Gross morphological features of the organ surface primo-vascular system revealed by hemacolor staining

Primo Vessels Inside Lymphatic Vessels Are Absent in an ALS Mouse Model

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease characterized by the selective death of motor neurons in the central nervous system. It is also a representative rare disease among degenerative diseases of the nervous system. Although many drugs for the treatment of degenerative brain diseases are being developed, they are not delivered correctly to the target due to the blood-brain barrier. The present study aimed to analyze changes in the primo vascular system (PVS) in ALS mice with symptoms and the partial oxygen pressure (pO2) in normal mice. In normal mice, we consistently observed primo vessels in lymphatic vessels (L-PVS). However, in ALS mice with symptoms, L-PVS were mostly lost, rendering them difficult to observe. The pO2 of the L-PVS in normal mice was significantly higher than that of normal dermis and lymph nodes.In conclusion, the relatively higher oxygen levels measured in the L-PVS than in normal dermis and lymph nodes suggest a role for the PVS in oxygen transport and enable a hypothesis that the L-PVS can function as a drug delivery pathway.

Tissue Concentration Analysis of Sulfur, Calcium and Oxygen in Novel Skin Primo Nodes After Acupuncture

Over the past 5000 years, acupuncture has been practiced in Korea, China, and Japan to relieve various diseases, and it is now widely used and accepted worldwide. Although the anatomical substance and function of meridians has been actively studied, it is still not clearly defined. One of the keys to acupuncture is determining the specific anatomical location exactly on or under the skin. We discovered that the skin primo node is a new anatomical structure in the skin of rats. The present study aimed to analyze the relationship between skin primo nodes and acupoints through changes in the expression of tissue concentrations of skin primo nodes. Analysis of this skin primo node confirmed that the skin primo node after acupuncture had a significantly higher concentration of sulfur and calcium than found in normal skin. And the significant pO2 in the skin primo node was confirmed by measuring pO2 using a needle oxygen sensor. Through sulfur, calcium, and pO2 concentration values of skin primo nodes, we confirmed whether these nodes could be related to acupoint. To understand the clear structure and function of this node, it is necessary to further study through the known properties of acupoints and the function of Primo Vascular System (PVS).

Primo Bundles Identified by Microcomputed Tomography in Primo Vascular Tissue on the Surface of Rat Abdominal Organs

BACKGROUND

The primo vascular system (PVS) is a novel network composed of primo nodes (PNs) and primo vessels (PVs). Currently, its anatomy is not fully understood.

OBJECTIVES

The aim of this study was to elucidate the three-dimensional PN-PV structure.

METHODS

Organ-surface PVS tissue was isolated from healthy and anemic rats. The tissues were analyzed by X-ray microcomputed tomography (CT), hematoxylin and eosin staining, and scanning electron microscopy.

RESULTS

From CT images, we identified one or more bundles in a PV. In the PN, the bundles were enlarged and existed in isolation and/or in anastomosis. The transverse CT images revealed four areas of distinct intensities: zero, low, intermediate, and high. The first two were considered to be the sinuses and the subvessels of the PVS and were identified in the hematoxylin and eosin-stained PN sections. The enlargement of the PN from anemic rats was associated with an increase in the intermediate-intensity area. The high-intensity area demarcated the bundle and was overlapped with the mesothelial cells. In scanning electron microscopy, the PV bundles branched out, tapering down to a single bundle at some distance from the PN. Each bundle was composed of several subvessels (∼5 μm). Clustered round microcells (1-25 μm), scattered flat oval cells (∼15 μm), and amorphous extracellular matrix were observed on the surface of the PVS tissue.

CONCLUSIONS

The results newly showed that the primo bundle is a structural unit of both PVs and PNs. A bundle was demarcated by high CT intensity and mesothelial cells and consisted of multiple subvessels. The PN bundles contained also sinuses.

Acute Anemia Induces Erythropoiesis in Rat Organ Surface Primo-Vascular Tissue

The primo-vascular system (PVS) is a newly identified vascular tissue composed of primo-nodes (PNs) and primo-vessels (PVs). Previously, we reported erythropoietic activity in the organ-surface PVS (osPVS) tissue of rats with heart failure. In this study, we further investigated whether acute anemia could induce erythropoiesis in the PVS of rats, based on the hypothesis that erythropoiesis in osPVS tissue is due to anemia accompanying heart failure. Acute anemia was induced by an intraperitoneal injection of phenylhydrazine (PHZ). Circulating red blood cells (RBCs) and hematocrit decreased by 31.6%, whereas reticulocytes and white blood cells increased at day 3 and day 6 after PHZ treatment. All these parameters recovered to control levels at day 10. At days 3 and 6, we observed an increase in the size of the PNs (P < 0.05), the number of the osPVS tissue samples per rat (P < 0.01), and the proportion of osPVS tissue samples with red chromophore (P < 0.001), which was from the RBCs in the PVS tissue. The number of RBCs, estimated from the PN sections stained with hematoxylin and eosin, increased at day 6 in the rats with anemia (P < 0.01). All these anemia-induced changes in the osPVS tissue recovered to the control levels by day 10. Taken together, the results showed that the morphological and cytological changes in the osPVS tissue appear to be related to the erythropoietic activity induced by acute anemia in rats. This study confirmed the previous findings that the osPVS can exert erythropoietic activity in disease states accompanied by anemia, such as heart failure.

