Fluid flow along venous adventitia in rabbits: is it a potential drainage system complementary to vascular circulations?

BACKGROUND: Our previous research and other studies with radiotracers showed evidence of a centripetal drainage pathway, separate from blood or lymphatic vessels, that can be visualized when a small amount of low molecular weight tracer is injected subcutaneously into a given region on skin of humans. In order to further characterize this interesting biological phenomenon, animal experiments are designed to elucidate histological and physiologic characteristics of these visualized pathways. METHODS: Multiple tracers are injected subcutaneously into an acupuncture point of KI3 to visualize centripetal pathways by magnetic resonance imaging or fluorescein photography in 85 healthy rabbits. The pathways are compared with venography and indirect lymphangiography. Fluid flow through the pathways is observed by methods of altering their hydrated state, hydrolyzing by different collagenases, and histology is elucidated by optical, fluorescein and electron microscopy. RESULTS: Histological and magnetic imaging examinations of these visualized pathways show they consist of perivenous loose connective tissues. As evidenced by examinations of tracers' uptake, they appear to function as a draining pathway for free interstitial fluid. Fluorescein sodium from KI3 is found in the pathways of hind limbs and segments of the small intestines, partial pulmonary veins and results in pericardial effusion, suggesting systematical involvement of this perivenous pathway. The hydraulic conductivity of these pathways can be compromised by the collapse of their fiber-rich beds hydrolyzed by either of collagenase type I, III, IV or V. CONCLUSIONS: The identification of pathways comprising perivenous loose connective tissues with a high hydraulic conductivity draining interstitial fluid in hind limbs of a mammal suggests a potential drainage system complementary to vascular circulations. These findings may provide new insights into a systematically distributed collagenous connective tissue with a circulatory function and their potential relevance to the nature of acupuncture meridians.

Visualized regional hypodermic migration channels of interstitial fluid in human beings: are these ancient meridians?

BACKGROUND: Since the 1980s, many studies have indicated there are hypodermic migration channels of radiotracer along meridians independent of lymphatic and blood vessels in vivo. However, the radioactive trajectories were not clear enough to identify the anatomic structures in the living body. OBJECTIVES: To establish an alternative method to image the specific fluid pathways, we hypothesized that a minimal amount of low molecular weight tracer could enter the specific channels and by magnetic resonance imaging technique, we could image the regional channels originating from the acupoints on 6 yin meridians of forearm and lower leg. DESIGN AND RESULTS: Seven (7) healthy volunteers were injected hypodermically with a minimal amount of tracer into 6 acupoints on 6 yin meridians of the hand and foot. We found a total of 6 regional specific channels in one forearm and one lower leg of each subject, respectively, but no specific channels were visualized following injection of the tracer into the sites of nonacupoints. Magnetic resonance angiography confirmed the specific channels were not the superficial veins in the subcutis. Subsequent acupuncture needling studies revealed that migration of tracer along each of the specific channels could not be interrupted by acupuncture needling and remained intact, which was different from the nature of either lymphatics or blood vessels. CONCLUSIONS: We imaged 6 regional migration channels originating from 6 acupoints on 6 yin meridians of hand and foot by injecting a minimal amount of tracer into acupoints directly in humans. The responses of the subcutaneous specific channels to acupuncture needling are different from those of lymphatic or blood vessels and coincide partially with the characteristics of acupuncture therapeutics, suggesting the existence of meridian-like channels in humans. These findings may contribute to further research on the specific interstitial fluid drainage.

[A preliminary study on the role of anti-atrial fibrillation pacemaker in the prevention of atrial tachyarrhythmia].

OBJECTIVE: To investigate the effect of anti-atrial fibrillation of Philos DDDR pacemaker on atrial tachyarrhythmia. METHODS: Thirty-eight patients with sick sinus syndrome and paroxysmal atrial fibrillation (AF) were implanted with Philos DDDR pacemaker. After implantation, auto-Mode-Switch (AMS) function was switched "on" and AF preventive algorithms were "off" in all cases. The number of AMS, atrial premature beats, heart rate and the percentage of atrial and ventricular pacing were recorded by pacemaker diagnostic function for one-month after procedure. AF preventive algorithms function with "middle" (approx 8 bpm) was then switched on and the same parameters as above from the database of pacemaker diagnostic function were collected for additional one month. RESULTS: The symptoms of dizziness, dyspnoea, and palpitation in the majority of patients were dramatically improved regardless of whether the AF preventive algorithms function was switched "on" or "off" after pacemaker implantation. There were no significant clinical changes in most patients when AF preventive algorithms were "on". However, 5 cases (13.2%) had palpitations and short of breath. These symptoms were relieved by changing the algorithms from "middle to slight (approx 4 bpm)". When AF preventive algorithms were switched on, atrial premature beats were reduced significantly (P < 0.05) with a dramatic increase in atrial pacing percentage and heart rate (P < 0.05). However, there was no significant difference in AMS (P > 0.05) between the two groups of AF preventive algorithms function switching "on" and "of", indicating that atrial tachyarrhythmias were not inhibited by anti-atrial fibrillation pacemaker. CONCLUSION: This study suggested that atrial fibrillation and atrial tachycardia were not reduced by implantation of an anti-atrial fibrillation Philos DDDR pacemaker, although atrial premature beats decreased significantly with increasing atrial pacing percentage when AF preventive algorithms were in "middle" and "slight".