Biomedical subjects
Publications and source records attributed to S Zschocke.
Utilizing the QCD sum rule approach to the behavior of the omega meson in nuclear matter we derive evidence for in-medium changes of particular four-quark condensates from the recent CB-TAPS experiment for the reaction gamma + A --> A' + omega(--> pi0gamma) with A = Nb and LH2.
Ligusticum chuanxiong Hort., a plant that is frequently used in traditional Chinese medicine, has been studied using HPLC-coupled spectroscopic techniques such as HPLC-UV, HPLC-MS as well as HPLC-NMR. With the aid of these modern spectroscopic techniques, the main constituents, namely senkyunolide A, butylphthalide, neocnidilide and Z-ligustilide, have been characterized and identified. Phthalide dimers, present in smaller amounts, have been identified by HPLC-UV and HPLC-MS analysis and compared with reference compounds. Stereochemical features of some phthalide monomers have been determined by detailed spectroscopic studies for the first time.
A novel diastereomer of ocobullenone. designated as sibyllenone, was isolated from the stem bark of mature Ocotea bullata in the course of a search for anti-inflammatory compounds from this plant. The stereostructure was established by X-ray crystallography and corroborated by NOESY analysis. Ocobullenone, obtained previously, was re-isolated and crystallised successfully for X-ray analysis, thus making possible an accurate spatial comparison of ocobullenone, iso-ocobullenone and the new stereoisomer. Tested pharmacologically for cyclooxygenase-1 and 2, and 5-lipoxygenase inhibition, sibyllenone was the only compound from O. bullata which showed good inhibitory activity towards 5-lipoxygenase.
Ocotea bullata (Lauraceae), one of the top-ten traditional medicinal plants used in KwaZulu-Natal, is close to extinction through high demand and destructive harvesting methods. The stem bark is traditionally used to cure headaches, urinary disorders and stomach problems. Substitution of leaves for bark provides a possible resource management solution for this threatened medicinal plant. One aim of this study was to compare the chemical composition of O. bullata leaves and bark using TLC, HPLC and GC-MS analysis. The characteristic analytical fingerprints of leaf and bark extracts showed great similarities. A second aim was to investigate the pharmacological properties of O. bullata as a remedy against headaches. Leaf and bark extracts were tested in terms of cyclooxygenase-1 and 5-lipoxygenase inhibition. Extracts from the bark exhibited moderate inhibitory activity in both test systems. Extracts from fresh leaves were superior to bark extracts in terms of their in vitro inhibitory activity against cyclooxygenase-1 and 5-lipoxygenase. Volatiles obtained from n-hexane extracts of leaves and bark showed better inhibitory activity towards cyclooxygenase-1 and especially towards 5-lipoxygenase than the original n-hexane extracts. Volatiles were therefore recognized as one of the main active principles in O. bullata with regards to the anti-inflammatory properties of this medicinal plant. This lends support to the traditional usage of O. bullata bark as an inhalant or snuff.
In response to the serious scarcity of Ocotea bullata (Burch.) Baillon (Lauraceae), an important medicinal plant in South Africa, Cryptocarya species (Lauraceae) are frequently used as substitute plants. Our investigation was aimed at a pharmacological comparison of O. bullata and the Cryptocarya species C. latifolia Sonder, C. myrtifolia Stapf., C. transvaalensis Burtt Davy, C. woodii Engl. and C. wyliei Stapf., in terms of in vitro cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2) inhibition, as an indication of O. bullatas' repute as a remedy against headache. Furthermore, we also compared bark and leaf extracts of the species investigated in order to address the problem of destructive ring-barking. The utilization of leaves instead of bark would help in the management of threatened medicinal plants. All Cryptocarya species were superior to O. bullata with regard to bark extracts. C. woodii bark extracts showed outstanding equipotent activity towards COX-1 and COX-2. The activity of extracts of fresh leaves was comparable to the activity of the respective bark extracts. Drying the leaves before extraction resulted in a loss of activity, with the exception of C. wyliei. Extracts of dried C. wyliei leaves exhibited high inhibitory activity, with a COX-2/COX-1 ratio of 5.8.
