Side effects of atypical antipsychotics: a brief overview

This paper reviews the available evidence concerning the side effects of atypical antipsychotics, including weight gain, type II diabetes mellitus, hyperlipidemia, QTc interval prolongation, myocarditis, sexual side effects, extrapyramidal side effects and cataract. Some recommendations about how to prevent and manage these side effects are also provided. It is concluded that atypical antipsychotics do not represent a homogeneous class, and that differences in side effects should be taken into account by clinicians when choosing an antipsychotic for an individual patient.     

Vacuolated plant cells as ideal osmometer: reversibility and limits of plasmolysis, and estimation of protoplasm volume in control and water-stress-tolerant cells

Abstract. The osmotic behaviour of vacuolated plant cells (adaxial epidermal cells of Allium cepa bulb scales, and epidermal as well as chloroplast containing subepidermal stem base cells of Pisum sativum) was studied over a wide range of CaCl₂ concentrations. The following results were obtained.

• a. Allium cepa and Pisum sativum plant cells behave as an ideal osmometer as far as plasmolytic contraction of the protoplast is concerned.
• b. The protoplasts of these cells could be plasmolysed to 15–45% of their original volume without the loss of membrane semi-permeability.
• c. Cells plasmolysed in 1.0 kmol m^?3 CaCl₂ could be completely deplasmolysed and upon deplasmolysis the cells resumed protoplasmic streaming.
• d. The above findings (a-c) indicate that during gradual plasmolysis and deplasmolysis membrane semi-permeability is maintained.
• e. At very high plasmolysing concentrations vacuoles covered with the tonoplast separated from the rest of the protoplasm in some cells whereas others showed systrophy. Extruded vacuoles were able to respond to osmotic shrinkage.
• f. The non-solvent space in Allium cells of about 3% also corresponded to the protoplasm volume calculated from the protoplast geometry (mean from results of direct measurement method and subtraction method).
• g. Subepidermal stem base cells of water-stress-tolerant Pisum plants had a 75% greater non-solvent space than the control cells indicating that a water-stress-tolerant cell may contain a larger amount of protoplasm and/or a vacuole with a higher content of colloidal material in the vacuole.
• h. Water-stress-tolerant cells showed greater tolerance to osmotic dehydration (volume reduction) than control cells.

     

Local endostatin treatment of gliomas administered by microencapsulated producer cells

We describe a technique for the treatment of malignant brain tumors based on local delivery of the anti-angiogenic protein endostatin from genetically engineered cells encapsulated in ultrapure sodium alginate. Alginate consists of L-guluronic and D-mannuronic acid, which in the presence of divalent cations forms an extended gel network, in which cells reside and remain immunoisolated, when implanted into the rat brain. Here, we show that endostatin-transfected cells encapsulated in alginate maintain endostatin secretion for at least four months after intracerebral implantation in rats. During the implantation period 70% of the encapsulated cells remained viable, as opposed to 85% in in vitro-cultured capsules. Rats that received transplants of BT4C glioma cells, together with endostatin-producing capsules (0.2 microg/ml per capsule), survived 84% longer than the controls. The endostatin released from the capsules led to an induction of apoptosis, hypoxia, and large necrotic avascular areas within 77% of the treated tumors, whereas all the controls were negative. The encapsulation technique may be used for many different cell lines engineered to potentially interfere with the complex microenvironment in which tumor and normal cells reside. The present work may thus provide the basis for new therapeutic approaches toward brain tumors.     

