Towards efficient production of highly optically pure d-lactic acid from lignocellulosic hydrolysates using newly isolated lactic acid bacteria

This study presents the production of D-lactic acid with high enantiomeric purity using lignocellulosic hydrolysates from newly isolated lactic acid bacterial (LAB) strains. Six strains, 4 heterofermentative and 2 homofermentative, were investigated for their ability to grow and produce lactic acid on sugar beet pulp (SBP) hydrolysates, containing a mixture of hexose and pentose sugars. Among the strains tested, three were isolates designated as A250, A257 and A15, all of which belonged to the genus Leuconostoc. Only strain A250 could be reliably identified as Leuconostoc pseudomesenteroides based on cluster analysis of Maldi-ToF spectra. All strains produced D-lactic acid in the presence of SBP hydrolysates, but with varying optical purities. The homofermentative strains achieved higher D-lactic acid optical purities, but without assimilating the pentose sugars. Co-cultivation of the homofermentative strain Lactobacillus coryniformis subsp. torquens DSM 20005 together with the heterofermentative isolate A250 led to the production of 21.7 g/L D-lactic acid with 99.3 % optical purity. This strategy enabled the complete sugar utilization of the substrate. Nanofiltration of the SBP hydrolysate enhanced the enantiomeric purity of the D-lactic acid produced from the isolates A250 and A15 by about 5 %. The highest D-lactic acid concentration (40 g/L) was achieved in fed-batch cultures of A250 isolate with nanofiltered SBP, where optical purity was 99.4 %. The results of this study underline the feasibility of a novel isolate as an efficient D-lactic acid producer using lignocellulosic hydrolysates.

Supramolecular Self-Assembly of β3 -Peptides Mediated by Janus-Type Recognition Units

To gain mechanistic insights, natural systems with biochemical relevance are inspiring for the creation of new biomimetics with unique properties and functions. Despite progress in rational design and protein engineering, folding and intramolecular organization of individual components into supramolecular structures remains challenging and requires controlled methods. Foldamers, such as β-peptides, are structurally well defined with rigid conformations and suitable for the specific arrangement of recognition units. Herein, we show the molecular arrangement and aggregation of β3 -peptides into a hexameric helix bundle. For this purpose, β-amino acid side chains were modified with cyanuric acid and triamino-s-triazine as complementary recognition units. The pre-organization of the β3 -peptides leads these Janus molecule pairs into a hexameric arrangement and a defined rosette nanotube by stacking. The helical conformation of the subunits was indicated by circular dichroism spectroscopy, while the supramolecular arrangement was detected by dynamic light scattering and confirmed by high-resolution electrospray ionization mass spectrometry (ESI-HRMS).

H+ Transport by K+ EXCHANGE ANTIPORTER3 Promotes Photosynthesis and Growth in Chloroplast ATP Synthase Mutants

The composition of the thylakoid proton motive force (pmf) is regulated by thylakoid ion transport. Passive ion channels in the thylakoid membrane dissipate the membrane potential (Δψ) component to allow for a higher fraction of pmf stored as a proton concentration gradient (ΔpH). K⁺/H⁺ antiport across the thylakoid membrane via K+ EXCHANGE ANTIPORTER3 (KEA3) instead reduces the ΔpH fraction of the pmf. Thereby, KEA3 decreases nonphotochemical quenching (NPQ), thus allowing for higher light use efficiency, which is particularly important during transitions from high to low light. Here, we show that in the background of the Arabidopsis (Arabidopsis thaliana) chloroplast (cp)ATP synthase assembly mutant cgl160, with decreased cpATP synthase activity and increased pmf amplitude, KEA3 plays an important role for photosynthesis and plant growth under steady-state conditions. By comparing cgl160 single with cgl160 kea3 double mutants, we demonstrate that in the cgl160 background loss of KEA3 causes a strong growth penalty. This is due to a reduced photosynthetic capacity of cgl160 kea3 mutants, as these plants have a lower lumenal pH than cgl160 mutants, and thus show substantially increased pH-dependent NPQ and decreased electron transport through the cytochrome b ₆ f complex. Overexpression of KEA3 in the cgl160 background reduces pH-dependent NPQ and increases photosystem II efficiency. Taken together, our data provide evidence that under conditions where cpATP synthase activity is low, a KEA3-dependent reduction of ΔpH benefits photosynthesis and growth.

Palladium-Catalyzed 4-Fold Domino Reaction for the Synthesis of a Polymeric Double Switch

A palladium-catalyzed 4-fold domino reaction consisting of two carbopalladation reactions and two C-H activation reactions, followed by the introduction of an acrylate moiety, led to the tetra-substituted helical alkene A2, using the dialkyne A3 as a substrate. The alkene was copolymerized with butyl acrylate by using the reversible addition-fragmentation chain transfer polymerization (RAFT) to give the desired polymeric switch A1.

Improving zero-training brain-computer interfaces by mixing model estimators

OBJECTIVE

Brain-computer interfaces (BCI) based on event-related potentials (ERP) incorporate a decoder to classify recorded brain signals and subsequently select a control signal that drives a computer application. Standard supervised BCI decoders require a tedious calibration procedure prior to every session. Several unsupervised classification methods have been proposed that tune the decoder during actual use and as such omit this calibration. Each of these methods has its own strengths and weaknesses. Our aim is to improve overall accuracy of ERP-based BCIs without calibration.

