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1.
Khirurgiia (Mosk) ; (8): 69-75, 2021.
Article in Russian | MEDLINE | ID: mdl-34363448

ABSTRACT

OBJECTIVE: To demonstrate the approaches' implementation of specialized multidisciplinary and high-tech medical care in multistage complex treatment of patient with multiple trauma including combined severe trauma of the maxillofacial region such as minimally invasive surgical tactics with early and delayed osteosynthesis (e.g. selection of optimal surgical tactics within the periodization of traumatic disease concept). Moreover, the implementation of rational advanced intensive pathogenesis drug therapy with the prevention of infectious complications in cast of severe injuries. MATERIAL AND METHODS: The tactics, approaches and results of multistage complex specialized treatment of patient K., 56 years old who has got severe concomitant injuries to various areas of the body and extremities (including multiple maxillofacial trauma) after falling from a height are presented. CONCLUSION: Rational surgical tactics and the timely initiation (immediately after admission of the victim to 1st level trauma center) of pathogenesis intensive therapy with modern drugs and antibiotics contributed to the exclusion of infectious complications in the third period (the period of maximum likelihood of complications) of traumatic illness. Comprehensive treatment of a victim with multiple trauma based on the principles of specialized, multidisciplinary and high-tech medical care is able to provide a favorable clinical outcome - the recovery with the restoration of the damaged anatomical structures functionality and the absence of cosmetic defects.


Subject(s)
Accidental Falls , Multiple Trauma , Fracture Fixation, Internal/adverse effects , Humans , Middle Aged , Minimally Invasive Surgical Procedures , Multiple Trauma/therapy , Treatment Outcome
2.
Plant Biol (Stuttg) ; 20(3): 415-425, 2018 May.
Article in English | MEDLINE | ID: mdl-29274120

ABSTRACT

The abundance of calcareous soils makes bicarbonate-induced iron (Fe) deficiency a major problem for plant growth and crop yield. Therefore, Fe-efficient plants may constitute a solution for use on calcareous soils. We investigated the ability of the forage legume Sulla carnosa (Desf.) to maintain integrity of its photosynthetic apparatus under Fe deficiency conditions. Three treatments were applied: control, direct Fe deficiency and bicarbonate-induced Fe deficiency. At harvest, all organs of deficient plants showed severe growth inhibition, the effect being less pronounced under indirect Fe deficiency. Pigment analysis of fully expanded leaves revealed a reduction in concentrations of chlorophyll a, chlorophyll b and carotenoids under Fe deficiency. Electron transport rate, maximum and effective quantum yield of photosystem II (PSII), photochemical quenching (qP), non-photochemical quenching (qN) as well as P700 activity also decreased significantly in plants exposed to direct Fe deficiency, while qN was not affected. The effects of indirect Fe deficiency on the same parameters were less pronounced in bicarbonate-treated plants. The relative abundances of thylakoid proteins related to PSI (PsaA, Lhca1, Lhca2) and PSII (PsbA, Lhcb1) were also more affected under direct than indirect Fe deficiency. We conclude that S. carnosa can maintain the integrity of its photosynthetic apparatus under bicarbonate-induced Fe deficiency, preventing harmful effects to both photosystems under direct Fe deficiency. This suggests a high capacity of this species not only to take up Fe in the presence of bicarbonate (HCO3- ) but also to preferentially translocate absorbed Fe towards leaves and prevent its inactivation.


Subject(s)
Fabaceae/metabolism , Iron Deficiencies , Photosynthesis , Bicarbonates/pharmacology , Carotenoids/analysis , Chlorophyll/analysis , Chlorophyll A , Electron Transport , Fabaceae/growth & development , Photosystem I Protein Complex/analysis , Photosystem II Protein Complex/analysis , Plant Leaves/chemistry
3.
Urologiia ; (4): 12-6, 18, 2015.
Article in Russian | MEDLINE | ID: mdl-26665758

ABSTRACT

Remaining generally unchanged, urinary tract infection (UTI) treatment protocols require continuing monitoring due to growing antibiotic resistance and lowered immune status of the majority of patients. The article presents the results of a prospective observational program carried out the Russian Federation in to assess the effectiveness and safety of Ceforal®, Solutab® and Uro-Vaksom® in patients with recurrent uncomplicated lower urinary tract infections (FLORA). The results of the program suggest that Ceforal® Solutab® and Uro-Vaksom® administered as a part of routine clinical practice contribute to a significant reduction in the number of UTI recurrences and have a good safety profile. These findings support recommendation to use this treatment protocol in patients with recurrent UTI, taking into account individual and epidemiological features.


