Keratinocytes derived from embryonic stem cells induce wound healing in mice.

The skin plays an important role in defending the body against the environment. Treatments for burns and skin injuries that use autologous or allogenic skin grafts derived from adult or embryonic stem cells are promising. Embryonic stem cells are candidates for regenerative and reparative medicine. We investigated the utility of keratinocyte-like cells, which are differentiated from mouse embryonic stem cells, for wound healing using a mouse surgical wound model. Mice were allocated to the following groups: experimental, in which dressing and differentiated cells were applied after the surgical wound was created; control, in which only the surgical wound was created; sham, in which only the dressing was applied after the surgical wound was created; and untreated animal controls with healthy skin. Biopsies were taken from each group on days 3, 5 and 7 after cell transfer. Samples were fixed in formalin, then stained with Masson's trichrome and primary antibodies to interleukin-8 (IL-8), fibroblast growth factor-2 (FGF-2), monocyte chemoattractant protein-1 (MCP-1), collagen-1 and epidermal growth factor (EGF) using the indirect immunoperoxidase technique for light microscopy. Wound healing was faster in the experimental group compared to the sham and control groups. The experimental group exhibited increased expression of IL-8, FGF-2 and MCP-1 during early stages of wound healing (inflammation) and collagen-1 and EGF expression during late stages of wound healing (proliferation and remodeling). Keratinocytes derived from embryonic stem cells improved wound healing and influenced the wound healing stages.

Calcitonin expression of high endothelial venules during lymphocyte migration in human pharyngeal tonsil.

The migration routes of lymphocytes through high endothelial venules (HEVs) of control and hypertrophic pharyngeal tonsil (HPT) tissue sections were investigated by immunohistochemistry using the expression of a hormone [calcitonin (CT)] and two calcium-dependent endothelial adhesion molecules (E-selectin and P-selectin), as well as electron microscopy. A marked increase in CT-specific staining was observed in the endothelial cells of HEV in the HPT group compared to the control group. Expressions of E-selectin and P-selectin on HEVs of control group were faint, when compared to the strong expression of these selectins on HEVs of HPT. Electron microscopically, we demonstrated that lymphocytes transmigrated through HEV and observed the close membranous contact between endothelial cells and lymphocytes during this process. We speculate that increasing CT during inflammation may be important for lymphocyte migration through the HEVs via controlling the expression of E-selectin and P-selectin.

Paratracheal extramedullary hematopoiesis.

Extramedullary hematopoiesis (EMH) is a rare finding in hematology. A 73-year-old female patient with a 1-week history of severe progressive dyspnea was examined, and computed tomography (CT) showed a paratracheal mass 3 cm in size located 1 cm below the vocals cords and causing obliteration of the tracheal airway. Cytology of a needle biopsy revealed EMH. External radiotherapy of 200-cGy fractions to a total dose of 2000 cGy was administered with 3-dimensional conformal planning to treat the progressive symptoms. The patient's clinical symptoms started to improve 2 days after radiotherapy and had completely disappeared after 7 days. CT scans showed complete response on follow-up at 1 week to 5 months after radiotherapy. Mature and immature hematopoietic cells and many adipose cells were seen in the pretreatment samples. Histologic findings in the posttreatment samples showed that these cells had completely disappeared due to the conformal radiotherapy. On the basis of clinical, radiologic, and histologic results, we suggest that conformal radiotherapy may be useful for the treatment of paratracheal localization of EMH because good tumoral irradiation was obtained in this case, with the protection of normal tissues.

The effect of thyrotropin releasing hormone on carbon dioxide laser induced lesion of the cerebral artery.

Carbon dioxide laser which is used widely in neurosurgery has less traumatic effect on the tissue beside the lesion than other types of laser. There has been little study on the changes to the vascular tissue, following laser application. We performed a study on 4 groups of dogs; comprising craniectomy only, craniectomy and thyrotropin releasing hormone (TRH), craniectomy and laser, and craniectomy, laser and TRH. We applied CO2 laser on the angular artery of two groups of dogs. To one group we infused TRH for 15 days following the laser application and to the other group we did not. We investigated the ultrastructural and biochemical changes and the effect of TRH on the tissue 15 days following laser application. In our study, we observed an increase in superoxide dismutase activity and a decrease in ATP-ase activities in the degenerated tissue on which CO2 laser was applied. TRH partially prevented the vascular degeneration of CO2 laser but did not significantly change superoxide dismutase and Adenosine-5'-triphosphatase activities.

The effect of toluene on the rat ovary: an ultrastructural study.

In this study, eighteen Wistar female albino rats were used to observe the ultrastructural effects of toluene on the rat ovaries. The animals were divided into experimental and control groups. The experimental group was exposed to 3,000 ppm toluene/m3 for 7 days and 8 h/day. At the end of the experiment the main ultrastructural findings related to the oocytes of the antral follicles of the experimental group were: abundant vacuoles, lytic areas, degenerative mitochondria in the ooplasm and blunt microvilli on the surface. Furthermore, the granulosa cells revealed prominent degenerative changes such as pyknotic nuclei, mitochondrial alterations and dilatation of the endoplasmic reticulum (ER) cisternae. It was interesting to note tht the ultrastructure of primordial follicles was almost similar in both experimental and control groups. All these findings suggested that, although toluene did not affect the primordial follicles, the growing follicles showed degenerative changes attributable to the inhalation of a toxic agent such as toluene.

Electron microscopy of psoriatic skin before and after psoralen/ultraviolet A treatment.

Skin biopsy specimens of patients with psoriasis receiving psoralen/ultraviolet A treatment were examined. A decrease in tonofilaments and keratohyaline granules and enlarged intercellular spaces were common findings in all cases. Hyperchromatic nuclei in the horny cells and hyperactive keratinocytes in the malpighian layer were also observed. Treatment resulted in normalization of keratinocytes and stimulation of melanocytes. Our study revealed that psoralen/ultraviolet A is effective and important in the treatment of psoriasis, but patients should be evaluated for atypical changes.

Alport's syndrome with bilateral macular hole.

In this study 8 patients with Alport's syndrome are presented. The ocular manifestations of these patients were retinal flecks, macular depigmentation, microspherophakia and anterior lenticonus. One patient revealed bilateral macular hole which was an unusual feature. Four patients had renal biopsies with the characteristic electron microscopic changes of the disease. According to these findings our conclusion is that Alport's syndrome is a disorder of selected basement membranes.

Early clinical and ultrastructural effects of diltiazem injection on rabbit extraocular muscles.

We injected diltiazem into the left lateral rectus muscles (LR) of 10 rabbits in order to examine the ultrastructural effects of diltiazem on rabbit extraocular muscles and estimate its advantages in clinical use as an alternative to the surgical therapy of strabismus. The animals were divided into two groups according to the time of evaluation following the injection. The LR muscles of both eyes of the first group were respected 60 min after the injection, for ultrastructural examination. The same procedure was done for the second group at the 24th hour. The right eyes were used as the control group. There was a medial shift 3-5 min following the injection in the left eyes of both groups. The ultrastructural examination revealed weakness in muscle contractility, probably as a result of inhibition of glycogen usage due to calcium accumulation. In this study, we examined the early clinical and ultrastructural effects of diltiazem.