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1.
REASONS FOR PERFORMING STUDY: The developmental pattern of the cartilage canal blood supply to epiphyseal growth cartilage has been linked to osteochondrosis (OC) in the tarsus of foals. This pattern has not yet been described in the distal femur, another site frequently affected by OC. OBJECTIVE: To describe the developmental pattern of the blood supply to the distal femoral epiphyseal growth cartilage in 8 Standardbred foals age 0-7 weeks. METHODS: One foal was sacrificed weekly from birth to age 7 weeks (n=8) to undergo a barium perfusion procedure to demonstrate vessels within cartilage canals of one hindlimb. The distal end of the femur was cleared in methyl salicylate and perfused vessels were studied in the intact bones. Each distal femur was then sawed into 5 mm thick slabs in the transverse plane, and the slabs decalcified and radiographed. Finally, the lateral trochlear ridge was separated from each slab and examined histologically. RESULTS: The cartilage canal blood supply regressed with increasing age, but several regions remained vascularised in the oldest foal at age 7 weeks. Vessels arose from perichondrial and subchondral arterial sources, and coursed perpendicular or parallel to the ossification front. The midsection of parallel vessels became incorporated into the ossification front during growth. Anastomoses formed and vessels within the distal portion of canals with an original perichondrial source shifted to use subchondral vessels as their arterial source. Both parallel and perpendicular vessels therefore traversed the ossification front to enter cartilage canals. No histological lesions were observed in sections from any of the foals. CONCLUSION: The same anatomical feature (traversing the ossification front to enter cartilage canals) reported to render vessels vulnerable to failure in the tarsus was also present in the distal femur of foals. POTENTIAL RELEVANCE: OC may occur by the same pathogenetic mechanism in the distal femur as in the tarsus of foals. 相似文献
2.
K. OLSTAD B. YTREHUS S. EKMAN C. S. CARLSON N. I. DOLVIK 《Equine veterinary journal》2009,41(9):865-871
Reasons for performing study: It is presently unknown whether cartilage ischaemia plays any part in the pathogenesis of osteochondral fragmentation within the equine metatarsophalangeal joint, as no detailed studies on microcirculation in the area have been reported. Objective: To describe the developmental pattern of the blood supply to the epiphyseal growth cartilage in the metatarso‐phalangeal joint of foals. Methods: Eight Standardbred foals were sacrificed between birth and age 7 weeks to undergo a barium perfusion procedure to demonstrate vessels within growth cartilage canals of one hindlimb. The metatarso‐phalangeal joint was cleared in methyl salicylate and perfused vessels studied in the intact bones. The bones were sawed into 5 mm thick slabs, decalcified and radiographed. Selected slabs were cleared in methyl salicylate for a second time and examined at low magnification. The dorsal half of the sagittal ridge of the distal third metatarsal bone and the plantar half of the proximal phalanx were examined histologically. Results: Regions of the epiphysis with thick cartilage contained a greater number of perfused vessels than regions with thin cartilage. The cartilage canal vessels were oriented either parallel or perpendicular to the underlying ossification front. Cartilage canal vessels were incorporated into the ossification front during growth and became reliant on a subchondral arterial source. Macroscopically visible lesions were not detected in the current group of foals. On histological examination, pathological changes consisting of an area of chondronecrosis surrounded by fibrovascular granulation tissue were found in sections from the lateral proximo‐plantar eminence of the proximal phalanx in the 7‐week‐old foal. Conclusion: The same anatomical feature (traversing the ossification front to enter cartilage canals) reported to render vessels vulnerable to failure in the tarsus was also present in the metatarso‐phalangeal joint of foals. Potential relevance: Osteochondrosis may occur by the same pathogenetic mechanism in the metatarso‐phalangeal joint as in the tarsus of foals. 相似文献
3.
