Cholinesterases and choline acetyltransferase in the longitudinal muscle of the guinea pig ileum

Summary In order to gain insight into the possible role of the ACh-system in the smooth muscle cell, the presence of choline acetyltransferase, acetylcholinesterase and butyrylcholinesterase was studied in the longitudinal muscle of the guinea-pig ileum after the mechanical removal of Auerbach's plexus. Such treatment completely removes all nerve elements as confirmed by histochemistry and electron-microscopic examination.It was found that in the longitudinal muscle devoid of all nervous elements a substantial percentage of the activity of all three enzymes still remained. Ultrastructural localization of acetylcholinesterase and butyrylcholinesterase was observed on the sarcolemma, sarcoplasmic reticulum, nuclear membrane and invaginations of the sarcolemma. The localization of cholinesterases coincides with sites which are presumably involved in calcium movements during contraction and relaxation. It is well known that the depolarized smooth muscle responds to exogenous ACh with a reversible, calcium dependent contraction and it was suggested that ACh may act by increasing the influx of calcium through the cell membrane or by liberating calcium from its bound form.The presence of choline acetyltransferase and cholinesterase activities in the muscle cell proper, as well as the localization of cholinesterases on structures connected with calcium movements, support the coexistence of an intrinsic cholinergic mechanism in the smooth muscle.Part of this work was presented at the 6^th International Meeting of the International Society for Neurochemistry, Copenhagen, 1977     

A review of the West Palaearctic aphidiines (Hymenoptera: Braconidae: Aphidiinae) parasitic on Uroleucon spp., with the description of a new species

A review of aphidiine wasps (Hymenoptera: Braconidae) parasitizing the Uroleucon species in the West Palaearctic is presented. Eleven species are keyed and illustrated. In addition, a new hymenopteran parasitoid species: Praon nonveilleri n. sp. from Uroleucon inulicola (Hille Ris Lambers) infesting Inula ensifolia L., is described. The new species is diagnosed and illustrated. It belongs to the “dorsale-yomenaé” species group and was collected from the Djetinja canyon in Serbia and Montenegro. The aphidiines presented in this work were identified from 97 aphid taxons occurring on 236 plant taxons. Furthermore, 361 original parasitoid – host aphid – host plant associations of the species mentioned in the key are presented. Finally, phylogenetic relationships inside the “dorsale-yomenae” species group and related species were reconstructed using cladistic distance methods.     

Multinational study of oestrogen and progesterone receptor immunocytochemistry on breast carcinoma fine needle aspirates

?. P. Marin?ek, N. Nolde, I. Kardum‐Skelin, R. Nizzoli, B. Önal, T. Rezanko, E. Tani, K. T. Ostovi?, P. Vielh, F. Schmitt and G. Kocjan
Multinational study of oestrogen and progesterone receptor immunocytochemistry on breast carcinoma fine needle aspirates Objectives: To collect data on the variability of immunocytochemical (ICC) procedures used to detect oestrogen/progesterone receptors (ER/PR) on cytological material; to test the reproducibility of results; and to identify the crucial points in the ICC procedures that affect the result. Methods: Ten laboratories from eight countries participated in a two‐part study. In the first part, one of the participants (the coordinator) prepared and distributed cytospins from a fine needle aspirate of a primary breast carcinoma. Laboratories performed ICC staining for ER/PR according to their own methods on the test slides and in‐house positive controls. Slides were returned to the coordinator together with information on the preparation of positive control slides and the ICC methodology used. In the second part, obligatory methods of fixation and antigen retrieval were specified. Evaluation of results included grading the number of positive cells, staining intensity, background staining, cytoplasmic staining, sample condition and cellularity. Participants evaluated their own results, which were subsequently evaluated by the coordinator. Results: There was great variability in the preparation of slides for in‐house controls and ICC methodology. The outcome of ICC staining of in‐house control slides was excellent in two laboratories, adequate in three, sub‐optimal in four and inadequate in one. Only six obtained a positive reaction on the test slides and not all were of a high quality. Results of the second run were greatly improved in terms of cellularity of in‐house positive control slides, and scores for the percentage of stained cells and staining intensity of control and test slides. Cytospins and monolayer (ThinPrep^®) preparations were superior to direct smears; methods of fixation and antigen retrieval were the key points in the staining process. Conclusions: Our experience points to the need for guidelines for hormonal receptor determination and external quality control on cytological material, in order for cytological methods to be used in routine clinical practice with a suitable degree of confidence.     

