Betulin aus der Birkenrinde für die Haut

Der pflanzliche Wirkstoff Triterpentrockenextrakt (Betulin) aus der Birkenrinde wurde durch 2 weltweit patentierte Erfindungen, die „Betulin-Emulsion“ und das „Betulin-Oleogel“, für die Anwendung an der Haut erschlossen. Die tensidfreie Betulin-Emulsion führte zur Entwicklung der Kosmetikserie Imlan. Systematische kosmetische Studien zeigten eine Schutzwirkung von Imlan gegen den irritierenden Effekt von starken Tensiden, die als Emulgatoren oder Schaumbildner Verwendung fanden und finden, wie z. B. Natriumdodecylsulfat.

Das wasserfreie Betulin-Oleogel wurde zum Arzneimittel Episalvan mit dem klinischen Nachweis der beschleunigten Wundheilung entwickelt. Im Januar 2016 erfolgte die zentrale europäische Zulassung für das Arzneimittel.

Halogenokomplexe von Osmium(III) mit Pyridin, Pyrazin, Pyrimidin und einigen Methylhomologen

The preparation of mer-[OsX3B3], X = Cl, Br, I; B = pyridine, 3-resp. 4-picoline, pyrimidine, pyrazine, methylpyrazine, and the chromatographic isolation of four basemixed stereoisomers mer-[OsX3(py)n(mepyz)3-n], n= 1, 2, as solid crystalline products is described. Mass spectra and ligand exchange reactions confirm the structure of these complexes. The UV and IR spectra are discussed.

A novel triterpene extract from mistletoe induces rapid apoptosis in murine B16.F10 melanoma cells

The European mistletoe Viscum album L. is a plant used for remedies in cancer treatment. The benefit of commonly used aqueous extracts is controversial but the plant contains water insoluble triterpene acids providing interesting anticancer properties. Triterpene extracts (TE) from plants and single triterpenoids such as oleanolic acid (OA) or betulinic acid (BA) are known for their cytotoxic effects on cancer cell lines in vitro. We report here cytotoxic effects of a novel OA-rich triterpene extract from mistletoe (V. album L., Santalaceae) solubilized by 2-hydroxypropyl-β-cyclodextrin (2-HP-β-CD) on B16.F10 mouse melanoma cells. The 2-HP-β-CD solubilized triterpene extract (STE) was highly cytotoxic by causing DNA fragmentation, followed by loss of membrane integrity and intracellular adenosine-5'-triphosphate (ATP). Blocking the caspase machinery by inhibitors aborted DNA fragmentation and delayed the cytotoxic effects but did not prevent cell death. The solubilization by 2-HP-β-CD allows a solvent-free application of triterpene extracts in the in vitro setting. These findings suggest the use of STE from mistletoe as a solvent-free anticancer drug for preclinical animal experiments and clinical trials.

Olea europaea leaf extract exerts L-type Ca(2+) channel antagonistic effects

ETHNOPHARMACOLOGICAL RELEVANCE

In Southern Europe Olea europaea leafs are known as a folk remedy for hypertension. Cardiovascular diseases are still the leading causes of morbidity and mortality in industrialized countries with hypertension being one of the main risk factors.

AIM OF THE STUDY

We investigated effects of a commercial Olea europaea leaf extract (OLE) on isolated hearts and cultured cardiomyocytes.

MATERIALS AND METHODS

Isolated rabbit hearts were perfused according to the Langendorff technique and connected to a 256-channel epicardial mapping system. Voltage clamp experiments were performed in cultured neonatal rat cardiomyocytes using a perforated-patch technique.

RESULTS

OLE caused a concentration-depended decrease in systolic left ventricular pressure and heart rate as well as an increase in relative coronary flow and a slight, but not significant prolongation of PQ-time. There were no significant changes between the groups in the activation-recovery interval and its dispersion, total activation time, peak-to-peak amplitude, percentage of identical breakthrough-points and similar vectors of local activation. Voltage clamp experiments in cultured neonatal rat cardiomyocytes showed a significant decrease in maximum I(Ca,L) by OLE which was reversible upon wash-out.

