Advances in broad bandwidth light sources for ultrahigh resolution optical coherence tomography.

Novel ultra-broad bandwidth light sources enabling unprecedented sub-2 microm axial resolution over the 400 nm-1700 nm wavelength range have been developed and evaluated with respect to their feasibility for clinical ultrahigh resolution optical coherence tomography (UHR OCT) applications. The state-of-the-art light sources described here include a compact Kerr lens mode locked Ti:sapphire laser (lambdaC = 785 nm, delta lambda = 260 nm, P(out) = 50 mW) and different nonlinear fibre-based light sources with spectral bandwidths (at full width at half maximum) up to 350 nm at lambdaC = 1130 nm and 470 nm at lambdaC = 1375 nm. In vitro UHR OCT imaging is demonstrated at multiple wavelengths in human cancer cells, animal ganglion cells as well as in neuropathologic and ophthalmic biopsies in order to compare and optimize UHR OCT image contrast, resolution and penetration depth.

Ultrahigh resolution Fourier domain optical coherence tomography.

We present, for the first time, in vivo ultrahigh resolution (~2.5 microm in tissue), high speed (10000 A-scans/second equivalent acquisition rate sustained over 160 A-scans) retinal imaging obtained with Fourier domain (FD) OCT employing a commercially available, compact (500x260mm), broad bandwidth (120 nm at full-width-at-half-maximum centered at 800 nm) Titanium:sapphire laser (Femtosource Integral OCT, Femtolasers Produktions GmbH). Resolution and sampling requirements, dispersion compensation as well as dynamic range for ultrahigh resolution FD OCT are carefully analyzed. In vivo OCT sensitivity performance achieved by ultrahigh resolution FD OCT was similar to that of ultrahigh resolution time domain OCT, although employing only 2-3 times less optical power (~300 microW). Visualization of intra-retinal layers, especially the inner and outer segment of the photoreceptor layer, obtained by FDOCT was comparable to that, accomplished by ultrahigh resolution time domain OCT, despite an at least 40 times higher data acquisition speed of FD OCT.

Compact, low-cost Ti:Al2O3 laser for in vivo ultrahigh-resolution optical coherence tomography.

A compact, low-cost, prismless Ti:Al2O3 laser with 176-nm bandwidth (FWHM) and 20-mW output power was developed. Ultrahigh-resolution ophthalmic optical coherence tomography (OCT) ex vivo imaging in an animal model with approximately 1.2-microm axial resolution and in vivo imaging in patients with macular pathologies with approximately 3-microm axial resolution were demonstrated. Owing to the pump laser, this light source significantly reduces the cost of broadband OCT systems. Furthermore, the source has great potential for clinical application of spectroscopic and ultrahigh-resolution OCT because of its small footprint (500 mm x 180 mm including the pump laser), user friendliness, stability, and reproducibility.

Continuous-wave mode-locked Ti:sapphire laser focusable to 5 x 10(13) W/cm(2).

Generation of sub-10-fs pulses with an average power of 1 W and a peak of 1.5 MW from a Kerr-lens mode-locked mirror-dispersion-controlled Ti:sapphire laser is demonstrated. A specially designed lens triplet focuses the output of this compact all-solid-state source to a peak intensity in excess of 5x10(13) W/cm (2) . Nonperturbative nonlinear optics is now becoming feasible by use of the output of a cw mode-locked laser.

Sub-10-fs mirror-dispersion-controlled Ti:sapphire laser.

We demonstrate the generation of nearly bandwidth-limited 8-fs optical pulses near 0.8 microm from a self-mode-locked Ti:sapphire laser oscillator, using chirped dielectric mirrors for dispersion control. The mode-locking performance is described, and limitations are discussed.

Opioid influence on the adherence of granulocytes to human umbilical vein endothelial cells in vitro.

Recent studies revealed the existence of opioid receptors on human polymorphonuclear leukocytes (hPMN) and reported the effects of endogenous opioids on hPMN migration and adherence on glass or serum coated glass. Extending these studies, two different assay systems served to quantify the two basic events of adherence: attachment and spreading. hPMN in suspension were allowed to settle under the influence of beta-endorphin on human umbilical vein endothelial cells. After 30 and 240 sec the number of attached cells was enhanced 2.5-fold. Studying the spreading of cells, beta-endorphin increased the area 1.5-fold. Since adherence precedes the migration of hPMN through the endothelial layer towards foci of inflammation, the results suggest a modulatory role of endogenous opioids in defence mechanisms.

Migration assay for endothelial cells in multiwells. Application to studies on the effect of opioids.

An assay system is described which permits rapid and effective evaluation of endothelial cell repair, using cells growing in a monolayer. With this method it was possible to obtain highly significant results. For example, endothelial growth factor and heparin, significantly enhanced cell migration and/or proliferation, whereas beta-endorphin, an endogenous opioid, had no effect on the migration and/or proliferation of human umbilical vein endothelial cells. This model may be used to study the cell migration of a variety of cell types which under certain experimental conditions (e.g., irradiation) do not proliferate.

[A rare finding at gynaecological laparotomy: ovarian pregnancy and pinworm abscess (author's transl)]. / Seltene gynäkologische Operationsbefunde: Ovarialgravidität und Oxyurenabszess

A case of concommitant ovarian pregnancy and pinworm abscess is described. The histology and the incidence of Oxyuriasis in the female genital tract are discussed. The clinical symptoms and the management of the condition are also discussed.