scholarly journals The Severity of Ischemia Varies in Sprague-Dawley Rats from Different Vendors

ISRN Stroke ◽  
2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Simona Nikolova ◽  
Ting-Yim Lee ◽  
Robert Bartha
Keyword(s):  
Magnetic Resonance Imaging ◽  
Cerebral Perfusion ◽  
Lesion Size ◽  
Lesion Volume ◽  
Resonance Imaging ◽  
Sprague Dawley ◽  
Functional Deficits ◽  
Time Points ◽  
Sprague Dawley Rats ◽  
Stroke Lesion

The purpose of this study was to compare acute cerebral perfusion measured by computed tomography, stroke lesion volume measured by magnetic resonance imaging, and motor function in Sprague-Dawley rats supplied by Charles River (Charles River, Quebec, Canada) and Harlan (Harlan, Michigan, USA). During the acute stages of ischemia (<3 hours), Sprague-Dawley rats supplied by Harlan had a greater reduction in blood flow (67%) than rats supplied by Charles River (37%). MRI at days 1 and 6 after ischemia showed larger lesions in the Charles River animals compared to Harlan animals (P<0.05) at both time points. Lesion volume decreased in both Charles River and Harlan rats at day 6 compared to day 1 (P<0.05) and corresponded to lesion size on histology. The Harlan animals had significant functional deficits (P<0.05) one day after surgery in postural hang reflex, forelimb placement, and tactile fraction first tests, whereas rats supplied by Charles River had no significant functional impairment as a result of surgery. The current study provides evidence that differences in response to ischemia between rats of the same strain supplied by different vendors should be an important consideration when animals are selected for the study of cerebral ischemia.

scholarly journals Spectacular Shrinking Deficit: Insights from Multimodal Magnetic Resonance Imaging after Embolic Middle Cerebral Artery Occlusion in Sprague—Dawley Rats

2007 ◽  
Vol 27 (10) ◽  
pp. 1756-1763 ◽  
Author(s):  
Nils Henninger ◽  
Kenneth M Sicard ◽  
Marc Fisher
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Functional Magnetic Resonance Imaging ◽  
Middle Cerebral Artery ◽  
Artery Occlusion ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging ◽  
Sprague Dawley ◽  
Sprague Dawley Rats ◽  
Cerebral Artery Occlusion

Almost no data is available on the serial changes in the brain after spectacular shrinking deficit (SSD) that may help understand this relatively rare clinical phenomenon. Quantitative diffusion-(DWI), perfusion-(PWI), T1-(T1WI), T2-weighted (T2WI), and functional magnetic resonance imaging (fMRI) were performed before, during, and up to 7 days after embolic middle cerebral artery occlusion (eMCAO) in male Sprague—Dawley rats ( n = 9). Region of interest (ROI) analysis was used to evaluate structural and functional MR signal changes within three ROIs defined by the apparent diffusion coefficient (ADC), cerebral blood flow (CBF) signatures, and final tissue viability. DWI, PWI, and T2WI lesion volumes were calculated using previously established viability thresholds and final infarct volumes ascertained with 2,3,5-triphenyltetrazolium chloride (TTC) staining. Serial MRI demonstrated spontaneous reperfusion of initially hypoperfused MCA regions accompanied by substantial reduction of initial ADC and CBF lesions and gradual recovery of neurological outcome. Recovery rates of CBF/ADC abnormalities differed among ROIs. Functional magnetic resonance imaging showed persistent tissue dysfunction after the recovery of the CBF/ADC lesions. This study may facilitate our understanding of the pathophysiological mechanisms by which early, spontaneous reperfusion affects tissue fate and neurological function.

