We studied the effect of reduced tryptophan hydroxylase (TPH) activity and short daylight exposure on the behavior and the 5-HT system of the brain in
D. rerio
. Male and female
D. rerio
were exposed ...for 30 days to standard (12:12 h light:dark) and short (4:20 h light:dark) photoperiods in the presence or absence of TPH inhibitor (
p
-chlorophenylalanine, pCPA, 5 mg/liter). On day 31, the fish behavior in the “novel tank diving” test, their sex and body weight were determined, and the levels of pCPA, 5-HT, and its metabolite 5-HIAA were measured by HPLC; the levels of the key genes encoding metabolism enzymes (
Tph1a
,
Tph1b
,
Tph2
, and
Mao
) and receptors of 5-HT (
Htr1aa
,
Htr2aa
) were assessed by real-time PCR with reverse transcription. The short daylight exposure caused masculinization of females, reduced body weight, and motor activity in the “novel tank diving” test, but did not affect the 5-HT system of the brain. Long-term pCPA treatment had no effect on sex and body weight, significantly reduced the 5-HIAA level, but increased
Tph1a
and
Tph2
gene expression in the brain. No effects of the interaction of short daylight and pCPA exposure on the sex, body weight, behavior, and 5-HT system of the brain were found. Thus, a moderate decrease in TPH activity cannot potentiate the negative effects of short daylight exposure on the sex, body weight, behavior, and 5-HT system of
D. rerio
.
The role of microcirculatory disorders is progressively being accepted in the pathogenesis of cardiovascular diseases.
The purpose of current study is to assess whether we can consider skin ...microcirculation disorders as a biomarker of cardiovascular events.
Group 1 consisted of healthy volunteers (n = 31); group 2 (n = 42) consisted of patients with diseases that increase the risk of cardiovascular events; group 3 (n = 39) included patients with the history of cardiovascular events. Skin microcirculation measurement was performed using laser Doppler flowmetry during the heating test.
LDF parameters reflecting the rapid response of microcirculation to heating ("Slope 120 s" and "Slope 180 s") significantly differed in three groups (p < 0.05). A decrease in the "Slope 180 s" parameter less than 0.5 PU/s is associated with cardiovascular events (sensitivity 69.2%, specificity 66.7%; the area under the ROC curve, 0.667; 95% confidence interval CI, 0.545-0.788, p = 0.01). Multivariable logistic regression analysis revealed that "Slope 180 s≤0.5 PU/s" was significantly related to cardiovascular events (adjusted odds ratio = 3.9, p = 0.019, CI 95% 1.2-12).
Reduced reactivity of the skin microcirculation may be useful as a biomarker of severe damage to the cardiovascular system and is promising as a risk factor for cardiovascular events.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Aluminium alloys containing small additions of scandium exhibit unique operating properties. Alloying material with scandium significantly improves product weldability, reduces the tendency towards ...hot cracks and improves welded joint mechanical properties. The aim of this work is to increase the scandium extraction into a master alloy by preliminary transformation of scandium oxide into fluoride and introduction into the composition of an aluminium powder alloying additive. Results are provided of laboratory experiments for preparation of aluminium-scandium master alloy by aluminothermic reduction of scandium fluoride using sodium fluoride and aluminium powder within the alloy composition. Scandium fluoride is prepared by treating scandium oxide with 40% hydrofluoric acid. The overall extraction of scandium from oxide into fluoride and from fluoride to the aluminium-scandium master alloy is 88.5% with an average scandium concentration in the master alloy of 1.90 wt.%. The microstructure of the master alloy obtained is represented by scandium aluminide Al.sub.3Sc crystals with a size from 10 to 25 mum uniformly distributed within the master alloy. An additional reserve for increasing the extraction of scandium into the master alloy and reducing its cost is processing of slags formed in the preparation of the ligature. The use of an aluminium powder with high specific surface area in the composition of the alloying additive increases scandium extraction into the master alloy due to better contact of the reacting phases. The resultant Al-Sc master alloy has uniform distribution of Al.sub.3Sc particles within the volume of the metal.
