In cellular, tissue-level or whole organ bioreactors, the level of dissolved oxygen is one of the most important factors requiring control. Hypoxic environments may lead to cellular apoptosis, while hyperoxic environments may lead to cellular damage or dedifferentiation, both resulting in loss of overall tissue function. This manuscript describes the creation, characterization and validation of...

The terminal respiratory units of the gas exchange tissue of the avian lung, the air capillaries (ACs) and the blood capillaries (BCs), are small and rigid: the basis of this mechanical feature has been highly contentious. Because the strength of the blood-gas barrier (BGB) of the mammalian lung has been attributed to the presence of type-IV collagen (T-IVc), localization of T-IVc in the baseme...

In this paper, analysis of free nucleotides from mouseliver tissue during different day times has been described. Perchloric acid extract of mouse liver tissue was neutralized with tri-N-octylamine in trichlorotriflouroethane and after removal of ClO4(-), subjected to preliminary purification on a Cu(2+)-loaded column of Chelex 100. A high-pressure liquid chromatographic (HPLC) anion-exchange p...

Branched networks are ubiquitous throughout nature, particularly found in tissues that require large surface area within a restricted volume. Many tissues with a branched architecture, such as the vasculature, kidney, mammary gland, lung and nervous system, function to exchange fluids, gases and information throughout the body of an organism. The generation of branched tissues requires regulati...

Various authors (1, 2, 3, 9) have reported that tritiated water as applied to plant roots does not fully exchange with water of various aerial organs, particularly leaves, even after long period of observation. This incomplete equality between tritium concentration in tissue water and external sources has been attributed to an inaccessible component of tissue water which does not exchange (2). ...

A mathematical analysis of a model for nutritional exchange in a capillary-tissue exchange system is presented in this paper. This model consists of a single file flow of red blood cell in capillary when diameter of red blood cell is greater than tube diameter. In this case, the cell must be deformed. Due to concentration gradients, the dissolved nutrient in substrate diffuses into surrounding ...

Heterochronic parabiosis rejuvenates the performance of old tissue stem cells at some expense to the young, but whether this is through shared circulation or shared organs is unclear. Here we show that heterochronic blood exchange between young and old mice without sharing other organs, affects tissues within a few days, and leads to different outcomes than heterochronic parabiosis. Investigati...

The placenta provides for exchange of nutrients, oxygen and waste products between the mother and fetus, as well as being an endocrine organ for the synthesis of hormones and neurotransmitters and a barrier to toxins and infection. It is derived from both maternal and fetal tissue, with approximately one fifth derived from fetal tissue at term. It comprises a large number of functional units ca...

Thrombotic thrombocytopenic purpura (TTP) is a rare complication of connective tissue diseases. Here, we describe 2 patients with mixed connective tissue disease (MCTD) who had pericardial effusion and TTP. They had moderately low to normal ADAMTS13 activity and no ADAMTS13 neutralizing antibodies. Both patients responded poorly to plasma exchange. One patient died due to multiple organ failure...

background and aims. connective tissue grafts with and without periosteum is used in regenerative treatments of bone and has demonstrated successful outcomes in previous investigations. the aim of present study was to evaluate the effectiveness of connective tissue graft with and without periosteum in regeneration of intrabony defects. materials and methods. in this single-blind randomized spli...