animal experiment
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2022 ◽  
Author(s):  
Taeok Bae ◽  
Bohyun Jeong ◽  
Majid Ali Shah ◽  
Eunjung Roh ◽  
Kyeong Kyu Kim ◽  
...  

The Gram-positive pathogen Staphylococcus aureus is the only bacterium known to synthesize arginine from proline via the arginine-proline interconversion pathway, despite having genes for the well-conserved glutamate pathway. Since the proline-arginine interconversion pathway is repressed by CcpA-mediated carbon catabolite repression (CCR), CCR has been attributed to the arginine auxotrophy of S. aureus. Using ribose as a secondary carbon source, here, we demonstrate that S. aureus arginine auxotrophy is not due to CCR but due to the inadequate concentration of proline degradation product. Proline is degraded by proline dehydrogenase (PutA) into pyrroline-5-carboxylate (P5C). Although the PutA expression was fully induced by ribose, the P5C concentration remained insufficient to support arginine synthesis because P5C was constantly consumed by the P5C reductase ProC. When the P5C concentration was artificially increased by either PutA overexpression or proC-deletion, S. aureus could synthesize arginine from proline regardless of carbon source. In contrast, when the P5C concentration was reduced by overexpression of proC, it inhibited the growth of the ccpA-deletion mutant without arginine. Intriguingly, the ectopic expression of the glutamate pathway enzymes converted S. aureus into arginine prototroph. In an animal experiment, the arginine-proline interconversion pathway was not required for the survival of S. aureus. Based on these results, we concluded that S. aureus does not synthesize arginine from proline under physiological conditions. We also propose that arginine auxotrophy of S. aureus is not due to the CcpA-mediated CCR but due to the inactivity of the conserved glutamate pathway.


2022 ◽  
Vol 12 (1) ◽  
Author(s):  
Johannes Müller ◽  
Walter Plöchl ◽  
Paul Mühlbacher ◽  
Alexandra Graf ◽  
Anne-Margarethe Kramer ◽  
...  

AbstractA high number of trauma patients are under the influence of alcohol. Since many of them need immediate surgical procedures, it is imperative to be aware of the interaction of alcohol with general anesthesia. To counter challenges that arise from clinical studies, we designed an animal experiment in which 48 adult Wistar rats either received 1 g · kg−1 ethanol, 2 g · kg−1 ethanol or placebo via intraperitoneal application. Subsequently, they were anesthetized with an individual concentration of sevoflurane. The minimum alveolar concentration (MAC) of the different groups was assessed using Dixon’s up-and-down design and isotonic regression methods. The bootstrap estimate of the MAC of sevoflurane in the placebo group was 2.24 vol% (95% CI 1.97–2.94 vol%). In the low dose ethanol group, the bootstrap estimate was 1.65 vol% (95% CI 1.40–1.98 vol%), and in the high dose ethanol group, it was 1.08 vol% (95% CI 0.73–1.42 vol%). We therefore report that intraperitoneal application of 1 g · kg−1 or 2 g · kg−1 ethanol both resulted in a significant reduction of the MAC of sevoflurane in adult Wistar rats: by 26.3% and 51.8% respectively as compared to placebo.


Animals ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 92
Author(s):  
Claire D. Lewis ◽  
Leah C. Marett ◽  
Bill Malcolm ◽  
S. Richard O. Williams ◽  
Tori C. Milner ◽  
...  

Ex ante economic analysis can be used to establish the production threshold for a proposed experimental diet to be as profitable as the control treatment. This study reports (1) a pre-experimental economic analysis to estimate the milk production thresholds for an experiment where dietary supplements were fed to dairy cows experiencing a heat challenge, and (2) comparison of these thresholds to the milk production results of the subsequent animal experiment. The pre-experimental thresholds equated to a 1% increase in milk production for the betaine supplement, 9% increase for the fat supplement, and 11% increase for fat and betaine in combination, to achieve the same contribution to farm profit as the control diet. For the post-experimental comparison, previously modelled climate predictions were used to extrapolate the milk production results from the animal experiment over the annual hot-weather period for the dairying region in northern Victoria, Australia. Supplementing diets with fat or betaine had the potential to produce enough extra milk to exceed the production thresholds, making either supplement a profitable alternative to feeding the control diet during the hot-weather period. Feeding fat and betaine in combination failed to result in the extra milk required to justify the additional cost when compared to the control diet.


