Wolfgang Dorda

The blood-aqueous barrier and its permeability for proteins of different molecular weight.

In aqueous humors and sera from 44 patients with cataracts, albumin, IgG, and α-1-antitrypsin were measured using radial immunodiffusion. The mean concentrations of the three proteins were significantly smaller than values found in aqueous humors taken post mortem, but corresponded well to values found in cerebrospinal fluid. No statistically significant difference was found between men and women, normotensives and hypertensives, and patients with or without myopia of higher degree (> 6 diopters). A slight increase in protein concentrations in older patients and a relative decrease of α-1-antitrypsin is described. The aqueous humor-serum quotients of the different proteins showed a higher correlation than did the concentration of the proteins in aqueous humors. Im Kammerwasser und Serum von 44 an Cataract operierten Patienten wurden mit Hilfe der radialen Immundiffusion Albumin, IgG und α-1-Antitrypsin bestimmt. Die Mittelwerte waren gegenüber Werten im KW, das post mortem gewonnen wurde, deutlich erniedrigt, stimmen jedoch gut mit den Normwerten des Liquor cerebrospinalis überein. Es fand sich kein statistisch gesicherter Unterschied zwischen Männern und Frauen, Hypertonikern und Normotensiven, sowie Myopen (über 6 dptr) und Patienten mit nur geringen Brechungsfehlern. Es ließ sich jedoch ein schwacher Anstieg der Proteinkonzentrationen im höheren Alter sowie eine relative Verminderung von α-1-Antitrypsin feststellen. Es besteht eine engere Korrelation zwischen den KW-Serum-Quotienten der einzelnen Proteine, als zwischen den Konzentrationen der Proteine im KW selbst.

Management of data from clinical trials using the ArchiMed system

Clinical trials constitute a key source of medical research and are therefore conducted on a regular basis at university hospitals. The professional execution of trials requires, among other things, a repertoire of tools that support efficient data management. Tasks that are essential for efficient data management in clinical trials include the following: the design of the trial database , the design of electronic case report forms , recruiting patients , collection of data , and statistical analysis . The present article reports the manner in which these tasks are supported by the ArchiMed system at the University of Vienna and Graz Medical Schools. ArchiMed is customized for clinical end users, allowing them to autonomously manage their clinical trials without having to consult computer experts. An evaluation of the ArchiMed system in 12 trials recently conducted at the University of Vienna Medical School shows that the individual system functions can be usefully applied for data management in clinical trials.

Human tear lysozyme. A comparison of electro-immunodiffusion, radial immunodiffusion and a spectrophotometric assay.

In 116 persons (67 men and 49 woman) the tear fluid of both eyes was collected using paper discs and once more after topical anaesthesia. After weighing the discs and eluting the tear fluid, the lysozyme content was measured using two immunological methods [radial immunodiffusion (RID) and rocket immuno-electrophoresis (RIE)] and a spectrophotometric assay. Standard curves were established with purified human lysozyme and egg-white lysozyme. In addition, albumin was determined in all the samples by rocket immuno-electrophoresis. All lysozyme assays showed a high degree of correlation, the spectrophotometric technique giving significantly lower values (compared with RID and RIE) when human lysozyme was used for standardization.The lysozyme content of the tears did not correlate with the fluid uptake in the discs, but showed a significant decrease with age, which was abolished by topical anaesthesia. In contrast, albumin levels were dependent upon the weight and independent of the age of the patient.It is suggested that the determination of albumin as a ‘reference protein’ might help in comparing the results of different tear sampling techniques used by various groups, which induce variable amounts of reflex tearing.ZusammenfassungBei 116 Personen ohne Erkrankungen des äußeren Auges (67 Männer und 49 Frauen) wurde Trä nenflüßigkeit beider Augen mit Hilfe von Filterpapierscheibchen gewonnen. Dieser Vorgang wurde nach Applikation eines Lokalanästhetikums wiederholt. Nach dem Auswiegen und Eluieren der Tränenprobe wurde Lysozym mittels zweier immunologischer Methoden (der radialen Immundiffusion und der Immunelektrophorese) sowie einer spectrophotometrischen Technik bestimmt. Zur Erstellung der Standardkurven wurde gereinigtes menschliches, sowie Hühner-Eiweiß-Lysozym verwendet. Zusätzlich wurde Albumin mittels der Immunelektrophorese bestimmt.Die Werte aller Lysozym-Bestimmungen zeigten eine hohe Korrelation, wobei jedoch die Mittelwerte der turbidimetrischen Technik signifikant unter jenen der immunologischen Methoden lagen, wenn humanes Lysozym zur Erstellung der Standardkurve verwendet wurde.