Subject(s)
Acyclovir/administration & dosage , Anti-Bacterial Agents/administration & dosage , Antiviral Agents/administration & dosage , Cefixime/administration & dosage , Urinary Tract Infections/drug therapy , Adult , Female , Humans , Middle Aged
4.
J Photochem Photobiol B ; 152(Pt B): 335-46, 2015 Nov.
Article in English | MEDLINE | ID: mdl-26321219

ABSTRACT

Comparative analysis of in vivo chlorophyll fluorescence imaging revealed that photosystem II (PSII) photochemical efficiency (Fv/Fm) of leaves of the Costata 2/133 pea mutant with altered pigment composition and decreased level of oligomerization of the light harvesting chlorophyll a/b-protein complexes (LHCII) of PSII (Dobrikova et al., 2000; Ivanov et al., 2005) did not differ from that of WT. In contrast, photosystem I (PSI) activity of the Costata 2/133 mutant measured by the far-red (FR) light inducible P700 (P700(+)) signal exhibited 39% lower steady state level of P700(+), a 2.2-fold higher intersystem electron pool size (e(-)/P700) and higher rate of P700(+) re-reduction, which indicate an increased capacity for PSI cyclic electron transfer (CET) in the Costata 2/133 mutant than WT. The mutant also exhibited a limited capacity for state transitions. The lower level of oxidizable P700 (P700(+)) is consistent with a lower amount of PSI related chlorophyll protein complexes and lower abundance of the PsaA/PsaB heterodimer, PsaD and Lhca1 polypeptides in Costata 2/133 mutant. Exposure of WT and the Costata 2/133 mutant to high light stress resulted in a comparable photoinhibition of PSII measured in vivo, although the decrease of Fv/Fm was modestly higher in the mutant plants. However, under the same photoinhibitory conditions PSI photochemistry (P700(+)) measured as ΔA820-860 was inhibited to a greater extent (50%) in the Costata 2/133 mutant than in the WT (22%). This was accompanied by a 50% faster re-reduction rate of P700(+) in the dark indicating a higher capacity for CET around PSI in high light treated mutant leaves. The role of chloroplast thylakoid organization on the stability of the PSI complex and its susceptibility to high light stress is discussed.


Subject(s)
Light-Harvesting Protein Complexes/chemistry , Light , Mutation , Photosystem I Protein Complex/antagonists & inhibitors , Pisum sativum/genetics , Pisum sativum/radiation effects , Protein Multimerization/genetics , Chlorophyll/metabolism , Chlorophyll A , Light-Harvesting Protein Complexes/metabolism , Pisum sativum/enzymology , Pisum sativum/metabolism , Photosystem I Protein Complex/chemistry , Photosystem I Protein Complex/metabolism , Protein Structure, Quaternary , Spectrometry, Fluorescence
5.
Urologiia ; (6): 52-57, 2015 Dec.
Article in Russian | MEDLINE | ID: mdl-28247681

ABSTRACT

This article presents results of a study conducted to identify the causes of stenosis in the region of vesico-urethral anastomosis (VUA) after radical prostatectomy (RP). Tissue specimens from removed prostates were evaluated in 115 prostate cancer patients with a favorable postoperative period (group 1) and 5 patients who develop VUA stenosis between 6 months to1 year after RP. It was found that in the group 1 inflammatory infiltration did not basically affect tumor growth zones, was mild and did not spread beyond the prostate. Patients of the group 2 had maximum inflammation, with the inflammatory infiltration localized in the prostate regions, both affected and not affected by the tumor, and periprostatically. Taking into account more severe inflammatory response in the prostate with extracapsular extension of the process and the involvement of periprostatic structures in patients who developed VUA stenosis after RP, compared to those without VUA stenosis, we can consider this phenomenon as a risk factor for stenotic complications in the vesico-urethral segment after RP.


