Crystallization induced by multiple seeds: dynamical density functional approach

Using microscopic dynamical density functional theory, we calculate the dynamical formation of polycrystals by following the crystal growth around multiple crystalline seeds imposed to an undercooled fluid. Depending on the undercooling and the size ratio as well as the relative crystal orientation of two neighboring seeds, three possibilities of the final state emerge, namely no crystallization at all, formation of a monocrystal, or two crystallites separated by a curved grain boundary. Our results, which are obtained for two-dimensional hard disk systems using a fundamental-measure density functional, shed new light on the particle-resolved structure and growth of polycrystalline material in general.

Effects of the interaction range on structural phases of flexible polymers

We systematically investigate how the range of interaction between non-bonded monomers influences the formation of structural phases of elastic, flexible polymers. Massively parallel replica-exchange simulations of a generic, coarse-grained model, performed partly on graphics processing units and in multiple-gaussian modified ensembles, pave the way for the construction of the structural phase diagram, parametrized by interaction range and temperature. Conformational transitions between gas-like, liquid, and diverse solid (pseudo) phases are identified by microcanonical statistical inflection-point analysis. We find evidence for finite-size effects that cause the crossover of "collapse" and "freezing" transitions for very short interaction ranges.

Development and validation of the pressure surge computer code DYVRO mod. 3

Pressure fluctuations are generated in pipeline systems, when a fluid is rapidly accelerated or decelerated by fast closing or opening a valve, pump trip or start, breaking of pipes etc. TUEV NORD SysTec GmbH & Co. KG performs calculations of pressure surges in power plants and especially in nuclear power plants for many years. For this reason TUEV NORD has developed and qualified the pressure surge computer code DYVRO. This contribution describes in detail the actual code version DYVRO mod. 3 that has been modified with regard to the system of partial differential equations and the numerical scheme. Also the validation against representative experiments like the Simpson's experiment and an experiment at the Cold Water Hammer Test Facility CWHTF is shown. Results of DYVRO calculations are afterwards compared with results of own and external simulations with system codes (ATHLET and RELAP5) and with the pressure surge code WAHA. For this purpose the outcome of the EU project WAHALOADS that was supported within the 5th framework programme has been used.

Experiments and comparing calculations on thermohydraulic pressure surges in pipes

Modelling of pressure surges in power plant pipe systems means to carefully judge and classify the relevant variables. A decision must be made, whether the numerous effects that can occur during a transient event, should be modelled. One main point is to determine if fluid structure interaction (FSI) is important for the special situation/scenario. Also unsteady friction and degassing of dissolved gases can occur. But with each model more sources of errors are introduced into the mathematical system, such as uncertainty about bearing clearance, determination of fixing points/stiffness/spring constants, determination of friction coefficients and damping parameters, uncertainty about the amount of non-condensables in the liquid, dynamics of de-aeration processes and unsteady friction coefficients. Another complicated problem is the definition of boundaries, like specifications of pumps, valves, fittings, etc. It is obvious that a combination of all uncertainties may lead to quite uncertain predictions and must therefore be very carefully taken into account. Within this contribution, valve-closing experiments of different initial temperature and system pressure at Fraunhofer test rig PPP are presented. Two scenarios are modelled using different assumptions and model depths and the simulation results are compared with experimental data.

1D Models for Condensation Induced Water Hammer in Pipelines

Condensation induced water hammer (CIWH) are caused by contact of steam and subcooled water. Thus, modeling the direct contact condensation is a crucial step towards the simulation of condensation induced water hammer with 1D pressure surge codes. Therefore, also the TÜV NORD SysTec GmbH & Co. KG inhouse pressure surge code DYVRO has been equipped with a new contact condensation model. The validation of DYVRO against an experiment dealing with CIWH is presented in this contribution.

Rhombic preordering on a square substrate

A competition of incommensurate symmetries occurs whenever a system is forced to conform to an ordering that is different from the intrinsically preferred structure of the system itself. As a model system of such a competition, we study the rivalry between the triangular ordering of hard disks and the square symmetry induced by a periodic square substrate. By using density functional theory as well as Monte Carlo computer simulations, we determine the full phase behavior for the case of one particle per minimum. We observe a rhombic preordering structure preceding the hexagonal solid as a direct consequence of the competing symmetries. Furthermore, the square-rhombic transition is reentrant with increasing substrate interaction. Our predictions can be verified in experiments of colloids in laser fields.

A randomised multicentre phase II study with cisplatin/docetaxel vs oxaliplatin/docetaxel as first-line therapy in patients with advanced or metastatic non-small cell lung cancer

Background:

This study was designed to compare cisplatin/docetaxel with oxaliplatin/docetaxel in patients with advanced and metastatic non-small lung cancer as a first-line treatment.

Methods:

Patients were randomly assigned to receive either cisplatin 75 mg m⁻² and docetaxel 75 mg m⁻² every 3 weeks or oxaliplatin 85 mg m⁻² and docetaxel 50 mg m⁻² every 2 weeks. The primary end point was response rate, and secondary end points were toxicity, time to progression and overall survival.

