A detailed investigation of the structural stability, ionic conductivity and in situ δ-phase formation of YxBi2xO3

The in situ δ-phase formation for a series of yttrium-doped Bi2O3 materials was studied by Raman spectroscopy and high resolution X-ray diffraction under variable temperature conditions. Contrary to previous reports, for dopant concentrations less than 25%, the cubic ô-phase was not fully stabilized at room temperature - tetragonal phase content was evident in both Raman spectra and powder diffractograms. Arrhenius plots also showed evidence of a phase transformation by the distinct large step change in conductivity in the temperature region where the tetragonal-cubic phase transformation was noted. Both the thermal expansion and ionic conductivity of the cubic phase decreased with increasing dopant content.

Association Between Social Vulnerability and Achieving Glycemic Control Among Pregnant Individuals With Pregestational Diabetes

OBJECTIVE

To evaluate the association between community-level social vulnerability and achieving glycemic control (defined as hemoglobin A1c [Hb A1c] less than 6.0% or less than 6.5%) among individuals with pregestational diabetes.

METHODS

We conducted a retrospective cohort of individuals with pregestational diabetes with singleton gestations from 2012 to 2016 at a tertiary care center. Addresses were geocoded using ArcGIS and then linked at the census tract to the Centers for Disease Control and Prevention's 2018 SVI (Social Vulnerability Index), which incorporates 15 Census variables to produce a composite score and four scores across thematic domains (socioeconomic status, household composition and disability, minority status and language, and housing type and transportation). Scores range from 0 to 1, with higher values indicating greater community-level social vulnerability. The primary outcome was Hb A1c less than 6.0%, and, secondarily, Hb A1c less than 6.5%, in the second or third trimesters. Multivariable Poisson regression with robust error variance was used to evaluate the association between SVI score as a continuous measure and target Hb A1c.

RESULTS

Among 418 assessed pregnant individuals (33.0% type 1; 67.0% type 2 diabetes), 41.4% (173/418) achieved Hb A1c less than 6.0%, and 56.7% (237/418) Hb A1c less than 6.5% at a mean gestational age of 29.5 weeks (SD 5.78). Pregnant individuals with a higher SVI score were less likely to achieve Hb A1c less than 6.0% compared with those with a lower SVI score. For each 0.1-unit increase in SVI score, the risk of achieving Hb A1c less than 6.0% decreased by nearly 50% (adjusted risk ratio [aRR] 0.53; 95% CI 0.36-0.77), and by more than 30% for Hb A1c less than 6.5% (adjusted odds ratio 0.67; 95% CI 0.51-0.88). With regard to specific SVI domains, those who scored higher on socioeconomic status (aRR 0.50; 95% CI 0.35-0.71) as well as on household composition and disability (aRR 0.55; 95% CI 0.38-0.79) were less likely to achieve Hb A1c less than 6.0%.

CONCLUSION

Pregnant individuals with pregestational diabetes living in an area with higher social vulnerability were less likely to achieve glycemic control, as measured by HgbA1c levels. Interventions are needed to assess whether addressing social determinants of health can improve glycemic control in pregnancy.

[Relevance and therapy of intracranial arachnoidal cysts]

Intracranial arachnoidal cysts (AC) are relevant due to their space-demanding character. The pathophysiological sequelae are dependent on the size and location of the cyst and the patient's age. Direct pressure on surrounding tissue causes headaches (meninges) or rarely seizures (brain tissue). Cerebrospinal fluid (CSF) circulation disturbances resulting from brain mass displacement with occlusion of, for example, the foramen monroi or the aqueduct cause occlusive hydrocephalus, which can lead to an increase in intracranial pressure. Depending on age, the typical primary clinical symptoms or findings differ. In adults and older children, headaches are usually the first clinical symptom. Children, in whom skull growth is not yet complete, present with a head circumference above the 97th percentile. An abnormal one-sided deflection of the calotte in the region of the underlying AC may also be present. Cranial magnetic resonance imaging (cMRI), the first-line diagnostic tool of choice to demonstrate size and location of the cysts and the surrounding intracranial structures, is of utmost importance for therapy planning. In addition, further malformations can be detected. Moreover, cMRI may also be useful for a rough assessment of increased intracranial pressure (ICP). In most symptomatic AC, surgical treatment is unavoidable. The primarily goal is to establish communication between the CSF and the cysts' content in order to effect pressure equalization. If the CSF reabsorption capacity is insufficient, it may also be necessary to implant a CSF shunt. Asymptomatic arachnoidal cysts should be strictly followed clinically and by cMRI over time. The reasonable frequency for follow-up depends on the size and location of the cyst.

Advancing the framework for considering the effects of climate change on worker safety and health

In 2009, a preliminary framework for how climate change could affect worker safety and health was described. That framework was based on a literature search from 1988-2008 that supported seven categories of climate-related occupational hazards: (1) increased ambient temperature; (2) air pollution; (3) ultraviolet radiation exposure; (4) extreme weather; (5) vector-borne diseases and expanded habitats; (6) industrial transitions and emerging industries; and (7) changes in the built environment. This article reviews the published literature from 2008-2014 in each of the seven categories. Additionally, three new topics related to occupational safety and health are considered: mental health effects, economic burden, and potential worker safety and health impacts associated with the nascent field of climate intervention (geoengineering). Beyond updating the literature, this article also identifies key priorities for action to better characterize and understand how occupational safety and health may be associated with climate change events and ensure that worker health and safety issues are anticipated, recognized, evaluated, and mitigated. These key priorities include research, surveillance, risk assessment, risk management, and policy development. Strong evidence indicates that climate change will continue to present occupational safety and health hazards, and this framework may be a useful tool for preventing adverse effects to workers.

