Altered white matter integrity in adults with autism spectrum disorder and an IQ >100: a diffusion tensor imaging study

OBJECTIVE

White matter (WM) alterations have been reported in children and adults with autism spectrum disorder (ASD). In particular, impaired connectivity of limbic structures may be related to social deficits. Heterogeneous findings could be explained in terms of differences in sample characteristics and methodology. In this context, non-syndromic forms might differ substantially in WM structure from secondary ASD forms.

METHOD

In an attempt to recruit a homogeneous study sample, we included adults with high-functioning ASD and an IQ > 100 to decrease the influence of syndromic forms being often associated with cognitive deficits. Diffusion tensor imaging (DTI) was performed in 30 participants with ASD and 30 pairwise-matched controls. Fractional anisotropy (FA) and mean diffusivity (MD) as surrogate imaging markers for WM integrity were calculated.

RESULTS

We found a significant FA decrease in the ASD group in the genu and body of the corpus callosum (CC). Increased MD was detected in the subgenual anterior cingulate cortex (sACC).

CONCLUSION

The finding of decreased WM integrity in the genu of the CC is in line with earlier studies reporting a decreased number of interhemispheric fibers in the frontal lobe of ASD. Alterations in the sACC might be associated with 'Theory of mind' deficits.

[Pulmonary hypertension associated with left heart disease: recommendations of the Cologne Consensus Conference 2016]

The 2015 European Guidelines on Diagnosis and Treatment of Pulmonary Hypertension are also valid for Germany. While the guidelines contain detailed recommendations regarding pulmonary arterial hypertension (PAH), they contain only a relatively short paragraph on other, much more common forms of PH such as PH due to left heart disease. Despite the lack of data, targeted PAH treatments are increasingly being used for PH associated with left heart disease. This development is of concern because of limited ressources and the need to base treatments on scientific evidence. On the other hand, PH is a frequent problem that is highly relevant for morbidity and mortality in patients with left heart disease, representing an unmet need of targeted PH therapies. It that sense, the practical implementation of the European Guidelines in Germany requires the consideration of several specific issues and already existing novel data. This requires a detailed commentary to the guidelines, and in some aspects an update already appears necessary. In June 2016, a Consensus Conference organized by the PH working groups of the German Society of Cardiology (DGK), the German Society of Respiratory Medicine (DGP) and the German Society of Pediatric Cardiology (DGPK) was held in Cologne, Germany. This conference aimed to solve practical and controversial issues surrounding the implementation of the European Guidelines in Germany. To this end, several working groups were initiated, one of which was specifically dedicated to PH associated with left heart disease. This article summarizes the results and recommendations of this working group.

[High-functioning autism spectrum disorders in adulthood]

The prevalence of autism spectrum disorders in the general population is approximately 1 %. Some individuals with high-functioning autism graduate from regular schools without autism having been diagnosed and problems only occur when the demands for social competence increase. Then patients often present with secondary psychiatric symptoms, such as depression, anxiety or interpersonal problems. At this time, typical autistic features, such as social interaction deficits, restricted interests and stereotypic behavior can be camouflaged by high compensatory skills, particularly in highly intelligent patients. Therefore, missed or wrong diagnoses are frequent. Interviews, questionnaires and neuropsychological tests might be used to support the diagnosis. In cases where there is evidence for a secondary cause of autistic symptoms, somatic disorders should be excluded. Pharmacological treatment should be symptom-oriented. Individualized psychotherapeutic approaches are becoming increasingly more available; however, pragmatic solutions often need to be deployed.

Degradation of Omeprazole Induced by Enteric Polymer Solutions and Aqueous Dispersions: HPLC Investigations

Two reversed-phase high-performance liquid chromatography (RP-HPLC) methods were developed to investigate the degradation of the acid-labile proton-pump-inhibitor omeprazole in organic polymer solutions and aqueous dispersions of enteric coating polymers (Eudragit L-100, S-100, CAP, HP-55, HPMCAS-HF, -LF, and shellac). The overall goal of the study was to determine the influence of the polymer structure on the degradation of omeprazole, i.e., whether the acid structure of the enteric coating polymers caused an instability of the proton pump inhibitor. Moreover, it was investigated whether a difference in omeprazole degradation could be detected between organic polymer solutions and aqueous dispersions. pKa values of the polymers and pH values of the aqueous dispersions were determined to see whether there was a correlation with the extent of degradation of omeprazole induced by enteric polymers. As the polymers containing phthalate moieties are very susceptible to hydrolysis, the influence of free phthalic acid on omeprazole stability was investigated. Finally, the degradation kinetics of omeprazole in organic polymer solutions were determined. Omeprazole degradation is more pronounced in aqueous polymer dispersions than in organic polymer solutions. The influence of organic polymer solutions on the stability of omeprazole depends on the amount of acidic groups in the polymeric structure, whereas the influence of aqueous polymer dispersions depends on the pH value of the dispersion. The amount of free acids present in some polymers as by-products also cause a degradation of the proton pump inhibitor. Among all investigated polymers, shellac showed the least influence on the stability of omeprazole. The decomposition of omeprazole in organic polymer solutions followed first-order kinetics. The decrease of omeprazole peak area in organic polymer solutions was in the order Eudragit L-100> HPMCAS-HF>shellac.

Female pattern hair loss may be triggered by low oestrogen to androgen ratio

OBJECTIVE

In both sexes the androgenetic alopecia is known to be mediated by the conversion of circulating androgens into dihydrotestosterone within the hair follicle. However, there are a number of differences between male and female pattern baldness with estrogen known to be protective against hair loss in women. Since androgen levels in women with female pattern hair loss are mostly within the normal range, we decided to calculate the ratio of estrogens to androgens in order to find a putative trigger for their hair loss.

