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1.
Zootaxa ; 4859(3): zootaxa.4859.3.5, 2020 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-33056190

RESUMO

Based on a well-preserved specimen from Eocene Baltic amber, Groehnaltica batophiloides gen. nov. and sp. nov. (Coleoptera: Chrysomelidae: Galerucinae: Alticini) is described and illustrated using X-ray micro-computed tomography (µCT). The new monotypic genus is compared with fossil and extant flea-beetle genera. In the extant Eurasian fauna Groehnaltica shows most similarity to Batophila Foudras, 1859. However, it is also similiar to a Palaeotropical group of genera, including Bikasha Maulik, 1931, and Lanka Maulik, 1926. Groehnaltica batophiloides is the tenth member of Alticini to be described from Baltic amber, adding to our understanding of the evolutionary history of this diverse group of beetles.


Assuntos
Besouros , Sifonápteros , Âmbar , Animais , Países Bálticos , Microtomografia por Raio-X
2.
Zootaxa ; 4768(3): zootaxa.4768.3.7, 2020 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-33055651

RESUMO

A new species of Mycetophagidae belonging to the genus Litargus, namely L. (Litargosomus) dantiscensis Alekseev, Kupryjanowicz et Bukejs sp. nov., is described and figured from Eocene Baltic amber using X-ray micro-computed tomography (µCT). Three additional specimens of a mycetophagid beetle that is rather common in Baltic amber, Crowsonium succinium Abdullah, are also reported. Prototoma striata Heer, which was originally placed in Mycetophagidae, is discussed based on its original description and illustration: it is proposed that the position incertae sedis within Coleoptera be given to this Early Jurassic fossil. Consequently, the records of Mycetophagidae from Eocene European amber should be considered the earliest occurrence of the family known to date.


Assuntos
Âmbar , Besouros , Animais , Países Bálticos , Fósseis , Microtomografia por Raio-X
3.
Zootaxa ; 4768(3): zootaxa.4768.3.10, 2020 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-33055654

RESUMO

Based on a single well-preserved specimen from Eocene Baltic amber, a new tenebrionid beetle Neomida groehni Nabozhenko et Bukejs sp. nov. (Diaperinae: Diaperini) is described and illustrated using phase-contrast X-ray microtomography. This oldest representative of the genus differs from all known extant and extinct congeners by the dorsally very weakly convex pronotum with undulate lateral margins (while other Neomida have a pronotum that is strongly convex along its transverse axis, with evenly rounded lateral margins); distinct, right posterior angles of pronotum; and elevated sutural area of the elytra.


Assuntos
Âmbar , Besouros , Animais , Países Bálticos , Fósseis , Microtomografia por Raio-X
4.
Shanghai Kou Qiang Yi Xue ; 29(4): 380-385, 2020 Aug.
Artigo em Chinês | MEDLINE | ID: mdl-33089286

RESUMO

PURPOSE: To investigate the effect of testosterone level on inflammatory bone resorption in periodontitis with mice. METHODS: Forty-eight SD mice were randomly divided into unligated group, sham operation group, castration group, castration + testosterone group, 12 mice in each group. At 6 weeks after ligation, serum testosterone levels were measured, and alveolar bone loss (ABL) and alveolar bone absorption area were compared by hematoxylin - eosin staining and methylene blue staining. The expression of inflammatory cytokine messenger RNA(mRNA) in gingival tissue was measured by real-time fluorescence quantitative PCR. SPSS 20.0 software package was used to analyze the data. RESULTS: Serum testosterone level among four groups was the highest in the unligated group, followed by castration + testosterone group, sham operation group and castration group, with significant difference(P<0.05). The ABL of the castration + testosterone group was significantly larger than that of the unligated group, the sham operation group and the castration group(P<0.05). The ABL of the castration group was significantly smaller than that of the sham operation group (P<0.05). The alveolar bone resorption area of the castration + testosterone group was significantly larger than that of the unligated group, the sham operation group and the castration group(P<0.05). The alveolar bone resorption area of the castration group was significantly smaller than that of the sham operation group (P<0.05). Interleukin-1ß (IL-1ß) mRNA, interleukin-6(IL-6) mRNA and tumor necrosis factor-α(TNF-α) mRNA levels in gingival tissues of sham operation group, castration group and castration + testosterone group were significantly higher than the unligated group. The levels of interleukin-10(IL-10) mRNA in gingival tissues of sham operation group, castration group and castration + testosterone group were significantly lower than those in unligated group(P<0.05). The level of IL-1ß mRNA in gingival tissues among four groups was the the highest in the unligated group, followed by castration + testosterone group, sham operation group and castration group, with significant difference (P<0.05). Serum testosterone levels were positively correlated with ABL, alveolar bone resorption area, and IL-1ß (P<0.05). CONCLUSIONS: Periodontitis with mice have decreased testosterone levels, and long-term testosterone depletion can reduce inflammatory bone resorption in alveolar bone, which may be achieved by reducing the level of IL-1ß, indicating that reduction of the level of testosterone in periodontitis patients may be a new treatment target for alveolar bone resorption.