CONCLUSIONS

OLE suppresses the L-type calcium channel directly and reversibly. Our findings might help to understand the traditional use of OLE in the treatment of cardiovascular disease.

A new role for extracellular Ca2+ in gap-junction remodeling: studies in humans and rats

We wanted to elucidate whether extracellular calcium may regulate the expression of the cardiac gap-junction proteins connexin 40 and connexin43. In the free wall of the left atria of 126 cardiac surgery patients with either sinus rhythm (SR) or chronic atrial fibrillation (AF), we determined the expression of the cardiac gap-junction proteins Cx43 and Cx40 by Western blot and immunohistology. For deeper investigation, we incubated cultured neonatal rat cardiomyocytes at 2 or 4 mM Ca(++) for 24 h and determined intercellular coupling, Cx40, Cx43 protein and mRNA expression, protein trafficking and sensitivity to verapamil (10-100 nM), cyclosporin A (1 microM),and BMS605401 (100 nM), a specific inhibitor of Ca(2+)-sensing receptor (CaSR). We found in patients that both Cx are up-regulated in AF in the left atrium (by 100-200%). Interestingly, Cx40 was mainly up-regulated, if total serum calcium was >or=2.2 mM, while Cx43 was independent from extracellular [Ca(++)]. In cultured cells, 4 mM Ca(++)-exposure lead to up-regulation of Cx40, but not Cx43. We found enhanced Cx40 in the plasma membrane and reduced Cx40 in the Golgi apparatus. The membrane Cx40 up-regulation resulted in enhanced gap-junction intercellular coupling with a shift in the Boltzmann fit of voltage-dependent inactivation indicating a higher contribution of Cx40 as revealed by dual whole cell voltage clamp experiments. BMS605401 could prevent all Ca(2+)-induced changes. Moreover, cyclosporin A completely abolished the Ca(2+)-induced changes, while verapamil was ineffective. We conclude that extracellular calcium (24 h exposure) seems to up-regulate Cx40 but not Cx43.

Induction of antibodies to viscotoxins A1, A2, A3, and B in tumour patients during therapy with an aqueous mistletoe extract

Mistletoe extracts exert immunomodulatory properties on immunocompetent cells of the innate as well as the specific immune system. These effects have been mainly ascribed to mistletoe lectin 1 (ML-1) present in most of the extracts. However, it became evident that also other components of these extracts may induce immunological reactions, and especially viscotoxins (VT) may be of relevance. Aim of the study was, therefore, to evaluate whether VT like ML-1 could activate B-cells and lead to the production of VT-specific antibodies. Sera from 26 patients with different tumours who were treated with the mistletoe extract ABNOBAviscum Mali (AM) 4 for at least 18 weeks were analysed before therapy and after 3, 6, 9, 12, and 18 weeks. Sera were tested by ELISA against the four viscotoxins A1, A2, A3, B, as well as against ML-1. Within the observation period twenty-four (92%) of the 26 patients developed antibodies to at least one of the four VT and 25 (96%) to ML-1. In most instances, anti-VT antibodies appeared after 6-9 weeks of treatment. The antibodies were predominantly of the IgG type belonging preferentially to the IgG1 and IgG3 subclass. IgE antibodies were found only to VT-B and to ML-1. There was no relation between the development of antibodies to VT and ML-1, and also cross-reactivity could be excluded with high probability. These data indicate that not only ML-1 but also VT induce immunological responses in patients treated with mistletoe extracts. Whether there is any relationship to the postulated anti-tumour effect of mistletoe extracts has, however, still to be evaluated.