APPROACH

We consider two approaches for unsupervised classification of ERP signals. Learning from label proportions (LLP) was recently shown to be guaranteed to converge to a supervised decoder when enough data is available. In contrast, the formerly proposed expectation maximization (EM) based decoding for ERP-BCI does not have this guarantee. However, while this decoder has high variance due to random initialization of its parameters, it obtains a higher accuracy faster than LLP when the initialization is good. We introduce a method to optimally combine these two unsupervised decoding methods, letting one method's strengths compensate for the weaknesses of the other and vice versa. The new method is compared to the aforementioned methods in a resimulation of an experiment with a visual speller.

MAIN RESULTS

Analysis of the experimental results shows that the new method exceeds the performance of the previous unsupervised classification approaches in terms of ERP classification accuracy and symbol selection accuracy during the spelling experiment. Furthermore, the method shows less dependency on random initialization of model parameters and is consequently more reliable.

SIGNIFICANCE

Improving the accuracy and subsequent reliability of calibrationless BCIs makes these systems more appealing for frequent use.

The Rotational Zeeman Effect in Fluorobenzene and the Molecular Quadrupole Moment in Benzene

The rotational Zeeman effect in fluorobenzene is reinvestigated with a resolution improved by a factor of almost five to give more accurate g-tensor elements, magnetic susceptibility anisotropics and molecular electric quadrupole moments. The results fit into the pictures of a linear dependence of the out of plane molecular electric quadrupole moment, Qcc, on the number of fluorine substituents and of a linear correlation between the nonlocal (ring current) susceptibility, Χcc nonlocal, and the CNDO/2-π-electron density alternation. They lead to a gasphase molecular electric quadrupole moment in benzene, Qcc,benzene = - (28.4 ± 4.7) · 10-40 Cm2 which is slightly less negative than the value deduced from electric field-gradient birefringence experiments on dilute benzene solutions with carbon tetrachloride as solvent. A detailed description of the high resolution microwave spectrometer is given in the appendix.

Activity increase in respiratory chain complexes by rubella virus with marginal induction of oxidative stress

Mitochondria are important for the viral life cycle, mainly by providing the energy required for viral replication and assembly. A highly complex interaction with mitochondria is exerted by rubella virus (RV), which includes an increase in the mitochondrial membrane potential as a general marker for mitochondrial activity. We aimed in this study to provide a more comprehensive picture of the activity of mitochondrial respiratory chain complexes I to IV. Their activities were compared among three different cell lines. A strong and significant increase in the activity of mitochondrial respiratory enzyme succinate:ubiquinone oxidoreductase (complex II) and a moderate increase of ubiquinol:cytochrome c oxidoreductase (complex III) were detected in all cell lines. In contrast, the activity of mitochondrial respiratory enzyme cytochrome c oxidase (complex IV) was significantly decreased. The effects on mitochondrial functions appear to be RV specific, as they were absent in control infections with measles virus. Additionally, these alterations of the respiratory chain activity were not associated with an elevated transcription of oxidative stress proteins, and reactive oxygen species (ROS) were induced only marginally. Moreover, protein and/or mRNA levels of markers for mitochondrial biogenesis and structure were elevated, such as nuclear respiratory factors (NRFs) and mitofusin 2 (Mfn2). Together, these results establish a novel view on the regulation of mitochondrial functions by viruses.

A Virological Survey in Migrating Waders and Other Waterfowl in One of the Most Important Resting Sites of Germany

Wild birds are considered a potential reservoir or a carrier of viral diseases and may therefore play a role in the epidemiology of economically important or zoonotic diseases. In 2001 and 2002, a survey with special emphasis on virus isolation in migrating waders and some other birds were conducted. In one of the most important inland resting sites for migratory waterfowl, tracheal and cloacal swabs were collected from 465 waders representing 19 different species, and 165 other birds that were not captured on purpose. A total of 42 avian viruses were isolated, 34 of these were identified as paramyxoviruses (PMVs). The majority of isolates came from waders and wild ducks, and were characterized as PMV-1. In contrast, PMV-4 was found in wild ducks only, PMV-6 was mainly detected in wader species. Four avian influenza viruses (AIVs), belonging to H4 and H3 haemagglutinin subtype, were isolated from wild duck species. Furthermore, four reo-like viruses were isolated from one particular wader species for the first time. The majority of virus positive birds were <1 year old and did not show any clinical symptoms. There was no evidence for the presence of West Nile virus in these birds. These results confirm that the restricted resting sites in Western Europe must be considered as important locations for the intra- and interspecies transmission of avian viruses.

Genetic testing and private insurance--a case of "selling one's body"?

Arguments against the possible use of genetic test results in private health and life insurance predominantly refer to the problem of certain gene carriers failing to obtain affordable insurance cover. However, some moral intuitions speaking against this practice seem to be more fundamental than mere concerns about adverse distributional effects. In their perspective, the central ethical problem is not that some people might fail to get insurance cover because of their 'bad genes', but rather that some people would manage to get insurance cover because of their 'good genes'. This paper tries to highlight the ethical background of these intuitions. Their guiding idea appears to be that, by pointing to his favourable test results, a customer might make an attempt to 'sell his body'. The rationale of this concept is developed and its applicability to the case at issue is critically investigated. The aim is to clarify an essential objection against the use of genetic information in private insurance which has not yet been openly addressed in the academic debate of the topic.