2021 ◽  
Vol 20 (4) ◽  
pp. 147-150
Author(s):  
Eun Hye Oh ◽  
Hyun-Sung Kim ◽  
Jae-Hwan Choi

The flocculus plays a crucial role in control of eye movements. Based on animal experiment, it is suggested that the flocculus is important for governing vestibuleocular reflexes. In humans, an isolated floccular lesion is extremely rare. We report oculomotor abnormalities in a patient with unilateral infarction of the flocculus, and compare our results with those of previously reported patients with floccular lesion.


2021 ◽  
Vol 108 (Supplement_8) ◽  
Author(s):  
Hongshi Wang ◽  
Bernd Klosterhalfen ◽  
Andreas Müllen ◽  
Stephan Jockenhövel ◽  
Axel Dievernich ◽  
...  

Abstract Aim To researched the degradation resistance of PVDF mesh by comparing its morphological and chemical condition with PP mesh. Material and Methods PVDF and PP meshes analysed in this study were received from a previous animal experiment. To expose the surface of explanted meshes, a tissue removing method with protease was used and the result of this cleaning process was tested by X-ray Photoelectron Spectroscopy (XPS). The morphological condition of the mesh surface was compared using Scanning Electron Microscopy (SEM) and the chemical condition concerning degradation was analysed through Fourier Transform Infrared Spectroscopy (FTIR). The surface condition of PVDF mesh after 3-, 6-, 12- and 24-month implantation was illustrated and compared with two types of PP meshes. Results XPS revealed an absence of nitrogen, confirming the successful removal of tissue residues using protease. SEM results presented no notable morphological surface change of the PVDF mesh and progressive surface cracking processes over time of both types of PP meshes. FTIR spectra of the implanted PVDF meshes had no considerable difference from the spectrum of the pristine mesh, while FTIR spectra of both types of PP meshes had extra chemical functional groups increasing with implantation time, indicating progressive degradation. Conclusions PVDF mesh does not show signs of degradation up to 24 months after implantation while PP meshes progressively degrade with increasing time under the same conditions, which appears as worsening Environmental Stress Cracks. This study highlights the morphological and chemical stability of the PVDF mesh and demonstrates that the PVDF mesh is more resistant to degradation in comparison to the PP meshes.


PLoS ONE ◽  
2021 ◽  
Vol 16 (10) ◽  
pp. e0256519
Author(s):  
Dong Jun Oh ◽  
Ji Hyung Nam ◽  
Junseok Park ◽  
Youngbae Hwang ◽  
Yun Jeong Lim

Magnetically assisted capsule endoscopy (MACE) is a noninvasive procedure and can overcome passive capsule movement that limits gastric examination. MACE has been studied in many trials as an alternative to upper endoscopy. However, to increase diagnostic accuracy of various gastric lesions, MACE should be able to provide stereoscopic, clear images and to measure the size of a lesion. So, we conducted the animal experiment using a novel three-dimensional (3D) MACE and a new hand-held magnetic controller for gastric examination. The purpose of this study is to assess the performance and safety of 3D MACE and hand-held magnetic controller through the animal experiment. Subsequently, via the dedicated viewer, we evaluate whether 3D reconstruction images and clear images can be obtained and accurate lesion size can be measured. During real-time gastric examination, the maneuverability and visualization of 3D MACE were adequate. A polypoid mass lesion was incidentally observed at the lesser curvature side of the prepyloric antrum. The mass lesion was estimated to be 10.9 x 11.5 mm in the dedicated viewer, nearly the same size and shape as confirmed by upper endoscopy and postmortem examination. Also, 3D and clear images of the lesion were successfully reconstructed. This animal experiment demonstrates the accuracy and safety of 3D MACE. Further clinical studies are warranted to confirm the feasibility of 3D MACE for human gastric examination.