Subject(s)
Inflammation , Prostatectomy , Urethral Stricture , Constriction, Pathologic , Humans , Inflammation/complications , Male , Prostatectomy/adverse effects , Prostatic Neoplasms/surgery , Risk Factors , Urethral Stricture/etiology
6.
Article in Russian | MEDLINE | ID: mdl-23672064

ABSTRACT

The article considers the morbidity endocrine, pathology included, of workers of nuclear power station and body-abled population of the district employed in other areas of professional activities. The statistically reliable exceeding of the level of primarily diagnosed endocrine morbidity in the group of working population of the district as compared with the group of workers of nuclear power station is established. In the compared groups, the structure of pathology of endocrine system is characterized by the prevalence of diseases of thyroid gland and obesity. The official statistics data reflects the level of morbidity of working population depending on appealability to curative preventive institutions, ratio and scope of the periodic medical examinations, availability of shop therapeutic service and possibility to involve physicians-specialists to health posts enterprises. Therefore, the foundation of enhancement of quality of medical care to workers is the improvemnent of organizational activities at the level of primary health care.


Subject(s)
Endocrine System Diseases/epidemiology , Nuclear Power Plants , Occupational Diseases/epidemiology , Occupational Exposure/adverse effects , Adult , Female , Humans , Male , Middle Aged , Obesity/epidemiology , Occupational Health/standards , Prevalence , Primary Health Care/organization & administration , Primary Health Care/standards , Quality of Health Care , Russia/epidemiology , Specialization , Thyroid Diseases/epidemiology
7.
J Exp Bot ; 64(1): 343-54, 2013 Jan.
Article in English | MEDLINE | ID: mdl-23183256

ABSTRACT

The effects of exposure to increasing manganese concentrations (50-1500 µM) from the start of the experiment on the functional performance of photosystem II (PSII) and photosystem I (PSI) and photosynthetic apparatus composition of Arabidopsis thaliana were compared. In agreement with earlier studies, excess Mn caused minimal changes in the PSII photochemical efficiency measured as F(v)/F(m), although the characteristic peak temperature of the S(2/3)Q(B) (-) charge recombinations was shifted to lower temperatures at the highest Mn concentration. SDS-PAGE and immunoblot analyses also did not exhibit any significant change in the relative abundance of PSII-associated polypeptides: PSII reaction centre protein D1, Lhcb1 (major light-harvesting protein of LHCII complex), and PsbO (OEC33, a 33 kDa protein of the oxygen-evolving complex). In addition, the abundance of Rubisco also did not change with Mn treatments. However, plants grown under excess Mn exhibited increased susceptibility to PSII photoinhibition. In contrast, in vivo measurements of the redox transients of PSI reaction centre (P700) showed a considerable gradual decrease in the extent of P700 photooxidation (P700(+)) under increased Mn concentrations compared to control. This was accompanied by a slower rate of P700(+) re-reduction indicating a downregulation of the PSI-dependent cyclic electron flow. The abundance of PSI reaction centre polypeptides (PsaA and PsaB) in plants under the highest Mn concentration was also significantly lower compared to the control. The results demonstrate for the first time that PSI is the major target of Mn toxicity within the photosynthetic apparatus of Arabidopsis plants. The possible involvement mechanisms of Mn toxicity targeting specifically PSI are discussed.