Electron-vibron coupling in high-resolution X-Ray absorption spectra of organic materials: NTCDA on Ag(111)

We report additional rich fine structures in high-resolution near-edge x-ray-absorption fine structure (NEXAFS) spectra of large organic molecules using NTCDA on Ag(111) as an example. These fine structures are completely interpreted as vibronic coupling to electronic core excitations. The coupling is mode selective; predominantly one vibronic mode couples to each excitation. The fit results suggest the occurrence of a Davydov splitting, first observed for core excitons. Morphological differences substantially influence the electron-vibron coupling, indicating a strong intermolecular interaction. Thus NEXAFS becomes a more subtle probe for organic solids.

Lipid-lowering therapy and cholesterol levels following acute myocardial infarction: a German study of 5361 patients

BACKGROUND

Current studies on secondary prevention of cardiovascular events (CARE, LIPID, 4S) illustrate the necessity of an effective lipid-lowering therapy. An important part of secondary prevention is the prompt measurement of lipids following an infarct, to be able to start therapy as quickly as possible.

AIMS

This study should show the general situation in the prescription of lipid-lowering drugs in patients with acute myocardial infarction (MI) and if there are gender differences in therapy and in the lipid parameters. The second aim was to determine the therapeutical conclusions for secondary prevention made in-hospital in patients with heart attacks.

METHODS

Post-infarct lipid parameters (total cholesterol (TC), high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C), triglycerides (TG) were examined in 5361 patients within 24 hours following an acute MI. Lipid parameters from 576 patients were measured again after 1 week.

RESULTS

80.1% of men under examination and 81.9% of the women had suffered from their first MI. Only 9% of all patients were already under lipid-lowering therapy before the MI. After the MI TC and LDL-C levels decreased significantly in a time-dependent manner. Around 50% of patients received lipid-lowering drug, or the recommendation of one, during their hospital stay.

CONCLUSION

The range of TC values of the patients examined was comparable to those in the CARE and the 4S secondary prevention studies. It can therefore be assumed that the results of these studies are also applicable to Germany. Nevertheless, according to existing data, therapy with lipid-lowering drugs is currently unsatisfactory, even in secondary prevention.

Long term complications of inferior vena cava thrombosis

AIM

To evaluate the long term outcome after paediatric inferior vena cava (IVC) thrombosis.

METHODS

A combined retrospective and prospective study on infants and children with IVC thrombosis treated at Aachen and Maastricht University Hospitals between 1980 and 1999.

RESULTS

Forty patients were enrolled, including four with preceding cardiac catheterisation, 18 with central venous saphenous lines, and an additional eight with umbilical venous catheters. Six patients died within three months of diagnosis; one patient was lost to follow up. Twelve of the remaining 33 patients had suffered from limited IVC thrombosis; during follow up (for up to nine years) none showed persisting caval obstruction (successful thrombolysis, n = 2; spontaneous recanalisation, n = 10). The remaining 21 patients presented with extensive IVC thrombosis. During follow up (for up to 18 years) complete restitution was found in only four cases (one thrombolysis, two surgery, one spontaneous recanalisation). Persisting iliac and/or caval venous obstruction occurred in 17 patients, including six with thrombolysis. Varicose veins were found in 12, and post-thrombotic syndrome in seven of these cases. According to Kaplan-Meier analysis, 30% of patients with persisting venous disease will develop post-thrombotic syndrome within 10 years of the thrombotic event.

CONCLUSIONS

Infants and children with extensive IVC thrombosis are at high risk for persisting venous disease and serious long term complications. Prospective trials are urgently needed to establish effective treatment strategies and to improve long term prognosis. Central venous catheters, contributing to IVC thrombosis in the majority of cases reported here, should be inserted only if essential.

Feasibility and utility of respiratory-gated, gadolinium-enhanced T1-weighted magnetic resonance urography in children

RATIONALE AND OBJECTIVES

To evaluate the feasibility and utility of respiratory-gated, gadolinium-enhanced T1-weighted magnetic resonance (MR) urography in children.

METHODS

In a prospective study, 30 consecutive children, aged 3 weeks to 13.8 years, underwent MR urography. After intravenous injection of low-dose furosemide and gadopentetate dimeglumine, respiratory-gated, coronal, T1-weighted 3D-gradient-echo sequences were obtained at 1.5 T 5 to 30 minutes after contrast administration. Postprocessing of the data was performed using a maximum-intensity projection algorithm. In addition, precontrast half-Fourier rapid acquisition with relaxation enhancement MR urograms were obtained in 29 children.

RESULTS

Respiratory-gated, T1-weighted MR urography was successfully performed in all children without the need for sedation. Compared with the final diagnosis, prospective analysis of MR urography images revealed the correct diagnosis in 56 of 58 pelvicaliceal systems (96%). The ureteral morphology was correctly evaluated in 59 of 64 ureters (92%). The method showed limited efficiency for evaluating nonfunctioning renal units.

