Stifle: In horses, cattle, and other quadrupeds, the joint between the femur and the tibia, corresponding to the human knee.Lameness, Animal: A departure from the normal gait in animals.Anterior Cruciate Ligament: A strong ligament of the knee that originates from the posteromedial portion of the lateral condyle of the femur, passes anteriorly and inferiorly between the condyles, and attaches to the depression in front of the intercondylar eminence of the tibia.Osteochondritis: Inflammation of a bone and its overlaying CARTILAGE.Dog Diseases: Diseases of the domestic dog (Canis familiaris). This term does not include diseases of wild dogs, WOLVES; FOXES; and other Canidae for which the heading CARNIVORA is used.Dogs: The domestic dog, Canis familiaris, comprising about 400 breeds, of the carnivore family CANIDAE. They are worldwide in distribution and live in association with people. (Walker's Mammals of the World, 5th ed, p1065)Cartilage, Articular: A protective layer of firm, flexible cartilage over the articulating ends of bones. It provides a smooth surface for joint movement, protecting the ends of long bones from wear at points of contact.Hindlimb: Either of two extremities of four-footed non-primate land animals. It usually consists of a FEMUR; TIBIA; and FIBULA; tarsals; METATARSALS; and TOES. (From Storer et al., General Zoology, 6th ed, p73)Osteoarthritis: A progressive, degenerative joint disease, the most common form of arthritis, especially in older persons. The disease is thought to result not from the aging process but from biochemical changes and biomechanical stresses affecting articular cartilage. In the foreign literature it is often called osteoarthrosis deformans.Joint DiseasesOsteochondrosis: Any of a group of bone disorders involving one or more ossification centers (EPIPHYSES). It is characterized by degeneration or NECROSIS followed by revascularization and reossification. Osteochondrosis often occurs in children causing varying degrees of discomfort or pain. There are many eponymic types for specific affected areas, such as tarsal navicular (Kohler disease) and tibial tuberosity (Osgood-Schlatter disease).Knee Joint: A synovial hinge connection formed between the bones of the FEMUR; TIBIA; and PATELLA.Encyclopedias as Topic: Works containing information articles on subjects in every field of knowledge, usually arranged in alphabetical order, or a similar work limited to a special field or subject. (From The ALA Glossary of Library and Information Science, 1983)Tibia: The second longest bone of the skeleton. It is located on the medial side of the lower leg, articulating with the FIBULA laterally, the TALUS distally, and the FEMUR proximally.

Exacerbation of antigen-induced arthritis in inducible nitric oxide synthase-deficient mice. (1/146)

OBJECTIVE: Inhibition of nitric oxide (NO) produced by inducible NO synthase (iNOS) is suggested to be beneficial in experimental arthritis. Although NO is important for the integrity of the microcirculation, the effects of inhibition of iNOS on the synovial microcirculation are not currently known. This study investigated the synovial microcirculation and leukocyte-endothelial cell interactions in iNOS-deficient mice with antigen-induced arthritis (AIA) and compared these findings with disease severity. METHODS: Fourteen homozygous iNOS-/- and 14 iNOS+/+ mice were used. The severity of AIA was assessed by measuring knee joint swelling and by histologic scoring. The number of rolling and adherent leukocytes was quantitatively analyzed in synovial microvessels using intravital microscopy of intraarticular synovial tissue. Nitrite/nitrate concentrations were measured, and the expression of iNOS, E- and P-selectin, intercellular adhesion molecule 1, and vascular cell adhesion molecule 1 (VCAM-1) was assessed by immunohistochemistry. RESULTS: In iNOS+/+ animals with AIA, the plasma concentration of nitrite/nitrate was increased 3-fold and iNOS expression was detected in cells of the joint. Swelling of the knee joint as well as leukocyte infiltration were enhanced in the iNOS-/- arthritic animals compared with iNOS+/+ mice with AIA. AIA-associated leukocyte-endothelial cell interaction in synovial postcapillary venules was more pronounced in iNOS-/-, compared with iNOS+/+, arthritic mice. A strong expression of P-selectin and VCAM-1 was observed in the iNOS-/- arthritic mice only. CONCLUSION: These data suggest that NO production by iNOS in vivo has antiinflammatory effects in experimental arthritis, by mediating a reduction in leukocyte adhesion and infiltration.  (+info)