Subject(s)
Arabidopsis/drug effects , Arabidopsis/metabolism , Manganese/pharmacology , Photosystem I Protein Complex/antagonists & inhibitors , Photosystem II Protein Complex/antagonists & inhibitors , Arabidopsis/genetics , Arabidopsis/growth & development , Biomass , Electrophoresis, Polyacrylamide Gel , Light , Manganese/metabolism , Photosystem I Protein Complex/metabolism , Photosystem II Protein Complex/metabolism , Plant Leaves/drug effects , Plant Leaves/growth & development , Plant Leaves/radiation effects , Plant Roots/drug effects , Plant Roots/growth & development , Plant Roots/radiation effects , Temperature , Thermoluminescent Dosimetry
8.
Photosynth Res ; 113(1-3): 191-206, 2012 Sep.
Article in English | MEDLINE | ID: mdl-22843101

ABSTRACT

Exposure of control (non-hardened) Arabidopsis leaves to high light stress at 5 °C resulted in a decrease of both photosystem II (PSII) (45 %) and Photosystem I (PSI) (35 %) photochemical efficiencies compared to non-treated plants. In contrast, cold-acclimated (CA) leaves exhibited only 35 and 22 % decrease of PSII and PSI photochemistry, respectively, under the same conditions. This was accompanied by an accelerated rate of P700(+) re-reduction, indicating an up-regulation of PSI-dependent cyclic electron transport (CET). Interestingly, the expression of the NDH-H gene and the relative abundance of the Ndh-H polypeptide, representing the NDH-complex, decreased as a result of exposure to low temperatures. This indicates that the NDH-dependent CET pathway cannot be involved and the overall stimulation of CET in CA plants is due to up-regulation of the ferredoxin-plastoquinone reductase, antimycin A-sensitive CET pathway. The lower abundance of NDH complex also implies lower activity of the chlororespiratory pathway in CA plants, although the expression level and overall abundance of the other well-characterized component involved in chlororespiration, the plastid terminal oxidase (PTOX), was up-regulated at low temperatures. This suggests increased PTOX-mediated alternative electron flow to oxygen in plants exposed to low temperatures. Indeed, the estimated proportion of O(2)-dependent linear electron transport not utilized in carbon assimilation and not directed to photorespiration was twofold higher in CA Arabidopsis. The possible involvement of alternative electron transport pathways in inducing greater resistance of both PSII and PSI to high light stress in CA plants is discussed.


Subject(s)
Acclimatization/radiation effects , Arabidopsis/physiology , Electrons , Light , Photochemical Processes/radiation effects , Photosystem I Protein Complex/metabolism , Photosystem II Protein Complex/metabolism , Acclimatization/drug effects , Arabidopsis/drug effects , Arabidopsis/radiation effects , Carbon Dioxide/metabolism , Cold Temperature , Densitometry , Electron Transport/drug effects , Electron Transport/radiation effects , Fluorescence , Glyceraldehyde/pharmacology , Immunoblotting , Oxidation-Reduction/drug effects , Oxidation-Reduction/radiation effects , Photons , Plant Leaves/drug effects , Plant Leaves/metabolism , Plant Leaves/radiation effects , Stress, Physiological/drug effects , Stress, Physiological/radiation effects , Time Factors , Xanthophylls/metabolism
9.
Biochim Biophys Acta ; 1817(8): 1277-84, 2012 Aug.
Article in English | MEDLINE | ID: mdl-22465025

