Mechanics of soil erosion from overland flow generated by simulated rainfall

September 1973.Bibliography: pages 53-54

Use of an antibiotic growth promoter and two herbal natural feed additives with and without exogenous enzymes in wheat based broiler diets

No Abstract. South African Journal of Animal Science Vol. 35 (1) 2005: pp.61-7

Effects of Nigella sativa seeds and certain species of fungi extracts on number and activation of dural mast cells in rats

In this study, we aimed to investigate the effects of Nigella sativa seeds and certain species of fungi extracts on the number and degranulation states of dural mast cells in rats. Rats were fed ad libitum with normal tap water or tap water with extract of N. sativa seed, Ramaria condensata, Lactarius salmonicolor, Lactarius piperatus, and Tricholoma terreum for 3 days. Mast cells in dura mater were counted and evaluated in terms of granulation and degranulation states. Compound 48/80, a mast cell degranulating agent, and T. terreum significantly increased the percent of degranulated mast cells in dura mater, respectively (p < 0.01 and p < 0.05). Moreover, T. terreum causes a significant increase in the total number of mast cells (p < 0.05). N. sativa significantly inhibited mast cell degranulation induced by both the compound 48/80 and T. terreum (p < 0.05), and significantly decreased the mast cell numbers increased by T. terreum (p < 0.05). Our results suggested that T. terreum following ingestion can contribute to headaches like migraine via dural mast cell degranulation and N. sativa may be able to exert analgesic and anti-inflammatory effects by stabilizing dural mast cells. However, investigation is needed to determine the ingredients of N. sativa that may be responsible for these beneficial effects

Hunting for origins of migraine pain: cluster analysis of spontaneous and capsaicin-induced firing in meningeal trigeminal nerve fibers

International audienceTrigeminal nerves in meninges are implicated in generation of nociceptive firing underlying migraine pain. However, the neurochemical mechanisms of nociceptive firing in meningeal trigeminal nerves are little understood. In this study, using suction electrode recordings from peripheral branches of the trigeminal nerve in isolated rat meninges, we analyzed spontaneous and capsaicin-induced orthodromic spiking activity. In control, biphasic single spikes with variable amplitude and shapes were observed. Application of the transient receptor potential vanilloid 1 (TRPV1) agonist capsaicin to meninges dramatically increased firing whereas the amplitudes and shapes of spikes remained essentially unchanged. This effect was antagonized by the specific TRPV1 antagonist capsazepine. Using the clustering approach, several groups of uniform spikes (clusters) were identified. The clustering approach combined with capsaicin application allowed us to detect and to distinguish "responder" (65%) from "non responder" clusters (35%). Notably, responders fired spikes at frequencies exceeding 10 Hz, high enough to provide postsynaptic temporal summation of excitation at brainstem and spinal cord level. Almost all spikes were suppressed by tetrodotoxin (TTX) suggesting an involvement of the I I X-sensitive sodium channels in nociceptive signaling at the peripheral branches of trigeminal neurons. Our analysis also identified transient (desensitizing) and long-lasting (slowly desensitizing) responses to the continuous application of capsaicin. Thus, the persistent activation of nociceptors in capsaicin-sensitive nerve fibers shown here may be involved in trigeminal pain signaling and plasticity along with the release of migraine-related neuropeptides from TRPV1 positive neurons. Furthermore, cluster analysis could be widely used to characterize the temporal and neurochemical profiles of other pain transducers likely implicated in migraine

Nucleotide homeostasis and purinergic nociceptive signaling in rat meninges in migraine-like conditions