Matrix metalloproteinases and aggrecanases cleave aggrecan in different zones of normal cartilage but colocalize in the development of osteoarthritic lesions in STR/ort mice. (2/146)

OBJECTIVE: To map aggrecan cleavage by matrix metalloproteinases (MMPs) and aggrecanases in normal murine tibial articular cartilage (CBA strain) and in the development of spontaneous osteoarthritis (OA) in the STR/ort mouse and to assess the influence of sex hormone status on these conditions in gonadectomized STR/ort mice. METHODS: The distributions of neoepitopes of aggrecan generated by MMP (VDIPEN) and aggrecanase (NITEGE) cleavage were investigated by immunohistochemistry. RESULTS: VDIPEN neoepitope was detected mainly in the pericellular matrix of deep-zone chondrocytes in normal tibial cartilage from STR/ort and CBA mice. In early OA, VDIPEN immunostaining also localized to the pericellular matrix of chondrocytes at the site of the lesion. With increasing severity of OA lesions, VDIPEN immunostaining was also detected in the interterritorial matrix, close to the site of the lesion. In contrast, NITEGE mapped most strongly to the pericellular matrix of upper-zone chondrocytes in normal tibial cartilage. As with VDIPEN, NITEGE was strongly expressed in the pericellular matrix at the site of early OA lesions. With advancing OA, NITEGE colocalized with VDIPEN in both the pericellular and interterritorial matrices of chondrocytes adjacent to OA lesions and in those of the deep zones. Hormone status did not appear to influence the development of OA or the distribution of aggrecan neoepitopes in STR/ort mice. CONCLUSION: MMP- and aggrecanase-generated neoepitopes map predominantly to different regions in normal murine tibial cartilage. However, both groups of enzymes generate increased amounts of neoepitopes in pericellular and interterritorial matrix adjacent to histopathologic lesions of OA. Aggrecan degradation and the development of OA appear to be independent of sex hormone status in this model.  (+info)

Processing of nociceptive mechanical and thermal information in central amygdala neurons with knee-joint input. (3/146)

Pain has a strong emotional dimension, and the amygdala plays a key role in emotionality. The processing of nociceptive mechanical and thermal information was studied in individual neurons of the central nucleus of the amygdala, the target of the spino-parabrachio-amygdaloid pain pathway and a major output nucleus of the amygdala. This study is the first to characterize nociceptive amygdala neurons with input from deep tissue, particularly the knee joint. In 46 anesthetized rats, extracellular single-unit recordings were made from 119 central amygdala neurons that were activated orthodromically by electrical stimulation in the lateral pontine parabrachial area and were tested for receptive fields in the knee joints. Responses to brief mechanical stimulation of joints, muscles, and skin and to cutaneous thermal stimuli were recorded. Receptive-field sizes and thresholds were mapped and stimulus-response functions constructed. Neurons in the central nucleus of the amygdala with excitatory input from the knee joint (n = 62) typically had large symmetrical receptive fields in both hindlimbs or in all four extremities and responded exclusively or preferentially to noxious mechanical stimulation of deep tissue (n = 58). Noxious mechanical stimulation of the skin excited 30 of these neurons; noxious heat activated 21 neurons. Stimulus-response data were best fitted by a sigmoid nonlinear regression model rather than by a monotonically increasing linear function. Another 15 neurons were inhibited by noxious mechanical stimulation of the knee joint and other deep tissue. Fifteen neurons had no receptive field in the knee but responded to noxious stimulation of other body areas; 27 nonresponsive neurons were not activated by natural somesthetic stimulation. Our data suggest that excitation is the predominant effect of brief painful stimulation of somatic tissue on the population of central amygdala neurons with knee joint input. Their large symmetrical receptive fields and sigmoid rather than monotonically increasing linear stimulus-response functions suggest a role of nociceptive central amygdala neurons in other than sensory-discriminative aspects of pain.  (+info)

Complex polysaccharide inclusions in skeletal muscle adjacent to sarcomas in two dogs. (4/146)

