Research Progress on the Experimental Model and Underlying Mechanistic Studies of Tension-Type Headaches.

PURPOSE OF REVIEW: Tension-type headaches (TTH) significantly diminish patients' quality of life and increase absenteeism, thereby imposing a substantial economic burden. Animal models are essential tools for studying disease mechanisms and drug development. However, until now, little focus has been placed on summarizing the animal models of TTH and associated mechanistic studies. This narrative review discusses the current animal models of TTH and related mechanistic studies to provide insights into the pathophysiological mechanisms of and treatments for TTH. RECENT FINDINGS: The primary method for constructing an animal model of TTH involves injecting a solution of pain relievers, such as adenosine triphosphate, nerve growth factor, or a high concentration of salt solution, into the neck to initiate harmful cervical muscle responses. This model enables the examination of the interaction between peripheral muscles and central sensitization, which is crucial for understanding the pathophysiology of TTH. Mechanistic studies based on this model have investigated the effect of the P2X receptor antagonist, P2X7 receptor blockade, the P2Y1 receptor agonist 2-MESADP, P2Y1 receptor antagonist MRS2179, nitric oxide synthase inhibitors, and acetylsalicylic acid. Despite notable advancements, the current model of TTH has limitations, including surgical complexity and the inability to replicate chronic tension-type headache (CTTH). To gain a more comprehensive understanding and develop more effective treatment methods, future studies should focus on simplifying surgical procedures, examining other predisposing factors, and establishing a model for chronic TTH. This will offer a deeper insight into the pathophysiological mechanism of TTH and pave the way for improved treatment approaches.

IRE1α regulates macrophage polarization, PD-L1 expression, and tumor survival.

In the tumor microenvironment, local immune dysregulation is driven in part by macrophages and dendritic cells that are polarized to a mixed proinflammatory/immune-suppressive phenotype. The unfolded protein response (UPR) is emerging as the possible origin of these events. Here we report that the inositol-requiring enzyme 1 (IRE1α) branch of the UPR is directly involved in the polarization of macrophages in vitro and in vivo, including the up-regulation of interleukin 6 (IL-6), IL-23, Arginase1, as well as surface expression of CD86 and programmed death ligand 1 (PD-L1). Macrophages in which the IRE1α/X-box binding protein 1 (Xbp1) axis is blocked pharmacologically or deleted genetically have significantly reduced polarization and CD86 and PD-L1 expression, which was induced independent of IFNγ signaling, suggesting a novel mechanism in PD-L1 regulation in macrophages. Mice with IRE1α- but not Xbp1-deficient macrophages showed greater survival than controls when implanted with B16.F10 melanoma cells. Remarkably, we found a significant association between the IRE1α gene signature and CD274 gene expression in tumor-infiltrating macrophages in humans. RNA sequencing (RNASeq) analysis showed that bone marrow-derived macrophages with IRE1α deletion lose the integrity of the gene connectivity characteristic of regulated IRE1α-dependent decay (RIDD) and the ability to activate CD274 gene expression. Thus, the IRE1α/Xbp1 axis drives the polarization of macrophages in the tumor microenvironment initiating a complex immune dysregulation leading to failure of local immune surveillance.

The unfolded protein response links tumor aneuploidy to local immune dysregulation.

Aneuploidy is a chromosomal abnormality associated with poor prognosis in many cancer types. Here, we tested the hypothesis that the unfolded protein response (UPR) mechanistically links aneuploidy and local immune dysregulation. Using a single somatic copy number alteration (SCNA) score inclusive of whole-chromosome, chromosome arm, and focal alterations in a pan-cancer analysis of 9,375 samples in The Cancer Genome Atlas (TCGA) database, we found an inverse correlation with a cytotoxicity (CYT) score across disease stages. Co-expression patterns of UPR genes changed substantially between SCNAlow and SCNAhigh groups. Pathway activity scores showed increased activity of multiple branches of the UPR in response to aneuploidy. The PERK branch showed the strongest association with a reduced CYT score. The conditioned medium of aneuploid cells transmitted XBP1 splicing and caused IL-6 and arginase 1 transcription in receiver bone marrow-derived macrophages and markedly diminished the production of IFN-γ and granzyme B in activated human T cells. We propose the UPR as a mechanistic link between aneuploidy and immune dysregulation in the tumor microenvironment.

