Establishment and effect evaluation of an aortic dissection model induced by different doses of β-aminopropionitrile in rats

Vascular ◽  
2020 ◽  
pp. 170853812098405
Author(s):  
Xiaochai Lv ◽  
Yunnan Hu ◽  
Xiaodong Chen ◽  
Xingfeng Chen ◽  
Liangwan Chen ◽  
...  

Introduction Given the controversy regarding the appropriate dose of β-aminopropionitrile for induction of aortic dissection models in rats, the purpose of this study was to explore the most suitable concentration of β-aminopropionitrile to establish a high-incidence and low-mortality aortic dissection model. Methods Eighty three-week-old male Sprague-Dawley rats were equally divided into four groups: a control group, a 0.06% β-aminopropionitrile group, a 0.08% β-aminopropionitrile group and a 0.1% β-aminopropionitrile group. Initial experiments were performed on the control group, which was not treated with β-aminopropionitrile (and drank water freely), and the other three groups, which were given different concentrations of β-aminopropionitrile solution daily (0.06%, 0.08% and 0.1%). Subsequently, on the 40th day, osmotic minipumps administering 1 μg/kg per min angiotensin II (Ang II) were implanted subcutaneously into the β-aminopropionitrile groups, while the control group was continuously pumped with normal saline. The rats were euthanized 48 h after implantation. All rats that died before the expected end time of the experiment were autopsied immediately, and the aortas were dissected. The rats surviving at the end of the experiment were sacrificed by an overdose of sodium pentobarbital, and tissue samples were harvested for further analyses. Results The mean survival days were significantly different among the groups, with 39.1 ± 6.04 days in the 0.08% β-aminopropionitrile group and 32.7 ± 9.85 days in the 0.1% β-aminopropionitrile group ( P = 0.0178) at the end of the experiment. Compared with those in the 0.06% β-aminopropionitrile group, the rates of aortic dissection were significantly higher in the 0.08% β-aminopropionitrile group and the 0.1% β-aminopropionitrile group ( P = 0.0015 and P = 0.0005, respectively), while there was no significant difference between the 0.08% β-aminopropionitrile group and the 0.1% β-aminopropionitrile group ( P = 0.723) at 70% and 75%, respectively. However, the rupture rates were significantly different between the 0.08% β-aminopropionitrile group and the 0.1% β-aminopropionitrile group (55% versus 20%, P = 0.022). Hematoxylin-eosin staining of the aortic tissue sections of the β-aminopropionitrile group showed that red blood cells entered the pseudocavity in the vascular wall, while the vascular wall structure of the control group was intact. Compared with control rats, which were intact and free from fracture, β-aminopropionitrile-treated rats had fewer collagen fibers and exhibited fracture. Magnetic resonance imaging showed that the aortic intimae of the aortic dissection rats showed double lumens and intimal tears. Conclusions An aortic dissection model with a high incidence and low mortality was successfully and stably developed with 0.08% β-aminopropionitrile. This model will enable further studies investigating aortic dissection pathogenesis and drug therapy. Magnetic resonance imaging may be a reliable technique for imaging the aorta in rats.

2020 ◽  
Vol 2 (3) ◽  
pp. 9
Author(s):  
Eman A. A. Dabou ◽  
Yasmin F. M. AbdElazeem ◽  
Hend A. E. Elshenawie

Contents: Magnetic resonance imaging (MRI) is one of the medical diagnostic imaging techniques that can provoke or exaggerate anxiety in certain patients. It may sometimes lead to the cancelation of the MRI.   The lavender essential oil has a long historical anxiolytic benefit. Aim: This study aimed to examine the effect of lavender essential oil inhalation with a massage on anxiety level for patients undergoing closed magnetic resonance imaging. Methods: A quasi-experimental research (study/control group) was used to achieve the aim of this study. The study conducted at Magnetic Resonance Imaging Unit in Main University Hospital, Alexandria, Egypt. A convenient sample of 100 patients divided into the study and control group (50 patients for each). Two tools were used in the present study. Those were structured interview questionnaire that elicited the patients' sociodemographic characteristics, and State-Trait Anxiety Inventory to identify the patients' anxiety levels. Results: There were no statistically significant differences between both groups concerning the anxiety level before the MRI procedure (χ2=2.041, P = 0.495). While there were statistically significant differences between both groups concerning anxiety level post-MRI procedure and after receiving of interventions (χ2 =35.135, P=0.000), there was a highly statistically significant difference between anxiety level before and after receiving intervention in study group patients (t= 77.059, P=0.000). Conclusion: Patients undergoing a closed magnetic resonance imaging who inhaled and massaged their hands with Lavender essential oil exhibited a reduced level of anxiety compared to the control group and compared to their preintervention level. The study recommended using the lavender essential oil, which is an inexpensive and noninvasive intervention in reducing MRI anxiety or other anxiety-producing procedures.