ABSTRACT

Exposure of wild type (WT) and plastocyanin coding petE gene deficient mutant (ΔpetE) of Synechococcus cells to low iron growth conditions was accompanied by similar iron-stress induced blue-shift of the main red Chl a absorption peak and a gradual decrease of the Phc/Chl ratio, although ΔpetE mutant was more sensitive when exposed to iron deficient conditions. Despite comparable iron stress induced phenotypic changes, the inactivation of petE gene expression was accompanied with a significant reduction of the growth rates compared to WT cells. To examine the photosynthetic electron fluxes in vivo, far-red light induced P700 redox state transients at 820nm of WT and ΔpetE mutant cells grown under iron sufficient and iron deficient conditions were compared. The extent of the absorbance change (ΔA(820)/A(820)) used for quantitative estimation of photooxidizable P700(+) indicated a 2-fold lower level of P700(+) in ΔpetE compared to WT cells under control conditions. This was accompanied by a 2-fold slower re-reduction rate of P700(+) in the ΔpetE indicating a lower capacity for cyclic electron flow around PSI in the cells lacking plastocyanin. Thermoluminescence (TL) measurements did not reveal significant differences in PSII photochemistry between control WT and ΔpetE cells. However, exposure to iron stress induced a 4.5 times lower level of P700(+), 2-fold faster re-reduction rate of P700(+) and a temperature shift of the TL peak corresponding to S(2)/S(3)Q(B)(-) charge recombination in WT cells. In contrast, the iron-stressed ΔpetE mutant exhibited only a 40% decrease of P700(+) and no significant temperature shift in S(2)/S(3)Q(B)(-) charge recombination. The role of mobile electron carriers in modulating the photosynthetic electron fluxes and physiological acclimation of cyanobacteria to low iron conditions is discussed. This article is part of a Special Issue entitled: Photosynthesis Research for Sustainability: from Natural to Artificial.


Subject(s)
Iron/metabolism , Photosystem I Protein Complex/physiology , Plastocyanin/physiology , Synechococcus/metabolism , Acclimatization , Electron Transport
10.
Biochim Biophys Acta ; 1817(8): 1374-9, 2012 Aug.
Article in English | MEDLINE | ID: mdl-22445720

ABSTRACT

Leaves of transgenic tobacco plants with decreased levels of fatty acid unsaturation in phosphatidylglycerol (PG) exhibited a slightly lower level of the steady state oxidation of the photosystem I (PSI) reaction center P700 (P700(+)) than wild-type plants. The PSI photochemistry of wild-type plants was only marginally affected by high light treatments. Surprisingly, all plants of transgenic lines exhibited much higher susceptibility to photoinhibition of PSI than wild-type plants. This was accompanied by a 2.5-fold faster re-reduction rate of P700(+) in the dark, indicating a higher capacity for cyclic electron flow around PSI in high light treated transgenic leaves. This was associated with a much higher intersystem electron pool size suggesting over-reduction of the PQ pool in tobacco transgenic lines with altered PG unsaturation compared to wild-type plants. The physiological role of PG unsaturation in PSI down-regulation and modulation of the capacity of PSI-dependent cyclic electron flows and distribution of excitation light energy in tobacco plants under photoinhibitory conditions at low temperatures is discussed. This article is part of a Special Issue entitled: Photosynthesis Research for Sustainability: from Natural to Artificial.


Subject(s)
Fatty Acids, Unsaturated/metabolism , Nicotiana/metabolism , Phosphatidylglycerols/metabolism , Photosystem I Protein Complex/metabolism , Cold Temperature , Light , Plant Leaves/metabolism , Plants, Genetically Modified/metabolism
11.
Klin Med (Mosk) ; 86(6): 62-6, 2008.
Article in Russian | MEDLINE | ID: mdl-18720715

ABSTRACT

With the aim of optimization of therapy of hepatic cirrhosis with manifestations of system encephalopathy 45 patients were examined. The patients were divided into 2 groups: control group (20 patients who received traditional therapy) and observing group (25 patients who in addition to traditional therapy received cryoapheresis). Clinical symptoms, results of neuropsychological and paraclinical examination, and indices of dynamic hepatobiliscintigraphy against the background of various methods of therapy were studied. It was established that with the use of pathogenetic therapy of hepatic encephalopathy--cryoapheresis--processes of hepatic encephalopathy progressing significantly decelerated, which made possible to approach to the choice of therapy individually, and, thereby, to optimize treatment.


