Perspectives on weak interactions in complex materials at different length scales

Nanocomposite materials consist of nanometer-sized quantum objects such as atoms, molecules, voids or nanoparticles embedded in a host material. These quantum objects can be exploited as a super-structure, which can be designed to create material properties targeted for specific applications. For electromagnetism, such targeted properties include field enhancements around the bandgap of a semiconductor used for solar cells, directional decay in topological insulators, high kinetic inductance in superconducting circuits, and many more. Despite very different application areas, all of these properties are united by the common aim of exploiting collective interaction effects between quantum objects. The literature on the topic spreads over very many different disciplines and scientific communities. In this review, we present a cross-disciplinary overview of different approaches for the creation, analysis and theoretical description of nanocomposites with applications related to electromagnetic properties.

Patent foramen ovale screening and prevention of decompression sickness in divers

Background/Introduction

Patent foramen ovale (PFO) is associated with increased risk of decompression sickness (DCS) due to paradoxical embolization of nitrogen bubbles that form during and after ascent. Screening for PFO using transcranial Doppler ultrasonography (TCD) is currently not recommended for all divers. If a diver is diagnosed with a high-grade PFO and wishes to continue diving there are currently two options to reduce the risk of DCS: catheter-based PFO closure or recommendation of conservative approach to diving. However, to date the evidence for the long-term effectiveness of these measures is limited.

Purpose

This study sought to compare the effectiveness of catheter-based PFO closure and conservative diving in the reduction of DCS incidence in divers with a high-grade PFO.

Methods

A total of 829 consecutive divers (35.4±10.0 yrs, 81.5% males) were screened for PFO between January 2006 and December 2018 by means of TCD. All patients were prospectively included in the study registry. Patients with a high-grade PFO were offered either catheter-based PFO closure (closure group) or advised to dive within the limits of recreational diving (conservative group). A trans-telephonic follow-up was performed at the end of the study. In this study we compared the incidence rate of DCS prior to enrollment and during the follow-up period in the closure and conservative group.

Results

Follow-up was available in 748 (90%) divers. Mean follow-up was 6.5±3.5 years. There were a total of 154 divers with a high-grade PFO that continued diving after the initial screening examination. Fifty-five (36%) of them underwent a catheter-based PFO closure (closure group), the remaining 98 divers were advised to dive within the limits of recreational diving (conservative group). The 55 divers in the closure group performed a total of 63,436 dives (30,684 prior to enrollment and 32,752 during the follow-up). Prior to enrollment there were 108 DCS episodes in 33 divers (incidence rate 3.3/1000 dives) and none during follow-up (p<0.001). The 98 divers in the conservative group performed a total of 48,069 dives (25,328 prior to enrollment and 22,741 during follow-up). There were 91 DCS episodes in 33 divers (incidence rate 3.6/1000 dives) prior to enrollment and 19 episodes in 11 divers (incidence rate 0.75/1000 dives) during follow-up (p<0.001). The incidence rate of DCS was similar for both groups prior to enrollment (p=0.196) but lower in the closure group during the post-interventional follow-up (p<0.001).

Conclusion(s)

In divers with a high-grade PFO both strategies decreased the incidence rate of DCS. Catheter-based PFO closure was more effective than conservative approach. The results also suggest that divers might benefit from screening for PFO.

Funding Acknowledgement

Type of funding source: None

CAMISIM: simulating metagenomes and microbial communities

BACKGROUND

Shotgun metagenome data sets of microbial communities are highly diverse, not only due to the natural variation of the underlying biological systems, but also due to differences in laboratory protocols, replicate numbers, and sequencing technologies. Accordingly, to effectively assess the performance of metagenomic analysis software, a wide range of benchmark data sets are required.

RESULTS

We describe the CAMISIM microbial community and metagenome simulator. The software can model different microbial abundance profiles, multi-sample time series, and differential abundance studies, includes real and simulated strain-level diversity, and generates second- and third-generation sequencing data from taxonomic profiles or de novo. Gold standards are created for sequence assembly, genome binning, taxonomic binning, and taxonomic profiling. CAMSIM generated the benchmark data sets of the first CAMI challenge. For two simulated multi-sample data sets of the human and mouse gut microbiomes, we observed high functional congruence to the real data. As further applications, we investigated the effect of varying evolutionary genome divergence, sequencing depth, and read error profiles on two popular metagenome assemblers, MEGAHIT, and metaSPAdes, on several thousand small data sets generated with CAMISIM.

CONCLUSIONS

CAMISIM can simulate a wide variety of microbial communities and metagenome data sets together with standards of truth for method evaluation. All data sets and the software are freely available at https://github.com/CAMI-challenge/CAMISIM.

Critical Assessment of Metagenome Interpretation-a benchmark of metagenomics software

Methods for assembly, taxonomic profiling and binning are key to interpreting metagenome data, but a lack of consensus about benchmarking complicates performance assessment. The Critical Assessment of Metagenome Interpretation (CAMI) challenge has engaged the global developer community to benchmark their programs on highly complex and realistic data sets, generated from ∼700 newly sequenced microorganisms and ∼600 novel viruses and plasmids and representing common experimental setups. Assembly and genome binning programs performed well for species represented by individual genomes but were substantially affected by the presence of related strains. Taxonomic profiling and binning programs were proficient at high taxonomic ranks, with a notable performance decrease below family level. Parameter settings markedly affected performance, underscoring their importance for program reproducibility. The CAMI results highlight current challenges but also provide a roadmap for software selection to answer specific research questions.