Assuntos
Perda do Osso Alveolar , Periodontite , Animais , Citocinas , Humanos , Camundongos , Testosterona , Microtomografia por Raio-X
5.
Zhonghua Kou Qiang Yi Xue Za Zhi ; 55(10): 765-771, 2020 Oct 09.
Artigo em Chinês | MEDLINE | ID: mdl-33045789

RESUMO

Objective: To analyze the anatomical morphological characteristics of the trabecular bone of human mandibular condyle by observing the distribution of volume of interests (VOI). Methods: The micro-CT images of a right condyle specimen of a 61-year-old adult male was analyzed in this study. The cylindrical VOI with both diameter and height of 2 mm were arranged, according to a certain pattern, as many as possible at various levels within the trabecular bone of the condyle. Each VOI had no intersection area. The selected VOI were divided into 5 parts: medial part, middle part, lateral part, anterior part and posterior part, with 6 layers from top to bottom. And the distribution of the overall anatomical morphological characteristics of three-dimensional (3D) images of the trabecular bone of the condyle was analyzed by using seven morphological parameters of each VOI, i.e. bone mineral density (BMD), bone volume/total volume (BV/TV), bone surface area/bone volume (BS/BV), trabecular thickness (Tb.Th), trabecular bone number (Tb.N), trabecular spacing (Tb.Sp) and trabecular bone pattern factor (Tb.Pf). Results: In the present study, totally 34 VOI were selected from the condyle specimen.The morphological distribution of the VOI was uneven in the 3D structure of the trabecular bone of the human condyle. BMD, BV/TV, Tb.N and Tb.Th were much higher at the middle part, while showed the smallest at the medial part. The anterior part demonstrated much higher parameters than the posterior part at the first, second, fifth and sixth layers, respectively, however, the posterior part showed much higher parameters than the anterior part at the third and fourth layers, respectively. The BMD was much higher at the first [(332.66±97.11) mg/cm3] and sixth [(255.79±45.68) mg/cm3] layers, while the lowest at the second layer [(255.79±41.06) mg/cm3]. The BV/TV and Tb.N were much higher at the first layer, with the lowest at the fifth layer. The Tb.Th at the first layer [(0.11±0.03) mm] was much higher than the others, which were similarly lower. The BS/BV, Tb.Sp and Tb.Pf were lower at the first layer and much higher at the medial and lateral parts, while were lower at the middle and anterior parts. The posterior part demonstrated much higher BS/BV, Tb.Sp and Tb.Pf than the anterior part at the first, fifth and sixth layers, respectively. However, the anterior part showed much higher scores than the posterior part at the third and fourth layers, respectively. The ANOVA results showed that the 7 morphological parameters of VOI were not statistically significant amongst the 6 layers (P>0.05). However, the 6 out of the 7 parameters, i.e. BV/TV, BS/BV, Tb.Th, Tb.N, Tb.Sp and Tb.Pf, were statistically significant amongst the five parts (P<0.05), while the only parameter of BMD was not statistically significant (P>0.05). Conclusions: The anatomical distribution characteristics of the trabecular bone of condyle were analyzed by using 3D imaging measurement based on the VOI. The results showed uneven distributions and indicated that the method of dividing the trabecular bone of mandibular condyle into VOI sets, which accorded with its specific anatomical characteristics, was feasible for further reference.


