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Biomedical subjects

C S Carlson

Publications and source records attributed to C S Carlson.

At least 37 records · Page 2Linked to original sources

Examination of bone chemical composition in osteoporosis using fluorescence-assisted synchrotron infrared microspectroscopy.

Although it is clear that osteoporosis is associated with a reduction in bone mass and a fragile skeleton, it is not understood whether the chemical composition of osteoporotic bone is different from normal bone. In this study, cynomolgus monkeys (Macaca fascicularis) were administered fluorochrome labels at one and two years after ovariectomy (Ovx) or Sham ovariectomy (intact), that were taken up into newly remodeled bone. Using fluorescence-assisted synchrotron infrared microspectroscopy, the chemical composition of bone from intact versus Ovx monkeys has been compared. Results from overall composition distributions (labeled + non-labeled bone) reveal similar carbonate/protein and phosphate/protein ratios, but increased acid phosphate content and different collagen structure in the Ovx animals. Analysis of the fluorochrome-labeled bone indicates similar degrees of mineralization in bone remodeled after one year, but decreased mineralization in Ovx bone remodeled two years after surgery. Thus, bone from monkeys with osteoporosis can be characterized as having abnormal collagen structure and reduced rates of mineralization. Coupled with factors such as trabecular architecture and bone shape and size, these ultrastructural factors may play a contributing role in the increased bone fragility in osteoporosis.

Animals↗

Estrogen replacement therapy modulation of the insulin-like growth factor system in monkey knee joints.

OBJECTIVE: Epidemiologic studies have suggested that estrogen replacement therapy may lower the risk of osteoarthritis in women, but the mechanism of this effect is unknown. Since estrogen acts in other tissues in part through regulation of the insulin-like growth factor (IGF) system as well as cytokines including interleukin-6 (IL-6), we determined whether estrogen replacement regulates the levels of these factors in synovial fluid (SF). METHODS: Levels of IGF-1, IGF-2, IGF binding proteins (IGFBP) 1-3, and IL-6 were measured in SF samples obtained from 67 female adult cynomolgus monkeys that had been ovariectomized and treated for 30 months in 1 of 3 groups. Group 1 (n = 24) had no estrogen replacement (control), group 2 (n = 22) received estrogen (Premarin) at the human equivalent of 0.625 mg/day, and group 3 (n = 21) received estrogen at the same dose as group 2, plus progesterone (Provera) at the equivalent of 2.5 mg/day. RESULTS: Compared with controls, estrogen-treated monkeys had 2-fold higher SF levels of IGF-1 (P < 0.001), 1.7-fold higher IGF-2 (P < 0.006), 5.9-fold higher IGFBP-1 (P < 0.02), and 2.5-fold higher IGFBP-3 (P < 0.001). Estrogen plus progesterone-treated monkeys had SF levels of IGF-1, IGF-2, IGFBP-1, and IGFBP-3 that were intermediate between the levels in the control and estrogen groups, except that the level of IGFBP-3 was significantly greater than that in the control group (P < 0.001). SF levels of IGFBP-2 and IL-6 did not differ by treatment group. Treatment group did not affect the serum levels of IGF-1 and IL-6, but IGF-2 and IGFBP-3 were increased by 1.6- and 1.8-fold, respectively, in the estrogen group (P < 0.001). There was no correlation between changes in serum and SF levels of IGF components, except for a weak correlation for IGFBP-3 levels from control (r = 0.464, P = 0.04) and estrogen-treated (r = 0.577, P = 0.008) animals. CONCLUSION: This study demonstrates a significant effect of estrogen replacement on IGF system components in synovial fluid, of which at least some are distinct from any systemic changes observed. The results indicate a potential stimulatory effect of estrogen on joint tissues in vivo.

Animals↗

Localization and expression of cartilage oligomeric matrix protein by human rheumatoid and osteoarthritic synovium and cartilage.