Critical Assessment of Metagenome Interpretation-a benchmark of metagenomics software

Methods for assembly, taxonomic profiling and binning are key to interpreting metagenome data, but a lack of consensus about benchmarking complicates performance assessment. The Critical Assessment of Metagenome Interpretation (CAMI) challenge has engaged the global developer community to benchmark their programs on highly complex and realistic data sets, generated from ∼700 newly sequenced microorganisms and ∼600 novel viruses and plasmids and representing common experimental setups. Assembly and genome binning programs performed well for species represented by individual genomes but were substantially affected by the presence of related strains. Taxonomic profiling and binning programs were proficient at high taxonomic ranks, with a notable performance decrease below family level. Parameter settings markedly affected performance, underscoring their importance for program reproducibility. The CAMI results highlight current challenges but also provide a roadmap for software selection to answer specific research questions.

[The current technical possibilities of the peroperative safety advancement in the microsurgery of cerebral aneurysms - a review article]

The authors present the technical aspects of perioperative safety during the microsurgery of cerebral aneurysms. We evaluated the advantages and disadvantages of the microvascular Doppler ultrasonography, the intraoperative digital subtraction angiography, the intraoperative transit time flowmetry, the intraoperative monitoring - motor evoked potentials and somatosensory evoked potentials, and the ICG videoangiography. The authors, based on their own experience, recommend combining different methods to eliminate the weak points of the individual specific methods. Combining the ICG with the flowmetry and the motor evoked potentials enhances safety during the surgery of cerebral aneurysms with the resultant reduction of the perioperative morbidity/mortality.

Effect of exercise on circulating levels of brain-derived neurotrophic factor (BDNF) in overweight and obese subjects

Exercise increases the expression of brain-derived neurotrophic factor (BDNF) in rodents and in healthy humans. Its relationship with weight loss and improvement in metabolic parameters, in obese human subjects, has not been elucidated. The aim of the study was to evaluate the effect of an aerobic exercise program on circulating levels of BDNF in overweight and obese subjects. We measured anthropometric and metabolic parameters in 15 male and female nondiabetic outpatients (age 38.3±9.5 years, BMI 27-35 kg/m2), before and after 30 sessions of aerobic exercise (3 sessions per week). Plasma (p), serum (s), and platelet (plat) BDNF concentrations were measured at basal condition and after completing 15 and 30 sessions of exercise. Subjects were advised to continue their usual food intake. A significant decrease in weight, BMI, waist circumference, diastolic blood pressure and total cholesterol was observed at the end of the study (p<0.02). Serum and platBDNF showed a significant increase during the training period (p=0.005 and 0.04 respectively). However, pBDNF showed no significant increase. Area under the curve of glucose at baseline, was inversely correlated with sBDNF (r= - 0.53, p=0.04) and platBDNF (r= - 0.6, p=0.01) after session 15. Also, platBDNF was correlated inversely with post load insulin and HOMA2-IR at the end of the training program (r= - 0.53, p=0.03 and r= - 0.52, p=0.04, respectively). In overweight and obese subjects, serum and platBDNF levels increase after 30 sessions of aerobic exercise. This is accompanied with the improvement of anthropometric and metabolic parameters and modest weight loss.

[Current microsurgical and neurointerventional therapy of cerebral aneurysms]

Cerebral aneurysms occur in 5% of the adult population. Their most severe clinical manifestation is subarachnoid haemorrhage occurring in half of the patients. Morbidity and mortality of subarachnoid hemorrhage is relatively high. Stopping blood flow into the aneurysmal sac is the treatment objective. The basic techniques to achieve this are closing the aneurysmal neck with a clip - clipping - and the induction of intraaneurysmal thrombosis using platinum coils - coiling. Fusiform and giant aneurysms represent a technical challenge. The solution for indicated cases is the occlusion of the magistral artery along with a high-flow bypass. A new option is the use of special stents - flow-diverters - in unruptured aneurysms. The authors present the current view on the treatment of both ruptured and unruptured aneurysms. At the same time the authors focus on factors that influence the application of up-to-date knowledge on everyday activities in their departments.

[Patent foramen ovale and the risk of paradoxical embolization of venous bubbles in divers - cave for foam sclerotization of varicose veins]

INTRODUCTION

Foam sclerotization of varicose veins may cause paradoxical embolization through patent foramen ovale (PFO). The aim of our study was to: 1) select an optimal screening method for the detection of PFO; 2) determine the prevalence of PFO in a non-selected population; and 3) test the risk of paradoxical embolization of venous bubbles in patients with PFO.

MATERIALS AND METHODS

A diver after decompression is a suitable model for determining the risk of paradoxical embolization of venous gas bubbles. 329 Czech divers were screened for PFO. In a pilot study, we compared Transcranial Doppler Sonography (TCD) with Transesophageal Echocardiography (TEE) in 100 patients. TCD alone was used for further screening. In 31 divers with PFO, nitrogen bubbles were detected after simulated dives. Transthoracic Echocardiography (TTE) was used to detect venous bubbles in right-sided heart chambers; TTE and TCD were used to detect arterial bubbles. The right-to-left shunt was rated as non-significant (<20 arterial bubbles) or significant (20 arterial bubbles). Different decompression regimens were compared.

RESULTS

In the pilot study, TCD was compared with the gold standard in PFO detection - TEE. The negative predictive value of TCD was 100%, positive predictive value was 92%. Screening was performed in a total of 329 divers, PFO was detected in 85 (25%), significant R-L shunt in 45 (14%). In simulated dive to 50 m maximum depth, venous nitrogen bubbles were detected in 7/8 (88%) divers. In 6/8 (75%) divers, paradoxical embolization was confirmed - nitrogen bubbles were detected in the systemic circulation.

