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S Wolf

Publications and source records attributed to S Wolf.

At least 271 records · Page 15Linked to original sources
PubMed1990

[Quantifying retinal capillary circulation using the scanning laser ophthalmoscope].

The quantitative picture analysis of video fluorescein angiograms allows one to evaluate retinal hemodynamics. However, this method does not permit us to quantify the retinal capillary perfusion. Now, for the first time, we are able to quantify capillary bloodflow directly and objectively by means of scanning laser ophthalmoscopy. Even the measurement of the bloodflow velocity in all capillaries is now possible. Using digital frame-to-frame picture analysis of digital recordings, bloodflow velocities can be measured on the basis of the movement of dye boluses.

Blood Flow Velocity↗
PubMed1989

Movement protein of tobacco mosaic virus modifies plasmodesmatal size exclusion limit.

The function of the 30-kilodalton movement protein (MP) of tobacco mosaic virus is to facilitate cell-to-cell movement of viral progeny in an infected plant. A novel method for delivering non-plasmalemma-permeable fluorescent probes to the cytosol of spongy mesophyll cells of tobacco leaves was used to study plasmodesmatal size exclusion limits in transgenic plants that express the MP gene. Movement of fluorescein isothiocyanate-labeled dextran (F-dextran) with an average molecular mass of 9400 daltons and an approximate Stokes radius of 2.4 nanometers was detected between cells of the transgenic plants, whereas the size exclusion limit for the control plants was 700 to 800 daltons. No evidence of F-dextran metabolism in the leaves of the transgenic plants was found. Thus, the tobacco mosaic virus movement protein has a direct effect on a plasmodesmatal function.

Dextrans↗
PubMed1989

Video fluorescein angiography: method and clinical application.

Video fluorescein angiography, combined with a picture analyzing system, is a clinically applicable, objective method of evaluating the retinal blood-flow parameters. Optical density measurements were performed on videorecordings of fluorescence angiograms by means of a picture-analyzing system in order to determine the circulation parameters of the retina. These included: the arm-retina time (ART), the arteriovenous passage time (AVP), and the mean arterial dye-bolus velocity (MDV). Normal values for these parameters were derived from measurements in 75 healthy volunteers. The mean arm-retina time (ART) was 11.2 +/- 3.3 s, the mean arteriovenous passage time (AVP) 1.45 +/- 0.4 s and the mean arterial dye-bolus velocity (MDV) 6.39 +/- 1.7 mm/s. No significant correlation could be shown between pulse or blood pressure and one of the retinal circulation parameters. A group of ten healthy volunteers was examined twice in order to obtain the intraindividual variation for the measuring parameters. The coefficient of variation for the ART was 18%, 10% for the AVP, and 26% for the MDV.

Adolescent↗
PubMed1989

What sexual offenders tell us about prevention strategies.

A sample of 20 adult sexual offenders were interviewed about the process whereby they selected, recruited and maintained children in a sexual abuse situation. Offenders were selected if they were making "successful" progress in treatment in order that they might be less likely to distort their descriptions. Offenders were interviewed by their therapist in a community treatment program using a semistructured interview guide. Results suggest that this sample of offenders claim a special ability to identify vulnerable children, to use that vulnerability to sexually use a child that sexual abuse is inherently coercive, even though many offender statements minimize the level of coercion and violence, and that offenders systematically desensitize children to touch. Implications for prevention of sexual abuse are highlighted.

Adult↗
PubMed1989

[Video fluorescein angiography follow-up of patients with retinal artery occlusion].

Forty patients (age 67 +/- 9 years) with acute central artery obstruction (CAO; n = 20) or branch artery occlusion (BAO; n = 20) of the retina were examined in a prospective study. All patients received a hypervolemic or isovolemic hemodilution, depending on their hematocrit values, for a period of ten days. Clinical, hemodynamic, and rheological data of these patients were recorded before therapy, after ten days, and after six weeks. Under this therapy the central vision of 24 patients (CAO: n = 10; BAO: n = 14) improved by two or more stages. The extent of the circulatory disturbance was determined by arteriovenous passage time and dye bolus velocity. Compared with a control group, a significantly increased arteriovenous passage time and decreased dye bolus velocity were observed initially. The values after ten days of therapy and after six weeks were significantly improved (P less than 0.01) as compared to the initial values. Patients with longer latency showed almost normal retinal hemodynamics, even without therapy, after some weeks. However, in most cases the spontaneous improvement occurred too late. Therefore, it appears important to achieve early reperfusion by therapy.

Adult↗
PubMed1989

[Use of the scanning laser ophthalmoscope for recording pattern electroretinography and visual evoked cortical potentials].

