Distribution of microtubules during regular and disturbed microsporogenesis and pollen grain development in Gagea lutea (L.) Ker.-Gaw.

The microtubular cytoskeleton in dividing microsporocytes and developing pollen grains of Gagea lutea (L.) Ker.-Gaw.(Liliaceae) was investigated with a modified indirect immunofluorescence method. Meiotic and mitotic stages were identified by DAPI staining. The microtubular cytoskeleton was compared in plants originating from natural localities and others grown in the laboratory. In natural conditions, microsporocytes and pollen grains of wild early-spring Gagea lutea plants are subjected to abiotic factors including cold exposure and lack of water. The persistent influence of these factors can disturb microtubular cytoskeleton functioning. The following disturbances were observed in the course of microsporogenesis and pollen development: abnormal chromosome configurations in the metaphase of meiosis I; abnormally divided dyads with irregular, radial microtubule systems around the nuclei; the formation of differently sized microspores with irregular shapes, and irregular division; and the formation of pollen grains with vacuoles abnormal for their development stage. Similar kinds of disturbances were observed after 1.5 months of cold treatment (4 ^{\circ}C) and drying in the laboratory. These abiotic factors simulated in laboratory conditions caused more disturbances in the course of microsporogenesis and produced more frequent defective pollen grains than in the sample that had experienced cold and drying in natural conditions

Embryogenesis in Sedum acre L.: structural and immunocytochemical aspects of suspensor development

The changes in the formation of both the actin and the microtubular cytoskeleton during the differentiation of the embryo-suspensor in Sedum acre were studied in comparison with the development of the embryo-proper. The presence and distribution of the cytoskeletal elements were examined ultrastructurally and with the light microscope using immunolabelling and rhodamine-phalloidin staining. At the globular stage of embryo development extensive array of actin filaments is present in the cytoplasm of basal cell, the microfilament bundles generally run parallel to the long axis of basal cell and pass in close to the nucleus. Microtubules form irregular bundles in the cytoplasm of the basal cell. A strongly fluorescent densely packed microtubules are present in the cytoplasmic layer adjacent to the wall separating the basal cell from the first layer of the chalazal suspensor cells. At the heart-stage of embryo development, in the basal cell, extremely dense arrays of actin materials are located near the micropylar and chalazal end of the cell. At this stage of basal cell formation, numerous actin filaments congregate around the nucleus. In the fully differentiated basal cell and micropylar haustorium, the tubulin cytoskeleton forms a dense prominent network composed of numerous cross-linked filaments. In the distal region of the basal cell, a distinct microtubular cytoskeleton with numerous microtubules is observed in the cytoplasmic layer adjacent to the wall, separating the basal cell from the first layer of the chalazal suspensor cells. The role of cytoskeleton during the development of the suspensor in S. acre is discussed

Zaburzenia w mikrosporogenezie i rozwoju ziarna pyłku Gagea lutea (L.) Ker.-Gaw. [Disturbances in microsporogenesis and pollen grain development in Gagea lutea (L.) Ker. Gaw.]

The meiotic division of microsporocytes and pollen grain development in Gagea lutea (L.) Ker.-Gaw. (Liliaceae) with fluorescence microscope (excitation light 400 nm) was observed after squashing the anthers in DAPI solution (fluorochrom dying DNA). Up to 70% of microsporocytes and pollen grains during the microsporogenesis and pollen grain development take a regular course. In the remaining microsporocytes and pollen grains (30%) the disturbances in course of both processes were observed. The most often observed disturbances are "late" chromosomes and a presence of micronuclei. The divisions of microsporocytes in the anther loculi show a big asynchrony, which, like the disturbances during the course of microsporogenesis and pollen grain development, may be caused by the external factors. The microsporogenesis takes place during autumn and winter months: the pollen grains develop in winter. At this time the dividing microsporocytes and developing pollen grains are under the influence of abiotic factors as low temperature and a lack of water. These factors disturb the formation of microtubular cytoskeleton of the dividing microsporocytes and pollen grains, which causes the formation of sterile pollen grains

