Molecular phylogeny of Neotropical bioluminescent beetles (Coleoptera: Elateroidea) in southern and central Brazil

Bioluminescence in beetles is found mainly in the Elateroidea superfamily (Elateridae, Lampyridae and Phengodidae). The Neotropical region accounts for the richest diversity of bioluminescent species in the world with about 500 described species, most occurring in the Amazon, Atlantic rainforest and Cerrado (savanna) ecosystems in Brazil. The origin and evolution of bioluminescence, as well as the taxonomic status of several Neotropical taxa in these families remains unclear. In order to contribute to a better understanding of the phylogeny and evolution of bioluminescent Elateroidea we sequenced and analyzed sequences of mitochondrial NADH2 and the nuclear 28S genes and of the cloned luciferase sequences of Brazilian species belonging to the following genera: (Lampyridae) Macrolampis, Photuris, Amydetes, Bicellonycha, Aspisoma, Lucidota, Cratomorphus; (Elateridae) Conoderus, Pyrophorus, Hapsodrilus, Pyrearinus, Fulgeochlizus; and (Phengodidae) Pseudophengodes, Phrixothrix, Euryopa and Brasilocerus. Our study supports a closer phylogenetic relationship between Elateridae and Phengodidae as other molecular studies, in contrast with previous morphologic and molecular studies that clustered Lampyridae/Phengodidae. Molecular data also supported division of the Phengodinae subfamily into the tribes Phengodini and Mastinocerini. The position of the genus Amydetes supports the status of the Amydetinae as a subfamily. The genus Euryopa is included in the Mastinocerini tribe within the Phengodinae/Phengodidae. Copyright © 2013 John Wiley & Sons, Ltd.     

Insights into the structural nature of the transition state in the Kir channel gating pathway

In a previous study we identified an extensive gating network within the inwardly rectifying Kir1.1 (ROMK) channel by combining systematic scanning mutagenesis and functional analysis with structural models of the channel in the closed, pre-open and open states. This extensive network appeared to stabilize the open and pre-open states, but the network fragmented upon channel closure. In this study we have analyzed the gating kinetics of different mutations within key parts of this gating network. These results suggest that the structure of the transition state (TS), which connects the pre-open and closed states of the channel, more closely resembles the structure of the pre-open state. Furthermore, the G-loop, which occurs at the center of this extensive gating network, appears to become unstructured in the TS because mutations within this region have a ‘catalytic’ effect upon the channel gating kinetics.     

Ultrasonographic study of blood flow in the renal arteries of patients with arterial hypertension

Vascular duplex ultrasound duplex with simultaneous ECG registration was made to estimate the quantitative and time parameters of blood flow in the renal arteries with grade 1-2 arterial hypertension. There were increases in vascular resistance indices and acceleration phase index and a reduction in systolic phase index. There were correlations of the time parameters of blood flow in the renal arteries with age and lipidogram values.     

Epileptogenic activity of tripeptide corticotropin-releasing factor fragment (CRF(4-6))

The effects of centrally administered tripeptide fragment CRF(4-6) of corticotropin-releasing factor on convulsive activity in outbred albino rats were investigated. The peptide CRF(4-6) (icv; 6, 30, 150 nmol/head) causes dose-dependent increase in total EEG power in 1-40 Hz frequency range as a reflection of tripeptide-induced various epileptiform EEG signs such as single peaks and spike trains without external convulsion. Higher doses of CRF(4-6) (icv; 150, 225, 300 nmol per animal) induce tonicoclonic seizures. Switching to convulsive activity occurs at CRF(4-6) dose of 150 nmol per animal: injection of this dose leads only to EEG paroxysmal activity under habitual conditions and induces pathological locomotor activation under stressing conditions. Thus, CRF(4-6) similarly to full-length corticotropin-releasing factor induces epileptiform activity in rats.     

