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1.
Orphanet J Rare Dis ; 12(1): 72, 2017 04 20.
Article in English | MEDLINE | ID: mdl-28427469

ABSTRACT

BACKGROUND: Graves' orbitopathy (GO) is an autoimmune condition, which is associated with poor clinical outcomes including impaired quality of life and socio-economic status. Current evidence suggests that the incidence of GO in Europe may be declining, however data on the prevalence of this disease are sparse. Several clinical variants of GO exist, including euthyroid GO, recently listed as a rare disease in Europe (ORPHA466682). The objective was to estimate the prevalence of GO and its clinical variants in Europe, based on available literature, and to consider whether they may potentially qualify as rare. Recent published data on the incidence of GO and Graves' hyperthyroidism in Europe were used to estimate the prevalence of GO. The position statement was developed by a series of reviews of drafts and electronic discussions by members of the European Group on Graves' Orbitopathy. The prevalence of GO in Europe is about 10/10,000 persons. The prevalence of other clinical variants is also low: hypothyroid GO 0.02-1.10/10,000; GO associated with dermopathy 0.15/10,000; GO associated with acropachy 0.03/10,000; asymmetrical GO 1.00-5.00/10,000; unilateral GO 0.50-1.50/10,000. CONCLUSION: GO has a prevalence that is clearly above the threshold for rarity in Europe. However, each of its clinical variants have a low prevalence and could potentially qualify for being considered as a rare condition, providing that future research establishes that they have a distinct pathophysiology. EUGOGO considers this area of academic activity a priority.


Subject(s)
Rare Diseases/diagnosis , Rare Diseases/epidemiology , Europe , Graves Ophthalmopathy/diagnosis , Graves Ophthalmopathy/epidemiology , Graves Ophthalmopathy/metabolism , Humans , Practice Guidelines as Topic , Quality of Life , Rare Diseases/metabolism
2.
J Hazard Mater ; 318: 623-630, 2016 Nov 15.
Article in English | MEDLINE | ID: mdl-27475460

ABSTRACT

In this study we present a theoretical investigation of the molecular properties of nitrodibenzofurans (NDFs) and dinitrodibenzofurans (DNDFs) and their relation to mutagenic activity. Equilibrium geometries, relative energies, vertical ionization potentials (IP), vertical electron activities (EA), electronic dipole polarizabilities, and dipole moments of all NDFs and three DNDFs calculated by Density Functional Theory (DFT) methods are reported. The Ziegler/Rauk Energy Decomposition Analysis (EDA) is employed for a direct estimate of the variations of the orbital interaction and steric repulsion terms corresponding to the nitro group and the oxygen of the central ring of NDFs. The results indicate differences among NDF isomers for the cleavage of the related bonds and steric effects in the active site. The results show a good linear relationship between polarizability (<α>), anisotropy of polarizability (Δα), the summation of IR intensities (ΣIIR) and the summation of Raman activities (ΣARaman) over all 3N-6 vibrational modes and experimental mutagenic activities of NDF isomers in Salmonella typhimurium TA98 strain. The polarizability changes with respect to the νsNO+CN vibrational mode are in correlation with the mutagenic activities of NDFs and suggest that intermolecular interactions are favoured along this coordinate.

3.
Eur J Ophthalmol ; 17(1): 11-9, 2007.
Article in English | MEDLINE | ID: mdl-17294378

ABSTRACT

PURPOSE: To compare continuous full-time (24 hours per day) occlusion of the sound eye with full-time occlusion (24 hours per day) of the sound eye 1 day more than the years of age periodically alternating with occlusion of the amblyopic eye for 1 day, as treatments for profound strabismic amblyopia in children older than 5 years. METHODS: A total of 53 patients with visual acuity (VA) of 0.4 and less in the amblyopic eye (tested by crowded Landolt Cs) after previously being provided optimal optical correction were randomly assigned to receive either of the two patching regimens. VA and pattern reversal visual evoked potentials (PVEP) were recorded prospectively at 1-month intervals. Improvement in VA and the reduction in crowding difficulties (CD) were the main outcome measures of the treatment efficiency. RESULTS: Both treatment modalities were equally effective. Of the 51 subjects who completed the study, 21 (41.2%) were cured whereas 32 (62.7%) attained satisfactory improvement. Recovery of VA was related to age, with cure being obtained in 23.5% (4/17) and satisfactory improvement in 52.9% (9/17) of patients older than 9 years. Larger gain in VA influenced the stability of the vision over time. CONCLUSIONS: It can be concluded that in clinically monitored parameters both treatment modalities were equally effective without any statistical or clinical significance in the observed groups of patients. However, events like the ""trade-off"" effect, occurrence of occlusion amblyopia, or prolongation of PVEP latency of the sound eye indicate that full-time continuous occlusion possibly presents a more effective form of treatment.


