scholarly journals Age-dependent decrease in dental pulp cavity volume as a feature for age assessment: a comparative in vitro study using 9.4-T UTE-MRI and CBCT 3D imaging

Author(s):  
Maximilian Timme ◽  
Jens Borkert ◽  
Nina Nagelmann ◽  
Adam Streeter ◽  
André Karch ◽  
...  

AbstractEvaluation of secondary dentin formation is generally suitable for age assessment. We investigated the potential of modern magnetic resonance imaging (MRI) technology to visualize the dental pulp in direct comparison with cone beam computed tomography (CBCT). To this end, we examined 32 extracted human teeth (teeth 11–48 [FDI]) using 9.4-T ultrashort echo time (UTE)-MRI and CBCT (methods). 3D reconstruction was performed via both manual and semi-automatic segmentation (settings) for both methods in two runs by one examiner. Nine teeth were also examined by a second examiner. We evaluated the agreement between examiners, scan methods, and settings. CBCT was able to determine the pulp volume for all teeth. This was not possible for two teeth on MRI due to MRI artifacts. The mean pulp volume estimated by CBCT was consistently higher (~ 43%) with greater variability. With lower variability in its measurements, evaluation of pulp volume using the MRI method exhibited greater sensitivity to differences between settings (p = 0.016) and between examiners (p = 0.009). The interactions of single-rooted teeth and multi-rooted teeth and method or setting were not found to be significant. For examiner agreement, the mean pulp volumes were similar with overlapping measurements (ICC > 0.995). Suitable for use in age assessment is 9.4-T UTE-MRI with good reliability and lower variation than CBCT. For MRI, manual segmentation is necessary due to a more detailed representation of the interior of the pulp cavity. Since determination of pulp volume is expected to be systematically larger using CBCT, method-specific reference values are indispensable for practical age assessment procedures. The results should be verified under in vivo conditions in the future.

2020 ◽  
Vol 134 (6) ◽  
pp. 2283-2288
Author(s):  
Maximilian Timme ◽  
Jens Borkert ◽  
Nina Nagelmann ◽  
Andreas Schmeling

Abstract Dental methods are an important element of forensic age assessment of living persons. After the development of all the teeth, including third molars, is completed, degenerative characteristics can be used to assess age. The radiologically detectable reduction of the dental pulp cavity has been described as such a feature. We investigated the suitability of ultrahigh field 9.4 T ultrashort time echo (UTE) magnetic resonance imaging (MRI) for the evaluation of pulp cavity volume in relation to the total tooth volume in 4 extracted human teeth. The volume calculations were performed after semi-automatic segmentation by software AMIRA using the different intensities of the structures in the MRI dataset. The automatically selected intensity range was adjusted manually to the structures. The visual distinction of pulp and tooth structure was possible in all cases with in-plane resolution < 70 μm. Ratios of tooth/pulp volume were calculated, which could be suitable for age estimation procedures. Intensity shifts within the pulp were not always correctly assigned by the software in the course of segmentation. 9.4 T UTE-MRI technology is a forward-looking, radiation-free procedure that allows the volume of the dental pulp to be determined at high spatial resolution and is thus potentially a valuable instrument for the age assessment of living persons.


1993 ◽  
Vol 70 (04) ◽  
pp. 676-680 ◽  
Author(s):  
H F Kotzé ◽  
V van Wyk ◽  
P N Badenhorst ◽  
A du P Heyns ◽  
J P Roodt ◽  
...  