Population growth, urbanization and the unrestricted collection of medicinal plants from the wild is resulting in an over-exploitation of natural resources in southern Africa. Therefore, the management of traditional medicinal plant resources has become a matter of urgency. In southern Africa the most frequently used medicinal plants are slow-growing forest trees, bulbous and tuberous plants, with bark and underground parts being the parts mainly utilized. A strategy which would satisfy the requirements of sustainable harvesting, yet simultaneously provide for primary health care needs, would be the substitution of bark or underground parts with leaves of the same plant. This paper outlines the concept of plant substitution, using preliminary results of our recent investigations into four of the most important and most threatened South African medicinal plants - Eucomis autumnalis (bulb), Siphonochilus aethiopicus (rhizome), Ocotea bullata (bark), and Warburgia salutaris (bark) - as a demonstration of the kind of research necessary. Extracts of various plant parts were compared chemically using TLC-analysis, and pharmacologically in terms of antibacterial activity and cyclooxygenase-1 inhibition in vitro. The importance of the concept of plant part substitution as a strategy for the conservation of medicinal plants in southern Africa is discussed in terms of the results obtained.
Linoleic acid, osthol, osthenol and two polyacetylenes, falcarindiol and 11(S),16(R)-dihydroxyoctadeca-9Z,17-diene-12,14-diyn-1 -yl acetate were found to be the most active compounds responsible for the inhibitory activity of the dichloromethane extract of the roots of Angelica pubescens f. biserrata on 5-lipoxygenase (5-LO) and cyclooxygenase (COX-1) in vitro. They showed prominent inhibitory effect on 5-LO with IC50 values of 27.9 microM, 36.2 microM, 43.1 microM, 9.4 microM and 24.0 microM, respectively. Linoleic acid, osthenol, falcarindiol and 11(S), 16(R)-dihydroxyoctadeca-9Z,17-diene-12,14-diyn-1-yl acetate exhibited inhibitory activity on COX-1 with IC50 values of 13.3 microM, 64.3 microM, 66.0 microM and 73.3 microM.
The conversion of EEG findings and the evolution of clinical signs was investigated in 7 CJD patients who underwent serial EEG recordings along the course. At the onset of PSWC (mean 8.7 weeks), 5 patients had already progressed to akinetic mutism (characterized by loss of verbal contact and directed responses); and a CJD-typical-movement disorder (myoclonia, exaggerated startle reaction or focal dyskinesia) had started in 5 patients. When akinetic mutism commenced (on average at 7.5 weeks), runs of frontal intermittent non-peaked rhythmical delta activity (FIRDA) were found in all cases. These were later replaced by PSWC in 6 patients (interval 1 to 3 weeks). Occurrence of PSWC was often negatively related to external stimuli (2 of 6 cases), and sedative medication (all patients tested). We conclude that the selection of EEG recording dates to detect PSWC in CJD-candidates should be guided by detailed information about movement disorders and conscious level. Regarding the short survival time after their onset (average 8 weeks), PSWC usually mark the terminal stage of CJD. To detect PSWC, especially, EEG registrations in advanced stages are often necessary. In earlier disease stages, FIRDA-like EEG activities should be regarded as compatible with this diagnosis, and encourage further EEG studies for the demonstration of PSWC in a more advanced stage of CJD.
The n-hexane extract of Qianghuo (underground parts of Notopterygium incisum Ting x H.T. Chang, Umbelliferae) showed inhibitory activity in vitro in 5-lipoxygenase (5-LO) and cyclooxygenase (COS) assays. Two major constituents, phenethyl ferulate and falcarindiol, and one minor compound (-)-bornyl ferulate, were identified as the main active principles. The correlation between the content of active constituents and the inhibitory activity of the extracts was examined with seven commercial drug samples from different sources. It was obvious that the content of phenethyl ferulate was mainly responsible for the COX inhibitory activity of the extracts and falcarindiol for 5-LO inhibitory activity. Since the main active constituents phenethyl ferulate and falcarindiol can easily be quantified by HPLC, this is a suitable method for standardization and characterization of the drug.
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It will be reported about 142 EEG spectral analytic mappings in 100 patients with focal EEG findings which were recorded already in routine EEG examinations. Drawings of the visually analysed paper recordings have been compared with the maps. We found in about 30 per cent a true gain of information. It is based on a more precise demarcation of focal findings or a better display of points of most severe dysfunction within extended disturbances. Beyond that the pictorial presentation of topographic features is a general advantage of EEG mapping. On the other side there are limits and disadvantages of topographic EEG analysis. With special reference to the analysis of circumscribed dysfunctions they will be demonstrated. Problems are related to the type of reference, to the choice of analysis time, or to "spatial aliasing effects" which are introduced by the interpolation procedure of mapping analysis. Beside the neuroradiological imaging methods the EEG mapping maintains special significance because it displays the functional aspect of cerebral processes.