Subject(s)
Amblyopia/therapy , Light , Sensory Deprivation , Adolescent , Adult , Amblyopia/physiopathology , Child , Evoked Potentials, Visual/physiology , Female , Follow-Up Studies , Humans , Male , Prospective Studies , Strabismus/physiopathology , Strabismus/therapy , Visual Acuity/physiology
4.
Adv Space Res ; 31(10): 2237-43, 2003.
Article in English | MEDLINE | ID: mdl-14686438

ABSTRACT

The assembly of the International Space Station (ISS) as a permanent experimental outpost has provided the opportunity for quality plant research in space. To take advantage of this orbital laboratory, engineers and scientists at the Wisconsin Center for Space Automation and Robotics (WCSAR), University of Wisconsin-Madison, developed a plant growth facility capable of supporting plant growth in the microgravity environment. Utilizing this Advanced Astroculture (ADVASC) plant growth facility, an experiment was conducted with the objective to grow Arabidopsis thaliana plants from seed-to-seed on the ISS. Dry Arabidopsis seeds were anchored in the root tray of the ADVASC growth chamber. These seeds were successfully germinated from May 10 until the end of June 2001. Arabidopsis plants grew and completed a full life cycle in microgravity. This experiment demonstrated that ADVASC is capable of providing environment conditions suitable for plant growth and development in microgravity. The normal progression through the life cycle, as well as the postflight morphometric analyses, demonstrate that Arabidopsis thaliana does not require the presence of gravity for growth and development.


Subject(s)
Arabidopsis/growth & development , Environment, Controlled , Hydroponics/instrumentation , Seeds/growth & development , Space Flight/instrumentation , Weightlessness , Air Conditioning , Arabidopsis/metabolism , Biomass , Carbon Dioxide/metabolism , Equipment Design , Ethylenes/metabolism , Evaluation Studies as Topic , Plant Growth Regulators/metabolism , Plant Transpiration/physiology , Seeds/metabolism
5.
Trends Plant Sci ; 6(12): 591-3, 2001 Dec.
Article in English | MEDLINE | ID: mdl-11738385
6.
Adv Space Res ; 27(5): 915-9, 2001.
Article in English | MEDLINE | ID: mdl-11594376

ABSTRACT

The typical response of plant organs to gravistimulation is differential growth that leads to organ bending. If the gravitropic stimulus is withdrawn, endogenous compensation of the graviresponse and subsequent straightening occur in some plants. For instance, autonomic straightening of Lepidium roots occurs when gravitropically-curved rootsare rotated on a clinostat (Stankovi et al., 1998a). To determine whether endogenous compensation of the graviresponse also occurs in space, microgravity-grown cress roots were laterally centrifuged in-flight and then returned to microgravity using Biorack hardware on a shuttle mission (STS-81). The cress roots were centrifuged at 4 different g-doses (0.1 x g and 1 x g for 15 or 75 min). All four treatments yielded varying degrees of root curvature. Upon removal from the centrifuge, roots in all four treatments underwent subsequent straightening in microgravity. This straightening resulted from a loss of gravitropic curvature in older regions of the root and the coordinated alignment of new growth. These results show that both microgravity and clinostat rotation on Earth are equivalent in stimulus withdrawal with respect to the induction of endogenous compensation of the curvature. Cress roots are the only plant organ shown to undergo compensation of the curvature in both microgravity and on a clinostat. The compensation of graviresponse in space rules out the hypothesis that the endogenous root straightening ("autotropism") represents a commitment to a pre-stimulus orientation with respect to gravity and instead suggests that there is a default tendency towards axiality following a withdrawal of a g-stimulus.