CONCLUSIONS

Respiratory-gated, gadolinium-enhanced T1-weighted MR urography is a feasible and effective diagnostic tool in the assessment of upper urinary tract morphology in children. It is especially useful in depicting nondilated collecting systems and ureters.

Unilateral absence of the left pulmonary artery associated with coronary-to-bronchial artery anastomosis

Unilateral absence of the pulmonary artery and bronchial-to-coronary artery anastomosis are rarely described congenital vascular anomalies. The authors report a case of a 49-year-old female presenting with both anomalies. The presenting symptoms and pertinent diagnostic imaging are described, including conventional radiographs, angiography, computed tomography, and magnetic resonance imaging, and the therapeutic options available are discussed.

[Percutaneous transjugular thrombectomy in iliocaval thrombosis-- initial experience with a newly developed 12F balloon sheath]

PURPOSE

To evaluate the feasibility of percutaneous thrombectomy for the removal of floating iliocaval thrombi using a balloon sheath.

MATERIALS AND METHODS

A newly developed balloon sheath (inner diameter: 12-F; outer diameter: 18-F) was tested in two patients with extensive iliocaval thrombosis. Mechanical thrombectomy was performed due to recurrent pulmonary embolism under therapeutic anticoagulation in antiphospholipid-antibody syndrome and, respectively, paraneoplastic thrombosis without a decrease of fresh thrombus mass in spite of pharmacological treatment. Via a transjugular access (20-F), the sheath was advanced retrogradely into the inferior vena cava. After blocking of the vessel, mechanical fragmentation was performed through the working channel coaxially, using a temporary vena cava filter as a rotating basket (max. diameter: 30 mm). Residual thrombus fragments were removed by aspiration.

RESULTS

The thrombectomy balloon sheath tested allowed a complete removal of fresh thrombi after fragmentation. In addition, older clot material was obtained. Balloon occlusion prevented the central embolization of thrombus fragments. Clinical signs indicating pulmonary embolism were not seen. The fluid loss due to aspiration was negligible.

CONCLUSIONS

The newly developed 12-F balloon sheath proved to be efficient for the extraction of large thrombi. Balloon occlusion safely prevented central embolization of thrombus fragments proximal to the sheath.

Recanalization of thrombosed dialysis access with use of a rotating mini-pigtail catheter: follow-up study

PURPOSE

To evaluate the feasibility, efficacy, and safety of mechanical thrombectomy of occluded dialysis access with use of a rotating mini-pigtail catheter.

MATERIALS AND METHODS

Thrombus was fragmented by mechanical action of the rotating pigtail tip (5-mm diameter), while the guide wire exited a sidehole at the pigtail curvature and served as a fixed rotation axis. Twenty-six procedures were performed in 22 patients (12 men, 10 women; mean age, 55.5 years). Native fistulas were treated in 15 instances, polytetrafluoroethylene (PTFE) grafts were treated in 11 instances. Average occlusion time was 20 hours +/- 13 (range, 5-46 hours), average occlusion length was 25.6 cm +/- 10.1 (range, 6-45 cm). Thrombus fragmentation was followed by balloon angioplasty of underlying stenoses.

RESULTS

In all 26 procedures, the dialysis access was successfully declotted with subsequent dialysis using the access (clinical success rate, 100%). Handling of the mini-pigtail catheter was simple and rapid, regardless of whether a graft or a native fistula was treated. Average duration of the intervention was 118 minutes +/- 30. Mean primary patency was 165 days +/- 167. Primary patency rate was 82% at 30 days, 65% at 3 months, and 47% at 6 months. There was no evidence of complications due to the thrombus fragmentation procedure.

CONCLUSION

The results suggest that declotting of occluded dialysis grafts and fistulas with the mini-pigtail catheter is as effective and safe as other more established percutaneous therapies. It may serve as an easy-to-handle, low-budget alternative to current thrombectomy devices.

Reduction of contrast material dose and artifacts by a saline flush using a double power injector in helical CT of the thorax

OBJECTIVE

Our objective was to evaluate a combined method of contrast material bolus followed by saline solution flush for thoracic helical CT and statistical comparison with a uniphasic injection protocol.

MATERIALS AND METHODS

Fifty patients underwent helical CT of the thorax using 60 ml of contrast material (370 mg I/ml) followed by flushing with 30 ml of physiologic saline solution. These 50 patients had been examined before using our previous protocol, 75 ml of the same contrast material without a subsequent saline solution. Mean attenuation values for both protocols were measured in the superior vena cava, the pulmonary trunk, and the ascending aorta. Image artifacts and mediastinal and hilar depiction were graded and compared.

RESULTS

Mean attenuation values in the superior vena cava were considerably higher in the regimen without saline solution flush (459 H versus 352 H) and in the pulmonary trunk and the ascending aorta were almost identical for both protocols. Injection of saline solution diminished surrounding artifacts (p = 0.001). Grading results for the evaluation of mediastinal and hilar structures were not significantly different in the two protocols (p = 0.564).