Synovium and cartilage from patients with osteoarthritis or rheumatoid arthritis were analyzed for expression of cartilage oligomeric matrix protein. Immunostaining of synovium with antiserum to cartilage oligomeric matrix protein demonstrated positive staining in both diseases. In osteoarthritis, there was positive staining within the synovial cells and immediately subjacent connective tissue, with less intense staining in the deeper connective tissue. In rheumatoid arthritis, there was less intense staining within the synovial cells and marked intense staining in the deeper connective tissue. In situ hybridization performed with an antisense digoxigenin-labeled riboprobe to human cartilage oligomeric matrix protein confirmed the presence of cartilage oligomeric matrix protein mRNA in the cells of the synovial lining in both types of synovium. Quantitative polymerase chain reaction with a cartilage oligomeric matrix protein MIMIC demonstrated increased cartilage oligomeric matrix protein mRNA in rheumatoid cartilage and synovium as compared with osteoarthritic cartilage and synovium, respectively; mRNA levels in rheumatoid synovium were similar to those from osteoarthritic chondrocytes. As a result of the high expression of cartilage oligomeric matrix protein from rheumatoid synovium, inflammatory synovium should be considered as a potential tissue source of cartilage oligomeric matrix protein in any investigation of biological markers of cartilage metabolism. The upregulated expression of cartilage oligomeric matrix protein in inflammatory tissues suggests its in vivo regulation by cytokines.

Arthritis, Rheumatoid↗

Effect of injected versus iontophoretic corticosteroid on the rabbit tendon.

BACKGROUND: The etiologic role of corticosteroid therapy in tendon rupture is controversial. This study compared the effects of injected versus iontophoretically delivered corticosteroid on the normal rabbit Achilles tendon. METHODS: Rabbits were divided into three treatment groups: (1) corticosteroid injections, (2) iontophoretically delivered corticosteroid, and (3) no treatment. One tendon of each rabbit in the treatment groups was treated with either drug injection or iontophoresis; the tendon of the other leg served as a control. Some tendons were used for testing elastic modulus, ultimate load, and ultimate stress, while the remaining tendons were evaluated histologically. RESULTS: Injections of either corticosteroid or saline into the tendon sheath resulted in short-term changes in tendon biomechanical characteristics and somewhat higher histologic severity scores; however, iontophoretic delivery of corticosteroid or saline did not affect either significantly. CONCLUSIONS: Iontophoresis using sterile water or corticosteroid resulted in minimal or no biochemical and histologic changes in the tendon compared with injection of either substance. The method of corticosteroid delivery may be as important as the actual drug effects on the biomechanical and histologic properties of tendons.

Achilles Tendon↗

Up-regulation of inducible nitric oxide synthase and production of nitric oxide by the Swarm rat and human chondrosarcoma.

Production of nitric oxide by solid tumors may have important ramifications regarding tumor growth and potential metastasis. This study demonstrated that the chondrosarcoma of the Swarm rat has upregulated mRNA for inducible nitric oxide synthase and produces nitric oxide. These results were confirmed by (a) the presence of a 4.4-kb band of mRNA detected by Northern blot using a probe for inducible nitric oxide synthase, (b) a 133-kDa band of protein that was detected with either a polyclonal or monoclonal antibody to the inducible nitric oxide synthase of the murine macrophage, and (c) the detection of nitrites from the culture medium of freshly cultured, isolated chondrosarcoma cells. This study showed that the expression of inducible nitric oxide synthase and the production of nitric oxide by the tumor can be increased by stimulation with endotoxin lipopolysaccharide and can be inhibited by inducible nitric oxide synthase inhibitors (L-N(g)-monomethyl arginine and aminoguanidine). Immunostaining confirmed the presence of inducible nitric oxide synthase within the tumor cells and appeared to localize the enzyme to the cytoplasm of the cells. A human chondrosarcoma was also shown to have an upregulated inducible nitric oxide synthase by both the detection of mRNA for inducible nitric oxide synthase and the presence of nitrites from the culture medium of the tumor in organ culture. Because the chondrosarcoma of the Swarm rat is a well differentiated solid tumor that rarely metastasizes, nitric oxide may be produced by the tumor to promote local growth by effects on vascular supply.

Animals↗

The pathophysiology of osteochondrosis.

