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The Journal of Physical Chemistry. B Jul 2024A combined experimental and simulation study of dielectric relaxation (DR) of a deep eutectic solvent (DES) composed of betaine, urea, and water with the composition...
Temperature-Dependent Dielectric Relaxation Measurements of (Betaine + Urea + Water) Deep Eutectic Solvent in Hz-GHz Frequency Window: Microscopic Insights into Constituent Contributions and Relaxation Mechanisms.
A combined experimental and simulation study of dielectric relaxation (DR) of a deep eutectic solvent (DES) composed of betaine, urea, and water with the composition [Betaine:Urea:Water = 11.7:12:1 (weight ratio) and 9:18:5 (molar ratio)] was performed to explore and understand the interaction and dynamics of this system. Temperature-dependent (303 ≤ / ≤ 343) measurements were performed over 9 decades of frequency, combining three different measurement setups. Measured DR, comprising four distinct steps with relaxation times spreading over a few picoseconds to several nanoseconds, was found to agree well with simulations. The simulated total DR spectra, upon dissection into three self (intraspecies) and three cross (interspecies) interaction contributions, revealed that the betaine-betaine self-term dominated (∼65%) the relaxation, while the urea-urea and water-water interactions contributed only ∼7% and ∼1%, respectively. The cross-terms (betaine-urea, betaine-water, and urea-water) together accounted for <30% of the total DR. The slowest DR component with a time constant of ∼1-10 ns derived dominant contribution from betaine-betaine interactions, where betaine-water and urea-water interactions also contributed. The subnanosecond (0.1-0.6 ns) time scale originated from all interactions except betaine-water interaction. An extensive interaction of water with betaine and urea severely reduced the average number of water-water H-bonds (∼0.7) and heavily decreased the static dielectric constant of water in this DES (ε ∼ 2). Furthermore, simulated first rank collective single particle reorientational relaxations (()) and the structural H-bond fluctuation dynamics ( ()) exhibited multiexponential kinetics with time scales that corresponded well with those found both in the simulated and measured DR.
PubMed: 38949428
DOI: 10.1021/acs.jpcb.4c02784 -
Zhonghua Kou Qiang Yi Xue Za Zhi =... Jul 2024Congenital tooth agenesis is a type of craniofacial developmental anomaly with reduced number of teeth, which is caused by disturbances in tooth germ development. If the...
Congenital tooth agenesis is a type of craniofacial developmental anomaly with reduced number of teeth, which is caused by disturbances in tooth germ development. If the number of missing teeth is less than six (excluding the third molars), it is termed as hypodontia. The second premolars are most commonly affected. When the second premolars are missing, the second primary molars are more prone to suffer from retention, infraocclusion, caries, pulpitis, or periapical periodontitis. Without timely prevention and appropriate treatment, congenital loss of second premolars may cause adverse effects on the patients' tooth arrangement, occlusal function, craniofacial development, and even future prosthetic treatment. This review summarises the aetiological and diagnostic features of the agenesis of second premolars, and discusses the clinical considerations of retaining or extracting the second primary molars without permanent tooth germs, when the absence of permanent tooth germs is fully established or not, so as to provide references for dentists.
PubMed: 38949144
DOI: 10.3760/cma.j.cn112144-20240317-00113 -
Zhonghua Kou Qiang Yi Xue Za Zhi =... Jul 2024Explore the expression pattern of transcription factor activator protein 2C (Tfap2c) and identify the roles of Tfap2c during tooth development. Real-time quantitative...