SummaryPlatelets were isolated from blood of baboons and treated with neuraminidase to remove platelet membrane sialic acid, a process which artificially ages the platelets. The platelets were then labelled with 111In and their mean life span, in vivo distribution and sites of Sequestration were measured. The effect of removal of sialic acid on the attachment of immunoglobulin to platelets were investigated and related to the Sequestration of the platelets by the spleen, liver, and bone marrow. Removal of sialic acid by neuraminidase did not affect the aggregation of platelets by agonists in vitro, nor their sites of Sequestration. The removal of 0.51 (median, range 0.01 to 2.10) nmol sialic acid/108 platelets shortened their life span by 75 h (median, range 0 to 132) h (n = 19, p <0.001), and there was an exponential correlation between the shortening of the mean platelet life span and the amount of sialic acid removed. The increase in platelet-associated IgG was 0.112 (median, range 0.007 to 0.309) fg/platelet (n = 25, p <0.001) after 0.79 (median, range 0.00 to 6.70) nmol sialic acid/108 platelets was removed (p <0.001). There was an exponential correlation between the shortening of mean platelet life span after the removal of sialic acid and the increase in platelet-associated IgG. The results suggest that platelet membrane sialic acid influences ageing of circulating platelets, and that the loss of sialic acid may have exposed a senescent cell antigen that binds IgG on the platelet membrane. The antibody-antigen complex may then provide a signal to the macrophages that the platelet is old, and can be phagocytosed and destroyed.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Lena Dalal ◽  
Abdul Wahab Allaf ◽  
Hind El-Zein

AbstractSelf-nanoemulsifying drug delivery systems (SNEDDS) were used to enhance the dissolution rate of furosemide as a model for class IV drugs and the system was solidified into liquisolid tablets. SNEDDS of furosemide contained 10% Castor oil, 60% Cremophor EL, and 30% PEG 400. The mean droplets size was 17.9 ± 4.5 nm. The theoretical model was used to calculate the amounts of the carrier (Avicel PH101) and coating materials (Aerosil 200) to prepare liquisolid powder. Carrier/coating materials ratio of 5/1 was used and Ludipress was added to the solid system, thus tablets with hardness of 45 ± 2 N were obtained. Liquisolid tablets showed 2-folds increase in drug release as compared to the generic tablets after 60 min in HCl 0.1 N using USP apparatus-II. Furosemide loaded SNEDDS tablets have great prospects for further in vivo studies, and the theoretical model is useful for calculating the adequate amounts of adsorbents required to solidify these systems.


2021 ◽  
Vol 30 ◽  
pp. 096368972097873
Author(s):  
Jing Li ◽  
Youming Zhu ◽  
Na Li ◽  
Tao Wu ◽  
Xianyu Zheng ◽  
...  

The lack of vasculogenesis often hampers the survivability and integration of newly engineered tissue grafts within the host. Autologous endothelial cells (ECs) are an ideal cell source for neovascularization, but they are limited by their scarcity, lack of proliferative capacity, and donor site morbidity upon isolation. The objective of this study was to determine whether differentiation of human dental pulp stem cells (DPSCs) into the endothelial lineage can be enhanced by recombinant ETV2 overexpression. DPSCs were extracted from fresh dental pulp tissues. ETV2 overexpression in DPSCs was achieved by lentiviral infection and cellular morphological changes were evaluated. The mRNA and protein expression levels of endothelial-specific markers were assessed through quantitative real-time polymerase chain reaction, western blot, immunofluorescence staining, and flow cytometry. The tube formation assay and Matrigel plug assay were also performed to evaluate the angiogenic potential of the ETV2-transduced cells in vitro and in vivo, respectively. Additionally, proteomic analysis was performed to analyze global changes in protein expression following ETV2 overexpression. After lentiviral infection, ETV2-overexpressing DPSCs showed endothelial-like morphology. Compared with control DPSCs, significantly higher mRNA and protein expression levels of endothelial-specific genes, including CD31, VE-Cadherin, VEGFR1, and VEGFR2, were detected in ETV2-overexpressing DPSCs. Moreover, ETV2 overexpression enhanced capillary-like tube formation on Matrigel in vitro, as well as neovascularization in vivo. In addition, comparative proteomic profiling showed that ETV2 overexpression upregulated the expression of vascular endothelial growth factor (VEGF) receptors, which was indicative of increased VEGF signaling. Taken together, our results indicate that ETV2 overexpression significantly enhanced the endothelial differentiation of DPSCs. Thus, this study shows that DPSCs can be a promising candidate cell source for tissue engineering applications.