CONCLUSION

PFO prevalence with significant R-L shunt was 14% in the non-selected population of Czech divers. Simulated dives indicate that PFO represents a risk factor for paradoxical embolization of gas bubbles. TCD is a suitable screening method for the detection of PFO and the evaluation of R-L shunt significance. These results are indicative of a possible high risk of paradoxical embolization of gas bubbles and the trombogenic substance in patients with a larger PFO and significant R-L shunt undergoing foam sclerotization of varicose veins.

Urinary miR-210 as a mediator of acute T-cell mediated rejection in renal allograft recipients

MicroRNAs (miRNAs) are small ribonucleotides regulating gene expression. Circulating miRNAs are remarkably stable in the blood. We tested whether miRNAs are also detectable in urine and may serve as new predictors of outcome in renal transplant patients with acute rejection. We profiled urinary miRNAs of stable transplant patients and transplant patients with acute rejection. The miR-10a, miR-10b and miR-210 were strongly deregulated in urine of the patients with acute rejection. We confirmed these data in urine of a validation cohort of 62 patients with acute rejection, 19 control transplant patients without rejection and 13 stable transplant patients with urinary tract infection by quantitative RT-PCR. The miR-10b and miR-210 were downregulated and miR-10a upregulated in patients with acute rejection compared to controls. Only miR-210 differed between patients with acute rejection when compared to stable transplant patients with urinary tract infection or transplant patients before/after rejection. Low miR-210 levels were associated with higher decline in GFR 1 year after transplantation. Selected miRNAs are strongly altered in urine of the patients with acute renal allograft rejection. The miR-210 levels identify patients with acute rejection and predict long-term kidney function. Urinary miR-210 may thus serve as a novel biomarker of acute kidney rejection.

Endarterectomy for asymptomatic carotid artery stenosis under local anaesthesia

BACKGROUND

In this article, we present our experience with such operations performed under local anaesthesia.

METHODS

From January 1997 to November 2007, there were 387 patients operated on for asymptomatic carotid stenosis. Patient data were retrospectively evaluated. Thirty-day neurological morbidity and mortality from six different subgroups were analysed and compared. The numbers of perioperative transient ischaemic attacks, as well as surgical and other perioperative complications were also evaluated.

RESULTS

Overall morbidity and mortality was 1.8% (seven patients). Stroke was noted in 1.3% (five patients). Transitory ischaemic attacks within the first 30 days were observed in 1.6% (six patients). Only those patients who had intraluminal shunt insertion were found to have significantly higher morbidity and mortality. (p = 0.000018). Myocardial infarction was observed in 0.5% (two patients), one fatal.

CONCLUSION

We have achieved acceptable morbidity and mortality rates (1.8%) according to the parameters set by previous studies such as Asymptomatic Carotid Atherosclerosis Study and Asymptomatic Carotid Stenosis Trial as well as American Heart Association and European Stroke Organisation guidelines. All surgeries were done under local anaesthesia. Shunts were inserted in 22 cases (5.68%).

[Simultaneous carotid endarterectomy and coronary revascularization: indications and results]

AIM

Evaluation of operative results and complications in high-risk patients who underwent combined carotid and coronary revascularization.

PATIENTS AND METHODS

Combined operation--carotid endarterectomy (CEA) and coronary artery bypass graft (CABG) was performed in the period 2000-2009 in 68 patients. Simultaneous operation was indicated in patients with unstable angina pectoris and 1. symtomatic internal carotid artery (ICA) stenosis > or = 50%, or 2. bilateral asymptomatic ICA stenosis > or = 60% or 3. asymptomatic ICA stenosis > or = 60% combined with contralateral ICA occlusion. Combined operations represented 5.8% of whole CEA series. Mean age was 69.9 (51-82) years, men were 46, women 22. Carotid angiography proved unilateral (always symptomatic) ICA stenosis in 25 patients, bilateral ICA stenosis in 35 patients and ICA stenosis combined with contralateral carotid occlusion in 8 patients. Neurological preoperative symptomatology: TIA was present in u 20 patients, minor stroke in 6 and major stroke in 5 patients. 37 patients were asymptomatic. One CABG was performed in 5 patients, 2 CABG in 20 patients, 3 CABG in 19 patients and 4 CABG in 6 patients. The rest of 18 patients had CABG operation combined with valve procedure. Comorbidity: hypertension 100%, diabetes mellitus 57.3%, hyperlipidemia 60.3%. Shunt was selectively used in 4.4%. The need for shunt was established using back stump pressure and near infrared spectroscopy.

RESULTS

Mortality was 8.8% (6/68). The cause of death were multiorgan failure in two cases, ipsilateral stroke in two patients, respiratory insufficiency and cardiac failure due to graft occlusion both in one patient. Good recovery was recorded in 91.2%.

CONCLUSION

Combined carotid and coronary revascularization has acceptable neurological morbidity/mortality in high risk patients. Strict requirement is thorough selection of patients.

MicroRNA-based therapeutic approaches in the cardiovascular system

MicroRNAs (miRNAs) are endogenous small ribonucleotides that participate in the orchestration of the genome by regulating target messenger RNA translation. MiRNAs control physiological processes and misexpression of miRNAs is pathogenically involved in many diseases including cardiovascular diseases. Normalization of miRNA expression and thus downstream target networks may have enormous therapeutic chances but also risks. We here highlight and discuss recent advances in the development and use of miRNA therapeutics to target miRNAs in vivo that may translate into novel therapeutic strategies for cardiovascular diseases in the future.