Polysaccharides from fresh Viscum album L. berry extract and their interaction with Viscum album agglutinin I

A special microfiltrated colloidal preparation from fresh Viscum album L. berries was investigated concerning the occurrence and structural features of polymeric carbohydrates. A crude polysaccharide fraction was isolated from lectin-, tannin- and protein-depleted microfiltrates. Further fractionation by exchange chromatography revealed a neutral fraction (average molecular weight 30 kDa) and three acidic fractions (average molecular weights 1300 kDa). Structural analysis of the respective polysaccharide fractions by quantitative and qualitative determination of the sugar composition and linkage analysis indicated that all acidic fractions contained an acidic arabinogalactan with a rhamnose-galactoronic acid backbone and highly branched arabinose-galactose side chains attached by the rhamnose residues to the backbone. The neutral fraction consisted of a neutral arabinogalactan beside minor amounts (about 10%) of a low substituted xyloglucan. Further studies on interaction between the 1340 kDa acidic rhamno-arabinogalactans II and III and mistletoe lectin Viscum album agglutinin I (VAA I) revealed binding capacities between these compounds, while the neutral polymers interacted significantly less with VAA I. Only partial binding of VAA I was observed by incubation of the lectin with polysaccharide II. Similar interactions of polysaccharide fraction III with VAA I was measured in a BIACRORE biosensore system. Using the hemagglutination test, increased agglutination of erythrocytes was observed when mistletoes lectin I and the respective polysaccharide fractions were present together in the assay. All these data indicate clearly strong interaction between VAA I and Viscum polysaccharides.

[Value of vasoactive drugs in conservative therapy of peripheral arterial occlusive disease]

Based on controlled clinical trials, vasoactive drugs (pentoxyfylline, naftidrofuryl, buflomedil) and prostanoids (alprostadil, iloprost) are used in symptomatic peripheral arterial occlusive disease: In stage II, vasoactive drugs are prescribed in order to improve leg hyperemia in response to muscular work; in complicated stage II (e.g., non-healing traumatic skin lesions), and in stages III/IV, prostanoids are given in order to increase forefoot skin blood flow. These drugs should only be applied if neither angioplasty nor vascular surgery are recommendable, possible, or successful after complete angiological diagnostic. It should be considered that these substances have a rather limited clinical efficacy in both stage II and stages III/IV and therefore attempts should be made to select patients with a reasonable chance to benefit. These drugs are also not suitable for primary or secondary prophylaxis against the progression of vascular lesions.

Photohaemolytic activity of chlorophyll degradation products in a mistletoe extract

An aqueous mistletoe extract containing liposome-like vesicles from chloroplast membranes develops a photohaemolytic activity, which is a function of the temperature. This is correlated with the degradation of chlorophyll. The photolytic activity of the chlorophyllides initially produced in the process was detected by haemolysis. The quantification of the chlorophyllides was performed using HPLC. On being exposed to light, the isolated green vesicle fraction bleaches out extremely rapidly in the presence of traces of oxygen. In this process, the photolytic activity also disappears. In crude extracts, this only occurs to a small extent.

Oligoclonal in vitro response of CD4 T cells to vesicles of mistletoe extracts in mistletoe-treated cancer patients

Mistletoe (Viscum album) extracts are widely used in adjuvant cancer therapy. We have investigated the in vitro responsiveness of T cells from mistletoe-treated cancer patients and untreated healthy donors to various preparations of mistletoe extracts. Proliferation of peripheral blood mononuclear cells from treated but not from untreated patients was observed in response to therapeutically used mistletoe extracts prepared from apple (mali) or pine (pini) host trees. The strongest proliferation was induced by a vesicle preparation of mali extract. Activation was strongly inhibited by interleukin-10. Using a newly developed flow-cytometry assay, we determined that cell growth was restricted to CD4 T cells. Analysis with a panel of monoclonal antibodies against the variable region of the T cell receptor beta chain (V beta) revealed an oligoclonal pattern of CD4 T cell activation. These results indicate that therapeutic administration of mistletoe extracts sensitizes a restricted set of CD4 T lymphocytes in mistletoe-treated patients.