© 2016, Springer Science+Business Media Dordrecht.Extracellular ATP is suspected to contribute to migraine pain but regulatory mechanisms controlling pro-nociceptive purinergic mechanisms in the meninges remain unknown. We studied the peculiarities of metabolic and signaling pathways of ATP and its downstream metabolites in rat meninges and in cultured trigeminal cells exposed to the migraine mediator calcitonin gene-related peptide (CGRP). Under resting conditions, meningeal ATP and ADP remained at low nanomolar levels, whereas extracellular AMP and adenosine concentrations were one-two orders higher. CGRP increased ATP and ADP levels in meninges and trigeminal cultures and reduced adenosine concentration in trigeminal cells. Degradation rates for exogenous nucleotides remained similar in control and CGRP-treated meninges, indicating that CGRP triggers nucleotide release without affecting nucleotide-inactivating pathways. Lead nitrate-based enzyme histochemistry of whole mount meninges revealed the presence of high ATPase, ADPase, and AMPase activities, primarily localized in the medial meningeal artery. ATP and ADP induced large intracellular Ca2+ transients both in neurons and in glial cells whereas AMP and adenosine were ineffective. In trigeminal glia, ATP partially operated via P2X7 receptors. ATP, but not other nucleotides, activated nociceptive spikes in meningeal trigeminal nerve fibers providing a rationale for high degradation rate of pro-nociceptive ATP. Pro-nociceptive effect of ATP in meningeal nerves was reproduced by α,β-meATP operating via P2X3 receptors. Collectively, extracellular ATP, which level is controlled by CGRP, can persistently activate trigeminal nerves in meninges which considered as the origin site of migraine headache. These data are consistent with the purinergic hypothesis of migraine pain and suggest new targets against trigeminal pain

Hunting for origins of migraine pain: Cluster analysis of spontaneous and capsaicin-induced firing in meningeal trigeminal nerve fibers

© 2015 Zakharov, Vitale, Kilinc, Koroleva, Fayuk, Shelukhina, Naumenko, Skorinkin, Khazipov and Giniatullin. Trigeminal nerves in meninges are implicated in generation of nociceptive firing underlying migraine pain. However, the neurochemical mechanisms of nociceptive firing in meningeal trigeminal nerves are little understood. In this study, using suction electrode recordings from peripheral branches of the trigeminal nerve in isolated rat meninges, we analyzed spontaneous and capsaicin-induced orthodromic spiking activity. In control, biphasic single spikes with variable amplitude and shapes were observed. Application of the transient receptor potential vanilloid 1 (TRPV1) agonist capsaicin to meninges dramatically increased firing whereas the amplitudes and shapes of spikes remained essentially unchanged. This effect was antagonized by the specific TRPV1 antagonist capsazepine. Using the clustering approach, several groups of uniform spikes (clusters) were identified. The clustering approach combined with capsaicin application allowed us to detect and to distinguish “responder” (65%) from “non-responder” clusters (35%). Notably, responders fired spikes at frequencies exceeding 10 Hz, high enough to provide postsynaptic temporal summation of excitation at brainstem and spinal cord level. Almost all spikes were suppressed by tetrodotoxin (TTX) suggesting an involvement of the TTX-sensitive sodium channels in nociceptive signaling at the peripheral branches of trigeminal neurons. Our analysis also identified transient (desensitizing) and long-lasting (slowly desensitizing) responses to the continuous application of capsaicin. Thus, the persistent activation of nociceptors in capsaicin-sensitive nerve fibers shown here may be involved in trigeminal pain signaling and plasticity along with the release of migraine-related neuropeptides from TRPV1 positive neurons. Furthermore, cluster analysis could be widely used to characterize the temporal and neurochemical profiles of other pain transducers likely implicated in migraine

Effects of Ambient Air Pollution on Hemostasis and Inflammation

BACKGROUND: Air pollution has consistently been associated with increased morbidity and mortality due to respiratory and cardiovascular disease. Underlying biological mechanisms are not entirely clear, and hemostasis and inflammation are suggested to be involved. OBJECTIVES: Our aim was to study the association of the variation in local concentrations of airborne particulate matter (PM) with aerodynamic diameter < 10 mu m, carbon monoxide, nitrogen monoxide, nitrogen dioxide, and ozone with platelet aggregation, thrombin generation, fibrinogen, and C-reactive protein (CRP) levels in healthy individuals. METHODS: From 40 healthy volunteers, we collected 13 consecutive blood samples within a 1-year period and measured light-transmittance platelet aggregometry, thrombin generation, fibrinogen, and CRP. We performed regression analysis using generalized additive models to study the association between the hemostatic and inflammatory variables, and local environmental concentrations 0 air pollutants for time lags within 24 hr before blood sampling or 24-96 hr before blood sampling. RESULTS: In general, air pollutants were associated with platelet aggregation [average, +8% per interquartile range (IQR), p < 0.01] and thrombin generation (average, +1% per IQR, p < 0.015). Platelet aggregation was not affected by in vitro incubation of plasma with PM. We observed no relationship between any of the air pollutants and fibrinogen or CRP levels. CONCLUSIONS:. Air pollution increased platelet aggregation as well as coagulation activity but had no clear effect on systemic inflammation. These prothrombotic effects may partly explain the relationship between air pollution and the risk of ischemic cardiovascular disease