The (-765 G→C) promoter variant of the COX-2/PTGS2 gene is associated with a lower risk for end-stage hip and knee osteoarthritis

BACKGROUND

Functional polymorphisms in genes of proinflammatory signalling cascades may contribute to the genetic risk of osteoarthritis (OA).

OBJECTIVE

To examine a possible association between end-stage OA of the hip and knee joint and a known single nucleotide polymorphism (SNP) of the COX-2 gene promoter.

METHODS

The SNP -765 G→C (rs20417) of the COX-2 gene promoter was genotyped by pyrosequencing in 531 (320 women/211 men) patients with OA from the Ulm Osteoarthritis Study and 400 (200 women/200 men) regional controls from the south-west of Germany.

RESULTS

In the whole study population the C allele was associated with a lower risk (per allele OR 0.57; 95% CI 0.43 to 0.75, p&lt;0.0001) and the G allele with a higher risk for end-stage OA. Analysis of subgroups confirmed this result for primary, bilateral, hip and knee OA.

CONCLUSION

The promoter polymorphism rs20417 of the COX-2 gene contributes to the genetic risk for end-stage hip and knee OA.

[Spinal cord stab injury associated with modified Brown-Séquard syndrome symptoms--a case review and literature overview]

Authors present case-report of young man with incomplete spinal cord injury after penetrating stab wound. Knife blade entered the skin in the level C3/4 in the back of the neck and directed to the right and downward. Both dorsal spinal cord columns and right half of spinal cord were transected. Neurological presentation was Brown-Séquard syndrome combined with dorsal columns syndrome. Wound revision was performed followed by dural closure. 18 month after injury significant neurological improvement of right hemiparesis was recorded and the patient is self-sufficient. Spinal cord stab wounds are rare. Typical clinical symptomatology is incomplete spinal cord injury. Clinical improvement of Brown-Séquard syndrome in our patient entirely corelates with literature.

Altered migration and adhesion potential of pro-neurally converted human bone marrow stromal cells

BACKGROUND

Bone marrow (BM)-derived mesenchymal stromal cells (MSC) are promising candidate cells for the development of neuroregenerative therapies. We have previously introduced the pro-neural conversion of human MSC to neural stem cell-like cells (m-NSC) by culturing them in suspension culture under serum-free conditions.

METHODS

In the present study, we used a modified Boyden chamber assay to study the influence of various chemoattractants and extracellular matrix components on MSC and m-NSC migration in vitro. The underlying mechanisms were investigated further by applying real-time reverse transcriptase (RT)-polymerase chain reaction (PCR) and flow cytometry.

RESULTS

The basal migration of m-NSC was significantly reduced compared with MSC (six versus 27 out of 10,000 cells migrated within 6 h). We evaluated the effects of bone morphogenic protein 2 (BMP2), insulin-like growth factor 1 (IGF1), platelet-derived growth factor bb (PDGFbb), vascular endothelial growth factor (VEGFa), and stromal cell-derived factor 1 (SDF1) on the migration potential of both cell types and PDGFbb proved to be the most potent stimulant of migration (235 versus 198 m-NSC or MSC migrated). Adhesion of m-NSC to the filter membrane was delayed and not affected by IGF1 or PDGFbb: 90% of MSC, but only 20% of m-NSC, adhered within 1 h, with 90% of m-NSC adhering within 3 h. However, real-time RT-PCR and flow cytometry revealed an up-regulation of the PDGF receptor B following conversion. Coating the membranes with collagen type I or hyaluronan also significantly influenced cell migration.

DISCUSSION

We could identify major chemoattractive factors for m-NSC and gained partial insight into the complex processes involved in migration of neurally converted cells.

Perinatal asphyxia induces neurogenesis in hippocampus: an organotypic culture study

There is clinical and experimental evidence indicating that neurocircuitries of the hippocampus are vulnerable to hypoxia/ischemia occurring at birth, inducing, upon re-oxygenation/re-circulation, delayed neuronal death, but also compensatory mechanisms, including neurogenesis. In the present report, perinatal asphyxia was induced by immersing foetuses-containing uterine horns removed from ready-to-deliver rats into a water bath at 37 degrees C for 20 min. Some pups were delivered immediately after the hysterectomy to be used as non-asphyxiated caesarean-delivered controls. The pups were sacrificed after seven days for preparing organotypic hippocampal cultures. The cultures were grown on a coverslip in a medium-containing culture tube inserted in a hole of a roller device standing on the internal area of a cell incubator at 35 degrees C, 10% CO2. At days in vitro (DIV) 25-27, cultures were fixed for assaying cell proliferation and neuronal phenotype with antibodies against 5-bromo-2'deoxyuridine (BrdU) and microtubule associated protein-2 (MAP-2), respectively. Confocal microscopy revealed that there was a 2-fold increase of BrdU-positive, but a 40% decrease of MAP-2-positive cells/mm3 in cultures from asphyxia-exposed, compared to that from control animals. Approximately 30% of BrdU-positive cells were also positive for MAP-2 (approximately 4800 cells), mainly seen in the dentate gyrus of the hippocampus, demonstrating a 3-fold increase of postnatal neurogenesis, when the total amount of double-labelled cells seen in cultures from asphyxia-exposed animals is compared to that from control animals.