Osteochondrosis is a disorder of epiphyseal cartilage about which there is considerable confusion in the literature. We believe that this is due to the fact that osteochondrosis has been studied in the chronic stage when the lesions are morphologically complicated and the initial causative insult is impossible to determine. The etiology of osteochondrosis appears to be multifactorial, with trauma, hereditary factors and rapid growth, nutritional factors, and ischemia all having a role in its pathogenesis. Although predilection sites are variable among species, the morphology of the early lesions is strikingly similar, strongly suggesting that the pathogenesis of osteochondrosis is the same, regardless of the species affected. Based on recent studies in pigs and horses, and supported by observations in dogs and cattle, we believe that local ischemia secondary to defects in cartilage canal blood supply is a key factor in the initiation of lesions of osteochondrosis and explains many of the features of this disease. Local ischemia to the epiphyseal cartilage of the articular-epiphyseal cartilage complex leads to the formation of highly vulnerable zones of necrotic epiphyseal cartilage which later cause a delay in endochondral ossification, with extension of necrotic cartilage into the subchondral bone. Trauma, whether major or minor, to the overlying articular cartilage leads to cartilage cleft formation, clinical signs of pain and lameness, and other chronic sequelae. Studies aimed at further elucidating the pathogenesis of osteochondrosis should attempt to determine the cause of the vascular defect and whether or not it may be modified by experimental manipulations.

Animals↗

Effects on bone of oral hormone replacement therapy initiated 2 years after ovariectomy in young adult monkeys.

The purpose of this study was to determine the effects of oral estrogen replacement therapy with conjugated equine estrogens (CEE), alone or in combination with continuous medroxyprogesterone acetate (MPA), on lumbar spine bone mineral content (BMC) and density (BMD) and on serum chemistries in ovariectomized cynomolgus monkeys when therapy is initiated following a 2 year hypoestrogenic period. Study design was done in the form of a randomized, placebo-controlled, nonhuman primate paraclinical trial. Monkeys were subjects in an experiment designed to study the effects of a lipid-lowering diet combined with hormone replacement therapy on atherosclerosis. Initially, they were ovariectomized and fed a high-fat diet for 24 months. They were then were allocated to three treatment groups by stratified randomization and were fed a diet containing reduced dietary fat for an additional 28 months. Treatment groups consisted of: (1) an untreated group (ovx, n = 24); (2) a CEE-treated group (CEE, n = 19); and (3) a CEE plus continuous MPA group (CEE + MPA, n = 20). Lumbar spine BMC and BMD values were measured by dual-energy x-ray absorptiometry at baseline and 4, 10, 16, 22, and 28 months of treatment. Serum chemistries were relevant to bone metabolism at 22 and 28 months. Rates of gain in BMC and BMD were greater (p < 0.05) in hormone-supplemented animals (groups 2 and 3) than in untreated ovx animals during the first 16 months of treatment, resulting in increased BMC and BMD measurements in these groups. Serum markers of bone metabolism were significantly lower (p < 0.05) in the hormone-treated groups (groups 2 and 3) compared with ovx animals after 22 and 28 months of treatment, indicating reductions in bone turnover rate. Oral estrogen replacement with CEE at doses similar to those taken by women leads to significantly increased BMC and BMD in monkeys, even when therapy is begun 2 years after ovariectomy. Most of the increase occurred during the first 16 months of treatment. The addition of MPA to the CEE regimen provided no additional benefit.

Absorptiometry, Photon↗

Changes in bone mass and bone biomarkers of cynomolgus monkeys during pregnancy and lactation.

A substantial amount of calcium is transferred from the mother to the fetus and infant during pregnancy and lactation. Involvement of the skeleton in meeting this demand should be reflected in changes in bone mass and turnover. The purpose of the study was to determine the effects of pregnancy, lactation, and recovery on the skeleton in 43 young (prepeak bone mass) female monkeys. Whole body (WBBMC) and lumbar vertebrae 2-4 bone mineral content were determined by dual x-ray absorptiometry at baseline and 1, 4, and 10 months postpartum. Alkaline phosphatase, bone Gla protein, and urinary crosslinks were measured at baseline, during the third trimester, and 1, 4, and 10 months postpartum. Compared to nonpregnant, nonlactating monkeys, pregnant monkeys had similar rates of bone mass gain (nonpregnant, nonlactating WBBMC, 25+/-9 mg/day; pregnant WBBMC, 20+/-14 mg/day). Compared to pregnant monkeys, lactating females had increased bone turnover, as indicated by elevated bone biomarker levels (lactating alkaline phosphatase, 259+/-20 IU/L) and decreased bone mass (lactating WBBMC, -99+/-21 mg/day). Densitometry showed that bone mass gain in the lactating monkeys did not compensate for lactational loss by 10 months postpartum (WBBMC, 6.95+/-9 mg/day). This lack of recovery may have been due to the fact that serum estrogen concentrations were just beginning to return to baseline at 10 months postpartum. In conclusion, the cynomolgus monkey skeleton responds similarly to that of women during pregnancy and lactation. Recovery from lactational bone loss is not complete by 10 months postpartum.