CONCLUSION

Injection of contrast material followed by a saline solution bolus using a double power injector when performing thoracic helical CT allows a 20% reduction of contrast material volume to 60 ml with a similar degree of enhancement. In addition, perivenous artifacts in the superior vena cava are significantly reduced.

[Catheter tract embolization after percutaneous transhepatic biliary intervention]

PURPOSE

Evaluation of the feasibility and efficacy of an embolization technique of the transhepatic tract after intervention, in order to prevent peritoneal bile leakage.

PATIENTS AND METHOD

Twenty patients (mean age 62 yr) with malignant (17 cases) or benign (three cases) biliary obstruction were treated by percutaneous transhepatic biliary intervention (stent implantation in 17 cases). Mean diameter of the transhepatic tract was 3.2 +/- 0.6 mm. Tract embolization was performed 3.0 +/- 4.0 days after intervention by injecting Histoacryl-Lipiodol via a coaxial catheter-sheath system.

RESULTS

Tract embolization was feasible in all cases and resulted in a continuous cast of the catheter tract. There were no signs or symptoms of peritonitis in any of the patients. One patient with stent occlusion developed a biliocutaneous fistula via the former tract after 60 days.

CONCLUSION

After embolization of fresh transhepatic tracts there were no signs of leakage during follow-up of the patients. One case with biliocutaneous fistula shows that prevention of leakage is not permanent if biliary reobstruction occurs.

[Panorama ultrasound of the spinal canal with determination of the level of the conus medullaris in newborn infants and infants]

PURPOSE

To evaluate the utility of panoramic ultrasound in visualizing the spinal canal and the conus medullaris level in neonates and young infants.

METHOD

30 children (aged 2 days to 5 months, 2058-6660 g, 41-57 cm) underwent examination of the spinal canal. The children were examined by a single, continuous 9.0 MHz transducer movement from the cervico thoracic spine to the coccyx. A dedicated computer processor produced an extended field of view image in realtime mode.

RESULTS

With panoramic ultrasound coverage of the thoracic, lumbar and sacral spinal canal on one extended image was possible. Visualization of the spinal cord, the conus medullaris level, the subarachnoid space, the cauda equina and the tip of the dural sac was easily accomplished in each child. An average of four trials was necessary to obtain an image of sufficient diagnostic quality. The conus level ranged from L1 to L3, the tip of the dural sac was localized at S1 to S3.

CONCLUSIONS

Panoramic ultrasound offers nearly complete visualization of the spinal canal in children on one single extended field of view image. The conus medullaris level and the tip of the dural sac can easily be localized.

[A case-based and multi-media computer learning program on the topic of myocardial infarct, angina pectoris and mitral valve stenosis]

BACKGROUND

Principles in the field of cognitive psychology and problem-based learning together with recent progress in multimedia technologies are providing the basis for the development of case-based and computer-assisted learning systems. With reference to the information-overload of theoretical and factual knowledge in medical education these programs can be an efficient tool to satisfy the current need for new, practical, skill-related forms of knowledge transfer.

METHODS

Apple-Macintosh Computers were selected to develop interactive, multimedia patient-simulations on mitral stenosis, angina pectoris and myocardial infarction.

INSTRUCTIONAL AIM AND CONTENTS

The user acquires knowledge and skills about the leading symptoms, differential diagnoses, the use and analysis of laboratory examinations and the process of diagnostic reasoning while working through the computer-simulated cases.

PEDAGOGICAL DESIGN AND CONCLUSION

Important pedagogical principles associated with computer-assisted learning were employed in the program. Clinical situations can be simulated repeatedly and for every student in an authentic manner. Therefore the program can serve as a preparation for and a supplement to practical clinical education. Compared to conventional teaching media the development of instructional multimedia software requires a tremendous amount of time and resources. Thus, controlled studies are important to objectify the overall advantages such programs can have.

[Preoperative assessment of tumor aggressiveness in localized prostatic carcinoma]

In 106 consecutive patients with localized prostate cancer digital rectal examination (DRE), preoperative prostate-specific antigen (PSA) determination and results of systematic sextant biopsies (TRUS 6Bx) of the prostate were analyzed for their value in the estimation of the aggressivity of tumors. In all patients with negative pelvic lymph nodes radical retropubic prostatectomy was performed. Tumor aggressiveness was defined as capsular penetration (pT2 versus pT3) or positive surgical margins in patients with pT3 tumors. Neither DRE nor preoperative PSA level was helpful in predicting capsular penetration or positive surgical margins. However, the number of positive core biopsies and the identification of Gleason 4 or 5 tumors within positive biopsy specimens correlated with capsular penetration and positive surgical margins. These results can be used to create a score, based on DRE, PSA, TRUS 6Bx, and Gleason 4 or 5, that might be helpful in predicting tumour aggressivity in patients with localized prostate cancer.