Pregnancy-associated plasma protein A and proform eosinophilic major basic protein in the detection of different types of coronary artery disease

Kryptor system was proven to be a rapid, standard method for pregnancy-associated plasma protein A and proform eosinophilic major basic protein (PAPP-A/proMBP) complex detection in coronary artery disease (CAD). No age and/or gender differences in 51 controls and 110 stable coronary artery disease (SCAD) patients were found. SCAD patients did not differ from controls and no difference in PAPP-A/proMBP levels with regards to the number of affected vessels was found. In 21 unstable angina pectoris (UAP), in 35 without and 66 with ST elevation acute myocardial infarctions (NSTEMI, STEMI respectively) patients PAPP-A/proMBP levels were increased (P=0.004 and P<0.0005, respectively). PAPP-A/proMBP levels did not correlate with cardiac troponin I (cTnI) in STEMI and NSTEMI patients. PAPP-A/ proMBP increase was more frequent than cTnI (P=0.036) within the early phase of STEMI. In NSTEMI patients PAPP-A/proMBP positivity was present in 50% of cTnI negative cases. Receiver operating characteristic (ROC) analysis revealed the highest diagnostic accuracy of PAPP-A/proMBP (0.919) in STEMI cTnI positive cases. The highest specificity/sensitivity PAPP-A/proMBP levels for particular acute coronary syndrome (ACS) types were 10.65-14.75 mIU/l. Combination of PAPP-A/proMBP with cTnI increases their diagnostic efficacy within the early phase of ACS. Our results suggest that PAPP-A/proMBP complex is involved in processes preceding vulnerable plaque development in ACS.

[Ocular symptoms as an indication for carotid endarterectomy]

Ocular symptoms can be the first sign of carotid artery stenosis. In our carotid endarterectomy patients group were ocular symptoms present in 15%, as the only sign (without accompanying neurological signs) in 10.5%. Amaurosis fugax was a dominant sign in 56 cases, blindness in 5, quadrantanopia in 3; trochlear and oculomotor nerve paresis in one case. Angiography finding of more than 60% ICA stenosis according NASCET criteria was an indication for surgery. The operative technique per se was a microsurgical endarterectomy with selective peroperative shunt application. The 30-d morbidity was 3%--with one case of central retinal artery embolization and subsequent blindness and another case of major residual neurological deficit due to hyperperfusion syndrome and the resultant capsular hemorrhage. Shunt was applied in 3% of cases and microscope was used always since the beginning of the dissection up to the final suture. Considering low perioperative morbidity/mortality rates the carotid endarterectomy represents an important means of brain ischaemia profylaxis. In the process of hemodynamically significant ICA stenosis, indication for surgical management the authors emphasize the role of ocular signs and symptoms and thus the importance of an ophthalmology consultant.

Cold stress induces metabolic activation of thyrotrophin-releasing hormone-synthesising neurones in the magnocellular division of the hypothalamic paraventricular nucleus and concomitantly changes ovarian sympathetic activity parameters

Recent studies suggest thyrotrophin-releasing hormone (TRH) serves as a neurotransmitter and thereby provides a functional vegetative connection between the brain and the ovary. In the present study, magnocellular neurones of the paraventricular nucleus (PVN) in animals subjected to cold exposure were studied to determine the hypothalamic origin of the TRH involved in this pathway. In situ hybridisation analysis of hypothalamic tissue showed that cold exposure causes a two-fold increase in the total number of neurones expressing TRH mRNA in the PVN. Immunohistochemical studies showed that TRH peptide is localised to the magnocellular PVN and that the number of TRH immunoreactive cells increases two-fold following 64 h of cold exposure. Double-immunostaining for MAP-2 and TRH revealed that TRH peptide is localised in the perikarya of the magnocellular neurones. TRH release was measured in vivo from the magnocellular portion of the PVN using push-pull perfusion. Although controls exhibited a very low level of TRH release, animals subjected to cold showed a pulsatile-like TRH release profile with two different patterns of release: (i) low basal level with small bursts of TRH release and (ii) a profile with an up to seven-fold increase in TRH release compared to controls. The colocalisation of TRH with the specific somato-dendritic marker MAP-2 in processes of the magnocellular neurones suggested a local release of TRH. Additional studies demonstrated a reduction in ovarian noradrenaline content after 48 h of cold exposure, a feature indicative of nerve activation at the terminal organ. After 64 h of cold exposure, the ovarian noradrenaline returned to control values but the noradrenaline content of the coeliac ganglia was increased, suggesting a compensatory effect originating in the cell bodies of the sympathetic neurones that innervate the ovary. The correlation between the local release of TRH from dendrites within the magnocellular PVN in conditions of cold and the activation of the sympathetic nerves supplying the ovary raises the possibility that TRH contributes to the processing regulating sympathetic outflow and may thereby impact on the functional activity of the ovary.