Limits on Momentum-Dependent Asymmetric Dark Matter with CRESST-II

The usual assumption in direct dark matter searches is to consider only the spin-dependent or spin-independent scattering of dark matter particles. However, especially in models with light dark matter particles O(GeV/c^{2}), operators which carry additional powers of the momentum transfer q^{2} can become dominant. One such model based on asymmetric dark matter has been invoked to overcome discrepancies in helioseismology and an indication was found for a particle with a preferred mass of 3  GeV/c^{2} and a cross section of 10^{-37}  cm^{2}. Recent data from the CRESST-II experiment, which uses cryogenic detectors based on CaWO_{4} to search for nuclear recoils induced by dark matter particles, are used to constrain these momentum-dependent models. The low energy threshold of 307 eV for nuclear recoils of the detector used, allows us to rule out the proposed best fit value above.

Kontinuierliche Bestimmung von Mischungswärmen durch isotherme Enthalpietitration

A continuous method for determining the heats of mixing of liquid systems is described by which the complete mixing curve of a binary system, HM= ƒ(NA) is rapidly obtained by two experiments only, giving 40 or more curve points which are accurate to better than ±1%. Isothermal conditions within +0.002° to ± 0.008° are maintained by means of controlled thermoelectric cooling or heating. The air space above the liquid is completely excluded by operation at constant volume; the pure liquid B enters and the equilibrated mixture leaves the calorimeter vessel with equal velocities. A theoretical discussion of the heat balance equation of this mixing procedure, including the performance curve of the thermoelectric module, the response characteristics of the controller for the Peltier current, and the influence of excess volumes, is given. As examples for the correct operation of the heatof- mixing calorimeter described, the results at 25° for the systems acetone -chloroform, benzyl acetate -chloroform, and pyridine -chloroform are given; they agree with the literature data within the uncertainty limits reported there.

[Children with specific language impairment: electrophysiological and pedaudiological findings]

BACKGROUND

Auditory deficits may be at the core of the language delay in children with Specific Language Impairment (SLI). It was therefore hypothesized that children with SLI perform poorly on 4 tests typically used to diagnose central auditory processing disorder (CAPD) as well in the processing of phonetic and tone stimuli in an electrophysiological experiment.

MATERIAL AND METHODS

14 children with SLI (mean age 61,7 months) and 16 children without SLI (mean age 64,9 months) were tested with 4 tasks: non-word repetition, language discrimination in noise, directional hearing, and dichotic listening. The electrophysiological recording Mismatch Negativity (MMN) employed sine tones (600 vs. 650 Hz) and phonetic stimuli (/ε/ versus /e/).

RESULTS

Control children and children with SLI differed significantly in the non-word repetition as well as in the dichotic listening task but not in the two other tasks. Only the control children recognized the frequency difference in the MMN-experiment. The phonetic difference was discriminated by both groups, however, effects were longer lasting for the control children. Group differences were not significant.

CONCLUSIONS

Children with SLI show limitations in auditory processing that involve either a complex task repeating unfamiliar or difficult material and show subtle deficits in auditory processing at the neural level.

[Treatment of hydrocephalus]

CLINICAL/METHODICAL ISSUE

Modern treatment of hydrocephalus. STANDARDS OF CLINICAL AND RADIOLOGICAL METHODS: Clinically: shunting and endoscopy. Radiologically: MRT, CCT.

METHODICAL INNOVATIONS

Important innovations are gravitational valves and neuroendoscopy standing for new challenges in preoperative imaging and for sufficient interpretation of postoperative imaging.

PERFORMANCE

G-valves reduce the complication rate (especially overdrainage) in shunting significantly. While lacking appropriated clinical studies, the UK Shunt Registry still provides the best comparison between shunting and neuroendoscopy, after which the long-term revision rates of both methods are identical. The perioperative risk of endoscopic surgery seems to be higher than for shunts.

ACHIEVEMENTS

The superiority of the G-valves in chronic hydrocephalus in comparison with other valves has recently been demonstrated in a class 1 evidence-based study. The neuroendoscopy, has been,-in the absence of a contraindications -, indicated by a guidelines' committee of the German Society of Neurosurgery as method of choice in occlusive hydrocephalus alternatively to shunting.

PRACTICAL RECOMMENDATIONS

Preoperatively, to clarify etiology, comorbidity, and surgical planning, MRI is preferable; with planned neuroendoscopy as high-resolution detailed MRI of access-trajectory and region of interest. In post-operative CT or MRI (after endoscopic procedures always MRI) a differentiation between (sub-)acute and chronic hydrocephalus is important for correct interpretation of imaging: a normalization of ventricular size is physiological only in (sub-)acute hydrocephalus, in chronic hydrocephalus, yet, sign of overdrainage. In chronic hydrocephalus, ventricles shrink usually only marginally. Solely, better delineated, vertex-near cisternae are there evidence of sufficient drainage.

