Assessment of nerve involvement in the lumbar spine: agreement between magnetic resonance imaging, physical examination and pain drawing findings

<p>Abstract</p> <p>Background</p> <p>Detection of nerve involvement originating in the spine is a primary concern in the assessment of spine symptoms. Magnetic resonance imaging (MRI) has become the diagnostic method of choice for this detection. However, the agreement between MRI and other diagnostic methods for detecting nerve involvement has not been fully evaluated. The aim of this diagnostic study was to evaluate the agreement between nerve involvement visible in MRI and findings of nerve involvement detected in a structured physical examination and a simplified pain drawing.</p> <p>Methods</p> <p>Sixty-one consecutive patients referred for MRI of the lumbar spine were - without knowledge of MRI findings - assessed for nerve involvement with a simplified pain drawing and a structured physical examination. Agreement between findings was calculated as overall agreement, the p value for McNemar's exact test, specificity, sensitivity, and positive and negative predictive values.</p> <p>Results</p> <p>MRI-visible nerve involvement was significantly less common than, and showed weak agreement with, physical examination and pain drawing findings of nerve involvement in corresponding body segments. In spine segment L4-5, where most findings of nerve involvement were detected, the mean sensitivity of MRI-visible nerve involvement to a positive neurological test in the physical examination ranged from 16-37%. The mean specificity of MRI-visible nerve involvement in the same segment ranged from 61-77%. Positive and negative predictive values of MRI-visible nerve involvement in segment L4-5 ranged from 22-78% and 28-56% respectively.</p> <p>Conclusion</p> <p>In patients with long-standing nerve root symptoms referred for lumbar MRI, MRI-visible nerve involvement significantly underestimates the presence of nerve involvement detected by a physical examination and a pain drawing. A structured physical examination and a simplified pain drawing may reveal that many patients with "MRI-invisible" lumbar symptoms need treatment aimed at nerve involvement. Factors other than present MRI-visible nerve involvement may be responsible for findings of nerve involvement in the physical examination and the pain drawing.</p

Household energy usage, indoor air pollution and health

It seems likely that households have used energy for cooking for as long as there have been households. Globally, until the industrial revolution, this would have been principally woodfuel, agricultural waste (e.g. straw), dried dung and charcoal, with some regions relying on coal and peat. Archaeological evidence suggests the use of oil lamps for lighting appears to also stretch towards the beginnings of households, with ceramic decorated lamps dating from a few thousand years BC (Cam, 2014). Today, although difficult to estimate because traditional biomass energy use (for cooking and heating) is not accurately captured in energy statistics, bioenergy sources currently supply around 10-13% (1365 to 1775 million tonnes of oil equivalent annually) of the world's primary energy making biomass the world's fourth largest energy source (Hemstock & Singh, 2015; International Energy Agency, 2017). Around 70% (955 to 1242 million tonnes of oil equivalent annually) of this bioenergy use is in developing countries. It is used in the form of traditional woodfuel (fuelwood and charcoal), agricultural residues and dung to provide domestic energy services, mostly for cooking, by burning on open fires in 41% (Bonjour et at., 2013) of households in the world. These energy sources, along with coal and peat in some areas, are often inefficiently used and can be environmentally detrimental. They are deleterious to health when used traditionally and in inefficient domestic appliances in poorly ventilated cooking areas. Gender is also an issue as women are usually customarily responsible for cooking, meaning that women and children are at greater risk of exposure to high levels of indoor air pollution. In some least developed countries and in lower income households of developed countries, biomass provides more than 90% of total energy consumption for the populations who live in rural areas (Hemstock & Singh, 2015). A common issue affecting biomass, solid fossil fuel, and oil use for domestic energy services is that the products of combustion (smoke) are harmful to health if inhaled in substantial amounts over long periods of time, often leading to a range of illnesses such as pneumonia and significant impacts on increasing rates of mortality (WHO 2018; cf. Poddar and Chakrabarti 2016). Tragically, indoor air pollution is a key causal factor child pneumonia - a leading cause of death in children under five in many least developed countries, accounting for the deaths of around half a million children under the age of 5 years annually (Mortimer, 2017). This is clearly contrary to SDG3 Good Health and Wellbeing (UN 2015). Issues surrounding indoor air pollution and health are also directly linked to SDG7: Affordable and Clean Energy, which is related to fuel and technology choices available for domestic energy services; which are in turn linked to SDGs 1, 2, 4-6 and 8-13

