Xanthine oxidase inhibitor tungsten prevents the development of atherosclerosis in ApoE knockout mice fed a Western-type diet

Hyperlipidemia enhances xanthine oxidase (XO) activity. XO is an important source of reactive oxygen species (ROS). Since ROS are thought to promote atherosclerosis, we hypothesized that XO is involved in the development of atherosclerosis. ApoE(-/-) mice were fed a Western-type (WD) or control diet. In subgroups, tungsten (700 mg/L) was administered to inhibit XO. XO is a secreted enzyme which is formed in the liver as xanthine dehydrogenase (XDH) and binds to the vascular endothelium. High expression of XDH was found in the liver and WD increased liver XDH mRNA and XDH protein expression. WD induced the conversion of XDH to the radical-forming XO. Moreover, WD increased the hepatic expression of CD40, demonstrating activation of hepatic cells. Aortic tissue of ApoE(-/-) mice fed a WD for 6 months exhibited marked atherosclerosis, attenuated endothelium-dependent relaxation to acetylcholine, increased vascular oxidative stress, and mRNA expression of the chemokine KC. Tungsten treatment had no effect on plasma lipids but lowered the plasma XO activity. In animals fed a control diet, tungsten had no effect on radical formation, endothelial function, or atherosclerosis development. In mice fed a WD, however tungsten attenuated the vascular superoxide anion formation, prevented endothelial dysfunction, and attenuated KC mRNA expression. Most importantly, tungsten treatment largely prevented the development of atherosclerosis in the aorta of ApoE(-/-) mice on WD. Therefore, tungsten, potentially via the inhibition of XO, prevents the development of endothelial dysfunction and atherosclerosis in ApoE(-/-) mice on WD.

Response of primary fibroblasts and osteoblasts to plasma treated polyetheretherketone (PEEK) surfaces

Polyetheretherketone (PEEK) is a synthetic polymer with suitable biomechanical and stable chemical properties, which make it attractive for use as an endoprothetic material and for ligamentous replacement. However, chemical surface inertness does not account for a good interfacial biocompatibility, and PEEK requires a surface modification prior to its application in vivo. In the course of this experimental study we analyzed the influence of plasma treatment of PEEK surfaces on the cell proliferation and differentiation of primary fibroblasts and osteoblasts. Further we examined the possibility of inducing microstructured cell growth on a surface with plasma-induced chemical micropatterning. We were able to demonstrate that the surface treatment of PEEK with a low-temperature plasma has significant effects on the proliferation of fibroblasts. Depending on the surface treatment, the proliferation rate can either be stimulated or suppressed. The behavior of the osteoblasts was examined by evaluating differentiation parameters. By detection of alkaline phosphatase, collagen I, and mineralized extracellular matrix as parameters for osteoblastic differentiation, the examined materials showed results comparable to commercially available polymer cell culture materials such as tissue culture polystyrene (TCPS). Further microstructured cell growth was produced successfully on micropatterned PEEK foils, which could be a future tool for bioartificial systems applying the methods of tissue engineering. These results show that chemically inert materials such as PEEK may be modified specifically through the methods of plasma technology in order to improve biocompatibility.

[Cyst of the common bile duct with acute abdomen]

Congenital cysts of the bile duct are well-documented anomalies of the biliary tree. Choledochal cysts frequently cause malignant changes in the epithelial lining. In such patients, the prognosis is very poor mainly because of the lack of typical symptoms in the early stages. The incidence of carcinoma in patients with bile duct cysts is estimated at 2.5 % to 15 %, compared to an incidence of 0.012 % to 0.48 % in patients without bile duct cysts. We report the case of a 32-year-old Vietnamese woman with a history of acute epigastric pain. Exploratory surgery was performed, and the segment containing the cyst and the ectopic pancreas was resected. Sonography pointed the way, and resection would have been necessary even without the abdominal symptoms.

[Prediction of outcome in ST elevation myocardial infarction by the extent of ST segment deviation recovery. Which method is best?]

Simple and rapid measures are needed for timely assessment of the quality of reperfusion therapy early after fibrinolysis in acute STEMI. Sum ST segment elevation resolution (sum STR) categorized into the three groups of low risk (complete ST resolution), medium risk (partial ST resolution), and high risk (no ST resolution) has become an established method to predict infarct size, left ventricular function, epicardial vessel patency, and mortality. However, measurement of the sum of ST elevation from all leads of repeated ECG's is time-consuming. For routine practice more simple measures are needed. This report summarizes recent findings on direct comparisons between different modes of evaluation of ST segment deviation recovery employed for risk stratification in large-scale mortality trials. With respect to predictive accuracy combined with simplicity, two methods were superior to the conventional model of sum STR: 1) ST segment deviation resolution in only the one ECG lead showing the maximal deviation (single lead STR), and 2) the existing ST segment deviation in the single ECG lead of maximum deviation present 90 or 180 min after start of fibrinolysis (max STE). In multivariate analyses the ST segment deviation recovery models including sum STR were significant independent predictors of short- and long-term mortality. In receiver-operating characteristic (ROC) curves for predicting mortality the analysis of single lead STR and max STE performed better than sum STR. After categorization into risk groups patients are best classified by max STE. With an ECG recorded at 90 min in 2719 patients, the proportion of patients of sum STR, single lead STR, and max STE were 40, 34, and 43% in the low risk groups, and 24, 31, and 25% in the high risk groups. Cardiac mortality rates at 30 days were 2.0, 1.2, and 1.0% in low risk versus 9.6, 10.3, and 12.8% in the high risk groups, respectively. Long-term mortality with a followup of 5 years was best predicted by max STE risk groups.