Simulation of existing and future electromechanical shunt valves in combination with a model for brain fluid dynamics

Several models are available to simulate raised intracranial pressure (ICP) in hydrocephalus. However, the hydrodynamic effect of an implanted shunt has seldom been examined. In this study, the simple model of Ursino and Lodi [14]is extended to include (1) the effect of a typical ball-in-cone valve, (2) the effect of the size of the diameter of the connecting tube from valve to abdomen, and (3) the concept of a controlled electromechanical shunt valve in overall cerebrospinal fluid dynamics.By means of simulation, it is shown how a shunt can lower ICP. Simulation results indicate that P and B waves still exist but at a lower ICP level and that, due to the exponential pressure-volume curve, their amplitude is also considerably lowered. A waves only develop if the valve is partially blocked. The resulting ICP is above the opening pressure of the valve, depending on the drain and resistance of the shunt.The concept of a new electromechanical shunt was more successful than the traditional mechanical valves in keeping ICP at a desired level. The influence of the patient's movements or coughing on ICP as well as the body position affecting the reference ICP, which can be measured, has not yet been modeled and should be addressed in future using suitable algorithms.

Cognitive reappraisal modulates performance following negative feedback in patients with major depressive disorder

BACKGROUND

Depressed patients show impaired performance following negative feedback; the probability of committing an error is increased immediately after an error. This deficit is assumed to be highly specific and to represent a trait marker of major depressive disorder (MDD). Inconsistencies in currently available data could reflect inter-individually different strategies to regulate negative affect. The present study examined modulation of performance following negative feedback by cognitive reappraisal to regulate aversive affect in depressed patients.

METHOD

Thirty-three depressed patients and 33 control subjects performed tasks of varying difficulty over a prolonged time. Emotional feedback was given immediately after each trial. Performance was further analysed within subgroups using cognitive reappraisal of aversive events with high and low frequency.

RESULTS

A significant group by task difficulty interaction for absolute number of subsequent errors revealed that depressed patients were especially impaired when receiving negative feedback more frequently. An increased probability of subsequent errors was shown in patients irrespective of task difficulty. Analysis of subgroups revealed higher absolute number and probability of subsequent errors only in depressed patients habitually not using cognitive reappraisal to regulate aversive emotions. Depressed patients using this strategy did not differ from controls.

CONCLUSIONS

The present results replicate the observation of impaired performance in depressed patients following failure feedback. Most importantly, a subgroup of patients who habitually rely on cognitive reappraisal of aversion-eliciting events, such as negative performance feedback, was not impaired. This modulatory influence of emotion regulation strategies on performance subsequent to negative feedback suggests that training emotion regulation in achievement situations should be incorporated in current concepts to prevent relapse.

Is it possible to minimize overdrainage complications with gravitational units in patients with idiopathic normal pressure hydrocephalus? Protocol of the randomized controlled SVASONA Trial (ISRCTN51046698)

Overdrainage is a common complication observed after shunting patients with idiopathic normal-pressure hydrocephalus (iNPH), with an estimated incidence up to 25%. Gravitational units that counterbalance intracranial pressure changes were developed to overcome this problem. We will set out to investigate whether the combination of a programmable valve and a gravitational unit (proGAV, Aesculap/Miethke, Germany) is capable of reducing the incidence of overdrainage and improving patient-centered outcomes compared to a conventional programmable valve (Medos-Codman, Johnson & Johnson, Germany). SVASONA is a pragmatic randomized controlled trial conducted at seven centers in Germany. Patients with a high probability of iNPH (based on clinical signs and symptoms, lumbar infusion and/or tap test, cranial computed tomography [CCT]) and no contraindications for surgical drainage will randomly be assigned to receive (1) a shunt assistant valve (proGAV) or (2) a conventional, programmable shunt valve (programmable Medos-Codman).We will test the primary hypothesis that the experimental device reduces the rate of overdrainage from 25% to 10%. As secondary analyses, we will measure iNPH-specific outcomes (i.e., the Black grading scale and the NPH Recovery Rate), generic quality of life (Short Form 36), and complications and serious adverse events (SAE). One planned interim analysis for safety and efficacy will be performed halfway through the study. To detect the hypothesized difference in the incidence of overdrainage with a type I error of 5% and a type II error of 20%, correcting for multiple testing and an anticipated dropout rate of 10%, 200 patients will be enrolled.The presented trial is currently recruiting patients, with the first results predicted to be available in late 2008.

Infection rate with application of an antibiotic-impregnated catheter for shunt implantation in children - a retrospective analysis

BACKGROUND

The infection rate of hydrocephalus shunts in children amounts figures of up to 25% and the according mortality rate is alarming high nowadays yet. An antibiotic impregnated shunt-catheter (AIS) was designed to reduce the incidence of shunt infections.

PATIENTS AND METHOD

In a non randomized trial 56 children were examined between January 2002 inclusive December 2007. The minimal follow-up was six months. Only children were included, who were shunted for the first time. In the study group (n=34) AIS (Bactiseal ) Codman, Johnson & Johnson, MA, Boston, USA) were used, while the control group (n=22) was provided with conventional, not-antibiotic impregnated catheters. To compare the risk profile for shunt infections, we defined, - according to the literature -, some risk factors.

RESULTS

Despite the incidence of shunt infections has been supposed to be higher according to the higher risk profile of the AIS group compared with controls, the shunt infection rate of the AIS group was lower than the shunt infection rate in the control group.

CONCLUSIONS

Apparently, AIS can reduce the incidence of shunt infections in children. Further prospective trials with a larger cohort are necessary for a statistically significant prove.

Analysis of pulse waves in intracranial pressure

In the therapy of hydrocephalus the dynamic course of the intracranial pressure (ICP) is rarely considered, although it may contain valuable diagnostic information. Several models for intracranial pressure and fluid dynamics are described. Assuming a simplified model and deriving the intracranial pressure wave relationships, this model could be partially confirmed and a characteristic dataset could be given for every patient.

