The relationship between the parameters of the early and late oscillations of human cortical evoked potentials and the rhythm of acoustic stimulation]

The amplitudes of all deflections of the slow auditory evoked potential (AEP) regularly decrease in alert subjects with the increase of stimulation rate. As compared with the late deflections (P2N2), the decrease of the amplitude of comparatively early deflections (N1P2) is more pronounced. It is a rather logarithmic, than a linear function of the interstimulus interval. The degree of amplitude diminution of slow AEPs due to a greater stimulation rate depends on the intensity of acoustic stimul: at greater sound intensities the decrease is more pronounced. The higher rates of stimulation produce, along with a decreased amplitude, a shorter peak latencies of all slow AEP deflections (except the peak of deflection P1). In narcotic (chloralhydrate) sleep higher rates of stimulation are not attended with any regular changes in the amplitude and peak latencies of the slow AEP.     

Independent denaturation of albumin and globulins in human serum

The independent melting of albumin, gamma-globulin, transferrin, and protease inhibitors in the composition of donor blood serum was studied by differential scanning microcalorimetry. It was found that the number of domains in gamma-globulin in donor blood serum and in diluted solutions is the same, whereas the number of domains of albumin in solution and in the composition of blood serum is three and two, respectively. In blood serum, the N-terminal domain melts by the "all-or-none" mechanism. Therefore, the decomposition of peaks of the denaturation curve was made under the assumption that the denaturation of blood serum proteins occurs by the "all-or-none" principle. It is assumed that comparing the calculated melting parameters (Td, delta Td, delta Hd, delta Cd) of domains of blood serum proteins of donor with the corresponding parameters of patients with oncological and nononcological diseases can be used as a basis for a more precise diagnostics of these diseases.     

Diet-induced obesity in rats leads to a decrease in sperm motility

Background  

Obesity is rapidly becoming a worldwide epidemic that affects children and adults. Some studies have shown a relationship between obesity and infertility, but until now it remains controversial. Thus, the aim of the present study was to investigate the effect of high-fat diet-induced obesity on male reproductive parameters.     

Microcalorimetric investigation of DNA, poly(dA)poly(dT) and poly[d(A-C)]poly[d(G-T)] melting in the presence of water soluble (meso tetra (4 N oxyethylpyridyl) porphyrin) and its Zn complex

Thermodynamic parameters of melting process (DeltaHm, Tm, DeltaTm) of calf thymus DNA, poly(dA)poly(dT) and poly(d(A-C)).poly(d(G-T)) were determined in the presence of various concentrations of TOEPyP(4) and its Zn complex. The investigated porphyrins caused serious stabilization of calf thymus DNA and poly poly(dA)poly(dT), but not poly(d(A-C))poly(d(G-T)). It was shown that TOEpyp(4) revealed GC specificity, it increased Tm of satellite fraction by 24 degrees C, but ZnTOEpyp(4), on the contrary, predominantly bound with AT-rich sites and increased DNA main stage Tm by 18 degrees C, and Tm of poly(dA)poly(dT) increased by 40 degrees C, in comparison with the same polymers without porphyrin. ZnTOEpyp(4) binds with DNA and poly(dA)poly(dT) in two modes--strong and weak ones. In the range of r from 0.005 to 0.08 both modes were fulfilled, and in the range of r from 0.165 to 0.25 only one mode--strong binding--took place. The weak binding is characterized with shifting of Tm by some grades, and for the strong binding Tm shifts by approximately 30-40 degrees C. Invariability of DeltaHm of DNA and poly(dA)poly(dT), and sharp increase of Tm in the range of r from 0.08 to 0.25 for thymus DNA and 0.01-0.2 for poly(dA)poly(dT) we interpret as entropic character of these complexes melting. It was suggested that this entropic character of melting is connected with forcing out of H2O molecules from AT sites by ZnTOEpyp(4) and with formation of outside stacking at the sites of binding. Four-fold decrease of calf thymus DNA melting range width DeltaTm caused by increase of added ZnTOEpyp(4) concentration is explained by rapprochement of AT and GC pairs thermal stability, and it is in agreement with a well-known dependence, according to which DeltaT approximately TGC-TAT for DNA obtained from higher organisms (L. V. Berestetskaya, M. D. Frank-Kamenetskii, and Yu. S. Lazurkin. Biopolymers 13, 193-205 (1974)). Poly (d(A-C))poly(d(G-T)) in the presence of ZnTOEpyp(4) gives only one mode of weak binding. The conclusion is that binding of ZnTOEpyp(4) with DNA depends on its nucleotide sequence.     

Intramodal and interaural specificity of the human slow auditory evoked potential

Parameters of slow auditory evoked potentials (SAEPs) recorded during monotonic monaural stimulation and a programmed change in the frequency of successive tonal stimuli were compared. In one variant of polytonic stimulation, besides the frequency, the side of stimulation also was changed (alternation). During polytonic stimulation the amplitude of the SAEPs was greater than during monotonic. Maximal amplitudes were found during alternating polytonic stimulation. A decrease in the variability of amplitude of the SAEPs and an increase in their peak latencies were observed during polytonic stimulation. It is concluded that SAEPs are characterized by intramodal and interaural specificity. The tonotopic and bilaterally symmetrical organizations of the system of SAEP generation can be demonstrated more satisfactorily at low sound intensities. Data indicating that neuron populations of the system of SAEP generation, perceiving tonal stimuli which differ very little from each other "overlap" to a greater degree than populations perceiving more different sounds, are given, The data on intramodal and interaural specificity of the SAEP are discussed from the standpoint of its extralemniscal origin.State Postgraduate Medical Institute, Tbilisi. Translated from Neirofiziologiya, Vol. 9, No. 5, pp. 460–468, September–October, 1977.     

Unraveling regulatory networks in plant defense using microarrays

DNA microarrays are being used to comprehensively examine gene expression networks during the plant defense response that is triggered when a plant encounters a pathogen or an elicitor molecule. In addition to identifying new genes induced during defense, these studies are providing new insights into the complex pathways governing defense gene regulation.     

Is there an inner nose?

Although behavioral and neuropsychological data regarding the existence of images for odors are inconclusive, reconsideration of earlier EEG work provides reasonably clear evidence for an inner nose. However, further EEG studies and neuroimaging data seem essential for conclusive demonstration of an inner nose.      

Distribution and hormonal regulation of membrane progesterone receptors β and γ in ciliated epithelial cells of mouse and human fallopian tubes

Background  

The controlled beating of cilia of the fallopian tube plays an important role in facilitating the meeting of gametes and subsequently transporting the fertilized egg to its implantation site. Rapid effects of progesterone on ciliary beat frequency have been reported in the fallopian tubes of cows, but the identity of the receptors mediating this non-genomic action of progesterone is not known. We recently identified a member of the non-genomic membrane progesterone receptor family, mPR gamma, as a candidate for mediating these actions of progesterone. Here, we investigated the possible presence of a related receptor, mPR beta, in the fallopian tubes of mice and women as well as the possible hormonal regulation of mPR beta and gamma.     

SSWAP: A Simple Semantic Web Architecture and Protocol for semantic web services

Background  

SSWAP (Simple Semantic Web Architecture and Protocol; pronounced "swap") is an architecture, protocol, and platform for using reasoning to semantically integrate heterogeneous disparate data and services on the web. SSWAP was developed as a hybrid semantic web services technology to overcome limitations found in both pure web service technologies and pure semantic web technologies.