METHODS

We studied 20 premenopausal women with female pattern hair loss and 9 healthy women for serum levels of LH, FSH, estradiol, free and total testosterone, sex hormone binding globulin (SHBG) and dehydroepiandrosterone sulfate (DHEAS) on the first day of their menstrual cycle.

RESULTS

Although the absolute levels of androgens were normal in both groups, the ratio of estradiol to free testosterone and the ratio of estradiol to DHEAS were significantly lower in patients than in the control group.

CONCLUSIONS

We put up a hypothesis that in the presence of a genetic susceptibility, it is the estrogen to androgen ratio, as represented by the ratio of estradiol to free testosterone that might be responsible for triggering female pattern hair loss in women.

Natural and traumatic sports-related fatalities: a 10-year retrospective study

OBJECTIVE

To identify the most common causes of death during sports activity in the population of Hamburg, Germany, and to identify which groups of sportspeople are particularly in danger of dying during sports and in which types of sport most fatalities occur.

DESIGN AND SETTING

We performed a 10-year autopsy-based retrospective study of all 48,335 fatalities in Hamburg and the surrounding areas that were subjected to police investigations between 1997 and 2006 and screened for sports-related deaths. The main outcome measure was cause of death depending on form of sport, age and risk factors.

RESULTS

Most of the fatalities were male. In natural deaths, cardiac causes were the most frequent causes found, with running and football being the most frequent forms of sport in which death had occurred. In some of the cases, sports medical examinations had been performed before death, certifying eligibility for the respective activity. Traumatic deaths were found in all age groups, with younger age groups more likely to have traumatic than natural deaths, and as expected, occurred more commonly in "risky" outdoor activities.

CONCLUSIONS

Although exercise can have beneficial effects on health, fatalities related to sports activity occur. Cardiac disease is the main cause of sudden death from natural causes. In patients with pre-existing coronary heart disease, left ventricular hypertrophy constitutes a risk factor for exercise-related sudden death. Traumatic deaths often happen on holiday outside the person's country of dwelling, and are most commonly attributable to drowning and blunt trauma. Preparticipation medical screening cannot always prevent fatal incidents during sports activity. Postmortem macroscopic and histological examination can clarify the cause of death and legal issues.

Permanent increase in endothelin serum levels in vasovagal syncope

Of 40 normal volunteers tilted on two separate occasions, seven subjects had vasovagal syncope only during one upright tilt, but showed increased endothelin plasma levels in the supine position and during head-up tilt on both occasions, independent of vasovagal syncope, compared to control subjects.

Quantification of omeprazole degradation by enteric coating polymers: an UV-VIS spectroscopy study

The aim of this study was to investigate the degradation of the acid-labile proton-pump-inhibitor omeprazole in organic polymer solutions and aqueous dispersions of enteric coating polymers by UV spectroscopy. Furthermore, data were compared with those obtained in a previous HPLC study. For comparative purposes the cationic Eudragit RS 100 and the monomeric acid acetic acid were included in this study. The discolorations of degraded omeprazole solutions were analysed by VIS spectroscopy. UV-VIS spectra were recorded after preparation of the solutions and after 180 min of storage. The change of absorption was calculated as the difference of the absorption values at 305 nm. Degradation of omeprazole depends on the amount of acidic groups in the polymer structure. This decomposition manifests itself in a shifting of the absorption maximum to lower wavelengths and a decrease of absorption intensity. UV-VIS spectroscopy was used to determine the extent of degradation induced by enteric polymers. A good correlation of these results with previous HPLC data was found when excluding UV absorbing polymers. Nevertheless, values obtained by UV-VIS spectroscopy were always lower than those obtained by HPLC. For evaluation of the discoloration of degraded omeprazole solutions, VIS spectroscopy is a simple and fast method.

Fröhlich mass in GaAs-based structures

The Fröhlich interaction is one of the main electron-phonon intrinsic interactions in polar materials originating from the coupling of one itinerant electron with the macroscopic electric field generated by any longitudinal optical (LO) phonon. Infrared magnetoabsorption measurements of doped GaAs quantum well structures have been carried out in order to test the concept of Fröhlich interaction and polaron mass in such systems. These new experimental results lead one to question the validity of this concept in a real system.

A clinical trial of adjunctive oestrogen treatment in women with schizophrenia

A double-blind, 28-day, placebo-controlled study was conducted with three groups of women of child-bearing age (N = 12 in each group) who received standardised antipsychotic medication plus a) 50 microg transdermal estradiol or b) 100 microg transdermal estradiol or c) transdermal placebo. Preliminary analyses show that women receiving 100 microg of estradiol made greater improvements in the symptoms of schizophrenia than either the 50 microg estradiol or placebo groups. The addition of 100 microg adjunctive transdermal oestrogen significantly enhanced treatment responsivity of acute, severe psychotic symptoms in women with schizophrenia. The positive impact of oestrogen treatment on psychotic symptoms via a multiplicity of possible actions (see accompanying articles in this issue) may prove clinically useful in the overall treatment of women with schizophrenia.

Influence of a radiofrequency electromagnetic field on cardiovascular and hormonal parameters of the autonomic nervous system in healthy individuals

The potential health risks of radiofrequency electromagnetic fields (EMFs) emitted by mobile phones are of considerable public interest. The present study investigated the hypothesis, based on the results of our previous study, that exposure to EMFs can increase sympathetic vasoconstrictor activity. Forty healthy young males and females underwent a single-blind, placebo-controlled protocol once on each of two different days. Each investigation included successive periods of placebo and EMF exposure, given in a randomized order. The exposure was implemented by a GSM-like signal (900 MHz, pulsed with 217 Hz, 2 W) using a mobile phone mounted on the right-hand side of the head in a typical telephoning position. Each period of placebo exposure and of EMF exposure consisted of 20 min of supine rest, 10 min of 70 degrees upright tilt on a tilt table, and another 20 min of supine rest. Blood pressure, heart rate and cutaneous capillary perfusion were measured continuously. In addition, serum levels of norepinephrine, epinephrine, cortisol and endothelin were analyzed in venous blood samples taken every 10 min. Similar to the previous study, systolic and diastolic blood pressure each showed slow, continuous, statistically significant increases of about 5 mmHg during the course of the protocol. All other parameters either decreased in parallel or remained constant. However, analysis of variance showed that the changes in blood pressure and in all other parameters were independent of the EMF exposure. These findings do not support the assumption of a nonthermal influence of EMFs emitted by mobile phones on the cardiovascular autonomic nervous system in healthy humans.

