scholarly journals Apoptosis of endplate chondrocytes in cervical kyphosis is associated with chronic forward flexed neck: an in vivo rat bipedal walking model

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Jinliang Lai ◽  
Guanglin Ji ◽  
Yuqiao Zhou ◽  
Jincai Chen ◽  
Min Zhou ◽  
...  
Keyword(s):  
Critical Role ◽  
Bipedal Walking ◽  
Chondrocyte Apoptosis ◽  
Sprague Dawley ◽  
Cervical Kyphosis ◽  
Radiographic Findings ◽  
Cartilaginous Endplate ◽  
Histologic Changes

Abstract Background This study was undertaken to establish a rat bipedal walking model of cervical kyphosis (CK) associated with chronic forward flexed neck and assess the effects of chronic forward flexed neck on endplate chondrocytes. Methods Forty-eight 1-month-old Sprague-Dawley rats were randomly divided into 3 groups: forward flexed neck group (n = 16), bipedal group (n = 16), and normal group (n = 16). Cervical curves were analyzed on a lateral cervical spine X-ray using Harrison’s posterior tangent method before the experiment and at 2-week intervals for a 6-week period. Histologic changes in cartilaginous endplate chondrocytes were observed using hematoxylin and eosin (H&E) staining, transmission electron microscopy (TEM), and terminal deoxyribonucleotidyl transferase (TdT)-mediated dUTP nick-end labeling. Results Radiographic findings suggested a significantly decreased cervical physiological curvature in the forward flexed neck group over the 6-week follow-up; normal cervical curves were maintained in other groups. The average cervical curvature (C2–C7) was − 7.6 ± 0.9° in the forward flexed neck group before the experiment, − 3.9 ± 0.8° at 2 weeks post-experiment, 10.7 ± 1.0° at 4 weeks post-experiment, and 20.5 ± 2.1° at the last follow-up post-experiment. Histologically, results of H&E staining unveiled that cartilaginous endplate chondrocytes were arranged in an irregular fashion, with the decreased number at the observation period; the incidence of apoptotic cells in the forward flexed neck group was noticeably higher at the 6-week follow-up than that in other groups. Conclusions CK developed as the result of chronic forward flexed neck. Histologic changes suggested that chondrocyte apoptosis may play a critical role in the development of cervical kyphotic deformity associated with chronic forward flexed neck.

scholarly journals Interleukin-4 and Interleukin-13 Exacerbate Neurotoxicity of Prothrombin Kringle-2 in Cortex In Vivo via Oxidative Stress

2019 ◽  
Vol 20 (8) ◽  
pp. 1927 ◽  
Author(s):  
Jae Yeong Jeong ◽  
Young Cheul Chung ◽  
Byung Kwan Jin
Keyword(s):  
Oxidative Stress ◽  
Critical Role ◽  
Significant Loss ◽  
Interleukin 4 ◽  
Sprague Dawley ◽  
Reactive Microglia ◽  
Rat Cortex ◽  
Activated Microglia ◽  
Kringle 2

The present study investigated the effects of activated microglia-derived interleukin-4 (IL-4) and IL-13 on neurodegeneration in prothrombin kringle-2 (pKr-2)-treated rat cortex. pKr-2 was unilaterally injected into the Sprague–Dawley rat cerebral cortex and IL-4 and IL-13 neutralizing antibody was used to block the function of IL-4 and IL-13. Immunohistochemical analysis showed a significant loss of NeuN+ and Nissl+ cells and an increase of OX-42+ cells in the cortex at seven days post pKr-2. The levels of IL-4 and IL-13 expression were upregulated in the activated microglia as early as 12 hours post pKr-2 and sustained up to seven days post pKr-2. Neutralization by IL-4 or IL-13 antibodies (NA) significantly increased neuronal survival in pKr-2-treated rat cortex in vivo by suppressing microglial activation and the production of reactive oxygen species, as analyzed by immunohisotochemistry and hydroethidine histochemistry. These results suggest that IL-4 and IL-13 that were endogenously expressed from reactive microglia may play a critical role on neuronal death by regulating oxidative stress during the neurodegenerative diseases, such as Alzheimer’s disease and dementia.