2021 ◽  
Vol 13 (9) ◽  
pp. 1595-1602
Author(s):  
Yuli Wu ◽  
Junwei Song ◽  
Shengcui Liu ◽  
Xianglei Wei ◽  
Weiwei Chen

This study aimed to explore the application of super paramagnetic gold magnetic nanoparticles (Au-M-NPs) in the magnetic resonance imaging (MRI) images for targeted diagnosis and treatment of breast cancer. The reducibility of ethylene glycol to ferric chloride (FeCl3) was adopted to synthesize the Au-M-NPs by solvothermal method by taking acetic acid as the base source and trisodium citrate as the stabilizer. Besides, the synthesized Au-M-NPs were applied in the MRI images for targeted therapy of breast cancer. Patients from a blank group (group A), a control group (group B), and an experimental group (group C) received the traditional clinical diagnosis treatment, MRI diagnosis, and Au-M-NPs targeted therapy with MRI in turn. The results showed that the prepared Au-M-NPs were featured with small particle size and good dispersibility, and were monodispersive after surface modification. The intraoperative blood loss of patients from group A (115.3±9.33 mL) and group B (94.6±9.72 mL) was obviously higher than the loss of group C (68.4±8.7 mL) (P < 0.05). The drainage volume of patients from group B (162.4±12.3 mL) and group C (131.9±11.8 mL) decreased sharply after surgery compared with group A (193.7±11.8 mL), and that in group C was the lowest (P < 0.05). The proportion of local recurrence in patients from group B (12.3%) and group C (6.4%) dropped steeply in contrast to the proportion of group A (13.2%) (P < 0.05). The proportion of tumor metastasis in patients from group B (11.2%) and group C (8.4%) was greatly lower than that of group A (14.8%) (P < 0.05). In conclusion, the application of Au-M-NPs in the diagnosis and treatment of breast cancer with MRI could effectively reduce the incidence of intraoperative and postoperative adverse reactions.


2013 ◽  
Vol 26 (1) ◽  
pp. 3-17 ◽  
Author(s):  
Ş. Temel ◽  
H.D. Kekliğkoğlu ◽  
G. Vural ◽  
O. Deniz ◽  
K. Ercan

Multiple sclerosis is a chronic inflammatory demyelinating disease of the central nervous system. Diffusion tensor magnetic resonance imaging (DTI) can yield important information on the in vivo pathological processes affecting water diffusion. The aim of this study was to quantitatively define water diffusion in normal-appearing white matter (NAWM) distant from the plaque, in the plaque, and around the plaque, and to investigate the correlation of these changes with clinical disability. Conventional MRI and DTI scans were conducted in 30 patients with MS and 15 healthy individuals. Fractional anisotropy maps and visible diffusion coefficients were created and integrated with T2-weighted images. Regions of interest (ROIs) were placed on the plaques on the same side, white matter around the plaques and NAWM on the opposite side. Only the white matter of healthy individuals in the control group, and FA and ADC values were obtained for comparison. The highest FA and lowest ADC were detected in the control group at the periventricular region, cerebellar peduncle and at all ROIs irrespective of location. There was a significant difference in comparison to the control group at all ROIs in patients with MS (p < 0.001 for all comparisons). No significant correlation between diffusion parameters and expanded disability state scale (EDSS) scores was found in patients with MS. DTI may provide more accurate information on the damage due to the illness, compared to T2A sequences, but this damage may not be correlated with the clinical disability measured by EDSS score.


Author(s):  
Sydney M Nguyen ◽  
Gregory J Wiepz ◽  
Michele Schotzko ◽  
Heather A Simmons ◽  
Andres Mejia ◽  
...  

