Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 4 de 4
Filter
Add more filters

Database
Language
Affiliation country
Publication year range
1.
J Reprod Dev ; 2024 Jul 12.
Article in English | MEDLINE | ID: mdl-39010149

ABSTRACT

Cryopreservation adversely affects embryo quality and viability in vitro.We investigated the effects of cryopreservation solutions supplemented with the antioxidant carnosine on frozen-thawed bovine embryo viability. Bovine blastocysts were produced in vitro and cryopreserved using slow freezing. The rates of re-expanded and hatched blastocysts in the 50 µg/ml carnosine-supplemented group at 4, 24, and 48 h after thawing were higher than those in the control (P< 0.05) group. In frozen-thawed embryos, cryopreservation solution supplemented with carnosine (50 µg/ml) significantly reduced reactive oxygen species (ROS) production(P < 0.05), decreased TUNEL-positive apoptotic cells (P< 0.05), and increased the mRNA expression of BCL2 (P< 0.05), an apoptosis suppressor gene. The expression of translocase of outer mitochondrial membrane 20 (TOMM20), which is involved in protein mitochondrial transport, in the carnosine (50 µg/ml)-treated embryos was significantly higher than that in the control group (P < 0.05). ATP production in frozen-thawed embryos in the 50 µg/ml carnosine-supplemented group was significantly higher than that in the control group (P< 0.05), however no significant difference in the total number of cells per embryo among the groups was observed. These results suggest that supplementing the cryopreservation solution with carnosine can improve the viability of frozen-thawed bovine embryos by reducing oxidative damage.

2.
Biosci Biotechnol Biochem ; 85(7): 1675-1685, 2021 Jun 24.
Article in English | MEDLINE | ID: mdl-33930112

ABSTRACT

The fungus Exophiala jeanselmei strain KUFI-6N produces a unique cycloalkanone monooxygenase (ExCAMO) that displays an uncommon substrate spectrum of Baeyer-Villiger oxidation of 4-10-membered ring ketones. In this study, we aimed to identify and sequence the gene encoding ExCAMO from KUFI-6N and overexpress the gene in Escherichia coli. We found that the primary structure of ExCAMO is most closely related to the cycloalkanone monooxygenase from Cylindrocarpon radicicola ATCC 11011, with 54.2% amino acid identity. ExCAMO was functionally expressed in E. coli and its substrate spectrum and kinetic parameters were investigated. Substrate profiling indicated that ExCAMO is unusual among known Baeyer-Villiger monooxygenases owing to its ability to accept a variety of substrates, including C4-C12 membered ring ketones. ExCAMO has high affinity and catalytic efficiency toward cycloalkanones, the highest being toward cyclohexanone. Five other genes encoding Baeyer-Villiger monooxygenases were also cloned and expressed in E. coli.


Subject(s)
Exophiala/enzymology , Mixed Function Oxygenases/genetics , Cloning, Molecular , Enzyme Stability , Escherichia coli/genetics , Kinetics , Mixed Function Oxygenases/chemistry , Mixed Function Oxygenases/metabolism , Molecular Weight , Substrate Specificity , Temperature
3.
Int J Comput Assist Radiol Surg ; 18(2): 227-246, 2023 Feb.
Article in English | MEDLINE | ID: mdl-36198998

ABSTRACT

PURPOSE: An inevitable feature of ultrasound-based diagnoses is that the quality of the ultrasound images produced depends directly on the skill of the physician operating the probe. This is because physicians have to constantly adjust the probe position to obtain a cross section of the target organ, which is constantly shifting due to patient respiratory motions. Therefore, we developed an ultrasound diagnostic robot that works in cooperation with a visual servo system based on deep learning that will help alleviate the burdens imposed on physicians. METHODS: Our newly developed robotic ultrasound diagnostic system consists of three robots: an organ tracking robot (OTR), a robotic bed, and a robotic supporting arm. Additionally, we used different image processing methods (YOLOv5s and BiSeNet V2) to detect the target kidney location, as well as to evaluate the appropriateness of the obtained ultrasound images (ResNet 50). Ultimately, the image processing results are transmitted to the OTR for use as motion commands. RESULTS: In our experiments, the highest effective tracking rate (0.749) was obtained by YOLOv5s with Kalman filtering, while the effective tracking rate was improved by about 37% in comparison with cases without such filtering. Additionally, the appropriateness probability of the ultrasound images obtained during the tracking process was also the highest and most stable. The second highest tracking efficiency value (0.694) was obtained by BiSeNet V2 with Kalman filtering and was a 75% improvement over the case without such filtering. CONCLUSION: While the most efficient tracking achieved is based on the combination of YOLOv5s and Kalman filtering, the combination of BiSeNet V2 and Kalman filtering was capable of detecting the kidney center of gravity closer to the kidney's actual motion state. Furthermore, this model could also measure the cross-sectional area, maximum diameter, and other detailed information of the target kidney, which meant it is more practical for use in actual diagnoses.


Subject(s)
Robotics , Humans , Ultrasonography/methods , Robotics/methods , Image Processing, Computer-Assisted/methods , Motion , Kidney/diagnostic imaging
4.
Int J Comput Assist Radiol Surg ; 17(1): 107-119, 2022 Jan.
Article in English | MEDLINE | ID: mdl-34802143

ABSTRACT

PURPOSE: Noise-free ultrasound images are essential for organ monitoring during regional ultrasound-guided therapy. When the affected area is located under the ribs, however, acoustic shadow is caused by the reflection of sound from hard tissues such as bone, and the image is output with missing information in this region. Therefore, in the present study, we attempt to complement the image in the missing area. METHODS: The overall flow of the complementation method to generate a shadow-free composite image is as follows. First, we constructed a binary classification method for the presence or absence of acoustic shadow on a phantom kidney based on a convolutional neural network. Second, we created a composite shadow-free image by searching for a suitable image from a time-series database and superimposing the corresponding area without shadow onto the missing area of the target image. In addition, we constructed and verified an automatic kidney mask generation method utilizing U-Net. RESULTS: The complementation accuracy for kidney tracking could be enhanced by template matching. Zero-mean normalized cross-correlation (ZNCC) values after complementation were higher than that of before complementation under four different data generation conditions: (i) changing the position of the bed of the robotic ultrasound diagnostic system in the translational direction, (ii) changing the probe angle in the translational direction, (iii) with the addition of rotational motion of the probe to condition (ii). Although there was large variation in the shape of the kidney contour in condition (iii), the proposed method improved the ZNCC value from 0.5437 to 0.5807. CONCLUSIONS: The effectiveness of the proposed method was demonstrated in phantom experiments. Verification of its effectiveness in real organs is necessary in future study.


Subject(s)
Algorithms , Neural Networks, Computer , Acoustics , Humans , Ultrasonography , Ultrasonography, Interventional
SELECTION OF CITATIONS
SEARCH DETAIL