Failure of the cartilage canal blood supply to epiphyseal growth cartilage has been implicated in the pathogenesis of articular osteochondrosis in horses and other animal species. In a previous study of the developmental pattern of the blood supply in the tarsus of foals, early lesions of osteochondrosis were consistently found in regions where the cartilage canal vessels traversed the chondro-osseous junction. The developmental pattern of blood vessels has also been described in the distal femoral epiphysis; however, the group of foals examined in that study did not have lesions of osteochondrosis in this location. Therefore, the relationship between the occurrence of early lesions of osteochondrosis and the developmental pattern of the blood supply to epiphyseal growth cartilage in this site in foals has not been examined. Distal femora were collected from 30 fetuses and foals (up to 11 months old) submitted for postmortem examination. Sections from the lateral trochlear ridge and medial femoral condyle of both hind limbs were examined histologically. Sixteen cartilage lesions were found in 7 of the 30 fetuses and foals. All lesions contained evidence of cartilage canal necrosis and ischemic chondronecrosis. The lesions were located in regions where cartilage canal vessels traversed the chondro-osseous junction, as previously observed in the tarsus. The location and morphology of lesions indicated that a subclinical stage of ischemic chondronecrosis existed that preceded and predisposed to the development of osteochondrosis dissecans and subchondral bone cysts. 相似文献
4.
Lecocq M Girard CA Fogarty U Beauchamp G Richard H Laverty S 《Equine veterinary journal》2008,40(5):442-454
REASONS FOR PERFORMING STUDY: The earliest osteochondrosis (OC) microscopic lesion reported in the literature was present in the femorotibial joint of a 2-day-old foal suggesting that OC lesions and factors initiating them may arise prior to birth. OBJECTIVE: To examine the developing equine epiphysis to detect histological changes that could be precursors to OC lesions. METHODS: Osteochondral samples from 21 equine fetuses and 13 foals were harvested from selected sites in the scapulohumeral, humeroradial, metacarpophalangeal, femoropatellar, femorotibial, tarsocrural and metatarsophalangeal joints. Sections were stained with safranin O and picrosiruis red to assess cartilage changes and structural arrangement of the collagen matrix. RESULTS: Extracellular matrix changes observed included perivascular areas of paleness of the proteoglycan matrix associated with hypocellularity and, sometimes, necrotic chondrocytes. These changes were most abundant in the youngest fetuses and in the femoropatellar/femorotibial (FP/FT) joints. Indentations of the ossification front were also observed in most specimens, but, most frequently, in scapulohumeral and FP/FT joints. A cartilage canal was almost always present in these indentations. The vascular density of the cartilage was higher in the youngest fetuses. In these fetuses, the most vascularised joints were the metacarpo- and metatarsophalangeal joints but their cartilage canals regressed quickly. After birth, the most vascularised cartilage was present in the FP/FT joint. Articular cartilage differentiated into 4 zones early in fetal life and the epiphyseal cartilage also had a distinct zonal cartilage structure. A striking difference was observed in the collagen structure at the junction of the proliferative and hypertrophic zones where OCD lesions occur. CONCLUSION: Matrix and ossification front changes were frequently observed and significantly associated with cartilage canals suggesting that they may be physiological changes associated with matrix remodelling and development. The collagen structure was variable through the growing epiphysis and a differential in biomechanical properties at focal sites may predispose them to injury. 相似文献
5.
Articular cartilage blood vessels in swine osteochondrosis 总被引：1，自引：0，他引：1
Perfusion studies in swine with early lesions of osteochondrosis demonstrated that lamellar areas of chondrocyte necrosis within reserve zones of growth areas occurred only in regions of nonperfused articular cartilage. Articular cartilage with a similar anatomical location was perfused in some animals. Occasionally, nonperfused articular cartilage showed vascular alterations within cartilage canals without evidence of significant perivascular or lamellar necrosis. By light microscopy, some vessels within or adjacent to nonperfused articular cartilage had normal morphology; however, ultrastructural abnormalities were found in some vessels of all cartilage canals adjacent to necrotic cartilage lamella. Minimal alterations were in the few cartilage canal vessels that appeared normal by light microscopy, and the surrounding chondrocytes showed only minimal alterations. Early cartilage canal alterations were seen in the endothelium of cartilage canal capillaries, and ultrastructural changes in these vessels were similar to those described with experimentally induced, direct vascular injury. Vascular injury was followed by leakage of plasma and cells into the interstitial space of the cartilage canal. Necrosis of the vessel wall and interstitial tissue caused the cartilage canals to appear empty or to be filled with fibrin-like material. Although the vascular changes could be considered as part of the normal process of cartilage maturation and cartilage canal chondrification, observations suggest that in domestic swine the attendant cartilage necrosis and chondrolysis is exuberant. It is suggested that alterations in cartilage canal vessels play a major role in the pathogenesis of articular cartilage lesions that are found in osteochondrosis of swine. 相似文献
6.