Evaluating construct validity of computable acute respiratory distress syndrome definitions in adults hospitalized with COVID-19: an electronic health records based approach.

BACKGROUND: Evolving ARDS epidemiology and management during COVID-19 have prompted calls to reexamine the construct validity of Berlin criteria, which have been rarely evaluated in real-world data. We developed a Berlin ARDS definition (EHR-Berlin) computable in electronic health records (EHR) to (1) assess its construct validity, and (2) assess how expanding its criteria affected validity. METHODS: We performed a retrospective cohort study at two tertiary care hospitals with one EHR, among adults hospitalized with COVID-19 February 2020-March 2021. We assessed five candidate definitions for ARDS: the EHR-Berlin definition modeled on Berlin criteria, and four alternatives informed by recent proposals to expand criteria and include patients on high-flow oxygen (EHR-Alternative 1), relax imaging criteria (EHR-Alternatives 2-3), and extend timing windows (EHR-Alternative 4). We evaluated two aspects of construct validity for the EHR-Berlin definition: (1) criterion validity: agreement with manual ARDS classification by experts, available in 175 patients; (2) predictive validity: relationships with hospital mortality, assessed by Pearson r and by area under the receiver operating curve (AUROC). We assessed predictive validity and timing of identification of EHR-Berlin definition compared to alternative definitions. RESULTS: Among 765 patients, mean (SD) age was 57 (18) years and 471 (62%) were male. The EHR-Berlin definition classified 171 (22%) patients as ARDS, which had high agreement with manual classification (kappa 0.85), and was associated with mortality (Pearson r = 0.39; AUROC 0.72, 95% CI 0.68, 0.77). In comparison, EHR-Alternative 1 classified 219 (29%) patients as ARDS, maintained similar relationships to mortality (r = 0.40; AUROC 0.74, 95% CI 0.70, 0.79, Delong test P = 0.14), and identified patients earlier in their hospitalization (median 13 vs. 15 h from admission, Wilcoxon signed-rank test P < 0.001). EHR-Alternative 3, which removed imaging criteria, had similar correlation (r = 0.41) but better discrimination for mortality (AUROC 0.76, 95% CI 0.72, 0.80; P = 0.036), and identified patients median 2 h (P < 0.001) from admission. CONCLUSIONS: The EHR-Berlin definition can enable ARDS identification with high criterion validity, supporting large-scale study and surveillance. There are opportunities to expand the Berlin criteria that preserve predictive validity and facilitate earlier identification.

Language-model-based patient embedding using electronic health records facilitates phenotyping, disease forecasting, and progression analysis.

Current studies regarding the secondary use of electronic health records (EHR) predominantly rely on domain expertise and existing medical knowledge. Though significant efforts have been devoted to investigating the application of machine learning algorithms in the EHR, efficient and powerful representation of patients is needed to unleash the potential of discovering new medical patterns underlying the EHR. Here, we present an unsupervised method for embedding high-dimensional EHR data at the patient level, aimed at characterizing patient heterogeneity in complex diseases and identifying new disease patterns associated with clinical outcome disparities. Inspired by the architecture of modern language models-specifically transformers with attention mechanisms, we use patient diagnosis and procedure codes as vocabularies and treat each patient as a sentence to perform the patient embedding. We applied this approach to 34,851 unique medical codes across 1,046,649 longitudinal patient events, including 102,739 patients from the electronic Medical Records and GEnomics (eMERGE) Network. The resulting patient vectors demonstrated excellent performance in predicting future disease events (median AUROC = 0.87 within one year) and bulk phenotyping (median AUROC = 0.84). We then illustrated the utility of these patient vectors in revealing heterogeneous comorbidity patterns, exemplified by disease subtypes in colorectal cancer and systemic lupus erythematosus, and capturing distinct longitudinal disease trajectories. External validation using EHR data from the University of Washington confirmed robust model performance, with median AUROCs of 0.83 and 0.84 for bulk phenotyping tasks and disease onset prediction, respectively. Importantly, the model reproduced the clustering results of disease subtypes identified in the eMERGE cohort and uncovered variations in overall mortality among these subtypes. Together, these results underscore the potential of representation learning in EHRs to enhance patient characterization and associated clinical outcomes, thereby advancing disease forecasting and facilitating personalized medicine.