A retrieval system for the selection and statistical analysis of clinical data

Within the last years computer-aided clinical documentation has provided researchers and administrators with very large volumes of data for research. User-friendly retrieval tools are needed when processing these clinical databases. Clinical researchers require applications by means of which steps in selection and analysis can be performed in an iterative process. During the deduction of statistical parameters from routinely collected data a number of problems occur that do not appear in the analysis of data gathered within clinical studies. Unlike clinical studies, routine data have complex structures and must first be formatted and above all temporally synchronized. In this paper we will describe the medical retrieval system ArchiMed developed at the Vienna General Hospital. A main objective in the design of this system was to support a joint evaluation of data from clinical studies and routinely collected data. The retrieval system comprises the main functions: Selection of Patients; Selection and Joining of Variables; and Statistical Analysis.

The Effect of Timolol on the Concentrations of Albumin and IgG in the Aqueous Humor of the Human Eye

We investigated albumin and IgG concentrations in the aqueous humor of 41 patients before intracapsular cataract extraction (primary samples) and at the end of surgery (secondary samples). Albumin and IgG concentrations were determined in all samples by means of a quantitative fluoroimmunoassay. A short-term topical application of timolol in 24 eyes was associated with a significant increase in both proteins in the primary aqueous humor samples compared with 17 control samples (P less than .005). The ratios of albumin to IgG--even when corrected for serum levels--were not significantly different in the two groups. Timolol did not affect the change in these ratios in the secondary aqueous humor samples. Thus, we concluded that these findings were not caused by a breakdown of the blood-aqueous barrier, but rather resulted from reduced aqueous humor flow and undisturbed protein filtration.

Clinical relevance of radiologic examination of the skeleton and bone density measurements in osteoporosis of old age

For the diagnosis of primary osteoporosis, various semiquantitative radiologic methods were compared in 149 unselected patients, aged over 50 years. Crush fracture syndrome (CFS), lumbar spine index (LSI), and Singh Index (SI) were assessed by three radiologists and after reevaluation, the intra-and interobserver errors were calculated. The reliability of the subjective grading was improved by joint and repeated reading of the radiographs. Additionally, the peripheral trabecular bone content was measured by photonabsorptiondensitometry (PAD). To test the value of the various semiquantitative methods, LSI, SI, and PAD have been compared with sex-matching before and after separation into age in decades in CFS-positive and CFS-negative patients. In an attempt to differentiate osteoporotics nonosteoporotics by CFS, our results indicate that CFS-positive and CFS-negative males cannot be separated by LSI, SI, and PAD, whereas in females these methods can discriminate irrespective of the age in decades. However, in age related groups, only SI can discriminate significantly between CFS-positive and CFS-negative females. Correlation of the semiquantitative methods, regardless of the diagnosis of a CFS, revealed a significant correlation-between SI and PAD, but no correlation between LSI and SI, and LSI and PAD, respectively.

Changes of the corneal endothelium following intracapsular cataract extraction with implantation of semiflexible anterior chamber lenses. I. Results of the early post-operative period.