<Emphasis Type="Italic">Muscadinia rotundifolia</Emphasis> ‘Noble’ defense response to <Emphasis Type="Italic">Plasmopara viticola</Emphasis> inoculation by inducing phytohormone-mediated stilbene accumulation

Downy mildew (DM), one of the most devastating grape diseases worldwide, is caused by the biotrophic oomycete Plasmopara viticola (Pv). In general, grapevine responds to Pv infection with the accumulation of phytoalexins as part of the innate immune system, and diverse phytoalexins are induced on grapevines with different DM-resistance levels in response to Pv invasion. However, the regulation of phytoalexin biosynthesis during grapevine against Pv is still unclear. Herein, we detected stilbenes by UPLC-ESI-MS/MS and found that resveratrol was accumulated to higher level and earlier in the DM-immune Muscadinia rotundifolia ‘Noble’ than that in the DM-susceptible Vitis vinifera ‘Thompson Seedless’ after Pv inoculation. Additionally, a considerable amount of pterostilbene and ε-viniferin was found in ‘Noble’, while a little was detected in ‘Thompson Seedless’. Resveratrol was glycosylated into piceid both in ‘Noble’ and ‘Thompson Seedless’ after Pv inoculation. The qPCR analysis of gene expression indicated that the resveratrol-synthesis gene (STS) was induced by Pv inoculation earlier in ‘Noble’ than that in ‘Thompson Seedless’, while the pterostilbene-synthesis gene (ROMT) was induced in ‘Noble’ but not in ‘Thompson Seedless’ at all. The piceid-synthesis gene (GT) was generally up-regulated in both cultivars. Sequence analysis of STS, ROMT, and GT promoters revealed that they contained cis-regulatory elements responsive to phytohormones and pathogens. Following Pv inoculation, the level of SA, MeJA, and ABA was found to be consistently higher in ‘Noble’ than those in ‘Thompson Seedless’. The results of exogenous hormone elicitation further demonstrated that the accumulation of stilbenes was regulated by phytohormones. The earlier and higher accumulation of phytohormones and consequent induction of stilbene synthesis may play an important role in grapevine defense against downy mildew disease.     

Actin filaments regulate the adhesion between the plasma membrane and the cell wall of tobacco guard cells

During the opening and closing of stomata, guard cells undergo rapid and reversible changes in their volume and shape, which affects the adhesion of the plasma membrane (PM) to the cell wall (CW). The dynamics of actin filaments in guard cells are involved in stomatal movement by regulating structural changes and intracellular signaling. However, it is unclear whether actin dynamics regulate the adhesion of the PM to the CW. In this study, we investigated the relationship between actin dynamics and PM–CW adhesion by the hyperosmotic-induced plasmolysis of tobacco guard cells. We found that actin filaments in guard cells were depolymerized during mannitol-induced plasmolysis. The inhibition of actin dynamics by treatment with latrunculin B or jasplakinolide and the disruption of the adhesion between the PM and the CW by treatment with RGDS peptide (Arg-Gly-Asp-Ser) enhanced guard cell plasmolysis. However, treatment with latrunculin B alleviated the RGDS peptide-induced plasmolysis and endocytosis. Our results reveal that the actin depolymerization is involved in the regulation of the PW–CW adhesion during hyperosmotic-induced plasmolysis in tobacco guard cells.     

Overexpression of <Emphasis Type="Italic">AlTMP2</Emphasis> gene from the halophyte grass <Emphasis Type="Italic">Aeluropus littoralis</Emphasis> in transgenic tobacco enhances tolerance to different abiotic stresses by improving membrane stability and deregulating some stress-related genes

Herein, we report isolation of the AlTMP2 gene from the halophytic C4 grass Aeluropus littoralis. The subcellular localization suggested that AlTMP2 is a plasma membrane protein. In A. littoralis exposed to salt and osmotic stresses, the AlTMP2 gene was induced early and at a high rate, but was upregulated relatively later in response to abscisic acid and cold treatments. Expression of AlTMP2 in tobacco conferred improved tolerance against salinity, osmotic, H₂O₂, heat, and freezing stresses at the germination and seedling stages. Under control conditions, no growth or yield penalty were mentioned in transgenic plants due to the constitutive expression of AlTMP2. Interestingly, under greenhouse conditions, the seed yield of transgenic plants was significantly higher than that of non-transgenic (NT) plants grown under salt or drought stress. Furthermore, AlTMP2 plants had less electrolyte leakage, higher membrane stability, and lower Na⁺ and higher K⁺ accumulation than NT plants. Finally, six stress-related genes were shown to be deregulated in AlTMP2 plants relative to NT plants under both control and stress conditions. Collectively, these results indicate that AlTMP2 confers abiotic stress tolerance by improving ion homeostasis and membrane integrity, and by deregulating certain stress-related genes.     