《Journal of Equine Veterinary Science》1996,16(1):32-37
Osteochondrosis is one of the most important skeletalproblems affecting young horses and is one of the conditions included in the syndrome of developmental orthopedic disease. It occurs worldwide in many different breeds and its incidence appears to be steadily increasing. The primary lesion of osteochondrosis is attributed to focal damage of endochondral ossification. When occurring in the articular/epiphyseal cartilage complex, there may be bone formation within the retained cartilage, resulting in “bony fragments.” These are often seen in the tarsocrural articulation on the cranial aspect of the tibia. Focal retention of necrotic cartilage into the subchondral bone may eventually lead to cleft formation resulting in osteochondrosis dissecans. Other lesions associated with osteochondrosis are subchondral cysts, fractures and osteoarthrosis.The definitive cause of osteochondrosis is unknown,but there is evidence that it is the response in growth cartilage to a number of different challenges. It appears to be multifactorial in origin, involving heredity, growth rate, body size, nutrition, mineral imbalance, endocrinological dysfunction and biomechanical trauma. Recent studies have shown cases of osteochondrosis to be preceded by radiographically detectable disturbances of endochondral ossification during the first three months of life. This early appearance of disturbed ossification necessitates further studies into the importance of nutrition/management of the pregnant and lactating mare. Whether these early disturbances will lead to fully developed osteochondrosis or if they will recede obviously depends on a number of factors such as nutrition and exercise. High energy diets have been shown in weaning foals to consistently produce lesions of osteochondrosis. If, however, foals fed a high energy diet are subjected to forced exercise, the incidence of osteochondrosis is reduced dramatically.The prevention of osteochondrosis must rate as a highpriority for the horse industry, but to achieve this more data on the mechanisms of endochondral ossification and how this process is influenced by different intrinsic and environmental factors are required. Recent research into osteochondrosis has involved studies of chondrocyte metabolism in growth cartilage, the influence of growth factors, the extent of degradation of extracellular matrix and endochondral ossification. 相似文献
7.
The vascular features of the distal epiphysis of the radius of 27 foals aged from 3 weeks premature to 120 days postpartum were determined. The limbs were perfused with barium, and the distal radius was sawn into sagittal slabs which were decalcified, cut into thin slices and radiographed. More arteries approached areas of thick cartilage than thin cartilage. In thick cartilage, vessels in a lattice network were observed, and adjacent to these vessels was sinusoidal filling in the epiphyseal subchondral bone, which had a similar pattern to sinusoidal filling in the metaphysis. The sinusoidal filling adjacent to thick cartilage was at the predisposition site for epiphyseal osteomyelitis lesions in foals. This particular type of bone infection occurs commonly in the foal, but much less commonly in other species. The vascular features of the immature epiphysis may account for the predominance of epiphyseal osteomyelitis in the foal. 相似文献
8.
