Primo-Vascular System as Presented by Bong Han Kim

In the 1960s Bong Han Kim discovered and characterized a new vascular system. He was able to differentiate it clearly from vascular blood and lymph systems by the use of a variety of methods, which were available to him in the mid-20th century. He gave detailed characterization of the system and created comprehensive diagrams and photographs in his publications. He demonstrated that this system is composed of nodes and vessels, and it was responsible for tissue regeneration. However, he did not disclose in detail his methods. Consequently, his results are relatively obscure from the vantage point of contemporary scientists. The stains that Kim used had been perfected and had been in use for more than 100 years. Therefore, the names of the stains were directed to the explicit protocols for the usage with the particular cells or molecules. Traditionally, it was not normally necessary to describe the method used unless it is significantly deviated from the original method. In this present work, we have been able to disclose staining methods used by Kim

Hemmule: A Novel Structure with the Properties of the Stem Cell Niche

Stem cells are nurtured and regulated by a specialized microenvironment known as stem cell niche. While the functions of the niches are well defined, their structure and location remain unclear. We have identified, in rat bone marrow, the seat of hematopoietic stem cells—extensively vascularized node-like compartments that fit the requirements for stem cell niche and that we called hemmules. Hemmules are round or oval structures of about one millimeter in diameter that are surrounded by a fine capsule, have afferent and efferent vessels, are filled with the extracellular matrix and mesenchymal, hematopoietic, endothelial stem cells, and contain cells of the megakaryocyte family, which are known for homeostatic quiescence and contribution to the bone marrow environment. We propose that hemmules are the long sought hematopoietic stem cell niches and that they are prototypical of stem cell niches in other organs

PEGylation of zinc nanoparticles amplifies their ability to enhance olfactory responses to odorant.

Olfactory responses are intensely enhanced with the addition of endogenous and engineered primarily-elemental small zinc nanoparticles (NPs). With aging, oxidation of these Zn nanoparticles eliminated the observed enhancement. The design of a polyethylene glycol coating to meet storage requirements of engineered zinc nanoparticles is evaluated to achieve maximal olfactory benefit. The zinc nanoparticles were covered with 1000 g/mol or 400 g/mol molecular weight polyethylene glycol (PEG). Non-PEGylated and PEGylated zinc nanoparticles were tested by electroolfactogram with isolated rat olfactory epithelium and odorant responses evoked by the mixture of eugenol, ethyl butyrate and (±) carvone after storage at 278 K (5 oC), 303 K (30 oC) and 323 K (50 oC). The particles were analyzed by atomic force microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, and laser Doppler velocimetry. Our data indicate that stored ZnPEG400 nanoparticles maintain physiologically-consistent olfactory enhancement for over 300 days. These engineered Nanoparticles support future applications in olfactory research, sensitive detection, and medicine

Properties of PEG on the surface of zinc nanoparticles.

<p>Properties of PEG on the surface of zinc nanoparticles.</p

Representative EOG recordings from rat olfactory epithelium.

<p>a The stimuli were of 0.25 s pulses of (1) odorant mixture, (2) odorant mixture +1.2 nm zinc nanoparticles, (3) odorant mixture + 0.25 mmole/L PEG400, (4) odorant mixture + 0.10 mmole/L PEG1000, (5) water vapor + PEG400, (6) water vapor + PEG1000, and (7) water vapor. The concentration of zinc nanoparticles and odorant mixture were 0.02 nmole/L and 1.6 mmole/L, respectively. The representative set of traces was obtained from 50 EOG traces.</p

The relative EOG signals as a function of time of storage of zinc nanoparticles.

<p>The difference between peak values of EOG evoked by odorant and by non-PEGylated and PEGylated zinc nanoparticles was normalized by the EOG peak evoked by an odorant alone. The relative enhancement by zinc nanoparticles was calculated as described in Materials and methods.</p

Physical properties of non-PEGylated and PEGylated zinc nanoparticles.

<p>(a) AFM images, and (b) histograms showing the size distribution of the nanoparticles. A: Zinc nanoparticles, B: ZnPEG400, C: ZnPEG1000.</p

Thermodynamic analysis of oxidation of Zn, ZnPEG400, and ZnPEG1000 nanoparticles.

<p>Thermodynamic analysis of oxidation of Zn, ZnPEG400, and ZnPEG1000 nanoparticles.</p