Donor-derived DNA in hair follicles of recipients after allogeneic hematopoietic stem cell transplantation.

The hair follicles of recipients of allogeneic hematopoietic SCT (HSCT) constitute the tissue with the greatest need for regeneration after high-dose chemotherapy. Previous studies have shown a lack of donor-derived DNA in the hair follicles of recipients. Therefore, we carried out a study to determine whether male donor-derived genetic material can be found in female recipients' hair follicles after HSCT. Fluorescent-based PCR with analyses of Y-chromosome STR (Y-STR) and RQ-PCR with the sex-determining region Y (SRY) were used independently to evaluate chimerism status. Our results proved the existence of donor-derived stem DNA in the recipients' hair follicle cells. This report undermines the validity of data indicating that hair follicle cells maintain 100% of recipient origin.

Assessment of potassium and sodium ion concentrations in the vitreous humour of swine isolated eyeballs after organism death.

Potassium and sodium ion concentrations were estimated by the flame photometry and potentiometry in the vitreous fluid of isolated porcine eyeballs at time of death and of eyeballs, stored at temperature of 6-8 degrees C during post-mortem intervals: 4, 28, 52, 75, 100, 124 and 148 hours. The increase of K+ concentration and decrease of Na+ concentration were proportional to the increasing post-mortem time intervals. The results of the potentiometric measurements of K+ and sodium ion concentrations were significantly lower, as compared to those after flame photometry. In all the vitreous fluid smears after 124 and 148 hours, gram (-) bacteria were found. Our results suggest that bacterial infection participates in the variability of K+ levels. The influence of bacterial infection on the margin of error for the K+ post-mortem test remains unanswered and needs further studies.

The assessment of post mortem structural changes in the human epidermis.

The structure of epidermis and appearance of keratinocytes is described in intact skin specimens from human corpses stored after death under refrigeration. Two groups of alterations can be identified depending on the epidermal layer. In the spinous layer, the cells are characterized by crescent-shaped nuclei surrounded by a hollow area. The number of such cells increases significantly each day during the first 8 days post mortem (dpm), and their frequencies follow respective regression equations, so as to enable the post mortem time estimation with one day accuracy. In the basal layer, distorted, balloon-shaped cells with pycnotic nuclei appear, which with the lapse of time are forming groups, and eventually the epidermis in those places separates from the dermis. The presence of both described changes seems to indicate whether the skin sample was obtained from the living organism or after the death.

Topographical and quantitative post mortem assessment of the rat skin mast cells.

Rat skin mast cell (MC) number and density change due to the postmortem storage of the material at 6-8 degrees C during a 19-day period. Both the number and the density of the MC in the 200 microm thick subepidermal layer decreased with the square of the time (p > or = 0.99). The count and the density may be used interchangeably in topographic studies of the rat MC.

The assessment of post mortem PCNA+ cell frequency in the rat epidermis.

PCNA-positive nuclei (nPCNA+) in the basal layer of rat epidermis were assessed in the period of 0-19 days after death. The PCNA+ nuclei were present in this layer up to 12th day. The decrease in PCNA+ nuclei ratio was highly correlated with the time and followed the equation y = a + b square root(x) (y = nPCNA fraction, x = time post mortem).