With a scanning laser ophthalmoscope (SLO) variable patterned stimuli can be projected onto the retina. During alternation of these patterns visual evoked cortical potentials and pattern ERGs can be recorded. The configurations of the SLO-elicited potentials and peak latencies correspond to those evoked during conventional stimulation. During pattern stimulation the fundus and alternating pattern stimuli are observed simultaneously on a video monitor. Thus the examiner always knows the exact location of the stimulus on the retina. Scanning laser ophthalmoscopy could be a clinically interesting method of recording evoked potentials, because it enables the patient's retina to be viewed continuously at low light levels and makes electrophysiological examination of a defined region of the retina possible.

Electroretinography↗
PubMed1989

[Cell density of the corneal endothelium following cataract surgery].

Endothelial cell loss following extracapsular cataract extraction and implantation of a posterior chamber lens was studied and the influence of various factors analyzed. In 56 eyes, the mean reduction in cell density in the superior zone of the cornea was 19%. In the eyes with epithelial edema endothelial damage was more severe than average. Lower cell density was also found in particular in patients over 75 years old and those with pre-existing cornea guttata. In contrast, preexisting glaucoma, a history of corneal trauma, and, astonishingly, the surgeon's experience had no detectable influence on endothelial cell damage.

Aged↗
PubMed1989

[Effect of beta blockers on retinal hemodynamics. A double-blind study in healthy probands].

In a randomized double-blind study the effect of topically applied Timolol (Chibro-Timoptol 0.5%) on the retinal circulation was investigated. In order to quantify the retinal hemodynamics 20 healthy volunteers were examined twice using video fluorescein angiography. The arteriovenous passage time (AVP) and the dye bolus velocity (MDV) were quantified using an image-analyzing system. Following administration of Timolol, IOP decreased from 14.5 +/- 1.9 mm Hg to 9.4 +/- 1.7 mm Hg (P less than 0.010). The study also showed that there was a significant reduction in AVP from 1.75 +/- 0.5 s to 1.56 +/- 0.3 s (P less than 0.05) and an increase in MDV following local application of Timolol. No effect on systemic blood pressure or pulse rate was observed. The results indicate that in addition to its pressure-lowering effect, timolol also leads to increased retinal perfusion.

Adult↗
PubMed1989

[Rheologic findings in patients with Eales disease].

In a retrospective analysis of findings in 12 patients with Eales' disease significant changes in blood fluidity were established. The six female and six male patients, aged between 15 and 59, were examined in the acute and subclinical stages and when a recurrence occurred. The rheologic parameters plasma viscosity, erythrocyte rigidity, and erythrocyte aggregation were significantly increased in the acute stage and when there was a recurrence, while in the subclinical stage the rheologic values improved to normal. No correlation could be found between the severity of the clinical picture in the various phases and the rheologic values. None of the other biochemical, microbiologic, and immunologic parameters were pathologic in any stage of the disease. In particular, virus serology, protein, immune, and hemoglobin electrophoresis were normal in all patients. While the etiology of Eales' disease remains unknown, deteroration in erythrocyte rigidity appears to play a part in the pathophysiology of the disease.

Adolescent↗
PubMed1989

Vascular effects of naftidrofuryl in a randomized placebo-controlled double-blind study.

In a randomized, placebo-controlled, double-blind, crossover study in 10 volunteers it was demonstrated that intravenous administration of 200 mg naftidrofuryl (Dusodril, Praxilene) produced a slight but significant increase in the erythrocyte column diameters of conjunctival arterioles (mean diameter 17.5 +/- 7.6 microns) of 6.9% which persisted until 1 h after administration. The venules (mean diameter of the erythrocyte column 35.4 +/- 11.5 microns) are not significantly affected at the concentration tested. In their time course the results are in good agreement with the former measurements of the peripheral resistance and with the kinetic characteristic of the drug.

Adult↗
PubMed1989

[Video fluorescence angiography for studying the hemodynamics of the eye].

The fluorescence angiogram can be recorded continuously with a video camera equipped with a low light amplifier and attached to a 3/4-inch videorecorder. The light intensities are low enough not to disturb the patient. Indocyanine and infrared light are used to examine the choroid. Conventional fundus cameras with 30 degrees or 50 degrees frames can be used. The inflow of the dye may be followed through the arterioles into the precapillary vessels. The capillaries themselves can only be seen as diffuse background fluorescence. Subsequently, the filling of the venules can be seen. The quality of the videofluorescence angiograms also allows nonperfusion areas and leakage of the fluorescein to be identified. Compared to conventional photography, angiography using the videotechnique allows to evaluate the blood flow with electronic procedures. The dilution curves obtained from the image analyzing system are not perfect because of reperfusion of the dye, but the exact time point when the fluorescein appears in the arterioles and venules can be defined and reproduced. From such measurements the arteriovenous passage time (AVP) and the speed of the dye bolus in the vessel (FBG) can be calculated. The clinical value of videofluorescence angiography evaluated with the image analyzing system has been proven in more than 1000 patients suffering from diseases of the retinal circulation. In cases with thromboses of the central retinal veins, occlusion of the central retinal arteries, stenoses of the internal carotid arteries, diabetic retinopathy and arterial hypertension, the extent of the retinal circulation disturbances could be defined by measuring the AVP and the FBG.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1989

[Cognitive training in schizophrenic diseases].

