Interleukin-11 Overexpression and M2 Macrophage Density are Associated with Angiogenic Activity in Proliferative Diabetic Retinopathy

ABSTRACT

Purpose

To investigate the expression of IL-11 and its receptor IL-11Rα and to quantify density of CD163⁺ M2 macrophages in proliferative diabetic retinopathy (PDR).     

Electronic speckle pattern interferometry: a novel non-invasive tool for studying drug transport rate through free films.

In this work, Electronic Speckle Pattern Interferometry (ESPI) is presented as a non-invasive tool to study drug transport in controlled release systems. ESPI is shown to be a feasible tool to measure drug film permeability via comparison with an ordinary diaphragm cell. A specially designed cuvette was used in the release study: the polymeric film separated the donor and the receiving chambers of the cuvette to create a diffusion cell with no mixing in the two chambers. Thus, the cuvette mimicked a coated system immersed in a stagnant bulk liquid. Concentration profile data were obtained for the two compartments. Using these data, it was possible to visually discriminate between a film subject only to diffusion and a film subject to diffusion as well as osmotic effects. Moreover, using the concentration profile data collected at different time intervals, it was possible to follow the film properties in terms of drug permeability, thus studying how drug permeability depended on drug concentration. Compared to other measuring techniques, ESPI offers the advantages that no invasive measurements are needed, and that no sampling and calibration are required. Furthermore, the permeability can be measured with no influence of mass transfer in the boundary layers.     

Intravenous fate of poly(2-(dimethylamino)ethyl methacrylate)-based polyplexes

The objective of this study was to assess the in vivo fate of poly(2-(dimethylamino)ethyl methacrylate) (pDMAEMA)-based polyplexes after intravenous administration into mice. Circulation kinetics and tissue distribution in terms of plasmid localization and transfection efficiency were assessed. To gain more insight into the observed biodistribution and gene expression profile, the interaction of pDMAEMA-based polyplexes with blood components (erythrocytes and albumin) was investigated in vitro. In the case of i.v. injection of positively charged polyplexes at a dose of 30 microg DNA most of the radioactivity was found in the lungs and the liver 60 min after injection. In the case of pDMAEMA/DNA polyplexes with a negative charge, uptake occurred mainly by the liver. Administration of positively charged complexes at a 30 microg DNA dose resulted in reporter gene expression primarily in the lungs. Injection of negatively charged complexes and naked plasmid did not result in luciferase expression in any of the organs examined. In vitro turbidity experiments showed the induction of a charge dependent aggregation process upon addition of albumin to the polyplexes pointing out to the involvement of aggregate formation in the dominant lung uptake of the positively charged polyplexes. Also, incubations of polyplexes after pre-incubation with a physiological concentration of albumin with washed erythrocytes confirmed that polyplexes induce the formation of extremely large structures. This paper underlines the need for the design of systems with reduced interaction with blood components to promote the delivery of DNA to target tissues outside the lungs.     

The relevance of therapeutic drug monitoring in plasma and erythrocytes in anti-cancer drug treatment.

Therapeutic drug monitoring generally focuses on the plasma compartment only. Differentiation between the total plasma concentration and the free fraction (plasma water) has been described for a number of limited drugs. Besides the plasma compartment, blood has also a cellular fraction which has by far the largest theoretical surface and volume for drug transport. It is with anti-cancer drugs that major progress has been made in the study of partition between the largest cellular blood compartment, i.e., erythrocytes, and the plasma compartment. The aim of the present review is to detail the progress made in predicting what a drug does in the body, i.e., pharmacodynamics including toxicity and plasma and/or red blood cell concentration monitoring. Furthermore, techniques generally used in anti-cancer drug monitoring are highlighted. Data for complex Bayesian statistical approaches and population kinetics studies are beyond the scope of this review, since this is generally limited to the plasma compartment only.     

The AIDS problem in accident surgery

In trauma surgery there is a particularly high proportion of patients in the age group most at risk of infection with AIDS. The result of an epidemiological study in our patients (HIV screening of all patients scheduled for surgery at a trauma center over 18 months) showed a prevalence of 0.1%. Specific therapeutic strategies must be developed to deal with the weakened immunity of HIV-infected patients. Fracture treatment in HIV-infected hemophiliacs is a special problem. Homogenous bone transplantation is described with reference to HIV. The particular danger of injury in trauma surgery is also investigated. The chain of infection is illustrated and used to demonstrate the precautions that can be taken against nosocomial HIV infections. Following infection with fluids containing HIV, specific measures must be taken. The legal aspects of HIV-antibody testing in the Federal Republic of Germany are elucidated. Finally, the problems of general preoperative HIV-antibody testing are discussed.     

