Search PubMed⌕ Search

Biomedical subjects

E D Roberts

Publications and source records attributed to E D Roberts.

At least 37 records · Page 2Linked to original sources
PubMed1991

Arthritis in rhesus monkeys experimentally infected with simian immunodeficiency virus (SIV/DELTA).

The joint tissues from 36 rhesus (age 2-5 years) infected with SIV/Delta were graded into four groups and then correlated with the following systemic immunologic parameters: numbers of CD4+, CD4+ plus CD29+, and CD20+ cells and SIV/Delta antigenemia. Grade I (n = 16) consisted of normal synovial membrane; grade II (n = 8) consisted of synovial hyperplasia; grade III (n = 8) consisted of a mononuclear cell infiltrate, and grade IV (n = 4) consisted of synovial membrane infiltration of syncytial cell and mononuclear type cells. Synovial membranes from 20 uninfected age-matched rhesus were compared with infected animals and were graded 1. Immunostaining of the tissue phase lymphocytes and viral antigen was performed using monoclonal antibodies commercially available and a monoclonal antibody produced against a core protein of the SIV/Delta agent. SIV/Delta infection resulted in a reduction in cells doubly stained for CD4+ and CD29+ and a relative increase in CD8+ stained cells. A significant (ANOVA) difference was not observed in CD4+, CD4+ plus CD29+, CD8+, or CD20+ among the various grades of arthritis. Viral antigen was demonstrated in syncytial cells of the grade IV reaction. This finding suggests that the SIV/Delta arthritis is a primary viral reaction.

Animals↗
PubMed1990

The influence of stress treatment on femur cortical bone porosity and medullary bone status in Japanese quail selected for high and low blood corticosterone response to stress.

1. Femurs taken from Japanese quail (Coturnix coturnix japonica) genetically selected for either exaggerated (HS; high-stress) or reduced (LS; low-stress) blood corticosterone (B) response to unfamiliar environments were examined to determine their cortical bone porosity (CBP; degree of osteoporosis) and medullary bone (MB) status following treatment with or without stress. 2. Femur CBP was elevated in both sexes of stressed, HS-line quail and was attributed directly to the presumably exaggerated blood B responses known to occur in this line as a consequence of the stress treatments used. 3. The increase in CBP in stressed, HS-line birds occurred independently of changes in the numbers of osteoclast cells (CLASTS) associated with cortical bone. 4. Stress treatment was associated with lower CLAST numbers/mm2 of MB and with increased MB accretion. 5. These stress-induced effects were considered to be the consequence of a reduced rate of lay found in stressed quail hens. 6. There was only marginal evidence for a direct effect of B in stimulating MB resorption.

Analysis of Variance↗
PubMed1989

Macroscopic, microscopic and ultrastructural findings in experimental haemarthrosis of rhesus monkeys.

The effects of a single episode of massive haemarthrosis in rhesus monkeys were studied morphologically. Autologous whole blood was injected into a femorotibial joint of 16 anaesthetized monkeys, equally divided into four groups and killed 7 days, 2, 3 and 6 months post injection (PI). Synovial membrane and articular cartilage were examined for macroscopic, microscopic and ultrastructural changes. Haemarthrosis was only evident in one monkey by 7 days PI. Slight yellow-brown discoloration of synovium and cartilage was evident in groups killed early after injection. Histologically, a hyperplastic and inflammatory reaction was present in the synovium at 7 days PI. Ultrastructural examination of synoviocytes in this group revealed numerous cytoplasmic vacuoles and prominent microplicae compatible with increased phagocytic activity. Erythrophagocytosis by synoviocytes was observed by light microscopy and confirmed by transmission EM. Results of scanning EM suggested that red cells might also pass through the synovial intima. Transmission EM also revealed mild degenerative changes in superficial chondrocytes. Rhesus monkeys reacted morphologically to haemarthrosis in the same way as dogs and rabbits, with mild morphological changes that resolved by 2 months PI.

Animals↗
PubMed1989

Morphometric evaluation of rhesus articular cartilage: correlation of hexosamine and 35SO4 = incorporation.

Morphometric evaluation of 20 rhesus articular cartilage samples were correlated with hexosamine and an 18-hour incorporation of 35SO4- as a measure of proteoglycan production on samples from the same joint. Reduced chondrocyte cellularity was the basis of the reduced maintenance of the matrix by the chondrocyte. In the more cellular cartilage, the matrix/lacunae area ratio was less than 25, and the less cellular group had a ratio of greater than 40. An inverse correlation existed between morphometric cartilage matrix/lacunar area ratio and hexosamine content. A significant difference of 35SO4 incorporation was not seen between the three morphometric grades. Morphometric assessment reduces the subjectivity of articular cartilage evaluation.

