ABSTRACT
OBJECTIVES: To evaluate the performance of a dual-energy computed tomography (DECT) virtual non-calcium (VNCa) technique in the detection of edema-like marrow signal intensity (ELMSI) in patients with knee joint osteoarthritis (OA) compared to magnetic resonance imaging (MRI). METHODS: The study received local ethics board approval, and written informed consent was obtained. DECT and MRI were used to examine 28 knees in 24 patients with OA. VNCa images were generated by dual-energy subtraction of calcium. The knee joint was divided into 15 regions for ELMSI grading, performed independently by two musculoskeletal radiologists, with MRI as the reference standard. We also analyzed CT numbers through receiver operating characteristics and calculated cut-off values. RESULTS: For the qualitative analysis, we obtained CT sensitivity (Readers 1, 2 = 83.7%, 89.8%), specificity (Readers 1, 2 = 99.5%, 99.5%), positive predictive value (Readers 1, 2 = 95.3%, 95.7%), and negative predictive value (Readers 1, 2 = 97.9%, 98.7%) for ELMSI. The interobserver agreement was excellent (κ = 0.92). The area under the curve for Reader 1 and Reader 2 was 0.961 (95% CI 0.93, 0.99) and 0.992 (95% CI 0.98, 1.00), respectively. CT numbers obtained from the VNCa images were significantly different between regions with and without ELMSI (p < .001). CONCLUSIONS: VNCa images have good diagnostic performance for the qualitative and quantitative analysis of knee osteoarthritis-related ELMSI.
ABSTRACT
In a previous study, we reported a persistent reduction of F-actin puncta but a compensating increase in puncta size in the mouse hippocampus at 2 months after pilocarpine-induced status epilepticus (Epilepsy Res. 108 (2014), 379-389). However, the F-actin changes during the period of epileptogenesis remain unknown. This study was designed to examine the temporal and spatial changes of F-actin during the period of epileptogenesis in a pilocarpine-induced epilepsy model, primarily by the histological and TUNEL evaluation of cell loss, phalloidin detection of F-actin, and immunohistochemical analysis of glial reactions. The results demonstrated that F-actin continued to decrease after pilocarpine treatment, which was consistent in its time course with hippocampal neuronal death. Within different hippocampal subfields, the spatial changes of F-actin exhibited similar features. First, the F-actin puncta decreased in number. Thereafter, F-actin was transiently aggregated in dendritic shafts and neuronal cell bodies and eventually was completely lost in the degenerated neurons. The progressive changes of F-actin in the degenerating neurons reported in this study may help to elucidate a cytoskeletal mechanism that may link to the delayed cell loss that occurs during epileptogenesis.
Subject(s)
Actin Cytoskeleton/metabolism , Actins/metabolism , Hippocampus/pathology , Neurons/pathology , Status Epilepticus/pathology , Analysis of Variance , Animals , Calcium-Binding Proteins/metabolism , Cells, Cultured , Disease Models, Animal , Gene Expression Regulation/drug effects , Hippocampus/drug effects , In Situ Nick-End Labeling , Male , Mice , Mice, Inbred ICR , Microfilament Proteins/metabolism , Muscarinic Agonists/toxicity , Nerve Tissue Proteins/metabolism , Neurons/drug effects , Pilocarpine/toxicity , Status Epilepticus/chemically induced , Time FactorsABSTRACT
OBJECTIVE: To identify and characterize an unknown microorganism causing contamination in several mammalian cell cultures. METHODS: This bacterium was identified by 16S rRNA sequencing and studied by DAPI and DiOC6 (3) staining, Gram staining, acid-fast staining, and electron microscopy. The isolated bacterium was also used to infect host cells to observe antibiotic effectiveness and its relationship with host cells. RESULTS: The 16S rRNA sequence analysis shows that this rod-shaped microorganism belongs to the family Caulobacteraceae, class Alphaproteobacteria, and was most closely related to Phenylobacterium zucineum HLK1T strain. The bacterium collected in the "swimming" stage was Gram staining negative, but Gram staining positive in the "sessile" stage. Under the electron microscope both flagellated and non-flagellated types were found. So far, no antibiotics were effective to inhibit this microorganism. The contamination with this bacterium frequently led to failed resuscitation of thawed cells. We found that the cells resuscitated with the used culture supernatants were increased in number by 3-4 folds as compared to those resuscitated with freshly prepared media. CONCLUSION: Phenylobacterium may have a dimorphic life cycle including a swimming stage and a sessile stalked stage.