Explore the expression pattern of transcription factor activator protein 2C (Tfap2c) and identify the roles of Tfap2c during tooth development. Real-time quantitative PCR (RT-qPCR) was used to analyze the relative expression level of Tfap2c in various organs of embryo day(E)14.5 mouse embryos and mouse molar germs at E12.5-E18.5 and postnatal day (P)0-P7. The expression position of Tfap2c in mouse molar germs was demonstrated by frozen section immunofluorescence staining. Cultured mandibular molar germs were transfected with control siRNA or Tfap2c siRNA to evaluate the effect of Tfap2c on tooth molar germs development, and RT-qPCR was used to detect the relative expression level of genes related to odontoblast expression. Dental mesenchymal cells were isolated from E14.5 molar germs and transfected with control siRNA or Tfap2c siRNA, cell counting kit 8 and scratch healing test were applied to detect dental mesenchymal cell viability and migration. Tfap2c was highly expressed in the early development period of mouse molar germs. Tfap2c was expressed in the epithelial and mesenchymal tissues of E13.5 mouse molar germs and there was no significant difference of relative expression of Tfap2c between them (=1.06, =0.472). Tfap2c was expressed in mesenchymal tissues of E14.5 mouse molar germs and the relative expression of Tfap2c in mesenchymal tissues was significantly higher than epithelial tissues (=37.29, <0.0001). For molar germs transfected with Tfap2c siRNA, the relative height of cusps (0.708±0.171) and the ratio of cusp height and crown height (0.321±0.068) was significantly lower than control group (1.000±0.287 and 0.483±0.166) (=2.79, =0.012; =2.85, =0.015). But there was no significant difference in relative height (1.078±0.206, 0.993±0.254, =0.83, =0.419)and relative width (1.000±0.116, 0.999±0.122, =0.01, =0.992) of crowns between two groups. The relative expression level of genes related to odontoblast expression was decreased (Dspp: 15.33, <0.001; Dmp1: 13.81, <0.001). Tfap2c siRNA hinders cell migration in dental mesenchymal cells (=29.86, =0.001), but there was no significant difference in CCK8 absorbance value between two groups. The relative expression level of genes related to odontoblast expression was also decreased in dental mesenchymal cells transfected with Tfap2c siRNA (Dspp: 3.86, =0.031; Dmp1; 4.36, =0.022). Tfap2c highly expressed in the early morphogenesis period of mouse molar germs, mainly in mesenchymal tissues. Tfap2c affected the cusps formation of mouse molar germs and migration of dental mesenchymal cells.
PubMed: 38949139
DOI: 10.3760/cma.j.cn112144-20240511-00198 -
Zhonghua Kou Qiang Yi Xue Za Zhi =... Jul 2024To investigate the presence of a distinct stem cell populations different from mesenchymal stem cells in the mandibular periosteum of both human and non-human primates...
To investigate the presence of a distinct stem cell populations different from mesenchymal stem cells in the mandibular periosteum of both human and non-human primates (macaca mulatta), to explore its properties during intramembranous osteogenesis and to establish standard protocols for the isolation, culturing and expanding of mandibular periosteal stem cells (PSCs) distinguished from other PSCs in other anatomical regions. Periosteum was harvested from the bone surface during flap bone removal in patients aged 18-24 years undergoing third molar extraction and from the buccal side of the mandibular premolar region of 1-year-old macaca mulatta respectively, and then subjected to single-cell sequencing using the Illumina platform Novaseq 6000 sequencer. Cross-species single-cell transcriptome sequencing results were compared using homologous gene matching. PSCs were isolated from primary tissues using two digestion methods with body temperature and low temperature, and their surface markers (CD200, CD31, CD45 and CD90) were identified by cell flow cytometry. Then, the ability of cell proliferation and three-lineage differentiation of PSCs expanded to the third generation in different species were evaluated. Finally, the similarities and differences in osteogenic properties of periosteal stem cells and bone marrow mesenchymal stem cells were compared. The single-cell sequencing results indicated that 18 clusters of cell populations were identified after homologous gene matching for dimensionality reduction, and manual cellular annotation was conducted for each cluster based on cell marker databases. The comparison of different digestion protocols proved that the low-temperature overnight digestion protocol can stably isolate periosteal stem cells from the human and mandibular periosteum and the cells exhibited a fibroblast-like morphology. This research confirmed that periosteal stem cells of human and had similar proliferation capabilities through the cell counting kit-8 assay. Flow cytometry analysis was then used to identify the cells isolated from the periosteum expressed CD200(+), CD31(-), CD45(-), CD90(-). Then, human and periosteal stem cells were induced into osteogenesis, adipogenesis, and chondrogenesis to demonstrate their corresponding multi-lineage differentiation capabilities. Finally, comparison with bone marrow mesenchymal stem cells further clarified the oesteogenesis characteristics of periosteal stem cells. The above experiments proved that the cells isolated from the periosteum were peiosteal cells with characteristics of stem cells evidenced by their cell morphology, proliferation ability, surface markers, and differentiation ability, and that this group of periosteal stem cells possessed characteristics different from traditional mesenchymal stem cells. In this study, normal mandibular periosteal stem cells from humans and were stably isolated and identified for the first time, providing a cellular foundation for investigating the mechanism of mandibular intramembranous osteogenesis, exploring ideal non-human primate models and establishing innovative strategies for clinically mandibular injury repair.