Erythrocyte Coupled tPA Improves Outcomes of Percussion Brain Trauma in Rats.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 897-897 ◽  
Author(s):  
Kumkum Ganguly ◽  
Sherman C. Stein ◽  
Robert F. Groff ◽  
Jun Zhang ◽  
Douglas H. Smith ◽  
...  
Keyword(s):  
Lesion Size ◽  
Brain Trauma ◽  
Lesion Volume ◽  
Sprague Dawley ◽  
Post Injury ◽  
Fluid Percussion Injury ◽  
Sprague Dawley Rats ◽  
Post Traumatic ◽  
Traumatic Thrombosis ◽  
Lateral Fluid Percussion

Abstract Coupling tissue plasminogen activator (tPA) to carrier red blood cells (RBC): i) restricts tPA’s permeation into tissues and pre-existing hemostatic clots, minimizing hemorrhage; ii) protects it from plasma inhibitors; and iii) prolongs its circulation, permitting incorporation into nascent clots and their lysis from within. These features support the thromboprophylactic utility of RBC coupled tPA (RBC/tPA). In this study we explored the utility of RBC/tPA in traumatic brain injury (TBI), a disorder in which both cerebral thrombosis leading to cerebral ischemia and intracerebral hemorrhage (ICH) have been implicated. Eleven male, Sprague-Dawley rats (340–400g) were subjected to a moderate (avg. peak pressure 2.6atm) lateral fluid percussion injury to the left hemisphere. Rats were given a single intravenous dose of RBC/tPA (0.05mg/Kg, n=5) or vehicle (n=4), 15 min post-injury. Animals were sacrificed 48h later for histopathology and staining for fibrin. The lesions in control animals occupied 8.3 ± 2.8% (mean±SD) of the hemispheric volume. Animals treated with RBC/tPA had a significant decrease in mean lesion volume (1.4±0.7%; p&lt;0.001). Thrombotic burden was reduced from a mean of 10 clots in vehicle-treated to 1 per RBC/tPA-treated rats p&lt;0.001). These data indicate that RBC/tPA attenuates post-traumatic thrombosis without aggravating hemorrhage induced by TBI. These observations support the safety of RBC/tPA in thromboprophylaxis even in the context of brain trauma, due to intravascular containment of RBC/tPA, among other factors. Durable lysis of post-traumatic thrombi by long-circulating RBC/tPA may alleviate secondary brain ischemia and resultant ICH. Correlation between reduction of thrombotic burden and lesion size implicate thrombosis in the pathophysiology of parenchymal brain damage after head trauma. Supported by PENN Research Foundation, HL66442, HL60169 and in part by NS38104.

Technical and radiographic considerations for magnetic resonance imaging–guided focused ultrasound capsulotomy

2020 ◽  
pp. 1-9 ◽  
Author(s):  
Benjamin Davidson ◽  
Karim Mithani ◽  
Yuexi Huang ◽  
Ryan M. Jones ◽  
Maged Goubran ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Focused Ultrasound ◽  
Neurosurgical Procedures ◽  
Lesion Volume ◽  
Angle Of Incidence ◽  
Resonance Imaging ◽  
Radiographic Findings ◽  
Compulsive Disorder ◽  
Skull Thickness

OBJECTIVEMagnetic resonance imaging–guided focused ultrasound (MRgFUS) is an emerging treatment modality that enables incisionless ablative neurosurgical procedures. Bilateral MRgFUS capsulotomy has recently been demonstrated to be safe and effective in treating obsessive-compulsive disorder (OCD) and major depressive disorder (MDD). Preliminary evidence has suggested that bilateral MRgFUS capsulotomy can present increased difficulties in reaching lesional temperatures as compared to unilateral thalamotomy. The authors of this article aimed to study the parameters associated with successful MRgFUS capsulotomy lesioning and to present longitudinal radiographic findings following MRgFUS capsulotomy.METHODSUsing data from 22 attempted MRgFUS capsulotomy treatments, the authors investigated the relationship between various sonication parameters and the maximal temperature achieved at the intracranial target. Lesion volume and morphology were analyzed longitudinally using structural and diffusion tensor imaging. A retreatment procedure was attempted in one patient, and their postoperative imaging is presented.RESULTSSkull density ratio (SDR), skull thickness, and angle of incidence were significantly correlated with the maximal temperature achieved. MRgFUS capsulotomy lesions appeared similar to those following MRgFUS thalamotomy, with three concentric zones observed on MRI. Lesion volumes regressed substantially over time following MRgFUS. Fractional anisotropy analysis revealed a disruption in white matter integrity, followed by a gradual return to near-baseline levels concurrent with lesion regression. In the patient who underwent retreatment, successful bilateral lesioning was achieved, and there were no adverse clinical or radiographic events.CONCLUSIONSWith the current iteration of MRgFUS technology, skull-related parameters such as SDR, skull thickness, and angle of incidence should be considered when selecting patients suitable for MRgFUS capsulotomy. Lesions appear to follow morphological patterns similar to what is seen following MRgFUS thalamotomy. Retreatment appears to be safe, although additional cases will be necessary to further evaluate the associated safety profile.