Principles of rat subcortical forebrain organization: a study using histological techniques and multiple fluorescence labeling

In the present study, we introduce new views on neuro- and chemoarchitectonics of the rat forebrain subcortex deduced from traditional and current concepts of anatomical organization and from our own results. It is based on double and triple immunofluorescence of markers for transmitter-related enzymes, calcium-binding proteins, receptor proteins, myelin basic protein (MBP) and neuropeptides, and on histological cell/myelin stains. The main findings can be summarized as follows: (i) the dorsal striatum of rat and other myomorph rodents reveals a small caudate equivalent homotopic to the caudate nucleus (C) of other mammals, and a large putamen (Pu). (ii) Shell and core can be distinguished also in the 'rostral pole' of nucleus accumbens (ACC) with the calretinin/calbindin and neuropeptide Y (NPY) immunostaining. The shell reveals characteristics of a genuine striatal but not of an extended amygdala (EA) subunit. (iii) EA and lateral septum show striking similarities in structure and fiber connections and may therefore represent a separate parastriatal complex. (iv) The meandering dense layer (DL) of olfactory tubercle (OT) forms longitudinal gyrus- and sulcus-like structures converging in its rostral pole. (v) The core regions of the islands of Calleja that border the ventral pallidum (VP) sharing some of its features are invaded by myelinated fibers of the medial forebrain bundle (MFB). The island of Calleja magna is also apposed to an inconspicuous, slender dorsal appendage of VP. (vi) The VP is composed of a large dorsal reticulated part traversed by the myelinated GABAergic parvalbumin-immunoreactive axons of the MFB and a slender ventral non-reticulate part close to the islands of Calleja. (vii) Considering their close association to the limbic system, ventral striatum (VS) and VP may represent the oldest part of basal ganglia, whereas dorsal striatopallidal subunits were progressively developed in parallel to the growing neocortical influence on motor behavior.

Estrogen - a potential treatment for schizophrenia

Estrogen has been shown in animal studies to modulate both the dopamine and serotonin neurotransmitter systems - the main neurotransmitters implicated in the pathogenesis of schizophrenia. A double blind, 28 day, placebo-controlled study was conducted with three groups of women of child-bearing age (N=12 in each group) who received standardized antipsychotic medication plus 50mcg transdermal estradiol or 100mcg transdermal estradiol or transdermal placebo. Analyses show that women receiving 100mcg of estradiol made greater improvements in the symptoms of schizophrenia than both the 50mcg estradiol and placebo groups. Women receiving 50mcg estradiol had more improvement in their symptoms compared with the placebo group. The 100mcg estradiol group had significantly lower mean lutenizing hormone (LH) and higher mean prolactin levels across the study period compared with both the 50mcg and placebo groups. The addition of 100mcg adjunctive transdermal estrogen significantly enhanced the treatment of acute, severe psychotic symptoms in women with schizophrenia. The differential response of adding 50mcg versus 100mcg estradiol on the types of symptom affected may be related to the estrogen effect on LH and prolactin. The positive impact of estrogen treatment on psychotic symptoms by a direct effect on dopamine and serotonin systems or via an indirect prolactin-mediated effect may be very useful in the overall treatment of women with schizophrenia.

Magneto infrared absorption in high electron density GaAs quantum wells

Magneto infrared absorption measurements have been performed in a highly doped GaAs quantum well which has been lifted off and bonded to a silicon substrate, in order to study the resonant polaron interaction. It is found that the pinning of the cyclotron energy occurs at an energy close to that of the transverse optical phonon of GaAs. This unexpected result is explained by a model taking into account the full dielectric constant of the quantum well.

Self-starting mode locking of a Nd:glass fiber laser by use of the third-order nonlinearity of low-temperature-grown GaAs

We present a diode-pumped Nd:glass fiber laser, emitting at 1060 nm, that is passively mode locked by fast nonlinear loss in low-temperature-grown GaAs (LT-GaAs). This new mode-locking mechanism is based on intensity-dependent defocusing in LT-GaAs that occurs after nonresonant generation of free carriers by two-photon absorption. Mode locking is self-starting and produces pulses as short as 4.1 ps.

Cardiac uptake of [123I]MIBG separates Parkinson's disease from multiple system atrophy

OBJECTIVE

To improve the differential diagnosis between patients with multiple system atrophy (MSA) and idiopathic PD (IPD) with autonomic failure.

BACKGROUND

Some patients diagnosed with IPD are discovered to have alternative diseases such as MSA, despite the application of stringent diagnostic criteria. This differentiation is particularly difficult if patients with IPD also show symptoms of autonomic failure. In IPD, autonomic failure is caused by damage of the postganglionic part of the autonomic nervous system, whereas in MSA, degeneration of preganglionic and central autonomic neurons is revealed histopathologically.

METHODS

Scintigraphy with [123I]metaiodobenzylguanidine (MIBG) enables the quantification of postganglionic sympathetic cardiac innervation. Fifteen patients with IPD and 5 patients with MSA underwent standard autonomic function tests and scintigraphy with MIBG.