Results:

A total of 88 patients (median age: 65 (39–86) years; stage IV: 93%) were randomly assigned. Response rate (complete and partial response) was 47% (95% CI: 33–61%) in the cisplatin/docetaxel arm and 28% (95% CI: 17–43%) in the oxaliplatin/docetaxel arm (P=0.118). There was no significant difference in time to progression (6.3 vs 4.9 months, P=0.111) and median overall survival (11.6 vs 7.0 months, P=0.102) with cisplatin/docetaxel vs oxaliplatin/docetaxel, although slight trends favouring cisplatin were seen. Oxaliplatin/docetaxel was associated with significantly less (any grade) renal toxicity (56% vs 11%), any grade fatigue (81% vs 59%), complete alopecia (76% vs 27%), any grade leukopenia (84% vs 61%) and grade 3/4 leukopenia (44% vs 14%) and neutropenia (56% vs 27%).

Conclusion:

Oxaliplatin/docetaxel has activity in metastatic non-small cell lung cancer, but it seems to be inferior to cisplatin/docetaxel.

Tripartite mass transfer model: development, implementation in DYVRO, verification and validation

For the realistic simulation of condensation induced water hammer (CIWH) in horizontal pipes resulting from the contact of steam at sub-cooled water, an appropriate model for the mass and energy transfer due to phase change is needed. For this purpose the tripartite mass transfer (TMT) model has been developed that is introduced in the present paper. The TMT model is based on the assumption of isentropic processes and accounts for vaporization due to flashing, condensation due to isentropic decompression (homogenous condensation) and direct contact condensation at the phase interface. The TMT model shall be considered as a frame for sub-models which may be arranged for the three above-mentioned phase change phenomena. The TMT model has been implemented in the one-dimensional two-phase pressure surge code DYVRO mod 3. A verification and validation procedure was performed based on experiments at test facilities in Oberhausen (PPP), Rossendorf (CWHTF) and Budapest (PMK-2).

7th SOSORT consensus paper: conservative treatment of idiopathic & Scheuermann's kyphosis

: Thoracic hyperkyphosis is a frequent problem and can impact greatly on patient's quality of life during adolescence. This condition can be idiopathic or secondary to Scheuermann disease, a disease disturbing vertebral growth. To date, there is no sound scientific data available on the management of this condition. Some studies discuss the effects of bracing, however no guidelines, protocols or indication's of treatment for this condition were found. The aim of this paper was to develop and verify the consensus on managing thoracic hyperkyphosis patients treated with braces and/or physiotherapy.

METHODS

The Delphi process was utilised in four steps gradually modified according to the results of a set of recommendations: we involved the SOSORT Board twice, then all SOSORT members twice, with a Pre-Meeting Questionnaire (PMQ), and during a Consensus Session at the SOSORT Lyon Meeting with a Meeting Questionnaire (MQ).

RESULTS

There was an unanimous agreement on the general efficacy of bracing and physiotherapy for this condition. Most experts suggested the use of 4-5 point bracing systems, however there was some controversy with regards to physiotherapeutic aims and modalities.

CONCLUSION

The SOSORT panel of experts suggest the use of rigid braces and physiotherapy to correct thoracic hyperkyphosis during adolescence. The evaluation of specific braces and physiotherapy techniques has been recommended.

Ground-state properties of tubelike flexible polymers

In this work we investigate the structural properties of native states of a simple model for short flexible homopolymers, where the steric influence of monomeric side chains is effectively introduced by a thickness constraint. This geometric constraint is implemented through the concept of the global radius of curvature and affects the conformational topology of ground-state structures. A systematic analysis allows for a thickness-dependent classification of the dominant ground-state topologies. It turns out that helical structures, strands, rings, and coils are natural, intrinsic geometries of such tubelike objects.

A phase III trial of topotecan and whole brain radiation therapy for patients with CNS-metastases due to lung cancer

Brain metastases represent an important cause of morbidity in patients with lung cancer and are associated with a mean survival of less than 6 months. Thus, new regimens improving the outcome of these patients are urgently needed. On the basis of promising data raised in a phase I/II trial, we initiated an open, randomised, prospective, multicentric phase III trial, comparing whole brain radiation therapy (WBRT; 20 × 2 Gy) alone with WBRT+topotecan (RCT; 0.4 mg m⁻² day⁻¹ × 20). A total of 320 patients with CNS-metastases due to SCLC or NSCLC were projected. The primary end point was overall survival, whereas second end points were local response and progression-free survival. However, until the cutoff date of study completion (i.e., a study duration of 34 months), only a total of 96 (RCT:47, WBRT:49) patients had been recruited, and so an analysis was performed at that time point. Although the numbers of grade 3/4 non-haematological toxicities (besides alopecia 115 (RCT/WBRT: 55 out of 60) were evenly distributed, the 25 haematological events occurred mainly in the combined treatment arm (24 out of 1). Local response, evaluated 2 weeks after treatment, was assessable in 44 (RCT/WBRT: 23 out of 21) patients, showing CR in eight (3 out of 5), PR in 17 (11 out of 6), SD in 14 (8 out of 6) and PD in five (1 out of 4) patients (all differences n.s.). Neither OAS (RCT/WBRT: median (days)): 87 out of 95, range 3–752/4–433; HR 1.32; 95% CI (0.83; 2.10)) nor PFS (median (days)): 71 out of 66, range, 3–399/4–228; HR 1.28, 95% CI (0.73; 2.43) differed significantly. On the basis of these results and the slow recruitment, a continuation of the study did not seem reasonable. The available data show no significant advantage for concurrent radiochemotherapy for patients with lung cancer; however, the recruited number of patients is too low to exhibit a small advantage of combined treatment.