Stimulation of the specific immune system by mistletoe extracts

We have investigated the in vitro responsiveness of T cells from mistletoe-treated cancer patients and untreated donors to various preparations of mistletoe extracts. Proliferation of peripheral blood mononuclear cells from treated but not from untreated patients was observed in response to therapeutically used mistletoe extracts prepared from apple (mali) or pine (pini) host trees. The strongest proliferation was induced by vesicle preparation of mali extract. Using a newly developed flow cytometry assay (standard cell dilution assay), we determined that cell growth was restricted to CD4+ T cells. Analysis with a panel of monoclonal antibodies against variable regions of the T cell receptor beta chain (V beta) revealed an oligoclonal pattern of CD4+ T cell activation. These results indicate that therapeutic administration of mistletoe extracts sensitized a restricted set of CD4+ T lymphocytes in mistletoe-treated patients. Lymphocytes from untreated donors are only stimulated with heat-treated mistletoe extracts. The responding T cells are gamma delta T cells and express variable T cell receptor elements V gamma 9 and V delta 2. The gamma delta-stimulating activity of heat-treated mistletoe extracts is sensitive to treatment with alkaline phosphatase but not with proteinase K, indicating that the ligands are non-proteinaceous phosphate-containing compounds.

Activation of human gamma delta T-cells by heat-treated mistletoe plant extracts

Various microorganisms including mycobacteria, other bacteria and parasites such as Plasmodium falciparum are known to activate human gamma delta T-cells in vitro. In this study, we demonstrate that heat-treated (but not untreated) mistletoe extracts similarly stimulate human gamma delta T-cells during in vitro culture. The responding T-cells express the variable T-cell receptor elements V gamma 9 and V delta 2. The gamma delta-stimulating activity of heat-treated mistletoe extracts is sensitive to treatment with alkaline phosphatase but not with proteinase K, indicating that the ligands are non-proteinaceous phosphate-containing compounds. Mistletoe-derived ligands share these features with the previously defined mycobacteria-derived ligands for gamma delta T-cells.

Attractors and quasi-attractors in the cutaneous perfusion in human subjects and patients: "chaotic" or adaptive behaviour?

The causes of the aperiodic fluctuations in the perfusion of the skin (volar hand, measured by the Laser-Doppler (LD) technique) of healthy human subjects were studied were studied by simultaneous recording of the fluctuations of local blood content (reflectiophotoplethysmography (rPPG)) and those in the skin of the glabella. Various thermoregulatory situations were provoked by exposing 12 subjects to 18, 21, 24 and 27 degrees C ambient temperature; in addition, the hands were placed at, below and above heart level. In mentally relaxed subjects (evidenced by a stable approx. 0.015-Hz rhythm in the glabellar rPPG signal), there was perfect temporal correlation between aperiodic LDA and rPPG signal under all thermoregulatory conditions. Clearly identifiable episodes of retardation associated with skin bleaching, asymmetrical shape of LDA and rPPG signals were taken as indicators of episodic sympathetic skin constrictor (SSC) activity. In synergetic terms, the modulated SSC activity operates as transient "quasi-attractor'. A notable exception occurred: when the hand was placed below heart at 27 degrees C ambient temperature, a sinusoidal periodic fluctuation (approx. 0.03 Hz) in the LDA evolved. These were not seen the rPPG signal, i.e., coherence between LDA and rPPG dynamics was lost). Lack of coherency between LDA-rPPG, also observed in patients with autonomic neuropathy and decompensated forms of peripheral arterial disease, suggesting predominance of spontaneously oscillating myogenic vasomotion after removal of temporally variable SSC drive. Stable vasomotion is regarded as a synergetically stereotyped reaction rather than as "well-ordered' stable attractor mode of operation.

Topographical evaluation of skin perfusion patterns in peripheral arterial occlusive disease by means of computer-assisted fluorescein perfusography

OBJECTIVE

To evaluate the clinical impact of computer-assisted fluorescein perfusography in peripheral arterial occlusive disease (PAOD).