RESULTS

In all patients, cardiovascular testing showed evidence of autonomic failure of varying severity. In all patients with IPD, the heart-mediastinum (H/M) ratio of MIBG uptake was pathologically impaired, independent of duration and severity of autonomic and parkinsonian symptoms. All patients with MSA had a regular H/M ratio. Each patient could be assigned to the correct diagnostic group based on the results of the MIBG scintigraphy, even if the duration of the disease was only 2 years or less.

CONCLUSIONS

This population assessment of the heart-mediastinum ratio of [123I]metaiodobenzylguanidine uptake showed a high sensitivity for the detection of autonomic involvement in patients with idiopathic IPD and also a high specificity for the discrimination between idiopathic PD and MSA.

Quantitative sudomotor axon reflex test (QSART): a new approach for testing distal sites

The quantitative sudomotor axon reflex test (QSART) is a useful tool in the evaluation of C-fiber function. Because many neuropathies show a length-dependent loss of nerve function, a new capsule was designed for distal performance of the QSART, allowing measurements on fingers and toes. We investigated 20 healthy volunteers and 15 patients with insulin-dependent diabetes mellitus and normal sensory nerve conduction studies. A QSART was performed on the forearm and on the thumb. The groups showed no differences in the QSARTs on the forearm, but the sweat volume on the thumb was significantly lower in patients. Calculation of the forearm/finger ratio reduced the interindividual variation and showed the highest sensitivity for detecting C-fiber dysfunction in the patient group. We conclude that the distal measuring device and the forearm/finger ratio are more sensitive tools for the early detection of distal-onset neuropathies than are the commonly used proximal testing sites.

The Qo-site inhibitor DBMIB favours the proximal position of the chloroplast Rieske protein and induces a pK-shift of the redox-linked proton

The interaction of the inhibitor 2,5-dibromo-3-methyl-6-isopropylbenzoquinone (DBMIB) with the Rieske protein of the chloroplast b6f complex has been studied by EPR. All three redox states of DBMIB were found to interact with the iron-sulphur cluster. The presence of the oxidised form of DBMIB altered the equilibrium distribution of the Rieske protein's conformational substates, strongly favouring the proximal position close to heme bL. In addition to this conformational effect, DBMIB shifted the pK-value of the redox-linked proton involved in the iron-sulphur cluster's redox transition by about 1.5 pH units towards more acidic values. The implications of these results with respect to the interaction of the native quinone substrate and the Rieske cluster in cytochrome bc complexes are discussed.

Comparison of the rat dorsal and ventral striatopallidal system. A study using the GABA(A)-receptor alpha1-subunit and parvalbumin immunolabeling

The ventral striatum is more closely related to limbic brain regions than the dorsal striatum in spite of the remarkable similarities in the structural organization between these two brain regions. The present study is focused on the comparison of ventral striatopallidal territories and the dorsal striatopallidal system regarding the GABA(A)-receptor alpha1-subunit and parvalbumin immunoreactivity, as these markers showed specific distribution patterns and coexpression sites in the more intensely studied dorsal regions. Our investigations revealed that: (1) Parvalbumin single-labeled cells and a moderate number of neurons single-labeled with the GABA(A)-receptor alpha1-subunit exist not only in the dorsal but also in the ventral striatum, including the striatal cell bridges. In addition, morphologically similar neurons positive for the alpha1-subunit were also found in the corpus callosum and anterior commissure. (2) A small number of double-labeled neurons was seen not only in dorsal but also in ventral striatal regions. Such cells were mainly located near the border with the globus pallidus and ventral pallidum. They are likely to represent a further type of striatal neuron. (3) The vast majority of neurons in the entopeduncular nucleus, the homologue of the primate internal globus pallidus segment, coexpressed alpha1-subunit and parvalbumin immunoreactivity, as reported previously for the other pallidal compartments. (4) The islands of Calleja adjoining the ventral pallidal extensions in the olfactory tubercle exhibited a strong alpha1-subunit immunoreactivity in the neuropil as well as somata single- or double-labeled for both markers. Our findings indicate that the dorsal and ventral striatopallidal compartments are similarly organized in general with respect to the occurrence and distribution of single- and double-labeled parvalbumin-immunoreactive and GABA(A)-receptor alpha1-subunit-immunoreactive neurons.

Axonal expression sites of tyrosine hydroxylase, calretinin- and calbindin-immunoreactivity in striato-pallidal and septal nuclei of the rat brain: a double-immunolabelling study