[Perioperative and postoperative complications of pelvic lymphadenectomy and radical prostatectomy in 320 consecutive patients]

To examine the intra- and postoperative morbidity of radical retropubic prostatectomy we analyzed the first 320 consecutive patients with clinical stages T1b, T2a-c and negative lymph nodes by frozen section. Patient age varied from 42 to 75 years (mean 63.5 years). In 74.7% the estimated blood loss was less than 1500 ml. With a preoperative autologous blood collection program the intraoperative blood requirement for homologous blood units was only 15%. Intraoperative complications included rectal injuries with vesical rectal fistulas in 2.5% and ureteral injuries in 1.6%. Within the perioperative period the mortality rate was 0.9%. At 12 months after surgery 199 of 218 men (90.9%) were continent, 5.1% had minimal urinary incontinence, and only 4.6% had urinary incontinence grade III. Postoperatively, PSA (prostate-specific antigen) decreased to < 0.5% in 90.4% of the patients after radical prostatectomy. At 12 months after operation PSA was < 0.5 ng/ml in 83.4%. We conclude that radical retropubic prostatectomy is a safe procedure for the curative treatment of localized prostate cancer.

In vivo system to detect long-term continuous release of bioactive interleukin-2 by immunopharmacological depot preparations in nude mice with human tumors

For continuous release of cytokines for local application at tumor sites, we developed depot preparations consisting of a carrier substance (ethylene vinyl acetate copolymer) and either natural interleukin-2 (nIL-2) at 5 x 10(5) BRMP U or natural interferon-alpha (nIFN alpha) at 3 x 10(5) IU. We transplanted human tumors in nude mice and placed depot preparations next to the tumors to confirm the in vivo long-term biological activity of the depots according to the ability of IL-2 to inhibit growth of the tumors. Five different human tumors were used. Mice with each tumor were divided into groups of six to eight receiving different treatments: control (no treatment), human serum albumin, but no cytokine, IL-2 depot, IFN alpha depot and IFN alpha plus IL-2 depot. After proven in vivo tumor growth, these depot preparations were implanted subcutaneously directly at the tumor sites. Tumor growth was significantly reduced by IL-2 and IFN alpha plus IL-2 for 3 weeks after depot implantation. Complete tumor remission was not achieved. IFN alpha alone did not influence tumor growth. Our data show that the nude mouse is a valuable model for testing biological activity and release time of IL-2 depot preparations in vivo.

[Treatment of rectal injuries with vesicorectal fistulization in radical prostatectomy]

In the literature many different ways are described of treating rectal injured during radical prostatectomy. Therefore, following this procedure we evaluated our patients with rectal injuries. Rectal injury occurred in 16 of 299 patients with radical prostatectomy for treatment of localized prostate cancer. Seven developed a vesicorectal fistula, 4 of whom needed no further surgical intervention. Only 3 (1%) had to undergo an additional operation.

[Morphologic results of 106 consecutive radical prostatectomy specimen of patients with clinical stage B1-B3 (T2a-c) and histologically negative lymph nodes in the fossa obturatoria]

The morphologic results recorded in 106 consecutive radical prostatectomy specimens from patients with clinical stage B1-B3 (T2a-c) are presented. All specimens had inked margins and were subjected to morphometric work-up using a 3-mm step section technique. In only 39 (37%) was the tumour confined to a single organ (pT2); 67 (63%) were stage pT3; 40 (37.7%) had only capsular penetration; and 27 (25.4%) had seminal vesicle invasion. In 33 (31.1%) the surgical margin was positive. None of those with pathological stage pT2 had a positive margin. Of the 40 patients with pathological stage pT3a+b, 19 (47.5%) had a positive margin. Of the 27 patients with seminal vesicle invasion (pT3c), 14 (51.8%) had a positive margin. Specimens with only unilateral seminal vesicle invasion or none at all had positive surgical margins in only 25% and 24% of cases, in contrast to those with bilateral seminal vesicle invasion, in which the rate for positive margins was 73%. The mean tumour volume was 8.1 cm3 (0.12-50.13 cm3). There were 9 (8.4%) tumours with a volume < 0.5% cm3 while 62 specimens contained > 0.5 cm3 Gleason 4 and Gleason 5 tumours. Our analysis shows a good correlation of the positive margin rate with tumour volume and especially with volume of the high-grade tumor.

Immunohistochemical detection of p53 protein in human prostatic cancer

Tissue sections from 73 radical-prostatectomy specimens were studied immunohistochemically for the presence of p53 protein. In seven specimens numerous tumor cells showed a strong nuclear immunostaining. An additional 27 revealed a more discrete and focal accumulation of p53 protein. Comparison of the pathologic characteristics of the p53-negative and -positive groups showed that the presence of p53 protein closely correlated with more advanced tumor stages (p < 0.00001), with higher primary (p = 0.0004), combined (p < 0.0001) and worst (p < 0.0001) Gleason grades, and with larger total (p = 0.0001) and high-grade (p < 0.0001) tumor volumes. No staining was found in areas of benign hyperplasia or in well-differentiated tumor zones. Our results suggest that the accumulation of p53 protein to immunohistochemically detectable concentrations is not a feature of low-grade cancer. This finding implies that abnormal p53 accumulation might be involved in the process of prostatic cancer progression.

Systematic biopsies and digital rectal examination to identify the nerve-sparing side for radical prostatectomy without risk of positive margin in patients with clinical stage T2, N0 prostatic carcinoma

OBJECTIVES

Systematic biopsies and digital rectal examination were used to identify the nerve-sparing side for radical prostatectomy without risk of positive margin in patients with clinical Stage T2, N0 prostatic carcinoma.

