[Functional impact of carbon fiber springs in ankle-foot orthoses]

BACKGROUND

Patients with calf muscle insufficiency are often dependent on ankle-foot orthoses (AFO). The orthosis should improve walking and posture and should prevent structural deformities. AFOs are usually manufactured with a dorsiflexion stop. In the current study, orthoses with a dorsal carbon fiber spring were compared with the classic design.

PATIENTS AND METHODS

Five patients with spina bifida, one with poliomyelitis, and one with a tibial nerve block took part in the study. All participants underwent a 3-D gait analysis including data collection of kinematics (VICON) and kinetics (Kistler).

RESULTS

It was found that the use of a carbon fiber spring significantly increases the energy return during the third rocker for a push-off effect (p<0.05). The measurements showed further that the carbon spring was able to support the patient during the complete stance phase. The analysis of the ankle and knee kinematics reveals that the spring contributes to a more physiological gait (p<0.05).

CONCLUSION

This investigation showed that the use of a carbon spring and the alignment positively influenced the gait pattern during the stance phase.

Formation and stability of a suspended biomimetic lipid bilayer on silicon submicrometer-sized pores

We report the fabrication of a thin silicon membrane with an array of micrometer and submicrometer pores that acts as a scaffold for suspending a lipid bilayer. We successfully deposited a lipid bilayer by the Langmuir-Blodgett method on a synthetic silicon membrane bearing arrays of pores with sizes of 1000, 650, and 300 nm. Topographic images obtained by AFM showed a suspended lipid film spanning the pores, whatever the pore size. Higher stability of bilayers supported on smaller pores was shown by AFM characterization. These results represent an important first step to creating a biomimetic environment to study cell membrane dynamics and/or in developing a biosensor.

[Drug information services for physicians and patients. Acceptance and benefits]

The growing number of medicinal products and innovations has led to great complexity in the pharmaceutical market. The variety of possible drug interactions and side effects can only be overviewed with difficulty. Therefore, it is necessary that services for physicians be offered in order to provide critically evaluated and independent drug information for pharmacotherapy. In recent decades, a series of hospital based drug information centres have been established. Their quality and usefulness for patients have been positively evaluated by the users. Many patients are also insufficiently informed on their own drug therapy. This deficit is based on a general lack in communication between the patient and physician. Patient-orientated drug information services can help strengthen patients in their drug therapy and self management of symptoms, and to improve compliance. Such services have also been positively evaluated by patients.

Short-term testing of heart rate variability in heart-transplanted children: equal to 24-h ECG recordings?

INTRODUCTION

Heart rate variability (HRV) is reduced in adults and children after cardiac transplantation. Testing of HRV has been used to assess re-innervation of the cardiac graft; its reliability in ruling out acute graft rejection is still under investigation. This study used a short-term test on HRV in 23 heart and heart-lung transplanted children and adolescents and compared the results with 24-h ECG recordings.

PATIENTS AND METHODS

Twenty-three subjects (16.3+/-4.2 yr; 10 females) underwent a 10-min HRV test at two occasions and one 24-h ECG. HRV was calculated according to the time domain method (RR interval, standard deviation of RR interval) and the frequency domain method (total power, LF and HF for assessment of sympathovagal modulation of heart rate).

RESULTS

Correlation between the short-term tests and 24-h ECG was high with regard to the frequency domain analysis of HRV. Correlation was less pronounced in the time domain method.

CONCLUSIONS

In heart and heart-lung-transplanted children and adolescents, due to reduced overall HRV short-term testing may give as reliable data as 24-h ECG. Therefore, especially when power spectral analysis has to be performed as a longitudinal assessment of re-innervation of the cardiac graft, short-term testing may offer an easily applicable and non-invasive diagnostic tool. Further studies are warranted to investigate whether HRV testing may contribute to rule out acute graft rejection.

The problems associated with the monitoring of complex workplace radiation fields at European high-energy accelerators and thermonuclear fusion facilities

The European Commission is funding within its Sixth Framework Programme a three-year project (2005-2007) called CONRAD, COordinated Network for RAdiation Dosimetry. The organisational framework for this project is provided by the European Radiation Dosimetry Group EURADOS. One task within the CONRAD project, Work Package 6 (WP6), was to provide a report outlining research needs and research activities within Europe to develop new and improved methods and techniques for the characterisation of complex radiation fields at workplaces around high-energy accelerators, but also at the next generation of thermonuclear fusion facilities. The paper provides an overview of the report, which will be available as CERN Yellow Report.

Assessing recovery in middle cerebral artery stroke using functional MRI

PRIMARY OBJECTIVE

To understand the temporal evolution of brain reorganization during recovery from stroke.