CONCLUSION

Single lead STR and max STE are very simple, inexpensive, non-invasive, and highly reliable measures which provide very strong early prognostic information. The relationship between degree of ST segment deviation recovery and subsequent mortality is remarkably consistent. Both methods perform better than sum STR in predicting mortality. They can be used for very early risk stratification and can form a basis for an individual treatment of patients after fibrinolysis for STEMI within 6 hours of symptom onset. Of the two methods max STE is even simpler to use and has better accuracy in predicting outcome.

Interferon-alpha inhibits interleukin-3-induced proliferation of Ba/F3 cells in a protein kinase R-dependent manner

We have previously shown that interferon-alpha (IFN-alpha) inhibits proliferation of Ba/F3 cells by interfering with the action of the mitogen interleukin-3 (IL-3) [Cell Signal 11 (1999) 769]. Here, we have characterised the role of protein kinase R (PKR), an IFN-alpha-inducible enzyme, in the mediation of IL-3-antagonistic IFN-alpha effects. Downregulation of PKR expression by antisense oligonucleotide treatment blocked IFN-alpha-induced growth inhibition. Reduction of PKR levels and overexpression of a dominant-negative PKR mutant correlated with diminished inhibitory IFN-alpha effects on the IL-3-dependent expression of a luciferase reporter construct, GAS-luc. Furthermore, increased nuclear levels of STAT1 (bound in ISGF3 complexes) were observed in PKR-depleted cells cultured with or without IFN-alpha. Together, our data indicate an essential role of PKR in the mediation of IL-3-antagonistic IFN-alpha effects on Ba/F3 cells. They also suggests that activation of STAT1, an essential mediator of IFN effects, is insufficient for growth inhibition if PKR is not expressed.

Tufted hair folliculitis associated with pemphigus vulgaris

Tufted hair folliculitis (THF) is a rare disease which is characterized by the emergence of multiple hairs from widely dilated follicular orifices surrounded by an inflammatory infiltrate resulting in scarring alopecia. The pathogenesis is not yet fully understood. Although colonization with Staphylococcus aureus could not always be detected and systemic treatment with antibiotics alone is not sufficient, this microorganism is considered to play an important role. Around 30 patients with THF have been reported since the first publication. We present a patient with pemphigus vulgaris who developed THF. To our knowledge, this is the fourth case with an association of these two entities. Amongst other causing mechanisms, the autoimmune reaction may play an important role for the development of THF.

Arrestin and its splice variant Arr1-370A (p44). Mechanism and biological role of their interaction with rhodopsin

Deactivation of G-protein-coupled receptors relies on a timely blockade by arrestin. However, under dim light conditions, virtually all arrestin is in the rod inner segment, and the splice variant p(44) (Arr(1-370A)) is the stop protein responsible for receptor deactivation. Using size exclusion chromatography and biophysical assays for membrane-bound protein-protein interaction, membrane binding, and G-protein activation, we have investigated the interactions of Arr(1-370A) and proteolytically truncated Arr(3-367) with rhodopsin. We find that these short arrestins do not only interact with the phosphorylated active receptor but also with inactive phosphorylated rhodopsin or opsin in membranes or solution. Because of the latter interaction they are not soluble (like arrestin) but membrane-bound in the dark. Upon photoexcitation, Arr(3-367) and Arr(1-370A) interact with prephosphorylated rhodopsin faster than arrestin and start to quench G(t) activation on a subsecond time scale. The data indicate that in the course of rhodopsin deactivation, Arr(1-370A) is handed over from inactive to active phosphorylated rhodopsin. This mechanism could provide a new aspect of receptor shutoff in the single photon operating range of the rod cell.

