Cytology of colorectal adenomas

A study of the cytological appearances of benign and malignant colorectal adenomatous polyps is reported. The aim of the study was to characterize the cytological features of adenomatous polyps and predict the likelihood of malignancy using cytology. A five grade classification of colorectal cytology has been developed and the characteristic appearances of cells from adenomatous polyps are described. The reproducibility of cytological diagnosis based on this classification has been tested in 120 smears from normal mucosa and adenomatous polyps (including polyp cancers). Correlation with histology was achieved in 88% and correlation of the cytological diagnosis between two observers was achieved in 84%. We conclude that cytology can be used reliably as an adjunct to histology in the assessment of malignancy of adenomatous polyps.     

A HD-ZIP transcription factor specifies fates of multicellular trichomes via dosage-dependent mechanisms in tomato

1. Download : Download high-res image (166KB)
2. Download : Download full-size image

     

Phenolic oxidase activities in glandular trichomes of Solanum berthaultii

Polyphenol oxidase and peroxidase activities were detected in foliar glandular trichomes of the wild, insect-resistant potato species, Solanum berthaultii. These enzyme activities may provide the basis for conversion of clear, viscous trichome exudate into a hard, brown substance which is formed rapidly after insect attack.     

Scanning electron microscopic investigation of the spermatophore and spermatozoa of the shrimp Farfantepenaeus subtilis (Decapoda: Penaeidae)

Scanning electron microscopy was used to describe the structure of the spermatozoon and spermatophore of Farfantepenaeus subtilis. The spermatophore showed characteristics similar to those of members of the subgenus Farfantepenaeus. This included an extensive glandular epithelium and a lack of a wing. The sperm mass, which was distributed at the periphery of the spermatophore, was surrounded by a large amount of acellular material. The spermatozoon has a spherical main body and a well-defined acrosomal region with a single spike, which was bent in some cells. The immotile sperm cells have an average length of 7.1?±?0.6?μm. Information on sperm location within the spermatophore will assist in the efficient extraction of the sperm mass during dissection.     

Telocytes in human oesophagus

Telocytes (TCs), a new type of interstitial cells, were identified in many different organs and tissues of mammalians and humans. In this study, we show the presence, in human oesophagus, of cells having the typical features of TCs in lamina propria of the mucosa, as well as in muscular layers. We used transmission electron microscopy (TEM), immunohistochemistry (IHC) and primary cell culture. Human oesophageal TCs present a small cell body with 2–3 very long Telopodes (Tps). Tps consist of an alternation of thin segments (podomers) and thick segments (podoms) and have a labyrinthine spatial arrangement. Tps establish close contacts (‘stromal synapses’) with other neighbouring cells (e.g. lymphocytes, macrophages). The ELISA testing of the supernatant of primary culture of TCs indicated that the concentrations of VEGF and EGF increased progressively. In conclusion, our study shows the existence of typical TCs at the level of oesophagus (mucosa, submucosa and muscular layer) and suggests their possible role in tissue repair.     

Optimal photon energy comparison between digital breast tomosynthesis and mammography: A case study

A comparison, in terms of the optimal energy that maximizes the image quality between digital breast tomosynthesis (DBT) and digital mammography (DM) was performed in a MAMMOMAT Inspiration system (Siemens) based on amorphous selenium flat panel detector. In this paper we measured the image quality by the signal difference-to-noise ratio (SDNR), and the patient risk by the mean glandular dose (MGD). Using these quantities we compared the optimal voltage that maximizes the image quality both in breast tomosynthesis and standard mammography acquisition mode. The comparison for the two acquisition modes was performed for a W/Rh anode filter combinations by using a 4.5 cm tissue equivalent mammography phantom. Moreover, in order to check if the used equipment was quantum noise limited, the relation of the relative noise with respect to the detector dose was evaluated. Results showed that in the tomosynthesis acquisition mode the optimal voltage is 28 kV, whereas in standard mammography the optimal voltage is 30 kV. The automatic exposure control (AEC) of the system selects 28 kV as optimal voltage both for DBT and DM. Monte Carlo simulations showed a qualitative agreement with the AEC selection system, since an optimal monochromatic energy of 20 keV was found both for DBT and DM. Moreover, the check about the noise showed that the system is not completely quantum noise limited, and this issue could explain the experimental slight difference in terms of optimal voltage between DBT and DM. According to these results, the use of higher voltage settings is not justified for the improvement of the image quality during a DBT examination.     

The effect of triacontanol on micropropagation and on secretory system of Thymus mastichina

Shoot multiplication of Thymus mastichina L. was achieved on media containing 0.1 mg l^–1 6-benzyladenine and/or 0.1 mg l^–1 indole-3-butyric acid, or in hormone-free medium (control). The growth of plantlets, the production and composition of the essential oil, the density and secretory stage of glandular hairs have been evaluated in the presence and absence of growth regulators and triacontanol. We observed a positive effect of triacontanol on the growth of micropropagated plantlets using different conditions. Media with different levels of BA, IBA and TRIA resulted in no differences in the composition of the essential oil produced by plantlets. The major components of the oil were 1,8-cineole and linalool. An increase in the oil yield was observed especially when triacontanol was added to hormone-free medium. There was no correlation between changes in the oil yield and glandular hairs density, but the yield was dependent on the secretory stage of the glands.     

The Development of Activity of Cell Wall Bound β-Fructofuranosidase with Ripening and Senescence of Tomato Fruit

Optically active trisubstituted and tetrasubstituted cyclopentanes, with proper functional groups of proper stereochemistry as precursors for chiral synthesis of brefeldin A and prostaglandins, were prepared stereoselectively from carbohydrate.