scholarly journals Red blood cells in hemorrhagic shock: a critical role for glutaminolysis in fueling alanine transamination in rats

2017 ◽  
Vol 1 (17) ◽  
pp. 1296-1305 ◽  
Author(s):  
Julie A. Reisz ◽  
Anne L. Slaughter ◽  
Rachel Culp-Hill ◽  
Ernest E. Moore ◽  
Christopher C. Silliman ◽  
...  
Keyword(s):  
Hemorrhagic Shock ◽  
Red Blood Cells ◽  
Blood Cells ◽  
Metabolic Flux ◽  
Critical Role ◽  
Metabolic Reprogramming ◽  
Flux Analysis ◽  
Sprague Dawley ◽  
Life Years

Abstract Red blood cells (RBCs) are the most abundant host cell in the human body and play a critical role in oxygen transport and systemic metabolic homeostasis. Hypoxic metabolic reprogramming of RBCs in response to high-altitude hypoxia or anaerobic storage in the blood bank has been extensively described. However, little is known about the RBC metabolism following hemorrhagic shock (HS), the most common preventable cause of death in trauma, the global leading cause of total life-years lost. Metabolomics analyses were performed through ultra-high pressure liquid chromatography–mass spectrometry on RBCs from Sprague-Dawley rats undergoing HS (mean arterial pressure [MAP], <30 mm Hg) in comparison with sham rats (MAP, >80 mm Hg). Steady-state measurements were accompanied by metabolic flux analysis upon tracing of in vivo–injected 13C15N-glutamine or inhibition of glutaminolysis using the anticancer drug CB-839. RBC metabolic phenotypes recapitulated the systemic metabolic reprogramming observed in plasma from the same rodent model. Results indicate that shock RBCs rely on glutamine to fuel glutathione (GSH) synthesis and pyruvate transamination, whereas abrogation of glutaminolysis conferred early mortality and exacerbated lactic acidosis and systemic accumulation of succinate, a predictor of mortality in the military and civilian critically ill populations. Glutamine is here identified as an essential amine group donor in HS RBCs, plasma, liver, and lungs, providing additional rationale for the central role glutaminolysis plays in metabolic reprogramming and survival following severe hemorrhage.

scholarly journals Contractile function, sarcolemma integrity, and the loss of dystrophin after skeletal muscle eccentric contraction-induced injury

2004 ◽  
Vol 286 (2) ◽  
pp. C230-C238 ◽  
Author(s):  
Richard M. Lovering ◽  
Patrick G. De Deyne
Keyword(s):  
Structural Changes ◽  
Contractile Function ◽  
Critical Role ◽  
Eccentric Contraction ◽  
Selective Vulnerability ◽  
Muscle Membrane ◽  
Blue Dye ◽  
Sprague Dawley ◽  
Sprague Dawley Rats

The purpose of this study was to evaluate the integrity of the muscle membrane and its associated cytoskeleton after a contraction-induced injury. A single eccentric contraction was performed in vivo on the tibialis anterior (TA) of male Sprague-Dawley rats at 900°/s throughout a 90°-arc of motion. Maximal tetanic tension (Po) of the TAs was assessed immediately and at 3, 7, and 21 days after the injury. To evaluate sarcolemmal integrity, we used an Evans blue dye (EBD) assay, and to assess structural changes, we used immunofluorescent labeling with antibodies against contractile (myosin, actin), cytoskeletal (α-actinin, desmin, dystrophin, β-spectrin), integral membrane (α- and β-dystroglycan, sarcoglycan), and extracellular (laminin, fibronectin) proteins. Immediately after injury, P0 was significantly reduced to 4.23 ± 0.22 N, compared with 8.24 ± 1.34 N in noninjured controls, and EBD was detected intracellularly in 54 ± 22% of fibers from the injured TA, compared with 0% in noninjured controls. We found a significant association between EBD-positive fibers and the loss of complete dystrophin labeling. The loss of dystrophin was notable because organization of other components of the subsarcolemmal cytoskeleton was affected minimally (β-spectrin) or not at all (α- and β-dystroglycan). Labeling with specific antibodies indicated that dystrophin's COOH terminus was selectively more affected than its rod domain. Twenty-one days after injury, contractile properties were normal, fibers did not contain EBD, and dystrophin organization and protein level returned to normal. These data indicate the selective vulnerability of dystrophin after a single eccentric contraction-induced injury and suggest a critical role of dystrophin in force transduction.

