Delignification of subsidiary and guard cell walls of Picea abies (L.) Karst. by fumigation with ozone

Summary After fumigation with ozone, the exterior periclinal walls of the stomatal apparatus of Picea abies appear to be partially delignified, as in earlier experiments with SO₂. This shows up cytophotometrically as reduced UV absorption. Random samples from the stand named Wank in the Bavarian Alps clearly showed a relation between the degree of lignification of the stomatal cells and the grading of the respective trees in their damage classes. The significance of delignification for the regulatory capacity of the stomata is discussed, and a hypothesis is proposed for a specific disturbance of hydroregulation by ozone.     

Genetic aspects of hemifacial microsomia

Summary The majority of patients with hemifacial microsomia (HM) including Goldenhar syndrome are sporadic cases. The sporadic nature of this disorder is emphasized by the discordant occurrence of HM in one of female monozygotic twins reported here. Previous publications, however, also suggest autosomal dominant and autosomal recessive modes of inheritance. Possible formes frustes will also have to be considered when giving genetic counsel.     

Statistical and Economical Efficiency in Assessment of Liver Regeneration Using Defined Sample Size and Selection in Combination With a Fully Automated Image Analysis System

Quantification of liver regeneration is frequently based on determining the 5-bromo-2-deoxyuridine labeling index (BrdU-LI). The quantitative result is influenced by preanalytical, analytical, and postanalytical variables such as the region of interest (ROI). We aimed to present our newly developed and validated automatic computer-based image analysis system (AnalySIS-Macro), and to standardize the selection and sample size of ROIs. Images from BrdU-labeled and immunohistochemically stained liver sections were analyzed conventionally and with the newly developed AnalySIS-Macro and used for validation of the system. Automatic quantification correlated well with the manual counting result (r=0.9976). Validation of our AnalySIS-Macro revealed its high sensitivity (>90%) and specificity. The BrdU-LI ranged from 11% to 57% within the same liver (32.96 ± 11.94%), reflecting the highly variable spatial distribution of hepatocyte proliferation. At least 2000 hepatocytes (10 images at 200× magnification) per lobe were required as sample size for achieving a representative BrdU-LI. Furthermore, the number of pericentral areas should be equal to that of periportal areas. The combination of our AnalySIS-Macro with rules for the selection and size of ROIs represents an accurate, sensitive, specific, and efficient diagnostic tool for the determination of the BrdU-LI and the spatial distribution of proliferating hepatocytes. (J Histochem Cytochem 57:1075–1085, 2009)