Parkinson's disease (PD) is the most common age-related movement disorder characterized by the progressive loss of nigrostriatal dopaminergic neurons. To date, PD treatment strategies are mostly ...based on dopamine replacement medicines, which can alleviate motor symptoms but do not slow down the progression of neurodegeneration. Thus, there is a need for disease-modifying PD therapies. The aim of this work was to evaluate the neuroprotective effects of the novel compound PA96 on dopamine neurons in vivo and in vitro, assess its ability to alleviate motor deficits in MPTP- and haloperidol-based PD models, as well as PK profile and BBB penetration. PA96 was synthesized from (1
,2
,6
)-3-methyl-6-(prop-1-en-2-yl) cyclohex-3-ene-1,2-diol (Prottremin) using the original three-step stereoselective procedure. We found that PA96: (1) supported the survival of cultured näive dopamine neurons; (2) supported the survival of MPP
-challenged dopamine neurons in vitro and in vivo; (3) had chemically appropriate properties (synthesis, solubility, etc.); (4) alleviated motor deficits in MPTP- and haloperidol-based models of PD; (5) penetrated the blood-brain barrier in vivo; and (6) was eliminated from the bloodstream relative rapidly. In conclusion, the present article demonstrates the identification of PA96 as a lead compound for the future development of this compound into a clinically used drug.
The review discusses the potential relationship between hypoxia resistance and longevity, the influence of carbon dioxide on the mechanisms of aging of the mammalian organism, and intermittent ...hypercapnic–hypoxic effects on the signaling pathways of aging mechanisms. In the article, we focused on the potential mechanisms of the gero-protective efficacy of carbon dioxide when combined with hypoxia. The review summarizes the possible influence of intermittent hypoxia and hypercapnia on aging processes in the nervous system. We considered the perspective variants of the application of hypercapnic–hypoxic influences for achieving active longevity and the prospects for the possibilities of developing hypercapnic–hypoxic training methods.
In this study, we developed iron oxide nanoparticles stabilised with oleic acid/sodium oleate that could exert therapeutic effects for curing tumours via magnetic hyperthermia. A suspension of iron ...oxide nanoparticles was produced and characterised. The toxicity of the synthesised composition was examined in vivo and found to be negligible. Histological examination showed a low local irritant effect and no effect on the morphology of the internal organs. The efficiency of magnetic hyperthermia for the treatment of transplanted Walker 256 carcinoma was evaluated. The tumour was infiltrated with the synthesised particles and then treated with an alternating magnetic field. The survival rate was 85% in the studied therapy group of seven animals, while in the control group (without treatment), all animals died. The physicochemical and pharmaceutical properties of the synthesised fluid and the therapeutic results, as seen in the in vivo experiments, provide insights into therapeutic hyperthermia using injected magnetite nanoparticles.
A novel neutral tetranitrosyl iron complex {Fe(H
2
O)
4
2+
FeR
2
(NO)
2
2
2−
}·4H
2
O (
1
) with R = 5-(3-pyridyl)-4
H
-1,2,4-triazole-3-thiolyls (C
7
H
5
N
4
S), which is a supramolecular ...ensemble, has been synthesized and studied. As follows from X-ray diffraction analysis, this is an octahedral Fe
2+
complex (Lewis acid) with two monoanionic dinitrosyl groups FeR
2
(NO)
2
−
(Lewis base) and 4 water molecules as the ligands. As follows from Mössbauer spectra, the coordinating Fe
2+
ion is in a low-spin state
S
= 0, and the dinitrosyl Fe
+
ion is in a low-spin state
S
= 1/2. According to the data of EPR spectroscopy, mass-spectrometry and amperometry, complex
1
in solution forms dinitrosyl particles of Fe(C
7
H
6
N
4
S-H)
2
(NO)
2
−
composition, which are responsible for NO generation. In addition, complex
1
was shown to be a 5-6 times more efficient phosphodiesterase (PDE) inhibitor at 5 × 10
−5
M and 10
−4
M concentrations than its thioligand. Probable binding sites of the FeR
2
(NO)
2
−
ligand for the bovine PDE1B model have been determined by molecular docking and quantum-chemical calculations.