A consecutive group of 103 patients with senile cataract underwent intracap‐sular cataract extraction and implantation of a semiflexible anterior chamber lens. After 6 month of follow‐up, there was an average decrease of 20% ±15% in central corneal endothelial cell density and an average vertical disparity of 32% ±20% between central and superior endothelial areas. The endothelial cell loss was not correlated with pre‐operative cell density. There was a positive correlation between age and cell loss and between age and vertical disparity. Findings in eyes with cornea guttata did not differ significantly from those without guttata. Anterior vitrectomy did not increase endothelial cell loss significantly. Maintenance of a deep anterior chamber by pre‐operative oculopression or by instillation of Na‐hyaluranate had no significantly different effect on the corneal endothelial cell loss.

Immediate changes in protein-concentration in aqueous humor induced by intracapsular lens extraction in human eyes.

In 71 patients that underwent intracapsular extraction of the cataract it was possible to collect aqueous humor (a.h.) in sufficient quantities at the beginning and at the end of the operation. Using radial immunodiffusion albumin, IgG and α-1-antitrypsin were measured in the samples. In secondary a.h. huge variations in the concentrations were apparent. The primary permeability of the blood-aqueous barrier and the time between sampling had no influence on the relative increase of the proteins.No statistically significant difference was found between normotensives and hypertensives and patients with or without myopia of higher degree (over 6 diopters). The relative increase of proteins according to their difference in molecular weight followed the same pattern as described for anterior uveitis. In patients for whom an enzymatic zonulolysis with trypsin was used for the extraction, the relative increase of IgG was significantly smaller than in those that did not receive this treatment (P<0.005). The possible sources contributing to the formation of secondary a.h. are discussed. Es konnten bei 71 Patienten, die wegen Trübungen der Augenlinse einer intracapsulären Extraktion unterzogen wurden, am Beginn der Operation primäres und unmittelbar vor Ende der Operation neugebildetes, “sekundäres” Kammerwasser (KW) in zur Untersuchung ausreichenden Mengen entnommen werden. In den Proben wurden mit Hilfe der radialen Immundiffusion Albumin, IgG und α-l-Antitrypsin bestimmt. Dabei fanden sich im sekundären KW außerordentlich große Schwankungen in der Konzentrationszunahme der verschiedenen Proteine. Die primäre Durchgängigkeit der Blut-Kammerwasser-Schranke und das Zeitintervall zwischen den Probenentnahmen schienen auf den relativen Anstieg der Eiweißkörper keinen Einfluß zu haben. Ebensowenig fand sich ein statistisch gesicherter Unterschied zwischen Hypertonikern und Normotensiven oder Myopen (über 6 dptr) und Patienten mit nur geringen Brechungsfehlern. Der Anstieg der einzelnen Proteine folgte jedoch, entsprechend ihrem Mole-kulargewicht, dem Verteilungsmuster wie es für die vordere Uveitis beschrieben wurde. Patienten, bei welchen eine enzymatische Zonulolyse mit Trypsin zur Extraktion verwendet wurde, wiesen einen statistisch signifikant geringeren relativen Anstieg des IgG im sekundären KW, im Vergleich zur unbehandelten Gruppe, auf (P > 0,005). Die möglichen Quellen, welche zur Bildung des sekundären KW beitragen können, werden diskutiert.

Originalliteratur Innerhalb von 24 Stunden

In den meisten Datenbanken findet man als Ergebnis seiner Literaturrecherche die genaue Zitation eines Zeitschriftenartikels und in vielen Fallen auch eine englische Zusammenfassung, das Abstract. Haufig reichen diese Abstracts fur einen ersten Uberblick uber ein Thema.

Gale Directory of Databases - Die „Datenbank der Datenbanken“

Gale Directory of Databases ist ein elektronisches Nachschlagewerk auf CD-ROM; in ihm findet man nahezu alle derzeit online, auf CD-ROM oder auf Diskette bzw. Magnetband verfugbaren Datenbanken. Insgesamt werden 8 800 Datenbanken beschrieben, davon sind 5 300 online zuganglich und 3 500 auf CD-ROM gespeichert.