Abstract Ferumoxytol is a superparamagnetic iron oxide nanoparticle used off-label as an intravascular magnetic resonance imaging (MRI) contrast agent. Additionally, ferumoxytol-uptake by macrophages facilitates detection of inflammatory sites by MRI through ferumoxytol-induced image contrast changes. Therefore, ferumoxytol-enhanced MRI holds great potential for assessing vascular function and inflammatory response, critical to determine placental health in pregnancy. This study sought to assess the fetoplacental unit and selected maternal tissues, pregnancy outcomes, and fetal well-being after ferumoxytol administration. In initial developmental studies, seven pregnant rhesus macaques were imaged with or without ferumoxytol administration. Pregnancies went to term with vaginal delivery and infants showed normal growth rates compared to control animals born the same year that did not undergo MRI. To determine the impact of ferumoxytol on the maternal–fetal interface (MFI), fetal well-being, and pregnancy outcome, four pregnant rhesus macaques at ~100 gestational day underwent MRI before and after ferumoxytol administration. Collection of the fetoplacental unit and selected maternal tissues was performed 2–3 days following ferumoxytol administration. A control group that did not receive ferumoxytol or MRI was used for comparison. Iron levels in fetal and MFI tissues did not differ between groups, and there was no significant difference in tissue histopathology with or without exposure to ferumoxytol, and no effect on placental hormone secretion. Together, these results suggest that the use of ferumoxytol and MRI in pregnant rhesus macaques does not negatively impact the MFI and can be a valuable experimental tool in research with this important animal model.


2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Janne Pesonen ◽  
Michael Shacklock ◽  
Juha-Sampo Suomalainen ◽  
Lauri Karttunen ◽  
Jussi Mäki ◽  
...  

Abstract Background The straight leg raise test (SLR) is one of the most utilized and studied physical tests in patients with low back pain (LBP) for the detection of lumbar disc herniation (LDH), showing high sensitivity and heterogeneous or low specificity. The high incidence of asymptomatic ‘pathologic’ findings in the magnetic resonance imaging (MRI) scans may cause verification bias to these results. We studied an extended SLR (ESLR) by adding location-specific structural differentiation movements (hip internal rotation or ankle dorsiflexion) to the traditional SLR for it to better differentiate neural symptoms from musculoskeletal. Previously, the ESLR has shown almost perfect interrater reliability between examiners and ability to detect sciatic patients. In this study, we investigated whether a ’positive’ ESLR finding is associated with pathology seen on MRI. Methods Forty subjects comprised the study population, 20 in sciatic group and 20 in control group. The ESLR was performed ‘blinded’ to the subjects. After the ESLR, each subject’s lumbar MRI was evaluated. The MRIs were analyzed independently by 2 senior radiologists and a spine specialist clinician. The ESLR and MRI results were cross-tabulated. To obtain the odds ratio (OR) with positive ESLR or SLR results for LDH or nerve root compression (NC), a binary logistic regression analysis with subjects’ age, gender, height and weight was performed. ESLR’s validity was assessed by combination of interrater agreement and percentage prevalence of both LDH and NC. Results Of sciatic (ESLR+) patients, 85 % had LDH and 75 % NC in the MRI. Not surprisingly, MRI showed a very high incidence of ‘false-positive’ findings with the ESLR negative group. The ESLR showed 0.85 sensitivity and 0.45 specificity for LDH and 0.75 sensitivity and 0.50 specificity for NC. A positive result in the ESLR was found to be strongly associated with for both LDH and NC: the OR was 8.0 (p = 0.028) and 5.6 (p = 0.041), respectively. Conclusions The ESLR shows high validity in detecting neural symptoms and is strongly associated with pathology seen in the MRI when judged positive. We suggest the use of ESLR in clinical practice as a part of clinical examination, where it may prove to be a valuable tool in detecting patients with sciatic symptoms.


2019 ◽  
Vol 9 (8) ◽  
pp. 1760-1764
Author(s):  
Siyu Liu ◽  
Yuan Gao ◽  
Yu Liu ◽  
Jiabing Xiang

