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Biomedical subjects

D C Van Sickle

Publications and source records attributed to D C Van Sickle.

At least 19 recordsLinked to original sources
PubMed2001

Cortical bone healing following laser osteotomy using 6.1 microm wavelength.

BACKGROUND AND OBJECTIVE: Use of laser wavelengths in the 6.1 microm (amide I) to 6.45 microm (amide II) regions and a macropulse width of 4.0 microseconds delivered by a computer-controlled delivery system have produced clean, deep cortical bone ablations with minimal collateral thermal injury and no char formation. The purpose of this study was to evaluate the healing of cortical bone following 6.1 microm wavelength laser osteotomy using a 4.0 microsecond pulse, and compare that response to the response of similar osteotomies made with a standard pneumatic surgical bone saw. STUDY DESIGN/MATERIALS AND METHODS: Sixteen mature rabbits were divided equally into 2, 4, 6 and 8-week post-surgical survival groups. A nitrogen driven sagittal bone saw and an FEL generating 6.1 microm wavelength in 4.0 microsecond macropulses of 22.5 +/- 2.5 mJ/pulse directed into a 200 microm diameter spot were used to make 6.6 mm linear cuts into rabbit tibial cortex, and the healing response over time was monitored. Bone saw cuts were made halfway through the thickness of the cortex. Laser cuts were directed by a computer-controlled delivery system, and were either partial or full thickness cortical cuts. Location of the cortical bone cuts (saw or laser, partial or full thickness cut, proximal or distal, medial right or medial left tibia) were randomly assigned. At each predetermined post-surgical time point, rabbits of the appropriate group were euthanized, and the tibias of each subject collected, processed for histologic evaluation, and analyzed by light microscopy. RESULTS: At 2 weeks post-surgery, bone saw cuts showed no evidence of a healing response, while both the partial and full laser cut sites were filled with trabecular bone and primitive bone marrow. By 4 weeks post-surgery, the bone saw cuts showed filling of the defect with trabecular bone and primitive marrow, and an intense osteonal remodeling of the original cortex adjacent to the cuts was evident. All laser cut defects were filled, reactive periosteal bone was being converted to osteons and consolidating, and secondary osteons were appearing in the original cortex. At 6 weeks following surgery, the bone saw defects were filed with a mixture of woven and lamellar bone. All laser defects were filled with lamellar osteons and woven bone, the osteons were remodeling from primary to secondary osteons. By 8 weeks following the surgery, all bone saw and laser cut specimens revealed complete healing. CONCLUSIONS: Histologic evaluation of osteotomy sites made in skeletally mature rabbit tibia using the 6.1 microm wavelength, 4.0 microsecond macropulse FEL, delivered at 6 Hz at the osteotomy site, reveals a healing response which is at least as good as the healing of bone saw osteotomies, and appears to proceed at a faster rate during the first 2-4 weeks following surgery.

Animals↗
PubMed1999

Radionuclide studies of articular cartilage in the early diagnosis of arthritis in the rabbit.

The compound Se-75 bis[beta-(N,N,N-trimethylamino-)ethyl]selenide diiodide (Se-75 BISTAES) has been synthesized and its biodistribution in rabbits studied. A high uptake of radioactivity is found in the knee cartilage. Good scans of the knee are obtained by nuclear scintigraphy at 15 minutes after the injection of Se-75 BISTAES. The results of an equilibrium dialysis study show that Se-75 BISTAES binds to chondroitin sulfate and the binding is directly proportional to the chondroitin concentration. It appears that Se-75 BISTAES or its derivative should have potential as an articular imaging agent.

Animals↗
PubMed1997

Improved osseointeraction of calcium phosphate-coated external fixation pins. Studies in calves.

We investigated osseointeraction of solution-precipitated calcium phosphate (SPCP)-coated transfixation pins used in external skeletal fixation of a calf stable fracture model. One group (SPCP) received centrally-threaded transfixation pins which had SPCP coating; the other group (control) received identical, but not coated, pins. Radiographs were obtained 1 and 40 days after surgery and examined for evidence of osteolysis. Bone phase 99mTc-MDP studies were performed 6 and 28 days after surgery. Calves were killed 40 days after surgery and mechanical tests performed. Dual-energy x-ray absorptiometry (DEXA) and histomorphometric analyses were done. A smaller proportion of SPCP pins (5/24) had evidence of discharge during the study compared with control pins (21/24). A smaller proportion of SPCP pins (4%) had radiographic evidence of osteolysis compared with control pins (42%). Uptake of 99mTc-MDP was similar for SPCP and control calves. Uptake was significantly greater in bone segments showing radiographic evidence of osteolysis than in bone segments not having osteolysis. Yield stress (MPa) for axial displacement was similar in the treatment groups. Bone mineral density was less in SPCP pins. Affinity index and interface histologic score were greater and osteoclastic index less in SPCP calves. Coating of transfixation pins with solution-precipitated calcium phosphate improved the osseointeraction of pin and bone during this 40-day study.

