Bone regeneration with hydroxyapatite particles loaded in photo-cross-linkable hydrogel: An experimental study.

This study explores the use of in situ cross-linked hyaluronic acid methacryloyl (HAMA) and hydroxyapatite particles (HAP) for bone defect repair. Human periodontal ligament stem cells (PDLSCs) were isolated and co-cultured with the HAMA-HAP composite. Osteogenic differentiation was evaluated using Alizarin Red staining, alkaline phosphatase activity quantification, and polymerase chain reaction (PCR). A cranial defect was induced in Sprague-Dawley rats. This defect was then filled with the HAMA-HAP composite and cross-linked using UV light exposure. Bone formation was assessed through radiographic and histological analyses. The HAMA-HAP composite was found to promote cell viability similarly to pure HAP. It also enhanced gene expression of ALP, OPN, and Runx2, and increased ALP activity and mineralized nodule formation in vitro. Micro-CT scans showed defect restoration in the HAMA-HAP and HAP groups compared to the control group. The HAMA-HAP group exhibited higher Tb.N, Tb.Sp, Tb.Th, and BV/TV. Masson staining showed the HAMA-HAP composite restored the defect site, with new bone formation thicker than in the HAP group. The HAMA-HAP composite showed excellent biocompatibility and promoted osteogenic differentiation of PDLSCs. It effectively repaired cranial defects, indicating its potential for clinical use in bone defect repair.

Video game addiction in psychiatric adolescent population: A hospital-based study on the role of individualism from South China.

BACKGROUND: For decades, video game-related behaviors have been investigated in different psychologic research, much of whose attention has been paid to video game addiction (VGA), while the differences between VGA and social media addiction (SMA) should have deserved more attention. In addition to detecting common risk factors of VGA, one core question is whether social inclination (individualism or collectivism) matters. OBJECT: The objectives of this study were to clarify the prevalence of VGA and SMA,, identify the influencing factors of VGA, and clarify the relationships between VGA and adolescents' individualism-collectivism inclination. METHOD: The survey was conducted among 110 adolescent psychiatric patients. For each interviewee, psychological scales were filled face to face. Path analysis was used to examine the causation structure of the childhood trauma-related symptoms. RESULT: The prevalence of VGA was 40.9% (45 out of 110), and it was 41.8% for SMA (46 out of 110); childhood trauma, social media addiction, the individualistic inclination, and the rate of homosexuality were observed to be independent indicators for video game addiction (r2  = 0.46). CONCLUSION: Psychological counseling on patients' internet-related behaviors may focus on the individualistic personality and possible childhood trauma, which are two important risk factors of video game addiction. It is recommended to distinguish between video game addiction and social addiction in clinical practice.

Bi-allelic BRWD1 variants cause male infertility with asthenoteratozoospermia and likely primary ciliary dyskinesia.

Genetics-associated asthenoteratozoospermia is often seen in patients with multiple morphological abnormalities of the sperm flagella (MMAF). Although 24 causative genes have been identified, these explain only approximately half of patients with MMAF. Since sperm flagella and motile cilia (especially respiratory cilia) have similar axonemal structures, many patients with MMAF also exhibit respiratory symptoms, such as recurrent airway infection, chronic sinusitis, and bronchiectasis, which are frequently associated with primary ciliary dyskinesia (PCD), another recessive disorder. Here, exome sequencing was conducted to evaluate the genetic cause in 53 patients with MMAF and classic PCD/PCD-like symptoms. Two homozygous missense variants and a compound-heterozygous variant in the BRWD1 gene were identified in three unrelated individuals. BRWD1 staining was detected in the whole flagella and respiratory cilia of normal controls but was absent in BRWD1-mutated individuals. Transmission electron microscopy and immunostaining demonstrated that BRWD1 deficiency in human affected respiratory cilia and sperm flagella differently, as the absence of outer and inner dynein arms in sperm flagellum and respiratory cilia, while with a decreased number and outer doublet microtubule defects of respiratory cilia. To our knowledge, this is the first report of a BRWD1-variant-related disease in humans, manifesting as an autosomal recessive form of MMAF and PCD/PCD-like symptoms. Our data provide a basis for further exploring the molecular mechanism of BRWD1 gene during spermatogenesis and ciliogenesis.

Hydroxyapatite-incorporation improves bone formation on endosseous PEEK implant in canine tibia.

BACKGROUND: Poly Ether Ether Ketone (PEEK) has been considered as a potential alternative material for endosseous dental implants, for its low elastic modulus, biocompatibility, and low cost in customized device manufacture. Hydroxyapatite-incorporation is supposed to improve the poor osseointegration of PEEK. METHODS: In the present study we analyzed the in vivo response of hydroxyapatite-incorporated PEEK (PEEK-HA) implants in canine tibia. PEEK-HA and PEEK implants were implanted and were examined 4 weeks and 12 weeks after implantation with radiology and histology. Commercial titanium dental implants served as controls. RESULTS: The ratio of bone volume to tissue volume of PEEK-HA implants was higher than that of PEEK implants 4 weeks after implantation in the µ-CT analysis. The bone implant contact of PEEK and PEEK-HA implants showed no statistical difference in the histological examination, but newly-formed bone around PEEK-HA implants showed more signs of mineralization than that around PEEK implants. CONCLUSION: The study suggested that bone formation was improved with hydroxyapatite-incorporation in PEEK. Hydroxyapatite-incorporated PEEK implants may represent a potential material for endosseous dental implant.

