X-ray 3D imaging-based microunderstanding of granular mixtures: Stiffness enhancement by adding small fractions of soft particles

This research focuses on performing ultrasound propagation measurements and micro-X-ray computed tomography (µXRCT) imaging on prestressed granular packings prepared with biphasic mixtures of monodisperse glass and rubber particles at different compositions/fractions. Ultrasound experiments employing piezoelectric transducers, mounted in an oedometric cell (complementing earlier triaxial cell experiments), are used to excite and detect longitudinal ultrasound waves through randomly prepared mixtures of monodisperse stiff/soft particles. While the fraction of the soft particles is increasing linearly from zero, the effective macroscopic stiffness of the granular packings transits nonlinearly and nonmonotonically toward the soft limit, remarkably via an interesting stiffer regime for small rubber fractions between 0.1 ≲ ν ≲ 0.2. The contact network of dense packings, as accessed from µXRCT, plays a key role in understanding this phenomenon, considering the structure of the network, the chain length, the grain contacts, and the particle coordination. While the maximum stiffness is due to surprisingly shortened chains, the sudden drop in elastic stiffness of the mixture packings, at ν ≈ 0.4, is associated with chains of particles that include both glass and rubber particles (soft chains); for ν ≲ 0.3, the dominant chains include only glass particles (hard chains). At the drop, ν ≈ 0.4, the coordination number of glass and rubber networks is approximately four and three, respectively, i.e., neither of the networks are jammed, and the chains need to include particles from another species to propagate information.

[Degenerative cervical spine diseases: fusion vs. total disc replacement : What can be done when?]

Motion preserving surgery within the cervical spine may be performed by special implants, for example, c spine disc prosthesis or total disc replacement (cTDR), or by simple decompression of the cervical nerve roots. However, also fusion surgery may be performed with good results. Here, we summarize indications as well as contraindications for motion preserving techniques and indications for fusion surgery. cTDR is indicated in special cases of soft disc herniation, especially in younger individuals without signs of myelopathy. Posterior decompression may be used as an alternative, especially if anterior surgery is not possible. If degeneration is severe, in the presence of kyphosis, severe canal encroachment, instability, and in cases of myelopathy, cervical spine fusion seems to be the better way.

The Influence of Micronutrients on Cognitive Function and Performance

There has been much media speculation (often sensationalist and conflicting) regarding the potential influence of micronutrients on cognitive function and performance. Our aim was to identify the micronutrients specifically implicated in cognitive function and to review the literature to identify original sources underlying the media coverage. Literature searches were carried out to identify recent clinical trials, reviews, editorials and meetings describing the biochemical and physiological role of individual micronutrients. No attempt was made to grade the evidence. The searches confirmed that the water-soluble vitamins (B group and C), together with the minerals, calcium, magnesium and zinc, are most relevant to cognitive performance. Clinical evidence revealed that marginal deficiencies of one or more of these micronutrients are not uncommon, even in the developed countries, and that such deficiencies may affect cognitive performance, especially in vulnerable groups such as the elderly and those individuals who are exposed to occupational pressures and a stressful lifestyle.

Treatment of traumatized victims of war and torture: a randomized controlled comparison of narrative exposure therapy and stress inoculation training

BACKGROUND

The aim of the present randomized controlled trial was to compare the outcome of 2 active treatments for posttraumatic stress disorder (PTSD) as a consequence of war and torture: narrative exposure therapy (NET) and stress inoculation training (SIT).

METHODS

Twenty-eight PTSD patients who had experienced war and torture, most of them asylum seekers, received 10 treatment sessions of either NET or SIT at the Outpatient Clinic for Refugees, University of Konstanz, Germany. Posttests were carried out 4 weeks after treatment, and follow-up tests were performed 6 months and 1 year after treatment. The main outcome measure was the PTSD severity score according to the Clinician-Administered PTSD Scale (CAPS) at each time point.

RESULTS

A significant reduction in PTSD severity was found for NET, but not for SIT. A symptom reduction in the NET group occurred between pretest and the 6-month follow-up examination, the effect size being d = 1.42 (for SIT: d = 0.12), and between pretest and the 1-year follow-up, the effect size being d = 1.59 (for SIT: d = 0.19). The rates and scores of major depression and other comorbid disorders did not decrease significantly over time in either of the 2 treatment groups.

