[Acquired temporary night blindness in vitamin A and zinc deficiency in anorexia nervosa nine years after kidney transplantation]. / Erworbene vorübergehende Nachtblindheit bei Vitamin-A- und Zinkmangel bei Anorexia nervosa neun Jahre nach Nierentransplantation.

BACKGROUND: Vitamin and trace element deficiencies may cause visual disturbances. Before starting a substitutional therapy, specific investigations should be performed. HISTORY AND SIGNS: We present a kidney-transplanted patient who suffered for 6 months from night blindness. The electroretinography showed a severe decrease of the rod activity. Except for an irregular pigmentation in the far periphery, the fundus appeared normal. These findings were indicative of a vitamin A and zinc deficiency. The laboratory tests showed decreased vitamin A and zinc serum levels. THERAPY AND OUTCOME: After three months of substitutional therapy the electroretinogram had normalized and the patient was free of symptoms. CONCLUSIONS: Visual disturbances due to vitamin and trace element deficiencies are rare in Europe. If suspected, since the diagnosis and the treatment of nutritional deficiencies are simple, specific investigations and a substitutional therapy should be initiated.

Assessing problems of organic hydroperoxide-induced chemiluminescence related to biological/medical samples.

The supernatants obtained from mammalian tissue homogenates, blood serum or other body fluids, and supplemented with organic hydroperoxide show a multiplicity of light-emitting reactions. The low-level chemiluminescence of biological samples denotes that after hydroperoxide-induction electronically excited species are produced. The light-emission measured by photomultipliers is related to (i) the geometrical location of the induced sample, (ii) light gathering capacity of the phototubes, and (iii) both the quantity and concentration of samples and reactants. The fewest blood contamination of biological samples leads to an increased photoemission. The very high sensitivity of light detectors requires stable measuring and sampling conditions and peculiarly cautious evaluation of the reactions.

Organic hydroperoxide-induced chemiluminescence of follicular fluid and blood serum samples obtained from women pretreated for in vitro fertilization.

The organic hydroperoxide-induced chemiluminescence of follicular fluid obtained from in vitro fertilized patients and its differently separated fractions were evaluated. Peroxidative stress causes a different photo-emission in the samples which alludes to some factors playing a role in the maintenance of the pro-oxidant/antioxidant balance. Interactions between the protein compounds of the samples and the organic hydroperoxide associate with formation of excited species contributing to the distinctive light emission processes. The technique offers a special re-interpretation of the scavenger state relating to the components of follicular fluid.

Asymmetric reactions in sonochemistry.

Sonochemical processes involved in asymmetric synthesis are reviewed. The goal of this overview is to provide a comprehensive picture about the fields of both enantioselective and diastereoselective reactions accelerated or initiated by ultrasounds. Since the most, in many cases comparative, data are available in heterogeneous metal catalysis, the emphasis will be placed on these enantioselective hydrogenations, however, other applications such as phase transfer catalysis etc. will also be cited.

[Albinism: diagnosis by visual evoked potentials]. / Albinismus: Diagnose mittels visuell evozierter Potenziale.

BACKGROUND: In albinism the majority of the nerve fibers of the optic nerve originating from an eye are innervating the contralateral hemisphere. As a result of the predominantly monocular innervation of the left and right hemispheres, the unilateral activation of the visual cortex (lateralization) can be detected with visual evoked potentials (VEP). PATIENTS AND METHODS: The VEPs were elicited with pattern onset stimulation. Five channels were recorded (2 channels over the left and right occipital lobe and 1 in the midline). 22 Patients with pendular nystagmus and 15 normal volunteers were examined. 5 of the normal volunteers were also examined with simulated pendular nystagmus (5-10 degrees, 1 Hz). The nystagmus was simulated by a simple galvanometer scanner based optical system. RESULTS: Unilateral activation of the hemispheres (lateralisation) was never detectable by normal volunteers. The lateralization of the VEP was detectable in all patients with oculocutaneous albinism with pattern onset stimulation. CONCLUSION: The pathological crossing of the nerve fibres in the optic chiasm is always detectable in oculocutaneous and ocular albinism with multichannel pattern onset VEP. The lateralization of the VEP is a more sensitive indicator of ocular albinism than other symptoms like macular hypoplasia, hypopigmentation, iris transillumination, nystagmus, reduced visual acuity et cetera.