Response inhibition in borderline personality disorder: event-related potentials in a Go/Nogo task

Borderline personality disorder (BPD) has been related to a dysfunction of anterior cingulate cortex, amygdala, and prefrontal cortex and has been associated clinically with impulsivity, affective instability, and significant interpersonal distress. We examined 17 patients with BPD and 17 age-, sex-, and education matched control participants with no history of Axis I or II psychopathology using event-related potentials (ERPs). Participants performed a hybrid flanker-Go/Nogo task while multichannel EEG was recorded. Our study focused on two ERP components: the Nogo-N2 and the Nogo-P3, which have been discussed in the context of response inhibition and response conflict. ERPs were computed on correct Go trials (button press) and correct Nogo trials (no button press), separately. Groups did not differ with regard to the Nogo-N2. However, BPD patients showed reduced Nogo-P3 amplitudes. For the entire group (n = 34) we found a negative correlation with the Barratt Impulsiveness Scale (BIS-10) and Becks's depression inventory (BDI). The present study is the first to examine Nogo-N2 and Nogo-P3 in BPD and provides further evidence for impaired response inhibition in BPD patients.

Executive control in obsessive-compulsive disorder: event-related potentials in a Go/Nogo task

Obsessive-compulsive disorder (OCD) has been related to a hyperactive cortico-striatal-pallidal-thalamic circuitry resulting clinically in an impaired inhibition of repetitive thoughts and behaviors. We examined thirteen patients with OCD and thirteen age-, sex-, and education matched healthy controls using event-related potentials (ERPs). Participants performed a hybrid flanker-Go/Nogo task while multichannel EEG was recorded. Our study focused on two ERP components: the Nogo-N2 and the Nogo-P3, which have been discussed in the context of response inhibition and response conflict. Artifact-free EEG-segments were used to compute ERPs on correct Go trials (button press) and correct Nogo trials (no button press), separately. Patients with OCD showed enhanced (more negative) Nogo-N2 amplitudes than controls, and a significant difference in amplitudes between Nogo-N2 and Go-N2 trials (more negative for Nogo trials) at central midline electrode positions. However, groups did not differ with regard to the Nogo-P3 and Go-P3. The present study replicates and extends previous findings of altered executive control processes in OCD patients.

Plastidic trnFUUC pseudogenes in North American genus Boechera (Brassicaceae): mechanistic aspects of evolution

The origin and maintenance of a plastidic tandem repeat next to the TRNF (UUC) gene were analyzed in the genus BOECHERA in a phylogenetic context and were compared to published analogous examples that emerged in parallel in the Asteraceae and Juncaceae, respectively. Although we identified some features common to these taxonomic groups with respect to structure and origin of the region, obvious differences were encountered, which argue against a specific mechanism or evolutionary principle underlying the parallel origin and maintenance of the TRNF-tandem repeats in those families. In contrast to the situation in the Asteraceae, no reciprocal recombinant repeat types have been observed in the Brassicaceae. Forty copy types, classified into three groups, were isolated from 103 chloroplast haplotypes of BOECHERA and it was demonstrated that they are composed of four subregions of various origins. We discuss various mutation mechanisms such as DNA replication slippage, and inter- and intrachromosomal recombination which were reported to mediate variation in copy numbers and other types of observed sequence length polymorphism. It is shown that the observed molecular structure of the tandem repeat region did not fully fit the particular patterns expected under a scenario of evolution including any of the known mechanisms. Nevertheless, it appeared that intermolecular unequal crossing-over is most likely the driving force in the evolution of this tandem repeat. However, it remains to be explained, why no reciprocal recombinant copy types have been observed. The reconstructed phylogenetic relationships among copies reflected different evolutionary scenarios as follows: (1) A single and ancient origin of copies pre-dates the radiation of BOECHERA. (2) Parallel expansion and shortening of the tandem repeat within different BOECHERA lineages. (3) Conservation of the first copy, as it was the only one present in all chloroplast haplotypes.

Outcome predictors for normal-pressure hydrocephalus

The objective of this prospective study was to find outcome predictors for better selection for treatment of normal-pressure hydrocephalus (NPH) patients. A total of 125 patients were evaluated and provided with a gravitational shunt. Cerebrospinal fluid hydrodynamics provided better predictive values if an algorithm to shunt all patients with a pressure/volume index of < 30 mL or resistance to outflow > 13 mmHg/mL x min was used. In general, outcome became worse with increasing anamnesis duration, worse preoperative clinical state, and increasing comorbidity. If one of these parameters was lower than a critical value, the shunt-responder rate was about 90% and the normally negative influence of older age was not seen. The well-known paradigm of a worse prognosis with NPH is not the result of the hydrocephalus etiology itself, but the consequence of a typical accumulation of negative outcome predictors as a consequence of the misinterpretation of normal aging and delayed adequate treatment.