Gee EK Firth EC Morel PC Fennessy PF Grace ND Mogg TD 《New Zealand veterinary journal》2005,53(6):448-456
AIMS: To determine the influence of copper (Cu) supplementation by injection of mares in late gestation on the frequency and severity of osteochondrosis (OC) lesions in their foals at around 160 days of age. To determine if there was any influence of the concentration of Cu in the liver, growth rate, birthweight, weight at 160 days of age, fatness, sex, or year of birth of the foal on the frequency and severity of OC lesions. To determine the influence of dam's age, and sex and birthweight of the foal on the growth rate from birth to 160 days of age, and weight at 160 days of age. METHODS: Thirty-three Thoroughbred foals, born in two consecutive years, were weighed every 2 weeks from birth. The dams had been supplemented with parenteral Cu or saline during late gestation, and the supplementation regimens were different in each year. Foals had liver biopsies harvested at birth for determination of Cu concentration. Pasture samples were collected every 4-8 weeks for analysis of concentration of Cu and zinc (Zn). At 160 days of age, articular cartilage of long bones was examined. Gross lesions were counted and scored, then sawn and radiographed, and processed for histopathology. Lesions were given radiographic scores and histopathological scores. Maximum scores for each lesion were combined to give a total OC score for each joint and each foal. The fatness of 20 foals (10 each from Years 1 and 2) at 160 days of age was determined chemically. RESULTS: Supplementation of dams with Cu had no significant effect on the concentration of Cu in the liver of foals at birth, or on the frequency or severity of lesions in articular cartilage at 160 days of age. The Cu and Zn concentrations of pasture were similar in Years 1 and 2, and were lower than current recommendations. All foals in Year 2, and 9/10 foals in Year 1 had irregularities in cartilage that was confirmed histologically to be indicative of OC. The average number of lesions per foal was 4.7 (SD 1.1) and 5.7 (SD 1.1) in Years 1 and 2, respectively. However, the severity of the lesions was considered mild, and no foals showed any clinical evidence of OC while alive. The number of lesions in the tarsocrural (TC) joint and the TC OC score at 160 days were positively associated with average daily weight gain (ADG) in the previous 4 weeks (p=0.005 and p=0.001, respectively). There was no significant effect of sex, fatness, birthweight, weight at 160 days of age, or year of birth of the foal on the frequency and severity of OC lesions. CONCLUSIONS: Many of the lesions classified as OC, using classification systems described by other authors, were likely to be normal variations of the process of endochondral ossification. Despite the high frequency of such lesions, they were considered to be of minor significance and none were clinically evident. The distribution of lesions was not typical, and most probably reflected the subtlety of the lesions. These results support the hypothesis that Cu is an over-emphasised factor in the aetiopathogenesis of OC. The relationship between subtle macroscopic lesions and lesions resulting in clinical signs of disease requires further investigation. 相似文献
9.
EK Gee EC Firth PCH Morel PF Fennessy ND Grace TD Mogg 《New Zealand veterinary journal》2013,61(6):448-456
AIMS: To determine the influence of copper (Cu) supplementation by injection of mares in late gestation on the frequency and severity of osteochondrosis (OC) lesions in their foals at around 160 days of age. To determine if there was any influence of the concentration of Cu in the liver, growth rate, birthweight, weight at 160 days of age, fatness, sex, or year of birth of the foal on the frequency and severity of OC lesions. To determine the influence of dam's age, and sex and birthweight of the foal on the growth rate from birth to 160 days of age, and weight at 160 days of age. METHODS: Thirty-three Thoroughbred foals, born in two consecutive years, were weighed every 2 weeks from birth. The dams had been supplemented with parenteral Cu or saline during late gestation, and the supplementation regimens were different in each year. Foals had liver biopsies harvested at birth for determination of Cu concentration. Pasture samples were collected every 4–8 weeks for analysis of concentration of Cu and zinc (Zn). At 160 days of age, articular cartilage of long bones was examined. Gross lesions were counted and scored, then sawn and radiographed, and processed for histopathology. Lesions were given radiographic scores and histopathological scores. Maximum scores for each lesion were combined to give a total OC score for each joint and each foal. The fatness of 20 foals (10 each from Years 1 and 2) at 160 days of age was determined chemically. RESULTS: Supplementation of dams with Cu had no significant effect on the concentration of Cu in the liver of foals at birth, or on the frequency or severity of lesions in articular cartilage at 160 days of age. The Cu and Zn concentrations of pasture were similar in Years 1 and 2, and were lower than current recommendations. All foals in Year 2, and 9/10 foals in Year 1 had irregularities in cartilage that was confirmed histologically to be indicative of OC. The average number of lesions per foal was 4.7 (SD 1.1) and 5.7 (SD 1.1) in Years 1 and 2, respectively. However, the severity of the lesions was considered mild, and no foals showed any clinical evidence of OC while alive. The number of lesions in the tarsocrural (TC) joint and the TC OC score at 160 days were positively associated with average daily weight gain (ADG) in the previous 4 weeks (p=0.005 and p=0.001, respectively). There was no significant effect of sex, fatness, birth-weight, weight at 160 days of age, or year of birth of the foal on the frequency and severity of OC lesions. CONCLUSIONS: Many of the lesions classified as OC, using classification systems described by other authors, were likely to be normal variations of the process of endochondral ossification. Despite the high frequency of such lesions, they were considered to be of minor significance and none were clinically evident. The distribution of lesions was not typical, and most probably reflected the subtlety of the lesions. These results support the hypothesis that Cu is an over-emphasised factor in the aetiopathogenesis of OC. The relationship between subtle macroscopic lesions and lesions resulting in clinical signs of disease requires further investigation. 相似文献
10.
