Comparison of dose distribution in IMRT and RapidArc technique in prostate radiotherapy

AimThe aim was to provide a dosimetric comparison between IMRT and RapidArc treatment plans with RPI index with simultaneous comparison of the treatment delivery time.BackgroundIMRT and RapidArc provide highly conformal dose distribution with good sparing of normal tissues. However, a complex spatial dosimetry of IMRT and RapidArc plans hampers the evaluation and comparison between plans calculated for the two modalities. RPI was used in this paper for treatment plan comparisons. The duration of the therapeutic session in RapidArc is reported to be shorter in comparison to therapeutic time of the other dynamic techniques. For this reasons, total treatment delivery time in both techniques was compared and discussed.Materials and methods15 patients with prostate carcinoma were randomly selected for the analysis. Two competitive treatment plans using respectively the IMRT and RapidArc techniques were computed for each patient in Eclipse planning system v. 8.6.15. RPIwin^® application was used for RPI calculations for each treatment plan.Additionally, total treatment time was compared between IMRT and RapidArc plans. Total treatment time was a sum of monitor units (MU) for each treated field.ResultsThe mean values of the RPI indices were insignificantly higher for IMRT plans in comparison to rotational therapy. Comparison of the mean numbers of monitor units confirmed that the use of rotational technique instead of conventional static field IMRT can significantly reduce the treatment time.ConclusionAnalysis presented in this paper, demonstrated that RapidArc can compete with the IMRT technique in the field of treatment plan dosimetry reducing the time required for dose delivery.     

A study on giant panda recognition based on images of a large proportion of captive pandas

1. As a highly endangered species, the giant panda (panda) has attracted significant attention in the past decades. Considerable efforts have been put on panda conservation and reproduction, offering the promising outcome of maintaining the population size of pandas. To evaluate the effectiveness of conservation and management strategies, recognizing individual pandas is critical. However, it remains a challenging task because the existing methods, such as traditional tracking method, discrimination method based on footprint identification, and molecular biology method, are invasive, inaccurate, expensive, or challenging to perform. The advances of imaging technologies have led to the wide applications of digital images and videos in panda conservation and management, which makes it possible for individual panda recognition in a noninvasive manner by using image‐based panda face recognition method.
2. In recent years, deep learning has achieved great success in the field of computer vision and pattern recognition. For panda face recognition, a fully automatic deep learning algorithm which consists of a sequence of deep neural networks (DNNs) used for panda face detection, segmentation, alignment, and identity prediction is developed in this study. To develop and evaluate the algorithm, the largest panda image dataset containing 6,441 images from 218 different pandas, which is 39.78% of captive pandas in the world, is established.
3. The algorithm achieved 96.27% accuracy in panda recognition and 100% accuracy in detection.
4. This study shows that panda faces can be used for panda recognition. It enables the use of the cameras installed in their habitat for monitoring their population and behavior. This noninvasive approach is much more cost‐effective than the approaches used in the previous panda surveys.

     

Wheat germ agglutinin binding sites on human urothelial cells of different grades of transformation

¹²⁵I-Wheat germ agglutinin (WGA) binding parameters of human urothelial cell lines of different grades of transformation (TGrll and TGrlll) were compared. The values of association constant (K_a) and the number of binding sites/cell for HCV29 (TGrll) cell line were about 3×10⁶M^–1 and over 4×10⁷, respectively. Two TGrlll cell lines, HCV29T and Hu549 revealed lower values for K_a, and considerably higher numbers of binding sites/cell (about 3×10⁸ and 2×10⁸, respectively). Binding of¹²⁵I-WGA to total cellular proteins resolved by SDS-PAGE and transferred to nitrocellulose showed multiple diffused bands in the range of 58–180 kDa. Some of these bands were characteristic for TGrll cells (124 kDa) or TGrlll cells (135 and 148 kDa).Abbreviations TGr transformation grade - WGA wheat germ agglutinin - sWGA succinylated wheat germ agglutinin - GlcNAc N-acetyl-d-glucosamine - BSA bovine serum albumin - SDS-PAGE sodium dodecyl sulphate polyacrylamide gel electrophoresis     

The altered expression of MHC-class II determinants on monocytes of cancer patients

Summary The expression of MHC class II determinants Ia.7 (detected by cross reactive mouse anti-Ia^k antibody) and HLA-DR on monocytes (MO) of gastric and colorectal cancer patients was examined. An increased proportion of MO bearing the Ia.7 determinant was found, while the number of MO expressing DR was not elevated. In gastric cancer patients the increased expression of the Ia.7 determinant was most pronounced in advanced cancer (stage IVA and IVB). The increased expression of this determinant was related to the presence of the tumour as the number of MO expressing Ia.7 decreased 6 months following surgical resection of the tumour. Further, the increased expression of Ia.7 on MO correlated with the tumour infiltration of the serosa. The Ia.7 determinants were mainly expressed on MO which also expressed the receptor for the Fc part of immunoglobulin. Immunostaining in cellular infiltrates surrounding the tumour revealed that Ia.7⁺ macrophages (MØ) were more numerous than in normal gastric mucosa and severe chronic gastritis and were mostly present in close proximity to tumour cells, while DR⁺ MØ were mainly localized within the stromal tissue of the tumour and their number was not increased in cancer infiltrates. These observations indicate that the Ia.7⁺ subpopulation of MØ may be involved in the anti-tumour response of the host.     

