Oral malodor in Special Care Patients: current knowledge

Epidemiological studies report that about 50% of the population may have oral malodor with a strong social and psychological impact in their daily life. When intra-oral causes are excluded, referral to an appropriate medical specialist is paramount for management and treatment of extra-oral causes. The intra-oral causes of halitosis are highly common, and the dentist is the central clinician to diagnose and treat them. Pseudohalitosis or halitophobia may occur and an early identification of these conditions by the dentist is important in order to avoid unnecessary dental treatments for patients who need psychological or psychiatric therapy. The organoleptic technique is still considered the most reliable examination method to diagnose genuine halitosis. Special needs patients are more prone than others to have oral malodor because of concurrent systemic or metabolic diseases, and medications. The present report reviews halitosis, its implications, and the management in special care dentistry

Lion-porcupine interactions in Africa, including impacts on lion predatory behavior

Although African crested porcupines Hystrix spp. represent 0.5–34% of lion Panthera leo kills, interactions between the two species are poorly documented. Here we review porcupine-lion interactions and their impact on lion behaviour, including: 1) lion predation on porcupines; 2) lions injured or killed by porcupine quills; and 3) a case of a lion severely injured by a porcupine  quill. Porcupine quills can be effective weapons and sometimes seriously wound lions, resulting in death. Death from quills can be a slow process and under these circumstances, death may be the result of starvation or infection (septicaemia).Keywords: predator-prey relations, quill, behaviour modification, Hayward-Kerley’ threat index, septicaemi

Endothelin-1[1–31], acting as an ETA-receptor selective agonist, stimulates proliferation of cultured rat zona glomerulosa cells

AbstractEndothelin-1 (ET-1)[1–31] is a novel hypertensive peptide that mimics many of the vascular effects of the classic 21 amino acid peptide ET-1[1–21]. However, at variance with ET-1[1–21] that enhances aldosterone secretion from cultured rat zona glomerulosa (ZG) cells by acting via ETB receptors, ET-1[1–31] did not elicit such effect. Both ET-1[1–21] and ET-1[1–31] raised the proliferation rate of cultured ZG cells, the maximal effective concentration being 10−8 M. This effect was blocked by the ETA-receptor antagonist BQ-123 and unaffected by the ETB-receptor antagonist BQ-788. Quantitative autoradiography showed that ET-1[1–21] displaced both [125I]PD-151242 binding to ETA receptors and [125I]BQ-3020 binding to ETB receptors in both rat ZG and adrenal medulla, while ET-1[1–31] displaced only [125I]BQ-3020 binding. The tyrosine kinase (TK) inhibitor tyrphostin-23 and the p42/p44 mitogen-activated protein kinase (MAPK) inhibitor PD-98059 abolished the proliferogenic effect of ET-1[1–31], while the protein kinase-C (PKC) inhibitor calphostin-C significantly reduced it. ET-1[1–31] (10−8 M) stimulated TK and MAPK activity of dispersed ZG cells, an effect that was blocked by BQ-123. The stimulatory action of ET-1[1–31] on TK activity was annulled by tyrphostin-23, while that on MAPK activity was reduced by calphostin-C and abolished by either tyrphostin-23 and PD-98059. These data suggest that ET-1[1–31] is a selective agonist of the ETA-receptor subtype, and enhances proliferation of cultured rat ZG cells through the PKC- and TK-dependent activation of p42/p44 MAPK cascade

Analysis of the intraspinal calcium dynamics and its implications on the plasticity of spiking neurons

The influx of calcium ions into the dendritic spines through the N-metyl-D-aspartate (NMDA) channels is believed to be the primary trigger for various forms of synaptic plasticity. In this paper, the authors calculate analytically the mean values of the calcium transients elicited by a spiking neuron undergoing a simple model of ionic currents and back-propagating action potentials. The relative variability of these transients, due to the stochastic nature of synaptic transmission, is further considered using a simple Markov model of NMDA receptos. One finds that both the mean value and the variability depend on the timing between pre- and postsynaptic action-potentials. These results could have implications on the expected form of synaptic-plasticity curve and can form a basis for a unified theory of spike time-dependent, and rate based plasticity.Comment: 14 pages, 10 figures. A few changes in section IV and addition of a new figur