Efficient parallel tempering for first-order phase transitions

We present a Monte Carlo algorithm that facilitates efficient parallel tempering simulations of the density of states g(E) . We show that the algorithm eliminates the supercritical slowing down in the case of the Q=20 and Q=256 Potts models in two dimensions, typical examples for systems with extreme first-order phase transitions. As recently predicted, and shown here, the microcanonical heat capacity along the calorimetric curve has negative values for finite systems.

A phase III trial of topotecan and whole brain radiation (WBRT) therapy for patients with CNS metastases due to lung cancer

2049

Background: Brain metastases represent an important cause of morbidity in patients (pts) with lung cancer and are associated with a mean survival of less than 6 months. Thus studies to improve outcome are urgently needed. Methods: Based on promising data raised in a phase I/II trial, in which WBRT was combined with topotecan (ASCO #444, 2003), we initiated an open, randomized, prospective, multicentric phase III trial, comparing WBRT (20 x 2 Gy; arm A) alone with WBRT + topotecan (0.4 mg/m2/d x 20; arm B). 320 pts with CNS-metastases due to SCLC or NSCLC were projected. Primary endpoint was overall survival (OS), secondary endpoints were local response and progression-free survival (PFS). However, since until the cut off date of study completion (i.e. a study duration of 34 months) only a total of 96 (A: 49, B: 47) pts have been recruited, an interim analysis was performed at that time point. Results: The demographic data (ø age 59 (34–75), 64% male, 66% NSCLC, mainly (64%) ECOG 0–1, extracerebral metastases in 75% and more than 4 cerebral lesions in 26% of pts) were evenly distributed in the two groups. Also the rate of grade 3/4 toxicities (besides alopecia 115 non-hematological (A/B: 60/55) and 43 hematological events (18/25)) did not differ remarkably between the arms. Early deaths (within 6 weeks after recruitment) occurred in 24% of the patients (A/B: 30%/18%), mainly due to tumor progression. Local response, evaluated 2 weeks after treatment, was assessable in 44 (A/B: 21/23) pts, showing CR in 8 (5/3), PR in 17 (6/11), SD in 14 (6/8) and PD in 5 (4/1) pts (all differences n.s.). Neither PFS (median A/B; days: 76/97, range, 24–251/20–428) nor OS (median A/B; days: 95/87, range 4–433/3–752) differed significantly (Cox-Mantel test; p=0.82 and 0.43, respectively). Conclusions: The available data, gained from the only phase III trial regarding concurrent WBRT and topotecan, show no significant advantage for concurrent radiochemotherapy for patients with lung cancer, however due to the limited number of recruited patients a possible small advantage of a combined treatment could not be demonstrated. Based on these results and the slow recruitment a continuation of the study did not seem reasonable.

No significant financial relationships to disclose.

Ring polymer simulations with global radius of curvature

We simulate three-dimensional flexible off-lattice ring polymers of length L up to L=4000 for various values of the global radius of curvature Rgrc=0.25 , 0.48, and 1.0 and Rgrc=2.0 . We utilize two different ensembles: one with a delta -function constraint on the radius, and the other with a theta -function. For both cases the global radius of curvature provides a valid regularization of polymers with thickness D=2Rgrc . The Flory-type critical exponent nu SAW of self-avoiding rings at D=2 is found to be nu SAW=0.5869(5) from the radii of gyration chain length scaling, while other D values produce consistent results. For our current implementation, the numerical effort of chain thickness calculations is bounded by a number O(LlnL) per single update. We also study low-temperature configurations of spatially dense Lennard-Jones homopolymers on a ring and identify some conformational building blocks.

Free-energy calculations with multiple Gaussian modified ensembles

We present a Monte Carlo algorithm, which samples free energies of complex systems. Less probable configurations are populated with the help of a multitude of additional Gaussian weights and parallel tempering is used for efficient Monte Carlo moves within phase space. The algorithm is easily parallelized and can be applied to a wide class of problems. We discuss algorithmic performance for the case of low-temperature phase separation in two-dimensional and three-dimensional Ising models, where we determine the magnetic interface tension. Multiple Gaussian modified ensemble simulations, unlike multicanonical ensemble simulations do not require a priori knowledge of the free energy and are of similar efficiency as multicanonical ensemble and Wang-Landau simulations.