Animals↗
PubMed1989

Experimental arthropathy induced in rhesus monkeys and DBA/1 mice by a novel method: intraperitoneal implantation of type II collagen adsorbed onto nitrocellulose filters.

A novel method which avoids the use of complete Freund's adjuvant (which can be arthritogenic) has been used to induce collagen II arthritis in both primates and mice. A solution of bovine type II collagen was dried onto nitrocellulose filters and implanted in the peritoneal cavity of experimental animals. Primate and mouse joints were scored by clinical as well as gross and microscopic parameters. The polyarthritis that developed in both rhesus monkeys (Macaca mulatta) and DBA/1 LAC J mice was characterized by synovial cell proliferation and endothelial cell hyperplasia, and by a perivascular mononuclear cell infiltrate of the synovium. Primates were analyzed further for anti-type II collagen antibody titers and delayed type hypersensitivity to type II collagen. Anti-type II collagen serum titers appeared to be unrelated to the disease pathology; the primates did not display delayed-type hypersensitivity to type II collagen. Control monkeys and mice implanted with collagen-free nitrocellulose filters were normal upon clinical and histopathological analysis. This protocol offers the advantage of the induction of arthritis due solely to immunization with antigen.

Animals↗
PubMed1988

Osteochondritis dissecans of the lateral ridge of the talus in a dog.

Osteochondral fragments, which originated from the proximolateral ridge of the talus, were discovered in an 8-month-old Rottweiler. A large fragment was reattached, using a lag screw and wire. Microscopic examination of a small fragment suggested the lesion resulted from osteochondritis dissecans. Stabilization of the major fragment resulted in acceptable joint function.

Animals↗
PubMed1988

Bone morphometrics and tetracycline marking patterns in young growing American alligators (Alligator mississippiensis).

Nine young American alligators (Alligator mississippiensis) were injected at monthly intervals with tetracycline to determine the bone apposition rate and the resorption patterns over a 3-mo period. The periosteal apposition rate increased progressively over the 3-mo period from 2.99 microns/day to 5.94 microns/day. Endosteal apposition rate was much slower with incomplete tetracycline lines being observed on the endosteum. This suggests that most modeling-resorptive activities occur on the endosteal envelope.

Alligators and Crocodiles↗
PubMed1987

Estradiol-17 beta-induced morphometric changes in chick embryo femurs.

The influence of exogenous estradiol-17 beta (E2) on chick embryo femur morphology was assessed. Fertile chicken eggs were air cell injected with 18.75, 37.5, or 75 micrograms E2/.1 ml distilled water: ethanol (7:3, v/v) on Days 10, 12, and 14 of incubation. Controls received vehicle only (.1 ml) on the same days. On Day 16 of incubation, right femurs were excised, and midshaft cross sections were examined by light microscopy. Structural differences were quantified using a computerized histomorphometric technique. Injection of E2 produced significant (P less than .01) dose-dependent elevations in mean femur total osseous tissue area, bone matrix area, percent of matrix surfaces covered by osteoblasts, and percent of matrix area occupied by osteocytes when compared with controls. Estradiol was ineffective in inducing medullary bone formation in chick embryo femurs. We conclude that E2 is involved in bone matrix formation processes in chick embryos. The lack of medullary bone formation upon E2 treatment in chick embryos is perhaps an indication that, as in growing (immature) birds, it is likely that endogenous testosterone levels in Day 16 chick embryos are insufficient to support medullary bone growth.

Animals↗
PubMed1987

Morphometric quantitation of histopathologic changes in articular cartilage in an immunologically-induced rabbit model of rheumatoid arthritis.

An immune arthropathy was induced in New Zealand white rabbits by intradermal sensitization with complete Freund's adjuvant containing Mycobacterium butyricum followed by intra-articular administration of the bacterial antigen. Half of the animals were treated with 1 mg/kg/day of prednisolone sodium phosphate for 8 weeks by gavage beginning with the day of intra-articular challenge, while the remaining rabbits received the drug vehicle alone. By morphometric analysis (matrix/chondrocyte lacunae area ratio), we observed a significant decrease in cellularity in the arthritic articular cartilages from the vehicle control group. By contrast, there was a significant increase in cellularity in the patella, femoral and tibial cartilages of the steroid-treated animals as compared with that observed in the contralateral control joint. This study suggests that image analysis provides a reliable means for evaluation of architectural changes in the articular cartilage and allows for meaningful quantitation of the chondroprotective effects of drugs like prednisolone.

Animals↗
PubMed1987

Experimental arthropathy induced in rhesus monkeys (Macaca mulatta) by intradermal immunization with native bovine type II collagen.