Assuntos
Densidade Óssea , Imageamento Tridimensional , Adulto , Humanos , Masculino , Côndilo Mandibular/diagnóstico por imagem , Pessoa de Meia-Idade , Microtomografia por Raio-X
6.
Beijing Da Xue Xue Bao Yi Xue Ban ; 52(5): 952-958, 2020 Oct 18.
Artigo em Chinês | MEDLINE | ID: mdl-33047736

RESUMO

OBJECTIVE: To prepare and evaluate the basic properties in vitro of a novel small intestinal submucosa (SIS) sponge, and to describe the bone formation ability of the SIS sponge in vivo. METHODS: The SIS sponge was prepared by freeze-drying method. To evaluate the physicochemical properties of the sponge, electron microscope observation, porosity test, water absorption ability and mechanical property were conducted in vitro. The cytotoxicity of the SIS sponge was performed by cell counting kit-8 method. In vivo experiments, eighteen extraction sockets of premolar of three Beagle dogs were randomly divided into three groups: SIS sponge group (SIS sponge), positive control group (Bio-Oss granules and Bio-Gide membrane) and control group(no treatment). The animals were sacrificed 4 weeks and 12 weeks after operation, and micro computed tomography (Micro-CT) was applied to measure the bone volume fraction (BV/TV) and bone mineralized density (BMD). The data were analyzed with one-way ANOVA. RESULTS: The average pore diameter of the SIS sponge was (194.90±30.39) µm, the porosity was 92.31%±0.24%, the water absorption rate was 771.50%±40.90%, and the compressive elastic modulus was (2.20±0.19) kPa. There was no significant difference in cell proliferation ability between SIS sponge and control group (P>0.05). Micro-CT quantitative results showed that BV/TV of SIS sponge group (52.81%±3.21%) and positive control group (58.30%±9.36%) were significantly higher than that of control group (38.65%±4.80%) 4 weeks after operation (P < 0.05). The BMD of SIS sponge group [(887.09±61.02) mg/cm3], positive control group [(952.05±132.78) mg/cm3] and control group [(879.29±74.27) mg/cm3] showed no statistical difference 4 weeks after operation (P>0.05). The BV/TV of positive control group (60.57%± 6.56%) was significantly higher than that of SIS sponge group (47.89%±3.59%) and control group (42.99%±2.54%) 12 weeks after operation (P < 0.05). BMD of SIS sponge group [(1047±89.95) mg/cm3] and positive control group [(1101.37±98.85) mg/cm3] were significantly higher than that of control group [(890.36±79.79) mg/cm3] 12 weeks after operation (P < 0.05). CONCLUSION: The SIS sponge has satisfying physicochemical properties and biocompatibility. The SIS sponge significantly increased bone volume fraction in the early stage of bone formation (4 weeks) and bone mineralized density in the late stage of bone formation (12 weeks).


Assuntos
Osteogênese , Animais , Cães , Microtomografia por Raio-X
7.
Annu Int Conf IEEE Eng Med Biol Soc ; 2020: 4844-4847, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-33019075

RESUMO

With commercial space travel on the horizon, it is important to understand how the microgravity environment of space effects bone strength. The reduction in skeletal loading is known to cause a rapid loss in bone density. How this corresponds to losses of bone strength is not well known, especially when combined with the osteoporotic effects of aging. In this study, a mouse model of hind limb suspension (HLS) was used to simulate the effects of gravitational unloading. This was combined with soluble receptor activator of nuclear factor kappa beta ligand (sRANK-L), which simulates age related osteoporosis. The proximal region of the tibia in mouse legs was scanned in-vivo pre-treatment as well as at the conclusion of the study with high resolution micro computed tomography (µCT). Subject specific finite element (FE) models were constructed from these 3D images to assess bone strength by simulating mechanical loading on these bone microstructures. Parameters indicative of bone strength obtained from the FE models were bone volume, stiffness, structural efficiency, and the 10th and 90th percentile nodal Von-Mises Stresses. Additionally, a model sensitivity analysis was performed to assess how these parameters varied with changes in anatomic model height. In regards to FE stiffness, HLS resulted in a 31% decline, sRANK-L resulted in a 16.8% decline, and HLS combined with sRANK-L (HLS+sRANK-L) resulted in a 38.6% decline. One interesting finding is that HLS caused a reduction in both bone stiffness and bone structural efficiency, while sRANK-L did not cause changes in bone structural efficiency, suggesting the importance of skeletal loading for maintaining bone health. In addition, sRANK-L combined with HLS caused an additional decline in bone stiffness, but did not further alter bone structural efficiency. In conclusion, this study shows that depending on the cause of osteoporosis, bone strength changes are not necessarily proportional to bone density changes. Thus, it is important to develop new clinical bone assessments beyond the current bone density measurement.Clinical Relevance- These parameters are associated with the microstructural mechanics of bone, and understanding how strength is decreased on a structural level may lead to the development of in-vivo bone strength testing clinically.