Absorptiometry, Photon↗

A method for examining the chemical basis for bone disease: synchrotron infrared microspectroscopy.

Infrared microspectroscopy combines microscopy and spectroscopy for the purpose of chemical microanalysis. Light microscopy provides a way to generate and record magnified images and visibly resolve microstructural detail. Infrared spectroscopy provides a means for analyzing the chemical makeup of materials. Combining light microscopy and infrared spectroscopy permits the correlation of microstructure with chemical composition. Inherently, the long wavelengths of infrared radiation limit the spatial resolution of the technique. However, synchrotron infrared radiation significantly improves both the spectral and spatial resolution of an infrared microspectrometer, such that data can be obtained with high signal-to-noise at the diffraction limit, which is 3-5 microm in the mid-infrared region. In this study, we use infrared microspectroscopy to study the chemical composition of bone using two mapping methods. In the osteon method, linear maps are collected from the center of an osteon (newer bone) to the periphery (older bone) and their chemical compositions are compared. In the transverse method, applied specifically to subchondral bone, line maps are collected from the edge of the articular cartilage (older bone) to the marrow space (newer bone). A significant advantage of infrared microspectroscopy over other chemical methods is that the bone does not need to be homogenized for testing; we are able to study cross-sectional samples of bone in situ at a resolution better than 5 microm and compare the results with morphological findings on stained serial sections immediately adjacent to those examined by infrared microspectroscopy. The infrared absorption bands of bone proteins and mineral are sensitive to mineral content (i.e. carbonate, phosphate, acid phosphate), mineral crystallinity and the content/nature of the organic matrix. In this study, they are analyzed as a function of (1) age, i.e. distance with respect to the center of an osteon, and (2) morphology, i.e. cortical versus cancellous (notably subchondral) bone. Results show that the protein/mineral ratio is higher in younger bone. As bone matures, mineralization increases, as does carbonate substitution into the hydroxyapatite lattice. Finally, most of the changes in chemical composition of bone occur within 20 microm of the site of new bone growth, e.g. the center of an osteon, demonstrating the need for the high spatial resolution achieved only with the use of a synchrotron infrared source.

Animals↗

Expression of cartilage oligomeric matrix protein by human synovium.

Human synovium was analyzed for the possible expression of cartilage oligomeric matrix protein (COMP). Immunostaining with polyclonal antiserum to COMP demonstrated positive staining within the synovial cells and immediately subjacent connective tissue, with less intense staining in the deeper connective tissue. Western blot analysis using either polyclonal or monoclonal antibodies to human COMP confirmed the presence of COMP by immunoreactive bands with the same molecular mass (approximately 110 kDa) as purified articular cartilage COMP. PCR using oligonucleotides that span human COMP exons 7-13 revealed identical amplification products from cDNA prepared from either human chondrocytes or synovium. Northern blot analysis using a biotinylated-probe to human COMP, spanning exons 12-13, also reveal an identical hybridization product to either human chondrocyte or synovium total RNA. Human synovium should be considered as a potential tissue source of COMP in any investigation of biological markers of cartilage metabolism.

Base Sequence↗

Human chondrocyte expression of growth-arrest-specific gene 6 and the tyrosine kinase receptor axl: potential role in autocrine signaling in cartilage.