Nectar and oleiferous trichomes as floral attractants in <Emphasis Type="Italic">Bulbophyllum saltatorium</Emphasis> Lindl. (Orchidaceae)

Although many Orchidaceae have deceit flowers that produce no reward, the most common reward, when present, is nectar. Bulbophyllum, however, is unusual in that the labellar secretions of most species investigated to date lack sugars, and, therefore, cannot be considered true nectar. The African species Bulbophyllum saltatorium is an exception in that it produces not only nectar but also possesses specialized, capitate oleiferous trichomes. The nectary of B. saltatorium is borne on the labellum and is represented by a deep, narrow, median longitudinal groove, having a small aperture, and flanked by trichomes. Isodiametric epidermal cells lining this groove secrete nectar which collects both in the groove and on the surface of the labellum. As well as a nectary, the labellum of B. saltatorium also bears three types of unicellular trichomes: the longest trichomes are borne distally and abaxially; the marginal ones form a rim around the entire labellum, and finally, massive, capitate trichomes occur proximally and adaxially. These are oleiferous, containing large quantities of oil which might function as precursors of volatile components of fragrance or provide a food-reward. To the best of our knowledge, this is the first time for such oleiferous trichomes to be described for Bulbophyllum. Therefore, apart from their color and markings, flowers of this species are able to attract pollinators in at least two, possibly three ways: food-reward in the form of nectar; fragrance; and possibly food-rewards in the form of food-hairs.     

Effect of mercury on pollen germination and tube growth in <Emphasis Type="Italic">Lilium longiflorum</Emphasis>

Pollen development and germination were adversely affected by the presence of mercury, whereas low-concentrations stimulated the whole procedure. Mercury caused morphological anomalies during the tube growth, characterized by irregularly increasing diameters and swelling tips. The main effect was the anomalous cell wall formation at the tip where a substantial number of organelles were found reducing the secretory vesicles. The dense organelle concentration caused a significant reduction of cytoplasmic movement integrity, and the cytosol streaming was gradually reduced or stopped completely. Electron dense, multilamellar myelin-like structures (MMS) of membranous material were frequently present, in close contact with plasmalemma or away from it. A loose network of fibrillar material and spherical aggregates mostly at the tip region were observed which progressively were loosened into the surrounding medium. Elevated mercury concentrations can affect plant reproduction, resulting in anomalies in gamete development and consequently loss of plant biodiversity.     

Pollen ultrastructure in <Emphasis Type="Italic">Aristolochia manshuriensis</Emphasis> and <Emphasis Type="Italic">A. contorta</Emphasis> (Aristolochiaceae)

Pollen ultrastructure has been studied in two relict and rare species of the genus Aristolochia, A. contorta Bunge and A. manshuriensis Kom. (Aristolochiaceae). Both species have inaperturate, spheroidal, sometimes distally monocolpate or distally bicolpate pollen grains. The equatorial and polar axes of pollen grain in A. manshuriensis are 48.5 and 44.0 μm, respectively. The percentage of defective pollen grains in A. manshuriensis is 3.4%. The fossulate, perforated exine is up to 2.3 μm in thickness; the sexine and the nexine are almost equal in thickness. In A. contorta, the equatorial axis of pollen grain is 36.6 μm: the defectiveness percentage, 24.5%. The exine is verrucate, up to 0.3 μm in thickness, while the sexine is two to three times thicker than the nexine. The pollen germination experiments have shown that pollen of A. manshuriensis, in contrast to A. contorta, can germinate in 10–20% sucrose at 22°С. These data and the high percentage of pollen defectiveness in A. contorta indicate that the androecium function in this species is reduced. The reduction of the androecium function is evidenced by a small amount of pollen grains in anthers or empty anthers and a high percentage of defective pollen grains.