The critical role of the intrinsic VSMC proliferation and death programs in injury-induced neointimal hyperplasia

2008 ◽  
Vol 294 (5) ◽  
pp. H2276-H2284 ◽  
Author(s):  
Zakar H. Mnjoyan ◽  
Dennis Doan ◽  
Jimi Lynn Brandon ◽  
Kumar Felix ◽  
Christy L. Sitter ◽  
...  
Keyword(s):  
Neointimal Hyperplasia ◽  
Critical Role ◽  
Coronary Intervention ◽  
Cellular Level ◽  
Terminal Deoxynucleotidyl Transferase ◽  
Sprague Dawley ◽  
Vsmc Proliferation ◽  
Sprague Dawley Rats

Postangioplasty and in-stent restenosis remain ominous problems in percutaneous coronary intervention where good animal models of restenosis proneness and resistance are needed. We accidentally discovered that the carotid arteries (CAs) of the Harlan and Sasco substrains of Sprague-Dawley rats display drastically different restenosis phenotypes following balloon-induced endothelial denudation. When subjected to balloon injury, Sasco CAs exhibited significantly larger neointimal mass than did Harlan CAs at both days 14 and 32, as evidenced by a higher intima-to-media ratio and a greater number of intimal cells in Sasco CAs. This was due to a greater cell proliferation and to a less vigorous apoptosis of Sasco neointima, as assessed by 5-bromo-2′-deoxyuridine and terminal deoxynucleotidyl transferase-deoxyuridine nick-end labeling staining, respectively. At a cellular level, whereas vascular smooth muscle cells (VSMCs) isolated from Sasco and Harlan CAs were identical in morphology and in propensity to migrate, Sasco VSMCs proliferated more robustly and died far less, suggesting that under the exact same microenvironment, Sasco and Harlan VSMCs respond to growth and noxious stimuli in a drastically different fashion and that Sasco's significantly more robust neointimal proliferation after vascular injury in vivo can be accounted for by these intrinsic differences in VSMCs of these substrains in vitro. Sasco and Harlan Sprague-Dawley rats as well as VSMCs from these rats will prove to be powerful tools to study genes involved in the pathogenesis of restenosis.

P1594Ventricular fibrosis spatial distribution and quantity is a key mechanistic determinant of ventricular fibrillation mechanisms

2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
B S Handa ◽  
X Li ◽  
C A Mansfield ◽  
R J Jabbour ◽  
D Pitcher ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Ventricular Fibrillation ◽  
Critical Role ◽  
Underlying Mechanism ◽  
Dominant Frequency ◽  
Diffuse Fibrosis ◽  
Sprague Dawley ◽  
Average Maximum ◽  
Ventricular Fibrosis