LAPTM5 is transactivated by RUNX2 and involved in RANKL trafficking in osteoblastic cells.

The present study aimed to investigate the role of lysosomal­associated transmembrane protein 5 (LAPTM5) in osteoclast differentiation induced by osteoblasts. The results demonstrated that the expression levels of LAPTM5 were downregulated following runt­related transcription factor 2 (RUNX2) silencing and upregulated following RUNX2 overexpression in ST2 cells. Chromatin immunoprecipitation analysis identified the binding of RUNX2 to the LAPTM5 promoter at the ­1176 to ­1171 position. Dual­luciferase reporter assays confirmed that RUNX2 directly activated the LAPTM5 gene. The concentration of receptor activator of nuclear factor­κB ligand (RANKL) protein in the cytoplasm and in the media was significantly increased following LAPTM5 knockdown. LAPTM5 silencing in ST2 cells enhanced osteoclastic differentiation of co­cultured RAW264.7 cells. The present study indicated that expression of LAPTM5 was regulated by the interaction of RUNX2 with its promoter region and that LAPTM5 was involved in the trafficking of RANKL. These findings suggested a possible coupling mechanism between osteogenesis and osteoclastogenesis in which RUNX2 may be involved in osteoclast differentiation through the regulation of the lysosome­associated genes that modulate RANKL expression.

Magnitude-dependent response of osteoblasts regulated by compressive stress.

The present study aimed to investigate the role of magnitude in adaptive response of osteoblasts exposed to compressive stress. Murine primary osteoblasts and MC3T3-E1 cells were exposed to compressive stress (0, 1, 2, 3, 4, and 5 g/cm2) in 3D culture. Cell viability was evaluated, and expression levels of Runx2, Alp, Ocn, Rankl, and Opg were examined. ALP activity in osteoblasts and TRAP activity in RAW264.7 cells co-cultured with MC3T3-E1 cells were assayed. Results showed that compressive stress within 5.0 g/cm2 did not influence cell viability. Both osteoblastic and osteoblast-regulated osteoclastic differentiation were enhanced at 2 g/cm2. An increase in stress above 2 g/cm2 did not enhance osteoblastic differentiation further but significantly inhibited osteoblast-regualted osteoclastic differentiation. This study suggested that compressive stress regulates osteoblastic and osteoclastic differentiation through osteoblasts in a magnitude-dependent manner.

The blocking effect and abrasion resistance of hydroxyapatite with different particle sizes and morphologies for dentinal tubules / 口腔疾病防治

Objective@#To study the blocking effect and abrasion resistance of hydroxyapatite (HA) with different particle sizes and morphologyies on dentinal tubules from the qualitative and quantitative aspects. @*Methods @# Dentin discs were etched and divided into 4 groups randomly: 20 nm HA group; 30 nm HA group; 12 μm HA group; control group (without any experimental treatment). Each group was brushed with correspondent materials for 7 days. Then, the dentin disk was divided into two parts, the one was detected by the scanning electron microscopy (SEM); the other was observed by SEM after toothbrush abrasion test. The Image-Pro Plus 6.0 image analysis software was used to calculate the plugging rate of dentinal tubules. @*Results @#SEM showed that the blockage is granular, the plugging rate of the dentinal tubules were about 82% to 96%. 30 nm HA group (short rod) range the first in the average plugging rate, followed by the 20 nm HA group (needles) and 12 μm HA group (spherical). After mechanical brushing for 7 days, SEM images showed that deposited layer in each group was smooth and compact, and more than 63% of the tubules still had been blocked. @* Conclusion @#HA with different particle sizes and morphologies had good plugging effect and abrasion resistance on dentine tubules. The blocking effect of HA was affected not only by particle size but also by the morphology.

[Impact of particle size and morphology on zinc cation adsorption by hydroxyapatite and dentifrice containing hydroxyapatite].

OBJECTIVE: To study the influence of particle size and morphology on zinc cation adsorption by hydroxyapatite (HA) and dentifrice containing HA. METHODS: Four HAs with different particle sizes and morphologies, HA-containing dentifrice and blank dentifrice were prepared into suspensions of serial concentrations. Zinc ion solutions with an initial concentration of 10 mg/L was mixed with the suspensions and kept for 24 h for adsorption reaction. The zinc ion concentration in the supernatant was measured by inductively coupled plasma emission spectrometer and the sorption rate of zinc ion was calculated. RESULTS: HA and HA-containing dentifrice with various particle sizes and morphologies were all capable of absorbing zinc ions from simulated waste water, and the adsorption rate of HA-containing dentifrice was 3%-10% higher than that of HA. HA with a particle size of 12 µm and a spherical morphology showed the strongest adsorption ability, followed by short bar-shaped HA with a particle size of 30 µm. Both Langmuir and Freundlich equation could simulate the sorption processes of HA dentifrice, while only Langmuir equation could simulate the sorption processes of HA. CONCLUSION: Incorporation of HA in dentifrice can enhance zinc ion adsorption capacity of the material. The particle size and morphology of HA both affect the adsorption of zinc ions, and 12-µm HA particle with a spherical morphology has the best adsorption ability.