Reliability of non-invasively acquired human genomic DNA as a substrate for real-time PCR-assisted analysis of genetic polymorphisms

Molecular epidemiological studies require high numbers of participants. The combination of an non-invasive access to human DNA with a rapid genotyping analysis, e.g. by use of LightCycler assisted real-time polymerase chain reaction (PCR), can be helpful in conducting such trials. The aim of our study was to define, for the first time, the use of LightCycler technology in analysis of non-invasively derived DNA. DNA extracted from blood, mouthwash and buccal cytobrush samples from 100 volunteers was analyzed for the genotypes of cytochrome P450 CYP1B1, and glutathione S-transferases GSTT1, GSTM1 and GSTP1. The median amounts of DNA isolated from blood, mouthwash and buccal cytobrush samples were 95, 11 and 8 microg, respectively. While genotyping for CYP1B1 codon 432 polymorphism and GSTP1 codon 105 polymorphism resulted in a complete correspondence for all three modes of sampling, the identification of individuals with null-genotype for GSTT1 or GSTM1 failed in some cases due to atypical courses of the corresponding melting curves, leading to high false-positive rates in the group of non-invasively derived samples. Thus, the results presented here call for caution in using LightCycler assisted real-time PCR in non-invasively collected samples, at least when appropriate control strategies are not implemented.

Fatal pulmonary scedosporiosis. Letal verlaufende pulmonale Scedosporiose

We report on a case of scedosporiosis in a 72-year-old German woman. Her disease started with a purulent ulceration of unknown course at her left foot. Soon after onset of oral antibacterial therapy she needed in-hospital treatment because of an acute pneumonia. The infection progressed despite the application of different antibiotics. Microscopic examination of tracheal fluid revealed fungal hyphae and therefore treatment with itraconazole was initiated. However, the patient developed renal failure, required mechanical ventilation and finally died in treatment-resistant septic shock. Post-mortem Scedosporium apiospermum was cultured from lung tissue taken during autopsy. This is the fourth case of human infection caused by Scedosporium species diagnosed in our laboratory during the last 4 years.

[Recurrent spontaneous hemorrhage in a patient with light chain immunocytoma]

The 48-year-old female patient was sent to our clinic for further evaluation of a spontaneous decrease of prothrombin- and prolongation of the bleeding-time. She presented in good conditions with an enlargement of cervical lymphnodes and the history of a monoclonal plasmacyte dyscrasia. The laboratory results revealed a pronounced decrease of prothrombin-time, a prolonged activated partial thromboplastin-time, a decrease of factor VII and X activity and a light chain paraprotein. The histological examination of the bone marrow led to the diagnosis of an immunocytoma and a medullar amyloidosis. For the aim of influencing the coagulopathy the patient was treated with chemotherapy. However, she developed severe bleedings. Further haemostaseological tests presented an amyloidosis-associated decrease of factor VII and X, an acquired von Willebrands disease, an acquired thrombozytopathy and a lupus-like anticoagulans. Under substitution of factor VIII-von Willebrand-factor-complex and chemotherapeutic treatment a stabilisation over several years was achieved till the patient died due to an amyloid-associated acute pancreatitis.

[Local and systemic symptoms after snake bite by a diamondback rattlesnake (Crotalus atrox)]

The incidence of snake bites grows more and more. The effects of the snake poison depend on the snake species. They can be cardio-, neuro-, myo-, tissue-, and/or cytotoxic, as well as hemorrhagically. In most cases a symptomatically therapy together with close controls of the labor parameters and a good monitoring is enough. Antivenom-therapy should be reserved for cases with strong indication.

Defining severe community-acquired pneumonia

Based on the recognition of the main pathophysiologic features of pneumonia and currently available data on prognosis and clinical severity assessment, key points for a definition of severe pneumonia are as follows: 1. Independent predictors of pneumonia severity are factors reflecting acute respiratory failure and severe sepsis or septic shock. 2. In view of the dependence of the development of acute respiratory failure on pulmonary comorbidities, radiographic extension may prove to be an additional independent predictor of severe respiratory compromise. 3. Vital sign abnormalities other than acute respiratory failure and severe hypotension may be independent predictors of severity, particularly in patients presenting in early and asymptomatic stages of severe sepsis. 4. Several pathogens have been shown to have adverse prognostic potential. Because the cause is unknown at the initial evaluation, however, pathogens cannot form part of the criteria for the initial severity assessment. 5. Because pneumonia is a dynamic process, any assessment of severity takes place at an arbitrary point of disease evolution. It would be desirable to define a set of parameters reflecting initial severity as well as a state of increased risk for early deterioration toward severe pneumonia. 6. Severity stratification within the population of patients with severe pneumonia may open the prospect of identifying patients who may have the greatest benefit from intensive care.

[An uncommon cause of severe soft tissue bleeding during phenprocoumon treatment]

HISTORY AND ADMISSION FINDINGS

A 66-year-old patient presented to our clinic with extensive left arm and left flank haematomas, anaemia, a prolonged activated partial thromboplastin time (aPTT), and reduced factor IX activity 6 weeks after prosthetic mechanical aortic valve implantation.