Transcriptional analysis links B cells and TERT expression to favorable prognosis in head and neck cancer.

Telomerase reverse transcriptase (TERT) is a conserved self-tumor antigen overexpressed in ∼85% of tumor cells and is immunogenic in cancer patients. The effect of TERT expression on the regulation of intratumor adaptive immunity has not yet been investigated. We used RNA sequencing data from The Cancer Genome Atlas (TCGA) in 11 solid tumor types to investigate potential interactions between TERT expression, and B and T cell infiltrate in the tumor microenvironment. We found a positive correlation between TERT expression, B and T cells in four cancer types with the strongest association in head and neck squamous cell carcinoma (HSNCC). In HNSCC a Bhigh/TERThigh signature was associated with improved progression-free survival (PFS) (P = 0.0048). This effect was independent of HPV status and not shared in comparable analysis by other conserved tumor antigens (NYESO1, MUC1, MAGE, and CEA). Bhigh/TERThigh HNSCC tumors also harbored evidence of tertiary lymphoid structure (TLS) such as signatures for germinal center (GC) and switched memory B cells, central memory CD4 and effector memory CD8 T cells. Bhigh/TERThigh HNSCC tumors also showed an up-regulation of genes and pathways related to B and T cell activation, proliferation, migration, and cytotoxicity, while factors associated with immunosuppression and cancer cell invasiveness were down-regulated. In summary, our study uncovers a new association between high TERT expression and high B cell infiltrate in HNSCC, suggesting a potential benefit from therapeutic strategies that invigorate intratumor TERT-mediated T-B cooperation.

CAGI6 ID-Challenge: Assessment of phenotype and variant predictions in 415 children with Neurodevelopmental Disorders (NDDs).

In the context of the Critical Assessment of the Genome Interpretation, 6th edition (CAGI6), the Genetics of Neurodevelopmental Disorders Lab in Padua proposed a new ID-challenge to give the opportunity of developing computational methods for predicting patient's phenotype and the causal variants. Eight research teams and 30 models had access to the phenotype details and real genetic data, based on the sequences of 74 genes (VCF format) in 415 pediatric patients affected by Neurodevelopmental Disorders (NDDs). NDDs are clinically and genetically heterogeneous conditions, with onset in infant age. In this study we evaluate the ability and accuracy of computational methods to predict comorbid phenotypes based on clinical features described in each patient and causal variants. Finally, we asked to develop a method to find new possible genetic causes for patients without a genetic diagnosis. As already done for the CAGI5, seven clinical features (ID, ASD, ataxia, epilepsy, microcephaly, macrocephaly, hypotonia), and variants (causative, putative pathogenic and contributing factors) were provided. Considering the overall clinical manifestation of our cohort, we give out the variant data and phenotypic traits of the 150 patients from CAGI5 ID-Challenge as training and validation for the prediction methods development.

The Unfolded Protein Response at the Tumor-Immune Interface.

