Donor cells

Alloimmunity is the immune response mounted by a host on the basis of differences in major histocompatibility antigens expressed on the surface of a donor cell from the same species as the host. 

The use of protoplasts in studies of stress physiology and biochemistry expands the advantages of cell culture systems discussed in the preceding sections. Additional applications are related to the fusion of protoplasts. Intraspecifie and interspecific protoplast fusion greatly enhance genetic variability of the fused protoplasts (Kumar Cocking, 1987). The resulting somatic hybrids provide cells which can be used for selection of specific traits (e.g. environmental stress tolerance) provided by one or both donor cells and for basic studies on cytoplasmic and nuclear inheritance of desired characteristics. 

Figure 2.1 Transport model diagram, depicting two aqueous cells separated by a membrane barrier. The drug molecules are introduced in the donor cell. The concentration gradient in the membrane drives the molecules in the direction of the acceptor compartment. The apparent partition coefficient, Kd = 2. [Avdeef, A., Curr. Topics Med. Chem., 1, 277-351 (2001). Reproduced with permission from Bentham Science Publishers, Ltd.]...

Garrett and Chemburkar [15] described a membrane device which provides for steady-state conditions by continuously circulating fresh donor solution into the donor cell. 

Pollen allelopathy is phenomenon when pollen chemicals (e.g., phenols, terpenoids, sesquiterpene lactones, etc.) inhibit sexual reproduction in heterospecific individuals due to influencing of fertilization (Murphy 1992). The phenomenon includes excretion of signaling compounds from the donor cell (pollens, pistil stigma), recognition of a specific signal, transmission of information (pollen), and the development of a characteristic response in the acceptor cell. The possible mechanism of the effect was described in Roshchina (2001). 

Diffusion studies were performed by using a Valia-Chen diffusion cell (Crown Glass Co., Inc., Somerville, NJ). The apparatus consisted of two half-cells, receptor cell and donor cell, with a volume of 3 mL and a side opening with a diameter of 9 mm. A magnetic stir bar was placed in each half-cell for continued agitation. Between the two half-cells a preswollen membrane was securely placed and was protected from the atmosphere to prevent evaporation of the solvent form the membrane. 

To the donor cell, 3 mL of the model drug solution was added, and to the receptor half-cell 3 mL of the solvent was added. Timing of the diffusion of the solute began as soon as both half-cells were filled. At regular intervals (i.e., 15, 30, and 60 minutes) the contents of the receptor cell were moved and replaced with fresh solvent, which in this case was pH buffer solution. To ensure constant temperature of the iimer cell solution, constant-temperature water was pumped through the outer half-cells. 

Here, Q is the solute concentration in the receptor cell at time t Q is the initial solute concentration of the donor cell V is volume of each half-cell A is the effective area of permeation and P is the membrane permeability coefficient. To determine the permeability coefficient, P a plot of — (V72A) In [1 — 2(Cf/CJ] versus time, was constructed. The linear portion yields a slope of the permeability coefficient, P in cm/s. 

The current studies were conducted in rodents with I/R ARE, an extensively investigated, albeit imperfect model of the most common and the most treatment-resistant type of clinical AKI. Morigi et al. (Morigi et al, 2004), using rodents with cisplatinum-induced ARE, showed that administration of MSC improved renal function, and MSC appeared to directly contribute to the reconstitution of renal epithelium by transdifferentiation. However, these investigators did not demonstrate that the observed transdifferentiation of MSC is the actual mechanism of renoprotection, and they presented no data regarding the actual numbers of donor cells that undertook the tubular repair. It may be... 

The in vitro diffusion studies for each sample were carried out by using the Franz diffusion cells with a diffusional area of about 1.76cm2. The acceptor compartment of the apparatus was filled with the buffer solution pH 6, USP [21], and maintained at 37 0.5°C via a circulating water system. The diffusion membrane (the cellulose membrane with a molecular weight cut-off point of 1000 or the hairless mouse skin) previously prepared was placed between die donor and the acceptor compartments of the assembly. An accurately weighed 4g of sample was then placed in the donor cell and the diffusion process was started. The solution in the acceptor compartment was continuously stirred with a small magnetic stirrer to maintain the sink conditions. Aliquots from the receptor cells were removed at 0.5,2,4, 8 and 24 h time intervals and replaced with equal... 

There are, however, several limitations and contraindications with MSC therapy. One of the limitations is in the establishment of MSC cultures from donors, parents or siblings. Although MSC can be readily isolated and expanded in vitro, establishing the MSC cultures can be a limiting factor. Failure to establish such cell cultures in a timely manner, and in sufficient qualities and quantities, may have profound consequences on the therapy. Since MHC compatibility is not necessary for MSC immunosuppression, and because MSC immunomodulatory activity can also be observed in third-party donor cells [656550], MSCs derived from unrelated, -unmatched, healthy, third-party donors would represent a universal donor MSC product with the advantage of being a readily-available product that may provide an opportunity for multiple and higher MSC doses, potentially at a reduced cost [659019 ]. 

When an Hfr strain conjugates with an F (female), replication of the entire male chromosome commences at some point near the end of the integrated F agent, and genes of the bacterial chromosome followed by those of the F factor are transferred into the female. Only a single strand of DNA (customarily referred to as the plus strand) is transferred from the donor cell and into the recipient cell (Fig. 26-3). There the complementary minus strand is synthesized to form a complete double-stranded DNA molecule bearing the genes from the Hfr cell. Only rarely does a copy of the entire chromosome of the donor cell enter the female cell. More often the DNA strand, or perhaps the pilus itself, breaks and only part of the chromosome is transferred. 

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