CONCLUSIONS

The results indicate that exposure treatments like NET lead to a significant PTSD symptom reduction even in severely traumatized refugees and asylum seekers.

Expression of platelet-bound stromal cell-derived factor-1 in patients with non-valvular atrial fibrillation and ischemic heart disease

AIMS

Blood cell infiltration and inflammation are involved in atrial remodelling during atrial fibrillation (AF) although the exact mechanisms of inflammatory cell recruitment remain poorly understood. Platelet-bound stromal cell-derived factor-1 (SDF-1) is increased in cases of ischemic myocardium and regulates recruitment of CXCR4(+) cells on the vascular wall. Whether platelet-bound SDF-1 expression is differentially influenced by non-valvular paroxysmal or permanent atrial fibrillation (AF) in patients with stable angina pectoris (SAP) or acute coronary syndrome (ACS) has not been reported so far.

METHODS AND RESULTS

A total of 1291 consecutive patients with coronary artery disease (CAD) undergoing coronary angiography were recruited. Among the patients with SAP, platelet-bound-SDF-1 is increased in patients with paroxysmal AF compared with SR or to persistent/permanent AF (P < 0.05 for both). Platelet-bound SDF-1 correlated with plasma SDF-1 (r = 0.488, P = 0.013) in patients with AF and ACS, which was more pronounced among patients with persistent AF (r = 0.842, P = 0.009). Plasma SDF-1 was increased in persistent/permanent AF compared with SR. Patients with ACS presented with enhanced platelet-bound-SDF-1 compared with SAP. Interestingly, among patients with ACS, patients with paroxysmal or persistent/permanent AF presented with an impaired platelet-bound SDF-1 expression compared with patients with SR.

CONCLUSIONS

Differential expression of platelet-bound and plasma SDF-1 was observed in patients with AF compared with SR which may be involved in progenitor cell mobilization and inflammatory cell recruitment in patients with AF and ischemic heart disease. Further in vivo studies are required to elucidate the role of SDF-1 in atrial remodeling and the atrial fibrillation course.

Transgenerational impact of intimate partner violence on methylation in the promoter of the glucocorticoid receptor

Prenatal exposure to maternal stress can have lifelong implications for psychological function, such as behavioral problems and even the development of mental illness. Previous research suggests that this is due to transgenerational epigenetic programming of genes operating in the hypothalamic-pituitary-adrenal axis, such as the glucocorticoid receptor (GR). However, it is not known whether intrauterine exposure to maternal stress affects the epigenetic state of these genes beyond infancy. Here, we analyze the methylation status of the GR gene in mothers and their children, at 10-19 years after birth. We combine these data with a retrospective evaluation of maternal exposure to intimate partner violence (IPV). Methylation of the mother's GR gene was not affected by IPV. For the first time, we show that methylation status of the GR gene of adolescent children is influenced by their mother's experience of IPV during pregnancy. As these sustained epigenetic modifications are established in utero, we consider this to be a plausible mechanism by which prenatal stress may program adult psychosocial function.

Men who have sex with men: estimating the size of at-risk populations in London primary care trusts

The objective of this study was to estimate local at-risk populations of men who have sex with men (MSM) in London primary care trusts (PCTs) to inform the commissioning of targeted health interventions. Estimated population size and prevalence of diagnosed HIV in MSM in all of London were calculated using data from the British National Survey of Sexual Attitudes and Lifestyles (NATSAL), Greater London Authority population estimates and the annual survey of diagnosed MSM (Survey of Prevalent HIV Infections Diagnosed [SOPHID]). Estimated MSM population sizes at the PCT level were calculated using un-weighted and SOPHID-weighted methods and methods discussed. Four-fifths of MSM with diagnosed HIV infection in Greater London lived in inner London. Estimated population size of MSM 16-44 years in inner London was 66,000; estimated overall prevalence of diagnosed HIV infection among MSM was 9.5%. Our models show substantial variation at the PCT level between the two methods. Using the SOPHID-weighted method MSM account for up to 16% of the male population in some London PCTs, compared with as low as 3% in others. We provide a novel method of estimating at-risk MSM populations living in inner London PCTs indicating that proportions of MSM vary widely between PCTs. Significant proportions of MSM among the resident populations in several PCTs warrant inclusion of MSM health needs in core PCT prevention and service programming. In light of data source limitations further validation studies are needed.