Aging Process of Lateral Facial Fat Compartments: A Retrospective Study

2021 ◽  
Author(s):  
Ching-Sheng Yang ◽  
Yau-Li Huang ◽  
Chun-Bing Chen ◽  
Chih-Ying Deng ◽  
Yu-Ting Liu ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Retrospective Study ◽  
Aging Process ◽  
Resonance Imaging ◽  
Fat Pad ◽  
Buccal Fat Pad ◽  
Time Points ◽  
Axial View ◽  
Labiomandibular Fold

Abstract Background Since 2007, when the anatomy of facial fat compartment was described, an increasing number of studies on the aging process of the compartment of cadavers has emerged. Objectives The authors evaluated the aging changes of lateral facial fat compartments on the same person. Methods Sixty-three patients were included in this retrospective study. All patients had magnetic resonance imaging scans with at least 4 years apart. The authors targeted the fat compartments of the superficial temporal, subcutaneous temporal, and buccal fat pad, comparing the data on different time points. Results The thickness of the subcutaneous temporal fat did not change significantly. The 3 diameters of the superficial temporal fat compartment all became thinner on the axial view (P &lt; 0.05). On the sagittal view, the superficial temporal fat elongated from 38.89 mm to 43.74 mm (P &lt; 0.05). The buccal fat compartment also lengthened from 68.73 mm to 74.39 mm (P &lt; 0.05) and had a positive correlation with follow-up duration only. Conclusions The study revealed the fat compartment change on the same person with time. The temporal hollow mainly originates from the thinner part of the superficial temporal fat. The descending of the buccal fat pad aggravates the labiomandibular fold. By understanding the aging process more fully, we can rejuvenate our patients more naturally.

scholarly journals N-Acetylcysteine Added to Local Anesthesia Reduces Scar Area and Width in Early Wound Healing—An Animal Model Study

2021 ◽  
Vol 22 (14) ◽  
pp. 7549
Author(s):  
Wiktor Paskal ◽  
Adriana M. Paskal ◽  
Piotr Pietruski ◽  
Albert Stachura ◽  
Kacper Pełka ◽  
...  
Keyword(s):  
Wound Healing ◽  
Early Stage ◽  
Healing Process ◽  
Wound Healing Process ◽  
Sprague Dawley ◽  
Time Points ◽  
Model Study ◽  
Sprague Dawley Rats ◽  
Animal Model Study ◽  
Anesthetic Solution

The aim of the study was to evaluate if a pre-incisional N-acetylcysteine (NAC) treatment altered the process of wound healing in a rat model. The dorsal skin of 24 Sprague-Dawley rats was incised in six locations. Before the incisions were made, skin was injected either with lidocaine and epinephrine (one side) or with these agents supplemented with 0.015%, 0.03%, or 0.045% NAC (contralaterally). Photographic documentation of the wound healing process was made at 11 time points. Rats were sacrificed 3, 7, 14, or 60 days after incision to excise scars for histological analysis. They included: Abramov scale scoring, histomorphometry analysis, and collagen fiber arrangement assessment. Skin pretreated with 0.03% NAC produced the shortest scars at all analyzed time points, though this result was statistically insignificant. At this NAC concentration the scars had smaller areas on the third day and were narrower on the day 4 compared with all the other groups (p < 0.05). On day 7, at the same concentration of NAC, the scars had a higher superficial concentration index (p = 0.03) and larger dermal proliferation area (p = 0.04). NAC addition to pre-incisional anesthetic solution decreased wound size and width at an early stage of scar formation at all concentrations; however, with optimal results at 0.03% concentration.