DESIGN

Foot and calf skin perfusion was visualised by intravenous fluorescein injection. Fluorescein influx was recorded photographically and converted into functional images of fluorescein appearance times (AT) by means of digital film processing.

SETTING

Vascular Laboratory of Clinic for Vascular Disease.

MATERIALS

249 patients with PAOD. Among 481 limbs studied, 83 legs presented with patent arteries, 70 with asymptomatic obstructions (Stage I), 170 with claudication (Stage II) and 158 with rest pain and skin lesions (Stage III/IV).

CHIEF OUTCOME MEASURES

Forefoot and calf mean ATs and standard deviations (SD) served as arbitrary measures of regional skin perfusion rates and their homogeneity, respectively.

MAIN RESULTS

In the control legs, a homogeneous and fast fluorescence appearance was observed (medians at the foot: AT33.4 s, SD 3.6). In stage II disease, AT (39.9 s, SD 5.6) were slightly impaired as compared to limbs with patent arteries or stage I disease (p < 0.01). Ninety-seven out of the 158 legs in stage III/IV could be managed by conservative therapy. According to fluorescein-perfusography, they did not differ from stage II disease (AT 38.8 s, SD 6.1). Sixty-one limbs were clinically affected by critical ischaemia. They exhibited a markedly delayed and heterogenous fluorescein influx at the foot (AT 77.3 s, SD 26.5, p < 0.01 vs all other groups). Non-fluorescent areas occurred in 53% compared to only 1% of limbs with and without critical ischaemia, respectively. Retrospectively, predictive values of fluorescein perfusography in identifying a critical limb ischaemia (accuracy 93%) were superior to the ankle systolic arterial pressure determination (accuracy 80%).

CONCLUSIONS

Fluorescein perfusography seems to be of diagnostic and prognostic use in PAOD in stage III/IV where inflammatory and ischaemic patterns of dye appearance can be distinguished.

Fractionated total body irradiation and high-dose VP-16 with purged autologous bone marrow rescue for children with high risk relapsed acute lymphoblastic leukemia

Twenty-two children with ALL in high risk second (n = 13), third or subsequent complete remission (n = 9) were treated with high-dose VP-16 60 mg/kg and fractionated total body irradiation (fTBI) 12 Gy, 2 x 2 Gy daily followed by autologous BM rescue. Prior to transplantation all patients had been treated according to intensive German BFM front-line or BFM relapse protocols. In all cases the marrow was purged using monoclonal antibodies attached to magnetic microspheres. All patients engrafted. There was no severe toxicity related to the pre-transplant high-dose chemoradiotherapy. Two patients died in the early course of transplantation from infections (Legionella and Aspergillus). Sixteen patients relapsed within 259 days (median 109 days); 13 died from leukemia. Four patients are alive in CR at a median of 1328 days with a Karnofsky score of 100%. The Kaplan-Meier estimation shows a probability of event-free survival (EFS) of 18% and a probability of relapse of 80%. Considering the otherwise poor prognosis of these children the results are acceptable although the high relapse rate is still disappointing. We conclude that high-dose VP-16 and fTBI combined with ABMT is a curative treatment for some children and should therefore be considered for those who lack an HLA-identical sibling donor. In future better therapy concepts are needed either in pre-transplant conditioning regimens or in post-transplant treatment schedules.

In vitro effects of mistletoe extracts and mistletoe lectins. Cytotoxicity towards tumor cells due to the induction of programmed cell death (apoptosis)

The in vitro effects of therapeutically administered mistletoe extracts (ABNOBAviscum) and pure mistletoe lectins (mainly mistletoe lectin I) on a variety of human and murine tumor cell lines have been investigated. Mistletoe extracts and purified mistletoe lectins inhibited in vitro the growth of all tumor cell lines tested including B cell hybridomas, P815, EL-4, Ke37, MOLT-4 and U937. The mechanism of growth arrest was shown to be due to the induction of programmed cell death (apoptosis). Thus, fragmentation of genomic DNA into oligonucleosomal bands of approximately 200 base pairs in length was observed within 20 h when tumor cells were incubated with mistletoe extracts or lectins. These data point to a rational basis for the direct cytotoxic effects of mistletoe extracts and lectins apart from the postulated immunostimulatory properties of these agents.