Subject(s)
Gravitropism/physiology , Lepidium/growth & development , Plant Roots/growth & development , Space Flight , Weightlessness , Centrifugation , Germination/physiology , Gravitation , Lepidium/physiology , Plant Roots/physiology , Rotation , Seeds , Time Factors
7.
Plant Sci ; 160(2): 185-196, 2001 Jan 05.
Article in English | MEDLINE | ID: mdl-11164590

ABSTRACT

The bulk of our knowledge concerning the plant cytoskeleton has come primarily from the use of techniques and probes derived from animal research. However, in comparison with animal tissues, relatively few plant cytoskeleton proteins have been identified. We presume this is not because the plant cytoskeleton is really made up of such few proteins, but rather that only rarely have attempts been made to identify plant-specific cytoskeleton proteins, using plant-specific methods. Here we outline methods that we have developed both for the isolation and identification of novel cytoskeleton proteins as well as for the visualization of novel filamentous structures in plant cells, and we describe several novel cytoskeleton proteins and two novel cytoskeleton structures, 'nanofilaments' and 'nanotubules'. We postulate that use of such approaches will lead to a rapid expansion of our knowledge of the plant cytoskeleton.

8.
Panminerva Med ; 42(1): 17-21, 2000 Mar.
Article in English | MEDLINE | ID: mdl-11019599

ABSTRACT

BACKGROUND: Serum alpha 1-antitrypsin (alpha 1AT) antigen concentration is elevated in malignancies as the result of acute phase reaction. In the present study, we examined whether the alpha 1AT elevation in monoclonal gammopathies was accompanied by an adequate increase of its functional activity. METHODS: In this case-control study, serum alpha 1AT concentration was measured in 187 ambulatory patients with monoclonal gammopathies and 320 healthy blood donors matched according to sex and age. The alpha 1AT antigen concentration was assayed by immunonephelometry, whereas its functional activity was measured as trypsin inhibitory capacity (TIC). The specific alpha 1AT inhibitory activity (SIA) was calculated, defined as the TIC/antigen concentration ratio. RESULTS: The alpha 1AT antigen concentrations obtained in the patients' samples were very significantly higher as compared with the corresponding values in the control group (mean +/- SD = 134 +/- 41.9% of normal, p < 0.001). However, the TIC values were higher in the patients than in the healthy controls only by 4% (104 +/- 23.8%, p < 0.05). The specific alpha 1AT activity was very significantly lower in the patients, as compared with the controls (p < 0.001), indicating that serum alpha 1AT in monoclonal gammopathies was partially inactive. CONCLUSIONS: As poor correlation between the TIC values and the antigen concentrations was obtained in the patient group as well as the decreased specific alpha 1AT activities, the TIC values in patients with monoclonal gammopathies should be interpreted with caution.


Subject(s)
Paraproteinemias/blood , alpha 1-Antitrypsin/analysis , Adult , Aged , Case-Control Studies , Female , Humans , Male , Middle Aged , Osmolar Concentration , Reference Values , Trypsin/metabolism
10.
Vojnosanit Pregl ; 57(5): 37-41, 2000.
Article in Serbian | MEDLINE | ID: mdl-11213673

ABSTRACT

The aim was to evaluate the influence of red blood cells (RBC) transfusion on the development of cytotoxic antibodies (C-Ab) in patients subjected to hemodialyses (HD) and planned for the kidney transplantation. The group of 71 HD patients, of mean age 42 years (19-65), 48 males and 23 females, planned for the kidney information was examined. Out of 71 HD patients, only 42 (59.19%) HD patients (group I) received subcutaneously recombinant human erythropoietin--rhuEPO (Eprex--epoetin-alpha or Recormon SE--epoetin-beta in dosage of 4,000 IU during every HD; i.e. one to three times a week) and they were not treated by RBC transfusion. The other 29 (40.85%) HD patients (group II) received RBC transfusion: 18 (62.07%) HD patients received < 10 units 18 of RBC, 8 (27.59%) HD patients received 10-20 units of RBC; 3 (10.35%) HD patients received > 20 units of RBC. Testing of C-Ab was done in all patients every three months by standard lymphocytotoxicity test on the panel from 20 different lymphocyte donors with definite class I phenotype of antigen HLA. C-Ab was not found in HD patients who were not treated by RBC transfusion. Out of 18 HD patients who received < 10 units of RBC only 3 (16.67%) HD patients developed C-Ab; out of 8 HD patients who received 10-20 units of RBC, in 4 (50%) patients was proved C-Ab; and C-Ab was proved in all 3 HD patients who received > 20 units of RBC. RhuEPO administration is very important for the transfusiologic treatment of HD patients; especially those who are planned for the kidney transplantation. Development of C-Ab is in direct correlation with the number of transfunded units of RBC. HD patients who received 10 or more units of RBC were at great risk to develop C-Ab.