Absorptiometry, Photon↗
PubMed1991

Cartilage canals and lesions typical of osteochondrosis in growth cartilages from the distal part of the humerus of newborn pigs.

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.

Animals↗
PubMed1990

The development of centres of ossification of bones forming elbow joints in young swine.

Epiphyseal centres of ossification in the bones forming the elbow joints of pigs between one day and 15 weeks of age were examined radiographically, macroscopically, mesoscopically and microscopically. Thoracic limbs from 39 pigs were perfused with India ink or silicone rubber injection compound and the bones were dissected free of soft tissues. The humerus, ulna and radius were fixed in formalin or ethyl alcohol and then cleared by the modified Spalteholz technique. Bones were radiographed, examined grossly, and then cut into slabs for mesoscopical evaluation. Foci considered to be calcifying within cartilaginous anlage were selected for microscopical examination. It was concluded that the epiphyseal centre of ossification develops at different times in different sites in the bones forming the elbow joint. Centres of ossification are initiated when foci of chondrocytes adjacent to one side of a cartilage canal undergo hypertrophy and the inter-territorial matrix becomes calcified. Osteogenesis then proceeds in the calcified focus, presumably with osteoprogenitor cells that originate within the cartilage canals. Subsequently, each epiphyseal centre of ossification enlarges by one of two methods. Firstly, the layer of cartilage adjacent to the centre undergoes endochondral ossification, thus allowing for the circumferential growth of the epiphyseal centre of ossification. Secondly, foci of calcification develop adjacent to the ends of cartilage canals near the epiphyseal centre of ossification and eventually the focus of calcification coalesces with the developing epiphyseal centre of ossification, thus establishing a new ossification front. Endochondral ossification continues at the periphery of the mass of bone. Mesoscopical examination is more useful than radiographical evaluation for identifying small foci of calcification which precede epiphyseal centres of ossification.

Animals↗
PubMed1989

Prostaglandins in inflammatory bone pathology: mechanism and therapeutic benefit of etodolac.

To investigate the role of PGE2 in the development of bone and joint pathology in rat adjuvant arthritis, hindlimb paws were evaluated by calcified tissue histologic techniques focusing on histochemical visualization of cartilage and bone lesions. Case studies of hindlimbs from normal, adjuvant arthritic, and etodolac-treated arthritic rats demonstrated the association of disease severity with inflammation, chondromalacia, replacement of adipose bone marrow with a fibroid marrow, osteoclastic bone resorption, synovial cysts, and pannus formation within the joints. Extensive periosteal intramembranous bone formation was temporally associated with joint destruction and medullary tissue pathology. In vivo data were correlated with in vitro effects of inflammatory mediators (IL-1, PGE2) on bone resorption. Etodolac blocked bone explant PGE2 accumulation at concentrations of 10(-7) M and higher, and inhibited bone resorption at concentrations of 10(-5) M and higher. The data indicate that in vitro and in vivo models of bone metabolism are well correlated regarding prostaglandin synthesis; that the inflammatory mediator PGE2 is largely responsible for the involvement of skeletal tissue in the adjuvant arthritis model; and that the effects of etodolac are specifically mediated by its ability to inhibit PGE2 accumulation in vivo.

Animals↗
PubMed1989

The biodistribution of [75Se]bis-[beta-(N,N,N-trimethylamino)ethyl]selenide diiodide in adult guinea pigs.

The biodistribution of [75Se]BISTAES was studied in guinea pigs. A higher concentration of radioactivity was observed in articular cartilage than in other tissues or organs. A minimal amount of radioactivity was found in the blood, muscle and bone. The compound was excreted rapidly in urine. The target to background ratios were encouraging. [75Se]BISTAES has potential as an articular cartilage imaging agent and further studies in osteoarthritic animals are merited.

Animals↗
PubMed1989

The vascular supply of the chondro-epiphyses of the elbow joint in young swine.