Script-driven imagery of self-injurious behavior in patients with borderline personality disorder: a pilot FMRI study

OBJECTIVE

Self-injurious behavior (SIB) is one of the most distinctive features of borderline personality disorder (BPD) and related to impulsivity and emotional dysregulation.

METHOD

Female patients with BPD (n = 11) and healthy controls (n = 10) underwent functional magnetic resonance imaging while listening to a standardized script describing an act of self-injury. Experimental sections of the script were contrasted to the neutral baseline section and group-specific brain activities were compared.

RESULTS

While imagining the reactions to a situation triggering SIB, patients with BPD showed significantly less activation in the orbitofrontal cortex compared with controls. Furthermore, only patients with BPD showed increased activity in the dorsolateral prefrontal cortex during this section and a decrease in the mid-cingulate while imagining the self-injurious act itself.

CONCLUSION

This pattern of activation preliminary suggests an association with diminished emotion regulation, impulse control as well as with response selection and reappraisal during the imagination of SIB.

Setting up an enhanced surveillance of newly acquired hepatitis C infection in men who have sex with men: a pilot in London and South East region of England

Preliminary findings suggest ongoing HCV transmission among MSM infected with human immunodeficiency virus (HIV) and that enhanced surveillance for newly acquired HCV in MSM is feasible.

Setting up an enhanced surveillance of newly acquired hepatitis C infection in men who have sex with men: a pilot in London and South East region of England

We describe the implementation of an enhanced surveillance pilot for newly acquired hepatitis C (HCV) in men who have sex with men (MSM) in London and the South East region of England. Preliminary findings suggest ongoing HCV transmission among MSM infected with human immunodeficiency virus (HIV) and that enhanced surveillance for newly acquired HCV in MSM is feasible.

Increase in diagnosed newly acquired hepatitis C in HIV-positive men who have sex with men across London and Brighton, 2002-2006: is this an outbreak?

OBJECTIVES

To determine the incidence of diagnosed newly acquired hepatitis C virus (HCV) in HIV-positive men who have sex with men (MSM) across London and Brighton in order to inform public health interventions.

METHODS

Cases were defined as MSM attending London and Brighton HIV/genitourinary medicine clinics from January 2002 to June 2006, with HCV PCR RNA or antibody positive, and a negative HCV test in the previous three years. The yearly number of cases and HCV screening policy in MSM were examined. A negative binomial regression model was used to estimate HCV incidence density rate ratio and 95% CI.

RESULTS

20 out of 38 clinics provided information, covering 84% of the HIV-positive MSM workload in London and 100% in Brighton. The estimated overall incidence was 9.05 per 1000 HIV-positive MSM patient-years. It increased from 6.86 per 1000 in 2002 to 11.58 per 1000 during January-June 2006. Incidence at clinics ranged from 0 to 15.4 (median 6.52) per 1000 HIV-positive MSM patient-years. There was some evidence of difference in the incidence and trend (p = 0.02) in each clinic. The average annual rise in incidence of HCV was 20% (95% CI 4% to 39%, p = 0.001). There was little evidence of such transmission among MSM with negative or unknown HIV status.

CONCLUSIONS

HCV incidence clearly increased among HIV-positive MSM in London and Brighton during January 2002 to June 2006. Prospective enhanced surveillance of HCV in MSM, including HIV status and behavioural risk factors, is recommended to help inform control measures and better determine the frequency of transmission in all MSM.

The role of vitamins and minerals in energy metabolism and well-being

Physicians are frequently confronted with patients complaining of fatigue, tiredness and low energy levels. In the absence of underlying disease, these symptoms could be caused by a lack of vitamins and minerals. Certain risk groups like the elderly and pregnant women are well-recognized. Our aim was, therefore, to find out if other, less well-established groups might also be at risk. Thus, the objectives of this review are: to describe the inter-relationship between micronutrients, energy metabolism and well-being; identify risk groups for inadequate micronutrient intake; and explore the role of micronutrient supplementation in these groups. A review of the literature identified an important group at risk of inadequate micronutrient intake: young adults, often women, with a demanding lifestyle who are physically active and whose dietary behaviour is characterized by poor choices and/or regular dieting. Micronutrient supplementation can alleviate deficiencies, but supplements must be taken for an adequate period of time.