Over a 6-month time course, polyarticular arthritis was induced in 7 male rhesus monkeys by 3 intradermal injections of bovine type II collagen emulsified in complete Freund's adjuvant, followed later by 2 intradermal injections of type II collagen in incomplete Freund's adjuvant. All animals exhibited delayed-type hypersensitivity to type II collagen by skin test and had serum anti-type II collagen titers of greater than 10,000 (at 1 month) and 20,000 to 160,000 (at 6 months) by enzyme-linked immunosorbent assay. Gross joint changes were observed in 6 of 7 monkeys, especially in the knee and elbow; synovial cell hyperplasia, increased vascularization and a focal mononuclear cell infiltrate were the most frequent findings. Chronic arthritis with destructive cartilage lesions was most prominent in the phalangeal joints of the hands (7 of 7 animals). Microscopically, these changes consisted of fibrosis of the synovium with increased vascularization, villous synovial membrane hyperplasia and focal mononuclear cell infiltration, as well as fibrous metaplasia of the articular cartilage adjacent to pannus formations. Also evident was a loss of safranin O staining intensity in the cartilage and loss of continuity of the articular surface. The 7 control monkeys (received Freund's adjuvant without collagen) were delayed-type hypersensitivity-negative, had no serum anti-type II collagen antibodies, and had grossly and microscopically normal joints. This primate model resembles collagen-induced arthritis seen in rodents and, to some degree, human rheumatoid arthritis.

Animals↗
PubMed1985

Persistence of dead Ostertagia ostertagi in the abomasal mucosa following anthelmintic treatment.

Anthelmintic trails, conducted with albendazole, fenbendazole and ivermectin for efficacy against gastrointestinal nematodes, principally inhibited early fourth larval stages of Ostertagia ostertagi in naturally infected cattle. Cattle wee slaughtered seven to 20 days after treatment. O ostertagi was the predominant abomasal nematode recovered with occasional small numbers of Haemonchus species and Trichostrongylus axei. Control calves uniformly had very large O ostertagi infections, primarily early fourth stage larvae. Viable surviving worms and variable numbers of dead and degenerate worms were recovered in abomasal contents and washings. These O ostertagi larvae and adults were characterised by adherent debris or proteinaceous material, degenerated cuticles and distortion of internal structures. This study demonstrated the necessity for proper timing of slaughter for anthelmintic trial evaluation to allow clearance of dead nematodes, specifically O ostertagi larvae which are sequestered in the abomasal glandular tissue. Nematode collection within seven to 12 days after treatment will include dead and degenerate larval nematodes. The peripheral coating of larvae was suggestive of the Splendore-Hoeppli effect which has been associated with immunological responsiveness. The antigenic stimulus for this material and the lymphocyte and eosinophil infiltration was suspected to be early fourth stage O ostertagi larvae within the mucosa but was not identified definitively.

Abomasum↗
PubMed1984

Transmission and scanning electron microscopy of experimental pulmonary simian varicella (Delta herpesvirus) infection in African green monkeys (Cercopithecus aethiops).

The lungs of African green monkeys infected with simian varicella virus (Delta herpesvirus) were examined by scanning and transmission electron microscopy. Endothelial cell shrinkage, oedema formation and necrosis characterized the scanning electron microscopy of the affected vasculature. Oedema of the interalveolar septa with swelling of the capillary endothelial cells was observed by transmission electron microscopy. Numerous viral particles were associated with a generalized area of necrosis of the alveolar wall.

Animals↗
PubMed1984

Calcium pyrophosphate deposition in nonhuman primates.

Naturally occurring deposition of calcium pyrophosphate has been identified in six rhesus monkeys following acute episodes of trauma and various septicemias. Scanning electron microscopy with energy-dispersive X-ray analytical system and single crystal electron diffraction studies were used to identify the crystals within the articular cartilage. The osteoarthritis grading system was used to determine the degree of cartilage degenerative changes.

Animals↗
PubMed1984

Inflammation induced by subcutaneous turpentine inoculation of young American alligators (Alligator mississippiensis).

Turpentine-induced skin lesions in young American alligators (Alligator mississippiensis) kept at 25 C were used to study inflammatory response in a reptile. Skin harvested at intervals between 4 hours and 30 days after inoculations were done had no gross changes until days 24 to 26, when superficial skin necrosis was evident. Early responses of congestion and dermal edema (4 to 8 hours) were seen by light microscopy, and these were followed by necrosis and granulocyte migration (1 to 3 days). Later, there was predominance of monocytic cells, including vacuolated macrophages (7 to 30 days). Evident at 14 days and prominent by day 30 were central dermal zones of necrotic debris surrounded by orderly palisades of vacuolated multinucleated giant cells and capillary-laden immature fibrous connective tissue. Systemic illness or visceral lesions were not observed. Controls, given inoculations of sterile saline solution, had no gross or microscopic changes.

Alligators and Crocodiles↗