Inclusions of periodic acid-Schiff-positive, amylase resistant material were found within skeletal muscle fibers adjacent to an osteosarcoma in the proximal femur of an 8-year-old intact female Cocker Spaniel dog (dog No. 1) and adjacent to a synovial cell sarcoma of the stifle joint in a 7-year-old spayed female Bouvier des Flandres dog (dog No. 2). Inclusions were pale blue-gray with hematoxylin and eosin stain and formed irregular inclusions, replacing up to approximately 80% of the fiber diameter. Inclusions from dog No. 2 were of non-membrane-bound granular to filamentous material that occasionally formed discrete, elongate electron-dense masses. The features of these inclusions were similar to those of materials previously described as complex polysaccharide, polyglucosan bodies, amylopectin, and Lafora bodies. Evidence for a generalized metabolic disorder was not found in these two dogs, suggesting that storage of complex polysaccharide can occur as a relatively nonspecific response to metabolic alterations in skeletal muscle in a variety of conditions.  (+info)

Differential function of nitric oxide in murine antigen-induced arthritis. (5/146)

BACKGROUND: The aim of our study was to investigate the role of inducible nitric oxide synthase (iNOS)-derived nitric oxide (NO) production in different stages of murine antigen-induced arthritis (AiA). METHODS: Clinical, histological and microcirculatory parameters (measured by intravital fluorescence microscopy) were assessed in the knee joint during acute and chronic AiA after inhibition of iNOS with L-N(6)-(1-iminoethyl)lysine (L-NIL). Plasma concentrations of and were evaluated by the Griess reaction and the expression of iNOS, P- and E-selectin, intercellular adhesion molecule 1 (ICAM-1) and vascular cell adhesion molecule 1 (VCAM-1) by immunohistochemistry. RESULTS: In both stages of the disease, plasma concentrations of and were increased and iNOS was expressed. In the acute phase, swelling, leucocyte adhesion, leucocyte infiltration and expression of adhesion molecules were increased in arthritic animals treated with L-NIL in comparison with untreated arthritic animals. In the chronic phase, no change in the disease parameters could be detected after L-NIL treatment. CONCLUSION: Increased NO production induced by iNOS during the acute phase of AiA can be regarded as a protective response in the prevention of further leucocytic infiltration and joint destruction, whereas it seems to play a subordinate role in chronic AiA.  (+info)

One of two chondrocyte-expressed isoforms of cartilage intermediate-layer protein functions as an insulin-like growth factor 1 antagonist. (6/146)

OBJECTIVE: Aging and osteoarthritic (OA) cartilage commonly demonstrate enhanced expression of the large, transforming growth factor beta (TGFbeta)-inducible glycoprotein cartilage intermediate-layer protein (CILP) as well as enhanced extracellular inorganic pyrophosphate (PPi) that promotes the deposition of calcium pyrophosphate dihydrate crystals. In normal chondrocytes, TGFbeta induces elevated chondrocyte extracellular PPi. Insulin-like growth factor 1 (IGF-1) normally blocks this response and reduces extracellular PPi. However, chondrocyte resistance to IGF-1 is observed in OA and aging. Because CILP was reported to chromatographically fractionate with PPi-generating nucleotide pyrophosphatase phosphodiesterase (NPP) activity, it has been broadly assumed that CILP itself has NPP activity. Our objective was to directly define CILP functions and their relationship to IGF-1 in chondrocytes. METHODS: Using primary cultures of articular chondrocytes from the knee, we defined the function of the previously described CILP (CILP-1) and of a recently described 50.6% identical protein that we designated the CILP-2 isoform. RESULTS: Both CILP isoforms were constitutively expressed by primary cultured articular chondrocytes, but only CILP-1 expression was detectable in cultured knee meniscal cartilage cells. Neither CILP isoform had intrinsic NPP activity. But CILP-1 blocked the ability of IGF-1 to decrease extracellular PPi, an activity specific for the CILP-1 N-terminal domain. The CILP-1 N-terminal domain also suppressed IGF-1-induced (but not TGFbeta-induced) proliferation and sulfated proteoglycan synthesis, and it inhibited ligand-induced IGF-1 receptor autophosphorylation. CONCLUSION: Two CILP isoforms are differentially expressed by chondrocytes. Neither CILP isoform exhibits PPi-generating NPP activity. But, increased expression of CILP-1, via N-terminal domain-mediated inhibitory effects of CILP-1 on chondrocyte IGF-1 responsiveness, could impair chondrocyte growth and matrix repair and indirectly promote PPi supersaturation in aging and OA cartilage.  (+info)