[Hemivertebra resection in congenital scoliosis -- early correction in young children]

BACKGROUND

Congenital scoliosis due to hemivertebrae usually progresses during further growth and leads to severe deformities. Early correction in young children is therefore required.

PATIENTS

Thirty-six hemivertebrae in 33 children aged 1 to 6 years (average 3 years 5 months) underwent surgical intervention. Mean follow-up was 4.5 years (2 months to 13 years).

METHODS

The hemivertebra was resected by a posterior approach. The gap after resection was closed by compression via a transpedicular instrumentation, thus correcting the scoliotic deformity.

RESULTS

Mean Cobb angle of the main curve was 45.9 degrees preoperatively, 11.9 degrees postoperatively, and 9.9 degrees at latest follow-up. The compensatory cranial curve improved spontaneously from 18.4 degrees preoperatively to 5.0 degrees postoperatively and 3.7 degrees at latest follow-up. The compensatory caudal curve improved from 21.3 degrees to 6.7 and 5.4 degrees. The angle of kyphosis was 22.8 degrees preoperatively, 8.9 degrees postoperatively, and 6.8 degrees at latest follow-up. There was one infection, 2 pedicle fractures, and 3 implant failures. In 3 patients additional operations were performed due to new developing deformities.

CONCLUSION

Correction surgery of congenital scoliosis should be performed early before the development of severe local deformities and secondary structural changes. Posterior resection of the hemivertebrae with transpedicular instrumentation allows for early intervention in very young children. Excellent correction in both the frontal and sagittal planes, and a short segment of fusion allow for normal growth in the unaffected parts of the spine.

[Preoperative planning and computer assisted surgery in ankylosing spondylitis]

AIM

The following study describes a technique for preoperative planning and computer-assisted correction osteotomy in the treatment of ankylosing spondylitis. The effect on the overall sagittal profile is evaluated.

METHOD

Kyphosis was corrected by a posterior closing wedge osteotomy. Angle and localisation of the wedge were exactly planned preoperatively and transferred to a navigation system. The osteotomy was then performed along the premarked lines with image-guided tools. Nine patients aged 40 to 61 years (average 46 years) were operated on. Follow-up time averaged 12 months (1 to 33 months).

RESULTS

The planned angle of the wedge osteotomy was an average of 30 degrees (range 24 degrees to 40 degrees ) preoperatively. Postoperatively, the angle averaged 30 degrees as well (range 22 degrees to 41 degrees ). The individual difference between real and planned angle was an average of 2.7 degrees (range 1 degrees to 6 degrees ). Sacral inclination was 23 degrees preoperatively (range-- 6 degrees to 40 degrees ) and was corrected to 40 degrees (range 27 degrees to 49 degrees ). Anterior displacement of the gravity line averaged 112 mm preoperatively (range 47 to 196 mm) and was corrected to 31 mm (range--7 to 135 mm) postoperatively and 38 mm (range-- 21 to 137 mm) at latest follow-up.

CONCLUSION

Precise preoperative planning and correction osteotomy exactly according to this planning allow for an excellent correction of the sagittal profile even in severe ankylosing spondylitis. Pelvic tilt and gravity line are normalised, the patient is able to adopt an ergonomic upright position. Navigation facilitates the intraoperative transfer of the preoperative planning.

Anatomische Reposition und monosegmentale Fusion bei hochgradiger dysplastischer Spondylolisthese L5/S1

INTRODUCTION

Developmental spondylolisthesis leads to lumbosacral kyphosis with retroversion of the sacrum and lumbar hyperlordosis. The overall sagittal profile of the spine is affected. The deformity is progressive during growth. This retrospective study describes a technique for complete reduction with clinical and radiological evaluation.

PATIENTS

Thirty-four patients (mean age 16 years 3 months, 10 males, 24 females) with severe developmental spondylolisthesis L5/S1 (Meyerding grades 3 to 5) were operated on between February 1997 and July 2002.

METHOD

Reduction was achieved by temporary transpedicular instrumentation of L4. These screws were removed at the end of the operation or 12 weeks later.