Asymmetric sonochemical reactions enantioselective hydrogenation of alpha-ketoesters over platinum catalysts.

The sonochemical enantioselective hydrogenation of different alpha-ketoesters to the corresponding hydroxy derivatives over cinchona modified Pt catalysts is described. Ultrasonic irradiation was found to be beneficial in improving the optical yields. Besides studying the reaction rates and enantioselectivities, the effect of ultrasonics on the catalyst-modifier system and the scale-up of the process will also be considered.

Ultrasonics in chemoselective heterogeneous metal catalysis sonochemical hydrogenation of unsaturated carbonyl compounds over platinum catalysts.

The hydrogenation of unsaturated aldehydes was studied over ultrasonically pretreated silica supported platinum catalyst. In the hydrogenation of cinnamaldehyde a remarkable reaction rate and cinnamyl alcohol selectivity increase was observed. Using other unsaturated aldehydes the reaction rate and unsaturated alcohol selectivity increased moderately.

[Automatic measurement of dye filling of simultaneous digital ICG- and fluorescein angiography sequences]. / Automatische Berechnung der Kontrastmittelfüllung simultaner digitaler ICG- und Fluoreszeinangiographiesequenzen.

BACKGROUND: The ICG filling is supposed to be faster than Fluorescein filling. Interestingly the filling characteristics of these dyes were never correlated directly using precise quantitative methods. Since ICG and Fluorescein are injected as a mixture, the simultaneous 2-channel angiography provides a suitable method to correlate the filling characteristics of the dyes. MATERIAL AND METHODS: The simultaneous ICG and Fluorescein angiograms were recorded with a Rodenstock Scanning Laser Ophthalmoscope. The angiographic images were digitized real-time with a graphic workstation. Filling characteristics of the two dyes was calculated after off-line eye tracking in different regions of interests (ROIs) on the central retina. RESULTS: The Fluorescein filling was faster than the ICG filling in 56.5% of our patients. In 26% of our patients was a mixed filling detectable. Depending on the position of the ROIs the Fluorescein or ICG filling was faster. In only 17.5% of our cases was the ICG filling faster than the Fluorescein filling. CONCLUSION: Our results show that Fluorescein filling in more than 50% of the cases is faster than ICG filling and only a minority of the patients has a faster ICG filling. According to our experience the filling pattern of the two dyes is individual, there is no rule of thumb for the filling.

[Simultaneous ICG- and fluorescein-angiography for fundus examination]. / Simultane ICG- und Fluoreszeinangiographie in der Fundusdiagnostik.

BACKGROUND: An indocyanine-green (ICG) angiography is rarely used as the only diagnostic procedure. Almost always it is performed additionally to a fluorescein angiography. The use of simultaneous ICG and fluorescein (SIF) angiography therefore makes sense. Several examples for the application of SIF-angiography are presented. MATERIALS AND METHODS: SIF-angiography was performed using a 2-wavelength scanning laser ophthalmoscope (SLO). Images were digitally recorded in real time with a graphics workstation. The following cases will be presented: choroidal neovascularization in age-related macular degeneration, choroidal hemangioma, inflammatory fundus disease (APMPPE) and idiopathic polypoidal choroidal vasculopathy. RESULTS: ICG and fluorescein angiography can be simultaneously recorded with the 2-wavelenghth SLO. The quality of the combined pictures is comparable to single-channel recordings of separate ICG and fluorescein images. We show results of the above mentioned cases. CONCLUSIONS: SIF angiography is time efficient and allows precise comparison and analysis of the transit of both dyes through retinal and choroidal circulation. The topographic relation of pathologic findings in ICG angiograms with the critical retinal vascular landmarks is facilitated.

Sonochemical hydrosilylation of 2-substituted cyclohexanones in the presence of Wilkinson complex.

The sonochemical hydrosilylation of alkyl substituted cyclohexanones catalyzed by Rh (PPh3)3Cl is described. The application of ultrasonic irradiation during the reaction highly enhances the reaction rates and produces higher yields than those obtained in silent reactions. The stereoselectivity of the reaction has not been changed, the isomeric distribution, i.e. the cis/trans ratio of the 2-substituted cyclohexanols formed, is very close to those obtained in conventional stirred reactions.