The fate ofDrosophila hydei anlagen in heteroplastic transplantations

Summary Imaginal discs and larval brains of wildtype andlethal (3) giant larvae ofDrosophila hydei were transplanted into adult foreign hosts and examined after about 2 weeks. The transplants behaved very differently in different host species, viz. 6 species ofDrosophila, 5 other species of Diptera, and 3 species belonging to the Coleoptera or Dictyoptera, whereby the degree of incompatibility was more or less correlated with taxonomic distances. One notable exception was found in the cheese skipper,Piophila casei, an entirely compatible host.     

Nouveautés de la flore halophile du Littoral croate

Summary The archipelago opposite Senj (Croatian Coast) is very exposed to the Bora hurricanes accompanied by air dryness, salt spray, and periodic coast icing. Therefore the xerohalophytic flora of this area is very interesting. Four new taxa from there are described:Astragalus glacialis n. spec. subsp.glacialis s. s. and subsp.uraganicus n. subsp.,Allium horvatii n. spec., andPinus nigra Arn. subsp.croatica n. subsp., a stenoendemic relict near extinction on the isle of Prvi.     

Phenol removal from aqueous solutions by peroxidase extracted from horseradish

Horseradish peroxidase (HRP) is one of the most recently used enzymes in the process of enzymatic phenol removal. It has a catalytic ability over a broad range of pH, temperature and contaminant concentrations. In this study we revealed the possibility of successful use the crude peroxidase obtained from horseradish roots for the phenol removal from aqueous solutions in the presence of the low molecular polyethylene glycol (PEG 300) at room temperature (20°C) and pH 7.2. Reaction was monitored by direct measuring of the absorbance changes in a samples taken at certain time intervals from the reaction mixture. At the first time PEG 300 was shown to be a more stabilizing effect on crude HRP and provided a higher phenol removal in comparison with PEG 3350. Crude HRP used in these study demonstrated a greater resistance on phenol and hydrogen peroxide inactivation that allowed a higher phenol removal. The highest phenol removal was achieved when the concentration of PEG 300, phenol and hydrogen peroxide were 300 mg/L, 2.0 and 2.5 mM, respectively.     

Carotenoids: New Applications of “Old” Pigments

Carotenoids represent a large group of mainly red, orange, and yellow natural metabolites mainly involved in regulation of many metabolic processes. Carotenoids are beneficial for human health. Current study describes the importance, chemical composition and functioning of carotenoids. It is well known that carotenoids support pigments acting in light absorbance mechanisms during photosynthesis, and are known to protect the chlorophyll molecules from oxidative stress and reactive oxygen species (ROS) damage. Carotenoids are involved in signaling processes in plants, responses to environmental stresses, pollination, germination and reproduction, and development regulation. As nutrients of strong antioxidant activity that is primarily linked to their polyene molecular structure, the carotenoids are reported as immune-enhancement and anticancer agents, which are also involved in prevention of eye-, gastric and neurocognitive disorders, and in regulation of obesity and anti-ageing. Concerning the wide prospective applications of carotenoids as pharmaceuticals and nutraceuticals, there are some critical aspects associated with carotenoids’ bioavailability and challenges in their bioengineering. This mostly refers to the needs for identification and cloning of genes responsible for carotenoid biosynthesis and transformation and related development of transgenic carotenoid-rich crops. In the recent years, technologies of micro- and nanoencapsulation have addressed the needs of carotenoid entrapping to enhance their bioavailability, solubility and chemical stability, and to ensure the target delivery and manifestation of their strong antioxidant and other biological activity. Among standard and some advanced analytic tools for carotenoid determination (e.g., High performance liquid chromatography-HPLC, Liquid chromatography–mass spectrometry-LC-MS, Ultra high performance liquid chromatography-UHPLC, High-performance thin-layer chromatography-HPTLC and others), the vibrational spectroscopy techniques, primarily Raman spectroscopy coupled with chemometric modeling, opened a new era in carotenoid research and application.     

White‐ and blue‐light‐emitting dysprosium(III) and terbium(III)‐doped gadolinium titanate phosphors

Here we report the synthesis and structural, morphological, and photoluminescence analysis of white‐ and blue‐light‐emitting Dy³⁺‐ and Tm³⁺‐doped Gd₂Ti₂O₇ nanophosphors. Single‐phase cubic Gd₂Ti₂O₇ nanopowders consist of compact, dense aggregates of nanoparticles with an average size of ~25 nm for Dy³⁺‐doped and ~50 nm for Tm³⁺‐doped samples. The photoluminescence results indicated that ultraviolet (UV) light excitation of the Dy³⁺‐doped sample resulted in direct generation of white light, while a dominant yellow emission was obtained under blue‐light excitation. Intense blue light was obtained for Tm³⁺‐doped Gd₂Ti₂O₇ under UV excitation suggesting that this material could be used as a blue phosphor.