METHODS

We studied specimens from 73 consecutive radical prostatectomies by the 3 mm step-section technique for clinical Stage T2a, T2b (n = 57), and T2c (n = 16) tumors to see whether digital rectal examination or the use of 6 systematic biopsies could identify the side where nerve-sparing could be used without risk of positive margin.

RESULTS

In 39 of the 57 (68%) patients with clinical Stage T2a, T2b 3 contralateral biopsies were negative. Only in these 39 patients was unilateral nerve-sparing done on the biopsy-negative side. None of these 39 specimens had a positive margin at this nerve-sparing side. The other 18 (32%) of the 57 patients with clinical T2a, T2b tumors had positive biopsies on the contralateral side of the palpable tumor; no nerve-sparing was done in this group. Of the 18 specimens, only 5 (28%) had full capsular penetration on the contralateral side in the area of the nerve bundle and thus the potential risk of positive margins if contralateral nerve-sparing would have been done. That could mean that 13 patients of these 18 (23% of the whole group of the 57 patients with T2a, T2b lesions) were unnecessarily excluded from the unilateral contralateral nerve-sparing.

CONCLUSIONS

We conclude that unilateral contralateral nerve-sparing can be done safely in patients with T2a, T2b lesions without risk of positive margins when three biopsies on the contralateral side are negative. We calculate that by such strict selection criteria for unilateral contralateral nerve-sparing technique only one of five patients with clinical unilateral tumors will be excluded unnecessarily from the nerve-sparing technique.

Frequency and distribution of numerical chromosomal aberrations in prostatic cancer

Prostatic cancer frequently shows striking morphological heterogeneity and multifocal growth. To better understand the relationship between chromosomal changes and pathological characteristics, 31 routinely processed radical prostatectomy specimens were studied for the presence of numerical chromosomal aberrations by in situ hybridization with centromeric nucleic acid probes specific for chromosomes 7, 10, 17, X, and Y. In 24 of the cases preoperative core biopsy specimens were available and were examined with the probe for the X chromosome. In eight of the prostatectomy specimens chromosome numbers consistent with a normal male karyotype were found. Three cases, besides diploid chromosome numbers, showed a focal doubling of hybridization signals, consistent with tetraploidy. The other 20 cases displayed numerical chromosomal aberrations to a various degree. In this group the appearance of numerical chromosomal aberrations often showed considerable local heterogeneity, generally coinciding with morphological dedifferentiation, and was significantly correlated with tumor stage (P = .0004) as well as primary (P = .0068), worst (P = .0002), and combined (P < .0001) Gleason grades, total tumor volume (P = .0448), and the volume of tumor with Gleason grades 4 or 5 (P < .0001). In four of the 24 core biopsy specimens no residual tumor tissue was left for cytogenetic examination. In the remaining 20 biopsy specimens the presence or absence of numerical changes matched the result obtained on the corresponding prostatectomy specimen. We conclude that in prostatic cancer the presence of numerical chromosomal aberrations is associated with advanced disease. Especially in low differentiated tumors local heterogeneity in 2 chromosome numbers can be very marked. It is possible to forecast the presence or absence of numerical chromosomal changes on preoperative core biopsy specimens.

[Significance of numerical chromosome aberrations in prostate cancer]

Thirty-one routinely processed radical prostatectomy specimens were examined for the presence of numerical chromosomal aberrations by in situ hybridization with centromeric nucleic acid probes specific for chromosomes 7, 10, 17, X, and Y. In eight of the prostatectomy specimens, chromosome numbers consistent with a normal male karyotype were found. Three cases, in addition to diploid chromosome numbers, showed a focal doubling of hybridization signals, consistent with tetraploidy. The other 20 cases displayed more or less marked numerical chromosomal aberrations. In this group, the appearance of numerical chromosomal aberrations often showed considerable local heterogeneity and was significantly correlated with tumor stage, Gleason grades, and tumor volume. We conclude that in prostatic cancer the presence of numerical chromosomal aberrations is associated with advanced disease. Especially in low differentiated tumors local heterogeneity in chromosome numbers can be very marked.

Numerical chromosomal aberrations in prostate cancer: correlation with morphology and cell kinetics

Eleven routinely processed radical prostatectomy specimens were studied for the presence of numerical chromosomal aberrations by means of in situ hybridization with nucleic acid probes specific for chromosomes 7, 10, 17, X, and Y. Cytogenetic information was correlated with morphology, tumour stage and volume as well as with cell kinetics, the latter being assessed by immunohistochemistry with antibodies raised against the proliferative cell nuclear antigen (PCNA) and against a formalin-resistant epitope of the Ki-67 antigen, MIB 1. In 5 of 11 cases, numerical aberrations of at least one chromosome were found. The cases with normal chromosome numbers were those with the smallest volumes of Gleason grade 4 and/or 5 tumour (mean 0.5 cm3) and represented tumours restricted to the prostate. Tumours with aberrations in the number of detected chromosomes showed advanced stages and large volumes of high-grade tumour (mean 12.5 cm3). All 4 tumours with positive surgical margins were recruited from a group with marked local heterogeneity in chromosome numbers. Immunostaining with MIB 1 and PCNA was most intense in areas of high-grade tumour and was positively correlated with the emergence of chromosomal aberrations. The data suggest that the appearance of numerical chromosomal aberrations in prostate cancer coincides with aggressive tumour behaviour and could be used as an additional prognostic marker.

