was collected. METHODS: In early 1970s, cancer registry system in Cixian was established, collecting information on all the esophageal cancer cases in Cixian. Data was checked manually, then computerized, coded and analyzed using the software--SPSS 11.5. RESULTS: From 1974 to 2002, there were 18 471 esophageal cancer cases in Cixian, with 11 068 males and 7403 females, respectively. The age standardized incidence rate (ASR) for males was 208.77 per 100,000, while 120.47 per 100,000 for females. The trend of incidence rate of esophageal cancer had decreased during the 29 years from 1974 to 2002 (trend chi(2) = 19.94, P < 0.001). From 25 years of age onward, the incidence rates of the lower age groups declined with the increase of age. As for geographic distribution, the incidence rate in mountainous areas and hilly areas showed a significant declining trend in mountainous areas, chi(2) = 195.00, P < 0.001; hilly areas, chi(2) = 46.08, P < 0.001. The esophageal cancer incidence in plain areas remained steady, but had a slight increase in recent years. From 1969 to 2002, there were 18,736 cases died of esophageal cancer with 11 598 males and 7138 females. The ASR for male was 127.17 per 100,000 and 101.57 per 100,000 for female. Compared with the year 1969, the mortality rate of esophageal cancer in 2002 had a 37.96% decline. The proportion of esophageal cancer among malignant tumors in different decades decreased significantly. CONCLUSION: The trend of the incidence rate of esophageal cancer had been decreasing for the last 29 years. The incidence rate in mountainous areas and hilly areas showed a declining trend while in the plain areas it remained steady but having slight increase in the recent years. The mortality rate of esophageal cancer had a significant decrease from 1969 to 2002.

Adult↗