A comparative analysis of transcutaneous oximetry (tcPO2) during oxygen inhalation and leg dependency in severe peripheral arterial occlusive disease

Transcutaneous oximetry (tcPO2) performed during either oxygen inhalation or leg dependency was intra-individually compared in 64 patients suffering from a peripheral arterial occlusive disease, with and without critical limb ischemia. Among the 81 extremities investigated, 29 had a moderate peripheral arterial occlusive disease (6 in stage I, 23 in stage II) and 52 were initially affected by rest pain or ulceration (stage III/IV). Thirty-seven legs out of the latter improved under conservative treatment. In the remaining 15 limbs, vascular surgery or an amputation became necessary. The tcPO2 was measured at the forefoot with the patient in supine and sitting positions while breathing room air and in the supine position while inhaling 100% oxygen. In limbs with a tcPO2 below 15 mm Hg of patients in the supine position breathing room air, leg dependency generally provoked larger tcPO2 increases than oxygen inhalation. This difference between oxygen inhalation while supine and room air breathing leg dependency tcPO2 values exhibited an approximately linear correlation with the resting tcPO2. Responses of tcPO2 to leg dependency and oxygen inhalation seemed to reflect different mechanisms, that is, microvascular flow redistribution and supine perfusion reserve, respectively. The best discrimination of critical limb ischemia was observed for the tcPO2 of patients breathing room air while in the supine position, which was not surpassed by either the oxygen inhalation or the leg dependency test. Satisfactory results were achieved by combining limits for, first, supine (10 mm Hg) and sitting (45 mm Hg) tcPO2, as well as, second, ankle arterial pressure (60 mm Hg) and supine tcPO2 (10 mm Hg).

Spontaneous oscillations of laser Doppler skin blood flux in peripheral arterial occlusive disease

In the present study, local temporal fluctuations of skin perfusion were non-invasively measured at the forefoot and calf in 374 limbs of 226 patients with peripheral arterial occlusive disease (PAOD) by means of Laser-Doppler-Flowmetry (LDF). Within the scope of a purely descriptive evaluation, each recording was classified according to four previously defined LDF oscillation types named 'aperiodical', 'sinoidal', 'missing waves', and 'small waves'. The prevalences of these curve patterns distinctly varied with both the macrohemodynamic compensation and clinical severity of PAOD. While type 'aperiodical' predominated in case of a normal or only slightly affected circulation, type 'sinoidal' accumulated in legs with marginal collateralization. In contrast, 'missing waves' and 'small waves' mainly occurred in feet affected by severe PAOD. Which pathophysiological mechanisms are responsible for the different LDF oscillation types still remains to be clarified. Retrospectively, in case of a confirmed PAOD, the diagnosis of critical limb ischemia could not be established and wound healing could not be predicted by means of LDF pattern analysis.

Validation of Doppler measurement of pressure gradients across peripheral model arterial stenosis

Hemodynamic assessment of aortoiliac occlusive disease is necessary for successful arterial reconstruction of the legs. Various methods have been proposed, and the "pull through" intraarterial pressure measurement method is accepted as the best standard. The pressure readings, however, seemed to depend on the intraluminal position of the catheter. To explain these observations and make a comparison between the Doppler method and the pull through method, we have studied centerline velocity changes at the stenosis throat by Doppler ultrasonography, and axial and lateral pressure gradients by use of pressure transducers mounted 10 mm and 40 mm downstream of short (4 mm) axisymmetric sharp-edged model stenoses having cross-sectional reduced areas of 64%, 84%, 91%, and 96%. Axial manometric pressures measured 10 mm beyond the throat of 84% stenosis were more than twice as high as the lateral pressures. No significant difference was observed between axial and lateral pressures measured 40 mm downstream from the throat. This pressure distribution has important clinical relevance. Mean and peak pressure gradients for both the Doppler method and manometric measurements were compared. Measurements with Doppler method and manometric measurements indicated that mean pressure gradients (r = 0.98; SEE = +/- 2.4 mm Hg) correlate better than peak pressure gradients (r = 0.90; SEE = +/- 16.5 mm Hg). Doppler gradients were higher than manometer gradients. Overestimation was 13% for mean pressure gradients and ranged from 10% to 150% for peak pressure gradients. Explanation for the difference between mean Doppler and catheter gradient may be the pressure recovery occurring in the relaminarized poststenotic regions.