Mesothelial Cells Covering the Surface of Primo Vascular System Tissue

The primo vascular system (PVS) is reported to have a periductium composed of cells with spherical or spindle-shaped nuclei and abundant cytoplasm. However, little is known about these periductium cells. In this study, we examined the morphological features of cells covering the PVS tissue isolated from the surface of abdominal organs of rats. By hematoxylin and eosin (H&E) staining, we observed a layer of dark nuclei on the basement membrane at the borders of the sections of primo node (PN), primo vessel (PV), and their subunits. The nuclei appeared thin and linear (10-14 μm), elliptical (8-10 × 3-4 μm), and round (5-7 μm). The borders of the PVS tissue sections were immunostained with a selective antibody for mesothelial cells (MCs). Areas of immunoreactivity overlapped with the flattened cells are shown by hematoxylin and eosin staining. By scanning electron microscopy, we further identified elliptical (11 × 21 μm) and rectangular squamous MCs (length, 10 μm). There were numerous stomata (∼200 nm) and microparticles (20-200 nm) on the surface of the PVS MCs. In conclusion, this study presents the novel finding that the PVS periductium is composed of squamous MCs. These cells tightly line the luminal surface of the PVS tissue, including PNs, PVs, and small branches of the PVs in the abdominal cavity. These results will help us to understand the physiological roles such as hyaluronan secretion and the fine structure of PVS tissue.

Chronological Review on Scientific Findings of Bonghan System and Primo Vascular System

In 1962, Bonghan Kim in North Korea published a report on a new vascular system in mammals, which he claimed as the acupuncture meridian. He soon named it the Bonghan System. Between 1962 and 1965, he published five reports, with detailed descriptions on the system. Kim also described the self-regenerating nature of a unique cell type Sanals in the system and these cells are now confirmed to be a type of stem cells. According to his findings, the system appears to have vital roles in maintaining mammalian lives. Kim disappeared in around 1965 and the research on this system also completely stopped. In 2002, Kwang-Sup Soh reported re-discovery of the system and, since then, his team has been leading the research on the system. The Soh team has confirmed many of Kim's findings to be valid, although so many of Kim's results are still to be verified. In 2010, the system was renamed the Primo Vascular System (PVS). Soh and researchers trained by Soh have also been reporting new scientific facts on the system. The PVS exists throughout the entire body, including inside the blood and lymphatic vessels. Recent reports revealed more evidence for it to be the acupuncture meridian, where some acupuncture therapies are applied for the blood pressure control. Thus, the PVS is expected to have roles in the oxygen transport in tissues. Many study results also suggest that the PVS may have roles in body homeostasis and regeneration. This article chronologically reviews Kim's scientific findings on the Bonghan System, which were verified by the PVS scientists (after 2000), and also the new findings reported by the PVS scientists.

Observation of a Flowing Duct in the Abdominal Wall by Using Nanoparticles

The primo vascular system (PVS) is being established as a circulatory system that corresponds to acupuncture meridians. There have been two critical questions in making the PVS accepted as a novel liquid flowing system. The first one was directly to show the flow of liquid in PVS and the second one was to explain why it was not observed in the conventional histological study of animal tissues. Flow in the PVS in the abdominal cavity was previously verified by injecting Alcian blue into a primo node. However, the tracing of the dye to other subsystems of the PVS has not been done. In the current work we injected fluorescent nanoparticles (FNPs) into a primo node and traced them along a primo vessel which was inside a fat tissue in the abdominal wall. Linea alba is a white middle line in the abdominal skin of a mammal and a band of fat tissue is located in parallel to the linea alba in the parietal side of the abdominal wall of a rat. In this fat band a primo vessel runs parallel to the prominent blood vessels in the fat band and is located just inside the parietal peritoneum. About the second question on the reason why the PVS was not in conventional histological study the current work provided the answer. Histological analysis with hematoxyline and eosine, Masson’s trichrome, and Toluidine blue could not discriminate the primo vessel even when we knew the location of the PVS by the trace of the FNPs. This clearly explains why the PVS is hard to observe in conventional histology: it is not a matter of resolution but the contrast. The PVS has very similar structure to the connective tissues that surround the PVS. In the current work we propose a method to find the PVS: Observation of mast cell distribution with toluidine blue staining and the PN has a high density of mast cells, while the lymph node has low density.