The tumor-immune interface has surged to primary relevance in an effort to understand the hurdles facing immune surveillance and cancer immunotherapy. Reports over the past decades have indicated a role for the unfolded protein response (UPR) in modulating not only tumor cell fitness and drug resistance, but also local immunity, with emphasis on the phenotype and altered function of immune cells such as myeloid cells and T cells. Emerging evidence also suggests that aneuploidy correlates with local immune dysregulation. Recently, we reported that the UPR serves as a link between aneuploidy and immune cell dysregulation in a cell nonautonomous way. These new findings add considerable complexity to the organization of the tumor microenvironment (TME) and the origin of its altered function. In this review, we summarize these data and also discuss the role of aneuploidy as a negative regulator of local immunity.

IRE1α and IGF signaling predict resistance to an endoplasmic reticulum stress-inducing drug in glioblastoma cells.

To date current therapies of glioblastoma multiforme (GBM) are largely ineffective. The induction of apoptosis by an unresolvable unfolded protein response (UPR) represents a potential new therapeutic strategy. Here we tested 12ADT, a sarcoendoplasmic reticulum Ca2+ ATPase (SERCA) inhibitor, on a panel of unselected patient-derived neurosphere-forming cells and found that GBM cells can be distinguished into "responder" and "non-responder". By RNASeq analysis we found that the non-responder phenotype is significantly linked with the expression of UPR genes, and in particular ERN1 (IRE1) and ATF4. We also identified two additional genes selectively overexpressed among non-responders, IGFBP3 and IGFBP5. CRISPR-mediated deletion of the ERN1, IGFBP3, IGFBP5 signature genes in the U251 human GBM cell line increased responsiveness to 12ADT. Remarkably, >65% of GBM cases in The Cancer Genome Atlas express the non-responder (ERN1, IGFBP3, IGFBP5) gene signature. Thus, elevated levels of IRE1α and IGFBPs predict a poor response to drugs inducing unresolvable UPR and possibly other forms of chemotherapy helping in a better stratification GBM patients.

The RUNX1-ETO target gene RASSF2 suppresses t(8;21) AML development and regulates Rac GTPase signaling.

Large-scale chromosomal translocations are frequent oncogenic drivers in acute myeloid leukemia (AML). These translocations often occur in critical transcriptional/epigenetic regulators and contribute to malignant cell growth through alteration of normal gene expression. Despite this knowledge, the specific gene expression alterations that contribute to the development of leukemia remain incompletely understood. Here, through characterization of transcriptional regulation by the RUNX1-ETO fusion protein, we have identified Ras-association domain family member 2 (RASSF2) as a critical gene that is aberrantly transcriptionally repressed in t(8;21)-associated AML. Re-expression of RASSF2 specifically inhibits t(8;21) AML development in multiple models. Through biochemical and functional studies, we demonstrate RASSF2-mediated functions to be dependent on interaction with Hippo kinases, MST1 and MST2, but independent of canonical Hippo pathway signaling. Using proximity-based biotin labeling we define the RASSF2-proximal proteome in leukemia cells and reveal association with Rac GTPase-related proteins, including an interaction with the guanine nucleotide exchange factor, DOCK2. Importantly, RASSF2 knockdown impairs Rac GTPase activation, and RASSF2 expression is broadly correlated with Rac-mediated signal transduction in AML patients. Together, these data reveal a previously unappreciated mechanistic link between RASSF2, Hippo kinases, and Rac activity with potentially broad functional consequences in leukemia.

[Correlation between ABO blood type gene and attention-deficit hyperactivity disorder in children].