Redistribution of skin blood flow during leg dependency in peripheral arterial occlusive disease

A disturbed autoregulation of cutaneous blood flow in legs with peripheral arterial occlusive disease (PAOD) has previously been demonstrated for circumscribed skin areas. In the present study, posturally-induced changes of skin perfusion distribution along ischaemic limbs were investigated topographically in 35 PAOD patients by means of fluorescein perfusography. Among the 68 legs studied, 7 had patent arteries and 61 could be assigned to FONTAINE stages I to IV. Limbs with peripheral skin lesions (stage IV) were further differentiated according to either healing (stage IV+) or non-healing (stage IV-) on conservative treatment. Sitting-up always led to prolonged calf as well as foot fluorescein appearance times (AT) except for legs in stage III or IV- disease. In the latter two groups, decreased sitting as compared to supine AT foot-to-calf ratios indicated a relative shift of dye delivery from proximal towards distal skin regions during posture. In contrast, this measure of blood flow redistribution did not change in the other groups. The redirection of fluorescein influx was significantly correlated with the systolic arterial pressure ankle-to-arm ratios. In conclusion, besides small perfusion pressure increases or passive microvessel distension, a shift of the peripheral resistance ratios may contribute to the improved blood supply of ischaemic skin regions during leg dependency. An arteriolar vasoparalysis does not regularly exist in limbs with skin lesions not primarily originating from ischaemia (stage IV+).

Influence of clinical findings, positional manoeuvres, and systolic ankle arterial pressure on transcutaneous oxygen tension in peripheral arterial occlusive disease

The mutual effects of systolic ankle arterial pressures, positional manoeuvres, and calf artery occlusions on transcutaneous oxygen partial pressures (tcpO2) were studied in 388 legs of 258 patients with peripheral arterial occlusive disease (PAOD). The tcpO2-vs-perfusion pressure relationship could be satisfactorily fitted by a non-linear regression model deduced from the tcpO2 theory. Flow-insensitive ranges of tcpO2-vs-flow hyperbolas were reduced by both leg lowering and moving the electrode towards proximal measuring sites. Lower tcpO2 values were found in case of occluded compared to patent calf arteries at ankle arterial pressure indices below 0.4. The tcpO2 positional variability increased with worsening hemodynamic compensation and was most pronounced in critical limb ischaemia (ischaemic rest pain, non-healing ulcerations). According to a retrospective analysis, a critical ischaemia could be assumed if supine and sitting tcpO2-values exceed neither 10 nor 45 mmHg, respectively.

Skin perfusion patterns (fluorescein perfusography) during reactive hyperaemia in peripheral arterial occlusive disease

From the pathophysiological point of view the regional distribution of blood flow is of special importance in ischaemic tissues. Within this study foot sole skin perfusion was investigated by means of fluorescein perfusography at rest and during reactive hyperaemia in patients with peripheral arterial occlusive disease confined to one limb (Fontaine stage II). Ambient temperatures were maintained around 21 degrees C. Mean fluorescein appearance times on the one side and their standard deviations (SD) and coefficients of variation (CV) on the other side were taken as measures of overall blood supply and homogeneity of flow, respectively. At rest no differences in these parameters could be detected between diseased legs and controls. After a 3-min supra-systolic circulatory arrest at the thigh, a significant reduction of fluorescein appearance times was observed for both groups but was statistically more pronounced in the controls. Furthermore, during reactive hyperaemia standard deviations as well as coefficients of variation decreased significantly only in normal limbs whereas they either remained constant (SD) or even increased (CV) in those with arterial obstructions. All effects associated with reactive hyperaemia showed statistically significant correlations with systolic ankle pressure indices. From these results it is concluded that haemodynamically effective arterial obstructions are followed by not only a restriction of overall hyperaemic blood supply but also a failure to homogenize microcirculatory perfusion in the case of increased flow requirements.