Peptidyl-prolyl cis-trans isomerase activity as studied by dynamic proton NMR spectroscopy

Recently the identity of the peptidyl-prolyl cis-trans isomerase (PPIase), which accelerates the cis/trans isomerization of prolyl peptide bonds and cyclophilin, the binding protein for the immunosuppressive drug Cyclosporin A (CsA), was discovered. The PPIase catalysis toward the substrate Suc-Ala-Phe-Pro-Phe-pNA has been studied by 1H NMR spectroscopy. Using the bandshape analysis technique the rate of interconversion between the cis and trans isomers of the substrate could be measured in the presence of PPIase and under equilibrium conditions. The acceleration is inhibited by equimolar amounts of CsA. The results provide evidence that the PPIase catalysis is more complex than a simple exchange between two states.

Conformational analysis of the tetrapeptide Pro-D-Phe-Pro-Gly in aqueous solution

Conformational investigations of the tetrapeptide Pro-D-Phe-Pro-Gly in water solution were carried out by 1H and 13C NMR spectroscopy. The internal proline residue allows for the possibility of cis/trans isomerization about the D-Phe-Pro peptide bond resulting in two conformational isomers. The major isomer was identified as the trans isomer. The pH-dependence of the cis/trans equilibrium supports an additional stabilisation of the trans isomer by an intramolecular ionic interaction between the amino- and carboxy-terminus in the zwitterionic state. Based on 13C spin-lattice relaxation times (T1), different pyrrolidine ring conformations of Pro1 and Pro3 could be determined. By combination of several NMR data (vicinal coupling constants 3JN alpha, temperature dependence of the NH chemical shifts, differences in the chemical shifts between the beta and gamma carbons of the proline residues) and energy minimization calculations, a type II' beta-turn should contribute considerably to the overall structure of the trans isomer.

[Fluoride poisoning caused by rhubarb fruit juice--case report]

In the course of industrial-scale manufacture of unfermented rhubarb fruit juice, the deacidifying agent CaCl2 was confused with the disinfectant NH4HF2. Hence, fluoride in a quantity of up to 0.6 g/l was present in the unfermented fruit juice. Signs of acute fluoride poisoning were therefore seen after ingestion of the rhubarb juice. The incident as well as the steps taken by the relevant control authorities are described in detail.

[Histamine poisoning following consumption of fried fish]

Cases of food poisoning after consumption of fried fish in marinades are often caused by increased content of histamine. From 1973 to 1988 28 outbreaks in groups of persons with symptoms of histamine poisoning were analysed in the district of Dresden (GDR). The content of histamine most commonly exceeded the tolerance limit of 300 mg/kg fried fish.

Dissociation between in vivo and in vitro measurements of converting enzyme activity after chronic oral treatment with captopril in rats

Intravenous administration of captopril (20 micrograms) produced inhibition of angiontensin I pressor responses by 70 percent and of plasma-converting enzyme activity by 72 percent. Oral treatment with captopril (50 mg/kg/day) for 1 week inhibited angiotensin I pressor responses more (84 percent) than plasma-converting enzyme activity (23 percent). Four month oral treatment of normotensive and spontaneously hypertensive rats with captopril (50 mg/kg/day) led to 68 and 71 percent inhibition of angiotensin I pressor responses, but produced increases in plasma-converting enzyme activity of 123 and 94 percent, respectively. In spontaneously hypertensive rats, elevated converting enzyme activity in the medulla oblongata was measured after this treatment. It is concluded that plasma-converting enzyme activity measurements can be dissociated from the in vivo inhibition of converting enzyme. Chronic oral captopril treatment results in an induction of converting enzyme biosynthesis not only in peripheral tissue but also in the brain.

Plasma-converting enzyme activity does not reflect effectiveness of oral treatment with captopril

Intravenous Captopril (20 microgram) in rats produced similar inhibition of the pressor responses to intravenous ANG I (70%) and of plasma-converting enzyme activity (CEA) measured fluorometrically (72%). One week oral treatment with Captopril (50 mg/kg per day) inhibited ANG I pressor responses more (84%) than plasma CEA (23%). Four-month oral treatment of normotensive and spontaneously hypertensive rats with Captopril (50 mg/kg per day) led to a 68% and 71% inhibition of the ANG I pressor responses, but to a 123% and 94% increase of plasma CEA, respectively. Thus, plasma CEA measurements can be dissociated from the in vivo inhibition of converting enzyme (CE). Chronic oral Captopril treatment induces CE biosynthesis.

[Enzymatic determination of glucose and saccharose in selected dietetic foods]

The need to enlarge the offer of dietetic foods requires more sensitive methods for the determination of certain food constituents. Thus, the exact estimation of glucose and saccharose in foods for diabetics is of particular importance. The enzymatic determination of the two sugars is suited for these purposes. The enzymatic method used by the authors is described. On the basis of results from their own investigations, the authors compare the values yielded by the enzymatic method with those obtained by means of the Luff-Schoorl procedure. The differences observed were more or less great from one food to another.