[Cut quality of a new femtosecond laser system]. / Schnittqualität eines neuen Femtosekundenlasers.

OBJECTIVE: The aim of this study was to evaluate the cut quality and the cellular damage when using a new 200 kHz femtosecond laser. METHODS: 20 porcine eyes and 3 human eyes, not suitable for transplantation, were used for this study. The WaveLight UltraFlap femtosecond laser was used for flap creation. The surface of the cornea, the structure and ultrastructure of the corneal cells and stroma were evaluated thoroughly using light microscopy (HE-, PAS- and Picrosirius red staining), transmission electron microscopy (TEM), and scanning electron microscopy (SEM). RESULTS: In all eyes, the flap could be lifted very easily and the flap appeared very smooth. Structural and ultrastructural evaluation with light and transmission electron microscopy on epithelium and endothelium showed no side effects of the laser application. The area around the flap cut was minimally affected and the keratocytes and collagen fibres showed minimal alteration due to laser treatment. Scanning electron microscopy revealed in all cases smooth surfaces and precise sidecuts. CONCLUSIONS: Precise corneal flaps can easily be created with this new femtosecond laser. At the same time, no structural and thermal side effects on corneal epithelium, stroma and endothelium appeared. Hence with this new femtosecond laser corneal flaps could be created easily without noteworthy side effects.

Uterine androgen receptor mRNA expression in metestrous and anestrous bitches being healthy or suffering from Pyometra.

The importance of androgens for the female reproductive system has been investigated for decades and a number of androgen sensitive processes has now been identified in female reproductive organs. For carnivore species no data were available so far about uterine androgen sensitivity and its regulation. The present study therefore aimed to investigate whether androgen receptors (AR) are present in the dog uterus, whether they are regulated throughout the ovarian cycle and whether pyometra affects their expression rate. Uterine tissue samples were collected from 28 bitches of different ages and various breeds. The samples were grouped according to the stage of estrous cycle (metestrus ME or anestrus AE) and the pathological status of the uterus (i.e. suffering from pyometra or not). Androgen receptor mRNA (AR mRNA) was quantified from 500 ng of total RNA isolated from the tissue samples using an internally standardized reverse transcription polymerase chain reaction (RT-PCR) described previously. The amount of total RNA extractable per g tissue was elevated during pyometra. The successful amplification of the expected 172 bp fragment from canine uterine RNA together with the confirmation of the identity of this fragment by sequence analysis, demonstrates that AR is expressed in this particular tissue. Comparing the expression rates in uteri from bitches during ME or AE being healthy (H) or suffering from pyometra (P), the only significant (p < 0.01) difference was found between H and P uteri during ME with 3.5-fold lower expression rates in P. Although the same seems true for AE bitches, a significant difference could not be demonstrated due to the low number (n = 2) of diseased animals in the AE group. There was no evident effect of the stage of ovarian cycle on uterine AR mRNA levels.

[Acute retinal necrosis and HIV infection]. / Akute Retinanekrose (ARN) und HIV-Infektion.

Acute retinal necrosis (ARN) is increasingly being observed among patients with HIV infection. Varicella-zoster virus (VZV) and herpes simplex virus (HSV) are recognized as being the etiologic agents in this syndrome. Among the 538 patients with HIV infection (261 of these with AIDS), who were followed up in our department between 1985 and 1990, we diagnosed ARN in 4 cases. Three of these patients suffered from AIDS. Thus, ARN was the third-most-frequent form of retinitis in our patients with AIDS (prevalence 1.1%), following Cytomegalovirus (CMV) retinitis (17.2%) and toxoplasmosis-retinochorioiditis (2.7%). The course of ARN in patients with AIDS is demonstrated in four case reports. Special features of the retina are documented by photographs of the fundus. The authors suggest that patients with AIDS who experienced an episode of VZV- or HSV infection which necessitated high-dose systemic aciclovir therapy are at risk of developing ARN. We recommend that they be kept on virustatic maintenance therapy.