Abstract Background Ventricular fibrosis is known to play a critical role in initiation and maintenance of ventricular fibrillation (VF). Post myocardial infarction the quantity of fibrosis negatively correlates with survival. There is a lack of data on how the quantity and degree of fibrosis influences the mechanisms of VF itself. VF mechanisms remain debated, there are data to support both critical areas sustaining rotational drivers (RDs) and the contrary hypothesis of disorganized myocardial activation driving VF. Purpose We hypothesized that the underlying mechanism of VF is influenced by the spatial distribution and quantity of ventricular fibrosis. Methods Thirty-five Sprague-Dawley rats underwent permanent left anterior descending (LAD) ligation (n=11), 20mins LAD territory ischaemia-reperfusion (n=13) or in-vivo angiotensin infusion (500ng/kg/min, n=11) to generate compact (CF), patchy (PF) and diffuse fibrosis (DF) models respectively. After a 4-week maturation period, the hearts were explanted, Langendorff perfused and VF induced with burst pacing and 30μM pinacidil. Fibrillation dynamics were quantified using phase analysis, phase singularity (PS) tracking and our novel method of global fibrillation organisation quantification, frequency dominance index (FDI), which is a power ratio of highest amplitude dominant frequency in the frequency spectrum. Results Ventricular fibrosis for each group was characterized and quantified (CF: 22.3±3.2%, PF: 18.4±4.2%, DF: 5.8±1.3%, p=0.046). VF was driven predominantly by disorganised activity in CF, PSs were detected 26±7% of time comparative to 51.2±4% in DF and 69.5±8% in PF group (p=0.001). PF stabilised RDs, average maximum rotations for a single RD in PF were 31.6±7.1 comparative to 12.5±1.7 in DF and 6.4±1.1 in CF, p<0.001. The average maximum duration for a single RDs was significantly longer in PF (PF: 1231±365ms, DF: 568±68ms, CF: 363±41ms, p=0.014). Similarly, average rotations per RD were greater in the PF group (PF: 4.5±0.7, DF: 3.3±0.2, CF: 2.41±0.3 rotations, p=0.013). Total number of RDs/second were much greater with PF (PF: 12.4±2.0, DF: 5.4±0.8, CF: 3.1±1.1, p<0.001). VF organisation measured by FDI was higher in PF (PF: 0.61±0.07, DF: 0.47±0.04, CF: 0.33±0.03, p=0.004). RDs in DF showed a greater degree of meander comparative to PF (DF: 12.6±1.4 vs PF: 9.3±0.8 pixels, p=0.024). Conclusion VF mechanisms occur along a spectrum between organised activity sustained by discrete drivers and disorganised myocardial activation. The underlying VF mechanism can differ significantly dependent on the quantity and pattern of fibrosis. Patchy fibrosis stabilises RDs with localization to discrete areas and sustains an organised form of VF comparative to CF where VF is largely disorganised. Characterising the degree and pattern of fibrosis in patient groups vulnerable to VF might be beneficial in identifying patients with suitable targets for ablation. Acknowledgement/Funding BHF Programme Grant PG/16/17/32069

scholarly journals Inhibition of JNK activation prolongs survival after smoke inhalation from fires

2007 ◽  
Vol 292 (4) ◽  
pp. L984-L991 ◽  
Author(s):  
Olga L. Syrkina ◽  
Deborah A. Quinn ◽  
Walter Jung ◽  
Bin Ouyang ◽  
Charles A. Hales
Keyword(s):  
Lung Injury ◽  
Critical Role ◽  
Inflammatory Cells ◽  
Smoke Inhalation ◽  
Sprague Dawley ◽  
Jnk Pathway ◽  
Initial Injury ◽  
Acute Inflammatory Cell ◽  
Jnk Activation

Initial injury from smoke inhalation is mainly to the trachea and bronchi and is characterized by mucosal hyperemia and increased microvascular permeability, exfoliation of epithelial lining, mucous secretion, mucous plugging, and an acute inflammatory cell influx. In this study, we explore the role of the c-Jun N-terminal protein kinase (JNK) pathway in smoke inhalation lung injury using a rat model of exposure to smoke from burning cotton. Male Sprague-Dawley rats were exposed to smoke from burning cotton for 15 min, and 1 h after injury a JNK inhibitor (SP-600125) or vehicle was injected. We measured neutrophil influx, cytokine release, percent of apoptotic cells, airway plugging, and survival. Administration of a JNK inhibitor 1 h after smoke inhalation decreased airway apoptosis, mucous plugging, influx of inflammatory cells, and the release of cytokines and significantly prolonged animal survival ( P < 0.05). These in vivo data show that the JNK pathway plays a critical role in smoke-induced lung injury and offer an attractive therapeutic approach for this injury.