PubMed: 38949138
DOI: 10.3760/cma.j.cn112144-20240205-00066 -
Zhonghua Kou Qiang Yi Xue Za Zhi =... Jul 2024To investigate the therapeutic effect of methotrexate loaded vesicles on experimental periodontitis in mice. Extracellular vesicles (EVs) were isolated from human...
To investigate the therapeutic effect of methotrexate loaded vesicles on experimental periodontitis in mice. Extracellular vesicles (EVs) were isolated from human umbilical cord mesenchymal stem cells (hUC-MSC). Methotrexate loaded vesicles (MTX-EVs) were constructed, whose morphology and size were analyzed by using scanning electron microscopy and particle size analyzer. Western blotting was used to identify their surface specific proteins. C57BL/6J male mice of 4-5 weeks (provided by Experimental Animal Center of the Fourth Military Medical University) were selected, among which 8 were randomly selected by blind grasp method without treatment and fed normally as normal group, and others were induced to periodontitis models by local injection of lipopolysaccharide (LPS) into the periodontium. The LPS was injected once every day with a concentration of 2 g/L and a volume of 5 μl, lasting for two weeks. The mice with successfully induced periodontitis were randomly divided into 4 groups by blind grasping method, with 8 mice in each group. The LPS group was with no treatment, and the other three groups were treated with periodontal local injection of MTX, EVs or MTX-EVs, respectively. Two weeks later, enzyme-linked immunosorbent assay (ELISA) was used to detect the expressions of inflammatory cytokine interleukin (IL)-1β, IL-6 and tumor necrosis factor-α (TNF-α) in gingival tissue. The amount of alveolar bone resorption of four groups was detected by using micro-CT scanning and HE staining. The expression proportion of the inflammatory factor in gingival tissue was analyzed by using flow cytometry. The scanning electron microscopy results showed that EVs and MTX-EVs were circular or elliptical in shape. Dynamic light scattering (DLS) particle size analysis showed that the particle size of EVs was around 200 nm, while that of MTX-EVs was around 300 nm. The ELISA results showed IL-1β levels in the normal group, LPS group, LPS+MTX group, LPS+EVs group and LPS+MTX-EVs group were (28.86±2.76), (51.50±2.04), (35.26±2.40), (45.49±2.04) and (35.77±3.49) ng/L. That is, the IL-1β concentrations in the LPS+MTX group, LPS+EVs group and LPS+MTX-EVs group were significantly lower than that in the LPS group (0.05); the mass concentration of IL-1β in the LPS +MTX-EVs group was significantly lower than that in the LPS+EVs group (0.05). The concentrations of IL-6 in the normal group, LPS group, LPS+MTX group, LPS+EVs group and LPS+MTX-EVs group were (125.44±4.12), (221.64±10.59), (178.16±16.90), (181.09±18.22) and (170.15±9.04) ng/L, among which the concentration of IL-6 in the last three groups were significantly lower than that in the LPS group (0.05). The mass concentration of IL-6 in the LPS+MTX-EVs group was significantly lower than those in the LPS+MTX group and LPS+EVs group (0.05). The concentrations of TNF-α in the normal group, LPS group, LPS+MTX group, LPS+EVs group and LPS+MTX-EVs group were (320.27±38.68), (479.62±40.94), (342.18±25.89), (415.88±12.01) and (325.75±30.83) ng/L, among which the concentrations of last three groups were significantly lower than the LPS group (0.05); the mass concentration of TNF-α in the LPS+MTX-EVs group was significantly lower than those in the LPS+EVs group and LPS+MTX group (0.05). The micro-CT results showed that the distance of cement-enamel junction-alveolar bone crest (CEJ-ABC) of the first molar and root (M1R1) in the normal group, LPS group, LPS+MTX group, LPS+EVs group and LPS+MTX-EVs group of mice were (0.11±0.03), (0.28±0.02), (0.23±0.03), (0.20±0.04), and (0.18±0.03) mm, respectively. Compared with the LPS group, the CEJ-ABC of the M1R1 in the LPS+MTX group, LPS+EVs group and