RESULTS

Mean slippage was corrected from 76 % preoperatively to 10 % postoperatively. Segmental kyphosis L5/S1 improved from + 21 degrees preoperatively to - 7 degrees postoperatively. Sacral inclination was 34 degrees preoperatively, 43 degrees postoperatively, and 47 degrees at latest follow-up. 76 % of the patients were pain free at the latest follow-up. In 4 patients a fusion at L4/5 was performed due to subsequent decompensation.

CONCLUSION

The technique described allows for a nearly anatomic reduction with correction of slippage as well as segmental kyphosis. Correction of the local deformity with monosegmental fusion L5/S1 improves dramatically the overall sagittal profile of the spine. Fusion of the primarily healthy segment L4/5 can be avoided.

[One decade of functional imaging in schizophrenia research. From visualisation of basic information processing steps to molecular-genetic oriented imaging]

Modern neuroimaging techniques such as magnetic resonance imaging (MRI) and positron emission tomography (PET) have contributed tremendously to our current understanding of psychiatric disorders in the context of functional, biochemical and microstructural alterations of the brain. Since the mid-nineties, functional MRI has provided major insights into the neurobiological correlates of signs and symptoms in schizophrenia. The current paper reviews important fMRI studies of the past decade in the domains of motor, visual, auditory, attentional and working memory function. Special emphasis is given to new methodological approaches, such as the visualisation of medication effects and the functional characterisation of risk genes.

Should a low prevalence of asymptomatic Chlamydia trachomatis infection in gay men attending HIV clinics discourage from opportunistic screening?

Genitourinary (GU) medicine notifications for homosexually acquired Chlamydia trachomatis (CT) infections show a 414% increase from 1996 to 2002. However, little is known about the prevalence of CT in men who have sex with men (MSM) outside GU medicine settings. Behavioural studies show that MSM with diagnosed HIV infection continue to engage in high-risk sexual behaviour with the risk for sexually transmitted infections (STI) acquisition and HIV transmission. This study analysed the results of urine-based CT screening in MSM attending a London HIV clinic in order to inform local policy on the benefit and patients' acceptability of opportunistic screening. Among men screened, 1.9% (2/107) had asymptomatic CT infection. Screening was well accepted and practical to be implemented in the clinic routine. It is unclear whether isolated routine urine screening is cost effective in the context of HIV prevention. HIV clinics should incorporate a public health perspective and actively contribute to HIV prevention by addressing sexual health and scope opportunities for STI screening.

Molecular markers reveal extensive intraspecific below-ground overlap of silver fir fine roots

Fine roots are expected to be important determinants of plant competition, but very little is known about the extent of root system overlap. Here, we describe the application of two highly variable plastide microsatellites to study the fine root distribution of tree individuals in a silver fir forest. We demonstrate that the spread of fine roots exceeds the width of above-ground parts, and that fine root overlaps among neighbouring trees are extensive both laterally and in depth. This approach will help to improve models of below-ground competition and will facilitate estimations of fine root biomass and thus of below-ground C pools.

Bildgebende Darstellung neurokognitiver Dysfunktionen bei der Aufmerksamkeitsdefizit-/Hyperaktivit�tsst�rung

Attention Deficit Hyperactivity Disorder (ADHD) is a neurobiological disorder of early childhood onset. Defining symptoms are chronic impairments of attention, impulse control and motor hyperactivity that frequently persist until adulthood. Miscellaneous causes of the disorder have been discussed. Accumulating evidence from imaging- and molecular genetic studies strengthened the theory of ADHS being a predominantly inherited disorder of neurobiological origin. In the last 15 years, non-invasive brain imaging methods were successfully implemented in pediatric research. Functional magnetic resonance imaging studies gave major insight into the neurobiological correlates of executive malfunction, inhibitory deficits and psychomotoric soft signs. These findings are in good accordance with brain morphometric data indicating a significant volumetric decrease of major components of striato-thalamo-cortical feedback loops, primarily influencing prefrontal executive functioning (e.g. basal ganglia). Empirical evidence points to a broad array of associated behavioral disturbances like deficient visuomotor abilities and oculomotor dysfunctions. This paper reviews the current empirical evidence derived from prior imaging studies. Special emphasis is given to the relevance of oculomotor dysfunctions in clinical and research settings, as well as their assessment in the MR environment.