Exploration of differentiation standard for primo through the histological common point of threadlike structure found in rats and swine

BACKGROUND

The novel threadlike structure is called the primo structure, and studies are conducted through many different approaches. Although various ways of differentiation are currently used, a standard for differentiation is deemed necessary in order to identify the primo structure based on the overall form of the structure. This study aims to explore the differentiation standard through the histological common point of the threadlike structure of rat and swine by using the hematoxylin and eosin (H&E) staining method commonly used for histological research in various structures.

METHODS

An 8-week old Sprague-Dawley rat and a Yorkshire pig weighing 30-40 kg were used. A total of 65 pieces of rat threadlike structure and 100 pieces of swine threadlike structure were collected after the abdomen was cut and opened. The following three different characteristics were confirmed using the H&E staining method for the collected structures: (1) bright cell availability; (2) cavity availability; and (3) nuclei density.

RESULTS

For the rat threadlike structure, the bright cell (70.5%) and nuclei density (92.6%) were mainly observed; in the swine threadlike structure, however, the bright cell (60.6%) and cavity (67.2%) were mainly observed. The bright cell was confirmed to have been observed in the threadlike structures of both rat and swine.

CONCLUSION

The bright cell is determined to be the common point in the primo structure. However, further research is deemed necessary in the future as to the functions performed by the characteristic shown by the Primo structure.

A Hyaluronic Acid-Rich Node and Duct System in Which Pluripotent Adult Stem Cells Circulate

Regenerative medicine is in demand of adult pluripotent stem cells (PSCs). The "Bonghan System (BHS)" was discovered and suggested to contain cells with regenerative capacity in the early 1960s. It had been ignored for a long time due to the lack of sufficient details of experiments, but about 37 years after the initial report, the BHS was rediscovered and named as the "primo vascular system." Recently, we have discovered a similar structure, which contained a high level of hyaluronic acid, and hence, named the structure as hyaluronic acid-rich node and duct system (HAR-NDS). Here we discuss the HAR-NDS concept starting from the discovery of BHS, and findings pointing to its importance in regenerative medicine. This HAR-NDS contained adult PSCs, called node and duct stem cells (NDSCs), which appeared to circulate in it. We describe the evidence that NDSCs can differentiate into hemangioblasts that further produced differentiated blood cells. The NDSCs had a potential to differentiate into neuronal cells and hepatocytes; thus, NDSCs had a capability to become cells from all three germ layers. This system appears to be a promising alternative source of adult stem cells that can be easily delivered to their target tissues and participate in tissue regeneration.

Identification of Primo-Vascular System in Abdominal Subcutaneous Tissue Layer of Rats

The primo-vascular system (PVS) is a novel network identified in various animal tissues. However, the PVS in subcutaneous tissue has not been well identified. Here, we examined the putative PVS on the surface of abdominal subcutaneous tissue in rats. Hemacolor staining revealed dark blue threadlike structures consisting of nodes and vessels, which were frequently observed bundled with blood vessels. The structure was filled with various immune cells including mast cells and WBCs. In the structure, there were inner spaces (20–60 µm) with low cellularity. Electron microscopy revealed a bundle structure and typical cytology common with the well-established organ surface PVS, which were different from those of the lymphatic vessel. Among several subcutaneous (sc) PVS tissues identified on the rat abdominal space, the most outstanding was the scPVS aligned along the ventral midline. The distribution pattern of nodes and vessels in the scPVS closely resembled that of the conception vessel meridian and its acupoints. In conclusion, our results newly revealed that the PVS is present in the abdominal subcutaneous tissue layer and indicate that the scPVS tissues are closely correlated with acupuncture meridians. Our findings will help to characterize the PVS in the other superficial tissues and its physiological roles.

Hypothesis on the Treatment of Gliomas with Acupuncture at the Primo Node Corresponding to Zusanli (ST 36)

Background: The primo vascular system (PVS) is an anatomical structure that is a network of ducts with fluid flowing in them, which are called primo vessels and correspond to acupuncture meridians, and primo nodes that correspond to acupoints. The PVS' main function is considered to be the maintenance of regenerative homeostasis in human and animal bodies. This system is distributed throughout the bodies of normal animals and develops around and in cancer tissues. This cancer-associated PVS may be a critical metastatic path besides the blood and the lymph vessels. The author of this article proposes a hypothesis on cancer treatment: Injecting anticancer drugs into acupoints according to the pharmacopuncture method can be effective as a result of the flow channels of the PVS. The author considers the acupoint Zusanli (ST 36) and the route of the primo vessels starting from it. This specific PVS route runs along the perineurium of the sciatic nerve, the pia mater, and the arachnoid mater of the spinal cord to the brain. Thus, by injecting a suitable anticancer drug into ST 36, one can deliver the drug into the brain to treat gliomas and other brain tumors. This new drug-delivery method is just one of the new clinical applications that are possible by combining acupuncture and using the PVS. Conclusions: Anticancer drugs for glioma can be injected into the primo node at the acupoint ST 36 to reach the cancer tissue through the PVS in the sciatic nerve, spine, and brain that can avoid the blood-brain barrier.