[Genetic diagnosis for a Chinese Han family with hereditary multiple osteochondromas].

OBJECTIVE: To identify the genetic cause for a Chinese Han family affected with hereditary multiple osteochondromas. METHODS: Two patients, five unaffected relatives of the family and 100 unrelated healthy controls were collected. The coding sequences and intron/exon boundaries of EXT1 gene were amplified with polymerase chain reaction (PCR) and sequenced. RESULTS: A heterozygous c.600G>A (p.Trp200X) mutation in exon 1 of the EXT1 gene was detected in the patients. The same mutation was not found in unaffected family members and 100 healthy controls. CONCLUSION: The hereditary multiple osteochondromas in the family is caused by a nonsense mutation (p.Trp200X) in the EXT1 gene.

Isolation, expression, and characterization of a hydroperoxide lyase gene from cucumber.

A full-length cDNA coding for hydroperoxide lyase (CsHPL) was isolated from cucumber fruits of No. 26 (Southern China type) and No.14-1 (Northern China type), which differed significantly in fruit flavor. The deduced amino acid sequences of CsHPL from both lines show the same and significant similarity to known plant HPLs and contain typical conserved domains of HPLs. The recombinant CsHPL was confirmed to have 9/13-HPL enzymatic activity. Gene expression levels of CsHPL were measured in different organs, especially in fruits of different development stages of both lines. The HPL activities of fruit were identified basing on the catalytic action of crude enzyme extracts incubating with 13-HPOD (13-hydroperoxy-(9Z,12E)-octadecadienoic acid) and 13-HPOD + 9-HPOD (9-hydroperoxy-(10E,12Z)-octadecadienoic acid), and volatile reaction products were analyzed by GC-MS (gas chromatography-mass spectrometry). CsHPL gene expression in No. 26 fruit occurred earlier than that of total HPL enzyme activity and 13-HPL enzyme activity, and that in No. 14-1 fruit was consistent with total HPL enzyme activity and 9-HPL enzyme activity. 13-HPL enzyme activities decreased significantly and the 9-HPL enzyme activities increased significantly with fruit ripening in both lines, which accounted for the higher content of C6 aldehydes at 0-6 day post-anthesis (dpa) and higher content of C9 aldehydes at 9-12 dpa.

Recombinant adenovirus with human indoleamine-2,3-dioxygenase and hepatitis B virus preS was constructed and expressed in HepG2 cells.

BACKGROUND: Indoleamine-2,3-dioxygenase (IDO) is proven to suppress hepatitis B virus (HBV) specific immune response and depletion of IDO may be a useful approach for HBV therapy. To test this concept, we constructed recombinant adenovirus with human IDO and HBV preS, which would form the basis for future in vivo experiments. METHODS: The fragment of human IDO and HBV preS cDNA were subcloned into multiple cloning sites in an adenoviral vector system containing two cytomegalovirus (CMV) promoters. Recombination was conducted in the Escherichia coli BJ5183. The recombinant adenovirus containing hIDO gene and HBVpreS gene was packaged and amplified in 293 cells. Integration was confirmed by polymerase chain reaction as well as the quantification of viral titers. HepG2 cells were infected with the recombinant adenovirus and mRNA and protein specific for hIDO and HBVpreS was detected by RT-PCR and Western blotting respectively. RESULTS: The recombinant adenovirus was produced successfully. Its titer was 2.5 × 10(9) efu/ml. IDO and HBVpreS mRNA as well as the encoded proteins could be found in transfected HepG2 cells, but not in control HepG2 cells. CONCLUSION: The transfer of hIDO-HBVpreS with double-promoter adenoviral vector was efficient. The recombinant adenovirus with hIDO and HBV preS would provide the experimental basis for future studies.

[Analysis of risk factors for cerebral infarction after hip arthroplasty].

OBJECTIVE: To investigate the independent risk factors for cerebral infarction so as to provide a theoretical basis for the prevention of cerebral infarction after total hip arthroplasty. METHODS: A retrospective analysis of 571 patients for hip arthroplasty was conducted from January 2003 to September 2008. Twenty-three patients were found with cerebral infarction postoperatively. Single-factor and multi-factor correlation analyses were tested for the patients with cerebral infarction after hip arthroplasty. RESULTS: The single-factor analysis for hip arthroplasty revealed that age (P = 0.001) and femoral neck fracture (P = 0.008) were the main factors for cerebral infarction. Furthermore, age was considered a risk factor for cerebral infarction after hip arthroplasty in multi-factor analysis (P = 0.029, OR = 1.054, 95%CI: 1.005 - 1.105). CONCLUSION: Advanced age (> 70 yr) and femoral neck fracture are the main independent risk factors for cerebral infarction after hip arthroplasty.