Biomedical subjects

Xiaohong Duan

Publications and source records attributed to Xiaohong Duan.

5 recordsLinked to original sources

PubMed2026

Dental phenotypes associated with novel PHEX variants in X-linked hypophosphatemia.

OBJECTIVES: X-linked hypophosphatemia (XLH) is a genetic disorder related to bone, mainly due to the mutations in PHEX gene. Previous studies have reported that XLH patients had various tooth phenotypes. It is unclear whether there are any rules about these abnormal tooth phenotypes, especially in those XLH cases with PHEX mutations. The objectives of this study were to find the most representative dental characteristics of XLH and the possible phenotype-genotype correlation. DESIGN: Two unrelated patients with XLH underwent clinical, radiographic, biochemical, and genetic evaluation. Whole-exome sequencing and whole-genome sequencing were used to identify pathogenic variants. The ultrastructure of extracted teeth was analyzed using a stereomicroscope, micro-CT, and scanning electron microscopy. In addition, a PubMed search (up to January 2026) identified 22 articles involving 366 patients for descriptive phenotype comparison. RESULTS: Two novel PHEX variants were identified: a novel complex structural variant (NC_000023.11, g.22035649-22041668delins) and a novel heterozygous splice-site variant (NM_000444.6, c.850-1 G>A). Radiographic examination showed enlarged pulp chambers and irregular pulp morphology. Ultrastructural analysis revealed dentin defects, including globular dentin, irregular interglobular dentin, disrupted dentinal tubules, and exposed collagen fibrils. Literature-based analysis indicated prevalent clinical manifestations (pulp necrosis, tooth loss, periodontitis) and radiographic findings (enlarged pulp chamber, and prominent pulp horn). CONCLUSION: In these two patients, novel PHEX variants were associated with a recurrent dentin-pulp phenotype. Integrated clinical, radiographic, ultrastructural, and literature evidence supports dentin defects as a central component of the dental phenotype in XLH and underscores the importance of early dental assessment.

Humans↗

PubMed2005

[A hydrostatic compression device capable of generating both intermittent compressive forces and continuous compressive forces].

A hydrostatic compression device has been designed to study the effects of intermittent or continuous compressive forces on cells by trying to mimic in vivo forces. The model system is composed of two pistons that deliver and release compressed air under control of a motor to form an enclosed tissue culture chamber housing numerous tissues culture dishes. The continuous compressive forces and intermittent compressive forces are within 100-300 KPa and 0-30 KPa respectively. The compressive force is uniform in the system and can also result in the generation of shear forces along the interface between the cells and culture substratum, so the hydrostatic compression device can be used to study the characteristics of in vitro cells loading models.

Biomechanical Phenomena↗

PubMed2004

Manganese-enhanced magnetic resonance imaging (MEMRI) of mouse brain development.

Given the importance of genetically modified mice in studies of mammalian brain development and human congenital brain diseases, MRI has the potential to provide an efficient in vivo approach for analyzing mutant phenotypes in the early postnatal mouse brain. The combination of reduced tissue contrast at the high magnetic fields required for mice, and the changing cellular composition of the developing mouse brain make it difficult to optimize MRI contrast in neonatal mouse imaging. We have explored an easily implemented approach for contrast-enhanced imaging, using systemically administered manganese (Mn) to reveal fine anatomical detail in T1-weighted MR images of neonatal mouse brains. In particular, we demonstrate the utility of this Mn-enhanced MRI (MEMRI) method for analyzing early postnatal patterning of the mouse cerebellum. Through comparisons with matched histological sections, we further show that MEMRI enhancement correlates qualitatively with granule cell density in the developing cerebellum, suggesting that the cerebellar enhancement is due to uptake of Mn in the granule neurons. Finally, variable cerebellar defects in mice with a conditional mutation in the Gbx2 gene were analyzed with MEMRI to demonstrate the utility of this method for mutant mouse phenotyping. Taken together, our results indicate that MEMRI provides an efficient and powerful in vivo method for analyzing neonatal brain development in normal and genetically engineered mice.

Aging↗

PubMed2002

[Microencapsulation of immortalized mandibular condylar chondrocytes].

To explore the possibility of microencapsulation of chondrocytes in cartilage tissue engineering, immortalized manibular condylar chondrocytes (IMCCs) were microencapsuled by Alginate-polylysine-alginate (APA) method, according to air pressure shearing model. Phase contrast microscopy, trypan blue staining exclusion, cell number counting, HE staining and immunohistochemistry method were used to observe the morphology of the microencapsules, the growth character of cells, cartilage characteristics, and so on. The results showed that IMCC could survive and grow in microencapsule, and the viability rate of cells is more than 80 per cent. The diameter of microcapsule is 779 microns in average. The number of cell increased with time, and cells went into platform in about 20 days. Cells grew in clusters and cartilage specific proteoglycans and type II collagen were highly expressed. It was concluded that IMCC could form cartilage-like tissue within microencapsulation, implying that microencapsule technique might be applicable to cartilage tissue engineering.

Alginates↗

PubMed2002

[A study on the morphological characters of immortalized mandibular condylar chondrocyte].

OBJECTIVE: The purpose of this study was to compare the morphological character between immortalized mandibular condylar chondrocyte (IMCC) and primarily cultured mandibular condylar chondrocyte (MCC). METHODS: The phase contrast microscope, photomicroscope and transmission electron microscope were used to observe the morphological character of IMCC and MCC. The highresolution pathological image and word report system-1000 (HPIAS-1000) was used to compare the size of IMCC and MCC. RESULTS: The phase contrast micrography showed that MCCs in primary culture underwent distinct morphological changes with respect to shape, size, and density of the cells. The majority of MCCs were in polygonal shape earlier in culture, while more fusi-form and spindle-shaped cells were found after 4-5 passages. While IMCCs were polygonal-shaped, similar to MCCs. Subculture, freezing and recovering had no effect on cellular shape of IMCC. Transmission electron microscopy indicated that MCC had chondrocyte-like phenotype, while IMCC looked like prechondroblast or immature chondrocyte. Some of IMCCs had irregular nucleus, and the proportion of nucleus/cytoplasm changed. By analysis of HPIAS-1000, the diameter and area of IMCC were obvious smaller than those of MCC (P < 0.01). CONCLUSION: IMCC retain the main morphological character of MCC, and also keep a stable phenotype, which belong to immature chondrocytes, similar to cells in the proliferative zone.

Animals↗