Search

The need for biological markers of Alzheimer disease (AD) is constantly increasing. Proton magnetic resonance spectroscopy (1H-MRS) studies have provided consistent evidence for a reduction of the neuronal marker N-acetylaspartate (NAA) in patients with AD. Within the German Competence Network on Dementia, we conducted a 1H-MRS study in patients with mild dementia and mild cognitive impairment (MCI) at four sites to investigate the multicenter feasibility of 1H-MRS.

Significant 31P NMR signal enhancement through heteronuclear polarisation transfer was obtained in model solutions and in vivo on a 1.5-T whole-body MR scanner equipped with two RF channels. The much higher population differences involved in proton Zeeman energy levels can be transferred to the 31P levels with the refocused INEPT (insensitive nucleus enhancement by polarisation transfer) double-resonance experiment by means of a series of simultaneously applied broadband RF pulses. INEPT achieves a polarisation transfer from 1H to 31P spin states by directly reordering the populations in spin systems with heteronuclear scalar coupling. Thus, only the 31P NMR signal of metabolites with scalar 1H–31P coupling is amplified, while the other metabolite signals in the spectra are suppressed. Compared to Ernst-angle excitation, a repetition-time-dependent signal enhancement ofη=(29±3)% for methylene diphosphonic acid (MDPA) andη=(56±1)% for phosphorylethanolamine (PE) was obtained on model solutions through optimisation of the temporal parameters of the pulse experiment. The results are in good agreement with numerical calculations of the theoretical model for the studied spin systems. With optimised echo times, in-vivo 31P signal enhancement of the same order was obtained in studies of the human brain.Significant 31P NMR signal enhancement through heteronuclear polarisation transfer was obtained in model solutions and in vivo on a 1.5-T whole-body MR scanner equipped with two RF channels. The much higher population differences involved in proton Zeeman energy levels can be transferred to the 31P levels with the refocused INEPT (insensitive nucleus enhancement by polarisation transfer) double-resonance experiment by means of a series of simultaneously applied broadband RF pulses. INEPT achieves a polarisation transfer from 1H to 31P spin states by directly reordering the populations in spin systems with heteronuclear scalar coupling. Thus, only the 31P NMR signal of metabolites with scalar 1H–31P coupling is amplified, while the other metabolite signals in the spectra are suppressed. Compared to Ernst-angle excitation, a repetition-time-dependent signal enhancement ofη=(29±3)% for methylene diphosphonic acid (MDPA) andη=(56±1)% for phosphorylethanolamine (PE) was obtained on model solutions through optimisation of the temporal parameters of the pulse experiment. The results are in good agreement with numerical calculations of the theoretical model for the studied spin systems. With optimised echo times, in-vivo 31P signal enhancement of the same order was obtained in studies of the human brain.

1H MRS imaging was obtained from 10 patients with mesial temporal lobe epilepsy before and after surgery. After surgery, metabolic recovery in the contralateral hippocampus was detected. Preoperatively, reduced N-acetylaspartate (p< 0.04) increased after surgery nonsignificantly to equal control values. Cholines increased after surgery (p< 0.02) and creatine–phosphocreatine showed a trend to higher values. The results suggest that the contralateral hippocampus is affected by repeated seizure activity in the ipsilateral hippocampus, rather than presence of bilateral mesial temporal sclerosis.

The appearance of decreased 2-18Ffluoro-2-deoxy-d-glucose (FDG) uptake in the mesial temporal region in temporal lobe epilepsy may simply reflect loss of gray matter due to hippocampal atrophy. Increased partial volume effects due to atrophic hippocampi may further increase appearance of hypometabolism.

Alveolar rhabdomyosarcoma is an aggressive tumour in adulthood, in which cardiac troponin T seems to be a tumour marker and course parameter. We present the clinical course of a young man suffering from this rare disease and the development of troponin T during therapy. Noninvasive cardiac imaging was used to exclude cardiac involvement, myocardial infarction or inflammation processes.