RESEARCH DESIGN

A patient who suffered left middle cerebral artery stroke 9 months earlier was studied on three occasions, approximately 1 month apart.

METHODS AND PROCEDURES

Brain activation was studied using functional Magnetic Resonance Imaging (fMRI). During each session, the patient performed a finger-to-thumb opposition task, which involved one bimanual and two unimanual conditions. Each condition consisted of overt movement of fingers and imagery of the same task.

RESULTS

With recovery, greater recruitment was observed of the affected primary motor cortex (M1) and a decrease in activation of the unaffected M1 and supplementary motor area. In addition, the widespread activation of brain areas seen during the initial session changed to a more focused pattern of activation as the patient recovered. Imagery tasks resulted in similar brain activity as overt execution pointing to imagery as a potential tool for rehabilitation.

A supraomohyoidal plexus block designed to avoid complications

Interscalene blocks of the brachial plexus are used for surgery of the shoulder and are frequently associated with complications such as temporary phrenic block, Horner syndrome or hematoma. To minimize the risk of these complications, we developed an approach that avoids medially directed needle advancement and favors spread to lateral regions only: the supraomohyoidal block. We tested this procedure in 11 cadavers fixed by Thiel's method. The insertion site is at the lateral margin of the sternocleidomastoid muscle at the level of the cricoid cartilage. The needle is inserted in the axis of the plexus with an angle of approximately 35 degrees to the skin, and advanced in lateral and caudal direction. Distribution of solution was determined in ten cadavers after bilateral injection of colored solution (20 and 30 ml) and followed by dissection. In an eleventh cadaver, computerized tomography and 3D reconstruction after radio contrast injection was performed. In additional five cadavers we performed Winnie's technique with bilateral injection (20 and 30 ml). Concerning the supraomohyoidal block the injection mass reached the infraclavicular region surrounded all trunks of the brachial plexus in the supraclavicular region and the suprascapular nerve in all cases. The solution did not spread medially beyond the lateral margin of the anterior scalene muscle into the scalenovertebral triangle. Therefore, phrenic nerve, stellate ganglion, laryngeal nerve nor the vertebral artery were exposed to the injected solution. Distribution was comparable with the use of 20 and 30 ml of solution. Injections on five cadavers performing the interscalene block of Winnie resulted in an extended spread medially to the anterior scalene muscle. We conclude that our method may be a preferred approach due to its safety, because no structures out of interest were reached. Solution of 20 ml is suggested to be enough for a successful block.

Atypical symptoms in patients with herpesvirus DNA detected by PCR in cerebrospinal fluid

BACKGROUND

Polymerase chain reaction (PCR) detection of herpesvirus DNA in cerebrospinal fluid (CSF) is an important tool in the diagnosis of central nervous system (CNS) syndromes. The corresponding viral infections present with diverse clinical signs, which are often classical although no sign can be considered as specific. This retrospective study aims to describe atypical symptoms in patients with herpesvirus DNA detected in CSF by PCR. A total of 3452 cerebrospinal fluid samples from patients with suspected herpesvirus infection of the CNS were investigated between 1998 and 2003 in our clinical virology laboratory. "In-house" PCRs for each herpesvirus [herpes simplex virus (HSV), varicella zoster virus (VZV), cytomegalovirus (CMV), Epstein Barr virus (EBV), or human herpes virus 6 (HHV6)] were used until 2001 and a commercially available "Herpes Consensus PCR" was used thereafter. One of the five herpesviruses investigated in this study was found in 71 (2.1%) of CSF samples (37 HSV, 14 VZV, 1 CMV, 9 EBV and 10 HHV6). These samples were obtained from 62 patients whose clinical findings were generally consistent with the PCR data. However, some little known features of herpesvirus-related symptoms, such as partial seizure associated with HSV infection, and unusual VZV or HHV6-related myelitis were also observed.

A topologically faithful, tissue-guided, spatially varying meshing strategy for the computation of patient-specific head models for endoscopic pituitary surgery simulation

This paper presents a method for tessellating tissue boundaries and their interiors, given as input a tissue map consisting of relevant classes of the head, in order to produce anatomical models for finite element-based simulation of endoscopic pituitary surgery. Our surface meshing method is based on the simplex model, which is initialized by duality from the topologically accurate results of the Marching Cubes algorithm, and which features explicit control over mesh scale, while using tissue information to adhere to relevant boundaries. Our mesh scale strategy is spatially varying, based on the distance to a central point or linearized surgical path. The tetrahedralization stage also features a spatially varying mesh scale, consistent with that of the surface mesh.