Subject(s)
Blood Component Removal/methods , Hepatic Encephalopathy/therapy , Liver Cirrhosis/therapy , Adult , Female , Follow-Up Studies , Hepatic Encephalopathy/etiology , Humans , Liver Cirrhosis/complications , Male , Middle Aged , Treatment Outcome
12.
Physiol Mol Biol Plants ; 14(3): 205-15, 2008 Jul.
Article in English | MEDLINE | ID: mdl-23572888

ABSTRACT

Analysis of the partitioning of absorbed light energy within PSII into fractions utilized by PSII photochemistry (ØPSII), thermally dissipated via ΔpH-and zeaxanthin-dependent energy quenching (ØNPQ) and constitutive non-photochemical energy losses (ØNO) was performed in wild type and F2 mutant of barley. The estimated energy partitioning of absorbed light to various pathways indicated that the fraction of ØPSII was slightly higher, while the proportion of thermally dissipated energy through ØNPQ was 38% lower in F2 mutant than in WT. In contrast, ØNO, i.e. the fraction of absorbed light energy dissipated by additional quenching mechanism(s) was 34% higher in F2 mutant. The increased proportion of ØNO correlated with narrowing the temperature gap (ΔT M) between S2/3QB- and S2QA- charge recombinations in F2 mutant as revealed by thermoluminescence measurements. We suggest that this would result in increased probability for an alternative non-radiative P680+QA- radical pair recombination pathway for energy dissipation within the reaction centre of PSII (reaction center quenching) and that this additional quenching mechanism might play an important role in photoprotection when the capacity for the primary, zeaxanthin-dependent non-photochemical quenching (ØNPQ) and state transitions pathways are restricted in the absence of LHCII polypeptides in F2 mutant.

13.
Sud Med Ekspert ; 50(3): 28-30, 2007.
Article in Russian | MEDLINE | ID: mdl-17598446

ABSTRACT

The method of clonidine identification in blood and urine is described. It is based on liquid-liquid extraction and purification with toluol, subsequent derivation with pentafluobenzoylchloride and test on gas chromatograph with a detector of electron capture. The method is proposed for expert examinations.


Subject(s)
Antihypertensive Agents/blood , Antihypertensive Agents/urine , Chromatography, Gas/methods , Clonidine/blood , Clonidine/urine , Forensic Toxicology , Calibration , Humans , Sensitivity and Specificity , Solvents/chemistry
14.
FEBS Lett ; 580(11): 2797-802, 2006 May 15.
Article in English | MEDLINE | ID: mdl-16674953

ABSTRACT

Acclimation of wild type and the chlorina F2 mutant of barley to either high light or low temperature results in a 2- to 3-fold increase in non-photochemical quenching which occurred independently of either energy-dependent quenching (qE), xanthophyll cycle-mediated antenna quenching or state transitions. Results of in vivo thermoluminescence measurements used to address this conundrum indicated that excitation pressure regulates the temperature gap for S(2)Q(B)(-) and S(2)Q(A)(-) charge recombinations within photosystem II reaction centers. This is discussed in terms of photoprotection through non-radiative charge recombination.


Subject(s)
Acclimatization/physiology , Hordeum/metabolism , Hordeum/radiation effects , Light , Photosystem II Protein Complex/metabolism , Temperature , Hordeum/genetics , Hordeum/growth & development , Photosynthesis/radiation effects , Photosystem II Protein Complex/genetics
16.
Planta ; 215(3): 457-65, 2002 Jul.
Article in English | MEDLINE | ID: mdl-12111228

ABSTRACT

The potential of photosynthesis to recover from winter stress was studied by following the thermoluminescence (TL) and chlorophyll fluorescence changes of winter pine needles during the exposure to room temperature (20 degrees C) and an irradiance of 100 micromol m(-2) s(-1). TL measurements of photosystem II (PSII) revealed that the S(2)Q(B)(-) charge recombinations (the B-band) were shifted to lower temperatures in winter pine needles, while the S(2)Q(A)(-) recombinations (the Q-band) remained close to 0 degrees C. This was accompanied by a drastically reduced (65%) PSII photochemical efficiency measured as F(v)/ F(m,) and a 20-fold faster rate of the fluorescence transient from F(o) to F(m) as compared to summer pine. A strong positive correlation between the increase in the photochemical efficiency of PSII and the increase in the relative contribution of the B-band was found during the time course of the recovery process. The seasonal dynamics of TL in Scots pine needles studied under field conditions revealed that between November and April, the contribution of the Q- and B-bands to the overall TL emission was very low (less than 5%). During spring, the relative contribution of the Q- and B-bands, corresponding to charge recombination events between the acceptor and donor sides of PSII, rapidly increased, reaching maximal values in late July. A sharp decline of the B-band was observed in late summer, followed by a gradual decrease, reaching minimal values in November. Possible mechanisms of the seasonally induced changes in the redox properties of S(2)/S(3)Q(B)(-) recombinations are discussed. It is proposed that the lowered redox potential of Q(B) in winter needles increases the population of Q(A)(-), thus enhancing the probability for non-radiative P680(+)Q(A)(-) recombination. This is suggested to enhance the radiationless dissipation of excess light within the PSII reaction center during cold acclimation and during cold winter periods.