A double-radius Gandolfi X-ray camera for the generation of powder-like diffractograms of small single crystals, using an imaging plate detector

This is a report on the construction and the main features of an X-ray camera following the Debye–Scherrer geometry, combined with a sample mounting and rotation device for single crystals as first suggested by Gandolfi. Doubling of the camera radius and replacing of the wet-film technology by a highly dynamic imaging plate system allows well resolved digital diffraction patterns to be recorded within a short exposure time. Sophisticated calibration, correction and evaluation possibilities are supported by suitable software. Further optional improvements, such as the evacuation of the camera, the adaptation of totally reflecting collimators for an almost parallel primary X-ray beam and a built-in instead of an external imaging plate readout device, will further improve the resolution and peak to background ratio. The simple and versatile apparatus is indispensable for the fast and non-destructive identification of unique mineralogical or technical micro-samples in the form of single-crystal pieces. Initial representative data sets attest to the accuracy, efficiency and sensitivity of the method presented.

Extent of ST-segment deviation in a single electrocardiogram lead 90 min after thrombolysis as a predictor of medium-term mortality in acute myocardial infarction

BACKGROUND

In evolving myocardial infarction, assessment of the sum of early resolution of ST-segment elevation (sumSTR) has become an established method to predict outcome. We have found previously that mortality is predicted more accurately by the existing ST-segment deviation in the single electrocardiograph (ECG) lead with maximum deviation (maxSTE) 90 min after start of thrombolysis. This report compares the power to predict medium-term mortality by these two approaches.

METHODS

An ST-segment resolution substudy was done in conjunction with the Intravenous nPA for Treatment of Infarcting Myocardium Early (InTIME) II Study, which compared mortality in patients with acute myocardial infarction randomly assigned lanoteplase or alteplase. In 2719 patients, a 12-lead ECG was assessed at baseline and 90 min after the start of thrombolytic therapy.

FINDINGS

MaxSTE achieved a better combination of sensitivities and specificities for mortality prediction than sumSTR. The area under the receiver-operating characteristic curves for 180-day mortality prediction was 0.680 for maxSTE and 0.622 for sumSTR (difference 0.058; 95% CI 0.027-0.088). Risk groups categorised at low, medium, or high risk by maxSTE comprised 43%, 32%, and 24% of patients and those by complete, partial, or no sumSTR comprised 40%, 36%, and 24% of all patients. The 180-day mortality rates for the three maxSTE risk groups were 3.1%, 7.1%, and 16.2%, and those for the sumSTR groups were 4.8%, 8.1%, and 11.7%. The 12-month Kaplan-Meier estimates were 4.1%, 8.8%, and 18.6%, and 5.9%, 9.9%, and 13.7%, respectively.

INTERPRETATION

MaxSTE predicts early and medium-term mortality more accurately than does sumSTR. The prognosis for an individual patient can be accurately estimated simply by the ST-segment deviation present in one ECG lead recorded 90 min after thrombolysis.

Comparative genomic hybridization analysis of chromosomal alterations in patients with long-standing ulcerative colitis

Patients with ulcerative colitis (UC) are prone to develop colorectal cancer which is related to the duration and extent of the disease. One of the earliest events in tumor progression is the development of aneuploidy. Aneuploidy is correlated with the grade of dysplasia which serves as a common but not always reproducible marker for the prediction of UC associated formation of cancer. We analyzed 48 biopsy samples from 5 patients with long-standing ulcerative colitis by comparative genomic hybridization (CGH). The majority of these samples represented premalignant stages which are not well characterized at the molecular level as yet. We compared biopsy samples from different colon locations in regard to chromosomal alterations, dysplasia status and DNA index. Besides chromosomal changes occurring only in certain patients in restricted areas of the colon we also detected amplifications and deletions which were common in all persons throughout the colon. The stage of dysplasia seems to have no influence on the number and appearance of chromosomal changes. Amplifications in 2, 3, 6, 9, 11, 12 and 15 were found in almost all cases. In dysplastic samples chromosomal regions 3, 6 and 11 revealed gains of DNA. Deletions were detected within 8q, 15, 18q, 20p and 22q. The affected chromosomal regions may contain yet unknown oncogenes or tumor suppressor genes participating in UC associated carcinogenesis. The conspicuous regions found in the CGH experiments allow the selective and detailed characterization at a molecular level.

System for monitoring the focal position in laser material processing

A novel system for on-line measurement of the distance from the melt pool to the lens in laser material processing is described. A spectrometer analyzes the broadband radiation that is produced at the laser-workpiece interaction zone and then focused by the effector optics in the direction of the laser source. From the influence of chromatic aberration on the detected radiation spectrum, the distance from the workpiece to the lens can be derived. An analytical calculation of the shift of the melt pool spectrum that depends on the distance between the molten zone and the focusing lens shows good agreement with the measured results.