Objective: To compare the diagnostic effect of magnetic resonance imaging (MRI) and X-ray in degenerative osteoarthritis of knee joint. Methods: 107 patients with degenerative osteoarthrosis of the knee were selected as study subjects. They were divided into study group (53 cases) and control group (54 cases) according to different diagnostic methods. The study group underwent MRI examination for diagnosis, and the control group underwent X-ray examination for diagnosis. The diagnostic criteria of arthroscopic surgery were used as the gold standard to compare the diagnostic accuracy of patients with knee degenerative osteoarthrosis. Result: There was no significant difference in the detection rate of joint space stenosis and bone hyperplasia between the two groups (P > 0.05). Compared with the control group, the positive rate of synovial thickening, soft tissue swelling and meniscus degeneration was higher in the study group, and the difference was statistically significant (P < 0.05). Discussion: The progression of knee degenerative osteoarthrosis is very slow, and the clinical symptoms are not specific and inconspicuous. Especially in the early stage, knee cartilage injury and degeneration are not obvious. X-ray examination is used to diagnose the misdiagnosis. The rate is relatively high, and MRI, as a non-invasive examination method, has the advantages of high tissue resolution, multiazimuth imaging and multi-parameter imaging, which can clearly show the knee meniscus, articular cartilage, bone, ligament and other soft tissue injuries. The diagnosis is remarkable. Conclusion: The application of MRI in the diagnosis of degenerative osteoarthrosis of the knee is significant, which can further improve the diagnostic detection rate, and it is worthy of promotion and application in the diagnosis.


2018 ◽  
Vol 46 (11) ◽  
pp. 2687-2699 ◽  
Author(s):  
Cheng-Hao Zhang ◽  
Yan-Lin Jiang ◽  
Liang-Ju Ning ◽  
Qi Li ◽  
Wei-Li Fu ◽  
...  

Background: Achilles tendon (AT) defects frequently occur in trauma and chronic injuries. Currently, no method can satisfactorily reconstruct the AT with completely restored function. Purpose: To evaluate the postoperative outcomes of AT defect reconstruction with decellularized bovine tendon sheets (DBTSs) in a rabbit model. Study Design: Controlled laboratory study. Methods: DBTSs were prepared from bovine tendons after compression, decellularization, antigen extraction, freeze drying, and sterilization. Platelet-rich plasma (PRP) was obtained by differential centrifugation. Sixty-three rabbits were used in this study, and the AT defect model was created bilaterally. All rabbits were divided into 3 groups (n = 21). In the DBTS group and the DBTS + PRP group, 2-cm-long AT was excised and reconstructed by DBTSs or PRP-treated DBTSs. In the control group, the rabbits underwent AT transection, and stumps were sutured. After surgery, all rabbits were assessed by ultrasonography and magnetic resonance imaging and then sacrificed for histological examination and biomechanical testing at 4, 8, or 12 weeks. Results: Gross observations demonstrated the absence of immunologic incompatibility and rejection. Histological examination showed that DBTSs promoted host cell infiltration and new fibrous tissue integration as compared with the control group. In each group, there was an AT-like structure formation and aligned collagen fiber deposition at 12 weeks. Mechanical properties of the reconstructed AT were not significantly different among the 3 groups at 4, 8, and 12 weeks after surgery ( P > .05). Ultrasonography and magnetic resonance imaging results illustrated that the reconstructed AT from each group maintained remodeling, and there was no significant difference in the echogenicity scoring ( P > .05) and percentages of good and excellent ( P > .05) among the 3 groups. Conclusion: DBTSs, which retain the native tendon structure and bioactive factors, had the ability to remodel and integrate into the rabbit AT and improve the healing process. Clinical Relevance: DBTSs could serve as an effective bioscaffold to reconstruct AT defects.


2018 ◽  
Vol 45 (3-4) ◽  
pp. 124-131 ◽  
Author(s):  
Celine Guidoux ◽  
Jean-Jacques Hauw ◽  
Isabelle F. Klein ◽  
Julien Labreuche ◽  
Claudine Berr ◽  
...  

Background: Risk factors for intracerebral hemorrhage (ICH) include hypertension and cerebral amyloid angiopathy (CAA). The objective of this study was to determine the autopsy prevalence of CAA and the potential overlap with other risk factors among patients who died from ICH and also the correlation of CAA with cerebral microbleeds. Methods: We analyzed 81 consecutive autopsy brains from patients with ICH. Staining for CAA detection was performed. We used an age- and sex-matched control group of routine brain autopsies of nonneurological patients to determine the frequencies of CAA and hypertension. Postmortem 3D T2-weighted gradient-echo magnetic resonance imaging (MRI) with a 1.5-T magnet was performed in 11 brains with ICH (5 with CAA and 6 without) and histological correlation was performed when microbleeds were detected. Results: Hypertension and CAA were found in 69.1 and 24.7% of cases respectively. Among patients with CAA, 65.0% also had hypertension. The prevalence of CAA was similar among non-hypertensive cases and controls (33.3 and 23.1%; p = 0.54), whereas a significant difference was found between hypertensive cases vs. controls (28.9% vs. 0; p = 0.01). MRI documented 48 microbleeds and all 5 brains with CAA had ≥1 microbleed, compared to 3/6 brains without CAA. Among 48 microbleeds on MRI, 45 corresponded histologically to microbleeds surrounding microvessels (23 <200 µm in diameter, 19 between 200 µm and 2 mm, 3 were hemosiderin granules). Conclusions: Both hypertension and CAA frequently coexist in patients with ICH. MRI-detected microbleeds, proven by histological analysis, were twice as common in patients with CAA as in those with hypertensive ICH.