Subject(s)
Photosynthesis , Pinus/physiology , Seasons , Acclimatization , Chlorophyll/metabolism , Diuron/pharmacology , Electron Transport , Kinetics , Light-Harvesting Protein Complexes , Luminescent Measurements , Photosynthetic Reaction Center Complex Proteins/drug effects , Photosynthetic Reaction Center Complex Proteins/metabolism , Photosystem II Protein Complex , Pinus sylvestris , Temperature
17.
Bull Exp Biol Med ; 133(4): 404-7, 2002 Apr.
Article in English | MEDLINE | ID: mdl-12124659

ABSTRACT

The protective effect of verapamil against acute ototoxic sensorineural damage produced by intraperitoneal injections of kanamycin (50 mg/kg daily for 14 day) was studied on rats. The functional (otoacoustic emission), histological, and physiological methods proved the protective effect of daily injections of calcium channel blocker verapamil (2 mg/kg) on the state of hair cells of the organ of Corti.


Subject(s)
Calcium Channel Blockers/pharmacology , Deafness/chemically induced , Kanamycin/toxicity , Organ of Corti/drug effects , Verapamil/pharmacology , Animals , Male , Organ of Corti/cytology , Organ of Corti/physiology , Rats
18.
Planta ; 213(4): 575-85, 2001 Aug.
Article in English | MEDLINE | ID: mdl-11556790

ABSTRACT

As shown before [C. Ottander et al. (1995) Planta 197:176-183], there is a severe inhibition of the photosystem (PS) II photochemical efficiency of Scots pine (Pinus sylvestris L.) during the winter. In contrast, the in vivo PSI photochemistry is less inhibited during winter as shown by in vivo measurements of deltaA820/A820 (P700+). There was also an enhanced cyclic electron transfer around PSI in winter-stressed needles as indicated by 4-fold faster reduction kinetics of P700+. The differential functional stability of PSII and PSI was accompanied by a 3.7-fold higher intersystem electron pool size, and a 5-fold increase in the stromal electron pool available for P700+ reduction. There was also a strong reduction of the QB band in the thermoluminescence glow curve and markedly slower Q-A re-oxidation in needles of winter pine, indicating an inhibition of electron transfer between QA and QB. The data presented indicate that the plastoquinone pool is largely reduced in winter pine, and that this reduced state is likely to be of metabolic rather than photochemical origin. The retention of PSI photochemistry, and the suggested metabolic reduction of the plastoquinone pool in winter stressed needles of Scots pine are discussed in terms of the need for enhanced photoprotection of the needles during the winter and the role of metabolically supplied energy for the recovery of photosynthesis from winter stress in evergreens.


