OBJECTIVETo investigate the efficacy of S-methylisothiourea (SMT) for treatment of temporomandibular joint osteoarthrosis (TMJOA) of goats.

METHODSNine purebred black goats were randomly devided into three groups: Normal control group, control group and experimental group. The upper compartments of both temporomandibular joint of the goats in control group and experimental group were injected with collagenase only once to induce osteoarthrosis. Normal control group received no treatment. The upper compartments of both TMJ were injected with 0.5 mL of normal saline, and experimental group, the upper compartments of both TMJ were injected with 0.5 mL of SMT. The TMJ of goats was examined with scanning electron microscopy and microscopy after sacrificed.

RESULTSExamined in light microscopy and scanning electron microscopy, normal control group showed normal performance, the control group showed severe osteoarthrotic changes in the temporal surface, disk and condyle, while the experimental group showed improvement of different degree.

CONCLUSIONOn the basis of 3-month following-up study, repeated intra-articular injection of SMT may play a role in inhibiting TMJOA progression.

Animals ; Injections, Intra-Articular ; Isothiuronium ; analogs & derivatives ; Osteoarthritis ; Temporomandibular Joint ; Temporomandibular Joint Disc ; Temporomandibular Joint Disorders

OBJECTIVETo investigate the influence of induced nitric oxide synthase (iNOS) expression on apoptosis of thymocyte in burn rats, and to explore the relationship between NO and pathological lesion of the thymus gland in burn rats.

METHODSFifty-six male Wistar rats were enrolled in the study and randomized into control( C, n = 8,without treatment) , burn ( B, n = 24) , and S-methylisothiourea( SMT, n = 24) groups. Equal amount of isotonic saline solution and SMT(7. 5 mg/kg) were respectively intravenously infused into the rats in B and SMT groups after being inflicted with 30% TBSA full-thickness burns. The weight of thymus gland in each group were weighed, and thymocyte apoptosis and iNOS expression were determined with TUNEL method and immunohistochemistry, respectively at 6,24,72 postburn hours( PBH) , with 8 rats at each time-point. The number of apoptotic cells and the density of iNOS positive cells in thymus was measured by stereological method.

RESULTSThe weight of thymus in B group at 24 and 72 PBH [ (153+/- 14) , (91+/-22) mg] were obviously heavier than those in C group, but much lighter than those in SMT group ( P < 0.01). A few apoptotic cells and iNOS positive cells were observed in cortex and medulla of thymus in C group, while they were observed in B group at 6 PBH, and the number of cells began to increase at 24 PBH, distributing in medulla,parenchyma, the boundary of cortex, and medulla under capsule. The iNOS positive cells in B group at 24 PBH were distributed around the interlobular septum. A large number of cortical cells with brown staining were observed in B group at 72 PBH, and the number of iNOS positive cells also increased, with scattered distribution and clear cell boundary. Fewer positive cells with uneven distribution, no iNOS positive cells, and few apoptotic foci were observed in SMT group after burns. The density of apoptotic cells in B group at 24 and 72 PBH was (2. 428 +/-0. 728) x 10(-5)/microm(3) and (5. 586 +/- 1.233) x 10(-5)/microm(3), respectively, which was obviously higher than that in C and SMT group. The density of iNOS positive cells in B group was increased in a time-dependent manner( P <0. 05).

CONCLUSIONThe apoptotic rate of thymocyte in severely burn rats increases early after burns. The up-regulation of iNOS expression in thymus can promote apoptosis of thymocytes, while SMT can partially ameliorate this phenomenon.

Animals ; Apoptosis ; Burns ; metabolism ; pathology ; Gene Expression Regulation ; Isothiuronium ; analogs & derivatives ; pharmacology ; Male ; Nitric Oxide Synthase Type II ; metabolism ; Organ Size ; Rats ; Rats, Wistar ; Thymus Gland ; cytology ; metabolism

OBJECTIVETo study the effect of nitric oxide synthase inhibitor, S-methyl thiocarbamate (SMT), on proteoglycan metabolism in repaired articular cartilage in rabbits.

METHODSTwenty-four male New Zealand white rabbits, aged 8 months and weighing 2.5 kg+/-0.2 kg, were used in this study. Cartilage defects in full thickness were created on the intercondylar articular surface of bilateral femurs of all the rabbits. Then the rabbits were randomly divided into 3 groups (n=8 in each group). The defects in one group were filled with fibrin glue impregnated with recombinant human bone morphogenetic protein-2 (rhBMP-2, BMP group), in one group with fibrin glue impregnated with rhBMP-2 and hypodermic injection with SMT (SMT group) and in the other group with nothing (control group). All the animals were killed at one year postoperatively. The tissue sections were stained with safranine O-fast green and analyzed by Quantiment 500 system to determine the content of glycosaminoglycan through measuring the percentage of safranine O-stained area, the thickness of cartilages and the mean gray scale (average stain intensity). Radiolabelled sodium sulphate (Na(2)(35)SO(4)) was used to assess the proteoglycan synthesis.

RESULTSAt one year postoperatively, the percentage of safranine O-stained area, the mean gray scale and the cartilage thickness of the repaired tissues in SMT group were significantly higher than those of BMP group (P<0.01) and the control group (P<0.05). Result of incorporation of Na(2)(35)SO(4) showed that the proteoglycan synthesis in SMT group was higher than those of BMP group and the control group (P<0.01).

CONCLUSIONSSMT, a nitric oxide synthase inhibitor, can significantly increase the content of glycosaminoglycan and proteoglycan synthesis, and computer-based image analysis is a reliable method for evaluating proteoglycan metabolism.

Analysis of Variance ; Animals ; Biopsy, Needle ; Cartilage Diseases ; drug therapy ; pathology ; Cartilage, Articular ; drug effects ; pathology ; Disease Models, Animal ; Immunohistochemistry ; Isothiuronium ; analogs & derivatives ; pharmacology ; Male ; Nitric Oxide Synthase ; antagonists & inhibitors ; pharmacology ; Probability ; Proteoglycans ; drug effects ; metabolism ; Rabbits ; Random Allocation ; Reference Values ; Sensitivity and Specificity