A novel neutral tetranitrosyl iron complex {Fe(H
2
O)
4
2+
FeR
2
(NO)
2
2
2−
}·4H
2
O (
1
) with R = 5-(3-pyridyl)-4
H
-1,2,4-triazole-3-thiolyls (C
7
H
5
N
4
S), which is a supramolecular ensemble, has been synthesized and studied.
The enzyme tryptophan hydroxylase 2 (TPH2) catalyzes the hydroxylation of L-tryptophan to L-5-hydroxytryptophan (5-HTP), the first and the key step in 5-HT synthesis in the mammalian brain. Mutations ...in the human
Tph2
gene reducing enzyme activity increase the risk of psychopathology. Pharmacological chaperones are small molecules that can specifically bind to mutant protein molecules, restore their disturbed 3D structure to the native state, and increase their stability and functional activity. The chaperone activity of (R)-2-amino-6-(1R,2S)-1,2-dihydroxypropyl)-5,6,7,8-tetrahydropterin-4(3H)-one (BH
4
) is expressed by increasing the
in vitro
thermal stability of mutant tyrosine hydroxylase and phenylalanine hydroxylase molecules which are similar to TPH2 in their structure and characteristics. The
P447R
substitution in the mouse TPH2 molecule results in a 2-fold decrease in enzyme activity in their brains. We studied the effect of this mutation on the TPH2 thermal stability, as well as on the ability of BH
4
and its 8 structural analogues to increase the thermal stability of the mutant TPH2 from midbrain extracts of BALB/C mice. Temperature stability was studied by the decrease in enzyme activity during its heating for 2 min at increasing temperatures and was evaluated by the T
50
value that is the temperature at which the enzyme activity decreased by half. For the mutant TPH2, the T
50
value was decreased compared to the wild type enzyme. BH
4
and its closest structural analogue, 6-methyl-5,6,7,8-tetrahydropterin, increased the T
50
value,
i.e.
, exhibited chaperone activity. Other close BH
4
analogs, 6,7-dimethyl-5,6,7,8-tetrahydropterin and folic acid, were not effective. It can be assumed that BH
4
can be effective in the treatment of mental disorders caused by mutations in the
Tph2
gene.
The objects of the study were recombinant clones of Komagataella phaffii K51 carrying the heterologous proteinase K (PK-w) gene from Tritirachium album integrated into their genome as well as samples ...of recombinant proteinase K isolated from these clones. The aims of this work were i) to determine whether it is possible to create recombinant K. phaffii K51 clones overexpressing functionally active proteinase K from T. album and ii) to analyze the enzymatic activity of the resulting recombinant enzyme. The following methods were used: computational analysis of primary structure of the proteinase K gene, molecular biological methods (PCR, electrophoresis of DNA in an agarose gel, electrophoresis of proteins in an SDS polyacrylamide gel under denaturing conditions, spectrophotometry, and quantitative assays of protease activity), and genetic engineering techniques (cloning and selection of genes in bacterial cells Escherichia coli TOP10 and in the methylotrophic yeast K. phaffii K51). The gene encoding natural proteinase K (PK-w) was designed and optimized for expression in K. phaffii K51. The proteinase K gene was synthesized and cloned within the plasmid pPICZα-A vector in E. coli TOP10 cells. The proteinase K gene was inserted into pPICZα-A in such a way that - at a subsequent stage of transfection into yeast cells - it was efficiently expressed under the control of the promoter and terminator of the AOX1 gene, and the product of the exogenous gene contained the signal peptide of the Saccharomyces cerevisiae a-factor to ensure the protein's secretion into the culture medium. The resultant recombinant plasmid (pPICZα-A/PK-w) was transfected into K. phaffii K51 cells. A recombinant K. phaffii K51 clone was obtained that carried the synthetic proteinase K gene and ensured its effective expression and secretion into the culture medium. An approximate productivity of the yeast recombinant clones for recombinant proteinase K was 25 μg/ mL after 4 days of cultivation. The resulting recombinant protease has a high specific proteolytic activity: ~5000 U/mg.
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