Primo Vascular System

                         Primo Vascular System

Primo Vascular System: Past, Present, and Future

What is Primo Vascular System (PVS)? Let us take a journey through oriental medicine in a time machine. Over the past 2000 years, acupuncture and moxibustion in Chinese medicine have been developed based on the concept of the meridian system; however, the anatomical reality of the meridian system has been controversial in various aspects. Even today, the meridian system is still being investigated with well-known anatomical structures. Among them, connective tissues called the fascia system are representative ones for which the putative function of the meridian system has been established and is understood.

A fundamental insight into the acupuncture meridian system and its novel anatomical structures was conceived by Kim in the 1960s. According to his idea, the meridian system has the role of circulating DNA microparticles, named “Signals,” with several hormones independently from the cardiovascular and the lymph systems. In the 1970s, Fujiwara tried to duplicate and verify Kim’s findings; however, his works have also been neglected. Since 2002, Soh’s group at Seoul National University, Republic of Korea, has tried to verify the findings of Bonghan Kim’s work, and they found much evidence suggesting that Bonghan Kim’s ideas on the acupuncture meridian system are reasonable.

At present, what do we study about the PVS? to answer this question and for insight into current works on this novel system, we have a new special issue, Primo Vascular System, in which we have published several research papers and a few review articles. The research papers can be classified as those directly related to the function of PVS and those focusing on the discovery of this new PVS. Representative articles in the former category are the C. H. Leem group’s stem cell work “Expression of stem cell markers in primo vessel of rat,” and K.-S. Soh group’s endothelial cell work “Discovery of endothelium and mesenchymal properties of primo vessels in the mesentery.” In the latter category are the works of Y. H. Ryu laboratory “Primo vascular system accompanying a blood vessel from tumor tissue and a method to distinguish it from the blood or the lymph system” S. Z. Yoon’s medical team “Composition of the extracellular matrix of lymphatic novel threadlike structures: is it keratin?”and B.-C. Lee’s laboratory “Evidence for the primo vascular system above the epicardia of rat hearts.” Also, a Chinese team led by X. Jing has published a very meaningful idea that the PVS could represent artifacts from pathological conditions “Preliminary research of relationship between acute peritonitis and celiac primo vessels,”but another Chinese team led by W.-B. Zhang has suggested via heparin treatment that the PVS might have real anatomical structures “Study on the formation of novel threadlike structure through intravenous injection of heparin in rats and refined observation in minipigs.” Based on these data, admittedly, at present, for the PVS to be established absolutely, an international exchange is needed.

In the future, what will we study about the PVS? Based on our long research careers, we editors suggest the following areas of study to establish an international unified consensus for the novel system that is called the Primo Vascular System:(1)the establishment of the Primo Vascular System in terms of a novel circulation system,(2)the concept of “Sanal” and the relationship between stem cells and Sanals,(3)the involvement of Sanals in cancer metastasis,(4)The potential of the PVS in the brain for diagnosing and treating degenerative brain diseases.

Now let us think of “time” by leaving the time machine. Time really flows in only one direction, toward the future! Thus, our research minds should be directed beyond the past and the present and toward the future. With free, dedicated efforts toward human-oriented holistic medicine, we should be able to build a real evidence-based alternative medicine. Given the present circumstances, a new circulation concept, the Primo Vascular System, is waiting for us to establish fully its potential for benefitting all mankind in ways not previously known.

Visualization of the Primo Vascular System,a Putative Cancer Metastasis Thread Afloat in a Lymph Duct

Because of the potential roles of the primo vascular system (PVS) in cancer metastasis, immune function, and regeneration, understanding the molecular biology of the PVS is desirable. The current state of PVS research is comparable to that of lymph research before the advent of LYVE-1. There is very little knowledge of the molecular biology of the PVS due to difficulties in identifying and isolating primo endothelial cells. Present investigations rely on the morphology and the use of differential staining procedures to identify the PVS within tissues, making detailed molecular studies all but impossible. To overcome such difficulties, one may emulate the explosive development of lymph molecular biology. For this, one needs a reliable method to obtain PVS specimens to initiate the molecular investigation. One of the most reliable methods is to detect the PVS afloat in the lymph flow. The protocols for observation of the PVS in large lymph ducts in the abdominal cavity and the thoracic cavity were reported earlier. These methods require a laparectomy and skillful techniques. In the current work, we present a protocol to identify and harvest PVS specimens from the lymph ducts connecting the inguinal and the axillary nodes, which are located entirely in the skin. Thus, the PVS specimen is more easily obtainable. This method is a stepping stone toward development of a system to monitor migration of cancer cells in metastasis from a breast tumor to axillary nodes, where cancer cells use the PVS as a survival rope in hostile lymph flow.

Primo Vascular System in Human Umbilical Cord and Placenta

The primo vascular system (PVS) has been observed in various animals such as mice, rats, rabbits, dogs, swine, and cow, but not in humans. In this work, we report on the observation of a human PVS on both the epithelial fascia and inside the blood vessels of the umbilical cord (UC). The main morphological characteristics of the primo vessels (PVs) and primo nodes (PNs) from the human UC were in agreement with those of the PVS in various animal organs, including the thicknesses and the transparency of the PVs, the sizes of the PNs, the broken-line arrangement of the rod-shaped nuclei, the sparse distribution of nuclei, and the presence of hollow lumens in the central inner parts of the PNs. It was rather surprising that the human PV was not thicker than the PVs from small animals. The difference between the PVS and blood/lymph vessels was confirmed using immunofluorescence staining of von Willebrand factor, CD31, LYVE-1, and D2-40. The positive expression of the PVS to proliferating cell nuclear antigen, a cell-proliferation marker, was consistent with the recent finding of very small embryonic-like stem cells in the PVS of mice.