On the optimal opening pressure of hydrostatic valves in cases of idiopathic normal-pressure hydrocephalus: a prospective randomized study with 123 patients

Does the opening pressure of hydrostatic shunts influence the clinical outcome for patients suffering from idiopathic normal-pressure hydrocephalus (NPH)? Between September 1997 and January 2003, 123 patients with idiopathic NPH were surgically treated by implanting a hydrostatic shunt at the Departments of Neurosurgery of the Unfallkrankenhaus Berlin and the University Homburg/Saar. As part of a prospective randomized study, all patients were examined preoperatively, postoperatively, and 1 year after the intervention. Forty-three percent of the patients showed a very good outcome, 25% good outcome, 20% fair outcome, and 12% poor outcome 1 year after the shunt implantation. Patients treated with an opening pressure rating of 50 mmH2O in the low-pressure stage of the gravitational valve showed a better outcome than those with an opening pressure of 100 or 130 mmH2O. According to present knowledge, hydrostatic shunts with an opening pressure of 50 mmH2O for the low-pressure stage are the best option for patients with idiopathic NPH. Due to the prompt switching function when the patient changes posture (lying down, standing, sitting, slanting etc.), the Miethke gravity-assisted valve (GAV) is more suitable in such cases than the Miethke Dual-Switch valve (DSV).

Gravitational valves: relevant differences with different technical solutions to counteract hydrostatic pressure

Two different technical principles of gravitational valves (G-valves) have been presented: counterbalancer and switcher G-valves. The objective of our prospective study was to look for clinically relevant differences between both. A total of 54 patients with normal-pressure hydrocephalus (NPH) were treated; 30 patients received an Aesculap-Miethke GA-Valve (GAV; counterbalancer), and in 24 patients an Aesculap-Miethke Dualswitch-Valve (DSV; switcher) was implanted. The opening pressure of the posture-independent valve was 5 cm H2O in both devices. The outcome was clearly better with the usage of the GAV than with the DSV. The frequency and severity of complications was pronounced in the DSV group. We recommend the Aesculap-Miethke-GAV valve with a low opening pressure in a posture-independent valve for patients with NPH.

Gravitational shunt management of long-standing overt ventriculomegaly in adult (LOVA) hydrocephalus

OBJECTIVES

Recently a new subtype of chronic hydrocephalus was described: long-standing overt ventriculomegaly in adults (LOVA). Experience to date has indicated that shunt therapy was contraindicated, due to over-drainage. Therefore we investigated whether this problem could be overcome using gravitational shunts.

MATERIALS AND METHODS

Thirty macrocephalic adults (17-72 years of age), suffering from progressive hydrocephalus were managed with two different gravitational shunts. The post-operative observation period was 5-87 months.

RESULTS

Only two patients developed hygromas, and only one of these required surgical shunt revision. Eighty-seven percent of patients had a long-lasting clinical improvement. Ventricular size was only slightly reduced in 29 patients. There was no correlation between reduction in ventricular size and clinical improvement.

CONCLUSION

Contrary to clinical guidelines issued to date, we demonstrate that LOVA can be treated reliably with gravitational shunts, making them a genuine alternative to endoscopic third ventriculostomy (ETV).

Does the pattern of atrophy of the Corpus callosum differ between patients with frontotemporal dementia and patients with Alzheimer's disease?

The pattern of callosal atrophy might be useful for the differentiation between frontotemporal dementia (FTD) and Alzheimer's disease (AD) in advanced cases. However, it is unclear whether the pattern of callosal atrophy differs between patients with FTD and patients with AD in mild to moderate stages. Volumetric MR images were recorded from 48 probands (12 with FTD, 12 with late-onset AD, and 24 controls). All patients were in a mild or in a moderate stage. The corpus callosum was divided into five segments. A repeated-measures analysis of variance showed that there was no difference in the pattern of callosal atrophy between the groups. We provide evidence that patients with FTD and patients with late-onset AD do not differ in the pattern of callosal atrophy on condition that: (1) FTD patients and AD patients are in a mild to moderate stage and (2) FTD patients and AD patients differ in age.

Review about Ginkgo biloba special extract EGb 761 (Ginkgo)

Ginkgo biloba extracts (EGb) are well-defined plant extracts. It has several indications as dementia, macula degeneration, tinnitus and winter depression. A review of the current and past literature about older people with Alzheimer's dementia or vascular dementia or age-associated memory impairment treated with Ginkgo biloba extract, reveals that EGb has reproducible effects on cognitive functions in Alzheimer's disease. The drug is well tolerated.

[A grading system for chronic hydrocephalus]

A generally accepted grading system for patients suffering from chronic hydrocephalus has not been established yet. Therefore we designed a new grading system, which focuses on five symptom categories: gait disturbances, mental disorder, incontinence, headache, dizziness. For each category clearly circumscribed degrees of handicaps are defined. For each degree a value between 0-6 points is assigned in concordance to the severity of handicap. To get a generally accepted validation of the obstruction, the assigned values were oriented on the values provided in Germany to evaluate the degree of obstruction for insurances.[nl]In contrast to the established gradings of Stein and Langfitt and the Black Rating Scale our grading allows a more exact acquisition of the clinical presentation of a patient. Our experiences with the grading seemingly indicate also, that it is reliable. Because the grading allows an incorporation of measurable data such as psychometric analysis or gait analysis, our grading is useful as well for everydays' practice as for scientific purpose.

[A systematic comparison of national and international dementia guidelines]

Several guidelines for the evidence-based diagnosis and treatment of dementing disorders have been published in Germany and worldwide during the last years. This review analyses the content and methodological quality of 13 recently published dementia guidelines. There are some unequivocal recommendations for diagnostic procedures (e. g. clinical evaluation, neuropsychological screening, structural brain imaging) and treatment (e. g. cholinesterase inhibitors). There is a broad range of opinions on other procedures (e. g. routine EEG, FDG PET, cognitive training). A discussion of the prevalent guideline pluralism and a pleading for regionally adapted international guidelines conclude this article.