Assuntos
Osso e Ossos , Elevação dos Membros Posteriores , Animais , Análise de Elementos Finitos , Camundongos , Modelos Anatômicos , Microtomografia por Raio-X
8.
Annu Int Conf IEEE Eng Med Biol Soc ; 2020: 1970-1975, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-33018389

RESUMO

Local drug delivery to the inner ear via micropump implants has the potential to be much more effective than oral drug delivery for treating patients with sensorineural hearing loss and to protect hearing from ototoxic insult due to noise exposure or cancer treatments. Designing micropumps to deliver appropriate concentrations of drugs to the necessary cochlear compartments is of paramount importance; however, directly measuring local drug concentrations over time throughout the cochlea is not possible. Recent approaches for indirectly quantifying local drug concentrations in animal models capture a series of magnetic resonance (MR) or micro computed tomography (µCT) images before and after infusion of a contrast agent into the cochlea. These approaches require accurately segmenting important cochlear components (scala tympani (ST), scala media (SM) and scala vestibuli (SV)) in each scan and ensuring that they are registered longitudinally across scans. In this paper, we focus on segmenting cochlear compartments from µCT volumes using V-Net, a convolutional neural network (CNN) architecture for 3-D segmentation. We show that by modifying the V-Net architecture to decrease the numbers of encoder and decoder blocks and to use dilated convolutions enables extracting local estimates of drug concentration that are comparable to those extracted using atlas-based segmentation (3.37%, 4.81%, and 19.65% average relative error in ST, SM, and SV), but in a fraction of the time. We also test the feasibility of training our network on a larger MRI dataset, and then using transfer learning to perform segmentation on a smaller number of µCT volumes, which would enable this technique to be used in the future to characterize drug delivery in the cochlea of larger mammals.


Assuntos
Cóclea , Orelha Interna , Animais , Cóclea/diagnóstico por imagem , Humanos , Camundongos , Rampa do Tímpano , Rampa do Vestíbulo , Microtomografia por Raio-X
9.
Annu Int Conf IEEE Eng Med Biol Soc ; 2020: 3432-3435, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-33018741

RESUMO

Many advances have been made with imaging of implanted neural devices; however, the ability to image whole nerve samples remains limited. Further, few imaging modalities are well suited for visualizing both whole devices in vivo and individual microelectrodes within a nerve. In this study, we used micro-computed tomography (micro-CT) to evaluate Wireless Floating Microelectrode Arrays (WMFAs) implanted in rat sciatic nerve at the level of whole devices and individual electrodes. WFMAs were also used to track selective recruitment of plantar flexion and dorsiflexion of the rear paw, which was achieved by each implanted device (n=6) during chronic implantation. Evoked limb motion was correlated to end-of-study assessments using micro-CT to visualize electrode locations within the fascicular structure of the sciatic nerve. Results of this study show that micro-CT imaging can provide valuable assessments of microelectrode arrays implanted in peripheral nerves for both whole devices visualized in vivo and individual electrodes visualized in whole nerve tissue samples.Clinical relevance- This work informs the use of micro-computed tomography as a tool for correlating neural device performance with physical attributes of the implant location.


Assuntos
Nervo Isquiático , Animais , Eletrodos Implantados , Microeletrodos , Ratos , Nervo Isquiático/diagnóstico por imagem , Microtomografia por Raio-X
10.
Zootaxa ; 4820(3): zootaxa.4820.3.8, 2020 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-33056061

RESUMO

Europoeurypus inglaeso gen. et sp. nov. is described from Eocene Baltic amber found on the Sambian Peninsula, Kaliningrad Region, Russia. Four additional specimens of mycterid beetles from collections of Baltic amber are reported. The secondary sexual characters and sexual dimorphism in the Eocene representatives of the genus Omineus Lewis, 1895 are documented for the first time and examined using X-ray micro-computed tomography (µCT). The studied Omineus male specimens were attributed to the fossil species Omineus febribilis Alekseev, Pollock Bukejs, 2019. A key to fossil species of Eurypinae from Eocene ambers is provided and several aspects of the biogeography of the subfamily Eurypinae are discussed.