2021 ◽  
Author(s):  
Janne Pesonen ◽  
Michael Shacklock ◽  
Juha-Sampo Suomalainen ◽  
Lauri Karttunen ◽  
Jussi Mäki ◽  
...  

Abstract Background: The straight leg raise test (SLR) is one of the most utilized and studied physical tests in patients with low back pain (LBP) for the detection of lumbar disc herniation (LDH), showing high sensitivity and heterogeneous or low specificity. The high incidence of asymptomatic ‘pathologic’ findings in the magnetic resonance imaging (MRI) scans may cause verification bias to these results. We added location-specific structural differentiation movements to the traditional SLR for it to better differentiate neural symptoms from musculoskeletal. Previously, the ESLR has shown almost perfect interrater reliability between examiners and ability to detect sciatic patients. In this study, we investigated whether a ’positive’ ESLR finding predicts pathology seen on MRI.Methods: 40 subjects comprised the study population, 20 in sciatic group and 20 in control group. The ESLR was performed ‘blinded’ to the subjects. After the ESLR, each subject’s lumbar MRI was evaluated. The MRIs were analyzed independently by 2 senior radiologists and a spine specialist clinician. The ESLR and MRI results were cross-tabulated. To obtain the odds ratio (OR) with positive ESLR or SLR results for LDH or nerve root compression (NC), a binary logistic regression analysis with subjects’ age, gender, height and weight was performed. ESLR’s validity was assessed by combination of interrater agreement and percentage prevalence of both LDH and NC.Results: Of sciatic (ESLR+) patients, 85% had LDH and 75% NC in the MRI. Not surprisingly, MRI showed a very high incidence of ‘false-positive’ findings with the ESLR negative group. The ESLR showed 0.85 sensitivity and 0.45 specificity for LDH and 0.75 sensitivity and 0.50 specificity for NC. A positive result in the ESLR was found to be highly predictive for both LDH and NC: the OR was 8.0 (p=0.028) and 5.6 (p=0.041), respectively. Conclusion: The ESLR shows high validity in detecting neural symptoms and pathology seen in the MRI when judged positive. We suggest the use of ESLR in clinical practice, where it may prove to be a valuable tool in detecting patients with sciatic symptoms.


2021 ◽  
Vol 28 ◽  
pp. 221049172110395
Author(s):  
Roop Singh ◽  
Pradeep Kumar ◽  
Jitendra Wadhwani ◽  
Rohtas K Yadav ◽  
Mohit Khanna ◽  
...  

Objectives The present study aimed to investigate the association of disc degeneration with low back pain and the effect of ageing on disc degeneration in low back pain versus asymptomatic individuals. Methodology A total of 50 patients with chronic low back pain (Group A) were compared to 25 healthy controls (Group B). Both the groups were subjected to magnetic resonance imaging of the lumbar spine and the disc degeneration was measured by the Pfirrmann grading system. The study group (Group A) was further sub-grouped into A1 (lumbar spondylosis, n = 11), A2 (mechanical back pain, n = –13) and A3 (lumbar disc herniation, n = 26). Results There was a statistically significant difference in degeneration at the L4-L5 ( p = 0.001) and L5-S1 disc levels ( p = 0.001) between the two groups and contiguous disc involvement was more in low back pain patients. The subgroups of group A showed no statistically significant difference. Age showed a strong positive correlation ( r > 0.5) at all the lumbar levels (except at the L5-S1, r = 0.487) with Pfirrmann grading in Group A ( p = 0.001). There was a weak positive correlation ( r = 0.414) between age and Pfirrmann grade in the controls ( p = 0.04) at the L4-L5 level only. Conclusions Significantly higher Pfirrmann grading on magnetic resonance imaging was found at the L4-5 and L5-S1 levels in symptomatic patients suggesting higher involvement of these levels. Progressive disc degeneration is seen with ageing but in patients with low back pain, it is significantly accelerated.


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