Multi-centre assessment of the Spiegelberg compliance monitor: interim results

Analyses of a multi-centre database of 71 patients at risk of raised ICP showed that in head injured patients (n = 19) and tumour patients (n = 13) clear inverse relationships of ICP vs compliance exist. SAH patients (n = 5) appear to exhibit a biphasic relationship between ICP and compliance, however greater numbers of patients need to be recruited to this group. Patients with hydrocephalus (n = 34) show an initial decrease in compliance while ICP is less than 20 mmHg, thereafter compliance does not show a dependence upon ICP. A power analysis confirmed that sufficient numbers of patients have been recruited in the hydrocephalus group and a ROC analysis determined that a mean compliance value of 0.809 (lower and upper 95% CL = 0.725 & 0.894 resp.) was a critical threshold for raised ICP greater than 10 mmHg. Preliminary time-series analyses of the ICP and compliance data is revealing evidence that the cumulative time compliance is in a low compliance state (< 0.5 ml/mmHg), as a proportion of total monitoring time, increases more rapidly than the cumulative time ICP is greater than 25 mmHg. Before trials testing compliance thresholds can be designed, we need to consider not just the absolute threshold, but the duration of time spent below threshold. A survey may be required to identify a consensus of what is the minimum duration of raised ICP above 25 mmHg needed to instigate treatment.

Online analysis of intracranial pressure waves

Brain pressure waves, particularly B-waves, as they were described by Lundberg contain valuable diagnostic information about the patient's status. So far, this information cannot be used on a daily routine basis because manual analysis of the recorded ICP data is very time consuming. Furthermore, the analysis is only retrospective, after incidents of interest occurred. To overcome these drawbacks, an automated B-wave detection system has been developed. Using a direct spectral estimation method (so called ARMA approach) the most significant spectral components and their amplitudes in the ICP signal are identified. The frequency with the biggest amplitude inside the B-wave band is a reliable indicator of B-wave activity and can be displayed on-line on a bedside computer.

The ICP-dependency of resistance to cerebrospinal fluid outflow: a new mathematical method for CSF-parameter calculation in a model with H-Tx rats

The international accepted calculation methods concerning the cerebrospinal fluid dynamics proceed from a pressure independent resistance to cerebrospinal fluid outflow. In a new model we focus our attention on the pressure dependency of resistance. In our calculation model we are monitoring the complete pressure course p(t) over the time t during and after the infusion. The comparison of the pressure rise On(p) during the infusion and the descent Off(p) after the infusion in the same pressure level allows to construct all formulas for the compliance C(p) and resistance R(p). The simultaneous measurement of the resistance and complications during a single investigation allows minimizing the patient's exertion. In contrast to the classical methods it is not necessary that the ICP reach a plateau. Our mathematical method diverges with the description of a pressure dependent slope of the function for the resistance from the static examination models. We proved our mathematical method by the use of a dynamic infusion test in ten H-Tx rats without hydrocephalus and five hydrocephalic H-Tx rats. For that we are able to take the non-linearity of the CSF resorption into consideration.

[LOVA hydrocephalus - a new entity of chronic hydrocephalus]

The recently defined term "longstanding overt ventriculomegaly in adults" (LOVA) describes a unique entity of chronic occlusive hydrocephalus. The experiences so far using conventional DP valves were not encouraging because of a high percentage of overdrainage. The objective was to evaluate whether gravitational shunts could be used for this condition with an acceptable overdrainage risk. Twenty-three macrocephalic adults aged 17-72 years suffered from chronic progressive hydrocephalic conditions. They received two different types of gravitational shunt. Follow-up ranged from 6 months to 75 months. Only two patients presented small subdural effusions postoperatively, and only one required additional treatment for that. Eighty-two percent were shunt responders. Ventricular size was only marginally reduced in 22 of the 23 patients. There was no correlation between clinical benefit and the reduction in ventricular size. Gravitational shunts clearly have the potency for safe treatment of LOVA, significantly reducing the risk of overdrainage over conventional valves, and may be considered an equivalent alternative to third ventriculostomy.

Five years experience with gravitational shunts in chronic hydrocephalus of adults

OBJECTIVE

Gravitational shunts for management of chronic hydrocephalus are supposed to avoid or at least to reduce the risk of overdrainage. In order to find out if this hypothesis is correct, we did a prospective study and analysed the results of a series of 185 hydrocephalic adults, treated by using gravitational shunts. For the few cases in whom overdrainage occurred, we wanted to establish the reason for it. Especially it should be proven or excluded that overdrainage was caused by shortcomings of the principle of gravitational shunts. Another goal was to compare post-shunting changes of the ventricular size with clinical outcome. A comparably large study has not yet been published.

METHODS

185 adult patients who suffered from chronic hydrocephalus were shunted between 1996-2000, either using the combination of an adjustable Codmann Hakim Valve & Miethke Shunt Assistant (35 patients) or a Miethke Dual Switch Valve (150 patients). The clinical course of each patient has been followed until the end of 2000. Average follow-up time was 26 months (range 6-60 months).

RESULTS

88% of our patients were shunt responders, 70% had a good or excellent outcome. Overdrainage occurred in only 4%. It turned out that this complication was not a failure of the concept of gravitational shunts, but the result of a wrongly estimated intraperitoneal pressure. After shunting the ventricular size was reduced only marginally. In 92% of the patients the Evans-Index decreased less than 20% after the shunt insertion, but 69% of these patients had a good or excellent outcome. The most obvious difference comparing pre- and postoperative imaging was a better visibility of the high apical sulci after shunting.