Hamstring graft technique for stabilization of canine cranial cruciate ligament deficient stifles. (7/146)

OBJECTIVE: To investigate the harvest and application of hamstring grafts for canine cranial cruciate ligament (CrCL) reconstruction. STUDY DESIGN: Experimental study. ANIMALS: Four adult female hounds, weighing 26.3 +/- 1.6 kg (mean +/- SEM). METHODS-One stifle in each dog was randomly chosen for hamstring graft CrCL reconstruction after native CrCL transection. Arthroscopy was performed to evaluate graft integrity at 12 weeks. Gait analysis and stifle radiographs were performed preoperatively and up to 52 weeks after graft placement. Dogs were killed 12 (n = 2) or 52 weeks (n = 2) after CrCL reconstruction. Tissues were evaluated grossly and with light and confocal laser microscopy. RESULTS: Hamstring grafts were intact in all stifles at 12 weeks (n = 4) and 52 weeks (n = 2). Grossly, there was no osteoarthritis in stifles at 12 weeks and only chondrophytes along the trochlear ridges at 52 weeks. Minimal radiographic evidence of osteoarthritis developed in stifles with grafts during the study. Lameness in limbs with grafts resolved by 52 weeks. Graft tissue was highly vascular, ligamentized, and undergoing active remodeling at 12 weeks. Fifty-two weeks after graft placement, intraarticular graft tissue was well vascularized, mature, and encapsulated by synovium, and graft-bone interfaces were characterized by Sharpey's fiber insertions. There was no evidence of graft necrosis using confocal laser microscopy at either time point. CONCLUSIONS: The hamstring graft technique may be a viable method of canine CrCL reconstruction. CLINICAL RELEVANCE: Hamstring grafts may be an alternative technique for canine CrCL reconstruction. Further study is needed before clinical application.  (+info)

Basic fibroblast growth factor mediates transduction of mechanical signals when articular cartilage is loaded. (8/146)

OBJECTIVE: To determine whether the basic fibroblast growth factor (bFGF) mediates signal transduction in articular cartilage in response to mechanical loading. METHODS: Articular cartilage from porcine metacarpophalangeal or knee joints was cyclically loaded (62.5-250N) for 2 minutes in the absence or presence of a bFGF receptor inhibitor, SB 402451 (250 nM). Activation of the extracellularly regulated kinase MAP kinase ERK was measured by Western blot analysis. Changes in protein synthesis were assessed by measuring the incorporation of (35)S-Met/Cys into proteins secreted by cartilage explants or by isolated chondrocytes. RESULTS: Rapid activation of the ERK MAP kinase occurred when articular cartilage was loaded. This was dependent upon release of the bFGF because it was restricted by the FGF receptor inhibitor. Loaded explants were shown to release bFGF. Loading or bFGF stimulation of explants induced synthesis and secretion of tissue inhibitor of metalloproteinases 1 (TIMP-1), which was inhibited by SB 402451. CONCLUSION: Cyclical loading of articular cartilage causes bFGF-dependent activation of ERK and synthesis of TIMP-1.  (+info)