Assuntos
Âmbar , Besouros , Animais , Europa (Continente) , Fósseis , Masculino , Caracteres Sexuais , Microtomografia por Raio-X
11.
Am J Dent ; 33(5): 251-257, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33017528

RESUMO

PURPOSE: To compare the stresses generated after the use of low elastic modulus polyetheretherketone (PEEK) as dental post and crown material with glass fiber post and metal supported ceramic crowns using finite element analysis. METHODS: First an image of a maxillary central incisor taken on micro-computed tomography (micro-CT) was uploaded to a computer program. Modeling was made of all the materials in the computer environment and 3-dimensional (3D) virtual models were obtained. Using two different post materials (glass fiber and PEEK post) and two different crown materials (metal supported ceramic and PEEK crown), the modeling of the maxillary central tooth was completed and a total of four groups were obtained. Finally, 135° and 100 N forces were applied from the midpoint of the palatal surface. RESULTS: The FEA analysis showed the use of PEEK as post material decreased the stress values in the post, post cement and composite core models and did not have any significant change in the dentin and crown cement models. The use of composite veneer with PEEK substructure as crown material reduced stress values in dentin, the post and composite core and increased stress values in both the post cement and the crown cement. CLINICAL SIGNIFICANCE: Since the elastic modulus of the PEEK material is very close to dentin tissue, finite element stress analysis, less stress formation in the tooth and post core restoration compared to other post systems was observed. In this context, PEEK post may reduce irreversible complications.


Assuntos
Técnica para Retentor Intrarradicular , Coroas , Análise de Elementos Finitos , Cetonas , Polietilenoglicóis , Microtomografia por Raio-X
12.
Int J Oral Maxillofac Implants ; 35(5): 879-887, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32991637

RESUMO

PURPOSE: To evaluate the influence on healing of the bony window elevated inward in the sinus cavity as a cortical bone graft. MATERIALS AND METHODS: Eighteen rabbits were included in the experiment. At the test sites (bony window), the antrostomy was prepared and the remaining bony window was elevated together with the sinus mucosa. At the control sites, the bony window was gently detached before the sinus mucosa elevation and discarded. The space obtained was grafted with deproteinized bovine bone mineral (DBBM). A collagen membrane was positioned on the antrostomy at both sides. The rabbits were euthanized after 2, 4, and 8 weeks in groups of six each. Histologic analyses in different regions of the elevated space were carried out, and a Wilcoxon test was used to estimate differences. Microcomputed tomography (microCT) analyses were also performed. RESULTS: After 2 weeks of healing, higher proportions of new bone were found in the test group compared with the control group due to the higher amount of bone formed in the region subjacent to the sinus mucosa. In this region, higher amounts of new bone were also found in the test group after 4 (P = .028) and 8 weeks of healing (P = .345). After 8 weeks of healing, the percentage of new bone was higher at the control sites compared with the test sites, with the proportions being 25.4% ± 3.2% and 21.3% ± 6.1%, respectively. In this period of evaluation, the bony window contributed with 20.1% ± 5.3% of vital bone in the test group. A fraction of 60.4% ± 10.8% of its surface was surrounded by new bone. In the microCT analysis, after 8 weeks of healing, fractions of 22.3% ± 1.6% and 22.2% ± 0.7% of bone were found in the test and control groups, respectively. CONCLUSION: The presence of the bony window positively influenced the healing in the elevated space, especially in the submucosa region. The bony window was vital and incorporated into newly formed bone.


Assuntos
Levantamento do Assoalho do Seio Maxilar , Animais , Transplante Ósseo , Bovinos , Osso Cortical/diagnóstico por imagem , Osso Cortical/cirurgia , Coelhos , Cicatrização , Microtomografia por Raio-X
13.
Proc Biol Sci ; 287(1935): 20201661, 2020 09 30.
Artigo em Inglês | MEDLINE | ID: mdl-32933445

RESUMO

The bivalved crustacean ostracods have the richest fossil record of any arthropod group and display complex reproductive strategies contributing to their evolutionary success. Sexual reproduction involving giant sperm, shared by three superfamilies of living ostracod crustaceans, is among the most fascinating behaviours. However, the origin and evolution of this reproductive mechanism has remained largely unexplored because fossil preservation of such features is extremely rare. Here, we report exceptionally preserved ostracods with soft parts (appendages and reproductive organs) in a single piece of mid-Cretaceous Kachin amber (approximately 100 Myr old). The ostracod assemblage is composed of 39 individuals. Thirty-one individuals belong to a new species and genus, Myanmarcypris hui gen. et sp. nov., exhibiting an ontogenetic sequence from juveniles to adults (male and female). Seven individuals are assigned to Thalassocypria sp. (Cypridoidea, Candonidae, Paracypridinae) and one to Sanyuania sp. (Cytheroidea, Loxoconchidae). Our micro-CT reconstruction provides direct evidence of the male clasper, sperm pumps (Zenker organs), hemipenes, eggs and female seminal receptacles with giant sperm. Our results reveal that the reproduction behavioural repertoire, which is associated with considerable morphological adaptations, has remained unchanged over at least 100 million years-a paramount example of evolutionary stasis. These results also double the age of the oldest unequivocal fossil animal sperm. This discovery highlights the capacity of amber to document invertebrate soft parts that are rarely recorded by other depositional environments.