Besides the dopaminergic afferent projection system, calbindin (CALB)- and calretinin (CR)-immunoreactive fibres of intrinsic and extrinsic origin represent the most abundant axonal categories in the rat striatal and lateral septal areas. The question arises whether or not they may represent separate populations, or whether they form subgroups which co-express more than one of these antigens. Therefore, the present study is focused on the distribution patterns of the axons single-immunolabelled by the catecholaminergic marker tyrosine hydroxylase (TH), and on TH-immunoreactive axons displaying also CR- and/or CALB-immunoreactivity in double-immunostained sections. Striking differences were found between the patch and matrix compartments of the caudate-putamen (CP). Whereas the vast majority of TH-immunoreactive fibres in the patches and a patch-associated subcallosal layer co-expressed CR but not CALB, fibres mono-labelled by the TH-immunoreactivity were predominant in the matrix. The matrix-like regions of the core of nucleus accumbens (CACC), fundus striati (FS), the striatal cell bridges (CB) and the striatal part of olfactory tubercle (OTU) coincided in this respect with the matrix in CP. The absence of CR-immunoreactivity was also characteristic of the TH-immunoreactive fibres in the patch-like areas of the accumbal core, although a high number of separate CR-immunoreactive axons were present. In the shell of nucleus accumbens (SACC) which receives a rich catecholaminergic innervation, fibres co-expressing either one of the calcium-binding proteins were absent. The islands of Calleja (CJI) displaying a strongly TH-immunoreactive centre and a periphery of lower staining intensity, showed only a low number of TH-immunoreactive fibres co-expressing CR or CALB. The broad shell-like band of TH-immunoreactive axons between medial and lateral part of the septum was single-stained with the TH-immunoreactivity. In contrast, the TH-positive fibres forming basket-like arrangements around some neurons in the dorsal lateral septal nucleus co-expressed also CR, but not CALB. The results are discussed in view of the recent concepts of basal forebrain organization and the cytochemical characteristics of mesencephalic dopaminergic nuclei giving rise to the vast majority of the striatal and septal TH-immunoreactive fibre supply, in order to correlate the known projection patterns with the content of calcium-binding proteins in TH-immunolabelled fibres and presumed cells of origin. The TH-immunoreactive fibres in the striatal patches displaying CR- but not CALB-immunoreactivity may originate mainly from neurons in the ventral tier of pars compacta (SNC) and from the pars reticulata of substantia nigra (SNR) which show identical cytochemical properties. Axons in the matrix of CP and the accumbal core as well as in the islands of Calleja single-labelled by the TH-immunoreactivity or additionally containing CALB and CR may originate from neurons in the dorsal tier of mesencephalic nuclei like SN, pars compacta and ventral tegmental area. CR-containing TH-immunoreactive basket-like axon terminations in the dorsal lateral septal nucleus are likely to originate either from mesencephalic nuclei or from the supramammillary region.

A simple and inexpensive pinch meter to detect subclinical weakness among leprosy patients

This paper describes the use of a neonatal sphygmomanometer cuff as a simple, inexpensive pinch meter. Normal values for key pinch, pulp pinch and side pinch in the dominant hand of healthy Nepali people are provided. The pinch meter was also used to test pinch strength in hands affected by leprosy and normal hands. Some patients with leprosy who have no objective weakness on voluntary muscle testing (VMT) have less pinch strength than people without leprosy. The pinch meter is a useful tool for the early detection of motor function loss.

[Quality of life and coping with illness in patients with acute myeloid leukemia]

Advances in chemotherapy significantly prolong survival of patients with acute myeloid leukemia (AML) and may cure a significant percentage of patients. Therefore, the assessment of quality of life (QL) of patients undergoing chemotherapy is of growing interest. This study was designed to evaluate QL in patients with AML treated according to the protocol of the German AML-Cooperative Group (Münster, FRG). Based on conceptual, methodological and practical criteria, the EORTC-QLQ C 30 questionnaire was used. In addition, patients' coping strategies were assessed by the FQCI. Patients' individual perception of their disease and therapy was evaluated by a semi-structured interview. Currently, 61 patients are enrolled in the protocol. For those patients having completed the course of inpatient treatment, individual assessment of Global Health Status and Subjective QL improves significantly. The content analysis of the interviews shows to what extent aspects of the inpatient setting influence patients' QL. Although only a minority of patients with AML remain in continuous complete remission, the evaluation of QL in patients undergoing treatment shows that subjective benefit outweighs the effects of antileukemic therapy.

The effect of intracellular pH on cytosolic Ca2+ in HT29 cells

The influence of intracellular pH (pHi) on intracellular Ca2+ activity ([Ca2+]i) in HT29 cells was examined microspectrofluorometrically. pHi was changed by replacing phosphate buffer by the diffusible buffers CO2/HCO3- or NH3/NH4+ (pH 7.4). CO2/HCO3- buffers at 2,5 or 10% acidified pHi by 0.1, 0.32 and 0.38 pH units, respectively, and increased [Ca2+]i by 8-15 nmol/l. This effect was independent of the extracellular Ca2+ activity and the filling state of thapsigargin-sensitive Ca2+ stores. Removing the CO2/HCO3- buffer alkalinized pHi by 0.14 (2%), 0.27 (5%), and 0.38 (10%) units and enhanced [Ca2+]i to a peak value of 20, 65, and 143 nmol/l, respectively. Experiments carried out with Ca2+-free solution and with thapsigargin showed that the [Ca2+]i transient was due to release from intracellular pools and stimulated Ca2+ entry. NH3/NH4+ (20 mmol/l) induced a transient intracellular alkalinization by 0.6 pHunits and increased [Ca2+]i to a peak (Delta [Ca2+]i = 164 nmol/l). The peak [Ca2+]i increase was not influenced by removal of external Ca2+, but the decline to basal [Ca2+]i was faster. Neither the phospholipase C inhibitor U73122 nor the inositol 1,4,5-trisphosphate (InsP3) antagonist theophylline had any influence on the NH3/NH4+-stimulated [Ca2+]i increase, whereas carbachol-induced [Ca2+]i transients were reduced by more than 80% and 30%, respectively. InsP3 measurements showed no change of InsP3 during exposure to NH3/NH4+, whereas carbachol enhanced the InsP3 concentration, and this effect was abolished by U73122. The pHi influence on "capacitative" Ca2+ influx was also examined. An acid pHi attenuated, and an alkaline pHi enhanced, carbachol- and thapsigargin-induced [Ca2+]i influx. We conclude that: (1) an alkaline pHi releases Ca2+ from InsP3-dependent intracellular stores; (2) the store release is InsP3 independent and occurs via an as yet unknown mechanism; (3) the store release stimulates capacitative Ca2+ influx; (4) the capacitative Ca2+ influx activated by InsP3 agonists is decreased by acidic and enhanced by alkaline pHi. The effects of pHi on [Ca2+]i should be of relevance under many physiological conditions.