[Experiences with intraoperative radiotherapy in gastric carcinoma (Berlin method)]

The aim of our pilot study is to determine whether intraoperative radiotherapy in gastric cancer cannot only prevent a local relapse but also improve the survival rate. Since November 1987, 26 patients with resectable gastric cancer were irradiated intraoperatively with the linear accelerator using fast electrons (single dose: 12 to 16 Gy). Percutaneous radiotherapy was performed postoperatively with 24 to 38 Gy (4 x 2 Gy per week). For intraoperative and percutaneous radiotherapy the target absorbed dose was selected in a way that their combined effect on the tumor was approximately equivalent to that of a total dose of 60 Gy in the usual fractionating. Up to now, the median survival time for stage III patients (UICC 1987) has been twelve months. In five patients who died of a relapse or of peritoneal carcinosis, histologic evaluation revealed in every case a diffuse tumor type according to Lauren-classification. All relapses occurred within the first eight months. The two-year survival rate according to Kaplan-Meier is 67% for stage III. Advanced resectable gastric cancer of the intestinal tumor type seems to profit from adjuvant intraoperative radiotherapy. The results warrant further research within the framework of a prospective randomized multicenter study.

A microcomputer system for evaluation of laser Doppler blood flux measurements

Results of local skin perfusion measurements performed by laser-Doppler-fluxmetry (LDF) are generally expressed in terms of relative mean values of time constants of signal responses to various procedures. In addition, information is obtained from the frequency and amplitude of temporal signal variations. In this report, a microcomputer system designed for recording, storage, artifact elimination, evaluation, and documentation of LDF measurements will be described. This system consists of a desk-top computer with additional hardware necessary for digital data acquisition and acceleration of mathematical operations. A three-phase model defined by a control, a transient, and an effect interval was programmed in order to standardize calculations within the time domain. For spectral analysis of periodical signal fluctuations, an algorithm was implemented based on a Fast-Fourier-Transformation (FFT) in combination with an optional averaging of several spectra within the frequency domain. Clinical measurements performed on patients with peripheral arterial occlusive disease (PAOD) and healthy volunteers illustrate the features of the system.

Morphological changes in cultures of hippocampus following prenatal irradiation in the rat

The effect of prenatal irradiation was studied in organotypic cultures of hippocampus, prepared from newborn rats that had been exposed to whole-body irradiation of 1 Gy from a 60Co-source at day 13 of pregnancy. Light and electron microscopic observations showed remarkable damage to neuronal mitochondria accompanied by extensive swelling, vacuolation of the Golgi complex, and formation of multilamellar bodies and vesicles of the lysosomal type. In contrast to neuronal alterations, no delay in synaptogenesis or onset of myelination was observed based upon the absence of significant morphological changes in synapses and myelin sheaths. Using this tissue culture model it could be confirmed that prenatal exposure to irradiation, even at low doses, induces specific morphological changes in the brain.

[Fractionated afterloading irradiation as a new procedure for treating inoperable brain tumors]

A method is shown for fractionated afterloading therapy of inoperable cerebral tumors. A 3 mm thick, tube-form applicator of noble metal which is closed at the front side is implanted into the tumor by a stereotaxic technique and firmly screwed together with the osseous calotte. It remains there up to two weeks, giving full mobility to the patient. The afterloading therapy with a moving iridium source is performed one or two times per day with individual doses of 2 Gray. Thus, the chronological and--to a certain extent--also the spatial dose distribution is variable when applying this method.