INVESTIGATION

Treatment with both vitamin K and a single injection of factor IX concentrate led to normalization of the activated partial thromboplastin time and factor IX activity, which remained constant for several days. No acquired factor IX inhibitor was detectable. Analysis of exon 2 of the factor IX gene revealed a C-->T mutation in codon 10 of the propeptide region, resulting in the substitution of alanine by valine. Echocardiography revealed a significant paravalvular leak.

TREATMENT AND COURSE

The substitution of valine for alanine in the factor IX propeptide leads to an impaired affinity of factor IX to the vitamin K-carboxylase complex. In this situation, treatment with coumarin derivatives can profoundly reduce factor IX activity and result in severe bleeding episodes. This patient was re-exposed to warfarin under close hematological monitoring. After 4 days factor IX activity had decreased to 15%, which was associated with an increase of the aPTT and a mild decrease of the prothrombin time. Due to rapid progression of the paravalvular leak and almost impossible long-term orale anticoagulation with coumarin derivatives, we recommended replacement of the prosthetic mechanical valve with a biological device.

CONCLUSION

The development of severe bleeding in the context of initiating warfarin therapy raises the suspicion of a factor IX propeptide mutation. The initial screening test is the activated partial thromboplastin time, which is elevated in the presence of the mutation. If concomitantly diminished factor IX activity is found the factor IX propeptide mutation should be excluded. Use of lifelong coumarin derivatives is contraindicated in patients with this mutation. However, a general screening of the activated partial thromboplastin time after coumarin initiation is not justified by cost/benefit analysis.

The effect of dexamethasone on respirator-dependent very-low-birth-weight infants is best predicted by chest X-ray

BACKGROUND

Chronic lung disease (CLD) in premature infants shows a variable clinical course with different radiological manifestations.

OBJECTIVE

To evaluate the correlation between parameters of trans-membrane permeability [albumin/secretory component (SC)] and oxidative stress [malondialdehyde (MDA)/SC] in tracheal aspirate fluid (TAF) and radiological findings with the effect of a 5-day course of dexamethasone (0.5 mg/kg per day).

MATERIALS AND METHODS

Fifty ventilator-dependent premature infants with birth weights < 1,500 g (gestational ages 23-31 weeks) and radiological signs of early chronic lung disease (CLD) were treated with dexamethasone at day of life 5-27 (median 10 days) because of respiratory deterioration. TAF was collected serially. Chest X-rays taken before and 8-10 days after dexamethasone were scored for changes of opacification, consolidation and hyperinflation/emphysema, and classified into three groups.

RESULTS

Twenty-four infants had a positive response to dexamethasone, defined as a reduction of the ventilation index FiO2 x mean airway pressure > 40% at day 5, compared to pretreatment values. About 80% of the responders showed homogeneous lung opacification on chest X-ray, reflecting leaky lung syndrome. In contrast, seven of eight infants with predominantly emphysema on radiology were non-responders; 80% of infants with a mixed radiological picture characterized by predominance of consolidations alternating with regions of emphysema were also non-responders. Ratios of albumin/SC and MDA/SC in TAF decreased significantly within 3 days after the onset of dexamethasone. However, MDA/SC was persistently higher in non-responders compared to responders. Opaque lungs were largely improved by dexamethasone, in contrast to streaky or patchy consolidations and emphysema. In a logistic regression model, radiographic classification was the most important factor influencing the response to dexamethasone with a positive predictive value of 86%, followed by albumin/SC ratio.

CONCLUSIONS

The optimum timing of dexamethasone treatment may be determined by the stage of developing CLD and radiological findings rather than by the age of the premature infant.

Rapid analysis of alpha1-antitrypsin PiZ genotype by a real-time PCR approach

alpha1-Antitrypsin (AAT) deficiency is a common inherited cause of emphysema and cirrhotic liver disease. Current laboratory diagnosis of Pi (proteinase inhibitor) status by protein analysis depends on the availability of blood samples and has a limited accuracy. Single-strand conformational polymorphism (SSCP) analysis and direct DNA sequencing can be performed from blood cells or from tissue samples, but it is a time-consuming procedure not suitable for screening purposes. We used a Light-Cycler assisted PCR approach to identify the PiZ mutation and to determine hetero- and homozygous carrier status from whole blood and from paraffin-embedded archival tissue specimens. The results were compared to those obtained by standard PCR amplification followed by SSCP and direct DNA sequencing. Light-Cycler assisted PCR identified heterozygous PiZ mutations in 16 samples, a homozygous PiZ status in three cases, and wild-type PiM in five control samples. In all cases the results were confirmed by SSCP and direct DNA sequencing. Light-Cycler assisted PCR has a high detection rate for the PiZ mutation. It can be performed from blood or from fixed archival tissues, requires only small amounts of DNA, and allows a rapid diagnosis on a high output level.

