Leporine Experimental Arthritis Induced by Whole Synovial Fluid from Patients with Rheumatoid Arthritis and Osteoarthritis

The value of experimental arthritis models in animals depends on their morphological and immunological  similarities to rheumatoid arthritis even if they are not exact counterparts of the human diseases. Many  uncertainties regarding rheumatoid arthritis pathogenetic mechanisms persist, including unknown factors  and the liberation of arthritogenic antigens. The purpose of the study was to compare experimental arthritis  in rabbits induced by intra-articular injections of whole synovial fluid obtained from patients with active  rheumatoid arthritis and osteoarthritis, which followed sensitization with synovial fluid in complete  Freund’s adjuvant. The results showed that rheumatoid synovial fluid-induced arthritis is very reproducible  and strikingly similar to the rheumatoid arthritis where the arthritis exacerbations and immunological  processes occur all the way from cellular immunity to persistent chronic arthritis.

Effects of Antirheumatic Drugs on the Development of Experimental AA Amyloidosis in C57BL/6 Mice

Because there is no known specific effective therapy for secondary amyloidosis at the present time, the aim  of this study was to determine whether antirheumatic drugs inhibit the development of experimental AA  amyloidosis, induced in a C57BL/6 mice by injections of casein and fibrin. Monotherapy with sulfasalazine  (SSL) and diclofenac (D) and combined treatment with diclofenac and prednisolone (D/P) by using  prophylactic and therapeutic treatment protocols were investigated. The drugs were administered through  intragastric gavage 5 times a week for 5 or 6 weeks in the following doses: D - 1 mg/kg, P - 10 mg/kg,  and SSL - 100 mg/kg. Histopathological examination of splenic, kidney and hepatic tissues of mice was  performed. The amount of amyloid was assessed semi-quantitatively by polarizing microscopy after Congo Red staining. Our study indicated that no positive effect from prophylactic treatment with D could be seen on amyloid  deposition in investigated organs. Prophylactic combined treatment with D/P resulted in significant improvement  of disease symptoms and markedly reduced amyloid deposits in the spleen, kidneys, and liver (P  < 0.02-0.001). SSL therapy alone has been more successful in the prophylactic treatment of experimental  amyloidosis: the decrease of amyloid deposits was statistically significant in all investigated organs (P <  0.04 – 0.001) and the most suppression of amyloid formation in the kidneys and liver was observed (P <  0.004-0.001). In therapeutic treatment of experimental amyloidosis, combined treatment with D/P showed  the most inhibition of amyloid formation in the internal organs (P < 0.006 – 0.001). The highest suppression  (by 86.7%; P < 0.001) of amyloid deposits was observed in the liver. Treatment of mice with D alone  produced a significant reduction in amyloid deposition only in the liver (P < 0.03) and with SSL – only in  the spleen (P < 0.03). These findings suggest that D/P and SSL at relevant doses suppress amyloidogenesis and this suppression is  possibly related to the anti-inflammatory effect of antirheumatic drugs. Although these drugs cannot completely  inhibit the disease in this model, a possibility remains that they may be clinically useful in rheumatic  diseases associated with the formation of amyloidogenic derivatives.

Influence of Dextran Sulphate, Fibrin, and Ubiquitin on the Development of Casein-Induced Experimental AA Amyloidosis in C57BL/6 mice

The influence of subcutaneous injections of dextran sulphate (DS) and fibrin (F), as well as of an intraperitoneal  injection of ubiquitin (Ub), was investigated on 48 male C57BL/6 mice subjected to conventional  casein (C) induced amyloidosis. Histopathological examination of spleen and kidney tissue 3 and 5 weeks  after termination of the amyloidogenic stimulus showed that the amount of amyloid deposited (rated trace,  minimal, moderate or heavy) increased progressively with the duration of the amyloidogenic stimulus.  After 3 weeks of stimulation, 16.7% of mice injected with C had some perifollicular amyloid deposits in  the spleen while all had traces of amyloid in the kidney. Some amyloid was detected in the spleen of 33.3%  of the mice treated with C+DS and C+Ub and 83.3% treated with C+F. Half the latter group also showed  traces and half minimal amyloid deposits in their kidneys. In the other test groups, the incidence of kidney  amyloidosis was less. The most extensive tissue deposits were seen at 5 weeks postinjection (p.i.) with most in the C+F-treated  animals, all showing significantly more than the control C-treated group. Thus half the C+F-treated animals  had moderate and half heavy deposits throughout their spleens. Glomerulonephritis, kidney tubular  edema and some amyloid deposits were present in all of the animals. C+Ub resulted in a similar incidence  of amyloid accumulation in the spleen but in the kidneys 66.7% of animals had only traces of amyloid and  33.3%, minimal amyloid deposits. Amyloid was deposited in the mouse kidneys predominantly in the arterial  walls but also occurred in the basement membrane and interstitial tissues. A post-mortem examination  of the internal organs revealed splenomegaly in all the test groups and increased liver weight in the C-,  C+F-, and C+Ub-treated groups. The leukocyte count and ESR (erythrocyte sedimentation rate) were also  higher in all the experimental groups. Thus, the results indicated that F and Ub play a role in the amyloid deposition process in the experimentally  induced disorder in C57BL/6 mice and could enhance this pathological process.

Investigation on particulate matter and gas motion processes in the advanced multi-channel cyclone-separator with secondary gas inlets

Research into gas flow motion as a transported phase and pollutant - particulate matter (PM) is of crucial importance, their changes in particular areas of the object require knowledge of improving the apparatus. A cyclone is considered one of the most popular devices due to the new modified multi-channel design that involves combined separation and filtration phenomena. The findings of an accurate numerical model provide an opportunity to verify long-term experimental studies. In addition, it is possible to determine the impact of the designed principal elements of the structure comprising secondary gas inlets, inner slits and the convex bottom on gas and PM motion through verification conducting experimental research. The study focuses on simulating the upgraded cyclone using the SST k-omega model. The research has been conducted under the specified gas flow conditions such as high temperature and relative humidity (aggressive) gas and presents the results of the physical model to compare with. To achieve greater computational accuracy, a digital model of the cyclone made of specific volumetric elements has been developed thus expanding the grid and stepping to form the boundary zone. As a result, numerical simulation results differ by no more than 12.8% compared to the experimental studies results