Meridian theory is a major part of Chinese medicine and has guided acupuncture and clinical practice for thousands of years. Meridian theory describes many important concepts about the rules of human body function and regulation, but has comparatively huge differences with the basic concepts of modern medicine. These differences have caused deep concern and attracted attention from scholars, both inside and outside of China. The interest in meridian theory lies in determining the structural nature of meridians. Not only is this information still unclear, it is very difficult to achieve clear results in a short period of time. Despite this, the phenomena of meridians can be used as the entry point for meridian studies. After many years of effort, although the physical structure of meridians has not been found, the existence of the meridian phenomena has been fully confirmed. Although there is a lack of morphological evidence for the existence of the meridian, concluding non-existence may be incorrect as morphology techniques develop and structures previously not determined are being found. Since the phenomenon of meridians exists, some biological basis behind its occurrence must be present. This implies that research on meridians needs to continue as research techniques advance and may eventually reveal the biological basis of the meridian phenomenon. In the present review, we analyze the history of meridian studies in China.

Cancer growth and dissemination have been extensively studied for a long time. Nevertheless, many new observations on anatomy and histopathology of cancer events are still reported such as formation of a vasculogenic-like network inside aggressive tumors. In this research, new kinds of micro-conduits, named primo-vessels, were found inside the abdominal cavity of NCI-H460 lung cancer murine xenograft models. These vascular threads were largely distributed on the surfaces of various organs and were often connected to peritoneal tumor nodules. Histological and immunofluorescent investigations showed that the primo-vessels had characteristic features that were distinctively different from those of similar-looking lymphatic vessels. They had multiple channels surrounded with loose collageneous matrices, which is in contrast to the single-channel structure of other vascular systems. The rod-shaped nuclei aligned longitudinally along the channels were assumed to be the endothelial cells of the primo-vessels, but LYVE-1, a specific marker of lymphatics, was not expressed, which indicates a clear difference from lymphatic endothelial cells. Taken together these findings on and characterization of the novel threadlike vascular structures in cancer models may have important implications for cancer prognosis and for therapy.

Although wet cupping has been a treatment for centuries, its mechanism of action is not well understood. Because the anatomical features of the wet-cupping area might play a role in its mechanism, we focus on the features of the interscapular area in which a common type of wet-cupping therapy (WCT), called Hijamat-e-Aam in Iranian medicine, is usually applied and discuss the possible relation of those features to the acupuncture meridians. We gathered and analyzed data from reliable textbooks on modern medicine with a focus on the anatomical features of the interscapular area, topics related to WTC in Iranian medicine, and acupuncture sources obtained by searching PubMed, Google-Scholar, and Science Direct. The interscapular area used for WCT was found to have special features: brown adipose tissue, immediate proximity to sympathetic ganglia, passage of the thoracic duct, two important acupuncture meridians, and proximity to the main vessel divisions carrying blood from the heart and the brain. These features indicate that the interscapular application of WCT not only discharges waste materials through a shifting of blood to the site after application of a traction force but also invigorates the body's metabolism, increases immunity, and regulates blood biochemistry, which are desired therapeutic effects of WCT.