Lobar and segmental liver atrophy associated with hilar cholangiocarcinoma and the impact of hilar biliary anatomical variants: a pictorial essay

The radiological features of lobar and segmental liver atrophy and compensatory hypertrophy associated with biliary obstruction are important to recognise for diagnostic and therapeutic reasons. Atrophied lobes/segments reduce in volume and usually contain crowded dilated bile ducts extending close to the liver surface. There is often a “step” in the liver contour between the atrophied and non-atrophied parts. Hypertrophied right lobe or segments enlarge and show a prominently convex or “bulbous” visceral surface. The atrophied liver parenchyma may show lower attenuation on pre-contrast computed tomography (CT) and CT intravenous cholangiography (CT-IVC) and lower signal intensity on T1-weighted magnetic resonance imaging (MRI). Hilar biliary anatomical variants can have an impact on the patterns of lobar/segmental atrophy, as the cause of obstruction (e.g. cholangiocarcinoma) often commences in one branch, leading to atrophy in that drainage region before progressing to complete biliary obstruction and jaundice. Such variants are common and can result in unusual but explainable patterns of atrophy and hypertrophy. Examples of changes seen with and without hilar variants are presented that illustrate the radiological features of atrophy/hypertrophy

Rice-Specific Mitochondrial Iron-Regulated Gene (MIR) Plays an Important Role in Iron Homeostasis

Mitochondria utilize iron (Fe), but the proteins involved in mitochondrial Fe regulation are not characterized in plants. We cloned and characterized a mitochondrial iron-regulated (MIR) gene in rice involved in Fe homeostasis. MIR, when expressed in tobacco BY-2 cells, was localized to the mitochondria. MIR transcripts were greatly increased in response to Fe deficiency in roots and shoot tissue. MIR is not homologous to any known protein, as homologs were not found in the rice or Arabidopsis genome databases, or in the EST database for other organisms. Growth in the MIR T-DNA knockout rice mutant (mir) was significantly impaired compared to wild-type (WT) plants when grown under Fe-deficient or -sufficient conditions. Furthermore, mir plants accumulated more than twice the amount of Fe in shoot and root tissue compared to WT plants when grown under either Fe-sufficient or -deficient conditions. Despite the high accumulation of Fe in roots and shoots, mir plants triggered the expression of Fe-deficiency-inducible genes, indicating that mir may not be able to utilize Fe for physiological functions. These results clearly suggest that MIR is a rice-specific mitochondrial protein, recently evolved, and plays a significant role in Fe homeostasis.X112627sciescopu

Increasing CO2 threatens human nutrition

Dietary deficiencies of zinc and iron are a substantial global public health problem. An estimated two billion people suffer these deficiencies, causing a loss of 63 million life-years annually. Most of these people depend on C3 grains and legumes as their primary dietary source of zinc and iron. Here we report that C3 grains and legumes have lower concentrations of zinc and iron when grown under field conditions at the elevated atmospheric CO2 concentration predicted for the middle of this century. C3 crops other than legumes also have lower concentrations of protein, whereas C4 crops seem to be less affected. Differences between cultivars of a single crop suggest that breeding for decreased sensitivity to atmospheric CO2 concentration could partly address these new challenges to global health