Subject(s)
Anemia/therapy , Antibodies/blood , Cytotoxicity, Immunologic , Erythrocyte Transfusion , HLA Antigens/immunology , Renal Dialysis , Adult , Aged , Anemia/etiology , Erythropoietin/therapeutic use , Female , Humans , Male , Middle Aged , Recombinant Proteins , Renal Dialysis/adverse effects
11.
Planta ; 212(1): 60-6, 2000 Dec.
Article in English | MEDLINE | ID: mdl-11219584

ABSTRACT

Localized wounding of one leaf in intact tomato (Lycopersicon esculentum Mill.) plants triggers rapid systemic transcriptional responses that might be involved in defense. To better understand the mechanism(s) of intercellular signal transmission in wounded tomatoes, and to identify the array of genes systemically up-regulated by wounding, a subtractive cDNA library for wounded tomato leaves was constructed. A novel cDNA clone (designated LebZIP1) encoding a DNA-binding protein was isolated and identified. This clone appears to be encoded by a single gene, and belongs to the family of basic leucine zipper domain (bZIP) transcription factors shown to be up-regulated by cold and dark treatments. Analysis of the mRNA levels suggests that the transcript for LebZIP1 is both organ-specific and up-regulated by wounding. In wounded wild-type tomatoes, the LebZIP1 mRNA levels in distant tissue were maximally up-regulated within only 5 min following localized wounding. Exogenous abscisic acid (ABA) prevented the rapid wound-induced increase in LebZIP1 mRNA levels, while the basal levels of LebZIP1 transcripts were higher in the ABA mutants notabilis (not), sitiens (sit), and flacca (flc), and wound-induced increases were greater in the ABA-deficient mutants. Together, these results suggest that ABA acts to curtail the wound-induced synthesis of LebZIP1 mRNA.


Subject(s)
DNA-Binding Proteins/genetics , Leucine Zippers/genetics , Plant Proteins/genetics , Solanum lycopersicum/genetics , Transcription Factors/genetics , Zinc Fingers/genetics , Abscisic Acid/physiology , Amino Acid Sequence , Base Sequence , Basic-Leucine Zipper Transcription Factors , Cloning, Molecular , DNA, Complementary , DNA, Plant , G-Box Binding Factors , Gene Dosage , Gene Expression Regulation, Plant , Molecular Sequence Data , RNA, Messenger/metabolism , Sequence Homology, Amino Acid
12.
Vojnosanit Pregl ; 57(4): 387-92, 2000.
Article in Serbian | MEDLINE | ID: mdl-11521462

ABSTRACT

A total of 40 kidney transplantations (37 males and 3 females) from living donors (Group I) and 10 kidney transplantations (6 males and 4 females) from cadavers (Group II) were performed in the period 1996-October 1999 at the Military Medical Academy (MMA). Lymphocytotoxic crossmatching was done before each kidney transplantation and results from all tests were negative for all recipients. All donors had the same blood group in ABO system as the recipients. In perioperative transfusion treatment (hemotherapy) determined quantity of filtered red blood cells (F-RBCs) and/or filtered platelets (F-PLT) were given to recipients according to intraoperative blood loss and their clinical state. Leukoreduction filters were used to prevent HLA alloimmunization. In only 4 (8%) recipients in group I transfusion therapy was not applied perioperatively. An average of 3.27 units of F-RBCs (929.44 mL) was used intraoperatively in 36 (72%) recipients in group I, an average of 1.9 units of F-RBCs (521 mL) was used before kidney transplantation in 10 (20%) recipients in group I and an average of 2.65 units of F-RBCs (739.23 mL) was used postoperatively in 26 (52%) recipients. In all recipients from group II transfusion therapy was applied perioperatively. An average of 3.4 units of F-RBCs (953 mL) was used intraoperatively. An average of 4.9 units (1.328 mL) and an average of 1.4 units of F-PLT were used postoperatively. All recipients well tolerated the therapy and no adverse effects of the therapy were observed. The need for transfusion therapy intraoperatively was approximatively same in both recipient groups, while in recipients from cadavers need for transfusion support in posttransplantation period was much higher.