Subject(s)
Adaptation, Physiological , Photosynthesis/physiology , Photosynthetic Reaction Center Complex Proteins/metabolism , Pinus/physiology , Adenosine Diphosphate/metabolism , Adenosine Triphosphate/metabolism , Chlorophyll/metabolism , Electron Transport , Light-Harvesting Protein Complexes , Oxidation-Reduction , Photochemistry , Pinus sylvestris , Plant Leaves/physiology , Plastoquinone/metabolism , Seasons , Temperature
19.
Planta ; 214(2): 295-303, 2001 Dec.
Article in English | MEDLINE | ID: mdl-11800395

ABSTRACT

The effects of short-term cold stress and long-term cold acclimation on the light reactions of photosynthesis were examined in vivo to assess their contributions to photosynthetic acclimation to low temperature in Arabidopsis thaliana (L.) Heynh.. All photosynthetic measurements were made at the temperature of exposure: 23 degrees C for non-acclimated plants and 5 degrees C for cold-stressed and cold-acclimated plants. Three-day cold-stress treatments at 5 degrees C inhibited light-saturated rates of CO2 assimilation and O2 evolution by approximately 75%. The 3-day exposure to 5 degrees C also increased the proportion of reduced QA by 50%, decreased the yield of PSII electron transport by 65% and decreased PSI activity by 31%. In contrast, long-term cold acclimation resulted in a strong but incomplete recovery of light-saturated photosynthesis at 5 degrees C. The rates of light-saturated CO2 and O2 gas exchange and the in vivo yield of PSII activity under light-saturating conditions were only 35-40% lower, and the relative redox state of QA only 20% lower, at 5 degrees C after cold acclimation than in controls at 23 degrees C. PSI activity showed full recovery during long-term cold acclimation. Neither short-term cold stress nor long-term cold acclimation of Arabidopsis was associated with a limitation in ATP, and both treatments resulted in an increase in the ATP/NADPH ratio. This increase in ATP/NADPH was associated with an inhibition of PSI cyclic electron transport but there was no apparent change in the Mehler reaction activity in either cold-stressed or cold-acclimated leaves. Cold acclimation also resulted in an increase in the reduction state of the stroma, as indicated by an increased total activity and activation state of NADP-dependent malate dehydrogenase, and increased light-dependent activities of the major regulatory enzymes of the oxidative pentose-phosphate pathway. We suggest that the photosynthetic capacity during cold stress as well as cold acclimation is altered by limitations at the level of consumption of reducing power in carbon metabolism.


Subject(s)
Acclimatization/physiology , Arabidopsis/physiology , Chloroplasts/physiology , Photosynthesis/physiology , Adenosine Triphosphate/metabolism , Carbon/metabolism , Carbon Dioxide/metabolism , Carbon Dioxide/radiation effects , Chlorophyll/metabolism , Chlorophyll A , Cold Temperature , Fluorescence , Light , Light-Harvesting Protein Complexes , NAD/metabolism , NADP/metabolism , Oxidation-Reduction , Oxygen Consumption/physiology , Oxygen Consumption/radiation effects , Photosynthesis/radiation effects , Photosynthetic Reaction Center Complex Proteins/metabolism , Photosynthetic Reaction Center Complex Proteins/radiation effects , Plant Leaves/physiology , Starch/metabolism , Sucrose/metabolism
20.
J Photochem Photobiol B ; 57(1): 33-40, 2000 Aug.
Article in English | MEDLINE | ID: mdl-11100835

ABSTRACT

Electric light scattering measurements demonstrate a strong decline in the permanent electric dipole moment and electric polarizability of both thylakoid membranes and photosystem II-enriched particles of the Chlorina f2 mutant which has severely reduced levels of light-harvesting chlorophyll a/b-binding proteins compared to the wild type barley chloroplasts. The shift in the electric polarizability relaxation to higher frequencies in thylakoids and photosystem II particles from Chlorina f2 reflects higher mobility of the interfacial charges of the mutant than that of the wild type membranes. The experimental data strongly suggest that the major light-harvesting complex of photosystem II directly contribute to the electric properties of thylakoid membranes.


Subject(s)
Chlorophyll/physiology , Hordeum/physiology , Photosynthetic Reaction Center Complex Proteins/metabolism , Thylakoids/physiology , Chlorophyll/genetics , Electricity , Hordeum/genetics , Hordeum/radiation effects , Kinetics , Light , Light-Harvesting Protein Complexes , Protein Kinases/metabolism , Scattering, Radiation , Thylakoids/ultrastructure
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