Ultrasonics in heterogeneous metal catalysis: sonochemical chemo- and enantioselective hydrogenations over supported platinum catalysts.

Sonochemical chemo- and enantioselective hydrogenations over supported platinum catalysts are described. We disclose our results with respect to a sonochemical modification of the chemoselective hydrogenation of cinnamaldehyde over supported platinum catalysts, and the asymmetric hydrogenation of ethyl pyruvate promoted by various ultrasonic pretreatments. The ultrasonic pretreatment of the supported platinum catalysts was found to be highly beneficial in almost every case, improving both the catalytic activity and selectivity. The effect of additional experimental variables, such as hydrogen pressure, catalyst support, temperature and the ultrasonic insonation time were also studied. The enantioselectivity of the hydrogenation of ethyl pyruvate increased up to 97.1% ee. In the case of cinnamaldehyde hydrogenation, the selective preparation of cinnamyl alcohol became possible. The theoretical aspects of the working mechanisms in comparison with 'silent' reactions will also be provided.

Homogeneous and heterogeneous asymmetric reactions: Part 11. Sonochemical enantioselective hydrogenation of trifluoromethyl ketones over platinum catalysts.

Enantioselective sonochemical hydrogenation of alpha,alpha,alpha-trifluoromethyl ketones, namely, 1,1,1-trifluoroacetophenone and 1,1,1-trifluoro-phenylacetone was carried out over various platinum catalysts modified by cinchonidine in different solvents. Both compounds yielded the (R)-alcohol as major product. The reaction rates and the enantiomeric excesses were determined over Pt/C, Pt/SiO2, Pt/K-10 and Pt/Al2O3 catalysts under conventional conditions. Since Pt/Al2O3 exhibited the best catalytic performance the effect of ultrasound on the catalytic activity and enantioselectivity was tested using this catalyst applying different sonochemical pretreatments. These methods included a pretreatment before the reaction in hydrogen and oxygen or both. The ultrasonic irradiation was found to be highly advantageous in the case of trifluoroacetophenone, whereas only moderate changes were observed using trifluoro-phenylacetone. After insonation of the catalyst, the enantioselectivity was considerably improved. Both the aerobic and anaerobic sonochemical pretreatments resulted in significant improvement in optical yield (up to 49% and 17% ee, at room temperature under 10 bar in 1,2-dichlorobenzene). In parallel, the hydrogenation rates increased to a small extent (1.1-1.2-fold increase) after hydrogenative ultrasonic pretreatment, whereas the rates decreased by a factor of 1.5-2 after aerobic insonation. To obtain more insight into the process, the effect of insonation time on the activity and enantioselectivity and actual changes of the catalyst were also studied.

[Digital internet-based ophthalmologic image databank]. / Digitale Internet-basierte ophthalmologische Bilddatenbank.

OBJECTIVE: To manage an ophthalmological image database easily and rationally. MATERIALS AND METHODS: Fundus, macro and simultaneously recorded Fluorescein and ICG angiography images were digitized and archived using personal computers and UNIX workstations. Image data were written to CD-recordables. The CD-s with image information were stored in a jukebox-server. On demand image information was converted to dynamic hypertext markup language (html) with a WWW-server. Information stored on the servers could be observed with browser programs running on client computers connected to local area network. The communication with ophthalmologist working outside our hospital was realized by electronic mail. RESULTS: Different platforms (PC, Mac, workstations, etc.) and operating systems (Windows 3.x, 95, NT, MacOS, UNIX, etc.) can be used as clients. The communication with the system is accomplished by standard internet programs (Internet Explorer, Netscape Navigator, etc.). Thanks to the intuitive graphical user interface, no special computer knowledge is required to retrieve the stored data. CONCLUSION: Our digital image database has many advantages over a conventional image archive: it is round the clock available, images can be stored and copied without loss of quality, digital images can be easily integrated in other applications, it can be used without special computer knowledge, it is expandable and compatible with all contemporary computer platforms.

Sonochemical enantioselective hydrogenation of ethyl pyruvate over platinum catalysts.