LPS+MTX-EVs group were inhibited to varied degrees with statistically significant differences (0.05). Among them, LPS+MTX-EVs group had the best bone resorption inhibitioin effect compared to LPS+MTX group and LPS+EVs group, and the differences were statistically significant (0.05). The flow cytometry results indicated that the proportion of interferon-γ (IFN-γ) positive cells was (11.77±1.02)% in the LPS group, (6.87±0.65)% in the LPS+EVs group, and (4.15±0.92)% in the LPS+MTX-EVs group, respectively. The proportions of IFN-γ positive cells in the LPS+EVs group and LPS+MTX-EVs group were significantly lower than that in the LPS group (0.05), while the ratio of IFN-γ positive cells in the LPS+MTX-EVs group was found significantly lower than that in the LPS+EVs group (0.05). MTX-EVs can effectively alleviate the periodontal local inflammatory environment and reduce bone resorption of alveolar bone in periodontitis model mice.
PubMed: 38949136
DOI: 10.3760/cma.j.cn112144-20231114-00249 -
Molecular Pharmaceutics Jul 2024Claudin18.2 CLDN18.2), due to its high expression in various gastric cancer tissues, is considered an optimal target for antitumor drug molecules. In this study, we...
Claudin18.2 CLDN18.2), due to its high expression in various gastric cancer tissues, is considered an optimal target for antitumor drug molecules. In this study, we obtained the labeled compounds of [I]I-zolbetuximab using the Iodogen method. Under the optimum labeling conditions, the molar activity of [I]I-zolbetuximab was 1.75 × 10 GBq/μmol, and the labeling efficiency was more than 99%. The labeled compounds exhibited excellent in vitro stability in both phosphate buffer saline (PBS, pH = 7.4) and fetal bovine serum systems (FBS) (radiochemical purity >90% at 72 h). The uptake percentage of [I]I-zolbetuximab in MKN45-CLDN18.2 cells is 24.69 ± 0.84% after 6 h. The saturation binding assay and specificity assay further demonstrated the high specificity of [I]I-zolbetuximab for CLDN18.2. The long retention at the tumor site and rapid metabolic clearance at other organ sites of [I]I-zolbetuximab were observed in small-animal SPECT-CT imaging. The same trend was also observed in the biodistribution study. Due to the excellent targeting ability of zolbetuximab for CLDN18.2, [I]I-zolbetuximab exhibits strong specific binding and retention with cells and tumors highly expressing CLDN18.2. However, the balance between mAb's longer cycle time in vivo and targeting binding and retention ability should be intensively considered for using this kind of radiopharmaceutical in the diagnosis and treatment of CLDN18.2-positive gastric cancer.
PubMed: 38949095
DOI: 10.1021/acs.molpharmaceut.4c00122 -
JPMA. the Journal of the Pakistan... Jun 2024Recurrent rhinorrhoea that occurs chronically, needs to consider the possibility of a fistula in the nasal cavity, which has the potential to form a rhinolith. We report...
Recurrent rhinorrhoea that occurs chronically, needs to consider the possibility of a fistula in the nasal cavity, which has the potential to form a rhinolith. We report the case of a 39-year-old man with complaints of recurrent rhinorrhoea since four years ago, accompanied by thick secretions, symptoms of post-nasal drips, and olfactory disturbances. The patient had a history of removing the left upper molar (molar I), which causes a fistula in the tooth extraction site, making it more likely for food and drink to enter the left nasal cavity. Anterior rhinoscopy examination revealed a white mass in the left inferior meatus and a purulent odour discharge. In addition, there were gingival defects of the first molar teeth, multi-sinusitis, and nasal septum deviation. Rinolith extraction was performed using functional endoscopic sinus surgery, submucosal resection, and repair of gingivo-nasal defects with rotational flaps. Follow-up for one week showed that the flap was in place and there were no complications.