Weanling gilts were fed either a 12% or 16% protein diet for 10 weeks. Animals fed the 12% protein diet had reduced body weights and reduced longitudinal bone growth as measured in the distal radial growth plate. There was no difference in the growth plate widths between the two animal groups, but there was a significant reduction in the daily rate of cell production in the proliferative zone of animals fed the 12% protein diet. No effect of diet on the rate of expansion of the epiphysis at the articular-epiphyseal junction of the distal femur or humerus could be detected. All animals in both groups had morphologic cartilage lesions consistent with early changes associated with osteochondrosis (OCD), and there was no difference in the lesion morphology between the dietary groups. Areas of disorderly endochondral ossification in the radial growth plate were associated with perpendicular growth cartilage infractions. Growth plate lesions were characterized by increased widths of the maturing cartilage zone without increased width of the proliferative zone or an increase in the daily rate of cell production. Focal growth plate lesions developed because of a transitory inhibition of cartilage mineralization and resorption. Disorderly foci of endochondral ossification beneath articular cartilage were characterized by an area of chondrocyte necrosis which prevented normal cartilage matrix mineralization. Lamellae of cartilage necrosis were also present within the reserve zone of the articular cartilage. These were associated with abnormalities of the cartilage canal vessels, and chondrocyte necrosis was considered to precede degenerative changes in articular cartilage matrix.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
11.
Fifteen broiler fowls which habitually adopted a unilateral weight bearing stance were studied. In the majority of fowls the left pelvic limb was weight bearing and the right limb showed severe angular deformity. Dyschondroplasia occurred most frequently in the load-bearing limb. In the load-bearing limb the majority of lesions were in the femur and proximal tibiotarsus. In the non-load-bearing limb lesions most frequently occurred in the bone extremities of the distal tibiotarsus and proximal tarsometatarsus. Occluded epiphyseal vascular canals occurred in conjunction with physeal thickening at some dyschondroplastic sites. The majority of dyschondroplastic lesions contained elongated penetrating epiphyseal vessels and vessels derived from the perichondrial ring. These vessels were associated with chondrocyte hypertrophy and matrix calcification, which was considered to lead to the repair of the lesions. There was minimal calcification of cartilage at the base of the dyschondroplastic lesions and the underlying metaphyseal vessels were blunt ending. This suggested that a band of abnormal physeal cartilage was acting as a barrier to penetration by the metaphyseal vessels and so preventing subsequent endochondral ossification. 相似文献
12.