Light-induced charge separation between plastocyanin and the iron-sulfur clusters FA and FB in the complex of plastocyanin and photosystem I

The light-induced electron transfer in a crosslinked complex between plastocyanin and photosystem I from spinach was studied by EPR at low temperature. Electron donation from reduced plastocyanin to P700+ was observed under illumination above a temperature of about 160 K, resulting in a second charge separation and an electron transfer from rereduced P700 to the terminal electron acceptors FA/FB. The charge-separated state Pc oxP700+ [FA/FB](2-) was found to be stable at 15 K. Implications of these results for the kinetic constants of the donation reaction and the backtransfer of electrons from reduced acceptors as well as for the structural models of the terminal acceptors are discussed.

The role of adjuvant radiation and multiple resection within the surgical management of brain metastases

Cerebral metastases occur in 25% to 35% of all cancer patients. The advances in systemic and topical treatment as well as the rising incidence of lung cancer and melanomas are associated with an increasing incidence of cerebral metastases. More than 20,000 patients die every year in the Federal Republic of Germany of this disease. This retrospective analysis covers 145 patients who underwent surgery. Survival analysis of different subgroups was performed. The patients were grouped according to their clinical status and the different therapeutical procedures which were performed. Group A, consisting of all those patients where a gross total resection could be performed and where no systemic disease was apparent at the time of craniotomy showed the best results, having the highest portion of long term survivors. Group B, consisting of those patients who underwent a subtotal resection and who had no systemic disease at the time of craniotomy, had a worse outcome. Group C patients (gross total resection and systemic disease) as well as Group D (subtotal resection and systemic disease) presented the poorest results with respect to survival. A benefit was mediated by adjuvant radiation as well as multiple resections. Surgery is the method of choice for the treatment of a single metastasis. Advances in microsurgery nowadays sometimes justify even the removal of multiple metastases, depending on their location, on the general condition of the patient and on prognosis.

EPR, electron spin echo envelope modulation, and electron nuclear double resonance studies of the 2Fe2S centers of the 2-halobenzoate 1,2-dioxygenase from Burkholderia (Pseudomonas) cepacia 2CBS

The 2-halobenzoate 1,2-dioxygenase from Burkholderia (Pseudomonas) cepacia 2CBS (Fetzner, S., Müller, R., and Lingens, F. (1992) J. Bacteriol. 174, 279-290) contains both a ferredoxin-type and a Rieske-type 2Fe2S center. These two significantly different 2Fe2S clusters were characterized with respect to their EPR spectra, electrochemical properties (Rieske-type cluster with gz = 2.025, gy = 1.91, gx = 1.79, gav = 1.91, Em = -125 +/- 10 mV; ferredoxin-type center with gz = 2.05, gy = 1.96, gx = 1.89, gav = 1.97, Em = -200 +/- 10 mV) and pH dependence thereof. X band electron spin echo envelope modulation and electron nuclear double resonance spectroscopy was applied to study the interaction of the Rieske-type center of the 2-halobenzoate 1,2-dioxygenase with 14N and 1H nuclei in the vicinity of the 2Fe2S cluster. The results are compared to those obtained on the Rieske protein of the cytochrome b6f complex (Em = +320 mV) and the water-soluble ferredoxin (Em = -430 mV) of spinach chloroplasts, as typical representatives of the gav = 1.91 and gav = 1.96 class of 2Fe2S centers. Properties common to all Rieske-type clusters and those restricted to the respective centers in bacterial oxygenases are discussed.

The 2Fe2S centres of the 2-oxo-1,2-dihydroquinoline 8-monooxygenase from Pseudomonas putida 86 studied by EPR spectroscopy

The 2-oxo-1,2-dihydroquinoline 8-monooxygenase from Pseudomonas putida 86 comprises two components with four redox active sites necessary for activity. We present an EPR characterization of the iron-sulfur centres in the purified reductase and oxygenase component of this novel enzyme system. The oxygenase component was identified as a Rieske [2Fe2S] protein on the basis of its characteristic EPR spectrum with gz,y,x = 2.01, 1.91, 1.76 and gav = 1.893. The reductase component, an iron-sulfur flavoprotein, contained a [2Fe2S] cluster with gz,y,x = 2.03, 1.94, 1.89 and the average g-value (gav) of 1.953, typical of a ferredoxin-type centre. In redox titrations at pH 7, the midpoint potentials were determined to be -180 mV +/- 30 mV and -100 mV +/- 10 mV for the reductase and oxygenase component, respectively. A detailed comparison to other multicomponent enzyme systems is presented pointing out the EPR and redox properties of the FeS centres involved.

A new species-group of Ottistira Pascoe from New Guinea (Coleoptera : Curculionidae : Entiminae : Ottistirini)

Nine new species of Ottistira Pascoe (O. arfakensis Riedel, O. ascendens Riedel, O. dani Riedel, O. longispina Riedel, O. obrienorum Riedel, O. paniaiensis Riedel, O. robusta Riedel, O. telefominensis Riedel, O. tumidirostris Riedel) are described from the highlands of New Guinea. They form a monophyletic group and can be diagnosed by their possession of both lateral humeral flanges and median elytral spines. Male genitalia offer good characters for separation of species, especially when the endophallus is everted. A key to the species is included. Habitus photographs and illustrations of male and female genitalia for all species are provided.

[Follow-up studies of patients with negative TRH test and normal thyroid hormone levels]

The aim of the study was to assess the clinical significance of the association of a negative TRH-test with normal thyroid hormone levels. Therefore, we repeated the investigation in 63 patients one year after the first examination. In 6 patients (10%) hyperthyroidism had developed. Euthyroid autonomy was diagnosed in 11 patients (17%). A prolonged normalisation period of the pituitary-thyroid regulation after having discontinued the thyroid hormone drugs was found in 7 patients (11%). In 40% of the patients the TRH-test remained negative and in 22% of the patients the TSH-response became positive without any known reason. The findings show that a negative TRH-test and normal thyroid hormone levels do not necessarily imply subclinical hyperthyroidism.