Optical manipulation of microparticles and cells on silicon nitride waveguides

We demonstrate the optical manipulation of cells and dielectric particles on the surface of silicon nitride waveguides. Glass particles with 2microm diameter are propelled at velocities of 15microm/s with a guided power of 20mW. This is approximately 20 times more efficient than previously reported, and permits to use this device on low refractive index objects such as cells. Red blood cells and yeast cells can be trapped on the waveguide and pushed along it by the action of optical forces. This kind of system can easily be combined with various integrated optical structures and opens the way to the development of new microsystems for cell sorting applications.

[A comparison of different methods of performance assessment for the course in general medicine]

A novel Federal Regulation for Basic Medical Education was issued in Germany, which requires an end of course assessment. General Practice (GP) in Duesseldorf has introduced a written examination. An accompanying study was carried out to understand whether different methods of performance evaluation would show equivalent results intraindividually. Out of the GP class 21 students were randomised to undergo an oral examination on top of the regular written examination. Furthermore their teaching practitioners have appraised these students performance in small group teaching. Finally, the students have been rated following a practical term. At the end the students have been interviewed in a focus group to investigate their preferred method of assessment. The survey of the average grades showed comparable results for the written test, the oral examination and small group teaching while the appraisal at the end of the practical term happened to be significantly higher in grade. The comparison of the individual results, however, showed a statistical spreading in all directions. For example, a poor performance in the written test can come along with excellent results in the oral examination and vice versa. The intra-class correlation across all classes has been as low as 0.1. These results support the conclusion that apparently each method can appropriately evaluate only a very specific part of the complex contents of the GP education and of students' performance. In order to properly examine the performance of GP students a combination of different evaluation methods needs to be applied. As an alternative, different skills can be examined in different practical and theoretical test situations in an OSCE.

[Imaging of the coronary arteries with multi-channel CT: a pictorial assay]

Advances in cardiac imaging with multidetector row CT allow new applications in the diagnosis of cardiac pathology. The purpose of this article is to illustrate the normal anatomy and main anatomical variants of the coronary arteries that can be detected with multi-channel CT. The images presented here were obtained using 4-channel and 16-channel multi-detector row CT units. Post-processing of CT imaging data was performed using: VRT, MPVR, and 2D curved MPR. Because of continuing technical advances, the use of CT imaging in the evaluation of cardiac disorders is likely to increase.

Orthop�dietechnik und ICP

The surgical and pharmacological treatment of cerebral palsy patients is, in many cases, complemented by orthopaedic appliances. New knowledge and materials have expanded the possibilities for orthotic treatment in the last years, but have also led to confusion on the correct technology to use in different cases. This paper presents an overview of the current orthotic methods in cerebral palsy patients. Initially, we present the different ideas and show the limitations of the treatment. Next, we consider the problem of spastic hip dislocation and the possibilities of positioning the patients. Beds and splints cut from foam allow safe positioning of severely disabled patients without the risk of pressure sores. This appliance may prevent spastic hip dislocation in the long-term. Results of a patient questionnaire are presented. The third section deals with experiences with full contact braces and differences in their construction compared to conventional corsets. Our own results from a patient questionnaire and clinical cases will be presented. The use of a full contact brace may have a positive influence on the development of the spastic scoliosis.

Prevalence and persistence of TT virus DNA in HIV1-infected individuals

BACKGROUND

TT virus (TTV) is a recently discovered virus with a high DNA prevalence in different populations. Its role in pathogenesis is uncertain, particularly in immunocompromised patients.

PATIENTS AND METHODS

Prevalence of TTV-DNA was evaluated in a cohort of HIV-infected patients and in blood donors by nested PCR, using two different primer sets: T primers, derived from the open reading frame ORF1 region N22; B primers, derived from the untranslated region (UTR). Samples positive using T primers were also tested for TTV-DNA in peripheral blood mononuclear cells (PBMC) and followed up every 4 months.

RESULTS

The overall prevalence of TTV-DNA in HIV-infected patients was 37/376 (9.8%) using T primers and 223/333 (67%) using B primers; prevalence was higher in males (167/237, 70.5% vs 56/96, 58.3%; p = 0.033) and sub-Saharan Africans (22/23, 95.6% vs 201/310, 64.8% in other areas). Discordance was also observed in blood donors: 3.8% prevalence using T primers and 51.4% using B primers (also higher in males: 57% vs 37%, p = 0.056). TTV-DNA was detected in PBMC in 20/23 (87%) TTV-positive sera. Two-thirds of the serum samples remained positive over a 2-year follow-up period.

CONCLUSION

TTV-DNA prevalence is higher when detected with primers derived from the UTR region and was highest in male and HIV-infected sub-Saharan Africans. TTV-DNA is frequently isolated in PBMC and chronic infection is common.

