Quantitative Analysis of the Microbiota of Periodontal Pockets and Saliva by Real-Time PCR before and after Treatment of Periodontitis

Work has been done on standardization of detection and quantification of periodontopathogenic microorganisms in the clinical material (contents of periodontal pockets and saliva) using real-time PCR. To optimize the conditions for the analysis, a method for obtaining clinical samples of known volume was developed and a calibration sample to obtain reliable results in the diagnosis of periodontitis was designed.     

Activity of rubrospinal neurons in the monkey Macaca mulatta

Action potentials were recorded from single cells of the red nucleus; they were evoked by antidromic stimulation of the rubrospinal tract and by stimulation of the contralateral nucleus interpositus of the cerebellum in monkeys. It was demonstrated that axons go to the spinal cord not only from the large cells of the caudal pole but also from the neurons of the micro cellular part of the red nucleus. The speed of conduction along axons of rubrospinal neurons of monkeys ranges from 17.4–108.8 m/ sec (predominantly 60–90 m/sec). Experiments with stimulation of the cerebellar nucleus interpositus pointed to the existence of a monosynaptic interposito-rubral connection in monkeys.Translated from Zhurnal Évolyutsionnoi Biokhimii i Fiziologii, Vol. 12, No. 1, pp. 56–62, January–February, 1976.     

RFa-related peptides are algogenic: evidence in vitro and in vivo

RFamide (RFa)-related peptides modulate pain processing in the mammalian CNS. The effects of these peptides are generally considered as 'anti-opioid'. They also decrease the rate of desensitization of acid-sensing ionic channels (ASICs), putative nociceptors in dorsal root ganglia neurons [C. Askwith et al. (2000) Neuron, 26, 133-141]. We have tested the role of mollusc-derived peptide, FMRFa (Phe-Met-Arg-Phe-amide) and its synthetic analogues in peripheral nociception. Here we demonstrate that RFa-related peptides powerfully excite the majority of C-fibres in the skin-nerve preparation of rat: 76% of 55 tested fibres with the conduction velocity below 2 m/s responded with long-lasting discharges to the application of peptides (20 microm). When injected subcutaneously in vivo (mice), they initiate nociceptive behaviour. We confirm the data on humans [S. Ugawa et al. (2002) J. Clin. Invest., 110, 1185-1190]: the activation of C-fibres by acid is inhibited by channel blocker of ASICs, amiloride. However, there is no correlation in the sensitivity of C-fibres to RFa peptides, protons and amiloride: 74% of tested RFa-sensitive C-fibres were insensitive to protons and in 67% of cases the response to peptides was insensitive to amiloride. Thus, powerful excitatory/algogenic action of RFa-related peptides cannot be interpreted solely in terms of their interaction with ASICs. The peptides do not activate any conductance in the somatic membrane of dorsal root ganglion neurons of rats and probably affect still unidentified molecular target(s) responsible for nociceptive signalling.     

Inhibitory action of dopamine on excitatory transmission in the isolated spinal cord of the rat

The effect of dopamine on the ventral root potential evoked by single supramaximal dorsal root stimulation was studied in the experiment in the isolated superfused spinal cord of 10-16 days old rats. It was discovered that application of dopamine caused the reversible dose-dependent inhibition of the mono- and polysynaptic ventral root reflex responses. The minimal effective concentration was 1 X 10(-8) mol/l. Dopamine applied in concentrations of 1 X 10(-4) mol/l and 1 X 10(-3) mol/l decreased the amplitude of the monosynaptic ventral root potential by 20% and 87% as against the control, respectively. Under the same conditions the amplitude of the polysynaptic ventral root potential decreased by 18% and 87% as against the control, respectively. The obtained results demonstrate that the dopaminergic brainstem-spinal pathways take part in the control of the transmission in the segmentary reflex arc.     

Effect of vasopressin and oxytocin on the dorsal root potentials of the isolated perfused spinal cord in rat pups

The effect of vasopressin and oxytocin on the dorsal root potentials were studied in isolated spinal cord of 12-16 days old rats. It was shown that both neuropeptides evoked reversible depression of the dorsal root potential induced by stimulation of the neighbouring dorsal root. Application of vasopressin or oxytocin caused the reversible dose-dependent depolarization in the dorsal root. The depolarization was preserved in Ca2+-free manganese-containing solution. Functional significance of presynaptic effects of hypothalamic neuropeptides is discussed.     

Effect of oxytocin on rat dorsal root ganglia in vitro

The influence of bath application of oxytocin (OT) was investigated on the isolated dorsal root ganglion (DRG) cells by means of intracellular recording. The results showed that OT evoked depolarization in most cells and affected predominantly the DRG neurons with biophysical+ characteristics inherent in small neurons.     

Effect of vasopressin and oxytocin on the spontaneous activity of dorsal horn cells of the isolated spinal cord of the rat pup

The effect of vasopressin and oxytocin on background frequency of single cells from the dorsal horn was studied in the isolated spinal cord of 2-3 weeks old rats. It was shown that neurons were predominantly depressed following application both of vasopressin or oxytocin. Vasopressin evoked depression of background activity in 74% cells (29 of 39 responding to vasopressin) and activation in 26% cells (10 from 39). Oxytocin evoked depression in 67% (14 from 21 responding to oxytocin) and activation in 33% cells (7 from 21). All effects were reversible and dose-dependent. Neurons studied either gave the same response both to vasopressin and to oxytoxin or responded only to one of the two peptides.     

Polarization method of examining the fundus and anterior chamber of the eye

The method using polarization light proved to be efficient for examining eye tissues. It provides better contrast of some ocular elements, and thus, more reliable detection of pathological changes, more complete extinction (relaxation) of reflexes which hamper the observation and photograph of different eye parts. To interprete the patterns observed on the fundus in crossed polaroids, a matrix method is recommended for calculation of intensity of light passing through the optically-anisotropic layers of the eye ball. Data of clinical examinations carried out on pilot models of ophthalmological instruments confirmed diagnostic value of the polarization method for the eye study.