Effects of perinatal asphyxia on cell proliferation and neuronal phenotype evaluated with organotypic hippocampal cultures

The present report summarizes studies combining an in vivo and in vitro approach, where asphyxia is induced in vivo at delivery time of Wistar rats, and the long term effects on hippocampus neurocircuitry are investigated in vitro with organotypic cultures plated at postnatal day seven. The cultures preserved hippocampus layering and regional subdivisions shown in vivo, and only few dying cells were observed when assayed with a viability test at day in vitro 27. When properly fixed, cultures from asphyxia-exposed animals showed a decreased amount of microtubule-associated protein-2 immunocytochemically positive cells (approximately 30%), as compared with that from controls. The decrease in microtubule-associated protein-2 immunocytochemistry was particularly prominent in Ammon's horn 1 and dentate gyrus regions (approximately 40%). 5-Bromo-2'deoxyuridine labeling revealed a two-fold increase in cellular proliferation in cultures from asphyxia-exposed, compared with that from control animals. Furthermore, confocal microscopy and quantification using the optical disector technique demonstrated that in cultures from asphyxia-exposed animals approximately 30% of 5-bromo-2'deoxyuridine-positive cells were also positive to microtubule-associated protein-2, a marker for neuronal phenotype. That proportion was approximately 20% in cultures from control animals. Glial fibrillary acidic protein-immunocytochemistry and Fast Red nuclear staining revealed that the core of the hippocampus culture was surrounded by a well-developed network of glial fibrillary acidic protein-positive cells and glial fibrillary acidic protein-processes providing an apparent protective shield around the hippocampus. That shield was less developed in cultures from asphyxia-exposed animals. The increased mitotic activity observed in this study suggests a compensatory mechanism for the long-term impairment induced by perinatal asphyxia, although it is not clear yet if that mechanism leads to neurogenesis, astrogliogenesis, or to further apoptosis.

[Comments on eversion technique of carotid endarterectomy]

The authors describe their own modification of carotid endarterectomy by eversion technique which they use in the case of combined stenosis and kinking of internal carotid artery. Complete division of internal carotid artery from the common carotid artery at the bulb is performed in an oblique fashion, following by excision of redundant wall. Added longitudinal incision of common carotid artery enables perfect removal of the atherosclerotic plaque. Proper posterior wall anastomosis of common and internal carotid artery in the bulb is carried out by one-way-up technique. This is an alternative to parachute technique and gives perfect view of operating field, thus decreasing the risk of technical mistake. Eversion technique of carotid endarterectomy represents an ideal operative technique in the case of carotid stenosis combined with kinking.

Mediating specific cell adhesion to low-adhesive diblock copolymers by instant modification with cyclic RGD peptides

One promising strategy to control the interactions between biomaterial surfaces and attaching cells involves the covalent grafting of adhesion peptides to polymers on which protein adsorption, which mediates unspecific cell adhesion, is essentially suppressed. This study demonstrates a surface modification concept for the covalent anchoring of RGD peptides to reactive diblock copolymers based on monoamine poly(ethylene glycol)-block-poly(D,L-lactic acid) (H(2)N-PEG-PLA). Films of both the amine-reactive (ST-NH-PEG(2)PLA(20)) and the thiol-reactive derivative (MP-NH-PEG(2)PLA(40)) were modified with cyclic alphavbeta3/alphavbeta5 integrin subtype specific RGD peptides simply by incubation of the films with buffered solutions of the peptides. Human osteoblasts known to express these integrins were used to determine cell-polymer interactions. The adhesion experiments revealed significantly increased cell numbers and cell spreading on the RGD-modified surfaces mediated by RGD-integrin-interactions.

Cognitive performance in people with Parkinson's disease and mild or moderate depression: effects of dopamine agonists in an add-on to L-dopa therapy

In a randomized prospective multi-centre study, we evaluated the cognitive performances of a group of 41 non-demented patients, all with advanced Parkinson's disease (PD) and a current depressive episode, in whom the effects of pramipexole (PPX) and pergolide (PRG) in an add-on to l-dopa therapy were also studied and published with regard to motor symptoms of PD, motor complications and depression. The Trail Making Test, the Stroop test and four subtests (arithmetic, picture completion, digit symbols and similarities) of the Wechsler Adult Intelligence Scale-Revised were performed prior to and 8 months after the administration of either PPX or PRG. We found no statistically significant difference between the two tested drugs or between the first and the last visit in any of the above-listed neuropsychological tests. All patients' motor outcomes significantly improved and we conclusively demonstrated the anti-depressive effect of PPX. The dissociation of dopaminomimetic effects on the different tested domains indicates that there are different pathological mechanisms of cognitive, motor and affective disturbances in advanced PD patients. In our non-demented group of fluctuating depressed PD subjects, both PPX and PRG administration in combination with l-dopa were safe in terms of the effect on cognitive performance.

[Deferral of coronary intervention based on measurement of myocardial fractional flow reserve]

BACKGROUND

Myocardial fractional flow reserve (FFR) is a useful method in assessment of functional significance of coronary stenosis. Deferral of intervention of angiographically intermediate lesion based on FFR measurement is safe in selected patient population as previously described. The aim of the study was to assess mid-term results after deferring coronary intervention of intermediate lesion in a non-selected patient population with no respect to the extent of coronary artery disease and to the results of stress tests if performed.

METHODS

A coronary intervention of angiographically intermediate lesion (40 - 70% according to QCA) was deferred in a group of 50 consecutive patients (33 men, mean age 60.8 +/- 10.2 y.) on the basis of FFR > or = 0.75 (mean FFR 0.89 +/- 0.06). FFR was measured in 62 lesions (mean stenosis diameter 55 +/- 7%, left anterior descending 34 lesions, circumflex artery 13 lesions, right coronary artery 15 lesions). One-vessel disease was presented in 14 pts (28%), 36 pts (72%) presented with multivessel disease (two-vessel disease in 27 pts - 54% and three-vessel disease in 9 pts - 18%). Stress test was positive in 15 pts, in 1 pts. negative, and in 3 pts. non-diagnostic. All-cause mortality, cardiac mortality, non-fatal myocardial infarction (MI) and ischemia driven target vessel revascularization (TLR) were recorded during follow-up. Severity of angina pectoris (CCS classification) and a need for antianginal treatment (beta-blockers, nitrates, calcium channel blockers) at the baseline and at the end of clinical follow-up was recorded.