Alcohol-associated stimuli activate the ventral striatum in abstinent alcoholics

Alcohol-associated cues may act as conditioned stimuli that activate the brain reward system and motivate alcohol intake in alcoholics. Alcohol-associated visual stimuli were presented during functional magnetic resonance imaging. An activation of the ventral putamen was observed in alcoholics but not in control subjects. Patients with a strong activation of the ventral putamen relapsed during the next three months. This observation supports the hypothesis that alcohol use affects areas involved in brain reward circuits and that their stimulus-induced activation may be associated with an increased risk for relapse.

[Homosexual pedophilia and functional networks - An fMRI case report and literature review]

Pedophilia is a complex bio-psycho-social disorder often associated with serious offending. Knowledge about neurobiological correlates that could serve as diagnostic and maybe even as prognostic markers is limited. FMRI examination, which shows neuronal activation in vivo and therefore represents a neurobiological correlate, was not done in pedophilia so far. We report on results of an fMRI examination in a homosexual pedophilic sex offender who differed significantly in neuronal activation during exposure to arousing visual material (young boys in underwear) from normal controls. In self assessment on a visual analogous scale the pedophilic offender scored the pictures of the boys as not being interesting and sexually not stimulating. Nevertheless presentation of the pictures of the boys resulted in the pedophilic offender in a significant activation of the attention network and the right orbitofrontal cortex. In contrast to the controls there was no activation of left hemispheric areas relevant for speech. The study design will be continued in a larger sample to examine whether there is a possible neurobiological correlate of pedophilia which can be changed by therapeutic interventions.

Excision of uranium oxide chains and ribbons in the novel one-dimensional uranyl iodates K(2)[(UO(2))3(IO(3))(4)O(2)] and Ba[(UO(2)2(IO(3))(2)O(2)](H(2)O)

The alkali metal and alkaline-earth metal uranyl iodates K(2)[(UO(2))(3)(IO(3))(4)O(2)] and Ba[(UO(2))(2)(IO(3))(2)O(2)](H(2)O) have been prepared from the hydrothermal reactions of KCl or BaCl(2) with UO(3) and I(2)O(5) at 425 and 180 degrees C, respectively. While K(2)[(UO(2))(3)(IO(3))(4)O(2)] can be synthesized under both mild and supercritical conditions, the yield increases from <5% to 73% as the temperature is raised from 180 to 425 degrees C. Ba[(UO(2))(2)(IO(3))(2)O(2)](H(2)O), however, has only been isolated from reactions performed in the mild temperature regime. Thermal measurements (DSC) indicate that K(2)[(UO(2))(3)(IO(3))(4)O(2)] is more stable than Ba[(UO(2))(2)(IO(3))(2)O(2)](H(2)O) and that both compounds decompose through thermal disproportionation at 579 and 575 degrees C, respectively. The difference in the thermal behavior of these compounds provides a basis for the divergence of their preparation temperatures. The structure of K(2)[(UO(2))(3)(IO(3))(4)O(2)] is composed of [(UO(2))(3)(IO(3))(4)O(2)](2)(-) chains built from the edge-sharing UO(7) pentagonal bipyramids and UO(6) octahedra. Ba[(UO(2))(2)(IO(3))(2)O(2)](H(2)O) consists of one-dimensional [(UO(2))(2)(IO(3))(2)O(2)](2)(-) ribbons formed from the edge sharing of distorted UO(7) pentagonal bipyramids. In both compounds the iodate groups occur in both bridging and monodentate binding modes and further serve to terminate the edges of the uranium oxide chains. The K(+) or Ba(2+) cations separate the chains or ribbons in these compounds forming bonds with terminal oxygen atoms from the iodate ligands. Crystallographic data: K(2)[(UO(2))(3)(IO(3))(4)O(2)], triclinic, space group P_1, a = 7.0372(5) A, b = 7.7727(5) A, c = 8.9851(6) A, alpha = 93.386(1) degrees, beta = 105.668(1) degrees, gamma = 91.339(1) degrees, Z = 1; Ba[(UO(2))(2)(IO(3))(2)O(2)](H(2)O), monoclinic, space group P2(1)/c, a = 8.062(4) A, b = 6.940(3) A, c = 21.67(1), beta= 98.05(1) degrees, Z = 4.

