6 research outputs found
Histology of two rice bodies isolated from the stifle of an adult draught horse stallion
In the human and equine species, different kinds of free floating intra-articular particles are related to certain disorders. Osteochondral fragments formed during osteochondrosis dissecans are the most common finding in the equine species, whereas in humans rice bodies due to rheumatoid arthritis are more frequent. Herein we report a third type of floating body inside the stifle of an adult draught horse stallion, in macroscopic appearance similar to articular rice bodies known in humans. As revealed by histologic examination, the two particles consist of polypoid degenerated structures derived from synovial villi. Their formation was probably induced by ischemia
Trypsin-like activity and thromboxane release in adult respiratory distress syndrome.
Plasmatic immunoreactive trypsin (IRT), thromboxane and trypsin-like enzymatic activity were measured in 117 patients at risk of developing adult respiratory distress syndrome (ARDS) (53 multiple injury, 30 abdominal surgery, 17 acute pancreatitis, 12 burnt and 5 disseminated intravascular coagulation patients). 69 of these patients developed ARDS. Immunoreactive trypsin and thromboxane were measured by radio-immuno-assay and trypsin-like enzymatic activity by spectrophotometry, using a specific chromogenic substrate. Mean IRT value was 675 ng/ml in ARDS and 265 ng/ml in non ARDS patients (p less than 0.05). Mean IRT value was 685 ng/ml in septic and 170 ng/ml in non septic patients (p less than 0.01). An abnormal trypsin-like enzymatic activity was measured in 26 ARDS patients. In 60 patients (37 ARDS and 23 non ARDS), thromboxane appeared in plasma simultaneously or about 24 hours after the beginning of IRT release. The importance of thromboxane release parallels the intensity of IRT. Originating from pancreas, trypsin can appear in plasma either by absorption from gastrointestinal tract or after pancreatic ischemia
In Vitro Study of the Antioxidant Properties of Nimesulide and 4-Oh Nimesulide: Effects on Hrp- and Luminol-Dependent Chemiluminescence Produced by Human Chondrocytes
OBJECTIVES: Reactive oxygen species (ROS) are now recognized to play an important role in the pathogenesis of rheumatic diseases and constitute an interesting therapeutic target for drugs. This in vitro study was designed to evaluate the antioxidant properties of nimesulide (NIM), a nonsteroidal antiinflammatory drug of the sulfonanilide class, and its main metabolite 4-OH nimesulide (4-OHNIM). METHODS: The scavenging effects of NIM and 4-OH NIM on hydroxyl radical ((.)OH) and superoxide anions (O(minusd)(2)) were investigated by electron spin resonance (ESR), using 5, 5-dimethylpyrroline-N-oxide (DMPO) as the spin trap agent. The quenching properties of these drugs on hypochlorite anion was studied by luminol enhanced chemiluminescence. Finally, the effects of NIM and 4-OHNIM on the reactive oxygen species production by human articular chondrocytes were recorded by HRP and luminol-enhanced chemiluminescence. RESULTS: By this method it has been demonstrated that NIM and 4-OHNIM, at concentrations ranging from 10 to 100 microM, are potent scavengers of(.)OH whereas only 4-OHNIM was capable to scavenge O(minusd)(2). Chemiluminescence generated by HOCl was also significantly and dose-dependently inhibited by both NIM and 4-OHNIM. Nevertheless, at each concentration tested, the inhibitory effect of 4-OHNIM was significantly more marked, even at the highest concentration (100 microM). Furthermore, when chondrocytes were pre-incubated for 48-96 h with NIM or 4-OHNIM, the luminol- and HRP-dependent CL produced by the cells was significantly inhibited in a dose-dependent manner. CONCLUSIONS: NIM and 4-OHNIM may protect cartilage against oxidative stress, not only by scavenging ROS but also by inhibiting their production by chondrocytes
Assessment of reactive oxygen species production in cultured equine skeletal myoblasts in response to conditions of anoxia followed by reoxygenation with or without exposure to peroxidases.
Objective—To culture equine myoblasts from muscle microbiopsy specimens, examine
myoblast production of reactive oxygen species (ROS) in conditions of anoxia followed by
reoxygenation, and assess the effects of horseradish peroxidase (HRP) and myeloperoxidase
(MPO) on ROS production.
Animals—5 healthy horses (5 to 15 years old).
Procedures—Equine skeletal myoblast cultures were derived from 1 or 2 microbiopsy
specimens obtained from a triceps brachii muscle of each horse. Cultured myoblasts were
exposed to conditions of anoxia followed by reoxygenation or to conditions of normoxia
(control cells). Cell production of ROS in the presence or absence of HRP or MPO was
assessed by use of a gas chromatography method, after which cells were treated with a
3,3′-diaminobenzidine chromogen solution to detect peroxidase binding.
Results—Equine skeletal myoblasts were successfully cultured from microbiopsy specimens.
In response to anoxia and reoxygenation, ROS production of myoblasts increased by
71%, compared with that of control cells. When experiments were performed in the presence of HRP or MPO, ROS production in myoblasts exposed to anoxia and reoxygenation
was increased by 228% and 183%, respectively, compared with findings for control cells.
Chromogen reaction revealed a close adherence of peroxidases to cells, even after several
washes.
Conclusions and Clinical Relevance—Results indicated that equine skeletal myoblast
cultures can be generated from muscle microbiopsy specimens. Anoxia-reoxygenation–
treated myoblasts produced ROS, and production was enhanced in the presence of peroxidases.
This experimental model could be used to study the damaging effect of exercise on
muscles in athletic horses