[Extracorporeal membrane oxygenation (ECMO) as cardiac assist device in pediatrics]

Extracorporeal membrane oxygenation (ECMO) is a common treatment for severe respiratory failure. However, ECMO can also be used as cardiac support. ECMO is the most common mechanical circulatory assist device in pediatrics, followed by pulsatile ventricular assist devices. Advantages are the simultaneous support of respiratory and hemodynamic functions and the fast bedside availability. The major disadvantage is the limited duration of therapy. The transthoracic connection of ECMO after cardiac failure in cardiothoracic surgery in childhood allows a controlled weaning on the intensive care unit. Weaning from ECMO is successful in about 45 to 80 % in cases of circulatory support; survival rates depend on patient selection, treatment protocol and indication. Bleeding problems, thromboembolic complications, hemolysis, infections, renal and neurologic complications are major problems.

Production of interleukin-18 and interleukin-12 in patients suffering from chronic hepatitis C virus infection before antiviral therapy

Interleukin-12 and -18 (IL-12 and IL-18) are known to enhance the cytotoxic T-lymphocyte response synergistically, but their precise involvement in hepatitis C virus (HCV) infection is not well known, especially for IL-18. Enzyme-linked immunosorbent assay (ELISA) was used to study the production of these cytokines in plasma and peripheral blood mononuclear cells (PBMCs) stimulated by lipopolysaccharide (LPS) of patients infected chronically with HCV before initiation of antiviral therapy. Fifty-six patients and 40 healthy controls were evaluated. Patients infected with genotype 1 or with genotype other than genotype 1 HCV had significantly a high production of plasma IL-12 compared with controls (P < 0.05). However, patients infected with genotype 1 HCV had lower levels of PBMC IL-18 than were founded in the controls (P < 0.05); plasma IL-18 also tended to be lower in this group of patients than in the controls, although nonsignificantly. Plasma IL-18 was related to hepatic histological activity (P < 0.05). The data suggest a relationship between these two cytokines and some features of HCV infection, so that their respective production in relation to the outcome of the infection deserves further study.

Local perivascular application of low amounts of a plasmid encoding for vascular endothelial growth factor (VEGF165) is efficient for therapeutic angiogenesis in pigs

Clinical trials have demonstrated therapeutic benefit in inducing angiogenesis in chronic occlusive arterial disease. The route of application mostly used was the intramuscular injection of high dosages of plasmid. Therefore, a local perivascular application of low amounts of vascular endothelial growth factor (VEGF) plasmid was used in an interventional occlusion model, and the effect of VEGF on coronary and peripheral occlusions compared in the same animal model. Coronary and peripheral arteries were chronically occluded in Pietrain pigs using a non-surgical, interventional approach. Adventitial delivery of the DNA for VEGF was performed with a needle injection catheter. The DNA was applied as lipoplexes using the novel cationic liposomes DOCSPER. Optimized transfer conditions were used. Angiography, polymerase chain reaction (PCR), reverse transcriptase-polymerase chain reaction (RT-PCR) and immunohistochemistry were undertaken within a follow-up period of 6 months. Expression of the transfected VEGF gene was observed at 1 and 3 weeks following application. The DNA was detected up to 5 months following application. Around occluded coronary arteries, there was formation of new collaterals and arterial prolongation, whereas surrounding occluded peripheral arteries there was no collateralization but development of new arterial branches was seen. Results demonstrate that the response to VEGF is also sufficient, when minimal amounts of plasmid encoding for VEGF are applied locally into the perivasculature allowing for more safety of this therapy. Comparison of treatment of chronic coronary and peripheral arterial disease revealed differences in angiogenesis following VEGF application during a total follow-up period of almost 6 months which may be related to their different developmental origins. This may have important implications for developing future therapeutic strategies using VEGF in different vessels.

[Lipomatous tumors of soft tissues in the extremities and the waist in adults]

Lipomatous tumors of the upper and lower extremities in adults are frequent and lipoma is the most common soft tissue tumor. Most have a typical appearance at imaging but presentation and management may vary based on the exact histological subtype. The purpose of this paper is to review the main clinical, radiological and histological features of the different benign and malignant lipomatous tumors.

Fulminant ischaemic colitis with atypical clinical features complicating sickle cell disease

Clinically significant ischaemic bowel injury is an exceedingly rare complication of sickle cell disease. It manifests as acute surgical abdomen and may respond to conservative treatment. An unusual fatal case of ischaemic colitis with minimal abdominal findings in a young male during a sickle cell vaso-occlusive pain crisis is described. This case demonstrates that an acute surgical abdomen should be considered in such patients who fail to respond to conservative management as untreated this condition may be fatal.