The Critical Role of Concentration for Lidocaine Block of Peripheral Nerve In Vivo 

2003 ◽  
Vol 99 (5) ◽  
pp. 1189-1197 ◽  
Author(s):  
Tadashi Nakamura ◽  
Frederique Popitz-Bergez ◽  
John Birknes ◽  
Gary R. Strichartz
Keyword(s):  
Sciatic Nerve ◽  
Peripheral Nerve ◽  
Nerve Block ◽  
Local Anesthetic ◽  
Critical Role ◽  
Longitudinal Distribution ◽  
Total Drug ◽  
Sprague Dawley ◽  
Minimal Blocking

Background The adjustment of local anesthetic dosage for peripheral nerve block must meet two basic requirements: a drug concentration sufficient to inhibit Na+ channels to the point of impulse failure and a volume of drug sufficient to expose a length of nerve longer than the "critical length" for propagation failure. This study examines the lidocaine dosage requirement, in milligrams, for functionally assayed sciatic nerve block in the rat using a fourfold range of volume corresponding to concentrations from 2 to 7 mg/ml and compares these blocks with the intraneural lidocaine content after injection of equipotent doses. Methods Lidocaine was injected percutaneously at the sciatic nerve in volumes of 0.05 ml, 0.1 ml, and 0.2 ml (all at pH 6.8), and quantitative neurobehavioral assays were conducted on male Sprague-Dawley rats weighing from 200 to 250 g. The dose requirements for 50% maximum possible effect (ED50) and for just achieving complete block (i.e., minimal blocking dose for 90% effect), the fraction of completely blocked animals, and the duration of complete block at all doses were assessed for the inhibition of three different functions: proprioception, motor, and nocifensive activities. Radiolabeled (14C) lidocaine was injected in separate experiments, and the total drug content and its longitudinal distribution were determined in nerves dissected from animals (sevoflurane anesthetized) at 10 min, the time of peak block, after injection of the E50 and minimal blocking dose for 100% effect for the three different volumes. Results For all functions, the smaller the volume, the lower was the E50, resulting in a nearly constant concentration to achieve an equivalent degree of block. Durations of block were longer, and the dose to full block was lower for the smaller injected volumes. Intraneural lidocaine, at the equipotent doses for analgesia, was not related to concentration but rather increased with increasing volume, being almost proportional to the given dose. The longitudinal spread of lidocaine was also greater with increasing volume of lidocaine solution. Conclusion Blocks of greater depth and longer duration result from injection of smaller volumes and, correspondingly, higher lidocaine concentrations containing the same dose. The corollary is that lower lidocaine doses are required to achieve the same effect when smaller volumes are injected. Curiously, when the equivalent E50 is injected, total drug taken into the nerve is less from the smaller volumes than from the larger volumes, even though the peak functional effects are equal. Total intraneural local anesthetic may not represent the effective drug in the compartment that contains nerve axons, the actual location of neural blockade.

Sinusoidal Cells in Bone Marrow Take Up BSA-Au Conjugates in the Presence of an Artificial Blood Substitute

1985 ◽  
Vol 43 ◽  
pp. 700-701
Author(s):  
J.S. Geoffroy ◽  
R.P. Becker
Keyword(s):  
Bone Marrow ◽  
Los Angeles ◽  
Iliac Artery ◽  
Blood Substitute ◽  
Sprague Dawley ◽  
Coated Pits ◽  
Sinusoidal Cells ◽  
Artificial Blood ◽  
Left Common Iliac Artery

The pattern of BSA-Au uptake in vivo by endothelial cells of the venous sinuses (sinusoidal cells) of rat bone marrow has been described previously. BSA-Au conjugates are taken up exclusively in coated pits and vesicles, enter and pass through an “endosomal” compartment comprised of smooth-membraned tubules and vacuoles and cup-like bodies, and subsequently reside in multivesicular and dense bodies. The process is very rapid, with BSA-Au reaching secondary lysosmes one minute after presentation. (Figure 1)In further investigations of this process an isolated limb perfusion method using an artificial blood substitute, Oxypherol-ET (O-ET; Alpha Therapeutics, Los Angeles, CA) was developed. Under nembutal anesthesia, male Sprague-Dawley rats were laparotomized. The left common iliac artery and vein were ligated and the right iliac artery was cannulated via the aorta with a small vein catheter. Pump tubing, preprimed with oxygenated 0-ET at 37°C, was connected to the cannula.

