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1.
Bioengineering (Basel) ; 10(7)2023 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-37508829

RESUMO

Furcation defects pose a significant challenge in the diagnosis and treatment planning of periodontal diseases. The accurate detection of furcation involvements (FI) on periapical radiographs (PAs) is crucial for the success of periodontal therapy. This research proposes a deep learning-based approach to furcation defect detection using convolutional neural networks (CNN) with an accuracy rate of 95%. This research has undergone a rigorous review by the Institutional Review Board (IRB) and has received accreditation under number 202002030B0C505. A dataset of 300 periapical radiographs of teeth with and without FI were collected and preprocessed to enhance the quality of the images. The efficient and innovative image masking technique used in this research better enhances the contrast between FI symptoms and other areas. Moreover, this technology highlights the region of interest (ROI) for the subsequent CNN models training with a combination of transfer learning and fine-tuning techniques. The proposed segmentation algorithm demonstrates exceptional performance with an overall accuracy up to 94.97%, surpassing other conventional methods. Moreover, in comparison with existing CNN technology for identifying dental problems, this research proposes an improved adaptive threshold preprocessing technique that produces clearer distinctions between teeth and interdental molars. The proposed model achieves impressive results in detecting FI with identification rates ranging from 92.96% to a remarkable 94.97%. These findings suggest that our deep learning approach holds significant potential for improving the accuracy and efficiency of dental diagnosis. Such AI-assisted dental diagnosis has the potential to improve periodontal diagnosis, treatment planning, and patient outcomes. This research demonstrates the feasibility and effectiveness of using deep learning algorithms for furcation defect detection on periapical radiographs and highlights the potential for AI-assisted dental diagnosis. With the improvement of dental abnormality detection, earlier intervention could be enabled and could ultimately lead to improved patient outcomes.

2.
Bioengineering (Basel) ; 10(6)2023 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-37370571

RESUMO

As the popularity of dental implants continues to grow at a rate of about 14% per year, so do the risks associated with the procedure. Complications such as sinusitis and nerve damage are not uncommon, and inadequate cleaning can lead to peri-implantitis around the implant, jeopardizing its stability and potentially necessitating retreatment. To address this issue, this research proposes a new system for evaluating the degree of periodontal damage around implants using Periapical film (PA). The system utilizes two Convolutional Neural Networks (CNN) models to accurately detect the location of the implant and assess the extent of damage caused by peri-implantitis. One of the CNN models is designed to determine the location of the implant in the PA with an accuracy of up to 89.31%, while the other model is responsible for assessing the degree of Peri-implantitis damage around the implant, achieving an accuracy of 90.45%. The system combines image cropping based on position information obtained from the first CNN with image enhancement techniques such as Histogram Equalization and Adaptive Histogram Equalization (AHE) to improve the visibility of the implant and gums. The result is a more accurate assessment of whether peri-implantitis has eroded to the first thread, a critical indicator of implant stability. To ensure the ethical and regulatory standards of our research, this proposal has been certified by the Institutional Review Board (IRB) under number 202102023B0C503. With no existing technology to evaluate Peri-implantitis damage around dental implants, this CNN-based system has the potential to revolutionize implant dentistry and improve patient outcomes.

3.
Sensors (Basel) ; 23(3)2023 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-36772613

RESUMO

It has always been a major issue for a hospital to acquire real-time information about a patient in emergency situations. Because of this, this research presents a novel high-compression-ratio and real-time-process image compression very-large-scale integration (VLSI) design for image sensors in the Internet of Things (IoT). The design consists of a YEF transform, color sampling, block truncation coding (BTC), threshold optimization, sub-sampling, prediction, quantization, and Golomb-Rice coding. By using machine learning, different BTC parameters are trained to achieve the optimal solution given the parameters. Two optimal reconstruction values and bitmaps for each 4 × 4 block are achieved. An image is divided into 4 × 4 blocks by BTC for numerical conversion and removing inter-pixel redundancy. The sub-sampling, prediction, and quantization steps are performed to reduce redundant information. Finally, the value with a high probability will be coded using Golomb-Rice coding. The proposed algorithm has a higher compression ratio than traditional BTC-based image compression algorithms. Moreover, this research also proposes a real-time image compression chip design based on low-complexity and pipelined architecture by using TSMC 0.18 µm CMOS technology. The operating frequency of the chip can achieve 100 MHz. The core area and the number of logic gates are 598,880 µm2 and 56.3 K, respectively. In addition, this design achieves 50 frames per second, which is suitable for real-time CMOS image sensor compression.