The comparison of an experimental group of schizophrenic patients undergoing cognitive training with a control group was tested for significance over a total of 23 psychometric features, using the test known as t-distribution or "Students distribution". Cognitive training results in varying degrees of improvement in the various parameters. Uncharacteristic schizophrenic basic disorders remitted significantly, and there was improvement in activity of intention, BP/RS sum score, and the BP/RS factors of anxiety/depression, anergy, and activation. The NOSIE factors of manifest psychosis, irritability, and depression remitted, and social interest improved. From the psychological data it can be concluded that cognitive training can help improve, in particular, cognitive adjustment and adaptability, and the organisation of complex societal conditions.

Adult↗
PubMed1989

[Retinal hemodynamics and morphologic findings in patients with occlusion of the internal carotid artery].

Only a minor percentage of patients with occlusion of the internal carotid artery develops the clinical symptoms of ischemic ophthalmopathy. The degree of functional collateralization that mirrors the alteration in ocular perfusion seems to be of importance for its development. We employed video fluorescein angiography to determine the degree of minor retinal perfusion in 33 patients. With a picture analyzer (Microvideomat 3, Zeiss) we quantified the arm-retina time (ART), the arteriovenous passage time (AVP) and the arterial dye bolus velocity. In these patients retinal perfusion was significantly decreased compared to a normal control group. The AVP of 18 patients was more than triple the average normal value (1.45 +/- 4.0 s); 3 of these patients showed morphological signs of ischemic ophthalmopathy with extensive non-perfusion areas: they showed a change in retinal hemodynamics and a massive deficiency in vasomotor response to CO2 stimulation. After panretinal laser coagulation their retinal hemodynamics, morphological alterations and subjective complaints improved. Our results show that using video fluorescein angiography on patients suffering from occlusion of the internal carotic artery analyzing the retinal hemodynamics can help to determine whether ischemic ophthalmopathy is developing or not.

Adolescent↗
PubMed1988

Spontaneous gas formation in a sterile renal cell carcinoma.

Sterile gas formation is a common sequela of therapeutic transcatheter embolization of tumors. We report a patient who spontaneously developed gas collections within an uninfected renal cell carcinoma with a computed tomographic appearance very similar to that seen following embolization. Possible mechanisms for sterile gas formation are discussed.

Aged↗
PubMed1988

[Video fluorescence angiography follow-up of patients with retinal stasis syndrome].

Forty-four patients were examined by video-fluorescein angiography. With the onset of the first symptoms a significant decrease in retinal blood flow was determined by prolonged arteriovenous passage time (AVP) and diminution of mean dye bolus velocity (MDV). No correlation could be found between the extent of impeded retinal perfusion in the acute phase and the severity of the clinical appearance. In 35 of the 44 patients a favorable clinical course was observed. An initially markedly reduced retinal perfusion improved under treatment by isovolemic or hypervolemic hemodilution, fibrinolysis, and panretinal laser coagulation, and remained stationary during the further course of time. Complete normalization of the AVP and the MDV could not be found in any of these patients. Sixteen percent of the patients with retinal stasis syndrome developed hemorrhagic central venous thrombosis. In the authors' opinion videoangiographic follow-up of patients with retinal stasis syndrome is essential for early detection of further-reduced retinal perfusion. It may thus be possible to prevent the transition to hemorrhagic central retinal vein occlusion in these cases by early treatment.

Adult↗
PubMed1988

Effects of enzymatic blood defibrination in subcortical arteriosclerotic encephalopathy.

Plasma hyperviscosity is a striking abnormality in patients suffering from subcortical arteriosclerotic encephalopathy (SAE) and is thought to perpetuate the chronic ischaemic demyelinating process of the periventricular white matter. Ancrod, a defibrinating enzyme, was given to 10 patients with SAE in an attempt to reduce plasma fibrinogen, which would thus normalise hyperviscosity. This was paralleled by a significant improvement of the initially abnormal retinal arteriovenous passage time, as well as a significant augmentation of the CO2-induced cerebral vasomotor response. This did not lead, however, to any clinical improvement with respect to performance of neuropsychological tests, recurrences of strokes during a 6 month observation period or improvement of various audiological parameters. The findings indicate that hyperviscosity in patients with SAE is merely an epiphenomenon. A potentially reversible, chronic penumbral state of the brain tissue apparently does not exist in SAE.

Aged↗