Subject(s)
Erythrocyte Transfusion , Kidney Transplantation , Platelet Transfusion , Female , Histocompatibility Testing , Humans , Kidney Transplantation/immunology , Male
13.
J Gravit Physiol ; 6(1): P21-2, 1999 Jul.
Article in English | MEDLINE | ID: mdl-11543010

ABSTRACT

Cytoplasmic calcium is a major regulator of plant metabolism and its levels are under strict control, but it increases rapidly and transiently after stress treatments such as cold and touch (Trewavas 1999). Gravity is also thought to affect Ca2+ levels, although one report, using fluorescence microscopy of Ca(2+)-binding dyes, showed no changes (Legue et al. 1997). However, in these studies Ca2+ could not be visualized for at least 1 min after gravistimulation and thus changes could have occurred more rapidly. In order to circumvent problems associated with the delay in taking readings imposed by the fluorescence microscopy techniques, we chose a different method using plants transgenic for the Ca(2+)-binding, light-emitting jellyfish protein aequorin (Knight & Knight 1995). We subjected Arabidopsis and tomato plants to heat-wounding, vibration and gravity stimulation and measured cytoplasmic Ca2+ levels. We also measured the levels of several transcripts after heat-wound and gravity stimulation to determine whether both treatments evoked the same changes.


Subject(s)
Arabidopsis/metabolism , Calcium/metabolism , Gravitation , Hot Temperature , Solanum lycopersicum/metabolism , Vibration , Aequorin/genetics , Aequorin/metabolism , Arabidopsis/cytology , Arabidopsis/genetics , Cytoplasm/metabolism , Gene Expression Regulation, Plant , Solanum lycopersicum/cytology , Solanum lycopersicum/genetics , Plants, Genetically Modified , Time Factors
14.
Exp Toxicol Pathol ; 51(6): 545-7, 1999 Nov.
Article in English | MEDLINE | ID: mdl-10661813

ABSTRACT

Alcoholism is a very important cause of congestive cardiomyopathy in man. The aim of this study was to examine a short-term effect of ethanol in rat cardiac muscle, using histologic, morphometric and biochemical methods. Experiments were carried out in Wistar male albino rats, divided into two groups: the control group consisting of eight animals receiving tap water, and the experimental group comprising eight animals received ethyl alcohol for ten days, in a single daily dose of 3 g ethanol/kg body weight, per os, using esophageal intubation. The mean volume weighted nuclear volume of cardiac myocytes was estimated by point sampled intercept method, by objective x 100. The mean cubed nuclear intercept length was multiplied by pi and divided by 3. For biochemical analysis, a 10% water tissue homogenate from the left ventricle was made. In the experimental group, the mean volume-weighted nuclear volume (15.08 +/- 5.20 microm3) was significantly lower than in the control group (51.32 +/- 7.83 microm3) (p < 0.001). The treatment of experimental animals with ethanol caused significant increase of aldolase (p < 0.0001) and aspartate transaminase (p < 0.05) activity in the rat cardiac tissue; at the same time, the enzyme activity of creatine phosphokinase, alanine transaminase and alkaline phosphatase were not changed in the experimental group compared to the control values. The amount of the glucose in the cardiac muscle was greater in the experimental group compared to the control animals. Our results suggest that there is depression of cardiomyocyte nuclei in experimental animals treated with ethanol. Alcohol intake results in the loss of Krebs cycle enzymes and as a consequence there is greater utilization of fatty acids for energy production.