The vasculature of the elbow joint was examined in 39 pigs between one day and 15 weeks of age. Each pig was anaesthetised, exsanguinated and the thoracic limbs were perfused with India ink or a silicone rubber injection compound. The humerus, ulna and radius were dissected free, examined, fixed in formalin or ethyl alcohol, cleared by the modified Spalteholz technique and examined mesoscopically. Features of interest were photographed and then a limb from two pigs in each age group was cut into slabs and examined mesoscopically. The vascular supply of the distal part of the humerus was complex. It was supplied by vessels on both the cranial and caudal aspects and locally each aspect had a dual blood supply. Vessels anastomosed and on the cranial aspect formed a vascular ring. The proximal part of the ulna was supplied by vessels that were on its medial and lateral surfaces. The vessel on the lateral surface continued distally and supplied the lateral aspect of the proximal part of the radius. The proximal part of the radius was also supplied by arteries that were on the cranial and medial surfaces. Blood vessels provided branches to numerous cartilage canals of the articular-epiphyseal cartilage complexes, epiphyseal centres of ossification, and growth plates. The patterns of blood vessels in cartilage canals which were in sagittal or transverse planes were best exemplified by those in the distal part of the humerus. Perforating cartilage canals emerged from the epiphyseal centres of ossification. The pattern of cartilage canals was consistent in a general configuration, but individual variation did occur. Although cartilage canals were abundant in the youngest pigs, with increasing age the distribution of cartilage canals changed and the numbers of cartilage canals decreased.

Animals↗
PubMed1987

Histochemical morphologic features of growth cartilages in long bones of pigs of various ages.

Growth cartilages were obtained from humeri, femora, and ulnae of 31 pigs between 1 and 169 days old. On the basis of stain uptake and distribution, distinct layers were identified in articular-epiphyseal cartilage complexes and growth plates. The laminated appearance was dependent on stain uptake by territorial and interterritorial matrices and was more distinct in pigs greater than 15 days old. There was morphologic heterogeneity, which probably represented a functional heterogeneity, among chondrocytes in all layers and zones of both types of growth cartilage. The laminar appearance of growth cartilages and the distribution of different types of cells were similar for all pigs in each age category and for all sites.

Aging↗
PubMed1985

A Walker 256 tumor-induced osteogenic small animal model for the evaluation of [99mTc] diphosphonate radiopharmaceuticals.

A mammalian model has been developed for the in vivo evaluation of bone imaging agents. The model is based upon the quantification of a discrete, initial secondary periosteal osteogenesis induced in cortical bone immediately adjacent to an intramuscularly implanted Walker 256 tumor in Fisher 344 rats. Evaluation of the model consists of a histopathological examination of the periosteal bone formation, biodistribution studies on 99mTc-MDP and 99mTc-HMDP commercial kit preparations, and biodistribution studies on two 99mTc-HEDP component fractions isolated after anion exchange chromatographic separations from an investigative "carrier added" preparation. Reversed phase HPLC separations of the 99mTc-MDP and 99mTc-HMDP commercial kit preparations illustrate distinct differences in chemical composition between the two bone agents.

Animals↗
PubMed1982

Effects of exercise on the histochemical changes of articular chondrocytes in adult dogs.

Effects of exercise regimens on the enzyme histochemical changes of articular chondrocytes of the humeral heads in adult shepherd-type dogs were studied. One group of 4 dogs was exercised by walking on a flat surface 5 days a week for 6 months. A 2nd group of 4 dogs was exercised under the same conditions, except that the dogs were forced to walk over platforms placed in their path. Three control dogs were exercised ad libitum in their housing area. In all dogs, the reactivity of lactic acid dehydrogenase was quite strong nicotinamide dinucleotide dehydrogenase was moderate, and glucose-6-phosphatase was week. Succinic acid dehydrogenase uridine diphosphate (UDP)-galactose-4-epimerase, and UDP-N-acetylglucosamine-4-epimerase were of weakly moderate staining reactivity. Consistent regional or laminar variability was not found among the chondrocytic populations of the exercised and control groups for the reactivity of the enzymes studied. However, regional and/or laminar variabilities in individuals of the experimental groups were identified. The weak reactivity of glucose-6-phosphatase as seemingly contradictory to the presence of intracellular lipids of adult articular chondrocytes. Lipid synthesis was suggested as a mechanism to store excessive quantities of hydrogen ions in an innocuous form, rather than in the potentially deleterious by-product of anaerobic glycolysis, lactic acid.

Animals↗
PubMed1982

Developing coxal joint of the dog: gross morphometric and pathologic observations.