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Clinical symptoms and course in a 28 year old woman who suffered from rabies are reported. Neurophysiological and neuropathological findings in this patient, who died 21 days after developing initial symptoms, are presented in more detail. This disease appears to be rare in Central Europe. It can be treated effectively only by means of early detection and a special vaccination programme. Late recognition of lyssa specific symptoms in non-vaccinated patients is invariably associated with a fatal outcome. A review of current knowledge concerning rabies research is presented.
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EEG long-term monitorings were carried out in 149 patients using a portable 4-channel miniature recorder system. In most cases EEG was recorded for 48 hours. In addition to preceding routine EEG controls, long-term EEG monitoring disclosed epileptic phenomena in 32.7% of patients suspected for epileptic seizures from their history. This gain of information was based mainly on the detection of abnormal potentials or epileptic seizures appearing during sleep. Using EEG long-term recording numerous EEG routine controls could be replaced which otherwise are often necessary for ensuring the diagnosis of epilepsy. If the patient's history, however, gives only poor reason to believe epileptic seizures, positive findings in EEG long-term monitorings are unlikely. Consequently, careful evaluation of the patient's history is crucial for the indication of this laborious examination. As the limited number of recorder channels may cause false negative results, normal findings should be utilized with caution. Only the sum of all clinical and neurophysiological data should be used for exclusion of suspected epilepsy. The second, even more important application of EEG long-term recordings is the special examination of patients with known epilepsy, such as studies of the circadian profiles of epileptic excitability, documentation of seizure frequency, and electrographic analysis of the course of seizure. Therapy control of epileptic patients can be improved by such informations. In view of the large amount of data which results from long-term recordings, computer assisted methods supporting the visual analysis are necessary. In this regard the continuous spectral analysis of the EEG long-term recordings proved to be highly useful.
It is suggested that disturbances of excitation velocity in optic nerve disease go along with a temporal heterogenity of impulse conduction which subsequently may be responsible for an increased variability of latencies of cortical visual evoked potentials. Since the latencies of each single evoked response, being superimposed by EEG-background activity, cannot be measured, we developed a computer-assisted statistical technique in an attempt to quantify this variability. Random samples (n = 30) were taken from the whole of stimulus-correlated EEG-segments recorded during a clinical routine examination (n = 200) and averaged to give a number (n = 30) of randomly sampled VEP's. The results of the statistical analysis, by calculating the variability of the latency values of these samples, can be taken as an approximation of the real variability of latency of single evoked potentials. It could be demonstrated that the variability of latency of the first clearly defined positive component P2 of the pattern-induced VEP is increased even in cases of clinically suspected retrobulbar neuritis or disseminated encephalomyelitis, where the summed VER-latency turned out to be within normal limits. Based upon these results, the statistical analysis proposed here has proven to be of differential diagnostic significance as an additional parameter - besides the ordinary measurement of latency - especially in borderline cases.
This study demonstrates the possibilities of continuous frequency analysis supporting the evaluation of long lasting EEG recordings which present problems in analysing large amount of data. Avoiding some disadvantages of the usual presentation of power spectra by compressed spectral array compression of the spectral data will be obtained in a more suitable way by sequential plots of the data on the abscissa as time axis. The spectra will be separated in only a few number of frequency bands. A special conversion procedure (linear multiplication of the data within each frequency band by logarithmic calculated factors) provides for the essential enhancement of low spectral power in the upper EEG frequency domain preserving the full dynamic of spectral variations. The efficiency of this spectral trend analysis is shown by two examples: (1) In the study of the variations of cerebral excitability in a patient with epileptic seizures depending on the waking-sleeping-cycle (Fig. 3), and (2) in the documentation of the EEG dynamics in the course of intensive care monitoring. Fig. 5 shows the development of a cerebral autorhythmicity representing reintegration of cerebral function in a patient with severe head injury.
In the evaluation of chiasmal syndromes the efficiency of VER analysis could be enhanced by separate stimulation of the temporal and nasal half of the visual field. The report is based on data of 27 patients with compressive chiasmal lesions. VER findings have been correlated with the visual fields meticulously plotted with a Tuebingen perimeter and/or an Octopus computer perimeter. Alterations in both parameters have been graded in three groups. The degree of alteration correlated fairly well for both test procedures. Not only was a reduction of VER amplitude observed for the affected hemifield, but a latency delay as well. A discrete damage in the nasal hemifield may be detected even earlier by means of VER half field analysis than by conventional subjective perimetry.