OBJECTIVE: To investigate the correlation between ABO blood type gene and attention-deficit hyperactivity disorder (ADHD) in children. METHODS: ABO blood types were determined using glass sheet method in 96 children with ADHD and their parents. O gene was identified using polymerase chain reaction and restriction fragment length polymorphism in patients with A or B blood type. Haplotype-based haplotype relative risk (HHRR), transmission-disequilibrium test (TDT) and Chi-square test were used to examine the association between ABO gene and ADHD. RESULTS: TDT results showed significant differences in the allele of ABO between the 96 children with ADHD and within-family controls (chi2=6.017, df=2, P< 0.05). Chi-square test results showed differences in the allele of A and B (chi2=3.289, df=1, P=0.07) as well as O and B (chi2=3.629, df=1, P=0.057 ) between ADHD children and within-family controls. The frequencies of O and A genes were higher than that of B gene in ADHD children. CONCLUSIONS: There was correlation between ABO blood type gene and ADHD in children. The risk of ADHD is increased in the presence of alleles O and A, but the risk is reduced in the presence of allele B.

Elevated neoantigen levels in tumors with somatic mutations in the HLA-A, HLA-B, HLA-C and B2M genes.

BACKGROUND: The major histocompatibility complex class I (MHC-I) molecule is a protein complex that displays intracellular peptides to T cells, allowing the immune system to recognize and destroy infected or cancerous cells. MHC-I is composed of a highly polymorphic HLA-encoded alpha chain that binds the peptide and a Beta-2-microglobulin (B2M) protein that acts as a stabilizing scaffold. HLA mutations have been implicated as a mechanism of immune evasion during tumorigenesis, and B2M is considered a tumor suppressor gene. However, the implications of somatic HLA and B2M mutations have not been fully explored in the context of antigen presentation via the MHC-I molecule during tumor development. To understand the effect that B2M and HLA MHC-I molecule mutations have on mutagenesis, we analyzed the accumulation of mutations in patients from The Cancer Genome Atlas according to their MHC-I molecule mutation status. RESULTS: Somatic B2M and HLA mutations in microsatellite stable tumors were associated with higher overall mutation burden and a larger fraction of HLA-binding neoantigens when compared to B2M and HLA wild type tumors. B2M and HLA mutations were highly enriched in patients with microsatellite instability. B2M mutations tended to occur relatively early during patients' respective tumor development, whereas HLA mutations were either early or late events. In addition, B2M and HLA mutated patients had higher levels of immune infiltration by natural killer and CD8+ T cells and higher levels of cytotoxicity. CONCLUSIONS: Our findings add to a growing body of evidence that somatic B2M and HLA mutations are a mechanism of immune evasion by demonstrating that such mutations are associated with a higher load of neoantigens that should be presented via MHC-I.

[Spectra and structural analysis of high boiling solvent lignin from Bagasse].

Bagasse high boiling solvent lignin is a polymer prepared by high boiling solvent pulping process. In the IR spectra, the absorbance of HBS lignin at 1700 and 1 328 cm(-1) is present. It is showed that the nonconjugated carbonyl existed. The strong absorbance of UV spectra of HBS lignin is about 201 nm for n-->pi electron transition, which indicates that the HBS lignin is an unsaturated polymer. Judged from the 1H NMR, the syringyl and guaiacyl group in the lignin is present. The element composition and the content of OCH3 group were investigated. The empirical C9-formula of the lignin is C9H9.79O2.58(OCH)0.75 according to dealing with the experiment data. The weight-average molecular weight of the HBS lignin is 2674 g x mol(-1).

[Influence of zirconia content on translucency of zirconia-toughened alumina glass-infiltrated ceramic].

OBJECTIVE: The objective of this study is to investigate the influence of zirconia content which is 0-30.0% weight percentage of matrix on translucency of zirconia-toughened alumina glass-infiltrated ceramics. METHODS: Seven groups were divided according to different weight percentage of zirconia (0, 2.5%, 5.0%, 7.5%, 10.0%, 20.0% and 30.0%). After sintering, infiltrating and polishing, spectral transmittance was determined with spectrophotometer under D65 standard source. Contrast ratio was also tested by whiteness colorimeter. RESULTS: With mass fraction of zirconia increasing from 0 to 30.0%, spectral transmittance reduced from 0.406% to 0.058%, while contrast ratio value increased from 0.849 +/- 0.005 to 1.015 +/- 0.006. When zirconia content was 10.0%, contrast ratio was 0.990 +/- 0.008. When it was more than 10.0%, transmission rate of the downward trend and contrast ratio of the rising trend became flat. CONCLUSION: Zirconia content has a direct impact on translucency of zirconia-toughened alumina glass-infiltrated ceramic, which is essentially opaque when zirconia content is 10.0%. When mass fraction of zirconia is more than 10.0%, the influence of zirconia content is reduced.