Three-dimensional echocardiography of ventricular septal defects

Three-dimensional echocardiography is increasingly available. We report our experience with 3D reconstructions of ventricular septal defects: Unique images of all different types of ventricular septal defects are reconstructed from left and right ventricular en-face views. The images are discussed according to pathological classifications. The images shown in this article include all landmarks used in pathological classifications of ventricular septal defects to distinguish the different types of the defects and their extension directions. The possibility of visualizing the whole circumference prevents the examiner from under- or overestimating the size of a defect and gives the interventionalist a useful tool for patient and device selection for interventional VSD closure.

[Coronary arterial stent implantation proceeding noncardiac surgical procedures. Is it safe; can we recommend it?]

Patients undergoing non-cardiac surgical procedures who carry coronary artery stents have to be classified as high risk patients. Perioperative myocardial infarction and severe bleeding are possible. Therefore, anaesthetic management directed by invasive monitoring, ECG ST analysis, transesophageal echocardiography and referral to an intensive care unit are absolutely justified. The urgency of the surgical procedure, perioperative risk and an antiplatelet regimen have to be discussed with the patient and the surgeon in advance. In the case of cardiac complications, rapid therapy by an interventional cardiologist must be available.

Influenza surveillance during winter 1997-1998 in Israel

BACKGROUND

Each winter influenza activity is a major cause of morbidity and mortality both in Israel and worldwide.

OBJECTIVES

To identify the influenza viruses active in Israel during the winter season and to assess the extent of influenza morbidity.

METHODS

Information was collected on a population of 18,684 individuals enrolled in two community clinics in central Israel. It included the total number of visits for acute respiratory infection--including influenza and influenza-like illness (ARI/flu-like)--during a 20 week surveillance period (23 November 1997 to 27 March 1998) and the percent of influenza virus isolates in nasopharyngeal specimens from a sample of patients with ARI/flu-like collected on a weekly basis during the same period.

RESULTS

A total of 5,947 visits for ARI/flu-like were recorded among 18,684 enrolled patients in two community clinics (18.1%). The progressive increase in the number of visits for ARI/flu-like reached a peak on week 2/98 with 597 visits and a rate of 31.95 visits per 1,000 population. After this, a decrease to the initial values was evident by week 12/98. Most affected patients were in the age groups 5-14 and 65 years and over, with a rate of 733.5 and 605.3 visits per 1,000 population, respectively. Influenza virus was isolated from 92 of the 426 nasopharyngeal specimens (21.6%). The most commonly detected strain was A/Sydney/5/97 (H3N2) like (77.2%). The peak rate of isolates was recorded at the beginning of January (01/98).

CONCLUSIONS

A/Sydney/5/97 (H3N2) like-strain was the dominant influenza virus. Its presence did not prevent the simultaneous activity of influenza A/H1N1 virus. The dynamic of the clinical disease as expressed by the weekly visit rate for ARI/flu-like was similar to the temporal pattern of the virological findings. The extent of morbidity suggests moderate epidemic activity.

Laryngeal pyogenic granulomas do not express oestrogen or progesterone receptors

The objective of this study was to determine the presence of oestrogen and/or progesterone receptors in laryngeal pyogenic granulomas and the impact of these receptors on recurrence of pyogenic granulomas. Twenty-two consecutive patients who underwent microlaryngoscopy and removal of pyogenic granulomas were studied retrospectively. The indications for surgery were airway compromise, failure of medical therapy and suspicion of malignancy. Twelve of these patients' granulomas were analysed for oestrogen and progesterone receptors. Charts were analysed for age, sex, location of the lesion, history of trauma, intubation or gastroesophageal reflux disease (GORD), airway symptoms and recurrence. Oestrogen/progesterone receptors were analysed following deparaffinization of specimens and immunostaining with prediluted anti-oestrogen receptor monoclonal antibody and anti-progesterone receptor monoclonal antibody. No sample expressed oestrogen or progesterone receptors. There were too few recurrences to detect if lack of these receptors played any role in determining outcome in this group. Most of the patients had a history of GORD, intubation or laryngeal surgery. There were 12 recurrences in four patients. All of the recurrences improved on prolonged courses of omeprazole. Pyogenic granulomas do not possess oestrogen or progesterone receptors and are unlikely to respond to hormonal therapy. Patients who have, or are being operated on for, laryngeal pyogenic granulomas should be placed on proton pump inhibitors to decrease the likelihood of recurrence.

Neuromagnetic activity in alpha and beta bands reflect learning-induced increases in coordinative stability

OBJECTIVE

To investigate how learning induced increases in stability on a syncopation task are manifest in the dynamics of cortical activity.