4.
Bioengineering (Basel) ; 9(12)2022 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-36550983

RESUMO

Apical Lesions, one of the most common oral diseases, can be effectively detected in daily dental examinations by a periapical radiograph (PA). In the current popular endodontic treatment, most dentists spend a lot of time manually marking the lesion area. In order to reduce the burden on dentists, this paper proposes a convolutional neural network (CNN)-based regional analysis model for spical lesions for periapical radiographs. In this study, the database was provided by dentists with more than three years of practical experience, meeting the criteria for clinical practical application. The contributions of this work are (1) an advanced adaptive threshold preprocessing technique for image segmentation, which can achieve an accuracy rate of more than 96%; (2) a better and more intuitive apical lesions symptom enhancement technique; and (3) a model for apical lesions detection with an accuracy as high as 96.21%. Compared with existing state-of-the-art technology, the proposed model has improved the accuracy by more than 5%. The proposed model has successfully improved the automatic diagnosis of apical lesions. With the help of automation, dentists can focus more on technical and medical diagnoses, such as treatment, tooth cleaning, or medical communication. This proposal has been certified by the Institutional Review Board (IRB) with the certification number 202002030B0.

5.
Insects ; 11(4)2020 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-32260140

RESUMO

Libraries are invaluable resources, documenting significant events that have shaped human history. However, the preservation of old books is severely threatened by insects commonly referred to as bookworms. In this study, a sample of infested books in a historic library in Taiwan was randomly selected and examined. An anobiid book-boring beetle, Falsogastrallus sauteri Pic, 1914 (Coleoptera: Ptinidae) was identified as the major bookworm species present. To facilitate its identification, both adults and larvae of F. sauteri are redescribed, with emphasis on its ultramorphological characteristics as revealed by scanning electronic microscopy. Furthermore, an undescribed parasitoid wasp in the Bethylidae was discovered in the frass, holes and tunnels created by F. sauteri. The new species, Cephalonomia formosiensis sp. nov. is described, and we suggest that it probably uses F. sauteri as host.

6.
Front Oncol ; 8: 681, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30705876

RESUMO

Human castration-resistant prostate cancer (CRPC) is a significant target of clinical research. The use of DNA-damaging agents has a long history in cancer chemotherapy but is limited by their toxicities. The combination with a safer drug can be a strategy in reducing dosage and toxicity while increasing anticancer activity in CRPC treatment. Phosphodiesterase type 5 (PDE5) inhibitors are used to treat erectile dysfunction through the selective inhibition of PDE5 that is responsible for cGMP degradation in the corpus cavernosum. Several studies have reported that PDE5 inhibitors display protective effect against doxorubicin-induced cardiotoxicity. The combinatory treatment of CRPC with doxorubicin and PDE5 inhibitors has been studied accordingly. The data demonstrated that sildenafil or vardenafil (two structure-related PDE5 inhibitors) but not tadalafil (structure-unrelated to sildenafil) sensitized doxorubicin-induced apoptosis in CRPC cells with deteriorating the down-regulation of anti-apoptotic Bcl-2 family members, including Bcl-xL and Mcl-1, and amplifying caspase activation. Homologous recombination (HR) and non-homologous end joining (NHEJ) DNA repair systems were inhibited in the apoptotic sensitization through detection of nuclear foci formation of Rad51 and DNA end-binding of Ku80. PDE5 knockdown to mimic the exposure to PDE5 inhibitors did not reproduce apoptotic sensitization, suggesting a PDE5-independent mechanism. Not only doxorubicin, sildenafil combined with other inhibitors of topoisomerase II but not topoisomerase I also triggered apoptotic sensitization. In conclusion, the data suggest that sildenafil and vardenafil induce PDE5-independent apoptotic sensitization to doxorubicin (or other topoisomerase II inhibitors) through impairment of both HR and NHEJ repair systems that are evident by a decrease of nuclear Rad51 levels and their foci formation in the nucleus, and an inhibition of Ku80 DNA end-binding capability. The combinatory treatment may enable an important strategy for anti-CRPC development.