[Influence of surface modification of titanium on OPG/RANKL mRNA expression in MG-63 human osteoblast-like cells].

OBJECTIVE: To investigate the influence of surface modification of titanium on OPG/RANKL mRNA expression in human osteoblast-like cells. METHODS: MG-63 osteoblast-like cells were seeded on the titanium plates with surface polishing and with surface modification by sandblasting plus acid-base treatment, with the cells on glass slides as the control. On days 2, 4, 6, and 8 following cell seeding, the cells were harvested for examination of OPG/RANKL mRNA expression using RT-PCR and real-time PCR. RESULTS: The expression of OPG/RANKL mRNA was sensitive to the surface microphotography. Compared with the other groups, the cells on the titanium plates with sandblasting plus acid-base treatment, which resulted in a porous micro-structure and high roughness, showed significantly up-regulated expression of OPG mRNA. OPG mRNA expression also showed a time-dependent up-regulation, and was the highest on day 8. The expression of the RANKL mRNA in cells on both of the titanium plates was higher than that in the control cells. The peak level of RANKL mRNA expression occurred on day 6 followed by a gradual decrease. CONCLUSION: A rough and porous surface of the culture plates and prolonged culture time can synergistically up-regulate the ratio of OPG/RANKL mRNA.

[Observation on osteoblasts responded to fluid induced shear cultured on different surfaces with scanning electron microscope].

OBJECTIVE: To investigate morphological change of osteoblasts cultured on titanium plates with different microarchitecture structure when exposured to fluid shear stress. METHODS: 14 dynes x cm(-2) fluid shear stress was applied on osteoblasts cultured on 3 different commercially pure titanium plates: Polished treatment (PT), sandblast (SB), sandblasting and acid-base (SB-AB) surfaces. Scanning electron microscope (SEM) was adopted to observe the morphological changes after 0.5, 4, 7.5 h time point respectively. RESULTS: Morphologically, no significant changes were observed after 0.5 h and few osteoblasts were seen after 7.5 h on all 3 type of different surfaces, and significant changes could only be observed after 4 h. Osteoblasts were elongated and rearranged along the flow way on different levels on PT surface. Shape of cells was altered, from long fusiform suspending over depressed areas into polygon stretching out many synapsises tightly attached to pits on SB-AB surface. Osteoblasts on SB surface displayed similar change as SB-AB surface, besides, some cells were elongated along the way of flow, stretching out threadlike synapsises attached to edges of pits. CONCLUSION: Morphological change of osteoblast responding to fluid shear stress in physiological range depends on substrate microarchitecture and varies with the time of fluid shear stress application.

[Characterization and antibacterial effect of Ag-nHA-nTiO2/polyamide 66 nanocomposite membrane on oral bacteria].