METHOD

Magnetoencephalography was recorded from 143 sensors (CTF Systems, Inc). A pre-training procedure determined the critical frequency (F(c)) for each subject (n=4). Subjects either syncopated or synchronized to a metronome that increased in frequency from 1.2 to 3.0 Hz in 0.2 Hz steps. The F(c) was the point at which subjects spontaneously switched from syncopation to synchronization. Subjects then underwent 100 training trials (with feedback) at F(c). Following the learning phase the pre-training procedure was repeated.

RESULTS

An increase in the F(c) occurred indicating that practice improved the stability of syncopation. The transition delay was also observed in the phase of the time-averaged signal in sensors over the contralateral sensorimotor area and in power analysis in the 8-12 Hz and 18-24 Hz frequency bands. Initially, reduced power was observed bilaterally during syncopation compared to synchronization. Following training, these differences were reduced or eliminated.

CONCLUSION

Pre-training power differences can be explained by the greater difficulty of the syncopation task. The reduction in power differences following training suggests that at the cortical level, syncopation became more similar to synchronization possibly reflecting a decrease in task and/or attention demands.

Evaluation of endovascular techniques for creating a porcine femoral artery occlusion model

PURPOSE

To determine the optimal endovascular approach to achieve long-term occlusion of large arteries, while preserving the integrity of periarterial tissue, in an animal model of ischemia.

METHODS

Femoral artery occlusions were created in 16 pigs using detachable balloons, coils, or blinded stent-grafts. Feasibility, safety, primary and long-term success, and the degree of neovascularization were determined over a 6-month period by serial angiography and histological analyses. Four animals served as untreated controls.

RESULTS

Overall primary success for all occlusion devices was 100%. The 6-month occlusion rate using detachable balloons or coils was 33% and 0%, respectively; however, all arteries occluded with blinded stent-grafts remained obstructed to the end of the study. There was no significant difference in capillary densities and collateralization of periarterial areas when occluded arteries were compared with nonoccluded controls in the same animal. No increase in collateralization was observed following endovascular arterial occlusion.

CONCLUSIONS

Percutaneous insertion of blinded stent-grafts easily, safely, and reliably creates long-term arterial occlusion in pigs, which may make this a more appropriate model for studying the effects of angiogenic factors in vivo.

HIV protease inhibitors attenuate adherence of Candida albicans to epithelial cells in vitro

Oropharyngeal candidiasis is one of the first and most commonly reported opportunistic infections of untreated AIDS patients. With the introduction of the new antiviral HAART therapy, including HIV protease inhibitors, this mucocutaneous infection is nowadays only rarely observed in treated patients. It was recently shown that HIV protease inhibitors have a direct attenuating effect on Candida albicans secreted aspartic proteinases (Saps), an investigation prompted by the fact that both Sap and HIV protease belong to the superfamily of aspartic proteinases and by the observation that mucocutaneous infections sometimes resolve even in the absence of an immunological improvement of the host. As these Saps are important fungal virulence factors and play a key role in adhesion to human epithelial cells we tried to assess the effect of the HIV protease inhibitors Ritonavir, Indinavir and Saquinavir on fungal adhesion to these cells. The effect on phagocytosis by polymorphonuclear leukocytes was also assessed. Ritonavir was found to be the most potent inhibitor of fungal adhesion. A dose-dependent inhibition of adhesion to epithelial cells was found already at 0.8 microM and was significant at 4 microM or higher, at 500 microM the inhibition was about 55%. Indinavir and Saquinavir inhibited significantly at 4 microM or 20 microM, respectively; at 500 microM the inhibition was 30% or 50%. In contrast, no protease inhibitor was able to modulate phagocytosis of Candida by polymorphonuclear leukocytes. In conclusion, inhibition of Saps by HIV protease inhibitors may directly help to ease the resolution of mucosal candidiasis. In future, derivatives of HIV protease inhibitors, being more specific for the fungal Saps, may form an alternative in the treatment of mucosal candidiasis insensitive to currently available antimycotics.

Mitochondrial defects by intracellular calcium overload versus endothelial cold ischemia/reperfusion injury

Questions as to the critical stress factor and primary targets of cold ischemia/reperfusion (CIR) injury were addressed by comparing mitochondrial defects caused by (1) CIR injury and (2) intracellular Ca2+ overload. CIR was simulated in transformed human umbilical vein endothelial cell cultures (tEC) by 8 h cold anoxia in University of Wisconsin solution and reoxygenation at 37 degrees C. Intracellular Ca2+ concentrations were changed by permeabilization of suspended cells with digitonin in culture medium (RPMI, 0.4 mM Ca2+). Binding of free Ca2+ by ethylene glycol-bis(beta-aminoethylether)-N,N,N',N'-tetraacetic acid in RPMI or mitochondrial incubation medium served as controls. Extracellular Ca2+ protected the cell membrane against permeabilization. Mitochondrial functions were determined before and after permeabilization of the cell membrane. After CIR, mitochondrial respiratory capacity declined, but oxygen consumption remained coupled to adenosine triphosphate (ATP) production. In contrast, Ca2+ overload caused uncoupling of mitochondrial respiration. High intracellular Ca2+ overload, therefore, does not reproduce cold ischemia/reperfusion injury in endothelial cells.