7.
Oncotarget ; 8(57): 96668-96683, 2017 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-29228561

RESUMO

The use of peptides that target cancer cells and induce anticancer activities through various mechanisms is developing as a potential anticancer strategy. KUD983, an enantiomerically pure ß-dipeptide derivative, displays potent activity against hormone-refractory prostate cancer (HRPC) PC-3 and DU145 cells with submicromolar IC50. KUD983 induced G1 arrest of the cell cycle and subsequent apoptosis associated with down-regulation of several related proteins including cyclin D1, cyclin E and Cdk4, and the de-phosphorylation of RB. The levels of nuclear and total c-Myc protein, which could increase the expression of both cyclin D1 and cyclin E, were profoundly inhibited by KUD983. Furthermore, it inhibited PI3K/Akt and mTOR/p70S6K/4E-BP1 pathways, the key signaling in multiple cellular functions. The transient transfection of constitutively active myristylated Akt (myr-Akt) cDNA significantly rescued KUD983-induced caspase activation but did not blunt the inhibition of mTOR/p70S6K/4E-BP1 signaling cascade suggesting the presence of both Akt-dependent and -independent pathways. Moreover, KUD983-induced effect was enhanced with the down-regulation of anti-apoptotic Bcl-2 members (e.g., Bcl-2, and Mcl-1) and IAP family members (e.g., survivin). Notably, KUD983 induced autophagic cell death using confocal microscopic examination, tracking the level of conversion of LC3-I to LC3-II and flow cytometric detection of acidic vesicular organelles-positive cells. In conclusion, the data suggest that KUD983 is an anticancer ß-dipeptide against HRPCs through the inhibition of cell proliferation and induction of apoptotic and autophagic cell death. The suppression of signaling pathways regulated by c-Myc, PI3K/Akt and mTOR/p70S6K/4E-BP1 and the collaboration with down-regulation of Mcl-1 and survivin may explain KUD983-induced anti-HRPC mechanism.

8.
Oncotarget ; 7(47): 76995-77009, 2016 11 22.
Artigo em Inglês | MEDLINE | ID: mdl-27769069

RESUMO

A series of triazole-based small molecules that mimic FTY720-mediated anticancer activity but minimize its immunosuppressive effect have been produced. SPS-7 is the most effective derivative displaying higher activity than FTY720 in anti-proliferation against human hormone-refractory prostate cancer (HRPC). It induced G1 arrest of cell cycle and subsequent apoptosis in thymidine block-mediated synchronization model. The data were supported by a decrease of cyclin D1 expression, a dramatic increase of p21 expression and an associated decrease in RB phosphorylation. c-Myc overexpression replenished protein levels of cyclin D1 indicating that c-Myc was responsible for cell cycle regulation. PI3K/Akt/mTOR signaling pathways through p70S6K- and 4EBP1-mediated translational regulation are critical to cell proliferation and survival. SPS-7 significantly inhibited this translational pathway. Overexpression of Myr-Akt (constitutively active Akt) completely abolished SPS-7-induced inhibitory effect on mTOR/p70S6K/4EBP1 signaling and c-Myc protein expression, suggesting that PI3K/Akt serves as a key upstream regulator. SPS-7 also demonstrated substantial anti-tumor efficacy in an in vivo xenograft study using PC-3 mouse model. Notably, FTY720 but not SPS-7 induced a significant immunosuppressive effect as evidenced by depletion of marginal zone B cells, down-regulation of sphingosine-1-phosphate receptors and a decrease in peripheral blood lymphocytes. In conclusion, the data suggest that SPS-7 is not an immunosuppressant while induces anticancer effect against HRPC through inhibition of Akt/mTOR/p70S6K pathwaysthat down-regulate protein levels of both c-Myc and cyclin D1, leading to G1 arrest of cell cycle and subsequent apoptosis. The data also indicate the potential of SPS-7 since PI3K/Akt signalingis responsive for the genomic alterations in prostate cancer.