PETAL LOSS, a trihelix transcription factor gene, regulates perianth architecture in the Arabidopsis flower

Perianth development is specifically disrupted in mutants of the PETAL LOSS (PTL) gene, particularly petal initiation and orientation. We have cloned PTL and show that it encodes a plant-specific trihelix transcription factor, one of a family previously known only as regulators of light-controlled genes. PTL transcripts were detected in the early-developing flower, in four zones between the initiating sepals and in their developing margins. Strong misexpression of PTL in a range of tissues universally results in inhibition of growth, indicating that its normal role is to suppress growth between initiating sepals, ensuring that they remain separate. Consistent with this, sepals are sometimes fused in ptl single mutants, but much more frequently in double mutants with either of the organ boundary genes cup-shaped cotyledon1 or 2. Expression of PTL within the newly arising sepals is apparently prevented by the PINOID auxin-response gene. Surprisingly, PTL expression could not be detected in petals during the early stages of their development, so petal defects associated with PTL loss of function may be indirect, perhaps involving disruption to signalling processes caused by overgrowth in the region. PTL-driven reporter gene expression was also detected at later stages in the margins of expanding sepals, petals and stamens, and in the leaf margins; thus, PTL may redundantly dampen lateral outgrowth of these organs, helping define their final shape

Serotonergic mechanisms of trigeminal meningeal nociception: Implications for migraine pain

Serotonergic mechanisms play a central role in migraine pathology. However, the region-specific effects of serotonin (5-HT) mediated via multiple types of receptors in the nociceptive system are poorly understood. Using extracellular and patch-clamp recordings, we studied the action of 5-HT on the excitability of peripheral and central terminals of trigeminal afferents. 5-HT evoked long-lasting TTX-sensitive firing in the peripheral terminals of meningeal afferents, the origin site of migraine pain. Cluster analysis revealed that in majority of nociceptive fibers 5-HT induced either transient or persistent spiking activity with prevailing delta and theta rhythms. The 5-HT3-receptor antagonist MDL-72222 or 5-HT1B/D-receptor antagonist GR127935 largely reduced, but their combination completely prevented the excitatory pro-nociceptive action of 5-HT. The 5-HT3 agonist mCPBG activated spikes in MDL-72222-dependent manner but the 5HT-1 receptor agonist sumatriptan did not affect the nociceptive firing. 5-HT also triggered peripheral CGRP release in meninges, which was blocked by MDL-72222.5-HT evoked fast membrane currents and Ca2+ transients in a fraction of trigeminal neurons. Immunohistochemistry showed expression of 5-HT3A receptors in fibers innervating meninges. Endogenous release of 5-HT from degranulated mast cells increased nociceptive firing. Low pH but not histamine strongly activated firing. 5-HT reduced monosynaptic inputs from trigeminal Aδ- and C-afferents to the upper cervical lamina I neurons and this effect was blocked by MDL-72222. Consistent with central inhibitory effect, 5-HT reduced CGRP release in the brainstem slices. In conclusion, 5-HT evokes powerful pro-nociceptive peripheral and anti-nociceptive central effects in trigeminal system transmitting migraine pain.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The study was supported by the Finnish Academy (grant 277442). AZ was supported by the subsidy allocated to Kazan Federal University for the state assignment in the sphere of scientific activities and the Government of the Russian Federation (grant No.11.G34.31.0075). The work of IS was supported by RFBR grant 14-04-00885. BVS was supported by the grant from the Fundacao para a Ciencia e a Tecnologia (PTDC/NEU-NMC/1259/2014) and from the programme NORTE 2020