Topics: Humans; Male; Adult; Rhinorrhea; Nose Diseases; Chronic Disease; Tooth Extraction; Endoscopy; Oral Fistula; Surgical Flaps
PubMed: 38948996
DOI: 10.47391/JPMA.9784 -
Imaging Science in Dentistry Jun 2024Non-secretory multiple myeloma (NSMM) is a rare cancer of plasma cells characterized by the absence of detectable monoclonal M protein in the blood or urine. A...
Non-secretory multiple myeloma (NSMM) is a rare cancer of plasma cells characterized by the absence of detectable monoclonal M protein in the blood or urine. A 57-year-old woman presented with mandibular pain but without intraoral swelling. Imaging studies revealed multiple osteolytic lesions in her mandible and pronounced root resorption of the left mandibular second molar. Biopsy results showed atypical plasmacytoid cells positive for anti-kappa, CD138, MUM1, and CD79a antibodies, but negative for anti-lambda and CD20. These results were indicative of a malignant plasma cell neoplasm. No abnormalities were revealed by free light chain assay or by serum or urine protein electrophoresis, leading to a diagnosis of NSMM. The patient began chemotherapy in conjunction with bisphosphonate therapy and achieved remission following treatment. This case underscores the critical role of dentists in the early detection and prevention of NSMM complications, as the disease can initially present in the oral cavity.
PubMed: 38948192
DOI: 10.5624/isd.20230257 -
Imaging Science in Dentistry Jun 2024Ameloblastic fibrodentinoma (AFD) is a rare benign odontogenic tumor that resembles an ameloblastic fibroma with dysplastic dentin. This report presents a rare case of...
Ameloblastic fibrodentinoma (AFD) is a rare benign odontogenic tumor that resembles an ameloblastic fibroma with dysplastic dentin. This report presents a rare case of mandibular AFD with imaging features in a young patient. Panoramic radiography and computed tomography revealed a well-defined lesion with internal septa and calcified foci, causing inferior displacement of the adjacent molars as well as buccolingual cortical thinning and expansion of the posterior mandible. The lesion was surgically removed via mass excision, and the involved tooth was extracted under general anesthesia. During the 5-year follow-up period, no evidence of recurrence was observed. Radiologic features of AFD typically reveal a moderately to well-defined mixed lesion with varying degrees of radiopacity, reflecting the extent of dentin formation. Radiologists should consider AFD in the differential diagnosis when encountering a multilocular lesion with little dense radiopacity, particularly if it is associated with delayed eruption, impaction, or absence of involved teeth, on radiographic images of young patients.
PubMed: 38948190
DOI: 10.5624/isd.20230247 -
Imaging Science in Dentistry Jun 2024This study was conducted to identify the typical sites and patterns of peri-implant bone defects on cone-beam computed tomography (CBCT) images, as well as to evaluate...
PURPOSE
This study was conducted to identify the typical sites and patterns of peri-implant bone defects on cone-beam computed tomography (CBCT) images, as well as to evaluate the detectability of the identified bone defects on panoramic images.
MATERIALS AND METHODS
The study population included 114 patients with a total of 367 implant fixtures. CBCT images were used to assess the presence or absence of bone defects around each implant fixture at the mesial, distal, buccal, and lingual sites. Based on the number of defect sites, the presentations of the peri-implant bone defects were categorized into 3 patterns: 1 site, 2 or 3 sites, and circumferential bone defects. Two observers independently evaluated the presence or absence of bone defects on panoramic images. The bone defect detection rate on these images was evaluated using receiver operating characteristic analysis.
RESULTS
Of the 367 implants studied, 167 (45.5%) had at least 1 site with a confirmed bone defect. The most common type of defect was circumferential, affecting 107 of the 167 implants (64.1%). Implants were most frequently placed in the mandibular molar region. The prevalence of bone defects was greatest in the maxillary premolar and mandibular molar regions. The highest kappa value was associated with the mandibular premolar region.
CONCLUSION
The typical bone defect pattern observed was a circumferential defect surrounding the implant. The detection rate was generally higher in the molar region than in the anterior region. However, the capacity to detect partial bone defects using panoramic imaging was determined to be poor.
PubMed: 38948187
DOI: 10.5624/isd.20230258