Subject(s)
Central Nervous System Depressants/toxicity , Citric Acid Cycle/drug effects , Ethanol/toxicity , Myocardium/pathology , Alcoholism , Animals , Biometry , Fatty Acids/metabolism , Male , Myocardium/enzymology , Rats , Rats, Wistar
15.
Plant Physiol ; 117(3): 893-900, 1998 Jul.
Article in English | MEDLINE | ID: mdl-9662531

ABSTRACT

Few studies have documented the response of gravitropically curved organs to a withdrawal of a constant gravitational stimulus. The effects of stimulus withdrawal on gravitropic curvature were studied by following individual roots of cress (Lepidium sativum L.) through reorientation and clinostat rotation. Roots turned to the horizontal curved down 62 degrees and 88 degrees after 1 and 5 h, respectively. Subsequent rotation on a clinostat for 6 h resulted in root straightening through a loss of gravitropic curvature in older regions and through new growth becoming aligned closer to the prestimulus vertical. However, these roots did not return completely to the prestimulus vertical, indicating the retention of some gravitropic response. Clinostat rotation shifted the mean root angle -36 degrees closer to the prestimulus vertical, regardless of the duration of prior horizontal stimulation. Control roots (no horizontal stimulation) were slanted at various angles after clinostat rotation. These findings indicate that gravitropic curvature is not necessarily permanent, and that the root retains some commitment to its equilibrium orientation prior to gravitropic stimulation.


Subject(s)
Brassicaceae/growth & development , Gravitropism/physiology , Plant Roots/growth & development , Rotation , Gravitation , Image Processing, Computer-Assisted , Video Recording
16.
Physiol Plant ; 102(2): 328-35, 1998 Feb.
Article in English | MEDLINE | ID: mdl-11542950

ABSTRACT

Segments of organs that have undergone gravitropic curvature later straighten during the course of gravitropism or after the g-vector becomes randomized on a clinostat. Little is known about the mechanism underlying these and perhaps related phenomena which have been described with various overlapping terms such as autotropism, autotropic straightening, automorphosis, automorphogenesis, automorphic curvature, and gravitropic straightening. The types of phenomena that historically have been named by the above terms are reviewed critically with respect to an interaction with gravitropism. We suggest that the term "autotropism" should not be applied to the phenomenon of organ straightening that occurs during the course of gravitropism, since this straightening is part of a complex series of local growth adjustments overall through time, and since this phenomenon is not itself a tropistic response to a directional exogenous stimulus. It is suggested that the term autotropism should be used only for the phenomenon of organ straightening that occurs after the g-vector is randomized on a clinostat or withdrawn in the microgravity conditions of spaceflight. Usage of the term automorphogenesis is most appropriate for describing curvatures or orientations that result from morphological relationships such as in nastic curvatures.


Subject(s)
Gravitropism , Plant Development , Space Flight , Terminology as Topic , Tropism , Weightlessness , Cotyledon/growth & development , Plant Physiological Phenomena , Rotation
17.
Acta Physiol Plant ; 19(4): 571-6, 1997.
Article in English | MEDLINE | ID: mdl-12296361

ABSTRACT

When one leaf of a tomato plant is electrically-stimulated or heat-wounded, proteinase inhibitor genes are rapidly up-regulated in distant leaves. The identity of the systemic wound signal(s) is not yet known, but major candidates include hormones transmitted via the phloem or the xylem, the electrically-stimulated self-propagating electrical signal in the phloem (the action potential, AP), or the heat-wound-induced surge in hydraulic pressure in the xylem evoking a local change in membrane potential in adjacent living cells (the variation potential, VP). In order to discriminate between these signals we have adopted two approaches. The first approach involves applying stimuli that evoke known signals and determining whether these signals have similar effects on the "model" transcripts for proteinase inhibitors (pin) and calmodulin (cal). Here we show that a heat wound almost invariably evokes a VP, while an electrical stimulation occasionally evokes an AP, and both of these signals induce accumulation of transcripts encoding proteinase inhibitors. The second approach involves identifying the array of genes turned on by heat-wounding. To this end, we have constructed a subtractive library for heat-wounded tissue, isolated over 800 putatively up-regulated clones, and shown that all but two of the fifty that we have analyzed by Northern hybridization are, indeed, up-regulated. Here we show the early kinetics of up-regulation of three of these transcripts in the terminal (4th) leaf in response to heat-wounding the 3rd leaf, about 5 cm away. Even though these transcripts show somewhat different time courses of induction, with one peaking at 30 min, another at 15 min, and another at 5 min after flaming of a distant leaf, they all exhibit a similar pattern, i.e., a transient period of transcript accumulation preceding a period of transcript decrease, followed by a second period of transcript accumulation.