RESULTS

Follow-up was completed in 49 patients (98%). Mean time of follow-up is 15.4 +/- 2 months (range 12 - 22 months, median 15 months), two patients died (4 %)--one from colon cancer, the other patient died from lung cancer, there was not any cardiac death recorded, two patients (4%) had target vessel revascularization. Estimated 22 months event-free (all-cause death, MI, TLR) survival was (mean +/- SEM) 86 +/- 7%. There was a significant difference in symptom severity--mean grade of angina pectoris at baseline was 1.8 +/- 1.3, at follow-up 1.1 +/- 1.0 (p < 0.05). There was not difference in use of antianginal drugs was same at baseline and at follow-up (1.7 +/- 0.8 vs. 1.7 +/- 0.7). Thirty-five patients (71%) were treated by statins.

CONCLUSIONS

Deferring of coronary interventions of intermediate stenosis based on FFR measurement is safe in a mid-term follow-up. Despite of the same intensity of antianginal treatment there was a significant decrease in symptom severity.

Identification, quantification and isolation of mesenchymal progenitor cells from osteoarthritic synovium by fluorescence automated cell sorting

OBJECTIVE

Identification, quantification and isolation of subpopulations with characteristics of mesenchymal progenitor cells (MPC) from the synovial membrane (SM) from patients with osteoarthritis (OA).

METHOD

Cells from the SM of patients with end stage OA who underwent total knee joint replacement were enzymatically isolated. One aliquot was directly analyzed by fluorescence automated cell sorting (FACS) using various combinations of surface markers of bone marrow MPC (CD9, CD44, CD54, CD90, and CD166). Remaining cells were cultivated on plastic, expanded over several passages, analyzed by FACS again and tested for their osteo- and chondrogenic potential. The differentiation was analyzed by immuno-/histochemistry and by RT-PCR for the expression of lineage related marker genes.

RESULTS

Using FACS analysis we could show that the relative proportion of subpopulations expressing triplicate combinations of CD9, CD44, CD54, CD90 and CD166 in the SM from OA patients varies between 3 and 10%. Upon cultivation their relative amount markedly increased to values between 24 and 48%. Within the heterogeneous cell populations it was possible to induce osteogenic and chondrogenic differentiation. Initial sorting for CD9/CD90/CD166 triplicate positive cells proved that this subpopulation contains cells with multipotency for mesenchymal differentiation and thus characteristics of MPC.

CONCLUSION

Our results show that SM from OA patients contains cells that express typical combinations of MPC surface markers and have the potency of osteogenic and chondrogenic differentiation. Their relative enrichment during in vitro cultivation and the possibility of cell sorting to get more homogenous populations offer interesting perspectives for possible future therapeutic applications.

Perinatal asphyxia impairs connectivity and dopamine neurite branching in organotypic triple culture from rat substantia nigra, neostriatum and neocortex

The effect of perinatal asphyxia on brain development was studied with organotypic cultures from substantia nigra, neostriatum and neocortex. Asphyxia was induced by immersing foetuses-containing uterine horns removed from ready-to-deliver rats into a water bath for 20 min. Following asphyxia, the pups were nursed by a surrogate dam and sacrificed after 3 days to prepare organotypic cultures. Non-asphyxiated caesarean-delivered pups were used as controls. Morphological features were recorded during in vitro development. At day in vitro (DIV) 24, the cultures were treated for histochemistry using fast red for cell nucleus labelling and antibodies against tyrosine hydroxylase for dopaminergic neurons. Compared to controls, cultures from asphyxiated pups revealed a diminished integration quantified during 21 DIV. After immunocytochemistry and camera lucida reconstruction, tyrosine hydroxylase-positive neurons showed a decreased number of neurites from secondary and higher level branching, demonstrating a vulnerability of the dopaminergic systems after perinatal asphyxia.

Pramipexole and pergolide in the treatment of depression in Parkinson's disease: a national multicentre prospective randomized study

An 8-month multicentre prospective randomized study aimed at comparing the effects of dopamine receptor agonists pramipexole (PPX; Mirapexin) and pergolide (PRG; Permax) as add-on to L-dopa therapy on depression [Montgomery and Asberg Depression Rating Scale (MADRS)] in 41 non-demented patients (25 men, 16 women) suffering from both mild or moderate depression and advanced Parkinson's disease (PD). The assessment was performed by a blinded independent observer. Motor symptoms (UPDRS III), motor complications (UPDRS IV), activities of daily living (UPDRS II and VI) and depressive symptoms as measured by Self - Rating Depression Scale by Zung were evaluated in an open-label design. The average value of Zung scores decreased significantly in both groups with no statistical difference between both groups. A significant decrease in the average value of MADRS scores was present only in the PPX group. The average UPDRS scores decreased significantly with no statistical difference between both groups at the comparable average total daily dose of both preparations. In both cases, the total daily dose of L-dopa decreased significantly but the decrease was statistically more pronounced in the PRG group. Our results demonstrate the antidepressant effect of PPX in patients with PD while we can't make any conclusions with regard to antidepressant effect of PRG.