2021 ◽  
Vol 22 (5) ◽  
pp. 2269
Author(s):  
Keiji Masuda ◽  
Xu Han ◽  
Hiroki Kato ◽  
Hiroshi Sato ◽  
Yu Zhang ◽  
...  

A subpopulation of mesenchymal stem cells, developmentally derived from multipotent neural crest cells that form multiple facial tissues, resides within the dental pulp of human teeth. These stem cells show high proliferative capacity in vitro and are multipotent, including adipogenic, myogenic, osteogenic, chondrogenic, and neurogenic potential. Teeth containing viable cells are harvested via minimally invasive procedures, based on various clinical diagnoses, but then usually discarded as medical waste, indicating the relatively low ethical considerations to reuse these cells for medical applications. Previous studies have demonstrated that stem cells derived from healthy subjects are an excellent source for cell-based medicine, tissue regeneration, and bioengineering. Furthermore, stem cells donated by patients affected by genetic disorders can serve as in vitro models of disease-specific genetic variants, indicating additional applications of these stem cells with high plasticity. This review discusses the benefits, limitations, and perspectives of patient-derived dental pulp stem cells as alternatives that may complement other excellent, yet incomplete stem cell models, such as induced pluripotent stem cells, together with our recent data.


2021 ◽  
Vol 14 (4) ◽  
pp. 294
Author(s):  
Eric G. Romanowski ◽  
Islam T. M. Hussein ◽  
Steven C. Cardinale ◽  
Michelle M. Butler ◽  
Lucas R. Morin ◽  
...  

Presently, there is no FDA- or EMA-approved antiviral for the treatment of human adenovirus (HAdV) ocular infections. This study determined the antiviral activity of filociclovir (FCV) against ocular HAdV isolates in vitro and in the Ad5/NZW rabbit ocular model. The 50% effective concentrations (EC50) of FCV and cidofovir (CDV) were determined for several ocular HAdV types using standard plaque reduction assays. Rabbits were topically inoculated in both eyes with HAdV5. On day 1, the rabbits were divided into four topical treatment groups: (1) 0.5% FCV 4x/day × 10 d; (2) 0.1% FCV 4x/day × 10 d; (3) 0.5% CDV 2x/day × 7 d; (4) vehicle 4x/day × 10 d. Eyes were cultured for virus on days 0, 1, 3, 4, 5, 7, 9, 11, and 14. The resulting viral eye titers were determined using standard plaque assays. The mean in vitro EC50 for FCV against tested HAdV types ranged from 0.50 to 4.68 µM, whereas those treated with CDV ranged from 0.49 to 30.3 µM. In vivo, compared to vehicle, 0.5% FCV, 0.1% FCV, and 0.5% CDV produced lower eye titers, fewer numbers of positive eye cultures, and shorter durations of eye infection. FCV demonstrated anti-adenovirus activity in vitro and in vivo.


2021 ◽  
Vol 132 (8) ◽  
pp. e82-e83
Author(s):  
Sivapriya Senthilkumar ◽  
Chaitra Venugopal ◽  
K. Shobha ◽  
Bindu M. Kutty ◽  
Anandh Dhanushkodi

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Satoko Kakino ◽  
Shinya Kushibiki ◽  
Azusa Yamada ◽  
Zenzo Miwa ◽  
Yuzo Takagi ◽  
...  

The applicability of arterial pulse oximetry to dental pulp was demonstrated using in vitro and in vivo measurements. First, porcine blood of known oxygen saturation (SO2) was circulated through extracted human upper incisors, while transmitted-light plethysmography was performed using three different visible wavelengths. From the light intensity waveforms measured in vitro, a parameter that is statistically correlated to SO2 was calculated using the pulsatile/nonpulsatile component ratios of two wavelengths for different SO2. Then, values were measured in vivo for living incisors, and the corresponding SO2 values were calculated using the results of in vitro measurements. The estimated SO2 values of the upper central incisors measured in vivo were from 71.0 to 92.7%. This study showed the potential to measure the oxygen saturation changes to identify the sign of pulpal inflammation.


Sign in / Sign up

Export Citation Format

Share Document