Tumour necrosis factor-alpha gene expression and production in human umbilical arterial endothelial cells

Endothelial cells act as an interface between the blood and tissues, and are known to be involved in inflammatory processes. These cells are responsive to and produce different cytokines. Tumour necrosis factor-alpha (TNF-alpha) not only is one of the most important inflammatory peptides, but also can be induced by lipopolysaccharide (LPS). The focus of the present study was on TNF-alpha gene expression and production in human umbilical arterial endothelial cells (HUAEC), including the kinetics of this process. Interleukin-1alpha (IL-1alpha), LPS and TNF-alpha, which are all known to be elevated in septic shock, were used as stimulators at concentrations commonly found in patients with sepsis. Through the use of reverse transcriptase/PCR, immunohistochemical reactions and ELISA techniques, we showed that, in HUAEC, all three stimuli were able to induce gene expression and production of TNF-alpha. Furthermore, this induction by IL-1alpha, LPS and TNF-alpha occurred in a time- and concentration-dependent manner in these cells. TNF-alpha expression and production was induced by all three agents at concentrations commonly found in patients with sepsis. TNF-alpha mRNA was observed within 30 min regardless of the stimulus used, but the levels peaked at different times. Since it is well established that TNF-alpha is able to induce the synthesis of IL-1alpha in endothelial cells and, as shown in the present study, TNF-alpha and IL-1alpha are themselves able to induce the synthesis of TNF-alpha in endothelial cells, an autocrine potentiation of cytokine release in sepsis can be proposed. This situation could lead to a locally acting 'vicious cycle' which, when considered in addition to the known ability of TNF-alpha to induce apoptosis, could mean that various organs will be damaged, a condition associated with sepsis. Thus these results provide further evidence for the important role played by the endothelium in inflammation.

Identification of syntenin and other TNF-inducible genes in human umbilical arterial endothelial cells by suppression subtractive hybridization

Endothelial cells play an important regulatory role in inflammatory responses by upregulating various proinflammatory gene products including cytokines and adhesion molecules. A highly potent mediator of this process is tumor necrosis factor-alpha (TNF). In the present study, the suppression subtractive hybridization (SSH) method was employed to identify rarely transcribed TNF-inducible genes in human umbilical arterial endothelial cells. Following mRNA isolation of non-stimulated and TNF-stimulated cells, cDNAs of both populations were prepared and subtracted by suppression PCR. Sequencing of the enriched cDNAs identified 12 genes differentially expressed including vascular cell adhesion molecule-1, monocyte chemoattractant protein-1, interleukin-8 and IkappaBalpha, an inhibitor of the transcription factor nuclear factor-kappaB. Interestingly, also syntenin, a PDZ motif-containing protein which binds to the cytoplasmic domain of syndecans, was identified by SSH. Time course studies using RT-PCR analysis confirmed that all genes were differentially expressed and rapidly induced by TNF. Our data reveal that SSH is a powerful technique of high sensitivity for the detection of differential gene expression in primary arterial endothelial cells.

Renal chloride channel, CLCN5, mutations in Dent's disease

Dent's disease is an X-linked renal tubular disorder characterized by low-molecular-weight proteinuria, hypercalciuria, nephrocalcinosis, nephrolithiasis, and renal failure. Patients with Dent's disease may also suffer from rickets and other features of the renal Fanconi Syndrome. Patients may have mutations in the X-linked renal chloride channel gene, CLCN5, which encodes a 746-amino-acid protein with 12-13 transmembrane domains. We have investigated the 11 coding exons of CLCN5 for mutations in eight unrelated patients with Dent's disease. Leukocyte DNA was used for the polymerase chain reaction amplification of CLCN5 and the products analyzed for single-stranded conformational polymorphisms (SSCPs). Abnormal SSCPs were sequenced and revealed eight mutations. These consisted of three nonsense mutations (Arg34Stop, Arg648Stop, Arg704Stop), four deletions involving codons 40, 86, 157, and 241, and one acceptor splice consensus sequence mutation tgcag --> tgaag. The mutations were confirmed either by restriction endonuclease or sequence-specific oligonucleotide hybridization analysis. In addition, an analysis of 110 alleles from 74 unrelated normal individuals demonstrated that the DNA sequence changes were not common polymorphisms. All of the mutations predict truncated chloride channels that are likely to result in a functional loss. Thus, our findings expand the spectrum of CLCN5 mutations associated with Dent's disease and the results will help to elucidate further the functional domains of this novel chloride channel.

[Cushing syndrome with occult ectopic ACTH production]

A 19-year old patient was admitted to our hospital with the typical stigmata of a prolonged Cushing's syndrome. He presented first at another hospital with elevated ACTH values and the diagnosis of pituitary Cushing's syndrome was made. A partial hypophysectomy was performed, but neither this nor a therapy with ketokonazole could influence the cortisol levels. Because of this background the diagnosis of ectopic ACTH-production was established. Since we were not able to locate a source of ACTH, we recommended a bilateral adrenalectomy, after which the symptoms of Cushing's syndrome disappeared within a few months. About one year after the operation a CT-scan demonstrated an intrapulmonary mass, which was removed surgically. There were neither signs of local infiltration nor of lymphogenic metastasis. The histological and immunhistochemical diagnosis was typical of bronchial carcinoid with ACTH-production. The follow up so far did not reveal a recurrence.

