Erupción primaveral juvenil

La EPJ fue descrita en el año 1954 por Anderson y colaboradores. Desde entonces, las referencias en la literatura son escasas. Esto podría deberse, en parte, al curso benigno y autolimitado por el que se caracteriza y podría ser más frecuente de lo que ha sido reflejado. Se han descrito brotes epidémicos infantiles o en personal militar. Desde el punto de vista epidemiológico, afecta, principalmente, a niños o varones jóvenes con orejas prominentes y ausencia de cabello que las cubre, generalmente, al inicio de la primavera, durante días fríos y soleados. De forma más infrecuente, también se han descrito casos en el sexo femenino. Las lesiones cutáneas aparecen pocas horas tras una exposición solar y se caracterizan por un eritema y edema de fondo, sobre el que aparecen pápulas eritematosas, vesículas y, posteriormente, costras. Su localización principal son los pabellones auriculares, y es rara la afectación en otros niveles. Estas lesiones se curan de forma espontánea y sin dejar cicatriz, y es posible la aparición de nuevos brotes en primaveras sucesivas, aunque, generalmente, de menor intensidad..

Association between adiposity levels and cognitive impairment in the Chilean older adult population

Although both obesity and ageing are risk factors for cognitive impairment, there is no evidence in Chile on how obesity levels are associated with cognitive function. Therefore, the aim of the present study was to investigate the association between adiposity levels and cognitive impairment in older Chilean adults. This cross-sectional study includes 1384 participants, over 60 years of age, from the Chilean National Health Survey 2009–2010. Cognitive impairment was evaluated using the Mini-Mental State Examination. BMI and waist circumference (WC) were used as measures of adiposity. Compared with people with a normal BMI, the odds of cognitive impairment were higher in participants who were underweight (OR 4·44; 95 % CI 2·43, 6·45; P < 0·0001), overweight (OR 1·86; 95 % CI 1·06, 2·66; P = 0·031) and obese (OR 2·26; 95 % CI 1·31, 3·21; P = 0·003). The associations were robust after adjustment for confounding variables. Similar results were observed for WC. Low and high levels of adiposity are associated with an increased likelihood of cognitive impairment in older adults in Chile

Expression of muscarinic acetylcholine receptors (M1-, M2-, M3- and M4-type) in the neuromuscular junction of the newborn and adult rat

Using intracellular recording and immunohistochemistry, we studied the presynaptic muscarinic autoreceptor subtypes controlling ACh release in the neuromuscular junctions of the newborn (3-6 days postnatal) and adult (30-40 days) rat. In the Levator auris longus muscles of both newborn and adult rats, acetylcholine release was modified by the M1- receptor selective antagonists pirenzepine (10 µM) and MT-7 (100 nM) and by the M2-receptor selective antagonists methoctramine (1 µM) and AF-DX 116 (10 µM). The M4-receptor selective antagonists tropicamide (1 µM) and MT-3 (100 nM) can also modify the neurotransmitter release in certain synapses of the newborn muscles. The neurotransmitter release was not altered by the M3-receptor selective antagonist 4-DAMP (1 µM) in the adult or newborn rats. However, we directly demonstrate by immunocytochemistry the presence of these receptors in the motor endplates and conclude that M1-, M2-, M3- and M4-type muscarinic receptors are present in all the neuromuscular junctions of the rat muscle both in newborn and adult animals. These receptors may be located in the perisynaptic glial cell as well as at the nerve terminals

Topological differences along mammalian motor nerve terminals for spontaneous and alpha-Bungarotoxin-induced sprouting

Spontaneous sproutings can be observed in end plates from normal adult vertebrate muscles and motor end plates develop increased growth signs and sprouts when target muscle cells become less active or paralysed. Nevertheless, very little is known about where in the motor nerve terminal arborization spontaneous and experimentally induced sprouts originate, their similarities and differences and also about their final maturation or elimination. In this study we investigate the topological properties of both spontaneous and alpha-bungarotoxin-induced sprouts (during different periods of intoxication and after recovery) along the motor nerve terminal branches of the Levator auris longus muscle of Swiss mice (between 48- 169 day old). Muscles were processed for immunocytochemistry to simultaneously detect postsynaptic AChRs and axons. This procedurk permits us to make an accurate identification of the fine sprouts and a morphometric study of the presynaptic branching pattern profile in control muscles, during the toxin action and after recovery from paralysis. The results show that in normal muscles, the initial and trunk segments (those between branch points) of the terminal arborization sprouted proportionally more branches when taking their relative lengths into account than the distal free-end segments. In contrast, every micrometer of alpha-bungarotoxin-treated muscles throughout the full terminal arborization have the same probability of generating a sprout. Moreover, the toxininduced sprouts can consolidate as new branches once recovered from the paralysis without changing the total length of the nerve terminal arborization

Cellular localization of the atypical isoforms of protein kinase C (aPKCζ/PKMζ and aPKCλ/ι) on the neuromuscular synapse

10.1016/j.neulet.2013.10.00

Adenosine A2B and A3 receptor location at the mouse neuromuscular junction

10.1111/joa.12188To date, four subtypes of adenosine receptors have been cloned (A1R, A2AR, A2BR, and A3R). In a previous study we used confocal immunocytochemistry to identify A1R and A2AR receptors at mouse neuromuscular junctions (NMJs). The data shows that these receptors are localized differently in the three cells (muscle, nerve and glia) that configure the NMJs. A1R localizes in the terminal teloglial Schwann cell and nerve terminal, whereas A2AR localizes in the postsynaptic muscle and in the axon and nerve terminal. Here, we use Western blotting to investigate the presence of A2BR and A3R receptors in striated muscle and immunohistochemistry to localize them in the three cells of the adult neuromuscular synapse. The data show that A2BR and A3R receptors are present in the nerve terminal and muscle cells at the NMJs. Neither A2BR nor A3R receptors are localized in the Schwann cells. Thus, the four subtypes of adenosine receptors are present in the motor endings. The presence of these receptors in the neuromuscular synapse allows the receptors to be involved in the modulation of transmitter release