Small angle neutron scattering and gel filtration analyses of neutrophil NADPH oxidase cytosolic factors highlight the role of the C-terminal end of p47phox in the association with p40phox

The NADPH oxidase of phagocytic cells is regulated by the cytosolic factors p47(phox), p67(phox), and p40(phox) as well as by the Rac1-Rho-GDI heterodimer. The regulation is a consequence of protein-protein interactions involving a variety of protein domains that are well characterized in signal transduction. We have studied the behavior of the NADPH oxidase cytosolic factors in solution using small angle neutron scattering and gel filtration. p47(phox), two truncated forms of p47(phox), namely, p47(phox) without its C-terminal end (residues 1-358) and p47(phox) without its N-terminal end (residues 147-390), and p40(phox) were found to be monomeric in solution. The dimeric form of p67(phox) previously observed by gel filtration experiments was confirmed. Our small angle neutron scattering experiments show that p40(phox) binds to the full-length p47(phox) in solution in the absence of phosphorylation. We demonstrated that the C-terminal end of p47(phox) is essential in this interaction. From the comparison of the presence or absence of interaction with various truncated forms of the proteins, we confirmed that the SH3 domain of p40(phox) interacts with the C-terminal proline rich region of p47(phox). The radii of gyration observed for p47(phox) and the truncated forms of p47(phox) (without the C-terminal end or without the N-terminal end) show that all these molecules are elongated and that the N-terminal end of p47(phox) is globular. These results suggest that the role of amphiphiles such as SDS or arachidonic acid or of p47(phox) phosphorylation in the elicitation of NADPH oxidase activation could be to disrupt the p40(phox)-p47(phox) complex rather than to break an intramolecular interaction in p47(phox).

[Value of volume rendering in musculo-skeletal disorders]

Three dimensional imaging is increasingly important for evaluation of anatomic relationships and extent of disease, for treatment planning and for follow-up evaluation. The volume rendering technique allows creation of accurate 3D images that can be used for several clinical applications especially in musculo-skeletal disorders such as evaluation of tumors or fractures. This article describes the methods used for volume rendering technique and focuses on the specific aspects of volume rendering applied to musculo-skeletal applications.

Ventricular assist devices in pediatrics

The implantation of a mechanical circulatory device for end-stage ventricular failure is a possible therapeutic approach in adult and pediatric cardiac surgery and cardiology. The aim of this article is to present mechanical circulatory assist devices used in infants and children with special emphasis on extracorporeal membrane oxygenation, Berlin Heart assist device, centrifugal pump and Medos assist device. The success of long-term support with implantable ventricular assist devices in adults and children has led to their increasing use as a bridge to transplantation in patients with otherwise non-treatable left ventricular failure, by transforming a terminal phase heart condition into a treatable cardiopathy. Such therapy allows rehabilitation of patients before elective cardiac transplantation (by removing contraindications to transplantation mainly represented by organ impairment) or acting as a bridge to recovery of the native left ventricular function (depending on underlying cardiac disease). Treatment may also involve permanent device implantation when cardiac transplantation is contraindicated. Indications for the implantation of assisted circulation include all states of cardiac failure that are reversible within a variable period of time or that require heart transplantation. This article will address the current status of ventricular assist devices by examining historical aspects of its development, current technical issues and clinical features of pediatric ventricular assist devices, including indications and contraindications for support.

BDCA-2, BDCA-3, and BDCA-4: three markers for distinct subsets of dendritic cells in human peripheral blood

We have generated a panel of mAbs that identify three presumably novel human dendritic cell Ags: BDCA-2, BDCA-3, and BDCA-4. In blood, BDCA-2 and BDCA-4 are expressed on CD11c(-) CD123(bright) plasmacytoid dendritic cells, whereas BDCA-3 is expressed on small population of CD11c(+) CD123(-) dendritic cells. All three Ags are not detectable on a third blood dendritic cell population, which is CD1c(+) CD11c(bright) CD123(dim), or on any other cells in blood. BDCA-4 is also expressed on monocyte-derived and CD34(+) cell-derived dendritic cells. Expression of all three Ags dramatically changes once blood dendritic cells undergo in vitro maturation. BDCA-2 is completely down-regulated on plasmacytoid CD11c(-) CD123(bright) dendritic cells, expression of BDCA-3 is up-regulated on both plasmacytoid CD11c(-) CD123(bright) dendritic cells and CD1c(+) CD11c(bright) CD123(dim) dendritic cells, and expression of BDCA-4 is up-regulated on CD1c(+) CD11c(bright) CD123(dim) dendritic cells. BDCA-2 is rapidly internalized at 37 degrees C after mAb labeling. The three presumably novel Ags serve as specific markers for the respective subpopulations of blood dendritic cells in fresh blood and will be of great value for their further analysis and to evaluate their therapeutic potential.

