Gastroprotection induced by capsaicin in healthy human subjects

AIM： To evaluate the gastro-protective effect of capsaicin against the ethanol- and indomethacin （IND）-induced gastric mucosal damage in healthy human subjects. METHODS： The effects of small doses （1-8 μg/mL, 100 mL） of capsaicin on the gastric acid secretion basal acid output （BAO） and its electrolyte concentration, gastric transmucosal potential difference （GTPD）, ethanol- （5 mL 300 mL/L i.g.） and IND- （3×25 mg/d） induced gastric mucosal damage were tested in a randomized, prospective study of 84 healthy human subjects. The possible role of desensitization of capsaicin-sensitive afferents was tested by repeated exposures and during a prolonged treatment. RESULTS： Intragastric application of capsaicin decreased the BAO and enhanced “non-parietal” component, GTPD in a dose-dependent manner. The decrease of GTPD evoked by ethanol was inhibited by the capsaicin application, which was reproducible. Gastric microbleeding induced by IND was inhibited by co-administration with capsaicin, but was not influenced by two weeks pretreatment with a daily capsaicin dose of 3×400μg i.g. CONCLUSION： Capsaicin in low concentration range protects against gastric injuries induced by ethanol or IND, which is attributed to stimulation of the sensory nerve endings.

Co-firing of levator palpebrae and masseter muscles links the masticatory and oculomotor system in humans

Simultaneous co-firing of the levator palpebrae （LP） and pterygoid muscles were recorded in Marcus Gann Syndrome （MGS） patients in early clinical studies. ＂Release hypothesis＂ proposed an intrinsic masticatory oculo- motor neural circuit and this kind circuit, which, however, has been observed only in amphibian. On the other hand, congenital miswiring hypothesis has overwhelmed other interpretations. However, the same phenomenon visualized in MGS cases was unveiled in human subjects without any sign of congenital oculomotor disorder. To further study co-firing of the upper eyelid and jaw muscles, we applied non-invasive EMG recording of the upper eyelid and ipsilateral masseter muscle belly in nine healthy volunteers. LP activity was determined initially by looking upward and active retraction of upper eyelid with head fixed. Then, dual channel inputs from upper eyelid and masseter muscle was recorded during tooth occlusion motivated by isometric masseter muscle contraction without jaw and face moving. The EMG recorded from upper eyelid when the subjects retracted eyelid with head fixed exhibited the same pattern as that collected during tooth occlusion, but the pattern was completely different from EMG of active eye closure. This reflects tooth occlusion evoked LP activity. Then, simultaneous co-firing of the LP and masseter muscle was recorded simultaneously during tooth occlusion without jaw movement. Finally, the aforemen- tioned co-firing was recorded when the subjects conducted rhythmic occlusion and synchronous EMG from both muscles was acquired. In conclusions, humans may also have an intrinsic masticatory oculomotor circuit and release hypothesis may apply, at least, to some cases of MGS.

Effects of cupping on blood flow under skin of back in healthy human

Objective To observe the effects of cupping on blood flow under different skins of back in healthy human. Methods With meridian-cupping dredging apparatus to set cupping pressure at -0.04 MPa, cupping was applied at Dhzhui （大椎 GV 14） and bilateral Dazhu （大杼 BL 11） for 10 min in healthy subject. Blood flow monitoring video system of laser speckle was used to record blood flow of GV 14, Shenzhu （身柱 GV 12）, bilateral Feishu （肺俞 BL 13） and Xinshu （心俞 BL 15） before cupping therapy, immediate time of cupping removal and 5 min, 10 rain, 15 min, 20 min, 25 rain and 30 rain after cupping removal. Results Compared before cupping therapy, the blood flow of GV 14, GV 12 and bilateral BL 13 was obviously increased at immediate time of cupping removal （all P〈0.05）. Compared with immediate time of cupping removal, the blood flow of GV 14 at each time point after 20 rain of cupping removal, GV 12 at 10 min and 15 min after cupping removal, bilateral BL 13 at each time point after cupping removal was all obviously decreased （all P〈0.05）. The difference of blood flow of Shendao （神道 GV 11） and bilateral BL 15 before and after cupping therapy was not significantly different （all P〉0.05）. Conclusion The cupping therapy could adjust skin blood flow, which is more obvious near the cupping area.