OBJECTIVE: To determine if human articular chondrocytes express the axl tyrosine kinase receptor and its ligand Gas-6, a protein product of growth-arrest-specific gene 6, and to determine if Gas-6 and axl function in the regulation of chondrocyte growth and survival. METHODS: The presence of Gas-6 and axl was examined in situ in human articular cartilage by immunohistochemistry and in vitro in cell culture studies using primary human chondrocytes and immortalized human chondrocytes. The ability of recombinant Gas-6 to mediate adhesion of chondrocytes and to stimulate chondrocyte axl phosphorylation was determined. Studies of the role of Gas-6 and axl in cell proliferation and survival were also performed. RESULTS: Both Gas-6 and axl were detected in cartilage by immunohistochemical staining. Gas-6 and axl messenger RNA (mRNA) and protein were also detected in cultures of primary and immortalized human chondrocytes. Compared with cells cultured in medium containing 10% serum, Gas-6 mRNA levels were increased in immortalized chondrocytes cultured in serum-free medium, while axl expression decreased. Chondrocytes attached to Gas-6-coated plastic, and the attachment was blocked by a soluble Ig fusion protein containing the axl extracellular domain. Recombinant human Gas-6 and serum-free conditioned medium from primary and immortalized human chondrocyte cultures stimulated chondrocyte axl tyrosine phosphorylation. A mitogenic effect was noted both when immortalized chondrocytes were stimulated with recombinant Gas-6 or when they were made to overexpress axl by transfection. Addition of recombinant Gas-6 to serum-free medium resulted in increased survival of primary chondrocytes cultured at low density in agarose. CONCLUSION: These findings present evidence for an autocrine signaling pathway in cartilage involving Gas-6 and the axl tyrosine kinase adhesion receptor. Stimulation of axl by Gas-6 may play an important role in the control of chondrocyte growth and survival.

3T3 Cells↗

The androgenic anabolic steroid nandrolone decanoate prevents osteopenia and inhibits bone turnover in ovariectomized cynomolgus monkeys.

We examined the effects of nandrolone decanoate (25 mg im every 3 weeks) on bone mass, serum biomarkers, and bone histomorphometric endpoints in 52 female cynomolgus macaques randomized into four treatment groups: (1) sham-ovariectomized (sham); (2) ovariectomized + placebo for 2 years (ovx); (3) ovx + nandrolone decanoate for 2 years (Nan); and (4) ovx + nandrolone decanoate beginning 1 year after ovx (dNan). Serum alkaline phosphatase (ALP), osteocalcin, and tartrate-resistant acid phosphatase (TRAP) were assayed every 3 months, and X-ray densitometry of the lumbar spine was done every 6 months. Fluorochrome-labeled iliac biopsies collected at baseline and 1 year, and lumbar vertebrae and midshaft femur collected at 2 years, were evaluated histomorphometrically. Body weight increased over 50% with administration of nandrolone. After 2 years, ovx animals had lower spinal BMC and BMD than all other groups. Ovx animals also had higher bone turnover rates than all other groups, as indicated by higher levels of the serum and urine biomarkers, and by at least twofold higher label-based bone formation rates in the femur diaphysis and in both cancellous and cortical bone of the ilium and vertebral bodies. Nandrolone-treated animals had similar serum estradiol levels as the sham animals, presumably due to conversion of endogenous or exogenous androgens. The effects of nandrolone on bone in this experiment are consistent with estradiol action and may be attributable to the increased serum estradiol. Despite >50% higher body weight, nandrolone-treated, ovariectomized animals did not have higher bone mass than sham animals.

Absorptiometry, Photon↗

Fatal disseminated cercopithecine herpesvirus 1 (herpes B infection in cynomolgus monkeys (Macaca fascicularis).

Two adult female cynomolgus monkeys (Macaca fascicularis) that had been housed together for 4 months died within 2 weeks of each other after brief illnesses. Monkey No. 1 presented with collapse, watery stool, and hypothermia and died overnight. Monkey No. 2 presented with dyspnea, nasal discharge, leukopenia, and hypoproteinemia and was euthanized after 2 days. Both animals had peritoneal effusions, massive necrosis of pharyngeal, esophageal, and gastric mucosa, and multifocal hepatic and pancreatic necrosis. Monkey No. 2 also had lingual ulcers and locally extensive necrosis of spleen, adrenal glands, and lymph nodes. Large numbers of eosinophilic intranuclear inclusion bodies were present in epithelial and syncytial cells adjoining the necrotic foci in Monkey No. 2 but were absent in Monkey No. 1. Monkey No. 1 seroconverted to cercopithecine herpesvirus 1 (CHV-1, commonly known as herpes B) in the month before death. CHV-1 was isolated from a sample of stomach from Monkey No. 2, and electron microscopy of liver from this animal demonstrated herpesvirus particles within hepatocytes. Both animals were seropositive for simian type D retrovirus, and the virus was cultured from the liver of Monkey No. 2. A diagnosis of disseminated CHV-1 infection was made, possibly occurring secondary to immunosuppression due to infection with simian type D retrovirus. Although a high percentage of cynomolgus monkeys are apparently infected with CHV-1, disseminated disease is rare. Because infection with CHV-1 in humans is associated with a high fatality rate, familiarity with the lesions of disseminated infection with this virus is important.