The effects of copper supplementation on the prevalence of cartilage lesions in foals 总被引：2，自引：0，他引：2
D A Knight S E Weisbrode L M Schmall S M Reed A A Gabel L R Bramlage W I Tyznik 《Equine veterinary journal》1990,22(6):426-432
The potential role of dietary copper in the development of cartilage defects in foals was investigated. Twenty-one mares were fed rations containing 13 ppm copper (CuC, control) or 32 ppm copper (CuS, supplemented) during the last three to six months of gestation and first three months of lactation. Their foals were fed pelleted concentrate containing 15 or 55 ppm Cu and were destroyed at 90 (5 CuC and 5 CuS foals) or 180 (6 CuC and 5 CuS foals) days. Focal cartilage lesions were found at multiple sites on necropsy. In foals killed at 90 days, there were over twice (9 versus 4) as many lesions of osteochondrosis and more than four times (9 versus 2) as many articular lesions of osteophyte formation or thinning in CuC foals compared with CuS foals. These differences were due predominantly to a higher number of lesions in one CuC foal. Two 90-day CuC foals had osteochondrosis of articular-epiphyseal (A-E) complex, one with thickenings and separation from subchondral bone and one with subchondral fibrosis. One 90-day CuS foal had a cartilage thickening of the A-E complex in the tibiotarsal joint with separation from subchondral bone. In foals killed at 180 days, there were seven times more articular lesions (21 versus 3) of osteophyte formation or thinning, nearly twice as many lesions of osteochondrosis (13 versus 8) [corrected] in the physis and over five times as many involving the A-E complex (11 versus 2) in six CuC foals compared with five CuS foals.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
13.
S R Duff 《Research in veterinary science》1984,37(3):310-319
Radiographs revealed defective endochondral ossification in proximal femora of 52 lame broilers. Cartilage retention either involved epiphyseal cartilage close to the articular surface or growth plate cartilage (dyschondroplasia). In at least seven birds proximal femoral lesions were the only abnormalities detected which could have caused lameness. In cases of moderate or severe cartilage retention, fracture lines traversed necrotic cartilage to undermine part or all of the femoral head. Evidence of reparative fibrosis was seen with augmentation of metaphyseal trabeculae by woven bone apposition. Foveal blood vessels aided repair by re-establishing a new ossification centre but in many cases attempts at repair were inadequate. 相似文献
14.
15.
B H Thorp 《Research in veterinary science》1988,44(1):89-99
Laying strain fowls were reared from hatching till 20 weeks old. Birds were killed throughout the growth period and specimens from the distal femur and proximal tibiotarsus prepared for study. The origin and nature of cartilage canals were established in the two bone extremities. The canals follow a pattern of development which was similar in fowls of the same age. Similarities were noted with the vascular patterns reported in other species. The epiphyseal ossification centre of the proximal tibiotarsus formed in an area extensively perfused by cartilage canals. Anastomoses occurred between epiphyseal vascular canals in association with the formation and growth of the epiphyseal ossification centre in the proximal tibiotarsus. Anastomoses between epiphyseal vascular canals did not occur at any other site. The development of the epiphyseal ossification centre in the proximal tibiotarsus suggests that this is a traction epiphysis. 相似文献
16.
Cartilage canals and lesions typical of osteochondrosis in growth cartilages from the distal part of the humerus of newborn pigs 总被引：1，自引：0，他引：1
Vessels in cartilage canals supplying the articular-epiphyseal cartilage complex and growth plate of the distal part of the humerus of pigs between on day and 15 weeks old were examined in perfused and cleared specimens, and histochemical preparations. An extensive capillary network surrounded the arterioles and venules and probably maintained the circulation of blood as the ends of the cartilage canals underwent involution. Pits and grooves were in predilection sites for osteochondrosis and osteoarthrosis and were typical of early lesions of these conditions. Some ghosts that were observed mesoscopically were chondrified cartilage canals or remnants of cartilage canals in histological sections, and were considered to be the result of a normal process. However, abnormal involution may predispose to chrondrolysis, and the presence of involuting transverse cartilage canals at predilection sites implicated damaged canals in the aetiopathogenesis of osteochondrosis and osteroarthrosis in some pigs. Cleared specimens provided the most useful demonstration of the form and distribution of cartilage canals, ghosts, and pits or grooves. The association of cartilage canals with areas of chondrolysis, and the distribution of ghosts in the predilection sites for lesions, warrant further investigation of blood vessels within cartilage canals. 相似文献
17.