Antipsychotic drug effects on motor activation measured by functional magnetic resonance imaging in schizophrenic patients

Brain function and laterality in schizophrenia were investigated by means of a simple motor task with a self-generated left-hand sequential finger opposition (SFO) using a whole-brain high-speed (100 ms per slice) functional imaging technique. Neuroleptic-naïve, acutely ill schizophrenic patients were compared to schizophrenic patients under stable neuroleptic medication and matched controls. The goal was to evaluate both the motor function in first-episode patients and possible effects of different neuroleptic treatments on functional MRI results. Forty patients satisfying ICD 10 criteria (F20.x) for schizophrenia and sex- and age-matched healthy volunteers participated in this study. All subjects underwent fMRI examinations on a conventional 1.5 T MR unit. The primary sensorimotor cortex and the high-order supplementary motor area (SMA) were evaluated. There was a close similarity in the activation of the primary and high-order (SMA) sensorimotor areas between first-episode schizophrenic patients and controls. In contrast, a significant reduction in the overall blood oxygen level dependent (BOLD) response was seen in sensorimotor cortices (contra- and ipsilateral) in schizophrenic patients under stable medication with typical neuroleptics. This effect was not present in patients treated with atypical antipsychotics. Both antipsychotic treatments, however, led to a significant reduction in activation of the SMA region compared to controls and neuroleptic-naïve subjects. Thus, the present study provides no evidence for the localized involvement of the primary motor cortex or the SMA as a relatively stable vulnerability marker in schizophrenia. There is, however, strong evidence that neuroleptics themselves influence fMRI activation patterns and that there are major differences between typical neuroleptics and atypical antipsychotics.

[Medial medullary infarct]

Medial medullary infarct is a rare type of brain stem infarction first described in 1908. It was only since the broad use of MRI that an accurate clinical topographical correlation could be documented in survivors. We observed two patients; one of them had an anteromedial unilateral infarction in the upper medulla, and the clinical picture was characterized by contralateral hemiparesis, facial weakness, dysarthria and palatal weakness. The outcome was good. The second patient however showed a severe tetraparesis with only minor brain stem signs, secondary to bilateral anteromedian infarction with a large craniocaudal extension. He survived with severe residual impairment. The most likely cause of infarction was arteriosclerosis of the A. vertebralis and A. spinalis anterior, respectively. These two different cases suggest that the medial medullary syndrome is heterogeneous comprising small unilateral infarctions with mild clinical signs as well as large bilateral infarctions with a poor outcome.

Streptokinase-induced activation of the kallikrein-kinin system and of the contact phase in patients with acute myocardial infarction

Thrombolytic therapy in acute myocardial infarction (AMI) is hampered by a considerable reocclusion rate. Thrombin activity is enhanced, and contact-system activation via plasminemia might be possible. Prospectively we examined the contact phase and the kallikrein-kinin system and additional molecular markers of hemostasis and fibrinolysis in AMI. In 22 patients with AMI, blood sampling was performed at admission and < or =10 days afterward. Eleven patients received 1.5 Mio U streptokinase (group A) and were compared with 11 AMI patients without thrombolytic therapy (group B). All patients had systemic heparinization (5,000 IU bolus, i.v.; 1,000 IU/h, i.v.). In group A (vs. group B), the kallikrein-factor XII system was significantly activated (3 h after start of therapy): kallikrein activity 140 +/- 41 (vs. 43 +/- 8) U/L (p < 0.05); kallikrein inhibition 87 +/- 9 (vs. 113 +/- 7%; p < 0.05), and factor XII 70 +/- 14 (vs. 94 +/- 6%). C1 inhibitor and factor XII inhibition were decreased. High-molecular-weight kininogen consumption indicating bradykinin generation was enhanced (p < 0.01). In group A, thrombin activity (TAT) was increased, and a hypercoagulative state with increased fibrin degradation products (d-dimer) was found. Plasmin activation in group A was reflected by decreased plasminogen and antiplasmin levels (p < 0.01). The findings indicate that streptokinase induces activation of the contact phase-kinin system in vivo associated with a consecutive increase of thrombin and bradykinin generation. Activation of this pathway might substantially contribute to reocclusion after initially successful thrombolytic therapy and to hypotensive reactions observed after streptokinase.