Tissue reaction to the nickel implants in the guinea pigs

Objectives: The aim of the study was the assessment of local tolerance to nickel implants during 9 months observation in guinea pigs sensitized to nickel before implantation and non-sensitized ones. Materials and Methods: Three groups of guinea pigs were included in the study: 10 sensitized to nickel by the guinea pig maximization test; 10 previously nonsensitized and 10 in control group. In 20 animals (except control group) the nickel implants were inserted in the muscle of the back. After 9 months of observation, the animals were patch-tested with 5% nickel sulfate. Also percentage of eosinophils in peripheral blood was examined. Next, the tissue surrounding the implant and skin from the area of patch tests were collected for the histological examination. Results: In 70% of previously sensitized animals, the patch test confirmed the sensitivity to nickel. In 60% of previously non-sensitized animals, a positive reaction to nickel occurred. The results of patch tests in control group were negative. Percentage of eosinophils in peripheral blood was fourfold higher in animals sensitized to nickel than in control group. In histological examination, in the tissue surrounding the implant a dissimilarity concerning the intensity of cellular infiltration was observed between animals previously allergic and non-allergic to nickel. In the 2 of 10 previously sensitized guinea pigs quite severe inflammatory reactions in the inside of connective tissue capsule were noted which may indicate a local allergic reaction. The histological images of skin collected from the positive patch test site corresponded with the typical allergic contact dermatitis. Conclusions: Nickel implants may cause primary sensitization to nickel. The nature of the histological changes in the tissues around the implants in guinea pigs sensitized to nickel may correspond to an allergic reaction. The examination of percentage of eosinophils in blood of guinea pigs may be useful in assessing the allergenic activity of metal alloys containing nickel

Immunological determinants in a murine model of toluene diisocyanate-induced asthma

Objectives: Diisocyanates (DIC) are highly reactive, low-molecular-weight chemicals which are the leading cause of occupational asthma (OA). The aim of the study was to analyze certain aspects of the pathogenesis of allergic infl ammation in the airways induced by toluene diisocyanate (TDI) in an experimental model in mice. Materials and Methods: The experiment was carried out on 50 female BALB/cJ/Han/IMP mice, which were exposed by inhalation (intranasal and in the inhalation chamber) to toluene diisocyanate (2,4-TDI). After the experiment, the bronchoalveolar lavage fluid (BALF) was collected from the animals, and the composition of the induced infl ammatory cells, and the concentrations of certain cytokines (IL-4, IL-5, TNF-α) were evaluated. Results: The total number of cells in BALF of the examined group of mice was signifi cantly higher compared to the control mice. There was also a signifi cant increase in neutrophils and eosinophils in the study group compared to the controls. The number of lymphocytes and macrophages did not differ signifi cantly between the two groups. A statistically signifi cant increase in the level of TNF-α was shown to occur in the group exposed to toluene diisocyanate in comparison to the control group. The concentration of IL-4 increased in the study group, compared to the control one, but the differences did not reach the level of signifi cance, p > 0.05. Such difference was not observed for IL-5. Conclusions: We developed a murine model of TDI-induced asthma which caused the infl ux of infl ammatory cells like eosinophils and neutrophils in the bronchoalveolar lavage fl uid (BALF) in the TDI-treated mice. The increase of the concentration of some proinfl ammatory cytokines (TNF-α, IL-4) in BALF from the exposed mice was also observed

Krakow International Studies no. 3, 2016

Opracowania łączące temat bezpieczeństwa i procesów integracyjnych stosunkowo rzadko pojawiają się w literaturze, chociaż te zależności są oczywiste i dotyczą – pośrednio lub bezpośrednio – każdego podmiotu gospodarki światowej. Prezentowany numer „Krakowskich Studiów Międzynarodowych” właśnie tym zagadnieniom został poświęcony – chodzi zwłaszcza o różne wymiary bezpieczeństwa międzynarodowego w korelacji ze wzrostem powiązań handlowych między krajami, w tym również w ramach WTO. Zagadnienia szczegółowe poruszane przez autorów dotyczą ważnych i aktualnych problemów takich jak: kryzys migracyjny w Europie, bezpieczeństwo energetyczne UE, bezpieczeństwo i ochrona w transgranicznym ruchu towarowym w Unii Europejskiej, konkurencyjność w handlu międzynarodowym czy wreszcie projekcja siły Chińskiej Republiki Ludowej na Oceanie Indyjskim, ważnym strategicznie obszarze, który staje się również polem rywalizacji między wschodzącymi gospodarkami Chin i Indii. Tematyka publikowanych tekstów wynika z różnorodnych zainteresowań autorów i odzwierciedla wielowątkowość, złożoność i interdyscyplinarny charakter prezentowanych zagadnień