CONCLUSION

In our series gravitational shunts proved to be effective in preventing overdrainage. The 4% negative exceptions are mainly avoidable. There was no correlation between outcome and ventricular size reduction, and as a rule ventricular size was only marginally reduced.

[Modern intracranial pressure measurement techniques. Basic principles and general practice]

Measurement of intracranial pressure (ICP) has to be regarded as a standard procedure in today's treatment of severe head-injured patients. Intraventricular or intraparenchymal measurement should be used. The essential value for intensive care treatment is the cerebral perfusion pressure (CPP). Its value should be kept strictly > 70 mmHg. Computer-based analysis of the ICP-signal provides further options of an online monitoring of intracranial reserve capacity and the state of autoregulation. However, until now, there are no software solutions commercially available which would allow for such advanced signal analysis--the reason might be that the potential of advanced signal analysis has only been discovered within the recent years.

Arithmetic fact retrieval and working memory in schizophrenia

Despite its importance in every-day life and vocational rehabilitation, arithmetic ability has rarely been investigated in schizophrenic patients. Those few studies reporting arithmetic deficits in schizophrenia, however, administered complex calculation tasks which drew not only on arithmetic abilities, but also on working memory resources known to be impaired in schizophrenia. In the present study, arithmetic abilities and working memory functions were investigated in schizophrenic patients (n=24) and healthy control subjects (n=24). Arithmetic fact retrieval was assessed in single-digit multiplication and corresponding division problems using a result verification task which minimized working memory demands. Problem size and the disparity of the proposed result were manipulated. The storage component of working memory was tested with a digit span forward task and the executive control component with a digit span backward as well as with verbal fluency tasks. Schizophrenic patients performed worse than controls only in the executive tasks. Digit span forward was preserved. In the arithmetic tasks, groups did not differ from each other, and a similar pattern of task manipulations was obtained. Hence, despite the executive control deficit retrieval of arithmetic facts is preserved in schizophrenia. Moreover, the same underlying cognitive processes as in control subjects are involved.

The ICP-dependency of resistance to cerebrospinal fluid outflow: a new mathematical method for CSF-parameter calculation in a model with H-TX rats

The international The simultaneous measurement of the resistance and compliance during a single investigation minimizes the patients exertion. In contrast to the classical method it is not necessary that the ICP reaches a plateau. Our mathematical method diverges with t he description of a pressure dependent slope of the function for the resistance from the static examination models. We proved our mathematical method by the use of a dynamic infusion test in 10 H-Tx rats without hydrocephalus and five hydrocephalic H-Tx rats. For that we are able to take the non linearity of the CSF resorption into consideration.

Metal ion binding and coordination geometry for wild type and mutants of metallo-beta -lactamase from Bacillus cereus 569/H/9 (BcII): a combined thermodynamic, kinetic, and spectroscopic approach

One high affinity (nm) and one low affinity (microM) macroscopic dissociation constant for the binding of metal ions were found for the wild-type metallo-beta-lactamase from Bacillus cereus as well as six single-site mutants in which all ligands in the two metal binding sites were altered. Surprisingly, the mutations did not cause a specific alteration of the affinity of metal ions for the sole modified binding site as determined by extended x-ray absorption fine structure (EXAFS) and perturbed angular correlation of gamma-rays spectroscopy, respectively. Also UV-visible absorption spectra for the mono-cobalt enzymes clearly contain contributions from both metal sites. The observations of the very similar microscopic dissociation constants of both binding sites in contrast to the significantly differing macroscopic dissociation constants inevitably led to the conclusion that binding to the two metal sites exhibits negative cooperativity. The slow association rates for forming the binuclear enzyme determined by stopped-flow fluorescence measurements suggested that fast metal exchange between the two sites for the mononuclear enzyme hinders the binding of a second metal ion. EXAFS spectroscopy of the mono- and di-zinc wild type enzymes and two di-zinc mutants provide a definition of the metal ion environments, which is compared with the available x-ray crystallographic data.

The interaction of bovine adrenodoxin with CYP11A1 (cytochrome P450scc) and CYP11B1 (cytochrome P45011beta ). Acceleration of reduction and substrate conversion by site-directed mutagenesis of adrenodoxin

The kinetics of protein-protein interaction and heme reduction between adrenodoxin wild type as well as eight mutants and the cytochromes P450 CYP11A1 and CYP11B1 was studied in detail. Rate constants for the formation of the reduced CYP11A1.CO and CYP11B1.CO complexes by wild type adrenodoxin, the adrenodoxin mutants Adx-(4-108), Adx-(4-114), T54S, T54A, and S112W, and the double mutants Y82F/S112W, Y82L/S112W, and Y82S/S112W (the last four mutants are Delta113-128) are presented. The rate constants observed differ by a factor of up to 10 among the respective adrenodoxin mutants for CYP11A1 but not for CYP11B1. According to their apparent rate constants for CYP11A1, the adrenodoxin mutants can be grouped into a slow (wild type, T54A, and T54S) and a fast group (all the other mutants). The adrenodoxin mutants forming the most stable complexes with CYP11A1 show the fastest rates of reduction and the highest rate constants for cholesterol to pregnenolone conversion. This strong correlation suggests that C-terminal truncation of adrenodoxin in combination with the introduction of a C-terminal tryptophan residue enables a modified protein-protein interaction rendering the system almost as effective as the bacterial putidaredoxin/CYP101 system. Such a variation of the adrenodoxin structure resulted in a mutant protein (S112W) showing a 100-fold increased efficiency in conversion of cholesterol to pregnenolone.

