Lamellar and «club-shaped» corpuscular nerve endings in human gingival mucosa. A light and electron microscopic study

A study on the presence of corpuscular nerve endings in human gingival mucosa was performed using both light and transmission electron microscopic (TEM) techniques. Both round and oval lamellar corpuscles were detected by light microscopy. They were located either subepithelially, close to the basement membrane, or within the papillae, deeply invaginated into the overlying epithelium. TEM techniques showed convoluted structures with unmyelinated fibre arborizations leading to an afferent fibre supported by the so called lamellar cells. The presence of blood vessels, collagenous fibrils, desmosome-like junctions, cytoplasmic organelles, as well as the similarity with some previously described mechanoreceptors, suggested the role of such corpuscular nerve endings in transmitting a nervous impulse induced by mechanical stimulation. Other simpler structures were also observed and named «club-shaped» corpuscles: they could support the more complex ones in responding to the strengths and the movements directly influencing the gingival mucosa.La présence de terminaisons nerveuses corpusculaires dans la muqueuse gingivale humaine a été observée tant en microscopie optique qu’en microscopie électronique à transmission. En microscopie optique on a remarqué des corpuscules lamellaires ronds et ovalaires, qui étaient localisés tant au dessous de l’épithélium, tout près de la membrane basale, qu’au dedans des papilles, profondément insérés dans l’épithélium.En microscopie électronique on a observé des structures convolutées pourvues d’arborisations de fibres nerveuses sans myéline qui vont se réunir dans une fibre afférente supportée par des cellules dites lamellaires. La présence de vaisseaux, de fibrilles collagènes, de jonctions telles que desmoses, d’inclusions cytoplasmiques autant que la ressemblance avec quelques mécanorécepteurs décrits en littérature, suggérait un rôle de ces terminaisons nerveuses corpusculaires en envoyant un impulse nerveux induit par une stimulation mécanique. On a aussi observé des corpuscules plus simples appelés «club-shaped» qui pourraient supporter les plus complexes dans la réponse aux forces et aux mouvements qui influencent directement la muqueuse gingivale

Development of a Novel Snom Probe for in Liquid Biological Samples

This work is focused on the study and implementation of a novel method for the development of probes for Scanning Near-field Optical Microscopy (SNOM). The proposed approach is based on the mechanical impedance matching between the optical fiber tip and the resonating tuning fork. This methodology allowed an increase of the quality factor of the piezoelectric resonator used as atomic force transducer in the SNOM probe, thus increasing its overall sensitivity. This kind of probes are often used on biological soft samples in liquid. The presence of water medium has a strong dumping effect on probe sensitivity. Experimental validation of the proposed methodology showed an increase of robustness of SNOM probes also for in liquid samples

Comparing the efficacy in reducing brain injury of different neuroprotective agents following neonatal hypoxia-ischemia in newborn rats: a multi-drug randomized controlled screening trial

Intrapartum hypoxia-ischemia leading to neonatal encephalopathy (NE) results in significant neonatal mortality and morbidity worldwide, with > 85% of cases occurring in low- and middle-income countries (LMIC). Therapeutic hypothermia (HT) is currently the only available safe and effective treatment of HIE in high-income countries (HIC); however, it has shown limited safety or efficacy in LMIC. Therefore, other therapies are urgently required. We aimed to compare the treatment effects of putative neuroprotective drug candidates following neonatal hypoxic-ischemic (HI) brain injury in an established P7 rat Vannucci model. We conducted the first multi-drug randomized controlled preclinical screening trial, investigating 25 potential therapeutic agents using a standardized experimental setting in which P7 rat pups were exposed to unilateral HI brain injury. The brains were analysed for unilateral hemispheric brain area loss after 7 days survival. Twenty animal experiments were performed. Eight of the 25 therapeutic agents significantly reduced brain area loss with the strongest treatment effect for Caffeine, Sonic Hedgehog Agonist (SAG) and Allopurinol, followed by Melatonin, Clemastine, ß-Hydroxybutyrate, Omegaven, and Iodide. The probability of efficacy was superior to that of HT for Caffeine, SAG, Allopurinol, Melatonin, Clemastine, ß-hydroxybutyrate, and Omegaven. We provide the results of the first systematic preclinical screening of potential neuroprotective treatments and present alternative single therapies that may be promising treatment options for HT in LMIC

Post-operative pain management through music-induced analgesia: Investigating musical constructs

Distraction and attention-diversion approaches are widely integrated into pain management. Music-induced analgesia, the ability of music to reduce pain perception, is a clinically-relevant approach for managing pain, anxiety and psychological well-being. Research categorises audio-analgesic interventions as homogenous, however enquiry is required to identify which musical constructs may be therapeutically effective. This study investigated the impact of harmony and rhythm on acute, post-operative pain in a sample of 98 patients scheduled for knee surgery. Four music listening groups were compared against controls using silent relaxation. After surgery using standardised anaesthesia, participants undertook a 15-minute intervention per day of in-patient stay. Measures of pain intensity, pain interference, salivary cortisol concentration and mood were obtained. All participants showed reductions in pain from pre- to post-test, indicating silent relaxation was as effective as music listening. Salivary cortisol concentrations showed that music with high harmonicity/rhythmicity reduced cortisol concentration to a greater extent on Day 1 than music with low harmonicity/rhythmicity. These findings validate the homogenous use of auditory distraction for audio-analgesia, and importantly emphasise the core role of compositional musical constructs in maximising early postoperative recovery. Results support the need for additional psychobiological research examining the efficacy of audio-analgesic attention-diversion interventions used in pain management

The influence of a virtual companion on amusement when watching funny films

We investigated the role of a virtual companion and trait cheerfulness on the elicitation of amusement. Ninety participants watched funny films in four conditions: either alone, with a virtual companion laughing or verbally expressing amusement at fixed time points (pre-scripted), or additionally joining the participant’s laughter (responsive companion). Amusement was assessed facially and vocally by coding Duchenne Displays and laughter vocalizations. Participants’ cheerful mood pre and post the film watching and positive experience were assessed. Results showed that high trait cheerful individuals generally experienced and expressed more amusement than low trait cheerful individuals. The presence of a virtual companion (compared to being alone) led to more laughter for individuals low in trait cheerfulness. Unexpectedly, the responsive companion did not elicit more amusement than the pre-scripted companion. The general disliking of virtual companions and gelotophobia related negatively to amusement. Amusement expressing virtual companions may be used in interventions aiming at eliciting positive responses, especially for individuals with higher thresholds for amusement.European Union Seventh Framework Programme (FP7/2007-2013) under Grant Agreement No. 27078