scholarly journals Monitoring ferumoxide-labelled neural progenitor cells and lesion evolution by magnetic resonance imaging in a model of cell transplantation in cerebral ischaemia

F1000Research ◽  
2014 ◽  
Vol 2 ◽  
pp. 252
Author(s):  
Rachael A Panizzo ◽  
David G Gadian ◽  
Jane C Sowden ◽  
Jack A Wells ◽  
Mark F Lythgoe ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Contrast Agent ◽  
Cerebral Ischaemia ◽  
Mri Contrast Agent ◽  
Lesion Volume ◽  
Mri Imaging ◽  
Resonance Imaging ◽  
Protamine Sulphate

Efficacy of neural stem/progenitor cell (NPC) therapies after cerebral ischaemia could be better evaluated by monitoring in vivo migration and distribution of cells post-engraftment in parallel with analysis of lesion volume and functional recovery. Magnetic resonance imaging (MRI) is ideally placed to achieve this, but still poses several challenges. We show that combining the ferumoxide MRI contrast agent Endorem with protamine sulphate (FePro) improves iron oxide uptake in cells compared to Endorem alone and is non-toxic. Hence FePro complex is a better contrast agent than Endorem for monitoring NPCs. FePro complex-labelled NPCs proliferated and differentiated normally in vitro, and upon grafting into the brain 48 hours post-ischaemia they were detected in vivo by MRI. Imaging over four weeks showed the development of a confounding endogenous hypointense contrast evolution at later timepoints within the lesioned tissue. This was at least partly due to accumulation within the lesion of macrophages and endogenous iron. Neither significant NPC migration, assessed by MRI and histologically, nor a reduction in the ischaemic lesion volume was observed in NPC-grafted brains.  Crucially, while MRI provides reliable information on engrafted cell location early after an ischaemic insult, pathophysiological changes to ischaemic lesions can interfere with cellular imaging at later timepoints.

scholarly journals Evaluation of the Influence of Zhenwu Tang on the Pharmacokinetics of Digoxin in Rats Using HPLC-MS/MS

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Chao Li ◽  
Dahu Liang ◽  
Yanhao Liu ◽  
Chaozhuang Shen ◽  
Xiaohu Wang ◽  
...  
Keyword(s):  
Deionized Water ◽  
Therapeutic Window ◽  
Sprague Dawley ◽  
Glycoprotein P ◽  
Active Efflux ◽  
Time Points ◽  
Sprague Dawley Rats ◽  
Combined Use ◽  
Positive Inotropic Drug ◽  
Excised Tissues

Digoxin (DIG) is a positive inotropic drug with a narrow therapeutic window that is used in the clinic for heart failure. The active efflux transporter of DIG, P-glycoprotein (P-gp), mediates DIG absorption and excretion in rats and humans. Up to date, several studies have shown that the ginger and Poria extracts in Zhenwu Tang (ZWT) affect P-gp transport activity. This study aimed to explore the effects of ZWT on the tissue distribution and pharmacokinetics of DIG in rats. The deionized water or ZWT (18.75 g/kg) was orally administered to male Sprague–Dawley rats once a day for 14 days as a pretreatment. On day 15, 1 hour after receiving deionized water or ZWT, the rats were given the solution of DIG at 0.045 mg/kg dose, and the collection of blood samples was carried out from the fundus vein or excised tissues at various time points. HPLC-MS/MS was used for the determination of the DIG concentrations in the plasma and the tissues under investigation. The pharmacokinetic interactions between DIG and ZWT after oral coadministration in rats revealed significant reductions in DIG Cmax and AUC0-∞, as well as significant increases in T1/2 and MRT0-∞. When coadministered with ZWT, the DIG concentration in four of the investigated tissues statistically decreased at different time points except for the stomach. This study found that combining DIG with ZWT reduced not only DIG plasma exposure but also DIG accumulation in tissues (heart, liver, lungs, and kidneys). The findings of our study could help to improve the drug's validity and safety in clinical applications and provide a pharmacological basis for the combined use of DIG and ZWT.

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