Activation of group II metabotropic glutamate receptors blocks zinc release from hippocampal mossy fibers

BACKGROUND: The hippocampal CA3 area contains large amounts of vesicular zinc in the mossy fiber terminals which is released during synaptic activity, depending on presynaptic calcium. Another characteristic of these synapses is the presynaptic localization of high concentrations of group II metabotropic glutamate receptors, specifically activated by DCG-IV. Previous work has shown that DCG-IV affects only mossy fiber-evoked responses but not the signals from associational-commissural afferents, blocking mossy fiber synaptic transmission. Since zinc is released from mossy fibers even for single stimuli and it is generally assumed to be co-released with glutamate, the aim of the work was to investigate the effect of DCG-IV on mossy fiber zinc signals. RESULTS: Studies were performed using the membrane-permeant fluorescent zinc probe TSQ, and indicate that DCG-IV almost completely abolishes mossy fiber zinc changes as it does with synaptic transmission. CONCLUSIONS: Zinc signaling is regulated by the activation of type II metabotropic receptors, as it has been previously shown for glutamate, further supporting the corelease of glutamate and zinc from mossy fibers.

Efficacy and tolerability of diphenylcyclopropenone in the treatment of alopecia areata

Though many therapies exist for alopecia areata, one of the most unique is topical sensitization. Sensitizers as DPCP offer an attractive treatment option for many patients with alopecia areata, including those who have previously failed more traditional treatments and those who have extensive disease. The present study was done to evaluate the efficacy and tolerability of DPCP in the treatment of AA. Twenty five patients with AA were included in this study and divided into two groups: Group I, consists of 20 patients divided into 2 subgroups [subgroup Ia, 10 AA patients of less than 50% scalp hair loss and subgroup Ib, 10 AA patients of more than 50% scalp hair loss]. Group II included five patients with AT. After sensitization with 2% DPCP, progressively higher concentrations, beginning at 0.001%, were applied weekly for 6 months. Collectively, 23 out of the twenty-five patients [92%] showed variable grades of hair regrowth; 17 patients [68%] showed complete hair regrowth, 4 patients [16%] showed patchy terminal hair regrowth, 2 patients [8%] showed sparse pigmented hair and 2 patients [8%] showed no response at all. Reported adverse reactions were occasional episodes of contact dermatitis, cervical lymphadenopathy, generalized pruritus and pigmentary changes. Topical sensitization with DPCP offers a unique therapeutic alternative to traditional treatments for AA. It also offers many advantages over other treatments in extensive AA

Inmunoterapia tópica en el tratamiento de la alopecia areata / Topical immunotherapy in alopecia areata treatment

La alopécia areata (AA) es una patología realtivamente frecuente del folículo piloso. Su etiología, si bien es desconocida, probablemente corresponda a un fenómeno autoinmune, aunque factores genéticos y ambientales también estarían involucrados. La inmunoterapia tópica es la modalidad terapéutica más efectiva y aceptada en el tratamiento de la AA crónica severa. La inmunoterapia tópica se define como la inducción y posterior provocación periódica de una dermatitis de contacto alérgica, a través de la aplicación de un potente alergeno de contacto en una zona cutánea determinada. Han sido utilizados tres alergenos de contacto en el tratamiento de la alopecia areata: dinitroclorobenceno (DNCB), dibutil éster del ácido escuárico (SADBE) y difenciprona (DPC). En el presente trabajo se describen las principales características de estos agentes tópicos

Fundamentos técnicos y físicos para la administración de óxido nitroso en la Ciudad de México / Rationale for use of nitrous oxide

Siempre se ha especulado que a una altura de 2 200 metros sobre el nivel del mar la presión parcial alveolar del óxido nitroso es insuficiente para permitir su difusión a través de la membrana alvéol-capilar y, por tanto, hay imposibilidad para lograr las concentraciones sanguíneas necesarias para el estado anestésico sin trastornar seriamente el aporte de oxígeno a la célula. En el Hospital Central Militar, desde el decenio de 1970, previa eliminación del nitrógeno alveolar mediante flujos altos, se ha administrado con resultados excelentes óxido nitroso en combinación con otros fármacos ya sea por vía parenteral o pulmonar. Después, al reducir el flujo total y aplicar óxido nitroso a través de un circuito semicerrado o semiabierto evitan las pérdidas excesivas de agua, temperatura y bióxido de carbono, a la vez que se abate el grado de contaminación ambiental, y de esta forma aumenta el ahorro de anestésicos halogenados

Effects of ackee fruit extracts on bronchomotor tone in rats

The unripe ackee fruit, when eaten, is known to cause serious clincial manifestations, including vomitting, hypoglycaemia and acidosis. The effects, of various extracts from the arilli of the unripe ackee fruit (including hypoglycin-A) on the lungs from rats were examined in an in vitro preparation. All the extracts were found to induce moderately severe broncho-constriction, indicating a possible contribution of these effects to the observed toxicity of ackee