Ghrelin immunohistochemistry of gastric adenocarcinoma and mucoepidermoid carcinoma of salivary gland

Ghrelin (G-HH) synthesized in several tissues including salivary and stomach glands stimulates appetite in humans by modulating neuropeptide Y neurons in the hypothalamic arcuate nucleus. Loss of appetite is one of the most important symptoms of stomach cancer. We conducted a study using immunohistochemistry to determine whether salivary glands and stomach cancer tissues produce ghrelin. We determined that negative ghrelin immunohistochemistry discriminates tumors from normal tissues and may therefore further our understanding of the clinically important problem of reduced food intake and anorexia in cancer patients. Radioimmunoassay analyses confirmed that cancer cells do not produce a G-HH peptide, whereas normal cells yield this peptide.     

The Effect of Interval Hypoxic Hypoxia on the Vascular Endothelial Growth Factor and Basic Fibroblast Growth Factor Concentrations in the Peripheral Blood

We studied the effect of a 14-day course of interval hypoxic hypoxia (IHH) on the concentration in the blood of healthy subjects of the vascular endothelial growth factor (vEGF) and the basic fibroblast growth factor (bFGF), which regulate endothelial cell proliferation and angiogenesis. The IHH course was carried out using a BIO-NOVA 204 plant for modeling hypoxic conditions. IHH resulted in a twofold increase in vEGF 24 h after its application; this was followed by a decrease in vEGF to the initial level 48 h after IHH, a subsequent increase by 40% 72 h after IHH, and normalization to the initial level by day 14. The concentration of bFGF increased by 21% 24 h after IHH and gradually decreased to the initial level by day 14. During the initial 24–72 h, changes in the concentration of both factors positively correlated with the dynamics of oxidative stress markers, such as total prooxidative activity and plasma concentration of thiobarbituric acid–reactive species. It is assumed that IHH increases the vEGF content owing to induction of its biosynthesis by reactive oxygen species. Therefore, it is promising to examine the effect of IHH on the morphofunctional parameters of endothelium.     

Precipitated,Coprecipitated, and Carbon–Mineral Sorbents for Isolation of Exracellular Catalase from Penicillium piceum F-648

The abilities of various sorbents to adsorb catalase (CAT; EC 1.11.1.6) from filtered culture liquid (FCL) of the fungus Penicillium piceum F-648 were compared. Potassium phosphate, hydroxyapatite (HAP), and coprecipitated sorbents containing calcium phosphate and magnesium hydroxide adsorbed extracellular CAT more efficiently than aluminum oxide, aluminum phosphate, or quartz sand. The enzyme was isolated from FCL of Penicillium piceum with the use of HAP and a binary coprecipitated sorbent, Ca₃(PO₄)₂ + Mg(OH)₂, 1 : 1 (CM). The CAT(CM) sample contained the least amount of protein admixture. Its spectra had absorption maximums at 279.6, 406.8 (Soret band), 540, 585, 636, and 703 nm and negative molar ellipticity minimums at 207 and 210–214 nm. The kinetic indices of the samples (K _M, V _max : K _M, and specific activity) were intricately dependent on the protein concentration in the reaction mixture. In dilute solutions, the K _M and specific activities of CAT(CM) and CAT(HAP) equaled 667 and 137 mM; 300.9 × 10⁴ and 30.0 × 10⁴ U/mg protein, respectively. The effective velocity constants of inactivation of CAT(HAP), CAT(CM), and FCL in the reaction of H₂O₂ decomposition increased dramatically after the dilution of samples. In the infinitely dilute solution, they were 4.30 × 10^–2, 6.46 × 10^–2, and 1.12 × 10^–2 s^–1, respectively.     

Specific and non-specific mouse protection induced by different chemotypes of the Pseudomonas aeruginosa lipopolysaccharides

Abstract Lipopolysaccharides (LPS) of Pseudomonas aeruginosa were studied by the mouse active, cross-protection test. The primary structure of O-specific polysaccharides (O-repeating units) of different chemotypes was determined and their cross-protective activity demonstrated. Low doses of LPS (0.1–1 μg) stimulated chemotype-specific protection against P. aeruginosa in mice. This immunity was associated with the primary structure of the LPS and it lasted for 14 days after the first or second immunization. High doses of LPS (10–100 μg) induced cross-protection against P. aeruginosa in mice. The cross-protective capacity was caused evidently by the secondary structure or conformation of LPS molecule, i.e. by the common conformational protective determinant. This cross-protection lasted for only 5 days after the first or second immunization.