Eradication of intraperitoneal and distant tumor by adenovirus-mediated interferon-beta gene therapy is attributable to induction of systemic immunity

Malignant mesothelioma remains an incurable disease for which immune-modulatory therapies, such as exogenous cytokines, have shown some promise. One such cytokine, IFN-beta, has potent antiproliferative and immunostimulatory activity in vitro, but its in vivo use has been limited by toxicity. We thus conducted studies evaluating intracavitary delivery of a replication-deficient adenoviral (Ad) vector encoding for the murine IFN-beta gene (Ad.muIFN-beta) in mouse models of malignant mesothelioma. In contrast to multiple injections of recombinant protein, a single i.p. injection of Ad.muIFN-beta into animals with established tumors elicited remarkable antitumor activity leading to long-term survival in >90% of animals bearing either AB12 or AC29 i.p. mesotheliomas. A control adenovirus vector had minimal antitumor effect in vivo. Significant therapeutic effects were also seen in animals treated with large tumor burdens. Importantly, treatment of i.p. tumor also led to reduction of growth in tumors established at a distant site (flank). A number of experiments suggested that these effects were attributable to an acquired CD8(+) T-cell-mediated response including: (a) the induction of long-lasting antitumor immunity; (b) loss of efficacy of Ad.muIFN-beta in tumor-bearing, immune-deficient (SCID, SCID/beige) mice; (c) detection of high levels of specific antitumor cytolytic activity from unstimulated splenocytes harvested from Ad.muIFN-beta-treated animals that was abolished by CD8(+) T-cell depletion; and (d) abrogation of antitumor effects of Ad.muIFN-beta in tumor-bearing CD8(+) T-cell-depleted animals. These data show that intracavitary IFN-beta gene therapy using an adenoviral vector provides strong CD8(+) T-cell-mediated antitumor effects in murine models of mesothelioma and suggest that this may be a promising strategy for the treatment of localized tumors such as mesothelioma or ovarian cancer in humans.

[The importance of hydrostatic valves in the treatment of adult chronic hydrocephalus]

BACKGROUND AND OBJECTIVE

Earlier designs of hydrocephalus valves, focusing on a reduction of the problem of overdrainage, were proved to be insufficiently. Since the middle of the 90's hydrostatic valve, constructions are available, which should solve this problem. The objective of the study was to evaluate, whether these gravitational shunts would indeed reduce the percentage of overdrainage in shunted patients.

METHODS

In 51 patients clinical evaluation and MRI was performed pre- and in regular intervals postoperatively. 21 received a Dual-Switch valve, 14 a programmable Codman Hakim plus Shuntassistent and 6 a combination of a conventional valve with Shuntassistent.

RESULTS

Over 90% of the patients had clear and persisting (over 24 months) clinical benefit from shunting. Only one suffered for some days after shunt implantation from headache in the upright position. No other clinical or imaging hints were given on an overdrainage. The ventricular size was unchanged in patients with a normal pressure hydrocephalus after shunting. In patients with occlusive hydrocephalus only a few showed a significant reduction of the ventricular wide.

CONCLUSION

Gravitational shunts seem to decrease the overdrainage linked to the treatment of chronic hydrocephalus in shunted patients, therefore its use should be standardised when treatment chronic hydrocephalus.

[Pressure-dependent outflow resistance in cerebrospinal fluid dynamics: evaluation a calculation model for diagnosis of normal pressure hydrocephalus in an animal experiment with H-Tx rats]

The internationally accepted methods of calculating cerebrospinal fluid dynamics proceed from the assumption of a pressure-independent resistance to CSF outflow. Our new model focusses on the pressure-dependency of this resistance. In it, we monitor the entire pressure course over time, p(t) during and after infusion. A comparison of the pressure rise, On(p), during infusion, and the decrease, Off(p), to the same pressure level, permits the creation of all the formulas for C(p) and R(p). The simultaneous measurement of resistance and compliance during a single intervention allows us to minimize patient exertion. In contrast to the classical methods, it is not necessary for the ICP to reach a plateau. Our mathematical model differs from the static examination model by describing a pressure-dependent slope of the function for the resistance. This has been demonstrated in a study using H-Tx rats. In this way, we are able to take the non-linearity of the CSF resorption into consideration.

Thermal sterilization of heat-sensitive products using high-temperature short-time sterilization

High-temperature short-time (HTST) sterilization with a continuous-flow sterilizer, developed for this study, was evaluated. The evaluation was performed with respect to (a) the chemical degradation of two heat-sensitive drugs in HTST range (140-160 degrees C) and (b) the microbiological effect of HTST sterilization. Degradation kinetics of two heat-sensitive drugs showed that a high peak temperature sterilization process resulted in less chemical degradation for the same microbiological effect than a low peak temperature process. Both drugs investigated could be sterilized with acceptable degradation at HTST conditions. For the evaluation of the microbiological effect, Bacillus stearothermophilus ATCC 7953 spores were used as indicator bacteria. Indicator spore kinetics (D(T), z value, k, and E(a)), were determined in the HTST range. A comparison between the Bigelow model (z value concept) and the Arrhenius model, used to describe the temperature coefficient of the microbial inactivation, demonstrated that the Bigelow model is more accurate in prediction of D(T) values in the HTST range. The temperature coefficient decreased with increasing temperature. The influence of Ca(2+) ions and pH value on the heat resistance of the indicator spores, which is known under typical sterilization conditions, did not change under HTST conditions.