2021 ◽  
Author(s):  
Bing Zhao ◽  
Fei Chen ◽  
Qianqian Gao ◽  
Fan Mei ◽  
Li Zhao ◽  
...  

Abstract BackgroundThe formulation and implementation of a comprehensive search strategy is the basis for ensuring the quality of a systematic review (SR) and/or meta-analysis (MA). All published SRs/MAs of animal experiments were comprehensively identified, to evaluate how each search strategy was formulated, and how the search process and reporting were implemented, in order to represent a reference and provide suggestions for the future development of search procedures and reporting guidelines for SRs/MAs of animal experiments which should, ultimately, allow translation of the results of animal experiments into clinical practice.Methods and FindingsPubMed, OVID-Embase, Biosis Previews, CNKI, CBM, Wanfang Data, and VIP databases were searched to identify the SRs/MAs of medical-related animal experiments. The literature was independently screened and basic information extracted. The search characteristics (including search methods and their reporting) of each included study were analyzed in accordance with pre-established evaluation criteria. A total of 813 animal experiment SRs/MAs published in 503 different journals from 52 countries and regions were included. PubMed, Embase, and Medline were the three most commonly searched English-language databases for animal experiment SRs/MAs, although in 28.8% (234/813), fewer than 3 databases were searched. A supplementary search had been conducted in only half (52.2%, 424/813%) of the studies. In terms of search reporting, only 47.4% (385/813) reported search methods and 31.6% (243/813) described the search strategy. Only 4.8% (39/813) of the animal experiments SRs/MAs reported the qualifications of the search personnel.ConclusionsThe quality of search methods and reporting of the search process for published SRs/MAs of animal experiments are inadequate and substandard. Therefore, the search process should be standardized in future to improve efficiency and ensure the integrity and universality of the search, thereby allowing the development of SR/MA search strategies and reporting guidelines for animal experiments, and ultimately promote improvements in the quality of animal experiment SRs/MAs.


2021 ◽  
Vol 8 ◽  
Author(s):  
Feng Wu ◽  
Zhizhan Ni ◽  
Hongliang Diao ◽  
Chenshen Huang ◽  
Song Wang ◽  
...  

Background: Because of the challenge of jejunal closure recanalization, uncut Roux-en-Y reconstruction remains controversial. This study aimed to investigate the incidence of recanalization after uncut Roux-en-Y reconstruction in pigs and a small number of patients.Methods: Twenty miniature pigs were subjected to distal gastrectomy and uncut Roux-en-Y reconstruction using various rows of linear staplers to block the intestine. The pigs were sacrificed, and the incidence of recanalization was investigated 1 month after the operation. From December 2018 to June 2019, 10 patients with gastric cancer who had undergone elective laparoscopy-assisted distal gastrectomy and uncut Roux-en-Y reconstruction were included in this study. The primary study outcome was recanalization of the afferent limb, demonstrated by gastrointestinal radiography 1, 3, and 6 months after surgery. Various numbers of staple lines across the afferent jejunal limb were applied for closure: 2 staple lines in 2 pigs, 4 staple lines in 6 pigs, 6 staple lines in 8 pigs, and 8 staple lines in 4 pigs.Results: Complete recanalization was detected in all 20 pigs 1 month postoperatively. Recanalization was detected in five cases (50%) by gastrointestinal radiography. Among them, 1 case of recanalization was found in the 1st month after the operation, 2 cases were found in the 3rd month, and another 2 cases were found in the 6th month. Bile reflux was detected by endoscopy in 2 patients with recanalization.Conclusions: The occurrence of afferent limb recanalization after uncut Roux-en-Y reconstruction is high, and using additional staplers alone cannot decrease the incidence of recanalization. Based on our study, uncut Roux-en-Y reconstruction is not recommended.


2021 ◽  
Vol 31 (3) ◽  
pp. 31-55
Author(s):  
Jee-Yeong Won ◽  
Dayoung Han ◽  
Suhyun Nam ◽  
Bong-hun Kil ◽  
Dong-won Kim

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