Adrenal Glands↗

Osteoarthritis in cynomolgus macaques. III: Effects of age, gender, and subchondral bone thickness on the severity of disease.

Knee joints from cynomolgus monkeys of both genders and a wide range of ages were examined to characterize further the natural history of osteoarthritis (OA) in these animals. The objectives of this study were to characterize better the subchondral bone changes previously noted in this disease, to determine whether the severity of OA in these animals is affected by age or weight, and to determine whether males and females are affected similarly. As had been seen in previous studies, the medial tibial plateau was the most severely affected site. The thickness of the subchondral plate in the medial tibial plateau increased with increasing severity of articular cartilage lesions in both males and females; however, in monkeys with subchondral plate thicknesses less than 400 microns, articular cartilage lesions were essentially absent. Subchondral plate thickness increased with increasing weight in both genders, but females had a higher subchondral plate thickness than males for a given body weight. There was no correlation between bone volume in the proximal tibial epiphysis and articular cartilage lesions of OA. The prevalence and severity of OA in the medial tibial plateau increased with increasing age, but were not affected by gender or weight. Although there was no correlation between articular cartilage lesions and body mass index or weight, the waist/hip circumference ratio and severity of articular cartilage lesions were correlated in the female monkeys. This work provides evidence that thickening of the subchondral bone plate may be more important than the volume of epiphyseal/metaphyseal cancellous bone in determining the biomechanical stresses in the joint and in influencing the development of articular cartilage lesions.

Aging↗

Increased degradation and altered tissue distribution of cartilage oligomeric matrix protein in human rheumatoid and osteoarthritic cartilage.

We investigated the degradation and tissue distribution of cartilage oligomeric matrix protein in normal, osteoarthritic, and rheumatoid arthritic articular cartilage of the human knee. Cartilage was subjected to sequential extractions with buffers containing neutral salt, with EDTA, and finally with guanidine/HCl and then was analyzed by Western blotting with a polyclonal antiserum to human cartilage oligomeric matrix protein. Western blots of the nine neutral salt extracts from normal cartilage revealed mostly intact pentameric molecules of cartilage oligomeric matrix protein, in contrast to the 13 osteoarthritic and five rheumatoid arthritic cartilage samples that demonstrated marked degradation of cartilage oligomeric matrix protein as noted by a predominance of reduction-sensitive bands at approximately 150 kDa and nonreduction-sensitive bands in the 67-94 kDa range. The EDTA and guanidine/HCl extracts from all groups were similar and showed mostly intact molecules of cartilage oligomeric matrix protein, with smaller amounts of degraded cartilage oligomeric matrix protein identical to those resolved by the Western blots of the neutral salt extracts. Western blots of matched pairs of synovial fluid and cartilage extracts demonstrated cartilage oligomeric matrix protein fragments of the same molecular mass. Competitive enzyme-linked immunosorbent assay revealed significantly less cartilage oligomeric matrix protein in rheumatoid articular cartilage than in either normal or osteoarthritic cartilage. In contrast to normal cartilage, where cartilage oligomeric matrix protein was predominantly localized to the interterritorial matrix throughout all zones of the matrix, with increased staining in the deeper cartilaginous zones, the most intense staining in osteoarthritic cartilage was in the superficial zones of fibrillated cartilage, with little to no immunostaining in the midzones and relatively poor staining in the deeper cartilaginous zones. This distribution was the inverse of that for proteoglycans, as demonstrated by toluidine blue staining, where proteoglycans were depleted primarily from the superficial fibrillated cartilage. In mild to moderately affected rheumatoid cartilage, the tissue distribution of cartilage oligomeric matrix protein was similar to the distribution of proteoglycans, with relatively uniform staining of the interterritorial and territorial matrics. In more severely affected rheumatoid cartilage, the superficial zones demonstrated punctate immunostaining for cartilage oligomeric matrix protein in the interterritorial and territorial matrics, and staining was restricted to the territorial matrix in the deep cartilaginous zones. It is evident from this study that (a) noncollagenous proteins such as cartilage oligomeric matrix protein are greatly affected in arthritis, (b) degradation fragments released from the matrix into the synovial fluid reflect the processes occurring within the matrix, and (c) different zones of the articular cartilage are susceptible to degradation of cartilage oligomeric matrix protein in the different disease processes.