Clinical phenotype and molecular diagnosis of multiple epiphyseal dysplasia with relative hip sparing during childhood (EDM2)

We report on a family of 19 individuals over four generations in which 12 members are affected with a variant of multiple epiphyseal dysplasia. Beginning in childhood, the disease leads to pain and stiffness of knees, ankles, elbows and finger joints. Some adult patients repeatedly suffer from free articular bodies resulting in locking of the joint. Finally, affected individuals are prone to the development of early degenerative joint disease. Mutation screening of candidate regions revealed a novel point mutation at position -1 in the COL9A2 exon 3/intron 3 splicing region. This G --> C substitution most probably induces an alteration of the splicing process. Family screening was carried out by both automated sequencing and by digestion of amplicons with BsaWI. We confirmed the nucleotide substitution in eight clinically affected family members as well as in three presymptomatic young children. Electron microscopy showed that the diameter of collagen fibrils from arthroscopically removed free articular bodies of two patients was not obviously different from that of normal articular cartilage. Together with previous reports our results indicate that mutations leading to skipping of exon 3 within the COL3 domain of the alpha2-chain of collagen type IX may be relatively common in patients with a special subtype of multiple epiphyseal dysplasia (MED) in which the hips are not markedly affected at early age (EDM2). In these patients and their families, mutation screening of the candidate regions may help to confirm the diagnosis, lead to appropriate advice for lifestyle and well based genetic counseling.

[Angiographically marginally significant coronary stenoses--postponement of intervention based on measurement of myocardial fractional flow reserve]

INTRODUCTION

When evaluating angiographically marginal coronary stenoses (i.e. 40-70% reduction of the diameter of the arterial lumen) it is under certain conditions difficult to decide on their actual functional impact. Assessment of the fractional flow reserve (FFR) is a simple method based on assessment of intracoronary pressures during pharmacologically induced hyperaemia. For the severity of stenosis according to previous studies the liminal values is FFR lower than 0.75; furthermore it was proved that intervention of angiographically marginal stenoses with FFR values of 0.75 or more can be safely postponed.

OBJECTIVE

Test the safety of FFR examination and take in a group of patients with marginally severe stenosis further steps according to results of FFR assessment.

MATERIAL AND METHODS

During the period from January to Juky 2000 FFR assessments were made in a total of 34 patients (11 women, 23 men, mean age 62 +/- 12 years) who suffered from marginal stenosis of some coronary vessel. The FFR examination took place under pharmacologically induced hyperaemia after intracoronary adenosine administration.

RESULTS

Measurements were made in a total of 41 stenoses. Only in two a value lower than 0.75 was found. In these patients coronary intervention was implemented; intervention was also made in two patients on account of technical problems and inconsistent results of FFR measurements. A FFR value of 0.75 or less was found in 37 stenoses (90%) and intervention was therefore postponed. Examination and the immediate subsequent course were without complications.

CONCLUSION

According to initial experience FFR examination is a safe, simple and easily reproducible method. Based on the results of assessment and knowledge of the accomplished studies in the group of marginally significant stenoses in a great proportion of patients coronary intervention was postponed.

Lipofection of rabbit chondrocytes and long lasting expression of a lacZ reporter system in alginate beads

OBJECTIVE

Our aim was to investigate the maintenance of the transfection status of non-viral transfected chondrocytes in an alginate culture system.

DESIGN

Chondrocytes harvested from rabbit knees were isolated by sequential digestion and cultivated in monolayer culture. At 60-70% cell density, chondrocytes were transfected with different transfection systems (FuGENE6, CaCl2, Lipofectin). A lac Z expression vector (pcDNA 3.1/Myc-His+ lacZ) was used as a reporter system. In order to improve transfection rates, hyaluronidase (4 U/ml) was used prior and during the transfection procedure. Thereafter, transfected cells were either kept in monolayer culture or embedded in alginate beads and kept in culture for up to the next 30 weeks.

RESULTS

Transfection efficiency was maximal using FuGENE6TM/DNA at a ratio of 3:2 and hyaluronidase (4 U/ml). Transfection efficiency reached up to 40.8% (+/- 3.2%) after 36 h. In alginate beads lac Z positive cells declined to 8.5% +/- 3.3% after 4 weeks and to 4.6% +/- 3.2% after 12 weeks of culturing. After 30 weeks 3% of chondrocytes still expressed lac Z. In contrast, during culturing in monolayer, no lac Z expression was detectable after 4 weeks. Differentiation status of the chondrocytes was confirmed by histology and immunohistochemistry methods.

CONCLUSIONS

After successful gene transfer to rabbit chondrocytes the alginate system made it possible to culture lipofected chondrocytes phenotypically stable. Genetically engineered chondrocytes express the lac Z reporter gene over a period of at least 30 weeks. This transfection and culture system provides a promising tool to further investigate the over-expression of growth factors and enzyme inhibitors.

[FMD and international trade relations--conditions and consequences]

The outbreak of foot-and-mouth disease in several member states of the European Union this year made the risks linked to this epidemic pretty clear to the public. In this connection, the possibility of vaccinations was controversially discussed not only among experts. Therefore it has to be taken into consideration that every kind of vaccination leads to economic consequences, which have to be taken into account when making such a decision. It is an illusion assuming that there will be a return to prophylactic vaccination. However in certain situations such emergency vaccination have to be available as an additional measure of control. Because of present decisions of the European Commission any consequences connected therewith are known. Thereby the EU regulations coincide with those of the Office International des Epizooties (OIE) and make the extent of restrictions after vaccination calculable. The assessment leads to the conclusion that preventive measures, rapid and successful eradication of FMD outbreaks as well as the option of emergency vaccination have to be followed as an overall conception.