Assuntos
Crustáceos/anatomia & histologia , Genitália Masculina , Espermatozoides , Âmbar , Animais , Artrópodes , Feminino , Fósseis , Genitália , Masculino , Reprodução , Microtomografia por Raio-X
14.
Nat Commun ; 11(1): 4527, 2020 09 10.
Artigo em Inglês | MEDLINE | ID: mdl-32913197

RESUMO

Evasion of programmed cell death represents a critical form of oncogene addiction in cancer cells. Understanding the molecular mechanisms underpinning cancer cell survival despite the oncogenic stress could provide a molecular basis for potential therapeutic interventions. Here we explore the role of pro-survival genes in cancer cell integrity during clonal evolution in non-small cell lung cancer (NSCLC). We identify gains of MCL-1 at high frequency in multiple independent NSCLC cohorts, occurring both clonally and subclonally. Clonal loss of functional TP53 is significantly associated with subclonal gains of MCL-1. In mice, tumour progression is delayed upon pharmacologic or genetic inhibition of MCL-1. These findings reveal that MCL-1 gains occur with high frequency in lung adenocarcinoma and can be targeted therapeutically.


Assuntos
Antineoplásicos/farmacologia , Carcinoma Pulmonar de Células não Pequenas/genética , Neoplasias Pulmonares/genética , Proteína de Sequência 1 de Leucemia de Células Mieloides/genética , Animais , Antineoplásicos/uso terapêutico , Apoptose/efeitos dos fármacos , Apoptose/genética , Carcinoma Pulmonar de Células não Pequenas/diagnóstico por imagem , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/patologia , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/genética , Evolução Clonal , Variações do Número de Cópias de DNA , Conjuntos de Dados como Assunto , Modelos Animais de Doenças , Progressão da Doença , Humanos , Pulmão/diagnóstico por imagem , Pulmão/patologia , Neoplasias Pulmonares/diagnóstico por imagem , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/patologia , Camundongos , Camundongos Transgênicos , Mutação , Proteína de Sequência 1 de Leucemia de Células Mieloides/antagonistas & inibidores , Cultura Primária de Células , Estudos Prospectivos , Proteínas Proto-Oncogênicas p21(ras)/genética , Pirimidinas/farmacologia , Pirimidinas/uso terapêutico , RNA-Seq , Estudos Retrospectivos , Esferoides Celulares , Tiofenos/farmacologia , Tiofenos/uso terapêutico , Carga Tumoral/efeitos dos fármacos , Carga Tumoral/genética , Proteína Supressora de Tumor p53/genética , Microtomografia por Raio-X
15.
Artigo em Inglês | MEDLINE | ID: mdl-32925994

RESUMO

The goal of the present study was to evaluate human histologic healing of dental implants with a unique triangular neck design that is narrower than the implant body. Four patients in need of full-mouth reconstruction were recruited and received several implants to support a full-arch prosthesis. In each patient, two additional customized reduced-diameter implants were placed, designated to be harvested after 6 months of submerged healing. The eight harvested implants were all placed in healed edentulous maxillary or mandibular ridges. These implants were Ø 3.5 × 8 mm in size, and the final osteotomy drill allowed for the creation of a gap up to 0.2 mm in size between the coronal aspect of the triangular implant neck and the surrounding bone. At the end of the healing period, the implants were retrieved with the surrounding bone. Microcomputed tomography (µCT) was performed before processing the biopsy samples for undecalcified histologic exampination. Bone-to-implant contact (BIC) was measured from the µCT data and from buccolingual/buccopalatal and mesiodistal central histologic sections. All implant gaps were filled by mature remodeled bone. The mean BICs of the BL/BP and MD sections were 64.45% ± 6.86% and 65.39% ± 10.44%, respectively, with no statistically significant difference. The mean 360-degree 3D BIC measured all over the implant surface was 68.58% ± 3.76%. The difference between the BIC measured on the µCT and on the histologic sections was not statistically significant. The positive histologic results of the study confirmed the efficacy of this uniquely designed dental implant.