Adult↗

Gastric infarction in cynomolgus monkeys (Macaca fascicularis).

Five cases of gastric infarction were observed in adolescent or adult cynomolgus monkeys (Macaca fascicularis) over a 20-month period. Gastric infarcts were encountered as striking and unexpected findings at necropsy. Gross and microscopic findings included gastric necrosis, hemorrhage, and edema that involved large areas of the fundus and pylorus. A consistent finding was the presence of thrombi in the gastric microvasculature, particularly in the venous system. All animals had acute clinical episodes with substantial tissue damage resulting from a variety of causes, including trauma, pancreatitis, necrotizing cystitis, and intestinal intussusception. In addition, three animals had microvascular thrombosis in nongastric tissues. Our findings suggest that cynomolgus monkeys may be predisposed to developing gastric infarction under conditions of severe systemic insult that predispose to disseminated intravascular coagulation.

Animals↗

Cerebral infarction in two cynomolgus macaques (Macaca fascicularis) with hypernatremia.

Hypernatremia resulting in neurologic symptoms ranging from lethargy to coma, and with underlying lesions of cerebral hemorrhage and thrombosis, has been reported in human beings. Herein we report two cases of cerebral infarction with venous thrombosis in cynomolgus monkeys. Both animals were severely hypernatremic because of water deprivation, with serum sodium levels of 185 and 193 meq/liter, respectively. At necropsy, there were bilateral multiple hemorrhagic and malacic areas visible on the surface of the cerebrum and extending into the parenchyma, primarily involving the occipital lobes. These lesions were interpreted microscopically as infarcts because, in addition to hemorrhage and necrosis, multiple thrombi were present in small and medium-sized veins of gray matter and meninges. The pathogenesis of hypernatremia-induced cerebral lesions is believed to involve cellular dehydration that caused shrinkage of the brain. Because the vasculature of the brain is tightly adherent to the skull, this shrinkage results in tearing of blood vessels, with consequent hemorrhage and thrombosis.

Animals↗

Islet amyloid and islet amyloid polypeptide in cynomolgus macaques (Macaca fascicularis): an animal model of human non-insulin-dependent diabetes mellitus.

To further characterize spontaneous diabetes mellitus in cynomolgus macaques (Macaca fascicularis) as a model for human non-insulin-dependent diabetes mellitus (NIDDM), we evaluated the morphologic characteristics of the endocrine pancreas of 4 diabetic and 12 age-matched nondiabetic cynomolgus macaques. In addition, the cDNA-predicted amino acid sequence for islet amyloid polypeptide (IAPP) of this species was determined. Islet amyloid deposits exhibiting typical congophilia and green birefringence were found in 4/4 diabetic animals and in 8/12 nondiabetics. Islet amyloid deposits were significantly more extensive in the diabetic macaques (P = 0.001), in which they occupied a mean of 60% of the islet area. In contrast, in the nondiabetic group the maximum islet area occupied by amyloid was 24% (group mean = 6.8%), with four animals having no detectable islet amyloid. Amyloid deposits consistently showed immunoreactivity for IAPP but not for insulin. Comparisons between group means for diabetic versus nondiabetic macaques showed significantly greater islet area (P = 0.01, 85,390 versus 36,540 microns 2) and significantly greater islet area fraction (P = 0.02, 0.065 versus 0.032) for the diabetic group. The cDNA-predicted amino acid sequence for cynomolgus IAPP was identical to that previously reported for pig-tail macaques (M. nemestrina) and had 92%, 86%, and 84% amino acid sequence identity with human, domestic cat, and murine IAPPs, respectively. These findings support the use of cynomolgus macaques as an animal model of human NIDDM.

Amino Acid Sequence↗