ABSTRACT
PURPOSE: This study was designed to determine the association between LSE, spondylolisthesis, facet arthropathy, lumbar canal stenosis, BMI, radiculopathy and bone marrow edema at conventional lumbar spine MR imaging. METHODS: This is a retrospective radiological study; 441 consecutive patients with low back pain (224 men and 217 women; mean age 57.3 years; mean BMI 26) underwent conventional lumbar MRI using a 1.5-T magnet (Avanto, Siemens). Lumbar MR images were reviewed by consensus for the presence of LSE, spondylolisthesis, facet arthropathy, lumbar canal stenosis, radiculopathy and bone marrow edema. Descriptive statistics and association studies were conducted using STATA software 11.0. Association studies have been performed using linear univariate regression analysis and multivariate regression analysis, considering LSE as response variable. RESULTS: The overall prevalence of LSE was 40%; spondylolisthesis (p = 0.01), facet arthropathy (p < 0.001), BMI (p = 0.008) and lumbar canal stenosis (p < 0.001) were included in the multivariate regression model, whereas bone marrow edema, radiculopathy and age were not. CONCLUSIONS: LSE is highly associated with spondylolisthesis, facet arthropathy and BMI, suggesting underestimation of its clinical impact as an integral component in chronic lumbar back pain. Longitudinal simultaneous X-ray/MRI studies should be conducted to test the relationship of LSE with lumbar spinal instability and low back pain.
Subject(s)
Bone Marrow Diseases/diagnostic imaging , Edema/diagnostic imaging , Low Back Pain/diagnostic imaging , Lumbar Vertebrae/diagnostic imaging , Magnetic Resonance Imaging , Radiculopathy/diagnostic imaging , Spinal Stenosis/diagnostic imaging , Spondylolisthesis/diagnostic imaging , Adolescent , Adult , Aged , Aged, 80 and over , Bone Marrow Diseases/complications , Edema/complications , Female , Humans , Low Back Pain/complications , Lumbosacral Region/diagnostic imaging , Male , Middle Aged , Radiculopathy/complications , Regression Analysis , Retrospective Studies , Spinal Stenosis/complications , Spondylolisthesis/complicationsABSTRACT
The relationships between the specific rate of nutrient consumption and biomass growth and between the specific rate of penicillin production and oxygen concentration in the broth are analyzed. The functional dependencies which have been obtained from the experimental data of industrial fermenters are used with the mass balances to develop a model of the behavior of semicontinous operations. The proposed model allows one to study the influence of some operational parameters. The obtained results agree with the data of industrial processes.
Subject(s)
Bacteriology/instrumentation , Penicillins/biosynthesis , Bacteria/cytology , Bacteria/growth & development , Bacteria/metabolism , Fermentation , Glucose/metabolism , Kinetics , Models, Biological , Oxygen/metabolism , Time FactorsABSTRACT
The role of fundamental parameters in the conduction of penicillin semicontinuous fermentations is analyzed. Biomass concentration, penicillin production, and main nutrient consumption are particularly studied. Furthermore, the conduction of the operation is simulated with regard to conditions of constant specific rate of growth and of constant oxygen concentration in the broth. An intermediate condition is also considered.
