Novel pH-Sensitive Microbial Rhodopsin from Sphingomonas paucimobilis.

This work provides the first characteristics of the rhodopsin SpaR from Sphingomonas paucimobilis, aerobic bacteria associated with opportunistic infections. The sequence analysis of SpaR has shown that this protein has unusual DTS motif which has never reported in rhodopsins from Proteobacteria. We report that SpaR operates as an outward proton pump at low pH; however, proton pumping is almost absent at neutral and alkaline pH. The photocycle of this rhodopsin in detergent micelles slows down with an increase in pH because of longer Schiff base reprotonation. Our results show that the novel microbial ion transporter SpaR of interest both as an object for basic research of membrane proteins and as a promising optogenetic tool.

[Erosive and ulcerative lesions of gastrointestinal tract in patients with burns]. / Erozivno-yazvennye porazheniya zheludochno-kishechnogo trakta pri ozhogovoi travme.

OBJECTIVE: To analyze the incidence of erosive and ulcerative lesions of gastrointestinal tract in patients with burns, including those complicated by gastrointestinal bleeding, depending on severity of injury, complications of burn disease and treatment features. MATERIAL AND METHODS: Medical records of 1833 patients were reviewed. We have retrospectively analyzed symptoms of disease and incidence of gastrointestinal bleeding depending on treatment strategy in patients with identified erosive and ulcerative lesions of gastrointestinal tract. RESULTS: Risk of gastrointestinal erosions and ulcers, including those complicated by gastrointestinal bleeding, correlates with area and depth of burn damage, especially in patients with thermo-inhalation injury and infectious complications of burn disease. Proton pump inhibitors intake in patients with burns of up to 50% of body surface area (BSA) and deep lesions up to 40% of BSA is followed by less incidence of gastrointestinal bleeding compared to H2-histamine receptor blockers. At the same time, severe burns of more than 50% of BSA ensure high risk of gastrointestinal bleeding regardless antisecretory therapy. CONCLUSION: Endoscopy upon admission is recommended in all patients with burns ≥30% of BSA or deep lesions ≥20% of BSA, as well as severe thermo-inhalation injury. This approach ensures timely diagnosis of gastrointestinal lesions and their adequate treatment.

[Latent dysphoria: an instrument of screening and diagnosis (preliminary results)]. / Latentnaia disforiia: instrument dlia skriningovoi diagnostiki (predvaritel'nye dannye).

AIM: Latent dysphoria is a kind of emotional disorder. Its key features are floating feeling of dissatisfaction and irritability accompanied with suppression of expression of these emotions. The article is devoted to the development of a screening diagnostic tool (checklist) to screen and evaluate patients with this emotional problem. MATERIAL AND METHODS: Three hundred and ninety-four neurologists (outpatient segment) were surveyed to assess the prevalence of an emotional disorder that met criteria of latent dysphoria suggested by the authors. To develop a diagnostic tool, expert judgement method, with the involvement of 19 experts in different medical fields (psychiatry, psychology, gastroenterology, neurology), was used. RESULTS AND CONCLUSION: The final checklist contained the most typical signs of this disorder according to the opinion of the experts. The procedure of evaluation of these signs was developed. However, the results should be considered as preliminary and clinical psychiatric validation of the tool is needed.

[The use of the parameters of chlorophyll a fluorescence induction for assessment of plant state under anthropogenic load].

The technique for recording of chlorophyll a fluorescence induction kinetics has been used for assessment of the physiological state of leaves of tillet (Tilia cordata), pendent white birch (Betula pendula), American arborvitae (Thuja occidentalis) in urban environments. Different sensitivity of plants to adverse growing conditions was observed. The most sensitive JIP test parameters such as PI(ABS), F(V)/F(0), F(V)/F(M), R(fd) are determined to be used as indicators of the physiological state of urban phytocenosis. Recommendations for the application of this technique in monitoring studies are given.

[The effect of phenols on the parameters of chlorophyll fluorescence and reaction of P700 in the green algae Scenedesmus quadricauda].

The effect of phenols, present in drains of the tsellyulozo-paper industry, on photosynthesis of the microalgae Scenedesmus quadricauda has been studied. The analysis of induction curves of the slowed-down fluorescence and light curves of non-photochemical quenching of chlorophyll fluorescence of microalgae Scenedesmus quadricauda is carried out. It was observed that energization of photosynthetic membranes was inhibited at low concentration of phenol and pyrocatechin (0.1 mM). At higher concentrations phenol and pyrocatechin inhibited electron transport in FSII and increased a share of QB not restoring centers. As a result of it the rate of P700 pigment regeneration slowed down. The results obtained indicate that parameters of induction curves of the fast and slowed-down fluorescence can be used for detecting phenol and pyrocatechin in the environment at early stages of toxic effects.

[Theoretical study of fluorescence of photosynthetic pigments at complex dependence of intensity of exciting light on time].