The growth and development of the proximal parts of femurs and the acetabula were studied in 32 English Pointers. The dogs were allotted to 8 age groups, birth through 9 months of age. Dogs were euthanatized, and at necropsy, 6 linear measurements were made on the proximal part of each femur: the cranial-caudal and the dorsal-ventral diameters of the femoral head, and the widths of the articular surface of the head from the center of the fovea to the cranial, caudal, dorsal, and ventral articular margins. Also 7 linear measurements were made on each acetabulum, including the cranial-caudal and the dorsal-ventral diameters, the length and width of the acetabular fossa, and the width of the lunate surface from the acetabular lip to the acetabular fossa in 3 places. All of the linear values increased rapidly during the first 4 weeks of life and slowly thereafter, and most of them increased simultaneously and proportionately. By 9 months of age, average body weight had increased by a factor of 52 (from initial 0.4 kg to 20.9 kg) and the diameter of the femoral heads and acetabula had increased by a factor of 4.5. Other coxal joint features were also evaluated, including the relative thickness of the joint capsule, the presence of fraying or disruption of the ligament of the femoral head, and the smoothness and regularity of the articular surfaces. Coxal joints in the younger dogs were free of grossly detectable pathologic changes. However, abnormalities of various joint components were present in 1 of the 6 dogs in the 5-month age group, in 2 of the 6 dogs in the 7-month age group, and in 4 of the 6 dogs in the 9-month age group.

Acetabulum↗
PubMed1981

Experimentally induced arthritis of the equine carpus: histologic and histochemical changes in the articular cartilage.

Arthritis was experimentally induced in the intercarpal joints of a series of mature ponies by the intraarticular injections of 400 microgram of the polyene antibiotic filipin in 1 ml of dimethyl sulfoxide. Twelve consecutive weekly injections were administered and the ponies were euthanatized 4 weeks after the last injection of filipin was made. The ponies were exercised for 1 hour each day throughout the experiment. Articular cartilage specimens from 4 sites in each intercarpal joint were examined histologically and histo-chemically. For the histochemical examination, safranin O-fast green, Alcian blue in 0.4 M and 0.9 M MgCl2 and Alcian blue 0.9 M MgCl2-Van Gieson matrical staining techniques were used. Decalcified sagittal sections of selected carpi were also examined histologically. There was superficial fibrillation with chondrocyte necrosis in the articular cartilage specimens of the joints. This was accompanied by loss of histochemical staining of the amorphous intercellular matrix, which was attributed to loss of glycosaminoglycans. There were hypertrophy of remaining chondrocytes and chondrone formation. On examination of decalcified sections of carpi, both exostoses and marginal osteophytosis was observed. There was evidence of both intramembraneous and endochondral osteogeneses in the exostoses. The pathologic changes seen in the experimental model were compared with those observed in the naturally occurring disease. It was concluded that the changes were comparable with the early changes of degenerative joint disease in the horse.

Alcian Blue↗
PubMed1980

Ultrastructure of timed isolates of in vitro canine articular chondrocytes.

Articular chondrocytes were enzymatically isolated from the distal end of the adult canine femur. The digestion procedure was conducted for 2- or 6-hour intervals, using 0.25% trypsin and 0.25% collagenase. Cells grown from the 2-hour digestion procedure were polygonal to stellate, had large vesicular nuclei with prominent nucleoli, and exhibited contact inhibition at confluency. Cells grown in cultures from the 6-hour digestion procedure were fusiform, had prominent nuclei with numerous nucleoli, and lacked contact inhibition. Cell cultures established, using cells from both procedures, were examined using the transmission electron microscope. Ultrastructurally, an extensive granular endoplasmic reticulum, prominent golgi complexes, and numerous autophagic vacuoles characterized the 2-hour cell population. The fine structures of the cells grown from the 6-hour process were characterized by numerous cytoplasmic microfilaments randomly dispersed and marginated beneath the plasmalemma of the cells. An extensive dilated rough-endoplasmic reticular system was present. The chondrocytes described in the present study provided morphologic evidence of a heterogeneous cell population in adult canine articular cartilage.

Animals↗
PubMed1978

Fetal effects of cadmium in pregnant rats on normal and zinc deficient diets.

This investigation has shown that not only the extent of fetal resoprtion and malformation but also the types of malformation seen in rats depend upon the strain used and day of gestation. Furthermore, the effects of zinc deficiency and cadmium administration on the fetus can be at least additive, as was seen for malformations. For fetal resorption, zinc deficiency potentiated the action of cadmium.

Abnormalities, Drug-Induced↗