Assuntos
Antineoplásicos/administração & dosagem , Neoplasias de Próstata Resistentes à Castração/tratamento farmacológico , Bibliotecas de Moléculas Pequenas/administração & dosagem , Triazóis/administração & dosagem , Animais , Antineoplásicos/química , Antineoplásicos/farmacologia , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Cloridrato de Fingolimode/administração & dosagem , Cloridrato de Fingolimode/farmacologia , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Masculino , Camundongos , Fosfatidilinositol 3-Quinases/metabolismo , Neoplasias de Próstata Resistentes à Castração/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Proteínas Proto-Oncogênicas c-myc/metabolismo , Transdução de Sinais/efeitos dos fármacos , Bibliotecas de Moléculas Pequenas/química , Bibliotecas de Moléculas Pequenas/farmacologia , Serina-Treonina Quinases TOR/metabolismo , Triazóis/química , Triazóis/farmacologia , Ensaios Antitumorais Modelo de Xenoenxerto
9.
Naunyn Schmiedebergs Arch Pharmacol ; 388(11): 1223-36, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26246051

RESUMO

Zerumbone, a natural monocyclic sesquiterpene, is the main component of the tropical plant Zingiber zerumbet Smith. Zerumbone induced antiproliferative and apoptotic effects against PC-3 and DU-145, two human hormone-refractory prostate cancer (HRPC) cell lines. Zerumbone inhibited microtubule assembly and induced an increase of MPM-2 expression (specific recognition of mitotic proteins). It also caused an increase of phosphorylation of Bcl-2 and Bcl-xL, two key events in tubulin-binding effect, indicating tubulin-binding capability and mitotic arrest to zerumbone action. Furthermore, zerumbone induced several cellular effects distinct from tubulin-binding properties. First, zerumbone significantly increased, while paclitaxel (as a tubulin-binding control) decreased, Mcl-1 protein expression. Second, paclitaxel but not zerumbone induced Cdk1 activity. Third, zerumbone other than paclitaxel induced Cdc25C downregulation. The data suggest that, in addition to targeting tubulin/microtubule, zerumbone may act on other targets for signaling transduction. Zerumbone induced mitochondrial damage and endoplasmic reticulum (ER) stress as evidenced by the loss of mitochondrial membrane potential and upregulation of GRP-78 and CHOP/GADD153 expression. Zerumbone induced an increase of intracellular Ca(2+) levels, a crosstalk marker between ER stress and mitochondrial insult, associated with the formation of active calpain I fragment. It induced apoptosis through a caspase-dependent way and caused autophagy as evidenced by dramatic LC3-II formation. In summary, the data suggest that zerumbone is a multiple targeting compound that inhibits tubulin assembly and induces a crosstalk between ER stress and mitochondrial insult, leading to apoptosis and autophagy in HRPCs.