The Rieske FeS center from the gram-positive bacterium PS3 and its interaction with the menaquinone pool studied by EPR

The Rieske 2Fe2S center from Bacillus PS3, a Gram-positive thermophilic eubacterium, has been studied by EPR spectroscopy. Its redox midpoint potential at pH 7.0 was determined to be +165 +/- 10 mV and was found to decrease with an apparent slope of -80 mV/pH unit above pH 7.9. The Qo-site inhibitor stigmatellin induced spectral changes analogous to those reported for Rieske centers from mitochondria and chloroplasts. The redox midpoint potential of the PS3 Rieske cluster was not affected by stigmatellin. The orientation of the g tensor was similar to other Rieske centers (gz and gy are oriented parallel, gx is oriented perpendicular to the membrane plane). The shape of the EPR spectrum of the Rieske cluster from PS3 changed as a function of the redox state of the menaquinone (MK) pool. This permitted the redox midpoint potential of the MK pool to be determined in the membrane. Values of -60 +/- 20 mV at pH 7.0 and of -130 +/- 20 mV at pH 8.0 were obtained. The results are compared with already published data from other Rieske centers. It is proposed that all Rieske centers that function in electron transport chains using MK as pool quinone show common features that distinguish them from Rieske centers operating in ubiquinone- or plastoquinone-based electron transfer chains.

Effect of BN 52256 and other mediator antagonists on ouabain-induced cardiac arrhythmia in a model of anaphylaxis in guinea-pigs

Different mediators released by anaphylaxis seem to be involved in different pathophysiological conditions, including cardiac arrhythmia. Histamine, 5-HT and platelet-activating factor (PAF) could participate in the enhanced arrhythmogenicity during anaphylaxis in guinea-pigs. The threshold dose of ouabain-induced arrhythmia is decreased in actively sensitized guinea-pigs by i.p. administration of ovalbumin. The purpose of the present paper was to investigate the effect of different mediator antagonists. Antagonists of PAF (WEB 2170), histamine (clemastine) and 5-HT (cyproheptadine) in doses of 5.0 mg/kg, 5.0 mg/kg and 0.5 mg/kg, respectively, can increase the threshold dose of ouabain-induced arrhythmias signalling an antiarrhythmic effect. A combination of WEB 2170 and clemastine, each of them in inactive doses (2.0 mg/kg and 1.0 mg/kg, respectively) showed a statistically significant antiarrhythmic effect. A combination of the same dose of WEB 2170 and cyproheptadine (0.1 mg/kg) under the same conditions induced an antiarrhythmic effect, too. BN 52256 is a new antiallergic drug synthesized on the basis of a novel concept of combining inhibitory activity against various inflammatory mediators in one molecule. BN 52256 in doses of 20-80 micrograms/kg exhibited a statistically significant antiarrhythmic effect. BN 52256 needed a 12.5-125 fold lower dose to induce the same antiarrhythmic effect compared to the antagonists of PAF, histamine or 5-HT investigated in this study. Depending on the pathophysiological conditions, different mediators seem to be involved in the occurrence of cardiac arrhythmia. A complex inhibition of these mediators could induce a more specific influence on such kinds of cardiac arrhythmias.

Effect of BN 52256 and other mediator antagonists on ouabain-induced ventricular fibrillation in sensitized guinea-pigs and on ischemia-induced fibrillation in rats

The threshold dose of ouabain necessary to induce ventricular fibrillation is decreased in sensitized guinea-pigs signalizing an enhanced arrhythmogenicity. Esculetine or WEB 2170 antagonists of histamine and PAF, respectively and especially a combination of both can increase the threshold dose of ouabain-induced fibrillation demonstrating an antiarrhythmic effect. BN 52256 a substance with multi-antagonistic properties shows antiarrhythmic effect in this method, too. WEB 2170 and BN 52256 decrease the incidence of ventricular fibrillation after coronary ligation in rats.

[Three-dimensional reconstructions in neuroanatomy]

Computer-aided 3D reconstructions of neurofunctional systems and structures are generated as a reference for neuroimaging (CT, MRI, PET). The clinical application of these 3D reconstructions requires a coordinate system and conditions resembling the intravital neuroanatomy as far as possible. In this paper the neuroanatomical Reference System (NeuRef) of the Department of Neuroanatomy of Hannover Medical School is presented. This consists of methods to record brain structures from serial sections with minimal error (less than 1 mm) and to display 3D brain models derived from such a data base. In addition, NeuRef is able to generate sections through, for instance, the visual and pyramidal system and to transfer these data onto a corresponding CT image. Therefore, this method can serve as a diagnostic aid in neuroradiology, in operation planning, and radiotherapy. It can also be used in PACS.

Chloroplast Rieske Center. EPR study on its spectral characteristics, relaxation and orientation properties

The spectral parameters, the orientation of the g tensor in two-dimensionally ordered multilayers and the relaxation properties of the Rieske center in purified cytochrome b6f complex from spinach were studied by EPR spectroscopy. A trough at g = 1.76 - 1.74 was unambiguously identified as the gx signal on the basis of the sensitivity of its field position to inhibitors and oxidized plastoquinone. In contrast to previous reports, the orientation of the chloroplast Rieske center was found to be identical to that of its cytochrome bc1 counterpart, provided that non-saturating EPR conditions were applied. Upon onset of microwave saturation, however, the orientation with respect to the ordered multilayers where the gy signal (g = 1.9) was maximal, changed drastically and was then similar to the orientation reported previously (Prince R. C., Crowder, M. S., and Bearden, A. J. (1980) Biochim. Biophys. Acta 592, 323-337). The unusually anisotropic saturation behavior of the EPR spectrum was characterized in detail, whereby hitherto controversial results on the spectral parameters of the chloroplast Rieske center could be rationalized. The observed phenomena are discussed on the basis of three tentative models which are able to qualitatively explain the effects.