Teleutospores ofPuccinia punctiformis were used for germination and inoculation experiments. The percentage of germination increased with increasing root extract concentration separately from the spore-suspension present in the same Petri dish.

Abstract: Direct volume rendering is a visualization method that allows display of all information hidden in three-dimensional data sets of, for example, computed tomography or magnetic resonance imaging (MRI). In contrast to commonly used surface rendering methods, these algorithms need no preprocessing but suffer from a high computational complexity. A real-time rendering system, VIRIM (Vitec: Visualization Technology GmbH, Mannheim, Germany), cuts down rendering times of minutes on normal workstations to an interactive rate of 1 second or less. The immediate visual feedback allows interactive steering of the visualization process to achieve insight into the internal three-dimensional structure of objects. Additional information is obtained by using an interactive gray-value segmentation tool that both allows segmentation of the data set according to bone, tissue, and liquor and display of multifunctional data sets (e.g., functional MRI [fMRI] data sets). Thus, real-time direct volume rendering allows segmentation and volume data processing of functional and anatomical MR data sets simultaneously. As this method can be integrated in the clinical routine, it is of great importance for real-time motion artifact detection and the interpretation of fMRI data acquired during cognitive experiments with normal subjects and psychiatric patients. Because of the free programmability of VIRIM, more complex matching procedures are currently being investigated for future implementation.

Vast numbers of spores of the thermophilic actinomycetesExcellospora flexuosa,Thermomonospora alba,T. curvata andT. fusca were collected from the air in fermentation tunnels during the spawning of mushroom compost, i.e. over 109 CFU m-3 of air. Five different genera of fungi, namely,Aspergillus,Aureobasidium,Cladosporium,Penicillium andScytalidium, were found at only 103 CFU m-3 of air.Agaricus bisporus, used for spawning, was absent. Sera of 10 mushroom growers affected by Mushroom Worker's Lung (MWL) were tested by a qualitative dot-ELISA for antibodies against the spores of these micro-organisms. All 10 were positive for one or more of the actinomycetesE. flexuosa,T. alba,T. curvata andT. fusca. No antibodies were found againstStreptomyces thermovulgaris,Thermoactinomyces vulgaris andT. sacchari nor against the fungiAspergillus fumigatus,Penicillium brevicompactum,P. chrysogenum,Scytalidium thermophilum andTrichoderma viride. Sera of 11 of 14 workers engaged in routine spawning of compost in tunnels reacted positively with 1 or more of the actinomycetes. Their10log serum titres increased with the duration of employment to an upper limit of 2.5. The sera of 19 non-exposed individuals were negative. Because high numbers of spores ofE. flexuosa,T. alba,T. curvata andT. fusca were present in the air that was used for successful inhalation provocation of mushroom workers with MWL and because of the elevated serum titres of these workers, we presume these organisms to contribute in the occurrence of MWL.

Flower bud formation was studied in thin-layer tissue expiants of epidermis plus subepidermal cortex from the inflorescence ramifications ofNicotiana tabacumcv. Samsun. With appropriate hormone concentrations of BA and NAA expiants from flowerv and fruitbearing stalks regenerate flower buds only, while those from the internodes of the inflorescence ramifications produce generative as well as vegetative buds. In both types of expiants the number of buds formed depend mainly on the hormone concentrations but, in addition, the age of stalks and internodes from which expiants are taken also affects bud formation. Both ABA and JA inhibit flower bud formation in expiants of flower stalks. JA was shown to particularly inhibit bud initiation.

Evidence is presented suggesting that the sporulation ofS. fructicola probably proceeds by several phases. Light stimulates development of primordia but inhibits conidia formation.