Neuropathologic Correlates of Hippocampal Atrophy in the Elderly: A Clinical, Pathologic, Postmortem MRI Study

The volume of the hippocampus measured with structural magnetic resonance imaging (MRI) is increasingly used as a biomarker for Alzheimer's disease (AD). However, the neuropathologic basis of structural MRI changes in the hippocampus in the elderly has not been directly assessed. Postmortem MRI of the aging human brain, combined with histopathology, could be an important tool to address this issue. Therefore, this study combined postmortem MRI and histopathology in 100 elderly subjects from the Rush Memory and Aging Project and the Religious Orders Study. First, to validate the information contained in postmortem MRI data, we tested the hypothesis that postmortem hippocampal volume is smaller in subjects with clinically diagnosed Alzheimer's disease compared to subjects with mild or no cognitive impairment, as observed in antemortem imaging studies. Subsequently, the relations of postmortem hippocampal volume to AD pathology, Lewy bodies, amyloid angiopathy, gross infarcts, microscopic infarcts, and hippocampal sclerosis were examined. It was demonstrated that hippocampal volume was smaller in persons with a clinical diagnosis of AD compared to those with no cognitive impairment (P = 2.6×10−7) or mild cognitive impairment (P = 9.6×10−7). Additionally, hippocampal volume was related to multiple cognitive abilities assessed proximate to death, with its strongest association with episodic memory. Among all pathologies investigated, the most significant factors related to lower hippocampal volume were shown to be AD pathology (P = 0.0018) and hippocampal sclerosis (P = 4.2×10−7). Shape analysis allowed for visualization of the hippocampal regions most associated with volume loss for each of these two pathologies. Overall, this investigation confirmed the relation of hippocampal volume measured postmortem to clinical diagnosis of AD and measures of cognition, and concluded that both AD pathology and hippocampal sclerosis affect hippocampal volume in old age, though the impacts of each pathology on the shape of the hippocampus may differ

Polyamines Are Required for Virulence in Salmonella enterica Serovar Typhimurium

Sensing and responding to environmental cues is a fundamental characteristic of bacterial physiology and virulence. Here we identify polyamines as novel environmental signals essential for virulence of Salmonella enterica serovar Typhimurium, a major intracellular pathogen and a model organism for studying typhoid fever. Central to its virulence are two major virulence loci Salmonella Pathogenicity Island 1 and 2 (SPI1 and SPI2). SPI1 promotes invasion of epithelial cells, whereas SPI2 enables S. Typhimurium to survive and proliferate within specialized compartments inside host cells. In this study, we show that an S. Typhimurium polyamine mutant is defective for invasion, intracellular survival, killing of the nematode Caenorhabditis elegans and systemic infection of the mouse model of typhoid fever. Virulence of the mutant could be restored by genetic complementation, and invasion and intracellular survival could, as well, be complemented by the addition of exogenous putrescine and spermidine to the bacterial cultures prior to infection. Interestingly, intracellular survival of the polyamine mutant was significantly enhanced above the wild type level by the addition of exogenous putrescine and spermidine to the bacterial cultures prior to infection, indicating that these polyamines function as an environmental signal that primes S. Typhimurium for intracellular survival. Accordingly, experiments addressed at elucidating the roles of these polyamines in infection revealed that expression of genes from both of the major virulence loci SPI1 and SPI2 responded to exogenous polyamines and was reduced in the polyamine mutant. Together our data demonstrate that putrescine and spermidine play a critical role in controlling virulence in S. Typhimurium most likely through stimulation of expression of essential virulence loci. Moreover, our data implicate these polyamines as key signals in S. Typhimurium virulence