Quantitative changes during the postnatal maturation of the human visual cortex

Postnatal development of the human visual cortex is characterized by an overshooting growth pattern of its volume with a maximum at 8 postnatal months and by loss of a substantial proportion of its neurons. The highest rate of reduction in neuronal numbers is observed in layers II-IVa, with other layers showing a more gradual postnatal decrease.

Morphometric study on the postnatal growth of the hippocampus in Australian Aborigines and Caucasians

In an autopsy study on Australian Aborigines (29 males, 27 females) and Caucasians (57 males, 37 females) the postnatal growth of the hippocampus was studied and described by mathematical growth functions. For male adults no significant difference in hippocampal volume was found. In contrast, hippocampal volume was significantly smaller for Aboriginal females compared to Caucasian females. Growth analysis showed slower growth rates and later half-value times for Aborigines compared to Caucasians. These results are discussed in relation to secular changes of growth parameters of the human brain during the last century, the socioeconomic and health status of Aborigines, and sexual differences in development and plasticity of the hippocampus.

The trapidil derivative AR 12456 protects against serum hyperlipidemia in guinea pigs

The administration of the trapidil derivative AR 12465 (5 mg/kg body weight) intraperitoneally to hypercholesterolemic guinea pigs caused a stronger reduction in serum total cholesterol (TC) than trapidil (20 mg/kg, i.p.) or a vehicle injection (saline with 5% ethanol i.p.). The stronger reduction of TC is caused by a lower level in the sum of all beta-migrating lipoproteins and an enhanced level of high-density lipoprotein. The levels of free and esterified cholesterol were not changed in kidney and left cardiac ventricle, but significantly enhanced (P less than 0.05) in the liver of all groups fed a cholesterol-rich diet. The elevation in liver cholesterol was higher in the group treated with AR 12456 than in the group treated with trapidil or with vehicle. The treatment with AR 12456 diminished the ratio TXB2/6-keto-PGF1 alpha for the capacity of aorta to form these prostanoids. In conclusion, our data show that AR 12456 has a strong antilipidemic action in guinea pigs fed a cholesterol-rich diet.

Antagonists of PAF and histamine inhibit ouabain-induced cardiac arrhythmias in sensitized guinea-pigs

Platelet-activating factor (PAF) seems to be involved in different pathophysiological conditions, including cardiac arrhythmia. The arrhythmogenic potency of PAF has been shown experimentally by different methods. PAF antagonists inhibit the PAF-induced enhanced arrhythmogenicity. The present paper demonstrates that the threshold dose of ouabain-induced arrhythmia is decreased in sensitized guinea-pigs. Antagonists of PAF (BN 52021, WEB 2086, WEB 2170) and histamine antagonist clemastine can increase the threshold dose of ouabain-induced arrhythmia. A combination of WEB 2170 and clemastine, each of the drug is a low dose which is without effect when applying one of them only, shows a highly significant antiarrhythmic effect in this method. The threshold dose of ouabain necessary to induce ventricular flutter was increased from 89 micrograms/kg to 129 micrograms/kg and the threshold dose of ventricular fibrillation was enhanced from 101 micrograms/kg to 137 micrograms/kg. In dependence on the pathophysiological conditions, different mediators seem to be involved in the occurrence of cardiac arrhythmia. Therapeutically influencing these mediators could be a real chance to optimise the treatment of such kind of cardiac arrhythmias.

The effect of PAF in the cochlea of guinea pigs

The influence of 10(-10) and 10(-9) M PAF/animal given into the jugular vein over 30 sec on inner ear potentials, i.e. endolymphatic potential (EP), summating potential (SP) and cochlear microphonics (CM) was investigated. The EP showed the most pronounced changes. When infusing a specific PAF receptor antagonist, ginkgolide B, or the TXA2 receptor antagonist, sulotraban, before the the infusion of PAF, the changes in cochlear potentials could be completely prevented. A second TXA2 receptor antagonist, daltroban, did not effectively prevent PAF actions. It is hypothesized that these PAF effects are due to an interference with ion transport in the non-sensory structures of the inner ear.

Morphometric study on the postnatal growth of the cerebellum of Australian aborigines and Caucasians

In an autopsy study on 29 male Aborigines and 57 male Caucasians, macroscopic and microscopic parameters of postnatal cerebellar development were determined and described by mathematic growth functions. For the whole cerebellum and its cortical layers volume measurements revealed delayed maturation for Aborigines compared to Caucasians. Despite the slower development in childhood, significantly smaller values for adult Aborigines compared to Caucasians were observed only for the whole cerebellum and the Purkinje cell sheet. Similarly, postnatal changes in Purkinje cell size showed prolonged growth phases in Aborigines compared to Caucasians. Calculations of absolute cell numbers for individual layers demonstrated later half-value times and slower growth rates for cell numbers in the internal granular and molecular layers consistent with the findings for the corresponding layer volumes. For Caucasians, the growth curve for the absolute cell number in the internal granular layer showed a maximum about 21 months postnatally and subsequently decreased towards adulthood by about 18%. No such overshoot could be demonstrated for Aborigines. In relation to absolute cell numbers in adulthood, this could indicate a smaller number of granule cells migrating from the external to the internal granular layer as well as less pronounced granule cell death in Aborigines compared to Caucasians. The external granular layer of Caucasians increased in volume postnatally to reach a maximum at about 4 months and subsequently decreased until its disappearance at approximately 2 years of age. The number Purkinje cells decreased marginally postnatally in both populations. These results were discussed in relation to secular changes of growth parameters of the cerebellum during the last century and the socioeconomic and health status of Aborigines.