OBJECTIVE: Undried silver-hydroxyapatite-titania (Ag-nHA-nTiO2) nanoparticles slurry was used to make membrane with polyamide 66 (PA66) by co-polymerization method. The purpose of this study is to test the physical and chemical characteristics and antibacterial ability. METHODS: The morphology, chemical components and structures of the membrane were characterized by atomic absorption spectrometer (AAS), X-ray diffraction (XRD), scanning electron microscope (SEM) and energy-dispersive X-ray analysis (EDX). Staphylococcus aureus (S. aureus), Escherichia coli (E. coli), Porphyromonas gingivalis (P. gingivalis), Fusobacterium nucleatum (F. nucleatum) and Streptococcus mutans (S. mutans) were utilized to test the antibacterial effect. RESULTS: XRD results demonstrated that the membrane have characteristic diffraction peaks of pure hydroxyapatite (HA). A homogeneous distribution of the Ca, P, Ti and Ag element in the membrane was confirmed by EDX. Both surface and section showed porous structure which was confirmed by SEM and the average hole size was 20-30 microm. The bacteria assay reflected to the antibacterial effect, 50.10% of S. aureus and 56.31% of E. coli were killed. However, 91.84% of P. gingivalis, 90.64% of F. nucleatum and 90.49% of S. mutans were killed and pictures of SEM showed obviously fewer cells on the surface. CONCLUSION: The nanocomposite membrane could be one of the bioactive materials with antibacterial properties for oral guided bone regeneration technique.

catena-poly[[[pyridinecopper(II)]bis[mu3-4-(2-oxidobenzylideneamino)benzoato]] dimethylformamide disolvate], a polymer composed of dimeric dicopper building units.

The title compound, {[Cu(C(14)H(9)NO(3))(C(5)H(5)N)].C(3)H(7)NO}n or {[Cu(2)L(2)(py)(2)].2DMF}n [py is pyridine, L is 4-(salicylideneamino)benzoate and DMF is dimethylformamide], is composed of dimeric dicopper [CuL(py)]2 building units, which are interlinked into a one-dimensional chain through the formation of Cu-O(COO) bonds. The dimeric unit is centrosymmetric, containing two Cu(II) atoms linked by bridging phenolate O atoms into a Cu(2)O(2) plane with a chelating Cu-O bond length of 1.927 (2) A and a bridging Cu-O bond length of 2.440 (2) A. Interchain C-H...O and pi-pi stacking interactions are responsible for an extensive three-dimensional structure in which the resulting channels are filled by DMF solvent molecules.

[Investigation of the function of the glass colorant on the machinable infiltrated ceramics color].

OBJECTIVE: To investigae the function of the glass colorant on the color of the machinable infiltrated ceramics(MIC). METHODS: Five kinds of glass with different colorant were infiltrated through the aluminous matrix by heating the components to 1 100 degrees C for 2 hours. The specimens surface was polished, and their thickness was 0.5 mm. RESULTS: The refractive index of the MIC infiltration glass was 1.59691 (587.6 nm, nd) . The most different parameter of the MIC color were L*, then a*, and b* had little difference . The parameters of the color space of MIC were: L*(64.55-71.46), a*(3.35-7.38), b*(10.00-12.41), Ca*b*(11.38-13.95), ha*b*(54.07-73.00). These were almost close to the color parameters of Vita In-ceram. CONCLUSION: This experiment proved that the glass colorant was changed the MIC color parameters, and the main function was on L*, then a*. The ceramic color was up to the requirement of clinic.

[Experimental study of periosteal osteoblasts adhesion to artificial bone scaffolds based on rapid prototype].

OBJECTIVE: To study the biocompatibility of bone engineering scaffolds designed and fabricated by CAD and Rapid Prototyping techniques. METHODS: Infant rat calvarias osteoblasts were isolated and expanded in vitro and the cells (2nd passage) were seeded onto scaffolds with porosity 80%, 90%, 95% at a density of 2.06 x 10(9)/L. Cell adhesion number and morphology were measured with SEM after 4 days, 10 days co-culture. RESULTS: (1) The osteoblasts' adhesion amounts increased with culture time in three porosity group (P < 0.05), but the increase were different among three groups, 80% group was 0.35 x 10(5), 90% group was 2.84 x 10(5); (2) Through SEM observations, it showed that osteoblasts adhered to all scaffolds well. CONCLUSION: The scaffolds designed and fabricated by CAD and rapid prototyping own a good cellular biocompatibility. The results suggest the feasibility of using such scaffold fabricating method for bone tissue engineering research and clinical therapy.