Mechanical Properties of Bone in a Paraplegic Rat Model

Abstract

Pathologic fractures may occur with minimal trauma after spinal cord injury (SCI) because of osteoporosis. Rats were evaluated to determine whether they could be used as an SCI animal model. Male Sprague-Dawley rats underwent spinal cord transection at the ninth thoracic vertebrae. Control rats underwent a sham procedure. Mechanical testing of the humeral shaft, femoral shaft, tibial shaft, femoral neck, distal femur, and proximal tibia was performed separately at 0, 8, and 24 weeks after surgery. At 24 weeks, significant differences between SCI and control rats were found in maximum torque needed to produce failure in the femoral shaft (63 percent of control, p < 0.05) and tibial shaft (63 percent, p < 0.01), and in compressive load to produce failure in cross-sectional specimens of the distal femur (51 percent, p < 0.05) and proximal tibia (50 percent, p < 0.01 ). No differences were found in the maximum torque needed to produce failure of the humeral shaft (106 percent, p = 0.77) between SCI and control rats. Reductions in relative bone strength in SCI rats at 24 weeks were similar in magnitude to bone mineral density changes reported in humans with chronic paraplegia. Thus, Sprague-Dawley rats appear to be good animal models in which to evaluate changes in bone strength following SCI. U Spinal Cord Med 1998; 21:302-308)     

Interleukin-6 gene promoter methylation in rheumatoid arthritis and chronic periodontitis

Background: Methylation status of the cytokine genes may play a role in the pathogenesis of inflammatory diseases, such as rheumatoid arthritis (RA) and chronic periodontitis (CP). This study was undertaken to evaluate whether the DNA methylation profile of the interleukin‐6 (IL‐6) gene promoter was unique to individuals with RA and CP. Methods: The study participants consisted of 30 patients with RA, 30 patients with CP, and 30 age‐, sex‐, and smoking status–balanced healthy controls. Genomic DNA isolated from peripheral blood was modified by sodium bisulfite and analyzed for DNA methylation levels of IL‐6 gene with direct sequencing. Levels of IL‐6 were determined by an enzyme‐linked immunosorbent assay. Results: The region of IL‐6 gene promoter from ?1200 to +27 bp was shown to contain 19 CpG motifs. The methylation levels of the CpG motif at ?74 bp were significantly lower in patients with RA and CP than those in controls (P = 0.0001). Both levels of serum IL‐6 and IL‐6 production by mononuclear cells were significantly different between individuals with and without the methylation at ?74 bp (P = 0.03). The +19 bp motif exhibited differential levels of the methylation among the groups, which was not associated with serum levels of IL‐6. The other 17 CpG motifs exhibited comparable levels of the methylation between the groups. Conclusion: These results suggest that hypomethylated status of a single CpG in the IL‐6 promoter region may lead to increased levels of serum IL‐6, implicating a role in the pathogenesis of RA and CP.     

A new and sensitive method for quantitative determination of helium in human blood by gas chromatography–mass spectrometry using naturally existing neon-21 as internal standard

Forensic Toxicology - In this study, we proposed a new sensitive quantitative method for detecting helium in human blood by gas chromatography–selected-ion monitoring (SIM)-mass spectrometry...     

A nationwide analysis of renal and patient outcomes for adults with lupus nephritis in Japan

Clinical and Experimental Nephrology - The prognosis of lupus nephritis (LN) has improved following the introduction of effective immunosuppressive therapy and progress in supportive care. This...     

Anal Canal Carcinoma in a Child With Disorders of Sex Development

Squamous cell carcinoma of the anal canal in children is rare. To date, the etiology and outcome of this condition have been not fully understood. Here, we report an 11‐year‐old child with anal canal cancer who had concomitant disorders of sex development. Radiotherapy followed by salvage surgery achieved disease‐free survival of 3 years. Since overexpression of cell cycle regulatory protein p16 was immunohistochemically evident in tumor tissue, human papillomavirus infection was considered as a causative factor in the carcinogenesis.     

Antibody‐mediated rejection after ABO‐incompatible pediatric living donor liver transplantation for propionic acidemia: A case report

We herein present the case of a four‐yr‐old boy with PA who developed AMR after ABO‐incompatible LDLT despite undergoing B cell desensitization using rituximab. Although the CD19+ lymphocyte count decreased to 0.1% nine days after the administration of rituximab, he developed a high fever which was accompanied by arthralgia due to a streptococcal infection 13 days after rituximab prophylaxis. After the clearance of the infection, he underwent ABO‐incompatible LDLT 36 days after the administration of rituximab. The CD19+ lymphocyte count just prior to LDLT was 1.2%. He developed AMR five days after LDLT, and the antidonor‐type IgM and IgG antibody titers increased to 1:1024 and 1:1024, respectively. He was treated by plasma exchange, IVIG, steroid pulse therapy, and rituximab re‐administration; however, his liver dysfunction continued. Despite intensive treatment, he died due to complicated abdominal hernia, acute renal failure, and ARDS. This case suggests that a streptococcal infection may induce the activation of innate immune responses; thus, additional desensitization therapy should be considered prior to ABO‐incompatible LDLT if B cell reactivation is suspected.