Initial fixation of a finite element model of an AI-Hip cementless stem evaluated by micromotion and stress

Background  

This study investigated issues related to initial stability after stem fixation. Finite element models of the AI-Hip cementless stem were constructed for computer simulation.     

Assessment of inflamed synovial membrane in the knee joint by dynamic magnetic resonance imaging

Dynamic magnetic resonance imaging (dynamic MRI) was used to examine the synovial membrane in the knee joints of 15 patients with rheumatoid arthritis (RA) in order to investigate the relationship between pathological and MRI findings. Signal intensities in the regions of interest (ROI), identified as the synovial membrane of the suprapatellar pouch, were measured on MR images. Signal intensities at various times after the injection of contrast medium Gd–diethylenetriaminopentoacetic acid (Gd–DTPA) were normalized relative to the signal intensity at 80s, and designated as the normalized signal intensity (NSI). Pathological findings were quantified, and the types of inflamed synovial membrane were classified as either acute or chronic. A significant difference in NSI was observed between acute and chronic types (P 0.05). Dynamic MRI was capable of classifying acute and chronic RA by measuring NSI 20s after contrast medium injection. Dynamic MRI was therefore shown to be useful for assessing regional synovial inflammation.     

Diverse p53 gene aberration in hepatocellular carcinoma detected by dual-color fluorescence in situ hybridization

BACKGROUND AND AIM: In order to evaluate loss of the p53 gene more precisely, we performed dual-color fluorescence in situ hybridization (dual-color FISH) for chromosome 17 and p53 gene together with DNA polymorphism analysis of the p53 gene in hepatocellular carcinoma (HCC). METHODS: Dual-color FISH using probes specific for the centromere of chromosome 17 and the p53 gene was performed for 41 HCC and DNA polymorphism analysis was also performed for them. RESULTS: Of the 34 HCC tested by dual-color FISH, 20 had loss of at least one p53 gene (58.8%). In contrast, of the 32 HCC tested by DNA polymorphism analysis, 23 gave informative results, among which only eight had loss of heterozygosity (LOH) of the p53 gene (34.8%). Notably, among 14 cases positive for loss of the p53 gene by dual-color FISH, seven cases were negative for LOH of the p53 gene. Moreover, dual-color FISH revealed that the percentage of cells that lost at least one p53 gene increased as the HCC became less differentiated (P < 0.01), whereas LOH did not reveal any such correlation. CONCLUSIONS: These data suggest that loss of the p53 gene was present in a considerable number of HCC, and diversity of the p53 gene aberration increases with progression of HCC. Dual-color FISH is an effective method for detection of p53 gene aberration, and it can provide new insight into oncogenesis in HCC.     

Brief Report: Optogenetic regulation of embryo implantation in mice using photoactivatable CRISPR-Cas9

Embryo implantation is achieved upon successful interaction between a fertilized egg and receptive endometrium and is mediated by spatiotemporal expression of implantation-associated molecules including leukemia inhibitory factor (LIF). Here we demonstrate, in mice, that LIF knockdown via a photoactivatable CRISPR-Cas9 gene editing system and illumination with a light-emitting diode can spatiotemporally disrupt fertility. This system enables dissection of spatiotemporal molecular mechanisms associated with embryo implantation and provides a therapeutic strategy for temporal control of reproductive functions in vivo.     

Analysis of the Genetic Alterations in a Case of Juvenile Multiple Colon Carcinoma With Hypogammaglobulinemia

Background: We have previously reported the clinical characterization of a case of juvenile multiple colorectal carcinoma with hypogammaglobulinemia. Several recent studies have determined that agammaglobulinemia was caused by the loss of Brutons tyrosine kinase (Btk) function. However, any genetic alterations associated with carcinoma formation in individuals with this immunodeficient disease have not been reported.Methods: DNA from eight carcinoma tissues and nine adenoma tissues from this reported case were examined for mutations in p53 by single strand conformation polymorphism analysis, K-ras by mutant allele specific analysis, and replication error or loss of heterozygosity of the TP53 locus on chromosome #17.Results: We found that p53 and K-ras were mutated in the carcinoma tissues. However, each tumor showed unequal and diverse results.Conclusions: The progression of individual tumor was not due to a common genetic event caused directly under the influence of the primary disease at the genetic level.     

Establishment of rat model of acute staphylococcal osteomyelitis: relationship between inoculation dose and development of osteomyelitis

Introduction Many animal models of acute and chronic osteomyelitis have been developed. In these models, osteomyelitic lesions are induced using sclerosing agents and foreign bodies with bacterial strains. In the present rat model, these sclerosing agents were not used. We assessed the relationship between inoculation dose and histological, radiological, and microbiological changes in the acute phase (1 week after inoculation) using this rat osteomyelitis model.Materials and methods An experimental rat model of acute osteomyelitis was developed by direct inoculation of the virulent strain BB of Staphylococcus aureus into tibial bone without sclerosants. To examine the relationship between the inoculation dose of the bacteria and the progression of the osteomyelitis, the inoculated lesions were assessed for changes in histological, radiological, and bacteriological parameters at 1 week after infection. Serial dilutions of the bacteria [6×10¹ to 6×10⁵ colony-forming units (CFU)/5 l] suspended in saline or saline alone were inoculated into the proximal metaphysis of the tibia.Results Development of significant histological and radiological signs of osteomyelitis required an inoculum of at least 6×10³ CFU/5 l. The number of viable bacteria at the lesion reached a maximum of 6×10³ CFU/5 l.Conclusion These results suggest that strain BB induces the development of acute staphylococcal osteomyelitis with clear infective destruction in the tibia, and that our model may be applied to the identification of virulence factors in studies of posttraumatic osteomyelitis.     

Contributing factors affecting initial bony healing in interlocking nailings for femoral shaft fractures

The objective of this study was to evaluate bony healing and predict factors affecting bony healing of femoral fractures treated with interlocking nailing (ILN) in static or dynamic conditions, and in reamed or unreamed procedures. Seventy-four femoral fractures (69 patients) were initially stabilized with ILNs in static condition. Among these fractures, ten static ILNs were dynamized after approximately 6 (median 6.4, range 1–13) months because of poor fracture healing. Reamed ILNs were performed for 55 fractures and unreamed ILNs for 19 fractures. Clinical and roentgenograhic processes were analyzed with emphasis on whether or not ILNs were dynamized. To evaluate any significant contributing factors affecting the nonunion of femoral shaft fractures treated with ILNs, logistic regression analysis was done. The union rates of static ILNs and dynamized ILNs were 92% (59/64) and 70% (7/10) respectively, but there was no significant difference between them. Five nonunions were seen in reamed ILNs and three in unreamed ILNs. The predictive logistic regression equation for nonunion was as follows: Log 1-p/p=1.05 -1.20 × AO/ASIF fracture grade in the femur -3.07 × existence of multiskeletal trauma in lower extremity + 0.06 × age -1.11 × smoking history -0.3 × existence of polytrauma -0.626 × the severity of soft tissue injury ( p=0.002; each variable in the above equation was arranged according to the significant order). Among the variables, AO fracture grade (type C) in the femur and existence of multiskeletal trauma in lower extremity were significantly related to nonunion. Static ILN in most femoral shaft fractures does not inhibit the process of fracture healing. The following associated skeletal lesions were our concerns for nonunion and broken nail in static or dynamic ILNs: (1) C-type femoral fracture; and (2) existence of multiskeletal trauma, such as double lesions in the ipsilateral femur, floating knee injury, and bilateral femoral fractures.