Influence of antlerogenic stem cells on the healing of lesions in the corneal epithelium and corneal stroma in rabbits.

The aim of the study was to compare the effects of corneal healing in case of application of stem cells in various forms, in relation to the antibiotic-assisted procedures. Rabbits were divided into 4 groups in the first stage of the experiment. Group 0 (negative control group) was not subjected to any actions, which would cause damage to the cornea. The remaining three groups had their cornea damaged. Group 1 (positive control group) - no drugs were administered during the experiment. Rabbits in group 2 were administered with ointment containing stem cells to the lesion, while group 3 - with ofloxacinum. The stem cells were administered during the first five days, twice a day, onto the corneal surface. The further course of the experiment consisted of observing the rate of healing of the injured cornea and assessment of its transparency, size of lesion, hyperaemia, eyelid spasm and outflow from the conjunctival sac after 5, 10 and 20 days.In the second stage the animals were euthanised after clinical examination on the twentieth day of the experiment, in order to analyse the corneal reparative processes on the same day. The studies revealed that the application of antlerogenic stem cells had a positive effect on the healing process of corneal defects. The application thereof not only shortened the healing time, but also weakened or arrested the development of side effects. The results have demonstrated that the epithelial proliferation in each group was different. The longest was maintained in the group with stem cells, the shortest - in the group with chemotherapeutics. The use of antlerogenic stem cells had a positive effect on the healing process of corneal lesions. The use of stem cells helped to maintain high transparency of the cornea.

Computed Tomography of the Prostate Gland in Healthy Intact Dogs and Dogs with Benign Prostatic Hyperplasia.

To date, there is only scarce data on the evaluation of the prostate gland in dogs using computed tomography (CT). The aims of our study were to describe CT features of BPH in dogs and to determine the size of the prostate gland in healthy male dogs and dogs with benign prostatic hyperplasia (BPH) through CT. Additionally, we aimed to compare and establish the most useful parameters for CT measurements of the prostate in patients with BPH. The study population consisted of 20 healthy intact male dogs and 20 male intact dogs with confirmed BPH. Pre- and post-contrast CT studies were evaluated. The most common CT features in dogs with recognized BPH were symmetrical prostatomegaly and heterogeneity of the prostatic parenchyma. The mean prostatic density (D) was 56HU (±4.39) in pre-contrast CT images and 84HU (±8) in post-contrast images in dogs with BPH. The mean prostatic length (L) was 43.87 mm (±11), the mean width (W) amounted to 48.95 mm (±8.76) and the mean height (H) reached 44.9 mm (±9.48) in clinically affected patients. The mean ratios were: rL - 2,12 (±0.5); rW - 2.39 (±0.53) and rH - 2.16 (±0.39) in the BPH group. The prostate should be considered to be enlarged when rL exceeds 3.05; rW exceeds 3.38 and rH exceeds 2.94. Our findings indicated that CT is a useful tool in diagnosing prostate disorders, including BPH. The heterogeneity, density and ratios of prostatic length, width and height can be useful parameters in the diagnosis of BPH.

Requirement for an intact cytoskeleton for volume regulation in boar spermatozoa.

Osmotically induced cell swelling triggers a chain of events leading to a net loss of major cell ions and water, resulting in cell volume recovery, a process known as regulatory volume decrease (RVD). In many cell types, there is an evidence that the cytoskeleton may play a role in the initial sensing and transduction of the signal of volume change. In this study, we tested the hypothesis that an intact microfilament and microtubule network is required for volume response and RVD in boar sperm before and after capacitation treatment and whether addition of cytochalasin D and colchicine to the capacitation medium would affect volumetric behaviour. Capacitation is a series of cellular and molecular alterations that enable the spermatozoon to fertilize an oocyte. Cell volume measurements of washed sperm suspensions were performed electronically in Hepes-buffered saline solutions of 300 and 180 mosmol/kg. After exposure to hypoosmotic conditions, boar sperm showed initial swelling (up to 150% of initial volume within 5 min), which was subsequently partially reversed (to about 120-130% after 20 min). Treatment with cytochalasin D led to reduced initial swelling (1 micromol/l) and loss of RVD in washed sperm (1-10 micromol/l) and at the beginning of incubation under capacitating conditions (5 micromol/l). Short treatment with 500 micromol/l colchicine affected the volume regulatory ability in sperm under capacitating conditions but not in washed sperm. No significant differences in cell volume response were observed after subsequent addition of cytochalasin D and colchicine to the suspensions of sperm incubated for 3 h under capacitating conditions. However, the incubation under capacitating conditions in the presence of cytochalasin D led to improved volume regulation at the end of the incubation period (23%). The microfilament network appears to be important for volume regulation in washed boar spermatozoa while intact microtubules do not seem to be necessary for osmotically induced RVD. The changes in cytoskeleton microfilament organization during capacitation, possibly affecting the osmotically induced volume response, appear to occur at the later stages of capacitation, whereas changes in microtubules, related to volume regulatory ability, may be programmed within the first stages of capacitation.

Role of quinine-sensitive ion channels in volume regulation in boar and bull spermatozoa.

The ability to reverse swelling caused by hypo-osmotic stress is an important cell function; in spermatozoa, it is likely to be of consequence during ejaculation and also during the thawing process that terminates cryopreservation. In this study, the time course of boar and bull sperm volume changes after exposure to hypo-osmotic conditions at 39 degrees C was recorded. Cell volume measurements of washed sperm suspensions were performed electronically in Hepes-buffered saline solutions of 300 and 180 mosmol kg(-1) containing 2.5 mmol K(+) l(-1). Treatment with quinine in the presence or absence of the potassium ionophore valinomycin was used to determine whether potassium channels were involved in the reversal of swelling. After exposure to hypo-osmotic conditions, both bull and boar spermatozoa showed initial swelling (up to 200% and 140% of initial volume, respectively, within 5 min), which was subsequently partially reversed (to about 150% and 120%, respectively, after 20 min). Incubation with quinine led to an increase in swelling in both species. However, bull sperm volume was already maximal (up to 294%) after 30 s and declined thereafter, whereas boar sperm volume increased slowly to a maximum of about 220% after 20 min. Valinomycin treatment caused quinine-induced swelling in bull spermatozoa to decrease rapidly to control (no quinine, no valinomycin) values, whereas in quinine-treated boar spermatozoa it had an opposite, enhancing effect. Interpreting these results in the light of data from studies by others on a variety of cell types, it is proposed that swelling-activated potassium channels are involved in regulatory volume decrease in both species of spermatozoa, but that boar spermatozoa may contain fewer swelling-activated chloride channels than do bull spermatozoa.

Transformation-related cellular protein p53: increased level in untransformed rat cells following treatment with the tumorpromoter, tetradecanoylphorbol-acetate.

12-O-Tetradecanoylphorbol-13-acetate (TPA, 100 ng ml-1), a tumor promoting phorbol ester, is able to induce enhanced levels of the transformation-associated cellular antigen p53 in normal rat 2 cells which had not been previously initiated by a carcinogen. p53 was estimated in ethanol-fixed treated cells on microtiter plates with ELISA using the monoclonal antibody Pab 1620 [EMBO J. 7, 1485, (1984)]. Induction of p53 was confirmed by immunoblotting. This effect of TPA is an additional phenotypic characteristic of tumor cells which can be induced by TPA in untransformed rodent cells.