Now the methods using the radiance with complex dependence of light intensity on time are applied to research of photosynthesis by means of fluorescence, exciting photosynthetic pigments. One of these methods is applied in PAM-fluorometers--the commercial devices currently widely used to investigate a state of photosynthesizing systems. However, if excitation is performed in this way, the question, what components of fluorescence are registered at an output of such devices, remains to be open-ended. In this work an attempt to analyse this task has been made.

Decrease in juvenile hormone level as a result of genetic ablation of the corpus allatum cells affects the synthesis and metabolism of stress related hormones in Drosophila.

Previous studies have shown that juvenile hormone (JH) regulates dopamine (DA) and octopamine (OA) content in Drosophila, and we have shown the influence of an increase in JH level on DA and OA metabolism in young females of Drosophila virilis and Drosophila melanogaster. Here we investigate the effects of genetic ablation of a subset of cells in the Corpusallatum (CA, endocrine gland synthesizing JH) on the DA levels and activities of alkaline phosphatase (ALP), tyrosine hydroxylase (TH), DA-dependent arylalkylamine N-acetyltransferase (DAT) and tyrosine decarboxylase (TDC) in young D. melanogaster females under normal conditions and upon heat stress (38°Ð¡). We show that ablation of СА cells causes: (1) a decrease in ALP, TH and DAT activities, (2) an increase in DA level and (3) an increase in TDC activity in young females. The CA ablation was also found to modulate ALP, TH and TDC responses to heat stress. Mechanisms of regulation of DA and OA levels by JH in Drosophila females are discussed.

Dopamine down-regulates activity of alkaline phosphatase in Drosophila: the role of D2-like receptors.

The effect of a rise in dopamine (DA) level as a result of a mutation, stress or pharmacological treatment on the activity of the enzyme of its synthesis, alkaline phosphatase (ALP) in females of Drosophila virilis and Drosophila melanogaster has been studied. It has been found that regardless of its nature, a rise in DA level has a negative effect on ALP activity, which indicates that DA down-regulates activity of the enzyme. The effects of bromocriptine (an agonist of Drosophila dopamine 2-like receptor (DD2R)) on ALP activity have been studied. ALP activity was found to drop in response to bromocriptine in flies. Conversely ALP activity was increased in flies with reduced DD2R expression (i.e. Actin5C-Gal4>UAS-ds-DD2R RNA-interference flies) vs. corresponding controls (i.e. Actin5C-Gal4>w1118 flies). Bromocriptine treatment of RNAi flies rescues ALP activity to the level typical of Actin5C-Gal4>w1118 flies. A change in DD2R number or availability was found not to prevent the response of ALP to heat stress, but to change the intensity of its response to the stress exposure. The role of D2-like receptors in down-regulation of ALP activity by DA and in ALP response to stressor in Drosophila is discussed.

Role of ecdysone 20-monooxygenase in regulation of 20-hydroxyecdysone levels by juvenile hormone and biogenic amines in Drosophila.

The effects of increased levels of dopamine (feeding flies with dopamine precursor, L: -dihydroxyphenylalanine) and octopamine (feeding flies with octopamine) on ecdysone 20-monooxygenase activity in young (2 days old) wild type females (the strain wt) of Drosophila virilis have been studied. L: -dihydroxyphenylalanine and octopamine feeding increases ecdysone 20-monooxygenase activity by a factor of 1.6 and 1.7, respectively. Ecdysone 20-monooxygenase activity in the young (1 day old) octopamineless females of the strain Tbetah ( nM18 ), in females of the strain P845 (precursor of Tbetah ( nM18 ) strain) and in wild type females (Canton S) of Drosophila melanogaster have been measured. The absence of octopamine leads to a considerable decrease in the enzyme activity. We have also studied the effects of juvenile hormone application on ecdysone 20-monooxygenase activity in 2-day-old wt females of D. virilis and demonstrated that an increase in juvenile hormone titre leads to an increase in the enzyme activity. We discuss the supposition that ecdysone 20-monooxygenase occupies a key position in the regulation of 20-hydroxyecdysone titre under the conditions that lead to changes in juvenile hormone titre and biogenic amine levels.

Role of arylalkylamine N-acetyltransferase in regulation of biogenic amines levels by gonadotropins in Drosophila.

The effect of 20-hydroxyecdysone (20E) and the juvenile hormone (JH) on the activity of the arylalkylamine N-acetyltransferase (AANAT) was studied in young females of wild-type D. virilis and D. melanogaster. 20E feeding of the flies led to a decrease in AANAT activity in both species when dopamine (DA) was used as substrate, but did not affect the enzyme activity when octopamine (OA) was used as substrate. JH application increased AANAT activity with DA as substrate in both species, but did not change it with OA as substrate. AANAT activity was also measured in young females of a JH-deficient strain of D. melanogaster, apterous ( 56f ). A decrease in the enzyme activity was observed in the mutant females as compared to wild-type. Mechanisms of regulation of DA level by gonadotropins in Drosophila are discussed.