  • The cranial cruciate also resists over-extension and inward rotation, and is the most commonly damaged stifle ligament in dogs. (
  • Radiographic evidence of arthritis, cranial tibial translation, and arthroscopic synovitis were increased in unstable stifles, when compared with stable contralateral stifles in CrCLR dogs ( P (
  • Histologic evidence of synovitis was identified in all CrCLR dogs, but was only significantly correlated with arthroscopic observations in stable stifles (r 2 =0.57, P (
  • The MRI of a normal left stifle of a dog was performed on a 1.5T MRI by by Dr. Susanne AEB Boroffka, dipl. (
  • The equine stifle model seems to most closely approximate the human knee cartilage wise (McIlwraith, 2011). (
  • Nevertheless, there is no universal model for (osteo-)chondral defect surgery for cartilage repair in the equine stifle. (
  • Development of a standardized surgical (osteo-)chondral defect model in the equine stifle. (
  • Since tens of thousands of Russians protested in late 2011 against what they termed election fraud, the Kremlin has relied on harassment, prosecution and anti-protest laws to stifle the opposition, the Los Angeles Times reported. (
  • WE have a yearling who on occasion has been seen with his right hind completley locked behind him from stifle down (picture a horse stretching his hind leg straight back and it staying there) when he tries to pull it forward while walking it doesnt move. (
  • ACVS, Assistant Professor of Equine Surgery at the University of California, Davis, 'The femorotibial joint cavity of the stifle is further subdivided into medial and lateral (inside and outside) compartments. (
  • The Angolan government needs to stop trying to stifle peaceful protests, gag the independent press, or use the state media for partisan purposes if these elections are to be meaningful. (
  • The offense was clicking for the Wreckers and their defense was stifling with Gallagher and senior Frankie Bergonzi thwarting any and all attempts by the Falcons. (
  • It will stifle economic growth and I already believe it is,' said Dimon, who was speaking at the annual spring meeting of the Council of Institutional Investors. (
  • Misuse of the "hot news" doctrine could stifle this extraordinary growth of free expression. (
  • The stifle joints may become swollen and stiff (Trostel et al 2002). (
  • Labrador retrievers are predisposed to stifle osteochondrosis (Necas et al 1999, LaFond et al 2002) but we are unaware of data on the proportion of animals that are affected. (
  • A stifling problem Introduction to the types of joints in horses. (
  • Young horses with both stifles affected may become slightly roach-backed and have difficulties in getting up after laying down. (
  • The brand new custom-designed equine computed tomography (CT) table and a commercial Big Bore scanner make it possible to image the entire neck and stifles in horses.The RVC Equine CT scanner is 10 cm wider than a standard CT, allowing us to image the entire cervical spine, often up to the level of the thoracic vertebrae and the limb up to and including the stifle. (
  • WE have a yearling who on occasion has been seen with his right hind completley locked behind him from stifle down (picture a horse stretching his hind leg straight back and it staying there) when he tries to pull it forward while walking it doesnt move. (
  • Myanmar's authorities are intensifying restrictions on media as the country approaches crucial national elections, scheduled to be held in November, using threats, harassment and imprisonment to stifle independent journalists and outlets, Amnesty International said in a new briefing today. (
  • Trauma and several different diseases can affect the stifle. (
  • We usually divide stifle diseases into two main categories-acquired disorders and developmental disorders,' states John F. Peroni, DVM, MS, Assistant Professor of Large Animal Surgery at the University of Georgia. (
  • Developmental stifle diseases are congenital (present at birth) and might or might not be caused by genetic abnormalities. (
  • The Saudi authorities must end their repeated moves to stifle people's attempts to protest against the widespread use of arbitrary detention in the country," declared Philip Luther, Director of Amnesty's Middle East and North Africa Programme. (
  • Such plots were a major obstacle for reconstruction efforts after the 2011 tsunami, and experts warn it could stifle any recovery efforts should Japan suffer another major natural disaster. (
  • They discovered air bubbles in his neck and chest and determined that the stifled sneeze had torn a hole in the lower part of his throat. (
  • By visualising lesions accurately, we are able to improve our understanding of neck and stifle pathologies, treat lesions more precisely and develop new treatment methods for the future. (
  • If you've ever tried to stifle a sneeze by pinching your nose and closing your mouth, doctors are offering a cautionary tale for why you should stop. (
  • Whoever the moderator is will be under orders to stifle Romney and to cut short answers to questions or reactions to Obama. (
  • In a nutshell, it's that we're all born with immense natural talents but our institutions, especially education , tend to stifle many of them and as a result we are fomenting a human and an economic disaster. (
  • HONG KONG (Reuters) - Macau, the world's largest gambling hub, re-elected its leader and sole candidate Fernando Chui on Sunday, a widely expected result after the pro-China government stifled an unofficial referendum on democracy. (
  • This case, and others we have brought and will bring," stated Timothy J. Muris, Chairman of the Federal Trade Commission, "stands for an important proposition: competition must be on the merits, not through misusing the government to stifle your competition. (