Assuntos
Implantes Dentários , Osseointegração , Implantação Dentária Endo-Óssea , Planejamento de Prótese Dentária , Humanos , Mandíbula/cirurgia , Microtomografia por Raio-X
16.
Nat Commun ; 11(1): 4686, 2020 09 17.
Artigo em Inglês | MEDLINE | ID: mdl-32943633

RESUMO

Electrophysiology provides a direct readout of neuronal activity at a temporal precision only limited by the sampling rate. However, interrogating deep brain structures, implanting multiple targets or aiming at unusual angles still poses significant challenges for operators, and errors are only discovered by post-hoc histological reconstruction. Here, we propose a method combining the high-resolution information about bone landmarks provided by micro-CT scanning with the soft tissue contrast of the MRI, which allowed us to precisely localize electrodes and optic fibers in mice in vivo. This enables arbitrating the success of implantation directly after surgery with a precision comparable to gold standard histology. Adjustment of the recording depth with micro-drives or early termination of unsuccessful experiments saves many working hours, and fast 3-dimensional feedback helps surgeons avoid systematic errors. Increased aiming precision enables more precise targeting of small or deep brain nuclei and multiple targeting of specific cortical or hippocampal layers.


Assuntos
Encéfalo/diagnóstico por imagem , Eletrodos Implantados , Processamento de Imagem Assistida por Computador/métodos , Fibras Ópticas , Microtomografia por Raio-X/métodos , Animais , Comportamento Animal , Encéfalo/patologia , Mapeamento Encefálico , Hipocampo/diagnóstico por imagem , Hipocampo/patologia , Hipocampo/cirurgia , Técnicas Histológicas/métodos , Imagem por Ressonância Magnética/métodos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Modelos Animais , Silício , Técnicas Estereotáxicas
17.
PLoS One ; 15(9): e0237678, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32877422

RESUMO

Custom-made implants have recently gained attention in veterinary medicine because of their ability to properly fit animal bones having a wide variety of shapes and sizes. The effect of custom-made implants on bone soundness and the regeneration process is not yet clear. We fabricated a 3D printed Ti-6Al-4V custom-made bone plate that fits the shape of the dog radius, and placed it into the radius where an osteotomy had been made. The preferential orientation of the apatite c-axis contributes to the mechanical integrity of the bone and is a reliable measure of bone quality. We determined this parameter as well as the bone shape and bone mineral density (BMD). The bone portion which lies parallel to the bone plate exhibited bone resorption, decreased BMD, and significant degradation of apatite orientation, relative to the portion outside the plate, at 7 months after the operation. This demonstrates the presence of stress shielding in which applied stress is not transmitted to bone due to the insertion of a stiff bone plate. This reduced stress condition clearly influences the bone regeneration process. The apatite orientation in the regenerated site remained different even after 7 months of regeneration, indicating insufficient mechanical function in the regenerated portion. This is the first study in which the apatite orientation and BMD of the radius were evaluated under conditions of stress shielding in dogs. Our results suggest that assessment of bone repair by radiography can indicate the degree of restoration of BMD, but not the apatite orientation.


Assuntos
Apatitas/farmacologia , Placas Ósseas , Fixação Interna de Fraturas , Impressão Tridimensional , Fraturas do Rádio/cirurgia , Titânio/farmacologia , Animais , Densidade Óssea/efeitos dos fármacos , Cães , Feminino , Microtomografia por Raio-X
18.
PLoS One ; 15(9): e0236653, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32956411

RESUMO

Symbiosis can facilitate the development of specialized organs in the host body to maintain relationships with beneficial microorganisms. To understand the developmental and genetic mechanisms by which such organs develop, it is critical to first investigate the morphology and developmental timing of these structures during the onset of host development. We utilized micro-computed tomography (µCT) to describe the morphology and development of mycangia, a specialized organ, in the Asian ambrosia beetle species Euwallacea validus which maintains a mutualistic relationship with the Ascomycete fungus, Fusarium oligoseptatum. We scanned animals in larval, pupal and adult life stages and identified that mycangia develop during the late pupal stage. Here we reconcile preliminary evidence and provide additional morphological data for a second paired set of structures, including the superior, medial mycangia and an inferior, lateral pair of pouch-like structures, in both late-stage pupae and adult female beetles. Furthermore, we report the possible development of rudimentary, or partially developed pairs of medial mycangia in adult male beetles which has never been reported for any male Xyleborini. Our results illustrate the validity of µCT in observing soft tissues and the complex nature of mycangia morphology and development.