Preparation of cultured astrocytes for x-ray microanalysis

1989 ◽  
Vol 47 ◽  
pp. 988-989
Author(s):  
N.K.R. Smith ◽  
K.E. Hunter ◽  
P. Mobley ◽  
L.P. Felpel
Keyword(s):  
Cultured Cells ◽  
Elemental Content ◽  
Elemental Distribution ◽  
Sprague Dawley ◽  
X Ray ◽  
Cultured Astrocytes ◽  
Freeze Dried ◽  
Ultimate Objective

Electron probe energy dispersive x-ray microanalysis (XRMA) offers a powerful tool for the determination of intracellular elemental content of biological tissue. However, preparation of the tissue specimen , particularly excitable central nervous system (CNS) tissue , for XRMA is rather difficult, as dissection of a sample from the intact organism frequently results in artefacts in elemental distribution. To circumvent the problems inherent in the in vivo preparation, we turned to an in vitro preparation of astrocytes grown in tissue culture. However, preparations of in vitro samples offer a new and unique set of problems. Generally, cultured cells, growing in monolayer, must be harvested by either mechanical or enzymatic procedures, resulting in variable degrees of damage to the cells and compromised intracel1ular elemental distribution. The ultimate objective is to process and analyze unperturbed cells. With the objective of sparing others from some of the same efforts, we are reporting the considerable difficulties we have encountered in attempting to prepare astrocytes for XRMA.Tissue cultures of astrocytes from newborn C57 mice or Sprague Dawley rats were prepared and cultured by standard techniques, usually in T25 flasks, except as noted differently on Cytodex beads or on gelatin. After different preparative procedures, all samples were frozen on brass pins in liquid propane, stored in liquid nitrogen, cryosectioned (0.1 μm), freeze dried, and microanalyzed as previously reported.

Facilitated migration of cells from a transected peripheral nerve over collagen fibers: in vivo observations

1989 ◽  
Vol 47 ◽  
pp. 888-889
Author(s):  
Arthur J. Wasserman ◽  
Azam Rizvi ◽  
George Zazanis ◽  
Frederick H. Silver
Keyword(s):  
Sciatic Nerve ◽  
Peripheral Nerve ◽  
Collagen Gel ◽  
Collagen Fibers ◽  
Control Group ◽  
Guide Tube ◽  
Sprague Dawley ◽  
Silicone Tube ◽  
Thin Sections

In cases of peripheral nerve damage the gap between proximal and distal stumps can be closed by suturing the ends together, using a nerve graft, or by nerve tubulization. Suturing allows regeneration but does not prevent formation of painful neuromas which adhere to adjacent tissues. Autografts are not reported to be as good as tubulization and require a second surgical site with additional risks and complications. Tubulization involves implanting a nerve guide tube that will provide a stable environment for axon proliferation while simultaneously preventing formation of fibrous scar tissue. Supplementing tubes with a collagen gel or collagen plus extracellular matrix factors is reported to increase axon proliferation when compared to controls. But there is no information regarding the use of collagen fibers to guide nerve cell migration through a tube. This communication reports ultrastructural observations on rat sciatic nerve regeneration through a silicone nerve stent containing crosslinked collagen fibers.Collagen fibers were prepared as described previously. The fibers were threaded through a silicone tube to form a central plug. One cm segments of sciatic nerve were excised from Sprague Dawley rats. A control group of rats received a silicone tube implant without collagen while an experimental group received the silicone tube containing a collagen fiber plug. At 4 and 6 weeks postoperatively, the implants were removed and fixed in 2.5% glutaraldehyde buffered by 0.1 M cacodylate containing 1.5 mM CaCl2 and balanced by 0.1 M sucrose. The explants were post-fixed in 1% OSO4, block stained in 1% uranyl acetate, dehydrated and embedded in Epon. Axons were counted on montages prepared at a total magnification of 1700x. Montages were viewed through a dissecting microscope. Thin sections were sampled from the proximal, middle and distal regions of regenerating sciatic plugs.

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