A putative replicative form of the abutilon mosaic virus (gemini group) in a chromatin-like structure

Summary The putative replicative form of the abutilon mosaic virus (AbMV), a geminivirus, was purified from infected plants. It was shown to consist of a bipartite genome of 2660 and 2640 bp. This double-stranded DNA has a closed or relaxed circular conformation and part of it is packed in nucleoprotein complexes with a chromatin-like structure. Similarities between the geminiviruses and the animal simian virus 40 are discussed against this back-ground.Cloning was performed under L2/B1 conditions according to the licence of the ZKBS 1526/1This article is based on a doctoral study by A.A. and T.F. in the Faculty of Biology, University of Hamburg     

Mixed pituitary tumours--effects of bromocriptine treatment: Parlodel MR and Parlodel LAR.

Majority of pituitary tumours secrete one of the named hormones: PRL, GH, ACTH, proopiomelanocortine, alpha and beta subunit of TSH, LH, and FSH. Some of those tumours secrete two or more hormones. The aim of this study was to determine the effect of bromocriptine (Parlodel MR and LAR) upon secretion of hormones and tumour size in 10 patients with mixed pituitary tumours. In all patients pituitary and peripheral hormones, CT scan and visual fields were examined before and after treatment with bromocriptine: Parlodel MR and LAR. Bromocriptine treatment decreased PRL secretion in all 10 patients; GH--in all 6 in whom it was increased; TSH--in 2, FSH--in 2 and alpha-subunit in all 6 in whom they were increased. In 5 patients treatment resulted in shrinkage of the tumour mass by 20 to 35%. In all examined subjects clinical improvement was achieved. Our results demonstrate that bromocriptine (Parlodel MR and LAR) is very effective and well tolerated in the treatment of patients with mixed pituitary tumours particularly those with hyperprolactinemia.     

Quantitative methods for determining the points of O-(carboxymethyl) substitution in O-(carboxymethyl)-guar

Two methods are described for locating the O-(carboxymethyl) groups in O-(carboxymethyl)guar. In Method I, O-(carboxymethyl)guar was depolymerized by methanolysis, the O-(carboxymethyl) groups were reduced, and the mixture of methyl glycosides and O-(2-hydroxyethyl)-substituted methyl glycosides was converted into a mixture of per-O-acetylated alditols and partially O-(2-acetoxyethyl)ated, partially O-acetylated alditols. Analysis of these alditols by gas-liquid chromatography-mass spectrometry allowed the positions of substitution of the O-(carboxymethyl) groups on the galactosyl groups and mannosyl residues to be determined. However, this method did not distinguish between O-(carboxymethyl) substitution on 4-linked and 4,6-linked mannosyl residues. This limitation was overcome by the more-detailed analysis provided by Method II, in which O-(carboxymethyl)guar was carboxyl-reduced, the product methylated, the glycosyl residues hydrolyzed, the sugars reduced, and the alditols acetylated to yield a mixture of partially O-acetylated, partially O-methylated alditols and partially O-acetylated, partially O-(2-methoxyethyl)ated, partially O-methylated alditols. These derivatives, when separated and quantitated by g.l.c., and identified by g.l.c.-m.s., gave a quantitative measure of every type of carboxymethyl substitution in guar.     

Effect of Drying on Unexposed Autoradiographic Emulsion in Relation to Background

Unexposed blanks prepared from Kodak AR 10 stripping film were dried by 3 methods: (1) fast, open drying with a fan for 25 min, (2) slow drying in a desiccator for 6 hr, and (3) very slow drying in a desiccator for 24 hr. The number of background grains depended on the mode of drying. Fast drying (method 1) gave 0.7 grain per 100 μ², slow drying (method 2) gave 0.33 grain; very slow drying (method 3), only 0.17 grain. The increase of background after fast drying is assumed to be caused by the rapid shrinkage of wet emulsion. This causes an increase in the intraemulsion pressure which, in turn, sensitizes the silver bromide crystals to cause an increase in the number of developable grains.     

Production and composition of phenylpyrrole metabolites prodcued by Pseudomonas cepacia

Summary In shaken cultures, a strain of Pseudomonas cepacia isolated from apple leaves produced pyrrolnitrin and four other phenylpyrrole antibiotics. The concentrations of these metabolites were determined at intervals for 7 days in three different media at two initial pH levels. Optical density measurements revealed maximum cell concentrations after 24 h in nutrient broth, after 48 h in King's B medium, and after 96 h in minimum salts solution. The effects caused by initiating fermentations at pH 5.8 rather than 7.0 were in most cases not dramatic, although in some instances, especially in minimum salts broth, higher concentrations of metabolites were produced with the lower initial pH. Concentrations of the phenylpyrrole antibiotics were greatly affected by choice of culture medium and incubation time. Concentrations of the two nitrophenyl metabolites, pyrrolnitrin and 2-chloropyrrolnitrin, rose throughout the 7-day incubation and were more than 20 times greater in minimum salts medium than in either King's B medium or nutrient broth. The maximum concentrations of each of the three aminophenyl metabolites (dichloroamino, trichloroamino and monochloroamino) occurred in different media, the monochloro compound in nutrient broth, the dichloro compound in Kings B medium and the trichloro compound in minimum salts medium. The time dependence of the concentrations of the five metabolites supports the proposed biosynthesis of these pyrroles from tryptophan by successive chlorinations followed by oxidation of the amino group at the end of the pathway.