Effect of plasma from patients with idiopathic nephrotic syndrome on proteoglycan synthesis by human and rat glomerular cells

In vivo and in vitro findings have shown that plasma of patients with idiopathic nephrotic syndrome (INS) contain factors that increase glomerular permeability to proteins. The effects of these factors on proteoglycan synthesis by glomerular cells are unknown. To investigate the effect of plasma from patients with INS (n = 23) and other glomerulopathies (n = 12) on the amount of proteoglycans synthesized by cultured rat mesangial cells and human glomerular epithelial cells, glomerular cells were cultured for 24 h with plasma from patients or control subjects, and incorporation of Na2(35)SO4 in chondroitin dermatan sulfate and heparan sulfate was assessed using a cationic nylon membrane. The mean ratio of glycosaminoglycan produced by rat mesangial cells when in contact with plasma (5%) from INS patients to the amount produced when in contact with control plasma was 0.70+/-0.06. The mean ratio of heparan sulfate was 0.58+/-0.08. The decrease of heparan sulfate production was present in the cellular and in the extracellular fraction. It was observed when the cells were in contact with plasma from patients in relapse but not when in remission. No decrease of heparan sulfate production was observed with four of the five patients with membranous glomerulonephritis (ratio of 1.27+/-0.03), IgA nephropathy (n = 5, ratio of 1.27+/-0.03), and membranoproliferative glomerulonephritis (n = 2, ratio of 1.39+/-0.34). When human glomerular epithelial cells were exposed to 5% plasma from INS patients in relapse (n = 9), the mean ratio of heparan sulfate was 0.62+/-0.06 in the cellular fraction and 0.72+/-0.08 in the medium. When in contact with plasma from patients in remission, no difference of glycosaminoglycan production was observed. A factor present in plasma from patients with INS during initial episodes or relapses is able to decrease the proteoglycan production of glomerular cells.

Influence of nutrition on urinary oxalate and calcium in preterm and term infants

Few data for normal urinary oxalate (Ox) and calcium (Ca) excretion related both to gestational age and nutritional factors have been reported in preterm or term infants. We therefore determined the molar Ox and Ca to creatinine (Cr) ratios in spot urines from 64 preterm and 37 term infants aged 1-60 days, either fed formula or human milk (HM). Only vitamin D was supplemented; renal or metabolic diseases were excluded. Urinary Ox/Cr ratio was higher in preterm than in term infants, both when formula fed (1st month 253 vs. 180 mmol/mol and 2nd month 306 vs. 212 mmol/mol; P<0.05) or HM fed (206 vs. 169 mmol/ mol and 283* vs. 232 mmol/mol; *P<0.05). Ox/Cr was also higher in formula- than HM-fed preterm infants. The ratio increased during the first 2 months of life irrespective of nutrition. Urinary Ca/Cr ratio was comparable in all groups during the 1st month of life, except for a lower (P < 0.05) value in term infants fed HM (0.10 mol/mol). It increased in all groups during the 2nd month of life, being highest in HM-fed preterm infants (1.86 mol/mol). In conclusion, urinary Ox and Ca excretion is influenced by both gestational age and nutrient intake in preterm and term infants.

Possible role of uric acid as an antioxidant in premature infants

Uric acid (UA) is a water-soluble antioxidant in human body fluids. In umbilical cord blood of 172 neonates with gestational ages between 22 and 42 weeks, UA concentrations were between 50 and 990 mumol/l. There was no correlation with gestational age. Infants with an umbilical cord pH < 7.0 had markedly lower UA concentrations in cord blood than neonates without severe acidosis. UA levels increased during the first 24 h of life and subsequently declined within 2 weeks to lower levels than in older children. In tracheal aspirates (TA), UA at concentrations of about 10(-4) mol/l was found capable of effectively scavenging free oxygen radicals. Luminol-dependent chemiluminescence activity of isolated TA phagocytes or alveolar macrophages was suppressed by UA dose dependently, with a 100% reduction at UA concentrations of 10(-3) mol/l. On the assumption that oxidative stress contributes to the development of chronic lung disease (CLD), in premature infants the ratio of the antioxidant UA and malondialdehyde (MDA) as a marker of oxidative injury was measured in serially obtained TA of 102 ventilated premature infants with birth weights < 1,500 g. At the age of 3-14 days, infants who later developed severe CLD had significantly lower TA UA/MDA ratios than infants without CLD development. In infants with moderate CLD, UA/MDA ratios were comparable to those in the non-CLD group until day 5. During the next 2 weeks, decreasing ratios of UA/MDA paralleled lung injury with increased oxygen requirement and microvascular permeability. Serum UA concentrations did not differ between groups. It is speculated that UA may be physiologically important as an antioxidant in the epithelial lining fluid of the respiratory tract in neonates during the 1st week of life.