Assuntos
Neoplasias de Próstata Resistentes à Castração/metabolismo , Sesquiterpenos/farmacologia , Apoptose/efeitos dos fármacos , Proteínas Reguladoras de Apoptose/metabolismo , Autofagia/efeitos dos fármacos , Cálcio/metabolismo , Ciclo Celular/efeitos dos fármacos , Proteínas de Ciclo Celular/metabolismo , Linhagem Celular Tumoral , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Zingiber officinale , Humanos , Masculino , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Tubulina (Proteína)/metabolismo
10.
Mol Cancer Ther ; 4(8): 1277-85, 2005 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16093444

RESUMO

Pristimerin, a naturally occurring triterpenoid, has been shown to cause cytotoxicity in several cancer cell lines. However, the mechanism for the cytotoxic effect of pristimerin was never explored. In the present study, human breast cancer MDA-MB-231 cells treated with pristimerin (1 and 3 micromol/L) showed rapid induction of apoptosis, as indicated by caspase activation, DNA fragmentation, and morphologic changes. Pretreatment of a pan-caspase inhibitor benzyloxycarbonyl-Val-Ala-Asp-fluoromethyl ketone (z-VAD-fmk) completely prevented pristimerin-induced apoptosis. Treatment of tumor cells with pristimerin resulted in a rapid release of cytochrome c from mitochondria, which preceded caspase activation and the decrease of mitochondrial membrane potential. In addition, neither benzyloxycarbonyl-Val-Ala-Asp-fluoromethyl ketone nor permeability transition pore inhibitor cyclosporin A markedly prevented pristimerin-induced mitochondrial cytochrome c release. Pristimerin did not significantly alter the protein level of Bcl-2 family members (Bcl-2, Bcl-X(L), and Bax), nor did it induce Bax translocation. Moreover, Bcl-2 overexpression fails to prevent pristimerin-induced apoptosis. The generation of reactive oxygen species in MDA-MB-231 cells was also not affected by pristimerin. In a cell-free system, pristimerin induced cytochrome c release from isolated mitochondria. Taken together, these results suggested that pristimerin is a novel mitochondria-targeted compound and may be further evaluated as a chemotherapeutic agent for human cancer.


Assuntos
Antineoplásicos/uso terapêutico , Apoptose , Neoplasias da Mama/tratamento farmacológico , Caspases/metabolismo , Mitocôndrias/efeitos dos fármacos , Triterpenos/uso terapêutico , Clorometilcetonas de Aminoácidos/farmacologia , Antineoplásicos/farmacologia , Neoplasias da Mama/enzimologia , Inibidores de Caspase , Citocromos c/metabolismo , Feminino , Humanos , Membranas Intracelulares/efeitos dos fármacos , Membranas Intracelulares/metabolismo , Potenciais da Membrana/efeitos dos fármacos , Triterpenos Pentacíclicos , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Triterpenos/farmacologia , Células Tumorais Cultivadas
11.
Inorg Chem ; 36(17): 3609-3615, 1997 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-11670051

RESUMO

The X-ray structure of bis(pyrrolidinecarbodithioato)lead(II), Pb(II)(pdtc)(2), C(10)H(16)N(2)S(4)Pb, shows the metal to be on a crystallographic 2-fold axis. The primary Pb-S bonds are equal, 2.89 Å; this is a unique feature of this compound compared to other Pb(II) dithiocarbamate structures. The crystal structure consists of polymeric Pb(pdtc)(2) units stacked along the c axis in two antiparallel columns; successive Pb(pdtc)(2) units are staggered. There are weaker Pb-S bonding interactions with the unit above (secondary Pb-S bonds) such that the coordination polyhedron formed by the eight S atoms bound to the Pb atom is a distorted square antiprism. Successive antiprisms share the pyramidal base, and the Pb.Pb distance between neighboring Pb(pdtc)(2) units is 3.886(1) Å. We analyze the structures of other PbS(4) compounds and find that the Pb lone pair is important in defining their geometry. The large variety of Pb configurations results from peripheral changes in the ligand. This is due to a compromise between the efficient use of space in the crystal and the tendency of lead to have different coordination numbers. These configurations can be described by a pathway of conformational interconversion from a 4-sided pyramidal geometry to an octahedral system. The title compound crystallizes in the orthorhombic space group Pccn with z = 4; cell constants are a = 13.839(14) Å, b = 14.058(16) Å, c = 7.763(6) Å.

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