Subject(s)
Arabidopsis Proteins , Gene Expression Regulation, Plant , Membrane Transport Proteins , Protease Inhibitors/metabolism , Signal Transduction/physiology , Solanum lycopersicum/genetics , Solanum lycopersicum/physiology , Action Potentials , Blotting, Northern , Calmodulin/metabolism , Carrier Proteins/metabolism , Electric Stimulation , Hot Temperature , Membrane Potentials , Membrane Proteins/metabolism , Plant Leaves/genetics , Plant Leaves/physiology , RNA, Messenger/metabolism , RNA, Plant/metabolism , Signal Transduction/genetics
18.
Plant Physiol ; 115(3): 1083-1088, 1997 Nov.
Article in English | MEDLINE | ID: mdl-12223859

ABSTRACT

A major candidate for intercellular signaling in higher plants is the stimulus-induced systemic change in membrane potential known as variation potential (VP). We investigated the mechanism of occurrence and long-distance propagation of VP in sunflower (Helianthus annuus L.) plants. Here we present evidence of the relationship among injury-induced changes in xylem tension, turgor pressure, and electrical potential. Although locally applied wounding did trigger a change in membrane potential, it evoked even faster changes in tissue deformation, apparently resulting from pressure surges rapidly transmitted through the xylem and experienced throughout the plant. Externally applied pressure mimicked flame wounding by triggering an electrical response resembling VP. Our findings suggest that VP in sunflower is not a propagating change in electrical potential and not the consequence of chemicals transmitted via the xylem, affecting ligand-modulated ion channels. Instead, VP appears to result from the surge in pressure in the xylem causing a change in activity of mechanosensitive, stretch-responsive ion channels or pumps in adjacent, living cells. The ensuing ion flux evokes local plasma membrane depolarization, which is monitored extracellularly as VP.

19.
Eur J Ophthalmol ; 6(3): 327-30, 1996.
Article in English | MEDLINE | ID: mdl-8908442

ABSTRACT

With a view to selecting the most suitable suture material for scleral wound management we made histological and tensiometric scar examinations after 7, 21 and 45 days on rabbits' eyes. Suture materials were also observed under the scanning electron microscope at the same intervals. Three suture materials (virgin silk 8.0, polyglycolic acid 7.0 and Nylon 8.0) were tested. Polyglycolic acid proved the most suitable suture material for this purpose.


Subject(s)
Eye Injuries, Penetrating/surgery , Insect Proteins , Sclera/injuries , Sutures , Animals , Eye Injuries, Penetrating/pathology , Nylons , Polyglycolic Acid , Proteins , Rabbits , Sclera/pathology , Sclera/surgery , Silk , Wound Healing
20.
FEBS Lett ; 390(3): 275-9, 1996 Jul 29.
Article in English | MEDLINE | ID: mdl-8706876

ABSTRACT

Tomato plants (Lycopersicon esculentum) accumulate proteinase inhibitor 2 (pin2) mRNA in response to insect attack, crushing and flaming in leaves distant from those treated. Most earlier work suggests that the systemic wound signals are chemical; here we try to determine whether electrical or physical (hydraulic) signals can also evoke pin expression. We used a mild flame to evoke a systemic hydraulic signal and its local electrical aftermath, the variation potential (VP), and we used an electric stimulus to evoke a systemic electrical signal, the action potential (AP). We determined the kinetic parameters of both the VP and AP. Flame-wounded plants essentially always exhibited major electrical responses throughout the plant and a several-fold increase in pin2 mRNA within 1 h. Electrically stimulated plants that generated and transmitted a signal (AP) into the analyzed leaf exhibited similarly large, rapid increases in pin2 mRNA levels. Plants which generated no signal, or signals of just a few microvolts, had unchanged levels of pin2 mRNA. Since the AP and VP both arrived in the receiving leaf before accumulation of pin2 mRNA began, we conclude that, in addition to the previously shown chemical signals, both hydraulically induced VPs and electrically induced APs are capable of evoking pin2 gene expression.


Subject(s)
Gene Expression Regulation, Plant , Plant Proteins/genetics , Protease Inhibitors/metabolism , Solanum lycopersicum/genetics , Solanum lycopersicum/physiology , Action Potentials , Blotting, Northern , Electric Stimulation , Hot Temperature , Membrane Potentials , Plant Proteins/biosynthesis , RNA, Messenger/metabolism , RNA, Plant/metabolism , RNA, Ribosomal/metabolism
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