A 2‐day‐old Warmblood filly was presented for examination of an angular limb deformity of the left front limb and an upright conformation of both metacarpophalangeal joints. Radiological examination revealed bilateral absence of the metacarpophalangeal joint space with fusion of the third metacarpal bone and first phalanx (synostosis). No treatment was undertaken. The filly was readmitted to the clinic 10 weeks later for bilateral front limb lameness. On radiological examination, the synostosis of the front metacarpophalangeal joints was still present. Physitis of the distal growth plate of the right third metacarpal bone and proximal growth plate of the right proximal phalanx, and an avulsion fracture of the palmaromedial and proximal aspect of the left middle phalanx, with a cystic like lesion on the medial aspect of distal first phalanx and proximal middle phalanx were diagnosed. Given the poor prognosis, the foal was subjected to euthanasia. Post mortem examination confirmed the absence of the metacarpophalangeal joint space with a trabecular bony union between the third metacarpal bone and the first phalanx. A rudimentary joint capsule was present at the level of the absent joints as well as a small zone of articular cartilage, which invaginated over a short distance into the dorsal trabecular bone on the right front limb. On the medial aspect of the left proximal interphalangeal joint, a focal defect of articular cartilage with exposure of subchondral bone was observed. This is the first case report of a foal born with congenital aplasia of both metacarpophalangeal joints. Congenital malformations should be considered as differential diagnosis in lame foals or foals born with angular or flexural limb deformities. 相似文献
18.
Ki-Dong Eom DVM PhD Hee-Chun Lee DVM MS Jung-hee Yoon DVM PhD 《Veterinary radiology & ultrasound》2000,41(3):231-234
Canalography was performed to measure the diameter of the horizontal ear canal and to assess the clinical relevance of the measurements in identifying abnormalities of the ear canal. The diameter of the proximal and distal end of the annular cartilage in the horizontal ear canal was measured using canalography in 222 ears. The tympanic membrane could not be visualized with otoscopic examination in 70 ears even after ear cleansing. These canals were classified as being stenotic. The diameter of the proximal annular cartilage in the stenotic canals ranged from 0.8 to 3.1 mm (mean = 2.6 +/- 0.8 mm). The proximal annular cartilage was consistently smaller in diameter than the distal annular cartilage. The ratio between the diameter of the proximal and distal annular cartilage varied between dogs. In stenotic ear canals (70 ears) the ratio was less than 0.65. Total ear canal ablations and histopathological analysis were performed in 70 ear canals classified as stenotic after canalography. Hyperplasia of the epidermal layer was found in 56 stenotic canals. Stenosis of the canal due to otitis externa was found in the other 14 canals. Three canals with severe otitis externa were also diagnosed with canalography as having a ruptured tympanic membrane. The results suggest that canalography can be used to measure the diameter of the horizontal ear canal and to assess whether or not the tympanic membrane is ruptured prior to conservative or surgical therapy. 相似文献
19.
Cathepsin K and cathepsin B were immunolocalised in equine osteoclasts (OC s) present in ex vivo cartilage/subchondral bone samples. Samples were obtained post mortem from the lateral trochlear ridge (LTR) of six horses and ponies aged between 303 days gestation to 8 months. Strong expression of cathepsin K was detected in OC s, particularly those located at the osteochondral junction, apparently involved in the resorption of calcified cartilage. Cathepsin K expression was also detected in hypertrophic chondrocytes and in the endothelial cells of some blood vessels penetrating the hypertrophic zone of cartilage. By contrast, cathepsin B was either absent or present at very low levels in OC s.Osteoclast-like cells (OCL s) were generated in vitro from bone marrow (BM), obtained from the femurs of one horse and two ponies. High levels of cathepsin K activity but only very low levels of cathepsin B activity were demonstrated in OCL s using fluorogenic substrates for these enzymes. The cathepsin K activity could be blocked by the general cysteine proteinase inhibitor, E-64, but not by the cathepsin B inhibitor, CA-074Me. The cathepsin B activity was completely blocked by both CA-074Me and E-64. Taken together, these results suggest that cathepsin K is more important than cathepsin B in the osteoclastic resorption of bone and calcified cartilage of developing equine long bones. Given the apparent importance of cathepsin K in equine endochondral ossification further investigation into the possibility that abnormal expression of this enzyme is involved in the pathogenesis of equine developmental orthopaedic disease is warranted. 相似文献