A vertical (pseudodominant) pattern of inheritance in the autosomal recessive disease primary hyperoxaluria type 1: lack of relationship between genotype, enzymic phenotype, and disease severity

Primary hyperoxaluria type 1 (PH1) is a rare autosomal recessive disease caused by a deficiency of alanine:glyoxylate aminotransferase (encoded by the AGXT gene). Primary hyperoxaluria type 1 is characterized by the elevated urinary excretion of oxalate and glycolate, and the deposition of insoluble calcium oxalate in the renal parenchyma and urinary tract. In the present study, we investigated an unusual family containing four affected individuals in two different generations. Based on our genetic, enzymic, metabolic, and clinical analyses, we have come to the following conclusions. First, although the pattern of inheritance of PH1 is usually horizontal (ie, all patients in the same generation), as expected for an autosomal recessive disease, it can sometimes show a vertical (pseudodominant) pattern of inheritance (ie, patients in more than one generation) due to the segregation within a family of three, rather than two, mutant AGXT alleles. Second, affected members of such a family can manifest very different clinical phenotypes both within and between generations. Although the clinical differences between generations might be at least partly due to differences in AGXT genotype, differences can equally occur within the same generation in individuals who possess the same AGXT genotype. Finally, individuals with PH1 at the level of the AGXT genotype might remain asymptomatic and undiagnosed for many years. The consequences of these findings for the clinical management and genetic counseling of families with PH1 are profound and wide-ranging.

Biotransformation of glyceryl trinitrate by blood platelets as compared to vascular smooth muscle cells

The present study investigated the metabolism of glyceryl trinitrate by washed human platelets as compared to that by rat vascular smooth muscle cells. Possible changes in metabolism after induction of nitrate tolerance were also studied in both systems. Incubation of the cells with glyceryl trinitrate (0.1 mM) resulted in a time-dependent release of nitrite (NO2-) amounting to 6.30 +/- 0.63 nmol mg protein-1 h-1 in vascular smooth muscle cells and 0.61 +/- 0.08 nmol mg protein-1 h-1 for platelets, respectively. The nitric oxide (NO) scavenger, oxyhemoglobin (10 microM), significantly reduced NO2- generation in both cell types studied. Nitrate tolerance was induced by incubation of the cells with glyceryl trinitrate (2 mM) for 2 h. In tolerant vascular smooth muscle cells as well as in tolerant platelets, NO2- release was significantly reduced. The inhibitory capacity of glyceryl trinitrate on ADP (6 microM)-induced platelet aggregation and on intracellular Ca2+ signals was significantly reduced in tolerant platelets. The data show a direct metabolism of glyceryl trinitrate by human blood platelets which is subject to a type of tolerance development similar to that in vascular smooth muscle cells.

Efficacy of oral citrate administration in primary hyperoxaluria

Urinary citrate is a potent inhibitor of calcium oxalate (CaOx) crystallization, but oral citrate has rarely been used in patients with primary hyperoxaluria (PH). We studied the effect of sodium citrate administration (0.1-0.15 g/kg/day) on urinary citrate excretion and CaOx saturation in seven paediatric patients and the clinical response to long-term treatment (average 4 years) in five patients. Urinary citrate increased from 0.73 to 2.54 mmol/24 h/1.73 m2 and urinary saturation for CaOx (calculated by equil 2) decreased from 11.41 to 6.79 (for both, p < 0.02). Long-term administration of alkali citrate [0.15 g (0.5 mmol)/kg/day] resulted in stable or improved renal function in three and slow deterioration in two partially non-compliant patients. Alkali citrate is effective in patients with PH.

[Therapy with growth hormone in pediatric patients with chronic kidney insufficiency]

Statural growth in children with chronic renal failure (CRF) is often delayed. Several studies have shown that one of the main causes is partial resistance to growth hormone (GH), which can be overcome by supraphysiologic doses of recombinant human (rh) GH. Since August 1990 we have been treating 8 boys and 1 girl (ages 1.7-12.7, mean 5.3 yrs) with rhGH (4 IU/m2 s.c. daily). All patients were prepubertal and were 2.4-4.5 (mean 3.2) SDS below the mean normal height for age and sex. 5 patients were on dialysis. Mean growth velocity was -2.0 SDS (5.4 cm/yr) before and +2.6 SDS (9.5 cm/yr) during the first year of therapy with rhGH. Mean height increased from -3.2 to -2.5 SDS at 1 year. Height in the 4 boys treated > 2 yrs with rhGH improved from -3.3 SDS (before rhGH) to -2.4 (1st yr) and to -2.0 SDS (2nd yr); their height increased by 9.6 cm (1st yr) and 7.8 cm (2nd yr) as compared to 4.6 cm in the year before treatment. The response to rhGH was better in the 4 patients treated conservatively than in those on dialysis. Side effects did not occur. Plasma insulin increased but the oral glucose tolerance test remained normal. We conclude that treatment with rhGH represents an important step forward in selected pediatric patients with CRF. The excellent acceptance reflects the high expectations of the patients and their families.