Assuntos
Besouros/crescimento & desenvolvimento , Besouros/ultraestrutura , Animais , Besouros/anatomia & histologia , Feminino , Larva/anatomia & histologia , Larva/crescimento & desenvolvimento , Larva/ultraestrutura , Masculino , Pupa/anatomia & histologia , Pupa/crescimento & desenvolvimento , Pupa/ultraestrutura , Caracteres Sexuais , Microtomografia por Raio-X
19.
Chin J Dent Res ; 23(3): 177-182, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32974617

RESUMO

OBJECTIVE: To investigate the role of microbiota in dentine formation and the characteristics of dental pulp stem cells (DPSCs) in mouse incisors. METHODS: The influence of microbiota on dentine was detected via microcomputed tomography (microCT), microhardness testing and haematoxylin-eosin (HE) staining in incisors from germ-free (GF), specific pathogen-free (SPF) and conventionalised (ConvD) mice. Cell Counting Kit-8 (CCK-8) assay, alizarin red staining and expression of dentine sialophosphoprotein (DSPP), alkaline phosphatase (ALP) and bone sialoprotein (BSP) via real-time polymerase chain reaction (PCR) were used to evaluate the biological characteristics of DPSCs derived from mice of different microbiota status. RESULTS: MicroCT showed that the incisors in the GF and ConvD groups had comparable dentine thickness to those in the SPF group. Microhardness testing showed a lower dentine hardness value in GF incisors compared to SPF, while HE staining showed that GF incisors exhibited thicker predentine than SPF incisors. There was no difference between the ConvD and SPF groups. DPSCs from GF mice showed no significant difference in proliferation rate to SPF and ConvD DPSCs. DPSCs from GF mice formed less mineral deposition and expressed lower levels of osteo-/odontogenic differentiation-related genes including ALP, BSP and DSPP than SPF and ConvD DPSCs. The absence of microbiota in GF mice resulted in a lower dentine hardness value, thicker predentine and impaired osteo-/odontogenic differentiation capacity. CONCLUSION: The absence of microbiota impaired the dentine mineralisation and osteo-/odontogenic differentiation abilities of DPSCs.


Assuntos
Polpa Dentária , Microbiota , Animais , Diferenciação Celular , Proliferação de Células , Células Cultivadas , Dentina , Camundongos , Células-Tronco , Microtomografia por Raio-X
20.
PLoS One ; 15(8): e0237043, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32750081

RESUMO

The aim of this study was to clarify the heights and spatial relationships of the facial muscles acting on the nasolabial fold (NLF) by dissection and three-dimensional microcomputed tomography for use in aesthetic treatments. This study used 56 specimens from 34 embalmed adult Korean. A reference line (RF) was set to imitate the NLF after removing the skin, from the superior point of the alar facial crease to the lateral point of the orbicularis oris muscle at the level of the corner of the mouth. The heights and spatial relationships of the facial muscles along the RF could be categorized into five main patterns. The dominant pattern was that the levator labii superioris alaeque nasi muscle (LLSAN), levator labii superioris muscle (LLS), zygomaticus minor muscle (Zmi), and zygomaticus major muscle (Zmj) were on the medial third, medial half, middle third, and lateral third of the RF, respectively. In micro-CT imaging, beneath the skin of the medial half of the NLF, the LLSAN and Zmi fibers inserted into the dermis of the NLF and adjacent to the NLF. Beneath the skin of the middle third of the NLF, the Zmi fibers were found before the muscle inserted into the dermis of the NLF and adjacent to the NLF. Beneath the skin of the lateral third of the NLF, the lateral margin of the orbicularis oris muscle and some Zmj fibers were found at the location of the NLF. The present study utilized dissections and micro-CT to reveal the general pattern and variations of heights and spatial relationships of the facial muscles passing beneath the NLF. These findings will be useful for understanding which muscles affect specific parts of NLFs with various contours, for reducing the NLF in aesthetic treatments, and for reconstructing the NLF in cases of facial paralysis.


Assuntos
Músculos Faciais/anatomia & histologia , Sulco Nasogeniano/anatomia & histologia , Cadáver , Dissecação , Feminino , Humanos , Masculino , República da Coreia , Microtomografia por Raio-X
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