Search results for "Kinesis"
showing 10 items of 39 documents
Profilin 1 is required for abscission during late cytokinesis of chondrocytes
2009
Profilins are key factors for dynamic rearrangements of the actin cytoskeleton. However, the functions of profilins in differentiated mammalian cells are uncertain because profilin deficiency is early embryonic lethal for higher eukaryotes. To examine profilin function in chondrocytes, we disrupted the profilin 1 gene in cartilage (Col2pfn1). Homozygous Col2pfn1 mice develop progressive chondrodysplasia caused by disorganization of the growth plate and defective chondrocyte cytokinesis, indicated by the appearance of binucleated cells. Surprisingly, Col2pfn1 chondrocytes assemble and contract actomyosin rings normally during cell division; however, they display defects during late cytokines…
Cell Cycle in Potentially Dedifferentiating Cereal Mesophyll Protoplasts Cultured in vitro. I. Abnormalities in Cycle Kinetics
1993
Summary Protoplasts isolated from immature and mature mesophyll of wheat and oats were cultured in vitro . The potential progression from G1 (G0) to G2, through mitosis and cytokinesis was analysed. The degree and speed of progression through the cell cycle depended on the species and the state of maturity of the tissue from which the protoplasts were derived. In all the protoplast populations that were tested at least initiation of DNA synthesis was detected by labelling nuclei with the thymidine-analogue, bromodeoxyuridine (BrdU). Protoplasts derived from mature leaf tissue of wheat appeared to be recalcitrant to reach G2. Wheat protoplasts derived from immature leaf tissue appeared to pr…
Chemo-orientation responses in hymenopteran parasitoids induced by substrate-borne semiochemicals
2013
Hymenopteran parasitoids can utilize substrate-borne semiochemicals released by conspecifics or by their hosts, increasing the likelihood of successful mating and host location. According to the literature, two substrate-borne chemo-orientation patterns can occur: (1) biased random searching, a non-directional reaction toward the chemicals (kinesis), and (2) trailfollowing searching, a directional response toward the source emitting the chemical compounds (taxis). These two different strategies can be adopted by parasitoids to locate hosts and mates. In host location, random searching is induced by allelochemicals indirectly associated with the host, whereas trail-following behavior is indu…
Micronucleus frequencies and clonogenic cell survival in TK6 cells exposed to changing dose rates under controlled temperature conditions.
2014
In most exposure scenarios the dose rate of exposure is not constant. Despite this, very little information exists on the possible biological effects of exposing cells to radiation under the conditions of a changing dose rate. The current study highlights interesting effects following exposure under these conditions.We constructed a new exposure facility that allows exposing cells inside an incubator and used it to irradiate human lymphoblastoid TK6 cells both after a moderate (0.48 Gy) and a high (1.1 Gy) dose, where the change in dose rate was, respectively, ≈ 17-fold (2.2-37 mGy/min) and ≈ 39-fold (2.7-106 mGy/min). Clonogenic survival and micronuclei (MN) induction were the chosen endpo…
Roles for ELMOD2 and Rootletin in ciliogenesis.
2021
AbstractELMOD2 is a GTPase activating protein (GAP) with uniquely broad specificity for ARF family GTPases. We previously showed that it acts with ARL2 in mitochondrial fusion and microtubule stability and with ARF6 during cytokinesis. Mouse embryonic fibroblasts deleted for ELMOD2 also displayed changes in cilia related processes including increased ciliation, multiciliation, ciliary morphology, ciliary signaling, centrin accumulation inside cilia, and loss of rootlets at centrosomes with loss of centrosome cohesion. Increasing ARL2 activity or overexpressing Rootletin reversed these defects, revealing close functional links between the three proteins. This was further supported by the fin…
Abnormal mitotic spindle assembly and cytokinesis induced by D-Limonene in cultured mammalian cells
2013
D-Limonene is found widely in citrus and many other plant species; it is a major constituent of many essential oils and is used as a solvent for commercial purposes. With the discovery of its chemotherapeutic properties against cancer, it is important to investigate the biological effects of the exposure to D-Limonene and elucidate its, as yet unknown, mechanism of action. We reported here that D-Limonene is toxic in V79 Chinese hamster cells in a dose-dependent manner. Moreover, to determine the cellular target of D-Limonene, we performed morphological observations and immunocytochemical analysis and we showed that this drug has a direct effect on dividing cells preventing assembly of mito…
Regulation of cytokinesis and its clinical significance.
2015
Dysregulation of the cell cycle leads to polyploid cells, which are classified into mononuclear or binuclear polyploid cells depending on the number of nuclei. Polyploidy is common in plants and in animals. Physiologically, polyploidy and binucleation are differentiation markers and also features of the aging process. In fact, although they provide multiple copies of genes required for survival, a negative correlation between growth capacity and polyploidy has been reported, and thus, suppression or reversal of this phenomenon may be a growth advantage. On the other hand, unscheduled polyploidization may cause genomic instability that might lead to neoplastic aneuploidy. The aim of this rev…
Hsp70 localizes differently from chaperone Hsc70 in mouse mesoangioblasts under physiological growth conditions
2008
Mouse A6 mesoangioblasts express Hsp70 even in the absence of cellular stress. Its expression and its intracellular localization were investigated under normal growth conditions and under hyperthermic stress. Immunofluorescence assays indicated that without any stress a fraction of Hsp70 co-localized with actin microfilaments, in the cell cortex and in the contractile ring of dividing cells, while the Hsc70 chaperone did not. Hsp70 immunoprecipitation assays confirmed that a portion of Hsp70 binds actin. Immunoblot assays showed that both proteins were present in the nucleus. After heat treatment Hsp70 and actin continued to co-localize in the leading edge of A6 cells but not on microfilame…
L'idrochinesiterapia nel recupero dell'arto superiore dopo allungamento dei flessori del gomito e asportazione di paraosteoartropatia di spalla in so…
2007
La spasticità, oltre a determinare alterazioni dei fisiologici schemi di movimento, siaccompagna a complicanze musoclo- scheletriche per le quali spesso si ricorre all'intervento chirurgico. La riabilitazione, partendo da un'accurata valutazione pre e postoperatoria del malato, da un lato mira al recupero e al mantenimento dell'articolarità, dall'altro al ripristino della motilità volontaria e della destrezza dei movimenti. L'idrochinesiterapia offre evidenti vantaggi nel trattamento di questi soggetti. In questo lavoro si espone la nostra esperienza su un paziente di 38 anni con esiti di trauma cranio-encefalico sottoposto dapprima ad intervento chirurgico sull'arto superiore ed in seguito…
7-Nitroindazole blocks conditioned place preference but not hyperactivity induced by morphine.
2003
The effects of 7-nitroindazole (7-NI), a neural nitric oxide synthase (nNOS) inhibitor, on spontaneous locomotor activity, morphine-induced hyperactivity, acquisition of place conditioning and morphine-induced conditioned place preference (CPP) were evaluated in male mice. In experiment 1, animals treated with 7-NI (25, 50 and 100 mg/kg), morphine (40 mg/kg) or morphine (40 mg/kg) plus 7-NI (25, 50 or 100 mg/kg) were placed in an actimeter for 3 h. In experiment 2, animals treated with the same drugs and doses were conditioned following an unbiased procedure. 7-NI did not affect the spontaneous locomotor activity or hyperactivity induced by morphine. However, the moderate and high doses of …