Extent of ST-segment deviation in the single ECG lead of maximum deviation present 90 or 180 minutes after start of thrombolytic therapy best predicts outcome in acute myocardial infarction

In evolving myocardial infarction the extent of ST segment deviation reflects the existing ischemic myocardial injury and thus conveys very useful early prognostic information. In recent years, the sum of ST segment elevation resolution (sum STR) has been proven to be an excellent early prognostic indicator. However, the predictive power of sum STR has never been systematically compared with that of other methods of evaluation of ST segment deviation recovery. We, therefore, proposed to compare the prognostic power of ST segment changes evaluated by either sum STR or by ST segment resolution in only the one lead showing the maximal deviation (lead STR) or only by the existing ST segment deviation in the single ECG lead of maximum ST deviation present at a given time point after thrombolysis (lead STE).

METHODS AND RESULTS

In conjunction with the Intravenous nPA for Treatment of Infarcting Myocardium Early (InTIME) II Study, which compared mortality in patients with acute myocardial infarction randomized within 6 hours of symptom onset to receive either Lanoteplase or Alteplase, all 3593 German and Polish patients participated in an ST segment resolution substudy. A 12-lead ECG was recorded at baseline and at 90 and at 180 minutes after start of thrombolytic therapy. The areas under the receiver-operating characteristic (ROC) curves to compare the power to predict 30 day cardiac mortality for sum STR, lead STR, and lead STE were at 90 min 0.686, 0.714, and 0.761 (p < 0.002), and at 180 min 0.678, 0.703, and 0.755 (p < 0.001), respectively. In multivariate analysis lead STE was an independent predictor of outcome even when adjustment was made for sum STR, lead STR, and clinical variables. Cardiac mortality rates at 30 days for lead STE risk groups, classified as low, medium, or high (percent of patients in brackets), were at 90 min 1.0% (43%), 4.0% (32%), and 12.8% (25%), and at 180 min 1.5% (55%), 3.8% (31%), and 15.2% (14%), respectively.

CONCLUSIONS

Simple measurement of the ST segment deviation existing in the one ECG lead with the greatest deviation on the ECG recorded 90 or 180 minutes after thrombolysis enables the identification of the major subsets of patients who are either at very low or exceptionally high risk of mortality.

Phase Locking of CO(2) Lasers

A method of phase locking two CO(2) lasers by radiation exchange is presented. This phase-locking was achieved by use of a copper prism as a beam folding device in the resonators and extraction of the output radiation by a common output coupler. Energy exchange led to a phase-locked state if several locking conditions were fulfilled. The amount of radiation injected from one resonator to the second cavity could be adjusted by movement of the prism. The influence of the strength of coupling on the locking range was studied. The beat signal between the two unlocked lasers could be measured, whereas in the case of phase-locked operation twice the intensity was detected. Despite the inclusion of several assumptions, a simplified mathematical model delivered good agreement between calculated and experimental results.

Effects of PUVA therapy on kidney allografts: results of a randomized prospective double-blind study

After successful experimental organ transplant studies on the efficacy of PUVA therapy combining donor pretreatment with the photosensitizer 8-methoxypsoralen (P) and the ex vivo irradiation of organs with long-wave ultraviolet light (UVA) prior to transplantation, we started in 1989 the first randomized, prospective, double-blind study to clarify the efficacy of PUVA therapy in human kidney transplantation. This study included 50 kidney donors, 25 of whom were PUVA-treated. A total of 75 kidneys were transplanted in Berlin, Halle and Rostock. The complete data of these 75 recipients were available for the final evaluation. The PUVA group (n = 36) and the non-PUVA group (n = 39) were not statistically significantly different as to donor and recipient data. Regarding the results, no differences were seen in initial hospitalization time, early graft function, rejection rate, number and time of rejection episodes. After a follow-up of 24 months, both graft survival (PUVA vs. non-PUVA: 75% vs. 71.8%) and patient survival (97.2% vs. 97.4%, respectively) were comparably high. PUVA therapy did not influence the development of vascular rejection. Interestingly, the rate of late graft loss after the 6th posttransplant month was lower, but not statistically significantly so, in the PUVA than in the non-PUVA-group (2 vs. 6 graft losses). Thus, PUVA-pretreated kidneys may be associated with a reduced development of chronic rejection.

Rapid decline of antibodies after hepatitis A immunization in liver and renal transplant recipients

BACKGROUND

Hepatitis A vaccine is safe and achieves good seroconversion rates in liver (LTX) and renal (RTX) transplant recipients.

METHODS

A study was performed to determine the anti-hepatitis A virus (HAV) antibody decline in LTX and RTX patients, and in healthy controls who have been immunized with two doses of hepatitis A vaccine.

RESULTS

LTX and RTX patients had a satisfactory seroconversion rate after complete immunisation. However, 2 years later they had experienced a much more rapid antibody decline than controls, and only 59% of LTX and 26% of RTX seroconverters showed titres above the cut-off level defined as protective.

CONCLUSIONS

Patients on immunosuppressive therapy may not be adequately protected against hepatitis A a few years after vaccination and alternative vaccination schemes may have to be considered.