Chiral sonochemical hydrogenation of an aliphatic alpha-ketoester, ethyl pyruvate to ethyl lactate was carried out over various platinum catalysts in different solvents under atmospheric hydrogen pressure. The reaction rates and the enantiomeric excesses were determined over Pt/C, Pt/SiO2 and Pt/K-10 catalysts both under conventional and sonochemical conditions. The effect of ultrasounds on the catalytic activity and enantioselectivity was tested applying sonochemical pretreatment before the reaction. The ultrasonic irradiation was found to be highly advantageous in these hydrogenations. After insonation of the catalysts, the enantioselectivity was highly improved over Pt/SiO2 and Pt/K-10 catalysts. In addition, the reactions took place in quantitative yield and with complete chemoselectivity and the hydrogenation rates increased with one order of magnitude despite the very mild (atmospheric hydrogen pressure, room temperature) experimental conditions.

[Simultaneous digital indocyanine green and fluorescein angiography]. / Simultane digitale Indocyaningrün- und Fluoreszeinangiographie.

BACKGROUND: The simultaneous recording of indocyanine green and fluorescein angiography is since more than twenty years possible. The real-time digital recording of angiograms is about since 10 years possible. Because of the poor temporal resolution due to technical limitations, both of the above methods were only seldom used routinely. Graphics workstations can digitize and store multiple video sources real-time with full video framerate. Comparing to conventional videoangiography, the quality can be improved significantly. MATERIALS AND METHODS: Simultaneous ICG and Fluorescein (SIF) angiography images of a two-channel Scanning Laser Ophthalmoscope were digitized and stored real-time at a rate of 28-50 images/sec using a graphics workstation. The digitized image sequence could be replayed as a motion picture and/or single images of the recorded sequence could be analyzed separately. RESULTS: The simultaneous digital recording of angiograms is easier, than using two video tape recorders. It was possible to enhance the quality of the stored images using standard digital image processing procedures. Morphological measurements and densitometry were done with software developed for the UNIX workstation, or with personal computers using standard software packages. CONCLUSION: Simultaneous digital ICG and fluorescein angiography has several advantages over conventional video-angiographies: the image quality is better, data retrieval is easier, it is easier to perform than conventional video angiography, image can be accessed through a computer network, it is easy to perform morphological and densitometrical measurements, etc.

The radical scavenging ability of garlic examined in various models.

The influence of an intake of garlic powder (1% added to a standard chow for an 8 week period) on the susceptibility to ventricular arrhythmias under radical reperfusion was investigated in the isolated rat heart perfused with a modified Krebs-Henseleit solution and the generating system hypoxanthine/xanthine oxidase. The incidence of ventricular fibrillation (VF) after the reopening of the LAD was significantly reduced in the garlic group as compared to the untreated controls (VF: 50% vs 89%). As this protective effect might relate to radical scavenging capacities, two in vitro radical generating test systems were chosen where the garlic activity could be determined. Dose-dependently, garlic was able to capture the radicals. Interestingly, only the garlic extract, was active. The ethanol extract hardly showed any radical scavenging ability. According to this result, we concluded that an intact alliin-alliinase system is important for the activity of garlic. Further investigations were done with different tissues under oxidative stress conditions. The kinetics of each organ, were measured chemiluminometrically. Especially liver and kidney of garlic fed rats showed inhibiting effects. Finally, an attempt was made to relate these radical scavenging and lipidperoxidation inhibiting effects to respective garlic compounds. Two substances, allylmercaptane and diallyldisulfide, were proposed.

Simultaneous indocyanine green and fluorescein angiography.

PURPOSE: To facilitate the interpretation of the choroidal dye filling sequence, the use of simultaneous indocyanine green (ICG) and fluorescein angiography was evaluated. METHODS: A single-wavelength scanning laser ophthalmoscope (SLO) was modified to a two-wavelength system, permitting the simultaneous recording of ICG and fluorescein angiography. This method has been used in 340 cases. About two thirds of the patients had well-defined or occult choroidal neovascularization (CNV) in age-related macular degeneration (AMD). RESULTS: Simultaneous ICG and fluorescein angiography is feasible with a two-wavelength SLO and provides images of good quality. Two corresponding ICG and fluorescein angiography pictures can be presented as one combined red-green picture. CONCLUSION: This method has three advantages: (1) it allows a precise comparison of the transit of both dyes through both circulations, and there are no differences in the injected bolus nor in the actual blood pressure; (2) the important features of the ICG angiograms are fully aligned with the critical retinal vascular landmarks provided by the fluorescein images; and (3) it is very time efficient--with a single injection and one photographic session, immediate results are obtained.