Conclusies Uit bovengenoemde proeven kan het volgende worden geconcludeerd:1.Niet alleen houtaantasters, maar ook sommige andere fungi zijn in staat koperverbindingen in vitro af te breken en deze in een andere vorm weer neer te slaan.2.Dit vermogen om koperverbindingen af te breken en om te zetten is gebonden aan het zuurvormend vermogen van de schimmels.3.Er dient een duidelijk onderscheid gemaakt te worden tussen kopermiddelen als preventief bestrijdingsmiddel, bedoeld tegen de sporekieming, en als curatief bestrijdingsmiddel, bedoeld tegen reeds aanwezig mycelium.4.Geen verband kon worden vastgesteld tussen de graad van zuurvormend vermogen van een schimmel en het vermogen te groeien op voedingsbodems, waaraan koperverbindingen in verschillende concentraties toegevoegd waren.

Pathophysiological models are urgently needed for personalized treatments of mental disorders. However, most potential neural markers for psychopathology are limited by low interpretability, prohibiting reverse inference from brain measures to clinical symptoms and traits. Neural signatures—i.e. multivariate brain-patterns trained to be both sensitive andspecific to a construct of interest—might alleviate this problem, but are rarely applied to mental disorders. We tested whether previously developed neural signatures for negative affect and discrete emotions distinguish between healthy individuals and those with mental disorders characterized by emotion dysregulation, i.e. Borderline Personality Disorder (BPD) and complex Post-traumatic Stress Disorder (cPTSD). In three different fMRI studies, a total sample of 192 women (49 BPD, 62 cPTSD, 81 healthy controls) were shown pictures of scenes with negative or neutral content. Based on pathophysiological models, we hypothesized higher negative and lower positive reactivity of neural emotion signatures in participants with emotion dysregulation. The expression of neural signatures differed strongly between neutral and negative pictures (average Cohen's d = 1.17). Nevertheless, a mega-analysis on individual participant data showed no differences in the reactivity of neural signatures between participants with and without emotion dysregulation. Confidence intervals ruled out even small effect sizes in the hypothesized direction and were further supported by Bayes factors. Overall, these results support the validity of neural signatures for emotional states during fMRI tasks, but raise important questions concerning their link to individual differences in emotion dysregulation.

Croes, A. F., Creemers-Molenaar, T., van den Ende, G., Kemp, A. and Barendse, G. W. M. 1985. Tissue age as an endogenous factor controlling in vitro bud formation on explants from the inflorescence of Nicotiana tabacum L.—J. exp. Bot. 36: 1771–1779. The in vitro formation of generative buds was studied on explants from flower and fruit stalks and from internodes of the floral ramifications of tobacco. A floral gradient was found to exist along the axis of the branch. The gradient concerns the number of flower buds formed in vitro and is present in both types of tissues. The number of flower buds is greater on tissues from the apical than from the basal portion of the branch. The capacity to generate these buds is largely determined by tissue age at the moment of the excision. Consequently, the gradient moves along the axis during the outgrowth of the inflorescence. The alternative possibility that some apex-derived stimulus predetermines the morphogenetic capacity of the tissue prior to excision is excluded by the observation that the gradient remains virtually unaltered if the apex is removed one week before the onset of culturing. Auxin affects the floral gradient Increasing the auxin concentration in internode tissue culture causes a steeper gradient of flower bud generation by almost completely abolishing bud formation on older tissues.

The effect of glucose on flower bud formation was studied in thin-layer tissue cultures of epidermal strips from flower stalks of Nicotiana tabacum L. cv. Samsun. A minimum concentration of 30 mol m−3 glucose in the MS-medium containing 1.0 mmol m−3 of both NAA and BA was necessary for flower bud formation. With 150 mol m−3 glucose a minimum stay of 10 d was required for optimal flower bud formation. Withholding glucose for a limited period at different time intervals after the onset of culture caused a delay in flower bud formation and did not affect previous development on glucose. The results indicated that competence for flower bud initiation is not restricted to the early stage of culture. The process may start at any time later at the appropriate glucose concentration. However, for both optimal initiation and further development of flower buds the presence of a metabolizable sugar is required. Incubation of the tissue on glucose is associated with higher respiration rate.