An unusual variant of composite lymphoma: a short case report and review of the literature

We recently encountered an unusual case of composite lymphoma arising in a 73-year-old man with a history of follicular small cleaved cell lymphoma. The neoplasm was composed of follicular small cleaved cell lymphoma and nodular sclerosing Hodgkin disease within a single groin lymph node. In addition to morphologic evidence, the immunologic studies performed in this case demonstrated the simultaneous occurrence of 2 separate lymphocytic proliferations. To the best of our knowledge, only one such histologic type has been reported in the literature.1 Hodgkin lymphoma can develop in patients with non-Hodgkin disease and vice versa, especially after treatment. The simultaneous occurrence of Hodgkin disease and non-Hodgkin lymphoma in a single lymph node is extremely rare. In this article, the relationship between Hodgkin disease and non-Hodgkin lymphoma is explored, possible explanations for the occurrence of composite lymphoma are discussed, and the literature is reviewed.

Spatiotemporal analysis of neuromagnetic events underlying the emergence of coordinative instabilities

A full-head 143-channel superconducting quantum interference device was used to study changes occurring in the magnetic activity of the human brain during performance of an auditory-motor coordination task in which the rate of coordination was systematically increased. Previous research using the same task paradigm demonstrated that spontaneous switches in timing behavior that arise with higher coordination rates are accompanied by qualitative changes in spatiotemporal brain activity measured by electro- and magnetoencephalography. Here we show how these patterns can be decomposed into basic physiological events, i.e., evoked brain responses to acoustic tones and self-initiated finger movements. The frequency dependence of the amplitudes of these component responses may shed new light onto why spontaneous timing transitions occur in the first place.

Functionally defined CD164 epitopes are expressed on CD34(+) cells throughout ontogeny but display distinct distribution patterns in adult hematopoietic and nonhematopoietic tissues

Three distinct classes of epitopes on human CD164 have been identified. Two of these, recognized by the monoclonal antibodies 105A5 and 103B2/9E10, are the CD164 class I and class II functionally defined epitopes, which cooperate to regulate adhesion and proliferation of CD34(+) cell subsets. In this article, we demonstrate that these 2 CD164 epitopes are expressed on CD34(+) cells throughout ontogeny, in particular on CD34(+ )cell clusters associated with the ventral floor of the dorsal aorta in the developing embryo and on CD34(+) hematopoietic precursor cells in fetal liver, cord blood, and adult bone marrow. While higher levels of expression of these CD164 epitopes occur on the more primitive AC133(hi)CD34(hi)CD38(lo/-) cell population, they also occur on most cord blood Lin(-)CD34(lo/-)CD38(lo/- )cells, which are potential precursors for the AC133(hi)CD34(hi)CD38(lo/-) subset. In direct contrast to these common patterns of expression on hematopoietic precursor cells, notable differences in expression of the CD164 epitopes were observed in postnatal lymphoid and nonhematopoietic tissues, with the class I and class II CD164 epitopes generally exhibiting differential and often reciprocal cellular distribution patterns. This is particularly striking in the colon, where infiltrating lymphoid cells are CD164 class I-positive but class II-negative, while epithelia are weakly CD164 class II-positive. Similarly, in certain lymphoid tissues, high endothelial venules and basal and subcapsular epithelia are CD164 class II-positive, while lymphoid cells are CD164 class I-positive. It therefore seems highly likely that these CD164 class I and II epitopes will mediate reciprocal homing functions in these tissue types.

Theory of the relation between human brain activity (MEG) and hand movements

Earlier research established that spontaneous changes in human sensorimotor coordination are accompanied by qualitative changes in the spatiotemporal dynamics of neural activity measured by multisensor electroencephalography and magnetoencephalography. More recent research has demonstrated that a robust relation exists between brain activity and the movement profile produced. In particular, brain activity has been shown to correlate strongly with movement velocity independent of movement direction and mode of coordination. Using a recently developed field theoretical model of large-scale brain activity itself based on neuroanatomical and neurophysiological constraints we show here how these experimental findings relate to the field theory and how it is possible to reconstruct the movement profile via spatial and temporal integration of the brain signal. There is a unique relation between the quantities in the theory and the experimental data, and fit between the shape of the measured and the reconstructed time series for the movement is remarkably good given that there are no free parameters.