Holographic interferometry forIn Vitro investigation of bioprosthetic valves

Dysfunction of heart valve prostheses—mechanical as well as biological—is a common problem in cardiac surgery. The reasons for the valve failures are still not well understood. Biological valves especially have an unsatisfactory durability; degeneration and calcification very often lead to the failure of the valves. In our opinion, hidden defects present in the valve material prior to implantation of the valves is a plausible explanation for the dysfunction. Hitherto there has been no technique to detect these defects without destructing the specimen. Holographic interferometry proved to be applicable forin vitro evaluation of mechanical heart valve prostheses. In the present paper we describe application of this method to biological valves. Nine porcine bioprostheses and four fresh porcine aortic valves were investigated by means of holographic interferometry. In eight of nine bioprostheses, the results showed irregularities of the leaflet structure which depend on anomalies of the connective tissue of the leaflets of the valves. To make sure that these findings are not due to normal variations of the morphology, the investigations were carried out with fresh and unfixated porcine aortic valves. In the latter, no such anomalies of the structure were detected. The results obtained confirm the above hypothesis on the origin of the later valve dysfunction. Thus, holographic interferometry tests of bioprostheses prior to their implantation prevent the use of potentially dysfunctional valves.Presented at the 35th World Congress, International College of Angiology, Copenhagen, Denmark, July 1993     

Recent influenza virus A infections in forensic cases of sudden unexplained death

Summary 84 forensic necropsy cases with a history of sudden unexpected death and where no acceptable cause of death was found at autopsy (= cases of sudden unexplained death, SUD) were found to have a significantly higher rate of influenza A (H 3 N 2) infection than did matched controls of the general population and a group of forensic necropsy cases with known cause of death (NON-SUD cases).By contrast, the group of SUD cases was found to have no significantly increased infection rate with influenza H 1 N 1 and B virus, parainfluenza viruses, RS virus, adenovirus, and cytomegalovirus.The influenza A associated SUD cases had a significantly higher rate of pathological and histological findings previously described for cases of primary viral pneumonia than did SUD cases without recent influenza A infection and NON-SUD cases.These findings suggest that virological examination of SUD cases could be helpful in order to determine the probable cause of death.A considerable portion of the influenza associated SUD cases occurred during interepidemic influenza periods. Therefore, such cases could be a useful source for monitoring the interepidemic spread of influenza virus.     

Coronary heart disease -- significance of coronary intervention]

Coronary revascularization using percutaneous coronary intervention (PCI) has rapidly developed in the past 2 decades and its technical and pharmaceutical improvements may avoid bypass surgery in many situations. The use of drug-eluting stents (DES) challenges the classic indications for bypass surgery and shifts them toward PCI, with the need for a critical appreciation of procedure- and patient-related risks. Furthermore, invasive measures such as intravascular ultrasound or pressure wire allow lesion-specific and immediate therapeutic decisions. This overview summarizes the actual potential of coronary intervention. To be aware of potentials and limitations may help the non-interventionalist to advise his patient and to choose the appropriate treatment.     

Case report: fusion of positron emission tomography (PET) and computed tomography (CT) images for image-guided endoscopic navigation in maxillofacial surgery: clinical application of a new technique.

INTRODUCTION: Surgery based on computed tomography (CT) data is becoming increasingly important in the head and neck region. The technique for hardware fusion between positron emission tomography (PET) and computed tomography (CT) has only been established commercially in the last 4 years. The advantages over CT alone are obvious. The surgeon is simultaneously provided with a map of anatomical as well as of functional (metabolic) details. The fused images offer improved localization of malignant lesions and improved targeting of biopsy, especially for small lesions. PURPOSE: A new technique for image-guided tumour localization for maxillofacial surgery based on PET/CT-image fusion is described. PATIENT AND METHOD: A 78-year-old woman was admitted to this department with a tumour of the skull base. Three dimensional fusion of computed CT with positron PET images on a commercially available navigation system is described. After patient-to-image registration, a high-resolution endoscope was calibrated intraoperatively. Image-guided biopsy specimens were taken under direct visual control. CONCLUSION: PET/CT-image fusion proved extremely helpful to navigate the endoscope to the target lesion and to identify the tumour.